Mechanical Characterization of Nano-Structured Materials Using Nanoindentation

( Ju Young Kim ),( Sung Hoon Kim ),( Jung Suk Lee ),( Kyung Woo Lee ),( Dong Il Kwon ) 대한금속재료학회 ( 구 대한금속학회 ) 2006 METALS AND MATERIALS International Vol.12 No.3

The principal strengths of the nanoindentation technique, which is used extensively to measure the mechanical properties of nano/micro materials, are easy sample preparation and simple experimental method. Hardness and Young`s modulus are essential properties measured by nanoindentation; hardness corresponds to resistance to plastic deformation whereas Young`s modulus is related to elastic deformation. Two key difficulties arise in association with nanoindentation on small volumes: measurement accuracy and material response. Here we discuss the indentation size effect (ISE) considering tip bluntness and variation in hardness of nano-multilayers with a bilayer period, representative research on measurement improvement, and material response at nanoscales.

중ㆍ고년여성의 하지 근 기능과 요부 및 대퇴근 횡단면적의 상관관계

김창근,이수경,권영우,박정배 한국체육대학교 체육과학연구소 2001 국제학술대회논문집 Vol.20 No.1

The purpose of the present study was to investigate the relationship between isokinetic muscle function and muscle cross-sectional area (CSA). Twelve women participated in the present study, divided young (n=6, 23.7±1.9 year) and elderly women (n=6, 60.3±6.8 year). Isokinetic strength (power, strength, endurance) and CSA (psoas major and thigh muscles) measured with dynamometer and computerized tomograph, respectively. Cross-sectional area of psoas major muscle in elderly group revealed markedly smaller than in young group, but thigh muscle was not the case. Muscle CSA in young women correlated between power and endurance and psoas major muscle, as well as between muscle strength and CSA of thigh muscle. But no correlation occurred between strength and cross sectional area, except endurance which was highly correlated between CSA and endurance. In conclusion, aging decreases muscle function and CSA. Partially muscle strength correlated with muscle CSA in young women, but no correlation occurred in elderly women. Further study needed to elucidate the exact mechanism related to aging muscle with muscle density and neuromuscular function.

포커스 그룹을 이용만 임상간호사의 임파워먼트 경험에 관한 연구

권성복,염영희,권은경,이윤영 대한간호학회 간호행정학회 2007 간호행정학회지 Vol.13 No.4

Purpose: This study was to explore the empowerment experienced by hospital nurses. Methods: Focus group was used to gather data and open coding method suggested by Strauss and Corbin was used to analyze the data. Thirty-four nurses who have clinical experience of more than three years at three university hospitals were participated in this study. Results: Five categories were identified: Getting chances of opportunities to show personal capabilities and motivations, acknowledgement, support, recognition and delightfulness. The major sources of empowerment were the acknowledgement of patients and family, colleagues, supervisors. doctors, and other personnels in hospital. Conclusion: Focus groups could be an useful tool for empowerment research in nursing. further research will be needed to clarify the relationship among individual, group and organization.

신경회로망 제어기를 이용한 PID 파라미터 추정에 관한 연구

權重東,裵銀敬,金恩基,全基英,李承桓,吳鳳煥,李勳九,金容珠,韓慶熙 明知大學校 産業技術硏究所 2006 産業技術硏究所論文集 Vol.25 No.-

In this paper, supposed to solve these problem to PID parameters controller algorithm using ANN. In the proposed algorithm, the parameters of the controller were adjusted to reduce by on-line system the error of the speed of IM. In this process, EBPA NN was constituted to an output error value of an IM and conspired an input and output. The performance of the self-tuning controller is compared with that of the PH) controller tuned by conventional method (Ziehler-Nichols). The effectiveness of the proposed control method is verified thought the Matlab Simulink and experimental results.

광촉매를 이용한 셀룰로오스섬유의 기능화에 관한 연구 : 항균·소취성 및 자외선 차폐성을 중심으로 Focusing on Antibacterial activity, Deodorization & UV cut ability

권오경,문제기,손부헌,최영희 한국의류산업학회 2003 한국의류산업학회지 Vol.5 No.4

In this study, we measured the antibacterial activities, deodorization, UV cut ability, whiteness and SEM, according to the size(5 μm, 15 ?m) of ThiO₂, concentration(3%, 5%, 10%) and dipping temperature(50℃, 70℃) with using anatase type of TiO₂ photocatalyst. Photocatalyst is the substance which carries out functions, such as decomposition, removal, deodorization, antibacterial, etc. of a contaminant, in a place with light based on an oxidation-reduction reaction. The results of this study were as follow. Antibacterial activities are increased with increasing of the TiO₂'s concentration, and TiO₂ has high antibacterial activities for Staphylococcus aureus but it has low antibacterial activities for Klebsiella pneumoniae. The deodorization and UV cut ability is very good, therefore be able to get good effects with usingonly 3% of TiO₂. Every effects are increased by using small size of TiO₂ and high dipping temperature.

불소화계면활성제 함유 DPPC/Cholesterol 및 DPPG/Cholesterol 베지클의 BSA(bovine serum albumin)친화성 연구

권경옥,김명자,김현영 숙명여자대학교 자연과학연구소 1998 자연과학논문집 Vol.- No.9

본 연구에서는 항원(antigen). 항체(antibody) 등을 삽입시켜 자극반응성 베지클을 제조의 예비실험으로 대표적인 생체 단백질 BSA(bovine serum albumin)와 베지클의 친화도에 관해 알아보았다. DPPC(dipalmitoylphosphatidylcholine)/Chol, DPPG(dipalmitoylphos-Phatidylglycerol)/Chol,DPPC/Chol/FFS(ammonium pentadeca-fluorooctyrate)/FS(sodium bis(1H,1H,2H,2H-heptadecafluorodecyl)-2-sulfosuccinate), DPPG/Chol/ FFS/FS의 4종의 베지클을 제조하고, 제조된 4종의 베지클에 대해 column chromatography 법에 의해 BSA와의 흡착 여부를 확인했다. 실험 결과, 각 계의 베지클 입자크기는 BSA의 흡착으로 인해 감소하는 것으로 나타났고, 감소하는 정도는 DPPC/Chol와 DPPG/Chol에서 큰 것으로 나타났다. 반면, 제조된 계의 제타전위(ξ-Potential)값에는 거의 변화가 없었다. BSA와의 결합친화력의 비교에서는 DPPC/Chol. DPPG/Chol. DPPC/Chol/FFS/FS. DPPG/Chol/FFS/FS 순으로 낮아진다는 결과를 얻었다. 이들 실험결과에 바탕하여, 위의 4종의 베지클과 BSA와의 결합친화력에 대해 베지클의 표면전하와 베지클 막의 밀집성(compactness)이 영향을 미친다는 결론을 얻었다. The purpose of this study is to prepare a functional vesicle for the possible use as a biosensor. In this work, we have performed a preliminary experiment for biosensor, Four different systems of vesicle have been prepared with the composition of DPPC(dipalmitoylphosphatidylcholine)/Chol, DPPG (dipalmitoylphos-phatidylglycerol)/Chol, DPPC/Chol/FFS(ammonium pentadecafluoro-octyrate)/FS(sodium bis(1H,1H,2H,2H-heptadecafluorodecyl)-2-sulfosuccinate) and DPPG/Chol/FFS/FS. By use of column chromatography, it was found that BSA has been adsorbed onto the vesicle structure. The size of vesicle was found to decrease as adsorption occurs between the two species and the extent was greater in the systems of DPPC/Chol and DPPG/Chol. However, the δ-potential of the system remained essentially unchanged. The affinity of vesicle to BSA was found to decrease in the order of DPPC/Chol, DPPG/Chol, DPPC/Chol/FFS/FS and DPPG/Chol/FFS/FS. Based on these findings, it may be concluded that the affinity of vesicles onto BSA was affected by the surface charge and the compactness of vesicle.

옥정호수계에 있어서 화학적 및 생물학적 오염도 지표조사

권태영,강경홍,박기남 전주대학교 자연과학종합연구소 1997 전주대학교 자연과학연구소 학술논문집 Vol.10 No.3

A inveatigation in water system in Okjung lake for the pollution loading and self purification capacity, the nitrate concentration, as a pollution loading index, was 0.2-0.3mM in Sumjin river and Sangchi stream. Imsil stream was mainly pollution source in water system of Okjung lake. Nitrate concentration of Okjung lake was 0.06-0.1mM. This results was mean that the capacity of self-purification of Okjung lake have in reserve.

말초혈액에서 Tg mRNA에 대한 역전사 중합효소 연쇄 반응법의 갑상선 재발암의 분자생물학적 진단

권성일,박기룡,김현영,신채희,임영찬,최영식,박요한,이강대,장희경,이재화,염하용 대한내분비학회 2002 Endocrinology and metabolism Vol.17 No.4

연구배경: 갑상선암은 다른 조직에 발생한 암에 비해 비교적 천천히 자라므로 대부분 예후가 양호하지만, 일부에서는 주위 조직으로 침윤하거나 혹은 원격 전이로 인하여 치명적인 결과를 초래할 수 있다. 갑상선전절제술 및 131^I 제거술 후 경과 관찰시 갑상선암의 재발과 전이의 진단에 있어 131^I 스캔과 혈청 Tg의 측정이 현재 임상에서 가장 많이 이용되고 있으나 이 방법에는 여러 가지의 결점이 있다. 최근 Tg mRNA에 대한 RT-PCR법을 이용한 여러 연구결과는 131^I 스캔과 혈청 Tg 측정의 결점을 보완할 수 있는 좋은 보조적인 진단법으로 이용할 수 있을 가능성을 제시하였다. 이에 말초혈액에서 측정한 Tg mRNA에 대한 RT-PCR법이 갑상선 절제술 및 방사성요드 치료 후 갑상선암의 재발 및 전이 유무의 진단에 유용한가를 알아보고자 이 연구 시행하였다. 방법: 분화된 갑상선암으로 진단된 후 갑상선전절제술을 시행받고 방사성요드 치료를 받은 환자 중 현재까지 한차례에 이상 추적 방사성요드 전신 스캔을 시행하고 추적관찰이 가능했던 유두선암 35예, 여포선암 5예를 대상으로 연구를 시행하였다. 대상군은 131^I 스캔 소견상 음성인 군(Group Ⅰ), 잔여조직이 있는 군(Group Ⅱ), 국소전이가 있는 군(Group Ⅲ), 및 원격전이 군(Group Ⅳ)으로 구분하였다. 정상 대조군은 갑상선질환이 없는 10예의 건강인으로 하였다. 대상환자의 말초혈액을 이용한 Tg mRNA에 대해 특이적인 primer를 이용하여 RT-PCR 및 nested RT-PCR을 시행하였다. 결과: 본 연구 결과는 다음과 같다. 1) 131^I 스캔 소견상 음성인 군 21예 중 1예에서 Tg가 양성소견을 보였다. Anti Tg Ab가 양성인 4예 모두 Tg가 음성을 보였다. 잔여조직이 있거나 국소전이 및 원격전이를 보인 군 19예 중 Tg가 양성인 경우는 4예였으나, Tg mRNA는 전예에서 양성이었다. 2) 131^I 스캔에서 국소 및 원격전이 소견을 보인 8예 중 4예에서 Tg가 음성으로 131^I 스캔과 혈청 Tg 사이에 불일치 소견을 보였다. 3) 말초혈액에서 특이적인 primer를 이용하여 RT-PCR 및 nested RT-PCR을 시행한 결과 대상군 40예 및 정상 대조군 10예 모두에서 Tg mRNA가 양성을 보였다. 결론: 본 연구에서 갑상선 절제술 및 방사성요드 치료 후 갑상선암의 재발 및 전이 유무를 평가함에 있어 역전사 중합효소 연쇄 반응법을 이용한 Tg mRNA 측정의 의의는 재평가되어야 한다고 생각된다. Background: Differentiated thyroid cancer is the most common endocrine malignancy. Despite advances in the treatment of thyroid cancer, disease recurrence and metastasis may occur in as many as 20% of patients, and so continues to pose major problems in its clinical management. Serum thyroglobulin (Tg) measurements, by immunoassay, are used to detect residual or recurrent thyroid cancer following thyriod ablation. However, the usefulness of immunoassay is limited by both the requirement for thyroid hormone withdrawal, to attain optimal test sensitivity, and interference by the antithyroglobulin antibody (Anti-Tg Ab). Recent studies have reported the clinical usefulness of reverse transcription-polymerase chain reaction (RT-PCR) detection of Tg mRNA in the peripheral blood of patients with differentiated thyroid carcinomas. We performed this study to evaluated the usefulness RT-PCR of Tg mRNA in peripheral blood of patients with thyroid carcinoma following a total thyroidectomy and radioiodine ablation therapy. Methods: Forty cases that underwent a total thyroidectomy and radioiodine ablation therapy were included in this study. Of the 40 patients, 35 were papillary carcinomas and 5 were follicular carcinomas. Ten normal control subjects were also studied. Tg mRNA was extracted. Then RT-PCR and nested RT-PCR, were run with specific Tg primers. Concurrently, DNA sequencing of the isolates was carried out to prove the isolates were identical to the nucleotide sequence of the Tg. Results: The Tg was detected in 4 of 19 patients, with either a residual thyroid bed, or metastasis, on a 131^I whole body scan and in 1 of 21 patients with a negative radioiodine scan. Surprisingly, the Tg mRNA was detected in all the patients and normal controls. Conclusion: From our results we can not recommend Tg mRNA, detected by RT-PCR in peripheral blood, as a tumor marker superior to that of the Tg serum level. We consider an intensive re-evaluation of the method is required before considering its clinical applications (J Kor Soc Endocrinol 17:501∼513, 2002).

소아 조갑진균증에서 Itraconazole 주기요법의 치료효과

권경술,이재봉,진현우,오창근,장호선,임재영 대한의진균학회 2003 대한의진균학회지 Vol.8 No.4

체중감량이 유도선수의 Renin, 면역기능 및 유·무산소 운동능력에 미치는 영향

권영우,전승훈,김진해,민경선,민진아 한국스포츠리서치 2001 한국 스포츠 리서치 Vol.12 No.4

The purpose of this study was to investigate the effect of short terms weight reduction period on body composition and body fluid. Seven Judo athletes (21±1.21 yrs) were matched and randomly placed. Body weight reduction period consists of 7 day. Each groups reduced body weight by 3%(2th day from pre weight reduction), 5%(4th day from pre weight reduction, 7%(7th day) and investigated the recovery period on 3 hour after breakfast, lunch, and 1day, 2day after 7% body reduction. Weight reduction reduced weight during weight reduction period then returned to baseline during recovery(p<.05) and decreased LBM, electrolyte, and immune function and then increased in recovery period to baseline. In conclusion, weight reduction of Judo athletes caused the change biological variable and performance and STWR may detrimental effects body' homeostasis.