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The development of microalgae culture technology has been an integral part to produce biomass feedstock to biofuel production. Due to this, numerous attempts have been made to improve some operational parameters of microalgae production. Despite this, specialized research in cell growth monitoring, considered as a fundamental parameter to achieve profitable applications of microalgae for biofuels production, presents some opportunity areas mainly related to the development of specific and accurate methodologies for growth monitoring. In this work, predictive models were developed through statistical tools that correlate a specific micro-algal absorbance with cell density measured by cell count (cells∙per ml), for three species of interest for biofuels production. The results allow the precise prediction of cell density through a logistic model based on spectrophotometry, valid for all the kinetics analysed. The adjusted determination coefficients () for the developed models were 0·993, 0·995 and 0·994 for Dunaliella tertiolecta, Nannochloropsis oculata and Chaetoceros muelleri respectively. The results showed that the equations obtained here can be used with an extremely low error (≤2%) for all the cell growth ranges analysed, with low operational cost and high potential of automation. Finally, a user-friendly software was designed to give practical use to the developed predictive models.  相似文献   
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1. The characteristics of the threshold excitation behavior of the squid giant axon were investigated with condenser discharges, exponentially blunted D. c. shocks, sinusoidal currents, and brief condenser-discharge test shocks superimposed at either electrode at controlled brief intervals following the closing of a constant current. 2. Data obtained by the use of condenser discharges and exponentially blunted currents followed theoretical patterns separately, but could not be mutually reconciled, under the system of the two-factor theories of excitation, since the accommodation was so rapid that the apparent ratio between the two time factors was incompatible with certain previously neglected theoretical limitations. 3. Data obtained with the other procedures indicated similarly rapid accommodation, but usually showed an imaginary component in the values of the time constants, associated with a capacity of the threshold to exhibit damped oscillatory behavior. 4. The anodal threshold behavior did not parallel that at the cathode, showing neither oscillation nor accommodation at ordinary current intensities. 5. The digressions from predictions of the two-factor theories of excitation are partly analyzed and compared with other reported deviations.  相似文献   
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