Tag: 上海娱乐地图yldt123

  • 2MW Array under Construction at Dugway Proving Ground

    first_imgA 2-megawatt solar array under construction at Dugway Proving Ground is expected to generate 10 percent of the installation’s electricity needs while enhancing the energy security of the facility located 85 miles southwest of Salt Lake City.“Energy security is vital for the Army mission at Dugway. With aging infrastructure of the commercial power grid and frequent power outages, it’s critical we look at alternate methods to insure an uninterrupted power source,” said Don Smith, Dugway’s new garrison manager.The $7.7 million array requires 1,300 metal posts to hold 3,300 stationary solar panels. The array will save Dugway about $640,000 a year over 25 years, reported Army Test and Evaluation Command.The proving ground already is planning a second 2-megawatt solar array. Officials are exploring other renewable sources as well, including wind and geothermal energy. The installation is considering constructing a microgrid to integrate its various energy resources, said Sean Svendsen, Dugway’s resource efficiency manager.San Diego-based TriEco-Tetra Tech Sustainable Resources Joint Venture is building the array through a contract awarded by the Army Corps of Engineers. Hunt Electrical also is part of the construction team.  Dan Cohen AUTHORlast_img read more

    READ MORE
  • BNP to contest bypolls to Fakhruls seat

    first_imgLogo of BNPBangladesh Nationalist Party (BNP) will participate in the by-election to Bogura-6 parliamentary seat, which fell vacant after party’s secretary general Mirza Fakhrul Islam Alamgir decided not to take oath of office, reports UNB.At a meeting of the BNP-led 20-party alliance on Monday night, Mirza Fakhrul Islam Alamgir said the party will also nominate a candidate for its reserved seat for women.National People’s Party chief Fariduzzaman Farhad told UNB on Tuesday that the BNP secretary general conveyed the alliance leaders about their party’s decision on the by-polls to avert misunderstanding.The meeting was held at the BNP chairperson’s Gulshan office with Fakhrul in the chair.It is, however, unclear whether the party has picked anyone for contesting the by-polls and the reserved seat.The BNP won six seats after contesting the December national election in which the ruling Awami League won 96 per cent seats in the 300-member House.Although the BNP branded the election “full of irregularities”, five of its parliamentarians except Fakhrul have taken oath.last_img read more

    READ MORE
  • Pen draws flexible circuits using halfmeter long carbon nanotube fibers

    first_imgResearchers use a pen to draw half-meter-long carbon-nanotube-based fibers. The technique could be used to fabricate flexible electronic circuits. Credit: Huang, et al. ©2015 American Chemical Society © 2015 Phys.org This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Researchers report progress in development of carbon nanotube-based continuous fibers Diagram of the writing process and images of the ink, pen, and fibers. Credit: Huang, et al. ©2015 American Chemical Society Patterns drawn by hand showing the precision with which the fibers can be controlled. Credit: Huang, et al. ©2015 American Chemical Society In the future, the researchers hope to expand the drawing technique to use different types of ink for different purposes.”We are now working on enabling more functions in the fiber,” Wu said. “For example, one possibility is semiconducting fibers drawn from a pen tip for flexible device applications.” (Phys.org)—While it may look like researchers from Tsinghua University in Beijing are sketching out an idea for a circuit on a piece of paper, they’re actually using a special pen that draws real circuits using carbon-nanotube-based ink.center_img When writing, the pen is lifted off the paper to stretch and suspend the fibers, which can then be laid down on the substrate in the desired position. The researchers demonstrated that complex fiber patterns can be drawn by hand, and they predict that even greater precision can be achieved using advanced mechanical devices.The researchers also showed that increasing the polymer concentration of the ink increases the diameter of the nanotube fibers from 300 nm to 3 µm. In general, thinner fibers have better conductivity than thicker ones due to their better fiber orientation. Tests show that the highly conductive carbon nanotube fibers also exhibit excellent mechanical flexibility. At first, the researchers expected that the ultralong carbon nanotube fibers should maintain their conductivity after bending and distortion. Somewhat surprisingly, their tests showed that the fibers actually exhibit an increase in conductivity after bending—about a 30% increase after 1000 bending cycles. The researchers propose that the stress caused by bending deforms the polymers and improves nanotube alignment, which in turn increases conductivity. Journal information: Nano Letters More information: Sihan Huang, et al. “Direct Writing of Half-Meter Long CNT Based Fiber for Flexible Electronics.” Nano Letters. DOI: 10.1021/nl504150a Citation: Pen draws flexible circuits using half-meter long carbon nanotube fibers (2015, February 20) retrieved 18 August 2019 from https://phys.org/news/2015-02-pen-flexible-circuits-half-meter-carbon.html This technique, called “fiber drawing,” has previously been used to construct patterns, but the fiber length is usually very short at just a few millimeters, and the drawing speed is typically very slow. These drawbacks limit its use in circuit fabrication.In the new study, the researchers demonstrated that their new pen can draw carbon nanotube fibers that are more than a half of a meter long with fast drawing speeds of up to 10 cm/second. Their work is published in a recent issue of Nano Letters.Due to the nanotube fibers’ high conductivity and excellent mechanical flexibility, the researchers predict that the fibers could serve as the fundamental building blocks for a wide variety of flexible electronic devices, such as wearable electronics, flexible touch displays, flexible solar cells, RFIDs, and 3D devices.While the pen itself is an ordinary commercial pen, the ink consists of a combination of electrically conductive carbon nanotube fibers and a viscous polymer solution called polyethylene oxide (PEO). The viscous PEO is highly elastic and mechanically strong, which allows it to pull long nanotube fibers from the solution during the writing process. “The drawing technique allow us to achieve very long carbon nanotube fibers mainly due to the high molecular weight of the polymer and high viscosity of the precursor solution as ink,” coauthor Hui Wu, Associate Professor at Tsinghua University, told Phys.org. Explore furtherlast_img read more

    READ MORE
  • Former US Census director Texas demographer available to comment on poverty report

    first_imgAddThis ShareDavid Ruth713-348-6327druth@rice.eduAmy Hodges713-348-6777amy.hodges@rice.edu Former US Census director, Texas demographer available to comment on poverty reportA new U.S. Census report shows that poverty in the United States is at its worst in 52 years and that Texas is even poorer compared to the rest of the nation.Steve Murdock, professor of sociology at Rice University, has seen the data and is available for media interviews to discuss the new report.Murdock previously served as the first official state demographer of Texas and directed the U.S. Census from 2007 to 2009. He is known for his work in assessing the effects of demographic change on socioeconomic change and in assessing the impacts of large-scale developments on the economic, demographic, public service, fiscal and social/cultural dimensions of small population areas.Murdock is currently traveling, so he is available for phone interviews only until this weekend, when he can do on-camera television interviews.To schedule an interview with Murdock, contact David Ruth at druth@rice.edu or 713-348-6327. last_img read more

    READ MORE