• 대한소아치과학회지
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• 제32권1호
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• pp.132-135
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• 2005

본 연구의 목적은 유전치 심미수복의 새로운 방법으로 glass fiber를 이용한 강화형 strip crown의 사용을 제시하고자 하는 것이다. Strip crown의 제작을 위하여 celluloid crown form(3M, USA)과 복합레진은 Z100(P shade, 3M, USA)을, 유동성 복합레진은 Aeliteflo(Bisco Inc., USA)를 사용하였다. 상아질 결합제는 Clearfil SE Bond(Kuraray Medical Inc., Japan)를 사용하였고 강화를 위하여 그물형 glass fiber(TESCERA Fiber Mesh, Bisco Inc, USA)를 사용하였다. 적절한 크기의 celluloid crown form을 성형하여 삭제된 치아에 시적한 후 레진 접착제와 유동성 복합레진으로 처리한 그물형 glass fiber를 설측 내면에 삽입하고 광중합하였다. 잔여 공간에 복합레진을 채우고 치아에 끼운 다음 광중합하였다. 복합레진의 심미성은 유지하면서 glass fiber로부터 기계적 장점을 얻을 수 있을 것으로 사료된다. 새로운 강화형 strip crown의 물성에 대한 후속연구가 필요하다.

• Journal of Photoscience
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• 제11권2호
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• pp.83-87
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• 2004

A porphyrin compound containing a crown ether moiety (Por-Crown) and its zinc complex (ZnPor-Crown) have been prepared and the effect of the addition of alkali metal on their fluorescence has been investigated. As alkali metal cations were added, the absorption and fluorescence maxima did not change. However, the absorbance and intensity of fluorescence increased dramatically. Among the alkali metal cations tested, addition of K$^{+}$ and Cs$^{+}$ showed strongest enhancement of absorbance and fluorescence intensity of Por-Crown and ZnPor-Crown.own.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.256.1-256.1
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• 2003

As a part of our ongoing research to discover novel monamine oxidase (MAO) inhibitors of plant origin, we found that a MeOH extract from the whole plant of Cayratia japonica (Vitaceae) strongly inhibited the MAO activity in mouse brain. The EtOAc-soluble fraction was. therefore, subjected to the bioactivity-guided fractionations to isolate the active compounds. (omitted)

• 한국산림과학회지
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• 제97권5호
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• pp.501-507
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• 2008

The data of crown width with 4 directions, DBH, tree height, and coordinate for sample trees were collected from 30 permanent sample plots in secondary fore st of the Maoershan Experimental Forestry Farm, Northeast China. In this paper, the competition of individual trees in stand were discussed for secondary forest by using iterative Hegyi competition index and crown overlap index that represented the competitive and cooperative interactions among neighboring trees. Active competitors of subject tree in the competition zone were selected to calculate the iterative competition index. Using the results of crown classification based on the equal crown projection area, a new distance dependent competition index called crown overlap index (COI) was developed for secondary forest. The COI performed well in describing the crown competition rather than crown competition factor (CCF). The individual-based competition index discussed in this paper will provide more precise for developing individual tree growth models for secondary forest and it can also use to adjust the stand structure for spatial optimal management.

• 대한치과의사협회지
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• 제54권7호
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• pp.492-500
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• 2016

Crown fractures are a common type of dental injuries and very frequently occurred on maxillary anterior teeth, area of requiring a rapid aesthetic recovery. Crown fragment reattachment is a simple and conservative method to restore the fractured teeth. The technique promotes esthetic outcomes as utilizing natural contour, shade, surface texture of teeth and gives mechanical similarity in terms of wear-resistance. Also it gives emotional positive responses to patients and requires less of chair time and costs. This case report presents two cases of crown fragment reattachments on maxillrary anterior teeth, including one complicated crown fracture and one uncomplicated crown fracture. If the fragment is available in cases of crown fractures, reattachment of fragment can be regarded as a predictable alternative. However, it is all the time important that a close conversation informing the patients about the limitations and prognoses of this treatment option.

• 대한치과보철학회지
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• 제42권1호
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• pp.73-82
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• 2004

Statment of problem : Little in known about the importance of selection of various double crowns as retainer in determining the outcome of treatment with double crown retained removable partial denture. Purpose : To obtain information about the effects and the results of this treatment modality. Material and methods : This study describes 61 double crown retained removable partial dentures worn by 51 patients from Samsung Medical Center, Seoul a time ranging between 6 and 48 months and evaluate occlusal contacts on the denture teeth, denture movement, incidence of denture relining, denture retention, fracture of dentures and abutments, hygiene, residual ridge inflammatory changes, number of lost abutment,. interruption of denture use. Results : One tenth of all the restorations were relined. Restorations in 21 arches fractured repeatedly for various reasons . There was no apparent interrelationship between fractures and the five groups. Conclusion : Good prognoses of removable partial dentures were shown in all groups(Kennedy Classes I, II, III, combination and few remaining abutment).

• The Korean Journal of Ecology
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• 제8권4호
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• pp.197-200
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• 1985

The relations of crown width and DBH for Pinus densiflora, Pinus rigida, Pinus koraiensis, and Ginkgo biloba were accomplished to estimate the level of crown competition. Measurements of the relations revealed that crown width and DBH were highly correlated for the same species. Also it seems that these relations are independent of age and site quality. The results of regression analysis were as follow: P. densiflora, Y=0.3477X+0.3828 r=0.95 p. rigida, Y=0.3537X+0.1645 r=0.95 P. koraiensis, Y=0.2895X+0.6310 r=0.92 G. biloba, Y=0.4360X+0.0995 r=0.90 The significant differences between G. biloba and pine species seems due to their structural differences of crown formation according to tree species. As results of computing Maximum Crown Area and Crown Competition Factor as indices of crown competition, they indicated that P. densiflora would grow better under the natural conditions.

• 한국산림과학회지
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• 제96권2호
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• pp.189-196
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• 2007

Allometry, basal area equations, and volume equations were developed with various tree measurement variables for the major species, Quercus mongolica and Quercus variabilis, in Korean natural hardwood forests. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, crown width) and relative size (relative diameter, relative height) as well as competition measures (competition index, crown class, exposed crown area, percent exposed crown area, live crown ratio). For tree volume equations, the combined-variable and Schumacher models were fitted with DBH, total height and crown width for both species.

• Bulletin of the Korean Chemical Society
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• 제19권2호
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• pp.207-211
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• 1998

Potentiometric characteristics of DOS plasticized PVC-based membranes containing upper-rim calix[4]crown neutral carrier to various metal cations and protonated alkylamines have been examined. Although the calix[4]crown-based membrane electrodes exhibited substantial emf responses to alkali and alkaline earth metal cations, their high detection limits (- log[Cs+]=4.5) and sub-Nernstian response slopes (48 mV/pCs+) to the most selective cation, cesium, indicate that the metal cation complexing ability of calix[4]crown is much weaker than that of macrocyclic crown ethers. However, the calix[4]crown-based membrane electrodes exhibited near-Nernstian response slopes (56 mV/decade for hexylNH3+) with low detection limits (log[hexylNH3+]= - 6.7) to most alkylammonium ions compared to those of blank (DOS plasticized PVC membrane with no ionophore) or crown ether-based membranes. While the selectivity patterns of blank and crown ether-based membranes are determined primarily by the lipophilicity of alkylammonium ions, the membranes doped with calix[4]crown ionophore could effectively discriminate the steric shapes of nonpolar alkyl groups of alkylammonium ions.

• 한국정밀공학회지
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• 제12권3호
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• pp.73-81
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• 1995

To find a way for establishing work roll initial crown according to roll conditions, computer simutation for predicting plate crown in plate mill is done and effects of roll conditions on plate crown is analyzed. Toll gap rorfile and plate crown are measured to be compared to the calculated values. As a result, regression equation to establish work roll initial crown according to roll conditions such as backup roll diameter, backup roll crown and work roll diameter is obtained.