Citation: Gravity waves could hold key to supersymmetry (2008, November 5) retrieved 18 August 2019 from https://phys.org/news/2008-11-gravity-key-supersymmetry.html (PhysOrg.com) — “In Geneva,” Anupam Mazumdar tells PhysOrg.com, “there is a big effort to discover supersymmetry particles at the Large Hadron Collider. But that is not the only way to find these particles. We should also be able to see supersymmetry in the sky through the observation of gravitational waves.” Mazumdar, a physicist at Lancaster University in Britain, worked with Alex Kusenko at the University of California, Los Angeles to simulate what kind of frequency distribution would result from the fragmentation of unstable scalar condensate. The two say that a number of devices, including the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO), the Laser Interferometer Space Antenna (LISA) and the Big Bank Observer (BBO), would be able to detect the gravitational waves they describe in “Gravitational waves from fragmentation of a primordial scalar condensate into Q-balls,” which has been accepted for publication in Physical Review Letters. Supersymmetry is speculated to go beyond the standard model of physics to introduce particles that solve some of the problems that cannot be solved using only the particles that have been observed thus far. In supersymmetry, the standard particles we are familiar with have superpartners that differ from the standard by half a unit of spin. For example, the superpartners of standard model fermions are s-fermions. “The gravity wave is fundamental to theory from Einstein,” Mazumdar says. “But we have not yet seen it in the frequencies described. However, primordial inflation is one of the many cosmic sources that could produce these waves.” The gravitational waves described by Mazumdar and Kusenko begin as a condensate formed in the early universe of s-fermions. “At a certain point,” Mazumdar explains, “the condensate starts oscillating due to the presence of scalar, s-fermion, masses, whose masses are roughly determined by the scale of supersymmetry breaking. Due to the inherent nature of quantum corrections the condensate is not absolutely stable and fragments during the coherent oscillations. The fragmentation process leads to the formation of non-topological solitons, known as Q-balls. Since the fragmentation process is so violent and anisotropic, it excites gravity waves.” These waves, he says, have an amplitude and frequency detectable by LIGO.Mazumdar says that, while many hope to find evidence of supersymmetry when the LHC is fully operational, it is not the only place where one can look for the signs of supersymmetric particles. Besides, he points out, evidence of supersymmetry may not be found at the LHC. Looking to the cosmos, then, would be another option. This is where the sophisticated cosmological observation devices – especially LIGO – come in. “Our model shows frequencies exactly where LIGO is sensitive,” he says. “We also show a place where the frequency would be distinguishable from binaries, black holes and pulsars, which would also form gravity waves.” “The frequency we show has a broader spectrum, and its uniqueness would provide evidence of this s-fermion condensate,” he continues. “Such a condensate could have also inflated the primordial universe, while explaining the origin of tiny perturbations in the cosmic microwave background radiation.”However, Mazumdar admits, it may take some time to detect these waves and take the observations. “We’re hoping to detect these in four to five years at LIGO,” he says. “Scientists may find evidence of supersymmetry at the LHC, but we are hoping to find links to it in cosmology.”Article reference: Kusenko, Alexander and Anupam, Mazumdar “Gravitational waves from fragmentation of a primordial scalar condensate into Q-balls” arxiv.org/abs/0807.4554.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. 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.
One of the biggest problems researchers face is designing an inexpensive battery that can be recharged many times. Today’s lead-acid batteries typically last only a few hundred charge cycles, while lithium-ion batteries can last up to 1,000 charge cycles. Now in a new study, researchers led by Yi Cui, a materials science and engineering professor at Stanford University, have designed and demonstrated a battery cathode that lasts for 40,000 charge cycles while maintaining 83% of its charge-holding capacity. The results are published today in Nature Communications.The cathode consists of commonly available materials: crystalline nanoparticles made of Prussian Blue (an iron and cyanide compound) in which half of the iron is replaced with copper. The nanoparticles are then coated on a carbon substrate, which is immersed in an electrolyte solution of potassium nitrate.The researchers plan to design similar anodes to go along with the cathodes, which could then be used in a battery that Cui’s team is working on. That battery’s chemistry is similar to that of lithium-ion batteries but uses materials that are cheaper and more abundant, such as sodium and potassium ions and a water-based electrolyte, rather than organic solvent-based electrolytes.In addition to its high number of charge cycles, the cathode also has high efficiency of 99%. Although the cathode’s charge capacity is not as high as that of other batteries, its overall performance in a future battery could still make it advantageous in terms of overall cost. Citation: Battery electrode’s 40,000 charge cycles look promising for grid storage (2011, November 22) retrieved 18 August 2019 from https://phys.org/news/2011-11-battery-electrodes-grid-storage.html Explore further An electrode made of a copper- and iron-based nanomaterial is immersed in a potassium nitrate electrolyte. Image credit: Colin Wessells, et al. (PhysOrg.com) — While researchers continue to improve solar and wind energy technologies, having a battery that can store the energy until it’s needed by the grid is another critical component for using renewable energy on a large scale. More information: Colin D. Wessells, et al. “Copper hexacyanoferrate battery electrodes with long cycle life and high power.” Nature Communications 2, Article number: 550, DOI:10.1038/ncomms1563Below is a press release issued by Stanford University:Nanoparticle electrode for batteries could make grid-scale power storage feasibleThe sun doesn’t always shine and the breeze doesn’t always blow and therein lie perhaps the biggest hurdles to making wind and solar power usable on a grand scale. If only there were an efficient, durable, high-power, rechargeable battery we could use to store large quantities of excess power generated on windy or sunny days until we needed it. And as long as we’re fantasizing, let’s imagine the battery is cheap to build, too.Now Stanford researchers have developed part of that dream battery, a new electrode that employs crystalline nanoparticles of a copper compound.In laboratory tests, the electrode survived 40,000 cycles of charging and discharging, after which it could still be charged to more than 80 percent of its original charge capacity. For comparison, the average lithium ion battery can handle about 400 charge/discharge cycles before it deteriorates too much to be of practical use.”At a rate of several cycles per day, this electrode would have a good 30 years of useful life on the electrical grid,” said Colin Wessells, a graduate student in materials science and engineering who is the lead author of a paper describing the research, published this week in Nature Communications.”That is a breakthrough performance – a battery that will keep running for tens of thousands of cycles and never fail,” said Yi Cui, an associate professor of materials science and engineering, who is Wessell’s adviser and a coauthor of the paper.The electrode’s durability derives from the atomic structure of the crystalline copper hexacyanoferrate used to make it. The crystals have an open framework that allows ions – electrically charged particles whose movements en masse either charge or discharge a battery – to easily go in and out without damaging the electrode. Most batteries fail because of accumulated damage to an electrode’s crystal structure.Because the ions can move so freely, the electrode’s cycle of charging and discharging is extremely fast, which is important because the power you get out of a battery is proportional to how fast you can discharge the electrode.To maximize the benefit of the open structure, the researchers needed to use the right size ions. Too big and the ions would tend to get stuck and could damage the crystal structure when they moved in and out of the electrode. Too small and they might end up sticking to one side of the open spaces between atoms, instead of easily passing through. The right-sized ion turned out to be hydrated potassium, a much better fit compared with other hydrated ions such as sodium and lithium.”It fits perfectly – really, really nicely,” said Cui. “Potassium will just zoom in and zoom out, so you can have an extremely high-power battery.”The speed of the electrode is further enhanced because the particles of electrode material that Wessell synthesized are tiny even by nanoparticle standards – a mere 100 atoms across.Those modest dimensions mean the ions don’t have to travel very far into the electrode to react with active sites in a particle to charge the electrode to its maximum capacity, or to get back out during discharge.A lot of recent research on batteries, including other work done by Cui’s research group, has focused on lithium ion batteries, which have a high energy density – meaning they hold a lot of charge for their size. That makes them great for portable electronics such as laptop computers.But energy density really doesn’t matter as much when you’re talking about storage on the power grid. You could have a battery as big as a house since it doesn’t need to be portable. Cost is a greater concern.Some of the components in lithium ion batteries are expensive and no one knows for certain that making the batteries on a scale for use in the power grid will ever be economical.”We decided we needed to develop a ‘new chemistry’ if we were going to make low-cost batteries and battery electrodes for the power grid,” Wessells said.The researchers chose to use a water-based electrolyte, which Wessells described as “basically free compared to the cost of an organic electrolyte” such as is used in lithium ion batteries. They made the battery electric materials from readily available precursors such as iron, copper, carbon and nitrogen – all of which are extremely inexpensive compared with lithium.The sole significant limitation to the new electrode is that its chemical properties cause it to be usable only as a high voltage electrode. But every battery needs two electrodes – a high voltage cathode and a low voltage anode – in order to create the voltage difference that produces electricity. The researchers need to find another material to use for the anode before they can build an actual battery.But Cui said they have already been investigating various materials for an anode and have some promising candidates.Even though they haven’t constructed a full battery yet, the performance of the new electrode is so superior to any other existing battery electrode that Robert Huggins, an emeritus professor of materials science and engineering who worked on the project, said the electrode “leads to a promising electrochemical solution to the extremely important problem of the large number of sharp drop-offs in the output of wind and solar systems” that result from events as simple and commonplace as a cloud passing over a solar farm.Cui and Wessells noted that other electrode materials have been developed that show tremendous promise in laboratory testing but would be difficult to produce commercially. That should not be a problem with their electrode.Wessells has been able to readily synthesize the electrode material in gram quantities in the lab. He said the process should easily be scaled up to commercial levels of production.”We put chemicals in a flask and you get this electrode material. You can do that on any scale,” he said.”There are no technical challenges to producing this on a big-enough scale to actually build a real battery.”Huggins is a coauthor of the Nature Communications paper. 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. Sulfur in hollow nanofibers overcomes challenges of lithium-ion battery design © 2011 PhysOrg.com
Climate change will raise the sea level in the Gulf of Finland (Phys.org) —A new study conducted by researchers at the University of Texas’ Center for Space Research, indicates that sea level rise between 2005 and 2011 was due primarily to glacial and polar ice shelf melting. In their paper published in Nature Geoscience, the team describes how they studied data from satellites and ocean surface sensors to measure changes in ocean mass and density which allowed them to calculate an average global sea level rise of nearly 2.4mm/year. © 2013 Phys.org Explore further Global mean sea level (GMSL) change. a, GMSL change observed by the TOPEX/Poseidon and Jason-1/2 satellite altimeters during the period 1993–2012. b, The same as in a, but for the most recent 7-year period (January 2005–December 2011). Credit: (c) NPG, Nature Geoscience (2013) doi:10.1038/ngeo1829 More information: Contribution of ice sheet and mountain glacier melt to recent sea level rise, Nature Geoscience (2013) doi:10.1038/ngeo1829AbstractChanges in global mean sea level primarily reflect the sum of three contributions: water mass changes in the oceans, water density changes, and variations in the volume of the ocean basins. Satellite altimetry data1, 2, 3, 4 suggest that sea level rose by about 2.39±0.48 mm yr−1 between 2005 and 2011. However, previous estimates5, 6, 7, 8, 9 of sea level rise from density and ocean mass changes were lower than the altimeter data indicate. Here we show that the gap in the sea level budget disappears when we combine gravity data from the GRACE (Gravity Recovery and Climate Experiment) satellite mission and temperature and salinity observations from the Argo programme collected between 2005 and 2011. The Argo data indicate a density-driven sea level rise of 0.60±0.27 mm yr−1 throughout this period. To estimate ocean mass change from the gravity data, we developed a forward modelling technique that reduces the bleeding of terrestrial signals into the ocean data. Our reassessment suggests an ocean mass contribution of 1.80±0.47 mm yr−1, for a total sea level rise of 2.40±0.54 mm yr−1, in agreement with the altimeter-based estimates. On the basis of the GRACE data, we conclude that most of the change in ocean mass is caused by the melting of polar ice sheets and mountain glaciers. This contribution of ice melt is larger than previous estimates10, but agrees with reports11, 12, 13 of accelerated ice melt in recent years. The researchers note that sea level changes come about in three main ways: changes in the mass of the water in the ocean, its density, and changes in the volume of ocean basins. To measure all of these over the period 2005 to 2011, the team studied data from the Gravity Recovery and Climate Experiment (GRACE) and from the Argo project (a global array of 3,500 profiling floats that record ocean temperatures and salinity on an ongoing basis.)Gravity data from GRACE allows researchers to measure the mass of the world’s oceans (divided into six regions) and thus the changes that occur over time. The data showed, the researchers report, a global increase in ocean mass that led to an average ocean level rise of 1.8mm/year during the years studied. They suggest the increase in mass was due to melting of the polar ice sheets and glaciers atop mountains around the globe.In studying data from Argo, the researchers found a reduction in the average density of the world’s oceans led to a rise in sea levels of approximately 0.6mm/year. The researchers did not delve into the nature of the decrease in sea water density, but the presumption is that it’s due to an increase in seawater temperature.To calculate the total average sea level rise over the years studied, the researchers added the rise due to an increase in ocean mass and the rise due to a reduction in average density—this gave them an average global sea level rise of 2.39mm/year. The researchers note their numbers reflect more rise than other studies have found but agree with those that have claimed sea levels are rising at an accelerated rate in more recent years. They also conclude that most of the change in global sea levels is due to melting of polar ice sheets and mountain glaciers. Citation: New study finds sea level rose 2.4 mm/year between 2005 and 2011 (2013, June 3) retrieved 18 August 2019 from https://phys.org/news/2013-06-sea-rose-mmyear.html Journal information: Nature Geoscience 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.
With a programme, which includes Art Projects, a Speakers’ Forum and a city wide Collateral Events schedule, the India Art Fair (IAF) has a by invitation VIP preview on 30 January, organisers announced in a statement on Saturday.The Fair, which held its first edition in 2008, has grown to be an epicentre for art in India, with a global reputation for being one of South Asia’s leading art fairs.The upcoming edition showcases 91 booths from India and across the world and aims to expose local and international artists to a large and diverse audience. Also Read – ‘Playing Jojo was emotionally exhausting’47 Indian galleries have been lined up to exhibit a breadth of modern and contemporary art practices including painting, sculpture, new media, installation and performance art.‘This year’s international galleries represent a dynamic mix, from returning European galleries, to a number of cutting edge newcomers, who all share the common goal to explore the Indian art market, forge key relationships and meet new collectors from South Asia,’ organisers said. Also Read – Leslie doing new comedy special with NetflixAn extensive Art Projects programme spanning the outdoor and indoor fair space is set to be focus of the fair this year.Highlights of the programme include ‘Listen Up!’ a public sound art project and a city-wide installation to make sound art publicly accessible through cellular phones.Among the rich selection of other participators, artist Dayanita Singh is set to present excerpts from her critically acclaimed File Room series, which has been shown this year at the Venice Biennale and the Hayward Gallery, London. Jose Garcia Miguel (Perve Galeria, Portugal) has lined up a multi-arts installation ‘Tears of Portugal’ encompassing video, photography and performance.This year’s fair has also attracted leading jewellery designer Nirav Modi who is set to present a collection of custom made designs inspired by motifs from the Mughal miniature school of art, encrusted with precious gems and priceless diamonds.Cultural events which are set to take place alongside this edition of IAF include Insert2014, an exhibition curated by Raqs Media Collective, of 20 leading international and Indian artists, and Word. Sound. Power a collaborative exhibition by Khoj International Artists’ Association and the Tate Modern.The fair also hosts a curated programme, in collaboration with public institutions, galleries and private art organisations, for visiting collectors and museums.
Darjeeling: The Chairperson of the National Commission for Women has alleged that there is no democracy in Darjeeling and that people are being suppressed by the police and district administration. She will be submitting a report of her findings and recommendations to the President of India, Union Home Minister and Chief Minister of West Bengal. She will also be summoning police top brass to her office.Following a three-day long visit of Darjeeling and Kalimpong, Rekha Sharma, Chairperson, National Commission for Women addressing media persons in Siliguri claimed that during and post 104-day bandh in Darjeeling, there has been rampant police atrocities on women. Also Read – Heavy rain hits traffic, flights”Women have been threatened, arrested, multiple cases clamped on them. Situation is grave in the Hills. There is no democracy,” alleged Sharma.She stated that she will be summoning police top brass of Darjeeling and Kalimpong. “I will summon the IG, SP Darjeeling and former SP Kalimpong who was recently transferred. They have to answer a lot of questions,” retorted Sharma.”We cannot act but we can recommend. The CM of West Bengal also is the Minister of the Home Department of West Bengal. She should visit Darjeeling and look into the matter,” stated the Chairperson.She stated that she had met 150 complainants in Darjeeling and Kalimpong. Reacting to her statements West Bengal Tourism Minister Gautam Deb stated that it is politically motivated. The Chairperson had arrived in Darjeeling on April 15. She visited Kalimpong on April 17 and returned to Delhi on Wednesday.
Kolkata: The state government is going to organise a synergy for the Micro, Small and Medium Enterprises and Textiles sector. If everything goes as planned then the synergy is going to get organised in September. According to the sources in the Micro, Small and Medium Enterprises and Textiles department, there was a detailed discussion in this connection. But final decision on the date and other aspects of the synergy will be taken in meetings to be held soon. Also Read – Heavy rain hits traffic, flightsIt has been learnt that the event is going to be held in Biswa Bangla Convention Centre. The final decision on the venue is also yet to be taken. A senior official of the department said: “It has been finalised that the synergy is going to take place in September itself and the rest of the aspects are going to be finalised soon.”There will be discussions in the synergy on different issues related to the sector and at the same time, there will be a platform for the direct discussions on different issues that will ensure sharing of knowledge. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedIt may be mentioned that the Mamata Banerjee government has taken several steps for the development of the MSME sector in the past seven years. Now, the synergy is going to help the entrepreneurs from the sector to grow their businesses.It may be mentioned that a major step was taken to ensure online pollution clearance and at the same time, the website www.silpasathi.in was also introduced for the benefit of the entrepreneurs.Moreover, the online application for fiscal incentive through www.wbmsme.gov.in was introduced in 2017. The MSME department also introduced the “Service With a Smile” (SWAS) app to extend online support to entrepreneurs. MPOST
Second-hand smoke increases the risk of stroke by about 30 percent for nonsmokers, researchers say.Even after adjusting other stroke factors such as hypertension, diabetes and heart disease, the 30 percent risk for nonsmokers remained, the team from
Darjeeling: Incessant rainfall caused a landslide at Paglajhora, 9 km from Kurseong town in between Ghayabari and Mahanadi on National Highway 55, connecting Darjeeling with the plains. The landslide has disrupted Darjeeling Himalayan Railway services, along with vehicular traffic on this stretch.This area is a landslide prone zone. The incident occurred at around 3 pm. “Till the tracks are cleared of the debris and boulders, the train from NJP to Darjeeling will run till Tindharia and the train from Darjeeling to NJP will run till Kurseong,” stated a Northern Frontier Railway. Work is on to clear the boulders and debris.