Water Discharge Research Articles

Quality assessment standards and production technology of artificial sand based on hydraulic concrete construction specifications

Natural sand and gravel resources are a local resource. Natural sand and gravel are non-renewable in a short time and are not suitable for long-distance transportation. After decades of mining, sand and gravel resources in some areas have been exhausted. The transportation distance of natural sand and gravel is getting farther and farther, and accordingly, the price of natural sand and gravel continues to rise. At the same time, continuous and disorderly mining has caused serious damage to the environment and resources. During the construction of large and medium-sized water conservancy and hydropower projects in China, due to the lack of surrounding natural aggregates, most projects use artificial aggregates. In the current national standards for water conservancy projects, the content of artificial sand and gravel powder is clearly defined. Based on the “Hydraulic Concrete Construction Specifications” (SL677-2014), this article summarizes the particle shape, gradation and surface structure of artificial sand, and also calculates the theoretical gradation of artificial sand. To find out the impact of stone powder content on the performance of artificial sand, different levels of stone powder content need to be selected for research and analysis to clarify the impact of artificial sand powder content on concrete properties. Research shows that for concrete made from artificial sand, increasing the aggregate content with a particle size less than 0.075 mm can significantly increase the compressive strength of the concrete. In artificial sand, the content of stone powder will affect the workability, polishability, durability, permeability and water release of concrete. In the artificial sand and gravel production process system, crushing and sand making equipment are the most important sand and gravel production equipment. The research results provide theoretical reference for the application of artificial sand in concrete and the update of artificial sand production technology and equipment.

Effect of manifold size on PEMFC performance with metal foam flow field

Metal foam flow fields are considered as an alternative to conventional channel/rib flow field in polymer electrolyte membrane fuel cell (PEMFC) because of the advantages of three-dimensional pore structure. In this study, the effect of metal foam flow field with different manifold size on PEMFC performance was investigated, with a 25 cm2 unit cell. Polarization curve and electrochemical impedance spectroscopy results were analyzed to investigate the effects of gas stoichiometry and relative humidity on performance. The mass transfer loss was decreased with reduced manifold size. However, mass transfer loss was increased due to difficulty of water discharge in small manifold case. The metal foam flow field offer advantages in water discharge and mass transfer loss. At 100% relative humidity, performance was improved with increased air stoichiometry for different manifold size. At 25% relative humidity, performance was a little improved with increased air stoichiometry for small manifold case. Regardless of relative humidity, fuel cell performance with metal foam flow field was most improved in case of smallest manifold size based on air stoichiometry due to the high pressure drop.

Sonoprocesses for sustainable textile processing and nanofinishing: a review

The textile sector is widely acknowledged as one of the most environmentally damaging sectors globally, primarily due to its high consumption of water and energy, utilization of chemicals, and the discharge of waste water containing a complex mixture of hazardous substances. The incorporation of nanotechnology, particularly through wet processes involving nano finishes, while enhancing textile functionality, further exacerbates these environmental concerns. Consequently, the exploration and promotion of sustainable methodologies are imperative across all wet treatments in textile processing. Among the potential solutions, sonoprocesses stand out as a promising avenue for mitigating resource consumption, and supporting environmentally friendly synthesis and application of nanomaterials to textiles. Sonoprocesses offer the advantage of carrying processes at low temperature and pressure, and the use of aqueous media instead of organic solvents. This comprehensive review delves into the multifaceted applications of sonoprocesses within the textile realm, with a specific emphasis on the synthesis and application of nanomaterials to textiles. Discussing the diverse applications of sonoprocesses, this study will pave the way for the integration of these techniques within the textile industry, ultimately aiming for widespread adoption on a commercial scale. This will help in promoting sustainable practices and reducing the ecological footprint of the textile sector.

Effect of agriculture on surface water quantity and quality in Gilgel Gibe watershed, southwestern Ethiopia.

Monitoring water quality and quantity is crucial to be sure that water resources are sustainably used. However, there is no monitoring system of water quantity and quality in southwestern Ethiopia, despite expansion of agricultural activities demanding water resources. The objective of this study was to investigate the effect of agriculture on water quantity and quality with special emphasis on irrigation in southwestern Ethiopia. Data of water quantity was collected from four rivers and four irrigation canals during dry season of 2023. Physico-chemical water quality data was collected from 35 sites. Water quantity was calculated by estimating the water discharge of the rivers and irrigation canals. Weighted arithmetic water quality index was calculated to assess the status of the studied rivers. Principal component analysis was used to identify the relation of the sites with water quality parameters. This study revealed that the average amount of abstracted water for irrigation from the four studied rivers was 22,399 m3/day during the studied period, and the average percentage of abstracted water was 17%. Sites downstream of the irrigation site were characterized by poor water quality compared with the upstream sites. Sites surrounded by agricultural land use were correlated with chemical oxygen demand, electric conductivity, nitrate, orthophosphate, water temperature, and pH, whereas all sites surrounded by forest were positively correlated with dissolved oxygen. This study indicates that agricultural activities have a negative impact on surface water quality and quantity if not managed properly. Hence, we recommend sustainable use of water resources for the planned irrigation expansion.

Water consumption of corn under different methods of primary tillage after row-crop predecessors on an energy-storage soil maintenance system

The object of research was the light chestnut soil of the Chokh Agrofirm of the Gunibsky district in the Kizilyurt transhumance zone of the Republic of Dagestan. The humus content in the arable layer is 2.77%, P2O5–2.21, K2O – 32.8 mg/100 g, the density of the arable soil layer is 1.24 g/cm3, the lowest moisture capacity (MC) is 29.2% (layer 0–0.6 m). The effectiveness of two row-crop predecessors was studied: sunflower for seeds and corn for grain, and the use of skimmers in the main tillage for corn. Soil moisture, watering and irrigation standards, incoming and outgoing items of the water balance and the coefficient of water consumption for corn were determined. In the second ten days of May, the plant remains of predecessors were crushed using double disking with heavy disc harrows BDT-3, plowing was carried out to a depth of 0.28–0.30 m with a PLN-4-35 plow with and without skimmers, the field was leveled with a small leveler MV – 6 and watered at the rate of moistening the soil layer of 0–0.6 m in strips with lateral release of water manually, vegetation irrigation was carried out in furrows. Sunflower sowing was carried out with seeds of the VNIIMK-8883 variety, corn – hybrid ROSS-299, the seeding rate for both crops was 72 thousand seeds/ha. Fertilizers for sunflower were applied at the rate of N90Р40К90, including N40Р24К74for plowing, N16Р16К16– when sowing with seeds, N34for fertilizing in the phase of 5–6 leaves when cutting furrows, for corn – N90Р40, of which N40Р24for plowing, N16Р16К16when sowing with seeds, N30in fertilizing in the phase of 3–5 leaves. It has been established that in the areas of irrigated agriculture of the Western Caspian region, when selecting row-crop predecessors for corn for grain, preference should be given to early-ripening varieties of sunflower for seeds, which are harvested in the third decade of July, and after harvesting it remains in the soil more than 15 t/ha of plant mass. At the same time, the maximum corn yield is achieved – 9.16 t/ha of grain, exceeding the control by 33.1%, due to which, with the same total water consumption as the control option, the water consumption coefficient is reduced by 23.7%.

Experimental study on dewatering and reinforcement of dredged slurry treated by PHDs-PVDs under step vacuum preloading

Nowadays, the utilization of prefabricated vertical drains (PVDs) or prefabricated horizontal drains (PHDs) in combination with vacuum preloading (VP) has emerged as a prevalent and effective strategy for treating dredged slurry. Nevertheless, both of these methods possess certain inherent limitations. In this study, three groups of parallel model experiments are conducted to compare the effectiveness of PVDs, PHDs and PHDs-PVDs under step VP in treating dredged slurry. Firstly, the water discharge, settlement and pore water pressure are monitored during the experiments. Then, the shear strength and water content of the soil at various locations after experiments are measured and the soil profiles at different cross sections are gauged. Additionally, soil excavation is conducted to evaluate the deformation characteristics of PHDs and PVDs. Finally, a scanning electron microscopy analysis is to assess the clogging of filter membranes. The results indicate that the proposed method can combine the advantages of both PHDs and PVDs, effectively enhancing the treatment effectiveness of the slurry. These findings elucidate the dewatering and reinforcement mechanism of PHDs-PVDs-VP and provide valuable insights for its practical engineering application.

Effect of hot water and corona discharge treatments on the bonding behavior of jute fibers in polyester matrix

Effect of hot water and corona discharge treatments on the bonding behavior of jute fibers in polyester matrix

Influence of establishment methods and seed coating techniques on the performance of direct seeded rice (Oryza sativa L.) under Periyar Vaigai command area of Tamil Nadu

Rice is a crucial staple crop cultivated extensively in command areas worldwide. In the command areas, the release of water varies due to the inadequate amount of rainfall in the source area and its proper supply. To combat such situations, direct seeding (DS) methods can be opted for; however, lacunae like excess seeds per drop, scattering of seeds, and intercultural operations like thinning, gap filling, and excess weed growth need a clear refinement to enhance the profitability of rice cultivation. Therefore, a research trial was conducted during 2022-24 at Central Farm, Agricultural College and Research Institute, Madurai, to evolve a suitable direct seeding method. The present investigation was laid out under a split-plot design comprising four main plot treatments and four subplot treatments replicated thrice. The main plot treatments comprised different seeding methods (S) and the subplot treatments comprised different seed coating techniques (P). Based on the experimental results, paper roll seeding and DS + Seed coating @ 2% KNO3 fb Bacillus sp. and Azospirillum (PR + P-KN) combination performed better on establishment with grain (6150 kg/ha) and straw yield (7824 kg/ha) respectively. Regarding the B:C ratio, OS-GP + P-KN resulted in higher with 2.64, closely followed by PR + P-KN with 2.61. The least effect was recorded in the combination of round slots in rice drum seeder and dry seeding (RS + DS). Investigating different techniques of direct seeding and seed coating is essential across various regions, particularly in regulated areas where water discharge remains unpredictable.

Irradiation-assisted synthesis of smart hydrogels based on nanomagnetic semi-interpenetrating p(HEMA)/PVP networks for the cleaning of cultural heritage artifacts

Preservation of our cultural and historical heritage as a testimony to our shared past is a responsibility that demands significant attention. One of the most critical and delicate aspects of conserving such treasures is cleaning them safely and effectively. Chemical hydrogels specifically designed for cleaning cultural heritage artifacts allow for the containment and controlled release of water. Based on a generic approach, a smart nanomagnetic hydrogel was developed using a semi-interpenetrating polymer network (semi-IPN) of polyhydroxyethyl methacrylate (p(HEMA)) and polyvinyl pyrrolidone (PVP). Gamma irradiation was employed to perform simultaneous in-situ polymerization, crosslinking, and also immobilization of iron oxide magnetic nanoparticles (MNPs). The chemical and structural characteristics of the nanomagnetic hydrogel were investigated using gel content, equilibrium water content, field-emission scanning electron microscopy, magnetic properties, compressive strength, dehydration kinetics, and adhesion tests. The optimal formula for smart hydrogel was a ratio of monomer to polymer 50:50, a water content of 60 wt.%, a gamma radiation dose of 20 kGy, and 3 wt.% of MNP. Two cotton canvas case studies demonstrate the versatility and effectiveness of the selected hydrogel in removing dirt and confining the water-based cleaning system. It was found that no color leaching occurred during the cleaning process.

Optical characterization of nanosecond-pulsed discharge in liquid nitrogen

We report the optical characterization of nanosecond-pulsed plasma ignited directly in liquid nitrogen. Using imaging and optical emission spectroscopy, we estimate neutral temperatures and densities, as well as local electric field values, and the obtained results indicate that the discharge develops via streamer (‘electronic’) mechanism. We show that millimeter-scale plasma propagates in liquid nitrogen at velocities of ∼500 km s−1 with the corresponding required local electric fields as high as 25 MV cm−1, while the estimated local electric fields in the ‘core’ of the discharge are around 6–8 MV cm−1 (corresponding to reduced electric field values of 600–1000 Td). The neutral and electron densities in the ‘main body’ of the discharge were estimated using broadened argon lines, indicating that the neutral densities in the near-electrode region are around 1020 cm−3 (tens of atmospheres), while the maximum recorded temperature is just a few tens of degrees above the surrounding liquid. Electron densities were estimated to be ∼1017 cm−3, about two orders of magnitude lower than those measured for water discharge.

IoT-Based Disaster Monitoring and Management System for Dams

Dams hold great significance due to their role in generating hydroelectricity and facilitating irrigation. Over the years, numerous dams have been constructed in various locations, but their existence presents several risks. Consequently, it is crucial to establish an effective monitoring and management system for dams to maintain safe water levels and prevent man-made disasters. At present, dams in our state are managed manually, which can lead to errors and decision-making delays. This project aims to design and implement an IoT-based Disaster Monitoring and Management System for Dams . The system will monitor water levels in real-time for a group of dams, taking into account factors such as changes in water levels of connected rivers or lakes and excessive rainfall in the catchment area. The proposed an IoT-based Disaster Monitoring and Management System for Dams includes a mechatronics system that automatically adjusts shutter heights based on pre-calculated values. The system comprises sensor nodes, a smart controller, and a communication system, and operates in two modes: Autopilot and Manual data. The app-based IoT system will monitor and transmit real-time parameters related to dam conditions (gate position, water discharge, water level) and weather conditions (rainfall, temperature, humidity). Furthermore, the system will provide SMS alerts to local residents and SOS alerts to rescue operations during adverse weather conditions.

SCADA implementation in microhydro power plant control and monitoring systems of screw turbine type

Screw turbine-type micro-hydro power plants are still controlled manually by humans when there is a change in the electrical load on the generator output. If there is a change in the electrical load, the generator output voltage will change, thus affecting the rotation of the turbine being used. In this case, humans are needed to manually regulate the flow of water entering the turbine to maintain the stability of the generator output voltage by controlling the sluice gate. The water discharge entering the screw turbine will rotate the generator through a belt/gearbox pulley transmission, thus producing an electrical voltage at the generator output. To maintain the stability of the generator output voltage, it is necessary to control the water discharge entering the screw turbine. The expected goal of this research is to design a control system for a screw turbine type microhydro power plant to stabilize the generator output voltage and monitor the output of a screw turbine type generator using a SCADA (Supervisory Control, and Data Aquisition) system. The method used is the research and development method, namely the system design stage based on secondary data that has been collected, where the system design includes hardware design and software design, followed by making hardware such as control panels and devices. Software, which includes display design and leader diagrams and testing, is carried out by testing the system on software, hardware, and overall system testing. From the results of the discussion and analysis, the screw turbine type microhydro power plant control design system was created, a load control system consisting of 6 groups and sluice gate opening control that uses an ultrasonic sensor to determine the water level. With the results of controlling the sluice gate at a door opening of 30 mm, the generator voltage is 18.42 Volts DC, DC current is 0.0 Ampere at a load of 0 watts, when the load is 30 watts the generator voltage decreases by 18.40 volts, current is 1.37 Ampere. Through the on-line monitoring system, electrical parameters are obtained which are displayed on the SCADA system by looking in real-time at the history of DC voltage and DC current, DC power, and DC energy generated by the screw turbine-type DC generator. The voltage read is 18. 57 volts, current 1.37 Amperes, DC electrical power is 25.4 watts with a DC light load of 30 watts.

Evaluating Diatomaceous Earth for Long-Term Use in Hydrogen Storage.

Efficient hydrogen storage is essential for its use as a sustainable energy carrier. Diatomaceous earth, a high-surface-area siliceous geomaterial, shows potential as a physisorption material for hydrogen storage. This study analyzes diatomaceous earth's long-term characteristics when subjected to high-pressure hydrogen injection. The diatomaceous earth was subjected to a hydrogen pressure of 1200 psi for a period of 80 days at room temperature. Neither notable morphological or mineralogical changes were observed. Nevertheless, there was a slight reduction in fine particles and a slight increase in larger particles. The Brunauer-Emmett-Teller (BET) surface area decreased slightly with a significant decrease in pore width. However, the hydrogen adsorption at 77 K temperature was increased significantly (45.5%) after the hydrogen storage test. Moreover, there was a delayed release of molecular water as the temperature increased. These changes suggest that a condensation reaction has occurred involving some of the opal-A silanol groups (Si-O-H), producing molecular water. Bonding through siloxane bridges (Si-O-Si) results in a significant decrease in pore width and increased hydrophobicity (i.e., the interaction between diatomaceous surface and H2 was increased), thereby enhancing hydrogen adsorption capacity. These findings indicate that diatomaceous earth holds promise as a material for hydrogen storage, with the potential for its hydrogen adsorption capacity to improve over time.

Modelling of a Lake Outburst as a Result of the Development of Piping

The retreat of mountain glaciers inevitably leads to an increase in the number of outburst moraine lakes. One of the possible mechanisms of moraine dam outburst along with overflow over the crest is the formation of a filtration channel in the body of the moraine dam (piping). An algorithm for calculating the outburst flood hydrograph, describing the development of a filtration channel in the body of a moraine dam and the subsequent formation of water overflow when the soil above the channel collapses, is proposed in this paper. Verification of proposed methodology was carried out on the basis of experimental data and published data of real outbursts. Satisfactory results verifying this methodology made it possible to use the proposed methodology for the calculation of the hydrograph of the outburst of Lake Bashkara in the Elbrus region, which occurred on 1 September 2017. It is shown that the simulation results are quantitatively comparable with the estimates obtained from field data: the time of water discharge through the channel was 16 min, the period of the outburst wave passage was 40 min, and the maximum discharge was 636 m3/s. Thus, the possibility of applying the proposed methodology for calculating the destruction of natural moraine dams has been demonstrated.

Estimation of Groundwater River Availability in Leang Lonrong Cave Using ARIMA Model and Econophysics Valuation Approach

This quantitative descriptive study uses the ARIMA model approach to predict groundwater river water availability. It assesses its valuation with an econophysics orientation in the Leang Lonrong Cave area of TN Bantimurung Bulusaraung. Secondary data from 2010-2023, including Water Discharge and Water Level data from the River Basin Center of Pompengan Jeneberang (BBWS) and primary data on the Valuation of Willingness to Pay, were utilized. The analysis reveals that water discharge predictions (2024-2030) in the Gua Leang Lonrong area indicate consistent annual water availability, with the highest discharge projected in December 2030 (5.08 m3/s) and the lowest in September 2024 (1.12 m3/s). Valuation of utilizing Leang Lonrong River water through willingness to pay showed residents willing to pay Rp 42,142.85/month for clean water management. At the same time, visitors are willing to contribute Rp 21,596.77/visit to enhance water quality management. Elasticity analysis modeling water discharge with willingness to pay suggests a relatively elastic relationship, with a minor impact, indicating unresponsiveness to changes in water discharge percentages. Statistical and economic methods were employed to analyze daily water discharge patterns and evaluate residents' willingness to pay for underground river water utilization. The ARIMA model (0,1,1) forecasted future water discharge patterns with a mean absolute percentage error (MAPE) of 33.7%. The study surveyed 62 respondents, finding an average willingness to pay approximately IDR 21,596.77 per visit to maintain Leang Lonrong River water quality management.

Multifunctional double cold source system using temperature-sensitive hydrogel for cooling extravehicular spacesuits

The development of future space missions aimed at extended distances has challenged the thermal protection performance of extravehicular spacesuits. The use of more efficient and lightweight cooling systems in spacesuits can reduce costs and promote the advancement of human spaceflight. This study applies the temperature-sensitive hydrogel to the cooling system of the spacesuit, which combined with a water sublimator constitutes a double cooling source that dissipates heat simultaneously. As shown by modeling and simulation, the novel system effectively dissipates heat, with an 11.42% increase in total heat dissipation over the conventional method. Furthermore, the hydrogel can store water, and the water released during heat dissipation is provided to the sublimator for backup, reducing water consumption by 31.2% and lowering consumable demand. We defined the sublimation water release heat dissipation ratio, and it ranges from 1.5 to 3.5 in different operating modes, with the water sublimator serving as the primary cooling source. The research results suggest that the novel double cold source system can deploy heat dissipation capacity according to heat load distribution and flexibly meet the requirements of various tasks. The double cold source system is a highly efficient thermal management system that provides a novel approach to optimizing spacesuits.

Ionic liquid catalyzed low-temperature hydrothermal carbonization of sewage sludge to produce hydrochar with low heavy metal content and positive energy recovery

An ionic liquid (IL, [DMAPA]HSO4) was prepared to facilitate the removal of heavy metals by hydrothermal carbonization (HTC) in sewage sludge (SS) and to obtain a positive energy recovery (ER, (Energyoutput/Energyinput − 1) > 0). The results found that the removal efficiencies of the Fe, Mn, Zn, Co, and Cd from SS exceeded 75 % with positive ER (6 %) at 20 wt% IL dosage (IL:SS). IL promoted the HTC reactions of proteins and polysaccharides to produce fixed carbon and small molecule polymers. The process mainly relies on IL to catalyze the dehydration and graphitization of SS and to destroy the heavy metal binding sites such as carboxyl and hydroxyl groups. Additionally, IL aids in constructing the macropore structures in hydrochar, thereby facilitating the release of heavy metals and water during the HTC process. This discovery holds promise for removing heavy metals from SS by one-pot HTC processes with positive energy recovery.

LiCl in situ decorated metal-organic framework (MOF)-derived porous carbon for efficient solar-driven atmospheric water harvesting.

Solar-powered sorption-based atmospheric water harvesting (AWH) technology is a promising solution to the freshwater scarcity in arid regions. Existing adsorbent materials still face challenges in aspects such as cycling stability and adsorption kinetics and require further development. Herein, we presented a strategy for the in situ fabrication of high-performance adsorbents, lithium chloride (LiCl)-decorated metal-organic framework (MOF)-derived porous carbon sorbents (PCl), via high-temperature pyrolysis and hydrogen chloride (HCl) vapor treatment. The sorbents display high adsorption capacity across a wide range of humidity water adsorption capacities in a wide humidity range with the maximum adsorption capacity of 7.87 g g-1, and rapid response to the solar-driven process and excellent cyclic stability. The LiCl nanocrystals in PCl can be utilized efficiently and decorated within the porous framework stably, and demonstrate water adsorption at 20%, 40%, 60% and 80% RH, of 1.34, 1.69, 2.56 and 4.23 gH2O·gLiCl-1, respectively, and significantly higher water uptake and release rates than bulk LiCl. This may provide new guides for designing efficient solar-driven AWH.

Using biophysical modelling and marine connectivity to assess the risk of natural dispersal of non-indigenous species to comply with the Ballast Water Management Convention

AbstractThe introduction of Marine Non-Indigenous Species (NIS) poses a significant threat to global marine biodiversity and ecosystems. To mitigate this risk, the Ballast Water Management Convention (BWMC) was adopted by the UN International Maritime Organisation (IMO), setting strict criteria for discharges of ballast water. However, the BWMC permits exemptions for shipping routes operating within a geographical area, known as a Same-Risk-Area (SRA). An SRA can be established in areas where a risk assessment (RA) can conclude that the spread of NIS via ballast water is low relative to the predicted natural dispersal. Despite the BWMC's requirement for RAs to be based on modelling of the natural dispersal of NIS, no standard procedures have been established. This paper presents a methodology utilizing biophysical modelling and marine connectivity analyses to conduct SRA RA and delineation. Focusing on the Kattegat and Øresund connecting the North Sea and Baltic Sea, we examine two SRA candidates spanning Danish and Swedish waters. We provide an example on how to conduct an RA including an RA summary, and addressing findings, challenges, and prospects. Our study aims to advance the development and adoption of consistent, transparent, and scientifically robust SRA assessments for effective ballast water management.

Flow over thin-plate weirs with a triangular notch – influence of the relative width of approach channel with a rectangular cross-section

Abstract The article deals with the determination of the influence of the relative width of an approach channel with a rectangular cross-section on the discharge of clean water flowing over thin-plated weirs with a triangular notch and zero height of the weir above the bottom of the approach channel. To evaluate the influence, the Kindsvater-Shen equation was modified by introducing the basic effective discharge coefficient and the coefficient of the relative width of the approach channel. The coefficient of the relative width of the approach channel was determined based on the evaluation of data from three extensive experimental research investigations. It is valid for the entire possible range of relative widths of the approach channel and for the range of notch angles from 5.25° to 91.17°. The relative error of discharge determination is approximately up to ±2% over the entire range of discharges used in the conducted experimental research. The evaluation made it possible to determine the boundary distinguishing the partially contracted weirs from the fully contracted weirs in terms of impact on discharge.