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Microsurfacing has been utilized in the United States since 1980 as a maintenance treatment for pavement. This paper reviews the benefits, limitations, and factors that contribute to successful applications of microsurfacing. The history of microsurfacing, as well as a definition and process description of the treatment, is included. The body of scientific work on microsurfacing is shown to promote its use in preventativemaintenance programs, and the potential formicrosurfacing to meet tightening environmental and budgetary restrictions is discussed. Suggestions are given for future research to expand microsurfacing's applications and efficacy stemming from the ability of microsurfacing to be cold-applied and utilize polymers in the bitumen. [ABSTRACT FROM AUTHOR]

Abstract: Conditions appropriate to gas-surface interactions on satellite surfaces in orbit have not been successfully duplicated in the laboratory. However, measurements by pressure gauges and mass spectrometers in orbit have revealed enough of the basic physical chemistry that realistic theoretical models of the gas-surface interaction can now be used to calculate physical drag coefficients. The dependence of these drag coefficients on conditions in space can be inferred by comparing the physical drag coefficient of a satellite with a drag coefficient fitted to its observed orbital decay. This study takes advantage of recent data on spheres and attitude stabilized satellites to compare physical drag coefficients with the histories of the orbital decay of several satellites during the recent sunspot maximum. The orbital decay was obtained by fitting, in a least squares sense, the semi-major axis decay inferred from the historical two-line elements acquired by the US Space Surveillance Network. All the principal orbital perturbations were included, namely geopotential harmonics up to the 16th degree and order, third body attraction of the Moon and the Sun, direct solar radiation pressure (with eclipses), and aerodynamic drag, using the Jacchia-Bowman 2006 (JB2006) model to describe the atmospheric density. After adjusting for density model bias, a comparison of the fitted drag coefficient with the physical drag coefficient has yielded values for the energy accommodation coefficient as well as for the physical drag coefficient as a function of altitude during solar maximum conditions. The results are consistent with the altitude and solar cycle variation of atomic oxygen, which is known to be adsorbed on satellite surfaces, affecting both the energy accommodation and angular distribution of the reemitted molecules. [Copyright &y& Elsevier]

Much of the land reclaimed since enactment of the 1977 Surface Mining Control and Reclamation Act is over-compacted. Excessive compaction in replaced growth media is detrimental to establishment of trees. If trees are to be grown on reclaimed sites, excessive compaction must be alleviated. Dry bulk density and penetration resistance can be used to indicate the level of compaction in replaced growth media. The University of Kentucky has developed reclamation test cells at a surface mine to determine the impact of organic soil supplements on selected soil physical properties of reclaimed sites. The organic soil supplements being evaluated include hardwood bark and straw and manure. Data were collected at the test cells for dry bulk density, maximum penetration depth and penetration resistance. The data show no statistical evidence that applying organic supplements has a major effect on selected soil physical properties in replaced growth media. [ABSTRACT FROM AUTHOR]

Abstract: Loess in North Africa has been investigated using samples from Algeria. The specific gravity, Atterberg limits, grain size distribution and dry density were determined. The hydro-collapsibility properties, due to wetting under different stress levels were measured in single-oedometer tests. The results of this investigation indicate that the properties of Algerian loess are similar to those of loess from many parts of the world, such as Iowa and Libya; they can be classified as silty loess. [Copyright &y& Elsevier]