Predrag Dašić

Influence of New Technologies on Higher Energy Efficiency of Hydrostatic Devices and Systems

Both the experience and data from literature show that current hydraulic components and development of electric control systems have significantly increased energy efficiency. Therefore, all world manufacturers of hydraulic devices and systems use advanced technologies and methods with the final aim to integrate them into mechanical system. Energy losses, made as a result of all forms of friction, are minimized. It is safe to say that modern growth is based on development of new materials and accompanying technologies as well as on control techniques, i.e. on mechatronic approach and design of such systems. Ecological requirements and legal regulations should not be neglected, either. Based on the above issues and available data the authors of the paper try to answer the following question: What is the position of once famous factory of hydraulic devices from Trstenik in comparison to other competitive factories worldwide?

Mathematical Modeling of Thermomechanical Processes in the Boundary Layer of a TiC/TiN-Coating Applied to Nitride Ceramic

The main features are established for thermomechanical processes at the boundary of layers of TiC/TiN-coating applied to nitride ceramic proceeding under action of thermal and combined loads. The effect of basic ceramic structural element material on temperature and stresses formed in contact underlayers of TiC/TiN coating under action of these loads is revealed.

Improving Patient Safety in Hospitals through Usage of Cloud Supported Video Surveillance

BACKGROUND: Patient safety in hospitals is of equal importance as providing treatments and urgent healthcare. With the development of Cloud technologies and Big Data analytics, it is possible to employ VSaaS technology virtually anywhere, for any given security purpose. AIM: For the listed benefits, in this paper, we give an overview of the existing cloud surveillance technologies which can be implemented for improving patient safety. MATERIAL AND METHODS: Modern VSaaS systems provide higher elasticity and project scalability in dealing with real-time information processing. Modern surveillance technologies can prove to be an effective tool for prevention of patient falls, undesired movement and tempering with attached life supporting devices. Given a large number of patients who require constant supervision, a cloud-based monitoring system can dramatically reduce the occurring costs. It provides continuous real-time monitoring, increased overall security and safety, improved staff productivity, prevention of dishonest claims and long-term digital archiving. CONCLUSION: Patient safety is a growing issue which can be improved with the usage of high-end centralised surveillance systems allowing the staff to focus more on treating health issues rather that keeping a watchful eye on potential incidents.

ONE VIEW TO THE QUALITY SYSTEM ACCORDING TO THE SUBSYSTEM OF PREPARATION OF TECHNICAL ASSETS

Effective manufacturing, high and stable quality products and services in continual production, only inadequate conditions of planning, systematization and realization corresponding activities in the quality assurance system (QMSQAS) of the factory (supplier, manufacturer) can be obtained. In this paper, the parameters of quality of development, design, production and service are considered. The complex model of PMAS-CLR (preventive maintenance according to state with a controlled level of reliability), which yields guarantee to target behavior of realized products in operational conditions, is emphasized. Keywords— quality system (QS), quality assurance (QA), research & development (R&D), reliability, maintenance, PMAS-CLR model.

Effectiveness Rising of Wheel-Pairs Renewal by Cup-Tip Cassette Tool

The results of studies of the load effect on the cylindrical surface of the fixing holes of the insert on the durability and dynamic characteristics of the improved design of split cup-tip tool for wheelset processing are presented. It is approved that the radial force on the cylindrical surface of the fixing holes of the insert is of a significant effect on the stiffness characteristics of split cup-tip tool.

One Approach to the Development of Plant Voždovac Database

The paper presents the main characteristics of heating plant Voždovac, methods of data acquisition and storing them in a database. Special attention is paid to creating queries and reports. The database is comprehensive because in addition to the measured and calculated data it contains all parameters related to the number of heat transfer stations, their capacity, built-in device by which with most heating plants is equipped in our country and abroad, and the state of consumed heat energy. The contribution of the database to efficient operation of heating plant Voždovac and maintenance of its facilities is emphasized. The database operation is illustrated by explaining the mode of certain forms, queries and reports.

Numerical Investigation of Thermal Stresses in Surface Layer of Si3N4 Ceramics in Laser Processing

The laser processing has the ability for effective machining of ceramic materials because of high energy beam acting on a very small area. The stress-strain state of surface layer of Si3N4 ceramics in laser processing was investigated with the use of finite element method to compute the temperature and stress fields. The effect of heat flow on thermal stresses was discussed in terms of the results of the numerical experiment.

Modelling of Influence of Intensive Heat Flow on Stress Inhomogeneity in Ceramic System TiC-Y2O3-Si3N4

Modelling is necessary for the control of exploitation process of ceramic details to achieve improved reliability and high productivity. Of most importance in exploitation of nitride ceramic details is the establishment of models that relates external loading with stress-strain state through consideration of mechanical and thermal interactions between the ceramic structural elements. This paper evaluates several interrelationships between heat flow and stress inhomogeneity in nitride ceramics which revealed the results of simulation analysis.

Reliability Analysis of the Hydro-System of Excavator SchRs 800 Using Weibull Distribution

In this paper is given the use Weibull distribution (WD) as theoretical reliability model for analysis of the hydro-system of excavator SchRs 800, which is accepted on the basis of Pearson (χ2), Kolmogorov-Smirnov (KS) and Cramér-von Mises (CvM) goodness-of-fit tests. The time of work without failure of the hydro-system of excavator SchRs 800 for accepted Weibull model of reliability for probability of 50 % is T50%=0.3417⋅103 [h], for probability of 80 % is T80%=0.1884⋅103 [h] and for probability of 90% is T90%=0.127⋅103 [h].