High Output Solar Water Pasteurizer
There are more than a billion people who do not have reliable access to safe drinking water. These people are often disabled by waterborne diseases and become dependent on their community thus reducing the overall viability of the entire community.
The device described below is an improvement on most current devices used for solar water pasteurization because of the greatly increased quantity of water that can be made safe with a low input of solar heat and because its operation is automatic. The only attention required is keeping water in the input tank. The water is not boiled but merely heated to a temperature of at least 65 degrees C that will quickly kill any pathogenic organisms in it. The water is then cooled as its heat is transferred to the incoming water. The transfer of heat from the outgoing water to the incoming water is what permits the large increase in the amount of water that can be made safe.
This solar water pasteurizer can be made inexpensively using a thermostat, a metal cooking pot, copper tubing, insulation, and other low cost hardware. The thermostat can be the type that is used in automotive cooling systems. These are available in a choice of operating temperatures. The one that is used should be made for an operating temperature of at least 65 degrees C. if a higher temperature is used, the water will be more sterile, although it is generally agreed that 65 degrees C is sufficient for making the water safe. Be sure that the thermostat that is used closes completely at temperatures below its set temperature. Some thermostats have a small hole to permit a low flow at low temperatures. If there is such a hole, close it off. To connect the thermostat to the water feed tube, it is necessary to use an adapter to connect the small tube to the large flange that separates the two sides of the thermostat. A small funnel could be used or the top of an old spray can. The adapter can be soldered to the flange so that the incoming water must pass through the thermostat valve in order to get into the pot.
The water feed tank must be elevated above the level of the pot so that water will flow into the pot whenever the thermostat valve is open. The tank should be connected to the cooking pot by inexpensive 1/4 inch copper tubing. Inside the cooking pot the feed tube connects to the thermostat valve near the bottom of the pot that will open to admit water only when the temperature is high enough to pasteurize the water. The hot water output is taken from a tube that passes through the side of the pot near the top. This output water passes through another copper tube that is in close thermal contact with the tube carrying the water from the feed tank. The outgoing water must flow in the opposite direction from the incoming water. Binding the two tubes together with copper wire ensures that heat is easily transferred between the two tubes The incoming water is therefore heated by the hot water coming from the cooking pot.. This should be done for a distance that is sufficient for complete thermal transfer (the water in the two tubes should have reached very close to the same temperature). The pair of tubes must be insulated from the surrounding air to conserve the solar heat. Since the solar heat is recycled into the incoming water, the system can process much more water. The water enters the pot at almost the temperature that is necessary for pasteurization and needs very little additional heat. Thus, the output of safe water will be sufficient for many people. The feed tank can be made from any container that will hold enough water for an extended period of operation, To increase the minimum time that the water is kept heated, a series of baffles inside the cooking pot can control the path that the water takes from input to outlet. The cooking pot would be heated by sunlight in a solar stove. There are many very good designs for solar stoves to heat the cooking pot. Some require nothing more than a piece of glass, some aluminum foil, some black paint, and some corrugated cardboard from old boxes for insulation.
All of the materials needed for construction are inexpensive, readily available, and easily assembled with local labor. The major components of this system could be sold as a low cost kit for local assembly. To prevent the output water from becoming re-contaminated by airborne organisms care should be taken to keep contamination out. Use of a pressure cooker for the heated pot will keep contaminated air out, and is convenient because the cover will already have holes to connect the input and output tubes, and the cover will help transmit heat to the pot. Because heating the water will release dissolved air, be sure that the air can be vented without causing problems with the flow of output water. Eliminating any bends in the output tube that could trap air should be enough to avoid this problem. The reason that the thermostat is placed in the input feed line is because the thermostat can then compensate for changing water levels in the feed tank. This permits long periods of unattended operation.
This pasteurizer can be used indefinitely as there are no consumables, and no fuel is used. The flow rate is self-regulating. It automatically shuts down at night and adding mirrors to direct more sunlight to the solar stove can increase the output.
If the contaminated water source in not clear, then filter it through a piece of fabric to remove the particulates before putting it in the feed tank.
Friday, December 25, 2009
Tuesday, November 10, 2009
Inexpensive Transport of Fresh Water
Inexpensive Transport of Fresh Water
Fresh water is scarce in many areas on the earth and some of them are located near oceans or large seas. This proposal describes a method for moving fresh water from places where it is plentiful on a seacoast to other places where it is needed. This would make use of the ocean for low cost transportation of fresh water to benefit large arid coastal areas. It would also permit raising crops in areas now too dry for agriculture.
The water would be moved in bulk inside floating bladders. For example, on the west coast of North America fresh water is plentiful in the north but scarce in the south. The California current flows south along the coast and could be used to assist in moving fresh water to southern California. A similar condition exists on the east coast of Australia. Southeast Australia now has a major drought and could use water from the north, which is plentiful.
The fresh water could be pumped into large bladders, which would float on the salt water of the ocean and could be moved south with minimal towing, as the current would do most of the work. After arrival at the destination, and pumping the fresh water into reservoirs on shore, the empty bladders could be returned for refill. For this plan to be economical, the bladders would have to be very large. For example, they could be made in the shape of sausages, perhaps 100 ft in diameter and 1000 ft long. Ten of these could be strung together and slowly towed. This would deliver 1805 acre-feet of water. Los Angeles has a severe water shortage and is now considering desalination with a projected cost of $1080 per acre-foot. The value of the water delivered on each trip of the bladders would therefore be $1,950,000. This method will become even more attractive compared to desalinization as the cost of fossil fuel energy increases. It also might substantially replace present energy intensive, less sustainable irrigation schemes such as the current practice of transporting electrically pumped water in canals and pipes running over mountains from the Sacramento River Delta region to the Los Angeles area.
The bladder material should probably be the same as is used for large tarps. I am thinking of the common ones based on a woven fabric of polypropylene cords covered on both sides with layers of polyethylene fused to the fabric. The plastics can have pigment and UV inhibitors included so they will be protected from solar exposure. Fabrication of the bladders is easy. Overlapping the material by an inch or so and fusing it with heat makes the seams. This works because polyethylene melts between 120 and 130 degrees C and polypropylene melts at about 160 C. The tarps are commercially available with the short edge measuring up to 100 ft so we know that rolls of the tarp material of that width and probably any arbitrary length should be available.
Strong, durable, and inexpensive sausage shaped bladders can be constructed of this material. The material can be tapered down as the ends of the bladders are approached and finally clamped tightly to a large pipe fitting with a valve and coupling so that the bladders can be filled, emptied and coupled to each other for transit.
The bladders could be inexpensively made very strong to survive the inertial forces involved in starting, turning and stopping them. The force of surging water due to the effects of inertia or rogue waves could be absorbed by elastic bands around the bladders near the ends. They should not be much affected by stormy weather because if they were not tightly filled, they would be transparent to the waves in the ocean, which would pass through them with little effect.
As they would be moving very slowly relative to the water around them, and the fabric that they are made from will not be tightly stretched, they would yield when contacted and gently push aside any debris that they encountered on the water surface. If there is a problem with floating debris damaging the bladders, they could be protected by using old carpets as fenders along the water line of the bladders. A mast with a flashing light and radar reflector could be mounted at the end of each bladder to warn boat traffic away.
For the particular case of delivering water to southern California, In order to get large quantities of fresh water without political problems, I think that it may be necessary to go further north than the California border to get the fresh water. The Columbia River is fed by the runoff from the Canadian Rockies and a large fraction of its fresh water flows into the pacific. The US Army corps says that the average annual runoff of this river is 198,000,000 acre-feet. The amount taken for southern California would be a very tiny fraction of that. Where the Fraser River flows into Puget Sound at Vancouver BC Canada is another possible source. The small amount transported could be very significant for southern California or western Mexico. There is a lot more water available further north from other rivers that could also be used. The transit time would be longer, but the current would still do most of the work.
This scheme could possibly be used for water delivery to any arid coastal area. For example, the south and east coasts of the Mediterranean Sea are arid and the north and west coasts have adequate water. The effects of global warming seem to be reducing the rainfall on the south Mediterranean coast and northern Africa, but increasing it in Europe so it seems that that the need and supply situation will improve with time. In regions such as this, where there is little natural current to assist in the movement of the bladders, a very energy efficient method of moving them would be to use a very long cable that would be pulled from a fixed point. This fixed point could be a ship that is anchored. The long cable would pull the bladder up to the ship using a winch. The ship would then move to a new anchor point, while paying out the cable, then pull the cable in again. This would necessitate following a route with water shallow enough to anchor, usually near a shoreline.
This would obviously need considerable investment capital because the design and construction of the large bladders and construction of the necessary shore facilities for filling and emptying the bladders would be costly. However, the facilities and materials would be reusable and should have a long useful life. There would be necessary political connections, commitments, and payments for the system to function. However, the high value and need for the fresh water delivered should result in a large economic gain despite the start-up costs,
Increasing the size of the bladders should be cost effective as the amount of material needed and the energy required for towing increases more slowly than the capacity of the bladders. There would be a practical limit on size because of the need to transport the empty bladders back for refill. Carrying them on a ship or barge would probably be more efficient than towing the empties, but that may depend on local conditions.
This idea will increase in value with time because of the continuing depletion of the aquifers in many arid but highly populated seacoast regions. Fresh water will become increasingly scarce and desalination is very energy intensive and is becoming more costly as oil and gas are depleted
There are other economic and political considerations. In my opinion, the sale of the water to private companies could result in very undesirable consequences. Privatization of water systems in many areas has resulted in large increases in rates, government corruption, and compromise of public safety. The question of who should own the water is an important consideration that must not be ignored. The water is a natural resource that is owned by the citizens and they should pay for the operation of the distribution system but not for the water itself. The way to structure the transport deals should be for the government agencies involved to deal directly with each other. They could hire contractors to do the work of transporting the water, but should never sell the water to a private company. The price that users pay may need to be set higher than the cost of transport and distribution in order to limit consumption to the amount of water available, but the excess income in this case should go to the general funds of the governments involved, and not to corporate profit.
Another consideration is that the level of fresh water removal from a source river system should be kept low enough that there would be no significant effects on the natural biological systems of the river and so that there is enough extra water available to permit a considerable increase in local consumption without the necessity of reducing the amount of water provided to the receiving area, which may be expected to become dependent on its continued availability. The rate of extraction and transport of fresh water will need to vary seasonally according to the rate of river flow and therefore the water storage at the delivery point must be large enough so that the rate of consumption can remain reasonably constant. It may be that the bladders can be economically used for storage as well as transportation. The costs of this transportation system are not small, but the energy requirements are low. Operating the system will create many jobs. The alternative sources of fresh water such as desalinization are still more costly and have large energy requirements with much greater climate change consequences.
With the help of several people on a web based discussion group, I have found out that there have been previous attempts to transport water with similar technology. I had difficulty finding out about the previous activity because what I was calling bladders, they referred to as Medusas the most advanced operation was by Nordic Water Supply ASA, which transported water from Turkey to Cyprus. Unfortunately, due to some equipment failures and other problems, this company, after operating since 1994 declared bankruptcy in May of 2003. I believe that there have been other small-scale operations in the Mediterranean area, some of which may still be operating. Due to the length of time that this sort of operation has been in operation or attempted, it seems likely that there are no patent related obstacles to further development. Perhaps now, with the greater economic need, and using some of the ideas described above, there can be some successful large-scale applications of this system.
I have done some daydreaming about other uses for the tarp material, not just transportation, but storage. The one with the most potential seems to be the creation of artificial lakes in areas where the rainfall is very seasonal. For example, the regions where there are seasonal monsoon rains with lots of water available, in fact, way too much during the rainy season, so that there are disastrous floods with loss of life and property.
In regions that are mostly flat, such as Bangladesh, (which is barely above sea level), it seems that a good plan would be to start in the beginning of the dry season, excavate a large area, as deeply as possible, use the removed material to raise the level of the surrounding area, then surround the excavation with a high levee and line the bottom of the new lake with impermeable material such as the tarp fabric.
When the rains come, use massive pumps to fill the lake with water from the swollen rivers. This avoids the usual flooding for two reasons: one is that the area in now higher because of the material removed to make the lake, and the other reason is that the excess river water was pumped into the lake which should be filled to the top of the levees, and will now have a level well above the surrounding land. During the following dry season, the lake water is used for irrigation and other needs. The lake can be stocked with fish, such as tilapia, so that it will be productive of food as well.
Obviously, this is not a cheap project. It requires massive earth moving equipment, massive pumps, and the energy to run them. However, it may be cheap compared to the cost of not doing it and also considering the increased year round agricultural production that it makes possible. The elevated land will also provide protection during the periodic cyclones (hurricanes) that flood the land with seawater and often cause major loss of life due to drowning. Even if the raised land is not high enough to avoid flooding in the storm, the levees will be much higher and can be topped with concrete storm shelters for the local population.
I don't know if any of this is politically possible, or where, but I can dream…
Bill Isecke
bisecke@gmail.com
1 201 836 8403
Fresh water is scarce in many areas on the earth and some of them are located near oceans or large seas. This proposal describes a method for moving fresh water from places where it is plentiful on a seacoast to other places where it is needed. This would make use of the ocean for low cost transportation of fresh water to benefit large arid coastal areas. It would also permit raising crops in areas now too dry for agriculture.
The water would be moved in bulk inside floating bladders. For example, on the west coast of North America fresh water is plentiful in the north but scarce in the south. The California current flows south along the coast and could be used to assist in moving fresh water to southern California. A similar condition exists on the east coast of Australia. Southeast Australia now has a major drought and could use water from the north, which is plentiful.
The fresh water could be pumped into large bladders, which would float on the salt water of the ocean and could be moved south with minimal towing, as the current would do most of the work. After arrival at the destination, and pumping the fresh water into reservoirs on shore, the empty bladders could be returned for refill. For this plan to be economical, the bladders would have to be very large. For example, they could be made in the shape of sausages, perhaps 100 ft in diameter and 1000 ft long. Ten of these could be strung together and slowly towed. This would deliver 1805 acre-feet of water. Los Angeles has a severe water shortage and is now considering desalination with a projected cost of $1080 per acre-foot. The value of the water delivered on each trip of the bladders would therefore be $1,950,000. This method will become even more attractive compared to desalinization as the cost of fossil fuel energy increases. It also might substantially replace present energy intensive, less sustainable irrigation schemes such as the current practice of transporting electrically pumped water in canals and pipes running over mountains from the Sacramento River Delta region to the Los Angeles area.
The bladder material should probably be the same as is used for large tarps. I am thinking of the common ones based on a woven fabric of polypropylene cords covered on both sides with layers of polyethylene fused to the fabric. The plastics can have pigment and UV inhibitors included so they will be protected from solar exposure. Fabrication of the bladders is easy. Overlapping the material by an inch or so and fusing it with heat makes the seams. This works because polyethylene melts between 120 and 130 degrees C and polypropylene melts at about 160 C. The tarps are commercially available with the short edge measuring up to 100 ft so we know that rolls of the tarp material of that width and probably any arbitrary length should be available.
Strong, durable, and inexpensive sausage shaped bladders can be constructed of this material. The material can be tapered down as the ends of the bladders are approached and finally clamped tightly to a large pipe fitting with a valve and coupling so that the bladders can be filled, emptied and coupled to each other for transit.
The bladders could be inexpensively made very strong to survive the inertial forces involved in starting, turning and stopping them. The force of surging water due to the effects of inertia or rogue waves could be absorbed by elastic bands around the bladders near the ends. They should not be much affected by stormy weather because if they were not tightly filled, they would be transparent to the waves in the ocean, which would pass through them with little effect.
As they would be moving very slowly relative to the water around them, and the fabric that they are made from will not be tightly stretched, they would yield when contacted and gently push aside any debris that they encountered on the water surface. If there is a problem with floating debris damaging the bladders, they could be protected by using old carpets as fenders along the water line of the bladders. A mast with a flashing light and radar reflector could be mounted at the end of each bladder to warn boat traffic away.
For the particular case of delivering water to southern California, In order to get large quantities of fresh water without political problems, I think that it may be necessary to go further north than the California border to get the fresh water. The Columbia River is fed by the runoff from the Canadian Rockies and a large fraction of its fresh water flows into the pacific. The US Army corps says that the average annual runoff of this river is 198,000,000 acre-feet. The amount taken for southern California would be a very tiny fraction of that. Where the Fraser River flows into Puget Sound at Vancouver BC Canada is another possible source. The small amount transported could be very significant for southern California or western Mexico. There is a lot more water available further north from other rivers that could also be used. The transit time would be longer, but the current would still do most of the work.
This scheme could possibly be used for water delivery to any arid coastal area. For example, the south and east coasts of the Mediterranean Sea are arid and the north and west coasts have adequate water. The effects of global warming seem to be reducing the rainfall on the south Mediterranean coast and northern Africa, but increasing it in Europe so it seems that that the need and supply situation will improve with time. In regions such as this, where there is little natural current to assist in the movement of the bladders, a very energy efficient method of moving them would be to use a very long cable that would be pulled from a fixed point. This fixed point could be a ship that is anchored. The long cable would pull the bladder up to the ship using a winch. The ship would then move to a new anchor point, while paying out the cable, then pull the cable in again. This would necessitate following a route with water shallow enough to anchor, usually near a shoreline.
This would obviously need considerable investment capital because the design and construction of the large bladders and construction of the necessary shore facilities for filling and emptying the bladders would be costly. However, the facilities and materials would be reusable and should have a long useful life. There would be necessary political connections, commitments, and payments for the system to function. However, the high value and need for the fresh water delivered should result in a large economic gain despite the start-up costs,
Increasing the size of the bladders should be cost effective as the amount of material needed and the energy required for towing increases more slowly than the capacity of the bladders. There would be a practical limit on size because of the need to transport the empty bladders back for refill. Carrying them on a ship or barge would probably be more efficient than towing the empties, but that may depend on local conditions.
This idea will increase in value with time because of the continuing depletion of the aquifers in many arid but highly populated seacoast regions. Fresh water will become increasingly scarce and desalination is very energy intensive and is becoming more costly as oil and gas are depleted
There are other economic and political considerations. In my opinion, the sale of the water to private companies could result in very undesirable consequences. Privatization of water systems in many areas has resulted in large increases in rates, government corruption, and compromise of public safety. The question of who should own the water is an important consideration that must not be ignored. The water is a natural resource that is owned by the citizens and they should pay for the operation of the distribution system but not for the water itself. The way to structure the transport deals should be for the government agencies involved to deal directly with each other. They could hire contractors to do the work of transporting the water, but should never sell the water to a private company. The price that users pay may need to be set higher than the cost of transport and distribution in order to limit consumption to the amount of water available, but the excess income in this case should go to the general funds of the governments involved, and not to corporate profit.
Another consideration is that the level of fresh water removal from a source river system should be kept low enough that there would be no significant effects on the natural biological systems of the river and so that there is enough extra water available to permit a considerable increase in local consumption without the necessity of reducing the amount of water provided to the receiving area, which may be expected to become dependent on its continued availability. The rate of extraction and transport of fresh water will need to vary seasonally according to the rate of river flow and therefore the water storage at the delivery point must be large enough so that the rate of consumption can remain reasonably constant. It may be that the bladders can be economically used for storage as well as transportation. The costs of this transportation system are not small, but the energy requirements are low. Operating the system will create many jobs. The alternative sources of fresh water such as desalinization are still more costly and have large energy requirements with much greater climate change consequences.
With the help of several people on a web based discussion group, I have found out that there have been previous attempts to transport water with similar technology. I had difficulty finding out about the previous activity because what I was calling bladders, they referred to as Medusas the most advanced operation was by Nordic Water Supply ASA, which transported water from Turkey to Cyprus. Unfortunately, due to some equipment failures and other problems, this company, after operating since 1994 declared bankruptcy in May of 2003. I believe that there have been other small-scale operations in the Mediterranean area, some of which may still be operating. Due to the length of time that this sort of operation has been in operation or attempted, it seems likely that there are no patent related obstacles to further development. Perhaps now, with the greater economic need, and using some of the ideas described above, there can be some successful large-scale applications of this system.
I have done some daydreaming about other uses for the tarp material, not just transportation, but storage. The one with the most potential seems to be the creation of artificial lakes in areas where the rainfall is very seasonal. For example, the regions where there are seasonal monsoon rains with lots of water available, in fact, way too much during the rainy season, so that there are disastrous floods with loss of life and property.
In regions that are mostly flat, such as Bangladesh, (which is barely above sea level), it seems that a good plan would be to start in the beginning of the dry season, excavate a large area, as deeply as possible, use the removed material to raise the level of the surrounding area, then surround the excavation with a high levee and line the bottom of the new lake with impermeable material such as the tarp fabric.
When the rains come, use massive pumps to fill the lake with water from the swollen rivers. This avoids the usual flooding for two reasons: one is that the area in now higher because of the material removed to make the lake, and the other reason is that the excess river water was pumped into the lake which should be filled to the top of the levees, and will now have a level well above the surrounding land. During the following dry season, the lake water is used for irrigation and other needs. The lake can be stocked with fish, such as tilapia, so that it will be productive of food as well.
Obviously, this is not a cheap project. It requires massive earth moving equipment, massive pumps, and the energy to run them. However, it may be cheap compared to the cost of not doing it and also considering the increased year round agricultural production that it makes possible. The elevated land will also provide protection during the periodic cyclones (hurricanes) that flood the land with seawater and often cause major loss of life due to drowning. Even if the raised land is not high enough to avoid flooding in the storm, the levees will be much higher and can be topped with concrete storm shelters for the local population.
I don't know if any of this is politically possible, or where, but I can dream…
Bill Isecke
bisecke@gmail.com
1 201 836 8403
Wednesday, October 07, 2009
THE WAVE POWERED PUMP
THE WAVE-POWERED PUMP AND SOME IMPORTANT APPLICATIONS
On reading a book called Waves and Beaches by Willard Bascom (Anchor Books, 1980), I found a description of what I thought was a very clever device. It was a wave powered pump invented by John Isaacs, a simple and versatile device. Since that time I have often thought about applications for it. The pump consists of a float connected to a long pipe that hangs below it in the water. The pipe is fitted with a check valve that permits water to flow in only one direction. As the float and pipe move up and down with the waves, the water column in the pipe is forced to move along with the pipe but only when the pipe is moving in the direction that forces the valve in the pipe to close and then, due to the momentum of the moving water, it continues to move in that direction even when the motion of the pipe reverses and the valve opens. This action results in a continuous flow of water through the pipe. The volume of water pumped through the pipe is proportional to the cross sectional area of the inside of the pipe and to the maximum speed of the up-down motion of the pipe. For a given size float, it can pump a lot of water at low pressure or a little water at high pressure. A short fat pipe will pump a lot of water at low pressure and a long thin pipe will pump less water, but at high pressure. The pressure due to the flow of the water in the pipe is proportional to the length of the pipe. For construction details see below.
Here are some proposed applications:
Ocean Fertility Augmentation
In most areas of the tropical oceans the warm surface water is depleted of nutrients and therefore mostly devoid of life. However, the cold deep water below has lots of nutrients. In fact, the most fertile regions of the oceans are the areas where the cold deep water mixes with the surface water such as off the coast of Peru and in the polar regions
In places where the cold water is close enough to the surface to reach with a wave powered pump the deep water can be mixed with the surface water and the fertility of the ocean can be increased in that area thus providing a productive fishery where there was none before.
Where warm surface water and cold subsurface water are both available near land there are additional possibilities. For example, the temperature differential between the cold water and the warm surface water can be used to generate power (Ocean Thermal Energy Conversion). Or the cold water can be piped to land and used for air conditioning and then the water can be piped to large ponds where the dissolved nutrients and sunlight support the growth of algae and other marine life that can be harvested for food.
Hurricane Control
Hurricanes extract energy from warm surface waters on the ocean. If this warm water could be mixed with cooler water from below then the intensity of hurricanes in that region would be reduced. This is a job that the pumps can do.
The pumps will drift with the ocean currents and will have to be retrieved by ships before they reach shallow water and are destroyed. They can be then transported and redeployed. Locating the pumps can be made easy by mounting a radar reflector or even a radio beacon on them. Periodically removing the pumps from the water also eliminates the problem of bio-fouling as seaweed and barnacles can not tolerate the prolonged drying caused by transport on the deck of a ship. The pumps can be modified to remain in the desired area for a longer time if there is a predictable relationship between the direction of the ocean currents and the prevailing wind direction. The pumps can then move themselves in any desired direction. This would be accomplished by placing a wind tail on one side of the float so that the float always points upwind. The water discharge can then be directed horizontally to propel the pump in the desired direction relative to the wind. The pumps can even be made steerable by remote control if the orientation of the wind vane can be servo controlled by radio. It is not necessary for every pump to be controlled in this way as many pumps can be tethered together and steered by one.
Of course, since the pump takes its energy from the waves, it reduces the intensity of the waves. This may reduce shoreline damage during a storm. Using these pumps to control hurricanes would require a lot of pumps covering a large area. However, when compared to the cost of the devastation caused by hurricanes, the pumps will be cheap. They need only be deployed in the path of a large hurricane heading for a populated area and can be stored on land between uses.
Elimination of the “Dead Zone” in the Gulf of Mexico
The Gulf of Mexico has a very large region called the “Dead Zone” in which the subsurface life has been killed off by lack of oxygen. This is a result of fertilizer runoff from farm fields carried to the gulf by the Mississippi River. The fresh water from the river contains fertilizer and it flows out into the gulf over the denser salt water. The fertilizer causes a bloom of algae that eventually sinks below the surface and decomposes. This decomposition uses up all of the available oxygen in the deep water and so the animal life there is killed. There is very little mixing of the surface water with the de-oxygenated water below because the surface water is lighter than the deep salty water below.
The dead zone could be eliminated if the surface water, which has plenty of oxygen, could be mixed with the water below. The wave powered pump could do this.
The best way to do the mixing is to pump salty water from below and mix it with the surface water. This will permit the growth of the algae while making the surface water salty and reducing the density difference of the surface water with the deep salty water below. Reducing the density difference between the surface water and the deep water will permit the oxygenated surface water to mix naturally with the deeper water and restore the oxygen to the deep water.
The alternative method of mixing is to pump the fresh surface water down into the salty water below. This will result in the algae being transported from the surface to the deep water where it will die from lack of light and then consume more oxygen in its decomposition.
There are many other similar “dead zones” in the world that can be treated in the same way. In many cases, the water is shallow enough so that strings of pumps can be anchored in place and left unattended for the duration of the seasonal “dead zone”.
The pumps may actually pay for themselves, because the algae will then be the basis of a healthy food chain and valuable fish and other marine products can be harvested from these well nourished areas.
Construction Details
The components of the pump are simple and inexpensive. The pipe can be made from PVC sewer pipe. This is available in fairly long lengths and is easily extended at any time by chemically welded couplings. The one way valve can be made by welding a coupling to one end of the main pipe, cutting the coupling in half, welding a short section of wider pipe whose inner diameter is equal to the outer diameter of the coupling to the coupling, cutting a series of slots along the length of the short wide pipe, placing in this pipe a ball which cannot fit into the main pipe, then capping the end of the wide pipe to make the ball captive. This will permit water to flow out of the main pipe but not into it. Placing this valve at the bottom of the main pipe pumps water downward, placing it at the top pumps it upward. There are other ways of making check valves (one way valves) also
One way of making the large float would be to pass the main pipe through a piece of rigid plastic foam encased in a shell made of fiberglass The float should be flat and wide so that it will follow the surface of the waves. The motion of the water in a wave is not simply up and down but in fact is circular. The float must therefore tolerate a lateral motion of the water with the same amplitude as the vertical motion. The float should be flexibly fastened to the pipe in such a way that the float can tilt relative to the pipe but not move vertically along it. For example, a gimbal mechanism provides this sort of coupling. It is also possible to use a flexible pipe or hose which permits the float to move laterally. In this case the hose should be under tension with a weight at the bottom and the float at the top always pulling. In any case, the float and the upper section of the pipe must be both strong and flexible so that they will not be broken by waves. The pumps are not a hazard to shipping since they can be made very visible by mounting a pole on the float and putting a bright flag on top and at night they are easily avoided if they have radar reflectors. Even if they are hit, they will break up and not damage the ship because they are made of light plastic.
The above ideas are only a few possibilities. There may many others that are also practical and useful. You are encouraged to give some thought to this and I would like to hear from you to get your reactions and ideas.
Bill Isecke
541 Queen Anne Road
Teaneck, New Jersey 07666
Isecke@yahoo.com
1 201 836 8403
On reading a book called Waves and Beaches by Willard Bascom (Anchor Books, 1980), I found a description of what I thought was a very clever device. It was a wave powered pump invented by John Isaacs, a simple and versatile device. Since that time I have often thought about applications for it. The pump consists of a float connected to a long pipe that hangs below it in the water. The pipe is fitted with a check valve that permits water to flow in only one direction. As the float and pipe move up and down with the waves, the water column in the pipe is forced to move along with the pipe but only when the pipe is moving in the direction that forces the valve in the pipe to close and then, due to the momentum of the moving water, it continues to move in that direction even when the motion of the pipe reverses and the valve opens. This action results in a continuous flow of water through the pipe. The volume of water pumped through the pipe is proportional to the cross sectional area of the inside of the pipe and to the maximum speed of the up-down motion of the pipe. For a given size float, it can pump a lot of water at low pressure or a little water at high pressure. A short fat pipe will pump a lot of water at low pressure and a long thin pipe will pump less water, but at high pressure. The pressure due to the flow of the water in the pipe is proportional to the length of the pipe. For construction details see below.
Here are some proposed applications:
Ocean Fertility Augmentation
In most areas of the tropical oceans the warm surface water is depleted of nutrients and therefore mostly devoid of life. However, the cold deep water below has lots of nutrients. In fact, the most fertile regions of the oceans are the areas where the cold deep water mixes with the surface water such as off the coast of Peru and in the polar regions
In places where the cold water is close enough to the surface to reach with a wave powered pump the deep water can be mixed with the surface water and the fertility of the ocean can be increased in that area thus providing a productive fishery where there was none before.
Where warm surface water and cold subsurface water are both available near land there are additional possibilities. For example, the temperature differential between the cold water and the warm surface water can be used to generate power (Ocean Thermal Energy Conversion). Or the cold water can be piped to land and used for air conditioning and then the water can be piped to large ponds where the dissolved nutrients and sunlight support the growth of algae and other marine life that can be harvested for food.
Hurricane Control
Hurricanes extract energy from warm surface waters on the ocean. If this warm water could be mixed with cooler water from below then the intensity of hurricanes in that region would be reduced. This is a job that the pumps can do.
The pumps will drift with the ocean currents and will have to be retrieved by ships before they reach shallow water and are destroyed. They can be then transported and redeployed. Locating the pumps can be made easy by mounting a radar reflector or even a radio beacon on them. Periodically removing the pumps from the water also eliminates the problem of bio-fouling as seaweed and barnacles can not tolerate the prolonged drying caused by transport on the deck of a ship. The pumps can be modified to remain in the desired area for a longer time if there is a predictable relationship between the direction of the ocean currents and the prevailing wind direction. The pumps can then move themselves in any desired direction. This would be accomplished by placing a wind tail on one side of the float so that the float always points upwind. The water discharge can then be directed horizontally to propel the pump in the desired direction relative to the wind. The pumps can even be made steerable by remote control if the orientation of the wind vane can be servo controlled by radio. It is not necessary for every pump to be controlled in this way as many pumps can be tethered together and steered by one.
Of course, since the pump takes its energy from the waves, it reduces the intensity of the waves. This may reduce shoreline damage during a storm. Using these pumps to control hurricanes would require a lot of pumps covering a large area. However, when compared to the cost of the devastation caused by hurricanes, the pumps will be cheap. They need only be deployed in the path of a large hurricane heading for a populated area and can be stored on land between uses.
Elimination of the “Dead Zone” in the Gulf of Mexico
The Gulf of Mexico has a very large region called the “Dead Zone” in which the subsurface life has been killed off by lack of oxygen. This is a result of fertilizer runoff from farm fields carried to the gulf by the Mississippi River. The fresh water from the river contains fertilizer and it flows out into the gulf over the denser salt water. The fertilizer causes a bloom of algae that eventually sinks below the surface and decomposes. This decomposition uses up all of the available oxygen in the deep water and so the animal life there is killed. There is very little mixing of the surface water with the de-oxygenated water below because the surface water is lighter than the deep salty water below.
The dead zone could be eliminated if the surface water, which has plenty of oxygen, could be mixed with the water below. The wave powered pump could do this.
The best way to do the mixing is to pump salty water from below and mix it with the surface water. This will permit the growth of the algae while making the surface water salty and reducing the density difference of the surface water with the deep salty water below. Reducing the density difference between the surface water and the deep water will permit the oxygenated surface water to mix naturally with the deeper water and restore the oxygen to the deep water.
The alternative method of mixing is to pump the fresh surface water down into the salty water below. This will result in the algae being transported from the surface to the deep water where it will die from lack of light and then consume more oxygen in its decomposition.
There are many other similar “dead zones” in the world that can be treated in the same way. In many cases, the water is shallow enough so that strings of pumps can be anchored in place and left unattended for the duration of the seasonal “dead zone”.
The pumps may actually pay for themselves, because the algae will then be the basis of a healthy food chain and valuable fish and other marine products can be harvested from these well nourished areas.
Construction Details
The components of the pump are simple and inexpensive. The pipe can be made from PVC sewer pipe. This is available in fairly long lengths and is easily extended at any time by chemically welded couplings. The one way valve can be made by welding a coupling to one end of the main pipe, cutting the coupling in half, welding a short section of wider pipe whose inner diameter is equal to the outer diameter of the coupling to the coupling, cutting a series of slots along the length of the short wide pipe, placing in this pipe a ball which cannot fit into the main pipe, then capping the end of the wide pipe to make the ball captive. This will permit water to flow out of the main pipe but not into it. Placing this valve at the bottom of the main pipe pumps water downward, placing it at the top pumps it upward. There are other ways of making check valves (one way valves) also
One way of making the large float would be to pass the main pipe through a piece of rigid plastic foam encased in a shell made of fiberglass The float should be flat and wide so that it will follow the surface of the waves. The motion of the water in a wave is not simply up and down but in fact is circular. The float must therefore tolerate a lateral motion of the water with the same amplitude as the vertical motion. The float should be flexibly fastened to the pipe in such a way that the float can tilt relative to the pipe but not move vertically along it. For example, a gimbal mechanism provides this sort of coupling. It is also possible to use a flexible pipe or hose which permits the float to move laterally. In this case the hose should be under tension with a weight at the bottom and the float at the top always pulling. In any case, the float and the upper section of the pipe must be both strong and flexible so that they will not be broken by waves. The pumps are not a hazard to shipping since they can be made very visible by mounting a pole on the float and putting a bright flag on top and at night they are easily avoided if they have radar reflectors. Even if they are hit, they will break up and not damage the ship because they are made of light plastic.
The above ideas are only a few possibilities. There may many others that are also practical and useful. You are encouraged to give some thought to this and I would like to hear from you to get your reactions and ideas.
Bill Isecke
541 Queen Anne Road
Teaneck, New Jersey 07666
Isecke@yahoo.com
1 201 836 8403
Sunday, February 22, 2009
Election Reform for USA
Election Reform
I'm discouraged. How do we get politicians to represent ordinary citizens instead of billionaires, media companies, and rich multinational corporations? Reform has been made nearly impossible by the destruction of the electoral system, which has now become clearly dysfunctional. It is a money-driven system for protecting the current rulers.
In the current electoral system money is the single most important factor in success. This has debased and corrupted our political system. Most Americans know this and want reform.
However, most current office holders have their positions because they were able to raise the enormous amounts of money required for a winning candidacy. As a result, most elected politicians now (correctly) believe that their political survival depends on access to this money. In fact, as long as getting elected requires the enormous expenditures that it now does, elected officials will always be indebted to the sources of that money. The fact that big business, the military, and the rich nearly always get the legislation and political favors that they want is a perfectly rational and necessary consequence of the way that elections are financed. Even when a public-spirited president or member of congress gets elected, the large majority of our so-called representatives still do the bidding of the powers that put them in office and prevent any real reform
For our current government, politics is always more important than the welfare of the citizens. It is clear that the reform of the system will be blocked by the best efforts of those who profit from the current system. It now seems clear that nothing can be done until conditions get much worse. It may take a major economic and social disruption on the scale of the great depression of the 1930s to get most people to understand how badly they have been represented and to demand the major reforms that we need.
Possibly, a new third party will arise from the anger of the exploited majority and sweep most current officeholders out of office. Then we could get a new political majority that is not yet bought and paid for. There would then be an opportunity to make fundamental changes in the electoral system and to limit the uncontrolled power of corporations.
A necessary first step to clean up the system and restore political representation to ordinary citizens is to completely eliminate the need for raising money in elections. This is not easy, but it can be done. The key is to get the necessary exposure without the necessity of big money. It would also be good to limit the time devoted to the campaigns, perhaps two months for a presidential election and one month for all others.
All election related ads and debates should be carried on TV and radio without charge as a condition of the broadcast license. Paid political ads should be outlawed. The so-called "issue ads" placed to influence public opinion for the benefit of a particular candidate or party must also be banned during election periods
Obviously, airtime must be allocated in a fair and reasonable way. Candidates should qualify for minimal basic airtime simply by meeting the signature qualification for listing on the ballot. This would be a low fixed percentage of those who would be eligible to vote in that election. In order to avoid having the air time dominated by the many marginal candidates yet still permit them to be heard, it will be necessary to have unequal shares of air time. Here is one suggestion. The major parties should each start by sharing about 50% of the total time. The remaining airtime would be divided among the minor party candidates. Each week the airtime would be adjusted proportionally based on the preceding week's impartial polling results plus a basic allowance. In this way, a minor party candidate whose message resonates with the voters will be able to increase his or her air time each week and will have at least a fighting chance of beating a major party candidate.
In addition to the broadcasts, a taxpayer financed mailing containing statements from each candidate should be sent at least weekly during each election cycle. In these mailings each candidate will be free to comment on the positions and records of the other candidates as well as explaining his or her own position. This will result in a kind of running debate in print that everyone has access to. Each candidate can have equal space in this mailing, as the limits of airtime do not apply. The final mailing, arriving just before the election, should be devoted to candidates' final statements. At this point attacks on the opposing candidates and new charges should not be allowed because the other candidates will not be able to respond to them before the election.
The content of all of this material should be screened by a nonpartisan committee composed of nominees from membership supported watchdog groups of all political stripes such as the League of Women Voters, Cato Institute, Heritage Foundation, and Common Cause. If a candidate's material contains false or unverifiable statements then the screening committee will include a commentary pointing out the problem statements and include it following the candidate's material before publishing or broadcast. This should help to keep all the candidates honest. Censorship of the statements would be undesirable and possibly unconstitutional, but the constitution does not guarantee anyone's right to lie without being exposed.
It would be difficult to completely eliminate advocacy for particular parties or candidates outside of the formal structure of the campaign as outlined above. First amendment considerations preclude banning such things as print advertisements by individuals. Controlling advertising by corporations is a problem due to the fact that corporations are now considered to have the rights of actual people. That right is not in the constitution, and can be changed, but, given the present power of corporations, that will not happen anytime soon (with our current crop of politicians).
People should recognize that the credibility of such advertising is suspect compared to the fair treatment given to the candidates and their positions within the boundaries of the regular campaign. Since the broadcast media are owned by the people and are, or were until recently, required to be operated in the public interest, political broadcast advertising outside of the free airtime can be banned.
An important reform would be to get rid of the Electoral College system and adopt direct popular elections. Unfortunately this system is in the constitution, and, despite its dysfunctional nature, the states that benefit from it will do their best to keep it. A popular vote on it would probably get rid of it but that seems unlikely.
Another improvement would be to adopt the system used by several other democracies and have the voters rank the candidates. If there is no top rated candidate with a majority of the vote then the candidate with the lowest total vote is eliminated and the ballots recounted. This process continues until someone has a majority. This eliminates the spoiler effect of minor party candidates and the consequent reluctance to vote for them.
The result of these reforms will be the election of a candidate who is not indebted to big money contributors. The cost of running elections in this way would certainly be a trivial amount compared to the cost of even a few of the corrupt legislative favors that the large contributors now receive as the reward for the "election help" that they paid for.
The integrity of the election process must be insured by having voter verified paper trails for all voting and by having the process run by non-partisan election boards composed of citizens interested in keeping the process fair.
Election reform is an extremely important problem in America today. The importance of money in politics has crippled democracy and has resulted in a government by and for the wealthy and powerful.
Bill Isecke
I'm discouraged. How do we get politicians to represent ordinary citizens instead of billionaires, media companies, and rich multinational corporations? Reform has been made nearly impossible by the destruction of the electoral system, which has now become clearly dysfunctional. It is a money-driven system for protecting the current rulers.
In the current electoral system money is the single most important factor in success. This has debased and corrupted our political system. Most Americans know this and want reform.
However, most current office holders have their positions because they were able to raise the enormous amounts of money required for a winning candidacy. As a result, most elected politicians now (correctly) believe that their political survival depends on access to this money. In fact, as long as getting elected requires the enormous expenditures that it now does, elected officials will always be indebted to the sources of that money. The fact that big business, the military, and the rich nearly always get the legislation and political favors that they want is a perfectly rational and necessary consequence of the way that elections are financed. Even when a public-spirited president or member of congress gets elected, the large majority of our so-called representatives still do the bidding of the powers that put them in office and prevent any real reform
For our current government, politics is always more important than the welfare of the citizens. It is clear that the reform of the system will be blocked by the best efforts of those who profit from the current system. It now seems clear that nothing can be done until conditions get much worse. It may take a major economic and social disruption on the scale of the great depression of the 1930s to get most people to understand how badly they have been represented and to demand the major reforms that we need.
Possibly, a new third party will arise from the anger of the exploited majority and sweep most current officeholders out of office. Then we could get a new political majority that is not yet bought and paid for. There would then be an opportunity to make fundamental changes in the electoral system and to limit the uncontrolled power of corporations.
A necessary first step to clean up the system and restore political representation to ordinary citizens is to completely eliminate the need for raising money in elections. This is not easy, but it can be done. The key is to get the necessary exposure without the necessity of big money. It would also be good to limit the time devoted to the campaigns, perhaps two months for a presidential election and one month for all others.
All election related ads and debates should be carried on TV and radio without charge as a condition of the broadcast license. Paid political ads should be outlawed. The so-called "issue ads" placed to influence public opinion for the benefit of a particular candidate or party must also be banned during election periods
Obviously, airtime must be allocated in a fair and reasonable way. Candidates should qualify for minimal basic airtime simply by meeting the signature qualification for listing on the ballot. This would be a low fixed percentage of those who would be eligible to vote in that election. In order to avoid having the air time dominated by the many marginal candidates yet still permit them to be heard, it will be necessary to have unequal shares of air time. Here is one suggestion. The major parties should each start by sharing about 50% of the total time. The remaining airtime would be divided among the minor party candidates. Each week the airtime would be adjusted proportionally based on the preceding week's impartial polling results plus a basic allowance. In this way, a minor party candidate whose message resonates with the voters will be able to increase his or her air time each week and will have at least a fighting chance of beating a major party candidate.
In addition to the broadcasts, a taxpayer financed mailing containing statements from each candidate should be sent at least weekly during each election cycle. In these mailings each candidate will be free to comment on the positions and records of the other candidates as well as explaining his or her own position. This will result in a kind of running debate in print that everyone has access to. Each candidate can have equal space in this mailing, as the limits of airtime do not apply. The final mailing, arriving just before the election, should be devoted to candidates' final statements. At this point attacks on the opposing candidates and new charges should not be allowed because the other candidates will not be able to respond to them before the election.
The content of all of this material should be screened by a nonpartisan committee composed of nominees from membership supported watchdog groups of all political stripes such as the League of Women Voters, Cato Institute, Heritage Foundation, and Common Cause. If a candidate's material contains false or unverifiable statements then the screening committee will include a commentary pointing out the problem statements and include it following the candidate's material before publishing or broadcast. This should help to keep all the candidates honest. Censorship of the statements would be undesirable and possibly unconstitutional, but the constitution does not guarantee anyone's right to lie without being exposed.
It would be difficult to completely eliminate advocacy for particular parties or candidates outside of the formal structure of the campaign as outlined above. First amendment considerations preclude banning such things as print advertisements by individuals. Controlling advertising by corporations is a problem due to the fact that corporations are now considered to have the rights of actual people. That right is not in the constitution, and can be changed, but, given the present power of corporations, that will not happen anytime soon (with our current crop of politicians).
People should recognize that the credibility of such advertising is suspect compared to the fair treatment given to the candidates and their positions within the boundaries of the regular campaign. Since the broadcast media are owned by the people and are, or were until recently, required to be operated in the public interest, political broadcast advertising outside of the free airtime can be banned.
An important reform would be to get rid of the Electoral College system and adopt direct popular elections. Unfortunately this system is in the constitution, and, despite its dysfunctional nature, the states that benefit from it will do their best to keep it. A popular vote on it would probably get rid of it but that seems unlikely.
Another improvement would be to adopt the system used by several other democracies and have the voters rank the candidates. If there is no top rated candidate with a majority of the vote then the candidate with the lowest total vote is eliminated and the ballots recounted. This process continues until someone has a majority. This eliminates the spoiler effect of minor party candidates and the consequent reluctance to vote for them.
The result of these reforms will be the election of a candidate who is not indebted to big money contributors. The cost of running elections in this way would certainly be a trivial amount compared to the cost of even a few of the corrupt legislative favors that the large contributors now receive as the reward for the "election help" that they paid for.
The integrity of the election process must be insured by having voter verified paper trails for all voting and by having the process run by non-partisan election boards composed of citizens interested in keeping the process fair.
Election reform is an extremely important problem in America today. The importance of money in politics has crippled democracy and has resulted in a government by and for the wealthy and powerful.
Bill Isecke
Sunday, January 06, 2008
Killing Mosquitos and other dangerous insects.
By William Isecke
The control of mosquitoes, which has always been a major problem in tropical areas of the world, has now become a serious public health issue in the USA.
With the spread of West Nile Encephalitis to temperate areas of the world, the USA has become vulnerable to this disease. The public health response so far has been to spray large areas with insecticides. The spraying however, can only be a short term solution. Besides the well known problem of the insects developing a tolerance for the insecticides there are other disadvantages of this approach. Insecticides are poisons and they affect other species besides the target species. They kill other beneficial insects and wildlife including the natural predators of the pest species. The health effects on humans are not completely known and may be significant. Since poisons are not safe or effective, another method is needed.
The familiar backyard bug zappers typically use light to attract insects. They kill many insects, many of which are beneficial. Unfortunately, they kill few mosquitoes because these insects are not attracted to them.
A better approach to pest control is to directly target the troublesome species. In the case of mosquitoes, the female must find a blood meal from an animal in order to get the protein necessary for development of her eggs. She locates the animal host by following the plume of heat, carbon dioxide, and other chemicals that the animal emits.
There are commercial devices to trap mosquitoes that take advantage of this behavior. One of them is called the Mosquito Magnet.( http://www.mosquitomagnet.com/). This uses propane and Octenol to provide the heat, carbon dioxide, and chemical plume to attract the mosquitoes which are then sucked into the device, killed, and collected in a bag. This device is advertised as being capable of eliminating the mosquitoes on one acre of land. However, it costs about $1400 and requires a 20 pound tank of propane every three weeks. There is also a model which costs $ 700 but only covers one half acre. It still uses the same amount of propane. This fuel requirement and the high cost limit its applicability. There is another similar device called the Dragonfly (http://www.mosquitosolutions.com/) this costs about $650 and uses an electrified grid to kill the mosquitoes. This device uses about 40 watts of electricity and must be plugged in to operate.
A stand-alone electrified grid that would kill any insect that came in contact with it may be a better solution. The design of this insect killing screen would differ significantly from current designs for electrified bug killers. It would not be desirable to use the same kind of power supply as is used in the common bug zapper because of the danger of shock and because the constant presence of high voltage generates ozone and ionizes the air. This causes a constant power drain which makes it dependant on plug in power. We can use low power and still have sufficient high voltage to kill insects if the high voltage is only generated when an insect is present. This can be done by energizing the grid with a voltage that is not high enough to consume constant power but is high enough so that when an insect contacts the grid a detectable current flows. This current is then used to trigger a high voltage pulse which kills the insect. The power necessary to operate this grid should be low enough to use battery power combined with solar cells
If the high voltage pulse is also high frequency then the grid can be safe for animals because the resulting skin effect prevents the current from penetrating below the skin. An animal will feel a slight burn but no shock. The heating effect of the pulse would be sufficient to kill insects because their small mass would result in a temperature increase that would be lethal. Even if the energy of the pulse is quite small, the insect’s legs or whatever part is in contact with the grid would be destroyed thus permanently crippling the insect and removing it as a threat. Another approach is to use only enough energy to temporarily stun the insect so that it will fall into a trap from which it cannot escape
The simplest way to use the grid is to intercept the mosquitoes that are seeking us. It is necessary to insure that as the insects attempt to get to us, they encounter the electrified screen first. For example, the electrified screen could replace a normal mosquito screen in a house or animal pen. If the screen is covering the opening where air that is attractive to mosquitoes is leaving the enclosure, then mosquitoes that attempt to enter would be killed. It may be that in urban or suburban areas, most of the mosquitoes that bite people outdoors have previously attempted to enter a dwelling and been stopped by a screen. If that screen had been electrified, those mosquitoes would be dead and not able to bite. A complete stand-alone trap that is designed to kill these insects can be built by using one or more chemical attractants inside an electrified grid enclosure
Of course, mosquitoes are not the only insects that are dangerous pests. Tsetse flies, bot flies, black flies, sand flies and many others can also be controlled in this way. The trap may also be used to protect cows and other livestock from the many kinds of flies that prey on them. Agricultural pests may be controlled in this way also. Perhaps the traps could be baited with pheremones for this purpose.
Another application is to use insects as a food source. Many insects are attracted by dead animals and these insects are often quite large. For example, an insect trap baited with a fish head and hung over a fish pond will provide a constant source of flies as fish food. The same thing can be done over a chicken pen.
There are several conditions which must be met for a device such as this to be successful. One is that it must be low cost. Another is that it must be low energy so that it can be used wherever the insects are found. In addition, it must be effective; that is it must have a significant effect on the problems caused by the insects. I believe that this device can be made to meet all of these conditions.
Alternative approaches
In tropical areas, bed nets have been used with some success to control malaria. The bed nets are made of fabric impregnated with insecticide, usually Pyrethrin. These nets must be re impregnated after about 6 months and they only kill the mosquitoes if they remain on the net for a long time (approximately five minutes). The nets do have the advantages of low cost and easy set up. Probably the biggest long term problem with the nets is the fact that the mosquitoes will develop resistance to the insecticide, typically within a few years.
It may be possible to use treated nets to replace window screens. This would kill mosquitoes that are attempting to gain entry to an inhabited dwelling instead of simply keeping them out if they remain on the net long enough to absorb sufficient insecticide. This may have the same result as using the electrified grids described above. Since mosquitoes typically do not travel very far, in areas such as suburbs and summer camps this technique may be sufficient to extinguish the local population of mosquitoes. In other areas, a combination of impregnated nets and electronic traps may be necessary to control mosquitoes
The long term safety and efficacy of the insecticide used to impregnate the nets must be established. We can anticipate that the mosquito population will develop resistance to whatever insecticide is used and its effectiveness will diminish over time.
The electrified grid has the advantage that it kills any insect that comes in contact with it, however briefly, and there is no possibility of insects evolving resistance to it. In addition, the method used by mosquitoes to locate their prey is fixed and it seems that it would be very difficult to evolve a new method that would allow the mosquito to find animal hosts and still avoid the electronic traps. Even if a preference evolved for a different combination of the chemical and other cues that animals emit, it will be a relatively simple job to modify the bait so that mosquitoes will continue to be attracted and killed.
The disadvantages of the electrified grid are cost, complexity, and the delicacy of the wire grid. It will probably be necessary to protect the grid by putting a heavy large mesh netting in front of it to protect against impacts by birds or bats.
It does not seem possible to completely eliminate mosquitoes and other blood seeking insects although the idea is tempting. I don't know what the ecological consequences of that would be, but I think that many people would be willing to find out. If these insects have any beneficial function it may be to make large areas of the world uninhabitable for people and thus protect the other life forms there from people. Of course, mosquitoes prey on any animal that they can reach which means that people are kept away but the animals must still live with the mosquitoes.
It seems that the age-old battle between men and mosquitoes will go on but we may gain at least some relief. As Oscar Wilde said "The goal of science is to build better mousetraps. The goal of nature is to build better mice." Maybe we can shift the balance a little bit toward science.
There are many questions remaining to be answered:
Do large numbers of mosquitoes attempt to enter occupied houses and come into contact with screens?
Can a stand alone trap, baited with Octenol and Lactic Acid kill significant numbers of mosquitoes?
Is it necessary to use heat and carbon dioxide in addition?
Can the power required be low enough to permit the use of solar cells and rechargeable batteries?
How can the other types of insects that prey on animals be attracted?
By William Isecke
The control of mosquitoes, which has always been a major problem in tropical areas of the world, has now become a serious public health issue in the USA.
With the spread of West Nile Encephalitis to temperate areas of the world, the USA has become vulnerable to this disease. The public health response so far has been to spray large areas with insecticides. The spraying however, can only be a short term solution. Besides the well known problem of the insects developing a tolerance for the insecticides there are other disadvantages of this approach. Insecticides are poisons and they affect other species besides the target species. They kill other beneficial insects and wildlife including the natural predators of the pest species. The health effects on humans are not completely known and may be significant. Since poisons are not safe or effective, another method is needed.
The familiar backyard bug zappers typically use light to attract insects. They kill many insects, many of which are beneficial. Unfortunately, they kill few mosquitoes because these insects are not attracted to them.
A better approach to pest control is to directly target the troublesome species. In the case of mosquitoes, the female must find a blood meal from an animal in order to get the protein necessary for development of her eggs. She locates the animal host by following the plume of heat, carbon dioxide, and other chemicals that the animal emits.
There are commercial devices to trap mosquitoes that take advantage of this behavior. One of them is called the Mosquito Magnet.( http://www.mosquitomagnet.com/). This uses propane and Octenol to provide the heat, carbon dioxide, and chemical plume to attract the mosquitoes which are then sucked into the device, killed, and collected in a bag. This device is advertised as being capable of eliminating the mosquitoes on one acre of land. However, it costs about $1400 and requires a 20 pound tank of propane every three weeks. There is also a model which costs $ 700 but only covers one half acre. It still uses the same amount of propane. This fuel requirement and the high cost limit its applicability. There is another similar device called the Dragonfly (http://www.mosquitosolutions.com/) this costs about $650 and uses an electrified grid to kill the mosquitoes. This device uses about 40 watts of electricity and must be plugged in to operate.
A stand-alone electrified grid that would kill any insect that came in contact with it may be a better solution. The design of this insect killing screen would differ significantly from current designs for electrified bug killers. It would not be desirable to use the same kind of power supply as is used in the common bug zapper because of the danger of shock and because the constant presence of high voltage generates ozone and ionizes the air. This causes a constant power drain which makes it dependant on plug in power. We can use low power and still have sufficient high voltage to kill insects if the high voltage is only generated when an insect is present. This can be done by energizing the grid with a voltage that is not high enough to consume constant power but is high enough so that when an insect contacts the grid a detectable current flows. This current is then used to trigger a high voltage pulse which kills the insect. The power necessary to operate this grid should be low enough to use battery power combined with solar cells
If the high voltage pulse is also high frequency then the grid can be safe for animals because the resulting skin effect prevents the current from penetrating below the skin. An animal will feel a slight burn but no shock. The heating effect of the pulse would be sufficient to kill insects because their small mass would result in a temperature increase that would be lethal. Even if the energy of the pulse is quite small, the insect’s legs or whatever part is in contact with the grid would be destroyed thus permanently crippling the insect and removing it as a threat. Another approach is to use only enough energy to temporarily stun the insect so that it will fall into a trap from which it cannot escape
The simplest way to use the grid is to intercept the mosquitoes that are seeking us. It is necessary to insure that as the insects attempt to get to us, they encounter the electrified screen first. For example, the electrified screen could replace a normal mosquito screen in a house or animal pen. If the screen is covering the opening where air that is attractive to mosquitoes is leaving the enclosure, then mosquitoes that attempt to enter would be killed. It may be that in urban or suburban areas, most of the mosquitoes that bite people outdoors have previously attempted to enter a dwelling and been stopped by a screen. If that screen had been electrified, those mosquitoes would be dead and not able to bite. A complete stand-alone trap that is designed to kill these insects can be built by using one or more chemical attractants inside an electrified grid enclosure
Of course, mosquitoes are not the only insects that are dangerous pests. Tsetse flies, bot flies, black flies, sand flies and many others can also be controlled in this way. The trap may also be used to protect cows and other livestock from the many kinds of flies that prey on them. Agricultural pests may be controlled in this way also. Perhaps the traps could be baited with pheremones for this purpose.
Another application is to use insects as a food source. Many insects are attracted by dead animals and these insects are often quite large. For example, an insect trap baited with a fish head and hung over a fish pond will provide a constant source of flies as fish food. The same thing can be done over a chicken pen.
There are several conditions which must be met for a device such as this to be successful. One is that it must be low cost. Another is that it must be low energy so that it can be used wherever the insects are found. In addition, it must be effective; that is it must have a significant effect on the problems caused by the insects. I believe that this device can be made to meet all of these conditions.
Alternative approaches
In tropical areas, bed nets have been used with some success to control malaria. The bed nets are made of fabric impregnated with insecticide, usually Pyrethrin. These nets must be re impregnated after about 6 months and they only kill the mosquitoes if they remain on the net for a long time (approximately five minutes). The nets do have the advantages of low cost and easy set up. Probably the biggest long term problem with the nets is the fact that the mosquitoes will develop resistance to the insecticide, typically within a few years.
It may be possible to use treated nets to replace window screens. This would kill mosquitoes that are attempting to gain entry to an inhabited dwelling instead of simply keeping them out if they remain on the net long enough to absorb sufficient insecticide. This may have the same result as using the electrified grids described above. Since mosquitoes typically do not travel very far, in areas such as suburbs and summer camps this technique may be sufficient to extinguish the local population of mosquitoes. In other areas, a combination of impregnated nets and electronic traps may be necessary to control mosquitoes
The long term safety and efficacy of the insecticide used to impregnate the nets must be established. We can anticipate that the mosquito population will develop resistance to whatever insecticide is used and its effectiveness will diminish over time.
The electrified grid has the advantage that it kills any insect that comes in contact with it, however briefly, and there is no possibility of insects evolving resistance to it. In addition, the method used by mosquitoes to locate their prey is fixed and it seems that it would be very difficult to evolve a new method that would allow the mosquito to find animal hosts and still avoid the electronic traps. Even if a preference evolved for a different combination of the chemical and other cues that animals emit, it will be a relatively simple job to modify the bait so that mosquitoes will continue to be attracted and killed.
The disadvantages of the electrified grid are cost, complexity, and the delicacy of the wire grid. It will probably be necessary to protect the grid by putting a heavy large mesh netting in front of it to protect against impacts by birds or bats.
It does not seem possible to completely eliminate mosquitoes and other blood seeking insects although the idea is tempting. I don't know what the ecological consequences of that would be, but I think that many people would be willing to find out. If these insects have any beneficial function it may be to make large areas of the world uninhabitable for people and thus protect the other life forms there from people. Of course, mosquitoes prey on any animal that they can reach which means that people are kept away but the animals must still live with the mosquitoes.
It seems that the age-old battle between men and mosquitoes will go on but we may gain at least some relief. As Oscar Wilde said "The goal of science is to build better mousetraps. The goal of nature is to build better mice." Maybe we can shift the balance a little bit toward science.
There are many questions remaining to be answered:
Do large numbers of mosquitoes attempt to enter occupied houses and come into contact with screens?
Can a stand alone trap, baited with Octenol and Lactic Acid kill significant numbers of mosquitoes?
Is it necessary to use heat and carbon dioxide in addition?
Can the power required be low enough to permit the use of solar cells and rechargeable batteries?
How can the other types of insects that prey on animals be attracted?
Wednesday, December 26, 2007
Sinking of the MS Explorer near Antarctica
Since I am scheduled to travel to Antarctica on a ship similar to the Explorer, I was very interested in the accident that caused the loss of this ship. After reading everything I could find about the Explorer, I thought that the ship may have been lost because the crew did not know of a technique that could have saved her.
I wonder why the Explorer was not saved by the old trick of passing a sail under the ship and pulling it up against the outside of the hole in the hull. The procedure would be to tie a long rope to each corner of a large square tarp or sail, then , starting from the bow, let the sail sink below the hull and then pull it back using two ropes on each side of the ship until the sail was centered outside of the hole. Then pull the sail tightly against the hull with the ropes. This should prevent any more water from entering the ship because the water pressure would cause a tight seal against the hole.
This procedure was described in one of Patrick Obrien’s books in the Aubury / Maturin series about the British navy in the early 19th century. The Explorer must have had enough rope and tarps to do the job but apparently nobody tried - or at least I could not find it in any published accounts of the accident that I found.
I wonder why the Explorer was not saved by the old trick of passing a sail under the ship and pulling it up against the outside of the hole in the hull. The procedure would be to tie a long rope to each corner of a large square tarp or sail, then , starting from the bow, let the sail sink below the hull and then pull it back using two ropes on each side of the ship until the sail was centered outside of the hole. Then pull the sail tightly against the hull with the ropes. This should prevent any more water from entering the ship because the water pressure would cause a tight seal against the hole.
This procedure was described in one of Patrick Obrien’s books in the Aubury / Maturin series about the British navy in the early 19th century. The Explorer must have had enough rope and tarps to do the job but apparently nobody tried - or at least I could not find it in any published accounts of the accident that I found.
Sunday, December 05, 2004
NEW EDUCATIONAL WEBSITE
The website is http:www.harrietisecke.com
Harriet is my wife and she has become an expert in many educational topics.
She does professional development for teachers on:
Preschool brain development
Early literacy techniques used in New Zealand
Techniques for teaching reading and mathematics
How to teach writing skills
Education by design
Many other topics in K-12 education
She also has written six children's picture books published by Childcrafteducation.com
Go to her site for more information and contact information
http:www.harrietisecke.com
Bill Isecke
Harriet is my wife and she has become an expert in many educational topics.
She does professional development for teachers on:
Preschool brain development
Early literacy techniques used in New Zealand
Techniques for teaching reading and mathematics
How to teach writing skills
Education by design
Many other topics in K-12 education
She also has written six children's picture books published by Childcrafteducation.com
Go to her site for more information and contact information
http:www.harrietisecke.com
Bill Isecke
Sunday, November 07, 2004
waiting for disaster
The recent attack on the World Trade Center and the Pentagon leads to the question of why there were no effective measures in place to protect against it. The type of attack was not novel. In fact there have been popular fictionalized accounts of the use of airliners as weapons. There were many warnings that a terrorist attack could be expected very soon. There had also been many well-publicized tests of the airlines' security systems which showed that they were easily overcome and weapons could be carried onto aircraft by passengers. There was also ample warning that terrorists would not hesitate to engage in suicide attacks. These attacks are common in the Middle East and have even been used against US military targets there. Now, in the clear light of hindsight, it is obvious that the improvements in airline security are necessary.
But why was it necessary to wait for disaster?
Mankind seems to be nearly incapable of taking steps to avoid easily anticipated disasters. If we consider a few types of disasters and recall the history of attempts to avoid them the problem is clear.
Having fire escapes in buildings, adequate lifeboats on ships, dead man controls on trains, and many other disaster avoidance requirements only came into use in response to major disasters. This was true despite the fact that these disasters are very easy to anticipate. Why was it necessary to experience a tragic loss of life before taking precautions that seem like simple common sense?
Perhaps the cost of the precaution seems more important than the potential disaster, which might not happen.
Even after new laws or building codes have been adopted, there is still widespread evasion often with official complicity. For example, in Florida, hurricane Andrew revealed that much of the housing that was destroyed did not have reinforcements required by the building codes that were in force when the houses were constructed. The fact that the houses were inspected and passed indicates official complicity or at least incompetence.
There is also a common tendency to design structures in a way that minimizes cost but does not prevent failure due to circumstances that are considered unlikely. The principle that the designers do not observe is that if the consequence of failure cannot be tolerated then, even if the probability is low, the possibility of such failure must be designed out.
The Titanic sank because its designer thought that only a small number of compartments could ever flood at the same time and therefore the internal bulkheads, which separated the compartments, did not have to extend all the way to the deck.
The World Trade Center towers collapsed because the supports that attached the floors to the vertical beams were strong enough to support the weight of the floor and it's contents but when the supports of one floor failed due to fire, the floor below was not able to withstand the force of the floor above dropping onto it. The floor beams could have been strong enough to support any number of fallen floors since the vertical columns that they attached to were strong enough to support all the weight of the building above them.
The designers of the World Trade Center either did not anticipate this failure mode or thought that it could not happen. Perhaps they thought that the sprinkler system would prevent the failure of the floor beams by controlling any possible fire. There were narrow stairways, not enough of them, and they were not sufficiently protected from smoke.
Of course now, after the disaster, we may hope that any future tall buildings will be designed to eliminate this particular failure mode.
There are probably now many similar disasters waiting to happen. Let's hope that we have learned enough to avoid at least some of them.
But why was it necessary to wait for disaster?
Mankind seems to be nearly incapable of taking steps to avoid easily anticipated disasters. If we consider a few types of disasters and recall the history of attempts to avoid them the problem is clear.
Having fire escapes in buildings, adequate lifeboats on ships, dead man controls on trains, and many other disaster avoidance requirements only came into use in response to major disasters. This was true despite the fact that these disasters are very easy to anticipate. Why was it necessary to experience a tragic loss of life before taking precautions that seem like simple common sense?
Perhaps the cost of the precaution seems more important than the potential disaster, which might not happen.
Even after new laws or building codes have been adopted, there is still widespread evasion often with official complicity. For example, in Florida, hurricane Andrew revealed that much of the housing that was destroyed did not have reinforcements required by the building codes that were in force when the houses were constructed. The fact that the houses were inspected and passed indicates official complicity or at least incompetence.
There is also a common tendency to design structures in a way that minimizes cost but does not prevent failure due to circumstances that are considered unlikely. The principle that the designers do not observe is that if the consequence of failure cannot be tolerated then, even if the probability is low, the possibility of such failure must be designed out.
The Titanic sank because its designer thought that only a small number of compartments could ever flood at the same time and therefore the internal bulkheads, which separated the compartments, did not have to extend all the way to the deck.
The World Trade Center towers collapsed because the supports that attached the floors to the vertical beams were strong enough to support the weight of the floor and it's contents but when the supports of one floor failed due to fire, the floor below was not able to withstand the force of the floor above dropping onto it. The floor beams could have been strong enough to support any number of fallen floors since the vertical columns that they attached to were strong enough to support all the weight of the building above them.
The designers of the World Trade Center either did not anticipate this failure mode or thought that it could not happen. Perhaps they thought that the sprinkler system would prevent the failure of the floor beams by controlling any possible fire. There were narrow stairways, not enough of them, and they were not sufficiently protected from smoke.
Of course now, after the disaster, we may hope that any future tall buildings will be designed to eliminate this particular failure mode.
There are probably now many similar disasters waiting to happen. Let's hope that we have learned enough to avoid at least some of them.
Monday, August 02, 2004
Power Tower Proposal
Letters to the Editor, New Scientist
Power Tower Extras
(New Scientist, July 31, 2004)
The planned Power Tower in the Australian outback(www.enviromission.com.au/intro.htm) can produce more than electrical power. It can also be used to provide much needed fresh water. In the outback area the ground water is plentiful but is too salty for drinking or for irrigation. This salt water can be evaporated in troughs under the solar collection surface. In this area the air will be very hot and able to evaporate all of the water leaving behind only solid salts. The value of the salts can be increased by using long troughs arranged like the spokes of a wheel for evaporation. This will result in individual salts crystallizing out in different areas of the troughs depending on their solubility. The salts can be collected separately and sold for high prices because they will have high purity. A large amount of water can be treated since hot air can hold much more moisture than cold air. As the hot humid air rises up the stack, it cools by expansion and some of the water condenses out and is captured inside the stack using drip nets.
The addition of the desalination component to the project will require a larger solar collector area but will also increase the amount of energy that can be produced. This is because the moist air rising in the stack will not cool as fast as dry air would since the water condensing out will release heat. This is the energy that drives hurricanes and should substantially increase the output of the turbines.
As the air leaves the stack at the top it will still have considerable moisture in it. This moisture will fall as rain downwind of the stack as the plume of hot moist air continues to rise. Thus a large area around the stack will become productive farmland. Some of the fresh water collected in the stack can be used for growing vegetables under the periphery of the solar collectors. This water will be recycled back into the system.
Two additional benefits of this addition are that the water filled troughs will provide heat storage and, in the long term, the salinity of the aquifer will be reduced since salt is constantly being removed.
William Isecke
541 Queen Anne Road
Teaneck, NJ 07666, US
201 836 8403
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