In This Issue
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The ALS has been working to adapt Berkeley Lab-wide policies regarding the use of personal protective equipment (PPE) in laboratory areas for application to the ALS’s unique experimental areas. The result is a three-part approach that designates certain technical areas and/or activities for which various forms of PPE are required.
Red Floor. The first technical area consists of all parts of the ALS experiment hall where the floor is painted red. This encompasses essentially all space under the dome in the facility, including the beamlines, accelerator tunnels, and pit areas. The PPE requirements for this area are closed-toe shoes and long pants or equivalent. Note that the nonpainted perimeter walkway and the designated pedestrian walkway used for tours are not covered by this requirement.
Yellow Border. In addition to the above requirement, within the experiment hall, certain smaller, limited areas exist where chemical and/or biological materials are used or stored. This also includes areas where open containers of liquid nitrogen may be found. These areas are identified by floor mats with a yellow border. All individuals who enter these areas (i.e., step on the floor mats) must wear proper eye protection (typically safety glasses) in addition to the closed-toe shoes and long pants.
Liquid Nitrogen. Finally, when pressurized liquid nitrogen cylinders are being manipulated, an environmental hazard to the eyes exists. Regardless of where this work occurs, anyone within a radius of 3 ft must wear safety glasses. This is reinforced with signage at the cylinders. Note that this environmental hazard does not exist when the cylinders are not being manipulated, and safety glasses are not required just to walk past a stored gas cylinder (such as exists at many loading docks, etc.).
Graphene is the two-dimensional crystalline form of carbon whose extraordinary electron mobility and other unique features hold great promise for nanoscale electronics and photonics. But without a bandgap, graphene’s promise can’t be realized. As with monolayer graphene, bilayer graphene also has a zero bandgap and thus behaves like a metal. But a bandgap can be introduced if an electric displacement field is applied to the two layers; the material then behaves like a semiconductor. A team of researchers from Berkeley has engineered a bandgap in bilayer graphene that can be precisely controlled from 0 to 250 meV. With precision control of its bandgap over a wide range, plus independent manipulation of its electronic states through electrical doping, dual-gated bilayer graphene becomes a remarkably flexible tool for nanoscale electronic devices.
Publication about this research: Y. Zhang, T.-T. Tang, C. Girit, Z. Hao, M.C. Martin, A. Zettl, M.F. Crommie, Y.R. Shen, and F. Wang, “Direct observation of a widely tunable bandgap in bilayer graphene,” Nature 459, 820 (2009).
Rotaxanes are mechanically interlocked molecular architectures consisting of a dumbbell-shaped molecule, the “axle,” that threads through a ring called a macrocycle. Because the rings can spin around and slide along the axle, rotaxanes are promising components of molecular machines. While most rotaxanes have been entirely organic, the physical properties desirable in molecular machines are mostly found in inorganic compounds. Working together, two British groups at the University of Edinburgh and the University of Manchester have bridged this gap with hybrid rotaxanes, in which inorganic rings encircle the organic axles. The hybrid architecture greatly increases their range of useful physical properties, such as the magnetism based on molecular magnets that may make them suitable as qubits for quantum computers. Read more…
Publication about this research: C.-F. Lee, D.A. Leigh, R.G. Pritchard, D. Schultz, S.J. Teat, G.A. Timco, and R.E.P. Winpenny, “Hybrid organic-inorganic rotaxanes and molecular shuttles,” Nature 458, 314 (2009).
ALS USERS’ MEETING: The 16th annual ALS Users’ Meeting is October 15–17, 2009. This year’s meeting will be held jointly with The Molecular Foundry with a joint plenary, workshops, poster session, and banquet.
9/25: Early-registration deadline
SPEAKERS: With an energy focus, this year’s plenary speakers are: Bill Brinkman, Harriet Kung, and Arun Majumdar. Scientific highlights speakers are Pupa Gilbert (nacre), Mark LeGros (bio-fuels), and two speakers from The Molecular Foundry (TBD).
AWARDS: Nominations for the Shirley (Science), Halbach (Instrumentation), and Renner (Service) awards will be accepted until Monday, August 31, 2009. Nominators fill out a simple form, available at the awards link above.
POSTERS: The deadline for poster abstract submissions is also Monday, August 31, 2009. Students submitting posters will compete for three awards, with the winner being given an opportunity to speak at the Friday morning session.
UEC ELECTIONS : The ALS Users’ Executive Committee will be electing three new members and one student representative this fall. Nominations will be accepted until October 15, 2009, and voting will begin on October 16, 2009, on the second day of the meeting. Nomination instructions are available at the ALS UEC Web site, above.
We’re looking forward to seeing you at the meeting!
The Guest House at Berkeley Lab plans to open its doors to users from October 1, 2009, and will be taking individual reservations from September 1. The Guest House can be contacted by email. Inquiries sent before September 1 will receive an automatic response with information about booking, and the potential guest will be contacted after September 1.
Requests for a booking should include the following information:
The ALS kicks off its Science Cafe series tomorrow in Room 2-100B at 12 noon. The Science Cafe, designed to give beamline scientists the opportunity to present recent work to the ALS community in an informal environment, will start with a focus on energy research and technology. Featured this month is current work by staff and users on bioenergy, CO2 sequestration, and advances in solar-cell research. All are invited to attend and participate.
How do you explain the science at the ALS to those without a science background? Emma Floyd, an undergraduate journalism student, created two videos to try and answer that question. “What is the Advanced Light Source?” gives a brief look at what the ALS is, who uses it, and how it works. In “The Big, The Small, and The ALS,” viewers get an idea of the scale of the science done at the ALS with a quick look at some of the incredible numbers and measurements scientists use daily.
Have you ever wanted to ask a scientist to define a term in lay language? The Berkeley Lab Public Affairs Department thought so, which is why—with the help of scientists all over Berkeley Lab, including the ALS community—they have put together a video glossary , prominently featured on the Lab’s homepage. Among the terms defined are photons (Ben Feinberg), synchrotron radiation (Mike Martin), protein crystallography (Corie Ralston), surface science (Miquel Salmeron), and free-electron laser (John Corlett). Entries are added each week, some of which are prompted by viewer suggestions.
For the user runs from July 14 to August 17, the beam reliability [(time scheduled – time lost)/time scheduled)] was 97.2%. For this period, the mean time between failures (MTBF) was 33.5 hours, and the mean time to recovery (MTTR) was 56 minutes. There were no significant interruptions. (This period includes two-bunch operations from August 5–16.)
During this period, a new record was set for continuous hours of light provided to users in a single week of operation. For the period from July 14–19, 120 continuous hours of light were provided to users in top-off mode without any interruptions.
More detailed information on reliability is available on the ALS reliability bulletin board, which is located in the hallway between the ALS and the control room in Building 80. Questions about beam reliability should be directed to David Richardson (x4376 ).
Long-term and weekly operations schedules are available here. Requests for special operations use of the “scrubbing” shift should be sent to Rick Bloemhard (ALS-CR@lbl.gov, x4738) by 1:00 p.m. Friday. View the ring status in real time here.