103 research outputs found
Conceptualizing and illustrating the digital lifestyle of youth
This research looks at the psychosocial content and nature of the concept of the digital lifestyle when applied to pre-teens and teenagers. The concept of lifestyle is analyzed to assess whether the digital technological context is an acceptable framework to characterize the daily life of pre-teens and teenagers. Five dimensions of the digital lifestyle concept were useful to structure more than 200 technologically aware young consumers who discussed the meaning and usage of several digital devices.Consumer psychology, Internet, teenagers
Petrology and geochemistry of the igneous rocks from Macao (South China) : Tectono-magmatic implications
The territory of Macao is composed of several granitic intrusions belonging to one of the biggest granite provinces in the world, the Southeast China Magmatic Belt (SCMB), located in the southeast (SE) area of the Cathaysia Block. The SCMB is known by the occurrence of large volumes of Mesozoic magmatic rocks (over 90% are granitic rocks and equivalent volcanic rocks with minor basalts), occupying a total outcrop area of nearly 200.000 km2. The geology of Macao (~30 Km2) is dominated by granitic rocks displaying a wide range of textural, mineralogical and chemical features, making it an ideal region to study these rocks and the petrogenetic processes responsible for their diversity.
This study employed a wide range of research methodologies, namely field studies, petrography, zircon geochronology, mineral chemistry, whole-rock elemental and isotopic geochemistry to determine the nature of the source, the petrogenetic processes and the tectonic regimes of the Mesozoic magmatism in this region. Thus, the data collected along this study aims to provide new knowledge on the tectono-magmatic evolution of Macao, in particular, and of SE China, in general.
The results obtained from the high-precision U–Pb zircon geochronology, acquired through isotope dilution thermal ionization mass spectrometry (ID-TIMS) and in-situ laser ablation multi-collector inductively coupled mass spectrometry (LA-MC-ICPMS), revealed different ages for Macao granites. Despite its relatively small area, the determined ages tightly constrain the Macao granitic magmatism to two periods, ranging from 164.5 ± 0.6 to 162.9 ± 0.7 Ma (MGI – Macao Group I granites) and 156.6 ± 0.2 to 155.5 ± 0.8 Ma (MGII – Macao Group II granites). In addition, younger dacitic rocks were dated at 150.6 ± 0.6 Ma and <120 Ma. The existence of two proximal but distinct granitic pulses, spanning for a time of about 9 Ma and separated by ca. 6 Ma, in the Macao granitic suite suggests that it was incrementally assembled. This hypothesis is also extendable to the neighbouring Hong Kong region, where the magmatic activity occurred in four major pulses spanning for about 24 Ma. However, the MGII granites indicate the occurrence, on the Pearl River Delta region, of a magmatic pulse between those defined in Hong Kong at the origin of Lamma Suite (165–160 Ma) and the Kwai Chung Suite (148–146 Ma). In addition, Rare Element Earth (REE) ratios suggest that this pulse may only occur in Macao area, while MGI granites show evolving trends of REE ratios similar to those of Jurassic granites outcropping in vast areas of the Cathaysia Block (SE China). Inheritance patterns in the zircon U–Pb data indicate the presence of a population of antecrysts (165–180 Ma) crystallized from earlier magmatic pulses and a population of inherited zircons, from Precambrian to Phanerozoic sources, incorporated into the magmas during melting and/or ascent/emplacement at crustal levels. The oldest inherited ages (2.4 Ga and possibly 2.9 Ga) suggest contribution of Proterozoic and possibly of late Archaean crustal sources for the Macao magmatism.
The granitic rocks of Macao are mainly high-K calc-alkaline metaluminous to weakly peraluminous I-type granites with variable degrees of fractionation. Fractional crystallization played an important role in the evolution of these granites, though the fractionation paths differ for the highly fractionated facies of both groups mainly due to distinct accessory fractionating phases. Such difference is evident by distinct REE evolution trends: while MGI magmas seem to have evolved by gradual enrichment in heavy REE relatively to light REE, originating progressively flatter REE patterns, magmas from MGII are marked by depletion of middle REE, leading to progressively concave upward REE patterns. However, while most of the geochemical variation of the MGII granites can be explained by fractional crystallization, the same is not true for MGI granites. The MGI highly fractionated granites show evidence for the REE tetrad effect and are characterized by non-CHArge-and-RAdius-Controlled (non-CHARAC) behaviour of trace elements, suggesting late-stage melt/fluid interactions involving F-rich fluids. The stage of evolution represented by the MGI highly fractionated granites corresponds to the onset of fluid/melt interaction in a highly evolved granitic system, which may have led to enhanced hydrothermal activity in more evolved stages, as those represented in neighbouring areas in SE China. Significant differences in isotopic composition were also observed, with the MGII being characterized by a much narrow range of initial 87Sr/86Sr ratios and εNd(t) and εHf(t) values than MGI. Based on these differences, the MGII granites are considered to be part of a comagmatic suite that has evolved in closed system, contrasting with what can be inferred for MGI. The increase in initial 87Sr/86Sr ratios with degree of evolution, the presence of metasedimentary enclaves and the high percentage of inherited zircon with Paleozoic ages in MGI, suggest the occurrence of an assimilation fractionation crystallization (AFC) process. The AFC processes were a major cause for the I-S transitional characteristics of the MGI highly fractionated granites and possibly of the other similar Jurassic biotite granites in SE China. The observed decoupling of Sr, Nd and Hf isotope systems might have resulted from magma mixing between the granitic and more mafic magmas, which caused the homogenization of Sr isotope ratios but not of the Nd and Hf ones. Such process is also supported by the occurrence of Microgranular Mafic Enclaves (MME) hosted by the granites.
Isotope and major element compositions together with model ages strongly suggest that Macao granitic magmas were generated by partial melting of infracrustal medium-to-high K basaltic Paleo-Proterozoic to Mesoproterozoic protoliths heated by, and mixed to some degree with mantle-derived magmas. The temporal and spatial association of Macao and SE China Jurassic I-type granites with basaltic/gabbroic rocks, syenites and A-type granites, displaying typical intraplate chemical features, indicates an extensional regime rather than an active margin for the origin of these rocks. It also points to an important role of mantle-derived magmas in the production of SE China Jurassic granites. Adiabatic decompression melting of the asthenospheric mantle produced mafic magmas, which underplated at the base of the crust (Moho), subsequently triggering partial melting of the lower crust to generate the granitic magmas. The Jurassic Macao granites are interpreted as being produced in an intraplate extensional setting related to the break-off and foundering of a previously flat-slab (Paleo-Pacific plate) beneath the Eurasian plate.
The boundary between east and west Cathaysia blocks is roughly along the Zhenghe-Dapu Fault (ZDF), which intersects the SE China coast near Hong Kong and is thought to have played a major role for the Mesozoic magmatic activity in this region. The stronger isotopic affinities of Macao granites with the other granitic rocks and lower crustal xenoliths from the western Cathaysia Block suggest that the ZDF is likely to pass south of Macao, a fact that has not been mentioned before.
In addition to the Early Yanshanian (Jurassic) granitic magmatism in Macao, the younger ages obtained for the dacite dykes indicate that the territory was also affected, to a lesser degree, by Late Yanshanian (Cretaceous) magmatism. The transition from granitic to dacitic magmatism most likely corresponds to a change in the regional tectonic regime, which induced a significant change in the magma genesis processes. In contrast with the intraplate features of Macao and SE China Jurassic granites and coeval mafic rocks, the geochemical features of the Macao dacite dykes (e.g. high LILE/HFSE ratios and negative anomalies of Nb, Ta and Ti) are identical to those characterizing arc-like subduction-related magmas. These dacites are most likely evolved products of arc-like magmatism and may testify the reestablishment of a normal subduction system in this area of SE China
A dyadic approach to adolescents’ risky online behaviors
This research analyzes the discrepancies respecting parents' and their children's perspectives on adolescents' risky online behaviors and parental mediation. Rather than focus solely on youth outcomes, this study explores dyadic data, by comparing reports from adolescents attending 7th to 12th grades in Portuguese schools and those of their parents (N=1016). Moreover, this research considers the existence of defense mechanisms influencing adolescents' reports, a factor that has been neglected in previous studies. Differences regarding adolescents' gender, parents' gender, and adolescents' school year are considered and tested using One-way ANOVA. Within the family unit, the only members considered by adolescents to have the same or more online and computer skills than the teenagers themselves are their older siblings. Practical implications aiming to mitigate the risk involved in adolescents' online experiences, and theoretical contributions to the field of prevention and youth well-being in the context of consumer behavior in the digital age are discussed.FCT-Foundation for Science and TechnologyPortuguese Foundation for Science and Technology [UIDB/04020/2020]info:eu-repo/semantics/publishedVersio
Augmented Reality Trends to the Field of Business and Economics: A Review of 20 years of Research
Augmented Reality (AR) is emerging as a technology that is reshaping the current
society, especially the fields of Business and Economics (B&E). Therefore, the
scientific studies produced on AR call for an interdisciplinary systematic review of
the knowledge generated to structure an organized framework. Three main questions
are addressed: How has the production of AR scientific knowledge evolved? What
user-related aspects does AR affect? Also, which set of subtopics is associated with
each motivation to develop an AR solution? The content of 328 papers produced
between 1997 and 2016 in the field of AR is analyzed, unveiling 58 coding categories.
There are 13 digital media characteristics that assume instrumental roles in addressing
four major motivations to develop AR solutions. Technological topics dominate the research focus over behavioral ones. The investigations on AR in mobile displays show the highest increase. This research identifies the main scientific topics that have led researchers' agenda. Consequently, they contributed to develop and to adopt AR solutions and to forecast its future application in the organizations' strategiesinfo:eu-repo/semantics/publishedVersio
The Evolution of Azuma’s Augmented Reality– An Overview of 20 Years of Research
Augmented Reality (AR) is no longer just a gimmick. 50 years after
the development of the first head-mounted display, and approaching the 20th
anniversary of the first conference dedicated to AR, it is time for a new review on the theme. As such, we present a bibliometric analysis of scientific literature since 1997, using as database the Web of Science. This allowed identifying the most relevant authors, their distribution by subjects, the evolution of publishing
by year and the most frequent publications.info:eu-repo/semantics/publishedVersio
I see myself, therefore I purchase: factors influencing consumer attitudes towards m-commerce AR apps
Mobile commerce (m-commerce) is starting to represent a significant share of e-commerce.
The use of Augmented Reality (AR) by brands to convey information about their products -
within the store and mainly as mobile apps – makes it possible for researchers and managers to
understand consumer reactions. Although attitudes towards AR have been studied, the overall
effect of distinct aspects such as the influence of others, the imagery, projection and perceived
presence, has not been tackled as far as we know. Therefore, we conducted a study on 218
undergraduate students, using a pre-test post-test experimental design to address the following
questions: (1) Do AR media characteristics affect consumer attitudes towards the medium in a
mobile shopping context? Also, (2) Do the opinion and physical presence of people influence
the attitude towards an m-commerce AR app? It found that AR characteristics such as
projection and imagery positively influence attitudes towards m-commerce AR apps, whereas
social variables did not have any influence.info:eu-repo/semantics/publishedVersio
Análise da calendarização dos jogos e das assistências da liga NOS
O produto futebolístico português é bom e apetecível, no entanto, ainda está longe do produto de outras ligas e urge potencia-lo.Um dos fatores que urge potenciar, é o das assistências nos estádios de futebol. Um dos fatores que potencia essas assistências é a calendarização. Assim, neste projeto profissional de mestrado é delineado um retrato da atual calendarização da principal competição sob o desígnio da LPFP, a Liga NOS, bem como das respetivas assistências, recorrendo a uma divisão por dia da semana, bloco horário e bloco horário por dia da semana, com o intuito de identificar os principais blocos horários e os que possuem a melhor média de assistência. Esta investigação foi realizada através de uma análise de dados secundários disponibilizados pela LPFP
Vessel Segmentation and Branching Detection using an Adaptive Profile Kalman Filter in Retinal Blood Vessel Structure Analysis
This paper presents an improved tracking based method for retinal vessel segmentation that uses blood vessel morphology to adapt the tracking parameters. The method includes branching detection and avoidance methods. A bi-level threshold method, based on local vessel information, is used for segmentation. Tracking is based on Kalman filtering. The results are compared with existing ground truth. It is concluded that ground truth segmentation is not easily comparable
Enzymatic time-temperature integrator device for chromatic quality check of Cova da Beira’s cherry (Portugal)
Cherry is a fruit widely appreciated by consumers in general. In Portugal, within the Beira Interior region, and particularly, Cova da Beira, is the most representative area with a production of more than 50% of the national production. The peculiar characteristics of cherries, such as color, firmness, palate, among others, increase the demand for this fruit, which can only be commercialized during a short period. Its high perishability interferes with the shelf life and consequently generates undesirable changes in the cherry flow chain. In order to ensure food quality and safety and prevent food waste, a time-temperature integrator (TTI) device to monitor the quality of the cherry in real time is proposed. This device suffers a chromatic change with the temperature variation over time. For the specific case of the cherry, the kinetic parameters for thermal inactivation are determined which leads to the proposal of an enzymatic-type TTI, where the degradation of the phenolic compounds occurs, which are substrates of the polyphenol oxidase enzyme, whose hydroxylation reaction of a monophenol in o-diphenol leads to the oxidation in o-Quinone. This device aims to help retailers to decide when and where to sell the food items taking into account the remaining shelf life, as well as support the decision of purchase by the consumer predicting through a chromatic and expedite stamp the food quality and safetyinfo:eu-repo/semantics/publishedVersio
Plano de marketing estratégico para a ostra do Rio Sado e Rio Mira
Relatório de Dissertação de investigação do Mestrado em Ciências Empresariais ramo Gestão de Pequenas e Médias EmpresasO setor de atividade da Ostreicultura é um setor muito importante no contexto económico e histórico das zonas em estudo, rio Mira e rio Sado, nomeadamente o estuário do Sado na região de Setúbal onde tem uma grande e antiga tradição. Relevante citar que Portugal, no presente ano de 2019, foi considerado pela 3ª vez, o melhor destino turístico do mundo, por ter ótimas condições climatéricas, gastronomia de renome internacional, excelentes infraestruturas de alojamento, experiência em receber eventos internacionais, riqueza natural e cultural, e por isso, faz de Portugal um destino atrativo. Este trabalho, foi realizado no âmbito do projeto de investigação do Instituto Politécnico de Setúbal com o nome “Ostraqual”, e tem como objetivo criar um plano de marketing estratégico para promover a ostra do Rio Sado e Rio Mira na região do Alentejo, aumentar a sua notoriedade no mercado, atrair novos clientes, bem como potencializar os recursos e a economia da região. Este sector foi o selecionado para este trabalho, porque revela ser uma oportunidade de negócio com muitas potencialidades por explorar. Adicionalmente, procura também contribuir para o aprofundamento da temática do plano de marketing, estruturando-o em várias fases. Este trabalho encontra-se dividido em duas partes: A primeira (Capítulos 1,2 e 3), pretende enquadrar e fundamentar teoricamente o tema “plano de marketing” e o setor da aquicultura, especificamente a ostreicultura, e referir as metodologias utlizadas para o trabalho; Na segunda parte (Capítulos 4,5 e 6), apresenta-se a estrutura sistemática do plano com aplicação prática, onde se analisa a realidade do setor da ostreicultura e as empresas, e estabelece-se e um programa de ações com orçamentação e avaliação. Por fim, temos as considerações finais, onde se descreve as dificuldades encontradas duração a elaboração do trabalho, e futuras sugestões para próximos trabalhosThe Ostreiculture sector activity is a very important sector in the economic and historical
context of the areas under study, Mira river and Sado river, namely the Sado estuary in the Setúbal
region where it has a great old tradition.
It is relevant to mention that Portugal, in the present year of 2019, was considered for the 3rd
time, the best tourist destination in the world, for having excellent weather conditions, internationally
renowned cuisine, excellent accommodation infrastructure, experience in hosting international
events, natural and cultural richness, and therefore, makes Portugal an attractive destination.
This work was carried out as part of the research project of the Setúbal Polytechnic Institute
under the name “Ostraqual”, and aims to create a strategic marketing plan to promote the Rio Sado
and Rio Mira oysters in the Alentejo region, to increase the reputation in the market, attract new
customers, as well as leverage the region's resources and economy. This sector was selected for this
work because it proves to be a business opportunity with many untapped potentials.
Additionally, it also seeks to contribute to deepening the theme of the marketing plan,
structuring it in several phases.
This paper is divided into two parts:
The first (Chapters 1,2 and 3), aims to frame and theoretically substantiate the theme
“marketing plan” and the aquaculture sector, specifically oyster farming, and refer to the
methodologies used for the work;
In the second part (Chapters 4,5 and 6), the systematic structure of the plan with practical
application is presented, which analyzes the reality of the oyster farming sector and the companies,
and establishes a program of actions with budgeting and evaluation.
Finally, we have the final considerations, which describe the difficulties encountered during the
preparation of the work and future suggestions for future work
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