Archive for August, 2008

How Long Should You Idle Before It’s More Economical to Turn Off Your Engine?

Monday, August 25th, 2008

This question has intrigued me for a long time–even more so in these days of higher gas prices. I seem to remember that in the polluted Missoula valley where I grew up in the 70’s and 80’s, air quality officials advocated turning off your car if you knew you’d be idling for longer than 30 seconds. That was in the old days of carbureted motors, which were much less efficient to start up again.

Looking around the Internet lately, that recommendation is down around 10 seconds, with the break-even point actually being around 6 or 7 seconds. One reason for shorter recommended idle times is due to the increased efficiency with which modern, fuel-injected motors start. The Green Lantern section of the Slate website (http://www.slate.com/id/2192187/) provides an interesting article on this notion, written by Brendan E. Koerner, entitled “Is an Idle Car the Devil’s Workshop?” The estimated annual savings of this tactic (about $34 a year according to the article) is a little disappointing, but the notion of such a short break-even point is intriguing.

Fixing the Old Drill

Sunday, August 24th, 2008
Old Black & Decker Drill

Old Black & Decker 3/8" Drill

Today I tackled a project I’d been putting off for over a year: fixing my old drill. It’s not a terribly valuable drill; it’s old, probabaly of about 1974 vintage. It wasn’t very expensive to begin with.  I saw one like it on e-Bay for $3. However, this drill has sentimental value, so I wasn’t about to just throw it away. Besides, it’s variable speed and reversible–kind of handy as a second drill when working on a project. I’d abused it pretty badly one day, trying to mix a batch of mortar with one of those big mixing paddles. It just didn’t have the power for the job and got really hot! Since then it would only run when held in certain positions, and sometimes I’d have to jiggle it to make it go. There are three screws on the back that allow the back cover to come off. This gives access to the brushes, the switch, and the wire connections. (I wish I’d remembered to take a picture of the disassembled drill. It would have been much more interesting, but I’m not taking it apart again for a picture.) Upon inspecting the brushes, I found that they weren’t making good contact with the armature. There was plenty of material left, but the brush springs had lost their tension and weren’t pushing the brushes firmly against the armature. Getting the drill too hot that day had ruined them. I replaced the springs with some old alternator brush springs I had lying around, and now the drill runs again, good as new!

Essential Conditions for Curriculum Integration With Technology

Friday, August 22nd, 2008

The International Society for Technology in Education (ISTE) publishes two web sites that address the conditions necessary to integrate technology into the curriculum. One site addresses essential conditions for students http://cnets.iste.org/students/s_esscond.html, and the other addresses essential conditions for teachers http://cnets.iste.org/teachers/t_esscond.html. Both are similar in stating the conditions required to accomplish this. Conditions mentioned on both sites include a shared vision with support by administration; access to newest technology; knowledge of content standards and resources; technical support; teachers with technology skills; student-centered teaching; on-going assessment to determine if technology is making a difference in learning; support by community partners; and adequate, on-going funding. In addition, the teacher site lists professional development that supports technology integration.

I can’t argue with any of the conditions on this list. I believe they are all important. If we pick and choose the ones we are comfortable addressing, then we will probably not accomplish our goal of creating an effective learning environment that prepares students to face the challenges and decisions of the future. In the next sections, I will offer my opinion of where my district (the nation’s 5th largest) stands on each condition listed above, and where applicable, what should be done about it.

Shared Vision with Support by Administration

By reading the district’s mission statement, it is difficult to know whether its vision truly includes technology integration at the highest levels. The district’s vision/mission statement is “… students will have the knowledge, skills, attitudes, and ethics necessary to succeed academically and will practice responsible citizenship.” It doesn’t mention preparing students for the future, nor does it even mention technology. To “succeed academically” can be interpreted so many ways. Lately it seems to mean pass the test to achieve AYP. The mission statement should be rewritten to include mention of preparing students to live in a future that will be dominated by technology. Even the district’s technology vision statement is weak: “It is the vision of the … District that information and communication technologies are essential for improving student achievement.”

Access to Newest Technology

I feel that the district does do a good job of trying to provide access to new technology. It would be an impossible task (although a nice standard to aim for) to continually provide all students and teachers access to the newest technology. Equipment and infrastructures are extremely expensive and time-consuming to purchase, maintain, and train people to use. In order to afford a reasonable degree of high technology, balanced against the cost of new technology, the district sometimes keeps its equipment in use past the point where it might be considered technically obsolete. When schools are updated though, it is with equipment that is state of the art at the time it is purchased.

Knowledge of Content Standards and Resources

Many teachers have limited knowledge of technology content standards and resources. At one time, technology integration and meeting technology standards were stressed much more than they are today. Since the No Child Left Behind act was passed, administrators have been under intense pressure to meet test score standards for basic skills. This has left little time and energy to consider technology integration into the curriculum. It has also shifted the focus of technology use from research and self-directed learning to computer assisted drills and diagnostic-prescriptive testing. Until there is less pressure on administrators to deliver high test scores, the focus probably will not change.

Technical Support

The district does a good job of providing technical support, especially for such a large enterprise. There are several technical departments, including Technology Deployment Services, Networking Services, and User Support Services, all of which provide support either directly or indirectly to end users. In addition, almost all schools have access to an on-site educational computing strategist (ECS) who is usually able to provide timely support for common user errors and minor technical problems. In addition, the ECS is tasked with facilitating technology integration into instruction. Probably the biggest impact to facilitate integration of technology into the curriculum though, would be to give all schools a full time ECS. Presently ECS’s cover two to three schools each.

Teachers with Technology Skills

The collective degree of technology skills in the district is slowly increasing. Most of the improvement is not a result of staff development efforts. Rather, it is a result of older teachers retiring and younger, more tech-savvy teachers taking their places. Many young teachers use technology to accomplish their tasks without a second thought because they have been exposed to it since they were young. As the teaching force continues to turn over, teacher technology skills will not be as big an issue as it once was.

Student-Centered Teaching

From what I see in elementary schools, there is not much student-centered teaching occurring. There is a great deal of drill and diagnostic-prescriptive teaching of the skills that will be on the test. As mentioned above, the No Child Left Behind Act (NCLB) can take credit for this situation. Also stated above, this probably will not change until the test score pressure is relieved.

Ongoing Assessment of Technology’s Effectiveness

It is not good style to sound like a broken record (nor to use such a cliché perhaps), but most teachers and administrators have been burdened with so many tests that measure whether students are meeting “key” academic standards, and with so much pressure to demonstrate achievement, that little is going on that measures the effectiveness of integrating technology. At the moment, there may be little point in such a measure. As explained above, a disproportionate amount of technology resources has been diverted from high-level learning to computer assisted instruction and diagnosis.

Support by Community Partners

Many schools have corporate partners that help fund projects and purchases. An outstanding example of a district-wide community partner is the foundation that helps fund and administer the district’s e-mail system. This affords all employees the ability to communicate electronically with anyone else, both within and outside the district. At the site level, probably the biggest community support schools receive is from parent-teacher organizations. These organizations hold fund raisers and attempt to help schools fund a variety of needs, including minor technology needs.

Adequate, On-going Funding

Schools in the district, with the exception of Title I schools, perhaps,  rely mainly on district funding to provide upgrades and major equipment purchases. One could argue that the amount of funding will never be “adequate.”  Schools supplement the software and hardware issued by the district with whatever funds they can scrape together. Schools work hard to find the money to buy the extras: digital cameras, printers, software, etc.

Professional Development that Supports Technology Integration

In the past, the district used to allow teachers to be released during the instructional day for training. Substitutes were provided to cover their classes. Because of funding problems and a substitute shortage, this arrangement is no longer allowed. Coupled with the pressures of NCLB mentioned above, little wide-spread attention has been given to professional development that supports technology integration. Most technology-related training that now occurs is concerned with productivity–for example, accessing test scores and using electronic grade books. Training times before school and during teacher preparation periods are now consumed with meetings and trainings that focus on how to improve test scores. Until the rules about teacher training during the instructional day are changed, it will continue to be difficult to find sufficient time blocks to do meaningful technology integration training.

Conclusion

The district does a few things on the list of conditions well, especially technical support and attempting to provide access to new technologies. However, there are so many conditions that are not mastered, I feel that we are not even close to truly achieving meaningful technology integration into the curriculum on a large scale. Thus, with a few exceptions we are far from creating an effective learning environment that prepares students to face the challenges and decisions of a future driven by technology.

The Effect of Copyright Piracy on Teachers

Monday, August 18th, 2008

Before discussing the effect of copyright piracy on teachers, a couple of definitions should be helpful. A useful, working definition of copyright found at SearchSecurity.com is, “… the copyright law provides that the owner of a (an intellectual) property has the exclusive right to print, distribute, and copy the work, and permission must be obtained by anyone else to reuse the work in these ways.” Piracy is the duplication of copyrighted material which is used, sold, or given to others to use without permission.

In these days of the Internet and high technology, it is easier than ever to violate copyright. Computer programs, files, and pictures can easily be duplicated and distributed electronically. Many technology users don’t even believe they are breaking the law by sharing others’ work or property in this way.

One of the worst effects of copyright piracy is that it takes away the incentive to create. If companies or authors know that their work will be stolen and distributed to others, they may not be motivated to produce the product, or they may settle on producing a product that is of lower quality than it could have been. Lakhan states, “The lack of education concerning intellectual property has lead to infringement, disrespect for other’s ideas, nearly ten billion dollars of U.S. financial loss, and worst of all, the hindrance of creativity and ingenuity.” This can result in a lack of quality products being produced that can be used in the classroom.

Another effect of copyright piracy is to drive up the price of software and other educational materials. As noted in the preceding paragraph, copyright infringement results in an incredible monetary loss. Software companies and distributors may raise their prices in an attempt to recover some of the loss. Many schools and teachers cannot afford materials as it is. The result of this is that many teachers end up being copyright pirates themselves as they attempt to provide their students with relevant materials. Rothman quotes Friedman, “… inadequate funding caused a dilemma for the teachers who, while sensitive to the ethical problem of copying, were also unwilling to compromise students’ education.”

Copyright piracy (infringement) is a huge problem, not only within educational institutions, but throughout most of the world. In spite of laws, penalties, and anti-piracy measures, the problem continues.

————————————-

“What is Copyright?” Search Security.com. 27 Jun 2005. <http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci211841,00.html>

Lackhan, Shaheen E. ” Stop Piracy with Edification: Intellectual Property Education in School.” Nov, 2002. < http://cogprints.org/2935/01/SchoolIPEdu.pdf >.

Rothman, David H. “Copyright and K through 12: Who Pays in the Network Era?” The Future of Networking Technologies for Learning. 19 Sept. 2001. <http://www.ed.gov/Technology/Futures/rothman.html>

Stoplights: The Great Equalizers

Wednesday, August 13th, 2008

I know I irritate my share of drivers as I putt through town from stoplight to stoplight in my under-powered 4-cylinder Jeep. I do my best, but there’s only so much you can do with 120 horsepower! To make it worse, subtract an additional 15 horses when the AC is running*. The guy in the dual-turbo PowerStroke® diesel F250 may not miss the 15 horsepower from his stable of 350 high-torque diesel-fed horses as he comes roaring around me, turbos screaming, cell phone glued to his ear. But I miss every one of them as I row through the gears to coax my little Jeep back up to something near the speed of the traffic going by. The funny thing is, when I get to the next light, there sits the guy in the F250! I can’t begin to tell you how often this happens. Often as I come rolling up, the light is just ready to turn green. Traffic lights do a good job of putting the mighty and the lowly in the same class.

* Dan’s Data Letters #129 http://www.dansdata.com/danletters129.htm

Prolonging the Life of Idler Pulleys

Sunday, August 10th, 2008

This weekend I changed the serpentine belt on my Jeep. Serpentine belts live up to their name and take a tortuous path through the drive pulley system of your motor. To keep a serpentine belt properly tensioned and to deflect it away from the areas it shouldn’t contact, a system of idler pulleys is used. Idler pulleys have a flat, smooth face against which the back side of the belt runs.  An idler pulley typically contains a sealed ball bearing, pressed into the center of the pulley, on which the pulley spins. After many thousands of miles, perhaps 60,000 (depending on driving conditions), the factory-packed grease will be pretty dry, and the bearing will begin to fail. If your bearing has rubber seals, you may be able to carefully pry them out with a couple small screwdrivers and pack the bearing with fresh grease. I performed this operation this past winter on the idler pulley next to the air conditioning pulley when it began chirping for a few seconds when started in the morning, and this weekend on the remaining idler. After cleaning the outer surfaces of the seals, I carefully pried them out of their seats and repacked the bearing with white lithium grease.  Then I pressed the bearing seals back into place and reinstalled the idler pulley.

Update: 8/22/08 So far (8 months for one and only a dozen days for the other), all is well.

How Do You Check for a Bad Belt?

A couple of months ago, I had my Jeep at the dealer to diagnose a fuel problem. You probably know that when you take a vehicle to a dealer, they usually look it over pretty carefully, looking for other work they might be able to perform for you. One of items on my inspection was “belt cracked.” Just looking at the wide surfaces of my belt while it was installed, I thought it looked pretty good and that the dealer was just trying to sell me a bill of goods. But, because the weather is hot and I hate the thought of being stranded in the hills with a cooling problem, I decided to replace it anyway. It wasn’t until I got the belt off and could look at its thin edge closely while bending it, that I could see the small cracks beginning to develop.  I had a momentary pang of guilt for my earlier bad thoughts about the dealer’s honesty. I learned a lesson about how to check for a bad belt.

The Cost of HD Storage

Sunday, August 10th, 2008

Last year, when I was looking around for a good buy on a large external HD, I was amazed by how cheap external HD storage works out to be. When I calculated the cost per GB, the best price I found was 24 cents per GB. I haven’t bought a floppy disc in a very long time, but I priced a box of 1.44 mb floppies, and they worked out to about 29 cents a disc, or 20.139 cents per MB!

If you bought the equivalent of a 500 GB drive in floppies, you would need 355,555 discs, and it would cost you $103,111 ! ….. Plus shipping! Plus storage! … and a pallet jack!

(A GB is 1024 MB; a floppy is 1.44 MB. That’s about 711 floppies per GB, or about $206 worth of floppies per GB. Compare that to your $20 1 GB pen drive! )

With an 8 foot ceiling, I calculate it would take a storage closet about 6 x 7 feet to hold all 355,555 discs if you threw away all the packaging material.

(A stack of 10 floppies with labels attached is about 16.13 cubic inches. There are 1728 cubic inches in a cubic foot.)

Someone should check my math. :)

The Difference Between Save & Save As

Sunday, August 10th, 2008

I’ve noticed that some students (and maybe their teachers) are not sure about when to use Save and when to use Save As. Here are some general rules that you might present if you discuss this topic:

Save As presents a dialog box that allows you to select where you want to save a document and what you want to name it. Save works behind the scenes because it already has that information.

Use Save or Save As if you create a new document and it has never been saved. No matter which you select in this case, if a document has never been saved, you’re going to get the Save As dialog box. I encourage students to routinely select Save unless they have a special reason to select Save As. (Read on.) This minimizes the chances that they will end up with several versions of the same document when they do multiple saves during a work session.

Use Save if you edit a document that has been saved before. In this case, Save will replace the older copy with the newer copy without bothering you about where to save it or what to name it.

Use Save As if you want to save a copy of a document in a different location or you want to save a copy of a document using a different name. My rule of thumb is to use Save unless this last case applies.

Using a GPS to Calibrate Your Odometer

Sunday, August 10th, 2008

Soon after I bought a GPS, I realized that my Jeep’s odometer was pretty inaccurate. That answered the question I had in the back of my mind about whether my over-sized tires came on the vehicle from the factory, or if the previous owner put them on. I’d expect the odometer to be reasonably accurate if the factory turned out the vehicle with the tire size in question. Without changing speedometer drive gears, tire sizes larger than original equipment will cause your speedometer to register slower than you’re actually going,  and less mileage will show on the odometer than you actually drive.

This could have implications for maintenance intervals, depending on how inaccurate the oversized tires cause the odometer to be. According to my math, when I’ve driven 3000 miles, my odometer will only register 2662.7 miles! Another way to look at it is: when my odometer shows 3000 miles, I will have actually driven 3380 miles.

How does the math work? On my way home from work, as soon as my (digital) odometer turned to the next mile, I recorded its mileage and zeroed the mileage counter on my GPS. By the time I got home, my odometer showed I’d driven 4.5 miles. The GPS showed I’d driven 5.07 miles. Solving a simple ratio problem will show the difference between any actual mileage and the mileage shown on the odometer. For example:

Odometer : GPS
4.5 miles : 5.07 miles = X miles : 3000 miles

This asks, “When I’ve actually driven 3000 miles according to the GPS, what will the odometer say?
To solve for X, multiply 3000 times 4.5, then divide by 5.07; answer = 2662.7

OR

Odometer : GPS
4.5 miles : 5.07 miles = 3000 miles : X miles

This asks, “When my odometer says I’ve driven 3000 miles, how many actual miles will I have driven?
To solve for X, multiply 3000 times 5.07, then divide by 4.5; answer = 3380

If I really want to change my oil after 3000 miles, I should set my maintenance interval to  2663. In reality, an extra 380 miles might not be too big a deal on a maintenance interval, depending on driving conditions.

If you don’t have a GPS, you can accomplish the same thing (with a little less accuracy) by relying on highway mileage markers. The larger distance you are able to compare, the more accurate your results will be.

The real solution to this problem is to replace the speedometer drive gear with one calibrated for the present tire size. For digital speedometers, I’m not sure if there actually is a gear, or if there is a sensor somewhere that detects driveshaft revolutions. If anyone knows what drives a Jeep TJ speedometer, please let me know.

Bug Screens on Radiators

Sunday, August 10th, 2008

On a trip home to Nevada from Montana in 2005, quite a few bugs met untimely deaths on my windshield. An equal number met their deaths on my radiator. That made me consider installing a bug screen in front of the radiator to keep dead bugs from plugging up the fins and eventually cutting down my vehicle’s cooling ability—especially since I was pulling a camper and the temperatures on the road were often over 100 F. I just didn’t quite get around to it until I returned to Southern Nevada, where bug screens are pointless, anyway. But I thought I’d order one on the Internet so I’d be prepared for next year’s trip. While searching, I ran across some articles that caution the reader about using bug screens. The authors claim that screens can significantly cut down on the amount of air reaching the radiator, and that perhaps a moderate amount of bugs splattered against the fins is preferable! I canceled the bug screen idea. Below are quotes from the sites and the original URLs of the complete articles. Some of these links are dead now but a trip to the Way Back Machine (http://www.archive.org/web/web.php) may bring them back to life.

from RV Cooling System Performance, by Chuck Arnold
http://thepowershop.com/index.php?pr=RV_Cooling

Bug screens in the absence of bugs block 20% of the airflow and thus kill cooling system efficiency. RV engines should not run with bug screen protected radiators in hot weather unless the bugs are so bad that the radiator is being plugged. The screen is almost always worse than the bugs.

from Canadian Driver: Keeping that Engine Cool by Jim Kerr
http://www.canadiandriver.com/articles/jk/at_000710.htm

Bug screens help keep the radiator fins from becoming plugged with bugs but they can also stop up to 40% of the airflow through the radiator. If it is necessary to use a bug screen, select one with as large as openings as possible.

from RV Times: Technical Info for the New RVer/Camper by Bob Martin
http://www.rvtimes.com/arch/help.html

The bug screen on the front of the engine grill is another contentious issue. Anything you put in front of the grill or radiator will hamper the proper flow of air to the radiator. To prove this statement, take an ordinary house fan that you would have for cooling or moving air in a room in your house. Now turn it on and feel the amount of airflow that you have. Now put the fan on the other side of your screen door and stand in front of the airflow. Notice the difference. On a vehicle, a screen can be enough to hamper the airflow to the extent that the engine does not cool properly.