• 헤리티지:역사와 과학
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• 제54권4호
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• pp.78-89
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• 2021

유기잔존물 분석(organic residues analysis)은 동식물의 종에 따라 물질을 구성하고 있는 주요 성분이 다르다는 특성을 이용하여 유기물 시료의 종류를 밝혀내는 분석 방법이다. 본 연구에서는 의정부 신곡동 유적에서 출토된 조선시대 회묘 내 목관 부착 유기잔존물과 현대 재료에 대한 과학적 분석을 적용하여 유기잔존물의 주성분을 확인하고 유기물의 용도를 추정하여 과거 생활 모습을 밝힐 수 있는 자료를 확보하고자 하였다. 목관 부착 유기물과 현대 재료는 적외선 분광 분석(FT-IR)과 기체 크로마토그래피-질량 분석(GC-MS)을 수행하였다. 목관 내부에 부착된 유기물의 FT-IR 분석 결과 식물성 천연 수지 물질로 확인되었다. 또한 천연 수지의 특성 인자를 확인하기 위해 GC-MS 분석 결과 디하이드로아비트산(dehydroabietic acid), 피마릭산(pimaric acid) 등 아비탄(abietane)과 피마란(pimarane)의 디터페노이드(diterpenoid) 화합물과 포화·불포화지방산 성분이 함께 검출되었다. 디터페노이드 화합물은 주로 소나무과 수지에서 나타나는 성분이다. 소나무과 수지에서 기인하는 송진은 문헌에 접착제 재료로 사용된 기록이 있으며, 유기물 시료가 목관 이음새 부분에 잔존하고 있었던 점을 고려한다면 목관에 부착되어 있던 유기물은 소나무과 수지로 만들어진 접착 물질로 추정된다. 또한 디터페노이드 화합물과 함께 검출된 지방산은 식물성 기름에서 유래된 성분으로, 문헌의 기록처럼 송진과 기름을 혼합하여 만든 것으로 추정할 수 있다. 본 연구를 통해 고고자료에 남아 있는 유기물이 매장 환경에서도 그 특성이 남아 있는 것을 확인할 수 있었고, 당시 사용되었던 천연 수지의 종류와 용도를 밝힘으로써 과거 생활 모습 복원에 중요한 정보를 확보하였다는 점에서 큰 의미가 있다고 본다.

• 분석과학
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• 제22권3호
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• pp.191-200
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• 2009

이 연구는 소형방출챔버와 방출셀을 이용한 총휘발성유기화합물(TVOC) 방출시험결과의 상관성을 규명하여 방출셀을 이용한 액상 건축자재 오염물질 방출시험 방법을 정립하고 활용방안을 제시하기 위한 기초 자료를 확보하고자 수행되었다. 소형방출챔버와 방출셀을 이용한 액상 건축자재 방출시험을 실시하기 위해 방출시험 적합성 여부를 판단하고 최적조건을 확립하기 위하여 방출시험장치, 분석기기에 대한 성능평가를 실시하였다. 방출시험 장치인 소형방출챔버와 방출셀의 배경농도 청정도, 기밀도, 회수율, 분석장치인 열탈착장치 회수율 및 GC/MS 기기재현성, 방법검출한계(MDL) 등을 평가한 결과 방출시험장치와 분석기기의 조건은 안정적이고 재현성과 감도가 양호하여 액상 건축자재에서 방출되는 오염물질에 대한 측정 분석조건이 최적화되었음을 확인할 수 있었다. 페인트, 접착제, 실란트로 구성된 40개의 액상 건축자재를 대상으로 소형방출챔버와 방출셀을 이용하여 오염물질 방출시험을 실시한 결과 방출되는 총휘발성유기화합물의 농도는 소형 방출챔버와 방출셀에서 모두 대수정규분포(log normal distribution)하였으며 시험방법차이에 따른 방출량 분포의 차이는 크지 않았다. 또한 방출셀을 이용하여 오염물질 방출시험을 실시하였을 때, 소형방출챔버를 이용하였을 때보다 약 1.35~1.41배 높은 방출량을 나타내었으며 상관계수(r)가 약 0.91~0.97의 범위를 보여 높은 상관성이 있는 것으로 확인되었다.

• Archives of Plastic Surgery
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• 제42권4호
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• pp.431-437
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• 2015

Background Repair of facial laceration in the emergency department can pose a number of difficulties. Children can be uncooperative, but adults can also be if they have sustained head trauma or are intoxicated. Leukosan SkinLink consists of topical adhesive and adhesive tape that can be applied easily to long or tense wounds. In this study, the authors compared conventional suturing with Leukosan SkinLink for facial laceration patients in the emergency department. Methods The prospective study was carried out from March 2013 to September 2013 with linear facial laceration patients visiting the emergency department. Exclusion criteria were open fractures, joint injuries, skin defects, hairy skin, and mucosa. The author used Leukosan SkinLink for skin closure in the experimental group and used conventional suturing in the control group. The scar evaluation using the Patient and Observer Scar Assessment Scale (POSAS) along with satisfaction scores, procedure times, and complications were compared. Results A total of 77 patients (30 in the control group and 47 in the experimental group) participated and underwent follow-up for 6 months postoperatively. The scar assessment using the POSAS and the satisfaction score in both groups were similar. The average procedure time in the experimental group was shorter. In the control group, there were four cases of wound dehiscence, two of infection, and one of skin necrosis, whereas four cases of wound dehiscence and one allergic reaction occurred in the experimental group. Conclusions With a simple application technique, Leukosan SkinLink is a new effective method for facial laceration repair especially useful for children and uncooperative adults.

• The Journal of Advanced Prosthodontics
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• 제10권1호
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• pp.43-49
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• 2018

PURPOSE. The purpose of this in vitro study is to examine the effects of a nano-structured alumina coating on the adhesion between resin cements and zirconia ceramics using a four-point bending test. MATERIALS AND METHODS. 100 pairs of zirconium bar specimens were prepared with dimensions of $25mm{\times}2mm{\times}5mm$ and cementation surfaces of $5mm{\times}2mm$. The samples were divided into 5 groups of 20 pairs each. The groups are as follows: Group I (C) - Control with no surface modification, Group II (APA) - airborne-particle-abrasion with $110{\mu}m$ high-purity aluminum oxide ($Al_2O_3$) particles, Group III (ROC) - airborne-particle-abrasion with $110{\mu}m$ silica modified aluminum oxide ($Al_2O_3+SiO_2$) particles, Group IV (TCS) - tribochemical silica coated with $Al_2O_3$ particles, and Group V (AlC) - nano alumina coating. The surface modifications were assessed on two samples selected from each group by atomic force microscopy and scanning electron microscopy. The samples were cemented with two different self-adhesive resin cements. The bending bond strength was evaluated by mechanical testing. RESULTS. According to the ANOVA results, surface treatments, different cement types, and their interactions were statistically significant (P<.05). The highest flexural bond strengths were obtained in nano-structured alumina coated zirconia surfaces (50.4 MPa) and the lowest values were obtained in the control group (12.00 MPa), both of which were cemented using a self-adhesive resin cement. CONCLUSION. The surface modifications tested in the current study affected the surface roughness and flexural bond strength of zirconia. The nano alumina coating method significantly increased the flexural bond strength of zirconia ceramics.

• Journal of the Korean Wood Science and Technology
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• 제45권4호
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• pp.432-443
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• 2017

Maltodextrin and citric acid are two types of natural materials with the potential as an eco-friendly binder. Maltodextrin is a natural substance rich in hydroxyl groups and can form hydrogen bonds with lignoselulosic material, while citric acid is a polycarboxylic acid which can form an ester bond with a hydroxyl group at lignoselulosic material. The combination of maltodextrin and citric acid as a natural binder materials supposed to be increase the ester bonds formed within the particleboard. This research determined to investigate the bonding properties of a new adhesive composed of maltodextrin/citric acid for nipa frond particleboard. Maltodextrin and citric acid were dissolved in distillated water at the ratios of 100/0, 87.5/12.5, 75/25 and 0/100, and the concentration of the solution was adjusted to 50% for maltodextrin and 60% citric acid (wt%). This adhesive solution was sprayed onto the particles at 20% resin content based on the weight of oven dried particles. Particleboards with a size of $25{\times}25{\times}1cm$, a target density $800kg/m^3$ were prepared by hot-pressing at press temperatures of $180^{\circ}C$ or $200^{\circ}C$, a press time of 10 minute and board pressure 3.6 MPa. Physical and mechanical properties of particleboard were tested by a standard method (JIS A 5908). The results showed that added citric acid level in maltodextrin/citric acid composition and hot-pressing temperature had affected to the properties of particleboard. The optimum properties of the board were achieved at a pressing temperature of $180^{\circ}C$ and the addition of only 20% citric acid. The results also indicated that the peak intensity of C=O group increased and OH group decreased with the addition of citric acid and an increase in the pressing temperature, suggesting an interreaction between the hydroxyl groups from the lignocellulosic materials and carboxyl groups from citric acid to form the ester groups.

• Journal of Welding and Joining
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• 제34권1호
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• pp.21-25
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• 2016

The automotive vehicle is made through the following processes such as press shop, welding shop, paint shop, and general assembly. Among them, the most important process to determine the quality of the car body is the welding process. Generally, more than 400 pressed panels are welded to make BIW (Body In White) by using the RSW (Resistance Spot Welding) and GMAW (Gas Metal Arc Welding). Recently, as the needs of light-weight material due to the $CO_2$ emission issue and fuel efficiency, new joining technologies for aluminum, CFRP (Carbon Fiber Reinforced Plastic) and etc. are needed. Aluminum parts are assembled by the spot welding, clinching, and SPR (Self Piercing Rivet) and friction stir welding process. Structural adhesive boning is another main joining method for light-weight materials. For example, one piece aluminum shock absorber housing part is made by die casting process and is assembled with conventional steel part by SPR and adhesive bond. Another way to reduce the amount of the car body weight is to use AHSS (Advanced High Strength Steel) panel including hot stamping boron alloyed steel. As the new materials are introduced to car body joining, productivity and quality have become more critical. Productivity improvement technology and adaptive welding control are essential technology for the future manufacturing environment.

• 한국산학기술학회논문지
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• 제11권2호
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• pp.608-613
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• 2010

본 연구는 건축용 바닥재로 널리 이용되는 PVC 상재의 표면을 열에 의한 손상으로부터 보호하기 위하여 기존에 사용하는 광경화형 우레탄-아크릴 수지에 내열성(anti-cigar burning)을 향상시킨 광경화형 수성도료 개발에 관한 것이다. PVC 바닥상재용으로 사용되는 내열기능성이 없는 우레탄-아크릴 수지에 인계화합물을 주원료로 합성한 내열재, 구아니딘을 주원료로 합성한 내열재, 일시적 방염제로 사용되는 제 2인산암모늄을 수지의 양 대비 함량(wt%)을 10, 20, 30%로 변화하여 첨가한 후 배합하여 수지의 내열성을 향상시킨 코팅액을 제조하였다. 제조한 코팅액은 코팅층의 두께조절이 가능한 Bar-coating을 사용하여 PVC 바닥상재에 코팅한 후, 내열성, 부착력, 내화학성, 코팅두께 등의 코팅층 표면물성을 평가하였다. 연구결과, 수지에 인계화합물을 주원료로 합성한 내열재 30%를 혼합하여 제조한 코팅액을 Bar-coater No.12로 코팅한 코팅표면이 열에 의한 손상이 가장 적고, 부착력 100%, 내화학성 양호로 가장 좋은 물성을 보였다. 전반적으로 내열재 함량이 높고, 코팅 두께가 두꺼울수록 내열성이 우수한 것으로 나타났다.

• Journal of Pharmaceutical Investigation
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• 제29권2호
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• pp.111-115
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• 1999

We have studied the transdermal flux of prostaglandin $E_1$ $(PGE_1)$ from a hydrogel patch through hairless mouse skin, to test the possibility of developing a transdermal delivery system. Karaya gum patch containing $PGE_1$ was prepared by casting method. $PGE_1$ was stable in the patch for 10 weeks. The effect of current application, enhancer (propylene glycol monolaurate : PGML), adhesive and patch thickness on the flux was studied using side-by-side diffusion cell. Passive flux of $PGE_1$ was negligible. Cathodal delivery increased the flux about 20 fold. As the concentrations of PGML increased, flux increased. When 5% PGML was used as the enhancer, maximum flux by cathodal iontophoresis was $55\;{\mu}g/cm^2\;hr$. It increased about 2 folds to $100\;{\mu}g/cm^2\;hr$, when the amount of PGML used was 9%. Large increase in flux and the decrease in time to reach maximum flux were observed when the skin was pretreated with neat PGML (maximum flux obtained was about $200\;{\mu}g/cm^2\;hr$). Use of adhesive decreased the flux significantly. To the contrary of our expectation, increase in current density decreased the flux. These flux data together with the stability data indicate that, though the onset of sufficient delivery occur after 1-2 hours of application, therapeutic amount of $PGE_1$ can be delivered through skin using iontophoresis and penetration enhancer.

• 대한수의학회지
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• 제26권1호
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• pp.79-85
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• 1986

This paper deals with the isolation of Salmonella on 3 herds during the period from May 1984 to May 1985. Isolated Salmonella were examined for serotypes, adhesive fimbriae, antibiotic susceptibility and detection of R plasmid. The results were as follows; Of total 1505 cattle, 24 Salmonella were isolated from 18 cattle (1.2%) and their serotypes were S. enteritidis (9 strains), S. derby(4 strains), S. infantis (1 strain), $C_1$ group(8 strains), $C_2$ group(1 strain) and untypable(1 strain). Twelve strains of Salmonella were isolated from 227 cattle with diarrhea and their serotypes were S. enteritidis(4 strains), S. derby(3 strains), S. infantis(1 strain), $C_1$ group(3 strains) and untypable(1 strain). The isolation rate of Salmonella in cattle varied from 1.6 to 0.9% in 3 herds, it was higher in summer and autumn and lower with the age. Of total 24 strains, 23 were adhesive type 1 fimbriae. Antibiotic susceptibility test of Salmonella isolated was performed by the agar dilution method, using 9 antibiotics as follows: ampicillin(Am), chloramphenicol(Cm), gentamicin(Gm), kanamycin(Km), nalidixic acid(Na), rifampicin(Rf), streptomycin(Sm), sulfadimethoxine(Su) and tetracycline(Tc). All the strains tested were susceptible to Am, Cm, Gm, Km, Na, Rf and Tc. Of total 24 strains, 23(95.8%) were resistant to Su and 14(58.3%) to Sm. Of the 23 resistant Salmonella strains, all the strains were found to carry R plasmid. Among them, two strains which had the R plasmid conferring SmSu resistance was transferable at $25^{\circ}C$ only.

• The Journal of Advanced Prosthodontics
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• 제5권3호
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• pp.248-255
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• 2013

PURPOSE. This study compared the effect of three intraoral repair systems on the bond strength between composite resin and zirconia core. MATERIALS AND METHODS. Thirty zirconia specimens were divided into three groups according to the repair method: Group I-CoJet$^{TM}$ Repair System (3M ESPE) [chairside silica coating with $30{\mu}m$ $SiO_2$ + silanization + adhesive]; Group II-Ceramic Repair System (Ivoclar Vivadent) [etching with 37% phosphoric acid + Zirconia primer + adhesive]; Group III-Signum Zirconia Bond (Heraus) [Signum Zirconia Bond I + Signum Zirconia Bond II]. Composite resin was polymerized on each conditioned specimen. The shear bond strength was tested using a universal testing machine, and fracture sites were examined with FE-SEM. Surface morphology and wettability after surface treatments were examined additionally. The data of bond strengths were statistically analyzed with one-way ANOVA and Tamhane post hoc test (${\alpha}$=.05). RESULTS. Increased surface roughness and the highest wettability value were observed in the CoJet sand treated specimens. The specimens treated with 37% phosphoric acid and Signum Zirconia Bond I did not show any improvement of surface irregularity, and the lowest wettability value were found in 37% phosphoric acid treated specimens. There was no significant difference in the bond strengths between Group I ($7.80{\pm}0.76$ MPa) and III ($8.98{\pm}1.39$ MPa). Group II ($3.21{\pm}0.78$ MPa) showed a significant difference from other groups (P<.05). CONCLUSION. The use of Intraoral silica coating system and the application of Signum Zirconia Bond are effective for increasing the bond strength of composite resin to zirconia.