Volume 8, No. 2 (2007)
Articles
PREDICTION OF THE LIQUID CRYSTALLINE BEHAVIOR FOR SOME BIS PHENIL AROMATIC DERIVATIVES WITH ARTIFICIAL NEURAL NETWORKS
CATALIN LISA*, VICTOR BULACOVSCHI
Artificial neural networks (ANN) are robust and efficient mathematical tools inspired by the biological nervous system, and can be used to simulate a wide variety of complex scientific and engineering problems. A powerful ANN function is determined largely by the interconnections between artificial neurons, similar to those occurring in their natural counterparts of biological systems. Neural network based method proved to be able to appreciate the liquid crystalline behavior with small errors, so it represents an effective tool for structure – properties prediction. The most common type ANN with multiple layers has been used in this work.
AN EFFICIENT SYNTHESIS OF CAMALEXIN ANALOGOUS
M. CHIGR(1)*, E.H. OUKANI(1), S. EL KAZZOULI(2), A. MOUADDIB(1), G. GUILLAUMET(2)
A convenient method for the synthesis of 3-thiazolylindoles has been proposed. This synthesis is based on the condensation of bromoacetylindole with thioureas.
VOLTAMMETRIC DETECTION OF DIQUAT AT THE CARBON PASTE ELECTRODE CONTAINING Ca10(PO4)6(OH)2
M.A. EL MHAMMEDI(1), M. BAKASSE(2), A. CHTAINI(1)AND*
We report a sensitive electrochemical voltammetric method for analyzing diquat (DQ) ions using a carbon paste electrochemical (CPE) modified by porous material, such as hydroxyapatite (HAP). Diquat strongly adsorbed on a HAP-CPE surface and provides facile electrochemical quantitative methods for electroactive DQ ions. Operational parameters have been optimized, and the stripping voltammetric performance has been studied using square wave voltammetry. The peaks current intensity are highly linear over the 7×10-7–3×10-4 mol.L-1 diquat range examined (10 min accumulation time), with a good sensitivity. These findings can lead to a widespread use of electrochemical sensors to detect DQ contaminates. Scanning electron microscopy (SEM) was used for morphology observation and in particular the X-ray diffraction analysis (XRD) and Fourier transformed infrared spectroscopy (FTIR) analysis for characterization of synthesis powder.
SELECTIVE SEPARATION OF METALS BY A NEW SORBENT, THE POLYETHYLENIMINE METHYLENEPHOSPHONIC ACID (PEIMPA)
OMAR ABDERRAHIM(1), MOHAMED AMINE DIDI(1)*ANDBERNARD MOREAU(2), DIDIER VILLEMIN(2)
A new sorbent, the polyethylenimine methylenephosphonic acid (PEIMPA), was synthesized from commercially available polyethylenimine. After characterization by (1H, 13C, 31P) NMR, elementary analysis, UV/VIS and FTIR, the new ion exchange polymer PEIMPA has been investigated in liquid – solid extraction of a mixture of Cd(II), Co(II), Cu(II), Fe(III), Ni(II), Pb(II) and Zn(II) cations from a mineral residue of zinc ore dissolved in nitric acid. The selectivity of this polymer was studied as a function of pH. PEIMPA can sorb much higher amounts of Fe ion than Cd, Co, Cu, Ni, Pb and Zn ions. The recovery of Fe(III) is almost quantitative. Because of this remarkable affinity, the PEIMPA resin has potential for application in several fields. Further studies of the polymer are in progress.
STUDY OF THE KINETICS OF p-COMPLEXES FORMATION IN OIL-IODINE SYSTEM
R. STURZA*, C. POPOVICI, O. DESEATNICOV, S. HARITONOV
The use of the iodinated sunflower oil represents a cheap accessible method for the iodine deficiency eradication along with other iodine sources. A small amount of iodinated oil (0.25 – 1%) incorporated in the product can represent a significant source of iodine for the human body. The possibility and capacity of the molecular iodine incorporation in the sunflower oil was studied. It was established that during oil iodination the iodine is not simply added to the oil, but a process of fixation of molecular iodine to the double bond with p complexes formation takes place without double bond from the unsaturated fatty acids being broken. Kinetic parameters of the p compounds iodine – triglycerides formation in the sunflower oil were investigated. It was established that the process is described by a first order kinetic reaction. The reaction constant values and the half-time values were established: h-1 and h (for T = 298 K).
EVALUATING OF SOME FUNCTIONAL PROPERTIES OF THE MYOFIBRILLAR PROTEIN CONCENTRATE FROM THE BEEF HEART
AURELIA IONESCU, IULIANA APRODU, MARGARETA ZARA*, AIDA VASILE, LENUTA PORNEALA
We have analyzed from a chemical and functional point of view the myofibrillar protein concentrate obtained by repeatedly washing of the minced beef heart with a solution of phosphate buffer with/without added NaCl or antioxidants (PG – propyl gallate and BHA – butylhydroxyanisol) in cooled potable water. We determined the effect of washing solutions on the yield recovery of myofibrillar proteins, on their solubility in SDS (pH = 8.0) and in sodium chloride solutions 0.6 M (pH = 6) and on maintaining the stability of the myofibrillar protein concentrate of beef heart (MPCBH) during the refrigerated storage of the product. Moreover, the rheological properties of MPCBH were studied to prove the effect that the washing environment and temperature have on the shear flow behaviour.
MILLING PROPERTIES OF SOME ROMANIAN RYE VARIETIES
IULIANA BANU*, CONSTANTIN MORARU
The milling properties of cereals can be investigated through their milling at laboratory aggregates. The milling indices can be calculated on the basis of the experimental results. In this article we have investigated the milling properties of four Romanian rye varieties. The milling has been made at the Buhler laboratory aggregate using a modified technical scheme (with pre-grinding). The values obtained for the milling indices calculated are inferior to those mentioned in the literature for wheat. The experimental results pointed out the contribution of the main physical properties of rye to the intrinsic milling value, as well as the importance of some factors related to the milling aggregate, to the technical scheme used.
BIOCHEMICAL PROCESSES BY MASHING AND CHARACTERIZATION OF THE FERMENTATION OF FEED BARLEY DURING BREWING
GUNKA YONKOVA(1), NELI GEORGIEVA(1)*, TAMARA GINOVA(2), ANNA TERZI(2)
The purpose of the present work is to investigate the possibilities for the usage of feed barley in the brewing process. It is proved that using feed barley and the enzyme products Ceremix 2XL and Ultraflo L, the formed wort is richer in ?-amine nitrogen and the viscosity is almost the same as the one of the control liquid. No sufficient difference in fermentation ratio and period was found, comparing sample and control. The physical and chemical properties of the ready beer were almost the same as those of the control one. The most notable differences are concerning the vinyl acetate diketones concentration.
THE ROLE OF EPINEPHRINE AND NOREPINEPHRINE ON GLUCAGON-INDUCED THERMOGENESIS IN DUCKLING (CARINA MOSCHATA): A HPLC STUDY
M. SLIMANI(1), S. EL ANTRI(2), S.LAZAR(2), H. BARRÉ(3), M. KHOUILI(2), K. SENDID(4), T. FECHTALI*(1)
Physiological studies have shown that glucagon is a potential mediator of nonshivering thermogenesis (NST) in birds. The present work was undertaken in order to investigate whether the observed thermogenesis results from a direct action of glucagon on avian thermoregulatory mechanisms or in fact requires the participation of the catecholamines. We focused our study on the effects of central glucagon on plasma catecholamine and heart rate on cold acclimated (CA) ducklings in cold environment. Our results showed that cold exposure (4 °C) induced an increase of circulating norepinephrine (NE) in thermoneutral (TN) and CA (42 % and 43 % respectively), while epinephrine (E) decreased only in TN (-45%). After glucagon injection, we found that circulating E increase in TN and CA (280%, 516% respectively), whereas NE concentrations decreased only in TN ducklings (-23%). Injection of glucagon causes a decrease in heart rate in TN duckling whereas it has no effect on CA ducklings. The large increase in E levels in CA and TN ducklings may be due to a massive release of adrenal catecholamine in response to the conditions below.
KLEBSIELLA PNEUMONIAE PRODUCTRICES DE BETA–LACTAMASES A SPECTRE ELARGI (BLSE) ISOLEES DANS LES HOPITAUX DE LA VILLE DE ANNABA, ALGERIE
FARAH ABID(1), BOUTEFNOUCHET NAFISSA*(1), DEKHIL MAZOUZ(2)
The problem of antibiotic resistance is strictly considered a hospital one and reserved to bacteria responsible of nosocomial infections. During the last years, several investigations have shown the increasing role of Klebsiella pneumoniae in the intra-hospital infections. In this work, we investigate the presence of this species at hospitalized patients and within their environment in order to estimate the relationships between the two reservoirs and evaluate the resistance to antibiotics of this opportunist pathogen.
A PRELIMINARY IMPACT STUDY UPON THE ENVIRONMENT FACTORS IN THE CASE OF DEPOLLUTION OF WASTEWATERS FROM THE PULP INDUSTRY WITH MIXTURES OF PHOSPHORIC ACID AND DIAMMONIUM PHOSPHATE
IRINA IFRIM(*), DOMNICA CIOBANU, GABRIELA ANDRIOAI
For a long period of time the problem of the economic reability has been given much importance excluding the environmental protection problems. Industrialization has interfered more and more in the natural environment with an effect of deterioration, one of the causes being the exploitation of the natural resources, in the studied case the ligneous mass, without the integral estimation of this. Through the implementation of the method of quantification of the impact of technological solution proposed against the environmental factors, through graphical representation, the calculation of the quality indices of the environment a conclusion has been arrived at: according to the graphical method, the existent activity through the methods of cleaning has a major impact upon water as an environmental factor, its reduction being at the same time the challenge given by the present research.