6,061 research outputs found

    Parameter Identification of a Surface-to-Surface Missile from Flight Test Data

    Get PDF
    This document is a detailed project proposal for estimation of aerodynamic derivatives,fuel slosh parameters and flexible: body characteristics of a surface-to-surface missile from flight test data

    Environmental Risk Analysis: Problems and Perspectives in Different Countries

    Get PDF
    The authors discuss various industrial accidents, which have led to growing concerns about the potential hazards and risks involved in chemical process industries

    Privatisation in China: softly, softly does it

    Get PDF
    India’s halting attempts at privatisation and its preference, for the most part, for disinvestment have been roundly criticised by many as being inadequate. A more aggressive privatisation drive, it is contended, would make for superior economic performance. In popular discourse, China’s privatisation efforts are often compared favourably with India’s. This paper examines China’s record of privatisation to see whether it accords with popular perceptions. The record shows that China has been proceeded cautiously in its privatisation efforts. It has privatised – that is, sold off to private owners- only the smaller SOEs. The state retains control over the larger SOEs that dominate industrial output and profits. In respect of these, China has opted for gradual disinvestment with disinvested shares residing mostly with state-owned entities. Over a long period, China has pushed through reforms of SOEs, including conferment of greater autonomy on enterprises and introduction of incentives for workers and managers. The empirical evidence is that performance at SOEs has improved consequent to these reforms. It could be argued that full-blooded privatisation might have produced even better results. However, given the possible implications in terms of job losses as well as the absence of effective governance mechanisms in China’s underdeveloped capital market. China’s rulers may well have been justified in hastening slowly with privatisation.

    Love v. Virginia: The Constitutionality of the Marshall/Newman Amendment

    Get PDF
    My comment explores the constitutionality of a recent amendment in Virginia, the Marshall/Newman Amendment, which bans gay marriage and civil unions between unmarried people, and precludes Virginia from recognizing such arrangements formed in other states. The analysis is particularly timely, because even though the Democrats have regained a majority in Congress, and a traditionally Republican Virginian constituency just elected a Democratic senator, a majority of Virginians adopted this Amendment, indicating conservative values still reign. The comment argues that the Amendment is demonstrably inconsistent with the mandates of the Fourteenth Amendment of the Federal Constitution. The first provision seeks to ban same-sex marriage, restricting individuals’ right to marry and violating the Due Process Clause. The second provision attacks all nontraditional unions, contravening the Due Process Clause as well as Equal Protection under the 14th Amendment

    Internal noise driven generalized Langevin equation from a nonlocal continuum model

    Full text link
    Starting with a micropolar formulation, known to account for nonlocal microstructural effects at the continuum level, a generalized Langevin equation (GLE) for a particle, describing the predominant motion of a localized region through a single displacement degree-of-freedom (DOF), is derived. The GLE features a memory dependent multiplicative or internal noise, which appears upon recognising that the micro-rotation variables possess randomness owing to an uncertainty principle. Unlike its classical version, the new GLE qualitatively reproduces the experimentally measured fluctuations in the steady-state mean square displacement of scattering centers in a polyvinyl alcohol slab. The origin of the fluctuations is traced to nonlocal spatial interactions within the continuum. A constraint equation, similar to a fluctuation dissipation theorem (FDT), is shown to statistically relate the internal noise to the other parameters in the GLE

    Plasma Nitriding of 90CrMoV8 Tool Steel for the Enhancement of Hardness and Corrosion Resistance

    Get PDF
    The aim of the study is to apply a plasma nitriding process to the 90CrMoV8 steel commonly employed in wood machining, and to determine its efficiency to improve both mechanical and electrochemical properties of the surface. Treatments were performed at a constant N2:H2 gas mixture and by varying the temperature and process duration. The structural and morphological properties of nitrided layers were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with EDS microanalyses. Surface hardening and hardness profiles were evaluated by micro hardness measurements. To simulate the woodmachining conditions, electrochemical tests were carried out with an oak wood electrolyte with the purpose of understanding the effects of the nitriding treatment on the corrosion resistance of the tool in operation. X-ray diffraction analyses revealed the presence of both γ′ (Fe4N) and ε (Fe2–3N) nitrides with a predominance of the ε phase. Moreover, α-Fe (110), γ′ and ε diffraction peaks were shifted to lower angles suggesting the development of compressive stresses in the post nitrided steel. As a result, it was shown that nitriding allowed a significant hardening of steel with hardness values higher than 1200 HV. The diffusion layers were always composed of an outer compound layer and a hardened bulk layer which thickness was half of the total diffusion layer one.No white layer was observed. Similarly, no traces of chromium nitrides were detected. The temperature seemed to be a parameter more influent than the process duration on the morphological properties of the nitrided layer, while it had no real influence on their crystallinity. Finally, the optimal nitriding conditions to obtain a thick and hard diffusion layer are 500 °C for 10 h. On the other hand, to verify the effect of these parameters on the corrosion resistance, potentiodynamic polarization tests were carried out in an original “wood juice” electrolyte. After corrosion, surface was then observed at the SEM scale. Electrochemical study indicated that the untreated steel behaved as a passive material. Although the very noble character of steel was somewhat mitigated and the corrosion propensity increased for nitrided steels, the passive-like nature of themodified surfacewas preserved. For the same optimized parameters as those deduced from the mechanical characterization (500 °C, 10 h), surface presented, in addition to a huge surface hardening, a high corrosion resistance.Regional Council of Burgundy and EGID

    Exploration of The Duality Between Generalized Geometry and Extraordinary Magnetoresistance

    Full text link
    We outline the duality between the extraordinary magnetoresistance (EMR), observed in semiconductor-metal hybrids, and non-symmetric gravity coupled to a diffusive U(1)U(1) gauge field. The corresponding gravity theory may be interpreted as the generalized complex geometry of the semi-direct product of the symmetric metric and the antisymmetric Kalb-Ramond field: (gμν+βμνg_{\mu\nu}+\beta_{\mu\nu}). We construct the four dimensional covariant field theory and compute the resulting equations of motion. The equations encode the most general form of EMR within a well defined variational principle, for specific lower dimensional embedded geometric scenarios. Our formalism also reveals the emergence of additional diffusive pseudo currents for a completely dynamic field theory of EMR. The proposed equations of motion now include terms that induce geometrical deformations in the device geometry in order to optimize the EMR. This bottom-up dual description between EMR and generalized geometry/gravity lends itself to a deeper insight into the EMR effect with the promise of potentially new physical phenomena and properties.Comment: 13 pages and 6 figures. Revised/edited for clarity and purpose. Several references added. Updated title based on suggestions and comments received. Version accepted for publication in Phys.Rev.
    corecore