Ministry of Public Works

About: Ministry of Public Works is a based out in . It is known for research contribution in the topics: Water resources & Flood myth. The organization has 446 authors who have published 439 publications receiving 10938 citations.

Non-invasive moisture monitoring within an earth embankment - a precursor to failure

Abstract: An experimental monitoring system is described using electrical resistivity as a proxy for imaging changing moisture content distribution in engineered earthworks. The approach is illustrated using a case history concerning a road embankment constructed of tropical red soil in Kenya. Tropical red soils have highly variable properties, governed by their soil fabric and mineralogy. As earthworks materials, their geotechnical behaviour is extremely sensitive to changes in moisture content and compaction. The relationship between moisture content and electrical resistivity was established in the laboratory on core obtained using a monitored drilling and sampling technique. The non-invasive nature of electrical resistivity surveys was exploited in the design of a monitoring system placed below the pavement in the topmost layers of compacted soil. Monitoring over a period of 18 months is reported, starting prior to the construction of the pavement following the completion of soil compaction. Initially substantial variability in moisture content was inferred from surface monitoring, and even larger changes were seen in corresponding downhole measurements. The moisture content within the body of the embankment stabilised after 6 months, while a moist layer 'trapped' beneath the pavement dissipated over the following 10 months. Two surveys were undertaken during the December rains showed large changes in moisture content had occurred quickly in the surface layers on one side of the embankment. This area subsequently failed as a small landslip and was remediated by additional drainage.

Hydrologic and geomorphic changes resulting from episodic glacial lake outburst floods: Rio Colonia, Patagonia, Chile

Abstract: Glacial lake outburst floods (GLOFs) are a prominent but poorly understood cryospheric hazard in a warming climate. We quantify the hydrologic and geomorphic response to 21 episodic GLOFs that began in April 2008 using multitemporal satellite imagery and field observations. Peak discharge exiting the source lake became progressively muted downstream. At ~40–60 km downstream, where the floods entered and traveled down the main stem Rio Baker, peak discharges were generally 1–2 times the peak annual discharge of this system, Chile's largest river by volume. As such, caution must be applied to empirical relationships relating lake volume to peak discharge, as the latter is dependent on where this observation is made along the flood path. The GLOFs and subsequent periods of free drainage resulted in > 40 m of incision, the net removal of ~25 × 106 m3 of sediment from the source lake basin, and a nonsteady channel configuration downstream. These results demonstrate that GLOFs sourced from low-order tributaries can produce significant floods on major main stem rivers, in addition to significantly altering sediment dynamics.

A Seasonal Analysis of Wind Turbine Characteristics and Wind Power Potential in Manisa, Turkey

Abstract: In this study, wind characteristics and wind energy potential of a site in the western part of Anatolia of Turkey were analyzed using the wind speed data collected during the period 2000 to 2006. The wind speed distribution curves of the investigated location were obtained by using the Weibull and Rayleigh probability density functions based on these data. Monthly mean wind power at the heights 10, 30, 50, and 70m was found. A technical and economic assessment has been made of electricity generation from the wind turbines of capacity 600 kW, 800 kW, 1300 kW, 1500 kW, 2300 kW, and 2500 kW in the investigated site. The yearly energy output and capacity factor produced for the six different turbines were calculated. The capacity factor of wind turbines used in the analysis was found to be between 25 and 34.

CAPM-Based Valuation of Financial Government Supports to Infeasible and Risky Private Infrastructure Projects

Abstract: Driven by acute fiscal problems and disenchantment with the performance of publicly delivered quality services, many governments in both industrial and developing countries are now relying on the private sector to deliver infrastructure services. In the context of private infrastructure financing, the provision of governmental support is not uncommon. The present paper discusses the theoretical framework of the valuation of the financial impact of support on the cost of debt, cost of equity, the expected return on equity (ROE), and the project's net present value (NPV), based on the capital asset pricing model (CAPM) within a single-period context. Special focus is placed on a minimum revenue guarantee, a direct cash subsidy, and a subsidized subordinated debt. This paper shows that a guarantee reduces the cost of debt and can increase or decrease the cost of equity depending on the leverage, while a subsidy increases only the cost of equity. A subsidized subordinated debt increases both the cost of senior debt and the cost of equity. For all cases, all the supports improve the NPV because the expected increase of ROE can more than sufficiently offset any change in the cost of equity. This paper is of interest to academics because it provides the theoretical analysis of how a support can affect the rates of return expected by debt and private equity investors from risky and, probably, infeasible privately financed infrastructure projects. Practitioners, particularly those from the public sector, can also benefit from research findings that may inform decision makers about what support to provide.

Development of a fuzzy logic traffic system for isolated signalized intersections in the State of Kuwait

Abstract: In a conventional traffic signals controller, the lights change at constant cycle time. In many cities, automatic traffic signals are often based on a constant green-to-red cycle. The time period for green light (or red light) to be on is determined based on a stochastic model. The traditional vehicle-actuated control of isolated intersections attempts continuously to adjust green times. The decision to change green light duration involves fuzzy factors that cannot be precisely determined. The main objective of this paper is to develop a fuzzy logic traffic system that considers the two two-way intersections and is able to adjust changes in time intervals of a traffic signal based on traffic situation level. The proposed system has been applied and tested using real data collected from signalized intersection in Hawalli governorate in the State of Kuwait. Twenty-seven iterations have been done; the results show that the proposed fuzzy logic traffic system provides better performance in terms of total waiting time, total moving time, and vehicle queue. Finally, it can be observed from the results that the proposed system can be used to accelerate the cycle time and to give other phases the chance to gain more benefit from the green time lost.