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Search Results: 1 - 10 of 662 matches for " Gheorghe Borodi "
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Structural characterization of ambazone salt with niflumic acid
Irina Kacso,Lucia Rus,Mircea Pop,Gheorghe Borodi,Ioan Bratu
Spectroscopy: An International Journal , 2012, DOI: 10.3233/spe-2012-0570
Abstract: Salt formation is a good method of increasing solubility, dissolution rate and consequently the bioavailability of poor soluble acidic or basic drugs [Polymorphism in Pharmaceutical Solids, Drugs and the Pharmaceutical Sciences, Vol. 192, 2nd edn, Informa Healthcare, New York, 2009]. The aim of this study was to obtain and to investigate the structural properties of the compound obtained by solvent drop grinding (SDG) method [Chem. Commun. (Camb.) 20 (2002), 2372–2373] at room temperature starting from the 1:1 molar ratios of ambazone (AMB) and niflumic acid (NIA). The thermal behavior of the obtained compound (AMB?·?NIA) was investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG), the thermal diffusivity and effusivity parameters were determined by photothermal radiometry (PTR). The structural characterization was performed with X-ray powder diffraction (XRPD) and infrared spectroscopy (FTIR). XRPD data and FTIR spectra demonstrated a new structure for AMB?·?NIA compound as compared to those of the starting materials.
Characterization and assessment of potential environmental risk of tailings stored in seven impoundments in the Aries river basin, Western Romania
Erika Levei, Tiberiu Frentiu, Michaela Ponta, Claudiu Tanaselia, Gheorghe Borodi
Chemistry Central Journal , 2013, DOI: 10.1186/1752-153x-7-5
Abstract: Tailings were found to be highly contaminated with several hazardous/priority hazardous metals (As, Cu, Cd, Pb), and pose potential contamination risk for soil, sediments, surface and groundwater. Two out of the seven studied impoundments does not satisfy the criteria required for inert wastes, shows acid rock drainage potential and thus can contaminate the surface and groundwater. Three impoundments were found to be highly contaminated with As, Pb and Cd, two with As and other two with Cu. The tailings impoundments were grouped based on the enrichment factor, geoaccumulation index, contamination factor and contamination degree of 7 hazardous/priority hazardous metals (As, Cd, Cr, Cu, Ni, Pb, Zn) considered typical for the studied tailings. Principal component analysis showed that 47% of the elemental variability was attributable to alkaline silicate rocks, 31% to acidic S-containing minerals, 12% to carbonate minerals and 5% to biogenic elements. Leachability of metals and ions was ascribed in proportion of 61% to silicates, 11% to acidic minerals and 6% to the organic matter. A variability of 18% was attributed to leachability of biogenic elements (Na, K, Cl-, NO3-) with no potential environmental risk. Pattern recognition by agglomerative hierarchical clustering emphasized the grouping of impoundments in agreement with their contamination degree and acid rock drainage generation potential.Tailings stored in the studied impoundments were found to be contaminated with some hazardous/ priority hazardous metals, fluoride and sulphate and thus presents different contamination risk for the environment. A long term monitoring program of these tailings impoundments and the expansion of the ecologization measures in the area is required.Exploitation of mineral resources containing base and precious metals is one of the main activities that have contributed to the development of humanity. In the same time, mining has a negative reputation because of the large amounts of as
N-Butyl-4-butylimino-2-methylpentan-2-aminium (E)-quercetinate
Ioana-Georgeta Grosu,Gheorghe Borodi,Mihaela Maria Pop
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812031170
Abstract: The title salt, C14H31N2+·C15H9O7 , was obtained in the reaction of quercetin with n-butylamine in a mixture of acetone and hexane. The crystal structure determination shows that the quercetin donates one of its phenol H atoms to the N-butyl-4-butylimino-2-methylpentan-2-amine molecule. The crystal structure of the salt is stabilized by intramolecular (N—H...N for the cation and O—H...O for the anion) and intermolecular hydrogen bonding (N—H...O between cation–anion pairs and O—H...O between anions). Quercetin molecules form dimers connected into a two-dimensional network. The dihedral angle between the quercetin ring systems is 19.61 (8)°.
Obtaining and Characterizing Alginate/k-Carrageenan Hydrogel Cross-Linked with Adipic Dihydrazide
Violeta Pa?cal?u,Violeta Popescu,George L. Popescu,Mircea C. Dudescu,Gheorghe Borodi,Adrian M. Dinescu,Marioara Moldovan
Advances in Materials Science and Engineering , 2013, DOI: 10.1155/2013/380716
Abstract: The aim of this paper is obtaining and characterizing hydrogels based on different ratios of oxidized alginate (oA) and k-carrageenan (C), chemically cross-linked with adipic dihydrazide (adh). The alginate (A) was first oxidized with sodium metaperiodate in order to transform it into the dialdehyde derivative, a more reactive compound than alginate. A known procedure for oxidation of alginate with sodium metaperiodate in ethanol-water in order to improve alginate reactivity by transforming the hydroxyl end-groups into dialdehyde was used, preceded by a partially cleavage of the alginate chains. In the second stage, the mixture of dialdehydic derivative of oxidized alginate, k-carrageenan and glycerol subjected to reaction with adipic dihydrazide leads to a Semi-Interpenetrated Network covalently cross-linked alginate/k-carrageenan hydrogel (oACadh), based on the dihydrazone compound which is responsible for the chemical cross-linking. Pure alginate, k-carrageenan, oxidized alginate, adipic dihydrazide and the cross-linked hydrogel were characterized by: FTIR, XRD, and SEM. 1. Introduction Our researches related to the development of hydrogels based on natural polysaccharides have focused on finding more biocompatible, nontoxic materials for biomedical applications. We already reported the influence of different alginate/k-carrageenan ratios on the properties of calcium cross-linked obtained hydrogels [1]. In this work we propose chemically cross-linking of alginate/k-carrageenan hydrogel using adipic dihydrazide and the study of possible synergistic effects on the mechanical properties and swelling behaviour of the obtained hydrogel. Sodium alginate and k-carrageenan are two polysaccharides of interest, used in drug delivery systems [2, 3] due to their biocompatibility, biodegradability, immunogenicity, and nontoxicity [4]. Alginates are naturally derived polysaccharide block copolymers composed of regions of -D-mannuronic acid monomers (M-blocks), regions of -L-guluronic acid (G-blocks), and regions of interspersed M and G units [5, 6]. Alginate is one of the polyuronates, an example of natural ionic polysaccharide forming chain-chain association leading to hydrogels with divalent cations (e.g., Ca2+) [7]. Carrageenans are a family of sulphated linear polysaccharides consisting of (1→3)-linked -galactose and (1→4)-linked -D-galactose units, which are variously substituted and modified to the 3,6-anhydro derivative, depending on the source and extraction conditions [8]. The units are bound by alternation of α-1,4 and -1,4 glycosidic linkages. Three
Learning the Business  [PDF]
Mike Holcombe, Marian Gheorghe
Creative Education (CE) , 2012, DOI: 10.4236/ce.2012.32042
Abstract: Developing software is a highly creative process. This paper describes a novel approach to teaching software engineering which involves university students working in partnership with external clients from business, charities and the public sector building solutions to their business and other problems. The paper describes the basic principles behind these activities and focuses on the experiences of teaching advanced students through the medium of a commercial software development company specifically set up to be run by the students as part of their degree course. The evidence from student and employer feedback demonstrates that this approach has been highly successful for the past 20 years or so but despite this it has rarely, if ever, been replicated elsewhere.
Chern classes of integral submanifolds of some contact manifolds
Gheorghe Piti
International Journal of Mathematics and Mathematical Sciences , 2002, DOI: 10.1155/s0161171202203403
Abstract: A complex subbundle of the normal bundle to an integral submanifold of the contact distribution in a Sasakian manifold is given. The geometry of this bundle is investigated and some results concerning its Chern classes are obtained.
Some Methods for Developing Economy through Resources’ Restrictions in the Contemporary Crisis
Gheorghe Savoiu
The Romanian Economic Journal , 2008,
Gheorghe Oprescu
Romanian Journal of European Affairs (RJEA) , 2003,
Abstract: Romania is trying for some time to launch the deregulation and liberalization processes, absolutely necessary for economic development. Unfortunately, many persons in Romania consider competition as a harmful force, the cause of the hardships faced by indigenous firms. Our analysis will show that competition is indeed harmful not to all but only to inefficient firms. The role assigned to competition policy is to cure market failures. These failures may spring from two sources: business activity and government regulation. The former cause of monopoly and inefficiency is dealt with by legislation, the latter by lobbying decision-makers.
On the Persistence Layers in Relational Databases with Multiple Concurrent Connections
Gheorghe Faur
Journal of Applied Computer Science & Mathematics , 2008,
Abstract: Very often, especially in the public sector, arise the need to cope with multiple concurrent connection to a database that might lay on a limited hardware platform, having poor technology resources so, in this case, by intercalary a persistence layer between the database and logical layer could solve the problem with efficiency and flexibility.
Gheorghe Jigau
Soil Forming Factors and Processes from the Temperate Zone , 2012,
Abstract: No abstract.
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