Instabilities and propagation of neutrino magnetohydrodynamic waves in arbitrary direction

In a previous work [16], a new model was introduced, taking into account the role of the Fermi weak force due to neutrinos coupled to magnetohydrodynamic plasmas. The resulting neutrino-magnetohydrodynamics was investigated in a particular geometry associated with the magnetosonic wave, where the ambient magnetic field and the wavevector are perpendicular. The corresponding fast, short wavelength neutrino beam instability was then obtained in the context of supernova parameters. The present communication generalizes these results, allowing for arbitrary direction of wave propagation, including fast and slow magnetohydrodynamic waves and the intermediate cases of oblique angles. The numerical estimates of the neutrino-plasma instabilities are derived in extreme astrophysical environments where dense neutrino beams exist

Mobile pervasive augmented reality systems the role of user preferences in perceived quality of experience

This work addresses reasons and aspects required to boost the acceptance and use of mobile pervasive augmented reality systems - MPARS - for outdoor applications and the need to develop context-aware close to- real-time feedback mechanisms that take into consideration a continuous measurement of Quality of Experience. For this purpose, we delve into how user preferences can be integrated in context-aware feedback systems, proposing a Quality of Experience theoretical model derived from an analysis on technology adoption models and user preferences. The how and why such model can be integrated into future solutions is also addressed.info:eu-repo/semantics/acceptedVersio

A survey of augmented reality: making technologies acceptable in outdoor environments

Augmented Reality (AR) is an increasingly prevalent subject with various areas of application. This work explores the results of a survey especially developed to document the ease of acceptance of possible characteristics to implement in mobile outdoor applications enhanced with AR. This survey has been devised for a better assessment of user preferences regarding the use of AR in outdoor scenarios. Preference level has been evaluated based on indicators from models concerning various existing and important models. The paper presents the survey results about the preference level in relation the targeted questions and proposes a conceptual framework for feedback on AR technology acceptance.info:eu-repo/semantics/acceptedVersio

Neutrino magnetohydrodynamics

A new neutrino magnetohydrodynamics (NMHD) model is formulated, where the effects of the charged weak current on the electron-ion magnetohydrodynamic fluid are taken into account. The model incorporates in a systematic way the role of the Fermi neutrino weak force in magnetized plasmas. A fast neutrino-driven short wavelengths instability associated with the magnetosonic wave is derived. Such an instability should play a central role in strongly magnetized plasma as occurs in supernovae, where dense neutrino beams also exist. In addition, in the case of nonlinear or high frequency waves, the neutrino coupling is shown to be responsible for breaking the frozen-in magnetic field lines condition even in infinite conductivity plasmas. Simplified and ideal NMHD assumptions were adopted and analyzed in detail

Torsion and Inflammation of Meckel's Diverticulum: Rare Cause of Acute Abdominal Pain

Meckel's diverticulum is a remnant of the embryologic vitelline duct. It was named after its anatomical and embryological description, in the early 19th century, by Johann Meckel. It is known as a true diverticulum of the small bowel and is typically estimated to be present in 2% of the general population, with only a very small percentage being symptomatic. In this report, we present a 14-year-old boy with complaints of abdominal pain, fever, nausea, vomiting and diarrhea. During physical examination we observed peritoneal irritation and raised inflammatory markers. Surgical exploration revealed torsion and inflammation of a large Meckel's diverticulum with a gangrenous area. In order to ensure the removal of etopic tissue, if present, segmental bowel resection with primary anastomosis was performed. Histopathological analysis did not find ectopic tissue. The operative and postoperative courses were uneventful. Meckel's diverticulum is an important differential diagnosis in acute abdominal pain in children.info:eu-repo/semantics/publishedVersio

Transformational leadership contributions for employee autonomy

The performance of a company is affected by several variables and understanding them and knowing how they work is decisive for management. Therefore, this research aims to address and measure how transformational leadership impacts the employees work. To test the conceptual model, we used survey data from 174 active workers. Data was analyzed using PLS-SEM. Our results reveal that leaders who adopt a Transformational approach allow workers to be more autonomous in their work, the autonomy leverage the existence of efficiency in tasks and processes. Efficiency is also reached through cost savings, which translates into a reduction of unproductive work time. Furthermore, results indicate the mediating effect of efficiency and employee autonomy on the relation between transformational leadership and cost savings and between transformational leadership and unproductive work time.info:eu-repo/semantics/publishedVersio

Numerical Thermal Analysis of a T Jump System Used for Studying Polymer Behaviour

Acknowledgements: The authors would like to acknowledge the financial support from Fundação da Ciência e Tecnologia (Portugal) as part of the UC4EP (Understanding Crystallisation for Enhanced Polymer Properties) at CDRSP PTDC/CTM-POL/7133/2014, UID/Multi/04044/2013, PAMI Nº 022158 and the Fundo Europeu de Desenvolvimento Regional (FEDER), Programa Portugal 2020, through the Programa Operacional Regional do Centro 2020 (CENTRO-01-0145-FEDER-022158). The neutron scattering measurement was performed at the STFC ISIS facilities (United Kingdom).The processing of polymers is highly complex. The study of their crystallisation assumes an important role and needs to be carefully detailed. Scattering experiments can be used to study polymer molecular organisation. However these procedures are still very multifaceted leading to the need for planning all the details in the experiments that are to be performed. This manuscript presents a finite element model developed to study the temperature variation of a T Jump System, which has been used for studying polymer behaviour with the NIMROD instrument at the ISIS Neutron and Muon Source, UK. Results show that the variation across the sample was 2ºC at a maximum temperature of 70ºC and 1ºC at a maximum temperature of 50ºC.info:eu-repo/semantics/publishedVersio

Remote sensing depicts riparian vegetation responses to water stress in a humid Atlantic region

Riparian areas in the Cantabrian Atlantic ecoregion (northwest Portugal) play a key role in soil formation and conservation, regulation of nutrient and water cycle, creation of landscape aesthetic value and the preservation of biodiversity. The maintenance of their ecological integrity is crucial given the ever increase in multiple anthropogenic (water demand and agriculture) and climatic pressures (droughts and extreme events). We developed a transferable remote sensing approach, taking advantage of the latest freely available technologies (Sentinel-2 and Copernicus Land products), to detect intra-annual and inter-annual changes in riparian vegetation productivity at the river basin scale related to water stress. This study has used the normalized difference vegetation index (NDVI) to investigate riparian vegetation productivity dynamics on three different vegetation types (coniferous, broadleaved and grassland) over the past 5 years (2015-2019). Our results indicated that inter-annual seasonality differed between drier (2017) and wetter (2016) years. We found that intra-annual dynamics of NDVI were influenced by the longitudinal river zonation. Our model ranked first (r2m = 0.73) showed that the productivity of riparian vegetation during the dry season was positively influenced by annual rainfall and by the type of riparian vegetation. The emergent long lags between climatic variation and riparian plant productivity provides opportunities to forecast early warnings of climatically-driven impacts. In addition, the different average productivity levels among vegetation types should be considered when assessing climatic impacts on riparian vegetation. Future applications of Sentinel 2 products could seek to distinguish riparian areas that are likely to be more vulnerable to changes in the annual water balance from those that are more resistant under longer-term changes in climate.Contrato-Programa UIDB/04050/2020. ERA4CS/0004/2016. CLIMALERT: Climate Alert Smart System for Sustainable Water and Agriculture, an ERA-NET initiated by JPI Climate (ERA4CS programme) co-funded by the EU commission (Grant Agreement 690462) and FCT (ERA4CS/0004/2016). This work was supported by the “Contrato-Programa” UIDB/04050/2020 funded by national funds through the FCT I.P. (GP

Remote sensing indicators to assess riparian vegetation and river ecosystem health

Environmental managers need information to quickly detect which stressor combinations should be addressed to reverse river degradation across large study areas. The pivotal role of riparian vegetation in regulating thermal regimes and inputs of light, nutrients and organic matter has made it a major target of stressor-mitigation and conservation actions. However, due to the dendritic and extensive nature of river networks, field-based monitoring of local riparian conditions is expensive and time-consuming. Ongoing developments in remote sensing offer an unparalleled opportunity to address this challenge. Nonetheless, there is still a limited understanding of the capacity of remote sensing indicators to predict changes in local riparian and river conditions, urging for local calibration with in situ measurements. This study aims to evaluate the capacity of remote sensing to detect impacts on quality elements commonly used in river biomonitoring: riparian vegetation, abiotic river condition and macrophyte biomass. To this end, four remote sensing metrics were tested against field-based indicators in 50 stream locations from four river basins across the Northwest of Portugal: i) the lateral riparian continuity at reach scale (riparian forest buffer width), ii) the riparian vegetation density at reach scale (Normalized Difference Vegetation Index, NDVI100m), and iii) the land use intensification at both reach (LUI100m) and iv) segment (LUI500m) scales. We found that the combination of remote sensing variables (riparian forest buffer width and the land use intensification index) correlated with riparian vegetation quality and dissolved inorganic nitrogen concentrations. We also found that the riparian vegetation density was able to predict changes in vascular plant biomass except for bryophytes. Our study provides new insights on the capacity of satellite-based indicators to assess riparian and river health, illustrating their utility for land and water managers, to identify and monitor, at a reduced cost and time, po- This work was supported by the River2Ocean project (NORTE-01-0145-FEDER-000068), co-financed by the European Regional Development Fund (ERDF), through Programa Operacional Regional do Norte (NORTE 2020).The work was also supported by the "Contrato-Programa" UIDB/04050/2020 funded by national funds through the FCT I.P., the Centre of Molecular and Environmental Biology (CBMA). CG-C was supported by a "Juan de la Cierva -Incoporacion" contract (MINECO, IJC2018-036642-I). CCS was supported by the "Financiamento Programatico" UIDP/04050/2020 funded by national funds through the FCT I.P

Traffic Vertical Signposting: Materials Characterization and Structural Numerical Simulation

Aknowlegements: This work was supported by the project POCI-01-0247-FEDER-010797from the Agency for Competitiveness and Innovation (IAPMEI). In addition, the authors acknowledge the funding from the project UID/Multi/04044/2013 of the Portuguese Foundation for Science and Technology (FCT) and PAMI - ROTEIRO/0328/2013 (Nº 022158).The existing metallic solutions used for vertical traffic signs are associated with higher costs and environmental issues due to their manufacturing and degradation, when compared with polymeric solutions. Thus, the development of vertical signs considering the injection from polymeric materials in order to overcome problems related with sustainability, maintenance costs, and to achieve higher resistance to corrosion assumes nowadays an important role. The use of ecofriendly and innovative products considering the industrial waste combined with synthetic polymers performing the appropriate mechanical properties, can also be studied to find out new solutions that allow to solve the aforementioned problems. Additionally, these innovative vertical signs can contribute to avoid vandalism events related with theft and graffiti activities. This work presents the prior materials investigation and the structural design of vertical signs that are intended to be produced through polymer injection. Three main steps were considered: i) materials research, ii) materials characterisation through the analysis of polycarbonate resin isolated and in different sets of mixtures with different concentrations through tensile testing and static water contact angle measurements to find the optimal material composition; and iii) structural numerical simulation considering polycarbonate resin and using the current standard EN 12899-1 [1] to compute wind resistance, temporary and permanent deflections. Both experimental and numerical results led to an optimized proposal of the vertical signposting structural design.info:eu-repo/semantics/publishedVersio