Optimization of pulsed thermoelectric materials using simulated annealing and non-linear finite elements

[EN] The objective of this work is to determine the optimal shape, gains and duration of an electric pulse applied to a Peltier cell, together with the length of the thermoelectric to maximize cooling while min- imizing electric consumption. For this purpose, a fully coupled, multiphysics, dynamic finite-element model, which solves for the thermal, electric and mechanical fields is used. Because of the demanding computing requirements of the optimization process, a special mesh is designed and a convergence anal- ysis is carried out before using the multiphysics model. The highly non-linear optimization is done by simulated annealing, a heuristic algorithm in the Markov chain Monte-Carlo family. A preliminary para- metric investigation is presented, analyzing the impact of some of the parameters. The results of this pre- liminary analysis help to understand the effect of the different shapes in the evolution of the cold face temperature. Some of these results are expected and have already been discussed elsewhere, but others can only be explained after further analysis and a full system modeling. Pulse optimization is multiobjec- tive and multiparametric, i.e., it can consider several targets such as maximizing the cooling temperature, the cooling duration or others. The trade-offs between the different targets are studied. In all cases, stres- ses inside the thermoelement are examined at all points, and the pulses must meet the restriction that an equivalent stress is not above the allowable value.This research was partially supported by the grants, Haut-de-France Region (CR Picardie, 120-2015-RDISTRUCT-000010), EU funding (FEDER, RDISTRUCT-000010) for Chaire-de-Mecanique, and Spanish Ministry of Economy and Competitiveness grant CGL2014-59841-P. These supports are gratefully acknowledgedMoreno-Navarro, P.; Pérez-Aparicio, JL.; Gómez-Hernández, JJ. (2017). Optimization of pulsed thermoelectric materials using simulated annealing and non-linear finite elements. Applied Thermal Engineering. 120:603-613. https://doi.org/10.1016/j.applthermaleng.2017.04.036S60361312

Analytical and multicoupled methods for optimal steady-state thermoelectric solutions

[EN] Peltier cells have low efficiency, but they are becoming attractive alternatives for affordable and environmentally clean cooling. In this line, the current article develops closed-form and semianalytical solutions to improve the temperature distribution of Bi2Te3 thermoelements. From the distribution, the main objective of the current work-the optimal electric intensity to maximize cooling-is inferred. The general one-dimensional differential coupled equation is integrated for linear and quadratic geometry of thermoelements, under temperature constant properties. For a general shape, a piece-wise solution based on heat flux continuity among virtual layers gives accurate analytical solutions. For variable properties, another piece-wise solution is developed but solved iteratively. Taking advantage of the formulae, the optimal intensity is directly derived with a minimal computational cost; its value will be of utility for more advanced designs. Finally, a parametric study including straight, two linear, barrel, hourglass and vase geometries is presented, drawing conclusions on how the shape of the thermoelement affects the coupled phenomena. A specially developed coupled and non-linear finite element research code is run taking into account all the materials of the cell and using symmetries and repetitions. These accurate results are used to validate the analytical ones.This work was supported by the Generalitat Valenciana research programmes PROMETEO/2020/016: Applications de Topologic Isolators in Spintronics and Thermoelectricity (TOP-TERM) and BEST/2021/079. The support is gratefully acknowledged.Moreno-Navarro, P.; Pérez-Aparicio, JL.; Gómez-Hernández, JJ. (2022). Analytical and multicoupled methods for optimal steady-state thermoelectric solutions. Coupled Systems Mechanics, an international journal. 11(2):151-166. https://doi.org/10.12989/csm.2022.11.2.15115116611

An improved model for fast and reliable harbour wave agitation assessment

ABSTRACT: This study presents the new advances achieved in the field of harbour agitation climate assessment. Based on the improvement of an elliptic mild-slope model (MSP), which realistically reconstructs waves inside any-sized basin, represented by high-detailed unstructured meshes, and forced by real-shaped outer spectral data. A new solver is proposed for high performance runs, which allow fast agitation hindcast for statistical downtime analysis within an iterative and multi-scenario approach. Also, a realistic assimilation of partial reflection processes in quays/docks/wharfs/breakwaters is proposed. The model has been successfully validated in several harbours of special relevance in Spain with in situ measurements, through the assimilation of the hybrid downscaling (Camus et al., 2011) technique combined with monochromatic-based wave spectral reconstruction.This work has been also partially funded under the RETOS program of the Spanish Ministry of Science, Innovation and Universities (BIA2017-87213-R). We would like to thank Puertos del Estado of Spain for providing spectral outer wave spectral forcing and wave agitation measurements, for gather/organize each Port Authority base data required

Study of the oxygen reduction reaction on pure and Zr-doped YMnO3+δ SOFC electrode

The effect of Zr-doping on the novel SOFC cathode YMnO3 and its O2-Reduction Reaction (ORR) was studied using electrochemical impedance spectroscopy (EIS) as a function of temperature (500 < T < 800 °C) and the oxygen partial pressure (10−4 < pO2 < 1 atm). EIS technique allows identifying three processes controlling the ORR for each electrode, differentiated by their characteristic frequency, activation energies and pO2 dependence. High frequency contribution, only observed at 600°C for both electrodes, was attributed to oxygen ion transfer trough the electrode/electrolyte interface. In both electrodes, the Intermediate frequency contribution was described by a Gerischer impedance, related to a co-limiting process between oxygen ion diffusion and a surface process. However, whereas the EIS characteristics for YMnO3 can be explained by a surface process controlled by the electron transfer from oxide to O-adsorbed, it seems related for Y0.9Zr0.1MnO3 to the probability of finding a second free-surface site near to a diatomic intermediated for the O2 dissociation. These differences are in agreement with the improvement of the electrical properties when YMnO3 is doped with Zr. The low frequency contribution became important as pO2 decreased and temperature increased, and its characteristics would indicate a secondary surface process, co-limited with O2 gas diffusion for Y0.9Zr0.1MnO3 porous electrode.Fil: Moreno Botello, Zulma L.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Universidad Industrial Santander; ColombiaFil: Montenegro Hernández, Alejandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche.; ArgentinaFil: Mogni, Liliana Verónica. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche.; ArgentinaFil: Gauthier, Gilles H.. Universidad Industrial Santander; Colombi

Masculinity and feminity measurement in physical education teachers

Esta investigación tuvo por objetivo analizar las mediciones de masculinidad, feminidad, machismo y sumisión, características asociadas a la personalidad, de un grupo de docentes de Educación Física. Participaron en el estudio 53 docentes de nivel básico que laboran en un programa implementado por una institución gubernamental en la Ciudad de México. El muestreo fue de tipo no probabilístico. Se empleó como instrumento el Inventario de Masculinidad y Feminidad (IMAFE), instrumento confiable y válido en México, sujeto a prueba en otros países, en él se incluyen aspectos de los papeles de género tradicionales: machismo y sumisión. El análisis de los datos se efectúo mediante la prueba “t-Student” y el análisis de varianza de una clasificación, así como la comparación de medias de los resultados arrojados. Se concluye que no hay diferencias estadísticamente significativas en las cuatro escalas propuestas por el IMAFE y las variables de trabajo, sexo, edad y estado civil, en el grupo de docentes de Educación Física, en lo que respecta a las características asociadas a la personalidadThis research aimed to analyze the measurements of masculinity, femininity, machismo and submission features associated with the personality characteristics of a group of physical education teachers. Participated in the study53 basic level teachers working in a program implemented by a government institution in Mexico City. The sampling was not probabilistic type. As a tool for data collection was used the Inventory of Masculinity and femininity (IMAFE), reliable and valid instrument in Mexico, subject to testing in other countries, there aspects of traditional gender roles: machismo and submission. Data analysis undertaken using the “t-student” test and analysis of variance classification and comparison of the results obtained. It is concluded that no statistically significant differences in the four scales proposed by IMAFE and work variables sex, age and marital status in the group of physical education teachers in regard to the characteristics associated with personalit

Examining the Role of Facial Affect Recognition In The Relation Between Physiological Reactivity And Aggression During Marital Conflict

Understanding the affective mechanisms that underlie aggression and violence within interpersonal relationships is vital to the development of treatments that will reduce recidivism. Researchers examining physiological factors of emotion have identified differential patterns of physiological reactivity among different types of intimate partner violence (IPV) perpetrators during interpersonal conflict. Although it is unclear what mechanisms are influencing these distinct physiological patterns, research suggests that perpetrators’ ability to decode emotions may be involved. The current study examined the effects of physiological reactivity on observed aggression of male IPV perpetrators during marital conflict across levels of facial affect recognition (FAR) accuracy. In particular, we examined the sympathetic nervous system, via Skin Conductance Level (SCL) Reactivity, and the parasympathetic nervous system, via Respiratory Sinus Arrhythmia (RSA) reactivity. Secondary data analyses were conducted on a previous study examining heterosexual couples with past male to female IPV perpetration. Couples completed self-report measures and participated in a conflict discussion regarding a topic of conflict with their partner while physiological and behavioral measures were recorded. Additionally, males were administered a facial affect recognition task. Results suggest that RSA and SCL reactivity had a significant effect on male observed aggression at high FAR accuracy. Specifically, co-deactivation of both parasympathetic and sympathetic nervous system activity was associated with increased observed aggressive behavior. Our result suggests a dual physiological model of affect reactive aggression: parasympathetic withdrawal indicative of emotional dysregulation, and sympathetic attenuation associated with behavioral disinhibition.Psychology, Department o

Contests in two fronts

Within the framework of Game Theory, contests study decision-making in those situations or conflicts when rewards depend on the relative rank between contenders rather than their absolute performance. By relying on the formalism of Tullock success functions, we propose a model where two contenders fight in a conflict on two fronts with different technology levels associated: a front with large resource demand and another with lower resource requirements. The parameter of the success function in each front determines the resource demand level. Furthermore, the redistribution or not of resources after a tie defines two different games. We solve the model analytically through the best-response map dynamics, finding a critical threshold for the ratio of the resources between contenders that determines the Nash Equilibrium basin and, consequently, the peace and fighting regimes. We also perform numerical simulations that corroborate and extend these findings. We hope this study will be of interest to areas as diverse as economic conflicts and geopolitics.Comment: 21 pages, 11 figure

Freeze desalination by the integration of falling film and block freeze concentration techniques

Block and falling film freeze concentration are two technologies that separate water by freezing,with the potential to desalinate seawater. In this study, the integration of two freeze concentration techniques as an alternative to obtain potable water was analysed. Water with 0.5%–8% NaCl was freeze-concentrated by the falling film technique. The ice from each stage was fractionally thawed to recover the solids retained inPostprint (updated version

Influence of a football match on landing biomechanics and jump performance in female football players

This study aimed to assess the acute effect of a competitive football match on jump performance and kinematic parameters during jump landing in semiprofessional female football players. Twenty-two semiprofessional players (20 ± 3 years) underwent a drop jump task for a posterior video analysis of the landing phase. These measurements were obtained at (1) baseline, (2) after, and (3) 48 h after a competitive football match. A one-way ANOVA with repeated measures was employed to detect differences over the time. There was a main effect of time for maximal knee flexion angle during drop landing (p = 0.001). In comparison with baseline, maximal knee flexion angle was reduced immediately post-match and was still reduced 48 h after the match (63.4 ± 8.6 vs 57.0 ± 11.7 vs 48.9 ± 19.1, p ≤ 0.038). There was also a main effect of time for drop jump height (p < 0.001). Drop jump height was reduced immediately post-match and remained low 48 h after the match in comparison with baseline (27.3 ± 3.6 vs 24.5 ± 2.8 ~ 25.5 ± 3.0 cm, p ≤ 0.002). There was a main effect of time on hip flexion angle during landing (p = 0.001), but the pairwise comparison revealed that this variable was not affected immediately post-match but was lower 48 h after the match than at baseline (50.1 ± 10.1 ~ 50.8 ± 13.2 vs 38.1 ± 17.8 °, p ≤ 0.005). A competitive football match worsened jump performance and several landing biomechanical parameters in female football players, which were still decreased in comparison with baseline even 48 h after the match

Impact of the new handling recommendations for hazardous drugs in a hospital pharmacy service

Objective: To describe the actions taken by the Pharmacy Unit in a tertiary hospital in order to adapt to the recommendations established by NIOSH 2014 for handling Hazardous Drugs. Method: A retrospective observational study. A list was prepared including all hazardous drugs according to NIOSH 2014 that were available at the hospital as marketed or foreign drugs, or used in clinical trials, and there was a review of the processes of acquisition, repackaging, preparation, circuits, organizational, dispensing and identification. Results: After the analysis, a report including all needs was prepared and sent to the Hospital Management. Any relevant information about the handling and administration of hazardous drugs was included in the prescription computer program. There were changes in the acquisition process of two drugs, in order to avoid splitting and multi-dose formulations. An alternative or improvement was found for 35 253 of the 75 779 units of hazardous drugs repackaged in one year. The Pharmacy Unit took over the preparation of four non-sterile medications, as well as the preparation of all sterile parenteral medications included in Lists 1 and 2 that were not previously prepared there, as well as one from List 3. Information was also included about the preparation processes of Magistral Formulations that involved hazardous drugs from Lists 2 or 3