S.a. Shojaosadati, M.r. Rezaei and B. Rasouli,
Volume 18, Issue 1 (4-1999)
Abstract
In this research the microorganism was initially isolated and selected after evaluation based on COD reduction of cheese whey and biomass production. The selected microorganism was identified as Trichosporon sp. The cultivation conditions of the microorganism were optimized under batch: temperature 30˚C initial pH = 6 aeration speed = 2 ν.ν.m and agitation rate: 800 rpm. Under these conditions, the specific growth rate and biomass doubling time were measured as 0.59 h-1 and 1.16 h, respectively. The COD reduction and biomass production under optimized batch conditions after 24 hours were obtained as 52% and 8.73 g L-1, respectively. The optimized conditions under continuous cultivation were: temperature, 30˚C agitation rate, 800 rpm aeration speed, 2 ν.ν.m dilution rate, 0.42 h-1 pH in fermentor, 4-5. Under these conditions the biomass production, COD reduction and productivity were obtained as: 8.17 g L-1, 53.21%, and 3.4 g L-1 h-1 respectively.
The nutritional value of biomass was evaluated for crude protein, nucleic acid, fat, ass and moisture content. According to the results, the single cell protein obtained in this research is suitable and valuable for animal and poultry feed.
Sh Rezaei, M Eskandari-Ghadi, M. Rahimian,
Volume 36, Issue 1 (9-2017)
Abstract
The acoustic wave velocity depends on elasticity and density at most materials, but because of anisotropy and especially piezoelectric coupling effect, the acoustic wave propagation at piezoelectric based crystalloacoustic materials, is an applied and challenging problem. In this paper, using modified Christoffel's equation based on group velocity concept, the effect of anisotropy and piezoelectric coupling at different wafers of lithium niobate crystalloacoustic (strong anisotropy) on acoustic wave velocity (semi-longitudinal, semi-vertical transverse wave and semi-horizontal transverse wave) is investigated, and validated by experimental data. Then, the acoustic wave velocity ranges that can be supported are determined. The result of this study can be essential at acoustic metamaterials design, Phononic crystal and piezoelectric based wave-guides.
