Global Warming and Changing Temperature Patterns over Mauritius

This paper discusses the changing temperature pattern over Mauritius. We observe an increase of the annual mean temperature at Pamplemousses since 1876 with an average rate of 0.009oC per year with a significant correlation coefficient of 0.67. Compared to the mean temperature for the period of 1951 to 1960, we find that there is a shift in time (decadal) in the warming from northwest to other regions over the island. The temperature deviations are more marked in winter than in summer. Moreover, the number of hot days per year is increasing and the number of cold days is decreasing.Keywords: Temperature spatial variation, trend, hot and cold days, kriggin

A Water Accumulation Flooding Potentiality Index (WAFPI) for rating the risk of flooding– A case study of Mauritius Island

The Water Accumulation Flooding Potentiality Index (WAFPI) is a qualitative risk assessment method based on a factorial scoring system that is aimed at dividing the land into classes that are similar in their susceptibility to flooding due to accumulating water. Such an assessment precedes quantitative flood modeling work, the overall results that are used for planning flood mitigation measures. WAFPI takes the form of an equation with five parameters as input, namely, rainfall amount; topographic slope angle; permeability of geology strata; soil infiltration capacity & land cover imperviousness. The output is a map with indices ranging from 1 to 10, with 1 being the lowest risk and 10 the highest risk of flooding. The assessment has been carried for Mauritius for the rainiest month of February. Results show that the assessment method succeeds in qualitatively evaluating the geospatial potentiality and the geospatial distribution of flooding due to water accumulation.Keywords: flooding, risk assessment, potentiality mapping, GIS, factorial scoring, Mauritius

EFFECTS OF ORDER AND DISORDER ON FIELD-EFFECT MOBILITIES MEASURED ON CONJUGATED POLYMER THIN-FILM TRANSISTORS

The morphology of conjugated polymer thin films has been controlled by exploiting the processes giving rise to solvatochromism in the initial polymer solutions from which the polymer films were deposited by spin coating. The material used was the substituted polythiophene, 3[2(S2-methylbutoxy)ethyl]-polythiophene. Starting with polymer dissolved in ''good'' solvent, various quantities of ''bad'' solvent when added lead to the reorganization of the solubilizing side chains attached to the conjugated polymer backbone. Ordering of these side chains increases with addition of bad solvent decreasing the flexibility of the backbone, yielding more rigid rodlike polymer chains. This in turn causes aggregation and finally precipitation. It is found that this molecular order can be transferred from solution to solid film during the spinning process, ascertained from optical spectroscopy. With these films acting as the active layer in a field-effect transistor structure, the mobility of the carriers injected into the films can be measured. It is found that as the molecular order and aggregation increases, carrier mobility decreases from approximately 10(-5) cm-2 V-1 S-1 to less-than-or-equal-to 10(-8) cm2 V-1 s-1 in films displaying the highest degree of molecular order. This is ascribed to the increased interchain separation in the ordered systems along with effects due to macroscopic aggregate grain boundaries

Bathochromic shift in absorption spectra of conjugated polymer nanoparticles with displacement along backbones

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