Pump Output Research Articles

Continuous‐wave and cavity‐dumped 1064 nm Nd:YVO4 laser based on the magneto‐optical effect

AbstractIn this paper, continuous‐wave and cavity‐dumped Nd:YVO4 lasers are studied. Firstly, through theoretical analysis and numerical simulation, the output characteristics of a continuous‐wave laser based on the magneto‐optical effect are analysed using the rate equation. The continuous adjustment of output power and pump threshold power is realised using the magneto‐optical effect to rotate the polarisation direction of laser. The theoretical simulation results show that the output power of the laser could be effectively controlled under different magnetic field intensities. On this basis, the authors explore the cavity‐dumped laser system based on the magneto‐optical effect. By adjusting the intensity of the magnetic field and rising edge time, the pulse width and waveform could be flexibly adjusted. The relationship between the magnetic field intensity in the low Q period and the spot radius of the pump and the signal beam and the output energy and the output pulse waveform is analysed. These research results lay a foundation for further optimising the design and application of magneto‐optical effect lasers.

Numerical simulation study of vortex cavitation and induced pulsation characteristics in spiral lobe pumps

Lobe pumps are used in many different sectors because of their versatility and effectiveness for managing multiphase flows. In this study, three-dimensional unsteady numerical simulations are performed to evaluate the vortex cavitation phenomenon in these pumps. The work combines dynamic meshing techniques, advanced vortex recognition methods, and a full cavitation model to provide insight into the genesis, evolution, and influence of vortex cavitation on pump performance. The results of the study demonstrate that under high-speed and high-pressure conditions, vortex flow occurs at the edge of the rear of the rotor lobe in the suction chamber of the lobe pump, resulting in the production of vortex cavitation. Cavitation is most strong at the core of the vortex, while the degree of cavitation at the edge of the vortex gradually diminished. The gas volume fraction reduces from 0.135 to 0.0832, and this makes the pressure decrease from 1.055 to 1.02 MP. The process of genesis, development, and removal of vortex cavitation is cyclic. At different levels of cavitation, the degree of pulsation in pump outlet flow, pressure, and radial force increases with increasing cavitation. Periodic vortex cavitation leads to periodic changes in pump output pressure, flow rate, radial force, and axial force.

Physics-Based Modeling to Elucidate Design Principles for Redox-Mediated Electrochemical Systems

Electrochemical systems are increasingly being developed and deployed as sustainable technologies that support reductions in greenhouse gas emissions across the electric power, transportation, and industrial sectors. However, the need to overcome challenges related to cost, performance, and scalability continues to motivate exploration into alternative material sets and reactor designs that offer new pathways to widespread adoption. Redox-mediated processes, which decouple electrode reactions that activate a soluble mediator from “off-electrode” reactions where the activated mediator exchanges electrons with a solid material, are of growing interest.1,2 Recent literature has illustrated the potential of this approach for increasing the charge-storage capacity of redox flow batteries,2 performing impractical electrochemical processes,3 enhancing selectivity and efficiency of electrochemical separations and recycling,1,4,5 and unlocking spatial and temporal flexibility in electrochemical operations.6 Previously, we have developed and qualitatively validated a model capable of capturing key dynamics observed in redox-mediated flow batteries.7 Grounded in first principles and contextualized by experiments, this model has the potential to rapidly assess tradeoffs and opportunities for redox-mediated systems for applications in energy storage and conversion as well as materials recovery and recycling.Here, we describe how our model can be used to gain generalizable insights into the design-space for redox-mediated electrochemical processes. By incorporating models for pressure drop in porous media with simulated electrochemical performance, we assess the trade-offs associated with capacity utilization, power output, and parasitic pumping losses. Furthermore, we demonstrate how the model can support constrained optimization to guide the design of a system of known physical parameters. Ultimately, we seek to translate these findings into universal design principles for how electrochemical protocol and solid incorporation can be tuned to develop high-performing redox-mediated systems. Acknowledgements N.J.M gratefully acknowledges the NSF Graduate Research Fellowship Program under Grant Number 2141064. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF. References Xue et al., Green Chem. 2020, 22 (19): 6288-6309.Yan and Wang, Mat. 2018, 30 (47).Vardner et al., ChemElectroChem 2022, 9 (24).Cotty et al., ACS Sustain Chem Eng. 2023, 11(9):3975-3986.Park et al., ACS Sustain Chem Eng. 2021, 9 (24): 8214-8221.Wang et al, Joule 2021, 5 (1): 149-165.Matteucci et al., ECS Meeting s 2023, MA2023-01 (3), 765.

Comparison between invasive cardiac output and left ventricular assist device flow parameter.

To evaluate the correlation between left ventricular assist device flow parameter and invasive cardiac output measurements. We retrospectively evaluated right heart catheterization examinations performed in left ventricular assist device patients from 2 tertiary medical centres. We evaluated the correlation between cardiac output measurement methods (indirect Fick and thermodilution) and pump flow parameter using linear regression, and the agreement was graphically displayed using Bland-Altman plot technique. Clinical, echocardiographic, pump and haemodynamic parameters were compared between patients with and without discordance, defined as at least a 20% difference between measurements. The study population consisted of 102 patients [median age 58 (51-64), 86% males, 17 ± 12 months post left ventricular assist device implantation] with a total of 544 measurements compared. Discordance between measurements was present in 102 of 226 (45%) comparisons between indirect Fick and pump flow and in 72 of 161 (48%) between thermodilution and pump flow. A comparison of indirect Fick and left ventricular assist device exhibited a statistical correlation of R = 0.751, and that of thermodilution and left ventricular assist device of R = 0.789. Parameters associated with the presence of discordance between cardiac output measurements included a higher rate of aortic valve opening, lower indirect Fick and higher thermodilution cardiac output. After excluding the lowest tertile of indirect Fick cardiac output values, the correlation between measurements improved (thermodilution: R = 0.879 and indirect Fick: R = 0.843, P < 0.001). The current left ventricular assist device flow parameter provides an estimation of cardiac output that correlates well with indirect Fick and exhibits the strongest correlation with thermodilution. This correlation was stronger after excluding lower cardiac output values.

Rancang Bangun Kontrol Pemadam Kebakaran Menggunakan Sensor MQ-2 dan Flame Sensor 5 Channel Berbasis Fuzzy Logic

Fire is an event that often occurs due to human negligence. Losses from fire include damage to goods, business delays and can even cause loss of life. For early handling of fires, a "Fire Fighting Control Design Using MQ-2 Sensor and Fuzzy Logic Based 5 Channel Flame Sensor" has been created. This tool uses the MQ-2 sensor to detect gases related to fires, such as hydrocarbon gas. A 5 channel flame sensor is used to detect flames. The predetermined fuzzy logic rules will be used to control the fire extinguisher and implemented using the Arduino Atmega 2560 microcontroller as the brain of the system. Next, the microcontroller will send a control signal to the 12V DC pump output as a water spray system to deal with fires. The test results of this system show that the tool can detect early fire hotspots and respond well to fire extinguishing according to the fuzzy rule decisions carried out by testing the tool with 30 fire spots at different distances.

Passively mode-locking fiber laser based on Cr2Si2Te6 saturable absorber

This paper reports on the generation of third-order harmonic mode-locking, double-pulse phenomena, and conventional solitons in an erbium-doped fiber laser using Cr2Si2Te6 as a saturable absorber (SA). The double-balance probing method was employed to examine the nonlinear characteristics of Cr2Si2Te6-SA. Its modulation depth is 2.35 %, and its saturation intensity is 29.74 MW/cm2. We discovered conventional soliton functioning with a center wavelength of 1561.8 nm at a pump power of 34.76 mW. It has a repetition frequency of 6.76 MHz and a signal-to-noise ratio of 45 dB. As the pump power increased, the traditional soliton was able to maintain its existence in the range of 34.76 mW to 80.96 mW. The maximum output power reaches 1.1 mW when the pump power is 80.96 mW, and the maximum single-pulse energy of the conventional soliton is 0.16 nJ. Furthermore, we observed third-order harmonic mode-locking and double-pulse phenomena at pump outputs of 53.65 mW and 71.16 mW. The experimental findings demonstrate the excellent nonlinear effect of the SA based on Cr2Si2Te6. In ultrashort-pulse fiber lasers, Cr2Si2Te6 nanosheets can be employed as an efficient saturable absorption material.

Enhancement of Q-Switched Erbium-Doped Fibre Laser Performance using Graphene Oxide-Calcium Oxide Thin Film Saturable Absorbers

This paper presents an experiment utilizing calcium oxide (CaO) from the cuttlefish bone combined with graphene oxide (GO) to create a graphene oxide-calcium oxide (GO-CaO) based saturable absorber (SA) for Q-switched erbium-doped fibre lasers. The experiment aims to investigate the impact of calcium oxide when added to graphene oxide to form the SA thin film. The laser performance of both types of SA was compared, considering their input pump power, repetition rate, pulse width, and output power. The results indicated that the graphene oxide – calcium oxide SA thin film provided the best output power and the lowest threshold input pump power at 10.76 µW and 53.12 mW, respectively. In the characterization, UV-Vis spectroscopy was utilized to determine the number of discrete wavelengths in UV or visible light that the materials absorbed or transmitted. The UV-Vis results indicated that the graphene oxide thin film exhibited an absorbance value of 0.049 AU and a transmittance value of 89.25 % at a wavelength of 1565 nm. In comparison, the GO-CaO SA thin film displayed an absorbance value of 0.037 AU and a transmittance value of 91.89 % at the same wavelength. Raman spectroscopy was also conducted to provide details about the chemical structure and crystallinity of the thin film samples. The results showed high-intensity peaks for the GO thin film at wavenumbers of 1353.74 cm-1 and 1609.85 cm-1, and for GO – CaO thin film at wavenumbers of 1358.56 cm-1 and 1612.18 cm-1. Additionally, SEM was utilized to study the morphology of the thin film samples. Based on the characterization and laser performance results, it was concluded that the addition of calcium oxide to graphene oxide enhances the properties of the SA thin film, leading to improved laser performance due to its higher thermal conductivity.

Aortic insufficiency in the patient on contemporary durable left ventricular assist device support: A state-of-the-art review on preoperative and postoperative assessment and management

The development of aortic insufficiency (AI) during HeartMate 3 durable left ventricular assist device support (dLVAD) can lead to ineffective pump output and recurrent heart failure symptoms. Progression of AI often comingles with the occurrence of other hemodynamic related events encountered during LVAD support, including right heart failure, arrhythmias, and cardiorenal syndrome. While data on AI burdens and clinical impact are still insufficient in patients on HeartMate 3 support, moderate or worse AI occurs in approximately 8% of patients by 1 year and studies suggest AI continues to progress over time and is associated with increased frequency of right heart failure. The first line intervention for AI management is prevention, undertaking surgical intervention on the insufficient valve at the time of dLVAD implant and avoiding excessive device flows and hypertension during long term support. Device speed augmentation may then be undertaken to try and overcome the insufficient lesion, but progression of AI should be anticipated over the long term. Surgical or transcatheter aortic valve interventions may be considered in dLVAD patients with significant persistent AI despite medical management, but neither intervention is without risk. It is imperative that future studies of dLVAD support capture AI in clinical endpoints using uniform assessment and grading of AI severity by individuals trained in AI assessment during dLVAD support.

Research on experiment for operation performance of water pumping and energy storage by photovoltaic pump

In this article, the behaviors of both flow and generated output of photovoltaic pump, the characteristics of both water pumping efficiency and output frequency, and the feature of charge capacity in accumulators have been tested through experiments, based on the integrated application system for water pumping, energy storage and illumination by photovoltaic pump, and in combination with composition and operation performance of photovoltaic water pumping system. According to the experimental results and under a constant delivery head, the photovoltaic pump and accumulator energy storage system with a total measured power of 1.8375 kWp in a photovoltaic array produces a daily water output of 13.1 m3 and an average water output of 1.93 m3/h; the maximum water pumping efficiency of the system is 12.7% and the average water pumping efficiency is 11.1%; meanwhile, the energy storage capacity of accumulators by charging in three time periods throughout a day is 1.01 kWh, which accounts for about 9.72% of the photovoltaic array's all-day generated energy, namely 10.3 kWh. Those conclusions have certain practical implications for the optimal configuration of photovoltaic water pumping system.

Characteristic study of valveless pump with dual outlet composite drainage structures

Abstract Valveless pumps are gaining importance in various fields. However, the reflux phenomenon can reduce pump performance and limit its application. This article proposes a dual outlet composite drainage structure valve-less piezoelectric pump with multiple semicircular arc structures within the flow channel to address this issue. The operating methods are explained, and the pump output flow rate formulation has been derived. The ANSYS CFX was used to simulate flow conditions in various directions. A prototype pump was then produced and tested using 3D printing technology. The results show that the flow rate gets a maximum state of 189.6 mL/min under a voltage of 200 V and a frequency of 50 Hz.

Design of 1450-1500nm Bismuth-doped Fiber Laser

With the rapid development of information technology, people's demand for the transmission capacity of fiber optic communication networks is increasing. How to broaden the bandwidth of communication systems has become one of the key issues in the field of communication. Researchers have found that the operating bandwidth of amplifiers mainly limits the bandwidth of communication systems. Although multiple solutions have been proposed and implemented to address this issue, there are still many gaps in the design of full-band multi wavelength-related light sources. By studying the three-level system of bismuth ions, the rate equation and power transfer equation of a bismuth ion doped fiber laser are simulated, and the pump power threshold and output power are calculated. Using MATLAB for simulation experiments, the relationship between laser power and pump power, as well as their variation with propagation distance, were ultimately obtained. The simulation results show that under 830 pump lights, the pump light threshold power is 10W. After reaching the threshold power, the pump light power and laser power have a linear relationship, and as the propagation distance increases, the pump light power gradually decreases and the laser power gradually increases. The analysis shows that the power generated by the signal light in this band meets the theoretical standards, which verifies the correctness of the scheme.

Design of Fiber Laser Based on Erbium-ion

Erbium ions (Er3+) exhibit good characteristics of fiber lasers in the 1500-1550 nm band, including three-level systems, high tilt efficiency, and large emission cross sections. This article focuses on studying the spectral characteristics of erbium ions, simulating the power propagation equation of erbium-doped ion fiber lasers, and calculating the pump power threshold and output power. The findings of the simulation indicate that the laser begins to produce 10 W of pump optical power. The laser power hits 34.38 W and the oblique power is determined to be 38.20% as soon as the pump power exceeds 100 W. Experimental results show that when pump light propagates forward, the forward propagation power of the pump light will weaken, the forward propagation power of the signal light will increase, the reverse propagation of the signal light will weaken and the reverse propagation of the pump light will Transmission will also weaken, with directional transmission remaining largely unchanged. This study carried out numerical simulations on the experimental parameters of the fiber laser doped with Er3+and finally obtained the output power of pump light and signal light under these conditions, providing better data support for the preparation of 1500-1550 nm fiber laser doped with erbium ion.

A High-Performance piezoelectric micropump designed for precision delivery

A piezoelectric micropump (PE pump) was proposed featuring a multi-plate cantilever valve (MPCV) and a ramp channel (RC) to deliver high performance in a compact design. Both the MPCV and RC underwent thorough theoretical, simulation-based, and experimental evaluations. A specialized driver plate was then developed to precisely control the PE pump. Key parameters of the PE pump were optimized based on test results. The final phase involved assessing the PE pump's output performance through tests, including a simulated insulin infusion scenario. The findings revealed that the MPCV exhibited a pronounced rectification capability, significantly enhancing the pump's operational efficiency over traditional designs. The RC, on the other hand, effectively minimized fluid resistance, capitalizing on the fluid inertia effect for improved performance. Integrating the MPCV and RC aligned the fluid path from inlet to outlet closely parallel to the PE vibrator. This alignment reduced backflow, thereby improving the micropump's output efficiency. Operating at 240 voltage peak-to-peak (Vpp) and 230 Hz, the PE pump demonstrated a flow rate of 6.8 ml/min and an output pressure of 68.6 kPa while maintaining a compact size of merely 10 × 10 × 1.5 mm3. The precision in flow rate adjustment was refined to 0.15 μl, with the deviation in insulin delivery being approximately ± 3 %. The study presents a prototype for a continuous subcutaneous insulin infusion protocol, leveraging the PE pump's advanced features.

Design and Characteristic Research on Variable Displacement Mechanism of Two-Dimensional (2D) Bivariable Pump

In a hydraulic system, a micro variable pump is required to be high pressure and high speed, and this work presents a new type of 2D bivariable pump structure in which the worm gear and worm mechanism are used to rotate the cylinder block to change the flow distribution state of the cylinder window and the piston groove to change the displacement of the 2D pump. The flow–pressure mathematical model of the 2D variable pump is established to analyze the relationship between pump displacement and the pump cylinder rotation angle and the effects of variable displacement on pump pressure characteristics, flow characteristics, and volume efficiency in Matlab. During the experiment, we tested the change in the corresponding pump output flow when the cylinder rotation angle is 0~12°, which verifies the correctness of the variable calculation model. The experimental results indicate that the volume efficiency and mechanical efficiency of the single-piston 2D pump are reduced to different degrees after variable displacement, the volume efficiency is reduced by approximately 3% at most, and the mechanical efficiency is reduced by approximately 5% at most.

Load sensitive control characteristics of a novel two-dimensional pulse width modulated variable mechanism

Load sensing technology is a typical hydraulic technology that automatically meets load requirements by adjusting the pressure and flow at the pump outlet. Traditional load sensitive pump control systems rely on variable mechanisms to achieve such flow control characteristics. However, general variable mechanisms have complex structures and poor dynamic performance if frequently adjusted. Therefore, a new variable mechanism, named two-dimensional pulse width modulation rotary valve, is proposed. Different from the pulse width modulation control method of the electronic technology, the two-dimensional pulse width modulation rotary valve conducts secondary distribution of the quantitative pump output in the way of fluid pulse width modulation: the valve core rotates to generate discrete fluid, and the axial sliding of the valve core controls the duty ratio of the discrete fluid. The dynamic balancing of the axial displacement is controlled by feedback pressure to provide a fixed differential pressure for the control valve, achieving that the flow through the control valve is uniquely controlled by the valve opening of the control valve. The principle of the fluid pulse width modulation is first introduced, and then the mathematical model of the proposed variable mechanism and the corresponding system is established. Simulation analysis is implemented. Finally, the effectiveness of the load sensing system controlled by a two-dimensional pulse width modulation rotary valve is verified by the experiment.

Analysis of Plasma Dynamics in He-Ne Lasers with Different Gas Ratios

He-Ne lasers play a crucial role in ultra-precision measurement and optical sensing across various fields. For many applications based on He-Ne lasers, a higher output power is required to enhance the accuracy and signal-to-noise ratios of the associated optical measurements. However, conventional methods to increase the output power by reducing the diameter of the He-Ne laser discharge capillary inevitably result in higher diffraction losses and constrain the lasing performance. Here, we propose an approach to enhance laser pumping efficiency and output power through optimizing the ratios of He and Ne gasses. The validity of our proposal has been confirmed by both numerical simulations of He-Ne laser plasma discharge processes and experimental demonstrations, showing that the optimal gas ratio increases with the capillary diameter and total gas pressure.

Влияние гидроабразивного износа форсунок на производительность струйного насоса

A finite-elemental model of a jet pump was created. The pump consisted of a case, in which there were eight jets, situated in a circle, symmetrically relative to the circle axis, on the equal distance of each other around the outlet of a pipeline, along which the pulp was pumped. The basic element size of the net in creating the model amounts to 50 mm, whereas the net elements size was diminished in the region of jets. The numerical experiment was carried out in order to evaluate the influence of the jets hydroabrasive wear parameters on the pump output. In conducting the computations, the assumptions were as follows: the liquid columns in the suction and force-feed pipelines were neglected; there was pure water modelled in the suction pipeline instead of the pulp taking into account that the concentration of the sand in the pulp does not exceed 10% by volume. The computations were realized in the stationary formulation of the problem. As basic parameters of the hydroabrasive wear of the jets the following were chosen: the angle of the skew of the jet forward end; a jet shortening – the displacement of the jet forward end center along the jet axis. As a result of the numerical experiment the body of data was obtained. Using the least squares method to process the data, the second order model was created, describing the dependence of the pump output on the jets wear parameters. The analysis of the model showed that the change of the angle of the forward end skew of the jets has a weak influence on the output of the pump, whereas the shortening of the jets by each millimeter causes the decrease of 1% to the nominal value of the pump output.

IoT fire detector with Telegram notification

Fire is a disaster whose arrival cannot be predicted or can occur at anytime and anywhere. The impact is in the form of material loss and loss of life, therefore, there is a need for early detection and early prevention of fire. Technological advances that can be used in early detection efforts are the Internet of Things (IoT). IoT can connect electronic devices that can connect via the internet so that they can quickly provide data and information. Fire incidents can occur in public places or in residential areas. Therefore, a tool was created which aims to be able to design and monitor a fire extinguishing system using telegram via NRF24L01, phototransistor sensor and MQ2 smoke sensor with relay driver output and DC pump via Arduino as well as LCD, buzzer and ESP2866. The fire extinguishing system method uses telegram via NRF24L01, phototransistor sensor and MQ2 smoke sensor with relay driver output and DC pump via Arduino. As well as LCD, buzzer and ESP2866 activated via Wi-Fi using condition output from the phototransistor sensor and MQ2 smoke sensor via NRF24L01 in the form of real-time data which is active and if the NRF24L01 receives data it will activate the relay driver to turn on and off the dc pump and buzzer, after which the data is sent to the Telegram application. After testing and analyzing the fire extinguishing system, it can be concluded that the fire extinguishing system has been able to work properly.

From sucking worms to Windkessel: The physics of an early eighteenth century firefighting device

We describe the physics of the “Windkessel effect” and its role in smoothing the output of water produced by piston-driven pumps found in early fire engines and modern residential well houses. We also construct a simple, analytical model of its operation and apply this model to the Windkessel in Richard Newsham's 1725 fire engine. We find that Newsham's Windkessel reduces the variations in the pump output stream from a high of 80% to a low of 16%.

НАБЛЮДАТЕЛЬ ДАВЛЕНИЯ НАСОСНОЙ УСТАНОВКИ С АСИНХРОННЫМ ЭЛЕКТРОПРИВОДОМ

Relevance The synthesis of a liquid pressure observer for a pumping unit with an asynchronous electric drive is considered. This type of electric drives with a centrifugal pump is widely used in agriculture and housing and communal services, industry, and transport, which indicates its relevance. This electrical engineering complex includes a source of electric energy, an electric motor, a pump as an executive body and a technological object. The use of closed feedback in adjustable electric drives of pumping units for monitoring liquid pressure leads to the need to determine this coordinate. This task can be accomplished by using indirect pressure estimates using the Luenberger observer, based on information obtained from current and voltage sensors of the asynchronous electric drive. Aim of research The main aim of the research perform a synthesis of a pressure observer for a pumping unit with an asynchronous electric drive. Research methods The Luenberger observer was used to identify the pressure. The performance of the synthesized observer was tested using simulation models of the electric drive and the observer in the Simintech environment. Results A pressure observer for the electric drive of a pumping unit has been developed. A simulation model of the electric drive of a pumping unit and a pressure observer has been developed in the Simintech environment, allowing the pump output coordinates to be estimated in transient modes. A comparison has been made of the estimated pressure value obtained using the synthesized observer with the transient process curves of the reference pressure, with changes in the value and frequency of the stator voltage, as well as the hydraulic resistance of the pressure pipeline. As a result of the work performed, it has become possible to determine the pump pressure based on the values of the stator current and voltage in dynamics.