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A. Mujezinović, S. Martinez, Krešimir Kekez

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.

This paper investigates the impact of accidental release of chlorine gas in surrounding areas consequences of chlorine gas leak studying the negative effects on both the environment and individuals. Chlorine and its consequences have a far more reaching effect in society that one may have imagined. The ALOHA software has been used in this paper to modelling of chlorine release. The modelling was performed for an accidental release of 3.373 tons chlorine gas from unsheltered single storied for one hour. For a typical average atmospheric condition in location, this accidental chlorine release would cause a red zone of 3.0 kilometres (AEGL-3=20 ppm), orange zone of 7.1 kilometres (AEGL-2=2 ppm) and yellow zone stretching to greater than 10.0 kilometres (AEGL-1=0.5 ppm) to downwind from the source.

Predrag Ilić, Ljiljana Stojanović-Bjelić, Z. Janjuš

Environmental noise pollution, a form of air pollution, is a threat to health and well-being. The primary aim of this study was to determine noise pollution in the urban part of the city of Banja Luka in Jovana Dučića Street (Republic of Srpska, Bosnia and Herzegovina (BiH)) by evaluating noise levels in the street. The aim of this research is also to compare the measured noise levels in the street with legislation. The measured values exceeded the level of noise allowed. Results indicated that noise level values in this area near health institution are alarming.

Urban forests are part of the public city space and have multiple significance. Various roles of greenery (health, social, aesthetic, cultural, educational, etc.) improve the quality of life in the city. Urban forests can play key roles in mitigate stormwater runoff, improve air quality, reduces noise level, store carbon, etc. The system of green areas in a continuous and dynamic interaction with the built structure in a city. Because of the above, subject of the research is determining the state of greenery in the Banja Luka area and the changes that accompany it and to suggest the planning of green areas and protect them.

Noise pollution, as a major environmental problem, is present in Banja Luka. The measured values exceeded the level of noise allowed, which is a great problem. Evaluation of the noise levels was carried out in the streets in the area with health institutions. Objectives of this research were to evaluate the environmental noise pollution in the City of Banja Luka due to traffic noise and to compare the measured noise levels in the city with legislation and to establish the connection between noise and the number of vehicles. Correlation between the noise level and number of vehicles was positive and significant during the study period (r=0.89). It is confirmed that, with the increase of the number of vehicle, the noise level increases, i.e. the decrease in the number of vehicle decreases the noise level.

Atmospheric pollutants have a negative effect on the plants; they can have direct toxic effects, or indirectly by changing soil pH followed by solubilization of toxic salts of metals. Large number of studies have investigated the possible effects of ambient air pollution on  vegetation and air pollution in stomata number and size and stomatal apparatus. The primary aim of this study was to impact air pollution from the aspect of presence SO2, NOX, CO2, O3 and PM10 on vegetation in the city of Banja Luka and stomatal response to air pollution, through a review of existing research.

Dino Oglic, Thomas Gärtner

We extend the Nystr\"om method for low-rank approximation of positive definite Mercer kernels to approximation of indefinite kernel matrices. Our result is the first derivation of the approach that does not require the positive definiteness of the kernel function. Building on this result, we then devise highly scalable methods for learning in reproducing kernel Kre\u{\i}n spaces. The main motivation for our work comes from problems with structured representations (e.g., graphs, strings, time-series), where it is relatively easy to devise a pairwise (dis)similarity function based on intuition/knowledge of a domain expert. Such pairwise functions are typically not positive definite and it is often well beyond the expertise of practitioners to verify this condition. The proposed large scale approaches for learning in reproducing kernel Kre\u{\i}n spaces provide principled and theoretically well-founded means to tackle this class of problems. The effectiveness of the approaches is evaluated empirically using kernels defined on structured and vectorial data representations.

C. Murguia, I. Shames, Justin Ruths, D. Nešić

As more attention is paid to security in the context of control systems and as attacks occur to real control systems throughout the world, it has become clear that some of the most nefarious attacks are those that evade detection. The term stealthy has come to encompass a variety of techniques that attackers can employ to avoid being detected. In this manuscript, for a class of perturbed linear time-invariant systems, we propose two security metrics to quantify the potential impact that stealthy attacks could have on the system dynamics by tampering with sensor measurements. We provide analysis mathematical tools (in terms of linear matrix inequalities) to quantify these metrics for given system dynamics, control structure, system monitor, and set of sensors being attacked. Then, we provide synthesis tools (in terms of semidefinite programs) to redesign controllers and monitors such that the impact of stealthy attacks is minimized and the required attack-free system performance is guaranteed.

Shatavisha Dasgupta, P. Ewing-Graham, F. V. van Kemenade, Helena C. van Doorn, V. Noordhoek Hegt, S. Koljenović

Differentiated vulvar intraepithelial neoplasia (dVIN) is the precursor lesion of HPV-negative vulvar squamous cell carcinoma (VSCC). The histopathological diagnosis of dVIN can be challenging, as it often resembles vulvar non-neoplastic epithelial disorders (NNED), especially lichen sclerosus (LS). We aimed to establish the most specific and reproducible histological features of dVIN and assessed cytokeratin 13 (CK13) and cytokeratin 17 (CK17) immunohistochemistry as a diagnostic aid. Consecutive cases of dVIN (n = 180) and LS (n = 105) from the period 2010 to 2013 were reviewed using a checklist of histological features. Each feature was recorded as ‘present’ or ‘absent’ and statistical comparison (dVIN vs LS) was made. Interobserver agreement between two pairs of pathologists was assessed for a subset of cases of dVIN (n = 31) and LS and other NNED (n = 23). Immunohistochemistry with CK13, CK17, MIB1 and p53 was performed on dVIN, LS, and other NNED cases. Macronucleoli, features of disturbed maturation and angulated nuclei were significantly more common in dVIN than LS (p < 0.001). We found ‘substantial agreement’ for the diagnosis of dVIN (κ = 0.71). Macronucleoli and deep keratinisation had the highest agreement. In dVIN, the mean percentage of cells staining with CK13 was 15 and with CK17, this was 74. For LS, the mean percentage of cells staining with CK13 was 31, and with CK17, this was 41. By plotting receiver operating characteristic curves (ROC), an area under the curve (AUC) of 0.52 was obtained for CK13, and an AUC of 0.87 was obtained for CK17. The most helpful histological features for diagnosing dVIN were macronucleoli, features of disturbed maturation, and angulated nuclei. Increased CK17 expression may have promise for supporting dVIN diagnosis.

A. Blagojevic, Iskra Stojanova, Marko Subotić, Veljko Radicevic

The main objective of the European policy of rail transport is the development of a single railway area. The opening of the railway sector to market competition impose that railway undertakings behave like any other modern enterprises in other markets and in other industries. It means, they must constantly develop and maintain competitive advantages, and be better than others. In today’s very intense competition conditions, this is the most difficult to achieve. The railway undertakings are challenged to find optimal solutions to operate efficiently and effectively, in order not only to survive on the transport market, but also to develop and maintain a competitive advantage. The paper developed innovative model for the evaluation of efficiency of railway operators for passenger transport assessing the scope of work of railway undertakings that can greatly help to increase the competitive ability of railway undertakings in the single railway market. The developed models allow the integration of indicator groups (resources, operational, financial, quality and safety indicators) into a single assessment of the scope of work of railway undertakings and also allow the provision of information about the corrective actions that can improve the scope of work of the railway undertaking. The proposed model has been tested on actual examples, e.g. railway undertaking Railways of Republic of Srpska. The analysis of the results shows exceptional suitability for use of developed approach for assessing the scope of work of railway undertakings.

Amela Džubur, Delila Lisica, Damir Abdulahović, D. Avdić, Munib Smajović, Maida Mulić

Introduction: The aim of this study was to assess the level of burnout syndrome among primary healthcare professionals in Canton Sarajevo and whether there is a link between the levels of burnout syndrome and sociodemographic parameters. Methods: We included a total of 300 primary healthcare professionals. The burnout syndrome level was measured by Maslach Burnout Inventory, consisting of 22 particles (3 subscales) measuring the level of emotional exhaustion (EE), depersonalization (DP), and personal accomplishment (PA). We analyzed the correlation and difference between the level of burnout and sociodemographic parameters. Results: The study revealed that in Canton Sarajevo 25.3% of healthcare professionals experience a high level of EE, 17.7% experience DP, and 19.0% experience a low level of PA. The subjects under 40 years experienced a higher level of EE than older subjects (p=0.000). There were significant differences in PA subscale between men and women (p=0.033), women having lower level of PA than males. Respondents who worked in shifts and respondents with indefinite period employment experience significantly a high level of EE. Subjects who drink alcohol had a higher level of DP. Conclusion: Healthcare professionals are at increased risk of burnout. Factors which increase the burnout syndrome risk in health professionals in Sarajevo Canton were: age under 40 years old, female, working in shifts and drinking alcohol.

P. Yasaei, Z. Hemmat, C. Foss, Shixuan Li, L. Hong, A. Behranginia, Leily Majidi, R. Klie et al.

Van der Waals interactions in 2D materials have enabled the realization of nanoelectronics with high‐density vertical integration. Yet, poor energy transport through such 2D–2D and 2D–3D interfaces can limit a device's performance due to overheating. One long‐standing question in the field is how different encapsulating layers (e.g., contact metals or gate oxides) contribute to the thermal transport at the interface of 2D materials with their 3D substrates. Here, a novel self‐heating/self‐sensing electrical thermometry platform is developed based on atomically thin, metallic Ti3C2 MXene sheets, which enables experimental investigation of the thermal transport at a Ti3C2/SiO2 interface, with and without an aluminum oxide (AlOx) encapsulating layer. It is found that at room temperature, the thermal boundary conductance (TBC) increases from 10.8 to 19.5 MW m−2 K−1 upon AlOx encapsulation. Boltzmann transport modeling reveals that the TBC can be understood as a series combination of an external resistance between the MXene and the substrate, due to the coupling of low‐frequency flexural acoustic (ZA) phonons to substrate modes, and an internal resistance between ZA and in‐plane phonon modes. It is revealed that internal resistance is a bottle‐neck to heat removal and that encapsulation speeds up the heat transfer into low‐frequency ZA modes and reduces their depopulation, thus increasing the effective TBC.

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