Abstract: The present invention discloses a microbially induced carbonate precipitation (MICP)-based vertical barrier, and a preparation method thereof, wherein a raw material of the vertical barrier includes in-situ soil, Ca-bentonite, a bacteria-containing culture medium, and a cementing solution. The bacteria-containing culture medium comprises flocculent ureolytic bacteria flora. The proportions of dry the Ca-bentonite to in-situ soil, the bacterial-containing culture medium to the cementing solution, and the cementing solution to the Ca-bentonite are specified to be 1:2, (2˜5):1, and (1˜2.5):10, respectively, to ensure optimal performance. The present invention addresses challenges related to the insufficient impermeability of Ca-bentonite-based barriers in the application of vertical barrier, and aims to reduce both the cost and carbon emissions associated with their construction.

Abstract: A Security system for computer transactions incorporates a USB Security Key, a remote terminal and a secure access appliance to provide Security for a central computer. The USB Security Key is coded with a personal digital certificate and is required to be inserted into the remote terminal, along with the input of a personal identification number, before communications with the secure access appliance can be authenticated. The remote terminal is provided only with a central processing unit, random access memory, and restricted access, non-volatile flash memory storage device, which when used with a central computer, eliminates the need to store data on a permanent memory storage device. Software applications can be downloaded from the central computer for operation by the remote terminal. Since the IP address/name of the central computer is hidden by the secure access appliance, the central computer remains secure from unauthorized access and provides an audit trail.