Anaerobic co-digestion of municipal sewage sludge and fruit/vegetable waste: effect of different mixtures on digester stability and methane yield

There are different options for the management of fruit and vegetable wastes (FVWs), but the most environmental-friendly is the anaerobic digestion, because it allows an optimum recovery of materials and energy from the two by-products: biogas and digestate. Nevertheless, in many cases there are economic and technical problems that cause the selection of other alternatives. Frequently these wastes are produced in large quantities but only during few weeks of the year. In these cases, this is the most important economic problem, because large digesters that would be used only for short time periods every year would be required. In addition, a close control of the pH of the digester is required for this kind of residues, for which the hydrolysis is usually faster than the methanogenesis, so large concentrations of fatty acids should be prevented to maintain the adequate pH value for anaerobic digestion that should be neutral or slightly alkaline. Both problems can be simultaneously overcome by the co-digestion with other residues that are produced throughout the year. Among the benefits of co-digestion, one of the most important is the improvement in the feedstock characteristics, since it may allow a more equilibrate composition resulting in a better performance of the digester in treatment capacity, and a better quality of biogas and digestate. The co-digestion with other substrates with a complementary composition that are produced throughout the year and that are already managed by anaerobic digestion is probably the optimum management option. For these cases, if the existing anaerobic digester is oversized and allows the introduction of additional volumes of wastes, the mean retention time of the digestate should be maintained. Therefore, the anaerobic co-digestion of fruit and vegetable waste (FVW) and municipal sewage sludge (MSS) under mesophilic condition and a constant hydraulic retention time (20 d) is studied. The effects on digester performance of the FVW:MSS ratio and the organic loading rate (OLR) were examined. The OLR is the mass of volatile solids fed per volume of digestate and day.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Benchmarking Object Detection Deep Learning Models in Embedded Devices

Object detection is an essential capability for performing complex tasks in robotic applications. Today, deep learning (DL) approaches are the basis of state-of-the-art solutions in computer vision, where they provide very high accuracy albeit with high computational costs. Due to the physical limitations of robotic platforms, embedded devices are not as powerful as desktop computers, and adjustments have to be made to deep learning models before transferring them to robotic applications. This work benchmarks deep learning object detection models in embedded devices. Furthermore, some hardware selection guidelines are included, together with a description of the most relevant features of the two boards selected for this benchmark. Embedded electronic devices integrate a powerful AI co-processor to accelerate DL applications. To take advantage of these co-processors, models must be converted to a specific embedded runtime format. Five quantization levels applied to a collection of DL models are considered; two of them allow the execution of models in the embedded general-purpose CPU and are used as the baseline to assess the improvements obtained when running the same models with the three remaining quantization levels in the AI co-processors. The benchmark procedure is explained in detail, and a comprehensive analysis of the collected data is presented. Finally, the feasibility and challenges of the implementation of embedded object detection applications are discussed.This work has received support from the following programs: PID2019-104966GB-I00 (Spanish Ministry of Science and Innovation), IT-1244-19 (Basque Government), KK-2020/00049, KK-2021/00111 and KK-2021/00095 (Elkartek projects 3KIA, ERTZEAN and SIGZE, funded by the SPRI-Basque Government) and the AI-PROFICIENT project funded by European Union’s Horizon 2020 research and innovation program under grant agreement no. 9573

Days out of role due to common physical and mental conditions in Portugal: results from the WHO World Mental Health Survey

Funding: The Portuguese Mental Health Study was carried out by the Department of Mental Health, NOVA Medical School, NOVA University of Lisbon, with collaboration of the CESOP – Portuguese Catholic University and was funded by the Champalimaud Foundation, the Gulbenkian Foundation, the Foundation for Science and Technology (FCT) and the Ministry of Health. The Portuguese Mental Health Study was carried out in conjunction with the World Health Organization WMH Survey Initiative which is supported by the National Institute of Mental Health (NIMH; R01 MH070884), the John D. and Catherine T. MacArthur Foundation, the Pfizer Foundation, the U.S. Public Health Service (R13-MH066849, R01-MH069864 and R01 DA016558), the Fogarty International Center (FIRCA R03-TW006481), the Pan American Health Organization, Eli Lilly and Company, OrthoMcNeil Pharmaceutical, GlaxoSmithKline and Bristol-Myers Squibb.publishersversionpublishe

Light up that Droid! On the Effectiveness of Static Analysis Features against App Obfuscation for Android Malware Detection

Malware authors have seen obfuscation as the mean to bypass malware detectors based on static analysis features. For Android, several studies have confirmed that many anti-malware products are easily evaded with simple program transformations. As opposed to these works, ML detection proposals for Android leveraging static analysis features have also been proposed as obfuscation-resilient. Therefore, it needs to be determined to what extent the use of a specific obfuscation strategy or tool poses a risk for the validity of ML malware detectors for Android based on static analysis features. To shed some light in this regard, in this article we assess the impact of specific obfuscation techniques on common features extracted using static analysis and determine whether the changes are significant enough to undermine the effectiveness of ML malware detectors that rely on these features. The experimental results suggest that obfuscation techniques affect all static analysis features to varying degrees across different tools. However, certain features retain their validity for ML malware detection even in the presence of obfuscation. Based on these findings, we propose a ML malware detector for Android that is robust against obfuscation and outperforms current state-of-the-art detectors

Learning contract, co-operative and flipped learning as useful tools for studying metabolism

Es el Abstract de una comunicación a un congreso internacional sobre educaciónUndergraduate students in Biology identify Metabolic Biochemistry as a particularly difficult subject. This is due to the fact that students need to interconnect properly all the contents of its syllabus throughout their study of the subject in order to get a global insight of the complex regulatory features controlling metabolic pathways within the metabolic network under different physiologic and pathologic conditions, as well as metabolism as a whole. Due to these objective difficulties, a high percentage of our students face the study of this subject as a very hard task beyond their forces and capacities. This perception leads to high rates of premature dropout. In previous years, less than 40% of all the registered students attended the examinations of Metabolic Biochemistry (a subject in the second year of the Degree of Biology at our University). Even worse, less than 25% of our students passed the exams. From the academic year 2015/16 on, we are developing innovative teaching projects (PIE15-163 and PIE17-145, funded by University of Malaga) aimed to increase our student loyalty to the subject (and hence to increase their attendance to exams) and to help them to learn more effectively metabolism and its regulation. These innovative teaching projects are based on the use of several powerful tools: a learning contract and problem-based learning within the framework of group tasks promoting an actual collaborative learning in a flipped classroom. The present communication will show the implementation of the PIE15-163 and PIE17-145 projects and some results obtained from them.This work was supported by Malaga University funds granted to the educational innovation project PIE17-145. The attendance to the END2018 International Conference on Education and New Developments (June 2018, Budapest, Hungary) has received a grant from "I Plan Propio Integral de Docencia. Universidad de Málaga"]

Reducing complexity in tree-like computer interconnection networks

Abstract The fat-tree is one of the topologies most widely used to build high-performance parallel computers. However, they are expensive and difficult to build. In this paper we propose two alternative tree-like topologies that are cheaper in terms of cost and complexity, because they are "thinner" than fat-trees: less switches, and less links. We test the performance of these narrowed trees, and compare it with that of the full-fledged fat-tree using a collection of synthetic patterns that emulate the behavior of well-known applications, including causal relationships among messages. Moreover, we do a performance/cost analysis of these networks. Our main conclusion is that, for the set of studied applications, performance of narrowed topologies is as high as that of fat-trees, with much less cost. Rearranging switch ports to use them as downward ports instead of upward ports do reduce bisection bandwidth, but also increases locality, which can be efficiently exploited by applications

Co-digestion of mixed sewage sludge and fruit and vegetables wastes effect of different mixtures on biogas yield

Disposal of fruit and vegetable wastes (FVWs) in landfill site cause serious environmental issues such as contamination of soil, air and ground water. These wastes contain large quantities of biodegradable organic fractions, with high moisture that facilitates their biological treatment. One of the best alternatives to landfill disposal of these wastes is the anaerobic digestion. Therefore, it is one of the most widespread stabilization processes of the sludge in municipal wastewater treatment plants (WWTP). Introduction of FVW in WWTP and co-digestion with mixed sludge (MS) could enhance biogas production and plant economic feasibility. A lab-scale experiment for the anaerobic co-digestion of FVW and municipal mixed sludge under mesophilic condition and 20 days hydraulic retention time is investigated. Initially the digester was fed with mixed sludge (MS) from wastewater treatment plants with an average organic loading rate (OLR) of 0.63 (g L–1 d–1). The co-digestion of mixed sludge and FVW was performed at various organic loading ratios (OLRs), between 0.63 and 5.5 (g L–1 d–1). The experimental specific biogas and methane productions are 0.656 L g–1 and 0.340 L g–1 respectively. Alkalinity and pH remains relatively constant regardless the introduction of different proportions of FVW in the mixture. Co-digestion, compared with the digestion of MS as single substrate, improves the biogas and methane production.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

New Perspectives for Electrodialytic Remediation

Electrodialytic remediation has been widely used for the recovery of different contaminants from numerous matrices, such as, for example, polluted soils, wastewater sludge, fly ash, mine tailing or harbour sediments. The electrodialytic remediation is an enhancement of the electrokinetic remediation technique, and it consists of the use of ion-exchange membranes for the control of the acid and the alkaline fronts generated in the electrochemical processes. While the standard electrodialytic cell is usually built with three-compartment configuration, it has been shown that for the remediation of matrices that require acid environment, a two-compartment cell has given satisfactory removal efficiencies with reduced energy costs. Recycling secondary batteries, with growing demand, has an increasing economic and environmental interest. This work focusses on the proposal of the electrodialytic remediation technique as a possible application for the recycling of lithium-ion cells and other secondary batteries. The recovery of valuable components, such as lithium, manganese, cobalt of phosphorous, based on current recycling processes and the characterization of solid waste is addressed.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045. Paz-Garcia acknowledges the financial support from the University of Malaga, project: PPIT.UMA.B5.2018/17. Villen-Guzman acknowledges the funding from the University of Malaga for the postdoctoral fellowship PPIT.UMA.A.3.2.2018. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Electrodialytic Recovery of Cobalt from Spent Lithium-Ion Batteries

Contribución en congreso científicoRecycling lithium-ion batteries has an increasing interest for economic and environmental reasons. Disposal of lithium-ion batteries imposes high risk to the environment due to the toxicity of some of their essential components. In addition to this, some of these components, such as cobalt, natural graphite and phosphorus, are included in the list of critical raw materials for the European Union due to their strategic importance in the manufacturing industry. Therefore, in the recent years, numerous research studies have been focused on the development of efficient processes for battery recycling and the selective recuperation of these key components. LiCoO2 is the most common material use in current lithium-ion batteries cathodes. In the current work, an electrodialytic method is proposed for the recovery of cobalt from this kind of electrode. In a standard electrodialytic cell, the treated matrix is separated from the anode and the cathode compartments by means of ion-exchange membranes. A cation-exchange membrane (CEM) allows the passage of cations and hinders the passage of anions, while the behaviour of anion-exchange membrane (AEM) does the opposite. A three-compartment electrodialytic cell has been designed and assembled, as depicted in the figure. In the central compartment, a suspension of LiCoO2 is added. Different extracting agents, such as EDTA, HCl and HNO3, are tested to enhanced the dissolution and the selective extraction of the target metal. Dissolved cobalt-containing complexes migrate towards the cathode or the anode compartments depending on the ionic charge of the complexes. While cobalt extraction via extracting agents is an expensive treatment, as it requires the constant addition of chemicals, an efficient electrodialytic cell could allow the recirculation of the extracting agents and the economical optimization of the process.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 778045. Paz-Garcia acknowledges the financial support from the University of Malaga, project: PPIT.UMA.B5.2018/17. Villen-Guzman acknowledges the funding from the University of Malaga for the postdoctoral fellowship PPIT.UMA.A.3.2.2018. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec