A Numercial Comparison of Single-phase Forced Convective Heat Transfer Between Round Tube and Round Microchannel Heat Exchangers

Abstract: Three dimensional simulations of the single-phase laminar flow and forced convective heat transfer of water in round tube and round microchannel heat exchangers were investigated numerically. This numerical method was developed to measure heat transfer parameters of round tube and round microchannel tube geometries. Then, similarities and differences were compared between different geometries. The geometries and operating conditions of those indicated heat exchangers were created using a finite volume-based computational fluid dynamics technique. In this article, at each Z-location variation of dimensionless local temperature, non-dimensional local heat flux variation and dimensionless local Nusselt number distribution along the tube length were compared between round tube and round microchannel heat exchangers. Consequently, averaged computational Nusselt number was obtained for those indicated models and then validation study was performed for round tube counter flow type heat exchanger model. Finally, all of these numerical results for both kind of geometries in counter flow heat exchangers were discussed in details

Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age.

The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.

Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age

Abstract The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset – with data collected between 2020 and 2022 – to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research

Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age

The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research

Numerical simulation of wave generation in a tank by wall and floor oscillation

Tsunamis occur every year in different seas and oceans around the world. These waves propagate at high speeds in various directions and, if they reach the shore, cause irreparable damage to these areas and their structures and facilities. Therefore, understanding this complex phenomenon and predicting its behavior can reduce the damages. In the present study, numerical simulation studies of the tsunami phenomenon were carried out. The purpose of the study was to predict the tsunami wave characteristics when reaching the coastal area. The use of numerical simulation greatly reduces the cost of laboratory work and can also be used for complex geometries and models. The tsunami waves were considered as viscous fluid by Navier-Stokes equations for shallow water as governing equations with fluid volume fractionation method for simulating water surface in software. Wave generation was created by simulating a tank that fluctuates once to its left wall and once to its bottom. This work was carried out by Fluent software. In the following, the influence of shaking side wall angles on the generated waves is investigated. The simulation results show a significant increase in wave height due to the oscillating wall angle. The effects of the oscillating bottom wall have also been studied. In this thesis, the method of producing and propagating tsunami waves is described and the equations are defined. Also, since the most important issue in dealing with this phenomenon is their control, a method for controlling tsunami waves is presented in this thesis. Finally, a multi-phase method is used to simulate the movement of waves in a tank with a tremor wall. Finally, the obtained results have been compared to the analytical results by Green equation method and there are good agreements between them. The results showed that there is no change in wave height at distant points and with the oblique wall obliquity being increased by 30 degrees, the wave production increases. In addition, the flow and pressure lines also become almost horizontal