introduction acetic acid bacteria are large group of obligate aerobic gram negative bacteria with the ability to oxidize ethanol to acetic acid (1). they are widely distributed in natural habitats and classified in family acetobacteraceae. members of this family are useful in industrial production of vinegar(2). acetic acid bacteria (aab) can use substrates as glucose, ethanol, lactate or glyc...

chapter one is devotod to collect some notion and background informations, which are needed in the next chapters. it also contains some important statements which will be proved in a more general context later in this thesis. in chapter two, we show that if the marginal factor-group is of order np1...pk,n>1, then we obtain a bound for the order of the verbal subgroup. also a bound for the bear-...

the purpose of the present study was to investigate the effect of task-based instruction of vocabulary on the receptive and oral productive acquisition of english vocabulary and compare the results with those obtained from the traditional method. the method and procedure applied in this study was as follows: after the implementation of opt, a group of sixty female students were chosen. the stu...

it is not possible to understand developments of a country’s culture and civilization without knowing his believes and myths. whether it is north or south, east or west, planes or mountains, sahara or deserts, here in iran every corner includes valuable and precious treasures which are known all over the world, and cultural – historical objects which are found here adorn all well known museums...

there is no doubt that human being needs to become integrated with industry and industry needs to be progressed, daily. on the other hand, serious events in industrial units specially in oil industries has been shown that such damages and events are industry related ones. the consequence of such events and damages which resulted in chemical and poisoned explosions and loss of life and property ...

the present study is paid to the evaluation of the welfare program of the unemployment insurance in iran. the main purpose which was the main reason for performing this thesis, was the unemployment insurance plan’s challenges in iran such as financial problems of this plan, prolongation of the credit receipt for some insured people, unemployment slow exiting from the unemployment insurance fund...

in this research we have studied the effect of some transition-metals (cu, ag and au) substitutions on two-electron reduction potential of flavins by application of dft method. all geometries have been optimized at blyp level of theory and “6-31+g** + lanl2dz” mixed basis set. the frequency job at the same method and basis sets has been performed to obtain gibbs free energy of compounds. it h...

the issue of curriculum and syllabus evaluation and revision has been in center of attention right from when curriculum came into attention of educational institutions. thus everywhere in the world in educational institutions curricula and syllabi are evaluated and revised based on the goals, the needs, existing content, etc.. in iran any curriculum is designed in a committee of specialists and...

uncertainty in the financial market will be driven by underlying brownian motions, while the assets are assumed to be general stochastic processes adapted to the filtration of the brownian motions. the goal of this study is to calculate the accumulated wealth in order to optimize the expected terminal value using a suitable utility function. this thesis introduced the lim-wong’s benchmark fun...

phatic communion is a cultural concept which differs across cultures. according to hofstede (2001), the u.s. tends to have individualistic culture; however, asian countries tend to have collectivistic cultures. these cultures view phatic communion differently. in individualistic cultures like u.s., phatic communion reflects speakers’ socio-cultural relationships in conversations. to see whether...