| Photonics & laser colaterale (335) |  |
| Photonics & laser generale (106) | |
| Photonics & laser tendinte (8) | |
The basic concept is to equip drug molecules with chemical components that change shape in response to heat or light.
Organic chemist Ben Feringa at Groningen and his co-workers used an existing light-switchable unit called azobenzene,
If the Z-shaped isomer absorbs ultraviolet light, it will become switch to the C-shaped isomer.
The reverse shape change can be induced by visible light or gentle heating at around body temperature. Feringa and colleagues substituted the azobenzene switch for a similar chemical grouping within several variants of an antibacterial molecule called a quinolone,
Or at least they were after exposure to ultraviolet light made them switch to the C-isomer.
and then turned on with light once they reach the part of the body (the throat or lungs, say) where the harmful bacteria are lurking.
Switching on drugs with ultraviolet light is not ideal in practice because it can have harmful effects.
Feringa says he is now working on developing molecules than can be shifted shape with visible light, or better still infrared,
and artificial light conditions and even shaded areas. Solarwindow#uses organic materials, which are dissolved into liquid, ideal for low-cost high-output manufacturing.
A light on the instrument panel indicates when CNG is being used and there is no interruption in the vehicle performance.
The device uses a thumbnail-sized quantum cascade laser (QCL) as well as tuning forks that cost no more than a dime to detect very small amounts of nitrous oxide and methane.
That allows for far better detection of gases than more common lasers that operate in the near-infrared.
The technique called uartz-enhanced photoacoustic absorption spectroscopy (QEPAS invented at Rice university in 2002 by engineer Frank Tittel, Professor Robert Curl,
and is far better able to detect trace amounts of gas than lasers used in the past.
The laser beam is focused between the two prongs of the quartz tuning fork. When light at a specific wavelength is absorbed by the gas of interest
localized heating of the molecules leads to a temperature and pressure increase in the gas. f the incident light intensity is modulated,
then the temperature and pressure will be as well, Ren says. his generates an acoustic wave with the same frequency as the light modulation,
using concentrated light as a high-temperature energy source. The project is still at the experimental stage,
The process In a first step concentrated light-simulating sunlight-was used to convert carbon dioxide and water to synthesis gas (syngas) in a high-temperature solar reactor containing metal-oxide based materials developed at ETH Zürich.
Using a standard laser printer stocked with special wax-based inks he printed patterns of small dots onto uncoated filter paper.
and flexible electronic devices to harvest solar energysays Luyao Lu a graduate student in chemistry and lead author of a paper in the journal Nature Photonics that describes the result.
The standard mechanism for improving efficiency with a third polymer is by increasing the absorption of light in the device.
and the Advanced Light source at Lawrence Berkeley. ithout that it s hard to get insight about the structureyu says. hat benefits us tremendously. his knowledge will serve as a foundation from
and Technology Canadian Light source Inc. and University of Tennessee contributed to the study. Principal funding came from by the Global climate and Energy project the Precourt Institute for Energy at Stanford and by the US Department of energy.
and his team to absorb specific nonvisible wavelengths of sunlight. e can tune these materials to pick up just the ultraviolet
and the near infrared wavelengths that then glow at another wavelength in the infraredhe says.
The device uses a thumbnail-sized quantum cascade laser (QCL) as well as tuning forks that cost no more than a dime to detect very small amounts of nitrous oxide and methane.
That allows for far better detection of gases than more common lasers that operate in the near-infrared.
The technique called uartz-enhanced photoacoustic absorption spectroscopy (QEPAS invented at Rice university in 2002 by engineer Frank Tittel, Professor Robert Curl,
and is far better able to detect trace amounts of gas than lasers used in the past.
The laser beam is focused between the two prongs of the quartz tuning fork. When light at a specific wavelength is absorbed by the gas of interest
localized heating of the molecules leads to a temperature and pressure increase in the gas. f the incident light intensity is modulated,
then the temperature and pressure will be as well, Ren says. his generates an acoustic wave with the same frequency as the light modulation,
The nanoparticle is fluorescent in visible light and the nanotubes are fluorescent in the near-infrared.
and docks with the teats using a 3d camera and lasers. Another feature is a set of counter-rotating brushes that automatically clean the teats of dirt
The breakthrough is in the new system's ability to bind titanium dioxide (Tio2) a photocatalyst that reacts under ultraviolet light.
#New LED light technology sheds light on the future of food LED growing lights, delivering sunlight whatever the weather.
We need to make better use of land, light and logistics for an increasingly urban population.
or grow indoors with the help of artificial lights. Vertical farming is promising because it requires no soil,
and environmental controls that regulate temperature, humidity and light to produce vegetables, fruits and other crops year-round.
Considerable energy is required to power a closed, indoor greenhouse facility s artificial lighting, heating and cooling
This kind of artificial light has an extremely high photoelectric conversion efficiency consuming only one eighth the power of incandescent lamp, half of the power of fluorescent lamp,
and can produce light of varying intensity. Because it produces less heat, the light can be moved closer to the plants.
This increases efficiency, not just in terms of energy use but by allowing layers of growing plants to be packed more densely, making more efficient use of space.
LED LIGHTS can be tuned to emit only a narrow wavelength of light they can be combined to create perfect lighting that provide light on the ideal spectrum for a plant s growth.
Evidence is emerging that specific wavelengths of light have distinct effects on crop yield, quality, and even pest and disease resistance.
There is potential for these multifunctional techno-greenhouses built around LED grow lights to increase the quality of the food we eat
and the amount that we can grow with the same land and resources: the very 21st-century problems we now face
Itl include optimized lights set to a wavelength to grow perfect plants and specialized air-conditioning that keeps temperature and humidity set to a constant level.
by using infrared light). Scientifically viable in 2015; mainstream in 2018; and financially viable in 2019.
vertical farms could augment natural light using energy-efficient lighting. The advantages are numerous, including year-round crop production, protection from weather, support urban food autonomy and reduced transport costs.
It based on near-infrared spectroscopy, which means it reflects light onto an object, then collects and analyzes the light reflected back.
The Kickstarter launched Tuesday morning with several funding levels: a fully operational SCIO starts at $149,
While scientists and researchers use near-infrared spectroscopy on a regular basis, there are lots of consumers that would love to know more about the chemical composition of the world around them,
shine its blue light onto an object you want to analyze. In a few seconds, the associated smartphone app will take the spectrometer reading,
#New 3d printed materials lighter than water and as strong as steel A Nanoscribe 3d printer can print models of the Empire state building in a space the width of a human hair using precision lasers.
The printer s mirror-focused laser shines on and hardens a droplet of liquid plastic on a slide.
A computer moves the plate under the laser, selectively hardening it, layer by layer, to match a digital 3d model.
For instance, amber hallway lights are bright enough for occupants to navigate the corridor, but not disruptive of the human eye production of rhodopsin (which helps us see in darkness,
Blue light during the day helps maintain alertness. The home also features a passive design that maximizes heating
and cooling (the south-facing windows) and natural light and ventilation (the north-facing windows). The property is also five times more water-efficient than the normal house, with low-flow fixtures and short-run hot-water pipes.
because light and oxygen damage the photosynthetic proteins. Usually plants can completely repair this kind of damage,
and other highly reactive molecules produced by light and oxygen, protecting the chloroplasts from damage.
but carbon nanotubes could act as artificial antennae that allow chloroplasts to capture wavelengths of light not in their normal range, such as ultraviolet, green,
and ultraviolet (UV LIGHT to quickly isolate and extract a variety of contaminants from soil and water.
Brandl had synthesized previously polymers that could be cleaved apart by exposure to UV LIGHT. But he and Bertrand came to question their suitability for drug delivery,
since UV LIGHT can be damaging to tissue and cells, and doesn penetrate through the skin.
When they learned that UV LIGHT was used to disinfect water in certain treatment plants, they began to ask a different question. e thought
if they are already using UV LIGHT, maybe they could use our particles as well, Brandl says. hen we came up with the idea to use our particles to remove toxic chemicals, pollutants,
because we saw that the particles aggregate once you irradiate them with UV LIGHT. trap for ater-fearingpollutionthe researchers synthesized polymers from polyethylene glycol,
But when exposed to UV LIGHT, the stabilizing outer shell of the particles is shed, and now nrichedby the pollutants they form larger aggregates that can then be removed through filtration, sedimentation,
and light sources thanks to the unprecedented properties it offers: very low electrical resistance high thermal conductivity and mechanically stretchable yet harder than diamond.
However unlike graphene TMDCS can also emit light allowing applications such as photodetectors and light emitting devices to be manufactured.
Until recently fabrication of TMDCS such as Mos2 has been difficult as most techniques produce only flakes typically just a few hundred square microns in area.
#A nanosized hydrogen generator (Phys. org) esearchers at the US Department of energy's (DOE) Argonne National Laboratory have created a small scale"hydrogen generator"that uses light
"For Rozhkova, this particular building block is inspired by the function of an ancient protein known to turn light into energy.
and platinum and then exposing them to ultraviolet light. There is just one downside: titanium dioxide only reacts in the presence of ultraviolet light,
which makes up a mere four percent of the total solar spectrum. If the researchers wanted to power their generators with sunlight,
In order to produce greater amounts of hydrogen using visible light, the researchers looked for a new material.
Graphene is a super strong, super light, near totally transparent sheet of carbon atoms and one of the best conductors of electricity ever discovered.
both the br protein and the graphene platform absorb visible light. Electrons from this reaction are transmitted to the titanium dioxide on
making the titanium dioxide sensitive to visible light. Simultaneously, light from the green end of the solar spectrum triggers the br protein to begin pumping protons along its membrane.
and time-resolved spectroscopy at the Center for Nanoscale Materials verified the movements of the electrons within the system,
#Ultra-thin high-speed detector captures unprecedented range of light waves New research at the University of Maryland could lead to a generation of light detectors that can see below the surface of bodies walls and other objects.
Using the special properties of graphene a two-dimensional form of carbon that is only one atom thick a prototype detector is able to see an extraordinarily broad band of wavelengths.
Included in this range is a band of light wavelengths that have exciting potential applications but are notoriously difficult to detect:
The light we see illuminating everyday objects is actually only a very narrow band of wavelengths and frequencies.
Terahertz light waves'long wavelengths and low frequencies fall between microwaves and infrared waves. The light in these terahertz wavelengths can pass through materials that we normally think of as opaque such as skin plastics clothing and cardboard.
It can also be used to identify chemical signatures that are emitted only in the terahertz range.
because when light is absorbed by the electrons suspended in the honeycomb lattice of the graphene they do not lose their heat to the lattice
New'T-ray'tech converts light to sound for weapons detection medical imaging More information: Sensitive Room-temperature Terahertz Detection via Photothermoelectric Effect in Graphene Xinghan Cai et al.
"Our experimental demonstration of such junctions between two-dimensional materials should enable new kinds of transistors, LEDS, nanolasers,
"The researchers have demonstrated already that the junction interacts with light much more strongly than the rest of the monolayer,
first light needs a good conductor in order to get converted into usable energy; secondly the cell also has to be transparent for light to get through.
Most solar cells on the market use indium tin oxide with a nonconductive glass protective layer to meet their needs.
and SGM beamlines at the Canadian Light source as well as a Beamline 8. 0. 1 at the Advanced Light source Hunt set out to learn more about how oxide groups attached to the graphene lattice changed it
They also are exploring using lasers to precisely shrink the plastic in specific patterns. Nam first had the idea for using Shrinky Dinks plastic to assemble nanomaterials after seeing a microfluidics device that used channels made of shrinking plastic.
that could harvest energy from light much more efficiently than traditional thin-film solar cells s
ED lighting has three different wavelengths of red blue and green. This system can control the illumination strength according to the stage of plant growth.
They designed a pixel that can not only measure incident light but also convert the incident light into electric power.
The key enabling device in a pixel is the photodiode, which produces an electric current when exposed to light.
The same photodiode is used also in solar panels to convert incident light to electric power. The photodiode in a camera pixel is used in the photoconductive mode
while in a solar cell it is used in the photovoltaic model. Nayar, working with research engineer Daniel Sims BS'14 and consultant Mikhail Fridberg of ADSP Consulting, used off-the-shelf components to fabricate an image sensor with 30x40 pixels.
each pixel's photodiode is operated always in the photovoltaic mode. The pixel design is very simple,
This research outcome potentially allows for great flexibility in the design and optimization of electronic and optoelectronic devices like solar panels and telecommunication lasers.
#Engineers Develop Optical devices That Shape Light in Exotic Ways Engineers from the Jet propulsion laboratory and the California Institute of technology have developed innovative flat,
optical lenses that are capable of manipulating light in ways that are difficult or impossible to achieve with conventional optical devices.
Manipulating the polarization of light is essential for the operation of advanced microscopes, cameras and displays;
or less than a hundredth of the thickness of a human hair. dditionally, the new, flat lenses can be used to modify the shape of light beams at will.
Semiconductor lasers typically emit into elliptical beams that are really hard to work with and the new metasurface optical components could replace expensive optical systems used to circularize the beams.
They also looked at an indirect and much less studied effect of UV LIGHT. When the active ingredients of sunscreen absorb UV LIGHT,
a chemical change triggers the generation of oxygen-carrying molecules known as reactive oxygen species (ROS). If a sunscreen agents penetrate the skin,
flexible tube with a light and camera attached to its end passes through a person digestive system.
which is solidified then once exposed to UV LIGHT. This advanced process results in these 3d printed microfish, able to swim naturally through liquids,
and detoxification is monitored easily due to the red light that is emitted on the device when nanoparticles are introduced to the particular toxins.
Now, researchers from MIT and the Federal University of Goias in Brazil have developed a new technique that uses ultraviolet (UV LIGHT to extract man-made pollutants from soil and water.
With the help of nanoparticles and UV LIGHT removal of these toxins could be less expensive and time-consuming than current methods.
and colleagues stumbled upon the idea of using UV LIGHT while they were initially designing photosensitive polymers for drug delivery applications.
Once they came up with a polymer that responded to UV LIGHT, they realized that this did not permeate well through skin
therefore asked ourselves in which infrastructures UV LIGHT was used already, Bertrand told Laboutlook. Knowing that UV radiation is used for removing bacteria from water,
when you shine UV LIGHT on them, the water-loving part is separated from the water-fearing part.
The system uses a beam of light on the floor, according to Georgia Tech. The warmrobots, which are in constant communication with each other,
when someone swipes the Apple ipad to drag the light across the floor, the robots follow.
"In a demonstration of the system, each robot is constantly measuring how much light is in its local eighborhood. hen there too much light in a robot area,
so that another robot can steal some of its light. he robots are working together to make sure that each one has the same amount of light in its own area,
Generally consisting of a flexible tube with a light source and an arrangement of lenses or small cameras in more modern devices the endoscope is a vital,
This research outcome potentially allows for great flexibility in the design and optimization of electronic and optoelectronic devices like solar panels and telecommunication lasers.
which individual particles of light are said to have been squeezed'--an achievement which at least one textbook had written off as hopeless September 1st, 201 0
and convert the light into electric current using excited states in the material called"excitons.""Roughly speaking, an exciton is displaced a electron bound together with the hole it left behind.
the UVM team--with support from the National Science Foundation--built a scanning laser microscope,
The instrument combines a specialized form of linearly polarized light and photoluminescence to optically probe the molecular structure of the phthalocyanine crystals."
2015first superconducting graphene created by UBC researchers September 9th, 2015hybrid solar cell converts both light and heat from sun's rays into electricity (video) September 9th,
Understanding motions of thin layers may help design solar cells, electronics and catalysts of the future September 10th, 2015hybrid solar cell converts both light and heat from sun's rays into electricity (video) September 9th,
2015nist physicists show'molecules'made of light may be possible September 10th, 2015ultrafast uncoupled magnetism in atoms:
Ultrafast terahertz spectroscopy yields direct insight into the building block of modern magnetic memories July 6th, 2015chip Technology Building the electron superhighway:
2015nist physicists show'molecules'made of light may be possible September 10th, 2015slac's ultrafast'electron camera'visualizes ripples in 2-D material:
The first nanometer resolved image of individual tobacco mosaic virions shows the potential of low energy electron holography for imaging biomolecules at a single particle level--a milestone in structural biology and a potential new tool
The work demonstrates the potential of low energy electron holography as a non-destructive, single-particle imaging technique for structural biology.
"We've shown that by means of low energy holography, it is possible to image individual tobacco mosaic virions deposited on ultraclean freestanding graphene,
Low energy electron holography is a technique of using an electron wave to form holograms. Similar to light optical holography
albeit with a much smaller wavelength, the complete information of the scattered wave, such as phase and amplitude, is recorded
thus enabling an unambiguous reconstruction of the object's structure.""The low energy electron holography has two major advantages over conventional microscopy.
First, the technique doesn't employ any lenses, so the resolution won't be limited by lens aberration.
in low energy electron holography, the employed electron doses can be much higher--even after exposing fragile molecules like DNA or proteins to a electron dose more than five orders of magnitude higher
Sufficient electron dose in low energy electron holography makes imaging individual biomolecules at a nanometer resolution possible.
To obtain the high-resolution hologram, an atomically sharp, tungsten tip acts as a source of a divergent beam of highly coherent electrons.
the researchers recorded the sample's high-resolution hologram, a pattern resulting from the interference of the two beams."
"Since low energy electron holography is a method very sensitive to mechanical disturbance, the current nanometer resolution could be improved to angstrom (one ten billionth of a meter)
just as lenses focus light and resonators (like the body of a guitar) amplify sound. They reported their findings in the May 8, 2015,
and whispering galleries are found in applications ranging from sensing, spectroscopy and communications to the generation of laser frequency combs.
Due to the light-like properties of graphene electrons, they can pass through unimpededno matter how high the barrierif they hit the barrier head on.
#Controlling swarms of robots with light and a single finger (w/video)( Nanowerk News) Using a smart tablet and a red beam of light,
A person taps the tablet to control where the beam of light appears on a floor. The swarm robots then roll toward the illumination,
When the person swipes the tablet to drag the light across the floor the robots follow.
Using a smart tablet and a red beam of light, Georgia Institute of technology researchers have created a system that allows people to control a fleet of robots with the swipe of a finger.
A person taps the tablet to control where the beam of light appears on a floor. The swarm robots then roll toward the illumination,
When the person swipes the tablet to drag the light across the floor the robots follow.
"In the Georgia Tech demonstration, each robot is constantly measuring how much light is in its local"neighborhood."
so that another can steal some of its light.""The robots are working together to make sure that each one has the same amount of light in its own area,
"said Egerstedt. The tablet-based control system has one final benefit: it was designed with everyone in mind.
This research outcome potentially allows for great flexibility in the design and optimization of electronic and optoelectronic devices like solar panels and telecommunication lasers.
This research outcome potentially allows for great flexibility in the design and optimization of electronic and optoelectronic devices like solar panels and telecommunication lasers.
and cameras that can be mass-produced using the same photolithography techniques used to manufacture computer microchips.
or monochromatic light oscillates at all points in space with the same frequency but varying relative delays, or phases.
Manipulating the polarization of light is essential for the operation of advanced microscopes, cameras, and displays;
and phase of light,"says study first author Amir Arbabi, a senior researcher at Caltech."
"We can take any incoming light and shape its phase and polarization profiles arbitrarily and with very high efficiency."
a metasurface device could manipulate light in novel ways that are very hard and sometimes impossible to do using current setups.
when illuminated by a horizontally polarized beam of light, and a different image when illuminated by a vertically polarized beam."
"The two images will appear overlapped under illumination with light polarized at 45 degrees, "Faraon says.
and have applications in superresolution microscopy, laser cutting, and particle acceleration.""You generally would need a large optical setup,
They also looked at an indirect and much less studied effect of UV LIGHT. When the active ingredients of sunscreen absorb UV LIGHT,
a chemical change triggers the generation of oxygen-carrying molecules known as reactive oxygen species (ROS). If a sunscreens agents penetrate the skin,
#Mini X-ray source driven by laser light alone The physicists have built a miniature X-ray source. In so doing, the researchers from the Laboratory of Attosecond Physics of the Max Planck Institute of Quantum Optics
and the Technische Universität München (TUM) have captured three-dimensional images of ultrafine structures in the body of a living organism for the first time with the help of laser-generated X-rays.
Using light-generated radiation combined with phase-contrast X-ray tomography, the scientists visualized ultrafine details of a fly measuring just a few millimeters.
By contrast, the laser-driven system in combination with phase-contrast X-ray tomography only requires a university laboratory to view soft tissues.
The paper states,-rays radiated by relativistic electrons driven by well-controlled high-power lasers offer a promising route to a proliferation of this powerful imaging technology.
A laser-driven plasma wave accelerates and wiggles electrons, giving rise to a brilliant kev X-ray emission. his so-called betatron radiation is emitted in a collimated beam with excellent spatial coherence and remarkable spectral stability.
Our results suggest that laser-based X-ray technology offers the potential for filling the large performance gap between synchrotron
For the first time, scientists coupled their technique for generating X-rays from laser pulses with phase-contrast X-ray tomography to visualize tissues in organisms.
The X-rays required were generated by electrons that were accelerated to nearly the speed of light over a distance of approximately one centimeter by laser pulses lasting around 25fs.
The laser pulses have a power of approximately 80tw. By way of comparison: an atomic power plant generates 1, 500mw.
First, the laser pulse ploughs through a plasma consisting of positively charged atomic cores and their electrons like a ship through water, producing a wake of oscillating electrons.
Each light pulse generates an X-ray pulse. The X-rays generated have special properties: a wavelength of approximately 0. 1nm,
which corresponds to a duration of only about 5fs, and are spatially coherent, i e. they appear to come from a point source.
For the first time, the researchers combined their laser-driven X-rays with a phase-contrast imaging method developed by a team headed by Prof.
This laser-based imaging technique enables creation of three-dimensional images of objects. After each X-ray pulse, meaning after each frame,
however, researchers must shorten the wavelength of the X-rays even further in order to penetrate thicker tissue layers t
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