scholarly journals Surface Texture Modification for Improved Roping Behaviour of Aluminium Alloy 6016

2010 ◽  
Vol 160 ◽  
pp. 197-202
Author(s):  
Tricia A. Bennett ◽  
Roumen H. Petrov ◽  
Leo Kestens
Keyword(s):  
Aluminium Alloy ◽  
Uniform Distribution ◽  
Surface Texture ◽  
Significant Interaction ◽  
Slow Heating ◽  
Intermediate Annealing ◽  
Fast Heating ◽  
Annealed Material ◽  
Texture Modification

The effect of two different intermediate annealing (IA) treatments on texture banding in a roping prone aluminium alloy was investigated. It was found that texture banding occurred in the final annealed material that underwent an IA treatment consisting of slow heating in which there was significant interaction between the recrystallizing grains and the particles in the material. A more uniform distribution of orientations in the final annealed material was obtained in the case of an IA treatment with fast heating so that there was no significant effect of particles on recrystallization.

Antibiofilm properties of model composites containing quaternary ammonium methacrylates after surface texture modification

2017 ◽  
Vol 33 (10) ◽  
pp. 1149-1156 ◽  
Author(s):  
Guilherme Ferreira Rego ◽  
Marina Lermen Vidal ◽  
Gil Mendes Viana ◽  
Lucio Mendes Cabral ◽  
Luis Felipe Jochims Schneider ◽  
...  
Keyword(s):  
Surface Texture ◽  
Quaternary Ammonium ◽  
Texture Modification

Study on the residual performance of RC beams exposed to processed temperatures and fire

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sachin Vijaya Kumar ◽  
N. Suresh
Keyword(s):  
Failure Modes ◽  
Elevated Temperatures ◽  
Slow Heating ◽  
Maximum Temperature ◽  
Rc Beams ◽  
Heating Rates ◽  
Fast Heating ◽  
Content Type ◽  
Temperature Increment ◽  
Residual Performance

PurposeThe Reinforced Concrete(RC) elements are known to perform well during exposure to elevated temperatures. Hence, RC elements are widely used to resist the extreme heat developing from accidental fires and other industrial processes. In both of the scenarios, the RC element is exposed to elevated temperatures. However, the primary differences between the fire and processed temperatures are the rate of temperature increase, mode of exposure and exposure durations. In order to determine the effect of two heating modalities, RC beams were exposed to processed temperatures with slow heating rates and fire with fast heating rates.Design/methodology/approachIn the present study, RC beam specimens were exposed to 200 °C, to 800 °C temperature at 200 °C intervals for 2 h' duration by adopting two heating modes; Fire and processed temperatures. An electrical furnace with low-temperature increment and a fire furnace with standard time-temperature increment is adapted to expose the RC elements to elevated temperatures.FindingsIt is observed from test results that, the reduction in load-carrying capacity, first crack load, and thermal crack widths of RC beams exposed to 200 °C, and 600 °C temperature at fire is significantly high from the RC beams exposed to the processed temperature having the same maximum temperature. As the exposure temperature increases to 800 °C, the performance of RC beams at all heating modes becomes approximately equal.Originality/valueIn this work, residual performance, and failure modes of RC beams exposed to elevated temperatures were achieved through two different heating modes are presented.

Temperature-Programmed Oxidation Experiments on Typical Bituminous Coal Under Inert Conditions

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Yansong Zhang ◽  
Houwang Wang ◽  
Wenzhou Du ◽  
Kuo Niu ◽  
Xiangrui Wei
Keyword(s):  
Bituminous Coal ◽  
Co2 Concentration ◽  
Inert Gases ◽  
Slow Heating ◽  
Fast Heating ◽  
Temperature Programmed Oxidation ◽  
Heating Stage ◽  
Temperature Programmed ◽  
Residual Coal ◽  
Two Stages

Abstract In this study, an experimental investigation was presented on the oxidation behaviors of bituminous coal for different inert gases (N2 and CO2) at different concentrations (oxygen concentration indexes 21%, 18.4%, 15.8%, and 13.1%) using a temperature-programmed experimental device. The purpose of this research was to examine the oxidation patterns of bituminous coal under different inert conditions. The results showed that: (1) the oxidative heating of the coal underwent two stages: an initial slow heating stage and a fast heating stage. The injection of both inert gases would result in a delay in the crossing point temperature (CPT) of the coal, but the injection of N2 resulted in greater delays in the CPT of the coal; (2) the injection of both N2 and CO2 inhibited the concentrations of CO and alkane/olefin gases produced from the oxidative heating of the coal, with CO2 displaying higher inhibition efficiencies than that of N2; (3) Under a non-inerting environment, the C2H4 and C2H6 generation temperatures were 110 °C and 100 °C. Under an inerting environment, when N2 was injected, the higher the N2 concentration, the higher the initial C2H4 and C2H6 generation temperatures; when CO2 was injected, the higher the CO2 concentration, the lower the initial C2H4 and C2H6 generation temperatures; and (4) under a non-inerting environment, the C3H8 generation temperature was 90 °C; and when an inert gas was injected, there was a hysteresis in the C3H8 generation temperature for all concentrations. The above research results can be used to predict the spontaneous combustion of residual coal in an inert environment and prevent fires.

scholarly journals Influence of circulating cytokines on prolactin during slow vs. fast exertional heat stress followed by active or passive recovery

2012 ◽  
Vol 113 (4) ◽  
pp. 574-583 ◽  
Author(s):  
Heather E. Wright ◽  
Tom M. McLellan ◽  
Brian J. Friesen ◽  
Douglas J. Casa ◽  
Glen P. Kenny
Keyword(s):  
Heat Stress ◽  
Stress Responses ◽  
Cold Water ◽  
Water Immersion ◽  
Body Core Temperature ◽  
Slow Heating ◽  
Fast Heating ◽  
Subsequent Recovery ◽  
Tnf Α ◽  
Exertional Heat Stress

Prolactin (PRL) has been suggested as an indicator of fatigue during exertional heat stress (EHS), given its strong relationship with body core temperature (Tc); however, the strength of this relationship during different rates of Tc increase and subsequent recovery is unknown. In addition, given the influence that systemic cytokines, such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α, have on the pituitary gland, it would be of interest to determine the relationship between PRL, IL-6, and TNF-α during EHS. The purpose was to examine the PRL, IL-6, and TNF-α heat stress responses during slow and fast heating and subsequent resting or cold water immersion recovery. On 4 days, nine individuals walked at ∼45% (slow heating) or ran at ∼65% (fast heating) maximal oxygen consumption on a treadmill in the heat (40°C, 30% relative humidity) until rectal temperature (Tre) reached 39.5°C (esophageal temperature; fast = 39.41 ± 0.04°C, slow = 39.82 ± 0.09°C). Post-EHS, subjects were either immersed in 2°C water or rested seated until Tre returned to 38.0°C. Venous blood, analyzed for PRL, IL-6, and TNF-α, was obtained at rest, during exercise (Tre 38.0, 39.0, 39.5°C), the start of recovery (∼5 min after 39.5°C), and subsequent recovery (Tre 39.0, 38.0°C). IL-6 exhibited myokine properties, given the greater increases with slow heating and lack of increase in TNF-α. A strong temperature-dependent PRL response during slow and fast heating provides additional support for the use of PRL as a peripheral marker of impending fatigue, which is independent of IL-6 and TNF-α cytokine responses.

Influence of the Blank Initial State on the Quality of the Small Drawn Parts

2013 ◽  
Vol 371 ◽  
pp. 710-714
Author(s):  
Elena Costache ◽  
Gheorghe Brabie ◽  
Augustin Jitaru
Keyword(s):  
Surface Roughness ◽  
Aluminium Alloy ◽  
Uniform Distribution ◽  
Drawing Process ◽  
Blank Holder Force ◽  
Initial State ◽  
Blank Holder ◽  
Part Quality ◽  
Negative Phenomena

An optimum blank quality presents the following several benefits on the drawn part quality: it leads to an improved quality of the parts; it prevents some negative phenomena (like: fracture, a uniform distribution of material thickness in the drawn part and reduction of the blank holder force required during the drawing process). In the present work, an analysis was performed concerning the influence of the initial state of blank (microhardness, thickness, surface roughness and topography) on the quality of micro/milli cylindrical drawn parts made from aluminium alloy sheets having the following thicknesses: 0.10 and 0.20 mm.

scholarly journals Pore Size Distribution and Microstructure of Oil Palm Shell Heat Treated at 300 C Followed by Slow or Fast Heating Treatment

2020 ◽  
Vol 9 (1) ◽  
pp. 15-25
Author(s):  
Joko Sulistyo ◽  
Toshimitsu Hata ◽  
Yuji Imamura ◽  
Purnomo Darmaji ◽  
Sri Nugroho Marsoem
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Oil Palm ◽  
Slow Heating ◽  
Fast Heating ◽  
Palm Shell ◽  
Oil Palm Shell ◽  
Heat Treated ◽  
Heating Treatment

Pore size distribution and microstructure development of oil palm shell heat treated at 300ºC and treated at 300ºC and recarbonization at 600ºC followed by slow- or fast heating treatment up to 700ºC were investigated by small angle X-ray scattering (SAXS), N2 gas adsorption and Raman spectroscopy. On oil palm shell heat-treated at 300ºC, slow heating treatment gave the widening micropore along with the ordering microstructure; but fast heating treatment produced charcoal with a narrow diameter of micropore with wider pore size distribution and the disordering microstructure. On oil palm shell heat treated at 300ºC and recarbonization at 600ºC, slow heating treatment contributed on the opening new micropore with ordering microstructure, but some parts of micropore showing inaccessible for N2 gas. Meanwhile, fast heating treatment with the heating rate from 75 to 250ºC/min increased BET surface area with similar pore size distribution and the disordering microstructure.

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