3,830 research outputs found
Cooling Process Analysis of a 5-Drum System for Radioactive Waste Processing
A cooling system design for the processing of radioactive waste drums is investigated in
this work, with the objective of providing insights for the determination of the air flow rate required
to ensure an acceptable slag temperature (323 K or below) after 5 days. A methodology based
on both 3D and 2D axisymmetric Computational Fluid Dynamics (CFD) modelling is developed.
Transient temperature distributions within the drums in time and space determined by the heat
transfer characteristics are studied in detail. A sensitivity analysis is also carried out assuming
different physical properties of the radioactive slag. It was found out that for all variations analyzed,
the maximum temperature of slag at the end of five days cooling is below 323 K, where the maximum
outlet air temperature for a minimum air inlet velocity of 1 m/s is between 320 K and 323 K
depending on the radioactive slag properties. When glass-like radioactive slag properties are assumed,
the internal heat conduction within the slag is limiting the overall heat transfer, therefore requiring
significantly longer cooling times
Alcohol decomposition on basic/acid lignin-derived submicron diameter carbon fibers
The use of lignin, the second most abundant polymer in nature, along with a simple and versatile
technique, electrospinning, represents an advantageous and promising approach for the preparation of
carbon fibers. In previous studies, we have demonstrated that the incorporation of H3PO4 to the initial
lignin solution allows for shortening the carbon fibers preparation process and that the resulting carbon
fibers present P-surface groups that are of great interest for heterogeneous catalysis.
Different carbon fibers catalysts have been prepared by electropinning of Alcell lignin in the absence or
presence of H3PO4 as chemical activating agent. Carbonization at different temperatures between 500
and 1600 ÂşC allows for preparing carbon fibers with a high variety of porosity and chemical surface
properties. Diverse oxygen surface groups are presented on the carbon catalysts surface. The
isopropanol decomposition has been used as a catalytic test to study the acid or basic character of the
prepared carbon fibers. Carbon fibers without phosphorus surface groups generate acetone as the main
product of the isopropanol decomposition reaction, from 400 to 600 ÂşC, suggesting the basic character
of these catalysts. On the contrary, phosphorus-containing carbon fibers show high acid character,
producing selectivity to propylene of 100 % at temperatures between 250 and 350 ÂşC. The most acid
carbon fiber catalyst produced a high selectivity to ethylene and dimethyl ether for the decomposition of
ethanol and methanol, respectively. The conversion enhancement that the presence of oxygen in the gas
phase produced for all these reactions was also studied.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech.
MINECO (CTQ2015-68654-R).
MINECO (PTA2015-11464-I)
Scalable Inference of Gene Regulatory Networks with the Spark Distributed Computing Platform Cristo
Inference of Gene Regulatory Networks (GRNs) remains an important open challenge in computational biology. The goal of bio-model inference is to, based on time-series of gene expression data, obtain the sparse topological structure and the parameters that quantitatively understand and reproduce the dynamics of biological system. Nevertheless, the inference of a GRN is a complex optimization problem that involve processing S-System models, which include large amount of gene expression data from hundreds (even thousands) of genes in multiple time-series (essays). This complexity, along with the amount of data managed, make the inference of GRNs to be a computationally expensive task. Therefore, the genera- tion of parallel algorithmic proposals that operate efficiently on distributed processing platforms is a must in current reconstruction of GRNs. In this paper, a parallel multi-objective approach is proposed for the optimal inference of GRNs, since min- imizing the Mean Squared Error using S-System model and Topology Regularization value. A flexible and robust multi-objective cellular evolutionary algorithm is adapted to deploy parallel tasks, in form of Spark jobs. The proposed approach has been developed using the framework jMetal, so in order to perform parallel computation, we use Spark on a cluster of distributed nodes to evaluate candidate solutions modeling the interactions of genes in biological networks.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech
En el filo de la navaja : biocombustibles y mercado global de cereales
La importancia pra la poblaciĂłn de esta fuente de nutrientes supone, en cuanto al valor en el mercado, una lĂnea roja difĂcil de sortear. Por ello, su aprovechamiento como combustible natural deberá mirarse con lupa para evitar un impacto dañino sobre la demanda y las existencia
A New Multi-Objective Approach for Molecular Docking Based on RMSD and Binding Energy
Ligand-protein docking is an optimization problem based on predicting the position of a ligand with the lowest binding energy in the active site of the receptor. Molecular docking problems are traditionally tackled with single-objective, as well as with multi-objective approaches, to minimize the binding energy. In this paper, we propose a novel multi-objective formulation that considers: the Root Mean Square Deviation (RMSD) difference in the coordinates of ligands and the binding (intermolecular) energy, as two objectives to evaluate the quality of the ligand-protein interactions. To determine the kind of Pareto front approximations that can be obtained, we have selected a set of representative multi-objective algorithms such as NSGA-II, SMPSO, GDE3, and MOEA/D. Their performances have been assessed by applying two main quality indicators intended to measure convergence and diversity of the fronts. In addition, a comparison with LGA, a reference single-objective evolutionary algorithm for molecular docking (AutoDock) is carried out. In general, SMPSO shows the best overall results in terms of energy and RMSD (value lower than 2A for successful docking results). This new multi-objective approach shows an improvement over the ligand-protein docking predictions that could be promising in in silico docking studies to select new anticancer compounds for therapeutic targets that are multidrug resistant.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech
Flexible and low-cost binderless capacitors based on p- and n-containing fibrous activated carbons from denim cloth wastes
Activated carbon cloths have been prepared from denim cloth wastes (DCWs) through chemical
activation with H3PO4. The effect of the H3PO4/DCWs impregnation ratio and the carbonization
temperature on the porous texture, the chemical composition, the fibers morphology, and the
electrochemical performance has been studied. Low H3PO4/DCWs impregnation ratios lead to flexible
and microporous activated carbons cloths, whereas more fragile and rigid activated carbon cloths with
higher external surface area are produced upon increasing the amount of H3PO4. The increase in the
carbonization temperature allows for obtaining a more ordered and conductive carbon structure. The
activated carbon prepared at 900 ÂşC with a H3PO4/DCWs impregnation ratio of 0.5 (w/w) exhibits the
best performance as electric double layer capacitor. This electrode shows a specific surface area of
2016 m2 g-1 and the highest registered gravimetric capacitance (227 F g-1). Moreover, its flexibility
minimizes the ohmic resistance of the electrode, thus increasing the feasibility of working at higher
current densities than the other synthesized electrodes.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech; MINECO CTQ2015-68654-
Cara a cara ante los limites del conocimiento
ÂżPuede el ser humano asimilar la larga lista de importantes hallazgos cientĂficos que se suceden cada dĂa? ÂżComo puede asumir Ă©ticamente tal vĂ©rtigo? ÂżSe puede pensar sin estar atento a avances como la secuenciaciĂłn del Genoma Humano o la ingenierĂa genĂ©tica? Los profesores JosĂ© Manuel Sánchez Ron, catedrático de Historia de la Ciencia de la Universidad AutĂłnoma de Madrid, y Francisco GarcĂa Olmedo, catedrático de BiologĂa Molecular de la Universidad PolitĂ©cnica, hablan sobre estos interrogantes en un momento en el que se cuestionan valores asumidos durante milenios. Ambos publican estos dĂas, respectivamente, El futuro es un paĂs tranquilo (Espasa) y Entre el placer y la necesidad (CrĂtica)
Bioqueries: a collaborative environment to create, explore and share SPARQL queries in Life Sciences
Bioqueries provides a collaborative environment to create, explore, execute, clone and share SPARQL queries (including Federated Queries). Federated SPARQL queries can retrieve information from more than one data source.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech
An integration of non-destructive techniques (SFM-GPR-TLS) as a virtual tool for archaeological strategy: the case of the roman site of the plaza de la MorerĂa in Sagunto (Spain)
9th International Congress & 3rd GEORES - GEOmatics and pREServation-ARQUEOLĂ“GICA 2.0 : Valencia (Spain).
26–28 April 2021In this article, we present a methodology involving a combination of structure from motion (SFM) photogrammetry, ground
penetrating radar (GPR) and terrestrial laser scanner (TLS), georeferenced on the same reference frame defined by
topographic methods. We show that this simultaneous integration of non-destructive techniques (NDTs) and analysis of
archaeological data constitutes a highly effective approach for archaeological research strategies. As an example of the
applicability of this framework, we discuss in detail the archaeological research (1991, 2002 and 2018 campaigns) at a
Roman site, the Plaza de la MorerĂa, located in the urban area of the city of Sagunto (eastern Spain). The goal of this
research was to design a strategy to recover a pre-1st century AD Roman funerary space, and to assess whether to remove
a 3rd century AD domus pavement covering the funerary remains. We found that our methodology was able to provide an
adaptable and flexible design at each phase of the project. The high resolution of 2D and 3D virtual visualisation features
of the GPR technique made it possible to pinpoint and map the existence of Roman overlapped horizons and buried
structures in the study zone. Therefore, this framework is able to provide a deep understanding of the spatial organisation
and stratigraphic potential, allowing informed decisions about which levels to excavate and which ones to remove. This
feature is extremely significant for the inherent decision-making process in every archaeological research project, thus
opening new perspectives in interventions of location, study, management, conservation and planning in archaeological
heritage research
High temperature treatments of porous activated carbon
The use of biomass waste for the preparation of activated carbon is of great industrial interest for reducing costs and increasing the sustainability, especially in the field of energy storage. A high temperature treatment is required to obtain a more ordered carbon material, thus increasing its conductivity. However, this high temperature treatment entails as a disadvantage a significant reduction in porosity. Therefore, a method to prepare activated carbons with a high porosity development as well as high conductivity could be of great interest for many applications.
The aim of this work is to analyze the possible influence of phosphorus compounds on the physical-chemical properties of different carbon materials thermally treated at relatively high temperatures (1600 ÂşC). With this goal, it has been prepared activated carbons from different precursors (olive stone, lignin and hemp) and different conformations (powder, fibers and monoliths) by physical and chemical activation, with CO2 and H3PO4, respectively.
Once the different activated carbon materials were prepared, they were thermally treated at 1600 ÂşC under inert atmosphere. The different samples were characterized by N2 and CO2 adsorption at 77 and 273 K, respectively, XPS, XRD and Raman techniques. The oxidation resistance was also evaluated in a thermogravimetric balance. High temperature treatments of activated carbon without the presence of P surface groups produced an important contraction of the porosity (from 900 to 150 m2 g-1). However, temperature treatments of phosphorus-activated carbon allowed for preparing carbon materials with a relatively high structural order and a well-developed porosity (c.a. 1100 m2 g-1), with a significant contribution of mesoporosity. These results suggest that these P-surface groups are responsible for the low contraction observed for the porous structure, avoiding, in a large extent, its collapse.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech.
MINECO (CTQ2015-68654-R).
MINECO (PTA2015-11464-I)
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