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PurposeThis study explores the role of external pressure, engagement capability (ENC), alliance capability (ACA), environmental sustainability commitment (ESC), and circular supply chain capability in circular economy performance.Design/methodology/approachThrough a cross-sectional survey and data collected from 124 small and medium enterprises (SMEs) in Ghana, this study employs partial least square structural equation modelling (PLS-SEM) to test the proposed model.FindingsThe findings reveal the following; first, external pressure has a significant impact on ESC. Second, ESC positively impacts ACA, ENC and circular supply chain capability. Third, ACA and ENC mediate the relationship between ESC and circular supply chain capability. Finally, circular supply chain capability has a significant impact on circular economy performance.Originality/valueThe originality of this study lies in testing a novel model that confirms that SMEs respond to external pressure by enhancing ESC as well as develop engagement and alliance capabilities to improve circular supply chain capability to achieve circular economy performance goals.

The present paper investigates the buckling behavior of grid-stiffened composite annular spherical shells with geodesic lattice cores subjected to external pressure, using analytical and numerical approaches. Using a smeared stiffener technique, the grid structure is transformed into an equivalent composite layer. To achieve the overall stiffness of the grid-stiffened shell, the stiffness of the stiffeners should be superimposed by the stiffness of the shells. The governing equations are formulated based on the classical Donnell’s thin shell theory. The Galerkin method has been applied to extract the buckling loads. To corroborate the analytical results, a finite element model is provided. The comparisons indicate satisfactory agreement between the two approaches. Moreover, the effect of meridian angle, stiffener orientation, and skin thickness are investigated. The results obtained are new and can be used for future studies.

Creep is an irreversible time-dependent deformation in which a material under constant mechanical stress and elevated temperature for a considerably prolonged period of time, starts to undergo permanent deformation. Creep deformation occurs in three stages namely, primary, secondary and tertiary. Out of these three stages, secondary or steady state creep is particularly an area of engineering interest as it has almost a constant creep rate. Creep deformation plays a significant role in understanding effective service life of an engineering component working under high temperature conditions as such components such as super-heater and re-heater tubes and headers in a boiler, jet engines operating at temperature as high as 1200 ∘C, usually experience a failure or rupture due to creep phenomenon. Design engineers keep a close attention on working stress conditions and elevated temperature under which an engineering component is expected to work as these conditions determine the onset of creep behavior in an engineering component. By recognizing the parameters of material response to creep behavior, engineers can analyse the useful service life and hazardous working conditions for an engineering components. Recognizing the creep phenomenon as high temperature design limitation, ASME Boiler and Pressure Vessel Code have provided guidelines on maximum allowable stresses for materials to be used in creep range. One of the criteria for determination of allowable stresses is 1% creep deformation of material in 100,000 h of service. Thus, the study of creep behavior in engineering components pertaining to high stress and temperature working conditions is very important as it affects the reliability and performance of the engineering components. The aim of our study is to understand the behavior of secondary creep deformation so that an advanced reinforced functionally graded material with better creep resistance, can be designed. In this paper, a secondary creep analysis of functionally graded (FG) thick-walled rotating cylinder under internal and external pressure is conducted. The novelty of the model intends to specify secondary creep stresses and strains by employing exponential, linear and quadratic volume reinforcement for SiCp ceramic in Al metal matrix in radial direction. This will help us to understand the effect of volume reinforcement in FG cylinder under internal/external pressure and rotating centrifugal body force by obtaining secondary creep stresses and strains. The response of the FG cylinder with isotropic material is analyzed and the solution for stress–strain rates in radial and tangential directions are obtained in closed form. Comparison of steady state creep stresses and strains under exponential, linear and quadratic volume reinforcement profiles are discussed and presented graphically.

This research investigates fraudulent financial reporting in non-financial companies listed on the IDX from 2018 to 2021. Statistical Product and Service Solution software version 17 is used in this study to conduct multiple linear regression analysis and moderated regression on data from 360 organizations. Research This demonstrates that financial targets, financial stability, and rationalization all have a beneficial effect on fraudulent financial reporting, however industry type and director change have no meaningful effect. The audit committee modifies the impact of external pressure and rationalization on fraudulent financial reporting, but has no affect on financial targets, stability, poor supervision, auditor turnover, industry type, or director change. T tests regularly reveal that certain variables, such as industry structure, director turnover, and audit committee oversight, have no significant effect on false financial reporting. These findings call into question conventional assumptions and provide useful insights into detecting and preventing financial fraud. This study specifically questions the agency hypothesis, which says that independent audit committees do not always decrease fraud in financial reporting. This new contribution invites a reassessment of audit committees' role and efficacy in combatting financial fraud, adding depth to previous research in this area.

Wrinkling is a significant challenge associated with the forming of tubes via diameter reduction. The work reported herein employed elastoplastic principles to assess the external pressure diameter reduction forming process by generating a strain diagram showing the occurrence of critical instability. This diagram can be used to effectively predict the appearance of wrinkling defects during forming. The Donnell linear buckling theory together with a bilinear material model was used to derive an expression for the critical external pressure leading to wrinkling instability, employing constant tube end conditions and a uniform external pressure, and the effects of forming conditions and material parameters on wrinkling were explored. During experimental trials, AA6061 tubes were formed via diameter reduction in conjunction with varying heat treatment conditions using the solid granule medium forming process. A Vialux portable mesh strain tester was employed to collect relevant data to verify the critical instability points, and the effects of various factors on resistance to wrinkling were investigated. An analysis of the experimental results demonstrates that the conclusions of the theoretical analysis are correct.

To date, with the increasing attention of countries to urban drainage system, more and more regions around the world have begun to build water conveyance tunnels, sewage pressure deep tunnels and so on. However, the sufficient bearing capacity and corrosion resistance of the structure, which can ensure the actual service life and safety of the tunnel, remain to be further improved. Glass Fiber Reinforced Plastics (GFRP) pipe, with light weight, high strength and corrosion resistance, has the potential to be applied to the deep tunnel structure. This paper proposed a new composite structure of deep tunnel lined with GFRP pipe, which consisted of three layers of concrete segment, cement paste and GFRP pipe. A new pipe-soil spring element model was proposed for the pipesoil interaction with gaps. Based on the C3D8R solid model and the Combin39 spring model, the finite element numerical analysis of the internal pressure status and external pressure stability of the structure was carried out. Combined with the checking calculation of the theoretical formula, the reliability of the two finite element models was confirmed. A set of numerical analysis methods for the design and optimization of the three-layer structure was established. The results showed that from the internal GFRP pipe to the outer concrete pipe, the pressure decreased from 0.5 to 0.32 MPa, due to the internal pressure was mainly undertaken by the inner GFRP pipe. The allowable buckling pressure of GFRP pipe under the cover of 5 GPa high modulus cement paste was 2.66 MPa. The application of GFRP pipe not only improves the overall performance of the deep tunnel structure but also improves the construction quality and safety. The three-layer structure built in this work is safe and economical.

Thin-walled cylindrical shells are widely used as silos, liquid tanks, marine structures, and industrial chemical plants. In such applications, the shells are mostly exposed to liquids. Corrosion occurs on surfaces when shells are filled with low-pH liquids. Corroded material loss decreases the thickness of the shells which in turn lessens their buckling capacity. The current study primarily aims to investigate the effects of corrosion on the buckling capacity of thin-walled cylindrical shells subjected to uniform external pressure. The model shells were half- or full-filled with 5% and 10% HCl (Hydrochloric Acid) solutions for corrosion. In order to attenuate the negative effects of corrosion, the cylinders were coated with varying sizes of Carbon Fiber-Reinforced Polymer (CFRP) sheets. A total of 12 models of 800 x 400 x 0.45 mm in dimension were investigated in this research. The perfect non-corroded models were employed to compare the behavior of all models under study. The obtained results indicated that corrosion would cause a significant decrease in the buckling capacity of thin-walled cylindrical shells. It should be noted that the acid ratio, filling rate, and surface area coated with CFRP fabrics considerably affected the buckling capacity of cylinders. To be specific, coating the cylinders with one layer of CFRP moderated the buckling capacity loss.

In order to solve the problem of the low treatment efficiency of wastewater containing heavy metals in mining areas, straw biochar and graphene oxide enhanced external pressure ultrafiltration (SGU) was used to treat wastewater containing high concentrations of Pb2+. The operation parameters such as pH and temperature were optimized, and the removal efficiency of CODCr, NH3-N, turbidity and Pb2+ via SGU, straw biochar ultrafiltration (SU), ultrafiltration (UF), and conventional treatment (CT) were systematically investigated. The results showed that the pH and temperature of polluted water were 4.8–5.2 and 21–30 °C, respectively, the average removal rates of CODCr, NH3-N, turbidity and Pb2+ by SGU reached 91%, 97%, 98% and 95%, respectively, and the removal effect was better than that of other processes. In addition, under the backwash conditions of clean water, weak acid, and weak alkali, the membrane flux recovered 65%, 88%, and 89% of the new membrane, respectively. This study provides scientific and theoretical support for the advanced treatment of polluted water in mining areas.

The design of a 69 m tall multipurpose building was investigated in this paper. The shape of the structure above the ground was an elliptical cylinder. Under the ground, the building was extended into a cuboid shape (for car parking). External wind pressure coefficients were determined using three methods: wind tunnel tests, CFD, and “the simplification of the shape” (using information defined in building standards). From the obtained results, it was evident that the simplification did not provide results with sufficient accuracy. The external wind pressure coefficients presented in this paper should be used for the design of a similar structure. The shape of the elliptical cylinder is very sensitive to applied wind. Positive pressures only occur on a small area of the windward side. The rest of the windward side is loaded with negative pressures. Therefore, torsional effects can occur, and these can be dangerous for the structure. The leeward side is completely loaded with negative pressures. In our case, this information was necessary for a follow-on static and dynamic analysis of the building. Various subsoil stiffness coefficients were considered. The calculated horizontal displacement was compared with the limit value. A measured wind direction of 20° caused the maximum obtained torsional moment, and a wind direction of 90° induced the maximum obtained force. The commercial program Ansys Fluent 2022 was used for the CFD simulation. The SCIA ENGINEER 21 program was used for follow-on analysis. This paper presents brief information on the selected turbulence model and details the settings used for the CFD simulation. Also, a description of the wind tunnel laboratory utilized in this study is provided, along with a description of the measuring devices used and the methodologies of the tests carried out. The main purpose of this paper is to show how important it is to consider the wind load for the static analysis of a structure like this.

This article deals with the investigation of wind effects on a façade of a rectangular residential building with explicit modelling of the windows for specific wind conditions. The external wind pressure coefficients were treated on the façade and at the places of the window sills, linings, and lintel for the direction of the wind from 0° to 90° with increments of 22.5°. For a detailed analysis, the CFD simulation using Ansys Fluent was used. The method selected for the CFD simulation solution and its setting (quality of meshing, horizontal homogeneity of the boundary layer, etc.) were verified by known results of similar objects. The purpose of this analysis is to show how important it is to consider wind effects to determine the suitable placement of passive ventilation devices. Research shows the potential optimal position of ventilation units in terms of favourable pressure distribution. Zones with negative pressure and corners or façades in a wake are not suitable for applying passive ventilation units. The results can serve as a basis for designers to achieve optimal comfort in residential buildings.