Agricultural practices in drylands need to be continuously encouraged so that communities can utilize existing efficient irrigation technology. Irrigation tests on perforated pipe networks need to be conducted to test the distribution of secondary discharge due to the addition of pipe length in the lateral network of the perforated irrigation system. The test was conducted to determine the ability of the irrigation system to provide flow discharge in the primary and secondary pipe networks and the approach to calculating the perforated discharge network. The irrigation test was conducted on three lateral perforated pipe networks with a diameter of ½” and a perforation hole distance of 0.6m, a water tower with a capacity of 200 liters and a height of 4 meters. The perforated flow discharge was analyzed using basic data in the form of head and network design, the results of the analysis were presented in graphs and tables. The results showed that the secondary network flow rates decreased as the network moved further from the water source. An average increase in flow rate of 0.004 l/s was observed for each 0.1 m increase in head. The distribution of secondary flow rates, with variations in pipe length every 60 cm from hole 1 to 6, resulted in decreasing flow rates. In secondary network 1, the flow rate was 0.301 l/s–0.239 l/s, in secondary network 2, the flow rate was 0.276 l/s–0.226 l/s, and in secondary network 3, the flow rate was 0.267 l/s–0.221 l/s. The difference in secondary flow rates across pipe holes 1 to 6 obtained in secondary 1 was 0.06 l/s, in secondary 2 was 0.052 l/s, and in secondary 3 was approximately 0.049 l/s.

The growth of wall-mounted ice within channel flow which leads to a constriction is of significant practical relevance, especially in applications relating to aero-icing, large-scale pipe networks and mechanical systems. Whilst earlier works have treated ice constrictions as independent of the oncoming flow, few models explicitly account for the two-way coupling between the thermal and dynamical properties of the fluid and the evolving ice. To this end, the present work seeks to describe the interaction between high-Reynolds-number channel flow and constricting ice boundaries governed by Stefan conditions. Numerical simulations of the model indeed reveal that ice forming on the channel walls grows inwards towards the centreline and subsequently creates almost total constriction. In other parameter regimes, however, there is no ice formation. Using both a numerical and asymptotic approach, we identify regions of parameter space in which ice formation, and subsequently flow constriction, does or does not occur.

In coronary artery disease (CAD), the initiation, progression, and regression of atherosclerosis remain incompletely understood, limiting the effectiveness of specific diagnostic and personalized medicine management strategies based on current imaging and assessment methods. In this scientific rationale and study design analysis, the framework conceptualizes the cardiovascular system as an integrated hydraulic network of pumps and pipes, advancing a shift from static imaging of luminal stenosis toward dynamic assessment of coronary flow. Grounded in fluid mechanics and acoustic principles, this analysis establishes a scientific rationale for an angiographic investigation of hemodynamic disturbances that compromise endothelial integrity in coronary arteries. The first section examines injury arising from repetitive flexion and extension of coronary segments driven by left ventricular contraction, most prominent at the transition from diastole to systole. The second section evaluates the hypothetical effects of thickened boundary layers and intimal injury caused by oxygen deprivation along the proximal portion of the outer curvature of side branches. The third section explores the hypothetical role of recirculating flow in accelerating lesion development at these sites. The fourth section presents an acoustic-based diagnostic framework for assessing the hypothetical impact of retrograde pressure-wave propagation associated with water-hammer phenomena. Collectively, these mechanisms establish the systematic codification and spatial delineation of coronary lesions as represented on the coronary acoustic map. Building on these insights, the present analysis proposes a clinical trial framework integrating AI-driven algorithmic protocols to rigorously assess the diagnostic performance and predictive accuracy of the coronary acoustic map.

The safety of drinking water quality is crucial for public health and social stability. This study systematically assessed the tap water quality in a typical sub-new residential area in Guangzhou, comparing different water supply modes. Five sampling points were established in villa and high-rise areas to analyze key indicators including chromaticity, turbidity, pH, total hardness, total dissolved solids, chloride, and permanganate index. Results indicated that the drinking water quality generally met the Sanitary Standard for Drinking Water (GB 5749-2022). However, the turbidity at the outlet of the secondary water supply system reached 1.2 NTU, exceeding the standard limit. Further analysis revealed that organic matter content and turbidity within the residential area were significantly higher than at the municipal control point. Total dissolved solids and organic matter levels increased notably in morning samples due to pipeline detention effects. The villa area exhibited greater water quality fluctuations compared to the high-rise area, likely due to its pipe network structure and hydraulic conditions. This study provides a scientific basis and practical recommendations for refined water supply management and water quality risk prevention in similar residential areas.

ABSTRACT Water quality parameter measurement has always been a hot issue in the field of industrial measurement as an important link in water environment governance. Recent studies on the measurement of specific conductance (SC) and Pondus Hydrogenii (pH) in sewage pipe networks have become increasingly mature. However, the limitations of existing methods, such as limited accuracy, poor stability, and the complexity of sensor preparation and operation, have restricted their application in actual working conditions. Electrical resistance tomography (ERT), a novel multi-phase flow measurement technology, has received widespread attention in the industrial measurement field due to its non-invasive, fast response, no radiation, and visualization features. This paper proposes a novel non-invasive SC and pH measurement method based on ERT, which is based on the principle of electromagnetic fields, and derives the linear relationship between SC and ERT boundary measurement values and the constitutive equation between the pH and ERT boundary measurement values based on the ionic SC characteristics of the solution. The method proposed in this paper is capable of detecting water quality parameters in a non-invasive manner that is more green, accurate, real-time, and sensitive, and offers a novel idea for non-invasive measurement of sewage pipe networks.

The role of air pressure transients on the spread of bacteria from wash-hand basin sink traps in hospital en-suite bathrooms: a laboratory-based pilot study.

Reverse Engineering of Impellers to Reduce Pipe Network Pressure and Enable Sustainable Power Generation Using Pumps as Turbines (PATs)

Access to clean, hygienic, and sufficient potable water is a concern in many countries. To ensure this, asset management, planning, and structured pipe renewal are crucial in providing an adequate level of service. However, there is a significant backlog in municipal pipe renewal, which needs to be addressed to raise the standard of potable water supply to an acceptable level in countries across most continents. Therefore, the objective of this research was to improve decision-making to reduce this backlog. Competent personnel are a scarce resource and not easily replaced. Standardized decision-making is considered an efficient approach to addressing the shortage of skilled personnel in pipe renewal. However, its effectiveness depends on its adaptability to the varying complexity and scale of such projects during implementation. This research is based on a literature review that explores decision theories, project definitions, and project models, and compares the typical characteristics of pipe renewal projects with those of other infrastructure projects. The research highlights that structured and standardized decision-making processes are essential to ensure appropriate asset management of the pipe network and sufficient pipe renewal. The main outcome of this research is a tailored project model that supports better front-end decision-making in pipe renewal projects through improved information flow.

The purpose of this study was to determine the condition and system of domestic wastewater piping in Mekarsari Village. This type of research is a case study in Mekarsari Village related to the condition of the Wastewater Treatment Plant (IPAL). The results of the study indicate that the piping system uses a gravity system, a wastewater distribution system in Mekarsari Village that channels wastewater from higher areas to lower areas. This system is commonly used because it does not require additional energy. This end system uses a pipe network connected to the Wastewater Treatment Plant (IPAL) to treat wastewater before being reused. The condition of the domestic wastewater piping in Mekarsari Village is still in good or normal condition. Leaks or loss of discharge have not been found, this is because the pipes used are iron pipes.

Old urban districts, characterized by complex drainage networks, heterogeneous surfaces, and high imperviousness, are particularly susceptible to flooding during extreme rainfall. In this study, the moat drainage district of Xi’an was selected as the research area. A refined hydrologic–hydrodynamic simulation and an assessment of drainage and flood-retention capacities were conducted based on the coupled GAST–SWMM model. Results show that the model can accurately capture the rainfall–surface–pipe–river interactions and reproduce system responses under different rainfall intensities. The box culvert’s effective regulation capacity is limited to 1- to 2-year return periods, beyond which overflow rises sharply, with overflow nodes exceeding 80% during a 2-year event. The moat’s available storage capacity is 17.20 × 104 m3, sufficient for rainfall events with 5- to 10-year return periods. In a 10-year return period event, the box culvert overflow volume (12.56 × 104 m3) approaches the upper limit, resulting in overtopping. These findings provide a scientific basis for evaluating drainage efficiency and guiding flood control management in old urban districts.

Free chlorine residual is the most widely adopted disinfectant residual in water supply systems. Chlorine is usually applied at treatment works, but it decays as water flows and spends time within the network. Chlorine decay is the result of a bulk and a wall decay component. Bulk decay may be considered invariable through the pipe network (it only depends on water composition) and is often characterized at the entrance to the system through bottle tests, which measure chlorine evolution over time in a laboratory environment to then adjust a model (dependent on one or more coefficients) that represents its behavior. Previous studies have acknowledged that the bulk decay coefficient varies widely and that free chlorine measurements are subject to measurement errors, but they have not quantified the impact of these errors on the bulk decay coefficient. The aim of this paper is to provide a methodology that statistically fits chlorine’s bulk decay coefficient based on bottle test results, with appropriate management of uncertainty effects. The proposal is to use state estimation techniques, which combine free chlorine measurements and system knowledge (in this case, a first-order bulk decay model) to provide the most likely chlorine behavior and its associated uncertainty. This approach goes one step beyond previous studies, which report only a single value of the bulk decay coefficient without accounting for randomness, and thus fail to assess true variability, leading to unrepresentative comparisons. Results for water samples from different sources demonstrate the importance of controlling the fitting process through state estimation to understand and compare the bulk decay coefficient.

Watudiran Village in Sikka Regency is a semi-arid area experiencing limited access to clean water due to the absence of an adequate piped water network. To develop an effective and sustainable clean water pipeline project, various baseline data are needed to support technical planning and guide appropriate investment decisions. This study aims to analyze clean water demand based on projected population growth and domestic water consumption standards. The method involves population projection using a geometric growth model and water demand estimation based on government standards, assuming a daily per capita consumption of 60 liters per person. The analysis covers the period from 2024 to 2039. The results show that the population of Watudiran Village is projected to increase from 1,871 people in 2024 to 2,559 people in 2039. Based on this assumption, the average daily water demand will reach 153,522 liters by the end of the projection period. The peak flow is estimated at 3.56 liters per second, using a peak factor of 2.0. These findings provide a quantitative foundation for designing the village’s clean water distribution system and serve as a key reference for rural infrastructure development planning.

Correction: Methods to monitor the defects of the drainage pipe network: a review

Influence of the Reconstruction of Rainwater and Sewage Diversion Pipe Networks on Urban Inundation

Background: Colonoscopy is a key technique for the prevention and early detection of colorectal cancer. Water-assisted colonoscopy is increasingly adopted due to its potential to reduce patient discomfort. However, the temperature of the infused water plays a crucial role in both procedural quality and patient experience. This study aimed to optimize water-assisted colonoscopy by developing a constant-temperature water infusion system. Methods: A two-dimensional finite element model was established using COMSOL Multiphysics to simulate the heat transfer process between the heating base and the liquid container. The system consisted of a medical-grade 304 stainless steel container, a nichrome heating wire embedded in rubber, and an integrated piping network. Quadrilateral meshing was applied to short-range solid–liquid interfaces and triangular meshing elsewhere, resulting in detailed modeling for both natural heating (27,801 elements) and circulation heating (43,998 elements). Based on simulation results, a hardware platform was developed to deliver sterile water at a constant temperature of 37 °C for digestive endoscopic procedures. Results: Circulation heating demonstrated superior thermal efficiency and more uniform temperature distribution than natural heating. Under ambient conditions (25 °C ), the system reliably maintained water temperature at (37±1)°C . Partitioned meshing enhanced computational precision with a minimum element size of 0.1 mm. Solid-liquid coupling analysis confirmed stable heat conduction during dynamic infusion. The device allows for independent temperature presetting and stepless flow rate adjustment via a control panel. It is also compatible with standard endoscopic systems, thereby enhancing procedural efficiency and safety. Conclusion: The proposed constant-temperature water infusion system model offers a reliable and adaptable solution for water-assisted colonoscopy, improving both diagnostic performance and patient comfort through precise thermal regulation.

Performance optimization in groundwater supply systems promotes operational efficiency by reducing energy use and maintaining adequate water flow and pressure, leading to cost savings and prolonged equipment lifespan. In Nadowli township, groundwater is a vital water source for the community. However, rapid population growth, climate variability, and increasing water demand have placed significant pressure on the existing small-town pipe water system. The system faces inefficiencies such as high energy consumption, excessive head loss, and inadequate flow rates, leading to water rationing and production shortfalls. This study focuses on optimizing the Nadowli Water Supply System to minimize energy consumption while ensuring that key hydraulic parameters (flow rate, head loss, and velocity) are maintained within acceptable limits to meet the demand gap of the town. The research utilized EPAnet 2.2 to simulate the hydraulic performance of the Nadowli Water Supply System, analyzing velocities, flow rates, and head losses across the network. The Flowius application was the data collection tool employed. A Genetic Algorithm (GA) optimization technique was then applied to minimize energy consumption by adjusting pipe diameters. The objective function integrated hydraulic constraints such as flow rate, velocity, and head loss to ensure system efficiency while reducing operational costs. The optimization resulted in a significant reduction in energy consumption by the pumps, with values decreasing from 0.48 kWh/m³ to 0.35 kWh/m³ for PU-1, 0.48 kWh/m³ to 0.37 kWh/m³ for PU-2, and 0.52 kWh/m³ to 0.42 kWh/m³ for PU-3. Resulting in an average of 0.11 kWh/m³, while head loss decreased from 12.31 m/km to 7 m/km The optimization study also led to a 22 % reduction in daily production costs and an 83.9 % decrease in operational hours, with total pump operation time reduced from 149.64 hours/day to 24.09 hours/day. The findings therefore showed the importance of optimizing pipe networks and pump efficiency to ensure sustainable, cost-effective groundwater supply systems.

In recent years, with the frequent occurrence of extreme climate events and the acceleration of urbanization, the problem of urban waterlogging has become increasingly serious, which seriously threatens the safety of residents􀆳 lives and property. Urban waterlogging simulation is an important technical means for waterlogging warning and drainage system optimization. Among them, the storm water management model (SWMM) is widely used because of its open source and dynamic simulation ability. However, the model usually relies on measured hydrological data for parameter calibration, and most small and mediumsized cities are limited by monitoring facilities and lack reliable measured data, which restricts the accuracy evaluation and practical application of the model. In order to solve the above problems, this study takes the northern area of Taihe County, Anhui Province as the research area, and proposes a method for calibrating SWMM model parameters based on SAR images, which provides technical support and method reference for flood control planning and drainage facilities optimization in small and medium-sized cities. The SAR image is used to calculate the Sentinel-1 Dual-Polarized Water Index (SDWI) , and the actual submerged area is extracted by Otsu method. The parameters of the simulation results are calibrated by spatial overlap analysis, recall rate and accuracy. Using the submerged range extracted from SAR images as a verification, the recall rates of the constructed SWMM model in typical areas reached 79. 35% and 84. 69%, respectively, and the accuracy rates reached 71. 89% and 72. 53%, respectively, which verified the applicability and reliability of the model. Subsequently, the waterlogging simulation under 5-year, 10-year and 20-year return period rainfall scenarios was carried out. The simulation results revealed that with the increase of rainfall return period, the inundated area and moderate to severe water accumulation nodes in the study area increased significantly. By comparing and analyzing the spatial distribution of water accumulation range and the overload of pipe network and nodes, the characteristics of urban waterlogging and water accumulation in the study area are systematically revealed.

ABSTRACT Methane explosions can cause significant losses in coal mines. To investigate cost-effective powder explosion suppressants, glucose acid-modified sepiolite powder with hydroxyl functional groups was prepared using sepiolite powder as the raw material. The explosion suppression effect of sepiolite powder before and after modification was studied in a self-made explosion pipe network experimental system. The results show that both pure sepiolite powder and modified sepiolite powder have good explosion suppression effect, and the explosion suppression effect of modified sepiolite powder with hydroxyl functional groups is better. Compared to the blank control group (without powder), the values at each measurement point of the powder before and after modification showed a significant downward trend. The maximum explosion pressure peaks of the sepiolite powder before and after modification decreased by 76.15% and 80.69%, respectively. The maximum flame propagation peak speeds decreased by 263.38 m/s and 296.98 m/s, respectively. The maximum flame propagation peak temperatures decreased by 637.77 K and 1029.20 K, respectively.

Clean water distribution in the Community-Based Drinking Water Supply and Sanitation Program (PAMSIMAS) in Kuwasen Lama Village, Gunungpati District, Semarang City, faces the challenge of unequal supply between highland and lowland areas. The main factors that affect these conditions include differences in topography, suboptimal piping network design, and unbalanced water pressure, especially during peak hours. This research proposes a solution based on Internet of Things (IoT) technology using the ESP32 module as a control center, which is integrated with the Blynk application for real-time monitoring and control of the system. The system is equipped with a water flow sensor, water level sensor, motorized valve, and booster pump to increase water pressure in high elevation areas. Two design schemes were tested, namely flow regulation using a motorized valve, and a combination of a motorized valve with a booster pump. The results of the simulation and implementation showed an increase in water pressure stability, equitable distribution, and a decrease in the frequency of supply disruptions. The system also allows for live monitoring of network conditions, facilitates technical decision-making, and improves operational efficiency. With an adaptive and community participation-based approach, this solution has the potential to become a model for PAMSIMAS clean water distribution management that is efficient, sustainable, and responsive to geographical challenges, while strengthening the resilience of clean water services in rural areas.

Physics-informed neural networks involving unsteady friction for transient pipe flow.