The District of Columbia is slated to take ownership of 66 acres of the former Walter Reed Army Medical Center by the end of the month, marking a critical milestone in the effort to redevelop the property into a mix of residential, office and retail space over the coming decades.A 10-day review of the transfer agreement by the D.C. Council ends July 10. If no action is taken to stop the purchase, it will be considered approved without a vote, reported the Washington Business Journal.The District will pay the Army $22.5 million and obtain the parcel through an economic development conveyance, under an agreement announced last November. The first payment of $10 million will be due at closing and will come from the District’s coffers as well as the city’s master development team. The balance will be due one year later. The deal does not include any revenue sharing.After closing, the city will lease the site to its master developers — a joint venture of Hines Interests LP, Urban Atlantic and Triden Development Group. Revenue from eight years of lease payments will offset the site’s acquisition cost.The reuse plan for the project, the Parks at Walter Reed, calls for 2,100 housing units (432 affordable), 250,000 square feet of retail anchored by a large-format supermarket, 14 acres of open space, a Hyatt hotel and conference center, space for arts organizations, an ambulatory care clinic from Howard University, and an innovation core anchored by George Washington University and the Massachusetts Institute of Technology.The Army already has handed over about 33 acres of the 110-acre campus to the State Department for the development of a foreign missions center, according to the story. Much of the remaining property will be conveyed to Children’s National Medical Center. Dan Cohen AUTHOR
(Phys.org)—A team of researchers working at Sandia National Laboratories in New Mexico has found an explanation for the variety of sounds people hear when witnessing a falling meteor—sounds that should not be heard until minutes later due to the long distances involved. In their paper published in Scientific Reports, the team describes experiments they conducted with transducer materials and what they learned by doing so. Citation: Sandia researchers offer explanation for hissing and popping noises heard from meteors (2017, February 8) retrieved 18 August 2019 from https://phys.org/news/2017-02-sandia-explanation-hissing-noises-heard.html Journal information: Scientific Reports Explore further © 2017 Phys.org 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. Meteor seen from the site of the Atacama Large Millimeter Array (ALMA). Credit: ESO/C. Malin Over the years, witnesses of falling meteors have reported hearing a wide variety of noises that appear to come from the rapidly descending fireball. While it is not surprising that meteors would emit noise as they streak through the Earth’s atmosphere, it is surprising that they would be heard during the meteor’s descent because of the distance. Meteors are generally first noticed as they begin burning many miles high in the atmosphere—and most land equally far away from witnesses. So, how could people hear emitted sounds as they are being made? That was what the team at Sandia Labs sought to answer.The team began with a theory that the noise was not actually generated by the meteor itself, but by nearby objects. They believed the bright light generated by the fireball comes in pulses and that those pulses cause a rapid rise in the temperature of the air through which they travel. The nearly instant air pressure change would result in pressure waves, which would be converted into acoustic waves when they crashed into what the team described as dielectric transducers—heat absorbing objects such as leaves, hair or even a shirt someone was wearing.To test their theory, the researchers studied photographs and video of meteors and plotted the intensity of the light generated. Then they calculated the likely acoustic waves that would result if they struck various objects. Next, they fired similar light pulses at materials to see if noises similar to those reported by meteor witnesses could be heard. They report that such sounds were, indeed, generated, suggesting that their theory was correct—the first to attempt to explain meteor noise due to light. They have called it a “photoacoustic hypothesis.” Geminids meteor shower peaks Tuesday amid full moon More information: Richard Spalding et al. Photoacoustic Sounds from Meteors, Scientific Reports (2017). DOI: 10.1038/srep41251AbstractConcurrent sound associated with very bright meteors manifests as popping, hissing, and faint rustling sounds occurring simultaneously with the arrival of light from meteors. Numerous instances have been documented with −11 to −13 brightness. These sounds cannot be attributed to direct acoustic propagation from the upper atmosphere for which travel time would be several minutes. Concurrent sounds must be associated with some form of electromagnetic energy generated by the meteor, propagated to the vicinity of the observer, and transduced into acoustic waves. Previously, energy propagated from meteors was assumed to be RF emissions. This has not been well validated experimentally. Herein we describe experimental results and numerical models in support of photoacoustic coupling as the mechanism. Recent photometric measurements of fireballs reveal strong millisecond flares and significant brightness oscillations at frequencies ≥40 Hz. Strongly modulated light at these frequencies with sufficient intensity can create concurrent sounds through radiative heating of common dielectric materials like hair, clothing, and leaves. This heating produces small pressure oscillations in the air contacting the absorbers. Calculations show that −12 brightness meteors can generate audible sound at ~25 dB SPL. The photoacoustic hypothesis provides an alternative explanation for this longstanding mystery about generation of concurrent sounds by fireballs.
Kolkata: Poet Nirendranath Chakraborty died at a private nursing home in South Kolkata on Tuesday morning. He was 94-years-old and is survived by his son and two daughters. Chakraborty was admitted to the nursing home with age related ailments in early December.Condoling his death, Chief Minister Mamata Banerjee tweeted: “Saddened at the passing of poet Nirendranath Chakraborty. It’s a great loss to us all. His contribution to Bengali literature was immense and he will always be remembered through his works. We had felicitated him with ‘Banga Bibhushan’ award in 2017. Condolences to his family.” Also Read – Rain batters Kolkata, cripples normal lifeThe mortal remains of Chakraborty were kept at Rabindra Sadan, where people from all walks of life assembled to pay their last respects to the departed soul. Banerjee went to Rabindra Sadan and placed floral wreath on the mortal remains of the poet. He was cremated at Nimtala crematorium with state honours. Mayor Firhad Hakim, state Education minister Partha Chatterjee and minister of state for Information and Cultural Affairs Indranil Sen went to the private hospital once the news of his death spread. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedChakraborty got Sahitya Akademy Award in 1974 for the book Ulanga Raja. In 2007, Calcutta University conferred on him the Doctorate of Science degree. Some of his poetry anthologies include Nil Nirjan, Prothom Nayak and Ghumiye Porar Age. Some of his famous poems are Amalkanti Roddur Hote Cheyechilo, Kolkatar Jishu and Ulanga Raja. He has also translated Tintin comics in Bengali. His notable works for adolescents are Saada Bagh, Baro Masher Chora, Pitri Purush, etc.
Kolkata: Kolkata Police have successfully managed the traffic during the Brigade rally and kept the city almost congestion free on Saturday despite unprecedented congregation of people at the United India meet.In some areas, some congestion took place while the rallies were moving towards the Brigade Parade Ground but the situation turned normal within a few hours. According to police sources, it was decided that no bus would be allowed to enter the Esplanade and the area around the Brigade Parade Ground. Since morning, traffic officials had kept a strict vigil on the buses coming with the Trinamool supporters and were strictly told to park at the designated parking areas. Only VIP and VVIP cars were allowed to enter the Brigade Parade Ground area. Also Read – 3 injured, flight, train services hit as rains lash BengalBuses coming from North Kolkata were stopped near the Central Metro Station on Chittaranjan Avenue. From there, the Trinamool supporters walked to the Brigade Parade Ground. Buses coming from Howrah were parked at Kidderpore Goat Market area and Gangasagar Mela Camp ground. Some were allowed to park at the Maidan area around the Rangers Club. Apart from the buses, huge number of people held processions from seven points across the city to reach the Brigade Parade Ground. From Shyambazar, the rally went through Chittaranjan Avenue. Another came from Sealdah using S N Banerjee Road and Esplanade. Another rally from Milan Mela availed Park Circus and Rabindra Sadan to reach the venue. A rally also originated from Hazra and it availed Ashutosh Mukherjee Road and Jawaharlal Nehru Road and the one from Park Circus moved through Park Street and Jawaharlal Nehru Road. Apart from rallies originating in Kolkata, the one from Howrah availed Brabourne Road and Esplanade to reach Brigade. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedVehicular movement was slow on some roads such as Jawaharlal Nehru Road, Dorina Crossing, S N Banerjee Road Strand Road. But necessary diversions were made as per the plan to reduce congestion. “An elaborate plan was made after a hectic workout. We had studied the traffic system and vehicular pressure which helped us to chalk out the plan. We succeeded due to the workout by the Kolkata Police team,” said a senior Kolkata Police official from Lalbazar.
Travelweek Group Jetlines shelves Waterloo routes for now; adds Abbotsford, B.C. Tags: Canada Jetlines, New Routes Share Tuesday, October 31, 2017