Building invisibility cloaks starts small

first_imgResearchers in applied physics have cleared an important hurdle in the development of advanced materials, called metamaterials, which bend light in unusual ways.Working at a scale applicable to infrared light, the Harvard team has used extremely short and powerful laser pulses to create 3-D patterns of tiny silver dots within a material. Those suspended metal dots are essential for building futuristic devices like invisibility cloaks.The new fabrication process, described in the journal Applied Physics Letters, advances nanoscale metal lithography into three dimensions — and does it at a resolution high enough to be practical for metamaterials.“If you want a bulk metamaterial for visible and infrared light, you need to embed particles of silver or gold inside a dielectric, and you need to do it in 3-D, with high resolution,” says lead author Kevin Vora, a graduate student at the Harvard School of Engineering and Applied Sciences (SEAS).The optical table in Professor Eric Mazur’s laser laboratory at Harvard. Using femtosecond lasers, Mazur and colleagues have developed a new nanofabrication process for use in creating metamaterials.“This work demonstrates that we can create silver dots that are disconnected in x, y, and z,” Vora says. “There’s no other technique that feasibly allows you to do that. Being able to make patterns of nanostructures in 3-D is a very big step towards the goal of making bulk metamaterials.”Vora works in the laboratory of Eric Mazur, Balkanski Professor of Physics and Applied Physics at SEAS. For decades, Mazur has been using a piece of equipment called a femtosecond laser to investigate how very tightly focused, powerful bursts of light can change the electrical, optical, and physical properties of a material.When a conventional laser shines on a transparent material, the light passes straight through, with slight refraction. The femtosecond laser is special because it emits a burst of photons as bright as the surface of the sun in a flash lasting only 50 quadrillionths (5 × 10-14) of a second. Instead of shining through the material, that energy gets trapped within it, exciting the electrons within the material and achieving a phenomenon known as nonlinear absorption.Inside the pocket where that energy is trapped, a chemical reaction can take place, permanently altering the internal structure of the material. The process has previously been exploited for 2-D and simple 3-D metal nanofabrication.“Normally, when people use femtosecond lasers in fabrication, they’re creating a wood pile structure: something stacked on something else, being supported by something else,” explains Mazur.“If you want to make an array of silver dots, however, they can’t float in space.”In the new process, Vora, Mazur, and their colleagues combine silver nitrate, water, and a polymer called PVP into a solution, which they bake onto a glass slide. The solid polymer then contains ions of silver, which are photoreduced by the tightly focused laser pulses to form nanocrystals of silver metal, supported by the polymer matrix.The need for this particular combination of chemicals, at the right concentrations, was not obvious in prior work. Researchers sometimes combine silver nitrate with water in order to create silver nanostructures, but that process provides no structural support for a 3-D pattern. Another process combines silver nitrate, water, PVP, and ethanol, but the samples darken and degrade very quickly by producing silver crystals throughout the polymer.With ethanol, the reaction happens too quickly and uncontrollably. Mazur’s team needed nanoscale crystals, precisely distributed and isolated in 3-D.“It was just a question of removing that reagent, and we got lucky,” Vora says. “What was most surprising about it was how simple it is. It was a matter of using less.”SeungYeon Kang, a graduate student at SEAS, and Shobha Shukla, a former postdoctoral fellow, co-authored the paper. The work was supported by the Air Force Office of Scientific Research.last_img read more

Saving Mother Earth

first_imgEarth Day was created as a call to action, to raise awareness and spur a movement focused on the steps people need to take to rethink how they live on this planet. That spirit lives on every day at Harvard in its laboratories, its classrooms, and in how the campus operates. Substantive and scalable solutions to the challenges of climate change and sustainable development are most powerful, analysts say, when they are generated at the intersection of disciplines, powered through the ingenuity of students, and connected to real-world problems locally. The Harvard Climate Change Solutions Fund is one example of how the University is catalyzing the research and innovations needed to accelerate progress toward cleaner energy and a healthier, more sustainable future.last_img

Journalist shares research on press safety in Mexico

first_imgKatherine Corcoran, a Kellogg Institute for International Studies Hewlett fellow for public policy, spoke at the Hesburgh Center for International Studies on Tuesday about why an increasing number of journalists are being murdered in Mexico, even as the country is becoming more democratic. Mexico is now one of the most dangerous countries in the world for journalists, Corcoran said — she knows this firsthand. Corcoran worked in the Associated Press’ Mexico bureau as an enterprise editor overseeing features and special investigations, and then as its bureau chief. She interacted with other journalists who were later killed, allegedly for doing their jobs, she said. “Mexico is not a country at war,” Corcoran said. “The shocking thing to me was that so many journalists were being killed in a democracy.” After a year researching this issue as a Kellogg fellow, Corcoran concluded that three factors have contributed to the high number of journalist murders in recent years: impunity, weak government institutions and the relationship between drug cartels and political figures. Corcoran noted that government statistics say 99.6 percent of aggressions against journalists (i.e. equipment seizure, threats, assaults, murders) go unprosecuted. “Impunity is a huge problem,” Corcoran said. “So the reason you kill a journalist in Mexico is because you can.”Impunity is the result of weak government institutions, she said. “Everyone says Mexico is a democracy, but anybody who really knows Mexico will say that Mexico never had a full transition to a democracy,“ Corcoran said. “What people there now call it is an electoral plurality — but the institutions never did the full transformation and they remain very weak.”Mexico’s transition to democracy has also brought a redistribution of power to state and local governments, Corcoran commented, which has encouraged more relationships between drug cartels and political figures. Sometimes journalists are killed by drug cartels for the cartels’ own reasons, but Corcoran said most of the time journalists are killed by cartel members on behalf of political officials. However, those cases are also the most difficult to prove. “The closer the case is to the government, the less [of a] chance [there is] that it will be investigated, and the more [of a] chance [there is] that they will try to blame narcos or some other entity for killing the journalist,” Corcoran said. According to the Committee to Protect Journalists’ website, 44 journalists have been killed in Mexico since 1994 in cases in which there was a confirmed motive tied to the journalist’s work and an additional 53 have been killed without a confirmed motive. “People say, ‘Why are all these journalists being killed in Mexico every year?’ And everybody says it’s the narcos,” Corcoran said. However, she said, in reality the highest number of aggressions against journalists are the work of public officials or some other representative of the government.Corcoran said between 2009 and 2017, 273 of 2,765 total aggressions were committed by organized crime, but 1,352 were committed by public officials. She also noted that according to the Mexican government’s own statistics, 42% of aggressions — not just murders — against journalists were committed by public officials. Overall, aggression against journalists has been increasing every year since 2009, she said, but there are small groups of journalists who are beginning to fight back.“There was no investigative reporting of any merit before in Mexico,” Corcoran said. Recently, however, she said a small group of reporters has begun to investigate corruption in Mexico while training younger journalists to do so as well.“Even though it’s a small movement, it is a movement,” Corcoran said.Tags: Democracy, journalist, Katherine Corcoran, Mexico, Mexico journalistslast_img read more

CBO: It May Take The U.S. Economy A Decade To Heal From COVID-19 Impacts

first_imgPhoto: PixabayWASHINGTON – A lost decade for America’s Economy, that could be what lies ahead according to the Congressional Budget Office.On Monday the office said it could take most of the next ten years for the U.S. Economy to recover from the impact of the Coronavirus.The office warns the pandemic will cut economic output over the next decade by $7.9 trillion, or three percent of GDP during the decade. That’s compared to projections from January.The total damage comes to $15.7 trillion, or 5.3 percent of GDP and that’s without accounting for inflation. The office clarified its statement though, cautioning that there is a lot of uncertainty in its forecasts.That’s because the course of the pandemic is unknown, and it’s not clear how the economy will respond. Share:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to email this to a friend (Opens in new window)last_img read more

Bar website now has better access

first_img February 15, 2002 Regular News The Florida Bar’s website, www.FLABAR.org, has a new feature and a new server which will make navigating the site quicker and easier.Earlier this month, the Bar moved to a “frames” version of the website, which offers users separate, scrollable regions and provides a drop-down menu for each section of the site.The new website server provides faster communication between a user’s computer and the server, said Patricia Hohman, the Bar’s website coordinator. And, the drop-down menus will allow users to view the contents of a section before clicking on that page.The entire website is now maintained using LotusNotes databases, allowing Bar staff to update the site more frequently, Hohman added.“Some users may need to refresh their browser to see the new site,” she said. “Users having trouble viewing the site may need to clear their browser’s cache.”Typically, Internet browsers such as Netscape Navigator and Internet Explorer save copies of frequently visited pages (called your “browser cache”) to your computer’s hard-drive, which your browser may access the next time you view a particular website.To clear your browser’s cache:• In Internet Explorer, go to “Tools,” then “Internet Options.” Under the “General” tab, click “Delete Files” in the “Temporary Internet Files” category. Click “OK,” then “OK” again to exit, then click “Refresh” in your browser or type the Bar address in the browser location bar.• In Netscape Navigator, go to “Edit,” then “Preferences.” In the “Category” bar on the left, double-click “Advanced,” then “Cache.” Next, click “Clear Memory Cache” and “OK,” then “Clear Disk Cache” and “OK.” To exit, click “OK,” then refresh your browser. Bar website now has better accesscenter_img Bar website now has better accesslast_img read more

Bellport Crash Leaves Woman Dead

first_imgSign up for our COVID-19 newsletter to stay up-to-date on the latest coronavirus news throughout New York A 62-year-old East Patchogue woman was killed when her SUV was involved in a crash with another truck in Bellport on Monday afternoon.Suffolk County police said Geraldine Schneider was driving a Ford Explorer that had just turned onto Station Road when a second Ford Explorer hit her truck near the corner of Farber Drive at 12:55 p.m.Schneider was pronounced dead at the scene. The other driver and a passenger in her vehicle were taken to Brookhaven Memorial Hospital in East Patchogue, where they were treated for non-life-threatening injuries and released.Fifth Squad detectives impounded the SUVs, are continuing the investigation and ask anyone who may have witnessed the crash to call them at 631-854-8552.last_img read more

Chenango County Dairy Day canceled

first_imgNORWICH (WBNG)- The Chenango County Dairy Day has been canceled for this year. According to a news release sent by the Chenango County Dairy Day Committee, they said that the 20th Annual Dairy Day celebration. For the past nineteen years, Dairy Day has been a fantastic community event, drawing hundreds of people to celebrate the history and impact of agriculture in our county. Committee members were looking forward to the 20th celebration of dairy in Chenango County. While Junes date is not a possibility this year, there are possibilities for a different kind of celebration later in the year. Especially in times like this, a celebration of dairy and agriculture is particularly important. Organizers said in a statement, The event was originally scheduled for June 20.last_img

Donut Rucking with the Cider Mill 5K or 10K walk

first_imgENDICOTT (WBNG) — The JTM Ruck Club held a Donut Rucking with the Cider Mill 5K & 10K this morning in Endicott. During their journey, the group made a stop at the Cider Mill to grab some donuts before finishing their ruck back at the Roundtop Picnic Area.  Based out of Cortland, club founder Dustin Sherman says he wanted to do this event in a new place that he’s never been to.  Participants carried backpacks weighing up to 20 pounds on their ruck, and some even chose to carry their children! Rucking is carrying around a weighted backpack or some other type of load from point A to point B, usually a significant distance.  “I heard the Cider Mill was a nice place to go to,” Sherman said. “And why not? Change of environment and scenery.”  Sherman also says he was grateful for everyone who showed up to participate today.last_img read more

VICTour tourism project – Virtual and cultural tourism presented

first_imgAn initial conference was held in Vukovar yesterday, presenting to the public the tourist project  Virtual and Cultural Tourism  – ViCTour.The project is co-financed by the  InterregIPA cross-border cooperation program Croatia-Serbia  2014-2020. It aims to develop attractive, dynamic and competitive tourism promotion in order to increase the attractiveness of cross-border regions using IT tools such as holograms, augmented reality, interactive totems, etc. to improve the cross-border tourist offer and ensure better management of cultural and natural heritage.Virual and cultural tourism ”is the name of the tourist project implemented by the Vukovar-Srijem County and the Tourist Board of the Vukovar-Srijem County in cooperation with partners from Vojvodina. It is a project with a total value of over 920,000 euros, of which the EU co-finances costs in the amount of 85 percent. Within the project, which started on June 17 and lasts for 28 months, a number of tourist activities will be carried out, study trips will be organized, tourist guides will be trained, as well as various modern IT equipment will be procured.The value of the project is € 924,327, of which Vukovar-Srijem County has € 280,000 at its disposal as the holder of this project. As part of the project, a number of tourist activities will be carried out, study trips will be organized, tourist guides will be trainedDirector of the Vukovar-Srijem County Tourist Board Rujana Bušić Srpak pointed out that within this project, which is actually a continuation of the previous project “Natives”, she will make holograms of some famous people who were born or lived in some part of their lives in Vukovar-Srijem county. ” We are talking about people like Lavoslav Ruzicka, Ivana Kozarac, Nikola Iločki and St. Ivana Capistrano. Through modern technologies, that is, through holograms, tourists will be shown how these people once lived. I believe in the great interest of tourists for this tourist project “, explained Bušić Srpak, Press032.com reportsThe project partners are the Tourist Board of Vukovar-Srijem County, the Tourist Organization of Vojvodina, the Faculty of Economics in Subotica and the European Affairs Fund of the Autonomous Province of Vojvodina.last_img read more

S. Koreans return to work, crowd parks, malls as social distancing rules ease

first_imgTopics : South Korea’s ongoing recovery from the first major coronavirus outbreak outside China paints a stark contrast to many other countries where metropolises remain sealed off and sweeping stay-at-home orders are in place.”I’m a member of a community football club and we went out to play on Saturday for the first time in two months,” said Kim Tae-hyung, a 31-year-old power plant engineer living in Seoul. “We were wearing a mask while we played, still worried about the coronavirus, but the weather was nice and I felt so refreshed.”South Korea extended its social distancing policy for another 16 days on Sunday but offered some relief for religious and sports facilities previously subjected to strict restrictions.The decision is aimed at cautiously reopening Asia’s fourth-largest economy as daily infections continue to hover around or less than 20, most arriving from overseas. South Koreans are returning to work and crowding shopping malls, parks, golf courses and some restaurants as South Korea relaxes social distancing rules amid a continued downward trend in coronavirus cases.A growing list of companies, including SK Innovation and Naver, has ended or eased their work from home policy in recent weeks, though many continue to apply flexible working hours and limit travel and face-to-face meetings.Parks, mountains and golf courses brimmed with visitors over the weekend, while shopping malls and restaurants were slowly returning to normal.center_img Seoul’s defense ministry also said on Monday that the military is resuming medical screening for candidates while considering easing restrictions on travel and guest visits.The Korea Centers for Disease Control and Prevention (KCDC) reported 13 new cases on Monday, a day after posting just eight — the first single digit daily rise since the Feb. 28 peak of 909. The death toll stands at 236.Health authorities urged vigilance, warning new clusters could still emerge at any time, especially after South Korea held the first national election last week since the epidemic began, and ahead of long holidays starting next week.Schools have yet to open and are holding online classes.An official at SK Innovation, a battery maker, said about 80% of its employees will be back this week and they will get a temperature check at the entrance and maintain distance in the office.Naver Corp., which operates South Korea’s largest web portal, said it is allowing less than half its employees to come into the office, while employees at Netmarble , a mobile gaming firm, come into the office three days a week.”We have installed thermal cameras, full-body sterilizers, and table partitions at cafeterias,” Naver said in a statement.Authorities were on alert after a 58-year-old man living in the second largest city of Busan was confirmed with the virus on Saturday and had voted in the election, attended Easter church service and visited restaurants while running symptoms.More than 1,000 people are now quarantined or being checked after coming in contact with that man and his daughter, who is a nurse and has also tested positive, city officials said.”We’re looking at the trend of group infections though it has mostly been small clusters over the past two weeks,” Vice Health Minister Kim Gang-lip told a briefing.”If we let our guard down in social distancing, [the virus] could come back and greatly hurt and endanger our society.” last_img read more