Cat food left out for feral and domestic cats and bird seed spilled from backyard bird feeders are two common anthropogenic food sources that may attract non-target animals like urban mesocarnivores but no studies have quantified mesocarnivore visitation at these food sources. We used motion-activated video cameras to monitor mesocarnivore use of spilled bird seed below 25 bird feeders maintained by residents in four neighborhoods in Flagstaff, Arizona, June-September 2012 and 2014. During the first five nights of monitoring only seed that spilled naturally below feeders was available. On each of the subsequent five nights, we placed a bowl of commercially available dry cat food below feeders so that both spilled seed and cat food were present. In both years, after cat food was added, the number of visits by striped skunks (Mephitis mephitis), raccoons (Procyon lotor) and domestic cats (Felis cattus) doubled and the number of times two animals were present simultaneously also increased. Aggressive interactions, in the form of displays or contacts, increased for all species combinations but significantly only between skunks in the presence of cat food. These results demonstrate that both spilled bird seed and cat food may be exploited frequently by urban mesocarnivores and that the type of food can elicit different behavioral responses that could have important implications for human-wildlife conflict and disease transmission.

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Mechanisms affecting particle transport in wafer processing environments include: sedimentation, convective diffusion, thermophoresis, eleetrophoresis, and photophoresis. The first two mechanisms are universal; they exist everywhere and at all times. The latter three mechanisms, however, depend on conditions that can be introduced and used to minimize particle deposition on product wafers. This paper reviews theoretical models of all five mechanisms and describes procedures and hardware configurations that use one or more of the three controllable mechanisms to protect wafers from particulate contamination.

This paper reports on a program comparing calculated and experimental values of particle deposition velocity at pressures down to 100 pascals (1 millibar). The calculated values were obtained by incorporating the pressure dependence of gas density and the Cunningham slip correction factor into previously published particle deposition models. While the deposition mechanisms modeled included sedimentation, diffusion, thermophoresis, electrophoresis, and photophoresis, experimental measurements have been made so far to verify only the sedimentation model. The experimental results presented confirm the predicted increased importance of gravitational settling at subatmospheric pressures.

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