GEOMETRICAL METHOD AND DEVICE USED TO DRAW THE RESONANCE GRAPHICS FOR A RLC SERIES CIRCUIT IN ALTERNATIVE CURRENT

Ioan LUMINOSU, Nicolina POP, Viorel CHIRITOIU

Abstract. The paper form and develop the student’s skills and abilities to measure indices of the alternating current (AC) in permanent regime. It develops experimental data-processing capacity by calculating reactance, impedance, AC power and plotting the resonance curve. It develops the ability to use units of measurement of electrical quantities as: impedance, reactance, active and reactive power. It develops the capacity of observation by highlighting side effects occurring in achieving RLC series resonance circuit voltage in (AC). Students determine the resonance phenomenon of RLC series AC circuit is characterized by:

equal absolute values of tension on reactive circuit elements;

maximum intensity of current through the circuit;

equality of inductive reactance and capacitive reactance;

circuit impedance is equal to its ohmic resistance;

active power equals apparent power;

circuit terminal voltage is equal with ohmic voltage. Questions are meant to end pre-enhance knowledge formed by performing the work.

Keywords: resistance, impedance, capacitor, reactance, Ohm’s law, phasor diagrams.

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ESSENTIAL OIL COMPOSITION AND ANTIMICROBIAL ACTIVITY OF ARTEMISIA HERBA-ALBA ASSO GROWN IN MOROCCO

B. IMELOUANE, A. El BACHIRI, M. ANKIT, K. KHEDID, J.P. WATHELET, H. AMHAMDI

Abstract: Volatile components of Artemisia herba-alba Asso essential oil obtained by hydrodistillation growing in eastern Morocco (Taforalt) were investigated by GC/FID and GC-MS. The major components were found to be camphor (43.07%), camphene (7.2%), 1,8-cineole (7.08%), filifolone (7.04%), borneol (4.88%), and bornyl acetate (3,79%).The essential oil has been tested for antimicrobial activity against Gram-negative and Gram-positive bacteria. Inhibition of growth was tested by the agar diffusion method. The minimal Inhibitory Concentration (MIC) was determined by the method of microtitration assay.

Keywords: essential oil, Artemisia herba-alba, antimicrobial activity, Morocco.

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A FLOW CYTOMETRIC COMPARISON OF TWO GLIOBLASTOMA CELL LINES

Constantin DANIEL, Liana TOMA

Abstract. Glioblastoma is the most common malignant neoplasm that occurs in the central nervous system in humans, it is very difficult to treat despite advanced diagnostic, imaging and surgical techniques. In recent decades, great efforts have been made to elucidate the cellular and molecular mechanisms of this disease. However, not much progress has been made due to the fact that the brain tumor is composed of heterogeneous populations of cells, many of them resistant to chemotherapy. It is clear that researchers need many in vitro test models (cell lines) in order to better understand and treat this disease. The purpose of this study is to compare in terms of the amount of DNA and cell cycle, a malignant glioma cell line, T11 obtained at INCDSB 1, with a stabilized glioblastoma cell line acquired from a reference center (U87 line). The flow cytometry analysis determines whether the cell cycle and DNA content of our local cell line, T11, are similar to those of the U87 line used worldwide.Our results indicate that are no significant differences between the two cell line regarding size, granularity, DNA content and cell cycle.

Keywords: glioblastoma, cell cycle, flow cytometry.

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DECOMPOSITION OF SPATIAL TIME SERIES, THE”WHITE NOISE” IN POTATO PRODUCING

Budaházy GYÖRGY

Abstract. The aim of this paper is to present a method of spatial time series analysis. The annual data of potato yield growth at county level in Hungary are rank ordered by the mean yield growth and the data which contains ten time period are analyzed by the help of sophisticated time series techniques.

Keywords: potato yield growth, time series analysis, white noise, county level.

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BIOCHEMICAL CHANGES IN LUCERNE ATTACKED BY LONGHORN BEETLE AND ROOT ROT

Dimitriya S. PETKOVA, Evgeniya D. ZHEKOVA, Anna V. ILIEVA, Iliana I. IVANOVA

Abstract. Eight alfalfa genotypes were investigated at IASS “Obraztsov chiflik”–Rousse during the period 2006–2009. The objective of the study was investigation of biochemical changes in alfalfa roots, attacked by lucerne longhorn beetle (Plagionotus floralis Pall.) and root rot. Biochemical analysis of healthy roots, roots damaged by larvae of longhorn beetle, roots attacked by root rot and green mass were made. The healthy status of roots was evaluated according to the scale of Lyubenets and Shtukina (1968). A moderate negative correlation was determined between total phenols and sugars in plants damaged by longhorn beetle. The content of proteins, fiber, calcium, magnesium and total phenols in plants damaged by longhorn beetle and root rot increased compared to healthy ones and a decrease of sugars was observed. The highest number of healthy plants and high productivity were registered in Synthetic population (SP) N 7 and it could be appropriate in selection for the purposes of breeding.

Keywords: alfalfa, Plagionotus floralis, root rot, biochemistry

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PHYSIOLOGICAL REACTION OF REGIONAL VARIETIES COMMON WHEAT UNDER CONDITIONS OF ECOLOGICAL STRESS

Siika PAVLOVA, Vesselin DOCHEV

Abstract. During the period 2005–2007 at the experimental fields of IASS “Obraztsov chiflik” a provocative fiеld experiment was conducted with simulated drought of 20 varieties winter common wheat. The varieties were cultivated under conditions of moisture providing (control) and simulated drought during the most critical phase of ontogenetic development–flowering–formation of reproductive organs via shelter construction. Resistance to soil and atmospheric drought was investigated also and the vigor of seeds via electrical conductivity of seed membranes–conductormetric. The results of the investigation showed specific features, as depending on the simulated drought, so – on the meteorological variations during ontogenesis. The stress soil and atmospheric moisture during the spring vegetation decreased the resistance to heat of the varieties Todora, Enola and Ludogorie. Under conditions of soil and atmospheric drought the same varieties showed high resistance to heat, also and the varieties Prelom, Kristi, Pobeda, Pryaspa, Preslav. The vigor of seeds decreased as under conditions of stress water providing, so under conditions of soil and atmospheric drought. Increasing the strength of the stressor–soil and atmospheric drought, the vigor of seeds suddenly decreased.

Keywords: wheat, drought resistance, resistance to heat

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APPLICATION OF MOLECULAR DYNAMICS SIMULATIONS METHOD FOR PEPTIDE 1ED3

Marian BUŢU, Alina BUŢU

Abstract. Molecular dynamics simulations method gives the possibility of studying and understanding the relationships between the structure and the function of biological molecules. Once with increasing the computing power, this method became a very powerful tool to predict the quantities that cannot be measured directly or whose accurate experimental data are difficult to obtain. It can provide a microscopic image of system which may explain macroscopic behavior of the biomolecular system. Molecular dynamics simulation method can be applied to: sampling configuration space, description of the system at equilibrium, calculating dynamics and kinetics of system. The peptide MTF–E is a fragment of 13 residues (residues 29–41) from rat ATPase 6. This peptide is recognized by Major Histocompatibility Complex class I (MHC I). Here we examine the conformational properties of the peptide using molecular dynamics simulation method. Trajectory analysis indicated that the peptide adopts a certain conformation of the backbone.

Keywords: molecular dynamics, simulation, biological molecules, peptide, computational methods.

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GROWTH, DEVELOPMENT AND YELD OF MAIZE HYBRIDS IN VARIOUS CONFIGURATIONS AND DENSITIES OF SOWING UNDER EXTREME CLIMATIC CONDITIONS OF OBRAZTSOV CHIFLIK–ROUSSE I. ACCUMULATION OF BIOMASS

 Lubomir IVANOV, Siika PAVLOVA, Ivelina VENKOVA

Abstract. During the period 2007– 2009 a field experiment was conducted at the IASS “Obraztsov chiflik”– Rousse for determination of the accumulation of dry matter in three maize hybrids according to FAO: Clarica–300; Evelina–400 and PR35P12–500. The experiment was conducted in densities 4000, 5000, 6000 and 7000 plants per a da in two configurations of sowing–square and rectangular. The results showed that the tested hybrids accumulated various quantity biomasses depending on the climatic conditions, density and the configuration of the nutritive area. Under conditions of extreme soil and atmospheric drought, hybrid PR35P12 accumulated the highest quality of biomass in square configurations 50/50 cm and 44.7/44.7 cm and in the rectangular–70/35.7 cm and 70/28.6 cm, and hybrid Clarica–in the densities of 50/50 cm and 70/35.7 cm. Only hybrid Evelina accumulated more dry matter in the rectangular configurations of 70/35.7 cm and 70/28.6 cm.

Keywords: dry matter, density, square and rectangular configurations

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APPLICATION OF MODERN HERBICIDES FOR WEED CONTROL IN SPRING RAPE (Brassica napus)

Svetlana P. STOYANOVA

Abstract. A field trial with spring rape, JURA variety was conducted during the period 2007–2008 at the experimental fields of IASS “Obraztsov chiflik”–Rousse. The objective was determination of the efficiency of some herbicides applied alone and in combination in optimal doses. The herbicide napropamide, applied after sowing before emergence in dose of 157.5g/da a.s., decreased grass weed density 100% and the density of broad–leaved weeds by 89% and 84%, respectively. The herbicides fluazifop–p–butil and quisalofop–p–ethyl applied in doses of 22.5g/da a.s. and 7.5g/da a.s., were effective against the grass weeds as their density was decreased up to 98%, and against the broad-leaved weeds the percentage of efficiency was up to 83%. The herbicide napropamide applied in a system with herbicides fluazifop–p–butil or quisalofop-p-ethyl showed excellent herbicidal efficiency against the annual grass weeds (to 100%) and broad–leaved weeds (to 93%).

Keywords: spring rape, weeds, herbicides, efficiency, selectivity

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RISK ANALYSIS AND ADOPTION OF DECISIONS BY USING PALISADE SOFTWARE PACKAGE

Vasile CRISTIAN

Abstract: The rising volume of information conveyed and the speed of work are becoming increasingly necessary applications and devices to meet these requirements. Thus, in the actual society of knowledge, the impact of the new informational technologies was extended even in an important domain of human activity: the adoption of decisions. Consequently, the necessity of objecting at the selection process of the most favorable decision lead to the extension of the usage of information technology also in the conceptual phase. The decision tools suite (DTS) and the expert systems have the answer for the computer science workers at the needs of the deciders, used especially in the case of the decisions adopted in conditions of risk or uncertainty. The PALISADE package of programmers is a support system of decisions, which overlaps the processor tables, increasing the possibility of usage, especially for simulation problems, calculating the risk, building decision trees etc.

Keywords: computerization, simulation, palisade, risk, decision, analysis

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