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21.
Cebrucean Dumitru Cebrucean Viorica Ionel Ioana 《Clean Technologies and Environmental Policy》2020,22(1):153-169
Clean Technologies and Environmental Policy - Coal-fired power plants are the largest source of carbon dioxide (CO2) emissions into the atmosphere, and these emissions can be effectively reduced by... 相似文献
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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. 相似文献
24.
Viorica Sofronie-Stokkermans 《Journal of Symbolic Computation》2003,36(6):891-924
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. 相似文献
25.
Viorica Vasilache Valerii Kavruk Felix‐Adrian Tencariu 《Microscopy research and technique》2020,83(6):604-617
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. 相似文献
26.
PIST: An Efficient and Practical Indexing Technique for Historical Spatio-Temporal Point Data 总被引:1,自引:0,他引:1
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. 相似文献
27.
Journal of Automated Reasoning - 相似文献
28.
Dorin Dadarlat Mircea Nicolae Pop Mihaela Streza Stephane Longuemart Michael Depriester Abdelhak Hadj Sahraoui Viorica Simon 《International Journal of Thermophysics》2011,32(10):2092-2101
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. 相似文献
29.
Ionela Carazeanu Popovici Elisabeta Chirila Viorica Popescu Victor Ciupina Gabriel Prodan 《Journal of Materials Science》2007,42(10):3373-3377
Lanthanum lithium titanate, belonging to the solid solution La0.66Li0.33TiO3, was prepared by sol–gel method from LiNO3, La(NO3)3·6H2O and Ti(OC4H9)4 in ideal cation stoichiometry for La0.66Li0.33TiO3. 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 La0.66Li0.33TiO3.
The bulk quantities of nano-sized particles of layered La0.66Li0.33TiO3 have been obtained at 1,000°C using the modified sol–gel method. The mean diameter of La0.66Li0.33TiO3 nano-crystals was about 123 nm. 相似文献
30.
Maria Bercea Anton Airinei Viorica Hamciuc Aurelia Ioanid 《Polymer International》2004,53(11):1860-1865
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 相似文献