Rotating biological contactors : a review on main factors affecting performance

Rotating biological contactors (RBCs) constitute a very unique and superior alternative for biodegradable matter and nitrogen removal on account of their feasibility, simplicity of design and operation, short start-up, low land area requirement, low energy consumption, low operating and maintenance cost and treatment efficiency. The present review of RBCs focus on parameters that affect performance like rotational speed, organic and hydraulic loading rates, retention time, biofilm support media, staging, temperature, influent wastewater characteristics, biofilm characteristics, dissolved oxygen levels, effluent and solids recirculation, stepfeeding and medium submergence. Some RBCs scale-up and design considerations, operational problems and comparison with other wastewater treatment systems are also reported.Fundação para a Ciência e a Tecnologia (FCT

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Origin of giant magnetoresistance in conventional AlNiCo5 magnets

Hütten A, Reiss G, Saikaly W, Thomas G. Origin of giant magnetoresistance in conventional AlNiCo5 magnets. ACTA MATERIALIA. 2001;49(5):827-835.Structure-property relationships in AlNiCo5 permanent magnets in the optimum magnetic state have been investigated so as to uncover the origin of giant magnetoresistance (GMR). According to analytical field ion and conventional transmission electron microscopy, AlNiCo5 consists of two coherent B2-ordered phases. One, alpha (1), corresponds to Fe7Co3 and the other, alpha (2), to Al1.1Ni0.9 with some substitution of Al, Ni, Cn and Fe, Co, Cu, respectively. Seventy percent of the GMR-effect can be attributed to superparamagnetic clusters, about 1 nm in size, positioned on the Al-rich alpha (2)-sublattice. The remaining 30% result from 3-6 nm superparamagnetic alpha (1)-clusters in the form of fine bridges interconnecting large alpha (1)-particles normal to, or inclined to their direction of elongation. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved

Segregation of Sn on migrating interfaces of ferrite recrystallisation: quantification through APT measurements and comparison with the solute drag theory

International audienceSolute atoms play an important role in grain boundary migration phenomena, which are critical for understanding the microstructural evolution in metals. Here we investigate the segregation of Sn at migrating boundaries during recrystallisation in a ferritic Fe-Si-Sn alloy using atom probe tomography. Experimental evidence demonstrated a solute depletion zone ahead of the moving interface. The behaviour of Sn was rationalized with the Cahn solute drag theory. A difference in segregation between two investigated migrating interfaces was observed and could be explained by a variation in either binding energy, intrinsic velocity of each interface or in driving force

The role of nano-segregation in the evolution of {411}<148> recrystallization texture in ferritic alloys

International audiencePolycrystalline metals undergo crystal rotations during thermomechanical processing. Rolling of bcc metals into sheets, gives rise to the so-called rolling textures, consisting of alpha and gamma fibers. Subsequent annealing and recrystallization generally have a softening effect on the texture intensity, however, texture memory from earlier material processing stages is evident. In low-carbon steels, the final texture typically consists of the {111} and {11h} fibers. Within the latter, a rather interesting feature of the recrystallization texture is the {411} texture component. This texture component is frequently observed in interstitial free (deep drawing applications) and electrical steels (magnetic flux carriers), yet the specifics of its origin and growth are not clear. Texture evolution can also be dramatically affected by alloying elements which tend to segregate on interfaces. In this study, we investigate the effect of Sn alloying in Fe-Si alloys and their static recrystallization behavior. To link crystallographic orientation preferences with chemical information, we use texture analysis with sequential electron back-scatter diffraction complemented with site-specific chemical analysis by atom probe tomography. High-stored energy nucleation of recrystallization is found to be greatly affected by Sn. An intriguing aspect of texture evolution with nano-segregation is that the recrystallization of the {411} texture component is considerably strengthened. The effect of Sn on the nucleation and growth aspects of this texture component is then discussed

The role of nano-segregation in the evolution of {411}<148> recrystallization texture in ferritic alloys

International audiencePolycrystalline metals undergo crystal rotations during thermomechanical processing. Rolling of bcc metals into sheets, gives rise to the so-called rolling textures, consisting of alpha and gamma fibers. Subsequent annealing and recrystallization generally have a softening effect on the texture intensity, however, texture memory from earlier material processing stages is evident. In low-carbon steels, the final texture typically consists of the {111} and {11h} fibers. Within the latter, a rather interesting feature of the recrystallization texture is the {411} texture component. This texture component is frequently observed in interstitial free (deep drawing applications) and electrical steels (magnetic flux carriers), yet the specifics of its origin and growth are not clear. Texture evolution can also be dramatically affected by alloying elements which tend to segregate on interfaces. In this study, we investigate the effect of Sn alloying in Fe-Si alloys and their static recrystallization behavior. To link crystallographic orientation preferences with chemical information, we use texture analysis with sequential electron back-scatter diffraction complemented with site-specific chemical analysis by atom probe tomography. High-stored energy nucleation of recrystallization is found to be greatly affected by Sn. An intriguing aspect of texture evolution with nano-segregation is that the recrystallization of the {411} texture component is considerably strengthened. The effect of Sn on the nucleation and growth aspects of this texture component is then discussed

Effect of the bainitic transformation temperature on retained austenite fraction and stability in Ti microalloyed TRIP steels

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Comparison of Sterculic Oil Induced Changes in the Gut Microbiota of Lean and Obese Mice

Recent obesity research has reported differences in intestinal microbiota between obese ob/ob mice and lean wild type mice suggesting a potential link between bacterial populations and metabolic health. Sterculic oil (SO) is a natural inhibitor of stearoyl-CoA desaturase-1, a potential therapeutic target for the treatment/attenuation of obesity and insulin resistance.The aim of this study was to investigate the response of the obese and lean gut microbiota to a SO supplemented diet. Five-week old male lean (WT) and obese (ob/ob) mice were fed either a control AIN-93G diet or an AIN-93G diet containing 0.5% SO for 9 weeks Barcoded pyrosequencing of the V4-V5 region of the 16S rRNA gene was employed to characterize cecal microbiota. Intestinal microbiota from WT mice fed a control diet were more diverse, although there were no significant differences in the proportions of major phyla from WT and ob/ob mice. Irrespective of genotype, SO was negatively correlated with the relative abundances of Actinobacteria, Bacilli and Erysipelotrichi. This shift was not associated with a change in body weight, however a statistically significant improvement in glucose tolerance and insulin sensitivity was observed in the ob/ob mice fed SO. In our study, diet had a greater impact on gut microbiota as compared to genotype and these changes were associated with an improved metabolic health

A methodology suitable for TEM local measurements of carbon concentration in retained austenite

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