Graphene membranes: First controllable use of scanning tunneling microscopy on freestanding graphene

ScienceDaily (Apr. 2, 2012) ? Graphene could be the superhero of materials -- it's light, strong and conducts heat and electricity effectively, which makes it a great material for potential use in all kinds of electronics. And because it's made from carbon atoms, graphene is cheap and plentiful. Its electric and mechanical properties also affect one another in unique ways. But before freestanding graphene can live up to its potential, scientists need to be able to control these properties.

A group of physicists from the University of Arkansas and other institutions have developed a technique that allows them to control the mechanical property, or strain, on freestanding graphene, sheets of carbon one-atom thick suspended over the tops of tiny squares of copper. By controlling the strain on freestanding graphene, they also can control other properties of this important material.

"If you subject graphene to strain, you change its electronic properties," said physics professor Salvador Barraza-Lopez. Strain on freestanding graphene causes the material to behave as if it is in a magnetic field, even though no magnets are present, a property that scientists will want to exploit -- if they can control the mechanical strain.

To control the mechanical strain, University of Arkansas researchers developed a new experimental approach. Physicists Peng Xu, Paul Thibado and students in Thibado's group examined freestanding graphene membranes stretched over thin square "crucibles," or meshes, of copper. They performed scanning tunneling microscopy with a constant current to study the surface of the graphene membranes. This type of microscopy uses a small electron beam to create a contour map of the surface. To keep the current constant, researchers change the voltage as the scanning tunneling microscope tip moves up and down, and the researchers found that this causes the freestanding graphene membrane to change shape.

"The membrane is trying to touch the tip," Barraza-Lopez said. They discovered that the electric charge between the tip and the membrane influences the position and shape of the membrane. So by changing the tip voltage, the scientists controlled the strain on the membrane. This control becomes important for controlling the pseudo-magnetic properties of graphene.

In conjunction with the experiments, Barraza-Lopez, Yurong Yang of the University of Arkansas and Nanjing University, and Laurent Bellaiche of the University of Arkansas examined theoretical systems involving graphene membranes to better understand this new-found ability to control the strain created by the new technique. They verified the amount of strain on these theoretical systems and simulated the location of the scanning tunneling microscopy tip in relation to the membrane. While doing so, they discovered that the interaction of the membrane and tip depends upon the tip's location on the freestanding graphene. This allows scientists to calculate the pseudo-magnetic field for a given voltage and strain.

"If you know the strain, you can use theory and compute how big the pseudo-magnetic field may be," said Barraza-Lopez. They found that because of the boundaries created by the square copper crucible, the pseudo-magnetic field swings back and forth between positive and negative values, so scientists are reporting the maximum value for the field instead of a constant value.

"If you were able to make the crucibles triangular, you would be closer to having non-oscillating fields," Barraza-Lopez said. "This would bring us closer to using this pseudo-magnetic property of graphene membranes in a controlled way."

The researchers report their findings in Physical Review B Rapid Communications.

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The above story is reprinted from materials provided by University of Arkansas, Fayetteville, via Newswise.

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Home Equity Loans ? 3 Common Scams to ... - Personal Financial Tips

Home equity loans remain one of the most popular financing tools among homeowners. It can give you quick access to cash by leveraging the equity (or ownership) you have in your home. It can be an effective way to finance a home renovation, education costs, or even a second home.

But these loans also get a lot of homeowners into trouble each year, and in the worst-case scenarios they can even result in foreclosure and loss of the home. On top of that, there are some common scams associated with equity loans and lines of credit. The Federal Trade Commission (FTC) is constantly tracking the latest scams and warning homeowners about them. Here?s a summary of some of the more common scenarios you should watch out for?

1. Equity Stripping

In this scenario, the lender will actually help you ?pad? your stated income on the loan application form in order to qualify you for the loan. ?Why would they do such a thing?? you might ask. Predatory lenders use this tactic because they don?t care about your actual ability to make the payments ? they will simply foreclose on your house and benefit from the equity you?ve built up over the years.

If your income is outside of certain parameters, but the lender says ?we can make that work,? you should already be on your guard. That?s red flag #1. If they try to persuade you that you can make payments that seem out of reach, you have another warning sign. You?re the only person who should be making decisions about your ability to pay back a loan!

2. The Helpful Contractor Scam

This scenario usually starts with a home improvement contractor (such as a roofer) who knocks on the door of homeowners to offer their services. Many of the homeowners will say, ?Sorry, but that kind of project is not in our budget right now.? The contractor will counter this by saying he works with a lender who can help offset the cost. Long story short ? the homeowner signs some papers that turn out to be a home equity loan.

This scam is not as common as it once was. But it still happens on a regular basis all across America, so it?s worth mentioning in our list. Unfortunately, as with many scams, the elderly are often the target with this approach.

The first thing you need to realize is that a reputable contractor will rarely practice door-to-door marketing. That?s the first red flag. Additionally, a contractor should never refer you to a third-party lender ? it?s a conflict of interest. That?s the second red flag.

3. Loan ?Stacking? or Flipping

I refer to this scam as ?loan stacking,? because that?s what takes place. The more common term for it is ?loan flipping.? Regardless of what you call it, the scenario goes like this. The lender will offer the homeowner a second equity loan after the homeowner has already received a first one (and made a few payments on it). Basically, the lender refinances the initial loan to grant the homeowner additional money.

In some cases, this will happen more than once. And with each new round of financing, the rates typically get higher and the fees larger. The borrower now has even more money to use for whatever prompted the first equity loan ? but they also have a lot more debt spread out over a longer period of time. Homeowners who fall prey to this scam often get in over their heads with all the fees that stack up on them. It?s a good way to lose your home.

There Are Some Trustworthy Lenders

I don?t mean to scare you away from the equity loan as a source of financing. On the contrary, it can be a useful tool for a responsible borrower, and there are plenty of reputable lenders that will offer you fair terms and treatment. I?m simply trying to warn you about the common scams that go along with these types of loans.

My advice is to use a lender you?ve heard of before, a company who has been around for a long time and has a reputation at stake. Be a smart consumer when pursuing such a program. Do plenty of research and let common sense guide you.

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Sony confirms Android 4.0 update for 11 phones

April 1st, 2012 at 11:32 am - Author Blair McClelland

Last year, then Sony Ericsson and now Sony, confirmed that all 2011 Xperia smartphones will be getting an update to Android 4.0 Ice Cream Sandwich. This vital piece of information has yet to change but the update schedule for different devices has been changed up a bit.

Sony's Xperia Ray will be getting its Android 4.0 update in April alongside the Xperia Arc S and the Xperia Neo V

Sometime in the middle of April the Xperia Arc S, Xperia Neo V and Xperia Ray will get their Android 4.0 update. Then just under two months later in late May or early June the remaining 2011 Xperia range including the Xperia Arc, Play, Neo, Mini, Mini Pro, Pro, Active, and the Sony Ericsson Live with Walkman will be getting their own update.

As usual all the updates are subject to carrier certification but if you have the global, non-carrier bound version you can expect your update as soon as it starts to?roll out.

Strangely, none of the updates will be?available?OTA and will require you to plug your phone into your computer. This is because Sony wants you to make a ?conscious and informed decision to upgrade.? I?m not sure where Sony are coming from with this, I mean who wouldn?t want the latest and greatest Android operating system on their phone. To add to this users won?t even get an update notification on their Xperia phone.

Kitguru says: If Sony can stick to this update schedule it will be an impressive feat.

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Sony confirms Android 4.0 update for 11 phones, 5.0 out of 5 based on 1 rating

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Protesters march in Fla. town where teen was shot

Protestors hold up signs in a march and rally for slain Florida teenager Trayvon Martin on Saturday, March 31, 2012 in Sanford, Fla. Protesters carried signs, chanted ?Justice for Trayvon,? and clutched the hands of their children while they walked from Crooms Academy of Information Technology, the county?s first high school for black students, to the Sanford Police Department. The march was organized by the NAACP was one of several taking place over the weekend. (AP Photo/Julie Fletcher)

Protestors hold up signs in a march and rally for slain Florida teenager Trayvon Martin on Saturday, March 31, 2012 in Sanford, Fla. Protesters carried signs, chanted ?Justice for Trayvon,? and clutched the hands of their children while they walked from Crooms Academy of Information Technology, the county?s first high school for black students, to the Sanford Police Department. The march was organized by the NAACP was one of several taking place over the weekend. (AP Photo/Julie Fletcher)

Benjamin Jealous, President of the NAACP talks to the media as Rev. Al Sharpton and Rev. Jessie Jackson, back, listens before the march and rally for slain Florida teenager Trayvon Martin on Saturday, March 31, 2012 in Sanford, Fla. Protesters carried signs, chanted ?Justice for Trayvon,? and clutched the hands of their children while they walked from Crooms Academy of Information Technology, the county?s first high school for black students, to the Sanford Police Department. The march was organized by the NAACP and was one of several taking place over the weekend. Martin was shot to death by 28-year-old George Zimmerman on Feb. 26 as he walked from back from a convenience store to his father?s fianc?e?s home in a gated community outside Orlando. (AP Photo/Julie Fletcher)

Protesters hold signs during a march and rally for slain Florida teenager Trayvon Martin on Saturday, March 31, 2012 in Sanford, Fla. Protesters carried signs, chanted ?Justice for Trayvon,? and clutched the hands of their children while they walked from Crooms Academy of Information Technology, the county?s first high school for black students, to the Sanford Police Department. The march was organized by the NAACP and was one of several taking place over the weekend. Martin was shot to death by 28-year-old George Zimmerman on Feb. 26 as he walked from back from a convenience store to his father?s fianc?e?s home in a gated community outside Orlando. (AP Photo/Julie Fletcher)

From left, Rev. Jesse Jackson, Rev. Al Sharpton, and Benjamin Jealous, President of the NAACP lead the march for slain Florida teenager Trayvon Martin on Saturday, March 31, 2012 in Sanford, Fla. Protesters carried signs, chanted ?Justice for Trayvon,? and clutched the hands of their children while they walked from Crooms Academy of Information Technology, the county?s first high school for black students, to the Sanford Police Department. The march was organized by the NAACP and was one of several taking place over the weekend. Martin was shot to death by 28-year-old George Zimmerman on Feb. 26 as he walked from back from a convenience store to his father?s fianc?e?s home in a gated community outside Orlando. (AP Photo/Julie Fletcher)

SANFORD, Fla. (AP) ? Thousands joined a march Saturday through the Florida town where 17-year-old Trayvon Martin was shot and killed by a neighborhood watch volunteer, vowing to continue protesting until an arrest is made.

Protesters carried signs, chanted "Justice for Trayvon," and clutched the hands of their children while they walked to the Sanford Police Department from a local high school that served black students during the segregation era. The march was organized by the NAACP was one of several taking place over the weekend.

"We live in the middle of an American paradox," Rev. Al Sharpton told the crowd. "We can put a black man in the White House but we cannot walk a black child through a gated neighborhood. We are not selling out, bowing out or backing down until there is justice for Trayvon."

Martin was shot to death by 28-year-old George Zimmerman on Feb. 26 as he walked from a convenience store back to his father's fianc?e's home in a gated community outside Orlando. The case has stirred a national conversation about race and the laws of self-defense. Martin, a black teenager from Miami, was unarmed when he was shot by Zimmerman, whose father is white and mother is Hispanic. Zimmerman told police the teen attacked him before he shot in self-defense.

Sharpton and other civil rights leaders, including Rev. Jesse Jackson, spoke during a two-hour rally following the half-mile march.

"This is not about a hoodie, it's about racial profiling," Jackson said. "We will use our marching feet, civil disobedience and every weapon in in our non-violent arsenal until justice is served."

A dozen buses from across the state brought protesters to the rally. Shirley Roulhac-Lumpkin came with a group from Miami Gardens.

"I come from an era where people wore white hoods and nobody arrested the KKK," Roulhac-Lumpkin said. "Wearing a hoodie does not mean you're a hoodlum."

Gary Marion, a nurse who grew up in Sanford, said the Sanford police department is known "as a good ol' boy network and this incident sends a message that our children are worth nothing. I would like to see the chief of police charged with obstruction of justice."

Most of the protesters wore T-shirts with images of Trayvon Martin and many carried handmade posters with messages that read, "Hoodies Don't Kill People, Guns Kill People" and "Mother's Tears Have No Color."

"We come to make sense of this great tragedy and the entire world grieves with us," said Roslyn Brock, who chairs the national board of directors for the NAACP. "When the Sanford police did not arrest George Zimmerman, they essentially placed the burden of proof on a dead young man who cannot speak for himself."

Associated Press

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12.04.20 00:00 ORDERS - Orders - Friday April 20, 2012 @ Supreme Court of Texas

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Getting Rid of Pests with Some Efficient Pest Control Processes

Pests can unquestionably be a danger to a number of aspects if identified inside your home environment. Getting rid of pests in your home is a hard task. You need to understand the details about the right process and treatment before doing the process of pest control. Before anything, you must first understand the reasons why they invade your place. If you remove the things that support their continued existence, it will force them to find another shelter.

Pests can be found around your place. They can be in your roof, cabinets, bed, pantry, floor and in every corner. You just need to be vigilant and thorough in inspecting their possible hiding locations, as some pests are seemingly unnoticeable and are experts at hiding.

One important part of eliminating pests involves being aware of what they want and what they do not like. Understanding exactly what kind of pest is living in your home can go a long way in effective pest control. This way you will be able to know where to find them and what treatment procedure is appropriate to eliminate them. Also, understanding the habits of the pests will surely be helpful in determining how to get rid of them effectively.

Two important methods in pest control:

* Remove food and water sources- Regularly keep your premises sanitary. Be sure that the areas where food is stored and prepared are clean. Wash dirty dishes every after meal. Store your food properly in a tightly sealed container or plastic wares. Place leftovers and garbage in a covered garbage can and take it out frequently. You must also remove standing water, wet areas as it becomes a water source of pests.

* Check for crevices and openings- Eliminate or remove their probable hiding grounds. Block their access through repairing or sealing holes and crevices. Using screens on floor drains, windows and doors can be a great way in protecting your homes from pests.

Some pests can be present even in the cleanest home environment and others grow well in a filthy place. Keeping your home thoroughly clean may not completely make you get rid of pests but it can reduce the risk of infestation.

If you follow these pre-emptive measures, you can reduce the risk of having pests around your home. However if your pest infestation is already widespread and is very difficult to eradicate on your own, having the services of a pest control provider can be a practical solution.

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