Uniform indications for electric consumers classifying are determined according to their technological signs and the physical forms of electrical energy conversion. Levels of consumption in electrical consumers are defined, on the basis of which 29 indexes for investigation, evaluation and comparison of the energy efficiency in electric drives are systematized. The indexes are distributed into 6 groups. Dependencies are defined and methods are developed for determination of the indexes system. An aggregate mathematical model for monitoring and evaluating the energy efficiency of grouped electric drives is synthesized. Case-study results for a typical belt-conveyor system in a thermo-electric power plant are obtained.

The paper presents the construction of an air-jet ultrasonic aerosol generator that allows adjustment of the dispersing jet. It shows the calculation methodology which includes an air-jet ultrasonic generator and the dosing chamber of the atomized liquid. It is considering using this type of air-jet ultrasonic aerosol generator for cleaning and antimicrobial treatment of surfaces covered with biofilm in the food industry. High antimicrobial resistance of microorganisms in biofilms in the food industry is influenced by the failure of an agent to penetrate inside the biofilm.

During the latest years, the robots that include mechanisms with Delta 3DOF parallel structure attracted the attention of the university research centers due to their unexploited potential. Besides the advantages given by the Delta 3DOF parallel structure, there is a series of disadvantages too. A significant disadvantage is the fact that the workspace is limited. Under these conditions, the studies on determining and improving the workspace got intensified lately. This work is presenting a study on determining the workspace of a parallel structure Delta 3DOF, by using a method that digitizes the angular position parameters of the active kinematical couplings.

This paper presents in brief an own application (numerical code) for quick design of the turbo machines impellers. Based on this numerical method, this paper analyses the influence of the blades’ angles on the radial impeller geometry from the centrifugal pumps: the influence of the inlet and outlet angles of the blades over the hydraulic channel size, over the number of the blades and over the blades’ angular extension. In centrifugal pumps design, a special attention must be given of the impeller inlet and outlet angles. These influences include also the pump efficiency, for 1-2 percent. The impeller design methods starting from the pump flow, the head, the rotation speed and ranging blades inlet and outlet angles, gives completely the impeller geometry - the suction and discharge diameters of the impeller, the number of blades and the size and shape of the hydraulic channel and estimates the efficiency for centrifugal pumps. Once the impeller geometry established, the dates were imported in ANSYS code, for graphical design and 3D visualization of the radial impeller, also for the streamlines flowing visualization.

The aim of this study is to justify a generalized basis model for investigating, evaluating and comparing the energy efficiency of the individual and the grouped mechanical handling machines and systems. Based on a conducted analysis and developed model technological schemes of the systems for continuous transport, dependencies are drawn for determining the basis power and minimizing the potential energy losses in loads passages, the losses of height and potential energy in the systems’ auxiliary elements as well as the total energy losses. Additional indices for basis evaluation of the energy efficiency of the continuous-transport-systems technological schemes, regardless of the systems’ type and scope, are developed and systematized.

The paper analyzes stresses in an area of tension-type with geometric discontinuity concentrator. The geometric discontinuity is a hole located in a thin plate of finite dimension. The stresses and their variations were determined using the finite element method (FEM). Stresses values obtained with FEM, were used as basic data on the method of least squares to determine an analytical relationship, for calculating the coefficient of stress concentration. Relationship obtained by this method of calculation is compared with those in the technical literature.

The paper discusses the case of an annular plate, being under the action of a radial variable temperature field, but constant on its thickness. In the conditions of the outside outline embedded and that inside free, the expressions of the radial and annular stresses, respectively the radial displacement relation, are specified. The loading is considered below the yield temperature value.

Aviation maintenance IS physical topology network of “star shape” model consists of several LAN networks (Airline company, Overhaul facility, branch offices of airline company and warehouse of spare parts), which are all interconnected to central server by the means of modems and concentrators.

Fibreglass-reinforced polyester (GRP) is the most widely used composite material in the ship building industry and requires careful study in point of mechanical characteristics. This article presents the collective experience related to behaviour in different situations of GRP loading. We considered three cases manufacturing for GRP: layers with mechanical characteristics for each layer, composite (the material is considered isotropic but with layers and same mechanical properties for all layers), and isotropic plates.

Realization of brazed joints involves the use of different joining materials. These joints are designed for various industries including the machine building and special industries such as aeronautics through the use of ceramics and metal brazing joints. Due to differences in material properties of brazing, the thermal expansion, different wetting and dispersion, residual stresses can occur in the joint. These residual stresses can be reduced through proper choice of brazing materials, fluxes and brazing temperature.

This paper presents a study about the influence of the lubricant temperature on the functioning of hydrostatic guidance systems of machine tools. The quality of the working fluid is especially important in the functioning of the hydrostatic guidance systems; during the functioning, it is subjected to the long-term action of high temperatures, speeds and pressures which have a very wide range of variation. By means of the Simhydraulics program in the Matlab Simulink programming environment, was made a functional simulation pattern of a hydrostatic charging system which analyzes the behavior of the lubricant under high temperature when it passes through a restrictor.

Starting from the registration of the Evidence File of S.C. CONPET S.A. for all the damages occurred during the years 2000 and 2009 in The Domestic Crude Oil Pipeline System were emphasized the provoked damages, produced by artificial causes (unauthorized human intervention for stealing oil products). This kind of damage, which is concretized by provoked perforations, is very dangerous for the environment and for people’s life in the region, total expenses generated by the effects of the provoked damages and needed for reparation being very high. This paper tries to present the evolution and characteristics of this phenomenon and the importance of prevention and monitoring.