Single Pump Research Articles

Theoretical study on the leakage characteristics of Disc-Seal Single Screw Pump used in oily sludge waste heat source absorption refrigeration system

The disc-seal single screw pump (DSSP) used in the field of oily sludge transport has a huge advantage. However, there is no research on the leakage characteristics of the DSSP at present, which makes its application limited. Therefore, the mathematical calculation model of leakage amount of each leakage channel was established in this paper according to the geometric model of the leakage channel. By using this mathematical model, the influence rule of working parameters on the leakage characteristics was analyzed. The results show that the total leakage amount per unit time of the DSSP varies periodically with the rotation of the screw, and the total leakage per unit time of the DSSP will increase with the increase of outlet pressure and screw rotation velocity. When the dynamic viscosity coefficient of the medium increases, the corresponding leakage will be reduced, in which the transmission medium dynamic viscosity is the main factor affecting the total leakage of the DSSP. The study of the leakage characteristics of the DSSP can provide a theoretical basis for the optimal design of its structure in the future.

Research on Parallel Operation Characteristics of High-pressure Pumps Applied in Coal Mine Hydraulics permeability improvement

Nowadays, plunger high-pressure water pumps applied in large-scale mine are mostly used in coal mine hydraulics to increase permeability, and it is difficult to transport objections underground. Besides, the permeability improvement is affected during overhaul too. Therefore, multiple small high-pressure water pumps operating in parallel can be used to solve the problems mentioned above instead of large high-pressure water pumps. Moreover, the operating principle of the plunger high-pressure pump determines the specific flow fluctuation characteristics during its operation, and similar flow fluctuations also exist during the operating of parallel pump sets. The transmission model and AMESim hydraulic simulation model of single, parallel plunger pumps are established, taking the BQW-22/50 high-pressure water pump as an example. The operating characteristics of a single plunger pump and a parallel pump group are analyzed in this paper. The results are obtained as follows: the instantaneous discharge flow curve of a single plunger pump conforms to a sine function; the flow of the parallel pump set is the superposition of the flow of multiple plunger pumps; the instantaneous discharge flow curve changes under the influence of the phase deviation angle between the pumps; when parallel pump sets are running, there is an optimal phase deflection angle between the pumps, which minimizes the flow fluctuation of the pump sets; when four high-pressure water pumps are operated in parallel, the optimal phase deflection angle between the pumps is π/12 or π/4.

Ultra-clean radon-free four cylinder magnetically-coupled piston pump

A high performance gas displacement pump based on four individual cylinders was developed. The magnetically-coupled pistons and the hermetically-sealed housings as well as the special cleanliness in terms of out-gassing and radio-purity make the four cylinder pump interesting for the usage in low background experiments dealing with noble gases as target. An optimized inner flow path as well as reduced dead volume with respect to the prototype single cylinder pump of the XENON1T experiment combined with advanced polymer piston gaskets and a piston coupling force of (3177 ± 162) N ensures a high and reliable performance. Furthermore, a phase-shifted synchronization of the pistons' movement creates an additional performance boost as well as minimizes fluctuations of flow and compression. The pump is able to generate xenon flows of 474 slpm with a pressure difference of 1.80 bar at an inlet pressure of 2.1 bar.

Defect characterization in floating body transistors using a single pulse charge pumping method

Field-effect transistors on a floating body channel have been used for a range of applications, such as three-dimensional nand flash and high-performance devices on silicon-on-insulator wafers. Conventional techniques to characterize the defect states cannot be implemented because those transistors do not have body contacts. A single-pulse charge pumping (SPCP) method was introduced to characterize the defect state distribution of the floating body transistors. The results extracted from the SPCP method on the three-terminal transistors (without body contact) agreed well with those from a conventional charge pumping method or SPCP on four-terminal transistors (with body contact). The validity of the SPCP measurement of the floating body devices was demonstrated by monitoring the increase in the defect state of the three-terminal poly-Si transistors density during the bias stress test. The SPCP method could detect the defect states of floating body transistors with high resolution.

Operation Cycle of Diesel CR Injection Pump via Pressure Measurement in Piston Working Chamber

The paper is devoted to the analysis of the operating cycle of a high-pressure injection pump used in common rail systems. The investigation is based on experimental activities, and it is carried out in a novel pump set-up that allows measurements of the instantaneous pressure in the piston working chamber. A single plunger pump has been equipped with a piezo-resistive pressure transducer which allows for the measurement of the pressure signal during pump operation on a test rig. The paper describes the experimental set-up, the modified injection pump equipped with the pressure transducer, and the experimental tests carried out. Main results obtained using a standard commercial diesel fuel are discussed at first; secondly, the focus moves on to the use of an alternative fuel (biodiesel) whose features in terms of bulk modulus, viscosity, and density significantly differ from the reference fuel. Based on the characteristics of the pump operating cycle, the fuel suction and delivery processes are analyzed, pointing out how the used fuel type is reflected on them. The investigations are aimed at describing the operating characteristics of the pump, focusing the attention on those features playing a fundamental role on the global efficiency of the pump. The amplitudes of the pump-work phases, the ranges of pressure fluctuations, and the pressure-rise rates are quantified and reported, providing crucial indications for lumped parameter modeling and design activities in the field of current generation high-pressure injection pumps.

​Weed Control using Pre-emergence Herbicide Strip Application System Along with Sowing/Planting Devices

A 6-row pre-emergence herbicide strip-application system was designed and developed at ICAR-CIAE, Bhopal as an attachment to inclined-plate planter to apply herbicide at the time of sowing in widely spaced crops to control weeds along the crop rows, often not possible in mechanical weeding. It consisted of a frame on which 6 flat fan spray nozzles were mounted by means of clamps, a single action piston pump with 9 l/min capacity, pressure regulator valve and pressure gauge and pressure pipes. The spacing between the spray nozzles, angle and height of spray nozzles can be varied by adjusting the clamps. The developed system has ability of strip as well as blanket application of herbicide. The same machine can be used as post-emergence herbicide/pesticide applicator after the removal of furrow openers and increasing the height of nozzles from the ground. The machine was tested and evaluated during Kharif season for soybean and pigeon pea crops. The field capacity of the developed system was found to be 0.4 ha/h. The operating cost of the pre-emergence herbicide applicator with inclined plate planter was worked out as Rs 1350/- per ha. It can save about 40-50% herbicide.

Low Power, Wide Range Synthesizer for 534 MHz–18.56 GHz Band with FoM of − 192.45 dBc/Hz

A wide range frequency synthesizer is designed with the help of dual voltage tunable Differential Ring Oscillator (DRO). Frequency ranging from 534[Formula: see text]MHz to 18.56[Formula: see text]GHz can be generated using the proposed synthesizer. As proposed circuit utilizes dual voltage tunable DRO, a select input is provided to control the output frequency range. Logic low value (0[Formula: see text]V) of select input generates frequencies from 534[Formula: see text]MHz to 5.08[Formula: see text]GHz whereas logic high value (1.1[Formula: see text]V) of select input enables the frequency generation in the range of 5.08[Formula: see text]GHz to 18.56[Formula: see text]GHz. This work utilizes a single charge pump and single loop filter along with charge pump and bias control circuit. Proposed circuit is designed in GPDK 45-nm CMOS technology with supply voltage of 1.1[Formula: see text]V. Power consumption of the proposed circuits is 2.88[Formula: see text]mW while generating frequency of 7.84[Formula: see text]GHz. Proposed synthesizer demonstrates Figure of Merit (FoM2) of [Formula: see text][Formula: see text]dBc/Hz at this frequency. Because of such a wide spectrum, this synthesizer is well suited in the field of satellite communication, GPS and navigation.

Modeling of flow coastdown transient of a reactor coolant system under different pump failures

The flow coastdown transient calculation is important for the safety analysis of a nuclear reactor. An accurate transient analysis during coastdown is necessary and important for the design and manufacture of a reactor coolant pump, since only the reliable work of reactor coolant pumps can guarantee the safety of a nuclear power plant during this important period.In the present work, mathematical models are solved for the non-dimensional transient flow rates in four loops and a reactor core under different power failures of reactor coolant pumps. Python 3.6, high level programming language, is used to solve the mathematical equations of core thermal-hydraulics for the flow coastdown transient. A standard 4-Loop Westinghouse design pressurized water reactor is used in the analysis. Three cases are studied; failure of one of the four pumps, sequential failure of the four pumps and simultaneous failure of the four pumps due to loss of off-site power. The important parameters for the safety analysis of the reactor are flow coastdown time, flow rates, and coolant temperature. The model results for a single pump failure are compared with the published experimental data during flow coastdown of Qinshan reactor coolant pump. The comparison results show acceptable agreements. Sensitivity analyses for two different parameters during flow coastdown transient are investigated. These two parameters are the fluid inertia ratio, α and core time constant, τ. Effects of each of the parameters on the flow coastdown transient, are given separately.

Time-domain Fabry–Perot resonators formed inside a dispersive medium

We show that the temporal analog of a Fabry–Perot resonator (FPR) can be realized by using two moving temporal boundaries, formed by intense pump pulses inside a dispersive medium (such as an optical fiber). We analyze such FPRs using a transfer-matrix method, similar to that used for spatial structures containing multiple thin films. We consider a temporal slab formed using a single square-shape pump pulse and find that the resonance of such an FPR has transmission peaks whose quality ( Q ) factors decrease rapidly with an increasing velocity difference between the pump and probe pulses. We propose an improved design by using two pump pulses. We apply our transfer-matrix method to this design and show considerable improvement in the Q factors of various peaks. We also show that such FPRs can be realized in practice by using two short pump pulses that propagate as solitons inside a fiber. We verified the results of the transfer-matrix method by directly solving the pulse propagation equation with the split-step Fourier method.

ELSO Interim Guidelines for Venoarterial Extracorporeal Membrane Oxygenation in Adult Cardiac Patients.

ELSO Interim Guidelines for Venoarterial Extracorporeal Membrane Oxygenation in Adult Cardiac Patients.

Directly accessing octave-spanning dissipative Kerr soliton frequency combs in an AlN microresonator

Self-referenced dissipative Kerr solitons (DKSs) based on optical microresonators offer prominent characteristics allowing for various applications from precision measurement to astronomical spectrometer calibration. To date, direct octave-spanning DKS generation has been achieved only in ultrahigh-Q silicon nitride microresonators under optimized laser tuning speed or bi-directional tuning. Here we propose a simple method to easily access the octave-spanning DKS in an aluminum nitride (AlN) microresonator. In the design, two modes that belong to different families but with the same polarization are nearly degenerate and act as a pump and an auxiliary resonance, respectively. The presence of the auxiliary resonance can balance the thermal dragging effect, crucially simplifying the DKS generation with a single pump and leading to an enhanced soliton access window. We experimentally demonstrate the long-lived DKS operation with a record single-soliton step (10.4 GHz or 83 pm) and an octave-spanning bandwidth (1100–2300 nm) through adiabatic pump tuning. Our scheme also allows for direct creation of the DKS state with high probability and without elaborate wavelength or power schemes being required to stabilize the soliton behavior.

RANCANG BANGUN AUTOMATIC HAND WASHING STATION DENGAN MENGGUNAKAN MIKROKONTROLLLER ARDUINO UNO R3

Washbasin needs to be provided in a place that is generally visited by people. It is necessary to design an automatic hand washing machine to reduce direct contact. This study aims to design and manufacture a simple automatic hand washing device, using a microcontroller and equipped with sensors to regulate the faucets and also regulate the release of the soap dish. This research has 3 stages. The first stage of planning includes the selection of actuators, sensors, and microcontrollers. Second, the manufacture of tools in the form of mechanical manufacture, electrical circuits, and programming. The final stage is testing, responding to tools that will function properly, and monitoring those that still need to be developed. Based on the research, the Automatic Hand Washing Station design tool uses a frame in the form of steel angles with holes SA75 3.75 x 3.75 with binders in the form of Hex Bolt and Nut M10, Arduino Uno R3 Microcontroller, Relay Module, Buck Converter, 2 Infrared Sensors, 5 LEDs, the actuators used are Single pump DC 12V 4.5A, servo motor 9.4 kgf.cm, reservoir with a capacity of 19 liters, and Power Adapter 12V 5A. The electronic system affects the performance of the actuator which results in the less functioning of the actuator itself. This connected obstacle is caused by the condition of the jumper cables that accumulate and also the less than the optimal output power. The programming system uses the Arduino IDE and can run well in the simulation tool process.

Model based optimization of a novel ventricular assist device

Abstract This paper presents an optimization-based control scheme for a novel left ventricular assist device. This cardiac support system consists of two pumps connected in series and a buffer reservoir in between them. This novel concept for relieving the left ventricle is designed to allow the pre- and afterload on the heart to be explicitly adjusted and independently of each other. The first pump controls the preload of the heart with a known physiological controller. With an iterative model-based optimization, the afterload is minimized by the second pump while complying with all constraints. The proof of the control concept and a comparison to the classical single pump left-sided cardiac support is performed on a hardware-in-the-loop test bench. The results show that with the new left ventricular assist device concept, the afterload can be reduced compared to the classical cardiac support.

Rituximab with Dose-Adjusted EPOCH (R-DA-EPOCH) As First-Line Treatment in Patients with Double-Hit Lymphoma: Preliminary Results in 35 Consecutive Patients from Two Institutions

▪Introduction: Patients with aggressive B cell lymphomas carrying concomitant c-Myc and Bcl-2 and/or Bcl-6 gene rearrangement (DHL/THL) have a poor outcome when treated with standard R-CHOP regimen. Better results were reported in patients treated with more intensive programs, currently used in highly proliferative diseases such as Burkitt lymphoma. In particular, R-DA-EPOCH obtained the best result in a retrospective study comparing different intensive regimens (Oki et al. BJH 2014). We report the experience with this program of two hematologic centres in Northern Italy in patients with dysregulation of c-Myc gene associated with Bcl-2 and/or Bcl-6 abnormalities.Methods: From January 2014, all consecutive fit patients aged less than 80 years, with diffuse large B cell lymphoma (DLBCL) or lymphoma with intermediate features between DLBCL and Burkitt (BCLU), including 10 patients with histological features suggesting transformation from follicular lymphoma, and showing DHL or THL by fluorescent in situ hybridization (FISH), were treated with R-DA-EPOCH and central nervous system prophylaxis with intrathecal methotrexate +/- cytarabine . Patients with c-Myc amplification (more than 4 signals) plus Bcl-2 and/or Bcl-6 gene rearrangement or amplification were also included (AMPL). Pre-treatment with one cycle of R-CHOP was allowed in patients in need of urgent treatment, pending the results of FISH analysis. Autologous stem cell transplantation (ASCT) was planned in one of the two centres for patients who reached at least a partial remission after six R-DA-EPOCH courses. Cell of origin (COO) was defined by immunohistochemistry (IHC) according to Hans's algorithm.Results: Thirty-five patients (30 DLBCL and 5 BCLU) were treated. They received a median of 6 courses of R-DA-EPOCH (range 1-6) administered either to inpatients or to outpatients using a single portable infusion pump. Six patients were pre-treated with R-CHOP and 10 patients received consolidation with ASCT. According to FISH analysis, 18 cases were DHL, 6 THL and 11 AMPL. The median age of the whole group was 63 years (range 34-79). Twenty-nine patients were male (83%). Thirty-two patients (91%) had Ann-Arbor stage III/IV and 25 (71%) had high-intermediate/high risk score according to International Prognostic Index (IPI), with extranodal presentation in 74%, mainly in bone and gastrointestinal tract. According to Hans's algorithm, 85% of patients were of germinal center COO. By IHC double expression of myc (>40%) and of bcl-2 protein (>50%) was reported in 75% of patients. Median lymphoma cells proliferation fraction assessed by Ki-67 IHC was 80% (range 35-100%). Three patients died of infectious complications during chemotherapy. The overall response rate for the entire cohort was 71%. Of seven refractory patients, five have died of lymphoma, one is disease free after allogeneic transplantation and one is still on treatment. Among 25 patients who achieved a response to front-line therapy, one died of suicide and 24 are still in remission after a median of 15 months. The 1-year PFS and OS rates were 69% and 73%, respectively. There was no significant association of PFS or OS with age, COO, type of histology, transformation from FL, extranodal involvement, Ki-67. THL had significant worse survival comparing to DHL and AMPL (20% vs 88% vs 68% p 0.03) (Fig.1).Conclusions: These results confirm R-DA-EPOCH as a feasible program in unselected fit patients up to the age of 80. Short-term efficacy was high, considering the poor prognosis of double or triple-hit aggressive B-cell lymphoma. Few data are available to define the role of consolidative ASCT and its utility is still unclear. Treatment response seems to favourably impact on patient survival. A longer follow-up on larger number of patients is ongoing to confirm these promising results. [Display omitted] DisclosuresCorradini:Takeda: Honoraria; Sanofi: Honoraria; Novartis: Honoraria; Roche: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Gilead: Honoraria. Rossi:Teva: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees.

Influence of Flow Divider on Overall Efficiency of a Hydrostatic Drivetrain of a Skid-Steer All-Wheel Drive Multiple-Axle Vehicle

The efficiency of a skid-steer, all-wheel drive, multiple-axle vehicle with a hydrostatic drivetrain equipped with low-speed motors when it operates on soft terrain was studied. A flow divider enables a single pump to simultaneously power more than one motor circuit with different pressures in each. It prevents kinematic discrepancy and improves vehicle mobility. There are two types of flow divider: spool type and gear type, where each type has its own set of performance characteristics, such as flow range, pressure drop, accuracy and application parameters. In the present work, the influence of the characteristics of both types of flow divider on overall vehicle driveline efficacy is described.

A New Method for Optimization of Water Distribution Networks While Considering Accidents

Optimization of water distribution networks can effectively reduce their annual cost, which includes the average investment for each year the operational costs and depreciation costs. However, the existing optimization models rarely directly consider the basic flow of each node in case of accidents, such as pipe bursts. Therefore, it is necessary to check the flow requirements under accident conditions. In order to deal with these drawbacks, two optimization models are established considering accident conditions: a single-objective optimization model considering annual cost as an economic objective, and a multi-objective optimization model with a reliability objective defined by the surplus water head. These models are solved based on the genetic algorithm, non-dominated sorting genetic algorithm-II algorithm and Levenberg-Marquardt iterative method. Applying two cases of a single pump station and a multi pump water station water supply, it is shown that the annual cost when considering the accident conditions is higher than that without considering the accident conditions. Moreover, the annual cost obtained with the multi-objective optimization model is slightly higher than that obtained with the single-objective optimization model. The cost is higher because the former model reduces the average surplus water head, which can improve the water distribution network reliability. Therefore, the model and optimization algorithm proposed in this paper can provide a general and fast optimization tool for water distribution network optimization.

Parameter estimation based robust liquid level control of quadruple tank system — Second order sliding mode approach

This article proposes a liquid level control scheme for a quadruple tank process (QTP) plant. A robust control is proposed using higher order sliding mode (HOSM) control. The four tank setup has opposite tanks actuated by a single pump and unmeasured liquid outflow from upper tanks affecting the levels in the lower tanks. This renders nonlinearity in the dynamics with uncertain behavior. A novel experimentation based estimator is proposed for identification of the unknown control valve ratios of the plant. The estimated parameter is used for robust control design and state observer model. The unmeasurable states are estimated using a sliding mode observer and the required derivatives of liquid levels in the tanks are evaluated using a HOSM differentiator. The complete schema is tested in simulation and validated experimentally on a QTP setup.

Numerical flow simulation of pump stability for pumped storage units with analysis and visualization of the dynamic flow patterns

With the increasing participation of alternative energy conversion sources in the energy market, the demand for energy storage and grid regulation services keep steadily growing. Pumped storage stations stand out currently as the most suitable and effective solution for these purposes. This leads to tougher requirements regarding the operation flexibility, regulation band and operating range of pumped storage units with reversible pump-turbines or ternary sets (with single or multi-stage pumps), operating at fixed or variable speed. Through the extension of the pump stable region, the pump regulation band can be extended (assuming the proper cavitation safety is provided) and in the case of reversible units the design of the hydraulic machine for turbine mode operation can be accordingly adjusted. The objective here is to model and examine details of the flow phenomena occurring as the pump goes through the unstable region at flows below minimum operating flow. A detailed understanding of the flow phenomena in this region can provide insights to improve the hydraulic design and extend the stable region of operation. Traditional model tests only provide data about the pump characteristic curve. The focus here will be transient computational fluid dynamic (CFD) simulations of a pump-turbine as it goes through the unstable low flow pumping region. The finite volume model includes the complete hydraulic machine from draft tube to spiral case and hybrid turbulence models were used, in this case scale adaptive simulation (SAS). For the analysis and assessment of the transient fluid flow at the different pump operating conditions, integral quantities such as the lift head were evaluated, the velocity field was visualized with flow streamlines, the pressure field with contour plots at the hydraulic surfaces and the vortical structures were identified, quantified and plotted using the criterion. The transient fluid flow calculation was started at an operating point in the pump stable operating range. The simulated pump flow was progressively reduced during the given numerical simulation until the set-in of the pump instability with the break-down of the lift head and pump flow continued to be reduced until the lift head started rising again. The numerical simulations were carried out for a low specific-speed reversible pump-turbine. Detailed model test results were available for the selected design and have been used to validate the numerical simulations.

Experimental study on the influence of inlet distortion on the performance of single suction centrifugal pump

As a renewable energy source, water energy is indispensable in hydropower generation, and centrifugal pump is widely used in hydroelectric generation. But the centrifugal pump usually uses elbow pipe inflow due to the limitation of installation space, and the inflow distortion will lead to the decrease of pump performance and the increase of vibration. In this paper, the influence rule of inflow distortion on external characteristics and pressure pulsation of centrifugal pump was analyzed. The research results show that the inflow of elbow pipe will lead to the decrease of the head and efficiency of the centrifugal pump, which will decrease by 0.68m and 1.5% at the maximum under the design condition. The increase of bend angle will increase the pressure pulsation at the inlet of the centrifugal pump, which has an influence on the pressure pulsation around the volute at different positions, especially the pressure pulsation intensity at the tongue position significantly increases. The research in this paper can provide reference for the design and safe operation of inlet pipeline in practical engineering.

Assessment of the VAD – Native ventricle pumping system by an equivalent pump: A computational model based procedure

ObjectivesTo assess the interaction between a continuous flow pump (CFP) and the native ventricle (NV) when both pumps are giving a flow contribution. Methods and resultsThe pumping system, composed of NV and of CFP, is replaced by an equivalent pump (EP) with the same NV filling characteristics and heart rate. It is assumed that EP cardiac output is equal to the sum of NV and CFP flows and that its Emax is correlated to the CFP pump speed. Both the pumping system and EP are addressed with a closed loop lumped parameters cardiovascular model connected to a Heart Mate II (HM-II) CFP.The experiments were performed to:1: verify EP Emax correlation with CFP speed. Resulting correlation:∼0.98;2: verify EP parameters calculation accuracy, in comparison with the pumping system parameters for different values of peripheral resistance, Emax_NV, HR and CFP speed (8000–11000 RPM). Resulting average error: less than 4%;3: show how EP can be used to obtain the desired haemodynamic or energetic conditions, then feeding the results into the pumping system, so as to regulate CFP speed accordingly. ConclusionsEP merges the properties of the pumping system composed of NV and CFP into a single pulsatile pump. The described methodology can be a useful support to optimise both haemodynamic and energetic variables in the pumping system when, with the simultaneous presence of CFP and NV flows, flow distribution between the two pumps becomes a critical issue.