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Sibiescu D.,Technical University Gheorghe Asachi | Mita C.,Al. I. Cuza University | Vizitiu M.,Technical University Gheorghe Asachi | Crudu A.M.,National Research and Development Institute for Textiles and Leather
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

Over the last period of time silver was considerably studied due to its lower resistivity. In the field of materials science, silver was used in applications such as: microelectronics components of high - temperature superconductiviting materials, bactericidal coatings and others domains. This study presents the process of obtaining and characterization the new complexes of silver (I) with Nhydroxy- succinimide. In the process of obtaining the new complex compounds in aqous solution, first we have to look at conductometry and UV-Vis absorbtion spectroscopy in order to determine the molar ratio silver: N-hydroxysuccinimide and the stability constants. The obtained solid coordination compounds were characterized by elemental analysis, IR spectroscopy and also was investigated of their thermostability. The X-ray powder diffraction reflects that the complexes compounds of silver (I) with N-hydroxysuccinimide are amorphous. In our further studies we want to determine if the new synthetized compounds will present the same or improuved properties as in the above mentioned silver characteristics. © 2016 SPIE.


Crudu M.,National Research and Development Institute for Textiles and Leather | Sibiescu D.,Technical University Gheorghe Asachi | Gurau D.,National Research and Development Institute for Textiles and Leather | Constantinescu R.R.,National Research and Development Institute for Textiles and Leather | Vasilescu A.M.,National Research and Development Institute for Textiles and Leather
Revista de Chimie | Year: 2015

This paper presents the synthesis and study of three new complexes of iron (III) resulting from the interaction of FeCl3 with N-hydroxysuccinimide in central atom: ligand ratio of 1:1, 1:2 and 1:3. For the study of the new compounds, specific methods for characterisation of complex combinations in solid state were used (derivatography, IR spectroscopy, Mossbauer spectroscopy, X-ray diffraction). The compounds thus obtained (central atom in octahedral arrangement, with high spin and triclinic crystal system) were tested, yielding good results in leather processing technologies, with the aim of totally or partially replacing chromium salts in the tanning operation.


Mozir A.,University of Ljubljana | Strlic M.,University College London | Trafela T.,University of Ljubljana | Cigic I.K.,University of Ljubljana | And 3 more authors.
Applied Physics A: Materials Science and Processing | Year: 2011

Historic parchment is an extremely complex material, not only due to the various methods of production used and various past environmental histories of objects, but also due to its inhomogeneous structure. Many traditional methods of characterisation are empirical, but useful since they have gained recognition by the end-users. In this paper, we investigated the shrinkage temperature of collagen and the influence of lipids contained in parchment on the measurements. While the content of lipids does not seem to significantly affect shrinkage temperature measurements themselves, it strongly affects the decrease of shrinkage temperature of collagen during degradation, and thus its thermomechanical properties. This confirms the high importance of lipid peroxidation during degradation of parchment. While shrinkage temperature determination is a micro-destructive method, we also demonstrated that it is possible to determine this property using near infrared (NIR) spectroscopy based on partial least squares calibration. The root-mean square error of validation (RMSEV), obtained on a set of variously delipidised and degraded samples, was 7°C, so the method could be used for condition assessment or classification of historic objects. Using a set of 185 historic objects dating from 1200-1800, we also developed a method for non-destructive dating of parchment based on NIR spectroscopy using partial least squares regression (RMSEV=72 years), and successfully determined the correct age of a historic charter from the collection of Nationaal Archief, The Netherlands. © 2010 Springer-Verlag.


Marques C.,University of Aveiro | Ferreira J.M.F.,University of Aveiro | Andronescu E.,Polytechnic University of Bucharest | Ficai D.,Polytechnic University of Bucharest | And 2 more authors.
International Journal of Nanomedicine | Year: 2014

The purpose of this review is to present the most recent findings in bone tissue engineering. Special attention is given to multifunctional materials based on collagen and collagen-hydroxyapatite composites used for skin and bone cancer treatments. The multifunctionality of these materials was obtained by adding to the base regenerative grafts proper components, such as ferrites (magnetite being the most important representative), cytostatics (cisplatin, carboplatin, vincristine, methotrexate, paclitaxel, doxorubicin), silver nanoparticles, antibiotics (anthracyclines, geldanamycin), and/or analgesics (ibuprofen, fentanyl). The suitability of complex systems for the intended applications was systematically analyzed. The developmental possibilities of multifunctional materials with regenerative and curative roles (antitumoral as well as pain management) in the field of skin and bone cancer treatment are discussed. It is worth mentioning that better materials are likely to be developed by combining conventional and unconventional experimental strategies. © 2014 Marques et al.


Maria A.R.,Polytechnic University of Bucharest | Maria A.R.,National Research and Development Institute for Textiles and Leather
Proceedings of the 2015 7th International Conference on Electronics, Computers and Artificial Intelligence, ECAI 2015 | Year: 2015

The paper presents a mobile application for healthcare which process data from humidity and temperature sensors. The mobile app is based on cloud computing - SaaS (software as a service) cloud computing model. The scientific literature shows that wireless sensor network applications is used for healthcare, military, critical infrastructure monitoring, environment monitoring and manufacturing area. Recently Sensor-Cloud infrastructure become popular because can provide an open, flexible, and reconfigurable structure for monitoring and controlling applications [1]. Cloud computing is using internet technologies for offering elastic services. Cloud computing is based on dynamic acquirement of computing resources and support a variable workload. Scientific and engineering applications, data mining, gaming and social networking can benefit from cloud computing by storing research data in cloud. The advantage of network centric (iCloud-Apple) content is the accessibility of information from any site where users can connect to the Internet [2, 3]. The healthcare information stored on a cloud can be shared easily. The cloud computing infrastructure based on sensors can be used for deploying application which provides patients monitoring (moisture, temperature or blood pressure). The data is sent and stored in dedicated server for being analyzed later by doctors or caregivers. The advantages of sensor-cloud come also from using of PaaS (platform as a service) and IaaS (infrastructure as a service) models [4, 5]. © 2015 IEEE.


Maria A.R.,Polytechnic University of Bucharest | Maria A.R.,National Research and Development Institute for Textiles and Leather | Laurentiu D.,National Research and Development Institute for Textiles and Leather
Proceedings of the 2015 7th International Conference on Electronics, Computers and Artificial Intelligence, ECAI 2015 | Year: 2015

The paper presents a study regarding the possibility of integration of sensors and actuators in textiles structures. There is an increased interest on the application of wearable technology to monitor older adults and people with chronic conditions in the home. By using wearable devices for physiological monitoring could help in diagnosis or ongoing treatment of patients with neurological, cardiovascular and pulmonary diseases such as hypertension, dysrthymias and asthma. For portability and wearer comfort the monitoring devices must be integrated in wearable and flexible structures. The experimental part contents the evaluation of the textile structure in terms of conductivity and electrical resistivity. For the experimental part was used woven structure with conductive yarns on warp direction. By analyzing the resistivity values it can be concluded that for modeling of textile conductive structure with potential usage in area of wearable electronic device (sensors or actuators) it is very important the density of conductive wire in the structure. For analyzing the surface resistivity and conductivity it was taken into account the thickness of the material. The tests were performed according to SR EN 1149-1 standard. © 2015 IEEE.


Stelescu Daniela M.D.,National Research and Development Institute for Textiles and Leather | Gurau D.,National Research and Development Institute for Textiles and Leather | Craciun G.,National Institute for Laser, Plasma and Radiation Physics | Manaila E.,National Institute for Laser, Plasma and Radiation Physics
Leather and Footwear Journal | Year: 2013

The paper presents irradiation of thermoplastic elastomers based on ethylene-vinyl acetate (EVA) and poly(vinyl chloride) (PVC) plasticized with small ionizing radiation doses, in the presence of triallylisocyanurate (TAC), for the purpose of improving their characteristics. Results obtained from the study have shown that by irradiating blends of EVA/PVC in presence of TAC, new materials with improved properties have been obtained, as a result of crosslinking reactions and reorientation of sample particles under the influence of accelerated electrons. The optimal irradiation dose and the optimal TAC concentration can be chosen depending on the composition of each blend and on the applications of the final product.


Stelescu M.D.,National Research and Development Institute for Textiles and Leather | Georgescu M.,National Research and Development Institute for Textiles and Leather | Manaila E.,National Institute for Laser, Plasma and Radiation Physics
Proceedings of the 3rd International Conference on Advanced Materials and Systems, ICAMS 2010 | Year: 2010

This paper presents a study on the influence of the vulcanization method - of the crosslinking mechanism - on the characteristics of a natural rubber blend. The tested methods have been: (1) with sulphur and vulcanization accelerators (the most used), (2) with benzoil peroxide, (3) with accelerated electrons (EA), (4) with EA in the presence of a polyfunctional monomer - trimethylopropane trimeftacrylate (TMPT). Crosslinking of elastomers with the help of ionizing radiations is made without heating and in the absence of vulcanization agents. The chemistry of the process is based on microradical formation from elastomer chains, which recombine, causing structuring. The reaction mechanism is similar to that of the peroxide method, but in this case, the initiation of the reaction is due to the action of accelerated electrons. Crosslinking with sulphur and accelerators is made by ionic mechanism when sulphur bridges form between rubber macromolecules. The obtained results indicate that hardness, elasticity and 100% module of blends vulcanized with sulphur are much lower than those vulcanized with peroxide: instead they have higher values for tensile strength, tear strength and breaking elongation. The optimal dose necessary for crosslinking decreases to 10 Mrad from 20 Mrad using 6 phr TMPT. Blends crosslinked with EA in the presence of TMPT present higher values of tear strength, have good values of permanent elongation - similar to those obtained through the other methods - indicating an efficient crosslinking, and tensile strength, breaking elongation, hardness, elasticity and 100% module have values similar to those obtained through the other 2 vulcanization methods.


Ficai A.,Polytechnic University of Bucharest | Andronescu E.,Polytechnic University of Bucharest | Trandafir V.,National Research and Development Institute for Textiles and Leather | Ghitulica C.,Polytechnic University of Bucharest | Voicu G.,Polytechnic University of Bucharest
Materials Letters | Year: 2010

The purpose of this study was to obtain and characterize the oriented collagen/hydroxyapatite (COLL/HA) composite materials, using different kind of electric field. The orientation process takes place due to the dipolar collagen structure. The collagen molecules are electrically charged and can become oriented if an electric field is applied. The composites were obtained by the co-precipitation method starting from collagen gel and hydroxyapatite precursor. The mineralized collagen gel was introduced in an electric field for 1 h, frozen and lyophilized. In order to study the orientation process parameters, two types of electric fields were tested: pulsatory and superposed (both direct and pulsatory). The obtained materials were characterized by XRD, FTIR and SEM. Best results in what it concerns the oriented character of the microstructures, as resulted from SEM images, were obtained for a pulsatory field of 0.93 V/cm, the presence of the direct electric field component decreasing the orientation degree. The average orientation degree, calculated at the magnification of 1000× was about 95%. © 2009 Elsevier B.V. All rights reserved.


Aileni R.M.,Polytechnic University of Bucharest | Surdu L.,National Research and Development Institute for Textiles and Leather
2014 International Symposium on Fundamentals of Electrical Engineering, ISFEE 2014 | Year: 2015

This paper presents several aspects regarding the surface preparation for obtaining wearable devices (sensors embedded in the textile structure). For the electronic devices (OLED, PV, sensors and actuators) deposition it is very important to have a compact woven structure with antistatic, hydrophobic and oleophobic character. For this purpose, nanocoating treatments for the textile woven structure by using plasma nanotechnologies have been developed. © 2014 IEEE.

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