Electrochemical impedance spectroscopy (EIS) is one of the most widely used techniques for battery monitoring and characterization. However, EIS measurement is a time-consuming process, since it must ...be performed after the battery relaxation time interval. In this paper, a method for performing fast broadband EIS during battery relaxation by compensating for the effect of the transient is proposed. The approach is based on the local rational method (LRM), which is a nonparametric frequency-domain system identification technique, and eliminates the need for long waiting time before starting the measurement process. The proposed approach is validated by numerical simulations and experiments, proving its capability of compensating the effect of the transient and outperforming other nonparametric techniques, such as the local polynomial method. In particular, experimental tests performed on a 18650 lithium-ion battery show that the proposed flexible LRM approach is capable of compensating the transient behavior and providing usable EIS estimates immediately after the battery discharge is finished. This behavior is demonstrated using a broadband multisine excitation signal of 20 s duration, spanning a frequency range from 50 mHz to 100 Hz.
RESUMO Balanço hídrico é uma análise realizada com base em estudos sobre as entradas e saídas de água de uma bacia hidrográfica, e que tem grande importância por identificar o regime hidrológico e as ...possibilidades de utilização da bacia. Neste trabalho foi realizado o balanço hídrico de uma secção de bacia hidrográfica localizada no oeste do Paraná, em uma área de plantio de eucaliptos para corte, obtendo-se também os valores para o escoamento superficial por meio do método racional.
ABSTRACT Water balance consists in an analysis carried out based on studies on the inflows and outflows of a hydrographic basin, which is fundamental to identify the hydrological regime and the possibilities of using this basin. This study aims to verify the water balance of a section of a hydrographic basin located in Western Paraná, Brazil, in addition to obtaining the values for runoff by the rational method.
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•Monitored rainfall-runoff responses from 13 urban and two forested watersheds.•Statistically compared measurements to current and novel hydrologic design models.•Greater uncertainty ...in peak flow predictions compared to runoff volume.•Different design models necessary for specific watershed / rainfall characteristics.
The need for resilient stormwater infrastructure is increasingly critical as urbanization and climate change continue to threaten water resources. Engineers and practitioners require reliable methodologies to estimate rainfall-runoff responses to adequately size and design sewer pipes and inlets, flood controls, and stormwater control measures (SCMs). The National Resource Conservation Service Technical Release 55 (often referred to as curve number CN method), Simple, and Rational methods are methodologies commonly implemented for such designs by regulatory agencies due to the limited inputs needed to estimate runoff; however, uncertainty is present in each model since they simplify actual hydrological processes. In this study, 13 urban and two forested watersheds were monitored, and their observed hydrologic responses were compared to modeled hydrologic responses utilizing the aforementioned methods. Significant differences in observed normalized runoff volumes (i.e., runoff coefficients) and normalized peak flow rates were found between watersheds with similar watershed characteristics and rainfall patterns, demonstrating the meticulous model inputs required to differentiate hydrologic responses between similar watersheds. A suite of alternative predictive models, informed by feature selection algorithms, were formulated and compared to the performance of standard methods. Results suggested that composite CN methods were the best predictors of event runoff volume across all watersheds (Nash Sutcliffe NSE and Kling Gupta Efficiencies KGE of 0.74 and 0.52, respectively), but were outperformed by the Simple method for watersheds with more than 45% impervious cover (NSE and KGE scores of 0.85 and 0.76, respectively). However, composite CN methods underestimated runoff volume from every watershed, a limitation that was intended to be addressed through the creation of the distributed CN method. In the distributed approach, runoff volume estimations were improved compared to the composite CN approach only when directly connected impervious area in the watershed was extremely high or extremely low. The multi-linear regression runoff volume model created herein did not outperform traditional runoff models except when rainfall depth was less than 12.5 mm (i.e., the storms for which traditional runoff volume estimation methods performed the worst). Uncertainty in modeled peak flow rate was substantially greater than for runoff volume (NSE and KGE scores between 0.48 – 0.55 and 0.39 – 0.67, respectively) across all methodologies. There is a continued need to develop more dependable estimates of peak flow which are critical to the design of pipes, flood routing, and hydrograph prediction. Overall, these results suggest one model is not optimal in all scenarios. Municipalities, regulatory agencies, and stormwater engineers should consider the adoption of multiple methodologies and use guidance from the results herein to provide recommendations as to when each model is most applicable.
The main goal of this paper is to discover some new analytical solutions of a fractional form of the Bogoyavlensky–Konopelchenko equation via two new analytical schemes. This model is considered as a ...particular case of (2 + 1)–dimensional version of the well–known KdV equation where it describes the interaction between the Riemann wave propagating and the long-wave propagation along the x,y–axises. An efficient fractional derivative called Atangana–Baleanu-Riemann derivative is utilized to convert the standard form of the model into a nonlinear fractional PDE with an–integer order. The basic idea in these methods is to use a new variable to transform the form of the equation into a nonlinear equation with ordinary derivatives. The novelty of the present paper is that the new solutions determined by applying these two powerful analytical methods can not be found in previous articles. Several two and three-dimensional figures have been depicted to illustrate the dynamic behavior of the acquired solutions. Another advantage of these two methods is their applicability in solving similar models using this fractional derivative operator.
The aim of this study is to investigate the response of the rational method in flood hazard assessment in Potamia watershed of Thasos island, with climate data from Regional Climate Models. The ...precipitation intensity–duration–frequency (IDF) curves used were calculated using available EURO-CORDEX 0.11 regional climate model simulations, under the RCP8.5 scenario. The Corine Land Cover dataset was utilized for the determination of the runoff coefficient of the watershed and geomorphological and hydrographic characteristics are calculated using a Geographic Information System software. A comparison against actual flood events of the period 1991–2019, as mapped with satellite Synthetic Aperture Radar (SAR) imagery, is also carried out.
Peninsular Spain.
There is strong evidence that climate change has produced a decrease in precipitation combined with an increased frequency, intensity and magnitude of high-intensity storm events in ...Peninsular Spain. Such events have been particularly recurrent on the Spanish Mediterranean coast in recent years. This study’s first objective is to update the trends in the magnitude and seasonality of precipitation in Spain from 1951 to 2019 at different time scales. Secondly, we analyse how extreme precipitation events recorded in recent years can modify water infrastructure design flows. A QGIS plugin was programmed using Python to calculate the design flows in accordance with the methodologies legally established in Spain.
The results confirm the decreasing trend in annual precipitation in most of the Spanish territory. This decrease was particularly significant during March and June. Moreover, the average increases of around 30–40 % in design flows, which reached double the values obtained in the reference period of 1951–1990 in some basins, confirm the relevance of incorporating high-intensity storm events recorded in recent years into flow calculations in Peninsular Spain. Design flows obtained without using the most recent rainfall data can be underestimated, with profound risk implications. Therefore, there is a sufficient technical basis to draw attention to this problem and recommend its formal consideration by competent authorities.
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•Rainfall trends in Peninsular Spain from 1951 to 2019 have been analysed.•Mann-Kendall test was used to analyse rainfall trends at different time scales.•A specific QGIS plugin has been developed to calculate design flows.•Recent high intensity storms can double design flows.
Two‐dimensional biharmonic boundary‐value problems are considered by the linear barycentric rational method, the unknown function was approximated by the barycentric rational function. For the ...biharmonic equation, we change the biharmonic equation into the two Poisson equations by depression of order. The linear equations of discrete the biharmonic equation was changed into matrix form. For the basis of barycentric rational function, we present the convergence rate of linear barycentric rational method for biharmonic equation by depression of order. At last, several numerical examples are provided to validate the theoretical analysis.
In this paper, firstly a rational one-parameter family of Falkner-type explicit methods is presented for directly solving numerically special second order initial value problems in ordinary ...differential equations. The proposed family of methods has second algebraic order of convergence. Imposing that the principal term of the local truncation error of the proposed family vanishes, we get an expression for the free parameter at the grid point (xn, yn). By substituting this value of the free parameter in the family, a new rational third order method is obtained. Further, by combining the third order method with any member of the second order family, their variable step-size formulation as an embedded pair is considered. Some numerical experiments are given to illustrate the performance and efficiency of the proposed methods.
From the origins of hydrology, the time of concentration, tc, has conventionally been tackled as a constant quantity. However, theoretical proof and empirical evidence imply that tc exhibits ...significant variability against rainfall, making its definition and estimation a hydrological paradox. Adopting the assumptions of the Rational method and the kinematic approach, an effective procedure in a GIS environment for estimating the travel time across a catchment's longest flow path is provided. By application in 30 Mediterranean basins, it is illustrated that tc is a negative power function of excess rainfall intensity. Regional formulas are established to infer its multiplier (unit time of concentration) and exponent from abstract geomorphological information, which are validated against observed data and theoretical literature outcomes. Besides offering a fast and easy solution to the paradox, we highlight the necessity of implementing the varying tc concept within hydrological modelling, signalling a major shift from current engineering practices.
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