Graphite has hexagonal closed packing structure with two bonding characteristics of van der Waals bonding between the carbon layers at c axis, and covalent bonding in the carbon layer at a and b axis. Graphite has high tolerant to the extreme conditions of high temperature and neutron irradiations rather than any other materials of metals and ceramics. However, carbon elements easily react with oxygen at as low as 400C. Considering the increasing production of today of hydrogen and electricity with a nuclear reactor, study of oxidation characteristics of graphite is very important, and essential for the life evaluation and design of the nuclear reactor. Since the oxidation behaviors of graphite are dependent on the shapes of testing specimen, critical care is required for evaluation of nuclear reactor graphite materials. In this work, oxidation rate and amounts of the isotropic graphite (IG-110, Toyo Carbon), currently being used for the Koran nuclear reactor, are investigated at various temperature. Oxidation process or principle of graphite was figured out by measuring the oxidation rate, and relation between oxidation rate and sample shape are understood. In the oxidation process, shape effect of volume, surface area, and surface to volume ratio are investigated at 600℃, based on the sample of ASTM C 1179-91.

Quinoline insoluble formed by the heat treatment was hot-pressed near its softening point. The green body was stabilized in the temperature range of 300~400℃ and subsequently carbonized below 1300℃ in an argon atmosphere. The behaviors of QI formation was examined with varying the heat treatment temperature and the lapse of time of the sample carbonized at various temperatures. And the mechanical property, corrosion resistance, and friction behavior were also measured optimum content of mesophase pitch ensured a dense structure and high LC(002) value, which resulted in high mechanical properties, good corrosion resistance, and low-stable friction behavior.

This study was implemented to verify effectiveness related to job stress, depression or fatigue of hospital workers, by let them wearing necklaces with essential oils injected which were extracted from herb plants, as an alternative therapy. For this study, totally 60 people were selected who work in K hospital located in D city, in accordance with their agreement with participation in, and who were divided into 30 and 30 for a control group and an experimental group as appropriate subjects. The study was followed for 2 weeks from June 29 of 2015 by July 10 of 2015, by letting the experimental group wearing essential oils necklaces with a distance of 20 cm from noses during working time for 8 hours per day. After inhaling essential oils by wearing the necklaces, the job stress status didn’t have obvious difference between two groups statically, such as 104.1±11.3 points from 101.2±10.3 points for the control group and 104.7±9.8 points from 104.9±9.0 points for the experimental group. In case of the depression status, the control group had no difference such as 28.8±8.0 points from 29.4±9.0 points, and the experimental group had small decrease with 0.017 points such as 26.6±5.3 points from 28.5±5.6 points. In case of the fatigue status, the control group had no difference such as 75.7±19.7 points from 72.0±19.0 points, and the experimental group had small decrease with 0.049 points such as 64.3±20.0 points from 70.5±19.0 points.

We compared the long-term metabolic effects of equal amounts of carbohydrate from potato, rice and buckwheat on glycemic indices and blood lipids in healthy subjects. Nine healthy volunteers-2 men and 7 women were studied. All subjects ate diets based on the same-7-day rotating menu differing only in that the major source of carbohydrate (about 50% of daily total calories) came either from buckwheat, rice or potato. The study was conducted with a triple crossover design over three 7 day periods. On the morning of the 8th day, fasting blood was drawn from each subject to determine serum glucose, insulin, triglycerides, total and HDL-cholesterol. Subjects were then asked to eat breakfast with their respective carbohydrate within a 20 min period. Blood samples were drawn at 30, 60, 120 and 180 min after the start of breakfast to determine glucose and insulin levels. At 30 min the glucose response to the rice meal(7.15mmol/L) and potato meal(6.71mmol/L) were greater than the response to the buckwheat meal(5.855mmol/L) (P < 0.05). The mean area under the glucose response to the curve following the rice meal was greater than that following the buckwheat meal(P < 0.05). The insulin responses to the potato and rice meals at 30 and 60 min were greater than those to the buckwheat meal (P < 0.05). The mean area under the serum insulin response curve after the rice meal was greater than of buckwheat. Blood lipids, uric acid and glycosylated hemoglobin were not affected by the three meals. The study shows that the buckwheat meal has more beneficial effects on glycemic indices than either the rice meal or potato meal in healthy subjects.