Abstract

The karst process acts as carbon sequestration for atmospheric CO2 . The amount of karst carbon sequestration (KCS) depends on the discharge of karst catchment and inorganic carbon concentration of the water body. Based on the data from the monitoring station on Banzhai subterranean stream located in Maolan National Nature Reserve of Guizhou province, the process and influence factors of KCS have been analyzed. It shows that the amount of KCS is about 353 t C per year in the catchment of Banzhai subterranean stream, and there is good linear relationship between the strength of KCS and discharge of the stream at various time scales. Therefore, how to monitor the discharge accurately is the key to the estimation of KCS. And stations with real-time monitoring function are very important for KCS calculation because of strong seasonal variability of the karst water cycle. He, S.-Y., Z.-Q. Kang, Q.-Y. Li, et al., 2012: The utilization of real-time high resolution monitoring techniques in karst carbon sequestration: A case study of the station in Banzhai subterranean stream catchment. Adv. Clim. Change Res., 3(1), doi: 10.3724/SP.J.1248.2012.00054.

Abstract

This research comprises monitoring, assessment and recommendations for chemical risk originating from organic vapors (benzene, toluene and xylene) of fuel (super and extra gasoline) to which attendants at a gas station are exposed. Given the concentration measured of organic vapors (benzene, toluene and xylene) the chemical risk to which attendants are exposed in the supply area is acceptable. Control measures are recommended to ensure healthy working conditions for gas station attendants and also to avoid occurrence of occupational diseases in the medium or long term

Abstract

International audience; The ability of air traffic controllers to deal with complex situations is a limiting factor in airspace capacity. The underlying airspace structure and other procedural elements are thought to be important factors in reducing a controller's cognitive complexity through the use of structure based abstractions. Because cognitive complexity cannot be directly observed it must be investigated indirectly. This paper discusses and presents examples of how directly observable states and controllers' subjective responses can be used to indirectly probe and gain insight into how structure based abstractions are used to manage cognitive complexity.

Abstract

International audience; This paper addresses the classical graph partitioning problem applied to the air network. We consider an air transportation network with aircraft inducing a control workload. This network has to be partitioned into K balanced sectors for which the cutting flow is minimized.

Abstract

The phenomena of packing and wear of the ballast, under dynamic stresses lead to high frequencies and high maintenance costs. It has been demonstrated that the settlements in the ballast were linked to the high accelerations produced in this layer by the passage of high-speed trains. The solution with bituminous underlay was used since the 1980s in several countries like the United States, Italy, Spain, especially on high-traffic and high-speed lines (HSL). In France, the interest in this technique is recent. Following the satisfactory behavior of the East European HSL, a layer of asphalt concrete was made under the ballast layer on a high scale lane, the Bretagne-Pays de la Loire (BPL) fast lane. It is intended, among other things, to reduce the amplitude of the accelerations produced at the passage of the HST."br" The HSL BPL has 105 km of innovative track with an asphalt concrete (GB) sublayer under the ballast, and 77 km with a granular under layer. In order to study the dynamic responses of these different structures and to understand the effect of the different layers on the dynamic response, four sections were instrumented (3 with asphalt concrete, and one on a standard granular structure) using, among others, accelerometers, strain gauges, temperature probes, etc. More than 100 sensors have been installed on the structure in different positions and depths. The acquisition of the data is made during the speed up test phase under controlled conditions with the same train passing with speeds going up from 160 to 352 Km/h. In a later phase, measurements of all the sensors will be treated under actual traffic. The BPL lane is subjected to commercial traffic since July 2017."br" The main idea of the project and the expected results for the first phase are to analyze the measurements in the database created and determine the responses of the different sections and the variations of the various parameters measured: Vertical displacements, accelerations at different levels, horizontal deformations in the bituminous layer, etc."br" In this paper, a description of the railway track “Bretagne pays De la Loire”, the instrumentation of the different sections and the acquisition system are detailed. The processing and treatment method used for the registered data is explained. The variation of the speed of the trains is also expected to be carried out in this paper to evaluate the behavior of the structures in section 4 with bituminous underlayment in terms of vertical acceleration.

Abstract

International audience; Performance metrics in the air traffic management (ATM) community are becoming a strategic issue, and they are getting more and more attention. However, defining such metrics is a difficult problem. In this paper, we show how arithmetic simulations can be used to give performance information. We also point out that many different metrics can be defined, each of them giving different results regarding efficiency. We conclude that an extreme caution must be applied when interpreting results.