Determination of impurities in graphite using synchrotron radiation based X-ray fluorescence spectrometry.
Determination of impurities namely Ca, Mn, Fe, Ni, Zn, Sr and Pb in graphite by energy dispersive X-ray fluorescence spectrometry is described using microfocused synchrotron radiation. The internal standard and standard addition methodologies were adopted for quantification and the results were compared with tube-based X-ray fluorescence spectrometry. Analysis of the results by the F and t-tests revealed their statistical equivalence. Synchrotron measurements improved the detection limits by an order of magnitude compared to the tube based technique. Cr and Zr, which were below the quantification limit in tube based technique, were also quantified by synchrotron based technique.
Use of X-Ray Fluorescence Spectrometry to Determine Trace Elements in Graphite
This paper deals with application of X-ray fluorescence spectrometry for the detection of trace elements in graphic. An X-ray spectrometer was constructed and used to carry out measurements on graphite spheres impregnated with different chemical elements. The intensities of the lines of these trace elements, as function of concentration, were measured in order to establish the sensitivity of the spectrometer. These measurements have shown that X-ray fluorescence methods can easily be employed for detection of trace elements in graphite samples with conventional X-ray tubes, the sensitivity of the spectrometer was about 29 ppm for Zr.
A Study on Greenhouse Automatic Control System Based on Wireless Sensor Network
The system proposed in this paper collects temperature of leaves and humidity on leaves of crop. As well as greenhouse environmental information such as temperature, humidity, etc. Crop diseases, especially, have deep relationship not only with indoor environmental factors but also with humidity lasting time on leaves and temperature of leaves. Accordingly, monitoring crop itself is as important as monitoring indoor environments. Using these collected greenhouse environmental data, indoor environments can be more effectively controlled, and monitoring crop itself can contribute to improve productivity and to prevent crops from damages by blight and harmful insects. In addition, it will be possible for farmers to do control plant growth through closely studying relationship between indoor environmental information and monitored information on crop itself. Collected data can be stored to database either in server installed in greenhouse or to remote server. It is made possible to collect information and control effectively and automatically greenhouse in the site or from a remote place through web browser. System components are: temperature sensor, humidity sensor, leaf temperature sensor, leaf humidity sensor, Zigbee based wireless sensor node, relay nodes for automatic control, and data server to store greenhouse information. The system is implemented using low power wireless components, and easy to install.