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Abstract Background An accurate assessment of the carbon budget is a crucial part of projecting future climate change and its impact on ecosystems. Grasslands foster multiple ecological functions including support for wild animals and livestocks. Herbivores intake forage biomass carbon, then digest and metabolize, and finally retain some carbon. The carbon processes have not been well quantified, resulting in uncertainties in the estimation of regional carbon budgets for grassland ecosystems. Methods An animal metabolic carbon flux model was developed for herbivores in the Three‐Rivers Headwaters region of China. The forage intake and metabolic carbon rates were estimated through metabolic body weight and daily digested measures for the main herbivore species. Results The carbon intake was 5.52 Tg C year−1 (45%) from partial aboveground biomass (12.2 Tg C year−1), in which 39.31% was released into the atmosphere by respiration CO2, 43.77% was returned to the ecosystem as feces and urine, and 16.96% was retained in herbivores for population regeneration or for human well‐being. Conclusions This study, as the first research on this topic, quantified the carbon flux of herbivores and found livestock accounts for a major part of consumed carbon on grasslands, which is important for understanding regional carbon budgets to mitigate and adapt to climate change over grasslands worldwide.

In a hybrid modular multilevel converter (MMC), capacitor voltage balance between the Full-Bridge Sub-Modules (FBSMs) and Half-Bridge Sub-Modules (HBSMs) is only possible when the arm currents are bipolar. For a grid-connected MMC, operating at unity power factor, this is typically only achievable when the modulation index is less than 2. Previous control methodologies, based on open-loop feed-forward compensating currents, have been proposed to operate an MMC with a higher modulation index. However, these solutions do not minimize the compensating currents; they cannot compensate entirely for both the variations in the operating conditions and the parameters typically encountered in a real implementation; and they do not consider the actual capacitor voltage imbalance between the FBSM and HBSMs. In this paper, a new nested closed-loop control algorithm based on an outer voltage control loop with an inner current loop is proposed and experimentally validated. Feed-forward currents are still utilised in the inner loop, but they are calculated using a new optimising algorithm which minimises the required compensating currents. Moreover, to the best of our knowledge, this is the first work where explicit algebraic equations to calculate these compensating currents are provided. Experimental results to validate the approach, obtained with an 18-cell hybrid MMC, are presented and discussed in the paper.

A distributed control strategy is proposed to share unbalanced currents in three-phase three-wire isolated AC Microgrids (MGs). It is based on a novel approach where, rather than analysing the MG as a three-phase system, it is analysed as three single-phase subsystems. The proposal uses a modified single-phase $Q-E$ droop scheme where two additional secondary control actions are introduced per phase. The first control action performs voltage regulation, while the second one achieves the sharing of negative sequence current components between the 3-legs power converters located in the MG. These secondary control actions are calculated online using a consensus-based distributed control scheme to share negative sequence current components, voltage regulation, and regulating the imbalance at the converters' output voltage to meet the IEEE power quality standards. The proposed methodology has the following advantages over other distributed control solutions, such as those based on the symmetrical components or those based on the Conservative Power Theory: (i) it achieves sharing of unbalanced currents, inducing smaller imbalances in the converters' output voltages than those of other methods, and (ii) the sharing of the unbalanced currents is simultaneously realised in both the sequence domain and the a-b-c domain. The latter is difficult to achieve using other solutions, as will be demonstrated in this work. Extensive experimental validation of the proposed distributed approach is provided using a laboratory-scale 3-wire MG.

Article 5 of the Stockholm Convention requires that each Party shall take measures to reduce the releases from anthropogenic sources of unintentional persistent organic pollutants (UPOPs), with the goal of their continuing minimization and, where feasible, their ultimate elimination. A major source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and other unintentional POPs releases, both in China and worldwide, is the metal industry in particular secondary metal industries such as copper smelting. More than 50% of the global secondary copper production is now in China and high levels of PCDD/Fs are released from these operations with the national inventory of China reporting a total of 1133.8 g toxic equivalents (TEQ) yr−1. Consequently the Global Environment Facility (GEF) is supporting the project ‘UPOPs Reduction through best available techniques and best environmental practices (BAT/BEP) in the secondary copper production sector’ in China compromising >50% of the global secondary copper production. As part of this project, information on relevant UPOPs from the metal industry have been reviewed and is presented here. This information should also be useful for other (developing) countries for controlling UPOPs releases from metal industries. This review and the information it contains provides a robust resource for policy makers, the industry and researchers to improve secondary copper production to BAT/BEP standards in relation to the reduction of PCDD/Fs and other UPOPs release. The contents include the details required to assist the understanding of the formation of chlorinated UPOPs along with their brominated and brominated-chlorinated analogues. It reviews the international sources of information on BAT/BEP, including the integrated approach considered in the European BAT Reference document, and shows how this can be used to achieve an overall reduction of pollutant releases from the industry. The current national standards of PCDD/F limits to air, water and solid residues have been compiled and are also included. Challenges which need to be addressed, such as the current international lack to consider brominated and mixed bromo-chloro PXDD/Fs which might be more environmentally significant than PCDD/Fs in some facilities – are also discussed.The study includes a brief description of the steps China has taken to change the national regulatory framework and to improve the sustainability of its secondary metal industry. The Stockholm Convention BAT/BEP guidelines recommend consideration of integrated pollution prevention and control and sustainable production as general principles which parties may incorporate when applying the BAT/BEP guidelines and guidance. This holistic approach is considered in the current project and in the improvement of the pilot facilities and will also be considered in the replication of experiences in other facilities. Using this approach ensures the implementation of the Stockholm Convention can contribute to integrated pollution prevention and control, the development of a circular economy and consequently to genuinely sustainable development thus contributing to different sustainable development goals (SDGs). It is hoped this approach will be adopted in other developing and transition economies and thus help to achieve improvements of the secondary metal industry globally.

In previous articles, the concept of series Z-source network has been extended to conventional indirect matrix converter to raise the voltage gain to unity and beyond. In this paper, this idea is modified and applied to a three-level indirect matrix converter. Two series Z-source networks are placed on the virtual dc-link between a rectifier and a neutral point clamped inverter on the positive and negative dc rails. Partial shoot-through states are used for voltage boosting. The series Z-source capacitor voltages and starting current stresses are reduced. A virtual space vector PWM method has been developed to ensure voltage boost ability of the converter. Simulation results from SABER are used to demonstrate the superiority of the proposed converter over the existing topology.

Electric Vehicles are becoming increasingly popular due to their environment friendly operation. As the demand for electric vehicles increases, it has become quite important to explore their charging strategies. Since charging and traction do not normally occur simultaneously and the power electronics converters for both operations have some similarities, the practice of integrating both charging and traction systems is becoming popular. These types of chargers are termed ‘Integrated Chargers’. The aim of this paper is to review the available literature on the integrated chargers and present a critical analysis of the pros and cons of different integrated charging architectures. Integrated chargers for electric vehicles with three-phase permanent magnet synchronous machines, multi-phase machines and switched reluctance machines were compared. The challenges with the published integrated chargers and the future aspect of the work were been discussed.

Abstract Background We believe junior doctors are in a unique position in relation to reporting of incidents and safety culture. They are still in training and are also ‘fresh eyes’ on the system providing valuable insights into what they perceive as safe and unsafe behaviour. The aim of this study was to co-design and implement an embedded learning intervention – a serious board game – to educate junior doctors about patient safety and the importance of reporting safety concerns, while at the same time shaping a culture of responsiveness from senior medical staff. Methods A serious game based on the PlayDecide framework was co-designed and implemented in two large urban acute teaching hospitals. To evaluate the educational value of the game voting on the position statements was recorded at the end of each game by a facilitator who also took notes after the game of key themes that emerged from the discussion. A sample of players were invited on a voluntary basis to take part in semi-structured interviews after playing the game using Flanagan’s Critical Incident Technique. A paper-based questionnaire on ‘Safety Concerns’ was developed and administered to assess pre-and post-playing the game reporting behaviour. Dissemination workshops were held with senior clinicians to promote more inclusive leadership behaviours and responsiveness to junior doctors raising of safety concerns from senior clinicians. Results The game proved to be a valuable patient safety educational tool and proved effective in encouraging deep discussion on patient safety. There was a significant change in the reporting behaviour of junior doctors in one of the hospitals following the intervention. Conclusion In healthcare, limited exposure to patient safety training and narrow understanding of safety compromise patients lives. The existing healthcare system needs to value the role that junior doctors and others could play in shaping a positive safety culture where reporting of all safety concerns is encouraged. Greater efforts need to be made at hospital level to develop a more pro-active safe and just culture that supports and encourages junior doctors and ultimately all doctors to understand and speak up about safety concerns.

A modified virtual space vector modulation approach for the control of a Z-source neutral point clamped inverter is presented in this paper. This approach works perfectly for the traditional neutral point clamped inverter. In this paper, the effectiveness of the virtual space vector modulation technique in balancing the input capacitor voltages of the Z-source NPC inverter with no low-frequency oscillations superimposed in addition to voltage buck-boost capability is demonstrated through simulations in SABER®. A prototype converter is used to capture experimental results for validation.