-------------------------Monitor------------------------ The Newsletter for PC-Based Data Acquisition and Control Issue 111 www.windmill.co.uk October 2007 --------------------ISSN 1472-0221---------------------- Welcome to October's issue of Monitor. I hope you enjoy the newsletter but should you wish to cancel your subscription you can do so at https://www.windmill.co.uk/newsletter.html CONTENTS ======== * Windmill News: Windmill helps radioactive research * Excel Corner: Reading X and Y values off Excel Charts * DAQ News Roundup ________________________________________________________ ________________________________________________________ Windmill News: Windmill helps radioactive research ________________________________________________________ Scientists are investigating the flow of radioactive material through the Yucca Mountain in Nevada. To date measurements and models have assumed a classical, steady-state diffusion. The researchers wanted to test if this was an accurate assumption. As part of their experiments they took borehole samples, exposed one face of the rock sample to water or tracer solution and monitored the liquid uptake over time. Core samples of varying height to diameter ratios were used to investigate the shape effect. They hung the rock sample from a bottom-weighing analytical balance to measure the weight change during liquid imbibition. To regularly save the readings to computer disk, they downloaded the free Windmill from the Windmill web site. Windmill logged balance readings and to the computer at selected time intervals, starting with every second and increasing the interval as time went on. The Windmill software helped show that the steady-state diffusion assumed by previous models cannot be applied to the Yucca mountain. Yucca mountain is the site of a proposed storage facility for radioactive waste. Further reading: Q Hu, R P Ewing, L Tomutsa and M J Singleton. Pore Connectivity, Episodic Flow, and Unsaturated Diffusion in Fractured Tuff http://www.uta.edu/ More Windmill application stories are at https://www.windmill.co.uk/software.html#applications ________________________________________________________ ________________________________________________________ Excel Corner: Reading X and Y values off Excel Charts ________________________________________________________ This month we were asked how to obtain the Y value on an Excel XY scatter chart, given that the corresponding X value was known. There are three approaches to this. The easiest is to use an Excel add-in that has been created especially to do this. The second way is to generate an equation which accurately describes your data, and use that to calculate your values. Thirdly you may be able to use Excel's built in functions to calculate the values. 1. Using an Excel Add-In An Excel add-in contains code that adds extra features to Excel. Excel is shipped with a variety of add-ins, and there are many third-party add-ins available. One which solves our problem is provided by Tushar Mehta at http://www.tushar-mehta.com/ This creates a dialogue box which when you enter an X value tells you the corresponding Y value, and vice versa. It also draws dotted horizontal and vertical lines to the Y and X axes from the specified point. Another add-in is provided by Advanced Systems Design and Development at http://www.xlxtrfun.com/XlXtrFun/XlXtrFun.htm This provides functions to interpolate, extrapolate and curve fit data rapidly. Use the Interpolate function to find the Y value at a given X value. 2. Generating an Equation from your XY Scatter Chart On your XY Scatter chart insert a trendline that fits your data. Right-click the data series and select Add Trendline. Click the options tab and choose to display both the equation and the R-squared value on the chart. The R-squared value shows how closely your data fits the equation. A value of 1 indicates an exact fit. Values far away from 1 indicate that your calculations won't be accurate and you should try another trendline. Copy the right-hand part of the equation into a cell, replacing the x with a reference to the cell holding your known X value. For example, for a linear trendline the equation Excel displays might be y = 1.97x + 0.1. If your known X value was in cell H8, you would enter: =1.97*(H8)+0.1. 3. Using Excel's Functions Excel has a couple of built in functions which you can use to return Y values. - For a linear trendline use TREND() - For an exponential trendline use GROWTH() Which is the best method to use? I've found that using one of the add-ins gives the best results. For more on data acquisition and control using Excel see https://www.windmill.co.uk/excel/ https://www.windmill.co.uk/excel/excel-charting.html ________________________________________________________ ________________________________________________________ DAQ News Roundup ________________________________________________________ Welcome to our roundup of the data acquisition and control news. If you would like to receive more timely DAQ news updates then grab our RSS newsfeed at https://www.windmillsoft.com/monitor.xml. Read https://www.windmill.co.uk/newsfeed.php for notes on how to display the news on your own web site, read it via e-mail, mobile phone or a newsfeed viewer. Smart sheets let gadgets talk through their feet Flexible, electronic sheets could be embedded in tables, walls and floors, allowing devices anywhere in the home to communicate. Plastic transistors and copper wires that snake through the sheets allow gadgets placed on them to form spontaneous connections and swap data. Source: New Scientist https://www.newscientist.com/ New Quantum Dot Transistor Counts Individual Photons A transistor containing quantum dots that can count individual photons (the smallest particles of light) has been designed and demonstrated at the National Institute of Standards and Technology. The semiconductor device could be integrated easily into electronics and may be able to operate at higher temperatures than other single-photon detectors. Source: National Institute of Standards and Technology https://www.nist.gov/ Microwaves offer fat chance to probe supermarket food Microwaves used for zapping instant meals can also be used to determine the fat and salt content of supermarket food, according to research carried out at two Manchester universities. Constant real-time monitoring by the microwave sensors during the production process could help reduce waste, maximise yield, reduce laboratory testing and save energy. Source: Manchester University http://www.manchester.ac.uk/ Proximity Sensor Market in North America Being Won by European Vendors The North American market for proximity sensors has increased at a moderate single-digit average annual growth rate over the last 15 years. However, during the same period, two European vendors have each achieved approximately double the annual market growth rate, and are now the leading suppliers in the market. Source: VDC http://www.vdcresearch.com/? ________________________________________________________ ________________________________________________________ * Copyright Windmill Software Ltd * Reprinting permitted with this notice included * For more articles see https://www.windmill.co.uk We are happy for you to copy and distribute this newsletter, and use extracts from it on your own web site or publication, providing the above notice is included and a link back to our website is in place. An archive of previous issues is at https://www.windmill.co.uk/newsletter.html and an index of articles at https://www.windmill.co.uk/newsletter.html Windmill Software Ltd, PO Box 58, North District Office, Manchester, M8 8QR, UK Telephone: +44 (0)161 834 6688 Facsimile: +44 (0)161 833 2190 E-mail: monitor@windmillsoft.com https://www.windmill.co.uk/ https://www.windmillsoft.com/ Do you have a question, comment or suggestion on this newsletter? Fill in this form to contact the editor.
October 2007
