1,761 research outputs found

    A Worst Practices Guide to Insider Threats: Lessons from Past Mistakes

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    Insider threats are perhaps the most serious challenges that nuclear security systems face. All of the cases of theft of nuclear materials where the circumstances of the theft are known were perpetrated either by insiders or with the help of insiders; given that the other cases involve bulk material stolen covertly without anyone being aware the material was missing, there is every reason to believe that they were perpetrated by insiders as well. Similarly, disgruntled workers from inside nuclear facilities have perpetrated many of the known incidents of nuclear sabotage. The most recent example of which we are aware is the apparent insider sabotage of a diesel generator at the San Onofre nuclear plant in the United States in 2012; the most spectacular was an incident three decades ago in which an insider placed explosives directly on the steel pressure vessel head of a nuclear reactor and then detonated them.While many such incidents, including the two just mentioned, appear to have been intended to send a message to management, not to spread radioactivity, they highlight the immense dangers that could arise from insiders with more malevolent intent. As it turns out, insiders perpetrate a large fraction of thefts from heavily guarded non-nuclear facilities as well. Yet organizations often find it difficult to understandand protect against insider threats. Why is this the case?Part of the answer is that there are deep organizational and cognitive biases that lead managers to downplay the threats insiders pose to their nuclear facilities and operations. But another part of the answer is that those managing nuclear security often have limited information about incidents that have happened in other countries or in other industries, and the lessons that might be learned from them.The IAEA and the World Institute for Nuclear Security (WINS) produce"best practices" guides as a way of disseminating ideas and procedures that have been identified as leading to improved security. Both have produced guides on protecting against insider threats.5 But sometimes mistakes are even moreinstructive than successes.Here, we are presenting a kind of "worst practices" guide of serious mistakes made in the past regarding insider threats. While each situation is unique, and serious insider problems are relatively rare, the incidents we describe reflect issues that exist in many contexts and that every nuclear security manager should consider. Common organizational practices -- such as prioritizing production over security, failure to share information across subunits, inadequate rules or inappropriate waiving of rules, exaggerated faith in group loyalty, and excessive focus on external threats -- can be seen in many past failures to protect against insider threats

    Evaporation of ice in planetary atmospheres: Ice-covered rivers on Mars

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    The evaporation rate of water ice on the surface of a planet with an atmosphere involves an equilibrium between solar heating and radiative and evaporative cooling of the ice layer. The thickness of the ice is governed principally by the solar flux which penetrates the ice layer and then is conducted back to the surface. Evaporation from the surface is governed by wind and free convection. In the absence of wind, eddy diffusion is caused by the lower density of water vapor in comparison to the density of the Martian atmosphere. For mean martian insolations, the evaporation rate above the ice is approximately 10 to the minus 8th power gm/sq cm/s. Evaporation rates are calculated for a wide range of frictional velocities, atmospheric pressures, and insolations and it seems clear that at least some subset of observed Martian channels may have formed as ice-chocked rivers. Typical equilibrium thicknesses of such ice covers are approximately 10m to 30 m; typical surface temperatures are 210 to 235 K

    Goethite on Mars - A laboratory study of physically and chemically bound water in ferric oxides

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    Thermogravimetric study of physically and chemically bound water in ferric oxides of limonite with application to goethite on Mar

    Measurement and Compensation of Horizontal Crabbing at the Cornell Electron Storage Ring Test Accelerator

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    In storage rings, horizontal dispersion in the rf cavities introduces horizontal-longitudinal (xz) coupling, contributing to beam tilt in the xz plane. This coupling can be characterized by a "crabbing" dispersion term {\zeta}a that appears in the normal mode decomposition of the 1-turn transfer matrix. {\zeta}a is proportional to the rf cavity voltage and the horizontal dispersion in the cavity. We report experiments at the Cornell Electron Storage Ring Test Accelerator (CesrTA) where xz coupling was explored using three lattices with distinct crabbing properties. We characterize the xz coupling for each case by measuring the horizontal projection of the beam with a beam size monitor. The three lattice configurations correspond to a) 16 mrad xz tilt at the beam size monitor source point, b) compensation of the {\zeta}a introduced by one of two pairs of RF cavities with the second, and c) zero dispersion in RF cavities, eliminating {\zeta}a entirely. Additionally, intrabeam scattering (IBS) is evident in our measurements of beam size vs. rf voltage.Comment: 5 figures, 10 page

    Shared Responsibilities for Nuclear Disarmament: A Global Debate

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    Presents Sagan's 2009 paper calling for rethinking the balance of responsibilities and the relationship between articles in the Nuclear Non-Proliferation Treaty with seven response papers by international scholars about how to pursue nuclear disarmament

    Life on ice, Antarctica and Mars

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    The study of the origin of life and the prospects for human exploration of Mars are two themes developed in a new 57-minute film, Life on Ice, Antarctica, and Mars, produced by the InnerSpace Foundation and WHRO Television for broadcast by the Public Broadcasting System (PBS). A brief explanation of the film and how it relates to the future human exploration of space is presented

    Separation of colour degree of freedom from dynamics in a soliton cellular automaton

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    We present an algorithm to reduce the coloured box-ball system, a one dimensional integrable cellular automaton described by motions of several colour (kind) of balls, into a simpler monochrome system. This algorithm extracts the colour degree of freedom of the automaton as a word which turns out to be a conserved quantity of this dynamical system. It is based on the theory of crystal basis and in particular on the tensor products of sl_n crystals of symmetric and anti-symmetric tensor representations.Comment: 19 page
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