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Ficai M.,National Research and Development Institute for Textiles and Leather Division | Stan A.,National Institute of Aerospace Research Elie Carafoli | Georgescu M.,National Research and Development Institute for Textiles and Leather Division | Vilsan M.,National Research and Development Institute for Textiles and Leather Division
Proceedings of the 3rd International Conference on Advanced Materials and Systems, ICAMS 2010 | Year: 2010

In the competition of polymer compounds new improvements have recently been developed in the synthesis of elastomers and polyolefins, in their processing in the presence of high-performance reinforcing materials, with preset properties. Due to the fact that styrene-butadiene elastomer does not crystallize by stretching, in the absence of active charges most often it exhibits unsatisfactory properties. Polymer structures based on styrene-butadiene rubber have been done on a laboratory roll with heating possibility, Brabender type, by incorporating different types and quantities of reinforcing agents in the form of grains or powders with nano structure and chemically activated surfaces as well as by using numerous auxiliary materials with well-determined role in influencing properties of finished products or price. From the blend obtained on the roll samples of various sizes have been taken and vulcanized in the form of plates, in the electric press at time values established after rheological testing. As a result of physical-mechanical testing, it could be noticed that the presence of reinforcing agents induces significant improvements of physical-mechanical characteristics of polymer structures, compared to reference materials, and technological processability of the new materials being much improved (density of compounds increases proportionally to the increase of charge content, the values of hardness vary in considerable proportions in relation to reference values (from 42 to 63°Sh A) depending on the type of charge used to make the compounds). These data are confirmed in all types used.


Lancranjan I.,National Institute of Aerospace Research Elie Carafoli | Miclos S.,Romanian National Institute for Optoelectronics | Savastru D.,Romanian National Institute for Optoelectronics
Journal of Optoelectronics and Advanced Materials | Year: 2011

This paper is the first of a series on numerical simulation of solid state lasers operated in passive optical Q-switching regime and their applications in various fields. The main purpose of this series is to present the results obtained using numerical analysis as a tool for properly designing solid state lasers, function of application for which these are dedicated since the passive optical Q-switching regime is a large scale used technique. In this paper the numerical simulation results obtained for a passive optical Q-switched Nd:YAG laser of a smaller volume dedicated to ~ 5ns FWHM time duration and over 200 mJ energy pulse generation. The main purpose of the performed theoretical analysis consists of a better understanding of Nd:YAG laser q-switching process itself and of its possible applications in range finding, guiding, materials micro processing and nonlinear optics.


Lancranjan I.,National Institute of Aerospace Research Elie Carafoli | Miclosa S.,Romanian National Institute for Optoelectronics | Savastrua D.,Romanian National Institute for Optoelectronics
Journal of Optoelectronics and Advanced Materials | Year: 2010

This paper is the first part of a series pointing to numerical simulation of various aspects of distributed feedback fiber laser sensors and their applications. The developed numerical analysis has the scope of a better understanding of DFB-FL itself and of its interaction with environment in order to be operated as a sensor. The aeronautical applications of DFL-FL sensors constitute the main field of numerical simulations and analysis field.


Ficai M.,National Research and Development Institute for Textiles and Leather | Stan A.,National Institute of Aerospace Research Elie Carafoli | Stefan A.,National Institute of Aerospace Research Elie Carafoli | Georgescu M.,National Research and Development Institute for Textiles and Leather | Vilsan M.,National Research and Development Institute for Textiles and Leather
Leather and Footwear Journal | Year: 2010

In this paper a multitude of polymer blends on a Brabender laboratory roll in the presence of many auxiliary materials with well-determined role in influencing the properties of the finished product. Upon the analysis of physical-mechanical values, it can be noticed that the density of polymer structures increases proportionally with filler quantity, while properties such as elasticity decrease proportionally with it. Due to the fact that butadiene-co-acrylonitrile rubber is not crystallized by stretching, in the absence of reinforcing agents, it often has unsatisfactory physical-mechanical properties. In the presence of active reinforcing agents of nano sizes, due to the large specific surface, the interactions developed between elastomer and reinforcing agents are maximized leading to compatibilization. Based on results obtained from experiments, it can be stated that polymer structures based on butadiene-co-acrylonitrile rubber are resistant to immersion in isooctane, in strong acids and bases, in mineral oils and organic plasticizers. The obtained blends have optimal characteristics for use in the field of vulcanized footwear for general use, in the food industry, for gaskets, and due to their resistance to immersion in isooctane, acids and bases, they can be used in aggressive environments.

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