Hybrid Localized Spectral Decomposition for multiscale problems

We consider a finite element method for elliptic equation with heterogeneous and possibly high-contrast coefficients based on primal hybrid formulation. A space decomposition as in FETI and BDCC allows a sequential computations of the unknowns through elliptic problems and satisfies equilibrium constraints. One of the resulting problems is non-local but with exponentially decaying solutions, enabling a practical scheme where the basis functions have an extended, but still local, support. We obtain quasi-optimal a priori error estimates for low-contrast problems assuming minimal regularity of the solutions. To also consider the high-contrast case, we propose a variant of our method, enriching the space solution via local eigenvalue problems and obtaining optimal a priori error estimate that mitigates the effect of having coefficients with different magnitudes and again assuming no regularity of the solution. The technique developed is dimensional independent and easy to extend to other problems such as elasticity

Middle East and the global oil pricing system

this book explains how the Middle East became a new geographical base point for petroleum transactions, and the hub of the global pricing system. The sudden discovery of several Middle East giant oilfields (1943-1947) along with the disclosure of the region’s reserves potential, turned the global pricing equilibrium harder to sustain. Given the potential petroleum reserves in the Persian Gulf, 1950 constituted the breakthrough moment for the consolidation of a global oil pricing system that interlinked Middle East production centers in the Eastern hemisphere with the American and Caribbean oilfields in the Western hemisphere.info:eu-repo/semantics/publishedVersio

The anxiety of abundance: William Stanley Jevons and coal scarcity in the nineteenth century

WOS:000321225400005 (Nº de Acesso Web of Science)Right from the outset, the adoption of mechanical machinery, railways, steamships and long distance communications was accompanied by growing concerns about the possibility of running out of coal. This article examines three main issues: firstly, what triggered the scarcity fear, given that the historical period was one of rising prosperity with no foreseeable shortages in sight; secondly, what actually went wrong with the coal supply vision given so many of the forecasts associated with the scarcity thesis were not borne out by reality; and thirdly, by what means did the nineteenth century coal debate shape environmental thinking and provide crucial concepts that have persisted through to the present (the rebound effect, probable reserves and environmental limits to growth). A close look is taken of the work of William Stanley Jevons, whose ideas became a milestone in the debate on the depletion of natural resources. The overall conclusion points out that the looming uncertainty of the 1860s and 1870s paved the way for new probabilistic assessments of mineral patrimony

Borders and transit countries: The re-territorialization of Middle East pipelines

Following the discovery of vast oil reserves in the Persian Gulf region, the Middle East became the main hub for the expansion and development of western pipeline technology. Contrary to the borderless world described in some accounts of globalization, what is observed after 1956 is the establishment of hard political borders, directly under the oversight of national governments, for pipeline deployment with minimal boundary crossings. In the Middle East, this minimal permeability of frontiers entailed fewer risks compared with the uncertainties arising from having to cross several countries: the sovereign state thus seemed the best container for oil transportation. The conclusion puts forward the concept of re-territorialization to explain the multi-level changes that took place, entailing shifts in geography, in business structures and in international relations.info:eu-repo/semantics/publishedVersio

Impact of social media influencers on the Portuguese tourism and travel industry in a Covid-19 era

The way society communicates with each other has gone through huge changes during the years. This has led to a revolution on the process of gather and exchange information by the consumers regarding brands, products, and services. Nowadays, any person can express their opinion on their social media accounts and share it with whoever he/she wants on a global scale. It is here that Social Media Influencers (SMIs) appear, anyone with a considerably large audience on social media has the ability to influence many others to take an action. Currently, the Tourism and Travel (T&T) industry is facing unprecedented challenges due to the Covid-19 pandemic; being one of the biggest sectors worldwide, driving socioeconomic development and job creation is vital for this industry to recover as faster as possible. Many actions are being done to make that happen and one possible great tool is SMI. Shortly, this research aims to understand if SMIs can boost the T&T industry by showing that a destination and its tourism services/products are safe in this time of fear of travelling due to the pandemic.info:eu-repo/semantics/acceptedVersio

The role of Hypoxia in Glioblastoma radiotherapy resistance

Glioblastoma (GB) (grade IV astrocytoma) is the most malignant type of primary brain tumor with a 16 months median survival time following diagnosis. Despite increasing attention regarding the development of targeted therapies for GB that resulted in around 450 clinical trials currently undergoing, radiotherapy still remains the most clinically effective treatment for these patients. Nevertheless, radiotherapy resistance (radioresistance) is commonly observed in GB patients leading to tumor recurrence and eventually patient death. It is therefore essential to unravel the molecular mechanisms underpinning GB cell radioresistance in order to develop novel strategies and combinational therapies focused on enhancing tumor cell sensitivity to radiotherapy. In this review, we present a comprehensive examination of the current literature regarding the role of hypoxia (O2 partial pressure less than 10 mmHg), a main GB microenvironmental factor, in radioresistance with the ultimate goal of identifying potential molecular markers and therapeutic targets to overcome this issue in the future.info:eu-repo/semantics/publishedVersio