• Journal of Life Science
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• v.15 no.5 s.72
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• pp.840-846
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• 2005

This study was carried out to investigate the effect of electron beam irradiation and cooking temperature on physico-chemical characteristics and lipid oxidation of beef. A total of six beef carcasses ($280\∼300 kg$) that were quality grade $1^{+}$(marbling score No.7, meat color No.4, maturity No.1, texture No.1) was purchased at the commercial slaughter house. The carcasses were transported and washed using high pressure water, and pasteulized with $ 50\% $ ethyl alcohol in the laboratory. After the carcasses were deboned and trimmed, loin and round were taken out to make steak (1.5cm thickness) or ground beef respectively. Samples were wrap or vacuum packaged and irradiated with 0, 3, 4.5, 6 and 7.5 kGy using electron-beam accelerator at Samsung Heavy Industries Ltd. Co. (in Taejun). Irradiated samples were cooked with different methods(electronic pan and gas oven) and temperatures ($ 60^{\circ}C, 70^{\circ}C and 80^{\circ}C$) and used to measure fatty acid composition, TBARS, cholesterol oxide products and panel test scores. The content of saturated fatty acids increased by increasing heating temperature in oven boiling steak (OBS) and pan boiling steak (PBS), and there was no difference by electron-beam irradiation. Both irradiated and non-irradiated treatment were high as the heating temperature increased in TBARS by heating temperature in PBS (p < 0.05) and the amount of Malonaldehyde (MA), standard of fat deterioration, was increased in OBS (p < 0.05). Non-irradiated and 3, 6 kGy treatment produced about 2 fold amount of MA at $ 60^{\circ}C $ compared with $ 80^{\circ}C $. In comparison with PBS, OBS produced much amount of MA and a bit different from non-irradiated treatment but did not show no tendency. As irradiation levels and heating temperature increased, the amount of cholesterol oxides products was increased and also pan-heating method, direct heating method, significantly increased the degree of oxidation compared with oven-heating method, indirect heating method (p < 0.05).

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.4
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• pp.239-248
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• 2006

This study was conducted not only to investigate effects of different supplementation levels of Acanthopanax senticosus leaves on feed intakes, nutrient digestibility, nitrogen retention, and blood metabolites in Korean black goats but also to obtain basic data for nutritive value of Acanthopanax senticosus leaves and production of high quality functional animal products. Twelve Korean black goats were allotted to treatments in four groups of three goats per treatment and then they were housed in individual metabolism cages with completely random arrangements for 21 days. Four treatments were separated into controls and three different supplementation levels of Acanthopanax senticosus such as 10, 20 and 30%, respectively. For the chemical composition of experimental diets, crude protein (CP) contents of controls were 13.39% and those of supplementation treatments were lowered with increasing levels of Acanthopanax senticosus. Control groups tended to have higher acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents as compared to supplementation groups, but non-fibrous carbohydrate (NFC) contents tended to be higher far supplementation groups than those for controls. Feed intakes had no significant difference among treatments, but digestible dry matter amounts were significantly higher for 20 and 30% supplementation groups than those for other treatments. Dry matter intakes per metabolic body weight and their ratio per body weight were highest in 20% group, but those of 40% groups were lowest (p<0.05). Crude protein, ADF and NDF digestibilities were significantly higher in Acanthopanax senticosus supplementation groups in comparison to controls (p<0.05), and in particular, they were increased with increasing supplementation levels of tranthopanax senticosus. Nitrogen retention was significantly higher for 20 and 30% treatments than those fur controls (p<0.05). Plasma urea nitrogen concentration was significantly lower for 30% supplementation group than those fur controls (p<0.05). Furthermore, plasma triglyceride concentration was significantly lower for Acanthopanax senticosus groups than those for controls (p<0.05). The results showed that supplemental level of 20% Acanthopnnax senticosus leaves to Korean black goats improved nutrient digestibility, nitrogen retention, and plasma urea nitrogen and triglyceride concentrations. Consequently, it might contribute to more efficient production of Korean black goats.

• Journal of the Korean earth science society
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• v.23 no.3
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• pp.280-293
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• 2002

In this study, we analyzed the long-term distribution patterns of $CH_4$ determined from the Moo-Ahn (MAN) observatory in relation with those derived from the world major background monitoring sites. Comparison of the data were made using those data sets collected for the period between Aug. 1995 to Dec. 1991. The mean $CH_4$ concentration of MAN observatory was measured to be 1898${\pm}$85.3 ppb, recording the highest concentration of all the monitoring sites. When the concentration of $CH_4$ for different stations was compared over latitudinal scale, its concentration appeared to increase systematically as a function of latitude with an exception of MAN (and the other Korean monitoring site at Tae Ahn). Moreover, such phenomenon was more distinctive in Northern than Southern Hemisphere. According to the analysis of the monthly distribution patterns of $CH_4$ at MAN observatory, its concentration level began to increase from the months of February/March and peaked during August. In addition, when the level of oscillation in monthly concentrations (between the maximum and minimum values) was checked, differences were significant between MAN and other monitoring stations. If the rate of concentration change was checked using the data sets collected for this limited time period in terms of linear regression analysis, results for MAN showed the highest annual increasing rate of 16.5 ppb. It is hence suggested that the largest variability in the $CH_4$ distribution patterns at MAN observatory may be reflected by the high irregularity in its source/sink processes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.885-892
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• 2002

The purpose of this research was to prove the excellency of unpolished (brown) rice with respect to nutritional composition and to compare chemical composition among six varieties of rice. Some nutritional composition in the Polished (well -milled) rice and unpolished (brown) rice of the six typical Korean varieties (Chucheong, Hwasung, Odae, Ilmi, Dongjin, Ilpum) were determined. Most of nutrients in the brown rice were much greater than those in the milled rice and there was significant difference among rice varieties in some chemical compositions. The major minerals of milled rices were Ca, 6～15 mg%;P, 91～125mg%;Fe, 0.3～1.2mg%; Na, 10～14mg%;K, 106～205 mg%; Zn, 1.0～1.8mg%; and Mg, 32～58 mg%. The mineral contents of brown rices wre Ca, 4～11mg%;P, 92～286mg%;Fe, 1.3～1.9mg%;Na, 12～15mg%;K, 243～320mg%;Zn, 1.5～2.3mg%;Mg, 112～140mg%. Major fatty acids in six rice varieties were linoleic acid, oleic acid and palmitic acid, which comprised of about 93% of total fatty acid. Amino acid analysis showed that aspartic acid, glutamic acid, arginine and leucine were major amino acids, whereas histidine, threonine and tryptophan were minor ones of rice. Most ammo acid contents was higher in Ilmi than the other varieties. The contents of vitamin in brown rices were considerably higher than those in well-milled rice. There was not significant difference in total dietary fiber among rice varieties : 1.1～1.2% for milled rice,3.2～3.5% for brown rice.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.252-259
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• 2017

Purpose: The purpose of this study was to compare and analyze the wear of a prosthesis for 6 months after restoration with implant-supported fixed dental prosthesis made of either zirconia or gold. Materials and Methods: This study was conducted on patients requiring implant-supported fixed dental prostheses on first or second molar from January, 2015 to January, 2016. A total of 47 prostheses and antagonists were examined. Occlusal surface was recorded by impression of each prosthesis and antagonist 1 week and 6 months after prosthesis delivery. The digital files were created by impression scan. Occlusal shapes of 1 week and 6 months were compared and wear of prostheses and antagonists was analyzed. The Mann-Whitney test was used to analyzed the result data underwent normality test using SPSS (Version 23.0, IBM Corporation) Results: Mann-Whitney test revealed that there was no statistically significant difference in the median amount of mean vertical wear for 6 months in zirconia ($50.84{\mu}m$) and gold ($42.84{\mu}m$) prostheses (P > 0.05). When the opposing teeth were natural, the median amount of mean vertical wear of zirconia and gold prostheses was $47.72{\mu}m$ and $41.97{\mu}m$, respectively, and the median amount of mean vertical wear of enamel was $47.26{\mu}m$ and $44.59{\mu}m$, respectively. Statistical analysis showed no significant difference (P > 0.05). Conclusion: Despite the short study period and the small number of experimental groups, zirconia and gold showed no significant difference in wear during the first 6 months. Opposing natural enamel also showed no significant difference in the wear.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.2
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• pp.169-195
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• 2020

With the increase in air transportation, air delays are inevitable, and the damage of air consumers is also increasing. In Korea, the Ministry of Land, Infrastructure and Transport announced 「the Criteria for Protection of Users of Air Transportation」, but the Criteria does not include aviation delays except Tarmac delay, but this criteria is a only public notice, not an Act. Lately, a clause about Tarmac delay was newly established as Article 61bis of the Aviation Business Act, and was enacted from May 27, 2020. The Air carriers' Tarmac delay are subject to mandatory regulations. This research showed how lawsuits were implemented for the protection of aviation consumers related to aviation delays prior to the imposition of this article. In addition, the study examined at the public law level, whether the protection rights of aviation consumers is the fundamental right under the Constitution and whether the government should be the main subjects of consumer protection. And then we studied the effect of enforcement about the Tarmac Delay Rule of the United States. This rule acts as a federal regulation. Subsequently, the Biscone case presented that it was not easy for the US court to accept a lawsuit against the passengers for tarmac delay. There are limitations in remedying the damages of airline consumers due to delays either in Korea trial or the U.S. trial. Finally it needs strengthening the penalty to secure the effectiveness of the Tarmac delay clause regulations. In order to protect airline consumers, it was proposed that the protection of aviation consumer law should be established through the revision as the Enforcement Rules of the Airline Business Act.

• Korean Journal of Health Education and Promotion
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• v.4 no.2
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• pp.32-45
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• 1987

This research attempted to identify basic data related to the nursing of teenagers that would aid in the establishment of nursing care that would meet their health needs, and further to identify which health related activities, are carried out by teenagers, so that appropriate nursing service and health care can be planned for them. The subjects of the study were students at one seoul boys high school and one seoul girls high school. Data was collected between December 16 and. December 19, 1986. The tool used in the study was a questionnaire about the health needs and concerns of teenagers developed at John's Hopkins University and translated and standardized for Korean students. The date was coded fer analysis using' the SPSS program and percentages, mean scores' with standard deviations, Chi square test, and ANOVA, were used for analysis. The following results were obtained : 1. The health status of teenagers : Looking at the health status of teenagers, it can be seen from this study that over half of the teenagers questioned replied that they do not get enough sleep, further that even though they are feeling sick they go to school. However, when asked what they thought of their health, the majority replied that they were healthy, and although they thought about their bea1th was not a concern when they were planning other activities. With regard to health status, there was a significant difference between male and female students concerning whether they were handicapped with regard to sleep, their opinion about their own health, and the amount of time lost from school for illness over the past month, whether in comparison with those of the same age they had more sickeness of not, and whether they had to think about their health when planning other activities. There was also a significant difference according to the age of the students as to whether they worried more about being sick than other members of their age group. 2. Health Realted Activeties of Teenagers : Most of the students in the study reported that they did not get regular physical examinations of health check ups, nor did they get legular examinations when they were sick. Few students reported that they smoked. Most of the students reported taking part in activities that promoted health but about half also reported that they were involved in activities that they knew were detrimental to their health. Further on statistical analysis, there was a significant difference between male and female students regarding health related activities and problems of teenagers and whether they were examined by a medical person when they were sick. 3. The degree of interest and responsibility of teenagers for their own Health: In the section on responsibility for health, the teenagers replies were highest, 4. 5, for the statements, "My health is dependent how much I pay attention to it" and "My health is responsibility" and lowest, 3. 9, for the statement "I am healthy because I have cared for my health so far." With regard to interest in their own health, the majority of the teenagers in the study were more concerned about their studies, high score of 4. 4, than in matters directly related to health. The use of drugs, birth control and masturbation were low on the interest scale. The more involvement in health related activities, the higher the score was for responsibility and this difference was significant, but this did not apply to interest in health. Similarly there was also a significant difference regarding participation in activities known to be detrimental to health and responsiblity for health, but not for interest in health.

• Journal of Korean Society of Forest Science
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• v.45 no.1
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• pp.62-67
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• 1979

Ultraviolet microscopy of ultrathin sections of wood has proved to be one of the useful means for determining the lignin distribution in the various regions of the cell wall. Also, spectral approach and quantitative analysis of isolated compound middle lamella fraction from birch xylem have revealed that the lignin associated with the vessel secondary wall and middle lamella is composed predominantly of gualacylpropane units. Lignin deposited in the fiber and ray parenchyma secondary walls is composed mostly of syringylpropane units. The middle lamella lignin around fibers and ray cells contains both guaiacyl and syringyl propane quits. On the basis of the results above, this research was carried out to clarify the origin of milled wood lignin (MWL) by analysing the chemical characteristics of ML MWLs extracted at various milling stages. The amount of phenolic hydroxyl-, ${\alpha}$-carbonyl-, and methoxyl-group in the MWL's increases the milling time. And progressive mining contributes to the merease of ratio of syringylaldehyde to vanillin(S/V ratio) after nitrobenzene oxidation of MWL. Accordingly, It could be concluded that milled wood lignin extracted at the initial milling stage derives from compound middle lamella region of cell wall, whereas, with progressive milling, lignin of secondary wall of fiber is introduced gradually to milled wood lignin. These results are suggesting that heterogeneous chemical structure of lignins in hardwood exists. Although milled wood lignin at the initial stage seems to have lower molecular weight in comparison with milled wood lignin extracted at final milling stage from the result of Gel-filtration curves, further study would be required on molecular weight distribution of milled wood lignin in future.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.93-102
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• 2016

This research was conducted for major cultivated chestnut (Castanea spp.) in Korea to compare chestnut quality characteristics according to storage temperatures ($4^{\circ}C$ vs. $-1^{\circ}C$) and cultivars. Color, hardness, soluble solids content (SSC), rate of decay and sensory evaluation were investigated during 16 weeks storage. Cultivars 'Tsukuba' and 'Ishizuchi' showed the least pericarp color change while cultivars 'Riheiguri' and 'Daebo' showed the most pericarp color change during storage. Chestnut fruits stored at $-1^{\circ}C$ showed less pericarp color change than those stored at $4^{\circ}C$. Cultivars 'Arima' and 'Tanzawa' exhibited the decrease tendency of hardness with lowest hardness during storage at $-1^{\circ}C$. Chestnut fruits stored at $4^{\circ}C$ showed high hardness than those stored at $-1^{\circ}C$. Cultivars 'Riheiguri' showed the highest increase of SSC, while cultivar 'Arima' showed the lowest increase of SSC after 16 weeks of storage. The SSC increased in nuts from all cultivars at both temperatures, but nuts stored at $-1^{\circ}C$ showed higher increases in SSC than nuts stored at $4^{\circ}C$. Cultivars 'Ishizuchi' and 'Riheiguri' showed high rates of decayed nuts in contrast to cultivars 'Daebo', 'Okkwang' and 'Tanzawa' that showed low rates of decayed nuts during storage. The chestnut fruit stored at $-1^{\circ}C$ showed less decay than fruit stored at $4^{\circ}C$. Texture and sweetness were tested for sensory evaluation. Among the tested cultivars, 'Riheiguri', 'Daebo' and 'Tsukuba' showed hard texture and very sweetness, while 'Tanzawa' showed relatively soft texture. 'Arima' and 'Okkwang' showed weak sweetness during storage. Nuts stored at $4^{\circ}C$ exhibited harder texture than nuts stored at $-1^{\circ}C$ while $-1^{\circ}C$ exhibited more sweetness than nuts stored at $4^{\circ}C$. Chestnuts for hard texture and short-term storage (less than one month), $4^{\circ}C$ will be a proper storage temperature, while in order to store long-term (more than 4 month), $-1^{\circ}C$ will be a proper storage temperature. Result from this study provide base-line data of postharvest management for Korean cultivated chestnut as well as contributing increased product value and income for chestnut producers.

• Journal of Science Education
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• v.36 no.2
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• pp.235-250
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• 2012

This paper aims to find out whether or not elementary school students recognize and understand scientific units that they encounter in their everyday life. To select appropriate units for the survey, first, scientific units in elementary textbooks of science and other science related subjects were analyzed. Then it was examined how these units were related to the learners' daily life. The participants in the current survey were 320 elementary school 6th graders. A questionnaire consisted of 11 units of science, such as kg for mass, km for distance, L for volume, V for voltage, s for time, $^{\circ}C$ for temperature, km/h for speed, kcal for heat, % for percentage, W for electric power, pH for acidity, which can often be seen and used in daily life. The students were asked to do the following four tasks, (1) to see presented pictures and select appropriate scientific units, (2) to write reasons for choosing the units, (3) to answer what the units are used for, and (4) to check where to find the units. The data were analyzed in terms of the percentage of the students who seemed to well recognize and understand the units, using SPSS 17.0 statistical program. The results are as follows: Regarding the general use of the units, it was revealed that almost the same units were repeated in science and other subject textbooks from the same grade. With an increase of the students' grade more difficult units were used. As for the use of each unit, it was found that they seemed to relatively well understand what these units kg, km, L, $^{\circ}C$, kcal, km/h, and W stand for, showing more than 91% right. However, the units of V, s, in particular, %, and pH did not seem to be understood. With respect to the recognition of the units, most students did not recognize such units as L for volume and pH for acidity, probably because the units are difficult at the elementary level in comparison to other scientific units. The students indicated that schools were the best place where they could learn and find scientific units related to life, followed by shops/marts, newspapers/broadcasting, streets/roads, homes, and others in that order. The results show that scientific unit learning should be conducted in a systematic way at school and that teachers can play a major role in improving students' understanding and use of the units.