Pipeline - April 2006

In This Edition:

Water Conservation Pitfalls? - A Blast from the Past - IT Update – PC Maintenance

Reader’s Feedback

Welcome to the 3rd edition of AEC’s newsletter, Pipeline.

We hope you are enjoying reading our publication so far. Our intention is that the newsletter be informative and interesting to our colleagues and clients.

Why not drop us a line with your feedback? We’d be interested to hear how you find the content and format of this publication. We’d also welcome any suggestions as to what you’d like to see us include in future editions!

Water Conservation Pitfalls?

Conservation of water resources has been a topical issue in recent years. Good contemporary buildings and industrial facilities are largely gauged on incorporated water conservation measures, and almost everyone seems to have opinions on the issue.

Achievement of conservation targets and plans comes down, ultimately, to engineers, and a number of innovative designs have appeared in response to the demand to minimise water usage and waste. This is all very well in terms of individual projects, but what may be the wider effect of this trend on our infrastructure? This question is prompted by a number of recent comments by AEC’s hydraulics designers.

Many years ago, you sent 9 litres of precious water down the sewer network every time you flushed the toilet. Then someone pointed out the folly of mixing around 0.1 litres of liquid waste with so much water. The dual flush cistern was introduced and eventually became mandatory. It allowed the choice of a 9 litre or 4.5 litre flush. Around ten years ago the flush rate was reduced to 6 litres or 3 litres and now, after recent drought years, there is discussion of a further reduction. This is great from the conservation viewpoint but how does it impact on urban sewer networks?

The engineering of sewerage disposal systems is an ancient art. Fundamentally it relies on maintaining certain flow, depth and velocity in part-full pipes and channels to carry solids away and keep the channel clear. These transport flows are achieved by designing the size and gradient (constant fall) to achieve the necessary conditions based on established average flow rates from source users.

Most of our urban sewerage reticulation was built many years ago in the days of the 9 litre flush. We are now down to one-third of that and many other sources of sewerage flow have been engineered to conserve our precious water and reduce waste. It is this very waste on which the sewer drains rely for effective long-term operation. The concern of hydraulics engineers is that eventually these reduced flows may face us with major infrastructure problems.

We don’t offer any solution to this, we just point out that reduction of water ‘waste’ to sewer is not an end solution in itself. Perhaps before legislating for untrammelled re-cycling of so-called ‘grey water’, authorities need to take advice from their engineers on the minimum flows required to keep their sewerage networks operating safely.

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A Blast from the Past

A Treatise on Electricity and Magnetism is an 1873 textbook on electromagnetism written by James Clerk Maxwell. This work is the cornerstone of our contemporary understanding of electricity.

Maxwell (1831-1879) was a Scottish mathematical physicist educated at the University of Edinburgh and Cambridge University. He developed a set of equations expressing the basic laws of electricity and magnetism, as well as the Maxwell distribution in the kinetic theory of gases. Possessing perhaps the finest mathematical mind of any theoretical physicist of his time, Maxwell is widely regarded as the nineteenth century scientist who had the greatest influence on twentieth century physics.

Maxwell’s work largely featured algebraic mathematics with elements of geometry. He demonstrated that electric and magnetic forces are two complementary aspects of electromagnetism, showing that electric and magnetic fields travel through space in the form of waves at a constant velocity of 3.0 × 108 m/s. He also proposed that light was a form of electromagnetic radiation.

The complete copy of the 1904 edition, both volumes I and II, of Maxwell’s A Treatise on Electricity and Magnetism can be viewed at: http://rack1.ul.cs.cmu.edu/is/maxwell1/ and http://rack1.ul.cs.cmu.edu/is/maxwell2/.

In 1931, on the centennial anniversary of Maxwell’s birthday, Einstein described Maxwell’s work as the "most profound and the most fruitful that physics has experienced since the time of Newton".

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IT Update – PC Maintenance

It may sound simplistic, but by carrying out regular file management and maintenance tasks on your office computers you can free up space on your hard-drives and be operating more efficiently, saving valuable time and money.

Here are some simple ways to keep your PCs running effectively:

• Regularly check your file management system to ensure you aren’t storing unnecessary or obsolete files and folders on your hard-drive.
• Archive files that are not in regular use, and store on CD.
• Keep image libraries and other large file types stored on CD.
  NB. Be sure to keep all CDs labelled and filed in an orderly and accessible manner.
• Ensure that files and folders are not duplicated in various areas of your electronic file management system.
• Don’t forget to empty the bin! When you delete files on your computer’s hard-drive they are still stored in the deleted files ‘bin’ (clarify how this applies to your specific operating system and software, as well as intra-office networks). This ‘rubbish’ will need to be emptied from the ‘bin’ regularly.
• Information that is stored electronically becomes fragmented on a computer’s hard-drive, meaning it is not stored (or retrieved, or used) as efficiently as it could be. That is why it is important to regularly run a ‘de-frag’ on your PC.