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The purpose of this paper is to discriminate fake interference caused by polygonal approximation so as to achieve accurate assembly sequence planning and assembly simulation.

An approximation zone model is proposed to formulate polygonal approximation. Fake interference is discriminated from hard interference by evaluating if polygonal models intersect within corresponding approximation zones. To reduce the computation, the surface-surface, surface-end face and end face-end face intersection test methods have been developed to evaluate the intersection and obtain collision data. An updated collision detection algorithm with this method is presented, which is implemented by a system named AutoAssem.

This method has been applied to a set of products such as a valve for assembly interference matrix generation, static and dynamic collision detection. The results show that it ensures the accuracy of assembly sequence planning and assembly simulation for polygonal models.

This method facilitates assembly design in the virtual environment with polygonal models. It can also be applied to computer aided design systems to achieve quick and accurate collision detection.

Fake interference between polygonal models may result in serious errors in assembly sequence planning and assembly simulation. Assembly zone model and novel polygon intersection verification methods have been proposed to effectively tackle this problem. Compared to current methods, this method considers valid penetration direction and approximation difference, does not need to process complicated auxiliary data and can be easily integrated with current collision detection methods.

The purpose of this paper is to separate and purify flavonoids existing in the leaves of Sophora japonica by a novel method, macroporous adsorption resin (MAR) mixed-bed technology, and the optimal MAR mixed bed was screened based on the adsorption experimental result with the order of single, two, three and four MAR mixed bed separately.

The adsorption performance of MAR and MAR mixed bed for flavonoids was studied using ultraviolet – visible (UV-VIS) spectrophotometry.

This research showed that the MAR mixed bed of LZ-54 + LZ-67 with a mass ratio of mLZ-54:mLZ-67 = 1:1 was the optimized combination with the optimal conditions of adsorption (volume V = 140 mL, pH = 5, T = 35°C) and desorption (liquid ratio R = 50 per cent, T = 30°C, pH = 6) obtained, relatively.

This study aims to find an efficient way of separating flavonoids and other components that are useful for human health from Sophora japonica, which is complying with the policy of sustainable development.

This contribution provided a novel way to separate flavonoids from Sophora japonica. Under the optimal conditions, the adsorption rate (F) of MAR mixed bed LZ-54 + LZ-67 to the flavonoids was 63.65 per cent, the desorption rate (D) was 87.31 per cent and the purity was dramatically achieved at 58.17 per cent from 17.67 per cent after a round of adsorption/desorption operation.

To investigate the influence of vehicle operation speed, curve geometry parameters and rail profile parameters on wheel–rail creepage in high-speed railway curves and propose a multi-parameter coordinated optimization strategy to reduce wheel–rail contact fatigue damage.

Taking a small-radius curve of a high-speed railway as the research object, field measurements were conducted to obtain track parameters and wheel–rail profiles. A coupled vehicle-track dynamics model was established. Multiple numerical experiments were designed using the Latin Hypercube Sampling method to extract wheel-rail creepage indicators and construct a parameter-creepage response surface model.

Key service parameters affecting wheel–rail creepage were identified, including the matching relationship between curve geometry and vehicle speed and rail profile parameters. The influence patterns of various parameters on wheel–rail creepage were revealed through response surface analysis, leading to the establishment of parameter optimization criteria.

This study presents the systematic investigation of wheel–rail creepage characteristics under multi-parameter coupling in high-speed railway curves. A response surface-based parameter-creepage relationship model was established, and a multi-parameter coordinated optimization strategy was proposed. The research findings provide theoretical guidance for controlling wheel–rail contact fatigue damage and optimizing wheel–rail profiles in high-speed railway curves.

The purpose of this paper is to separate and purify flavonoids from glycyrrhiza by macroporous adsorption resin (MAR) mixed-bed technology.

The adsorption performance of MAR and MAR mixed bed for flavonoids was studied using ultraviolet-visible spectrophotometry.

The research shows that the MAR mixed bed of LZ-50+LZ-59 with a mass ratio of LZ-50:LZ-59(m:m) = 1:1 was the optimized combination with the optimal conditions of adsorption (pH = 6, T = 45°C) and desorption (liquid ratio R = 70%, T = 50°C, pH = 8) obtained, relatively.

This paper provides a novel way to separate flavonoids from glycyrrhiza. Under the optimal conditions, the adsorption rate (F) of MAR mixed-bed LZ-50+LZ-59 to the flavonoids was 62.5 per cent/g, the desorption rate (D) was 89.23 per cent and the purity was achieved at 80 per cent.

This paper aims to study a new halogen-free fame-retardant curing agent 1-aminoethylidenediphosphonate (AAEDP).

The AAEDP was synthesized by phosphoric acid, acetonitrile and ammonia. The chemical structures of AAEDP were characterized by proton nuclear magnetic resonance, mass spectrometry and Fourier transform infrared spectrometer. Thermal gravimetric analysis (TGA) and scanning electron microscope (SEM) would study the thermal properties and the char residues of AAEDP/EP. The thermal stability, mechanical and flame properties and morphology for the char layer of composite materials were separately investigated using TGA, tensile and charpy impact tests, limiting oxygen index (LOI), UL-94 HB flammability standard (UL-94) and SEM.

The results showed that the AAEDP had been prepared successfully. When the intumescent flame retardant was added into the EP, the LOI of composite material was improved.

The AAEDP can be prepared successfully and can improve the flame resistance of composite material.

The AAEDP has excellent flame-retardant properties and produce no toxic fumes when burnt in case of fire.

The results showed that the phosphorus content of AAEDP was 2.958 Wt.%; the impact and tensile strength of the composite material were 6.417 kJ m⁻² and 38.0 MPa, respectively; and the LOI and UL-94 were 29.7% and V-0 ranking, respectively. The TGA results indicated that the carbon residue ratio can be increased by 1000°C in air. The denser and more uniform structure of residual carbon prevents heat transfer and diffusion, restricts the production of combustible gas and reduces the rate of heat release.

This work focused on the sulphonation modification research of highly crosslinking non-polarity macroporous adsorption resin (MAR) LX1180; the adsorption behaviour of LX1180 and its chloromethylation- and sulphonation-modified products (LX1180-Cl and LX1180-SO₃₋); and the influence of the structure parameters matching degree of MAR and flavonoids on the adsorption feature and adsorption kinetics.

LX1180-SO₃₋ was obtained by the processes of chloromethylation first and then sulphonation. LX1180-Cl and LX1180-SO₃₋ were prepared through the principle of substitution reaction from LX1180 and LX1180-Cl, respectively. First, Monochloromethyl ether (ME), pre-treated ZnCl₂, NaCl and iron powder were added into the swollen LX1180 to obtain the chloromethylated LX1180. Thereafter, NaCl, NaOH and SAA were added into the swollen LX1180-Cl to obtain the sulphonation modification LX1180. The conditions were investigated and optimised; the structures of LX1180-Cl and LX1180-SO₃₋ were characterised by Fourier transform infrared chromatography (FTIR) and a specific surface area instrument. Finally, the adsorption kinetics and adsorption isotherm were used to evaluate the adsorption capacity of LX1180-Cl and LX1180-SO₃₋ for flavonoids, and the adsorptions and desorptions of LX1180-SO₃₋ with different sulphonation degree on different flavonoids were investigated systemically.

Results showed that LX1180-Cl and LX1180-SO₃₋ had been prepared successfully, and that after the sulphonation, the adsorption capacity tended to increase with the increase of adsorption time, and the equilibrium adsorption capacity of LX1180-SO₃₋ was also higher than that of LX1180.

The research only investigated the adsorption and desorption properties for only one kind of functional group, and other functional groups should also be studied in future work.

This contribution can provide a further base for the research of separation and purification of natural products with the aim to improve food additive removal or isolation and purification of flavonoids used for healthcare applications.

The adsorptions and desorptions of LX1180-SO₃₋ with different sulphonation degree on different flavonoids were investigated. The relationship between sulphonation degree and the adsorption and desorption capacities of flavonoids were also explored, and the results showed that with the increase of sulphonation degree, the adsorption of LX1180-SO₃₋ to rutin and cyanidin was maximum, while the desorption ratio was minimum at the same sulphonation degree; this phenomenon could be ascribed to the variation in the polarity matching degree.

During the design of a new product, the generation of assembly sequences plans (ASPs) has become one of the most important problems taken into account by researchers. In fact, a good mounting order allows the time decrease of the assembly process which leads to the reduction of production costs. In this context, researchers developed several methods to generate and optimize ASP based on various criteria. Although this paper aims to improve the quality of ASP it is necessary to increase the number of criteria which must be taken into account when generating ASPs.

In this paper, an ASP generation approach, which is based on three main algorithms, is proposed. The first one generates a set of assembly sequences based on stability criteria. The obtained results are treated by the second algorithm which is based on assembly tools (ATs) workspace criterion. An illustrative example is used to explain the different steps of this proposed approach. Moreover, a comparative study is done to highlight its advantages.

The proposed algorithm verifies, for each assembly sequence, the minimal required workspace of used AT and eliminates the ASPs non-respecting this criterion. Finally, the remaining assembly sequences are treated by the third algorithm to reduce the AT change during the mounting operation.

The proposed approach introduces the concept of AT workspace to simulate and select ASPs that respect this criterion. The dynamic interference process allows the eventual collision detection between tool and component and avoids it. The proposed approach reduces the AT change during the mounting operations.

The contribution of the public–private partnership (PPP) model towards the achievement of the United Nation (UN)'s Sustainable Development Goals (SDGs) has been widely acknowledged. However, limited studies have shed light on the connection between PPPs and the achievement of these coveted goals in Ghana. In this study, the authors aimed at analysing and synthesising the existing literature on the use of PPP to achieve sustainability in infrastructure projects in the country.

A three-step approach was used to retrieve and review 60 selected articles aided by content analysis.

The analysis showed that all existing relevant publications on the application of the PPP model to attain UN’s SDGs in the country are organised around dominant themes, such as poverty alleviation, urban development, waste management and risk management. However, the review revealed little studies exist on pertinent issues relating to PPPs and sustainable development goals, such as climate action, critical resilience, sustainable finance and clean energy.

Although the study is limited to 60 articles in Ghana, the results reveal pertinent gaps for further research studies to achieve sustainable infrastructural development in Ghana and other countries.

Holistically, the outcome of this study will serve as a guide to project managers to understand essential issues on attaining sustainability on public projects.

This article contributes to the literature and practice on the significance of PPP in mainstreaming UN's SDGs in public infrastructure projects.