989 resultados para Sturm, Julia
Resumo:
Yrityksen ulkoisen toimintaympäristön arviointia pidetään yleisesti yhä tärkeämpänä yrityksen menestymisen kannalta. Kuitenkaan ympäristöanalyysiä ei juurikaan systemaattisesti hyödynnetä varsinkaan pk-yrityksissä. Tämän työn tavoitteena on saada pk-yrittäjät ymmärtämään paremmin ympäristön arviointia, sen tärkeyttä ja sen soveltamista käytännössä. Työssä keskitytään makrotason ympäristöanalyysiin, sillä se toimii lähtökohtana kokonaisvaltaiselle ympäristön arvioinnille. Ympäristön arvioinnista esitetään useita eri näkökulmia, jonka jälkeen makrotason analyysiä lähestytään PESTEL-viitekehyksen kautta. Työn liitteenä on PESTEL-viitekehyksen pohjalta rakennettu työkalu, jonka avulla pk-yrityksille on helpompaa lähteä toteuttamaan ympäristön arviointia. Työssä käsitellään myös vuonna 2009 käsillä olevaa talouskriisiä PESTEL-mallin kautta. Talouskriisi luo yrityksille poikkeukselliset olosuhteet, jotka osaltaan vaikeuttavat ympäristön arviointia. Työn perusteella toimintaympäristön arviointi on yrityksille tärkeää elossa säilymisen kannalta. Ympäristön muutoksiin voidaan varautua ennakkoon esimerkiksi skenaarioin tai heikoin signaalein. PESTEL-tekijät riippuvat yrityksen koosta ja kansallisuudesta, tässä työssä on keskitytty käsittelemään asiaa suomalaisten pk-yritysten kannalta. Asian käsittely kirjallisuudessa on pintapuolista ja hajanaista, vaikka keskeinen sisältö olisi hyvä saada kattavasti yhdeksi kokonaisuudeksi.
Resumo:
The aim of the work is to study the existing analytical calculation procedures found in literature to calculate the eddy-current losses in surface mounted permanent magnets within PMSM application. The most promising algorithms are implemented with MATLAB software under the dimensional data of LUT prototype machine. In addition finite elements analyze, utilized with help of Flux 2D software from Cedrat Ltd, is applied to calculate the eddy-current losses in permanent magnets. The results obtained from analytical methods are compared with numerical results.
Resumo:
Contaminant gases in the atmosphere constitute an important problem to be solved in the world. The NOx gases produced as a consequence of engine high temperatures are deleterious to environment and human health, as they promote acid rain and can act in the same way as freons in the destruction of the ozone layer in the stratosphere. In this review, three way and selective reduction catalysts for decomposition of these contaminant gases are described. Details about conditions and problems, such as catalyst poisoning, and the search for new catalysts are shown.
Resumo:
Aluminum oxide was dispersed on a commercial silica gel surface, using successive grafting reactions. The reaction products were characterized by N2 adsorption-desorption isotherms, scanning electron microscopy and infrared spectroscopy. The progressive incorporation of aluminum, up to 5.5% (w/w), does not produce agglomeration of alumina, since changes in the original pore size distribution of the silica matrix were not observed. The aluminum oxide covers homogeneously the silica surface.
Resumo:
The Nucleus accumbens (Nacc) has been proposed to act as a limbic-motor interface. Here, using invasive intraoperative recordings in an awake patient suffering from obsessive-compulsive disease (OCD), we demonstrate that its activity is modulated by the quality of performance of the subject in a choice reaction time task designed to tap action monitoring processes. Action monitoring, that is, error detection and correction, is thought to be supported by a system involving the dopaminergic midbrain, the basal ganglia, and the medial prefrontal cortex. In surface electrophysiological recordings, action monitoring is indexed by an error-related negativity (ERN) appearing time-locked to the erroneous responses and emanating from the medial frontal cortex. In preoperative scalp recordings the patient's ERN was found to be signifi cantly increased compared to a large (n = 83) normal sample, suggesting enhanced action monitoring processes. Intraoperatively, error-related modulations were obtained from the Nacc but not from a site 5 mm above. Importantly, crosscorrelation analysis showed that error-related activity in the Nacc preceded surface activity by 40 ms. We propose that the Nacc is involved in action monitoring, possibly by using error signals from the dopaminergic midbrain to adjust the relative impact of limbic and prefrontal inputs on frontal control systems in order to optimize goal-directed behavior.
Resumo:
Implantation of deep brain stimulation (DBS) electrodes via stereotactic neurosurgery has become a standard procedure for the treatment of Parkinson's disease. More recently, the range of neuropsychiatric conditions and the possible target structures suitable for DBS have greatly increased. The former include obsessive compulsive disease, depression, obesity, tremor, dystonia, Tourette's syndrome and cluster-headache. In this article we argue that several of the target structures for DBS (nucleus accumbens, posterior inferior hypothalamus, nucleus subthalamicus, nuclei in the thalamus, globus pallidus internus, nucleus pedunculopontinus) are located at strategic positions within brain circuits related to motivational behaviors, learning, and motor regulation. Recording from DBS electrodes either during the operation or post-operatively from externalized leads while the patient is performing cognitive tasks tapping the functions of the respective circuits provides a new window on the brain mechanisms underlying these functions. This is exemplified by a study of a patient suffering from obsessive-compulsive disease from whom we recorded in a flanker task designed to assess action monitoring processes while he received a DBS electrode in the right nucleus accumbens. Clear error-related modulations were obtained from the target structure, demonstrating a role of the nucleus accumbens in action monitoring. Based on recent conceptualizations of several different functional loops and on neuroimaging results we suggest further lines of research using this new window on brain functions.
Resumo:
The ventral striatum / nucleus accumbens has been implicated in the craving for drugs and alcohol which is a major reason for relapse of addicted people. Craving might be induced by drug-related cues. This suggests that disruption of craving-related neural activity in the nucleus accumbens may significantly reduce craving in alcohol-dependent patients. Here we report on preliminary clinical and neurophysiological evidence in three male patients who were treated with high frequency deep brain stimulation of the nucleus accumbens bilaterally. All three had been alcohol dependent for many years, unable to abstain from drinking, and had experienced repeated relapses prior to the stimulation. After the operation, craving was greatly reduced and all three patients were able to abstain from drinking for extended periods of time. Immediately after the operation but prior to connection of the stimulation electrodes to the stimulator, local field potentials were obtained from the externalized cables in two patients while they performed cognitive tasks addressing action monitoring and incentive salience of drug related cues. LFPs in the action monitoring task provided further evidence for a role of the nucleus accumbens in goal-directed behaviors. Importantly, alcohol related cue stimuli in the incentive salience task modulated LFPs even though these cues were presented outside of the attentional focus. This implies that cue-related craving involves the nucleus accumbens and is highly automatic.
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The preparation of [FeIV(O)(MePy2tacn)]2+ (2, MePy2tacn = N-methyl-N,N-bis(2-picolyl)-1,4,7-triazacyclononane) by reaction of [FeII(MePy2tacn)(solvent)]2+ (1) and PhIO in CH3CN and its full characterization are described. This compound can also be prepared photochemically from its iron(II) precursor by irradiation at 447 nm in the presence of catalytic amounts of [Ru II(bpy)3]2+ as photosensitizer and a sacrificial electron acceptor (Na2S2O8). Remarkably, the rate of the reaction of the photochemically prepared compound 2 toward sulfides increases 150-fold under irradiation, and 2 is partially regenerated after the sulfide has been consumed; hence, the process can be repeated several times. The origin of this rate enhancement has been established by studying the reaction of chemically generated compound 2 with sulfides under different conditions, which demonstrated that both light and [Ru II(bpy)3]2+ are necessary for the observed increase in the reaction rate. A combination of nanosecond time-resolved absorption spectroscopy with laser pulse excitation and other mechanistic studies has led to the conclusion that an electron transfer mechanism is the most plausible explanation for the observed rate enhancement. According to this mechanism, the in-situ-generated [RuIII(bpy)3] 3+ oxidizes the sulfide to form the corresponding radical cation, which is eventually oxidized by 2 to the corresponding sulfoxide
DUODES: Paraules clau d'història de les dones a Catalunya, segles IX-XVIII: una proposta de tesaurus
Resumo:
Sobre una proposta de tesaurus amb les paraules clau d'història de les dones de Catalunya dels segles IX a XVIII, realitzat per les dones de les seccions d'Història Medieval i Moderna del Centre d'lnvestigació Històrica de la Dona de la Universitat de Barcelona (DUODA)
Resumo:
Sobre la configuració general d'una proposta de tesaurus amb les paraules clau d'història de les dones de Catalunya dels segles IX a XVIII, realitzat per les dones de les seccions d'Història Medieval i Moderna del Centre d'lnvestigació Històrica de la Dona de la Universitat de Barcelona (DUODA)
Resumo:
Esta ponencia se enmarca en la línea de anteriores trabajos nuestros, en los que se ha intentado ofrecer el panorama general de la investigación llevada a cabo en el campo de la diferenciación educativa, y, más en concreto de la educación intercultural. En «Diseños y metodologías de investigación desde la perspectiva de la educación intercultural » (Bartolomé, 1992), tras una breve clarificación de términos asociados a la educación multicultural, analizábamos los principales métodos de investigación y campos de estudio que se habían desarrollado a lo largo de este siglo en el ámbito mundial. En «Modelos de investigación en la intervención educativa diferencial» (Bartolomé, Cabrera, F., Espín, J., Marín, M.A., Del Rincón, D. y Rodríguez, M., 1993) nos centrábamos en un marco más amplio, intentando abordar el estado de la investigación en ese momento en cada una de las áreas temáticas, al tiempo que profundizábamos en los principales problemas metodológicos hallados.
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We would like to introduce our group of research, [CONTRA TAEDIUM], created by professionals from different fields, that have contributed in this article. Our purpose is to expose our reflections based on our own experiences, not only in research, but also in teaching. We propose new forms of writing history in order to understand the dairy life of the women and men of the past, from birth to death. We would like to point out that interacting all types of sources is essential to understand our history. But, what really makes sense is to bring our students in the historical methodology and involve them in their education. Moreover, it is necessary to design new teaching materials using the new technologies, although it requires team-work and a great, but satisfying, effort
Resumo:
The corrosion resistance of the new Ti-6Al-4V-1Zr alloy in comparison with ternary Ti-6Al-4V alloy in Ringer-Brown solution and artificial Carter-Brugirard saliva of different pH values was studied. In Ringer-Brown solution, the new alloy presented an improvement of all electrochemical parameters due to the alloying with Zr; also, impedance spectra revealed better protective properties of its passive layer. In Carter-Brugirard artificial saliva, an increase of the passive film thickness was proved. Fluoride ions had a slight negative influence on the corrosion and ion release rates, without to affect the very good stability of the new Ti-6Al-4V-1Zr alloy.
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Poly(D,L-lactide), PDLLA, is a polymer with potential applications in medical, environmental, and pharmaceutical areas. Despite its versatility, the hydrophobicity limits its applications. To overcome this problem, one strategy is the preparation of blends with hydrophilic polymers such as poly(vinylpyrrolidone), PVP. In this study, we report the preparation and characterization of blends based on PDLLA and PVP and the biodegradation studies by the Sturm test. It was observed that the components of the blends PDLLA/PVP are thermodynamically immiscible, however the biodegradation is faster than that of pure PDLLA.
Resumo:
An interesting practical experiment about the preparation of dye–sensitized solar cells (DSSC) using natural dyes were carried out by the undergraduate students in the chemistry course at UNICAMP . Natural dyes were extracted from blueberries (Vaccinium myrtillus L.), jabuticabas (Myrciaria cauliflora), raw and cooked beets (Beta vulgaris L.), and annattos (Bixa orellana L.), which were used to sensitize TiO2 films that composed the photoanode in the DSSC. A polymer electrolyte containing an iodide/triiodide redox couple was used in lieu of the use of liquid solutions to prevent any leakage in the devices. A maximum solar-to-electric energy conversion of 0.26 ± 0.02% was obtained for the solar cell prepared with annatto extracts. This experiment was an effective way to illustrate to the undergraduate students how to apply some of the chemical concepts that they learned during their chemistry course to produce electric energy from a clean and renewable energy source. Teachers could also exploit the basics of the electronic transitions in inorganic and organic compounds (e.g., metal-to-ligand charge transfer and ϖ-ϖ* transitions), thermodynamics (e.g., Gibbs free energy), acid–base reactions in the oxide solid surface and electrolyte, and band theory (i.e., the importance of the Fermi level energy).