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Selma Čaušević, K. Saxena, M. Warnier, A. Abhyankar, F. Brazier

ABSTRACT Resilience of power systems is highly impacted by factors such as increasing severity and frequency of weather events, but also smart grid advances that introduce major operational changes in power systems. Rapidly adapting to these changing circumstances and harnessing the potential of technological advances is the key to ensuring that power systems stay operational during disturbances, thereby improving resilience. This paper addresses this challenge by presenting an approach for improving resilience through local energy resource sharing across multiple distribution systems. The approach brings together the physical and the ICT layer of power systems through a self-organization approach that automatically alters the physical grid topology and forms local energy groups in order to mitigate the effects of widespread outages. Thereby, supply and demand are locally matched, and demand met is maximized during an outage. The results demonstrate that using the proposed approach, operational resilience of impacted distribution systems is improved.

A. Greljo, Toby Opferkuch, B. A. Stefanek

The mass hierarchy among the three generations of quarks and charged leptons is one of the greatest mysteries in particle physics. In various flavor models, the origin of this phenomenon is attributed to a series of hierarchical spontaneous symmetry breakings, most of which are beyond the reach of particle colliders. We point out that the observation of a multipeaked stochastic gravitational wave signal from a series of cosmological phase transitions could well be a unique probe of the mechanism behind flavor hierarchies. To illustrate this point, we show how near future ground- and space-based gravitational wave observatories could detect up to three peaks in the recently proposed PS^{3} model.

S. Ostojić, V. Štajer, M. Vraneš, J. Ostojić

Abstract A novel creatine blend (creatine nitrate mixed with creatinine, CN‐CRN) has been anecdotally suggested to be superior to traditional creatine formulations for bioavailability and performance. However, does CN‐CRN supremely affects creatine levels in the blood and skeletal muscle of healthy humans remain currently unknown. This randomized, controlled, double‐blind, crossover trial evaluated the acute effects of single‐dose CN‐CRN on serum creatine levels, and 5‐days intervention with CN‐CRN on skeletal muscle creatine and safety biomarkers in healthy men. Ten healthy young men (23.6 ± 2.9 years) were allocated to receive either CN‐CRN (3 grams of creatine nitrate mixed with 3 grams of creatinine), pure creatine nitrate (3 grams, CN), or regular creatine monohydrate (3 grams, CRM) by oral administration. We found that CN‐CRN resulted in a more powerful rise in serum creatine levels comparing to either CN or CRM after a single‐dose intervention, as evaluated with the area under the concentration–time curve calculation (701.1 ± 62.1 (µmol/L) × min versus 622.7 ± 62.9 (µmol/L) × min versus 466.3 ± 47.9 (µmol/L) × min; p < .001). The peak serum creatine levels at 60‐min sampling interval were significantly higher in CN‐CRN group (183.7 ± 15.5 µmol/L), as compared to CN group (163.8 ± 12.9 µmol/L) and CRM group (118.6 ± 12.9 µmol/L) (p < .001). This was accompanied by a significantly superior increase in muscle creatine levels after CN‐CRN administration at 5‐days follow‐up, as compared to CN and CRM, respectively (9.6% versus 8.0% versus 2.1%; p = .01). While 2 out of 10 participants were found to be nonresponsive to CN intervention (20.0%) (e.g., no amplification in muscle creatine levels found at 5‐days follow‐up), and 3 participants out of 10 were nonresponsive in CRM trial (30%), no nonresponders were found after CN‐CRN administration, with individual upswing in total muscle creatine varied in this group from 2.0% (lowest increment) to 16.8% (highest increment). Supplemental CN‐CRN significantly decreased estimated glomerular filtration rate (eGFR) at 5‐days follow‐up, as compared to other interventions (p = .004), with the average reduction was 14.8 ± 7.7% (95% confidence interval; from 9.3 to 20.3). Nevertheless, no single participant experienced a clinically relevant reduction in eGFR (< 60 ml/min/1.73 m2) throughout the course of the trial. Liver enzymes remained in reference ranges throughout the study, with no participant experienced high liver blood tests (e.g., AST > 40 units per L or ALT >56 units per L). Besides, no participant reported any major side effects during the trial, while the odors of CN‐CRN and CN formulations were considered somewhat unpleasant in 8 out of 10 participants (80.0%). Our results suggest that CN‐CRN is a preferred and relatively safe alternative to traditional creatine formulations for improved creatine bioavailability in the blood and skeletal muscle after single‐dose and 5‐days interventions.

I. Tanackov, Feta Sinani, M. Stankovic, V. Bogdanović, Željko Stević, Mladen Vidić, Jelena Mihaljev-Martinov

We will prove that when uniformly distributed random numbers are sorted by value, their successive differences are a exponentially distributed random variable Ex(λ). For a set of n random numbers, the parameters of mathematical expectation and standard deviation is λ =n−1. The theorem was verified on four series of 200 sets of 101 random numbers each. The first series was obtained on the basis of decimals of the constant e=2.718281…, the second on the decimals of the constant π =3.141592…, the third on a Pseudo Random Number generated from Excel function RAND, and the fourth series of True Random Number generated from atmospheric noise. The obtained results confirm the application of the derived theorem in practice.

B. Farrar, L. Ostojić

A prominent vein of comparative cognition research asks which cognitive abilities may be ascribed to different species. Here, we argue that the current structure of comparative cognition makes it near impossible to evaluate the accuracy of many of the claims produced by the field’s empirical research. We base this argument on six observations: i) the field is biased towards confirming more exceptional abilities in animals, ii) a likely high rate of false positive discovery, iii) the persistence of the bias towards more exceptional abilities, even in the presence of strong methodological criticism, iv) the absence of a formal method to assess evidence of absence of a cognitive ability, v) the ambiguity in definitions used to make claims, and vi) the small size of the research field. We then highlight how the widespread methodological and conceptual criticism in the comparative cognition literature does not facilitate scientific progress, rather it can impede it by creating an illusion of scientific rigour. Finally, we call for a reform of our research field that draws on recent developments in related fields and the Open Science movement.

Ingmar Bešić, E. Buza, Razija Turcinhodzic

Team performance depends on both individual and collaborative skills. This dependence creates increasing education and training demand while striving to improve teams’ efficiency. Consequentially, training and education systems emerge with new capabilities that are changing the learning landscape. With increasingly disperse and mobile teams it can be very inefficient and costly to provide training and education in a centralized instructor-led classes’ manner. Remote solutions are able to reach far more potential users at any moment, and tend to be satisfactory and possibly preferred in many different training and education areas. Computer Aided Design (CAD) requires high quality graphics for positive impact and high satisfaction. Software tools used for hands-on CAD training exercises depend on dedicated Graphics Processing Unit (GPU) to deal with complex graphics processing needed to visualize virtual models in real-time. It is challenging for the remote training system to offer this high level of experience to remote users. In this paper, synergy of conventional CAD laboratory workstations into cells is proposed in order to create a cost-effective team training remote system. The system utilizes existing capabilities of dedicated GPUs and custom software modules to capture video, perform hardware HEVC encoding, and stream the video at low bitrates and sub-second latency to remote team members.

N. Rustempašić, Martina Gengo

Introduction: Color Doppler and CT angiography are diagnostic methods commonly used to determine the degree of carotid stenosis. Aim: To evaluate how the degree of carotid stenosis determined by the Color Doppler correlates with the degree of stenosis determined by the CT angiography. Material and Methods: The study was designed as a retrospective study. It included 42 patients with carotid stenosis. From medical records we collected anamnestic data (gender, age and risk factors - hypertension, hyperlipidemia, diabetes, smoking and obesity) and the results regarding the degree of carotid stenosis determined by Color Doppler and CT angiography. Results: Out of the total number of patients (n=42), 73.8% were males and 26.2% were females. Average age of examined patients was 65.24±8.61. Most frequent risk factor of atherosclerosis was hypertension, followed by hyperlipidemia and smoking. NASCET grading distinguishes: first (0-29%), second (30-69%) and third (70-99%) degree of carotid stenosis. According to the Color Doppler evaluation findings, the second degree had 8 patients and 34 patients had the third degree of carotid stenosis. CT angiography have shown that 35 patients had third degree carotid stenosis, while 7 patients had the second degree carotid stenosis. In only one case results of evaluated methods differed regarding assessment of carotid stenosis. We have found that there is a significant positive correlation of the degree of carotid stenosis determined by the Color Doppler with the degree of stenosis determined by CT angiography (p=0.0002). Risk factors of atherosclerosis did not have a significant correlation with the degree of carotid stenosis (p>0.05). Conclusion: The degree of carotid stenosis estimated by the Color Doppler positively correlates with the degree of stenosis estimated by CT angiography.

A. Ktena, G. Panagakis, J. Hivziefendic

The ascending trend in retail electricity prices since the first energy package is often blamed on the market reforms and the cost of a low carbon economy. The present study analyzes EU-28 statistical data on retail prices for the medium households and industries, for the years 2008–2017, a period of economic slowdown. We focus especially on six countries, Austria, Denmark, Germany, Greece, Latvia and Spain and examine retail prices against the degree of renewable energy sources (RES) penetration and the market liberalization in each country. We also examine the cases of three Western Balkan countries that still have a very low degree of liberalization. The increasing percentage of RES in electricity generation, the number of retailers and the market share of the main retailer are analyzed with respect to the retail electricity price for the period studied. In spite of the different specifics of each country's economy, there are certain common trends. The price increase has been found to be the result of levies and taxes, rather than the energy cost, with the burden carried mostly by households. In the cases studied here, the increase correlates with either the increase in RES or increased competition or both depending on the market structures in place during the examined period and the maturity and performance of the measures towards a liberalized electricity market and a low carbon economy.

Jelena Milic, M. Ćurčić, Zvonko Brnjaš, H. Čarapina, J. Randjelovic, K. Krinulović, A. Jovović

Assessing the socio-economic impact of dangerous chemicals, including persistent organic pollutants (POPs) as a specific segment, includes analysis of their impacts on human health, on the environment and on local economic development. Abundant evidence of these effects of dangerous chemicals throughout the world is provided by published research. According to WHO, these chemicals cause around 4.9 million deaths (8.3%) and 86 million Disability-Adjusted Life Years (5.7%) globally; according to very conservative estimates, 20% of cancer deaths are the consequence of the cancerous effects of chemicals in the work place. Their impact on economic development is manifested primarily through reduced productivity of society due to health impairment of both the population and natural resources. Specific research, the results of which are presented in this article, has been focused on the impact of POPs on human health. This impact is presented in very general terms through estimation of the monetized cost effects for treating those diseases and cancers assumed to be caused by POPs in Serbia. The cost estimation based on available data amounts to approximately € 68 million for a 5-year period.

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