Analysis of Single Board Architectures Integrating Sensors Technologies

Development boards, Single-Board Computers (SBCs) and Single-Board Microcontrollers (SBMs) integrating sensors and communication technologies have become a very popular and interesting solution in the last decade. They are of interest for their simplicity, versatility, adaptability, ease of use and prototyping, which allow them to serve as a starting point for projects and as reference for all kinds of designs. In this sense, there are innumerable applications integrating sensors and communication technologies where they are increasingly used, including robotics, domotics, testing and measurement, Do-It-Yourself (DIY) projects, Internet of Things (IoT) devices in the home or workplace and science, technology, engineering, educational and also academic world for STEAM (Science, Technology, Engineering and Mathematics) skills. The interest in single-board architectures and their applications have caused that all electronics manufacturers currently develop low-cost single board platform solutions. In this paper we realized an analysis of the most important topics related with single-board architectures integrating sensors. We analyze the most popular platforms based on characteristics as: cost, processing capacity, integrated processing technology and opensource license, as well as power consumption (mA@V), reliability (%), programming flexibility, support availability and electronics utilities. For evaluation, an experimental framework has been designed and implemented with six sensors (temperature, humidity, CO2/TVOC, pressure, ambient light and CO) and different data storage and monitoring options: locally on a µSD (Micro Secure Digital), on a Cloud Server, on a Web Server or on a Mobile ApplicationThis research was partially supported by the Centro Científico Tecnológico de Huelva (CCTH), University of Huelv

An open hardware electronic controller for motorized rotary injection valves used in flow injection analysis

This work presents the design, development and the implementation of a motorized injection valve used in Flow Injection Analysis systems. The built prototype has been developed based on the open hardware, software and firmware, emergent philosophy thus helping the development of a free and independent science. This policy creates a platform of open projects that feed each other, contributing to scientific and technological development while sharing knowledge. The proposed design project can be modified to implant it in other devices or projects according to the needs of each one. Also, the open project can be a great help as teaching material in Universities, since open hardware projects are fully described and documented

Voltammetric behavior of 3,5-dinitrobenzoic acid in solution on GCE and encapsulated on multiwalled carbon nanotube modified electrode

The cyclic voltammetric behavior of 3,5-dinitrobenzoic acid (3,5-DNB) in 0.1 M PBS of pH 7 was examined at a glassy carbon electrode (GCE). 3,5-DNB was found to produce two irreversible reduction peaks corresponds to the reduction of each nitro group in the 3,5-DNB molecule. Our results contradict previous studies (P.Gopal et al. Journal of Molecular Liquids 178 (2013) 168-174) wherein the same peaks are assigned as, the first, to the reduction of the nitro group to hydroxylamine and the second, to the subsequent reduction to amine derivative. Also we report that GCE modified with multiwalled carbon nanotubes (MWCNTs) can be derivatized with 3,5-DNB. The derivatization procedure involves simple immersion of the MWCNT-modified electrode in a solution containing 3,5-DNB. SEM images reveals that the network of nanotubes form a homogeneous, twisted, densely packed, three-dimensional array that remains attached to the GCE surface. Both electrochemical and SEM measurements indicate that 3,5-DNB is encapsulated on the electrode, most probably by being trapped within the pockets of the mentioned three-dimensional array, without formation of covalent bonding

Aspectos fundamentales en el desarrollo de instrumentación electroquímica avanzada : aplicación a medidas de impedancia y espectroelectroquímicas

La electroquímica, más concretamente, la electroquímica electródica es una especialidad claramente diferenciada de la química, con un conjunto completo de teorías y ecuaciones cuantitativas. En muchos aspectos es una de las especialidades máss an tiguas

Inexpensive FIA method to determine trace levels of imazapyr by UV-detection enhanced with electrochemical polarization

A new flow injection analysis method with spectro-electrochemical detection (FIA/SEC) to determine trace levels of imazapyr on water samples is presented. The non-chromatographic method involves the use of a bench photometer, a single-potential potentiostat, a low pressure pumping system and a home-made spectro-electrochemical flow detector (SEC-FD), specifically adapted for the described method and using a stainless steel/electrolytic lead/lead chloride (SS/e-Pb/PbCl2) working electrode. The limit of quantification (LOQ) reached for the optimized work parameters was 0.02 mg/mL, the relative standard deviation (RSD) in the whole range of linear response was less than 2% and a wide linear response range from 0.005 to 6.0 mg/mL was obtained. A standard addition method was used to determine the imazapyr amount in natural waters containing commercial formulation of such herbicide, the Recovery % has values close to 105%. The method performance makes it suitable to analyze the legal imazapyr tolerances established by the U.S. EPA avoiding the use of expensive chromatographic equipments and/or complicated sample preparations.This work was supported by the Research Plan of the University of Huelva

Stereoselective electrochemical reduction of imazapyr in aqueous media without chiral auxiliaries

The electrochemical reduction of imazapyr at the static mercury drop electrode was studied by cyclic voltammetry as a function of pH in aqueous buffered media. The process leads to the 2,3=CvN double bond reduction in the imidazoline moiety in all media. The products have been isolated by controlled-potential electrolyses and identified by high performance liquid chromatography-tandem mass spectrometry measurements and H-1-NMR, C-13-NMR, and IR spectra. Although no chiral auxiliary was used, a moderate diasteroisomeric excess was observed. The diasteromeric ratio depends on pH of the electrolyse