Abstract: Embodiments are provided for improving storage of file ACLs. A plurality of ACLs are assigned corresponding unique ACL IDs and are stored in an indexed list. The indices of the ACLs in the list are mapped to the ACL IDs, which have a fixed defined size. The ACL ID for a given ACL is stored in a file or directory metadata structure. The ACL ID is then used to obtain the stored ACL, to determine for a user, access permission to the file or directory. The ACLs are stored once in the file system and their ACL IDs are duplicated, instead of the ACLs, in files as needed. Duplicating the ACL IDs instead of the ACLs in the files preserves storage space. Further, duplicating the ACL IDs instead of the ACLs in the files reduces the files sizes, which further improves file system efficiencies.

Abstract: A modular component is provided for use in a system for inerting void spaces in aircraft. The modular component is comprised of a hollow fiber membrane and tubesheet bundle, a low-temperature ozone converter, a hollow fiber membrane shell, and separator endcaps. The ozone converter can be any low-temperature converter with an ozone removal catalyst capable of high ozone removal efficiencies in the temperature range of 100 to 300° F. The modular component may further be used in a system comprising an additional low-temperature and high-temperature ozone converter upstream of the modular component.