Menu

Blog

Page 6025

Oct 13, 2020

Study uncovers the role of exciton lifetimes in enabling highly efficient organic solar cells

Posted by in categories: solar power, sustainability

Organic photovoltaics are a third-generation solar cell technology made of electron donor and electron acceptor materials instead of conventional semiconductor p-n junctions. The performance of this alternative solar cell technology has improved significantly over the past few years and it is now comparable to that of classical inorganic solar cells, both in terms of charge carrier yields (i.e., electrical current generation) and solar spectrum matching.

The only feature of organic photovoltaics that still lags behind traditional solar cells is its achievable voltage (VOC, which stands for open circuit voltage). As electrical power is the product of voltage and current, however, the poor VOC of organic solar cells currently prevents their successful commercialization.

Researchers at the Institute of Materials for Electronics and Energy Technology (i-MEET) in Germany and the National Hellenic Research Foundation (NHRF) in Greece have been investigating specific features of materials used to build organic photovoltaics that could enable greater efficiencies and achievable voltages. Their paper, published in Nature Energy, shows that materials with long exciton lifetimes could be particularly promising for the creation of efficient organic solar cells.

Oct 13, 2020

FarmBot automates tending, weeding, and watering a garden and makes it as easy as playing a video game to feed a family of 4 — here’s how it works

Posted by in categories: education, robotics/AI

The Farmbot can be used for small-scale home gardens, education, or larger projects.

Oct 13, 2020

Humans can develop a genetic tolerance for arsenic

Posted by in categories: biotech/medical, genetics

There’s no need to fear arsenic poisoning if you grew up in the Argentinian Andes — hundreds of years of drinking arsenic-laced groundwater will have left you with a genetic tolerance for it.

Geneticists from Lund and Uppsala universities had noticed that certain plants and bacteria could live in environments with lots of arsenic, with natural selection favouring a gene known to improve their ability to metabolise the poison. Curious to see if humans could also gain some kind of arsenic immunity, they looked at a group of people who they knew would have been exposed to the poison over many generations — the indigenous peoples of the Argentinian part of the Andes. Sure enough, a higher-than average proportion of people they studied possessed the AS3MT gene, which lets them flush out toxins faster than “normal” people.

The genetic samples tested for the AS3MT gene came from 346 residents of the small, isolated town of San Antonio de los Cobres, located more than 3,700m above sea level in the Andes. Not only does the bedrock in the surrounding area contain a lot of arsenic which gets into the groundwater, but mining operations from the era of Spanish colonisation onwards have released even more arsenic — so both modern people and mummies dating back 7,000 years have had high levels of arsenic found in their hair and internal organs.

Oct 12, 2020

Graphene Detector Reveals THz Light’s Polarization Using Interference of Plasma Waves

Posted by in categories: biotech/medical, chemistry, security

Physicists have created a broadband detector of terahertz radiation based on graphene. The device has potential for applications in communication and next-generation information transmission systems, security, and medical equipment. The study came out in ACS Nano Letters.

The new detector relies on the interference of plasma waves. Interference as such underlies many technological applications and everyday phenomena. It determines the sound of musical instruments and causes the rainbow colors in soap bubbles, along with many other effects. The interference of electromagnetic waves is harnessed by various spectral devices used to determine the chemical composition, physical and other properties of objects — including very remote ones, such as stars and galaxies.

Plasma waves in metals and semiconductors have recently attracted much attention from researchers and engineers. Like the more familiar acoustic waves, the ones that occur in plasmas are essentially density waves, too, but they involve charge carriers: electrons and holes. Their local density variation gives rise to an electric field, which nudges other charge carriers as it propagates through the material. This is similar to how the pressure gradient of a sound wave impels the gas or liquid particles in an ever expanding region. However, plasma waves die down rapidly in conventional conductors.

Oct 12, 2020

Generating Megatesla Magnetic Fields on Earth Using Intense-Laser-Driven Microtube Implosions

Posted by in categories: biotech/medical, engineering, supercomputing

A team of researchers led by Osaka University discovers “microtube implosion,” a novel mechanism that demonstrates the generation of megatesla-order magnetic fields.

Magnetic fields are used in various areas of modern physics and engineering, with practical applications ranging from doorbells to maglev trains. Since Nikola Tesla’s discoveries in the 19th century, researchers have strived to realize strong magnetic fields in laboratories for fundamental studies and diverse applications, but the magnetic strength of familiar examples are relatively weak. Geomagnetism is 0.3−0.5 gauss (G) and magnetic tomography (MRI) used in hospitals is about 1 tesla (T = 104 G). By contrast, future magnetic fusion and maglev trains will require magnetic fields on the kilotesla (kT = 107 G) order. To date, the highest magnetic fields experimentally observed are on the kT order.

Recently, scientists at Osaka University discovered a novel mechanism called a “microtube implosion,” and demonstrated the generation of megatesla (MT = 1010 G) order magnetic fields via particle simulations using a supercomputer. Astonishingly, this is three orders of magnitude higher than what has ever been achieved in a laboratory. Such high magnetic fields are expected only in celestial bodies like neutron stars and black holes.

Oct 12, 2020

AI helps produce world’s largest 3D map of the universe

Posted by in categories: information science, robotics/AI, space

Scientists at the University of Hawaii’s Mānoa Institute for Astronomy (IfA) have used AI to produce the world’s largest 3D catalog of stars, galaxies, and quasars.

The team developed the map using an optical survey of three-quarters of the sky produced by the Pan-STARRS observatory on Haleakalā, Maui.

They trained an algorithm to identify celestial objects in the survey by feeding it spectroscopic measurements that provide definitive object classifications and distances.

Oct 12, 2020

Ancient DNA lab maps little-explored human lineages

Posted by in categories: biotech/medical, health

Most previous ancient DNA work involves people of European ancestry. A focus of the Emory lab, however, is exploring how environmental changes — including those caused by European contact — affected the biology of Indigenous and other populations of the Americas.

“Our work can connect people to ancestries they potentially don’t know about,” Lindo explains. “It can also give them insights into how historic, and even prehistoric, events may be affecting them today, especially in terms of health risks and disparities.”

Lindo establishes relationships with local and Indigenous people who decide whether unearthed remains from their communities will be analyzed and how the data will be used. Visiting scientists and scholars from these communities will come to the Emory lab, working alongside Emory scientists and students, exchanging knowledge, insights and perspectives.

Oct 12, 2020

AMD’s Infinity Cache could be Big Navi’s secret weapon to beat Nvidia’s RTX 3000 GPUs

Posted by in category: computing

To Infinity Cache and beyond?


If Big Navi does run with a 256-bit bus as some rumors suggest, cache could be the key to the graphics card’s performance.

Oct 12, 2020

Stacking and twisting graphene unlocks a rare form of magnetism

Posted by in categories: materials, particle physics

Since the discovery of graphene more than 15 years ago, researchers have been in a global race to unlock its unique properties. Not only is graphene—a one-atom-thick sheet of carbon arranged in a hexagonal lattice—the strongest, thinnest material known to man, it is also an excellent conductor of heat and electricity.

Now, a team of researchers at Columbia University and the University of Washington has discovered that a variety of exotic electronic states, including a rare form of magnetism, can arise in a three-layer structure.

The findings appear in an article published Oct. 12 in Nature Physics.

Oct 12, 2020

Tesla is looking to move to steer-by-wire with new motor and geartrain team in Austin

Posted by in categories: sustainability, transportation

Tesla is looking into moving “current and future vehicle programs” to steer-by-wire with a new motor, geartrain, and chassis team in Austin, Texas.

Over the last few months, we have been reporting on how Tesla plans to establish new teams in Austin that are not directly related to the new Gigafactory under construction.

For example, we previously reported on Tesla building a new video game and user interface team in Austin.