3,809 research outputs found
Polymeric foams as the matrix of voltammetric sensors for the detection of catechol, hydroquinone, and their mixtures
ProducciĂłn CientĂficaPorous electrodes based on polymethylmethacrylate and graphite foams (PMMA_G_F) have been developed and characterized. Such devices have been successfully used as voltammetric sensors to analyze catechol, hydroquinone, and their mixtures. The presence of pores induces important changes in the oxidation/reduction mechanism of catechol and hydroquinone with respect to the sensing properties observed in nonfoamed PMMA_graphite electrodes (PMMA_G). The electropolymerization processes of catechol or hydroquinone at the electrode surface observed using PMMA_G do not occur at the surface of the foamed PMM_G_F. In addition, the limits of detection observed in foamed electrodes are one order of magnitude lower than the observed in the nonfoamed electrodes. Moreover, foamed electrodes can be used to detect simultaneously both isomers and a remarkable increase in the electrocatalytic properties shown by the foamed samples, produces a decrease in the oxidation potential peak of catechol in presence of hydroquinone, from +0.7âV to +0.3âV. Peak currents increased linearly with concentration of catechol in presence of hydroquinone over the range of 0.37·10â3âM to 1.69·10â3âM with a limit of detection (LOD) of 0.27âmM. These effects demonstrate the advantages obtained by increasing the active surface by means of porous structures.Ministerio de EconomĂa, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-67482-R)Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (project VA-011U16
Validating communication network configurations in cloud and HPC systems using Metamorphic Testing
Funding: This work was supported by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with the Complutense University as part of the Program to Stimulate Research for Young Doctors in the context of the V PRICIT (Regional Programme of Research and Technological Innovation) under grant PR65/19-22452, the Spanish MINECO/FEDER project MASSIVE under Grant RTI2018-095255-B-I00, the Comunidad de Madrid project FORTE-CM under grant S2018/TCS-4314, and project S2018/TCS-4339 (BLOQUES-CM) co-funded by EIE Funds of the European Union and Comunidad de Madrid.During the last years, the fast evolution of computers and networks has led to the creation of a wide variety of services that have changed the way we live, like video streaming, on-line gaming and online shopping. These services are supported by complex systems, which require not only high computational power but high-speed and low-latency networks to fulfil the expected quality requirements. However, a misleading configuration in one of the thousand components that compose these systems may cause performance bottlenecks and functioning disruptions. Unfortunately, conventional testing methods are not adequate for checking these systems since, on many occasions, there does not exist a mechanism to determine if the behaviour of a system is the expected one. Fortunately, Metamorphic Testing is a valuable and promising testing technique that alleviates the two fundamental problems of testing: the oracle problem and the reliable test set problem. In this paper, we combine Metamorphic Testing and simulation techniques for validating communication network con- figurations in HPC systems. For this, we rely on a catalogue of Metamorphic Relations, based on network communications knowledge, for checking its correctness. In addition, we have conducted an experimental study for analysing the communica- tion network of HPC systems. The results show that Metamorphic Testing is appropriate for checking the correctness of communication networks supported by complex topologies in HPC systems.Postprin
Mesoscopic Non-Equilibrium Thermodynamics: Application to Radiative Heat Exchange in Nanostructures
Postural stress and risk conditions in manual load handling of Chilean industrial workers
Introduction: Although, there is a current regulatory framework for optimal manual handling of loads to preserve health conditions in the industrial sector, technical assessment and the use of certain instruments are still required for the diagnosis of occupational hazards. This study aimed to identify the occupational hazards associated with manual load handling in industry workers and estimate those resulting from postural stress.
Methods:  Fifty-two (52) industry workers took part in this cross-sectional study. All participants were evaluated using the Manual Handling Guide and the Reba assessment tool. Subjects were characterized, and risks associated with different tasks were detected.
Results: 59.6% of workers were between 18 and 45 years old. Lifting, lowering, and transporting loads activities had a repetitive task risk of 94%, exceeding the weight limit in 85.7% of cases. Pushing and pulling activities, mostly showed a working postural risk of 82% and a high perception of initial effort (Borg> 8). Reba score warned to intervene immediately in both types of tasks.
Conclusion: Risk from the manual handling of loads found in this study constitutes an alert that suggests reviewing compliance with the current regulation, as well as effective use of working pauses and the improvement of strategies to minimize physical efforts used by workers
Sequential Strong Measurements and Heat Vision
We study scenarios where a finite set of non-demolition von-Neumann
measurements are available. We note that, in some situations, repeated
application of such measurements allows estimating an infinite number of
parameters of the initial quantum state, and illustrate the point with a
physical example. We then move on to study how the system under observation is
perturbed after several rounds of projective measurements. While in the finite
dimensional case the effect of this perturbation always saturates, there are
some instances of infinite dimensional systems where such a perturbation is
accumulative, and the act of retrieving information about the system increases
its energy indefinitely (i.e., we have `Heat Vision'). We analyze this effect
and discuss a specific physical system with two dichotomic von-Neumann
measurements where Heat Vision is expected to show.Comment: See the Appendix for weird examples of heat visio
Global, Diffuse, Direct, and Ultraviolet Solar Irradiance Recorded in Malta and Atmospheric Component Influences
AbstractGlobal and diffuse shortwave (SW) and global erythemal (UVER) irradiances were measured in Malta, in the middle of Mediterranean Sea. The effect of solar zenith angle on these irradiances is studied using the measurements and simulations developed with a radiative transfer model. The role of ozone, scattering by gases, and aerosols is analyzed. Results show that ozone and Rayleigh scattering are the main drivers responsible for the behavior of UVER variations with SZA. In the case of global and diffuse irradiance, the role of aerosols is the principal determinant
Structural Brain Alterations in Female Survivors of Intimate Partner Violence
Intimate partner violence (IPV) has been related to brain alterations in female survivors. Nonetheless, few studies have used an exploratory approach, focusing on brain regions that are traditionally studied in other populations with post-traumatic stress. Traumatic brain injury (TBI), strangulation, and childhood trauma are highly prevalent among this population, and have also been associated with brain alterations and functional deterioration. As such, it is difficult to determine how different brain regions are affected by the complex interplay of these factors in female survivors. The aim of this study is to assess (a) brain alterations in female survivors of IPV as compared to non-victim females and (b) the potential causal mechanisms associated with such alterations. We hypothesized that structural brain differences would be found between female survivors of IPV and non-victims, and that these differences would be related to IPV-related TBI, strangulation, IPV severity, depression, post-traumatic stress, generalized anxiety, and childhood adverse experiences. A total of 27 non-victims and 28 survivors completed structural magnetic resonance imaging and questionnaires to measure the potential causal mechanisms for brain alterations. Structural brain differences were found between groups, principally in volumetric analyses. The brain regions in which between-group differences were found were related to attempted strangulation, IPV-related TBI, severity of IPV, adverse childhood experiences, and post-traumatic stress. These results demonstrate that a wider range of brain regions may be impacted by IPV and that various factors are implicated in the structural brain alterations found in female survivors. This study demonstrates the importance of post-traumatic stress, childhood and adult trauma, and physical violence in assessing brain alterations in IPV survivors. Further, it serves as a critical first step in assessing an extensive list of potential causal mechanisms for structural brain alterations, using a more comprehensive a whole-brain structural analysis of IPV female victims, a largely understudied and vulnerable population.I+D+I Operative Program FEDER project of the Andalusian Government in 2018
B-CTS-493-UGR18Ministry of Education and Professional Training in SpainUniversity of Granada (Spain)Spanish Ministry of Science, Innovation and Universities
FJCI-2017-3339
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