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Abstract: Single radioactive particle tracking was used to measure the overall solids residence time (and its distribution) in the riser of a CFB, operating at superficial air velocities (U) of 1 to 9ms−1 and solids circulation fluxes (G) between 20 to 600kg m−2s−1. The results demonstrate that the particle motion and mixing differ according to the operating mode of the riser, with a fairly constant velocity throughout the riser achieved in the dilute or dense riser flow, but with a significant amount of back-mixing for intermediate values of U and/or G. This back-mixing is due to the core-annulus mode of particle flow. Whereas experimental results and theoretical predictions are in fair agreement for the dilute and dense riser flow, the core-annulus regime needs to account for a U and G dependent slip factor (φ), in excess of the commonly proposed value φ=2, especially at U–UTR <2ms−1. Moreover, the previously published riser operation diagram is confirmed by the experiments, although a further analysis of the core-annulus regime is needed. [Copyright &y& Elsevier]

Abstract: Caledonian Paper (CaPa) is a major paper mill, located in Ayr, Scotland. For its steam supply, it previously relied on the use of a Circulating Fluidized Bed Combustor (CFBC) of 58 MWth, burning coal, wood bark and wastewater treatment sludge. It currently uses a bubbling fluidized bed combustor (BFBC) of 102 MWth to generate steam at 99 bar, superheated to 465 °C. The boiler is followed by steam turbines and a 15 kg/s steam circuit into the mill. Whereas previously coal, wood bark and wastewater treatment sludge were used as fuel, currently only plantation wood (mainly spruce), demolition wood, wood bark and sludge are used. Since these biosolids contain nitrogen, fuel NO x is formed at the combustion temperature of 850–900 °C. NO x emissions (NO + NO2) vary on average between 300 and 600 mg/Nm3 (dry gas). The current emission standard is 350 mg/Nm3 but will be reduced in the future to a maximum of 233 mg/Nm3 for stand-alone biomass combustors of capacity between 50 and 300 MWth according to the EU LCP standards. NO x abatement is therefore necessary. In the present paper we firstly review the NO x formation mechanisms, proving that for applications of fluidized bed combustion, fuel NO x is the main consideration, and the contribution of thermal NO x to the emissions insignificant. We then assess the deNO x techniques presented in the literature, with an updated review and special focus upon the techniques that are applicable at CaPa. From these techniques, Selective Non-catalytic Reduction (SNCR) using ammonia or urea emerges as the most appropriate NO x abatement solution. Although SNCR deNO x is a selective reduction, the reactions of NO x reduction by NH3 in the presence of oxygen, and the oxidation of NH3 proceed competitively. Both reactions were therefore studied in a lab-scale reactor and the results were transformed into design equations starting from the respective reaction kinetics. An overall deNO x yield can then be predicted for any operating temperature and NH3/NO x ratio. We then present data from large-scale SNCR-experiments at the CFBC of CaPa and compare results with the lab-scale model predictions, leading to recommendations for design and operation. Finally the economic impact is assessed of implementing SNCR-technology when applying an NH3 SNCR or urea SNCR to the CFBC at CaPa. [Copyright &y& Elsevier]

Background Interleukin 10 (IL-10) is a cytokine with potent anti-inflammatory properties that play a fundamental role in restrictive host immune response to pathogens, by means of that is a crucial importance for chronic inflammatory disease studies. Therefore, the goal of this study was to measure the correlation of the IL-10 gene polymorphisms with the susceptibility to Behçet's disease compared with the control group in the Azeri population and to determine the expression of this gene in the two groups. Also, real-time PCR was performed for evaluate the IL-10 mRNA expression of the associated polymorphisms. Methods In this study, blood samples from 47 (1 missed) patients and 58 (3 missed) healthy control were taken, and then mononuclear cells isolated with ficoll protocol. The DNA and RNA were subsequently extracted. They were examined for −592A/C (rs1800872) of IL-10 gene single nucleotide polymorphism (SNP) using RFLP-PCR. Allele and genotype distributions were evaluated among groups using chi-square or Fisher’s test. Following this, the extracted RNA was converted to cDNA using the RT-PCR method, after that expression of IL-10 evaluated by Real-time PCR. Serum levels of IL-10 were measured using Enzyme-linked immunosorbent assay (ELISA). Results Rates of the rs1800872 A allele was statistically lower in the control group compared with BD patients (p = 0.0315 and OR = 1.90 (1.05–3.42)). Also, as we expected, the expression level of the IL-10 gene was seen to significantly decrease in the patient group compared to the control. Conclusions Our study showed that the rs1800872 A allele of the IL-10 gene may contribute to the genetic susceptibility of BD by regulating the expression of IL-10. Also as we expected, the expression level of this gene was seen to significantly decrease in the patient group compared to the control. [ABSTRACT FROM AUTHOR]