Citation: Freelance site using software to recruit and pay workers (2010, May 12) retrieved 18 August 2019 from https://phys.org/news/2010-05-freelance-site-software-workers.html Explore further (PhysOrg.com) — Freelancer.com, a freelance site based in Sydney, Australia, has come up with the idea of using software to recruit and pay professionals to carry out work. The site enables software developers to write programs to post job adverts, select from those bidding on the jobs, and even pay them, without any human input. API Flow Overview © 2010 PhysOrg.com
Explore further (PhysOrg.com) — The many ways in which water differs from other molecules is both a scientific curiosity and an important factor in shaping the Earth. Among water’s unique properties are that it expands when it freezes, it boils and freezes at higher temperatures than expected for a compound with its molecular structure, and it has the ability to absorb large amounts of heat without getting hot. In a recent study, scientists have investigated another unique phenomenon of water called regelation, which occurs when frozen water – or ice – melts under high pressures, even if the temperature is below freezing. Once the pressure is lifted, the water refreezes. The scientists, Teemu Hynninen from the Tampere University of Technology and the Aalto University School of Science and Technology in Finland, as well as coauthors from Finland, Canada, and the US, have performed simulations of the pressure-induced melting of ice by cutting a block of ice with a nanowire. The experiment is similar to a classic experiment performed over a century ago in which scientists demonstrated that a thin, weighted wire could slowly pass through an ice block due to the pressure it exerts on the ice. In the new study, the scientists simulated a nanowire, whose diameter was on the scale of the water molecules, to investigate the molecular-level mechanisms responsible for regelation.“We decided to study the wire-cutting experiment because it has historical signifigance, it is conceptually simple, and it hadn’t been studied on the microscopic scale,” Hynninen told PhysOrg.com. “In this case, we have a wire moving through ice (instead of sliding on it like in normal friction), and the motion is governed by complicated interplay between the wire and the liquid and solid phases of water.” In the simulations, the nanowire is depicted as a string of beads that interact with the H2O molecules. When these beads exert a pressure on the H2O molecules, they break the hydrogen bonds between the oxygen atom of one molecule and the hydrogen atom of another molecule. This breaks the ice lattice structure and transforms the solid ice into liquid water, allowing the nanowire to move through the water, even though the temperature is below freezing. As the scientists explain, the critical point at which the nanowire melts the ice can be thought of as a depinning transition, which generally refers to the yield point of a solid under stress. The simulations showed that this critical point depends on the type of wire used. The scientists compared two types of nanowires – hydrophilic, i.e., a wire whose surface attracts water, and hydrophobic, i.e., a wire whose surface repels water – and found that the wires moved differently through the ice after the depinning transition. Copyright 2010 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. The difference is due to the nanowires’ different structural properties, which causes them to interact differently with the surrounding water molecules. The hydrophilic nanowire exhibits a continuous transition at depinning, where the water can easily flow around it, allowing for smooth movement through the ice block. The hydrophobic wire, on the other hand, exhibits a discontinuous transition, where the water builds up thickly on one side of the nanowire. This wire can only move once the water layer builds up high enough so that it reaches the top of the wire, at which point it flows down the other side into a small void, allowing the nanowire to cut through the ice. As the scientists explain, this behavior is somewhat counterintuitive, since a hydrophobic wire might be expected to move more quickly through water than a hydrophilic one due to the latter’s closer water contact and increased friction. However, in this case, the hydrophobic wire’s resistance to water causes it to be partly obstructed by solid ice, giving it more resistance to movement than the hydrophilic wire.“The physically most interesting result we found is that there is a clear difference between the hydrophobic and hydrophilic wires in the way they depin, i.e., how they start moving as the driving force increases,” Hynninen said. “Although the nanowire we use here is a very simple object, our work shows that small structures in contact with water and ice may exhibit unexpected, complicated behavior.” This qualitative understanding and the additional detail provided by the simulations demonstrates how the pressure-induced melting of ice depends on the wetting properties of the object – in this case, the nanowire – applying the pressure. The molecular-scale mechanisms that explain this unique property of water could allow scientists to better understand how the pressure-induced melting and freezing of water has helped shape the Earth. For example, the phenomenon of regelation acts in systems such as glaciers, allowing pressurized ice sheets to flow around obstacles.“This study is basic research, not aimed to solve any particular problem,” Hynninen said. “Having said that, the work is part of a bigger project on the friction of ice at the nanoscale, and there the applications are more obvious. The slipperiness of ice and wet surfaces are significant issues in, e.g., transportation, and better understanding of these phenomena at the microscopic level could help design coatings or microstructures with desired frictional properties for tires, shoes, sports equipment, etc.” Researchers study how ice melts in contact with soil More information: Teemu Hynninen, et al. “Cutting Ice: Nanowire Regelation.” Physical Review Letters 105, 086102 (2010). DOI:10.1103/PhysRevLett.105.086102 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: Scientists investigate how ice melts below freezing due to nanowire’s pressure (2010, September 2) retrieved 18 August 2019 from https://phys.org/news/2010-09-scientists-ice-due-nanowire-pressure.html This figure shows how hydrophilic and hydrophobic nanowires move differently through ice: the liquid easily flows around the hydrophilic wire, but builds up on one side of the hydrophobic wire. Image credit: Teemu Hynninen, et al. ©2010 The American Physical Society.
Researchers produce first Iraqi-to-English speech-to-speech translation app “No network required,” reads the promotion. “Results appear immediately on your video screen when you need it, anywhere in the world.”Word Lens uses text recognition to work out what the word or phrase is, and automatic-translation software translates it into the new language. The translation is then pasted over the original location. “An optical character recognition engine works with the in-built real time translator to translate foreign phrases for you. The converted text is then displayed on the screen of the smart phone.” © 2012 Phys.org More information: play.google.com/store/apps/det … c3VhbC53b3JkbGVucyJd (Phys.org) — Tuna with hot sauce. Beach closed. Please use caution. Apple users of iOS devices, drawing envy with their cooler than cool apps, have since 2010 enjoyed Word Lens, an application that instantly provides a foreign language translation of a menu or road sign just by the user hovering the device’s camera over the foreign language content in realtime. Now Word Lens is offering its translation app for Android too. The Android app will do translations between English and Spanish, Italian, and French using just the video camera. The nice feature of the app is that network connectivity is not required. Citation: Word Lens – augmented reality translation app – jumps platforms, is now on Android (2012, July 9) retrieved 18 August 2019 from https://phys.org/news/2012-07-word-lens-augmented-reality.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. Otavio Good and John DeWeese from Quest Visual are the two developers behind Word Lens. According to Good, Word Lens tries to find out what the letters are and then looks in the dictionary. Then it draws the words back on the screen in translation. The Android app is offering for purchase translations between English and Spanish, French, and Italian. The introductory price is $4.99 per language.Those testing out Word Lens for the Android platform think it has a way to go. One site said that their brief tests of Word Lens for Android showed it worked well except for rapid flickering of words going back and forth in the translation process. Others described the Android version as having a quirky interface and being shaky and bumpy. Also, said one critique, the app does not work effortlessly in that you need to keep the hand steady and scroll over sentences patiently. Also, phrases have strangled English language word placements, such as “Tongue Bolivian” or “sauce spicy of anchovies” but as a language support tool for visitors to foreign countries it is largely considered as useful. The developers themselves caution that the app will best work with “clearly printed text“ and they note that it does not recognize handwriting or stylized fonts. Good acknowledges weaknesses and says he would be the first to say that the app is not perfect, “but perfect was not the goal,” he added. What is useful, he said, is that “you can get the general meaning.” (Whether it is a spicy sauce or a sauce spicy, you know what is coming.) The app gets good marks elsewhere for speed and useful accuracy. Good says that future plans include introducing more languages. He is also considering a reader for the blind, which would read out loud the words that the app sees on signs. Explore further
True-color image of layers of haze in Titan’s atmosphere. Credit: NASA Experiments show Titan lakes may fizz with nitrogen Radar images from Cassini showed a strange island-like feature in one of Titan’s hydrocarbon seas that appeared to change over time (series of images at left). Credits: NASA/JPL-Caltech/ASI/Cornell © 2017 Phys.org Prior research has suggested that the seas that exist on Titan are likely made of methane at or near the surface and ethane at greater depth and that the moon’s atmosphere is likely mostly nitrogen. Also, prior research that involved studying images sent back by the Cassini space probe showed islands in some of the moon’s seas appearing and disappearing over time. Study of such islands showed that they were not due to changes in sea levels, which led some to theorize that they were maybe nothing more than areas where bubbles were bursting as they percolated up from below. In this new effort, the researchers built computer models to find out if bubbles really could be the cause of the mysterious islands.To create their computer models, the researchers input data regarding Titan’s makeup and also used data supplied by oil and gas companies that describe the way underground fluids behave under great pressure here on Earth.The researchers report that their models showed that the islands could, indeed, be bubble streams, and offer an explanation of how it could happen. They suggest factors on Titan such as tides, wind or even changes in atmospheric temperatures could cause nitrogen from the atmosphere to mix with methane from the surface, which would then be pushed down into pools of ethane—the difference in pressure at varying depths would force the components to separate, causing the formation of nitrogen gas bubbles, which would naturally rise back up to the surface. They note also that such bubbles would be very reflective, which would explain why they would be picked up by Cassini’s sensors.
Quasars, or quasi-stellar objects (QSOs) are extremely luminous active galactic nuclei (AGN) containing supermassive cetral black holes with accretion disks. Their redshifts are measured from the strong spectral lines that dominate their visible and ultraviolet spectra. All observed quasar spectra have redshifts between 0.056 and 7.54.Astronomers are especially interested in finding new high-redshift quasars as they are the most luminous and most distant compact objects in the observable universe. Spectra of such QSOs can be used to estimate the mass of supermassive black holes that constrain the evolution and formation models of quasars. Therefore, high-redshift quasars could serve as a powerful tool to probe the early universe.Recently, a team of astronomers led by Szymon Kozłowski of Warsaw University Observatory in Poland has conducted a search for high-redshift quasars in Magellanic Clouds. They analyzed the images from OGLE-IV survey and mid-infrared data collected by NASA’s Wide-field Infrared Survey Explorer (WISE), which resulted in the detection of 33 quasar candidates.From these candidates, the researchers spectroscopically observed the two most variable ones. Follow-up spectroscopic observations confirmed that these two objects are indeed high-redshift QSOs.”We report the discovery of two high-z quasars, OGLE J015531−752807 at a redshift z = 5.09 and OGLE J005907−645016 at a redshift of z = 4.98,” the astronomers wrote in the paper.OGLE J015531−752807 has an absolute magnitude in the near-infrared I-band of –27.82 mag, and is the most distant and variable object identified in the OGLE survey to date. When it comes to OGLE J005907−645016, it has an absolute magnitude in the I-band of –28.73 mag. According to the study, the two newly found QSOs have variability amplitude of around 0.4 mag at the rest-frame wavelength of about 1300̊A. This is much larger than in other quasars (less than 0.15 mag) at the same rest-frame wavelength but lower redshifts (between 2.0 and 4.0).The researchers noted that these values may indicate that an increased variability amplitude exists in the population of high-redshift quasars. However, they added that a larger sample of high-redshift QSOs with a at least decade long light curves is needed to verify this assumption. The list of such objects can be expanded by studying other quasar candidates reported in the paper, or by future observations using the Large Synoptic Survey Telescope (LSST) in Chile, which is expected to become operational in the coming years.”This variability issue can be resolved by studying variability of a larger AGN sample at z ≈ 5. This is entirely possible now, because we also provide a list of 31 AGN candidates at z ≈ 5, where all of them have nearly a decade long light curves from OGLE. A sample of high-z AGN with a decade-long light curves will be also increased by the Large Synoptic Survey Telescope, providing light curves for sources 3–4 mag fainter than OGLE,” the astronomers concluded. More information: Szymon Kozłowski et al. Discovery of two quasars at z=5 from the OGLE Survey. arXiv:1810.08622 [astro-ph.GA]. arxiv.org/abs/1810.08622 Astronomers report the finding of two new high-redshift quasars using imagery from the Optical Gravitational Lensing Experiment (OGLE). The newly found quasars, designated OGLE J015531−752807 and OGLE J005907−645016, have redshifts of 5.09 and 4.98 respectively. The discovery is detailed in a paper published October 19 on arXiv.org. © 2018 Science X Network Two bright high-redshift quasars discovered The original OGLE-IV I-band light curves of OGLE J015531−752807 (top; gray points) and OGLE J005907−645016 (bottom; gray). Credit: Kozłowski et al., 2018. Explore further Citation: Two high-redshift quasars discovered using OGLE (2018, October 30) retrieved 18 August 2019 from https://phys.org/news/2018-10-high-redshift-quasars-ogle.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.
Explore further Astronomers have conducted a study of unusually bright single pulses (BSPs) from the millisecond pulsar PSR B1744−24A. The new research, which determined properties of these pulses, could contribute to understanding the nature of BSPs. The study is presented in a paper published November 5 on arXiv.org. Mode changing and giant pulses found in a millisecond pulsar An example of a bright single pulse, integrated between 1,100–1,900 MHz, together with the average profile obtained by summing 5,000 spin periods around the bright pulse. The intensity of the average profile has been multiplied by a factor of 10. Credit: Bilous et al., 2018. Citation: Astronomers investigate unusually bright single pulses from a millisecond pulsar (2018, November 26) retrieved 18 August 2019 from https://phys.org/news/2018-11-astronomers-unusually-bright-pulses-millisecond.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. Located some 19,200 light years away in globular cluster Terzan 5, PSR B1744−24A, or B1744−24A for short (also known as Ter5A), is an eclipsing millisecond pulsar in an ablating binary system. The pulsar has a spin period of 11.56 milliseconds and has a relatively low-mass companion around 10 times less massive than our sun.Observations of PSR B1744−24A have shown that it has highly variable radio eclipses and unusually bright pulses, with intensities up to 40 times the average pulse intensity, and pulse widths similar to that of the average pulse profile. The BSPs from PSR B1744−24A were detected in 2009 by 100-m Robert C. Byrd Green Bank Telescope (GBT). These pulses were observed in the vicinity of the eclipses – in time near eclipse ingress and egress.Unusually bright single pulses are an unexplained phenomenon. Researchers debate whether BSPs are a new, distinct population of pulses, or the result of a propagation effect. The properties of such pulses, like these detected in PSR B1744−24A, make them difficult to classify as a separate emission mode or a giant pulse.In order to learn more about unusually bright single pulses, a trio of researchers led by Anna Bilous of the University of Amsterdam in the Netherlands, has re-investigated observational data of PSR B1744−24A collected by GBT. They have analyzed eight multi-orbit observations of this pulsar to better determine the properties of its pulses.”We present a study of unusually bright single pulses (BSPs) from a millisecond pulsar in an ablating binary system, B1744−24A, based on several multi-orbit observations with the Green Bank Telescope,” the astronomers wrote in the paper.In general, the scientists found that the properties of BSPs in PSR B1744−24A are difficult to explain by scintillation in the interstellar medium, by a separate emission mode, or by conventional giant pulses. These unusual properties are: clustering close to eclipses, unchanging average pulsed intensity or profile shape during BSP outbursts, widths similar to the width of the average profile, intensities up to 40 times the average pulse intensity, and correlated structures in dynamic spectra spanning several pulses.According to the study, BSPs from PSR B1744−24A are similar to strong pulses observed from the so-called Black Widow binary pulsar (or PSR B1957+20). Given that the pulses from the Black Widow pulsar were found to be strong lensing by the intrabinary material, the authors of the paper suggest the same explanation in the case of PSR B1744−24A.”We argue that the strong lensing likely occurs in B1744−24A as well,” the researchers noted.Assuming that strong lensing can explain, at least qualitatively the unusual properties of BSPs from PSR B1744−24A, the researchers calculated that the proposed lens could be even as small as five to 280 kilometers, and residing as close as 0.06 to 160 orbital separations from the pulsar.The astronomers added that further observations of BSPs from pulsars could be helpful in examining the physical conditions in the intra-binary plasma and providing insights into the emission region within the pulsar magnetosphere. © 2018 Science X Network More information: Anna Bilous et al. Unusually bright single pulses from B1744-24A binary: a case of strong lensing? arXiv:1811.05766 [astro-ph.HE]. arxiv.org/abs/1811.05766
Kolkata: The Bureau of Indian Standards (BIS) will launch a special drive to create awareness among the consumers to purchase hallmarked jewellery on the occasion of Akshay Tritiya. A meeting was held between senior BIS officials and some jewellers at the Eastern Regional Office on Tuesday afternoon. BIS officials Vishnu Gupta, NK Kansara, KK Paul and Kunal Kumar spoke to jewelers Samar De and Subir Sen and others on the issue. The Government of India started BIS Hallmarking Scheme in the year 2000 to protect the consumers against becoming a victim to inferior quality gold or silver. This scheme is presently voluntary but according to the BIS officials, they have appealed for it to become mandatory. BIS official, Vishnu Gupta, spoke about the precautions that a customer must take into account whilst purchasing hallmark jewellery. The purchased jewellery must have all the 4 symbols of hallmark, which are the BIS Standard Mark, Purity in carat, Assay Centre’s identification mark and jeweller’s identification mark. Customer should also be aware that the concerned jewellery shop must have the sign of hallmarked licence on their board prescribed by the Bureau of Indian Standards. The cash memo provided to them must be checked and a proper invoice should be kept for further verifications, if the hallmarked jewellery is under suspicion. The hallmarking charges per article for gold are Rs 35 and Rs 25 for silver.The officials said 21,641 hallmark jewellery license holders are present in India and BIS hopes that this number will increase due to this awareness drive.
Adarsh Shastri, an Aam Aadmi Party MLA from Dwarka is now the Parliamentary Secretary (Information Technology) in Arvind Kejriwal’s team in Delhi. The former Sales Head of Apple India, Shastri has been entrusted to bring in Information Technology in various departments of Delhi government and convert the national Capital into a “Smart City”. He is also looking after the wi-fi project, one of the flagship
Veteran actor Rishi Kapoor ushered in his birthday with son Ranbir and wife Neetu. The actor, who turned 62 on Friday, posted a picture along with the Bombay Velvet star and Neetu.“This afternoon at the Le Petit Maison. Thank you Ranbir for coming early,” Rishi posted on twitter alongside the picture in which the trio are seen posing in a restaurant.Neetu took to Instagram and shared the same picture with the caption, “Rans joins in for his Dad s birthday celebrations!!! Bless him. 4rth sep.”