Influence of Exposure Temperature on Degradation of Magnesia Refractory by Steel Refining Slags

2019 ◽  
Vol 25 (5) ◽  
pp. 1360-1365 ◽  
Author(s):  
Jin Sung Han ◽  
Yongsug Chung ◽  
Joo Hyun Park
Keyword(s):  
Magnesia Refractory ◽  
Exposure Temperature ◽  
Steel Refining

Changes in Immunological Parameters and Disease Resistance in Juvenile Coho Salmon (Oncorhynchus kisutch) in Response to Dehydroabietic Acid Exposure under Varying Thermal Conditions

2004 ◽  
Vol 39 (3) ◽  
pp. 175-182 ◽  
Author(s):  
Keith B. Tierney ◽  
Eric Stockner ◽  
Christopher J. Kennedy
Keyword(s):  
Coho Salmon ◽  
Thermal Conditions ◽  
Dehydroabietic Acid ◽  
Aeromonas Salmonicida ◽  
Acclimation Temperature ◽  
Dependent Manner ◽  
Immunological Parameters ◽  
Cold Temperatures ◽  
Temperature Shock ◽  
Exposure Temperature

Abstract This study explored the effects of a sublethal 96-h dehydroabietic acid (DHAA) exposure on aspects of the immune system of juvenile coho salmon under varying temperature conditions. Coho were exposed to DHAA concentrations below the determined LC50 value of 0.94 mg/L (95% confidence limits of 0.81 to 1.24 mg/L) for 96 h at either their acclimation temperature (8 or 18°C), or during an acute warm-shock (8 to 18°C) or cold-shock (18 to 8°C). Acclimation temperature alone significantly affected hematocrit (Hct), neutrophil respiratory burst activity (RBA) and leucocyte proportions. With temperature-shock, leucocrit (Lct), RBA and leucocyte proportions were altered. All parameters were affected by DHAA exposure, but not always in a dose-dependent manner. Across groups, DHAA caused Hct, lysozyme, thrombocyte, neutrophil and monocyte proportions to increase, and Lct, RBA and lymphocyte proportions to decrease. DHAA-temperature interactions resulted in the exacerbation of DHAA-induced effects. Exposure temperature had the most significant effect on the susceptibility of coho to Aeromonas salmonicida; fish were more susceptible at cold temperatures and when subjected to a temperature-shock compared to their respective controls. DHAA exposure modulated the response of temperature-shocked fish to this pathogen.

scholarly journals Computational Investigation of Inclusion Removal in the Steel-Refining Ladle Process

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1048
Author(s):  
Xipeng Guo ◽  
Joel Godinez ◽  
Nicholas J. Walla ◽  
Armin K. Silaen ◽  
Helmut Oltmann ◽  
...  
Keyword(s):  
Multiphase Flow ◽  
Porous Plug ◽  
Cfd Modeling ◽  
Balance Model ◽  
Computational Investigation ◽  
Inclusion Removal ◽  
Inclusion Interaction ◽  
Computational Fluid Dynamics Cfd ◽  
Steel Refining ◽  
Transient Multiphase Flow

In a steel-refining ladle, the properties of manufactured steel can be notably degraded due to the presence of excessive inclusions. Stirring via gas injection through a porous plug is often used as part of the steel-refining process to reduce these inclusions. In this paper, 3D computational fluid dynamics (CFD) modeling is used to analyze transient multiphase flow and inclusion removal in a gas-stirred ladle. The effects of gas stirring with bubble-inclusion interaction are analyzed using the Euler–Euler approach for multiphase flow modeling, while the effects of inclusions aggregation and removal are modeled via a population balance model (PBM).

scholarly journals Effect of Elevated Temperature on Mechanical Properties of High-Volume Fly Ash-Based Geopolymer Concrete, Mortar and Paste Cured at Room Temperature

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1473
Author(s):  
Jun Zhao ◽  
Kang Wang ◽  
Shuaibin Wang ◽  
Zike Wang ◽  
Zhaohui Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
High Volume ◽  
Sem Analysis ◽  
Geopolymer Concrete ◽  
Ordinary Concrete ◽  
Exposure Temperature

This paper presents results from experimental work on mechanical properties of geopolymer concrete, mortar and paste prepared using fly ash and blended slag. Compressive strength, splitting tensile strength and flexural strength tests were conducted on large sets of geopolymer and ordinary concrete, mortar and paste after exposure to elevated temperatures. From Thermogravimetric analyzer (TGA), X-ray diffraction (XRD), Scanning electron microscope (SEM) test results, the geopolymer exhibits excellent resistance to elevated temperature. Compressive strengths of C30, C40 and C50 geopolymer concrete, mortar and paste show incremental improvement then followed by a gradual reduction, and finally reach a relatively consistent value with an increase in exposure temperature. The higher slag content in the geopolymer reduces residual strength and the lower exposure temperature corresponding to peak residual strength. Resistance to elevated temperature of C40 geopolymer concrete, mortar and paste is better than that of ordinary concrete, mortar and paste at the same grade. XRD, TGA and SEM analysis suggests that the heat resistance of C–S–H produced using slag is lower than that of sulphoaluminate gel (quartz and mullite, etc.) produced using fly ash. This facilitates degradation of C30, C40 and C50 geopolymer after exposure to elevated temperatures.

Simulation of Steel Refining Process in Converter

2010 ◽  
Vol 81 (8) ◽  
pp. 617-622 ◽  
Author(s):  
F. Pahlevani ◽  
S. Kitamura ◽  
H. Shibata ◽  
N. Maruoka
Keyword(s):  
Refining Process ◽  
Steel Refining

scholarly journals Oxidation Behavior of Ferritic Steel T22 Exposed to Supercritical Water

2019 ◽  
Vol 38 (2019) ◽  
pp. 476-484 ◽  
Author(s):  
Zhongliang Zhu ◽  
Hasan Izhar Khan ◽  
Qi Cao ◽  
Naiqiang Zhang
Keyword(s):  
Iron Oxide ◽  
Supercritical Water ◽  
Layered Structure ◽  
Outer Layer ◽  
Ferritic Steel ◽  
Oxidation Behavior ◽  
Spinel Oxide ◽  
Initial Oxidation ◽  
Exposure Temperature ◽  
Oxidation Stage

AbstractThe oxidation tests of Ferritic Steel T22 exposed to supercritical water (SCW) at 540–620°C and 25 MPa was performed for up to 1000 h. The oxidation rate increased with increasing exposure temperature and time. Oxide films formed on T22 have a double-layered structure with an outer layer consisting of iron oxide and an inner layer consisting of spinel oxide. Numerous pores on the surface can be observed at the initial oxidation stage while they seemed to heal with increasing exposure time at 620°C. Cracks occurred along grain boundaries in the oxide scale when T22 exposed for 200 h at 620°C. The influence of time and temperature on the oxidation of Ferritic Steel T22 was discussed.

Effect of magnesia-alumina spinel precursor sol on the sintering property of fused magnesia refractory

2019 ◽  
Vol 45 (3) ◽  
pp. 3459-3464 ◽  
Author(s):  
Qingdong Hou ◽  
Xudong Luo ◽  
Zhipeng Xie ◽  
Di An ◽  
Xiaofang Zhang ◽  
...  
Keyword(s):  
Magnesia Refractory

Temperature Estimation and Life Prediction of Turbine Blades Using Post-Service Oxidation Measurements

1997 ◽  
Vol 119 (4) ◽  
pp. 922-929 ◽  
Author(s):  
V. P. Swaminathan ◽  
J. M. Allen ◽  
G. L. Touchton
Keyword(s):  
Turbine Blades ◽  
Life Assessment ◽  
Depth Of Penetration ◽  
Trailing Edge ◽  
Element Analysis ◽  
Temperature Estimation ◽  
Exposure Temperature ◽  
Cooling Hole ◽  
Surface Metal ◽  
Service Exposure

The depth of internal oxidation and nitridation from the surface of the 16 cooling holes in a first-stage turbine blade was measured by optical microscopy after 32,000 hours of service. Maximum depth of penetration was 15.5 mils (0.4 mm) at the trailing edge hole. An effort was made to predict hole surface metal temperatures based on these measurements using the Arrhenius relationship between time and temperature with depth of oxidation assumed to be parabolic with time. Reasonable correlations were obtained between finite element analysis results and temperature estimates based on the oxidation measurements. In the thickest part of the airfoil, where metal temperature is minimum, intergranular cracks up to 12.6 mils (0.32 mm) in depth were found at the surface of the cooling holes. Measurable oxidation attack was only one to two mils (0.025–0.050 mm). Based on an approximate elastic-relaxation-local inelastic stress analysis, it was calculated that inelastic local strains of over one percent occur at the points of cracking. No cracking was observed in the more heavily oxidized, lower stressed, hotter holes. However, cracking occurred in a trailing edge tip cooling hole when weld repair of the tip squealer was attempted, due to embrittlement and grain boundary oxidation from service exposure. Temperature estimates suitable for life assessment purposes using oxidation measurements appears to be a possible technique that should be further developed and validated.

scholarly journals Design and Testing of an Experimental Steam-Induced Burn Model in Rats

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Vlad Porumb ◽  
Alexandru Florentin Trandabăț ◽  
Cristina Terinte ◽  
Irina Draga Căruntu ◽  
Elena Porumb-Andrese ◽  
...  
Keyword(s):  
Automated System ◽  
Level Of Automation ◽  
Exposure Temperature ◽  
Degree Burn ◽  
Computer Controlled ◽  
The Difference ◽  
High Level ◽  
New Treatments ◽  
Experimental Burns ◽  
Second Degree

Background. Most of the current models for experimental burns pose difficulties in ensuring consistency and standardization.Aim of Study. We aimed to develop an automated, reproducible technique for experimental burns using steam-based heat transfer.Methods. The system developed for steam exposure was based on a novel, integrated, computer-controlled design. Three groups of rats were exposed to steam for 1, 3, and 7 seconds. The lesions were evaluated after 20 minutes, 48 hours, and 72 hours after burn induction.Results. One-second steam application produced a superficial second-degree burn; three-second application induced deep second-degree burn; and seven-second application led to a third-degree burn.Conclusion. The high level of automation of our integrated, computer-controlled system makes the difference between our system and other models, by ensuring the control of the duration of exposure, temperature, and pressure and eliminating as many potential human generated errors as possible. The automated system can accurately reproduce specific types of burns, according to histological assessment. This model could generate the reproducible data needed in the study of burn pathology and in order to assess new treatments.

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