Waste Management on Dairy Farms in Costa Rica

This report, prepared for the Empresa de Servicios Publicos de Heredia (ESPH), investigates methods to prevent pollution of water caused by wastewater discharge of dairy farms in Costa Rica. The report describes how to determine the farming qualities necessary to implement clean technologies, including polyethylene anaerobic digesters and best management practices

Aviation Safety/Automation Program Conference

The Aviation Safety/Automation Program Conference - 1989 was sponsored by the NASA Langley Research Center on 11 to 12 October 1989. The conference, held at the Sheraton Beach Inn and Conference Center, Virginia Beach, Virginia, was chaired by Samuel A. Morello. The primary objective of the conference was to ensure effective communication and technology transfer by providing a forum for technical interchange of current operational problems and program results to date. The Aviation Safety/Automation Program has as its primary goal to improve the safety of the national airspace system through the development and integration of human-centered automation technologies for aircraft crews and air traffic controllers

Contingency Management Requirements Document: Preliminary Version. Revision F

This is the High Altitude, Long Endurance (HALE) Remotely Operated Aircraft (ROA) Contingency Management (CM) Functional Requirements document. This document applies to HALE ROA operating within the National Airspace System (NAS) limited at this time to enroute operations above 43,000 feet (defined as Step 1 of the Access 5 project, sponsored by the National Aeronautics and Space Administration). A contingency is an unforeseen event requiring a response. The unforeseen event may be an emergency, an incident, a deviation, or an observation. Contingency Management (CM) is the process of evaluating the event, deciding on the proper course of action (a plan), and successfully executing the plan

Network Maintenance and Capacity Management with Applications in Transportation

abstract: This research develops heuristics to manage both mandatory and optional network capacity reductions to better serve the network flows. The main application discussed relates to transportation networks, and flow cost relates to travel cost of users of the network. Temporary mandatory capacity reductions are required by maintenance activities. The objective of managing maintenance activities and the attendant temporary network capacity reductions is to schedule the required segment closures so that all maintenance work can be completed on time, and the total flow cost over the maintenance period is minimized for different types of flows. The goal of optional network capacity reduction is to selectively reduce the capacity of some links to improve the overall efficiency of user-optimized flows, where each traveler takes the route that minimizes the traveler’s trip cost. In this dissertation, both managing mandatory and optional network capacity reductions are addressed with the consideration of network-wide flow diversions due to changed link capacities. This research first investigates the maintenance scheduling in transportation networks with service vehicles (e.g., truck fleets and passenger transport fleets), where these vehicles are assumed to take the system-optimized routes that minimize the total travel cost of the fleet. This problem is solved with the randomized fixed-and-optimize heuristic developed. This research also investigates the maintenance scheduling in networks with multi-modal traffic that consists of (1) regular human-driven cars with user-optimized routing and (2) self-driving vehicles with system-optimized routing. An iterative mixed flow assignment algorithm is developed to obtain the multi-modal traffic assignment resulting from a maintenance schedule. The genetic algorithm with multi-point crossover is applied to obtain a good schedule. Based on the Braess’ paradox that removing some links may alleviate the congestion of user-optimized flows, this research generalizes the Braess’ paradox to reduce the capacity of selected links to improve the efficiency of the resultant user-optimized flows. A heuristic is developed to identify links to reduce capacity, and the corresponding capacity reduction amounts, to get more efficient total flows. Experiments on real networks demonstrate the generalized Braess’ paradox exists in reality, and the heuristic developed solves real-world test cases even when commercial solvers fail.Dissertation/ThesisDoctoral Dissertation Industrial Engineering 201

A Review of Traffic Signal Control.

The aim of this paper is to provide a starting point for the future research within the SERC sponsored project "Gating and Traffic Control: The Application of State Space Control Theory". It will provide an introduction to State Space Control Theory, State Space applications in transportation in general, an in-depth review of congestion control (specifically traffic signal control in congested situations), a review of theoretical works, a review of existing systems and will conclude with recommendations for the research to be undertaken within this project

Pulsed river flooding effects on sediment deposition in Breton Sound estuary, Louisiana

Louisiana\u27s deltaic coast is a dynamic sedimentary environment made vulnerable by Mississippi River channelization, which restricts freshwater, sediment, and nutrient inputs to adjacent estuaries. Freshwater diversions now reconnect some estuaries with historic fluvial sources, like Breton Sound basin, which receives Mississippi River suspended loads through the Caernarvon freshwater diversion. The project objectives were to quantify short-term sediment accumulation using sediment traps, evaluate sediment trap effectiveness, and compare long-term deposition using feldspar horizon markers and 210Pb dating to the annual sediment trap deposition. Magnitude and variations of sediment deposition at 14 sites were compared during an 18-month study in the upper 415 km2 of Breton Sound estuary, Louisiana. Short-term dry deposition over sediment traps (t=15d) varied for hydrologic pulsing regimes, averaging 3.143 g/m2/d during non-pulsing periods (\u3c183m3/s) and 4.740 g/m2/d during pulsing periods (¡Ý183m3/s). Deposition was greatest near the diversion and decreased with increasing distance from the diversion. Exterior marsh sites (n=5) received more total and allochthonous sediment than interior marsh sites (n=9). Fluvial pulses are significant sediment delivery mechanisms for interior marshes within close proximity (\u3c6km) to the diversion. Exterior marsh deposition is influenced by both fluvial pulsing and resuspension events. Annual deposition over feldspar markers was highly variable but averaged 3.4 cm/yr. In contrast, long-term deposition measured using 210Pb and 137Cs geochronology revealed sedimentation rates within the last 75 years of about 0.12 cm/yr. Near vertical Pb and Cs activities occur within a distinct clay layer attributed to the 1927 flood, where 210Pb dating confirms its origin as circa 1927. Ephemeral short-term sediment deposition is driven by overland flow and highly variable due to prevailing winds and tides. Long-term deposition includes cumulative effects of internal sediment processes, such as compaction and organic matter decomposition, and is more representative of actual accretion rates (i.e., land-building). Estuarine sediment budgets indicate land-building processes are 66% deficient relative to the combined effects of sea level rise, subsidence, and erosion. A critical issue for managing coastal marshes and addressing land loss is elucidated here. Management efforts may be best directed at optimizing estuarine sediment loading based on peaks in river sediment discharge

Hydrolink 2013/4. Hydroinformatics

Topic: Hydroinformatic