Effect of current corrugations on the stability of the tearing mode

The generation of zonal magnetic fields in laboratory fusion plasmas is predicted by theoretical and numerical models and was recently observed experimentally. It is shown that the modification of the current density gradient associated with such corrugations can significantly affect the stability of the tearing mode. A simple scaling law is derived that predicts the impact of small stationary current corrugations on the stability parameter $\Delta'$. The described destabilization mechanism can provide an explanation for the trigger of the Neoclassical Tearing Mode (NTM) in plasmas without significant MHD activity.Comment: Accepted to Physics of Plasma

The effectiveness of e-word-of-mouth communication about smartphones purchase intention: digital influencer

This study aims to compare the effectiveness of eWOM on Facebook, Instagram and YouTube for smartphone buying decision, provided by digital influencers. For such, a quantitative methodology was adopted using three online questionnaires (one for each social media platform), to be answered by Portuguese adults who use them. This comparison has foundation on the IACM, a model introduced by Erkan and Evans to explore the influence of eWOM on consumer's buying intentions. The results show that, while the eWOM information from digital influencers about smartphones has a global consumer receptivity in the three social media platforms considered, that is not happening in a very assertive way for some items [average not greater than 3 (Likert scale 1-5)], in a significant statistically way. The research also demonstrate that YouTube or Instagram are more effective than Facebook in the IACM variables 'information quality', 'information credibility', 'information usefulness', 'positive buying intention with digital influencer positive information' and 'negative buying intention with digital influencer negative information'.info:eu-repo/semantics/acceptedVersio

Evaluation of bone mineral density in cystic fibrosis patients

Patients with cystic fibrosis (CF) have an increasing life span and osteoporosis has become a more recognised problem in these patients. The pathogenesis of low bone mineral density (BMD) in CF seems to be multifactorial and the aim of this study was to assess the prevalence of low BMD in a group of CF outpatients and to relate the findings with the variables studied. The study included 22 patients aged between 14 and 45 years (mean age 26.3). Two of the subjects were lung transplant patients. BMD was assessed by dual-energy X-ray absorptiometry (DEXA) at the lumbar spine (LS) and femoral neck (FN). This data was correlated with serum 25-hydroxy vitamin D (25-OHD) levels, BMI and the forced expiratory volume in one second (FEV1). BMD (Z-score and T-score) ranged from 0.6 to -6 and from 0.5 to -6.7 at LS; at FN the scores ranged from 0.6 to -3.9 and from 0.6 to -4.1. The mean serum 25-OHD concentration (12,57 ng/ml) was at the low end of the normal range (10-60 ng/ml). On average patients did not present with malnutrition, however BMI ranged from 15.2 to 33.7 kg/m2. Lung function status was assessed by FEV1; 64% of patients had FEV1 below 80% and within this group four patients had a FEV1 under 40%. There was a positive correlation between low BMD and 25-OHD concentrations and also between BMD and FEV1. There was no linear correlation between BMD and BMI

Virtual reality and gamification in marketing higher education: A review and research agenda

Purpose – The purpose of this paper is to review studies on the use of virtual reality (VR) and gamification to engage students in higher education for marketing issues to identify the research topics, the research gaps and to prepare a future research agenda. Design/methodology/approach – A literature review is performed based on two search terms applied to Web of Science, resulting in a final pool of 115 articles. A text-mining approach is used to conduct a full-text analysis of papers related to VR and gamification in higher education. The authors also compare the salient characteristics presented in the articles. Findings – From this analysis, five major research topics are found and analysed, namely, teaching methodologies and education, experience and motivation, student engagement, applied theories in VR and gamification. Based on this and following the theory concept characteristics methodology framework, the paper provides directions for future research. Originality/value – There is no comprehensive review exploring the topics, theories, constructs and methods used in prior studies concerning VR and gamification applied to higher education services based on all the articles published in well-regarded academic journals. This review seeks to provide deeper insights, to help scholars contribute to the development of this research field.info:eu-repo/semantics/publishedVersio

Creating memories and engagement in college student through virtual reality

This study intends to extend the understanding of drivers of student engagement in the educational context and analyse mindfulness as a moderator of the different associations in the proposed model. The proposed model regards VR experiences as stimuli, telepresence, pleasantness of the experience and memory as an organism and student engagement as the response. A sample of 136 participants allowed us to test the model. Findings revealed that all hypotheses were supported except H6 linking pleasantness of the experience with student engagement. Only the relationship between pleasantness and memory is higher for mindful students than nonmindful ones. These findings mean that students do not need to feel pleasure about what they are learning to be engaged.info:eu-repo/semantics/acceptedVersio

Robotic Tankette for Intelligent BioEnergy Agriculture: Design, Development and Field Tests

In recent years, the use of robots in agriculture has been increasing mainly due to the high demand of productivity, precision and efficiency, which follow the climate change effects and world population growth. Unlike conventional agriculture, sugarcane farms are usually regions with dense vegetation, gigantic areas, and subjected to extreme weather conditions, such as intense heat, moisture and rain. TIBA - Tankette for Intelligent BioEnergy Agriculture - is the first result of an R&D project which strives to develop an autonomous mobile robotic system for carrying out a number of agricultural tasks in sugarcane fields. The proposed concept consists of a semi-autonomous, low-cost, dust and waterproof tankette-type vehicle, capable of infiltrating dense vegetation in plantation tunnels and carry several sensing systems, in order to perform mapping of hard-to-access areas and collecting samples. This paper presents an overview of the robot mechanical design, the embedded electronics and software architecture, and the construction of a first prototype. Preliminary results obtained in field tests validate the proposed conceptual design and bring about several challenges and potential applications for robot autonomous navigation, as well as to build a new prototype with additional functionality.Comment: 9 pages, 15 figure

Numerical study of the plastic behaviour in tension of welds in high strength steels

The influence of the mismatch between material properties and constraint on the plastic deformation behaviour of the heat affected zone of welds in high strength steels is investigated in this study, using finite element simulations. An elastoplastic implicit three-dimensional finite element code (EPIM3D) was used in the analysis. The paper presents the mechanical model of the code and the methodology used for the numerical simulation of the tensile test of welded joints. Numerical results of the tensile test of welded samples with different hypothetical widths for the Heat Affected Zone and various material mismatch levels are shown. The analysis concerns the overall strength and ductility of the joint and in relation to the plastic behaviour of the heat affected zone. The influence of the yield stress, tensile strength and constraint on the stress and plastic strain distribution in the soft heat affected zone is also discussed.http://www.sciencedirect.com/science/article/B6TWX-47G3PVT-2/1/f1caf121d3e6678da6f3259e6d795cd

The impact of massclusivity campaigns on perceptions and brand love of Gucci online brand communities’ members

The current research aims to understand the impact of Massclusivity (massive and exclusive) campaigns on the brand love through online brand communities (OBC) interactions. Authors designed a netnography research with the purpose of analysing the interactions between a brand - the luxury fashion brand Gucci – and its online brand community on Facebook, during a specific period of time defined according to the launch of a Massclusivity campaigns of this brand. We collect a total of 10,689 interactions from March 2017 to March 2018. Findings highlight that the development of massclusivity campaigns have several impacts, such as generate awareness towards the brand, increases consumers’ engagement on SNP, and promotes communities’ expansion. These are directly connected to the interest that this type of marketing strategies generates towards the brands, which may be considered powerful to luxury brands who intend to diversify their audience and become more competitive

Efeito da reinoculação e da adubação nitrogenada no rendimento da soja em Mato Grosso.

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