Steliana Rodino

BIODIESEL PRODUCTION USING CALCIUM-BASED SOLID CATALYSTS

The present work describes the study of obtaining new catalysts from affordable raw materials, respectively two different types of antacid drugs and egg shells. It was also studied their efficiency in heterogeneous catalysis process. In order to determine the optimal reaction conditions, the catalysts were activated in a thermal annealing oven following to be tested the different conditions of their usage: concentration of catalyst, activation temperature, reaction time, and number of reutilizations. Aiming to standardize the process, the samples used were measured to exactly 20 mL methanol and 50 mL safflower crude oil. All the catalysts tested had high yields of over 86%; the best performance was recorded in case of a catalyst derived from pills containing magnesium carbonate and calcium (92%) in a period of about 6 hours. The biodiesel obtained was analyzed qualitatively, especially for the presence of calcium ions in solution. The catalysts revealed a good potential for utilization in biodiesel production.

STUDIES REGARDING THE CULTIVATION OF SAFFLOWER IN SOUTHERN ROMANIA

The aim of the present study was reintroducing the cultivation of safflower (Carthamus tinctorius L, fam. Compasitae), studying the adaptability of this species to the climatic conditions in the southern Romania (Giurgiu County) and providing raw material for obtaining biofuel. The culture was established on agricultural land belonging to the village of Roata de Jos, Giurgiu County, located in Gavanu–Burdea plain, part of the Romanian Plain, Dambovnicului Plain subdivision. Sowing was realised in October 2011, respecting the planting scheme: 50 cm between rows, 18 cm between plant on a row, using 21 kgs seeds/ ha, purity = 98% and germination = 80%, to ensure an appropriate density at harvest of 200,000 plants/ ha. Average values obtained on quantitative characters of safflower showed that average plant height is 72.3 cm, the degree of branching = 12.2 (with ramifications of I and II degree), the average calathid number per plant 11.2, average number of achenes per calathid 21, average number of achenes per plant 230.

IN SILICO MOLECULAR DYNAMICS OF THE PEPTIDE WAMP-1A

Humans, animals and plants are constantly subject to pathogen microorganisms attack. The biggest threat to organisms is represented by fungal attack. Permanently seeking for new solutions to prevent and treatment of diseases caused by fungi, the researchers have turned their attention to antimicrobial peptides. These are produced by a large variety of organisms. The plans are the most important source of peptides having antifungal properties. In the present article is revealed a study of the molecular dynamics of such a peptide, namely the antimicrobial peptide WAMP-1a. Since the conformational structure of the peptide sequence is directly related to its activity, the dynamic parameters were analysed and were identified the amino acid residues that show the largest flexibility.

A Study of the Antioxidant Effect of Flavonic Compounds for Preventing Lipid Oxidation by Using Fluorescence Spectroscopy

In this paper a study of the effect of flavonic compounds in preventing and/or reducing the membrane lipid oxidation due to free radical attack was performed by using fluorescence spectroscopy techniques. Lipid peroxidation was investigated by using liposomes-artificial membrane models, which were prepared by lipid hydration method. Their oxidation was performed with a 15-W ultraviolet germicidal lamp having wavelength radiation 253.7 nm. In the first series of experiments, the protective effect of two synthetic antioxidants (quercetin and caffeic acid) against free radicals was monitored, while in the second series two 70% hydroalcoholic extracts from blueberry and blackcurrant leaves was used. It was determined that natural antioxidants have a much higher antioxidant power against free radicals than synthetic compounds but they degrade after two hours of oxidation. Liposomes are better protected when using natural antioxidants, but their degradation is completed more quickly, than in the case of synthetic antioxidants.

Ontological model for the evaluation of the impact of nanoparticles on the human cell morphology

The development of in silico methods with application in scientific research is in full progress. They have the advantage of being modest consumers of material resources and time and, also, of being easy to be used by researchers from various field of specialization. The research work described in this paper has pursued building an ontological model for the evaluation of the impact of nanoparticle on the human cell. This model can be used to determine the inflammatory and cytotoxic effects of nanomaterials on human cells by complements and refining of the data achieved by well–known laboratory techniques. Keyword: ontology, modelling, citotoxicity, nanoparticles.

Evaluation of some yeast strains to obtain forage biomass.

The present paper presents the screening of two yeast strains, for the obtainment of forage biomass from grape marc diffusion solution supplemented with wine yeast extract. The yeast strains used were Saccharomyces ellipsoideus originating from alcoholic fermentation, and a strain of Rhodotorula sp. Protein biosynthesis was monitored by determining the following parameters: alcohol concentration at the beginning and end of the process, the optical density of the culture medium, the residual sugar, and the wet and dry biomass. Better results were obtained for Rhodotorula sp. strain, and this can be explained by the presence of glucose which is a much better tolerated carbon source than the ethanol.

COMPARATIVE STUDY OF PHENOLIC CONTENT OF SOME PLANT EXTRACTS

The aim of the present study was to draw a comparative analysis of the content in flavones and polyphenols of the hydro alcoholic extracts obtained from two medicinal plants, namely artichoke (leaves) and respectively, licorice (root) according to the origin of the vegetal material and the method used in the preparation of the extracts. The plants used in the experiments are two indigenous medicinal plants belonging to wild and cultivated flora in Romania. Artichocke (Cynara scolymus) and licorice (Glycyrrhiza glabra) were purchased from three local companies trading medicinal plants: Plafar, Vitaplant and Franco Impex. It was evaluated the composition of the extracts in terms of the content of polyphenolic compounds expressed in caffeic acid and flavone compounds content expressed in rutin. Plant extracts were obtained by two different methods of preparation: ultrasonation and maceration with intermittent shaking.