Analytic Functions with Negative Coefficients and Differential and Integral Operators

In this paper integral properties of some analytic functions with negative coefficients from certain classes of functions defined using Ruscheweyh differential operator are studied. The obtained results are sharp and they are improvement of some known results.     

Antioxidant activity evaluation by physiologically relevant assays based on haemoglobin peroxidase activity and cytochrome c-induced oxidation of liposomes

Two new protocols for exploring antioxidant-related chemical composition and reactivity are described: one based on a chronometric variation of a haemoglobin ascorbate peroxidase assay and one based on cytochrome c-induced oxidation of lecithin liposomes. Detailed accounts are given on their design, application, critical correlations with established methods and mechanisms. These assays are proposed to be physiologically relevant and bring new information regarding a real sample, both qualitative and quantitative. The well-known assays used for evaluation of antioxidant (re)activity are revisited and compared with these new methods. Extracts of the Hedera helix L. are examined as test case, with focus on seasonal variation and on leaf, fruit and flower with respect to chromatographic, spectroscopic and reactivity properties. According to the set of assays performed, winter are the most antioxidant, followed by summer leaves, and then by flowers and fruits.     

Modeling of L-lactide Polymerization by Reactive Extrusion

The kinetics of L-lactide ring-opening polymerization initiated by stannous octoate and triphenylphosphine was investigated in a batch apparatus (Haake Rheocord Mixer). Based on the experimental data, a kinetic model is developed, considering a coordination-insertion mechanism. Reactive extrusion experiments were further conducted for the same polymerization process, on a co-rotating twin screw extruder. The melted material flow and mixing was described by using the Ludovic® commercial simulator. Based on the developed kinetic model and simulated flow of L-lactide polymerization mixture, a mathematical model of reactive extrusion process is formulated, describing the evolutions of monomer conversion and average molecular weight along the extruder. The model is predicting with a reasonable good accuracy the experimental data.     

Antibacterial and Photocatalytic Properties of ZnO Nanoparticles Obtained from Chemical versus Saponaria officinalis Extract-Mediated Synthesis

In the present work, the properties of ZnO nanoparticles obtained using an eco-friendly synthesis (biomediated methods in microwave irradiation) were studied. Saponaria officinalis extracts were used as both reducing and capping agents in the green nanochemistry synthesis of ZnO. Inorganic zinc oxide nanopowders were successfully prepared by a modified hydrothermal method and plant extract-mediated method. The influence of microwave irradiation was studied in both cases. The size, composition, crystallinity and morphology of inorganic nanoparticles (NPs) were investigated using dynamic light scattering (DLS), powder X-ray diffraction (XRD), SEM-EDX microscopy. Tunings of the nanochemistry reaction conditions (Zn precursor, structuring agent), ZnO NPs with various shapes were obtained, from quasi-spherical to flower-like. The optical properties and photocatalytic activity (degradation of methylene blue as model compound) were also investigated. ZnO nanopowders’ antibacterial activity was tested against Gram-positive and Gram-negative bacterial strains to evidence the influence of the vegetal extract-mediated synthesis on the biological activity.     

g‐Engineering in Hybrid Rotaxanes To Create AB and AB2 Electron Spin Systems: EPR Spectroscopic Studies of Weak Interactions between Dissimilar Electron Spin Qubits

Hybrid [2]rotaxanes and pseudorotaxanes are reported where the magnetic interaction between dissimilar spins is controlled to create AB and AB₂ electron spin systems, allowing independent control of weakly interacting S= centers.     

A ring cycle: studies of heterometallic wheels

The synthesis of a series of heterometallic rings and chains is reported. The family is based on the octanuclear cages of general formula [H(2)NR(2)][M(7)M'F(8)(O(2)CR')(16)], where M is a trivalent metal (Cr, Fe, V, Al, Ga or In), M' is a divalent metal (Mn, Fe, Co, Ni, Mg, Zn, Cd), R is a linear alkyl chain and O(2)CR' is one of around twenty carboxylates. Other members of the family with nonametallic and decametallic cores are described, and some new physics is outlined, including initial investigations of the proposed application of [Cr(7)Ni] rings as Qubits in quantum information processing.     

Projective Systems of Imprimitivity and Applications for the Galilei Group in 1+2 and 1+3 Dimensions

The study of the projective unitary irreducible representations of the Galilei group (in 1+3 and 1+2 dimensions) is usually done using firstly some group extensions techniques (in this way one is reduced to the study of true unitary representations) and then Mackey induction procedure. In this paper we reobtain these results using a different approach based on the notion of projective systems of imprimitivity due also to Mackey. This extension of the usual Mackey procedure is presented rather extensively and illustrated by detailed computations concerning the classification of the projective unitary irreducible representations.     

A Study of L-Lactide Ring-Opening Polymerization Kinetics

Summary: The paper presents an experimental study of L-lactide polymerization in molten state using as initiator the Stannous Octoate. The experiments were performed in a Haake mixer. The operating temperatures were between 170 and 195°C, the reaction time up to 60 min and monomer to initiator initial molecular ratio between 10² and 5 · 10³. The conversion was determined by using ¹H NMR and the molecular weights distributions by SEC. A preliminary mathematical modeling study was also performed, based on experimental data and a previously published reaction scheme.     

Birefringence of binary liquid crystalline mixtures of MBBA and PPMAECOBA in TCM,interferometric assessment

Abstract

The mutual influence of two mesogenic components, namely a nematic liquid crystal N-(p-methoxy-bezylidene)-butylaniline (MBBA) and a lyotropic liquid crystal poly-(phenyl-methacrylic) ester of cetyloxybenzoic acid (PPMAECOBA) in tetra-chloromethane (TCM) is studied in this paper. The ordinary and extraordinary refractive indices of the mixtures, nematic liquid crystal and lyotropic liquid crystal were measured at 589.3?nm with a Rayleigh interferometer and some electro-optical parameters were computed. The main refractive indices, the birefringence, the main normalized polarizabilities and their difference are dependent on the mixture volumetric concentrations, proving the existence of the collective orientational interactions between the two types of liquid crystals.