|
This issue of the RECENT® journal was edited and multiplied with support of: CONTENTS
Practical Solutions for Solving the Negative Net Situation in the Case of Industrial Enterprises in Romania» Abstract Restoring the financial balance is a frequent topic in industrial enterprises, especially in the economic crisis. Widespread reduced sales amid employment of large debts to finance investments and operating cycle alongside other influence factors can lead to the development of such a situation. Specialized literature recommends restoring the financial balance through a set of measures. Most of them, however, have only a theoretical nature, as their implementation as such in the real economy does not lead to results. This article proposes a selection of these solutions, from the practical content perspective. » Keywords net situation, indicator, negative case, financial balance, industrial enterprise
The Use of the Biomass as Solid Combustible» Abstract The paper presents a research in the area of the wood thermal properties. The main aim of the paper consists on determination the thermal proprieties of biomass according to the moisture content of the wood that result from the burning process. The results obtained after biomass researching highlight the efficiency of biomass use like solid combustible for thermal installations. An important conclusion of wood combustion consists in that the wood biomass used in thermal furnaces had to need moisture content about 10-12% and this moisture content not to exceed 20%. Higher moisture content gives low calorific power that will bring to an inefficient using of wood like a solid fuel. » Keywords biomass, combustion, heat, energy
The Verification by Thermal Analysis of the Software SIM-3D» Abstract The soft designed to simulate the casting solidification, created by Transilvania University of Brasov is experimentally verified and the results are presented in this paper. The verification was carried out by thermal analysis. A cubic sample part with the dimensions 40 × 40 × 40mm was cast. The temperature variation in the central points of the casting was determined through simulation and experiment. The simulation results were compared with the experimental ones. Thus, the validity of the software was confirmed. » Keywords solidification simulation, thermal analysis, experimental verification
Morphing Concept of UAVs of the Swept Flying Wing» Abstract A special class of unmanned air vectors is the flying wings, which are to be found in the areas of interest to the same extent as the conventional design aircraft. The tailless design of unmanned aircraft brings compact geometry and manoeuvrability advantages with generation of 3D evolutions. Although the benefits of the morphing concept are highlighted from the aerodynamic point of view, the technical achievements are still a critical issue. This article aims at analysing the influence of constructive twist and of twist morphing on the performance of swept flying wings. » Keywords swept flying wing, morphing wing, aerodynamic analysis
Usage of "Selective Laser Melting" Technology Capabilities Implementation for Teeth Implants Metal Construction in TU-Sofia» Abstract This paper reviews a possible application of the method of Selective Laser Melting (SLM) for designing and producing a dental implant - metal dental "cap" which is the foundation for a dental metal ceramic crown. First, a patient’s measurements are taken and a gypsum model is made and then scanned. Thereafter a precise virtual model is created by a specialized dental CAD system. It is followed by operations using another software package in order to create Operation Control Program for the equipment applying the SLM method. Finally, there comes a real physical model which is precise enough and has the desired quality. The life cycle of this progressive process of operation is significantly reduced compared to traditional approaches. » Keywords dental, implants, rapid prototyping, selective laser melting
Determination of the Thermal Expansion Coefficient for a New Type Alloy Steel» Abstract The subject of research in the present paper is the experimental determination of the thermal expansion coefficient for a definite type of steal at high temperatures. The presented methodology is proved by investigation of a new type of steel. » Keywords thermal expansion, steel, residual stress
Implementation of PWM Soft Single Switched DC-DC Converters with Coupled Inductors» Abstract This paper proposes a novel family of pulse width modulation of soft-single-switched dc-dc converters without high voltage and current stresses. These converters do not require any extra switch to achieve soft switching, which considerably simplifies the control circuit. In all converter family members, the switch is turned on under zero-current condition and is turned off at almost zero-voltage condition. From the proposed converter family, the boost topology is analysed, and its operating modes are explained. The proposed circuit is simulated using MATLAB/Simulink. » Keywords soft switching, zero voltage switching, zero current switching, PWM converters, MATLAB/Simulink
|
|
|
