Here are a few of the articles I have written that have appeared in places like the Vegan Organic Network magazine.
Using water to maintain even temperatures in greenhouses. Appears in Growing Green International Issue 33
Sizing of hosepipes especially useful if you are avoiding mains water. Appears in Growing Green International 34
Vegtank. Using permaculture design techniques to obtain multiple functions from one element. Water storage, micro-climates and protection from one element.