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Purpose: The purpose of this prospective study was to assess the change of marginal bone level around three different types of external-hex implants after 5 years using radiography. Materials and Methods: Included in this study were 54 patients randomly put into three different groups; rough-surface implants (Branemark), machined coronal aspect implants (Restore), and microthreaded coronal aspect implants (Hexplant). Clinical and radiographic assessments were performed contemporaneously with implant loading (baseline) and at 1, 3, and 5 years post-functional loading. A mixed-model analysis was employed to examine mean marginal bone change significance in the three treatment groups. Results: In a total of 31 out of 54 patients, 81 of 135 implants remained to the end of the study. At 5 years, the microthreaded coronal aspect implants had 0.61 ± 0.32 mm mean crestal bone loss; the rough-surface implants without microthread, 0.99 ± 0.38 mm; and the machined coronal aspect implants, 1.06 ± 0.39 mm. The rough-surface implants and the machined coronal aspect implants did not exhibit statistically significantly different marginal bone loss, whereas the microthreaded coronal aspect implants exhibited significantly less marginal bone loss (P = .0015). Conclusion: In this research, rough-surface implants with microthreads showed positive long-term effects in preserving peri-implant bone level against functional loads when compared with implants lacking these aspects at the coronal part. Most of the bone loss was shown within 1 year of loading, and all types of implants stabilized after 1 year.

Purpose This article describes a case of the successful non-surgical management of a periodontally compromised maxillary premolar. Methods A combination therapy, including root planing, occlusal adjustment, and tooth splinting, was applied. Clinical and radiographic examinations were performed during the 16-month follow-up period. Results All periodontal parameters were improved. There were dramatic decreases (3–6 mm) in the probing pocket depth, tooth mobility, and marginal bone loss. Interestingly, gradual resolution of the periapical radiolucency and alveolar bone regeneration were observed in the radiographs, and the periodontal condition was maintained during the follow-up period. Conclusions Within the limits of this study, these results demonstrate the importance of natural tooth preservation through proper periodontal treatment and occlusal adjustment of the periodontally compromised tooth, which is typically targeted for tooth extraction and dental implantation., Graphical Abstract

It is widely accepted that sandblasted/large-grit/acid-etched (SLA) surfaces of titanium (Ti) have a higher osteogenic potential than machined ones. However, most studies focused on differential gene expression without elucidating the underlying mechanism for this difference. The aim of this study was to evaluate how the surface roughness of dental Ti implants affects their osteogenic potential. Mouse preosteoblast MC3T3-E1 cells were seeded on machined and SLA Ti discs. The cellular activities of the discs were analyzed using confocal laser scanning microscopy, proliferation assays, and real-time polymerase chain reaction (PCR). DNA methylation was evaluated using a methylation-specific PCR. The cell morphology was slightly different between the two types of surfaces. While cellular proliferation was slightly greater on the machined surfaces, the osteogenic response of the SLA surfaces was superior, and they showed increased alkaline phosphatase (Alp) activity and higher bone marker gene expression levels (Type I collagen, Alp, and osteocalcin). The degree of DNA methylation on the Alp gene was lower on the SLA surfaces than on the machined surfaces. DNA methyltransferase inhibitor stimulated the Alp gene expression on the machined surfaces, similar to the SLA surfaces. The superior osteogenic potential of the SLA surfaces can be attributed to a different epigenetic landscape, specifically, the DNA methylation of Alp genes. This finding offers novel insights into epigenetics to supplement genetics and raises the possibility of using epidrugs as potential therapeutic targets to enhance osteogenesis on implant surfaces.

Purpose This study aimed to evaluate the effectiveness of the partial split-flap technique with a K-incision on vertical guided bone regeneration (vGBR) and to retrospectively analyze the clinical and radiographic outcomes of dental implantation using this approach. Methods In total, 78 patients who received 104 dental implants with vGBR, categorized as (1) pre-GBR and post-implantation and (2) simultaneous GBR and implantation, were enrolled. Data analysis was based on periapical radiographs, clinical photos, and dental records. The 2-sample t-test was used to compare the 2 surgical procedures. Results The baseline vertical bone level, augmented bone height (ABH), and treatment duration were significantly higher in the pre-GBR procedure group. The survival rates of the implants were 96.1% and 94.8% in implant- and patient-based analyses, respectively. In Cox regression analysis, high rates of implant failure were found in the presence of ABH of ≥4 mm, smoking, and diabetes. Conclusions Within the limitations of this retrospective study, the partial split-flap technique using a K-incision for vGBR showed stable clinical outcomes and favorable dental implant survival., Graphical Abstract

Purpose Direct intraoral scanning and superimposing methods have recently been applied to measure the dimensions of periodontal tissues. The aim of this study was to analyze various correlations between labial gingival thickness and underlying alveolar bone thickness, as well as clinical parameters among 3 tooth types (central incisors, lateral incisors, and canines) using a digital method. Methods In 20 periodontally healthy subjects, cone-beam computed tomography images and intraoral scanned files were obtained. Measurements of labial alveolar bone and gingival thickness at the central incisors, lateral incisors, and canines were performed at points 0–5 mm from the alveolar crest on the superimposed images. Clinical parameters including the crown width/crown length ratio, keratinized gingival width, gingival scallop, and transparency of the periodontal probe through the gingival sulcus were examined. Results Gingival thickness at the alveolar crest level was positively correlated with the thickness of the alveolar bone plate (P, Graphical Abstract

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.

BACKGROUND The purpose of this study was to compare the survival rates of implants placed following 1-stage or 2-stage maxillary sinus floor augmentation by the lateral window technique (SFALW) performed on residual bone of

To quantify the frequency and type of medication decisions on discharge from the hospital to hospice care.Retrospective cohort study.A 544-bed academic tertiary care hospital in Portland, Oregon.A total of 348 adult patients (age ≥18 y) discharged to hospice care between January 1, 2010, and December 31, 2016.Data were collected from an electronic repository of medical record data and a manual review of patients' discharge summaries. Our outcomes of interest were the frequency and type of medication decisions documented in patients' discharge summaries. Medication decisions were categorized as continuation, continuation but with changes in dose, route of administration, and/or frequency, discontinuation, and initiation of new medications. We also collected data on the frequency of patient/family in the participation of medication-related decisions.Patients were prescribed a mean of 7.1 medications (standard deviation [SD] = 4.8) on discharge to hospice care. The most prevalent medications prescribed on discharge were strong opioids (82.5%), anxiolytics/sedatives (62.9%), laxatives (57.5%), antiemetics (54.3%), and nonopioid analgesics (45.4%). However, only 67.8% (213/341) of patients who were prescribed an opioid on discharge to hospice care were also prescribed a laxative. Discharging providers made a mean of 15.0 decisions (SD = 7.2) per patient of which 28.5% were to continue medications without changes, 6.7% were to continue medications with changes, 30.3% were to initiate new medications, and 34.5% were to discontinue existing medications. Patients and/or family members were involved in medication decisions during 21.6% of discharges; patients were involved in 15.2% of decisions.Patients averaged more than 15 medication decisions on discharge to hospice care. However, it was rarely documented that patients and/or their families participated in these decisions. J Am Geriatr Soc, 2019.

Iron-based oxygen carriers supported on alumina or alumina/titania were prepared and evaluated for chemical looping combustion of methane. The reduction conversion of Fe

Purpose Periodontitis and rheumatoid arthritis (RA) share a similar inflammatory pathogenesis. Porphyromonas gingivalis (Pg) can induce anticyclic-citrullinated peptide autoantibodies (anti-CCP antibodies), a key factor in the development of RA. This study aimed at evaluating the relationships between the 2 diseases and identifying the clinical implications thereof, with a focus on periodontal pathogens in Korean adults. Methods A total of 260 RA patients and 86 age- and sex-matched control patients without arthritis were enrolled in this prospective cross-sectional study. Periodontal indices and the prevalence and amount of periodontal pathogens were compared between the groups. Correlations between periodontal and RA indices were examined, as were correlations between 9 periodontal pathogens and RA indices. Results The RA group had significantly higher values than the control group for all investigated periodontal indices (P, Graphical Abstract

자주박격포는 보병에 의해 운용되는 도수운반 박격포와 달리 박격포를 전투차량에 탑재한 무기 체계이다. 자주박격포는 도수운반 박격포에 비해 Key Words: Self-Propelled Mortar(자주박격포), Multibody Dynamic Analysis(다물체동역학 해석), Interior Ballistic(강내탄도학), External Ballistic(강외탄도학), Accuracy of Fire(사격정확도) 초록: 본 연구에서는 자주박격포의 다물체동역학 모델을 만든 뒤, 포탄의 탄도학을 고려하여 시뮬레이션 하였다. 자주박격포 모델은 박격포 모델 및 차량 모델로 구성하였으며, 상용 다물체 해석 프로그램인 RecurDyn 을 사용하였다. 차량 모델은 6 자유도 강체플랫폼으로 모델링 하였으며, 박격포 발사 직후의 움직임에는 강내탄도학을 적용하였다. 강내탄도학 해석의 결과를 바탕으로, 포신을 떠난 후의 강외탄도 해석을 수행하였다. 몬테카를로 기법을 활용한 반복 해석으로 발사각과 차량 동특성에 의한 변동이 고려된 탄착점의 분산도를 구하여 사격정확도를 제시하였다. Abstract: For this research, the trajectory of a projectile was simulated via the multibody dynamics analysis of a self-propelled mortar. The dynamic model was composed of a mortar model and a vehicle model, and was simulated using the RecurDyn program. Interior ballistic was applied to the mortar model, and exterior ballistic was conducted by Matlab using the simulation results of the interior trajectory. Through repetitive Monte-Carlo simulations, the accuracy of the mortar was analyzed by considering variations in the aiming angle and vehicle dynamic response.

Charcoal used as solid fuel for chemical looping gasification (CLG) with Fe2O3/Al2O3 oxygen carriers was investigated in an annular dual-tube moving bed reactor (ADMBR). Pure CO2 and steam/CO2 mixture were used to gasify the charcoal in a fixed bed reactor. More combustible gases, CO and H2, were observed in the outlet gas streams for charcoal gasification conducted with steam/CO2 mixture than those with only CO2. The yields of fuel gases were determined to modify the equation of oxygen carrier-to-fuel ratio (ϕ) for moving bed operation. More CO and H2 were generated for charcoal gasification conducted in the moving bed reactor operated with higher oxygen carrier-to-fuel ratios. The heat demand for experiment conducted in the ADMBR was calculated to be 60% of output processing capacity due to the heat consumptions of fuel gasification. In sum, ADMBR is technically feasible to be a fuel reactor for partial oxidization of charcoal by CLG to achieve syngas production under appropriate operating conditions without auxiliary fuel.

The reduction mechanisms of three iron titanium based oxygen carriers with H2 have been investigated by experimental and theoretical methods for the chemical looping process. The oxygen carriers have been successfully prepared and the initial rate for the reduction reactions has been predicted as a function of initial molar concentration of Fe2TiO5, Fe2TiO4 and FeTiO3 at different temperatures from 800 to 1000 °C. Density functional theory calculations have been used to explain the reduction mechanism of oxygen carriers with H2. Our results show that the reduction of Fe2TiO5 with H2 has the smallest activation energy compared with the others. The observed rate constant values indicate that the reduction mechanism of Fe2TiO5 is much faster than that of the others. Also, we found that the diffusion of a H atom from Fe is the rate determining step for the reduction of the three iron titanium oxygen carriers. Additionally, the experimentally predicted activation energies are in good agreement with the theoretical values.

The characteristics and application of TiO2-supported Fe2O3 oxygen carriers were investigated for chemical looping combustion (CLC) and hydrogen generation (CLHG) in this study. Prepared Fe2O3/TiO2 oxygen carriers with 20–30 wt% of TiO2 were demonstrated to achieve satisfactory results even after 30-cycle operation by thermogravimetric analyzer (TGA). Oxygen carriers contain more than 33 wt% TiO2 were observed to be more porous and fragile after continuous high-temperature operation. Conversely, the reactivity of oxygen carriers contain less 10 wt% TiO2 was rapidly decayed after operated for merely 3 redox cycles because of their dense structure. The CO2 and H2 conversions through syngas combustion and steam oxidation, respectively, for experiments were demonstrated to be feasible using sieved oxygen carriers at higher operation temperatures from 400 to 1000°C in fixed bed reactor (FBR) system.

The bone marrow of healthy individuals is primarily composed of osteoblasts and hematopoietic cells, while that of osteoporosis patients has a larger portion of adipocytes. There is evidence that the epigenetic landscape can strongly influence cell differentiation. We have shown that it is possible to direct the trans-differentiation of adipocytes to osteoblasts by modifying the epigenetic landscape with a DNA methyltransferase inhibitor (DNMTi), 5'-aza-dC, followed by Wnt3a treatment to signal osteogenesis. Treating 3T3-L1 adipocytes with 5'-aza-dC induced demethylation in the hypermethylated CpG regions of bone marker genes; subsequent Wnt3a treatment drove the cells to osteogenic differentiation. When old mice with predominantly adipose marrow were treated with both 5'-aza-dC and Wnt3a, decreased fatty tissue and increased bone volume were observed. Together, our results indicate that epigenetic modification permits direct programming of adipocytes into osteoblasts in a mouse model of osteoporosis, suggesting that this approach could be useful in bone tissue-engineering applications.

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.

Cyclic amines such as 1,2,3,4-tetrahydroisoquinoline undergo regiodivergent annulation reactions with 4-nitrobutyraldehydes. These redox-neutral transformations enable the asymmetric synthesis of highly substituted polycyclic ring systems in just two steps from commercial materials. The utility of this process is illustrated in a rapid synthesis of (-)-protoemetinol. Computational studies provide mechanistic insights and implicate the elimination of acetic acid from an ammonium nitronate intermediate as the rate-determining step.

It was indicated that tetragonal zirconia polycrystal (TZP) containing yttria (Y2O3) and niobium oxide (Nb2O5) ((Y,Nb)-TZP) could be an adequate dental material to be used at esthetically important sites. The (Y,Nb)-TZP was also proved to possess its osteogenic potential comparable with those conventional dental implant material, titanium (Ti). The objective of the current study was to characterize cellular response of human gingival fibroblasts (HGFs) to smooth and rough surfaces of the (Y,Nb)-TZP disc, which were obtained by polishing and sandblasting, respectively. Various microscopic, biochemical, and molecular techniques were used to investigate the disc surfaces and cellular responses for the experimental (Y,Nb)-TZP and the comparing Ti groups. Sandblasted rough (Y,Nb)-TZP (Zir-R) discs had the highest surface roughness. HGFs cultured on polished (Y,Nb)-TZP (Zir) showed a rounded cell morphology and light spreading at 6 h after seeding and its proliferation rate significantly increased during seven days of culture compared to other surfaces. The mRNA expressions of type I collagen, integrin α2 and β1 were significantly stimulated for the Zir group at 24 h after seeding. The current findings, combined with the previous results, indicate that (Y,Nb)-TZP provides appropriate surface condition for osseointegration at the fixture level and for peri-implant mucosal sealing at the abutment level producing a suitable candidate for dental implantation with an expected favorable clinical outcome.

Purpose The aim of this study was to evaluate the capacity of single and combined applications of the bark of the stems and roots of Magnolia officinalis Rehd. et Wils. (Magnoliae Cortex) and Zea mays L. (maize) to modulate inflammation in RAW 264.7 cells stimulated with Porphyromonas gingivalis. Methods RAW 264.7 cells were stimulated with P. gingivalis, and Magnoliae Cortex and/or maize was added. Cytotoxicity and the capacity to modulate inflammation were determined with a methylthiazol tetrazolium (MTT) assay, nitrite production, enzyme-linked immunosorbent assay (ELISA), and western blotting. Results Treatment with Magnoliae Cortex and/or maize inhibited nuclear transcription factor κB (NF-κB) pathway activation and nuclear p44/42 mitogen-activated protein kinase (MAPK) and inducible nitric oxide synthase (iNOS) protein expression in P. gingivalis-stimulated RAW 264.7 cells. Moreover, the treatments suppressed cytokines (prostaglandin E2 [PGE2], interleukin [IL]-1β, and IL-6) and nitrite production. Conclusions Both Magnoliae Cortex and maize exerted an anti-inflammatory effect on P. gingivalis-stimulated RAW 264.7 cells, and this effect was more pronounced when the extracts were combined. These findings show that these extracts may be beneficial for slowing the progression of periodontal disease., Graphical Abstract

Chemical looping hydrogen generation (CLHG), as a new technology involved in chemical looping combustion (CLC) process and steam-iron process, has attracted attention for clean energy generation and efficient energy conversion. A systematic investigation of spinel NiFeAlO4 has led to characterization of a well-defined self-supported oxygen carrier which was prepared by solid state reaction. The redox behavior of NiFeAlO4 shows the enhancement on the resistance to agglomeration exceeding previously reported CLC process using similar compositions including Fe2O3, NiO and NiFe2O4 without any inert support. Moreover, the high CO2 conversion and H2 generation by NiFeAlO4 oxygen carrier under a fixed-bed reactor (FxBR) were obtained. The reaction mechanism of NiFeAlO4 subjected to the isothermal stepwise reduction in a sequence of varying durations by XRD was also demonstrated, which provided with a novel function of self-supported and agglomeration-resistant characteristic in the oxygen carrier system.

Rationale: The radiotherapy (RT) responses of gastroenteropancreatic (GEP)-origin neuroendocrine tumors remain unclear. We report cases of favorable response after localized RT of GEP-origin neuroendocrine carcinomas (GEP-NECs). Patient concerns: 1. An 82-year-old male presented with a lower esophageal mass. Positron emission tomography computed tomography (PET-CT) scan showed a lower esophageal mass and gastrohepatic lymph nodes. 2. A 52-year-old female presented with abdominal discomfort. CT scan showed a 9.8 cm-sized enhancing mass in the lesser sac abutting the stomach, pancreas and liver. 3. A 54-year-old male patient presented with anal pain and bleeding. CT scan showed a remnant mass in the perirectal area after trans-anal excision. Diagnoses: The diagnoses of GEP-NECs were pathologically confirmed by biopsy or excision, and immunohistochemical stainings of Ki-67, CD56, synaptophysin and chromogranin-A. Interventions: 1. The patient was treated with definitive RT. 2. The patient was treated with RT after two cycles of etoposide-cisplatin chemotherapy. 3. The patient was treated with adjuvant RT. Outcomes: 1. Complete remission was achieved based on CT scan four months after RT. 2. CT scan showed partial regression of the mass with a 5 cm-diameter at six months after RT. Adjuvant chemotherapy was administered after RT. 3. The residual mass was almost completely regressed at CT scan four months after RT. Lessons: In cases of GEP-NECs, RT can be a useful treatment modality with favorable tumor response for patients with inoperable conditions or those suffering from bulky tumor masses.

In this study, the bone regeneration efficacy of dehydrothermally (DHT) cross-linked collagen membrane with or without a bone graft (BG) material was evaluated in a critical-sized rat model. An 8-mm-diameter defect was created in the calvaria of 40 rats, which were randomized into four groups: (1) control; (2) DHT; (3) BG; and, (4) DHT + BG. Evaluations were made at 2 and 8 weeks after surgery using micro-computed tomographic (micro-CT), histological, and histomorphometric analyses. Micro-CT analysis showed an increase in the new bone volume (NBV) of the BG and DHT + BG groups at 2 weeks after surgery, representing a significant difference (p < 0.05). At 8 weeks after surgery, the NBV increased in all four groups. However, larger NBVs were observed in the BG and DHT + BG groups, and a significant difference was no longer observed between the two groups. Histologic analysis demonstrated that the graft materials sustained the center of the defect in the BG and DHT + BG groups, which was shown in histomorphometric analysis as well. These results suggest that DHT membrane is a safe biomaterial with adequate tissue integration, and has a positive effect on new bone formation. Moreover, the best effects were achieved when DHT was used in conjunction with BG materials.

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.

The initial stability of a dental implant is known to be an indicator of osseointegration at immediate loading upon insertion. Implant designs have a fundamental role in the initial stability. Although new designs with advanced surface technology have been suggested for the initial stability of implant systems, verification is not simple because of various assessment factors. Our study focused on comparing the initial stability between two different implant systems via design aspects. A simulated model corresponding to the first molar derived from the mandibular bone was constructed. Biomechanical characteristics between the two models were compared by finite element analysis (FEA). Mechanical testing was also performed to derive the maximum loads for the two implant systems. CMI IS-III active (IS-III) had a more desirable stress distribution than CMI IS-II active (IS-II) in the surrounding bone region. Moreover, IS-III decreased the stress transfer to the nerve under the axial loading direction more than IS-II. Changes of implant design did not affect the maximum load. Our analyses suggest that the optimized design (IS-III), which has a bigger bone volume without loss of initial fixation, may minimize the bone damage during fixture insertion and we expect greater effectiveness in older patients.