Enhanced resistance of single-layer graphene to ion bombardment

We report that single-layer graphene on a SiO_2/Si substrate withstands ion bombardment up to ~7 times longer than expected when exposed to focused Ga^+ ion beam. The exposure is performed in a dual beam scanning electron microscope/focused ion beam system at 30 kV accelerating voltage and 41 pA current. Ga^+ ion flux is determined by sputtering a known volume of hydrogenated amorphous carbon film deposited via plasma-enhanced chemical vapor deposition

A Layman's guide to SUSY GUTs

The determination of the most straightforward evidence for the existence of the Superworld requires a guide for non-experts (especially experimental physicists) for them to make their own judgement on the value of such predictions. For this purpose we review the most basic results of Super-Grand unification in a simple and clear way. We focus the attention on two specific models and their predictions. These two models represent an example of a direct comparison between a traditional unified-theory and a string-inspired approach to the solution of the many open problems of the Standard Model. We emphasize that viable models must satisfy {\em all} available experimental constraints and be as simple as theoretically possible. The two well defined supergravity models, $SU(5)$ and $SU(5)\times U(1)$, can be described in terms of only a few parameters (five and three respectively) instead of the more than twenty needed in the MSSM model, \ie, the Minimal Supersymmetric extension of the Standard Model. A case of special interest is the strict no-scale $SU(5)\times U(1)$ supergravity where all predictions depend on only one parameter (plus the top-quark mass). A general consequence of these analyses is that supersymmetric particles can be at the verge of discovery, lurking around the corner at present and near future facilities. This review should help anyone distinguish between well motivated predictions and predictions based on arbitrary choices of parameters in undefined models.Comment: 25 pages, Latex, 11 figures (not included), CERN-TH.7077/93, CTP-TAMU-65/93. A complete ps file (1.31MB) with embedded figures is available by request from [email protected]

Social Security Disability Insurance, Medicare And Work: A Review of the SSDI and Medicare Rules Related to Work Activity. Guidelines for Proactively Using the SSDI and Medicare Work Incentives to Help Individuals with Disabilities Maximize Independence Through Work

This policy-to-practice brief will focus on issues related to benefits and work for the SSDI beneficiary. After first explaining what SSDI is and the differences between SSDI and SSI, we will explain two historical work disincentives: the substantial gainful activity (SGA) rule and the continuing disability review (CDR). We will then explore a number of work incentives or special rules that seek to encourage work by either allowing benefits to continue for limited periods while working (trial work period (TWP), extended period of eligibility (EPE)), or allow individuals to quickly return to benefits status when a work effort stops or wage levels dip below the SGA level (expedited reinstatement). We will also explain special rules for either ignoring some short-term employment efforts (unsuccessful work attempts) or reducing countable monthly wages to be measured against the SGA amount for the year in question (impairment related work expenses, subsidies, paid time off)

The Medicaid Buy-In for Working People With Disabilities: Individuals With Disabilities Can Earn Significant Wages and Qualify for This Important Health Care Benefit

This policy-to-practice brief provides an in-depth illustrated description of the Plan for Achieving Self-Support (PASS) work incentives. This brief reviews how the PASS can be used to promote a work goal; the criteria for approving a PASS; and how the PASS can be used in conjunction with other programs to promote and achieve vocational success. Throughout the brief, examples are used to illustrate principles and provide an example in the appendices to show how to propose a PASS that meets all of SSA’s criteria for approval. Extensive citations to law, regulation, and policy appear in footnotes to maximize the usefulness of this publication to benefits planners who are engaged in writing PASS proposals for individuals

Fe I line shifts in the optical spectrum of the Sun

New improvements in the measurement of both the optical solar spectrum and laboratory wavelengths for lines of neutral iron are combined to extract central wavelength shifts for 1446 lines observed in the Sun. This provides the largest available database of accurate solar wavelengths useful as a reference for comparison with other solar-type stars. It is shown how the velocity shifts correlate with line strength, approaching a constant value, close to zero, for lines with equivalent widths larger than 200 mA.Comment: Latex file (5 pages), uses l-aa.sty and epsfig.sty (included); 3 Postscript figures, 1 ASCII table, accepted for publication in Astronomy and Astrophysics Supplement Serie

Ultracold atoms at unitarity within quantum Monte Carlo

Variational and diffusion quantum Monte Carlo (VMC and DMC) calculations of the properties of the zero-temperature fermionic gas at unitarity are reported. The ratio of the energy of the interacting to the non-interacting gas for a system of 128 particles is calculated to be 0.4517(3) in VMC and 0.4339(1) in the more accurate DMC method. The spherically-averaged pair-correlation functions, momentum densities, and one-body density matrices are very similar in VMC and DMC, but the two-body density matrices and condensate fractions show some differences. Our best estimate of the condensate fraction of 0.51 is a little smaller than values from other quantum Monte Carlo calculations

WORKING: The Newsletter of the New York Makes Work Pay Initiative

WELCOME to the inaugural issue of Working, a print and elec¬tronic newsletter produced by the New York Makes Work Pay Initiative. This Initiative is a Comprehensive Employment Ser¬vices Medicaid Infrastructure Grant funded by the U.S. Department of Health and Human Services, Centers for Medicare and Medicaid Services (CMS) to the New York State Office of Mental Health (OMH) and its management partners the Burton Blatt Institute (BBI) at Syra¬cuse University and the Employment and Disability Institute (EDI) at Cornell University. The New York Makes Work Pay Initiative is currently funded for calendar years 2009 and 2010 and will provide an array of services to individuals with disabilities, the agencies and advocates that serve them, and employers, helping to remove obstacles to work and pave the way to self-supporting employment