Note on the Preparation of Some Thiobarbiturates

It has been shown that barbituric acid derivatives can be prepared in good yield by gradually adding sodium methoxide as condensation catalyst to a cyanoacetic or malonic ester reacting with urea or its derivatives. The principle of the gradual addition of sodium methoxide as condensing agent has now been extended to condensations of some substituted cyanoacetic and malonic esters with thiourea

Preparation of Some lmino- and Cyano-imino-substituted Barbiturates

A number of imino- and cyano-iminobarbituric acid derivatives has been prepared in good yield by gradually adding sodium methoxide - as condensation catalyst - to some substituted cyanoacetic and malonic esters reacting with urea, dicyandiamide and guanidine

Quality of silage of mixed sunchoke and lucerne forage

The paper presents the chemical composition, nutritional and usable value of sunchoke (Helianthus tuberosus L.) and the possibility of using it for animal nutrition in fresh and canned form. Tests show that sunchoke cut in mid-June contains about 9.43% of crude protein, 2.49% of crude fat, 19.93% of crude cellulose, 50.50% of NFE (nitrogen-free extractives) and 17.65% of ash in the dry matter. Although lucerne biomass had a more favorable chemical composition (18.13% crude protein, 6.72% crude fat, 25.24% crude cellulose, 39.35% BEM and 10.56% ash), the benefits of sunchoke are in the more successful growing in less favorable natural, primarily soil conditions, the more suitable it is for ensiling and the longer it stays on one planted plot. Since it is predominantly an energy (carbohydrate) nutrient, the possibility of ensiling the green biomass of sunchoke in a mixture with 25, 50 and 75% fresh lucerne (25% dry matter) was investigated. The obtained results show that with the increase of lucerne participation, the nutritional value of silage increases, but the quality decreases. In addition to its role in conventional feed production, sunchoke can be an important plant in the system of organic production, production for industrial processing and for extensive cultivation in hunting grounds

Synthesis of Homogeneous Manganese-Doped Titanium Oxide Nanotubes from Titanate Precursors

We report a novel synthesis route of homogeneously manganese-doped titanium dioxide nanotubes in a broad concentration range. The scroll-type trititanate (H(2)Ti(3)O(7)) nanotubes prepared by hydrothermal synthesis were used as precursors. Mn2+ ions were introduced by an ion exchange method resulting Mn(x)H(2-x)Ti(3)O(7). In a subsequent heat-treatment they were transformed into Mn(y)Ti(1-y)O(2) where y=x/(3+x). The state and the local environment of the Mn2+ ions in the precursor and final products were studied by Electron Spin Resonance (ESR) technique. It was found that the Mn2+ ions occupy two positions: the first having an almost perfect cubic symmetry while the other is in a strongly distorted octahedral site. The ratio of the two Mn2+ sites is independent of the doping level and amounts to 15:85 in Mn(x)H(2-x)Ti(3)O(7) and to 5:95 in Mn(y)Ti(1-y)O(2). SQUID magnetometry does not show long-range magnetic order in the homogeneously Mn2+-doped nanotubes.Comment: 7 pages, 6 figure

Site-selective quantum correlations revealed by magnetic anisotropy in the tetramer system SeCuO3

We present the investigation of a monoclinic compound SeCuO3 using x-ray powder diffraction, magnetization, torque and electron-spin-resonance (ESR). Structurally based analysis suggests that SeCuO3 can be considered as a 3D network of tetramers. The values of intra-tetramer exchange interactions are extracted from the temperature dependence of the susceptibility and amount to ~200 K. The inter-tetramer coupling leads to the development of long-range antiferromagnetic order at TN = 8 K. An unusual temperature dependence of the effective g-tensors is observed, accompanied with a rotation of macroscopic magnetic axes. We explain this unique observation as due to site-selective quantum correlations

Electrodeposition and electroless deposition of metallic powders: A comparison

Electrodeposition and electroless deposition of metallic powders were comparatively investigated. Electrodeposition of copper is accompanied with the simultaneous hydrogen evolution, which significantly influences the morphology of Cu powder. At lower overpotentials, branched dendrites were produced. At higher overpotentials honeycomb-like deposits of copper were obtained. Formation of silver powders was characterized by the comparison of the exchange and limiting current densities. Instantaneous growth of dendrites starts at low overpotential due to large exchange current density in silver nitrate solution. Formation of powders such as Ni, Co, Ag, Pd and Au from homogenous solutions using an appropriate reducing agent or via galvanic displacement reaction was demonstrated. The hydrolysis of metallic ions is crucial in the deposition metallic powders via electroless deposition from homogenous solutions. Oxides, such as Ag 2O, Cu 2O and CuO, suspended in water can successfully be reduced with an appropriate reducing agent, leading to the precipitation of metallic powders

CORRELATION OF MORPHOLOGIC AND PRODUCTION TRAITS OF HONEY BEE COLONIES FROM SERBIA

Abstract: State of mutual or reciprocal relationship between traits is determined by the correlation coefficients. Correlation of morphological and production traits was determined in two generations of honey bee colonies. In the first generation, mother queen bees were studied, and in the second generation, their offspring. The study of one generation lasted two years. Morphological traits were determined in the beginning of the study and production traits were determined in the spring and autumn inspections of every year. In the first generation, the positive and mostly high correlation between morphological traits, and honey yield and hygienic behaviour was determined. Correlation of morphological traits, colony strength and food supplies per colony ranged from highly positive to slightly negative values. It was found that there was a high correlation between some production traits (colony strength in the spring and autumn inspections and honey yield per colony). In the analysis of offspring (second generation), most traits that were positively correlated in mother generation now, also, showed a similar relationship. The only difference, in contrast to mother generation, was that, for most traits, the intensity of interaction increased

Promene linearnih i nelinearnih mera nizova RR i QT intervala posle uzimanja piva

BACKGROUND: /Aim. There are only several studies on the acute effect of alcoholic drinks intake on heart rhythm and this phenomenon is still not well understood. We wanted to examine whether linear and nonlinear measures of RR interval and QT interval series could quantify the effect of beer in healthy subjects. Methods. Eighteen young volunteers drank 500 mL of beer (21 g of ethanol). Electrocardiogram (ECG) recordings were taken in supine position: 20 minutes before (relaxation) and 60 minutes after drink intake. The RR interval series and the QT interval series were extracted from ECG and we calculated short-term (α1) and long-term (α2) scaling exponents and sample entropy (SampEn) for both series; low frequency (LF) and high frequency (HF) spectral components from RR interval series and QT variability (QTV). Blood pressure was measured every 10 minutes. Results. It was shown that beer induced changes in variability and correlation properties of these series. Immediate effect of beer intake was detected as a transient increase in the QT variability, heart rate and blood pressure. Delayed effects of beer were shortening of the RR and QT intervals and reduction of the HF spectral component. Beer intake also increased short-term scaling exponent (α1) of the RR time series and long-term scaling exponent (α2) of the QT time series. Conclusion. Our results suggest that acute effects of beer are reduced parasympathetic control of the heart and changed dynamic complexity of the ventricular repolarization.Uvod/Cilj. Akutni efekat uzimanja alkoholnih pića na kardiovaskularne ritmove je fenomen koji još uvek nije dovoljno razjašnjen i u literaturi postoji svega nekoliko radova na tu temu. Cilj rada je bio da se ispita da li se linearnim i nelinearnim merama nizova RR i QT intervala može kvantifikovati akutni efekat male količine piva kod zdravih osoba. Metode. Osamnaest mladih zdravih muškaraca je pilo po 500 mL piva (21 g etanola). Elektrokardiogram (EKG) je beležen u ležećem položaju: 20 minuta pre (u relaksaciji) i 60 minuta neposredno posle uzimanja pića. Iz digitalizovanog zapisa EKG-a izdvojeni su nizovi RR i QT intervala. Iz oba niza smo izračunali kratkodometni (α1) i dugo-dometni skalirajući eksponent (α2), kao i entropiju uzorka (SampEn). Iz nizova RR intervala određene su spektralne komponente niskofrekventnih (LF) i visokofrekventnih (HF) opsega, a iz nizova QT intervala varijabilnost QT intervala (QTV). Krvni pritisak je bio meren svakih 10 minuta. Rezultati. Pokazali smo da pivo menja varijabilnost i korelacione osobine ovih nizova. Neposredni efekat uzimanja piva ogleda se u prolaznim povećanjima QT varijabilnosti, srčane frekvence i krvnog pritiska, a produženi u skraćenju dužine RR i QT intervala i smanjenju spektralne komponente HF. Uzimanje piva je takođe dovelo do porasta kratkodometnog skalirajućeg eksponenta (α1) RR niza i dugodometnog skalirajućeg eksponenta (α2) QT niza. Zaključak. Akutni efekat uzimanja piva je redukovana parasimpatička kontrola srca i izmenjena kompleksnost dinamike ventrikularne repolarizacije