Greenhouse gas emissions convergence in Spain: evidence from the club clustering approach

Environmental Science and Pollution Research - This study examines the convergence of greenhouse gas emissions per capita across the 19 Spanish regions using the Phillips-Sul club convergence...     

Biocapacity convergence clubs in Latin America: an analysis of their determining factors using quantile regressions

Latin America experiences an increasing urban primacy index and a rapid expansion of the financial system, putting direct pressure on the demand for resources to satisfy the consumption of large cities. We investigate the convergence of per capita biocapacity in 16 Latin America countries and evaluate the factors that influence its evolution over time. Specifically, we analyze the impact of the urban primacy index, economic progress, and the financial globalization index on the convergence of per capita biocapacity. We use the methodological framework developed by Phillips and Sul Econometrica 75:1771-1855, (2007) to analyze the convergence and the formation of convergence clubs of biocapacity during 1970–2017. The findings indicate that the countries of the region do not share a common trend of biocapacity, although they are grouped into five converging clubs. Biocapacity transition analysis reveals that countries have heterogeneous transition pathways between them. Using marginal effects, we find that the urban primacy index and economic progress reduce the biocapacity. The effect of the financial globalization index on biocapacity is not conclusive. The quantile regressions reveal that quantiles’ impact of the urban primacy index and financial globalization on per capita biocapacity is heterogeneous. However, the effect of economic progress on biocapacity that predominates among quantiles is positive. The adoption of common policies among the countries that form the converging clubs could improve the effectiveness of pro-environmental policies and promote the achievement of the Sustainable Development Goals related to environmental quality.

     

Regional convergence of energy-environmental efficiency: from the perspective of environmental constraints

Environmental Science and Pollution Research - This paper conducts a convergence analysis on the energy-environmental efficiency to explore the differences between regions that reflect the...     

Convergence of renewable energy consumption in the EU-15: evidence from stochastic and club convergence tests

Environmental Science and Pollution Research - This paper investigates the convergence of per capita renewable energy consumption across 15 core EU member countries over the period 1990–2018....     

Parametric and non-parametric convergence analysis of electricity intensity in developed and developing countries

Environmental Science and Pollution Research - This paper examines the pattern of convergence in electricity intensity in a sample of 79 countries. We apply the residual augmented least squares...     

Energy intensity convergence in Iranian provinces: evidence from energy carriers’ consumption intensity

Environmental Science and Pollution Research - Investigating the energy intensity convergence in Iran, as a country with very high energy intensity in the world, is important in order to assess...     

EU-28’s progress toward the 2020 renewable energy share: a club convergence analysis

Environmental Science and Pollution Research - This paper assesses the convergence of the EU-28 countries toward their common goal of 20% in the renewable energy share indicator by year 2020. The...     

Operator-splitting procedures for reactive transport and comparison of mass balance errors

Operator-splitting (OS) techniques are very attractive for numerical modelling of reactive transport, but they induce some errors. Considering reactive mass transport with reversible and irreversible reactions governed by a first-order rate law, we develop analytical solutions of the mass balance for the following operator-splitting schemes: standard sequential non-iterative (SNI), Strang-splitting SNI, standard sequential iterative (SI), extrapolating SI, and symmetric SI approaches. From these analytical solutions, the operator-splitting methods are compared with respect to mass balance errors and convergence rates independently of the techniques used for solving each operator. Dimensionless times, NOS, are defined. They control mass balance errors and convergence rates. The following order in terms of decreasing efficiency is proposed: symmetric SI, Strang-splitting SNI, standard SNI, extrapolating SI and standard SI schemes. The symmetric SI scheme does not induce any operator-splitting errors, the Strang-splitting SNI appears to be O(N2OS) accurate, and the other schemes are first-order accurate.     

模糊神经网络控制在污水处理中的应用研究

对模糊神经网络（FNN）技术应用于污水处理进行了研究，提出了一个具有五层的模糊神经网络控制器，仿真实验表明，该控制系统具有很强的鲁棒性与容错性。该控制器能够自动调整隶属度函数、动态优化控制规则，将其应用于溶解氧控制和出水水质预测，结果表明可以快速、有效地使溶解氧浓度达到期望值，实际出水水质预测结果也具有很好的收敛性和预测精度。     

模糊神经网络控制在污水处理中的应用研究

对模糊神经网络(FNN)技术应用于污水处理进行了研究,提出了一个具有五层的模糊神经网络控制器,仿真实验表明,该控制系统具有很强的鲁棒性与容错性.该控制器能够自动调整隶属度函数、动态优化控制规则,将其应用于溶解氧控制和出水水质预测,结果表明可以快速、有效地使溶解氧浓度达到期望值,实际出水水质预测结果也具有很好的收敛性和预测精度.     

化学-生物絮凝工艺类神经网络模型比较研究

在化学-生物絮凝工艺中试研究的基础上,分别建立了基于BP类神经网络的多输入多输出（MIMO）模型与多输入单输出（MISO）模型。应用化学生物絮凝工艺中试6个不同工况的实测数据对2个模型进行训练,均表现出很好的收敛性。通过另外2个中试工况的实测数据对模型预测性能进行测试,MISO模型对化学-生物絮凝反应器出水的COD、TP和SS的预测相对误差均低于MIMO模型,其预测相对误差均在9%以下。研究表明,MISO模型是一个很易使用的建模工具,能很好地预测化学-生物絮凝工艺出水水质。     

印染废水水解酸化处理中填料式反应器与UASB反应器的比较

根据印染废水的特点和印染废水处理工程实例,从适用性、与其他工艺的衔接、工程造价、运行费用及水解效果等方面对UASB水解酸化反应器和填料式水解酸化反应器进行比较研究。研究表明,UASB水解酸化反应器在适用性和工程造价两个方面具有一定的缺陷;但是UASB水解酸化反应器对印染废水中COD、SS和色度去除率能够分别达到50％、73％和75％,明显高于填料式水解酸化反应器;且UASB水解酸化反应器每降解1kgCOD所需电量为（0．23±0．05）kW·h,优于填料式水解酸化反应器。     

印染废水水解酸化处理中填料式反应器与UASB反应器的比较

根据印染废水的特点和印染废水处理工程实例,从适用性、与其他工艺的衔接、工程造价、运行费用及水解效果等方面对UASB水解酸化反应器和填料式水解酸化反应器进行比较研究。研究表明,UASB水解酸化反应器在适用性和工程造价两个方面具有一定的缺陷;但是UASB水解酸化反应器对印染废水中COD、SS和色度去除率能够分别达到50%、73%和75%,明显高于填料式水解酸化反应器;且UASB水解酸化反应器每降解1 kg COD所需电量为(0.23±0.05)kW·h,优于填料式水解酸化反应器。     

Characterization of atmospheric contaminant sources using adaptive evolutionary algorithms

The characteristics of an unknown source of emissions in the atmosphere are identified using an Adaptive Evolutionary Strategy (AES) methodology based on ground concentration measurements and a Gaussian plume model. The AES methodology selects an initial set of source characteristics including position, size, mass emission rate, and wind direction, from which a forward dispersion simulation is performed. The error between the simulated concentrations from the tentative source and the observed ground measurements is calculated. Then the AES algorithm prescribes the next tentative set of source characteristics. The iteration proceeds towards minimum error, corresponding to convergence towards the real source.The proposed methodology was used to identify the source characteristics of 12 releases from the Prairie Grass field experiment of dispersion, two for each atmospheric stability class, ranging from very unstable to stable atmosphere. The AES algorithm was found to have advantages over a simple canonical ES and a Monte Carlo (MC) method which were used as benchmarks.     

Spatiotemporal coupling measurement of industrial wastewater discharge and industrial economy in China

With the industrial-level panel data on total output and wastewater discharge over the period of 1997 to 2018, this paper employs GIS and ESDA methods to empirically investigate the spatial relationship between industrial total output and wastewater discharge. In this paper, we empirically examine whether and how industrial wastewater discharge in a particular province may affect the wastewater discharge in its neighboring provinces. Results suggest that provinces (municipalities) with large-scale industrial sewage discharge are located along riversides and coastal areas and these discharges then gradually distribute to coastal, central, and western areas. Results also show a strong spatial autocorrelation of industrial wastewater discharge between the observed local province and its neighboring provinces which is increasing over time. In addition, there is also a significant spatial spillover effect of industrial wastewater discharge among neighboring provinces in China’s eastern and central regions, indicating a structural convergence of high-pollution industries.

     

Responses of juvenile European flounder (Platichthys flesus) to multistress in the Vilaine estuary, during a 6-month survey

Physiological and genetic responses of age 0+ Platichthys flesus were investigated in the eutrophicated and moderately contaminated Vilaine estuary, during a 6-month survey. The main objective of this study was to explore the biological responses of fishes during their juvenile period in an estuarine system in order to detect a possible selective pressure induced by the environmental stress. Our results showed a general convergence in physiological responses along the survey: an increase in genotoxicity was associated with an increase in mRNA expression of ATPase and betaine homocysteine methyltransferase. These results could suggest an increase of cellular damage, energetic request, and detoxification rate related to the growing exposure time to stress. Considering the aging of the cohort, the genetic characteristics of the Vilaine flounder cohort came closer to the one observed in a highly stressed system, the Seine estuary, suggesting a potential selective pressure mainly induced by the chemical stress.     

Variable K-theory model for the dispersion of air pollutants in low-wind conditions in the surface-based inversion

A variable K-model has been proposed for the dispersion in low winds in the surface-based inversion by expressing the eddy diffusivities as a linear function of downwind distance from the source. The resulting partial differential equation with variable coefficients along with the physically relevant boundary conditions is solved analytically. For the accuracy of the so-obtained solution, an analysis of the convergence and error estimation has been carried out. It is shown that the series converges absolutely. An upper bound for the error based on the partial sum of the series is estimated and it is described that the error tends to zero as the number of terms in the expansion are sufficiently large.The solution has been used to simulate the field tracer data sets collected from Hanford and IIT diffusion experiments in stable and unstable conditions, respectively. It predicts 41% cases in stable and 35% cases in unstable conditions within a factor of two to observations.     

Characterizing the uncertainty of pesticide leaching in agricultural soils

A Monte-Carlo numerical simulation procedure for making regional assessments of pesticide leaching has been developed. This procedure uses probability density functions for organic matter, field capacity, and wilting point developed from information on approximately 3000 soils. Variations in climatic conditions were incorporated by random selection of yearly rainfall data. The procedure was demonstrated for aldicarb applied to corn grown in Ohio. A total of 2000 parameter sets were evaluated using the unsaturated zone model PRZM. The simulation results indicated that convergence of the 90th, 95th, and 99th percentiles for movement past 0.3, 0.6, 0.9, and 1.5 m was obtained after 500 simulations. The relative uncertainty associated with these percentiles was approximately 50% after 1500 simulations. The downward movement of aldicarb residues was most sensitive to changes in field capacity. These simulations, coupled with additional soil-specific simulations, indicated no significant movement of aldicarb residues beyond 1.8 m for applications to Ohio corn.     

A numerical model for transient-hysteretic flow and solute transport in unsaturated porous media

A two-dimensional flow and transport model was developed for simulating transient water flow and nonreactive solute transport in heterogeneous, unsaturated porous media containing air and water. The model is composed of a unique combination of robust and accurate numerical algorithms for solving the Richards', Darcy flux, and advection-dispersion equations. The mixed form of Richards' equation is solved using a finite-element formulation and a modified Picard iteration scheme. Mass lumping is employed to improve solution convergence and stability behavior. The flow algorithm accounts for hysteresis in the pressure head-water content relationship. Darcy fluxes are approximated with a Galerkin and Petrov-Galerkin finite-element method developed for random heterogeneous porous media. The transport equation is solved using an Eulerian-Lagrangian method. A multi-step, fourth-order Runge-Kutta, reverse particle tracking technique and a quadratic-linear interpolation scheme are shown to be superior for determining the advective concentration. A Galerkin finite-element method is used for approximating the dispersive flux. The unsaturated flow and transport model was applied to a variety of rigorous problems and was found to produce accurate, mass-conserving solutions when compared to analytical solutions and published numerical results.     

An analysis of short-range dispersion experiments on the windward slope of an isolated hill

This paper describes short range dispersion experiments carried out on the upwind slope of Blashaval, an isolated, roughly conical hill on the island of North Uist, Scotland, in conditions close to neutral stability. The trials were adjunct to a larger experiment which investigated the influence of the hill upon the mean wind and turbulence, reported by Mason and King (1985, Q. Jl R. met. Soc.111, 617–640). The purpose of the tracer releases was to see if the dispersion could be explained in terms of currents knowledge of flow over hills. The results from experiments conducted on the forward slope of the hill in an area where the flow strealines were diverging in the horizontal, converging in the vertical, showed that the plume was brought close the surface. One plume appeared to encounter a zone of horizontal convergence. The observations are also compared with a suitably adapted random walk model of dispersion.