Electromechanical Operation Research Articles

Ultrasound stimulated piezoelectric barium titanate and boron nitride nanotubes in nonconductive poly-ε-caprolactone nanofibrous scaffold for bone tissue engineering

Nanomaterials can provide unique solutions for the problems experienced in tissue engineering by improving a scaffold’s physico-bio-chemical properties. With its piezoelectric property, bone is an active tissue with easy adaptation and remodeling through complicated mechanisms of electromechanical operations. Although poly(ε-caprolactone) (PCL) is an excellent polymer for bone tissue engineering, it is lack of conductivity. In this study, piezoelectric barium titanates (BaTiO3) and boron nitride nanotubes (BNNTs) are used as ultrasound (US) stimulated piezoelectric components in PCL to mimic piezoelectric nature of bone tissue. Electric-responsive Human Osteoblast cells on the scaffolds were stimulated by applying low-frequency US during cell growth. Biocompatibility, cell adhesion, alkaline phosphatase activities and mineralization of osteoblast cells on piezo-composite scaffolds were investigated. BaTiO3 or BNNTs as reinforcement agents improved physical and mechanical properties of PCL scaffolds. In vitro studies show that the use of BaTiO3 or BNNTs as additives in non-conductive scaffolds significantly induces and increases the osteogenic activities even without US stimulation. Although BaTiO3 is one of the best piezoelectric materials, the improvement is more dramatic in the case of BNNTs with the increased mineralization, and excellent chemical and mechanical properties.

Application of big data technology in electromechanical operation and maintenance intelligent platform

Abstract Aiming at the data preprocessing requirements and label data cost issues arising from the intelligent operation and maintenance of electromechanical equipment, this article mainly studies structured data cleaning methods and fault prediction algorithms for a small number of label samples. First, this article introduces the overall architecture of the intelligent operation and maintenance system for electromechanical equipment. Second, based on the electromechanical equipment operation and maintenance data access service, data cleaning, and fault prediction, this article constructs an electromechanical equipment intelligent operation and maintenance platform based on Kafka message queue, Spark cluster, and other components, and introduces the functional composition of the system in detail. Finally, the article describes the functions of each component of data access service, data cleaning, and fault prediction in detail. To address the cost issue associated with sufficient labeled sample data for data analysis, we propose a semi-supervised learning algorithm, IF-GBDT, based on improved independent forests and Gradient Boosting Decision Tree. The independent forest algorithm supplements labels for unlabeled data based on the learning results of a small number of labeled samples. We also use the gradient lifting tree algorithm to train the model based on the new tag data set for fault prediction, thereby reducing the impact of lack of tags on the accuracy of the prediction model. Experiments show that this method improves classification accuracy and has good adaptability and concurrency performance for a small number of tags.

Application of modeling and analysis technology of mechatronics system in mechanical engineering

In the context of the rapid development of the global economy, different enterprises in the process of development, will be fully applied to various economic order, which improves the comprehensive competitiveness of enterprises. The innovative application of mechatronics system in mechanical engineering industry can promote the modernization and information development of mechanical engineering industry to a certain extent. In this process, we need to ensure the efficiency and reliability of mechanical design, so as to solve various problems existing in the design of the current mechanical system and electronic system. At present, in the development process of mechanical engineering, to fully apply the modeling and analysis technology of mechatronics system, it is necessary to understand the corresponding application principles, build the modeling and simulation application platform of mechatronics system, and carry out the joint simulation analysis of mechatronics products. Only in this way can we effectively solve various problems existing in the process of electromechanical operation of the model and ensure the design level of mechanical engineering.

Method of analysis and monitoring of the electromechanical converters parameters based on a linear integral criterion using sensitivity models

During the electromechanical converters operation in the composition of the working sets, objects parameters can change both under the influence of external factors, such as changes in the environmental characteristics, and due to parametric disturbances caused by changes of the physical characteristics of electromechanical converters elements. In this regard, the analysis and monitoring of electromechanical converters parameters is an important task. The article deals with a method that allows to ensure control over the operation of electromechanical converters during operation as part of working sets, based on variations analysis of the object parameters. The article provides a linear integral criterion computational scheme using the reference and sensitivity models to the parameters to be analyzed. The results provide a good way to estimate changes of the electromechanical converters parameters with the required accuracy.

Projection Welding of Nuts with Full Projections with Use of Electromechanical Operating Force System

Projection Welding of Nuts with Full Projections with Use of Electromechanical Operating Force System

Исследование влияния сейсмической активности на работу электромеханических систем

Исследование влияния сейсмической активности на работу электромеханических систем

RESULTS AND CHARACTERISTICS OF 5G HOLE DRILLING AND THE FIRST TAPPING OF LAKE VOSTOK

We present here a brief description of the drilling operations in the deep 5G hole at the Russian Vostok Station with more detailed account of the final stage of this long-term project successfully ended on February 5, 2012 with the first Lake Vostok unsealing. Relevant information on the borehole design and the technical characteristics of the downhole and surface drilling equipment is given. The peculiarities of the drilling process are discussed in connection with changing properties of the penetrated ice. The data analysis allows defining the main factors that influence the efficiency of the electromechanical drill system at great depths. It is shown that the elevated temperature of ice and its coarse-crystalline texture are mainly responsible for the significant for the showing-down of ice coring in the bottom sections of ice sheets observed at Vostok and at other drilling sites in Antarctica and Greenland as well. Based on the large amount of experimental data obtained in the course of the deep drilling at Vostok, we discuss the processes which occur in the borehole during the ice drilling and unsealing the sub-ice water bodies. In particular, we investigate the conditions for occurrence of hydraulic fracturing in the hole and the possible effect of the hydrofrac on the height of the water column that have risen in hole 5G after the Lake Vostok unsealing. Finally we formulate the drill equipment requirements and process specifications that would ensure the best performance of an electromechanical drill and trouble-free drilling operations at different depths in a borehole up to the bottom of ice sheet.

Improving the Sound Pressure Level of Two-Dimensional Audio Actuators by Coating Single-Walled Carbon Nanotubes on Piezoelectric Films.

As devices for amplifying or transforming electronic signals into audible signals through electromechanical operations, acoustic actuators in the form of loudspeakers are usually solid structures in three dimensional space. Recently there has been increasing demand for mobile electronic devices, such as mobile phones, to become smaller, thinner, and lighter. In contrast to a three dimensional audio system with magnets, we have invented a new type of flexible two dimensional device by utilizing the reverse piezoelectric effect in certain piezoelectric materials. Crystalline piezoelectric materials show electromechanical interaction between the mechanical state and the electrically-charged state. The piezoelectric effect is a reversible process in that materials exhibiting the direct piezoelectric effect (the internal generation of electrical charge resulting from an applied mechanical force) also exhibit the reverse piezoelectric effect (the internal generation of a mechanical strain resulting from an applied electrical field). We have adopted the plasma surface treatment in order to put coating materials on the surface of piezoelectric film. We compared two kinds of coating material, indium tin oxide and single-walled carbon nanotube, and found that single-walled carbon nanotube shows better performance. The results showed improvement of output power in a wider range of operating frequency; for the surface resistance of 0.5 kΩ/square, the single-walled CNT shows the range of operating frequency to be 0.75-17.5 kHz, but ITO shows 2.5-13.4 kHz. For the surface resistance of 1 kΩ/square, single-walled CNT shows the range of operating frequency to be 0.81-17 kHz, but ITO shows it cannot generate audible sound.

A New Approach : Software Development And Validation

For safety and effectiveness, the U.S. Food and Drug Administration (FDA) requires that software must be validated in the medical device industry. The software includes programs that are embedded in instruments and used in production/manufacturing process control, in which programmable logic controllers (PLCs) are widely used. The development and validation of a PLC program generally involves establishing software design (SD) structure, defining software requirements specification (SRS), conducting hazard analysis (HA), coding, and testing. The tasks are best accomplished through team efforts, with members taking the lead in activities suited to their skills within an organization; for example, SRS from the operation and the quality assurance (QA) departments; HA from emergency, health and safety (EHS); and coding from engineering. An integrated approach to these tasks would help a software project manager coordinate the team efforts effectively. This article describes an integrated approach to software development and validation in PLC programming. In this approach, the software development and validation start by establishing a normalized SD structure. This normalized structure is then incorporated into a traceability matrix (TM) of the SRS, into modules of program, and into test logs—such that every item defined in SRS or HA is registered in the normalized SRS TM table, coded in the normalized modules, tested, and documented in the normalized test logs. As the software system has a normalized structure, it becomes easy for different team members to define, review, code, test, document, and approve the relevant tasks within the software development and validation lifecycle.

Numerical Validation of Parametric Average-Value Modeling of Synchronous Machine–Rectifier Systems for Variable Frequency Operation

The derivation of accurate dynamic average-value models for synchronous machine-rectifier systems is challenging. A recently proposed parametric approach uses a computer-aided procedure for constructing the required averaged models, wherein the key nonlinear functions are extracted from a detailed (valve-by-valve) simulation. This letter shows that by using a judicious selection of parametric functions, a model obtained at a fixed generator speed is also valid for variable speeds. This is an important feature that makes this approach applicable to systems where electromechanical dynamics and variable speed operation is required.

Electro-Mechanical Coupling Performances of a Piezoelectric Bimorph

The influence of electro-mechanical operation conditions on the actuation capabilities of the piezoelectric bimorph is investigated in this paper. The objective is to compare the performance of the piezoelectric bimorph in different operation conditions and to determine the optimum operating conditions. An experimental set-up is built, and a series of experiments are presented to investigate the static and dynamic characteristics of the bimorph, including tip displacements of the bimorph under different preloads, dynamic response at different drive frequencies, step response and creep. Some properties such as displacement output, force output and hysteresis of the piezoelectric bimorph under different operating conditions are evaluated. Experimental results indicate strong dependence of both elastic and piezoelectric properties of the bimorph on the operating conditions.

Polymer MEMS processing for multi-user applications

We have developed a new polymer MEMS process that shows enormous flexibility in design parameters. This process uses entirely spin-on layers for structural and sacrificial materials. Further, this process flow is designed for multiple users to fabricate as many devices as possible on the same wafer which up to this point has not been demonstrated with polymer MEMS technologies. In this process, all structural layers are fabricated out of negative tone SU-8 photoresist and all sacrificial and separation layers are defined by a thin film of polystyrene. Using entirely spin-on layers for structural and sacrificial materials provides an easy way to select layer thicknesses without having to significantly alter the materials or processing techniques. A metal thin-film deposition step is also incorporated that allows electrical connection to the microstructures and actuators in this process. To characterize the robustness and flexibility of this technology we have fabricated a variety of in-plane and out-of-plane microstructures including chevron-type thermal actuators and tested their mechanical and electromechanical operation. The entire process sequence is accomplished at temperatures below 200 °C, making this technology compatible for post-processing integration of MEMS on an electronics circuit wafer.

An analysis of electroquasistatic induction micromotors

This paper studies the steady-state operation of the electroquasistatic induction micromotor (IM). A rotary pancake IM compatible with surface micromachining serves as an example. A model is developed to predict the electric potential, field and free charge within the IM. The model also predicts the motive torque and transverse force of electric origin acting on its rotor. The torque is balanced against bushing friction and windage to determine rotor velocity. Here, the bushing friction is modeled as a function of the transverse force acting on the rotor. Finally, an equivalent circuit model is developed, which described important aspects of the electromechanical operation of the IM. The model is used to study IM performance and its dependence on IM dimensions and material properties. For example, IM performance is predicted to be a complex function of axial IM dimensions and a strong function of rotor conductivity. The study also reveals that IM performance can differ significally from that of the variable-capacitance micromotor (VCM). For example, the dependence of motive torque and transverse force on axial dimensions can be significanly different in some IM operating regimes, allowing the possibility of improved performance over the VCM. IM and VCM dependences on micromotor geometry, velocity and material properties can also be significanlty different. The excitation and control requirements reflect the difference between a synchronous (VCM) and an asynchronous (IM) motor, as well as the possibility of obtaining an axially stable rotor position for certain IM material parameters.

An Electronic Control System for Operating a Cloud Chamber

To operate a cloud chamber—a visual detector to record trajectories of energetic charged particles—a sequence of electrical and electromechanical operations has to be performed at appropriate times...

PHYSICAL AND DOSIMETRIC ASPECTS OF DIAGNOSTIC GEOMETRICAL AND COMPUTER-ASSISTED TOMOGRAPHIC PROCEDURES

Tomographic systems offer potential for visualizing sections of the body that are ambiguously imaged by "flat" detection systems. Effective utilization involves the synergistic combining of various considerations, including appropriate motion, contrast, and extent of the anatomic region of interest; cost-benefit considerations; assurance of correct electromechanical operation; and benefit-risk analysis of patient exposure.

The Vertical Interval: A General-Purpose Transmission Path

Equipment is now available to utilize the vertical interval of the television signal to transmit digital information. A vertical interval (VI) encoder selects any line, 13 through 20, onto which is clocked the data originating from a character generator, computer or other digital device. At the receiving point, data are decoded for display in "real time" using a character generator, printed out in hard copy, or used to initiate electromechanical operations through proper interfaces.

Novel interpretation of synchro principles

This paper deals with a now interpretation of synchro principles. Approximate equations for currant and torque in a synchro may be established directly from synchronous machine theory. However, this analysis is built up from fundamental laws in order to establish a theory especially adapted to synchros. The investigation centres on obtaining the basic mathematical relations governing the electro-mechanical operation of a transmitter-receiver synchro pair. The aim ia to derive the synchronizing torque for the condition where the synchros remain at rest. In this condition implementation of the superposition principle can be made. The method used is to write a set of vector equations for the synchros with stator current represented by direct and quadrature axis quantities, using the applied rotor voltage as the axis of reference. Theso equations are used to determine the stator Current in terms of which the torque is expressed.