Science Daily December 11, 2019 Researchers at Pennsylvania State University report on a distributed acoustic sensing (DAS) array using preexisting underground fiber optics beneath the Penn State campus for detecting and characterizing thunder‐induced ground motions. During a half‐hour interval in State College, PA, they identified 18 thunder‐induced seismic events in the DAS array data. The high‐fidelity DAS data show that the thunder‐induced seismic are very broadband, with their peak frequency ranging from 20 to 130 Hz. The dense DAS data enable them to simulate thunder‐seismic wave propagation and full waveform synthetics and further locate the thunder‐seismic source by time‐reversal migration. […]
Category Archives: Sensors
Black silicon can help detect explosives
EurekAlert November 27, 2019 Detection of nitroaromatic compounds (NAC) vapors is challenging owing to their low vapor pressure and relatively weak sensitivity of the existing detection techniques. An international team of researchers (Russia, Australia) proposes a novel concept to design fluorescence (FL) detection platforms based on chemical functionalization of nanotextured dielectric surfaces exhibiting resonant light absorption, trapping, and localization effects. They demonstrated the sensor with selective FL-quenching response from monolayers of carbazole moieties covalently bonded to a spiky silicon surface, “black” silicon. It provided unprecedented ppt (10–12) range limits of detection for several NAC vapors. The easy-to-implement scalable fabrication procedure […]
Advancing nuclear detection and inspection
MIT News November 14, 2019 Previously proposed solutions lacked the combination of isotopic sensitivity and information security. Researchers at MIT present the experimental feasibility proof of a technique that uses neutron induced nuclear resonances that is sensitive to the combination of isotopics and geometry. The information is physically encrypted to prevent the leakage of sensitive information. The approach can significantly increase the trustworthiness of future arms control treaties while expanding their scope to include the verified dismantlement of nuclear warheads themselves…read more. Open Access TECHNICAL ARTICLE
Carnegie Mellon system locates shooters using smartphone video
Eurekalert November 20, 2019 Researchers at Carnegie Mellon University have developed a system called Video Event Reconstruction and Analysis (VERA), that can accurately locate a shooter based on video recordings from as few as three smartphones. They released the code at a recent ACM International Conference on Multimedia in France. VERA uses machine learning techniques to synchronize the video feeds and calculate the position of each camera based on what that camera is seeing. The audio from the video feeds localizes the source of the gunshots. It also uses audio to identify the type of gun used, which determines bullet […]
Fingerprint test can distinguish between those who have taken or handled heroin
Science Daily November 11, 2019 An international team of researchers (UK, Ireland) has built a fingerprint drug testing technology which is now able to detect heroin, its metabolite, 6-monoacetylmorphine (6-AM) and other analytes associated with the class A drug. The technology was able to identify traces of heroin and 6-AM on drug non-users in every scenario the researchers devised – whether someone directly touched the drug, handled it and then thoroughly washed their hands, or had come into contact with heroin via shaking someone else’s hand…read more. TECHNICAL ARTICLE
Nuclear warheads? This robot can find them
EurekAlert November 12, 2019 A team of researchers in the US (Princeton Plasma Physics Laboratory, Princeton University) is developing a prototype of autonomous, three-foot rolling robots armed with smart detectors to support nuclear safeguards and verify arms-control agreements. The demonstration confirmed that the robot could detect the source of neutrons and provided data. The “inspector bot” consists of a cylinder of polyethylene plastic containing three neutron counters set 120 degrees apart and mounted on a robot with specialized wheels that enable it to move in any direction. The detectors provide high sensitivity to the energy of detected neutrons and the […]
‘Treasure trove’ of earthquake clues could be unearthed by wavy new technique
Science Daily September 24, 2019 Current rock mapping techniques use sound waves that help assess how rocks might behave when stress builds up, and how much shaking there would be in an earthquake. An international team of researchers (UK, New Zealand) have plugged current sound wave information into full waveform inversion which helps them paint a picture of the Hikurangi fault zone in unprecedented detail. They also captured the shallow faults which were responsible for the large Gisborne tsunami in 1947 — an example of a large tsunami caused by a relatively small slow slip earthquake. The researchers combined data […]
HOT SHOT findings could save defense tech developers time and money
Phys.org August 30, 2019 Having better data at an early stage of development of missile technologies could create opportunities to explore new, innovative ideas by reducing the risk of failure. By analysing HOT SHOT sounding rocket data researchers at Sandia National Laboratory found a way to improve these tests, providing an earlier, more accurate indicator of whether an experimental technology will ultimately succeed in flight. They dressed the insides of sounding rockets with pea-sized instruments that measure vibration which has produced a more complete picture of flight vibrations that is now being used to create more accurate simulations and ground […]
Researchers reveal ultra-fast bomb detection method that could upgrade airport security
EurekAlert August 29, 2019 Paper spray mass spectrometry is a rapid and sensitive tool for explosives detection but so far it has only been demonstrated using high resolution mass spectrometry, which bears too high a cost for many practical applications. Researchers in the UK developed a system which uses swabbing material, they call “swab spray” to collect explosives from surfaces. Sensitive detection using swab spray will require a mass spectrometer with a mass resolving power of 4000 or more. The new detection method is able to analyse a wider range of materials than current thermal based detection systems used in […]
Ultrathin 3-D-printed films convert energy of one form into another
MIT News August 28, 2019 Piezoelectric materials produce a voltage in response to physical strain, and they respond to a voltage by physically deforming. Researchers at MIT developed an additive fabrication method to 3-D print ceramic transducers about 100 nanometers thin at room temperature. The films resonate at around 5 gigahertz, which is high enough for high-performance biosensors. The raw material used in 3-D printing — contains zinc oxide nanoparticles mixed with some inert solvents, which forms into a piezoelectric material when printed onto a substrate and dried. The researchers are currently working with colleagues to make piezoelectric biosensors to […]