Full-duplex wireless-over-fibre transmission incorporating a CWDM ring architecture with remote millimetre-wave LO delivery using a bi-directional SOA

We demonstrate the first full-duplex wireless-over-fibre transmission between a central station and a CWDM ring architecture with remote 40 GHz LO delivery using a bi-directional semiconductor optical amplifier. © 2005 Optical Society of America.

A política polissêmica: fazeres, dizeres e silêncio nos programas Fale com o Deputado e Fale com a Ouvidoria da Câmara dos Deputados

Estudo sobre os programas Fale com o Deputado e Fale com a Ouvidoria da Câmara dos Deputados, a fim de se captarem representações, crenças e valores sobre a política. O trabalho assume a perspectiva de uma antropologia da política, desnaturalizando conceitos como democracia, participação e representação política, para captar as concepções dos sujeitos envolvidos no diálogo proposto pela Câmara dos Deputados, por intermédio desses canais de correio eletrônico. Assim, a tese não estuda os programas Fale com o Deputado e Fale com a Ouvidoria, mas nos programas. As mensagens enviadas, juntamente com os documentos produzidos pela Casa Legislativa acerca dos programas, bem como notícias e entrevistas com parlamentares e assessores sobre eles, são suportes de expressão de significados associados ao mundo da política, muitas vezes, concebidos como excludentes. Assim, eles são veículos de expressão, mas também de ação, que expõem combinações, normalmente contrapostas, por uma espécie de ficção construída em torno da noção de modernidade: indivíduo e pessoa, diretos e favores, particular e universal. Os documentos abordados revelam conciliações e embates discursivos que acenam para distintas maneiras de os atores fazerem a política, as quais acabam por revelar entendimentos sobre como se dá a gestão interna à Casa desses programas e questionamentos a respeito dos limites e possibilidades da Internet no fazer político.

Two-phase Flow in Fuel Cells in Short-term Microgravity Condition

A visual observation of liquid-gas two-phase flow in anode channels of a direct methanol proton exchange membrane fuel cells in microgravity has been carried out in a drop tower. The anode flow bed consisted of 2 manifolds and 11 parallel straight channels. The length, width and depth of single channel with rectangular cross section was 48.0 mm, 2.5 mm and 2.0 mm, respectively. The experimental results indicated that the size of bubbles in microgravity condition is bigger than that in normal gravity. The longer the time, the bigger the bubbles. The velocity of bubbles rising is slower than that in normal gravity because buoyancy lift is very weak in microgravity. The flow pattern in anode channels could change from bubbly flow in normal gravity to slug flow in microgravity. The gas slugs blocked supply of reactants from channels to anode catalyst layer through gas diffusion layer. When the weakened mass transfer causes concentration polarization, the output performance of fuel cells declines.

Environmental judgment in early childhood and its relationship with the understanding of the concept of living beings

The evidence collected concerning the biocentric judgment that young children express when evaluating human actions on the environment leads some scholars to suggest that an essential understanding of the notion of living beings should appear earlier than previously believed. This research project aims to study that assumption. To this end, young children’s choice when they are put in situation of having to compare and choose the most negative option between environmentally harmful actions and the breaking of social conventions are examined. Afterwards, the results are categorized in relation to those obtained from the study of children’s grasp of the distinction between living beings and inanimate entities. The data is analysed according to the individuals’ age and overall, it suggests a lack of relationship between environmental judgment and the understanding of the concept of living beings. The final results are discussed in keeping with recent research in the field of moral development that underscores the role that unconscious emotional processing plays in the individual’s normative judgment.

El tratamiento penal del delincuente imputable peligroso

XI, 529 p.

Measuring Learning Outcomes in Library Instruction

The author uses clicker technology to incorporate polling and multiple choice question techniques into library instruction classes. Clickers can be used to give a keener understanding of how many students grasp the concepts presented in a specific class session. Typically, a student that aces a definition-type question will fail to answer an application-type question correctly. Immediate, electronic feedback helps to calibrate teaching approaches and gather data about learning outcomes. This presentation will analyze learning outcomes specific to scientific disciplines, and demonstrate the usefulness of clickers to engage and sustain student learning.

Development of an efficient particle approach for micro-scale gas flow simulations

The micro-scale gas flows are usually low-speed flows and exhibit rarefied gas effects. It is challenging to simulate these flows because traditional CFD method is unable to capture the rarefied gas effects and the direct simulation Monte Carlo (DSMC) method is very inefficient for low-speed flows. In this study we combine two techniques to improve the efficiency of the DSMC method. The information preservation technique is used to reduce the statistical noise and the cell-size relaxed technique is employed to increase the effective cell size. The new cell-size relaxed IP method is found capable of simulating micro-scale gas flows as shown by the 2D lid-driven cavity flows.

Two-Phase Flow In Anode Flow Field Of A Small Direct Methanol Fuel Cell In Different Gravities

An in-situ visualization of two-phase flow inside anode flow bed of a small liquid fed direct methanol fuel cells in normal and reduced gravity has been conducted in a drop tower. The anode flow bed consists of 11 parallel straight channels. The length, width and depth of single channel, which had rectangular cross section, are 48.0, 2.5 and 2.0 mm, respectively. The rib width was 2.0 mm. The experimental results indicated that when the fuel cell orientation is vertical, two-phase flow pattern in anode channels can evolve from bubbly flow in normal gravity into slug flow in microgravity. The size of bubbles in the reduced gravity is also bigger. In microgravity, the bubbles rising speed in vertical channels is obviously slower than that in normal gravity. When the fuel cell orientation is horizontal, the slug flow in the reduced gravity has almost the same characteristic with that in normal gravity. It implies that the effect of gravity on two-phase flow is small and the bubbles removal is governed by viscous drag. When the gas slugs or gas columns occupy channels, the performance of liquid fed direct methanol fuel cells is failing rapidly. It infers that in long-term microgravity, flow bed and operating condition should be optimized to avoid concentration polarization of fuel cells.

A numerical investigation on the flow physics of koi carp (Cyprinus carpio koi) burst-and-coast swimming

Abstract—Burst-and-coast is the most common locomotion type in freely routine swimming of koi carps (Cyprinus carpio koi), which consists of a burst phase and a coast phase in each cycle and mostly leads to a straight-line trajectory. Combining with the tracking experiment, the flow physics of koi carp’s burst-andcoast swimming is investigated using a novel integrated CFD method solving the body-fluid interaction problem. The dynamical equations of a deforming body are formulated. Following that, the loose-coupled equations of the body dynamics and the fluid dynamics are numerically solved with the integrated method. The two burst modes, MT (Multiple Tail-beat) and HT (Half Tail-beat), which have been reported by the experiments, are investigated by numerical simulations in this paper. The body kinematics is predicted and the flow physics is visualized, which are in good agreement with the corresponding experiments. Furthermore, the optimization on the energy cost and several critical control mechanisms in burst-and-coast swimming of koi carps are explored, by varying the parameters in its selfpropelled swimming. In this paper, energetics is measured by the two mechanical quantities, total output power CP and Froude efficiency Fr. Results and discussion show that from the standpoint of mechanical energy, burst-and-coast swimming does not actually save energy comparing with steady swimming at the same average speed, in that frequently changing of speed leads to decrease of efficiency.