Abstract
<p>Ambient radioactivity reflects a wide range of physical processes, including atmospheric and geological processes, as well as space weather and solar conditions. Gamma radiation near the Earth’s surface comes from diverse sources, including space (cosmic radiation), the earth’s atmosphere, and solid earth. In addition to the terrestrial gamma radiation originating from the radioactive decay of primordial radionuclides present in every soil and rock, gamma radiation is also continuously produced in the atmosphere from the interaction of secondary cosmic rays and upper-atmosphere gases, as well as from the decay of airborne radon (Rn-222) progeny. Therefore the temporal variability of gamma radiation contains information on a wide range of physical processes and space-earth interactions, but disentangling the different contributions remains a challenging endeavor. Continuous monitoring of gamma radiation at sea enables to remove both the terrestrial and radon exhalation contributions, allowing to examine in detail the space and atmospheric sources of ambient gamma radiation.</p><p>Gamma radiation over the Atlantic Ocean was measured on board the ship-rigged sailing ship NRP Sagres in the framework of the SAIL (Space-Atmosphere-Ocean Interactions in the marine boundary Layer) project. The measurements were performed continuously (every 1-second) with a NaI(Tl) scintillator counting all the gamma rays from 475 keV to 3 MeV. The casing of the instrument was adapted in order to endure the harsh oceanic conditions and installed in the mizzen mast of the ship. The counts were linked to a rigorous temporal reference frame and precise positioning through GNSS.</p><p>Here preliminary results based on the gamma radiation measurements performed from January 5<sup>th</sup> to May 9<sup>th </sup>2020 are presented, corresponding to the journey of the ship from Lisboa to Cabo Verde, Rio de Janeiro, Montevideu, Cape Town, and back to Lisboa. The data exhibit a clear transition from the coastal to the marine environment, enabling to study in detail the temporal variation of gamma radiation in the marine boundary layer, as well as the interface between land and marine conditions in terms of environmental radioactivity.</p>

Abstract
<p>The marine boundary layer offers a unique opportunity to investigate the electrical properties of the atmosphere, as the effect of natural radioactivity in driving near surface ionization is significantly reduced over the ocean, and the concentration of aerosols is also typically lower than over land. This work addresses the temporal variability of the atmospheric electric field in the South Atlantic marine boundary layer based on measurements from the SAIL (Space-Atmosphere-Ocean Interactions in the marine boundary Layer) project. The SAIL monitoring campaign took place on board the Portuguese navy tall ship NRP Sagres during its circumnavigation expedition in 2020.  Two identical field mills (CS110, Campbell Scientific) were installed on the same mast but at different heights (about 5 and 22 meters), recording the atmospheric electric field every 1-second. Hourly averages of the atmospheric electric field are analyzed for the ship’s leg from 3<sup>rd</sup> to 25<sup>th</sup> March, between Buenos Aires (South America) and Cape Town (South Africa). The median daily curve of the electric field has a shape compatible with the Carnegie curve, but significant variability is found in the daily pattern of individual days, with only about 30% of the days exhibiting a diurnal pattern consistent with the Carnegie curve.</p>

Abstract

Abstract
Information and communication technologies provide their users with permanent global connectivity through a wide range of devices and with the Internet as their main support. Currently assuming a very significant economic relevance for a considerable group of countries, the Tourism sector is in the mindset of a digital transformation, in the scope of which a good part of its services is evolving towards ICT and Internet supported versions. In this context, the assurance of universal access to websites (Web accessibility) that support the businesses of organizations in this sector gains special relevance. This article presents an analysis at the level of Web accessibility of 240 websites directly related to the tourism sector, using TAW-Test de Acessibilidad Web evaluation tool. Despite the growing concern to provide more and more inclusive means, the overwhelming majority of websites did not reach the minimum level of accessibility, thus not assuring properly functional access for those who have a disability or limitation. © 2021 AISTI.

Abstract
This exploratory study aims to shed light on the e-commerce phenomenon and the impact of the pandemic COVID-19, namely in a period of social distancing and isolation. We study two prominent examples, via secondary data: Japan and the USA. We then analyze digital consumption behaviors and patterns in Portugal. For this, a questionnaire was created - using Google Forms - where both quantitative and qualitative perspectives were gathered. The research sample was a convenience sample, popular in business research, and it included 185 responses from Portuguese citizens. Through a cautious analysis of the primary data obtained, it was possible to compare the consumption levels in an ante- and post-COVID-19 context; what type of products are the most pursued; by whom they are most sought after; what are the most used platforms; and, additionally, the satisfaction levels regarding the use of these platforms. No statistically significant association (chi-square statistic) was found between gender or age and the preference for physical versus online stores. The data also uncovers that there is still a general preference for a more secure, traditional way of life in Portugal due to the fact that people still reveal some insecurities and fears regarding shopping through the Internet and a preference to buy in physical stores, which clearly leads people, in general, to buy online not so regularly as in other countries. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Abstract
The need to implement a new development dynamic in rural regions has been one of the concerns of the rural tourism sector, which is currently starting its digital transformation process and the adoption of digital technologies and tools. In the light of literature, one of the tools with the greatest promotion potential is digital marketing, since it allows reaching new and larger target audiences more efficiently and effectively. Realizing the lack of a conceptual and functional vision capable of guiding the planning and execution of digital marketing initiatives in the context of rural tourism, this article proposes a conceptual model focused on characterizing the potential impact that digital marketing initiatives can generate, namely in terms of the development of a positive image of the rural tourism destination and of the influence on the tourists' decision to visit.