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Bunch M.J.,York University | Bunch M.J.,A+ Network | Morrison K.E.,University of Guelph | Parkes M.W.,University of Northern British Columbia | Venema H.D.,International University for Sustainable Development
Ecology and Society | Year: 2011

In coupled social-ecological systems, the same driving forces can result in combined social and environmental health inequities, hazards, and impacts. Policies that decrease social inequities and improve social cohesion, however, also have the potential to improve health outcomes and to minimize and offset the drivers of ecosystem change. Actions that address both biophysical and social environments have the potential to create a "double dividend" that improves human health, while also promoting sustainable development. One promising approach to managing the complex, reciprocal interactions among ecosystems, society, and health is the integration of the ecohealth approach (which holds that human health and well-being are both dependent on ecosystems and are important outcomes of ecosystem management) with watershed-based water resources management. Using key management concepts such as resilience, such approaches can help reduce vulnerability to natural hazards, maintain ecological flows of water and the provision of other ecological services, and promote long-term sustainability of coupled human and natural systems. Priorities for understanding and realizing health benefits of watershed management include (i) addressing poverty and reducing inequities, (ii) promoting resilience (for health) in watersheds, and (iii) applying watersheds as a context for intersectoral management tools and policy integration. Examples of work linking health and watershed management demonstrate that not only is appreciation of complex systems important, but an effective approach is participatory and transdisciplinary and gives attention to equity and historical context. © 2011 by the author(s). Source


Filho H.M.D.O.,International University for Sustainable Development | Oliveira D.D.S.,Federal University of Ceara
2015 IEEE 13th Brazilian Power Electronics Conference and 1st Southern Power Electronics Conference, COBEP/SPEC 2016 | Year: 2015

This paper presents the dynamic analysis, simulation and experimental results on a ZVS (zero voltage switching) bidirectional isolated three-phase dc-dc converter. The topology uses a steady-state model based on fundamental components considering three possible control variables (dual phase-shift and duty cycle). The dynamic model of the converter using phase-shift (PS) control is developed employing the gyrator theory. Simulation results are presented to validate the plant model and test the digital control system. Implementation is performed in an FPGA (field-programmable gate array) device and closed-loop experimental results are discussed. © 2015 IEEE. Source


De Oliveira Filho H.M.,International University for Sustainable Development | Oliveira D.D.S.,Federal University of Ceara | Praca P.P.,Federal University of Ceara
IEEE Transactions on Power Electronics | Year: 2016

This study presents the steady-state analysis and experimental results on a soft-switching bidirectional isolated threephase dc-dc converter using DPS control with variable duty cycle. The topology uses three single H-bridges in the primary side and a three-phase inverter in the secondary side. High-frequency isolation is ensured by using three single-phase transformers connected in open delta-wye configuration. The variation of both phase-shift angles between the H-bridge legs and/or primary and secondary sides allows controlling the power flow, while reduced reactive power flow is possible. The variable duty cycle is used to ensure a constant voltage bus and/or zero voltage switching operation. A detailed analysis is presented considering amodel based on the fundamental components for the voltages and currents in the transformer. A comparison between the fundamental and the actual models is carried out to validate the proposed model. Experimental results on a 96 V/350-400 V, 3.5 kW prototype are presented and discussed to validate the proposed approach. © 2015 IEEE. Source


De Oliveira Filho H.M.,International University for Sustainable Development | De S. Oliveira D.,Federal University of Ceara | De Alencar E Silva C.E.,Federal University of Ceara
IEEE Transactions on Industry Applications | Year: 2014

This paper presents the analysis, design, simulation, and experimental results for a three-stage static power converter for battery charging feasible to small wind energy conversion systems. The system employs a boost converter cascaded with a Graetz bridge that allows the implementation of a maximum power point (MPP) tracker and the reduction of the mechanical speed under overvoltage conditions across the batteries. Moreover, a buck converter is connected in series with the boost stage to ensure a constant voltage bus between the aforementioned topologies. Thus, it is possible to extract the maximum power over the entire wind speed range, and battery charging can be realized through conventional techniques. The complete design of the proposed battery charger including power, control, and supervisory circuits is presented and developed, considering a 300-W system, with the possibility of charging battery banks rated at 12 or 24 V. Simulation results are presented to prove the existence of MPPs in the wind generator. Finally, experimental results of the developed prototype required to validate the functionality of the proposed study are presented and discussed. © 2014 IEEE. Source


Conliffe A.,International University for Sustainable Development
Global Environmental Politics | Year: 2011

This article examines the role of linkage politics in revitalizing the largely ineffective UN Convention to Combat Desertification (UNCCD). I argue that the UNCCD Secretariat has taken a leadership role in driving a regime linkage agenda that has focused disproportionately on linkages to the UN Framework Convention on Climate Change (UNFCCC). By comparing the UNCCD Secretariat's attempts to build desertification-mitigation and desertification-adaptation linkages, I propose three criteria for predicting whether regime linkages are likely to benefit source regimes (here the UNCCD): the linkage's contribution to source governance goals; the credibility of knowledge presented by the source regime; and the linkage's political feasibility for the target regime. This analysis shows secretariats to be important actors in linkage politics whose actions can lead to both beneficial and harmful outcomes for the regimes they are intended to serve. Finally, by asking whether desertification issues that overlap with climate change might be better addressed under the UNFCCC, I question when regime overlap indicates regime redundancy and warrants regime death. © 2011 by the Massachusetts Institute of Technology. Source

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