Detoxifying Nerve Agents Using Functionalized Polymer Nanofiber Membranes

first_imgUsing UV spectrophotometry, Sundarrajan and his peers analyzed the hydrolysis of paraxon and found that the most effective hydrolysis came from oxy-B-CD nanofiber membrane. “The ether group from oxy-B-CD acted as a linker with the benzene ring and optimized the interactions between the catatlyst and the paraxon,” he explained. The scientists made another startling observation: “As the yield of the oxy-B-CD increased, the extent to which the nerve agent stimulant hydrolyzed also increased,” Sundarrajan said. By manipulating the ether group that is between B-CD and IBA, the scientists could cause this increase in oxy-B-CD.The oxy-B-CD broke down paraxon into diethyl phosphoric acid and p-nitorphenol, which changed from the acid base to the base form (p-nitorphenolate). “A highly-stable complex between p-nitrophenolate anion and B-CD occurs, possibly from polarizability and resonance delocalization,” Sundarrajan added. Sundarrajan and his team measured the amount of p-nitrophenol with UV spectrophotometry, finding a maximum at 410 +- 10 nm. In other words, the nanofiber membranes functionalized with oxy-B-CD were effective in decontaminating paraxon.Furthermore, the team of scientists compared the hydrolysis of paraxon with activated carbon to the hydrolysis with oxy-B-CD, as well as the other types of functionalized PVC polymer nanofiber membranes. The team found that the oxy-B-CD was 11.5 times faster than the activated carbon and that the oxy-B-CD was also faster than B-CD, IBA, and the B-CD and IBA combination nanofibers.Manufacturers can add oxy-B-CD nanofiber membranes to woven clothing, leading to decontamination of organophosphorous nerve agents, as well as lighter and more breathable clothing. “Next we are trying to develop non-specific catalysts that will decompose both nerve and blister agents,” Sundarrajan says. By Syeda Z. Hamdani, Copyright 2006 PhysOrg.com Citation: Detoxifying Nerve Agents Using Functionalized Polymer Nanofiber Membranes (2006, July 10) retrieved 18 August 2019 from https://phys.org/news/2006-07-detoxifying-nerve-agents-functionalized-polymer.html A group of scientists from the National University of Singapore published a study in the May 30th issue of Nanotechnology, which developed polymer nanofiber membranes with a synthesized catalyst to detoxify nerve agents. Research fellow Subramanian Sundarrajan, with the University’s Bioengineering Division, and his colleagues wanted a method to detoxify organophosphorus nerve agents, such as Soman, Sarin, and Tabun. “Nerve agents disrupt the human nervous system by inhibiting the actylcholine esterase enzyme,” Sundarrajan said.Currently, protective clothing for OP nerve agents use functionalized activated carbon. Disadvantages to carbon include its heaviness, its ability to hold moisture, and having to dispose of contaminated clothing because of absorption.An important aspect of the study involved the choice of catalyst. “Literature showed that B-CD (B-cyclodextrin) and IBA (o-iodosobenzoic acid) have a history of hydrolyzing nerve agents. We hypothesized that if we synthesized a CD derivative with IBA functionality, it would have better catalytic properties,” Sundarrajan explained.As a result, Sundarrajan and his group chose 3-carboxy-4-iodosobenzyl oxy-B-CD, which was a CD derivative, as one of the catalysts in the experiment. The team also used other variations of B-CD and IBA. The material for the nanofiber membranes was equally vital; in the past, the scientists had experimented with nanofibers spun from cellulose acetate, but found this material to be too fragile.Instead, the scientists used PVC polymer for the nanofibers because of its advantages: PVC has a small fiber diameter, is extremely porous, and has a high surface area. “A high surface area helps in obtaining better reactivity with the catalyst,” Sundarrajan said.For the control portion of the experiment, Sundarrajan and his colleagues electrospun one set of PVC polymers into nanofiber membranes without a catalyst. They also electrospun PVC with B-CD, PVC with IBA, PVC with B-CD and IBA and PVC with oxy-B-CD. All functionalized nanofiber membranes were hydrophilic, with varying static water contact angles: 10 degress for the plain PVC and PVC with IBA, 12 degress for PVC with B-CD, 7 degrees for PVC with B-CD and IBA, and 9 degrees for PVC with the oxy-B-CD.To test the effectiveness of the functionalized nanofibers, the scientists chose paraxon, a nerve agent stimulant that can be analyzed with UV spectrophotometry. They dipped the nanofiber membranes in three different concentrations of paraxon, 10mM, 25mM, and 50mM, at 25 degrees C, as well as one additional beaker which had unhydrolyzed paraxon for comparison. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

First Analysis of the Water Requirements of a Hydrogen Economy

first_img Explore further One of the touted benefits of the futuristic US hydrogen economy is that the hydrogen supply—in the form of water—is virtually limitless. This assumption is taken for granted so much that no major study has fully considered just how much water a sustainable hydrogen economy would need. Based on the atomic properties of water, 1 kg of hydrogen gas requires about 2.4 gallons of water as feedstock. In one year, 60 billion kilograms of hydrogen would require 143 billion gallons of fresh, distilled water. This number is similar to the amount of water required for refining an equivalent amount of petroleum (about 1-2.5 gallons of water per gallon of gasoline).The biggest increase in water usage would come from indirect water requirements, specifically as a cooling fluid for the electricity needed to supply the energy that electrolysis requires. Since electrolysis is likely to use existing infrastructure, it would pull from the grid and therefore depend on thermoelectric processes. At 100% efficiency, electrolysis would require close to 40 kWh per kilogram of hydrogen—a number derived from the higher heating value of hydrogen, a physical property. However, today’s systems have an efficiency of about 60-70%, with the DOE’s future target at 75%. Depending on the fraction of hydrogen produced by electrolysis (Webber presents estimates for values from 35 to 85%), the amount of electricity required based on electrolysis efficiency of 75% would be between 1134 and 2754 billion kWh—and up to 3351 billion kWh for a lower electrolysis efficiency of 60%. For comparison, the current annual electricity generation in the US in 2005 was 4063 billion kWh. In 2000, thermoelectric power generation required an average of 20.6 gallons of water per kWh, leading Webber to estimate that hydrogen production through electrolysis, at 75% efficiency, would require about 1100 gallons of cooling water per kilogram of hydrogen. That’s 66 trillion gallons per year just for cooling.By 2050, the NRC report predicts that hydrogen demand could exceed 100 billion kg—nearly twice the 60 billion kg that Webber’s estimates are based on. By then, researchers may find better ways of producing hydrogen, with assistance from the DOE’s large-scale investments, which will exceed $900 million in 2008. “That most of the water use is for cooling leaves hope that we can change the way power plants operate, which would significantly ease up the potential burden on water resources, or that we can find other means of power production at a large scale to satisfy the demands of electrolysis,” said Webber.If electrolysis becomes a widespread method of hydrogen production, Webber suggests that researchers may want to look for an electricity-generating method other than thermoelectric processes to power electrolysis. With this perspective, he suggests hydrogen pathways such as wind or solar sources, as well as water-free cooling methods such as air cooling.“Each of the energy choices we can make, in terms of fuels and technologies, has its own tradeoffs associated with it,” Webber said. “Hydrogen, just like ethanol, wind, solar, or other alternative choices, has many merits, but also has some important impacts to keep in mind, as this paper tries to suggest. I would encourage the continuation of research into hydrogen production as part of a comprehensive basket of approaches that are considered for managing the transition into the green energy era. But, because of some of the unexpected impacts—for example on water resources—it seems premature to determine that hydrogen is the answer we should pursue at the exclusion of other options.”More information can be found at the Webber Energy Group, an organization which seeks to bridge the divide between policymakers and engineers & scientists for issues related to energy and the environment.Citation: Webber, Michael E. “The water intensity of the transitional hydrogen economy.” Environmental Research Letters, 2 (2007) 034007 (7pp).Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Michael Webber, Associate Director at the Center for International Energy and Environmental Policy at the University of Texas at Austin, has recently filled that gap by providing the first analysis of the total water requirements with recent data for a “transitional” hydrogen economy. While the hydrogen economy is expected to be in full swing around 2050 (according to a 2004 report by the National Research Council [NRC]), a transitional hydrogen economy would occur in about 30 years, in 2037. At that time, the NRC predicts an annual production of 60 billion kg of hydrogen. Webber’s analysis estimates that this amount of hydrogen would use about 19-69 trillion gallons of water annually as a feedstock for electrolytic production and as a coolant for thermoelectric power. That’s 52-189 billion gallons per day, a 27-97% increase from the 195 billion gallons per day (72 trillion gallons annually) used today by the thermoelectric power sector to generate about 90% of the electricity in the US. During the past several decades, water withdrawal has remained stable, suggesting that this increase in water intensity could have unprecedented consequences on the natural resource and public policy.“The greatest significance of this work is that, by shifting our fuels production onto the grid, we can have a very dramatic impact on water resources unless policy changes are implemented that require system-wide shifts to power plant cooling methods that are less water-intensive or to power sources that don’t require cooling,” Webber told PhysOrg.com. “This analysis is not meant to say that hydrogen should not be pursued, just that if hydrogen production is pursued through thermoelectrically-powered electrolysis, the impacts on water are potentially quite severe.”Webber’s estimate accounts for both the direct and indirect uses of water in a hydrogen economy. The direct use is water as a feedstock for hydrogen, where water undergoes a splitting process that separates hydrogen from oxygen. Production can be accomplished in several ways, such as steam methane reforming, nuclear thermochemical splitting, gasification of coal or biomass, and others. But one of the dominant production methods in the transitional stage, as predicted in a 2004 planning report from the Department of Energy (DOE), will likely be electrolysis. This graph shows the annual water consumption as a feedstock and coolant for generating 60 billion kg of hydrogen, which is influenced by both the fraction of hydrogen that is produced by thermoelectrically powered electrolysis and electrolyzer efficiencies. Image credit: Michael E. Webber.center_img Energy storage project in Utah described as world’s largest of its kind Citation: First Analysis of the Water Requirements of a Hydrogen Economy (2007, October 18) retrieved 18 August 2019 from https://phys.org/news/2007-10-analysis-requirements-hydrogen-economy.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Humpback whale migration as straight as an arrow

first_img More information: Straight as an arrow: humpback whales swim constant course tracks during long-distance migration, Biol. Lett. Published online before print April 20, 2011, doi: 10.1098/rsbl.2011.0279AbstractHumpback whale seasonal migrations, spanning greater than 6500 km of open ocean, demonstrate remarkable navigational precision despite following spatially and temporally distinct migration routes. Satellite-monitored radio tag-derived humpback whale migration tracks in both the South Atlantic and South Pacific include constant course segments of greater than 200 km, each spanning several days of continuous movement. The whales studied here maintain these directed movements, often with better than 1° precision, despite the effects of variable sea-surface currents. Such remarkable directional precision is difficult to explain by established models of directional orientation, suggesting that alternative compass mechanisms should be explored. Jump in whale deaths blamed on krill, ship traffic Published in Biology Letters, lead author Dr. Travis Horton explained how they fitted these 16 whales with satellite tracking and followed their migratory path from the east coast of Brazil, the Cook Islands and New Caledonia. The tracking provided precise position data and enabled the largest detailed long-term migratory data to date.Traveling over 6000 kilometers into Antarctic waters, they discovered these whales traveled from 100 to 2000 kilometers at a time in a straight line, never deviating off course by more than a single degree.While it is believed that most migratory animals navigate with the use of compass clues from the sun or the Earth’s magnetic field, these shift by several degrees. Given the fact that the whales maintain a straight course, regardless of weather or currents, researchers believe that they cannot be using one of these alone. As the researchers have said, the Earth’s magnetism varies and in water, solar navigation cannot be relied on. They believe it is possible that the whales could be using both together.Horton also believes that the whales could be using the moon and stars to aid in navigation. Another researcher, John Calambokidis from the Cascadia Research Collective believes there could be another tool aiding the whales. He believes that by using long distance sounds, or songs, the whales may be using these as navigational cues.While they are only beginning to understand the migratory process of the humpback whale, understanding the mechanism they are using to remain on this straight course will take time. Horton and his team intend to continue with their research. Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Humpback whale migration as straight as an arrow (2011, April 22) retrieved 18 August 2019 from https://phys.org/news/2011-04-humpback-whale-migration-straight-arrow.html © 2010 PhysOrg.com Humpback whale. Credit: NOAA. (PhysOrg.com) — Over the last eight years, researchers from the University of Canterbury have been tracking 16 radio-tagged humpback whales through their migratory paths and learned that these whales follow a straight line for thousands of kilometers.last_img read more

Intel predicts the death of mobile computing as we know it

first_img More information: This prediction is based on the statements of Rama Skukla, the vice president of Intel’s architecture group. During his keynote address at SEMICON West, a conference that takes place regularly in San Francisco, he stated that “tablets are disappearing”, and that the current types of devices we would be using in a decade from now “could not be described”.His remarks went off to say that, “The lines between a netbook, laptop and tablet are disappearing faster than designers today realize. It’s going to be very difficult to see where one device goes and the next one takes off.”Of course, he also has some other ideas about the future of technology. It was strongly implies by his remarks that he thinks that the personal computer will become outdated and that the future of PCs will be more like personal syncing grounds, connecting the users to an individual cloud of information that can be shared at will. While that concept is intriguing it could easily make the more security minded consumers out there nervous, since all data that is on the cloud is data that can be breached by determined hackers. In order to be read for these changes Intel is expecting to make major advances in processors over the next five years, including raising graphics performance by a factor of 12. via V3, Inquirer (PhysOrg.com) — The folks over at Intel have come up with an interesting prediction, one that may make all of you feel a little bit foolish for buying a laptop, and a netbook or a tablet. They are predicting that as time goes on the form factors in the mobile device market will break down and the distinctions between the devices will be largely a moot point. Companies will instead make multi-purpose smart computing devices. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: Intel predicts the death of mobile computing as we know it (2011, July 13) retrieved 18 August 2019 from https://phys.org/news/2011-07-intel-death-mobile.html © 2010 PhysOrg.com Explore further Computex: Intel Outlines Atom Processor Plans, Productslast_img read more

Geoscientist claims to have found mystery volcano that caused mighty 13th century

first_img Iceland’s Hekla volcano shows signs of activity This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Scientists can pinpoint volcanic activity by looking at ice sample taken from the polar regions and tree rings that reflect a cold period of activity. The blast that occurred in the thirteenth century has been the object of much attention because of the enormous amount of sulfur found in such ice samples. So much so that some suggest that it was the biggest blast in seven thousand years. They give it a seven out of eight on the volcanic explosiveness scale. Up until now there has been a list of leading candidates for the volcano most likely to have caused such a massive outburst, but no real evidence to point to any of them as the true culprit.Lavigne, speaking at the American Geophysical Union conference this year, showed pictures of parts of the volcano he says is the one responsible for the blast and instead of giving its actual name or even general location, showed the evidence he’d collected that he says proves it’s the one that blew back in 1257. Most of those in attendance at the meeting agreed that the pictures he showed depicted a volcano in Indonesia, which would narrow it down some, but not all that much because Indonesia has 130 active volcanoes. Lavigne’s proof came in the form of the results of analyses of rocks that had been taken from the mystery volcano, which apparently show a nearly exact chemical match with the polar ice samples.Unfortunately, not much more will be known about the identity of the volcano until Lavigne’s paper is published and even then, more research by other’s will have to be done before the research community reaches a consensus on Lavigne’s claims; either accepting them as likely the truth about what happened or simply adding his ideas to the list of speculative theories. Explore further The eruption of Mount St. Helens in 1980. Credit: Austin Post, USGS Citation: Geoscientist claims to have found mystery volcano that caused mighty 13th century blast (2012, June 18) retrieved 18 August 2019 from https://phys.org/news/2012-06-geoscientist-mystery-volcano-mighty-13th.html © 2012 Phys.Org More information: Franck Lavigne: The 1258 Mystery Eruption: Environmental Effects, Time of Occurrence and Volcanic Source, AGU Chapman Conference on Volcanism and the Atmosphere, Selfoss, Iceland, 10–15 June 2012.via Sciencenews.org (Phys.org) — For years, geoscientists have known that a volcano erupted sometime in the mid thirteenth century, with nearly unprecedented force. Skies were darkened and the entire planet experienced a temporary cooling. What’s not been known though, is which volcano it was and the exact year that it blew. Scientists have informally agreed that the event likely occurred in the year 1258. Now however geoscientist Franck Lavigne of Panthéon-Sorbonne University, is claiming that he has proof that the volcano actually erupted a year earlier than that, and what’s more, he says, he knows which volcano it was, but won’t say until his paper has been published in an as yet still unnamed journal.last_img read more

Study finds possible link between Arctic change and extreme midlatitude weather

first_img Explore further Arctic warming linked to fewer European and US cold weather extremes, study shows For the past several years planetary researchers have begun to wonder if Arctic warming is causing changes to weather in the northern mid-latitudes. They note, as just one example, the exceedingly harsh 2013/14 winter—very low temperatures in parts of North America and well above average rainfall in parts of Europe.Scientists have grown concerned as measurements have indicated that the Arctic is warming faster than expected—twice as fast as the rest of the planet (Arctic amplification), which means snow and ice is melting faster than expected as well. During the same time period, the mid-latitudes have experienced some unusual weather—stronger storms, colder winters and hotter summers. Several groups have looked to see if a discernible link between the two trends could be found. And while no single team has been able to find concrete evidence, many have found what appears to an indirect link. In this new effort, the researchers suggest that such studies, when looked at as a single entity, provide a strong case for such a link, and they even suggest how: changes to the jet stream, to storm tracks and to planetary waves and their associated energy propagation.Taken together, the researchers report, the data indicates that a weaker temperature gradient between the Arctic region and the northern latitudes, is leading to changes in the atmosphere in the northern hemisphere and because of that, unpredictable changes to weather patterns.The researchers are careful to note that despite the mounting evidence of an Arctic-northern latitude weather link, the degree to which it is likely occurring remains highly uncertain. They suggest more research be undertaken and more models developed to help better understand what a fast warming Arctic may mean for the northern hemisphere in general as the future unfolds. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. (Phys.org) —A team of researchers with members from Europe and the U.S. has found a possible link between Arctic amplification and severe weather in the northern mid-latitude parts of the planet. In their paper published in the journal Nature Geoscience, the researchers describe how they conducted a review of the findings of other researchers looking for a connection between Arctic warming and extreme weather events and what they found as a result. More information: Recent Arctic amplification and extreme mid-latitude weather, Nature Geoscience (2014) DOI: 10.1038/ngeo2234AbstractThe Arctic region has warmed more than twice as fast as the global average—a phenomenon known as Arctic amplification. The rapid Arctic warming has contributed to dramatic melting of Arctic sea ice and spring snow cover, at a pace greater than that simulated by climate models. These profound changes to the Arctic system have coincided with a period of ostensibly more frequent extreme weather events across the Northern Hemisphere mid-latitudes, including severe winters. The possibility of a link between Arctic change and mid-latitude weather has spurred research activities that reveal three potential dynamical pathways linking Arctic amplification to mid-latitude weather: changes in storm tracks, the jet stream, and planetary waves and their associated energy propagation. Through changes in these key atmospheric features, it is possible, in principle, for sea ice and snow cover to jointly influence mid-latitude weather. However, because of incomplete knowledge of how high-latitude climate change influences these phenomena, combined with sparse and short data records, and imperfect models, large uncertainties regarding the magnitude of such an influence remain. We conclude that improved process understanding, sustained and additional Arctic observations, and better coordinated modelling studies will be needed to advance our understanding of the influences on mid-latitude weather and extreme events.center_img Citation: Study finds possible link between Arctic change and extreme mid-latitude weather (2014, August 18) retrieved 18 August 2019 from https://phys.org/news/2014-08-link-arctic-extreme-mid-latitude-weather.html © 2014 Phys.org Journal information: Nature Geoscience Mosaic of images of the Arctic by MODIS. Credit: NASAlast_img read more

Designer does it

Designer Abhi Singh let his hair down with his friends and colleagues from the fash frat by letting his hair down at a restaurant in the Garden of Five Senses in Mehrauli. It was a relaxed evening.  We spotted designers Rahul Singh, Gautam Gupta, Jasmin Waldmann, make-up artist Aamer Zakir among others. We got you snapshots. Take a look.

The magic carpet ride

first_imgThe expo concluded on 21 October after four days of heavy business and much excitement.308 Exhibitors from different parts of the country participated in this export oriented fair where 300 buyers from 57 countries registered their attendance. The fair was also attended by more than 250 buying representatives.Though it is difficult to quantify the exact business generated in the fair but in accordance with the feedback given by the participants it is estimated that fair has generated business of over Rs. 500 to Rs. 550 Crores. The expo proves to be benificial especially for small traders with less resources to display their work. Also Read – ‘Playing Jojo was emotionally exhausting’Indian Handmade Carpet Industry is an age old exportoriented and highly labour intensive and has enormous potential for growth.Siddh Nath Singh, Chairman, CEPC expressed that this event will be beneficial to the medium and small exporters who can’t afford to display their products in overseas exhibitions on the one hand and on the other hand show the capability of India in producing and supplying quality products in time.Umesh Kumar Gupta, Sr. Member of COA, CEPC mentioned that in the current recessionary trend the presence of 300 Overseas Buyers from all over the world in India Carpet Expo establishes the status of India Carpet Expo and demand of Indian products in the international market.Chairman, CEPC, Umesh Kumar Gupta, Senior Member of COA along with other members of the COA, CEPC given their heartfeltcongratulations to Shiv Kumar Gupta, Executive Director-cum-Secretary, CEPC and his team for their strenuous work to make the fair a grand success.last_img read more

ATMs running dry reminds me of demonetisation days Mamata

first_imgKolkata: Amid reports of ATMs running dry in several states, West Bengal Chief Minister Mamata Banerjee on Tuesday said it reminds her of the demonetisation days. She also asked whether a “financial emergency” was going on in the country.”Seeing reports of ATMs running out of cash in several states. Big notes missing. Reminder of #DeMonetisation days. Is there a Financial Emergency going on in the country? #CashCrunch #CashlessATMs,” Banerjee tweeted. Also Read – Heavy rain hits traffic, flightsCurrency shortage was reported in Andhra Pradesh, Telangana and Madhya Pradesh in the past few weeks. There were also complaints of shortage in parts of Maharashtra, Gujarat and Bihar on Monday.However, Union Finance Minister Arun Jaitley on Tuesday said the government has reviewed the situation and “there is more than adequate currency in circulation”.According to the Reserve Bank of India data, currency in circulation as on April 6 was Rs 18.17 lakh crore.last_img read more

Xi Sirisena talk trilateral coop with India

first_imgMaking his first visit to China to re-balance pro-Beijing policies pursued by the previous Mahinda Rajapaksa regime, new Sri Lankan President Maithripala Sirisena held talks for over an hour with his Chinese counterpart Xi Jinping here Thursday.  Xi and Sirisena discussed trilateral cooperation between India, China and Sri Lanka mooted by Beijing recently in an apparent bid to address New Delhi’s reservations over MSR and its implications for India’s security, especially after two Chinese submarines docked in Colombo harbour last year. Also Read – Pro-Govt supporters rally as Hong Kong’s divisions deepen”The two leaders also agreed to strengthen trilateral cooperation between China, Sri Lanka and India,” Chinese Assistant Foreign Minister Liu Jianchao told the media after the talks.”The three are all important countries in the region. It will be really beneficial for the three counties to have cooperation in the areas like economic and social development. It is part of the China and South Asia cooperation,” he said. China vows to deepen ties with PakChina on Thursday pledged to deepen anti-terrorism, maritime security and military technology cooperation with Pakistan to further strengthen their all weather strategic ties.The “pledge” was made by Vice Chairman of China’s Central Military Commission General Fan Changlong during his meeting with the Pakistan Navy Chief Muhammad Zakaullah, state-run Xinhua.last_img read more