• Analytical Science and Technology
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• v.18 no.1
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• pp.5-12
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• 2005

It has been established that soft error of high precision electronic circuits can be induced by alpha particles emitted from the naturally occurring radioactive impurities such as U, and Th. As the electronic circuits have recently become lower dimension and higher density, these alpha-particle emitting radioactive impurities have to be strictly controlled. The aim of this study is to develop of NAA (Neutron Activation Analysis) and gamma-spectrometry to improve the analytical sensitivity and precision of U and Th. A new NAA method has been established using the HTS (Hydrulic transfer system) irradiation facility which has been used to produce radioisotopes for industries and medicines instead of the PTS (pneumatic transfer system) irradiation facility which has been used in general NAA. When the ultratrace impurities have to be analyzed by NAA, background gamma-ray spectra induced from $^{222}Rn$ and its progenies in air is serious problem. This unstable background has been eliminated or stabilized by the use of a nitrogen purging system. Ultra trace amounts of U (0.1 ng/g) and Th (0.01 ng/g) in high purity silica used for EMC could be analyzed by the use of HTS-NAA and low background gamma-spectrometry.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.29-35
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• 2003

In order to find the feasibility of feeding raw or processed cotton (Gossypium) seed meal (CSM), 30 male crossbred lambs were randomly assigned to 5 dietary treatments with 6 animals each. Lambs were fed each of the isonitrogenous and isocaloric concentrate mixtures containing 30% deoiled groundnut cake (DGNC) (reference diet), 40% raw, 45 minute cooked, 1% $Ca(OH)_2$ or iron (1 part free gossypol:0.3 parts iron) treated CSM (replacing about 50% nitrogen moiety of reference concentrate mixture). The concentrate mixture was fed to meet 80% of CP requirements (NRC, 1985) along with ad libitum maize (Zea mays) hay for 180 days. Incorporation of raw or processed CSM did not affect the palatability of diets as evidenced by higher (p<0.01) or comparable overall daily intakes of DM and protein (CP and Digestible CP) per kg $W^{0.75}$ by lambs in comparison to reference group. Intakes of DE and ME increased (p<0.01) due to inclusion $Ca(OH)_2$ treated CSM in diets, while the intakes were lower (p<0.01) on iron treated CSM based diet when compared with reference diet. The intakes of DM, CP, TDN, DE and ME by reference and experimental lambs were higher than the requirements stipulated by NRC (1985). The growth rate was highest (p<0.01) in lambs fed on diets with cooked CSM followed by those fed raw or $Ca(OH)_2$ treated CSM based diets. The growth of lambs fed on iron treated CSM diets was depressed (p<0.01) in comparison to that of other experimental lambs probably due to increased iron intake (889 mg/kg DM of diet) which was much higher than the toxic levels of 500 ppm (NRC, 1980). The lambs on various diets utilized DM with similar efficiency while the utilization of energy (TDN, DE and ME) was more efficient (p<0.01) when the diets contained raw or cooked CSM in comparison to that of reference diet. The lambs fed raw and $Ca(OH)_2$ treated CSM incorporated diets utilized DCP with higher (p<0.01) efficiency than the lambs fed reference diet. The feed cost per kg weight gain was lower (p<0.01) on raw, cooked and $Ca(OH)_2$ treated CSM based diets in comparison to reference diet. Cooking of CSM for 45 minutes further reduced the feed cost of weight gain.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.619-626
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• 2007

It is of special interest in our membrane separation technology due to its low energy consumption and cost, relatively simple equipment, low investment and operation cost, et al. Full scale utilization of such processes can be widely utilized to the various fields. Using the difference of permeability of gas molecules between the filter layers, it is able to separate effectually pure gases from the mixed gases. In this paper, the membranes of PDMS, ${\gamma}-radiated$ PDMS, PTFE, PTFE-X are chosen to develop the predictive model for the separation of pure gases such as oxygen, nitrogen, hydrogen, and other gases from mixed gases. By utilizing the thermodynamic gas properties($\sigma$, $\varepsilon/k$) and experimental data of gas transport characteristics for different polymer membranes, it is able to develop the predictive model equation under the influence of temperature, pressure and polymer characteristics. Predictive model developed in this research showed good agreement with experimental data of gas permeability characteristics for develop four different polymer membranes. The proposed model can also be extended to the general equation for predicting the separation of gases based on the properties of polymeric membranes.

• Journal of Nutrition and Health
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• v.9 no.3
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• pp.1-7
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• 1976

This study was carried out to observe the nutritive effects of feeding rice diet and rice diet mixed with barley or millet, or both on the growth rate and biological availability of some nutrients by albino rats. The experimental diets were prepared on the basis of isocaloric and isonitrogenous containing 357 kcal of energy and 12g of protein per 100g of diet. The experimental animals weighing about 66g of both sexes were fed on 7 kinds of diets such as control diet, rice (100%) diet, rice (70%)+barley (30%) diet, rice (70%)+millet (30%) diet, rice (70%)+barley (20%)+millet (10%) diet, rice (70%)+barley (15%)+millet (15%) diet, and rice (70%)+barley (10%)+millet (20%) diet for 7 weeks. The results obtained are summarized as follows; 1. The gain in body weight was higher for barley and/or millet mixed with rice diet groups than rice diet group with no statistical difference. 2. Although there was no difference in the amount of food consumed by experimental groups, the food efficiency ratio was sightly higher for the miked diet groups than rice atone diet group. 3. The protein efficiency ratio was also higher for barley and millet miked with rice diet groups than rice diet group, although statistical significance was not found. 4. Apparent digestibility of protein of rice diet group was significantly (P<0.01) higher than any other diet group. Although there was no remarkable difference between mixed diet group was found, the apparent digestibility of protein tended to increase when rats were fed on the barley and millet mixed with rice diet. Apparent biological value (p<0.05) and net protein utilization (p<0.01) were also significantly higher for the groups fed mixed diet with barley and/or millet than rice diet group, and those for millet alone mixed diet were slightly lower. 5. The content of total nitrogen in the liver and of protein in serum were not significantly different among experimental groups. It may be concluded from the above results that an adequate supplementation of rice with other cereals and mixing ratio of other cereals to rice were important for the efficient utilization of protein in total diet.

• Journal of environmental and Sanitary engineering
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• v.24 no.4
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• pp.1-26
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• 2009

We conclude the following with air pollution data measured from city measurement net administered and managed in Gwangju for the last 7 years from January in 2001 to December in 2007. In addition, some major statistics governed by Gwangju city and data administered by Gwangju as national official statistics obtained by estimating the amount of national air pollutant emission from National Institute of Environmental Research were used. The results are as follows ; 1. The distribution by main managements of air emission factory is the following ; Gwangju City Hall(67.8%) > Gwangsan District Office(13.6%) > Buk District Office(9.8%) > Seo District Office(5.5%) > Nam District Office(3.0%) > Dong District Office(0.3%) and the distribution by districts of air emission factory ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%). That by types(Year 2004~2007 average) is also following ; Type 5(45.2%) > Type 4(40.7%) > Type 3(8.6%) > Type 2(3.2%) > Type 1(2.2%) and the most of them are small size of factory, Type 4 and 5. 2. The distribution by districts of the number of car registrations is the following ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%) and the distribution by use of car fuel in 2001 ; Gasoline(56.3%) > Diesel(30.3%) > LPG(13.4%) > etc.(0.2%). In 2007, there was no ranking change ; Gasoline(47.8%) > Diesel(35.6%) > LPG(16.2%) >etc.(0.4%). The number of gasoline cars increased slightly, but that of diesel and LPG cars increased remarkably. 3. The distribution by items of the amount of air pollutant emission in Gwangju is the following; CO(36.7%) > NOx(32.7%) > VOC(26.7%) > SOx(2.3%) > PM-10(1.5%). The amount of CO and NOx, which are generally generated from cars, is very large percentage among them. 4. The distribution by mean of air pollutant emission(SOx, NOx, CO, VOC, PM-10) of each county for 5 years(2001~2005) is the following ; Buk District(31.0%) > Gwangsan District(28.2%) > Seo District(20.4%) > Nam District(12.5%) > Dong District(7.9%). The amount of air pollutant emission in Buk District, which has the most population, car registrations, and air pollutant emission businesses, was the highest. On the other hand, that of air pollutant emission in Dong District, which has the least population, car registrations, and air pollutant emission businesses, was the least. 5. The average rates of SOx for 5 years(2001~2005) in Gwangju is the following ; Non industrial combustion(59.5%) > Combustion in manufacturing industry(20.4%) > Road transportation(11.4%) > Non-road transportation(3.8%) > Waste disposal(3.7%) > Production process(1.1%). And the distribution of average amount of SOx emission of each county is shown as Gwangsan District(33.3%) > Buk District(28.0%) > Seo District(19.3%) > Nam District(10.2%) > Dong District(9.1%). 6. The distribution of the amount of NOx emission in Gwangju is shown as Road transportation(59.1%) > Non-road transportation(18.9%) > Non industrial combustion(13.3%) > Combustion in manufacturing industry(6.9%) > Waste disposal(1.6%) > Production process(0.1%). And the distribution of the amount of NOx emission from each county is the following ; Buk District(30.7%) > Gwangsan District(28.8%) > Seo District(20.5%) > Nam District(12.2%) > Dong District(7.8%). 7. The distribution of the amount of carbon monoxide emission in Gwangju is shown as Road transportation(82.0%) > Non industrial combustion(10.6%) > Non-road transportation(5.4%) > Combustion in manufacturing industry(1.7%) > Waste disposal(0.3%). And the distribution of the amount of carbon monoxide emission from each county is the following ; Buk District(33.0%) > Seo District(22.3%) > Gwangsan District(21.3%) > Nam District(14.3%) > Dong District(9.1%). 8. The distribution of the amount of Volatile Organic Compound emission in Gwangju is shown as Solvent utilization(69.5%) > Road transportation(19.8%) > Energy storage & transport(4.4%) > Non-road transportation(2.8%) > Waste disposal(2.4%) > Non industrial combustion(0.5%) > Production process(0.4%) > Combustion in manufacturing industry(0.3%). And the distribution of the amount of Volatile Organic Compound emission from each county is the following ; Gwangsan District(36.8%) > Buk District(28.7%) > Seo District(17.8%) > Nam District(10.4%) > Dong District(6.3%). 9. The distribution of the amount of minute dust emission in Gwangju is shown as Road transportation(76.7%) > Non-road transportation(16.3%) > Non industrial combustion(6.1%) > Combustion in manufacturing industry(0.7%) > Waste disposal(0.2%) > Production process(0.1%). And the distribution of the amount of minute dust emission from each county is the following ; Buk District(32.8%) > Gwangsan District(26.0%) > Seo District(19.5%) > Nam District(13.2%) > Dong District(8.5%). 10. According to the major source of emission of each items, that of oxides of sulfur is Non industrial combustion, heating of residence, business and agriculture and stockbreeding. And that of NOx, carbon monoxide, minute dust is Road transportation, emission of cars and two-wheeled vehicles. Also, that of VOC is Solvent utilization emission facilities due to Solvent utilization. 11. The concentration of sulfurous acid gas has been 0.004ppm since 2001 and there has not been no concentration change year by year. It is considered that the use of sulfurous acid gas is now reaching to the stabilization stage. This is found by the facts that the use of fuel is steadily changing from solid or liquid fuel to low sulfur liquid fuel containing very little amount of sulfur element or gas, so that nearly no change in concentration has been shown regularly. 12. Concerning changes of the concentration of throughout time, the concentration of NO has been shown relatively higher than that of $NO_2$ between 6AM~1PM and the concentration of $NO_2$ higher during the other time. The concentration of NOx(NO, $NO_2$) has been relatively high during weekday evenings. This result shows that there is correlation between the concentration of NOx and car traffics as we can see the Road transportation which accounts for 59.1% among the amount of NOx emission. 13. 49.1~61.2% of PM-10 shows PM-2.5 concerning the relationship between PM-10 and PM-2.5 and PM-2.5 among dust accounts for 45.4%~44.5% of PM-10 during March and April which is the lowest rates. This proves that particles of yellow sand that are bigger than the size $2.5\;{\mu}m$ are sent more than those that are smaller from China. This result shows that particles smaller than $2.5\;{\mu}m$ among dust exist much during July~August and December~January and 76.7% of minute dust is proved to be road transportation in Gwangju.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.625-636
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• 2005

This study was conducted to determine effects of different ratios (3.5, 3.0 and 2.5) of nonfibrous carbohydrate (NFC) to ruminally degradable protein (RDP) on in vitro fermentation and lactation performance of dairy cows and optimum ratio of NFC to RDP in dairy rations. In vitro trial was conducted up to 12 hr with ruminal fluidtaken from ruminally cannulated Holstein cows. The level of dietary NFC did not affect ruminal pH. The ammonia-N concentration was not significantly different among treatments until 6 hr incubation, however, it was significantly (P < 0.05) decreased as the ratio of dietary NFC to RDP increased on 9 and 12 hr incubation. For volatile fatty acids, concentrations of both acetate and propionate were significantly (P < 0.05) increased on 3 hr incubation as dietary NFC contents of treatments increased, in other incubation times, they had no significant differences among treatments. Valerate and A:P ratio were not affected by the ratio of NFC to RDP. Isoacids and total VFAs were significantly (P < 0.05) increased with increasing dietary NFC contents and their values were highest in the treatment of 3.0 ratio. Meanwhile, for in vivo trial, 18 Holstein lactating cows were allotted to treatments in three groups of 6 cows. They were employed for 24 weeks to investigate nutrient intakes, and milk yield and composition according to different ratios of dietary NFC to RDP. Intakes of dry matter and energy were significantly (P < 0.01) increased, but NDF intake was significantly (P < 0.01) decreased as the ratio of dietary NFC to RDP increased. Milk yield for the ratio of 3.5 (32.7 kg) was significantly (P < 0.05) higher than those of other treatments. Milk fat (%) was significantly (P < 0.05) higher for the treatments of 3.0 (3.79 %) and 2.5 (3.79 %) than that (3.48 %) for the ratio of 3.5, but milk fat yield was not different among treatments. Contents and yields for milk protein and solids-not fat were linearly (P < 0.01) increased as the ratio of dietary NFC to RDP increased. However, milk urea nitrogen concentration was significantly (P < 0.05) decreased with increasing dietary NFC levels. Our results showed that the increasing level of NFC in the diet of dairy cows enhanced ruminal fermentation, N utilization and milk production and suggested that maximal fermentation and lactation performance were achieved when the dietary ratio of NFC to RDP was more than 3.0 in dairy rations.