This article aims to provide a longitudinal presentation of developments in Romanian accounting d... more This article aims to provide a longitudinal presentation of developments in Romanian accounting during the 20th century and to propose a neo-institutional explanation of this evolution.
2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM), 2014
ABSTRACT The aim of this paper is to introduce - by general analytical nonlinear and then optimal... more ABSTRACT The aim of this paper is to introduce - by general analytical nonlinear and then optimal design with vector control a hybrid electric and electric vehicles (HEV/EV) electric propulsion system for 50/100 kW, 1350-7000 rpm (600 Nm peak torque/40 kg) at above 91% overall efficiency 300 Vdc battery for a peak phase current of 520 A. After searching quite a few alternative electric machines the low weight (40 kg) NdFeB (1.1 T) PM-Reluctance synchronous machine with vector control was developed in detail. Finite element validation of flux density, torque, inductances and non-reconfigurable vector control for the entire peak torque (power) very challenging envelope substantiate a moderate cost high performance HEV (EV) drive.
This study reports on the development of electrospun poly(2-hydroxyethyl methacrylate) (pHEMA) fi... more This study reports on the development of electrospun poly(2-hydroxyethyl methacrylate) (pHEMA) fibers loaded with synthetic and natural antioxidants in the form of selected types of polyphenols such as vanillic, gallic, syringic acids, catechin or natural spruce bark extract to investigate their release behavior in terms of antioxidant activities. Homogenous fiber morphologies were obtained at specified concentration ranges of pHEMA within the spinning solutions, exhibiting fiber diameters in the range from 0.5±0.1μm to 1.9±0.5μm. The addition of polyphenols resulted in an increase of fiber diameters with increasing concentration of additives. This is attributed to the effect of hydrogen bonding between the active ingredients and the polymeric matrix, increasing shear viscosities and thus hindering effective drawing processes during fiber formation. Polyphenol release measurement gave high release rates in a first phase followed by a smooth release at long term. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, used to monitor antioxidant activity, showed that polyphenols had retained their activity after incorporation into the pHEMA nanofibers. Furthermore, it was demonstrated that the encapsulation of polyphenols in pHEMA nanofibers can delay to a high extent their degradation induced by environmental factors.
ABSTRACT Aromatic polyimides possess high thermal stability, flexibility, good chemical resistanc... more ABSTRACT Aromatic polyimides possess high thermal stability, flexibility, good chemical resistance, mechanical strength, enhanced dielectric properties, being thus widespread used in electronic and microelectronic industry or as a support in high temperature applications. Herein, a soluble functional polyimide with pendant phenol groups was synthesized and its potential to stabilize gold nanoparticles was highlighted by comparison with an aromatic polyimide with similar backbone but lacking the phenol units. Furthermore, composite nanofibers based on the polyimide bearing phenol units and gold nanoparticles were prepared by using an in-situ e-spinning approach. Electrostatic spinning revealed homogenous fiber formation with diameters in the range of 0.28–0.77μm for pure polyimide, whereas for gold containing polyimide beaded fiber morphologies with diameters in the range of 50–60nm were determined. A clear influence of the solution properties was measured regarding fiber diameters. Thermal treatment of the composite nanofibers yielded highly dispersed embedded metallic gold particles exhibiting diameters in the range of 9–22nm, with an increase in particle diameters by enlarging the thermal exposure time. The thermal stability of the composite nanofibers was evaluated by thermogravimetric analysis (TGA) and only a slight decrease in the decomposition temperature in comparison to the pristine polyimide-based nanofibers was observed. Finally, we investigated the effect of thermal treatment on the optical properties of the new nanofibers and we revealed the possibility of tuning the reflective characteristics of the nanofibrous surfaces in function of the annealing time.
Here we show a method for patterning a thin metal film using self-assembled block-copolymer micel... more Here we show a method for patterning a thin metal film using self-assembled block-copolymer micelles monolayers as a template. The obtained metallic mask is transferred by reactive ion etching in silicon oxide, silicon and silicon nitride substrates, thus fabricating arrays of hexagonally packed nanopores with tunable diameters, interspacing and aspect ratios. This technology is compatible with integration into a standard microtechnology sequence for wafer-scale fabrication of ultrathin silicon nitride nanoporous membranes with 80 nm mean pore diameter.
Annals of University of Craiova Economic Sciences Series, 2008
Romania attracted large inflows of foreign direct investments (FDI), thanks to an improved busine... more Romania attracted large inflows of foreign direct investments (FDI), thanks to an improved business environment and still-low labor costs. Romania offers to the foreign investors many major reasons to invest in Romania: great market potential, strategic location, significant natural resources, high skilled labor force, high potential for economic growth, new EU member, infrastructure growing steadily, friendly business environment, access to European funds, competitive taxation. But still there are possible many contradictories evolutions generated both by Romanian government decisions and by the influence of the external factors. Virtually, the size on the above potential shows the countries with low FDI potential but strong FDI performance. The same time, the United Nations Conference on Trade and Development (UNCTAD) matrix considers that Romanian economy has less advantages than the Romanian Agency for Foreign Investment (ARIS) offers. Therefore, Romania is below potential wanted by foreign investors. Therefore many challenges must be addressed to enhance competitiveness and to attract additional FDI. The Foreign Investors Council (the FIC) from Romania believes that Romania must still improve the enforcement of new laws and regulations; tackle major social reforms, including reform of the labor market; increase its competitiveness and improve its infrastructure.
This article describes the morphological and chemical characterization of stimuli-responsive func... more This article describes the morphological and chemical characterization of stimuli-responsive functionalized silicon surfaces provided in parallel by atomic force spectroscopy (AFM) and Fourier transform infrared spectroscopy (FT-IR) enhanced by the single-beam sample reference attenuated total reflection method (SBSR-ATR). The stimuli-responsive behavior of the surfaces was obtained by grafting-to in melt carboxyl-terminated poly-N-isopropylacryl amides (PNIPAAM) with different degree of polymerization (DP) on epoxide-functionalized silicon substrates. The unprecedented real time and in situ physicochemical insight into the temperature-triggered response of the densely packed superficial brushes allowed for the selection of a PNIPAAM with a specific DP as a suitable polymer for the fabrication of silicon membranes exhibiting switchable nanopores. The fabrication process combines the manufacture of nanoporous silicon surfaces and their subsequent chemical functionalization by the grafting-to in melt of the selected polymer. Then, relevant information was obtained in what concerns the chemical modifications behind the topographical changes that drive the functioning of PNIPAAM-based hybrid nanovalves as well as the timescale on which the opening and closing of the nanopores occur.
Abstract The performance of the public sector affects us all. There are at least three reasons wh... more Abstract The performance of the public sector affects us all. There are at least three reasons why we should be interested in how well it functions: it is big; its outputs are special; and it is getting bigger. With all these, in Romania, the performance within the public sector ...
Here we describe the fabrication and characterization of selective nanocomposite membranes based ... more Here we describe the fabrication and characterization of selective nanocomposite membranes based on ethylene-vinyl alcohol copolymers and polyoxomolybdate clusters. Larger "buckyball"-type polyoxomolybdates have been shown to display hydrophilic pores which allow the transport of water molecules but prevent the passage of larger, hydrophobic molecules. Upon incorporation of these clusters into flexible polymeric matrices, membranes with high water vapor transmission rate and low permeability towards organic solvents were obtained. These systems open new perspectives for the fabrication of chemical protective equipment with an increased level of comfort.
: This article treats the correlation between the investment projects and financing difficulties ... more : This article treats the correlation between the investment projects and financing difficulties in a vicious circle during the crisis. First of all, Romania, as the whole world, should reconsider the planning problems, taking into consideration two problems: from one point ...
Page 1. POUR L'OBTENTION DU GRADE DE DOCTEUR ÈS SCIENCES PAR acceptée sur propos... more Page 1. POUR L'OBTENTION DU GRADE DE DOCTEUR ÈS SCIENCES PAR acceptée sur proposition du jury: Prof. U. Röthlisberger, présidente du jury Prof. JA Hubbell, Dr R. Pugin, directeurs de thèse Prof. J. Brugger, rapporteur Prof. W. Meier, rapporteur Prof. ...
This article aims to provide a longitudinal presentation of developments in Romanian accounting d... more This article aims to provide a longitudinal presentation of developments in Romanian accounting during the 20th century and to propose a neo-institutional explanation of this evolution.
2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM), 2014
ABSTRACT The aim of this paper is to introduce - by general analytical nonlinear and then optimal... more ABSTRACT The aim of this paper is to introduce - by general analytical nonlinear and then optimal design with vector control a hybrid electric and electric vehicles (HEV/EV) electric propulsion system for 50/100 kW, 1350-7000 rpm (600 Nm peak torque/40 kg) at above 91% overall efficiency 300 Vdc battery for a peak phase current of 520 A. After searching quite a few alternative electric machines the low weight (40 kg) NdFeB (1.1 T) PM-Reluctance synchronous machine with vector control was developed in detail. Finite element validation of flux density, torque, inductances and non-reconfigurable vector control for the entire peak torque (power) very challenging envelope substantiate a moderate cost high performance HEV (EV) drive.
This study reports on the development of electrospun poly(2-hydroxyethyl methacrylate) (pHEMA) fi... more This study reports on the development of electrospun poly(2-hydroxyethyl methacrylate) (pHEMA) fibers loaded with synthetic and natural antioxidants in the form of selected types of polyphenols such as vanillic, gallic, syringic acids, catechin or natural spruce bark extract to investigate their release behavior in terms of antioxidant activities. Homogenous fiber morphologies were obtained at specified concentration ranges of pHEMA within the spinning solutions, exhibiting fiber diameters in the range from 0.5±0.1μm to 1.9±0.5μm. The addition of polyphenols resulted in an increase of fiber diameters with increasing concentration of additives. This is attributed to the effect of hydrogen bonding between the active ingredients and the polymeric matrix, increasing shear viscosities and thus hindering effective drawing processes during fiber formation. Polyphenol release measurement gave high release rates in a first phase followed by a smooth release at long term. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, used to monitor antioxidant activity, showed that polyphenols had retained their activity after incorporation into the pHEMA nanofibers. Furthermore, it was demonstrated that the encapsulation of polyphenols in pHEMA nanofibers can delay to a high extent their degradation induced by environmental factors.
ABSTRACT Aromatic polyimides possess high thermal stability, flexibility, good chemical resistanc... more ABSTRACT Aromatic polyimides possess high thermal stability, flexibility, good chemical resistance, mechanical strength, enhanced dielectric properties, being thus widespread used in electronic and microelectronic industry or as a support in high temperature applications. Herein, a soluble functional polyimide with pendant phenol groups was synthesized and its potential to stabilize gold nanoparticles was highlighted by comparison with an aromatic polyimide with similar backbone but lacking the phenol units. Furthermore, composite nanofibers based on the polyimide bearing phenol units and gold nanoparticles were prepared by using an in-situ e-spinning approach. Electrostatic spinning revealed homogenous fiber formation with diameters in the range of 0.28–0.77μm for pure polyimide, whereas for gold containing polyimide beaded fiber morphologies with diameters in the range of 50–60nm were determined. A clear influence of the solution properties was measured regarding fiber diameters. Thermal treatment of the composite nanofibers yielded highly dispersed embedded metallic gold particles exhibiting diameters in the range of 9–22nm, with an increase in particle diameters by enlarging the thermal exposure time. The thermal stability of the composite nanofibers was evaluated by thermogravimetric analysis (TGA) and only a slight decrease in the decomposition temperature in comparison to the pristine polyimide-based nanofibers was observed. Finally, we investigated the effect of thermal treatment on the optical properties of the new nanofibers and we revealed the possibility of tuning the reflective characteristics of the nanofibrous surfaces in function of the annealing time.
Here we show a method for patterning a thin metal film using self-assembled block-copolymer micel... more Here we show a method for patterning a thin metal film using self-assembled block-copolymer micelles monolayers as a template. The obtained metallic mask is transferred by reactive ion etching in silicon oxide, silicon and silicon nitride substrates, thus fabricating arrays of hexagonally packed nanopores with tunable diameters, interspacing and aspect ratios. This technology is compatible with integration into a standard microtechnology sequence for wafer-scale fabrication of ultrathin silicon nitride nanoporous membranes with 80 nm mean pore diameter.
Annals of University of Craiova Economic Sciences Series, 2008
Romania attracted large inflows of foreign direct investments (FDI), thanks to an improved busine... more Romania attracted large inflows of foreign direct investments (FDI), thanks to an improved business environment and still-low labor costs. Romania offers to the foreign investors many major reasons to invest in Romania: great market potential, strategic location, significant natural resources, high skilled labor force, high potential for economic growth, new EU member, infrastructure growing steadily, friendly business environment, access to European funds, competitive taxation. But still there are possible many contradictories evolutions generated both by Romanian government decisions and by the influence of the external factors. Virtually, the size on the above potential shows the countries with low FDI potential but strong FDI performance. The same time, the United Nations Conference on Trade and Development (UNCTAD) matrix considers that Romanian economy has less advantages than the Romanian Agency for Foreign Investment (ARIS) offers. Therefore, Romania is below potential wanted by foreign investors. Therefore many challenges must be addressed to enhance competitiveness and to attract additional FDI. The Foreign Investors Council (the FIC) from Romania believes that Romania must still improve the enforcement of new laws and regulations; tackle major social reforms, including reform of the labor market; increase its competitiveness and improve its infrastructure.
This article describes the morphological and chemical characterization of stimuli-responsive func... more This article describes the morphological and chemical characterization of stimuli-responsive functionalized silicon surfaces provided in parallel by atomic force spectroscopy (AFM) and Fourier transform infrared spectroscopy (FT-IR) enhanced by the single-beam sample reference attenuated total reflection method (SBSR-ATR). The stimuli-responsive behavior of the surfaces was obtained by grafting-to in melt carboxyl-terminated poly-N-isopropylacryl amides (PNIPAAM) with different degree of polymerization (DP) on epoxide-functionalized silicon substrates. The unprecedented real time and in situ physicochemical insight into the temperature-triggered response of the densely packed superficial brushes allowed for the selection of a PNIPAAM with a specific DP as a suitable polymer for the fabrication of silicon membranes exhibiting switchable nanopores. The fabrication process combines the manufacture of nanoporous silicon surfaces and their subsequent chemical functionalization by the grafting-to in melt of the selected polymer. Then, relevant information was obtained in what concerns the chemical modifications behind the topographical changes that drive the functioning of PNIPAAM-based hybrid nanovalves as well as the timescale on which the opening and closing of the nanopores occur.
Abstract The performance of the public sector affects us all. There are at least three reasons wh... more Abstract The performance of the public sector affects us all. There are at least three reasons why we should be interested in how well it functions: it is big; its outputs are special; and it is getting bigger. With all these, in Romania, the performance within the public sector ...
Here we describe the fabrication and characterization of selective nanocomposite membranes based ... more Here we describe the fabrication and characterization of selective nanocomposite membranes based on ethylene-vinyl alcohol copolymers and polyoxomolybdate clusters. Larger "buckyball"-type polyoxomolybdates have been shown to display hydrophilic pores which allow the transport of water molecules but prevent the passage of larger, hydrophobic molecules. Upon incorporation of these clusters into flexible polymeric matrices, membranes with high water vapor transmission rate and low permeability towards organic solvents were obtained. These systems open new perspectives for the fabrication of chemical protective equipment with an increased level of comfort.
: This article treats the correlation between the investment projects and financing difficulties ... more : This article treats the correlation between the investment projects and financing difficulties in a vicious circle during the crisis. First of all, Romania, as the whole world, should reconsider the planning problems, taking into consideration two problems: from one point ...
Page 1. POUR L'OBTENTION DU GRADE DE DOCTEUR ÈS SCIENCES PAR acceptée sur propos... more Page 1. POUR L'OBTENTION DU GRADE DE DOCTEUR ÈS SCIENCES PAR acceptée sur proposition du jury: Prof. U. Röthlisberger, présidente du jury Prof. JA Hubbell, Dr R. Pugin, directeurs de thèse Prof. J. Brugger, rapporteur Prof. W. Meier, rapporteur Prof. ...
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