Intenzitet habanja kod različito toplinski poboljšanog nodularnog lijeva

In the paper we investigate the relationship between the wear intensity of two nodular cast irons and their heat treatment conditions. Disks tempered by austempering and isothermal procedure were used. The wear test was realized by using Pin and Disk tribometer. Measurement of the disks wear, after the contact for duration of 30 min, was done by the PQ meter. The quantity of the wear products in lubricant is determined by the PQ index. The best wear resistance posses the disk isothermally tempering with 30 minutes holding at 390 °C temperature.U ovom radu je ispitivana zavisnost između intenziteta habanja dva nodularna lijeva kao i uvjeta pri njihovoj toplinskoj obradi. Uzorci za ispitivanje nodularnog lijeva su bili poboljšani klasičnim i izotermalnim postupkom. Ispitivanje intenziteta habanja je realizirano uz pomoć Pin on Disc tribometra. Mjerenje pohabanosti diska, nakon trenja u trajanju od 30 minuta, je obavljeno na PQ metru. Količina čestica nastalih kao produkti habanja, u sredstvu za hlađenje i podmazivanje je određena PQ indexom. Najveću otpornost na habanje posjeduje disk izotermalno temperovan na 390 °C u trajanju od 30 minuta

Neural Network Modeling of Cutting Fluid Impact on Energy Consumption during Turning

This paper presents a part of research on power consumption differences between various cutting fluids used during turning operations. An attempt was made to study the possibility of artificial neural network to model the behavior function and predicting the electrical power consumption. Friction factor of examined cutting fluids was also measured to describe a more complete picture of investigated cutting fluids characteristics. It was discovered that wide spectrum of characteristics is present in today’s market and that artificial neural networks are suitable for purpose of modeling the power consumption of the lathe during machining. This paper could be used as a foundation for later database building where it would be possible to predict how certain cutting fluid will behave in a specific machining parameter combination

Energy efficiency cart modeling of solar energy collectors by genetic programming

Uniquely constructed technical solution of solar energy collector is presented in this paper. It presents a great breakthrough in the field of energy efficiency and successful exploitation of renewable energy sources. Principle of this high-temperature energy storage enables the energy accumulated from the sun to be yielded when necessary and continuously, 24 hours a day and 365 days a year. Furthermore this paper is containing a modeling of sun irradiance, generated energy intensity for flat solar panel and for Prof. Petrovic concentrator. Modeling is made with genetic programming and it is found out that genetic programming is suitable method for modeling of energy intensity. It offers results which are within acceptable tolerances while maintaining ease of use and short computational time. Genetic programming yielded results of 12,97%, 14,6% and 9,25% average percent error for irradiance, flat solar panel and Prof. Petrovic solar concentrator respectively. [Projekat Ministarstva nauke Republike Srbije, br. TR 35015