• Nuclear Engineering and Technology
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• 제39권5호
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• pp.603-616
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• 2007

Roy Huddle, having invented the coated particle in Harwell 1957, stated in the early 1970s that we know now everything about particles and coatings and should be going over to deal with other problems. This was on the occasion of the Dragon fuel performance information meeting London 1973: How wrong a genius be! It took until 1978 that really good particles were made in Germany, then during the Japanese HTTR production in the 1990s and finally the Chinese 2000-2001 campaign for HTR-10. Here, we present a review of history and present status. Today, good fuel is measured by different standards from the seventies: where $9*10^{-4}$ initial free heavy metal fraction was typical for early AVR carbide fuel and $3*10^{-4}$ initial free heavy metal fraction was acceptable for oxide fuel in THTR, we insist on values more than an order of magnitude below this value today. Half a percent of particle failure at the end-of-irradiation, another ancient standard, is not even acceptable today, even for the most severe accidents. While legislation and licensing has not changed, one of the reasons we insist on these improvements is the preference for passive systems rather than active controls of earlier times. After renewed HTGR interest, we are reporting about the start of new or reactivated coated particle work in several parts of the world, considering the aspects of designs/ traditional and new materials, manufacturing technologies/ quality control quality assurance, irradiation and accident performance, modeling and performance predictions, and fuel cycle aspects and spent fuel treatment. In very general terms, the coated particle should be strong, reliable, retentive, and affordable. These properties have to be quantified and will be eventually optimized for a specific application system. Results obtained so far indicate that the same particle can be used for steam cycle applications with $700-750^{\circ}C$ helium coolant gas exit, for gas turbine applications at $850-900^{\circ}C$ and for process heat/hydrogen generation applications with $950^{\circ}C$ outlet temperatures. There is a clear set of standards for modem high quality fuel in terms of low levels of heavy metal contamination, manufacture-induced particle defects during fuel body and fuel element making, irradiation/accident induced particle failures and limits on fission product release from intact particles. While gas-cooled reactor design is still open-ended with blocks for the prismatic and spherical fuel elements for the pebble-bed design, there is near worldwide agreement on high quality fuel: a $500{\mu}m$ diameter $UO_2$ kernel of 10% enrichment is surrounded by a $100{\mu}m$ thick sacrificial buffer layer to be followed by a dense inner pyrocarbon layer, a high quality silicon carbide layer of $35{\mu}m$ thickness and theoretical density and another outer pyrocarbon layer. Good performance has been demonstrated both under operational and under accident conditions, i.e. to 10% FIMA and maximum $1600^{\circ}C$ afterwards. And it is the wide-ranging demonstration experience that makes this particle superior. Recommendations are made for further work: 1. Generation of data for presently manufactured materials, e.g. SiC strength and strength distribution, PyC creep and shrinkage and many more material data sets. 2. Renewed start of irradiation and accident testing of modem coated particle fuel. 3. Analysis of existing and newly created data with a view to demonstrate satisfactory performance at burnups beyond 10% FIMA and complete fission product retention even in accidents that go beyond $1600^{\circ}C$ for a short period of time. This work should proceed at both national and international level.

• Journal of Bio-Environment Control
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• 제19권1호
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• pp.49-54
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• 2010

The study was conducted to compare the postharvest physiology and storability of fresh cut paprika fruits classified by normal, blossom end rot(BER), and misshapen (or knots) fruit. Some disordered paprika fruits that were produced frequently during high temperature season in highland, were sorted out to non-marketable products. These fruits are mostly wasted, but some of them may be used for fresh cut. The respiration rate of fresh cut paprika fruits was lower and ethylene production rate was higher in normal fruits than in disordered fruits, but there was no significant difference. The fresh-cut paprika fruits were stored in MAP conditions at $4^{\circ}C$, $9^{\circ}C$ and room temperature in 25 ${\mu}m$ and 50 ${\mu}m$ thickness ceramic film packaging. The fresh weight of fresh cut paprika fruits decreased below to 1.1% regardless of fruit types, but the fresh weight loss increased in thinner packaging materials and lower storage temperatures. There were not significant different carbon dioxide and oxygen contents in MAP of all fruit types, while $4^{\circ}C$ storage temperature treatment and 25 ${\mu}m$ thickness ceramic film treatment had lower carbon dioxide and higher oxygen contents. Moreover, the carbon dioxide and oxygen contents were changed rapidly at 9 days in $4^{\circ}C$ storage and at 6 days in $9^{\circ}C$ storage when the visual quality of fresh cut decreased dramatically. The ethylene concentration of packages was below 7 ${\mu}l{\cdot}l^{-1}$ in all treatments during storage, while the treatments of thinner packaging material and lower storage temperature showed lower ethylene concentration. The fresh cut of disordered fruits showed less visual quality than normal fruit treatment in both $4^{\circ}C$ and $9^{\circ}C$ storage temperatures, but there was no significant difference. The value of $4^{\circ}C$ treatment that measured 12 days in storage was higher than $9^{\circ}C$ treatment that measured 9 days in storage. The results suggest that the disordered fruits may be used to fresh cut product without any concerns that they will decreased the value of commodities more quickly than the fresh cut made of marketable paprika fruits. As the fresh cut paprika fruits stored in MAP condition, the more effective storage temperature is $4^{\circ}C$ that may have induced chilling injury a whole fruit of the paprika.

• Korean journal of food and cookery science
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• 제21권6호통권90호
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• pp.895-907
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• 2005

In an attempt to improve the taste and storage characteristics of Sulgidduk, a Korean traditional rice cake product, baekbokryung(White Poria cocos Wolf) powder was supplemented as one of the ingredients and Product Quality waw assessed. The baekbokryung Powder was added in rations of 0, 5, 7, 10, and $15\%$(w/w) per rice powder during the raw material preparations. The sensory, objective quality, and microbiological characteristics of the products were examined at 4-hr intervals during storage for 36 hours at $20^{\circ}C$ The sensory evaluation was conducted based on the acceptability and intensity characteristics of the product. In the acceptability test, a $5\%$ treatment wae renerally ranked with the highest score, among all the treatments while the preference differed according to ages of the panels ; namely, those in their 20's to 30's liked a $5\%$ supplementation while those in their 40's to 60's Preferred a $7\%$ one. The addition of baekbokryung Powder proportionally decreased the moisture content of the products. The colorimetric redness(a) and yellowness(b) of the Products increased with increasing added baekbokryung Powder. The redness values began to decrease slowly from the beginning while the rates were accelerated after 8 to 12 hours of the storage. In the textural characteristics, hardness, gumminess and adhesiveness values increased with increasing added baekbokryung powder. The rapid increase in adhesiveness during the initial 4 hour of storage and the following stabilization was noted. Cohesiveness and springiness values tended to decrease gradually with increasing added baekbokryung Powder. Except for the control sample, no significant differences in the total microbial counts among the treatments were noted. After 20 hours of storage, the control sample exhibited a rapid increase in total microbial count, while the Proliferations of microorganisms were rather suppressed in baekbokryung Powder treatments according to the added amounts The results of the study support the benefits of baekbokryung powder supplementation in Sulgidduk in the aspects of taste and functionality. The degree of further increase of baekbokryung Powder in Sulgidduk without causing the adverse qualify effects remains for future study.

• Applied Biological Chemistry
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• 제50권4호
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• pp.287-294
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• 2007

Effect of combined use of anti-microbial materials, such as ethanol, mustard and chitosan, on the quality of low salted kochujang was investigated during fermentation at $20^{\circ}C$ for 12 weeks. Viable cells of yeast increased remarkably during fermentation, but increasing ratio was significantly low in ethanol-mustard added kochujang. Activity of ${\beta}-amylase$ was high in anti-microbial material added kochujang, whereas ${\alpha}-amylase$ and protease activities were low in those groups. Water activity decreased during fermentation with being low in the control kochujang prepared with normal-salt without anti-microbial materials. Hunter L-, a- and b-values of kochujang increased during fermentation, and the degree of increase in total color difference $({\Delta}E)$ was low in ethanol added kochujang. Titratable acidity of kochujang was decreased in anti-microbial materials added group at late aging period, and oxidation-reduction potential was low in the control kochujang. Total sugar and reducing sugar contents of kochujang were high in ethanol-mustard added kochujang. Ethanol contents of kochujang increased at late aging period, with high values in ethanol-chitosan added kochujang. Amino nitrogen content increased during middle of fermentation, and ammonia nitrogen content of kochujang decreased in ethanol-mustard-chitosan added group during fermentation. After 12 weeks fermentation, sensory results showed that ethanol or ethanol-mustard added kochujang were the highest in color and flavor with the highest overall acceptability.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• 제8권1호
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• pp.205-222
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• 2013

As Social Welfare Service Act was revised in 2011 and its enforcement decree was revised in 2012, the function of local social welfare center was classified into 3 functions such as case control function, service supply function and local society systematization function. Therefore, from 2013, local social welfare center faces the assignment to establish its status as a core subjectivity of local social welfare while maintaining function, role, business, program, service and organization system required for local social welfare center. Currently, there are internal and external limit factors for local social welfare center to perform its original function. The external limit factors are competition with similar organization, diversification of welfare desire depending on social change, insufficient service network construction and lack of partnership between private sector and government. The internal limit factors are lack of local social organization's ability, program issue, insufficient resource, insufficient manpower, etc. In order for local social welfare center to overcome the limit factor and establish the core status for improving the life quality of resident, it should concentrate its ability on local society systematization, construct human & material support network related to local social welfare, minimize social education program and simple relief project gradually, suggest the reasonable direction for village to nurture resident organization, develop the program based on the research on local resident's desire and create the partnership between private sector and government.

• Food Science and Preservation
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• 제19권1호
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• pp.144-152
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• 2012

The temperature changes and quality characteristics of $Makgeolli$ produced using rice treated with $Gaeryang-Nuruk$ (commercial improved $Nuruk$) extract were investigated. During fermentation, the treated rice maintained a lower temperature than the control and then rose after the fifth mashing day. For all the treatments, the numbers of yeast, LAB and AAB colonies increased on the second mashing day, and then gradually decreased. As the fermentation proceeded, the pH gradually increased from the third mashing day, and eventually became higher than that on the initial mashing day. The total acid contents increased on the first mashing day, but as the fermentation progressed, they showed little change. The amino acidity and soluble solid contents during overall fermentation and reducing-sugar contents was reduced until the first mashing day, and increased from the day after. As for the alcohol content, that of the control was 6.87% on the first mashing day, and then gradually increased, nuruk-extract-treated rice began with 9~10% alcohol content and then increased as the fermentation proceeded. Among the organic acid contents, lactate was the main material. In the sensory evaluation, the 24 h-, 48 h- and 72 h- treated rice samples showed somewhat good response.

• Journal of Life Science
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• 제22권5호
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• pp.650-656
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• 2012

To reduce the production cost of $Pleurotus$ $ostreatus$, discarded medicinal sludge was collected from oriental medical clinics to develop the $Pleurotus$ $ostreatus$ culture medium. According to the analysis of the proximate composition of the materials used in Korean herb medicine, the crude ash contents of $Carthamus$ $tinctrius$ L stem and $Acanthopanax$ $chiisanensis$ were 11.6% and 10.1% respectively, which were relatively higher than the 9.6% of the control medium, waste cotton. Crude protein was detected in 9.8% of the waste cotton medium, whereas it was detected in 14.9%, 13.9%, 13.4%, and 11.5%, of wild mugwort, $Acanthopanax$ $\underline{chiisanensis}$, medicinal sludge, and $Carthamus$ $tinctrius$ L stem, respectively, which are all higher than the control. The pH of medicinal sludges, wild mugwort, and $Aacanthopanax$ $chiisanenses$ ranged from 5.27 to 5.72, which was similar to the 5.70 pH value of waste cotton. In the case of addition concentration of each Korean herb medicine material influencing mycelial growth of the $Pleurotus$ $ostreatus$, the 9% concentration was more favorable compared to that of 3% and 6%. However, the addition of Korean herb medicine materials did not significantly affect the growth of $P.$ $tolaassi$ and $Trichoderma$ $sp.$ According to a field experiment that added 9% of medicinal sludge into the waste cotton medium, the mycelial growth of mushrooms was facilitated by approximately 2 days, and the mushroom yield was increased by 10~15%. Furthermore, pileus and stipe of the mushrooms were even and superior in quality.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 한국항해항만학회 2002년도 추계공동학술대회논문집
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• pp.147-153
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• 2002

Due to the growth of population and industrial development at the coastal cities, there has been much increase in necessity to effective control of the wastes into the coastal water and river. The amount of disposal at those waters has been increased rapidly and it is necessary for us to track of it in order to keep the water clean. The investigation and research related to the water quality in this region have been conducted continuously but the systematic survey of the disposed wastes at the bottom was neglected and/or minor. In this study we surveyed the status of disposed waste distribution at the bottom coastal water and river from the scanned images. The intensity of sound received by the side scan sonar tow vehicle from the sea floor provides information as to the general distribution and characteristics of the superficial wastes. The port and starboard side scanned images produced from a transducer borne on a tow fish connected by tow cable to a tug boat have the area with width of 22m∼112m, and band of 44m∼224m. All data are displayed in real-time on a high-resolution color display (1280 ${\times}$ 1024 pixels) together with position information by DGPS. From the field measurement and analysis of the recorded images, we could draw the location and distribution of bottom disposals. Furthermore, we made a database system which might be fundamental for planning the waste reception and process control system.

• Journal of Korean Society of Environmental Engineers
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• 제36권11호
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• pp.781-790
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• 2014

Contaminants such as organic matters, nutrients and toxic chemicals in rivers and lakes with a weak flow rate are first removed from the water and accumulated in the sediments. Subsequently, they are released into the water column again, posing direct/indirect adverse effects on the water quality and aquatic ecosystems. In particular, phosphorus is known to accelerate the eutrophication phenomenon when it is released into the water column via physical disturbance and biological/chemical actions as one of important materials that determine the primary production of aquatic ecosystems and an element that is stored mainly in the sediments in the process of material circulation in the body of water. In this study, the effect on reducing phosphorus release in sediments was analyzed by applying different capping materials to lake water, where the effect of aquatic microorganisms is taken into account, and to distilled water, where the effect of microorganisms is excluded. The experimental results showed that capping with chemical materials such as Fe-gypsum and $SiO_2$-gypsum further reduced the phosphorus release by at least 40% compared to the control case. Composite materials like granule gypsum+Sand showed over 50% phosphorus release reduction effect. Therefore, it is determined that capping with chemical materials such as granule-gypsum and eco-friendly materials such as sand is effective in reducing phosphorus release. The changes in phosphorus properties in the sediments before and after capping treatment showed that gypsum input helped to change the phosphorus that is present in lake sediments into apatite-P, a stable form that makes phosphorus release difficult. Based on the above results, it is expected that the application of capping technology will contribute to improving the efficiency of reducing phosphorus release that occurs in river and lake sediments.

• Korean Journal of Environmental Agriculture
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• 제39권3호
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• pp.222-227
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• 2020

BACKGROUND: Among the biomass conversion techniques of livestock manure, composting process is a method of decomposing organic matter through microorganisms, and converting it into fertilizer in soil. The aerobic composting process is capable of treating cow manure in large quantities, and produces greenhouse gas as CO₂ and N₂O, although it has economical benefit. By using the activated rice hull biochar, which is a porous material, it was intended to mitigate the greenhouse gas emissions, and to produce the compost of which quality was high. Objective of this experiment was to estimate CO₂ and N₂O emissions through composting process of cow manure with different cooperated biochar contents. METHODS AND RESULTS: The treatments of activated rice hull biochar were set at 0%, 5%, 10% and 15%, respectively, during composting cow manure. The CO₂ emission in the control was 534.7 L kg^-1, but was 385.5 L kg^-1 at 15% activated rice hull biochar. Reduction efficiency of CO₂ emission was estimated to be 28%. N₂O emission was 0.28 L kg^-1 in the control, but was 0.03 L min^-1 at 15% of activated rice hull biochar, estimating about 89% reduction efficiency. CONCLUSION: Greenhouse gas emissions during the composting process of cow manure can be reduced by mixing with 15% of activated rice hull biochar for eco-friendly compost production.