In this paper impact of the tower arrangements on the mitigation of the increased values of the electric field intensity at high-voltage transmission line conductors was investigated. Several configurations of high-voltage towers (horizontal, delta, reverse delta, vertical and split-phase configurations) were analyzed. It assumed that the same height of the lowest phase conductors above the ground and the same value of the connected 400 kV voltage. The calculations were carried out for the values of the electric field intensity on the surface of the conductor and its immediate vicinity. A charge simulation method was used to calculate the electric field intensity on the surface of the stranded conductors and their immediate vicinity.

Abstract In this paper analysis of the origin and mitigation measures of increased electric field at high voltage transmission lines in the electric power system of Bosnia and Herzegovina is given. In the analyzed period (2010–2017) in the electric power system of Bosnia and Herzegovina increased values of power frequency voltages was registered. The performed analysis shows that the increased voltages in the 400 kV nodes of the electric power system of Bosnia and Herzegovina are occurring during the night, mainly in the minimum consumption regimes. Increased voltages can occur throughout the year, but are most frequent during the spring and summer months. In the coming years, four 400 kV interconnection transmission lines to Serbia and Croatia will be built. Increasing of the voltage value causes the formation of the corona as well as energy losses. Taking into account the values of the energy losses due to the corona, it is important to determine the values of the electric field on the surface of the conductors and their immediate vicinity as well as the value of the corona onset electric field in order to know their values in the electric power system and to explore ways to mitigation them from the aspect of maintenance and management costs.

ABSTRACT The main purpose of the substations grounding systems is to ensure integrity of substations equipment and safety of personnel in and outside of substation at the maximum fault currents. To meet safety requirements, grounding system should have a low as possible resistance. In order to achieve low resistance, grounding systems are designed in a way to achieve as large as possible contact surface between the grounding system conductors and the surrounding soil. On the other hand, cost – efficiency of the proposed solution must be taken into account. Therefore, to meet the technical criteria on the one hand and economic criteria on the other hand, grounding systems are composed from large number of horizontal, vertical and inclined galvanic connected unisolated conductors that in most practical cases form complex geometries. Additionally, soil in which grounding systems are placed is almost always composed of a number of layers with different electric conductivity. In this paper, numerical model based on the indirect boundary element method is presented for calculation of grounding system parameters placed into the vertically layered soil.

This paper presents the detection method and analysis methodology of dynamic stray current effects on underground pipelines based on simultaneous multiparametric measurements in combination with continuous wavelet cross‐correlation and frequency plots. Measurements presented within this paper were conducted at two locations experiencing tram induced dynamic stray currents, in the first case, on unprotected pipeline and in the second case, on pipeline under cathodic protection. On both pipelines, measurements of pipe‐to‐soil potential, lateral potential gradient, corrosion probe current, and pipeline current were simultaneously done for time period of 20 min. For both locations, the two wavelet cross‐correlation spectrograms for the quantities: lateral potential gradient and probe current versus pipe‐to‐soil potential show that 5% statistical significance levels are in periods between 16 and 128 s. Time spans and period lengths of observed cross‐correlations on spectrograms reflect the stray current influence that may be linked to specific events, such as passing of trams. On the other hand, frequency plots of the measured quantities give clear visual representation of the time that pipeline spends in a certain state related to the possible harmful effect of stray current and also show the degree of cathodic protection beneficial effect.

Aim To establish the presence of two risk factors, smoking and alcohol use, for non-communicable diseases among students at the University of Zenica. Methods The research was conducted at eight schools of the University of Zenica in the academic year 2016/2017 during the period from 1 December 2016 to 15 February 2017. The study involved 600 students 19-29 years of age (all years of study). The research was carried out with a standardized and validated questionnaire, the STEPS non-communicable Disease Risk Factors survey, developed by the World Health Organization. Results Tobacco was used by 145 (24.2%) students, 68 (46.9%) of them being males and 77 (53.1%) females (p<0.05). Males smoked 15.62 and females 13 cigarettes per day (p<0.05). On average, male participants were 16.56 years old, and female participants 16.71 when they started consuming cigarettes (p<0.05). A total of 289 (48.1%) students consumed alcohol, of whom 135 (70.2%) were males and 154 (37.7%) females (p<0.05). Conclusion There is evidence of high prevalence of smoking and alcohol usage as the risk factors for non-communicable diseases. Two levels of the prevention measures should be applied in order to reduce the prevalence of such risk factors: strategic level with a definition of the population, actors, activities, target population and anticipated results, and tactic level which will show contingency activities at the University.

In this article the summary of measurement and calculation values of low frequency electric field radiation around the high-voltage transmission lines and impact of the increased voltage values on the AC corona onset voltage gradient are presented. The measurements of the low frequency electric field radiation level were performed under the 400 kV transmission lines of horizontal configuration with standard and compact dimensions. In all cases analyzed in this article, the measurements are performed in the middle of the span, because at this point the conductors are closest to the ground. The analysis in this article has been initiated by the increased voltage values of long duration that have been registered in nodes of the 400 kV network in Bosnia and Herzegovina and the neighbouring countries during the last years. The calculation of the low frequency electric field radiation of the different configuration of the high-voltage transmission lines will be useful for determining the non-ionization radiation exposure levels of the general public in the future as well as to determine their impact on the AC corona onset voltage gradient.

The pa per dis cusses the pos si bil ity of im prov ing the char ac ter of gas surge ar rest ers. Ex am ined were: the mag netic field ef fect, the ef fect of the hol low cath ode, and the ef fect of the al pha ra di a tion source 241Am. Nu mer i cal and real ex per i ments con ducted are pre sented to gether with the o ret i cal in ter pre ta tions of the ob tained re sults. Real ex per i ments were car ried out on a model of a gas surge ar rester spa tially con structed for ex per i ments pre sented in this pa per. The model was de signed in such a way that it was pos si ble to change all the rel e vant pa ram e ters of the gas surge ar rester model. Ex per i ments were con ducted un der well-con trolled lab o ra tory con di tions. The tests were per formed with d. c. and im pulse volt age. The re sults ob tained by ex per i ments were pro cessed by so phis ti cated sta tis ti cal meth ods. The ex pressed mea sure ment un cer tainty of the ex per i men tal pro ce dure showed a high sta tis ti cal re li abil ity of the ob tained re sults. Based on the re sults of the re search, the model of a gas surge ar rester, in which the ef fect of the hol low cath ode and the ra dio ac tive source 241Am were com bined, un am big u ously proved to have the best char ac ter is tics.

Introduction: Alimentary toxoinfections represent a significant public health problem. Globalization of the market and food production, significant impoverishment of a large part of the population, and traditional approach with food preparation and consumption, cause a significant increase in the rates of population infections around the world. The epidemiological surveillance of the illness occurrence plays a significant role in monitoring and controlling the population’s burden of diseases caused by unhygienically prepared and stored food. Aim: The aim of the article is to determine the rates and trends of food related diseases in the Federation of Bosnia and Herzegovina. Results: The results of the analysis have shown that the rate of illness in the Federation of Bosnia and Herzegovina is declining but is still significantly higher than in developed western countries. Particularly great burden is on the population of the Zenica-Doboj Canton (ZDC), which can be due to the traditional relation to the preparation and storage of food, as well as to the relatively poorer economic situation in ZDC. Conclusion: We can conclude that the strengthening of the monitoring system, laboratory capacities, the availability of monitoring guides will enable responsible FBiH/Bosnia and Herzegovina institutions to better control and implement safer food practice.