Zeng Huawei, Wang Chengtao, Qiao Jie, Zhang Bingjing, Zhao Bing and Dai Chuangyun
The Monascus pigment has been widely applied in the food processing industry as a functional additive. Lovastatin and polysaccharides are two important bio-active materials found…
Abstract
Purpose
The Monascus pigment has been widely applied in the food processing industry as a functional additive. Lovastatin and polysaccharides are two important bio-active materials found in Monascus. Citrinin is considered as mycotoxin. Thus, it is important to produce high yields of intracellular Monascus pigments with high yields of lovastatin and polysaccharides, while maintaining low citrinin yields under liquid fermentation.
Design/methodology/approach
The intracellular yields of pigments, lovastatin, polysaccharides and citrinin; biomass; and reducing the sugar content of Monascus purpureus HBSD 08 were determined every day during a 10-day culturing period using lactose, maltose, sucrose, glucose, glycerine and xylose as the sole carbon sources. Additionally, the pigment composition was analysed by a thin layer chromatography (TLC) and the in vitro antitumor activities of the pigments were determined.
Findings
The maximal yield of pigments (55.44 U/mL after six days of culture) and lovastatin content (1,475.30 µg/L after five days of culture) were obtained in the presence of glucose and maltose as the sole carbon sources, respectively. The suitable carbon sources for high intracellular polysaccharides yields were sucrose, maltose and xylose. Glucose should not be chosen as the sole carbon source because of its high food safety risk. In vitro antitumor activities of pigments in the presence of different carbon sources were in the order of xylose > glucose = maltose > glycerine > sucrose = lactose. The pigment compositions in the presence of different carbon sources were the same from the TLC analysis. Thus, maltose displayed high intracellular yields of pigments, lovastatin and polysaccharides; high food safety against citrinin, and high in vitro antitumor activity during the ten days culturing period.
Originality/value
This study shows us the benefits of using maltose as a substrate in the production of intracellular Monascus pigments while ensuring economic and food safety.
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Huawei Zeng, Qiao Jie, Zeng Xin, Xu Dayong, Xiong Minghua, Li Feng, Sun Jianfan, Jiang Xuan and Dai Chuanyun
Monascus pigment was widely applied in food processing industry as functional additive, so more attention was paid to the fermentation optimization of pigment production…
Abstract
Purpose
Monascus pigment was widely applied in food processing industry as functional additive, so more attention was paid to the fermentation optimization of pigment production. Therefore, this paper aims to evaluate the best possible fermentative conditions for maximum production of biopigment using submerged fermentation (SFM) and solid state fermentation (SSF) by Monascus purpureus HBSD 08.
Design/methodology/approach
The biopigment was produced by using an SMF and an SSF with optimized substrate to achieve higher yield. The antioxidant activity was evaluated by DPPH radical scavenging ability, superoxide anion radical scavenging ability and hydroxyl radical scavenging ability. The pigment composition was analyzed by thin layer chromatography.
Findings
Maximum Monascus pigment production (79.6 U/ml and 1,102 U/g) were obtained under an SFM and an SFF. The antioxidant activity of the pigment in an SFM was significantly higher than that in an SFM. The composition of pigment was not different in an SFM and an SFF.
Originality/value
The study developed new conditions, and Monascus strain was a candidate for producing pigment in an SFM and an SFF. To the authors’ best knowledge, this is a first attempt toward comparative evaluation on antioxidant capacity and composition between pigment in an SSF and an SFM. This result will serve for Monascus pigment production.
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Abstract
Purpose
Flow force is one of the crucial factors affecting the performance of conical throttle valves. The purpose of this paper is to determine the relationship between the flow force and operating parameters of the conical throttle valve.
Design/methodology/approach
The flow force of the throttle valve can be obtained by the difference between the axial force and static pressure on the valve spool. In this paper, the internal fluid is divided into two regions and the axial force and static pressure are obtained, respectively. In addition, a two-dimensional axisymmetric simulation model and experimental test are carried out to validate the results of the flow force.
Findings
It can be seen that the theoretical, simulation and experimental results exhibit high agreement with each other and the error between them decreases with the increase in the size of the opening. The curves of pressure distribution reveal that the pressure on the spool first decreases then increases when it reaches the minimum pressure at the orifice. Additionally, the minimum pressure decreases with the increase of opening and pressure difference. The results also indicate that the increase in the size of the opening and inlet pressure has a positive effect on the flow force. However, the increase in outlet pressure has a negative effect on the flow force.
Originality/value
In this paper, the flow force calculation model of conical throttle valve is established and the influence of operating parameters on the flow force of conical throttle valve is studied.
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Guisheng Gan, Hao Yang, Jie Luo, Yongchong Ma, Jiajun Zhang, Xin Liu, Qiao He, Leqi Li and Dayong Cheng
The purpose of this study was to investigate the effects of aging time on the microstructure, mechanical properties and fracture morphology of Cu/Zn160%SAC0307/Al solder joints…
Abstract
Purpose
The purpose of this study was to investigate the effects of aging time on the microstructure, mechanical properties and fracture morphology of Cu/Zn160%SAC0307/Al solder joints produced through solid-state bonding.
Design/methodology/approach
Zn particles with a size of 1 µm and Sn-0.3Ag-0.7Cu (SAC0307) particles ranging from 20 to 38 µm were used to achieve Cu/Al micro-connections using ultrasonic assistance at a temperature of 180 °C, followed by aging treatment at 150 °C to enhance the quality of Cu/Al joints. Scanning electron microscopy was used for observing and analyzing the solder seam, interface microstructure, and fracture morphology. The structural composition was determined using energy dispersive spectroscopy, while a PTR-1102 bonding tester was used to measure the average shear strength.
Findings
The results indicated that the intermetallic compounds formed at the interface between Cu substrates and solder metal primarily consisted of smooth Cu5Zn8. The Al-side interface mainly comprises an Al-Sn-Zn solid solution, with Zn-Sn-Cu phases forming between SAC0307 particles at 180 °C. During the aging process, atomic diffusion was accelerated, leading to improved connection quality. The shear strength of the joints initially increased before decreasing as aging time progressed; it peaked at 32.92 MPa after 24 h – an increase of 76.8% compared to as-received joints. After reaching stability at 96 h, there was still a notable increase in shear strength by 48.4% relative to as-received joints.
Originality/value
This study further explores the strengthening mechanisms associated with solid-state bonded Cu/SACZ/Al joints through aging processes. Joints created via solid-state bonding demonstrate superior reliability compared to traditional soldered connections. It is anticipated that insights gained from this research will contribute valuable knowledge toward developing low-temperature soldering methodologies for heterogeneous materials.
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Yaming Wang, Jie Han, Junhai Li and Chunlan Mou
This research is aimed to examine how environmental pollution affects consumers' preference for self-improvement products.
Abstract
Purpose
This research is aimed to examine how environmental pollution affects consumers' preference for self-improvement products.
Design/methodology/approach
Through a series of three experimental studies, this research substantiates our hypotheses by employing various manipulations of environmental pollution and examining different types of self-improvement products.
Findings
The research demonstrates that environmental pollution enhances consumers' preference for self-improvement products via the mediation of perceived environmental responsibility. And the effect is negatively moderated by social equity sensitivity.
Originality/value
The recurrent incidence of environmental pollution has elicited significant concern among the general public and academic scholars. An overwhelming majority of research examining the impact of pollution on consumer behavior has concentrated on its influence on environmentally friendly and healthy consumption patterns. Nevertheless, the current research proposes that pollution fosters a preference for products associated with self-improvement, mediated by perceived environmental responsibility, with the effects being moderated by social equity sensitivity.
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Abstract
Purpose
The purpose of this study is to reveal the mechanism of peer abusive supervision on bystander behavior based on the perspective of bystander from two different paths of bystander empathy and bystander hostility toward supervisor. At the same time, it discusses the moderation effect of bystander traditionality on the two paths.
Design/methodology/approach
This study conducted a three-wave longitudinal survey. The data were collected from 454 employees and their coworkers in several Chinese enterprises. The authors used Mplus 7.4 and adopted a bootstrapping technique in the data analysis.
Findings
Peer abusive supervision leads bystanders to empathize with the abused colleague and thus exhibit more organizational citizenship behaviors, and peer abusive supervision also induces bystanders to develop hostility toward the abusive supervisor and thus produce more workplace negative gossip behaviors. In addition, it is found that bystander traditionality has a moderation effect in the process by which peer perceptions of abusive supervision influence bystander empathy and bystander hostility.
Originality/value
Based on Affective Events Theory, this study explores the mechanism of colleague perception of abusive supervision on bystander behavior from a bystander perspective. The results of this study not only provide a more comprehensive expansion of the weighting factors in the influence mechanism of abusive supervision but also provide new ideas for organizations to reduce the negative effects of workplace abusive behaviors.
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Zuhui Xu, Bin Li, Zhiyang Liu and Jie Wu
Research on entrepreneurship toward poverty reduction has outlined how micro-level characteristics of entrepreneurs capture entrepreneurial opportunities in settings of poverty;…
Abstract
Purpose
Research on entrepreneurship toward poverty reduction has outlined how micro-level characteristics of entrepreneurs capture entrepreneurial opportunities in settings of poverty; however, little is known about the influence of previous military experience in this context. This paper investigates how previous military experience influences poverty-reduction entrepreneurship.
Design/methodology/approach
This study uses data from two main sources. First, individual-level and firm-level information come from a nationwide survey of founders of private enterprises. Second, province-level information is taken from the Marketization Index and the China Statistics Yearbook. An analysis of the Logit moderation model renders strong support for our conjectures.
Findings
Via novel integration of imprinting theory and research on previous military experience, we propose that entrepreneurs with previous military experience have a strong sense of self-sacrifice, and as a result, are better able to participate in poverty-reduction entrepreneurship. In addition, we build on the resource availability and stakeholder expectations arguments and predict that the main effect of previous military experience on poverty-reduction entrepreneurship will be strengthened by reduced corporate philanthropy and increased government intervention.
Originality/value
Our study adds to the extant literature in the following ways. First, it enriches the literature on entrepreneurship toward poverty reduction. Second, it contributes to imprinting theory in the entrepreneurial field. Third, it adds knowledge to the social entrepreneurship literature.
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Yang Liu, Ziyu Chen, Jie Gao, Shuai Gan and Erlong Kang
Compared with the robotic manipulation in structured environment, high performance assembly of complex parts in extreme special environment is facing great challenges because of…
Abstract
Purpose
Compared with the robotic manipulation in structured environment, high performance assembly of complex parts in extreme special environment is facing great challenges because of the uncertainty in the environment, and the decline of the control accuracy of the robot and the sensor accuracy. The assembly and construction of the space station is a typical case. An important step in the construction of the space station is the module positioning and docking with the auxiliary of the space manipulator. The operation of the manipulator is faced with many problems, such as low sensing information accuracy, large end position deviation and the requirement of weak impact in the docking process. The purpose of this paper is to design a docking method at the strategy level to effectively solve the problems that may be faced in the docking process.
Design/methodology/approach
Inspired by the research of robotic high-precision compliant assembly, this paper introduces the concept of Attractive Region in Environment (ARIE) into the space manipulator–assisted module docking. The contact configuration space of the docking mechanism and the existence of ARIE are systematically analyzed. The docking strategy based on ARIE framework is proposed, in which the impedance control is used to ensure the weak impact during the docking process.
Findings
For the androgynous peripheral spacecraft docking mechanism, a large range of attractive region exists in the high-dimensional contact configuration space. The docking strategy based on ARIE framework can be designed according to the geometric characteristics of the constraint region and the structural characteristics of the docking mechanism. The virtual models and the simulation environment are established, and the effectiveness of the proposed method is preliminarily verified.
Originality/value
Based on the research results of robotic precision compliant manipulation, in this paper, the theory of ARIE is first systematically applied to the analysis of spacecraft docking problem and the design of docking scheme. The effectiveness of the proposed docking method is preliminarily verified for the requirements of large position tolerance and weak impact. The research results will provide theoretical support and technical reference for the assembly and construction of space station and other space manipulator operations.
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This study investigates whether listed firms using equity incentive plans (EIPs) adopt more conservative accounting in China's unique corporate setting.
Abstract
Purpose
This study investigates whether listed firms using equity incentive plans (EIPs) adopt more conservative accounting in China's unique corporate setting.
Design/methodology/approach
Based on a sample of 2,243 listed firms and 9,950 firm-year observations for the period of 2008–2017, this study employs piecewise cross-sectional regression models with year and industry fixed effects to examine the associations proposed in the research hypotheses.
Findings
This study finds a positive relationship between the adoption of EIPs and accounting conservatism in listed Chinese firms. Further analyses reveal that this positive relationship is more pronounced when listed Chinese firms use restricted stock units (RSUs), instead of stock options, in their EIPs.
Research limitations/implications
Unlike many early studies, this paper empirically investigates the impacts of two different types of equity incentives – stock options and RSUs – and thus contributes to accounting and corporate governance literature by providing a better understanding of the impacts of different types of equity incentives on financial reporting quality. However, this study does not consider other alternative equity incentive measurements because of the limited data regarding Chinese firm's executive compensation.
Practical implications
This study offers investors and policymakers in China some insight into how accounting conservatism in listed firms might be shaped by equity incentives used in their managerial compensation schemes.
Originality/value
This study is one of the few that examines the effects of using equity incentives in a large emerging market. It offers support for the view that the recent introduction of policies on EIPs by the Chinese government has an overall positive impact on listed firm's financial reporting quality, as reflected by greater degrees of accounting conservatism.
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Wenyuan Huang, Jie Shen, Chuqin Yuan and Min Li
How to foster voice behavior has always been a hot topic in organizational research; however, the mechanism through which performing decent work affects employee voice behavior…
Abstract
Purpose
How to foster voice behavior has always been a hot topic in organizational research; however, the mechanism through which performing decent work affects employee voice behavior remains to be fully understood. To address this deficiency, the current study investigates how basic need satisfaction may relate to perceived decent work and voice behavior and the moderating role of gender. Our research draws upon self-determination theory and social information processing theory.
Design/methodology/approach
The theoretical model was tested using two-wave investigation data collected from a sample of 349 employees and 85 supervisors in Southwest China.
Findings
Decent work perception was positively related to voice behavior, and this relationship was partially mediated by basic need satisfaction. In addition, the relationship between decent work perception and basic need satisfaction as well as the indirect effect of decent work perception on voice behavior via basic need satisfaction was stronger for men than for women.
Originality/value
This study highlights the pivotal roles of basic need satisfaction and gender in the consequences of decent work perception in the workplace. The authors provide new insights into the relationship between decent work perception and voice behavior and inspire scholars to elucidate other explanatory mechanisms in this link.