Эффективность использования игры скрэбл (Scrabble) для закрепления лексики (английский язык, технический вуз)

Rhodobacter capsulatus was used for the phototrophic hydrogen production on effluent solution derived from the thermophilic fermentation of Miscanthus hydrolysate by Thermotoga neapolitana. Pretreatments such as centrifugation, dilution, buffer addition, pH adjustment and sterilization were suggested for the effluent before being fed to the photofermentation. Batch-wise experiments showed that R. capsulatus grows and produces hydrogen on the pretreated effluent solution. Moreover, it was found that the hydrogen yield increased from 0.3 to 1.0 L/L-culture by addition of iron to the effluent solution

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Photofermentative hydrogen production from volatile fatty acids present in dark fermentation effluents

In the present study, the growth and hydrogen production of Rhodobacter sphaeroides O.U. 001, was investigated in media containing five different volatile fatty acids (VIA) individually (malate, acetate, propionate, butyrate and lactate) and in media containing mixtures of these acids that reflect the composition of dark fermentation effluents. The highest hydrogen production rate was obtained in malate (24 ml(hydrogen)/I(reactor)h) and the highest biomass concentration was obtained in acetate containing media (1.65 g/l). The substrate conversion efficiencies for different volatile fatty acids were found to vary between 14 and 50%. The malate and butyrate consumption rates were first order with consumption rate constants of 0.026 h(-1) and 0.015 h(-1), respectively. In the case of substrate mixtures, it was observed that the bacteria consumed acetate first, followed by propionate and then butyrate. It was also found that the consumption rate of the main substrate significantly increased when the minor substrates were depleted. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved

Dynamic modeling of temperature change in outdoor operated tubular photobioreactors

In this study, a one-dimensional transient model was developed to analyze the temperature variation of tubular photobioreactors operated outdoors and the validity of the model was tested by comparing the predictions of the model with the experimental data. The model included the effects of convection and radiative heat exchange on the reactor temperature throughout the day. The temperatures in the reactors increased with increasing solar radiation and air temperatures, and the predicted reactor temperatures corresponded well to the measured experimental values. The heat transferred to the reactor was mainly through radiation: the radiative heat absorbed by the reactor medium, ground radiation, air radiation, and solar (direct and diffuse) radiation, while heat loss was mainly through the heat transfer to the cooling water and forced convection. The amount of heat transferred by reflected radiation and metabolic activities of the bacteria and pump work was negligible. Counter-current cooling was more effective in controlling reactor temperature than co-current cooling. The model developed identifies major heat transfer mechanisms in outdoor operated tubular photobioreactors, and accurately predicts temperature changes in these systems. This is useful in determining cooling duty under transient conditions and scaling up photobioreactors. The photobioreactor design and the thermal modeling were carried out and experimental results obtained for the case study of photofermentative hydrogen production by Rhodobacter capsulatus, but the approach is applicable to photobiological systems that are to be operated under outdoor conditions with significant cooling demands

Effect of light intensity, wavelength and illumination protocol on hydrogen production in photobioreactors

Rhodobacter sphaeroides O.U. 001 is a purple non-sulfur bacterium which evolves hydrogen from the breakdown of organic acids under illumination and anaerobic conditions. In this study, the effect of light intensity, light wavelength and illumination protocol on the growth and hydrogen production of R. sphaeroides O.U. 001 was investigated in gas-tight glass photobioreactors with defined medium. The results showed Also it was found that the rate of hydrogen production increased with increasing light intensity and reached saturation at around 270W/m(2) that lack of infrared light (750-950 nm wavelength) decreased photoproduction of hydrogen by 39%. Another factor evaluated was the effect of different illumination protocols on the growth and hydrogen production. It was observed that illumination after inoculation stimulates hydrogen production, increases substrate conversion efficiency and hydrogen production rate; no hydrogen was produced during the dark periods. (c) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved

Biohydrogen production by Rhodobacter capsulatus on acetate at fluctuating temperatures

Hydrogen is a clean energy alternative to fossil fuels. Photosynthetic bacteria produce hydrogen from organic compounds under anaerobic, nitrogen-limiting conditions through a light-dependent electron transfer process. In this study, the hydrogen production efficiency of phototrophic bacteria, Rhodobacter capsulatus and its Hup mutant strain (an uptake hydrogenase deleted strain) were tested on different initial acetate concentrations at fluctuating temperatures with indoor and outdoor photobioreactors. Acetate was effectively metabolized and H(2) was produced at a high rate. Increasing the initial acetate concentration resulted in a shift in the utilization kinetics of acetate from first order to second order. The effects of fluctuating temperature and day/night cycles on hydrogen production were also studied in indoor and outdoor conditions using acetate as the carbon source. Temperature fluctuations and day/night cycles significantly decreased hydrogen production. It was found that the Hup mutant strain of R. capsulatus has better hydrogen productivity than the wild type parent in outdoor conditions

Photofermentative hydrogen production using dark fermentation effluent of sugar beet thick juice in outdoor conditions

In the present study, photofermentative hydrogen production on thermophilic dark fermentation effluent (DFE) of sugar beet thick juice was investigated in a solar fed-batch panel photobioreactor (PBR) using Rhodobacter capsulatus YO3 (hup(-)) during summer 2009 in Ankara, Turkey. The DFE was obtained by continuous dark fermentation of sugar beet thick juice by extreme thermophile Caldicellulosiruptor saccharolyticus and it contains acetate (125 mM) and NH4+ (7.7 mM) as the main carbon and nitrogen sources, respectively. The photofermentation process was done in a 4 L plexiglas panel PBR which was daily fed at a rate of 10% of the PBR volume. The DFE was diluted 3 times to adjust the acetate concentration to approximately 40 mM and supplemented with potassium phosphate buffer, Fe and Mo. In order to control the temperature, cooling was provided by recirculating chilled water through a tubing inside the reactor. Hydrogen productivity of 1.12 mmol/L-c/h and molar yield of 77% of theoretical maximum over consumed substrate were attained over 15 days of operation. The results indicated that Rb. capsulatus YO3 could effectively utilize the DFE of sugar beet thick juice for growth and hydrogen production, therefore facilitating the integration of the dark and photo-fermentation processes for sustainable biohydrogen production. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

Hydrogen production by hup(-) mutant and wild-type strains of Rhodobacter capsulatus from dark fermentation effluent of sugar beet thick juice in batch and continuous photobioreactors

Photofermentative production of hydrogen is a promising and sustainable process; however, it should be coupled to dark fermentation to become cost effective. In order to integrate dark fermentation and photofermentation, the suitability of dark fermenter effluents for the photofermentative hydrogen production must be demonstrated. In this study, thermophilic dark fermenter effluent (DFE) of sugar beet thick juice was used as a substrate in photofermentation process to compare wild-type and uptake hydrogenase-deficient (hup (-)) mutant strains of Rhodobacter capsulatus by means of hydrogen production and biomass growth. The tests were conducted in small-scale (50 mL) batch and large-scale (4 L) continuous photobioreactors in indoor conditions under continuous illumination. In small scale batch conditions, maximum cell concentrations were 0.92 gdcw/L (c) and 1.50 gdcw/L (c), hydrogen yields were 34 % and 31 %, hydrogen productivities were 0.49 mmol/(L (c)center dot h) and 0.26 mmol/(L-c center dot h), for hup (-) and wild-type cells, respectively. In large-scale continuous conditions, maximum cell concentrations were 1.44 gdcw/L (c) and 1.87 gdcw/L (c), hydrogen yields were 48 and 46 %, and hydrogen productivities were 1.01 mmol/(L (c)center dot h) and 1.05 mmol/(L (c)center dot h), for hup (-) and wild-type cells, respectively. Our results showed that Rhodobacter capsulatus hup (-) cells reached to a lower maximum cell concentration but their hydrogen yield and productivity were in the same range or superior compared to the wild-type cells in both batch and continuous operating modes. The maximum biomass concentration, yield and productivity of hydrogen were higher in continuous mode compared to the batch mode with both bacterial strains

Does transcranial direct current stimulation enhance cognitive performance in Parkinson's disease mild cognitive impairment? An event-related potentials and neuropsychological assessment study

Background Parkinson's disease-mild cognitive impairment (PD-MCI) is garnering attention as a key interventional period for cognitive impairment. Currently, there are no approved treatments for PD-MCI and encouraging results of transcranial direct current stimulation (tDCS) combined with other interventions have been proposed, though the efficacy and neural mechanisms of tDCS alone have not been studied in PD-MCI yet