13,892 research outputs found
Impact of introducing ecoinnovation measures on productivity in transport sector companies
The transport and storage sector, like other sectors of the Spanish
economy, is experiencing the effects of the current economic crisis.
The Annual Services Survey prepared by the Spanish National Institute
of Statistics (INE) shows that between 2008 and 2013 there was an
11.9% reduction in turnover and an 18.3% reduction in paid workers
in companies in sector. However, in the same period, there was a 7.8%
increase in labour productivity.
The main aim of this study was to determine the impact of factors
related to innovation and the environment, among others, on labour
productivity in the Spanish transport and storage sector. Few studies
are available on this topic, which is most likely due to the scant
statistical information available for the sector analysed. The structural
analysis model used in this study was an extended version of the wellknown
Cobb‐Douglas production function applied to data obtained
from the Technological Innovation Panel (PITEC). PITEC is a panel type
database (for 2003‐2013), which was developed jointly by the Spanish
National Institute of Statistics (INE) and the Spanish Foundation for
Science and Technology.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Inclusive Development in Latin America and Smallholders’ Interactive Learning Spaces
Inclusive development appears as a challenge in Latin America countries after the rupture of the social inclusion as a trickle-down effect of the economic growth. Searching development with inclusion several public policies were implemented in Latin American focusing in the agri-food production. In order to assess the progress to reach such objectives, two cases are studied. Smallholder milk producers at the Loma Blanca community (Mexico) and smallholders olive producers at Aimogasta (Argentina) were considered. Interactive learning spaces were clearly identified as consequence of the linking between product, producers and territory. Despite these results, several queries are still opened.Fil: Bastida Mercado, Claudia. Universidad Autónoma del Estado de México; MéxicoFil: García Martínez, Anastacio. Universidad Autónoma del Estado de México; MéxicoFil: Sanchez, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro de Estudios Urbanos y Regionales; Argentina. Universidad de Morón; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentin
Interaction flow bathymetry at tidal scale in the main sill of the Strait of Gibraltar
Data collected in the north and south channels of the main sill of the Strait of
Gibraltar (Camarinal sill) are used to investigate processes connected to the internal
hydraulics of the exchange through the Strait at tidal frequencies. Observations strongly
suggest the setting up of hydraulic jumps at both the western and eastern flank of the sill,
the latter associated with the reversal of the Mediterranean undercurrent during spring
tides. The northern site is more sensitive to processes triggered by the formation and
release of the jump formed east of the sill during intense enough ebb tide cycles, which is
thus better traced at this location; the southern site detects more neatly the fluctuations and
footprints associated with the hydraulic jump regularly formed to the west of the sill
during flood tides. A detailed inspection of the high resolution bathymetry of the area
reveals the existence of two enclosed depressions at either side of the sill, almost certainly
carved by the bottom flow over the millennia, whose shape and morphology are suggestive
of this spatial differentiation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Influence of Embankments with Parapets on the Cross-Wind Turbulence Intensity at the Contact Wire of Railway Overheads
Winds as an environmental factor can cause significant difficulties for the railway system operation. The railway overhead has been particularly vulnerable to cross-winds related problems, such as development of undamped oscillations due to galloping phenomenon. The installation of windbreaks to decrease the aerodynamic loads on the train can affect the loads on railway overheads triggering cable galloping. One essential parameter to indicate the influence of the parapet wake on the catenary contact wire is the turbulence intensity. In this paper the results of an experimental analysis of the turbulence intensity due to the presence of parapets carried out in a wind tunnel are reported. Embankments equipped with different parapets have been tested and turbulence intensity has been measured at both contact wire locations, windward and leeward. The relative influence of the parapets is measured through a reduced turbulence intensity, defined as the ratio between the turbulence intensity measured with parapet and the turbulence intensity in the case without any parapet on the embankment. In general the reduced turbulence intensity increases as the height of the parapet increases
Labour flexibility and productivity in the hotel sector
In this paper, we analyze the effect of labour flexibility on productivity in the Andalusian hotel industry using raw data of our own database and applying an expanded version of the standard production function by distinguishing between part-time, temporary, and full-time labour inputs. Our results show that productivity is lower the higher the percentage of temporary and part-time workers and there are no differences between the impacts on productivity of both types of labour contract. Future studies should analyze the differential impact of all the types of contracts discussed on the mean cost per employee in this sector.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Study on the viability of transfer trajectories to the stability region around L4 and L5 Lagrange Points in the Earth-Sun system
In the present thesis a study is done regarding the viability and optimization of trajectories to get to the stability region around Lagrange points L4 and L5 from the Earth, specifically from periodic orbits around Lagrange points L1 and L2, in the frame of the circular restricted three-body problem of the Earth-Sun system. The trajectory of a spacecraft inside this stability region around L4 and L5 does not leave it for 1000 years or more and without the necessity of any maneuver, i.e. without fuel consumption. Furthermore, this region offers good positions to observe the Sun, and with that to be able to understand and predict the behaviour of possible space weather events, such as solar flares or coronal mass ejections. This is the set of reasons why this stability region is of scientific interest, so that the objective of the present thesis is to study how to get there in the most optimal way possible. Therefore, the unstable invariant manifolds that arise from the periodic orbits around L1 and L2 are the paths to consider as starting points for the transfer trajectories up to L4 and L5, as they take advantage of the dynamic nature of the circular restricted three-body problem. Once the stability region, the types of trajectories around L4 and L5 and the unstable invariant manifolds have been defined, it has been found that it is possible to reach L4 and L5 with a delta-V budget to perform the impulsive maneuvers of around 260 m/s, with times of flight between 8.5 and 9 years. However, it is possible to decrease the time of flight if the delta-V budget is increased, achieving 6-year transfers with delta-V budgets of around 400 m/s or 4-year transfers with delta-V budgets of around 550 m/s. These results show that there is a large variety of trajectories to choose to get to the equilibrium points L4 and L5, all them comparable, in flight times as well as in delta-V budget, to both current and past interplanetary missions. Therefore, it has been seen that there are lots of reasonable possibilities to send a satellite or a set of missions to these stability regions, in order to carry out observations of the Sun and research about space weather without needing to perform station-keeping maneuvers such as in L1 and L2 during the mission period
Environmental attitudes of European tourists: A multilevel analysis
Literature shows that heterogeneity in willingness to pay for traveling is explained by regional clusters because not all the tourists are equally sensitive to income and price adjustments. This paper demonstrated that such heterogeneity in tourist behavior is also shown in environmental considerations when they are making decisions about their holiday plans. Popular support for environmental protection among tourists from EU-27 countries were investigated. The findings are congruent with the hypothesis that environment support depends not only on individual characteristics of themselves but also of certain contextual variables related to their place of residence.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Explaining tourists´ support for environmental protection
Any movement towards sustainable tourism is dependent not only upon the industry and other key stakeholders but also the demand side, namely the tourists. Yet, there is a limited literature from the demand point of view. In this area, contributions to an understanding of tourists’ support to sustainable development are necessary. This paper analyzes the main determinants in tourist behavior regarding the environmental considerations when they are making decisions about their holiday plans. General literature on this issue highlights the need to consider socio-economic variables of the individual as well as the attributes related of their style of living. If the econometric model takes into account all these variables simultaneously, then the linkage between contextual changes and tourists´ behaviour is enriched and it may be estimated more accurately. In this sense, a multilevel approach using a random-intercept logistic models is proposed, since tourists belong to a country are affected by the same contextual variables.
The analysis comprises a joint dataset composed by microdata belong to the survey Attitudes of Europeans Towards Tourism, which corresponds to Flash Eurobarometer 281, macrodata from Eurostat (GDP in pps and GDP growth) and additional variables profiles from the 2005 Environmental Sustainability Index. Country-specific effects are calculated across the EU-27 countries, which corroborated that attitudes to the sustainable tourism are heterogeneous geo-graphically. The higher the level of GDP, the lower the level of tourists´ support. These results could be explained because tourists of richer countries already have to pay more tax for envi-ronmental protection. Age, gender and educational attainment are relevant. Motivations for travelling, size of the community, type of the destination, and environmental sustainability indi-cators of the place of residence are also important factors.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Lagrangian particle tracking for the assessment of the flushing efficiency of harbor structures: the case of the Port of the Bay of Algeciras, Strait of Gibraltar
The Bay of Algeciras, an inlet of about 9 x 11 km located at the eastern margin of the Strait of Gibraltar, opens to the south, where the Atlantic jet leaves the Strait and starts spreading into the Alboran Sea. In its western side, the Bay hosts one of the main ports in Europe, neuralgic base of the major traffic load from Europe to Africa and from Europa to the rest of the oversea countries. The massive transport of liquid and solid bulk or bunkering activity, daily carried out in the Bay, combined with the harsh weather conditions that often lash the zone, give the ideal scenario for an incipient ecological disaster. This high environmental risk motivates the interest for a deeper understanding of the small scale dynamics of the Bay and the role played by the port structures in case of oil spill or other surface contaminations. A series of Lagrangian particles tracking (LPT) experiments were carried out to investigate the flushing patterns of the Bay and 8 different docks inside the local port, under a representative variety of external conditions, such as tide phase and strength, and winds. A 2D LPT algorithm has been adapted to fully exploit the outputs of a very high resolution (∼30m) three-domain-nested hydrodynamic model, with the aim of resolving the complex circulation within the structures of the harbor. Winds are a clearly dominant factor, with westerlies featuring e-folding times one order of magnitude lower than easterlies. Fortnightly tidal modulation presents a counter-intuitive effect, with spring tides that, despite promoting higher ventilation in a first instance, end up providing higher accumulation of particles inside the docks and higher e-folding times than neap tides. Tide phase affects the current direction at the entrance of the docks during the first few hours of simulation and its effect is progressively masked throughout the experiment. In the 45% of the experiments, a significant quantity of particles flow out to the Alboran Sea (55% in the whole Bay experiment), confirming the importance of the Bay on the exportation of pollutant/properties to the nearby basin.Universidad de Málaga. Campus de Excelencia Internacional del Mar, CEIMAR. Campus de Excelencia Internacional Andalucía Tec
Effect of key design parameters on bacteria community and effluent pollutant concentrations in constructed wetlands using mathematical models
Constructed wetlands are currently recognized as an effective environmental biotechnology for wastewater treatment, but the influence of their design parameters on internal functioning and contaminant removal efficiency is still under discussion. In this work, the effect of aspect ratio and water depth on bacteria communities as well as treatment efficiency of horizontal subsurface flow constructed wetlands (HSSF) under the Mediterranean climate was evaluated, using a mathematical model. For this purpose, experimental results from four pilot-scale wetlands of equal surface area but different aspect ratios and water depth were used. The HSSF system was fed with municipal wastewater. The experimental data were simulated using the BIO_PORE model, developed in the COMSOL Multiphysics™ platform. Simulations with the BIO_PORE model fitted well to the experimental results, showing a higher removal efficiency for the shallower HSSF for COD (93.7% removal efficiency) and ammonia nitrogen (73.8%). The aspect ratio had a weak relationship with the bacteria distribution and the removal efficiency. In contrast, the water depth was a factor. The results of the present study confirm a previous hypothesis in which depth has an important impact on the biochemical reactions causing contaminants transformation and degradation.Peer ReviewedPostprint (author's final draft
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