• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1396-1408
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• 2020

Filtered containment venting system (FCVS) is one of the severe accident mitigation systems designed to release containment pressurization to maintain its integrity. The thermal-hydraulic behaviors in FCVSs are important since they affect the operation characteristics of the FCVS. In this study, a representative FCVS was modeled by RELAP5/Mod3.3 code, and the Station BlackOut (SBO) was chosen as an accident scenario. The thermal-hydraulic behaviors of an FCVS during long-term operation with two venting strategies (open-and-close strategy, open-and-non-close strategy) and the sensitivity analysis of important parameters were investigated. The results show that the FCVS can operate up to 250 h with a periodic open-and-close strategy during an SBO. Under the combined effects of steam condensation and water evaporation, the solution inventory in the FCVS increases during the venting phase and decreases during the intermission phase, showing a periodic pattern. Under this condition, the appropriate initial water level is 3-4 m; however, it should be adjusted according to the environment temperature. The FCVS can accommodate a decay heat power of 150-260 kW and may need to feed water for a higher decay heat power or drain water for a lower decay heat power during the late phase. The FCVS can function within an opening pressure range from 450 kPa to 500 kPa and a closing pressure range between 250 kPa and 350 kPa. When the open-and-non-close strategy is adopted, the solution inventory increases quickly in the early venting phase due to steam condensation and then decreases gradually due to the evaporation of water; drying-up may occur in the late venting phase. Decreasing the venting pipe diameter and increasing the initial water level can mitigate the evaporation of the scrubbing solution. These results are expected to provide useful references for the design and engineering application of FCVSs.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.931-942
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• 2019

Radioactive materials are released from the molten core into the containment at the time of a severe accident in a nuclear power plant (NPP). Filtered containment venting system is a popular and effective safety measure installed to obstruct the uncontrolled escape of radioactive materials due to the over pressurization of the containment. Different designs of filtered containment venting system (FCVS) are available today, each being the result of extensive research and development varying in one way or the other. This paper gives an elaborate description of the different types of FCVS currently being used, the current usage status in over 17 countries and the legislations regarding it. The recent researches being carried out in this field has also been discussed in detail. This present paper focuses on the critical review of existing FCVS, reports the challenges faced by it and highlights the potential developments to overcome the difficulties.

• Annals of Clinical Neurophysiology
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• v.4 no.2
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• pp.108-113
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• 2002

Background and Objective : Carpal tunnel syndrome (CTS) is the most common mononeuropathy encountered in clinical practice. No single procedure or group of procedures has demonstrated adequate sensitivity. F-wave study in CTS is very rarely reported. To determine the diagnostic usefulness of new parameters of F-wave and comparative study of F-wave parameters of median and ulnar nerves in patients with CTS. Methods : F-wave responses of median and ulnar nerves were analyzed from 27 patients with clinically diagnosed CTS and 22 age and gender-matched normal control. Conventional F-wave parameters were studied. Also, the usefulness of new parameters such as mean and maximal ulnar-median F-wave latency differences, ulnar-median F-wave persistence and chronodispersion differences, median/ulnar F-wave amplitude ratio, and F-wave conduction velocity (FCV) using mean and maximal latency were assessed. Results : Compared with controls, median F-wave minimal, maximal and mean latencies, mean F-wave amplitude/M-wave amplitude, minimal, mean and maximal ulnar-median F-wave latency differences, and FCVs using minimal, maximal and mean latency were significant (P<0.05~0.001). Median F-wave minimal, maximal and mean latencies, mean ulnar-median F-wave latency difference, and FCVs using minimal, maximal and mean latency showed high sensitivity and specificity. Mean ulnar-median F-wave latency difference and FCVs using maximal and mean latency were new parameters. Conclusion : New F-wave parameter including mean ulnar- median F-wave latency difference and FCVs using maximal and mean latency may be a useful to assess the CTS. Also, median F-wave minimal, maximal and mean latencies, and FCV using minimal latency may be included in routine diagnostic tests in CTS.

• Korean Journal of Veterinary Research
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• v.62 no.3
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• pp.24.1-24.7
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• 2022

Incidences of major feline viral diseases provide basic information for preventing viral disease in cats. Despite the growing interest in feline viral diseases, sero-surveillances have been lacking. In this study, we analyzed the diagnoses of feline viral diseases and conducted a sero surveillance of feline panleukopenia virus (FPV), feline calicivirus (FCV), feline herpesvirus-1 (FHV-1), and feline infectious peritonitis virus (FIPV) in Korean cats. Of the 204 confirmed cases since 2015, the numbers of diagnoses for FPV, FIPV, FCV, feline influenza virus, and FHV-1 were 156, 32, 12, 3, and 1 case, respectively. In total, 200 sera, collected between 2019 and 2021, were screened for the presence of antibodies against FPV, 2 FCVs, FHV-1, and FIPV using a hemagglutination inhibition test and a virus-neutralizing assay (VNA). The overall seropositive rates in cats tested for FPV, the 2 FCVs, FHV-1, and FIPV were 92.5%. 42.0%, 37.0%, 52.0%, and 14.0%, respectively. A low correlation (r = 0.466) was detected between the VNA titers of 2 FCV strains. The highest incidence and seropositive rate of FPV reveal that FPV is circulating in Korean cats. The low r-value between 2 FCVs suggests that a new feline vaccine containing the 2 kinds of FCVs is required.

• Korean Journal of Veterinary Research
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• v.63 no.1
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• pp.5.1-5.9
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• 2023

Feline panleukopenia virus (FPV), feline calicivirus (FCV), and feline herpesvirus type-1 (FHV-1) are major infectious pathogens in cats. We evaluated the immunogenicity of a new vaccine containing inactivated FPV, two FCVs, and FHV-1 in animals. An FPV, two FCVs, and an FHV-1 isolate were continuously passaged 70, 50, 80, and 100 times in CRFK cells. FP70, FC50, FC80, and FH100 were propagated and used as vaccine antigens. Two inactivated feline virus vaccines, feline rehydragel-adjuvanted vaccine (FRAV) and feline cabopol-adjuvanted vaccine (FCAV) were prepared and inoculated into mice and guinea pigs. Humoral immune responses were measured using hemagglutination inhibition (HI) for FPV and virus-neutralizing antibody (VNA) for two FCVs and FHV-1 tests. Serial passages in CRFK cells resulted in increase in titers of FPV and two FCVs but not FHV-1 The FCAV induced higher mean HI and VNA titers than the FRAV in guinea pigs; therefore, the FCAV was selected. Cats inoculated with FCAV developed a mean HI titer of 259.9 against FPV, and VNA titers of 64, 256, and 3.2 against FCV17D03, FCV17D283, and FHV191071, respectively. Therefore, cats inoculated with the FCAV showed a considerable immune response after receiving a booster vaccination.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.3
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• pp.189-197
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• 2016

Green vehicles include electric vehicles, natural gas vehicles, and fuel cell vehicles (FCVs). In FCVs, pressure vessels have cylinder valves to control hydrogen flow. These valves should be of high quality in terms of safety because hydrogen is stored at ultra-high pressure in pressure vessels. Hence, safety evaluation of these valves is necessary to secure the safety of the FCV. A structural analysis of the cylinder valve was conducted in this study by using a commercial finite element analysis code. The results showed that the safety factor of valve component ranged 1.06-186.44. After categorizing, the stress components at critical points of the cylinder valve parts were evaluated using the corresponding allowable design criteria in the ASME code. The pressurization cycle test was performed as per the regulation to evaluate the safety of the valve.

• Korean Journal of Veterinary Research
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• v.60 no.4
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• pp.195-202
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• 2020

Feline calicivirus (FCV) infection results in a common upper respiratory disease associated with oral ulceration in cats. Although FCV infection has been reported in cats worldwide, the biologic and genetic features of South Korean FCV are unclear. We aimed to investigate the biological and genetic features of South Korean FCV isolates. Crandell-Rees feline kidney (CRFK) cells were used to isolate FCV from 58 organ homogenate samples. The FCV isolates were confirmed by cytopathic effects, immunofluorescence, electron microscopy, and reverse transcription polymerase chain reaction assays. Viral genetic analysis was carried out with VP2 gene and complete genomes of FCVs. Five viruses propagated in CRFK cells were confirmed to be FCVs. The FCV17D283 isolate showed the highest viral titer of 107.2 TCID50/mL at 36 h post-inoculation. Korean FCV isolates did not grow well in Vero, BHK-21, A72, or Madin-Darby canine kidney cells. The FCV17D03 and FCV17D283 isolates had the highest genetic similarity (80.1% and 86.9%) with the UTCVM-H1 and 14Q315 strains, which were isolated in the United States and South Korea in 1995 and 2014, respectively. We isolated five FCVs from cats and detected important genetic differences among them. FCV isolates did not show any virulent effects in mice.

• Journal of the Korean Dietetic Association
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• v.26 no.2
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• pp.116-125
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• 2020

The purpose of this study was to assess the sugars contents of home meal replacement (HMR) products currently sold in Korea. This study surveyed and examined the sugars contents in 835 popular HMRs (294 ready-to-eat foods; RTE, 499 ready-to-cook foods; RTC, 42 fresh-cut vegetables; FCV) through the nutrition labels. The average price, weight and energy content of 835 HMR products were 3,917.5 Korean won, 336.0 g, and 522.7 kcal, respectively. The sugars content per product was significantly higher in the RTCs (13.4 g) and RTEs (10.3 g) than that in the FCVs (4.2 g) (P<0.001), and the percentage of energy from sugars was 9.7% for the RTEs, 10.2% for the RTCs, and 8.7% for the FCVs without any significant difference. The sugars contents of 9 RTE types were in the order of side dishes (34.3 g), sunsik (22.5 g) and hamburgers (12.1 g) per package. The percentage of energy from sugars was highest in side dishes (28.1%), followed by kimchi (24.9%), sunsik (17.2%), and hamburgers (10.6%). Among 14 RTC types, the sugars contents were in the order of hot dogs (52.9 g), tteokbokki (30.4 g) and noodles (21.2 g) per package. The percentage of energy from sugars was the highest at 22.9% for sauces, followed by side dishes (17.3%), porridges (14.4%), instant stews (14.3%), and hot dogs (13.1%). Strategies and practices are needed to reduce the sugars contents of HMR producers and the sugars intakes of HMR consumers.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3310-3316
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• 2022

Owing to the rising concerns about the safety of nuclear power plants (NPP), it is essential to study the venturi scrubber in detail, which is a key component of the filtered containment venting system (FCVS). FCVS alleviates the pressurein containment byfiltering and venting out the contaminated air. Themain objective of this research was to perform a CFD investigation of different configurations of a circular, non-submerged, self-priming venturi scrubber to estimate and improve the performance in the removal of elemental iodine from the air. For benchmarking, a mass transfer model which is based on two-film theory was selected and validated by experimental data where an alkaline solution was considered as the scrubbing solution. This mass transfer model was modified and implemented on a unique formation of two self-priming venturi scrubbers in series. Euler-Euler method was used for two-phase modeling and the realizable K-ε model was used for capturing the turbulence. The obtained results showed a remarkable improvement in the removal of radioactive iodine from the air using a series combination of venturi scrubbers. The removal efficiency was improved at every single data point.

• Journal of Electrochemical Science and Technology
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• v.15 no.1
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• pp.96-110
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• 2024

Polymer electrolyte membrane fuel cells (PEMFCs) are green energy conversion devices, for which commercial markets have been established, owing to their application in fuel cell vehicles (FCVs). Development of cathode electrocatalysts, replacing commercial Pt/C, plays a crucial role in factors such as cost reduction, high performance, and durability in FCVs. PtNi octahedral catalysts are promising for oxygen reduction reactions owing to their significantly higher mass activity (10-15 times) than that of Pt/C; however, their application in membrane electrode assemblies (MEAs) is challenged by their low stability. To overcome this durability issue, various approaches, such as third-metal doping, composition control, halide treatment, formation of a Pt layer, annealing treatment, and size control, have been explored and have shown promising improvements in stability in rotating disk electrode (RDE) testing. In this review, we aimed to compare the features of each strategy in terms of enhancing stability by introducing a stability improvement factor for a direct and reasonable comparison. The limitations of each strategy for enhancing stability of PtNi octahedral are also described. This review can serve as a valuable guide for the development of strategies to enhance the durability of octahedral PtNi.