Temporal variations in the cometary mass distribution

Mass Flows in Cometary UCHII Regions

High spectral and spatial resolution, mid-infrared fine structure line observations toward two ultracompact HII (UCHII) regions (G29.96 -0.02 and Mon R2) allow us to study the structure and kinematics of cometary UCHII regions. In our earlier study of Mon R2, we showed that highly organized mass motions accounted for most of the velocity structure in that UCHII region. In this work, we show tha...

Distribution of Retrograde Cometary Dust Particles in the Solar System

The Size Distribution of Jupiter-family Cometary Nuclei

Introduction: We are continuing our program to determine the size distribution of cometary nuclei. We have compiled a catalog of 105 measurements of 57 cometary nuclei, drawn from the general literature, from our own program of CCD photometry of distant cometary nuclei (Lowry and Weissman [1]), and from unpublished observations by colleagues. We model the cumulative size distribution of the nuc...

Temporal Variations in the Abundance and Composition of Biofilm Communities Colonizing Drinking Water Distribution Pipes

Pipes that transport drinking water through municipal drinking water distribution systems (DWDS) are challenging habitats for microorganisms. Distribution networks are dark, oligotrophic and contain disinfectants; yet microbes frequently form biofilms attached to interior surfaces of DWDS pipes. Relatively little is known about the species composition and ecology of these biofilms due to challe...

Spatial and Temporal Distribution of Zooplankton Biomass in the Northeast Persian Gulf

The zooplankton biomass and distribution were studied during two oceanographic cruises in NE part of the Persian Gulf in autumn 2012 (November) and summer 2013 (August) with 300 μmmesh net. Zooplankton samples were analyzed for biomass content. Zooplankton biomass expressed as mg m-3 dry wt., was greatest during summer cruise (mean of 18.8 ± 4.6 mg m-3 dry wt.). The mean zooplankton bioma...