Different coiling configurations with rope dropped from different heights and velocities: (a) height: 1.2 cm, velocity: 26 cm/s-1; (b) height: 30 cm, velocity: 2.3 cm/s-1; (c) height: 80 cm, velocity: 100 cm/s-1. Citation: Researchers Uncover Physics of Coiling Ropes (2007, October 23) retrieved 18 August 2019 from https://phys.org/news/2007-10-uncover-physics-ropes.html Designer threads: New insight into protein fiber assembly Explore further When a mountain climber drops a rope, it often forms a series of coils on the ground. Not only thick ropes, but also sewing thread and even cooked spaghetti behave in a similar way. Recently, scientists have carried out the first controlled laboratory experiments on the peculiar phenomenon of coiling ropes, revealing the surprising dynamics behind it. Researchers Mehdi Habibi, Neil Ribe, and Daniel Bonn, together representing the Institute for Advanced Studies in Basic Sciences in Iran, the École Normale Supérieure and the Institut de Physique du Globe in Paris, and the University of Amsterdam, have published their results on the coiling of elastic ropes in a recent issue of Physical Review Letters. “With the results of this work, we — finally — are able to understand such a widespread phenomenon as rope coiling,” Bonn told PhysOrg.com. “Understanding coiling is important, for instance, in the food industry, where one needs to fill jars with visco-elastic materials such as yogurt or mayonnaise. Coiling has also been used to make pottery.”The scientists used two experimental setups to investigate the different conditions under which coiling occurs. In the first setup, they wound sewing thread onto a wheel, which was rotated by an electric motor to feed the thread down through a hole at a fixed rate (with tests from 0.3 – 200 cm/sec-1) onto a flat surface 2 – 200 cm below. In the second setup, they softened long pieces of spaghetti in water, and used a syringe or a rod to eject the noodles downward from a vertical glass tube. By comparing their laboratory measurements with the predictions of a numerical model, the group developed a phase diagram showing the different styles of coiling that occur depending on the fall height and velocity. Depending on these variables, there are three basic regimes where coiling can occur. “For the lowest fall heights and velocities, the coil frequency and radius are dictated by the geometry: the coiling frequency, for instance follows simply from the fall height and rope velocity,” Bonn explained. “For intermediate heights and velocities, there is a balance between the gravity force and the rope’s elasticity that uniquely determines the frequency and radius of coiling. For very high velocities and heights, it’s mainly the inertia of the rope that dictates its behavior, but the elasticity of the rope remains important: this is the inertial regime.”Habibi, Ribe and Bonn found that the inertial regime in particular is surprisingly complex. First, they observed that a thin thread fed at very high velocities becomes unstable to form a “figure of eight” pattern that persists for the length of the thread. Second, they found that coiling in the inertial regime can occur with different frequencies for a given feed rate and fall height. The different frequencies correspond to resonant oscillations of the nearly vertical upper part of the rope, which can vibrate either as a weak “string” or as a stiff “shaft” depending on the feed rate and the fall height. These oscillations are excited when their natural frequencies happen to match the basic “inertial regime” frequency dictated by the coiled part of the rope just above the ground. The scientists noted that other examples of coiling “elastic rods” include phenomena such as the kinking of telephone cables on the ocean floor, the coiled tendrils of climbing plants exhibiting handedness reversal, and the supercoiling of DNA strands. The coiling of liquid ropes, such as a thread of honey falling onto toast, has also received recent attention, and shares some similarities with the coiling of elastic ropes. Citation: Habibi, M., Ribe, N. M., and Bonn, Daniel. “Coiling of Elastic Ropes.” Physical Review Letters 99, 154302 (2007).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.
© 2013 Phys.org IPhone to get larger screen: A report to take with a grain of salt? Credit: Diginfo.tv As for text entry, the carrier is promoting the keyboard feature as easy to use and ideal for users keen on action on social networking sites, along with those who like the idea of a having a new sort of mini-tablet. Turned on its side, the bottom screen can behave as the keyboard.Outside Japan, bloggers are already posing questions about what a two-screen form factor could mean with regard to predictions that the “phablet” form factor is poised for takeoff. The nuance is in bigger smartphones biting into established lines of smaller tablets. Estimates so far point to 2018 as the year phablets will show their strength in accounting for 25 percent of smartphone sales. At the same time, tech watchers have noted that power issues could keep two-screen form factors from marketplace takeoff right away, but the new Medias W is worth watching nonetheless. Explore further (Phys.org)—Springtime will spring a new two-screen smartphone in Japan from NTT Do Como, and there is a lot of talk in the air already about what the new Medias WN-05E will spell for a rising tide of form factors now dubbed “phablets.” The two-screens in this phone are hinged back to back and provide the user with the opportunity to use the screens independently of each other—playing a game on one screen, for example, while checking out a map on the other screen—or having the two screens behave as one bigger screen. The smartphone is slated for an April release; pricing and a time frame to launch the phone outside Japan are not yet known. Citation: Medias W N-05E in wings as two-screen smartphone (2013, January 23) retrieved 18 August 2019 from https://phys.org/news/2013-01-medias-n-05e-wings-two-screen-smartphone.html The two-screen Medias W, with an 8.1MP camera, is an Android 4.1 smartphone; there are two 960 x 540 4.3-inch screens displays, and it has a 1.5GHz Qualcomm Snapdragon MSM8960 processor. The LCD screens are on the outside of the clamshell rather than the inside. The clamshell-shaped device, when unhinged, has screens that can operate side to side if you wish to multitask, or can be combined into a larger screen. DigInfo TV has carried a video showing the phone and its functions. A map is shown on both screens; a user could check out a map on the bigger screen, putting up with the line seam in the middle, but would be able to pinch and zoom across the pair of screens. More information: www.nttdocomo.com/pr/2013/001624.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.
Citation: Ultraviolet spectroscopic evolution of a tidal disruption event investigated by astronomers (2017, April 19) retrieved 18 August 2019 from https://phys.org/news/2017-04-ultraviolet-spectroscopic-evolution-tidal-disruption.html More information: The Ultraviolet Spectroscopic Evolution of the Low-Luminosity Tidal Disruption Event iPTF16fnl, arXiv:1704.02321 [astro-ph.HE] arxiv.org/abs/1704.02321AbstractWe present the ultraviolet (UV) spectroscopic evolution of a tidal disruption event (TDE) for the first time. After the discovery of the nearby TDE iPTF16fnl, we obtained a series of observations with the Space Telescope Imaging Spectrograph (STIS) onboard the Hubble Space Telescope (HST). The dominant emission features closely resemble those seen in the UV spectra of the TDE ASASSN-14li and are also similar to those of N-rich quasars. However, there is significant evolution in the shape and central wavelength of the line profiles over the course of our observations, such that at early times the lines are broad and redshifted, while at later times the lines are significantly narrower and peak near the wavelengths of their corresponding atomic transitions. Like ASASSN-14li, but unlike N-rich quasars, iPTF16fnl shows neither MgIIλ2798AA nor CIII]λ1909AA emission features. We also present optical photometry and spectroscopy, which suggest that the complex HeII profiles observed in the optical spectra of many TDEs are in part due to the presence of NIII and CIII Wolf-Rayet features, which can potentially serve as probes of the far-UV when space-based observations are not possible. Finally, we use Swift XRT and UVOT observations to place strong limits on the X-ray emission and determine the characteristic temperature, radius, and luminosity of the emitting material. We find that iPTF16fnl is subluminous and evolves more rapidly than other optically discovered TDEs. TDE occurs when a star passes close enough to a supermassive black hole and is pulled apart by the black hole’s tidal forces, causing the process of disruption. Such tidally disrupted stellar debris then rains down on the black hole and radiation emerges from the innermost region of accreting debris, which indicates the presence of a TDE. TDEs serve as invaluable probes of strong gravity and accretion physics, providing answers about the formation and evolution of supermassive black holes. While most such events are discovered in optical transient surveys, ultraviolet observations provide an opportunity to learn much more about the kinematics and ionization structure of tidally disrupted stellar debris.iPTF16fnl was discovered on Aug. 26, 2016 as a transient consistent with the center of the galaxy Mrk 0950. This transient was later classified as a rapidly evolving, low-luminosity TDE, located about 220 million light years away. It is the nearest TDE found so far and its black hole mass is estimated to be not greater than 5.5 million solar masses. Due to the proximity of iPTF16fnl to Earth, Brown and his colleagues decided to initiate a follow-up observational campaign in order to study this event in detail. These observations were conducted using the Hubble Space Telescope’s (HST) Space Telescope Imaging Spectrograph (STIS) and the Ultraviolet/Optical Telescope (UVOT) onboard NASA’s Swift spacecraft. The researchers also employed several ground-based observatories in order to perform photometric and spectroscopic monitoring of this event. All these instruments allowed the team to spectroscopically observe the temporal evolution of a TDE in ultraviolet light for the first time ever.”We presented for the first time the UV spectroscopic evolution of a TDE using data from HST/STIS,” Brown’s team wrote in a research paper available on arXiv.org.The results show that shape and velocity offset of the broad ultraviolet emission in iPTF16fnl and absorption features evolve with time.”There is significant evolution in the shape and central wavelength of the line profiles over the course of our observations, such that at early times, the lines are broad and redshifted, while at later times, the lines are significantly narrower and peak near the wavelengths of their corresponding atomic transitions,” the paper reads.The researchers found that ultraviolet spectra of iPTF16fnl closely resemble those of ASASSN-14li (other nearby TDE) and nitrogen-rich quasars. When it comes to optical spectra of iPTF16fnl, the findings indicate that they resemble those of several other optically discovered TDEs.”The dominant emission features closely resemble those seen in the UV spectra of the TDE ASASSN-14li and are also similar to those of N-rich quasars,” the authors wrote.All the data obtained by various space and ground-based telescopes allowed the scientists to draw conclusion that iPTF16fnl is subluminous and evolves more rapidly than other optically detected TDEs. Explore further (Phys.org)—An international team of astronomers led by Jonathan S. Brown of the Ohio State University in Columbus, Ohio, has studied the ultraviolet spectroscopic evolution of a nearby low-luminosity tidal disruption event (TDE) known as iPTF16fnl. The results of this study, published Apr. 7 on arXiv.org., offer new clues on the nature of this TDE. © 2017 Phys.org Two new tidal disruption events discovered The UV evolution of iPTF16fnl as revealed by HST/STIS spectra and Swift photometry. The spectra have been smoothed with a 5 pixel boxcar and scaled by a constant factor to best match the Swift photometry for ease of comparison. The dashed lines show our blackbody fits to the host subtracted Swift fluxes. Prominent atomic transitions are marked with vertical dotted lines. The thin gray line shows our estimate of the UV spectrum of the host based on the SED model. Credit: Brown et al., 2017. 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.
India’s first multidisciplinary arts event, the Serendipity Arts Festival 2018 is organising Football – A beautiful life, a 6-day film programme from 22 – 27 November, at Children’s Park, Goa. This is an official collateral event of the 49th International Film Festival of India (IFFI).Curated by Jan Tilman Schwab, Football – A beautiful life will showcase a range of exceptional features films and documentaries from around the world in which human and social stories are told through football. Attendance at all sessions is free until full capacity is reached and after each film, there will be a short discussion about the film. Proving football truly is the world’s game, the festival will feature films in more than 6 different languages, representing a diverse range of football stories from Spain, Lebanon, Brazil, Germany, Iceland and India. Also Read – Add new books to your shelfThe film programme will celebrate Football, a game deeply embedded in the history and culture of Goa, which resonates with Goans better than any other sport. The films demonstrate the unifying power of football that brings individuals together and creates a sense of community. The screenings cherish the beautiful game and enhance the love for this beautiful life. Spotlighting Goa’s most loved sport through film, the project extends the Festival’s interdisciplinary approach and inclusive community programming that is continually sensitive to the cultural nuances of its host city. Also Read – Over 2 hours screen time daily will make your kids impulsiveJan Tilman Schwab said, “Football – A Beautiful Life is a gift from the Serendipity Arts Festival to the people of Panjim. I am honoured to be the lucky person invited to curate this unique and free public programme. Football and Film have a lot in common: both are team efforts, both depend basically on motion, both are non-verbal languages that can be understood everywhere in the world. I wanted to present films that have a high educational potential, that viewers can learn something from, whether this be from the film’s content and story, or its form and structure. The films chosen represent almost all continents, and include short and feature films, documentaries, fiction, and comedies that each tell stories of triumph and setbacks. The audience will get opportunities to laugh and weep.” The Football Film screening programme is part of a series of multidisciplinary arts activations that will energise Goa in the lead up to Serendipity Arts Festival 2018. Initiatives like these are an integral part of the Foundation’s mission of making the arts accessible and developing arts audiences both in numbers and in diversity. In its previous two editions, the Serendipity Arts Festival attracted more than 400,000 visitors creating significant public impact and contributing to the cultural regeneration of Panaji. This year’s programming continues to honour the culture and the arts of the Festival’s host city redefining heritage sites and architectural icons through creative and community-focused projects. This year the Festival will take place across 10 venues in Goa and involve over 1300 artists, transforming Panaji into a vibrant cultural space with multiple exhibitions, performances and immersive arts experiences. Highlights of this year’s event include theatre performances designed for children, large-scale public installations in the visual arts and photography, a variety of outdoor and evening music performances, culinary workshops and tastings, as well as a range of specially commissioned projects across disciplines which will be exclusive to Serendipity Arts Festival 2018. Projects will unite artforms from different parts of the country, encouraging cross-cultural exchange.
Kolkata: Metro Railway conducted an anti-littering drive last month in its stations last month which revealed that the number of such cases has gone down a lot.According to Metro Railway authorities, since the past few years special anti-littering driver were being carried out to prevent such nuisance practices by the passengers. During May 2018, the highest number such cases was recorded. Metro Railway had earned Rs 1.47 lakh from 576 cases at that time. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataLast month, Metro Railway authorities found that the number of such cases has gone down a lot. From May 1 to May 31 only as many as 165 such cases were detected by the authorities. Fines worth Rs 42,000 have been collected. Maximum number of cases, which is 52 has been recorded in Dum Dum metro station. Metro authorities informed that adequate number of bio-degradable and non-biodegradable dustbins have been installed at all the stations to prevent littering at the platforms and the metro tracks. In spite such efforts, a section of commuters have still been littering the stations premises, trains and track beds. To prevent such nuisance activities, drives will be conducted in future as well.
Kolkata: Police arrested the husband of the woman whose mutilated body parts were recovered by the Howrah Police on July 18.The woman has been identified as Sony Rajak, a resident of Shibpur. Her husband, Upendra Rajak was arrested on early Saturday morning. Following his statement, two hired butchers, Dilwar Khan and Shakil Khan, were also arrested from Bhadreshwar. Upendra told the police that he had killed his wife for allegedly having an extra-marital relationship. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataDeciphering the CCTV footage has helped the police to solve one of the gruesome murders in recent times within 48 hours after the mutilated body parts were recovered on July 18. The police found the severed head of an unidentified woman along with several body parts at Jetia Ghat in Howrah on the morning of July 18. The photograph of the head and the body parts were sent to all the police stations in Howrah. On July 18 evening, Upendra filed a missing complaint of his wife with the Shibpur police station. He alleged that his wife might have fled with her boyfriend. Also Read – Lightning kills 8, injures 16 in stateThe police began investigating and while deciphering the CCTV footage, they found two men taking out two huge bags from a taxi at Ballykhal. Then they took a cycle rickshaw and drove towards Jetia Ghat. The bags which the police had seized from Jetia Ghat served as the main clue in solving the case. The colour of the bag matched with the CCTV footage. They picked up Upendra from his residence and showed him the bags. Though he denied initially, he finally broke down during the interrogation. Upendra had appointed two butchers — Dilwar and Shakil. Dilwar bought sedatives from a shop in Kolkata and Upendra mixed it with food and served it to her on the night of July 17. When she fell asleep, she was strangulated to death. Her two children were taken to another room and the door was locked from outside. The butchers then cut her up into pieces and put the parts in two boxes. They hired a taxi and went to Ballykhal. From Ballykhal they took a cycle rickshaw and reached Jetia Ghat. They took out the body parts and threw them into the Hooghly. It was around 3.30 am and they left the Ghat quietly without being noticed. Upendra told the police that he had paid Rs 30,000 to the Khans. Divers are looking for the severed limbs which are yet to be traced.
A young girl from Bareilly, who would accompany her father to Khanqah E Aalia Niazia (Dargah in Bareilly) to hear Sufi music, had no idea that music would become her life one day. “Music comes before anything for me”, she feels.Sharing her childhood memories, the singer further says, “At dargah, I would find myself lost in the musical trance. back then, I could hardly understand the technicalities or depth of Sufi music (or music in general), but nevertheless, it left an everlasting impression on my soul.” Also Read – Add new books to your shelfBefore finding tranquility in Sufi music, Kavita explored various genres like Ghazals, Qawwali and Folk music. But there was always a void…a feeling of incompleteness that haunted her, until she got an opportunity to perform in ‘Jahan-e-Khusrau’ (annual concert organised by Muzaffar Ali). “There were Sufi singers from across the world participating in that event, and that’s where I found the missing piece of my life. The charm of Sufi music took over me and I found serenity. Thereon, I started reading about Sufi saints and their writings,” she says, adding,”There could be nothing better than singing for divine power. Jab Aap Khuda ki Shaan me Gaate ho, to Phir Kuch Aur Accha Nahi Lagta” she adds. Also Read – Over 2 hours screen time daily will make your kids impulsiveRecently, Kavita was in the Capital for a musical evening ‘Anandotsav – A celebration of life’. Held at India Habitat Centre, the event was organised on the birth anniversary of her late husband K K Seth, whom she considers her friend, mentor, support system and guiding force. “Every year I try my best to do something in his beloved memory and acknowledge his contribution to my success. Whatever I am today is because of him.” A successful and world acclaimed singer today, Kavita went through a long and difficult journey. “Like any other small town girl, I faced discouragement from my family when they came to know about my aspirations. They told me ‘Shaadi ho jaaye, uske baad agar husband ko tumse gawaana ho toh gaana, We can’t take you to places. Guarantee nahi hai ki success milegi’ – they said. Soon after my graduation, they started looking for a suitable match and all I prayed for was to get married to a person who would support me and my dreams. And it was my good fortune that I found Mr Seth.” “From the day we met, to the day he died, he lived my dreams. The word ‘Impossible’ was not in his dictionary, and that’s the reason I am so positive about everything. He changed me as a person. You won’t believe but within 10 days of his death, I was doing shows. I didn’t cancel a single concert because that’s what he taught me – to be loyal towards work, to accept the changes, and move on with grace,” mentions the singer who has sung chartbusters including ‘Iktara’, and ‘Tum Hi Ho Bandhu’. The time after her husband’s death was the most challenging phase of Kavita’s life, and being a part of the entertainment industry further added to the difficulties. “Working in this industry is nothing less than working like a soldier for BSF or CRPF. You have to hide your pain, look presentable, and be available all the time. There is no weekend for us.” However, despite all the drawbacks, the best thing about this industry is that people are very passionate about their work and that’s the reason why working round the clock is not a headache for them, she feels. In 2014, Seth got married again to a man who was equally supportive. “My husband helps in organising my events, my children are supportive and I have music in my life. What more can I ask for,” she concludes.