Direct radiative effect of aerosols emitted by transport from road, shipping and aviation

Aerosols and their precursors are emitted abundantly by transport activities. Transportation constitutes one of the fastest growing activities and its growth is predicted to increase significantly in the future. Previous studies have estimated the aerosol direct radiative forcing from one transport sub-sector, but only one study to our knowledge estimated the range of radiative forcing from the main aerosol components (sulphate, black carbon (BC) and organic carbon) for the whole transportation sector. In this study, we compare results from two different chemical transport models and three radiation codes under different hypothesis of mixing: internal and external mixing using emission inventories for the year 2000. The main results from this study consist of a positive direct radiative forcing for aerosols emitted by road traffic of +20±11 mW m−2 for an externally mixed aerosol, and of +32±13 mW m−2 when BC is internally mixed. These direct radiative forcings are much higher than the previously published estimate of +3±11 mW m−2. For transport activities from shipping, the net direct aerosol radiative forcing is negative. This forcing is dominated by the contribution of the sulphate. For both an external and an internal mixture, the radiative forcing from shipping is estimated at −26±4 mW m−2. These estimates are in very good agreement with the range of a previously published one (from −46 to −13 mW m−2) but with a much narrower range. By contrast, the direct aerosol forcing from aviation is estimated to be small, and in the range −0.9 to +0.3 mW m−2.

Dendrimers: a new class of nanoscopic containers and delivery devices

Dendrimers and hyperbranched polymers are a relatively new class of materials with unique molecular architectures and dimensions in comparison to traditional linear polymers. This review details recent notable advances in the application of these new polymers in terms of the development of new polymeric delivery systems. Although comparatively young, the developing field of hyperbranched drug delivery devices is a rapidly maturing area and the key discoveries in drug-conjugate systems amongst others are highlighted. As a consequence of their ideal hyperbranched architectures, the utilisation of host-guest chemistries in dendrimers has been included within the scope of this review. (C) 2003 Elsevier Ltd. All rights reserved.

Water-soluble, unimolecular containers based on amphiphilic multiarm star block copolymers

A new class of water-soluble, amphiphilic star block copolymers with a large number of arms was prepared by sequential atom transfer radical polymerization (ATRP) of n-butyl methacrylate (BMA) and poly( ethylene glycol) methyl ether methacrylate (PEGMA). As the macroinitiator for the ATRP, a 2-bromoisobutyric acid functionalized fourth-generation hyperbranched polyester (Boltorn H40) was used, which allowed the preparation of star polymers that contained on average 20 diblock copolymer arms. The synthetic concept was validated by AFM experiments, which allowed direct visualization of single molecules of the multiarm star block copolymers. DSC and SAXS experiments on bulk samples suggested a microphase-separated structure, in agreement with the core-shell architecture of the polymers. SAXS experiments on aqueous solutions indicated that the star block copolymers can be regarded as unimolecular micelles composed of a PBMA core and a diffuse PPEGMA corona. The ability of the polymers to encapsulate and release hydrophobic guests was evaluated using H-1 NMR spectroscopy. In dilute aqueous solution, these polymers act as unimolecular containers that can be loaded with up to 27 wt % hydrophobic guest molecules.

Climate model calculations of the impact of aerosols from road transport and shipping

Road transport and shipping are copious sources of aerosols, which exert a 9 significant radiative forcing, compared to, for example, the CO2 emitted by these sectors. An 10 advanced atmospheric general circulation model, coupled to a mixed-layer ocean, is used to 11 calculate the climate response to the direct radiative forcing from such aerosols. The cases 12 considered include imposed distributions of black carbon and sulphate aerosols from road 13 transport, and sulphate aerosols from shipping; these are compared to the climate response 14 due to CO2 increases. The difficulties in calculating the climate response due to small 15 forcings are discussed, as the actual forcings have to be scaled by large amounts to enable a 16 climate response to be easily detected. Despite the much greater geographical inhomogeneity 17 in the sulphate forcing, the patterns of zonal and annual-mean surface temperature response 18 (although opposite in sign) closely resembles that resulting from homogeneous changes in 19 CO2. The surface temperature response to black carbon aerosols from road transport is shown 20 to be notably non-linear in scaling applied, probably due to the semi-direct response of clouds 21 to these aerosols. For the aerosol forcings considered here, the most widespread method of 22 calculating radiative forcing significantly overestimates their effect, relative to CO2, 23 compared to surface temperature changes calculated using the climate model.

Transport impacts on atmosphere and climate: shipping

Emissions of exhaust gases and particles from oceangoing ships are a significant and growing contributor to the total emissions from the transportation sector. We present an assessment of the contribution of gaseous and particulate emissions from oceangoing shipping to anthropogenic emissions and air quality. We also assess the degradation in human health and climate change created by these emissions. Regulating ship emissions requires comprehensive knowledge of current fuel consumption and emissions, understanding of their impact on atmospheric composition and climate, and projections of potential future evolutions and mitigation options. Nearly 70% of ship emissions occur within 400 km of coastlines, causing air quality problems through the formation of ground-level ozone, sulphur emissions and particulate matter in coastal areas and harbours with heavy traffic. Furthermore, ozone and aerosol precursor emissions as well as their derivative species from ships may be transported in the atmosphere over several hundreds of kilometres, and thus contribute to air quality problems further inland, even though they are emitted at sea. In addition, ship emissions impact climate. Recent studies indicate that the cooling due to altered clouds far outweighs the warming effects from greenhouse gases such as carbon dioxide (CO2) or ozone from shipping, overall causing a negative present-day radiative forcing (RF). Current efforts to reduce sulphur and other pollutants from shipping may modify this. However, given the short residence time of sulphate compared to CO2, the climate response from sulphate is of the order decades while that of CO2 is centuries. The climatic trade-off between positive and negative radiative forcing is still a topic of scientific research, but from what is currently known, a simple cancellation of global mean forcing components is potentially inappropriate and a more comprehensive assessment metric is required. The CO2 equivalent emissions using the global temperature change potential (GTP) metric indicate that after 50 years the net global mean effect of current emissions is close to zero through cancellation of warming by CO2 and cooling by sulphate and nitrogen oxides.

Liquidity effects and FFA returns in the international shipping derivatives market

The study examines the impact of liquidity risk on freight derivatives returns. The Amihud liquidity ratio and bid–ask spreads are utilized to assess the existence of liquidity risk in the freight derivatives market. Other macroeconomic variables are used to control for market risk. Results indicate that liquidity risk is priced and both liquidity measures have a significant role in determining freight derivatives returns. Consistent with expectations, both liquidity measures are found to have positive and significant effects on the returns of freight derivatives. The results have important implications for modeling freight derivatives, and consequently, for trading and risk management purposes.

Marknadsundersökning angående design för behållare av ansiktscreme : Marketing reseach concerning the design of beauty cream containers

Detta examensarbete innefattar en teoretisk och en praktisk del om marknadsundersökningar. Inom teoridelen har litteratur inom ämnet studerats för att sedan genomföra en marknadsundersökning. Utöver detta ha resultatet som erhållts ur marknadsundersökningen tillämpats för att ta fram ett designkoncept för en serie ansiktscremer.Marknadsundersökningen utfördes i form av en observationsresearch där ansiktscremer av olika priser och märken jämfördes, samt en webbenkät där målgruppen fick svara på frågor om ansiktscremers behållare och behållarens färg. Målgruppen är satt till män och kvinnor över 15 år som använder ansiktscreme. För att marknadsundersökningen ska vara möjlig att genomföra inom satta tidsramar skickades webbenkäten endast ut till studenter vid Högskolan Dalarna i Borlänge samt till läsare av modebloggen ”Hopplösa Modenördar”.Totalt inkom 469 svar.Resultatet visade att vitt, silver och svart är de färger som tilltalar män mest i fråga om ansiktscremebehållare. För kvinnor var det vitt, guld och rosa som kändes mest tilltalande. Ur resultatet kunde även utläsas att burken var den behållare som tilltalar både män och kvinnor mest.

Greek shipping and the crisis of the 1980's

In 1982, Greek shipping plunged into a severe crisis: the size of the fleet declined dramatically and over 30% of the fleet was laid-up. catapulting many shipping companies into bankruptcy. The causes of the crisis were: The world recession, leading to regulation, protectionism, subsidization. and the growth of new competition in the tramp shipping market. The erosion of the cost differential between Greek shipping and other maritime nations of the world. The specialization and containerization of the world fleet. The old age and other characteristics of the Greek fleet, which exacerbated the crisis. Greek shipping, with its long history and the expertise, diligence, and supreme opportunism of its dynamic shipowners, will survive the crisis.

Evaluation of alternative containers to determining the working width of fertilizer spreaders

Os ensaios de largura de trabalho e uniformidade de distribuição são de difícil execução para o agricultor por exigirem equipamentos, recursos e métodos complexos. Portanto, este trabalho teve como objetivo avaliar coletores alternativos para tornar mais acessível a regulagem e a avaliação de distribuidores de fertilizantes sólidos a lanço. Foram utilizados quatro diferentes conjuntos de coletores: i) coletores construídos segundo a norma ISO 5690/1; ii) coletores de polietileno (bandejas plásticas) com tela de sombreamento para evitar o ricochete de material; iii) coletores formados por caixas de leite longa vida, e iv) coletores formados por vasos de polietileno (número 3,5). Também foram utilizados três diferentes distribuidores para as avaliações. Os coletores alternativos apresentaram maior retenção de partículas que os coletores normatizados. A largura efetiva de trabalho obtida para os coeficientes de variação de 12,5; 15; 17,5 e 20% variou entre os coletores nos diferentes percursos. O coletor que mais se assemelhou à norma foram os vasos de polietileno. Constatou-se que a altura dos coletores foi mais importante para sua eficiência do que a sua área de coleta.

PET containers in Brazil: Opportunities and challenges of a logistics model for post-consumer waste recycling

The use of post-consumer materials is directly related to reducing the cost of production and extraction of natural resources. Non-recyclable materials are randomly disposed in the environment. Brazil is one of the largest consumers of PET (polyethylene terephthalate) bottles. The purpose of this paper is to describe the opportunities and challenges of the logistics model for post-consumer PET bottle recycling in Brazil, while providing knowledge of its practices along the recycling chain. The results describe the need to educate those directly and indirectly involved in the process: to reduce consumption in order to reduce the amount of waste generated: to structure the post-consumer reverse chain and engage industrial sectors and government, through public policies, to support cleaner technologies along the PET bottle production chain. (C) 2010 Elsevier B.V. All rights reserved.

Trade between Caribbean Community (CARICOM) and Central American Common Market (CACM) countries: the role to play for ports and shipping services

Includes bibliography

Caribbean shipping sector: a planning and policy perspective

Includes bibliography