Simple operational interpretation of the fidelity of mixed states

This Brief Report presents a corollary to Uhlmann's theorem which provides a simple operational interpretation of the fidelity of mixed states.

A simple formula for the average gate fidelity of a quantum dynamical operation

This Letter presents a simple formula for the average fidelity between a unitary quantum gate and a general quantum operation on a qudit, generalizing the formula for qubits found by Bowdrey et al. [Phys. Lett. A 294 (2002) 258]. This formula may be useful for experimental determination of average gate fidelity. We also give a simplified proof of a formula due to Horodecki et al. [Phys. Rev. A 60 (1999) 1888], connecting average gate fidelity to entanglement fidelity. (C) 2002 Elsevier Science B.V. All rights reserved.

Work domain analysis and sensors I: principles and simple example

In this paper we establish a foundation for understanding the instrumentation needs of complex dynamic systems if ecological interface design (EID)-based interfaces are to be robust in the face of instrumentation failures. EID-based interfaces often include configural displays which reveal the higher-order properties of complex systems. However, concerns have been expressed that such displays might be misleading when instrumentation is unreliable or unavailable. Rasmussen's abstraction hierarchy (AH) formalism can be extended to include representations of sensors near the functions or properties about which they provide information, resulting in what we call a sensor-annotated abstraction hierarchy. Sensor-annotated AHs help the analyst determine the impact of different instrumentation engineering policies on higher-order system information by showing how the data provided from individual sensors propagates within and across levels of abstraction in the AH. The use of sensor-annotated AHs with a configural display is illustrated with a simple water reservoir example. We argue that if EID is to be effectively employed in the design of interfaces for complex systems, then the information needs of the human operator need to be considered at the earliest stages of system development while instrumentation requirements are being formulated. In this way, Rasmussen's AH promotes a formative approach to instrumentation engineering. (C) 2002 Elsevier Science Ltd. All rights reserved.

Empoderamiento de mujeres de una ONG colombiana. Un estudio de caso simple

Resumen:Este artículo es un estudio de caso sobre cómo un grupo de mujeres se empoderan, conforman una ONG y generan empoderamiento en su comunidad, argumentando que el empoderamiento es un proceso en el tiempo, el cual se da en tres niveles psicológico, organizacional y comunitario. El empoderamiento en las mujeres es interdependiente, emerge como producto de la acción de ellas sobre los problemas sociales y públicos de su comunidad, e impacta el desarrollo social en la medida en que se transforman los valores que tienen las mujeres sobre qué es una mujer y cómo es en su realidad. La ONGD de mujeres genera empoderamiento a partir de la Teología de la liberación basada en la eliminación de la opresión de género. Los hallazgos del estudio son un aporte a la comprensión del empoderamiento en organizaciones de mujeres que desarrollan políticas públicas sociales.

Simple thermodynamics of jet engines

We use the first and second laws of thermodynamics to analyze the behavior of an ideal jet engine. Simple analytical expressions for the thermal efficiency, the overall efficiency, and the reduced thrust are derived. We show that the thermal efficiency depends only on the compression ratio r and on the velocity of the aircraft. The other two performance measures depend also on the ratio of the temperature at the turbine to the inlet temperature in the engine, T-3/T-i. An analysis of these expressions shows that it is not possible to choose an optimal set of values of r and T-3/T-i that maximize both the overall efficiency and thrust. We study how irreversibilities in the compressor and the turbine decrease the overall efficiency of jet engines and show that this effect is more pronounced for smaller T-3/T-i.

A dramatic effect of double bond configuration in N-oxy-3-aza Cope rearrangements: a simple synthesis of functionalised allenes

The first examples of low temperature N-oxy-3-aza Cope rearrangements, leading to functionalised allenes are described, where the Z-configuration of the enaminic double bond in the rearranging system proves critical.

Pour une approche contrastive du présent simple en français et en portugais

Les temps du passé ont toujours constitué une pierre d’achoppement aussi bien dans l’enseignement du français aux étudiants lusophones que dans celui du portugais aux francophones. Le flot continu d’articles sur ce sujet attesterait, à lui seul, la difficulté du problème. Mais aussi étonnant que cela puisse paraître, il n’existe à ce jour aucune étude systématique qui aborde sur une base théorique le présent simple dans le passage du français vers le portugais et/ou vice-versa. Or, une telle étude nous paraît une voie de recherche intéressante et fructueuse qui ouvre de nombreuses perspectives de recherche, dont les possibilités d’application, que ce soit au domaine de l’enseignement des langues étrangères ou celui de la traduction, ne sont pas négligeables. Cette réflexion est d’autant plus urgente que l’emploi du présent simple pose de sérieux problèmes aux élèves lusophones plus inexpérimentés. En effet, ces derniers ont parfois beaucoup de peine à trouver les bonnes correspondances du présent simple en portugais. Afin d’aboutir à des conclusions fiables sur les similarités et les divergences entre le français et le portugais quant aux conditions d’apparition et au mode de fonctionnement du présent simple, nous nous attacherons, dans l’étude contrastive qui suit, à examiner des échantillons de textes littéraires français traduits en portugais et des extraits de textes littéraires portugais traduits en français1. Il s’agira essentiellement de montrer, en recourant à la Théorie des Opérations Énonciatives d’Antoine Culioli (Culioli, 1990; Campos & Xavier, 1991; Campos, 1997, 1998, entre autres), par quels moyens linguistiques le portugais exprime les valeurs aspectuo-temporelles associées au présent simple en français.

Development of a simple analytical method for the simultaneousdetermination of paracetamol, paracetamol-glucuronide andp-aminophenol in river water

Paracetamol is among the most worldwide consumed pharmaceuticals. Although its occurrence in the environment is well documented, data about the presence of its metabolites and transformation products is very scarce. The present work describes the development of an analytical method for the simultaneous determination of paracetamol, its principal metabolite (paracetamol-glucuronide) and its main transformation product (p-aminophenol) based on solid phase extraction (SPE) and high performance liquid chromatography coupled to diode array detection (HPLC-DAD). The method was applied to analysis of river waters, showing to be suitable to be used in routine analysis. Different SPE sorbents were compared and the use of two Oasis WAX cartridges in tandem proved to be the most adequate approach for sample clean up and pre-concentration. Under optimized conditions, limits of detection in the range 40–67 ng/L were obtained, as well as mean recoveries between 60 and 110% with relative standard deviations (RSD) below 6%. Finally, the developed SPE-HPLC/DAD method was successfully applied to the analysis of the selected compounds in samples from seven rivers located in the north of Portugal. Nevertheless all the compounds were detected, it was the first time that paracetamol-glucuronide was found in river water at concentrations up to 3.57 μg/L.

A simple approach to numerical modelling of propane combustion in fluidized beds

A mathematical model is proposed for the evolution of temperature, chemical composition, and energy release in bubbles, clouds, and emulsion phase during combustion of gaseous premixtures of air and propane in a bubbling fluidized bed. The analysis begins as the bubbles are formed at the orifices of the distributor, until they explode inside the bed or emerge at the free surface of the bed. The model also considers the freeboard region of the fluidized bed until the propane is thoroughly burned. It is essentially built upon the quasi-global mechanism of Hautman et al. (1981) and the mass and heat transfer equations from the two-phase model of Davidson and Harrison (1963). The focus is not on a new modeling approach, but on combining the classical models of the kinetics and other diffusional aspects to obtain a better insight into the events occurring inside a fluidized bed reactor. Experimental data are obtained to validate the model by testing the combustion of commercial propane, in a laboratory-scale fluidized bed, using four sand particle sizes: 400–500, 315–400, 250–315, and 200–250 µm. The mole fractions of CO2, CO, and O2 in the flue gases and the temperature of the fluidized bed are measured and compared with the numerical results.

How short and light can a simple pendulum be for classroom use?

We compare the period of oscillation of an ideal simple pendulum with the period of a more 'real' pendulum constituted of a rigid sphere and a rigid slender rod. We determine the relative error in the calculation of the local acceleration of gravity if the period of the ideal pendulum is use?d instead of the period of this real pendulum. © 2014 IOP Publishing Ltd..

The simple economics of risk-sharing agreements between the NHS and the pharmaceutical industry

The Janssen-Cilag proposal for a risk-sharing agreement regarding bortezomib received a welcome signal from NICE. The Office of Fair Trading report included risk-sharing agreements as an available tool for the National Health Service. Nonetheless, recent discussions have somewhat neglected the economic fundamentals underlying risk-sharing agreements. We argue here that risk-sharing agreements, although attractive due to the principle of paying by results, also entail risks. Too many patients may be put under treatment even with a low success probability. Prices are likely to be adjusted upward, in anticipation of future risk-sharing agreements between the pharmaceutical company and the third-party payer. An available instrument is a verification cost per patient treated, which allows obtaining the first-best allocation of patients to the new treatment, under the risk sharing agreement. Overall, the welfare effects of risk-sharing agreements are ambiguous, and care must be taken with their use.

New simple digital self-calibration technique for pipeline ADCs using the internal thermal noise

IEEE International Symposium on Circuits and Systems, pp. 232 – 235, Seattle, EUA