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31.
The stability of a fed-batch bioreactor operated with a new control strategy (ED-TOC) during a long-term period was evaluated. The ED-TOC strategy uses solely measurements of DO concentration and volume of the reactor to control the influent flow rate, and so the substrate degradation rate oscillates around its maximal value during the whole filling phase. The bioreactor was tested for the degradation of a wastewater containing 4-chlorophenol (4CP) as a model of an inhibitory compound. The experiment was conducted twice in order to investigate whether results were reproducible. Each set of experiments consisted of two phases: acclimation of the biomass to 4-chlorophenol and operation using the ED-TOC strategy. The main conclusion is that the reactor operated by the ED-TOC strategy is robust and stable in large operation periods. Degradation efficiencies greater than 99% as 4CP and greater than 97% as COD degradation were obtained. Toxicity analysis demonstrates that the bioreactor operated by ED-TOC eliminates the toxicity in the wastewater. Community analysis by DGGE was also conducted. 相似文献
32.
Different interpretations of innovation and innovativeness lead to different approaches and different methods to measure organizational output innovativeness. Two indicators of innovativeness are derived from two divergent approaches: the Referent Innovativeness Index and the Classification Innovativeness Index. The article uses the case of the popular music festival to discuss how these indexes can be operationalized and calculated, as well as to outline the implications of the differences between the methods. 相似文献
33.
Microbiological and Physicochemical Quality Changes in Frankfurters Made from Jumbo Squid (Dosidicus gigas) Mantle Muscle in the Presence and Absence of a Natural Antimicrobial Agent
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34.
Human-induced floor vibrations can be mitigated by means of active control via an electromagnetic proof-mass actuator. Previous researchers have developed a system for floor vibration comprising linear velocity feedback control (LVFC) with a command limiter (saturation in the command signal to avoid actuator overloading). The performance of this control is highly dependent on the linear gain utilised, which has to be designed for a particular excitation and might not be optimum for other excitations. This work explores the use of on-off nonlinear velocity feedback control (NLVFC) as the natural evolution of LVFC when high gains and/or significant vibration level are present together with saturation in the control law. Firstly, the describing function tool is employed to analyse the stability properties of: (1) LVFC with saturation, (2) on-off NLVFC with a dead zone and (3) on-off NLVFC with a switching-off function. Particular emphasis is paid to the resulting limit cycle behaviour and the design of appropriate dead zone and switching-off levels to avoid it. Secondly, experimental trials using the three control laws are conducted on a laboratory test floor. The results corroborate the analytical stability predictions. The pros of on-off NLVFC are that no gain has to be chosen and maximum actuator energy is delivered to cancel the vibration. In contrast, the requirement to select a dead zone or switching-off function provides a drawback in its application. 相似文献
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Tamariz E Wan AC Pek YS Giordano M Hernández-Padrón G Varela-Echavarría A Velasco I Castaño VM 《Journal of materials science. Materials in medicine》2011,22(9):2097-2109
Chemotropic proteins guide neuronal projections to their final target during embryo development and are useful to guide axons
of neurons used in transplantation therapies. Site-specific delivery of the proteins however is needed for their application
in the brain to avoid degradation and pleiotropic affects. In the present study we report the use of Poly (ethylene glycol)-Silica
(PEG-Si) nanocomposite gel with thixotropic properties that make it injectable and suitable for delivery of the chemotropic
protein semaphorin 3A. PEG-Si gel forms a functional gradient of semaphorin that enhances axon outgrowth of dopaminergic neurons
from rat embryos or differentiated from stem cells in culture. It is not cytotoxic and its properties allowed its injection
into the striatum without inflammatory response in the short term. Long term implantation however led to an increase in macrophages
and glial cells. The inflammatory response could have resulted from non-degraded silica particles, as observed in biodegradation
assays. 相似文献
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A. Minchev Iv. Penchev I. Kh. Tsibranska 《Journal of Engineering Physics and Thermophysics》1984,47(4):1212-1215
A numerical solution is presented to an extraction problem with a variable masstransfer coefficient and variable concentration of the external medium and a nonlinear condition of equilibrium on the surface of the body.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 47, No. 4, pp. 636–639, October, 1984. 相似文献
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