RESUMEN
Improving the combustion efficiency of solid fuels is important for reducing carbon monoxide emissions in the iron ore sintering process. In this paper, the surface steam spraying technology is introduced in the sintering process based on the auxiliary combustion effect of steam on coke, and its potential to reduce carbon monoxide emissions is demonstrated. Thermogravimetric analysis experiments of coke breeze in air and air-steam mixed atmosphere are carried out, and the results show that the introduction of steam can reduce the concentration of carbon monoxide in the exhaust gas from 183×10-6 to 78×10-6. At the same time, the mechanisms of carbon monoxide emission reduction by surface steam spraying technology are analyzed from the thermodynamic and kinetic perspectives. Then, a series of laboratory-scale sintering pot tests are carried out under no spraying operation, interval spraying operation, and continuous spraying operation. The results indicate that both interval and continuous spraying operations can reduce carbon monoxide emissions. The optimal mode of steam spraying under the present experimental conditions is continuously spraying for 13 min at a volume rate of 0.053 m3/min. Compared with no spraying, the average carbon monoxide concentration in the exhaust gas is reduced from 7565×10-6 to 6231×10-6, and total carbon monoxide emissions for per ton sinter are reduced from 13.46 m3/t to 9.51 m3/t.
RESUMEN
Uncoupling proteins (UCPs) belong to the family of mitochondrial transporter proteins and mediate regulated proton leak across the inner mitochondrial membrane. The UCPs play an important role in energy homeostasis and reactive oxygen species (ROS) release, and have been established as candidate genes for obesity, diabetes and hypertension. This study examined the possible association between the single nucleotide polymorphisms (SNPs) of UCP1-3 genes and essential hypertension (EH) in a northeastern Han Chinese population. A total of 2207 Chinese Han subjects were enrolled, including 1045 normotensives and 1162 hypertensives. Genotyping of UCP1 rs1800592, UCP1 rs12502572, UCP2 rs659366, UCP2 rs660339, and UCP3 rs3781907 was detected using Sequenom MassArray System. SHEsis was used to analyze linkage disequilibrium and haplotype. No evident association was observed between the genotype distributions and allele frequencies of individual SNPs and EH. Haplotype analysis showed the haplotype GAATA (rs1800592-rs12502572-rs659366-rs660339-rs3781907) was significantly associated with lower EH risk (p = 0.001, χ2 = 10.861, OR = 0.634, 95% CI = 0.483-0.833), and AGATG was associated with increased EH risk (p = 0.012, χ2 = 6.287, OR = 1.265, 95% CI = 1.052-1.521). These findings suggest haplotypes of UCP1-3 genes are linked to EH risk in a northeastern Han Chinese population. Further investigation with larger sample size in multiethnic population is needed to confirm our results.