From Perturbation Theory to Confinement: How the String Tension is built up

We study the spatial volume dependence of electric flux energies for SU(2) Yang-Mills fields on the torus with twisted boundary conditions. The results approach smoothly the rotational invariant Confinement regime. The would-be string tension is very close to the infinite volume result already for volumes of $(1.2 \ {\rm fm.})^3$. We speculate on the consequences of our result for the Confinement mechanism.Comment: 6p, ps-file (uuencoded). Contribution to Lattice'93 Conference (Dallas, 1993). Preprint INLO-PUB 18/93, FTUAM-93/4

Multiple Order Dual-Band Active Ring Filters with Composite Right/Left Handed Cells

In this paper, a novel dual-band active filter topology is presented. The non-linear phase response of a composite right/left-handed cell is used to achieve the desired dual-band performance. Additionally, the proposed structure based on coupled ring resonators yields a very compact solution in which high-order implementations can be easily obtained by cascading multiple rings. The theoretical principles of this type of filters are analyzed in detail. Finally, three prototypes based on first-, second- and third-order structures validate the feasibility of this type of filters. Good agreement between simulations and measurements has been achieved

Effectiveness of aluminosilicate-based products for detoxification of aflatoxin-contaminated diets for juvenile Pacific white shrimp, Litopenaeus vannamei

Se evaluaron la seguridad y efectividad de cuatro productos a base de aluminosilicatos (Novasil Plus, Zeolex Extra, Mycofix Select y Fixat) durante 42 días en juveniles de camarón blanco del Pacífico, Litopenaeus vannamei, alimentados con granos de maíz que habían sido previamente inoculados con Aspergillus parasiticus y después esterilizados. Dos dietas control, una no contaminada y otra contaminada con el grano de maíz inoculado, fueron elaboradas para contener una concentración de 0 y 75 µg kg–1 de aflatoxinas totales. Ambas dietas fueron formuladas para contener 38% de proteína cruda y 8% de lípidos crudos. Ocho dietas más fueron elaboradas a partir de las dos dietas controles para contener cada uno de los productos a evaluar a un nivel de inclusión de 2.5 a 5.0 g kg–1, siguiendo las recomendaciones del productor. La inclusión de Mycofix Select y Fixat mejoró la estabilidad de las dietas (12–16%). La capacidad de absorción de agua de las dietas se incrementó (de 2% a 17%) debido a la suplementación de aluminosilicatos. Las dietas contaminadas con aflatoxinas disminuyeron el consumo de alimento y el aumento de peso sin afectar la tasa de conversión alimenticia, la eficiencia de retención de nitrógeno y la supervivencia de los camarones. La alimentación con las dietas no contaminadas suplementadas con Zeolex Extra, Mycofix Select y Fixat redujo ligeramente el consumo de alimento sin decremento de la tasa de crecimiento, la eficiencia de retención de nitrógeno y la supervivencia. En cambio, la inclusión de Novasil Plus en la dieta no contaminada no afectó el consumo de alimento y mejoró la tasa de crecimiento en un 8%. Tres de los productos evaluados no proporcionaron una restauración completa del consumo de alimento y la tasa de crecimiento cuando fueron suplementados a una dieta contaminada con aflatoxinas ABSTRACT The safety and effectiveness of four aluminosilicate-based products (Novasil Plus, Zeolex Extra, Mycofix Select, and Fixat) were tested for 42 days on juvenile Pacific white shrimp, Litopenaeus vannamei, fed diets containing corn grains that had been previously inoculated with Aspergillus parasiticus and then sterilized. Two control diets, one uncontaminated and another contaminated with the contaminated corn grain, were elaborated to contain a final concentration of 0 and 75 µg kg–1 total aflatoxins. Both diets were formulated to contain 38% crude protein and 8% lipids. Eight more diets were manufactured from the previous two to contain each of the test products at inclusion levels of 2.5 to 5.0 g kg–1, in accordance with the inclusion level recommended by the manufacturer. Mycofix Select and Fixat inclusion improved diet stability (12–16%). Water absorption capacity in the diets increased (from 2% to 17%) due to the supplementation of aluminosilicates. Feeding aflatoxin-contaminated diets to Pacific white shrimp resulted in lower feed intake and weight gain without affecting the feed conversion ratio, nitrogen retention, and survival. Feeding the uncontaminated diets supplemented with Zeolex Extra, Mycofix Select, and Fixat resulted in a slight reduction in feed intake without affecting growth rate, nitrogen retention, or survival. Conversely, the inclusion of Novasil Plus in the uncontaminated diet did not affect feed intake and an 8% growth rate improval was observed. Three of the tested products failed to provide complete restoration of feed consumption and shrimp growth rate when added to the aflatoxin-contaminated diet

Noise Figure Measurement of Differential Amplifiers Using non-Ideal Baluns

This paper analyzes the noise and gain measurement of microwave differential amplifiers using two passive baluns. A general model of the baluns is considered, including potential losses and phase/amplitude unbalances. This analysis allows de-embedding the actual gain and noise performance of the isolated amplifier by using single-ended measurements of the cascaded system and baluns. Finally, measured results from two amplifier prototypes are used to validate the theoretical principles

Bell inequalities from multilinear contractions

We provide a framework for Bell inequalities which is based on multilinear contractions. The derivation of the inequalities allows for an intuitive geometric depiction and their violation within quantum mechanics can be seen as a direct consequence of non-vanishing commutators. The approach is motivated by generalizing recent work on non-linear inequalities which was based on the moduli of complex numbers, quaternions and octonions. We extend results on Peres conjecture about the validity of Bell inequalities for quantum states with positive partial transposes. Moreover, we show the possibility of obtaining unbounded quantum violations albeit we also prove that quantum mechanics can only violate the derived inequalities if three or more parties are involved.Comment: Published versio

A Highly Available Cluster of Web Servers with Increased Storage Capacity

Ponencias de las Decimoséptimas Jornadas de Paralelismo de la Universidad de Castilla-La Mancha celebradas el 18,19 y 20 de septiembre de 2006 en AlbaceteWeb servers scalability has been traditionally solved by improving software elements or increasing hardware resources of the server machine. Another approach has been the usage of distributed architectures. In such architectures, usually, file al- location strategy has been either full replication or full distribution. In previous works we have showed that partial replication offers a good balance between storage capacity and reliability. It offers much higher storage capacity while reliability may be kept at an equivalent level of that from fully replicated solutions. In this paper we present the architectural details of Web cluster solutions adapted to partial replication. We also show that partial replication does not imply a penalty in performance over classical fully replicated architectures. For evaluation purposes we have used a simulation model under the OMNeT++ framework and we use mean service time as a performance comparison metric.Publicad

Dual-Band Tunable Recursive Active Filter

This letter presents a novel recursive active filter topology that provides dual-band performance, with independent tuning capability in both bands. The dual-band operation is achieved by using two independent feedback lines. Additionally, linear phase shifters based on left-handed cells are included in these two branches in order to tune the center frequency of both pass bands

Current Problems Involving the Dismantle of Asbestos- Cement Sheets in Buildings. The Case of Central Market in Alicante

The project and the works described in this article mainly deal with the removal of the current asbestos-cement covering of the roof of the Central Market in Alicante and its replacement with zinc diamond-shaped scales, similar to the originals which were implemented in 1921 when the building was put into service. These upgrades were necessary to avoid the causes (and consequences) of rainwater infiltration, as described in an earlier report in 2006, also drafted by the author of this article. The article illustrates the difficulties involving the practical application of Spanish Code RD 396/2006 (minimum safety and health requirements for work with risk of exposure to asbestos) in a complex case such as this, especially with regard to aspects such as economic (increasing costs), technical (increased difficulty of implementation), and the total duration of the work (total increase in duration due to interference with other trades)

Optimización de carga de datos en un banco de pruebas de aviónica

Ponencias de las Decimocuartas Jornadas de Paralelismo de la Universidad Carlos III de Madrid celebradas el 15, 16 y 17 de septiembre de 2003 en Leganés, MadridEste artículo presenta las técnicas de optimización utilizadas para acelerar la carga de definiciones de señales de un banco de pruebas de aviónica. La carga de datos en formato XML puede presentar problemas de rendimiento cuando se trata de grandes volumenes de datos. Bajo esas condiciones, es necesario buscar alternativas que permitan cargar los datos de forma más eficiente, sin imponer restricciones a los generadores de los datos utilizados como entrada. El artículo analiza posibles optimizaciones y valora las ventajas e inconvenientes de cada solución.Publicad