• Nuclear Engineering and Technology
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• v.22 no.4
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• pp.337-350
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• 1990

A post-irradiation annealing study was conducted with use of reactor pressure vessel(RPV) steel A533B Cl.1 base metal irradiated to a dose of 4.84$\times$10$^{18}$ n/$\textrm{cm}^2$ at about 38$0^{\circ}C$. Microhardness and positron annihilation (PA) methods were used to obtain better understanding of the recovery of radiation hardening. Isochronal anneal experiments indicated that two recovery processes occur during annealing of irradiated specimens. The first recovery process occurs in the temperature range of 280-3O5$^{\circ}C$, Michrohardness and positron annihilation (PA) methods were used to obtain better understanding of the recovery of radiation hardening. Isochronal anneal experiments indicated that two recovery processes occur during annealing of irradiated specimens. The first recovery process occurrs in the temperature range of 280-305$^{\circ}C$. The variations of Ip, Iw and R parameters indicated that the formation of vacancy clusters by vacancy agglomeration and the annihilation of monovacancies are the first recovery process. The second recovery process occurs in the range of 405-49$0^{\circ}C$ and positron annihilation parameters measured indicated that the dissolution of carbon atoms decorated around vacancy-type defects and possible precipitates, and the annihilation of monovacancies give rise to the second recovery process. It was further indicated that radiation anneal hardening (RAH) in the range of 305-405$^{\circ}C$ between the temperature ranges for the two processes occurs due to the formation of carbon-decorated vacancy clusters and precipitates. The activation energies, orders of reaction and other characteristics of recovery processes were determined by the Meechan-Brinkman method. The activation energy for the first recovery process was determined as 1.76 eV and that for the second recovery process as 2.00eV. These values are lower than those obtained by other workers. This difference may be attributed to the lower copper content of the RPV steel used in the present study. The order of reaction for the first recovery process was determined as 1.78, while that for the second recovery process as 1.67 Non-integer orders of reaction for recovery processes seem to be attributed to the fact that several mechanisms for the first order and the second order of reaction are compounded in one process. This result also supports for the above conclusions from measurements of PA parameters.

• Food Science and Preservation
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• v.13 no.6
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• pp.754-761
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• 2006

This study was to investigate the effect of chitosan-ascorbate (CA) prepared with different molecular weight (223, 746, 1110 and 2025 kDa) on the fermentation and quality of mul-kimchi, and also, the effect of the mul-kimchi juice fermented with 0.1% chitosan-ascorbate prepared with 2025 kDa chitosan (CA2025) on the serum lipids of rae fed with high cholesterol diet (HC). The mul-kimchi fermented in 0.1% CA2025 has lower turbidity, longer shelf-life, higher glucosamine content and SOD activity than those of control and the other treatments. In the animal experiment the HC-CA2025 and HC-2CA2025 groups which were administered 0.5 mL per 100 g body weight of mul-kimchi juice fermented with 0.1% CA2025 and administered the same volume of the juice concentrated 112 per nay fed for 5 week, respectively. The average body weight of the HC-CA2025 and HC-2CA2025 group was lower 6.9% and 8.4% than that of HC control group respectively. Total serum cholesterol contents of these groups were 88.33 and 85.00 mg/uL, which were 17.45% and 20.56% lower than HC control group respectively. While, HDL-cholesterol content of these groups were 7% and 23%, higher the LDL-cholesterol content were 13% and 26% lower than those of HC control group respectively. And also, though the atherogenic index, AST and ALT activities were not reached to normal control group, the values were remarkably lower than those of HC control group. This study indicates the possibility of utility for kimchi industry by adding chitosan-ascorbate, especially CA2025 showing not only quality enhancing and shelf-life prolongation but also improving serum lipids and atherogenic index in rats fed with high cholesterol diet.

• Food Science and Preservation
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• v.21 no.1
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• pp.62-68
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• 2014

This study was performed in order to investigate the functional components of 5 kinds of marine algae. We have collected 5 samples of marine algae, such as the sea mustard (Undaria pinnatifida), sea tangle (Laminaria iaponice), sea weed fusiforme (Hizikia fusiforme), green laver (Entetomotpha), laver (Phophyratenera), which have been harvested in Jeollanam-do. In order to examine the functional effects, 5 kinds of marine algae were extracted with hot water ($80^{\circ}C$, 4 hr), ethanol and methanol (R.T., 4 hr), and subcritical water extract (SWE, 3 MPa, $90^{\circ}C$, $150^{\circ}C$, $210^{\circ}C$). A higher yield of extract was obtained through SWE method (3 MPa, $210^{\circ}C$) in all of the samples obtained. The highest total sugar content was 427.4 mg/g in green laver extracted with SWE (3 MPa, $210^{\circ}C$). The content of the SWE total phenolic compounds was higher than that of the water and solvent (methanol, ethanol) extracts. The anti-oxidative activities of the extracts from 5 kinds of marine algae were examined through the DPPH radical scavenging activity test. The SWE (3 MPa, $150^{\circ}C$ and $210^{\circ}C$) of the marine algae was the highest among all of the extracts. As per the results, the SWE of the marine algae contained more functional components and it had a higher antioxidant activity than those of the other extracts. The $IC_{50}$ value of tyrosinase in seaweed fusiforme and laver were higher than those of the other samples. These results strongly support the possible use of marine algae as functional materials.

• Food Science and Preservation
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• v.20 no.5
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• pp.602-607
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• 2013

Correct packaging enables processors to pack fresh produce and extend its shelf life. This study was carried out to investigate the effect of different packaging materials on the weight loss, pH, $O_2$, $CO_2$ and sensory characteristics of soybean sprouts during their storage at $5^{\circ}C$ for seven days. Soybean sprouts ($320{\pm}20g$) were packaged with oriented polypropylene (OPP) and cast polypropylene (CPP) films, respectively. The $O_2$ transmission rate of the packaging materials was set to have a control of $10,000cc/m^2$.day.atm, and an OP15 and CP15 with $15,000cc/m^2$.day.atm through a pre-screening test. The average weight loss of the soybean sprouts during their storage was less than 10%, and that of the soybean sprouts with a CPP film was higher than that of the OPP film. The pH of the soybean sprouts increased during their storage regardless of their packaging materials; but compared to the pH of the soybean sprouts packaged with OPP, those packaged with CPP were higher. The $CO_2$ content of the packaging increased with a decrease in the $O_2$ content. The ratio of $CO_2$ to $O_2$ in the soybean sprouts with the OPP film was 3.5 times higher than in the soybean sprouts with the CPP film. The results of the overall sensory test showed that the marketability of the soybean sprouts packaged with OPP film and stored at $5^{\circ}C$ seemed to have been maintained effectively for six days (at a $15,000cc/m^2$.day.atm $O_2$ transmission rate). When the correlation coefficients of the control, OP15 and CP15 were analyzed, the highest correlation was shown between a control and OP15 (0.986; p<0.01).

• Food Science and Preservation
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• v.24 no.7
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• pp.908-914
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• 2017

Cold plasma (CP) was applied to examine microbial safety and physicochemical properties of rough rice. CP was generated in a square-shaped plastic container (250 W, 15 kHz, ambient air) and dielectric barrier discharge plasma treatment was applied for periods of 0, 10, and 20 min during 2 weeks at 4 and $25^{\circ}C$. As a result of observing changes in growth of microorganisms, 3.46-3.86 log CFU/g of total aerobic bacteria and 2.27-2.86 log CFU/g of mold were detected in the early stage of storage. The growth of total aerobic bacteria and mold was increased depending on the storage temperature and period, but there was no big difference between cultivars. Microbial analysis after storage showed that microorganisms of plasma-treated group were less grown approximately 1.50 log CFU/g. Moisture content of rough rice was decreased by storage temperature and periods. As for the amylose content, changes in the content by plasma were not observed in Samkwang, Cheongpum and Misomi, whereas Palbangmi showed a tendency to increase. The results of this study indicated that CP treatment improved the microbial quality of rough rice, but further studies should be conducted to reduce the deterioration of sensory quality induced by CP.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.449-460
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• 2013

This study analyzes the processes of change in oral health behaviors induced by oral health education for 23 university students. To this end, we analyzed the changing patterns of the stages of change and motivational components for each oral health behavior. Additionally, we performed an in-depth interview-based investigation of the factors influencing such motivational components. Oral health education was performed twice with a concrete purpose of changing the participants' behaviors in complying with the practice of proper brushing and flossing as the main oral health management, and checking the nutrient facts as a good dietary habit. Upon completion of these two sessions of oral health education, the level of change in oral health behavior was assessed by measuring the stages of change and motivational components for each oral health behavior. In order to gain an in-depth understanding of the reasons for the changes that were demonstrated more markedly during the second education session than during the first session, collective interview surveys were carried out after the second session. The contents of the recorded interviews were categorized into subscales of distinctive concepts on the basis of the items of a health behavior model. The study had the findings as below. First, after the first and second education sessions, some behaviors showed positive changes from lower to higher levels of practice. Second, self-efficacy about oral health behavior was high or perceived barriers were low when its necessity and benefits were clearly perceived. Third, educational features such as the practice and participation-centered education, and examining their own oral conditions influenced the participants' oral health awareness and behavioral changes. There is a need for oral health education capable of leading to practical behavioral changes by establishing concrete strategies of deriving various motivational components at each stage of the processes of change.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.6
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• pp.997-1006
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• 2008

Four different spices (herbs) including rosemary, oregano, basil & sage and green tea were added individually to the ground pork or ground chicken with different percentages of 0.5, 1.0, and 1.5, respectively. The consumer sensory qualities of the five natural herbs and their antioxidant effects were evaluated using pork- and chicken-Yukwonjeon. In our consumer sensory evaluation, the 0.5% herb addition and control groups had generally better acceptability than the higher addition groups. In particular, pork-Yukwonjeon with the addition of 0.5% of green tea or oregano and chicken-Yukwonjeon with the addition of 0.5% of green tea or rosemary 0.5% were generally preferred more profoundly on the acceptance and ranking tests. However, sensory differences, especially in texture, among the different samples were reduced after storage. With regard to the results of lipid oxidation without storage, the TBARS values of the herb addition groups were slightly lower than those of the control group, but not significantly so (p>0.05). The antioxidant effects of each herb achieved higher values at longer storage times and with higher levels of added herbs. The antioxidant effects differed with different kinds of meat. The addition of the herb samples resulted in TBARS value reductions of $15.0{\sim}45.8%$ and $9.5{\sim}31.0%$, respectively, in the pork and chicken-Yukwonjeon stored at $6^{\circ}C$. Furthermore, the antioxidant effects of herbs during storage at $-20^{\circ}C$ were observed as reducing in the TBARS values of $8.4{\sim}31.7%$ and $19.0{\sim}33.0%$ in the pork-and chicken-Yukwonjeon, respectively. Green tea evidenced the highest levels of antioxidant activity on lipid oxidation, as it was acceptable even at higher concentrations according to our sensory evaluations. These results illustrate the possibility of producing superior Yukwongen with green tea and herbs, according to the different kinds of meat used.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.253-262
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• 2013

This experiment was conducted to investigate the effects of floor type and heating system on performance, housing environment and health status of ducks reared in three types of duck house (OD : Open floor house-Direct heating system, OF : Open floor house-Floor heating system and LD : Loft type house-Direct heating system). In OF treatment, PVC pipes were installed for heating under concrete floor and covered with litter. In LD treatment, plastic mesh was installed 50 cm above the floor so that duck's droppings can pass through it. Each treatment had four replicates of 25 birds (Cherry Valley duck breed) per pen. There were no significant differences in weight gain and feed intake of ducks for 6 weeks among all treatments. However, feed conversion ratio in LD was significantly higher (p<0.05) than that in OF. No differences were found in carcass charac- teristics, with the exception of abdominal fat weight where OF were higher than the others. Concentrations of $CO_2$ and $NH_3$ gas in OD were higher than those of OF and LD at 3, 4 and 5 weeks. Moisture content in litter of OF was lower than that of OD. In contrast, the amount of dust in the air was higher in OF than in OD. The amount of fuel used for 6 weeks in LD was lower about 21% than that in OD. Some of unusual symptoms were observed in open floor house and loft type house, such as lying, spraddle legged, twisted ankle and legs, wounded sole, or etc. No components of leukocyte and erythrocyte of blood were significantly different among all treatments. The results of this experiment showed that OF and LD systems had no positive effects on performance of meat type commercial duck. However, there were some positive effects of certain house type for the improvement of environmental condition in duck house for hygienic production. In the future, more research on the effect of various facilities and systems for duck house is needed.

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.273-279
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• 2016

Recently, it was reported that certain polymorphisms in the growth hormone secretagogue receptor gene (GHSR) are associated with the growth of chickens. However, the correlation between GHSR polymorphisms and economic traits has not been investigated in Korean native chickens (KNCs). Therefore, the objective of this study was to confirm the suitability of the GHSR gene as a candidate for genomic selection and identify a genetic marker for KNCs. A total of 220 KNCs from six breeds raised at the National Institute of Animal Science were genotyped for the c.739+726 SNP in the GHSR gene using polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP), and the sequence for a subset of 30 birds was analyzed using direct sequencing. The association between the SNP genotypes and the economic traits of the KNCs was analyzed using the statistical package for the social science (SPSS) software program. The association analysis between the c.739+726T>C SNP and economic traits revealed that the SNP was significantly associated with body weight at 150 and 270 days (BW150 and BW270, respectively) in all KNCs (p<0.01), BW150 in KNC (Gary) (p<0.05), and egg production number in KNC (White, p<0.05). In addition, the SNPs discovered using direct sequencing (513A>G, 517A>T) had a significant effect on the body weight and egg production traits (p<0.05). In conclusion, these results might be useful as a basis for studies on the improvement of KNC breeds. Furthermore, these results suggest that the SNPs (c.739+726T>C, 513A>G, and 517A>T) located in the GHSR gene could be useful molecular genetic markers for KNCs.

• Journal of Ginseng Research
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• v.32 no.3
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• pp.179-186
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• 2008

Effect of pulverization on total solid, crude saponin, and acidic polysaccharide contents of dried red ginseng main root were tested. Several particle size samples, including red ginseng main root (non pulverized), $10{\sim}40$ mesh powder, $40{\sim}100$ mesh powder, and >100 mesh powder were used in the extraction. The sequential solvent extraction method (1st: 70% EtOH at $70^{\circ}C$ for 12 hr, 2nd: 70% EtOH at $70^{\circ}C$ for 12 hr, 3rd: water at $70^{\circ}C$ for 12 hr) was applied to extract the saponins and acidic polysaccharide. Extraction yield of total solid of pulverized red ginseng ($10{\sim}40$ mesh size) was increased to 20% compared with that of non-pulverized. Especially, the crude saponin content of pulverized red ginseng ($10{\sim}40$ mesh size) showed an increase of 47% over non-pulverized. No difference in the component ratio was observed by pulverization, when the individual ginsenosides were quantified by HPLC. Also, extraction yield of acidic polysaccharide of pulverized red ginseng ($10{\sim}40$ mesh size) was increased 57% compared with that of non-pulverized. The results suggested that pulverization might be useful for increasing the extraction yield of red ginseng components.