2,263 research outputs found

    Inertial-Hall effect: the influence of rotation on the Hall conductivity

    Get PDF
    Inertial effects play an important role in classical mechanics but have been largely overlooked in quantum mechanics. Nevertheless, the analogy between inertial forces on mass particles and electromagnetic forces on charged particles is not new. In this paper, we consider a rotating non-interacting planar two-dimensional electron gas with a perpendicular uniform magnetic field and investigate the effects of the rotation in the Hall conductiv

    Adubação química de cultivares de pimenta-do-reino (Piper nigrum L.) em latossolo amarelo da rodovia Transamazônica.

    Get PDF
    bitstream/item/61692/1/Belem-ComTec1.pd

    Modeling the inactivation of Bacillus subtilis spores by ethylene oxide processing

    Get PDF
    Ethylene oxide is currently a dominant agent in medical device sterilization. This work intends to study the main effects and interactions of temperature, ethylene oxide concentration, and relative humidity on commercial spore strips of Bacillus subtilis, var. niger (ATCC 9372) inactivation, the most common microorganism used in controlling the efficacy of the process. Experiments were carried out using a full factorial experimental design at two levels (2(3) factorial design). Limit target exposure conditions for ethylene oxide concentration, temperature, and relative humidity were 250-1,000 mg EO/l, 40-60A degrees C, and 50-90%, respectively. Adopting a different approach from the first-order kinetics, a Gompertz model was successfully applied in data fitting of the inactivation curves. Bacillus subtilis kinetic behavior presented a sigmoidal inactivation with an initial shoulder (lambda), followed by a maximum inactivation rate (k(max)), these being model parameters. It was concluded that temperature and ethylene oxide concentration were the most significant factors and consequently, additional experiments were carried out aiming at describing the parameters' dependence on these process factors. Mathematical relations describing such dependences were successfully developed and included in the Gompertz kinetic model. The predictive ability of this integrated model was assessed, and its adequacy in predicting B. subtilis inactivation was proven.info:eu-repo/semantics/acceptedVersio

    Ethylene oxide sterilization of medical devices: a review

    Get PDF
    Ethylene oxide (EO) is a well-known sterilizing agent. However, only recently has its use significantly emerged, based on its range of applications in the field of new medical device development and sterilization. This paper describes the progress in terms of EO sterilization and concludes that it remains a promising field to explore and develop. The EO action mechanism and toxicity are analyzed, and a critical analysis is made on how it is possible to use EO sterilization for medical devices advantageously, with emphasis on cycle design and validation. One huge challenge is related with the development of mathematical models to integrate lethality to allow a continuous increase of process flexibility, without compromising its safety. The scientific community should also focus on other important issues, such as EO diffusion in different substrates, taking into account different environmental conditions both for sterilization and aeration

    Quantifying Quantum Correlations in Fermionic Systems using Witness Operators

    Full text link
    We present a method to quantify quantum correlations in arbitrary systems of indistinguishable fermions using witness operators. The method associates the problem of finding the optimal entan- glement witness of a state with a class of problems known as semidefinite programs (SDPs), which can be solved efficiently with arbitrary accuracy. Based on these optimal witnesses, we introduce a measure of quantum correlations which has an interpretation analogous to the Generalized Robust- ness of entanglement. We also extend the notion of quantum discord to the case of indistinguishable fermions, and propose a geometric quantifier, which is compared to our entanglement measure. Our numerical results show a remarkable equivalence between the proposed Generalized Robustness and the Schliemann concurrence, which are equal for pure states. For mixed states, the Schliemann con- currence presents itself as an upper bound for the Generalized Robustness. The quantum discord is also found to be an upper bound for the entanglement.Comment: 7 pages, 6 figures, Accepted for publication in Quantum Information Processin
    corecore