This study analyzed the numerical values of exothermic reaction of hydrogen storage in metal hydride5 alloy container. The internally controlled water cooling was used to accelerate the internal metal hydride reaction...
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This study analyzed the numerical values of exothermic reaction of hydrogen storage in metal hydride5 alloy container. The internally controlled water cooling was used to accelerate the internal metal hydride reaction rate. Moreover, the entropy increase principle of second law of thermodynamics was used to analyze the results of internal control parameters. The COMSOL Mutilphysics 4.3a numerical software was applied to simulate instantaneous entropy increase of finite element method for two-dimensional axisymmetric model. In addition, the total entropy increase of radius ir and flow rate U of internal control parameters was analyzed, so as to determine and find out the parameter value of minimum power consumption of internal control.
The outlook concerning the occurrence of industrial accidents has led to the implementation of response systems based on geoprocessing tools, which are widely adopted in emergency for such ventures, since they have he...
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The outlook concerning the occurrence of industrial accidents has led to the implementation of response systems based on geoprocessing tools, which are widely adopted in emergency for such ventures, since they have helped and served as a support for decision making, as well as for the preparation of guidelines aimed at managing emergencies. Nuclear power plants, because they constitute types of industrial activities that present dangerous conditions and attention regarding security are characterized as hazardous, especially due to consequences that occurred from large accidents— such as Chernobyl (1986) and Fukushima (2011)—highlighting the importance to its negative impacts, since the occurrence of accidents at nuclear power plants may affect surrounding areas, thus exposing a set of elements that are part of the environmental dynamics that integrates the catchment area where this type of plant is situated. In this way, through an integrated view of the region where the nuclear complex is located in Angra dos Reis City (Rio de Janeiro State) and, also, by aggregating information that portray the geobiophysical reality of its surroundings, several elements were incorporated into a database developed in a virtual environment, in which was produced a geographic information system (GIS) that presents a complex of variables that, once considered, can enhance various analysis in order to support emergency situations and planning, as well as guidelines that help define actions from the occurrence of accidental events at the nuclear plant.
A general transient mathematical model for managing microalgae derived hydrogen production, with temperature dependence of the cultivation medium is developed. For that, the simplified physical model combines principl...
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ISBN:
(纸本)9781467346290
A general transient mathematical model for managing microalgae derived hydrogen production, with temperature dependence of the cultivation medium is developed. For that, the simplified physical model combines principles of classical thermodynamics, mass, species and heat transfer, resulting in a system of differential equations which are discretized in space using a three-dimensional cell-centered finite volume scheme. A Michaelis-Menten type expression is proposed for modeling the rate of H_2 production with dependence on O_2 inhibition. Tridimensional simulations are performed in order to determine the mass fractions distributions inside a compact photobioreactor (PBR), under different operating conditions. A relatively coarse mesh was used (6048 volume elements) to obtain converged results for a large compact PBR computational domain (5m×2m×8m). The largest computational time required for obtaining results was 560 s, i.e., less than 10 min. The numerical results for microalgal growth are validated by direct comparison to experimental measurements. Hydrogen production simulations are conducted to demonstrate PBR intermittent operation (aerobic and anaerobic stages) feasibility and adequate species evolution trends in an indirect biophotolysis approach. Therefore, after experimental validation for a particular H_2 production system, it is reasonable to state that the model could be used as an efficient tool for PBR systems thermal design, control and optimization for maximum H_2 production.
This paper shows the hardware implementation of a sensor fusion technique applied to both an ultrasonic and an infrared sensors, for estimating the distance, using an FPGA. Sensor fusion is a natural application of st...
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This paper shows the hardware implementation of a sensor fusion technique applied to both an ultrasonic and an infrared sensors, for estimating the distance, using an FPGA. Sensor fusion is a natural application of stochastic filtering area (such as Kalman filters), being applied extensively in different areas such as mobile robotics, signal processing, bioengineering, among others. This technique permits to combine the information provided by the sensors, improving the estimate of the measured variable, as well as its uncertainity. The sensors have previously been characterized using the same acquisition system that was used for the sensor fusion, and the fitting curves have been calculated for them. Finally, synthesis and simulation results demonstrate that the architecture implemented in the FPGA is suitable for calculating the estimate and uncertainity of the overall fusion process.
Many professional or daily activities require load displacement by human arms or human powered vehicles. Those activities may lead to muscle-skeleton diseases in load-carrying professionals as in people carrying their...
Many professional or daily activities require load displacement by human arms or human powered vehicles. Those activities may lead to muscle-skeleton diseases in load-carrying professionals as in people carrying their personal belongs. To help prevent those injuries, the scientific community has developed human-robot cooperation systems which are implemented through a robot that works as a force multiplier equipment and the human that works as the positioning or force setpoint generator. In order to provide the force multiplication feature and also to care about the human perception during the cooperative task, this paper presents the design and implementation of a robot that is dedicated to help in translational displacements while emulating an active mechanical impedance that provides a friendly perception to humans.
In an outpatient clinic, in which multiple classes of patients are given appointments, capacity management and scheduling decisions are particularly important. Once an appointment is scheduled;it is not uncommon for t...
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ISBN:
(纸本)9780983762423
In an outpatient clinic, in which multiple classes of patients are given appointments, capacity management and scheduling decisions are particularly important. Once an appointment is scheduled;it is not uncommon for the appointment to be rescheduled or cancelled prior to the appointment day, or a patient may simply not show-up on his/her appointment day. Thus it is crucial to consider all of these patient behaviors when assigning an appointment. In this study we consider multiple classes of patients with different demand rates, service times, and different delay-dependent reschedule, cancellation, and no-show rates. We develop a simulation model to analyze the effects of reducing the appointment planning horizon. In our experimental analysis we also evaluate different calendar structures: traditional slots, standardized 20 or 30 minute slots, and slotless designs. We use capacity utilization and "seen" patient proportions as the performance indicators in our model. Our results indicate that we can significantly increase physician utilizations and the percentage of seen patients by reducing the appointment planning horizon. We also observe improvements in the performance indicators if we use a slotless design or standardized appointments with shorter slot lengths.
In robotic surgery, a surgeon checks only a surgical site of patient in the progress of surgery by vision and sound information. In order to solve this limited information, the haptic function is necessary. For haptic...
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ISBN:
(纸本)9781479914951
In robotic surgery, a surgeon checks only a surgical site of patient in the progress of surgery by vision and sound information. In order to solve this limited information, the haptic function is necessary. For haptic realization, it requires much more information through various sensors. However, because of the special environment inside human body, it is not easy to apply sensors such as a force sensor. The low inertia master device for laparoscope operation with cable-conduit was developed in previous research to give haptic function. This suggested a possibility of developing a master device by using the cable-conduit. However, since each axis of rotations does not match with human wrist joint, it is very inconvenient to use. This paper suggests a new mechanism design structure to solve these problems of previous work by new form of master device. And it is experimented and analyzed that a cable conduit connected control box can follow well according to a trajectory of one axis's angle.
In this paper we address a minimum latency problem and propose a multi-start strategy for solving it. For constructing initial solutions two procedures are designed, which are based on metaheuristic GRASP. We also dev...
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Obstacle detection while driving to prevent a car accident is always an important issue. The optical flow method is employed to detect the obstacles in around view monitor (AVM). However, by using optical flow only, t...
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Obstacle detection while driving to prevent a car accident is always an important issue. The optical flow method is employed to detect the obstacles in around view monitor (AVM). However, by using optical flow only, this method sometimes detects error optical flow points. Also, there is no enough feature points to be detected in order to find the region of obstacles. This paper proposes not only combines disparity map and optical flow of the bird's-eye view images in AVM, but also warn drivers that the region of obstacles nearby. We can find the relative heights of each obstacle's feature point by optical flow and use stereo disparity to find the obstacle and its height in the meantime. Furthermore, in the study, using CUDA parallel computation to speed up calculation. Based on the combination of optical flow and stereo disparity information, we can get the region of the obstacles more accurate.
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