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This paper presents a newly developed voltage and reactive power control device, the coordinated Q -V controller (CQVC), for a multimachine steam power plant (SPP). The requirements for the new controller are defined based on identified inadequacies of manual Q-V control. The controller uses a feed-forward correction signal based on the application of the sensitivity matrix at a power plant level. It is designed and its performance initially assessed using the Matlab/Simulink environment. The performed simulations show that all the primary design objectives are met. The Q-V controller maintains the voltage at the SPP busbar with a certain droop characteristic during slow voltage changes in the power system whilst also maintaining equal per unit reactive power sharing among the SPP generators. This ensures that the power system fully benefits from all generating units during system perturbations. The performance of the designed CQVC is validated by comparing simulation results with measured responses obtained from a real CQVC installed at a SPP.

This paper discusses the concept of 'sustainable water services' and suggests a multicriteria method to assess it. Although conceptual discussions around this notion are often confined to the triple bottom line (TBL) classification, it seems that the TBL approach does not provide the suitable framework to measure water services sustainability. It is argued that assets (or technical) and governance aspects are also indispensable dimensions. After revisiting the concept in broader terms, several criteria and metrics are suggested to operationalize and quantify the sustainability level of urban water services. To aggregate the numerous aspects that are relevant in this scope a multicriteria decision analysis approach is proposed. Furthermore, to illustrate the real-world application of the method, a multicriteria model applicable to the case of Portugal was developed and calibrated with the input of a decision-maker with extensive experience in the sector. With the suggested framework it is possible to assess the global sustainability level of the water services (e.g. of each utility) and also the performance in each particular dimension ('social', 'environmental', 'economic', 'governance' and 'assets').

This paper analyses the relationship among economic growth, energy use and carbon dioxide (CO2) emissions in Israel over the period 1971–2006. Results of unit root tests show that all variables are integrated of order one. Causality results suggest that real gross domestic product (GDP) drives both energy use and CO2 emissions. Forecast error variance decompositions (FEVDs) evidence that the errors in real per capita GDP are mainly due to uncertainty in GDP itself, while the errors in predicting the energy consumption and the CO2 emissions are sensitive to disturbances in the other two equations. The FEVDs show that forecast errors in real per capita GDP are mainly due to uncertainty in GDP itself, the errors in predicting the energy use are sensitive to disturbances both in the GDP and in CO2 equations, while the forecast errors in CO2 emissions should be essentially connected to emissions itself. Finally, the vector autoregression (VAR) forecast represents an improvement in simpler forecasts in more tha...

This paper presents details of the practical implementation of a coordinated reactive power-voltage controller (CQVC) developed for a multi-machine steam power plant. The CQVC performs optimal coordination of the synchronous generators' reactive power outputs in order to maintain the total reactive power delivered by a steam power plant (SPP) or the voltage at a steam power plant HV busbar. This is required to achieve slow preventive control of generated reactive powers in order to maximize reactive power reserves along with slow high side voltage control. The CQVC is designed to act through existing automatic voltage regulator inputs, thus no modification of an existing excitation system was made. In order to increase the robustness to changes in operating conditions and to achieve the desired shape of the reactive power response, the two-step predictor corrector method is implemented. A newly developed algorithm for steady state detection ensures non-interference of reactive power voltage control with excitation system response. The paper also presents practical design solutions to overcome limitations posed by application to a real system. Acceptance and functional tests carried out during the commissioning of the CQVC are also discussed in this paper.

This paper describes newly designed coordinated Q-V controller (CQVC), for a multi machine steam power plant (SPP). After giving design specification and theoretical background for designed CQVC, the paper focuses on practical implementation and performance of commissioned CQVC. Following several innovations are introduced in design of controller: sensitivity matrix concept is applied at plant level to decouple generators connected to the same busbars, steady state detection is used for the decoupling between synchronous generator dynamics and network dynamics, the response is shaped by the use of predictor corrector method. Issues related to practical implementation of CQVC in SPP such as online estimation of network reactance and generators' reactive power capability are also addressed and discussed in the paper. Finally the paper shows examples of recorded plant responses after commissioning of the proposed controller.

AbstractThe tropical forests of the Congo Basin and Gulf of Guinea harbor some of the greatest terrestrial and aquatic biological diversity in the world. However, our knowledge of the rich biological diversity of this region and the evolutionary processes that have shaped it remains limited, as is our understanding of the capacity for species to adapt or otherwise respond to current and projected environmental change. In this regard, research efforts are needed to increase current scientific knowledge of this region's biodiversity, identify the drivers of past diversification, evaluate the potential for species to adapt to environmental change and identify key populations for future conservation. Moreover, when evolutionary research is combined with ongoing environmental monitoring efforts, it can also provide an important set of tools for assessing and mitigating the impacts of development activities. Building on a set of recommendations developed at an international workshop held in Gabon in 2011, we highlight major areas for future evolutionary research that could be directly tied to conservation priorities for the region. These research priorities are centered around five disciplinary themes: (1) documenting and discovering biodiversity; (2) identifying drivers of evolutionary diversification; (3) monitoring environmental change; (4) understanding community and ecosystem level processes; (5) investigating the ecology and epidemiology of disease from an evolutionary perspective (evolutionary epidemiology). Furthermore, we also provide an overview of the needs and priorities for biodiversity education and training in Central Africa.

The aim of this paper is to analyze the relationship among economic growth, carbon dioxide emissions, and energy use for 19 APEC countries over the 1960–2013 years. Using a panel VAR technique, a three-variable VAR is estimated. Empirical findings illustrate that no causal relationship emerges between real GDP and energy use. Thus, our empirical evidence is in line with the “neutrality hypothesis.” Moreover, panel cointegration tests show that a long-run equilibrium relationship is questionable for the APEC countries. Granger causality analyses confirm our previous results, since in nine countries any causal relationship between GDP and energy is found.

This dataset contains a land use change scenario (2050) for Scotland within the scope of a SSP1 - Low emissions scenario (Shared Socio-Economic Pathways). For achieving a low-emissions scenario, simulated land use change targeted woodland expansion (including silvo-arable and silvo-pastoral) and decreased grazing intensity, both land use changes also aimed at benefitting four aspects of ecosystem services: carbon storage through tree planting, emission reduction through deintensification, biodiversity enhancement through tree planting, and pollination to support food production. The 2019 baseline land use map at 100m resolution, was created by combining the Land Cover Map 2019 (Morton et al, 2020), estimations of stocking rates from IACS (Wardell-Johnson, 2022), and grazing conservation thresholds (Chapman, 2007; FAS, 2021). The land use scenario map was created using the SLM-OptionsTool, a land use change tool for Ecosystem Services based on the LandSFACTS model (Castellazzi et al, 2010). The attached land use scenario map for 2050 is not an optimised result, but it is only one possibility among others that meets all the constraints stipulated for the scenario. For a detailed description of the scenario refer to the following web storymap : https://storymaps.arcgis.com/stories/c3d3feff85f14460b6c973127089d6f9 This analysis was conducted as part of the Land use Transformations (https://landusetransformations.hutton.ac.uk/) project (JHI-C3-1) in the Scottish Government funded Strategic Research Programme 2022-27. The exact licence for this dataset is currently being finalised. When ready, the dataset will be uploaded as a new version.