<abstract xmlns="http://www.w3.org/1999/xhtml">Dynamic logic circuits are widely popular due to a smaller number of transistors and consume less area. But the time to switch between logics is higher due to higher contention value. A new model of the logic using nMOS based keeper circuit is proposed and the performance is evaluated using Cadence tools. Comparative results demonstrate the suitability and competency of the proposed circuit.</abstract>

Department of Electrical and Electronic Engineering

International Islamic University Chittagong

Ahsanullah University of Science and Technology

A New Model of Dynamic Logic Circuit with NMOS based Keeper

<abstract xmlns="http://www.w3.org/1999/xhtml">This paper is concerned with the analysis of the tracking capability of Relay Feedback Control Systems (RFCS). The envisioned application is the generation of Pulse-Width-Modulation (PWM) with variable duty-cycle and frequency known also as Duty-Cycle Modulation. In general, two main issues have to be solved with RFCS when used for regulation and tracking. The first issue concerns the determination of autonomous self-oscillations which are generated by the closed loop. The second issue concerns the determination of the relationship between the reference and the output signals. However, if the first issue has beneficiated from different approaches and has been solved particularly in case of zero reference signal, the second issue has got insufficient theoretical results because of mathematical difficulties for obtaining analytical expressions. Considering these reasons, a deep analysis of RFCS constituted of a hysteretic relay and linear systems of first order is presented. Analytical expressions relating self-oscillations and output mean values with respect to the reference signals are obtained. The analysis of these relationships led to infer some conditions under which the relay feedback control can generate commands for regulating and tracking reference signals. It highlights also the key role played by the hysteresis band width for applications based on RFCS. Our analysis, exploiting the analytical expressions, can be used to achieve a complete design for power converters. Moreover, simulation and experiments have confirmed our results.</abstract>

Laboratory of Applications of Advanced Technology (LATA)

Generation of PWM Based on Simple Relay Feedback Systems

<abstract xmlns="http://www.w3.org/1999/xhtml">Despite the advanced technologies used in recent years, the lack of robust systems still exists. The automated steering system is a critical and complex task in the domain of the autonomous vehicle’s applications. This paper is a part of project that deals with model-based control strategy as one of the most common control strategies. The main objective is to present the implementations of Model Predictive Control (MPC) for an autonomous vehicle steering system in regards to trajectory tracking application. The obtained results are analysed and the efficiency of the use of MPC controller were discussed based on its behaviour and performance.</abstract>

Faculty of Mechanical engineering and Informatics

Model-Based Control Strategy for Autonomous Vehicle Path Tracking Task

<abstract xmlns="http://www.w3.org/1999/xhtml">This article is based on the quantitative study of reliability, maintainability, availability (<italic>RMA</italic>), on the Pareto diagram (<italic>ABC</italic>) and on the analysis of the failure modes and their impact on criticality (<italic>FMECA</italic>). The developed approach aims, at first, implementing two optimization procedures (code development, Simulink modelling in MATLAB) and using two methods (graphical, analytic) of the Weibull parameters. The results obtained via code (which is based on the Weibull graph method of two parameters) are a bit divergent. The evaluation criteria are rather far from that of the model (which is based on the maximum likelihood of three-parameter Weibull distribution). This will allow to locate the critical elements, and to determine the systematic preventive time of replacements. An application case validates the proposed study objective.</abstract>

Department of Hydrocarbon production, Faculty of Hydrocarbons and Energies Renewables and pieces of land

Faculty of Engineering Sciences University of Annaba

The Impact of Integrated Maintenance Actions Optimization on Strategic Machines Lifetime

<abstract xmlns="http://www.w3.org/1999/xhtml">In the industrial sector, maintenance of production facilities plays an important role to carry out production by increasing the reliability and availability of the production process. Predictive maintenance strategy seems adequate to anticipate the failure and degradation of the state of such equipment. A reliability study is needed to quantify indicators to describe the functioning of any system over time. In this paper, we present the results of a stochastic modeling conducted on the analysis of the availability of motor-pump system, installed in a cooling circuit in an industrial complex. The equipment considered in this study is composed of four subsystems. The proposed model is a dynamic Markovian approach, for the purpose of a comparison with the analytical calculation in terms of the indicators’ evaluation of the dependability of the studied system, including instant availability. The different states of the system components and the transition functions between these states have also been characterized. The results of availability obtained by the model are well correlated with those calculated analytically, confirming that the proposed model is very powerful, it will help predict the future states of the system, in order to predict any necessary preventive maintenance actions.</abstract>

Department of Mechanical Engineering, Faculty of Technology

Department of Mechanical Engineering, Faculty of Technology, LRPCSI Laboratory of research

Study of Reliability in a Repairable System by Markov Chains

<abstract xmlns="http://www.w3.org/1999/xhtml">The factors which influence the performance characteristics of a hammer drill are examined; drilling data are analyzed to determine these factors. Methods for selecting the appropriate drilling are also highlighted. Two models are used in order to compare optimal drilling parameters. The main one is the machine output.</abstract>

Electromechanical Systems Laboratory, Department of Electromechanical

Improvement of the Hammer Drill Performance (Algerian Quarries Conditions)

<abstract xmlns="http://www.w3.org/1999/xhtml">Species separation in heterogeneous porous media is a field of interest of many industrial activities. In our investigation, the effect of a single discrete fracture on the thermosolutal convection coupled with the Soret effect have been analyzed. The main results show that the fracture can greatly affect the behavior of the thermogravitational flow and might play a positive role to the separation caused by the Soret effect. Furthermore, the fracture tilted to the cold wall causes a large separation compared to the one tilted to the hot wall with the same angle. Therefore, the separation process could be greatly improved.</abstract>

Thermosolutal Convection in a Porous Medium Cavity Subjected to Heat and Mass Flux: A Discrete Fracture Effect

<abstract xmlns="http://www.w3.org/1999/xhtml">The manuscript focuses on the study of corrosion resistance in NaCl medium of a 304L type stainless steel after application of protective nickel-based and cobalt-based coatings produced by powder spraying under a continuous CO2 laser (10.6 µm wavelength) beam. Using polarization and electrochemical impedance spectroscopy methods, the results found confirm that metallic coatings produced under high energy beams offer excellent protection up to an efficiency of <italic>E</italic> = 98.12% in aggressive environments with salinity to 3%.</abstract>

Department of Petrochemistry and Process Engineering, Faculty of Technology

Chemical and Environmental Engineering Research Laboratory, LGCE

Corrosion Resistance of Coatings Produced by Spraying Powders Under a Laser Beam in a Saline Environment NaCl 3% by the Electrochemical Method

AHEAD OF PRINT

Volume 15 (2023): Issue 1 (December 2023)

Volume 14 (2022): Issue 1 (December 2022)

Volume 13 (2021): Issue 1 (December 2021)

Volume 12 (2020): Issue 1 (December 2020)

Volume 11 (2019): Issue 1 (December 2019)

Volume 10 (2018): Issue 1 (December 2018)

Volume 9 (2017): Issue 1 (December 2017)

Volume 8 (2016): Issue 1 (December 2016)

Acta Universitatis Sapientiae, Electrical and Mechanical Engineering

 Series Acta Universitatis Sapientiae, Electrical and Mechanical Engineering surveys in various fields of Electrical and Mechanical Engineering. All papers are peer-reviewed. The language of the journal is English.  Why submit Strict review, open access, various fields covered.  Why subscribe and read Series Acta Universitatis Sapientiae, Electrical and Mechanical Engineering publishes only original papers and surveys in various fields of Electrical and Mechanical Engineering. All papers are peer reviewed. Rejection Rate   40%   Archiving  Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.  Plagiarism Policy  The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 