835 research outputs found

    Optoelectronic cooling of mechanical modes in a semiconductor nanomembrane

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    Optical cavity cooling of mechanical resonators has recently become a research frontier. The cooling has been realized with a metal-coated silicon microlever via photo-thermal force and subsequently with dielectric objects via radiation pressure. Here we report cavity cooling with a crystalline semiconductor membrane via a new mechanism, in which the cooling force arises from the interaction between the photo-induced electron-hole pairs and the mechanical modes through the deformation potential coupling. The optoelectronic mechanism is so efficient as to cool a mode down to 4 K from room temperature with just 50 uW of light and a cavity with a finesse of 10 consisting of a standard mirror and the sub-wavelength-thick semiconductor membrane itself. The laser-cooled narrow-band phonon bath realized with semiconductor mechanical resonators may open up a new avenue for photonics and spintronics devices.Comment: 5 pages, 4 figure

    Road Safety Capacity Building in Belarus through the development of Road Safety Master Courses

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    The risk of traffic fatalities varies significantly across high, medium and low-income countries. Among the reasons for this in the latter ones, there is often a lack of road safety knowledge and political will. Road safety is a multidisciplinary topic and requires trained professionals able to identify and implement efficient measures in the areas of engineering, enforcement, education and emergency services, taking into consideration social and economic aspects as well. However, in some Eastern Europe Countries there are potential barriers to train adequately professionals, generally due to a lack of specialised training and training standardization. Such an example can be seen in Belarus where, although road safety is a key issue, it is not managed on an evidence-based approach and there seems to be insufficient funding for related research. An initiative towards increasing knowledge capacity is the Be-Safe project (EC Tempus), a joint effort between three EU Universities and four Belarusian Universities. The objective of this paper is to describe the methodology carried out in Be-Safe to develop and test for two years two 1st level Road Safety Master Courses (60 ECTS) in Belarus according to the Bologna process requirements. Initially, a User Needs Analysis was carried out to understand local conditions and needs in terms of teaching and research on road safety. The analysis highlighted a lack of research due to insufficient funding, linguistic barriers and inadequate international relationships. This isolation led to a need of updating contents and methods of courses for students as well as research topics. Then, expected learning outcomes and Masters' curricula, one for the Technical Universities and one for the Economics Universities, were defined and developed respectively. Finally, Masters' courses in four Belarusian Universities were tested. Quality results were ensured through a Quality Board and assessment tools to monitor the Masters' process as a whole

    Fabrication of nickel oxide and Ni-doped indium tin oxide thin films using pyrosol process

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    ArticleTHIN SOLID FILMS. 498(1-2): 240-243journal articl

    Improving sustainable mobility in university campuses. The case study of Sapienza University

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    The pursue of sustainable mobility is one of the greatest environmental challenges nowadays. It requires a people mind shift, where the use of private vehicles give way to different modes of public transport like buses, bicycles, car sharing, electric cars, and walking lanes. This new call to make mobility sustainable has already been undertaken by policymakers and public managers in many urban contexts around the world, as well as, more recently, by the managers of university systems. The paper shows the work developed in 2018 for the Sapienza Sustainable University Mobility Plan (SUMP). The study stems from the need to understand and improve, in the sustainability direction, modes of travel for the students and staff of one of the oldest universities in the world, and one of the largest in Europe (112,142 students enrolled and 23,101 between academic staff and no academic staff), with its premises located in a complex and challenging urban context such as the city of Rome. The SUMP has been developed in two phases. The first one investigated travel patterns and the reasons for the modal shift and highlighted the main issues. The second phase defined strategies and interventions to be implemented in the short, medium, and long term to make students and staff's mobility more environmentally sustainable. The methodology used in the fact-finding stage was the online survey that was carried out through the use of a diversified questionnaire for staff and students of the University. The sample of students who participated in the survey amounted to 14,719 units, while the sample of faculty and staff was 9,403. The main questionnaire outcomes showed that the attitudes recorded were largely different between faculty and staff and students. While for the first ones the choice of private vehicles is the first option (36%), for students public transport is the prevailing preference (78%). According to the critical aspects found in this first stage, the SUMP objectives were defined, leading to the identification of macro-areas of intervention and specific actions. At a policy and strategic level, the attention was focused on the guidelines issued by the United Nations, the European Commission, and the Network of Universities for Sustainable Development, of which Sapienza University is a member. For this reason, the identification of strategies and interventions results from the combination of the first phase analysis, the Sapienza Governance objectives, and the national and international context in which the SUMP was drafted. Five macro-areas of intervention have been identified: Smart Strategies, Pedestrian Mobility, Cycling, Local Public Transport, Private Transport, and for each one specific intervention to be implemented in different time frames have been defined

    Exceeding classical capacity limit in quantum optical channel

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    The amount of information transmissible through a communications channel is determined by the noise characteristics of the channel and by the quantities of available transmission resources. In classical information theory, the amount of transmissible information can be increased twice at most when the transmission resource (e.g. the code length, the bandwidth, the signal power) is doubled for fixed noise characteristics. In quantum information theory, however, the amount of information transmitted can increase even more than twice. We present a proof-of-principle demonstration of this super-additivity of classical capacity of a quantum channel by using the ternary symmetric states of a single photon, and by event selection from a weak coherent light source. We also show how the super-additive coding gain, even in a small code length, can boost the communication performance of conventional coding technique.Comment: 4 pages, 3 figure

    Nonadditivity effects in classical capacities of quantum multiple-access channels

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    We study classical capacities of quantum multi-access channels in geometric terms revealing breaking of additivity of Holevo-like capacity. This effect is purely quantum since, as one points out, any classical multi-access channels have their regions additive. The observed non-additivity in quantum version presented here seems to be the first effect of this type with no additional resources like side classical or quantum information (or entanglement) involved. The simplicity of quantum channels involved resembles butterfly effect in case of classical channel with two senders and two receivers.Comment: 5 pages, 5 figure

    Increase in the conductivity and work function of pyrosol indium tin oxide by infrared irradiation

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    ArticleTHIN SOLID FILMS. 484(1-2): 272-277 (2005)journal articl

    Implementation of generalized quantum measurements: superadditive quantum coding, accessible information extraction, and classical capacity limit

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    Quantum information theory predicts that when the transmission resource is doubled in quantum channels, the amount of information transmitted can be increased more than twice by quantum channel coding technique, whereas the increase is at most twice in classical information theory. This remarkable feature, the superadditive quantum coding gain, can be implemented by appropriate choices of code words and corresponding quantum decoding which requires a collective quantum measurement. Recently, the first experimental demonstration was reported [Phys. Rev. Lett. 90, 167906 (2003)]. The purpose of this paper is to describe our experiment in detail. Particularly, a design strategy of quantum collective decoding in physical quantum circuits is emphasized. We also address the practical implication of the gain on communication performance by introducing the quantum-classical hybrid coding scheme. We show how the superadditive quantum coding gain, even in a small code length, can boost the communication performance of conventional coding technique.Comment: 15 pages, 14 figure

    Validation of RNA Extraction Methods and Suitable Reference Genes for Gene Expression Studies in Developing Fetal Human Inner Ear Tissue

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    A comprehensive gene expression investigation requires high-quality RNA extraction, in sufficient amounts for real-time quantitative polymerase chain reaction and next-generation sequencing. In this work, we compared different RNA extraction methods and evaluated different reference genes for gene expression studies in the fetal human inner ear. We compared the RNA extracted from formalin-fixed paraffin-embedded tissue with fresh tissue stored at -80 °C in RNAlater solution and validated the expression stability of 12 reference genes (from gestational week 11 to 19). The RNA from fresh tissue in RNAlater resulted in higher amounts and a better quality of RNA than that from the paraffin-embedded tissue. The reference gene evaluation exhibited four stably expressed reference genes (B2M, HPRT1, GAPDH and GUSB). The selected reference genes were then used to examine the effect on the expression outcome of target genes (OTOF and TECTA), which are known to be regulated during inner ear development. The selected reference genes displayed no differences in the expression profile of OTOF and TECTA, which was confirmed by immunostaining. The results underline the importance of the choice of the RNA extraction method and reference genes used in gene expression studies

    Improving road safety knowledge in Africa through crowdsourcing. The African Road Safety Observatory

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    Africa is the worst performing continent in road safety: the fatality rate, 26.6 per 100.000 inhabitants, is almost three times that of Europe's and fatalities per capita are projected to double from 2015 to 2030 (WHO, 2015). This is mainly due to the fact that Emerging Economies are experiencing increases in traffic, for which their traffic systems are not sufficiently prepared. On one hand, there is a significant demand for data and knowledge to be used for road safety-related decision making. On the other hand, there is a substantial lack of a reliable and detailed knowledge on road casualties in terms of the number of road accidents and fatalities occurring and, on the factors, leading to road accidents or affecting their consequences. When official data are poor or missing these could be integrated with other sources. The objective of this paper is to describe the African Road Safety Observatory (African RSO), a participative web portal developed in the field of the "SaferAfrica-Innovating dialogue and problems appraisal for a safer Africa" project, funded by the European Union's Horizon 2020 program. The African RSO combines traditional functions of analyzing and sharing road safety performance data and provide knowledge and information, with the more innovative ones: a Dialogue Platform and the crowdsourcing tool. The Dialogue Platform is dedicated to experts and stakeholders and aims at encouraging and facilitating a constructive engagement and dialogue on road safety in Africa, producing knowledge to inspire road safety funding, policies and interventions in Africa and providing recommendations to update the African Road Safety Action Plan and the African Road Safety Charter. The crowdsourcing tool allows African citizens to report and highlight road safety needs, to share opinions as well as to discuss solutions in their own Countries
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