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To date, incineration is the main method of municipal solid waste (MSW) disposal. Fly ash and bottom ash (BA) are generated in large amounts from municipal solid waste incineration (MSWI), but the disposal of incineration residues poses a significant challenge to large cities with limited landfill space. The feasibility of using MSWI-BA to replace natural sand in the preparation of self-compacting mortar (SCM) was investigated to realize the resource utilization of MSWI-BA. The changes in SCM regarding durability, mechanical properties and workability when MSWI-BA was added at varying ratios were explored in this study. In addition, the changes in SCM microstructure, dynamic modulus of elasticity (DME) and ultrasonic pulse velocity (UPV) under the impacts of MSWI-BA were investigated. Eventually, the environmental and economic effects of SCM were weighed via the material sustainability index. It was found that (1) there was a drop of 23.79–44.69% in the compressive strength of SCM and a drop of 12.22–30.99% in the flexural strength, due to the incorporation of MSWI-BA; (2) the drying shrinkage of SCM increased from 2.9 to 11.76%, and the chloride migration coefficient increased from 4.66 to 46.06%, due to the incorporation of MSWI-BA; (3) the production costs, carbon footprint and energy consumption of SCM could be reduced, due to the addition of MSWI-BA; and (4) SCM could satisfy the engineering requirements of durability, mechanical properties and workability. Therefore, MSWI-BA was found to be a feasible method for the production of SCM. [ABSTRACT FROM AUTHOR]

Machining time and energy consumption are common process planning evaluation metrics. However, it is difficult to obtain accurate machining time and energy consumption values in the process planning stage, which may result in non-optimal obtaining process routes. To solve these problems, this paper proposes a flexible process planning method based on processing time and energy consumption prediction models. The historical processing data is analyzed, and a prediction model of machining time and energy consumption based on a radial basis function neural network is proposed. Considering the flexibility of multiple processes, a mathematical model of the flexible process planning problem based on the machining time and energy consumption prediction model is established. A multi-objective algorithm using a multidimensional real number coding method is proposed for problem-solving with the completion time and energy consumption minimization as the optimization objective. Two algorithms with better multi-objective optimization performance, the strength Pareto evolution algorithm 2, and the dominance ranking genetic algorithm II are selected for comparative analysis to obtain a better effect of optimization. The better algorithm is selected with the best parameters. Finally, case studies are conducted to verify the validity of the prediction model and the flexible process planning model. [ABSTRACT FROM AUTHOR]

Ultra-high-performance concrete (UHPC) has attracted wide interests in civil engineering but it has large deadweight, which limits its application in lightweight structures and rehabilitation. Compromising the merits of UHPC and lightweight concrete, ultra-high-performance lightweight concrete (UHPLC) is a potential solution to solve the drawback of high self-weight. Based on particle densely packing theory, this study proposed a UHPLC manufacturing approach using shale ceramic sand and air-entraining agent (AEA). An experimental study was conducted to systematically examine the effects of the types and contents of AEA on various performances of UHPLC, including its workability, mechanical properties, durability and microstructure. The results show the following: (1) The addition of AEA resulted in the decrease of UHPLC in elastic modulus, compressive strength and flexural strength but bring UHPLC higher specific strength; (2) A void system that is featured with homogeneous distribution of pores and an appropriate size and could be formed by adding a suitable amount of AEA; (3) The optimum proportion of AEA in UHPLC was 0.01% in consideration of its influence on UHPLC from the perspectives of microstructure, durability and mechanical properties. [ABSTRACT FROM AUTHOR]

Ink transfer is achieved by the squeezing and rotation of two rollers, one of which is a roller coated with a viscoelastic rubber layer. In this study, the force caused by ink hydrodynamic pressure on the rubber roller during the rotation is considered, the viscoelasticity of ink and rubber is equivalently substituted by spring-damping unit, and a rolling squeezing theoretical model of two rollers is established to study the node deformation of the rubber roller. The validity of the theoretical model is verified by experiments. Results show that the deformation of the rubber roller is greatly affected by the roller rotational speed, rubber layer thickness, and nip width. The rotational speed and nip width have a significant influence on the stiffness-damping of the ink layer and the ink force, and the rubber layer thickness has a remarkable effect on the squeezing deformation between the rollers. [ABSTRACT FROM AUTHOR]

For the flat plastic parts with the size range of 200 to 1300 mm, the structural parameters decision model of injection mold gating system is established in this paper. Firstly, the relationship between the warpage and the structural parameters of gating system is fitted by Kriging model, and the minimum warpage is optimized by genetic algorithm (GA) to obtain the best structural parameters. Secondly, the best structural parameters of gating system corresponding to 16 groups of plastic parts are taken as samples, and the relationship between the structural parameters of gating system and the size parameters of plastic parts is established by Kriging model. In addition, K-means is used to reduce the number of the structural parameters of gating system from 5 to 2, in order to improve the accuracy of decision model. Finally, the size parameters of plastic parts are input to the decision model to obtain the structural parameters of gating system. Through the verification of mold flow analysis experiment, the structural parameters of gating system obtained by this method meet the design requirements and can effectively shorten the structural design cycle of injection mold. [ABSTRACT FROM AUTHOR]

In order to improve the printing quality, this study focused on the thermo-fluid-solid coupling process of ink roller-ink. One of the highlights of this study is to consider the influence of temperature on the rubber hyperelastic parameters, viscoelastic parameters, and ink viscosity. The other highlight is to improve the elastohydrodynamic lubrication theory and Hertz contact theory through the rubber elastic modulus, which is determined by the relaxation curve considering the temperature and working conditions. Furthermore, based on the improved theory, the thermo-fluid-solid coupling model of ink roller-ink was established. Finally, the effect of temperature on the coupling process was analyzed. The results show that under the working conditions, with increasing temperature from 20 °C to 40 °C, the contact half-width increases from 4.2335 mm to 4.4701 mm, and the minimum ink film thickness decreases from 0.5097 mm to 0.1410 mm, and the maximum ink pressure decreases from 0.6802 MPa to 0.6618 MPa. [ABSTRACT FROM AUTHOR]

The reliability allocation of machine tools which is a multi-attribute decision-making problem has great significance in designment of machine tools. This paper integrates the intuitionistic trapezoidal fuzzy numbers and performance sorting technique based on similar ideal solutions to achieve the flexible allocation of machine tools reliability. Firstly, intuitionistic trapezoidal fuzzy numbers are employed to integrate decisions made by multiple decision-makers and fuzzy information of their preferences. Then, intuitionistic trapezoid fuzzy numbers' expectations are treated as the weights of criteria. Finally, performance sorting technique based on similar ideal solutions is used to obtain the reliability allocation weight of every subsystem. To investigate the efficacy and simplicity of the provided approach, reliability distribution in a CNC machine tool is introduced as an example to explain its specific contents. It can be concluded that the provided method is more precise and convenient by comparing the results of this approach with those obtained by analytic hierarchy process method. [ABSTRACT FROM AUTHOR]

In the actual production, it is expected to find several sensitivity geometric errors which have great influence on machining accuracy, so as to provide references for the manufacturing, assembly, and other links of the machine tool, and fundamentally improve the working performance. To study this problem, a novel global sensitivity analysis (GSA) method is proposed. Based on the MBS theory, the spatial error model is established to analyze the local influence of geometric error on machining accuracy. An improved second-order partial correlation coefficient based on the Pearson product moment is proposed to analyze the correlation between geometric errors. In addition, the error parameters will change greatly in the stroke of the moving parts. However, the rapid fluctuation of geometric error value will have a dynamic impact on the machining accuracy of machine tools, which is rarely noticed in the previous sensitivity analysis. This change is defined as the fluctuation of error. The high fitting degree function of error-displacement is obtained by using the high order Fourier series and sine series. Then, the fluctuation of the error in the machining stroke is analyzed by using the derivative of the function to the displacement. Through geometric error characteristics (including the local influence, correlation, and fluctuation) are studied comprehensively, the GSA of error is carried out. Finally, taking a machining center as an example and combining the sensitivity analysis results, the improvement measures are proposed to verify the correctness of the method. [ABSTRACT FROM AUTHOR]

Background: Genetic variants in the excision repair cross-complimentary group 2 (ERCC2) gene may affect individual susceptibility to cancer by modulating the capability of DNA damage repair. However, the current studies concerning the association of ERCC2 rs13181 polymorphism with ovarian cancer risk provided inconsistent evidence.Methods: This study was to quantitatively summarize the evidence from the individual studies electronically retrieved by a meta-analysis.Results: Totally, nine eligible case-control studies with 1333 cases and 2691 controls were included for the concerned association. Overall, a significant association between ERCC2 gene rs13181 polymorphism and increased risk of ovarian cancer was revealed (CC+AC vs. AA: OR 1.44, 95% CI 1.11-1.86; CC vs. AA: OR 2.12, 95% CI 1.14-3.97). Similarly, in the subgroup analyses, such association was also evident in non-Caucasian population and hospital-based studies. Noteworthily, the recombined analysis with a significant decrease in between-heterogeneity represented a significant association of the variant with increased risk of ovarian cancer after excluding the individual study not in agreement with HWE.Conclusion: The present study suggests that the ERCC2 gene rs13181 polymorphism might be associated with increased risk of ovarian cancer. [ABSTRACT FROM AUTHOR]