Posts belonging to Category light



Glass Blocks Generate Electricity Using Solar Energy

Buildings consume more than forty percent of global electricity and reportedly cause at least a third of carbon emissions. Scientists want to cut this drastically – and create a net-zero energy future for new buildings. Build Solar want to help. The firm has created a glass brick containing small solar cells.

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On top of this we have placed in some intelligent optics which are able to focus the incoming sunlight onto these solar cells almost throughout the day. When we do that we are able to generate a higher amount of electrical output from each solar cell that we are using,” says Dr Hasan Baig, founder of Build Solar.
As well as converting the sun’s power to electricity, the bricks have other abilities.
The product is aligned to provide three different things, including electricity, daylighting, and thermal insulation which is generally required by any kind of construction product. More importantly it is aesthetic in its look, so it fits in very well within the building architecture,” adds Dr Baig.
Using Building Integrated Photovoltaics, the technology would be used in addition to existing solar roof panels. The University of Exeter spin-off is fine-tuning the design, which works in many colours. The company says the product could be market ready by the end of next year.

Source: https://www.buildsolar.co.uk/

New Quantum Computer Uses 10,000 Times Less Power

Japan has unveiled its first quantum computer prototype, amid a global race to build ever-more powerful machines with faster speeds and larger brute force that are key towards realising the full potential of artificial intelligence. Japan’s machine can theoretically make complex calculations 100 times faster than even a conventional supercomputer, but use just 1 kilowatt of power – about what is required by a large microwave oven – for every 10,000 kilowatts consumed by a supercomputer. Launched recently, the creators – the National Institute of Informatics, telecom giant NTT and the University of Tokyo – said they are building a cloud system to house their “quantum neural network” technology.

In a bid to spur further innovation, this will be made available for free to the public and fellow researchers for trials at https://qnncloud.com
The creators, who aim to commercialise their system by March 2020, touted its vast potential to help ease massive urban traffic congestion, connect tens of thousands of smartphones to different base stations for optimal use in a crowded area, and even develop innovative new drugs by finding the right combination of chemical compounds.

Quantum computers differ from conventional supercomputers in that they rely on theoretical particle physics and run on subatomic particles such as electrons in sub-zero temperatures. Most quantum computers, for this reason, destabilise easily and are error-prone, thereby limiting their functions.

We will seek to further improve the prototype so that the quantum computer can tackle problems with near-infinite combinations that are difficult to solve, even by modern computers at high speed,” said Stanford University Professor Emeritus Yoshihisa Yamamoto, who is heading the project.
Japan’s prototype taps into a 1km-long optical fibre cable packed with photons, and exploits the properties of light to make super-quick calculations. Its researchers said they deemed the prototype ready for public use, after tests showed that it was capable of operating stably around the clock at room temperature.

Source: http://www.straitstimes.com/

Breathing in Delhi air equivalent to smoking 44 cigarettes a day

It was early on the morning when residents in the Indian capital of Delhi first began to notice the thick white haze that had descended across the city. Initially viewed as a mild irritant, by mid-week its debilitating effects were evident to all, as the city struggled to adapt to the new eerie, martian-like conditions brought about by the pollution.

The World Health Organization considers anything above 25 to be unsafe. That measure is based on the concentration of fine particulate matter, or PM2.5, per cubic meter. The microscopic particles, which are smaller than 2.5 micrometers in diameter, are considered particularly harmful because they are small enough to lodge deep into the lungs and pass into other organs, causing serious health risks.
With visibility severely reduced, trains have been canceled, planes delayed and cars have piled into each other, with multiple traffic accidents reported across the city. On the afternoon, city chiefs closed all public and private schools, requesting instead that the city’s tens of thousands of school-aged children remain indoors; they banned incoming trucks and halted civil construction projects; while they announced new plans to begin implementing a partial ban on private car use as of next week. But as the city woke up to a fourth straight day of heavy pollution, practical considerations were being overtaken by more serious concerns, with journalists and doctors warning residents of the long-term health implications.

Air quality readings in the Indian capital have reached frightening levels in recent days, at one point topping the 1,000 mark on the US embassy air quality index. Across the capital, doctors reported a surge in patients complaining of chest pain, breathlessness and burning eyes. “The number of patients have increased obviously,” said Deepak Rosha, a pulmonologist at Apollo Hospital, one of the largest private hospitals in Delhi. “I don’t think it’s ever been so bad in Delhi. I’m very angry that we’ve had to come to this.”
Breathing in air with a PM2.5 content of between 950 to 1,000 is considered roughly equivalent to smoking 44 cigarettes a day, according to the independent Berkeley Earth science research group.

Photovoltaics: Light Absorption Enhanced by Up to 200 Percent

Sunlight reflected by solar cells is lost as unused energy. The wings of the butterfly Pachliopta aristolochiae are drilled by nanostructures (nanoholes) that help absorbing light over a wide spectrum far better than smooth surfaces. Researchers of Karlsruhe Institute of Technology (KIT) in Germany, have now succeeded in transferring these nanostructures to solar cells and, thus, enhancing their light absorption rate by up to 200 percent.

 “The butterfly studied by us is very dark black. This signifies that it perfectly absorbs sunlight for optimum heat management. Even more fascinating than its appearance are the mechanisms that help reaching the high absorption. The optimization potential when transferring these structures to photovoltaics (PV) systems was found to be much higher than expected,” says Dr. Hendrik Hölscher of KIT’s Institute of Microstructure Technology (IMT).

 

The scientists of the team of Hendrik Hölscher and Radwanul H. Siddique (formerly KIT, now Caltech) reproduced the butterfly’s nanostructures in the silicon absorbing layer of a thin-film solar cell. Subsequent analysis of light absorption yielded promising results: Compared to a smooth surface, the absorption rate of perpendicular incident light increases by 97% and rises continuously until it reaches 207% at an angle of incidence of 50 degrees. “This is particularly interesting under European conditions. Frequently, we have diffuse light that hardly falls on solar cells at a vertical angle,” Hendrik Hölscher says. However, this does not automatically imply that efficiency of the complete PV system is enhanced by the same factor, says Guillaume Gomard of IMT. “Also other components play a role. Hence, the 200 percent are to be considered a theoretical limit for efficiency enhancement.

The scientists have reported their results in the journal Science Advances. (DOI: 10.1126/sciadv.1700232.)

Source: http://www.kit.edu/

Invisible Glass

If you have ever watched television in anything but total darkness, used a computer while sitting underneath overhead lighting or near a window, or taken a photo outside on a sunny day with your smartphone, you have experienced a major nuisance of modern display screens: glare. Most of today’s electronics devices are equipped with glass or plastic covers for protection against dust, moisture, and other environmental contaminants, but light reflection from these surfaces can make information displayed on the screens difficult to see. Now, scientists at the Center for Functional Nanomaterials (CFN) — a U.S. Department of Energy Office of Science User Facility at Brookhaven National Laboratory — have demonstrated a method for reducing the surface reflections from glass surfaces to nearly zero by etching tiny nanoscale features into them.

Whenever light encounters an abrupt change in refractive index (how much a ray of light bends as it crosses from one material to another, such as between air and glass), a portion of the light is reflected. The nanoscale features have the effect of making the refractive index change gradually from that of air to that of glass, thereby avoiding reflections. The ultra-transparent nanotextured glass is antireflective over a broad wavelength range (the entire visible and near-infrared spectrum) and across a wide range of viewing angles. Reflections are reduced so much that the glass essentially becomes invisible.

This “invisible glass” could do more than improve the user experience for consumer electronic displays. It could enhance the energy-conversion efficiency of solar cells by minimizing the amount of sunlight lost to refection. It could also be a promising alternative to the damage-prone antireflective coatings conventionally used in lasers that emit powerful pulses of light, such as those applied to the manufacture of medical devices and aerospace components.

We’re excited about the possibilities,” said CFN Director Charles Black, corresponding author on the paper published online on October 30 in Applied Physics Letters. “Not only is the performance of these nanostructured materials extremely high, but we’re also implementing ideas from nanoscience in a manner that we believe is conducive to large-scale manufacturing.”

Our role in the CFN is to demonstrate how nanoscience can facilitate the design of new materials with improved properties,” concluded Black. “This work is a great example of that–we’d love to find a partner to help advance these remarkable materials toward technology.”

Source: https://www.eurekalert.org/

Using Brain-Machine Interfaces, Mental Power Can Move Objects

A unique citizen science project in which volunteers will be trained to move a piece of steel machinery using the power of their mind begins on October 27. The Mental Work project uses brain-machine interfaces developed at EPFL (Ecole polytechnique fédérale de Lausanne) in Switzerland, a convergence of science, art, and design .

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At the mental work factory the public can come and we equip them with an EEG helmet which will read the mental activity, the electrical activity, that’s in their brain. These helmets are dry, so we don’t need gel for conductivity and they’re also wireless so they can walk through the mental factory and engage with four of our machines activating them with only their mental activity,  explains Michael Mitchell , who is one of the three co-founders of Mental Work.

The data that will be collected during the mental worker’s trajectory throughout our factory floor will then be made anonymous and given to the brain machine interface community to improve the interfaces for the future. “We think that we’re on the cusp of a cognitive revolution. Now a cognitive revolution is going to be a world where our brains are intimately connected to our physical world around us. With the development of these brain machine interfaces we think that we are really at the beginning of a moment in time where man is going to become the centre of all this technology. His brain activity is going to interact with the physical world around him in ways that we can hardly imagine today. “So I think it’s understandable if people are a little apprehensive about this technology because some people may think ‘oh, it can read my thoughts and then what are we going to do with those thoughts. Where’s the privacy level here?’ But in fact we’re only asking you to modulate your brain activity according to your own will. So it’s as simple as sending a command to a computer using a mouse or a keyboard. But this time we’re using asking you to use your brain. Now we want to bring this technology to the public at a early phase of its development so that we can create a dialogue about what kind of relationship we want to have with this technology in particular but also with man’s relationship to technology in general.

Source: https://actu.epfl.ch/

How To Track Blood Flow In Tiny Vessels

Scientists have designed gold nanoparticles, no bigger than 100 nanometres, which can be coated and used to track blood flow in the smallest blood vessels in the body. By improving our understanding of blood flow in vivo the nanoprobes represent an opportunity to help in the early diagnosis of diseaseLight microscopy is a rapidly evolving field for understanding in vivo systems where high resolution is required. It is particularly crucial for cardiovascular research, where clinical studies are based on ultrasound technologies which inherently have lower resolution and provide limited information.

The ability to monitor blood flow in the sophisticated vascular tree (notably in the smallest elements of the microvasculaturecapillaries) can provide invaluable information to understand disease processes such as thrombosis and vascular inflammation. There are further applications for the improved delivery of therapeutics, such as targeting tumours.

Currently, blood flow in the microvasculature is poorly understood. Nanoscience is uniquely placed to help understand the processes happening in the micron-dimensioned vessels. Designing probes to monitor blood flow is challenging because of the environment; the high protein levels in plasma and the high red blood cell concentrations are detrimental to optical imaging. Conventional techniques rely on staining red blood cells, using organic dyes with short-lived usage due to photobleaching, as the tracking motif. The relatively large size of the red blood cells (7-8 micrometres), which are effectively the probes, limits the resolution in imaging and analysis of flow dynamics of the smallest vessels which are of a similar width. Therefore, to have more detailed resolution and information about the blood flow in the microvasculature, even smaller probes are required.

The key to these iridium-coated nanoparticles lies in both their small size, and in the characteristic luminescent properties. The iridium gives a luminescent signal in the visible spectrum, providing an optical window which can be detected in blood. It is also long-lived compared to organic fluorophores, while the tiny gold particles are shown to be ideal for tracking flow and detect clearly in tissues“, explains Professor Zoe Pikramenou, from the School of Chemistry at  the University of Birmingham.

The findings have been published in the journal Nanomedicine.

Source: https://www.birmingham.ac.uk/

How To Extract Hydrogen Fuel from Seawater

It’s possible to produce hydrogen to power fuel cells by extracting the gas from seawater, but the electricity required to do it makes the process costly. UCF researcher Yang Yang from the University of Central Florida (UCF)  has come up with a new hybrid nanomaterial that harnesses solar energy and uses it to generate hydrogen from seawater more cheaply and efficiently than current materials. The breakthrough could someday lead to a new source of the clean-burning fuel, ease demand for fossil fuels and boost the economy of Florida, where sunshine and seawater are abundant. Yang, an assistant professor with joint appointments in the University of Central Florida’s NanoScience Technology Center and the Department of Materials Science and Engineering, has been working on solar hydrogen splitting for nearly 10 years.

It’s done using a photocatalyst – a material that spurs a chemical reaction using energy from light. When he began his research, Yang focused on using solar energy to extract hydrogen from purified water. It’s a much more difficulty task with seawater; the photocatalysts needed aren’t durable enough to handle its biomass and corrosive salt.

We’ve opened a new window to splitting real water, not just purified water in a lab,” Yang said. “This really works well in seawater.”

As reported in the journal Energy & Environmental Science, Yang and his research team have developed a new catalyst that’s able to not only harvest a much broader spectrum of light than other materials, but also stand up to the harsh conditions found in seawater.

 

Source: https://today.ucf.edu/

One-Two Knockout Punch To Eradicate Super Bugs

Light-activated nanoparticles, also known as quantum dots, can provide a crucial boost in effectiveness for antibiotic treatments used to combat drug-resistant superbugs such as E. coli and Salmonella, new CU Boulder research shows. Multi-drug resistant pathogens, which evolve their defenses faster than new antibiotic treatments can be developed to treat them, cost the United States an estimated $20 billion in direct healthcare costs and an additional $35 billion in lost productivity in 2013. Rather than attacking the infecting bacteria conventionally, the dots release superoxide, a chemical species that interferes with the bacteria’s metabolic and cellular processes, triggering a fight response that makes it more susceptible to the original antibiotic.

We’ve developed a one-two knockout punch,” said Prashant Nagpal, an assistant professor in CU Boulder’s Department of Chemical and Biological Engineering (CHBE) and the co-lead author of the study. “The bacteria’s natural fight reaction [to the dots] actually leaves it more vulnerable.”

We are thinking more like the bug,” explains Anushree Chatterjee, an assistant professor in CHBE and the co-lead author of the study. “This is a novel strategy that plays against the infection’s normal strength and catalyzes the antibiotic instead.” The dots reduced the effective antibiotic resistance of the clinical isolate infections by a factor of 1,000 without producing adverse side effects.

The findings have been published today in the journal Science Advances.

Source: http://www.colorado.edu/

How To Forge Graphene In 3D Shape

The wonder material graphene gets many of its handy quirks from the fact that it exists in two dimensions, as a sheet of carbon only one atom thick. But to actually make use of it in practical applications, it usually needs to be converted into a 3D form. Now, researchers have developed a new and relatively simple way to do just that, using lasers to “forge” a three-dimensional pyramid out of graphene.

This isn’t the first time graphene has been given an extra dimension. In 2015, researchers from the University of Illinois molded graphene into 3D structures by layering it onto shaped substrates, and early this year MIT scientists found that tubes of the stuff could be shaped into 3D coral-like structures 10 times stronger than steel but just five percent as dense. Rice University researchers have also recently made graphene foam and reinforced it with carbon nanotubes.

But this new technique, developed by researchers in Finland and Taiwan, might be an easier and faster method to make 3D graphene. By focusing a laser onto a fine point on a 2D graphene lattice, the graphene at that spot is irradiated and bulges outwards. A variety of three-dimensional shapes can be made by writing patterns with the laser spot, with the height of the shape controlled by adjusting the irradiation dose at each particular point.

The team illustrated that technique by deforming a sheet of graphene into a 3D pyramid, standing 60 nm high. That sounds pretty tiny, but it’s 200 times taller than the graphene sheet itself.

We call this technique optical forging, since the process resembles forging metals into 3D shapes with a hammer,” says Mika Pettersson, co-author of the study. “In our case, a laser beam is the hammer that forges graphene into 3D shapes. The beauty of the technique is that it’s fast and easy to use; it doesn’t require any additional chemicals or processing. Despite the simplicity of the technique, we were very surprised initially when we observed that the laser beam induced such substantial changes on graphene. It took a while to understand what was happening.”

The researchers initially assumed that the laser had “doped” the graphene, introducing impurities into the material, but after further examination they found that wasn’t the case.

When we first examined the irradiated graphene, we were expecting to find traces of chemical species incorporated into the graphene, but we couldn’t find any,” comments Wei Yen Woon, co-author of the study. “After some more careful inspections, we concluded that it must be purely structural defects, rather than chemical doping, that are responsible for such dramatic changes on graphene.

The scientists explain that the optically forged graphene is structurally sound, highlighting its potential for building 3D architectures out of the material for a wide range of applications. In this form, the graphene has different electronic and optical properties from its 2D counterpart.

The research was published in the journal Nano Letters.

Source: Academy of Finland

Graphene, Not Glass, Is The Key To Better Optics

A lens just a billionth of a metre thick could transform phone cameras. Researchers at Swinburne University in Melbourne, Australia, have created ultra-thin lenses that cap an optical fibre, and can produce images with the quality and sharpness of much larger glass lenses.

Compared with current lenses, our graphene lens only needs one film to achieve the same resolution,” says Professor Baohua Jia, a research leader at Swinburne’s Centre for Micro-Photonics. “In the future, mobile phones could be much thinner, without having to sacrifice the quality of their cameras. Our lens also allows infrared light to pass through, which glass lenses don’t.”

Producing graphene can be costly and challenging, so Baohua and her colleagues used a laser to pattern layers of graphene oxide (graphene combined with oxygen). By then removing the oxygen, they produced low-cost, patterned films of graphene, a thousand times thinner than a human hair. “By patterning the graphene oxide film in this way, its optical and electrical properties can be altered, which allowed us to place them in different devices,” she says.

Warm objects give off infrared light, so mobile phones with graphene lenses could be used to scan for hotspots in the human body and help in the early identification of diseases like breast cancer. By attaching the lens to a fibre optic tip, endoscopes — instruments that are currently several millimetres wide—could be made a million times smaller. The team is also investigating graphene’s amazing properties for their potential use as supercapacitors, capable of storing very large amounts of energy, which could replace conventional batteries.

Baohua’s work on graphene lenses was published in Nature Communications.

Source: https://cosmosmagazine.com/

Optical Computer

Researchers at the University of Sydney (Australia) have dramatically slowed digital information carried as light waves by transferring the data into sound waves in an integrated circuit, or microchipTransferring information from the optical to acoustic domain and back again inside a chip is critical for the development of photonic integrated circuits: microchips that use light instead of electrons to manage data.

These chips are being developed for use in telecommunications, optical fibre networks and cloud computing data centers where traditional electronic devices are susceptible to electromagnetic interference, produce too much heat or use too much energy.

The information in our chip in acoustic form travels at a velocity five orders of magnitude slower than in the optical domain,” said Dr Birgit Stiller, research fellow at the University of Sydney and supervisor of the project.

It is like the difference between thunder and lightning,” she said.

This delay allows for the data to be briefly stored and managed inside the chip for processing, retrieval and further transmission as light wavesLight is an excellent carrier of information and is useful for taking data over long distances between continents through fibre-optic cables.

But this speed advantage can become a nuisance when information is being processed in computers and telecommunication systems.

Source: https://sydney.universty.au/