Small and very small interstellar grains

Small and Very Small Interstellar Grains

This review summarizes the observational characteristics of those interstellar grains, which are prevented from entering the solar system by interactions with the heliopause. Such grains are typically less than 100 nm in radius and they reveal their presence by interstellar absorption at ultraviolet wavelengths and by non-equilibrium emissions in the red and near-infrared portions of the spectrum.

Interstellar Grains

Overview Submicron solid particles are dispersed through interstellar gas. These interstellar grains absorb and scatter light, thus shielding some regions from ultraviolet radiation, but also limiting our ability to detect photons which have been emitted by astronomical objects. Dust grains reradiate absorbed energy in the in-frared, thus contributing to the overall emission spectrum of astrono...

Small Grains Small Grain Insect and Disease Pest Management

lowing IPM procedures for managing grain aphids. Results Ninety-four percent of the 39 field tests comparing preventive versus IPM practices showed that IPM practices were more profitable. Few fields developed threshold aphid populations so insecticide was not applied and yields were not affected. Money was saved and total pesticide usage was reduced. Surveys of untreated fields over the last t...

Infrared Emission from Interstellar Dust. I. Stochastic Heating of Small Grains

We present a method for calculating the infrared emission from a population of dust grains heated by starlight, including very small grains for which stochastic heating by starlight photons results in hightemperature transients. Because state-to-state transition rates are generally unavailable for complex molecules, we consider model polycyclic aromatic hydrocarbon (PAH), graphitic, and silicat...

Feeding Small Grains to Swine