In recent years, paper-based microfluidic chips have emerged as a promising microfluidic platform due to their simplicity, low cost, portability, and ease of fabrication. They have been applied in various fields such ...
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A wireless communication method with dynamic adding nodes for Underground Search and Rescue robot is proposed: fix the address of the controller, add repeater nodes into the net dynamically, and shift the address of t...
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A wireless communication method with dynamic adding nodes for Underground Search and Rescue robot is proposed: fix the address of the controller, add repeater nodes into the net dynamically, and shift the address of the mobile terminal. With this method, the Search and Rescue robot can reach the deeper place of a mine to help rescue and keep in touch with the controller through wireless communication in a single channel, even in a complex laneway where radio wave cannot go through the thick wall. The collision in the process of the two-way multi-hop communication in the single channel will also be resolved by the communication direction priority and response signal mechanism, to enhance the reliability of communication. Finally, a sample is designed and an experiment is conducted to verify the efficiency of the method.
This paper describes a novel mobility assistive device under development in the Egypt-Japan University of Science and Technology (E-JUST). The proposed system can help patients who do not have enough physical strength...
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This paper describes a novel mobility assistive device under development in the Egypt-Japan University of Science and Technology (E-JUST). The proposed system can help patients who do not have enough physical strength on the lower limbs during sit to stand due to aging, diseases such as polymyositis and myopathy, and joint replacement surgery complications. It can follow the natural pattern of human motion during sit to stand providing assistance force under the shoulder. The overall device is compact and employees a parallel mechanism which provide more stiffness. Several experiments were carried out in a VICON room to calculate the human motion posture while sit to stand motion in addition estimate the trajectory of the end effector during assisting. Computer simulation was built to verify the performance of the proposed system with the reference trajectory.
Mohr-Coulomb theory is mostly used in civil engineering as it is suitable for soils, rock, concretes, etc., meaning that the theory is generally used for brittle facture of the materials, but there are cases when it m...
Mohr-Coulomb theory is mostly used in civil engineering as it is suitable for soils, rock, concretes, etc., meaning that the theory is generally used for brittle facture of the materials, but there are cases when it matches ductile behaviour also. The failure envelope described by the Mohr-Coulomb criterion is not completely accurate to the real yield envelope. The ductile or brittle behaviour of materials could not be incorporated in a linear envelope suggested by classic stress state theories and so, there have been a number of authors who have refined the notion of yield envelope so that it would fit better to the actual behaviour of materials. The need of a realistic yield envelope comes from the demand that the failure state should be able to be predicted in a fair manner and with as little errors as possible. Of course, certain criteria will be closer to the actual situation, but there is a constant need to unify and refine the limit stress theories in order to avoid problems as defining boundaries of application areas on numerical programs. Mohr-Coulomb's yield envelope is the most used one on programs, can be reduced to Tresca theory when the materials are conducting a ductile behaviour and has a linear simplified form. The paper presents some considerations with respect to the elliptical failure envelope correlated to the Mohr-Coulomb theory. The equations have been rewritten for triaxial situation to describe a more accurate state of stress that is encountered under real conditions in materials. Using the Mohr's circles to define the yield envelope, the calculus has been made in in order to determine the yield stress at tensile tests
Agent-technologies have been used for higher-level decision making in addition to carrying out lower-level automation and control functions in industrial systems. Recent research has identified a number of architectur...
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Agent-technologies have been used for higher-level decision making in addition to carrying out lower-level automation and control functions in industrial systems. Recent research has identified a number of architectural patterns for the use of agents in industrial automation systems but these practices vary in several ways, including how closely agents are coupled with physical systems and their control functions. Such practices may play a pivotal role in the Cyber-Physical System integration and interaction. Hence, there is a clear need for a common set of criteria for assessing available practices and identifying a bestfit practice for a given industrial use case. Unfortunately, no such common criteria exist currently. This work proposes an assessment criteria approach as well as a methodology to enable the use case based selection of a best practice for integrating agents and industrial systems. The software product quality model proposed by the ISO/IEC 25010 family of standards is used as starting point and is put in the industrial automation context. Subsequently, the proposed methodology is applied, and a survey of experts in the domain is carried out, in order to reveal some insights on the key characteristics of the subject matter.
Knowledge of material properties, in particular under hydrostatic pressure, is essential, both to select the proper material for a specific engineering application and to predict accurately its behaviour using mathema...
Knowledge of material properties, in particular under hydrostatic pressure, is essential, both to select the proper material for a specific engineering application and to predict accurately its behaviour using mathematical models. Many criteria were proposed to describe the behaviour of the various engineering materials under complex state of stress. Both materials and criteria can be sensitive or insensitive to hydrostatic pressure. This work demonstrates that modified Mohr-Coulomb criterion, with circular failure envelope, applied for ductile materials, is insensitive to hydrostatic pressure.
Trends and perspective directions in the field of pneumatic equipment and systems are first identified in the paper. Special attention is given to identifying the equipment and systems that can be adapted to the requi...
Trends and perspective directions in the field of pneumatic equipment and systems are first identified in the paper. Special attention is given to identifying the equipment and systems that can be adapted to the requirements imposed by a new industrial revolution - Industry 4.0. Pneumatics will continue to be an important domain and the paper presents arguments for that. The current stage of proportional pneumatics is presented and a comparison between analog and digital proportional pneumatics is made. In the final part of the paper an experimental model of a distributor controlled with modulated pulses is presented. The distributor is integrated in a system that controls the pressure in a reference volume.
Condensing gas boilers currently represent the most advanced solution for heating based on combustion of fossil fuels from both efficiency and pollution points of view. Besides, compared with the district heating, con...
Condensing gas boilers currently represent the most advanced solution for heating based on combustion of fossil fuels from both efficiency and pollution points of view. Besides, compared with the district heating, condensing gas boilers make possible the entire management of the heat supply function by the real heating needs. Subsequently, minimization of the heating cost is possible. In this view, one of the buildings of the 'Gheorghe Asachi' Technical University of Iasi was disconnected from the district heating and two condensing gas boilers – one of 25 kW and the other of 35 kW nominal output – were connected to the heating network to ensure the heat supply. A performance and economic analysis of the thermal installation with the two boilers, based on in situ experiments, was performed. The analysis was performed for nine operating regimes described by boilers flow water temperatures from 80 °C to 40 °C. Efficiency (in terms of higher heating value of the fuel) had varied from 86.7 % to 97.5 % and the price of thermal energy produced with the two boilers proved to be 21...30 % lower than the price of thermal energy coming from the district heating system. The annual heating savings are estimated to be 642...907 Euro/year, which induce a payback period of 1.6...2.3 years with strict reference to the investment represented by the two boilers.
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