Liantao Hou, Yinsheng Yang, Xiaoyi Zhang and Chunming Jiang
The relationship between farm size and greenhouse gas (GHG) emissions has not been clearly defined. This paper aims to assess and compare the impact of farm size on greenhouse gas…
Abstract
Purpose
The relationship between farm size and greenhouse gas (GHG) emissions has not been clearly defined. This paper aims to assess and compare the impact of farm size on greenhouse gas (GHG) emissions derived from wheat and maize production in the North China Plain (NCP), one of the most important agricultural regions in China.
Design/methodology/approach
A field survey through face-to-face interviews was conducted to collect the primary data, and life cycle assessment method, a worldwide comparable framework, was then adopted to characterize the farm-size effect on greenhouse gas (GHG) wheat and maize production in NCP.
Findings
It was confirmed that GHG emissions from N fertilizer production and use were the primary contributor to total carbon footprint (CF). As farm size increased, maize yield increased but wheat yield barely changed, while area-scaled and yield-scaled CF declined for both crops. These results were supposed to relate to utilize the inputs more efficiently resulting from increased application of modern agriculture methods on larger operations. It was also found maize not only had higher grain yields, but possessed much smaller CFs. More notably, the reduction of CF with farm size seemed to be more sensitive for maize as compared to wheat. To further mitigate GHG emissions, farm size should better be larger for wheat than for maize.
Originality/value
This study provides useful information guide for Chinese agriculture in increasing crop production, raising farm income and relieving environmental burdens caused by the misuse of agricultural resources.
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Naveed Ahmad, Amran Harun, Hafiz Muhammad Usman Khizar, Junaid Khalid and Shumaila Khan
The purpose of this study is to examine the drivers and barriers of travel behavior associated with tourist behavior during/post-COVID-19 pandemic to provide a knowledge base as…
Abstract
Purpose
The purpose of this study is to examine the drivers and barriers of travel behavior associated with tourist behavior during/post-COVID-19 pandemic to provide a knowledge base as well as an agenda for future research.
Design/methodology/approach
The authors utilized the Systematic Literature Review (SLR) technique for searching the articles published in Web of Science (WOS) and Scopus, to identify the main drivers and barriers affecting the tourist behavior during/post-COVID-19 pandemic. Eventually, 47 articles were chosen for the final analysis.
Findings
The findings are reported in three sections, (1) quantitative research profile, (2) qualitative synthesis and (3) future agenda. This study addresses the nuanced questions regarding the significant change in tourist travel behavior, emotional dynamics and a detailed understanding of mechanisms, such as which drivers and barriers affect tourist behavior in a particular destination. Drivers and barriers to tourist travel behavior were characterized in personal-related, destination-related, and health-related factors. Moreover, this study provides thought-provoking ideas in theory, policy and practice in the field of tourism and hospitality.
Research limitations/implications
This study has three limitations, as follows. First, the authors searched only two databases, Scopus and Web of Science, due to which the authors might be missing some related studies existing on the other databases. Although these databases provide an extensive range of academic literature, further studies could extend the data collection from the other databases (e.g. via Taylor & Francis). However, our systematic literature review (SLR) coverage is quite extensive, since journals are listed on these three main databases. Second, the authors followed a main study search protocol based on the synonyms and related keywords, however, some of the studies that may be related to the tourist behavior towards the destination are missing on account of the lack of our keywords in there, title, author, keyword and abstract. Furthermore, future research could endeavor to add other keywords to expand the results of studies. Third, although the accurate analysis was conducted to reduce subjectivity in identifying themes for drivers and barriers of tourist behavior, future studies on categorization could work to ensure that other sub-themes categorize.
Practical implications
The recent study has some key practical implications. First, this study is valuable for all the stakeholders in a unique way, including destination managers, academicians and policymakers, because it provides insight into barriers and drivers that influence the development of tourist behavior towards the destination. Second, the current study also offers practical implications for people involved in tourism service industries including governments and private businesses. Policymakers and other leaders are increasingly interested in harnessing the economic potential of tourism. Therefore, identifying the barrier which is inhibiting the tourist traffic towards the destination is beneficial to understand and effectively develop strategies to minimize the effect of such factors. Moreover, drivers and barriers of tourist behavior towards the destination in the COVID-19 pandemic situation towards the destination may help to create a framework for the development of destinations according to the current vulnerable situation. Third, current findings suggest that tourism marketers understand the drivers and barrier constructs found in this study and tailor their marketing strategies for attracting existing and new tourists. For instance, marketers should understand the drivers and barriers of tourist behavior for effective strategy development to increase the positive effect of drivers and to reduce the negative effect of barriers.
Originality/value
This is the first systematic literature review on the impact of drivers and barriers of tourist travel behavior. This paper analyses the methods and approaches that have been used in the previous literature to examine the drivers and barriers of tourist travel behavior. The paper ends with the research implication and limitations of the studies.
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Fong Yew Leong, Dax Enshan Koh, Wei-Bin Ewe and Jian Feng Kong
This study aims to assess the use of variational quantum imaginary time evolution for solving partial differential equations using real-amplitude ansätze with full circular…
Abstract
Purpose
This study aims to assess the use of variational quantum imaginary time evolution for solving partial differential equations using real-amplitude ansätze with full circular entangling layers. A graphical mapping technique for encoding impulse functions is also proposed.
Design/methodology/approach
The Smoluchowski equation, including the Derjaguin–Landau–Verwey–Overbeek potential energy, is solved to simulate colloidal deposition on a planar wall. The performance of different types of entangling layers and over-parameterization is evaluated.
Findings
Colloidal transport can be modelled adequately with variational quantum simulations. Full circular entangling layers with real-amplitude ansätze lead to higher-fidelity solutions. In most cases, the proposed graphical mapping technique requires only a single bit-flip with a parametric gate. Over-parameterization is necessary to satisfy certain physical boundary conditions, and higher-order time-stepping reduces norm errors.
Practical implications
Variational quantum simulation can solve partial differential equations using near-term quantum devices. The proposed graphical mapping technique could potentially aid quantum simulations for certain applications.
Originality/value
This study shows a concrete application of variational quantum simulation methods in solving practically relevant partial differential equations. It also provides insight into the performance of different types of entangling layers and over-parameterization. The proposed graphical mapping technique could be valuable for quantum simulation implementations. The findings contribute to the growing body of research on using variational quantum simulations for solving partial differential equations.
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Vania Vigolo, Giorgio Mion and Patrícia Moura e Sá
Responsible management of water resources is critical owing to its effects on the environment and society. This study aims to address customer perceptions of a water utility…
Abstract
Purpose
Responsible management of water resources is critical owing to its effects on the environment and society. This study aims to address customer perceptions of a water utility during a severe environmental crisis that affected northern Italy and aims to deepen the understanding of the relationship between corporate social responsibility (CSR), perceived crisis response and corporate reputation.
Design/methodology/approach
This study draws on legitimacy theory and attribution theory, adopting a quantitative design. In detail, a moderated mediation model is used to investigate the direct effect of CSR on reputation, the mediating effect of perceived crisis response on the relationship between CSR and reputation and the moderating effect of blame attribution on the relationship between CSR and perceived crisis response. In addition, the evolution of the crisis event and its management is traced through the analysis of the water utilities’ sustainability reports published since the beginning of the crisis.
Findings
The findings show that CSR affects corporate reputation directly and via perceived crisis response. In addition, CSR improves perceived crisis response, especially when an organization is held responsible for a crisis. The analysis of the CSR report allows for understanding the evolution of CSR policies of water utilities, shifting attention from a merely informative role of sustainability disclosure to a more comprehensive approach to perfluoroalkyl substances risks in the struggle of contributing to sustainable development. Theoretical and managerial implications are also discussed.
Practical implications
The findings suggest some managerial implications about the usefulness of adopting CSR for crisis management and, furthermore, the importance of communicating CSR policies to all stakeholders overall – the customers of public utilities.
Originality/value
This paper focuses on the relationship between CSR, reputation and blame attribution. Literature on this topic is still scarce overall in the field of public utilities. Furthermore, this study is relevant because it faces one of the major European environmental crises that affected the water sector and provides helpful insights for all public utility sectors and, more generally, for environmental crisis management.
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Jie Zhang, Yuwei Wu, Jianyong Gao, Guangjun Gao and Zhigang Yang
This study aims to explore the formation mechanism of aerodynamic noise of a high-speed maglev train and understand the characteristics of dipole and quadrupole sound sources of…
Abstract
Purpose
This study aims to explore the formation mechanism of aerodynamic noise of a high-speed maglev train and understand the characteristics of dipole and quadrupole sound sources of the maglev train at different speed levels.
Design/methodology/approach
Based on large eddy simulation (LES) method and Kirchhoff–Ffowcs Williams and Hawkings (K-FWH) equations, the characteristics of dipole and quadrupole sound sources of maglev trains at different speed levels were simulated and analyzed by constructing reasonable penetrable integral surface.
Findings
The spatial disturbance resulting from the separation of the boundary layer in the streamlined area of the tail car is the source of aerodynamic sound of the maglev train. The dipole sources of the train are mainly distributed around the radio terminals of the head and tail cars of the maglev train, the bottom of the arms of the streamlined parts of the head and tail cars and the nose tip area of the streamlined part of the tail car, and the quadrupole sources are mainly distributed in the wake area. When the train runs at three speed levels of 400, 500 and 600 km·h−1, respectively, the radiated energy of quadrupole source is 62.4%, 63.3% and 71.7%, respectively, which exceeds that of dipole sources.
Originality/value
This study can help understand the aerodynamic noise characteristics generated by the high-speed maglev train and provide a reference for the optimization design of its aerodynamic shape.
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Yang Li, Zhicheng Zheng, Yaochen Qin, Haifeng Tian, Zhixiang Xie and Peijun Rong
Drought is the primary disaster that negatively impacts agricultural and animal husbandry production. It can lead to crop reduction and even pose a threat to human survival in…
Abstract
Purpose
Drought is the primary disaster that negatively impacts agricultural and animal husbandry production. It can lead to crop reduction and even pose a threat to human survival in environmentally sensitive areas of China (ESAC). However, the phases and periodicity of drought changes in the ESAC remain largely unknown. Thus, this paper aims to identify the periodic characteristics of meteorological drought changes.
Design/methodology/approach
The potential evapotranspiration was calculated using the Penman–Monteith formula recommended by the Food and Agriculture Organization of the United Nations, whereas the standardized precipitation evaporation index (SPEI) of drought was simulated by coupling precipitation data. Subsequently, the Bernaola-Galvan segmentation algorithm was proposed to divide the periods of drought change and the newly developed extreme-point symmetric mode decomposition to analyze the periodic drought patterns.
Findings
The findings reveal a significant increase in SPEI in the ESAC, with the rate of decline in drought events higher in the ESAC than in China, indicating a more pronounced wetting trend in the study area. Spatially, the northeast region showed an evident drying trend, whereas the southwest region showed a wetting trend. Two abrupt changes in the drought pattern were observed during the study period, namely, in 1965 and 1983. The spatial instability of moderate or severe drought frequency and intensity on a seasonal scale was more consistent during 1966–1983 and 1984–2018, compared to 1961–1965. Drought variation was predominantly influenced by interannual oscillations, with the periods of the components of intrinsic mode functions 1 (IMF1) and 2 (IMF2) being 3.1 and 7.3 years, respectively. Their cumulative variance contribution rate reached 70.22%.
Research limitations/implications
The trend decomposition and periods of droughts in the study area were analyzed, which may provide an important scientific reference for water resource management and agricultural production activities in the ESAC. However, several problems remain unaddressed. First, the SPEI considers only precipitation and evapotranspiration, making it extremely sensitive to temperature increases. It also ignores the nonstationary nature of the hydrometeorological water process; therefore, it is prone to bias in drought detection and may overestimate the intensity and duration of droughts. Therefore, further studies on the application and comparison of various drought indices should be conducted to develop a more effective meteorological drought index. Second, the local water budget is mainly affected by surface evapotranspiration and precipitation. Evapotranspiration is calculated by various methods that provide different results. Therefore, future studies need to explore both the advantages and disadvantages of various evapotranspiration calculation methods (e.g. Hargreaves, Thornthwaite and Penman–Monteith) and their application scenarios. Third, this study focused on the temporal and spatial evolution and periodic characteristics of droughts, without considering the driving mechanisms behind them and their impact on the ecosystem. In future, it will be necessary to focus on a sensitivity analysis of drought indices with regard to climate change. Finally, although this study calculated the SPEI using meteorological data provided by China’s high-density observatory network, deviations and uncertainties were inevitable in the point-to-grid spatialization process. This shortcoming may be avoided by using satellite remote sensing data with high spatiotemporal resolution in the future, which can allow pixel-scale monitoring and simulation of meteorological drought evolution.
Practical implications
Under the background of continuous global warming, the climate in arid and semiarid areas of China has shown a trend of warming and wetting. It means that the plant environment in this region is getting better. In the future, the project of afforestation and returning farmland to forest and grassland in this region can increase the planting proportion of water-loving tree species to obtain better ecological benefits. Meanwhile, this study found that in the relatively water-scarce regions of China, drought duration was dominated by interannual oscillations (3.1a and 7.3a). This suggests that governments and nongovernmental organizations in the region should pay attention to the short drought period in the ESAC when they carry out ecological restoration and protection projects such as the construction of forest reserves and high-quality farmland.
Originality/value
The findings enhance the understanding of the phasic and periodic characteristics of drought changes in the ESAC. Future studies on the stress effects of drought on crop yield may consider these effects to better reflect the agricultural response to meteorological drought and thus effectively improve the tolerance of agricultural activities to drought events.
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Ying Li, Li Zhao, Kun Gao, Yisheng An and Jelena Andric
The purpose of this paper is to characterize distracted driving by quantifying the response time and response intensity to an emergency stop using the driver’s physiological…
Abstract
Purpose
The purpose of this paper is to characterize distracted driving by quantifying the response time and response intensity to an emergency stop using the driver’s physiological states.
Design/methodology/approach
Field tests with 17 participants were conducted in the connected and automated vehicle test field. All participants were required to prioritize their primary driving tasks while a secondary nondriving task was asked to be executed. Demographic data, vehicle trajectory data and various physiological data were recorded through a biosignalsplux signal data acquisition toolkit, such as electrocardiograph for heart rate, electromyography for muscle strength, electrodermal activity for skin conductance and force-sensing resistor for braking pressure.
Findings
This study quantified the psychophysiological responses of the driver who returns to the primary driving task from the secondary nondriving task when an emergency occurs. The results provided a prototype analysis of the time required for making a decision in the context of advanced driver assistance systems or for rebuilding the situational awareness in future automated vehicles when a driver’s take-over maneuver is needed.
Originality/value
The hypothesis is that the secondary task will result in a higher mental workload and a prolonged reaction time. Therefore, the driver states in distracted driving are significantly different than in regular driving, the physiological signal improves measuring the brake response time and distraction levels and brake intensity can be expressed as functions of driver demographics. To the best of the authors’ knowledge, this is the first study using psychophysiological measures to quantify a driver’s response to an emergency stop during distracted driving.
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Xuejun Zhao, Yong Qin, Hailing Fu, Limin Jia and Xinning Zhang
Fault diagnosis methods based on blind source separation (BSS) for rolling element bearings are necessary tools to prevent any unexpected accidents. In the field application, the…
Abstract
Purpose
Fault diagnosis methods based on blind source separation (BSS) for rolling element bearings are necessary tools to prevent any unexpected accidents. In the field application, the actual signal acquisition is usually hindered by certain restrictions, such as the limited number of signal channels. The purpose of this study is to fulfill the weakness of the existed BSS method.
Design/methodology/approach
To deal with this problem, this paper proposes a blind source extraction (BSE) method for bearing fault diagnosis based on empirical mode decomposition (EMD) and temporal correlation. First, a single-channel undetermined BSS problem is transformed into a determined BSS problem using the EMD algorithm. Then, the desired fault signal is extracted from selected intrinsic mode functions with a multi-shift correlation method.
Findings
Experimental results prove the extracted fault signal can be easily identified through the envelope spectrum. The application of the proposed method is validated using simulated signals and rolling element bearing signals of the train axle.
Originality/value
This paper proposes an underdetermined BSE method based on the EMD and the temporal correlation method for rolling element bearings. A simulated signal and two bearing fault signal from the train rolling element bearings show that the proposed method can well extract the bearing fault signal. Note that the proposed method can extract the periodic fault signal for bearing fault diagnosis. Thus, it should be helpful in the diagnosis of other rotating machinery, such as gears or blades.
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Yang Li, Zhixiang Xie, Yaochen Qin and Zhicheng Zheng
This paper aims to study the temporal and spatial variation of vegetation and the influence of climate change on vegetation coverage in the Yellow River basin, China. The current…
Abstract
Purpose
This paper aims to study the temporal and spatial variation of vegetation and the influence of climate change on vegetation coverage in the Yellow River basin, China. The current study aimed to evaluate the role of a series of government-led environmental control projects in restoring the ecological environment of the Yellow River basin.
Design/methodology/approach
This paper uses unary linear regression, Mann–Kendall and wavelet analyses to study the spatial–temporal variations of vegetation and the response to climate changes in the Yellow River, China.
Findings
The results showed that for the past 17 years, not only the mean annual increase rate of the Normalized Difference Vegetation Index (NDVI) was 0.0059/a, but the spatial heterogeneity also yields significant results. The vegetation growth in the southeastern region was significantly better than that in the northwestern region. The variation period of the NDVI in the study area significantly shortened, and the most obvious oscillation period was half a year, with two peaks in one year. In addition, there are positive and negative effects of human activities on the change of vegetation cover of the Loess Plateau. The project of transforming cultivated land to forest and grassland promotes the increase of vegetation cover of the Loess plateau. Unfortunately, the regional urbanization and industrialization proliferated, and the overloading of grazing, deforestation, over-reclamation, and the exploitation and development of the energy area in the grassland region led to the reduction of the NDVI. Fortunately, the positive effects outweigh the negative ones.
Originality/value
This paper provides a comprehensive insight to analysis of the vegetation change and the responses of vegetation to climate change, with special reference to make the planning policy of ecological restoration. This paper argues that ecological restoration should be strengthened in areas with annual precipitation less than 450 mm.
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Ming Gao, Dongkai Li, Kun Liu, Shuliang Xu, Feng Zhao, Ben Guo, Anhui Pan, Xiao Xie and Huanre Han
The brake pipe system was an essential braking component of the railway freight trains, but the existing E-type sealing rings had problems such as insufficient low-temperature…
Abstract
Purpose
The brake pipe system was an essential braking component of the railway freight trains, but the existing E-type sealing rings had problems such as insufficient low-temperature resistance, poor heat stability and short service life. To address these issues, low-phenyl silicone rubber was prepared and tested, and the finite element analysis and experimental studies on the sealing performance of its sealing rings were carried out.
Design/methodology/approach
The low-temperature resistance and thermal stability of the prepared low-phenyl silicone rubber were studied using low-temperature tensile testing, differential scanning calorimetry, dynamic thermomechanical analysis and thermogravimetric analysis. The sealing performance of the low-phenyl silicone rubber sealing ring was studied by using finite element analysis software abaqus and experiments.
Findings
The prepared low-phenyl silicone rubber sealing ring possessed excellent low-temperature resistance and thermal stability. According to the finite element analysis results, the finish of the flange sealing surface and groove outer edge should be ensured, and extrusion damage should be avoided. The sealing rings were more susceptible to damage in high compression ratio and/or low-temperature environments. When the sealing effect was ensured, a small compression ratio should be selected, and rubbers with hardness and elasticity less affected by temperature should be selected. The prepared low-phenyl silicone rubber sealing ring had zero leakage at both room temperature (RT) and −50 °C.
Originality/value
The innovation of this study is that it provides valuable data and experience for the future development of the sealing rings used in the brake pipe flange joints of the railway freight cars in China.