Ceramics, as a commonly used insulating and thermally conductive material, has a wide range of applications in the field of micro-nano manufacturing. In recent years, research on ceramic bonding has also increased. Ho...
Ceramics, as a commonly used insulating and thermally conductive material, has a wide range of applications in the field of micro-nano manufacturing. In recent years, research on ceramic bonding has also increased. However, ceramic bonding has some problems such as bonding failure and low bonding quality. Learning from other commonly used bonding materials, the important factor for the success of bonding is the surface properties of the material. Therefore, in this study, the surface of ceramic was treated by dielectric barrier discharge (DBD) to improve surface properties. The effects of dielectric barrier discharge on the surface properties of ceramic is investigated from the three aspects: hydrophilic angle, surface energy and surface morphology. In the dielectric barrier discharge experiment, blind via glass is used as the blocking medium for the upper electrode. The lower electrode is covered by ceramic, and the ceramic is also the material to be treated. The influence of processing time, discharge voltage and discharge frequency on the treatment effect is investigated in the experiment. The hydrophilic angle and surface energy of the treated ceramics are measured and calculated by contact angle measuring instrument, and the surface morphology was observed by scanning electron microscopy. The results show that the longer the discharge treatment time is, the larger the discharge output voltage is, the smaller the discharge gap is, the faster the hydrophilicity of the surface of the ceramic sheet is, and the higher the activation energy is. The damage of the ceramic surface after treatment is small, and the impurities on the surface are destroyed. In general, the surface properties of ceramics after dielectric barrier discharge treatment are better than before.
The development of dependable software for mechatronic systems can be a very complex and hard task. For facilitating the obtaining of dependable software for industrial controllers, some powerful software tools and an...
The development of dependable software for mechatronic systems can be a very complex and hard task. For facilitating the obtaining of dependable software for industrial controllers, some powerful software tools and analysis techniques can be used. Mainly, when using simulation and formal verification analysis techniques, it is necessary to develop plant models, in order to describe the plant behavior of those systems. However, developing a plant model implies that designer takes his (or her) decisions concerning granularity and level of abstraction of models; approach to consider for modeling (global or modular); and definition of strategies for simulation and formal verification tasks. This paper intends to highlight some aspects that can be considered for taking into account those decisions. For this purpose, it is presented a case study and there are illustrated and discussed very important aspects concerning above exposed issues.
This paper was initially intended to report on the outcome of the twice postponed demonstration mission of the ARCHES project. Due to the global COVID pandemic, it has been postponed from 2020, then 2021, to 2022. Nev...
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Composite materials have experienced great development in recent years, replacing traditional materials. Designed as metastructures, their properties recommend them in different fields, from sports materials to those ...
Composite materials have experienced great development in recent years, replacing traditional materials. Designed as metastructures, their properties recommend them in different fields, from sports materials to those in aeronautic and energy industries. In combinations of metallic layers or composites based on carbon/glass fibers, the properties of these materials allowed both the miniaturization of devices and the construction of large lightweight components. The paper aims to present the results of the tensile evaluation of the glass fiber reinforced plastics (GFRP), used in the construction of wind turbine blades. The blades are the most critical components of the wind turbines, being exposed to the damage and the defects that appear during operation can lead to the loss of the integrity of the blade structure. In order to increase the lifetime and to study the defects during operation, tensile tests were performed to determine the mechanical properties on a dry specimen, reinforced at [0 ° / 90 °], and the results obtained were compared with two specimens subjected to immersion in water for 14 and 21 days, two other specimens were immersed in seawater (Black Sea) for 14 and 21 days and one specimen was immersed in liquid nitrogen for 4 days.
We study one-dimensional optical wave turbulence described by the 1D Schrödinger–Helmholtz model for nonlinear light propagation in spatially nonlocal nonlinear optical media such as nematic liquid crystals. By ...
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The dual-drive H-gantry (DHG) is widely used for high-speed high-precision Cartesian motion control applications. Compared with the rigid-linked gantry design, the flexure-linked design is able to prevent the damage o...
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The dual-drive H-gantry (DHG) is widely used for high-speed high-precision Cartesian motion control applications. Compared with the rigid-linked gantry design, the flexure-linked design is able to prevent the damage of the cross-arm because a small degree of rotation angle is allowed. Nevertheless, the flexure-linked design possibly induces the resonance of the gantry because of the chattering of control signals. To maintain the precision tracking of two carriages and minimize the chattering of control efforts, we aim to seek the most suitable flexure joints among the available ones and optimize the decentralized feedback controller parameters under parametric uncertainties. The mechatronic design problem is formulated as an H_2 guaranteed cost control problem. All the stabilizing feedback controller gains are parameterized over a convex set, from here, numerical procedures are developed to obtain the global optimum by means of an outer-linearization-based optimization algorithm. Experiments are carried out and the results successfully validate the optimality and the robustness of the proposed design approach.
This paper presents an experiment on the affective reaction of a modified biomimical structure Chimpanzee Alive at a series of comands or vocal dialogues. The experimental structure includes and a biomimetic structure...
This paper presents an experiment on the affective reaction of a modified biomimical structure Chimpanzee Alive at a series of comands or vocal dialogues. The experimental structure includes and a biomimetic structures Scary Terry Talking Skull which has the possibility, through own development board, to send voice commands to the biomimetic structure Chimpanzee Alive. These voice commands are taken by using a the smartphone with android operating system and which has Arduino BlueControl applications installed. After processing of the voice commands by Arduino BlueControl, the smartphone send control signals by bluettooth, to biomimetic structures controller. This commands the motors of the biomimetic structure (for the movement of the eyebrows, mouth and eyelids), the result being the following expressive states: euphoric, pensiveness, annoyance. After obtain the expressive states, the Chimpanzee Alive structure returns into neutral state by activate a gestures sensor.
In the recent decade, robotic exploration is emerging as a vast research platform as it prolongs to be a challenging task, especially in unknown dynamic environments. Exploration plays a vital role in collecting data ...
In the recent decade, robotic exploration is emerging as a vast research platform as it prolongs to be a challenging task, especially in unknown dynamic environments. Exploration plays a vital role in collecting data from the areas inaccessible to the human. The operation of manual exploration systems in complex environments is cumbersome due to ineffective noise filtering, poor visibility and shuffling of map characteristics. In order to overcome such drawbacks, our approach focuses on the development of autonomous robotic exploration by designing a robust SLAM-based system, incorporating tri-layered mapping technique for automatic map generation and a new geometrical boundary-based path-planning technique to improve the mobility of the robot during navigation. The proposed path-planning algorithm yields better trajectory planning and obstacle avoidance using the pose, odometry and orientation parameters of the robot. The performance of the developed robot is evaluated through real-time experimentation, and it is evident from the results that, the proposed approach is preferable for autonomous exploration applications.
Analogies drawn to Maxwell's equations in tandem with complementary viscous flow theory, involving the introduction of a tensor potential, has been used to achieve exact integration of the Navier-Stokes equations....
Analogies drawn to Maxwell's equations in tandem with complementary viscous flow theory, involving the introduction of a tensor potential, has been used to achieve exact integration of the Navier-Stokes equations. The same methodology facilitates the derivation of an elegant four-dimensional Lorentz-invariant first-integral formulation of the energy-momentum equations for viscous flow assuming a flat space-time, consisting of a single tensor equation. It represents a generalisation of corresponding Galilei-invariant theory associated with the classical incompressible Navier-Stokes equations, with the key features that it: (i) takes the same form as its two- and three-dimensional incompressible counterparts; (ii) applies to any physical model, in that it does not depend at outset on the constitutive fluid relationship forming the energy-momentum tensor, other than that the latter is taken as being symmetric. The new general theory is applied to the problem of propagating acoustic waves, with and without viscous damping, and shown to recover the well-known classical expressions for sound speed and damping rate consistent with those available in the open literature.
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