Witch hazel blossoms on February 5! Not here, but down in Longwood Gardens in Kennett Square, Pennsylvania: a public botanical and pleasure garden around which I had some time to wander before giving a lecture. One little grove was particularly fragrant and comely, with a few witch hazel shrubs with yellow blossoms, some with bright orange blossoms and some with brownish-orange blossoms.
February 5 is early for witch hazel even down there, reflecting what has been the mildest winter in memory. While many people prefer mild winters, this weather worries a lot of gardeners. Are plants going to become “soft”? Is possible cold weather in the weeks ahead going to do them in?
Call me a Pollyanna, but I have a lot of faith in Mother Nature (or, put another way, natural systems) to adapt and protect against calamities. Not that everything will necessarily keep chugging along the way that we humans like it, but that forests will remain forests – perhaps with some changes in species – and that garden plants should, in general, survive.
A few odd things are going on this winter here in the Northeast and over much of the rest of the country. First are the mild temperatures. People worry that plants might begin to grow too soon. But today’s and tomorrow’s temperatures aren’t the only things that shake plants awake this time of year. Day length also comes into play; and, no matter what the winter is like, day length is the same on any given date from year to year.
Temperatures over the past weeks and months also come into play: Plants won’t begin growth until they’ve experienced a certain number of hours of cool (not cold) temperatures, signaling for them that winter is over and it’s safe to grow. Some winters, those hours begin to accumulate in autumn and then finish accumulating in late winter, when temperatures turn cool (not frigid) again. In the South – and perhaps this far north, this winter at least – those hours could have accumulated sufficiently through winter to cause an early awakening of plants.
The first sign that many trees and shrubs show of awakening is the appearance of their flowers. These early blossoms could, in fact, succumb to subsequent cold weather. That cold could nip off developing fruits, snuffing out this year’s crop. Or that cold weather could turn, say, an early tulip blossom from a handsome red cup to a wet dishrag on a stalk. In either case, the plants themselves, except for the blossoms and fruits, should not be harmed.
The second odd thing about this winter is the lack of snow cover. Snow reflects light and heat from the winter Sun. Evergreens don’t like this at a time when their roots are cold and not especially active. The result is scorched leaves. Bark also can scorch – except that this time it’s called scalding – when the winter Sun heats up dark bark by day, and then bark temperatures plummet as the Sun drops below the horizon.
On the plus side, snow is a great insulator. It helps modulate soil temperatures to minimize alternate freezing and thawing, which can heave plants up and out of the soil. Heaving is especially a problem with young or new plants, as yet hardly rooted. That insulating white blanket also lessens roots’ exposure to cold. Without snow, less cold-hardy plants (and we gardeners are always pushing the limits) might show more winter damage.
Then again, snow isn’t the only insulator. Any good gardener mulches plants to provide nutrients, to conserve water, to build up humus and to feed beneficial soil life. I’m banking on those layers of wood chips, leaves, straw and other organic materials that I spread through autumn to protect my roots – plants’ roots, that is.
2012年2月20日星期一
2012年2月19日星期日
Holly Springs students gain hands-on education
Despite cold temperatures and the threat of wintery weather, students at Holly Springs Elementary School kept warm as they learned about heat and energy Tuesday with the help of Georgia Power.
The program, called “Learning is Power: Energy Education in the Classroom,” coincides with Common Core Georgia Performance Standards in science, mathematics and language arts with a focus on science, technology, engineering and mathematics subjects. The program, including experiment materials, is provided to schools by Georgia Power at no cost.
Third- and fifth-grade students experienced hands-on activities led by Georgia Power Education Coordinator Deborah Pendergrass during the session. The first activity required the children to rub their hands together to create friction.
“Energy is doing work and creating heat,” Pendergrass said to Bridget Barker’s third-grade students. She then instructed them to raise their hands up — making everyone feel the cold air and how heat transfers.
Students then talked about places in their homes that the air temperature outside could affect the air temperature inside. “I picked the ceiling because I feel more air when I go up to my attic,” said Austin Morris, son of Greg and Kylee Morris of Woodstock.
Other experiments included measuring the temperature of hot water in one cup with a lid and another cup without a lid with a Celsius thermometer. Later, students measured which cup of water lost the most heat.
“The lid served as an insulator,” Pendergrass said.
The students also got to participate in an “ice race,” where they hypothesized whether a conductor or an insulator would melt the ice first. “The conductor expands the heat, gets hotter and melts the ice quicker,” Blake Cantrell, grandson of Melinda Duncan of Canton, said.
At the end of the experiment, students received bookmarks with energy efficient tips to take home with them. Principal Dr. Dianne Steinbeck said she could not emphasize how valuable the hands-on scientific experiments were for Holly Springs students. She said since the school was selected to be a STEM academy for fall 2012, projects like this are only a preview of what is to come.
“We are converting space to become our new science lab,” Steinbeck said. “It’s all about opportunity, and the fact that Georgia Power is doing this at no cost is tremendous.”
The program, called “Learning is Power: Energy Education in the Classroom,” coincides with Common Core Georgia Performance Standards in science, mathematics and language arts with a focus on science, technology, engineering and mathematics subjects. The program, including experiment materials, is provided to schools by Georgia Power at no cost.
Third- and fifth-grade students experienced hands-on activities led by Georgia Power Education Coordinator Deborah Pendergrass during the session. The first activity required the children to rub their hands together to create friction.
“Energy is doing work and creating heat,” Pendergrass said to Bridget Barker’s third-grade students. She then instructed them to raise their hands up — making everyone feel the cold air and how heat transfers.
Students then talked about places in their homes that the air temperature outside could affect the air temperature inside. “I picked the ceiling because I feel more air when I go up to my attic,” said Austin Morris, son of Greg and Kylee Morris of Woodstock.
Other experiments included measuring the temperature of hot water in one cup with a lid and another cup without a lid with a Celsius thermometer. Later, students measured which cup of water lost the most heat.
“The lid served as an insulator,” Pendergrass said.
The students also got to participate in an “ice race,” where they hypothesized whether a conductor or an insulator would melt the ice first. “The conductor expands the heat, gets hotter and melts the ice quicker,” Blake Cantrell, grandson of Melinda Duncan of Canton, said.
At the end of the experiment, students received bookmarks with energy efficient tips to take home with them. Principal Dr. Dianne Steinbeck said she could not emphasize how valuable the hands-on scientific experiments were for Holly Springs students. She said since the school was selected to be a STEM academy for fall 2012, projects like this are only a preview of what is to come.
“We are converting space to become our new science lab,” Steinbeck said. “It’s all about opportunity, and the fact that Georgia Power is doing this at no cost is tremendous.”
2012年2月16日星期四
Bilayer Graphene Functions As Insulator
Many researchers are eying graphene for its potential use in electronics applications. Because single-layer graphene (SLG) is gapless, however, they keep finding that it cannot be completely turned off. Regardless of the number of electrons on SLG, it always remains both metallic and a conductor. Yet a research team led by physicists at the University of California, Riverside has now found that the intrinsic energy gap in bilayer graphene (BLG) grows with an increasing magnetic field.
Generally, the size of a material’s energy gap determines whether it is a conductor (no gap), semiconductor (small gap), or insulator (large gap). When the number of electrons on the BLG sheet is close to 0, the researchers have found that the material becomes insulating. This finding suggests that graphene could eventually be used as a semiconductor substrate, as engineers working on digital applications need to turn their devices on and off .
Because of graphene’s planar and chicken-wire-like structure, sheets of it lend themselves well to stacking. BLG is formed when two graphene sheets are stacked in a special manner. Like graphene, BLG has high electron conductivity. This high current-carrying capacity results from the extremely high velocities that electrons can acquire in a graphene sheet.
According to Chun Ning (Jeanie) Lau, an Associate Professor of Physics and Astronomy, BLG becomes insulating because its electrons spontaneously organize themselves when their number is small. A typical conductor has a huge number of electrons, Lau explains, which move around randomly—rather like a party with 10,000 guests with no assigned seats at dining tables. If the party only has four guests, however, the guests will have to interact with each other and sit down at a table. Similarly, when BLG has only a few electrons, the interactions cause the electrons to behave in an orderly manner.
In their research, which is detailed in the January 22 online edition of Nature Nanotechnology, the team also has measured the mass of a new type of massive quantum particle that can be found only inside BLG crystals. They were motivated by theoretical work, which anticipated that new particles would emerge from the electron sea of a BLG crystal. Despite the excitement over this initial research, the team notes that the energy bandgap of the graphene materials they have investigated so far is still too small for practical applications. Yet it does suggest a promising path in trilayer or even tetralayer graphene, which would most likely have larger energy gaps.
Generally, the size of a material’s energy gap determines whether it is a conductor (no gap), semiconductor (small gap), or insulator (large gap). When the number of electrons on the BLG sheet is close to 0, the researchers have found that the material becomes insulating. This finding suggests that graphene could eventually be used as a semiconductor substrate, as engineers working on digital applications need to turn their devices on and off .
Because of graphene’s planar and chicken-wire-like structure, sheets of it lend themselves well to stacking. BLG is formed when two graphene sheets are stacked in a special manner. Like graphene, BLG has high electron conductivity. This high current-carrying capacity results from the extremely high velocities that electrons can acquire in a graphene sheet.
According to Chun Ning (Jeanie) Lau, an Associate Professor of Physics and Astronomy, BLG becomes insulating because its electrons spontaneously organize themselves when their number is small. A typical conductor has a huge number of electrons, Lau explains, which move around randomly—rather like a party with 10,000 guests with no assigned seats at dining tables. If the party only has four guests, however, the guests will have to interact with each other and sit down at a table. Similarly, when BLG has only a few electrons, the interactions cause the electrons to behave in an orderly manner.
In their research, which is detailed in the January 22 online edition of Nature Nanotechnology, the team also has measured the mass of a new type of massive quantum particle that can be found only inside BLG crystals. They were motivated by theoretical work, which anticipated that new particles would emerge from the electron sea of a BLG crystal. Despite the excitement over this initial research, the team notes that the energy bandgap of the graphene materials they have investigated so far is still too small for practical applications. Yet it does suggest a promising path in trilayer or even tetralayer graphene, which would most likely have larger energy gaps.
2012年2月15日星期三
Nano-coating doubles rate of heat transfer
Pool boiling is the most common and familiar method of heating a container's contents, and is a remarkably efficient heat transfer method. The transfer of heat in this case is referred to as the "heat flux." There exists, however, a critical point at which a solid surface gets too hot and pool-boiling efficiency is lost.
"Delaying the critical flux could play an important role in advancing thermal management of electronics as well as improving the efficiency of a number of energy systems," says Bo Feng, Ph.D., the Georgia Tech researcher leading this project.
In boiling, bubbles carry away large amounts of heat from solid surfaces, but the bubbles also act as an insulator, preventing the liquid from rewetting the surface and thereby interrupting heat transfer. The alumina coating – only a few hundreds of atoms thick – has a high affinity to water and, as a result, facilitates the rapid rewetting of the solid surface.
"This is the primary reason for the enhancement of heat transfer," says Feng. An atomic layer deposition technique was used to control the thickness. By achieving such a thin coating, the additional layer of alumina did not appreciably increase thermal resistance, but it did increase the overall heat transfer.
"The potential contribution of this investigation lies in tailoring the wettability of surfaces at the nanometer scale, thereby greatly increasing the heat transfer during pool boiling," adds G.P. "Bud" Peterson, Ph.D., director of Georgia Tech's Two-Phase Heat Transfer Lab. "This is especially promising for applications where the implementation of nanotube or nanowire arrays are possible."
Nanotube and nanowire arrays are another effective way to enhance pool boiling heat transfer. Combining these two techniques – nanotube and/or nanowire arrays and nano-coating by atomic layer deposition – may increase pool-boiling efficiency even further.
"Delaying the critical flux could play an important role in advancing thermal management of electronics as well as improving the efficiency of a number of energy systems," says Bo Feng, Ph.D., the Georgia Tech researcher leading this project.
In boiling, bubbles carry away large amounts of heat from solid surfaces, but the bubbles also act as an insulator, preventing the liquid from rewetting the surface and thereby interrupting heat transfer. The alumina coating – only a few hundreds of atoms thick – has a high affinity to water and, as a result, facilitates the rapid rewetting of the solid surface.
"This is the primary reason for the enhancement of heat transfer," says Feng. An atomic layer deposition technique was used to control the thickness. By achieving such a thin coating, the additional layer of alumina did not appreciably increase thermal resistance, but it did increase the overall heat transfer.
"The potential contribution of this investigation lies in tailoring the wettability of surfaces at the nanometer scale, thereby greatly increasing the heat transfer during pool boiling," adds G.P. "Bud" Peterson, Ph.D., director of Georgia Tech's Two-Phase Heat Transfer Lab. "This is especially promising for applications where the implementation of nanotube or nanowire arrays are possible."
Nanotube and nanowire arrays are another effective way to enhance pool boiling heat transfer. Combining these two techniques – nanotube and/or nanowire arrays and nano-coating by atomic layer deposition – may increase pool-boiling efficiency even further.
2012年2月14日星期二
Microscopy explores nanowires' weakest link
Individual atoms can make or break electronic properties in one of the world's smallest known conductors - quantum nanowires. Microscopic analysis at the Department of Energy's Oak Ridge National Laboratory is delivering a rare glimpse into how the atomic structure of the conducting nanowires affects their electronic behaviour.
The ORNL team's microscopy confirmed that deliberately introduced defects, which are only the size of a single atom, could turn a conducting nanowire into an insulator by shutting down the path of electrons.
Led by ORNL's An-Ping Li, the research team used multiple-probe scanning tunneling microscopy to analyse nanowires made of a material called gadolinium silicide.
"This type of one-dimensional conductor is expected to be a fundamental component in all quantum electronic architectures," said Li, a research scientist at ORNL's Center for Nanophase Materials Science. "One advantage of GdSi2 nanowires is they are compatible with conventional silicon technology and are thus easier to implement in nanoelectronic devices."
The research, published in the American Chemical Society's Nano Letters, is the first correlated study that links electron movement to structural elements such as single point defects or impurities that are intentionally grown in the nanowires.
"When a conductor becomes so small, it will be very sensitive to atomic defects on the nanowire," Li said. "If the conductor or the wire is big, electrons can always find a way to go around. But with such a small nanowire, electrons have no way to escape. When you put only a few defects on this nanowire, you can cut off the conductance and can convert a conductor into an insulator."
Although single nanowires exhibited the metal-to-insulator transition, the ORNL team observed different behaviour in bundles of nanowires constructed of two, three or more wires separated by only a few angstroms.
"If you put bundles together, the interwire coupling generally has a stabilising effect on the structure which in turn leads to better conductance," Li said.
The team also used theoretical first principles calculations to confirm and explain its experimental findings. Coauthors on the paper are ORNL's Shengyong Qin, Tae-Hwan Kim and Arthur Baddorf; Yanning Zhang, Wenjie Ouyang and Ruqian Wu of the University of California, Irvine; Hanno Weitering of the University of Tennessee; and Chih-Kang Shih of the University of Texas at Austin.
The ORNL team's microscopy confirmed that deliberately introduced defects, which are only the size of a single atom, could turn a conducting nanowire into an insulator by shutting down the path of electrons.
Led by ORNL's An-Ping Li, the research team used multiple-probe scanning tunneling microscopy to analyse nanowires made of a material called gadolinium silicide.
"This type of one-dimensional conductor is expected to be a fundamental component in all quantum electronic architectures," said Li, a research scientist at ORNL's Center for Nanophase Materials Science. "One advantage of GdSi2 nanowires is they are compatible with conventional silicon technology and are thus easier to implement in nanoelectronic devices."
The research, published in the American Chemical Society's Nano Letters, is the first correlated study that links electron movement to structural elements such as single point defects or impurities that are intentionally grown in the nanowires.
"When a conductor becomes so small, it will be very sensitive to atomic defects on the nanowire," Li said. "If the conductor or the wire is big, electrons can always find a way to go around. But with such a small nanowire, electrons have no way to escape. When you put only a few defects on this nanowire, you can cut off the conductance and can convert a conductor into an insulator."
Although single nanowires exhibited the metal-to-insulator transition, the ORNL team observed different behaviour in bundles of nanowires constructed of two, three or more wires separated by only a few angstroms.
"If you put bundles together, the interwire coupling generally has a stabilising effect on the structure which in turn leads to better conductance," Li said.
The team also used theoretical first principles calculations to confirm and explain its experimental findings. Coauthors on the paper are ORNL's Shengyong Qin, Tae-Hwan Kim and Arthur Baddorf; Yanning Zhang, Wenjie Ouyang and Ruqian Wu of the University of California, Irvine; Hanno Weitering of the University of Tennessee; and Chih-Kang Shih of the University of Texas at Austin.
2012年2月13日星期一
Get the Real Dirt to Growing a Beautiful Green Lawn
Power Equipment Warehouse, a global supplier of power equipment and lawn care products wants your lawn to be healthy, beautiful and lush so you can enjoy it! Winter is still upon us, but now is the perfect time to prepare your lawn and garden.
Your lawn can be adversely affected by winter desiccation which commonly occurs in heavy, clay compacted soils. Desiccation occurs when snow remains atop the lawn for an extended period of time. Winter watering can minimize the damaging effects of dry conditions. Check the forecast and only water your lawn when the soil is unfrozen and the air temperature is above 40 degrees F. Do not water before a sudden temperature drop because this can permanently harm your plants and lawn. It is best to apply water at mid-day so it can gravitate into the soil before colder nighttime temperatures and potential freezing. Try to moisten the top 6 inches of soil for turf-grasses, and the top 12 inches for trees and shrubs. Do not use root feeders or other deep root watering devices in the winter. Water slowly so it soaks in and does not run off or freeze. If dry conditions persist, one or two careful irrigations per month may be needed.
Got the dirt on your dirt? Are you happy with the appearance of your lawn? How about your flower beds or vegetable garden? If you are not happy, have you ever considered having your soil tested? Most of us haven’t but let’s face it, happy plants grow in good soil and plants plagued by pests and disease do not. Most soil problems start with pH problems, or the acidity and alkalinity of the soil. Check with your local Cooperative Extension agent, (simply Google “Cooperative Extensions” in your State) and ask them to check the soil as well as the percentages of sand, silt and clay. It may take a year or two to get the levels where you want them. Lime is not an instant fix; it takes time for lime to combine with soil particles before improvement can be seen. January and February is the time to do this.
Do you plan to re-plant your lawn or patch some spots? Be sure to check the soil as advised above. Grass seed can be applied in March, or when the soil begins to warm (depending on your climate). Keep in mind there are many types of grass seed to choose from; quick germination, sun, shade and even play areas. Crabgrass control can be used until the end of April or when the soil temperatures reach 70 to 80 degrees. Weed killers need to be applied while the weeds are growing actively and can be applied until growth stops in the fall. Grub controls can be applied from May thru August, depending on the type of chemicals they contain. Remember to start grub control treatment from the foundation of your home outward because grubs infest flower beds as well as lawns. Grubs attract skunks too!
These turf management practices will keep your yard healthy and lush. Aeration is the process of mechanically removing cores of turf to improve the flow of air, water and nutrients in dense, compacted soil. Soil compaction occurs due to foot traffic and mowing. Compacted soil forces particles together thus reducing the area where roots can grow. Aeration relieves this and allows air, water and nutrients to reach the grass roots. Aeration should be performed at least once a year in the spring between March and May, or in the fall between August and November. Cool season grasses such as perennial Rye grass and Kentucky bluegrass benefit from fall aeration while warm season grasses such as Zoysia and Bermuda benefit most from spring or summer aeration. To prepare your yard for aeration, map out any obstructions such as sprinkler heads and drains. Water the area the night before to soften the soil and go over high traffic areas more than Water and apply fertilizer after aeration.
Thatch is a layer of accumulated roots, crowns and grass clipping that act as an insulator to keep soil temperatures low and retain moisture. A build up of thatch thicker than inch will prevent the exchange of water and nutrients in the soil. This decreases the turf’s ability to thrive and fight disease and dehydration. Dethatching, also known as combing or power raking, removes unwanted thatch. Dethatching is recommended to be done in early spring or late fall and can be done with flail blades, delta reel blades or spring tines. Be sure the blades on the dethatcher are not set too deeply.
Revive your tired, thin lawn by over seeding it. Rotating knives slice the turf and seeds are deposited into the slits. As the seeder moves forward, the soil covers the seeds and aids germination. We recommend over seeding in two applications with the second application made at a 45 degree angle to the first. You will notice a distinct pattern that will grow- in after the turf gets thicker. Water thoroughly as soon as over seeding is complete and continue to water lightly each day until the seeds germinate. Water regularly once the grass has sprouted to encourage deeper root growth.
Your lawn can be adversely affected by winter desiccation which commonly occurs in heavy, clay compacted soils. Desiccation occurs when snow remains atop the lawn for an extended period of time. Winter watering can minimize the damaging effects of dry conditions. Check the forecast and only water your lawn when the soil is unfrozen and the air temperature is above 40 degrees F. Do not water before a sudden temperature drop because this can permanently harm your plants and lawn. It is best to apply water at mid-day so it can gravitate into the soil before colder nighttime temperatures and potential freezing. Try to moisten the top 6 inches of soil for turf-grasses, and the top 12 inches for trees and shrubs. Do not use root feeders or other deep root watering devices in the winter. Water slowly so it soaks in and does not run off or freeze. If dry conditions persist, one or two careful irrigations per month may be needed.
Got the dirt on your dirt? Are you happy with the appearance of your lawn? How about your flower beds or vegetable garden? If you are not happy, have you ever considered having your soil tested? Most of us haven’t but let’s face it, happy plants grow in good soil and plants plagued by pests and disease do not. Most soil problems start with pH problems, or the acidity and alkalinity of the soil. Check with your local Cooperative Extension agent, (simply Google “Cooperative Extensions” in your State) and ask them to check the soil as well as the percentages of sand, silt and clay. It may take a year or two to get the levels where you want them. Lime is not an instant fix; it takes time for lime to combine with soil particles before improvement can be seen. January and February is the time to do this.
Do you plan to re-plant your lawn or patch some spots? Be sure to check the soil as advised above. Grass seed can be applied in March, or when the soil begins to warm (depending on your climate). Keep in mind there are many types of grass seed to choose from; quick germination, sun, shade and even play areas. Crabgrass control can be used until the end of April or when the soil temperatures reach 70 to 80 degrees. Weed killers need to be applied while the weeds are growing actively and can be applied until growth stops in the fall. Grub controls can be applied from May thru August, depending on the type of chemicals they contain. Remember to start grub control treatment from the foundation of your home outward because grubs infest flower beds as well as lawns. Grubs attract skunks too!
These turf management practices will keep your yard healthy and lush. Aeration is the process of mechanically removing cores of turf to improve the flow of air, water and nutrients in dense, compacted soil. Soil compaction occurs due to foot traffic and mowing. Compacted soil forces particles together thus reducing the area where roots can grow. Aeration relieves this and allows air, water and nutrients to reach the grass roots. Aeration should be performed at least once a year in the spring between March and May, or in the fall between August and November. Cool season grasses such as perennial Rye grass and Kentucky bluegrass benefit from fall aeration while warm season grasses such as Zoysia and Bermuda benefit most from spring or summer aeration. To prepare your yard for aeration, map out any obstructions such as sprinkler heads and drains. Water the area the night before to soften the soil and go over high traffic areas more than Water and apply fertilizer after aeration.
Thatch is a layer of accumulated roots, crowns and grass clipping that act as an insulator to keep soil temperatures low and retain moisture. A build up of thatch thicker than inch will prevent the exchange of water and nutrients in the soil. This decreases the turf’s ability to thrive and fight disease and dehydration. Dethatching, also known as combing or power raking, removes unwanted thatch. Dethatching is recommended to be done in early spring or late fall and can be done with flail blades, delta reel blades or spring tines. Be sure the blades on the dethatcher are not set too deeply.
Revive your tired, thin lawn by over seeding it. Rotating knives slice the turf and seeds are deposited into the slits. As the seeder moves forward, the soil covers the seeds and aids germination. We recommend over seeding in two applications with the second application made at a 45 degree angle to the first. You will notice a distinct pattern that will grow- in after the turf gets thicker. Water thoroughly as soon as over seeding is complete and continue to water lightly each day until the seeds germinate. Water regularly once the grass has sprouted to encourage deeper root growth.
2012年2月12日星期日
Oil change ends in flames
What started as a routine oil change ended with Yonas Bekele's 1993 Lexus bursting into flames at a local Jiffy Lube.
Now, he said, the car is too dangerous to drive unless he spends over $8,500 to make needed repairs -- leaving Bekele without a car to get from Plymouth to his classes at the University of Minnesota.
"I'm exhausted and mad," he said. "I'm having a hard time paying rent. I can't afford another payment."
After the fire broke out during the service, Jiffy Lube replaced some damaged components on Bekele's Lexus. But a spokesman for Heartland Automotive Services, Jiffy Lube's parent company in Texas, said Bekele's request for additional repairs reflected "unreasonable expectations for his older vehicle." The company said, however, that it will follow up to investigate his concerns.
Bekele, 31, is an Ethiopian native who lives in Plymouth and commutes to Minneapolis, where he studies construction management and civil engineering full time at the U. Five years ago, he bought a used Lexus ES 300, which he usually takes to the Jiffy Lube on Campus Drive in Plymouth.
On Jan. 23, Bekele took the Lexus in for an oil change. He was told by an employee that the fuel filter was dirty and needed to be changed. He took a seat in the waiting room and looked up at a TV monitor, which showed mechanics working in the garage.
"Suddenly I saw a fire through the monitor," Bekele recalled. "I looked around and my car is on fire."
As flames shot out of the engine bay, Bekele said mechanics scrambled to find a fire extinguisher and open the garage doors to let out the smoke.
A Jiffy Lube worker said that pieces weren't properly put back after the fuel filter replacement, Bekele said, causing gas to leak out and catch fire once the engine was turned on. However, Heartland Automotive Services spokesman Rob Rajkowski said the cause of the "small fire" is "unclear."
The mechanics apologized to him, Bekele said, and Jiffy Lube paid for a rental car for him to drive for three days as they repaired the car. According to invoices, they fixed the cap, ignition rotor and plug wires. Bekele wasn't convinced all the damage was repaired, so he paid to tow his car to Lexus of Wayzata.
There, mechanics found fire damage to the main engine wiring harness, firewall insulator and airbox, according to the invoice. Estimate for all of the repairs: $8,537.
Lexus of Wayzata general manager Robert Katz said that, given the car's age, "the value of it is probably less than the value to fix it."
Without the repairs, Bekele thinks the car isn't safe, so he hasn't driven it since. He has only liability insurance on the car, so he can't get help there. Bekele filed a complaint with Heartland Automotive Services, which is still pending.
Rajkowski said the company will follow up with Bekele to try to resolve the issue. "We understood he was satisfied with this resolution and have not heard from him since that date [Jan. 31, when they returned his car], so we were surprised the matter resurfaced," Rajkowski said.
After Whistleblower sent Jiffy Lube a copy of the repair estimate from Lexus of Wayzata, Rajkowski described it as "new information" that will be added to "that investigation as we work toward a final resolution."
Bekele said he will file a small claims case against Jiffy Lube, asking for a maximum $7,500. Meantime, he's borrowing his sister's vehicle as he searches for an affordable replacement for his Lexus.
Now, he said, the car is too dangerous to drive unless he spends over $8,500 to make needed repairs -- leaving Bekele without a car to get from Plymouth to his classes at the University of Minnesota.
"I'm exhausted and mad," he said. "I'm having a hard time paying rent. I can't afford another payment."
After the fire broke out during the service, Jiffy Lube replaced some damaged components on Bekele's Lexus. But a spokesman for Heartland Automotive Services, Jiffy Lube's parent company in Texas, said Bekele's request for additional repairs reflected "unreasonable expectations for his older vehicle." The company said, however, that it will follow up to investigate his concerns.
Bekele, 31, is an Ethiopian native who lives in Plymouth and commutes to Minneapolis, where he studies construction management and civil engineering full time at the U. Five years ago, he bought a used Lexus ES 300, which he usually takes to the Jiffy Lube on Campus Drive in Plymouth.
On Jan. 23, Bekele took the Lexus in for an oil change. He was told by an employee that the fuel filter was dirty and needed to be changed. He took a seat in the waiting room and looked up at a TV monitor, which showed mechanics working in the garage.
"Suddenly I saw a fire through the monitor," Bekele recalled. "I looked around and my car is on fire."
As flames shot out of the engine bay, Bekele said mechanics scrambled to find a fire extinguisher and open the garage doors to let out the smoke.
A Jiffy Lube worker said that pieces weren't properly put back after the fuel filter replacement, Bekele said, causing gas to leak out and catch fire once the engine was turned on. However, Heartland Automotive Services spokesman Rob Rajkowski said the cause of the "small fire" is "unclear."
The mechanics apologized to him, Bekele said, and Jiffy Lube paid for a rental car for him to drive for three days as they repaired the car. According to invoices, they fixed the cap, ignition rotor and plug wires. Bekele wasn't convinced all the damage was repaired, so he paid to tow his car to Lexus of Wayzata.
There, mechanics found fire damage to the main engine wiring harness, firewall insulator and airbox, according to the invoice. Estimate for all of the repairs: $8,537.
Lexus of Wayzata general manager Robert Katz said that, given the car's age, "the value of it is probably less than the value to fix it."
Without the repairs, Bekele thinks the car isn't safe, so he hasn't driven it since. He has only liability insurance on the car, so he can't get help there. Bekele filed a complaint with Heartland Automotive Services, which is still pending.
Rajkowski said the company will follow up with Bekele to try to resolve the issue. "We understood he was satisfied with this resolution and have not heard from him since that date [Jan. 31, when they returned his car], so we were surprised the matter resurfaced," Rajkowski said.
After Whistleblower sent Jiffy Lube a copy of the repair estimate from Lexus of Wayzata, Rajkowski described it as "new information" that will be added to "that investigation as we work toward a final resolution."
Bekele said he will file a small claims case against Jiffy Lube, asking for a maximum $7,500. Meantime, he's borrowing his sister's vehicle as he searches for an affordable replacement for his Lexus.
2012年2月9日星期四
As seasons turn, some wild animals adapt their looks to blend in
Hide and seek may be a favorite children's game, but for wildlife it is a survival tactic. Staying out of sight is important to daily life -- either to catch the next meal or avoid being the meal.
Many predators have to sneak up silently on their prey, and blending in with the surroundings helps. Likewise, one of the best defenses for prey animals, like rabbits and hares, is not to be seen. Using camouflage helps them as they remain very still to go unnoticed by a nearby predator. All is fair on nature's hunting grounds.
Snowshoe hares have a bigger challenge. Living at 8,000 to 11,000 feet elevation in Colorado, they spend the winters in snow-covered terrain. Their brown fur would stand out, so each autumn as days shorten, brown fur is shed and replaced by white fur that provides camouflage against the snowy background.
The fur itself does not change color; it is entirely replaced. Fur and feathers are dead tissue, like human fingernails. In order to change color, old fur must be shed so that new fur can grown in.
Winter fur color coincides with an increase in the production of the chemical melatonin, secreted into the blood by the brain's pineal gland. Darkness, or shorter daylight hours, triggers more of the chemical's release. The reverse color change takes place in spring as daylight hours increase and less melatonin is produced.
Snowshoe hares have other winter adaptations as well. Their large feet help them maneuver on top of the snow as they look for buds, twigs and bark to subsist on until spring returns.
The white-tailed jackrabbit (actually a hare), found from the plains to the tundra, also grows white fur in winter.
On the predator side, weasels turn winter white. There are two species of weasels in this area: short-tailed (also called ermine) and long-tailed. These fierce little critters make up for their size in attitude and strength. According to David Armstrong's Rocky Mountain Mammals handbook, short-tailed weasels are about 7-8 inches long, weighing only 1-2 ounces, and their long-tailed cousins are 12-18 inches long, weighing in at just 3.5 to 7 ounces. Armstrong notes that weasels use their long, slender bodies to wrap around prey to subdue it if needed, and land a powerful bite to the neck with their sharp teeth.
Weasels eat a variety of animals, including chipmunks, voles, baby hares or rabbits, small birds and amphibians, and other rodents, and often use the fur of their prey to line their nests.
Leanne Benton, interpretive ranger at Rocky Mountain National Park, is fascinated with weasels and does an evening program on the topic. She says in this region, weasels begin to grow white fur in October and regain their brown fur in March.
While fur color change is triggered by shorter or longer daylight hours, Benton says there seems to be a genetic component as well.
"Weasels in southern areas without snow don't turn white, and when brought north, they still don't turn white," she explains. "Northern weasels taken to southern areas will continue to turn white."
White fur may also provide an insulation benefit. "Without color pigments, the individual hairs have airspaces within them instead," says Benton, "and since air is a great insulator, white hairs keep you a tad warmer."
Mammals are not the only creatures that change color in winter. The white-tailed ptarmigan, a bird in the grouse family, subsists in the alpine tundra all winter long, losing its brown mottled feathers in late fall to be replaced by white feathers.
Even in summer, ptarmigans are difficult to see. They blend in so well with the brown colors of the tundra and are often not noticed by people until almost accidentally stepped on along a trail. In winter, their white feathers hide them in the snow, with only black eyes and beaks giving away their location.
Huddling under willow shrubs, ptarmigans stay warm in beds of insulating snow and subsist on willow buds. Their snowshoe feet are thickly feathered in winter.
Nature's colors are esthetically pleasing, but those color changes provide for lifesaving games of hide and seek. Look carefully and see what blends in.
Many predators have to sneak up silently on their prey, and blending in with the surroundings helps. Likewise, one of the best defenses for prey animals, like rabbits and hares, is not to be seen. Using camouflage helps them as they remain very still to go unnoticed by a nearby predator. All is fair on nature's hunting grounds.
Snowshoe hares have a bigger challenge. Living at 8,000 to 11,000 feet elevation in Colorado, they spend the winters in snow-covered terrain. Their brown fur would stand out, so each autumn as days shorten, brown fur is shed and replaced by white fur that provides camouflage against the snowy background.
The fur itself does not change color; it is entirely replaced. Fur and feathers are dead tissue, like human fingernails. In order to change color, old fur must be shed so that new fur can grown in.
Winter fur color coincides with an increase in the production of the chemical melatonin, secreted into the blood by the brain's pineal gland. Darkness, or shorter daylight hours, triggers more of the chemical's release. The reverse color change takes place in spring as daylight hours increase and less melatonin is produced.
Snowshoe hares have other winter adaptations as well. Their large feet help them maneuver on top of the snow as they look for buds, twigs and bark to subsist on until spring returns.
The white-tailed jackrabbit (actually a hare), found from the plains to the tundra, also grows white fur in winter.
On the predator side, weasels turn winter white. There are two species of weasels in this area: short-tailed (also called ermine) and long-tailed. These fierce little critters make up for their size in attitude and strength. According to David Armstrong's Rocky Mountain Mammals handbook, short-tailed weasels are about 7-8 inches long, weighing only 1-2 ounces, and their long-tailed cousins are 12-18 inches long, weighing in at just 3.5 to 7 ounces. Armstrong notes that weasels use their long, slender bodies to wrap around prey to subdue it if needed, and land a powerful bite to the neck with their sharp teeth.
Weasels eat a variety of animals, including chipmunks, voles, baby hares or rabbits, small birds and amphibians, and other rodents, and often use the fur of their prey to line their nests.
Leanne Benton, interpretive ranger at Rocky Mountain National Park, is fascinated with weasels and does an evening program on the topic. She says in this region, weasels begin to grow white fur in October and regain their brown fur in March.
While fur color change is triggered by shorter or longer daylight hours, Benton says there seems to be a genetic component as well.
"Weasels in southern areas without snow don't turn white, and when brought north, they still don't turn white," she explains. "Northern weasels taken to southern areas will continue to turn white."
White fur may also provide an insulation benefit. "Without color pigments, the individual hairs have airspaces within them instead," says Benton, "and since air is a great insulator, white hairs keep you a tad warmer."
Mammals are not the only creatures that change color in winter. The white-tailed ptarmigan, a bird in the grouse family, subsists in the alpine tundra all winter long, losing its brown mottled feathers in late fall to be replaced by white feathers.
Even in summer, ptarmigans are difficult to see. They blend in so well with the brown colors of the tundra and are often not noticed by people until almost accidentally stepped on along a trail. In winter, their white feathers hide them in the snow, with only black eyes and beaks giving away their location.
Huddling under willow shrubs, ptarmigans stay warm in beds of insulating snow and subsist on willow buds. Their snowshoe feet are thickly feathered in winter.
Nature's colors are esthetically pleasing, but those color changes provide for lifesaving games of hide and seek. Look carefully and see what blends in.
2012年2月8日星期三
Ross Andrews Column Various Veins
"Oh oh," said Martha as we came up the sidewalk.
"What?" I said.
"They're going to get their noses nipped," she said, pointing to little green shoots poking up through the mulch.
I don't know what they are, maybe daffodils or hyacinths. They are answering the sun's untimely wake up call in the shelter of shrubbery and our plastic garage.
The sun reminds me of my dad waking me and my cousin with a cheery, "Hurrah boys!" as he flipped the light switch by the bedroom door.
Dad's call to duty, although we considered it bordering on masochism, was within reason. There were horses to be fed and harnessed, tobacco to be primed, and often a kiln to be emptied to make way for the day's harvest.
And there was breakfast.
But this sun has lost its mind, melting the snow coverlet, coaxing the bulbs to send up tender sprouts, and the end of winter still at least a month and a half in the future.
A flock of starlings on Sunday swept like a medieval company of gleaners over our neighbour's lawn across the street. Finished there they crossed to our yard and pecked away at something, weed seeds likely in our case. Isn't it early for starlings to be here?
Snow buntings haunt the shrubbery outside the den window where I peck away at my keyboard. They hop from twig to twig picking at scale-like bits that require repeated spitting out and picking up. Their crops must be scoured raw by such fodder. When the snow melts they disappear only to come back when the snow does. There must be an endless supply of edibles on that bush as well as protection from the occasional hawk.
Two or three neighbourhood cats come and wait under there in hopes of snagging a feathery morsel. I haven't witnessed a kill but the sleek winter coats indicate a plentiful supply of food for these felines. Our son's home is over on the next block, his garden extending to our street. One of the cats has a retreat under his back deck and we know he puts food out for it.
We were in Tillsonburg on Saturday shopping for wallpaper. Chatting with the clerk who hasn't been in this area for long, I described how for many years snow was piled in the middle of Broadway at this time of year until it could be trucked to a disposal area. We'd have to scramble over a ridge at the curb to reach the sidewalk in those days. This season, can't hardly call it winter, we need boots to wade through puddles.
We know from the news that this is not a global condition. People are freezing to death in Europe.
I learned many years ago how to build an igloo with blocks of snow carved from drifts. We have pictures of our kids looking out from the entrance tunnels of these structures. We didn't hollow out banks left along the streets by snowplows. That can be deadly in the event of a cave-in or being hit by a plow winging back snow.
A proper igloo is self supporting, the blocks settled and more or less welded to one another in a spiral that forms a dome. A key block of snow set in the final opening gives the strength of a masonry arch. You may create a window with a pane of clear ice in lieu of snow.
Snow is a good insulator as well as protection from wind chill. Maybe someone should teach the people in the snowy regions how to protect themselves with igloos. The only tool you need is a snow knife to cut the blocks and settle them against one another. A handsaw will do.
"What?" I said.
"They're going to get their noses nipped," she said, pointing to little green shoots poking up through the mulch.
I don't know what they are, maybe daffodils or hyacinths. They are answering the sun's untimely wake up call in the shelter of shrubbery and our plastic garage.
The sun reminds me of my dad waking me and my cousin with a cheery, "Hurrah boys!" as he flipped the light switch by the bedroom door.
Dad's call to duty, although we considered it bordering on masochism, was within reason. There were horses to be fed and harnessed, tobacco to be primed, and often a kiln to be emptied to make way for the day's harvest.
And there was breakfast.
But this sun has lost its mind, melting the snow coverlet, coaxing the bulbs to send up tender sprouts, and the end of winter still at least a month and a half in the future.
A flock of starlings on Sunday swept like a medieval company of gleaners over our neighbour's lawn across the street. Finished there they crossed to our yard and pecked away at something, weed seeds likely in our case. Isn't it early for starlings to be here?
Snow buntings haunt the shrubbery outside the den window where I peck away at my keyboard. They hop from twig to twig picking at scale-like bits that require repeated spitting out and picking up. Their crops must be scoured raw by such fodder. When the snow melts they disappear only to come back when the snow does. There must be an endless supply of edibles on that bush as well as protection from the occasional hawk.
Two or three neighbourhood cats come and wait under there in hopes of snagging a feathery morsel. I haven't witnessed a kill but the sleek winter coats indicate a plentiful supply of food for these felines. Our son's home is over on the next block, his garden extending to our street. One of the cats has a retreat under his back deck and we know he puts food out for it.
We were in Tillsonburg on Saturday shopping for wallpaper. Chatting with the clerk who hasn't been in this area for long, I described how for many years snow was piled in the middle of Broadway at this time of year until it could be trucked to a disposal area. We'd have to scramble over a ridge at the curb to reach the sidewalk in those days. This season, can't hardly call it winter, we need boots to wade through puddles.
We know from the news that this is not a global condition. People are freezing to death in Europe.
I learned many years ago how to build an igloo with blocks of snow carved from drifts. We have pictures of our kids looking out from the entrance tunnels of these structures. We didn't hollow out banks left along the streets by snowplows. That can be deadly in the event of a cave-in or being hit by a plow winging back snow.
A proper igloo is self supporting, the blocks settled and more or less welded to one another in a spiral that forms a dome. A key block of snow set in the final opening gives the strength of a masonry arch. You may create a window with a pane of clear ice in lieu of snow.
Snow is a good insulator as well as protection from wind chill. Maybe someone should teach the people in the snowy regions how to protect themselves with igloos. The only tool you need is a snow knife to cut the blocks and settle them against one another. A handsaw will do.
2012年2月7日星期二
Power outage shocks businesses
A large power outage sent holiday-makers heading for home in the popular Whangaruru Harbour area, as water and petrol pumps failed, toilets could not be flushed and fridges and freezers fell silent during the weekend.
Some campervan and caravan tourists found themselves marooned on the coast because they did not have enough fuel to get to the nearest petrol station.
Lines company Northpower said it believes the outage may have been caused by an insulator and conductor being hit by a bullet. A helicopter brought in to assist with locating the fault spotted a damaged pole near the road on the boundary of a forest block near Mokau.
Power was restored to all customers by mid-day yesterday, but not before Travis O'Malley and Nena Rogers, owners of Oakura Bay Stores and The Tin Tui Cafe, had lost thousands of dollars in income and ruined stock.
The business runs 23 chillers and stock levels were extremely high at this time of the year, said Mr O'Malley.
"Deliveries are on the way as we speak and what do we do?" he asked.
The couple frantically moved product out of their biggest freezer to smaller ones in case sudden restoration of power blew out its compressor, involving huge repair costs.
"We've been through outages before and we know all about blown-out compressors. We've had eight in 16 years. The longest outage was 24 hours when a forestry company dropped a tree on the line. Outages have massive impact on a business like this.
"We are still recovering from the big storm of 2007 when the road was blocked for weeks and the expense of having to put in petrol pumps when Shell withdrew from the area the same year. This setback comes on top of a poor-performance summer. It's incredibly disappointing," Mr O'Malley said.
A generator big enough to keep all their chillers going through summer was beyond their financial resources. Stock losses were covered by insurance but the business had to pay the first $2000; meanwhile loss of trade over the last long weekend of summer was not covered. He said he feels sorriest for the people who earn a living looking after holiday homes.
"The owners couldn't clean up when they left. I know someone who has to go in and do the dishes and wash and clean everything in about 12 baches," he said.
Power began to fail intermittently just before the weekend in an area stretching from Whakapara 23km north-west of Whangarei, north to the area of Whangaruru harbour, including the Oakura settlement and Bland Bay, culminating in a complete outage from 4.30am on Monday.
General manager of Northpower's network division, Graham Dawson, said the fault would have been extremely difficult to spot quickly from the ground.
"We were almost at the point of having to climb every pole along that section of the line which would have been very time-consuming," he said. The company had done a huge amount of recent maintenance on the Helena Bay/Bland Bay line and there was more to come, he said, but in this case "there appeared to be possible third party damage to the insulator. The pole and cross-arm were in very good condition".
He said the company spent around $20 million annually on maintenance and asset replacement.
Some campervan and caravan tourists found themselves marooned on the coast because they did not have enough fuel to get to the nearest petrol station.
Lines company Northpower said it believes the outage may have been caused by an insulator and conductor being hit by a bullet. A helicopter brought in to assist with locating the fault spotted a damaged pole near the road on the boundary of a forest block near Mokau.
Power was restored to all customers by mid-day yesterday, but not before Travis O'Malley and Nena Rogers, owners of Oakura Bay Stores and The Tin Tui Cafe, had lost thousands of dollars in income and ruined stock.
The business runs 23 chillers and stock levels were extremely high at this time of the year, said Mr O'Malley.
"Deliveries are on the way as we speak and what do we do?" he asked.
The couple frantically moved product out of their biggest freezer to smaller ones in case sudden restoration of power blew out its compressor, involving huge repair costs.
"We've been through outages before and we know all about blown-out compressors. We've had eight in 16 years. The longest outage was 24 hours when a forestry company dropped a tree on the line. Outages have massive impact on a business like this.
"We are still recovering from the big storm of 2007 when the road was blocked for weeks and the expense of having to put in petrol pumps when Shell withdrew from the area the same year. This setback comes on top of a poor-performance summer. It's incredibly disappointing," Mr O'Malley said.
A generator big enough to keep all their chillers going through summer was beyond their financial resources. Stock losses were covered by insurance but the business had to pay the first $2000; meanwhile loss of trade over the last long weekend of summer was not covered. He said he feels sorriest for the people who earn a living looking after holiday homes.
"The owners couldn't clean up when they left. I know someone who has to go in and do the dishes and wash and clean everything in about 12 baches," he said.
Power began to fail intermittently just before the weekend in an area stretching from Whakapara 23km north-west of Whangarei, north to the area of Whangaruru harbour, including the Oakura settlement and Bland Bay, culminating in a complete outage from 4.30am on Monday.
General manager of Northpower's network division, Graham Dawson, said the fault would have been extremely difficult to spot quickly from the ground.
"We were almost at the point of having to climb every pole along that section of the line which would have been very time-consuming," he said. The company had done a huge amount of recent maintenance on the Helena Bay/Bland Bay line and there was more to come, he said, but in this case "there appeared to be possible third party damage to the insulator. The pole and cross-arm were in very good condition".
He said the company spent around $20 million annually on maintenance and asset replacement.
2012年2月6日星期一
Man-made diamonds could unlock bionic eye
IT TAKES up to 3.3 billion years for nature to make a diamond. But physics professor Steven Prawer can cook them up in five days using the microwave-like reactor at his Parkville laboratory.
''They are made with methane and hydrogen,'' Professor Prawer said. ''You cook them in the microwave oven on high for five days and then you have lovely little diamonds.''
The diamonds - which come out black because of their tiny size which scatters the light - are likely to prove a key ingredient in Australia's $42 million quest to develop a bionic eye.
Advertisement: Story continues below
Diamonds have long been used in the body due to their durability and low rejection rate, with diamond coating applied to everything from heart valves to hip joints. They are also a common insulator. But Professor Prawer, inaugural head of the Melbourne Materials Institute at Melbourne University, said diamonds have never been used to stimulate the nerves.
''We have discovered a form of diamond that we can make which is bio-compatible and very good as a stimulating electrode, which means we can put an electrical signal onto it that then causes the neurons to fire and get a response,'' he said.
It's this novel approach being taken by the multi-disciplinary team behind Bionic Vision Australia that has researchers most excited. ''I don't think anyone ever believed that diamonds could be used to stimulate [the ganglion cells] … this is a uniquely Australian approach,'' Professor Prawer said.
He said establishing that diamonds could be used to stimulate nerves could have future applications in the treatment of other conditions such as Parkinson's disease and epilepsy.
The man-made diamonds will also be used to encapsulate the five-square-millimetre microchip, the engine of the bionic eye, which will be implanted into the retina.
With pre-clinical trials under way, the Bionic Vision Australia consortium - including Melbourne University, the Centre for Eye Research Australia, NICTA, the Bionics Institute and the University of New South Wales - hope that the first human implant will take place next year at the Victorian Eye and Ear Hospital.
In 2009, the federal government committed $50 million over four years to develop the bionic eye in Australia. While Bionic Vision Australia secured the lion's share, Monash University received $8 million to work on an implant which will stimulate the visual cortex within the brain, bypassing the eye and optic nerve.
''They are made with methane and hydrogen,'' Professor Prawer said. ''You cook them in the microwave oven on high for five days and then you have lovely little diamonds.''
The diamonds - which come out black because of their tiny size which scatters the light - are likely to prove a key ingredient in Australia's $42 million quest to develop a bionic eye.
Advertisement: Story continues below
Diamonds have long been used in the body due to their durability and low rejection rate, with diamond coating applied to everything from heart valves to hip joints. They are also a common insulator. But Professor Prawer, inaugural head of the Melbourne Materials Institute at Melbourne University, said diamonds have never been used to stimulate the nerves.
''We have discovered a form of diamond that we can make which is bio-compatible and very good as a stimulating electrode, which means we can put an electrical signal onto it that then causes the neurons to fire and get a response,'' he said.
It's this novel approach being taken by the multi-disciplinary team behind Bionic Vision Australia that has researchers most excited. ''I don't think anyone ever believed that diamonds could be used to stimulate [the ganglion cells] … this is a uniquely Australian approach,'' Professor Prawer said.
He said establishing that diamonds could be used to stimulate nerves could have future applications in the treatment of other conditions such as Parkinson's disease and epilepsy.
The man-made diamonds will also be used to encapsulate the five-square-millimetre microchip, the engine of the bionic eye, which will be implanted into the retina.
With pre-clinical trials under way, the Bionic Vision Australia consortium - including Melbourne University, the Centre for Eye Research Australia, NICTA, the Bionics Institute and the University of New South Wales - hope that the first human implant will take place next year at the Victorian Eye and Ear Hospital.
In 2009, the federal government committed $50 million over four years to develop the bionic eye in Australia. While Bionic Vision Australia secured the lion's share, Monash University received $8 million to work on an implant which will stimulate the visual cortex within the brain, bypassing the eye and optic nerve.
2012年2月5日星期日
Fickle winter weather jeopardizes farmers’ alfalfa crops
Mother Nature hasn’t been kind to farmers this winter.
Unusually mild and strange weather patterns have left farmers with alfalfa fields crossing their fingers, as cycles of freezing and thawing can cause winter kill by uprooting and damaging crops.
At stake is the alfalfa hay dairy farmers use as cattle feed, the loss of which can be major for small farms, said John E. Peck, 64, who operates a 347-acre dairy farm in the town of Champion with his son, John D., 28, who purchased the property from him in 2008.
“The one thing you get concerned with an open winter is it does leave the alfalfa crops vulnerable to frost damage,” Mr. Peck said, adding that the farm depends on the hay to feed a herd of 85 cows. “It can especially if we have zero and below-zero temperatures and the ground is bare, because the freezing action will heave the plants’ roots out of the ground.”
While a blanket of snow ordinarily covers the fields during the winter, serving as an insulator that guards the soil from freezing, that hasn’t been the case this winter, he said. Mild temperatures have kept snow off the ground, leaving the fields vulnerable.
“I’ve never seen a year like this, and I’ll be 65 in June,” Mr. Peck said with a laugh. “I didn’t plow snow in the farmyards until January 13, and it makes us nervous about the crops and what it could do.”
One advantage the farm has to ward off the weather, he said, is that its soil drains water well, lessening the amount of freezing caused by moisture buildup. Mr. Peck still is optimistic that his crops will be green when spring arrives. “I’m not looking for winter kill yet on our farm, but I’m more worried about what our water count in the soil come spring and summer will be if we don’t get enough rain,” he said.
Asked whether he’s concerned about his alfalfa crops, Douglas W. Shelmidine, owner of a dairy farm in the town of Ellisburg, said, “It’s too early to tell at this point, but it’s not the weather we want to have.”
But if the current cycle of freezing and thawing continues until late February, when alfalfa plants start to grow, that could jeopardize the crops, Mr. Shelmidine said.
“It becomes more critical as we get to that time when the plant starts to grow as the temperature warms up,” he said. “If the temperatures get cold enough and the ground starts to freeze and expand, that will pull the plants out of the soil.”
Farmers across the north country are concerned about how the strange weather patterns will affect their crops, particularly alfalfa plants, said Michael E. Hunter, field crops educator for Cornell Cooperative Extension of Jefferson County.
“Anytime we get fluctuating temperatures with freezing and thawing action, it will literally lift the alfalfa crown out of the soil,” Mr. Hunter said.
He said the plant’s taproots are pulled from the ground more easily than those with layers of roots, like grass. “The freezing and thawing can also break smaller roots attached, so that in the springtime, the plant can’t get the water and nutrients it needs and dies,” he said.
The low temperatures in January, coupled with less snowfall, have produced a dangerous climate for alfalfa plants, Mr. Hunter said. He said that temperatures dropped to as low as minus 24 degrees in January and that fields didn’t have adequate snow for protection.
Ideally, “you want to have at least six inches of snow cover on alfalfa fields to provide insulation for below-zero temperatures, which can kill plant tissue and cause winter kill,” Mr. Hunter said.
But while farmers can’t do anything to change the fickle weather, there are several controllable precautions they can take to protect their alfalfa crops in the fall, Mr. Hunter said. For instance, farmers should ensure their alfalfa stands are planted in fertile soil with a pH level of 6.5 to 7, which is the best level of acidity for absorbing nutrients. Older alfalfa stands, in particular, need to get the proper nutrition because they are more likely to die.
Farmers also should make sure the plants have enough rest time in the fall — at least 45 days — to store carbohydrates for the winter before the last cutting of the season, Mr. Hunter said. To do so, the fields should be cut in early August and again in October following the waiting period. The alfalfa should be cut to have at least 6 inches of stubble, which will help the plants trap snow and provide insulation.
“If you harvest the plants early, they don’t get the opportunity to build up root reserves needed because you’re intercepting the process,” Mr. Hunter said.
While this winter’s erratic weather has certainly increased the risk of losing crops, farmers who took the right precautions may be able to weather the storm, so to speak.
Unusually mild and strange weather patterns have left farmers with alfalfa fields crossing their fingers, as cycles of freezing and thawing can cause winter kill by uprooting and damaging crops.
At stake is the alfalfa hay dairy farmers use as cattle feed, the loss of which can be major for small farms, said John E. Peck, 64, who operates a 347-acre dairy farm in the town of Champion with his son, John D., 28, who purchased the property from him in 2008.
“The one thing you get concerned with an open winter is it does leave the alfalfa crops vulnerable to frost damage,” Mr. Peck said, adding that the farm depends on the hay to feed a herd of 85 cows. “It can especially if we have zero and below-zero temperatures and the ground is bare, because the freezing action will heave the plants’ roots out of the ground.”
While a blanket of snow ordinarily covers the fields during the winter, serving as an insulator that guards the soil from freezing, that hasn’t been the case this winter, he said. Mild temperatures have kept snow off the ground, leaving the fields vulnerable.
“I’ve never seen a year like this, and I’ll be 65 in June,” Mr. Peck said with a laugh. “I didn’t plow snow in the farmyards until January 13, and it makes us nervous about the crops and what it could do.”
One advantage the farm has to ward off the weather, he said, is that its soil drains water well, lessening the amount of freezing caused by moisture buildup. Mr. Peck still is optimistic that his crops will be green when spring arrives. “I’m not looking for winter kill yet on our farm, but I’m more worried about what our water count in the soil come spring and summer will be if we don’t get enough rain,” he said.
Asked whether he’s concerned about his alfalfa crops, Douglas W. Shelmidine, owner of a dairy farm in the town of Ellisburg, said, “It’s too early to tell at this point, but it’s not the weather we want to have.”
But if the current cycle of freezing and thawing continues until late February, when alfalfa plants start to grow, that could jeopardize the crops, Mr. Shelmidine said.
“It becomes more critical as we get to that time when the plant starts to grow as the temperature warms up,” he said. “If the temperatures get cold enough and the ground starts to freeze and expand, that will pull the plants out of the soil.”
Farmers across the north country are concerned about how the strange weather patterns will affect their crops, particularly alfalfa plants, said Michael E. Hunter, field crops educator for Cornell Cooperative Extension of Jefferson County.
“Anytime we get fluctuating temperatures with freezing and thawing action, it will literally lift the alfalfa crown out of the soil,” Mr. Hunter said.
He said the plant’s taproots are pulled from the ground more easily than those with layers of roots, like grass. “The freezing and thawing can also break smaller roots attached, so that in the springtime, the plant can’t get the water and nutrients it needs and dies,” he said.
The low temperatures in January, coupled with less snowfall, have produced a dangerous climate for alfalfa plants, Mr. Hunter said. He said that temperatures dropped to as low as minus 24 degrees in January and that fields didn’t have adequate snow for protection.
Ideally, “you want to have at least six inches of snow cover on alfalfa fields to provide insulation for below-zero temperatures, which can kill plant tissue and cause winter kill,” Mr. Hunter said.
But while farmers can’t do anything to change the fickle weather, there are several controllable precautions they can take to protect their alfalfa crops in the fall, Mr. Hunter said. For instance, farmers should ensure their alfalfa stands are planted in fertile soil with a pH level of 6.5 to 7, which is the best level of acidity for absorbing nutrients. Older alfalfa stands, in particular, need to get the proper nutrition because they are more likely to die.
Farmers also should make sure the plants have enough rest time in the fall — at least 45 days — to store carbohydrates for the winter before the last cutting of the season, Mr. Hunter said. To do so, the fields should be cut in early August and again in October following the waiting period. The alfalfa should be cut to have at least 6 inches of stubble, which will help the plants trap snow and provide insulation.
“If you harvest the plants early, they don’t get the opportunity to build up root reserves needed because you’re intercepting the process,” Mr. Hunter said.
While this winter’s erratic weather has certainly increased the risk of losing crops, farmers who took the right precautions may be able to weather the storm, so to speak.
2012年2月2日星期四
The Weird Physics Behind The Jacob’s Ladder
In old movies, when there is electricity involved, there always seem to be two wires fanning out and a slowly-rising arc of electricity between them. This contraption is called Jacob's Ladder, and although it looks uselessly sci-fi, it was actually quite useful in machinery... a hundred years ago.
Jacob's Ladder is a piece of physics equipment that is both simple and showy, and so found itself right at home in Hollywood. It probably found bit parts in a bunch of horror and sci-fi movies, but its starring role was in the 1931 version of Frankenstein. In the famous "It's Alive!" scene, there are any number of electrical devices in the lab, and most of them are pictured as two wires, with an arc of electricity branching up between them until it crackles into the air. There are two in the lab, prominently displayed just the other side of the camera from Frankenstein's body, and there is one on the dais upon which the monster is raised. Their movie arcs of electricity make the scene look active and alive, even when Frankenstein's monster is just a corpse.
What's actually going on? Nothing sinister, but something a little bit dangerous. I certainly wouldn't want to be on a moving platform with a Jacob's Ladder device and a lot of flapping bed sheets. The device consists of two wires held close together. Beneath them is a device that will raise the electrical potential difference between them. Electrons are yearning to jump from one wire to the other, but the air between them acts as an insulator. Eventually, enough voltage will cause electrons to jump away from the air molecules they're associated with. They won't necessarily head to the wire, they'll just be separated from their atoms and molecules a bit. The air has now changed from a gas to a plasma. And the plasma, which is more free with its electrons, conducts electricity. The electrons zoom through the air from one wire to another, and we see an arc of light.
But why does it travel? Since the wires fan out, and the electrons will take the shortest jump they can find, there doesn't seem to be a reason for the electrical arc to move to where the wires are father apart.
The electrons do look for the path of least resistance, but the path of least resistance is always where the plasma is. And the moving electrons heat the plasma around them. This ionized air is less dense than the surrounding air, and moves upwards. The electrons follow it, until at last the jump becomes too far for them, and the connection is lost. Jacob's Ladder is an impressive looking prop, but it needs to be handled with care. The connection can, under the right circumstances, set fire to paper and cloth. Not something to have around an actor's pretty face or sprayed-up hair.
Jacob's Ladder seems pretty useless when it comes to pretty much everything but making movie audiences ooh and ah. It certainly wouldn't have brought anyone back to life — though if they were sleeping, I imagine being set on fire would wake them. Their actual use, back in the early 1900s, was much less glamorous. They ionized the nitrogen in air. Some of that nitrogen would re-combine with oxygen, making nitric oxide. This was used in fertilizer, so it is possible that Jacob's Ladder did 'give life' to something in a round-about way. That wouldn't have impressed Frankenstein, though.
Jacob's Ladder is a piece of physics equipment that is both simple and showy, and so found itself right at home in Hollywood. It probably found bit parts in a bunch of horror and sci-fi movies, but its starring role was in the 1931 version of Frankenstein. In the famous "It's Alive!" scene, there are any number of electrical devices in the lab, and most of them are pictured as two wires, with an arc of electricity branching up between them until it crackles into the air. There are two in the lab, prominently displayed just the other side of the camera from Frankenstein's body, and there is one on the dais upon which the monster is raised. Their movie arcs of electricity make the scene look active and alive, even when Frankenstein's monster is just a corpse.
What's actually going on? Nothing sinister, but something a little bit dangerous. I certainly wouldn't want to be on a moving platform with a Jacob's Ladder device and a lot of flapping bed sheets. The device consists of two wires held close together. Beneath them is a device that will raise the electrical potential difference between them. Electrons are yearning to jump from one wire to the other, but the air between them acts as an insulator. Eventually, enough voltage will cause electrons to jump away from the air molecules they're associated with. They won't necessarily head to the wire, they'll just be separated from their atoms and molecules a bit. The air has now changed from a gas to a plasma. And the plasma, which is more free with its electrons, conducts electricity. The electrons zoom through the air from one wire to another, and we see an arc of light.
But why does it travel? Since the wires fan out, and the electrons will take the shortest jump they can find, there doesn't seem to be a reason for the electrical arc to move to where the wires are father apart.
The electrons do look for the path of least resistance, but the path of least resistance is always where the plasma is. And the moving electrons heat the plasma around them. This ionized air is less dense than the surrounding air, and moves upwards. The electrons follow it, until at last the jump becomes too far for them, and the connection is lost. Jacob's Ladder is an impressive looking prop, but it needs to be handled with care. The connection can, under the right circumstances, set fire to paper and cloth. Not something to have around an actor's pretty face or sprayed-up hair.
Jacob's Ladder seems pretty useless when it comes to pretty much everything but making movie audiences ooh and ah. It certainly wouldn't have brought anyone back to life — though if they were sleeping, I imagine being set on fire would wake them. Their actual use, back in the early 1900s, was much less glamorous. They ionized the nitrogen in air. Some of that nitrogen would re-combine with oxygen, making nitric oxide. This was used in fertilizer, so it is possible that Jacob's Ladder did 'give life' to something in a round-about way. That wouldn't have impressed Frankenstein, though.
2012年2月1日星期三
Winnipeg fog blamed for fire, poor visibility
Damp, foggy air caused a number of problems around Winnipeg on Wednesday morning.
While it crystalized as hoar frost and created picturesque scenes on trees and other objects, it also created extremely poor visibility on roads and highways and was blamed for a hydro pole fire in East Kildonan.
Tim Blazanovic, spokesperson for Manitoba Infrastructure and Transportation, said visibility in some areas was less than 50 meters.
“Make sure you give yourself travelling distance behind other vehicles. In that kind of thick fog, if you’re going too fast, by the time you realize there’s someone there, it’s too late,” he said.
The fire, in the area of Raleigh Street and Greene Avenue, broke out at about 6:30 a.m.
The dampness enables electricity in the power lines to arc across the insulator and spark a pole-top fire.
Hydro spokesperson Scott Powell said it can be quite common in foggy weather to have such fires.
The dampness caused power havoc in the spring of 2010, disrupting the flow to downtown and triggering computer glitches and traffic light outages in several areas of the city.
There were no reports of power outages in Wednesday’s fire but there was some concern the flames would burn through the lines and cause them to drop to the ground.
The fog also caused the cancellation of a flight from Winnipeg to Minneapolis on Wednesday morning — because the plane wasn’t available.
The Delta Airlines flight was supposed to arrive in Winnipeg on Tuesday night (then take off the next morning) but the pilot turned back because of the fog.
There are no other fog-related flight delays or cancellations, according to the Winnipeg Airports Authority. But people are advised to check with their airline before heading to the airport, just to be sure.
While it crystalized as hoar frost and created picturesque scenes on trees and other objects, it also created extremely poor visibility on roads and highways and was blamed for a hydro pole fire in East Kildonan.
Tim Blazanovic, spokesperson for Manitoba Infrastructure and Transportation, said visibility in some areas was less than 50 meters.
“Make sure you give yourself travelling distance behind other vehicles. In that kind of thick fog, if you’re going too fast, by the time you realize there’s someone there, it’s too late,” he said.
The fire, in the area of Raleigh Street and Greene Avenue, broke out at about 6:30 a.m.
The dampness enables electricity in the power lines to arc across the insulator and spark a pole-top fire.
Hydro spokesperson Scott Powell said it can be quite common in foggy weather to have such fires.
The dampness caused power havoc in the spring of 2010, disrupting the flow to downtown and triggering computer glitches and traffic light outages in several areas of the city.
There were no reports of power outages in Wednesday’s fire but there was some concern the flames would burn through the lines and cause them to drop to the ground.
The fog also caused the cancellation of a flight from Winnipeg to Minneapolis on Wednesday morning — because the plane wasn’t available.
The Delta Airlines flight was supposed to arrive in Winnipeg on Tuesday night (then take off the next morning) but the pilot turned back because of the fog.
There are no other fog-related flight delays or cancellations, according to the Winnipeg Airports Authority. But people are advised to check with their airline before heading to the airport, just to be sure.
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