Aerodynamic study of a blended wing body, comparison with a conventional transport airplane.

Blended-wing-body (BWB) aircraft are being studied with interest and effort to improve economic efficiency and to overcome operational and infrastructure related problems associated to the increasing size of conventional transport airplanes. The objective of the research reported here is to assess the aerodynamic feasibility and operational efficiency of a great size, blended wing body layout, a configuration which has many advantages. To this end, the conceptual aerodynamic design process of an 800 seat BWB has been done completed with a comparison of performance and operational issues with last generation of conventional very large aircraft. The results are greatly encouraging and predict about 20 percent increase in transport productivity efficiency, without the burden of new or aggravated safety or operational problems.

Water use efficiency and water productivity in the Spanish irrigation district ¿Río Adaja?

A study of the assessment of the irrigation water use has been carried out in the Spanish irrigation District “Río Adaja” that has analyzed the water use efficiency and the water productivity indicators for the main crops for three years: 2010-2011, 2011-2012 and 2012-2013. A soil water balance model was applied taking into ccount climatic data for the nearby weather station and soil properties. Crop water requirements were calculated by the FAO Penman- Monteith with the application of the dual crop coefficient and by considering the readily vailable soil water content (RAW) concept. Likewise, productivity was measured by the indexes: annual relative irrigation supply (ARIS), annual relative water supply (ARWS), relative rainfall supply (RRS), the water productivity (WP), the evapotranspiration water productivity (ETWP), and the irrigation water productivity (IWP. The results show that in most crops deficit irrigation was applied (ARIS<1) in the first two years however, the IWP improved. This was higher in 2010-2011 which corresponded to the highest effective precipitation Pe. In general, the IWP (€.m-3) varied amongcrops but crops such as: onion (4.14, 1.98 and 2.77 respectively for the three years), potato (2.79, 1.69 and 1.62 respectively for the three years), carrot (1.37, 1.70 and 1.80 respectively for the three years) and barley (1.21, 1.16 and 0.68 respectively for the three years) showed the higher values. Thus, it is highlighted the y could be included into the cropping pattern which would maximize the famer’s gross income in the irrigation district.

On loader productivity, rock strength and explosive energy in metal mining

Twenty production blasts in two open pit mines were monitored, in rocks with medium to very high strength. Three different blasting agents (ANFO, watergel and emulsion blend) were used, with powder factors ranging between 0.88 and 1.45 kg/m3. Excavators were front loaders and rope shovels. Mechanical properties of the rock, blasting characteristics and mucking rates were carefully measured. A model for the calculation of the productivity of excavators is developed thereof, in which the production rate results as a product of an ideal, maximum, productivity rate times an operating efficiency. The maximum rate is a function of the dipper capacity and the efficiency is a function of rock density, strength, and explosive energy concentration in the rock. The model is statistically significant and explains up to 92 % of the variance of the production rate measurements.

CSR Policies: Effects on Labour Productivity in Spanish Micro and Small Manufacturing Companies

This paper analyses empirical evidence of efforts to enable Spanish micro and small manufacturing companies to boost their labour productivity rates through the development of the main pillars of their corporate social responsibility (CSR) policies. This study aims to develop new approaches and sensibilities towards work from an ethical, values (virtues) and CSR perspective, showing how internal dimensions of CSR, such those related to relationships with employees and responsibility in processes and product quality, can improve labour performance and labour efficiency, thereby contributing to a better society. The results of a sample of 929 small businesses indicate that the social responsibility policies that most contributed to a short-term increase in labour productivity are those related to internal aspects of the company, in particular its involvement in the quality of processes and products, promotion of innovation and employee care. However, the impact on labour productivity of CSR policies related to external factors, such as relationship with stakeholders and environmental concern, could not be empirically proven in this paper.

Irrigation efficiency and water-policy implications for river-basin resilience

Rising demand for food, fiber, and biofuels drives expanding irrigation withdrawals from surface water and groundwater. Irrigation efficiency and water savings have become watchwords in response to climate-induced hydrological variability, increasing freshwater demand for other uses including ecosystem water needs, and low economic productivity of irrigation compared to most other uses. We identify three classes of unintended consequences, presented here as paradoxes. Ever-tighter cycling of water has been shown to increase resource use, an example of the efficiency paradox. In the absence of effective policy to constrain irrigated-area expansion using "saved water", efficiency can aggravate scarcity, deteriorate resource quality, and impair river basin resilience through loss of flexibility and redundancy. Water scarcity and salinity effects in the lower reaches of basins (symptomatic of the scale paradox) may partly be offset over the short-term through groundwater pumping or increasing surface water storage capacity. However, declining ecological flows and increasing salinity have important implications for riparian and estuarine ecosystems and for non-irrigation human uses of water including urban supply and energy generation, examples of the sectoral paradox. This paper briefly considers three regional contexts with broadly similar climatic and water-resource conditions – central Chile, southwestern US, and south-central Spain – where irrigation efficiency directly influences basin resilience. The comparison leads to more generic insights on water policy in relation to irrigation efficiency and emerging or overdue needs for environmental protection.