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Hydrocyclones are devices used to separate a discrete phase (solid or liquid) from a continuous liquid phase. Although this partition process is simple and versatile, there are limitations when separating concentrated suspensions with high viscosity. By replacing the cylinder or cone walls of hydrocyclones by a permeable wall, our research group developed the so-called filtering hydrocyclones. Although previous studies have shown that filtering hydrocyclones have a better performance than conventional devices of the same geometry, they were performed with diluted Newtonian suspensions. Thus, the aim of the present work is to evaluate the performance of a filtering and a conventional hydrocyclone of the same geometry operating with concentrate suspensions with pseudoplastic rheological behavior. The geometric relationship of these hydrocyclones was obtained in a previous optimization study that aimed at maximizing overall efficiency in aqueous diluted suspensions; this high-efficiency device is known as MOEH. When operating a pseudoplastic fluid with a behavior index equal to 0.6536, there was a 48% decrease in the efficiency of the MOEH hydrocyclone. The MOEH experiments performed with a pseudoplastic suspension containing 9.5 wt % of solids and 0.6 wt % of carboxymethyl cellulose achieved an Euler number of 1108, a split ratio of 44%, and an overall efficiency of 47%. However, the average results demonstrated that the operation with the newly designed filtering hydrocyclone, called MOEH-CoF, led to an Euler number about 10% lower and an overall efficiency about 5% higher than that obtained with the conventional device. The findings of this study can lead to a better understanding of solid–liquid separation in the petrochemical, mineral, and food industries, which generally works with concentrated non-Newtonian fluids.

No relevant conflicts of interest to declare.

Background: Despite resulting from homozygosity of a single mutation at position 6 of the beta-globin locus, the clinical aspects of sickle cell anemia (SCA) are very heterogeneous. Leg ulcer is one of the many resulting complications, exerting a quite negative impact in the quality of life of patients and is related to the severity of the disease. The pathogenesis of such complication is complex and still not well explained. Objective: Seeking for novel genes associated with leg ulcer in SCA, we proposed exome sequencing of extreme phenotypes in a sample of the Brazilian population. Methods: Our sample consisted of 40 unrelated patients with SCA from the Hematology and Hemotherapy Center of the University of Campinas (Unicamp), Campinas, SP, Brazil. The cohort was composed by 20 patients who didn't have leg ulcer, with ages varying from 40 to 61 years (it is unusual the appearance of this disorder at such age) and 20 patients with chronic leg ulcer. DNA was collected from peripheral blood leukocytes and submitted to exome sequencing. Capture and enrichment were performed with the Nextera Rapid Capture Exome kit (Illumina) and samples were loaded in the Illumina HiSeq2500. The bioinformatics process was based on the GATK Pipeline and manual filters in vcftools and excel. Briefly, we prioritized the variants according to some conditions, like score quality, depth, Hardy-Weinberg equilibrium and minor allele frequency greater than 0.1. Subsequently, through PLINK, we selected the variants with p value less than 0.05 from Fisher association test. The annotation was made through wAnnovar. We excluded the synonymous variants, remaining with 244 variants at this point. Finally, the deleterious variants were selected, in addition to those not classified by SIFT, PolyPhen2 and FATHMM. Twenty-one variants remained, all of them in genes beyond the usual set of a priori biological candidate genes for this phenotype. We picked up 6 variants with the lowest p values: rs4857302 (CRYBG3), rs3782489 (KRT77), rs11800462 (TNFRSF25), rs13428956 (FOXD4L1), rs201853154 (UBTFL1) and rs11454536 (VWDE). We suggest that these variants and their genes could potentially be related to the development of leg ulcer in SCA. However, they should all be validated in other populations for confirmation.