Spatial variation of roadside C2–C6 hydrocarbon concentrations during low wind speeds: Validation of CALINE4 and COPERT III modelling

The CALINE4 model is widely used to predict the effect of vehicle emissions on ambient concentrations close to roadways. It requires an evaluation of the rate at which different air pollutants are emitted by vehicles, taking into account things such as vehicle flow, velocity, type and age. For Europe the databases of the COmputer Program to calculate Emissions from Road Transport (COPERT) are combined with local vehicle details to obtain site-specific emission factors for dispersion modelling. The ability of CALINE4 to predict the spatial variation of hydrocarbon concentrations downwind of a motorway is assessed, as is the accuracy of COPERT III composite emission factors for several hydrocarbon compounds. The concentrations of seven traffic-associated compounds is found at three locations downwind and upwind of a motorway. Modelled and measured background-corrected downwind concentrations are compared on three bases: daily peak hour concentrations, mean concentrations, and a set of model evaluation parameters.     

Spatial variation of roadside C2–C6 hydrocarbon concentrations during low wind speeds: A note

This Note describes an investigation of spatial variations in the ambient concentrations of hydrocarbons in the vicinity of a suburban motorway during five consecutive weekday morning peak periods of unusually warm and calm conditions. Background-corrected downwind concentrations representing the influence of the motorway source were found to be strongly dependant on wind speed and direction. The ambient ethene-to-acetylene concentration ratio was greatest close to the roadside and the effect of wind speed on the ratio had different average profiles for main wind directions due to different rates of dispersal. Higher values were obtained using background-corrected concentrations.     

WTO与交通企业发展

刘光溪:入世谈判过程本身具有重大意义 入世谈判的过程对于中国经济的发展、中国经济体制改革的深化是一个巨大的教育过程.这次谈判不光是经济和贸易的交锋,还是两种文化、两种理念的碰撞,对中华民族价值取向、理性思维将产生深远的影响.     

Science Needs for Sea-Level Adaptation Planning: Comparisons among Three U.S. Atlantic Coastal Regions

To identify priority information needs for sea-level rise planning, we conducted workshops in Florida, North Carolina, and Massachusetts in the summer of 2012. Attendees represented professionals from five stakeholder groups: federal and state governments, local governments, universities, businesses, and nongovernmental organizations. Over 100 people attended and 96 participated in breakout groups. Text analysis was used to organize and extract most frequently occurring content from 16 total breakout groups. The most frequent key words/phrases were identified among priority topics within five themes: analytic tools, communications, land use, ecosystem management, and economics. Diverse technical and communication tools were identified to help effectively plan for change. In many communities, planning has not formally begun. Attendees sought advanced prediction tools yet simple messaging for decision-makers facing politically challenging planning questions. High frequency key words/phrases involved fine spatial scales and temporal scales of less than 50 years. Many needs involved communications and the phrase “simple messaging” appeared with the highest frequency. There was some evidence of geographic variation among regions. North Carolina breakout groups had a higher frequency of key words/phrases involving land use. The results reflect challenges and tractable opportunities for planning beyond current, geophysically brief, time scales (e.g., election cycles and mortgage periods).     

MMAS in Fiji

This article is part of a special issue that provides insight into global conservation science by analyzing a 5-year, $12.5 million global marine conservation science and policy program. In this article, we summarize the development of the program in Fiji. In Fiji, the development of marine managed areas was based on the historical system of Qoli-qoli, moderated by the history of British colonialism, wherein local chiefs and villages controlled access to, and rules for the use of, nearshore marine environments.     

Lessons Learned from the Marine Management Area Science Program: Insights for Global Conservation Science Programs

Drawing on experiences from the four regions and the overall conduct of the Marine Management Area Science (MMAS) program, this concluding article highlights emergent cross-cutting themes that affected MMAS programs across the regions, summarizes the important conservation outcomes of the MMAS program, and then discusses lessons gained from the actual process of conducting the MMAS program. Based on these insights, particularly the last section, this article concludes with recommendations for other conservation programs, specifically those that are global in scope and are science-based with a specific intent to apply that science to conservation action.     

Performance analysis of polymer electrolyte membrane (PEM) fuel cell stack operated under marine environmental conditions

The marine environmental condition, especially NaCl, has been identified as one of the major sources of contamination on the performance of open cathode Proton Exchange Membrane Fuel Cells (PEMFC) system, when the power source is based on fuel cells for marine applications like submarines, navy ships etc., In the present paper, we have studied the performance of PEMFCs under the marine environment for a longer duration and also the recovery mechanism of the PEMFC power pack after contamination. It has been observed that the NaCl is a major contaminant for PEMFC, compared to NO _x and SO _x , which are major contaminants for fuel cells operating in the land regions. We have observed a performance loss of 60 % in PEMFC, when operated for 48 h, due to poisoning of PEMFC by NaCl vapours. The recovery of the stack is attempted by repeated water washing on the cathode side of the fuel cell, presuming that the salts get deposited only on the surface of the electrodes and the performance is easily recoverable. The recovery mechanisms are analysed by constant-current discharging operation and by modified experimental methods and are reported here. The performance vagaries in fuel cells due to sea water contamination is also analysed by linear fit and it is found that the rate of power increment after water wash is higher than the rate of power increment, around 11.5 W/10?h compared to normal environmental conditions, which is 4.1 W/10?h.     

The perception and image of shipping

The image of the shipping industry plays a vital role in developing maritime transport as a major future, sustainable transport alternative. In particular, it is crucial to understand the image the shipping industry has among young people and the anatomy of the concept in order to be able to effectively promote careers in shipping, to cultivate shipping as an attractive labour market and to develop attractive educational programmes. The focus of this paper is the image of the shipping industry. This study reports on the findings of a large-scale survey of the image of shipping- and image-related concepts among upper secondary school pupils in Sweden, Norway and Greece. We define and analyse empirically by means of multivariate statistical analysis the anatomy of the image concept. We identify various image dimensions, estimate how young people rate the shipping industry along these dimensions and estimate their relative importance to young people who are planning their future careers. The results from this study can be used as a base for describing and explaining the images that young people have of the shipping industry. Such knowledge is fundamental for deriving and developing constructive strategies to promote careers in shipping, to adapt shipping to the expectations of young people and to develop creative and relevant educational programmes. Finally, understanding the image of shipping among young people is important not only for the shipping industry, but for other stakeholders as well, such as ship-owners associations, trade associations, labour unions, transport authorities and administrations and policy makers at the national and supra-national level.     

Contractual PPPs for Transport Infrastructure in Spain: Lessons from the Economic Recession

In this paper, we analyse the successes and failures of contractual public-private partnerships (PPPs) for delivering and operating transport infrastructure in Spain from the award of the first toll highway concession programme to the present. To that end, we show the risk allocation principles used in Spain and explore the evolution of the contracting approaches over the years. We found that the performance was reasonably good until the arrival of the economic crisis in 2008. Taking advantage of that, we make a review of contractual PPPs for different transport modes and assess the impact that the economic crisis has had on their business performance and the capacity of the central and regional governments to fulfil their commitments with the private sector. This analysis enabled us to identify measures that, if had been applied, would have improved the resilience of these contract during the economic crisis.