Flood risks: More accurate data due to COVID-19

Emerging use of Global Navigation Satellite System (GNSS) makes it possible to continuously measure shallow changes in elevation of Earth surface. A study by the University of Bonn now shows that the quality of these measurements may have improved significantly during the pandemic, at least at some stations. The results show which factors should be considered in the future when installing GPS antennas. More precise geodetic data are important for assessing flood risks and for improving earthquake early warning systems. The journal Geophysical Research Letters now reports on this.

A number of countries went into politically decreed late hibernation at the onset of the Covid-19 pandemic. Many of those affected by the lockdown suffered negative economic and social consequences. Geodesy, a branch of the Earth Science to study Earth’s gravity field and its shape, on the other hand, has benefited from the drastic reduction in human activity. At least that is what the study now published in the Geophysical Research Letters shows. The study, which was carried out by geodesists from the University of Bonn, investigated the location of a precise GNSS antenna in Boston (Massachusetts) as an example.

GNSS receivers can determine their positions to an accuracy of a few mm. They do this using the US GPS satellites and their Russian counterparts, GLONASS. For some years now, it has also been possible to measure the distance between the antenna and the ground surface using a new method. “This has recently allowed our research group to measure elevation changes in the uppermost of soil layers, without installing additional equipment,” explains Dr. Makan Karegar from the Institute of Geodesy and Geoinformation at the University of Bonn. Researchers, for instance, can measure the wave-like propagation of an earthquake and the rise or fall of a coastal area.

The measuring method is based on the fact that the antenna does not only pick up the direct satellite signal. Part of the signal is reflected by the nearby environment and objects and reaches the GNSS antenna with some delays. This reflected part therefore travels a longer path to the antenna. When superimposed on the directly received signal, it forms certain patterns called interference. The can be used to calculate the distance between the antenna and the ground surface which can change over time. To calculate the risk of flooding in low-elevation coastal areas, it is important to know this change — and thus the subsidence of the Earth surface — precisely.

This method works well if the surrounding ground is flat, like the surface of a mirror. “But many GNSS receivers are mounted on buildings in cities or in industrial zones,” explains Prof. Dr. Jürgen Kusche. “And they are often surrounded by large parking lots — as is the case with the antenna we investigated in Boston.”

Cars cause disturbance

In their analysis, the researchers were able to show that parked cars significantly reduce the quality of the elevation data: Parked vehicles scatter the satellite signal and cause it to be reflected several times before it reaches the antenna, like a cracked mirror. This not only reduces the signal intensity, but also the information that can be extracted from it: It’s “noisy.” In addition, because the “pattern” of parked cars changes from day to day, these data can not be easily corrected.

“Before the pandemic, measurements of antenna height had an average accuracy of about four centimeters due to the higher level of noise,” says Karegar. “During the lockdown, however, there were almost no vehicles parked in the vicinity of the antenna; this improved the accuracy to about two centimeters.” A decisive leap: The more reliable the values, the smaller the elevation fluctuations that can be detected in the upper soil layers.

In the past, GNSS stations were preferably installed in sparsely populated regions, but this has changed in recent years. “Precise GNSS sensors are often installed in urban areas to support positioning services for engineering and surveying applications, and eventually for scientific applications such as deformation studies and natural hazards assessment,” says Karegar. “Our study recommends that we should try to avoid installation of GNNS sensors next to parking lots.”

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Materials provided by University of Bonn. Note: Content may be edited for style and length.

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UV-C light is effective for killing COVID-19 on N95s, study demonstrates

Dermatology researchers at Henry Ford Health System, in collaboration with a team at the University of Michigan, have demonstrated that certain N95 respirators tainted with COVID-19 can be effectively and safely decontaminated for reuse using ultraviolet-C light (UV-C), a method commonly utilized for treating rare skin diseases.

Researchers say the outside and inside of the facemasks were decontaminated in a prototype phototherapy unit that dispenses a UV-C dosing level high enough to effectively kill the virus in less than two minutes while still preserving the facemask’s breathability, fit and overall integrity.

Of the five N95s used at Henry Ford and tested for the coronavirus in the study, the decontamination process worked best on two models — facepieces on 3M 1860 and Moldex 1511 and straps on 3M 8210 and Moldex 1511. The effects of the dosage varied on the other tested models and their straps, suggesting that the UV-C radiation can degrade them. Researchers say wiping the straps with ethanol before decontamination would likely be required as an additional disinfection step in the process to maximize the wearer’s safety.

Researchers emphasized that fit testing be required each time a disinfected facemask is returned for use or a new model is being worn for the first time.

The research, conducted in partnership with the University of Michigan, is published in the International Journal of Infectious Diseases.

“Our findings reveal a practical, and viable option should hospitals encounter shortages of N95s in the future,” says David Ozog, M.D., chair of Henry Ford’s Department of Dermatology in Detroit and the study’s lead author. “Using UV-C has been shown to be effective in killing other coronaviruses and the flu virus. We were able to replicate that sterilization effectiveness with COVID-19.”

Ozog stressed that facemask sterilization should only be used in severe shortages of N95s.

Testing of the N95s for decontamination was performed at U-M’s SARS-CoV-2 research lab in Ann Arbor.

“When Dr. Ozog approached us about helping to demonstrate the effectiveness of their UV sterilization procedure with live SARS-CoV-2 virus, we immediately agreed and understood that we could provide some confidence to their healthcare workers that this procedure was effective,” says Jonathan Sexton, Ph.D., assistant professor of Internal Medicine and director of the U-M Center for Drug Repurposing and a study co-author.

The research culminated the work of a team of dermatologists and researchers who have devoted more than 400 hours since the pandemic hit Michigan to investigating how phototherapy — a type of medical treatment used for treating certain skin conditions — could serve a role in the global health emergency. The Henry Ford team includes Henry Lim, M.D., and Iltefat Hamzavi, M.D., both of whom are internationally recognized for their expertise using phototherapy for treating rare skin diseases like vitiligo and hidradenitis suppurativa.

The team’s focus centered on the potential of decontamination contaminated N95s for reuse by healthcare workers. They examined the reliability of the prototype unit and ultraviolet light, the minimum dosage needed for decontamination, the importance of fit testing post-decontamination and four common methods associated with facemask decontamination.

The pandemic exposed a critical flaw in the global PPE supply chain as the health care industry struggled to obtain supplies of N95s, other facemask types, gowns, gloves and face shields. As a result, decontaminating N95s to be reused safely became essential for many health care systems and providers until new shipments of supplies arrived. Henry Ford decontaminated thousands of N95s and returned them to their user for reuse in the first couple months of the pandemic.

“The beginning of the pandemic was physically and mentally overwhelming for everyone. We desperately wanted to help our front-line workers, who were crushed with COVID-19 cases at Henry Ford,” Dr. Ozog says.

UV-C is one of the four methods considered for facemask decontamination. It is well known for its ability to penetrate the DNA of bacteria and microorganisms and prevent them from multiplying or replicating. Previous research has shown UV-C to be effective at killing the flu virus as well two other well- known coronaviruses: severe acute respiratory syndrome (SARS-CoV) and Middle East respiratory syndrome (MERS-CoV). Whether it could work on the novel COVID-19 virus was previously unknown.

Henry Ford’s phototherapy unit was modified with the help of engineers at Daavlin Co., a phototherapy manufacturer based in Bryan, Ohio. It sits on a flat surface and is about five feet long. The decontamination field measures 15 inches deep by 45 inches long — plenty room to treat up to 27 facemasks at one time. The ultraviolet light is powered by at least 10 but not more than 20 UV-C lamps.

For the study, five types of N95s used at Henry Ford were tested at the U-M BSL3 biosafety lab. The respirators were contaminated with four drops of the COVID-19 virus taken from viral stocks obtained from the federal government’s Biodefense and Emergency Infections Research Resources Repository. The virus droplets were placed in four areas: nosepiece, apex, chin and strap.

The facemasks were kept dry in a biosafety cabinet at room temperature for 40 minutes. Then they were moved to the phototherapy unit for decontamination using a dose of 1.5 J/cm2 ultraviolet light radiation — at a wavelength of 254 nanometers — to each side of the mask for about 60 seconds. Ultraviolet radiation is measured in three wavelengths: UV-C, UV-B and UV-A. UV-B and UV-A are associated with skin cancer and are also used in the treatment of some dermatologic diseases such as vitiligo and psoriasis.

Indermeet Kohli, Ph.D, a Henry Ford dermatology physicist, developed a formula by which the UV-C dose delivered to the exterior and interior parts of the facemasks can be assessed for decontamination and safe use. She says the curvature of the facemask and the distance between its surface and the lamps are crucial factors in achieving the proper dosage.

“It is imperative that this type of assessment be performed to make sure that the decontamination process is done properly,” Dr. Kohli says. “Failure to do so could result in catastrophic consequences for the front-line healthcare workers.”

The effectiveness of decontamination was measured in analytical chemistry terms by the limit of detection (LOD) and no cytopathic effect (CPE). LOD is the minimum concentration of a component that can be reliably detected. CPE means the virus yielded no infectious properties.

All five facepieces had below LOD and no CPE but some had traces of the virus on their straps, according to the research.

Researchers cautioned that none of the N95s tested were visibly soiled. Most health systems including Henry Ford prohibit the reuse of soiled N95s.

In a Letter to the Editor published in Photodermatology, Photoimmunology & Photomedicine, Shanthi Narla, M.D., a Henry Ford dermatology fellow, urged caution about using UV-C decontamination due to the variety of N95s in use across the country. “This process should only be considered as a risk mitigation effort during severe shortages,” she wrote.

In a demonstration of the prototype unit, the facemasks are placed on a stainless-steel tray, separated by autoclave tape to keep them from touching each other. Once one side of the facemask is treated, it’s flipped over to perform a separate decontamination. Researchers say any visibly soiled masks should not be treated but rather properly disposed as medical waste.

“Considering that many healthcare providers are using substitutes for N95s that offer very limited degree of protection, using (UV-C) and repurposing phototherapy devices could be the best practical solution at this time,” Dr. Hamzavi wrote in Letter to the Editor published online in JAAD.

Researchers stressed that not all N95s are created equal and may not withstand decontamination. Degrading may occur in the facemask’s outer surface and the elasticity of the bands. Thus, researchers underscored the importance of fit-testing after decontamination in a study published in the Journal of the American Academy of Dermatology. Health care workers are fit-tested every year with their N95 to ensure a proper fit and no air can penetrate the outer edges.

UV-C is one of the four common methods used in health care to sterilize N95s. Hydrogen peroxide vaporization, microwave generated steaming and dry heating also have shown to be effective in varying degrees. UV-C and HPV are also commonly used for disinfecting patient care units, surgical suites and intensive care units in the health care setting. Only the UV-C method was used in the Henry Ford study.

Researchers strike a cautionary tone for N95 decontamination no matter the method.

“Given the current COVID-19 pandemic, extreme measures are needed to keep those on the front line protected,” says Angela Torres, M.D., a Henry Ford dermatology fellow and lead author in a study published online in Photochemical & Photobiological Sciences. “These options are cost effective, quick to employ and have the potential to save many lives and valuable resources.”

However, Dr. Torres says, discarding a contaminated disposable N95 after a single use is “still ideal.”

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Modern theory from ancient impacts

Around 4 billion years ago, the solar system was far less hospitable than we find it now. Many of the large bodies we know and love were present, but probably looked considerably different, especially the Earth. We know from a range of sources, including ancient meteorites and planetary geology, that around this time there were vastly more collisions between, and impacts from, asteroids originating in the Mars-Jupiter asteroid belt.

Knowledge of these events is especially important to us, as the time period in question is not only when the surface of our planet was taking on a more recognizable form, but was also when life was just getting started. With more accurate details of Earth’s rocky history, it could help researchers answer some long-standing questions concerning the mechanisms responsible for life, as well as provide information for other areas of life science.

“Meteorites provide us with the earliest history of ourselves,” said Professor Yuji Sano from the Atmosphere and Ocean Research Institute at the University of Tokyo. “This is what fascinated me about them. By studying properties, such as radioactive decay products, of meteorites that fell to Earth, we can deduce when they came and where they came from. For this study we examined meteorites that came from Vesta, the second-largest asteroid after the dwarf planet Ceres.”

Sano and his team found evidence that Vesta was hit by multiple impacting bodies around 4.4 billion to 4.15 billion years ago. This is earlier than 3.9 billion years ago, which is when the late heavy bombardment (LHB) is thought to have occurred. Current evidence for the LHB comes from lunar rocks collected during the Apollo moon missions of the 1970s, as well as other sources. But these new studies are improving upon previous models and will pave the way for an up-to-date database of early solar impact records.

“That Vesta-origin meteorites clearly show us impacts earlier than the LHB raises the question, ‘Did the late heavy bombardment truly occur?'” said Sano. “It seems to us that early solar system impacts peaked sooner than the LHB and reduced smoothly with time. It may not have been the cataclysmic period of chaos that current models describe.”

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Materials provided by University of Tokyo. Note: Content may be edited for style and length.

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Surprising number of exoplanets could host life

Our solar system has one habitable planet — Earth. A new study shows other stars could have as many as seven Earth-like planets in the absence of a gas giant like Jupiter.

This is the conclusion of a study led by UC Riverside astrobiologist Stephen Kane published this week in the Astronomical Journal.

The search for life in outer space is typically focused on what scientists call the “habitable zone,” which is the area around a star in which an orbiting planet could have liquid water oceans — a condition for life as we know it.

Kane had been studying a nearby solar system called Trappist-1, which has three Earth-like planets in its habitable zone.

“This made me wonder about the maximum number of habitable planets it’s possible for a star to have, and why our star only has one,” Kane said. “It didn’t seem fair!”

His team created a model system in which they simulated planets of various sizes orbiting their stars. An algorithm accounted for gravitational forces and helped test how the planets interacted with each other over millions of years.

They found it is possible for some stars to support as many as seven, and that a star like our sun could potentially support six planets with liquid water.

“More than seven, and the planets become too close to each other and destabilize each other’s orbits,” Kane said.

Why then does our solar system only have one habitable planet if it is capable of supporting six? It helps if the planets’ movement is circular rather than oval or irregular, minimizing any close contact and maintain stable orbits.

Kane also suspects Jupiter, which has a mass two-and-a-half times that of all the other planets in the solar system combined, limited our system’s habitability.

“It has a big effect on the habitability of our solar system because it’s massive and disturbs other orbits,” Kane said.

Only a handful of stars are known to have multiple planets in their habitable zones. Moving forward, Kane plans to search for additional stars surrounded entirely by smaller planets. These stars will be prime targets for direct imaging with NASA telescopes like the one at Jet Propulsion Laboratory’s Habitable Exoplanet Observatory.

Kane’s study identified one such star, Beta CVn, which is relatively close by at 27 light years away. Because it doesn’t have a Jupiter-like planet, it will be included as one of the stars checked for multiple habitable zone planets.

Future studies will also involve the creation of new models that examine the atmospheric chemistry of habitable zone planets in other star systems.

Projects like these offer more than new avenues in the search for life in outer space. They also offer scientists insight into forces that might change life on our own planet one day.

“Although we know Earth has been habitable for most of its history, many questions remain regarding how these favorable conditions evolved with time, and the specific drivers behind those changes,” Kane said. “By measuring the properties of exoplanets whose evolutionary pathways may be similar to our own, we gain a preview into the past and future of this planet — and what we must do to main its habitability.”

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Materials provided by University of California – Riverside. Original written by Jules Bernstein. Note: Content may be edited for style and length.

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How stony-iron meteorites form

Meteorites give us insight into the early development of the solar system. Using the SAPHiR instrument at the Research Neutron Source Heinz Maier-Leibnitz (FRM II) at the Technical University of Munich (TUM), a scientific team has for the first time simulated the formation of a class of stony-iron meteorites, so-called pallasites, on a purely experimental basis.

“Pallasites are the optically most beautiful and unusual meteorites,” says Dr. Nicolas Walte, the first author of the study, in an enthusiastic voice. They belong to the group of stony-iron meteorites and comprise green olivine crystals embedded in nickel and iron. Despite decades of research, their exact origins remained shrouded in mystery.

To solve this puzzle, Dr. Nicolas Walte, an instrument scientist at the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching, together with colleagues from the Bavarian Geoinstitute at the University of Bayreuth and the Royal Holloway University of London, investigated the pallasite formation process. In a first, they succeeded in experimentally reproducing the structures of all types of pallasites.

Deployment of the SAPHiR instrument

For its experiments, the team used the SAPHiR multi-anvil press which was set up under the lead of Prof. Hans Keppler of the Bavarian Geoinstitute at the MLZ and the similar MAVO press in Bayreuth. Although neutrons from the FRM II have not yet been fed into SAPHiR, experiments under high pressures and at high temperatures can already be performed.

“With a press force of 2400 tons, SAPHiR can exert a pressure of 15 gigapascals (GPa) on samples at over 2000 °C,” explains Walte. “That is double the pressures needed to convert graphite into diamond.” To simulate the collision of two celestial bodies, the research team required a pressure of merely 1 GPa at 1300 °C.

How are pallasites formed?

Until recently, pallasites were believed to form at the boundary between the metallic core and the rocky mantle of asteroids. According to an alternative scenario, pallasites form closer to the surface after the collision with another celestial body. During the impact molten iron from the core of the impactor mingles with the olivine-rich mantle of the parent body.

The experiments carried out have now confirmed this impact hypothesis. Another prerequisite for the formation of pallasites is that the iron core and rocky mantle of the asteroid have partially separated beforehand.

All this happened shortly after their formation about 4.5 billion years ago. During this phase, the asteroids heated up until the denser metallic components melted and sank to the center of the celestial bodies.

The key finding of the study is that both processes — the partial separation of core and mantle, and the subsequent impact of another celestial body — are required for pallasites to form.

Insights into the origins of the solar system

“Generally, meteorites are the oldest directly accessible constituents of our solar system. The age of the solar system and its early history are inferred primarily from the investigation of meteorites,” explains Walte.

“Like many asteroids, the Earth and moon are stratified into multiple layers, consisting of core, mantle and crust,” says Nicolas Walte. “In this way, complex worlds were created through the agglomeration of cosmic debris. In the case of the Earth, this ultimately laid the foundations for the emergence of life.”

The high-pressure experiments and the comparison with pallasites highlight significant processes that occurred in the early solar system. The team’s experiments provide new insights into the collision and material mixing of two celestial bodies and the subsequent rapid cooling down together. This will be investigated in more detail in future studies.

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Expert System Launches Natural Language API for Semantic Analysis

Expert System, a company that provides semantic intelligence products, has released a new natural language API that is intended to support data scientists, computational linguists, and knowledge engineers. The new NL APITrack this API is cloud-based and provides developers with natural language understanding/processing capabilities.

In the announcement of the product, Expert System noted that they created the new API by:

“…leveraging AI-based algorithms, machine learning, and knowledge graph to provide advanced features for reading and understanding any text, out of the box.”

The API provides a feature set that includes deep linguistic analysis, syntactic analysis, word sense disambiguation, named entity recognition and linking, and document classification. Developers can test the API for free and the company is providing documentation and a new developer portal

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Author: <a href="">KevinSundstrom</a>

3D Printing Industry

E3D launches subtractive toolhead for desktop hybrid manufacturing

Leading hotend manufacturer E3D has launched a new subtractive toolhead for use with its Motion System and ToolChanger – the ASMBL tool. The ToolChanger has been available for a year now, and allows users to automatically change toolheads mid-print. With it, the production of multi-material, multi-resolution parts is completely automated. Printheads and extruders are swapped […]

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Author: Kubi Sertoglu

3D Printing Industry

Sharebot launches the SnowWhite 2 3D printer – technical specifications and pricing

Sharebot has debuted its new SnowWhite 2 3D printer. The professional SLS system is the next iteration to the previously released SnowWhite, with improvements in temperature control and a new software engine. Being aimed primarily at SMEs and research institutions, the machine claims to provide an economical method of professional-grade polymer part production. Covering all […]

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Author: Kubi Sertoglu

3D Printing Industry

BAE Systems installs fourth Stratasys F900 3D printer in ‘Factory of the Future’ initiative

Multinational aerospace company BAE Systems has announced the installation of its fourth Stratasys F900 system, as the business continues to drive down costs as part of its ‘Factory of the Future’ initiative.  Installed at the defense contractor’s manufacturing site in Samlesbury, UK, the 3D printer will be used to produce prototypes, tooling, and end-use parts […]

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Author: Paul Hanaphy


Trill Touch Sensors – for Music and More!

Touch sensors galore! We dig into a new package from the creators of Bela, a low-latency system for audio hardware. They’ve successfully shipped all the perks for the Trill Kickstarter, and sent us one of each sensor – plus the coordinating breakout board (Craft), and a sneak peek of their upcoming I2C bus!

Some more info from our friends: the bus is "a little utility that we’re about to make available that makes it easier to daisy chain multiple Trill sensors (or any I2C devices) together. The idea is that you will connect multiple sensors to the board and then jumper from there to your Arduino, Bela, RPi or platform of choice." Sweet!


// Previously on Hackster: