Category Archives: Engineering

Geothermal Power in Alaska

Geothermal Power in Alaska Holds Hidden Model for Clean Energy, how it works:

1) 165 F water, pumped three-quarters of a mile from Chena’s 700-ft.-deep production well, enters the evaporator. After circulating through pipes, the water, now 135 F, is reinjected into the reservoir at a well 300 ft. from the power plant.
2) The refrigerant R-134a fills the shell of the evaporator. Heat transferred from the 165-degree water causes the refrigerant to vaporize without the two liquids actually coming into contact.
3) The vapor is expanded supersonically through the turbine nozzle, causing the turbine blades to rotate at 13,500 rpm. This turns a generator at 3600 rpm, producing electricity.
4) 40 F water, siphoned from a shallow well 33 ft. higher in elevation than the plant, enters the con-denser without the aid of a pump. It circulates through pipes before being returned 9 degrees warmer to Monument Creek.
5) Vapor exiting the turbine fills the shell of the condenser, where the 40 F water returns the refrigerant to liquid form.
6) A pump pushes the refrigerant back to the evaporator, generating the pressure that drives the entire cycle so that it may start anew.

Science and Engineering Instructional Webcasts

doFlick offers user-generated educational, technical and instructional videos on science and engineering. Examples include: Simple Circuits – How to do a basic leak test in vacuum systems – Bacteria in the Human Mouth – Transverse Standing Waves – Pulsed Layer Deposition Overview

The site offers a short videos on science and engineering topics (plus some other topics as well). The site fills a niche that is different that any other site I have seen. The videos are largely tips on lab or engineering techniques or edited labs. These are videos that might appear on network TV but they are exactly the type of resource that makes the internet great. Lets build this resource: upload your own webcasts. There is a great advantage to short targeted online videos (compared to full course lectures – which are also great) because the short targeted videos allow for targeted linking specifically to the video content you want to link to.

This is definitely worth adding to your bookmarks. Or you can just bookmark our directory of science and engineering videos.

Fancy Camera Flash Trigger

Some neat discussion of the engineering behind the RadioPopper P1 is included on the site:

The RadioPopper was designed to solve specific problems faced by event and wedding photographers. Most of us already own a pair or more of the various pro flash units from our camera manufacturers. These flashes are tied closely to the metering systems of our cameras
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Radio flash triggering devices allow a more consistent triggering means – but they lack any ability to dynamically adjust the flash power as the situation changes.
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With RadioPopper you’re no longer forced to choose between usability and reliability. Enjoy all the utility and features built into your existing Canon and Nikon flash units while overcoming the single weak link of the wireless system – the “line of sight” infrared communication setup.

The radiopopper blog has interesting posts and discussion. Via: Engineering for the People – Radio Triggers

Who Killed the Software Engineer?

Computer Science Education: Where Are the Software Engineers of Tomorrow? by Dr. Robert B.K. Dewar and Dr. Edmond Schonberg

Over the last few years we have noticed worrisome trends in CS education. The following represents a summary of those trends:
1. Mathematics requirements in CS programs are shrinking.
2. The development of programming skills in several languages is giving way to cookbook approaches using large libraries and special-purpose packages.
3. The resulting set of skills is insufficient for today’s software industry (in particular for safety and security purposes) and, unfortunately, matches well what the outsourcing industry can offer. We are training easily replaceable professionals.
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As faculty members at New York University for decades, we have regretted the introduction of Java as a first language of instruction for most computer science majors. We have seen how this choice has weakened the formation of our students, as reflected in their performance in systems and architecture courses.
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Every programmer must be comfortable with functional programming and with the important notion of referential transparency. Even though most programmers find imperative programming more intuitive, they must recognize that in many contexts that a functional, stateless style is clear, natural, easy to understand, and efficient to boot.

An additional benefit of the practice of Lisp is that the program is written in what amounts to abstract syntax, namely the internal representation that most compilers use between parsing and code generation. Knowing Lisp is thus an excellent preparation for any software work that involves language processing.

This is an excellent article: any CS students or those considering careers as programmers definitely should read this. Also read: Computer Science Education.

via: Who Killed the Software Engineer?

Dewar, a professor emeritus of computer science at New York University, believes that U.S. colleges are turning out programmers who are – there’s no nice way to say this – essentially incompetent.

Sails for Modern Cargo Ships

photo of Sky Sail in action

Kite-powered ship sets sail for greener future

A cargo ship pulled by a giant, parachute-shaped kite will leave Germany on Tuesday on a voyage that could herald a new “green” age of commercial sailing on the high seas.
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During the journey from Bremen to Venezuela, the crew will deploy a SkySail, a 160 square metre kite which will fly more than 600ft above the vessel, where winds are stronger and more consistent than at sea level. Its inventor, Stephan Wrage, a 34-year-old German engineer, claims the kite will significantly reduce carbon emissions, cutting diesel consumption by up to 20 per cent and saving Â£800 a day in fuel costs. He believes an even bigger kite, up to 5,000 square metres, could result in fuel savings of up to 35 per cent.

From the Sky Sails site:

The planned product range contains towing kite propulsion systems with a nominal propulsion power of up to 5,000 kW (about 6,800 HP). On annual average fuel costs can be lowered between 10-35% depending on actual wind conditions and actual time deployed. Under optimal wind conditions, fuel consumptions can temporarily be reduced up to 50%.

Go Engineering!

Bicycle Engineering Blog

Cozy Beehive, where technology and engineering are given their atypical and due status in the sport of cycling by Ron in Buffalo, New York (mechanical engineer and aspiring cyclist). An example of what you will find:

Companies blend fibers with synthetic fibers for better properties and added with composite material (made in mats by processes like needle punching, thermoforming or compression moulding). Saab, led by GM did this to its door panels in the early part of this century. Others sandwich the fibers between composites like carbon fiber or polyurethane foam by the same processes. So interestingly, these fibers have extensive industrial applications. (I didn’t know that, until now! Learning is fun, boy!)

Following the ideas from the automotive sector, the bicycle industry has been quick to adopt this idea. By using the twill composite hybrid sandwich technique, Museeuw frames can be made with a combination of fiber and carbon composite that supposedly gives it a plush ride, without losing any stiffness.

Google India Women in Engineering Award 2008

The award is open to full time woman students at recognized institutions majoring computer engineering or related fields in their 2nd to final years of a bachelor’s program and all students from a master’s or PhD program. Student must have a cumulative of at least 4.0 on a 5.0 scale, 8.0 on a 10.0 scale, or equivalent. The application deadline is January 31st. Apply online for this new award.

Statistics for Experimenters Review

Disclosure, I am a bit biased – William G. Hunter was my father. But I agree with this review of Statistics for Experimenters: Design, Innovation, and Discovery , 2nd Edition posted by George Samaras

Superb! If you are involved, in any way, with science or engineering, you need this book on your shelf (after you have carefully read it twice). My only complaint is that I found out about it circuitously reading Prof. Box’s “Improving Almost Anything”; I was curious what the often cited BHH reference was. I think someone should have a word with the publisher’s marketing department; if we don’t know about it, how are we supposed to buy it?

George Box, Stu Hunter and Bill Hunter authored the first edition book in 1978 and the second edition in 2005.

I maintain Statistics for Experimenters web site. Visit the page to find resources, or to let us know about resources (data sets, exercises, etc.) for those using the book.

The Loop Stitch

The how stuff works site does a great job of providing interesting explanations of. un-surprisingly, how things work. The design of of the web site is less good, in my opinion – way to much non-content (the content fills up maybe 15% of my screen on this link for example (once I scroll down it might improve to about 30% content): The Loop Stitch:

The most important element of a lock-stitch mechanism is the shuttle hook and bobbin assembly. The bobbin is just a spool of thread positioned underneath the fabric. It sits in the middle of a shuttle, which is rotated by the machine’s motor in synch with the motion of the needle.

Just as in a chain-stitch machine, the needle pulls a loop of thread through the fabric, rises again as the feed dogs move the fabric along, and then pushes another loop in. But instead of joining the different loops together, the stitching mechanism joins them to another length of thread that unspools from the bobbin.

When the needle pushes a loop through the thread, the rotary shuttle grips the loop with a hook. As the shuttle rotates, it pulls the loop around the thread coming from the bobbin. This makes for a very sturdy stitch.

See the site for a graphic that does a much better job of making it clear, how it works, I think.

Rubick’s Cube Solving Lego Mindstorms Robot

Lego Mindstorms have really really provided some great tools for home robot engineering. JP Brown has several examples on his web site including this CubeSolver:

The longest part of the this project involved writing the color-recognition software. I downloaded the Logitech Quick Cam SDK from the Logitech Developer’s site (the LEGO Vision Cam is a repackaged Logitech Quick Cam) and used VB5 to write a fairly decent program (click the Code link for source). The color recognition is fairly robust (about one error every two cubes when well-calibrated), but not perfect, so I incorporated a feature that requires you to confirm that each face has been correctly scanned (and, optionally, allows you to correct the input manually) before it scans the next face.
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My early attempts at building a cube solver were all stymied by grips that slipped. The worm-56t gave enough torque to turn, but the fingers couldn’t hang on and the grip was simply pried apart as the grabber rotated around the stationary cube face. I thought about changing the device’s name to ButterFingers.

I rebuilt the left and right grabbers six times (and the bottom grabber four times) trying elastic bands, Technic shocks, and pneumatics, before I came up with an adequate grip mechanism. In the present version, an axle runs from a motor through the center of the large Technic turntable to a worm screw. The worm screw turns two 24t gears mounted either side of the worm inside the body of the grabber.

Other home engineering favorites: Awesome Cat Cam – Windmill for Electricity – Lego Autopilot First Flight