4,549 research outputs found

    Electromagnetic dipole moments of charged baryons with bent crystals at the LHC

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    We propose a unique program of measurements of electric and magnetic dipole moments of charm, beauty and strange charged baryons at the LHC, based on the phenomenon of spin precession of channeled particles in bent crystals. Studies of crystal channeling and spin precession of positively- and negatively-charged particles are presented, along with feasibility studies and expected sensitivities for the proposed experiment using a layout based on the LHCb detector.Comment: 19 pages, 13 figure

    Modelling of thermo-chemical properties over the sub-solidus MgO–FeO binary, as a function of iron spin configuration, composition and temperature

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    Thermo-chemical properties and T–X phase relations diagram of the (Mg,Fe)O solid solution are modelled using mixing Helmholtz energy, ΔF(T,x)mixing, calculated by quantum mechanical and semi-empirical techniques. The sub-solidus MgO–FeO binary has been explored as a function of composition, with iron either in high-spin (HS) or low-spin (LS) configuration. Only the HS model provides physically sound results at room pressure, yielding a correct trend of cell edge versus composition, whereas LS’s issues are at variance with observations. Mixing Helmholtz energy has been parametrized by the following relationship: ΔF(T,x)mixing = x × y × [U0(T) + U1(T) × (x – y) + U2(T) × (x − y)2]−T × S(x,y)config, where y = 1−x and Uj(T) are polynomials in T of the second order. ΔF(T,x)mixing exhibits a quasi-symmetric behaviour and allows one to build the T–X phase relations diagram over the MgO–FeO join. The HS model including vibrational contribution to the Helmholtz energy predicts a solid solution’s critical temperature of some 950 K, remarkably larger than olivine’s and Mg–Fe garnet’s. All this points to a more difficult Mg–Fe mixing in periclase-like structure than olivine and garnet, which, in turn, provide more structure degrees of freedom for atomic relaxation. From ΔF(T,x)mixing, we have then derived ΔH(T,x)excess and ΔS(T,x)excess. The former, characterized by a quasi-regular behaviour, has been parametrized through W × x × (1−x), obtaining WH,Mg–Fe of 17.7(5) kJ/mol. ΔS(T,x)excess, in turn, increases as a function of temperature, showing absolute figures confined within 0.1 J/mol/K. Mixing Gibbs energy, calculated combining the present issues with earlier theoretical determinations of the magnesio-wüstite’s elastic properties, has shown that the HS configuration is stable and promote Mg–Fe solid solution up to ≈15 GPa

    Efficient Passive ICS Device Discovery and Identification by MAC Address Correlation

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    Owing to a growing number of attacks, the assessment of Industrial Control Systems (ICSs) has gained in importance. An integral part of an assessment is the creation of a detailed inventory of all connected devices, enabling vulnerability evaluations. For this purpose, scans of networks are crucial. Active scanning, which generates irregular traffic, is a method to get an overview of connected and active devices. Since such additional traffic may lead to an unexpected behavior of devices, active scanning methods should be avoided in critical infrastructure networks. In such cases, passive network monitoring offers an alternative, which is often used in conjunction with complex deep-packet inspection techniques. There are very few publications on lightweight passive scanning methodologies for industrial networks. In this paper, we propose a lightweight passive network monitoring technique using an efficient Media Access Control (MAC) address-based identification of industrial devices. Based on an incomplete set of known MAC address to device associations, the presented method can guess correct device and vendor information. Proving the feasibility of the method, an implementation is also introduced and evaluated regarding its efficiency. The feasibility of predicting a specific device/vendor combination is demonstrated by having similar devices in the database. In our ICS testbed, we reached a host discovery rate of 100% at an identification rate of more than 66%, outperforming the results of existing tools.Comment: http://dx.doi.org/10.14236/ewic/ICS2018.

    Fe-periclase reactivity at Earth's lower mantle conditions: Ab-initio geochemical modelling

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    Intrinsic and extrinsic stability of the (Mg,Fe)O solid mixture in the Fe-Mg-Si-O system at high P, T conditions relevant to the Earth\u2019s mantle is investigated by the combination of quantum mechanical calculations (Hartree- 26 Fock/DFT hybrid scheme), cluster expansion techniques and statistical thermodynamics. Iron in the (Mg,Fe)O binary mixture is assumed to be either in the low spin (LS) or in the high spin (HS) state. Un-mixing at solid state is observed only for the LS condition in the 23\u201342 GPa pressure range, whereas HS does not give rise to un-mixing. LS (Mg,Fe)O un-mixings are shown to be able to incorporate iron by subsolidus reactions with a reservoir of a virtual bridgmanite composition, for a maximum total enrichment of 0.22 FeO. At very high P (up to 130/3150 GPa/K), a predominant (0.7 phase proportion), iron-rich Fe-periclase mixture (Mg0.50Fe0.50)O is formed, and it coexists, at constrained phase composition conditions, with two iron-poor assemblages [(Mg0.90Fe0.10)O and (Mg0.825Fe0.175)O]. These theoretical results agree with the compositional variability and frequency of occurrence observed in lower mantle Fe-periclase from diamond inclusions and from HP-HT synthesis products. The density difference among the Fe-periclase phases increases up to 10%, between 24 and 130 GPa. The calculated bulk Fe/Mg partitioning coefficient between the bridgmanite reservoir and Fe-periclase, Kd, is 0.64 at 24 GPa; it then drops to 0.19 at 80 GPa, and becomes quasi-invariant (0.18\u20130.16) in the lowermost portion of the Earth\u2019s mantle (80\u2013 130 GPa). These Kd-values represent an approximate estimate for the Fe/Mg-partitioning between actual bridgmanite and Fe-periclase. Consequently, our Kd-values agree with experimental measurements and theoretical determinations, hinting that iron preferentially dissolves in periclase with respect to all the other iron-bearing phases of the lower mantle. The continuous change up to 80 GPa (2000 km depth) of the products (compositions and phase proportions) over the MgO-FeO binary causes geochemical heterogeneities throughout the lower mantle, but it does not give rise to any sharp discontinuity. In this view, anomalies like the ULVZs, explained with a local and abrupt change of density, do not seem primarily ascribable to the mixing behavior and reactivity of (Mg,Fe)O at subsolidus

    In situ analysis of garnet inclusion in diamond using single-crystal X-ray diffraction and X-ray micro-tomography

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    none9A single crystal of garnet enclosed in a diamond from the Jericho kimberlite (Slave Craton, Canada) has been investigated using X-ray diffraction and X-ray micro-tomography. The novel experimental approach allowed us to determine the crystal structure of the garnet. The unit-cell edge a and fractional atomic coordinates of oxygen were used to determine the composition via an updated Margules model for garnets. The composition is Pyr(0.41(5))Alm(0.36(7))Gro(0.22(1))Uva(0.01(1)), which is indistinguishable from the eclogitic garnets found in other Jericho diamonds. We also demonstrated that residual pressures on the inclusion of up to 1 GPa do not affect significantly the determination of the garnet composition by structure refinement.noneFABRIZIO NESTOLA;M. MERLI;PAOLO NIMIS;M. PARISATTO;M. KOPYLOVA;A. DE;M. LONGO;L. ZIBERNA;M. MANGHNANINestola, Fabrizio; M., Merli; Nimis, Paolo; Parisatto, Matteo; M., Kopylova; A., De; Longo, Micaela; Ziberna, Luca; M., Manghnan

    Rituximab in combination with fludarabine and cyclophosphamide in the treatment of patients with recurrent follicular lymphoma

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    The current study was conducted to asses the safety profile and clinical activity of rituximab in combination with fludarabine and cyclophosphamide in patients with recurrent follicular lymphoma (FL). METHODS: This study was a noncomparative, multicenter, phase II study. Between March 2000 and December 2002, 54 patients with recurrent FL were enrolled in the FC+R trial. Patients received fludarabine at a dose of 25 mg/m(2) and cyclophosphamide at a dose of 300 mg/m(2) daily for 3 consecutive days, every 3 weeks for 4 cycles. Rituximab was administered at a dose of 375 mg/m(2) beginning 2 weeks after the first course of fludarabine and cyclophosphamide and then on Day 1 of each cycle thereafter. The planned treatment duration was 10 weeks. RESULTS: Overall, 92% of patients completed the planned therapy in 10 to 14 weeks and 74% achieved a complete response (CR). Among patients with BCL2-positive bone marrow, 86% obtained a molecular disease remission (MR). The median survival from treatment (SFT), the duration of disease remission (DR), and time to disease progression (TTP) had not been reached after a median follow-up of 45 months. Of the baseline characteristics, >2 previous treatments, BCL2-positive bone marrow, and low Follicular Lymphoma International Prognostic Index (FLIPI) score were found to be associated with better DR and/or TTP. Hematologic toxicity was transient and reversible, with the exception of 3 patients with severe and prolonged neutropenia. Three patients presented with infections, 1 of whom died of bronchopneumonia. CONCLUSIONS: The FC+R scheme, a nonanthracycline-containing regimen lasting up to 10 weeks, was found to be relatively well-tolerated and demonstrated significant antilymphoma activity with excellent clinical CR and molecular response rates

    Dopant profiling on ultra shallow junctions in Si with ADF-STEM

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    The utmost scaling of the electronic devices nowadays attained, requires both ultra shallow junctions and high levels of dopant concentration and activation. In these conditions, the presence of surfaces or interfaces assumes a very important role in the determination of the dopant distribution during post-implantation annealing. In this work, we show how the Z-contrast annular dark field scanning transmission electron microscopy (ADF-STEM) technique, pionereed by Pennycook and coworkers [1], can be optimised to give reliable dopant profiles at a subnanometer scale thus satisfying some of the new needs of the ultra shallow implants characterization

    Thromboembolism After Intramedullary Nailing for Metastatic Bone Lesions.

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    BACKGROUND: The risk of venous thromboembolism (VTE) in patients undergoing intramedullary nailing for skeletal metastatic disease is currently undefined. The purpose of our study was to determine the risk of thromboembolic events, to define the risk factors for VTE, and to define the rate of wound complications in this population. METHODS: A retrospective review of surgical databases at three National Cancer Institute (NCI)-designated cancer centers identified 287 patients with a total of 336 impending or pathologic long-bone fractures that were stabilized with intramedullary nailing between February 2001 and April 2013. Statistical analysis was performed utilizing multivariable logistic regression and Fisher exact tests. RESULTS: The overall rate of VTE was twenty-four (7.1%) of the 336; thirteen (3.9%) were pulmonary embolism (PE), and eleven (3.3%), deep venous thrombosis (DVT). In two patients, adequate anticoagulation data were not available. We found no significant relationship between the type of anticoagulant used and VTE. There was a significant positive correlation found between lung-cancer histology and the development of VTE (p \u3c 0.001) or PE (p \u3c 0.001). The absence of radiation therapy approached significance (p = 0.06) with respect to decreased overall VTE risk. Wound complications were documented for 11 (3.3%) of the operations. CONCLUSIONS: There is a high rate of VTE among those with skeletal metastatic disease who undergo intramedullary nailing, even while receiving postoperative thromboembolic prophylaxis. Current anticoagulation protocols may be inadequate. Wound-complication risk with anticoagulant use in this population is low and should not be a deterrent to adequate anticoagulant use for this population
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