• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1233-1238
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• 2014

In this thesis, it is investigated the characteristics of Dye Sensitized Solar Cell (DSSC) according to variation of $TiO_2$ thickness (6, 12, 18, and $24{\mu}m$) and three distinct $TiO_2$ sintering temperatures (350, 450 and $550^{\circ}C$) by XRD, SEM, I-V and UV-Vis spectrophotometer. According to sintering temperature, $TiO_2$ was transformed into the anatase structure at $350^{\circ}C$, rutile structure at $550^{\circ}C$ and further into the two structure at $450^{\circ}C$. With increasing thickness up to $18{\mu}m$ and sintering temperature up to $450^{\circ}C$, respectively, the irradiance rate increased in the range of 9~26 percent and 2.80~5.10 percent. Whereas a further increase to $24{\mu}m$ and $550^{\circ}C$, the irradiance rate decrease in the range of 4~11 percent and 30~47 percent. The conversion efficiency increased in the range of 2.80~5.01 and 3.03~5.01 with increasing thickness up to $18{\mu}m$ and sintering temperature up to $450^{\circ}C$. By contrast, increase to $24{\mu}m$ and $550^{\circ}C$, the conversion efficiency decreased in the range of 3.31~5.01 and 2.80~3.89, respectively. The DSSC that thickness of $TiO_2$ were $18{\mu}m$ and sintered at $450^{\circ}C$ exhibited the most excellent characteristics, in which open-circuit voltage, short-circuit current, Fill Factor and conversion efficiency are 0.69 V, $11.4mA/cm^2$, 0.64 and 5.01%, respectively.

• Journal of Nutrition and Health
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• v.3 no.3
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• pp.149-159
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• 1970

This study is to investigate the status of anemia, especially iron deficiency anemia among pre-school children in rural area in Korea. The survey was conducted in Sang-dae Ri, Yusong Myon, Daedok Gun, Chung Chong Nam-Do from July 30 th to August 12th, 1968. The measurements were done of height, weight, hematologist and biochemical levels on ninety-two pre-school children, 47 male, and 45 female, one to six years of age. Hemoglobin was determined by the method of cyanmethemoglobin and hematocrit by micro hematocrit centrifuge. The determination of serum iron, iron-binding capacity was done by the method of Ramsay using bathophenanthroline and the serum albumin was determined by Biuret Reaction. The results of this study are as follows: 1) 54.4 percent of the pre-school children weighed less than 90 percent of the Korean General Standard Weight level. 2) The average hemoglobin level was $11.0{\pm}1.57gm/100ml$, 38.0 percent of the children were anemic with less than 1.0gm/100ml. Of the anemic children 60 percent were below the Korean General Standard Weight level. 3) 27.5 percent of the pre-school children were found to have below 32 percent of a hematocrit values and 28.0 percent showed less than 33 percent in M.C.H.C. These results showed that the incidence of hypochromic anemia in these pre-school children was high. 4) 37.9 percent of these children had a serum iron level less than $50{\mu}g/100ml\;and\;31.0\;percent\;had\;a\;TIBC\;above\;400{\mu}g$ while 48.3 percent showed a transferrin saturation lower than 15 percent. On the basis of these findings, it is concluded than the cause of this anemia was iron deficiency. 5) In this group there was a little evidence of low total serum protein levels. However, 10.4 percent of the children had a deficient serum albumin level, below 2.80 gm/100ml while 51.7 percent had a low level, less than 3.50gm/100ml, and 34.5 percent of the children had a low level of TIBC, less than $350{\mu}g/100ml$, and considering these facts, it is suggested that some of the anemias have a multiple causes through protein deficiency and repeated chronic infection apart from iron deficiency.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.794-799
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• 2003

A study was conducted on 2102 records of 808 crossbred cows of various genetic groups maintained under 'All India Coordinated Research Project on Cattle' at C C S Haryana Agricultural University, Hisar, over 25 years period (1968-1993) with an objective to assess and compare the amount of percent improvement and heterotic effect for different performance traits in various genetic groups produced under this programme. Survivability sharply and significantly declined from 1/2 to $3/4^th$ bred and further from $3/4^th$ to inter-se bred. This may be due to periodic and management differences in addition to the higher level of exotic inheritance and decreased heterotic effect over the filial generations. Jersey and Holstein Friesian crosses among 1/2 breds and their 50% inheritance among $3/4^th$ and inter-se breds had highest improvement and heterosis in reproduction and production traits respectively. Among inter se bred genetic groups, BFH (I) had no recombination loss in SP and CI, while FJH (I), JFH (I) and FBH (I) had on recombination loss in AFC, LY, LL and PE. The crossbreeding of zebu cows with exotic breeds brings about spectacular improvement in comparison to the performance of zebu breed, while conventional selection over several generation would lead to only modest improvement. In addition to additive effect, there was sufficient heterosis in Jersey crosses for reproduction and Holstein Friesian crosses for production performance. Three breed crosses with exotic inheritance between 50 and 75 percent incorporating genes (25 to 50%) from both of these breeds is the best combination for stabilization.

• Journal of the Korean Chemical Society
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• v.20 no.6
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• pp.525-532
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• 1976

Anionic polymerization of 2-pyrrolidone and ${\varepsilon}$-Caprolactam via $CO_2/KOH catalysis was attempted in order to find reaction condition and physical properties of polymers. In case of polymerization of 2-pyrrolidone, the yield of conversion was increased when the concentration of potassium hydroxide was reached above 8 mole percent. The optimum of CO_2/KOH$ mole ratio was 0.45. It was also found that the polymerization was taking place at moderate temperature which was around $50^{\circ}C$. With regard to polymerization of-caprolactam, the yield of conversion was relatively low at $80^{\circ}C$ to $90^{\circ}C$and higher yield of conversion was obtained at higher temperature between $150^{\circ}C$ to $180^{\circ}C$ regardless of $CO_2/KOH mole ratio. The inherent viscosity of nylon 4 and nylon 6 which was made via CO_2/KOH$ catalysis was measured. The observed inherent viscosity was between 2.0 to 5.0.

• Clinical and Experimental Pediatrics
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• v.48 no.6
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• pp.606-613
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• 2005

Purpose : Acute poststreptococcal glomerulonephritis(APSGN) is a common form of glomerulonephritis in children. Most patients recover completely after the acute phase but a few patients have acute complications or progress to chronic renal disease. In recent years, the frequency of APSGN has been was decreasing but is still common in children. So we studied the clinical characteristics of APSGN from 1994 to 2003 and compared it with past studies. Methods : We studied 105 patients who were diagnosed with APSGN in the Department of Pediatrics, Asan Medical Center between January 1994 and December 2003, with a retrospective chart review. Results : The mean age was $8.5{\pm}2.6$ years. The male to female ratio was 2 : 1. Average annual incidence was $10.5{\pm}4.9$ most patients(60.0 percent) occurred from October to January. Edema was seen in 82 cases(78.1 percent), gross hematuria in 70 cases(66.7 percent), hypertension in 50 cases (47.6 percent) and oliguria in 22 cases(20.9 percent). Microscopic hematuria was seen in 105 cases (100 percent), positive ASO in 99 cases(94.2 percent), proteinuria in 67 cases(63.8 percent) and azotemia in 38 cases(36.2 percent). Serum complement 3(C3) level decreased in 96 cases and returned to normal within eight weeks in 70 patients(75.3 percent). Kidney biopsy was carried out in 22 cases. Most acute symptoms subsided within 2 weeks of onset. Conclusion : We concluded that there was no significant difference between clinical features of recent and past APSGN in children, and short term prognoses were excellent.

• Korean Journal of Microbiology
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• v.9 no.2
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• pp.55-60
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• 1971

Among 50 yeasts of red pepper paste isolated and identified in the previous report, 12 strains of yeast which possess osmophilic and non-film characteristics were examined their growth rates and alcohol fermentation ability in red pepper medium. 5 strains of yeast possessing powerful growth rates and excellent alcohol fermentation ability were selected as excellent yeasts in this experiment. And their cultural conditions, salt resistance and red pepper concentration upon the growth were examined in this report. The results obtained were as follows ; 1) Among 12 strains of yeast, Saccharomyces cerevisiae group II(strain $D_1$), Saccharomyces oviformis($D_2$), Saccharomyces steineri($M_3$), Saccharomyces rouxii($D_9$) and Saccharomyces mellis($G_8$) were selected as excellent yeasts. 2) Among 5 strains of yeast selected, the strain $D_1$ and $D_2$showed the best alcohol fermentation ability and the best fermentative flavour. 3) The optimum temperature for growth of the strain $D_1$ and $D_2$ was $25^{\circ}C$$M_3$, $D_9$ and $G_8$ $30^{\circ}C$$D_1$ and $D_2$ was $62^{\circ}C$$M_3$,$D_9$ and $G_8$ ws 60.deg.C with treatment for 10 minutes. 4) The optimum pH for growth of all strains was around 5.0. 5) The strain $D_1$ and $M_3$were grown exceedingly well on the emdia containing 3 percent of NaCl and $D_2$,$D_9$ and $G_8$ on the media containing 6 percent of NaCl. 6) In the case of 5 percent of red pepper liquor added 5 percent of glucose was more nutritional than in the case of 5 percent glucose only. However, the growth rates of yeasts were restrained by the increase of red pepper concentration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.122-133
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• 1975

In recent years, farmers have substituted urea for ammonium sulfate as nitrogen fertilizer in their crop production. Since crops can not take urea itself directly as it is, we attempted to determine the amount of decomposition of urea in soil. It was observed that 25 percent of urea which had initially mixed with soil was decomposed in 10 days at 15$^{\circ}C$ and 80 percent in 2 days at $25^{\circ}C$. Therefore, it was considered that large amount of urea could be lost in cool season and cool areas. In the other experiment, ammonium sulfate, as a source of sulfur, was so mixed with urea that the ratio of sulfur to nitrogen would be 15 percent. Small amount of dolomite was also added to this mixture and the resulting fertilizer was applied on the rice plants. Eight percent of yield increase was obtained together with the increased protein content in brown rice.

• Journal of the Korean Wood Science and Technology
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• v.22 no.3
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• pp.32-38
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• 1994

The methods in wood processing are so limited at present that a scope of its utilization is restricted. This often makes wood itself less valuable as a material comparing with other materials, that is, plastics, metals, and glass. Such differences are due to a lack of plasticity in wood, i.e. it cannot be melted, dissolved, or softened sufficiently for molding. However, once plastic properties are added to wood, it becomes more useful material. This further broadens the method in wood processing to a variety of fields. In this way, wooden material which is limited in use can be modified into a high quality product with additional value. Furthermore, utilization of wastes from wood, for example, would be made viable. In this study, thermoplasticization was carried out by benzylation of wood(sawdust). Various factors those affect the reaction were tested to produce benzylated wood with different degrees of substitution. Reaction temperature and time were the quite important factors. Optimum reaction temperature was 110$^{\circ}C$, and weight percent gains(WPG) of final products increased gradually with the increase of reaction time. The pretreatment (or preswelling) of wood with alkaline solution had a critical effect on benzylation. and the concentration of alkaline solution should be above 30% to obtain high weight percent gain. The thermal flow temperature of the benzylated wood decreased with the increase in weight percent gain, that of 80% weight percent gain is about 200$^{\circ}C$.

• Transactions of the Korean hydrogen and new energy society
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• v.8 no.2
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• pp.91-97
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• 1997

The goals of this research are to understand the $NO_x$ emission in direct injected diesel engine with premixed hydrogen fuel. Hydrogen fuel was supplied into the test engine through the intake pipe. Amount of hydrogen-supplemented fuel was 70 percent basis heating value of the total fuel. The effects of intake air temperature on $NO_x$ emission were studied. The intake air temperature was controlled by flow rate of liquid nitrogen. The major conclusions of this work include : (i) the tested engine was run without backfire under 70 percent hydrogen fuel supplemented. (ii) radicals of nitrogen gas in the intake pipe were increased by 30 percent and cylinder gas temperature was decreased by 24 percent as the intake air temperature were changed from $23^{\circ}C$ to $0^{\circ}C$ ; and (iii) $NO_x$ emission per unit heating value of supplied fuel was decreased by 45 percent with same decrease of intake air temperature.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.327-333
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• 2000

This experiment was conducted to determine the effect of priming duration and temperature on germinability of vegetable seeds. Priming chemicals were -0.50 MPa PEG 8000 for carrot, 50 mM $K_3PO_4$ for lettuce, 200 mM $KH_2PO_4$ for onion, and 100 mM $Ca(NO_3)_2$ for Welsh onion seeds. Priming temperature varied from $10^{\circ}C$ to $25^{\circ}C$, and priming duration varied from 12 hours to 5 days depending on crops. Percent germination of carrot seeds was significantly affected by the seed treatment and priming temperature. Priming at $20^{\circ}C$ for 3 days was most effective in reducing number of days to attain 50% of the final germination percentage (T50) and mean number of days to germination (MDG). Radicle protrusion in the priming solution was as high as 14% when primed at $20^{\circ}C$ for 4 days. Percent germination of lettuce seeds was affected significantly by the seed treatment and priming duration. Priming lettuce seeds at $20^{\circ}C$ for 2 days increased percent germination and shortened T50 and MDG without radicle protrusion. Percent germination of onion seeds was affected significantly by the seed treatment, priming duration, and temperature. Priming at either $10^{\circ}C$ or $15^{\circ}C$ for 3, 4, or 5 days did not affect percent germination of onion seeds, but was effective in reducing T50 and MDG. Decline in percent germination of onion seeds was precipitous as the length of priming duration increased from 3 to 5 days. Percent germination of welsh onion seeds was not affected by the priming duration and temperature. Priming at $15^{\circ}C$ for 4 days was most effective in reducing T50 and MDG, increased in duration of priming at $15^{\circ}C$ or $20^{\circ}C$ increased radicle protrusion.