Pump Location Research Articles

Ultrafast Modulation of a Nonlocal Semiconductor Metasurface under Spatially Selective Optical Pumping.

Time-varying optical metasurfaces have attracted significant research attention for their ability to dynamically modulate the spectral characteristics of light and achieve effects not possible in static systems. Nonlocal metasurfaces, with their spatially extended resonant modes, have the potential to further expand these capabilities by enabling spatially selective modulation. Here, we experimentally explore the application of spatially structured femtosecond laser pumping to modulate a leaky guided mode in a semiconductor metasurface. Using angle-resolved transient transmission spectroscopy, we study the dynamic response of the system across a range of wavelengths and angles of incidence, observing frequency and momentum conversion. When the pumping location is varied, this technique allows for reconstructing the temporal dynamics of the probe pulse propagating in the metasurface mode. Our results not only demonstrate a versatile toolkit for spatiotemporal light control but also provide fundamental insight into the excitation of spatially extended modes in nonlocal metasurfaces.

A Study the Water Quality Measuring Equipment with Automatic Sensor System

This paper studied the water quality in Dong Khoai Village, Xaythani District, Vientiane Capital, which is the primary water pumping location for agriculture. The area has a population of over 1735 citizens and cover more than 450 hectares. Common issue found in Markhiaw river. Stream is its toxicity to certain rice field, causing it inability to grow rice despite using fertilizer. Furthermore, this stream gives dissatisfaction odor, negatively affects people who get into the water for fishing and occasionally found death fish in the areas. In order to assess the water quality and disseminate the results to the public. Therefore, this study aims to investigate the creating of an automated sensor system for high precision water quality monitoring in the water. Four sensors; pH (hydrogen potential), EC (electro conductivity), TDS (total dissolved solid), and temperature are used in this procedure. The sensor system was tested, and build a small station uses solar energy and saves information into the SD card and available online by Blynk, and compare the test results with national environmental standards. The research revealed that, in comparison to the standard instrument S5 pro parameter, the measuring stations for the water quality values of all four sensors are accuracy value of 92.91% to 99.34%. Based on the information gathered over the course of two months, from February 13 and March 18, the pH value will be low, at 5. The pH value is high, at 11, between 13, 17 and 18 February 2024. These numbers are considered to be in the standard ranks. Regarding the dissolved solids in the water vary from 3 to 100 mg/L, and the electrical conductivity is between 100 and 180 µS/cm. They are also fall upon the National Environmental Standard. The Temperature value is high, at 40.81 ºC on 4 February 2024 and from 02 March 2024, the Temperature value will be low, at 24.4ºC.

Advancing noise reduction strategies for domestic air-source heat pumps

With the increasing adoption of heat pump technology in the energy sector, addressing noise emissions is crucial for public acceptance, regulatory compliance, and sustainable urban planning. Air-Source Heat Pump's noise emission, noise sources, reduction strategies, problematic frequency ranges, and noise transmission within buildings are considered. Various noise reduction strategies, including the strategic siting, enclosures, and vibration isolation techniques, are discussed. This study considered a scenario of heat pump noise emission which generated noise complaints. The heat pump noise source is investigated though 24 hour monitoring of far field acoustics in a suburban residence. A commercial implementation of ISO 9613 is used to predict the environmental noise impact. Results demonstrated that levels exceeded natural background by as much as 10-15 dB but that this could be mitigated through strategic placement of the heat pump. This study underscores the importance of implementing comprehensive noise control strategies for Air-Source Heat Pumps in urban areas to safeguard community well-being and ensure regulatory compliance. By integrating innovative noise reduction technologies and considering factors such as strategic location of Air-Source Heat Pump, installation practices, building design, and proper urban planning policies can enhance Air-Source Heat Pump's reliability while promoting a sustainable urban development.

Development and Field Test of Integrated Electronics Piezoelectric Accelerometer Based on Lead-Free Piezoelectric Ceramic for Centrifugal Pump Monitoring.

In this study, an Integrated Electronics Piezoelectric (IEPE)-type accelerometer based on an environmentally friendly lead-free piezoceramic was fabricated, and its field applicability was verified using a cooling pump owned by the Korea Atomic Energy Research Institute (KAERI). As an environmentally friendly piezoelectric material, 0.96(K,Na)NbO3-0.03(Bi,Na,K,Li)ZrO3-0.01BiScO3 (0.96KNN-0.03BNKLZ-0.01BS) piezoceramic with an optimized piezoelectric charge constant (d33) was introduced. It was manufactured in a ring shape using a solid-state reaction method for application to a compression mode accelerometer. The fabricated ceramic ring has a high piezoelectric constant d33 of ~373 pC/N and a Curie temperature TC of ~330 °C. It was found that the electrical and physical characteristics of the 0.96KNN-0.03BNKLZ-0.01BS piezoceramic were comparable to those of a Pb(Zr,Ti)O3 (PZT) ring ceramic. As a result of a vibration test of the IEPE accelerometer fabricated using the lead-free piezoelectric ceramic, the resonant frequency fr = 20.0 kHz and voltage sensitivity Sv = 101.1 mV/g were confirmed. The fabricated IEPE accelerometer sensor showed an excellent performance equivalent to or superior to that of a commercial IEPE accelerometer sensor based on PZT for general industrial use. A field test was carried out to verify the applicability of the fabricated sensor in an actual industrial environment. The test was conducted by simultaneously installing the developed sensor and a commercial PZT-based sensor in the ball bearing housing location of a centrifugal pump. The centrifugal pump was operated at 1180 RPM, and the generated vibration signals were collected and analyzed. The test results confirmed that the developed eco-friendly lead-free sensor has comparable vibration measurement capability to that of commercial PZT-based sensors.

Peritoneal baclofen pump migration: a rare complication of subfascial placement. Illustrative cases.

The intrathecal baclofen pump is an effective treatment option for patients with severe spasticity. In children, subfascial pump placement is often preferred given concerns for infection and wound healing. However, this approach is not without risk, and rare complications, such as peritoneal pump migration, can occur. The authors describe three pediatric cases of peritoneal pump migration at their institution over the past 14 years (3/545, 0.5%). All three patients had low body weight (below the 39th percentile), and two had scoliosis requiring surgery. All pumps had been placed using the subfascial technique. The first case occurred 6 months postplacement, and the pump was not replaced. Cases 2 and 3 occurred at 2 and 3 years postplacement, respectively, and both pumps were replaced. The authors conclude that peritoneal pump migration, although uncommon, can occur in patients with subfascial pump placement, and providers should have a low threshold of suspicion for repeat imaging prior to refilling if the pump's location has migrated. Potential contributing factors to pump migration include a patient's small size, a larger pump size (40-mL pump), and scoliosis. All these factors should be considered during pump placement, and surgeons can consider using a 20-ml pump for smaller patients. https://thejns.org/doi/abs/10.3171/CASE24290.

Modulation optimization when using a splitter pump after the first dimension in comprehensive two- dimensional liquid chromatography

The rapid growth in the use of two dimensional liquid chromatography (2D-LC) applied to the analysis of moderately to highly complex mixtures, has been fueled by continuous improvements in performance and robustness of the instrument components, as well as the ease-of-use of software necessary for controlling the 2D-LC instrument hardware, and analysis of the large data files that result from this type of work.This work has focused on the evaluation of the performance of an online full comprehensive mode (LC×LC), when an active modulation is implemented using a flow splitter pump placed after the 1D effluent. Two different types of splitting pumps were evaluated: a binary ultra-high pressure liquid chromatography (UHPLC) pump and a high precision syringe pump. We analyzed the performance (reproducibility in peak area and retention times and the 2D peak dispersion) as a function of the location of the active pump Before or After the modulation valve, and the influence of connecting tubes (based on internal diameter and length) necessary between the interface, waste, and the splitting pump. The effect on the flow direction on the filling and flushing of the injection loops at the modulation valve was also analyzed for each pump.In this study, we demonstrate that flow-splitting LCxLC assembly can be performed using either a UHPLC binary pump or a simple syringe pump. Flow splitting after the first dimension is a straightforward strategy to: (i) independently select the 1D column and flow rates with respect to the second dimension; (ii) consciously dilute the eluate according to the solvent characteristics of the second dimension, thereby avoiding 2D peak distortions; and (iii) adapt the injected amount to the second column according to the relative concentration of the components in a complex sample. However, careful consideration of the system setup is necessary. It is demonstrated how experimental results can be significantly affected in terms of peak broadening and reproducibility if optimization of the interface is not taken into account.In addition, under the optimized conditions, the reproducibility in peak area and dispersion in the 2D dimension were evaluated as a function of the amount of sample transferred in terms of percentage of filled loop.

Upwelling processes variability and water circulation along the northern margin of the Gulf of Cadiz

The present study investigates the contributions of upwelling mechanisms (coastal upwelling from boundary divergence and Ekman pumping from spatially variable wind) at the northern margin of the Gulf of Cadiz (NMGoC) based on high-resolution wind. The effects of the spatiotemporal upwelling mechanisms variability are then explored using current observations along with sea surface temperature and sea level anomaly. Upwelling favourable conditions occur throughout the year along the NMGoC, with the strongest intensity near Cape São Vicente due to a persistent positive wind stress curl. In winter, the surface water divergence is restricted to the coastal boundary due to strong coastal upwelling events that result in a cross-shore sea-level gradient close to the coast. Towards the summer, the gradient increases and extends further offshore (over the slope) at the western region due to the intensification of the Ekman pumping. Therefore, the seasonal and spatial variability of coastal upwelling and Ekman pumping contributes significantly to the offshore position of the geostrophic Gulf of Cadiz Current over the western shelf slope. Furthermore, a permanent sea level depression corresponds to the location of the strongest Ekman pumping, near Cape São Vicente. The dynamic adjustment of this feature may drive the cyclonic cell and alongshore poleward currents often observed in the area.

PLANNING FOR THE DEVELOPMENT OF A DRINKING WATER DISTRIBUTION SYSTEM NETWORK IN SUNGAI PINYUH

The increasing water demand due to population growth and territorial expansion has significantly outpaced the natural water supply in Sungai Pinyuh, Kalimantan Barat. This sub-district, part of the Mempawah Regency, faces challenges such as insufficient access to clean water, deteriorating pipe infrastructure, and environmental pollution affecting water quality. To address these issues, a study has been undertaken to plan a comprehensive development of the drinking water distribution system in Sungai Pinyuh, guided by the Regional Regulation of Mempawah Regency No. 3 of 2014. The planning utilizes EPANET software, a tool developed by the U.S. Environmental Protection Agency (EPA), which allows for the simulation of dynamic conditions in the water distribution system. EPANET helps create detailed maps of the pipe network, determine pump and reservoir locations, and specify pipe characteristics. The software’s ability to simulate various scenarios, such as changes in demand or disruptions, is crucial for ensuring a reliable water supply. The analysis incorporates primary data from field observations and secondary data from population statistics and existing water supply documents. The proposed distribution system will employ HDPE pipes of various diameters and a pump with a capacity of 200 L/s and a head of 5 meters. Simulation results indicate that the system's velocity, ranging from 0.3 to 0.72 m/s, and other parameters, such as head loss and pressure, are within acceptable limits. Additionally, reservoir capacity planning is based on the maximum daily water demand, with a calculated capacity of approximately 3,347.839 m³ to ensure adequate supply. This study provides a strategic framework for improving the drinking water distribution system, addressing current deficiencies, and preparing for future needs.

The role of divertor pumping combined with full drifts in particle exhaust and divertor plasma

The effect of drifts combined with pumping on particle exhaust is assessed using the SOLPS-ITER code package, considering full drifts. Both drift and pumping speed S can affect particle exhaust. Drifts change the neutral density by influencing plasma flow and the resulting particle recycling. This leads to the accumulation of neutral particles either far away or close to the pump opening location. The particle exhaust is enhanced as S rises. When the pump opening is positioned at the common flux region (CFR) of the outer divertor (referred to as Pump CFR/OD), particle exhaust is suppressed by drifts in forward Bt , while it is enhanced by drifts in reversed Bt , with fixed S. On the other hand, when the pump is situated in the private flux region (PFR) of the OD (referred to as Pump PFR/OD), particle exhaust is enhanced by drifts in both reversed and forward Bt compared to the case without drifts. Moreover, the effective pumping in reversed Bt is stronger than in forward Bt . In the same Bt direction, Pump PFR/OD has a higher effective pumping than Pump CFR/OD. Increased S results in higher particle exhaust in all Bt direction and pump location cases. The plasma detachment is affected by drift, S and pump opening location, respectively. For the specified Bt direction and pump opening location case, higher S suppresses plasma detachment. For identical particle exhaust rates, stronger pumping capacity can promote plasma detachment. Therefore, Pump PFR/OD can more easily achieve OD detachment than Pump CFR/OD in the same Bt direction. Overall, placing the pump at the PFR side of the OD while running in reversed Bt is the best option from the divertor particle exhaust and plasma detachment point of view.

Hydrogeologic Framework Model‐Based Numerical Simulation of Groundwater Flow and Salt Transport and Analytic Hierarchy Process‐Based Multi‐Criteria Evaluation of Optimal Pumping Location and Rate for Mitigation of Seawater Intrusion in a Complex Coastal Aquifer System

AbstractA series of hydrogeologic framework model (HFM)‐based steady‐ and transient‐state numerical simulations is performed first using a coupled subsurface flow‐transport numerical model to analyze groundwater flow and salt transport in an actual three‐dimensional complex coastal aquifer system before and during groundwater pumping. A series of analytic hierarchy process (AHP)‐based multi‐criteria evaluations is then performed applying a multi‐criteria decision‐making approach to determine optimal pumping location and rate for a new pumping well in the complex coastal aquifer system during groundwater pumping. The complex coastal aquifer system is composed of six anisotropic fractured porous geologic media (five rock formations and one fault) and three isotropic porous geologic media (three soil formations) and shows high geometric irregularity and significant heterogeneity and anisotropy of the nine geologic media. Results of the steady‐state numerical simulations show successful model calibration with 26 measured groundwater levels and two observed seawater intrusion front lines. The latter two are determined by spatial interpolation and extrapolation of electrical conductivity logging data and electrical resistivity survey data, respectively. Based on the status and prospect of necessary water uses and available groundwater resources, the field observations of groundwater and seawater intrusion, and the analyses of the steady‐state numerical simulation after the model calibration, six candidate pumping locations are selected for the new pumping well. In addition, from six preliminary individual transient‐state numerical simulations, maximum pumping rates at the six candidate pumping locations are calculated first, and a set of six incremental candidate pumping rates is then assigned at each of the six candidate pumping locations. Results of the transients‐state numerical simulations show that groundwater flow and salt transport are spatially and temporally changed, and seawater intrusion is further intensified by groundwater pumping. In addition, the magnitudes of such spatial and temporal changes and intensification are significantly different depending on the candidate pumping locations and rates. Results of the steady‐ and transient‐state numerical simulations also show that both complexity (geometric irregularity, heterogeneity, and anisotropy including the fault) and topography have significant effects on the spatial distributions and temporal changes of groundwater flow and salt transport in the coastal aquifer system before and during groundwater pumping. In addition, results of statistical estimations of the mesh Peclet and Courant numbers confirm acceptabilities of minimizing numerical dispersion in the steady‐ and transient‐state numerical simulations. Based on the analyses of the transient‐state numerical simulations, eight multiple criteria are chosen to judge, prioritize, and rank the six candidate pumping locations and six candidate pumping rates for optimal pumping. Results of the multi‐criteria evaluations determine the optimal pumping location and rate for the new pumping well among the six candidate pumping locations and six candidate pumping rates. In addition, results of consistency checks confirm consistencies of judgments in the multi‐criteria evaluations.

Improving the Water Distribution System to Support a Future Water Demand in the Western area of Chao Phaya River

Bangkok and its vicinities’ city areas are expanding and are requiring the higher water supply from the Maha Sawat and Bang Bua Thong service areas of the Metropolitan Waterworks Authority. As a result, the existing water network system’s water pressure may decrease and be inadequate to supply the water to the service areas. The study utilizes the water pipe network model, EPANET, of the Maha Sawat and Bang Bua Thong service areas that has been calibrated previously. The model was satisfyingly calibrated and accepted by balancing the water volume and pressure level. In this research, the model is used to evaluate the existing pipe network system of the study area under the future water demand condition in the next five years. Then, the model is used to define optimal location of a new pumping station that needs to increase the water distribution system efficiency and its stability. Five proposed location that need to increase the water distribution system are assumed to use the same pumping pattern and supply pressure. Each pumping station supplies a pressure head at least eight meters and use the water pressure multipliers from the Phet Kasem pumping station for each period. By using the average water pressure and the contour pressure of water distribution area as an indicator comparing the five pumping locations individually, the result showed that the best location of the new pumping station is located on Highway No.345 km.5+735.00.

A construction strategy of Kriging surrogate model based on Rosenblatt transformation of associated random variables and its application in groundwater remediation

When using simulation-optimization models for optimizing the design of groundwater pumping-treatment plans for pollution, building a surrogate model for the numerical simulation model has become an effective means of overcoming the computational load of such models. However, previous studies often treated pumping time as a single optimization variable, leading to unnecessary excessive pumping. This paper considers the location, pumping rate, start time, and end time of each candidate pumping well as optimization variables, and proposes a Rosenblatt-transform-based optimal Latin hypercube sampling method for the associated random variables to ensure that the start time is less than or equal to the end time. This method is coupled with an adaptive sampling method based on batch local optimal solutions to construct a dynamic adaptive Kriging surrogate model for the numerical model, ensuring that the true value of the optimal remediation scheme is not lost. The results show that, at the final stage of remediation, the pollutant concentration in the 4 scenarios achieves comprehensive compliance. However, when considering the minimization of remediation costs as the evaluation criterion, the remediation scheme in scenario 1 (the pumping start and end times are independent optimization variables for all candidate pumping wells) is optimal. In the optimization design of groundwater pumping-treatment plans, the pumping wells should be arranged in the midstream and downstream regions of the contaminant plume and parallel to the regional flow direction. This paper provides a method reference for the construction and adaptive updating of surrogate models involving associated random variables, as well as guidance for the dynamic optimization of groundwater pumping and treatment at contaminated sites.

Impact of connected conduit on pumping-induced seawater intrusion in a coastal karst aquifer

IntroductionCoastal karst aquifers face the risk of seawater intrusion due to groundwater development. Based on the conceptualization of Woodville Karst Plain (WKP), this study investigates the effect of karst conduit and pumping conditions on the aquifer vulnerability and pumping security.MethodsAccording to the purposes of this study, two cases are considered: one with conduit and one without. Salinization levels are compared between two cases, considering pumping rates ranging from 50 to 200 m3/day and various pumping locations throughout the on-shore region.ResultsThe results reveal that the aquifer with conduit is more susceptible to seawater intrusion at low pumping rates, whereas both scenarios experience significant salinization at high pumping rates. Specifically, in the non-conduit case, contamination is most prevalent when wells are located in the middle of the aquifer, while in the conduit case, pumping from inland areas poses high vulnerability. Moreover, conduit case and non-conduit case display different regions for pumping clean water. At low pumping rates, both cases show saline water being pumped from wells near the shore, and clean water is obtained from inland wells. At high pumping rates, the non-conduit case allows for clean water extraction from wells situated further inland, while in the conduit case, no wells within the entire aquifer are deemed safe.DiscussionThe analysis and findings of this study offer valuable insights for the management of groundwater in coastal karst aquifers, encompassing vulnerability assessment, selection of pumping locations, and determination of pumping rates.

A novel framework for spatiotemporal groundwater pumping process estimation based on data-driven approaches

Understanding the spatial and temporal distribution of pumping activities is crucial for effective water resource management. However, obtaining accurate pumping records is often challenging, particularly in areas without efficient groundwater withdrawal permit systems. In this study, we propose a novel approach for identifying pumping activities and estimating their associated pumping rates across space and time. Our data-driven approach integrates empirical orthogonal function (EOF) and Hilbert-Huang transform (HHT) analyses on first-differenced head data to extract high-frequency head variations that are closely related to pumping activities. The identified pumping-associated head variations are used to estimate the on-and-off times of local pumping stations and their associated pumping-rate time series. We test our approach using a hypothetical aquifer with designed pumping and real precipitation time series. Our results show that the EOF analysis is able to distinguish pumping locations where distinct temporal head variabilities are present. HHT analysis is then able to effectively remove noise from the EOF-identified pumping-associated head variations. Compared to the designed pumping data, our results demonstrate that our proposed method is able to produce accurate pumping estimates in terms of both spatial and temporal distribution and total amounts. While our approach does have limitations, such as delayed and boundary effects, our results suggest that it can be an effective tool for pumping estimation in areas with relatively abundant head observations across space and time, which is a common scenario in Taiwan.

Susceptibility Modeling for Potential Fire Risk Zone in Semi-Urban Area

Fires inflict major losses in global forest resources as well as human lives and property. Forest fires and their tendencies have increased in recent years in Nepal that, necessity for adequate management actions. The fire risk zone is identified with the origin of the ignitions and the pattern of their occurrence, as well as by shared environmental variables that translate into the same risk potential. To reduce the detrimental impacts of fire, several strategies for preventing and combating fires have been implemented based on identified potential fire risk zone. The work is carried out in Shambhunath Municipality, Saptari. In this study, spatial modeling with integration of MCE, fuzzy and AHP is applied for susceptibility assessment for identifying the potential fire risk zone. In fire risk assessment index map shows that 21.14 percent of municipality extent land occurred in the fire risk in which the distribution of the high risk occupied 0.01 percent, medium risk, 0.49 percent, low risk 20.64 percent and remaining 79 percent land free from fire risk. The high risk of potential fire zone were identified along the east west highway surrounding to the high voltage transmission route and petrol pump location. Likewise, potential high risk of forest fire also found in the dense forest area in elevation greater than 400m.

An improved sharp interface model for characterizing the transport and extraction of subsurface LNAPL

Multiphase extraction (MPE) is widely used as an in situ method for the remediation of groundwater contaminated by light non-aqueous liquid (LNAPL). For the purpose of achieving the best performance of MPE remediation, it is critical to accurately characterize the LNAPL transport processes above the groundwater table with an easy-to-use model. In this study, we developed an improved sharp interface model considering constant head at the well screen and shark-fin distribution of LNAPL saturation above groundwater table. The model was successfully validated using the test data of Lari et al. (2018). The results indicate, the LNAPL extraction rate is most sensitive to the properties of fluid and media. Also, this improved model was used to analyze the effects of technical parameters such as submersible position of oil pump and water extraction rate on remediation performance, we observed that in the case of a single-pump MPE, even after changing the hydraulic conductivity and porosity of the media, the optimized location of the submersible LNAPL pump is halfway inside the well. Similarly, in the case of dual-pump MPE, an increasing pump rate of water (Qw) promotes the LNAPL extraction rate, and an empirical relationship between the optimized LNAPL pump position (ms) varies with the Qw exhibiting a certain pattern. Overall, the improved sharp interface model better interprets the field MPE data compared to the interphase mass-transport model proposed by Lari et al. (2018). Therefore, the proposed model characterizes LANPL transport during LNAPL extraction better and can also be utilized to optimize the MPE more comprehensively.

KAJIAN PEMANFAATAN POMPA AIR BANTUAN PEMERINTAH UNTUK MENUNJANG IRIGASI PERTANIAN DI KABUPATEN

AbstactThis research was conducted to determine the feasibility of using pumps infulfilling water for plants so that the farming system. Support for groundwaterirrigation by using pumps for farming activities in Minahasa Regency. Based onthe description above, research will be carried out on "Studies on the use ofgovernment-assisted water pumps to support agricultural irrigation in MinahasaRegency". The results showed that the most water pump assistance was providedin 2018 in Tombariri District, and the least in 2020 in Langowan and KakasDistricts were all donated to farmer groups. The pump assistance provided by thegovernment to farmer groups is the TWP 150 type of water pump, in reality in thefield the types of water pumps provided by the government are all the same,namely the Tanikaya TWP 150 water pump type with gasoline. Interview dataobtained from farmer groups receiving water pump assistance indicated that thereare two sources of water at the pump location, namely rivers and springs. Theresults of a survey conducted showed that the pump placement locations of allthose distributed were not placed in a certain place or no one used pump houses,because their use was carried out on a rotating basis so that the pumps wereplaced according to the needs in the field. The results obtained were that the useof government-assisted water pumps was not optimized properly because most ofthe assistance was not used properly or was rarely used, with the reason thatrainfall was insufficient and there were also pumps provided by the governmentthat the pump components were not complete, there were also pumps that hadbeen provided. switch to another tool.Keywords : Water pump, irrigation, utilization

Numerical study on residual rate of fluidized solidified slurry in pumping for scour repair around monopile

A new scour countermeasure for monopile foundation using solidified slurry have been proposed recently. The fluidized solidified slurry is pumped to the seabed area around pile for scour protection or into the developed scour holes for scour repair as the fluidized material solidifies gradually. During this complex process with pumping and solidification, the flow and diffusion of solidified slurry can result in the material loss and deterioration. However, there is still not a comprehensive and reasonable analysis on the state of retention of the fluidized solidified slurry in this process. Thus, the effect of scour protection can't be evaluated effectively. The current work focuses on the residual rate of fluidized solidified slurry during the pumping operation, which is the ratio between volume of the solidified slurry remaining in the scour pit and that pumped into. A series of multiphase flow (the ambient seawater and the solidified slurry) numerical simulations using a computational fluid dynamics (CFD) approach were conducted to investigate the effects of pumping location, current velocity, pumping velocity and material property of solidified slurry on the residual rate of fluidized solidified slurry. It was found that the pumping location near and at the downstream of the monopile with a lower pumping pipe nozzle is optimal for a higher residual rate of fluidized solidified slurry. Solidified slurry with smaller slump flow value pumped at a lower current velocity and higher pumping velocity contributes to a higher residual rate. Based on a comprehensive parametric study, an empirical formula is established to calculate the final residual rate of the solidified slurry for theoretical reference and practical application. This work provides an important insight in understanding the residual rate of solidified slurry in application to scour protection of monopile.

Exploring the Optimal Location of Pumps as Turbines Within Branched Irrigation Networks by Global Optimization

AbstractIn this study a new procedure to address the optimization of the location and selection of pumps as turbines (PATs) within irrigation networks is presented in order to reduce network pressure and recover energy. The proposed procedure consists of two steps: in the first step the optimization of the location of devices is performed, then the optimal selection and regulation is investigated in the second step. Two new mixed integer non‐linear models have been developed and a global optimization solver has been employed to perform both optimization procedures. The procedure has been tested on a real irrigation network in Spain. The entire 2015 irrigation season has been used to properly model the water demand within the system. According to the results, the optimal solution consists of 5 PATs, installed in the middle region of the system. The investment cost has been estimated as 169,278 € with a payback period of almost 4.2 irrigation seasons. According to the solution, the effective amount of produced energy is equal to 289 MWh if the system is properly regulated and the pressure exceeding the minimum requirements is exploited to produce energy. Compared to other studies in literature focused on irrigated agriculture, the number of PATs is not fixed but rather it results from the maximization of the energy recovery and the minimization of capital costs, simultaneously. Moreover, the proposed procedure relies on a deterministic approach, achieving promising results in terms of accuracy.

Співставлення варіантів розташування теплових насосів для гарячого водопостачання від АЕС

Fuel consumption for heat supply makes up about a third of the total amount of fuel and energy resources consumed in the country, and this value is twice as large as the amount of fuel consumed for electricity production. This means that in order to solve the problems related to climate change, it is necessary to use nuclear power plants (NPP) more widely in the direction of heat supply. The way to reduce heating costs is to use cogeneration. As the experience of using combined heat plants shows, fuel savings due to the combined production of electric and thermal energy is 13 % of the fuel consumption for electricity production. In the future, heat supply from NPPs should expand. This saves energy resources and reduces the burden on the environment. The use of steam condensation heat in the condenser of the NPP turbine as a low-potential source for a heat pump (HP) is considered. In this case, thermal pollution from the NPP is reduced. Currently, taxes for thermal pollution from NPPs are not charged, but, considering that this is one of their disadvantages and the great attention of humanity to the preservation of the environment, such taxes may soon be introduced. The work considers two options for the location of heat pumps to provide hot water supply to the city of Varash from the Rivne NPP: 1. Location of a powerful HP directly next to the NPP and transportation of hot water to the city. 2. Transportation of circulating water, heated in the condenser, to the city to provide HPs located near consumers. The comparison of these options was carried out on the basis of reduced costs, which took into account the cost of HPs, heat losses during the transportation of hot water and the cost of electricity for pumping. When taking into account the cost of HPs, the well-known formula for the dependence of specific equipment costs depending on capacity was used. As a result of the comparison, it was determined that the first option has the advantage. In the structure of reduced costs, the main contribution is made by the cost of heat pumps.