Wang Yu, Gang Chen, Haiyan Yang and Sisi Li
A series of sulfate-based Gemini anionic surfactants were synthesized via etherification, ring opening and sulfation reactions using epichlorohydrin, fatty alcohol, ethylene…
Abstract
Purpose
A series of sulfate-based Gemini anionic surfactants were synthesized via etherification, ring opening and sulfation reactions using epichlorohydrin, fatty alcohol, ethylene glycol and chlorosulfonic acid as the main raw materials. Orthogonal experiments for 1,8-bisalkoxymethylene-3,6-dioxin-1,8-octane disulfate were performed on the sulfation reaction to determine the optimal reaction conditions.
Design/methodology/approach
A series of sulfate-based Gemini anionic surfactants were synthesized via etherification, ring opening and sulfation reactions using epichlorohydrin, fatty alcohol, ethylene glycol and chlorosulfonic acid as the main raw materials. Orthogonal experiments for 1,8-bisalkoxymethylene-3,6-dioxin-1,8-octane disulfate were performed on the sulfation reaction to determine the optimal reaction conditions. The structures of the intermediate and final products were characterized by FT-IR (Fourier transform infrared spectroscopy analysis), 1H-NMR (proton nuclear magnetic resonance spectroscopy) methods. The thermal performance of surfactants was analyzed using thermogravimetric analysis (TGA). The thermogravimetric results showed that the sulfate-based Gemini surfactants had good heat resistance (the thermal decomposition temperature of which was in the range of 140∼170?). The Krafft point, surface tension, foaming, Hydrophile–Lipophile Balance Number (HLB), emulsifying, wetting, and lime-soap dispersing performance were measured by visual observation, hanging drop method, aqueous surfactant solution method and Borghetti–Bergman method, respectively. The results have shown that all the sulfate-based Gemini surfactants had good water solubility and lime-soap dispersing ability. When spacer group was -(CH2)2-, with the increase of the carbon chain length from C12 to C14, the micellar concentration critical micelle concentration and surface tension (CMC) gradually increased from 8.25 × 10–4 mol/L to 8.75 × 10–4 mol/L and 27.5 mN/m to 30.9 mN/m, respectively. Also, the sulfate-based Gemini surfactants with the different length of the spacer group had a different effect on their performance on foaming properties and foam properties, HLB and emulsifying ability and wetting ability.
Findings
In view of the important role of the spacer group and the general use of anionic surfactants in oil fields, this article considers the preparation of a series of sulfate-based Gemini surfactants by changing the spacer group and the chain length of the hydrophobic group and evaluating their surface activity, and finally its Kraffi, on the foam properties, HLB value, emulsifying performance, lime soap dispersing ability etc.
Originality/value
Sulfate-based Gemini surfactants have broad application prospects in the fields of oil and gas exploitation, environmental protection, chemistry and daily chemical industry and so on.
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The aim of this paper is to provide a narrative review of previous research on tourism demand modelling and forecasting and potential future developments.
Abstract
Purpose
The aim of this paper is to provide a narrative review of previous research on tourism demand modelling and forecasting and potential future developments.
Design/methodology/approach
A narrative approach is taken in this review of the current body of knowledge.
Findings
Significant methodological advancements in tourism demand modelling and forecasting over the past two decades are identified.
Originality/value
The distinct characteristics of the various methods applied in the field are summarised and a research agenda for future investigations is proposed.
目的
本文旨在对先前关于旅游需求建模和预测的研究进行叙述性回顾并对未来潜在发展进行展望。
设计/方法
本文采用叙述性回顾方法对当前知识体系进行了评论。
研究结果
本文确认了过去二十年旅游需求建模和预测方法论方面的重要进展。
独创性
本文总结了该领域应用的各种方法的独特特征, 并对未来研究提出了建议。
Objetivo
El objetivo de este documento es ofrecer una revisión narrativa de la investigación previa sobre modelización y previsión de la demanda turística y los posibles desarrollos futuros.
Diseño/metodología/enfoque
En esta revisión del marco actual de conocimientos sobre modelización y previsión de la demanda turística y los posibles desarrollos futuros,se adopta un enfoque narrativo.
Resultados
Se identifican avances metodológicos significativos en la modelización y previsión de la demanda turística en las dos últimas décadas.
Originalidad
Se resumen las características propias de los diversos métodos aplicados en este campo y se propone una agenda de investigación para futuros trabajos.
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Juan Liu, Wei Wei, Meiying Zhong, Yaqi Cui, Shuang Yang and Haiyan Li
This study aimed to bibliometrically and visually analyze and review hospitality and tourism marketing studies published from 2000–2020.
Abstract
Purpose
This study aimed to bibliometrically and visually analyze and review hospitality and tourism marketing studies published from 2000–2020.
Design/methodology/approach
A total of 3,942 articles collected from the databases of Social Science Citation Index (SSCI) and Science Citation Index Expanded (SCI-E) in the Web of Science (WoS) along with their references were used for analyses. The bibliometric software HistCiteTM and literature measurement visualization tools, VOSviewer and CiteSpace, were employed to analyze the selected articles.
Findings
The results of the study demonstrated top influential scholars and institutions, intellectual structure and emerging trends of the study topics, and future research opportunities in the field of hospitality and tourism marketing.
Research limitations/implications
First, academic influence of a scholar was evaluated by citations of his/her publications, which did not take the order of authorship into consideration. Second, this study was restricted to the English language journals. Third, other types of published documents related to the studied field such as review papers were not considered by this research.
Originality/value
In comparison to traditional qualitative analysis such as content analysis, bibliometric analysis is a more objective approach to vividly demonstrate trends and performance of a research field, offers unique insights for its advancement with wider inclusiveness of a larger amount of data.
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Doris Chenguang Wu, Haiyan Song and Shujie Shen
The purpose of this paper is to review recent studies published from 2007 to 2015 on tourism and hotel demand modeling and forecasting with a view to identifying the emerging…
Abstract
Purpose
The purpose of this paper is to review recent studies published from 2007 to 2015 on tourism and hotel demand modeling and forecasting with a view to identifying the emerging topics and methods studied and to pointing future research directions in the field.
Design/methodology/approach
Articles on tourism and hotel demand modeling and forecasting published mostly in both science citation index and social sciences citation index journals were identified and analyzed.
Findings
This review finds that the studies focused on hotel demand are relatively less than those on tourism demand. It is also observed that more and more studies have moved away from the aggregate tourism demand analysis, whereas disaggregate markets and niche products have attracted increasing attention. Some studies have gone beyond neoclassical economic theory to seek additional explanations of the dynamics of tourism and hotel demand, such as environmental factors, tourist online behavior and consumer confidence indicators, among others. More sophisticated techniques such as nonlinear smooth transition regression, mixed-frequency modeling technique and nonparametric singular spectrum analysis have also been introduced to this research area.
Research limitations/implications
The main limitation of this review is that the articles included in this study only cover the English literature. Future review of this kind should also include articles published in other languages. The review provides a useful guide for researchers who are interested in future research on tourism and hotel demand modeling and forecasting.
Practical implications
This review provides important suggestions and recommendations for improving the efficiency of tourism and hospitality management practices.
Originality/value
The value of this review is that it identifies the current trends in tourism and hotel demand modeling and forecasting research and points out future research directions.
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Haiyan Emma Lu, Andrew Potter, Vasco Sanchez Rodrigues and Helen Walker
The implementation of sustainable supply chain management (SCM) calls for an acknowledgement of uncertainty inherent in complex environment. Confucianist society forms social…
Abstract
Purpose
The implementation of sustainable supply chain management (SCM) calls for an acknowledgement of uncertainty inherent in complex environment. Confucianist society forms social networks in Confucianist society, called guanxi networks, influence economic behaviours and business practices in the workplace. The purpose of this study is to explore how these social networks influence the implementation of sustainable SCM. In doing so, this study aims to critically investigate the constructs of guanxi networks, their impact on flow of supply chain capital and how this leverages the implementation of sustainable SCM.
Design/methodology/approach
Two systematic literature reviews are conducted to understand the constructs of social networks in Confucianist culture and their impacts on the flow of supply chain capitals. The reviews also analyse evidence related to the economic, social and environmental practices to reveal the current state of the literature and research gaps. Propositions and a framework are developed to support future research in this area.
Findings
The constructs of ganqing, renqing, xinren and mianzi in guanxi networks have expanded the contexts of social networks in Western literature. Guanxi networks increase the flow of supply chain capital and generate trust between players, thus enhancing capabilities to implement sustainable SCM. Guanxi networks also create the mechanism of network governance with which to increase sustainable SCM implementation under the institutional logics of sustainability.
Research limitations/implications
The conceptual framework and justification are based on the reviews of current studies in the field. Future empirical study is encouraged to test the propositions, both in Confucianist culture and other countries with culture of social networks.
Originality/value
Social networks are socially constructed concepts. The constructs of guanxi networks revealed in this study have developed the knowledge of Western-based social network theory. Besides, arguments from a social network perspective provide an alternative answer to explain increased behavioural commitment and companies’ investment in sustainable SCM. This study helps practitioners understand the logic of this social norm and to use it to maximise their operation outputs, including sustainable SCM implementation.
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This paper aims to propose a technique based on cognitive assessments to quantify identified operational risks from the perspective of container shipping or logistics system…
Abstract
Purpose
This paper aims to propose a technique based on cognitive assessments to quantify identified operational risks from the perspective of container shipping or logistics system administrators. The results derived from the risk quantification could be used to prioritize risks as well as support the decision-making process in risk prevention and mitigation.
Design/methodology/approach
This paper identified container shipping operational risks (CSORs) from a logistics perspective. A multivariate risk evaluation mechanism by fuzzy rules Bayesian network (FRBN) was established. An improved two-level parameter set based on the failure mode and effects analysis (FMEA) was used to support the input extraction process. By feeding cognitive assessments into the model, the identified risks are evaluated based on their utility values. An illustration example and a sensitivity analysis were carried out to justify and validate the proposed model.
Findings
The highest positions in the prioritized list of CSORs in the case study are dominated by risks in the physical flow with the first three are piracy and terrorism, force majeure and port congestion. The results derived from the case study with the satisfaction of all pre-defined axioms proved the feasibility and illustrated the functionality of the proposed risk assessment and prioritization technique.
Originality/value
Controlling risk is irrefutably a significant issue of container shipping and logistics management because of the inconsistency of risk definitions and the involvement of uncertainties. The proposed risk evaluation mechanism and the identified list of CSORs could be beneficial in system management, decision-making and reliability performance.
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Li Zhang, Haiyan Fang, Weimin Bao, Haifeng Sun, Lirong Shen, Jianyu Su and Liang Zhao
X-ray pulsar navigation (XPNAV) is an autonomous celestial navigation technology for deep space missions. The error in the pulse time of arrival used in pulsar navigation is large…
Abstract
Purpose
X-ray pulsar navigation (XPNAV) is an autonomous celestial navigation technology for deep space missions. The error in the pulse time of arrival used in pulsar navigation is large for various practical reasons and thus greatly reduces the navigation accuracy of spacecraft near the Earth and in deep space. This paper aims to propose a novel method based on ranging information that improves the performance of XPNAV.
Design/methodology/approach
This method replaces one pulsar observation with a satellite observation. The ranging information is the difference between the absolute distance of the satellite relative to the spacecraft and the estimated distance of the satellite relative to the spacecraft. The proposed method improves the accuracy of XPNAV by combining the ranging information with the observation data of two pulsars.
Findings
The simulation results show that the proposed method greatly improves the XPNAV accuracy by 70% compared with the conventional navigation method that combines the observations of three pulsars. This research also shows that a larger angle between the orbital plane of the satellite and that of the spacecraft provides higher navigation accuracy. In addition, a greater orbital altitude difference implies higher navigation accuracy. The position error and ranging error of the satellite have approximately linear relationships with the navigation accuracy.
Originality/value
The novelty of this study is that the satellite ranging information is integrated into the pulsar navigation by using mathematical geometry.