GENDER EFFECTS ON POSTURAL SWAY DURING RIFLE AIMING

Eight male and eight female subjects without prior shooting experience took part in the experiment. The aim of this study was to determine gender effects on postural sway characteristics and rambling and trembling components during rifle aiming. Subjects were tested with the use of force platform in quiet standing, in shooting position, and in shooting position with additional visual feedback, three times in each condition. Rambling (RM) –Trembling (TM) signal decomposition was used to process the data. Center of the pressure sway range (COPra), mean velocity (COPvel), COP root mean square (RMS), and the rambling and trembling displacement length (RMlen, TRlen) in the anterior-posterior (AP) and medial-lateral (ML) directions were analyzed variables. The results showed significant changes in behaviour due to increased levels of task difficulty effect of gender

Statistical evaluation of impact of technological factors on surface texture of WPC composites

The paper aims at evaluating the impact of technological parameters of a drilling process on the parameter of surface roughness Rz (maximum height of roughness profile) of wood-based material (WPC – Wood Plastic Composite). During drilling with tools 3.0, 5.0 and 7.0 mm in diameter, the spindle speed nc and feed rate f were changed. The evaluation of statistical significance was performed using the ANOVA mathematical tool (two-way with repetition). Using a simple conversion, it is possible to assess which of the set parameters affects the final surface quality, which serves as supporting information for the work of an engineer.Web of Science52332932

Special Issue on Cryptology : Guest Editorial

This special issue brings selected papers from the 2019 Central European Conference on Cryptology, held in Telč, June 12-14, 2019

Manufacturing technology of composite materials-principles of modification of polymer composite materials technology based on polytetrafluoroethylene

The results of the investigations into the technological formation of new wear-resistant polymer composites based on polytetrafluoroethylene (PTFE) filled with disperse synthetic and natural compounds are presented. The efficiency of using PTFE composites reinforced with carbon fibers depends on many factors, which influence the significant improvement of physicomechanical characteristics. The results of this research allow stating that interfacial and surface phenomena of the polymer-solid interface and composition play a decisive role in PTFE composites properties. Fillers hinder the relative movement of the PTFE molecules past one another and, in this way, reduce creep or deformation of the parts, reducing the wear rate of parts used in dynamic applications as well as the coefficient of thermal expansion. The necessary structural parameters of such polymer composites are provided by regimes of process equipment.Web of Science104art. no. 37

Ekonomska usporedba rezanja materijala pomoću lasera, plazme i kisika

This paper compares three of the most common processes: laser, plasma and oxygen cutting in terms of economical point of view. It illustrates the introduction of thermal cutting methods into the manufacturing of the companies with an emphasis on their productivity. This comparison can be carried out only to a limited extent what is given by many factors.U članku se uspoređuju tri najčešća procesa: rezanje laserom, plazmom i kisikom s ekonomskog motrišta. Članak prikazuje uvođenje metoda toplinskog rezanja u proizvodnju poduzeća s naglaskom na njihovu produktivnost. Ova usporedba može se provoditi samo u ograničenom opsegu, što je dano pomoću mnogo faktora.Web of Science19481781

Alkali metal distribution in composite cement pastes and its relation to accelerated ASR tests

Accelerated testing of alkali silica reaction (ASR) in concrete at elevated temperatures of 38 and 60 °C has an unknown impact on the alkali metal distribution in the cement paste. This paper investigates how the alkali metals released from hydrating Portland cement, limestone, and SCMs distribute between non-reactive and unreacted phases, C-A-S-H, and the pore solution. The SCMs investigated were fly ash and a volcanic pozzolan. The hydrate assemblage and pore solution of cement pastes cured at 20, 38 and 60 °C were analysed and related to the expansion of concrete prisms. There is little difference in alkali metal distribution at 20 and 38 °C, whereas curing at 60 °C has a large impact for the SCM containing blends. At alkali metal concentrations in the pore solution below 0.5 mol/L (Na + K) expansion of concrete was suppressed. Pore solution analysis could be used to screen new SCMs for ASR mitigation.publishedVersio