Browse

You are looking at 1 - 10 of 281 items for :

  • Bioengineering and Biomedical Engineering x
Clear All
Open access

M.G. Ionita and H.G. Coanda

Abstract

The microscopy images can be affected by periodic noise, resulting in quality degradation and the appearance of repetitive patterns on the micrograph. In order to effectively remove the periodic noise, a new adaptive method is proposed in this paper. The presented approach analyzes the frequency domain of the first order Haar Wavelet transform, determines the frequency regions that correspond to noise and corrects the magnitude spectrum components of the undecomposed DFT transform of the image. Experimental results are provided.

Open access

Emil Cazacu, Valentin Ioniţă and Lucian Petrescu

Abstract

: Low-voltage asynchronous motor is the most common load used in any industrial electric facility. Due to their robustness and reliability, the induction motors have a very large application spectrum and are to be found in a variety of power units. It is assumed that over 70% of total energy used in any electric utility is dedicated to the electric motor drive systems. The paper quantitatively studies the transient state of such motors, which occurs at their start-up. The waveforms characteristics of these inrush currents are predetermined mainly by solving the associated differential equations that describe the dynamic phenomena at their start-up. An experimental investigation on an induction motor of 4 kW is also carried out. Supplementary, different solutions for the energising of these low-voltage motors are presented highlighting their performances and limits. These methods are critically rated according to their mitigation ability of the power quality issues associated with the energizing process.

Open access

Prapawan Thongsri

Abstract

Calcium manganese oxide (CaMnO3) polycrystalline was synthesized by solid state reaction (SSR) and hot-press (HP) methods. The powder of CaCO3 and MnO2 were mixed by ball milling then calcined at 850°C for 10 h and hotpressing at 850 °C for 1 h to obtain the CaMnO3 samples. The crystallography of the samples was analyzed by the X-ray diffraction (XRD). The microstructures of the samples were observed by scanning electron microscope (SEM). It was found that, the sintering process influence the crystalline perfection and have a direct impact on the mechanical properties of CaMnO3 and their aging behavior. The values of the effective elastic modulus was 6 GPa and Flexural strength was 0.417 MPa of CaMnO3 were found to be in the range of corresponding values for high performance and possibility fabricated n-type thermoelectric leg.

Open access

Dragoş Viorel Brezoi

Abstract

The paper presents a micro encapsulation method of α-Fe2O3 nanoparticles in PEG4000. A suspension of α-Fe2O3 nanoparticles and dissolved PEG is sprayed through a nozzle at atmospheric pressure. After rapid expansion, core-shell composite microparticles that don´t tend to agglomerate are obtained. Structure and morphology were investigated by electronic microscopy (TEM and SEM), X-ray diffraction (XRD), and spectral technique (UV-Vis and FTIR).

Open access

S. Orboiu, C. Trocan and H. Andrei

Abstract

A desideratum of the society, not only in Romania, is the efficiency of the electricity consumption and its passage on green energy in a bigger proportion. This can be achieved by research on various topics chosen from different areas of the economy. One of the most widespread public institutions is education, which is why the results obtained from the research of such a subject can bring major benefits to the entire society. In general, the structure of pre-university education institutions is similar, with classrooms, laboratories equipped with the same types of electric consumers, and very close heating systems. This article proposes a method of monitoring the electrical energy and consumption parameters of a pre-university education institution in Romania. The results obtained are compared to the energy quality standards and will be the basis for a PV system that will be designed to ensure the entire energy consumption of the institution.

Open access

G. Predusca and M. Bogdan

Abstract

Intelligent Transport System (ITS) is a worldwide movement meant to use advanced technology to make the ground transport systems more efficient, clogging-free, more secure and less polluting. The present technologies permit the development of applications for traffic monitoring in a semaphored crossroads. The solution proposed is a low-cost one, using FPGA DE0 development platform. The implementation and simulation of the application have been realized in Quartus II 13.1 and the diagrams corresponding to the outputs and inputs have been obtained using ModelSim- Altera 10.1d.

Open access

Emil Cazacu, Lucian Petrescu and Maria-Cătălina Petrescu

Abstract

In modern low-voltage electrical installations, the predictive maintenance of the major electrical equipments involved in the power delivery process (transformers) or in the conversion of the electrical energy (especially electric motors) becomes mandatory. Thus, a high level of reliability and safety is assured for both the electric facility and operators. The proactive maintenance is to be non-invasively performed and mainly requires an infrared (IR) thermographic inspection and power quality analysis of the installation loads. A vibration investigation is also necessary for the motor drive systems. The paper critically studies the first two main maintenance procedures revealing their main characteristics, performances and limits. A case-study presents a 1000 kVA distribution transformer that supplies a bakery facility that comprised mainly heaters and inductions motors as loads.

Open access

Dorin Angelescu and Gheorghe Ion Gheorghe

Abstract

As a result of the scientific concerns of the Doctoral School of Mechanical Engineering and Mechatronics at Valahia Târgovişte University in the field of robotics dedicated to security and surveillance, the scientific work "Intelligent Cyber- Mixmechatronic Micro-System for Monitoring and Controlling the Security and Surveillance Robots" is in the testing and experimentation phase, within the doctoral (industrial) thesis "Studies, research and contributions regarding the realization of a smart mecatronic robot for security and surveillance applications". The scientific work results in a highly efficient cybermixmecatronic system, unique in Romania, which will be used to control the mechatronic security and surveillance robot, respectively the propulsion and control of its displacement. The robot is controlled through Artificial Intelligence, using the Internet of Things (IoT), which is why the Intelligent Motion Control system must be optimized both in terms of response speeds and energy. At the same time, due to the varied and possibly unstable conditions of the displacement field, the system must meet stringent criteria of reliability, resilience, weather, stability and redundant solutions for on-site repair of potential failures during missions. The cybermixmecatronic system designed to move the robot must carry it safely at the mission site so that it can then return it back to the Command and Control Center. In the paper will be presented the original solution, applicable with minimum of specific modifications (according to the chassis used), to any type of robot requiring both operator-controlled or autoguid control. Thus, a complex project will be realized combining into a unitary Mechatronics, Integronics, Cyber-Mixmechatronics, Artificial Intelligence and Information Technology.

Open access

Helga Silaghi, Maria Gamcova, Andrei Marius Silaghi, Viorica Spoială, Alexandru Marius Silaghi and Dragoş Spoială

Abstract

An electric vehicle (EV) uses an electric motor for traction and chemical batteries, superconductors, combustion cells and / or inertial masses as energy sources. To avoid problems regarding the accuracy of the mathematical model of the system, the use of artificial intelligence in electric drives is a viable alternative. Among other advantages of using artificial intelligence in the electric drive system, it can be emphasized that its application reduces the design time and leads to avoiding problems with the introduction of the mathematical model in the system control algorithm. This paper presents several case studies of electrical vehicles and some considerations about intelligent control of EVs. Finally some experimental results that compare classical control system with fuzzy logic control system for EV are presented.