SAN DIEGO (CNS) – Former San Diego city councilman Carl DeMaio announced Friday he has decided against a run for Congress in order to focus on a campaign that aims to roll back last year’s increase to the gas tax.DeMaio bowed out four days after pulling nomination papers to challenge incumbent fellow Republican Duncan Hunter in the 50th Congressional District.Candidates have until the end of the day Friday to turn in their papers.“While I, too, am frustrated with the lack of results and the double standards for Washington politicians, I believe the Gas Tax Repeal Initiative campaign and our plans for subsequent reform initiatives in California are so much more important,” DeMaio wrote in an email to supporters Friday afternoon.Hunter is facing challengers from both parties amid a federal investigation into whether the five-term GOP incumbent misused campaign funds.The field includes Democrats Patrick Malloy, Pierre Beauregard, Josh Butner and Ammar Campa-Najjar and Republicans Shamus Sayed and Bill Wells. Updated: 10:51 PM Former Councilman Carl DeMaio decides against running for Congress KUSI Newsroom KUSI Newsroom, Posted: March 9, 2018 March 9, 2018 Categories: Local San Diego News, Politics Tags: 50th Congressional District, Carl DeMaio, Duncan Hunter, Gas Tax Repeal Initiative FacebookTwitter
From 2-D to 1-D: atomically quasi ‘1-D’ wires using a carbon nanotube template (PhysOrg.com) — For the past several years, researchers have been trying to take advantage of carbon nanotubes’ good electrical properties for future nanoscale electronics applications. One of the biggest challenges in this area is finding ways to arrange and assemble the nanotubes into 3D configurations for carrying current in nanoscale devices. Most recently, a team of physicists and engineers from the Electronic Materials Research Institute at Northeastern University in Boston, Massachusetts, has demonstrated a technique for assembling nanotubes using an applied electric field. Using this method, the researchers could assemble single-walled carbon nanotubes into 3D structures by coaxing the nanotubes into deep nanoholes in a porous alumina template. An average of one nanotube per hole was vertically assembled, and, by sweeping the 0.32cm2 area, more than one million holes were filled with nanotubes.“The greatest significance of this technique is that it provides the potential to manufacture, at a high rate and on a large scale, three-dimensional single-wall carbon nanotube electrical interconnects, without the need for high-temperature synthesis,” Srinivas Sridhar, Director of the Electronic Materials Research Institute, told PhysOrg.com.To achieve this nanotube assembly, the researchers attached a positive electrode to the bottom of a silicon template, which the aluminum template went on top of. Then they manually swept a negative electrode over assembly sites, pushing negatively charged nanotubes into the holes in the aluminum template. This process of using an electric field to move charged objects is called electrophoresis. Similarly, a process called dielectrophoresis, in which a non-uniform electric field moves charged or uncharged objects, also assisted in orienting the nanotubes toward the holes.After assembling the nanotubes, the researchers sputtered a 15-nm-thick gold layer on top of the alumina template, touching the tops of the nanotubes. This layer completed an electrical connection between all the nanotubes reaching the surface of the template, with electric current traveling through the nanotubes between the gold and silicon layers. On control samples without nanotubes, no current was observed between the two layers, confirming that the nanotubes had carried the current.By not requiring high temperatures, and providing the ability to cover centimeter-scale areas in a short time, the new assembly technique has useful advantages over other nanotube assembly techniques. The method could also integrate well into existing silicon platforms, which could be used in microelectronics, field emission displays, electronic memory devices and solar cells.“The next step in nanoscale electronics is to integrate the 3D carbon nanotubes architectures with current CMOS technology and create hybrid systems,” Sridhar said. “The holy grail of nanoscale electronics is to completely replace CMOS technology by monolithic carbon nanotubes devices.“Scaling down the nominal feature size makes more space available on a chip to hold more transistors and other types of devices,” he added. “Shrinking process geometries means better performance and lower costs.”More information: Electronic Materials Research InstituteCitation: Gultepe, Evin; Nagesha, Dattatri; Casse, Bernard Didier Frederic; Selvarasah, Selvapraba; Busnaina, Ahmed; and Sridhar, Srinivas. “Large scale 3D vertical assembly of single-wall carbon nanotubes at ambient temperatures.” Nanotechnology 19 (2008) 455309 (5pp). Contact: s.sridhar(at)neu.eduCopyright 2008 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Explore further Citation: 3D nanotube assembly technique for nanoscale electronics (2008, October 22) retrieved 18 August 2019 from https://phys.org/news/2008-10-3d-nanotube-technique-nanoscale-electronics.html A cross-sectional view of the assembled carbon nanotubes and gold top layer in yellow (false color), taken by a scanning electron microscope. Image credit : Evin Gultepe, et al. 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.