Monthly Archives: August 2019

GE and Hitachi want to use nuclear waste as a fuel

first_img © 2010 PhysOrg.com Sustainable nuclear energy moves a step closer Citation: GE and Hitachi want to use nuclear waste as a fuel (2010, February 18) retrieved 18 August 2019 from https://phys.org/news/2010-02-ge-hitachi-nuclear-fuel.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. Conventional nuclear power plants in the US only harness around five percent of the energy of nuclear fuels. The reprocessing technique would separate nuclear waste into different types of fuels, some of which can be used in conventional nuclear power plants, and some of which can only be used in advanced fast neutron reactors. Reprocessing of nuclear waste to extract more useable fuel has been criticized in the US because it produces pure plutonium, which could be stolen and used to make nuclear weapons. To get around this difficulty, GE Hitachi’s proposed method produces a fuel that is much harder to steal.The GE Hitachi process separates wastes from conventional nuclear power plants into three streams, by applying voltage to a molten salt. The first waste material consists of the products of fission, which cannot be further used as fuel and will need to be stored, but the storage time required is reduced from tens of thousands of years to a few hundred years (although a small fraction of the material will still need to be stored for over 10,000 years). The second material is uranium that does not have enough fissile material to be used in the light water uranium reactors in the US, which need enriched uranium, but it can be used by deuterium (heavy water) uranium reactors, which are used in Canada. The final group of waste products is a mixture of transuranic elements including plutonium and neptunium. The plutonium is not separated from the other elements, and the mixture releases 1,000 times more heat and 10,000 times more neutrons than pure plutonium. This makes it much harder to steal, and therefore less of a security risk, and it is also much easier to detect. The mixture of transuranic elements can be used in nuclear reactors that use molten sodium as the coolant rather than water, and this type is used in Japan and a few other countries. GE Hitachi has designed a reactor known as the PRISM reactor that would be able to use the mixed fuel, but sodium cooled reactors have not been approved for use in the US.A GE Hitachi spokesman said previous US administrations had little interest in re-using spent nuclear fuel, but the Obama administration is increasing support for nuclear power and looking at possibilities such as reprocessing. If adopted, the proposal would significantly decrease the amount of dangerous nuclear waste that needs to be stored. Explore further (PhysOrg.com) — One of the world’s biggest providers of nuclear reactors, GE Hitachi Nuclear Energy (a joint venture of General Electric and Hitachi), wants to reprocess nuclear waste for use as a fuel in advanced nuclear power plants, instead of burying it in waste repositories such as that proposed at Nevada’s Yucca Mountain.last_img read more

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Soraa LED light may dim 50watt halogen rivals

first_img 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. The MR16 is used in the commercial sector by restaurants, retail sites, and museums. These are lighting’s especially demanding, finicky customers, as they need lighting to enhance their décor, inspire mood, highlight merchandise, and complement works of art.“It’s more difficult to do this MR16 light, so we choose to do this first to showcase our technology,” Eric Kim, CEO of Soraa, told Forbes. Beyond challenge, though, the commercial sector is a good business move because it will help the company to grow. Commercial customers have to think about initial costs and longer term payback in lighting, at prices that may turn off noncommercial customers. Retail owners, for example, depend on exceptionally good lighting systems to lure people into their shops.The company was started by lighting experts focused on work with LEDs and lasers. Shuji Nakamura, one of the founders, was key to the technology that gives Soraa its core competency. Nakamura is regarded as a pioneer in modern LED lighting; he is known for his work with gallium-nitride. The material gallium nitride (GaN) has been used in bright light-emitting diodes since the 1990s.“We believe that with GaN on GaN, we have truly entered the next chapter in LED technology: LED 2.0.” said Nakamura in a Wednesday news release.Soraa is betting its future on its different development approach to LED lighting to put it ahead of competition. The difference is in the LED crystal structure. Soraa’s technology enables the LED to generate more lumens per area. Soraa’s lamp is based on its trademarked “GaN on GaN” materials, “a perfect crystal structure,” according to the company. Translation: The Soraa team figured out a way to create a combination of gallium-nitride top layer on gallium-nitride substrate.The competitive difference is that LEDs based on dissimilar crystal structures elsewhere result in lower performance. Soraa’s pure GaN crystal is up to one thousand times purer than GaN on sapphire or GaN on silicon carbide substrates, according to the company. The MR16 will be available this quarter. Pricing information was not available at the time of this writing. © 2011 PhysOrg.com Bridgelux demonstrates silicon substrate LED that produces 135 lumens per watt Explore furthercenter_img More information: Soraa’s press release (PhysOrg.com) — Soraa, a Fremont, California company founded in 2008, this week launched its first product, a light that uses LEDS (light emitting diodes). The “Soraa LED MR16 lamp” is the “perfect” replacement for traditional halogen lamps, according to the release. The company says it is an ideal replacement for 50-watt halogen because the Soraa product delivers better beam and light quality. Soraa LED lamps use 75 percent less energy, deliver 10x lamp life, and produce higher quality light than halogen lamps, according to the company. Citation: Soraa LED light may dim 50-watt halogen rivals (2012, February 9) retrieved 18 August 2019 from https://phys.org/news/2012-02-soraa-dim-watt-halogen-rivals.htmllast_img read more

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Researchers replicate slime mold with brainless amoeboid robot that can move toward

first_img Explore further More information: Fluid-Filled Soft-Bodied Amoeboid Robot Inspired by Plasmodium of True Slime Mold, Advanced Robotics, Volume 26, Number 7, 2012 , pp. 693-707(15). dx.doi.org/10.1163/156855312X626316Abstract:This paper presents a fluid-filled soft-bodied amoeboid robot inspired by the plasmodium of the true slime mold. The significant features of this robot are 2-fold. (i) The robot has a fluid circuit (i.e., cylinders and nylon tubes filled with fluid), and a truly soft and deformable body stemming from real-time tunable springs — the former seals protoplasm to induce global physical interaction between the body parts and the latter is used for elastic actuators. (ii) A fully decentralized control using coupled oscillators with a completely local sensory feedback mechanism is realized by exploiting the global physical interaction between the body parts stemming from the fluid circuit. The experimental results show that this robot exhibits adaptive locomotion without relying on any hierarchical structure. The results obtained are expected to shed new light on the design scheme for autonomous decentralized control systems.via TechnologyReview (PhysOrg.com) — Takuya Umedachi has been working for several years to build a robot that can replicate the simple actions of the common slime mold, an organism that can move towards something it desires without benefit of a brain or central nervous system. Now Umedachi and his colleagues at Hiroshima University have built such a robot and have published the specifics of how it works in the journal Advanced Robotics. Robot fish found able to lead real fish (w/ video) The amoeboid robot as they call it has two main parts, an air filled balloon center surrounded by fluid filled cylinders. The cylinders are connected to one another via springs attached to force sensors on one end and a DC motor on the other. Each spring also has a winding/unwinding component to allow the spring to pull the cylinder when it’s in move mode. And that is one of the keys of movement for the amoeboid. Each cylinder has a move and stuck mode. When in move mode, the cylinder can be slid in the direction of the attractant. When it stuck mode, it adheres to the surface (via electromagnet) to prevent the cylinder from being pushed backwards when other cylinders around it are moving. To get it to move towards an attractant, coupled oscillators are used to create a distributed sensory feedback loop. The whole point of the amoeboid is its simplicity. It doesn’t require any programming or prior learning to do what it does, and that is just one thing. Move, slowly, bloblike, in the direction of the attractant. And because it’s soft-bodied, its shape alters automatically to allow it to fit though small spaces and once on the other side, to resume its most natural position. And while commercial applications are certainly limited to such things as delivering materials in hostile surroundings during an emergency, or providing sensor readings in a similar environment, they are beside the point. The real importance of the amoeboid is in the brilliance of its design and how what has been learned can be applied to other robotic applications. It’s not difficult, for example, to imagine future robots that launch an amoeboid when circumstances warrant, or the integration of amoeboid characteristics into household appliances to allow them to clean our floors without having to map everything out in advance.center_img 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: Researchers replicate slime mold with brainless amoeboid robot that can move toward an attractant (2012, March 14) retrieved 18 August 2019 from https://phys.org/news/2012-03-replicate-slime-mold-brainless-amoeboid.html © 2011 PhysOrg.com The amoeboid is clearly still in its infancy, but portends many new and exciting advances in the robotics field that will come about due to out-of-the-box type thinking as is clearly demonstrated by Umedachi and his team.last_img read more

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Researchers demonstrate Heisenberg uncertainty principle at macro level

first_img © 2013 Phys.org (Phys.org)—Physicists working at the University of Colorado have succeeded in demonstrating one of the major tenets of quantum mechanics—namely the Heisenberg uncertainty principle—at the macro level. In their paper published in the journal Science, the team describes how a small but still visible drum they built in their lab, outfitted with mirrors, a laser and a detector, demonstrated that it was not possible to measure a photon’s position and momentum simultaneously. It was Heisenberg who famously noted that it was impossible to measure the momentum of an object and its position at the same time. As an example, he pointed out that using a microscope to look at a single electron, would require shining light on it. Those photons would cause the electron to move slightly, changing its momentum. Up till now, researchers testing or demonstrating this principle have worked at the micro level because attempting to do so with objects large enough to be seen with the naked eye seemed impossible due to the many variables at play. In this new research, the team in Colorado showed that this not necessarily the case.They started by building a square drum frame out of silicon, with each side 0.5 millimeters long. They then stretched a thin film of silicon nitride over the skin to create the drum head. The drum was placed in a vacuum between two very tiny mirrors and was chilled to just 4 degrees above absolute zero to eliminate extraneous noise. The experiment was conducted by shooting a laser at the drum and measuring how much the head was distended by the photons striking it as they were bounced back and forth between the mirrors. As more photons struck the drum, greater fluctuations occurred in the measurements recorded, distorting the readings, and proving that the Heisenberg uncertainty principle can indeed be demonstrated with objects large enough to be seen with the naked eye.The results of the experiment could also have an impact elsewhere, as researchers in Washington and Louisiana are planning a similar experiment over a much more vast scale—they will be seeking to measure gravitationally waves, which the theory of relatively says, should cause a change in distance between two objects. Their experiment will involve the use mirrors as well, but instead of a small drum, they will be trying to measure what happens when two black holes merge. Journal information: Science More information: Science. Vol 339, February 13, 2013, p. 801. doi: 10.1126/science.1231282 Are you certain, Mr. Heisenberg? New measurements deepen understanding of quantum uncertainty 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: Researchers demonstrate Heisenberg uncertainty principle at macro level (2013, February 15) retrieved 18 August 2019 from https://phys.org/news/2013-02-heisenberg-uncertainty-principle-macro.html Explore furtherlast_img read more

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Nanoscientists develop new kind of portable water purification system

first_imgWater purification device undergoing field trials in India and its performance evaluation. (A) Schematic diagram of the device. (B) Actual photograph of the device. Construction and assembly of the device are simple and can be done locally. The antimicrobial composition is used as granules and kept in the membrane filter. Carbon block is positioned just before the tap. Carbon block may also be used as a multilayer axial block, comprising adsorbents for specific regional contaminants such as arsenic, iron, and lead. Credit: PNAS, doi: 10.1073/pnas.1220222110 Journal information: Proceedings of the National Academy of Sciences Citation: Nano-scientists develop new kind of portable water purification system (2013, May 7) retrieved 18 August 2019 from https://phys.org/news/2013-05-nano-scientists-kind-portable-purification.html © 2013 Phys.org Scientists evaluate different antimicrobial metals for use in water filters (Phys.org) —Researchers at India’s Institute of Technology Madras have developed a new kind of portable water purification system based on nanoparticle filtration. In their paper published in the Proceedings of the National Academy of Sciences, the team explains how their new device does its job—it employs nanoparticles to remove not just biological hazards, but toxic heavy metals as well.center_img The researchers note that access to clean drinking water is still a major worldwide problem—making it available to everyone, they say, would save approximately 2 million lives a year (approximately 42.6 percent of deaths are due to diarrhea alone and impact mostly children). To help reach the UN millennium development goal of doubling the number of people with sustainable access to safe drinking water by 2015, the team has been applying nanoparticle technology to the problem. The system they have developed is a two-stage filtration process that provides 10 liters of clean water in just an hour’s time. The biggest challenge, the team says, was figuring out how to deliver silver ions into the water to be processed, without using any electricity. The process also had to use a minimal amount of silver ions to meet international safety standards. The answer, they say, was to use a new material that employs silver nanoparticles that are trapped in tiny cage-like structures made of other clay materials.Other nanoparticles are used to create other materials that serve as filters, killing microbes and sucking heavy metals out of the water, making it safe to drink or use for cooking. The first stage of the process kills viruses, bacteria and other dangerous micro-biota. The second stage absorbs heavy metals such as lead and arsenic.The result is an extremely inexpensive portable water purification device—the system cost is comparable to other portable filtration systems, but the processing itself comes to less than $3 per year. The filters are good for approximately one year (3,600 liters) and filtration can be run more than once per day if needed. The researchers believe their device is capable of providing all the drinking water a family of four would need.The researchers have not yet made it clear who will manufacture the new device or when it might be made available for sale. Explore further More information: Biopolymer-reinforced synthetic granular nanocomposites for affordable point-of-use water purification, PNAS, Published online before print May 6, 2013, doi: 10.1073/pnas.1220222110AbstractCreation of affordable materials for constant release of silver ions in water is one of the most promising ways to provide microbially safe drinking water for all. Combining the capacity of diverse nanocomposites to scavenge toxic species such as arsenic, lead, and other contaminants along with the above capability can result in affordable, all-inclusive drinking water purifiers that can function without electricity. The critical problem in achieving this is the synthesis of stable materials that can release silver ions continuously in the presence of complex species usually present in drinking water that deposit and cause scaling on nanomaterial surfaces. Here we show that such constant release materials can be synthesized in a simple and effective fashion in water itself without the use of electrical power. The nanocomposite exhibits river sand-like properties, such as higher shear strength in loose and wet forms. These materials have been used to develop an affordable water purifier to deliver clean drinking water at US $2.5/y per family. The ability to prepare nanostructured compositions at near ambient temperature has wide relevance for adsorption-based water purification. 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

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Engineers discover unique fingerprint for cell phones

first_img © 2013 Phys.org Explore further The development of the cell phone has led to new advances in both law enforcement and criminal evasion. Police officers use cell phones to communicate with one another, as do criminals. It didn’t take long, however, for the police to figure out that they could track criminals as they talk on their cell phones using triangulation of cell towers. To keep from getting caught, criminals began using new evasion tactics such as modifying the built-in ID code on their cell phone or swapping out SIM cards—doing so made it nearly impossible for law enforcement to track them down by their cell phone signals alone. This new advance by the engineers in Germany appears likely to thwart that strategy.Working at the Technical University of Dresden, engineers Jakob Hasse, Thomas, Gloe and Martin Beck found that each of the separate components inside a cell phone has a degree of error. When all of the errors are taken together, as seen in the digital signal sent to a cell tower, the result can be read as a unique digital signal—or fingerprint. That means that no matter what criminals do to their cell phone—short of swapping out internal components—their phones will continue to emit a unique signal that can be read by a device and used to separate it out from all the other cell phone signals. Once that’s done the location of the phone—and possibly the criminals—can be calculated using triangulation of cell towers.Unfortunately, a device to read and recognize the unique signature of cell phones is still in the research and development stage, though the engineers on the project report a nearly 98 percent success rate in correctly identifying a signal. Law enforcement would surely like to see that number bumped to 100 to avoid finding themselves occasionally raiding the wrong house. (Phys.org) —Law enforcement officials may soon have a new tool at their disposal—a device that can distinguish between cell phones based on their digital signal. In the never ending game of cat-and-mouse between law enforcement and criminals, this new advancement may give the good guys the upper hand—all due to a discovery by a team of engineers in Germany. 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. More information: Forensic Identi?cation of GSM Mobile Phones, Jakob Hasse et al. (PDF)via Newscientist Overall Procedure of Feature Extraction. Credit: Forensic Identification of GSM Mobile Phones, Jakob Hasse et al. Many US police use cell phones to track: study Citation: Engineers discover unique fingerprint for cell phones (2013, August 2) retrieved 18 August 2019 from https://phys.org/news/2013-08-unique-fingerprint-cell.htmllast_img read more

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Water soluble gold nanoparticle supraspheres can hold 2 million guest molecules

first_imgIn an effort to keep the larger supraspheres from precipitating out of solution, Wang et al. replaced the remaining polyoxometalates at the cluster-water interface with thiolate-capping ligands. It is the chemical properties of these ligands that allowed for the selective uptake of certain hydrophobic guests over others. They experimented with three caps: a positively changed one, a negatively charged one, and mercapto-polyethylene glycol (PEG-SH). For their model hydrophobic guest, Wang, et al. used bisphenol A (BPA). Because PEG-S-capped supraspheres are soluble in both water and methylene chloride, they confirmed that guest uptake was due to hydrophobic effects. Adsorption properties were determined with ultraviolet-visible spectroscopy and 1H NMR. They confirmed that each suprasphere hosts the same number of BPA molecules and that the number of guests was around 2 million per suprasphere.They then explored host-guest properties with other hydrophobic guests. They tested azulene (a dye, TNT (an explosive), RDX (an explosive), alachlor (a common herbicide), para-xylene, and para-dichlorobenzene. At first, they did not observe guest uptake with TNT, which they attributed to kinetic effects. By changing the capping molecules from PEG-SH to a mixture of PEG-SH and hex-SH, they observed the uptake of over 2 million TNT or RDX molecules. This idea of kinetically controlling the uptake of certain guests was used to chemo-selectively adsorb BPA over TNT in a solution containing both molecules.Analysis of the suprasphere architecture indicated that there was an extensive internal hydrophobic porous system that allowed guests to diffuse throughout the suprasphere structure. The authors described the interior of the suprasphere as a percolated network of hydrophobic holes that can house the more than 2 million guest molecules.Gold nanoparticle supraspheres are a relatively new area for host-guest chemistry. This research shows how functionalizing the surface of the nanoparticles with a hydrophilic leaving group will allow the formation of water soluble supraspheres that are able to easily and selectively adsorb and release guests. Citation: Water soluble gold nanoparticle supraspheres can hold 2 million guest molecules (2016, December 8) retrieved 18 August 2019 from https://phys.org/news/2016-12-soluble-gold-nanoparticle-supraspheres-million.html Journal information: Nature Nanotechnology Explore further (Phys.org)—Researchers from Ben-Gurion University of the Negev in Israel and École Polytechnique Fédérale de Lausanne in Switzerland have developed porous 200 nm supraspheres from gold nanoparticles whose surface is functionalized with polyoxometalate leaving groups that allows for dispersion in pure water. The hydrophobic effect promotes the spontaneous adsorption of alkyl and alkylaromatic guests. © 2016 Phys.org a, Schematic showing how citrate ligands are replaced by AlW11O399- (1), to give 1-protected Au NPs. A reaction with hexanethiol then leads to the formation of colloidal supraspheres. The structure of 1 is shown in polyhedral notation: W(VI)-centred polyhedra are in blue (oxygen atoms are present at all vertices) and the centrally located, four-coordinate Al(III) ion is in red; b, Cryo-TEM images illustrating colloidal suprasphere formation: (i) and (ii) show individual citrate- and 1-protected Au NPs, respectively; (iii) shows a representative intermediate-sized colloidal suprasphere, with a radius of around 45 nm. Scale bar, 10 nm; c, The uptake of bisphenol A (black dots) by the PEG capped supraspheres from aqueous solution; d, Illustration (drawn to scale) of an Oh-symmetry hole hosting approximately 1 nm bisphenol A guests. Credit: Wang et al. 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. In their research article in Nature Nanotechnology, Wang et al. demonstrate that their leaving groups are easily displaced by hexane thiol, allowing for the formation of suprasphere colloids in water and uptake of around 2 million hydrophobic guests, a mass-per-volume level that rivals zeolites and metal-organic frameworks. Furthermore, by tailoring the surface of the suprasphere, they were able to chemo-selectively control the uptake of guest molecules.While there have been several gold nanoparticle suprasphere studies reported in the literature, none of them explore the hydrophobic effect for host-guest interactions. Those interactions largely arise from the formation of aggregates. Supraspheres are gold nanoparticle colloids that are held together by weak interactions between alkylthiolate ligands, which form a hydrophobic monolayer around the nanoparticles. This results in aggregates in pure water.However, this same hydrophobic effect can be used to promote host-guest interactions. Supraspheres are highly porous compounds that can serve as a reservoir of hydrophobic cavities for non-polar guests in an aqueous environment.To avoid the problem of uncontrolled precipitation, Wang et al. functionalized the surface of the gold nanoparticles with negatively charged cluster anion, AlW11O399-. They then incrementally added small amounts of hexane thiols (hex-SH) to the solution. Domains of hydrophobic thiol clusters and hydrophilic polyoxometalate clusters formed on the surface of the gold nanoparticles. This eventually leads to the controlled hydrophobic assembly of supraspherical clusters, as evidenced by surface plasmon resonance studies and in situ imaging by cryogenic transmission electron microscopy. These clusters are soluble in water.Importantly, because there is a linear correlation between the addition of hex-SH and the average hydrodynamic radius, they were able to tailor supracluster formation. Additional studies confirmed supraspheres were formed in water, but that larger supraspheres (approximately 200 nm) were less stable than intermediate-sized ones (approximately 150 nm). Energetics of the adsorption of ethanol on calcite nanoparticles More information: Yizhan Wang et al. Host–guest chemistry with water-soluble gold nanoparticle supraspheres, Nature Nanotechnology (2016). DOI: 10.1038/nnano.2016.233AbstractThe uptake of molecular guests, a hallmark of the supramolecular chemistry of cages and containers, has yet to be documented for soluble assemblies of metal nanoparticles. Here we demonstrate that gold nanoparticle-based supraspheres serve as a host for the hydrophobic uptake, transport and subsequent release of over two million organic guests, exceeding by five orders of magnitude the capacities of individual supramolecular cages or containers and rivalling those of zeolites and metal–organic frameworks on a mass-per-volume basis. The supraspheres are prepared in water by adding hexanethiol to polyoxometalate-protected 4 nm gold nanoparticles. Each 200 nm assembly contains hydrophobic cavities between the estimated 27,400 gold building blocks that are connected to one another by nanometre-sized pores. This gives a percolated network that effectively absorbs large numbers of molecules from water, including 600,000, 2,100,000 and 2,600,000 molecules (35, 190 and 234 g l−1) of para-dichorobenzene, bisphenol A and trinitrotoluene, respectively.last_img read more

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Methane oxidation on the plus side – A selective industrial route to

first_img Reaction profile for methane sulfonation. Pressure of CH4 is plotted versus time under (A) standard conditions using 0.9 mol % electrophilic initiator (Figure 2, entry 2) and (B) successive additions of CH4 (Fig 2, entry 3). The inset in (A) shows a zoomed-in view of region i. Credit: Science, doi: 10.1126/science.aav0177. Direct functionalization of methane to form value-added products is a challenge due to potential overoxidation in many reaction environments and sulfonation is an attractive approach to achieve the selectivity of interest. In the practical process, Díaz-Urrutia and Ott produced methanesulfonic acid (MSA) using only two main reactants; methane and sulfur trioxide. They achieved 99 percent selectivity and yield of MSA in the work. The scientists based the electrophilic initiator on a sulfonyl peroxide derivative, which they protonated under superacidic conditions to produce a highly electrophilic oxygen atom capable of activating a C-H bond of methane. They proposed mechanistic studies to support the formation of a cation methenium (CH3+)as a key intermediate during the reaction. The proposed method is scalable with reactors connected in a series to prospectively produce up to 20 metric tons of MSA per year. While large-scale fracking techniques and biogas production has provided access to large quantities of inactive methane, the largest chemical transformation of methane remains confined to the highly energy demanding Fischer-Tropsch processes. At present, methane is industrially converted to Syngas, a mixture of carbon monoxide and hydrogen, to form useful products including methanol and Fischer-Tropsch hydrocarbons, which are synthesized in subsequent steps. The production of syngas is severely cost-limiting, however; “MegaMethanol” plants or the Fischer-Tropsch pearl complex in Qatar exceed 10 million metric tons (MT) of the total annual hydrocarbon production. As a result, the direct conversion of methane to valuable products on an economically viable technique are of extreme interest. Methane is a major component in natural gas and one of the most difficult molecules for controlled activation, since most of the product results in carbon dioxide. The industrial conversion of methane to alcohol derivatives is typically based on a circuitous route that begins with overoxidation to carbon monoxide. Although more direct approaches have shown promise in highly acidic media at a small scale, they are not quite cost-effective. In a recent study now published in Science, Christian Díaz-Urrutia and Timo Ott at the R&D department of Grillo-Werke AG Company describe a reaction at a pilot-plant scale that directly combined methane (CH4) and sulfur trioxide (SO3) in sulfuric acid (H2SO4) to form methanesulfonic (CH4O3S) acid without by-products. The reaction appeared to proceed via a cationic chain mechanism initiated by adding a low concentration of sulfonyl peroxide, propagated by methenium (CH3+) molecules. To afford pure MSA, Díaz-Urrutia and Ott completed the process by a final distillation step. They then recycled the remaining mixture of sulfuric acid and MSA to the first reactor for continued regeneration of sulfur trioxide and sulfuric acid (SO3 and H2SO4). Using the four reaction chambers of the setup, the scientists were able to produce 200 kg of pure MSA per week, amounting to two to three metric tons in 80 days. In this way, the demonstrated combination of high selectivity, conversion and atom economy made the process ideal for large-scale valorization of the readily available methane and sulfur trioxide reagents. If this new process of methanesulfonic acid becomes successful in the market, cheaper reagents will be able to replace the mineral acids presently in use. However, even if the production of MSA were to increase dramatically, the amount of methane consumed in the process would still be dwarfed by the amounts flared. Nevertheless, the work of Díaz-Urrutia and Ott predicts a new synthetic chemical process to synthesize an interesting chemical, allowing the scientists to envision a range of value-added products to be derived from methane or higher alkanes using this route of superacid chemistry in the future. GC-FID Chromatograms. A) GC-FID chromatogram of the gas phase of the reactor (100 bar) before sulfonation of methane has occurred. B) GC-FID chromatogram of the gas phase after (~40 bar) the sulfonation of methane has occurred (16 h, fuming sulfuric acid 36%, 500C). Credit: Science, doi: 10.1126/science.aav0177. More information: Christian Díaz-Urrutia et al. Activation of methane to CH3+: A selective industrial route to methanesulfonic acid, Science (2019). DOI: 10.1126/science.aav0177 Ferdi Schüth. Making more from methane, Science (2019). DOI: 10.1126/science.aaw7738 Christopher D. Elvidge et al. The potential role of natural gas flaring in meeting greenhouse gas mitigation targets, Energy Strategy Reviews (2018). DOI: 10.1016/j.esr.2017.12.012 Eric C. D. Tan et al. Reduction of greenhouse gas and criteria pollutant emissions by direct conversion of associated flare gas to synthetic fuels at oil wellheads, International Journal of Energy and Environmental Engineering (2018). DOI: 10.1007/s40095-018-0273-9 (A) Proposed ionic reaction mechanism for the C–H activation of CH4 in the selective production of MSA (Methanesulfonic acid). (B) Advantages of the cationic pathway over the radical pathway. T, temperature. Credit: Science, doi: 10.1126/science.aav0177 Explore further Making methane into more than fuel. Different commercialization pathways for methane, including the new process by Díaz-Urrutia and Ott. Commercial demand for products that would use the amount of methane that is flared exists only for compounds usable as fuels (methanol or higher hydrocarbons). Credit: Science, doi: 10.1126/science.aav0177 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. Sulfonation of methane to MSA. (A) Schematic of the Díaz-Urrutia and Ott process. The reaction proceeds as a cascade through reactors connected in series. The pilot plant could produce up to 20 metric tons of MSA per year. The excess SO3 is quenched in reactor Q, the CH4 excess stream and the MSA/H2SO4 sump stream are recycled back to reactor 1, and the MSA-enriched mixture is distilled in column D to obtain pure MSA. (B) The concentration of MSA increases as it passes through the reactors. (C) Oblong quartz window reactor with gas impeller, for improved CH4 mixing. Credit: Science, doi: 10.1126/science.aav0177. © 2019 Science X Network Citation: Methane oxidation on the plus side – A selective industrial route to methanesulfonic acid (2019, April 2) retrieved 18 August 2019 from https://phys.org/news/2019-04-methane-oxidation-side-industrial-route.html In this context, the potential to sulfonate methane (CH4) to methanesulfonic acid (CH4O3S, MSA) has achieved substantial attention due to the abundance of both raw materials and the ability for its rapid integration into existing industrial chemical processes. MSA is biodegradable and nonoxidizing with potential applications in metal recycling, energy storage and biodiesel production. Preceding work on methanesulfonation suffered from low yields and conversions, due to free-radical recombination, resulting in undesired side-products such as ethane, rendering the methods unsuitable for large-scale production. Technically, the balance between reactivity and selectivity required by an industrial process can be provided by superacid chemistry. Díaz-Urrutia and Ott reported on the treatment of oleum (20 to 60 percent sulfur trioxide) with CH4 at approximately 500C using less than 1 mol percentage of the electrophilic initiator to form MSA with 99 percent yield and 99 percent selectivity. CH4(g) + SO3(l) → CH3SO3H(l) Journal information: Science Since the initial results were very promising, the scientists built a pilot plant facility and tested the economic and technical feasibility of industrial scale MSA production. Díaz-Urrutia and Ott constructed the plant with a projected capacity of 20 metric tons/year of MSA production, based on their laboratory-scale batch reactions, and accounted for methane solubility and recycling, as well as for the concentration of sulfur trioxide and methane. This configuration allowed the scientists to constantly increase the concentration of MSA as the reaction mixture passed through the reactors. When they used gas chromatography with flame-ionization detection (GC-FID) to monitor the samples, they did not detect the presence of higher alkanes in the recycled stream of methane or any other radical recombination products, allowing its direct use as feedback stock for the cascade reaction. The scientists first studied the reaction in a batch system to optimize experimental conditions and gain further insight into the reaction mechanism. For the electrophilic initiator, they used monomethylsulfonylperoxide sulfuric acid (MMSP) to improve technical feasibility. For increased productivity, they used a four-liter reactor instead of a 400-mL reactor, owing to larger quantities of CH4 forming in the headspace of the larger reactor. The scientists were thus able to maintain constant amounts of methane throughout the reaction for higher yields of MSA. They used an optimal temperature of 500C to achieve more than 99 percent selectivity towards MSA, whereas previous radical pathways had similar results at higher temperatures (850C) due to thermal decomposition of the sulfonyl peroxide electrophilic initiator. Low-temperature experiments could also offer high conversion and MSA selectivity, but required longer reaction times. Díaz-Urrutia and Ott comparatively provided insights to support a non-radical mechanism in the present work. When the scientists examined the reaction profile of the experiment, they observed an induction period immediately after addition of the electrophilic reactor, where the amount of MSA (product) was proportional to the initial quantity of MMSP (initiator). At stage two of the reaction profile, they observed the solubility of CH4 decrease with increasing pressure in the reactor. The activation energy of the process was determined to be 111±1 kJ/mol, similar to those previously reported. The described cationic pathway occurred under very specific conditions. The researchers achieved high selectivity through electronic changes in electrophilic substitutions, as opposed to the previously reported free-radical based atom abstraction reactions. A new way to directly convert methane to methanol using gold-palladium nanoparticleslast_img read more

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Fatstacking it

first_imgFatburger is a chain that has been associated with incredible burgers since 1952. Spread across the world, the chain made its entry into India this year. And greedy as we are, we could not wait to check them out. The joint at Cyberhub has a cozy American diner type feel to it. Makes you feel comfortable the very moment you walk in and grab a menu. We started off with the Amritsari Onion Rings that come with a generous sprinkling of Tikka masala that adds a very nice zing. We also had the chicken wings in the tangy Barbeque Chipotle sauce which comes to you with the blue cheese dip. Very well made. Also Read – CBI examines former ISRO chief RadhakrishnanWe obviously made very sure we kept space for the burgers! We picked the Fat Greek, the Red Scorcher and the Tenderloin burgers and added fried egg and bacon to it. Fatburger has an incredible thing called the Fatstack – which basically means that they add a second patty to the burger. So the normal buger gains a good few inches in height thanks to the juicy second patty! What’s not to love?The incredible mouthfull along with the runny friend egg and bacon – we were in burger heaven. And handsdown this place has the best value-for-money burgers in the Capital and NCR. At the prices they have, what they serve is nothing short of incredible. Meal for two comes to about Rs 800 (without taxes).last_img read more

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From the period medieval

first_imgArt Heritage Collection – a show that displays the collection of designer soft furnishing items like bed linen, cushion covers, dining mats, etc. inspired  by the traditional art of the medieval period  and nineteenth century British period is being organised in the Capital. The event that started off on 15 October is conceptualised by Anjali Jain .Aesthetically designed, these colourful items are influenced by the miniature paintings of the Mughal and Rajput style. Some are also inspired by the exotic geometrical designs of  the jaalis and jharokhas of the Rajput and Muslim architecture. Also Read – ‘Playing Jojo was emotionally exhausting’The other half is inspired by the Bengal woodcut designs of the  nineteenth century. Paintings by the British and Indian artists  reflecting  the lifestyle of those bygone days are also included in the designs.The collection is a medley of chirpy bird designs, the exotic romance of the Kishangarh and Rajput paintings, the majesty and exuberance of the Mughal  paintings and the geometric perfection and appeal of the Mughal architecture. The show could perhaps be highlighted by a song and dance Ballet mainly Kathak based showing the Radha- Krishna romance, the court dances of the mughals easing out to the times of the nautch girls of the era and western ballroom dances of the Sahibs.Where: Select City Walk, Saket  When: On till 19th october TIMINGS: 11 am to 11 pmlast_img read more

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