Coupled Extraction/Re-Extraction Method for the Chemical Speciation of Nickel in NaturalWaters

Chemical fractionation and speciation of metals species in natural waters and its relation with bioavailability have received increased attention in recent years. A simple liquid membranes method, based on coupled liquid extraction and re-extraction processes, is proposed to separate and quantify the species of nickel present in water samples. A simplex optimization of chemical variables, such as carrier concentration in the organic solution and nitric acid concentration in the receiving solution, was performed and, under optimized conditions, the extraction system was applied to determine nickel species in water samples at natural level concentrations. A linear relationship was established between extraction e cacy and the concentration of dissolved organic carbon in the samples, allowing the separation and determination of labile and non-labile nickel fractions, since the latter was not transported through the organic solution acting as liquid membrane. When the total and labile concentrations of metals were analyzed in real samples with di erent salinities, no significant di erences were found between the results obtained and those from well-established methods. An average relative error of 1.50 and 2.37 was obtained for total Ni concentration and labile fraction, respectively. Finally, a comparison with the theoretical speciation data calculated with the softwareWinHumic V was successfully performed. Thus, the proposed method allows the simultaneous determination of labile and non-labile nickel fractions, presented as a simple alternative to nickel fractionation in natural waters

Se busca Geobibliotecario: los datos geográficos entran en la biblioteca

The increased proliferation and accessibility of geographic data are changing the landscape of services based on geographic information. From the analysis of recent job offers posted in American university libraries, we discuss what could be the role of the information professional in this new context, with respect to the management and dissemination of geographic data collections, looking for synergies for mutual benefit between academic libraries and their information professionals and the geographic data community that uses geographic information systems (GIS). In fact, this activity would be one more among the data curation or data sets preservation tasks needed currently in many disciplines.La mayor proliferación y accesibilidad de los datos geográficos están cambiando el panorama de servicios basados en información geográfica. A partir del análisis de recientes ofertas de trabajo en bibliotecas universitarias americanas se analiza cuál podría ser el rol del profesional de la información en este nuevo contexto, en cuanto a la gestión y difusión de las colecciones de datos geográficos, identificando sinergias para beneficio mutuo entre las bibliotecas universitarias con sus profesionales de la información y la comunidad que usa datos geográficos y sistemas de información geográfica (SIG). De hecho esta actividad sería una más, un caso particular, de las de curación de datos que se reclama para muchas disciplinas

Resultados funcionales postquirúrgico evaluados con la escala Quick Dash en pacientes sometidos a cirugía de desinserción del ligamento transverso del carpo en el Hospital Militar Escuela Dr. Alejandro Dávila Bolaños en el periodo comprendido de Enero 2016 – Diciembre 2016

El presente estudio descriptivo-transversal retrospectivo realizado en 42 pacientes con diagnóstico de síndrome del túnel del carpo moderado a severo durante enero a diciembre del 2016 en el Hospital Militar Escuela Dr Alejandro Davila Bolanos de la ciudad de Managua, Nicaragua, para conocer los resultados funcionales postquirúrgico evaluados con la escala Quick Dash en pacientes sometidos a cirugía de desinserción del ligamento transverso del carpo. Se intervinieron quirúrgicamente 42 pacientes, en los cuales se utilizó la técnica de cirugía abierta para la sección del ligamento Anular mediante la desinserción de la fascia transversa del carpo, a los cuales se les dio seguimiento por 12 meses, para después evaluar la efectividad del resultado funcional de la técnica quirúrgica, por medio de la escal Quick Dash. El 100 % de los pacientes presentaron un resultado funcional satisfactorio en la intervención quirúrgica de cirugía abierta. El sexo más afectado fue el femenino con 78.3 % de los pacientes. La edad con mayor frecuencia de afección fue el comprendido intervalo de 40.5 años, con mayor incidencia de los maestros 40.5% con resultados de electromiografía moderados en un 57.1% mano derecha dominante 85.7%, con un tiempo quirúrgico de 16 minutos, con resultados de discacidad leve en el 100% casos postquirurgicos Las complicaciones encontradas fueron deshicencia del sitio quirurgico Se concluyó que hay un resultado satisfactorio catalogado como excelente hasta en un 91%, y que el sexo femenino con una edad entre 40.5 años y que trabajen en ocupaciones que exigen movimientos repetitivos de flexión y extensión de la muñeca, tiene una incidencia aumentada de presentar el síndrome del túnel del carpo. La edad promedio de la población estudiada presento una media de 40.5 años

A Green Method for the Determination of Cadmium in Natural Waters Based on Multi-Fibre Supported Liquid Membranes

Supported liquid membranes have been used to implement a hollow fibre liquid-phase microextraction (HF-LPME) method for the preconcentration of Cd(II) in natural waters as a sample preparation step for its determination by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GFAAS). This system was designed to use four hollow fibres simultaneously with the same sample, thus improving the simplicity, speed and reproducibility of the results. The organic liquid membrane bis-(2,4,4-trimethylpentyl) phosphinic acid (Cyanex® 272) dissolved in dihexylether (DHE) was immobilised into the pores of the walls of polypropylene hollow fibres. After extraction, the cadmium-enriched acidic phases were recovered and analysed by triplicate. To optimise the extraction process, the effect of both physical and chemical variables was studied, and optimum results with an enrichment factor (EF) of 292 were obtained for a fibre length of 6 cm, 1.06 M Cyanex 272, 0.04 M HNO3, stirring rate of 600 rpm and an extraction time of 4.26 h. For practical applications, extraction time was reduced to 2 h, keeping the EF as high as 130. Under these conditions, a detection limit of 0.13 ng L-1 Cd(II) was obtained, with a reproducibility of 3.3 % and a linear range up to 3 ug L-1 being achieved. The proposed method was successfully applied to the determination of cadmium in mineral, tap and seawater samples

Advances in ionic liquids and deep eutectic solvents-based liquid phase microextraction of metals for sample preparation in Environmental Analytical Chemistry

Liquid phase micro-extraction (LPME) of metals has showed its potential for sample preparation in environmental analysis. In particular, the incorporation of ionic liquids to LPME (IL-LPME) has gotten increasing interest due to their unique properties as organic salts liquid at room temperature. In the last years, IL-LPME of metals has evolved to more efficient and selective extraction methods thanks to the development of task specific ionic liquids, and deep eutectic solvents. ILs have been implemented in the main LPME modalities: SDME, DLLME and HFLPME, resulting in new versions of these techniques. In this review we have analyzed and discussed the latest developments done in IL-LPME of metals, their advantages and limitations, as well as the potential fields of future development. © 2021 The Author(s). Published by Elsevier B.V.This work has been supported by Spanish Ministry of Economy and Competitiveness through the research project PGC2018- 101894-B-I00. BHS also thanks the Spanish Ministry of Education, Culture and Sports for the pre-doctoral grant FPU15/03924 and the University of Cadiz for the post-doctoral grant 2019-011/PU/ AY.PUENTE/CD

A semi-supervised learning approach to study the energy consumption in smart buildings

IEEE Symposium Series on Computational Intelligence (IEEE SSCI 2021), 05/12/2021-07/12/2021.In this work, we use the semi-supervised LAMDA-HSCC algorithm for characterizing the energy consumption in smart buildings, which can work with labeled and unlabeled data. Particularly, it uses the LAMDA-RD approach for the clustering problem and the LAMDA-HAD approach for the classification problem. Additionally, this algorithm uses three submodels for merging, partition groups (classes/cluster) and migrating individuals from a group to another. For the performance evaluation, several datasets of energetic consumption are used, with different percent of labeled data, showing very encouraging results according to two metrics in the semi-supervised context.European CommissionAgencia Estatal de InvestigaciónJunta de Comunidades de Castilla-La Manch

A multi-label approach for diagnosis problems in energy systems using LAMDA algorithm

2022 IEEE International Conference on Fuzzy Systems (FUZZ-IEEE), 18-23 July 2022, Italia.In this paper, we propose a supervised multilabel algorithm called Learning Algorithm for Multivariate Data Analysis for Multilabel Classification (LAMDA-ML). This algorithm is based on the algorithms of the LAMDA family, in particular, on the LAMDA-HAD (Higher Adequacy Grade) algorithm. Unlike previous algorithms in a multi-label context, LAMDA-ML is based on the Global Adequacy Degree (GAD) of an individual in multiple classes. In our proposal, we define a membership threshold (Gt), such that for all GAD values above this threshold, it implies that an individual will be assigned to the respective classes. For the evaluation of the performance of this proposal, a solar power generation dataset is used, with very encouraging results according to several metrics in the context of multiple labels.European CommissionAgencia Estatal de InvestigaciónJunta de Comunidades de Castilla-La Manch

Elementos Básicos de un Proyecto de Urbanización

El urbanismo ha llegado a alcanzar en la actualidad una importancia en el desarrollo y progreso de las ciudades. Su influencia manifiesta en la estética como en las finanzas y en el desenvolvimiento social de los conglomerados. En lo económico, valorizando terrenos, habitándolos para la construcción .El proyecto mismo implica la circulación del capital, y su realización y futuro desarrollo motivaran un movimiento económico que redundara en positivo provecho. Socialmente, su influencia se manifiesta en la elevación del nivel cultural y Standard higiénico de vida. La urbanización no se circunscribe únicamente a las ciudades y a sus alrededores, si no que va más allá y llega a las fincas y haciendas a construir las urbanizaciones rurales en formas de colonias rurales. En los tiempos modernos, la parte estética es tan importante que algunas veces se sacrifica la economía para alcanzar efectos estéticos deseados. Puede que la mitad del éxito de un proyecto esta en la belleza del diseño, la cual se manifiesta en el trazado y localización de calles, en la ubicación y forma de las plazas, áreas de recreo y en el plan de edificació

Geo-librarian wanted: geographic data come to the library

The increased proliferation and accessibility of geographic data are changing the landscape of services based on geographic information. From the analysis of recent job offers posted in American university libraries, we discuss what could be the role of the information professional in this new context, with respect to the management and dissemination of geographic data collections, looking for synergies for mutual benefit between academic libraries and their information professionals and the geographic data community that uses geographic information systems (GIS). In fact, this activity would be one more among the data curation or data sets preservation tasks needed currently in many disciplines

A liquid micro-extraction based one-step method for the chemical fractionation of copper in seawater

In this work, the reagent Cyanex® 272 has been incorporated in a three-phase solvent bar micro-extraction system to selectively separate the inorganic and organic fractions of copper in seawater. Optimized conditions for micro-extraction of Cu fractions were 0.2 M Cyanex® 272 in the organic solution contained into the fiber pores, 0.5 M HCl as acceptor solution within the fiber, stirring rate of 500 rpm, and 60 min time of extraction, providing an enrichment factor of 51.6 ± 2.3. Experimental results for selective extraction of organic and inorganic Cu showed a good correlation with theoretical data for Cu speciation, and the relationship between enrichment factor and dissolved organic carbon (DOC) concentration in the samples was used to predict total Cu concentration. Instrumental determination of Cu presented a linear response within the range 0.1–20 µg L−1, obtaining a limit of detection of 0.03 µg L−1. Finally, the method was successfully applied to the study of Cu fractions in real seawater samples collected from the Bay of Cádiz (Spain). © 2022 The AuthorsThe authors want to acknowledge the Spanish Ministry of Science and Innovation for the financial support of the project PGC2018-101894-B-I00 the FPU grant FPU15/03924 , and the ERASMUS + program for the grant received by Ibstissem Belbachir, which allowed her research stay at the University of Cádiz