Esterification of Free Fatty Acids with Glycerol within the Biodiesel Production Framework

Companies in the field of the collection and treatment of waste cooking oils (WCO) for subsequent biodiesel production usually have to cope with high acidity oils, which cannot be directly transformed into fatty acid methyl esters due to soap production. Since glycerine is the main byproduct of biodiesel production, these high acidity oils could be esterified with the glycerine surplus to transform the free fatty acids (FFA) into triglycerides before performing the transesterification. In this work, commercial glycerol was esterified with commercial fatty acids and commercial fatty acid/lampante olive oil mixtures over tin (II) chloride. In the first set of experiments, the esterification of linoleic acid with glycerol excess from 20 to 80% molar over the stoichiometric was performed. From 20% glycerol excess, there was no improvement in FFA reduction. Using 20% glycerol excess, the performance of a biochar obtained from heavy metal-contaminated plant roots was compared to that of SnCl2. Then, the effect of the initial FFA content was assessed using different oleic acid/lampante olive oil mixtures. The results illustrated that glycerolysis was impeded at initial FFA contents lower than 10%. Finally, the glycerolysis of a WCO with 9.94% FFA was assayed, without success

Estimating Software Testing Complexity

Context: Complexity measures provide us some information about software artifacts. A measure of the difficulty of testing a piece of code could be very useful to take control about the test phase. Objective: The aim in this paper is the definition of a new measure of the difficulty for a computer to gen erate test cases, we call it Branch Coverage Expectation (BCE). We also analyze the most common com plexity measures and the most important features of a program. With this analysis we are trying to discover whether there exists a relationship between them and the code coverage of an automatically generated test suite. Method: The definition of this measure is based on a Markov model of the program. This model is used not only to compute the BCE, but also to provide an estimation of the number of test cases needed to reach a given coverage level in the program. In order to check our proposal, we perform a theoretical val idation and we carry out an empirical validation study using 2600 test programs. Results: The results show that the previously existing measures are not so useful to estimate the difficulty of testing a program, because they are not highly correlated with the code coverage. Our proposed mea sure is much more correlated with the code coverage than the existing complexity measures. Conclusion: The high correlation of our measure with the code coverage suggests that the BCE measure is a very promising way of measuring the difficulty to automatically test a program. Our proposed measure is useful for predicting the behavior of an automatic test case generator.This work has been partially funded by the Spanish Ministry of Science and Innovation and FEDER under contract TIN2011-28194 (the roadME project

Enriched lower separation axioms and the principle of enriched continuous extension

[EN] This paper presents a version of the lower separation axioms and the principle of enriched continuous extension for quantale-enriched topological spaces. As a remarkable result, among other things, we point out that in the case of commutative Girard quantales the principle of continuous extension holds for projective modules in Sup.The authors acknowledge support from the Basque Government (grant IT1483-22). The first named author also acknowledges support from a postdoctoral fellowship of the Basque Government (grant POS-2022-1-0015)

Validación Inteligente para la Sincronización de Semáforos Basada en Feature Models

El concepto de Smart City o Ciudad Inteligente engloba el conjunto de acciones y servicios, basados en las tecnologías de información y comunicación, que se ofrecen en un núcleo urbano. En este sentido, el uso de técnicas bioinspiradas para la gestión del flujo del tráfico mediante la sincronización de semáforos podría constituir uno de los aspectos más innovadores en los entornos urbanos en el futuro. No obstante, la programación automática de semáforos requiere además de un proceso de validación de las soluciones generadas, dado que afectan a la seguridad de miles de usuarios. En este trabajo se propone una estrategia de validación basada en los Modelos de Características (Feature Models) para generar automáticamente diversos escenarios para la comprobación de la robustez de los programas de semáforos. Como caso de estudio, se realiza la validación de programas de semáforos en el área urbana de la ciudad de Málaga, generados mediante cuatro algoritmos de optimización (PSO, DE, Random Search y SCPG). El resultado es información validada sobre el programa de semáforos que mejor actúa para un mayor porcentaje de situaciones de tráfico diferentes.Ministerio de Economía y Competitividad y FEDER: TIN2011-28194, BES-2012-055967 y BES-2009-01876

A linear assisted switching envelope amplifier for a UHF polar transmitter

Spectrally efficient wireless communication standards impose stringent linearity specifications, which would require traditional IQ transmitters to operate with back-offed and power inefficient linear RF power amplifiers (PAs). In order to overcome such a significant limitation, alternative architectures have been proposed, as those based on the envelope elimination and restoration technique. An example of the application of this technique is the polar transmitter. In this paper, a UHF polar transmitter is presented, combining switching and linear stages in the envelope amplifier as to achieve both wide bandwidth and high efficiency, when drain modulating a GaN HEMT Class E RF PA. Several tests, using EDGE, TETRA, and WCDMA standards have been performed with good results.This work was supported by the Spanish Ministries MICINN and MINECO through the FEDER cofunded Project TEC2011-29126-C03-01, Consolider Project CSD2008-00068, Consolider Project RUECSD2009-00046, and Project DPI2010-21110-C02-01

Clinic and Health of Captive and Free-living Odontocetes and Pinnipeds

Los océanos albergan el 71% de la superficie terrestre. Tal es su magnitud que, desde tiempos inmemoriales, el ser humano ha establecido multitud de vínculos con él y sus habitantes. Los mamíferos marinos, tales como odontocetos y pinnípedos, se han convertido en recursos biológicos fundamentales. Es por ello que el bienestar y la conservación de estos animales deben suponer una prioridad para el hombre, en su afán por seguir aprendiendo sobre el medio marino. La metodología empleada en la elaboración del presente artículo ha supuesto una revisión sistemática de la documentación científica más relevante acerca del tema de estudio.Las enfermedades infecciosas son consideradas la principal causa de patología en estos animales. Entre los agentes víricos de mayor impacto destacan los géneros Poxvirus y Herpesvirus. El género bacteriano Brucella y los nematodos de la familia Anisakidae son conocidos por protagonizar las mayores epizootias en ambos grupos de mamíferos marinos.Este trabajo pretende constituir la primera guía de aproximación acerca de las principales patologías infecciosas y aspectos clínicos de mayor impacto en odontocetos y pinnípedos, estableciendo una clara distinción entre aquellos que se encuentran en estado salvaje y los que viven en medios controlados.The 71 % of the Earth surface is covered with water. Such is its importance that from mankind beginning on, human being has been linked to it and its inhabitants. This way, marine mammals as odontocets and pinnipeds has become highly necessary biological resources for entertainment and environmental education. That is why the wellbeing and habitat of these species must be a priority for mankind as far as we keep on learning about sea life. Overall scientific research has been methodologically revised in this report. Infectious diseases are well known to be the main cause of disorder in these animals. The most viral agents in this kind of infections are the Poxvirus and Herpesvirus genera. The bacteria Brucella spp and the Anisakidae family of nematodes are known to be liable to bring about the major epizootic diseases in both marine mammals groups.Ciencias Experimentale

Start-Up of Chitosan-Assisted Anaerobic Sludge Bed Reactors Treating Light Oxygenated Solvents under Intermittent Operation

Quality of the granular sludge developed during the start-up of anaerobic up-flow sludge bed reactors is of crucial importance to ensure the process feasibility of treating industrial wastewater such as those containing solvents. In this study, the microbial granule formation from suspended-growth biomass was investigated in two chitosan-assisted reactors. These reactors operated mimicking industrial sites working with night closures treating a mixture of ethanol, ethyl acetate, and 1-ethoxy-2-propanol. Each reactor operated under different hydrodynamic regimes typical from UASB (R1: 90%) accompanied by rapid formation of robust anaerobic granules were achieved at both up-flow velocity levels. After three weeks from the start-up, mean size diameters of 475 µm and 354 µm were achieved for R1 and R2, respectively. The performance of the process was found to be stable for the whole operational period of 106 days treating intermittent OLR up to 13 kg COD m−3 d−1. A memory dose of chitosan at day 42 was beneficial to guarantee good quality of the granules by offsetting the negative impact of intermittent water supply on the granular size. Methanocorpusculum was identified as the dominant archaea at both up-flow velocities. Acetobacterium, Geobacter and Desulfovibrio bacteria were also abundant, demonstrating its role on the degradation of light-oxygenated solvents

Hybrid Machine Learning Models for Classifying Power Quality Disturbances: A Comparative Study

The economic impact associated with power quality (PQ) problems in electrical systems is increasing, so PQ improvement research becomes a key task. In this paper, a Stockwell transform (ST)-based hybrid machine learning approach was used for the recognition and classification of power quality disturbances (PQDs). The ST of the PQDs was used to extract significant waveform features which constitute the input vectors for different machine learning approaches, including the K-nearest neighbors’ algorithm (K-NN), decision tree (DT), and support vector machine (SVM) used for classifying the PQDs. The procedure was optimized by using the genetic algorithm (GA) and the competitive swarm optimization algorithm (CSO). To test the proposed methodology, synthetic PQD waveforms were generated. Typical single disturbances for the voltage signal, as well as complex disturbances resulting from possible combinations of them, were considered. Furthermore, different levels of white Gaussian noise were added to the PQD waveforms while maintaining the desired accuracy level of the proposed classification methods. Finally, all the hybrid classification proposals were evaluated and the best one was compared with some others present in the literature. The proposed ST-based CSO-SVM method provides good results in terms of classification accuracy and noise immunity

Factibilidad del uso de polvillo del alto horno para mejorar material tipo base granular

1 recurso en línea (171 páginas) : ilustraciones, tablas, figuras.En este proyecto de investigación se estudia la factibilidad del uso de polvillo de alto horno para estabilizar bases granulares; el proyecto se encuentra dirigido por el Ingeniero Ricardo Ochoa Díaz, docente de la escuela de Ingeniería de Transporte y Vías de la Universidad Pedagógica y Tecnológica de Colombia. Para el desarrollo del proyecto se utilizó un agregado proveniente de la cantera San Rafael localizada en la vereda San Isidro del municipio de Cómbita, Boyacá y como estabilizante se usó el polvillo de alto horno proveniente de Acerías Paz del Río S.A., ubicada en el Municipio de Nobsa, Boyacá. Para caracterizar los materiales, se realizaron los ensayos estipulados en las especificaciones del INVÍAS 2013 y se logró determinar que el agregado no cumplía con los criterios de índice de plasticidad y resistencia (CBR). Luego se realizaron las mezclas con los diferentes porcentajes de polvillo (2%, 4%, 6%, 8% y 10%); a estas mezclas se les hicieron los ensayos de límites y resistencia (CBR); finalmente se determinó el porcentaje óptimo de polvillo. Con los resultados obtenidos de las mezclas con los diferentes porcentajes de polvillo, se analizó si el material presentaba alguna mejora en cuanto a resistencia (C BR), expansión y límites. También se realizó la comparación de la mezcla sin polvillo y con polvillo optimo en el ensayo de estabilidad volumétrica. Se calcularon los estados tensionales de un modelo estructural, con el fin de comparar el espesor de la capa de base sin estabilizar y la capa de base estabilizada con polvillo. Por último, se realizó un análisis económico comparando una base sin estabilizar vs una base estabilizada.Bibliografía y webgrafía: páginas 129-130PregradoIngeniero de Transport

Dealing with inheritance in OO evolutionary testing.

Most of the software developed in the world follows the object-oriented (OO) paradigm. However, the existing work on evolutionary testing is mainly targeted to procedural languages. All this work can be used with small changes on OO programs, but object orientation introduces new features that are not present in procedural languages. Some important issues are polymorphism and inheritance. In this paper we want to make a contribution to the inheritance field by proposing some approaches that use the information of the class hierarchy for helping test case generators to better guide the search. To the best of our knowledge, no work exists using this information to propose test cases. In this work we de¯ne a branch distance for logical expressions containing the instanceof operator in Java programs. In addition to the distance measure, we propose two mutation operators based on the distance. We study the behaviour of the mutation operators on a benchmark set composed of nine OO programs. The results show that the information collected from the class hierarchy helps in the search for test cases