The intermittent flow cold storage heat exchanger is one of the most important components of the pulse tube expansion refrigerator based on the reverse Brayton cycle. In the experimental system, the volume and heat transfer of the helical tube play a decisive role in the stable operation of the whole experimental system. However, there are few studies on heat transfer in a helical tube under helium working medium and intermittent flow conditions. In this paper, a process and method for calculating the volume of a helical tube are proposed based on the gas vessel dynamics model. Subsequently, a three-dimensional simulation model of the helical tube was established to analyze the heat transfer process of cryogenic helium within the tube. The simulations revealed that the temperature of helium in the tube decreases to the wall temperature and does not change when the helical angle exceeds 720°. Moreover, within the mass flow rate range of 1.6 g/s to 3.2 g/s, an increase in the mass flow rate was found to enhance the heat transfer performance of the helical tube. This study provides a reference for the selection and application of a helical tube under intermittent flow conditions and also contributes to the experimental research of inter-wall heat exchanger and pulse tube expansion refrigerators.

Climate change has adverse effects on ecosystems and several socio-economic sectors including health. Indeed, infrastructure, continuity of medical services, and the hospital environment are all directly affected by the effects of climate-related risks. This study aims to describe the observations of the effects of climate change risks on health systems in the Greater Lomé health region of Togo. We used an interview guide and a questionnaire to collect information. The observations allowed us to assess the effects caused by climate risks. According to the results, 84.62% of respondents attest that health centers experience flooding during rainy periods and damage caused by strong winds is noticeable among 76.92% of respondents. More than 25.40% and 61.86% respectively of respondents mention that droughts and floods have effects on health systems. The results of this study will allow health system managers to become aware of how to plan useful actions to facilitate the management of climate-related risks in health facilities in the Greater Lomé health region. In view of all these results, it is necessary that measures be taken to strengthen the resilience of health systems through awareness campaigns and training of actors throughout the health pyramid.

The study aims to investigate and analyse the social media, precisely the Instagram activity of several hotels in the city of Yogyakarta, Indonesia. Having been the second most popular destination besides Bali, it is mainly dominated by domestic tourism. Although several governmental institutions exist, the study focuses on the hotel’s activity only. The main purpose was to find, that after the classification of the posts, whether there is a more positive effect of one as opposed to the other type of posts. In addition, it was also important to see if with the time advancing positive effect of likes and comments appear and the relation of hashtags, likes and comments. Data was collected between 1st of January 2023. and 15th of July 2024. The first step was to collect posts done by the suppliers and then the posts were classified. Also, the number of hashtags used were collected. Second step was to collect the response from the demand side by gathering their likes and comments. Data then was analysed with SPSS 24 and JASP program. Results show that while there is no significance on increasing likes and comments with the months advancing, but in terms of the type of the posts there is. Promotional posts with other suppliers tend to bring a lot more comments and likes than self-promotional posts. This study’s main purpose to analyse through social media posts to enhance online networking by local suppliers promoting each other’s products.