ASPR Blog February 13, 2019 To help protect the nation from emerging and pandemic infectious diseases and CBRN threats, HHS published the 2019-2022 National Health Security Strategy (NHSS) , its quadrennial strategy to prepare and safeguard the nation’s health in times of crisis. A premise behind the report is that all levels of government and private sector partners have important roles to play to improve the nation’s ability to respond to and recover from 21st century threats. To protect the nation more effectively from these emerging threats, HHS will use this whole of government/nation approach to, Deepen interoperability, Support and sustain […]
A polariton filter turns ordinary laser light into quantum light
Phys.org February 19, 2016 An international team of researchers (Australia, France) used nanometre-thick films made of gallium arsenide and sandwiched them between two mirrors to manipulate the incoming photons. The photons interact with electron-hole pairs in the semiconductor, forming polaritons that carry properties from both the photons and the electron-hole pairs. The polaritons decay after a few picoseconds, and the photons they release exhibit distinct quantum signatures. While these quantum signatures are weak at the moment, the work opens a new avenue for producing single photons on demand. Once they are able to increase the strength of the quantum signatures, […]
International research collaboration computes climate past, present, and future
Eurekalert February 18, 2019 An international team of researchers (Canada, Germany) is working on ClimEx Project to improve researchers’ understanding of severe flooding dynamics under changing climate conditions. To investigate extreme floods associated with long return periods, there is a relatively short time period to reference, often less than 30 years of accurate, detailed data. To predict flooding, the team further downscales the ClimEx simulations statistically to provide input data for hyper-accurate, high-resolution hydrological modeling. The team’s simulations showed good agreement with historical climate data, leaving them confident in its predictive power and its ability to help improve impact models […]
The first walking robot that moves without GPS
Science Daily February 13, 2019 To navigate safely in hostile environment, desert ants assess their direction from the polarized pattern of skylight and judge the distance traveled based on both a stride-counting method and the optic flow. Using this concept a team of researchers in France has designed AntBot equipped with an optical compass used to determine its direction by means of polarized light, and by an optical movement sensor directed to the sun to measure the distance covered. Armed with this information, AntBot was able to explore its environment and to return on its own to its base, with […]
Exotic spiraling electrons discovered by physicists
Phys.org February 18, 2019 Excitons form when intense light shines on solids, kicking negatively charged electrons out of their spots and leaving behind positively charged holes. A team of researchers in the US (Rutgers University, University of Florida, North Carolina State University) has discovered chiral surface exciton on the surface of bismuth selenide. Chiral exiton consists of particles and anti-particles bound together and swirling around each other on the surface of solids. The electrons and holes resemble rapidly spinning tops. The electrons eventually “spiral” towards the holes, annihilating each other in less than a trillionth of a second while emitting […]
Engineered metasurfaces reflect waves in unusual directions
Nanowerk February 16, 2019 An international team of researchers (Finland, USA – Duke University) introduced purely local reflective metasurfaces for arbitrary manipulations of the power distribution of reflected waves without excitation of any auxiliary evanescent field. The method is based on the analysis of the power flow distribution and the adaptation of the reflector shape to the desired distribution of incident and reflected fields. As a result, they found that these power-conformal metamirrors can be easily implemented with conventional passive unit cells. The results can be used for the design of reflecting surfaces with multiple functionalities and for waves of […]
China Stumbles on Path to Solar Thermal Supremacy
IEEE Spectrum February 14, 2019 Solar thermal plants are a potentially crucial power source for global grids as they add more wind and PV. However, the technology is comparatively costly and thus growing slowly relative to PV and wind. China’s program has been viewed as an opportunity to put solar thermal technology back on track, slash the cost of solar thermal power and catapult Chinese firms to the head of the global pack. In the final days of 2018 a 100-megawatt solar thermal generating station capable of running around-the-clock, 365-days-a-year was to be connected to the Northwest China regional power […]
China Is Reportedly Building a Solar Power Station in Space
Science Alert February 2019 China has plans to launch a test facility before 2025, pursuing space-based clean energy showing that China is committed to its ongoing push towards using more renewable energy and asserting its place among global leaders in space. The plan is to have solar arrays in space capture light from the sun and then beam electricity down to a facility on Earth in the form of a microwave or a laser. If the launch goes well and the energy-transmitting beam works like it is supposed to, the Chinese scientists have plans to test and launch bigger and […]
Can we trust scientific discoveries made using machine learning?
Eurekalert February 15, 2019 According to the researchers at Rice University machine learning field has focused on developing predictive models that allow machine learning to make predictions about future data based on its understanding of data it has studied. A lot of these techniques are designed to always make a prediction. They never come back with ‘I don’t know,’ or ‘I didn’t discover anything,’ because they aren’t made to. People have applied machine learning to genomic data from clinical cohorts to find groups, or clusters, of patients with similar genomic profiles. But there are cases where discoveries aren’t reproducible; the […]
Across the spectrum: Researchers find way to stabilize color of light in next-gen material
Science Daily February 11, 2019 Color tunability has always been possible with halide perovskites, but it’s not been stable. While the bandgap can be conveniently tuned by mixing different halogen ions, mixed-halide perovskites suffer from severe phase separation under illumination. A team of researchers in the US (Florida State University, Rensselaer Polytechnic Institute) found that phase separation can be highly suppressed by embedding nanocrystals of mixed-halide perovskites in an endotaxial matrix. The tuned bandgap remains remarkably stable under extremely intensive illumination. The agreement between the experiments and a nucleation model suggests that the size of the nanocrystals and the host-guest […]