Mariana R. Milici

The mathematical model of a stand measuring the torque of the termobimetal actuators

Evaluation the torque generated by the actuator systems is a problem in that the forces obtained have small values. The experimental stands used to evaluate the performance of an actuator must allow an easy adjustment of the measuring equipment to the characteristics of the tested system. The paper presents the mathematical model of a quadrilateral mechanism used in a stand designed to measure the torque of a thermo-bimetallic actuator. The accurate evaluation of geometry of the force transmission mechanism allows the improvement of measurement accuracy for low and very low values obtained in the first part of the use of the actuator.

Study about influence of power system operation and control of the piezoelectric actuators

Electronical power and control systems can decisively influence the performance of the piezoelectric engines and actuators. This paper presents the modeling of some ultrasonic motor and the role of some equipments that amplifies signals of variable frequency with the lower limit of 20 kHz and various wave forms, in order to obtain new performance in using the types of engines achieved in the Research Center EMAD from Stefan cel Mare University of Suceava and to identify new applications of the piezoelectric engines and actuators powered, controlled and monitored by the electronic systems achieved.

Simulation and PLC control of an electromechanical actuator with volatile liquid

The paper presents the study and operating control of an electromechanical actuator with volatile liquid (EAVL). The paper proposes a practical approach for EAVL displacement control using a PLC technology and a linear potentiometer transducer. Proposed electromechanical actuator has two essential features: low linear displacement and high strength. The electromechanical actuator is a technical dynamic system that can be investigated through transfer functions. In this regard, the step response of the EAVL was analyzed, the transfer functions (experimental and theoretical) and time constants values were identified for different quantities of volatile liquid used inside of actuator. Through transfer functions were analyzed parameters characterizing the dynamic properties of the system: delay, transient regime speed, response time and the coefficient of amplification. Also, the results of the evaluation through finite element method are analyzed. The EAVL behavior on the temperature and pressure variation is presented.

Elements of Modeling and Simulation for Piezoelectric Motors

In order to obtain a high rotational speed in comparison with the known embodiments, due to the increased amplitude of the contact point between the rotor and the active element, due to the possibility of adjusting the speed by changing the frequency of the two signals applied to the coupled discs, or due to the phase shift between the signals if the discs are supplied at the same frequency, it was achieved a stator by a non-removable coupling of two active elements. Modelling was performed in Comsol Multiphysics. In this respect we studied the variation of the strains and of the electrical potential, taking into account the changing of the parameters like the power voltage frequency, the power voltage amplitude, the distance between the support point and the edge of the discs system.

To use a microcontroller in a small energy powerplant management

Because of the increasing awareness that the energy market can help to prevent or combat global heating, its crucial to curb the energy consumption controlled. This paper discusses the development - step by step - of a home management system in order to decrease the energy intensity of a dwelling. The application is based on the model of a house with renewable sources: PV-panels, a solar collector and a windmill. The house is supposed to be self-providing in electricity because of its battery packet. Six temperatures and two voltages are measured and get processed in the microcontroller of a development board, via a self-made program written in MikroBasic PRO, in order to make a good energy policy. In total 17 actuators are controlled. The actual values are written to an SD-card every 15 minutes. Afterwards these values can be analysed on a PC (Excel) in order to improve the algorithm of the energy policy.

Using approximation functions in analysis of trehaloze intracellular concentration

The study object is to evaluate in which measure the supplementation of yeast inoculums with linoleic acid succeed to minimize the negative effect of the thermal shock stress factor on the one side, and the subduing to repetitive running of fermentation cycles, on the other side. The study proposes to find the most efficient way to grow the intracellular trehaloze content through beer yeast suspending into trehaloze solutions by different concentrations, at different thermo-stating temperatures and in different contact times, taking into account that this technique allows the passive transfer of exogenetic trehaloze inside the cells both at a new propagated cell population, and at cells resulted from an industrial inoculums.