The global focus on water desalination using solar energy is particularly pronounced today. Previous studies have affirmed the efficiency of the Forward Osmosis (FO) and Membrane Distillation (MD) ...hybrid desalination system. The Photovoltaic Thermal (PVT) solar system, which generates both thermal and electrical energy, is complemented using Phase Change Material (PCM). PCM, known for storing and releasing significant heat during phase change, is used in the evening to meet the thermal needs of the system. Additionally, an integrated battery system stores the electrical energy generated by PVT, ensuring the system's electricity requirements are sustained during the night. A comprehensive numerical model, PVT-PCM-FO-MD, has been developed to analyze the proposed system. Operating seamlessly under natural conditions for a typical day on March, June and September, the proposed system can produce freshwater continuously over a 24-hour period. To assess system performance, three PCM thicknesses (2 cm, 4 cm, and 6 cm) were employed. Designed for small-scale applications, this system is well-suited for brackish water desalination in remote areas. Notably, the highest water production recorded was 213.25 L during a 24-hour operation and the MD unit exhibited an impressive 83.78 % evaporation efficiency during the typical day on June, with nighttime efficiency reaching 37.07 %, specifically at 3 am, utilizing a 2 cm PCM thickness in the solar energy system and it was 37.22 % at the same hour and PCM thickness in September. This study further explores the impact of initial brackish water salinity on water production after 24 h and investigates the influence of the initial draw solution concentration in the draw tank on desalinated water production. The study found that despite varying initial salinity levels, the difference in water produced at the end of the day was not exceeding 1.6 L.
This paper offers a comprehensive overview of advanced water desalination systems powered by renewable energy sources, specifically focusing on developments in the past decade. Solar energy is ...particularly emphasized as a pivotal resource for powering diverse desalination methods, including membrane distillation, reverse osmosis, humidification-dehumidification, forward osmosis, and hybrid systems. The primary objectives of this study encompass evaluating current advancements in renewable energy systems, especially solar energy, for driving water desalination processes. Furthermore, the study aims to identify gaps in research, challenges, and recommendations within these processes, and to assess the performance and refinement potential of hybrid desalination systems. Through a comprehensive analysis of various investigations, integrated effectiveness and cost-efficiency are examined, focusing on practical energy utilization. Notably, the analysis reveals the potential of hybrid desalination systems to reduce energy consumption. For instance, the hybridization of forward osmosis with membrane distillation showcases a significant energy ratio decrease from 0.89 to 0.64. Moreover, the combination of humidification-dehumidification with reverse osmosis is shown to reduce energy usage while enhancing freshwater output by up to 38% compared to standalone reverse osmosis. However, challenges persist, such as the need for improved integration of hybrid systems with concentrated solar collectors like photovoltaic thermal and concentrated photovoltaic thermal technologies.
•A comprehensive review of water desalination systems powered by renewable energy.•The importance of combination of solar energy with hybrid desalination systems.•Renewable energy integration with different desalination techniques.•A comparative analysis of integration of renewable energy with hybrid desalination.•Challenges and future recommendations for successful integration of renewable energy with desalination.
This study aimed to estimate the prevalence of rapid eye movement-related obstructive sleep apnea (REMrOSA) using common definitions.
This was a retrospective cohort study that used three sets of ...criteria to identify patients with REMrOSA. These criteria were defined as strict, intermediate, and lenient depending on the apnea-hypopnea index (AHI), AHI during REM sleep/(AHI during non-REM sleep NREM-AHI), NREM-AHI and REM duration.
The study included 609 patients with OSA and full sleep study. The prevalence of REMrOSA was 26%, 33%, and 52% using the strict, intermediate, and lenient criteria, respectively. There were no differences in the patients' general and demographic characteristics between the different groups of the three definitions. REMrOSA patients were more likely to be younger females than non-REMrOSA (NREMrOSA) patients. Comorbidities were more frequent in the REMrOSA group compared to NREMrOSA when using strict and intermediate definitions. In contrast, AHI, mean O2 saturation, and time spent <90% O2 saturation were significantly worse during NREMrOSA compared to REMrOSA, regardless of the criteria used. Our study reported higher AHI, lower mean oxygen saturation, lower minimum oxygen saturation, and longer time of desaturation during REMrOSA when lenient definition was used compared to when strict and intermediate definitions were used.
REMrOSA is a common condition with a prevalence ranging between 26% and 52% depending on what definition is applied. Although OSA tends to be more severe with lenient definition, however, the clinical and polysomnographic features were similar among REMrOSA groups regardless of the definition used.
The Saudi Privacy Policy Dataset Al-Khalifa, Hend; Mashaabi, Malak; Al-Yahya, Ghadi ...
arXiv (Cornell University),
04/2023
Paper, Journal Article
Odprti dostop
This paper introduces the Saudi Privacy Policy Dataset, a diverse compilation of Arabic privacy policies from various sectors in Saudi Arabia, annotated according to the 10 principles of the Personal ...Data Protection Law (PDPL); the PDPL was established to be compatible with General Data Protection Regulation (GDPR); one of the most comprehensive data regulations worldwide. Data were collected from multiple sources, including the Saudi Central Bank, the Saudi Arabia National United Platform, the Council of Health Insurance, and general websites using Google and Wikipedia. The final dataset includes 1,000 websites belonging to 7 sectors, 4,638 lines of text, 775,370 tokens, and a corpus size of 8,353 KB. The annotated dataset offers significant reuse potential for assessing privacy policy compliance, benchmarking privacy practices across industries, and developing automated tools for monitoring adherence to data protection regulations. By providing a comprehensive and annotated dataset of privacy policies, this paper aims to facilitate further research and development in the areas of privacy policy analysis, natural language processing, and machine learning applications related to privacy and data protection, while also serving as an essential resource for researchers, policymakers, and industry professionals interested in understanding and promoting compliance with privacy regulations in Saudi Arabia.
