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Abstract An investigation of the flow inside the nozzle of a Cross-Flow turbine, which is a hydraulic turbine where the rectangular water jet issuing from the nozzle crosses the rotor blades twice, is presented here. Part of the investigation consisted in the experimental measurement of the static pressure distribution on the inside walls of two different nozzle configurations, both with the nozzle mounted alone and in the presence of a rotor. The tests performed in the presence of a rotor included the measurement of efficiency and covered a wide range of working conditions around the best efficiency point. The analysis of the results obtained in this way give us an indication of the influence of the turbine non-dimensional volume flow rate on the flow inside the nozzle and the way it affects the reaction degree of the machine and its efficiency level. Although most of the tests were carried out with a 25-blade rotor, one of the analysed nozzle configurations (that with an inside vane) was also tested with a 10-blade rotor, permitting the assessment of the effect the number of blades has on the flow in the nozzle. The flow inside the nozzle with no inside vane was numerically analysed using a method based on a Schwarz-Christoffel conformal transformation of variables. The numerical results show a fair agreement with the experimental data collected when the rotor was not present. A qualitative discussion of some of the losses occurring in the nozzle is advanced based on the computer results, and its conclusions are used for explaining the poor performance of the nozzle with no inside vane.

This paper determines the cost/revenue performance of a mobile communication system in an IMT-Advanced scenario with integrated Common Radio Resource Management (iCRRM). The iCRRM performs classic CRRM functionalities jointly with Spectrum Aggregation (SA), being able to switch users between non-contiguous frequency bands. The SA scheduling is obtained with an optimized General Multi-Band Scheduling (GMBS) algorithm with the aim of cell throughput maximization. In particular, we investigate the dependence of the throughput on the cell coverage distance for the allocation of users over the 2 and 5 GHz bands for a single operator scenario under a constant average Signal to Interference-plus-Noise Ratio (SINR), for the same type of Radio Access Technology and both frequency bands. The operator has the availability of a non-shared 2 GHz band and has access to part (or all) of a shared frequency band at 5 GHz. An almost constant gain near 30 % was obtained with the proposed optimal solution compared to a system where users are first allocated in one of the two bands and later not able to handover between the bands. It is shown that the profit in percentage terms decreases as the cell radius increases. These results allow for evaluating the impact of the revenue from the channel in the total revenue and in the profit, defined as the difference between revenues and costs, in percentage. Maximum profits of about 1270, 585 and 240 % have been obtained for prices of 0.10, 0.05 and 0.025 €/MByte, respectively, when iCRRM is employed, while profits of 990, 440, and 170 % have been reached with no iCRRM, i.e., simple CRRM. Finally, an energy efficiency strategy is proposed and analyzed, showing that there is significant transmission power saving potential through the opportunistic reallocation scheme.

Abstract This study employs the decomposition analysis of CO2 emissions for the period from 2000 to 2012. This technique computes five effects that drive changes in CO2 emissions in five subsectors of the Portuguese tourism industry. The energy over fixed capital, the capital over labour productivity, and the tourism intensity are the most important effects in accommodation, food and beverage services. The carbonisation index constitutes an important effect in transports. The capital over labour productivity intensity effect has the strongest influence, while the carbonisation index exerts a positive influence upon CO2 emissions in tour operators and travel agencies. The energy over gross fixed capital and tourism intensity effects predominate in cultural, sports and recreational services. The results of the econometric analysis further confirm the statistical significance of the aforementioned effects. Policy recommendations are provided.

Abstract The use of fossil fuel vehicles is one of the factors responsible for the degradation of air quality in urban areas. In order to reduce levels of air pollution in metropolitan areas, several countries have encouraged the use of electric vehicles in the cities. However, due to the high investment costs in this class of vehicles, it is expected that the spatial distribution of electric vehicles' adopters will be heterogeneous. The additional charging power required by electric vehicles' batteries can change operation and expansion planning of power distribution utilities. In addition, urban planning agencies should analyze the most suitable locations for the construction of electric vehicle recharging stations. Thus, in order to provide information for the planning of electric mobility services in the city, this paper presents a spatiotemporal model for estimating the rate of electric vehicles' adopters per subareas. Results are spatial databases that can be viewed in geographic information systems to observe regions with greater expectancy of residential electric vehicle adopters. These outcomes can help utilities to develop new services that ground on the rising availability of electric mobility in urban zones.

The harmony between environment and buildings is the strongest point of vernacular architecture. In this context, the Mediterranean vernacular architecture is harmonized with its local context, including culture and traditions. In addition, it respects environmental and climatic factors, construction materials and morphology. In the past, people in Palestine built their houses according to their possibilities, needs, available materials, topography, and culture. Without any control from the government or any legal limitations or architects, it was people architecture, simple architecture. This paper discusses the differences between vernacular and contemporary cities of Palestine at the urban scale. The research methodology adopts explanatory qualitative analysis and comparative synthesis methods for both the old and the new area of the city of Nablus and considers many parameters of the cities such as the city layout, skyline, infrastructure and public spaces. The outcomes of this research allow understanding how the new city is far away from the sustainability principles and how the old city is closer to it and how the architects and stakeholders could learn from the strategies of vernacular architecture. The paper draws a set of recommendations for more in-depth studies, based on quantitative survey with energy efficiency measurements in the Mediterranean climate.

This study proposes and evaluates a predictive control model for the management of the power flow in a hybrid microgeneration power plant with additional storage capacity. The plant integrates a photovoltaic array, a wind turbine, a diesel generator, and a lithium ion battery bank. One objective of the proposed predictive control model is to maximise the use of power from renewable resources looking for the weather predictions and thus minimise the use of fossil power from the diesel generator and corresponding CO2 emissions. Another aim is to maximise the duration of lithium ion batteries, since extending their lifetime is crucial for the system's economic viability, and since battery disposal brings environmental concerns as well. A numerical evaluation is performed about the evolution of power dispatch decisions and of the batteries state of charge, depending on the available power storage capacity. Model predictive control proves to be a suitable strategy in this system.

The combination of hydrothermal pretreatment followed by delignification with imidazole was evaluated for the first time as a potential selective two-stage fractionation for elephant grass, aiming at obtaining pure fractions susceptible to conversion to high value-added products. In addition, the recovery of cellulose and hemicelluloses and enzymatic hydrolysis yield of pretreated elephant grass were evaluated. Hydrothermal pretreatment at 180 °C under non-isothermal conditions allowed obtaining a liquor rich mainly in xylo- and glucooligosaccharides, as well as pentoses. Subsequent treatment of the recovered solid fraction with imidazole at 140 °C for 182.5 min resulted in 83.8 wt% delignification and cellulose enrichment of 97.7 wt%. The solids obtained from the two-stage pretreatment process also permitted high glucan to glucose conversion through enzymatic hydrolysis using Cellic CTec2 (99.0 mol%) or an enzymatic complex of Penicillium echinulatum (96.3 mol%).

The smart grid is a fully automatic delivery grid for electricity power with a two-way reliable flow of electricity and information among different equipment on the grid. Smart meters and sensors monitoring the system provide a huge amount of data in various part of smart grid. To logically manage this trouble, a new lossy data compression approach for big data compression is proposed. The optimal singular value decomposition (SVD) is applied to a matrix that achieves the optimal number of singular values to the sending process, and the other ones will be neglected. This goal is done due to the quality of retrieved data and the compression ratio. In the presented scheme, to implement the optimization framework, various intelligent optimization methods are used to determine the number of optimal values in the elimination stage. The efficiency and capabilities of the proposed method are examined using a wide range of data types, from electricity market data to image processing benchmarks. The comparisons show that the compression level obtained by the proposed method can dominate the points given by the existing SVD rank reduction methods. Also, as the other finding of this article, the performance of the rank reduction methods depends on the application and data types. It means that a rank reduction method can reveal a good performance in one application and performs unacceptably for another purpose. So, the optimized rank reduction can pave the way toward a robust and reliable performance.