Analysis of CH2_{2}O x OH as marker for fuel-rich air to pure oxy-fuel flames under higher preheat temperature and elevated pressure

The scope of the present work is a numerical and experimental investigation about the range of validity in terms of applicability of CH$_{2}$OxOH as a marker for the heat release rate (HRR) for fuel-rich air to pure oxy-fuel flames including preheating and elevated pressure. Therefore, laminar, freely propagating 1d CH$_{4}$ flames were calculated, where oxygen content in the oxidizer (from air to pure oxy-fuel combustion), inlet temperature and pressure were varied for a wide range of the equivalence ratios. The preheat temperature and pressure were parametrically changed from 300 K to 573 K and 1 bar to 5 bar, respectively. Different reaction mechanisms were used, namely GRI30, DLR, USC/II, Caltech2.3 and ABF. The performance of the CH$_{2}$OxOH as a marker for HRR is assessed in terms of correlation coefficients of their profiles in laminar flames. The comparison of the obtained correlations of CH$_{4}$/air and CH$_{4}$/O$_{2}$ flames shows that in case of air combustion, the HRR can be accurately estimated by the product of CH$_{2}$OxOH for slightly rich flames (Φ = 1.5), whereas the quality of the correlation degrades with increasing equivalence ratio. In contrary, the correlation coefficient increases with higher equivalence ratios in the fuel-rich domain for enhanced oxygen contents in the oxidizer. For pure oxyfuel combustion, the best correlation is found at an equivalence ratio of approximately Φ = 3.0. Elevated pressure leads in all flames to better correlations at lower equivalence ratios compared to standard inlet conditions, whereas preheating induces the opposite trend and expands the valid regime. A series of CH$_{4}$/air flames were also investigated experimentally in a range of the equivalence ratio between 1 < Φ < 2 at standard inlet conditions. The qualitative CH$_{2}$O (excitation at 355 nm) and OH (excitation at 283 nm) concentration were resolved applying two-dimensional LIF for flames stabilized at a McKenna burner. Comparisons show similar trends for measurements and numerical simulations

Combustion Characterization of Solvents used in Coil Coating Processes: Experiments and Kinetic Modelling

A combined experimental and chemical kinetics modelling approach is presented to account for the combustion behaviour of solvents utilized in coil coating processes. Heating values and laminar burning velocities of typical industrial solvent formulations comprising alcohols, ethers, esters and aromatics are experimentally investigated. Due to the complexity of species participating in the solvent formulations surrogate solvents are introduced, one for each considered formulation. An “in-house” chemical kinetics mechanism has been extended in order to take into account the solvents’ combustion and consists of 321 species participating in 1826 reactions. Its overall performance is validated against the laminar burning velocity measurements. A good qualitative and quantitative reproduction of the experimental curves is depicted with maximum discrepancies observed in the range of 10-15%

Regulation of Tumor-Stromal Fibroblast Interactions: Implications in Anticancer Therapy

Recent advances in tumor biology have identified the stroma as an important regulator of carcinogenesis and potentially a valuable therapeutic target. While however the fact that by targeting the stromal component of a tumor represents a potential therapeutic strategy has been established, the knowledge for specific regulators for such interactions remains poor. The latter is largely due to the fact that appropriate methodological approaches that permit the screening for such regulators are lacking. In the present review we will summarize some of the literature underlining the central role of stromal factors, and essentially that of the fibroblasts in tumorigenesis. Furthermore, we will review the experimental evidence that suggest that by interfering with tumor-stroma interactions may represent a therapeutic approach. Finally, based on various experimental evidence and theoretical considerations we will suggest a biological experimental system which might facilitate the screening of such regulators

Swyer-James (MacLeod&apos;s) syndrome following pertussis infection in an infant

Pertussis is a potentially severe disease, especially in infancy. The case of an 8-month-old infant is described who presented the typical radiographic image of unilateral hyperlucent lung or Swyer-James (MacLeod&apos;s) syndrome. The infant suffered from pertussis at 20 d of age. A rare postinfectious complication of pertussis is reported

Experimental determination of fuel evaporation rates using IR-thermography

The scope of the present work is to experimentally investigate the heat and mass transfer phenomena occurring in the case of pure liquid as well as FAME-diesel fuel mixture droplets evaporating in a constant temperature and constant air velocity environment. Experiments have been performed to record the time evolution of droplet diameter and surface temperature. An ultrasonic droplet acoustic levitator has been operated in order to suspend the isolated droplets in air. A fast CCD camera and an infrared camera have been used to record droplet diameters and droplet surface temperatures, respectively. The produced experimental data can be used in the validation of computational and empirical models for single, pure liquid or multicomponent droplet evaporation. 1