• Title/Summary/Keyword: Spectrometer

Search Result 2,560, Processing Time 0.047 seconds

A Study on the On-site Flame Resistant Inspection Method by X-ray Fluorescence Spectrometer (X-선 형광분석기를 이용한 현장방염검사방법에 관한 연구)

  • Kim, Hwang-Jin;Lee, Sung-Eun
    • Fire Science and Engineering
    • /
    • v.30 no.5
    • /
    • pp.124-129
    • /
    • 2016
  • According to the current law, on-site flame resistant-treated interior decorations should pass the flame resistant performance test through a 45 degree combustion test from the district fire department. Although a 45 degree combustion test is the most accurate method for determining the flame resistant performance, it can be unreliable when tested on unauthorized samples. To avoid unauthorized sampling, this study suggests on-site flame resistant inspection by X-ray fluorescence spectrometer. Ten types of flame resistant paint were spread on plywoods and MDFs and the components were analyzed by X-ray fluorescence spectrometer. As a result, due to a difference amounts of substances in each paint, each flame resistant paints showed its own characteristic spectrum and the contents of each substance could be determined. On-site flame resistant inspections can be used efficiently when institutional procedures are created.

Analysis of Measuring Error for Particle Size Analysis by Laser Diffraction Spectrometer (입자크기분석을 위한 레이저회절 분광계의 측정오차 분석)

  • Ha, Sang-An;Son, Heui-Jeong
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.22 no.4
    • /
    • pp.713-722
    • /
    • 2000
  • This study analysed error of measurement and reproducibility for particle size analysis by the laser diffraction spectrometer. Laser diffraction spectrometers has become a very important method of particle size analysis. This measuring method has the advantage of simple operation, good reproducibility and rapid analysis. A feeding and dispersing system have been developed, which allows mass throughputs between 0.1~23 g/min in flowing air and 1.4~35% in flowing liquid. It has been used as a feeder unit for wet and dry particle size analysis from diffraction patterns. Relevant parameters, such as particle shape, particle size, dispersion, flow rate, concentration were analysed for measuring error. And system parameters of instruments for measurement of dynamic processes, eg, measuring time, focal plane, injection pressure drop and dispersion effect by the ultrasonic and mixing of preliminary treatment, were also discussed.

  • PDF

Real-time Interactive Control of Magnetic Resonance Imaging System Using High-speed Digital Signal Processors (고속 DSP를 이용한 실시간 자기공명영상시스템 제어)

  • 안창범;김휴정;이흥규
    • Journal of the Institute of Electronics Engineers of Korea SC
    • /
    • v.40 no.5
    • /
    • pp.341-349
    • /
    • 2003
  • A real time interactive controller (spectrometer) for magnetic resonance imaging (MRI) system has been developed using high speed digital signal processors (DSP). The controller generates radio frequency (rf) waveforms and audio frequency gradient waveforms and controls multiple receivers for data acquisition. By employing DSPs having high computational power (e.g., TMS320C670l) real time generation of complicated gradient waveforms and interactive control of selection planes are possible, which are important features in real-time imaging of moving organs, e.g., cardiac imaging. The spectrometer was successfully implemented at a 1.5 Tesla whole body MRI system for clinical application. Performance of the spectrometer is verified by various experiments including high- speed imaging such as fast spin echo (FSE) and echo planar imaging (EPI). These high-speed imaging techniques reduce measurement time, however, usually intensify artifact if there is any systematic phase error or jitter in the synchronization between the transmitter, receiver, and gradients.

Simulation for Small Lamellar Grating FTIR Spectrometer for Passive Remote Sensing

  • Chung, You Kyoung;Jo, Choong-Man;Kim, Seong Kyu;Kim, In Cheol;Park, Do-Hyun;Bae, Hyo-Yook;Kang, Young Il
    • Journal of the Optical Society of Korea
    • /
    • v.20 no.6
    • /
    • pp.669-677
    • /
    • 2016
  • A miniaturized FTIR spectrometer based on lamellar grating interferometry is being developed for passive remote-sensing. Consisting of a pair of micro-mirror arrays, the lamellar grating can be fabricated using MEMS technology. This paper describes a method to compute the optical field in the interferometer to optimize the design parameters of the lamellar grating FTIR spectrometer. The lower limit of the micro-mirror width in the grating is related to the formation of a Talbot image in the near field and is estimated to be about $100{\mu}m$ for the spectrometer to be used for the wavelength range of $7-14{\mu}m$. In calculating the far field at the detection window, the conventional Fraunhofer equation is inadequate for detection distance of our application, misleading the upper limit of the micro-mirror width to avoid interference from higher order diffractions. Instead, the far field is described by the unperturbed plane-wave combined with the boundary diffraction wave. As a result, the interference from the higher order diffractions turns out to be negligible as the micro-mirror width increases. Therefore, the upper limit of the micro-mirror width does not need to be set. Under this scheme, the interferometer patterns and their FT spectra are successfully generated.

X-Ray Triple Crystal Diffraction Spectrometer and Its Applications (X-Ray Triple Crystal Diffraction Spectrometer의 제작과 그 응용)

  • Park Young-Han;Yeom Byo-Young;Yoon Hyng-Guen;Min Suk-ki;Park Young Joo
    • Korean Journal of Crystallography
    • /
    • v.8 no.1
    • /
    • pp.20-25
    • /
    • 1997
  • Two experimental methods have been developed for high resolution measurement of x-ray scattering. The methods used were (1) an x-ray double crystal diffraction (DCD) spectrometer set-up and (2) an x-ray triple crystal diffraction (TCD) spectrometer set-up. With the DCD arrangement of Si(511)-sample(hkl), rocking curves have been plotted for Si (333), Si(004) and GaAs(004). Also, with the TCD arrangement of Si(111)-Si(111)-Si(511)-sample(hkl) including monolithic monocro-collimator and $K_{\alpha1}$ selector, rocking curves have been plotted for Si(333), Si(004) and GaAs(004). The results of FWHM by DCD and TCD set-up have been compared each other and discussed. The reflection topographs (004) and (115) in an $In_{0.037}Ga_{0.0963}As/GaAs$ sample have been obtained by DCD set-up.

  • PDF

Clinical Study of Acute and Chronic Pain by the Application of Magnetic Resonance Analyser $I_{TM}$ (자기공명분석기를 이용한 통증관리)

  • Park, Wook;Jin, Hee-Cheol;Cho, Myun-Hyun;Yoon, Suk-Jun;Lee, Jin-Seung;Lee, Jeong-Seok;Choi, Surk-Hwan;Kim, Sung-Yell
    • The Korean Journal of Pain
    • /
    • v.6 no.2
    • /
    • pp.192-198
    • /
    • 1993
  • In 1984, a magnetic resonance spectrometer(magnetic resonance analyser, MRA $I_{TM}$) was developed by Sigrid Lipsett and Ronald J. Weinstock in the USA, Biomedical applications of the spectrometer have been examined by Dr. Hoang Van Duc(pathologist, USC), and Nakamura, et al(Japan). From their theoretical views, the biophysical functions of this machine are to analyse and synthesize a healthy tissue and organ resonance pattern, and to detect and correct an abnormal tissue and organ resonance pattern. All of the above functions are based on Quantum physics. The healthy tissue and organ resonance patterns are predetermined as standard magnetic resonance patterns by digitizing values based on peak resonance emissions(response levels or high pitched echo-sounds amplified via human body). In clinical practice, a counter or neutralizing resonance pattern calculated by the spectrometer can correct a phase-shifted resonance pattern(response levels or low pitched echo-sounds) of a diseased tissue and organ. By administering the counter resonance pattern into the site of pain and trigger point, it is possible to readjust the phase-shifted resonance pattern and then to alleviate pain through regulation of the neurotransmitter function of the nervous system. For assessing clinical effectiveness of pain relief with MRA $I_{TM}$ this study was designed to estimate pain intensity by the patient's subjective verbal rating scale(VRS such as graded to no pain, mild, moderate and severe) before application of it, to evaluate an amount of pain relief as applied the spectrometer by the patients subjective pain relief scale(visual analogue scale, VAS, 0~100%), and then to observe a continuation of pain relief following its application for managing acute and chronic pain in the 102 patients during an 8 months period beginning March, 1993. An application time of the spectrometer ranged from 15 to 30 minutes daily in each patient at or near the site of pain and trigger point when the patient wanted to be treated. The subjects consisted of 54 males and 48 females, with the age distribution between 23~40 years in 29 cases, 41~60 years in 48 cases and 61~76 years in 25 cases respectively(Table 1). The kinds of diagnosis and the main site of pain, the duration of pain before the application, and the frequency of it's application were recorded on the Table 2, 3 and 4. A distinction between acute and chronic pain was defined according to both of the pain intervals lasting within and over 3 months. The results of application of the spectrometer were noted as follows; In 51 cases of acute pain before the application, the pain intensities were rated mild in 10 cases, moderate in 15 cases and severe in 26 cases. The amounts of pain relief were noted as between 30~50% in 9 cases, 51~70% in 13 cases and 71~95% in 29 cases. The continuation of pain relief appeared between 6~24 hours in two cases, 2~5 days in 10 cases, 6~14 days in 4 cases, 15 days in one case, and completely relived of pain in 34 cases(Table 5~7). In 51 cases of chronic pain before the application, the pain intensities were rated mild in 12 cases, moderate in l8 cases and severe in 21 cases. The amounts of pain relief were noted as between 0~50% in 10 cases, 51~70% in 27 cases and 71~90% in 14 cases. The continuation of pain relief appeared to have no effect in two cases. The level of effective duration was between 6~12 hours in two cases, 2~5 days in 11 cases, 6~14 days in 14 cases, 15~60 days in 9 cases and in 13 cases the patient was completely relieved of pain(Table 5~7). There were no complications in the patients except a mild reddening and tingling sensation of skin while applying the spectrometer. Total amounts of pain relief in all of the subjects were accounted as poor and fair in 19(18.6%) cases, good in 40(39.2%) cases and excellent in 43(42.2%) cases. The clinical effectiveness of MRA $I_{TM}$ showed variable distributions from no improvements to complete relief of pain by the patient's assessment. In conclusion, we suggest that MRA $I_{TM}$ may be successful in immediate and continued pain relief but still requires several treatments for continued relief and may be gradually effective in pain relief while being applied repeatedly.

  • PDF

A Multi-Channel Gas Sensor Using Fabry-Perot Interferometer-Based Infrared Spectrometer

  • Choi, Ju Chan;Lee, June Kyoo;Kong, Seong Ho
    • Journal of Sensor Science and Technology
    • /
    • v.21 no.6
    • /
    • pp.402-407
    • /
    • 2012
  • We report a Fabry-Perot interferometer (FPI)-based multi-channel micro-spectrometer used for multi-gas measurement in the spectral range of $3-5{\mu}m$ and its gas sensing performance. The fabricated infrared (IR) spectrometer consists of two parts: an FPI on the top side for selective IR filtering and a $V_2O_5$-based IR detector array on the bottom side for the detection of the filtered IR. Experimental results show that the FPI-based multi-channel gas sensor has reliability and selectivity for simultaneously detecting environmentally harmful gases such as $CH_4$, $CO_2$, $N_2O$ and CO in the spectral range of $3-5{\mu}m$. The fabricated FPI-based multi-channel gas sensor also demonstrated that a reliable and selective detection of gas concentrations ranging from 0 to 500 ppm is feasible. In addition, the electrical characteristics demonstrate a superior response performance in regards to the selectivity in the multi-target gases.

Study on the Measurement of Emission Spectrum and Reaction Mechanism of OH Radical in the Nitrogen Corona Discharge System for Removal of $NO_x$ in Flue Gas (배연가스의 $NO_x$제거용 코로나 방전장치에서 OH 발광 스펙트럼 측정 및 관련 반응 연구)

  • Park, Chul-Woung;Hahn, Jae-Won;Shin, Dong-Nam
    • Journal of the Korean Society of Combustion
    • /
    • v.4 no.1
    • /
    • pp.27-38
    • /
    • 1999
  • We constructed a wire-cylinder type pulsed corona discharge system for $NO_x$ removal, which was operated in room temperature. A emission spectrometer was built with a boxcar averager and monochrometer equipped with photo-multiplier tube detector. The sensitivity of the emission spectrometer was greatly improved by synchronizing the emission spectrometer with pulsed corona discharge system using a triggered spark-gap switch. $N_2$ spectrum($c^3{\Pi}_u{\rightarrow}X^1{\Sigma}_g{^+}$) was measured in the range of 300 - 450 nm and oxidizing OH radical emission($A^2{\Sigma}^+{\rightarrow}X^2{\Pi}$) was measured in case $N_2$ was supplied with water bubbling. As wet gas composition of inlet $N_2$ supplied in the discharge system increased, the intensity of OH emission was increased and saturated at wet gas composition 50%. We also investigated additive effect of $C_2H_4,\;H_2O,\;H_2O_2$ on the intensity of OR emission and $NO/NO_2/NO_x$ reduction and analysed the related reaction mechanism in corona discharge process. $H_2O_2$ additive increased the intensity of OH emission and $NO/NO_x$ reduction.

  • PDF

A Study on the Characteristic of the $^6Li$ Neutron Spectrometer ($^6Li$ 중성자분광계 특성 연구)

  • Choe, Seong-Ho;Kang, Sam-Woo;Lee, Kwang-Pill;Lee, Kyung-Ju;Hwang, Sun-Tae
    • Analytical Science and Technology
    • /
    • v.5 no.1
    • /
    • pp.57-61
    • /
    • 1992
  • For the neutron spectrum measurement, $^6Li$ neutron spectrometer system is installed. The characteristic of the $^6Li$ detector are investigated using a $^{137}Cs$ and $^{207}Bi$ point source, and the neutron capture peaks and the pulse height spectrum using an $^{214}Am-Be$ neutron source are measured. Furthermore, the pulse height spectrum for the irradiation time variation from the (214)^Am-Be neutron source, and for the distance variation between detector and source, and the threshold variation of discriminator are measured.

  • PDF

In Situ Estimation of the Constituents of Green Soybean (Edamame) Pod using Near-Infrared Transmission Spectroscopy

  • Suzuki, Michiru;Katahira, Mitsuhiko;Natsuga, Motoyasu
    • Journal of Biosystems Engineering
    • /
    • v.39 no.4
    • /
    • pp.352-356
    • /
    • 2014
  • Purpose: We estimated the dietary qualities of green soybean (edamame) by using a specialized NIR transmission spectrometer to determine the constitutive properties of the soybean, such as the sucrose content and ninhydrine reaction quantity (NRQ; defined by the ninhydrine reaction, which has a high positive correlation with the total free amino acids), with the purpose of establishing a quality assurance system. Methods: We used a newly developed spectrometer probe that enables in situ estimation of the constituents of the soybean. Results: The calibration results obtained using a wavelength range of 760-960 nm were characterized by $R^2$ = 0.57 and standard error of cross-validation (SECV) of 0.78% for sucrose, and $R^2$ = 0.59 and SECV = 0.35% for NRQ. Conclusions: These results are inferior to those of our previous study obtained using a specialized bench-type transmission spectrometer. The poorer results are attributed to several possible reasons, including the effect of direct sunlight and the unstable sample presentation. We plan to conduct further study using improved optical layout and sample presentation.