• 한국환경생태학회지
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• 제30권4호
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• pp.793-799
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• 2016

본 연구는 도심지 공원 내 식재된 버즘나무와 느릅나무를 대상으로 수관 내부의 온도, 풍량, 풍속 등 미기후 인자간의 상호관계를 규명하는데 그 목적이 있다. 현장조사는 여름철, 8월 한 달간 오전 09시부터 오후 06시까지 1시간 간격으로 측정하였다. 미기후 인자 측정 항목은 광량자센서(PAR Quantum Sensor SKP215), 정밀온도계측기(Pt1000-Sensor), 풍량풍속계(1467 G4 & HG4)를 이용하여 온도, 광량, 풍량 및 풍속 데이터를 수집하였다. 분석 결과, 버즘나무와 느릅나무는 두 종 모두 외부 온도에 비해 수관 내부에서 냉각효과가 있음이 입증되었다. 수관 내부의 냉각효과는 대기 중의 풍량과 풍속이 있을 때 더 효과적이었다. 바람이 있을 때, 버즘나무는 풍량에 의해 수관 내부의 온도가 더 낮아지며, 느릅나무는 풍속에 의해 수관 내부의 온도가 더 낮아지는 것으로 확인되었다. 바람이 없을 때, 두 종간 수관 내 평균온도 변화는 평균적으로 느릅나무가 $-0.9^{\circ}C$, 버즘나무가 $-0.958^{\circ}C$로 버즘나무가 느릅나무보다 식재 공간 내 온도를 낮추는데 비교적 더 효과적이었다. 본 연구는 도심 내 수목이 종별로 미기후에 미치는 영향에 차이가 있으며 또한, 수목의 미기후 형성에 영향을 미치는 인자들이 수종별로 다를 수 있음을 밝혔다는데서 의의가 있다. 향후 활엽교목 이외에 상록수, 관목류 등 다양한 수종 등에 대한 후속 연구가 필요하며, 이를 통해 도시 녹지 공간 내 미기후 조절에 효과적인 조경수를 보급하는데 기여할 것으로 사료된다.

• 대한소아치과학회지
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• 제31권2호
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• pp.267-272
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• 2004

본 증례에서는 치아외상으로 치관-치근 파절된 미성숙 영구치의 치료에 대해 서술하고자 한다. 7세 환아의 상악 좌측 중절 치의 치아 파절선이 치은연하로 치아장축을 따라 치아전체의 1/2까지 연장되어 있었다. 수직적 치관-치근 파절된 치아에서 그 예후는 불량하며 발치가 일반적인 처치이나 성장기 아동에서 상악중절치의 발치는 치조골 흡수, 심미적 문제, 발음문제 등 여러 합병증을 초래한다. 치은연하로 치관-치근 파절된 치아의 치료 방법으로 치은연상만 수복하는 방법과 치은판막을 형성하여 수복하여 주는 방법, 교정력을 이용하여 정출시키는 방법과 수술로써 발치하여 정출시키는 방법 등이 있다. 본 증례에서는 치아를 의도적으로 발치한 후 접착용 레진 시스템을 이용하여 분리된 치아 파절편을 부착한 후 재식하였다. 1년 동안 관찰한 결과 현재 특이한 임상적 증상은 없으며 심미적으로도 만족할 만하다. 접착용 레진 시스템의 개발과 함께 본 술식은 외상을 많이 받는 혼합 치열기 아동에서 치관-치근 파절된 미성숙 영구치의 한 치료법으로 고려할 수 있다고 생각되어 이에 보고하는 바이다.

• Bulletin of the Korean Chemical Society
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• 제15권7호
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• pp.559-563
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• 1994

Glycosylation of benzoylated glycosyl halides of glucose, galactose and mannose with potassium p-nitrophenoxide and 18-crown-6 complex in chloroform resulted in the stereospecific formation of 1,2-trans p-nitrophenyl glycopyranosides in good yields. The same reaction with benzylated mannopyranosyl chloride gave the ${\alpha}-and\;{\beta}-p-nitrophenyl$ mannopyranosides in 3 : 1 ratio. However, acetylated 2-azido-altropyranosyl chloride gave ${\beta}-p-nitrophenyl$ altropyranoside only.

• International Journal of Oral Biology
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• 제43권4호
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• pp.177-183
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• 2018

The objective of this study was to examine the expression pattern of Kelch-like ECH-associated protein 1 (Keap1) in the maxillary $2^{nd}$ molar germs of rats. We used the maxillary $2^{nd}$ molar germs in rats' pup at postnatal day 3 (bell stage), 6 (crown formation stage) and 9 (root formation stage). The investigation on mRNA and protein levels were done using reverse transcription - polymerase chain reaction and western blot. Localization of Keap 1 in the maxillary $2^{nd}$ molar germs were revealed through immunofluorescence staining. Keap1 from the maxillary 2nd molar germs were mostly manifested on postnatal day 3 and dramatically decreased on postnatal day 6 and 9 at mRNA and protein levels, while amelogenin and ameloblastin increased during the development of maxillary 2nd molar germs. During immunofluorescence analysis, the strong immunoreactivity against Keap1 was detected in the apical side of ameloblasts at the presecretory and secretory stages. However, Keap1 expression was hardly observed in the ameloblasts at the maturation stage. These results shows that Keap1 is strongly expressed in the presecretory and secretory ameloblasts of amelogenesis, and suggest that Keap1 may be a crucial molecule for the regulatory mechanisms tasked with the formation of enamel layer.

• 분석과학
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• 제13권4호
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• pp.466-473
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• 2000

용매고분자막 상에 칼륨과 다양한 나트륨이온 선택성 중성 운반체의 착물형성상수(${\beta}_{MLn}$)를 고분자막형 광센서(optode)와 이온선택성 전극(ISE)을 이용하여 결정하였다. 수소이온선택성 발색물질(chromoionophore : ETH 5294)에 가장 널리 쓰이는 나트륨 이온선택성 물질들(4-tert-butylcalix[4]arenetetraacetic acid tetraethyl ester, ETH 2120, bis[(12-crown-4)methyl] dodecyl-methylmalonate 및 monensin methyl ester)을 첨가한 막과 첨가하지 않은 막으로 두 가지 다른 조성의 PVC 막을 제작하여, 일정 pH(0.05 M Tris-HCl, pH7.2)에서 알칼리금속 양이온(나트륨과 칼륨)의 농도 변화에 따른 광학적 감응을 측정하고, 또 일정한 알칼리금속 양이온 농도(0.1M)에서 pH변화에 따른 광학적 감응을 측정하였다. 또한 유사한 조성의 막을 각각 재래식 전극체에 장착하고 일정한 알칼리금속 양이온의 농도(0.1M)에서 pH 변화에 따른 전위치를 측정하였다. 양이온/수소이온의 활동도 비($a_{M^+}/a_{H^+}$)와 상대흡광도로 도시한 광센서 감응곡선과 수소이온농도에 따른 전위차 감응곡선으로부터 나트륨 이온선택성 리간드들의 착물형성상수를 결정하였다. 목적이온과 방해이온에 대한 착물형성상수들의 비로부터 얻어진 값은 실험적으로 얻어진 이온선택성 전극의 선택계수와 근접함을 확인하였다.

• Journal of Oral Medicine and Pain
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• 제10권1호
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• pp.53-62
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• 1985

This study was undertaken to obtain the data for age determination following the calcification degree of the third molar in the point of forensic odontology. The orthopantomograms of 1399 male and 2517 female ranging from 7 to 22 years of age were studied. The developmental state of the third molar was divided into 12 stages following the calcification degree and the mean ages of stage was obtained and statistically analyzed. The results were as follows : 1. There was remarkable correlation between the development of the third molar and age. 2. There was no significant developmental difference between the right and left third molar. 3. The development of the third molar presents difference between the male and female in the crown formation stages, but it was retarded in female than male in the root formation stages. 4. At the age under 20 years, we can determine the age within the range of * 2 years by means of orthopantomogram.

• 한국자동차공학회논문집
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• 제15권5호
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• pp.153-159
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• 2007

The performance of a direct-injection type diesel engine often depends on the strength of air flow in the cylinder, shape of combustion chamber, the number of nozzle holes, etc. This is of course because the process of combustion in the cylinder was affected by the mixture formation process. In the present paper, high speed photography was employed to investigate the effectiveness of holes penetrated from the bottom of cavity wall to piston crown for some more useful utilization of air. The holes would function to improve mixing of fuel and air by the increase of air flow in the cylinder. The results obtained are summarized as follows, (1) Activated first of the combustion by shorten of ignition timing and rapid flame propagation (2) Raised the combustion peak pressure, more close to TDC the formation timing of peak pressure.

• 치과방사선
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• 제1권1호
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• pp.13-19
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• 1971

The author has studied on 910 roentgenograms of lower second molars, which were taken by intraoral technic, and obtained the following results. 1. The development of crown of lower second molars was completed 8.25 years. 2. The formation of mesial and distal roots in full length on lower second molars was completed as follows: a. mesial roots 15. 07 years b. distal roots 15. 53 years 3. The formation of apical foramina of mesial and distal roots of lower second molars was closured as follows: a. apical foramen of mesial root 18.00 years b. apical foramen of distal root 18.79 years 4. As a general rule, the mesial roots were developed more earlier than distal roots.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2568-2573
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• 2008

A drop impact on the liquid film/pool generates several phenomena such as the drop floating, bouncing, formation of vortex ring, jetting, bubble entrapment and splashing. These phenomena depend on the impact velocity, the drop size, the drop properties and the liquid film/pool thickness. These parameters can be summarized by four main dimensionless parameters; Weber number, Ohnesorge number, Froude number and non-dimensional film/pool thickness. In the present study, the phenomena of the splashing and bubble entrapment due to the drop impact on the liquid film/pool were numerically investigated by using a Level Set method for the sharp interface tracking of two distinct phases. After the drop impact, the splashing phenomena with the crown formation and spreading were predicted. Under the specific conditions, the bubble entrapment at the base of the collapsing cavity due to the drop impact was also observed. The numerical results were compared to the available experimental data showing good agreements.

• Journal of Plant Biology
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• 제39권3호
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• pp.179-184
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• 1996

The purpose of this study is to obtain the most efficient combination of Agrobacterium tumefaciens strains and Ti plasmids for the construction of dicotyledonous plant vector system. Ti plasmid-curing A. tumefaciens A136 and KU12C3 were transformed with four kinds of Ti plasmids, pTiBo542, pTiA6, pTiKU12 and pTiAch5, respectively. The stems of 28 species of dicotyledonous plants were then inoculated with these transformants and examined for crown gall formation. The different combination of A. tumefaciens strains and Ti plasmids showed quite a difference in terms of the crown gall formation. Agrobacterium strins A136 and KU12C3 have a same plant host range in case that both strains harour the same kind of Ti plasmid, pTiBo542 or pTiAch5. However, the above-mentioned both strains have quite different host range in the event of containing the same Ti plasmid, pTiKU12 or pTiA6. In case that KU12C3 contains pTiA6 or pTiKU12, this strain has a wider plant host range than A136. The plant host range of pTiBo542 is the widest, followed by pTiA6, pTiKU12 and pTiAch5. Twelve plants among 28 tested plants are not transformed by any virulent Agrobacterium strains used in this study. In conclusion, A. tumefaciens KU12C3 and A136 harboring pTiBo542 showed the widest host range for transforming dicotyledonous plants. Also, it was acertained that the host range of Ti plasmids is affected by chromosomal level.