524 research outputs found

    Will current electric vehicle policy lead to cost-effective electrification of passenger car transport?

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    Encouraged by the falling cost of batteries, electric vehicle (EV) policy today focuses on expediting electrification, paying comparatively little attention to the cost of the particular type of EVs and charging infrastructure deployed. This paper argues that, due to its strong influence on EV innovation paths, EV policy could be better designed if it paid more attention to cost and technology development risk. In particular, using a model that estimates the incremental cost of different EV and infrastructure mixes over the whole passenger car fleet, we find that EV policy with a strong bias towards long-range battery electric vehicles (BEVs) risks leading to higher costs of electrification in the medium term, possibly exceeding the ability of governments to sustain the necessary incentives until battery cost drops sufficiently. We also find that promoting a balanced mix of BEVs and plug-in hybrid electric vehicles (PHEVs) may set the electrification of passenger cars on a lower risk, lower cost path. Examining EV policy in the UK and in California, we find that it is generally not incompatible with achieving balanced mixes of BEVs and PHEVs. However some fine tuning would allow to better balance medium term risks and long term goals

    A digital design process for shell structures

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    Over the last few decades, the design of freeform structures has undergone a radical change: powerful computational tools within parametric environment associated with digital fabrication techniques are pushing the boundaries of architecture towards bold solutions. The present work proposes a digital workflow for a shell in compression. The design process starts with the form-finding phase, which generates a hanging model. Through the interoperability of digital tools within parametric environment, optimization of the shape and structural analysis were carried out in order to investigate its behavior. The resulting surface is subject to tessellation, planarization of its cells that take into account fabrication constrains, and the 3D generation of panels composing the thickness of the structure. In order to accomplish an easier assembly process a hypothesis of a puzzle-like connection system was developed. The whole process provides a guidance for the design of freeform shell by the creation of a “customized” digital workflow implemented by digital fabrication techniques for the realization phase

    Digital Tessellation and Fabrication of the ECHO shell

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    Biomedical aspects of pyridoxal 5 -phosphate availability

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    The biologically active form of vitamin B6, pyridoxal 5'-phosphate (PLP), is a cofactor in over 160 enzyme activities involved in a number of metabolic pathways, including neurotransmitter synthesis and degradation. In humans, PLP is recycled from food and from degraded PLP-dependent enzymes in a salvage pathway requiring the action of pyridoxal kinase, pyridoxine 5'-phosphate oxidase and phosphatases. Once pyridoxal 5'-phosphate is made, it is targeted to the dozens different apoenzymes that need it as a cofactor. The regulation of the salvage pathway and the mechanism of addition of PLP to the apoenzymes are poorly understood and represent a very challenging research field. Severe neurological disorders, such as convulsions and epileptic encephalopathy, result from a reduced availability of pyridoxal 5'-phosphate in the cell, due to inborn errors in the enzymes of the salvage pathway or other metabolisms and to interactions of drugs with PLP or pyridoxal kinase. Multifactorial neurological pathologies, such as autism, schizophrenia, Alzheimer's disease, Parkinson's disease and epilepsy have also been correlated to inadequate intracellular levels of PLP

    A simple and low-power optical limiter for multi-GHz pulse trains

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    We study the limiting-amplification capability of a saturated Semiconductor Optical Amplifier (SOA) followed by an optical band-pass filter. We experimentally demonstrate that this simple optical circuit can be effectively exploited to realize a low-power optical limiter for amplitude-modulated pulse trains at multi-GHz repetition rate. We report very large amplitude-modulation-reduction factors for the case of 20 and 40 GHz pulse trains that are super-imposed with modulating frequencies ranging from 100kHz to several GHz. (C) 2007 Optical Society of America

    A simple and low-power optical limiter for multi-GHz pulse trains

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    We study the limiting-amplification capability of a saturated Semiconductor Optical Amplifier (SOA) followed by an optical band-pass filter. We experimentally demonstrate that this simple optical circuit can be effectively exploited to realize a low-power optical limiter for amplitudemodulated pulse trains at multi-GHz repetition rate. We report very large amplitude-modulation-reduction factors for the case of 20 and 40 GHz pulse trains that are super-imposed with modulating frequencies ranging from 100 kHz to several GHz

    EU polluting emissions: an empirical analysis

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    We provide an empirical study of the evolution of emissions of some specific air pollutants on a panel of EU member states from 1990 to 2000, and we relate observed patterns to macroeconomic performance. The ratio pollution emission to GDP, so-called emission intensity, has decreased over the period considered in most EU member states. However, a non-parametric analysis reveals that the relative positions of different countries in terms of GDP growth and reduction of emissions have remained basically unchanged. More specifically, remarkable differences can be detected between the richest and the poorest EU members notwithstanding. Also, more dispersion in emissions levels can be found in those countries with lower per capita GDP

    The multifaceted role of vitamin b6 in cancer: drosophila as a model system to investigate dna damage

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    A perturbed uptake of micronutrients, such as minerals and vitamins, impacts on different human diseases, including cancer and neurological disorders. Several data converge towards a crucial role played by many micronutrients in genome integrity maintenance and in the establishment of a correct DNA methylation pattern. Failure in the proper accomplishment of these processes accelerates senescence and increases the risk of developing cancer, by promoting the formation of chromosome aberrations and deregulating the expression of oncogenes. Here, the main recent evidence regarding the impact of some B vitamins on DNA damage and cancer is summarized, providing an integrated and updated analysis, mainly centred on vitamin B6. In many cases, it is difficult to finely predict the optimal vitamin rate that is able to protect against DNA damage, as this can be influenced by a given individual's genotype. For this purpose, a precious resort is represented by model organisms which allow limitations imposed by more complex systems to be overcome. In this review, we show that Drosophila can be a useful model to deeply understand mechanisms underlying the relationship between vitamin B6 and genome integrity

    The composite dataset of the present-day Infralittoral Prograding Wedges (IPWs) in the inner continental shelf of the Campania region (Central-Eastern Tyrrhenian Sea)

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    This article reports on the dataset gathered following the census of 83 present-day Infralittoral Prograding Wedges (IPWs), surveyed on the inner continental shelf of the Central-Eastern Tyrrhenian Sea. The purpose of the census was to explore their bathymetric range and assess the observational laws governing this variability. The ensued dataset (Campania Region IPW Dataset, CRID) includes geographic, topographic and morpho-bathymetric indices, descriptive of each IPW and more, the exposure of each IPW to wave forcing (Geographical fetch, Effective fetch and extreme significant wave height, HS). In this work, histograms contribute to describe all the variables and highlight the dominant features of each IPW. Location maps univocally links the geographic position of each IPW to the appropriate attribute record in the dataset. Further, thematic maps illustrate eight wave fields obtained by offshore-to-nearshore transformation by as many sea states scenarios with 200-year return period. Such wave fields are used as sources for significant wave height representing wave conditions over each IPW. This dataset could be implemented with new measures at a broader scale, by following analogue procedures for measurements, to enlarge the observational scale on IPWs and improve the numerical models which might eventually derive by the analysis of this dataset
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