Volume 11, No. 4 (2010)
Articles
STUDY OF HYDRODYNAMICS IN FIXED BED OF COMPOSITE GRANULAR MATERIALS
IOAN SOLOMON, MARIUS SEBASTIAN SECULA, STELIAN PETRESCU(*)
This study aims at the experimental determination of pressure drop and friction factor at gas flow through fixed beds of granular silica gel, alumina and activated carbon, and establishment of an equation containing a modified friction factor Fm to calculate pressure drop. In order to calculate the modified friction factor, an equation was suggested. The experimental values for pressure drop and friction factor were determined using spherical grains of silica gel, cylindrical grains of alumina and silica gel, alumina and activated carbon impregnated with calcium chloride. By means of the suggested equation, the values of pressure drop in fixed bed were calculated and compared with the experimental values. A good agreement between the predicted and experimental data is noticed.
INSECTICIDAL ACTIVITIES OF ESSENTIAL OILS EXTRACTED FROM THREE SPECIES OF POACEAE ON ANOPHELES GAMBIAE SPP, MAJOR VECTOR OF MALARIA
GUÉVARA NONVIHO(1), VALENTIN D. WOTTO(1), JEAN-PIERRE NOUDOGBESSI(1), FÉLICIEN AVLESSI(1), MARTIN AKOGBETO(2), DOMINIQUE C.K. SOHOUNHLOUÉ(1*)
In this paper, the insecticidal activities on Anopheles gambiae spp of the essential oils (EO) extracted from the dry leaves of some species collected in Benin were studied. The essential oil yields are 2.8, 1.7 and 1.4% respectively for Cymbopogon schoanenthus (L.) Spreng (CS), Cymbopogon citratus Stapf. (CC) and Cymbopogon giganteus (Hochst.) Chiov (CG). The GC/MS analysis showed that the EO of CS had a larger proportion in oxygenated monoterpenes (86.3%) whereas those of the sheets of CC and CG are relatively close proportions (85.5% and 82.7% respectively) with. The piperitone (68.5%), δ 2-carene (11.5%), and α-eudesmol (4.6%) are the major components of the EO of CS while trans para-mentha-1(7),8-dien-2-ol (31.9%), trans para-mentha-2,8-dien-1-ol (19.6%), cis para-mentha-2,8-dien-1-ol (7.2%), trans piperitol (6.3%) and limonene (6.3%) prevailed in the EO of CG. The EO of CC revealed a rich composition in geranial (41.3%), neral (33%), myrcene (10.4%), and geraniol (6.6%). The biological tests have shown that these three EO induced 100% mortality of Anopheles gambiae to 1.1, 586.58 and 1549 µg•cm-2 respectively for CC, CS and CG. These effects are also illustrated by weak lethal concentration for 50% anopheles population (CC: 0.306; CS: 152.453 and CG: 568.327 µg•cm-2) in the same order of reactivity. The EO of CC appeared most active on two stocks (sensitive and resistant) of Anopheles gambiae.
ANTIBACTERIAL ACTIVITY EVALUATION OF ALLIUM SATIVUM ESSENTIAL OIL COMPARED TO DIFFERENT PSEUDOMONAS AERUGINOSA STRAINS IN EASTERN ALGERIA
SIHEM KHADRI(1), NAFISSA BOUTEFNOUCHET(1*), MAZZOUZ DEKHIL(2 3)
The chemical composition of essential oil extracted from Allium sativum bulbs harvested in the region of El Harrouch in Skikda was studied by gas chromatography coupled with mass spectrometry; six compounds were identified which predominant materials are: methyl allyl trisulfide (34.61%) and diallyl disulfide (31.65%). The antibacterial activity was tested on 52 clinical strains and one reference strain of Pseudomonas aeruginosa by both variants of the dilution method, the dilution method in liquid medium and the dilution method in solid medium. The results showed that the essential oil of Allium sativum has an inhibitory activity of growth compared to over 50% of strains tested with MICs relatively averages between 32 and 128 μg x mL-1.
SPECIATION OF HEAVY METALS IN SURFACE WATERS POLLUTED BY ANTHROPOGENIC ACTIVITIES
ELENA BÎRSAN(1*), CONSTANTIN LUCA(2)
In this work we present the results of a methodological research on the chemical speciation of heavy metals found in surface waters of an area polluted by mining activities (in the Western Carpathians). The surface water samples were collected in two seasons (summer and fall). Each time were performed in situ physical-chemical measurements (pH, Eh, conductivity, temperature) and analytical determination of total concentrations of some metals (manganese, copper, zinc, iron, cadmium) and anions (SO42-, Cl-, PO43-, NO3-). Analyze of chemical speciation of these metals was made using the PHREEQC program which allowed us to determine the distribution of studied elements. The concordance of the results obtained with this program with thermodynamic predictions arising from potential - pH equilibrium diagrams - Pourbaix type justify the compatibility between the program calculation and experimental data.
RESEARCHES ON THE DEVELOPMENT OF COCKTAILS WITH HIGH ANTIOXIDANT POTENTIAL <br/> RECHERCHES SUR LE DEVELOPPEMENT DES COCKTAILS AVEC UN POTENTIEL ANTIOXYDANT ELEVE
CAMELIA VIZIREANU(*), RODICA DINICA, FELICIA DIMA, DANIELA ISTRATI
The research aimed to study the influence of the extraction process on the content of antioxidant compounds present in four types of tea and establishing of the optimal conditions for preparation of cocktails in whose composition is combined the beneficial effect of foods rich in antioxidants and vitamins: green tea, exotic fruits, berries and honey. Content of antioxidants, protein, fiber, vitamins and minerals from unfermented tea is supplemented by high concentration of biological active compounds in fruits and honey used. A positive correlation between substances added with significant increase of antioxidant and nutritive potential has been observed. This study confirms that the synergistic action of green tea, fruits and honey allowed obtaining attractive drinks from sensorial point of view and compounds with high antioxidant potential content.
(Me<sub>4</sub>N)<sub>2</sub>SO<sub>4</sub>•4SnPh<sub>3</sub>NCS AND (Me<sub>2</sub>N)<sub>2</sub>CO•4SnPh<sub>3</sub>Cl SYNTHESIS AND SPECTROSCOPIC STUDIES
KOCHIKPA A.Y. OKIO, LIBASSE DIOP(*)
Two tetranuclear SnPh3 residue containing adducts have been synthesized and characterized by infrared and Mössbauer spectroscopies. The structure are both discrete, the sulphate anion and the tetramethyl NN’ urea (TMU) acting as tetracoordinating ligands, the environment around the tin IV centres being trans trigonal bipyramidal.
QUANTITATIVE EVALUATION OF SALT IN BAKERY PRODUCTS FOR ITS REDUCTION IN FOOD PRODUCTS <br/> EVALUATION QUANTITATIVE DU SEL DES PRODUITS DE PANIFICATION POUR SA REDUCTION DANS LES PRODUITS ALIMENTAIRES
ANA M. HOSSU(1*), MIHAELA F. MARIA(2), ALEXANDRU STOICA(3)
Salt is a vital nutrient necessary for proper functioning of the body, but a large amount of salt is a risk factor in increasing blood pressure, the main cause of cardiovascular disease. The aim of this paper is to determine the percentage of salt in some bakery products in order to reduce the salt intake and to prevent the diseases caused by excessive consumption of salt. For bakery products, determination of sodium chloride was carried out according to Romanian Standard SR 91:2007. Argentometric titration method was used, by titration in the presence of potassium chromate (Mohr method).
EFFECT OF THE INDUSTRIAL MILLING PROCESS ON THE RHEOLOGICAL BEHAVIOR OF DIFFERENT TYPES OF WHEAT FLOUR
IULIANA APRODU(1*), IULIANA BANU(1), GEORGETA STOENESCU(2), VIOLETA IONESCU(2)
In the milling process a large number of milling streams are obtained. These fractions are usually combined into a single composite product, but it is possible to select for blending certain fractions to obtaining different types of flours. In this work the rheological behavior, of the industrial flours obtained in different extraction levels was analyzed using Mixolab and Alveograph devices. Our results showed that the flour extraction rate is an important factor influencing rheological behavior. When by the milling process were obtained two types of flour, the flour with high ash content presented higher values of C3, C4 and C5 torques compared to flour with lower ash content. Therefore, the quality of the white flour obtained from wheat milling at different extraction levels highly depends on the flour fractions that are selected for blending.
HYDROCARBONS DIAGNOSTIC OF POLLUTED SOILS
HICHAM RHBAL(1*), SALAH SOUABI(1), MOHAMED SAFI(1), MOHAMED ARAD(2), ABDELKADER ANOUZLA(1)
Petroleum hydrocarbons are known as carcinogenic and may contaminate the environment (water, air and soil). In this study, a diagnostic of polluted soils by petroleum hydrocarbons is carried out in order to know the effect of their accumulation as well as their behavior in time. The aging factor, a source of significant changing in hydrocarbon behavior, is integrated on two sites of an industrial refinery as experimental samples. The first site is recently polluted by hydrocarbons while the second is a previously polluted site. The results indicate that the concentration of hydrocarbons on the surface of the first site is greater and remains stable in time, as for the second site, hydrocarbons concentration on the surface is also important and undergoes a weak reduction. At a depth of one meter hydrocarbons exist at a greater concentration. This shows that obstinate hydrocarbons are an environmental danger for fauna and flora.
INFLUENCE OF THERMIC TREATMENT ON TECHNOLOGICAL CHARACTERISTICS OF ADULT BEEF MEAT TENDERIZED WITH BROMELIN<br/> INFLUENCE DU TRAITEMENT THERMIQUE SUR LES CARACTERISTIQUES TECHNOLOGIQUES DE LA VIANDE DE BOEUF MATURE AVEC BROMÉLINE
DANIELA ISTRATI(*), CAMELIA VIZIREANU, FELICIA DIMA
Researches have been conducted on adult beef meat after 24 hours of slaughter. Proteolytic enzyme was added in different concentrations in the injection brine and then beef cuts were injected with different percentages of brine (10, 15% v/w). Effects generated by injecting samples of adult beef with bromelin were revealed after 24 – 48 hours of storage at 4 °C. For all treatments studied, pH values increased, the largest increases were observed in samples injected with the highest levels of bromelin and brine. Effect of exogenous proteolytic enzyme on the thermal losses of adult beef was influenced by enzymatic treatment conditions. Enzymatic tenderization with bromelin had a negative effect on water holding capacity of adult beef, causing a decrease compared with control samples. Increase of bromelin added brine, ageing time and the amount of brine injected decreased water holding capacity. Analytical data showed the tenderizing effect of bromelin, rigidity index values of the samples injected with bromelin being superior to control samples.