Improvement of interlaminar properties of carbon fiber‑reinforced epoxy composites using aluminum trihydroxide

Dong‑Jun Kwon,Sung‑Min Park,Il‑Jun Kwon,Joung‑Man Park,Euigyung Jeong 한국탄소학회 2019 Carbon Letters Vol.29 No.2

This study provides an economical and effective method to improve the interlaminar properties of carbon fiber-reinforced polymers (CFRPs) using aluminum trihydroxide (ATH) microparticles. ATH microparticles are cheap and are expected to show good affinity to epoxies in the matrix and sizing agents of the carbon fibers owing to the presence of three hydroxyl groups. In addition, ATH particles are reported to improve the mechanical properties of polymers when used as the reinforcement. In this study, ATH microparticles of various sizes, 1.5, 10, and 20 μm, were used to improve the interlaminar properties of the CFRPs. ATH particles with a size of 1.5 μm improved the tensile properties of the ATH/epoxy resin and did not significantly alter the curing behavior. The interfacial adhesion between the carbon fiber and the epoxy resin was also improved, and the impregnation of the resin mixture remained similar to that of the neat resin, resulting in no significant void and defect formation. Considering the above results, the resulting 1.5 μm ATH-reinforced CFRP showed improved interlaminar properties compared to CFRP without ATH. However, 10 and 20 μm ATH-reinforced CFRPs showed deteriorated interlaminar properties due to the diminished tensile properties of the resin itself and resin impregnation, which resulted in more voids and defects, despite the interfacial adhesion between the fiber and the matrix resin.

NGS_SNPAnalyzer: a desktop software supporting genome projects by identifying and visualizing sequence variations from next-generation sequencing data

Dong‑Jun Lee,Taesoo Kwon,Chang‑Kug Kim,Young‑Joo Seol,Dong‑Suk Park,Tae‑Ho Lee,Byung‑Ohg Ahn 한국유전학회 2020 Genes & Genomics Vol.42 No.11

Background Sequence variations such as single nucleotide polymorphisms are markers for genetic diseases and breeding. Therefore, identifying sequence variations is one of the main objectives of several genome projects. Although most genomeproject consortiums provide standard operation procedures for sequence variation detection methods, there may be differencesin the results because of human selection or error. Objective To standardize the procedure for sequence variation detection and help researchers who are not formally trainedin bioinformatics, we developed the NGS_SNPAnalyzer, a desktop software and fully automated graphical pipeline. Methods The NGS_SNPAnalyzer is implemented using JavaFX (version 1.8); therefore, it is not limited to any operatingsystem (OS). The tools employed in the NGS_SNPAnalyzer were compiled on Microsoft Windows (version 7, 10) andUbuntu Linux (version 16.04, 17.0.4). Results The NGS_SNPAnalyzer not only includes the functionalities for variant calling and annotation but also providesquality control, mapping, and filtering details to support all procedures from next-generation sequencing (NGS) data to variantvisualization. It can be executed using pre-set pipelines and options and customized via user-specified options. Additionally,the NGS_SNPAnalyzer provides a user-friendly graphical interface and can be installed on any OS that supports JAVA. Conclusions Although there are several pipelines and visualization tools available for NGS data analysis, we developedthe NGS_SNPAnalyzer to provide the user with an easy-to-use interface. The benchmark test results indicate that theNGS_SNPAnayzer achieves better performance than other open source tools.

한약과 와파린 병용의 상호작용과 안전성에 대한 연구

권동현 ( Dong Hyun Kwon ),김호준 ( Ho Jun Kim ),이명종 ( Myeong Jong Lee ),송미영 ( Mi Young Song ) 한방재활의학과학회 2010 한방재활의학과학회지 Vol.20 No.2

Objectives: The purpose of this study is to investigate interaction and safety in administering herb-medicine with warfarin. Methods :For this study, we selected 19 patients who have been taking warfarin, from the ones that have been transferred from western hospital to oriental hospital. During their stay in the oriental hospital, we gave herb-medicine in addition to warfarin. Then we gathered informations and data on sex, age, main indications, and International Normalized Ratio(INR) values of selected patients through Electronic Medical Records(EMR) of Dong-Guk university hospital. Accordingly, we compiled all of the above data for a period of 10 days prior and 10 days post admission(western hospital period and oriental hospital period, respectively)Results and Conclusions :The statistical analysis of the data have revealed that there was no significant change of INR values after giving herb-medicine with warfarin(p=0.586). The result shows that administration of herb-medicine with warfarin is safe and has little drug interaction. However, this study was carried out on small sample size and the interaction with other drugs and various kinds of herb-medicine was not considered. Although we attained a restrictive result from this study, we are able to suggest the safety about co-administration of herb-medicine and warfarin.

프리미돈의 한국인에서의 생체이용율시험

권광일,윤민혁,윤희열,박희찬,권준택,심희옥,김동출 충남대학교 약학대학 의약품개발연구소 2004 藥學論文集 Vol.19 No.-

A reversed phase HPLC method was developed and validated for the determination of primidone in human plasma. Propylthiouracil was used as an internal standard. Calibration curves were linear in the concentration range of 10-120 ng/㎖. The coefficient of variation of the intra- and inter-day precision were below 15%. The coefficient of variation of the accuracy were below 15% in the concentration range investigated. A bioavailability study was performed using the validated HPLC method. Twenty four healthy human male volunteers were orally administered 20 mg of primidone. The pharmacokinetic parameters were calculated using WinNonlin. The mean values of AUC_(LAST) was 85.0±17.7 ㎍ hr/㎖, C_(max) was 4.22±1.04 ㎍/㎖, T_(max) was 1.85±1.13 hr, t_(1/2) was 17.7±2.4 hr. The pharmacokinetic parameters and the HPLC method can be used for the desigm of bioequivalence study of primidone.

소목 천연 염색에 관한 연구 Ⅰ : 정제 알루미늄 화합물들의 매염효과에 대하여 Mordanting Effect of Purified Aluminum Compounds

권민수,전동원,최인려,김종준 服飾文化學會 2004 服飾文化硏究 Vol.12 No.5

Currently, as mordants, heavy metals are being used in dyeing process in order to improve dye uptake and dye fastness. These chemicals, however, are mostly harmful to human body and the environment along with the pollution by effluent. Traditionally, rice straw ash solution, lime, etc. have been used as mordants in order to improve the effects on dye uptake and color fastness of dyestuffs. The study of natural mordants would, therefore, be vital to the development and succession of our traditional dyeing methods. In this study, as a preliminary step toward the use of rice straw ash solution for the nautral dyeing using Caesalpinia sappan, several aluminum compounds were employed as mordants. When the purified aluminum compounds were used, on the basis of unmordanted cotton fabric, the WS values of the pre-mordanted and simultaneously mordanted fabrics increased by 2 or 3 times, while those of the post-mordanted fabrics decreased.

후방순환계 뇌동맥류의 임상분석

임동준,이훈갑,정흥섭,김봉룡,권택현,이기찬,서중근 대한신경외과학회 1998 Journal of Korean neurosurgical society Vol.27 No.11

한국인에서의 CYP2C19 유전자형의 다형성

권준택,김형기,손동렬,염윤기 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.1

The S-mephenytoin 4'-hydroxylase (CYP2C19) metabolizes a number of clinically used drugs and shows a marked interethnic difference in the incidence of the poor metabolizer (PM). In the present study, we genotyped 215 healthy unrelated Koreans (64 females, aged 20-41 yr, residing in Chungcheong province) for functionally defective alleles, CYP2C19_(m1) and CYP2C19_(m2). Detection of the normal (CYP2C19_(wt)) and defective alleles was performed by polymerase chain reaction/restriction enzyme analysis. The genomic DNA was isolated from peripheral blood. The allelic frequencies of the wild-type (CYP2C19_(wt)) and CYP2C19_(m1) were 72.6% and 27.4%, and the wild-type (CYP2C19_(wt)) and CYP2C19_(m2) were 85.1% and 14.9%, respectively. For each CYP2C19_(m1) and CYP2C19_(m2), the observed numbers of three genotypes were similar to those calculated in accordance with the Hardy-Weinberg equation. The frequencies of homozygotes for CYP2C19_(m1), CYP2C19_(m2) and compound heterozygotes were 9.7%, 2.8% and 4.2%, respectively. The mutants of CYP2C19 were identified in 36 subjects (16.7%). These results suggest that frequency of mutants of CYP2C19 in Koreans resembled the Orientals rather than Caucasians.

취학전 아동의 체력 실태와 평가

권영옥,김동권,민춘기,이용인,전종귀,진윤수,홍성표 忠南大學校體育科學硏究所 1995 體育科學硏究誌 Vol.13 No.1

The purpose of this study was analyze children's Physical Fitness and basic rate by observing the change in the heart rate of the 1230 children of five of six years of age. Following conclusions were obtained The muscular strength was relatively low according to places. And the muscular strength of boys was higher than that of girls. The flexibility of girls was higher than that of boys according to places and sexes. The muscular endurance, power, balance and agility of boys were higher than those of girls according to places and sexes. Thus the development of physical fitness was improved with their ages, the physical fitness for physique seemed rather low. So the programs of physical plays for children's physical fitness ought to be developed and physical play showed to be done at kindergarten school.

평면에서 형상정보를 갖는 물체의 접촉 해석

전경진,손정현,강동권 동의공업대학 2001 論文集 Vol.27 No.1

This paper presents a method for calculating contact force of any shaped rigid bodies on plane. Every integration time step, the proposed method finds expected contact point on their outlines and then calculates penetration and contact force. This paper is using the continuous analysis method to calculate contact force. To get the accurate expected contact point on their outlines the new algorithm is developed. Through the comparison with DADS, we can prove the accuracy of the proposed algorithm.

[18F]FDG PET을 이용한 강박증 환자에서 뇌 포도당 대사의 이상에 관한 연구

권준수,이동우,이재성,최정임,이동수,정준기,조맹제,이명철,류인균 대한신경정신의학회 2000 신경정신의학 Vol.39 No.2

연구목적: 강박증에 대한 기능적 뇌영상 연구들에서 강박증 환자들의 안와전두엽과 미상핵의 대사율 증가 소견이 비교적 일과되게 발표되어 왔으며, 전두-피질하 회로의 이상이라는 이론이 수립되기도 하였다. 그러나 기존의 연구들은 강박증의 유병기간에 따른 구분없이 시행된 연구였고, 영상분석 방법에 있어서도 관심영역 방법을 이용했다는 한계를 지니고 있다. 본 연구의 목적은 첫째, 강박증의 유병기간에 따라 환자군을 구분하여 PET 영상소견을 분석함으로써 유병 기간에 따른 차이가 있는지를 조사하였으며, 둘째, 강바증 환자의 포도당 양전자방출 단층촬영(18-Fluor-deoxyglucose Positron Emission Tomography : FDG-PET) 영상분석에 통계적 매개변수 지도법(Statistical Parametric Mapping : SPM)을 이용함으로써 강박증의 병인기전 및 강박증상과 뇌기능 간의 관계를 명확히 규명하고자 하였다. 방법: 구조적 면담도구(Structured clinical interview for DSM-IV : SCID-IV)를 적용하여 진단된 12명의 강박증 환자들과 10명의 정상 대조군에 대해 FDG-PET을 촬영하여 SPM으로 분석하였다. PET 촬영 전 적어도 4주 동안에는 약물복용을 하지 않은 상태였다. 결과: 1) 환자군과 대조군의 비교 : 강박증 환자군은 대조군에 비해 양측 두정 영역의 대사율이 유의하게 감소되어 있었으며(P<0.01). 대사증가를 보인 영역은 없었다. 강박증의 유병기간이 10년 이상인 만성강박증 환자 4명은 양측 안와전두엽에서 유의한 대사증가 소견을 보였으며(P<0.01), 양측 두정영역에서 유의한 대사감소 소견을 보였다 (P<0.01), 유병기간이 10년 이하인 환자에서는 전체 환자군의 분석에서와 마찬가지로 대조군에 비해 유의한 대사증가 소견을 보인 영역은 없었으며, 양측 두정엽 부위에서 유 의한 대사 감소 소견을 보였다.(P<0.01). 2) 강박증상의 심각도와의 상관관계 분석 : 우측 두정엽의 대사율은 강박장애 척도 점수와 유의한 음의 상관관계를 보였으며(p<0.01), 양측 시상 영역의 대사율은 예일-브라운 강박장애 척도의 강박장애척도 점수와 유의한 양의 상관관계(p<0.01)를 보였다. 결론: 본 연구는 결과는 기존의 연구들에서 보고된 안와전두엽의 대사 증가 소견이 강박증의 만성화로 인해 나타나는 2차적 장애이며, 두정엽의 대사 저하가 보다 1차적인 장애일 가능성을 시사한다. Baxter가 수립한 전두-피질하 회로 이론은 두정엽의 이상을 포함하는 전두-두정엽 복합체 이론으로 확장되어야 할 것이다. Objectives: Functional imaging studies on obsessive-compulsive disorder(OCD) subjects have repeatedly reported increased metabolism in orbitofrontal lobes and caudate nucleus, resulting in the "frontal-subcortical" circuit abnormality theory. Limitations of the previous studies to date include little consideration for the duration of illness, and the use of regions of interest methods, as an image analysis method. Our study objectives are 1) to include the duration of illness as an important study variable, and 2) to use Statistical Parametric Mapping(SPM) method in order to tap relations between the brain function and the psychopathology and symptoms of OCD. Methods: The [18] fluorodeoxyglucose positron emission tomography(FDG-PET) scans of OCD subjects and normal comparison subjects, as diagnosed by the Structured Clinical Interview for DSM-IV(SCID-IV), were analyzed using SPM. Results: 1) Comparison of OCD and control groups : OCD subjects had significantly decreased metabolism in both parietal lobes and didn't have any areas of increased metabolism in comparison to comparison subjects(p.<0.01). four OCD subjects with the illness duration of 10 years or longer, had significantly increased metabolism in both orbitofrontal lobes<p<0.01). OCD subjects whose illness duration is shorter than 10 years didn't have any areas of increased metabolism and had significantly decreased parietal lobe metabolism, as in the analyses of all subjects(p<0.01). 2) Correlation analysis between areas and symptom severity : Metabolism of both thalamic sreas showed significant positive correlation with Yale-Brown Obsessive-Compulsive Scale(Y-BOCS) scores(p<0.01). Metabolism of right parietal area showed significant negative corre lation with Y-BOCS scores(p<0.01). Conclusions: The current findings suggest that the increased metabolism in orbitofrontal lobe, previously rported, may be a secondary phenomenon due to the extended illness dur- ation and that decreased metabolism in the parietal lobes are primary abnormality in OCD subjects. Thus Baxter's fronto-subcortical circuit theory should be extended into "fronto-pari-etal" complex theory, which includes the parietal lobes.