Thursday, April 21, 2011
Articles about Quadratics, Sound and Cation Exchange Capacity
I have a few more articles published in eHow on a range of topics. The first is about computing the Cation Exchange Capacity (CEC) for soils. I have used this number to estimate heavy metal and nutrient uptake for soils in conjunction with on-site sewage disposal systems. The CEC along with Percent Base Saturation also has use in determining soil fertility and how best to apply nutrients to the soil.
Wednesday, April 13, 2011
How to Install a rainbarrel
Rain barrels are becoming a popular way to conserve water, by storing rain water for alter use, and not using good drinking water just to water plants. Here is an article I wrote on installing rain barrels:
How to Catch and Store Rain Water
How to Catch and Store Rain Water
Sunday, April 10, 2011
Friday, April 8, 2011
More articles published in eHow
I recently had two more articles published. The first has to do with water pollution.
The three types of water pollution.
The second has to do with wind power.
The drawbacks to vertical wind turbines.
Thanks for coming by and reading my work, I hope you find it useful.
The three types of water pollution.
The second has to do with wind power.
The drawbacks to vertical wind turbines.
Thanks for coming by and reading my work, I hope you find it useful.
Friday, March 18, 2011
New eHow articles
I have published two more eHow articles, one on a math topic and another on hydrology.
How to find the Greatest Common Factor of Polynomials
How to Develop IDF Curves
Both were interesting and fun to write. Hopefully make for good reading as well.
How to find the Greatest Common Factor of Polynomials
How to Develop IDF Curves
Both were interesting and fun to write. Hopefully make for good reading as well.
Monday, February 28, 2011
More eHow articles
I have another eHow article published.
How to install corrugated polyethylene pipe
I have plenty more titles in the pipeline!
How to install corrugated polyethylene pipe
I have plenty more titles in the pipeline!
Sunday, February 27, 2011
How to make a portable water level sensor
I wrote this article for eHow, and it was published a little while back. I took a picture for the article reference which was not included when it was published. Therefore, I am printing it here with a link to the article.
The picture shows some of the parts of the sensor. The PVC fittings in the foreground are the 1 1/2" PVC Cap, the the 1 1/2" X 3/4" PVC adapter, and the 1/2" PVC cap and plug. The silver object on the lower right is a sensor that I have used quite a bit for monitor wells.
The silver sensor was constructed from a 1" PVC cap and a 1" x 3/4" copper terminal end, with a float constructed of two 1/2" PVC caps glued together. The reed switch is from a security system window sensor that mounts in a 1/4" hole, drilled in to the cap. The sensor is hung by the long screw eye mounted in the top sensor. The wire is a two conductor microphone wire that I am not sure is available anymore.
Here is the link to the article. Have fun!
The picture shows some of the parts of the sensor. The PVC fittings in the foreground are the 1 1/2" PVC Cap, the the 1 1/2" X 3/4" PVC adapter, and the 1/2" PVC cap and plug. The silver object on the lower right is a sensor that I have used quite a bit for monitor wells.
The silver sensor was constructed from a 1" PVC cap and a 1" x 3/4" copper terminal end, with a float constructed of two 1/2" PVC caps glued together. The reed switch is from a security system window sensor that mounts in a 1/4" hole, drilled in to the cap. The sensor is hung by the long screw eye mounted in the top sensor. The wire is a two conductor microphone wire that I am not sure is available anymore.
Here is the link to the article. Have fun!
Tuesday, February 8, 2011
How to Calculate Overburden Pressure
OVERVIEW
The pressure due to soil overburden is important to know in order to design stable foundations, load bearing walls, and footings under the ground surface. This pressure is due to the weight of the soil layers above, as well any materials on top of the soil, such as concrete or ice. The presence of saturated soils at the design elevation can have a significant impact on overburden pressure as well. For the purpose of this discussion, overburden does not include solid rock, and the point of concern must be at the surface of underlying solid bedrock, or above the bedrock.
STEP 1.
Calculate the pressure due to the soil alone acting on the point at the elevation of concern, Eo. This point is typically located beneath more than one layer of soil. Use a table with a row for each separate soil layer, or substrate, with a value for each layer's density and depth in separate columns.
If there is water present, divide the soil layer where the water into two row entries, one for dry condition, and one row for saturated condition below the dry. For the dry layers, the soil pressure at the bottom of the layer is the sum of the dry density multiplied by the layer depth for that soil.
The bottom layer will be the layer containing the elevation Eo where we are calculating the pressure.
The layer depth will then extend from the bottom of the upper layer to the Eo elevation.
For example, for a Dry Gravel with a top elevation of 98.0 feet and a bottom elevation of 92.0 feet, the density in place is 125 lbs per cubic foot (pcf). In the table row for this layer, place a value of 98.0 in the first column, 92.0 in the second column, 6.0 in the third column (98.0 - 92.0 = 6.0), and 125.0 in the fourth column,
The total pressure due to this layer is then (98.0 - 92.0) * 125 = 750 pounds per square foot (psf). Place the value for the pressure due to each layer in the next column (fifth column) of the table.
STEP 2.
For saturated soils, reduce the calculated soil pressure due to the water being displaced by the soil. The density of the soil that is saturated is computed by taking the dry density of the soil minus the density of water. The density of water is 62.4 lbs/cu.ft. at 50 deg F. For the saturated layers, the soil pressure at the bottom of the layer is the dry density, less the density of water, multiplied by the layer depth for that soil. Be sure to use similar units, for example, use feet of soil and pounds per cubic feet for density.
In our example, the Eo elevation is 88.0 feet. The layer depth extends from the bottom of the dry gravel layer at 92.0 feet to 88.0 feet. Place 92.0 in the first column, 88.0 in the second column, and 4.0 in the fourth column.
Saturated gravel has a dry density of 125 pcf, so the wet density is then 62.6 pcf, so place this value in the fourth column. The total pressure from wet gravel layer, which is 4.0 feet thick, would be 250.4 psf. Place the value for the pressure due to each wet layer in the fifth column of the table.
STEP 3.
Now the total pressure at Eo can be computed. Sum the pressure computed due to each of the overlying layers which have been entered into the fifth column of the table. The total pressure is the sum of all these soil layers. For the two layers in our example, the total of the layers is 750.0 + 250.4 = 1000.4 psf.
TIP
A close approximation of soil density may be obtained from Standard Penetration Testing (SPT) and from examination of extracted split barrel samples. These tests are standardized by the American Society for Testing and Materials (ASTM). The ASTM also outlines a thin walled extraction cylinder method so that soils are less disturbed by the sampling method.
WARNINGS
REFERENCES
ASTM: Standard Penetration Test [http://www.astm.org/Standards/D1586.htm]
Essentials of Soil Mechanics by David MCarthy [http://www.amazon.com/Essentials-Soil-Mechanics-Foundations-Geotechnics/dp/0131145606/ref=dp_ob_title_bk?ie=UTF8&qid=1296526528&sr=8-10]
The pressure due to soil overburden is important to know in order to design stable foundations, load bearing walls, and footings under the ground surface. This pressure is due to the weight of the soil layers above, as well any materials on top of the soil, such as concrete or ice. The presence of saturated soils at the design elevation can have a significant impact on overburden pressure as well. For the purpose of this discussion, overburden does not include solid rock, and the point of concern must be at the surface of underlying solid bedrock, or above the bedrock.
STEP 1.
Calculate the pressure due to the soil alone acting on the point at the elevation of concern, Eo. This point is typically located beneath more than one layer of soil. Use a table with a row for each separate soil layer, or substrate, with a value for each layer's density and depth in separate columns.
If there is water present, divide the soil layer where the water into two row entries, one for dry condition, and one row for saturated condition below the dry. For the dry layers, the soil pressure at the bottom of the layer is the sum of the dry density multiplied by the layer depth for that soil.
The bottom layer will be the layer containing the elevation Eo where we are calculating the pressure.
The layer depth will then extend from the bottom of the upper layer to the Eo elevation.
For example, for a Dry Gravel with a top elevation of 98.0 feet and a bottom elevation of 92.0 feet, the density in place is 125 lbs per cubic foot (pcf). In the table row for this layer, place a value of 98.0 in the first column, 92.0 in the second column, 6.0 in the third column (98.0 - 92.0 = 6.0), and 125.0 in the fourth column,
The total pressure due to this layer is then (98.0 - 92.0) * 125 = 750 pounds per square foot (psf). Place the value for the pressure due to each layer in the next column (fifth column) of the table.
STEP 2.
For saturated soils, reduce the calculated soil pressure due to the water being displaced by the soil. The density of the soil that is saturated is computed by taking the dry density of the soil minus the density of water. The density of water is 62.4 lbs/cu.ft. at 50 deg F. For the saturated layers, the soil pressure at the bottom of the layer is the dry density, less the density of water, multiplied by the layer depth for that soil. Be sure to use similar units, for example, use feet of soil and pounds per cubic feet for density.
In our example, the Eo elevation is 88.0 feet. The layer depth extends from the bottom of the dry gravel layer at 92.0 feet to 88.0 feet. Place 92.0 in the first column, 88.0 in the second column, and 4.0 in the fourth column.
Saturated gravel has a dry density of 125 pcf, so the wet density is then 62.6 pcf, so place this value in the fourth column. The total pressure from wet gravel layer, which is 4.0 feet thick, would be 250.4 psf. Place the value for the pressure due to each wet layer in the fifth column of the table.
STEP 3.
Now the total pressure at Eo can be computed. Sum the pressure computed due to each of the overlying layers which have been entered into the fifth column of the table. The total pressure is the sum of all these soil layers. For the two layers in our example, the total of the layers is 750.0 + 250.4 = 1000.4 psf.
TIP
A close approximation of soil density may be obtained from Standard Penetration Testing (SPT) and from examination of extracted split barrel samples. These tests are standardized by the American Society for Testing and Materials (ASTM). The ASTM also outlines a thin walled extraction cylinder method so that soils are less disturbed by the sampling method.
WARNINGS
- Estimates of density may be used, but large variations of natural in-place densities do occur.
- The water (or glacial ice, etc) maybe be above the soil surface. Subtract the density of water from all soils in the first case, and add the total weight of ice in the second case.
REFERENCES
ASTM: Standard Penetration Test [http://www.astm.org/Standards/D1586.htm]
Essentials of Soil Mechanics by David MCarthy [http://www.amazon.com/Essentials-Soil-Mechanics-Foundations-Geotechnics/dp/0131145606/ref=dp_ob_title_bk?ie=UTF8&qid=1296526528&sr=8-10]
Monday, January 17, 2011
Volvo Electric C30
Volvo, long renowned for its safe and practical cars, is working on the forefront of automotive technology. They are now developing a full electric (plug-in) vehicle for use as a commuting car or in an urban situation. By using an existing platform of the Volvo C30, a compact 2 door hatchback, the car enables low impact driving with a very functional vehicle.
The C30 is currently sold in the US with a turbocharged 5 cylinder gasoline engine that makes 227 horsepower. Volvo has removed the drivetrain and in its place, installed a lithium ion battery pack down the central spine of the vehicle, with a 111 HP electric motor driving the front wheels. By placing the battery on the center of the C30, the battery is protected by the outer elements of the vehicle. Crash tests have proven this to be a very safe and reliable design, with forces experienced during crash testing causing no damage to the battery. A crashed C30 has been displayed at the Detroit Auto Show demonstrating this technology.
Currently, Volvo is testing a fleet of the electric C30's in the frigid environs of their home city of Gotenburg Sweden. Volvo is teaming with the local electric utility, and with a group of volunteer citizens, in order to fully test the electric vehicle under all conditions. Feedback and data from that experience has helped to design the this next generation of electric C30's. Test locations for this generation has not been disclosed.
If all goes well, we can anticipate that fully electric vehicles from Volvo will be introduced into the US in the next few years. No estimate of costs are yet available. The C30 will join the anticipated diesel/electric hybrid V70, which is expected in the EU sometime in 2012.
The C30 is currently sold in the US with a turbocharged 5 cylinder gasoline engine that makes 227 horsepower. Volvo has removed the drivetrain and in its place, installed a lithium ion battery pack down the central spine of the vehicle, with a 111 HP electric motor driving the front wheels. By placing the battery on the center of the C30, the battery is protected by the outer elements of the vehicle. Crash tests have proven this to be a very safe and reliable design, with forces experienced during crash testing causing no damage to the battery. A crashed C30 has been displayed at the Detroit Auto Show demonstrating this technology.
Currently, Volvo is testing a fleet of the electric C30's in the frigid environs of their home city of Gotenburg Sweden. Volvo is teaming with the local electric utility, and with a group of volunteer citizens, in order to fully test the electric vehicle under all conditions. Feedback and data from that experience has helped to design the this next generation of electric C30's. Test locations for this generation has not been disclosed.
If all goes well, we can anticipate that fully electric vehicles from Volvo will be introduced into the US in the next few years. No estimate of costs are yet available. The C30 will join the anticipated diesel/electric hybrid V70, which is expected in the EU sometime in 2012.
Subscribe to:
Posts (Atom)