Uticaj reversne struje na nasipnu masu pri elektrolitičkom taloženju bakarnog praha

The possibility of depositing copper powders with different apparent density by changing the shape of reversing current wave is shown. The morphology and crystallinity of powder particles can be varied considerably by changing shape of the reversing current wave and, hence, the apparent density of powders. The relation of apparent density with particle morphology and structure was illustrated.U radu je pokazana mogućnost dobijanja bakarnih prahova različitih nasipnih masa promenom oblika talasa reversne struje. Uspostavljena je zadovoljavajuća veza između morfologije i strukture čestica praha bakra i nasipne mase praha

Observations of transits of the southern exoplanets WASP 4b and WASP 46b by using a 40 cm telescope

Abstract. We present photometric observations of transits of the southern exoplanets WASP 4b and WASP 46b using a 40 cm telescope. The obtained values of the orbital inclination, relative stellar radius and relative planet radius are well within the ranges of the previous solutions of the targets. The only exception is the bigger planet radius of WASP 4b that was necessary to reproduce the deeper transit observed by the TriG filter. Our data have a good time resolution and may be used for refinement of the ephemerides of WASP 4b and WASP 46b. The presented results confirmed that small telescopes can be used successfully for the study of exoplanets orbiting stars brighter than 13 mag

Tretiranje semena suncokreta (Helianthus annuus L.) i efekti primene insekticida

Yield performance is an important target in sunflower hybrid breeding. This property, in addition to yield stability, is crucial for producers and it depends on many factors. One of these factors is plant number per area unit. This property is greatly influenced by polyphagous insects, either those residing in the soil (wireworms) or those that attack young leaves (aphids, crickets, etc.). These damages decrease crop stand and yield performance. Because of that, systemic insecticides are often applied in seed treatment. The treated seed is more expensive, but a reduced number of treatments during growing season, better plant stand and improved yield performance compensate for the higher price.Za oplemenjivače je visina prinosa jedna od najvažnijih osobina prilikom stvaranja novih hibrida suncokreta. Ova osobina i stabilnost prinosa hibrida su od najvećeg interesa i za proizvođača. S obzirom da je to složeno svojstvo, njega uslovljava veliki broj činilaca. Jedan od tih činilaca je i broj biljaka po jedinici površine. Na ovu osobinu prvenstveno utiču polifagni insekti, koji mogu biti štetočine u zemljištu (žičnjaci) ili razni insekti (vaši, popac i sl.) koji nanose štete na mladom lišću. Nastale štete direktno utiču na smanjenje sklopa, a indirektno i na smanjenje prinosa po jedinici površine. Zbog toga je primena insekticida, posebno sistemičnih, prilikom tretiranja semena suncokreta sve više prisutna i kod nas. Ovakvo seme ima višu cenu, ali se uložena sredstva vraćaju kroz smanjenje tretiranja u vegetaciji, postizanje boljeg i ujednačenijeg sklopa, a samim tim i većeg prinosa

The rise and fall of the king : the correlation between FO Aquarii's low states and the White Dwarf's Spindown

The intermediate polar FO Aquarii experienced its first-reported low-accretion states in 2016, 2017, and 2018. We establish that these low states occurred shortly after the system's white dwarf (WD) began spinning down, after having spent a quarter-century spinning up. FO Aquarii is the only intermediate polar whose period derivative has undergone a sign change, and it has now done so twice. By combining our spin-pulse timings with previous data, we determine that the WD's spin period has varied quasi-sinusoidally since the system's discovery, and an extrapolation predicts that the white dwarf was spinning down during newly discovered low states in photographic plates from 1964, 1965, and 1974. Thus, FO Aquarii's low states appear to occur exclusively during epochs of spindown. Additionally, our time-series photometry of the 2016-18 low states reveals that the mode of accretion is extremely sensitive to the accretion rate; when the system is fainter than V~14.0, the accretion onto the WD is largely stream-fed, but when it is brighter, it is almost exclusively disk-fed. The system's grazing eclipse remained detectable throughout all observations, confirming the uninterrupted presence of a disk-like structure, regardless of the accretion state. Our observations are consistent with theoretical predictions that during the low states, the accretion disk dissipates into a ring of diamagnetic blobs. Finally, a new XMM-Newton observation from 2017 indicates that the system's anomalously soft X-ray spectrum and diminished X-ray luminosity in the wake of the 2016 low state appear to be long-lasting changes compared to pre-2016 observations.peer-reviewe

Observations and modeling of the transiting exoplanets XO-2b, HAT-P-18b, and WASP-80b

We present photometric observations and transit solutions of the exoplanets XO-2b, HAT-P-18b and WASP 80b. Our solution of the XO-2b transit gave system parameters whose values are close to those of the previous studies. The solutions of the new transits of HAT-P-18b and WASP 80b differ from the previous ones by bigger stellar and planet radii. We obtained new values of the target initial epochs corresponding to slightly different periods. Our investigation reaffirmed that small telescopes can be used successfully for the study of exoplanets orbiting stars brighter than 13 mag

A Generalized Net Model of the Prostate Gland’s Functioning

Over the last 20 years, many Generalized Net (GN) models of the ways of functioning of the different systems and organs in the human body and models related to the description of biomedical processes in living organisms have been constructed. In this paper, a GN model of the prostate gland’s functioning was developed, as a continuation of the previous research. The model provides the possibility to trace the logical relations of the interactions of the prostate gland and various individual organs in the human body. The model shows the possibility for the existence of currently unknown feedback loops