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Friday, 6 April 2012
Carrie Underwood Hates Sleeping with Hubby on Buses!
When she's on one of her concert tours, Carrie Underwood needs peace, quiet, and space away from her husband Mike Fisher. It's not that the country star isn't head-over-heels in love with her hubby of nearly two years -- she just can't sleep with him on a tour bus.
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Shifting sands
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Public release date: 5-Apr-2012[ | E-mail |
Share ] Contact: Caroline McCall
cmccall5@mit.edu
Massachusetts Institute of Technology
New model predicts how sand and other granular materials flow
CAMBRIDGE, Mass. -- Sand in an hourglass might seem simple and straightforward, but such granular materials are actually tricky to model. From far away, flowing sand resembles a liquid, streaming down the center of an hourglass like water from a faucet. But up close, one can make out individual grains that slide against each other, forming a mound at the base that holds its shape, much like a solid.
Sand's curious behavior part fluid, part solid has made it difficult for researchers to predict how it and other granular materials flow under various conditions. A precise model for granular flow would be particularly useful in optimizing processes such as pharmaceutical manufacturing and grain production, where tiny pills and grains pour through industrial chutes and silos in mass quantities. When they aren't well-controlled, such large-scale flows can cause blockages that are costly and sometimes dangerous to clear.
Now Ken Kamrin of MIT's Department of Mechanical Engineering has come up with a model that predicts the flow of granular materials under a variety of conditions. The model improves on existing models by taking into account one important factor: how the size of a grain affects the entire flow. Kamrin used the new model to predict sand flow in several configurations including a chute and a circular trough and found that the model's predictions were a near-perfect match with actual results. A paper detailing the new model will appear in the journal Physical Review Letters.
"The basic equations governing water flow have been known for over a century," says Kamrin, the Class of '56 Career Development Assistant Professor of Mechanical Engineering. "There hasn't been something similar for sand, where I can give you a cupful of sand, and tell you which equations will be necessary to predict how it will squish around if I squeeze the cup."
Blurring the lines
Kamrin explains that developing a flow model also known as a continuum model essentially means "blurring out" individual grains or molecules. While a computer may be programmed to predict the behavior of every single molecule in, say, a cup of flowing water, Kamrin says this exercise would take years. Instead, researchers have developed continuum models. They imagine dividing the cup into a patchwork of tiny cubes of water, each cube small compared to the size of the entire flow environment, yet large enough to contain many molecules and molecular collisions. Researchers can perform basic lab experiments on a single cube of water, analyzing how the cube deforms under different stresses. To efficiently predict how water flows in the cup, they solve a differential equation that applies the behavior of a single cube to every cube in the cup's grid.
Such models work well for fluids like water, which is easily divisible into particles that are almost infinitesimally small. However, grains of sand are much larger than water molecules and Kamrin found that the size of an individual grain can significantly affect the accuracy of a continuum model.
For example, a model can precisely estimate how water molecules flow in a cup, mainly because the size of a molecule is so much smaller than the cup itself. For the same relative scale in the flow of sand grains, Kamrin says, the sand's container would have to be the size of San Francisco.
Neighboring chatter
But why exactly does size matter? Kamrin reasons that when modeling water flow, molecules are so small that their effects stay within their respective cubes. As a result, a model that averages the behavior of every cube in a grid, and assumes each cube is a separate entity, gives a fairly accurate flow estimate. However, Kamrin says in granular flow, much larger grains such as sand can cause "bleed over" into neighboring cubes, creating cascade effects that are not accounted for in existing models.
"There's more chatter between neighbors," Kamrin says. "It's like the basic mechanical properties of a cube of grains become influenced by the movement of neighboring cubes."
Kamrin modified equations for an existing continuum model to factor in grain size, and tested his model on several configurations, including sand flowing through a chute and rotating in a circular trough. The new model not only predicted areas of fast-flowing grains, but also where grains would be slow moving, at the very edges of each configuration areas traditional models assumed would be completely static. The new model's predictions matched very closely with particle-by-particle simulations in the same configurations.
The model, run on a computer, can produce accurate flow fields in minutes, and could benefit engineers designing manufacturing processes for pharmaceuticals and agricultural products. For example, Kamrin says, engineers could test various shapes of chutes and troughs in the model to find a geometry that maximizes flow, or mitigates potentially dangerous wall pressure, before ever actually designing or building equipment to process granular materials.
Kamrin says understanding how granular materials flow could also help predict geological phenomena such as landslides and avalanches and help engineers come up with new ways to generate better traction in sand.
"Granular material is the second-most-handled material in industry, second only to water," Kamrin says. "I'm convinced there are a million applications."
###
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AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
Public release date: 5-Apr-2012[ | E-mail |
Share ] Contact: Caroline McCall
cmccall5@mit.edu
Massachusetts Institute of Technology
New model predicts how sand and other granular materials flow
CAMBRIDGE, Mass. -- Sand in an hourglass might seem simple and straightforward, but such granular materials are actually tricky to model. From far away, flowing sand resembles a liquid, streaming down the center of an hourglass like water from a faucet. But up close, one can make out individual grains that slide against each other, forming a mound at the base that holds its shape, much like a solid.
Sand's curious behavior part fluid, part solid has made it difficult for researchers to predict how it and other granular materials flow under various conditions. A precise model for granular flow would be particularly useful in optimizing processes such as pharmaceutical manufacturing and grain production, where tiny pills and grains pour through industrial chutes and silos in mass quantities. When they aren't well-controlled, such large-scale flows can cause blockages that are costly and sometimes dangerous to clear.
Now Ken Kamrin of MIT's Department of Mechanical Engineering has come up with a model that predicts the flow of granular materials under a variety of conditions. The model improves on existing models by taking into account one important factor: how the size of a grain affects the entire flow. Kamrin used the new model to predict sand flow in several configurations including a chute and a circular trough and found that the model's predictions were a near-perfect match with actual results. A paper detailing the new model will appear in the journal Physical Review Letters.
"The basic equations governing water flow have been known for over a century," says Kamrin, the Class of '56 Career Development Assistant Professor of Mechanical Engineering. "There hasn't been something similar for sand, where I can give you a cupful of sand, and tell you which equations will be necessary to predict how it will squish around if I squeeze the cup."
Blurring the lines
Kamrin explains that developing a flow model also known as a continuum model essentially means "blurring out" individual grains or molecules. While a computer may be programmed to predict the behavior of every single molecule in, say, a cup of flowing water, Kamrin says this exercise would take years. Instead, researchers have developed continuum models. They imagine dividing the cup into a patchwork of tiny cubes of water, each cube small compared to the size of the entire flow environment, yet large enough to contain many molecules and molecular collisions. Researchers can perform basic lab experiments on a single cube of water, analyzing how the cube deforms under different stresses. To efficiently predict how water flows in the cup, they solve a differential equation that applies the behavior of a single cube to every cube in the cup's grid.
Such models work well for fluids like water, which is easily divisible into particles that are almost infinitesimally small. However, grains of sand are much larger than water molecules and Kamrin found that the size of an individual grain can significantly affect the accuracy of a continuum model.
For example, a model can precisely estimate how water molecules flow in a cup, mainly because the size of a molecule is so much smaller than the cup itself. For the same relative scale in the flow of sand grains, Kamrin says, the sand's container would have to be the size of San Francisco.
Neighboring chatter
But why exactly does size matter? Kamrin reasons that when modeling water flow, molecules are so small that their effects stay within their respective cubes. As a result, a model that averages the behavior of every cube in a grid, and assumes each cube is a separate entity, gives a fairly accurate flow estimate. However, Kamrin says in granular flow, much larger grains such as sand can cause "bleed over" into neighboring cubes, creating cascade effects that are not accounted for in existing models.
"There's more chatter between neighbors," Kamrin says. "It's like the basic mechanical properties of a cube of grains become influenced by the movement of neighboring cubes."
Kamrin modified equations for an existing continuum model to factor in grain size, and tested his model on several configurations, including sand flowing through a chute and rotating in a circular trough. The new model not only predicted areas of fast-flowing grains, but also where grains would be slow moving, at the very edges of each configuration areas traditional models assumed would be completely static. The new model's predictions matched very closely with particle-by-particle simulations in the same configurations.
The model, run on a computer, can produce accurate flow fields in minutes, and could benefit engineers designing manufacturing processes for pharmaceuticals and agricultural products. For example, Kamrin says, engineers could test various shapes of chutes and troughs in the model to find a geometry that maximizes flow, or mitigates potentially dangerous wall pressure, before ever actually designing or building equipment to process granular materials.
Kamrin says understanding how granular materials flow could also help predict geological phenomena such as landslides and avalanches and help engineers come up with new ways to generate better traction in sand.
"Granular material is the second-most-handled material in industry, second only to water," Kamrin says. "I'm convinced there are a million applications."
###
[ | E-mail | Share ] ?
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.
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Oil prices recover from sharp losses
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faithtuppers - Why do not we eliminate the income tax and ...
Question by northam43 : Why do not we eliminate the income tax and dues Establish citizenship ?
The Government represents and provides services to all American citizens. So why should not all American citizens be required to pay an annual citizenship due? On November 1 each year the citizenship would be due based upon deterministic mined the governments budget requirements for the next year. Those failing to pay would be deported. For those that owned trucks and cars and hi-ways roads a tax would be collected each year you registered your vehicles.This would vastly reduce the size of the IRS. Saving the government millions / billions of dollars. Corporate taxes would be eliminated, this would lower the cost of goods to the consumer. The Government would not be allowed to spend beyond the budget. For those wanting a government retirement they could pay into a retirement plan and the government would invest the funds. Or you could get a retirement with your company or you could maintain your own individual retirement account. Health care could also be done the same way. We could eliminate social security. Welfare would be eliminated, everyone would be required to work in occupation of that they were physically able. There would be no disability. If a person was not physically able to perform any job in the U.S. (they may have to relocate), then the government would take care of those persons in a long term care facility.A sales tax is an unfair tax. To me you are getting back to taxing those with the most money. The Government should not be providing services based upon a persons wealth. The military is to protect all of us, so we should all portions have to pay a fair.I would be infavor of the government setting a cap on how wealthy a person can be. Does a person really need a billion dollars?The Government would require all businesses to offer adequate pay, retirement plan at adequate (which would also cover healthcare costs during the retirement years), as well as adequate Health Care Sun that every person had a job in this country would have no problem paying their dues and maintaining an adequate citizenship standard of living.This is not communistic or marxist. Every person would have 99.9% of the rights they have today. The only difference is others will not have to pay for those that CAN WORK! We have a lot of lazy people in this country drawing disability that could infact work. I?m not looking for utopia. I just feel that even if your flipping hamburgers at McDonald?s 8 hours a day, they should be able to earn you a decent living. GREED is the main problem in this country. A business that can not adequately take care of their employees should not be in business. I agree that the Government is currently totally out of control and it looks like it will only get worse. We can not be wasting our time trying to take care of lazy unproductive people. I?ve seen individuals drawing 100% disability that can pull the trade at the casino a whole lot faster than I can.When you live in a condo, they normally require you to pay an association fee. Everyone that owns a condo association that pays the same fee regardless of how much money you make. The association fee usually covers the exterior maintenance of all units, Maintaining of the common areas ? ie pools, recreation centers, parking areas, security of the facility, etc. ? Our government should be no different. If your a resident in a city, you would pay a fee for the residence streets, sewer, trash, etc. ? Every resident would pay the same fee.Enforcement would be easy. It would be taken directly from the individuals paycheck. Those retired or living outside the United States would get a bill in the mail. Those failing to pay after a sufficent amount of warnings would loose their citizenship and deported or jailed thusly if no other country would take them.Some people just to surprise me how stupid they really are. If my program was established. The only major expense we would have would be the defense of our country. There would be no welfare programs. The roads and hi-ways would come under the Department of Motor Vehicles Which would be paid for when you registered your vehicles. I would estimate that we should be able to run this country on less than $ 800 per citizen per year. A family of four would be $ 3,200 per year or $ 267 per month, that would give the government 240,000,000,000. Those that did not pay their dues would loose their citizenship and face deportation or jailed if no other country would take them. You have to understand that businesses would pay no tax, prices would be Therefore 1/2 of what they are today. There would be no tax on your real estate and no tax on your property. There would be not tax on dividends or capital gains. A federal minimum wage of 3,000.00 per month would be established.The only reason this program would not work, is that the LAZY DEADBEATS do not want to WORK, they want it handed to them. That?s why they do not want to get rid of the IRS, it is a tool to redistribute the income. GET OFF YOUR DUFF AND PAY YOUR OWN WAY!Jails would actually end up adding to the revenue. Those jailed would only get a cot & 2 meals. I would hire the sheriff in Arizona to run the federal prison system would probably turn a jail The profit. So how many do you really think I would want to stay in my jail.Exxon made a profit quarter of last around 15 Bln. It paid 43% in taxes. If we eliminated the taxes. That would put over 6 bln back to the company that they could use to pay employee health care, retirement, develope and produce alternative energy, creating more high paying jobs. By paying a minimum wage of $ 3,000.00 per month. Families would not have to have both parents working. We could go back to a one earner family system Strengthen the family unit would act. Therefore, good high-paying jobs would be plentyful. As for Immagration, we need to stop the flow of illegal Immagration, those aliens permitted to work in the United States would only be allowed to work jobs that citizens do not want to do. The alien would have to purchase a work permit. The bottom line is everything can be paid for. The problem is our current welfare, disability, and other social programs are draining our resources and if something does not change our freedoms at maybe stack.Under my program what would I do to eliminate the deficit. There is not much you can do. You stop it from growing, then you start to eliminate it. As part of the budget would have a portion to be allocated to pay on the deficit. If we capped the wealth at a billion. Then those with a wealth over a billion would contribute the excess to the deficit. This would not be distributing the income, it would be paying down debt and the government would have no economic impact on the American citizen. Plus, any country that owed us money would have to pay up so anytime our military is used to protect another country, they would pay for it?s use. Example: Our military operation in Iraq. The first bit of oil would be used to pay for our military operational citizen, protecting another country that is in our interest should never be at the expense of the American. Best answer:
Answer by Tommy
how are you going to enforce that? especially if you deport your military. Interstate roads are free its part of the budget, manages its own city streets with its own taxes, and state roads have tolls.BASE TAXES ON FEDERAL BUDGET, do you know how much red tape and corruption there is in Washington, senators can say they need a pay increase to millions of dollars and tax payers will have to pay for that.ITS DUMB, take a lesson from power plants, they set a budget of X amount if they go over they get penalized, they go under they just lose that money. It forces them to better efficiency. The income of government workers will not be overinflated as it is todayHAHAHA your funny invest, government would invest your money Eliminating social security BUSH SAID THAT HAHA. Guess what, if he had gotten away with investing social security on the stock market, social security BEEN ELIMINATED DUE TO THE wouldve DEPRESSION!Utopia does not exist you alone can not create utopia it is near impossible some group wants to be angry, it would not solve anything. You tax the rich people guess what they?ll move else where so they dont get taxed that much OR become citizens of another country and run it elsewhere we lose moneyYour sound marxist ideals maybe you?ve read the communist manifesto a bit too much???First Abolition of property in land and application of all rents of land to public purposes.???Second A heavy progressive or graduated income tax.???Third Abolition of all right of inheritance.???4th Confiscation of the property of all emigrants and rebels.???5th Centralization of credit in the hands of the State, by means of a national bank with State capital and exclusive monopoly on.???6th Centralization of the means of communication and transport in the hands of the State.???7th Extension of factories and instruments of production owned by the State, the bringing into cultivation of waste-lands, and the improvement of the soil generated according rally in dance with a common plan.???8th Equal liability of all to labor. Establishment of industrial armies, especially for agriculture.???9th Combination of agriculture with manufacturing industries; gradual abolition of the distinction between town and country, by a more equable distribution of the population over the country.??10th Free education for all children in public schools. Abolition of children?s factory labor in its present Form. Combination of education with industrial production, & c., & C. [5]
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2600 Volume 1 released as a DRM-free ebook: phreak like it's 1984
Long-running hacker magazine 2600 has been digging into its archives quite a bit as of late (it began releasing videos of the early HOPE conferences in December), and it's now gone back right to the beginning for its latest offering. It's just released 2600: The Hacker Digest - Volume 1, a DRM-free ebook that collects its first year of newsletters -- reformatted in book form for easier reading, but with every last detail intact (including typos). That's available in both the Kindle and Nook stores, as well as through 2600's own site in plain old PDF form, each of which set you back just under $4. What's more, while there's no firm word on any additional volumes just yet, 2600 says it'll keep them coming if there's enough support for the first one.
2600 Volume 1 released as a DRM-free ebook: phreak like it's 1984 originally appeared on Engadget on Wed, 04 Apr 2012 07:29:00 EDT. Please see our terms for use of feeds.
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Science: Sorry! Online Dating Is Bullsh*t [Online Dating]
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