Statistical approaches of the credit and the banking rating in the national economy

The appearance of the credit is closely related to the appearance of the commercial banks, the mobilization of the monetary disposals on the market and their efficient placement to the funds solicitors is being accomplished through credits. The credit giving can be generally described as the process through which a certain value is loaned to a potential debtor which has a certain activity, accepting a financial risk to the possibility that that person/entity may not be capable to fulfill their obligations in the future.bank credits, evolution, rating, the balance credit/deposits, weight of credits

Controlling the multipolar interference of nanoantennas

The emission and detection of light is a main pillar of both fundamental research and the advancement of modern technologies. From digital communications and quantum computing to novel cancer treatments and faded jeans, light-matter interactions are at the core of each of these things, and the fundamental building block of nearly every one of these interactions is the electric dipole. The emission and absorption from every molecule, atom, quantum dot and semiconductor is predominantly electric dipole by nature. While it is the most efficient, fastest, brightest, and easiest to understand process, it is not the only process by which light can be emitted and absorbed; magnetic dipoles, electric quadrupoles, and more, all exist in nature. Optical nanoantennas are the basic element for efficient interfacing between photons and single photon emitters, as they address the inherent size mismatch between the physical size of the emitters and the much larger wavelength of light with which they interact. Optical nanoantennas are also generally electric dipole in nature, as their fundamental resonance is that of an oscillating positive and negative charge. However, unlike nature, these antennas can be engineered to promote higher order modes so that non-electric dipole resonances are not the only contributor. The topic of this Thesis is the control of light emission through modes beyond the electric dipole, both from single emitters coupled to optical nanoantennas and from the emission of light directly from the antennas themselves. In the Introduction, we provide an overview of basic antenna theory, and in Chapter 1, we describe the experimental and theoretical methods used throughout this Thesis. In Chapter 2, we direct light emission from a quantum dot coupled to a two-dimensional antenna excited at a higher-order mode, and represent its emission pattern with a multipole expansion. To demonstrate the importance of a characteristic of light unavailable to spontaneous emission, its phase, we measure the angular emission patterns of second harmonic generation directly from single nanoantennas in Chapter 3, and once more model its patterns with the multipole model. In Chapter 4, we delve into the second harmonic generation from a crystalline semiconductor, and detect competing second order nonlinear processes that were not present in the previous chapter. Finally, in Chapter 5 we combine the previous three chapters and design an optical nanoantenna, which through two nonlinear processes that coexist when driven in a higher-order mode, radiates its second harmonic unidirectionally, with a switchable emission direction. The results in this Thesis demonstrate that not only can optical nanoantennas control light emission from single emitters, but that when they are also the emitters themselves we can actively switch the direction in which light is emitted. With this change in paradigm, we now have a new lever with which to tailor the emission of light at the nanoscale. This coherent control of light emission has potential applications in any technology that benefits from higher light-matter interaction efficiencies, and particularly those that require coherenceL'emissió i detecció de la llum és un pilar principal tant de la investigació fonamental com de l'avanç de les noves tecnologies. Des de les comunicacions digitals i la computació quàntica fins als nous tractaments del càncer i els texans degradats, les interaccions llum-matèria són el nucli de cadascuna d'aquestes qüestions, i el component fonamental de gairebé totes aquestes interaccions és el dipol elèctric. L'emissió i l'absorció de totes les molècules, àtoms, punts quàntics i semiconductors és predominantment de dipol elèctric per naturalesa. Si bé és el procés més eficient, ràpid, brillant i fàcil d'entendre, no és l'únic procés pel qual la llum pot ser emesa i absorbida; dipols magnètics, quadrupols elèctrics i molts més existeixen a la natura. Les nanoantenes òptiques són l'element bàsic per a una interfície eficient entre fotons i emissors de fotons individuals, ja que s'ocupen de la disparitat inherent entre la mida física dels emissors i la major longitud d'ona amb la qual interactuen. Les nanoantenes òptiques generalment són també un dipol elèctric, ja que la seva ressonància fonamental és la d'una càrrega positiva i negativa oscil·lant. Tanmateix, a diferència de la naturalesa, aquestes antenes es poden dissenyar per promoure modes d'ordre superior, de manera que les ressonàncies dipolars no elèctriques no siguin l'únic contribuent. El tema d'aquesta tesi és el control de l'emissió de llum a través de modes que no siguin de tipus dipol elèctric, tant d’emissors individuals acoblats a nanoantenes òptiques com de l'emissió de llum directament des de les pròpies antenes. A la Introducció, oferim una descripció general de la teoria bàsica de nanoantenes, i al Capítol 1 descrivim els mètodes experimentals i teòrics utilitzats al llarg d'aquesta tesi. En el Capítol 2, dirigim l'emissió de llum a partir d'un punt quàntic acoblat a una antena bidimensional excitada a un mode d'ordre superior, i representem el seu patró d'emissió amb una expansió multipolar. Per demostrar l'importància d'una característica de la llum no disponible a l'emissió espontània, la seva fase, mesurem els patrons angulars d'emissió de la generació de segon harmònic directament des de nanoantenes individuals en el Capítol 3. En el Capítol 4, aprofundim en la generació de segon harmònic a partir d'un semiconductor cristal·lí, i detectem processos no lineals de segon ordre competidors que no estaven presents al capítol anterior. Finalment, al Capítol 5, combinem els tres capítols anteriors i dissenyem una nanoantena òptica, que a través de dos processos no lineals que coexisteixen quan s'excita en un ordre d'ordre superior, emet el seu segon harmònic de forma unidireccional, amb aquesta direcció d'emissió sent invertible. Els resultats d'aquesta Tesi demostren que no només les nanoantenes òptiques controlen l'emissió de llum d'emissors individuals, sinó que quan elles mateixes són els emissors, podem canviar activament la direcció en què s'emet la llum. Amb aquest canvi de paradigma, tenim una eina nova per controlar l'emissió de llum a la nanoescala. Aquest control coherent de l'emissió de llum té aplicacions potencials en qualsevol tecnologia que es vulgui beneficiar d'una major eficiència en la interacció de la llum-matèria, i en particular d'aquelles que requereixen coherència.Postprint (published version

KNOWLEDGE SHARING RISKS IN COLLABORATIVE ENVIRONMENTS

Knowledge Management deals with a multitude of tasks that range from the representation to the evolution of knowledge in its various forms. Understanding the way in which knowledge is used contributes to the improvement of the Knowledge Management Systems at the organizational level. This paper aims at investigating the risks that appear in the process of Knowledge Sharing when two or more distinct companies with different enterprise cultures collaborate, as in the form of a Virtual Enterprise or a recently-completed Merger or Acquisition. We consider the risks identified in the research literature that are linked to the Knowledge Sharing Process in Virtual Organizations and discuss to which extent these risks might appear during the integration process of both Mergers and Acquisitions. An Automatic Supervisor Module of a Knowledge Management System is subsequently presented, with the purpose of continuously monitoring these risks and promoting the sharing of knowledge within a collaborative context.Knowledge Management, Knowledge Sharing, Virtual Organizations, Mergers and Acquisitions

Separation of 1,4-benzodiazepine Derivates by Micellar Electrokinetic Capillary Chromatography Using Cyclodextrines as Buffer Modifiers

The applicability of micellar electrokinetic capillary chromatography (MEKC) for the separation of benzodiazepine (BZD) derivates with different structural characteristics has been studied. Efforts were first focused on the optimization of the analytical conditions, on the effects of buffer concentration, surfactant concentration and buffer pH on the separation. To manipulate selectivity of the separation β- cyclodextrin (CD) was added to the buffer solution, and urea was used to improve the solubility of the CD in water. The CD-modified MEKC separation of the eight BZDs was achieved within 15 minutes using 25 mmol dm−3 natrium tetraborate-50 mmol dm−3 sodium dodecyl sulphate-15 mmol dm−3 β-CD-2 mol dm−3 urea (pH 9.3) as the running buffer. The proposed separation method was evaluated on the basis of precision, linearity and limit of detection. (doi: 10.5562/cca1763

Resonant plasmonic nanoparticles for multicolor second harmonic imaging

Nanoparticles capable of efficiently generating nonlinear optical signals, like second harmonic generation, are attracting a lot of attention as potential background-free and stable nano-probes for biological imaging. However, second harmonic nanoparticles of different species do not produce readily distinguishable optical signals, as the excitation laser mainly defines their second harmonic spectrum. This is in marked contrast to other fluorescent nano-probes like quantum dots that emit light at different colors depending on their sizes and materials. Here, we present the use of resonant plasmonic nanoparticles, combined with broadband phase-controlled laser pulses, as tunable sources of multicolor second harmonic generation. The resonant plasmonic nanoparticles strongly interact with the electromagnetic field of the incident light, enhancing the efficiency of nonlinear optical processes. Because the plasmon resonance in these structures is spectrally narrower than the laser bandwidth, the plasmonic nanoparticles imprint their fingerprints on the second harmonic spectrum. We show how nanoparticles of different sizes produce different colors in the second harmonic spectra even when excited with the same laser pulse. Using these resonant plasmonic nanoparticles as nano-probes is promising for multicolor second harmonic imaging while keeping all the advantages of nonlinear optical microscopy.Peer ReviewedPostprint (published version

Application of capillary electrophoresis to the simultaneous determination and stability study of four extensively used penicillin derivatives

The applicability of capillary electrophoresis for the analysis of four extensively used penicillin derivatives (benzylpenicillin, ampicillin, amoxicillin, oxacilllin) has been studied. Because of structural similarities, the electrophoretic behavior of these derivatives is very similar; consequently an efficient separation using the conventional capillary zone electrophoresis is hard to be achieved. Their simultaneous separation was solved by using micellar electrokinetic capillary chromatography, the separation being based on the differential partition of the analytes between the micellar and aqueous phase. Using a buffer solution containing 25 mM sodium tetraborate and 100 mM sodium dodecyl sulfate as surfactant, at a pH of 9.3, applying a voltage of + 25 kV at a temperature of 25 °C, we achieved the simultaneous separation of the studied penicillin derivatives in less then 5 minutes. The separation conditions were optimized and the analytical performance of the method was evaluated in terms of precision, linearity, limit of detection, and quantification. Also, a simple capillary zone electrophoresis method was applied to study the stability of the studied penicillin derivatives in water at different temperatures, using ciprofloxacin hydrochloride as internal standard. It was observed that the extent of the hydrolysis of penicillins in water is highly dependent on the time and also temperature.Estudou-se a aplicabilidade de electroforese capilar para a análise de quatro derivados de penicilina (benzilpenicilina, ampicilina, amoxicilina, oxacilina) amplamente utilizados. Em razão das semelhanças estruturais, o comportamento electroforético destes derivados é muito semelhante e, por conseguinte, a separação eficaz utilizando a electroforese capilar de zona convencional é difícil de ser efetuada. A separação simultânea foi realizada por cromatografia capilar electrocinética micelar, que se baseia na partição diferencial entre os analitos na fase micelar e aquosa. Utilizando-se solução tampão contendo 25 mM de tetraborato de sódio e 100 mM de dodecil sulfato de sódio, como agente tensioativo, com pH de 9,3, voltagem de +25 kV, à temperatura de 25 °C, obteve-se a separação simultânea das penicilinas estudadas em menos de 5 minutos. As condições de separação foram otimizadas e o desempenho do método analítico foi avaliado em termos de precisão, linearidade, limite de detecção e de quantificação. Além disso, aplicou-se método de electroforese capilar de zona simples para estudar a estabilidade de penicilinas em água a diferentes temperaturas, utilizando cloridrato de ciprofloxacino como padrão interno. Estabeleceu-se que o grau de hidrólise de penicilinas em água é altamente dependente do tempo e também da temperatura

Strategic Decision Models Cross-Validation by Use of Decision Reports Information Extraction

From all the events in the life of a business entity, the Mergers and Acquisitions transactions are one of the most challenging ones, as they drastically affect the life of the involved entities, but also their business stakeholders (like clients or suppliers). The Merger transaction can be seen as a growth crisis in the life of the buyer entity and a strive for survival in the life of the acquired company. Studying such transactions are being a constant preoccupation for both academia and practitioners, modeling mergers in order to predict them - one of the most ambitious task. In this paper, we present our technique of cross-validating the results of our model and use several boosting methods for improving the computed decisions scores

Simultaneous determination of amoxicillin and clavulanic acid in pharmaceutical preparations by capillary zone electrophoresis

O ácido clavulânico acentua o espectro antibacteriano de amoxicilina, tornando a maioria dos isolados produtores de β-lactamase sensíveis ao fármaco. Desenvolveu-se um método rápido, simples e eficiente de electroforese capilar (EC) para a determinação simultânea de amoxicilina e de ácido clavulânico a partir de misturas complexas. Usando tetraborato de sódio 25 mM como electrólito em pH de 9,30, voltagem aplicada de + 25 kV, em sistema a 25 ° C e determinação por UV a 230 nm, a foi bem-sucedida a separação simultânea de amoxicilina e ácido clavulânico em, aproximadamente, 2 minutos. O desempenho analítico do método foi avaliado em termos de reprodutibilidade, precisão, exatidão e linearidade. O método analítico otimizado foi aplicado para a determinação dos dois analitos em associação, a partir de preparações farmacêuticas comerciais. Este método de EC é rápido, barato, eficiente e ecologicamente correto, quando comparado aos métodos de cromatografia líquida de alta eficiência mais frequentemente descritos na literatura.Clavulanic acid enhances the antibacterial spectrum of amoxicillin by rendering most β-lactamase producing isolates susceptible to the drug. A fast, simple and efficient capillary electrophoresis method was developed for the simultaneous determination of amoxicillin and clavulanic acid from complex mixtures. Using a 25 mM sodium tetraborate as background electrolyte at a pH of 9.30, + 25 kV applied voltage, 25 °C system temperature, UV determination at 230 nm; we succeeded in simultaneous separation of amoxicillin and clavulanic acid in approximately 2 minutes. The analytical performance of the method was evaluated in terms of reproducibility, precision, accuracy, and linearity. The optimized analytical method was applied for the determination of the two analytes from combined commercial pharmaceutical preparations. This CE method is fast, inexpensive, efficient, and environmentally friendly when compared with the more frequently used high performance liquid chromatography methods described in the literature