Is to have an official approved calculator provided by the university - students can get to handle it in the admin office before the examination. We also provide official foreign language dictionaries for the examination upon request. It is the university wide policy which applies to all examinations and the students are informed up front.

I too archive all my emails. The solution I use is quite simple compared to others proposed here.

I have postfix deliver a copy of all mails to an archive directory with mailbox file per year as well as to my inbox (or other mailboxes depending on filtering rules). Each archival mailbox file is about 5GB compressed.

Filtering these mailboxes by header using mutt is a very fast operation and even doing in-body searches and views takes less time than it takes gzip to uncompress the files. Obviously they can easily be backed up in the usual ways.

3DEs uses 2 keys but 3 cycles - one key is used twice

These systems typically have short range in air and thus require many antennas closely spaced. The consequence is that distances are smaller and therefore, due to the inverse square law, the power needed at each antenna is much smaller and the average power in the environment will be much smaller.