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Wall-modeled large eddy simulation (LES) is a practical tool for solving wall-bounded flows with less computational cost by avoiding the explicit resolution of the near-wall region. However, its use is limited in flows that have high non-equilibrium effects like separation or transition. This study aims to present a novel methodology of using high-fidelity data and machine learning (ML) techniques to capture these non-equilibrium effects.

A precursor to this methodology has already been tested in Radhakrishnan et al. (2021) for equilibrium flows using LES of channel flow data. In the current methodology, the high-fidelity data chosen for training includes direct numerical simulation of a double diffuser that has strong non-equilibrium flow regions, and LES of a channel flow. The ultimate purpose of the model is to distinguish between equilibrium and non-equilibrium regions, and to provide the appropriate wall shear stress. The ML system used for this study is gradient-boosted regression trees.

The authors show that the model can be trained to make accurate predictions for both equilibrium and non-equilibrium boundary layers. In example, the authors find that the model is very effective for corner flows and flows that involve relaminarization, while performing rather ineffectively at recirculation regions.

Data from relaminarization regions help the model to better understand such phenomenon and to provide an appropriate boundary condition based on that. This motivates the authors to continue the research in this direction by adding more non-equilibrium phenomena to the training data to capture recirculation as well.

Green walls are vertical structures with various plant species that contribute to achieving sustainability in terms of environmental, economic and social aspects. A comparison of green wall performance with a similar type of conventional wall would be the most convincing way of promoting green wall applications than comparing the performance within types of green walls. Hence, this study evaluated the life cycle cost (LCC) of an indirect green facade with a conventional wall in the Sri Lankan tropical climate towards enhancing the adaptation of the green wall concept as an energy-saving solution.

The study involved two stages: (1) assessing the thermal performance and (2) calculating the LCC of the indirect green facade and the conventional wall. On-site temperature measurements were taken from various spots on the exterior and interior wall surfaces of each building in different time intervals per day for 21 days from the end of May to the beginning of July. The LCC analysis was performed using the cost data collected through the market survey and document review.

The temperature difference between the external and internal wall surfaces of the conventional wall (1.06⁰C) is higher than the green wall (0.32⁰C). This implies that green walls help retain 2/3 of the temperature transferred through a conventional wall, thereby reducing the energy requirement for cooling purposes by 70%. Though the initial cost of a green wall is 19% higher than a conventional wall, maintenance costs of green walls result in 29% savings. This results in a 55% overall annual LCC savings compared to conventional walls.

There is a dearth of studies to evidence that the cost performance of green walls is more effective than conventional walls in tropical climates, and this study fulfils this research gap. Thus, the findings would be more convincing to clients towards enhancing green wall applications.

This study aims to improve the stability and obstacle surmounting ability of the traditional wall-climbing robot on the surface of the ship, a wheel-track composite magnetic adsorption wall-climbing robot is proposed in this paper.

The robot adopts a front and rear obstacle-crossing mechanism to achieve a smooth crossover. The robot is composed of two passive obstacle-crossing mechanisms and a frame, which is composed of two obstacle-crossing magnetic wheels and a set of tracks. The obstacle-crossing is realized by the telescopic expansion of the obstacle-crossing mechanism. Three static failure models are established to determine the minimum adsorption force for the robot to achieve stable motion. The Halbach array is used to construct the track magnetic circuit, and the influence of gap, contact area and magnet thickness on the adsorption force is analyzed by parameter simulation.

The prototype was designed and manufactured by the authors for static failure and obstacle crossing tests. The prototype test results show that the robot can cross the obstacle of 10 mm height under the condition of 20 kg load.

A new structure of wall-climbing robot is proposed and verified. According to the test results, the wall-climbing robot can stably climb over the obstacle of 10 mm height under the condition of 20 kg load, which provides a new idea for future robot design.

Does the history of the bureaucratic system, along with the establishment of the Great Wall during the Ming and Qing dynasties (1368–1911), affect firm behavior across the borderlands of the Great Wall?

The Ming and Qing dynasties built a centralized administrative system in the borderlands on the south side of the Great Wall, in contrast to the “feudal lordship” system on the north side. Employing a regression discontinuity analysis framework with the Great Wall as a geographical discontinuity, we examine the long-run effects of the Great Wall on firms’ earnings management.

Using a large sample of nonlisted firms in the central core frontier region, we show that the earnings management of firms in the region south of the Great Wall is significantly curtailed compared with firms in the north of it, and this effect is more pronounced for non-SOEs. Our findings are robust to a battery of tests to account for alternative explanations.

Overall, by emphasizing the role of institutions, like legal system, shaped in history on firms’ earnings management, this study sheds new light on institutional determinants of firms’ behaviors in earnings information disclosure.

First, we enrich our understanding of the institutional determinants of firms’ financial reporting outcomes. Second, our findings shed new light on the long-term effects of historical ruling styles on modern corporate behavior.

The purpose of this paper is to present a frequency domain analysis of high frequency behaviour of an indoor Powerline communications (PLC) circuit in the presence of a plaster board/concrete wall structure. The main purpose of this analysis is to investigate the influence of the wall structure on the current distribution and the radiated electric field due to PLC signals in range from 3 MHz to 30 MHz.

The mathematical model is based on the full‐wave theory formulated by the Mixed Potential Integral Equation (MPIE) for the electric field due to energized thin‐wire conductors in stratified media. The solution for the current and the electric field distribution is obtained by using the Method of Moments.

Numerical results are obtained of the current distribution along the conductors of the PLC circuit and the radiated electric field in presence of a wall structure. Two cases are analyzed: when the circuitry is placed in the wall; and when the circuitry is placed outside the wall.

The paper presents the mathematical model that may be applied for analysis of indoor PLC circuits placed in presence of wall structures.

In the paper, a full‐wave model of the PLC circuitry in presence of a wall structure is developed, on the basis of MPIE and the Method of Moments.

This paper aims to focus on linear and non-linear convection in a lid-driven square cavity with isothermal and non-isothermal bottom surface.

It is assumed that the top moving wall is adiabatic and the bottom wall is heated in two modes, and the rest of the walls are maintained at uniform cold temperature. The coupled governing non-linear partial differential equations are solved numerically with MAC algorithm for conducting a parametric study with uniform and non-uniform temperature bottom wall.

The numerical results are depicted in the form of streamlines, temperature contours and variation of local Nusselt number. The local Nusselt number at the bottom wall of the cavity increases in presence of non-linear temperature parameter as compared with linear temperature parameter and heat transfer reduces with increasing of Ha for uniform and non-uniform heating of bottom wall.

The numerical investigation is conducted for unsteady, two-dimensional natural convective flow in a square cavity. An extension of the present study with the effect of inclination of cavity, wavy walls and triangular cavity will be the interest of future work.

This work studies the effect of magnetic field in the presence of linear convection and non-linear convection. This study might be useful to cooling of electronic components, alloy casting, crystal growth and fusion reactors, etc.

Tile finishes are very commonly used in external walls of buildings. However, the ageing process of the tile system is very seldom studied, which makes maintenance scheduling on external wall finishes impossible. The paper aims to contend that weathering exposure is one of the main accelerators of delamination. This paper seeks to test empirically the effects of orientation and shading on the probability of wall tile delamination.

This paper analyses the weathering effects, including orientation and shading, on thepercentage of deliminated areas of the external wall tiles by regression in a large estate in Hong Kong. Wall tile delamination data are collected from ten blocks of a high‐rise housing estate in Hong Kong, multiple linear regression is used to analyse the effects of orientation and shading on the probability of failure of the wall tiling systems.

The results of this paper indicate the effects of orientation and shading on the proportion of delamination of the external wall tile finishes.

The results agree with our contention that shaded areas are found to have lower rate of delamination, while north‐west and exposed façades are found with serious delamination. The results have great implications on maintenance scheduling for external wall tile finishes. Exposed areas receiving intensive thermal and moisture cycles are found to have significantly higher probability of failure. The study is limited by the small number of samples.

The results provide a set of data on the probability of failure of external wall tiling systems, for further ageing and durability analyses of external wall tiling systems. The findings are also of importance to designers and property managers for choosing external wall finishes and shading devices; and for maintaining external wall tile finishes.

This paper is the first study on the probability of failure and weathering impacts on external wall tiling systems. It is also the first attempt to achieve the objectives by means of empirical evidence.

City wall is an important symbol of ancient Chinese cities with unique geographical and cultural characteristics. Thus, the preservation of this historic landmark is considered significantly important. However, numerous residential construction activities and changes in ecological environment have destructed a great portion of the city walls in recent years. This study looks into the preservation of the ancient city walls from the systematic perspective and in line with the actual characteristics of Longdong Region to provide guideline measures for the protection and restoration of such landmark. Cognition and preservation are adopted extensively to investigate the specific situation of and the factors that influence the ancient city walls in this region. Preservation strategies for the city walls, including the “Axis-Point” system, planning control, and authenticity readability, are presented. The ancient city walls in Longdong Region can be preserved by protecting the entire region, the city, and the main wall body. The systematic method and preservation strategies at the “macro perspective,” “medium perspective” and “micro perspective” levels can solve the preservation problems of the ancient city walls in Longdong Region effectively.

The present investigation has been carried out in the framework of the numerical studies of the wall function influence on the calculation of wall shear stress. This shear stress is generated by the action of a normal plane impinging jet on a flat plate. The Navier‐Stokes, continuity and energy equations are solved for a two‐dimensional turbulent compressible flow by using the finite volume method. The standard k‐ε turbulence model is used as a closure model. To take into account the external shape influence of the nozzle, a quasi‐orthogonal curvilinear mesh is used. For a suitable calculation of the wall shear stress, the classical logarithmic wall law and its generalized form are used. The results of these calculations depend on the near wall grid. Therefore, this influence of near wall grid is studied more specifically here. A hybrid wall law is proposed, which results from the simultaneous use of the classical logarithmic wall law and the generalized one. This hybrid law gives suitable shear stress distributions with less dependence on the near wall grid. The calculations are validated through experimental data.

The Qingcheng County, where the ancient city wall is located, has rich regional cultural heritage. This ancient city wall is an important symbol for exhibiting the regional historical culture of Qingcheng. However, urban expansionary construction activities, environment chaos, and other issues have led to the destruction of the main part of the Qingcheng Ancient City Wall. Previous strategies for historical and cultural heritage Preservation planning emphasize rigidity and disregard resilience in protecting cultural heritage and the environment. On the basis of an analysis of the built environment of the Qingcheng Ancient City Wall, this study gains insights into the three aspects, namely, land use, road traffic, and municipal and disaster prevention in frastructure of the old city proper where the ancient city wall is located. A planning strategy that integrates an ordered control of land development, highly efficient and compound road traffic, synergetic municipal administration, and sound disaster-preventing infrastructure is formed according to cognitive results.