171,763 research outputs found
cDNA clones of myeloperoxidase (MPO) and eosinophil peroxidase (EPO) from human blood mononuclear cells differentiated into granulocyte precursors in liquid cultures
No full textThe Reaction Behavior of Direct Reduced Iron (DRI) in Steelmaking Slags: Effect of DRI Carbon and Preheating Temperature
No full textAn experimental study was undertaken to quantify the rate of DRI decarburization in steelmaking slag using the constant–volume pressure increase technique. Experiments were conducted by dropping DRI pellets into molten slag at temperatures from 1500°C to 1600°C. Further experiments were carried out in which the DRI pellets were preheated while the slag temperature remained constant. The effect of initial carbon content and preheating temperature of the DRI on the reaction rate was investigated. The decarburization of DRI appears to comprise of two stages; reaction with the FeO of DRI, followed by further decarburization through the iron oxide of slag. Carbon has a significant effect on the kinetics of both stages while the preheating temperature mainly influences the rate of decarburization between FeO and carbon inside the pellet
The measurement of superoxide anion production by granulocytes In whole blood. A clinical test for the evaluation of phagocyte function and serum opsonic capacity
No full textThe paper reports a simple, sensitive and time-saving procedure for the assay of the function of the phagocytes on microsamples of whole blood. The method consists in the evaluation of the stimulation of superoxide anion (O-2) production (as superoxide dismutase-sensitive cytochrome c reduction) by leukocytes in whole blood challenged with (a) phagocytosable particles (opsonized zymosan); (b) particles that become phagocytosable by virtue of the opsonizing capacity of the plasma of blood samples (zymosan); and (c) a soluble agent such as phorbol myristate acetate. Preliminary studies indicate that this procedure can be used as a routine test because it enables information to be obtained about the respiratory responsiveness of phagocytes and about cellular and humoral defects of phagocytosis
Suburban forest patches have high functional and phylogenetic diversity in bird communities
No full textThe dataset contains necessary files to replicate the analyses in the article: Dri, G. F., Fontana, C. S., & de Sales Dambros, C. Suburban forest patches have high functional and phylogenetic diversity in bird communities. Currently under review
If additional comments or questions arise, please contact Gabriela Franzoi Dri ([email protected]) </p
A simultaneous assay for oxidative metabolism and adhesion of human neutrophils. Evidence for correlations and dissociations of the two responses.
No full textAn assay method for the simultaneous evaluation of the oxidative metabolism and adherence of human neutrophils is described, together with certain specific applications. Incubations were performed in serum-coated microtiter plates, where oxidative metabolism was measured as O2- release and, after washing out the nonadherent cells, the adhesion was measured as activity of acid phosphatase. Three agonists tested in this system--opsonized zymosan, concanavalin A, and N-formyl-methionyl-leucyl-phenylalanine--induced both activation of O2- release and cell adhesion, but the two functions had time course and dose dependence patterns that varied depending on the stimulant. Particularly with concanavalin A, O2- release and adhesion response were markedly dissociated; this lectin at low doses increased neutrophil adherence without triggering any O2- production, whereas at high doses it increased both O2- production and adherence. Anti-integrin monoclonal antibodies did not affect adhesion induced by low-dose concanavalin A but inhibited the adhesion induced by the other tested agonists. Adhesion and O2- production were also found to be differentially affected by the NADPH oxidase inhibitor diphenylene iodonium, the sulfhydryl reagent N-ethylmaleimide and the A2 agonist adenosine, indicating that these neutrophil responses have various transductional pathways that also depend on the type of stimulus
A Comparison Between the Reduction Behavior of DRI and BF Pellets in H2 and CO Atmospheres
No full textAbstract
The reduction behavior of two different iron ore pellets that are used in blast furnace (BF) and direct reduction (DRI) was investigated in this research. Single pellets reduction experiments were conducted isothermally using pure CO and H2 as reducing agent in the temperature range 700 °C to 1100 °C. Reduction by H2 was significantly faster than reduction by CO for both pellets and reduction rate increased with increasing the temperature. When CO was used as the reducing agent, the BF pellet achieved a reduction degree of 32% at 700 °C and 67% at 800 °C, while the DRI pellet reached 28% and 59% at the same temperatures. This difference is due to the lower magnetite content in BF pellets (1.93%) compared to DRI pellets (9.11%). However, at 1000 °C and 1100 °C, the DRI pellet achieved 93% and 100% reduction, and the BF pellet 88% and 94%, respectively, due to the higher porosity in the DRI pellet (38%) compared to BF (32%). Kinetics controlling model for hydrogen reduction of both pellets suggested as D2 (2D Diffusion through the solid ash), however, A1 (1D Nucleation and growth) and R3 (3D Chemical reaction) were found as the most compatible models for CO reduction of DRI and BF pellets, respectively.Abstract
The reduction behavior of two different iron ore pellets that are used in blast furnace (BF) and direct reduction (DRI) was investigated in this research. Single pellets reduction experiments were conducted isothermally using pure CO and H2 as reducing agent in the temperature range 700 °C to 1100 °C. Reduction by H2 was significantly faster than reduction by CO for both pellets and reduction rate increased with increasing the temperature. When CO was used as the reducing agent, the BF pellet achieved a reduction degree of 32% at 700 °C and 67% at 800 °C, while the DRI pellet reached 28% and 59% at the same temperatures. This difference is due to the lower magnetite content in BF pellets (1.93%) compared to DRI pellets (9.11%). However, at 1000 °C and 1100 °C, the DRI pellet achieved 93% and 100% reduction, and the BF pellet 88% and 94%, respectively, due to the higher porosity in the DRI pellet (38%) compared to BF (32%). Kinetics controlling model for hydrogen reduction of both pellets suggested as D2 (2D Diffusion through the solid ash), however, A1 (1D Nucleation and growth) and R3 (3D Chemical reaction) were found as the most compatible models for CO reduction of DRI and BF pellets, respectively
Possible mechanisms leading to DRI violation.
No full text<p>Left column shows development rates of three hypothetical life stages, early (blue dotted line), intermediate (orange dashed line) and late (green line), and the overall rate of development (thick grey); grey rectangles highlight the thermal range (<i>T</i><sub>1</sub>, <i>T</i><sub>2</sub>) in which the overall rate of development increases almost linearly with temperature; time units are omitted. Right column shows the corresponding relative duration of each stage in the (<i>T</i><sub>1</sub>, <i>T</i><sub>2</sub>) range. (a) DRI; (b) violation of DRI due to shifted, stage-dependent temperature optima; (c) violation of DRI due to progressively limiting, temperature-dependent metabolic scope for growth in individual stages; (d) violation of DRI due to limiting metabolic scope for growth in the intermediate stage. Even more severe DRI violation outside the (<i>T</i><sub>1</sub>, <i>T</i><sub>2</sub>) range in panels (b)–(d) is omitted for clarity. See text for further details.</p
Segnalazione di nuove macroalghe per la Laguna di Venezia
No full textThe authors report on the occurence in the lagoon of Venice of three Rhodophyta Agardhiella subulata (C.
Agardh) Kraft & Wynne, Solieria filiformis (Kützing) Gabrielson e Dipterosiphonia rigens (Schousboe) Falkenberg
and one Chlorophyta, Tellamia sp. new for the Lagoon of Venice. A brief description for each species is provided
Role of Heat Transfer in Early Stage Decarburization of DRI in Slag
No full textThe gas generation due to reactions between Direct Reduced Iron (DRI) pellets and steelmaking slags is known to take place in two stages; reaction of FeO and carbon within DRI, i.e. pellet internal reaction, followed by reduction of slag FeO with DRI carbon at the pellet–slag interface, if any carbon remains from the first step. In order to understand the controlling mechanism of reaction between FeO and C inside DRI, the rate of gas release and the temperature of pellets suspended in a slag–free atmosphere were quantified. The results were used to determine the apparent thermal conductivity of DRI that showed values around 0.5–2 W.m-1.K-1 for a temperature range of 573–1273 K. Further, it was found that the experimental gas evolution rates are consistent with the values predicted by a heat–transfer based model, confirming that the FeO–C reaction within pellet is controlled by the rate of heat transfer from slag to the DRI pellet
Brevi note su alcuni ritrovamenti algali per la laguna di venezia
No full textThe authors report on the occurrence in the Lagoon of Venice of three Rhodophyta, Aglaothamnion tripinnatum (C. Agatdh) Feldmann-Mazoyer, Hidrolithon boreale (Foslie) Y.M. Chamberlain and Lomentaria hakodatensis Yendo, one Chlorophyta, Prasiola crispa (Lightfood) Kutzing and one Crysophyta, Vaucheria piloboloides Thuret, new for the Lagoon of Venice or for the Italian coasts. A brief description for each species is provided
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