• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.2
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• pp.139-147
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• 1998

This study has been performed to evaluate the relationship between the remained mineral components in a decalcified bone matrix and an ectopic bone formation efficiency. The freezed rat diaphyseal cortical bones measuring 0.5cm in length were demineralized in heated 0.6N HCl at $60^{\circ}C$ for 5, 10, 15, 20, 25, 30, 35, 40 minutes, respectively, using a controlled heat ultrasonic cleaner. Each 1cc of decalcifying solution taken during decalcification procedure was used to calculate calcium content using calcium dignostics kit under 600nm of spectrophotomer. After decalcification, each specimen was also weighed. Then each prepared specimen was implanted into the dorsal pouch of 24 Sprague-Dawley rats divided into 8 groups by time course. The implants were harvested at 1, 2, and 3 weeks and prepared for routine H-E stain specimens to evaluate osteogenic activity. The results are as follows: 1. There was statistical significant difference in change of calcium concentration up to demineralization of 30 minutes and each allogenic bones decalcifed up to 20 minutes revealed 99.65% of decalcification in average. 2. There was statistical significant difference in change of weight in demineralized allogenic bone up to 20 minutes treatment but, no significant change was noted after that time. 3. The histologic analysis revealed active ectopic bone formation in the implanted allografts demineralized for 20, 25, 30 minutes, respectively. However, the other groups of allografts showed relatively poor osteoinductive activity. These findings suggest that complete decalcification with a minimized degeneration of collagen matrix is necessary to induce maximal osteogenesis by decalcified bone allograft.

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.862-870
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• 1994

$Pb(NO_3)_2$, $Mg(NO_3)_2$ and $NbCl_5$ were used as starting materials and made into solutions. For $Pb(Mg_{1/3}Nb_{2/3})O_3$ composition, each solution measured was mixed and heated to $70^{\circ}C$ to resolved $PbCl_2$ precipitated at lower temperature coprecipitates were formed by adding oxine and ammonia gas under pH ranging 8 to 10, and the prepared coprecipitates were filtered and washed by distilled water. The $Pb(Mg_{1/3}Nb_{2/3})O_3$ powders were synthesized by calcination of coprecipitates at the temperature range of $700^{\circ}C$ to $1000^{\circ}C$, for 5hr. The average particle size of the synthesized powders showing spherical shape was $0.3{{\mu}m}$. The powders were formed to make pellets under pressure of $2000Kg/cm^2$, and the formed pellets were sintered at the temperature range of 1100 to $1200^{\circ}C$, for 5hr. The speciman sintered at $1200^{\circ}C$ showed theoretical density of 97.4%, dielectric constatnt of 17000 at 1kHz, and dielectric loss of 0.02% at 1kHz

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.206-211
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• 2004

It is very important to minimize the acid value of oil in the oil and fat industry, because acid value of oil products are a indicator quality. This study was performed to investigate change of moisture content, acid value and free fatty acid content by drying condition such as drying method, temperature and drying time on steamed duck egg york. Also, change of fatty acid composition by acid value. The acid values, moisture contents and free fatty acid contents were showed comparatively lower value by spray drying and freeze drying than by steam drying. but difference that keep in mind between each drying method was not looked. Whereas moisture content, acid value and free fatty acid content of effect of drying temperature reaches in lowest value. also, did not show change until dry 12hours reaching to lowest value by 3.1, 3.0％ and 0.98％ after dry 9hours both moisture content, acid value and free fatty acid content. Also, acid value increase, free fatty acid was increased, where unsaturated fatty acid showed that decrease rapidly.

• Korean Journal of Microbiology
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• v.31 no.2
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• pp.141-147
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• 1993

Plasmid DNAs were detected from the mitochondrial fraction of four strains of whiterot fungus, Pleurotus ostreatus. The size of the plasmids were 10.2 and 7.2 kb in strain NFFA 2, 10.2 kb in NFFA 4001, 11.2 kb in NFFA 4501, and 10.2 and 11.2 kb in KFCC 11635. The two strains,NFFA 2ml and NFFA 2m2, which are mutant derivatives of NFFA 2, did not contain any plasmids. The cleavage by proteinase K indicated that these plasmids have DNA ends associated with proteins. In digestion with proteinase K all the plasm ids remained resistant to lambda exonuclease which hydrolyzes DNA from 5' ends and were sensitive to exonuclease III which hydrolyzes DNA from 3' ends. This suggests that the plasmids are linear double-stranded DNA and the terminal proteins are covalently linked to 5' ends of plasm ids. In order to find relationship between these plasmids, hybridization of plasm ids by each separate plasmid DNA was done. The result indicated that the plasmids can be classified into at least 3 groups. Plasmids of group I were present in all the P ostreatus. More mitochondrial plasmids were detected in P cornucopiae. P ,florida, P pulmonarius, P sajor-caju, and P spodoleucus. The size of plasmids ranged between 7.2 kb and 14 kb. All the species except P cornucopiae contained plasmids of approximately 10 kb which hybridized with the 10.2 kb plasmid (group I) of P ostreatus NFFA 2.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2001.04a
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• pp.9-10
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• 2001

용융공정 $YBa_2Cu_3O_{7-x}$(123) 초전도체는 고자장 하에서도 통전특성이 우수하다 그러나 123 초전도체에는 미세균열이나 기공과 같이 초전도체의 통전특성에 유해 한 요인들도 다수 포함된다. 미세균열은 고온 정방정 상이 저온 사방정상으로 상변 태 시 발생하는 웅력에 의해 생성된다. 반면, 기공은 123 성형체를 녹이는 과정에서 123 상에 포함된 산소원자들이 격자로부터 이탈되고, 이 산소원자들이 모여 액상에서 기공을 형성한다. 제조공정에 따라 기공의 크기와 밀도가 다르지만 대략 수십 이크론 정도로 대단히 크다 생성된 기공 중 일부는 열처리 중에 소멸되나, 어떤 것들은 그대로 남아 초전도체의 치밀화를 방해한다. 본 연구에서는 123의 용융 및 $YBa_2Cu_3O_{7-x}$(211)과 액상으로의 분해 과정 및 포정반응과 관련된 미세조직을 조사하여 기공생성과 소멸과정을 조사하였고, 123의 최종 미세조직에 대한 기공의 영향에 대 하여 연구하였다. 열처리 스케쥴은 123-211-액상의 그림 l의 2원 상태도를 기초로 하여 결정하였다. 먼저 부분 용융상태에서의 기공의 분포를 알고자 시편을 105$0^{\circ}C$에서 0.5-1 시 간 유지한 후, 액체 질소통에 넣어 냉각하였다 (그림 2의 열처리 경로 CD)$\circled1$부분 용 융상태에서 급랭할 경우 211과 액상 상태가 그대로 유지되므로 액상에서의 기공분 포를 관찰할 수 있다. 또 다른 시편들은 그림 2의 @$\circled2$경로로 열처리하였다. 이 시편에서는 고온에서 생성된 211과 액상이 반웅하여 123 결정이 생성, 성장하므로 123 결정립 내의 기공분포를 알 수 있다. 그림 3은 시편에서의 기공과 액상포켓의 분포를 모식도와 각 부위의 미세조직 사진이다. 시편에는 산소가스 발생으로 인해 생성된 수형의 기공이 관찰된다. 기공은 시편의 중앙에 집중되며, 시편 바깥부분은 기공에 액상이 채워진 액상포켓이 관찰된다. 기공의 생성과 소멸과정은 다음과 같다. 출발물질인 123 분말이 211과 액상으로 분해될 때 산소가스가 배출되며, 이로 인해 액상에서 구형의 기공이 생성된다. 이들 중 일부는 액상으로 채워져 소멸되나, 나머지는 그대로 남는다. 특히, 시편 중앙에 서는 수십-수백 마이크론 크기의 커다란 기공이 다수 관찰된는데, 이는 기공의 합체로 만들어진 것이다. 포정반응 열처리 시 기공 소멸로 만들어진 액상포켓들은 주변 211 입자와 반응하여 123 영역으로 변한다. 이곳은 다른 지역과 비교하여 211 밀도 가 낮기 때문에, 미반응 액상이 남거나 211 밀도가 낮은 123 영역이 된다. 액상으로 채워지지 못한 구형의 기공들 중 다수가 123 결정 내로 포획되며, 그 형상은 액상/ 기공/고상 계면에너지에 의해 결정된다.

• Korean Journal of Psychosomatic Medicine
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• v.17 no.1
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• pp.23-29
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• 2009

Objectives : This research is to figure out the neurofeedback treatment for the inattentive children is effective in improving attention deficit and furthermore, in relieving hyperactivity and impulsivity. Methods : 20 children subjects participated for this study. C3-A1 protocol neurofeedback was given 15 to 20 times to each child, it is carried out to compare the degree of attention in each case every 5 times of neurofeedback by using ADHD Rating Scale-IV : Parent Version(ARS) and Attention Deficit Disorder Evaluation Scale-Home Version(ADDES-HV). Results : The subscale of mean inattention score of ARS was reduced from 14.2 to 8.8 significantly(p<0.05) after 20 sessions of neurofeedback treatment, also the subscale of mean impulsivity/hyperactivity score of ARS from 13.3 to 7.1. The subscales of mean inattention, impulsivity and hyperactivity score of ADDES-HV was also reduced significantly(p<0.05) after 20 sessions of neurofeedback treatment. The changes of scores appeared significantly(p<0.05) from 10-15 sessions of neurofeedback treatment. Conclusion : The results of this study suggest that neurofeedback can improve children's attention deficit, hyperactivity and impulsivity, there exists the possibility of being a method to treat ADHD.

• Journal of The Korean Association For Science Education
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• v.40 no.1
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• pp.61-75
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• 2020

In this study, external representation presented in two units, 'Property of Gas' and 'Changes of States of Matter,' in seventh grade of 2015 revised science curriculum, were analyzed to suggest educational implications. External representations presented in five science textbooks were analyzed according to the six criteria, which were 'type of representation,' 'interpretation of surface features,' 'relatedness to text,' 'existence and properties of a caption,' 'degree of correlation between representations comprising a multiple one,' and 'function of representation.' The characteristics of typical representations related to each achievement standard of two units were also analyzed. The results were as follows: The macro representations for 'type of representation', and explicit representations for 'interpretation of surface features' showed highest frequency. For 'relatedness to text' criteria, 'completely related and linked' and 'completely related and unlinked' representations showed the highest frequency. It means that most representations were properly related with the text. There were appropriate captions for most representations. The degree of correlation between representations comprising a multiple one was largely sufficiently linked with regards to the criteria 'degree of correlation between representations comprising a multiple one'. The complete representations for 'function of representation' showed the highest frequency in the aggregate, however incomplete representations showed more frequencies in the inquiry parts. The typical representations for each achievement standard differed in terms of the type, contained information, used symbols and so on. The educational implications with the use of representations presented in seventh grade textbook were discussed.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.191-195
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• 2000

This study was undertaken to estimate the exposed dose of the medical personnel during the intracoronary radiotherapy procedure as a part of ongoing SPARE (Seoul National University Hospital Post-Angioplasty Rhenium) trial. Data of thirty-four patients among forty-two irradiated patients participating in this trial due to coronary artery stenosis were retrospectively analyzed. Intracoronary radiotherapy was delivered to the patient immediately after angioplasty ballooning. Prescribed dose was 17 Gy to media of the diseased artery and was delivered with $^{188}Re$ filled balloon catheter. Dosimetry was carried out with GM counter at eight different points. Ten centimeter and forty centimeter from the patient's heart were selected to represent maximum and whole-body exposed dose of the operator, respectively. Median delivered dose was 111.6 mCi with average treatment time of 576 seconds. Average exposed dose rate at 10 cm and 40 cm from the patient's heart were 0.43 mSv/hr and 0.30 mSv/hr, respectively. Average exposed doses per treatment were 0.07 mSv and 0.05 mSv for 10 cm and 40 cm from the patient's heart, respectively. Exposed doses measured are much lower than recommended limit of 50 mSv for radiation workers or 1 mSv for general population in ICRP-60. This study proves that current method of intracoronary radiotherapy incorporated in this trial is very safe regarding radiation protection.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.2
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• pp.1-10
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• 1989

The major causes of the facial bone fractures are fractures are automobile collision or other accident, and fights. Of the facial bone fractures, the nasal bone fractures are monst common. According to Schroeder et al., 50% of facial bone fractures are isolated fractures of the nasal pyramid. But the fractured nasal bone is not immediately treated as other facial bone fractures. And it is necessary to delay the treatment of the combined nasal bone fractures with other jaw bone fractures because of the difficult anesthetic techniques. Therefore there are many residual nasal deformities following a fracture; nasal hump, saddle nose and alar rim defect. Many authors have suggested the methods to correct the post-traumatic nasal deformities. We have treated several patients with several methods and this paper presents the operating methods and results.

• Journal of Conservation Science
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• v.29 no.3
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• pp.279-286
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• 2013

It is characterized and classified as the type of red brown glass beads to compare the chemical composition and manufacturing technique on the 141 samples in 12 sites of the Three Kingdom Period analyzed until now. It can be divided into three types according to the chemical composition of stabilizers(CaO & $Al_2O_3$) and soda raw materials(MgO & $K_2O$) on the red brown glass beads except one sample. Type I of high alumina glass is identified as the most common types that is 78.6 % of the distribution ratio at analytical samples and is excavated the most from ruin sites. In contrast, type II, 13.6 % of distribution ratio at analytical samples, is about 5 % CaO and $Al_2O_3$, MgO and $K_2O$ at around 1.5 % is similar to the composition of plant ash glass. Type III is that the content of CaO is higher than $Al_2O_3$ and the content of MgO and $K_2O$ is below 1.5 %. It is the same as the composition of natron glass and its share is the lowest as 7.9 %. Of these, type III is divided into two types according to the content of MgO and $K_2O$. It is identified that manufacturing technique of type I and II is drawing and type III is casting method with microscopic investigations. Type II and III is estimated that raw materials is different because is confirmed in the majority of ruins in spite of the fact that distribution ratio is very low. So, red brown glass beads distributed in Korea Peninsula are divided into three types of glass culture.