We propose a novel method to extend the measurement range of FMCW reflectometry. In this method, an optical loop with a frequency shifter (working frequency f/sub FS/Hz) is incorporated in the ...reference arm of the reflectometry. As a result, the interference signal corresponding to the reference beam that circulates N found in the loop appears around (N/spl times/f/sub FS/) Hz, which means that the signals from different measurement ranges can be detected in different frequency domains. Therefore, it is possible to extend the measurement range. In the experiment, the measurement range is extended from 15 m to 48 m.
The purpose of this research is to propose and develop a method to measure hemolysis and thrombogenesis non invasively and continuously to aid in development of an artificial heart. Generally, the ...optical absorption rate of hemoglobin is influenced by oxygen saturation except at the isosbestic point, which is not influenced by oxygen saturation. The authors, therefore, used an 805 nm laser diode, an optical spectrum analyzer to obtain greater accuracy. An experimental blood circuit system was constructed using a Bio-Pump, Tygon tubing, a soft shell reservoir, and an optical measurement system. Experimental settings for monitoring hemolysis were as follows; blood volume 200 ml, blood flow 6 L/min, and afterload 200 mmHg. Blood was sampled six times (0, 30, 60, 120, 180, and 240 min), and hemolysis in each sampled was measured using a colorimetric method. Comparing continuous laser measurement data with the sample data, an adequate correlation is obtained, proving that the dynamic trend of hemolysis could be continuously measured. Furthermore, to analyze the process of thrombogenesis, simple experiments were performed using blood neutralized by protamine. As a result, the authors could see the process of thrombogenesis as it occurred and could confirm that this method is able to dynamically detect hemolysis and thrombogenesis.
The TAUVEX space astronomy experiment will image wide sky areas in the 190–280 nm spectral region. The experiment is part of the SODART telescope complex on the Spectrum X-Gamma (SRG) spacecraft, and ...functions as a separate scientific instrument and service system for the spacecraft. TAUVEX consists of three bore-sighted telescopes with 20 cm diameter Ritchey-Chretien optics. Each telescope has a four-position filter wheel and can select one of six UV bands in the spectral region of operation. The photon-counting, imaging detectors cover a field of view of 0.9 degrees, with 80% of the energy from a point source within 10 arcsec, sampled at 3 arcsec intervals. The sensitivity allows the detection of 10–11 mag stars in 2 sec, and 20 mag stars in a typical SRG pointing of 5 hr.
TAUVEX provides off-line aspect solutions for the SODART focal plane instruments and on-line fine pointing information to the SRG attitude and control system. The experiment is being constructed by El-Op Electro-Optical Industries Ltd, and is financially supported by the Government of Israel, through the Israel Space Agency, and the Ministry of Science and Arts. By mid-1994, four models of TAUVEX had been produced and supplied to the SRG integrators: size and mass models in 1992, a thermal model in early 1993, and an engineering model in spring 1994. A qualification model is being tested at El-Op and the flight model will be ready, after testing, burn-in and calibration, in the first quarter of 1997.
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