Composition and Morphology Investigation of NiCoB Nanoparticles, as-Prepared and Coated by SiO2

NiCoB nanoparticles, as-prepared and coated by SiO2, were synthesized by chemical reduction of metallic salts. The as-prepared samples were additionally annealed at 650 for 1 hour in argon atmos-phere. All samples (the as-prepared and annealed ones) were investigated by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). According to FE-SEM observations each of the investigated samples was composed of nearly spherical nanoparticles with average dimension smaller than 30 nm. Also, tendency of formation of irregular agglomerates was present in both cases of the as-prepared and annealed investigated samples. XRD measurements of as-prepared samples revealed fully amorphous structure. In case of annealed samples, crystallization of different phases was confirmed (as a consequence of heat treatment at 650 C). The existence of these phases was also observed from FE-SEM micrographs as different morphologies present in the samples.(doi: 10.5562/cca2234

THE EFFECT OF PLANT DENSITY ON SOME MORPHOLOGICAL AND PHENOLOGICAL TRAITS OF FIBER FLAX VARIETIES

Postoje pokušaji ponovnog uvođenja predivog lana u poljoprivrednu proizvodnju u nas, te smatramo korisnim ukazati na neka njegova važnija svojstva, U radu se iznose rezultati postignutih morfoloških i fenoloških svojstava predivog lana. Pokusi s predivim lanom izvedeni su tijekom dvije godine (2002-2003) u Maksimiru i Posavskim Bregima. U pokusu je bilo zastupljeno pet sorata i to: četiri češke sorte (Jitka, Texa, Merkur i Bonet) i jedna nizozemska sorta (Viola). Odabrane sorte sijane su u dvije gustoće (2000 i 2500 sjemenki /m2). Na osnovi dobivenih dvogodišnjih istraživanja morfoloških i fenoloških svojstava predivog lana na dvije lokacije utvrđeno je da postoje signifikantne razlike između istraživanih sorata i između gustoća sjetve. Signifikantno najveće prinose sjemena ostvarile su sorte Merkur i Bonet. U rjeđem sklopu ostvarene su više vrijednosti prinosa sjemena, broja tobolaca, broja sjemenki u tobolcu i mase 1000 sjemenki. Sorte Jitka i Texa pripadaju sortama rane vegetacijske skupine sazrijevanja, dok Viola, Merkur i Bonet pripadaju sortama kasne vegetacijske skupine.Since attempts are made to reintroduce fiber flax into agricultural production of Croatia, it seems useful to point to some of its major properties and economic importance. This paper presents the results of the achieved morphological and phenological traits of fiber flax. Cultivar trials with fiber flax were set up in two years (2002-2003) and on two locations (Maksimir and Posavski Bregi). The trials involved five cultivars: four Czech cultivars (Jitka, Texa, Merkur and Bonet) and one Dutch cultivar (Viola). All cultivars were sown in two densities (2000 and 2500 seeds/m2). According to the results of the two-years research into the morphological and phenological traits of fiber flax on two locations, significant differences were established between the cultivars and the planting densities under study. Significantly highest values for seed yield were recorded in cultivars Merkur and Bonet. Higher values of the seed yield, number of capsules, number of seed per capsules and 1000 seed weight were obtained with the lower planting density. Cultivars Jitka and Texa belong to the early vegetation ripening group, while cultivars Viola, Merkur and Bonet belong to the full vegetation ripening group

ESTIMATION OF SOME IMPORTANT AGRONOMIC AND MORPHOLOGICAL TRAITS OF FIBER FLAX VARIETIES IN DIFFERENT PLANT DENSITIES

Prije nekoliko godina započeo je ponovni uzgoj predivog lana na području sjeverozapadne Hrvatske s krajnjom svrhom očuvanja kulturne baštine. S tim u vezi istraživana je mogućnost introdukcije stranih kultivara predivog lana u nizinsko kontinentalno područje RH. Pokusi su postavljeni tijekom dvije godine (2002-2003) na dvije lokacije (Maksimir i Posavski Bregi). U pokusu je bilo zastupljeno pet sorata i to: četiri češke sorte (Jitka, Texa, Merkur i Bonet) i jedna nizozemska sorta (Viola). Sve sorte sijane su u dvije gustoće (2000 i 2500 klijavih sjemenki /m2). Prema dobivenim dvogodišnjim istraživanjima agronomskih i morfoloških svojstava predivog lana na dvije lokacije utvrđeno je da postoje signifikantne razlike između istraživanih sorata i između gustoća sjetve. Interakcija između ova dva faktora nije bila signifikantna niti za jedno svojstvo. Signifikantno najveće vrijednosti za većinu agronomskih i morfoloških svojstava imala je sorta Viola. U rjeđem sklopu ostvarene su više vrijednosti istraživanih svojstava.With the aim to preserve the cultural heritage, fiber flax culture was resumed in northwestern Croatia a few years ago. Possibilities of introducing foreign fiber flax cultivars in the lowland continental part of Croatia were investigated for this purpose. Cultivar trials were set up in two years (2002-2003) and on two locations (Maksimir and Posavski Bregi). The trials involved five cultivars: four Czech cultivars (Jitka, Texa, Merkur and Bonet) and one Dutch cultivar (Viola). All cultivars were sown in two densities (2000 and 2500 seeds/m2). According to the results of the two-years research into the agronomic and morphological traits of fiber flax on two locations, significant differences were established between the cultivars and the planting densities under study. Interaction between these two factors was not significant for any trait. Significantly highest values for agronomic and morphological traits were recorded in the cultivar Viola. Higher values of the traits studied were obtained with the lower planting density

Microstructural Features of Magnetic NiCoB Nanoparticles Addition to MgB2 Precursor Powders

Magnesium diboride (MgB2) is a superconductor characterized by interesting properties like rather high superconducting transition temperature Tc = 39 K, long coherence length and low anisotropy. In addition, it has a very simple crystal structure and low density. Those properties make the MgB2 an ideal candidate for a wide range of applications. To improve the electromagnetic properties of MgB2, magnetic nickel-cobalt-boron (NiCoB) nanoparticles (mean grain size 17 ± 3 nm) were added to Mg and B precursor powders and sintered at 650 °C, i.e. the temperature of MgB2 superconductor formation. The nearly spherical NiCoB nanoparticles, as-prepared by the chemical reduction of metallic salts, were amorphous according to previous study. The resulting MgB2 sample, formed after the sintering at 650 °C, was subjected to detailed microstructural analysis which included the application of various experimental methods: XRD, FE-SEM, EDS, elemental mapping, TEM and SAED. The methods confirmed the formation of new crystal CoNi phase (due to heat treatment at 650C), consisting of spherical nanoparticles (~ 6 nm) with tendency to spherical agglomerates formation. Those nanosized magnetic particles (characterized by the single domain magnetic structure and blocking temperature TB below room temperature), located at MgB2 grain boundaries, could serve as effective magnetic pinning centers in MgB2, thus improving its electromagnetic properties. This work is licensed under a Creative Commons Attribution 4.0 International License

PRODUCTION VALUES OF INVESTIGATED SUGAR BEET HYBRIDS

Tijekom 2003.-2005. godine obavljena je evaluacija proizvodnih vrijednosti 42 eksperimentalna i priznata hibrida šećerne repe na lokaciji Zagreb. U pokuse su bili uključeni hibridi šest selekcijskih kuća koje plasiraju sjeme šećerne repe u R. Hrvatskoj. Dobiveni rezultati istraživanja su pokazali da između istraživanih hibrida šećerne repe postoji značajna razlika u prinosu i kvaliteti korijena. Međutim, veliki broj hibrida dao je po vrijednosti isti rezultat, tj. razlika koja među njima postoji je unutar statistčki dopuštenog odstupanja. Po visokom prinosu šećera istakli su se hibridi Georgina i Buda u 2003., Sofarizo i Takt u 2004. te Merak, Impact i Europa u 2005. godini. Po prinosu korijena najrodniji hibridi bili su Dioneta, Buda i Georgina u 2003., Sofarizo, Takt, HI 0191 i Dorotea u 2004. te Impact i SES 2371 u 2005. godini. Najveći sadržaj šećera u korijenu imali su hibridi Zitai Evelina u 2003., Cyntia, Diamant i Belinda u 2004. te Merak, Belinda i Cyntia u 2005. godini.Production values of 43 experimental and recognized sugar beet hybrids were conducted on the Zagreb location in the period 2003-2005. The trials included hybrids from six breeding institutions that sell sugar beet seed in the Republic of Croatia. Research results have revealed significant differences in yields and root quality among inve- stigated sugar beet hybrids. However, the results of a large number of hybrids were equal in value; namely, the dif- ference between them was within the statistically allowable deviation. The hybrids KW 0148 HR and Buda in 2003, Sofarizo and Takt were distinguished by high sugar yields in 2004, whereas Merak, Impact and Europa in 2005. The highest root yields were recorded for hybrids Dioneta, Buda and KW 0148 HR in 2003, Sofarizo, Takt, HI 0191 and Dorotea in 2004, Impact and SES 2371 in 2005. The highest root sugar contents were determined in hybrids Zita and Evelina in 2003, Cyntia, Diamant and Belinda in 2004, and Merak, Belinda and Cyntia in 2005