• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
• /
• pp.942-945
• /
• 2003

Nerve gas sensor based on tin oxide was fabricated and its characteristics were examined. Target gas was dimethylmethylphosphonate($C_3H_9O_3P$, DMMP) that is simulant gas of nerve gas. Sensing material was $SnO_2$ added ${\alpha}-Al_2O_3$ with $4{\sim}20wt.%$ and was physically mixed. And then it was deposited by screen printing method on alumina substrate. Sensor device was consisted of sensing electrode with interdigit(IDT) type in front and heater in back side. Total size of device was $7{\times}10{\times}0.6mm^3$. Crystallite size of fabricated $SnO_2$ were characterized by X-ray diffraction(XRD, Rigaku) and morphology of the $SnO_2$ powders was observed by a scanning electron microscope(SEM, Hitachi). Fabricated sensor was measured as flow type and sensor resistance change was monitored real time using LabVIEW program. The best conditions as added $Al_2O_3$ amounts and operating temperature changes were 4wt.% and $300^{\circ}C$ in DMMP 0.5ppm, respectively. The sensitivity was over 75%. Response and recovery times were about 1 and 3 min., respectively. Repetition measurement was very good with ${\pm}3%$ in full scale.

• 복식
• /
• 제61권3호
• /
• pp.139-152
• /
• 2011

This research explores the idea of digilog for fashion; it would help to conclude the uncertain mixed-phenomena and words as a neologism and find a fundamental concept that would be a reference for a lot of uncertain new words that have been occurring even this year. Furthermore, this research is aimed at analyzing how digilog has been reflected on the contemporary fashion and directing the ways towards the future of fashion. The digilog fashion design is the expression of a combination of opposite extremes, that is to say the combination of a paradoxical mix and directly-opposed elements. The outward expression of fashion design with digilog can be classified into several ways. First of all, it tends to use the elements of paradoxical expression; for example, applying high-technology to express a primitive and natural material. The analog expresses unprocessed. Secondly, using high-tech machine to express the texture of handicraft or rough embroidery. Lastly, digital printing(DTP) is applied to enlarge the several or the whole parts of a natural object or sensitivity. As a result of the analysis, the inside view of the contemporary fashion with digilog delineate followings; it is the attitude that claims to go back to the past and accepts the combination of nature and high-technology to get calmness in the rapidly changing modern world. And it is the will to fly from the utterly exhausted reality through the recurrence of the past when there used to be a lot of energies and used to live in affluence.

• 센서학회지
• /
• 제27권4호
• /
• pp.232-236
• /
• 2018

A radiation detection sensor was developed and characterized by combining three types of CsI(Tl) scintillators and an array-type SiPM to detect the radioactive contamination of discharged water in real time. The characterization results showed that type 3 exhibited the most desirable characteristics in response linearity (R-square: 0.97889) according to detection sensitivity and incident radiation dose. Furthermore, in terms of spectral characteristics, type 3 exhibited 16.54% at 0.356 MeV (the emission gamma ray energy of $^{133}Ba$), 10.28% at 0.511 MeV (the emission gamma ray energy of $^{22}Na$), 9.68% at 0.356 MeV (the emission gamma ray energy of $^{137}Cs$), and 2.55% and 4.80% at 1.173 MeV and 1.332 MeV (the emission gamma ray energies of $^{60}Co$), respectively. These measurements confirmed the good energy characteristics. The results were used to evaluate the spectral characteristics and energy linearity in a mixed source using type 3 with the best detection characteristics. It was confirmed that the gamma ray peaks of $^{133}Ba$, $^{22}Na$, $^{137}Cs$, and $^{60}Co$ were well resolved. Moreover, it was confirmed that R-square, which is an indicator of energy linearity, was 0.99986. This indicates a good linearity characteristic. Based on this study, further commercialization studies will contribute to measurements in real time and to the management of the contamination caused by radioactive wastewater or radioactive material leakage, which originate from facilities that use radioactive isotopes or care facilities.

• 한국물환경학회지
• /
• 제32권6호
• /
• pp.670-699
• /
• 2016

In this study, 16 antibiotics were selected from among the top 30 veterinary antibiotics sold in South Korea in 2014, as well as from among the pharmaceuticals targeted by EPA method 1694, in order to review analytical methods for the detection of trace levels of antibiotics in environmental samples: surface water, soils, animal origin foods, and manures. LC-MS/MS was heavily used. In the chromatography for the detection of the selected antibiotics, the $C_{18}$ column was mostly used at the temperature of $30{\sim}40^{\circ}C$. Water and methanol/acetonitrile were commonly chosen as a nonpolar and a polar mobile phase, respectively. Gradient elution was applied to separate multiclass antibiotics. Volatile additives, such as formic acid, acetic acid, and ammonium acetate were mixed with the mobile phase to improve the ionization efficiency of analytes and the sensitivity in MS detection. Electrospray ionization (ESI) was widely used in the LC-MS/MS and positive ionization was preferred to determine the selected antibiotics. A protonated $[M+H]^+$ molecule was selected as a precursor ion, and its two transitions were analyzed, one for quantitative measurement and the other for confirmation. This study reviewed linearity of the calibration curve, recovery, repeatability, method detection limits (MDLs), and method quantification limits (MQLs) for each target compound used to validate the developed analytical methods.

• 한국가스학회지
• /
• 제17권2호
• /
• pp.50-58
• /
• 2013

공정플랜트에는 다양한 배관이 고압, 고온의 인화성, 폭발성 물질을 이송하고 있다. 잦은 설계 변경 및 증설 등으로 복잡한 형상으로 배관이 형성되어 있는 경우가 많으나 배관의 구조가 단순하여 실제 위험성에 비해 안전 관리가 부족한 경우가 많다. 본 연구에서는 국내 한 업체에서 부생가스를 연료로 사용하던 배관을 설계 변경하여 천연가스와 혼합하여 사용하도록 사례를 활용하여, 배관의 안전성을 평가 하는 방법을 예시하였다. 배관의 설계 변경 후 안전성을 ASME 기준에 따라 재평가하고, 배관의 주요 관리부위를 결정하는 방법을 제시하였다. 배관의 분기 및 루프 등이 다수 복잡하게 연결되어있는 가스혼합용 믹싱드럼 배관 시스템을 대상으로 해석하였다. 배관의 주요부위 응력 민감도를 이해하기 위해 배관의 지지대 구속조건 및 외부 온도를 변화시켜 가면서 이들의 영향을 연구하였다. 또한 부생가스가 포함하고 있는 수소가스에 의한 손상 가능성에 대해서도 논의하였다.

• 한국양식학회지
• /
• 제4권1호
• /
• pp.67-71
• /
• 1991

돌연변이유기를 통한 유용견전형질의 해조류품종을 개발하기 위해 화학적돌연변이유발원인 Ethyl-methanesulphonate(EMS)에 대한 구멍갈파래(Ulva pertusa Kjellman) 엽체의 감수성을 검토하여 효과적인 돌연변이유기조건을 찾고자 하였다. EMS를 처리한 배지에 엽체를 생장시키며 변이를 유발시키고자 하였을 때, $0.05{\%}$와 $0.025{\%}$의 EMS 처리구에서 각각 $100{\%}$와 약 $20{\%}$의 생장억제가 일어났다. 한편 고농도의 EMS액에 엽체를 일정시간 침적한 후 정상배양함으로서 변이를 유발코자 했을 때, $1.0{\%}$ EMS액에 40분과 $0.5{\%}$ EMS액에 80분 처리한 경우 각각 $100{\%}$와 약 $10{\%}$의 생장억제가 일어났다. EMS 처리된 엽체는 생장형과 체색이 모체와 전혀 다른 변이체로 나타나기도 하였는데 이들의 polypeptide 일부에 변화가 있음이 SDS-PAGE로 조사되었다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권1호
• /
• pp.425-429
• /
• 2016

Background: Dermatoscopy can be applied to diagnose pigmented skin lesions. The aim of the present study was to compare dermatoscopic and histopathologic results in basal cell carcinoma (BCC) and melanocytic nevus of theface. Materials and Methods: In an analytical-descriptive study, 61 patients suspected of BCC or melanocytic nevi of face were randomly selected. The skin lesions of patients were evaluated with dermatoscopic method from February 2012 to February 2014 and results were compared with pathological features of samples. Results: In this study, mean age of patients was $49.5{\pm}18.9$. Some 25 (41%) were men and 36 (59%) were women. In 27 cases (44.3%) there was diagnosis of melanocytic nevus, in 28 cases (45.9%) diagnosis of BCC, and in 3 cases (4.9%) there was mixed diagnosis. The relationship between patients' gender and dermatoscopic diagnosis of the patients was statistically significant (P=0.001). For BCC the sensitivity and specificity of dermatoscopic method were 100% and 97% respectively and for melanocytic nevi 96.4% and 97%. Conclusions: Dermatoscopic study not only can be helpful in improving clinical diagnosis while guiding missed malignant lesions to pathologic evaluations, but also could be useful in evaluating further suspicious or recurrent cases.

• Asian-Australasian Journal of Animal Sciences
• /
• 제28권6호
• /
• pp.788-795
• /
• 2015

Two dimensional-fluorescence difference gel electrophoresis (2D DIGE) is an emerging technique for comparative proteomics, which improves the reproducibility and reliability of differential protein expression analysis between samples. The purpose of this study was to investigate bovine pregnancy-specific proteins in the proteome between bovine pregnant and non-pregnant serum using DIGE technique. Serums of 2 pregnant Holstein dairy cattle at day 21 after artificial insemination and those of 2 non-pregnant were used in this study. The pre-electrophoretic labeling of pregnant and non-pregnant serum proteins were mixed with Cy3 and Cy5 fluorescent dyes, respectively, and an internal standard was labeled with Cy2. Labeled proteins with Cy2, Cy3, and Cy5 were separated together in a single gel, and then were detected by fluorescence image analyzer. The 2D DIGE method using fluorescence CyDye DIGE flour had higher sensitivity than conventional 2D gel electrophoresis, and showed reproducible results. Approximately 1,500 protein spots were detected by 2D DIGE. Several proteins showed a more than 1.5-fold up and down regulation between non-pregnant and pregnant serum proteins. The differentially expressed proteins were identified by MALDI-TOF mass spectrometer. A total 16 protein spots were detected to regulate differentially in the pregnant serum, among which 7 spots were up-regulated proteins such as conglutinin precursor, modified bovine fibrinogen and IgG1, and 6 spots were down-regulated proteins such as hemoglobin, complement component 3, bovine fibrinogen and IgG2a three spots were not identified. The identified proteins demonstrate that early pregnant bovine serum may have several pregnancy-specific proteins, and these could be a valuable information for the development of pregnancy-diagnostic markers in early pregnancy bovine serum.

• 대한기계학회논문집A
• /
• 제40권3호
• /
• pp.275-280
• /
• 2016

본 연구에서는 코일스프링의 동적 거동 분석을 위해 스프링 릴리즈 시험기를 설계하고 시험을 실시하였다. 시뮬레이션을 위해 집중 매개변수 스프링모델을 개발하였다. 실험계획법을 이용하여 코일스프링의 설계변수들을 최적화하였다. 2수준의 요인배치법을 사용하여 설계변수들의 민감도와 교호작용을 분석하였다. 민감도와 교호작용 분석결과를 통해 설계변수의 수준을 재배열하였다. 혼합수준 요인배치법을 이용하여 설계변수를 최적화 하였다. 최적설계 결과에 따르면, 스프링 조작기의 성능이 2.90 % 개선되었다.

• 한국도로학회논문집
• /
• 제19권2호
• /
• pp.127-135
• /
• 2017

PURPOSES: The objective of this study is to evaluate the effect of anti-stripping on asphalt mixtures constituting anti-stripping agents. METHODS : Based on the literature review, asphalt mixture added with anti-stripping agents was prepared, and these asphalt mixtures were evaluated for anti-stripping properties for each anti-stripping agent through various lab tests, namely, tensile strength ratio (TSR), dynamic immersion test, uniaxial compression test, and indirect tensile strength test (IDT). The liquid anti-stripping agents used in the lab test were premixed with each asphalt binder (PG 64-22, PG 76-22) before being mixed with the aggregate. RESULTS :The result of the TSR test revealed that the effect of anti-stripping was highest when hydrated lime and liquid anti-stripping agent W were added. The correlation coefficient $R^2$ between the TSR result and cohesion ratio is 0.99, which indicates that the sensitivity of the TSR to moisture damage is reliable from the mechanical point of view. The covering ratio of the asphalt binder to the liquid anti-stripping agent W was determined to be higher than that to the other liquid anti-stripping agents. CONCLUSIONS :It is considered that the improved moisture resistance of asphalt mixture as a result of the use of anti-stripping agents can reduce the incidence of various pavement damages such as portholes caused by stripping, and the performance life of the asphalt road pavement can be prolonged.