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News Article | May 9, 2017
Site: www.scientificamerican.com

MESA, Arizona—Since the dawn of the space age NASA and other agencies have spent billions of dollars to reconnoiter Mars—assailing it with spacecraft flybys, photo-snapping orbiters and landers nose-diving onto its surface. The odds are good, many scientists say, for the Red Planet being an extraterrestrial address for alien life—good enough to sustain decades’ worth of landing very expensive robots to ping it with radar, zap it with lasers, trundle across its terrain and scoop up its dirt. Yet against all odds (and researchers’ hopes for a watershed discovery), Mars remains a poker-faced world that holds its cards tight. No convincing signs of life have emerged. But astrobiologists continue to, quite literally, chip away at finding the truth. As the search becomes more heated (some would say more desperate), scientists are entertaining an ever-increasing number of possible explanations for Martian biology as a no-show. For example, could there be a “cover up” whereby the harsh Martian environment somehow obliterates all biosignatures—all signs of past or present life? Or perhaps life there is just so alien its biosignatures are simply unrecognizable to us, hidden in plain view. Of course, the perplexing quest to find life on Mars may have a simple solution: It’s not there, and never was. But as the proceedings of this year’s Astrobiology Science Conference held here in April made clear, life-seeking scientists are not giving up yet. Instead, they are getting more creative, proposing new strategies and technologies to shape the next generation of Mars exploration. Talk about looking for Martians and you inevitably talk about water, the almost-magical liquid that sustains all life on Earth and seems to have served as an indispensable kick-starter for biology in our planet’s deepest past. “It all started out with ‘follow the water;’ not necessarily ‘follow the life’…but ‘follow one of the basic requirements for living systems,’” says Arizona State University geologist Jack Farmer, referring to NASA’s oft-repeated mantra for Martian exploration. “There are many indications of water on Mars in the past, perhaps reservoirs of water in the near subsurface as well,” he says. “But what is the quality of that water? Is it really salty—too salty for life?” Without liquid water, Farmer points out, one would naively think organisms cannot function. The reality may be more complex: on Earth, some resilient organisms such as tardigrades can enter a profound, almost indefinite state of hibernation when deprived of moisture, preserving their desiccated tissues but neither growing nor reproducing. It is possible, Farmer says, that Martian microbes could spend most of their time as inert spores “waiting for something good to happen,” only springing to life given the right and very rare conditions. Certain varieties of Earthly “extremophiles”—microbes that live at extremes of temperature, pressure, salinity and so on—exhibit similar behavior. Farmer says there is as yet no general consensus about the best way to go about life detection on the Red Planet. This is due in no small part to the runaway pace of progress in biotechnology, which has led to innovations such as chemistry labs shrunken down to fit on a computer chip. These technologies “have been revolutionizing the medical field, and have now started to enter into concepts for life detection on Mars,” he explains. Things move so fast that today’s best technology for finding Martian biology may be tomorrow’s laughably obsolete dead-end. But no matter how sophisticated a lab on a chip might be, it won’t deliver results if it is not sent to the right place. Farmer suspects that seriously seeking traces of life requires deep drilling on Mars. “I basically think we’re going to have to gain access to the subsurface and look for the fossil record,” he explains. But discovering a clear, unambiguous fossil biosignature on Mars would also raise a red flag. “We probably would approach the future of Mars exploration—particularly accessing habitable zones of liquid water in the deep subsurface—more cautiously, because life could still be there. So planetary protection would be taken very seriously,” he says. (“Planetary protection” is the term scientists commonly use for precautions to minimize the chance of biological contamination between worlds. Think of it not so much in terms of bug-eyed aliens running rampant on Earth but of billion-dollar robots finding “Martians” that prove to only be hardy bacterial hitchhikers imported from our own world). Like-minded about deep diving on Mars is Penelope Boston, director of the NASA Astrobiology Institute at the agency’s Ames Research Center. “That’s my bias,” she says. “Given Mars’ current state, with all the challenging surface manifestations of dryness, radiation and little atmosphere, the best hope for life still extant on Mars is subsurface.” The subsurface, she says, might also offer better chances of preserving past life—that is, of fossils, even if only of single-celled organisms. The planet’s depths hold the potential for harboring liquid water under certain circumstances, Boston thinks. But how far down might that water be? “I suspect it’s pretty far…and how we get to it, that’s a whole other kettle of fish,” she says. Over the years scientists have estimated the average depth of the planet’s possible liquid reservoirs as anywhere between tens of meters to kilometers. Then again, recent observations from orbiters have revealed mysterious dark streaks that seasonally flow down the sunlit sides of some Martian hillsides and craters. These “recurring slope lineae” could conceivably be brines of liquid water fed by aquifers very close to the surface, some researchers say. Such lingering uncertainties emerge from the indirect and scattered nature of our studies of Mars, and ensure that any argument for life there is based solely on circumstantial information, Boston notes. “Each individual piece of evidence is, on its own merits, weak,” she says. Only by amassing a diverse suite of independent measurements can a well-built case for life on Mars be made, she says: “In my opinion, we can’t make that strong case unless we push to do all of those measurements on exactly the same precise spot. We don’t do that because it’s very difficult, but it’s something to aspire to.” Despite decades of sending costly hardware to Mars, Boston believes that what is still missing is a sense of harmony between instruments, allowing them to work together to support a search for alien life. “I think that the precise requirements of a really robust claim of life at the microscopic scale require us to push on further,” she notes. Attendees at the astrobiology meeting in Arizona showcased an assortment of high-tech devices for next-generation exploration, ranging from microfluidic “life analyzers” and integrated nucleic acid extractors for studying “Martian metagenomics” to exquisitely sensitive, miniaturized organic chemistry labs for spotting tantalizing carbon compounds and minerals at microscopic scales. Missing from the mix, however, was any solid consensus on how these and other tools could all work together to provide a slam-dunk detection of life on Mars. Some scientists contend a new kind of focus is sorely needed. Perhaps the pathway to finding any Martians lurking in the planet’s nooks and crannies is to learn where exactly on Mars those potentially life-nurturing niches exist, and how they change over the course of days, months and years rather than over eons of geologic time. That is, to find homes for extant life on Mars today, researchers should probably not just be studying the planet’s long-term climate but also its day-to-day weather. “Right now we’re sort of shifting gears. Once you’ve found out that a planet is habitable, then the next question is, ‘Was there life?’—so it’s a completely different ball game,” says Nathalie Cabrol, director of the Carl Sagan Center at the SETI Institute. “On Mars you cannot look for life with the tools that have been looking for habitability of that planet,” she argues. “We should be looking for habitats and not habitable environments. You are dealing on Mars with what I call extremophile extreme environments on steroids,” she says, “and you don’t look for microbial life with telescopes from Mars orbit.” Cabrol advocates making an unprecedentedly robust, high-resolution study of environmental variability on Mars by peppering its surface with weather stations. Sooner or later telltale signs of the possible whereabouts of extant life may emerge from the resulting torrents of data. “Today’s environment on that planet is a reflection of something in the past,” she says, and planting numbers of automated stations on Mars does not need to be expensive. “This is of interest not only to astrobiology but to human exploration. The first thing you want to know is what the weather is like,” she says, adding, “Right now we’re not equipped to do this and I’m not saying it’s going to be easy to look for extant life. I’m not saying what we’re doing now is wrong. Whatever we put on the ground we are learning. But there is variability on Mars. You go up or down one meter, things change. Habitats at a microscopic level can happen at the scale of a slope. It can happen at the scale of a rock!” “I think Mars offers us the highest chance of finding life” somewhere beyond Earth, says Dirk Schulze-Makuch, a planetary scientist at Technical University of Berlin in Germany. But, like Boston and others, he maintains confirmation of life will only come from multiple “layers of proof” that have to be consistent with one another. “We really need at least four different kinds of methods,” he says. “My point is that there’s no slam-dunk. We need several instruments. You have to build a case, and right now we can do better…unless the biosignature through a microscope is waving hello.” The trouble, he adds, is that too-stringent planetary protection rules may preclude getting the evidence necessary for that proof. “We have the technology to go to places where there could be life,” he says. “But we can’t go to certain areas on Mars, like recurring slope lineae or…under patches of ice. It seems to be ridiculous.” Indeed, Schulze-Makuch speculates planetary protection may be a lost cause for Mars—or at least a misguided endeavor. It may even be that any Martian microbes are actually Earth’s long-lost cousins. Or, conversely, Mars rather than Earth is really the sole site of biogenesis in our solar system. Both scenarios are possible, considering that single-celled organisms can likely survive world-shattering impacts and the subsequent interplanetary voyages if embedded in ejected shards of rock that could fall elsewhere as meteorites. Innumerable impacts of this scale battered the solar system billions of years ago, potentially blasting biological material between neighboring worlds. On balance, Schulze-Makuch says, “the chances are higher that we are Martians.”


News Article | May 10, 2017
Site: news.mit.edu

When it comes to removing very dilute concentrations of pollutants from water, existing separation methods tend to be energy- and chemical-intensive. Now, a new method developed at MIT could provide a selective alternative for removing even extremely low levels of unwanted compounds. The new approach is described in the journal Energy and Environmental Science, in a paper by MIT postdoc Xiao Su, Ralph Landau Professor of Chemical Engineering T. Alan Hatton, and five others at MIT and at the Technical University of Darmstadt in Germany. The system uses a novel method, relying on an electrochemical process to selectively remove organic contaminants such as pesticides, chemical waste products, and pharmaceuticals, even when these are present in small yet dangerous concentrations. The approach also addresses key limitations of conventional electrochemical separation methods, such as acidity fluctuations and losses in performance that can happen as a result of competing surface reactions. Current systems for dealing with such dilute contaminants include membrane filtration, which is expensive and has limited effectiveness at low concentrations, and electrodialysis and capacitive deionization, which often require high voltages that tend to produce side reactions, Su says. These processes also are hampered by excess background salts. In the new system, the water flows between chemically treated, or “functionalized,” surfaces that serve as positive and negative electrodes. These electrode surfaces are coated with what are known as Faradaic materials, which can undergo reactions to become positively or negatively charged. These active groups can be tuned to bind strongly with a specific type of pollutant molecule, as the team demonstrated using ibuprofen and various pesticides. The researchers found that this process can effectively remove such molecules even at parts-per-million concentrations. Previous studies have usually focused on conductive electrodes, or functionalized plates on just one electrode, but these often reach high voltages that produce contaminating compounds. By using appropriately functionalized electrodes on both the positive and negative sides, in an asymmetric configuration, the researchers almost completely eliminated these side reactions. Also, these asymmetric systems allow for simultaneous selective removal of both positive and negative toxic ions at the same time, as the team demonstrated with the herbicides paraquat and quinchlorac. The same selective process should also be applied to the recovery of high-value compounds in a chemical or pharmaceutical production plant, where they might otherwise be wasted, Su says. “The system could be used for environmental remediation, for toxic organic chemical removal, or in a chemical plant to recover value-added products, as they would all rely on the same principle to pull out the minority ion from a complex multi-ion system.” The system is inherently highly selective, but in practice it would likely be designed with multiple stages to deal with a variety of compounds in sequence, depending on the exact application, Su says. “Such systems might ultimately be useful,” he sugggests, “for water purification systems for remote areas in the developing world, where pollution from pesticides, dyes, and other chemicals are often an issue in the water supply. The highly efficient, electrically operated system could run on power from solar panels in rural areas for example.” Unlike membrane-based systems that require high pressures, and other electrochemical systems that operate at high voltages, the new system works at relatively benign low voltages and pressures, Hatton says. And, he points out, in contrast to conventional ion exchange systems where release of the captured compounds and regeneration of the adsorbents would require the addition of chemicals, “in our case you can just flip a switch” to achieve the same result by switching the polarity of the electrodes. The research team has already racked up a series of honors for the ongoing development of water treatment technology, including grants from the J-WAFS Solutions and Massachusetts Clean Energy Catalyst competitions, and the researchers were the top winners last year’s MIT Water Innovation Prize. The researchers have applied for a patent on the new process. “We definitely want to implement this in the real world,” Hatton says. In the meantime, they are working on scaling up their prototype devices in the lab and improving the chemical robustness. This technique “is highly significant, as it extends the capabilities of electrochemical systems from basically nonselective toward highly selective removal of key pollutants,” says Matthew Suss, an assistant professor of mechanical engineering at Technion Institute of Technology in Israel, who was not involved in this work. “As with many emerging water purification techniques, it must still must be tested under real-world conditions and for long periods to check durability. However, the prototype system achieved over 500 cycles, which is a highly promising result.” These researchers “have systematically explored a variety of device configurations and a variety of contaminants,” says Kyle Smith, a professor of mechanical science and engineering at the University of Illinois, who also was not involved in this work. “In the process they have identified general design principles by which to achieve selective removal of contaminants. In this regard, I find Hatton and co-workers’ study to be very thorough and thoughtful. It provides a framework or paradigm for other researchers to emulate.” But, he adds, “A significant challenge that remains is the scale-up of these technologies.” The team also included Kai-Jher Tan, Johannes Elbert, and Robert R. Taylor Professor of Chemistry Timothy Jamison at MIT; and Christian Ruttiger and Markus Gallei at the Technical University of Darmstadt. The work was supported by a seed grant from the Abdul Latif Jameel World Water and Food Security Lab (J-WAFS) at MIT.


News Article | May 11, 2017
Site: www.rdmag.com

When it comes to removing very dilute concentrations of pollutants from water, existing separation methods tend to be energy- and chemical-intensive. Now, a new method developed at MIT could provide a selective alternative for removing even extremely low levels of unwanted compounds. The new approach is described in the journal Energy and Environmental Science, in a paper by MIT postdoc Xiao Su, Ralph Landau Professor of Chemical Engineering T. Alan Hatton, and five others at MIT and at the Technical University of Darmstadt in Germany. The system uses a novel method, relying on an electrochemical process to selectively remove organic contaminants such as pesticides, chemical waste products, and pharmaceuticals, even when these are present in small yet dangerous concentrations. The approach also addresses key limitations of conventional electrochemical separation methods, such as acidity fluctuations and losses in performance that can happen as a result of competing surface reactions. Current systems for dealing with such dilute contaminants include membrane filtration, which is expensive and has limited effectiveness at low concentrations, and electrodialysis and capacitive deionization, which often require high voltages that tend to produce side reactions, Su says. These processes also are hampered by excess background salts. In the new system, the water flows between chemically treated, or “functionalized,” surfaces that serve as positive and negative electrodes. These electrode surfaces are coated with what are known as Faradaic materials, which can undergo reactions to become positively or negatively charged. These active groups can be tuned to bind strongly with a specific type of pollutant molecule, as the team demonstrated using ibuprofen and various pesticides. The researchers found that this process can effectively remove such molecules even at parts-per-million concentrations. Previous studies have usually focused on conductive electrodes, or functionalized plates on just one electrode, but these often reach high voltages that produce contaminating compounds. By using appropriately functionalized electrodes on both the positive and negative sides, in an asymmetric configuration, the researchers almost completely eliminated these side reactions. Also, these asymmetric systems allow for simultaneous selective removal of both positive and negative toxic ions at the same time, as the team demonstrated with the herbicides paraquat and quinchlorac. The same selective process should also be applied to the recovery of high-value compounds in a chemical or pharmaceutical production plant, where they might otherwise be wasted, Su says. “The system could be used for environmental remediation, for toxic organic chemical removal, or in a chemical plant to recover value-added products, as they would all rely on the same principle to pull out the minority ion from a complex multi-ion system.” The system is inherently highly selective, but in practice it would likely be designed with multiple stages to deal with a variety of compounds in sequence, depending on the exact application, Su says. “Such systems might ultimately be useful,” he sugggests, “for water purification systems for remote areas in the developing world, where pollution from pesticides, dyes, and other chemicals are often an issue in the water supply. The highly efficient, electrically operated system could run on power from solar panels in rural areas for example.” Unlike membrane-based systems that require high pressures, and other electrochemical systems that operate at high voltages, the new system works at relatively benign low voltages and pressures, Hatton says. And, he points out, in contrast to conventional ion exchange systems where release of the captured compounds and regeneration of the adsorbents would require the addition of chemicals, “in our case you can just flip a switch” to achieve the same result by switching the polarity of the electrodes. The research team has already racked up a series of honors for the ongoing development of water treatment technology, including grants from the J-WAFS Solutions and Massachusetts Clean Energy Catalyst competitions, and the researchers were the top winners last year’s MIT Water Innovation Prize. The researchers have applied for a patent on the new process. “We definitely want to implement this in the real world,” Hatton says. In the meantime, they are working on scaling up their prototype devices in the lab and improving the chemical robustness. This technique “is highly significant, as it extends the capabilities of electrochemical systems from basically nonselective toward highly selective removal of key pollutants,” says Matthew Suss, an assistant professor of mechanical engineering at Technion Institute of Technology in Israel, who was not involved in this work. “As with many emerging water purification techniques, it must still must be tested under real-world conditions and for long periods to check durability. However, the prototype system achieved over 500 cycles, which is a highly promising result.” These researchers “have systematically explored a variety of device configurations and a variety of contaminants,” says Kyle Smith, a professor of mechanical science and engineering at the University of Illinois, who also was not involved in this work. “In the process they have identified general design principles by which to achieve selective removal of contaminants. In this regard, I find Hatton and co-workers’ study to be very thorough and thoughtful. It provides a framework or paradigm for other researchers to emulate.” But, he adds, “A significant challenge that remains is the scale-up of these technologies.”


News Article | May 11, 2017
Site: www.rdmag.com

When it comes to removing very dilute concentrations of pollutants from water, existing separation methods tend to be energy- and chemical-intensive. Now, a new method developed at MIT could provide a selective alternative for removing even extremely low levels of unwanted compounds. The new approach is described in the journal Energy and Environmental Science, in a paper by MIT postdoc Xiao Su, Ralph Landau Professor of Chemical Engineering T. Alan Hatton, and five others at MIT and at the Technical University of Darmstadt in Germany. The system uses a novel method, relying on an electrochemical process to selectively remove organic contaminants such as pesticides, chemical waste products, and pharmaceuticals, even when these are present in small yet dangerous concentrations. The approach also addresses key limitations of conventional electrochemical separation methods, such as acidity fluctuations and losses in performance that can happen as a result of competing surface reactions. Current systems for dealing with such dilute contaminants include membrane filtration, which is expensive and has limited effectiveness at low concentrations, and electrodialysis and capacitive deionization, which often require high voltages that tend to produce side reactions, Su says. These processes also are hampered by excess background salts. In the new system, the water flows between chemically treated, or “functionalized,” surfaces that serve as positive and negative electrodes. These electrode surfaces are coated with what are known as Faradaic materials, which can undergo reactions to become positively or negatively charged. These active groups can be tuned to bind strongly with a specific type of pollutant molecule, as the team demonstrated using ibuprofen and various pesticides. The researchers found that this process can effectively remove such molecules even at parts-per-million concentrations. Previous studies have usually focused on conductive electrodes, or functionalized plates on just one electrode, but these often reach high voltages that produce contaminating compounds. By using appropriately functionalized electrodes on both the positive and negative sides, in an asymmetric configuration, the researchers almost completely eliminated these side reactions. Also, these asymmetric systems allow for simultaneous selective removal of both positive and negative toxic ions at the same time, as the team demonstrated with the herbicides paraquat and quinchlorac. The same selective process should also be applied to the recovery of high-value compounds in a chemical or pharmaceutical production plant, where they might otherwise be wasted, Su says. “The system could be used for environmental remediation, for toxic organic chemical removal, or in a chemical plant to recover value-added products, as they would all rely on the same principle to pull out the minority ion from a complex multi-ion system.” The system is inherently highly selective, but in practice it would likely be designed with multiple stages to deal with a variety of compounds in sequence, depending on the exact application, Su says. “Such systems might ultimately be useful,” he sugggests, “for water purification systems for remote areas in the developing world, where pollution from pesticides, dyes, and other chemicals are often an issue in the water supply. The highly efficient, electrically operated system could run on power from solar panels in rural areas for example.” Unlike membrane-based systems that require high pressures, and other electrochemical systems that operate at high voltages, the new system works at relatively benign low voltages and pressures, Hatton says. And, he points out, in contrast to conventional ion exchange systems where release of the captured compounds and regeneration of the adsorbents would require the addition of chemicals, “in our case you can just flip a switch” to achieve the same result by switching the polarity of the electrodes. The research team has already racked up a series of honors for the ongoing development of water treatment technology, including grants from the J-WAFS Solutions and Massachusetts Clean Energy Catalyst competitions, and the researchers were the top winners last year’s MIT Water Innovation Prize. The researchers have applied for a patent on the new process. “We definitely want to implement this in the real world,” Hatton says. In the meantime, they are working on scaling up their prototype devices in the lab and improving the chemical robustness. This technique “is highly significant, as it extends the capabilities of electrochemical systems from basically nonselective toward highly selective removal of key pollutants,” says Matthew Suss, an assistant professor of mechanical engineering at Technion Institute of Technology in Israel, who was not involved in this work. “As with many emerging water purification techniques, it must still must be tested under real-world conditions and for long periods to check durability. However, the prototype system achieved over 500 cycles, which is a highly promising result.” These researchers “have systematically explored a variety of device configurations and a variety of contaminants,” says Kyle Smith, a professor of mechanical science and engineering at the University of Illinois, who also was not involved in this work. “In the process they have identified general design principles by which to achieve selective removal of contaminants. In this regard, I find Hatton and co-workers’ study to be very thorough and thoughtful. It provides a framework or paradigm for other researchers to emulate.” But, he adds, “A significant challenge that remains is the scale-up of these technologies.”


News Article | May 10, 2017
Site: phys.org

The new approach is described in the journal Energy and Environmental Science, in a paper by MIT postdoc Xiao Su, Ralph Landau Professor of Chemical Engineering T. Alan Hatton, and five others at MIT and at the Technical University of Darmstadt in Germany. The system uses a novel method, relying on an electrochemical process to selectively remove organic contaminants such as pesticides, chemical waste products, and pharmaceuticals, even when these are present in small yet dangerous concentrations. The approach also addresses key limitations of conventional electrochemical separation methods, such as acidity fluctuations and losses in performance that can happen as a result of competing surface reactions. Current systems for dealing with such dilute contaminants include membrane filtration, which is expensive and has limited effectiveness at low concentrations, and electrodialysis and capacitive deionization, which often require high voltages that tend to produce side reactions, Su says. These processes also are hampered by excess background salts. In the new system, the water flows between chemically treated, or "functionalized," surfaces that serve as positive and negative electrodes. These electrode surfaces are coated with what are known as Faradaic materials, which can undergo reactions to become positively or negatively charged. These active groups can be tuned to bind strongly with a specific type of pollutant molecule, as the team demonstrated using ibuprofen and various pesticides. The researchers found that this process can effectively remove such molecules even at parts-per-million concentrations. Previous studies have usually focused on conductive electrodes, or functionalized plates on just one electrode, but these often reach high voltages that produce contaminating compounds. By using appropriately functionalized electrodes on both the positive and negative sides, in an asymmetric configuration, the researchers almost completely eliminated these side reactions. Also, these asymmetric systems allow for simultaneous selective removal of both positive and negative toxic ions at the same time, as the team demonstrated with the herbicides paraquat and quinchlorac. The same selective process should also be applied to the recovery of high-value compounds in a chemical or pharmaceutical production plant, where they might otherwise be wasted, Su says. "The system could be used for environmental remediation, for toxic organic chemical removal, or in a chemical plant to recover value-added products, as they would all rely on the same principle to pull out the minority ion from a complex multi-ion system." The system is inherently highly selective, but in practice it would likely be designed with multiple stages to deal with a variety of compounds in sequence, depending on the exact application, Su says. "Such systems might ultimately be useful," he sugggests, "for water purification systems for remote areas in the developing world, where pollution from pesticides, dyes, and other chemicals are often an issue in the water supply. The highly efficient, electrically operated system could run on power from solar panels in rural areas for example." Unlike membrane-based systems that require high pressures, and other electrochemical systems that operate at high voltages, the new system works at relatively benign low voltages and pressures, Hatton says. And, he points out, in contrast to conventional ion exchange systems where release of the captured compounds and regeneration of the adsorbents would require the addition of chemicals, "in our case you can just flip a switch" to achieve the same result by switching the polarity of the electrodes. The research team has already racked up a series of honors for the ongoing development of water treatment technology, including grants from the J-WAFS Solutions and Massachusetts Clean Energy Catalyst competitions, and the researchers were the top winners last year's MIT Water Innovation Prize. The researchers have applied for a patent on the new process. "We definitely want to implement this in the real world," Hatton says. In the meantime, they are working on scaling up their prototype devices in the lab and improving the chemical robustness. This technique "is highly significant, as it extends the capabilities of electrochemical systems from basically nonselective toward highly selective removal of key pollutants," says Matthew Suss, an assistant professor of mechanical engineering at Technion Institute of Technology in Israel, who was not involved in this work. "As with many emerging water purification techniques, it must still must be tested under real-world conditions and for long periods to check durability. However, the prototype system achieved over 500 cycles, which is a highly promising result." These researchers "have systematically explored a variety of device configurations and a variety of contaminants," says Kyle Smith, a professor of mechanical science and engineering at the University of Illinois, who also was not involved in this work. "In the process they have identified general design principles by which to achieve selective removal of contaminants. In this regard, I find Hatton and co-workers' study to be very thorough and thoughtful. It provides a framework or paradigm for other researchers to emulate." But, he adds, "A significant challenge that remains is the scale-up of these technologies." Explore further: Adsorbent that can selectively remove water contaminants More information: Xiao Su et al. Asymmetric Faradaic systems for selective electrochemical separations, Energy Environ. Sci. (2017). DOI: 10.1039/C7EE00066A


News Article | May 10, 2017
Site: www.eurekalert.org

CAMBRIDGE, Mass. -- When it comes to removing very dilute concentrations of pollutants from water, existing separation methods tend to be energy- and chemical-intensive. Now, a new method developed at MIT could provide a selective alternative for removing even extremely low levels of unwanted compounds. The new approach is described in the journal Energy and Environmental Science, in a paper by MIT postdoc Xiao Su, Ralph Landau Professor of Chemical Engineering T. Alan Hatton, and five others at MIT and at the Technical University of Darmstadt in Germany. The system uses a novel method, relying on an electrochemical process to selectively remove organic contaminants such as pesticides, chemical waste products, and pharmaceuticals, even when these are present in small yet dangerous concentrations. The approach also addresses key limitations of conventional electrochemical separation methods, such as acidity fluctuations and losses in performance that can happen as a result of competing surface reactions. Current systems for dealing with such dilute contaminants include membrane filtration, which is expensive and has limited effectiveness at low concentrations, and electrodialysis and capacitive deionization, which often require high voltages that tend to produce side reactions, Su says. These processes also are hampered by excess background salts. In the new system, the water flows between chemically treated, or "functionalized," surfaces that serve as positive and negative electrodes. These electrode surfaces are coated with what are known as Faradaic materials, which can undergo reactions to become positively or negatively charged. These active groups can be tuned to bind strongly with a specific type of pollutant molecule, as the team demonstrated using ibuprofen and various pesticides. The researchers found that this process can effectively remove such molecules even at parts-per-million concentrations. Previous studies have usually focused on conductive electrodes, or functionalized plates on just one electrode, but these often reach high voltages that produce contaminating compounds. By using appropriately functionalized electrodes on both the positive and negative sides, in an asymmetric configuration, the researchers almost completely eliminated these side reactions. Also, these asymmetric systems allow for simultaneous selective removal of both positive and negative toxic ions at the same time, as the team demonstrated with the herbicides paraquat and quinchlorac. The same selective process should also be applied to the recovery of high-value compounds in a chemical or pharmaceutical production plant, where they might otherwise be wasted, Su says. "The system could be used for environmental remediation, for toxic organic chemical removal, or in a chemical plant to recover value-added products, as they would all rely on the same principle to pull out the minority ion from a complex multi-ion system." The system is inherently highly selective, but in practice it would likely be designed with multiple stages to deal with a variety of compounds in sequence, depending on the exact application, Su says. "Such systems might ultimately be useful," he suggests, "for water purification systems for remote areas in the developing world, where pollution from pesticides, dyes, and other chemicals are often an issue in the water supply. The highly efficient, electrically operated system could run on power from solar panels in rural areas for example." Unlike membrane-based systems that require high pressures, and other electrochemical systems that operate at high voltages, the new system works at relatively benign low voltages and pressures, Hatton says. And, he points out, in contrast to conventional ion exchange systems where release of the captured compounds and regeneration of the adsorbents would require the addition of chemicals, "in our case you can just flip a switch" to achieve the same result by switching the polarity of the electrodes. The research team has already racked up a series of honors for the ongoing development of water treatment technology, including grants from the J-WAFS Solutions and Massachusetts Clean Energy Catalyst competitions, and the researchers were the top winners last year's MIT Water Innovation Prize. The researchers have applied for a patent on the new process. "We definitely want to implement this in the real world," Hatton says. In the meantime, they are working on scaling up their prototype devices in the lab and improving the chemical robustness. The team also included Kai-Jher Tan, Johannes Elbert, and Robert R. Taylor Professor of Chemistry Timothy Jamison at MIT; and Christian Ruttiger and Markus Gallei at the Technical University of Darmstadt. The work was supported by a seed grant from the Abdul Latif Jameel World Water and Food Security Lab (J-WAFS) at MIT.


Flash Physics is our daily pick of the latest need-to-know developments from the global physics community selected by Physics World's team of editors and reporters NASA's Juno mission has sent back stunning images of Jupiter's poles. The above image shows the gas-giant's south pole. The spacecraft's JunoCam instrument took multiple pictures from an altitude of 52,000 km on three separate orbits, allowing researchers to create full enhanced colour projection. The images of both poles reveal that they are covered in Earth-sized swirling storms up to 1000 km across, but do not look like each other. "We're questioning whether this is a dynamic system, and are we seeing just one stage, and over the next year, we're going to watch it disappear, or is this a stable configuration and these storms are circulating around one another?" explains Juno's principal investigator Scott Bolton. As well as the images, Juno sent back a huge array of results from its first data-collection pass. They are presented in two Science papers and 44 papers in Geophysical Research Letters. "There is so much going on here that we didn't expect, that we have had to take a step back and begin to rethink this as a whole new Jupiter," says Bolton. Tiny water drops have surprisingly ordered surfaces, according to Sylvie Roke from École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and colleagues. The team looked at droplets with a diameter of around 200 nm. Such nanoscale beads of water are everywhere – in the air, rocks, oil fields and even our bodies – and therefore understanding their behaviour may provide insights into atmospheric, geological and biological processes. To study the tiny droplets, the scientists look at how their curved surfaces interact with the surrounding water-repellent environment. "The method involves overlapping ultrashort laser pulses in a mixture of water droplets in liquid oil and detecting photons that are scattered only from the interface," explains Roke. "These photons have the sum frequency of the incoming photons and are thus of a different colour. With this newly generated colour we can know the structure of only the interface." The team discovered that the surfaces of these tiny pockets of water at room temperature are much more ordered than that of normal water. The enhanced tetrahedral structure is instead comparable to super-cooled water – liquid water below the freezing point – which has very strong hydrogen bonds between the water molecules. The results, presented in Nature Communications, suggest the nano-droplets may have reduced reactivity, and further studies will investigate how this affects real-world systems. A new way of working out whether a "fifth force" exists has been developed by an international team led by Andrea Ghez and Aurélien Hees at the University of California, Los Angeles. The group looked at the motions of two stars (S0-2 and S0-38), which orbit the supermassive black hole (SMBH) at the centre of the Milky Way. The stars were monitored for 19 years, which is roughly the time it takes the stars to complete an orbit of the SMBH. The team looked for deviations from the trajectories predicted by Einstein's general theory of relativity, and no discrepancies were seen. This suggests that the strength of a fifth force is less than 1.6% the strength of gravity. Modern physics includes four forces: gravity, and the electromagnetic, strong and weak forces. A hypothetical fifth force appears in some theories that try to unify gravity with quantum mechanics or to explain dark matter and dark energy. While much stronger exclusions of a fifth force have already been obtained by studying forces on masses on Earth and also on objects within the solar system, this is the first study to look at large objects in the huge gravitational field of a SMBH. Writing in Physical Review Letters, Ghez, Hees and colleagues point out that their measurement should be improved next year when one of the stars makes its closest approach to the SMBH, where a deviation from general relatively could be strongest. A new interaction between light and a material has been observed by physicists in Austria and Germany. The team shone a polarized beam of terahertz electromagnetic radiation through a thin film that included a topological insulator in an applied magnetic field. The researchers found that the polarization of the beam is rotated by a specific angle as it travels through the material. At first glance, this rotation is similar to the well-known magneto-optical effect that occurs when light passes through a magnetic material. However, Andrei Pimenov and colleagues at the Technical University of Vienna and the University of Würzburg found that the angle is independent of the thickness of the topological insulator – which is not the case for the magneto-optical effect. Furthermore, they found that the angle is fixed at a specific value that is related to the fine-structure constant. This is a dimensionless quantity that defines the strength of the electromagnetic interaction. According to the team, the polarization is rotated by a fixed value every time it passes through a surface of the topological insulator. The researchers say this is related to the peculiar properties of a topological insulator, which is an electrical conductor at its surfaces but an insulator in the bulk. Writing in Nature Communications, the team says that this "topological magnetoelectric effect" could provide a way of defining three basic physical constants that are related to the fine structure constant: the charge of the electron, the speed of light and the Planck constant.


News Article | May 24, 2017
Site: news.yahoo.com

Those who watched The Space Between Us would surely have a fresh memory of the plane that Gary Oldman’s character flew from the ground into space. The plane probably used plasma jet engines and they are being developed on Earth right now. Still, to make that plane a reality will take quite some time. A team of researchers from the Technical University of Berlin spoke to New Scientist about their plasma jet fuel engine that can propel a plane into the air, to the edge of space, using nothing but electricity and air. Well, “nothing but” is a bit too mildly put, as the electricity that the engines would use will have to come from somewhere, like a battery. The leader of the team told New Scientist’s Sandrine Ceurstemont that “We are the first to produce fast and powerful plasma jets at ground level. These jets of plasma can reach speeds of up to 20 kilometres a second.” Berkant Göksel, from Technical University of Berlin, added that “We want to develop a system that can operate above an altitude of 30 kilometres where standard jet engines cannot go.” This is certainly an ambitious goal, and the first step seems promising. Plasma jet engines use electricity to generate electromagnetic fields, which then compress a gas into plasma—the fuel in the heart of a star. This makes them extremely powerful, but also confined to labs because so far, they have all been designed to work in the vacuum of space or in very low pressures near the edge of the atmosphere. Göksel’s team developed an engine that can work in the air, which was a major accomplishment, but the practical application of the invention is still years away. The engine that the team developed is actually an assembly of mini thrusters of 8 cm in length. An average airliner would need 10,000 of them to fly, and installing so many thrusters would be a challenge. Yet at most, only 1,000 of the mini thrusters would be required for smaller planes, which is why the team is targeting these for further tests. The more serious problem is the supply of electricity. Whatever the size of the plane that will go to the edge of space thanks to the plasma jet thrusters, it will need to carry with it a battery, or as one Israeli researcher said, “a small electrical power plant.” Today’s batteries are not up to this task. For example, a Tesla Model S battery weighs about half a ton and has a capacity of 85 kWh. The battery provides the energy for the 380-horse power electric engine. The engine of a Boeing 747-400, on the other hand, has a power that equals more than 95,000 horse power. In other words, for the plasma jet technology to become commercially viable, another invention is needed: a lightweight, super energy-dense battery that can be mounted on the aircraft. For Göksel, there are alternatives, such as solar panels—again a challenging option—or wireless transfer of energy to the plane’s engine. The researcher, however, is pinning most of his hopes on advancements in compact fusion reactors. This could solve the battery problem by going around it. However, even large-scale fusion reactors are not yet a viable alternative to traditional fission reactors, let alone compact ones. So while the hype is well deserved, a replication of Gary Oldman’s plane journey into space is still years away.


News Article | May 3, 2017
Site: news.yahoo.com

(Reuters) - Europe’s top tech hubs tend to radiate from massive capital cities like London, Berlin and Paris. But the heart of European innovation isn’t a major metropolis –it’s a small city in the Dutch-speaking region of Flanders. That’s the conclusion of Reuters’ second annual ranking of Europe’s Most Innovative Universities, a list that identifies and ranks the educational institutions doing the most to advance science, invent new technologies, and help drive the global economy. The most innovative university in Europe, for the second year running, is Belgium’s KU Leuven. This nearly 600-year-old institution was founded by Pope Martin V, but today it’s better known for technology than theology: KU Leuven maintains one of the largest independent research and development organizations on the planet. In fiscal 2015, the university’s research spending exceeded €454 million, and its patent portfolio currently includes 586 active families, each one representing an invention protected in multiple countries. How does a relatively small Catholic university out-innovate bigger, better-known institutions across Europe? KU Leuven earned its first-place rank, in part, by producing a high volume of influential inventions. Its researchers submit more patents than most other universities on the continent, and outside researchers frequently cite KU Leuven inventions in their own patent applications. Those are key criteria in Reuters ranking of Europe’s Most Innovative Universities, which was compiled in partnership with Clarivate Analytics, and is based on proprietary data and analysis of indicators including patent filings and research paper citations. The second most innovative university in Europe is Imperial College London, an institution whose researchers have been responsible for the discovery of penicillin, the development of holography and the invention of fiber optics. The third-place University of Cambridge has been associated with 91 Nobel Laureates during its 800-year history. And the fourth-place Technical University of Munich has spun off more than 800 companies since 1990, including a variety of high-tech startups in industries including renewable energy, semiconductors and nanotechnology. Overall, the same countries that dominate European business and politics dominate the ranking of Europe's Most Innovative Universities. German universities account for 23 of the 100 institutions on the list, more than any other country, and the United Kingdom comes in second, tied with France, each with 17 institutions. But those three countries are also among the most populous and richest countries on the continent. Control for those factors, and it turns out that countries with much smaller populations and modest economies often outperform big ones. The Republic of Ireland has only three schools on the entire list, but with a population of less than 5 million people, it can boast more top 100 innovative universities per capita than any other country in Europe. On the same per capita basis, the second most innovative country on the list is Denmark, followed by Belgium, Switzerland and the Netherlands. Germany, the United Kingdom and France rank in the middle of the pack, an indication that they may be underperforming compared with their smaller neighbors: On a per capita basis, none of those countries has half as many top 100 universities than Ireland. And the same trends hold true if you look at national economies. According to the International Monetary Fund, in 2016 Germany’s gross domestic product exceeded $3.49 trillion –11 times larger than Ireland at $307 billion, yet Germany has only 7 times as many top 100 innovative universities. Some countries underperform even more drastically. Russia is Europe’s most populous country and has the region’s fifth largest economy, yet none of its universities count among the top 100. Other notable absences include any universities from Ukraine or Romania–a fact that reveals another divide between Western and Eastern Europe. To compile the ranking of Europe’s most innovative universities, Clarivate Analytics (formerly the Intellectual Property & Science business of Thomson Reuters) began by identifying more than 600 global organizations that published the most articles in academic journals, including educational institutions, nonprofit charities, and government-funded institutions. That list was reduced to institutions that filed at least 50 patents with the World Intellectual Property Organization in the period between 2010 and 2015. Then they evaluated each candidate on 10 different metrics, focusing on academic papers (which indicate basic research) and patent filings (which point to an institution's ability to apply research and commercialize its discoveries). Finally, they trimmed the list so that it only included European universities, and then ranked them based on their performance. This is the second consecutive year that Clarivate and Reuters have collaborated to rank Europe’s Most Innovative Universities, and three universities that ranked in the top 100 in 2016 fell off the list entirely: the Netherland’s Eindhoven University of Technology, Germany’s University of Kiel, and the UK’s Queens University Belfast. All three universities filed fewer than 50 patents during the period examined for the ranking, and thus were eliminated from consideration. They’ve been replaced by three new entrants to the top 100: the University of Glasgow (#54), the University of Nice Sophia Antipolis (#94), and the Autonomous University of Madrid (#100). The returning universities that made the biggest moves on the list were the Netherland’s Leiden University (up 21 spots to #17) and Germany’s Technical University of Berlin (up 21 spots to #41). Belgium’s Université Libre of Brussels (down 17 to #38) and the UK’s University of Leeds (down 17 to #73) made the biggest moves in the opposite direction. Generally, though, the list remained largely stable: Nine of the top ten schools of 2016 remained in the top 10 for 2017, and 17 of the top 20. This stability is understandable because something as large as university paper output and patent performance is unlikely to change quickly. Of course, the relative ranking of any university does not provide a complete picture of whether its researchers are doing important, innovative work. Since the ranking measures innovation on an institutional level, it may overlook particularly innovative departments or programs: a university might rank low for overall innovation but still operate one of the world's most innovative computer science laboratories, for instance. And it's important to remember that whether a university ranks at the top or the bottom of the list, it's still within the top 100 on the continent: All of these universities produce original research, create useful technology and stimulate the global economy.


News Article | April 17, 2017
Site: www.nature.com

In the search for new physics, experiments based on high-energy collisions inside massive atom smashers are coming up empty-handed. So physicists are putting their faith in more-precise methods: less crash-and-grab and more watching-ways-of-wobbling. Next month, researchers in the United States will turn on one such experiment. It will make a super-accurate measurement of the way that muons, heavy cousins of electrons, behave in a magnetic field. And it could provide evidence of the existence of entirely new particles. The particles hunted by the new experiment, at the Fermi National Laboratory in Batavia, Illinois, comprise part of the virtual soup that surrounds and interacts with all forms of matter. Quantum theory says that short-lived virtual particles constantly ‘blip’ in and out of existence. Physicists already account for the effects of known virtual particles, such as photons and quarks. But the virtual soup might have mysterious, and as yet unidentified, ingredients. And muons could be particularly sensitive to them. The new Muon g−2 experiment will measure this sensitivity with unparalleled precision. And in doing so, it will reanalyse a muon anomaly that has puzzled physicists for more than a decade. If the experiment confirms that the anomaly is real, then the most likely explanation is that it is caused by virtual particles that do not appear in the existing physics playbook — the standard model. “It would be the first direct evidence of not only physics beyond the standard model, but of entirely new particles,” says Dominik Stöckinger, a theorist at the Technical University of Dresden, Germany, and a member of the Muon g−2 collaboration. Physicists are crying out for a successor to the standard model — a theory that has been fantastically successful yet is known to be incomplete because it fails to account for many phenomena, such as the existence of dark matter. Experiments at the Large Hadron Collider (LHC) at CERN, Europe’s particle-physics lab near Geneva, Switzerland, have not revealed a specific chink, despite performing above expectation and carrying out hundreds of searches for physics beyond the standard model. The muon anomaly is one of only a handful of leads that physicists have. Measurements of the muon’s magnetic moment — a fundamental property that relates to the particle’s inherent magnetism — could hold the key, because it is tweaked by interactions with virtual particles. When last measured 15 years ago at the Brookhaven National Laboratory in New York, the muon’s magnetic moment was larger than theory predicts. Physicists think that interaction with unknown particles, perhaps those envisaged by a theory called supersymmetry, might have caused this anomaly. Other possible explanations are a statistical fluke, or a flaw in the theorists᾽ standard-model calculation, which combines the complex effects of known particles. But that is becoming less likely, says Stöckinger, who says that new calculation methods and experimental cross-checks make the theoretical side much more robust than it was 15 years ago. “With this tantalizing result from Brookhaven, you really have to do a better experiment,” says Lee Roberts, a physicist at Boston University in Massachusetts, who is joint leader of the Muon g−2 experiment. The Fermilab set-up will use 20 times the number of muons used in the Brookhaven experiment to shrink uncertainty by a factor of 4. “If we agree, but with much smaller error, that will show definitively that there’s some particle that hasn’t been observed anywhere else,” he says. To probe the muons, Fermilab physicists will inject the particles into a magnetic field contained in a ring some 14 metres across. Each particle has a magnetic property called spin, which is analogous to Earth spinning on its axis. As the muons travel around the ring at close to the speed of light, their axes of rotation wobble in the field, like off-kilter spinning tops. Combining this precession rate with a measurement of the magnetic field gives the particles’ magnetic moment. Since the Brookhaven result, some popular explanations for the anomaly — including effects of hypothetical dark photons — seem to have been ruled out by other experiments, says Stöckinger. “But if you look at the whole range of scenarios for physics beyond the standard model, there are many possibilities.” Although a positive result would give little indication of exactly what the new particles are, it would provide clues to how other experiments might pin them down. If the relatively large Brookhaven discrepancy is maintained, it can only come from relatively light particles, which should be within reach of the LHC, says Stöckinger, even if they interact so rarely that it takes years for them to emerge. Indeed, the desire to build on previous findings is so strong that to avoid possible bias, Fermilab experimenters will process their incoming results ‘blind’ and apply a different offset to each of two measurements that combine to give the magnetic moment. Only once the offsets are revealed will anyone know whether they have proof of new particles hiding in the quantum soup. “Until then nobody knows what the answer is,” says Roberts. “It will be an exciting moment.”

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