• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1039-1040
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• 2011

• Korean Journal of Microbiology
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• v.6 no.3
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• pp.81-86
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• 1968

1. Amylolytic enzyme activities of Asp. oryzae and Asp. oryzae var. fulvus using the glucose as the carbon sources increased remarkably according to the decrease of the residual sugars. 2. The amylase productions of Asp. oryzae and Asp. oryzae var. fulvus were increased and enhanced when the organisms lave belen cultured in modified Koji media containing maltose as adaptive substrate. However, being devoid of maltose the level of amylase activities were lower and the begining of the production was prolonged. 3. The effects of C-sources on the amylase production of them were observed. The level of amylase activity varied with C-sources and their concentrations Marked increase of amylase production was afforded by starch and maltose. The effects of citric acid and tartaric acid were little or nothing. 4. Using the sucrose and lactose as the adaptive substrates both strains show the maximum amylolytic enzyme activities at the 3% concentrations of those sugars.

• Journal of Environmental Science International
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• v.14 no.8
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• pp.761-770
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• 2005

Scanning electron microscopy / energy dispersive X-ray analyzer(SEM/EDX) has played an important role for evaluation the source of atmospheric particle because it is a powerful tool for characterizing individual particles. The SEM/EDX system provides various physical parameters like optical diameter, as well as chemical information for a particle-by-particle basis. The purpose of the study was to classify individual particle emitted from the point sources based on clustering analysis and physico-chemical analysis by SEM/EDX. The total of 490 individual particle were analyzed at 8 point sources including coal-fired power plant, incinerator, H-C oil boiler, and metal manufacturing industry. The main components were Si and AI in the coal-fired power plant, Cl and Na in the domestic waste Incinerator, S in the H-C oil boiler and S and Fe in the metal manufactory industry, respectively.

• Journal of Power Electronics
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• v.14 no.4
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• pp.788-795
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• 2014

This paper demonstrates the dynamic behaviors of paralleled high power IGBTs using trench and fieldstop technologies. Four IGBTs are paralleled and standard deviation is adopted to represent the imbalance. Experiments are conducted under three different operation conditions and at different temperatures ranging from $-25^{\circ}C$ to $125^{\circ}C$. The experimental results show that operation at very low and very high temperatures usually aggravates the switching behaviors. There is a trade-off between the balance and the losses at low temperatures. These results can help in the design of heat sinks in paralleling applications confronting very low temperatures.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.9.1-9.5
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• 2013

Objectives Geographic Information Systems (GIS) is a powerful tool for assessing exposure in epidemiologic studies. We used GIS to determine the geographic extent of contamination by perfluorooctanoic acid, C8 (PFOA) that was released into the environment from the DuPont Washington Works Facility located in Parkersburg, West Virginia. Methods Paper maps of pipe distribution networks were provided by six local public water districts participating in the community cross-sectional survey, the C8 Health Project. Residential histories were also collected in the survey and geocoded. We integrated the pipe networks and geocoded addresses to determine which addresses were serviced by one of the participating water districts. The GIS-based water district assignment was then compared to the participants' self-reported source of public drinking water. Results There were a total of 151,871 addresses provided by the 48,800 participants of the C8 Health Project that consented to geocoding. We were able to successfully geocode 139,067 (91.6%) addresses, and of these, 118,209 (85.0%) self-reported water sources were confirmed using the GIS-based method of water district assignment. Furthermore, the GIS-based method corrected 20,858 (15.0%) self-reported public drinking water sources. Over half (54%) the participants in the lowest GIS-based exposure group self-reported being in a higher exposed water district. Conclusions Not only were we able to correct erroneous self-reported water sources, we were also able to assign water districts to participants with unknown sources. Without the GIS-based method, the reliance on only self-reported data would have resulted in exposure misclassification.

• Nutritional Sciences
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• v.5 no.2
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• pp.53-59
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• 2002

This study was conducted to examine the effects of dietary sources of fatty acids and protein on serum protein profiles, hepatic functional enzyme activities, mammary tumor incidence and tumor weight in 7, 12-dimethylbenz($\alpha$)anthracene (DMBA)-treated rats. The sources of dietary fatty acids were 18n6 (rich in linoleic acid), 18n3 (rich in linolenic acid) and 22n3 (rich in DHA) : sources of dietary protein were casein (C) and soy protein isolate (S). mammary tumors (MTs) were chemically induced by DMBA (9 mg/100 g body weight) which was gastrically intubated at 7 weeks of age. Each experimental diet was given for the following 25 weeks. Casein-fed rats (group C) exhibited significantly higher levels of weight gain and FER (food efficiency ratio) than did group S. Group C showed higher levels of serum protein and globulin, and higher albumin/globulin (A/G) ratios than group S. Liver functional enzyme activities (GOT, GPT, ALP, LDH, $\gamma$-GT) and LDH/GOT ratios were not influenced by dietary protein. GPT activity was lower in the group given 18n3, and ALP activity was lower in the group given 18n6. The incidence and total number of MTs appeared to be lower in the group given 22n3 than in the group given 18n3 or 18n6, even though the average weight of MTs was highest in the group given 22n3, The average weight of MTs was higher in the C group than in the S group. MT incidence had a positive correlation with LDH activity and LDH/GOT ratio. The average weight of MTs had a negative correlation with serum albumin levels and A/G ratios, and a positive correlation with ALP activity. This research suggests that the measurement of serum protein profiles and liver functional enzyme activities may be utilized to monitor the development of mammary tumors.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.3
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• pp.694-701
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• 1990

The cycle of heat engine which produces the maximum power output is constructed when heat sources are finitely constant, and the maximum power as a thermodynamic limit of the engine, is obtained. The characteristics of the maximum power cycle are as follows, which represent the operation conditions and design conditions of the heat engine to produce the maximum power output. In heat exchangers, the temperature profiles of the heat source and the working fluid have the same functional formula and the ratio of the working fluid temperature to the heat source temperature is constant. When heat capacity flow rates(product of the specific heat and the mass flow rate) of the working fluid as well as the heat source are constant, the values of those of working fluid exist between those of two heat sources. The relation of the temperature and the heat capacity flow rate is established without the states of the heat sources and the capacities of heat exchangers, which is ( $T_{h}$/ $T_{H}$)( $C_{h}$/ $C_{H}$)=( $T_{1}$/ $T_{L}$)( $c_{1}$/ $c_{L}$)=1. The capacity of the heat exchanger of hot side is equal to that of cold side regardless of the states of the heat sources and the total capacities of heat exchangers.hangers.ers.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.13-16
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• 2014

We have surveyed on significant progress in recent developments of accelerator-based pulsed X-ray sources has offered the opportunity for time-resolved studies on fast structure dynamics on the nanometer scale. The required and currently available techniques for time resolved X-ray diffraction measurements using the third-generation synchrotron radiation sources are summarized. Ultrafast X-ray experimental techniques are discussed for femtosecond studies at future synchrotron radiation sources.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.E4
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• pp.191-201
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• 2002

The pH, electric conductivity. and the major ionic components were analyzed for the precipitation samples collected at 1100 Site of Mt. Halla and Jeju city. The quality of analytical data was verified by the comparison of ion balances, conductivities and acid fractions, all of which correlation coefficients were over 0.952. The ionic strengths lower than 10$^{-4}$ M were found in 57 and 28% at 1100 Site and Jeju city respectively. The precipitation in Jeju city was influenced more by the oceanic effect than those in 1100 Site. The acidification of precipitation was caused mostly by S $O_4$$^{2-}$and N $O_3$$^{[-10]}$ in both areas, and the organic acids have contributed to the acidity with only 7~8%. The neutralization factors by N $H_3$ were about 44 and 47％ at the 1100 site and the Jeju city, respectively, whereas those by CaC $O_3$were 21 and 24%, and the free acidity were about 38 and 28％ at two sites. From the investigation of seawater and soil enrichment factors, the S $O_4$$^{2-}$, N $O_3$$^{[-10]}$ and N $E_4$$^{+}$ were immigrated by other sources rather than from the seawater or soil origins. but not in the case of $Mg^{2+}$, C $l^{[-10]}$ , N $a^{+}$, and $K^{+}$. Factor analysis has shown that the precipitation at the 1100 site had been influenced mostly by anthropogenic sources, followed by soil and sea-water sources. On the other hand, the precipitation at the Jeju city was mainly influenced by oceanic sources, followed by anthropogenic and soil sources.urces.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.159-165
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• 2015

The organic matter sources of phytoplankton and related environmental factors influencing algal bloom in Paldang reservoir were studied using nitrogen and carbon isotope ratio(${\delta}^{15}N$, ${\delta}^{13}C$). Phytoplankton samples for stable isotope analysis were collected from four points in reservoir using a plankton net. Physicochemical water quality, algal taxa and hydrological data were collected from published monitoring material. Phytoplankton samples were analyzed by IRMS. CN ratio of each sample was very similar to that of phytoplankton from literature cited. ${\delta}^{15}N$ of each sample was decreased during July. Mixing and dilution of nitrogen sources due to increment of influx by concentrated rainfall were considered as the main reason for the decline of ${\delta}^{15}N$. Based on analyzed ${\delta}^{15}N$ value of each sample, nitrogen source of Bughan river sample was presumed to come from soil. The nitrogen sources of Namhan river and Kyeongan stream samples seemed to be sewage or animal waste. Low ${\delta}^{15}N$ value in August (2012) seemed to be influenced by isotope fractionation due to the blooming of nitrogen-fixation blue-green algae (Anabaena spp.). Variation in ${\delta}^{15}N$ values particularly by blue-green algal bloom was considered the important factor for estimating the organic matter sources of phytoplankton.