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Solar Energy Materials and Solar Cells, 116 + (2013) 176-181. doi:10.1016/j.solmat.2013.04.019

ON 16 NOVEMBER 2000, the final report of the World Commission on Dams (WCD) was launched in London, in the presence of South Africa’s former president Nelson Mandela. This represented a remarkable milestone in the history of dam policy and politics. During its two-year existence, WCD had conducted the most extensive review of research and evidence regarding the planning, impacts, and management of large dams. It had engaged with numerous stakeholders around the globe. It also made comprehensive recommendations about how to improve dam planning and management.

Distributed power generation and cogeneration of heat and power is an attractive way toward a more rational conversion of fossil and bio fuels. Solid oxide fuel cell (SOFC) – gas turbine (GT) hybrid systems are emerging as the most promising candidates enabling the achievement of a cleaner and more efficient conversion of a large variety of resources across a broad power range covering from small to medium scale applications. This thesis introduces an innovative concept of SOFC-GT hybrid system that allows reaching efficiencies higher than the state of the art while enabling the carbon dioxide separation and avoiding fuel cell pressurisation technical issues. Several hybrid system design alternatives based on this concept are analysed through a thermodynamic optimisation approach combining process modelling, advanced process integration techniques and multi-objective optimisation. A number of optimal hybrid system configurations are determined for different design targets. The results consistently demonstrate the higher energy conversion performance and flexibility enabled with respect to the state of the art. The innovative concept analysis is extended to two applications for which SOFC-GT hybrid cycles are expected to provide the most significant impact toward sustainability: the small scale distributed generation and the conversion of renewable resources. A simplified version of the new hybrid system layout is especially developed for small scale distributed generation, typical of residential building applications (5-10 kWel). Experimental data are used to prove the technical feasibility of the system and to assess the performance potentially achievable with currently feasible technologies. The results of the analysis underline that energy conversion efficiencies higher than traditional centralised power generation can be achieved even at such a small scale. A systematic process integration and optimisation approach is used to assess the energy conversion performance of the original SOFC-GT hybrid cycle fuelled with hydrothermally gasified wet waste biomass. The analysis highlights the considerable potential of the integrated system that allows for converting wet waste biomass into electricity with First Law efficiency higher than 60% while simultaneously enabling the separation of the biogenic carbon dioxide.

Using 40-year experiment data from a mono-modal rainfall area of northern Togo, we analyzed soil fertility dynamics when 2 and 3-year fallows were alternated with 3-year rotation of groundnut, cotton and sorghum. The control treatment consisted to continuous cultivate the soil in a rotation of groundnut/cotton/sorghum without fallow periods. For each rotation, two fertilisation rates were applied: no fertilisation and mineral fertiliser application during the cropping and/or the fallow periods. Yields of unfertilised crops, which averaged 1 t ha-1 during the first years of cultivation, were often nil in the long-term. In the long-term, yields of fertilised cotton and sorghum decreased by 32 and 50 %, respectively compared to the average of 2.4 and 1.6 t ha-1 obtained during the first decade of cultivation. The long-term decline in crop productivity was mitigated when fallow periods were alternated with cropping periods, and consequently there was partial compensation in terms of production for the unproductive fallowed plots. Long-term yields of fertilised cotton and sorghum in the periodically fallowed plots were 40 and 50 % higher than those in continuously cropped plots, respectively; they were 90 and 60 % higher than those in continuously cropped plots without fertilisation. Like for crop productivity, soil C, N and exchangeable Ca and Mg decreased less in periodically fallowed plots than in continuously cropped plots. The limited soil C decline when fallows were alternated with crops appears to be the consequence of no-tillage period rather than the effect of the highest C inputs to the soil.

Responses to recent climatic changes in the sediment of subarctic Lake Saanajärvi in northwestern Finnish Lapland are studied by comparison of various biological and sedimentological proxies with the 200-year long climate record, specifically reconstructed for the site using a data-set of European-wide meteorological data. The multi-proxy evidence of simultaneously changing diatom, Cladocera, and chrysophyte assemblages along with the increased rates of organic matter accumulation and pigment concentrations suggest that the lake has undergone a distinct typological change starting from the turn of the 20th century. This change, indicating an increase in lake productivity, parallels a pronounced rise in the meteorologically reconstructed mean annual and summer temperatures in the region between ca. 1850 and 1930's. We postulate that, during the Little Ice Age, the lake was not, or was only weakly, thermally stratified during summer, whereas the subsequent increase in air and hence epilimnetic water temperatures resulted in the development of the present summer stratification. The increased thermal stability of the lake created more suitable conditions for the growth of phyto- and zooplankton and changed the overall primary production from benthos to plankton. Mineral magnetic and carbonaceous particle records suggest long-distance pollution, particularly since the 1920's, yet the observed changes in lake biota and productivity can hardly be explained by this very minor background pollution; the 20th century species configurations are typical of neutral waters and do not indicate any response to pollution.

The most widely used process for hydrogen production is steam methane reforming. It can be carried out using a membrane reactor in which simultaneous hydrogen production and purification occur. Mathematical modeling of these reactors plays a key role in the selection of the design and operating parameters that yield high performance for the reactor. This review study discusses, synthesizes, and compares different mathematical modeling studies on the packed bed membrane reactors for hydrogen production from methane found in the literature. Different approaches used in these modeling studies for the hydrogen permeation steps, reaction kinetic expressions, phases involved (pseudo-homogeneous and heterogeneous), and spatial dimensions (one, two, and three dimensional) are given.

Intention of this work is to investigate the opportunity and feasibility of energy efficient networking in Home and Building automation protocols. Wired HBAS have traditionally devoted a relatively little attention to this point, especially if compared to wireless networks. This paper will try to address the issue by evaluating the introduction of power state switching in a real scenario and proposing the concept of functional and spatial adjacency among packets.

Abstract This work assesses the impacts of aggressive driving behavior on pollutants emissions and energy consumption at a city level. Furthermore, it performs an economic analysis considering the potential avoided emissions and fuel savings and discusses potential policy measures to address this topic. The results showed that aggressive driving significantly impacts energy consumption and emissions, with energy consumption increasing by more than ∼200% and emissions by 330% for aggressive driving compared to non-aggressive driving (in MJ/km and in g/km, respectively). This increment was found to be even higher for diesel vehicles than for gasoline vehicles. On the contrary, gasoline vehicles showed higher percentages of increase for most emissions (CO, NOx and NO). Results also revealed that aggressive driving impacts are higher for local streets when examining the city level. Moreover, the economic analysis showed that significant cost reductions may be achieved by avoiding aggressive driving, reaching up to 52.5 k€ on a daily basis. In conclusion, this study is of particular relevance to policy makers and urban planners, enabling to obtain a comprehensive overview of the impacts of aggressive driving behaviors at a city level and providing new insights to perform further developments and to assess the feasibility of the implementation of policy measures.