Home ] Up ] For Authors ] Peer Review ] Board ] Indexing ] Site Contents ] Recent Journal-Search ]

Home
Issues Archive
For Authors
Peer Review
Board
Indexing
Site Contents
Recent Journal-Search

Recent 44

Vol. 16 (2015), No. 1 (44), March 2015

 

This issue of the RECENT® journal was edited with the support of:


CONTENTS



  • Ionică CÎRCIU, Virgil GEAMĂN, Irinel RADOMIR, Mihai Alin POP

Theoretical Analysis Regarding the Asymmetrical Fluid Flow Applied to Helicopter Aerodynamics

» Abstract

The main topic of the present paper is the asymmetrical fluid flow application with the purpose of finding the best solutions to replace the anti-torque rotor of single-rotor helicopters using the Coandă Effect. This would significantly increase the flight performances. The research mainly aims at obtaining a controlled lateral force due to the Coandă flows through the tail boom, a force which would be useful for the stabilization of the lifting rotor applied to the flight of single-rotor helicopters.

» Keywords

Coandă effect, helicopter aerodynamics, jet thrusters, lifts

PDF

Back to Top


  • Nikolai KAZAKOV

Methodology for Preliminary Determination of the Competitiveness of Metal Structures

» Abstract

The present work shows a methodology for preparing an offer that outlines competitive advantages of the metal construction of overhead cranes when these cranes are considered as logistics machines. The competitiveness is determined by the framework construction principle of the machine.

» Keywords

logistics, metal constructions, logistics equipment, competitiveness

PDF

Back to Top


  • Vladimir MĂRĂSCU-KLEIN

Increasing Efficiency of Industrial Energy Systems

» Abstract

Increasing energy efficiency and sustainable energy system, is one of the axes of the Sectoral Operational Programme. Maximizing profit by minimizing energy costs, increasing in this way the company's market competitiveness, the main objective of an efficient energy management. Increasing energy efficiency can be achieved by improving an important parameter of the energy subsystem of production system or energy intensity (Ie). This parameter reflects the efficient use of energy in the production system and is expressed as the ratio between the energy consumption of the production system and its operating income.

» Keywords

energy, efficiency, production system

PDF

Back to Top


  • Vlad MONESCU, Ioan CIOBANU, Sorin Ion MUNTEANU, Virgil GEAMĂN, Aurel CRIȘAN

The Mathematical Modelling and Computer Simulation of Casting Solidification

» Abstract

The Department of Materials Science from Transilvania University, Faculty of Materials Science & Engineering developed some mathematical models and software for the computer simulation of casting solidification. The paper presents a mathematical model for computer simulation of eutectic alloys. The mathematical model uses the finite differences method. The mathematical model has the peculiarity that the thermic balance equation of the volume in which the cast piece is divided, is explained in nine cases. The cases are set depending on the initial and final temperature of the elements for a period of time. The mathematical models used by other software gives only a systematization of calculations depending on the initial temperature of the volume elements. In the end of the paper, data is presented regarding the structure of the software and the results (of the solidification of castings) that it provides.

» Keywords

casting, solidification, mathematical modelling, solidification simulation

PDF

Back to Top


  • Sergei SEMENOV, Svitlana GAVRYLENKO

Approximating Computer System Operation Technologies under External Action through the Brusselator Model with Perturbation in the Form of Dynamic Chaos

» Abstract

In this article, the research of the Brusselator mathematical model and its implementation in the form of the chaotic attractor is described. The hypothesis about the possibility of approximating computer system operation technologies under external action through the Brusselator model with perturbation in the form of dynamic chaos is presented and then proven through mathematical simulation. Special system and mathematical software was developed for this experimental research. The results received were evaluated and their reliability was proven by testing the data through simulation.

» Keywords

computer systems and networks, Brusselator mathematical model, dynamic chaos, perturbation of the computer system

PDF

Back to Top


  • Ana-Maria Adina ȘUTEU (BĂNCILĂ), Constantin BUZATU

A Market Study Involving the Employment of Assistive Technologies in the Case of Elderly Users with Physical Impairments

» Abstract

The emphasis in designing modern assistive systems is focused on the ability of the devices to provide a greater independence for the users. In parallel, the transition to a greater social inclusion for people with mobility impairments changed the meaning of the term disability, as it now underlines the user’s capacity to interact with the working environment. Thus, not only the improvement of assistive devices are considered, but also the development of working or living spaces that are suitable to the needs of people with physical disabilities, as well as to elderly users. Several changes occur as a result of the aging process, either in sensory processes, affecting the ability of individuals to receive information about the external environment, or in terms of the central nervous system, by slowing the reaction time. Given the increased life expectancy there raises the need for assistive devices adapted to elderly users with specific mobility impairments. Thus, taking into consideration all the above, the paper presents the need for the development of assistive technologies. A market research is also considered in order to obtain more information about users’ opinion on their current mobility aids and if there are certain features of the devices that they would improve or adapt to their disability.

» Keywords

elderly users, assistive technologies, mobility impairments

PDF

Back to Top


  • Béla VARGA, Ionuț IONESCU, Ioan CIOBANU, Tibor BEDŐ, Aurel CRIȘAN, Sorin Ion MUNTEANU

Study by Simulation and Experimental Thermal Analysis on Solidification of a Part Cast of Al-Si-12 Alloy

» Abstract

Software for solidification simulation of parts with rotational symmetry, using cylindrical coordinates was developed. This allows simulation of solidification in the volume of parts with rotational symmetry through 2D simulation. It was made an experimental verification of the results provided by software throw thermal analysis. A cylindrical sample with diameter D = 60 mm and length L = 150 mm it was cast. The part was cast in Al-Si eutectic alloy (ATSi12). Temperature variation was recorded in three-point of the casting; in the center, at 1/2R and at the surface of the part. The experimental results were compared with those determined by computer solidification simulation, using software developed. The experiment revealed that the tested software provides accurate data on castings solidification.

» Keywords

solidification, casting, solidification simulation, Al-Si-12 alloy

PDF

Back to Top


 

Home ] Up ] For Authors ] Peer Review ] Board ] Indexing ] Site Contents ] Recent Journal-Search ]