FacebookTwitterLinkedInEmailPrint分享Science Magazine:Floating wind turbines at sea could create up to three times as much electricity as turbines on land, increasing the energy potential for a technology that has yet to be proven at scale, a new study suggests.Scientists at the Carnegie Institution for Science in Palo Alto, California, wanted to know whether turbines installed in the open ocean—where air currents are 70% stronger than on land—would also face wind shadow problems. So they conducted virtual experiments using a climate model, and in today’s issue of the Proceedings of the National Academy of Sciences atmospheric scientist Anna Possner and climatologist Ken Caldiera report that turbines placed in the North Atlantic could produce three times as much power as an existing wind farm in Kansas of similar size. Driving this greater potential are wintertime low-pressure systems, which occur more frequently at sea than land. They efficiently mix energy from fast, upper level winds down to the surface of the ocean, speeding surface winds. That means offshore wind turbines in close proximity would still encounter each other’s wind shadow, the authors write, but the wind speed would recover because of the replenished energy, allowing for sustained high power.The authors say their findings should spur companies to try to overcome those obstacles, however, estimating that offshore wind farms in the North Atlantic alone “could potentially provide civilization-scale power.”More: Offshore wind farms have powerful advantage over land-based turbines, study finds Report: Offshore Wind Can Produce ‘Civilization-Scale Power’
Rating the NFL Draft Combine prospects for the USC Trojans is a risky exercise — heck, rating the prospects of any draft hopeful is mired in speculation. But one can’t help but wonder how a certain player might perform at the next level. The Trojans have seen their share of NFL successes (Troy Polamalu, Brian Cushing, Clay Matthews and R- – – -e B – – h come to mind).How Trojans fare in the NFL does play into more than just school spirit — the performance of players in the NFL and the subsequent social capital they gain as standout performers will in turn assist in recruiting down the road. For instance, B – – h’s time at ’SC was instrumental in signing five-star athlete Adoree’ Jackson. The Detroit Lions running back and former Trojan standout experienced a small renaissance with the Lions this past season, recording more than 1,500 all-purpose yards in 14 starts.But not every Trojan has the makings of such success, and the conclusion of the NFL Combine served as a sobering reality check for many of the Trojans’ pro-hopefuls. I’ve ranked the NFL potential of the Trojans’ skill players who participated in the NFL Scouting Combine this past week.Marqise Lee (WR) Former Penn State running back and USC Trojan transfer Silas Redd was part of the Trojans’ highly-touted offense in 2012 but injuries and the Trojans’ choice to employ running back-by-committee in 2013 hurt Redd’s draft stock to the point where Redd is not projected to be drafted in this year’s upcoming draft.Redd’s biggest question mark is the stability of his surgically repaired knee, which sidelined the former Trojan tailback for eight games last season. His 4.68 40-yard dash time didn’t exactly have scouts jumping up and down, but Redd’s greatest asset as a runner was his toughness and ability between the tackles. During the Trojans’ 2012 season it almost felt as if Redd could fall forward for a gain of four or five yards per carry.Verdict: Redd’s durability as a runner, his versatility catching passes out of the backfield and his willingness to pick up blocks on off-plays would make him an effective addition to any NFL team’s depth chart — provided his knee has fully recovered and gets the chance. Unfortunately, this is a perception-driven industry and Redd may be too much of a dark horse to make it to the Monday night lights. The 2012 Biletnikoff Award winner had a lackluster, injury-ridden 2013 campaign with junior quarterback Cody Kessler at the helm. Lee clocked an unremarkable time of 4.52 seconds in the 40-yard dash, which was slowest of all Pac-12 wide receivers. Aside from speed, one of Marqise Lee’s biggest problems in 2013 was, surprisingly, his pass-catching ability. Though Lee promised “zero drops” in a preseason press conference last spring, the former Trojan wide receiver struggled to build chemistry with Kessler and was frequently overthrown or dropped passes that were on target.Lee compensated at least partially for his performance this season in the Trojans’ bowl game against Fresno State. The wideout looked like his old self, hauling in seven receptions for 118 yards and two touchdowns. But it’ll be difficult to prove to scouts that he’s the same receiver who ripped apart Pac-12 secondaries in 2012 without quantitative combine statistics to back up his claims.As for his draft prospects, it would be ideal for Lee to fall into the lap of a team with an established, stable quarterback who can get him the ball in the vein of a Tom Brady with New England or Drew Brees with New Orleans. Lee still has the upper body control and instincts to make defenders miss once he has the ball in his hands, and could be a consistent big play threat in the NFL.The verdict: starter. With the vast majority of teams who don’t have two high-caliber starting wide receivers, Lee will be a day-one starter in the NFL — and under the right circumstances, he is capable of making the Pro Bowl.Xavier Grimble (TE) At 6-foot-5, 255 pounds, Xavier Grimble has the prototypical body of a hybrid tight-end. With the current trend of tight end-centered offenses, Grimble has perhaps the brightest prospects of any Trojan as far as potential for use in the NFL. Grimble’s sturdy frame is conducive to effective blocking, even at the next level.Grimble’s greatest asset also happens to be Lee’s current weakness: hands. The Trojan’s high-powered offense in 2012 included countless drives that were saved, or punctuated by, Grimble snatching a Matt Barkley spiral over the middle on an intermediate route. Though Grimble’s 2013 season was, like Lee’s, unremarkable, much of it could be attributed to former head coach Lane Kiffin and offensive coordinator Clay Helton’s play calling. The Trojans’ tight ends were woefully under-utilized in 2013 and Grimble did not have an opportunity to showcase his playmaking gifts.Verdict: eventual starter. Former USC head coach Ed Orgeron went on the record with Fox Sports to say that Grimble could project as an all-pro tight end in the NFL, but my projection is slightly less optimistic. Provided Grimble gets the reps on a professional team to start with, he could be a solid starting tight end option on a multitude of NFL teams that utilize a tight-end set on offense.Silas Redd (RB) Euno Lee is a senior majoring in English literature. He is also the co-managing editor of the Daily Trojan. His column, “Euno What Time it is,” runs Wednesdays.