Blogs

Material gain

first_imgScientists from Harvard University and the Massachusetts Institute of Technology have developed a theoretical model of a material that one day could anchor the development of highly efficient solar panels.Traditional organic solar panels work by combining photons with light-sensitive materials, creating particles called excitons. Those particles are then channeled through the material to an interface, where they dump energy into electrons that flow along wires, producing electricity. The problem is that excitons aren’t easy to control. The particles are often trapped by defects in the material, and release their energy as light, reducing the efficiency of the panels.Inspired by cutting-edge theories in condensed matter physics and the development of quantum computers, the Harvard-MIT group used magnetic fields to force excitons to move in a specific direction, avoiding the traps that plague traditional materials. The system is described in a paper in Nature Materials.The research team was led by Professor of Chemistry and Chemical Biology Alan Aspuru-Guzik and included Joel Yuen-Zhou, a former Ph.D. student in Aspuru-Guzik’s lab who is now a postdoctoral fellow at MIT, and research associate Semion Saikin.“This effect has been identified in physics, in what’s called the quantum Hall effect, and in topological insulators, but we believe this is the first time this has been proposed in a practical way for excitons in molecular layers,” Aspuru-Guzik said. “What we wanted to ask was, can this be done in organic materials? Can you custom-tailor an organic material in such a way that, for certain excitation energies, excitons move in one direction, and when they confront obstacles, they can move around them?”Yuen-Zhou and Saikin began searching for molecules that fit a tightly defined set of criteria, and eventually settled on porphyrins, in part because they have been extensively studied.“These are just one example of a molecule that could work in this system,” said Saikin. “We don’t want to say that, experimentally, one has to do it with these molecules, but conceptually, we’ve shown that the electronic structure of these molecules is convenient for this system.”The system described in the paper, however, is about more than simply creating a film of porphyrin molecules.For the design to work, the team outlined how magnets could be used to prepare the molecules in specific quantum states to ensure they don’t interfere with one another.“In the absence of a magnetic field, it’s equally likely the excitons would go in one direction or another,” Aspuru-Guzik said. “We use some very clever quantum tricks, to ensure that, when we apply the field, one direction becomes more preferential.”Just as cars sitting in traffic on the highway are unable to turn around and drive in the opposite direction, Aspuru-Guzik said, excitons in this system are able to flow in only one direction, around the edges of the film.What’s more, Yuen-Zhou said, the quantum mechanics of the system permit a good deal of flexibility, allowing excitons to flow around defects in the material, just as a stream flows around obstructions.While it may be years before the material finds its way into commercial solar panels, Aspuru-Guzik believes it has the potential to increase their efficiency by creating a flow of excitons that moves along the panel’s interface, more efficiently transferring energy into electricity.“What we’ve done with this paper is a proof of concept, and we hope it’s the opening to a new era of excitonics.”last_img read more

DPS officer killed in double homicide

first_imgA Dept. of Public Safety officer and his fiancee were found late Sunday dead from gunshots in a parked car in Irvine, Calif.The victims, who were found in the vehicle at about 9:10 p.m., were identified as Keith Lawrence, 27, and Monica Quan, 28. Gunshots were not reported that night, and the bodies were only found after a passerby noticed Lawrence slumped over the steering wheel, according to police. Law enforcement officials are continuing to investigate the crime as a double homicide, not a murder-suicide.Lawrence joined DPS in August 2012 and at the time of his death was assigned to patrol operations, according to DPS Capt David Carlisle. He was an armed officer and a graduate of the Ventura County Sheriff’s Academy. His fiancee Quan was a assistant basketball coach for the Cal State Fullerton women’s team. Both were graduates of Concordia University.DPS Chief John Thomas released a statement Monday regarding the shooting:“It is with great sadness and a very heavy heart that I announce the untimely death of a member of the DPS Family, PSO I Keith Lawrence.  Officer Lawrence and his fiancée were discovered deceased earlier this morning; victims of a senseless act of violence in the City of Irvine.During his brief tenure of service here at USC, Officer Lawrence proved to be an honorable, compassionate and professional member of our department and the Trojan Family.  We are a better department and the USC Campus Community is a safer place as a result of his service.Please continue to espouse those same values of honor, commitment to duty, professionalism and compassion as we continue to add to his legacy and those that we all share as members of the law enforcement/public safety community.I would also ask that you remember Keith and his fiancée’s families in your thoughts and prayers as they grieve and begin the healing process and move forward from this tragic loss of their loved ones.”last_img read more

McHugh launches new archive revealing incredible Flight of the Earls texts

first_imgDONEGAL TD and Minister for Gaeilge Joe McHugh has launched a new online archive of gaelic texts spanning three centuries and including reports of the Flight of the Earls from Donegal in 1607.Staff of the Royal Irish Academy based in Teelin in Co Donegal were part of a team which put together 19 million words from various texts from across Europe into the incredible online resource.The texts – mostly in old Irish – have been edited for the modern day user and include accounts of that famous flight from Rathmullan, from the Great Famine right through to the Easter Rising and Partition. Launching the Corpas na Gaeilge 1600-1926, a historical corpus of the Irish language from that period, Minister McHugh paid tribute to Tyrone native Dr Charles Dillon and his team in Donegal for their work over many years.Minister McHugh with Dr Charles Dillon, a native of Benburb, Co TyroneIn Carrick Caroline Ní Chasaide, Pádraig Mac Con Uladh, Niall O Ceallaigh and Eithne Ní Ghallchobair have worked painstakingly to reproduce these texts into a format on the Royal Irish Academy website at www.ria.ie – all now searchable using key words.“The Royal Academy of Ireland in Dublin has been working on the project for some years and their staff members based in An Charraig in Co. Donegal digitise the material,” said Minister McHugh whose department funds the project.Minister McHugh with Caroline Ní Chasaide and Pádraig Mac Con Uladh pictured at the launch at the RIA HQ in DublinMinister McHugh added: “The Corpas covers a huge breadth of material and Irish history, from the Flight of the Earls in 1607 to the writings of An tAthair Peadar Ó Laoghaire and Pádraig Mac Piarais in An Claidheamh Soluis, during the golden age of the language revival. “Every aspect of this project is challenging and I would like to take this opportunity to congratulate all staff working on it. They are doing fantastic work in various areas including Irish history, archaeology, the Irish language, culture and science.“I am very proud that the Department of Culture, Heritage and the Gaeltacht is part of this valuable project. I’m pleased that my Department was in a position to provide assistance of over €1.62m for the work being done by the Academy on this dictionary over the years.“As promised in the 20-Year Strategy for the Irish Language, the development and support will continue, in order to ensure that Foclóir Stairiúil na Gaeilge is completed and that the modern needs of the language are met.”McHugh launches new archive revealing incredible Flight of the Earls texts was last modified: October 25th, 2017 by Rachel McLaughlinShare this:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Pocket (Opens in new window)Click to share on Telegram (Opens in new window)Click to share on WhatsApp (Opens in new window)Click to share on Skype (Opens in new window)Click to print (Opens in new window) Tags:archivecorpasflight of the earlsGaelichistoryMinister McHughrialast_img read more