The aim of this paper is to present and discuss the influence of distributed generation on power quality. Nowadays, interest in power quality has increased since it has become a very important issue in power system delivery. One of the major problems of ensuring a certain level of power quality are harmonics. The aim of this project is to investigate an impact of photovoltaic (PV) on harmonic voltage distortion (HD) in real MV distribution network. Different scenarios will be implemented where solar power plant is going to be modelled with high variability of load and generation to see their effects on the systems power quality (PQ). Those scenarios are when PV is disconnected from the grid and PVs are connected with 2 different powers. Results presented below showed that PV improves power quality of the system, because their inverters are source of harmonics and they increase HD. However, that impact is not very significant and harmonic limits are not violated. A load flow analysis is done for the model of test system 110/35/10kV in which a distributed generator is added, that is on-grid or off-grid. The network modelling and simulation is done in DIgSILENT PowerFactory software.
Telekia speciosa (Schreb.) Baumg., Asteraceae, is widespread in Eastern and Central Europe and the Balkan Peninsula. Previous phytochemical investigations have revealed T. speciosa as a rich source of sesquiterpene lactone -isoalantolactone, especially in its underground parts. The aim of the present study was to analyze the essential oils from aerial and underground parts of T. speciosa and investigate their antimicrobial activity. Chemical composition of essential oils was determined by GC-FID/MS method leading to the identification of 67 compounds in total, with 15.77 % oxygenated monoterpenes, 7.77 % sesquiterpene hydrocarbons, 49.14 % oxygenated sesquiterpenes, and 12.37 % other compounds from aerial parts, and 3.80 % oxygenated monoterpenes, 3.13 % sesquiterpene hydrocarbons, 90.33 % oxygenated sesquiterpenes from underground parts essential oil. The main components from aerial parts were (E)-nerolidol (11.54 %) and caryophyllene oxide (10.54 %), while isoalantolactone was the predominant component from essential oil underground parts (83.41 %). The minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration of the essential oils were evaluated against six strains of bacteria and two strains of fungus using in vitro microdilution method. Both oils presented antimicrobial properties against pathogens Staphylococcus aureus, Bacilus cereus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. Inhibition of growth of tested microorganisms by T. speciosa underground parts essential oil was achieved with MICs ranging from 1.0 to 11.0 mg mL -1 , while MICs of aerial parts essential oil varied from 4.0 to 30.0 mg mL -1 . The obtained results contribute to the knowledge of antimicrobial properties of T. speciosa, which support traditional uses underground parts of the plant.
For validation and demonstration of high accuracy ranging and positioning algorithms and systems, a wideband radio signal generation and acquisition testbed, tightly synchronized in time and frequency, is needed. The development of such a testbed requires solutions to several challenges. Tight time and frequency synchronization, derived from a centrally distributed time-frequency reference signal, needs to be maintained in the hardware of the transmitter and receiver nodes, and wideband signal acquisition requires sustainable data throughput between the receiver and host PC as well as data storage at GB level. This article presents a testbed for wideband radio signal acquisition, for validation and demonstration of high accuracy ranging and positioning. It consists of multiple Ettus X310 universal software radio peripherals (USRPs) and supports high accuracy (<100 ps) time-deterministic, sustainable signal transmission and acquisition, with a bandwidth up to 320 MHz (in dual channel mode) and frequencies up to 6 GHz. Generation and processing of wideband arbitrary signal waveforms is done offline. To realize these features, radio frequency on chip (RFNoC) compatible HDL units were developed for integration in the X310 SDR platform. Wideband transmission and signal acquisition at a lower duty cycle is applied to reduce the data offloading throughput to the host’s personal computer (PC). Benchmarking of the platform was performed to demonstrate sustainable long duration dual channel acquisition. Indoor range measurements with the synchronous operation of the testbed show a decimeter-level accuracy.
The choice of the appropriate variety of fruit is one of the most important factors in establishing new orchards. It is necessary to choose the variety that will give the best results in meeting the investment goals. This paper offered an innovative decision support model for plum variety selection, based on expert decision making and fuzzy logic. The fuzzy MARCOS (Measurement Alternatives and Ranking according to COmpromise Solution) method was used. The research was conducted with the aim of improving plum production in Bosnia and Herzegovina (BiH). To achieve this, the knowledge of experts from the Republic of Serbia was used, because this country is currently the third in the world in plum production and have branded many plum varieties. The results obtained using this model showed that two plum varieties stand out - Cacanska rodna and Stanley. These results were also confirmed by the performed sensitivity analysis. The worst results were obtained by the Sumadijka variety. These results will help in the selection of plum varieties when establishing new orchards in BiH to achieve the best results in Bosnian plum production.
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