Search results for "Kinetic"

Subtype-specific endothelin-A and endothelin-B receptor desensitization correlates with differential receptor phosphorylation.

1998

In the rat cardiovascular system endothelin-1 (ET-1) elicits prolonged physiologic responses mediated by the ET A receptor, whereas the effects mediated by the ET B receptor are transient. The molecular mechanisms for the subtype-specific responses are not yet clear. However, post-translational modifications such as phosphorylation and palmitoylation may play an important role. In Sf9 cells overexpressing the human ET A and ET B receptors, both subtypes are palmitoylated. However, only the ET B but not the ET A receptor is phosphorylated in a ligand-dependent manner. Because phosphorylation is believed to play an important role in ligand-dependent receptor inactivation, we analyzed whether …

Modelling and dynamic simulation of hybrid moving bed biofilm reactors: model concepts and application to a pilot plant.

2011

In the recent years, there has been an increasing interest in the development of hybrid reactors, especially in the up-grading of existing activated sludge plants that are no longer able to comply with concentration limits established by regulatory agencies. In such systems the biomass grows both as suspended flocs and as biofilm. In this way, it is possible to obtain a higher biomass concentration in the reactor, but without any significant increase of the load to the final clarifier. The paper presents the setting-up of a dynamic mathematical model aimed at quantitatively describing the biokinetic processes occurring in a hybrid moving bed biofilm reactor (HMBBR), and, more in general, in…

Hybrid moving bed biofilm reactors: an effective solution for upgrading a large wastewater treatment plant

2009

Over the last few years there has been a growing attention regarding the receiving water body quality state. As a matter of a fact, the Directive 91/271 of the European Union (EU) replaced the “emission standard” concept that fixes discharge limits depending on polluting emission characteristics, with the “stream standard” concept that fixes discharge limits for each polluting substance depending on self-depurative characteristics of the RWB. In this context, several WWTPs need to be upgraded in order to meet stricter effluent limits. The need of WWTP upgrading was also emphasized by the growing urbanization that have led, in most cases, to get overloaded WWTP due to an overcoming of the ma…

Hybrid moving bed biofilm reactors: a pilot plant experiment.

2008

The growing increment of the urbanization and on the other hand, the even more strict effluent limits imposed by the Water Framework Directive for the receiving water body quality state have lead to a need of upgrading several existing WWTP. With this respect HMBBR systems are an innovative solution since allow to upgrade existing high loaded WWTP without building new tanks. However, some uncertainties in their design, maintenance as well as performance have to be addressed due to their recent acquisition compared with well consolidated technologies such as activated sludge systems. In this light, a data gathering campaign on a HMBBR pilot plant has been performed. The aim was to detect the…

A methodology to assess the energetic valorization of bio-based polymers from the packaging industry: pyrolysis of reprocessed polylactide

2012

The energetic valorization process of bio-based polymers is addressed in this study, taking polylactide (PLA) as model. The pyrolysis of virgin and multiple-injected PLA was simulated by means of multi-rate linear-non-isothermal thermogravimetric experiments. A complete methodology, involving control of gases, thermal stability and thermal decomposition kinetics was proposed. The release of gases was monitored by Evolved Gas Analysis of the fumes of pyrolysis, by in-line FT-IR, with the aid of 2D-correlation IR characterization. A novel model to establish the thermal stability of PLAs under any linear heating profile was proposed. A kinetic strategy was methodically applied to assess the th…

Nonlinear control of an activated sludge aeration process: use of fuzzy techniques for tuning PID controllers

1999

In this paper, several tuning algorithms, specifically ITAE, IMC and Cohen and Coon, were applied in order to tune an activated sludge aeration PID controller. Performance results of these controllers were compared by simulation with those obtained by using a nonlinear fuzzy PID controller. In order to design this controller, a trial and error procedure was used to determine, as a function of error at current time and at a previous time, sets of parameters (including controller gain, integral time and derivative time) which achieve satisfactory response of a PID controller actuating over the aeration process. Once these sets of data were obtained, neural networks were used to obtain fuzzy m…

Kinetics and Muscular Function in Ski Jumping

2010

ACL Rehabilitation Enhanced by 3D Modeling Software

2010

The main purpose of this paper is to show possible positive effect of 3D modeling application in rehabilitation. Authors provide clinic example of patient with ACL reconstruction. The patient has undertaken the therapy consisting of regular rehabilitation sessions as well as those enhanced by 3D rehabilitation application. The improvement in ACL rehabilitation was significant and worth further exploration.

Validation of portable 2D force binding systems for cross-country skiing

2013

The aim of the present study was to design, construct and scientifically validate a two-dimensional force measurement binding system for cross-country skiing. The system consists of two force measurement bindings. One binding was designed for analysing classic skiing (vertical and anterior–posterior [along the ski] force components) and the other one for skate (freestyle) skiing (vertical and medio-lateral [transverse to the ski] force components). Validation was accomplished using a three-step process: (1) accuracy tests for the sensors in two temperatures, (2) sport-specific imitation jump test on standard force plates in a laboratory and (3) comparing the system against force measurement…

Sorption Equilibria of Ethanol on Cork

2013

International audience; We report here for the first time a thermodynamic study of gaseous ethanol sorption on raw cork powder and plate. Our study aims at a better understanding of the reactivity of this material when used as a stopper under enological conditions, thus in close contact with a hydroethanolic solution, wine. Sorption−desorption isotherms were accurately measured by thermogravimetry at 298 K in a large range of relative pressures. Sorption enthalpies were determined by calorimetry as a function of loading. Sorption−desorption isotherms exhibit a hysteresis loop probably due to the swelling of the material and the absorption of ethanol. Surprisingly, the sorption enthalpy of e…