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Background: Connecting an infusion line to a closed stopcock results in pressurization of fluid within the syringe infusion pump assembly leading to flow irregularities when opening the stopcock and activating the pump. Aims: It was the purpose of this study to assess the extent of pressurization under different conditions and its impact on start‐up fluid delivery. Methods: Intraluminal pressures and start‐up fluid delivery at 1 mL/h flow rate were assessed with connection of the infusion line 1 min (delayed connection) or immediately after purging (immediate connection) using two different infusion lines made from polyvinylchloride (PVC) or polyethylene (PE). Results: Delayed connection resulted in an increase of intraluminal pressures from zero to 5.1 [4.5 to 5.7] mmHg with the PVC line and from zero to 47.1 [44.8 to 49.3] mmHg with the PE line (mean difference 42.0 [95% CI 39.3–44.7] mmHg; p <.0001). Immediate connection resulted in an increase of intraluminal pressures from zero to 44.3 [41.8–46.8] mmHg with the PVC line and from zero to 61.3 [57.2–65.4] mmHg with the PE line (mean difference 17.0 [95% CI 11.8–22.2] mmHg; p <.0001). The increase in intraluminal pressures was significantly higher with PE lines for both delayed and immediate connection when compared to the PVC lines (mean difference 29.5 [95% CI 19.3–39.7] mmHg; p <.0001). Related fluid volumes delivered at 10 s and 360 s after starting the pump ranged from −252% to 1321% (10 s) of expected infusion volumes and from 59% to 129% (360 s), respectively. Conclusions: Both, timing of infusion line connection after purging and infusion line characteristics considerably affect intraluminal pressures and start‐up fluid delivery when connecting a new syringe infusion pump assembly to a closed stopcock. Consecutive alterations in drug administration can have considerable hemodynamic consequences when dealing with catecholamine infusions in critically ill patients. [ABSTRACT FROM AUTHOR]

Pumps represent a quintessential type of fluid machinery and play a pivotal role in global economic development, especially in the hydropower industry. However, as their application range and single unit capacity continue to increase, the occurrence of rotating stall phenomena caused by internal flow instability has become more frequent. This phenomenon is especially prominent in pumps with semi-open impellers, where the presence of tip leakage flow (TLF) instability accelerates the rotating stall phenomenon. Over the past few decades, extensive research has been conducted to investigate the characteristics of rotating stall in pumps. As a result, there is now a preliminary understanding of the phenomenon of rotating stall induced by tip leakage flow in pumps. However, a significant gap remains in fully comprehending the underlying mechanism of this phenomenon. This review comprehensively reviews the research progress made in understanding the relationship between pump tip leakage flow instability and rotating stall. It encompasses various aspects, including the formation mechanism of tip leakage flow, the structure of tip leakage vortex (TLV) under stall conditions, the correlation between dynamic characteristics of tip leakage flow and rotating stall, as well as methods for mitigating rotating stall through tip leakage suppression. Finally, some promising potential stall suppression method is discussed to provide some guidance for the fields of fluid machinery. [ABSTRACT FROM AUTHOR]

Micropumps have an important influence on the field of microfluidics, with particular interest in pumps based on liquid metal that operate without mechanical moving parts. While previous research has primarily focused on pumping alkaline media, this article aims to advance the field by demonstrating a liquid metal pump suitable for acidic environments. A key strategy involves reducing the interfacial tension between the liquid metal and the surrounding solution through the addition of surface‐active anions (I−). Theoretical analysis first evaluates the effectiveness of this approach. These experimental results confirm that increasing KI concentrations leads to a decrease in interfacial tension, enabling the deformation and actuation of liquid metal droplets at lower voltages compared to acidic media alone. Subsequently, an acidic media pump is constructed, and various parameters influencing its performance are examined, including acidity, iodide anion concentration, voltage, frequency, and droplet volume. This research offers strategies for developing liquid metal pumps with high flow rates and low energy consumption, thereby expanding the application potential of liquid metal in microfluidics. [ABSTRACT FROM AUTHOR]

Background: Hydrocephalus, an accumulation of cerebrospinal fluid (CSF) in the ventricles of the brain, is often treated via a shunt system to divert the excess CSF to a different compartment; if left untreated, it can lead to serious complications and permanent brain damage. It is estimated that one in every 500 people are born with hydrocephalus. Despite more than 60 years of concerted efforts, shunts still have the highest failure rate of any neurological device requiring follow-up shunt revision surgeries and contributing to the $2 billion cost of hydrocephalus care in the US alone. The absence of a tested and validated long-term in-vitro model that can incorporate clinically relevant parameters has limited hypothesis-driven studies and, in turn, limited our progress in understanding the mechanisms of shunt obstruction in hydrocephalus. Testing clinical parameters of flow, pressure, shear, catheter material, surface modifications, and others while optimizing for minimal protein, cellular, and blood interactions has yet to be done systematically for ventricular catheters. Several studies point to the need to not only understand how cells and tissues have occluded these shunt catheters but also how to stop the likely multi-faceted failure. For instance, studies show us that tissue occluding the ventricular catheter is primarily composed of proliferating astrocytes and cells of the macrophage lineage. Cell reactivity has been observed to follow flow gradients, with elevated levels of typically pro-inflammatory interleukin-6 produced under shear stress conditions greater than 0.5 dyne/ . But also, that shear can shift cellular attachment. The Automated, In vitro Model for hydrocephalus research (AIMS), presented here, improves upon our previous long-term in vitro systems with specific goals of recapitulating bulk pulsatile cerebrospinal fluid (CSF) waveforms and steady-state flow directionality relevant to ventricular catheters used in hydrocephalus. Methods: The AIMS setup was developed to recapitulate a wide range of physiologic and pathophysiologic CSF flow patterns with varying pulse amplitude, pulsation rate, and bulk flow rate with high throughput capabilities. These variables were specified in a custom-built user interface to match clinical CSF flow measurements. In addition to flow simulation capabilities, AIMS was developed as a modular setup for chamber testing and quality control. In this study, the capacity and consistency of single inlet resin chambers (N = 40), multidirectional resin chambers (N = 5), silicone chambers (N = 40), and PETG chambers (N = 50) were investigated. The impact of the internal geometry of the chamber types on flow vectors during pulsatile physiologic and pathophysiologic flow was visualized using Computational Fluid Dynamics (CFD). Dynamic changes in ventricular volume were investigated by combining AIMS with MRI-driven silicone model of a pediatric patient's ventricles. Parametric data were analyzed using one-way analysis of variance (ANOVA) or repeated measures ANOVA tests. Non-parametric data were analyzed using Kruskal-Wallis test. For all tests, a confidence interval was set at 0.95 (α = 0.05). In a subset of experiments, AIMS was also tested for its capability to measure the flow of florescent microspheres through the holes of unused and explanted ventricular catheters. Results: The analysis of peak amplitude through chambers indicated no statistically significant differences between the chamber batches. This high throughput setup was able to reproduce clinical measurements of bulk CSF flow tested in up to 50 independent pump channels such that there was no exchange of solution or flow interference between adjacent channels. Physiologic and pathophysiologic clinical measurements of CSF flow patterns were recapitulated in all four chamber types of the AIMS setup with and without augmented compliance. The AIMS setup's automated priming feature facilitated constant fluid contact throughout the study; no leaks or ruptures were observed during short- (up to 24 h) or long-term (30 days) experiments. Finally, qualitative microscopy long-exposure image capture revealed microsphere movement under steady-state and pulsatile flow of spheres moving into the shunt catheter. Conclusion: AIMS successfully simulates clinical measurements of physiologic and pathophysiologic CSF pulsation amplitude and frequency, as exemplified using clinical data of CSF exiting an externalized ventricular drain in four distinct chamber types, as well as flow patterns from a valve. This provides a promising platform for investigating the direct interaction between CSF, immune cells, and shunt hardware under relevant flow conditions when both the source of bulk flow and pulsatility are coupled. The implementation of this system in conjunction with a previously reported three-dimensional hydrogel scaffold in future work will enhance our understanding of shunt-related complications and improve treatment strategies by reducing the obstruction rate. [ABSTRACT FROM AUTHOR]

The International Society for Pediatric and Adolescent Diabetes (ISPAD) guidelines represent a rich repository that serves as the only comprehensive set of clinical recommendations for children, adolescents, and young adults living with diabetes worldwide. This chapter builds on the 2022 ISPAD guidelines, and summarizes recent advances in the technology behind insulin administration, with special emphasis on insulin pump therapy, especially on glucose-responsive integrated technology that is feasible with the use of automated insulin delivery (AID) systems in children and adolescents. [ABSTRACT FROM AUTHOR]

The crustacean molting cycle is triggered by the elevation of ecdysteroid levels in the hemolymph during late pre‐molt. It is known that these animals absorb water through the intestine and gills to promote bodily swelling and rupture of the old exoskeleton. The participation of two membrane proteins responsible for the most uptake of water during the late pre‐molt has been shown in the gill and gut cells of the freshwater shrimp Palaemon argentinus: Na+/K+‐ATPase (NKA), which generates an osmoionic gradient, and Aquaporins (AQPs), water channels, which provide higher water permeability. Studies investigating the action of ecdysteroids on these proteins are scarce. Therefore, we investigated 20‐hydroxyecdisone (20E) in relation to the regulation of NKA and AQPs in the gill and gut cells of P. argentinus. We exposed primary cultures of both gut and gill cells to 20E. Gill cells treated with hormone in the presence of NKA‐blockers, exhibited a reduction in volume, and cells treated with 20E showed a greater expression of NKA than untreated cells. Additionally, gills cells treated with 20E showed an increase in volume (∼60%), which the aquaporin inhibitor (HgCl2) prevented. The participation of AQPs in the influx of water was corroborated by a greater expression of AQP in cells treated with 20E compared to untreated cells. Gut cells of animals in intermolt exposed to hormone (20E) maintained their initial cell volume. With the addition of HgCl2, these cells showed a reduction in volume similar to cells of animals in pre‐molt. Immunocytochemistry showed a high expression of AQP in gut cells treated with 20E. These findings suggest that 20E regulates the expression of AQP and NKA in the late pre‐molt, to provide water uptake for molting. This work offers new perspectives concerning the molting hormone, placing it as a crucial part of water uptake for ecdysis. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive review of key approaches to suppressing stall flow in pumps, offering insights to enhance pump performance and reliability. It begins by outlining the formation mechanisms and characteristics of stalls, followed by an in-depth analysis of various stall types. The discussion highlights passive and active flow control methods, emphasizing their roles in suppressing stall phenomena. Passive flow-control strategies, including surface roughness, grooves, obstacles, fixed guide vanes, and vortex generators, are examined with a focus on their mechanisms and effectiveness in suppressing stall. Similarly, active flow-control techniques, such as jets and adjustable guide vanes, are explored for their capacity to regulate the flow field and suppress stall. The novelty of this review lies in its exploration of the effectiveness of passive and active flow-control methods in suppressing pump stall, with a focus on their mechanisms of action and the underlying principles of stall formation. The findings reveal that appropriate flow-control measures can mitigate laminar flow separation and reduce performance losses associated with stall. However, careful attention must be given to the optimal arrangement of control devices. Finally, the article highlights the limitations of current implementations of combined active and passive flow-control methods while offering insights into the future potential of advanced flow-control technologies in regard to suppressing stall. [ABSTRACT FROM AUTHOR]

Performance enhancement of a system is always preferred. The thermal efficiency of currently available simple solar water heater (SSWH) are generally in between 50 and 60%. The present work describes the use of different inserts like twisted tapes and springs on the performance enhancement of flat plate collector (FPC) of modified solar water heater (MSWH) under natural and forced convective situations for the performance enhancement. The experimental studies has been carried out at Nagpur ((21.1241° N, 79.0023° E) to investigate the performance of FPC of a MSWH with different inserts. Two different experimental setups were analyzed and compared for the investigation of performance. The first experimental setup investigated without any modification and under natural convection while other setups are investigated with modifications and under natural and forced convective situations. The experiments have been performed with plain twisted tape (PTT) inserts having five twisted ratios (y/W) viz. 2.0, 2.5, 3, 3.5 and 4, twisted tape with helical coil spring inserts (TTS) having three twisted ratios (y/W) viz. 2.0, 3 and 4, and traverse twisted tape (TTT) having three twisted ratios (y/W) viz. 2.0, 3 and 4. The PTT, TTS & TTT inserts are used with a fixed thickness of 1 mm, width 12 mm and length 1900 mm. The experiments has conducted for the different Reynolds number of, 4000 ≤ Re ≤ 24,000 using water as a working fluid. In all the cases Nusselt number increases with Reynolds number but the friction factor decreases. Some conclusions and recommendations based upon the above experimentation are presented at the end. [ABSTRACT FROM AUTHOR]

Purpose: to develop an algorithm for arranging a pumping unit for irrigation purposes taking into account the energy-saving operating mode of a diesel internal combustion engine and with the ability to adjust head and rate specifications in a wide, acceptable range. Materials and methods. The studies were conducted using a simulated scheme that includes a mobile pumping unit that withdraw irrigation water from a canal and transfers it via a pipeline to two center pivot sprinklers operating alternately. Generally accepted formulas to calculate power, torque, and flow were used. The proportionality law, selection method, and graphoanalytical method were applied. Results. The proposed algorithm has the following stages: source data capture – preliminary selection of a pump and an internal combustion engine – establishment of the pump speed control range – calculation of head, flow rate, power and torque on the pump shaft – digitization of the main characteristics of the internal combustion engine in a given crankshaft speed limit – comparison of pump and engine torques – comparison of pump and internal combustion engine capacities – analysis of graphic data on the torque and power of the pump and internal combustion engine – calculation of the energy characteristic of the water flow (Q·H) and construction of its dependence on RPM – clarification of the number of revolutions of the engine crankshaft to ensure the specified head-flow characteristics of the pump. In this case, the selection of the internal combustion engine was made taking into account its operation within the crankshaft speed limits providing the minimum specific fuel consumption. Conclusions. The developed algorithm allows selecting elements of a reclamation pumping unit taking into account the energy-saving operating mode of the internal combustion engine, as well as specifying the required pump shaft speed for the required performance.

This study introduces a novel method for controlling an autonomous photovoltaic pumping system by integrating a Maximum Power Point Tracking (MPPT) control scheme with variable structure Sliding Mode Control (SMC) alongside Perturb and Observe (P&O) algorithms. The stability of the proposed SMC method is rigorously analyzed using Lyapunov's theory. Through simulation-based comparisons, the efficacy of the SMC controller is demonstrated against traditional P&O methods. Additionally, the SMC-based system is experimentally implemented in real time using dSPACE DSP1104, showcasing its robustness in the presence of internal and external disturbances. Robustness tests reveal that the SMC controller effectively tracks Maximum Power Points (MMPs) despite significant variations in load and solar irradiation, maintaining optimal performance even under challenging conditions. The results indicate that the SMC system can achieve up to a 70% increase in water flow rates compared with systems without MPPT controllers. Furthermore, SMC demonstrated high sensitivity to sudden changes in environmental conditions, ensuring efficient power extraction from the photovoltaic panels. This study highlights the advantages of integrating SMC into Photovoltaic Water Pumping Systems (PV-WPSs), providing enhanced control capabilities and optimizing system performance. The findings contribute to the development of sustainable water supply solutions, particularly in remote areas with limited access to the electrical grid. [ABSTRACT FROM AUTHOR]

The cavitation phenomenon presents a significant challenge in pump operation since the losses incurred by cavitation adversely impact pump performance. The many constraints of conventional anti-cavitation techniques have compelled researchers to explore biological processes for innovative alternatives. Consequently, the use of bionanotechnology for anti-cavitation pumping has emerged as a prominent study domain. Despite the extensive publication of publications on biomimetic technology, research concerning the use of anti-cavitation in pumps remains scarce. This review comprehensively summarizes, for the first time, the advancements and applications of bionic structures, bionic surface texture design, and bionic materials in pump anti-cavitation, addressing critical aspects such as blade leading-edge bionic structures, bionic worm shells, microscopic bionic textures, and innovative bionic coatings. Bionic technology may significantly reduce cavitation erosion and improve pump performance by emulating natural biological structures. This research elucidates the creative contributions of biomimetic designs and their anti-cavitation effects, hence boosting the anti-cavitation performance of pumps. This work integrates practical requirements and anticipates future applications of bionic technology in pump anti-cavitation, offering a significant research direction and reference for scholars in this domain. [ABSTRACT FROM AUTHOR]

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]

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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.

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.;

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 article is devoted to the study of a little-known scroll by the 18th century Japanese artist Shiba Kōkan1 . The provenance of the scroll and the reasons for its poor study are considered. The main attention is paid to the analysis of the history of the scroll and the symbolism of three elements of images on it: wave, triad, and flame-fire. These three elements are important components of the Japanese cultural and artistic code, forming it since ancient times while changing over time and retaining their significance in contemporary culture. The multiple meanings of the symbolism of the images on the scroll allow us to propose at least two possibilities for its interpretation: as a separate and independent work and as an illustration of the artist’s diary-pamphlet written by him at the end of his life. In this article, we deal primarily with the first possibility. The duality of the perception of the wave and the sea in the cultural code is reflected in the scroll. The islanders realized the sea not only as a physically surmountable barrier, but also as a kind of translator of information. The central part of the scroll depicts a meeting at the table of three wise men from Japan, China and the West, which is analogous to the illustration of the famous Chinese parable Three Wise Men Tasting Vinegar. The article analyzes in detail the portraits of the three participants of the meeting, considers possible prototypes of the Japanese character and the collective images of the Chinese and the European ones, confirmed by the carefully studied symbolism of their appearance, as well as the objects spread out in front of them. The burning Buddhist pagoda depicted at the top of the scroll and the three groups of people trying to extinguish it seem to be an allegory for the gathering around the table. It is also seen in the use of different ways and means of extinguishing the fire by groups of Japanese, Chinese, and Europeans. It seems that the scroll also has Buddhist connotations. The image reflects the irony, mockery, and laughter, which are among the characteristics of Edo culture. The final part of the article speculates on the possible dating and authorship of the scroll.

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 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]

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 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.

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]

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]