Enhanced mechanical properties of single-domain YBCO bulk superconductors processed with artificial holes

Single domain YBCO bulk superconductors were prepared using a conventional top-seeded melt growth (TSMG) technique. Artificial holes were introduced to the green sample prior to thermal processing using a bespoke “spiked” mould. Me- chanical properties such as elastic modulus, Vickers hardness, compressive strength and tensile strength were measured and compared to the properties of a standard bulk. The presence of the holes the bulk microstructure was observed to limit porosity and lower the concentration of macro-cracks in the bulk microstruc- ture, resulting in significantly enhanced mechanical properties of the bulk single grains. The elastic modulus of the perforated bulks was observed to exhibit an increase of more than 45% compared to the standard samples. Compressive and tensile strengths were also improved significantly in the samples containing artificial holes. Observed differences in Vickers hardness, on the other hand, were negligible. This could be due by the fact that the hard- ness is measured on a small surface area of the single grain sample, where the effect of lower porosity and lower concentration of macro-cracks is less relevant. The introduction of artificial holes to the bulk, single grain microstructure appears to be a very prom- ising technology for the production of melt-textured bulk super- conductors with enhanced mechanical properties.This work was financially supported by the Ministry of Industry and Trade of the Czech Republic (project TRIO FV10522)

Magnetic and morphological characterization of Nd2Fe14B magnets with different quality grades at low temperature 5-300 K

An increasing number of cryogenic devices may benefit from the use of Nd2Fe14B permanent magnets. However, it is necessary to precisely know their behavior because magnetization varies significantly due to Spin Reorientation Transition. In this work, magnetic and morphological characterization of Nd2Fe14B commercial polycrystalline magnets with different quality grades from 5 to 300 K is provided. A set of magnets ranging from N35 to N52 quality have been analyzed. Mean grain dimension as well as material composition elements are provided. Higher quality magnets show smaller mean grain dimensions. Regarding cryogenic temperatures, the well know spin transition effect appears in all the magnets as expected, however, the transition temperature occurs at different temperatures in a range from 112 to 120 K which is lower than those obtained for single crystal samples. Moreover, the relative variation of the remanence from 300 to 5 K is lower than 4% while the maximum expected variation is in average 11%. As extra information, the same analyzes are provided for additional quality grades N40M, N40S, N40SH and N40UH.The research leading to these results has received funding from the European Community's Seventh Framework Programme ([FP7/2007-2013]) under grant agreement n° 263014

High incidence of PTSD diagnosis and trauma-related symptoms in a trauma exposed bipolar I and II sample

Background: Post-traumatic stress disorder (PTSD) is an established comorbidity in Bipolar Disorder (BD), but little is known about the characteristics of psychological trauma beyond a PTSD diagnosis and differences in trauma symptoms between BD-I and BD-II. Objective: (1) To present characteristics of a trauma-exposed BD sample; (2) to investigate prevalence and trauma symptom profile across BD-I and BD-II; (3) to assess the impact of a lifetime PTSD diagnosis vs. a history of trauma on BD course; and (4) to research the impacts of sexual and physical abuse. Methods: This multi-center study comprised 79 adult participants with BD with a history of psychological trauma and reports baseline data from a trial registered in Clinical Trials (https://clinicaltrials.gov; ref: NCT02634372). Clinical variables were gathered through clinical interview, validated scales and a review of case notes. Results: The majority (80.8%) of our sample had experienced a relevant stressful life event prior to onset of BD, over half of our sample 51.9% had a lifetime diagnosis of PTSD according to the Clinician Administered PTSD scale. The mean Impact of Event Scale-Revised scores indicated high levels of trauma-related distress across the sample, including clinical symptoms in the PTSD group and subsyndromal symptoms in the non-PTSD group. Levels of dissociation were not higher than normative values for BD. A PTSD diagnosis (vs. a history of trauma) was associated with psychotic symptoms [2(1) = 5.404, p = 0.02] but not with other indicators of BD clinical severity. There was no significant difference between BD-I and BD-II in terms of lifetime PTSD diagnosis or trauma symptom profile. Sexual abuse significantly predicted rapid cycling [2(1) = 4.15, p = 0.042], while physical abuse was not significantly associated with any clinical indicator of severity. Conclusion: Trauma load in BD is marked with a lack of difference in trauma profile between BD-I and BD-II. Although PTSD and sexual abuse may have a negative impact on BD course, in many indicators of BD severity there is no significant difference between PTSD and subsyndromal trauma symptoms. Our results support further research to clarify the role of subsyndromic PTSD symptoms, and highlight the importance of screening for trauma in BD patients

Investigation about the influence of the mechanical properties of lead core and brass jacket of a NATO 7.62 mm ball bullet in numerical simulations of ballistic impacts

In the present work a validated numerical approach has been used in order to build a robust and reliable FE model of the impact of a NATO 7.62 mm ball bullet, against an aluminium transmission shaft. The bullet is a full metal jacket type, with a lead alloy core and a brass jacket. Target shaft is made by an Al6061-T6 aluminium alloy. According to the soft core (lead alloy) of the bullet, most effort has been spent in order to evaluate the effect of bullet materials mechanical properties on the numerical results. Numerical analyses, carried out using the non-linear dynamic finite element solver Abaqus∖Explicit 6.10, have been performed focusing on core and jacket material behaviour (target material, Al6061-T6, has been previously calibrated by the authors). Thus numerical analyses have been performed considering for the mechanical behaviour of the bullet both a simplified approach (as reported in literature) and new material data (with strain rate effect) obtained by means of experimental tests on the two materials (lead and brass) with specimens cut directly from the bullet. Finally the results of the analyses have been compared with real experimental ballistic tests

Very low frequency Syndromes

Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCThe aim of this chapter is to summarize updated knowledge about the clinical characteristics, etiology, genetic and molecular aspects, as well as mechanisms involved in syndromes having very low frequency, in order to promote their better recognition. During the last five years, a total of 30 syndromes have been published in this chapter of the Boletín del ECEMC. This issue includes the following selected syndromes: Crouzon, Pfeiffer, Apert, Saethre-Chotzen, Carpenter and Muenke. All share craniosynostosis as the main clinical feature but also present with other birth defects, the most important being limb malformations, specially syndactyly and polydactyly. Over 100 syndromes with craniosynostosis have been described, usually involving multiple sutures, and several of them are associated with limb malformations. The clinical overlapping between those syndromes makes difficult to perform a neonatal diagnosis, based on their clinical findings. However, molecular genetic testing, specifically of the FRGR1-3 and TWIST1 genes, could help to establish the diagnosis of some of them. Early diagnosis is important for establishing the most suitable treatment for each patient, as well as to offer an accurate genetic counselling and the possibility of preimplantational and/or prenatal diagnosis.N

Emporda music festivals as tourism diversification tools

International audienceThe purpose of this paper is to focus on territorial dynamics generated by five music festivals in the Emporda region (Spain) and its tourism sector. Using qualitative methodology, 10 qualified informants were interviewed. Their answers were coded and analysed. Territorial features favour the organisation of festivals. Promoters wish to offer some added value using local products. Festivals broadcast local identity to the world. Festivals’ features as tourist products explain how they are perceived as innovative.These existing products are being further developed to meet cultural tourism requirements. This strategy is justified by the search for innovation in a fiercely global competitive context.Current paper focuses on a present product and analyses its transformation: how a territory uses an old strategy in a new way generating future opportunities for tourism sector and local economies

Experimental characterization of a geothermal cooling system for enhancement of the efficiency of solar photovoltaic panels

The efficiency of solar photovoltaic panels reduces when their temperature increases during normal operation conditions, resulting in a very significant power output reduction. This phenomenon is especially relevant in regions with high photovoltaic potential where irradiance and ambient temperature are particularly high as well. To overcome this issue, a compact cooling system for commercial photovoltaic panels based on low-enthalpy geothermal cooling is proposed. Overheating is evacuated from the solar panel by a single-phase close-loop cooling system that gets benefit of a natural underground heat sink, which is at a constant and low temperature. A prototype, integrating a single axis sun tracking mechanism, has been assembled and tested in outdoor conditions in June 2022 in Alcalá de Henares, Madrid, Spain. As it has been experimentally demonstrated, with a coolant flowrate of 1.8 l/min per square meter of panel surface, the cooling system reduces the temperature of the cooled panel up to 20 °C, which resulted in a real improvement of the panel’s efficiency up to 13.8%. Finally, a sensitivity analysis of the net power gain and the net extra energy produced by the cooled panel is presented

Enhanced mechanical properties of single-domain YBCO bulk superconductors processed with artificial holes

Single domain YBCO bulk superconductors were prepared using a conventional top-seeded melt growth (TSMG) technique. Artificial holes were introduced to the green sample prior to thermal processing using a bespoke “spiked” mould. Me- chanical properties such as elastic modulus, Vickers hardness, compressive strength and tensile strength were measured and compared to the properties of a standard bulk. The presence of the holes the bulk microstructure was observed to limit porosity and lower the concentration of macro-cracks in the bulk microstruc- ture, resulting in significantly enhanced mechanical properties of the bulk single grains. The elastic modulus of the perforated bulks was observed to exhibit an increase of more than 45% compared to the standard samples. Compressive and tensile strengths were also improved significantly in the samples containing artificial holes. Observed differences in Vickers hardness, on the other hand, were negligible. This could be due by the fact that the hard- ness is measured on a small surface area of the single grain sample, where the effect of lower porosity and lower concentration of macro-cracks is less relevant. The introduction of artificial holes to the bulk, single grain microstructure appears to be a very prom- ising technology for the production of melt-textured bulk super- conductors with enhanced mechanical properties

Magnetic and morphological characterization of Nd2Fe14B magnets with different quality grades at low temperature 5\ue2\u80\u93300\ue2\u80\uafK

An increasing number of cryogenic devices may benefit from the use of Nd2Fe14B permanent magnets. However, it is necessary to precisely know their behavior because magnetization varies significantly due to Spin Reorientation Transition. In this work, magnetic and morphological characterization of Nd2Fe14B commercial polycrystalline magnets with different quality grades from 5 to 300 K is provided. A set of magnets ranging from N35 to N52 quality have been analyzed. Mean grain dimension as well as material composition elements are provided. Higher quality magnets show smaller mean grain dimensions. Regarding cryogenic temperatures, the well know spin transition effect appears in all the magnets as expected, however, the transition temperature occurs at different temperatures in a range from 112 to 120 K which is lower than those obtained for single crystal samples. Moreover, the relative variation of the remanence from 300 to 5 K is lower than 4% while the maximum expected variation is in average 11%. As extra information, the same analyzes are provided for additional quality grades N40M, N40S, N40SH and N40UH