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Ivana S.,University of Bucharest | Ivana S.,Asclepius 2008 Research and Development Center | Tuluca E.,Institute of Food Chemistry | Dinu C.P.,Carol Davila University of Medicine and Pharmacy | Dinu C.P.,Scientific Research Center for Defense and Ecology
Cellulose Chemistry and Technology | Year: 2013

The paper presents the results concerning the modifications in the sugar composition resulted from lignocellulosic substrates subjected to the action of lignolytic fungi: Pleurotus ostreatus and Phanerochaete chrysosporium. The substrates used were formed by various mixtures of corn cobs and oak tree leaves, oak tree sawdust and oak tree leaves, and oak tree bark - oak tree leaves, all in ratios of 2:1 (marked as mixtures I, II and III). The evaluation of the sugar composition of the substrates biodegraded by the above-mentioned fungi, for 30 days, was performed after hydrolysis, using IN sulfuric acid at 120 °C, for one hour, followed by sodium carbonate treatment until a pH of 5.8 was reached. The quantitative determinations were performed through gas chromatography. The gathered data showed that the highest degree of the heteropolysaccharide degradation corresponded to Pleurotus ostreatus, while the fungus Phanerochaete chrysosporium cultivated under the same conditions degraded carbohydrates at a lower level. Also, a large consumption of pentoses was recorded, evaluated through the variation of the xylose amounts, which rapidly decreased in case of the Pleurotus ostreatus microorganism, in comparison with the substrate inoculated by Phanerochaete chrysosporium. Similarly, the hexoses consumption levels (mainly of glucose) were quite modest in the case of Pleurotus ostreatus and quite significant for Phanerochaete chrysosporium. Source

Petre R.,Scientific Research Center for Defense and Ecology | Hubca G.,Polytechnic University of Bucharest
UPB Scientific Bulletin, Series B: Chemistry and Materials Science | Year: 2013

The main results of the present study reside in the development of an original laboratory technology for the luminol synthesis and its intermediaries: α-nitronaphthalene, 3-nitrophthalic acid, and 3-nitrophthalhydrazide. The total chromatograms and the mass spectra have been compared with a Merck reference luminol. The advantages of this technology are: the synthesized luminol presents a higher purity against the standard and is costly available. Source

Yan Q.-L.,Tel Aviv University | Trzcinski W.A.,Military University of Technology | Cudzilo S.,Military University of Technology | Paszula J.,Military University of Technology | And 4 more authors.
Combustion and Flame | Year: 2016

Conceptually new cylindrical charges enveloped by Al foils have been designed and their thermobaric effects, due to simultaneous fragmentation and combustion of the foils, have been experimentally determined. The fragmentation processes of Al foil was supported by numerical simulations. It has been shown that the quasistatic pressures (QSP) for phlegmatized RDX (RDXph) enveloped with Al-coated plastic foils are higher than that of the pure RDXph, due to combustion of these foil fragments in a thermobaric explosion. The QSP generated by Al-Ni foils enveloping RDXph was found to be much lower than performance of other foils, possibly due to relatively inert nature of Ni. In a small detonation chamber, the charges of RDXph/Al foil (RDXph/Alf) produced even higher experimental maximum peak pressure (δpmax) than the charges that contained Al powder (Alp). In a closed bunker, the impulse amplitudes of RDXph enveloped by aluminized polyethylene (Al-PE) foils and RDXph enveloped by 100μm Alf (Alf100) charges are much lower than those of the other charges. It was found that the charges enveloped by Al foils have even larger δpmax than that of RDXph/Alp charges, indicating that the Alf could generate better blast performances than the Alp. The simulations indicate that the observed blast enhancement is dependent not on the thickness, but on the size of surrounding space. The thermobaric fire-ball generated by 40g RDX/Alf charge could sustain combustion up to 40ms, reaching a maximum radius of about 2.4m. © 2016 The Combustion Institute. Source

Pirvu C.,University of Galati | Badea S.,Scientific Research Center for Defense and Ecology | Deleanu L.,University of Galati
Applied Mechanics and Materials | Year: 2014

This paper presents a simulation of a bullet impact on a plate, all materials being assigned to a bilinear isotropic hardening model. The developed model takes into account the yield and fracture limits of both involved materials for the bullet and the plate one. The model was developed with the help of Ansys 14.5 and could be used to establish a theoretical value of the plate thickness that will offer protection to the bullet penetration in order to minimize the number of laboratory tests for evaluating the plate resistance. The authors presented the influence of impact velocity of the bullet. The bullet velocity just reaching the plate is an essential parameter influencing the plate integrity. Also, the authors established a correlation between the evolution of the theoretical maximum von Mises stresses and the stages taking place during the impact. © (2014) Trans Tech Publications, Switzerland. Source

Dulgheriu I.,Technical University Gheorghe Asachi | Avadanei M.,Technical University Gheorghe Asachi | Badea S.,Scientific Research Center for Defense and Ecology | Safta I.,Scientific Research Center for Defense and Ecology
Industria Textila | Year: 2012

A great potential direction of development is the structures design for ballistic protection. Significant progress achieved by scientists, designers and manufacturers of advanced materials, used for individual ballistic protection, allowed, at this level, the competition revival, between projectile and armor. The paper presents the way of achieving and testing 6 variants of ballistic packages made of Kevlar laminate fabric, Kevlar XP and metallic fabric, within the Testing Laboratory for Ballistic and Pyrotechnic Protection of the Scientific Research Center for CBRN Defense and Ecology. Source

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