Search Results (656)

The Middle Eastern construction industry significantly contributes to regional economic development but faces persistent sustainability challenges due to logistical inefficiencies. This study aims to address the gap in the existing literature, which often treats logistics challenges, solutions, and critical success factors (CSFs) in isolation without offering a unified framework to integrate these elements. By leveraging structural equation modelling (SEM), this research provides a comprehensive approach to understanding and addressing the interconnections between logistics inefficiencies, proposed solutions, and sustainability outcomes. Using SEM, this study identifies and analyses 23 logistics challenges, 18 solutions, and 8 CSFs, revealing their relationships and collective impact on sustainability in the construction sector. SEM’s robust analytical capabilities enable simultaneous testing of complex interdependencies, offering insights that traditional methodologies cannot achieve. The findings emphasise the critical role of lean methodologies, advanced technologies, and collaboration strategies in overcoming inefficiencies, reducing environmental impact, and optimising resource use. This research fills a crucial gap by developing a cohesive framework that integrates logistics challenges, solutions, and CSFs to advance sustainable practices. The outcomes provide actionable guidance for stakeholders to improve sustainability performance while enhancing competitiveness in Middle Eastern construction logistics Full article

Due to Paleo-clay’s unique properties and widespread distribution throughout China, it is essential in geotechnical engineering. Rainfall frequently causes the deformation of Paleo-clay slopes, making slope instability prediction crucial for disaster prevention. This study explored Paleo-clay’s strength degradation and slope stability under soaking and wet–dry cycles. Using Mohr–Coulomb failure envelopes from experiments, curve fitting was used to find the patterns of Paleo-clay strength degradation. Finite element simulations and the strength discounting method were used to analyze the stability and deformation of Paleo-clay slopes. The results indicate that wet–dry cycles impact them more than soaking. Paleo-clay’s cohesion decreases exponentially as the number of wet–dry cycles and soaking times rise, but the internal friction angle changes very little. After 10 wet–dry cycles and 24 days of soaking, iron-bearing clay’s cohesion decreased to 17% and 44% and reticular clay’s to 32% and 48%. Based on the study area characteristics, three slope types were constructed. Their stability exhibited exponential decay. Under soaking, stability remained above 1.4; under wet–dry cycles, type I and II stability fell below 1.0, leading to deformation and failure. All types showed traction landslides with sliding zones transitioning from deep to shallow. Practical engineering should focus on the shallow failures of Paleo-clay slopes. Full article

Urban expansion encroaches on green spaces and weakens ecosystem services, potentially leading to a trade-off between ecological conditions and socio-economic growth. Effectively coordinating the two elements is essential for achieving sustainable development goals at the urban scale. However, few studies have measured urban–ecological linkage in terms of trade-off. In this study, we propose a framework by linking the degraded ecological conditions and urban land use efficiency from a return on investment perspective. Taking a rapidly expanding city as a case study, we comprehensively quantified urban–ecological conditions in four aspects: urban heat island, flood regulating service, habitat quality, and carbon sequestration. These conditions were assessed on 1 km² grids, along with urban land use efficiency at the same spatial scale. We employed the slack-based measure model to evaluate trade-off efficiency and applied the geo-detector method to identify its driving factors. Our findings reveal that while urban–ecological conditions in Zhengzhou’s periphery degraded over the past two decades, the inner city showed improvement in urban heat island and carbon sequestration. Trade-off efficiency exhibited an overall upward trend during 2000–2020, despite initial declines in some inner city areas. Interaction detection demonstrates significant synergistic effects between pairs of drivers, such as the Normalized Difference Vegetation Index and building height, and the number of patches of green spaces and the patch cohesion index of built-up land, with q-values of 0.298 and 0.137, respectively. In light of the spatiotemporal trend of trade-off efficiency and its drivers, we propose adaptive management strategies. The framework could serve as guidance to assist decision-makers and urban planners in monitoring urban–ecological conditions in the context of urban expansion. Full article

Tunneling in loose soil and urban areas presents numerous challenges. One effective solution is the use of Earth Pressure Balance Shields (EPBSs). Maintaining the correct balance of pressure at the tunnel face is critical, as applying too little pressure can cause a collapse, while excessive pressure may result in a blow-out. Therefore, a key aspect of using EPBSs in urban environments is determining the optimal pressure required to stabilize the tunnel face, taking into account the existing soil in the excavation chamber and controlling the screw conveyor’s rotation rate. This study focuses on a section of the second line of the Tabriz subway to evaluate the minimum pressure needed for tunnel face stability using empirical, analytical, and numerical approaches. The analytical methods involve evaluating the limit equilibrium of forces and considering soil buckling due to overburden, while the numerical methods employ 3D finite element analysis. Additionally, a sensitivity analysis of the parameters affecting the required pressure was conducted and compared across the three approaches. The results revealed that the formation of a pressure arch mitigates the full impact of overburden pressure on the tunnel face. For soil cohesion values below 20 kPa, the numerical results aligned well with the empirical and analytical findings. For a tunnel depth of 22.5 m and a water table 2 m below the surface, the estimated minimum pressure ranged from 150 to 180 kPa. Moreover, the analytical methods were deemed more suitable for determining the required support pressure at the tunnel face. These methods considered wedge and semi-circular mechanisms as the most probable failure modes. Also, for cohesive ground, the pressure from the finite element analysis was found to be almost always equal to or greater than the values obtained with the analytical solutions. Full article

Composite materials play a crucial role in various industries, including aerospace, automotive, and shipbuilding. These materials differ from traditional metals due to their high specific strength and low weight, which reduce energy consumption in these industries. The damage behavior of such materials, especially when subjected to stress discontinuities such as central holes, differs significantly from materials without holes. This study examines this difference and predicts the damage behavior of carbon fiber composites with multiple holes using a progressive damage model through finite element analysis (FEM). Two holes were positioned along the central axis of symmetry in the longitudinal and transverse directions relative to the load. The presence of additional holes acts as a stress-relief factor, reducing stress by up to 17% when the holes are arranged in the longitudinal direction. A cohesive zone model with two parameters, including constant and linear shapes, was applied to develop a simple analytical model for calculating the nominal strength of multi-hole composite laminates, based on the unnotched plate properties of the material. The results closely match experimental findings. The data also provide design tables that can assist with material selection. Full article

Molybdenum disulfide is a 2D material with excellent lubricant properties, resulting from weak van der Waals forces between lattice layers and shear-induced crystal orientation. The low forces needed to shear the MoS₂ crystal layers grant the tribological system low coefficients of friction (COF). However, film oxidation harms its efficacy in humid atmospheres, leading to an increased COF and poor surface adhesion, making its use preferable in dry or vacuum conditions. To overcome these challenges, doping MoS₂ with elements such as Nb, Ti, C, and N emerges as a promising solution. Nevertheless, the adhesion of these coatings to a steel substrate presents challenges and strategies involving the reduction in residual stresses and increased chemical affinity to the substrate by using niobium-based materials as interlayers. In this study, Nb-doped MoS₂ films were deposited on H13 steel and silicon wafers using the pulsed direct current balanced magnetron sputtering technique. Different niobium-based interlayers (pure Nb and NbN) were deposited to evaluate the adhesion properties of Nb-doped MoS₂ coatings. Unlubricated scratch tests, conducted at room temperature and relative humidity under a progressive load, were performed to analyze the COF and adhesion of the coating. Instrumented indentation tests were conducted to assess the hardness and elastic modulus of the coatings. The microstructure of the coatings was obtained by Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), and Transmission Electron Microscopy (TEM), with Energy-Dispersive X-Ray Spectroscopy (EDS). Results indicated that niobium doping on MoS₂ coatings changes the structure from crystalline to amorphous. Additionally, the Nb concentration of the Nb:MoS₂ coating changed the mechanical properties, leading to different cohesive failures by different loads during the scratch tests. Results have also indicated that an NbN interlayer optimally promoted the adhesion of the film. This result is justified by the increase in hardness led by higher Nb concentrations, enhancing the load-bearing capacity of the coating. It is concluded that niobium-based materials can be used to enhance the adhesion properties of Nb-doped MoS₂ films and improve their tribological performance. Full article

The concept of rocking foundations has been successfully tested and promoted for building and bridge foundations. In this paper, the applicability of rocking foundations to wind turbines is investigated, specifically for wind turbines constructed on undrained clay. An efficient form of von Mises constitutive model with non-linear kinematic hardening is integrated with the ABAQUS finite element software by a computer code and validated against experimental data. A cohesive contact of foundation–soil with limited tension is applied to simulate suction stresses at the foundation bottom–soil interface, which better represented the rocking foundation behavior. The obtained finite element results demonstrate that by allowing minimal foundation uplift under operational loads, an existing foundation can be used to support loads from a larger wind turbine than it is designed for. Allowing such uplifts corresponds to a rocking foundation design that is demonstrated in this paper to be safe and functional for a wind turbine under both operational and extreme conditions. Full article

Context: The systematic evaluation of a practitioner’s adherence to and competence in delivering psychotherapeutic interventions can be complex. This study describes the development of a fidelity assessment tool for the Reitman Centre CARERS Program (RCCP), a carer group-psychotherapy intervention with multiple didactic and clinical components. The tool’s value in informing psychotherapy training and best practices for practitioners from diverse professional settings is examined. Methods: The RCCP Fidelity Assessment Tool (RCCP-FAT) was developed following an iterative process of item writing and checking. Seven components of the RCCP—Group Structure, Dementia Education, Problem-Solving Techniques, Therapeutic Simulation, Vertical Cohesion, Horizontal Cohesion, and Overall Global Rating—were assessed, with three to eight items, and a “global score” assigned to each. Fifteen trained raters were paired up to rate 36 RCCP sessions using the RCCP-FAT. Rater agreement, correlation between itemized and global scores, and correlation between global ratings and RCCP participants’ satisfaction were calculated. Results: A total of 1188 RCCP-FAT items were rated by each of the two rater groups. Rater agreement was calculated to be 54.3% (κ = 0.32; 95% CI, 0.02681–0.3729). A positive correlation was found between the itemized and global scoring for four RCCP components evaluated (R = 0.833 to 0.929; p < 0.01). The global score and the participants’ satisfaction with “Simulation” was also positively correlated (R = 0.626, p < 0.01). Conclusions: The study provided evidence for fair rater agreement for all RCCP-FAT assessment items. More importantly, the process of developing the tool systematically crystallized the clinical elements of the RCCP and helped to standardize the training methods by creating a framework for providing feedback to learners that matches the items on the RCCP-FAT. The use of the RCCP-FAT to guide the training and mentoring of incoming group leaders is essential in the scaling and dissemination of a complex training method like the RCCP to ensure fidelity to the original evidence-based intervention. Full article

This study evaluates four widely used fracture simulation methods, comparing their computational expenses and implementation complexities within the finite element (FE) framework when employed on heterogeneous solids. Fracture methods considered encompass the intrinsic cohesive zone model (CZM) using zero-thickness cohesive interface elements (CIEs), the standard phase-field fracture (SPFM) approach, the cohesive phase-field fracture (CPFM) approach, and an innovative hybrid model. The hybrid approach combines the CPFM fracture method with the CZM, specifically applying the CZM within the interface zone. The finite element model studied is characterized by three specific phases: inclusions, matrix, and the interface zone. This case study serves as a potential template for meso- or micro-level simulations involving a variety of composite materials. The thorough assessment of these modeling techniques indicates that the CPFM approach stands out as the most effective computational model, provided that the thickness of the interface zone is not significantly smaller than that of the other phases. In materials like concrete, which contain interfaces within their microstructure, the interface thickness is notably small when compared to other phases. This leads to the hybrid model standing as the most authentic finite element model, utilizing CIEs within the interface to simulate interface debonding. A significant finding from this investigation is that within the CPFM method, for a specific interface thickness, convergence with the hybrid model can be observed. This suggests that the CPFM fracture method could serve as a unified fracture approach for multiphase materials when a specific interfacial thickness is used. In addition, this research provides valuable insights that can advance efforts to fine-tune material microstructures. An investigation of the influence of interfacial material properties, voids, and the spatial arrangement of inclusions shows a pronounced effect of these parameters on the fracture toughness of the material. Full article

The aging of the population is a key challenge for society today, with important implications for psychological and social sustainability. The persistence of negative attitudes toward older people leads to ageism, a form of discrimination that hinders an inclusive and equitable society. This study aims to develop a scale to assess attitudes toward old age and to analyze its psychometric properties in university students. The sample consisted of 185 university students aged between 19 and 44 years. A 35-item questionnaire was used, divided into two scales measuring positive and negative attitudes toward old age, each with three factors. The results indicate that the Attitudes toward Aging Scale (AAS) is suitable for measuring both attitudes and is a valid and reliable tool for diagnosing both negative and positive attitudes, as well as facilitating prevention and intervention strategies against ageism. From a sustainability psychology perspective, the use of the AAS contributes to a more equitable and sustainable society by promoting inclusive attitudes toward aging. This approach allows population aging to be seen not only as a demographic challenge, but also as an opportunity to promote intergenerational well-being and social cohesion, key elements for long-term sustainability. The limitations of this study include the small sample size, which could affect the generalizability of the results, but are justified by the contextual relevance of the sample, focusing on a key university group for the formation of future social and educational attitudes. Full article

Moving on in my recovery (MOIMR) is a new, acceptance and commitment therapy (ACT) based group intervention to support recovery from substance use disorder. It was co-developed by, and is co-facilitated with, people in recovery. This study used a grounded theory model to understand the process of change experienced by individuals who completed the group programme. Ten individuals who were abstinent from substances following their participation in MOIMR were interviewed. The model that emerged depicted a chronological series of processes that centred around a core category of gains derived from approaching their emotional vulnerability by leaning in to discomfort (e.g., difficult internal experiences like thoughts, emotions, and physical sensations) whilst pursuing activities that aligned to what mattered to them. Initial key processes indicated that participants experienced a degree of suffering from substance use prior to engagement. Group safety was a key element in fostering connection, normalisation, and cohesion, combined with psychological understanding being significantly derived from those with a lived experience of substance misuse and addiction. Later processes reflecting core ACT mechanisms such as letting go, value-guided action, and acceptance of difficult internal experiences took time to develop; many participants reported completing MOIMR more than once as a means of understanding these components. Limitations, along with implications for clinical practice and future research are discussed. Full article

There are significant lithological and stress differences between continental shale layers, posing challenges for hydraulic fractures (HFs) to propagate through the formations, leading to weak fracture effects. To address this, this article adopts the finite element and cohesive force element methods to formulate a three-dimensional numerical model for hydraulic fracture (HF) propagation through layers, considering interlayer lithology and stress variations. The accuracy of the model was verified by physical experiments, and the one-factor analysis method was used to creatively reveal the complex mechanism of the effect of geological and engineering variables on the diffusion of HFs in continental shale reservoirs. The results show that high interlayer stress difference, high interlayer tensile strength difference, low interlayer Young’s modulus difference and large interlayer thickness are not conducive to the penetration of HFs, but increasing the injection rate and the viscosity of fracturing fluid can effectively improve the penetration of HFs. The influence ranking of each factor was determined using the grey relational degree analysis method: interlayer stress difference > interlayer Young’s modulus difference > interlayer tensile strength difference > interlayer thickness > injection rate > fracturing fluid viscosity. Full article

Optimizing the cost function in predictive control of multi-phase drives is computationally intensive. This poses a challenge since the required sampling period for drives falls within the microsecond range. Numerous methods have been proposed in the literature to address this computational demand. This paper reviews recent proposals for multi-phase drives of various kinds. A structured classification of the proposals is provided. Furthermore, an integrated framework is employed to cohesively present and connect previously unrelated methods. Key elements such as Allowed Control Set, inter-sample modulation, and weighting factor use are identified. New developments in multi-vector and single-vector approaches are discussed. Practical limitations for each approach are also considered. Full article

This paper introduces an alternative method for determining the shear strength parameters of concrete materials, specifically the rectangular section splitting method, to ascertain the shear strength parameters of concrete materials. Based on the Mohr–Coulomb failure criterion, formulas for calculating the cohesion (c) and the angle of internal friction (φ) of concrete materials are derived. Numerical simulation is employed to fit and solve for the coefficients involved in the formulas. Subsequently, the concrete rectangular section splitting method and direct shear tests are utilized to verify the derived formulas. The results indicate that there is a certain feasibility to the shear strength parameters obtained for concrete materials through the rectangular section splitting method. The cohesion (c) differs by approximately 3.65%, and the angle of internal friction (φ) differs by about 6.94% when compared to the shear strength parameters obtained through direct shear tests. This suggests that the rectangular section splitting method provides a viable approach for determining the shear strength parameters of concrete materials. Full article

The deprivation of historical and cultural testimony has a direct impact on a territory and its local communities, leading to the loss of social cohesiveness, identity values, and resources that come from sustainable tourism. Even though international action frameworks (Hyogo Framework for Action, Sendai Framework for Action, and 2030 Sustainable Development Goals) emphasise how important it is to recognise the relationship between heritage, society, and territory, a strategic and sustainable vision of participatory conservation and safeguarding is still required on a local level. Through the activities implemented within the SIRIUS and RESTART projects, led by the Department of Cultural Heritage, University of Bologna, this paper aims to stimulate a reflection on how the cultural heritage of a place might constitute an effective resilience tool for the impacted populations, with a focus on young citizens. As a transversal element in achieving the 17 Sustainable Development Goals, cultural heritage can play a significant role in the establishment of a “risk culture” among residents and visitors, promoting the adoption of responsible behaviours for one’s own safety in an emergency and for the better preservation of cultural assets. In a broader perspective, this strategy will support “climate-sensitive” tourism and citizenship, which can facilitate adaptation to local climate change impacts. Full article