Análisis de vibraciones con radar Doppler: determinación de los modos de vibración de una placa rectangular

El trabajo que aquí se presenta describe un método de análisis de vibraciones no perturbativo basado en un radar doppler. El objetivo principal es diseñar un sistema (hardware y software) capaz de analizar vibraciones de forma precisa, remotamente y que no suponga un elevado coste económico, y su aplicación en la determinación de los modos de vibración de una placa de aluminio rectangular libre. El interés de esta aplicación radica principalmente en los campos de la industria y de la ingeniería, y en la necesidad de medir vibraciones en ambientes en los que resultaría imposible con los métodos clásicos: entornos ruidosos, ausencia de atmósfera... En primer lugar se estudian los diferentes métodos de análisis de vibraciones, la necesidad de un método como el que aquí se presenta y su fundamento. Después se exponen los resultados obtenidos hasta la fecha para la determinación de los modos propios de vibración de la placa. En siguiente lugar se diseña e implementa el instrumento de medida y se realizan las mediciones considerando excitaciones en el dominio del tiempo y de la frecuencia, analizando las diferencias entre dos radares de distintas bandas de frecuencia y presentando una alternativa instrumental de fácil adquisición. Finalmente se muestran los resultados y las conclusiones.Grado en Físic

Highly fluorescent complexes with 3-isocyanoperylene and N-(2,5-di-tert-butylphenyl)-9-isocyano-perylene- 3,4-dicarboximide

Producción CientíficaThe perylene derivatives 3-isocyanoperylene (Per–N≡C) (4a) and N-(2,5-di-tert-butylphenyl)- 9-isocyano-perylene-3,4-dicarboximide (PMI–N≡C) (4b) were prepared and used to synthesize gold complexes [AuX(CNR)] (X = C6F5 (5a,b), C6F4-OnBu-p (6b)). The reaction of 5b and 6b with HNEt2 led the carbene complexes [AuX{C(NEt2)(NHR)}] (7b, 8b), respectively. The molecular structure of complexes 7b, 8b have been determined by X-ray diffraction analysis showing intermolecular π–stacking of the perylene groups and C6F5 rings, and no Au···Au interactions. The derivative compounds [M(CO)5(CNR)] (M = Cr (9a,b), Mo (10a,b) or W (11a,b)) and trans-[Pd(CNR)2(C6F3Cl2)2] (12a,b) were also prepared. All complexes exhibit fluorescence associated to the perylene fragment with emission quantum yields, in solution at room temperature, in the range 0.05 – 0.93 and emission lifetimes ~ 4 ns. DFT calculations were performed of the absorption spectra of the ligands Per–N≡C and PMI–N≡C, and representative complexes [Au(C6F5)(CNR)], [Cr(CO)5(CNR)], showing a perylene-dominated intraligand π–π*emissive state, from the HOMO and LUMO orbitals of the perylene chromophore, but with significantly different absorption maxima by influence of the metal fragment, particularly significant in the Per–N≡C derivatives.Ministerio de Economía, Industria y Competitividad (CTQ2011-2513)Ministerio de Economía, Industria y Competitividad (CTQ2011-23862-C02)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA302U13)Generalitat de Catalunya (grant 2009SGR-1459

The New Youth of the In Situ Transmission Electron Microscopy

The idea of in situ transmission electron microscopy (TEM) and its possible ramifications were proposed at the very dawn of electron microscopy, but the translation from theory to practice encountered many technological setbacks, which hindered the feasibility of the most elaborated approaches until recent times. However, the several technological improvements achieved in the last 10–15 years filled this gap, allowing the direct observation of the dynamic response of materials to external stimuli under a vast range of conditions going from vacuum to gaseous or liquid environment. This resulted in a blossoming of the in situ TEM and scanning TEM (STEM) techniques to a new youth for a vast, growing range of applications, which cannot be rightfully detailed in a short span; therefore, this chapter should be intended as a guide highlighting a selection of the most inspiring, recently achieved results

Direct protein quantification in complex sample solutions by surface-engineered nanorod probes

Detecting biomarkers from complex sample solutions is the key objective of molecular diagnostics. Being able to do so in a simple approach that does not require laborious sample preparation, sophisticated equipment and trained staff is vital for point-of-care applications. Here, we report on the specific detection of the breast cancer biomarker sHER2 directly from serum and saliva samples by a nanorod-based homogeneous biosensing approach, which is easy to operate as it only requires mixing of the samples with the nanorod probes. By careful nanorod surface engineering and homogeneous assay design, we demonstrate that the formation of a protein corona around the nanoparticles does not limit the applicability of our detection method, but on the contrary enables us to conduct in-situ reference measurements, thus further strengthening the point-of-care applicability of our method. Making use of sandwich assays on top of the nanorods, we obtain a limit of detection of 110 pM and 470 pM in 10-fold diluted spiked saliva and serum samples, respectively. In conclusion, our results open up numerous applications in direct protein biomarker quantification, specifically in point-of-care settings where resources are limited and ease-of-use is of essenceThis research was supported by the European Commission FP7 NAMDIATREAM project (EU NMP4-LA-2010–246479), and the German Research Foundation (DFG grant PA 794/25-1)S

Homogeneous Biosensing Based on Magnetic Particle Labels

The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation

Steady-State heat transfer through micro-channels in pressurized He II

The operation of the Large Hadron Collider superconducting magnets for current and high luminosity future applications relies on the cooling provided by helium-permeable cable insulations. These insulations take advantage of a He II micro-channels network constituting an extremely efficient path for heat extraction. In order to provide a fundamental understanding of the underlying thermal mechanisms, an experimental setup was built to investigate heat transport through single He II channels typical of the superconducting cable insulation network, where deviation from the macro-scale theory can appear. Micro-fabrication techniques were exploited to etch the channels down to a depth of ~ 16 μm. The heat transport properties were measured in static pressurized He II and analyzed in terms of the laminar and turbulent He II laws, as well as in terms of the critical heat flux between the two regions

Cu2Se and Cu Nanocrystals as Local Sources of Copper in Thermally Activated in Situ Cation Exchange

Among the different synthesis approaches to colloidal nanocrystals, a recently developed toolkit is represented by cation exchange reactions, where the use of template nanocrystals gives access to materials that would be hardly attainable via direct synthesis. Besides, postsynthetic treatments, such as thermally activated solid-state reactions, represent a further flourishing route to promote finely controlled cation exchange. Here, we report that, upon in situ heating in a transmission electron microscope, Cu2Se or Cu nanocrystals deposited on an amorphous solid substrate undergo partial loss of Cu atoms, which are then engaged in local cation exchange reactions with Cu “acceptor” phases represented by rod- and wire-shaped CdSe nanocrystals. This thermal treatment slowly transforms the initial CdSe nanocrystals into Cu2−xSe nanocrystals, through the complete sublimation of Cd and the partial sublimation of Se atoms. Both Cu “donor” and “acceptor” particles were not always in direct contact with each other; hence, the gradual transfer of Cu species from Cu2Se or metallic Cu to CdSe nanocrystals was mediated by the substrate and depended on the distance between the donor and acceptor nanostructures. Differently from what happens in the comparably faster cation exchange reactions performed in liquid solution, this study shows that slow cation exchange reactions can be performed at the solid state and helps to shed light on the intermediate steps involved in such reactions

High-Fidelity Power Injection From A Fuel Cell Onto A Variable-Frequency AC Power Bus

Synchronization of DC-source fed inverters to AC power systems is essential to the integration of DC sources such as fuel cells, batteries, and photovoltaics. In many cases, a phase detector determines the angle of the system which is used in the inverter control for the synchronization; however, there may be errors in the phase detection as a result of a trade-off between harmonic filtering and response time of the detector. These errors may propagate through the control to the output of the inverter and increase harmonic content or degrade the inverter\u27s dynamic response. Such trade-offs are especially significant in highly variable-frequency systems where the phase-detector response time may be critical. Variable-frequency power systems exist in isolated power systems with low inertia such as microgrids and ships, and on aircraft due to the main generators being directly coupled to the aircraft jet turbines. While the frequency in most isolated power systems may vary +/-15% from the nominal 50 or 60Hz, aircraft power systems may vary as much as 380-800Hz in only a few seconds. In this work, a new method of phase detection is proposed to reduce phase errors in variable-frequency systems through a feed-forward technique. The proposed method is compared with existing phase detectors both in simulation and through hardware evaluation and is verified to be superior in its dynamic response. Additionally, it is demonstrated that phase-detection errors may be reduced by inverter control structure configurations. Finally, the variable-frequency aircraft power system under study is combined with a fuel-cell fed DC to AC inverter in simulation and a small-signal stability study using Lyapunov\u27s indirect method is performed. The results demonstrate that the fuel cell, or any other DC-source, impedance and the inverter controller has a direct effect on the system small-signal stability

Desarrollo de una aplicación móvil mediante React-Native

In this document has been developed an application to share food recipes with social format where the users can interact between them. The goal of this applications is to create a global platform when users wants to find something related with cooking, know where have to go and don't have to use a web browser. All has developed with React-Native that allows to develop native applications for Android and IOS platforms, and reduce the processing time respect to hybrid applications. Also, the code is useful for both platforms, this suppose reduction of cost and time. The application includes the database and the backend developed with MongoDB and Node.JS respectively. Also includes a little business model to have an idea where the application can be situated in a real environment. A real user test, where they use the application for the first time, this helped to find possible issues and is a way to know how improve the application because you can see how the interaction is. And finally the next steps to improve the application in th