April 2000

Dear subscriber;

Welcome to the April PowerUltrasonics newsletter. I'm aiming to put out newsletters every six weeks or so when there have been developments on the site to report. Please feel free to forward a copy to anyone else you think would be interested.

~~~~~~~~~~~~~~~~~~ NEW ARTICLES ~~~~~~~~~~~~~~~~~~~

New on the articles page since last issue:

Numerical calculation of pressure fields in sonochemical reactors, by Sascha Dähnke and Frerich J. Keil.

A mathematical analysis aimed at calculating theoretically the oscillating pressure fields in various sonochemical reactors. The results (so far based on linear analysis only) include pressure maps for several different designs, one of which is available as an animation. Did you think the amplitude in your sonochemistry reaction vessel was uniform?!

Theory of ultrasonic metal welding from American Technology (AmTech) Inc.

With AmTech and Stapla both providing high-quality information, ultrasonic metal welding is particularly well served on the web. AmTech's articles are aimed particularly at wire-joining applications, including welding aluminium to copper.

Creating Sonoluminescence, by Hiroshi

A clear account of the equipment required to generate and study sonoluminescence - a surprisingly simple set up suitable for a high-school laboratory. If anyone has tried it please let me know.

Ultrasonic homogenisers from Reson Ultrasonics

Remarkably, mixing water with the fuel can be good for large diesel engines and boiler installations. Of course the water must be very thoroughly mixed... This article from Reson describes their ultrasonic homogeniser which breaks down the droplets of water to 3 microns diameter - hard to achieve by any other method!

~~~~~~~~~~~~~~~~~~ WHAT ELSE IS NEW? ~~~~~~~~~~~~~~~~~~~

The suppliers database (www.powerultrasonics.com/suppliers.html) is now up to 112 suppliers. There are 2 new product categories:

• Ultrasonic homogenizers (ok, I admit it - I didn't have Reson in the database until now!)
• Books and Publications

If you would like to add any of these to the database entry for your organisation, or modify it in any other way, go to the database page (link above), find your details and click on "Modify".

To make it easier to select multiple products / services, I have now (finally!) added a sub-form with check-boxes for each category. Just click on "Help selecting multiple products/services" on the Contact page to get the new form. Using it should be self-explanatory but if you have any problems please let me know.

~~~~~~~~~~~~~~~~ BANNER ADVERTISING ~~~~~~~~~~~~~~~~~

You can hardly fail to notice one change on the site - by way of an experiment I've started putting in banner ads. The aim is to promote the site through banner exchanges (other sites show my banner ad in exchange for my site showing theirs) and ultimately to try to earn a little money to cover site maintenance (I live in hope!). Inconvenience to users should be fairly minor - the ads are no more than 10k in file size, and only one ad is loaded per page view (I really hate web-sites that automatically reload the adverts so often that it interferes with normal browsing).

~~~~~~~~~~~~~~~~~~ BOOKS PAGE ~~~~~~~~~~~~~~~~~~~

The other significant improvement to the site is the books page. I searched all the major on-line bookshops for relevant titles and Barnes and Noble had by far the best selection, so I joined them as an affiliate. On my pages you will find lists of ultrasonics books in several categories, showing covers (where available), titles and authors, linked to the Barnes and Noble site where you can get more information on each one. Start at the main index or go straight to a category:

• sonochemistry
• ultrasound physics
• transducers and materials
• industrial applications

~~~~~~~~~~~~~~~~~~ VISITOR STATS ~~~~~~~~~~~~~~~~~~~

PowerUltrasonics visitor stats for February and March continue to improve, although things do seem to be levelling off a bit - I must get some promotion done! Getting lost from several search engines at the beginning of March didn't help, but at least using WebPosition (see internet page) I was able to see what had happened and correct it quickly.

Here's where February's visitors came from:

Austria, Australia, Bulgaria, Canada, Czech Republic, Finland, France, Germany, Hungary, India, Indonesia, Israel, Italy, Japan, Malaysia, Mexico, Netherlands, Niue, Peru, Portugal, Singapore, South Africa, South Korea, Switzerland, Tanzania, Thailand, Turkey, Ukraine, United Kingdom, United States, US Educational, US Government, Yugoslavia.

And March's:

Australia, Belgium, Brazil, Canada, China, Czech Republic, Denmark, Finland, France, Germany, Iceland, India, Israel, Italy, Mexico, Netherlands, Norway, Poland, Portugal, Romania, Singapore, Spain, Sweden, Thailand, Turkey, United Kingdom, United States, US Educational, US Military.

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That's all for this time. Feedback is always welcome...

Chris Cheers (chris@powerultrasonics.com)