Sonstige
Filtern
Erscheinungsjahr
- 2016 (3) (entfernen)
Dokumenttyp
- Wissenschaftlicher Artikel (3) (entfernen)
Sprache
- Englisch (3) (entfernen)
Schlagworte
- Bewertung (2)
- Test (2)
- Versuch (2)
- Absorption (1)
- Air pollution (1)
- Air transport (1)
- Autobahn (1)
- Boden (1)
- Crash Test (1)
- Deutschland (1)
- Development (1)
- Diffusion (1)
- Entwicklung (1)
- Evaluation (Assessment) (1)
- Evaluation (assessment) (1)
- Fahrstreifen (1)
- Fahrzeug (1)
- Forschungsarbeit (1)
- Germany (1)
- Geschwindigkeit (1)
- Ground water (1)
- Grundwasser (1)
- Highway design (1)
- Impact test (1)
- Improvement (1)
- Landstraße (1)
- Level of service (1)
- Lufttransport (1)
- Luftverunreinigung (1)
- Measurement (1)
- Merging (1)
- Messung (1)
- Motorway (1)
- Nitric acid (1)
- Prüfverfahren (1)
- Research project (1)
- Rural road (1)
- Safety (1)
- Salpetersäure (1)
- Sicherheit (1)
- Soil (1)
- Speed (1)
- Straßenentwurf (1)
- Test method (1)
- Traffic lane (1)
- Vehicle (1)
- Verbesserung (1)
- Verkehrsqualität (1)
- Verkehrsverflechtung (1)
Institut
- Sonstige (3) (entfernen)
This study aimed to better understand nitrate transport in the soil system in a part of the state of North Rhine-Westphalia, in Germany, and to aid in the development of groundwater protection plans. An advection-diffusion (AD) cell was used in a miscible displacement experiment setup to characterize nitrate transport in 12 different soil samples from the study area. The three nitrate sorption isotherms were tested to define the exact nitrate interaction with the soil matrix. Soils varied in their properties which in its turn explain the variations in nitrate transport rates. Soil texture and organic matter content showed to have the most important effect on nitrate recovery and retardation. The miscible displacement experiment indicated a decrease in retardation by increasing sand fraction, and an increase in retardation by increasing soil organic matter content. Soil samples with high sand fractions (up to 94 %) exhibited low nitrate sorption capacity of less than 10 %, while soils with high organic matter content showed higher sorption of about 30 %. Based on parameterization for nitrate transport equation, the pore water velocity for both sandy and loamy soils were significantly different (P < 0.001). Pore water velocity in sandy soil (about 4 x 10 high 3 m/s) was about 100 to 1000 larger than in loamy soils (8.7 x 10 high 5 m/s). On the other hand, the reduction in nitrate transport in soils associated with high organic matter was due to fine pore pathways clogged by fine organic colloids. It is expected that the existing micro-phobicity increased the nitrate recovery from 9 to 32 % resulting in maximum diffusion rates of about 3.5 x 10 high 5 m/s2 in sandy soils (sample number CS-04) and about 1.4 x 10 high 7 m/s2 in silt loam soils (sample number FS-02).
Established in 1997, the European New Car Assessment Programme (Euro NCAP) provides consumers with a safety performance assessment for the majority of the most popular cars in Europe. Thanks to its rigorous crash tests, Euro NCAP has rapidly become an important driver safety improvement to new cars. After ten years of rating vehicles, Euro NCAP felt that a change was necessary to stay in tune with rapidly emerging driver assistance and crash avoidance systems and to respond to shifting priorities in road safety. A new overall rating system was introduced that combines the most important aspects of vehicle safety under a single star rating. The overall rating system has allowed Euro NCAP to continue to push for better fitment and higher performance for vehicles sold on the European market. In the coming years, the safety rating is expected to play an important role in the support of the roll-out of highly automated vehicles.
The first version of German Highway Capacity Manual was published in 2001. Now, a new version is published in 2015 (HBS 2015). For the new German Highway Capacity Manual, most major chapters are revised and some of them are totally rewritten. The chapter for merge, diverge, and small weaving segments is rewritten in accordance with forthcoming developments in the past 10 years. In this paper, an overview of the chapter in the new German Highway Capacity Manual is presented. Procedures dealing with performance analyses and level of service (LOS) of those segments are introduced both for freeways and rural highways. Differences between the former version and the new version of the chapter in the German Highway Capacity Manual are indicated and discussed. In most of the existing highway capacity manuals, LOS of merge, diverge, and small weaving segments is traditionally defined by speed, volume, or density in critical areas. In that traditional concept several capacity values of different critical areas (merge, diverge, and weaving) as well as upstream and downstream basic segments within the influence areas are evaluated separately. In the new HBS 2015, a new model which considers the total merge, diverge, and weaving segment as an entire object is incorporated. A combined volume-to-capacity ratio (freeways) or a combined density (rural highways) is used for defining the LOS of the total segment. The parameters of the new procedure are functions of the number of lanes of the major road, the number of lanes in the on-ramp or off-ramp, and the predefined geometric design of those segments. The coefficients are calibrated with field data or defined by experts" experiences within a matrix of coefficients. With those procedures, the traffic quality (LOS) can be obtained directly as a function of the volumes or densities on the major road and on the on-ramp or off-ramp respectively. The new procedure has the following advantages: a) a uniform function for all types of merge, diverge, and small weaving segments, b) traffic quality assessment for all critical areas under investigation in one step, and c) the procedure can easily be calibrated. For applications in practice, a set of graphs is provided.