This paper is dedicated to transient studies on wind turbine blade due to different types of lightning discharges. In order to select the appropriate lightning protection system, it is necessary to identify the parameters of lightning flash. Therefore, measured lightning flashes are presented and analyzed. Simulations have been conducted in EMTP - RV. In the case when lightning hits the blade of wind turbine transient voltage on tower top, voltages on tower footing resistance and on primary side of transformer are considered.

The paper presents the analytics of lightning data collected by monitoring system in real - time for the measurement of the direct lightning current (LAMS) and the lightning location system (LINET). The both systems and their operation mode are shortly described. A great number of collected data are analyzed, explained and compared. The data analyses showed the Lovćen mountain has the overall highest number of registered lightning strokes in the whole analyzed area.

This paper describes method for lightning current waveform parameters estimation from direct current measurements on remote lightning monitoring system. Proposed signal enhancemed method is based on segmentational multi-step digital signal enhancement in time domain. Performance of proposed waveform parameter estimation has been confirmed in Monte Carlo simulation of three types of synthetic signals corrupted with different levels of additive Gaussian white noise. The proposed approach for noise reduction in time domain offers satisfactory results.

This paper describes a detailed transmission line model for a transient analysis. Line surge arrester energy sharing and importance of complete transmission line modelling is explained. Lightning channel impedance and tower footing resistance are important parameters that influence line surge arrester energy duty. Therefore, energy stresses of transmission line surge arresters due to different values of lightning channel impedance and nonuniform distribution of tower footing resistance are considered.

In this paper Failure Mode and Effects Analysis (FMEA) for a large scale multirotor systems (with moving mass) based on novel system for aircraft control will be presented. This system uses four petrol engines for lift and a moving mass system to control the vehicle. Analysis presented in this paper assesses the vulnerabilities of the system during the vehicle operation. The main objective of the analysis is to understand the cause and severity of the failures that can occur to the petrol engines and the moving mass system. Our unmanned aerial vehicle system is used for environmental monitoring and maritime security developed under MORUS project funded under NATO SPS Program. The ultimate goal of our research and design is to make an unmanned aerial vehicle that can lift larger amount of load (approximately 40kg). During its operation time the unmanned aerial vehicle might fail to complete a certain assignment so failure mode and effects analysis is needed to account for such problems and to find appropriate activities to reduce the overall risk the system faces during the mission.

The power system (PS) evolves with the introduction of new technologies in the sectors of production, transmission, distribution and control of electricity consumption. The philosophy of PS control, operation and management is changing. The public low-voltage network (LVN) faces the major changes due to integration of new smart grid technologies. The integration of photovoltaic power plants (PVPPs) and Energy Storage System (ESS) in LVN is a focus of this paper. Three scenarios are considered: (1) analysis of LVN without PVPPs and ESS, (2) analysis of LVN with PVPPs, where LVN is treated as energy storage (ES), (3) analysis of LVN with PVPPs and ESS. The novel algorithm for ESS control aiming to peak load reduction is presented in the paper. Losses and voltage conditions are analyzed on all LVN buses. The slow voltage variations analysis is carried out according to the EN50160 standard. It was shown that the connection of the ESS has negligible impact on losses in LVN. Slow voltage variations are within limits defined by standard EN50160 for all considered scenarios.

Introduction: Heart failure (HF) has very high rate of repeat hospitalizations due to HF decompensation (HHFD), sometimes very shortly after discharge for acute HF. Aim: The aim of this paper is to investigate rate of HHFD and to identify their possible predictors. Patients and Methods: Total amount of 222 patients hospitalized at Clinic for heart and vessel disease and rheumatism in acute HF were followed for next 18 months for occurrence of HHFD. During hospitalization were collected demographic data, risk factors, routine laboratory tests and admission BNP (brain natriuretic peptide), discharge BNP, percentage change of BNP during hospitalization, high sensitive troponin I, CA125 (cancer antigen125) and cystatin C. Results: In next 18 months 129 patients (58.11%) reached end-point HHFD- mean time of its occurrence was 2.2 (95% CI=1.67-2.7) months. Patients with HHFD had more often arterial hypertension (HTA) (p=0.006), had higher BMI (p=0.035) and had higher values of bilirubin, admission BNP (p=0.031), discharge BNP (p <0.001), CA125 (p=0.023) and cystatin C (p=0.028). There was no difference in troponin values (p=0.095), while % reduction of BNP during hospitalization was lower (p<0.001) in group with HHFD. In univariate Cox hazard analysis HTA was positively and BMI negatively correlated with HHFD, while in multivariate Cox hazard analysis independent predictors were HTA (HR 1.6; 95% CI=1.1-2.2; p=0.018) and BMI<25 (HR 1.6; 95% CI=1.1-2.3; p=0.007). In univariate Cox hazard analysis admission BNP, discharge BNP, rise of BNP during hospitalization, CA125 and bilirubin were positively correlated, while sodium was negatively correlated with HHFD. In multivariate Cox hazard analysis there was only one independent predictor of HHFD - discharge BNP (HR 6.05; 95% CI=1.89-19.4; p=0.002). Conclusion: Arterial hypertension, BMI>25 and discharge BNP are independent predictors of HHFD. This could help us to identify high-risk patients for readmission who should be monitored more frequently and treated with sophisticated drug and device therapy.

Introduction: Several analysis for different population conclude that endothelial plasminogen activator inhibitor 1 gene polymorphism, -675 ID, 4G/5G PAI-1 (ref SNP ID: rs1799889, also described as rs34857375, has merged into rs1799762) may increase risk of pregnancy loss (PL). However, there is a disagreement as to the association 4G allele with pregnancy loss. Aim: Therefore, we decided to investigate the -675 ID, 4G/5G PAI-1 as a potential genetic factor linked to PL in European and worldwide populations. A systematic review of the scientific literature was conducted with the use of the PubMed and Scopus electronic databases (1991-present), using the following search terms: pregnancy loss, miscarriage, genetic risk of thrombophilia, rs1799889 PAI-1 gen, 4G/5G PAI-1 gene polymorphism, PAI-1 gene locus 4G/5G polymorphism. Results: Among European populations, the statistically significant association between 4G allele and recurrent PL only in Czechs and Bulgarian women was found (p<0.002 and p=0.018, respectively); while, among populations outside Europe in Iranian, Tunisian and Turkish women (each p<0.001). Conclusions: We concluded, that both in Europe and elsewhere in the world, the high frequency of 4G allele in population, is not unambiguously linked with the risk of pregnancy loss.

Introduction: Time management is an important aspect of successful leadership and involves mastering your own work and time instead of allowing them to master you. Time management is a daily process that is applied in order to rationally use time, work schedules, lists of tasks, delegation of responsibilities and everything else that helps to efficiently use time. Material and methods: This research was prospective, descriptive, analytical and controlled. There was 100 medical worker involved, who have managing jobs of different levels and 100 medical workers who do not have managing jobs, who represented the control group. The questionnaire on „time stealers“ according to Sewert. Demographic data was gathered according to the questionnaire on self construction. Results and Conclusions: Based on conducted research, it was established that there were differences in frequencies of certain „time stealers“ in managers of different levels of University Clinical Center Tuzla; the „time stealers“ are more frequent among these with shorter length of service; These differences are significantly more frequent (p<0.05) for some questions e.g. being distracted by phone calls, meetings that are held just for the sake of having a meetings, insufficient, one-way or bad communication with superiors, and have negative effects on management of business hours.

Introduction: Recent research reported that prolonged use of AET is associated with changes in bone metabolism, with consequent reduction in bone mineral density (BMD) and increased risk of fractures. Objectives: Therefore, the aim of our study was to investigate the effects of carbamazepine on serum levels of 25 -hydroxyvitamin D and on biomarker of bone formation and resorption (serum levels of osteocalcin). Material and methods: We measured serum levels of 25-OHD and osteocalcin (OCLN) in normal controls (n=30) and in epilepsy patients taking carbamazepine (CBZ) (n=50) in monotherapy for a period of at least twelve months. For each participant, mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry method. Results: The average value of vitamin D in serum was significantly lower in CBZ group than in control group (Vit D 17.03+12.86 vs. 32.03+6.99, p=0.0001). The average value of osteocalcin in serum was significantly higher in CBZ group than in control group (26.06+10.78 vs. 19.64+6, 54, p=0.004).BMD value in CBZ group was significantly lower than in control group (T. score CBZ: 0.08+1.38 vs. T. score control: 0.73+ 1.13, p=0.031; Z score CBZ:-0.05+1.17 vs. Z. score control: 0.55+0.79, p=0.015). Conclusion: AEDs are associated with bone disease, as evidenced by biochemical abnormalities and decreased BMD. Patients on long-term antiepileptic therapy, especially with enzyme-inducing agents, could benefit of routine measurement of biochemical markers of bone turnover, and BMD measurement as part of osteoporosis investigation.