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The first touchdown moment of aircraft tyres on a runway is the critical phase where maximum of the vertical and horizontal ground loads is produced. Some valuable drop tests have been performed at Langley research centre to simulate the touchdown and the spin-up dynamics. However, a long impact basin and a huge power source to accelerate and decelerate the landing gear mechanism have been used. Based on a centrifugal mechanism, the purpose of this paper is to propose the conceptual design of a new experimental setup to simulate the spin-up dynamics.

A schematic view of the proposed mechanism is presented, and its components are introduced. Operating condition of the system and the test procedure are discussed in detail. Finally, tyre spin-up dynamics of Boeing 747 is considered as a case study, and operating condition of the system and the related test parameters are extracted.

It is shown that the aircraft tyre spin-up dynamics can be simulated in a limited laboratory space with low energy consumption. The proposed setup enables the approach velocity, sink rate and vertical ground load to be adjusted by low power actuators. Hence, the proposed mechanism can be used to simulate the tyre spin-up dynamics of different types of aircraft.

It is important to note that more details of the setup, including the braking and actuating mechanisms together with their control procedures, should be clarified in practice. In addition, the curved path introduced as the runway will cause errors in the results. Hence, a compromise should be made between the tyre pressure, path curvature, the induced error and the cost of the experimental setup.

The proposed experimental setup could be constructed in a limited space and at a relatively low cost. Low power actuators are used in the proposed system. Hence, in addition to the performance tests, fatigue tests of the landing gear mechanism will also be possible.

Based on a centrifugal mechanism, the conceptual design of a new experimental setup is presented for simulating the tyre spin-up dynamics of aircraft. Considering that the drag load developed during tyre spin-up following initial touchdown is an important factor governing the design of the landing gear mechanism and aircraft structure, the authors hope this paper encourages engineers to continuously make efforts to increase the transparency of the touchdown process, enabling optimisation of landing gear design.

Due to the static condition of the wheels at touchdown, they skid on the runway, which may cause the tyres to burn and wear. This phenomenon occurs in a fraction of a second, known as the spin-up period. The purpose of this paper is to introduce a new strategy to reduce the horizontal force, tyre temperature and wear during the spin-up period.

First, the dynamics of two different phases of landing, namely, spin-up and breaking phases, are reviewed. Second, a strategy to prevent excessive temperature and wear of the tyre is presented.

It is found that using a lubricant and coolant, such as water, at the spin-up stretch of the runway is a simple and practical solution to prevent excessive temperature and wear of the tyre. It is revealed that, despite increasing the spin-up period, the rise of the tyre temperature is eliminated and the material properties are preserved for effective braking. A rough quantitative analysis demonstrates that the wetting of tyres in the spin-up phase decreases the loads and tyre wear effectively.

Wetting the touchdown region of the runway without significant areas of standing water is the most practical strategy with the technology available today.

A new strategy is presented for landing with reduced tyre wear. It is the hope that this paper can inspire continuous efforts to realize the implementation of the strategy.

This paper aims to present a black-box fuzzy system identification method coupled with genetic algorithm optimization approach to predict the mixture thermal conductivity at dissimilar temperatures and nanoparticle concentrations, in the examined domains.

WO3 nanoparticles are dispersed in the deionized water to produce a homogeneous mixture at various nanoparticles mass fractions of 0.1, 0.5, 1.0 and 5.0 Wt.%.

The results depicted that the models not only have satisfactory precision, but also have acceptable accuracy in dealing with non-trained input values.

The transmission electron microscopy is applied to measure the mean diameters, shape and morphology of the dry nanoparticles. Moreover, the stability of nanoparticles inside the water is evaluated by using zeta potential and dynamic light scattering (DLS) tests. Then, the prepared nanofluid thermal conductivity is presented at different values of temperatures and concentrations.

Education is a human right and access to high quality education is key to sustainable socioeconomic development. Improving the quality of higher education institutes is essential for generating the productive human resources. Assessing the quality of higher education from the students’ perspective can be considered a crucial factor in the monitoring of service quality in universities. The purpose of this paper is to evaluate the quality of educational services in a higher education institute, the Kermanshah University of Medical Sciences (KUMS), in the west of Iran.

A multistage sampling method was used to select 346 students from the KUMS, who were enrolled in the second semester of the academic year 2015-2016. The SERVQUAL questionnaire was used to gather data on students’ perceptions and their expectations about the quality of educational services. The authors used a statistical significance level of 0.05 to examine the gap between the students’ expectations and their perceptions of service quality in five dimensions, namely tangibles, responsiveness, reliability, empathy and assurance.

The results showed that there was a negative service quality gap in all five dimensions. The overall mean score of students’ expectations and their perceptions was 3.19±0.44 and 2.4±0.45, respectively. The score gap between the overall mean score of perceptions and expectations of students was −0.79, which was statistically significant (p<0.0001). The highest and lowest quality gaps were related to the assurance (−0.84) and tangible (−0.70) dimensions, respectively.

The study indicated that the quality of educational services provided in the KUMS did not meet students’ expectations in five dimensions of service quality. Thus, it warrants further investigations to determine how to improve the quality of educational services in higher education institutes such as the KUMS.

This paper aims to examine tourists' behavioral changes in response to health crises, this study examines the individual's uncertainty and adaptability to the challenges using behavioral coping strategies.

The study combines the theory of planned behavior (TPB) and protection motivation theory. Using the PLS-SEM technique, this study examines the relationship between the destination's competitive profits and travel intention of Iranian tourists in the post-Covid-19 pandemic.

The social-support coping (Instrumental) does not incorporate tourists' adaptive behaviors. Vulnerable vaccination significantly affects the extremeness of an individual's problem-focused coping, which affects tourist's adaptive behaviors in crisis time, indicating the effectiveness of the Covid-19 vaccination on travel intention.

The findings may assist tourism authorities and planners develop unique tourism products and services based on tourist behavior following the health crises.

This study contributes to development of the TPB method, indicating that visa exemption and competitive profits of a destination would motivate travel intention existing inefficacy of local government and its negative background, reshaping and thus influencing changing behavior.