Flow-injection amperometry at microfabricated silicon-based μ-liquid–liquid interface arrays

Geometrically regular silicon membrane-based micropore arrays were employed for defined arrays of micrometer-sized interfaces between two immiscible electrolyte solutions (μITIES). These were incorporated into a poly(tetrafluoroethylene) (PTFE) hydrodynamic cell. Electrochemistry at the μITIES array was undertaken following gellification of the organic phase using polyvinyl chloride (PVC) and flowing an aqueous phase over the array surface. Cyclic voltammetric characterization of asymmetric diffusion profiles on either side of the μITIES was accomplished under flowing conditions using positively and negatively charged (TEA+ and 4-OBSA−, respectively) model analyte species. Incorporation of an ionophore (dibenzo-18-crown-6 ether) into the organogel allowed the ion-transfer detection of two oligopeptides (phenylalanine dipeptide and lysine dipeptide) within the available potential window under stationary and flowing conditions.Flow rate studies with TEA+ indicated that the amperometric peak currents do not obey the Levich equation, due to diffusion dominating the mass transport, as opposed to convection. The influence of the applied potential () on the amperometric response of the oligopeptides was studied and hydrodynamic voltammograms (HDVs) for the individual oligopeptides were subsequently constructed. The data presented provide a basis for the use of silicon membrane-based μITIES arrays in flow analytical methods

Elaboración e implantación de un SGI bajo las normas UNE-EN ISO 9001:2008 y UNE-EN ISO 14001:2004 en Construcciones Flores

La empresa Construcciones Flores, frente a la presión del mercado de estandarizar los procesos, está interesada en obtener la certificación ISO 9001 e ISO 14001, obteniendo tras su implantación mejores resultados y aumentando su competitividad. Estas normas internacionales promueven la adopción de un enfoque basado en procesos cuando se desarrolla, implementa y mejora la eficacia de un sistema de gestión de la calidad, para aumentar la satisfacción del cliente mediante el cumplimiento de sus requisitos. Por lo tanto el presente proyecto desarrollará la documentación correspondiente a la implantación de la norma UNE-EN ISO 9001 Y UNE-EN ISO 14001, estableciendo un sistema de gestión de calidad y medioambiental, tanto en las obras que la constructora realice, como en su oficina principal situada en Gorráiz (Navarra). Gracias a un compromiso global de toda la organización se podrá alcanzar el éxito de este proyecto. Para ello la organización establecerá una política y unos objetivos de calidad y medioambientales que se cumplirán a través de los distintos procesos que la empresa lleve a cabo y que previamente serán definidos. Para que esta labor se realice de la mejor manera posible se efectuaran las acciones de mejora y las revisiones necesarias con el fin de demostrar la conformidad del sistema con los requisitos de esta norma internacional.Ingeniería IndustrialIndustria Ingeniaritz

Protocolo de comunicación trabajador-robot mediante imágenes

Curs 2013-2014La idea del proyecto viene del concepto de “fábricas del futuro”, donde las barreras entre robots y humanos se rompen para que la colaboración entre ambos sea como en un equipo. Para la realización de este proyecto se ha utilizado el brazo robótico IRB120 de la marca ABB de 6 Grados de libertad, Matlab y el software Robot Studio. El Objetivo principal de este proyecto es establecer el protocolo de comunicación trabajador-robot mediante imágenes. El trabajador debería poder controlar el robot mediante dibujos realizados en la mesa de trabajo. En el desarrollo de la comunicación trabajador-robot cabe distinguir tres partes: · El análisis y tratamiento de imágenes para el cual se ha utilizado el software Matlab. · Transmisión de los datos desde Matlab al robot. · Programación de las acciones a realizar por el robot mediante el software “Robot Studio”. Con el protocolo de comunicación desarrollado y las imágenes realizadas por el trabajador el robot es capaz de detectar lo siguiente: · la herramienta que debe utilizar (rotulador, boli o ventosa) · si lo que tiene que dibujar en la mesa de trabajo son puntos o trazo continuo. · la localización de los puntos o del trazo continuo en la mesa de trabajo. Se ha alcanzado el objetivo propuesto con éxito, el protocolo de comunicación trabajador-robot mediante imágenes ha sido establecido. Mediante el análisis y tratamiento de imágenes se puede conseguir la información necesaria para que el robot pueda ejecutar las acciones requeridas por el trabajador.The project idea is the concept of "factories of the future" where the barriers between robots and humans break so that the collaboration between them is like a team. For this project we used the robotic arm IRB120 brand ABB with 6 Degrees, Robot Studio and Matlab software. The main objective of this project is to establish the communication protocol worker-robot through images. The worker should be able to control the robot by drawings made on the workbench. For the development of the communication protocol worker-robot three parts can be distinguished: · The analysis and processing of images using “Matlab” software. · Data transmission from Matlab to the robot. · Programming actions to be performed by the robot using the "Robot Studio" software. With the communication protocol developed and the images drawn by the worker the robot is able to detect the following: · the tool to use (pen, marker or vacuum pad) · if the points to draw are continuos or discontinuos · the location of the points to draw. The target has been achieved successfully, the communcation protocol workerrobot through images has been stablished. Through analysis and image processing can get the necessary information so that the robot can perform the actions required by the worker

Electrochemically Induced Formation of Cytochrome c Oligomers at Soft Interfaces

The formation of cytochrome c oligomers was induced at liquid−gel and liquid−liquid interfaces via electroadsorption. At an optimum interfacial potential (Eads=0.975 V), the protein was accumulated at these soft interfaces. It was found that as the concentration of adsorbed protein increased, a single voltammetric peak evolved into double and triple peaks (tads=300 s). Analysis of the protein that accumulated at the interfaces by polyacrylamide gel electrophoresis indicated the presence of oligomeric species, corresponding to dimers (ca. 27 kD), trimers (ca. 35 kD), and even larger species (>250 kD) after prolonged electroadsorption (tads=2 h) at macro-scale soft interfaces. Accordingly, it was possible to electrochemically induce oligomerisation at these soft interfaces, which can be tuned through experimental factors such as interfacial potential difference, electroadsorption time, and bulk solution concentration. These results suggest the use of electrochemistry at soft interfaces as a strategy for the investigation of protein oligomerisation and its inhibition

Ultramicroelectrode Array Based Sensors: A Promising Analytical Tool for Environmental Monitoring

The particular analytical performance of ultramicroelectrode arrays (UMEAs) has attracted a high interest by the research community and has led to the development of a variety of electroanalytical applications. UMEA-based approaches have demonstrated to be powerful, simple, rapid and cost-effective analytical tools for environmental analysis compared to available conventional electrodes and standardised analytical techniques. An overview of the fabrication processes of UMEAs, their characterization and applications carried out by the Spanish scientific community is presented. A brief explanation of theoretical aspects that highlight their electrochemical behavior is also given. Finally, the applications of this transducer platform in the environmental field are discussed

Electrochemically Modulated Liquid-Liquid Extraction of Ionized Drugs under Physiological Conditions

Electrochemically modulated liquid-liquid extraction (EMLLE) enables the selective extraction and separation of ions from mixtures by choice of an applied interfacial potential difference. The extraction of ionized drugs from artificial urine is reported in this paper. The artificial urine matrix was characterized by cyclic voltammetry at the interface between two immiscible electrolyte solutions(ITIES), showing that components of that aqueous phase truncate the available potential window at the ITIES. The transfer of three cationic drugs from aqueous artificial urine to the 1,2-dichloroethane organic electrolyte phase was examined. Both propranolol and timolol were found to transfer across the artificial urine-organic interface.However, sotalol transfer was not possible within the available potential window. Extraction of propranolol and timolol from artificial urine into an organogel phase, by electrochemically modulated liquid-liquid extraction, was examined. The application of potentials positive of the drugs’ formal transfer potentials enabled the selective extraction of both propranolol and timolol, with a higher potential being required for timolol. This work demonstrates the practical utility of EMLLE for the selective extraction of target compounds from a complex samp matrix

Electrochemical detection of dopamine using arrays of liquid–liquid micro-interfaces created withinmicromachined silicon membranes

The detection of protonated dopamine by differential pulse voltammetry (DPV) and square wave voltammetry (SWV) at arrays of micro-interfaces between two immiscible electrolyte solutions (ITIES) is presented. Microfabricated porous silicon membranes (consisting of eight pores, 26.6min radius and 500mpore–pore separation, in a hexagonal layout) were prepared by photolithographic and etching procedures. The membrane pores were fabricated with hydrophobic internal walls so that the organic phase filled the pores and created the liquid interface at the aqueous side of the membrane. These were used for harnessing the benefits of three-dimensional diffusion to the interface and for interface stabilisation.The liquid–liquid interface provides a simple method to overcome the major problem in the voltammetric detection of dopamine at solid electrodes due to the co-existence of ascorbate at higher concentrations. Selectivity for dopamine over ascorbatewas achieved by the use of dibenzo-18-crown-6 (DB18C6) for the facilitated ion transfer of dopamine across the ITIES array. Under these conditions, the presence of ascorbate in excess did not interfere in the detection of dopamine and the lowest concentration detectable was ca. 0.5M. In addition, the drawback of current signal saturation (non-linear increase of the peak current with the concentration of dopamine) observed at conventional (millimetre-sized) liquid–liquid interfaces was overcome using the microfabricated porous membrane