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The purpose of this paper is to explore the possibility of an enhanced continuous liquid interface production (CLIP) with a porous track-etched membrane as the oxygen-permeable window, which is prepared by irradiating polyethylene terephthalate membranes with accelerated heavy ions.

Experimental approaches are carried out to characterize printing parameters of resins with different photo-initiator concentrations by a photo-polymerization matrix, to experimentally observe and theoretically fit the oxygen inhibition layer thickness during printing under conditions of pure oxygen and air, respectively, and to demonstrate the enhanced CLIP processes by using pure oxygen and air, respectively.

Owing to the high permeability of track-etched membrane, CLIP process is demonstrated with printing speed up to 800 mm/h in the condition of pure oxygen, which matches well with the theoretically predicted maximum printing speed at difference light expose. Making a trade-off between printing speed and surface quality, maximum printing speed of 470 mm/h is also obtained even using air. As the oxygen inhibition layer created by air is thinner than that by pure oxygen, maximum speed cannot be simply increased by intensifying the light exposure as the case with pure oxygen.

CLIP process is capable of building objects continuously instead of the traditional layer-by-layer manner, which enables tens of times improvement in printing speed. This work presents an enhanced CLIP process by first using a porous track-etched membrane to serve as the oxygen permeable window, in which a record printing speed up to 800 mm/h using pure oxygen is demonstrated. Owing to the high permeability of track-etched membrane, continuous process at a speed of 470 mm/h is also achieved even using air instead of pure oxygen, which is of significance for a compact robust high-speed 3D printer.

The purpose of this paper is to unveil the circular economy (CE) values with an ultimate goal to provide tenets in a format or structure that can potentially be used for designing a circular, closed-loop supply chain and reverse logistics.

This is desk-based research whose data were collected from relevant publication databases and other scientific resources, using a wide range of keywords and phrases associated with CE, reverse logistics, product recovery and other relevant terms. There are five main steps in the reformulation of CE principles: literature filtering, literature analysis, thematic analysis, value definition and value mapping.

In total, 15 CE values have been identified according to their fundamental concepts, behaviours, characteristics and theories. The values are grouped into principles, intrinsic attributes and enablers. These values can be embedded into the design process of product recovery management, reverse logistics and closed-loop supply chain.

The paper contributes to the redefinition, identification and implementation of the CE values, as a basis for the transformation from a traditional to a more circular supply chain. The reformulation of the CE values will potentially affect the way supply chain and logistics systems considering the imperatives of circularity may be designed in the future.

The reformulation principles, intrinsic attributes and enablers of CE in this paper is considered innovative in terms of improving a better understanding of the notion of CE and how CE can be applied in the context of modern logistics and supply chain management.

As a typical resource energy-intensive industry, the scale of construction industry has been expanding rapidly owing to the large-scale urbanization and the economic booming in China, which results in a sharp increase in the energy consumption of construction industry. However, it is infeasible to mitigate the energy consumption by reducing the production activities of construction industry. Therefore, improving the energy efficiency of construction industry is essential for energy saving. Construction industry has close relationships with other industries. The production activities have not only consumed a great deal of energy but they have also generated a massive energy consumption from other industries. Previous literature studied the efficiency of energy consumed directly by the construction industry. However, no research has been found focusing on the efficiency of energy consumed directly by the construction industry and indirectly by the related industries. The purpose of this paper is to put forward a total energy efficiency evaluation framework to measure the energy efficiency of construction industry in depth.

This paper employs the data envelopment analysis (DEA) method and the framework of embodied energy efficiency (EEE) to establish a total energy efficiency evaluation model. Next, the comprehensive analysis of direct energy efficiency (DEE) and EEE in different provinces with various levels of urbanization and various economic levels is conducted.

The results show that the embodied energy intensity and its regularities differ greatly between provinces. From the comparison of DEE and EEE, the provinces of Zhejiang and Jiangsu remain DEA-effective and Hainan is the only province in which the EEE is higher than DEE in 2002, 2007 and 2012. Besides, the DEE and EEE in the provinces with higher levels of urbanization and high economic levels are not more effective than those in the provinces with relatively lower levels of urbanization and low economic levels.

Previous literature studied the efficiency of energy consumed directly by the construction industry while ignoring the energy consumed indirectly by the related industries. Besides, no research has been found focusing on the regulation of energy efficiency in different provinces with different levels of urbanization and different economic levels. It can be concluded that the increasing levels of urbanization and higher economic levels have not brought development and benefits for improving DEE and EEE. Therefore, under the condition that the self-regulation of construction industry and market fail to facilitate the improvement of DEE and EEE in China, policymakers should develop policies and market incentive mechanism to encourage construction industry for employing new technologies to improve the energy efficiency. Since the EEE can reveal the energy efficiency in depth, the evaluation method of EEE should be paid more attention. Besides the fact that the EEE is lower than the DEE in almost all provinces, except Hainan province, the industrial structure is essential to develop the EEE. Hence, improving the energy structure, increasing the energy efficiency and developing new and renewable energy are the basic energy strategies in China.

The construction industry has always been regarded as a stressful and task-driven industry with high levels of work pressure. When the stressful situations are prolonged, job burnout becomes unavoidable for construction professionals. The purpose of the present paper is to investigate the critical predictors of burnout among civil engineers at construction sites in Turkey and identify the impact of those determined burnout predictors on various burnout dimensions.

The possible causes of burnout for civil engineers at construction sites were determined using an extensive literature review and were further studied using a questionnaire. The obtained data were analysed statistically using SPSS 22 and LISREL 8.7 software. Correlation analysis, exploratory and confirmatory analysis, and structural equation modelling were performed on this collected data, and a structural model was developed.

Three critical factors affecting burnout levels of civil engineers in construction sites were determined; among them “organisational injustice” and “competitive pricing and lack of contract management” were identified as the critical predictors of burnout in the emotional-exhaustion and cynicism dimensions. Based on these predictors, potential solutions and recommendations are proposed that are anticipated to decrease the burnout among civil engineers at construction sites.

Although there are several works of research regarding the burnout among construction professionals, there is limited research that has provided insight into the specific factors causing burnout among civil engineers. This research presents a structural model of the predictors obtained by a confirmatory factor analysis for decreasing the burnout level of civil engineers at construction sites. The current study represents the first comprehensive quantitative determination of the factors and predictors of burnout among civil engineers at construction sites in Turkey.