Friday, April 29, 2016

Vehicle Safety Checks Monday

 Zombie mechanic eats brains and oil!

Dear students:

Please consider taking advantage of free vehicle check-outs this Monday afternoon May 2nd, 12.30 – 4pm, in front of the Activities Building.

Is your vehicle’s mechanical-genetic code complete and fit for purpose? Is it being out-competed on the great Road of Life by all the swanky new hybrids? Or has it turned down an evolutionary dead-end already? Does it need protection under the Endangered Species Act? Does it need to go to the great Outdoor Backyard Non-Running Vehicle and Oil-Tolerant Wildlife Sanctuary that composes a significant amount of Maine’s acreage, including my own? Or should we just ask one of our CommUnity Firearms Safety experts to put the old dog out of its misery?

In any case, don’t miss the opportunity Monday to have the old junker checked out thoroughly. In particular, don’t risk being stranded someplace remote, dangerous, or worst of all, without cell phone service!

Before you get in your olde ruste bucket and drive off into the wild blue yonder for a fine non-academic summer, let the experienced mechanics and other techy-geeky students of this year’s team of volunteers check the poor beast out.

We will check your tire pressures and pump them up if necessary, check and top off the oil and other fluids, and finally and perhaps most usefully, if your CHECK ENGINE light is on, we will use our computer reader to “pull” your trouble codes so you can finally know just what it is that your poor neglected automobile has been trying to tell you all these months.

(Did you know you can save lots of gas by keeping your car’s tires at the proper pressures? And that tire pressure changes as the weather warms and cools with the seasons, so you have to check them regularly! Did you know that a blown oxygen sensor is easy to fix and can save on gas too? Did you know that low oil level can kill your car’s engine? Well, now you know.)

Each participant will receive a written report on the serviceability of their vehicle, with details of any trouble codes and what they mean.

The college accepts no responsibility for the use or misuse of any of the information we give you about your vehicle, or for your car’s safety after you leave the campus, but we do suggest that it’s always better to know than not to know. In most cases.

(Employees are welcome too. Thanks to the Maintenance and Student Affairs departments for aid in providing this service.)

Be safe, drive safe.

Mick Womersley
Professor and Head Grease Monkey
(not necessarily in that order)

Tuesday, April 19, 2016

A moment of Zen

From "Bird and Moon Comics."

Click to enlarge.

GL 4003 Practice Exam

Biomass energy field trip

Students in PS3003 Sustainable Energy, including famous SEM students Michelle, Mac, Steven, Jared, and Sly, all visited former US Navy Commander Rick Holt's seven hundred acre working forest in Dixmont Maine, where we learned about forest management, with an emphasis on how biomass extraction for firewood, pellet, and chip is used as an adjunct to tree stand improvement practices.

Ricky first demonstrated the used of the "Biltmore" stick to estimate board feet content of a sawlog.

We then took about a mile and a half walking tour of the forest, inspecting tree stands in various stages of management. This is an area where future maple sawlogs and veneer logs are being encouraged by selective cutting of lower value, damaged, diseased, and otherwise competing trees, which are then used for firewood. Ricky explained that it helps when making a veneer log to increase the light availability of the target tree only slowly, or sprouts will appear on the trunk, leading to knots, which reduce the value.

This was a tree cut to stop the spread of the sugar maple borer, a pest of maple trees. The road in the background is one of several Rick has built over the years to facilitate forest management and timber extraction. Rick was able to show us very clearly how the new roads, with proper culverts and water-splashes or "rock fords" are a great improvement on the old skid roads and trails. Eroded skid trails from former harvest areas are easy to see on the landscape, even though it's been forty-five years since the harvesting was done.

Here's the view from the dam on Ricky's pond.

The landscape we see here is quite new, since the whole area was logged off and used for extensive sheep farming in the 1800s. Ricky has a map showing the names of some of the settlers. Most of the names are north British, which is not surprising, considering that extensive sheep farming of very similar upland ranges was developed in Britain. The settlers would have known how to manage the landscape and climate for sheep. Americans used more woolen clothing and ate more lamb and mutton back then, so there would have been a better market for the products than there is now.

Many thanks to Ricky for being willing to share his knowledge and his land with our students. Ricky is a great forester, but he's also a very good teacher, so the field trip was especially worthwhile.

Sunday, April 10, 2016

Intergenerational design criteria

Proposed by sustainability economics author and commentator Andrew Simms, published today in The Guardian (here):

  • Employment and broader economic return on investment - how much value to the broader economy does investment in different technologies bring; in other words, what is its economic multiplier effect?
  • Environmental return on investment - how efficiently does an investment lower carbon emissions and minimise other toxic pollutants and contribute to a healthy environment?
  • Energy return on investment - how much energy is generated for the amount of money invested to produce that energy?
  • Security return on investment - how much does the technology contribute to domestic energy security and what other security risks does it carry?
  • Transition return on investment - how does it contribute, comparatively to the speed and scale of deployment of low carbon energy generating capacity?
  • Conviviality return on investment - the degree to which a technology can be responsive to and supportive of a society’s or a community’s own vision and pathway for its development, and that of future generations.

Tuesday, April 5, 2016

Sustainable Energy second midterm

Sustainable Energy
Midterm Exam

Professor Womersley

Due Monday April 25th in class

This is a take-home exam. Answer all questions, showing work where necessary to demonstrate skills or learning, diagrams if asked or if it helps. If you don’t know or can’t work out an answer, put down what you do know. You may research answers.  You may discuss them with the instructor. You may not confer with other students. Submit electronically, multiple files allowed including statistical files in JMP, Excel, or Smith’s. Use PowerPoint for posters unless alternately agreed with the instructor.

Exam is 20% of grade for class, 10% given for each problem below

Only one problem:

Create a cost analysis for an industrial wind farm for an appropriate Maine site. Specify make, model and installed cost of equipment, wind speed estimates (from wind maps), rated and actual power produced. Use a Weibull model. Provide simple payback and amortized (levelized) cost effectiveness calculations, including economic profits and levelized cost per watt. (Use an annuity model for amortized/levelized costs.)

(See me for help if you didn’t get enough practice doing all this in class or lab.)

Your blank Weibull model spreadsheet is available at

PETM video, for GL 4003