Electronic Structure of Heterocyclic Ring Chain Polymers

The band gaps, ionization potentials and electron affinities of conjugated chain polymers comprising heterocyclic aromatic rings are studied systematically as a function of atomic substitutions with N, O and S using first principles density functional calculations

The impact of weather variability and climate change on pesticide applications in the US - An empirical investigation

Weather variability and climate change affect the application of pesticides in agriculture, in turn impacting the environment. Using panel data regression for the US, we find that weather and climate differences significantly influence the application rates of most pesticides. Subsequently, the regression results are linked to downscaled climate change scenario the Canadian and Hadley climate change models. We find that the application of most pesticides increase under both scenarios. The projection results vary by crop, region, and pesticide.Climate change, weather variability, pesticide, regression, panel data, North America, US

Large Horizontal Displacements of Houses in Rotterdam

In 1983 it was established that six blocks of terrace houses in Rotterdam had undergone large horizontal displacements. These displacements were caused by insufficient stability of the adjacent quay and as a result one of the blocks had moved as much as 2.5 m since 1958. The foundation piles of the houses were not designed to resist any horizontal loading. As a result of these large horizontal movements the piles had deflected to such an extent that complete failure was feared. This paper describes the remedial measures that were taken to improve the stability of the quay and foundations of the houses. The present displacement behaviour is compared with the horizontal displacement predicted from creep analysis

PROGRESS IN ESTIMATING THE MARGINAL COSTS OF GREENHOUSE GAS EMISSIONS

The unjust distributional consequences of climate change, and its potentially negative aggregate effect on economic growth and welfare are two reasons to be concerned about climate change. Our knowledge of the impact of climate change is incomplete. Monetary valuation is difficult and controversial. The effect of other developments on the impacts of climate change is largely speculative. Nonetheless, it can be shown that poorer countries and people are more vulnerable than are richer countries and people. A modest global warming is likely to have a net negative effect on poor economics in hot climates, but may have a positive effect on rich economies in temperate climates. If one counts dollars, the world aggregate impact may be positive. If one counts people, the world aggregate effect is probably negative. For more substantial warming, negative effects become more negative, and positive effects turn negative. The marginal costs of carbon dioxide emissions are uncertain and sensitive to assumptions that partially reflect ethical and methodological positions, but are unlikely to exceed $50 per tonne of carbon. The marginal costs of methane emission are likely to be less than$250/tCH4; the marginal costs of nitrous oxide emissions are probably lower than $7000/tN2O. Global warming potentials, the official manner to trade-off the various greenhouse gases, do not reflect, conceptually or numerically, the real tradeoffs in either a cost-benefit or a cost-effectiveness framework.Impacts of climate change, economic valuation, equity, marginal costs

Submicron active-passive integration for InP-based membranes on silicon

The high vertical index contrast and the small thickness of thin InP-based membrane structures bonded with BCB on Silicon allow the realization of very small devices. To make photonic integrated circuits with both passive and active components in these membranes, active-passive integration on a small scale is essential. In this paper we will present our results on sub-micrometer active areas for membrane applications

Terra sigillata in southern Latium:The evidence from the Pontine Region Project (1987-2014)

This contribution is the first of a series of publications by the authors to systematically disclose the wealth of material evidence collected during some 30 years of fieldwork in the Pontine region by the Pontine Region Project. This project has, since its inception in the mid-1980s, investigated more than 36 km2 of terrain across all major geomorphological units of the region, largely by means of systematic surface investigations. During these investigations, close to 200 000 artefacts were collected for further study, including c. 1 660 fragments of (Italian) terra sigillata, the emblematic, shiny red fine table ware of the Early Imperial period. In this article, we present a detailed spatial and contextual analysis of the terra sigillata fragments that have been gathered within the Pontine Region Project and discuss the results in light of economic issues (market integration, economic growth). We then supplement this evidence by published evidence of name stamps from surrounding areas to further expose to what extent, and in what ways, the different parts of southern Latium were embedded in the long-distance economic networks of the period

Monitoring stroomgebieden : een tussenrapport : meerjaren monitoringsprogramma naar de uit- en afspoeling van nutriënten vanuit landbouwgronden in stroomgebieden en polders

In vier onderzoeksgebieden is alle bestaande kennis van het oppervlaktewatersysteem en de waterkwaliteit verzameld. Het betreft: de Drentse Aa, een zandgebied met lage nutriëntenbelasting; de Schuitenbeek, een zandgebied met hoge nutriëntenbelasting; de Krimpenerwaard, een veenpolder; Quarles van Ufford, een bemalen rivierkleigebied. Vervolgens zijn waar nodig extra veldmetingen gedaan. Deze aanvullende metingen hebben kennishiaten binnen de gebieden opgevuld en zijn ingezet voor de bouw van een model dat de relaties tussen alle onderdelen in het oppervlaktewatersysteem betrouwbaar en gedetailleerd weergeeft. Dat model is gebouwd als afgeleide van een bestaand, landelijk model (STONE), dat in fases is verfijnd en uitgebreid op basis van steeds gedetailleerdere systeemkennis en gebiedsdata. Aanpassingen in het model zijn steeds getoetst aan meetgegevens uit het gebied, waarmee direct duidelijk werd of de aanpassing resulteerde in een beter werkend model