Two component butterfly hysteresis in Ru1222 ruthenocuprate

We report detailed studies of the ac susceptibility butterfly hysteresis on the Ru1222 ruthenocuprate compounds. Two separate contributions to these hysteresis have been identified and studied. One contribution is ferromagnetic-like and is characterized by the coercive field maximum. Another contribution, represented by the so called inverted maximum, is related to the unusual inverted loops, unique feature of Ru1222 butterfly hysteresis. The different nature of the two identified magnetic contributions is proved by the different temperature dependences involved. By lowering the temperature the inverted peak gradually disappears while the coercive field slowly raises. If the maximum dc field for the hysteresis is increased, the size of the inverted part of the butterfly hysteresis monotonously grows while the position of the peak saturates. In reaching saturation exponential field dependence has been demonstrated to take place. At T = 78 K the saturation field is 42 Oe.Comment: 5 pages, 5 figure

Network theory approach for data evaluation in the dynamic force spectroscopy of biomolecular interactions

Investigations of molecular bonds between single molecules and molecular complexes by the dynamic force spectroscopy are subject to large fluctuations at nanoscale and possible other aspecific binding, which mask the experimental output. Big efforts are devoted to develop methods for effective selection of the relevant experimental data, before taking the quantitative analysis of bond parameters. Here we present a methodology which is based on the application of graph theory. The force-distance curves corresponding to repeated pulling events are mapped onto their correlation network (mathematical graph). On these graphs the groups of similar curves appear as topological modules, which are identified using the spectral analysis of graphs. We demonstrate the approach by analyzing a large ensemble of the force-distance curves measured on: ssDNA-ssDNA, peptide-RNA (system from HIV1), and peptide-Au surface. Within our data sets the methodology systematically separates subgroups of curves which are related to different intermolecular interactions and to spatial arrangements in which the molecules are brought together and/or pulling speeds. This demonstrates the sensitivity of the method to the spatial degrees of freedom, suggesting potential applications in the case of large molecular complexes and situations with multiple binding sites

Kinetics and mechanism of synthetic CoS oxidation process

The results of investigation of kinetics and mechanism for synthetic a-CoS oxidation process are presented in this paper. Based on experimental data obtained using DTA and XRD analysis and constructed PSD diagrams for Co-S-O system, mechanism of synthetic a-CoS oxidation process is suggested. Characteristic kinetic parameters were obtained for experimental isothermal investigations of desulfurization degree using Sharp method

Uticaj pola na karakteristike trbušno-rebarnog dela svinja hranjenih sa dodatkom sojinog ulja

Total of 40 castrated fatteners of Swedish Landrace breed, divided into two groups based on their gender (20 pigs in each group) were used in the study to determine the effect of gender on share of tissues and chemical composition of the fat taken from the belly carcass part. All pigs were fed diet containing additive of 1.25% of soybean oil. Even though the weight of belly part was similar in animals of both genders, female animals had higher share of muscle tissue (P lt 0.05), whereas male animals had higher share of intermuscular and total fat tissue (P lt 0.01). Addition of soybean oil, with high share of PUFA, to pig nutrition can significantly influence the increase of unsaturated fats. Female fatteners had more extracted fat in fat tissue and higher content of PUFA, however, statistically significant difference was established only in share of SFA, which was considerably lower (P lt 0.05) in comparison to male animals. Consequently, PUFA:SFA ratio was significantly higher in female animals (0.51) compared to male fatteners (0.39). Iodine number/value determined for fat was in the range from 63.00 in males to 64.36 in female animals without statistically significant difference. Based on obtained results it can be concluded that, in regard to the nutritional quality, belly part from female fatteners may provide a balanced fatty acid intake for consumers (PUFA:SFA>0.4). However, in regard to the technological quality, fat (bacon) obtained from female animals had lower sustainability, due to more rapid fat oxidation, and it was of poorer technological quality due to softer fat tissue and more difficult cutting.Ukupno 40 kastriranih tovljenika rase švedski landras, podeljenih u dve grupe u zavisnosti od pola (po 20 svinja u grupi), je iskorišćeno za utvrđivanje uticaja pola na udeo tkiva i hemijski sastav masti trbušno-rebarnog dela. Sve svinje su hranjene sa dodatkom 1,25% sojinog ulja. Pol životinja nije značajno uticao na težinu trbušno-rebarnog dela, međutim, utvrđeno je da su ženska grla imala veći udeo mišićnog tkiva (P lt 0,05), dok su muška imala veći udeo intermuskularnog i ukupnog masnog tkiva (P lt 0,01). Dodatak sojinog ulja, koje ima visok udeo PUFA, u ishranu svinja, može značajno da utiče na povećanje nezasićenosti masti. Ženski tovljenici su imali više ekstrahovane masti u masnom tkivu i veći sadržaj PUFA, međutim statistički značajna razlika je utvrđena samo u udelu SFA, koji je bio značajno niži (P lt 0,05) u odnosu na muška grla. Kao posledica toga, odnos PUFA:SFA je bio značajno veći kod ženskih grla (0,51) u odnosu na muška (0,39). Jodni broj masti se kretao od 63,00 kod muških do 64,36 kod ženskih životinja i nije se statistički značajno razlikovao. Na osnovu dobijenih rezultata može se zaključiti da je, u pogledu nutritivnog kvaliteta, trbušno-rebarni deo ženskih tovljenika kvalitetniji u pogledu masno-kiselinskog sastava (PUFA:SFA>0.4). Međutim, u pogledu tehnološkog kvaliteta, slanina dobijena od ženskih životinja bi imala manju održivost, usled brže oksidacije masti, i bila bi lošijeg tehnološkog kvaliteta, zbog mekanog masnog tkiva i otežanog sečenja

Uticaj dodavanja organskog selena na proizvodne karakteristike fazana

The effect of organic selenium as feed additive contained in the feed was investigated, applied in concentrations of 0.3 and 0.4 mg Se/kg mixture on production characteristics pheasant. The study was conducted on a total of 45 common pheasant individuals Phasianus colchicus, six weeks old, divided into three equal groups of 15 individuals for 60 days. The control pheasants group was fed with a standard mixture without addition of selenium during the experiment, while the mixture of group I contained 0.15 g/kg and pheasants group II had 0.20 g/kg additives with organic selenium. The results showed that different amounts of organic selenium presence in pheasants' feed had a positive effect on analyzed productivity indicators of pheasants' growth rate, both their final body weight and weight gain (p (lt) 0.05). Among examined groups of pheasant, gained differences in average feed conversion and total production index were not statistically significant (p> 0.05). The best production results were achieved by individual II group, which also had the highest selenium content in muscle tissue of the pectoral muscles, drumstick and thigh (p (lt) 0.05).Na osnovu sprovedenih istraživanja može se zaključiti da je upotreba organskog selena kao dodatka smešama za ishranu fazana imala povoljan učinak na ispitivane proizvodne rezultate i sadržaj selena u mišićnom tkivu i jetri. Najbolje proizvodne rezultate je postigla II grupa fazana u čijoj hrani je upotrebljen organski selen u koncentraciji od 0,4 mg/kg. Nešto niže vrednosti proizvodnih pokazatelja su ostvarili fazani I grupe, čija je smeša sadržavala 0,3 mg/kg selena, dok su najniže vrednosti ispitivanih parametara ustanovljene u K grupi. Rezultati ovog istraživanja pokazuju da fazani osim statusa lovne divljači mogu imati veliki značaj u proizvodnji kvalitetnog mesa sa značajnim sadržajem antioksidanta selena koji bi doprineo prevenciji raznih oboljenja imunog sistema i poboljšanja zdravlja ljudi. Takođe, sa ekonomske tačke gledišta optimatizacijom smeša za ishranu fazana koje sadrže selen može se racionalizovati konverzija hrane i ujedno smanjiti troškovi ishrane

Thermodynamics of a model for RNA folding

We analyze the thermodynamic properties of a simplified model for folded RNA molecules recently studied by G. Vernizzi, H. Orland, A. Zee (in {\it Phys. Rev. Lett.} {\bf 94} (2005) 168103). The model consists of a chain of one-flavor base molecules with a flexible backbone and all possible pairing interactions equally allowed. The spatial pseudoknot structure of the model can be efficiently studied by introducing a $N \times N$ hermitian random matrix model at each chain site, and associating Feynman diagrams of these models to spatial configurations of the molecules. We obtain an exact expression for the topological expansion of the partition function of the system. We calculate exact and asymptotic expressions for the free energy, specific heat, entanglement and chemical potential and study their behavior as a function of temperature. Our results are consistent with the interpretation of $1/N$ as being a measure of the concentration of $\rm{Mg}^{++}$ in solution.Comment: 11 pages, 4 figure

On Additivity of Heats of Atomization of Benzenoid Hydrocarbons

An additivity scheme, based on Clar\u27s formulae, is proposed for calculating heats of atomization of benzenoid hydrocarbons: Comparison between the results obtained by this scheme, by the semiempirical SCF MO model, and experimental findings is good. This satisfactory agreement, thus, presents independent support for Clar\u27s notion of isolated Jt sextets and migrating sextets

On the Topological Spectra of Composite Molecular Systems

It has been shown that topological spectrum of some large molecules comprises the complete set of eigenvalues of the topological matrix of some of their constituting fragments. Several relationships between the coefficients of the fragmental eigenvectors and those of the composite system have been derived. Some sufficient conditions that a system comprise a spectrum of its parts have been found and their use illustrated

On the Topological Spectra of Composite Molecular Systems

It has been shown that topological spectrum of some large molecules comprises the complete set of eigenvalues of the topological matrix of some of their constituting fragments. Several relationships between the coefficients of the fragmental eigenvectors and those of the composite system have been derived. Some sufficient conditions that a system comprise a spectrum of its parts have been found and their use illustrated