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Several NiO/TiO2 composites fabricated by the impregnation method were employed as photocatalysts for the photoreduction of gaseous CO2 in this study. The characterizations of fabricated photocatalysts were observed by XRD, FE-SEM, EDS, N2 adsorption-desorption, and UV–vis spectroscopy. The distribution of Ni, Ti, and O atoms on the surface of these photocatalysts was demonstrated to be uniform, and the BET surface areas were varied slightly with the increase of NiO loading. Meanwhile, the absorption edge of fabricated photocatalysts was found to shift towards the visible region and the bandgap energy was decreased. The photocatalytic reaction was conducted in a continuous-flow reactor under UV irradiation. Methane was identified to be the main product and produced in the order: 10 wt% NiO/TiO2 > TiO2 > 20 wt% NiO/TiO2. The maximum methane yield reached at 4.69 mmol/gcatalyst over 10 wt% NiO/TiO2 and was twice higher than that of P-25. The formation of p-n junction significantly improved the photocatalytic activity of P-25. Furthermore, the proposed schematic diagram for photocatalytic CO2 reduction in the gaseous phase under NiO-TiO2 / UV process was introduced.

In order to verify the performance and safety of the solid-type breeding blanket concept, the thermal conductivity of the pebble bed is required as an essential parameter for design and analysis of the blanket. The hot wire, hot disk, guarded hot plate, and laser flash method are considered as measurement technique for the thermal conductivity of pebble bed. This study aims at the provision of the thermal conductivity of Li2TiO3 pebble bed, which is one of the candidates for tritium breeder material in the solid-type breeding blanket. The laser flash method was adopted due to its advantages compared with other methods, such as high accuracy and repeatability, easy sample preparation, absolute measurement technique, and so on. In this method, the thermal diffusivity is directly measured by the laser flash system, and then the thermal conductivity is obtained by multiplying density and specific heat to the measured thermal diffusivity. The thermal conductivity of the Li2TiO3 pebble bed with packing factor of 57% increased with increasing temperature up to 500 °C and was saturated to 1.3 W/m/K at more than 500 °C.

Dye-sensitized solar cells (DSSCs) are constructed on top of transparent conducting oxide (TCO) substrates that permit incident light to enter the cells and facilitate charge transport from back contact to the external circuit. The most common TCO substrate used in DSSCs, as well as other optoelectronic devices, is an F-doped tin oxide (FTO). Another tin oxide-based TCO is Indium tin oxide (ITO), which is also used in optoelectronic devices. However, zinc oxide-based TCOs –aluminum-doped zinc oxide (AZO) and gallium-doped zinc oxide (GZO) – were not used that much, especially in DSSCs. In the present work, we examined the suitability of four transparent conducting oxides – FTO, ITO, AZO, and GZO – for the application in DSSCs as substrate. We employed all four TCOs to fabricate platinized counter electrode (CE) for DSSCs in three different methods: thermal reduction of Pt precursor at 380 °C, chemical reduction of Pt precursor at 70 °C, and RF-sputtering Pt at room temperature. The cation-doped zinc oxide-based TCOs are not thermally and chemically stable. However, FTO, being anionic-doped tin oxide-based TCO, is the most thermally and chemically stable among the four TCOs studied in this work.

Korea has own programs toward DEMO and fusion reactors that will require further improved DEMO blanket and energy utilization systems. Primary goals of DEMO blanket development in Korea are to develop and verify the integrated blanket design tools; to develop blanket materials, cooling and tritium fuel cycle technologies; and to develop and evaluate fabrication and joining technologies. The concept of helium-cooled ceramic reflector (HCCR) blanket is adopted to be tested in ITER as Test Blanket Module (TBM). Currently, the design and R&D activities are mainly performed through the ITER TBM program in Korea. It is expected to demonstrate the major objectives of the breeding blanket: extraction of heat from burning plasma, tritium self-sufficiency and its integrity within the whole systems considering safety features. Although TBM program will provide very essential data and experience, there will be a considerable technical gap from DEMO blanket. This paper presents the technical gap in the main technical categories of the breeding blanket based on the experience of the development of HCCR TBM and breeding blanket. It is found that still about 60–70% of the DEMO blanket technology can be achieved through the HCCR TBM depending on the technology maturity level, and some ways to DEMO blanket from HCCR TBM are proposed.

The design of diagnostics system for the Helium Cooled Ceramic Reflector (HCCR) Test Blanket System (TBS) has now progressed from generic approaches to the conceptual design integration phases. It is proposed to monitor the temperature, strain, magnetic field strength and neutron flux in selected positions of the corresponding Test Blanket Module (TBM). The temperature can be measured by thermocouple sensors to be integrated for the first wall and breeding zones of TBM. The strain will be monitored by appropriate gauges on the first wall of TBM. Several magnetic pick-up coils could be installed to measure magnetic field strength inside the TBM structure. For the neutron flux monitoring, pairs of Neutron Activation System (NAS) probes and Micro-Fission Chambers (MFCs) would be installed in the TBM structure. In this paper, a brief description on the proposed diagnostics system as well as the key components is presented, and the integration challenges of HCCR TBS diagnostics system are outlined.

Zirconia supported CuO oxygen carriers were prepared for carrying out chemical looping with oxygen uncoupling (CLOU) and chemical looping with air separation (CLAS) operation in a thermogravimetric analyzer (TGA), a fixed bed reactor and a moving bed reactor (MBR). In this study, graphite used as solid fuel for CLOU with CuO/ZrO2 oxygen carriers was also explored in a fixed bed reactor. 40 wt.% CuO/ZrO2 particles sintered at 1000 °C revealed reasonable reactivity without noticeable agglomeration as observed. For fixed bed operation, time required for graphite combustion with CuO/ZrO2 was decreased for experiments conducted at higher reaction temperatures. For experiments carried out in the moving bed reactor, the oxygen concentration and oxygen molar flow rate in the outlet stream can be adjusted by varying operating temperatures, CuO/ZrO2 flow rate, and carrier gas (N2) flow rate. Therefore, moving bed reactors are technically feasible to serve as fuel reactor for chemical looping with air separation.

The redox performances of 1–10 wt% Na-modified Fe2O3/Al2O3 oxygen carrier from seawater were investigated using syngas/air as reactive gases in the thermogravimetric analyzer (TGA) and lab-scaled semi-fluidized bed reactor (semi-FzBR). NaNO3(aq) as the source of sodium dopants to prepare Na-contained solution was implemented by an air atmospheric pressure plasma jet (Air-APPJ) process, which can increase the feasibility of seawater. For the prepared samples, the materials properties, including crystalline phases, surface morphologies, surface areas, and attrition loss performances were well correlated with the Na contents. The results indicated that the poor reduction kinetics and attrition resistance were obtained with the Na adjunction over 5 wt%, attributing to the sintering issue on excessive phases of Na2(Al, Fe)12O19 and Na(Al, Fe)O2 solid solution in the samples. Therefore, the slight incorporation of Na content in the Fe2O3/Al2O3 samples which improved the reduction rate was proved as the candidate oxygen carriers. Particularly, the Na content with 1 wt% in Fe2O3/Al2O3 sample (Na1FA32) can significantly promote the reduction behavior, thermal stability, and attrition resistance as compared to the raw Fe2O3/Al2O3 oxygen carrier. It is environmentally beneficial to use the Na1FA32 as oxygen carrier in a practical chemical looping combustion process.

The typical spatio-temporal evolutions of large-scale weather patterns before and after high-concentration events of particulate matter with an aerodynamic diameter ≤ 10 μm (PM10) (High-PM10) over the Korean Peninsula were investigated. Using the K-means clustering method, five significant large-scale weather patterns associated with High-PM10 events were identified. Among the 91 High-PM10 events that occurred during winter/spring of 2007–2018, approximately 41% (38 cases) belonged to Cluster 1 and 5, characterized by upper-tropospheric downstream amplification of pressure anomaly originating from the Barents/Kara Sea of the Arctic Ocean. We refer to this pattern as the wave-train type. Concurrently with this pattern, southwesterly wind anomalies from southeastern China and significant descending air occurred over the Korean Peninsula, causing PM10 accumulation. Despite its dominance of occurrence, the wave-train type exhibited a relatively shorter mean duration of 1–2 days owing to its rapid development and traveling characteristics. Cluster 2 corresponded to approximately 29% (27 cases) of the total cases, and was characterized by a stagnant anticyclone over the northeastern Eurasia region. In the lower atmosphere, southerly winds dominated the Korean Peninsula. Vertical diffusion of PM10 was restricted by a vertically stable condition in the lower-to-mid-troposphere and a notably weak wind speed. Cluster 2 had the longest duration of 3 days and the highest mean PM10 concentration compared to the other clusters. Cluster 3 corresponded to approximately 13% (12 cases) of the total cases and exhibited a stagnant anticyclone centered at the Kamchatka region. In this case, weakened westerly is observed resulting in the characteristics of a circulation pattern that easily accumulates pollutants. Cluster 4 accounted for approximately 15% (14 cases) of all cases, and is a pattern in which air of PM10 inflows following the back of the cyclone located in the northern part of the Korean Peninsula. We emphasize that most of High-PM10 events occurring over the Korean Peninsula are linked to the preceding upper-tropospheric large-scale circulation patterns. They control the low-level transports and accumulation of pollutants.

Development of the Helium Cooled Ceramic Reflector (HCCR) breeding blanket is underway according to the development strategy of core technology for K-DEMO under the fusion energy development roadmap in Korea. The main goals are to validate integrated design tools and to develop core technologies in the field of materials, manufacturing and joining technologies, helium cooling and tritium technologies, system integration, and safety technologies. A unique graphite reflector concept was adopted to save cost by reducing the amount of beryllium neutron multiplier. The main functions and design concepts of the HCCR breeding blanket are to be verified in ITER through the HCCR Test Blanket Module (TBM) program. Not only breeder modules are to be tested in ITER but also the technologies of cooling, coolant purification, tritium extraction, etc. are to be tested or proved in ITER before employed in DEMO. This paper introduces the current updates of the design and R&D activities of the HCCR TBM systems in the preliminary design stage.

Here, we report on reduced graphene oxide (rGO) electrode prepared by doctor-blading a viscous rGO paste on FTO substrate followed by sintering at 500 °C in argon and its application as a counter electrode (CE) of dye-sensitized solar cells (DSSCs). The paste was prepared by mixing rGO and ethyl cellulose in terpineol. The rGO was prepared from commercially available graphite flakes, which were first oxidized to graphene oxide (GO) by modified Hummers’ process and then the GO was reduced to rGO with hydrazine. Electrochemical analyses – cyclic voltammetry and electrochemical impedance spectroscopy – suggest that the performance of the rGO electrode towards I−/I3− is comparable to that of Pt electrode. Even though the catalytic performance of the rGO film towards the reduction of triiodide was not as good as thermally decomposed Pt electrodes, the overall series resistance of the rGO-based cell was similar to that of the Pt-based cell. When applied to DSSCs as a CE, the rGO electrode performs like a Pt electrode showing the prospect of replacing Pt with a metal-free all-carbon material.

Since the stress due to the thermal load on breeding blanket structure is one of the main design driver, the thermal conductivity is necessary input data for thermal-structural and thermo-hydraulic analyses performed in order to understand the heat transfer phenomena and estimate the thermal stress. Since for the functional materials of solid type breeding blanket a pebble-bed form is mainly adopted instead of a bulk form such as a block or a disk, it should be needed to measure the thermal conductivity of pebble-bed. In this study, the effective thermal conductivity of pebble-bed is measured by laser flash method, which is one of the various thermal conductivity measurement methods, because this method has several advantages such as a wide thermal conductivity range of the measurement and a small amount of pebbles. A sample holder considering the heat transfer mechanism from the laser source to pebble-bed has been specially designed in order to apply the laser flash technique to the pebble-bed sample and it has been validated by the experiments. This paper introduces preliminary results of the effective thermal conductivity on the pebble-bed using this sample holder.

The use of seawater as catalytic agents for hematite (Fe 2 O 3 ) as oxygen carrier in chemical looping combustion process is attractive, because of its abundance and low cost. Unfortunately, seawater itself with major NaCl compound under reactive species accompanying the volatilization of chlorine-containing gases probably lead to the corrosion on reactors during the combustion process. In this study, the feasibility evaluation of sodium dopants extracted from seawater as an effective catalytic agent via an air atmospheric pressure plasma jet (Air-APPJ) is performed, and as such it is combined with Fe 2 O 3 /Al 2 O 3 to assess any possible enhancement on the reduction kinetics. The sodium-contained solutions, NaNO 3(aq) and NaCl (aq) , as precursors are used to prepare the sodium dopants due to the evaporation-decomposition of water and dissolved salts via plasma discharge reaction. The sodium-modified Fe 2 O 3 /Al 2 O 3 oxygen carrier can significantly promote the efficiency of the carbon capture efficiency and CO 2 yield. Especially for the NaCl (aq) as precursor in an Air-APPJ system, the high carbon capture efficiency, CO 2 molar fraction and CO 2 yield around 0.96, 0.95 and 0.91 after fifty redox cycle for the sodium-modified Fe 2 O 3 /Al 2 O 3 oxygen carrier are achieved. It can be anticipated that the sodium-modified Fe 2 O 3 /Al 2 O 3 from seawater by an Air-APPJ system as an oxygen carrier candidate in a reversible CLC process would be notably attractive.

Chemical looping and chemical-looping with oxygen uncoupling processes using CuO oxygen carriers are demonstrated to be novel and efficient with inherent separation of CO2. However, liquid-sintering occurred during the application of CuO is confirmed to significantly reduce its reactivity. Hence, ZrO2 was employed as support for CuO in this study to diminish agglomeration of CuO particulates during chemical looping operations. Experimental results demonstrated that CuO/ZrO2 oxygen carriers contain 40 to 60% ZrO2 exhibited adequate mechanical strength and reactivity for syngas combustion. The supplement of 1% starch as pore-forming agent to CuO/ZrO2 oxygen carriers could not only maintain the mechanical strength, but also improve the oxygen carrier conversion for CLOU process.

The effect of controlled periodic illumination on the photonic efficiency and temporal decomposition behavior of dimethyl phthalates (DMP) in aqueous solution by UV–LED/TiO 2 process was investigated in this study. For experiments conducted with the same total illumination time, the decomposition of DMP was enhanced with increasing dark period possibly ascribed to the enhancement of surface replenishment and the inhibition of electron–hole recombination. The existence of oxygen molecules might be beneficial for replenishing the TiO 2 surface during the dark periods. Experiments conducted with longer illumination might not be favorable to enhance DMP decomposition, instead was more favorable for electron-hole recombination. Photocatalytic decomposition of DMP by UV–LED/TiO 2 process under periodic illumination was agreeably modeled by the proposed Langmuir–Hinshelwood kinetic equation. Under the same illumination period of 5 s, the calculated energy consumption per order was decreased by more than 40% for experiments conducted with the increasing dark period from 0.5 to 5.0 s; thus, the electric energy consumption was substantially decreased.

Using a conceptual design of the Korean helium cooled ceramic reflector (HCCR) test blanket module (TBM) including the TBM-shield for testing in ITER, a structural analysis with electro-magnetic (EM) loads is performed. From a previous analysis of the material magnetization due to the use of reduced activation ferritic-martensitic (RAFM) steel as the TBM structure material and EM analysis considering the major disruption of MD-I, MD-II, and MD-IV, the forces are obtained and used for the current structural analysis. The results indicate that the maximum stress occurs at the He purge line at the upper and lower region of the breeding zone (BZ) box including the graphite reflector region, which meets the design requirement. In addition, displacements are lower than the designed gaps from the TBM port plug (PP) frame. The results are provided to the load combination analysis.

The application of controlled periodic illumination (CPI) using ultraviolet light-emitting diodes (UV-LED) for the photocatalytic reduction of CO2 in the aqueous phase was investigated in this study. The experiments were conducted with P-25 TiO2 as photocatalyst under the UV light intensity of 160 mW/cm2 with 60 min of total illumination time and pH 2. The target product of the photocatalytic reduction of CO2 by UV-LED process was methanol with the highest selectivity of 28.31 %. The reduction efficiency of CO2 and the reaction rate reached the highest value of 86.31 % and 15.76 × 10−5 M min−1, respectively, for experiment conducted with the smallest duty cycle of 0.09. The photonic efficiency was enhanced from 0.47 % to 2.7 % with decreasing duty cycle from 1.00 to 0.09. The electric energy saving increased significantly from 13.11%–93.34%, including with a decrease of electric energy per order from 139.68 to 10.71 kW h m-3 order-1 for experiments conducted with decreasing γ from 0.91 to 0.09. The photocatalytic reduction of CO2 in the aqueous phase was well modeled by the Langmuir-Hinshewood kinetic equation. Furthermore, the proposed mechanism for photocatalytic CO2 reduction in aqueous phase under CPI was introduced.

Rice husk used as solid fuel for chemical looping combustion (CLC) with Fe2O3/Al2O3 oxygen carriers was investigated in an annular dual-tube moving bed reactor (ADMBR). Nearly 100% of CO2 concentration and 92% fuel conversion were achieved for rice husk combustion conducted with Fe2O3/Al2O3 mass flow rates of 22.7 g/min. The introduction of rice husk/sawdust and rice husk/charcoal and mixtures enhanced the processing capacity because of the higher carbon content. The heat demands for ADMBR were estimated to be roughly 54% of input processing capacity released for both rice husk and rice husk/sawdust gasification, while about 19% of input processing capacity was released for rice husk/charcoal gasification. ADMBR is technically feasible to be served as the fuel reactor for rice husk combustion by CLC to achieve high fuel conversion under appropriate operating conditions without auxiliary fuel.

Korean Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM) will be installed at the #18 equatorial port of the Vaccum Vessel in order to test the feasibility of the breeding blanket performance for forthcoming fusion power plant in the ITER TBM Program. Since ITER tokamak contains Vaccum Vessel and set of electromagnetic coils, the TBM as well as other components is greatly influenced by magnetic field generated by these coils. By the electromagnetic (EM) fast transient events such as major disruption (MD), vertical displacement event (VDE) or magnet fast discharge (MFD) occurred in tokamak system, the eddy current can be induced eventually in the conducting components. As a result, the magnetic field and induced eddy current produce extremely huge EM load (force and moment) on the TBM. Therefore, EM load calculation is one of the most important analyses for optimized design of TBM. In this study, a 20-degree sector model for tokamak system including central solenoid (CS) coil, poloidal field (PF) coil, toroidal field (TF) coil, vaccum vessel, shield blankets and TBM set (TBM, TBM key, TBM shield, TBM frame) is prepared for analysis by ANSYS-EMAG tool. Concerning the installation location of the TBM, a major disruption scenario is particularly applied for fast transient analysis. The final goal of this study is to evaluate the EM load on HCCR TBM during plasma major disruption.

In this work, a simple and a straight-forward approach to derive the parameters of dye-sensitized solar cells (DSSCs) in terms of single diode model is discussed. The parameters are extracted exclusively from single current density–voltage (j–V) curve with some common assumptions. The technique does not require smoothing of the j–V curve by means of polynomial fitting as well as iterative calculation of the diode model equation. The data obtained from this method are compared with that obtained from least square fitting and the combined analyses of electrochemical impedance spectroscopy (EIS) and j–V data for two different DSSCs. The method is suitable for routine analysis of DSSCs.

Peri-implantitis is similar to periodontitis in both symptoms and treatment; however, their level of similarity remains controversial. Here, we compared multiple cases of periodontitis and peri-implantitis through transcriptome and methylome profiling, and analyzed the effects of smoking as a typical risk factor. Human gingival tissues were obtained from 20 patients with periodontitis or peri-implantitis via periodontal surgical procedures. Total RNA and genomic DNA were isolated, and transcriptome and methylome datasets were generated. Comprehensive analysis of differential gene expression, DNA methylation, and protein-protein interactions indicated that periodontitis and peri-implantitis share biological similarities; however, hierarchical clustering between the two disease groups revealed distinct molecular characteristics. These differences might be related to structural differences in natural tooth-bone and implant-bone. Additionally, smoking differentially affected periodontitis and peri-implantitis in terms of host-defense mechanism impairment. Within the limitations of this study, the results provide evidence that peri-implantitis is distinct from periodontitis and that smoking potentially affects disease progression. Our study provides a foundation for the rational design of a large-scale study in the future for a more comprehensive analysis that includes microbiome and clinical data.

Polyurethane (PU) and polypropylene (PP) particles were evaluated as solid fuels in chemical looping combustion (CLC) for treatment of waste plastics as well as power generation. An annular duel-tube moving bed reactor (ADMBR) was used as fuel reactor for decomposition and combustion of PU and PP particles. CO and H 2 were the major components of fuel gas generated by decomposition of PU and PP particles in the ADMBR. Complete conversion of plastic particles and 100% CO 2 yield of fuel gas were achieved as oxygen carrier-to-fuel ratio of PU and PP particles reached 1.86 and 6.56, respectively. The heat demands for ADMBR were calculated to be 21% and 52% of output processing capacity by heat consumptions of fuel decomposition in the fuel reactor of CLC system, respectively. ADMBR is technically feasible as fuel reactor for PU and PP combustion to achieve high conversion efficiency without auxiliary fuel by CLC.

Korea has decided to test Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM) in ITER and design of the TBM with its ancillary systems, i.e. Test Blanket System (TBS), is under progress. Since the TBM is operated at elevated temperature with high heat load, safety consideration is essential in design procedure. In this paper, preliminary accident analysis results for the current HCCR TBS design on selected scenarios are presented as an important part of safety assessments. To simulate transient thermo-hydraulic behavior, GAMMA-FR code which has been developed in Korea for fusion applications was used. The main cooling and tritium extraction circuit systems, as well as the TBM, were simulated and the main components in the TBS were modeled as the associated heat structures. The important accident scenarios were produced and summarized in the paper considering the HCCR TBS design and ITER conditions, which cover in-vessel Loss Of Coolant Accident (LOCA), in-box LOCA, ex-vessel LOCA, Loss Of Flow Accident (LOFA), Loss Of Heat Sink Accident (LOHSA) and purge pipe rupture case. The accident analysis based on the selected scenarios was performed and it was found that the current design of the HCCR TBS meets the thermo-hydraulic safety requirements.

Korea plans to test a Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM) in ITER. The HCCR TBM adopts a four sub-module concept considering the fabricability and the transfer of irradiated TBM for post irradiation examination. Each sub-module has seven-layer breeding zone, including three neutron multiplier layers packed with beryllium pebbles, three lithium ceramic pebble bed packed tritium breeder layers, and a reflector layer packed with graphite pebbles. Based on this configuration, neutronic and electromagnetic calculations were performed and their results were applied for the conceptual design of HCCR TBM that considers manufacturing feasibility. Also, a design and safety analysis of HCCR Test Blanket System (TBS) was performed using integrated design tools modifying nuclear system codes for helium coolant and tritium behavior evaluation. The Advanced Reduced Activation Alloy (ARAA) is being developed as a structural material. A total of 73 candidate ARAA alloys were designed and their out-of-pile performance was evaluated. The graphite pebbles as the neutron reflector were fabricated by using mechanical machining and grounding method with the surface coated with SiC. The hydrogen permeation characteristics of structural materials were evaluated using the Hydrogen PERmeation (HYPER) facility. The recent design and R&D progress on these areas are addressed in this paper.

Fe2TiO5 was studied for the reduction mechanism in chemical looping process. Fe2TiO5 pellets were reduced by syngas that demonstrated highest reduction rate in the beginning of reduction period from Fe2TiO5 to FeTiO3 and Fe2TiO4. The reduction of Fe2TiO5 is suggested in sequence from Fe2TiO4, FeTiO3 to Fe. Fe2TiO5 pellets performed reasonable reactivity and steady recyclability after continuous 100 redox cycles. The increased surface area and decreased mechanical strength for pellets operated after 30 redox cycles was due to formation of cracks and porous structures. Moreover, Fe2O3/TiO2 was the major crystalline phase existed in the pellets after 30 redox cycles. Fe2TiO5 attributed high syngas conversion in the fixed bed reactor due to high equilibrium constants. The completed reduced form of Fe2TiO5 oxygen carriers, Fe/TiO2, demonstrated hydrogen generation by steam oxidation, and the Fe was oxidized to Fe3O4 and FeTiO3 in the fixed bed reactor.

Chemical-looping combustion (CLC) of fossil fuel has a potential to generate power with achieving the inherent CO2 capture by means of an oxygen carrier (OC) that is circulated between air and fuel reactors. In this article, a composite oxygen carrier with highly redox reactivity for chemical-looping combustion process was first synthesized using nickel nitrate and iron nitrate as precursors in a sol–gel process, respectively. Materials characterization of the prepared OC samples were investigated by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area measurements, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX). The reactivity of the oxygen carrier in CLC process was evaluated by a thermogravimetric analyzer by alternating methane and air. The prepared nickel–iron composites oxygen carrier exhibited excellent oxygen-transfer capability both in the fuel and air reactors than pure Fe2O3, NiO, NiFe2O4, and physically mixed Fe2O3–NiO samples. The synergistic effect between Fe and Ni cations can enhance the reduction rate of iron oxide; meanwhile, it also improves the oxidation reaction rate of metallic nickel. The different migration behaviours of iron and nickel under the reducing and oxidizing atmospheres were observed by XRD and EDX, respectively. Finally, twenty-cycles of redox reaction demonstrated that composites oxygen carrier loaded on the SiC inert support had excellent redox activity and sintering resistance and consequently was capable of the CLC process.

Fe 2 O 3 /Al 2 O 3 composite oxygen carriers were prepared for chemical looping combustion (CLC) with methane in a lab-scale moving bed fuel reactor provided with reasonable crush strength, reactivity and recyclability. Carbon formation was observed during the combustion process in the empty bed at 900 °C through methane decomposition reaction, and was enhanced for experiments conducted with increased retention time. Carbon formation was obviously reduced for experiments conducted in the moving bed fuel reactor with oxygen carrier-to-fuel ratio ( ϕ ) higher than 1.14. The oxygen carriers that moving out of the moving bed reactor were composed of mainly FeO and FeAl 2 O 4 , characterized by X-ray diffraction (XRD) analysis. The formation of FeO and FeAl 2 O 4 indicated that further utilization of oxygen in iron-based oxygen carriers can be achieved by moving bed operation.

The reactivity and high fuel conversion efficiency of metal oxide as oxygen carrier are two of the most important functions that can be research in order to make chemical looping combustion (CLC) a reality. In this study, oxygen carriers of Fe 2 O 3 , supported by titanium oxides were prepared to evaluate the feasibility as oxygen carriers for chemical looping by thermogravimetric analyzer (TGA), as well as gas conversion in a fixed bed reactor (FBR). Supported Fe 2 O 3 oxygen carriers and sintered in air at 1100C is a suitable preparation parameter to demonstrate reasonable oxygen conversion. The reduction mechanism of supported Fe 2 O 3 oxygen carriers were proposed in accordance with TGA and x-ray diffraction analysis (XRD) characterizations. Fe 2 TiO 5 and inherent TiO 2 as supporting material would be formed and carried on FBR in practical operation. The preparation of FT-03 (80% Fe 2 O 3 and 20% TiO 2 ) oxygen carrier demonstrated high CO 2 yields regarding to syngas (10% H 2 and 10% CO in N 2 ) and methane (10% CH 4 in N 2 ) combustion in FBR, operated at temperatures higher than 500 and 900C, respectively. Moreover, great mechanical strength and reasonable reactivity of supported Fe 2 O 3 oxygen carriers were also examined by texture analyzer with well-suited for used in CLC.

We evaluate electromagnetic (EM) loads on the main systems of the ITER machine using a single finite element model. The 20° sector of the full ITER machine includes the main in-vessel components as well as the vacuum vessel. Narrow slits of the in-vessel components are effectively modeled by using the element splitting method without significant increase of computation memory and time as well as without sacrificing the accuracy. Furthermore, the halo current is taken into account at the same time together with the plasma current. To apply both currents concurrently, dedicated conversion codes are utilized to transfer the plasma simulation results by DINA to the electromagnetic analysis by ANSYS-EMAG used here. The electromagnetic loads on the ITER machine are calculated for various disruption scenarios. Investigation on the analysis results is made to find the worst plasma disruption case and the design-driving load component for each system as well as to compare load contribution from eddy and halo currents. The effect of the narrow slits on load reduction is also examined.

Recently Korea has decided to test helium cooled ceramic reflector (HCCR) concept for ITER test blanket module (TBM) which will be inserted in TBM frame in dedicated ITER equatorial port. As the previous design was performed based on the TBM frame with the horizontal opening and the openings of all the TBM frames have been changed to vertical orientation, design change to vertical configuration is inevitable. This design change has significant impact on the TBM performance and design parameters. Therefore, new design iteration is required. In this paper, the updated design of the Korean HCCR TBM to vertical configuration is presented. While maintaining the main feature of employing graphite reflector, the new vertical HCCR TBM with four sub-modules was proposed considering manufacturability and post irradiation examination aspect. Various performance analyses have been performed to optimize the design. Current design and performance results including nuclear, thermo-hydraulic and thermo-mechanical analyses results are introduced.

Korea plans to install and test Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM) in the ITER, because the HCCR blanket concept is one of options of the DEMO blanket. Currently, many design and R&D activities have been performed to develop the Korean HCCR TBM. An integrated design tool for a fusion breeder blanket has been developed based on nuclear technologies including a safety analysis for obtaining a license for testing in the ITER. A half-scale sub-module mockup of the first wall with the manifold was fabricated, and the manufacturability and thermo-hydraulic performances were evaluated. High heat load and helium cooling test facilities have been constructed. Next, the recent status of TBM material development in Korea was introduced including Reduced Activation Ferritic Martensitic (RAFM) steel, lithium ceramic pebbles and silicon carbide (SiC) coated graphite pebbles. Several fabrication methods of RAFM steel, lithium ceramic pebbles, and silicon carbide coating on graphite pebbles were investigated. Recent design and R&D progress on these areas are introduced here.

Photocatalytic decomposition of isopropanol (IPA) presented in gas stream was investigated using a continuous, tubular photoreactor loaded with single TiO 2 -coated optical fiber under controlled UV periodic illumination. The TiO 2 particles were coated on optical fiber through dip-coating process. The introduction of humidity retarded the decomposition of IPA because of the competition between water and IPA molecules for the active sites on TiO 2 surface. Operated at retention time of less than one second, about 21% isopropanol was decomposed for experiments conducted with initial isopropanol concentration of 10 ppmv. The apparent quantum yield was increased from 0.78 to 1.28 for experiments conducted with UV-LED as the light source operated at duty cycle shifted from 1.0 to 0.1. At the operation of equivalent duty cycle, both removal efficiencies and quantum yield were also enhanced in the highly frequent periodic illumination by decreasing both light and dark periods.

The aim of this study is to fabricate TiO 2 nanotubes arrays (TNTs) with smooth homogenous morphology by the anodization of titanium foil in fluorine-contained electrolytes. A series of materials analysis techniques, such as field-emission scanning electron microscopy, potentiostat/galvanostat and X-ray diffractometer, are used to characterize the surface morphology, phase formation, lattice parameters and the induced photocurrent intensity of TNTs. As the experimental results, the tube dimension of TNTs is found to be determined by the migration and diffusion of ions in the electrolyte corresponding to the concentration profiles of oxygen-containing anionic species and hydrogen ions within the TiO 2 nanotubes. High-aspect-ratio TNTs with a superior degree of regularity and homogeneity are favored to be formed in the fluoride-contained ethylene glycol solutions due to the suppression of pH bursts and local ions concentration fluctuations during anodization in the highly viscous electrolytes. To compare the NO reduction by photo-SCR using spherical TiO 2 (P25) and tubular TiO 2 , the performance of NO reduction by photo-SCR is significantly affected by the available surface area (active sites) of TiO 2 rather than the crystal composition of TiO 2 .

Objective To evaluate the effect of a medication therapy management (MTM) intervention on adverse drug events (ADEs), health care visits, and drug-related problems (DRPs). Design Randomized, controlled, clinical trial. Setting Academic medical center community pharmacies and family medicine clinics at three U.S. sites between December 2007 and January 2010 Patients Individuals aged 65 years or older with three or more chronic illnesses, six or more prescription medications, and at risk for a DRP. Intervention At 0 and 3 months, pharmacists conducted comprehensive medication reviews and screened for and resolved DRPs through patient education and recommendations to physicians. Main outcome measures Frequency of ADEs reported by patients and confirmed by clinical algorithm, health care visits at 3 and 6 months, and number of DRPs, pharmacist recommendations, and medication discrepancies. Results 637 participants enrolled. No differences were observed in potential ADEs or health care visits among the usual care and MTM groups. DRPs declined in both MTM intervention groups over time. Physicians responded to 54.6% of pharmacist recommendations. Enhanced MTM patients had fewer medication list discrepancies than basic MTM patients (33.8% vs. 47.1%, P Conclusion This specific design of MTM was associated with reduced DRPs but did not reduce potential ADEs or health care visits.

Several R&Ds are being performed for Korean helium cooled solid breeder (HCSB) test blanket module (TBM) in the field of hydrogen isotopes permeation characteristics measurement in the helium purge line, joining technologies of structural materials, breeder pebble materials development, and the measurement of pebble bed characteristics. Electron beam welding for reduced activated ferritic–martensitic (RAFM) steel is evaluated to find optimal welding conditions. Also, a hydrogen permeation measurement apparatus is newly installed for the evaluation of the permeation barrier characteristics of stainless steel and RAFM steels. Two fabrication methods of lithium orthosilicate pebbles are investigated using slurry droplet methods. As methods of silicon carbide coating on the graphite pebble, microwave coating and chemical vapor deposition coating are evaluated. Two apparatuses are established to assess the thermo-mechanical properties of graphite and breeder pebble beds. The current status of R&D activities on these areas is introduced and the main progresses are addressed in this paper.

The catalytic enantioselective electrophilic chlorination promoted by chiral palladium complexes is described. The treatment of β-keto esters with 2,3,4,5,6,6-hexachlorocyclohex-2,4-dienone as chlorine source under mild reaction conditions afforded the corresponding α-chlorinated β-keto esters with excellent enantioselectivities (up to 94% ee).

This study was performed to investigate the relationships between disk displacement, joint effusion, and degenerative changes in patients with temporomandibular disorders using MRI. Randomly selected MRIs of 508 temporomandibular joints of 254 patients (92 males and 162 females, mean age was 30.5±12.0 years) were reviewed retrospectively. Seventy-eight percent (198 out of 254) of the patients complained of joint pain. Compared with joints with a normal disk position, the joints with anterior disk displacement with reduction showed a 2.01 odds ratio (P

Electromagnetic (EM) loads due to eddy current and halo current during plasma disruptions are evaluated for the ITER diagnostic upper port plug. To reduce strong EM loads acting on the port plug fixed to the vacuum vessel like a cantilever beam, three design options have been considered: removal of the diagnostic first wall, slitting of the diagnostic shield module and recess of the port plug. The main focus of the present study is to examine the efficacy of these options in terms of EM loads on the upper port plug. It is found that making slits is more effective than removing the first wall. It is also shown that the upper port plug needs to be recessed to reduce the EM load induced by halo current.

R&D activities currently being undertaken for Korean Helium Cooled Solid Breeder (HCSB) Test Blanket Module (TBM) include joining technologies of structural materials, breeder pebble material development, and measurement of pebble bed characteristics. The joining performance of ferritic–martensitic steel is evaluated. TIG welding for ferritic–martensitic steel is evaluated to find welding conditions with two different current modes. The fabrication methods of lithium silicate powder and lithium titanate pebble are under development using special process. The Li2TiO3 pebbles showing an average diameter of 1.8 mm was fabricated by water-based sol–gel method. The Li4SiO4 powder with the particle size of about 200 nm was synthesized by PVA polymer solution method. The method of silicon carbide coating on the graphite pebble is investigated, and its possibility is verified based on the coating results on the graphite plate. Sputtered SiC coating layer was crystallized by high temperature heat treatment. The measurement method and database of the thermal properties of the pebble and pebble bed are important for the design of TBM as well as breeding blanket. The initial characteristics of the pebbles are assessed measuring the effective thermal diffusivity of graphite pebble by laser flash method.

Thermo-hydraulic design of test blanket module (TBM) is challenging in that each component of TBM should be properly controlled within narrow temperature margins in the extreme conditions such as high heat flux from plasma and volumetric heat generation due to neutron irradiation. This paper presents thermo-hydraulic analysis results on the Korean helium cooled solid breeder (HCSB) TBM with the updated design. In the previous study, computation was performed on the TBM model with assumption that the coolant is uniformly distributed at back manifolds, without including the back manifolds in the computational model. In the present study, the updated configuration of the back manifolds is introduced. Flow distribution in each manifold is investigated as well as flow characteristics. Then, thermo-hydraulic analysis on the TBM model is carried out with flow distributions calculated from the flow analysis results on the back manifolds. It is found that the current manifolds are reasonably designed so that the TBM components are effectively cooled against associated thermal loads.

Korea is developing a Helium Cooled Solid Breeder Test Blanket Module for ITER. The primary candidate structural material is a Reduced Activation Ferritic/Martensitic steel. The complex TBM structure requires developing joining technologies for successful fabrication. The characteristics of Tungsten Inert Gas welding and Hot Isostatic Pressing joining of RAFM steel were investigated. Metallurgical examinations showed that the steel grain size was increased after HIP joining and recovered by post joining heat treatment. Both TIG welding and HIP joining are found to be acceptable for ITER TBM based on mechanical tests and microstructure examination.