Sunday, 13 November 2016

Actual living

We tend to choose the path of what
we are forced by the world to work
on.
But, you all know that we should opt
for later time the work that suits us.

Time changes everything or you may
say that everything changes with time
nothing remains as it is.

Now coming on the living beings, we
humans have got the most intellectual
brain, and this intellectuality, upon large
amount worldly concerns leads humans
to do work which is not actually suited
to them.


So, now to finalize what i am saying is
that leave everything any kind of burden,
mental pressure.
Just think of that one, self creating force,
that non existent entity, yet the one which
is controlling all, beyond time.


You may feel that no one is there, but the
force is listening you with each passing
time.

Saturday, 1 October 2016

SolidWorks: True vs Projected Dimensions

A really important part to be known by all designers on True Dimension and Projected Dimension.


Thursday, 18 August 2016

Sunshine, seaweed help to break down dye waste

Sunshine, seaweed help to break down dye waste:


The researchers developed a photocatalyst using titanium dioxide doped with red seaweed polymer carrageenan to degrade the dyes.
Scientists at the Central Salt & Marine Chemicals Research Institute (CSMCRI), Bhavanagar, Gujarat have been able to completely degrade three industrial dyes — methyl orange, methylene blue and reactive black-5 — in the presence of sunlight.
The researchers developed a photocatalyst using titanium dioxide doped with red seaweed polymer carrageenan to degrade the dyes. The results were published recently in the journal RSC Advances.
Despite stringent environmental regulations, a comprehensive method of treating industrial dye is not available. The methods available are expensive and do not completely break down the dye molecules to non-toxic constituents but merely concentrate the contaminants.
“Annually, more than 500 tonnes of non-degradable textile colour wastes are being disposed of in natural streams without adequate treatments,” the paper says.
Titanium dioxide has conventionally been used for photocatalytic degradation of industrial dyes, but it takes a long time to degrade dyes. So the researchers doped titanium dioxide nanoparticles with sulphur and carbon by treating it with carrageenan.
The nanocomposite was found to behave as an excellent photocatalyst that helped degrade industrial dyes quickly in a single-step process.
“The energy required to activate the catalyst is less when it is doped and this makes the dye degradation faster,” says Dr. Ramavatar Meena, the senior author of the paper from CSMCRI.
Solar concentrator used
Unlike a commercial titanium-dioxide-based catalyst that did not clear the dye solutions, the photocatalyst prepared in the lab was found to degrade the dyes when exposed to direct sunlight between noon and 2 pm during May-July.
“The Titanium-dioxide-doped photocatalyst degraded reactive black-5 and methylene blue in about one-and-half hours and 60 per cent of methyl orange in two hours,” says Dr. Meena. “Visible light is mainly responsible for degradation; ultraviolet radiation intensity was just 3 per cent.”
When a solar concentrator was used, the degradation process was hastened. “Reactive black-5 and methylene blue degraded within five minutes and methyl orange degraded completely in 20 minutes,” says Dr. Meena. There was no significant colour change in the case of control titanium dioxide sample that was not doped.
“When a solar concentrator is used the intensity of visible light is more and this plays an important role in the degradation process,” says Jai Prakash Chaudhary, the first author of the paper from CSMCRI.
The researchers are planning to conduct studies during winter to assess the photocatalyst’s ability to break down the dyes when bright sunlight is not available.
The nanocomposites are thermally stable and can be reused up to six times with the degradation efficiency remaining at over 97 per cent.
The nanocomposite photocatalyst can safely and completely treat harmful dyes in an eco-friendly and cost-effective manner, the study said.

Tuesday, 5 July 2016

New Nanoparticle Catalysts Improve Reactivity with Much Less Platinum

New Nanoparticle Catalysts Improve Reactivity with Much Less Platinum:

A sample of a core-shell nanoparticle made by the researchers is shown in images made using scanning transmission electron microscope (STEM) and energy-dispersive x-ray spectroscopy (EDX). Color images show where the different elements are located in the particle, with the precious metals platinum (Pt) and ruthenium (Ru) concentrated in the shell, and the other constituents, tungsten (W), and titanium (Ti), concentrated in the core.


Using an atomically-thin coating of noble metal over a tiny particle made of a much more abundant and inexpensive material, MIT engineers have developed new nanoparticle catalysts that could reduce need for precious metals.
Materials that speed up a chemical reaction without getting consumed in the process, known as catalysts, lie at the heart of many technologies, from vehicle emissions-control systems to high-tech devices such as fuel cells and electrolyzers. Unfortunately, catalysts are often pricey because they typically contain one or more noble metals, such as platinum or palladium, whose supplies are limited.
Now, researchers at MIT have found a potential end-run around this limitation: a way to get the same amount of catalytic activity with as little as one-tenth the amount of precious metal.
The key is to use an atomically-thin coating of noble metal over a tiny particle made of a much more abundant and inexpensive material: a kind of ceramic called transition metal carbide. While this idea has been the subject of extensive research, nobody had been able to find a way to get the coating to adhere to the underlying material, until now. And as a bonus, the coated particles actually outperform conventional catalysts (made completely of noble metal nanoparticles), providing greater longevity and better resistance to many unwanted phenomena that plague traditional noble metal catalysts.
The new finding is being reported this week in the journal Science, in a paper by MIT doctoral student Sean Hunt, postdocs Maria Milina and Christopher Hendon, and Associate Professor Yuriy Román-Leshkov of the Department of Chemical Engineering.
Since only the surface of catalytic particles is involved in accelerating a reaction, substituting the bulk of the particle with an inexpensive core can lead to drastic reductions in noble metal use without sacrificing performance.
MIT Researchers Develop New Nanoparticle Catalysts
A simulation of the core-shell structure shows the arrangement of the different elements as they have separated themselves into the two regions.
“For a long time, many researchers have been trying to find ways to make stable coatings of noble metals over earth-abundant cores,” Román-Leshkov says. “There has been some success using metallic cores like nickel and cobalt, but the particles are not stable over long periods of time and end up alloying with the noble metal shell.” Carbides, on the other hand, are resistant to corrosion and clustering, and also cannot alloy with noble metals, making them ideal core candidates.
But noble metals – which get their name from their general reluctance to take part in any kind of chemical activity – don’t easily bond with other materials, so producing coatings from them has been an elusive goal. At the same time, transition metal carbides are extremely difficult to engineer into nanoparticles with controlled properties. This is because they need high temperatures to force carbon into the metal lattice, which leads to particle clumping and surfaces contaminated with excess carbon layers.
The key breakthrough, Hunt says, was to encapsulate the shell and core material precursors into a template made from silica. “This keeps them close together during the heat treatment, making them self-assemble into core-shell structures, conveniently solving both challenges at the same time,” he says. The silica template could then be dissolved away using a simple room-temperature acidic treatment.
In addition to greatly reducing the amount of precious metal required, the process turned out to have other important benefits as well.
“We found that the self-assembly process is very general,” says Hunt. “The reluctance of noble metals to bind to other materials means we could self-assemble incredibly complex catalytic designs with multiple precious metal elements present in the shell and multiple inexpensive elements present in the carbide core.” This allowed the researchers to fine-tune the properties of the catalysts for different applications.
For instance, using a nanoparticle with a platinum and ruthenium shell coating a carbide core made of tungsten and titanium, they designed a highly active and stable catalyst for possible applications in direct methanol fuel cells. After the catalyst was put through 10,000 electrochemical cycles, the new design still performed 10 times better than conventional nanoparticles after similar cycling.
Yet another gain is that these nanoparticles are highly resistant to a problem that can plague other forms of noble-metal catalysts: “poisoning” of the surface by carbon monoxide. “This molecule can drastically curtail the performance of conventional catalysts by bonding to their surface and blocking further interaction, but on the core-shell catalysts, the carbon monoxide detaches more easily,” Román-Leshkov says. While traditional hydrogen fuel cell catalysts can only tolerate 10 parts per million (ppm) of carbon monoxide, the researchers found that their core-shell catalysts could tolerate up to 1,000 ppm.
Lastly, the researchers found that the core-shell structure was stable at high temperatures under various types of reaction conditions, while also remaining resistant to particle clumping. “Whereas in other classes of core-shell nanoparticles the shell dissolves into the core over time, noble metal shells are insoluble in carbide cores,” says Hunt. “This is just another one of the many benefits that ceramic cores can have in designing active and stable catalysts.”
Although work for the translation of the new concept into a commercializable form is still preliminary, in principle it could make a big difference to applications such as fuel cells, where “it would overcome one of the main limitations that fuel cells are facing right now,” Román-Leshkov says, namely the cost and availability of the needed precious metals. In fact, with the assistance of MIT’s Translational Fellows Program, Milina has been focusing on the commercial aspects of the technology, identifying the potential market, value, and customers for these novel materials.
“This is an important discovery regarding the potential applications of core-shell carbide particles coated with precious metal layers,” says Jingguang Chen, a professor of chemical engineering at Columbia University, who was not involved in this work. “It would significantly reduce the amount of precious metals needed, and it could show better catalytic performance due to the synergistic interactions between the precious metal coating and the carbide core,” he says. “Even though these advantages were predicted from previous studies of thin-film model systems, the current study demonstrates the feasibility of potential commercial applications using core shell structures.”
The research team also included Ana Alba-Rubio and James Dumesic at the University of Wisconsin at Madison. The work was supported by the U.S. Department of Energy and the National Science Foundation.
Publication: Sean T. Hunt, et al., “Self-assembly of noble metal monolayers on transition metal carbide nanoparticle catalysts,” Science 20 May 2016: Vol. 352, Issue 6288, pp. 974-978; DOI: 10.1126/science.aad8471
Source: David L. Chandler, MIT News

Monday, 4 July 2016

Google offers new way for users to manage ads, personal data

Google offers new way for users to manage ads, personal data:
Google offers new way for users to manage ads, personal data
This file image provided by Google shows a demonstration of Google's "My Account" mobile search. In 2015, Google opened a "My Account" hub to serve as a one-stop shop for setting privacy and security controls. If they choose, users will now …more
Google is trying to make it easier for you to manage the vast pool of information that it collects about your online activities across phones, computers and other devices.
Among other things, a new privacy tool will enable the more than 1 billion people who use Google's search engine and other services to block certain ads from appearing on every device that they log into, instead of having to make a special request on each individual machine.
Some users of Google's search engine, Gmail and Chrome browser will start receiving notices about the new option beginning Tuesday, but it will take several more weeks before it's available to everyone.
Google also is introducing a "My Activity" feature that will enable users to delete records of their online search requests and videos watched on YouTube in a single location instead of having to visit different websites or apps.
Google's business has been built on its longtime practice of monitoring its users' online behavior in an effort to learn about their interests so it can show ads most likely to appeal to them.
Those customized ads shown alongside Google's search results and the content on millions of other websites have turned Google's corporate parent, Alphabet Inc., into one of the world's most profitable companies.
In an effort to minimize complaints about invading people's privacy, Google has long allowed its users to impose limits on how much data is accumulated about them and how many customized ads they see.
Last year, Google also opened a "My Account" hub to serve as a one-stop shop for setting privacy and security controls.
If they choose, users will now be able to authorize Google to store their web browsing histories in the "My Account" center.
Until now, Google had been keeping personal information in different digital dossiers that sometimes require users to take multiple steps to manage specific pieces of data.
For instance, someone annoyed by a Google-generated ad on their personal computer can prevent it from appearing again by clicking on an "X'' in the corner. Taking that step currently won't block the same ad from appearing on the targeted person's smartphone a few hours later.
Google says that will no longer happen if users allow it to stockpile web browsing histories in the "My Account" center.

Facebook will automatically translate posts into different languages

Facebook will automatically translate posts into different languages:
Facebook plans to use multilingual posts to improve machine translation capabilities with the aim of one day removing language b
Facebook plans to use multilingual posts to improve machine translation capabilities with the aim of one day removing language barriers across the social network
The leading social network first made the "multilingual composer" tool available earlier this year for use on pages representing companies, brands, groups and celebrities through its Pages service.
Now it will be available to general users.
"Page authors and other people on Facebook can compose a single post in multiple languages, and the viewers who speak one of those languages will see the post in their preferred language only—allowing people to more easily interact with their diverse audiences," the company said.
Half of Facebook's more than 1.5 billion users worldwide speaks a language other than English, the California-based social network says.
Among factors Facebook will use to determine which language to use for posts include locales designated in account settings and which languages  routinely use for their posts.
The social network plans to use multilingual posts to improve machine translation capabilities with the aim of one day removing  barriers across the social network.

Sunday, 3 July 2016

Antarctic Ozone Layer Shows Signs of Healing

Antarctic Ozone Layer Shows Signs of Healing:

MIT Scientists Observe First Signs of Healing in the Antarctic Ozone Layer
A simulation of the Antarctic ozone hole, made from data taken on October 22, 2015.
New research details the “first fingerprints of healing” of the Antarctic ozone layer.
Scientists found that the September ozone hole has shrunk by more than 4 million square kilometers — about half the area of the contiguous United States — since 2000, when ozone depletion was at its peak. The team also showed for the first time that this recovery has slowed somewhat at times, due to the effects of volcanic eruptions from year to year. Overall, however, the ozone hole appears to be on a healing path.
The authors used “fingerprints” of the ozone changes with season and altitude to attribute the ozone’s recovery to the continuing decline of atmospheric chlorine originating from chlorofluorocarbons (CFCs). These chemical compounds were once emitted by dry cleaning processes, old refrigerators, and aerosols such as hairspray. In 1987, virtually every country in the world signed on to the Montreal Protocol in a concerted effort to ban the use of CFCs and repair the ozone hole.
“We can now be confident that the things we’ve done have put the planet on a path to heal,” says lead author Susan Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science at MIT. “Which is pretty good for us, isn’t it? Aren’t we amazing humans, that we did something that created a situation that we decided collectively, as a world, ‘Let’s get rid of these molecules’? We got rid of them, and now we’re seeing the planet respond.”
Solomon’s co-authors include Diane Ivy, research scientist in the Department of Earth, Atmospheric and Planetary Sciences, along with researchers at the National Center for Atmospheric Research in Boulder, Colorado, and the University of Leeds in the U.K.
Signs before spring
The ozone hole was first discovered using ground-based data that began in the 1950s. Around the mid-1980s, scientists from the British Antarctic survey noticed that the October total ozone was dropping. From then on, scientists worldwide typically tracked ozone depletion using October measurements of Antarctic ozone.
Ozone is sensitive not just to chlorine, but also to temperature and sunlight. Chlorine eats away at ozone, but only if light is present and if the atmosphere is cold enough to create polar stratospheric clouds on which chlorine chemistry can occur — a relationship that Solomon was first to characterize in 1986. Measurements have shown that ozone depletion starts each year in late August, as Antarctica emerges from its dark winter, and the hole is fully formed by early October.
Solomon and her colleagues believed they would get a clearer picture of chlorine’s effects by looking earlier in the year, at ozone levels in September, when cold winter temperatures still prevail and the ozone hole is opening up. The team showed that as the chlorine has decreased, the rate at which the hole opens up in September has slowed down.
“I think people, myself included, had been too focused on October, because that’s when the ozone hole is enormous, in its full glory,” Solomon says. “But October is also subject to the slings and arrows of other things that vary, like slight changes in meteorology. September is a better time to look because chlorine chemistry is firmly in control of the rate at which the hole forms at that time of year.  That point hasn’t really been made strongly in the past.”
A healing trend
The researchers tracked the yearly opening of the Antarctic ozone hole in the month of September, from 2000 to 2015. They analyzed ozone measurements taken from weather balloons and satellites, as well as satellite measurements of sulfur dioxide emitted by volcanoes, which can also enhance ozone depletion. And, they tracked meteorological changes, such as temperature and wind, which can shift the ozone hole back and forth.
They then compared their yearly September ozone measurements with model simulations that predict ozone levels based on the amount of chlorine that scientists have estimated to be present in the atmosphere from year to year. The researchers found that the ozone hole has declined compared to its peak size in 2000, shrinking by more than 4 million square kilometers by 2015. They further found that this decline matched the model’s predictions, and that more than half the shrinkage was due solely to the reduction in atmospheric chlorine.
“It’s been interesting to think about this in a different month, and looking in September was a novel way,” Ivy says. “It showed we can actually see a chemical fingerprint, which is sensitive to the levels of chlorine, finally emerging as a sign of recovery.”
The team did observe an important outlier in the trend: In 2015, the ozone hole reached a record size, despite the fact that atmospheric chlorine continued to drop. In response, scientists had questioned whether any healing could be determined. Going through the data, however, Solomon and her colleagues realized that the 2015 spike in ozone depletion was due primarily to the eruption of the Chilean volcano Calbuco. Volcanoes don’t inject significant chlorine into the stratosphere but they do increase small particles, which increase the amount of polar stratospheric clouds with which the human-made chlorine reacts.
“Why I like this paper so much is, nature threw us a curveball in 2015,” says Ross Salawitch, professor of chemistry and biochemistry at the University of Maryland. “People thought we set a record for the depth of the ozone hole in October 2015. The Solomon paper explains it was due to a specific volcanic eruption. So without this paper, if all we had was the data, we would be scratching our heads — what was going on in 2015?”
As chlorine levels continue to dissipate from the atmosphere, Solomon sees no reason why, barring future volcanic eruptions, the ozone hole shouldn’t shrink and eventually close permanently by midcentury.
“What’s exciting for me personally is, this brings so much of my own work over 30 years full circle,” says Solomon, whose research into chlorine and ozone spurred the Montreal Protocol. “Science was helpful in showing the path, diplomats and countries and industry were incredibly able in charting a pathway out of these molecules, and now we’ve actually seen the planet starting to get better. It’s a wonderful thing.”
This research was supported, in part, by the National Science Foundation and the U.S. Department of Energy.
Publication: Susan Solomon, et al., “Emergence of healing in the Antarctic ozone layer,” Science, 30 Jun 2016; DOI: 10.1126/science.aae0061
Source: Jennifer Chu, MIT News