98 research outputs found

    The importance of development of control processes and methods for urban bus services

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    This article aims to discuss the importance of the development of methodologies and control processes by the public power for the proper management of the urban bus system. It reflects on the idea of management control from the perspective of an operational, strategic and innovative perspective. It proposes a new look at the solution of negative externalities that arise in the urban environment of cities such as collisions, roadkill, works that will obstruct the roadbed and various events disrupting local traffic and directly impacting the mobility of public transport on tires. The theme is current, as it addresses the most problematic urban problem in the contemporary world, which is mobility. Thus, the article tells the experience of São Paulo and discusses a new control methodology for urban bus service./n

    A Statistical Approach for Modeling the Aging Effects in Li-Ion Energy Storage Systems

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    This paper presents a novel approach for the technical and economic assessment of Li-ion battery energy storage systems (BESS) in smart grids supported by renewable energy sources. The approach is based on the definition of a statistical battery degradation cost model (SBDCM), able to estimate the expected costs related to BESS aging, according to the statistical properties of its expected cycling patterns. This new approach can improve the assessment of the economical sustainability of BESSs in this kind of applications, helping in this way the planning processes in electricity infrastructures in presence of high penetration of intermittent renewable energy sources. The SBDCM proposed in this paper is a statistical generalization of a battery degradation model presented in the literature. The proposed approach has been validated numerically comparing the results with those of the deterministic model considering for the BESS a stochastic dataset of input signals. In order to test the usefulness of the proposed model in a real world application, the proposed SBDCM has been applied to the evaluation of the economic benefit associated to the development of distributed energy storage system scenarios in the Italian power system, aimed to provide ancillary services for supporting electricity market

    Brazil in Search of Transparency E-Gov

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    ABSTRACT/nThis article discusses the public administration strategy in the creation of electronic government (e-gov) Brazilian and interactivity of its population with this important way Shows trends and the consequences of its implementation, and the importance of its tools in disclosure and guidance to the population that public services and the relevance of the free software use as a government strategy. It also brings a reflection on the importance of transparency of government actions and commitment of resources of public administration. Also has the experience of São Paulo, in the urban transport sector in tires and the tools available to the user population. And it shows the valuable innovation to create Mobility Lab (MobLab), making the collaboration of the scientific community in city management./n

    Dispersion of the QT Interval in Subjects with Frequent Nonsustained Ventricular Arrhythmias and No Underlying Heart Disease: Arrhythmogenic Substrate or Mechanoelectrical Feedback of Arrhythmias?

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    Background: QT dispersion (QTd) on the ECG is thought to reflect the temporal and spatial inhomogeneity of repolarization in the underlying myocardium. In myocardial infarction, ischemia, and long QT syndromes, an increased QTd is associated with a propensity for malignant ventricular arrhythmias and sudden cardiac death. We investigated this feature of the repolarization process in subjects with frequent ventricular arrhythmias and structurally normal hearts. Methods: Forty-nine patients referred for frequent, nonsustained ventricular arrhythmias (45 ± 14 years, ×± SD, 61% female) had normal ventricular dimensions and function, no late potentials, and normal ECG. They were compared with 30 controls (42 ± 13 years, 50% female). QTd was measured as the difference between the longest and the shortest QT in the six precordial leads at a paper speed of 50 mm/s. Results: In patients, QTc was similar to that of controls: 395 ± 21 versus 386 ± 20. However, QTd was greater: 49 ± 20 ms versus 32 ± 14 ms, P < 001. Moreover, 18 patients (36%) had QTd exceeding 60 ms—a value superior to the mean normal value of 2 SD—compared to only 1 control (3%) (P < 0.01). Finally, patients with more frequent ventricular arrhythmias had larger QTd. Conclusions: In patients with frequent nonsustained ventricular arrhythmias and otherwise normal hearts, QT interval dispersion is increased. We speculate that, instead of representing a specific electrophysiological substrate of arrhythmias, QT dispersion in this specific population could result from arrhythmias themselves through a possible mechanoelectrical feedback

    What underlies NYHA class in elderly patients with heart failure? Role of diastolic dysfunction, functional mitral regurgitation and abnormal ventilation during exercise

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    Background - Color-Doppler ecocardiography and cardiopulmonary stress test are pivotal in the evaluation of patients with heart failure. Besides determining systolic function through left ventricular ejection fraction (EF), color-Doppler ecocardiography evaluates the presence and degree of functional mitral regurgitation and the severity of diastolic dysfunction. Moreover, in addition to the aerobic capacity indicated by peak O2 consumption, other parameters of cardiopulmonary stress have proven useful for diagnostic purposes, such as the peak VE/VCO2 ratio or ventilatory efficiency. Since in elderly patients with heart failure the functional impairment often is a combination of the effects of aging with those of disease, the relationship between symptoms, i.e. the NYHA class, ventricular pump function and aerobic performance is sometimes difficult to estabilish. Materials and methods - In 60 elderly with systolic heart failure (75+3 years, EF 30+6%), we correlated symptoms (i.e. NYHA class) with [1] degree of functional mitral regurgitation (FMR) determined by color-Doppler echocardiography; [2] degree of left ventricular diastolic dysfunction, measured by Doppler analysis of transmitralic and pulmonary veins flow; [3] VO2 e VE/VCO2 at peak exercise at cardiopulmonary test. Results - In all patients, NYHA class was only weakly related with EF and peakVO2, with wide overlap of individual values among patients with different NYHA class. Instead, we observed a tight relationship between NYHA class, FMR degree, and severity of diastolic dysfunction and VE/VCO2 ratio at peak exercise (p&lt;0.001), with a more evident partition among patients in different NYHA classes. Conclusions - In elderly heart failure patients, the reduced effort tolerance expressed by the NYHA classification is only weakly associated with reduced aerobic capacity and pump function, but rather is related with the presence of mitral regurgitation, left ventricular diastolic dysfunction, and a poor ventilatory efficiency during exercise

    A Complex Network Approach for the Estimation of the Energy Demand of Electric Mobility

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    We study how renewable energy impacts regional infrastructures considering the full deployment of electric mobility at that scale. We use the Sardinia Island in Italy as a paradigmatic case study of a semi-closed system both by energy and mobility point of view. Human mobility patterns are estimated by means of census data listing the mobility dynamics of about 700,000 vehicles, the energy demand is estimated by modeling the charging behavior of electric vehicle owners. Here we show that current renewable energy production of Sardinia is able to sustain the commuter mobility even in the theoretical case of a full switch from internal combustion vehicles to electric ones. Centrality measures from network theory on the reconstructed network of commuter trips allows to identify the most important areas (hubs) involved in regional mobility. The analysis of the expected energy flows reveals long-range effects on infrastructures outside metropolitan areas and points out that the most relevant unbalances are caused by spatial segregation between production and consumption areas. Finally, results suggest the adoption of planning actions supporting the installation of renewable energy plants in areas mostly involved by the commuting mobility, avoiding spatial segregation between consumption and generation areas

    Favourable effects of cardiovascular rehabilitation on funcional capacity and autonomic balance in elderly patients with heart failure

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    In 42 patients with chronic heart failure we evaluated left ventricular function, exercise capability and autonomic control before and 3 months after a program of cardiovascular rehabilitation. The results were analyzed separately for younger (Group 1, n=18, age 51±6 years) and older patients (Group 2, n=24, age 68±4 years), with comparable clinical characteristics and therapy. Before rehabilitation, compared to younger patients, Group 2 patients showed a lower exercise capability, a comparable left ventricular ejection fraction and similar high sympathetic activity at rest, with no response to regular breathing (= stimulation of cardiopulmonary receptors, i.e. parasympathetic challenge) and active standing (= sympathetic stimulation). After rehabilitation, in both groups a 20% improvement of exercise tolerance and aerobic performance was observed, as well as a slightly increase of left ventricular ejection fraction (about 10%), and a recovery in vagal and sympathetic responsiveness. Thus, in heart failure patients age does not hinder the favorable clinical and autonomic modulation induced by cardiovascular rehabilitation

    The Brief Strategic Treatment of Cardiophobia: A Clinical Case Study

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    AbstractMany individuals presenting to medical settings with heart-related symptoms for which no medical explanation is found might suffer from cardiophobia, but this condition is still poorly identified and addressed. This article presents a case of cardiophobia treated in an outpatient cardiac rehabilitation unit and, for the first time, describes the application of brief strategic therapy for the treatment of this condition. In the case reported, the first therapeutic encounter and the key elements of the strategic approach are described in detail with the aim to explain how brief strategic therapy works and how it can be used to identify and address cardiophobia-related behaviors. A 64-year-old male presented to cardiac rehabilitation reporting intense anxiety-provoking heart palpitations, and believing he was at risk of dying from a heart attack. After 3 sessions, an overall improvement in heart-related bodily sensations followed a decrease in the patient's continuous checking of his heartbeat and seeking reassurance—factors that were largely responsible for the persistence of the problem. Moreover, quantitative evaluation showed increased scores of mood state at the end of treatment. This improvement persisted at the 18-month follow-up. This case is an interesting example of how brief strategic therapy can contribute to the development of a new conceptual model for the diagnosis and treatment of cardiophobia. Still, more systematic research in the field is needed to prove the efficacy and effectiveness of this therapeutic approach on symptoms of heart-focused anxiety

    Millimeter Gap Contrast as a Probe for Turbulence Level in Protoplanetary Disks

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    Turbulent motions are believed to regulate angular momentum transport and influence dust evolution in protoplanetary disks. Measuring the strength of turbulence is challenging through gas line observations because of the requirement for high spatial and spectral resolution data, and an exquisite determination of the temperature. In this work, taking the well-known HD 163296 disk as an example, we investigated the contrast of gaps identified in high angular resolution continuum images as a probe for the level of turbulence. With self-consistent radiative transfer models, we simultaneously analyzed the radial brightness profiles along the disk major and minor axes, and the azimuthal brightness profiles of the B67 and B100 rings. By fitting all the gap contrasts measured from these profiles, we constrained the gas-to-dust scale height ratio Λ\Lambda to be 3.0−0.8+0.33.0_{-0.8}^{+0.3}, 1.2−0.1+0.11.2_{-0.1}^{+0.1} and ≥ 6.5{\ge}\,6.5 for the D48, B67 and B100 regions, respectively. The varying gas-to-dust scale height ratios indicate that the degree of dust settling changes with radius. The inferred values for Λ\Lambda translate into a turbulence level of αturb < 3×10−3\alpha_{\rm turb}\,{<}\,3\times10^{-3} in the D48 and B100 regions, which is consistent with previous upper limits set by gas line observations. However, turbulent motions in the B67 ring are strong with αturb ∼1.2 × 10−2\alpha_{\rm turb}\,{\sim}1.2\,{\times}\,10^{-2}. Due to the degeneracy between Λ\Lambda and the depth of dust surface density drops, the turbulence strength in the D86 gap region is not constrained.Comment: 13 pages, 7 figures, accepted for publication in Science China Physics, Mechanics & Astronom
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