• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.257-259
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• 1987

The photoelectronic properties of CdTe films sintered with various amounts of $CdCl_2$ and $CuCl_2$ have been investigated by measurements of dark electrical resistivity, photocurrent, thermoelectric power, optical transmission and by observation of microstructure. The grain size and optical transmission of sintered CdTe films increase with increasing amount of $CdCl_2$ indicating that $CdCl_2$ acts as a sintering aid. The photoconductivity gain(A-$cm^2/W$) increases and resistivity($\Omega$-cm) decreases with increasing amount of $CuCl_2$ up to 100ppm due to the occurance of Cu-doping during sintering. The dark resistivity could be reduced farther by post heat treatments. The dark resistivity was still high($10^3{\Omega}$-cm) so that the accurate determination of the hole concentration by Hall measurement or by thermoelectric power measurement was not possible. From the analysis of electrical activation energy, however it can be concluded that the hole concentration is less than $10^{14}/cm^3$ and all grains are depleted of carrier by the trapping centers at grain boundaries.

• 약학회지
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• 제45권1호
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• pp.85-92
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• 2001

Nitric oxide is a tonically produced vasodilator that maintains blood pressure in the normal animal. The chronic inhibition of nitric oxide synthase (NOS) elicits the hypertension in rats. However, the mechanism of hypertension induced by chronic inhibition of NOS is not clear. Thus, to clarify the mechanism of the occurance of hypertension, the changes in $\alpha$-adrenergic systems in rats treated with NOS inhibitors for 21 days were examined. Chronic administration of L-NAME significantly increased in the basal blood pressure, but chronic administration of 7-nitroindazole did not. Phenylephrine and G-protein stimulator elicited the more potent contraction in the aorta of the L-NAME-induced hypertensive rats. However when the contractile responses by phenylephrine and G-protein stimulator were calculated the proportion to the contraction by 25 mM KCL, there was no difference between the vehicle-treated rats and the L-NAME-treated rats. The density of $\alpha$-adrenergic receptors in aortic tissue was not changed by the chronic inhibition of NOS. These results suggest that hypertension induced by chronic inhibition of NOS is due to the inhibition of eNOS and the increased responses to the adrenergic drugs are due to the changes of the intracellular contactile mechanism of aortic tissue rather than the changes of receptor density.

• 대한수의학회지
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• 제39권6호
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• pp.1099-1105
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• 1999

Reproductive failures, such as abortions were occured among dogs in a large kennel in Chonnam area April in 1994. After an initial positive result by the 2 mercaptoethal rapid slide agglutination test(2ME-RSAT) to Brucella canis on five sera, additional specimens from all dogs in the population were tested. The blood cultures and 3 following serological tests (2ME-RSAT, TAT, AGID) performed on all samples on the basis of surveys, the following results were obtained. 1. Thirty three of 62 dogs were seropositive. 2. Twenty blood samples from 33 dogs were cultured, all of the isolates were identified as B canis. 3. Although there was not siginificant difference in sex, age and breed of the cause brucellosis dectected, abortions was occured late in gestation stage.

• 대한기계학회논문집B
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• 제22권9호
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• pp.1247-1254
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• 1998

The vaneless diffusers are widely used in industrial centrifugal compressors which are required to operate within a wide flow range. When very high pressure gases are handled by centrifugal compressor. rotating stall is a serious problem because of the occurance of large aerodynamic exciting forces. Rotating stall mostly often occurs in the impellers but it can occur in vaneless diffusers as well. In this experimental study, the rotating stall in vaneless diffuser with radial type centrifugal impeller was measured by changing the flow rate with I-type, X-type hotwire. As the result, it was cleared which type of rotating stall of the impeller stall would occur and how many stall cells would appear relating with the flow rate. As the flow rate reduced, the propagation speed of rotating stall was reduced. But the stall cell number unchanged with respect to the flow rate.

• 치과방사선
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• 제15권1호
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• pp.67-74
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• 1985

The incidence and associated dental abnormalities of taurodontism were studied radiographically (panoramic view) in 1895 patients of deciduous dentition and 2167 patients of permanent dentition who had visited to the Department of Oral Radiology, Kyung Hee University in Korea. The obtained results were as follows: 1. The prevalence of taurodontism was 3.59% in the deciduous dentition group, and 1.8% in the permanent dentition group. 2. There was no definite sex difference in the deciduous dentition, and the permanent dentition group. The type of mesotaurodontism was predominent in the deciduous dentition group, and hypotaurodontism in the permanent dentition group. 4. The vast majority of this abnormalities had occurred in the mandibular 1st deciduous molar in the deciduous dentition group, and mandibular 2nd permanent molar in the permanent dentition group. 5. Of the cases with taurodontism, the deciduous dentition group revealed 95.6% bilaterally, and 82% bilaterally in the permanent dentition group. 6. Multiple teeth occurance, not single tooth only, were involved in 98.5% of the cases in the deciduous dentition group, and 82% in the permanent dentition group.

• 치과방사선
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• 제12권1호
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• pp.21-26
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• 1982

A radiologic study of 139 dentigerous cysts (128 patients) indicated the followings: 1. There was higher incidence in males (62.99%) than in females (37.01%). The most common age group was 11-20 years and the average age was 23.6 years. 2. The most common clinical symptoms was swelling of the jaws (49 cases, 33.09%), and no symptoms was presented in 26 cases (18.71%). 3. Dentigerous cysts were found to be slightly more common in the maxilla (53.24%) than in the mandible (46.76%) and there was almost no difference in occurance between right and left side. The maxillary supernumerary tooth was the most frequent site of the dentigerous cyst and no dentigerous cyst was found to be related to a deciduous tooth. 4. The most common radiographic findings was root resorption of the adjacent teeth (33.09%), and the central dentigerous cysts were 78 cases (56.12%), the lateral dentigerous cysts were 61 cases (43.88%). 5. The increased radiolucency at the crown portion of the tooth in a cystic cavity was seen in 44 cases (31.65%), and a case of dentigerous cyst was found in a edentulous patient, and 16 cases of multiple dentigerous cysts were found in 5 patients. 6. The ameloblastic changes in 8 cases, the keratinization of the cyst wall in 2 cases, and a case of epidermoid carcinoma were confirmed microscopically.

• 한국미생물·생명공학회지
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• 제16권6호
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• pp.463-467
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• 1988

L. casei YIT9018에서 자연적으로 발생하는 Lac$^-$ mutant의 발생빈도와 이러한 변이주의 특성을 검토하였다. 보존균주로부터 spontaneous Lac$^-$ mutant의 발생은 MRS 배지에서 0.5%, 10% 환원탈지유에서 0.29%, pure Lac$^+$ colony로부터의 발생은 MRS 배지에서 0.25%, 10% 환원탈지유에서 0.1%의 빈도로 나타났다. 분리된 spontaneous mutant는 대부분이 Lac$^-$ mutant였고 가끔 Lac-Gal-도 나타났다. Lac$^-$ Gal$^+$ mutant는 배양 4일째부터 partial revertant가 출현하였으나 Lac$^-$ Gal$^-$는 전혀 나타나지 않았으며 Lac$^-$ mutant는 wild type보다 우유를 응고시키는데 더 많은 시간을 요하였다.

• 상하수도학회지
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• 제11권4호
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• pp.35-42
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• 1997

Recently fluoridation has often been considered as a method to maintain the concentration of fluoride in the drinking water at level adequate to be able to help protect children having decayed teeth. The benefits of fluoridation can be verified to compare the occurance rates of decayed tooth in the areas fluoridated and not fluoridated. Jainhae and Chongju have already fluoridaed the drinking water, and it was known that fluoridation could protect tooth-decaying effectively. The reduction rate of decayed teeth was estimated to be about 50~60 per cent. In the present study, a questionary survey to about sixty four hundred inhabitants of Taejon was carried out to grasp the opinions of citizens for fluoridation. According to the results, 75 per cent of the respondents agreed to the fluoridation. About 49 per cent and 44 per cent of them wanted that the fluoridation should be enforced after a questionary survey and after the decision of a specialist group in the institutes concerned respectively. About 71 per cent of them agreed to 5 per cent-rising of water fee for the fluoridation. The anual cost reguired for fluoridation in a large city was estimated to be about 500 won per capital therefore its economic effect is very large.

• 대한수의학회지
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• 제36권4호
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• pp.1007-1012
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• 1996

The purpose of the survey was to understand the field situation on the occurrence of enteric diseases in poultry farms in Korea. During the period from January of 1991 to December, 1992, 279(35.8%) out of 779 farms surveyed experienced the cases of enteritis in their chickens. The farms with diarrheal problems consisted of 157(45.1%) of 348 broiler flock, 28(32.6%) of 86 breeder flock, and 94(27.2%) of 345 layer flock. The main diseases causing enteritis were frequently appeared as infectious bursal disease(27.3%), colibacillosis(22.6%), and coccidiosis(8.6%). Necrotic enteritis(NE) in chicken occurred in 21 farms(2.7%) among 779 farms examined. The outbreaks of NE were divided 4.7% in breeders, 4.0% in broilers, and 0.9% in layers, respectively. NE occurred mainly in the age(71.4%) of 20~30 days and the mortality was varying from 1.4% to 10.0% for broilers, 3.0% for layers and 0.8% for breeders. Seasonal prevalence of NE showed the highest as 52.4% in summer and followed by 33.3% in autumn, 9.5% in spring and 4.5% in winter.

• 한국유기농업학회지
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• 제3권1호
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• pp.23-42
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• 1994

This paper studied earthworm populations in fields under practical cultivation in the Eastern Harzforeland (Germany). The examined sites differed insignificantly in their climatic and soil conditions. The examination was a comparison between a field and a narrow edge or meadow. A combination of Oktett method and handsortin was used. The five different habitates seven earthworm species were discoverd. The most frequently foundd were A. rosea, A. caliginosa, and A. chlorotica. There were clear differences in species between the habitates of each site. Generally the edge or the meadow contained one (Zoeberitz) or two (Zscherben) more species than the field. The composition of species differed between 1990 and 1992. In the dry Autumn of 1991 there were less species found at both sites. The occurance of earthworm species depends on the weather. Moisture influencing similiarity of abundance and bio-mass were recorded in three out of four habitates. Starting on a high level in Autumn 1990 the abundance as well as biomass decreased until Autumn 1991 and increased the following year. The number from 1990 were never reached again during the examination. One year of normal precipita-tion was not enough to return the population to the beginning level. Great differences in the number of earthworms between the compared habitats suggest that the edges and meadows are a potential immigration source into a field which is poor on earthworms. Structrues of distribution near the edge refer to a migration from a high populated edge into an almost empty field.