24 research outputs found

    Economic and social disparities of Romania in regional and county profile

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    Romania's accession to the European Union imposes a new way of approaching the economic and social disparities existing nowadays both at the level of the eight development regions of the country and at the level of counties as well. The analysis of the level and evolution of these disparities can be useful to all the factors that design and put into practice strategies meant to stop the gaps widening on one hand and to fill the existing gaps among the Romanian development regions on the other hand. All these analyses are made from the perspective of Romania's process of integration into the European Union's structures.convergence objective, development regions, economic disparities, EU cohesion, Principal Components Analysis.

    Intergenerational knowledge transfer in the academic environment of knowledge-based economy

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    In the immediate future, intergenerational knowledge transfer is one of the knowledge-based economy’s main challenges since an inner motivational force powers knowledge transfer. Knowledge transfer from individuals to groups and organization must follow knowledge creation in order to transform individual into organizational knowledge, along the epistemological dimension of the Nonaka’s knowledge dynamics model. Moreover, the knowledge intensive organizations increase their fluxes of knowledge across different age layers and different departments, reducing in the same time the company knowledge loss. The academic environment is, by nature, an age layered field or a nested functional structure. Intergenerational knowledge transfer becomes any university main driving force, while understanding its dynamics is important for academic life improvement. The purpose of the paper is to present some of our research results in the field of intergenerational knowledge transfer in the academic environment of the knowledge-based economy. We performed a qualitative and quantitative research of the knowledge transfer process in the academic environment, using the Analytic Hierarchy Processes (AHP). We analyzed the faculty staff attitudes toward cooperation, competition, and innovation as main priorities in performing research, writing books and publishing scientific papers. The above-mentioned activities are based on intergenerational knowledge transfer and lead to learning processes at individual and organizational levels. Respondents are members of the academic staff of economics and business faculties from the main Romanian universities.knowledge, knowledge-based economy, knowledge transfer, university

    Intergenerational knowledge transfer in the academic environment of knowledge-based economy

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    In the immediate future, intergenerational knowledge transfer is one of the knowledge-based economy’s main challenges since an inner motivational force powers knowledge transfer. Knowledge transfer from individuals to groups and organization must follow knowledge creation in order to transform individual into organizational knowledge, along the epistemological dimension of the Nonaka’s knowledge dynamics model. Moreover, the knowledge intensive organizations increase their fluxes of knowledge across different age layers and different departments, reducing in the same time the company knowledge loss. The academic environment is, by nature, an age layered field or a nested functional structure. Intergenerational knowledge transfer becomes any university main driving force, while understanding its dynamics is important for academic life improvement. The purpose of the paper is to present some of our research results in the field of intergenerational knowledge transfer in the academic environment of the knowledge-based economy. We performed a qualitative and quantitative research of the knowledge transfer process in the academic environment, using the Analytic Hierarchy Processes (AHP). We analyzed the faculty staff attitudes toward cooperation, competition, and innovation as main priorities in performing research, writing books and publishing scientific papers. The above-mentioned activities are based on intergenerational knowledge transfer and lead to learning processes at individual and organizational levels. Respondents are members of the academic staff of economics and business faculties from the main Romanian universities

    Electronic cost alternatives for e-commerce

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    The e-commerce can lead to cost reduction in case of a supplier in many different ways and can subsequently increase the competition potential of an enterprise. The e-commerce generates on average lower costs than those coming up if it were to reduce them by considering their components. As for the competition mechanism, such changes produce significant modifications within a market economy. The Internet renders the possibility of creating business contacts in a rapid and geographically independent manner as well as of obtaining data and of realizing transactions within world economy.Information technology; costs; e-commerce; electronic markets; added value.

    PRINCIPLES OF INTEGRATION THE AGRI-DRONES IN AGRICULTURAL PRODUCTION ENVIRONMENTS. NEW CONCEPTS TOWARDS AGRICULTURE-5.0

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    Unmanned aerial systems (UAS) have a crucial contribution to the development of precision agriculture (PA). Agricultural drones or agri-drones make the rapid transition from the military system (UAVs) to domestic applications in the PA, in order to provide the necessary support to farmers for the surveillance of large crops and / or in carrying out operations to protect or stimulate crops. This revolutionary leap contributes to the considerable savings of the farmer, as well as to the revolution of traditional agriculture towards intelligent agriculture or PA. Managerial decisions based on the three principles presented in the paper (EVI - Enhanced Vegetation Index, ZP - Zero Pollution and ROI - Return on Investment) are easier to make through the approach driven by digital technology. The information-based management cycle lays foundations for sustainable PA of the future (agriculture-5.0)

    The complexity of the living entity - a new paradigm

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    The authors of this paper consider themselves as adepts of Adler’s theory sustaining the idea that human beings cannot authentically progress outside the acknowledgement of their feelings and interconnectedness for living and work activities as parts of the whole society. Following this point of view, the achievement of all necessities of life, inside the society, is a systemic process of consciousness supposing the freedom as an assumed responsibility. From this perspective, the humanity should switch from the knowledge based society’s concepts to those of the application of assumed responsibility where scientific knowledge becomes a must to knowing and evaluating the whole living soundness at any level (individuals, family, official entities and authorities, communities, environment). We will use the term of network effect generated by the communication for the whole living of the national academic society facing deep challenges and transformations. This way we intend to promote the re-spiritualization of the education under a national program, so that the durable change be produced and proved, from the inside to the outside of our daily societal life . Working on a model to set up a new way to measuring the soundness of any whole living, we are applying the model to determine the soundness of an university; to understand the evolution of the whole it is necessary to study the evolution and reaction of its components.peer-reviewe

    Charge Transport and Electrical Properties of Spin Crossover Materials: Towards Nanoelectronic and Spintronic Devices

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    In this paper, we present a comprehensive review of research on electrical and charge transport properties of spin crossover complexes. This includes both the effect of spin-state switching on the dielectric permittivity and electrical conductivity of the material and vice versa the influence of an applied electrical field (or current) on the spin-state of the system. The survey covers different size scales from bulk materials and thin films to nanoparticles and single molecules and embraces the presentation of several device prototypes and hybrid materials as well

    Study of electrical properties of bistable molecular materials : towards nanoelectronic devices

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    L'objectif central de cette thèse est l'évaluation de la possibilité d'utilisation de complexes moléculaires à transitions de spin pour des applications en nano-électronique. Dans un premier temps, les propriétés électriques du complexe [Fe(Htrz)2(trz)](BF4) et de ces analogues [Fe1-xZnx(Htrz)2(trz)](BF4) ont été analysées sous forme de poudres au moyen de la spectroscopie diélectrique. Il a été montré que les conductivités AC et DC aussi bien que la constante diélectrique et que la fréquence de relaxation diélectrique subissent une baisse importante lors de la transition de l'état bas spin (BS) vers l'état haut spin (HS). Les molécules à base de cations de fer gardent leurs propriétés de transition de spin dans les échantillons dilués de Zn, mais les courbes de transition de spin sont considérablement altérées. La substitution par Zn des centres de fer actifs mène à une importante baisse de la conductivité électrique d'environ 6 ordres de grandeur (pour Zn/Fe = 0.75). Nous concluons de ces résultats que les ions Fe(II) participent directement au processus de transport des charges, qui a été analysé dans le cadre d'un modèle de conductivité par saut de porteurs de charge activé thermiquement. Des particules micrométriques de [Fe(Htrz)2(trz)](BF4) ont été alors intégrées par diélectrophorèse entre des électrodes d'or. Ainsi, nous avons obtenu un dispositif montrant un phénomène de bistabilité lors de la caractérisation I-V, T. La stabilité du matériau initial et le dispositif électronique ont été contrôlés avec précision et les effets concomitants de changements de températures, d'irradiation lumineuse et du champ électrique sur l'intensité du courant ont été analysés en détail. D'une part, nous avons montré que le dispositif peut être adressé de manière préférentielle par une irradiation lumineuse en fonction de son état de spin, et d'autre part, nous avons démontré la commutation de l'état métastable HS vers l'état stable BS par application d'un champ électrique à l'intérieur du cycle d'hystérésis. Les effets de champ ont été discutés dans le cadre de modèles de type Ising statiques et dynamiques, tandis que les phénomènes photo-induits étaient attribués à des effets de surface. Le complexe [Fe(H2B(pz)2)2(phen)] a également été caractérisé par spectroscopie diélectrique sous forme de poudre et ensuite intégré par évaporation thermique sous vide au sein d'un dispositif vertical entre les électrodes en Al et ITO. Cette approche nous a permis de sonder la commutation de l'état de spin dans la couche de [Fe(bpz)2(phen)] par des moyens optiques tout en détectant les changements de résistance associés, à la fois dans les régimes à effet tunnel (jonction de 10 nm) et dans les régimes à injection (jonctions de 30 et 100 nm). Le courant tunnel dans les jonctions à transition de spin diminue durant la commutation de l'état BS vers l'état HS, tandis que le comportement de rectification des jonctions " épaisses " ne révélait aucune dépendance significative à l'état de spin. L'ensemble de ces résultats ouvre la voie à de nouvelles perspectives pour la construction de dispositifs électroniques et spintroniques incorporant des matériaux à transition de spin.The central theme of this thesis is the evaluation of potential interest and applicability of molecular spin crossover (SCO) complexes for nanoelectronic applications. The electrical properties of the [Fe(Htrz)2(trz)](BF4) complex and its Zn substituted analogues were analyzed first in the bulk powder form using broadband dielectric spectroscopy. It has been shown that the ac and dc conductivities as well as the dielectric constant and the dielectric relaxation frequency exhibit an important drop when going from the low spin (LS) to the high spin (HS) state. The iron ions kept their spin transition properties in the Zn diluted samples, but the SCO curves were significantly altered. The Zn substitution of active iron centers led to an important decrease of the electrical conductivity of ca. 6 orders of magnitude (for Zn/Fe = 0.75). We concluded from these results that the ferrous ions directly participate to the charge transport process, which was analyzed in the frame of an activated hopping conductivity model. Micrometric particles of [Fe(Htrz)2(trz)](BF4) were then integrated by dielectrophoresis between interdigitated gold electrodes leading to a device exhibiting bistability in the I-V,T characteristics. The stability of the starting material and the electronic device were carefully controlled and the concomitant effect of temperature changes, light irradiation and voltage bias on the current intensity were analyzed in detail. We showed that the device can be preferentially addressed by light stimulation according to its spin state and the switching from the metastable HS to the stable LS state was also demonstrated by applying an electric field step inside the hysteresis loop. The field effects were discussed in the frame of static and dynamic Ising-like models, while the photo-induced phenomena were tentatively attributed to surface phenomena. The [Fe(bpz)2(phen)] complex was also investigated by dielectric spectroscopy in the bulk powder form and then integrated by high vacuum thermal evaporation into a large-area vertical device with Al (top) and ITO (bottom) electrodes. This approach allowed us to probe the spin-state switching in the SCO layer by optical means while detecting the associated resistance changes both in the tunneling (10 nm junction) and injection-limited (30 and 100 nm junctions) regimes. The tunneling current in the thin SCO junctions showed a drop when going from the LS to the HS state, while the rectifying behavior of the 'thick' junctions did not reveal any significant spin-state dependence. The ensemble of these results provides guidance with new perspectives for the construction of electronic and spintronic devices incorporating SCO molecular materials

    Etudes des propriétés électriques des matériaux à transition de spin : vers des dispositifs pour la nano-électronique

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    The central theme of this thesis is the evaluation of potential interest and applicability of molecular spin crossover (SCO) complexes for nanoelectronic applications. The electrical properties of the [Fe(Htrz)2(trz)](BF4) complex and its Zn substituted analogues were analyzed first in the bulk powder form using broadband dielectric spectroscopy. It has been shown that the ac and dc conductivities as well as the dielectric constant and the dielectric relaxation frequency exhibit an important drop when going from the low spin (LS) to the high spin (HS) state. The iron ions kept their spin transition properties in the Zn diluted samples, but the SCO curves were significantly altered. The Zn substitution of active iron centers led to an important decrease of the electrical conductivity of ca. 6 orders of magnitude (for Zn/Fe = 0.75). We concluded from these results that the ferrous ions directly participate to the charge transport process, which was analyzed in the frame of an activated hopping conductivity model. Micrometric particles of [Fe(Htrz)2(trz)](BF4) were then integrated by dielectrophoresis between interdigitated gold electrodes leading to a device exhibiting bistability in the I-V,T characteristics. The stability of the starting material and the electronic device were carefully controlled and the concomitant effect of temperature changes, light irradiation and voltage bias on the current intensity were analyzed in detail. We showed that the device can be preferentially addressed by light stimulation according to its spin state and the switching from the metastable HS to the stable LS state was also demonstrated by applying an electric field step inside the hysteresis loop. The field effects were discussed in the frame of static and dynamic Ising-like models, while the photo-induced phenomena were tentatively attributed to surface phenomena. The [Fe(bpz)2(phen)] complex was also investigated by dielectric spectroscopy in the bulk powder form and then integrated by high vacuum thermal evaporation into a large-area vertical device with Al (top) and ITO (bottom) electrodes. This approach allowed us to probe the spin-state switching in the SCO layer by optical means while detecting the associated resistance changes both in the tunneling (10 nm junction) and injection-limited (30 and 100 nm junctions) regimes. The tunneling current in the thin SCO junctions showed a drop when going from the LS to the HS state, while the rectifying behavior of the 'thick' junctions did not reveal any significant spin-state dependence. The ensemble of these results provides guidance with new perspectives for the construction of electronic and spintronic devices incorporating SCO molecular materials.L'objectif central de cette thèse est l'évaluation de la possibilité d'utilisation de complexes moléculaires à transitions de spin pour des applications en nano-électronique. Dans un premier temps, les propriétés électriques du complexe [Fe(Htrz)2(trz)](BF4) et de ces analogues [Fe1-xZnx(Htrz)2(trz)](BF4) ont été analysées sous forme de poudres au moyen de la spectroscopie diélectrique. Il a été montré que les conductivités AC et DC aussi bien que la constante diélectrique et que la fréquence de relaxation diélectrique subissent une baisse importante lors de la transition de l'état bas spin (BS) vers l'état haut spin (HS). Les molécules à base de cations de fer gardent leurs propriétés de transition de spin dans les échantillons dilués de Zn, mais les courbes de transition de spin sont considérablement altérées. La substitution par Zn des centres de fer actifs mène à une importante baisse de la conductivité électrique d'environ 6 ordres de grandeur (pour Zn/Fe = 0.75). Nous concluons de ces résultats que les ions Fe(II) participent directement au processus de transport des charges, qui a été analysé dans le cadre d'un modèle de conductivité par saut de porteurs de charge activé thermiquement. Des particules micrométriques de [Fe(Htrz)2(trz)](BF4) ont été alors intégrées par diélectrophorèse entre des électrodes d'or. Ainsi, nous avons obtenu un dispositif montrant un phénomène de bistabilité lors de la caractérisation I-V, T. La stabilité du matériau initial et le dispositif électronique ont été contrôlés avec précision et les effets concomitants de changements de températures, d'irradiation lumineuse et du champ électrique sur l'intensité du courant ont été analysés en détail. D'une part, nous avons montré que le dispositif peut être adressé de manière préférentielle par une irradiation lumineuse en fonction de son état de spin, et d'autre part, nous avons démontré la commutation de l'état métastable HS vers l'état stable BS par application d'un champ électrique à l'intérieur du cycle d'hystérésis. Les effets de champ ont été discutés dans le cadre de modèles de type Ising statiques et dynamiques, tandis que les phénomènes photo-induits étaient attribués à des effets de surface. Le complexe [Fe(H2B(pz)2)2(phen)] a également été caractérisé par spectroscopie diélectrique sous forme de poudre et ensuite intégré par évaporation thermique sous vide au sein d'un dispositif vertical entre les électrodes en Al et ITO. Cette approche nous a permis de sonder la commutation de l'état de spin dans la couche de [Fe(bpz)2(phen)] par des moyens optiques tout en détectant les changements de résistance associés, à la fois dans les régimes à effet tunnel (jonction de 10 nm) et dans les régimes à injection (jonctions de 30 et 100 nm). Le courant tunnel dans les jonctions à transition de spin diminue durant la commutation de l'état BS vers l'état HS, tandis que le comportement de rectification des jonctions " épaisses " ne révélait aucune dépendance significative à l'état de spin. L'ensemble de ces résultats ouvre la voie à de nouvelles perspectives pour la construction de dispositifs électroniques et spintroniques incorporant des matériaux à transition de spin
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