덕유산 국립공원의 담수조류상

김백호,최민규,정연태,이종빈,위인선,길봉섭 원광대학교 환경과학연구소 1996 環境科學硏究誌 Vol.5 No.1

초격자 고경도 나노 다층막 소재의 복합경도 해석을 통한 계면 강화 효과 분석

김성훈,이윤희,박종극,백영준,권동일 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.12

Multilayer coatings consisting of very thin layers of nitride materials deposited by magnetron sputtering (sometimes called superlattices) exhibit hardnesses over 50 GPa, much higher than that of single layers. Several explanations for this hardness increase have been proposed, including dislocation blocking by layer interfaces, Hall- Petch strengthening, strain effects at layer interfaces, and the supermodulus effect. Among these, dislocation blocking has been generally accepted as a dominant factor in large hardness enhancement. However, the interface between two materials consisting of multilayers is broadened due to interdiffusion. The magnitude of hardness enhancement by the interface has not yet been quantified for real systems. In this study, the concept of composite hardness is introduced to quantify the interface-related hardness enhancement. We suggest a composite hardness equation and quantifythe magnitude of hardness increase by using an equation based on the interface hardness and the interface thickness derived by comparing results derived from this equation and those determined in nanoindentation tests. Three multilayer systems, such as TiN/VN, TiN/NbN and CrN/NbN were used in the equation.

금강 및 만경강 상류의 식물플랑크톤 군집구조와 동태

김백호,최민규,정연태,이종빈,위인선,길봉섭 원광대학교 환경과학연구소 1997 環境科學硏究誌 Vol.6 No.1

노화와 간경변이 인체의 적혈구, 혈장 및 위 점막의 Glutathione 농도와 Glutathione Peroxidase 활성도에 대해 미치는 영향

백광호,김종혁,백일현,한태호,박현주,박상훈,서중산,박충기,유재영 대한노인병학회 2001 대한노인병학회지 Vol.5 No.3

하악 전치부에 발생한 과잉치 : A CASE REPORT

김성희,박종하,양연미,김재곤,백병주 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.1

과잉치는 유치열에서 0.3-0.8%, 영구치열에서 1.0-3.5% 정도로 발생하며, 2:1로 남자에게 호발, 9:1로 상악에서 호발한다. 그 중 하악 전치부에서 발생하는 빈도는 전체 과잉치중에서 2-4%의 매우 낮은 빈도를 보인다고 보고되었다. 과잉치가 계속 존재할 경우 나타날 수 있는 합병증으로서 치간이개, 인접한 정상치아의 맹출장애, 치관의 형성이상, 인접치의 치근흡수, 함치성 낭종 등을 들 수 있으며, 치열 발육 중인 어린이의 경우 성장 중임을 감안하여 바람직한 교합유도를 위한 정확한 진단과 함께 적절한 처치가 필요하다. 본 증례는 전복대학교병윈 소아치과에 내원한 6세 환아의 하악 전치부에서 발견된 양측성 매복 과잉치로서 그 중 한개는 영구치와 융합된 경우를 보고하는 바이다. Supernumerary tooth describes an excess of tooth number, which are found in primary dentition with 0.3-0.8%, permanent dentition with 1.0-3.5% prevalence. Their frequency is about 2:1 (male vs female) and 9:1 (maxilla vs mandible). However, occurrence is very rare in the incisor region of the mandible. We need a early diagnosis and appropriate treatment plan because of possibility of diastema, eruption failure, displacement, rotation of the associated permanent teeth, root resorption, dentigerous cyst, with presence of the supernumerary teeth. This is a case report about two impacted supernumerary teeth found in madibular anterior region of 6 years old girl. One was extracted and another was retained because of fusion with permanent central incisor on the labial surface.

여러가지 수복물의 polishing조건에 따른 치수 온도변화

김재곤,이승영,박종하,백병주,양종숙 大韓小兒齒科學會 1999 大韓小兒齒科學會誌 Vol.26 No.2

수복물의 연마의 중요성에 대하여 많은 연구들이 이루어져 왔으며, 이는 수복물의 금속성질의 개선, 변연적합성의 증가 그리고 치태축적의 감소 등을 이유로 시행된다. 그러나 불행하게도 수복물에 대한 연마시 열의 발생으로 인하여 치수부위에 손상을 초래하므로 열의 발생을 최소화하려는 노력이 뒤따라야 할 것이다. 이에 본 연구에서는 수복물의 연마시 회전속도의 차이, 냉각제의 적용 유무, 여러 종류의 수복물의 차이, 간헐적인 연마와 연속적인 연마의 차이 그리고 잔존 상아질의 두께의 정도에 따른 치수내부에서의 열의 변화를 알아보기 위하여 발거된 구치에 5급 와동을 형성한 후 복합레진(Z100, 3M co), resin-mod-ified GLC(Dyract, Fuji II LC), 그리고 아말감(Degussa)등으로 충전하였으며, 다양한 조건에서의 연마를 시행, 치수내부에서의 열의 변화를 측정하여 다음과 같은 결과를 얻었다. 1. Amalgam을 건조한 상태에서 연마시 다른 재료에 비해 큰 치수내 온도 상승을 보였다.(P<0.05). 그러나 Z100, Dyract, Fuji II LC간에는 간헐적 수복물 연마와 연속적인 수복물 연마 모두 어떤 경우든 유의차가 없었다.(P>0.05). 2. 같은 조건으로 연마를 시행했을 때, 간헐적인 연마보다 연속적인 연마를 한 경우가 치수내 온도가 더 크게 상승하였다.(p<0.01). 3. 아말감과 Dyract에 있어서는 잔존 상아질의 차이에 따른 치수내 온도변화에 유의한 차이를 보였으나(P<0.01), Fuji II LC에 있어서는 유의성이 없었다(P>0.01). 4. 냉각제의 유무에는 관계없이 어떤 경우든 시간에 따른 온도 상승을 보였다. 그러나, 냉각제를 사용한 경우가 냉각제를 사용하지 않은 경우에 비해 온도 상승값이 훨씬 작았다.(P<0.01) The importance of finishing and polishing the restoration has been described by several authors. The final step provides for improved metallurgical properties, better marginal adaptation, reduced plaque accumulation. Unfortunately, finishing of the restorations can produce damage from temperature rises at the pulpal wall. The aim of this study was to determine the changes in temperature can be occurred during the use of finishing and polishing instruments under a variety of conditions. ; with or without a water coolant, intermittent or continuous operation, high or low rotation speed, remaining dentin thickness, and various restorative materials. Class V preparations were cut on extracted molars and restored with composite resin(Z 100), resin-modified glass ionomer cements(Dyract, Fuji II LC), and amalgam. Finishing was done with aluminum oxide coated disc(Sof-lex polishing disc, 3M, USA). The following results were obtained. 1. The rise of temperature during polishing of amalgam restorations was the highest among the all experimental groups except polishing with water coolant(P<0.05). However, there were no statictical differences in temperature rises between Z 100, Dyract and Fuji II LC(P>0.05). 2. The intrapulpal temperature was greatly influenced by the applied time, and intermittent polishing was showed significantly lower temperature rises than continuous polishing(p<0.01). 3. The intrapulpal temperature was increased according to the application of polishing regardless of using water coolant. However, polishing with water coolant showed significantly lower temperature in the pulp than not used water coolant(P<0.01).

제주도민 STR 다형의 유전학적 특성 연구

김종진,김순희,백형순,이경룡,최상규 內務部 國立科學搜査硏究所 2002 國立 科學 搜査 硏究所 年報 Vol.34 No.-

항목기반의 인터넷 쇼핑 시스템 구현

김종완,백영욱,남인길 대구대학교 과학기술연구소 1998 科學技術硏究 Vol.5 No.2

An internet shopping system is presented on which a manager can add, modify. delete computers and peripheral devices. and customers can choose and buy some products. The system gives customers a chance to choose the products once again by putting them in a cart. In this paper, not only a simple shopping mall but also the basic database for internet marketing are implemented well. For the purpose of implementing this marketing system, every components including customers' buying informations to be recorded in marketing database, the approach to customers. marketing strategy and methodology have been restored the information on potential customers as well as current one. The proposed method implements an item-based product sale system, and therefore it can provide an easier shopping service than the existing internet shopping malls.

척수신경세포에서의 아포프토시스 관련인자에 관한 면역조직화학 연구

김종민,정윤희,신정민,박경한,조사선,백상호,차중익 대한해부학회 1999 Anatomy & Cell Biology Vol.32 No.4

Al-Li 합금의 시효석출에 미치는 Cu, Mg 및 Zr 첨가의 영향

백승남,김종원 조선대학교 생산기술연구소 1995 生産技術硏究 Vol.17 No.2

The purpose of this study is to improve the low toughness of Al-Li binary alloy which is expected to be widely used for the structural materials of the aircraft and light industry. For the sake of improvement addition Cu, Mg and Zr were together added. The kind of shape and variation of precipitation phase formed by age precipitation in alloy with addition element and the mechanism of nucleation were closely examined. The above were carried out through investigation of the variation of mechanical properties such as tensile strength, yield strength, hardness and elongation, microstructure by TEM, and the formation and dissolution of precipitate by thermo analysis. 1. For Al-Li-Cu-Mg-Zr porynary alloy at 170℃, the strength is at the highest at 72hr aging, but elongation is at the lowest at 65hr aging. 2. There are various precipitates of δ', α', S' and T1 at 170℃ aging. It is assumed that these mixed structures have an effect on the strength and elongation in the under aging. This is attributed to multipicative mutual supplement action by coexistence of composite phase rather than δ'single phase. 3. The resurt of thermo analysis of as-quenched shows that endothermic range regarded as dissolution of G. P. zone appeared at 130℃ lower by about 70℃ than predictable on the phase diagram.