• Journal of Welding and Joining
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• 제11권2호
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• pp.53-61
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• 1993

One of the most interesting and promising steel groups considered for the rocket motor case, aircraft and aerospace component is the maraging(martensitic plus aging) nickel steel, developed by International Nickel Company in 1960. This material attains a very high strength with good fracture toughness by simple heat treatments which do not involve a quenching. Full strength can be obtained by "maraging" at 480.deg. for 3 hours for the 18% Ni maraging steel. The effect of heat treatments was considered on the residual stress field of 18% Ni maraging steel weldments. In experiments, various heat treatments such as stress relieve heat treatment, aging and solution heat treatment were carried out of the GTA weldments and the residual stresses were measured by using the hole drilling method. Whereas the conventional pattern of residual stress shows the stresses to be maximum along the weld centerline with tensile stress extending into the heat affected zone, the pattern in maraging steels shows the centerline stress to be compressive. After welding, a series of aging, solution heat treatment and solution heat treatment plus aging treatment were carried out and the residual stresses were measured to reveal that these heat treatments almost completely remove the welding residual stresses.

• Journal of Mechanical Science and Technology
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• 제18권12호
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• pp.2204-2208
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• 2004

Ti-8Ta-3Nb has been developed as a new biomaterial. The experimental specimens are as-cast and forged Ti-8Ta-3Nb alloys. Treatment in a solution, ranging from 760 to 960$^{\circ}C$ has carried out. The microstructural research has carried out after the solution treatment and the hardness was measured. The specific heat and the length variations of Ti-8Ta-3Nb were also measured. The optimum temperature for the solution heat treatment of Ti-8Ta-3Nb was found to be 880$^{\circ}C$. This was based on the mechanical properties and the volume fraction of ${\alpha}$ phase and their phases shown from the results of the solution heat treatment. From the results, the ${\beta}$ transition temperature of Ti-8Ta-3Nb was found to be between 860$^{\circ}C$ and 880$^{\circ}C$.

• 한국콘텐츠학회논문지
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• 제13권2호
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• pp.505-511
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• 2013

경사진 지형을 갖는 축대칭 지형에 적용이 가능한 경계처리기법을 개발하였다. 섬 지형의 경우 복잡한 지형으로 인하여 유한요소모형을 사용하여 파의 변형을 해석하는 것이 좋지만 해수와 접하는 섬의 단면이 연직이 아닌 경우에는 수심이 0이 되어 경계면을 적절하게 처리하기 어렵다는 단점이 있다. 본 연구에서는 장파에 대한 해석해를 활용하여 임의의 경사진 경계면에 적용가능한 경계처리기법을 개발하였다. 이를 위해 지배방정식으로 완경사 방정식을 사용하였으며 계산 영역을 해석해 영역과 수치해 영역으로 구분하여 해석해 영역에 기존의 해석해를 적용한 후 수치해와 결합하여 모델을 완성하였다. 유도된 해는 기존의 해석해와 비교하여 그 타당성을 검증하였다.

• 한국염색가공학회지
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• 제21권1호
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• pp.21-29
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• 2009

In order to enhance the functionality of a cotton fabric actually used as a clothing material for patients, the fabrics were treated with a chitosan/nanosilver mixed solution. The nanosilver had excellent biocompatibility, provided expectation of an additional performance, did not harm human beings, and supplements chitosan, which was disadvantaged if used alone for fabric treatment. The nanosilver was mixed thereto and a treatment effect due to a mixing ratio was considered. This study was observed through mechanical properties and hand value which were the important function. The treatment of chitosan/nanosilver mixed solution gave a smoother surface than the treatment of chitosan alone. As a result of evaluation of the forms according to KES-FB system, Koshi was deduced, and both Numeri and Fukurami were increased. Thereby, the cotton fabric was a little smooth to provide elasticity, due to the treatment of chitosan/nanosilver mixed solution. THV of the treated fabrics calculated from this basis increased at all mixing ratio as compared with the untreated fabric. The fabrics treated with chitosan/nanosilver mixed solution were shown a better THV than the fabric treated with chitosan alone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제49권5호
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• pp.287-291
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• 2023

Odontogenic keratocysts (OKCs) located in the maxillae have rarely been reported in the literature. Standard treatment modalities for OKC range from marsupialization to marginal resection. However, most of the studies on OKC treatment have been related to mandibular OKCs. The anatomical structure and loose bone density of the maxillae and the empty space of the maxillary sinus could allow rapid growth of a lesion and the ability to tolerate tumor occupancy in the entire maxilla within a short period of time. Therefore, OKCs of the maxillae require more aggressive surgery, suchas resection. As an alternative, this report introduces a modified Carnoy's solution, a strong acid, as an adjuvant chemotherapy after cyst enucleation. This report describes the clinical outcomes of enucleation using a modified Carnoy's solution in patients with large OKCs on the posterior maxillae. In three cases, application of a modified Carnoy's solution had few side effects or morbidity. Each patient was followed for four to six years, and none showed any signs of recurrence. In conclusion, adjuvant treatment with a modified Carnoy's solution can be considered a treatment option capable of reducing the recurrence rate of OKC in the maxillae.

• 한국주조공학회지
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• 제35권5호
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• pp.109-113
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• 2015

In this study, the measurement of FN (ferrite volume fraction) and the solution annealing ratio at a temperature of $1130^{\circ}C$ were determined with 15A elbow fittings of shell cast SSC13, and the corrosion resistance with and without austenitizing solution annealing were investigated in comparison with AISI304. The delta ferrite phase was observed in the material due to the slow cooling effect of the shell mold casting. However, the delta ferrite phase decreased gradually with the solution annealing at a temperature of $1130^{\circ}C$. The hardness generally decreased with a heat treatment; however, its corrosion resistance was improved with the heat treatment. In addition, when a passivation treatment was applied, its corrosion ratio showed the lowest value. The pattern of general corrosion decreased due to the decrease in the delta ferrite phase with the solution annealing treatment. Consequently, it is suggested that the corrosion resistance of SSC13 elbow fittings can be improved by increasing the ratio of any solution annealing treatment used and by decreasing the ferrite phase. The relationship between the ratio of solution annealing and delta ferrite is expressed as follows: SA (solution annealing ratio,%) = 98 - FN (ferrite volume fraction, %).

• 한국포장학회지
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• 제7권1호
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• pp.25-30
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• 2001

The purpose of this study was to examine how can we keep the freshness of peeled chestnuts in distribution process. The 30 minutes impregnation treatment at the preservation solution of 0.3% consistency showed a good result. The solution treatment prevented from surface yellowing and quality degradation of peeled chestnuts. And, in vaccum packaging after treating chemicals surface drying was faster than the other packaging from 7th day. A vitamin C treatment was no effective to restrain the growth of microbials.

• 한국염색가공학회지
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• 제10권1호
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• pp.11-19
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• 1998

For the purpose of standardization and practicability of dyeing by natural dyes, the mordanting and dyeing properties of cochineal and carminic acid were studied. Appropriate extraction, dyeing and mordanting condition of cochineal were determined, and the effect of mordanting method on dye uptake and color fastness of dyed fabric was investigated. The maximum absorbance of cochineal solution was 495nm, carminic acid was 533nm and 577nm. The color of carminic acid solution was affected by pH 6~9. The optimum temperature to extract cochineal was $80-100^\circ{C}$ and dyeing solution for 1 hour. And effective dyeing time to silk was 60min. Effective mordanting temperature was $80^\circ{C}$, and its time was 30min. In case mordants concentration, the maximum absorbance of Sn solution was 3%, K, Cu and Cr were in 1%. K/S value of dyeing fabrics was recoginazed by mordant treatment, specially Fe, Sn, Al, Cu. In the case of cochineal light fastness was increased by mordant treatment, specially Fe treatment. Perspiration fastness was good in acidic solution than in alkaline solution and perspiration fastness of cochineal was poor. Fastness of abrasion and dry-cleaning were good and these fastness improvement were generally effective for post-mordanting treatment.

• 한국표면공학회지
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• 제47권4호
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• pp.186-191
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• 2014

Double layer films which consisted of aluminum(Al) and magnesium(Mg) have been prepared by e-beam deposition. The structure, alloy phase, and corrosion resistance of the prepared films were investigated before and after heat treatment. The first (bottom) layer fixed with Al, and the thickness ratio between Al and Mg layers has been changed from 1 : 1 to 5 : 1, respectively. Total thickness of Al-Mg film was fixed at $3{\mu}m$. The cold-rolled steel sheet was used as a substrate. Heat treatment was fulfilled in an nitrogen atmosphere at the temperature of $400^{\circ}C$ for 2, 3 and 10 min. Surface morphology of as-deposited Al-Mg film having Mg top layer showed plate-like structure. The morphology was not changed even after heat treatment. However, cross-sectional morphology of Al-Mg films was drastically changed after heat treatment, especially for the samples heat treated for 10 min. The morphology of as-deposited films showed columnar structure, while featureless structure of the films appeared after heat treatment. The x-ray diffraction data for as-deposited Al-Mg films showed only pure Al and Mg peaks. However, Al-Mg alloy peaks such as $Al_3Mg_2$ and $Al_{12}Mg_{17}$ appeared after heat treatment of the films. It is believed that the formation of Al-Mg alloy phase affected the structure change of Al-Mg film. It was found that the corrosion resistance of Al-Mg film was increased after heat treatment.

• Corrosion Science and Technology
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• 제6권3호
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• pp.140-146
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• 2007

In the paper, with corrosion velocity measurement and metallographic observation on specimens after sulfuric acid/ferric sulfate boiling experiment, intergranular corrosion tendency of the new type ultra low carbon stainless steel developed by ourselves which experienced solution treatment at different temperatures was evaluated. A VHX 500 super depth field tridimensional microscope was used to observe corrosion patterns on the sample surfaces. The depth and width of grain boundary corrosion groove were measured by the tridimensional microscope, which indicated that the corrosion degrees of the samples which received solution treatment at different temperatures are quite different. Transgranular corrosion at different degree occurred along with forged glide lines. After comparison it was proved that the stainless steel treated at $1100^{\circ}C$ performs very well against intergranular corrosion.