• 한국식품영양학회지
• /
• 제28권1호
• /
• pp.40-46
• /
• 2015

Hamcho (Salicornia herbacea) extracts were evaluated for total polyphenol content, antioxidant and pro-oxidant activities. The total polyphenol content was 1.81 g and 0.72 g per 100 g of dried sample in water and ethanol extracts respectively. Both water and ethanol extracts of Hamcho significantly exhibited antioxidant activity. The scavenging activity of hydroxyl radical was 13.8~26.2% and 14.2~16.0% in water and ethanol extracts respectively. The inhibitory effect of conjugated diene formation was 24.6~39.1% and 28.4~39.6% in water and ethanol extracts respectively. However, pro-oxidative effect was also observed in the Hamcho extracts. The Hamcho water extract showed the pro-oxidant effect by enhancing the formation of hydroxyl radical and conjugated diene. The ethanol extract of Hamcho induced conjugated diene formation at 0.5 mg/mL but not at 1 mg/mL. The hydroxyl radical formation was not induced by the Hamcho ethanol extract. Taken together, these results show that Hamcho extracts can act as pro-oxidants by generating hydroxyl radical or conjugated diene in addition to their antioxidant properties. Therefore, this study suggests that the physiological properties of Hamcho and its use as food materials should be considered with caution because antioxidant dietary plants such as Hamcho possess possible adverse effects induced by pro-oxidant activity.

• 펄프종이기술
• /
• 제42권3호
• /
• pp.43-49
• /
• 2010

Recently, the use of fumigants for pest control of paper cultural heritages are limited because of the high toxicity of fumigants and the production of environment-harmfully compounds. Therefore, many non-chemical methods have been discussed and experimented. And it is recently focused on gamma radiation, which is one of non-chemical methods, for pest control of paper cultural heritage in Korea. In this paper, we carried out a gamma ray irradiation of papers including Hanji, copy paper, filter paper and then analyzed a physical properties and optical properties of paper sample to estimate the effect of gamma ray irradiation on paper properties. In result, gamma radiation have adverse effect on a physical properties and optical properties of paper, especially Hanji. Therefore, we have to carefully consider about using of gamma ray for pest control of paper cultural heritages.

• Journal of Microbiology and Biotechnology
• /
• 제17권3호
• /
• pp.398-402
• /
• 2007

Abstract Female mice post weaning were exposed to 20 kHz sawtooth electric and magnetic fields (EMF) with $6.25{\mu}T$ peak intensity for 6 weeks. Estrous cycles were checked using vaginal smears over the last 10 days of the experimental period. The vaginal smears from EMF-exposed mice revealed an increase in the frequency of one or two phases persisting. The number of estrous cycles less than 1 was more in the EMF-exposed group than in the sham control group. Furthermore, in the EMF-exposed group, the duration of proestrous and metestrous stages of the estrous cycle was significantly increased compared with the control group. In conclusion, our results suggest that exposure to 20 kHz sawtooth EMF may affect normal cycling of the estrous cycle by disrupting the female reproductive endocrine physiology. We should not disregard the possible adverse reproductive effect of the 20 kHz sawtooth EMF generated under the occupational exposure situation in females.

• Computers and Concrete
• /
• 제17권5호
• /
• pp.613-628
• /
• 2016

In this study, the influence of coarse aggregate size and type on chloride penetration of concrete was investigated, and the grey correlation analysis was applied to find the key influencing factor. Furthermore, the proposed 6-10-1 artificial neural network (ANN) model was constructed, and performed under the MATLAB program. Training, testing and validation of the model stages were performed using 81 experiment data sets. The results show that the aggregate type has less effect on the concrete permeability, compared with the size effect. For concrete with a lower w/b, the coarse aggregate with a larger particle size should be chose, however, for concrete with a higher w/c, the aggregate with a grading of 5-20 mm is preferred, too large or too small aggregates are adverse to concrete chloride diffusivity. A new idea for the optimum selection of aggregate to prepare concrete with a low penetration is provided. Moreover, the ANN model predicted values are compared with actual test results, and the average relative error of prediction is found to be 5.62%. ANN procedure provides guidelines to select appropriate coarse aggregate for required chloride penetration of concrete and will reduce number of trial and error, save cost and time.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권3호
• /
• pp.332-339
• /
• 2005

The effect of transinoculation of goat rumen liquor into sheep rumen on mimosine toxicity was studied. One adult Kutchi male goat having higher mimosine degradation capacity than sheep was gradually adapted to Leucaena leucocephala (Leucaena) leaves by feeding increasing level of eucaena leaves supplementation for 1 month. Six Bharat Merino rams (12-18 months of age) were divided into two equal groups with (group I) or without (group II) infusion of 200 ml of goat rumen liquor per animal. The mimosine degradation in groups I and II were 3.04 and 2.31; 3.90 and 3.73 mg per day per 10 ml rumen liquor respectively after 1 and 2 weeks of leucaena feeding leaves. Total rumen bacterial population in RGCA medium and in a selective medium containing iron showed an increasing trend in both groups, while the bacterial population growing in the presence of cellulose showed a decreasing trend. Animal performance data did not show any adverse effect. Results revealed that transinoculation of rumen liquor from leucaena leaves adapted goat to sheep rumen did not help to improve mimosine degradation in the sheep. The sheep transinoculated with goat rumen liquor displayed no in vivo improvements in nutrient utilization vis-a-vis mimosine metabolism.

• 노동경제논집
• /
• 제32권2호
• /
• pp.1-25
• /
• 2009

본 연구는 2006년도 고령화연구패널 자료를 이용하여 자녀 수가 자녀의 교육성과에 미치는 영향을 실증분석한다. OLS 추정 결과, 자녀 수가 증가함에 따라 자녀의 질, 즉 교육수준이 낮아진 것으로 나타났다. 이러한 실증 결과는 자녀의 수와 질의 대체관계 모형에 부합한다. 그러나 자녀 수의 내생성을 통제하기 위해 첫째 자녀의 성별을 도구변수로 이용한 추정 결과에서는 자녀 수의 증가가 자녀의 교육수준에 통계적으로 유의한 영향을 미치지 않는 것으로 나타났다. 이러한 결과는 자녀 1인당 교육투자액의 감소에 따른 교육수준의 저하가 자녀 수 증가로 인한 다른 효과에 의해 상쇄될 수 있음을 보여준다.

• 상하수도학회지
• /
• 제9권3호
• /
• pp.88-98
• /
• 1995

Several kinds of coagulants such as aluminum sulfate, PAC, PASS are being used to treat drinking water resulting in residual aluminum ions in the water. Recently, it has been reported that high intake of aluminum ion may cause neurological dieseases such as Alzheimer's diesease and presenile dementia. Because of the possible adverse effect, WHO and EEC recommand to regulate residual aluminum. The autorities in Korea also has plan of regulating residual alunimum from 1995. But there is not enough information about the range of residual aluminum ion concentration when the aluminum sulfate, PAC or PASS has been used as a coagulant. Therefore the study has been conducted to find out the range of residual aluminum ion concentration after using aluminum sulfate, PAC, and PASS. Furthermore the effect of turbidity and alkalinity have been investigated. The experimental results are summarized as; 1. Most of the residual aluminum ion concentrations were within $10^{-6}$ and $10^{-5}mole/l$. Three coagulants have not showed any considerable difference in the residual aluminum concentration up to 50 NTU. However PAC has showed the least residual aluminum in high turbidity water over 100 NTU. 2. The low alkalinity water having 25mg/l as $CaCO_3$ has showed less residual aluminum than the water having 50mg/l alkalinity. However, the difference was not significcant. 3. Even the lowest residual aluminum concentration was over 0.05mg/l. Therefore the process to reduce residual aluminum would be necessary in water treatment plants.

• 한국환경보건학회지
• /
• 제32권4호
• /
• pp.262-267
• /
• 2006

DBPs and T&O(taste-and-odor) compounds in drinking water is one of main source to deteriorate water quality. So, these compounds can cause adverse health effects and result in many consumer complaints aesthetically. This experiments carried out to investigate the effect of boiling water on DBPs and T&O compounds in the tap water. THMs and TCM concentration were reduced by 91.3%, 88.9% after 5 min of boiling, respectively. It is certainly, resulted from volatilization of TCM. TCAA concentration decreased when the water was boiled, too. By contrast, the concentration of DCAA was increased with duration time from boiling-point. The reduction of TCAA from the boiled water can be attributed to chemical transformation like decarboxylation. T&O compounds such as geosmin and 2-MIB was effectively removed by boiling of water, resulting in the removal efficiency of 97.1%, 94.4% after 5 min of boiling, respectively.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• 제4권1호
• /
• pp.59-69
• /
• 2000

The present study was undertaken in investigate the response to salinity and effect of plant growth regulators and proline under salinity stress on the germination and seedling growth of Vigna angularis. The protective effect of external Ca2+ on root elongation under saline conditions was also investigated. The seed germination of Vigna angularis decreased with an increase in salinity. The growth regulators GA3 was more effective than kinetin. At a higher salinity, low concentrations of kinetin and high concentrations of GA3 were more effective. The external application of proline and betaine improved germination under saline conditions. At a low salinity proline and betaine alleviated the salinity-induced inhibition of germination, yet at higher NaCl concentrations, proline and betaine were both ineffective. Exposure to salinity during germination was accompanied by an increase in the proline content, thereby suggesting that one compatible solute in the germinating seed would seem to be proline. The inhibition of germination by high NaCl concentrations was relatively more severe in scarified seeds than in intact seeds, indicating that the seed coat acts as a partial barrier to an Na2+ ameliorated the adverse effect of salinity stress.

• Asian-Australasian Journal of Animal Sciences
• /
• 제12권6호
• /
• pp.881-885
• /
• 1999

A growth study was conducted for 238 days in twenty crossbred cattle calves to observe the effect of dietary concentrate supplement on blood biochemical changes and serum testosterone levels. The calves were divided into four groups (A, B, C and D) of five animals each. Calves of groups A and B were fed 60% and 30% concentrate, respectively, supplying equal amount of protein along with wheat straw. The calves in group C received 30% concentrate in their diet for 1 to 119 days of experiment and 60% concentrate during 120~238 days of experiment and vice versa in group D. Mean DM and TDN intake were significantly higher in group A than group B, C or D, resulted in higher daily growth rate in the former group. Blood glucose level was significantly higher in group A where as blood urea, hemoglobin, total protein, albumin, and globulin levels remained unchanged among the groups. Serum testosterone level increased with the increasing age of the animals but the level remained same in the animals of group A, B, C and D. A 30% concentrate diet does not have any severe adverse effect on the performance of crossbred cattle.