scholarly journals Thermal distribution in forced movement of water in pipes, channels and along the flat wall

Food Industry ◽  
2019 ◽  
Vol 26 ◽  
pp. 133
Author(s):  
D. Sinat-Radchenko ◽  
N. Ivashchenko ◽  
S. Vasilenko
Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 491
Author(s):  
Alina E. Kozhukhova ◽  
Stephanus P. du Preez ◽  
Aleksander A. Malakhov ◽  
Dmitri G. Bessarabov

In this study, a Pt/anodized aluminum oxide (AAO) catalyst was prepared by the anodization of an Al alloy (Al6082, 97.5% Al), followed by the incorporation of Pt via an incipient wet impregnation method. Then, the Pt/AAO catalyst was evaluated for autocatalytic hydrogen recombination. The Pt/AAO catalyst’s morphological characteristics were determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average Pt particle size was determined to be 3.0 ± 0.6 nm. This Pt/AAO catalyst was tested for the combustion of lean hydrogen (0.5–4 vol% H2 in the air) in a recombiner section testing station. The thermal distribution throughout the catalytic surface was investigated at 3 vol% hydrogen (H2) using an infrared camera. The Al/AAO system had a high thermal conductivity, which prevents the formation of hotspots (areas where localized surface temperature is higher than an average temperature across the entire catalyst surface). In turn, the Pt stability was enhanced during catalytic hydrogen combustion (CHC). A temperature gradient over 70 mm of the Pt/AAO catalyst was 23 °C and 42 °C for catalysts with uniform and nonuniform (worst-case scenario) Pt distributions. The commercial computational fluid dynamics (CFD) code STAR-CCM+ was used to compare the experimentally observed and numerically simulated thermal distribution of the Pt/AAO catalyst. The effect of the initial H2 volume fraction on the combustion temperature and conversion of H2 was investigated. The activation energy for CHC on the Pt/AAO catalyst was 19.2 kJ/mol. Prolonged CHC was performed to assess the durability (reactive metal stability and catalytic activity) of the Pt/AAO catalyst. A stable combustion temperature of 162.8 ± 8.0 °C was maintained over 530 h of CHC. To confirm that Pt aggregation was avoided, the Pt particle size and distribution were determined by TEM before and after prolonged CHC.


2021 ◽  
pp. 030913252110303
Author(s):  
Bradley Hinger

Mobilities scholars have shown how injustices may arise from forced movement or stillness. However, with notable exceptions, these studies tend to collapse analyses of race into a simplistic binary of immobility as an inherent characteristic of non-white people and the possibility of movement as only granted to white people. In this article, I call for an expanded approach that is inclusive of both the controlling forces of white supremacy and life-affirming resistance against and despite these constraints. Drawing from Black studies and Black Geographies, I argue for a more unified Black mobilities research agenda.


iScience ◽  
2021 ◽  
Vol 24 (2) ◽  
pp. 102085
Author(s):  
Qinyuan Gui ◽  
Bin Fu ◽  
Yonglin He ◽  
Shanzhi Lyu ◽  
Yingchao Ma ◽  
...  

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 1100-1107
Author(s):  
Ghulam Rasool ◽  
Waqar A. Khan ◽  
Sardar Muhammad Bilal ◽  
Ilyas Khan

Abstract This research is mainly concerned with the characteristics of magnetohydrodynamics and Darcy–Forchheimer medium in nanofluid flow between two horizontal plates. A uniformly induced magnetic impact is involved at the direction normal to the lower plate. Darcy–Forchheimer medium is considered between the plates that allow the flow along horizontal axis with additional effects of porosity and friction. The features of Brownian diffusive motion and thermophoresis are disclosed. Governing problems are transformed into nonlinear ordinary problems using appropriate transformations. Numerical Runge–Kutta procedure is applied using MATLAB to solve the problems and acquire the data for velocity field, thermal distribution, and concentration distribution. Results have been plotted graphically. The outcomes indicate that higher viscosity results in decline in fluid flow. Thermal profile receives a decline for larger viscosity parameter; however, Brownian diffusion and thermophoresis appeared as enhancing factors for the said profile. Numerical data indicate that heat flux reduces for viscosity parameter. However, enhancement is observed in skin-friction for elevated values of porosity factor. Data of this paper are practically helpful in industrial and engineering applications of nanofluids.


2016 ◽  
Vol 1 (1) ◽  
pp. 5-30 ◽  
Author(s):  
Rita Kaur Dhamoon

AbstractIn settler societies like Canada, United States, and Australia, the bourgeoning discourse that frames colonial violence against Indigenous people as genocide has been controversial, specifically because there is much debate about the meaning and applicability of genocide. Through an analysis of the Canadian Museum for Human Rights, this paper analyzes what is revealed about settler colonialism in the nexus of difficult knowledge, curatorial decisions, and political debates about the label of genocide. I specifically examine competing definitions of genocide, the primacy of the Holocaust, the regulatory role of the settler state, and the limits of a human rights framework. My argument is that genocide debates related to Indigenous experiences operationalize a range of governing techniques that extend settler colonialism, even as Indigenous peoples confront existing hegemonies. These techniques include: interpretative denial; promoting an Oppression Olympics and a politics of distancing; regulating difference through state-based recognition and interference; and depoliticizing claims that overshadow continuing practices of assimilation, extermination, criminalization, containment, and forced movement of Indigenous peoples. By pinpointing these techniques, this paper seeks to build on Indigenous critiques of colonialism, challenge settler national narratives of peaceful and lawful origins, and foster ways to build more just relations between Indigenous and non-Indigenous peoples.


1989 ◽  
Author(s):  
Naohito Katsura ◽  
Masahiro Saito ◽  
Jiro Senda ◽  
Hajime Fujimoto
Keyword(s):  

1998 ◽  
Vol 43 (12) ◽  
pp. 3519-3534 ◽  
Author(s):  
John C Rewcastle ◽  
George A Sandison ◽  
Leszek J Hahn ◽  
John C Saliken ◽  
J Gregory McKinnon ◽  
...  

2013 ◽  
Vol 702 ◽  
pp. 159-164
Author(s):  
Tomasz Wróbel

In paper problem concerning inoculation of primary structure of aluminum with purity of 99,5% and 99,8%, which is realized mainly by intensification of liquid metal movement in mould is presented. In aim of realization of forced movement during the crystallization of liquid metal was used rotating electromagnetic field produced by the induction coil supplied by current with elevated frequency. The degree of structure refinement was represented by equiaxed crystals zone content on transverse section of ingot and average area of macro-grain in this zone. Effect of structure refinement obtained by influence of electromagnetic field was compared with refinement obtained by use of traditional inoculation, which consists in introducing of additives i.e. titanium, boron and carbon to metal bath. The results of studies and their analysis show possibility of effective refinement of pure Al primary structure, only with use of rotating electromagnetic field and without necessity of application of inoculants such a Ti, B and C. This method of inoculation is important, because inoculants decrease the degree of purity and electrical conductivity of pure Al. Moreover Ti and B are reason of point cracks formation during rolling of ingots.


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