Institution
Instituto Superior Técnico
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About: Instituto Superior Técnico is a based out in . It is known for research contribution in the topics: Catalysis & Finite element method. The organization has 10085 authors who have published 30226 publications receiving 667524 citations. The organization is also known as: IST & Instituto Superior Tecnico.
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Papers
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TL;DR: In this paper, the use of organic solvent nanofiltration (OSN) as a general platform for the removal of genotoxic impurities (GTI) used as reactants or formed during the synthesis of active pharmaceutical ingredients (API) or their intermediates was discussed.
137 citations
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TL;DR: In this article, the shadow of a black hole with scalar hair was derived for a ZAMO observer at an arbitrary position, using the backward ray-tracing algorithm.
Abstract: For an observer, the Black Hole (BH) shadow is the BHs apparent image in the sky due to the gravitational lensing of nearby radiation, emitted by an external source. A recent class of solutions dubbed Kerr BHs with scalar hair possess smaller shadows than the corresponding Kerr BHs and, under some conditions, novel exotic shadow shapes can arise. Thus, these hairy BHs could potentially provide new shadow templates for future experiments such as the Event Horizon Telescope. In order to obtain the shadows, the backward ray-tracing algorithm is briefly introduced, followed by numerical examples of shadows of Kerr BHs with scalar hair contrasting with the Kerr analogues. Additionally, an analytical solution for the Kerr shadow is derived in closed form for a ZAMO observer at an arbitrary position.
137 citations
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TL;DR: In this paper, the authors provide an introductory-level overview of the recent developments in reconnection theory and simulations that led to this essentially new framework, and describe some of the outstanding challenges that remain at the frontier of this subject.
Abstract: (abridged) Magnetic reconnection is the topological reconfiguration of the magnetic field in a plasma, accompanied by the violent release of energy and particle acceleration. Reconnection is as ubiquitous as plasmas themselves, with solar flares perhaps the most popular example. Over the last few years, the theoretical understanding of magnetic reconnection in large-scale fluid systems has undergone a major paradigm shift. The steady-state model of reconnection described by the famous Sweet-Parker (SP) theory, which dominated the field for ~50 years, has been replaced with an essentially time-dependent, bursty picture of the reconnection layer, dominated by the continuous formation and ejection of multiple secondary islands (plasmoids). Whereas in the SP model reconnection was predicted to be slow, a major implication of this new paradigm is that reconnection in fluid systems is fast (i.e., independent of the Lundquist number), provided that the system is large enough. This conceptual shift hinges on the realization that SP-like current layers are violently unstable to the plasmoid instability - implying, therefore, that such current sheets are super-critically unstable and thus can never form in the first place. This suggests that the formation of a current sheet and the subsequent reconnection process cannot be decoupled, as is commonly assumed. This paper provides an introductory-level overview of the recent developments in reconnection theory and simulations that led to this essentially new framework. We briefly discuss the role played by the plasmoid instability in selected applications, and describe some of the outstanding challenges that remain at the frontier of this subject. Amongst these are the analytical and numerical extension of the plasmoid instability to (i) 3D and (ii) non-MHD regimes. New results are reported in both cases.
137 citations
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TL;DR: In this article, a literature review concerning the fresh properties of concrete containing recycled aggregates from beneficiated construction and demolition wastes is presented, where the authors identify the main variables affecting the workability of concrete, such as the quality and moisture state of the aggregates.
137 citations
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TL;DR: In this paper, the first example of Mn(i)-catalysed hydrogenation of CO2 to HCOOH was reported, achieving TONs up to 10,000 and quantitative yields after 24 h using DBU as the base at 80 °C and 80 bar total pressure.
Abstract: The catalytic reduction of carbon dioxide is of great interest for its potential as a hydrogen storage method and to use carbon dioxide as C-1 feedstock. In an effort to replace expensive noble metal-based catalysts with efficient and cheap earth-abundant counterparts, we report the first example of Mn(i)-catalysed hydrogenation of CO2 to HCOOH. The hydride Mn(i) catalyst [Mn(PNPNH-iPr)(H)(CO)2] showed higher stability and activity than its Fe(ii) analogue. TONs up to 10 000 and quantitative yields were obtained after 24 h using DBU as the base at 80 °C and 80 bar total pressure. At catalyst loadings as low as 0.002 mol%, TONs greater than 30 000 could be achieved in the presence of LiOTf as the co-catalyst, which are among the highest activities reported for base-metal catalysed CO2 hydrogenations to date.
137 citations
Authors
Showing all 10288 results
Name | H-index | Papers | Citations |
---|---|---|---|
Joao Seixas | 153 | 1538 | 115070 |
A. Gomes | 150 | 1862 | 113951 |
Amartya Sen | 149 | 689 | 141907 |
António Amorim | 136 | 1477 | 96519 |
Joao Varela | 133 | 1411 | 92438 |
Pietro Faccioli | 132 | 1378 | 89795 |
João Carvalho | 126 | 1278 | 77017 |
Pedro Jorge | 124 | 776 | 68658 |
Pedro Silva | 124 | 961 | 74015 |
A. De Angelis | 118 | 534 | 54469 |
Hermine Katharina Wöhri | 116 | 629 | 55540 |
Helena Santos | 114 | 1058 | 54286 |
P. Conde Muiño | 109 | 558 | 56133 |
Joao Saraiva | 107 | 519 | 53340 |
J. N. Reddy | 106 | 926 | 66940 |