Water Pool Research Articles

Water and Energy Sustainability of Swimming Pools: A Case Model on the Costa Brava, Catalonia

The aim of this research is to propose a more sustainable swimming pool, in terms of water and energy, in the Costa Brava area. The methodology is focused on the creation of a descriptive water and energy model for swimming pools and their monitoring, to propose the transition to a more sustainable swimming pool, in the context of climate change. The research is characterized by an exploratory, descriptive, and simulation approach to adapt swimming pools to the new requirements. Two significant impacts are highlighted from the perspective of water and energy stress—the carbon footprint, related to environmental impact and climate change, and the new business models of the sector, for a more sustainable tourism, with more sustainable pools. In terms of water balance, evaporation is an important variable and there are technical solutions on the market to control it, such as the use of covers. Furthermore, the modeling and simulation carried out helps to calculate the variable as a tool for improvement. For energy balance, in outdoor pools, pumping is an important variable and there are technologies, such as speed variation, that make it possible to reduce this. Furthermore, it should be noted that this research represents an important tool for the improvement of sustainability and operability for the various stakeholders, especially owners and governments, to face climate change, which is becoming increasingly critical for many regions.

Isotopic evidence for seasonal water sources in tree xylem and forest soils

AbstractForest trees greatly influence both the routing of water downward into the subsurface and the re‐routing of water upward through water uptake and transpiration. To reveal how the subsurface soil water pools used by trees change across seasons, we analysed 2 years of stable isotope ratios of precipitation, soil water from different depths (using both bulk sampling and suction‐cup lysimeters), and xylem in a mixed beech and spruce forest. Precipitation as well as mobile and bulk soil waters all showed a distinct seasonal signature; the seasonal amplitude decreased with depth, and mobile soil waters fluctuated less than bulk soil waters. Xylem water signatures in both tree species were similar to the bulk soil water signatures and rather different from the mobile soil water signatures. The beech and spruce trees had different isotope ratios, suggesting the use of different water sources, and these differences were larger under dry antecedent conditions than wet antecedent conditions. Despite these differences, both species predominantly transpired waters with a winter‐precipitation isotopic signature throughout the summer, including during wet conditions when more recent precipitation was available. Over most of the sampling dates, the fraction of recent precipitation (i.e. from the preceding 30 days) in xylem water was low, despite both species typically demonstrating the use of both shallow and deeper soil waters. These results provide evidence that the soil water storages used by these trees are largely filled in winter and bypassed by recent precipitation, implying long residence times.

Control of overgrowth of Potamogeton crispus in shallow lakes by light shading and artificial introductions

Potamogeton crispus is a common submersed aquatic plant in shallow lakes in China, and its overgrowth and rapid decomposing have become an important environmental problem affecting the water quality of lakes every summer. Introducing other submersed plants to substitute Potamogeton crispus can improve the structure of the aquatic plant community and to reduce the growth of Potamogeton crispus to some degree, but the effect is poor and short-lived. Considering the fact that Potamogeton crispus is sensitive to changes in light intensity, the two methods of shading the water surface and introduction of other submerged plants were used synergistically. In a large simulated experimental pool, light intensity was reduced by placing black polyethylene floating spheres on the water surface and planting three species of submerged plants, namely, Vallisneria natans, Hydrilla verticillata and Potamogeton wrightii. Changes in the physico-chemical properties of the experimental pool water and the physiological and biochemical characteristics (morphology, chlorophyll, biomass, antioxidant enzymes and malondialdehyde) of the submerged plants during the period of 0–40 d were analyzed. The results showed that: (1) After the light intensity was reduced by 85%, Potamogeton crispus seedlings showed a significant decrease in biomass and chlorophyll content and died in large numbers within 20–30 days. (2) Catalase is the main tool for Potamogeton crispus to cope with low light stress. The activities of various antioxidant enzymes and the malondialdehyde content of Potamogeton crispus showed a decreasing trend under shade conditions, but the catalase activity increased dramatically. (3) Vallisneria natans is more tolerant of low light conditions than the other two submersed plant species. Therefore, we tried to reduce the biomass of Potamogeton crispus by combing introduction of other submersed plants and shading treatment. (4) The water quality objectives remained stable over the period of the trial, indicating that short-term shading does not have a negative impact on the quality of the water quality.

Real-time Fishpond Water Temperature Monitoring with Internet of Things (IoT) Technology

The quality of pond water is an important factor in ensuring the health and sustainability of the organisms within it. Internet of Things (IoT) technology has enabled the development of sophisticated and effective monitoring systems to monitor water quality in real-time. One important parameter that needs to be monitored is the temperature of the pond water, as unstable temperatures can harm aquatic organisms. To obtain good quality and disease-free fish at normal times, the optimal temperature for catfish fry is around 28˚C - 30˚C. Manual monitoring or using thermometer measuring instruments is still very traditional and limited to the ability of supervisors to carry out continuous monitoring and may cause delays in detecting significant temperature changes. This research aims to analyze the monitoring system of pool water quality based on temperature by utilizing IoT technology. The proposed system uses a DS18B20 temperature sensor that is wirelessly connected to the IoT network. The temperature data collected in real time will be uploaded to Firebase for storage and further analysis. Through the development of this IoT-based pond water quality monitoring system, it is expected to increase efficiency and reliability in monitoring pond water quality. From the monitoring conducted for approximately 24 hours, the temperature in the fishpond is 28°-30°. After analyzing with direct monitoring, the good temperature is at night at 18.00-00.00 WIB. In conjunction with a standard thermometer, resulted in an average temperature sensor error rate of less than 5%, highlighting the reliability of the IoT technology in real-time environmental monitoring.

Extremely large water droplet impact onto a deep liquid pool.

Most studies of droplet impact on liquid pools focus on droplet diameters up to the capillary length (0.27cm). We break from convention and study extremely large water droplets (1 to 6cm diameter) falling into a pool of water. We demonstrate that the depth and width of the cavity formed by large droplet impact is greatly influenced by the deformed shape of the droplet at impact (i.e., prolate, spherical, and oblate), and larger droplets amplify this behavior by flattening before impact. In particular, the maximum cavity depth is a function of the Froude number and axis ratio of the droplet just before impact. Further, the cavity depth is more dependent on the droplet height than width, and the maximum cavity diameter is independent of the droplet height. In general, we observe that more oblate droplets result in decreasing cavity depths for a fixed liquid volume. This is because an increase in horizontal droplet diameter results in a reduced impact energy flux and therefore reduced cavity depth.

High fidelity core flow measurement experiment for an advanced research reactor using a real scale mockup

Owing to spatial effects and vortex flow, flow in research reactors that use plate-type fuels can be maldistributed to the parallel channels of the core, which significantly impacts the reactor safety. In this study, the core flow of an advanced research reactor was measured in a real-scale facility under various hydraulic conditions. For flow measurement, integrated pressure lines were embedded in the mockups of 22 fuel assemblies and six fission molybdenum assemblies. Each assembly mockup was individually calibrated to obtain the relationship between the pressure drop and flow rate. Real-scale facility, which implements the characteristics of the hydraulic conditions in research reactors, was then used to evaluate the assembly-to-assembly flow distribution under normal operating condition, a partially withdrawn condition for the follower fuel assemblies, no flow for the pool water management system, and 1:1.5 asymmetric inlet flow condition. As a parallel channel system, core flow distribution was analyzed with conventional header design approach. Taking into account the measuring uncertainty, the core flow was uniformly distributed within 5 % under all conditions. This was mainly because the core flow resistance was sufficiently high and the vortex flow was minimized by the perforated plate.

Effect of uniaxial loading on the spalling of concrete panels for Melbourne's Metro Tunnel Project

AbstractThe Metro Tunnel is a Victorian Government funded infrastructure project which will create a new end‐to‐end rail line from Sunbury in the west to Cranbourne/Pakenham in the south east, with bigger and better trains, next generation signaling technology and five new underground stations. This article provides a detailed summary of the structural fire testing requirements for the platform tunnel side wall and arch lining in the Metro Tunnel's State Library and Town Hall stations. Contrasted to building fires, tunnel fires are more significant within a few minutes due to the confined space which can cause concrete spalling and jeopardize the bearing capacity of the tunnel, which is a significant concern to designers. The catastrophic European tunnel fire events in 1999 and 2001 led to the development of innovative regulations and recommendations, including guidelines endorsed by the European Federation of National (EFNARC 132F r3:2006) and Efectis R0695:2020. This paper explains the methodology taken to design the fire rated concrete test for the platform tunnel side wall and arch lining in the State Library and Town Hall stations of Melbourne's Metro Tunnel Project for structural stability for the period of a serious fire event. For the first time, uniaxial loading (500T) was applied to five large‐scale flat concrete panels (1800 × 1800 × 400 mm) which are normally unloaded during fire exposure and exposed to the RABT ZTV (rail) fire curve. The first testing program investigated the influence of polypropylene dosage in the concrete mix design and its effect on the magnitude and severity of concrete spalling. The results indicated that the recommended 2.0 kg/m3 polypropylene dosage requirement as specified by Eurocode is conservative. Concrete mix designs with a stable aggregate and the correct curing regime can mitigate spalling at significantly lower polypropylene dosage rates. The water pooling effect was evident during the fire testing and the surface cracking that developed was vertical to the surface, allowing for the release of the pore water pressure build‐up.

The Effect of Swimming Pool Water Quality on Health Complaints of Child Athletes Using the Swimming Pool (FIKK UNY)

The study aims to determine the effect of swimming pool water quality on the health complaints of children and athletes using the FIKK UNY swimming pool. The research method used was descriptive correlational research. Primary data collection techniques include observation, questionnaires, and interviews, as well as secondary data obtained from books, journals, literature, documentation, and theses related to this research. This research was conducted at the FIKK UNY swimming pool with a population of all children's swimming athletes who use the FIKK UNY swimming pool, as many as 75 children. The sample was determined by random sampling, which amounted to 50 children who were given a questionnaire several times in January 2024. The data analysis techniques used in this research are descriptive analysis and inferential analysis using the SPSS version 26.0 computer program. The results showed that: 1) The description of the water quality of the FIKK UNY swimming pool is in the high value category (meeting health requirements) (64%); 2) The description of user health complaints at the FIKK UNY swimming pool is in the high value category (no health complaints) (56%); 3) Swimming pool water quality has a positive and significant influence on health complaints of child athletes using the FIKK UNY swimming pool (significance value α = 0.00 0.05). Based on the results of the study, the authors suggest to swimming pool managers that they pay attention to the quality of their swimming pool water so that it meets the requirements of PermenKES RI Number 32 of 2017 concerning swimming pool water management, which includes physical, chemical, and microbiological parameters. Parties related to swimming pools are expected to provide counseling on the importance of swimming pool water quality for child athletes in particular and all pool users in general.

Metal–Organic Framework‐Coated Glass Vials: A Step Forward in Analytical Platforms

AbstractA robust microextraction device in the form of a glass vial internally coated with metal–organic frameworks (MOFs) is designed, fabricated by in situ growth of different Zr‐based MOFs, and fully characterized for its novel use as an analytical platform. This device, uniformly coated by the MOF, ensures high simplicity and short times when used as an analytical microextraction tool, as the device acts as both the sample container and the extraction device, being tested for monitoring the presence of a group of endocrine‐disrupting chemicals in pool waters. The thin film format and MOF nature allow for high extraction efficiency and preconcentration of these target contaminants. Adsorption and desorption of the analytes are studied through kinetic experiments, with uptakes up to 90% for propylparaben in the UiO‐66‐abdc vial, and an extremely fast desorption in just seconds. The UiO‐66‐abdc vial does not require more than 15 min to perform a complete extraction‐desorption cycle, with limits of detection down to 0.10 µg L−1 in pool waters. The MOF‐coated vials are demonstrated to be easily (and highly) reusable by simple washing for a few min followed by drying. The simplicity of the method can be pushed further working in static mode or by a simple manual shaking.

Synergistic energy solutions: Solar chimney and nuclear power plant integration for sustainable green hydrogen, electricity, and water production

Globally, countries are strategically devising and implementing plans for hydrogen production, recognizing its status as the future's primary energy fuel. This study, conducted in Irbid, Jordan, serves as a case study focusing on producing green hydrogen by integrating a Solar Chimney Power Plant (SCPP) with a nuclear power plant (NPP). The innovative design of the proposed SCPP involves the incorporation of a water pool and an electrolyzer station, facilitating the production of desalinated water, green hydrogen, and oxygen, and leveraging the excess waste heat generated by the NPP to enhance the overall system performance. The proposed integration directly routes the excess hot air from the NPP tower into the SCPP's collector to enhance the temperature profile under the collector and the air velocity, boosting electricity and water production. This integration demonstrated a significant improvement over the conventional SCPP. Specifically, the SCPP+ NPP system produced 716 MWh/year, surpassing the traditional SCPP's output of 362 MWh/year. Furthermore, the proposed design exhibited substantial gains in freshwater production, yielding approximately 260,000 tons/year compared to the conventional SCPP's 140,000 tons/year. Ratio analysis indicates a positive correlation between integrated electricity generation and water output, emphasizing the sustained improvement in water production (average ratio ∼1.88) in the SCPP+NPP system. The proposed SCPP+NPP not only doubled its green hydrogen output, reaching 25 tons/year compared to the conventional SCPP's 13 tons/year, but also contributed a substantial 200 tons/year of oxygen, surpassing the traditional SCPP's 100 tons/year. The results underscored the superior performance of the proposed SCPP+ NPP across various metrics—hydrogen production, electricity generation, freshwater yield, and oxygen output—exhibiting a twofold improvement over the conventional SCPP. Consequently, implementing the integration between SCPP and NPP, emerges as a promising and viable solution for green hydrogen production in Jordan.

The use of 18S rRNA for identification of the first record of Tadpole Shrimp Lepidurus apus (Linnaeus, 1758) from Jordan

Abstract. Abushattal S, Alnasarat H, Alnaimat SM, Eid E. 2024. The use of 18S rRNA for identification of the first record of Tadpole Shrimp Lepidurus apus (Linnaeus, 1758) from Jordan. Biodiversitas 25: 1223-1229. The tadpole shrimps are living fossils that survive in temporary water pools and are considered benthic organisms that swim and feed on tiny organisms. Two genera of tadpole shrimps exist worldwide: Triops and Lepidurus, which share similar ecological niches and habitats but never coincide. The occurrence of the tadpole shrimp Lepidurus apus in Jordan was confirmed for the first time using the 18S rRNA Gene-Based PCR Assay. The experimental approach encompassed the amplification of biological specimens utilizing a universal amplicon measuring approximately 1,500 base pairs (bp), specifically targeting the 18S ribosomal RNA (rRNA) gene. Subsequently, the acquired sequences underwent scrutiny through BlastN search against the GenBank database for validation and comparative analysis. Genetic analysis was needed to define the species accurately, especially with tadpole shrimp's generally high morphological variability. This species was recorded in a temporary freshwater pool in the desert of Al-Jafr in Ma’an governorate in southern Jordan. The DNA analysis showed a 100% identical sequence of the 18S rRNA gene with Lepidurus apus sequences. This record is important due to the ecological role of the tadpole shrimps as filter feeders, consuming algae, bacteria, and other small particles of organic matter, and as a food source for various fish, birds, and other aquatic animals. In addition, it will pave the way for future research to identify its economic importance, such as its role in mosquito control and its potential role in aquaculture. Finally, tadpole shrimp are sensitive to environmental changes and could be used to indicate climatic changes and habitat degradation. This is mainly due to their sensitivity to changes in water quality, including temperature, pH, and chemical composition, and their niche requirements for survival and reproduction. In addition, monitoring tadpole shrimp distribution and comparing it with historical records can reveal patterns of climate-induced range shifts.

Numerical investigation of water entry of hydrophobic spheres

We perform numerical simulations to study the dynamics of the entry of hydrophobic spheres in a pool of water. To track the air-water interface during the translation of the sphere in the pool of water, we use the volume of fluid model. The continuum surface force method computes the surface tension force. To represent the hydrophobic surface properties, we use wall adhesion in terms of a static contact angle. We perform simulations with different diameters and impact speeds of the sphere. Our simulations capture the formation of different types of air cavities, pinch-offs of these cavities, and other finer details similar to the experiments performed at the same parameters. Finally, we compare the drag force among the different hydrophobic cases. We further perform simulations of hydrophilic spheres impacting the pool of water and compare the drag force with the analogous hydrophobic cases. We conclude that the spheres with hydrophobic surfaces encounter a lower drag than their hydrophilic counterparts. This lower drag of the hydrophobic spheres is attributed to the formation of the air cavity by the hydrophobic surfaces while translating through the pool of water, which reduces the area of the sphere in contact with water. In contrast, no such air cavity forms in the case of hydrophilic spheres.

Overheated children's playgrounds in Central European cities: The effects of surfaces and shading on thermal exposure during hot summer days

Thermal exposure in children's playgrounds is a specific issue in relation to outdoor thermal comfort. In moderate climate regions, playgrounds are prone to overheating on hot summer days. When aiming for a safe design for playgrounds, different thermal conditions with various active surfaces and shading solutions, both natural and artificial, should be considered. Twelve case studies were performed in four Czech cities to quantify the differences in thermal exposure between individual types of active surface and shading, using mean radiant temperature and the biometeorological indices UTCI and PET (plus its experimental child-specific adjustments) as an expression of the thermal environment on hot summer days. The highest thermal exposure appeared above gravel, followed by rubber. Nevertheless, apart from a slightly lower thermal exposure above maintained lawn, substantial positive microclimatic effect of natural surfaces, such as bark mulch, sand, or a small water pool, was not confirmed. In terms of shading, trees provide more pronounced cooling effect than shade sails, but even the latter are effective in substantially reducing heat stress. Analyses of experimental adjustment of PET further indicate the importance of considering the specifics of a child's organism and behavioural adaptation measures when addressing thermal comfort and heat stress in playgrounds.

Experimental investigation of thermal characteristics on a new loop pipe model for passive cooling system

The heat pipes have the potential to be used as a passive cooling system (PCS) in thermal installations including nuclear facilities. In that context, this experimental study is correlated with the research on the new type of Loop Heat Pipe (LHP) as the PCS. This work aimed to study the characteristics of LHP with capillary pipe wick. The experiments involved varying the pool water temperature as evaporator heat load at 35, 45, 55, and 65 °C, filling ratio charged at 20, 40, 60, 80, and 100 % of LHP evaporator volume, and the flow air velocity to the fins in the condenser at 0, 1, 1.5, 2, and 2.5 m/s. The LHP was operated in sub-atmospheric conditions with an initial pressure of 2666.4 Pa. The results show that LHP has a stable two-phase natural circulation under all variations of heat loads, filling ratios, and air velocities tested. The results also show that display excellent thermal performance with the lowest thermal resistance of 0.0524 ± 0.0004 °C/W operating at the highest water temperature source, the highest filling ratio, and the highest air velocity. It is concluded that the LHP model with capillary pipe wick has similar thermal characteristics to other types of heat pipes. This wick function effectively in preventing vapor flow from the evaporator toward the condenser, and otherwise it can facilitate as condensate path from the condenser to evaporator. The stable two-phase natural circulation stability analysis showed that the LHP with capillary wick has very good thermal performance as heat absorber and heat releaser.

Dynamics of a Water Droplet Impacting an Ultrathin Layer of Oil Suspended on a Pool of Water

This study investigates water droplets impacting a two-layered pool, consisting of a deep pool of water above which an ultrathin a suspended layer of silicone oil is present. Initially, the difference between the impact dynamics of water droplets on ultrathin and thick layers of oil were studied. It was found that the existence of an ultrathin layer of oil changes the impact characteristics such how aggressively the jet rises, how the dimensions of the impact impression change, and how the jets are broken down on their tops. Then, in a series of experiments on ultrathin layers of oil, the droplet size, the velocity of the droplets upon impact, and the viscosity of the oil layers were changed to observe and measure the characteristic dimensions of the formed craters and the jets. It was observed that when the viscosity of oil layers decreased to a minimum of 1 (cSt), the jet height and crater sizes increased to their maximum value. In addition to the effect of the oil viscosity, it was found that the droplet size and the release heights of the droplets were in the next orders of significance in determining the impact dynamics. The impacts were also characterized qualitatively by specifically looking into the crown and crater formations, pinch-off modes in jets, and number of formed secondary droplets. As well as the quantitative conclusion, it was found that the major affecting parameter in changing each of these qualities was the viscosity of the suspended oil layer.

Pengaruh Taman Kambang Iwak Kecik Terhadap Tingkat Suhu dan Kelembaban di Masjid Raya Taqwa Palembang

The people of Palembang city know Taman Kambang Iwak (fish pond) as a park for recreation, sports and social contact. Kambang Iwak is divided into two, namely the Kambang Iwak Besak Park (TKIB) and the Kambang Iwak Kecik Park (TKIK). Taman Kambang Iwak Kecik is behind the Taqwa grand mosque Palembang which has a pool that is ¼ the area of TKIB and has a green open space (RTH) which is quite small compared to TKIB. TKIK is surrounded by a 2.5 m wide pedestrian street that has many Tabebuya trees planted. With the fish pond and green open space, of course, the temperature and humidity of the environment affect the level of comfort in the room. Therefore this study aims to determine how much influence temperature and humidity have on the Taqwa Palembang Great Mosque. And descriptive analysis research method with an architectural approach. Data collection was carried out using Hobometers and anemometers. The data was analyzed by comparing it with the ASHRAE standard. It was found that the influence of temperature and humidity on TKIK had quite an effect on the level of comfort, especially during the day when the sun was hot which made the evaporation of the pool water enter the Raya Taqwa Mosque due to the wind blowing from the pool.

Biophysical coupling of seasonal chlorophyll-a bloom variations and phytoplankton assemblages across the Peninsula Front in the Bransfield Strait

Abstract. This study investigates the spatio-temporal variations in the chlorophyll-a (chl-a) blooms in the Bransfield Strait (BS) at a climatological scale (1998–2018). We propose that suitable monitoring of these blooms can be achieved through remotely sensed observations only if the BS is divided following the Peninsula Front (PF), which ultimately influences the phytoplankton assemblage. Our analysis is based on characterizing climatological fields of sea surface temperature (SST), air temperature, sea ice coverage, chl-a concentrations and wind stress, guided by synoptic novel and historical in situ observations which reveal two niches for phytoplankton assemblage: the Transitional Bellingshausen Water (TBW) and Transitional Weddell Water (TWW) pools. The TBW pool features stratified, less saline, warmer waters with shallow mixed layers, while the TWW pool features well-mixed, saltier, and colder waters. We identify that the 0.6 °C isotherm corresponds to the summertime climatological PF location, effectively dividing the BS into two different scenarios. Furthermore, the 0.5 mg m−3 chl-a isoline aligns well with the 0.6 °C isotherm, serving as a threshold for chl-a blooms of the highest concentrations around the South Shetland Islands. For the first time, these thresholds enable the monthly climatological descriptions of the two blooms developing in the BS on both sides of the PF. We think this approach underscores the potential of combining SST and chl-a data to monitor the year-to-year interplay of the chl-a blooms occurring in the TBW and TWW pools contoured by the PF.

Stable Isotopes Constrain Water Seepage From Gnammas Into Bare Granitic Bedrock

AbstractSubtle bedrock depressions called gnammas allow the water in ephemeral pools to maintain contact with bare rock, thus serving as natural rock‐weathering experiments. Following filling by precipitation, evaporation is often assumed to be the sole process of water loss from gnammas. We evaluated this assumption by monitoring evolving stable isotope compositions of gnamma waters hosted in granite of Colorado's Front Range. Surprisingly, we found that a significant fraction of the water was lost by seepage through the underlying bedrock. Seepage dominated, with only 10%–20% loss by evaporation. We propose a conceptual model of gnamma formation in which enhanced weathering of the bedrock beneath the gnamma increases the water holding capacity and permeability of the underlying rock that in turn promotes efficient water loss through seepage and further weathering of the surrounding rock. This model has implications for bare‐rock weathering and hence the evolution of landscapes over geologic timescales.

An Integrated Solution for Nuclear Power Plant On-Site Optimal Evacuation Path Planning Based on Atmospheric Dispersion and Dose Model

Safety in nuclear energy utilization is crucial. In the event of a radioactive release incident, coupled with meteorological uncertainties, a radioactive plume can impact personnel evacuation. This paper presents an integrated solution for radionuclide release accident assessment and emergency evacuation decision making. The solution consists of three processes: atmospheric dispersion calculation, dose calculation, and path planning. The individual processes are connected through data exchange, thus allowing users to choose specific models based on experience. The proposed scheme combination is the Gaussian plume model, the dose conversion factor method, and an improved Dijkstra’s path planning algorithm. This algorithm, combined with dispersion and dose results, weighs nodes using the moving expected dose, facilitating the path with minimum dose risk. A program for Atmospheric Diffusion and Dose Calculation (ADDC) is developed based on the recommended scheme. Advantages include ease of use, minimal data requirements, data accessibility, and efficient evacuation. Dose estimates and optimal evacuation routes can be obtained quickly and at very low cost in response to rapidly changing environmental conditions. In a case study at a Chinese planned nuclear plant, we consider a spent fuel pool water loss scenario, assessing dose risks from 2020 to 2022 meteorological statistics. In dose calculation, results reveal that during an SFP drying accident, the radiation dose in the core area (100 m away) can reach 30–150 mSv within 2 h, and at 500 m away, it can reach 5–15 mSv. The dose in all downwind directions can drop below 250 mSv within 60 m. In path planning, results reveal the program is capable of accurately and efficiently calculating the minimum dose evacuation route. The program’s path reduces the effective dose by up to 67.3% compared to the shortest route, enhancino safety, and guiding post-accident decision making and planning.

A novel cascaded trajectory tracking control for UUVs under time-varying disturbances

In this paper, a novel cascaded trajectory tracking control strategy based on the characteristics of kinematics and dynamics is proposed for unmanned underwater vehicles (UUVs) under complex disturbances. A kinematic controller based on an improved model predictive control (MPC) is designed to solve the speed jump problem by considering system constraints. Moreover, an improved whale optimizer with elite strategy (EIWOA) is used to the rolling optimization process of MPC, ensuring that the global best solution is derived by obtaining the elite individuals in the population. Besides, a dynamic controller that consists of an adaptive disturbance observer and a fuzzy integral sliding mode control (ADO-FISMC) is proposed to obtain optimal thrust force under time-varying disturbances. The benefit of ADO lies in that it can estimate time-varying disturbances without specific information about disturbances. The fuzzy logic system is introduced to alleviate the chattering of sliding mode control. The simulation results demonstrate the great tracking performance of the cascaded trajectory tracking controller. The viability of the proposed algorithm is also confirmed by trials conducted in water pools.