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Topic Review
Wide Field Infrared Survey Telescope
The Wide Field Infrared Survey Telescope (WFIRST) is a NASA infrared space observatory currently under development. WFIRST was recommended in 2010 by United States National Research Council Decadal Survey committee as the top priority for the next decade of astronomy. On February 17, 2016, WFIRST was approved for development and launch. WFIRST is based on an existing 2.4 m wide field-of-view telescope and will carry two scientific instruments. The Wide-Field Instrument is a 288-megapixel multi-band near-infrared camera, providing a sharpness of images comparable to that achieved by the Hubble Space Telescope (HST) over a 0.28 square degree field of view, 100 times larger than that of the HST. The Coronagraphic Instrument is a high-contrast, small field-of-view camera and spectrometer covering visible and near-infrared wavelengths using novel starlight-suppression technology. The design of WFIRST is based on one of the proposed designs for the Joint Dark Energy Mission between NASA and DOE. WFIRST adds some extra capabilities to the original JDEM proposal, including a search for extra-solar planets using gravitational microlensing. In its present incarnation (2015), a large fraction of its primary mission will be focused on probing the expansion history of the Universe and the growth of cosmic structure with multiple methods in overlapping redshift ranges, with the goal of precisely measuring the effects of dark energy, the consistency of general relativity, and the curvature of spacetime. On February 12, 2018, development on the WFIRST mission was proposed to be terminated in the President's FY19 budget request, due to a reduction in the overall NASA astrophysics budget and higher priorities elsewhere in the agency. However, in March 2018 Congress approved funding to continue making progress on WFIRST until at least September 30, 2018, in a bill stating that Congress "rejects the cancellation of scientific priorities recommended by the National Academy of Sciences decadal survey process".[needs update] In testimony before Congress in July 2018, NASA administrator Jim Bridenstine proposed slowing down the development of WFIRST in order to accommodate a cost increase in the James Webb Space Telescope (JWST), which would result in decreased[clarification needed] funding for WFIRST in 2020/2021. In the President's FY2020 budget request, termination of WFIRST was proposed again, due to cost overruns and higher priority for JWST.. The telescope received $511 million for FY2020.
  • 1.1K
  • 29 Nov 2022
Topic Review
Diatom-Based Biosensors
Porous materials showing some useful transducing features, i.e., any changes in their physical or chemical properties as a consequence of molecular interaction, are very attractive in the realization of sensors and biosensors. Diatom frustules have been gaining support for biosensors since they are made of nanostructured amorphous silica, but do not require any nano-fabrication step; their surface can be easily functionalized and customized for specific application; diatom frustules are photoluminescent, and they can be found in almost every pond of water on the Earth, thus assuring large and low-cost availability.
  • 1.1K
  • 31 Mar 2021
Topic Review
3D Printed Electromagnetic Vibration Harvesters
Energy harvesting is the utilisation of ambient energy in order to power electronics such as wireless sensor nodes (WSN) or wearables without the need of batteries. This allows to operate the node over a much longer time period compared to battery-powered devices along with lower maintenance efforts. Furthermore, the low-maintenance requirements allow to operate these WSNs in environments with limited or no accessibility.
  • 1.1K
  • 05 Nov 2021
Topic Review
Spins in Semiconductor Nanoparticles
- Spin-dependent phenomena in semiconductors are analyzed starting from a theory of the dynamic nuclear polarization via numerous insightful findings in the realm of characterization and control through the nuclear spin polarization in nanoparticles and their aggregates into microparticles as potential contrast agents for magnetic resonance imaging (MRI) applications.  - Electron spin-dependent process of the photosensitized generation of singlet oxygen in porous silicon (Si) for photodynamic therapy application and design of Si-based nanoparticles with electron spin centers for MRI contrasting for cancer theranostics are discussed.  
  • 1.1K
  • 12 Jan 2021
Topic Review
Optical Tweezers
Optical tweezers is a very well-established technique that has developed into a standard tool for trapping and manipulating micron and submicron particles with great success in the last decades. Under tight focusing of a laser beam the optical forces that appear around the focus spot can be both repulsive (scattering force) and attractive (gradient force) towards a particle with higher refractive index than its surroundings. By proper control of these two forces a stable potential can be achieved where a particle can be trapped and manipulated in space. The ability to manipulate micro- and nanoscale matter according to our needs has opened great avenues to a variety of research areas.
  • 1.1K
  • 19 Aug 2020
Topic Review
Astrophysics
Astrophysics is the branch of astronomy that employs the principles of physics and chemistry "to ascertain the nature of the astronomical objects, rather than their positions or motions in space". Among the objects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background. Emissions from these objects are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. Because astrophysics is a very broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics. In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine the properties of dark matter, dark energy, black holes, and other celestial bodies; whether or not time travel is possible, wormholes can form, or the multiverse exists; and the origin and ultimate fate of the universe. Topics also studied by theoretical astrophysicists include Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity, special relativity, quantum and physical cosmology, including string cosmology and astroparticle physics.
  • 1.1K
  • 15 Nov 2022
Topic Review
Wearable Airbags
Fall-related injury is a common cause of mortality among the elderly. Hip fractures are especially dangerous and can even be fatal. In this study, a threshold-based preimpact fall detection algorithm was developed for wearable airbags that minimize the impact of falls on the user’s body. Acceleration sum vector magnitude (SVM), angular velocity SVM, and vertical angle, calculated using inertial data captured from an inertial measurement unit were used to develop the algorithm. To calculate the vertical angle accurately, a complementary filter with a proportional integral controller was used to minimize integration errors and the effect of external impacts. In total, 30 healthy young men were recruited to simulate 6 types of falls and 14 activities of daily life. The developed algorithm achieved 100% sensitivity, 97.54% specificity, 98.33% accuracy, and an average lead time (i.e., the time between the fall detection and the collision) of 280.25 ± 10.29 ms with our experimental data, whereas it achieved 96.1% sensitivity, 90.5% specificity, and 92.4% accuracy with the SisFall public dataset. This paper demonstrates that the algorithm achieved a high accuracy using our experimental data, which included some highly dynamic motions that had not been tested previously.
  • 1.1K
  • 01 Nov 2020
Topic Review
Radiation Portal Monitor
Radiation Portal Monitors (RPMs) are passive radiation detection devices used for the screening of individuals, vehicles, cargo or other vectors for detection of illicit sources such as at borders or secure facilities. Fear of terrorist attacks with radiological weapons spurred RPM deployment for cargo scanning since 9/11, particularly in the United States.
  • 1.1K
  • 14 Nov 2022
Topic Review
Allying Meta-Structures with Diverse Optical Waveguides for Integrated-Photonics
Recent years have witnessed tremendous interest in synergizing various functional subwavelength structures into diverse optical waveguide platforms to enable versatile photonic meta-devices. The advancement of meta-waveguides not only extends meta-optics into the manipulation of guided wave, but may also reshape the landscapes of photonic integrated circuits and massive emergent applications. A recent review paper outlined latest progress on meta-waveguides-based photonics devices and systems. Both forward and inverse designed scenarios are cataloged showcasing vibrant opportunities.
  • 1.1K
  • 13 Dec 2021
Topic Review
CMOS Sensors
Depleted Complementary Metal-Oxide-Semiconductor (CMOS) sensors are emerging as one of the main candidate technologies for future tracking detectors in high luminosity colliders. Their capability of integrating the sensing diode into the CMOS wafer hosting the front-end electronics allows for reduced noise and higher signal sensitivity, due to the direct collection of the sensor signal by the readout electronics. They are suitable for high radiation environments due to the possibility of applying high depletion voltage and the availability of relatively high resistivity substrates. The use of a CMOS commercial fabrication process leads to their cost reduction and allows faster construction of large area detectors. In this contribution, a general perspective of the state of the art of CMOS detectors for High Energy Physics experiments is given. The main developments carried out with regard to these devices in the framework of the CERN RD50 collaboration are summarized.
  • 1.1K
  • 15 Dec 2020
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