Rodriguez-Martinez M.,UAH |
Sanchez F.,Geowissenschaftliches Zentrum Gottingen |
Walliser E.O.,Geowissenschaftliches Zentrum Gottingen |
Reitner J.,Geowissenschaftliches Zentrum Gottingen
Sedimentary Geology | Year: 2012
A fine-grained stromatolite bed, laterally continuous on the kilometer scale and with small synoptic relief, crops out in the Muñecas Formation in the Northern Iberian Ranges. The Muñecas Fm. was deposited during the late Turonian on a shallow water platform in the Upper Cretaceous intracratonic Iberian basin. The stromatolite bed has a tabular to domed biostromal macrostructure. Its internal mesostructure consists of planar, wavy to hemispherical stromatoids that display a broad spectrum of microstructures, including dense micrite, bahamite peloids, peloidal to clotted microfabrics, irregular micritic-wall tubes, which are suggestive of algae and filamentous microframeworks, which are suggestive of filamentous cyanobacteria. Various stromatolite growth stages have been linked to the dominance of different accretion processes. The accretion of the entire fine-grained stromatolite involves a complex mosaic of processes: trapping and binding of quartz-silt grains and bahamites, which form the agglutinated parts of some laminae, and microbially induced precipitation, which forms spongiostromic and micritic laminae. Tubiform and filamentous microframeworks resembling porostromatate or skeletal stromatolitic growth were also recognized. Laser ICP-MS measurements of Al, Si, Mg, Mn, Sr, S and Fe were analyzed to detect the influence of siliciclastic inputs and major trends during stromatolite accretion. Carbon and oxygen isotopic compositions from the stromatolite and associated facies were used to identify possible microbial signatures. These data describes a unique and well-preserved example of a shallow marine Upper Turonian fine-grained stromatolite. © 2011 Elsevier B.V.
"The ability to extract dependable and actionable information from the vibration of machines will allow businesses to keep their assets running for longer while spending far less in maintenance. Also, the investment to get there will be just software," says Dr. Teixeira, who is the technical lead for the Health and Usage Monitoring Systems (HUMS) analytics project at UAH's Reliability and Failure Analysis Laboratory (RFAL). In blind tests using data coming from highly unpredictable and real-life situations, the algorithm consistently achieves over 90 percent accuracy, says Dr. Teixeira. "This technology is in the trial stage. We are seeing how it performs in the field. If the results so far hold, we will build credibility and hopefully gain acceptance with our Dept. of Defense partners," he says. "At the same time, we are expanding our client base to include the private sector. There, we believe we will have an even larger impact in the way they do business." Typical vibration analysis searches for anomalies in the vibration of machinery such as engines and gearboxes. These changes in vibration can signal wear and future maintenance needs long before the machinery fails. "Any machine shakes and vibrates, and it will vibrate a little differently when there is something wrong, like a fault," says Dr. Teixeira. "If you can detect a fault before it becomes serious, then you can plan ahead and reduce the time machinery spends idle in the shop. As we all know, time is money." The difficulty in extracting useful information from machinery vibration is the amount of random noise that exists in normal operating environments. Finding that useful information has been a "needle-in-a-haystack" problem. Current monitoring algorithms assume that vibrations are static and that signal and noise can be differentiated by frequency. "The problem is that those assumptions never hold true in real life," Dr. Teixeira says. "Instead, what we have done is to take an artificial intelligence algorithm and 'teach' it the basic principles of physics that govern faults in a vibrating environment." Dr. Teixeira's approach has provided the U.S. Army with a new way of producing actionable information from helicopter HUMS data, says Chris Sautter, RFAL director for reliability. "His approach, using machine learning, permits the analysis to look at the history of the data output rather than just a single flight. We train the algorithm much like you train your cell phone to understand your voice," Sautter says. "When the particular component we are monitoring sees vibration signatures that no longer reflect the normal performance of a component, an alert is passed to the maintenance team." The RFAL algorithm fits easily into the Condition Based Maintenance paradigm that has been adopted across the Dept. of Defense and the commercial aviation sector, Sautter says. "Having this capability and the ability to enhance the maintenance policy of large fleet operators has presented UAH and the Reliability Lab with a host of new clients for our research capabilities." Explore further: A new sensor uses sound to diagnose faults in industrial machinery
News Article | April 12, 2016
Scientists at The University of Alabama in Huntsville (UAH) are set to use computer models to investigate the results of experimental testing at NASA'S Marshall Space Flight Center in Huntsville to develop an engineering tool to design missions using a new type of long-distance space propulsion.
News Article | April 14, 2016
Next-generation spacecraft sailing to interstellar space may soon rely on harnessing solar wind to produce momentum, as scientists from NASA begin experimentations in Alabama for an advanced propulsion system. Designed for very long distance missions, NASA's HERTS E-sail technology (Heliopause Electrostatic Rapid Transit System Electric Sail) can potentially halve the time it takes for spacecraft to go into interstellar space. It could send spacecraft even to the "edge" of our solar system, known as the Heliopause, at a speed faster than ever. After initial trials are over, the University of Alabama in Huntsville (UAH) will use computer models to examine NASA's results. The E-sail propulsion system is expected to consist of at least 10 electrically charged, bare aluminum wires that radiate from the inside of the spacecraft to make a circular "E-sail." Lead E-sail engineer Bruce Wiegmann said the sun ejects electrons and protons into the solar wind at very high speeds of up to 750 kilometers per second (approx. 1.6 million miles per hour), and they will take advantage of this solar power. The E-sail's special wires are capable of electrostatically repelling rapid-moving protons of the solar wind, with the momentum acting as the spacecraft's thrust. Each tether would only be one millimeter (0.039 inch) thick but 20 kilometers (12.42 miles) in length. "The E-Sail would use these protons to propel the spacecraft," said Wiegmann. Spacecraft with the E-sail would be able to rotate at one revolution per hour, with centrifugal forces expanding the special wires into position. It would then be navigated by controlling each wire's voltage, changing the force applied to different portions of the propulsion. The tests at the Marshall Space Flight Center in Huntsville will try to discover the rate of electron and proton collisions with a positively charged wire. NASA's Voyager mission is currently exploring the interstellar medium. The use of the E-sail technology could become a breakthrough for these kinds of "ambitious missions," said UAH scientist Gary Zank. Astronomers expect the new propulsion system to be expeditious. Voyager 1 took 35 years to reach the Heliopause, but HERTS E-sail could do it in a shorter amount of time. Wiegmann said their investigations reveal that spacecraft with E-sail could travel to the Heliopause in just 10 years. "This could revolutionize the scientific returns of these types of missions," said Wiegmann. What's more impressive is that the propulsion system could be used for shorter missions, too. Wiegmann said the design is extremely flexible and adaptable. It could be used for missions in the Heliopause, within the inner interplanetary system, as well as on the outer interplanetary, he added. The HERTS study was funded in 2015 by the Space Technology Mission Directorate (STMD). It was one of the Phase II NASA Innovative Advanced Concepts (NIAC) projects. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.
Few of the remaining Republican presidential candidates seem very gung-ho about fighting climate change. But as we’ve written before, Texas Sen. Ted Cruz has probably made the most detailed, scientific argument for why we shouldn’t worry about it. He has repeatedly argued that climate warming is, basically, on pause — and that futhermore, this relative lack of recent warming undermines scientists’ dire predictions about where we’re heading. Based on records from satellites, there has been “no significant warming whatsoever for the last 18 years,” Cruz asserted in New Hampshire in January. That’s just one of many times he has made this claim or something close to it, which turns on looking at a particular record of the Earth’s climate — satellite readings of the atmosphere’s temperature — rather than others (such as the surface thermometer measurements that NASA and NOAA just used to declare 2015 the hottest year ever recorded). But lately, it looks like the satellites may be getting less friendly to Cruz and his argument. Two prominent satellite datasets — one from the University of Alabama in Huntsville, and the other from Remote Sensing Systems in Santa Rosa, Calif. — both show that February of 2016 was the hottest month ever recorded in the lower troposphere, a layer of the atmosphere stretching from the surface to about 6 miles in the air. Using the University of Alabama in Huntsville dataset, Roy Spencer, one of the scientists involved in the research, last week announced a record warm monthly measurement for the lower troposphere on his blog. And Remote Sensing Systems found the same thing, both for the lower and also the middle troposphere. [February was Earth’s warmest month in the satellite record] “We actually just had the hottest month ever,” said physicist Carl Mears of Remote Sensing Systems. “I really suspect that 2016 is going to be the warmest ever” out of all the years in the satellite record, he said. That record goes back to 1979. Perhaps we shouldn’t make too much of one record warm month. But what about a new satellite dataset that also shows more warming than before? Mears and his colleague Frank Wentz just published a new paper in the Journal of Climate, a publication of the American Meteorological Society, detailing a new correction to their satellite temperature dataset for the middle troposphere (from the surface to roughly 50,000 feet in the air). The correction was necessary because of a long-standing problem with data derived from polar orbiting satellites — as they circle the globe from top to bottom, they tend to drift. “It might have started out its mission measuring at 2:00 in the afternoon, but years later, it’s drifted, so it’s now 6:00 in the afternoon. And most places, it’s not as warm at 6:00 as it is at 2:00,” Mears said. Moreover, there was no way of independently checking whether the satellites were actually measuring the right temperature 8 kilometers into the atmosphere over the equator, Mears said. There are no hovering thermometers there. Previously, his team had tried to correct the problem by using a climate model to estimate that temperature, but the method was “not sufficiently accurate,” according to the new study. So now, a new correction has been applied, and the result is that the satellite record kept by Remote Sensing Systems shows more global warming than before. [What these ancient shipwrecks could be telling us about climate change] Specifically, Mears said, the prior dataset had shown about a 0.08 degree Celsius warming trend per decade for the middle troposphere, whereas the new one shows a 0.133 degree Celsius trend. Moreover, over the past 18 years that Cruz likes to cite — the period since 1998, a record warm El Nino year that officially remains the hottest year in the satellite record — there’s now also a trend, despite the fact that starting an analysis with this super-hot year tends to mute it. “The trend, 1998 to the present, used to be slightly negative,” Mears said. “And now it’s about .06. So this adjustment I made is, it ended up having a larger effect after 1998 than it did before 1998, just because of the pattern of how the satellites drift, and that sort of thing.” So based on Mears’ dataset, it would now appear tougher to argue that there is no warming since 1998 in the satellite record. Granted, Mears said that Remote Sensing Systems has not yet applied this correction to the data for the lower troposphere (from the surface to about 35,000 feet), an often-cited dataset. Asked for a response to the new study, Cruz’s communications director Rachael Slobodien said, “Isn’t it convenient that alarmists keep revising data that is inconvenient? The data showed a pause, so instead of revising the theory, they revised the data.” As this comment suggests, skeptics like Cruz still have counterarguments they can make. This new data update does not mean that the warming shown by satellites is as fast as the warming shown by ground-based thermometer and ocean surface measurements, for instance. Nor does it mean that the warming shown by satellites matches what climate change models predict. It still lags those predictions, according to Mears. So as Slobodien’s words suggest, Cruz and his supporters can still argue that the “theory” and the “data” are misaligned. And finally, it is important to note that the satellite researchers at the University of Alabama in Huntsville, John Christy and Roy Spencer, aren’t necessarily sold on the new correction by Remote Sensing Systems. Spencer has posted a blog post critiquing it – suggesting that it may have introduced “spurious warming.” So Cruz could still continue to cite the Alabama dataset. Indeed, Christy explained by email that for the middle troposphere, his data still don’t show much of a warming trend since 1998. Nor do they show one for the lower troposphere, which Christy calls the “popular” dataset — and which Remote Sensing Systems has not corrected yet. “UAH has a trend of -0.006 and current RSS is -0.014 – basically zero in both cases. 1998 was really warm in the satellite datasets,” said Christy by email, referring to measurements of the lower troposphere. So some debates will surely continue, but the fact remains: The world is setting staggering heat records right now, including in the satellite record. And the claim that satellites don’t show any recent warming has already been widely critiqued by climate scientists as a form of cherry-picking. Now, it’s been called even more into question. “This is definitely an advance,” said Mears. “This is how the scientific process works. You do something, you continue to evaluate it, you see something that might be wrong, and then you fix that something.” China vowed to peak emissions by 2030. It could be way ahead of schedule Greenland’s melting is ‘feeding on itself,’ scientists say For more, you can sign up for our weekly newsletter here, and follow us on Twitter here.