THE SOUTHERN AFRICAN REGIONAL FORMATION: A GEOGRAPHICAL PERSPECTIVE

Abstract. Isoprene, the most abundant non-methane volatile organic compound (VOC) emitted into the atmosphere, is known to undergo gas phase oxidation to form eight different hydroxynitrate isomers in "high NOx" environments. These hydroxynitrates are known to affect the global and regional formation of ozone and secondary organic aerosol (SOA), as well as affect the distribution of nitrogen. In the present study, we have synthesized three of the eight possible hydroxynitrates: 4-hydroxy-3-nitroxy isoprene (4,3-HNI) and E/Z-1-hydroxy-4-nitroxy isoprene (1,4-HNI). Oxidation of the 4,3-HNI isomer by the OH radical was monitored using a flow tube chemical ionization mass spectrometer (FT-CIMS), and its OH rate constant was determined to be (3.64 ± 0.41) × 10−11 cm3 molecule−1 s−1. The products of 4,3-HNI oxidation were monitored, and a mechanism to explain the products was developed. An isoprene epoxide (IEPOX) – a species important in SOA chemistry and thought to originate only from "low NOx" isoprene oxidation – was found as a minor, but significant product. Additionally, hydrolysis kinetics of the three synthesized isomers were monitored with NMR. The bulk, neutral solution hydrolysis rate constants for 4,3-HNI and the 1,4-HNI isomers were (1.59±0.03 × 10−5 s−1 and (6.76 ± 0.09) × 10−3 s−1, respectively. The hydrolysis reactions of each isomer were found to be general acid-catalyzed. The reaction pathways, product yields and atmospheric implications for both the gas phase and aerosol-phase reactions are discussed.

Download Full-text

A República e a Monarquia em confronto: a Guerra Civil portuguesa na raia galega (1911- 1912) = The Republic and the Monarchy in confrontation: the Portuguese Civil War on the Galician border (1911-1912)

REVISTA DE HISTORIOGRAFÍA (RevHisto) ◽

10.20318/revhisto.2019.4745 ◽

2019 ◽

Vol 30 ◽

pp. 97

Author(s):

Luís Miguel Moreira

Keyword(s):

Civil War ◽

The South ◽

The North ◽

Geographical Perspective ◽

The Republic ◽

Sobre Todo

Resumen: La progresiva radicalización ideológica del régimen republicano, instaurado en Portugal en octubre de 1910, provocó una oposición conservadora y monárquica que se organizó en el exilio, sobre todo en el sur de Galicia. Entre octubre de 1911 y junio de 1912, estacionados en varios pueblos y villas gallegas en la raya con Portugal, los monárquicos hicieron dos incursiones en territorio portugués —el primero en Vinhais y el segundo en Chaves— con el fin de fomentar la rebelión contra régimen instaurado. Sin embargo, las tropas republicanas, más numerosas y mejor equipadas, vencieron todos los combates. En la época, este episodio de guerra civil mereció amplia cobertura periodística, particularmente por la prensa afecta al régimen republicano. Los mapas y las fotografías de la frontera fueron ampliamente utilizados para localizar e ilustrar los acontecimientos. En este texto, pretendemos reconstituir estos movimientos, proponiendo una lectura geográfico-histórica de la raya luso-gallega, en el contexto de este episodio.Palabras clave: República portuguesa, incursiones monárquicas, raya galaico-portuguesa, cartografía propaganda.Abstract: The ideological radicalisation of the republican regime, established in Portugal in October 1910, gave rise to the forming of a conservative and monarchical opposition in exile, in the south of the Spanish historic region of Galicia. Between October 1911 and June 1912, from several Galician villages not far from the Portuguese border, the monarchists made two incursions into the north of the country - the first to Vinhais and the second to Chaves - with the aim of fuelling popular uprisings and a military rebellion against the new regime. However, the Republican troops, more numerous and better equipped, won all the battles. At the time, this episode of civil war received extensive journalistic coverage particularly from the newspapers close to the republican regime. Maps and photographs of the border were widely used to locate and illustrate the events. From the historic-geographical perspective of the Portuguese-Galician border, this paper reconstitutes these movements in the broader historical context.Key words: Portuguese Republic, monarchical incursions, Portuguese-Galician border, propaganda maps.

Download Full-text