Yunfeng Liu, Wenqing Liao, Guangsheng Jin, Quanming Yang and Wei Peng
– The purpose is to realize precise apicoectomy with less surgical risk and improved quality and efficiency.
Abstract
Purpose
The purpose is to realize precise apicoectomy with less surgical risk and improved quality and efficiency.
Design/methodology/approach
First, the procedure of precise apicoectomy based on additive manufacturing (AM) and digital design is proposed. With CT images of the patient's oral, a 3D model of alveolar bone and teeth is reconstructed, and based on this model, the infected tissue and enclosed root tip can be determined. Thus, a surgical plan can be created based on clear anatomical relationships and minimal negative constraints, which will then determine the drill position, direction and depth, as well as the resection length of root tip. With this plan, a surgical guide design is performed via a composite model from reversed plaster models and hard tissue models from CT, and accessory tools including drill with stop plane and handle are also selected. With the surgical guide, the virtual plan in the computer can be realized in the clinic.
Findings
With this methodology, the dentist can perform root-end resection with greater accuracy, save more than 30 percent of operatory time, and the discomfort to the patient is reduced to a minimum.
Practical implications
The proposed methodology has been used in ten cases for root-end resections. In fact, this method of designing a computer-based treatment plan with a 3D model of a patient and applying it in the clinic through guiding tools can be used in other surgeries, such as orthognathic surgery or osteotomy.
Originality/value
This case report illustrates that with AM and digital design methods, optimal operational plans can be designed and realized for apicoectomy, and the quality and efficiency of clinical surgery are greatly improved compared with conventional methods.
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Cheng Zhang, Cheng Peng, Jin Huang, Yanchun Zhao, Guangsheng Huang, Liang Wu, Guangang Wang and Hua Zhang
The influence of Zn concentration on microstructure and corrosion performance of the Mg–xZn alloys microalloyed with Ca and Ce was investigated through optic microscopy, scanning…
Abstract
Purpose
The influence of Zn concentration on microstructure and corrosion performance of the Mg–xZn alloys microalloyed with Ca and Ce was investigated through optic microscopy, scanning electron microscopy, hydrogen evolution, dynamic polarization and electrochemical impedance spectroscopy experiments.
Design/methodology/approach
In this paper, Mg–xZn alloys (x = 0.5∼2.0 Wt.%) microalloyed with Ca and Ce (0.2 Wt.% each) were prepared.
Findings
As the increase of Zn concentration, the number of second phase particles (Mg-Zn-Ca, Mg-Zn-Ce and Mg-Ce phases) increased, and when the Zn concentration increased to 2.0 Wt.%, the new second phase Mg-Zn phase was precipitated.
Originality/value
The influence of Zn concentration on corrosion mechanism of Mg-xZn alloys microalloyed with Ca and Ce was revealed. Increasing of the Zn concentration resulted in the intensification of galvanic corrosion. When Zn concentration was 0.5 Wt.%, the alloy showed the lowest corrosion rate (0.61 mm y-1), which was about 1/2 of that of Mg-2.0Zn-0.2Ca-0.2Ce alloy.
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Cheng Zhang, Cheng Peng, Jin Huang, Yanchun Zhao, Tingzhuang Han, Guangang Wang, Liang Wu and Guangsheng Huang
This study aims to investigate the effect of microalloyed Ca and Ce on microstructure and corrosion behavior of Mg-1.5Zn alloy. Mg-1.5Zn-xCa-xCe alloys were prepared by melting…
Abstract
Purpose
This study aims to investigate the effect of microalloyed Ca and Ce on microstructure and corrosion behavior of Mg-1.5Zn alloy. Mg-1.5Zn-xCa-xCe alloys were prepared by melting, extrusion and rolling processes.
Design/methodology/approach
The effects of adding Ca and Ce elements alone or adding Ca and Ce elements simultaneously on the microstructure and corrosion resistance of Mg-1.5Zn-xCa-xCe (x = 0 or 0.2 Wt.%) alloys were studied by scanning electron microscopy, hydrogen evolution tests and electrochemical experiments.
Findings
The addition of Ca and Ce elements alone or the addition of Ca and Ce elements had little impact on the grain size of the rolled and annealed Mg-1.5Zn-xCa-xCe alloy, but had a greater effect on the type and quantity of the second phase.
Originality/value
The order of the corrosion rates for the three alloys was Mg-1.5Zn-0.2Ca < Mg-1.5Zn-0.2Ca-0.2Ce < Mg-1.5Zn-0.2Ce. Mg-1.5Zn-0.2Ca showed the best corrosion resistance, which was related to the second phase and corrosion products.
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Guangsheng Zhang, Xiao Wang, Yanling Wang and Junqian Xu
Although green logistics has become a new focus of cooperation between government and enterprises under environmental constraints, how local governments formulate subsidy policies…
Abstract
Purpose
Although green logistics has become a new focus of cooperation between government and enterprises under environmental constraints, how local governments formulate subsidy policies to effectively guide the green transformation of regional logistics and how to facilitate the reasonable cost-sharing are rather critical. This paper will deeply explore the dynamic process of the tripartite participation (government, platform, and logistics enterprises) in the selection of regional green logistics strategy, and reveal the evolutionary game relationship of the three parties.
Design/methodology/approach
To explore the dynamics involving the government, platform and logistics enterprises for the green logistic transformation, and reveal the evolutionary gaming among the three parties, based on the bounded rationality premise, this study constructs the tripartite asymmetric evolutionary game models, uses the stability theorem of differential equation to explore the evolution and stability strategy of the system in different cases and explicates the paths of influence on the tripartite behaviors via simulations.
Findings
Results of this study indicate that there exist stable equilibrium strategies among the three parties regarding the regional green logistics, and they are affected by different factors. The government's subsidy, subsidy intensity and the platform's cost-sharing proportion can generate positive effects, but the latter two can also impact negatively beyond the effective ranges. The findings provide a theoretical basis for local governments, platforms and logistics enterprises to formulate justifiable subsidy intensity and determine reasonable sharing proportion.
Originality/value
Firstly, considering the significant relevance of local government, it is included in the evolution model, and the tripartite game (among government, platform and enterprises) is explored; Secondly, by comparing the equilibrium results under different game conditions, this paper analyzes the evolution of each party's game strategy to achieve the optimal return under bounded rationality and the important factors determining the strategic selection; Finally, the key factor of platform cost sharing is involved, and to what extent the change of platform cost sharing ratio will influence the systematic stability is explored.
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Jie Yang, Hongming Xie, Guangsheng Yu and Mingyu Liu
The purpose of this paper is to investigate whether responsible purchasing (relational commitment and supplier evaluation) and responsible supply (supplier firm information…
Abstract
Purpose
The purpose of this paper is to investigate whether responsible purchasing (relational commitment and supplier evaluation) and responsible supply (supplier firm information sharing and supplier performance) affect the two factors of supply chain responsiveness including process efficiency and customer knowledge management capability, which, in turn, affect other three factors of supply chain responsiveness, such as dyadic quality performance, innovation capability and buyer‒supplier relationship improvement.
Design/methodology/approach
This study used questionnaire survey and statistical analytical methods. Employing path analysis, this study tested hypothesized relationships using data collected from manufacturers.
Findings
The findings of this study support the theorized links. Responsible purchasing and supply enhance supply chain responsiveness, which is reflected through process efficiency, customer knowledge management capability, dyadic quality performance, innovation capability and buyer‒supplier relationship improvement.
Originality/value
Grounded in the goal interdependence theory, this study investigates the effects of responsible purchasing and supply on supply chain responsiveness in the context of Chinese manufacturers. This study offers managerial implications and theoretical contribution.
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Xuetao Sun, Yu Zhao and Guangsheng Zhang
China’s overall grain production efficiency is currently relatively low, and how to improve it is key to high-quality grain development. High-standard farmland construction fills…
Abstract
Purpose
China’s overall grain production efficiency is currently relatively low, and how to improve it is key to high-quality grain development. High-standard farmland construction fills the gaps in grain production, providing a path for improving comprehensive grain production capacity.
Design/methodology/approach
This paper analyzes grain production data from 281 Chinese cities and uses the meta-Malmquist index to calculate total factor productivity (TFP) of grain and the spatial autoregressive model with spatial error (SARAR) model to analyze the impact of high-standard farmland construction on TFP of grain. Finally, it tests the model for robustness and heterogeneity.
Findings
TFP of grain has room for improvement, and technological efficiency has a greater impact on it than technological progress. TFP of grain in the eastern region is significantly higher than that in central and western regions. High-standard farmland construction can significantly improve TFP and technology efficiency of grain, and its economic benefits are directly affected by the differences in regional grain economic development. High-standard farmland construction improves TFP of grain through agricultural mechanization, and its impact is heterogeneous; TFP of grain in the (poor, plain) eastern region is more likely to share its benefits.
Originality/value
This paper evaluates whether high-standard farmland construction has achieved its purpose of enhancing comprehensive grain production capacity. It offers novel insights into elevating element quality and comprehensive grain production capacity, provides a theoretical reference from the perspective of element quality and draws corresponding policy implications for high-standard farmland.
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Heng Liu, Yonghua Lu, Haibo Yang, Lihua Zhou and Qiang Feng
In the context of fixed-wing aircraft wing assembly, there is a need for a rapid and precise measurement technique to determine the center distance between two double-hole…
Abstract
Purpose
In the context of fixed-wing aircraft wing assembly, there is a need for a rapid and precise measurement technique to determine the center distance between two double-hole components. This paper aims to propose an optical-based spatial point distance measurement technique using the spatial triangulation method. The purpose of this paper is to design a specialized measurement system, specifically a spherically mounted retroreflector nest (SMR nest), equipped with two laser displacement sensors and a rotary encoder as the core to achieve accurate distance measurements between the double holes.
Design/methodology/approach
To develop an efficient and accurate measurement system, the paper uses a combination of laser displacement sensors and a rotary encoder within the SMR nest. The system is designed, implemented and tested to meet the requirements of precise distance measurement. Software and hardware components have been developed and integrated for validation.
Findings
The optical-based distance measurement system achieves high precision at 0.04 mm and repeatability at 0.02 mm within a range of 412.084 mm to 1,590.591 mm. These results validate its suitability for efficient assembly processes, eliminating repetitive errors in aircraft wing assembly.
Originality/value
This paper proposes an optical-based spatial point distance measurement technique, as well as a unique design of a SMR nest and the introduction of two novel calibration techniques, all of which are validated by the developed software and hardware platform.