Landscape evolution of the Apurimac river drainage basin, southern Peru

The northernmost part of the Altiplano in Southern Peru is drained by the river Apurimac and its tributaries. The Altiplano is a region that covers most of the eastern part of the Cordillera Occidental and is bounded in the East by the Cordillera Oriental. The Apurirnac River Drainage Basin (ARDB) extends roughly between 13 °S and l5°S over 50000 km 2. It mainly occupies the northeastern flank of the Cordillera Occidental and a negligible part of the southwestern flank of the Cordillera Oriental. At the latitude of the Abancay deflection, i.e. 13.5 S; 72.7 W, the Apurirnac River abandons the Cordillera Occidental. On its way to the Amazon Basin in the North the Apurimac River drains the Cordillera Oriental and the Sub-Andean Zone (SAZ). The incision by the rivers of the ARDB has created differences in relief of more than 2000 m that contributed to the denudation and exhumation, hence the evolution ofthe landscape. The Altiplano sedimentary basin contains an 8 kilometers thick succession of Cenozoic sediments, which it received from the surrounding highs in the West and the Easl Its structural framework has been formed by the various tectonic events that struck the Andes and the various pulses of magmatic activity that took place during the Cenozoic. In the western part of the Altiplano Miocene volcanics domínate, whereas in the northeastern part, in the Cusco region, clastic deposits do so. In the region of Abancay, a batholite got emplaced during the mid Tertiary, that extends over few 1000 km2

Sustainable design of biorefinery processes: existing practices and new methodology

Nowadays, eco-designing products is increasingly practiced. The next challenge for sustain- ability is to optimize production processes. Biorefi neries are particularly concerned with this improve- ment, because they use renewable resources. To identify the contribution of transformation processes to the overall environmental impacts, Life Cycle Assessment (LCA) appears as the adequate method. A literature review highlights that LCA is mainly performed on biorefi neries to compare biomass feed- stocks between them and to a fossil reference. Another part of environmental LCA compares the impacts of different processing routes. Nevertheless, these evaluations concern already designed pro- cesses. Generally, processes are considered as a unique operation in assessments. However, some criteria like operating can notably modify environmental burdens. The eco-design of biorefi nery pro- cesses can be guided by coupling process simulation to LCA. This method has been emerging in the chemical sector in recent years. Consequently, this paper proposes a new methodological approach to assessing the complete sustainability of biorefi nery processes, since its fi rst design stages. In addi- tion to coupling process simulation and environmental LCA, the other pillars of sustainability will be assessed. Indeed, Life Cycle Costing and Social Life Cycle Assessment can be performed to obtain an integrated methodological framework. The simultaneous optimization of the environmental, economic, and social performances of the process can lead to antagonist ways of improving. Consequently, compromises should be realized. Thereby, the multi-objective optimization can be accomplished by a metaheuristic method supported by a decision-making tool. Finally, the main limits of this method and some perspectives and ways for improving are discussed

The development of a gaschromatographic method for the analysis of isosorbide dinitrate, isosorbide-2-mononitrate and isosorbide-5-mononitrate

In dit rapport wordt de ontwikkeling van een gaschromatografische bepalingsmethode voor isosorbidedinitraat en zijn metabolieten isosorbide-2-mononitraat en isosorbide-5-mononitraat beschreven. Besproken wordt hoe tot een bepaalde werkwijze voor de extractie en de gaschromatografische omstandigheden werd gekomen. De uiteindelijk vastgestelde methode wordt uitgebreid beschreven. Vervolgens wordt de validering van de methode beschreven. De hieruit berekende statistische gegevens worden besproken. De terugwinning varieert tussen gemiddeld 80 en 114%. De variatiecoefficient bedragt 2.3 -3.6% voor het hoogste concentratieniveau, 2.1 - 4.7% voor het middenniveau van 7.9 - 9.2% voor het laagste niveau. De beschreven methode is bruikbaar voor onderzoek naar de plasmaspiegels van organische nitraten bij farmacologisch en farmacokinetisch onderzoek bij ratten.Abstract not availableCB

The determination of 2-nitropropane in ratplasma with high pressure liquid chromatography

In het kader van een biobeschikbaarheidsonderzoek van 2-nitropropaan in de rat werd een hogedrukvloeistofchromatografische methode ontwikkeld om deze stof in plasma te kunnen bepalen. Bij de voorbewerking van het plasma is het onteiwitten een kritisch onderdeel in de procedure. In de beschreven methode wordt hiervoor acetonitril gebruikt ; het is gebleken dat druppelsgewijs toevoegen met een doseerpompje de beste resultaten oplevert. Een golflengte van 224 nm voldoet goed bij een eluens dat uit acetonitril en tris(hydroxymethyl)-amino-methaan (TRIS)-buffer bestaat. De laagste meetbare concentratie van 2-nitro- propaan in plasma is bij deze golflengte 60 mug/ml. Over een meetgebied van 0.06 tot 15 mug/ml is de respons lineair. Bij reproduceerbaarheidsmetingen met monsters waarvan de concentraties 0.6 ; 3.0 of 15.0 mug/ml bedroegen varieerden de variatiecoefficienten biannen analysedagen van respectievelijk 15.8 - 30.0, 3.1 - 3.9 en 1.1 - 2.0%. Er treden soms onverwachte storende pieken op ; door de pH van het eluens te veranderen kan hierin verbetering worden gebracht.Abstract not availableRIV