In this work the corrosion behaviour of Ni-Ti (Nitinol) shape memory alloy was studied using different electrochemical techniques including open circuit potential (EOC), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Samples made from nitinol alloy with diameter of 4 mm were used for microstructural and corrosion investigations. Testing solution was 0.9 % NaCl solution at pH=7.4, and temperature 37 °C. Microstructural analysis was performed by the optical and electron scanning microscopy (SEM) equipped with energy dispersive spectrometry (EDS). High values of the oxide film resistance (Rox) and the low value of corrosion current density (icorr) indicated high corrosion resistance of Ni-Ti alloy, but relatively low value of breakdown potential (Eb) indicates the possibility of development localised corrosion attack on the alloy surface. Size of pits was from 10 to 100 m and surface inclusions were initiation sites for the pitting corrosion.

Introduction: Today’s lifestyle is characterized by increased intake of calories with reduced physical activity, which benefits a real epidemic of obesity in the population. The increase in the prevalence of hypertension in the population follows a significant increase in the prevalence of obesity. Parallel to the trend of increasing the number of older population with increased cardiovascular disease. The aim: The aim of our study was to determine the value of body mass index and determine the correlation of obesity and arterial hypertension. Material and methods: The study was conducted in family medicine Clinic of the Primary Health Care Center Zenica. Out of 600 patients of both sexes aged over 18 years, randomly are formed groups of 188 patients with hypertension and 189 patients without hypertension of the same gender and same age. The study included patients with primary or essential hypertension, and excluded patients with secondary hypertension, hypertension due to renal disease, pheochromocytoma, coarctation of the aorta, as a result of taking oral contraceptives, corticosteroids, and cocaine. We used the method of anthropometric measurements (body weight, body height from which is calculated the body mass index) measurement of blood pressure with the statistical data processing at the significance level of p <0.05. Results and discussion: The increased value of BMI in the sample with hypertension are present in much higher percentage (87.23%), compared to the tested sample without hypertension (60.10%). In patients with hypertension, the highest percentage (51.06%) of the respondents has the BMI in range between 25 and 30, then BMI in the range between 30 and 35 (25%). BMI of 35-40 have 6.38% of patients, and 3.72 patients BMI over 40. In patients without hypertension was significantly smaller percentage of respondents in the previous group (39.15%) with a BMI in the range 25-30, then BMI in the range between 30 and 35 (18.51%). BMI of 35-40 had 3.17% of respondents, and 1.05% of patients had BMI over 40. Correlation between groups of patients with and without hypertension compared to the value of BMI indicate the presence of strong positive correlation (Rho = 0.737). Correlation between groups of subjects with hypertension and without hypertension compared to triglycerides was statistically significant (Rho = 0.123).

Despite the complexity of the Human Visual System (HVS), research over the last few decades has highlighted a number of its limitations. These limitations can be exploited in computer graphics to significantly reduce computational cost and thus required rendering time, without a viewer perceiving any difference in resultant image quality. Furthermore, crossmodal interaction between different modalities, such as the influence of audio on visual perception, has also been shown as significant both in psychology and computer graphics. In this paper we investigate the effect of beat rate on temporal visual perception, i.e. frame rate perception. For the visual quality and perception evaluation, a series of psychophysical experiments was conducted and the data analysed. The results indicate that beat rates in some cases do affect temporal visual perception and that certain beat rates can be used in order to reduce the amount of rendering required to achieve a perceptual high quality. This is another step towards a comprehensive understanding of auditory-visual crossmodal interaction and could be potentially used in highfidelity interactive multi-sensory virtual environments.