Studia Universitatis Moldaviae. Stiinte reale si ale naturii

3-9

Authors: Aurelia CRIVOI, Iurie BACALOV, Elena CHIRIŢA, Iulian PARA, Ilona POZDNEACOVA, Adriana DRUŢA

Bee products are a rich source of calories and an excellent source of nutrients containing a rich variety of vitamins. It also provides or complements mechanisms that naturally occur in an organism. Taking into account the benefits of bee products, they are consumed with great confidence in food.

15-18

Authors: Lidia COJOCARI, Aurelia CRIVOI, Ana TABAC

This article analyzes the causes of stress in pre-school children and its annihilation ways. Eventually , the children may have to be morally prepared for stressful situations because we cannot completely protect them from any negative situations and responsibilities.

24-29

Authors: Valentina BULIMAGA, Liliana ZOSIM, Maria PISOVA, Veaceslav REVA

Selenium-containing (Se-EPS) and EPS from Spirulina platensis cyanobacterium grown on the nutritive medium with and without selenite supplementation were obtained. The partially purified extracts (after removal of the proteins fraction) were subjected to HPLC separation on the Toyo-Pearl HW40F column. The UV spectra of the exopoly¬sac-charide preparations have been scanned and the technological scheme for obtaining of Se-EPZ produced by Spirulina platensis has been developed.

35-40

Authors: Petru CUZA

Was studied the specific distribution of the descendants of common oak (Quercus robur) by category of heights in autumn and spring sowing. It has been demonstrated that at the individual growing stage of the saplings, in the absence of competition between copies, the distribution of oak numbers by height classes, both in autumn and spring crops, is approaching the law of normal distribution. After realizing the massive state of the oak frequency curve in relation to the height, it has a right asymmetry. This demonstrates that in the competition for solar energy and mineral elements in the soil, a part of the genotypes, with superior hereditary attributes, growing fast inside tend to occupy dominant positions, embarrassing the growth of the least developed. In this way natural variability is reduced caused mainly by genetic diversity, as a result of the growing influence increasingly pronounced of environmental factors, especially trophic ones (mineral nutrition and illumination) on growth in oak height.

47-51

Authors: Алла ГЛАДКАЯ

The R. rhaponticum L root extract exhibits fungicidal and activator properties in the control of Sphaerotheca fuliginea on the family Cucurbitacea seedlings. The addition of microelements can make the composition more profitable. The combination of an extract R with a microelement Cu2 + increases the medical properties, and with microelements (Zn2+, Fe2+, Mg2+, B3+) enhances the prophylactic properties of the preparations.

57-60

Authors: Елена ПЕЛЯХ, Василий ЧОБАНУ

New hybrids of mint were obtained as a result of distinct hybridization and complicated selection in Laboratory of Plant Biochemistry of Moldavian State University. In crossing were involved species, ecotypes, chemical rases and natural populations from different geographical regions as a parental forms. The character of divergence depend on the origin of hybrids and on their genotypical specificities. Comparative studies of strains of mint revealed advantage some of hybrid thanks to high yield of oil, great amount of carvon, linalool, mentol etc.

68-77

Authors: Maria GONȚA, Vera MATVEEVICI, Viorica IAMBARȚEV, Larisa MOCANU, Gheorghe DUCA

It has been studied the process of diminishing the concentration of emollient 2,2-dihydroxymethyl proponic acid (DMPA) in the presence of the active orange textile dye (AP). It has been found that the effect of removing the organic components of the dye and thickeners mixture is increased by applying the electrofloating or electrofloatocoagulation method and the removal effect decreases when is applied the coagulation method. Also, it was found that the simulated systems which are low concentrations of dye AP (100,0 mg/L) and the con-cen¬tra¬tions of the thickener are up 20,0 to 80,0 mg/L) shall be treated by the combination of the electrofloatocoagulation and adsorption methods. If it is increasing the concentration of organic compounds, they are purified by a combination of electrofloatocoagulation and oxidation methods.

86-92

Authors: Iolanta BALAN

The Pseudo Jahn-Teller Effect (PJTE) is used to rationalize structural changes in the redox processes of NH3 and CH3 molecules by means of analyzing the changes in their symmetry and energy gaps between the ground and lowest excited electronic states that control their PJTE coupling along the distortion coordinates. The numerical values of the vibronic coupling constants were estimated by means of fitting the solutions of the secular equations to the ab initio calculated energy profiles. It is shown that oxidation of NH3 molecule by removing an electron from the high occupied molecular orbital (HOMO) leads to the suppression of the PJTE and to restoration of planar nuclear configuration. Reduction of CH3 molecule enhances the PJTE, leading to its pyramidalization.

97-106

Authors: Vasile RUSU

It was performed analysis of the characteristics of the electric double layer (EDL) close to the basal surface and edge surface of H-montmorillonite and pillared Al-montmorillonite. The thickness of compact layer (Stern layer) was esti¬mated on the basis of ions dimensions proposed by Marcus. For H-montmorillonite, the dielectric constant for Stern layer is about rI ≈ 7,2 for EDL in the proximity of the basal surface and about rI ≈ 8,5 for EDL in the proximity of the edge surface, while the surface potential 0 for these surfaces is about -0,083 ÷ -0,084 V. For pillared Al-montmorillonite, the corresponding dielectric constants for these surfaces are rI ≈ 9 and rI ≈ 12, and the the surface potential -0,121 ÷ -0,117 V in accordance with values established from Gouy-Chapman model. The electrical capacity of compact layer was estimated on the basis of established characteristics (δ, rI) and was established the increasing of electrical capacity as the thickness of compact layer is decreasing.

116-119

Authors: Vladislav BLONSCHI, Viorica GLADCHI

This paper contain the results of multi-annual study on the optimization of inhibition capacity determination, obtained after statistical processing of empirical data from 2008-2017. Thereafter of statistical processing of multi-annual data, it was proposed the average value of fading speed of PNDMA indicator in distilled water, that optimize computation of the inhibition capacity of waters.