XuDong Wang, Zhenbin Chen, Jiapeng Long, Chenglong Duan and Xueyan Du
The purpose of this paper is to separate and purify flavonoids from glycyrrhiza by macroporous adsorption resin (MAR) mixed-bed technology.
Abstract
Purpose
The purpose of this paper is to separate and purify flavonoids from glycyrrhiza by macroporous adsorption resin (MAR) mixed-bed technology.
Design/methodology/approach
The adsorption performance of MAR and MAR mixed bed for flavonoids was studied using ultraviolet-visible spectrophotometry.
Findings
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.
Originality/value
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.
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Yingyu Zhao, Zhenbin Chen, Donglei Liu, Jiapeng Long and Duolong Di
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…
Abstract
Purpose
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.
Design/methodology/approach
The adsorption performance of MAR and MAR mixed bed for flavonoids was studied using ultraviolet – visible (UV-VIS) spectrophotometry.
Findings
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.
Practical implications
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.
Originality/value
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.
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Jiapeng Long, Sanxi Li and Bing Liang
This paper aims to study a new halogen-free flame retardant that was prepared and characterised.
Abstract
Purpose
This paper aims to study a new halogen-free flame retardant that was prepared and characterised.
Design/methodology/approach
The phenyl phosphinic arid di-4-[1-(4-pheny phodphonic acid monophenyl ester-yl)-methyl-ethyl] phenyester dimelaminium (PDEPDM) was synthesised using phenylphosphonic dichloride, melamine, bisphenol A, triethylamine and dichloromethane via solvent-based reaction, that was added into the polyethylene to test flame performance. The chemical structures of PDEPDM were characterised by 1H nuclear magnetic resonance spectroscopy, mass spectrometry and Fourier transform infrared spectrometer. The thermal stability, mechanical and flame properties, and morphology for the char layer of composite materials were separately investigated using thermogravimetric analysis, tensile and charpy impact tests, limiting oxygen index (LOI) and UL-94 HB flammability standard and scanning electron microscope.
Findings
The results showed that the PDEPDM had been prepared successfully. When the intumescent fame retardant was added into the PE, the LOI of composite material was improved.
Research limitations/implications
The PDEPDM can be prepared successfully and can improve the flame resistance of composite material.
Practical implications
The PDEPDM has excellent flame-retardant properties and produce no toxic fumes when burnt in case of fire.
Originality/value
Under the optimal conditions, when the 32 per cent (Wt.%) PDEPDM was added into the PE, the LOI was 29.8, tensile strength and impact strength were 10.06 MPa and 16.77 kJ/m2.
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Yushuang Wu, Jiapeng Long, Bing Liang and Yan Yanan
This paper aims to study a new halogen-free fame-retardant curing agent 1-aminoethylidenediphosphonate (AAEDP).
Abstract
Purpose
This paper aims to study a new halogen-free fame-retardant curing agent 1-aminoethylidenediphosphonate (AAEDP).
Design/methodology/approach
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.
Findings
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.
Research limitations/implications
The AAEDP can be prepared successfully and can improve the flame resistance of composite material.
Practical implications
The AAEDP has excellent flame-retardant properties and produce no toxic fumes when burnt in case of fire.
Originality/value
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.
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Ting Huo, Zhenbin Chen, Jiapeng Long, Lei Kang, Duolong Di and Xueyan Du
This work focused on the sulphonation modification research of highly crosslinking non-polarity macroporous adsorption resin (MAR) LX1180; the adsorption behaviour of LX1180 and…
Abstract
Purpose
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.
Design/methodology/approach
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.
Findings
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.
Research limitations/implications
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.
Practical implications
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.
Originality/value
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.
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Zhenbin Chen, Jiapeng Long, Lei Kang, Xueyan Du, Duolong Di and Jingbo Liu
The purpose of this paper is to prepare a higher chloromethylation degree (CD) modified macroporous adsorption resin (MAR, LX1180-Cl) and further study their adsorption…
Abstract
Purpose
The purpose of this paper is to prepare a higher chloromethylation degree (CD) modified macroporous adsorption resin (MAR, LX1180-Cl) and further study their adsorption performance.
Design/methodology/approach
CD and crosslinking degree were evaluated using stationary potential step and rotating-disk method, the adsorption performance of LX1180-Cl and LX1180 for flavonoids were studied using the UV-VIS spectrophotometry.
Findings
This research realized high CD (9.6 mass %) on high crosslinking MAR, LX1180. In tandem, the adsorption performance of them to flavonoids finds that the matching degree of polarity (presented with CD) and size were the critical factor to adsorption. It was also found that the reaction time had reduced to 24 h with the addition of iron particles into the zinc chloride (ZnCl2) catalyst.
Research limitations/implications
The study on reaction mechanism and the function principle of hybrid catalyst were speculated, but not the rigid experimental result.
Practical implications
This contribution can provide a rule for the separation and purification of natural products with the aim to improve food additive removal or isolation and purification of flavonoids used for healthcare applications.
Originality/value
This contribution provided a novel way to obtain high degree of CD with high crosslinking MAR, CD of commercially available MAR was improved by 2.5 times to 9.6 percent under crosslinking degree at 58.2 percent, compared with reported CD value (ca. 4.2 percent under crosslinking degree at 20.0 percent), which will be useful in the following further systematically research about the adsorption and separation selectivity of MAR. Besides, the primitive chosen principle of MAR according to the substrate was also presented. Moreover, the chloromethylation mechanism, although speculative, was briefly presented, which will stimulate the related study.
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Jiapeng Wu, Dayu Gao, Cheng Xu and Yanqi Sun
This paper aims to investigate the influence of the regional business environment on local firm innovation, considering various dimensions such as administrative, financial and…
Abstract
Purpose
This paper aims to investigate the influence of the regional business environment on local firm innovation, considering various dimensions such as administrative, financial and legal environments.
Design/methodology/approach
Multiple regression analysis is employed to analyze archival data for firms listed on Chinese stock markets.
Findings
We find that the optimizations of the administrative and financial environments positively affect firm innovation, whereas the legal environment does not exert a similar impact. Our analysis also reveals that the business environment’s optimization significantly influences innovation in firms that are small, non-state-owned and operating in high-tech industries. Furthermore, the business environment acts as a moderating variable in the relationship between firm innovation and firm value.
Research limitations/implications
This study contributes to a more comprehensive understanding of institutional-level determinants of firm innovation, highlighting the nuances of the legal environment and the importance of context-specific analysis, especially in emerging markets like China.
Practical implications
Developing countries can significantly enhance firm innovation by improving the business environment, including the optimization of administrative and financial systems, reducing transaction costs and ensuring capital supply. Tailored legal frameworks and alternative institutional strategies may also be explored.
Social implications
This study explicitly emphasizes the governmental role in promoting firm innovation, shedding light on policy formulation and strategic alignment with local administrative policies.
Originality/value
To the best of our knowledge, this paper is the first to explore the relationship between the business environment and firm innovation using World Bank indicators in an emerging market context, providing novel insights into the unique dynamics of legal, financial and administrative sub-environments.
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Donghua Zhao, Gaohan Zhu, Jiapeng He and Weizhong Guo
With the development of 3D printing or additive manufacturing (AM), curved layer fused deposition modeling (CLFDM) has been researched to cope with the flat layer AM inherited…
Abstract
Purpose
With the development of 3D printing or additive manufacturing (AM), curved layer fused deposition modeling (CLFDM) has been researched to cope with the flat layer AM inherited problems, such as stair-step error, anisotropy and the time-cost and material-cost problems from the supporting structures. As one type of CLFDM, cylindrical slicing has obtained some research attention. However, it can only deal with rotationally symmetrical parts with a circular slicing layer, limiting its application. This paper aims to propose a ray-based slicing method to increase the inter-layer strength of flat layer-based AM parts to deal with more general revolving parts.
Design/methodology/approach
Specifically, the detailed algorithm and implementation steps are given with several examples to enable readers to understand it better. The combination of ray-based slicing and helical path planning has been proposed to consider the nonuniform path spacing between the adjacent paths in the same curved layer. A brief introduction of the printing system is given, mainly including a 3D printer and the graphical user interface.
Findings
The preliminary experiments are successfully conducted to verify the feasibility and versatility of the proposed and improved slicing method for the revolving thin-wall parts based on a rotary 3D printer.
Originality/value
This research is early-stage work, and the authors are intended to explore the process and show the initial feasibility of ray-based slicing for revolving thin-wall parts using a rotary 3D printer. In general, this research provides a novel and feasible slicing method for multiaxis rotary 3D printers, making manufacturing revolving thin-wall and complex parts possible.
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Bolun An, Jiapeng Liu, Guang Yang, Feng shou Liu, Tong Shi and Ming Zhai
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…
Abstract
Purpose
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.
Design/methodology/approach
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.
Findings
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.
Originality/value
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.
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Akram Bedeoui, Riadh Ben Hadj, Moncef Hammadi and Nizar Aifaoui
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…
Abstract
Purpose
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.
Design/methodology/approach
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.
Findings
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.
Originality/value
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.