169 research outputs found

    Transport energy consumption in mountainous roads. A comparative case study for internal combustion engines and electric vehicles in Andorra

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    This paper analyses transport energy consumption of conventional and electric vehicles in mountainous roads. A standard round trip in Andorra has been modelled in order to characterise vehicle dynamics in hilly regions. Two conventional diesel vehicles and their electric-equivalent models have been simulated and their performances have been compared. Six scenarios have been simulated to study the effects of factors such as orography, traffic congestion and driving style. The European fuel consumption and emissions test and Artemis urban driving cycles, representative of European driving cycles, have also been included in the comparative analysis. The results show that road grade has a major impact on fuel economy, although it affects consumption in different levels depending on the technology analysed. Electric vehicles are less affected by this factor as opposed to conventional vehicles, increasing the potential energy savings in a hypothetical electrification of the car fleet. However, electric vehicle range in mountainous terrains is lower compared to that estimated by manufacturers, a fact that could adversely affect a massive adoption of electric cars in the short term.Peer ReviewedPostprint (author’s final draft

    Linear Precoding performance analysis in a Broadband satellite system with a 2-color dual-polarization reuse scheme

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    The potential of Joint Multiuser Processing in multi-beam satellite systems is assessed in this paper and proved to be a potential attractive alternative to current systems. The present contribution aims at investigating linear precoding techniques over an accurate multi-beam architecture modeling and system characterization. Power and precoder design problems are approached through well-known linear precoding techniques such as Zero Forcing (ZF) and Regularized-ZF. A dual-polarization 2-color reutilization scheme is considered in combination with precoding techniques. Results show a total throughput improvement of +22% achieved by ZF and +38% considering R-ZF, with respect to a conventional 4-color reuse scheme scenario

    Next Generation High Throughput Satellite System

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    This paper aims at presenting an overview of the state-of-the-art in High Throughput Satellite (HTS) systems for Fixed Satellite Services (FSS) and High Density-FSS. Promising techniques and innovative strategies that can enhance system performance are reviewed and analyzed aiming to show what to expect for next generation ultra-high capacity satellite systems. Potential air interface evolutions, efficient frequency plans,feeder link dimensioning strategies and interference cancellation techniques are presented to show how Terabit/s satellite myth may turn into reality real soon

    LENDING ROBOTS AND HUMAN CROWDS: INTEREST RATE DETERMINATION ON A REVERSE AUCTION PLATFORM

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    We analyze the determinants of the level of interest rates related to business loans traded on digital crowdlending platforms. We consider one of the leading platforms in France and collect-ed original data on all the projects financed via this platform. On that platform, interest rates are set by the crowd of investors through a reverse auction process. We show that the loan characteristics and the scoring provided by the platform significantly influences the interest rate. However, though financial ratios are used traditionally to estimate credit risk, those ratios do not exhibit significant influence. Besides, we analyze the impact of the recent implementation of an automated auction mechanism. This implementation seems to have a large impact on both auction duration and on the determinants of interest rate. This suggests that use of a robot im-pacts on price and saving allocation on this platform-based credit market

    Right heart echocardiographic variables and prediction of clinical severity in dogs with pulmonary stenosis

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    Background: Pulmonary stenosis (PS) usually is evaluated using echocardiography. A multiparametric approach, in addition to the maximum pressure gradient (PG), might be indicated to better characterize PS severity and address its management. Hypothesis/objectives: Our hypothesis was that right heart size and function are associated with echocardiographic and clinical severity of pulmonary stenosis in dogs. Animals: Client-owned dogs with PS. Methods: Prospective, multicenter, observational study. Enrolled dogs underwent complete echocardiographic examination. Associations among right heart echocardiographic variables, PS transvalvular PG >80 mm Hg and presence of clinical signs (exercise intolerance, syncope, right-sided congestive failure, or some combination of these) were assessed using logistic regression analysis. Results: Eighty-eight dogs with PS. Twenty-eight dogs were symptomatic. Increased right ventricular end-diastolic free wall thickness (odds ratio [OR] > 100; 95% confidence interval [95%CI], 50- > 100; P = .01) and decreased aorta-to-pulmonary artery velocity time integral ratio (OR, 80 mm Hg. Decreased tricuspid annular plane systolic excursion (OR, 0.35; 95%CI, 0.15-0.77; P = .01) and increased right ventricular end-diastolic area (OR, 1.4; 95%CI, 1.08-2.02; P = .01) were independently associated with clinical severity. Conclusion and clinical importance: Structural and functional right heart echocardiographic variables are associated with echocardiographic and clinical severity in dogs with PS. A multiparametric approach is advised to better assess PS severity

    Evaluation of the integration of P recovery, polyhydroxyalkanoate production and short cut nitrogen removal in a mainstream wastewater treatment process

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    Wastewater treatment systems are nowadays evolving into systems where energy and resources are recovered from wastewater. This work presents the long term operation of a demo-scale pilot plant (7.8 m(3)) with a novel configuration named as mainstream SCEPPHAR (ShortCut Enhanced Phosphorus and polyhydroxyalkanoate (PHA) Recovery) and based on two sequencing batch reactors (R1-HET and R2-AUT). This is the first report of an implementation at demo scale and under relevant operational conditions of the simultaneous integration of shortcut nitrification, P recovery and production of sludge with a higher PHA content than conventional activated sludge. An operating period under full nitrification mode achieved successful removal efficiencies for total N, P and CODT (86 +/- 12%, 93 +/- 9% and 79 +/- 6%). In the following period, nitrite shortcut (with undetectable activity of nitrite oxidising bacteria) was achieved by implementing automatic control of the aerobic phase length in R2-AUT using ammonium measurement andoperating at a lower sludge retention time. Similar N, P and CODT removal efficiencies to the full nitrification period were obtained. P-recovery from the anaerobic supernatant of R1-HET was achieved in a separate precipitator by increasing pH and dosing MgCl2, recovering an average value of 45% of the P in the influent as struvite precipitate, with a peak up to 63%. These values are much higher than the typical values of sidestream P-recovery (12%). Regarding PHA, a percentage in the biomass in the range 6.9-9.2% (gPHA.g(-1)TSS) was obtained

    Prasinovirus distribution in the Northwest Mediterranean Sea is affected by the environment and particularly by phosphate availability

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    AbstractNumerous seawater lagoons punctuate the southern coastline of France. Exchanges of seawater between these lagoons and the open sea are limited by narrow channels connecting them. Lagoon salinities vary according to evaporation and to the volume of freshwater arriving from influent streams, whose nutrients also promote the growth of algae. We compared Prasinovirus communities, whose replication is supported by microscopic green algae, in four lagoons and at a coastal sampling site. Using high-throughput sequencing of DNA from a giant virus-specific marker gene, we show that the environmental conditions significantly affect the types of detectable viruses across samples. In spatial comparisons between 5 different sampling sites, higher levels of phosphates, nitrates, nitrites, ammonium and silicates tend to increase viral community richness independently of geographical distances between the sampling sites. Finally, comparisons of Prasinovirus communities at 2 sampling sites over a period of 10 months highlighted seasonal effects and the preponderant nature of phosphate concentrations in constraining viral distribution

    Calidad de servicio y satisfacción de los usuarios en la municipalidad distrital baños del inca, 2022

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    La presente investigación se realizó con el objetivo de determinar la relación que existe entre la calidad de servicio y la satisfacción de los usuarios en la Municipalidad Distrital Baños del Inca, 2022. El estudio es de tipo no experimental, transversal, y de alcance correlacional. La población estuvo conformada por los usuarios de la Municipalidad Distrital de Baños del Inca; en este sentido, la población es infinita, aplicando muestreo probabilístico aleatorio simple, se analizó a 384 usuarios. Como instrumentos se aplicaron 2 cuestionarios para las variables involucradas. Los resultados de la investigación indican que existe relación entre la calidad de servicio y la satisfacción del usuario, debido al coeficiente de correlación de Spearman, (Rho = 0.365, Sig. (bilateral) = 0.000 < p= 0.05). Además, que existe correlación positiva débil entre la dimensión fiabilidad y satisfacción del usuario, considerando (Rho = 0.308, Sig. (bilateral) = <0.000 < p= 0.05), existe correlación positiva débil entre la dimensión seguridad y satisfacción del usuario, como resultado del (Rho = 0.294, Sig. (bilateral) = <0.000 < p= 0.05), existe correlación positiva débil entre la dimensión empatía y satisfacción del usuario, considerando el (Rho = 0.264, Sig. (bilateral) = <0.000 < p= 0.05), existe correlación positiva débil entre la dimensión elementos concretos y satisfacción del usuario, esto debido al (Rho = 0.233, Sig. (bilateral) = <0.000 < p= 0.05) y existe correlación positiva débil entre la capacidad de respuesta y satisfacción del usuario, esto debido al (Rho = 0.233, Sig. (bilateral) = <0.000 < p= 0.05)

    Introduction to special section: Balancing, restoration, and palinspastic reconstruction

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    Methods to quantify deformation and reverse the process of strain as a mode to illustrate geologic evolution through time have been previously used for a number of decades. Early efforts on the quantification of bed reconstruction were completed either by manually weighing the sections on delicate balances and obtaining the average height and thickness of strata to be reconstructed by applying a scale factor (Chamberlin, 1910), or by hand-drafting sections with conserved bed length between the folded and faulted sedimentary layers, mainly in a 2D cross section (Bally et al., 1966; Dahlstrom, 1969) or map framework (Dennison and Woodward, 1963). Cross-section techniques initially applied to contractional thrust and fold belts and have proven useful in other structural settings, such as extensional and inverted domains. Development of 3D techniques enabled the analysis of strike-slip and salt tectonics where out-of-plane changes of rock volume could be addressed. Through the years, the widespread application of these techniques to predict fault and horizon geometry at depth has generated newer approaches and more sophisticated algorithms, and it has also demonstrated the potential of structural modeling techniques (e.g., construction of balanced sections, palinspastic reconstruction, kinematic and geomechanical restoration, and forward modeling) in reducing the risk and uncertainty associated with the interpretation of geophysical/geological dat

    Detection and characterization of single nanoparticles by interferometric phase modulated ellipsometry

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    We introduce a new measurement system called Nanopolar interferometer devoted to monitor and characterize single nanoparticles which is based on the interferometric phase modulated ellipsometry technique. The system collects the backscattered light by the particles in the solid angle subtended by a microscope objective and then analyses its frequency components. The results for the detection of 2 ÎĽm and 50 nm particles are explained in terms of a cross polarization effect of the polarization vectors when the beam converts from divergent to parallel in the microscope objective. This explanation is supported with the results of the optical modelling using the exact Mie theory for the light scattered by the particles
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