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101.
Annukka E. Mäkinen Chyi-How Lay Marika E. Nissilä Jaakko A. Puhakka 《International Journal of Hydrogen Energy》2013
An exoelectrogenic culture was enriched on 1.0 g/L xylose from a compost sample in two-chamber microbial fuel cells (MFCs). Electricity production was optimized by changing mixing type, external resistance, xylose concentration and pH. Furthermore, the changes in microbial communities after each optimization step were monitored with PCR-DGGE. Electricity production was highly dependent on operational conditions that affected power densities (PD), Coulombic efficiencies (CE), substrate degradation, utilization of soluble metabolites for electricity production and stability of MFC performance. The optimum operational conditions for electricity production were without mixing, 100 Ω external resistance, 0.5 g/L xylose and pH 7. With optimized operational conditions PD of 590 mW/m2 and CE of 82% were obtained. Microbial community composition, consisting mainly of Geobacter sulfurreducens, Escherichia coli, Sphaerochaeta sp. TQ1 and Bacteroides species, was mainly affected by MFC configuration, i.e. electrical connections, which likely affected the anode potential. 相似文献
102.
103.
This study analysed meat consumption patterns among Finnish consumers, considering both stated past changes and intended future changes. Consumer segments with different patterns of and reasons for change were identified. Latent class analysis revealed six consumer clusters that formed three major cluster blocks. The first block, comprising 48% of the consumers, had established consumption patterns and no intentions to change them. In the second block, with 13% of the consumers, consumption patterns had already shifted towards more vegetables and less meat. The third block, with 39% of the consumers, was identified to be in the middle of a change with a general tendency to reduce the use of meat and increase the use of vegetables. Although the environmental effects of meat and animal welfare issues were important reasons for change in some clusters, healthiness was the most salient stated reason for changing consumption habits. 相似文献
104.
This study evaluated the removal of natural organic matter (NOM) and structural changes in the microbial community during infiltration of humic lake water at three artificial groundwater recharge (AGR) sites in Finland. The three sites were at waterworks in H?meenlinna, Jyv?skyl? and Tuusula, sites A, B and C, respectively. Site A used groundwater recharge by both basin and sprinkling infiltration, site B used only sprinkling infiltration, and site C used only basin infiltration. Reductions of total organic carbon at sites A, B and C were 91%, 84% and 74%, respectively, in the winter, and 88%, 77% and 73%, respectively, in the summer. The Finnish national recommended value of 2 mg/l for TOC was achieved at all sites and the TOC of natural groundwater at site C was much lower, at 0.6 mg/l. Large molecular fractions of NOM were removed more efficiently than the smaller ones. Total amount of DAPI-stained cells decreased during infiltration at sites A, B and C in winter by 94%, 94% and 75% and in summer by 96%, 97% and 94%, respectively. Bacterial communities in raw waters and extracted groundwaters were diverse with changes occurring during infiltration, which was shown by DNA extraction followed by PCR of 16S rRNA genes and denaturing gradient gel electrophoresis (DGGE) fingerprinting. While the natural groundwater microbial community was diverse, it was different from that of the extracted groundwater in the AGR area. Simultaneous organic carbon removal and the decrease of bacterial counts during infiltration indicated biodegradation. In addition, the changing DGGE profiles during the process of infiltration, demonstrated that changing environmental conditions were reflected by changes in bacterial community composition. 相似文献
105.
Katkovnik V Astola J 《Journal of the Optical Society of America. A, Optics, image science, and vision》2012,29(1):44-54
We apply a nonlocal adaptive spectral transform for sparse modeling of phase and amplitude of a coherent wave field. The reconstruction of this wave field from complex-valued Gaussian noisy observations is considered. The problem is formulated as a multiobjective constrained optimization. The developed iterative algorithm decouples the inversion of the forward propagation operator and the filtering of phase and amplitude of the wave field. It is demonstrated by simulations that the performance of the algorithm, both visually and numerically, is the current state of the art. 相似文献
106.
The fabrication process and the operation characteristics of a fully roll-to-roll printed resistive write-once-read-many memory on a flexible substrate are presented. The low-voltage (<10 V) write operation of the memories from a high resistivity '0' state to a low resistivity '1' state is based on the rapid electrical sintering of bits containing silver nanoparticles. The bit ink is formulated by mixing two commercially available silver nanoparticle inks in order to tune the initial square resistance of the bits and to create a self-organized network of percolating paths. The electrical performance of the memories, including read and write characteristics, is described and the long-term stability of the less stable '0' state is studied in different environmental conditions. The memories can find use in low-cost mass printing applications. 相似文献
107.
Jaakko Saastamoinen Martti Aho Antero Moilanen Lasse Holst Sørensen Sønnik Clausen Mogens Berg 《Biomass & bioenergy》2010,34(5):728-736
Burning of coal and biomass particles are studied and compared by measurements in an entrained flow reactor and by modelling. The results are applied to study the burning of pulverized biomass in a large scale utility boiler originally planned for coal. A simplified single particle approach, where the particle combustion model is coupled with one-dimensional equation of motion of the particle, is applied for the calculation of the burnout in the boiler. The particle size of biomass can be much larger than that of coal to reach complete burnout due to lower density and greater reactivity. The burner location and the trajectories of the particles might be optimised to maximise the residence time and burnout. 相似文献
108.
Numerical and Experimental Modelling of Gas Flow and Heat Transfer in the Air Gap of an Electric Machine 总被引:1,自引:0,他引:1
This work deals with the cooling of high-speed electric machines, such as motors and generators, through an air gap. It consists of numerical and experimental modeling of gas flow and heat transfer in an annular channel. Velocity and temperature profiles are modeled in the air gap of a high-speed test machine. Friction and heat transfer coefficients are presented in a large velocity range. The goals are reached acceptably using numerical and experimental research. The velocity field by the numerical method does not match in every respect the estimated flow mode. The absence of secondary Taylor vortices is evident when using time averaged numerical simulation. 相似文献
109.
Pivi H‐M Kinnunen Jaakko A Puhakka 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(8):830-834
The effects of chloride ions on chalcopyrite leaching by biologically‐produced ferric sulfate solution and on the iron‐oxidizing culture were determined. Chloride ions significantly increased chalcopyrite leaching by ferric sulfate at 67 °C and 87 °C, but slowed down the leaching at 50 °C. At 90 °C, chloride at 5 g dm?3 (0.25 g Cl? g?1 concentrate) increased the copper yield from 60 to 100% in approximately 2 weeks. Further increase in Cl? concentration did not affect the leaching. Addition of chloride increased both leaching yields and iron precipitation, which shows that the passivation was not due to iron precipitation. A decreased Ag‐potential of 60 mV against an Ag/AgCl reference electrode in the presence of Cl? indicates the accumulation of partially oxidized forms of dissolved sulfur compounds such as thiosulfate and polythionate instead of elemental sulfur and, thus, a decrease in sulfur passivation. A chloride concentration of 5 g dm?3 did not affect the iron oxidation rate of the iron‐oxidizing culture dominated by Leptospirillum ferriphilum. Copyright © 2004 Society of Chemical Industry 相似文献
110.
Dick Danielle M.; Rose Richard J.; Viken Richard J.; Kaprio Jaakko; Koskenvuo Markku 《Canadian Metallurgical Quarterly》2001,110(4):625
Examples of gene–environment interaction in human behavioral data are relatively rare; those that exist have used simple, dichotomous measures of the environment. The authors describe a model that allows for the specification of more continuous, more realistic variations in environments as moderators of genetic and environmental influences on behavior. Using data from a population-based Finnish twin study, the authors document strong moderating effects of socioregional environments on genetic and environmental influences on adolescent alcohol use, with nearly a five-fold difference in the magnitude of genetic effects between environmental extremes. The incorporation of specific environmental measures into genetically informative designs should prove to be a powerful method for better understanding the nature of gene–environment interaction and its contribution to the etiology of behavioral variation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献