Thermodynamic equilibrium and its stability for Microcanonical systems described by the Sharma-Taneja-Mittal entropy

It is generally assumed that the thermodynamic stability of equilibrium state is reflected by the concavity of entropy. We inquire, in the microcanonical picture, on the validity of this statement for systems described by the bi-parametric entropy $S_{_{\kappa, r}}$ of Sharma-Taneja-Mittal. We analyze the ``composability'' rule for two statistically independent systems, A and B, described by the entropy $S_{_{\kappa, r}}$ with the same set of the deformed parameters. It is shown that, in spite of the concavity of the entropy, the ``composability'' rule modifies the thermodynamic stability conditions of the equilibrium state. Depending on the values assumed by the deformed parameters, when the relation $S_{_{\kappa, r}}({\rm A}\cup{\rm B})> S_{_{\kappa, r}}({\rm A})+S_{_{\kappa, r}}({\rm B})$ holds (super-additive systems), the concavity conditions does imply the thermodynamics stability. Otherwise, when the relation $S_{_{\kappa, r}}({\rm A}\cup{\rm B})<S_{_{\kappa, r}}({\rm A})+S_{_{\kappa, r}}({\rm B})$ holds (sub-additive systems), the concavity conditions does not imply the thermodynamical stability of the equilibrium state.Comment: 13 pages, two columns, 1 figure, RevTex4, version accepted on PR

Distortional Buckling Formulae for Thin Walled Channel and Z-sections with Return Lips

Cold-formed Channel- and Z-sections subject to both flexure and torsion may undergo distortional buckling where the flange and lip rotate about the flange/web junction. This mode of failure is prevalent in purlin sections when lateral deformation of the section is prevented and when the sections are manufactured from high strength steel. In an attempt to prevent distortional buckling, some manufacturers have added additional return lips to the flange lips to produce complex edge stiffeners. The Australian/New Zealand Standard for Cold-Formed Steel Structures includes design rules for determining the distortional buckling strength of cold-formed beam and column sections. These design rules require the computation of the elastic distortional buckling stress. Appendix D of ASINZS 4600 provides design rules for computing the elastic distortional buckling stress of general channels in compression, simple lipped channels in compression and simple lipped Channel- and Z-sections in bending about an axis perpendicular to the web. The paper describes general formulations for computing the elastic distortional buckling stresses of sections with return lips including those with sloping lips and return lips. The accuracy of the formulations is compared with the results for a large range of section geometries using a finite strip buckling analysis which can be regarded as providing accurate solutions for distortional buckling stress. Explicit expressions are presented in the paper for the flange properties

Interdisciplinary Study of Combating Hybrid Threats

NPS NRP Project PosterOur nation and allies are coming under increased attack by states and non-state actors who seek to exploit our vulnerabilities through employ non-attributable actions below the threshold of war in order to weaken our competitive advantage across all domains, steal intellectual property, or undermine the cohesiveness of our alliances. These hybrid threats can be in the form of hacking networks, cyber-attacks against critical infrastructure, disinformation campaigns, electoral interference, etc. These unconventional actions cannot be responsibly answered with conventional military forces and thus require a new set of response options. This research seeks to answer three broad questions on hybrid threats: what are the current hybrid threat challenges, how should we respond, and what do we need in order to execute such a response? The answers to these questions will achieve the main objectives of this research. First, arrive at a common understanding on the concept of hybrid threats. Second, develop an analytical framework to support designing actions to address and combat hybrid threats. Lastly, identify key issues and capability gaps for further research. The research methodology will begin with understanding the current depth of knowledge on hybrid threats, then developing case states to expand this knowledge, and lastly developing an analytical framework to combat hybrid threats. The analytical framework will help assess the actor, domain(s), methods, and desired intentions and objectives.N7 - Warfighting DevelopmentThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

Treatment-based classification of low back pain – who are the unclear classifications?

A recent focus in low back pain research has been to identify patient subgroups that respond best to certain treatments. To integrate these subgroup findings into a useable form, a treatment-based classification algorithm for LBP was created.1,2 To allow the algorithm to be comprehensive – eg, provide a classification for all patients – additional criteria are provided to assist therapists’ decisions for patients who do not clearly meet a treatment subgroup (unclear classifications). Recent research found that approximately 34% of patients will receive unclear classifications using the algorithm.3 It has also been shown that the reliability of the classification decision for unclear classifications is poor – significant variability between raters exists.3 In addition to poor reliability, outcomes for patients receiving unclear classifications may be inferior to outcomes of those receiving clear classifications.4 Thus the aim of the present study was to determine if people receiving unclear classifications are different from those with clear classifications in the hopes to refine the classification algorithm

Interdisciplinary Study of Combating Hybrid Threats

NPS NRP Executive SummaryOur nation and allies are coming under increased attack by states and non-state actors who seek to exploit our vulnerabilities through employ non-attributable actions below the threshold of war in order to weaken our competitive advantage across all domains, steal intellectual property, or undermine the cohesiveness of our alliances. These hybrid threats can be in the form of hacking networks, cyber-attacks against critical infrastructure, disinformation campaigns, electoral interference, etc. These unconventional actions cannot be responsibly answered with conventional military forces and thus require a new set of response options. This research seeks to answer three broad questions on hybrid threats: what are the current hybrid threat challenges, how should we respond, and what do we need in order to execute such a response? The answers to these questions will achieve the main objectives of this research. First, arrive at a common understanding on the concept of hybrid threats. Second, develop an analytical framework to support designing actions to address and combat hybrid threats. Lastly, identify key issues and capability gaps for further research. The research methodology will begin with understanding the current depth of knowledge on hybrid threats, then developing case states to expand this knowledge, and lastly developing an analytical framework to combat hybrid threats. The analytical framework will help assess the actor, domain(s), methods, and desired intentions and objectives.N7 - Warfighting DevelopmentThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

Electron Cloud Mitigation by Fast Bunch Compression in the CERN PS

A fast transverse instability has been observed with nominal LHC beams in the CERN Proton Synchrotron (PS) in 2006. The instability develops within less than 1 ms, starting when the bunch length decreases below a threshold of 11.5 ns during the RF procedure to shorten the bunches immediately prior to extraction. An alternative longitudinal beam manipulation, double bunch rotation, has been proposed to compress the bunches from 14 ns to the 4 ns required at extraction within 0.9 ms, saving some 4.5 ms with respect to the present compression scheme. The resultant bunch length is found to be equivalent for both schemes. In addition, electron cloud and vacuum measurements confirm that the development of an electron cloud and the onset of an associated fast pressure rise are delayed with the new compression scheme. Beam dynamics simulations and measurements of the double bunch rotation are presented as well as evidence for its beneficial effect from the electron cloud standpoint

A Candidate Protoplanet in the Taurus Star Forming Region

HST/NICMOS images of the class I protostar TMR-1 (IRAS04361+2547) reveal a faint companion with 10.0" = 1400 AU projected separation. The central protostar is itself resolved as a close binary with 0.31" = 42 AU separation, surrounded by circumstellar reflection nebulosity. A long narrow filament seems to connect the protobinary to the faint companion TMR-1C, suggesting a physical association. If the sources are physically related then we hypothesize that TMR-1C has been ejected by the protobinary. If TMR-1C has the same age and distance as the protobinary then current models indicate its flux is consistent with a young giant planet of several Jovian masses.Comment: 16 pages, 1 figure, Accepted by Astrophysical Journal Letters, Related information is available at http://www.extrasolar.co

Evidence for core-hole-mediated inelastic x-ray scattering from metallic Fe1.087_{1.087}Te

We present a detailed analysis of resonant inelastic scattering (RIXS) from Fe$_{1.087}$Te with unprecedented energy resolution. In contrast to the sharp peaks typically seen in insulating systems at the transition metal $L_3$ edge, we observe spectra which show different characteristic features. For low energy transfer, we experimentally observe theoretically predicted many-body effects of resonant Raman scattering from a non-interacting gas of fermions. Furthermore, we find that limitations to this many-body electron-only theory are realized at high Raman shift, where an exponential lineshape reveals an energy scale not present in these considerations. This regime, identified as emission, requires considerations of lattice degrees of freedom to understand the lineshape. We argue that both observations are intrinsic general features of many-body physics of metals.Comment: 4 pages, 4 figure

Quantum Mechanics Another Way

Deformation quantization (sometimes called phase-space quantization) is a formulation of quantum mechanics that is not usually taught to undergraduates. It is formally quite similar to classical mechanics: ordinary functions on phase space take the place of operators, but the functions are multiplied in an exotic way, using the star product. Here we attempt a brief, pedagogical discussion of deformation quantization, that is suitable for inclusion in an undergraduate course.Comment: 14 pages, 3 figures, to be published in Eur. J. Phy