Systematic Variation In Number Research Articles

Regulation from above or below: Port greening measures in the European Union and the United States

AbstractFocusing on 23 greening measures, this paper systematically compares the greening efforts of the busiest container and cargo ports in the United States (US) and the European Union (EU). We move beyond accounts for general environmental differences between the EU and the US to examine how specific environmental decisions are shaped by the effects of regulatory characteristics in each region. We identify systematic variation in number and type of port greening measures adopted in the two regions. We demonstrate that differences in the number and type of measures adopted reflect the level of policy making with local policy making playing a more important role in the US compared to the EU, thus proposing a pathway through which the form of regulatory approach could influence content and extent of regulation. The EU adopts regulation that is broader in scope while US ports are more likely to address problems affecting local populations.

Gold nanoparticles adsorption study onto periodic block copolymer using quartz crystal microbalance

In this work, we have studied adsorption and aggregation characteristics of citrate stabilized gold nanoparticles (AuNPs) onto periodic block copolymer using a quartz crystal microbalance (QCM) technique. Thin film of polystyrene block-poly (2-vinylpyridine) (PS-b-P2VP) template was coated onto gold Q-sense sensor crystals to study the adsorption and aggregation characteristics of AuNPs. The template pattern was controlled through an oxygen plasma reactive ion etching (RIE) process. Height of the template was varied from 50nm to 20nm with the inter-particle separation of ~200nm. Adsorption studies of AuNPs were carried out in-situ and in real time by means of the QCM technique. There is change in frequency of the Q-sense sensor crystal with the variation in mass/volume of pattern polymer template. The adsorption and aggregation characteristics of AuNPs onto a pattern template substrate were studied using AFM and QCM analysis. The arrays of gold nanoparticle clusters presenting a systematic variation in number of AuNPs due to different template dimensions show a mean intra-particle separation below 10nm.