Model of the energization of outer-zone electrons by whistler-mode chorus during the October 9, 1990 geomagnetic storm

first_img[1] Relativistic (> 1 MeV) ‘killer electrons’ are frequently generated in the Earth’s inner magnetosphere during the recovery phase of a typical magnetic storm. We test the hypothesis that the energization of electrons takes place by means of stochastic gyroresonant interaction between lower-energy (several 100 keV) seed electrons and whistler-mode chorus waves. We develop a model kinetic equation for the electron energy distribution, and utilize both electron and whistler-mode wave data at L=4 for a typical geomagnetic storm (on October 9, 1990) from instruments carried on the Combined Release and Radiation Effects Satellite (CRRES). Our model solutions are found to match well with the CRRES profiles of the electron flux. We conclude that the mechanism of stochastic acceleration by whistler-mode turbulence is a viable candidate for generating killer electrons, not only for the storm considered, but for similar storms with a several-day recovery phase containing prolonged substorm activity.last_img read more

Terence Crawford’s last five fights

first_imgSummary: Before they event stepped inside the ring, Molina missed weight by four pounds and was ineligible to claim the WBC and WBO championships. Crawford made an out-of-shape Molina pay for failing to meet his end of the bargain. He pounded Molina the entire way with the jab, pot shots on the inside and his right hand. Finally, Crawford put Molina out of his misery in the eighth round when he uncorked a barrage of punches to Molina. Moments later, Crawford blasted Molina with three straight right hands and the referee stopped the fight to hold onto his belts. With boxing’s welterweight division surging, there may be no better guy to carry the weight class than WBO welterweight champion Terence Crawford.Watch Terence Crawford vs. Amir Khan on FITE.TV The former undisputed junior welterweight champion will compete for the first time in 2019, as he defends his title when he takes on Amir Khan on April 20 from Madison Square Garden in New York City.Crawford (34-0, 25 KOs) put himself on the map in March 2014 when he ventured over to Scotland and defeated Ricky Burns to capture the WBO lightweight title. After two successful defenses, Crawford moved up to 140 pounds in 2015 and scored a sixth-round TKO over Thomas Dulorme to win the WBO belt to start his run of eight stoppages in his next nine fights. The native of Nebraska added the WBC belt in July 2016 when he beat Viktor Postol by unanimous decision. Then in August 2017, Crawford became the king of the junior welterweights by blasting through WBA and IBF champion Julius Indongo in three rounds. Doing everything he could at junior welterweight, Crawford made the seven-pound leap and beat Jeff Horn to become the WBO titlist. Let’s take a look at the last five fights of Terence Crawford before perhaps the biggest fight of his career.MORE: Terence Crawford vs. Amir Khan: Odds, expert pick and how to bet on fightTerence Crawford vs. José Benavidez Jr.Fight date: Oct. 13, 2018Result: Crawford wins by 12th round TKOSummary: All of Crawford’s fights up to this point had been low-key because respect of some sort being shown along the way. Until this fight.Throughout the build-up, Benavidez slung verbal barbs left and right. The boiling point came up when Crawford nearly threw a punch at him at the weigh-in.Crawford wanted to show Benavidez that he didn’t belong in the same ring as him. He accomplished that, and he made it look easy, too, as he dominated the entire fight to defeat an overmatched Benavidez. Crawford really wanted to finish Benavidez off to not only leave a definitive statement to his foe, but to the rest of the welterweight division. Crawford did just that when he landed a straight left hand, immediately followed by a short, crisp right uppercut to send Benavidez flipping onto the canvas. Knowing he had Benavidez right where he wanted him, Crawford unloaded a barrage of punches until the referee stopped the fight with 18 seconds remaining to successfully defend the WBO title for the first time and let everyone know he was here to stay.Terence Crawford vs. Jeff HornFight date: June 9, 2018Result: Crawford wins via ninth-round TKO.Summary: The biggest question heading into the fight was whether Crawford’s power would carry with him from 140 to 147 pounds. To the surprise of many, Horn began the fight being the aggressor and coming right at Crawford. It didn’t take Crawford long to adapt and figure Horn out. He started doling out a heavy volume of punishment. Somehow Horn kept trudging through and giving it all he could.However, Crawford got to him in the ninth round when he sent Horn to the canvas with an overhand left hand. The Australian made it back to his feet, but Crawford rushed right at Horn and unloaded a barrage of shots. The referee had seen enough and put a halt to the fight and Crawford won the WBO strap to become a three-division world champion.Terence Crawford vs. Julius IndongoFight date: August 19, 2017Result: Crawford wins via third-round knockout.Summary: Crawford was on the verge of making history. A win and he would be the undisputed junior welterweight champion. He did just that and put on the best performance of his career. Crawford used his speed to entice Indongo to come at him and be and anytime Indongo threw, he would miss, be off balance and Crawford would rip the body. With 30 seconds left in the second round, Crawford hit Indongo with a short left behind to send him to the mat.In the third round, Crawford closed the show in front of his hometown crowd in Omaha when he hit Indongo with a left hand followed by a vicious right to the body to drop Indongo and become the undisputed king at 140 pounds and cement himself as one of the premiere boxers in the sport.Terence Crawford vs. Felix DiazFight date: May 20, 2017Result: Crawford wins by tenth-round TKO.Summary: On paper, the 2008 Olympic gold medalist looked to be Crawford’s stiffest test. Not everything on paper comes to be true, as Crawford dominated from the outset. He fought from the outside and continously peppered the jab, which caused Diaz’s right eye to nearly close and forced his trainer Joel Diaz to tell the referee his guy could no longer continue.Terence Crawford  vs. John Molina Jr.Fight date: December 10, 2016Result: Crawford wins via eighth-round TKO.last_img read more

Shaquille ONeal Boys and Girls Clubs of America and Dr Pepper Snapple

first_imgBoys & Girls Clubs of America and Dr Pepper Snapple Group announced today the launch of a digital yearbook, gathering photos and signatures from Club alumni, donors and supporters.The Alumni & Friends Yearbook was created as a platform for alumni to reconnect with fellow Club kids, share stories about their Boys & Girls Club experiences and make new connections with alumni across the country. Participants can sign the yearbook at bgca.org/yearbook.One lucky Boys & Girls Club alum or supporter who signs the yearbook between now and October 5, 2018, will win an in-person celebrity experience with Club alum Shaquille O’Neal, along with a $10,000 donation to a local Boys & Girls Club of their choice. Boys & Girls Clubs has nearly 16 million living Club alumni, including celebrities like Denzel Washington, Misty Copeland, Shaquille O’Neal and business leaders like Dr Pepper Snapple president and CEO Larry D. Young. These alumni and many others come from all walks of life but share a common bond through their Boys & Girls Club experience.“The foundation of the Boys & Girls Club experience can be life-changing and life-saving for so many kids, especially those who need us most,” said Jim Clark, president & CEO of Boys & Girls Clubs of America. “The collective strength of our Alumni & Friends help reconnect members and supporters while giving back to the next generation of Club kids.”Thanks to Dr Pepper Snapple, Boys & Girls Clubs of America is creating a network of passionate Club Alumni & Friends who can support and provide mentorship to current Club members and other alumni. By reconnecting with the Boys & Girls Club community through Alumni & Friends, former Club kids and supporters can also be powerful advocates for Clubs and the kids and communities they serve.“The lessons I learned and experiences I gained as a Club kid in Springfield, Mo., helped shape who I am today,” said Young. “With the Alumni & Friends Network, former Club kids have access to invaluable mentorship and other resources that help light pathways to successful and rewarding lives, and this digital yearbook is a great way for alums to make those connections.”The Boys & Girls Clubs continues to have a major impact on its members past graduation, with more than 54 percent of Boys & Girls Club alumni say the Club saved their life. For more information on Boys & Girls Clubs Alumni & Friends, go to www.bgca.org/alumni.last_img read more