41. The avalanching disturbs and removes a bright surface layer of dust to expose a darker substrate. 42. The running track was renovated in 2003, and received a new surface layer and paint job. 43. Depth profiling is accomplished by combining an electron spectroscopy with a sputtering source that removes surface layers . 44. Collins observed that Armstrong " never transmits anything but the surface layer , and that very sparingly ." 45. Another suggestion is that oil provides a surface layer that prevents plaque or bacteria adhering to teeth. 46. Touching the surface layer compresses the conductive top sheet so that it makes contact with conductive coating. 47. Deck cleaners remove dirt and grime and also the surface layer of dead cells in the wood. 48. The surface has eroded with significant loss of the black and red pigments from the surface layer . 49. They are initially gregarious and feed only on the surface layer of leaves of their food plant. 50. Indeed, rain is rapidly absorbed into the surface layer of porous gravel that covers much of Yakutat.
