science SERIA B

Chimie și Știința Materialelor

Excelență în Cercetare

Din 1929

Arhiva Online

DETERMINATION OF THE TECHNICAL QUALITY INDICES OF VEGETABLE OILS BY MODERN PHYSICAL TECHNIQUES

person Nicoleta CHIRA, Cristina TODAªCÃ, Alina NICOLESCU, Gabriela PÃUNESCU, Sorin ROªCA
This work presents the use of proton nuclear magnetic resonance spectroscopy and gas-chromatography for the determination of quality indices of vegetable oils. Based on the 1H-NMR data, chemometric equations were developed, leading to the computation of the average molecular weight, iodine and...

ESTIMATION OF RADIONUCLIDE TRANSFER TIMES IN THE GEOLOGICAL LAYERS OF SALIGNY SITE

person Gheorghiþa JINESCU, Daniela DOGARU
This paper describes the assessment of 60Co and 137Cs transfer times in the geological layers of Saligny site which is selected for the construction of a radioactive waste repository. The geological aspects of Saligny site necessary to assess the transfer time of radionuclides are presented. The...

PROOFS FOR MOLECULAR IMPRINTING OF AN ACRYLIC COPOLYMER BY PHASE INVERSION

person ªtefan-Ovidiu DIMA, Tãnase DOBRE, Andrei SÂRBU, Marius GHIUREA, Corina BRADU
The molecular imprinting with diosgenin by phase inversion of some acrylic copolymer pearls was proved both by analyzing the liquid phase (the extracts) and the solid phase (the pearls). For this purpose, the pearls at different stages of treatment were dissolved in dimethylformamide (DMF) and...

SURFACE CHARACTERIZATION AND CORROSION BEHAVIOUR OF Ti BASED ALLOYS IN FETAL BOVINE SERUM

person Ioan-Viorel BRÂNZOI, Mihai IORDOC, Florina BRÂNZOI
The purpose of this study is to evaluate the influence of Al, V, Nb and Ni alloying elements on electrochemical behaviour and surface properties for Ti-Al-V, Ti-Al-Nb and Ti-Ni Nitinol-like alloys. These alloys are currently used in orthopaedic surgery for total hip and knee replacement. We used...

POTENTIOMETRIC STUDIES ON METHYL PYRIDINE DERIVATIVES OF 14-MEMBERED TETRAAZA MACROCYCLES AS SELECTIVE IONOPHORES FOR HEAVY METALS

person Alina C. ION, Judite COSTA, Ion ION, Dragoº GHERASE, Alina CULEÞU
The potentiometric study on methyl pyridine derivatives of 4-membered tetraaza macrocycles, used as a selective ionophore for heavy metal cations, showed a remarkable selectivity for Cd2+ and Pb2+. A new poly(vinyl)chloride PVC membrane electrode based on these ionophores was prepared and...

Fe3O4 AND CoFe2O4 NANOPARTICLES STABILIZED IN SODIUM ALGINATE POLYMER

person Cristina Ileana COVALIU, Cristian MATEI, Adelina IANCULESCU, Ioana JITARU, Daniela BERGER
Magnetite and cobalt ferrite nanoparticles have been widely used in magnetic resonance imaging, hyperthermia, magnetic drug delivery etc. In this paper, we report a facile, low cost route to prepare nanocomposites containing Fe3O4 or CoFe2O4 nanoparticles stabilized in sodium alginate polymer....

MEMBRANARY TECHNIQUES USED AT THE SEPARATION OF SOME PHENOLIC COMPOUNDS FROM AQUEOUS MEDIA

person Ioana DIACONU, Gheorghe NECHIFOR, Aurelia Cristina NECHIFOR, Elena RUSE, Eugenia EFTIMIE TOTU
The paper presents a separation study of some phenolic compounds frequently encountered in the environment: m-nitrophenol, p-nitrophenol, m-cresol, p-cresol, using the bulk liquid membranes technique. Using chloroform as the organic solvent for the membrane, the operational parameters of the...

MICROWAVE ASSISTED CATALYTIC DECHLORINATION OF PCB

person Adrian TRIFAN, Ioan CÃLINESCU
The purpose of this study is to investigate the catalytic dechlorination of PCB (polychlorinated biphenyls). The process is activated by conventional or microwave heating. Solutions of PCB in 2-propanol with concentrations between 0.01 and 0.1M were used for the catalytic dechlorination....

HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR THE DETERMINATION OF BENZOIC ACID IN BEVERAGES

person Cornelia Petronela ENE, Elena DIACU
The objective of the present contribution was the development of a fast and simple HPLC method for the identification and determination of the antimicrobial preservative benzoic acid in different food matrix. The method consists in the direct injection of the sample, after a prior filtration to...

EFFECT OF HYDROXYAPATITE ON INTERFACE PROPERTIES FOR ALLOY/BIOFLUID

person Mariana PRODANA, Dionezie BOJIN, Daniela IONIÞÃ
This paper is focused on surface properties of titanium and titanium alloys (TiAlZr, TiAlVMoFe) covered and uncovered with hydroxyapatite (HA). The coatings were obtained electrochemical using the potentiostatic method in aqueous solutions of 0.61mM Ca(NO3)2 and 0.36mM NH4H2PO4. Interface...

EXCESS PROPERTIES IN DIMETHYL SULFOXIDE + 1-BUTANOL AND 1,4-DIOXANE+1-BUTANOL BINARY MIXTURES AT 298.15 K

person Anca FEDELEª, Oana CIOCÎRLAN, Olga IULIAN
In this paper densities and viscosities of the binary systems dimethyl sulfoxide+1-butanol and 1,4-dioxane+1-butanol have been reported as function of composition at 298.15 K. The excess molar volumes, VE, viscosity deviation, , and excess Gibbs energy of activation of viscous...

ALUMINUM MELT CLEANLINESS PERFORMANCE EVALUATION USING PoDFA (POROUS DISK FILTRATION APPARATUS) TECHNOLOGY

person Carmen STANICÃ, Petru MOLDOVAN
The presence of solid non-metallic inclusions in aluminum alloys can cause reduction in mechanical properties of castings, increased gas porosity, poor machinability, decrease in fluidity and poor surface quality.\r\nTechniques for inclusions assessment can be: quantitative metallography,...

WALL THICKNESS - SOLIDIFICATION FEATURES CORRELATION OF DUCTILE IRON CASTINGS UNDER MOULD TYPE INFLUENCE

person Irina Varvara ANTON, Cristina MILITARU, Eduard Marius ªTEFAN, Nicoleta IVAN, Mihai CHIªAMERA, Iulian RIPOªAN
Some investigations on cooling curve parameters and microstructure of Ductile Iron solidification under mould type and wall thickness influence were made. Three types of moulds (furan resin, Na Silicate and clay-bentonite as binders) and five wall thickness (8, 14, 22, 31 and 40 mm respectively)...

INVESTIGATION OF SOME ELECTRICAL PROPERTIES OF NiTi WIRES PRESENTING THE SHAPE MEMORY EFFECT

person Gabriela JICMON, Georgeta COªMELEAÞǍ, Dan BATALU
Experimental results of resistivity measurements for two kinds of NiTi wires previously treated to have memory shape effect are presented in this paper. The samples were analised using DSC method. The increasing number of applications of memory shape alloys is reflected connected to an...

MELT SPUN Fe-Co-Cr-B-Si ALLOYS CORROSION CHARACTERIZATION

person Iulia SOLOMON, Nicolae SOLOMON
This paper presents the results of the research on the corrosion resistance of a new system of amorphous alloys, i.e. Fe-Co-Cr-B-Si. The corrosion behaviour of amorphous alloys as well as that of any other crystalline alloys may be determined both by internal factors (alloy structure and...