Wave acceleration of electrons in the Van Allen radiation belts

first_imgThe Van Allen radiation belts are two regions encircling the Earth in which energetic charged particles are trapped inside the Earth’s magnetic field. Their properties vary according to solar activity and they represent a hazard to satellites and humans in space. An important challenge has been to explain how the charged particles within these belts are accelerated to very high energies of several million electron volts. Here we show, on the basis of the analysis of a rare event where the outer radiation belt was depleted and then re-formed closer to the Earth, that the long established theory of acceleration by radial diffusion is inadequate; the electrons are accelerated more effectively by electromagnetic waves at frequencies of a few kilohertz. Wave acceleration can increase the electron flux by more than three orders of magnitude over the observed timescale of one to two days, more than sufficient to explain the new radiation belt. Wave acceleration could also be important for Jupiter, Saturn and other astrophysical objects with magnetic fields.last_img read more

Are millennials financially doomed?

first_img 32SHARESShareShareSharePrintMailGooglePinterestDiggRedditStumbleuponDeliciousBufferTumblr Millennials have more debt and less income than Gen X or baby boomers on average. But those aren’t the only financial constraints some face.New data show 1 in 5 supported an aging parent over the last year, spending an average of $18,250 a year on medical bills and other expenses — more than any other generation, according to TD Ameritrade’s recent 2015 Financial Support survey.That single expense puts a serious strain on their ability to pay off student loans and save for retirement. (Consequently, baby boomer parents have also delayed their retirement plans to help their children financially)“It’s a lot harder to keep your head above water if you have to support family members and still try to tackle your debt,” said Matt Sadowsky, TD Ameritrade’s director of retirement and annuities. continue reading »last_img read more

Van Gaal nears decision on players

first_imgLouis van Gaal will sit down with his players after their tour and tell them whether they have a future at Manchester United. Van Gaal and his 25-man squad fly back to Manchester in the early hours of Tuesday morning following their final game of the US tour against Liverpool. Van Gaal has racked up morale-boosting wins over the Los Angeles Galaxy, Roma, Inter Milan and Real Madrid, but he is still unhappy with certain aspects of his squad. Van Gaal thinks Van Persie is unlikely to be fit to face Swansea on August 16, but the other two could be in contention for United’s Barclays Premier League opener, depending on how they react to training. “I have to look at Robin van Persie if he is coming back or not,” said Van Gaal, who coached the striker at the World Cup. “But if you have three weeks holiday and only four days training before the Valencia friendly (on August 12) you are not fit enough. “For the first game in the Premier League it’s possible but I don’t think so.” United’s money-spinning tour of the US started amid a blaze of publicity in Los Angeles, but two-and-a-half weeks later, their presence in the US is a lot more low-key. Only a couple of hundred invited guests turned up at the Sun Life Stadium to watch United’s final training session in America. The session was more of a warm-down as they only played Real Madrid on Saturday night. On the eve of the match, Liverpool manager Brendan Rodgers said Van Gaal is facing a totally different challenge to any other he has faced in his long and successful career. Van Gaal, who has won titles in Spain, Holland and Germany, says he is up to the challenge. “That’s why I’m here,” he said. “Maybe he is right because I have to experience that but I was also in Spain and in my first year I won three titles, in Germany I won two titles. “If I win one here we will all be happy.” Van Gaal is expected to ring in the changes for the final in Miami, which kicks off at 1am BST on Tuesday. The winner takes home a prize of one million US dollars (£600,000). Javier Hernandez, Shinji Kagawa and Wilfried Zaha face uncertain futures after limited playing time in America while Marouane Fellaini and Anderson, who have not made the trip, could also be shown the door. Van Gaal wants to tell his players whether they have made the cut well before the transfer window closes so he will approach them individually and inform them of their fate when they get back to England. “I shall make judgements after the tour,” the United boss said. “I have let all the players play so I know now more than I did before. “But in football you have to judge. Always you have to give a chance to a player to make a transfer when you see that his perspective is not so high to play. “You have to say it in advance. When you say it on August 31st it’s too late. I shall say to the players what I think after the tour.” Van Gaal has sent coach Marcel Bout back to England to work with the likes of Robin van Persie, Adnan Januzaj, and Fellaini, who have been given time off following their exploits at the World Cup. “They (Van Persie, Fellaini and Januzaj) have already trained. I sent Marcel Bout back to train them, along with Nicky Butt,” Van Gaal said. Press Associationlast_img read more

T&T government defends gas deal with Venezuela

first_imgThe Trinidad and Tobago government has brushed aside criticisms relating to the new gas agreement it signed with Venezuela over the weekend even as the opposition United National Congress (UNC) called for the terms regarding the price of gas under the accord to be made public.Opposition concerned “We in the Opposition were always concerned with this agreement given the economic hardship being experienced by the Venezuelan government as well as this government’s track-record of incompetence,” said UNC chairman, David Lee.Lee said the party’s concerns have been raised by the failure by Caracas to meet the payments for goods sent to the South American country in recent months.“It is therefore unacceptable and irresponsible that over one year since these questions were first posed and over two years since goods were first shipped to Venezuela manufacturers have not been adequately compensated,” he said.Months of negotiation But Energy Minister, Franklin Khan, told reporters the gas agreement was reached after “months of negotiation, serious intervention, serious sharing of information and serious sharing of economic models, to come up with an appropriate gas price.It is no cheap gas. It is competitively priced gas and is obviously no secret Dragon deal,” Khan said, adding that Venezuela has the largest oil reserves in the world, larger than Saudi Arabia, Russia and the United States and has the fifth largest gas reserves in the world, which this country can benefit from.“It’s a win-win situation, especially since we in Trinidad face challenges on the supply side,” he said, noting that Trinidad and Tobago has world-class gas infrastructure through which Venezuela can monetize its gas.Last Saturday, Prime Minister Dr. Keith Rowley and Venezuelan President Nicolas Maduro signed the agreement allowing for the importation of natural gas from Caracas.The terms of the agreement is between the National Gas Company (NGC), the Venezuelan NGC, Shell and the Venezuelan state-owned oil and natural gas company, Petróleos de Venezuela, S.A. (Petroleum of Venezuela).last_img read more