This paper reports the development and testing of two independent, innovative techniques for measuring rail displacements. One system combines remote video monitoring with particle image velocimetry, using a webcam and a small telescope. The second uses sleeper mounted geophones that give a voltage output proportional to the velocity of motion, which can be filtered and integrated to calculate displacements. Laboratory validation tests show that the video monitoring system can measure peak-to-peak displacements to within 0.04 mm from a distance of 15 m for frequencies less than 4 Hz. The geophones measure peak-to-peak displacements to within 0.07 mm for frequencies as low as 1 Hz. Data from three different standards of railway track and/or train speeds are used to explore and quantify the limitations of each system in the field.
The paper considers factors that determine the oxygen balance in extreme climate waste stabilisation ponds during the critical spring warm-up period. At this time BOD load on the pond is a maximum, due to accumulation of wastewater under the ice during the winter. The paper describes the operation of a typical cold climate WSP and the events leading to a balanced steady state system as spring develops into summer. A mathematical model to simulate conditions within a batch fed experimental pond over the transient period is described. To model temperature changes in the water body experimental data were fitted to a generalised equation based on diurnal fluctuations in air temperature. The results are plotted in a normalised form and show the diurnal fluctuation and time lapse as the depth of the pond increases. Maximum daily water temperature lags behind maximum light intensity. Bacterial growth is simulated by a Monod kinetic model in which growth rate depends on initial substrate concentration; temperature compensation is applied using a temperature activity coefficient. Oxygen utilisation is calculated from substrate removal. Algal growth rate is more complicated as it is affected by temperature and light availability. Algal oxygen production potential is considered in terms of its primary metabolite yield, which is then used in a Monod equation to estimate the growth rate. The model uses a mass balance approach to determine dissolved oxygen concentration in the pond. The model is still in a simple form but shows reasonable agreement, in terms of events and time lapses, to measured parameters in experimental ponds recovering from ice cover.
The Aral Sea environmental crisis has been created by poor water management in the river basins of the Amu Darya and Syr Darya. Nearly all the flow is abstracted for ailing irrigation schemes in the upper and middle basins, for massive river basin transfer schemes, or is lost to evaporation and seepage from reservoirs and canals. The only solution to the crisis in the lower deltas is to allow more water to flow to them. The paper argues that the only practical approach for achieving this in the short-to-medium term is better water management in the upper and 2 middle river basins, and that a more rational basis for allocating water to meet the needs of all users is urgently required. The paper describes a real-time water resources management model for the Syr Darya river that has been designed for sustainable planning and management of the water resources to meet the needs of all riparian users. The power and limitations of such models in relation to effective management of the water resources of the Aral Basin are discussed. L'efficacité de tels modèles est ici évaluée en fonction de l'objectif poursuivi dans le cas du bassin versant de l'Aral. RESUME
The paper presents a brief review of the application of WSPs in extreme climates where ice formation occurs during winter. Design standards and methods are compared and different systems are described. Design equations developed by the US EPA and normative standards from the former Soviet Union are compared in a simple example using typical wastewater and performance characteristics. The results are similar except at low temperatures, where the Soviet method can give pond depths outside the prescribed limits. The paper examines construction and operational aspects of extreme climate WSPs, comparing North American, Northern European and Russian standards. It considers why WSP systems have not been widely adopted in Russia and the NIS, and looks at the advantages these systems may have in countries in economic transition.
This research examined the requirements for multiple travelers to request a local, medium-distance, national, or international itinerary plan from any node of a public transport journey planner system using timetable or schedule data from numerous public transport companies and modes. It was resolved that a four-tier, client-server architecture and a distributed data service would best meet these requirements, using the Internet to exchange trip schedule data according to an agreed JourneyWeb protocol based on extended markup language. The JourneyWeb protocol is explained, and the field characteristics and attributes used in mutual data interrogation between itinerary planning services, allowing the web of services to expand, are defined. Successive iterations of a prototype system, first between two counties and then expanded to include a larger geographic area, demonstrate progress to date using real schedule data.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.