Chapter 12. PORTUGAL: Tackling a Complex Chemical Equation: The Portuguese Society of Chemistry, 1911–1926

2008 ◽  
pp. 257-280
Author(s):  
Vanda Leitão ◽  
Ana Carneiro ◽  
Ana Simões
2018 ◽  
Vol 12 (2) ◽  
pp. 1-7
Author(s):  
Sînziana Venera Morărița

Abstract Although relatively recent, peach culture has grown great in our country due to the special quality of the fruit, its very complex chemical composition and the large production that can be obtained without much effort. Peach is a species slightly adapted to our climatic conditions, suffers from winter frost, but can provide productive and long productions of 10-15 years.


1991 ◽  
Vol 56 (10) ◽  
pp. 2107-2141 ◽  
Author(s):  
Mirko Dohnal

Qualitative model is a theoretical background of commonsense. Complex qualitative models can have prohibitively many solutions (qualitative states). Therefore a qualitative analogy of such classical quantitative tools as e.g. the decomposition is developed. Practical applications of decomposition principle is nearly always ad hoc. Therefore two case studies are presented in details, a chemical process (mixer, chemical reactor, separator) and an anaerobic fermentor.


Author(s):  
Peter Linehan

This book springs from its author’s continuing interest in the history of Spain and Portugal—on this occasion in the first half of the fourteenth century between the recovery of each kingdom from widespread anarchy and civil war and the onset of the Black Death. Focussing on ecclesiastical aspects of the period in that region (Galicia in particular) and secular attitudes to the privatization of the Church, it raises inter alios the question why developments there did not lead to a permanent sundering of the relationship with Rome (or Avignon) two centuries ahead of that outcome elsewhere in the West. In addressing such issues, as well as of neglected material in Spanish and Portuguese archives, use is made of the also unpublished so-called ‘secret’ registers of the popes of the period. The issues it raises concern not only Spanish and Portuguese society in general but also the developing relationship further afield of the components of the eternal quadrilateral (pope, king, episcopate, and secular nobility) in late medieval Europe, as well as of the activity in that period of those caterpillars of the commonwealth, the secular-minded sapientes. In this context, attention is given to the hitherto neglected attempt of Afonso IV of Portugal to appropriate the privileges of the primatial church of his kingdom and to advance the glorification of his Castilian son-in-law, Alfonso XI, as God’s vicegerent in his.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2131
Author(s):  
Leonardo Dalseno Antonino ◽  
Júlia Rocha Gouveia ◽  
Rogério Ramos de Sousa Júnior ◽  
Guilherme Elias Saltarelli Garcia ◽  
Luara Carneiro Gobbo ◽  
...  

Several efforts have been dedicated to the development of lignin-based polyurethanes (PU) in recent years. The low and heterogeneous reactivity of lignin hydroxyl groups towards diisocyanates, arising from their highly complex chemical structure, limits the application of this biopolymer in PU synthesis. Besides the well-known differences in the reactivity of aliphatic and aromatic hydroxyl groups, experimental work in which the reactivity of both types of hydroxyl, especially the aromatic ones present in syringyl (S-unit), guaiacyl (G-unit), and p-hydroxyphenyl (H-unit) building units are considered and compared, is still lacking in the literature. In this work, the hydroxyl reactivity of two kraft lignin grades towards 4,4′-diphenylmethane diisocyanate (MDI) was investigated. 31P NMR allowed the monitoring of the reactivity of each hydroxyl group in the lignin structure. FTIR spectra revealed the evolution of peaks related to hydroxyl consumption and urethane formation. These results might support new PU developments, including the use of unmodified lignin and the synthesis of MDI-functionalized biopolymers or prepolymers.


RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20216-20231
Author(s):  
Ayelén F. Crespi ◽  
Verónica M. Sánchez ◽  
Daniel Vega ◽  
Ana L. Pérez ◽  
Carlos D. Brondino ◽  
...  

The complex chemical functionalization of the aldehyde group was elucidated in copper and cobalt complexes for 4- and 3-pyridinecarboxaldehyde ligands.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2914
Author(s):  
Kevin J. H. Lim ◽  
Yan Ping Lim ◽  
Yossa D. Hartono ◽  
Maybelle K. Go ◽  
Hao Fan ◽  
...  

Natural products make up a large proportion of medicine available today. Cannabinoids from the plant Cannabis sativa is one unique class of meroterpenoids that have shown a wide range of bioactivities and recently seen significant developments in their status as therapeutic agents for various indications. Their complex chemical structures make it difficult to chemically synthesize them in efficient yields. Synthetic biology has presented a solution to this through metabolic engineering in heterologous hosts. Through genetic manipulation, rare phytocannabinoids that are produced in low yields in the plant can now be synthesized in larger quantities for therapeutic and commercial use. Additionally, an exciting avenue of exploring new chemical spaces is made available as novel derivatized compounds can be produced and investigated for their bioactivities. In this review, we summarized the biosynthetic pathways of phytocannabinoids and synthetic biology efforts in producing them in heterologous hosts. Detailed mechanistic insights are discussed in each part of the pathway in order to explore strategies for creating novel cannabinoids. Lastly, we discussed studies conducted on biological targets such as CB1, CB2 and orphan receptors along with their affinities to these cannabinoid ligands with a view to inform upstream diversification efforts.


2020 ◽  
Vol 55 (1) ◽  
pp. 807-807 ◽  
Author(s):  
Ahmed Tlili ◽  
Natàlia Corcoll ◽  
Åsa Arrhenius ◽  
Thomas Backhaus ◽  
Juliane Hollender ◽  
...  

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