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In pursuit of enhancing the conveying performance of the spiral axial flow gasliquid multiphase pump, a comprehensive exploration is conducted to unravel the underlying influence mechanism of impeller structural parameters on gas-liquid separation. This study employs the Box-Behnken design, constructing a sample space that encompasses crucial factors such as impeller hub parameters and blade inclination angle, utilizing Computational Fluid Dynamics software to perform numerical simulations of various models within the sample space. Researching the influence of impeller hub diameter ratio and blade inclination angle on the internal flow of a multiphase pump, aiming to determine high-performance parameters under high gas content conditions with the coupled effects of impeller hub diameter ratio and blade inclination angle. The results indicate that the performance improvement becomes more pronounced when the blade inclination angle (γ) is greater than 2°. For hub structure parameters, the relative size of hub inlet coefficient (kd1) and hub middle section coefficient (kd2) is measured using the diameter ratio (kr), where kr ranges from 0.94 to 1.02. After optimization, the impeller hub parameters are kd1 = 0.77, kd2 = 0.76, kr = 1.013, γ = 6.95. In comparison with the original model, when the Inlet Gas Volume Fraction is 60%, the gas phase aggregation (λ) at 0.1Span is reduced by 4.5%, the energy dissipation (σ) is decreased by 5.3%, and the efficiency and head coefficient are increased by 2.331% and 0.05, respectively. Therefore, this study has vital theoretical and technical significance for improving the reliability, stability and efficiency of deepwater oil and gas transportation. [ABSTRACT FROM AUTHOR]

The purpose of this in vitro study was to evaluate the impact of the vertical level of the stopcock connecting the infusion line to the central venous catheter on start-up fluid delivery in microinfusions. Start-up fluid delivery was measured under standardized conditions with the syringe outlet and liquid flow sensors positioned at heart level (0 cm) and exposed to a simulated CVP of 10 mmHg at a set flow rate of 1 ml/h. Flow and intraluminal pressures were measured with the infusion line connected to the stopcock primarily placed at vertical levels of 0 cm, + 30 cm and − 30 cm or primarily placed at 0 cm and secondarily, after connecting the infusion line, displaced to + 30 cm and − 30 cm. Start-up fluid delivery 10 s after opening the stopcock placed at zero level and after opening the stopcock primarily connected at zero level and secondary displaced to vertical levels of + 30 cm and – 30 cm were similar (− 10.52 [− 13.85 to − 7.19] µL; − 8.84 [− 12.34 to − 5.33] µL and − 11.19 [− 13.71 to − 8.67] µL (p = 0.469)). Fluid delivered at 360 s related to 65% (zero level), 71% (+ 30 cm) and 67% (− 30 cm) of calculated infusion volume (p = 0.395). Start-up fluid delivery with the stopcock primarily placed at + 30 cm and − 30 cm resulted in large anterograde and retrograde fluid volumes of 34.39 [33.43 to 35.34] µL and − 24.90 [− 27.79 to − 22.01] µL at 10 s, respectively (p < 0.0001). Fluid delivered with the stopcock primarily placed at + 30 cm and − 30 cm resulted in 140% and 35% of calculated volume at 360 s, respectively (p < 0.0001). Syringe infusion pumps should ideally be connected to the stopcock positioned at heart level in order to minimize the amounts of anterograde and retrograde fluid volumes after opening of the stopcock. [ABSTRACT FROM AUTHOR]

Fertigation technology plays a crucial role in the fertilizer utilization efficiency and sustainable development of modern agriculture. Among them, the piston-type fertilizer injection pump serves as the vital equipment for the uniform fertilizer injection in the large-scale irrigation systems. In this study, the numerical investigation and experimental validation were presented on the internal flow and external performance of the piston-type fertilizer injection pump during reciprocating motion. A three-dimensional numerical simulation model for the transient flow in the piston fertilizer injection pump was established based on the dynamic mesh and the RNG k-ε turbulence model. The gap between the dynamic mesh boundary and the static boundary was treated by thegap model with zero mass flux into the gap grid. The motion of the valve core in the flow field was analyzed by the six degrees of freedom (6DOF) solver. The external properties of the piston injection pump under different conditions were investigated, and the internal flow field characteristics of the pump under nominal condition were analyzed. The reliability of the numerical simulation model was verified by comparing the predicted flow rate with the experimental and theoretical data. It was found that the maximum relative error between the predicted and the experimental time-averaged flow rates was 3.58% for different strokes. The instantaneous flow rates were obtained from the numerical simulations and theoretical calculations. A high degree of consistency was demonstrated in both magnitude and trend, with the maximum relative error of 3.17%. The high velocity zone was concentrated in the flow channel of the outlet check valve, with the maximum velocity of 7.74 m/s, during the discharge phase of the pump. While a significantly increased pressure observed in the pump chamber with the maximum relative static pressure of 69.1 kPa. In the suction stage of the pump, the high flow velocity area was mainly concentrated in the inlet check valve channel. The maximum flow velocity of 8.05 m/s was found to increase the vacuum degree within the pump, resulting in the minimum relative static pressure of -79.8 kPa. In contrast to the discharge stage, the liquid in the suction process entered the pump cavity through the inlet valve, and then impinged on the wall of the pump chamber, indicating the complex mixing and turbulent structure within the pump cavity. There was a lag behavior at the initial stages of both the discharge and suction during the reciprocating motion of the piston. The formation of backflow was attributed to the delayed closure of the inlet and outlet valve core. A sudden change in the instantaneous flow rate of the fertilizer injection pump was also observed. The time of the sudden change was consistent with the time of valve core closure. The amplitude of the flow rate variations in the inlet and outlet valves at the sudden change point were equivalent. The timeaveraged flow rate of the fertigation piston pump showed a positive linear correlation with the ratio of piston stroke (k) and reciprocating frequency (f). The volume coefficient of the fertilizer injection pump decreased with the decrease of the piston stroke, but there was no significant change with the reciprocating frequency of the piston. Meanwhile, the measured volume coefficient of the variable frequency regulation differed by only 2.65% from the rated operating condition at the low flow rate (k=20% and f=10 Hz). In contrast, the volume coefficient of the variable stroke regulation differed by as much as 13.94%. Therefore, the frequency modulation control can be expected to more accurately regulate the flow rate of the piston injection pump. It is an optimal strategy for regulating the fertilizer injection in fertigation systems. The findings can provide a strong reference to optimize the fertigation piston injection pump. [ABSTRACT FROM AUTHOR]

Chinese High Magnetic Field Laboratory (CHMFL) will build a resistive magnet with steady magnetic field strength of 42 Tesla which will set a new record for a single resistive magnet. As one of the important auxiliary systems, the cooling water system needs to be fully upgraded to meet the higher cooling requirements of the magnet and the power system. In this paper, the reconstruction scheme of cooling water system is introduced firstly, then the parameters selection of the chilled water pumps and high-pressure pure water pumps are emphatically analyzed. The data fitting method and the applied fluid technology software ATF Fathom were used to analyze and check the selection of chilled water pump. After these pumps are in place, the effectiveness of the above analysis scheme has been verified through testing, which can provide a reference for the reconstruction of pumps in other systems. For the high-pressure pure water pump, the solution focuses on improving the overall cooling capacity of the pump group and also improving the system stability. Based on the large-circulation-flow magnet of CHMFL, tests were conducted on the parallel operation capability of the new and old pumps, and the system characteristic curve and pump performance curve are analyzed and researched. The result shows that the pump parameters selection is reasonable and the magnet cooling circulation capacity is effectively improved. [ABSTRACT FROM AUTHOR]

The flow field structure within the clearances of turbomachinery is complex and diverse, exhibiting high-dimensional nonlinearity. How to accurately extract the main structures that affect the internal flow within the turbine from the complex clearance flow has always been a key issue. To explore the impact of the dynamic structure of the clearance flow on the mainstream region in a centrifugal pump, this study combines the dynamic mode decomposition (DMD) method to conduct a thorough analysis of the velocity and pressure pulsation frequencies in the multi-physics fields within the clearance. The study has identified the main characteristic structures under different physical conditions in the clearance and has established the relationship between the characteristic structure frequencies in different physical fields and the impeller frequency. The research indicates that the internal flow within the clearance affects the occurrence of vortices in the volute. Under design conditions, the velocity field within the clearance is primarily influenced by high-order harmonic frequencies of the impeller, and the pressure field is mainly affected by low-order harmonic frequencies of the impeller. This reflects the crucial influence of impeller frequency and inlet flow on the coherent structures within the clearance flow. The research results offer new insights and methods for analyzing complex internal flows in large turbomachinery. [ABSTRACT FROM AUTHOR]

The continuity of a production process is supported by the availability of good assets. One of the efforts to support asset availability is through asset maintenance. One of the important assets in the industry is the pump. To detect anomalous conditions in the pump, the sound of the engine can be used. However, noisy environmental conditions can change the characteristics of the sound produced. This can have an impact on errors in identifying the condition of the machine. In this study, Mel Frequency Cepstral Coefficients (MFCC) is used, because the characteristics of MFCC are very attached to the sound signal and are appropriate for sound signals in the case of this noisy environment where the signal tends to be non-stationary. Support Vector Machine will be used as a method that maps input (machine features) and output (machine condition). In this study, a comparison of the use of combined features of time and frequency domains with time-frequency features (MFCC) will be carried out. Improved performance is obtained when the time-frequency domain acoustic feature in the form of MFCC is used with an average accuracy reaching 99.88% on the Medium Gaussian SVM model.

In swash plate type axial piston pumps, slipper/swash plate sliding surfaces is subject to high fluctuating load. Therefore, the slippers are required to provide stable operation and reduce losses due to sliding. The behavior of the slipper fluctuates in a complex manner due to changes in the hydraulic pressure in the cylinder and inertial forces caused by the reciprocating motion of the piston. However, the time variation of the oil film thickness distribution of the slipper has not been measured. Furthermore, there are no measurements of the movement of the spherical joint connecting the slipper and piston, which affects the slipper behavior. In this study, the visualized sliding test rig with a sapphire glass swash plate was developed. The oil film thickness distribution of the slipper and the rotation of the slipper and the piston were measured continuously during one rotation of the pump.

The design factor of surge tank installation is a practical issue in the management of pressurized pipeline systems. To determine the general criteria for surge tank design in pipeline systems, dimensionless governing equations for unsteady flow and their solutions were developed for two widely used pipeline systems equipped with surge tanks. One is the reservoir pipeline surge tank valve and the other is the pipeline system with a pumping station and check valve protected by the surge tank. Two distinct time-domain responses, point- and line-integrated pressure, can be used as objective functions to optimize the surge tank area. The developed formulations were integrated into a metaheuristic engine, particle swarm optimization, to explore a general solution for a wide range of dimensionless resistances that comprehensively address various flow features into one dimensionless parameter. Depending on the dimensionless location of the surge tank, the optimum dimensionless surge tank areas were delineated for a range of dimensionless resistances for the two pipeline systems with and without a pumping station protected by a surge tank. HIGHLIGHTS Dimensionless solutions for pressure response were derived for pipeline systems with surge tanks.; The dimensionless resistance represents flow rate, friction, diameter, length and wave speed.; Both point- and line-integrated pressures were used as objective functions.; The frequency domain models were integrated into particle swarm optimization.; Dimensionless surge tank areas were delineated for dimensionless resistances.;

Abstract This article describes a method for determining the geometric working volume of satellite positive displacement machines (pump and motor). The working mechanism of these machines is satellite mechanism consisting of two non-circular gears (rotor and curvature) and circular gears (satellites). Two variants of the satellite mechanism are presented. In the first mechanism, the rolling line of the rotor is a sinusoid "wrapped" around a circle. In the second mechanism, the rolling line of the rotor is a double sinusoid "wrapped" around a circle. A method for calculating the area of the working chamber as a function of the rotor rotation angle is presented, based on mathematical formulae of the rotor, the curvature and the satellite rolling lines. It has been shown that the second variant of the satellite mechanism is advantageously characterised by a larger difference between the maximum area of the working chamber and the minimum area of this chamber. New mathematical formulas have been proposed to calculate the area of the working chamber for any angle of rotation of the shaft (rotor) based on the maximum and minimum values of the area of this chamber. It was thus confirmed that the geometric working volume depends on the maximum and minimum area of a working chamber and on the height of the satellite mechanism. The analyses of the area of the working chamber were carried out both for the mechanism without gears (the area delimited by the rolling lines of the elements of the mechanism) and for the real mechanism with gears. Differences in the values of these fields were also detected.

The capability to record data in passive, image-based wearable sensors can simplify data readouts and eliminate the requirement for the integration of electronic components on the skin. Here, we developed a skin-strain-actuated microfluidic pump (SAMP) that utilizes asymmetric aspect ratio channels for the recording of human activity in the fluidic domain. An analytical model describing the SAMP's operation mechanism as a wearable microfluidic device was established. Fabrication of the SAMP was achieved using soft lithography from polydimethylsiloxane (PDMS). Benchtop experimental results and theoretical predictions were shown to be in good agreement. The SAMP was mounted on human skin and experiments conducted on volunteer subjects demonstrated the SAMP's capability to record human activity for hundreds of cycles in the fluidic domain through the observation of a stable liquid meniscus. Proof-of-concept experiments further revealed that the SAMP could quantify a single wrist activity repetition or distinguish between three different shoulder activities. [ABSTRACT FROM AUTHOR]

Background: Hepatic arterial infusion pump (HAIP) chemotherapy is an effective treatment for patients with unresectable intrahepatic cholangiocarcinoma (iCCA). HAIP chemotherapy requires a catheter inserted in the gastroduodenal artery and a subcutaneous pump. The catheter can be placed using an open or robotic approach. Objective: This study aimed to compare perioperative outcomes of robotic versus open HAIP placement in patients with unresectable iCCA. Methods: We analyzed patients with unresectable iCCA included in the PUMP-II trial from January 2020 to September 2022 undergoing robotic or open HAIP placement at Amsterdam UMC, Erasmus MC, and UMC Utrecht. The primary outcome was time to functional recovery (TTFR). Results: In total, 22 robotic and 28 open HAIP placements were performed. The median TTFR was 2 days after robotic placement versus 5 days after open HAIP placement (p < 0.001). One patient (4.5%) in the robotic group underwent a conversion to open because of a large bulky tumor leaning on the hilum immobilizing the liver. Postoperative complications were similar—36% (8/22) after robotic placement versus 39% (11/28) after open placement (p = 1.000). The median length of hospital stay was shorter in the robotic group—3 versus 5 days (p < 0.001). All 22 robotic patients initiated HAIP chemotherapy post-surgery, i.e. 93% (26/28) in the open group (p = 0.497). The median time to start HAIP chemotherapy was 14 versus 18 days (p = 0.153). Conclusion: Robotic HAIP placement in patients with unresectable iCCA is a safe and effective procedure and is associated with a significantly shorter TTFR and hospital stay than open HAIP placement. [ABSTRACT FROM AUTHOR]

Building energy consumption in China accounts for 45% of the total national energy consumption, with air conditioning energy consumption representing approximately two-thirds of that. Therefore, energy efficiency in buildings is of utmost importance. This study focuses on a chemical industrial park located along the Fujiang River and compares three heating and cooling supply schemes: the river water source heat pump system, which utilizes river water as the heat source and heat sink; the water cooling unit and boiler system, which uses water-cooled electric compression chillers for cooling and an oil-fired boiler system for heating; and the split air conditioning and gas water heater scheme, which relies on refrigerants such as fluorine-containing compounds for cooling and a gas water heater for heating. By calculating the energy consumption of the above three schemes and conducting a comparative analysis, it is found that the river water source heat pump system exhibits significantly higher energy efficiency throughout the year compared to the water cooling unit and boiler system and the split air conditioning and gas water heater scheme. This highlights the notable energy efficiency advantage of the river water source heat pump system. [ABSTRACT FROM AUTHOR]

This article describes a method for determining the geometric working volume of satellite positive displacement machines (pump and motor). The working mechanism of these machines is satellite mechanism consisting of two non-circular gears (rotor and curvature) and circular gears (satellites). Two variants of the satellite mechanism are presented. In the first mechanism, the rolling line of the rotor is a sinusoid "wrapped" around a circle. In the second mechanism, the rolling line of the rotor is a double sinusoid "wrapped" around a circle. A method for calculating the area of the working chamber as a function of the rotor rotation angle is presented, based on mathematical formulae of the rotor, the curvature and the satellite rolling lines. It has been shown that the second variant of the satellite mechanism is advantageously characterised by a larger difference between the maximum area of the working chamber and the minimum area of this chamber. New mathematical formulas have been proposed to calculate the area of the working chamber for any angle of rotation of the shaft (rotor) based on the maximum and minimum values of the area of this chamber. It was thus confirmed that the geometric working volume depends on the maximum and minimum area of a working chamber and on the height of the satellite mechanism. The analyses of the area of the working chamber were carried out both for the mechanism without gears (the area delimited by the rolling lines of the elements of the mechanism) and for the real mechanism with gears. Differences in the values of these fields were also detected. [ABSTRACT FROM AUTHOR]

A filter before the pump is one of the most important components in the head of the drip irrigation system. The filter before the pump can be used to preliminarily filter the irrigation water, and then reduce the damage to the pump and the working pressure of the filter system after the pump, finally extending the working duration of the filter system for stable and efficient operation of the drip irrigation system. However, most self-cleaning devices that are driven by motors cannot be interrupted in the filtration process when performing self-cleaning work, leading to the consumption of electric energy. The purpose of this study is to solve the frequent interruption of the filter system for the better self-cleaning performance of the filter before the pump. The Archimedes spiral turbine was applied to combine the hydraulic drive and self-cleaning in the selfcleaning process of the filter before the pump. A systematic investigation was made to explore the influence of blade stride, blade angle, and blade numbers on the rotation speed of Archimedes spiral turbine. A test platform was developed to evaluate the speed of Archimedes spiral turbine when the flow rate was 50-150 m³ /h (flow gradient was 25 m³ /h). At the same time, a series of simulation tests were carried out on the Archimedes spiral turbine with different parameters by computational fluid dynamics software. The experimental results show that the rotation speed of Archimedes spiral turbine gradually decreased with the increase of the blade stride (or the decrease of the number of single-blade helices), where the reduction amplitude gradually increased. There was a relatively small increase in the rotation speed of Archimedes spiral turbine, with the increase of blade angle and number of blades, whereas, the amplitude continuously decreased. The linear regression showed that the influencing level on the rotation speed was ranked in the descending order of the blade stride, blade angle and blade number. TOPSIS comprehensive evaluation showed that the optimal combination of structural parameters was obtained as follows: blade stride 133 mm, blade angle 90°, and the number of blades 1. The optimal scheme was then introduced into the hydraulicdriven self-cleaning filter before the pump in the self-cleaning test. It was found that the flow rate of the self-cleaning test group was stabilized in the range of 294.9-296.6 m³ /h after the initial flow reduction, while the flow reduction was only 1.13%-1.70% when the flow rate was 300 m³ /h and the sediment content was 0.9 g/L within 12 h. Better filter cleaning was achieved in the self-cleaning device of a hydraulic-driven Archimedes spiral turbine. The finding can provide a strong reference for the design and optimization of the hydraulic-driven self-cleaning filter before the pump. [ABSTRACT FROM AUTHOR]

In order to reduce the dry frictional wear of the end face of the mechanical seal used in the start and stop stage and under severe vibration conditions, the dry frictional wear simulation and experimental study of the textured face of the mechanical seal used in the pump were carried out. Firstly, the transient finite element model of the end face of dynamic and static ring seal with surface texture was established by ANSYS software. Based on Archard wear theory, the wear law of static ring ( graphite ring) under different texture spacing angle, edge length and rotation angle was analyzed, and the wear volume distribution of graphite ring was obtained. Then, the wear test of seal ring with different texture parameters was carried out by friction and wear testing machine under dry friction condition, and the surface morphology and wear mass of seal ring were obtained. Finally, The effects of different texture parameters on the wear mass of graphite ring and the mechanism of texture wear reduction were discussed. The experimental results show that the texture grooves are capable of hosting abrasive particles and generating a graphite transfer film to minimize wear; to minimize wear on the face of sealing ring, it is necessary to have a suitable texture area that can accommodate abrasive particles without causing excessive surface roughness; on average, with every 5 ° increase in texture spacing angle and 0. 1 mm decrease in edge length, the wear mass of graphite ring respectively decreases by approximately 7. 83% and 7. 35% . The wear mass of the graphite ring increases by 4. 25% on average when the rotation angle increases by 15 °. These findings can offer enhanced theoretical support towards surface texture design for pump mechanical seals, thereby bolstering their wear resistance. [ABSTRACT FROM AUTHOR]

Pumps are considered crucial mechanical devices in any industry. Especially, double-suction pumps, due to their high-flow design and high head, are utilized in diverse industrial sectors. However, despite these advantages, double-suction pumps are vulnerable to issues like losses, vibrations, and cavitation. Pump vibration is mainly caused by suction recirculation occurring at the impeller inlet. Therefore, this study investigates the impact of the impeller inlet design on enhancing the stability of double-suction pumps while expanding the operating flow range. Through a validated CFD study, the influence of the impeller inlet passage size on the head and efficiency was analyzed. Furthermore, research was conducted on the phenomenon of suction recirculation occurring at the impeller inlet, proposing design guidelines to minimize it, especially for operation at low flow rates. The results demonstrate that the ratio of the hub diameter to the shroud diameter at the impeller inlet significantly impacts the avoidance of recirculation at low flow rates. These findings are expected to contribute to improving the stability and efficiency of high-flow pumps. [ABSTRACT FROM AUTHOR]

Geothermal Power Plant is a power plant that utilizes geothermal fluids as its main source. Pressure Loss is a description of pressure loss at a point in the pipe caused by elevation. With the loss of pressure from pond to pond has elevation, a pump is needed to increase fluid flow. The pump used is a stage 7 pump. Therefore, a pressure loss analysis was carried out from pond to pond (balong) using the Harrison-Freeston correlation method to determine how much pressure loss was significant. From this method, that for the initial pressure in the injection well is 21 bar and for the pressure loss value of 0.06025481 bar [ABSTRACT FROM AUTHOR]

Environmentally friendly, high-output, high-efficiency compact pumps are in high demand in industrial fields such as chemical analysis and medical care. The efficiency of many small pumps is rather low, with peak efficiencies on the order of about 2%, even for commercially available pumps. Considering current environmental issues, improving the efficiency of motors and pumps is an important issue for preventing global warming. In this research, a small two-valve pump that can suck and discharge water by converting the energy of electromagnetic-vibration component resonance into kinetic energy was newly developed. In actual machine tests, two types of electromagnetic vibration pumps (I and II) with two-valve structures and different shapes were prototyped, and the shapes were optimized for efficiency. The type II vibration pump with an acrylic rod attached to the type I pump had excellent suction and discharge characteristics. The maximum efficiency was 12.2%, which is exceptional for a small pump. In addition, it was clarified by the actual machine test that the type II pump can stably discharge water at a high head of 2000 mm. The two types of pumps proposed in this paper were shown to be highly useful industrially in terms of performance, simplicity, cost, and operability and can be used selectively according to the application. Furthermore, since these pumps can be manufactured with a small number of parts, this paper shows their potential to contribute to environmental issues. [ABSTRACT FROM AUTHOR]

Subsurface drainage plays a crucial role in excess water removal through perforated pipes buried in the soil. The Red River Valley of eastern North Dakota and west central Minnesota often requires pumped drainage outlets due to its flat topography, with many modern systems incorporating variable frequency drives (VFD) for improved efficiency. VFDs adjust pump speeds to match drainage needs, but this dynamic operation complicates accurate flow rate estimation for edge-of-field monitoring. This project aimed to devise an automated method for calculating flow rate estimates from VFD pumping systems involving tank geometry, operational water levels, and pump duty cycling. Linear regressions with calibration data from a transit-time ultrasonic flowmeter produced mixed outcomes. Some linear regressions revealed errors in calculated versus measured flow rate of =14%, while other regressions showed errors nearing 40%. To address this, future efforts should explore methods incorporating the pump's electrical characteristics. This approach would provide a more accurate representation of the unstable and intricate pumping operations during transient conditions. [ABSTRACT FROM AUTHOR]

The increase in the efficiency of photoelectric panels from year to year is the basis for the large-scale use of this type of renewable energy source. Many subsidies are allocated for the use of renewable energy sources in our country. The use of solar energy, which is one of the renewable energy sources, is one of the most optimal solutions for creating intensive gardens in desert areas. In the article, the efficiency of the photoelectric system (PES) was compared with the portable generator (PG) used to supply water pumps with energy. It was determined that the payback period of PES is equal to 3.5 years compared to PG. It was found that there is an opportunity to use long-term green energy at almost no cost for the remaining 15-20 years. Instead of a system with a total power of 5kW, a PES system of 9.9kW was connected as an energy supply for irrigation works. 4.2 tons of CO2 emissions from PG are avoided annually. This practical work proved that the most problematic desertification, water supply and green energy sources can be solved in one place.

One of the possible directions of using renewable energy sources to save fuel and energy resources in Uzbekistan is the use of the hydropower potential of small rivers. The cost of electricity generated at micro and small hydroelectric power plant is already lower than the cost of electricity generated at traditional types of power plants, including gas turbine, wind, nuclear power plant and thermal power plant. In addition, due to constantly rising energy prices, the cost of electricity at traditional power plants is constantly increasing. The use of the hydropower potential of small rivers will contribute to the decentralization of the integrated energy system and improve energy supply to remote and hard-to-reach rural areas. Analysis of literature sources shows that the use of serial pumps as hydraulic turbines is a successful alternative to the use of specially designed hydraulic turbines for mini and small hydroelectric power plant. To reliably use pumps as hydraulic turbines, manufacturers need to obtain experimental performance of pumps in turbine mode, which can help expand their markets and better utilize available hydraulic potential.

Vertical axial-flow pumps have been widely used in the low head pumping station, due to their simple structure, excellent ventilation and heat dissipation, convenient installation, maintenance, and operation. But it is rarely used in the extra-low head pumping station, because the hydraulic performance is less than that of tubular pump. This study aims to improve the hydraulic performance of the vertical axial-flow pump system in the extra low head pumping stations. The numerical simulation was also carried out on the three-dimensional turbulent flow using the Reynolds time mean Naiver-Stokes equation and RNG turbulence model. The flow field of the inlet and outlet channel was calculated in the vertical axial-flow pump system. different submerged depth of the impeller center was selected for each impeller diameter of 3.0, 2.5, 2.0, and 1.5m. Meanwhile, the flow field and hydraulic loss of the flow channel were compared to the hydraulic performance of the vertical axial-flow pump system in the extra low head pumping stations. The submerged depth was set as the pump impeller center of 3.08, 2.38, and 1.68. Finally, the test had validated the simulation. The results show that the submerged depth of the impeller center shared little effect on the flow pattern and hydraulic loss of the elbow inlet channel. The same flow pattern was found in the inlet channel. The hydraulic loss of the channel was basically unchanged under the same impeller diameter and different submerged depths. The flow velocity changed gently and evenly, indicating the orderly turning flow in the elbow inlet channel. There was no bad flow pattern in the elbow inlet channel; There was a large impact of the submerged depth of the impeller center on the elevation arrangement of the vertical axial-flow pump system and the hydraulic performance of the siphon outlet channel. The layout space of the outlet channel increased in the direction of the façade with the increase of submerged depth of the impeller center. The flow pattern was gradually improved in the siphon outlet channel, where the current turned more gently. The hydraulic loss of the siphon outlet channel basically tended to decrease. There was an increase in the efficiency of the pump system. The efficiency was 75.92% at the optimal operating point of the model test under extra low head conditions. The energy performance of the pump system was also consistent with the model test. The increasing submerged depth of the pump impeller center also led to an increase in the investment in the civil engineering of the pumping station. The pumping station can be required to increase the submerged depth of the impeller center, according to the added value of civil investment and the reduced value of operating cost. The finding can provide a sound reference to design the vertical axial-flow pump system in the extra-low head pumping stations. [ABSTRACT FROM AUTHOR]

Hypoparathyroidism is the most common endocrinological feature in children with Sanjad-Sakati syndrome. Treatment includes active vitamin D and calcium supplementation. Here, we report a case of a newborn with Sanjad-Sakati syndrome who had severe hypocalcemia since birth who responded to PTH subcutaneous pump infusion. The child was born at 35 weeks with hypocalcemia since the first day of life. The standard medical treatment proved ineffective for the newborn, necessitating the administration of unusually high doses of oral and IV calcium and vitamin D analogue for a 2 months. As a result, intermittent subcutaneous injections of PTH were commenced, resulting in an initial improvement in calcium levels, although this proved to be short-lived. Subsequently, a switch to continuous infusion via a Medtronic Vio pump was made, which unfortunately resulted in iatrogenic hypercalcemia, requiring management of hypercalcemia. Later, calcium carbonate and alfacalcidol were resumed at a lower dosage and continued to have average requirements for patients with hypoparathyroidism. PTH subcutaneous infusion can be highly effective in refractory hypocalcemia cases and can significantly impact the treatment course and facilitate hospital discharge as seen in our case. Careful dosage and monitoring are required to avoid iatrogenic hypercalcemia. [ABSTRACT FROM AUTHOR]

Microinfusions are commonly used for the administration of catecholamines, but start-up delays pose a problem for reliable and timely drug delivery. Recent findings show that venting of the syringe infusion pump with draining of fluid to ambient pressure before directing the flow towards the central venous catheter does not counteract start-up delays. With the aim to reduce start-up delays, this study compared fluid delivery during start-up of syringe infusion pumps without venting, with ambient pressure venting, and with central venous pressure (CVP)-adjusted venting. Start-up fluid delivery from syringe pumps using a microinfusion of 1 mL/h was assessed by means of liquid flow measurement at 10, 60, 180 and 360 s after opening the stopcock and starting the pump. Assessments were performed using no venting, ambient pressure venting or CVP-adjusted venting, with the pump placed either at zero, − 43 cm or + 43 cm level and exposed to a simulated CVP of 10 mmHg. Measured fluid delivery was closest to the calculated fluid delivery for CVP-adjusted venting (87% to 100% at the different timepoints). The largest deviations were found for ambient pressure venting (− 1151% to + 82%). At 360 s after start-up 72% to 92% of expected fluid volumes were delivered without venting, 46% to 82% with ambient pressure venting and 96% to 99% with CVP-adjusted venting. CVP-adjusted venting demonstrated consistent results across vertical pump placements (p = 0.485), whereas the other methods had significant variances (p < 0.001 for both). In conclusion, CVP-adjusted venting effectively eliminates imprecise drug delivery and start-up delays when using microinfusions. [ABSTRACT FROM AUTHOR]

Diaphragm dry vacuum pumps are used in a wide range of industries, including low-vacuum applications for semiconductor manufacturing processes, analysis, physics and chemistry, medical care, and food industries. In this report, we introduce the features and structure of our diaphragm dry vacuum pumps, as well as the pumps in general. [ABSTRACT FROM AUTHOR]

The principle of media separation bearing design is presented. Experiments to evaluate the performance of such bearings in the rotor axial unloading unit of a labyrinth screw pump are described. [ABSTRACT FROM AUTHOR]

The cavitation erosion failure of pumps or valves induces the low efficiency and reduced service life of nuclear reactors. This paper reviews works regarding the cavitation erosion of pumps and valves in the nuclear power industry and academic research field. The cavitation erosion mechanisms of materials of pumps and valves are related to the microstructure and mechanical properties of the surface layer. The cavitation erosion resistance of austenitic stainless steel can be ten times higher than that of ferritic steel. The cavitation erosion of materials is related to the hardness, toughness, and martensitic transformation capacity. Erosion wear and erosion–corrosion research is also reviewed. Erosion wear is mainly influenced by the hardness of the material surface. Erosion–corrosion behavior is closely connected with the element composition. Measures for improving the cavitation erosion of pumps and valves are summarized in this paper. The cavitation erosion resistance of metallic materials can be enhanced by adding elements and coatings. Adhesion, inclusion content, and residual stress impact the cavitation erosion of materials with coatings. [ABSTRACT FROM AUTHOR]

Background: Here, the perspective of patients with primary and secondary immunodeficiency receiving subcutaneous immunoglobulin (SCIg) via introductory smaller size pre-filled syringes (PFS) or vials were compared. Methods: An online survey was conducted in Canada by the Association des Patients Immunodéficients du Québec (APIQ) (10/2020–03/2021). Survey questions included: reasons for choosing SCIg packaging and administration methods, training experiences, infusion characteristics, and switching methods. The survey captured structured patient-reported outcomes: treatment satisfaction and its sub-domains, symptom state, general health perception, and physical and mental function. Respondents using PFS were compared with vial users, overall and stratified by their administration method (pump or manual push). Results: Of the 132 total respondents, 66 respondents used vials, with 38 using a pump and 28 using manual push. PFS (5 and 10 mL sizes) were being used by 120 respondents, with 38 using a pump and 82 using manual push. PFS users were associated with a 17% lower median (interquartile range) SCIg dose (10 [8, 12] vs. 12 [9, 16] g/week, respectively), a significantly shorter infusion preparation time (15 [10, 20] vs. 15 [10, 30] mins, respectively), and a trend for shorter length of infusion (60 [35, 90] vs. 70 [48, 90] mins, respectively) compared with those on vials. Patient-reported treatment satisfaction scores were overall similar between vial and PFS users (including on the domains of effectiveness and convenience), except for a higher score for vials over PFS on the domain of global satisfaction (p=0.02). Conclusions: Consistent with prescribing that reflects a recognition of less wastage, PFS users were associated with a significantly lower SCIg dose compared with vial users. PFS users were also associated with shorter pre-infusion times, reflecting simpler administration mechanics compared with vial users. Higher global satisfaction with treatment among vial users compared with PFS users was consistent with users being limited to smaller PFS size options in Canada during the study period. Patient experience on PFS is expected to improve with the introduction of larger PFS sizes. Overall, treatment satisfaction for SCIg remains consistently high with the introduction of PFS packaging compared with vials. [ABSTRACT FROM AUTHOR]

Start-up delays of syringe pump assemblies can impede the timely commencement of an effective drug therapy when using microinfusions in hemodynamically unstable patients. The application of the venting principle has been proposed to eliminate start-up delays in syringe pump assemblies. However, effectively delivered infusion volumes using this strategy have so far not been measured. This invitro study used two experimental setups to measure the effect of the venting principle compared to a standard non-venting approach on delivered start-up infusion volumes at various timepoints, backflow volumes, flow inversion and zero drug delivery times by means of liquid flow measurements at flow rates of 0.5, 1.0 and 2.0 mL/h. Measured delivered initial start-up volumes were negative with all flow rates in the vented and non-vented setup. Maximum backflow volumes were 1.8 [95% CI 1.6 to 2.3] times larger in the vented setup compared to the non-vented setup (p < 0.0001). Conversely, times until flow inversion were 1.5 [95% CI 1.1 to 2.9] times shorter in the vented setup (p < 0.002). This led to comparable zero drug delivery times between the two setups (p = 0.294). Start-up times as defined by the achievement of at least 90% of steady state flow rate were achieved faster with the vented setup (p < 0.0001), but this was counteracted by the increased backflow volumes. The application of the venting principle to the start-up of microinfusions does not improve the timely delivery of drugs to the patient since the faster start-up times are counteracted by higher backflow volumes when opening the three-way stopcock. [ABSTRACT FROM AUTHOR]

PDAM Surya Sembada Surabaya’s energy cost in 2021 amounted to Rp 147.654.439.569, with an energy cost ratio of 24.37%, and the electricity cost of production unit accounted for 76% of the total energy consumption of PDAM. The relatively flat topography does not allow gravity-based systems for water supply. Ageing equipment has decreased overall pump efficiency (ηpt) and increased energy consumption, particularly in Ngagel I WTP, built in 1922, necessitating an energy audit. Energy audit includes measuring pump flow rate and pressure, voltage, current, power factor, pump and motor pump rotation, and temperature. Analysis shows that raw water pumps U2, U3, U5, and S1 and distribution pumps U1, U3, and T4 are still in good condition. However, raw water pump U6 and distribution pumps U6, S1, and S2 require reconditioning and impeller adjustment due to declining efficiency. Furthermore, PDAM must inspect the distribution pump T1 with the lowest efficiency value (49.77%) to determine the appropriate repairs. The research results are action recommendations expected to serve as input and considerations for PDAM in their efforts to improve energy efficiency. [ABSTRACT FROM AUTHOR]

The high cost of fuel has become a significant challenge for farmers in operating water pumps for irrigation in agricultural fields. The pumps are rendered economically inefficient due to the associated high operational costs. Therefore, the proposed solution to address this issue is the utilization of wind energy. Wind energy is converted into electrical energy to power water pumps. This research aims to: determine the average power in the wind use statistical method based on the average of windspeed, evaluate the efficiency of wind power generators, and select the appropriate wind turbine type for installation in the Kedungweru region, Kebumen, Central Java. The study was conducted at the Wind Power Plant (PLTB) in Kedungweru Village, Kebumen Regency, Central Java, and the Laboratory of Thermal Systems Engineering and Renewable Energy at Jenderal Soedirman University. Sampling methods included measuring wind speed, voltage, and current, as well as data from the Hybrid Optimization of Multiple Energy Resources (HOMER) software. The variables of this research were maximum/minimum/average wind speed, electric pump load, power generated by the wind power plant, and the efficiency of wind turbine performance. The results of the study indicate that Kedungweru has a relatively good wind energy potential, with an average wind speed of 4.79 m/s. From the HOMER simulation using 2 AWS HC 650 W wind turbines, the generated electrical energy reached 2,543 kWh/year. Additionally, the simulation showed an electrical surplus of 33.2%, indicating a well-performing system as almost all generated energy can be efficiently utilized without wastage. Thus, the use of wind energy as a renewable resource for irrigating agricultural fields can be an efficient and economical solution to address the high operational costs resulting from expensive fuel prices.

Rational and energy efficient operation of pumps for pumping and transporting liquids used in difficult conditions of mining is possible due to the implementation and use of modern methods of managing the operating modes of the pumps. Nowadays, the methods and resources used to regulate the operating modes of pumping units do not meet modern requirements, and many mines still use outdated methods of regulating the operating modes of pumps, which entails significant energy losses and an increase in the cost of the transported liquid. In the article, the methods of reducing electricity losses and the impact on the performance of pumping units were considered. It is concluded that this method of regulating work makes it possible to operate pumping units in the working area. Our article considers and experimentally substantiates the possibility of achieving savings in electrical energy, as well as increasing the reliability of the operation of pumping units based on the use of modern methods of regulating operating modes.

In this paper, a novel flow control strategy which is the inlet throttled pump was used to design an angular velocity control system for rotary actuator. Inlet throttled systems have good performance in addition to their high efficiency compared to traditional valve-controlled systems. The flow in the proposed system is adjusted by a valve that is positioned at the pump inlet with the purpose of reducing the energy loses across the valve. This regulated flow is used then to control the actuator angular velocity. The system was modeled and the open loop stability and performance were studied. In order to improve the system performance, proportional-integralderivative (PID) and H-infinity controllers have been designed. The multiplicative uncertainty was analyzed to assess the robustness of the feedback control system where six parameters were considered uncertain within a range of +10%. The robust stability and performance requirements of the closed-loop angular velocity control system were assessed in the frequency domain. The time response of the system showed that the system is stable with both PID and H-infinity controllers. The PID controller have the advantages of simplicity and high response speed while the H8 controller provides better nominal performance, robustness, and stability. The H8 controller can handle parametric uncertainty without requiring pure integral term which is a significant advantage over the PID controller. On the other hand, the PID controller falls short of achieving robust performance, making it less suitable for systems that require high levels of performance and robustness. In summary, the H8 controller is a more comprehensive solution for ensuring the best performance of a system. In contrast, the PID controller may be more suitable for systems with less stringent performance requirements. [ABSTRACT FROM AUTHOR]

Waste Heat Recovery (WHR) System which converts exhaust heat into power was evaluated on actual vehicles. as a result, WHR system tuned exhaust heat into power and the fuel consumption was improved 1.6 % in highway mode. The fuel consumption improvement effect by mounting a retrofit system of exhaust heat recovery and power regeneration was confirmed. This report describes the process of the examination and the results and problems of the system. [ABSTRACT FROM AUTHOR]

This work shows the results of a study of reliability indicators, indicates the number of accidents, failures, and defects of pumping units of the pumping station "Kyzyl-Tepa" for a 5-year period, calculates the intensity of the occurrence of events and the probability values of initiating events, and presents the graphs of changes in the probabilities of initiating events for 5 and 60 years based on experimental and operational data, as well as theoretical calculation of values of the probability of initiating events. [ABSTRACT FROM AUTHOR]

The characteristics of thrust bearings used in NPP circulation pumps are presented and discussed. An analysis of the results of the tribological tests of new materials and coatings for solving the issues of the operability of friction units with hydrodynamic lubrication at high speeds and loads is given. [ABSTRACT FROM AUTHOR]

Vertical centrifugal pumps play a crucial role in numerous water conservancy projects. However, their continuous operation can lead to the development of cracks or even fractures in some centrifugal pump blades, resulting in a substantial adverse impact on the operation of the pumping station unit and jeopardizing safe production. This study employs the fluid-structure interaction method to comprehensively investigate the modal characteristics of the impeller, both in an air environment and immersed in water. Furthermore, the analysis of static and dynamic stress attributes is conducted. The natural frequency of the impeller when submerged in water is significantly lower than its frequency in an air medium, typically accounting for approximately 0.35 to 0.46 of the air-based natural frequency. There are conspicuous stress concentrations at specific locations within the system, specifically at the rounded corners of the blade back exit edge, the impeller front cover, the middle of the blade inlet edge, and the junction where the blade interfaces with the front and back cover. It is crucial to underscore that when the system operates under high-flow or low-flow conditions, there is a pronounced stress concentration at the interface between the impeller and the rear cover plate. Any deviation from the intended design conditions results in an escalation of equivalent stress levels. Through dynamic stress calculations during a single rotational cycle of the impeller, it is discerned that the cyclic nature of stress at the point of maximum stress is primarily influenced by the number of blades and the rotational velocity of impeller. This research carries significant implications for effectively mitigating blade fractures and cyclic fatigue damage, thereby enhancing the operational reliability of vertical centrifugal pumps in water conservancy applications. [ABSTRACT FROM AUTHOR]

The key characteristics of thrust and radial bearings used in NPP circulation pumps are presented and discussed. The operating conditions of the thrust and radial bearing of the main circulation pump are considered. The comparative characteristics of bearings depending on the operating conditions are given. Recommendations are given on the choice of thrust and radial bearings in nuclear industry pumps. [ABSTRACT FROM AUTHOR]

In this study, experimental and numerical analysis studies of a submersible pump performance were carried out. First of all, the performance tests were carried out with a four-stage pump with the most efficient operating point of 140 m³/h in the test setup in the company. Then, numerical studies were made for the four-stage model of the same pump with Computational Fluid Dynamics. In the study, the head and efficiency values of the pump were calculated for different flow rates. In addition, the velocity and pressure changes in the pump section are presented visually for the numerical analysis results. As a result, at 140 m³/h flow rate, which is the optimum operating point of the submersible pump, the difference between the experimental and numerical results is about 3.15% in head, while it is around 9% in efficiency. The results brought to the literature are of the quality to be used for validation in commercial and academic studies due to the similarity of efficiency and head curves. [ABSTRACT FROM AUTHOR]