The average longitudinal air shower profile: exploring the shape information

The shape of the extensive air shower (EAS) longitudinal profile contains information about the nature of the primary cosmic ray. However, with the current detection capabilities, the assessment of this quantity in an event-by-event basis is still very challenging. In this work we show that the average longitudinal profile can be used to characterise the average behaviour of high energy cosmic rays. Using the concept of universal shower profile it is possible to describe the shape of the average profile in terms of two variables, which can be already measured by the current experiments. These variables present sensitivity to both average primary mass composition and to hadronic interaction properties in shower development. We demonstrate that the shape of the average muon production depth profile can be explored in the same way as the electromagnetic profile having a higher power of discrimination for the state of the art hadronic interaction models. The combination of the shape variables of both profiles provides a new powerful test to the existing hadronic interaction models, and may also provide important hints about multi-particle production at the highest energies.Peer Reviewe

Remapping algorithms: application to trimming operations in sheet metal forming

Most of sheet metal forming processes comprise intermediate trimming operations to remove superfluous material. These operations are required for subsequent forming operations. On the other hand, the springback is strongly influenced by the trimming operations that change the part stiffness and the stress field. From the numerical point of view, this involves the geometrical trimming of the finite element mesh and subsequent remapping of the state variables. This study presents a remapping method based on Dual Kriging interpolation, specifically developed for hexahedral finite elements, which has been implemented in DD3TRIM in-house code. Its performance is compared with the one of the Incremental Volumetric Remapping method, using the split-ring test to highlight their advantages and limitations. The numerical simulation of the forming processes is performed with DD3IMP finite element solver.The authors gratefully acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) under the projects with reference UID/EMS/00285/2013, PTDC/EMS-TEC/0702/2014 (POCI-01-0145-FEDER-016779) and PTDC/EMS-TEC/6400/2014 (POCI-01-0145-FEDER-016876) by UE/FEDER through the program COMPETE2020. The first author is also grateful to the FCT for the Postdoctoral grant SFRH/BPD/101334/2014.info:eu-repo/semantics/publishedVersio

Examining the Coach Motivation Questionnaire in Fitness Professionals (CMQ-FP): Factor Structure, Invariance, and Predictive Analysis

Purpose: To date, most research on the assessment of motivation has been exerciser-focused and has not considered how fitness professionals’ motivations impact their behaviors toward exercisers during training sessions. The purpose of this study was to examine the factor structure of the Coach Motivation Questionnaire in a sample of fitness professionals (CMQ-FP) to ascertain its usefulness for this vocational grouping. Measurement invariance analysis was conducted between female and male fitness professionals, and predictive validity was tested considering need-supportive and need-thwarting behaviors as outcomes. Methods: Participants were 799 fitness professionals (female = 412) aged between 20 and 56 years (M = 28.71, SD = 3.24), who completed a multi-section survey assessing their motivation toward work and their interpersonal behaviors when engaging with exercisers. Results: The results of this research supported all three hypotheses. First, the hypothesized 6-factor measurement model showed acceptable fit to the data. Second, the factor structure of the CMQ-FP was invariant across gender (male and female fitness professionals). Third, fitness professionals’ (autonomous or controlled) motivation was a valid predictor of need-supportive or need-thwarting behaviors. Conclusion: This study supported the factor structure of the CMQ-FP, presenting as a valid measure of motivation in fitness professionals. Understanding fitness professionals’ perceptions of their coaching motivation can inform professional development activities to assist fitness professionals to increase understanding of what motivates these professionals and how they might be more need-supportive and less need-thwarting in their pedagogical behaviors.info:eu-repo/semantics/publishedVersio

XENO-Free production and recovery of human pluripotent stem cells using synthetic dissolvable microcarriers

The implementation of scalable culture platforms for the large-scale production of human pluripotent stem cells (hPSC) and their derivatives is mandatory to fulfill the requirement of obtaining large numbers of these cells for cell therapies and other in vitro biomedical applications, such as drug screening, toxicology assays and disease modeling. Recent progress includes the development of chemically-defined culture conditions for manufacturing of hPSC and their derivatives, namely the development of xeno-free microcarrier platforms to meet good manufacturing practice (GMP) quality requirements [1]. One challenge that remains to be addressed is the establishment of a robust, scalable, and cost-effective downstream processing for cell recovery and removal of the microcarriers. Since hPSC have the tendency to create multilayers of cells on the microcarriers, often forming very large cell-microcarrier aggregates, the process of cell recovery can be technically challenging and time consuming. In this work, we developed a robust and efficient platform for large-scale production of hPSC using synthetic dissolvable microcarriers, which can be quickly dissolved by a non-proteolytic enzyme. This allows an easy cell recovery without the need of the microcarrier separation step, facilitating the downstream processing. Moreover, these synthetic microcarriers are sterile and ready-to-use, and are functionalized with the Synthemax® surface, based on a peptide-acrylate matrix designed for long-term support of hESC self-renewal [2]. hPSC were able to attach and grow on the dissolvable microcarriers and the expansion process was evaluated in a scalable stirred culture system. The cells growth performance on these microcarriers was comparable with the ones obtained when culturing hPSCs in non-dissolvable microcarriers (backbone of polystyrene coated with different ECM molecules), being possible to obtain 1.3x106 cells/mL during 5 days. Importantly, hPSCs cultured on these novel microcarriers were efficiently recovered without the need of the filtration step to separate the microcarriers from the cells and maintained their typical colony morphology and pluripotency-associated marker-expression after re-plating on tissue culture plates. Moreover, their potential for spontaneous differentiation into cells of the three embryonic germ layers was demonstrated through formation of embryoid bodies containing cells expressing typical markers of endoderm, ectoderm and mesoderm. These novel synthetic dissolvable microcarriers allow an easy and efficient downstream processing for hPSCs recovery after expansion/differentiation, without compromising the quality of the cells (viability, potency and functionality), which are a major process breakthrough for stem cell manufacturing. [1] Badenes SM, et al., “Defined Essential 8™ Medium and Vitronectin Efficiently Support Scalable Xeno-Free Expansion of Human Induced Pluripotent Stem Cells in Stirred Microcarrier Culture Systems”, PlosOne (2016), 11(3):e0151264. [2] Melkoumian Z, et al, “Synthetic peptide-acrylate surfaces for long-term self-renewal and cardiomyocyte differentiation of human embryonic stem cells”, Nat Biotechnol (2010), 28(6): 606-10. Acknowledgements: We acknowledge CORNING Incorporated for supplying the dissolvable microcarriers

Purification of plasmid DNA vectors by aqueous two-phase extraction and hydrophobic interaction chromatography

The current study explores the possibility of using a polyethyleneglycol(PEG)/ammonium sulphate aqueous two-phase system (ATPS) as an early step in a process for the purification of a model 6.1 kbp plasmid DNA (pDNA) vector. Neutralised alkaline lysates were fed directly to ATPS. Conditions were selected to direct pDNA towards the salt-rich bottom phase, so that this stream could be subsequently processed by hydrophobic interaction chromatography (HIC). Screening of the best conditions for ATPS extraction was performed using three PEG molecular weights (300, 400, 600) and varying the tie-line length, phase volume ratio and lysate load. For a 20 % (w/w) lysate load, the best results were obtained with PEG 600 using the shortest tie-line (38.16 % w/w). By further manipulating the system composition along this tie-line in order to obtain a top/bottom phase volume ratio of 9.3 (35 % w/w PEG 600, 6% w/w NH4)2SO4), it was possible to recover 100 % of pDNA in the bottom phase with a 3-fold increase in concentration. Further increase in the lysate load up to 40 %(w/w) with this system resulted in a 8-fold increase in pDNA concentration, but with a yield loss of 15 %. The ATPS extraction was integrated with HIC and the overall process compared with a previously defined process that uses sequential precipitations with isopropanol and ammonium sulphate prior to HIC. Although the final yield is lower in the ATPS-based process the purity grade of the final pDNA product is higher. This shows that it is possible to substitute the time-consuming two-step precipitation procedure by a simple ATPS extraction.Portuguese Ministry of Science and Technology - POCTI/BIO/47245/2002

Influence of heat pipe operating temperature on exhaust heat thermoelectric generation

Increasingly stringent targets on energy efficiency and emissions, as well as growing vehicle electrification are making attractive the electric recovery of the energy normally wasted through the tailpipe of Internal Combustion Engines. Recent developments in thermoelectrics (TE) may soon make them a viable solution for such applications. This team has been exploring the potential of using TE modules in combination with variable conductance heat pipes for transferring the exhaust heat to the generator with very low thermal resistance and at a constant, prescribed temperature. This passive temperature control eliminates the need for by-pass systems in the event of temperature overshoots. The operating temperature of a generator should be as high as possible in order to maximize the Seebeck effect. However, currently available modules are temperature limited. Moreover, the higher the HP temperature the less the usable thermal power at the exhaust will be (heat can only be transferred to from a hotter to a colder body). The present work assesses both theoretically and experimentally the influence of the HP temperature in the electric output of a thermoelectric generator. A small diesel engine and a generator were tested and it was found that a high HP operating temperature is only limitative for performance in the cases where low exhaust temperature and low engine power are present. In those cases it is possible to estimate an optimal HP temperature in order to maximize power output. The combined use of Seebeck modules and heat pipes was found to be highly advantageous in various ways.Fundação para a Ciência e a Tecnologia (FCT), FEDER e POFC CompeteMIT Portugal EDAM, Project MOBI-MP

Considering the stiffness of the forming tools in the numerical analysis of the ironing process

Ironing can occur in cylindrical cup drawing whenever the thickness of the drawn flange is larger than the gap between the punch and the die. This is particularly relevant for materials that present r-values lower than 1.0, such as the aluminium alloys, since they tend to present more thickening of the flange. The aim of this study is to evaluate numerically the impact of the elastic deformation of the forming tools on the final cup geometry, i.e., the earing profile and the evolution of thickness along the circumferential direction, at different heights. Different contact conditions are also analysed since they strongly affect both the thickness strain and the earing profile. The process conditions considered are the ones from EXACT, the ESAFORM Benchmark 2021, enabling the comparison with experimental results. Considering the deformation of the forming tools mainly impacts the ironing stage, enabling predicting wall thickness values larger than the gap between the punch and the die.The authors gratefully acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) under projects with reference 2022.08459.PTDC, UIDB/00285/2020 and LA/P/0112/2020

Fish communities in the lower Tagus inland wetlands: from anthropogenic pressures to conservation management

Inland wetlands are important biodiversity hotspots and amongst the most impacted ecosystems worldwide. Conservation management and restauration actions in wetlands are thus urgently needed to reverse trends in species loss and habitat degradation, particularly in regions harbouring already endangered endemic species. Inland wetlands may play an important role in supporting endemic endangered fishes in the Lower Tagus basin, where anthropogenic pressures have been increasing, but there is a lack of studies on fish communities, and few areas are identified as inland wetlands. Here, we aim to identify small inland wetlands in the Lower Tagus River and their potential role in supporting fish species, constituting the first study to identify and evaluate the most important fish communities. Inland wetlands were identified through the usage of remote sensing techniques and the calculation of a Normalized Difference Water Index (NDWI) with Sentinel-2 imagery for the Lower Tagus region. From a total of 486 locations identified, 31 were recognized as wetlands as having potential to host fish communities, with 11 being selected for sampling after in loco assessment. Fish sampling was conducted between 6 May and 11 June 2021. Furthermore, for each wetland, we evaluated anthropogenic stressors and land use changes between 2007 and 2018, using national land use data (i.e., Carta de Uso e Ocupação do Solo). A total of 7727 fishes from eight non-native and five native species were captured. Overall, fish communities were dominated by non-native species (97% catches), but both European eel (Anguilla anguilla) and Lisbon arched-mouth nase (Iberochondrostoma olisiponense), which are globally classified as critically endangered (CR), were found in at least two wetlands. Our results suggest that, over the last 10 years, intensive agriculture decreased (on average ≈ 3%) in the areas surrounding these wetlands, being replaced by extensive agriculture or natural uses. Despite non-native fish prevalence, some wetlands may act as refuge habitats for CR fish species. These results are important for guiding the restoration of inland wetlands and promoting conservation management actions to help reverse fish diversity loss.info:eu-repo/semantics/publishedVersio

Effect of carbon support on the activity of monodisperse Co45Pt55 nanoparticles for oxygen evolution in alkaline media

Oxygen evolution reaction (OER) represents the efficiency-limiting reaction in water electrolyzers, metal-air batteries, and unitized regenerative fuel cells. To achieve high-efficiency OER in alkaline media, we fabricated three novel electrocatalysts by the assembly of as-prepared Co45Pt55 alloy nanoparticles (NPs) on three different carbon-based support materials: reduced graphene oxide (CoPt/rGO), mesoporous graphitic carbon nitride (CoPt/mpg-CN), and commercial Ketjenblack carbon (CoPt/KB). Voltammetry studies revealed that CoPt/rGO electrocatalyst provided lower OER overpotentials accompanied by higher currents and specific current density values than the other two studied materials. Moreover, CoPt/rGO outperformed commercial CoPt/C electrocatalysts in terms of notably higher specific current densities. Additionally, it was found that CoPt/rGO electrocatalyst activity increases with increasing temperature up to 85°C, as suggested by the increase in the exchange current density. Electrochemical impedance spectroscopy studies of three electrocatalysts in OER revealed similar charge transfer resistance, although CoPt/rGO provided a higher current density. The main issue observed during long-term chronoamperometry and chronopotentiometry studies is the materials’ instability under OER polarization conditions, which is still to be tackled in future work