Pilot-Scale Evaluation of H2O2 Injection to Control NOx Emissions

Nitric oxide (NO) in combustion flue gasses can be converted to higher oxidation states by the injection of aqueous solutions of hydrogen peroxide (H2O2) into the hot flue gases. The NO is oxidized to NO2, HNO2, and HNO3, which can then be removed in a wet scrubber. A pilot plant system that was designed, constructed, and operated at Kennedy Space Center confirmed previous results that H2O2 is very effective at oxidizing NO; conversions of NO above 90% were obtained at temperatures of about 500°C (930°F) using mole ratios of H2O2:NOx slightly above 1.0. The mole ratios of H2O2∕NOx needed to obtain high conversions of NO were significantly lower in the pilot plant that they had been in previous laboratory studies, demonstrating that this process can be an economically feasible method for NOx control. The position of the injector and the type of atomization were very important to the efficient utilization of peroxide. When SO2 was present in the flue gas, both NO and SO2 were oxidized without increasing the demand for peroxide.     

Disseminated xanthosiderohistiocytosis with cardiac involvement and monoclonal gammapathy

Xanthosiderohistiocytosis is a rare non-Langerhans histiocytosis (4 reported cases). The clinical characteristics include diffuse, sometimes deep, dark-brown infiltrations of the skin. Histological examination reveals abundant deposits of haemosiderin within the histiocyte proliferation. This entity is a clinical form of Montgomery's disease (xanthoma disseminatum) which has been reported in over 100 cases. Our case of disseminated xanthosiderohistiocytosis was particular because it involved the heart and was associated with a monoclonal gammapathy. Five cases have been reported associating xanthoma disseminatum and monoclonal gammapathy, including one case of xanthosiderohistiocytosis. In our case, rapidly increasing levels of monoclonal immunoglobulin suggested an evolution towards a myeloma. A monoclonal gammapathy should be looked for and monitored in cases of xanthosiderohistiocytosis, and more generally xanthoma disseminatum because of the risk of developing lymphoma or myeloma.     

Modified Wilson's Model for Correlating Solubilities in Supercritical Fluids of Some Polycyclic Aromatic Solutes

Since developing mathematical models is extremely useful to determine solubilities of various solutes in supercritical fluids (SCFs); in this work, the “expanded liquid” approach is adopted to predict the solubility of some polycyclic aromatic solutes (with different size, functionality, and polarity) in diverse SCFs. A modified form of the Wilson's model is proposed for predicting the solubilities of the considered binary systems by computation of the activity coefficient based on the local composition concept. Effect of high operating conditions is considered via the variation of the molar volume of the solute. The proposed correlation achieves an overall and average AARD of 9.2% and 7.8%, respectively, on a range of 1.14% to 19.9%, these results show that the predicted solubility data are in good agreement with the experimental ones. Moreover, dependence of binary parameters on density and some solute's characteristics is discussed on the base of their course versus solvent reduced density.     

Feature learning and encoding for multi-script writer identification

International Journal on Document Analysis and Recognition (IJDAR) - Writer identification from handwriting samples has been an interesting research problem for the pattern recognition community in...     

Hydroxyapatite growth on multiwall carbon nanotubes grown on titanium fibers from a titanium sheet

Nano-hydroxyapatite (HA) was grown on functionalized multiwalled carbon nanotubes (MWCNTs) deposited on TiO₂ nanofibers (NFs) that were hydrothermally grown on Ti metal sheets. The HA was electrochemically grown on the MWCNTs/TiO₂ porous layer. It was found that the HA grows on the MWCNTs/TiO₂ NFs in the form of dense coating with nanorice grain-shaped. The incorporation of MWCNTs between HA and TiO₂ NFs has led to higher adhesion strength as measured by micro-scratching test indicating the benefit of MWCNTs on the improving the bonding strength of HA layer. The obtained coatings exhibit excellent corrosion resistance in simulated body fluid. It is expected that this simple route for preparing the new HA/MWCNTs/TiO₂/Ti-layered structure might be used not only in the biomedical field, but also in catalysis and biological sensing among others.     

Identification of 8-Hydroxyquinoline Derivatives That Decrease Cystathionine Beta Synthase (CBS) Activity

CBS encodes a pyridoxal 5′-phosphate-dependent enzyme that catalyses the condensation of homocysteine and serine to form cystathionine. Due to its implication in some cancers and in the cognitive pathophysiology of Down syndrome, the identification of pharmacological inhibitors of this enzyme is urgently required. However, thus far, attempts to identify such molecules have only led to the identification of compounds with low potency and limited selectivity. We consequently developed an original, yeast-based screening method that identified three FDA-approved drugs of the 8-hydroxyquinoline family: clioquinol, chloroxine and nitroxoline. These molecules reduce CBS enzymatic activity in different cellular models, proving that the molecular mechanisms involved in yeast phenotypic rescue are conserved in mammalian cells. A combination of genetic and chemical biology approaches also revealed the importance of copper and zinc intracellular levels in the regulation of CBS enzymatic activity—copper promoting CBS activity and zinc inhibiting its activity. Taken together, these results indicate that our effective screening approach identified three new potent CBS inhibitors and provides new findings for the regulation of CBS activity, which is crucial to develop new therapies for CBS-related human disorders.     

A contribution-based service differentiation scheme for peer-to-peer systems

Trust is required in a file sharing peer-to-peer system to achieve better cooperation among peers. In reputation-based peer-to-peer systems, reputation is used to build trust among peers. In these systems, highly reputable peers will usually be selected to upload requested files, decreasing significantly malicious uploads in the system. However, these peers need to be motivated by increasing the benefits that they receive from the system. In addition, it is necessary to motivate free riders to contribute to the system by sharing files. Malicious peers should be also motivated to contribute positively by uploading authentic files instead of malicious ones. Service differentiation is required to motivate peers to get involved by sharing and uploading the requested files. To provide the right incentives for peers to contribute to the system, the new concept of Contribution Behavior is introduced for partially decentralized peer-to-peer systems. In this paper, the Contribution Behavior of the peer is used as a guideline for service differentiation instead of peer’s reputation. Both Availability and Involvement of the peer are used to assess its Contribution Behavior. Performance evaluations confirm the ability of the proposed scheme to effectively identify both free riders and malicious peers and reduce the level of service provided to them. On the other hand, good peers receive better service. Simulation results also confirm that based on a Rational Behavior, peers are motivated to increase their contribution to receive services. Moreover, using our scheme, peers must continuously participate, reducing significantly the milking phenomenon.

Comparison between PI-DTC-SPWM and fuzzy logic for a sensorless asynchronous motor drive

Currently, asynchronous cage motors are among the most commonly requested machines accentuated by their extension to the field of electric vehicles. Therefore, the development of robust and sophisticated controls for this machine is of significant interest. Artificial intelligence control techniques, such as fuzzy logic, are at the forefront of recent research. However, their design becomes much more complicated for a motor via a multilevel inverter. The main purpose of this paper is to show that it is possible to achieve fuzzy logic control of a squirrel cage asynchronous motor supplied via the usual two-level inverter. This is achieved, by adopting a DTC strategy based on a sinusoidal PWM with multilevel inverter. It employs a feedback information estimator with dual structure between the sliding mode observer at low speed and the model reference adaptive system in sliding mode at high speed. For both installations, speed is regulated using a sliding mode controller.     

Batch sorption dynamics and equilibrium for the removal of cadmium ions from aqueous phase using wheat bran

Studies on a batch sorption process using wheat bran as a low cost sorbent was investigated to remove cadmium ions from aqueous solution. The influence of operational conditions such as contact time, cadmium initial concentration, sorbent mass, temperature, solution initial pH, agitation speed and ionic strength on the sorption kinetics of cadmium was studied. Pseudo-second-order model was evaluated using the six linear forms as well as the non-linear curve fitting analysis method. Modeling of kinetic results shows that sorption process is best described by the pseudo-second-order model using the non-linear method. The sorption of cadmium was found to be dependent on initial concentration, sorbent mass, solution pH, agitation speed, temperature, ionic strength and contact time. The value of activation energy (12.38 kJ mol(-1)) indicates that sorption has a low potential barrier corresponding to a physical process. Sorption equilibrium isotherms at different temperatures was determined and correlated with common isotherm equations such as Langmuir and Freundlich models. It was found that the Langmuir model appears to well fit the isotherm data but a worse correlation was obtained by the Freundlich model. The five Langmuir linear equations as well as the non-linear curve fitting analysis method were discussed. Results show that the non-linear method may be a better way to obtain the Langmuir parameters. Thermodynamic parameters such as DeltaH degrees, DeltaS degrees and DeltaG degrees were calculated. These parameters indicate that the sorption of cadmium by wheat bran is a spontaneous process and physical in nature involving weak forces of attraction and is also endothermic.