Topological structures of the resistive pressure gradient turbulence with averaged poloidal flow

When a significant averaged poloidal flow is generated by the resistive pressure-gradient-driven turbulence the topological properties of the flow structures can change in some radial regions where the shear flow is large. We have applied the topological analysis approach that we have developed (2013 J. Phys. A: Math. Theor. 46 375501) to this situation and found that in addition to the filamentary vortex structures there are deformed toroidal structures that seem to act as transport barriers. Analysis of all these structures is presented here.This research was sponsored by DGICYT (Dirección General de Investigación Científica y Técnica) of Spain under Project No. ENE2012-38620-C02-02. One of us (B.A.C) also gratefully acknowledges the support from a 'Cátedra de Excelencia' from Universidad Carlos III and Banco de Santander

Fast 3-D heat transfer model for computing internal temperatures in the bearing housing of automotive turbochargers

[EN] Each of the elements that make up the turbocharger has been gradually improved. In order to ensure that the system does not experience any mechanical failures or loss of efficiency, it is important to study which engine operating conditions could produce the highest failing rate. Common failing conditions in turbochargers are mostly achieve due to oil contamination and high temperatures in the bearing system. Thermal management becomes increasingly important for the required engine performance. Therefore, it has become necessary to have accurate temperature and heat transfer models. Most thermal design and analysis codes need data for validation; often the data available falls outside the range of conditions the engine experiences in reality leading to the need to interpolate and extrapolate disproportionately. This paper presents a fast 3D heat transfer model for computing internal temperatures in the central housing for non-water cooled turbochargers and its direct validation with experimental data at different engine operating conditions of speed and load. The presented model allows a detailed study of the temperature rise of the central housing, lubrication channels, and maximum level of temperature at different points of the bearing system of an automotive turbocharger. It will let to evaluate thermal damage done to the system itself and influences on the working fluid temperatures, which leads oil coke formation that can affect the performance of the engine. Thermal heat transfer properties obtained from this model can be used for to feed and improve a radial lumped model of heat transfer that predicts only local internal temperatures[1]. Model validation is illustrated and finally the main results are discussed.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Authors want to acknowledge the Apoyo para la investigación y Desarrollo (PAID) grant for doctoral studies (FPI-2016-S2-1354).Gil, A.; Tiseira, A.; García-Cuevas González, LM.; Rodriguez-Usaquen, YT.; Mijotte, G. (2018). Fast 3-D heat transfer model for computing internal temperatures in the bearing housing of automotive turbochargers. International Journal of Engine Research. https://doi.org/10.1177/1468087418804949SKhalife, E., Tabatabaei, M., Demirbas, A., & Aghbashlo, M. (2017). Impacts of additives on performance and emission characteristics of diesel engines during steady state operation. Progress in Energy and Combustion Science, 59, 32-78. doi:10.1016/j.pecs.2016.10.001Payri, F., Olmeda, P., Martín, J., & Carreño, R. (2015). Experimental analysis of the global energy balance in a DI diesel engine. Applied Thermal Engineering, 89, 545-557. doi:10.1016/j.applthermaleng.2015.06.005Serrano, J. R., Tormos, B., Gargar, K. L., & Bouffaud, F. (2011). Study of the Effects on Turbocharger Performance Generated by the Presence of Foreign Objects at the Compressor Intake. Experimental Techniques, 37(2), 30-40. doi:10.1111/j.1747-1567.2011.00795.xGalindo, J., Serrano, J. R., Dolz, V., López, M. A., & Bouffaud, F. (2013). Behavior of an IC Engine Turbocharger in Critical Conditions of Lubrication. SAE International Journal of Engines, 6(2), 797-805. doi:10.4271/2013-01-0921Deligant, M., Podevin, P., & Descombes, G. (2011). CFD model for turbocharger journal bearing performances. Applied Thermal Engineering, 31(5), 811-819. doi:10.1016/j.applthermaleng.2010.10.030Sim, K., Lee, Y.-B., & Kim, T. H. (2013). Effects of Mechanical Preload and Bearing Clearance on Rotordynamic Performance of Lobed Gas Foil Bearings for Oil-Free Turbochargers. Tribology Transactions, 56(2), 224-235. doi:10.1080/10402004.2012.737502Drewczynski, M., & Rzadkowski, R. (2015). A stress analysis of a compressor blade in partially blocked inlet condition. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 230(5), 934-952. doi:10.1177/0954410015601149Filsinger, D., Szwedowicz, J., & Scha¨fer, O. (2001). Approach to Unidirectional Coupled CFD–FEM Analysis of Axial Turbocharger Turbine Blades. Journal of Turbomachinery, 124(1), 125-131. doi:10.1115/1.1415035Romagnoli, A., & Martinez-Botas, R. (2012). Heat transfer analysis in a turbocharger turbine: An experimental and computational evaluation. Applied Thermal Engineering, 38, 58-77. doi:10.1016/j.applthermaleng.2011.12.022De Faoite, D., Browne, D. J., Chang-Díaz, F. R., & Stanton, K. T. (2011). A review of the processing, composition, and temperature-dependent mechanical and thermal properties of dielectric technical ceramics. Journal of Materials Science, 47(10), 4211-4235. doi:10.1007/s10853-011-6140-1Sachdev, A. K., Kulkarni, K., Fang, Z. Z., Yang, R., & Girshov, V. (2012). Titanium for Automotive Applications: Challenges and Opportunities in Materials and Processing. JOM, 64(5), 553-565. doi:10.1007/s11837-012-0310-8Tetsui, T. (2002). Development of a TiAl turbocharger for passenger vehicles. Materials Science and Engineering: A, 329-331, 582-588. doi:10.1016/s0921-5093(01)01584-2Wu, X. (2006). Review of alloy and process development of TiAl alloys. Intermetallics, 14(10-11), 1114-1122. doi:10.1016/j.intermet.2005.10.019Appel, F., Paul, J. D. H., & Oehring, M. (2011). Gamma Titanium Aluminide Alloys. doi:10.1002/978352763620

Observation of a Griffiths-like phase in the paramagnetic regime of ErCo_2

A systematic x-ray magnetic circular dichroism study of the paramagnetic phase of ErCo2 has recently allowed to identify the inversion of the net magnetization of the Co net moment with respect to the applied field well above the ferrimagnetic ordering temperature, Tc. The study of small angle neutron scattering measurements has also shown the presence of short range order correlations in the same temperature region. This phenomenon, which we have denoted parimagnetism, may be related with the onset of a Griffiths-like phase in paramagnetic ErCo2. We have measured ac susceptibility on ErCo2 as a function of temperature, applied field, and excitation frequency. Several characteristics shared by systems showing a Griffiths phase are present in ErCo2, namely the formation of ferromagnetic clusters in the disordered phase, the loss of analyticity of the magnetic susceptibility and its extreme sensitivity to an applied magnetic field. The paramagnetic susceptibility allows to establish that the magnetic clusters are only formed by Co moments as well as the intrinsic nature of those Co moments

Women with psychotic episodes during pregnancy show increased markers of placental damage with Tenney-Parker changes

y. Psychosis is a hazardous and functionally disruptive psychiatric condition which may affect women in pregnancy, entailing negative consequences for maternofetal well-being. The precise pathophysiological basis and consequences of a psychotic episode in pregnancy remain to be further elucidated. The placenta is a pivotal tissue with many functions in the gestational period, critically influencing the fate and development of pregnancy. Although detrimental alterations have been observed in women undergoing severe psychiatric disorders in pregnancy, there are little studies evaluating the consequences of suffering from a psychotic episode in the placental tissue In this work, we have evaluated the histopathological consequences of a first episode of psychosis in pregnancy (FE-PW; N=22) and compare them with healthy pregnant women (HC-PW; N=20) by using histological, immunohistochemical and gene expression techniques. Our results define that the placental tissue of FE-PW display an increase in the number of placental villi, bridges, syncytial knots and syncytial knots/villi. Besides, we have also observed an enhanced gene and protein expression in FE-PW of the hypoxic marker HIF-1α, together with the apoptotic markers BAX and Bcl-2. To our knowledge, this is the first study demonstrating significant histopathological changes in the placenta of women suffering a new-onset psychotic episode in pregnancy. Further studies should be aimed at deepening the knowledge about the pernicious effects of psychosis in the maternofetal tissues, as well as the potential implications of these alterations

Microvascular cutaneous coverage in wounds that expose the Achilles tendon: case report

Achilles tendon rupture, being one of the main tendon ruptures present, surgery being the most favourable option even taking into account complications such as infections and skin necrosis, it is necessary to develop techniques which help to reduce complications and increase benefits. The methods follow-up of 2 cases of patients with skin defects in the region of the Achilles tendon in patients who were treated at the "Luis Guillermo lbarra lbarra" national rehabilitation institute during the period 2020-2021 in the Traumatology service, treated with radial free flap forearm, using the description of the most used flaps in the literature. Results in both cases integrity of the free radial forearm flap in its entirety, functional recovery for walking, ability to put shoes back on, and without the need for reoperation, as well as a high level of satisfaction by patients. Conclusions if we are talking about an Achilles tendon rupture with a significant skin defect, the free radial forearm flap is an adequate option, if we are talking about a complete defect, the composite flap is the best option, remember that the decision on what type of flap will be used will depend on of the size of the lesion

Moderate-to-vigorous physical activity as a mediator between sedentary behavior and cardiometabolic risk in Spanish healthy adults: a mediation analysis

Background: Public health strategies for cardiovascular prevention highlight the importance of physical activity, but do not consider the additional potentially harmful effects of sedentary behavior. This study was conducted between 2010 and 2012 and analyzed between 2013 and 2014. The aim of the study was to analyze the relationship between sedentary behavior and cardiometabolic risk factors in the Spanish adult population and to examine whether this relationship is mediated by moderate-to-vigorous physical activity (MVPA). Methods: The cross-sectional study included 1122 healthy subjects belonging to the EVIDENT study. Sedentary behavior was objectively measured over 7 days using Actigraph accelerometers. We assessed waist circumference (WC), triglycerides-to-HDL-C ratio (TG/HDL-C), and mean arterial pressure (MAP), and undertook homeostasis model assessment (HOMA-IR). Linear regression models were fitted according to Baron and Kenny procedures for mediation analysis. Results: TG/HDL-C and HOMA-IR were significantly higher in adults who spent more minutes in sedentary activities after adjusting for potential covariates. However when MVPA was added to the ANCOVA models as covariate the effect of sedentary time on HOMA-IR disappeared. In addition, MVPA acted as a full mediator of the relationship between sedentary time and HOMA-IR. In contrast, subjects with lower levels of MVPA presented worse cardiometabolic profiles than those from higher MVPA categories, even after controlling for sedentary time and other potential confounders. Conclusions: These results suggest that both MVPA and sedentary time should be considered when developing cardiometabolic risk guidelines

Goats as Valuable Animal Model to Test the Targeted Glutamate Supplementation upon Antral Follicle Number, Ovulation Rate, and LH-Pulsatility

The potential effect of intravenous administration of glutamate on the ovarian activity and the LH secretion pattern, considering the anestrous yearling goat as an animal model, were assessed. In late April, yearling goats (n = 20) were randomly assigned to either (1) Glutamate supplemented (GLUT; n = 10, Live Weight (LW) = 29.6 ± 1.02 kg, Body Condition (BCS) = 3.4 ± 0.2 units; i.v. supplemented with 7 mg GLUT kg−1 LW) or (2) Non-supplemented (CONT; n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2 units; i.v. saline). The oats were estrus-synchronized; blood sampling (6 h × 15 min) was carried out for LH quantification. Response variables included pulsatility (PULSE), time to first pulse (TTFP), amplitude (AMPL), nadir (NAD), and area under the curve (AUC) of LH. Ovaries were ultra-sonographically scanned to assess ovulation rate (OR), number of antral follicles (AF), and total ovarian activity (TOA = OR + AF). LH-PULSE was quantified with the Munro algorithm; significant treatment x time interactions were evaluated across time. The variables LW and BCS did not differ (p > 0.05) between the experimental groups. Nevertheless, OR (1.77 vs. 0.87 ± 0.20 units), TOA (4.11 vs. 1.87 ± 0.47 units) and LH-PULSE (5.0 vs. 2.2 pulses 6 h-1) favored (p < 0.05) to the GLUT group. Our results reveal that targeted glutamate supplementation, the main central nervous system neurotransmitter, arose as an interesting strategy to enhance the hypothalamic–hypophyseal–ovarian response considering the anestrous-yearling goat as an animal model, with thought-provoking while promising translational applications

Recensiones [Revista de Historia Económica Año IV Invierno 1986 n. 1 pp. 209-252]

Frencesco de Martino. Historia Económica de la Roma Antigua (Por Luis A. García Moreno).-- Manuel Tuñón de Lara (dir.). Textos y documentos de Historia Antigua, Media y Moderna hasta el siglo XVI (Selección de Mangas, Sayas, García Moreno, Valdeón, Salrach, Mina, Arizcun, Arié y Pérez). (Por Javier Faci).-- Manuel Martín Rodríguez. Pensamiento económico español sobre la población. De Soto a Matanegui (Por Vicente Pérez Moreda).-- P. Bairoch y A. M. Piuz (eds.). Les passages des économies traditionnelles européennes aux sociales industrielles (Por Jaume Torras Elías).-- Annales, Économies, Sociétés, Civilisations, año 39, 1984, núm. 5 (Por Gregorio Núñez Romero-Balmas).-- Josep Oliveras i Samitier. Desenvolupament industrial i evolució urbana a Manresa (1800-1870) (Por Caries Sudrià).-- Juan Antonio Vázquez García. La cuestión hullera en Asturias (1918-1935) (Por Sebastián Coll Martín).-- Ignacio Villota Elejalde. Vizcaya en la política minera española. Las asociaciones patronales, 1886-1914 (Por Mercedes Cabrera).-- José García Lasaosa: Basilio Paraíso. Industrial y político aragonés de la Restauración (Por Guillermo Cortázar).-- Bill Albert y Adrian Graves (eds.). Crisis and Change in the International Sugar Economy 1860-1914 (Por Manuel Martín Rodríguez).-- G. R. Hawke. Economía para historiadores (Por Gabriel Tortella).-- Robert William Fogel y G. R. Elton. Which Road to the Past? Two Views of History (Por Donald R. Abbott)Publicad