In today’s competitive global business environment, platform strategy presents an opportunity for manufacturing companies to juggle increased customer demand for customized products and the inherited complexity and increased development cost that comes with it. The goal of this paper is to support module identification as an essential part of a module-based platform strategy approach. Based on various existing methods, this paper abstracted three principles, which include an internal clustering principle, an external independence principle, and an overall stability principle. The three principles should be holistically considered, and be simultaneously satisfied during the module identification. Both conceptual and mathematical modeling of the proposed multi-principle module identification method are elaborated. Then an improved strength Pareto evolutionary algorithm (ISPEA2) is used to address the multi-principle module identification problem and find the Pareto-optimal set. A fuzzy compromise selection method base on fuzzy set theory is also used to select the best compromise Pareto solution. An industrial case study in a turbo expander manufacturing company is provided to illustrate practical applications of the research. Finally, the result obtained by the proposed approach is compared with other established optimization approaches.

Diesel sprays are important to engine combustion and emission formation processes, however, their behaviors are difficult to predict as they are very sensitive to the internal geometries of the nozzle. Based on synchrotron radiation X-ray tomography, a novel method is presented for measuring automatically the orifice diameter and length of fuel nozzles. According to this method, a clear definition of orifice inlet and outlet is given, and the diameters along the orifice from inlet to outlet as well as the orifice length can be measured. Measurements of a single-hole nozzle and an eight-hole nozzle have been performed accordingly. The results show that this method can automatically measure the orifice diameters from outlet to inlet along the whole orifice axis with relatively high precision, regardless of whether it is a single-hole or a multi-hole nozzle. The profile of the diameters obtained shows the differences between the nominal dimensions and the actual ones, which gives a more precise feedback for nozzle manufacture, and provides a new basis for precisely studying the impacts of internal geometries on spray behavior.

The forecasting capability of the weather research and forecasting (WRF) model for heavy precipitation in the downstream area of the Yalong River Basin in Southwest China was evaluated for the first time through the simulation of three heavy precipitation events with seven commonly used microphysics parameterization schemes (MPS) (Kessler, Lin et al. (Lin), Single-Moment 3-class (WSM3), Single-Moment 5-class (WSM5), Ferrier, Single-Moment 6-class (WSM6), and New Thompson et al. (NTH)) and three cumulus parameterization schemes (CPS) (Kain-Fritsch (KF), Betts-Miller-Janjic (BMJ), and Grell-Devenyi (GD)). Of the three rainfall events, the first two are typical large-area heavy precipitation events in the Yalong River Basin and consist of several continuous storms. The third one is a heavy precipitation event with only one storm. In this study, a triple nested domain with a 3-km grid resolution inner-most domain over the study area was configured for the WRF model. We employed the probability of detection (POD), false alarm ratio (FAR), BIAS, and equitable threat (ET) scores to compare the spatial distribution of heavy rainfall created by the WRF model with the observations from the gauges in the downstream area of the river basin. The root mean squared errors (RMSEs) at each sub river basin and the whole downstream of Yalong River Basin were also calculated for the evaluation. In addition, it is important to include the computation efficiency when choosing a scheme combination. We recorded the time consumption for each model simulation and made comparisons for selecting the optimum scheme with less time consumption and acceptable prediction accuracy. Through comprehensive comparison, the scheme combination of WSM3 and GD holds a stable performance in leveraging the prediction accuracy and computation efficiency for the heavy precipitation events.

Investigation on the mechanical properties of cement-based materials at micron and sub-micron scales is important for understanding its overall performance. Recent progress in experimental nanomechanics opens new access to nano-engineering of cement-based composites. In this study, nanoindentation and viscoelastic modulus mapping were employed to study the interfacial properties. The interface width measured by modulus mapping was around 250 nm as compared to a rough estimation of less than 5 μm by nanoindentation, due to the fact that 2 orders of magnitude increase in spatial resolution could be achieved by modulus mapping. Both the nanoindetation and modulus mapping results indicated that the modulus of the interface falls between 60–70 GPa. The packing density in the interface was non-uniform as two peaks of value were observed for the storage modulus distribution. This interface could be regarded as a dense hydration coating around cement grains, which was less permeable and hindered the further hydration of cement.

Fiber-reinforced plastic-wrapped concrete columns (FRP-C) have been extensively used in building structures and transportation infrastructures around the world during the past two decades. These members are actually subjected to a long-term sustained axial compression before they experience the designated ultimate loading. However, little attention has been given to the performance of FRP-C after sustained axial compression compared with that of its short-term instant performance. This study aims to establish a design-oriented numerical model for the long-term deformation of circular FRP-C after sustained load. A modified constitutive model of FRP-wrapped concrete is proposed for numerical analysis of FRP-C considering two dominant effects of sustained axially compressive loading. Numerical verifications against existing tests indicates that the ultimate strength will be slightly enhanced while the ultimate strain will be conspicuously reduced in most cases of normal strength FRP-C after a long-term sustained load.

This study explores the use of rice husk ash (RHA) and manufactured sand (M-sand) as replacements for cement and fine aggregate, respectively, in lightweight oil palm shell concrete (OPSC). In the first stage of this study, the effect of various cement replacement levels, with RHA (5%, 10%, 15%, and 20%) and 100% sand replacement with M-sand and quarry dust (QD), on the compressive strength of OPSC was investigated. The results showed that the highest compressive strength of OPSC of about 51.49 MPa was achieved with the use of 15% RHA and M-sand. In the second stage of the work, the variables of RHA (0 and 15%) and M-sand (0, 50%, and 100%) were used to investigate their combined effects on the mechanical properties of OPSC. It was found that the combination of 15% RHA and 100% M-sand gave the best performance of OPSC in terms of mechanical properties, such as compressive, splitting tensile, flexural strength, and Young’s modulus.

Heavy metals released from municipal solid waste incinerators have become a major environmental concern. A comprehensive knowledge of metal vapor condensation in fly ash particles during incineration is essential for alleviating heavy metal toxicity, and for optimizing incineration process parameters and flue-gas cleaning systems. In this paper, the condensation of zinc vapor during flue-gas cooling in a 200 t/d fluidized bed incinerator and a 150 t/d moving grate incinerator was characterized and comparatively studied using high resolution synchrotron X-ray absorption spectroscopy (XAS). Principal component analysis, target transformation, and linear combination fitting were employed to identify zinc species directly from size fractionated fly ash particles. The chemical reaction behaviors of different zinc species were described by thermodynamic equilibrium simulations. Consistent with previous theoretical analysis and laboratory scale tests, the condensation behavior of zinc in an industrial incineration system is mainly affected by the sulfur/chlorine ratio and the inorganic particulates. It is found that zinc chloride is the major zinc species in a moving grate incinerator but willemite dominates in the fluidized bed incinerator. The high sulfur and silica/alumina particle concentration in the fluidized bed system changes the condensation propensity of vapors of Zn compounds. Adjusting the concentrations of SO₂ in flue-gas can inhibit the formation of zinc chlorides. Silica, alumina, aluminosilicates, and calcium-based compounds are potential sorbents for transforming zinc to less harmful species. To prevent toxic zinc species contained in fine particles from escaping into the atmosphere, wet scrubbers are more suitable for cleaning flue-gases in moving grate incineration systems, while improving the efficiency of dust removal is more important for fluidized bed incineration systems.