You can also search electronic dissertations on TUBdok and get some information about your opportunity to publish online. We publish the dissertations Open Access. If you want to distribute your dissertation at another publisher parallelly, you should check the conditions of a parallel publication. Most publishers allow a parallel distribution on a universities institutional repository like tub.dok.
Besides theses any other publication associated with the TUHH may be published on tub.dok. For example there are preprints, reports and TUHH-series on tub.dok.