Use of the task configuration system (TCS) for the design and on-line optimization of power plants operating with variable loads

The main purpose of this work is to show the ability of the TCS (task configuration system) to perform both the design and the operation optimization of power plants. The TCS is a module that permits to set the main task of each one of the equipments of the system and consequently setting how they respond to variable loads. In this work, the TCS was applied to a micro cogeneration plant of 60 kW in which both the electrical and the thermal loads were variable. Primarily, the design optimization of the nominal power of the equipments and of the TCS configuration was performed for the loads and electricity/fuel costs assumed in the design. After this operational optimizations in cases where the loads and electricity/fuel costs were doubled and then halved in relation to the standard case were performed. The results presented the TCS in a very robust way in most of the cases even the operational conditions being very different from the originally assumed. Based on the results, it is possible to defend the use of the TCS to decrease the risk of high initial investments made in cogeneration systems.     

Fluorescence studies on the interaction between pyrene‐labelled poly(acrylic acid) and cyclodextrins

The interactions, in aqueous media, between a pyrene‐labelled polyelectrolyte poly(acrylic acid) (PAAMePy) with two different degrees of labelling and β‐ and γ‐cyclodextrins (β‐ and γ‐CD) were studied using absorption and fluorescence (steady‐state and time‐resolved) techniques. In addition to qualitative and quantitative parameters obtained from absorption and steady‐state fluorescence spectra, time‐resolved fluorescence data are presented, allowing additional important observations regarding the nature of the interactions. From the overall data it was possible to conclude that in the case of interaction with γ‐CD the efficient encapsulation of two pyrene units into the cavity of the cyclodextrin molecule leads to a decrease in the number of available free monomers and an increase in the number of preformed ground‐state dimers (GSDs) of pyrene. It was also shown that contrary to the situation in water, where only intramolecular interactions are present, the addition of γ‐CD leads to new interpolymeric interactions. The absence of significant changes is noted when the interactions of PAAMePy polymers take place with β‐CD. The excimer‐to‐monomer fluorescence intensity ratio (I_E/I_M) was found to increase with the added amount of γ‐CD but not with β‐CD. This increase is justified on the basis of the increase of the GSD contribution. The photophysical behaviour was found to be dependent on the pH of the media, but with the absence of relevant interactions between CD and PAAMePy polymer at alkaline values. Copyright © 2007 Society of Chemical Industry     

Frequency Selective Surfaces with Anisotropic Dielectric Superstrates

A full wave analysis is developed for frequency selective surfaces composed of rectangular patches mounted on a dielectric anisotropic substrate and covered with a uniaxial anisotropic superstrate. The moment method is used in combination with the spectral domain immittance approach to determine the FSS structure reflection and transmission coefficients.     

Temperature-Dependent Re-alignment of the Short Multifunctional Peptide BP100 in Membranes Revealed by Solid-State NMR Spectroscopy and Molecular Dynamics Simulations

BP100 is a cationic undecamer peptide with antimicrobial and cell-penetrating activities. The orientation of this amphiphilic α-helix in lipid bilayers was examined under numerous conditions using solid-state ¹⁹F, ¹⁵N and ²H NMR. At high temperatures in saturated phosphatidylcholine lipids, BP100 lies flat on the membrane surface, as expected. Upon lowering the temperature towards the lipid phase transition, the helix is found to flip into an upright transmembrane orientation. In thin bilayers, this inserted state was stable at low peptide concentration, but thicker membranes required higher peptide concentrations. In the presence of lysolipids, the inserted state prevailed even at high temperature. Molecular dynamics simulations suggest that BP100 monomer insertion can be stabilized by snorkeling lysine side chains. These results demonstrate that even a very short helix like BP100 can span (and thereby penetrate through) a cellular membrane under suitable conditions.     

In vitro and in vivo inhibition of Hass avocado polyphenol oxidase enzymatic browning by paeonol, β-cyclodextrin,and paeonol:β-cyclodextrin inclusion complex

1. Download : Download high-res image (257KB)
2. Download : Download full-size image

     

Removal of lindane using electrokinetic soil flushing coupled with air stripping

Journal of Applied Electrochemistry - This paper evaluates the remediation of soil spiked with lindane using a combined treatment consisting of electrokinetic soil flushing (EKSF) with air...     

Impact assessment of odours emitted by a wastewater treatment plant

Complaints from the Domingos Martins population about sewage odours in the city made the district attorney order an impact assessment of the odours emitted by the city wastewater treatment plant (WWTP). This study comprised various techniques, models and population surveys. In 2007, an odour emission model proved that the main hydrogen sulphide emitter was the aeration tank of the WWTP (13.5 g h(-1)) and such emissions, according to CALPUFF model, should be perceived in the whole Domingos Martins city centre area. In this area, 58% of those interviewed were annoyed by the WWTP odours. However, in 2009, the odour monitoring panel recorded few odour occurrences. A second population survey showed that hereafter only 20% of those interviewed were annoyed by the WWTP emissions. Odour emission and dispersion models run with 2010 data proved a drastic reduction of the WWTP aeration tank emissions and consequently the city centre was not bothered by WWTP emissions anymore. The odour emission reduction was due to the modification of the WWTP aeration tank system. Despite the odour emission reduction, houses located southeast of the WWTP were still annoyed by sewage odours. However, in this part of the town, other sources of sewage odours have been found.