terça-feira, 5 de maio de 2015
“Microcombing” creates stronger, more conductive carbon nanotube films
| Tue, 05/05/2015 Matt Shipman, News Services, North Carolina State University Researchers from North Carolina State Univ. and China’s Suzhou Institute of Nano-Science and Nano-Biotics have developed an inexpensive technique called “microcombing” to align carbon nanotubes (CNTs), which can be used to create large, pure CNT films that are stronger than any previous such films. The technique also improves the electrical conductivity that makes these films attractive for use in electronic and aerospace applications. “It’s a simple process and can create a lightweight CNT film, or ‘bucky paper,’ that is a meter wide and twice as strong as previous such films—it’s even stronger than CNT fibers,” says Yuntian Zhu, Distinguished Professor of Materials Science and Engineering at NC State and corresponding author of a paper describing the work. The researchers begin by growing the CNTs on a conventional substrate in a closely packed array. The CNTs are tangled together, so when researchers pull on one end of the array the CNTs form a continuous ribbon that is only nanometers thick. This ribbon is attached to a spool, which begins winding the ribbon up. As the spool pulls, the CNT ribbon is dragged between two surgical blades. While the blades appear straight to the naked eye, they actually have micrometer-scale fissures on their cutting edge. These fissures create a kind of “microcomb” that pulls the CNTs into alignment—just as a regular comb sorts through tangled hair. When the ribbon of aligned CNTs is being wound onto the spool, the researchers apply an alcohol solution. This pulls the CNTs closer together, strengthening the bonds between CNTs. The CNT ribbon wraps around itself as it winds around the spool, creating a layered film of pure CNTs. Researchers can control the thickness of the film by controlling the number of layers. The CNT films made using the microcombing technique had more than twice the tensile strength of the uncombed CNT films—greater than 3 gigapascals for the microcombed material, versus less than 1.5 gigapascals for the uncombed material. The microcombed CNT film also had 80% higher electrical conductivity than the uncombed film. “This is a significant advance, but we want to find ways to make CNT alignment even straighter,” Zhu says. “It’s still not perfect. “In addition, the technique would theoretically be easy to scale up for large-scale production. We’d like to find an industry partner to help us scale this up and create a material for the marketplace.” The paper is published online in Small. Source: North Carolina State University
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Construa-se
Ninguém Se Conhece a Si Mesmo
Julga que se conhece, se não se construir de algum modo? E julga que eu posso conhecê-lo, se não o construir à minha maneira? E julga que me pode conhecer, se não me construir à sua maneira? Só podemos conhecer aquilo a que conseguimos dar forma. Mas que conhecimento pode ser esse? Não será essa forma a própria coisa? Sim, tanto para mim como para si; mas não da mesma maneira para mim e para si: isso é tão verdade que eu não me reconheço na forma que você me dá, nem você se reconhece na forma que eu lhe dou; e a mesma coisa não é igual para todos e mesmo para cada um de nós pode mudar constantemente. E, contudo, não há outra realidade fora desta, a não ser na forma momentânea que conseguimos dar a nós mesmos, aos outros e às coisas. A realidade que eu tenho para si está na forma que você me dá; mas é realidade para si, não é para mim. E, para mim mesmo, eu não tenho outra realidade senão na forma que consigo dar a mim próprio. Como? Construindo-me, precisamente.
Texto de Luigi Pirandello, in "Um, Ninguém e Cem Mil"
10 useful Google Search functions you may not know about
There are a host of commands and functions that can be used with Google Search to get more out of the popular search engine
Google Search is so widely used that the company's name has become synonymous with searching online. There's more to the most used search engine in the world than just locating websites though, other services aside. Let's have a look at some of Google Search's other functions.
Search content from a specific website
Many people will already know that you can use Google Search to look for websites, but it can also be used to search for certain terms on specific websites. This can be done using the "site:" command.
For example, if you want to find all mentions of UK designer and architect Thomas Heatherwick on Gizmag, you need only enter "thomas heatherwick site:www.gizmag.com" in the search box. In a similar way, it's also possible to search a specific news outlet on Google News using the "source:" command.
Search with missing letters or words
Sometimes you may know what you want to search for, but may not be able to remember the exact word or phrase. Believe it or not, there is a solution to help with this. Google Search uses the asterisk as a wildcard, meaning you can substitute any word or letter for an asterisk and results containing all of the possible alternatives that the asterisk could stand for will be returned. For example, searching for "an * a day" will bring up results that include "an hour a day," "an apple a day," and "an aspirin a day."
Find similar websites
If there's a website or service you can't get enough of, or to which you need something slightly different, then you can use the "related:" command to find sites or services that are similar to it.
For example, if you're looking for alternatives to Spotify, then you can search for "related:www.spotify.com" and Google Search will provide a host of similar services and related pages.
Find definitions
If you're unsure of a word's meaning, there's no need to go searching for an online dictionary. The search engine can provide definitions itself. All that's needed is to precede the word about which you're curious with the command "define:". For example, if the meaning of "pneumonoultramicroscopicsilicovolcanoconiosis" has escaped you, then searching for "define: pneumonoultramicroscopicsilicovolcanoconiosis" will reveal all.
Calculate conversions
Google Search is able to convert many different units of measure. To make matters easier, it is also able to do so based on natural language. So, for example, you need only type in "10.5 centimeters in inches" and you'll be provided with the converted figure. Abbreviations will also work and the search engine also recognizes code conventions, such as for currency.
To find out how many pounds sterling your dollars are worth, therefore, you can search for "15 USD in GBP." Other units of measure that Google Search recognizes include temperature, area and power, as well as things like height and weight.
Calculate sums
You can use Google Search to work out math calculations. It's just a case of typing your sum into the search box and pressing enter. A simple example would be "10 + 20" which, of course, will give you an answer of 30. But Google Search is far more sophisticated than that and is able to handle parenthesized calculations, advanced math and physical constants.
Check flights
If you're planning to meet someone at the airport, or you just want to check that they have landed safely, you can now find flight information directly through Google Search. You need only search for the airline and the flight number to bring up the required information. Searching for "qantas QF7" will bring up information about a Qantas flight on the world's longest route, for example. In a similar way, it's also possible to track courier packages with the tracking number.
Check for movie showtimes
When you're looking for a movie to go and see at the cinema, Google Search can help you decide what to watch, where and when. Searching alone for "showtimes" will bring up cinema listings for your country or, if you provide more specific location information, your area. If you want to know when a specific film is showing, then "showtimes:" followed by the film name will bring up just the listings for that film (such as "showtimes: gone girl").
Find out world times
You may already know that you can check the time in different cities around the world using Google Search. The command "time:" along with the city in question is all you need. "Time: Sydney" will give you the time in Sydney, Australia. Fewer people may know that you can also search for the time across entire areas though. A search for "time: africa" will provide a range of times from cities across the continent.
Do a barrel roll
And, of course, if you want your search results to do a barrel roll, then all you need to do is ask and Google Search will oblige. Type "do a barrel roll" into the box and hit search. Why wouldn't you?
For more advice on getting more out of Google services, you can hit up Gizmag's Google Chrome tips and our tips for getting the most out of Gmail.
Canção do Mar Aberto
Canção do Mar Aberto
Onde puseram teus olhos
A mágoa do teu olhar?
Na curva larga dos montes
Ou na planura do mar?
De dia vivi este anseio;
De noite vem o luar,
Deixa uma estrada de prata
Aberta para eu passar.
Caminho por sobre as ondas
Não paro de caminhar.
O longe é sempre mais longe…
Ai de mim se me cansar!...
Morre o meu sonho comigo,
Sem te poder encontrar..
Armando Côrtes-Rodrigues, in 'Planície Inquieta'
Have You Been Drinking Enough Water? This Might Make You Pick Up A Glass.
Last year, I realized I was chronically dehydrated.
I didn’t even realize it until I took a moment to read about proper hydration. I barely drank any water!
Now I drink upwards of a gallon of water a day. My body just works better.
I feel better. I feel stronger, better rested, sharper; just overall less awful. Are you drinking enough water?
How our view of what makes us happy has changed in 80 years
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How have our views of happiness changed in the last 80 years, and how have they stayed the same? Credit: © lenayarmolik / Fotolia Our view of what makes us happy has changed markedly since 1938. That is the conclusion of the psychologist Sandie McHugh from the Univeristy of Bolton who has recreated a famous study of happiness conducted in Bolton in 1938. She will present her study today, Tuesday 5 May 2015, to the Annual Conference of the British Psychological Society in Liverpool. In 1938 Mass Observation placed an advertisement in the the Bolton Evening News asking readers to answer the question 'What is happiness?'. A total of 226 people sent letters in reply, and they were asked to help compile a happiness index by rating the importance of ten factors ranging from beauty to more security and religion. In 2014 Sandie McHugh and Professor Jerome Carson repeated the Mass Observation survey by asking people from the town, via the Bolton News, to complete a questionnaire that repeated the questions from 1938 as closely was possible. She then compared the new findings with those from 1938. Sandie McHugh found that in 1938 security, knowledge and religion were seen by participants as being the three most important aspects of happiness. In 2014 security was still in the top three, but good humour and leisure were in first and second places. Religion, which was seen as the third most important factor in 1938, had fallen to tenth (and bottom) place in 1938. Another striking difference is that in 1938 the majority of people said they were happiest when they were in Bolton, but in 2014 63 per cent said they were happier away from the town. When it comes to luck, in 1938 and in 2014, 40 per cent of people believed it was important to happiness. In 2014, 77 per cent answered "No" to the question "Do you think your happiness is directly linked to material possessions and wealth?." Although security had been highly rated in 1938, wealth by itself was not. Sandie McHugh said: "The overall impression from the correspondence in 1938 is that happiness factors were rooted in everyday lives at home and within the community. In 2014 many comments value family and friends, with good humour and leisure time also ranked highly." Quotations on happiness from the 1938 and 2014 surveys "Enough money to meet everyday needs and a little for pleasure." (1938) "Knowing that my rent is paid on time and I can afford to eat healthily." (2014) "I would like a little home, not many possessions … congenial and satisfying companionship, the availability of good music and books." (1938) "Engaging in my hobbies, spending time that is free of worry … Simple things like enjoying a nice meal or receiving care and affection." (2014) "When I come home from the pit and see my kiddies and wife, I am happy." (1938) "Simple things like going out for a walk…….you don't need tons of material things to be happy, you just have to be happy in the place you live and with the people around you." (2014) Story Source: The above story is based on materials provided by British Psychological Society (BPS). Note: Materials may be edited for content and length.
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