Thermodynamic analysis of unimer-micelle and sphere-to-rod micellar transitions of aqueous solutions of sodium dodecylbenzenesulfonate

Temperature dependence of specific conductivity of sodium dodecylbenzenesulfonate (NaDBS) aqueous solutions was analyzed. Two breaks on the plot appeared for all temperature, which suggest two micellar transitions. This has been corroborated by surface tension measurements. The first transition concentration occurs at the critical micelle concentration (CMC), whilst the second critical concentration (so-called transition micellar concentration, TMC) is due to a sphere-to-rod micelles transition. The dependence of CMC and TMC on the temperature allows the computation of the corresponding thermodynamic functions: Gibbs free energy, enthalpy and entropy changes. For the CMC, enthalpy and entropy increments were found that decrease with the temperature values. However, an anomalous behavior was obtained for the TMC, where both ΔS0 and ΔH0 values raised with the temperature increase. However, for both transitions, an (enthalpy + entropy) compensation is observed. These results will be compared with similar systems reported in the literature

Modelado de TCP en un entorno celular con dual connectivity

This paper proposes a TCP implementation in a system-level simulator. This LTE-Advanced simulator provides Dual Connectivity (DC), which allows user equipments (UEs) to receive data simultaneously from two evolved NodeBs (eNBs) in order to boost the performance in a heterogeneous network. In this work, a TCP abstraction is described to predict TCP version Reno performance in an accurate and computationally efficient way. The proposed model is used to show the impact of DC on the user throughput and dropped packets when UEs are downloading a file through TCP.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Effects of 12 weeks of whole body vibration vs. multi-component training in postmenopausal women

The aims of this study were to analyze the effects of two different training protocols (vibratory platform and multi-component training) and to determine what kind of training creates greater adaptations on bone density, and isokinetic strength of the knee extensors and the stabilizer muscles of the ankle joint in postmenopausal women. Thirty-eight women (59.8 ± 6.2 years) were randomly assigned to whole body vibration group (WBVG), multi-component training group (MTG), or a control group (CG). The experimental groups performed an incremental training for 12 weeks, 3 sessions/week. Significant differences were found in total fat mass and total lean mass in the training groups. In addition, both WBVG and MTG showed significant increases in isokinetic strength for knee extensors at 60º·s-1 and at 270º·s-1 . With respect to ankle joint, a significant increase for eversion at 60º·s-1 and inversion at 60º·s-1 was found in both the training groups, and eversion at 120º·s-1 only in WBVG (p = 0.012). There were no significant differences between WBVG and MTG in knee and ankle strength tests. Therefore, we have found significant adaptations to whole body vibration and multi-component training in the present study. However, the improvements were similar for both groups and we cannot claim that WBVG is better than MTG, or viceversaActividad Física y Deport

Structural and magnetic characterization of ordered Sr2LnSbO6 (Ln=rare earth) perosvkite

The double perovskites A2LnMO6 (A = Sr2+ and Ba2+; Ln = trivalent lanthanide cation; M = pentavalent 4d or 5d transition elements) have been widely studied concerning their structure and properties [1]. If the Ln and M cations are ordered within the B-perosvkite sites the symmetry and size of the unit cell change when are compared to the ideal cubic aristotype. Woodward predicted 15 possible space groups for the ordered A2BB’O6 perovskites when the cation ordering and the octahedral tilting around the pseudo-cubic axes take place simultaneously [2]. The ordered double perovskites A2LnMO6 with only one of the two B-sites carrying magnetic moment, namely Ln, show a magnetic sublattice consisting of edge-sharing tetrahedral, which represents a frustrating magnetic geometry in three dimensions. More recently, the structure of double perovskites Sr2LnSbO6 (Ln= Dy, Ho, Gd, Y and In) has been investigated, and the monoclinic symmetry of the space group P21/n, with Ln and Sb elements ordered in the B-sites, was reported [3, 4]. We report the preparation of the whole family of double perovskites Sr2LnSbO6 (Ln = La-Lu), which crystallize with the P21/n space group, with lattice parameters p= a2a , p= a2b and p= a2c(β∼90 º), being the lattice parameter of the cubic aristotype. A progressive decreasing was observed in lattice parameters with the increasing of the atomic number of the Ln cation, according with the wellknown lanthanide contraction. pa Magnetic susceptibility measurements for this family of compounds reveal a paramagnetic behaviour in a very wide temperature range. From experimental spectroscopic data as well as from a semi-empirical estimation (Simple Overlap Model SOM [5]) of the crystal-field parameters corresponding to the point site symmetry of the magnetically active Ln, Oh, and using the wavefunctions associated with the energy levels obtained, the paramagnetic susceptibility and its evolution vstemperature is simulated according to the van Vleck formalism. The observed deviation from the Curie–Weiss behaviour at low temperature, very well reproduced in each case, reflects the splitting of the ground state of the corresponding Ln cation under the influence of the crystal field. Thus, magnetic frustration or cooperative interactions do not need to be considered to explain the mentioned low temperature deviation from the linearity of Curie-Weiss plots

Online Anomaly Detection System for Mobile Networks

The arrival of the Fifth-Generation (5G) standard has further accelerated the need for operators to improve the network capacity. With this purpose, mobile network topologies with smaller cells are being currently deployed to increase the frequency reuse. In this way, the number of nodes that collect performance data is being further risen, so the amount of metrics to be managed and analyzed is being highly increased. Therefore, it is fundamental to have tools that automate these tasks and inform the network operator of the relevant information within the vast amount of metrics collected. In this manner, it is particularly important the continuous monitoring of the performance indicators and the automatic detection of anomalies for network operators to prevent the network degradation and users’ complaints. Therefore, in this paper a methodology to detect and track anomalies in the mobile networks performance indicators in real time is proposed. The feasibility of this system is evaluated with several performance metrics and a real LTE-Advanced dataset. In addition, it is also compared with the performance of other state-of-the-art anomaly detection systems

Electrodes based on nafion and epoxy-graphene composites for improving the performance and durability of open cathode fuel cells, prepared by electrospray deposition

Fabrication of electrodes for polymer electrolyte fuel cells is a intriguing process in which a balance between gas transport, electrical conductivity, proton transport and water managing must be optimized. In this work four different electrodes prepared by electrospray deposition have been studied using different catalytic inks, in which Nafion and epoxy doped with Graphene-Nanoplatelets were used as binders. After studying the behavior of those electrodes in a single open cathode fuel cell proton electrolyte membrane, it is clear that the addition of epoxy as binder doped with graphene, improves the performance of the fuel cell and increase the mechanical stability of the electrode avoiding the loose of catalyst during the electrode manipulation in the fuel cell assembly process and the durability of the fuel cell. To explain this behavior, an ex-situ study was carried out, in which properties such as its surface morphology, hydrophobicity and electrical and thermal conductivity of those electrodes were studied. From the results of this study, such improvement in the performance of the fuel cell was justified on the basis of the increase in the electrical conductivity, a diminution in its thermal conductivity and an enhancement of hydrophobicity (surface morphology) of the deposited catalyst layer, when an optimum quantity of epoxy is added to the catalytic ink that makes to improve the mechanical properties of those electrodesAJN and MAG are actually working on this project with a contract funded by the Comunidad Atonoma de la Región de Murcia, Conserjería de Desarrollo Económico, Turismo y Empleo, and the European Union, through the program RIS3- MUR, grant number 2I20SAE00079. This work has also been funded by the Spanish Ministry of Science and Innovation (AEI, Spain,PID2020-112744GB-I00/AEI/10.13039/501100011033 and RTI2018-095844-B-I00), Fundacion Seneca (Región de Murcia, Spain), grant number: 20985/PI/18 and Agencia estatal española de Investigación, grant number PID2019-104272RBC55/AEI/10.13039/501100011033. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper

Distributed deep reinforcement learning resource allocation scheme for industry 4.0 Device-To-Device scenarios

This paper proposes a distributed deep reinforcement learning (DRL) methodology for autonomous mobile robots (AMRs) to manage radio resources in an indoor factory with no network infrastructure. Hence, deep neural networks (DNN) are used to optimize the decision policy of the robots, which will make decisions in a distributed manner without signalling exchange. To speed up the learning phase, a centralized training is adopted in which a single DNN is trained using the experience from all robots. Once completed, the pre-trained DNN is deployed at all robots for distributed selection of resources. The performance of this approach is evaluated and compared to 5G NR sidelink mode 2 via simulations. The results show that the proposed method achieves up to 5% higher probability of successful reception when the density of robots in the scenario is high.This work has been partially funded by Junta de Andalucía (projects EDEL4.0:UMA18-FEDERJA-172 and PENTA:PY18-4647) and Universidad de Málaga (I Plan Propio de Investigación, Transferencia y Divulgación Científica). Ramoni Adeogun is supported by the Danish Council for Independent Research, grant no. DFF 9041-00146B. The authors would like to express their profound gratitude to Nokia Standardization Aalborg and Aalborg University for funding the first author’s research stay. The authors thank Assoc. Prof. Gilberto Beradinelli for his comments on the manuscript

A New Solid Phase Extraction for the Determination of Anthocyanins in Grapes

A method for the concentration and cleaning of red grape extracts prior to the determination of anthocyanins by UPLC-DAD has been developed. This method is of special interest in the determination of phenolic maturity as it allows the analysis of the anthocyanins present in grapes. Several different SPE cartridges were assessed, including both C-18- and vinylbenzene-based cartridges. C-18-based cartridges presented a very low retention for the glucosylated anthocyanidins while vinylbenzene-based cartridges showed excellent retention for these compounds. The optimized method involves the initial conditioning of the cartridge using 10 mL of methanol and 10 mL of water, followed by loading of up to 100 mL of red grape extract. Ten mL of water was used in the washing step and anthocyanins were subsequently eluted using 1.5 mL of acidified methanol at pH 2. This method simplifies the determination of individual anthocyanins as, on the one hand, it cleans the sample of interference and, on the other hand, it increases the concentration to up to 25:1.5. The developed method has been validated with a range of different grapes and it has also been tested as a means of determining the different anthocyanins in grapes with different levels of maturity

Método de posicionamiento de drones LTE-5G para compensación de fallos en situaciones de emergencia

The failures resulting from cells outages or the partial loss of communications infrastructures make it impossible to serve users in the affected area. Such services would allow them to establish communication in order to get help or provide additional information about the situation to the emergency services. To solve this problem, a compensation method based on a drone deployment is proposed to be used in emergency situations. The proposed algorithm determines the position and power configuration of the drones to cover the affected area. To test and evaluate the effectiveness of the system, the throughput offered in the network after the deployment of the drones is analyzed and compared with a uniform distribution of drones.Este trabajo ha sido financiado por la Junta de Andalucía (Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Proyecto de Excelencia PENTA, P18-FR-4647) y a través del II Plan Propio de Investigación y Transferencia de la Universidad de Málaga. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The crystal structure of the TolB box of colicin A in complex with TolB reveals important differences in the recruitment of the common TolB translocation portal used by group A colicins

Interaction of the TolB box of Group A colicins with the TolB protein in the periplasm of Escherichia coli cells promotes transport of the cytotoxic domain of the colicin across the cell envelope. The crystal structure of a complex between a 107-residue peptide (TA1–107) of the translocation domain of colicin A (ColA) and TolB identified the TolB box as a 12-residue peptide that folded into a distorted hairpin within a central canyon of the β-propeller domain of TolB. Comparison of this structure with that of the colicin E9 (ColE9) TolB box–TolB complex, together with site-directed mutagenesis of the ColA TolB box residues, revealed important differences in the interaction of the two TolB boxes with an overlapping binding site on TolB. Substitution of the TolB box residues of ColA with those of ColE9 conferred the ability to competitively recruit TolB from Pal but reduced the biological activity of the mutant ColA. This datum explains (i) the difference in binding affinities of ColA and ColE9 with TolB, and (ii) the inability of ColA, unlike ColE9, to competitively recruit TolB from Pal, allowing an understanding of how these two colicins interact in a different way with a common translocation portal in E. coli cells