Long-term monitoring of the broad-line region properties in a selected sample of AGN

We present the results of the long-term optical monitoring campaign of active galactic nuclei (AGN) coordinated by the Special Astrophysical Observatory of the Russian Academy of Science. This campaign has produced a remarkable set of optical spectra, since we have monitored for several decades different types of broad-line (type 1) AGN, from a Seyfert 1, double-peaked line, radio loud and radio quiet AGN, to a supermassive binary black hole candidate. Our analysis of the properties of the broad line region (BLR) of these objects is based on the variability of the broad emission lines. We hereby give a comparative review of the variability properties of the broad emission lines and the BLR of seven different type 1 AGNs, emphasizing some important results, such as the variability rate, the BLR geometry, and the presence of the intrinsic Baldwin effect. We are discussing the difference and similarity in the continuum and emission line variability, focusing on what is the impact of our results to the supermassive black hole mass determination from the BLR properties.Comment: Published in Frontiers in Astronomy and Space Scienc

Failure analysis of a special vehicle engine connecting rod

This paper presents failure analysis of the connecting rod used in a 12-cylinder diesel engine set on a special vehicle. The fracture of the connecting rod occurred during the engine test in laboratory conditions. Chemical and metallographic analysis as well as mechanical testing have confirmed that the material properties of the connecting rod met the requirements of standard specification and technical documentation. Linear finite element (FE) analysis was performed to evaluate stress state of the connecting rod under maximum load. The results of FE analysis showed that the position of the fracture is consistent with the zone of highest stress. Fractographic analysis has not been able to reveal the main cause of mechanism of fracture due to substantially damaged fracture surface. Inadequate machining, absence of polishing and highest stress in the region of fracture were identified as the main causes of failure. Finally, the engine had been working at maximum load for a longer period of time that also led to the breakage of the connecting rod.This is the peer reviewed version of the paper: Rakić, S. N.; Bugarić, U.; Radisavljević, I.; Bulatović, Ž. Failure Analysis of a Special Vehicle Engine Connecting Rod. Engineering Failure Analysis 2017, 79, 98–109. [https://doi.org/10.1016/j.engfailanal.2017.04.014

Optimization of Collateral Value Distribution

Loan Loss Provisioning (LLP) is an amount of reserve that banks "put aside" to cover loss in case that loan goes in default, meaning that clients do not repay it. It is a safety buffer for preserving banks liquidity and capital adequacy. On the other hand, the Loan Loss Provisioning is a cost. In the Profit and Lost statement of banks, LLP decreases profit. It is a good tool/mechanism for risk management, but also expensive one, and that is why it is important for banks to optimize it in every possible way. The aim of optimization is to distribute collateral value to the connected loans, in a way to minimize amount of LLP. It can be done easily on a one loan level, but creating a universal algorithm that is applicable to all loans and all collaterals on the Bank portfolio level, is the goal to be achieved

Unaprijeđeno upravljanje momentom visokobrzinskog pogona s asinkronim motorom bez mjerenja brzine

This paper presents improved torque control scheme for a high speed sensorless induction motor drive. The proposed high speed torque control scheme substitutes the flux oriented control by the voltage angle control in the flux weakening regime. This scheme uses maximum of available inverter voltage, alleviates well known problems of current control schemes in conditions with insufficient voltage margin and avoids the influence of estimated speed error to the achieved flux level. The algorithm uses similar slip control as flux oriented control algorithm, but is applied without an outer flux trajectory reference which is typical for the flux weakening, providing a fast and well damped torque response even if error in estimated speed is present. Experiments confirm the effectiveness of proposed torque control algorithm, smooth transition from the flux oriented control in the base speed region to the voltage angle control in the flux weakening, superior dynamic performance of the voltage angle torque control, and its robustness to an estimated rotor speed error.U radu je predstavljena unaprijeđena shema upravljanja za pogon visokobrzinskog asinkronog motora bez mjerenja brzine. Predloženi postupak zamjenjuje vektorsko upravljanje upravljačkom strukturom s upravljanjem kutom napona u slabljenju polja. Predložena shema koristi maksimalni raspoloživi napon invertora, eliminira dobro poznate probleme strujno reguliranih pogona u uvjetima s nedovoljnom rezervom napona i eliminira utjecaj greške u estimaciji brzine na dostignutu razinu toka. Algoritam koristi sličnu kontrolu klizanja kao i vektorsko upravljanje, ali bez tipičnog vanjskog zadavanja toka u slabljenju polja, pružajući brz i dobro prigušen odziv momenta čak i u slučaju greške u estimaciji brzine. Eksperimenti izvedeni na velikoj brzini vrtnje potvrđuju učinkovitost predložene regulacije momenta, gladak prijelaz iz baznog područja brzine u slabljenje polja, vrhunske dinamičke performanse upravljanja kutom napona i robusnost na pogrešku u estimiranoj brzini vrtnje

Effect of temperature on the physical changes and drying kinetics in plum (Prunus domestica L.) Požegača variety

In this study, drying kinetics of autochthonous variety Požegača plum was examined in a laboratory dryer at three temperatures. The whole plum fruits, together with the kernels were subjected to the drying process. The effect of drying has been examined at temperatures of 55, 60 and 75 °C, with a constant air velocity of 1.1 m s-1. The corresponding experimental results were tested using six nonlinear regression models. Coefficient of determination (R2), standard regression error (SSE), model correlation coeficient (Vy), as well as the maximum absolute error (ΔY) showed that the logaritmic model was in good agreement with the experimental data obtained. During drying of plums, the effective diffusivity was found to be between 5.6×10-9 for 55 °C and 8.9×10-9 m2 s-1 at 75 °C, respectively. The physical characteristics of fresh (length 39.64 mm and width 29.15 mm) and dried (length 37.52 mm and width 22.85 mm) plum fruit were determined. Finally, by chemical analysis, the contents of micro- and macro-elements (Fe, Mn, Cu, B and N, F, K, Ca, Mg and S) in the skin and flesh of the dried product, prunes, has been established

Antifungalna aktivnost ekstrakata makrogljiva na fitopatogene sojeve gljiva rodova Fusarium sp. i Alternaria sp.

During the last decades, intensive application of synthetic fungicides in the agricultural crop protection practice caused growing concern for the existence of toxic chemical residues in food as well as in the whole environment. Instead of using synthetic fungicides, it is suggested that crop protection be carried out by using preparations based on compounds of natural origin (secondary metabolites of plants or microorganisms, including macrofungi from Basidiomycota) as biological control agents. The potential of macrofungal species as biocontrol agents was analyzed in this investigation of eight autochthonous species from different locations in Serbia. Both the terricolous species: Coprinus comatus, Coprinellus truncorum, Amanita strobiliformis, Hydnum repandum and the lignicolous species: Flammulina velutipes, Stereum subtomentosum, Trametes versicolor and Bjerkandera adusta were examined, with an aim to detect some novel sources of antifungal agents. This study surveyed antifungal activity of selected macrofungal extracts (MeOH, EtOH and CHCl3) against phytopathogenic Fusarium and Alternaria strains isolated from garlic, soybean and rice: F. proliferatum, F. verticillioides, F. proliferatum, F. graminearum and A. padwickii. Microdilution method in 96 well micro-plates was applied for the estimation of antifungal effects of macrofungi extracts in the range from 24.75 to 198.00 mg/ml and determination of minimal inhibitory (MIC) and minimal fungicidal concentration (MFC). EtOH extract of mychorhizal species H. repandum showed antifungal activity against all analyzed phytopathogenic strains, with the strongest effect on Fusarium strains (MIC 24.75 mg/ml; MFC 24.75 mg/ml). Among others, MeOH extracts of S. subtomentosum and C. micaceus showed similar effects while only B. adusta showed slight effect on Fusarium strains (MIC 24.75-99.00 mg/ml; MFC 24.75-99.00 mg/ml) and none effect on A. padwickii. The obtained results indicate the possibility of using examined extracts as efficient antifungal agents and provide the basis for the new formulations of biocontrol agents against phytopathogenic fungi in the future.Tokom poslednjih decenija intezivna primena sintetičkih fungicida u zaštiti poljoprivrednih useva izaziva sve veću zabrinutost ljudi zbog prisustva toksičnih hemijskih ostataka u prehrambenim proizvodima kao i celoj okolini. Umesto korišćenja sintetičkih fungicida, preporučuje se da se zaštita useva vrši korišćenjem preparata na bazi jedinjenja prirodnog porekla (sekundarni metaboliti biljaka ili mikroorganizama uključujući i makrogljive iz razdela Basidiomycota) kao agense biološke kontrole. U ovom radu istraživan je potencijal agenasa biološke kontrole za osam autohtonih vrsta makrogljiva s različitih lokaliteta u Srbiji. Obe, terikolne vrste: Coprinus comatus, Coprinellus truncorum, Amanita strobiliformis, Hydnum repandum i lignikolne vrste: Flammulina velutipes, Stereum subtomentosum, Trametes versicolor i Bjerkandera adusta su istražene s ciljem da se otkriju neki novi izvori antifungalnih agenasa. U okviru ovog rada istražena je antifungalna aktivnost odabranih ekstrakata makrogljiva (metanolni, etanolni i hloroformski) protiv fitopatogenih sojeva Fusarium i Alternaria izolovanih s belog luka, soje i pirinča: F. proliferatum, F. verticillioides, F. proliferatum, F. graminearum i A. padwickii. Za procenu antifungalnog efekta ekstrakata makrogljiva upotrebljena je mikrodiluciona metoda mikrotitar pločama s 96 velova u opsegu koncentracija od 24,75 do 198,00 mg/ml i determinaciju minimalne inhibitorne (MIC) i minimalne fungicidne koncentracije (MFC). Etanolni ekstrakt mikorizne vrste H. repandum pokazao je atifungalnu aktivnost prema svim analiziranim fitopatogenim sojevima, sa najjačim efektom prema sojevima Fusarium (MIC 24,75 mg/ml; MFC 24,75 mg/ml). Između ostalog, sličan efekat pokazali su i metanolni ekstrakti S. subtomentosum i C. micaceus, dok je samo B. adusta imala blagi efekat na sojeve Fusarium (MIC 24,75-99,00 mg/ml; MFC 24,75-99,00 mg/ml), ali ne i na A. padwickii. Dobijeni rezultati ukazuju na mogućnost korišćenja ispitanih ekstrakata kao veoma efikasnih antifungalnih agenasa i samim tim oni predstavljaju osnovu za nove formulacije biokontrolnih agenasa protiv fitopatogenih gljiva u budućnosti

Research of combustion in older generation spark-ignition engines in the condition of use leaded and unleaded petrol

This paper analyzes the potential problems in the exploitation of the older generation of spark-ignition engines with higher octane number of petrol (unleaded petrol BMB 95) than required (leaded petrol MB 86). Within the experimental tests on two different engines (STEYR-PUCH model 712 and GAZ 41) by applying piezoelectric pressure sensors integrated with the engine spark plugs, acceleration sensors and special electronic block connected with distributor, show that the cumulative first and second theoretical phase of combustion when petrol of higher octane number (BMB 95) is used lasts slightly longer than when the low-octane petrol MB 86 is used. For new petrol (BMB 95) higher optimal angles of pre-ignition have been determined by which better performances of the engine are achieved without a danger of the combustion with detonation (also called knocking)

Research of combustion in older generation spark-ignition engines in the condition of use leaded and unleaded petrol

This paper analyzes the potential problems in the exploitation of the older generation of spark-ignition engines with higher octane number of petrol (unleaded petrol BMB 95) than required (leaded petrol MB 86). Within the experimental tests on two different engines (STEYR-PUCH model 712 and GAZ 41) by applying piezoelectric pressure sensors integrated with the engine spark plugs, acceleration sensors and special electronic block connected with distributor, show that the cumulative first and second theoretical phase of combustion when petrol of higher octane number (BMB 95) is used lasts slightly longer than when the low-octane petrol MB 86 is used. For new petrol (BMB 95) higher optimal angles of pre-ignition have been determined by which better performances of the engine are achieved without a danger of the combustion with detonation (also called knocking)

On some new pre-orders defined by weighted Drazin inverses

In this paper, we investigate new binary relations defined on the set of rectangular complex matrices based on the weighted Drazin inverse and give some characterizations of them. These relations become pre-orders and improve the results found by the authors in Hernandez et al. (2013) as well as extend those known for square matrices. On the other hand, some new weighted partial orders are also defined and characterized. The advantages of these new relations compared to the ones considered in the mentioned paper are also pointed out.N. Thome was partially supported by Ministerio de Economia y Competitividad of Spain (Grant DGI MTM2013-43678-P and Red de Excelencia MTM2015-68805-REDT).Hernández, AE.; Lattanzi, MB.; Thome Coppo, NJ. (2016). On some new pre-orders defined by weighted Drazin inverses. Applied Mathematics and Computation. 282:108-116. https://doi.org/10.1016/j.amc.2016.01.055S10811628