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191.
192.
This work deals with establishing the tension load by impact dynamic testing of rubber composite conveyor belts. The value of tension load affects the shape of the used impactor and use of a support system as well as the weight of the ram and the impact height. An increase in the allowable stress when the belt is tensioned was examined during the test, to determine the effect of impact on the tension load. The obtained values of tension load are assessed using basic mathematical and statistical methods. Using the Design of Experiments method, factors that significantly affect the value of the tension load are identified. 相似文献
193.
María Liliana Ávalos-Rodríguez José Juan Alvarado-Flores Jorge Víctor Alcaraz-Vera José Guadalupe Rutiaga-Quiñones 《International Journal of Hydrogen Energy》2021,46(51):25909-25917
The objective of this work is to review the environmental and ecological policy instruments that Mexican legislation for existence of an Official Mexican Hydrogen Standard according to the premises motivates decarbonization. There is a worldwide interest in hydrogen (H2) and its incorporation into legal systems. In Mexico there are large legal gaps that question the legality of H2, because it is not recognized in a federal law and is only considered in technical standards of voluntary application. Also, Mexico has forest, agricultural, and livestock waste that, if properly used, can cover the energy demand of communities. The main findings of this study refer to the fact that, according to international standards for the management of H2 and taking into account the regulatory limitations in Mexico, it is possible to promote, an Official Mexican Standard exclusively aimed at establishing the minimum requirements for the design, construction, operation and maintenance of H2 storage, considering the areas of the opportunity offered by foreign experiences, according to the Mexican context. It is concluded that the parameters of legality exist in the instruments of environmental policy, to support the existence of an Official Mexican Standard of H2. 相似文献
194.
Parastoo Mohagheghi Wasif Gilani Alin Stefanescu Miguel A. Fernandez Bjørn Nordmoen Mathias Fritzsche 《Software and Systems Modeling》2013,12(3):619-639
There have been few experience reports from industry on how Model-Driven Engineering (MDE) is applied and what the benefits are. This paper summarizes the experiences of three large industrial participants in a European research project with the objective of developing techniques and tools for applying MDE on the development of large and complex software systems. The participants had varying degrees of previous experience with MDE. They found MDE to be particularly useful for providing abstractions of complex systems at multiple levels or from different viewpoints, for the development of domain-specific models that facilitate communication with non-technical experts, for the purposes of simulation and testing, and for the consumption of models for analysis, such as performance-related decision support and system design improvements. From the industrial perspective, a methodology is considered to be useful and cost-efficient if it is possible to reuse solutions in multiple projects or products. However, developing reusable solutions required extra effort and sometimes had a negative impact on the performance of tools. While the companies identified several benefits of MDE, merging different tools with one another in a seamless development environment required several transformations, which increased the required implementation effort and complexity. Additionally, user-friendliness of tools and the provision of features for managing models of complex systems were identified as crucial for a wider industrial adoption of MDE. 相似文献
195.
Structural design of carbon/epoxy bio‐inspired wind turbine blade using fluid/structure simulation 下载免费PDF全文
Mariana Correa‐Álvarez Valentina Villada‐Quiceno Julián Sierra‐Pérez Juan Guillermo García‐Navarro César Nieto‐Londoño 《国际能源研究杂志》2016,40(13):1832-1845
The purpose of this paper is to present the structural design procedure of a low‐speed, horizontal axis, bio‐inspired wind turbine blade made of carbon/epoxy. The methodology initiates with the mechanical characterization of the carbon fiber composite material. An aerodynamic simulation using Computational Fluid Dynamics (CFD) method is performed in order to obtain the pressure distribution profile of the blade. This result is coupled with a Finite Element Analysis (FEA) to carry out an iterative design process through a Fluid‐Structure Interaction (FSI) simulation. Different stacking sequences of laminates are evaluated to find a configuration which allows balance between aerodynamic and dynamic inertial loads, ensuring an almost undeformed geometry during wind turbine's operation. The final structural design of the blade consists in six regions with different laminates. These are balanced and symmetric with distinct thickness characteristics and stacking sequences, which vary in three different orientations: 0°, ± 45° and 90°, achieving a minimum deflection at the tip close to 3.11 cm, and a total weight of 3.6 kg of a 1.8 m radius blade, even with the restrictions imposed by the non‐conventional geometry. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
196.
Green tea is a rich source of catechins, which when purified have a high economic value as they can be used as a supplement in several products, to increase their health benefits. Catechins are regarded as desired components with several applications in a variety of areas such as foods, cosmetics and pharmaceuticals. A multicomponent sorption model has been developed for the separation of catechins from liquid tea streams, with macroporous resins in a packed bed column. Two commercially available food grade resins were considered: Amberlite XADHP and Diaion HP20. For the desorption step, two food grade solvents are used: water and ethanol. The adsorption and desorption behaviour is subsequently mathematically described with one-dimensional axial dispersed plug flow model that can accurately simulate the dynamics of the solvent swing sorption columns. The model parameters were regressed from experimental data. Five components are modelled in the competitive sorption: the main four catechins present in green tea and caffeine. The model was used for the process design and optimization for the recovery of catechins from green tea. 相似文献
197.
C. González-Nicieza M. I. Álvarez-Fernandez A. E. Alvarez-Vigil D. Arias-Prieto F. López-Gayarre F. L. Ramos-Lopez 《Bulletin of Engineering Geology and the Environment》2014,73(4):1211-1223
Vibrations generated by blasting carried out during the quarrying of material induce dynamic stresses that can give rise to damage of diverse considerations in surrounding buildings and structures. The adverse effects of vibrations caused by explosives used in mining and civil works can be controlled by suitably planning blasting operations, appropriately managing and optimising the equipment used, and monitoring the processes that cause these vibrations. The aims of the present study were to discuss and test the existence of a damping of underground vibrations, besides defining a transmission law for such vibrations which will depend on the directionality between the blast and the measurement point. Besides, the damages that vibrations can produce on the rock mass are evaluated. Their effects are very similar to those produced by an earthquake that disconnects the rock mass integral blocks. 相似文献
198.
It is shown that the injection of a squeezed vacuum into a correlated emission ring laser gyroscope enhances the sensitivity of the device. In particular, it is demonstrated that if the phase of the injected squeezed vacuum is chosen appropriately, then the output is squeezed in the phase quadrature. This may lead to complete suppression of the shot noise in the signal. 相似文献
199.
Miguel López-Portugués Jesús A. López-Fernández José Ranilla R. G. Ayestarán Fernando Las-Heras 《The Journal of supercomputing》2013,64(1):17-27
In this work, we carry out the parallelization of the single level Fast Multipole Method (FMM) for solving acoustic-scattering problems (using the Helmholtz equation) on distributed-memory GPGPU systems. With the aim of enlarging the scope of feasible simulations, the presented solution combines the techniques developed for our distributed-memory CPU solver with our shared-memory GPGPU solver. The performance of the developed solution is proved using two different GPGPU clusters: the first one consists of two workstations with NVIDIA GTX 480 GPUs linked by a Gigabit Ethernet network, and the second one comprises four nodes with NVIDIA Tesla M2090 GPUs linked by an Infiniband network. 相似文献
200.
Fernando Valdés Roberto Iglesias Felipe Espinosa Miguel A. Rodríguez 《Applied Intelligence》2012,37(2):267-279
This paper describes an innovative routing strategy for intelligent transportation units willing to perform merging manoeuvres with a moving convoy. In particular, we consider a transportation unit located inside a city (pursuer unit), and which wishes to join a convoy that is constantly moving around the city. We first describe a solution that considers idealistic conditions, i.e., the traveling time along each street is constant. We then go on to improve our first approach to deal with the realistic random nature of the traveling times experienced by the pursuer and by the convoy leader. Our search strategy applies Dynamic Programming to achieve a meeting point that is optimal in two ways: on one hand, the optimal destination is the one closest to the current pursuer??s position; on the other hand, the optimal meeting point must minimize the time that elapses until the pursuer meets the convoy (considering that the pursuer must always arrive first). Calculating the optimal path to every possible destination is highly inefficient, error prone and time consuming. On the contrary, we propose an efficient search strategy that will achieve the meeting point and the path to it, both optimally and in a very short time. This enables the real-time application of our approach either for finding new solutions or for re-planning old ones owing to unexpected real-conditions. 相似文献