Test Loop Research Articles

Slurry Transportation Characteristics of Potash Mine Cemented Paste Backfills via Loop Test Processing

This study evaluated the properties and processing of cemented paste backfills (CPBs) for potash mining through loop tests. The CPBs were made with steel slags as the binder, granulated potash tailings as the aggregate, and waste brine water as the liquid phase. The effects of solid concentration and steel slag dosage on the transport and mechanical properties of CPBs were assessed. The loop test demonstrated that all CPB slurries performed well, exhibiting strong long-distance pipeline transport capabilities. The 28-day compressive strength of the backfills exceeded 1 MPa, meeting the design requirements for backfill strength. The key rheological parameters, including yield stress (τ0) and viscosity coefficient (η), were comprehensively and theoretically analyzed based on the variations in pressure loss per unit distance of the filling slurry measured during the loop test. The empirical formulas for CPB pressure loss, accounting for varying flow rates and pipeline diameters, were derived with an error margin under 2%. The response surface analysis showed that the affecting extents of factors on pressure loss in CPB slurry were ranked as follows: solid concentration > cementing agent content > flow rate. This study offered valuable guidance for the processing of potash mine backfill operations.

Testing loop quantum gravity by quasi-periodic oscillations: rotating blackholes

We investigate a compelling model of a rotating black hole that is deformed by the effects of loop quantum gravity (LQG). We present a simplified metric and explore two distinct geometries: one in which the masses of the black hole and white hole are equal, and another in which they differ. Our analysis yields the radius of the innermost stable circular orbits (ISCO), as well as the energy and angular momentum of a particle within this framework. Additionally, we find the frequency of the first-order resonance separately. We constrain the model by the quasi-periodic oscillations (QPO) of the X-ray binary GRO J1655-40. We show that λ=0.15-0.14+0.23 at 1σ confidence level for equal mass black hole and white hole geometry. For the other geometry we get λ=0.11-0.07+0.07 at 1σ confidence level. We encounter a degeneracy in the parameter space that hinders our ability to constrain λ with greater precision.

HIL Test Verification of PDPI Control of Induction Generator‐Based Multi‐Rotor Wind Turbine Systems

ABSTRACTIn this experimental study, a new technique is designed and presented for controlling the rotor side converter of an induction generator (IG) for multi‐rotor wind turbine (MRWT) systems. The direct power command (DPC) strategy is used to regulate the reactive and active power (Qs and Ps). DPC is characterized by several drawbacks, the most prominent of which are low durability, low current/power quality, and the use of power estimation. Therefore, a new PDPI (proportional‐derivative proportional‐integral) regulator is used as a suitable solution to overcome these shortcomings while maintaining simplicity, achieving a rapid dynamic response, and obtaining gains that characterize the DPC. The suggested DPC for controlling the IG inverter of an MRWT system uses two PDPI regulators and pulse width modulation (PWM) to create and generate the pulses necessary to run and regulate the IG inverter. First, the DPC‐PDPI‐PWM is verified in a MATLAB using different tests, and the characteristics of the DPC‐PDPI‐PWM is compared to that of DPC under different working conditions for a 1500 kW IG. Second, the validity of the simulated results is verified using the Hardware‐in‐the loop (HIL) test for the DPC‐PDPI‐PWM, and dSPACE 1104 is used for this purpose. The results demonstrate the effectiveness of the DPC‐PDPI‐PWM approach over DPC, as the harmonic distortion of the stream is minimized by 36.66%, 22.68%, and 33.33% in the three proposed tests. Also, the overshoot value of Ps was reduced compared to DPC by ratios estimated at 70.96%, 71.42%, and 70.31% in all tests. DPC‐PDPI‐PWM also reduces the steady‐state error of Qs compared to DPC by 68.33%, 58.82%, 67.90% in all tests performed. The experimental results confirm the numerical results, suggesting that the DPC‐PDPI‐PWM is a suitable solution in the field of command in the future.

Case Study: Modifying a Desander Design To Handle Low Flow Rates

The Challenge A major North Sea operator had faced issues with sand filling up the production separator on a late-life well on the Norwegian Continental Shelf. The well was previously shut in due to sand production. A jetting operation was required, with solids to be separated on the water line upstream of the reinjection pumps in order to protect the pumps from erosion damage. The expected solids sizes were fines of 20–150 microns and sand in the 150–800-micron range. Flow rate was estimated at a rate of 240 m3/day. The service provider, Expro, was the main contractor and requested assistance from FourPhase to supply the desanding solution. The Solution When presented with the operational data, the project team immediately understood that the low flow rate would be one of our main challenges. The given rate was in the lower end of the capacity window for our DualFlow cyclone designs. Low inflow pressure causes lower differential pressure in the cyclones, resulting in reduced separation efficiency that we were keen to avoid. Throughout more than 10 years of operation, we have built a solids management database, recording all parameters and separation rates during more than 150,000 operational hours. Where we previously relied on extensive computer simulations with computational fluid dynamics modeling, our database now allows us to calculate the sweet spots of solids separation from existing well parameters without any further expensive and time-consuming modeling. This benefits our customers, as our data increases our ability to quickly determine if a given scenario will work or not. In the described case, our database would serve us well in understanding how we could solve the customer's challenge. Plugging the flow data into a calculation tool coupled to the solids database, we calculated which range of differential pressures we could expect in the cyclones. Another calculation tool projected the separation efficiency of solids as a function of pressure conditions. We quickly found that our regular cyclone design with 100-mm-diameter liners were too large, creating a pressure drop that was not beneficial for separation efficiency. Experience, along with calculations based on database figures drawn from previous operations with low flow rates, pointed toward a smaller cyclone liner insert. We had previously manufactured reduced-size liner inserts to meet separation requirements on operations with lower flow rates. Now, we started to consider even smaller-sized inserts. Our calculations showed that a 50-mm-diameter liner insert would provide the best results under the given circumstances (Fig. 1). Seeking internal quality assurance, the project team aligned with our engineering and operations departments, verifying the calculations. The engineering department then quickly got to work creating 3D-printed prototypes for testing. FourPhase has developed and installed a complete test facility at our headquarters in Bergen, Norway (Fig. 2). The test loop gives us an opportunity to test a variety of equipment in a controlled and safe environment.

Compliance of a Tertiary Centre With Molecular Testing Strategies for Lynch Syndrome in Colorectal Cancer.

Introduction Lynch syndrome is one of the most common hereditary cancers associated with germline alterations of DNA mismatch repair genes. Recent advances have shed light on its molecular pathogenesis, leading to the development of various testing strategies. The aim of this study is to evaluate whether all colorectal adenocarcinomas undergo immunohistochemistry (IHC) and microsatellite instability (MSI) testing to identify potential Lynch syndrome patients. Methods This study evaluated the compliance of MSI and IHC testing for Lynch syndrome in a tertiary cancer research centre. All patients undergoing colorectal cancer resectionbetween April 2022 and December 2022were identified from a prospectively maintained register. The histology, MSI, and IHC testing reports for these patients were recorded to check if they were done and reported. Only patients with colorectal adenocarcinoma were included in this study. Results A total of 314 patients had colorectal cancer resections. A total of 301 were included in the study, with a median age of 65 years (IQR = 35-95). Thirteen (4.14%) patients did not have MSI and IHC testing reported on the system. Of these, eight (61.53%) did not have an MSI/IHC testing request, four (30.76%) did not have sufficient specimens to be sent for further testing, one (7.69%) had MSI and IHC testing but the final report was yet to be authorized. Out of the eight who did not have the testing done, three had early polyp cancer and one had a goblet cell adenocarcinoma. Conclusion According to the data, our hospital has a 97.45% compliance with current guidelines, not considering the insufficient sample for testing and the authorization of the final report. A more comprehensive proforma may be needed to provide a feedback loop for further MSI and IHC testing when entering data into the system. Further auditing is required to check the effectiveness of the proforma in achieving complete compliance.

Experimental and theoretical research on upper plenum entrainment with air-water and steam-water

Upper plenum entrainment phenomenon occurs in the automatic depressurization process during the Small Break Loss of Coolant Accident (SBLOCA) in reactor pressure vessel, which may result in reactor disaster. The upper plenum entrainment experiments with and without reactor internals were carried out with air-water and steam-water as working mediums on the Automatic Depressurization and Entrainment Test Loop for Upper plenum entrainment (ADETEL-U) which scaled after AP1000 nuclear reactor. The experimental phenomena were observed by visualization method and the reliable data were collected and analyzed. The results indicate that the entrainment rate will increase with the increase of gas flow rate under the same hg∗, and the entrainment rate will decrease significantly with the decrease of the mixed liquid level when the range of hg∗ is low. The results confirm that a large number of liquid droplets will be deposited on the surface of the reactor internals, which greatly reduces the entrainment rate. Under the same conditions, the entrainment rate with the reactor internals is about 10% of that without the reactor internals. There is a huge discrepancy between the existing pool entrainment rate models and the experimental data, with the maximum deviation of 200 times. Based on the experimental results, new upper plenum entrainment models for near surface region and high gas flux region of momentum controlled region are proposed. The error decreases by orders of magnitude compared to existing models, which suggested that the new model can accurately predict upper plenum entrainment phenomenon in the pressure vessel.

Development of protective egg yolk immunoglobulins (IgY) targeting CfaB, LTB, and EtpA recombinant proteins of Enterotoxigenic Escherichia coli (ETEC) for inhibiting toxin activity and bacterial adherence.

Enterotoxigenic Escherichia coli (ETEC) stands as a prevalent bacterial cause of global diarrheal incidents. ETEC's primary virulence factors encompass the B subunit of the Heat Labile Enterotoxin, along with the adhesion factors CfaB and EtpA. In this study, we isolated IgY antibodies against the three virulence factors individually, in pairs, and as triple cocktails. The in vitro efficacy of these IgY antibodies was examined, focusing on inhibiting heat-labile enterotoxin (LT) toxin cytotoxicity and impeding ETEC adherence to HT29 cells. Assessing the impact of IgY-treated bacteria on intestinal epithelial cells utilized the standard ileal loop method. Results demonstrated that the anti-LTB IgY antibody at 125µg/ml and IgY antibodies from double and tertiary cocktails at 200µg/ml effectively inhibited LT toxin attachment to the Y1 cell line. Pre-incubation of HT29 intestinal cells with specific IgYs reduced bacterial attachment by 59.7%. In the ileal loop test, toxin neutralization with specific IgYs curtailed the toxin's function in the intestine, leading to a 74.8% reduction in fluid accumulation compared to control loops. These findings suggest that egg yolk immunoglobulins against recombinant proteins LTB, CfaB, and EtpA, either individually or in combination, hold promise as prophylactic antibodies to impede the functioning of ETEC bacteria.

Design and PIL Implementation of Fuzzy Logic-based MPPT Control for Symmetrical Multilevel Boost Converter

This paper aims to introduce a fuzzy logic adaptive MPPT controller to control a symmetrical multilevel converter in a standalone PV system. The system is evaluated under fixed and variable solar radiation with 15 V as the input voltage 60 V as the required output voltage and 50 kHz as the switching frequency. Results prove that by using the controller, the system successfully tracks the MPPT point for constant and variable radiation without oscillation around the maximum power point. In addition, the overshoot and time response is reduced while the voltage ripples are eliminated. The proposed controller is verified through practical implementation in Arduino mega board to test the accuracy of results. The practical finding via a processor in the loop test validates the simulation results.

Three-phase flow measurement by dual-energy gamma ray technique and static-equivalent multi-phase flow simulator

There is a strong desire to use three-phase flowmeters in upstream operations because of their small size, portability, and cost-effectiveness. Traditional three-phase flowmeterstypically employ two main strategies: fully separating the flow into liquid and gas streams and measuring them using common two- and single-phase meters, or simplifying the direct measurement requirements by homogenization.In order to achieve accurate measurements with these meters, it is necessary to first create a suitable simulator for generating various multiphase flow regimes with minimal systematic error. Developing such a simulator on a laboratory scale, rather than using expensive test loops is a crucial and practical option.In this research, SEMPF as a Static-Equivalent Multi-Phase Flow with flexibility in creating different multi-phase flow regimes is introduced. In the following, the mechanism of action is validated for both homogenous two- and three-phase mixtures by using dual-energy gamma ray attenuation technique in the Monte Carlo simulator environment. Finally, the three-phase component fraction measurement accuracy by dual-energy gamma meter in three different modes of gasoil-, water-, and air-continuous mixtures were investigated. The experimental results show the maximum accuracy of 2.03 %, 7.23 %, and 5.09 % for gasoil phase measurement in three different conditions that the carrier phase is air, gasoil and water respectively.

Sand Detection Using Acoustic Sand Monitors for Liquid-Dominated Multiphase Flow Production

Summary Solid particle erosion in the oil and natural gas industry can be damaging to pipe fittings and equipment, which can lead to maintenance or, in the worst case, a production shutdown. In both cases, this represents a huge economic loss for industry. Acoustic sand monitoring is one of the most widely used practices to provide an alarm and/or estimate the amount of sand entrained in the flow. In addition to being commercially available, they can be easily clamped to the outside of a pipe wall, measuring the acoustic energy generated by sand grain impacts on the inner side of a pipe wall. In this work, a broad range of multiphase operating conditions has been experimentally investigated with acoustic sand monitors in large-scale flow loop facilities to determine the effectiveness of sand monitoring in liquid-dominated multiphase flow. The main objective is to use acoustic sand monitors to determine the threshold sand rate (TSR). This is the minimum sand rate necessary to achieve monitor output higher than the background noise (BN) level. Acoustic monitors were placed upstream and downstream of standard (r/D = 1.5) elbows while varying superficial gas and liquid velocities, sand sizes (25 μm, 75 μm, 150 μm, 300 μm, and 600 μm), and pipe diameters (2 in. and 3 in.) in the vertical orientation. The experimental conditions were selected to cover slug-churn, dispersed-bubble flow, and liquid-sand flow conditions. These results are compared with the previously obtained test results on 50.8-mm (2-in.) internal diameter (ID) test loops. In the 50.8-mm (2-in.) loop, threshold limits were observed for dispersed-bubble flow regimes and liquid-sand as compared with gas-dominated flow conditions. While TSR is the highest in dispersed-bubble flow regimes, the present data were compared with previous results obtained for annular, slug, and stratified flow patterns (FPs) in vertical flow. It was observed that the annular flow regime has the lowest TSR values, showing an increase in TSR when the liquid rate increased. The results from this work can help operators understand how acoustic monitors can detect and distinguish sand impact noise from the background flow noise in liquid-dominated multiphase flow in production facilities. In this way, greater assurance is provided to operators for optimizing oil and gas production rates, especially in wells that tend to produce solids.

Experimental investigation of flow boiling instability and associated pressure fluctuations in a mini-channel heat sink

Two-phase flow instability, inherently accompanied by hydraulic and thermal oscillations, is a complex phenomenon that must be overcome to design an efficient flow boiling heat transfer system. The potential factors influencing two-phase flow instability are so diverse and complex that many efforts have been devoted to identifying and classifying flow instabilities. Density wave oscillation and pressure drop oscillation in a single channel represent classical flow instabilities, and their mechanisms are relatively well established. However, parallel channel instability observed in multi-channel heat sinks is challenging to analyze due to flow interaction between neighboring channels through the inlet/outlet plenum. Even the number of channels, the size and shape of the plenum, and the inlet/outlet arrangement influence the fluid flow in multi-channel heat sinks, complicating the analysis of previous experimental data from the literature. Therefore, to address the complexity of multi-channel flow boiling and enhance the understanding of its behavior under specific conditions, additional experimental studies are essential. This study conducts flow boiling experiments using FC-72 with a mini-channel heat sink consisting of 22 parallel channels, each with dimensions of 1.6 mm in width and 4.8 mm in height, operating under two distinct pressure conditions. Flow instability occurring within the present channel flow boiling is investigated by visualizing the flow in the channel upstream and inlet plenum, as well as through spectral analysis of the pressure fluctuation. The fast Fourier transform was used to characterize the oscillation characteristics of transient pressure measured at various locations in the test loop. In addition, visualization data and fast Fourier transform results identified flow oscillation caused by vapor backflow in the channel. As a result, the present flow boiling data are classified as stable or unstable based on the frequency of pressure oscillation, and a new stability map for mini-channel flow boiling is proposed.

Synthesis and Performance Evaluation of Multialkylated Aromatic Amide Oligomeric Surfactants as Corrosion Inhibitor/Drag Reducing Agents for Natural Gas Pipeline.

Drag reducing agents (DRAs) including amphiphiles and polymers can enhance energy efficiency and transmission volume in natural gas pipelines. However, the correlation between DRA molecular structure and drag reduction efficiency remains unclear. In this paper, the multialkylated aromatic amides (MAA) oligomeric surfactants with different numbers of amide group/n-dodecane chain (from 1 to 3) were first synthesized and characterized. Then, the potential efficiency of MAA as the corrosion inhibitors (CIs)/DRAs for natural gas pipelines was investigated by interfacial activity analysis, film-forming property test, electrochemical polarization curve measurement, and in-door loop test. The results showed that the molecular structure is the key factor influencing the performance of MAA. By increasing the number of amide group/n-dodecane chains, the interfacial activity of MAA improves greatly, thus outstandingly affecting the film-forming property of the MAA on the carbon steel sheet. For MAA-1, the formed film is too thin to cover the surface roughness, and then the corrosion inhibiting (78.64%)/drag reducing (0-2%) rates are the lowest. For MAA-3, the formed film is the thickest and smooth, thus imparting the largest corrosion inhibiting (93.88%)/drag reducing (10-14%) rates to MAA-3. For MAA-2, the formed film is thicker but not smooth, and the corrosion inhibiting (89.88%)/drag reducing (4-6%) rates are intermediate. We speculate that the structure of the MAA greatly influences the adsorption and self-assembly of MAA on the inner pipe wall and then generates different performances. This work is helpful for guiding the development of natural gas DRAs with high efficiency.

Design and optimization of the components of a molten salt, thorium-fueled accelerator driven system

Molten Salt Accelerator-Driven Systems (MoSTADS) have been attracting a lot of research interest lately due to their unique characteristics and advantages, including reduced radiation damage of the fuel, and stable operation achieved through online fuel feeding process. Simulations of an experimental molten salt test facility being developed in the Thermal Hydraulic Research Laboratory (THRL) at Texas A&M University, were conducted using Monte Carlo radiation transport methods, to design and optimize selected components of the system. The system consists of a proton beam generated by an accelerator, impinging on a target to generate neutrons, which can be used induce fission reactions within a thorium fueled, high-temperature molten salt forced convection test loop. Parametric studies were performed to optimize several key components of the system including target material, proton beam energy, target thickness and location, and reflector thickness. Furthermore, in order to ensure the safe operation of the facility, parametric studies were also performed to identify the composition and thickness of the system shielding that would be needed to satisfy acceptable exposure limits.

Vehicle posture wheelbase preview control of in-wheel motors drive intelligent vehicle on potholed road

The in-wheel motors drive intelligent vehicle (IMDIV) has a strong ability of dynamic control, which makes it be a major development path of intelligent vehicles in the future. However, its stability is easily deteriorated by the impact of the road when driving on potholed road. To tackle this issue, a vehicle posture control method based on road feedback and elevation recognition is proposed. Firstly, an elevation recognition algorithm of adaptive Kalman filter (AKF) based on vehicle dynamic response is proposed after considering the flooded road and the system noise uncertainty. Secondly, a vehicle posture controller of fuzzy active disturbance rejection control (FADRC) is designed, with the function of dynamically adjusting the active disturbance rejection control (ADRC) parameters. It is designed to implement front suspension feedback control and rear suspension wheelbase preview control. At last, the road elevation recognition algorithm and vehicle posture control method are proved by Simulink simulation and off-line hardware in the loop test. The results revealed that the AKF can effectively recognize both white noise pavement and potholed road, and the recognition accuracy is greater than 90%. The FADRC controller realizes accurate front suspension feedback control and rear suspension wheelbase preview control by adjusting the real-time online parameters of ADRC. The proposed vehicle posture control method can effectively control the pitch and roll motion, which significantly improves the stability of IMDIV on potholed road. This study can serve as a reference for the posture stability control of IMDIV on potholed road.

Design of experimental facility for helium gas component testing

The current state-of-the-art helium gas test loops for component testing are constrained by the maximum operating temperatures, pressures, and flow rates of such facilities. Idaho National Laboratory is designing a new experimental facility known as HECTOR (HElium Component Testing Out-of-pile Research), which is a helium gas test loop for evaluating the performance of components to helium gas pressures, temperatures, and flow rates up to 8 MPa, 800 °C, and 0.15 kg/s, respectively. The construction of this facility will enable researchers to perform experiments across a wide range of Reynolds and Nusselt numbers, which could result in the maturation of technology for high-temperature gas-cooled reactor (HTGR) components.

Preparation and characterization of nano silver antibacterial gel for gynecolog

In this experiment, nano silver was prepared by photo reduction method, the trisodium citrate, polyvinylpyrrolidone-K30 and silver nitrate were added under the condition of water as solvent. Polyvinylpyrrolidone-K30 was used as dispersant, silver nitrate as precursors, and sodium citrate as reducing agent. (UV-vis) and scanning electron microscopy (SEM) showed that the diameter of prepared nano silver were between 50 nm and 80 nm, and the results showed that the shape of the nanosized silver nanoparticles were spherical and irregular. Carbomer940 was selected as the gel matrix which is stable and no stimulation, and the viscosity changes with the PH changes. The nanometer silver gels were prepared by mixing nano silver and carbomer940. The antibacterial loop test was carried out with Escherichia coli and Staphylococcus aureus. The antibacterial test showed that the prepared silver nanoparticles had antibacterial effect, and the antibacterial effect was tested by several kinds of nano-silver gels with different concentrations of 0 μg/ml, 4 μg/ml, 8 μg/ml, 12 μg/ml, 16 μg/ml, 20 μg/ml and 24 μg/ml. The results of bacteriostatic circle test showed that the gel had significant bacteriostatic effect on E. coli and S. aureus, which could cause gynecological inflammation. The optimal bacteriostatic concentration was between 12 microns/ml and 24 microns/ml.

Study on the Shear Degradation Law of Polymer Drag Reducing Agents

Abstract The use of drag reducing agents in oil pipeline transportation can reduce driving energy consumption and has certain energy-saving benefits. However, irreversible degradation occurs when polymer drag reducing agents are sheared through pumping. In order to study the viscosity loss of polymer drag reducing agents caused by mechanical shear during the pumping process, the combination of methods such as a rotational rheometer and an indoor drag reducing loop testing system was used to test and analyze the rheological and drag reducing properties of the drag reducing agent solution, and to study the shear degradation law of polymer drag reducing agent solution under different conditions. The results showed that the shear stress of the polymer drag reducing agent solution increased with the increase in shear rate, and the viscosity increased with the increase of shear stress, showing shear thickening. When the polymer drag reducing agent solution is not sheared, the drag reduction rate increases and then decreases with the increase of concentration, and reaches the maximum value at 20 mg·L−1. However, after shear, the drag reduction performance decreases rapidly, but the high concentration still maintains a good drag reduction rate. The research results provide a theoretical basis for improving the performance of polymer drag reducing agents under different operating conditions and play a guiding role in further improving and perfecting the polymer drag reducing technology.

Efficient Integration of PV Panels and Electrolysis through a High-Performance Converter for Clean Hydrogen Generation

Green power generation revolves around producing clean hydrogen. This is achieved through a process of generating hydrogen by electrolysis, which draws power from renewable energy sources. In this manuscript, a high performance step-down isolated dc-dc converter is proposed to interface the Photovoltaic (PV) panels and the electrolysis. This converter is highly efficient and capable of toggling on and off with minimal power consumption. The primary function of the electrolyser is to generate hydrogen, and the quantity of hydrogen produced correlates with the amount of electricity (current) it receives. To ensure seamless operation, a control system is employed. This system monitors the current and voltage of the electrolyser, ensuring it remains within optimal levels. To assess the efficacy of the proposed configuration, the system is simulated in MATLAB platform and a complete hardware in the loop test is performed using OPAL-RT OP4510.

Optimization design of unmanned mining truck path tracking controller based on road adhesion coefficient estimation

Abstract In response to the issues of inaccurate tracking precision caused by continuous turning and variable road adhesion coefficients on complex roads in mining areas for unmanned mining trucks, this paper adopts unscented Kalman filter (UKF) to estimate the road adhesion coefficient. Based on this, an adaptive preview feedforward linear quadratic regulator (LQR) control algorithm is designed using genetic algorithm, feedforward control, and linear quadratic optimal path tracking control methods. Firstly, a nine degree of freedom vehicle dynamics model and a two degree of freedom vehicle lateral dynamics model are established, and the Dugoff model to calculate tire forces is introduced; secondly, utilizing UKF to estimate the road adhesion coefficient, and leveraging active disturbance rejection control for rapid tracking of road curvature, an optimized design of the LQR controller is carried out. Then, the effectiveness of the designed controller was verified through Trucksim/Simulink joint simulation testing. Finally, the hardware in the loop test results showed that the designed controller had good tracking accuracy and strong adaptability in complex road and special working conditions in mining areas.

Implantable continuous-flow total artificial heart for newborns and small pediatric patients: First report of working model

ObjectiveThe need for safe and reliable mechanical circulatory support (MCS) for smaller children with severe heart failure (HF) is well defined. More specifically, in pediatric patients with advanced congenital HF, there is no implantable total artificial heart (TAH) device available for small patients. Herein, we report the development of the infant continuous-flow total artificial heart (I-CFTAH), a fully implantable in infants and newborns. MethodsAfter extensive engineering analysis, we performed an unprecedented effort: reducing the I-CFTAH's displacement volume to be 14% of the adult CFTAH pump while simultaneously decreasing pump diameter (6.2 cm to 2.6 cm) and axial length (9.8 cm to 4.8 cm). Facilitated by these proportional reductions, for the first time, a durable total artificial heart device was successfully fit in the chest of infants and newborns (height of ≥50 cm). ResultsThe functional I-CFTAH prototype demonstrated capability to support stable hemodynamics and desired device performance. The pump flow range (0.5-1.5 L/min) was confirmed in a mock circulatory testing loop. Within the tested flow range, the I-CFTAH can support small patients that could benefit from the intended cardiac output. ConclusionsThis successful effort demonstrated the feasibility of the miniature continuous-flow total artificial heart, intended for very small patient populations. I-CFTAH showed stable hemodynamics and could, therefore, become one of the few therapeutic options as a bridge to transplantation, aiming to enhance both the quality and duration of life for pediatric patients with advanced HF.