Abstract: Methods, systems, computer-readable media, and apparatuses for management of content presentation within a user interface are presented. Certain embodiments are described that allow for the management of content presentation within a user interface. A channel management subsystem may manage the presentation of content to a user from one or more channels within the social network. The channel management subsystem may receive requests from one or more channels to present content to a user within a user interface (UI) of the social network. The channel management subsystem may grant or deny the received requests based on various rules or criteria. The channel management subsystem may help ensure that the user of the social network is not overwhelmed by the presentation of inorganic content or sponsored content within the UI of the social network.

Abstract: Disclosed is a process for preparing isopimaric acid, comprising the following steps: First step: dissolving thermally isomerized rosin in acetone, adding in drops a solution of isobutanolamine in acetone to form a precipitate, standing, filtering, washing with ethanol, and drying to obtain crude ammonium salt of isopimaric acid; recrystallizing the crude ammonium salt of isopimaric acid according to multi-recrystallization, and drying to obtain purified crystal of ammonium salt of isopimaric acid; Second step: dissolving the purified crystal of ammonium salt of isopimaric acid obtained in the first step in ether, adding hydrochloric acid in portions until the crystal of ammonium salt of isopimaric acid disappears, removing a water layer and washing the ether layer with water to neutral, evaporating the ether, dissolving the residue in acetone, adding water slowly into the solution dropwise until crystals cease to grow, then filtering and drying to obtain purified isopimaric acid.

Abstract: Disclosed is a process for preparing isopimaric acid, comprising the following steps: First step: dissolving thermally isomerized rosin in acetone, adding in drops a solution of isobutanolamine in acetone to form a precipitate, standing, filtering, washing with ethanol, and drying to obtain crude ammonium salt of isopimaric acid; recrystallizing the crude ammonium salt of isopimaric acid according to multi-recrystallization, and drying to obtain purified crystal of ammonium salt of isopimaric acid; Second step: dissolving the purified crystal of ammonium salt of isopimaric acid obtained in the first step in ether, adding hydrochloric acid in portions until the crystal of ammonium salt of isopimaric acid disappears, removing a water layer and washing the ether layer with water to neutral, evaporating the ether, dissolving the residue in acetone, adding water slowly into the solution dropwise until crystals cease to grow, then filtering and drying to obtain purified isopimaric acid.