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Tong Y.-D.,Peking University | Tong Y.-D.,Tianjin University | Ou L.-B.,Peking University | Chen L.,Peking University | And 5 more authors.
Environmental Toxicology and Chemistry | Year: 2015

The circulation of rice from contaminated areas could escalate exposure risk from a local problem to a national issue and affect a wider population beyond the region of origin, as confirmed by the "Poison Rice Incident" in May 2013 in Guangzhou, China. In the present study, the authors established a food chain model based on the aquivalence method to identify major sources of methylmercury (MeHg), estimate the levels of MeHg, and quantify exposure to MeHg via rice and aquatic food consumption. Different types of organism samples from the Haihe River also were collected to verify the calculated values. The MeHg intake in pregnant women was 1529.1ng/d from the aquatic food chain and as high as 2804.0ng/d from rice, although the intake varied among scenarios. The maximum possible MeHg concentration in the blood of pregnant women was 5.21μg/L, higher than the threshold value of MeHg recommended by the US Environmental Protection Agency (4.4μg/L), which indicated that pregnant women could face risk from MeHg exposure. The authors also assessed the risk of MeHg exposure in pregnant women and their breastfed infants using a new index, HQEquivalent. In 4 scenarios, the HQEquivalent indices ranged from 0.42 to 1.18 for pregnant women and from 0.29 to 0.83 for breastfed infants. © 2014 SETAC. Source

Liu J.,Tianjin University | Cai Z.-J.,Tianjin University | Zhang Z.-Y.,Tianjin University | Sun D.,Tianjin University | And 2 more authors.
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2016

To evaluate the precision level of Photolepthysmography(PPG) in detection of the main components of human blood, the formula for the limit resolution concentration of material components measurement was given based on the Lambert-Beer's Law and simplified measurement model of PPG. Through the evaluation of three elements-Signal-to-Noise Ratio(SNR) of light intensity, optical path and the molar extinction coefficient of the blood components during human measurements, the theoretical limit resolution concentrations of the pulse oximeter signal method for hemoglobin, albumin and blood glucose were obtained. The evaluation result shows that the limit resolution concentration levels of hemoglobin, albumin and blood glucose which can be measured through PPG are respectively 100 mg/dL, 5000 mg/dL and 10 000 mg/dL. The comparison of the evaluation result with the detection precision needed on clinic at the present stage indicates that the PPG can meet the demands for the non-invasive detection of hemoglobin. © 2016, Science Press. All right reserved. Source

Zhang B.,Tianjin University of Technology | Li Z.,Tianjin University of Technology | Ji G.,Tianjin Institute of Metrological Supervision and Testing
ICCASM 2010 - 2010 International Conference on Computer Application and System Modeling, Proceedings | Year: 2010

With the development of wind power technology, the wind farm becomes a large station in which many kinds of devices are. These devices are from different companies having their own monitoring systems, so it is hard to monitor and manage the whole wind farm on one device. This paper design a large-scale wind farm monitoring system based on Browser/Server in which power quality monitoring system, power plant high voltage station and central remote control system, wind tower database are included. By applying this system, operator can monitor the hole wind farm on one device and avoid potentially malfunction in system. © 2010 IEEE. Source

Yang Z.,Tianjin Institute of Metrological Supervision and Testing
Key Engineering Materials | Year: 2016

As an important measurement instruments of trade metering, gas flowmeter has been more and more widely used, and the quantity value transfer of the flow meter is becoming increasingly significant. In order to realize the accurate measurement, the method of the coaxial connection between gas flowmeter and critical flow Venturi nozzle gas flow standard device is studied in this paper, and the coaxial error between this gas flowmeter and standard device within ±1mm is achieved. © 2016 Trans Tech Publications, Switzerland. Source

Gou J.,Tianjin University | Wang Z.,Tianjin University | Lu R.,Tianjin Institute of Metrological Supervision and Testing | Shen X.,Tianjin University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

Pixel equivalent is an important parameter to describe the relationship between pixels of digital images and actual size of measured piece in a 2D image measuring system. It is mainly calibrated with the standard component method, which is traditionally off-line and requires measuring conditions and attitude of devices to remain constant while measuring and calibrating. To overcome above limitations, a new calibration method is proposed in this paper which is defined as the float equivalent method. This method requires the standard component and measured piece be placed in image measuring system simultaneously. Everytime before measuring, no matter aiming at the same measuring point or not, the pixel equivalent is calibrated for this specific time, specific condition, specific measuring point, and specific object distance. This method has the advantage of reducing the influence of conditions changing on the accuracy without additional calibration equipment or operations. The steel tape verification system is taken as an example to testify the effectiveness of the method. © 2015 SPIE. Source

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