OPTIMAL BATTERY STORAGE LOCATION AND CONTROL IN DISTRIBUTION NETWORK

The paper discusses the problem of the energy losses reduction in electrical networks using a battery energy storage system. One of the main research interests is to define the optimal battery location and control, for the given battery characteristics (battery size, maximum charge / discharge power, discharge depth, etc.), network configuration, network load, and daily load diagram. Battery management involves determining the state of the battery over one period (whether charging or discharging) and with what power it operates. Optimization techniques were used, which were applied to the model described in the paper. The model consists of a fitness function and a constraint. The fitness function is the dependence of the power losses in the network on the current battery power, and it is suggested that the function be fit by a n - order power function. The constraints apply to the very characteristics of the battery for storing electricity. At any time interval, the maximum power that the battery can receive or inject must be met. At any time, the stored energy in the battery must not exceed certain limits. The power of losses in the network is represented as the power of injection into the nodes of the network. The optimization problem was successfully solved by applying a genetic algorithm (GA), when determining optimal battery management. Finally, the optimal battery management algorithm is implemented on the test network. The results of the simulations are presented and discussed

BLASTOCYSTIS HOMINIS: A MYSTERIOUS AND COMMONLY DISREGARDED PARASITE

Blastocystis hominis (B. hominis) is an anaerobic, single-cell protozoan, commonly present in human and animal stool samples. It can be found in healthy people as well and it still has not been elucidated whether it is a commensal organism or a pathogen. Blastocystosis is a disease caused by the protozoan in humans. The prevalence of the parasitosis varies both between the countries, and between certain population groups within individual countries. Due to poor hygienic conditions, common exposure to animals and intake of contaminated water and food, people in the developing countries have got a higher prevalence of blastocystosis, but economically developed countries have not been spared either. The taxonomy of B. hominis is still a matter of debates. For the reasons of genetic diversity, it has been suggested that the name B. hominis should be replaced with „Blastocystis species‟. Seventeen subtypes of the species have been so far identified, and a definitive characterization of Blastocystis spp. is possible at the molecular level only. The parasite is transferred by the fecal-oral route. A variety of hosts have been identified, and animal-to-human and vice versa transfers have been documented. The most common manifestations of the infection with the organism are diarrhea, abdominal pain, nausea, and bloating. This infection has also been associated with the irritable bowel syndrome (IBS), non-specific colitis, chronic inflammatory bowel disease (CIBD), and urticaria. The diagnosis can be made using the methods of conventional microscopy (CVM), phase-contrast and electron microscopy, cultivation, serodiagnosis, and by using molecular methods. The infection caused by the parasite does not always require treatment. In symptomatic patients, the first line medical treatment is metronidazole. Further studies are required to resolve all dilemmas regarding the parasite

Synthesis and Characterization of Dispersion Reinforced Sintered System Based on Ultra Fine and Nanocomposite Cu-Al2O3 Powders

Characterization of the obtained powder indicates a possibility of the synthesis of nanocomposite Cu-Al2O3 system by the thermochemical procedure, starting from water solutions Cu(NO3)2 and Al(NO3)3. AEM analysis indicates the presence of individual particles of 20-50 nm size. The shape of particles is irregular, with the presence of individual particles of nodular shape. The surface morphology is rough. Apart from that, the presence of an agglomerate with the magnitude of >100nm and of a sponge shape is noticeable. The obtained nanocomposite powders, with the structure basically preserved together with the final product, provided a significant reinforcement effect in the obtained sintered system. This is a consequence of the homogenous distribution of the elements in the structure, accomplished during the synthesis of powder and presence of the third phase which causes stabilization of dislocation substructure and achieves the relevant reinforcing effect. The analysis of the mechanical and electric properties of the sintered Cu-Al2O3 systems based on powders obtained by the thermochemical method shows that in the system with 3wt.%Al2O3, sintered at 900ºC, structural stabilisation occurs only after 30 minutes with considerable reinforcement effects. Since in other systems, the structural stabilisation process was not completed even after 120 minutes, the system with 3wt.% of dispersoids sintered at 900ºC for 30 minutes seems to be the optimum solution for the production of dispersively reinforced Cu-Al2O3 systems. This statement is confirmed by the corresponding analysis of the microstructure. In accordance with the previous statements, the EDS analysis of the sintered systems surface as well as FIB analysis show a homogenous distribution of elements, i.e. present phases. FIB analysis also indicates the size of microstructural constituents within the range of 50-250nm. TEM analysis of the sintered systems reveals the presence of copper crystals of 100 nm in size exposed to twinning, thus pointing to stabilization of the dislocation substructure. SADP of the examined nanocomposite Cu–Al2O3 sintered system shows spots and rings, where spots refer to the individual crystals of copper, and sharp circles (rings) originate from nanocrystals of alumina dispersed in the copper matrix. HRTEM analysis indicates the changes in the lattice parameter, which leads to the conclusion that the eutectic reaction occurred and the third, CuxAlyOz phase was formed on the grain boundary, which will be the subject of future studies based on a more precise approach to physical chemistry of system surfaces and of thermodynamic examinations of the influences of finely dispersed Al2O3 on the formation of the third phase and the increase in the system surface energy. In the end, all the above-mentioned examinations show that the reinforcement of Cu-Al2O3 system occurs via two mechanisms, which are: dispersion and reinforcement mechanism due to the homogenous dispersion of fine particles of Al2O3 in the matrix, and the mechanism of grain boundary reinforcement due to the appearance of the third phase

Canine Dirofilaria Infections in Two Uninvestigated Areas of Serbia: Epidemiological and Genetic Aspects

In 2009 canine filarial infections were investigated in two northern areas of Serbia (Pancevo and Veliko Gradiste), applying morphometry, biochemical staining, and immunological kit to detect Dirofilaria immitis antigens, and two home-made ELISAs to detect antibodies to D. repens and D. immitis somatic/metabolic polyproteins. Moreover, molecular tools were applied to analyze the phylogenetic relationships of the isolates. The microfilariae detected in 21/122 dogs (17.2%) were identified as D. repens (n = 21) and D. immitis (n = 2). D. immitis antigens were found in another 13 animals with occult infection. All of the 15 heartworm-positive dogs also had antibodies to this parasite, which were detected in another 13 subjects, indicating an overall D. immitis seroprevalence rate of 22.9%. Serology for D. repens revealed evidence of antibodies in 42.6% of the dogs, but was negative for 4 microfilaremic dogs. As for the two different areas, the prevalence of microfilariae and/or D. immitis antigens, mainly due to D. repens microfilaremic animals, was not significantly higher in Veliko Gradiste (33.3%) than in Pancevo (22%). However, serology showed a different epidemiological picture. Heartworm infection occurred more often in both areas, and antibodies to dirofilarial nematodes were detected in 72.9% of dogs living in Pancevo, a rate higher than in those living in Veliko Gradiste (57.1%). No risk factors for infection were found, confirming the uselessness of prophylactic drugs against D. repens, and suggesting the presence in these areas of sunrise- or sunset-biting mosquitoes as important vectors. The results indicate the need for both appropriate entomological studies and further research on the intra-species variability shown by D. repens

Subconjunctival Infection due to Dirofilaria Repens - Case Report

Summary The aim of the survey was to present the clinical course and surgical treatment of the first case of human ocular dirofilariosis on the territory of the city of Niš, in the southeast Serbia. Male patient, 57 years old, visited an ophthalmologist because of extreme swelling and redness of the eyelids of the right eye, scratches and pain in his right eye. On standard examination on biomicroscope, temporally 3 mm from the limbus, intrapalpebrally, a mobile parasite was observed in the subconjunctival space. Complete extraction of the living parasites, 13 cm long, was performed. A sample of the nematode based on morphological and morphometric characteristics was identified as Dirofilaria repens-like. The diagnosis was confirmed with molecular methods. For ocular dirofilariosis, surgical methods and complete extraction of the parasite are the only ways to achieve complete recovery

Analysis of the process crystallization of continuous cast special brass alloys with the acoustic emission method

Analyses of possibilities of monitoring the crystallization process of continuously cast special brass alloys with acoustic emission and for establishing a correlation between the microstructure and the recorded acoustic emission signals. With appropriate selection of parameters for gravitational casting process, continuous casting was performed and samples with a macrostructure typical of continuous casting were obtained. A laboratory plant for the simulation of the continuous casting and for the analysis of the crystallization process with acoustic emission was designed. Different energy levels in samples with different macrostructure, as well as in the defective and non-defective samples, were observed. Two types of sources of signals were defined: the signal during solidification of correct crystallization and macrostructure of continuous casting and acoustic emission signal during solidification of samples in with flaws. To check the obtained results, after completion of the crystallization process, the samples were submitted to external with mechanical loading. The acoustic activity by loading is in accordance with the results of on-line monitoring of the crystallization process with acoustic emission. The results obtained show that it is possible to use the acoustic emission for monitoring the crystallization process by continuous and gravitational casting

Prediction of thermophysical and transport properties of ternary organic non-electrolyte systems including water by polynomials

The description and prediction of the thermophysical and transport properties of ternary organic non-electrolyte systems including water by the polynomial equations are reviewed. Empirical equations of Radojković et al. (also known as Redlich-Kister), Kohler, Jacob-Fitzner, Colinet, Tsao-Smith, Toop, Scatchard et al. and Rastogi et al. are compared with experimental data of available papers appeared in well know international journals (Fluid Phase Equilibria, Journal of Chemical and Engineering Data, Journal of Chemical Thermodynamics, Journal of Solution Chemistry, Journal of the Serbian Chemical Society, The Canadian Journal of Chemical Engineering, Journal of Molecular Liquids, Thermochimica Acta, etc.). The applicability of empirical models to estimate excess molar volumes, VE, excess viscosities, ηE, excess free energies of activation of a viscous flow

Red foxes (Vulpes vulpes) as reservoirs of respiratory capillariosis in Serbia

Introduction: The aim of the study was to determine the prevalence of respiratory capillariosis in red foxes (Vulpes vulpes) in some regions of Serbia. Material and Methods: The study was conducted on 102 foxes in six epizootiological regions of Serbia, during the hunting season between 2008 and 2012. Results: The presence of respiratory capillariosis in all tested epizootiological regions was confirmed. The E. aerophilus nematode was detected with overall prevalence of 49.02%. The diagnosis of E. aerophilus infection was confirmed by the determination of morphological characteristics of adult parasites found at necropsy and the trichurid egg types collected from the bronchial lavage and the content of the intestine. Conclusion: The presented results contribute to better understanding of the epidemiology of this nematodosis in Serbia. However, the high prevalence of capillaries in tested foxes, demonstrated in all explored areas, might suggest that foxes from other regions in Serbia may also be infected. The fact that domestic carnivores and humans can also be infected enhances the importance of the overall epidemiological status. To establish the relevant prevalence of respiratory capillariosis, further investigations and continous monitoring of parasitic fauna of carnivores are needed in the whole country

Consensus statement on the epidemiological situation and expected frequency of canine vector-borne diseases in Serbia

The current issue of Veterinarski Glasnik (Vol 74, No 2) is dedicated to canine vectorborne pathogens (VBP) and vector-borne diseases (VBD) in Serbia. All published reviews and original papers indicate the amount of research done in Serbia and the amount of collected and analysed data is high for the majority of topics, inviting us to summarise all the findings in a consensus statement that we hope will be of importance for practitioners who are in constant contact with dogs in Serbia and for researchers who should continue to develop this field of investigation

Multiformni glioblastom lokaliziran u motornom korteksu: specifičnosti u odnosu na gliome niskog stupnja iste lokalizacije - analiza serije od šezdeset bolesnika

The verified presence of a glioblastoma multiforme (GBM ) tumor in the motor area of the brain, in a patient lacking preoperative neurological deficit, offers no certainty that the tumor can be radically removed without the possibility of causing postoperative motor deficit. We present a series of 60 patients hospitalized at the Clinical Department of Neurosurgery, Clinical Center of Serbia in Belgrade between October 2011 and February 2015, harboring tumors located within and in the vicinity of the motor zone of the brain. By using Karnofsky‘s index (KI), the pre- and postoperative conditions of the patients were evaluated. Regarding electrical stimulation of the motor cortex, significantly lower values of the electrical current intensity, frequency, and pulse wave duration (p<0.01) were needed for triggering motor response in case of GBM tumor compared to a slowly growing tumor (low-grade). Patients with low-grade gliomas (LGG) had statistically significantly higher KI values pre- and postoperatively than patients with GBM (p<0.01). Using electrical stimulation of the cortex, a higher grade of resection of LGG could be achieved as compared with the group presenting with GBM (c2=5.281; df=1; p<0.05). Our findings and review of the results reported by other authors underline the necessity of routine application of electrical stimulation of the cerebral cortex in order to identify the primary motor field (M1).Jasna prezentacija tumora mozga u području motorne zone kod bolesnika koji prijeoperacijski nisu imali slabost ekstremiteta nije jamstvo da se on može radikalno odstraniti bez poslijeoperacijskog neurološkog deficita. Prikazujemo niz od 60 ispitanika sa supratentorijalnim tumorima lokaliziranim u i oko motorne zone mozga, koji su hospitalizirani na Institutu za neurokirurgiju KCS u Beogradu u razdoblju od listopada 2011. do veljače 2015. godine. Procjena prije- i poslijeoperacijskog stanja bolesnika je vrednovana ljestvicom Karnofski indeksa (KI). Iz serije su isključeni bolesnici s recidivom tumora i bolesnici čiji je KI kod prijma bio manji od 70. Tijekom procedure elektrostimulacije motornog korteksa potrebne su značajno manje vrijednosti jačine struje, frekvencije i pulsnog vala (p<0,01) za izazivanje motornog odgovora u slučaju postojanja tipa tumora multiformnog glioblastoma (glioblastoma multiforme, GBM ) u odnosu na spororastuće gliome (niskog stupnja) mozga. Nađena je statistički značajna razlika u prije- i poslijeoperacijskim vrijednostima KI (F=48,856; df=1; p<0,01; Eta2=0,457), naime, bolesnici s gliomima niskog stupnja imali su statistički značajno veću vrijednost KI prije- i poslijeoperacijski u odnosu na vrijednosti KI kod skupine bolesnika s GBM (p<0,01). Uporabom elektrostimulacije korteksa postignut je veći stupanj radikalnosti kirurške resekcije glioma niskog stupnja u odnosu na skupinu bolesnika s GBM (c2=5,281; df=1; p<0,05). Kirurgija tumora lokaliziranih u motornom korteksu predstavlja izazov zbog pratećeg rizika od de novo nastanka motornog deficita. Naši rezultati kao i rezultati drugih autora pokazuju neophodnost rutinske primjene direktne elektrostimulacije moždane kore radi identifikacije primarnog motornog polja (M1)