A high aspect ratio Fin-Ion Sensitive Field Effect Transistor: compromises towards better electrochemical bio-sensing

The development of next generation medicines demand more sensitive and reliable label free sensing able to cope with increasing needs of multiplexing and shorter times to results. Field effect transistor-based biosensors emerge as one of the main possible technologies to cover the existing gap. The general trend for the sensors has been miniaturisation with the expectation of improving sensitivity and response time, but presenting issues with reproducibility and noise level. Here we propose a Fin-Field Effect Transistor (FinFET) with a high heigth to width aspect ratio for electrochemical biosensing solving the issue of nanosensors in terms of reproducibility and noise, while keeping the fast response time. We fabricated different devices and characterised their performance with their response to the pH changes that fitted to a Nernst-Poisson model. The experimental data were compared with simulations of devices with different aspect ratio, stablishing an advantage in total signal and linearity for the FinFETs with higher aspect ratio. In addition, these FinFETs promise the optimisation of reliability and efficiency in terms of limits of detection, for which the interplay of the size and geometry of the sensor with the diffusion of the analytes plays a pivotal role.Comment: Article submitted to Nano Letter

Estudio del patrón de flujo en un modelo de bifurcación con obstáculos transversales

En este trabajo fin de grado se estudia el patrón de flujo en un modelo de bifurcación, en la que se han introducido una serie de obstáculos transversales. El estudio se realiza en la zona de la bifurcación y en una zona aguas arriba de esta donde se encuentra un obstáculo. A modo comparativo se realiza el estudio con los resultados de una bifurcación sin obstáculosDepartamento de Ingeniería Energética y FluidomecánicaGrado en Ingeniería Mecánic

Miniaturized Control of Acidity in Multiplexed Microreactors

The control of acidity drives the assembly of biopolymers that are essential for a wide range of applications. Its miniaturization can increase the speed and the possibilities of combinatorial throughput for their manipulation, similar to the way that the miniaturization of transistors allows logical operations in microelectronics with a high throughput. Here, we present a device containing multiplexed microreactors, each one enabling independent electrochemical control of acidity in ∼2.5 nL volumes, with a large acidity range from pH 3 to 7 and an accuracy of at least 0.4 pH units. The attained pH within each microreactor (with footprints of ∼0.3 mm2 for each spot) was kept constant for long retention times (∼10 min) and over repeated cycles of >100. The acidity is driven by redox proton exchange reactions, which can be driven at different rates influencing the efficiency of the device in order to achieve more charge exchange (larger acidity range) or better reversibility. The achieved performance in acidity control, miniaturization, and the possibility to multiplex paves the way for the control of combinatorial chemistry through pH- and acidity controlled reactions

Dalia, una maestra viajera. La escuela rural durante el franquismo

El trabajo pretende realizar un estudio de la escuela rural durante el franquismo, utilizando una historia de vida, la de Dalia Viñau, que ejerció durante 46 años, la mayor parte de ellos durante el régimen político de Franco, instaurado al final de la Guerra Civil española. El estudio abarca una trayectoria histórica de la legislación educativa desde la Constitución de 1812, centrándolo en la zona del Alto Aragón, personalizándolo en la figura de una maestra emblemática. Sus recuerdos y los testimonios de sus alumnos de entonces, su escuela y su vida constituyen el medio para recrear un ejemplo de la profesión en el mundo rural.<br /

Simulation of Marine Towing Cable Dynamics Using a Finite Elements Method

A numerical model to study the towing maneuver for floating and submerged bodies has been developed. The proposed model is based on the dynamic study of a catenary line moving between two bodies, one body with imposed motion, and the other free to move. The model improves previous models used to study the behavior of mooring systems based on a finite element method by reducing the noise of the numerical results considering the Rayleigh springs model for the tension of the line. The code was successfully validated using experimental results for experimental data from different authors and experiments found in the literature. Sensitivity analysis on the internal damping coefficient and the number of elements has been included in the present work, showing the importance of the internal damping coefficient. As an example of the application of the developed tool, simulations of towing systems on a real scale were analyzed for different setups. The variation of the loads at the towed body and the position of the body were analyzed for the studied configurations. The reasonable results allow us to say that the proposed model is a useful tool with several applications to towing system design, study or optimizationThe authors are grateful to the Spanish Ministry of Economy, Industry and Competitiveness for funding ACOPLE- Analysis of the dynamic behavior of floating wind platforms for design optimization in deep waters (ENE2017-89716-R), within the National Programme for Research, Development and Innovation Aimed at the Challenges of Society (Call 2017). Raúl Guanche also acknowledges financial support from the Ramon y Cajal Program (RYC-2017-23260) of the Spanish Ministry of Science, Innovation and Universities

Bluejay: A Cross-Tooling Audit Framework For Agile Software Teams

Agile software teams are expected to follow a number of specific Team Practices (TPs) during each iteration, such as estimating the effort ("points") required to complete user stories and coordinating the management of the codebase with the delivery of features. For software engineering instructors trying to teach such TPs to student teams, manually auditing teams if teams are following the TPs and improving over time is tedious, time-consuming and error-prone. It is even more difficult when those TPs involve two or more tools. For example, starting work on a feature in a project-management tool such as Pivotal Tracker should usually be followed relatively quickly by the creation of a feature branch on GitHub. Merging a feature branch on GitHub should usually be followed relatively quickly by deploying the new feature to a staging server for customer feedback. Few systems are designed specifically to audit such TPs, and existing ones, as far as we know, are limited to a single specific tool. We present Bluejay, an open-source extensible platform that uses the APIs of multiple tools to collect raw data, synthesize it into TP measurements, and present dashboards to audit the TPs. A key insight in Bluejay's design is that TPs can be expressed in terminology similar to that used for modeling and auditing Service Level Agreement (SLA) compliance. Bluejay therefore builds on mature tools used in that ecosystem and adapts them for describing, auditing, and reporting on TPs. Bluejay currently consumes data from five different widely-used development tools, and can be customized by connecting it to any service with a REST API. Video showcase available at governify.io/showcase/blueja

Discovery of Amino Acid fingerprints transducing their amphoteric signatures by field-effect transistors

Protein sequencing is key to many biological fields to advance science and prospect medical applications based on proteomics. However, even with advanced techniques such as mass spectrometry it is hard to detect the fluctuations in AA sequences and optical/geometrical isomers, and cannot provide wide access to ex-novo sequencing of low quantities of proteins. We are presenting a new and disruptive method based on FET sensors for AA/polypeptide detection. We show unique signals (fingerprints) of every single AA and polypeptide mutations by solving the site-binding model self-consistently with the Gouy-Chapman-Stern model. The surface potential (Ψo), 2nd gradient of the surface potential (δΨo2/δpH2) and total surface capacitance (CT) are used as fingerprint signals to differentiate between the amino acids including the drain current variation as the signal transduction. These fingerprints are based on orthogonal properties of the AAs, which are the different proton affinities of each of the radicals, their dielectric constant and effective length, which is sensitive to the relative positions of the radicals to distinguish between isomers. We studied the generation of signals and proposed a novel noise-filtering technique based on the Fast-Fourier Transform (FFT) and the significantly improved analytical model which is solved iteratively to reduce data loss. The minimum combined fingerprint resolution is 0.1 units of pH for the separation of singularities found in δΨo2/δpH2, linked to the minimum capacitance of the AAs with a needed resolution of 0.01mF/m2 for surface densities of 1014cm-2, and which can be normalized to lower densities. The effect of noise (&gt;SNR=10dB) and silanol sites can be negated by correlating the AAs signatures from δΨo2/δpH2 and capacitance. Thus, the designed methodology and approach can help immensely in designing a new and efficient tool for protein sequencing while solving the problems related to the signal transduction of sensors