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This paper aims to report the best practices of deicer corrosion control adopted by the Washington State Department of Transportation (WSDOT) to preserve the performance, reliability and value of its highway maintenance equipment assets.

To enable quantitative analyses, data were collected from a site visit to WSDOT, as well as from a survey of maintenance practitioners from various transportation agencies. The direct costs related to equipment corrosion aggravated by the exposure to roadway deicers were analyzed, along with the direct benefits of mitigating such corrosion, using WSDOT as a case study. In addition, the same preliminary cost benefit analysis was conducted for an “average” Department of Transportation in a northern climate.

Both cases show a highly favorable benefit-to-cost ratio for enhanced investment in controlling the risk of deicer corrosion.

It has not yet been possible to confirm this compelling argument because the analysis is partly based on assumptions instead of fully based on actual data.

This work highlights the need to collect the relevant data such that future analysis and sensitivity analysis can be substantiated with actual data on costs and benefits. It concludes with a few suggestions for implementation.

Many components in highway maintenance equipment fleet are at the risk of metallic corrosion, which is exacerbated in service environments where roadway deicers have been applied. This work lays the foundation for future research into this important issue.

A new, replacement weather avoidance radome is now available to commercial airlines for all ATR‐42/72 commuter aircraft from Norton Performance Plastics.

The purpose of this study is to develop laboratory techniques to evaluate the inhibition efficiency of salt neutralizer (SN) solutions in the corrosion protection of metal alloys associated with winter maintenance equipment.

The corrosion resistance of alloys A36, B36 and B152 treated with SNs was evaluated by accelerated corrosion testing (ASTM B117) and electrochemical polarization curves. Characterization of inhibition solutions was performed by contact angle measurements, scanning electron microscopy, ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy.

Salt neutralizer systems act as mixed inhibitors in acidic media by changing the corrosion resistance ability of metal alloys because of the adsorption of surfactant molecules through their hydrophilic heads. The correlation of the corrosion rate of metal alloys and the inhibitor efficiency showed the influence of the SN type, its concentration, its effective adsorption constant and its contact angle on the alloy surface. Salt neutralizers with higher manufacturer’s recommended wash concentrations (MRWC) to critical wash concentration ratio, lower contact angle on the alloy surface and higher K_eff were more successful at preventing corrosion on the alloys tested.

The results of this work provide, for the first time, both quantitative and qualitative information of the properties of washing techniques in the use of effective cleaning strategies for protecting winter maintenance equipment from corrosion. Other state departments of transportation facing similar weather conditions will be benefited by identifying measures and techniques to increase the corrosion resistance of their equipment assets.

Ethylene glycol (EG) solution is a common deicing fluid of the aircrafts. Roller compacted concrete (RCC) used in the runway and the parking apron will be subjected to freeze-thaw cycles in EG solution. The purpose of this study is to find whether RCC can be damaged by the action of freeze-thaw cycles or long-term immersion in EG solution.

Freeze-thaw cycles test and immersion test in EG solution by weight were used to accelerate the degradation of RCC. A compression test and a three-point bending test were carried out in the laboratory to evaluate mechanical properties of RCC. The changes of microstructure were monitored by using scanning electron microscopy and energy-dispersive X-ray analysis.

The results show that RCC specimens have little weight change in both freeze-thaw cycles test and immersion test. The dynamic modulus of elasticity, the compressive strength and the flexural strength of RCC with 250 freeze-thaw cycles in EG solution are decreased by 4.2, 15 and 39 per cent, respectively. The compressive strength is decreased by 35 per cent after 12 months of immersion in EG solution. Micro-cracks occur and increase with the increase in freeze-thaw cycles and immersion test.

The mass ratio of the elements in the crystal is very close to the proportion of elements in CaC₂O₄ (C:O:Ca = 1:1.26:1.6). More attention should be paid to using EG in practical engineering because both the freeze-thaw cycles and the complete immersion in EG solution damage the mechanical properties of RCC.

The latest addition to the Nimonic series of high temperature nickel alloys is Nimonic 105. This new alloy is a development of Nimonic 100, and is given a minimum life to rupture of 50 hours at 7 T/sq. in. and 940 deg. C. It is particularly resistant to corrosion by solid or molten sulphate products of combustion.

In U.K. patent 2229408 Boeing of Canada Ltd describes a thrust deflector system for VSTOL aircraft. The system consists of a number of spaced‐apart, downwardly facing openings arranged along the bottom of the fuselage. The openings are fluidly connected with an outlet of the aircraft engine so that the pressurised gas from the aircraft engine is discharged through the openings and away from the fuselage in discrete spaced‐apart jets. Each opening has thrust vectoring flaps and end plates. Vents allow air to be drawn from the engine bay into the spaces between the jets when the latter are operative, to reduce “suck‐down” of the aircraft.

IN order to appreciate how surface finish affects drag one must be familiar with the main characteristics of boundary layer flow. These have been described in great detail elsewhere, see, for example, Ref. 1, but a brief outline will not be out of place here. At the surface of a body moving through air there is a thin layer of air called the boundary layer in which the velocity relative to the body rapidly falls to zero as the surface of the body is approached. Because of the large velocity gradients across the boundary layer the viscous forces are appreciable there; outside the boundary layer the flow approximates closely to the ideal inviscid flow of classical hydrodynamics. The flow in the boundary layer beginning at the forward stagnation point is usually laminar for some distance, then after a transition region the flow becomes turbulent. The transition region is appreciable in extent at low Reynolds numbers and in turbulent airstreams, but at the Reynolds numbers usual in flight it is short enough to be referred to as a point. Wo now know enough about both laminar and turbulent types of flow over smooth surfaces and the associated frictional forces to be able to calculate with fair accuracy the profile and skin friction drags of a smooth aerofoil given its thickness, Reynolds number and the position of the transition points2. It is found that the skin friction in the laminar boundary layer is much smaller than the skin friction in the turbulent boundary layer; this is illustrated in Fig. 1, which shows the skin friction distribution on one side of a smooth flat plate at a Reynolds number of 107 and with the transition points at 05 c. and 25 c. Fig. 2 shows the variation of drag with the position of the transition point for the flat plate. Similar curves are obtained for aerofoils and bodies of revolution. It is evident that the further back transition occurs the less will be the drag. Fig. 3 illustrates a point that is worth emphasizing, namely, the relative importance of the drag change due to a given transition point movement increases with wing thickness and Reynolds number.