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Article
Publication date: 13 June 2019

Rui Zhang, Lei Zhao, Dan Xie, Jinlong Song, Wendong Zhang, Lihu Pan and Yanhua Zhang

This study aims to simulate and test the performance of a transmitting and receiving capacitive micro-machined ultrasonic transducer (CMUT). Aimed at detecting demand of…

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Abstract

Purpose

This study aims to simulate and test the performance of a transmitting and receiving capacitive micro-machined ultrasonic transducer (CMUT). Aimed at detecting demand of the CMUT, a matched integrated adjustment circuit was designed through analyzing processing methods of transducer’s weak echo signal.

Design/methodology/approach

Based on the analysis of CMUT array structure and work principle, the CMUT units are designed and the dynamic performance analysis of SIMULINK is given according to the demand of underwater detecting. A transceiver isolation circuit is used to make transmission mode and receiving mode separate. A detection circuit is designed based on the transimpedance amplifier to achieve extraction of high-frequency and weak signal.

Findings

Through experimentation, the effectiveness of the CMUT performance simulation and the transceiver integrated adjustment circuit were verified. In addition, the test showed that CMUT with 400 kHz frequency has wider bandwidth and better dynamic characteristics than other similar transducers.

Originality/value

This paper provides a theoretical basis and design reference for the development and application of CMUT technology.

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Article
Publication date: 6 March 2017

Zhibang Qiao, Shanshan Lv, Jiyou Gu, Haiyan Tan, Junyou Shi and Yanhua Zhang

The purpose of this paper is to obtain high-solids-content and low-viscosity starch adhesive, and improve bonding strength of the pure starch adhesive.

Abstract

Purpose

The purpose of this paper is to obtain high-solids-content and low-viscosity starch adhesive, and improve bonding strength of the pure starch adhesive.

Design/methodology/approach

Maize starch was treated by hydrochloric acid solution with different concentrations, and acid-thinned starch adhesive was prepared. Polyisocyanate as a crosslinking agent was added to improve water resistance of the pure starch adhesive.

Findings

The physical and chemical properties of the acid-thinned starch adhesive were characterised. Acid hydrolysis did not change structure of starch granules, but increased its crystallinity. After acid modification, starch granules became less smooth and some fragments appeared. Acid treatment had little influence on thermal stability of starch, when acid hydrolysis was not strong. High concentration of HCl solution led to starch granules being destroyed, resulting in decrease in bonding strength. The optimal HCl concentration was 0.5 mol/L. Polyisocyanate addition was beneficial to improve the bonding strength of the acid-thinned starch adhesive.

Research limitations/implications

Acid hydrolysis changed the properties of the starch adhesive.

Practical implications

Acid hydrolysis decreased viscosity of the starch adhesive and improved its solids content, which had a positive effect on the application of the starch adhesive.

Social implications

It was helpful to develop an environment-friendly, natural polymer-based wood adhesive.

Originality/value

The properties of acid-thinned starch and acid-thinned starch adhesive were studied.

Details

Pigment & Resin Technology, vol. 46 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 May 2019

Bo Wang, Yanhua Zhang, Haiyan Tan and Jiyou Gu

The purpose of the study was to prepare melamine-urea-formaldehyde (MUF) resin that would be resistant to boiling water and high temperature and exhibit low formaldehyde emission.

Abstract

Purpose

The purpose of the study was to prepare melamine-urea-formaldehyde (MUF) resin that would be resistant to boiling water and high temperature and exhibit low formaldehyde emission.

Design/methodology/approach

The authors prepared MUF resin with different F/(M + U) and changed the amount of melamine added, through the analysis of MUF resin properties to get the best reaction parameters, and used different amino acid cure systems including NH4Cl cured the resin.

Findings

Resin’s heat resistance and water resistance are mainly determined by the amount of melamine added, and formaldehyde emission of the plywood can be changed by adjusting F/(M + U). The peak temperature of the curing agent-cured resin increases as compared with the self-curing resin. Stronger the acidity of curing agent, faster the viscosity increased in probation period and lower the bonding strength and heat resistance of the resin.

Research limitations/implications

Melamine improves the heat resistance and water resistance of the resin. When the amount of melamine is more than a certain value, water resistance of the resin decreased.

Practical implications

MUF resin that is resistant to boiling water and exhibits low formaldehyde emission can be used in high temperature, high humidity and strict formaldehyde emission environment and can also be combined with other materials.

Social implications

It was helpful to reduce the effect of formaldehyde emission on people’s health and environmental pollution and is also beneficial for the expansion of the application range of aldehyde resin.

Originality/value

The originality is twofold: the influence of the acid strength of curing agent on the bonding strength of the resin adhesive and the method for preparing high performance MUF resin by following the traditional process.

Details

Pigment & Resin Technology, vol. 48 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 16 February 2021

Yi Zhang and Hao Dong Gu

Scholars have examined the relationship between sports and urban development and proposed to use sport programs and events as a catalyst to revitalize communities, upgrade…

Abstract

Purpose

Scholars have examined the relationship between sports and urban development and proposed to use sport programs and events as a catalyst to revitalize communities, upgrade urban infrastructure, promote city image, shift economic structure, nurture an active lifestyle, and enhance societal harmony and solidarity. Yet, previous studies were usually focused on mega sport events and were typically conceptual, theoretical and lack of practical applications. This study was designed to attain in-depth understanding on how a specific sport, table tennis, can be systematically organized and utilized to influence urban development through a qualitative research injury.

Design/methodology/approach

This investigation was carried by conducting in-depth interviews of the executive director of the Shanghai Table Tennis Association, on-site observations and comprehensive review of literature. Development of interview questions took into consideration the conceptual framework postulated by Preuss (2007) that contains six structures of urban development through sports. Triangulation analyses were conducted to cross validate the three information sources to generate themes and assertions.

Findings

While the identified practices were consistent with Preuss' (2007) framework, specific management activities earnestly practiced in Shanghai are centered on utilizing cultural and historical heritage, star power, branding strategies, staging tournaments, hallmark events, technical innovation and government relations to achieve the objectives of table tennis as a sport and the objectives of urban development through table tennis.

Originality/value

The findings of this study help fill the void that a theory usually cannot specify, namely, detailed, unambiguous practices. While table tennis may be a viewed as a small sport in many parts of the world, it has a strong, unprecedented historical heritage in Shanghai. This city has made a prudent choice and investment in this sport, which has proved to be effective. Other cities in the world should look into their own social, cultural and historical heritage and develop sport strategies, operations and programs accordingly.

Details

International Journal of Sports Marketing and Sponsorship, vol. 22 no. 1
Type: Research Article
ISSN: 1464-6668

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Article
Publication date: 8 November 2011

Yanhua Zhang, Jiyou Gu, Xiankai Jiang, Libin Zhu and Haiyan Tan

The purpose of this paper is to study the effective procedure for blocking and deblocking isocyanate by sodium bisulphite with special cosolvent and dropwise method.

Abstract

Purpose

The purpose of this paper is to study the effective procedure for blocking and deblocking isocyanate by sodium bisulphite with special cosolvent and dropwise method.

Design/methodology/approach

A number of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and Thermo gravimetric analyser (TGA) were employed to assess the reactions between isocyanates and sodium bisulphite, water, cosolvent, also the deblocking temperature of blocked isocyanates.

Findings

The blocked isocyanates reacted with sodium bisulphite, water and cosolvent via a special procedure. It was found that the − NCO functional groups of the isocyanates were completely blocked by sodium bisulphite and a new method for determining the lowest deblocking temperature of the blocked isocyanates was described. It was revealed that the deblocking temperature of blocked isocyanates by sodium bisulphite was lower than others.

Practical implications

The paper provides some useful information about the blocking and deblocking of isocyanate, which would be helpful for the preparation of blocking and deblocking isocyanate, and guiding the practical applications of blocked isocyanate.

Originality/value

The investigation found that the sodium bisulphite was a very efficient blocking agent for isocyanates at the room temperature via the special procedure developed. On the basis of emulsion polymerisation theory, polymer isocyanates were blocked by sodium bisulphite, which realised the new breakthrough effectively by means of controlled temperature, stirring speed and optimum dropwise speed in the whole reaction system. Meanwhile, the special cosolvent could improve the intermiscibility of isocyanate in sodium bisulphite aqueous solution, reduce the side reaction of isocyanate with water and accelerate reaction rate of isocyanate with sodium bisulphite. If no cosolvent was present, the blocked system would not be homogeneous.

Details

Pigment & Resin Technology, vol. 40 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 1 July 2014

Yanhua Zhang, Jun Cao, Haiyan Tan and Jiyou Gu

The mechanisms of the deblocking reaction of the polyurethane with blocking agent were investigated in detail relatively using thermogravimetric analysis (TGA), Fourier…

Abstract

Purpose

The mechanisms of the deblocking reaction of the polyurethane with blocking agent were investigated in detail relatively using thermogravimetric analysis (TGA), Fourier transform infrared spectrometry (FTIR) and X-ray photoelectron spectroscopy (XPS). This kind of method for polyurethane as the application of wood adhesives can provide the conditions of application and the main theoretical basis.

Design/methodology/approach

The blocking rate and latex particle size distribution were determined using the titrimetric analysis and the laser particle analysis, respectively. TGA, FTIR, XPS and differential scanning calorimetry were used to investigate the deblocking temperature and time of the blocked isocyanate in detail.

Findings

The results indicated that the blocking rate was approximately 97 per cent and the average particle size was 360 nm. The results of laser particle analysis have confirmed that the dispersivity of the blocked polyurethane emulsion was good. XPS results showed that the amount of –O = C-N-benzyl groups increased with an increasing deblocking temperature and subsequently reached equilibrium. In summary, the blocked isocyanate was deblocked at temperatures ranging from 50 to 90°C.

Research limitations/implications

An important approach in future wood adhesive work would be to gain access to man-made board application data.

Practical implications

The paper provided some useful information about deblocking mechanisms of blocked polyurethane that would be helpful to guide applied practical applications as wood adhesive.

Social implications

To promote China’s wood processing technology progress and solve the problem of shortage of the natural quality of wood is of important practical significance.

Originality/value

The paper is the first to use the XPS characterisation method to characterise deblocking polyurethane solution.

Details

Pigment & Resin Technology, vol. 43 no. 4
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 6 November 2017

Liqiang Zhao, Yanhua Zhu, Pingli Liu, Jian Zhang and Yigang Liu

This paper aims to describe the corrosion behavior and possibility of inhibition by corrosion inhibitor SA1-3 in acidizing solution (5 per cent hydrochloric acid [HCl…

Abstract

Purpose

This paper aims to describe the corrosion behavior and possibility of inhibition by corrosion inhibitor SA1-3 in acidizing solution (5 per cent hydrochloric acid [HCl] solution). The study aims to explain the mechanism of corrosion and inhibition of N80 steel in 5 per cent HCl solution to provide theoretical basis for expanding the range of application of N80 steel in acidification process.

Design/methodology/approach

This paper opted for a laboratory study using simulation of acidizing solution to do the experiments. The results of experiments including weight-loss method, electrochemical method and surface analysis were used to explain the mechanism of corrosion and inhibition so as to predict the dissolution progress of N80 steel in 5 per cent HCl solution with and without inhibitor SA1-3.

Findings

This paper provides theoretical insights about how to inhibit the corrosion behavior of N80 steel in 5 per cent HCl solution. It suggests that the corrosion inhibitor which can form a protective film on the steel surface should be used to expand the application of N80 steel in acidizing solution. The inhibitor SA1-3 is a kind of cathodic corrosion-controlling inhibitor which mainly inhibits cathode corrosion; it cannot change the corrosion mechanism of N80 steel.

Originality/value

This paper provides a theoretical basis for the corrosion behavior and inhibition mechanism of N80 steel in acidizing solution.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 2 January 2018

Yanhua Han

The purpose of this paper is to model the aircraft-cargo’s coupling dynamics during ultra-low altitude heavy cargo airdrop and to design the aircraft’s robust flight…

Abstract

Purpose

The purpose of this paper is to model the aircraft-cargo’s coupling dynamics during ultra-low altitude heavy cargo airdrop and to design the aircraft’s robust flight control law counteracting its aerodynamic coefficients perturbation induced by ground effect and the disturbance from the sliding cargo inside.

Design/methodology/approach

Aircraft-cargo system coupling dynamics model in vertical plane is derived using the Kane method. Trimmed point is calculated when the cargo fixed in the cabin and then the approximate linearized motion equation of the aircraft upon it is derived. The robust stability and robust H optimal disturbance restraint flight control law are designed countering the aircraft’s aerodynamic coefficients perturbation and the disturbance moment, respectively.

Findings

Numerical simulation shows the effectiveness of the proposed control law with elevator deflection as a unique control input.

Practical implications

The model derived and control law designed in the paper can be applied to heavy cargo airdrop integrated design and relevant parameters choice.

Originality/value

The dynamics model derived is closed, namely, the model can be called in numerical simulation free of assuming the values of parachute’s extraction force or cargo’s relative sliding acceleration or velocity as seen in many literatures. The modeling is simplified using Kane method rather than Newton’s laws. The robust control law proposed is effective in guaranteeing the aircraft’s flight stability and disturbance restraint performance in the presence of aerodynamic coefficients perturbation.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 1
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 2 March 2015

Biao Xie, Liyuan Wang, Hao Yang, Yanhua Wang and Mingli Zhang

In response to food scares related to high levels of agro-chemical residues sometimes found on foods, consumers in China increasingly demand for organic foods. As little…

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Abstract

Purpose

In response to food scares related to high levels of agro-chemical residues sometimes found on foods, consumers in China increasingly demand for organic foods. As little is known on consumer perceptions and attitudes toward organic food products, the purpose of this paper is to gain insight into the purchase of organic food products by consumers and to explore the main factors driving this process.

Design/methodology/approach

Mixed (quantitative and qualitative) market survey approaches were used to provide a potentially deeper insight into consumer’s perspective and could help get a better picture of the complex factors involved.

Findings

The main trigger for purchasing organic food products is that consumers expect them to be healthier and safer. The respondents who have bought organic food products tend to have a higher education level and disposable incomes, be families with children and be older than those who have not bought them. The main barriers to increasing the market share of organic food products are the consumers’ lack of knowledge, the relatively high price premium and the lack of availability of organic food products. Informing consumers about unique characteristics of organic production methods, the decline in the prices of and increasing the availability of organic food products to its customers might be a promising strategy to develop the market for organic food products.

Originality/value

This paper provides a unique insight into buying behavior and attitudes of organic consumers in China. The results of the research could provide information for the organic food industry to expand its market and improve its profitability and reliability.

Details

British Food Journal, vol. 117 no. 3
Type: Research Article
ISSN: 0007-070X

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Book part
Publication date: 10 November 2016

R. Greg Bell, Abdul A. Rasheed and Sri Beldona

To date there is little understanding of the factors that impact the survival of foreign IPOs after they list on US stock exchanges. In this study, we examine how foreign…

Abstract

To date there is little understanding of the factors that impact the survival of foreign IPOs after they list on US stock exchanges. In this study, we examine how foreign IPO survival is contingent on institutional factors associated with the firm’s home country. We also explore how corporate governance and organizational identity influence the survival of foreign IPOs in the United States. Results suggest that the US institutional environment supports foreign firms with more independent and professional leadership, and that knowledge-intense organizations have higher chances of long-term success after listing on US exchanges.

Details

Global Entrepreneurship: Past, Present & Future
Type: Book
ISBN: 978-1-78635-483-9

Keywords

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