The characterisation of dope dyed poly (ethylene terephthalate)

By analysing the polycondensation of ethylene glycol with dimethyl terephthalate, the influence of 1,4-aminoanthraquinone dyestuffs on the chemical and molecular properties of dope dyed poly(ethylene terephthalate) has been determined. The results show that dope dyed poly(ethylene terephthalate) differs from the uncoloured polymer by a possession of a higher amount of -COOH end groups and diethylene glycol units. The shape and the position of molecular weight distribution curves determined by gel permeation chromatography are also influenced by the soluble dyestuffs used.     

Synthesis of non-amphiphilic block copolymer with S-trityl-cysteine and pyrene units by ATRP polymerization: characterization and fluorescence study

A new diblock copolymer, 1-methylpyrene isobutyrate–poly(methyl methacrylate–block-N-acryloyl-S-trityl-cysteine)-Br (Py–PMMA–b-ATCys-Br), was synthesized by atom transfer radical polymerization (ATRP) of N-acryloyl-S-trityl-L-cysteine monomer (ATCys) with 1-methylpyrene isobutyrate–poly(methyl methacrylate)–Br as a macroinitiator. The diblock copolymer and its precursor were characterized by ¹H and ¹³C NMR spectroscopy, fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), gel permeation chromatography (GPC), and glass transition temperatures (Tg) measurements. Fluorescence properties of the diblock copolymer were investigated using various quenching (Cu²⁺, Hg²⁺, Fe²⁺, Fe³⁺, Co²⁺, Ni²⁺ and Pb²⁺) in dimethylformamide solutions, the more efficient quenchers being the Cu²⁺, Hg²⁺, Fe²⁺, and Fe³⁺ ions. In addition, the effect of in situ photogenerated silver nanoparticles on the copolymer fluorescence was also investigated.     

Resolution-based decision procedures for the universal theory of some classes of distributive lattices with operators

We establish a link between the satisfiability of universal sentences with respect to classes of distributive lattices with operators and their satisfiability with respect to certain classes of relational structures. This justifies a method for structure-preserving translation to clause form of universal sentences in such classes of algebras. We show that refinements of resolution yield decision procedures for the universal theory of some such classes. In particular, we obtain exponential space and time decision procedures for the universal clause theory of (i) the class of all bounded distributive lattices with operators satisfying a set of (generalized) residuation conditions, and (ii) the class of all bounded distributive lattices with operators, and a doubly-exponential time decision procedure for the universal clause theory of the class of all Heyting algebras.     

OM,SEM–EDX,and micro‐FTIR analysis of the Bronze Age pottery from the Băile Figa salt production site (Transylvania,Romania)

This article presents the results of analyses carried out on a lot of 11 fragments of Bronze Age ceramics discovered in the site from B?ile Figa (Beclean town, Transylvania, Romania), where salt exploitation occurred. The samples were analyzed by means of optical microscopy, on the basis of which the morphology and distribution of the inclusions in the ceramic paste was established. Likewise, the samples were analyzed by scanning electron microscopy with energy‐dispersive X‐ray spectrometry, producing microphotographs for each sample, and on the basis of the X‐ray spectra, the elemental composition in gravimetric percentages was established. Through the micro‐Fourier‐transform infrared spectroscopy analysis, on the basis of characteristic group vibrations, it was possible to ascertain the nature of the compounds from the ceramic samples. These analyses will contribute to the reconstruction of the prehistoric technologies for salt exploitation.     

PIST: An Efficient and Practical Indexing Technique for Historical Spatio-Temporal Point Data

Despite pressing need, current relational database management systems (RDBMS) support for spatio-temporal data is limited and inadequate, and most existing spatio-temporal indices cannot be readily integrated into existing RDBMSs. This paper proposes a practical index for spatio-temporal (PIST) data, an indexing technique, rather than a new indexing structure, for historical spatio-temporal data points that can be fully integrated within existing RDBMSs. PIST separates the spatial and temporal components of the data. For the spatial component, we develop a formal cost model and a partitioning strategy that leads to an optimal space partitioning for uniformly distributed data and an efficient heuristic partitioning for arbitrary data distributions. For the temporal component of the data a B^?+?-tree is used. We show that this layer’s performance can be maximized if an optimal maximal temporal range is enforced, and we present a procedure to determine such an optimal value. Being fully mapped onto a RDBMS, desirable and important properties, such as concurrency control, are immediately inherited by PIST. Using ORACLE as our implementation platform we perform extensive experiments with both real and synthetic datasets comparing its performance against other RDBMS-based options, as well as the MV3R-tree. PIST outperforms the former by at least one order of magnitude, and is competitive or better with respect to the latter, with the unarguable advantage that it can readily used on top of virtually any existing RDBMS.     

Special Issue of Selected Extended Papers of IJCAR 2020

Journal of Automated Reasoning -     

Amphiphilic polysilane with poly(ethylene oxide) side chains

The synthesis of an amphiphilic polysilane with poly(ethylene oxide) grafted segments (PS-g-PEO) through the addition of an allyl-terminated poly(ethylene oxide) (AT-PEO) to poly[diphenylsilane-co-methyl(H) silane] (PSH) in a homogeneous system and using catalyst platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane is reported The process involves the activation of the polymer by microwave irradiation as a preliminary stage with the view to perform the subsequent addition stage at room temperature, when side reactions are prevented. The PS-g-PEO structure was characterized by NMR, FT-IR spectral analysis and GPC methods. The amphiphilic properties were estimated by comparison of the water sorption isotherms of the PS-g-PEO copolymer with those of the component segments. The core-shell micellization in water and the morphological aspects of the self-assembled structures were investigated by DLS and SEM. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Combined FPPE–PTR Calorimetry Involving TWRC Technique II. Experimental: Application to Thermal Effusivity Measurements of Solids

Photopyroelectric calorimetry in the front detection configuration (FPPE) and photothermal radiometry (PTR) were simultaneously used, together with the thermal-wave resonator cavity method (TWRC), in order to investigate the thermal effusivity of solids inserted as backing layers in a detection cell. A new combined FPPE–PTR–TWRC setup was designed. It was demonstrated experimentally that the PTR technique, combined with the TWRC method, is able to provide calorimetric information about the third layer of a detection cell. Applications on solids with different values of the thermal effusivity (starting from metals, down to thermal isolators) are presented. The values of the thermal effusivity obtained with the PTR technique are similar to those obtained with the PPE technique, and in agreement with literature values; the two methods reciprocally support each other. The accuracy of both methods is higher when the values of the thermal effusivity of the backing layer and coupling fluid are close.     

Sol–gel preparation and characterization of perovskite lanthanum lithium titanate

Lanthanum lithium titanate, belonging to the solid solution La_0.66Li_0.33TiO₃, was prepared by sol–gel method from LiNO₃, La(NO₃)₃·6H₂O and Ti(OC₄H₉)₄ in ideal cation stoichiometry for La_0.66Li_0.33TiO₃. The synthesized product was characterized by X-ray powder diffractometry (XRD) and thermal analyses (DTA-TG). Electron microscopy investigations (SEM and TEM) was used to evaluate the morphology of synthesized La_0.66Li_0.33TiO₃. The bulk quantities of nano-sized particles of layered La_0.66Li_0.33TiO₃ have been obtained at 1,000°C using the modified sol–gel method. The mean diameter of La_0.66Li_0.33TiO₃ nano-crystals was about 123 nm.     

Conformations of polysulfone‐block‐polydimethylsiloxane chains in solution and in the solid state

Polysulfone block copolymers containing polydimethylsiloxane segments were obtained in solution by the condensation reaction of chloro‐terminated polysulfone oligomers and α,ω‐dihydrogensilyl‐polydimethylsiloxane. The conformations of the copolymer chains were investigated both in solution and in the solid state. Viscometric and UV absorption measurements were carried out in dilute dichloroethane solutions over a wide region of concentrations, in the temperature range 20–75 °C. The results point to a conformational transition phenomenon, located at around 55 °C, which is attributed to the transition from a segregated to a pseudo‐Gaussian conformation through a compressed‐segregated conformation. Copyright © 2004 Society of Chemical Industry