Environmental risk assessment of the most commonly transported chemicals: case study of Finnish coastal areas

The environmental hazard potential of a total of 15 chemicals that are transported through the Finnish coastal areas was assessed in this paper using a scoring method developed for accidents. The study indicates that the chemicals most commonly transported/handled in Finnish ports are methanol, sodium hydroxide solution, acids, pentanes, phenol, xylenes, methyl tert-butyl ether, ethanol and ethanol solutions. For the evaluation of the environmental hazardousness of various chemicals, a priority list of chemicals that are the most commonly transported regionally in marine environments was compiled for this study. The method used has many similarities to other commonly used scoring systems, but this study gave more weight to specific characteristics of an accidental release, water biota and impact on the environment. Nonylphenol, ammonia and sulphuric acid ranked as the most hazardous substances on the list. The results of the study can be used by rescue and environmental authorities and enterprises to improve preparedness for accidents and to mitigate the effects of accidental spills.     

The effects of the Chinese fiscal system in shipping: a comparison with the UK regime

Assessing the effects of fiscal systems on investment in shipping by using the discounted cash flow technique has recieved much attention over a number of years. This paper examines the recent change in the business environment of Chinese shipping companies and argues for the relevance of using the same technique in the Chinese context. The technique which has been developed over the years is outlined and the current Chinese and UK fiscal systems applied to shipping are described. Based on the comparison and analysis of the effects of the two systems, some policy implications are made.     

Evaluating the impact of legislation prohibiting hand-held cell phone use while driving

As of November 2008, the number of cell phone subscribers in the US exceeded 267 million, nearly three times more than the 97 million subscribers in June 2000. This rapid growth in cell phone use has led to concerns regarding their impact on driver performance and road safety. Numerous legislative efforts are under way to restrict hand-held cell phone use while driving. Since 1999, every state has considered such legislation, but few have passed primary enforcement laws. As of 2008, six states, the District of Columbia (DC), and the Virgin Islands have laws banning the use of hand-held cell phones while driving. A review of the literature suggests that in laboratory settings, hand-held cell phone use impairs driver performance by increasing tension, delaying reaction time, and decreasing awareness. However, there exists insufficient evidence to prove that hand-held cell phone use increases automobile-accident-risk. In contrast to other research in this area that uses questionnaires, tests, and simulators, this study analyzes the impact of hand-held cell phone use on driving safety based on historical automobile-accident-risk-related data and statistics, which would be of interest to transportation policy-makers. To this end, a pre-law and post-law comparison of automobile accident rate measures provides one way to assess the effect of hand-held cell phone bans on driving safety; this paper provides such an analysis using public domain data sources. A discussion of what additional data are required to build convincing arguments in support of or against legislation is also provided.     

Experimental study of the flow induced by a vehicle fan and the effect of engine blockage in a simplified model

Fans are often tested without downstream blockage and, thus, the performance is considerably different when the fan is mounted in a vehicle as part of a cooling system and where high blockage effect is present downstream. The aim of the present work is to analyze by laser Doppler velocimetry LDV measurements the topology of the flow induced by a fan incorporated in a simplified underhood model reproducing engine blockage and to study the blockage effect of the engine positioning on the flow induced by the fan. The distance between the fan and the engine block affects the mean flow axial velocity U. The vertical velocity component W is greatly influenced by the variation of the distance between the fan and the engine block, both in magnitude and topology.     

马不扬鞭自奋蹄 Mazda CX-9

马自达在北美发布了一款7人座的SUV——2007 CX-9，CX-9是针对北美市场开发设计的，它提供了独特而充满活力的设计以及高档的内饰和宽敞的空间。     

The analysis of entropy models with equality and inequality constraints

Entropy models are emerging as valuable tools in the study of various social problems of spatial interaction. With the development of the modelling has come diversity. Increased flexibility in the model can be obtained by allowing certain constraints to be relaxed from equality to inequality. To provide a better understanding of these entropy models they are analysed by geometric programming. Dual mathematical programs and algorithms are obtained.     

An Internal State Variable Model for the Low Temperature Tempering of Low Alloy Steels

QuanitativelyaccuratePredictionsofquenchinduceddistOnionandresidualstressrelyontheabilitytopredictthemicrosthectUralevolUtionthroughOutthequenchProcess.InlowaIloysteels,cUrrenresearchMshavefOcusedontheformationldneticsoffetrite,pearlite,bainiteandmartensite.However,temPeringcanhavealargeinfluenceondistOnionandresidualstrCss,andeffortstoaccountforthislagbehindthemodelingofthePrimnyphasetransihons.AsafirststeptowardsaccountingfortemPerillg,wehavedevelOpedanintemalstatevariablemodelthatuses…     

Emission analysis of a compressed natural gas directinjection engine with a homogenous mixture

In an era in which environmental pollution and depletion of world oil reserves are of major concern, emissions produced by automotive vehicles need to be controlled and reduced. An ideal solution is to switch to a cleaner fuel such as natural gas, which generates cleaner emissions. In addition, control over the in-cylinder air-fuel mixture can be best achieved through a direct-injection mechanism, which can further improve combustion efficiency. This need for cleaner automobiles provides the motivation for this paper’s examination of the use of computational fluid dynamic (CFD) simulations to analyze the concentrations of the exhaust gases produced by a compressed natural gas engine with a direct-fuel-injection system. In this work, a compressed natural gas direct-injection engine has been designed and developed through a numerical simulation using computational fluid dynamics (CFD) to provide an insight into complex in-cylinder behavior. The emissions analyzed in this study were carbon monoxide (CO), nitric oxide (NO) and carbon dioxide (CO₂), i.e. the main pollutants produced by natural gas combustion. Based on a stoichiometric mixture, the concentrations of CO and NO were computed using the dissociation of carbon dioxide and the extended Zeldovich mechanism. CO₂ was calculated using a mass balance of the species involved in the combustion process. The simulation results were then compared with the experimental data generated by a single-cylinder research engine test rig. A good agreement was obtained with the experimental data for the engine speeds considered for all emissions concentrations.     

An analytical investigation of two-dimensional and three-dimensional biplanes operating in the vicinity of a free surface

In the present article, the classical two- and three-dimensional lifting theories are generalized to the biplane operating in proximity to a free surface. The singularity distribution method is employed to calculate the lifting force for a two-dimensional biplane subjected to wing-in-ground effect in the vicinity of a free surface, and the three-dimensional correction is carried out by the aid of the Prandtl lifting line theory. The essential techniques lie in finding the three-dimensional Green’s function for the system of horseshoe vortices operating above a free surface and ensuring numerical implementation. Extensive numerical examples are carried out to show the lift coefficient for the two- and three-dimensional biplanes in the vicinity of a free surface with the variation of the clearance-to-chord ratio and the height-to-chord ratio. Incidentally, the induced (inviscid) drag coefficients as well as the lift-to-drag ratio for a three-dimensional biplane are also computed. Good agreement can be found among results obtained from this study and the experiment.     

Cost-minimizing retrofit/replacement strategies for diesel emissions reduction

The cost effectiveness of various emission reduction diesel retrofits is analyzed, as is early vehicle retirement. An integer program is developed to find cost-minimizing cleanup strategies, given reduction goals for various pollutants, as well as technological and budget constraints. Retrofits are assumed to take place in the present, but benefits and costs can be distributed over time. Budget constraints deal with short-term expenditures, while the overall objective is to minimize the net present value of short and long-term costs. The model is intended as a tool both for fleet owners and for government administrators. A case study examines the potential to clean up a diesel school bus fleet.