Design,Spectroscopy, and Assessment of Cholinesterase Inhibition and Antimicrobial Activities of Novel Coumarin–Thiadiazole Hybrids

A novel series of coumarin–thiadiazole hybrids, derived from substituted coumarin-3-carboxylic acids was isolated and fully characterized with the use of a number of spectroscopic techniques and XRD crystallography. Several of the novel compounds showed intensive fluorescence in the visible region, comparable to that of known coumarin-based fluorescence standards. Moreover, the new compounds were tested as potential antineurodegenerative agents via their ability to act as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. Compared to the commercial standards, only a few compounds demonstrated moderate AChE and BuChE activities. Moreover, the novel derivatives were tested for their antimicrobial activity against a panel of pathogenic bacterial and fungal species. Their lack of activity and toxicity across a broad range of biochemical assays, together with the exceptional emission of some hybrid molecules, highlights the possible use of a number of the novel hybrids as potential fluorescence standards or fluorescence imaging agents.     

Modulations in Chlorophyll a Fluorescence Based on Intensity and Spectral Variations of Light

Photosynthetic efficiency is significantly affected by both qualitative and quantitative changes during light exposure. The properties of light have a profound effect on electron transport and energy absorption in photochemical reactions. In addition, fluctuations in light intensity and variations in the spectrum can lead to a decrease in photosystem II efficiency. These features necessitate the use of a simple and suitable tool called chlorophyll a fluorescence to study photosynthetic reactions as a function of the aforementioned variables. This research implies that chlorophyll a fluorescence data can be used to determine precise light conditions that help photoautotrophic organisms optimally function.     

Adaptability mechanisms for autonomic system implementation with AAOP

This paper presents a new approach to implementing an adaptability loop in Autonomic Computing (AC) systems, which is based on adaptable aspects. The approach utilizes the concept of adaptable aspect‐oriented programming (AAOP) in which a set of AOP aspects is used to run an application in the manner specified by its adaptability strategy. We present a model execution environment based on this concept, enabling the execution of applications with applied adaptability strategies. In the AAOP‐based AC system, the application is instrumented with aspects selected by the system from a set of all available aspects (sensors, effectors, and goal aspects) in such a way that the system can monitor and manage the application. This model can be used to implement systems that are able to monitor an application and its execution environment, and perform actions such as changing the current set of non‐functional constraints in response to changes in the application or its environment. The model can be used for various types of non‐functional goals, in various programming languages, both in centralized and distributed environments. This paper describes its Java‐based implementation and non‐functional goals referring to resource management. As a consequence, the application uses resources in a way specified in its adaptability strategy. Resource consumption management logic is transparent for the application, meaning that no modifications in the application source code are needed. Copyright © 2010 John Wiley & Sons, Ltd.     

Supporting ionic conductivity of Li2CO3/K2CO3 molten carbonate electrolyte by using yttria stabilized zirconia matrix

It is proposed that dual conductive electrolytes have the potential to improve properties of MCFC by using oxygen ion conductors as matrix material, creating what is termed composite electrolyte. In this work we present the results of testing a novel type of electrolyte of molten carbonate fuel cell which consists of Yttria Stabilized Zirconia impregnated by Lithium/Potassium carbonates. Polarization curves were obtained for temperatures between 500 °C and 800 °C. Without very accurate measurements it is not easy to determine the additional electric charge provided by oxygen ions (O⁼). We made an attempt to build a mathematical model which takes into account both conductivities and, based on the model, estimated the ratio of electric charge provided by oxygen ions and carbonate ions.     

Solid state photoluminescence of novel lanthanide complexes based on 4-benzoylpyrazolone Schiff base

A novel, promising ligand for luminescent lanthanide complexes tris-((4-(3-methyl-1-phenyl-5-pyrazolonyl)-phenylmethylidene)-2-aminoethyl)amine (trenPMBP) was prepared and used as effective “antenna” for the ligand-sensitized photoluminescence of Tb³⁺, Dy³⁺ and Sm³⁺ ions. All the complexes show surprisingly intensive photoluminescence in comparison with their simple 4-benzoyl-3-methyl-1-phenyl-5-pyrazolone analogues. One of the reasons of such result can be a relatively high located triplet energy level of trenPMBP around 22675 cm^?1, which properly fits with the emissive energy levels of Tb³⁺ and Dy³⁺ (20430 cm^?1 and 20830 cm^?1, respectively), thus avoiding back-energy transfer from the lanthanide to the ligand.     

Influence of Density Variation on One-Dimensional Modeling of Exhaust Assisted Catalytic Fuel Reforming

Exhaust gas recirculation has become commonplace within the automobile industry to reduce nitrogen oxide emissions because of its ability to lower the combustion temperature. However, it leads to an increase of particulate matter and degradation in fuel economy. One possible avenue for recovering this efficiency is to use exhaust assisted fuel reforming (EAFR) to generate hydrogen by catalytic means using injected fuel and exhaust and add it to the inlet mixture. Adding hydrogen in this manner has shown an increase in combustion stability and efficiency of the engine while reducing particulate matter production. Many classical works use incompressible fluid flow models in order to simulate the reactive flow in monolithic catalyst. However, such models are not appropriate in the case of EAFR, where exothermic reactions cause a large increase in the temperature and consequently in density. To simulate a catalyst undergoing EAFR reactions, a compressible flow solver was used in order to take into account the changes in density. The presented results show the importance of using proper gas dynamics and heat transfer for modeling a flow with catalytic reactions of high exothermicity.