820 research outputs found

    Optimisation of post-drawing treatments by means of neutron diffraction

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    The mechanical properties and the durability of cold-drawn eutectoid wires (especially in aggressive environments) are influenced by the residual stresses generated during the drawing process. Steelmakers have devised procedures (thermomechanical treatments after drawing) attempting to relieve them in order to improve wire performance. In thiswork neutron diffraction measurements have been used to ascertain the role of temperature and applied force – during post-drawing treatments – on the residual stresses of five rod batches with different treatments. The results show that conventional thermomechanical treatments are successful in relieving the residual stresses created by cold-drawing, although these procedures can be improved by changing the temperature or the stretching force. Knowledge of the residual stress profiles after these changes is a useful tool to improve the thermomechanical treatments instead of the empirical procedures used currently

    Development of a high-performance W-band duplexer for plasma diagnosis using a single band with dual circular polarization

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    Discrepancia entre la información que aparece en el artículo que indica que el copyright es de Elsevier, y la información que aparece en la página de la revista y en el Copyright Clearance Center que indican © 2019 The Authors. Published by Elsevier B.V., así como que el artículo está publicado en Open Access under a Creative Commons licenceThis work presents the design and experimental validation of a high performance, compact, waveguide duplexer operating from 91.5 to 96.5 GHz for its integration in diverse W-band microwave equipment as in plasma diagnosis applications. It uses a single frequency band, with two signals discriminated by different orthogonal circular polarization, which is generated by means of a septum orthomode transducer (OMT) polarizer. Moreover, this component is optimized loaded with the horn antenna for improving the overall system performance. It is explained how these two components are integrated into a very compact duplexer, designed using efficient numerical algorithms. The manufacturing process by mean of high precision milling, and including electrical discharge machining (EDM) has led to excellent performances. The measured return loss level and isolation are higher than 30 dB, and the insertion loss level is below 0.3 dB. Finally, the key parameter in this device, which reflects the symmetry in the manufacturing process, i.e., the axial ratio, is lower than 0.6 dB for both polarizations, an excellent result showing the potential of the presented designThis work was supported by the Spanish government under grants (ADDMATE) TEC2016-76070-C3-1/2-R (Agencia Estatal de Investigación, Spain, Fondo Europeo de Desarrollo Regional: AEI/FEDER/UE) and the program of Comunidad de Madrid, Spain S2013/ICE-3000 (SPADERADARCM

    Health-related quality of life, ethnicity and perceived discrimination among immigrants and natives in Spain

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    Statement: "This is an Accepted Manuscript of an article published by Taylor & Francis Group in [JOURNAL TITLE] on [date of publication], available online at:http://www.tandfonline.com/[Article DOI]."The current study compares subjective mental and physical health among native Spaniards and immigrant groups, and examines the effects of ethnicity and perceived discrimination (PD) on subjective health in immigrants. Design Two random samples of 1250 immigrants to Spain from Colombia, Bolivia, Romania, Morocco, and Sub-Saharan Africa and 500 native Spaniards, aged between 18 and 65, were recruited for this cross-sectional study. Several hierarchical regression analyses of ethnicity and PD on subjective mental and physical health (assessed using the health-related quality of life items, HRQLSF-12) were carried out separately for men and women. Results Male immigrants from Colombia and Sub-Saharan Africa showed better physical health than natives, controlling for age and socioeconomic and marital status. The immigrants - except for the Colombians - had poorer mental health than natives, especially African men and Bolivian women. Socioeconomic status had no impact on these differences. Among immigrants, PD was the best predictor of physical and mental health (controlling for socio-demographic variables). African men, Bolivian women and women without legal status exhibited the poorest self-rated mental health. Conclusion Clear differences in health status among natives and immigrants were recorded. The self-selection hypothesis was plausible for physical health of Colombians and Sub-Saharan African men. Acculturation stress could explain poorer mental health in immigrants compared with natives. The association between ethnicity and poor self-reported mental health appears to be partially mediated by discrimination

    Experimental investigation of the aerodynamic flow in the aircraft carrier ski-jump by means of PIV

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    Computational Fluid Dynamics (CFD) methods have opened a new field to perform aerodynamic studies saving money and time. The difficulties presented by this method to calculate complex flow field problems imply that CFD validation is needed to provide correct results. Experimental data have recently been used to validate the accuracy of CFD predictions. Particle Image Velocimetry (PIV) has shown to be a powerful tool in the investigation of complex flows. The aim of this paper is to present results from PIV experiments that would be interesting for CFD validation. Regarding aircraft operations, the short runway available implies the necessity of equipment which helps to take-off performances. Ski-jump ramp system improves aircraft performances by an increment of lift resulting in successful take-off operations. The ski-jump ramp presence generates a complex flow bounded by a turbulent shear layer and a low velocity recirculation bubble over the end of the flight deck. The adverse effects on the aircraft aerodynamics affect to pilot safe operations, so this region is an interesting problem to be studied by means of wind tunnel experimental tests

    Physiological Responses of Fagus sylvatica and Quercus robur Seedlings to Light Intensity

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    Conference poster presentationBroadleaf planting has become increasingly important in Ireland over the recent years and light is recognised as one of the main environmental factors affecting stand development, but to date there has been little research on broadleaf responses to light intensity, particularly in Ireland. Continuous cover forestry (CCF) is increasing as an alternative to clear-cutting and uses the control of light to produce plantation benefits. The physiological responses of beech (Fagus sylvatica) and oak (Quercus robur) seedlings to four different shade environments (100%, 62%, 51% and 28% of incident photosynthetically active radiation, PAR) were studied in a shadehouse experiment during the summer of 2013. Light-response curves (only measured in the extreme treatments) differed between beech seedlings of the Control treatment (PAR=100%) and those of the heavy shade treatment (PAR=28%) when PAR > 100 μmol m-2 s-1, while there was little difference for oak between both treatments. Light-response curves generally showed maximum photosynthetic rates (Amax) at 1500 μmol m-2 s-1 in both treatments, and this PAR value was used while measuring stomatal conductance (gs) and water use efficiency (WUE). Significantly higher values of Amax and gs were found in oak than in beech in the 62%, 51% and 28% treatments. There were no significant differences between oak and beech for Amax and gs in the Control treatment or for WUE in the four treatments.COFORD Forest Research Programm

    Design and Development of RC Railed Robot for Coffee Nursery Logistics

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    The Remote Controlled (RC) Railed Robot was designed and developed to transfer polybags from manual operation to an automated logistic system. Gizduino microcontroller was used to read and interpret commands sent and received by the transceivers to the robot and a remote to command instructions to the robot.The project was tested and evaluated at the Coffee Nursery of Cavite State University by determining the speed of the robot, the effectiveness of the remote control and the accuracy of the robot to lift a pallet and place it into an empty space.Results showed that the robot was able to receive and interpret commands provided by the remote control as well as perform the tasks successfully.The most significant recommendation was to use a counterweight at the rear side of the robot to avoid unnecessary derailments of the robot if lifting heavier or greater number of pallets is desired

    Techno-economic demand projections and scenarios for the Bolivian energy system

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    Increasing energy access in emerging economies has played an important role to maintain or achieve desirable social and economic development targets. As a consequence, the growing energy requirements need policy instruments to ensure energy supply for future generations. The literature reports many studies with different approaches to model and test policy measures in the energy sector, however few energy-related studies for Bolivia are available. This paper addresses this knowledge gap, representing the first national level energy demand model and projections for Bolivia. The model use demographic, economic, technology and policy trends with a pragmatic model structure that combines bottom-up and top-down modelling. The scenario analysis has a particular focus on alternatives for energy savings, energy mix diversification and air quality. Three scenarios were analysed: Energy Savings, Fuel Substitution and the aggregate effects in a Combined scenario. The reference scenario results show the overall energy consumption grows 134% in 2035 compared to 2012 with an annual average growth of 3.8%. The final energy demand in the energy savings scenario is 8.5% lower than the Reference scenario, 1.5% lower in the fuel substitution scenario and 9.4% lower in the combined Scenario. The aggregate impact of both energy savings and fuel substitution measures leads to potential avoided emissions of 25.84 million Tons of CO2 equivalent in the model horizon 2012-2035

    Towards a cloud‑based automated surveillance system using wireless technologies

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    Cloud Computing can bring multiple benefits for Smart Cities. It permits the easy creation of centralized knowledge bases, thus straightforwardly enabling that multiple embedded systems (such as sensor or control devices) can have a collaborative, shared intelligence. In addition to this, thanks to its vast computing power, complex tasks can be done over low-spec devices just by offloading computation to the cloud, with the additional advantage of saving energy. In this work, cloud’s capabilities are exploited to implement and test a cloud-based surveillance system. Using a shared, 3D symbolic world model, different devices have a complete knowledge of all the elements, people and intruders in a certain open area or inside a building. The implementation of a volumetric, 3D, object-oriented, cloud-based world model (including semantic information) is novel as far as we know. Very simple devices (orange Pi) can send RGBD streams (using kinect cameras) to the cloud, where all the processing is distributed and done thanks to its inherent scalability. A proof-of-concept experiment is done in this paper in a testing lab with multiple cameras connected to the cloud with 802.11ac wireless technology. Our results show that this kind of surveillance system is possible currently, and that trends indicate that it can be improved at a short term to produce high performance vigilance system using low-speed devices. In addition, this proof-of-concept claims that many interesting opportunities and challenges arise, for example, when mobile watch robots and fixed cameras would act as a team for carrying out complex collaborative surveillance strategies.Ministerio de Economía y Competitividad TEC2016-77785-PJunta de Andalucía P12-TIC-130

    La interpretación e integración de la norma tributaria

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    En el presente artículo, el autor se aboca a la tarea de explicar la interpretación e integración de la norma jurídica tributaria, refiriéndose a esta principalmente desde un punto de vista positivista, a partir del momento de su existencia; utilizando para ello criterios del Derecho General y considerando la importancia de estas herramientas para la correcta aplicación del Derecho. A lo largo del trabajo, el autor se va a concentrar en diversos temas de interés relacionados a la interpretación, empezando por lo más esencial como la definición, las características, el proceso, la integración, entre otros
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