• Title/Summary/Keyword: sensitive detection

Search Result 1,731, Processing Time 0.028 seconds

"Turn-on" type colorimetric/fluorimetric probe for selective detection of Cu2+ at neutral pH condition

  • Lee, Hyun Jung;Saleem, Muhammad;Lee, Ki Hwan
    • Rapid Communication in Photoscience
    • /
    • v.4 no.4
    • /
    • pp.88-90
    • /
    • 2015
  • The design and development of fluorescent chemosensors have recently been intensively explored for sensitive and specific detection of environmentally and biologically relevant metal ions in aqueous solution and living cells. Herein, we report the photophysical results of rhodamine B based fluorogenic and chromogenic receptor for selective copper detection in the complete organic or mixed aqueous-organic media at neutral pH under ambient condition. The ligand exhibited the remarkable increment in the fluorescence emission and UV-visible absorption signal intensities at 587 and 547 nm, respectively, on induction of copper ion while the ligand solution remain completely silent on addition of varieties of other metal ions.

$NO_2$ Gas Detection Characteristics of Langmuir-Blodgett Films layered with Dilithium phthalocyanine($Li_2Pc$) (유기 초박막의 가스 특성에 관한 연구)

  • Cho, H.K.;Yoo, B.H.;Kim, H.S.;Kim, T.W.;Kim, J.S.
    • Proceedings of the KIEE Conference
    • /
    • 1994.07b
    • /
    • pp.1298-1300
    • /
    • 1994
  • An ability of $NO_2$ gas detection has been investigated using dilithium phthalocyanine($Li_2Pc$) Langmuir-Blodgett (LB) films. It is a well-known gas sensitive material and has been manufactured under a surface pressure of 30mN/m. A status of deposited films was confirmed by UV-visible absorption spectrum, ellipsometry measurements and current-voltage characteristics. Gas-detection characteristics of the films were studied through an electrical conductivity, response time, recovery time, and reproducibility under 200 ppm of $NO_2$ gases.

  • PDF

Detection of Bombyx mori Nuclear Polyhedrosis Virus(BmNPV) in dust of Silkworm rearing room by PCR (PCR법에 의한 잠실먼지 중 핵다각체병 바이러스의 검출)

  • 남성희;한명세
    • Journal of Sericultural and Entomological Science
    • /
    • v.39 no.1
    • /
    • pp.30-35
    • /
    • 1997
  • A rapid and sensitive detection of BmNPV contamination in silkworm rearing room was carried by Plymerase chain reaction(PCR). Silkworm nuclear polyhedra were dissolved for the extraction of viral DNA within 30 minutes followed by the treatment of alkaline solution. The combination of primers of NP3 and NP2 was superior in PCR to the other 7 primers applied. Each primer was designed with 20 base in size and Newly designed NP3 of sense and the already reported NP2 for antisense were better in reaction than other primers. PCR products appeared 500bp in size. And annealing was confirmed proper at 55$^{\circ}C$ condition. Amplifiable template DNA amount was confirmed at least 100 ng to 0.1 ng and regarded as applicative for the assay of silkworm rearing environmental condition of sericultural farm. In case of the detection of BmNPV from the dust, sensitivity by PCR was as high as 1,000,000 times than that of microscopic observation.

  • PDF

An Automatic Contour Detection of 2-D Echocardiograms Using the Heat Anisotropic Diffusion Method (Heat Anisotropic Diffusion 방법을 이용한 2차원 심초음파도의 경계선 자동검출)

  • Shin, Dong-Jo;Jung, Jung-Wan;Kim, Hyouk;Kim, Dong-Youn
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1994 no.12
    • /
    • pp.9-13
    • /
    • 1994
  • The Heat Anisotropic Diffusion Method has shown very effective for the contour detection of 2-D echocardiogram. To implement this algorithm, we have to choose the parameter C, K, and the threshold level. The choice of C and K are not very sensitive for the good edge detection of the echocardiogram, however the choice of the threshold level is very critical. Until now the threshold level is chosen by the trial and error method. In this paper, we present an automatic threshold decision method from the histogram of the gradient of boundary-like pixels.

  • PDF

Detection of Nitroaromatic Compounds Based on Silicon Nanoparticles (실리콘 나노 입자를 이용한 니트로방향족 화합물의 탐지)

  • Song, Jinwoo
    • Journal of Integrative Natural Science
    • /
    • v.2 no.1
    • /
    • pp.37-40
    • /
    • 2009
  • Synthesis and characterization of alkyl-capped nanocrystalline silicon (R-n-Si) have been achieved from the reaction of silicontetrachloride with magnesiumsilicide. Surface of silicon nanocrystal has been derivatized with various alkyl groups (R=methyl, n-butyl, etc.). Silicon nanoparticles have been also obtained by the sonication of luminescent porous silicon. Former exhibits an emission band at 360 nm, but latter exhibits an emission band at 680 nm. In this study very sensitive detection of TNT (2,4,6-trinitrotoluene), DNT (2,4-dinitrotoluene), NB (nitrobenzene), and PA (picric acid) has been achieved in gas phase with porous silicon using photoluminescence quenching of the silicon crystallites as a transduction mode. Porous silicon are electrochemically etched from crystalline silicon wafers in an aqueous solution of hydrofluoric acid. We have characterized these silicon nanoparticles by Luminescence Spectrometer (LS 55).

  • PDF

Studies on enzyme-linked immunosorbent assay(ELISA) for detection of antibody to Brucella abortus (효소면역법을 이용한 Brucella abortus 항체 검출에 관한 연구)

  • 심항섭;국정희;정봉수;고태오;조중현;박유순
    • Korean Journal of Veterinary Service
    • /
    • v.21 no.2
    • /
    • pp.107-115
    • /
    • 1998
  • In order to establish a rapid, sensitive and specific diagnostic method for detection of antibody to Brucella abortus, a enzyme-linked immunosorbent assay(ELISA) was adapted. The diagnostic efficacy of the established ELISA was compared with that of the standard tube agglutination test for B abortus. 1. It was found that the optimal concentration of antigen for this ELISA was 5$\mu\textrm{g}$/ml, the optimal dilution of conjugate was 1 : 2000, and the optimal dilution of serum was 1 : 200, respectively. 2. Cut off value in this ELISA was 1,102 that was determined by mean absorbance(at 492nm) of tube agglutination test negative serum added with the triple value of the standared devation. 3. The relationship between the tube agglutination test and ELISA was showen high corresponding rate with sensitivity(96.3%) and specificity(98.1%). 4. The efficacy of the ELISA for detection of B abortus antibody was compared with tube agglutination test In brucellosis outbreak farm. The sensivity of ELSIA was higher than tube agglutination test.

  • PDF

내장형 절삭력센서와 AE 센서를 이용한 인-프로세스 공구파괴 검출에 관한 연구

  • 최덕기;박동삼;주종남;이장무
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1992.10a
    • /
    • pp.344-348
    • /
    • 1992
  • This paper presents a new methodology for on-line tool breakage detection by sensor fusion concept of an acoustic-emission (AE) sensor. A built-in piezoelectric force sensor was used to measure cutting force instead of a tool dynamometer to preserve the machine tool dynamics. he sensor was inserted in the tool turret housing of an NC lathe. FEM analysis was carried out to locate the most sensitive position for the sensor. When a tool is broken, the explicit changes of signals' pattern take place. A burst-type AE signal increases abruptly. Followingly, a cutting force drops significantly. Therefore a burst of AE signal is used as a triggering signal to inspect the following cutting force. Significant drop of cutting force is utilized to detect tool breakage. The algorithm was implemented in a DSP board for in-process tool breakage detection. The proposed monitoring system was capable of a good applicable tool breakage detection.

Control Method for the number of check-point nodes in detection scheme for selective forwarding attacks (선택적 전달 공격 탐지 기법에서의 감시 노드 수 제어기법)

  • Lee, Sang-Jin;Cho, Tae-Ho
    • 한국정보통신설비학회:학술대회논문집
    • /
    • 2009.08a
    • /
    • pp.387-390
    • /
    • 2009
  • Wireless Sensor Network (WSN) can easily compromised from attackers because it has the limited resource and deployed in exposed environments. When the sensitive packets are occurred such as enemy's movement or fire alarm, attackers can selectively drop them using a compromised node. It brings the isolation between the basestation and the sensor fields. To detect selective forwarding attack, Xiao, Yu and Gao proposed checkpoint-based multi-hop acknowledgement scheme (CHEMAS). The check-point nodes are used to detect the area which generating selective forwarding attacks. However, CHEMAS has static probability of selecting check-point nodes. It cannot achieve the flexibility to coordinate between the detection ability and the energy consumption. In this paper, we propose the control method for the number fo check-point nodes. Through the control method, we can achieve the flexibility which can provide the sufficient detection ability while conserving the energy consumption.

  • PDF

Evaluation of Two Types of Biosensors for Immunoassay of Botulinum Toxin

  • Choi, Ki-Bong;Seo, Won-Jun;Cha, Seung-Hee;Choi, Jung-Do
    • BMB Reports
    • /
    • v.31 no.1
    • /
    • pp.101-105
    • /
    • 1998
  • Immunoassay of botulinum toxin (BTX) B type was investigated using two typed of biosensors: light addressable potentiometric sensor (LAPS) and surface plasmon resonance (SPR) sensor. Urease-tagged and immuno-filtration capture method have been used for LAPS. Tag-free and direct binding real-time detection method have been used for SPR sensor. The detection limit of sandwich assay format with LAPS was 10 ng/ml, which was the lowest among methods tested. SPR has the advantage of being more convenient because tag-free direct binding assay can be used and reaction time was reduced, regardless of low sensitivity. This result shows that sandwich assay format with LAPS can be used as an alternative method of BTX mouse bioassay which is known as the most sensitive method for the detection of BTX.

  • PDF

Obstacle Detection using Laser Scanner and Vision System for Path Planning on Autonomous Mobile Agents (무인 이동 개체의 경로 생성을 위한 레이저 스캐너와 비전 시스템의 데이터 융합을 통한 장애물 감지)

  • Jeong, Jin-Gu;Hong, Suk-Kyo;Chwa, Dong-Kyoung
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.57 no.7
    • /
    • pp.1260-1272
    • /
    • 2008
  • This paper proposes object detection algorithm using laser scanner and vision system for the path planning of autonomous mobile agents. As the scanner-based method can observe the obstacles in only two dimensions, it is hard to detect the shape and the number of obstacles. On the other hand, vision-based method is sensitive to the environment and has its difficulty in the accurate distance measurement. Thus, we combine these two methods based on K-means algorithm such that the obstacle avoidance and optimal path planning of autonomous mobile agents can be achieved.