Piped water to private houses is today normal in many countries. This thesis has demonstrated that Pompeii had piped water distributed in lead water pipes to private houses based on gravity flow already in antiquity. This modernity was introduced in the western world with pump technology after the industrial revolution, in Stockholm about 1870 AD. The water system in Pompeii is a remarkable technological achievement made in antiquity without formal scientific knowledge in hydraulics. The system in Pompeii was however not a model for water distribution in antiquity. In three other ancient cities water pipe connections to private houses are unknown or not investigated. The purpose of this article is to describe this innovation by summarizing conclusions from three studies of the water distribution system in Pompeii published by the author. The thesis has studied water systems in ancient cities not only based on archaeological remains but also on hydraulic engineering analysis. The first study investigated the route of the water system based on the water levels in the top containers and on the technical principle for gravity flow. These levels have not been discussed before. The size and orientation of the grooves in the water towers were also investigated and three not yet excavated but possible water towers were indicated. In the second study modern hydraulic analysis was used to show how balance in the system could have been achieved. The interplay between water flow and pipe dimension has not been discussed before. The third study discussed the ability of the water distribution system to supply water to all water users by introducing a calculation method for water quantities to users. This was to demonstrate how aqueduct water could reach all water users provided that the pipe dimensions were small enough. Larger pipes would have emptied the system. The conclusion is that Pompeii had piped water to private houses already in antiquity.
Eiderdown, as a high-quality natural insulating material, is widely used in everyday life to make down products, and there is a huge market demand for them. However, the wastewater generated during the processing of eiderdown is characterized by a high concentration of fine down fibers and elevated phosphorus levels. Given the characteristics of the wastewater, this project employs a “bar screen + air flotation” pretreatment process to remove residual fibers and ensure the proper operation of subsequent treatment processes, followed by “Anaerobic-Anoxic-Oxic (A 2 /O) + chemical phosphorus removal” to achieve nitrogen and phosphorus removal. Operational results show that the influent water quality is chemical oxygen demand (COD Cr ) ≤ 150 mg/L, suspended solids (SS) ≤ 500 mg/L, total nitrogen (TN) ≤ 30 mg/L, and total phosphorus (TP) ≤ 120 mg/L, while the final effluent water quality is COD Cr ≤ 55 mg/L, SS ≤ 60 mg/L, TN ≤ 15 mg/L, and TP ≤ 0.5 mg/L, consistently meeting the Class I standards of “Integrated Wastewater Discharge Standard” (GB 8978-1996). The actual operating cost is 0.67 yuan per cubic meter. More than 95% of the treated water can be reused in the plant’s primary washing section and other processes, enabling the recycling of water resources and demonstrating significant economic viability. This process provides valuable insights for wastewater treatment in related industries.
This study investigates the capability of an Artificial Neural Network (ANN) model to estimate daily ETo using several meteorological variables in a data-limited region along Guyana’s coast. The ANN was trained on historical data from 2001–2018 and independently evaluated over 2019–2022, with ETo computed by the FAO Penman–Monteith (PM-56) method serving as the reference benchmark. Model performance was assessed using standard statistical indicators, including the root mean square error (RMSE), mean absolute error (MAE), coefficient of determination (R 2 ), Nash–Sutcliffe efficiency (NSE), and index of agreement (IoA). In addition, the ANN model was compared against 32 commonly used empirical ETo estimation methods, encompassing temperature-based, radiation-based, and mass transfer-based approaches. Results indicate that the ANN reproduced PM-56 ETo estimates with high accuracy and minimal bias, achieving R 2 and NSE values exceeding 0.99 across the validation period. The ANN model also consistently outperformed all empirical methods across all performance metrics, demonstrating superior accuracy and robustness. Among conventional methods, the Hargreaves–Samani and Makkink approaches showed comparatively better performance, while mass transfer-based methods exhibited substantial deviations and poorer performance. These findings suggest that ANN-based models can serve as reliable alternatives for daily ETo estimation in regions where complete meteorological inputs for physically based methods are limited, thereby supporting improved water-resource and agricultural decision-making in Guyana and similar environments.
The Thermohaline Convection-Enhanced Solar Membrane Distillation (TSMD) system is introduced as an innovative and sustainable solution to global water scarcity, designed to operate entirely off-grid using renewable energy sources, primarily solar thermal power, for an optimal eight-hour daily cycle. Unlike conventional desalination systems dependent on grid electricity or fossil fuels, the TSMD incorporates a 12 V DC submersible pump powered by a 15 W solar panel, a 12V-7Ah battery ensuring semi-autonomous operation in remote or resource-limited regions. The design integrates thermohaline convection and a pump to enhance heat and mass transfer, improving evaporation and condensation efficiency. Experimental results from hardware testing indicate a freshwater production rate of approximately 5.4 L of freshwater from 10 L of feedwater (54% water recovery), with brine discharge maintained at about 4.6 L. Total Dissolved Solids (TDS) levels were significantly reduced, reaching as low as 109 ppm, far below the WHO drinking water threshold of 300 ppm. Under peak sunlight conditions, the system achieved a thermal efficiency of approximately 62%. These findings demonstrate that the TSMD system is environmentally friendly, and its energy-independent design makes it a strong potential for solving the freshwater shortages in arid, semi-arid, and off-grid communities around the globe.
This study conducted slope and seepage stability analysis of a rock fill dam by comparing the clay core geometry. The core geometry in this study has been changed from a vertical to an inclined arrangement, and all analyses have been conducted are compared with the original design. The geometry of the inclined clay core dam was fixed and checked for static loading conditions. The analysis has been conducted using numerical modeling software called GEO-Studio 2012. Based on calculations, the flux through the dam with an inclined clay core is 0.0057 m3/sec, while the flux from the original dam with a vertical core is 0.0073 m3/sec. The safety factors for the downstream slope during steady state, sudden drawdown, end of construction, and the construction stage are 1.72, 1.56, 1.53, 1.64, and 1.59, respectively. These values were obtained from the original dam design with a vertical clay core, and the corresponding safety factors are 1.63, 1.54, 1.63, and 1.57, respectively. Therefore, the geometry of the clay core is considered safe based on the allowable limit factor of safety and seepage. In addition to this, the inclined clay core section was found to be significantly more Economical compared to the vertical clay core.
