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 Solar Nanowire-Nanotube Purification Filter Offers Easy Access To Clean Drinking WaterEven today, c

Solar Nanowire-Nanotube Purification Filter Offers Easy Access To Clean Drinking Water

Even today, clean water is a privilege for many people across the world. According to the World Health Organization (WHO), at least 1.8 billion people consume water contaminated with feces, and by 2040, a large portion of the world will endure water stress because of insufficient resources of drinking water. Meanwhile, the United Nations Children’s Fund (UNICEF), around 1,800 children die every day from diarrhea because of unsafe water supply, which causes diseases like cholera.

It has become imperative then that we develop efficient and cost-efficient ways to decontaminate water. And that is exactly what a team of scientists led by László Forró at EPFL have accomplished, with a new water purification filter that combines titanium dioxide (TiO2) nanowires and carbon nanotubes powered by nothing but sunlight.

The scientists first show that the TiO2nanowires by themselves can efficiently purify water in the presence of sunlight. But interweaving the nanowires with carbon nanotubes forms a composite material that adds an extra layer of decontamination by pasteurizing the water – killing off human pathogens such as bacteria and large viruses.

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entp-adviceorbust: neuro-genesis: koolaid-mami: scienceyoucanlove: This door handle kills germsUV lientp-adviceorbust: neuro-genesis: koolaid-mami: scienceyoucanlove: This door handle kills germsUV li

entp-adviceorbust:

neuro-genesis:

koolaid-mami:

scienceyoucanlove:

This door handle kills germs

UV light, powered by the door’s movement, triggers the microbe-killing power of the handle’s coating

BY

SID PERKINS

PITTSBURGH, Pa. — Diseases spread in many ways. An infected person can cough or sneeze on someone nearby. Or, they can transfer germs through a handshake. But sometimes we pick up germs indirectly. A sick person might leave behind bacteria or viruses when they touch a doorknob, handrail, shopping cart handle or countertop. Anyone else who touches that surface may pick up the microbes. But what if those surfaces could disinfect themselves?

Two teens from Hong Kong asked themselves the same question. Now they’ve developed a door handle that can knock out germs on contact.

The concept is simple. Every time the door is opened, the movement creates power that triggers a germ-killing reaction on the handle. In lab tests, their system killed about 99.8 percent of the germs that they spread onto lab dishes coated with their material.

Research by others has shown that door handles in public areas often host lots of bacteria and viruses, notes 17-year-old Sum Ming (“Simon”) Wong. The tenth grader attends Church of Christ in China Tam Lee Lai Fun Memorial Secondary School in Tuen Mun, China. He and schoolmate Kin Pong (“Michael”) Li, 18, wanted to design a coating for door handles that would be hostile to germs.

After doing some research, they learned that a mineral called titanium dioxide is known to kill bacteria. It’s already used for other purposes in many products, from paints to sunscreens to edible puddings. To make their coating, the teens ground the mineral into a very fine powder.

Titanium dioxide kills bacteria best when lit by ultraviolet (UV) light, says Simon. UV wavelengths are among those in sunlight. But indoor handles and any used at night would have little natural exposure to UV light. So the teens are lighting their door handle from within. Now, every part of the coated handle will see UV light.

To make sure the interior light reaches the coated surface, the teens fashioned their door handle from a long cylinder of clear glass. Each end fits into a bracket. Inside one of the brackets is a strong light-emitting diode (LED). It emits UV light. (Transmitting the light from one end of the handle to the other is similar to the transmission of light through a fiber-optic cable. In this case, though, the glass handle is fat rather than super-thin.)

And here’s the nifty part: The power that makes the UV light shine comes from opening and closing the door. Simon and Michael designed a small gearbox that attaches to the door. Equipment inside the box converts the motion of those gears into electrical power. That power is then carried by wire to the light-emitting diode inside the door handle.

The teens presented details of their research here at the Intel International Science and Engineering Fair. This event was created by the Society for Science and the Public (which also publishes Science News for Students). The annual competition is sponsored by Intel. This year, it brought 1,702 finalists to Pittsburgh in mid-May from more than 70 countries.

The door handle system, Michael and Simon say, might cost no more than about $13 to build.

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I love this!! Love!!

i’m a germaphobe & i need this

Want


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 Researchers discover new photoactivation mechanism for polymer productionA team of researchers from

Researchers discover new photoactivation mechanism for polymer production

A team of researchers from North Carolina State University has demonstrated a way to use low-energy, visible light to produce polymer gel objects from pure monomer solutions. The work not only poses a potential solution to current challenges in producing these materials, it also sheds further light on the ways in which low energy photons can combine to produce high energy excited states.

Polymer products—primarily plastics—are used in everything from water bottles to medical applications, with billions of pounds of these materials being produced annually. Select polymers can be produced via a process called free radical polymerization, in which a monomer solution is exposed to ultraviolet (UV) light. The high energy of UV light enables the reaction, forming the polymer. The advantages of this method include fewer chemical waste byproducts and less environmental impact.

However, this method is not without drawbacks. The high energy UV light used in generating these polymers can also degrade plastics and is unsuitable for producing certain materials.

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Young blue stars circling the galactic center dominate the Andromeda Galaxy in this image taken in ultraviolet! About 2.5 million light-years away, the Andromeda Galaxy, also known as M31, really is our galactic neighbour. Spanning about 230,000 light-years, it took 11 different image fields from NASA’s Galaxy Evolution Explorer (GALEX) satellite telescope to produce this gorgeous portrait of the spiral galaxy in ultraviolet light in 2003. Its spiral arms stand out in visible light images, Andromeda’s arms are sites of intense star formation. They have been interpreted as evidence that Andromeda collided with its smaller neighboring elliptical galaxy M32 more than 200 million years ago. The Andromeda galaxy and our own comparable Milky Way galaxy are the most massive members of the Local Group of galaxies and are projected to collide in several billion years – perhaps around the time that our Sun’s atmosphere will expand to engulf the Earth.

Image Credit: NASA, JPL-Caltech, GALEX

This may be weird for most of you but back in Soviet union kids who lived in in northern territories

This may be weird for most of you but back in Soviet union kids who lived in in northern territories had to do this UV light thing. Supposedly it gives your body extra vitamins that helps your immune system to survive harsh winters.


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Fluorescent vermillion Corundum var ruby (Al2O3) in schist matrix under long frequency UV light. Fro

Fluorescent vermillion Corundum var ruby (Al2O3) in schist matrix under long frequency UV light. From Mysore corundum deposits, Karnataka, India


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hyperallergic: Sometimes you think you have a handle on an artist’s work, and then a new piece of in

hyperallergic:

Sometimes you think you have a handle on an artist’s work, and then a new piece of information comes along that casts it in an entirely different light. In the case of Judith Bernstein, whose paintings are now on view at Mary Boone, a moment of reflection by the artist can shift a set of motifs from the insatiably primal to the acutely personal.

Into the Abyss: Judith Bernstein’s Dissection of Desire


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Bananas are one of the most popular fruits in the world. Love them or hate them, most of us know what they look like. Despite their global presence, few stop to think about where these fruits come from. That is a shame because bananas are fascinating plants for many reasons but now we can add blue fluorescence to that list.

Before we dive into the intriguing phenomenon of fluorescence in bananas, I think it is worth talking about the plants that produce them in a little more detail. Bananas belong to the genus Musa, which is located in its own family - Musaceae. Take a step back and look at a banana plant and it won’t take long to realize they are distant relatives of the gingers. There are at least 68 recognized species of banana in the world and many more cultivated varieties. Despite their pan-tropical distribution, the genus Musa is native only to parts of the Indo-Malesian, Asian, and Australian tropics.



Banana plants vary in height from species to species. At the smaller end of the spectrum you have species like the diminutive Musa velutina, which maxes out at about 2 meters (6 ft.) in height. On the taller side of things, there are species such as the monstrous Musa ingens, which can reach heights of 20 meters (66ft.)! Despite their arborescent appearance, bananas are not trees at all. They do not produce any wood. Instead, what looks like a tree trunk is actually the fused petioles of their leaves. Bananas are essentially giant herbs with the aforementioned M. ingens holding the world record for largest herb in the world.

When it comes time to flower, a long spike emerges from the main growing tip. This spike gradually elongates, revealing long, beautiful, tubular flowers arranged in whorls. For many banana species, bats are the main pollinators, however, a variety of insects will visit as well. In the wild, fruits appear following pollination, a trait that has been bred out of their cultivated relatives, which produce fruits without needing pollination. The fruits of a banana are actually a type a berry that dehisce like a capsule upon ripening, revealing delicious pulp chock full of hard seeds. Not all bananas turn yellow upon ripening. In fact, some are pink!



For many fruits, the act of ripening often coincides with a change in color. This is a way for the plant to signal to seed dispersers that the fruits, and the seeds inside, are ready. As many of us know, many bananas start off green and gradually ripen to a bright yellow. This process involves a gradual breakdown of the chlorophyll within the banana skin. As the chlorophyll within the skin of a banana breaks down, it leaves behind a handful of byproducts. It turns out, some of these byproducts fluoresce blue under UV light. 

Amazingly, the fluorescent properties of bananas was only recently discovered. Researchers studying chlorophyll breakdown in the skins of various fruits identified some intriguing compounds in the skins of ripe Cavendish bananas. When viewed under UV light, these compounds gave off a luminescent blue hue. Further investigation revealed that as bananas ripen, their fluorescent properties grow more and more intense.



There could be a couple reasons why this happens. First, it could simply be happenstance. Perhaps these fluorescent compounds are simply a curious byproduct of chlorophyll breakdown and serve no function for the plant whatsoever. However, bananas seem to be a special case. The way in which chlorophyll in the skin of a banana breaks down is quite different than the process of chlorophyll breakdown in other plants. What’s more, the abundance of these compounds in the banana skin seems to suggest that the fluorescence does indeed have a function - seed dispersal.

Researchers now believe that the fluorescent properties of some ripe bananas serves as an additional signal to potential seed dispersers that the time is right for harvest. Many animals including birds and some mammals can see well into the UV spectrum and it is likely that the blue fluorescence of these bananas is a means of attracting such animals. Additionally, researchers also found that banana leaves fluoresce in a similar way, perhaps to sweeten the attractive display of the ripening fruits.

To date, little follow up has been done on fluorescence in bananas. It is likely that far more banana species exhibit this trait. Certainly more work is needed before we can say for sure what role, if any, these compounds play in the lives of wild bananas. Until then, this could be a fun trait to investigate in the comfort of your own home. Grab a black light and see if your bananas glow blue!

Photo Credits: [1][2][3][4]

Further Reading: [1][2]

Сцинтилляторы и ультрафиолетовое излучение.

Сцинтилляторы и ультрафиолетовое излучение.


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 Anycubic LighTurbo Light Source: Fast, Accurate Desktop Resin Printing(Photos taken safely!)

Anycubic LighTurbo Light Source: Fast, Accurate Desktop Resin Printing

(Photos taken safely!)


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Scapolite with Diopside displaying fluorescenceLocality: Grenville Scapolite Prospect, Grenville-surScapolite with Diopside displaying fluorescenceLocality: Grenville Scapolite Prospect, Grenville-sur

Scapolite with Diopside displaying fluorescence

Locality: Grenville Scapolite Prospect, Grenville-sur-la-Rouge, Laurentides, Québec, Canada

375 nm (Longwave) UV Light


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Sodalite var. Hackmanite with Richterite displaying fluorescence and tenebrescenceLocality: Koksha VSodalite var. Hackmanite with Richterite displaying fluorescence and tenebrescenceLocality: Koksha VSodalite var. Hackmanite with Richterite displaying fluorescence and tenebrescenceLocality: Koksha V

Sodalite var. Hackmanite with Richterite displaying fluorescence and tenebrescence

Locality: Koksha Valley, Badakhschan Province, Afghanistan

375 nm (Longwave) UV Light


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Ussingite with Sodalite var. Hackmanite displaying fluorescenceLocality: Greenland 375nm (Longwave) Ussingite with Sodalite var. Hackmanite displaying fluorescenceLocality: Greenland 375nm (Longwave)

Ussingite with Sodalite var. Hackmanite displaying fluorescence

Locality: Greenland

375nm (Longwave) UV Light


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Aragonite on Calcite displaying fluorescenceLocality: Unknown 375nm (Longwave) UV Light Aragonite on Calcite displaying fluorescenceLocality: Unknown 375nm (Longwave) UV Light Aragonite on Calcite displaying fluorescenceLocality: Unknown 375nm (Longwave) UV Light

Aragonite on Calcite displaying fluorescence

Locality: Unknown

375nm (Longwave) UV Light


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Gypsum var. “Golden” Selenite displaying fluorescenceLocality: Unknown 375 nm (Longwave) UV Light Gypsum var. “Golden” Selenite displaying fluorescenceLocality: Unknown 375 nm (Longwave) UV Light Gypsum var. “Golden” Selenite displaying fluorescenceLocality: Unknown 375 nm (Longwave) UV Light

Gypsum var. “Golden” Selenite displaying fluorescence

Locality: Unknown

375 nm (Longwave) UV Light


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Afghanite partially replaced by Lapis Lazuli displaying fluorescenceLocality: Ladjuar Madan, Kokcha Afghanite partially replaced by Lapis Lazuli displaying fluorescenceLocality: Ladjuar Madan, Kokcha Afghanite partially replaced by Lapis Lazuli displaying fluorescenceLocality: Ladjuar Madan, Kokcha Afghanite partially replaced by Lapis Lazuli displaying fluorescenceLocality: Ladjuar Madan, Kokcha

Afghanite partially replaced by Lapis Lazuli displaying fluorescence

Locality: Ladjuar Madan, Kokcha Valley, Badakhshan, Afghanistan

375 nm (Longwave) UV Light


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Zircon on Syenite displaying fluorescenceLocality: Stokkøya, Langesundsfjorden, Larvik, Vestfold og Zircon on Syenite displaying fluorescenceLocality: Stokkøya, Langesundsfjorden, Larvik, Vestfold og

Zircon on Syenite displaying fluorescence

Locality: Stokkøya, Langesundsfjorden, Larvik, Vestfold og Telemark, Norway

254 nm (Shortwave) UV Light


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Exactly a year back on this very day, we explored how polarized sunglasses work and why Pilots prefer NOT to use them.

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What about those with power prescriptions you ask ?

These days you can find a lot of people even with power prescriptions sporting glasses/lenses that turn dark when exposed to sunlight. These are known as Photochromic lenses. 


Let’s do a quick demo:

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This is a photochromic lens getting exposed to 395-400 nm light turning dark as a result.

(Better quality video here)


How does it do that ?

To learn how this is achieved it must be understood that there are these class of reactions called ‘Reversible reactions’

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A and B can react to form C and D or, in the reverse reaction, C and D can react to form A and B. 

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                    Example of reversible reaction of Bismuth Chloride

In the case of Bismuth Chloride, sunlight acts as a mediator to change it from a transparent solution to a dark colored solution and shaking in air brings it back.


In the case of Photochromic lenses, an organic dye is used that darkens under UV and lightens under its absence

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                                                  Source                              


Alternate reality: Photo-degradation

If you ever have had the unfortunate experience of leaving your plastic in the sun or wondered why the colors of your clothes fade away, then the technical term to express your misery is Photo-degradation.

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This is the other extreme of a reversible reaction where UV light from the sun break break down the chemical bonds in the plastic and clothes (called chromophores) and eventually leads to fading of the colors in the object


The catch

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As any user of one of these Photochromic lenses will tell you, there are some aspects of these lenses that still need to be improved

-  The chemical reaction rate depends on the temperature of the surrounding. This means that on a sunny day if you are in a really warm climate, the lenses will adapt faster than if you live in a cold climate

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- Most car windshields block UV light to some extent and therefore these lenses are not effective when you are inside the car.

- They do degrade after a while. Most of lenses do degrade having been used after a couple of years and need to be changed.

But having said that Photochromic lens are indeed a really cool piece of technology.

Have a great day!

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