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In this paper, we deal with comparative analysis of cryptocurrency wallets and traditional wallets. In addition to security analysis, we will observe the most important elements that should ensure a high level of social acceptability. In that regard, we will make a brief overview of the existing mechanisms for disposing a funds expressed in traditional currencies as well as for crypto currencies. Under the traditional safe keeping mechanisms and the disposal of cash, we will consider systems based on payment cards, payment by cash and payments over the internet. The use of digital wallets is reflected in various characteristics. The convenience of using the ability to execute a mobile phone transaction in matter of seconds. Efficiency is reflected in the speed of transaction execution. This paper describes the current state of digital wallets on the market, the choices of a better solution for purchasing and using digital wallets, security of digital wallets and future trends in their development.

This paper presents the testing of the durability of concrete where a part of cement was replaced with ground panel cathode ray tube glass (CRT) finer than 63 µm. The percentage of cement replaced with glass is 5%, 10%, 15%, 20%, and 35%, by mass. The highest percent share of mineral admixtures in CEM II (Portland-composiste cement) cement was chosen as the top limit of replacement of cement with glass. In terms of the concrete durability, the following tests are performed: freeze-thaw resistance, freeze-thaw resistance with de-icing salts-scaling, resistance to wear according to the Böhme test, sulfate attack resistance, and resistance to penetration of water under pressure. A compressive strength test is performed, and shrinkage of concrete is monitored. In order to determine the microstructure of concrete, SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive X-ray Spectroscopy) analyses were performed. The obtained research results indicate that the replacement of a part of cement with finely ground CRT glass up to 15% by mass has a positive effect on the compressive strength of concrete in terms of its increase without compromising the durability of concrete. The results obtained by experimental testing unequivocally show that concrete mixtures made with partial replacement (up to 15%) of cement with finely ground CRT glass have the same freeze-thaw resistance, resistance to freeze/thaw with de-icing salt, resistance to wear by abrasion, and resistance to sulfate attack as the reference concrete. In terms of environmental protection, the use of CRT glass as a component for making concrete is also very significant.

Introduction. The aim of the study was to analyze the tibial tunnel position after anterior cruciate ligament reconstruction. Material and Methods. The study included 830 patients who underwent this operative procedure. There were four times more male than female patients. The tibial tunnel placement was analyzed on frontal and lateral radiograph images of the knee joint. Results. The average frontal tibial index was 55% (35 -68%), the average frontal tibial angle was 75 degrees (58 -90), the sagittal tibial index was 30% (15 -52%) and the sagittal tibial angle was 68 degrees (50 -89). Conclusion. A significant deviation from these values may potentially lead to failure of the anterior cruciate ligament reconstruction. SažetakUvod. Studija ima za cilj da analizira položaj tunela na golenjači nakon rekonstrukcije prednjeg ukrštenog ligamenta. Materijal i metode. Istraživanje je obuhvatilo 830 pacijenata kojima je izvršena rekonstrukcija ligamenta. U uzorku smo više od četiri puta imali zastupljene muškarce. Položaj tunela na golenjači analiziran je frontalnim i bočnim radiografskim snimcima kolena. Rezultati. Prosečna vrednost frontalnog tibijalnog indeksa iznosi 55% (35-68%), frontalnog tibijalnog ugla 75 stepeni (58-90), sagitalnog tibijalnog indeksa 30% (15-52%) i sagitalnog tibijalnog ugla 68 stepeni (50-89). Zaključak. Značajnija odstupanja od navedenih vrednosti potencijalno mogu dovesti do neuspeha rekonstrukcija prednjeg ukrštenog ligamenta. Ključne