Remember that this is a technical, scientific paper. It is very rare that it is okay to use the words, "I", "we", "woulda", "nowadays", etc. Be specific and objective.
Some links that may help when writing abstracts:
https://owl.english.purdue.edu/owl/resource/656/1/
http://writingcenter.unc.edu/handouts/abstracts/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3136027/
Some links that may help when writing a scientific paper:
http://abacus.bates.edu/~ganderso/biology/resources/writing/HTWsections.html#abstract
http://www.columbia.edu/cu/biology/ug/research/paper.html
http://www.scidev.net/global/publishing/practical-guide/how-do-i-write-a-scientific-paper-.ht