• Transactions on Electrical and Electronic Materials
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• 제18권2호
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• pp.78-88
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• 2017

Cantilever beam MEMS piezoelectric accelerometers are the simplest and most widely used accelerometer structure. This paper discusses the design of a piezoelectric accelerometer exclusively for SHM applications. While such accelerometers need to operate at a lower frequency range, they also need to possess high sensitivity and low noise floor. The availability of a simple model for deflection, charge, and voltage sensitivities will make the accelerometer design procedure less cumbersome. However, a review of the open literature suggests that such a model has not yet been proposed. In addition, previous works either depended on FEM analysis or only reported on the fabrication and characterization of piezoelectric accelerometers. Hence, this paper presents, for the first time, a simple analytical model developed for the deflection, induced voltage, and charge sensitivity of a cantilever beam piezoelectric accelerometer.The model is then verified using FEM analysis for a range of different cases. Further, the model was validated by comparing the induced voltages of an accelerometer estimated using this model with experimental voltages measured in the accelerometer after fabrication. Subsequently, the design of an accelerometer is demonstrated for SHM applications using the analytical model developed in this work. The designed accelerometer has 60 mV/g voltage sensitivity and 2.4 pC/g charge sensitivity, which are relatively high values compared to those of the piezoresistive and capacitive accelerometers for SHM applications reported earlier.

• Archives of Pharmacal Research
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• 제20권1호
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• pp.46-52
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• 1997

To obtain more sensitive immunoassay for methamphetamine (MA) determination, the optimum condition of enzyme-linked immunosorbent assay (ELISA) was investigated in regard to immunogens, antibody purification methods and coating tracers. Activated MA, N-(4-aminobutyl)methamphetamine (4-ABMA), was conjugated with bovine serum albumin (BSA) or keyhole limpet hemocyanin (KLH) and used as immunogen. The antibodies were purified by protein G chromatography or various immunoaffinity chromatography-linked MA-protein ligands, such as MA-BSA, MA-KLH or MA-ovalbumin (OVA). Each purified antibody was characterized by means of sensitivity and cross-reactivity using the three MA-protein coating tracers, MA-BSA, MA-KLH and MA-OVA. The best sensitivity of each antibody was acquired with the MA-OVA tracer although the tracer concentration and the antibody titer level at optimum condition were varied. The antibody with high titer level did not always yield good sensitivity. At optimum condition, immunoaffinity chromatography-purified antibodies were better for sensitivity and for specificity than protein G-purified antibodies. The cross-reactivity of the purified antibodies seemed to be affected by immunogen structure and showed somewhat different patterns according to the immunoaffinity ligand utilized. These data show that the antibody purification method as well as choice of coating tracer and immunogen is essential for the sensitivity and specificity of EIA; the optimum condition for assay should be discovered using various methods and combinations.

• 한국자기학회지
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• 제10권6호
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• pp.310-317
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• 2000

먼지 입자에 의한 thermal asperity(TA)써 발생은 드라이브의 신뢰성에 큰 영향을 미친다. 본 논문에서는 드라이브의 입자 분사 시험 등을 통하여 헤드 및 디스크의 TA민감도를 분석하고 TA발생의 중요 인자들을 고찰하였다. 헤드의 TA 민감도는 MR 및 GMR 센서의 재질 및 특성에 많은 영향을 받으며 특히 바이어스 전류가 증가함에 띠라 TA 민감도는 증가한다. 한편 슬라이더의 ABS 형태를 적절히 설계 함으로서 TA를 어느 정도 감소시킬 수 있다. 디스크의 경우 디스크 카본 overcoat층의 scratch저항력을 증가시킴으로써 TA의 발생을 감소시킬 수 있다. 그러나 먼지 입자가 디스크 표면에 부착되는 정도를 결정하는 표면에너지는 TA 발생에 거의 영향을 미치지 않는다. 이는 TA 발생을 초래하는 먼지 입자의 크기가 1-2 $\mu\textrm{m}$로서 디스크 표면의 윤활막에 의한 모세관력이 너무 커서 입자들이 디스크표면으로부터 이탈할 수 없기 때문이다

• The Plant Pathology Journal
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• 제36권3호
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• pp.218-230
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• 2020

Net blotch of barley caused by Pyrenophora teres (Died.) Drechsler, is one of the most destructive diseases on barley in Algeria. It occurs in two forms: P. teres f. teres and P. teres f. maculata. A total of 212 isolates, obtained from 58 fields sampled in several barley growing areas, were assessed for fungicide sensitivity by target gene analysis. F129L and G137R mitochondrial cytochrome b substitution associated with quinone outside inhibitors (QoIs) resistance, and succinate dehydrogenase inhibitors (SDHIs) related mutations (B-H277, C-N75S, C-G79R, C-H134R, and C-S135R), were analyzed by pyrosequencing. In vitro sensitivity of 45 isolates, towards six fungicides belonging to three chemical groups (QoI, demethylase inhibitor, and SDHI) was tested by microtiter technique. Additionally, sensitivity towards three fungicides (azoxystrobin, fluxapyroxad, and epoxiconazole) was assessed in planta under glasshouse conditions. All tested isolates were QoI-sensitive and SDHI-sensitive, no mutation that confers resistance was identified. EC₅₀ values showed that pyraclostrobin and azoxystrobin are the most efficient fungicides in vitro, whereas fluxapyroxad displayed the best disease inhibition in planta (81% inhibition at 1/9 of the full dose). The EC₅₀ values recorded for each form of net blotch showed no significant difference in efficiency of QoI treatments and propiconazole on each form. However, in the case of fluxapyroxad, epoxiconazole and tebuconazole treatments, analysis showed significant differences in their efficiency. To our knowledge, this study is the first investigation related to mutations associated to QoI and SDHI fungicide resistance in Algerian P. teres population, as well as it is the first evaluation of the sensitivity of P. teres population towards these six fungicides.

• Parasites, Hosts and Diseases
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• 제28권1호
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• pp.25-30
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• 1990

질트리코모나스(Trichomonas vaginalis)감염 환자 30명과 비감염 건강 대조군 30명을 패 상으로 혈청 내 항-질트리코모나스 IgG 및 IgM 항체가를 효소표식 면역검사법(enzyme-linked immunosorbent assay: ELISA)으로 측정하여 이 질환 진단법으로서 ELISA의 이용 가능성을 검토 하고, 현펑 내 IgG 및 IsM 항체가의 상관성을 알아보았다. 질트리코모나스 환자의 혈청 내 IgG 항체가는 0.37±0.134로 건강 대조군의 0.21±0.054 보다 유 의하게 높았다(p<0.005). 또 혈청 내 IgG 항체가 0.32 이상을 양성으로 하였을 때 ELISA 진단법 의 감수성은 70.0%이었고 특이성은 96.7%이었다. 질트리코모나스 환자의 혈청 내 IsM 항체가는 0.33±0.177로 건강 대조군의 0.11±0.051 보다 유의하게 높았다(p<0.005). 또 혈청 내 Is변 항체 가 0.21 이상을 양성 반응으로 하였을 때 감수성은 70.0%이었고 특이성은 96.7%이었다. 질트리코 모나스 환자의 혈청 내 IgG 와 IsM 항체가의 상관 관계는 상관계수 r=0.77로 유의한 상관관계가 인 정 되 었 다(p<0.005). 이상의 결과로 보아 질트리코모나스 환자에서 혈청 내 19G 및 IsM 항체가를 ELISA법으로 측정 함으로써 질트리코모나스 감염을 진단하거나 역학적 조사에 이용할 수 있을 것으로 생각된다.

• 센서학회지
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• 제6권5호
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• pp.356-361
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• 1997

광섬유 소산파 센서(fiber-optic evanescent wave sensor)를 제작하였다. 클래드층을 제거한 광섬유 코아 표면에 anti-mouse immunoglobulin G(IgG)를 결합시키고, 형광이 표지된 mouse IgG와의 반응을 직접적인 방법과 경쟁적인 방법을 통하여 측정하였다. 직접적인 방법과 경쟁적인 방법 모두 $1{\mu}g/m{\ell}$이하의 mouse IgG를 측정할 수 있는 감도를 얻을 수 있었다. Anti-mouse IgG는 단순 흡착 방법에 의하여 광섬유 코아 표면의 93.9%에 고정되었고 비특이적 결합반응을 제거하기 위하여 실시한 소혈청 알부민(bovine serum albumin : BSA)을 이용한 표면 코팅 효과는 없었다. Mouse IgG에 결합된 fluorescein의 비율이 높을수록 형광 발생량이 많았으나 관계는 직선적이지 않았다. 본 연구에서 제작된 광섬유 소산파 센서는 $1{\mu}g/m{\ell}$ 이하의 항원 항체 반응을 소산파 여기에 의한 형광량으로 측정할 수 있어 면역센서로의 응용이 가능할 것으로 판단된다.

• 한국지진공학회논문집
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• 제18권4호
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• pp.161-170
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• 2014

Newmark-type deformation analysis has rarely been done in Korea due to the popularity of simple pseudo-static limit equilibrium analysis and detailed time-history FE/FD dynamic analysis. However, the Korean seismic dam design code updated in 2011 prescribes Newmark-type deformation analysis as a major dynamic analysis method for the seismic evaluation of fill dams. In addition, a design PGA for dynamic analysis is significantly increased in the code. This paper aims to study the seismic evaluation of four existing large fill dams through advanced FEM/Newmark-type deformation analyses for the artificial earthquake time histories with the design PGA of 0.22g. Dynamic soil properties obtained from in-situ geo-physical surveys are applied as input parameters. For the FEM/Newmark analyses, sensitivity analyses are performed to study the effects of input PGA and $G_{max}$ of shell zone on the Newmark deformation. As a result, in terms of deformation, four fill dams are proved to be reasonably safe under the PGA of 0.22g with yield coefficients of 0.136 to 0.187, which are highly resistant for extreme events. Sensitivity analysis as a function of PGA shows that $PGA_{30cm}$ (a limiting PGA to cause the 30 cm of Newmark permanent displacement on the critical slip surface) is a good indicator for seismic safety check. CFRD shows a higher seismic resistance than ECRD. Another sensitivity analysis shows that $G_{max}$ per depth does not significantly affect the site response characteristics, however lower $G_{max}$ profile causes larger Newmark deformation. Through this study, it is proved that the amplification of ground motion within the sliding mass and the location of critical slip surface are the dominant factors governing permanent displacements.

• 한국광학회지
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• 제24권2호
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• pp.86-91
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• 2013

본 논문에서는 근접장-분자반응 간의 중첩을 이용한 표면 플라스몬 공명 (SPR) 바이오센서의 측정감도 평가방법을 연구하였다. 전달행렬 방법을 사용하여 다양한 형태의 중첩적분으로 정의된 광학자취 값을 계산하였고, 샌드위치 및 역샌드위치 면역글로뷸린 (IgG) 어세이에 대해서 실험적으로 측정된 수치와 비교하였다. 이론 및 실험적인 결과와의 비교를 통하여 접선 방향의 전기장을 사용한 광학자취의 경우 그 연속성으로 말미암아 가장 높은 상관계수를 얻을 수 있었으며 이때 광학자취와 측정감도 사이에 97% 이상의 높은 상관계수가 존재함을 보았다. 이러한 상관관계는 SPR 바이오센서의 측정 감도에 관한 메커니즘을 분명하게 설명하며, 분자 스케일 감도를 가지는 SPR 바이오센서 개발에 기여하게 될 것이다.

• 한국해양환경ㆍ에너지학회지
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• 제5권4호
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• pp.48-56
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• 2002

마산만에 대하여 stella 프로그램을 이용한 Tributyltin모델을 구축하였으며, 민감도 분석 및 물질수지를 산정하여 수질관리의 기초자료로 제공하였다. 민감도 분석결과 수층과 유기 입자내 Tributyltin의 경우는 침강속도와 분배계수에 가장 큰 영향을 받는 것으로 나타났으며, 식물플랑크톤 체내의 Tributyltin의 경우는 식물플랑크톤의 생물농축계수가 가장 큰 영향을 미치는 인자로 나타났다. 따라서 추후의 Tributyltin에 대한 모델 적용 시에는 이들 계수에 대한 정밀한 고찰이 필요할 것으로 사료된다. 대상해역의 Tributyltin 현존량은 수층의 Tributyltin량이 3.29×10⁴g, 플랑크톤 체내의 Tributyltin량이 1.16×10²g, 입자상 유기물내의 Tributyltin량이 3.17×10³g로 나타났다 상간의 전환경로는 입자상 유기물로 분배되는 경로가 1.64×10³g/day로 가장 크게 나타났으며, 다음이 저질로의 침전으로 1.52×10³/g/4ay이었으며 외해로의 유출이 1.32×10³g/4ay로 나타났다.

• Parasites, Hosts and Diseases
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• 제60권4호
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• pp.281-288
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• 2022

Malaria continues to be one of the most crucial infectious burdens in endemic areas worldwide, as well as for travelers visiting malaria transmission regions. It has been reported that 8-aminoquinolines are effective against the Plasmodium species, particularly primaquine, for anti-hypnozoite therapy in P. vivax malaria. However, primaquine causes acute hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Therefore, G6PD deficiency testing should precede hypnozoite elimination with 8-aminoquinoline. Several point-of-care devices have been developed to detect G6PD deficiency. The aim of the present study was to evaluate the performance of a novel, quantitative G6PD diagnostics based on a metagenomic blue fluorescent protein (mBFP). We comparatively evaluated the sensitivity and specificity of the G6PD diagnostic modality with standard methods using 120 human whole blood samples. The G6PD deficiency was spectrophotometrically confirmed. The performance of the G6PD quantitative test kit was compared with that of a licensed control medical device, the G6PD strip. The G6PD quantitative test kit had a sensitivity of 95% (95% confidence interval (CI): 89.3-100%) and a specificity of 100% (95% CI: 94.3-100%). This study shows that the novel diagnostic G6PD quantitative test kit could be a cost-effective and time-efficient, and universally mandated screening tool for G6PD deficiency.