952 resultados para BOOST converter


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Urban spectacles such as the Olympic Games have been long perceived as being able to impose desired effects in the city that act as host. This kind of urban boost may include the creation of new jobs and revenue for local community, growth in tourism and convention business, improvements to city infrastructure and environment, and the stimulation of broad reform in the social, political and institutional realm. Nevertheless at the other end of the debate, the potentially detrimental impacts of Olympic urban development, particularly on disadvantaged and vulnerable groups, have also been increasingly noticed in recent years and subsequently cited by a number of high profile anti-Olympic groups to campaign against Olympic bids and awards. The common areas of concern over Olympic-related projects include the cost and debts risk, environmental threat, the occurrence of social imbalance, and disruption and disturbance of existing community life. Among these issues, displacement of low income households and squatter communities resulting from Olympic-inspired urban renewal are comparatively under-explored and have emerged as an imperative area for research inquiry. This is particularly the case where many other problems have become less prominent. Changing a city’s demographic landscape, particularly displacing lower income people from the area proposed for a profitable development is a highly contentious matter in its own right. Some see it as a natural and inevitable outgrowth of the process of urban evolution, without which cities cannot move towards a more attractive location for consumption-based business. Others believe it reflects urban crises and conflicts, highlighting the market failures, polarization and injustice. Regardless of perception,these phenomena are visible everywhere in post-industrial cities and particularly cannot be ignored when planning for the Olympic Games and other mega-events. The aim of this paper is to start the process of placing the displacement issue in the context of Olympic preparation and to seek a better understanding of their interrelations. In order to develop a better understanding of this issue in terms of cause, process, influential factors and its implication on planning policy, this paper studies the topic from both theoretic and empirical angles. It portrays various situations where the Olympics may trigger or facilitate displacement in host cities during the preparation of the Games, identifies several major variables that may affect the process and the overall outcome, and explores what could be learnt in generic terms for planning Olympic oriented infrastructure so that ill-effects to the local community can be effectively controlled. The paper concludes that the selection of development sites, the integration of Olympic facilities with the city’s fabric, the diversity of housing type produced for local residents and the dynamics of the new socioeconomic structure.

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Paper presented at the Cloud Forward Conference 2015, October 6th-8th, Pisa

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The marine cyanobacterium Prochlorococcus, the most abundant phototrophic organism on Earth, numerically dominates the phytoplankton in nitrogen (N)-depleted oceanic gyres. Alongside inorganic N sources such as nitrite and ammonium, natural populations of this genus also acquire organic N, specifically amino acids. Here, we investigated using isotopic tracer and flow cytometric cell sorting techniques whether amino acid uptake by Prochlorococcus is subject to a diel rhythmicity, and if so, whether this was linked to a specific cell cycle stage. We observed, in contrast to diurnally similar methionine uptake rates by Synechococcus cells, obvious diurnal rhythms in methionine uptake by Prochlorococcus cells in the tropical Atlantic. These rhythms were confirmed using reproducible cyclostat experiments with a light-synchronized axenic Prochlorococcus (PCC9511 strain) culture and S-35-methionine and H-3-leucine tracers. Cells acquired the tracers at lower rates around dawn and higher rates around dusk despite > 10(4) times higher concentration of ammonium in the medium, presumably because amino acids can be directly incorporated into protein. Leucine uptake rates by cells in the S+G(2) cell cycle stage were consistently 2.2 times higher than those of cells at the G(1) stage. Furthermore, S+G(2) cells upregulated amino acid uptake 3.5 times from dawn to dusk to boost protein synthesis prior to cell division. Because Prochlorococcus populations can account from 13% at midday to 42% at dusk of total microbial uptake of methionine and probably of other amino acids in N-depleted oceanic waters, this genus exerts diurnally variable, strong competitive pressure on other bacterioplankton populations.

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In the near future, the oceans will be subjected to a massive development of marine infrastructures, including offshore wind, tidal and wave energy farms and constructions for marine aquaculture. The development of these facilities will unavoidably exert environmental pressures on marine ecosystems. It is therefore crucial that the economic costs, the use of marine space and the environmental impacts of these activities remain within acceptable limits. Moreover, the installation of arrays of wave energy devices is still far from being economically feasible due to many combined aspects, such as immature technologies for energy conversion, local energy storage and moorings. Therefore, multi-purpose solutions combining renewable energy from the sea (wind, wave, tide), aquaculture and transportation facilities can be considered as a challenging, yet advantageous, way to boost blue growth. This would be due to the sharing of the costs of installation and using the produced energy locally to feed the different functionalities and optimizing marine spatial planning. This paper focuses on the synergies that may be produced by a multi-purpose offshore installation in a relatively calm sea, i.e., the Northern Adriatic Sea, Italy, and specifically offshore Venice. It analyzes the combination of aquaculture, energy production from wind and waves, and energy storage or transfer. Alternative solutions are evaluated based on specific criteria, including the maturity of the technology, the environmental impact, the induced risks and the costs. Based on expert judgment, the alternatives are ranked and a preliminary layout of the selected multi-purpose installation for the case study is proposed, to further allow the exploitation of the synergies among different functionalities.

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The incorporation of one-dimensional simulation codes within engine modelling applications has proved to be a useful tool in evaluating unsteady gas flow through elements in the exhaust system. This paper reports on an experimental and theoretical investigation into the behaviour of unsteady gas flow through catalyst substrate elements. A one-dimensional (1-D) catalyst model has been incorporated into a 1-D simulation code to predict this behaviour.

Experimental data was acquired using a ‘single pulse’ test rig. Substrate samples were tested under ambient conditions in order to investigate a range of regimes experienced by the catalyst during operation. This allowed reflection and transmission characteristics to be quantified in relation to both geometric and physical properties of substrate elements. Correlation between measured and predicted results is demonstrably good and the model provides an effective analysis tool for evaluating unsteady gas flow through different catalytic converter designs.

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The potential of intensity modulated radiotherapy (IMRT) to improve the therapeutic ratio in prostate cancer by dose escalation of intraprostatic tumour nodules (IPTNs) was investigated using a simultaneous integrated boost technique. The prostate and organs-at-risk were outlined on CT images from six prostate cancer patients. Positions of IPTNs were transferred onto the CT images from prostate maps derived from sequential large block sections of whole prostatectomy specimens. Inverse planned IMRT dose distributions were created to irradiate the prostate to 70 Gy and all the IPTNs to 90 Gy. A second plan was produced to escalate only the dominant IPTN (DIPTN) to 90 Gy, mimicking current imaging techniques. These plans were compared with homogeneous prostate irradiation to 70 Gy using dose–volume histograms, tumour control probability (TCP) and normal tissue complication probability (NTCP) for the rectum. The mean dose to IPTNs was increased from 69.8 Gy to 89.1 Gy if all the IPTNs were dose escalated (p=0.0003). This corresponded to a mean increase in TCP of 8.7–31.2% depending on the /ß ratio of prostate cancer (p

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This research analyses the importance of the training for the promotion of the social economy in two ways: 1) focusing on the characteristics of the educational offer of Social Economy and 2) analyzing its differences regarding to those studies from the Management, entrepreneurship, and innovations areas. To this aim, it is carried out as a first step a literature review of the contributions that study the relationships that can exist between the education and Economy. Then, being based on this previous analysis, we already center our research on the Social Economy sector and its relations with the education system. To get this objective, it has been developed a database that includes all the postgraduate titles related to the Economics area. Likewise, a questionnaire has been designed with the aim of characterize the training in social Economy. As a conclusion, it is obtained that the training in social economy in postgraduate studies in the Spanish Universities is very poor. On the other hand, there are significant differences between Social Economy degrees and Business Management, entrepreneurship and innovation degrees with regard to different aspects such as: values to transmit, competencies, skills, the way of understanding the Economy, etc. Based on these conclusions, different recommendations are proposed in order to promote and boost this other way of doing Economy through the training and education in postgraduate studies.

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Damping torque analysis is a well-developed technique for understanding and studying power system oscillations. This paper presents the applications of damping torque analysis for DC bus implemented damping control in power transmission networks in two examples. The first example is the investigation of damping effect of shunt VSC (Voltage Source Converter) based FACTS voltage control, i.e., STATCOM (Static Synchronous Compensator) voltage control. It is shown in the paper that STATCOM voltage control mainly contributes synchronous torque and hence has little effect on the damping of power system oscillations. The second example is the damping control implemented by a Battery Energy Storage System (BESS) installed in a power system. Damping torque analysis reveals that when BESS damping control is realized by regulating exchange of active and reactive power between the BESS and power system respectively, BESS damping control exhibits different properties. It is concluded by damping torque analysis that BESS damping control implemented by regulating active power is better with less interaction with BESS voltage control and more robust to variations of power system operating conditions. In the paper, all analytical conclusions obtained are demonstrated by simulation results of example power systems.

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The introduction of new degrees in the Faculty of Education and the relevance of educational guidance comes to them, as a compulsory subject in all four grades started from 2009-2010, gives the opportunity to return and boost the University Guidance Service (UGS) as a means of consistency with the profile of their education and professional development of its students. The aim of the paper focuses on the evaluation of the results after the first year of implementing a peer mentoring project, SOU-estuTUtor Project, developed from UGS with all degree students of the Faculty of Education for Students new entrants. Program has been evaluated through the perception and satisfaction of the mentors on the organization, training, skills developed and adapted to the needs of students. After one academic year of implementation, the results show, on the one hand, the satisfaction and commitment of those involved and the partial response to the needs of the students served, as well as the optimization of the personal resources of the university but also some limitations that make it necessary to review the mentoring program in terms of control and duration of the process.

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This article presents an educational experiment carried out in the Primary School Teaching Degree at the University of Barcelona. Specifically, the article analyses the application of the “Work Corners” approach in a core subject. In a three-year action research process, trainers put into practice an innovation which enabled them to boost cooperative work and reflexive learning among trainees. Firstly, the theoretical model underpinning the project and guiding many of the actions carried out by the training team is presented. After providing detailed information on the practical development of the experiment, the data-gathering process and its results are shown. Various information-gathering strategies were used in assessing the project, such as a questionnaire, participant observation, and teachers’ diaries. The results demonstrate, amongst other things, that “work corners” offer viable and appropriate educational conditions for the articulation of theoretical and practical knowledge, for building professional knowledge, and therefore, the beginnings of a reflexive teaching practice.

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A three-phase four-wire shunt active power filter for harmonic mitigation and reactive power compensation in power systems supplying nonlinear loads is presented. Three adaptive linear neurons are used to tackle the desired three-phase filter current templates. Another feedforward three-layer neural network is adopted to control the output filter compensating currents online. This is accomplished by producing the appropriate switching patterns of the converter's legs IGBTs. Adequate tracking of the filter current references is obtained by this method. The active filter injects the current required to compensate for the harmonic and reactive components of the line currents, Simulation results of the proposed active filter indicate a remarkable improvement in the source current waveforms. This is reflected in the enhancement of the unified power quality index defined. Also, the filter has exhibited quite a high dynamic response for step variations in the load current, assuring its potential for real-time applications

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An increasing understanding of the process of erythropoiesis raises some interesting questions about the pathophysiology, diagnosis and treatment of anemia and erythrocytosis. The mechanisms underlying the development of many of the erythrocytoses, previously characterised as idiopathic, have been elucidated leading to an increased understanding of oxygen homeostasis. Characterisation of anemia and erythrocytosis in relation to serum erythropoietin levels can be a useful addition to clinical diagnostic criteria and provide a rationale for treatment with erythropoiesis stimulating agents (ESAs). Recombinant human erythropoietin as well as other ESAs are now widely used to treat anemias associated with a range of conditions, including chronic kidney disease, chronic inflammatory disorders and cancer. There is also heightened awareness of the potential abuse of ESAs to boost athletic performance in competitive sport. The discovery of erythropoietin receptors outside of the erythropoietic compartment may herald future applications for ESAs in the management of neurological and cardiac diseases. The current controversy concerning optimal hemoglobin levels in chronic kidney disease patients treated with ESAs and the potential negative clinical outcomes of ESA treatment in cancer reinforces the need for cautious evaluation of the pleiotropic effects of ESAs in non-erythroid tissues.

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A techno-economic model of an autonomous wave-powered desalination plant is developed and indicates that fresh water can be produced for as little as £0.45/m3. The advantages of an autonomous wave-powered desalination plant are also discussed indicating that the real value of the system is enhanced due to its flexibility for deployment and reduced environmental impact. The modelled plant consists of the Oyster wave energy converter, conventional reverse osmosis membranes and a pressure exchanger–intensifier for energy recovery. A time-domain model of the plant is produced using wave-tank experimentation to calibrate the model of Oyster, manufacturer's data for the model of the reverse osmosis membranes and a hydraulic model of the pressure exchanger–intensifier. The economic model of the plant uses best-estimate cost data which are reduced to annualised costs to facilitate the calculation of the cost of water. Finally, the barriers to the deployment of this technology are discussed, but they are not considered insurmountable.

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The potential for an autonomous wave-powered desalination system is considered and it is identified that the most promising configuration is a reverse osmosis (RO) plant utilising a pressure exchanger-intensifier for energy recovery. A numerical model of the RO plant with a pressure exchanger-intensifier is developed that shows that a specific energy consumption of less than 2.0 kW h/m3 over a wide range of sea-water feed conditions, making it particularly suitable for use with a variable power source such as wave energy. A numerical model of the combined wave-power and desalination plant is also developed that shows that it is possible to supply the desalination plant with sea-water directly pressurised by the wave energy converter, eliminating the cost and energy losses associated with converting the energy into electricity and back to pressurised water. For a typical sea-state the specific hydraulic energy consumption of the desalination plant is estimated to be 1.85 kW h/m3 whilst maintaining a recovery-ratio of less than 25 to 35% to avoid the need for chemical pre-treatment to eliminate scaling problems. It is suggested that the economic potential for wave-powered desalination depends on these energy and cost savings more than compensating for the reduction in membrane life that occurs with variable feed conditions.

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Intracranial metastatic prostate carcinoma is rare. We sought to determine the clinical outcomes after Gamma Knife® stereotactic radiosurgery (GKSRS) for patients with intracranial prostate carcinoma metastases. We studied data from 10 patients who underwent radiosurgery for 15 intracranial metastases (9 dural-based and 6 parenchymal). Six patients had radiosurgery for solitary tumors and four had multiple tumors. The primary pathology was adenocarcinoma (eight patients) and small cell carcinoma (two patients). All patients received multimodality management for their primary tumor (including resection, radiation therapy, androgen deprivation therapy) and eight patients had evidence of systemic disease at time of radiosurgery. The mean tumor volume was 7.7 cm3 (range 1.1-17.2 cm3) and a median margin dose of 16 Gy was administered. Two patients had progressive intracranial disease in spite of fractionated partial brain radiation therapy (PBRT) prior to SRS. A local tumor control rate of 85% was achieved (including patients receiving boost, upfront and salvage SRS). New remote brain metastases developed in three patients (33%) and one patient had repeat SRS for tumor recurrence. The median survival after radiosurgery was 13 months and the 1-year survival rate was 60%. SRS was a well tolerated and effective therapy either alone or as a boost to fractionated radiation therapy in the management of patients with intracranial prostate carcinoma metastases. © 2009 Springer Science+Business Media, LLC.