Organic carbon budget for the Gulf of Bothnia

We calculated input of organic carbon to the unproductive, brackish water basin of the Gulf of Bothnia from rivers, point sources and the atmosphere. We also calculated the net exchange of organic carbon between the Gulf of Bothnia and the adjacent marine system, the Baltic Proper. We compared the input with sinks for organic carbon; permanent incorporation in sediments and mineralization and subsequent evasion of CO₂ to the atmosphere. The major fluxes were riverine input (1500 Gg C year^− 1), exchange with the Baltic Proper (depending on which of several possible DOC concentration differences between the basins that was used in the calculation, the flux varied between an outflow of 466 and an input of 950 Gg C year^− 1), sediment burial (1100 Gg C year^− 1) and evasion to the atmosphere (3610 Gg C year^− 1). The largest single net flux was the emission of CO₂ to the atmosphere, mainly caused by bacterial mineralization of organic carbon. Input and output did not match in our budget which we ascribe uncertainties in the calculation of the exchange of organic carbon between the Gulf of Bothnia and the Baltic Proper, and the fact that CO₂ emission, which in our calculation represented 1 year (2002) may have been overestimated in comparison with long-term means. We conclude that net heterotrophy of the Gulf of Bothnia was due to input of organic carbon from both the catchment and from the Baltic Proper and that the future degree of net heterotrophy will be sensible to both catchment export of organic carbon and to the ongoing eutrophication of the Baltic Proper.     

Simulation of Dynamical Behaviour of a Front Wheel Suspension

A MacPherson front wheel suspension and its components are modelled with the finite element method. Nonlinearities due to both the geometry and the characteristics of the components (springs, dampers and bushings) are considered. The force due to a given compression/elongation of the spring strut is calculated and compared with experimental results. Kinematical results, change in track width and camber angle, are also shown and compared with experimental results. Good agreement between numerical and experimental results is obtained.     

Indirect Effects to Include in Strategic Environmental Assessments of Transport Infrastructure Investments

Abstract

Indirect effects are important considerations when making consequence analyses in general and in strategic environmental assessments in particular of potential transport solutions and infrastructure plans. The primary objective of this paper is to emphasize the need for a deeper understanding of the long‐term system effects of investments in transport infrastructure with a focus on the structuring effects that roads and railways have on society, e.g. altered transport patterns, altered settlement structures and changes in use of the built environment. Special attention is given to the following potential indirect effects: increased total transport volume, increased share of private motorists and truck transport, increased urban sprawl, and increased energy use in buildings. The conditions that determine the power of the effects are discussed and a number of key factors to be considered in transport infrastructure planning, especially in strategic environmental assessments, are suggested. Since many indirect effects emerge over time, an extended time perspective is of essence. Therefore, scenario techniques may be useful when analysing indirect effects in transport planning processes.     

The risk of whiplash-induced medical impairment in rear-end impacts for males and females in driver seat compared to front passenger seat

The objective of this study was to study whiplash injury outcome in front-seat occupants in rear-end impacts using double paired comparison technique. The combination of gender, seated position, and outcome was analyzed. Folksam, a Swedish insurance company, has a database of whiplash injuries. A questionnaire was used to collect study data. The response rate was 81%. The inclusion criteria included medical impairment one year after the impact, as judged by medical specialists. The study included rear-end impacts between 1990 and 1999 that resulted in at least one permanent neck injury impairment; in total, 430 impacts with 860 occupants and 444 impairments. Of those suffering impairment, 302 were female and 142 male; 235 were seated in the driver's seat and 209 in the front passenger seat. Relative risk estimates for impairing whiplash injury, by gender and seated position:

1.

Driver male (DM)/passenger female (PF) relative risk = 0.5 n = 218     

10大亚洲车系故障难点破解

亚洲汽车厂商生产的车辆一直很受美国消费者欢迎,亚洲品牌汽车经常名列最佳制造车辆的排行榜中.但即使质量再好,也难免有出故障的时候,维修任务就自然落到维修工身上了.……