Increase In Motor Speed Research Articles

Study on the influence of different factors on the performance of centrifugal supergravity oil-water separator

As the development of oil fields progresses, an increasing number of fields are entering high water-cut stages.Onsite oil-water separation and wastewater reinjection are crucial for reducing water treatment loads and energy consumption in crude oil transportation. Traditional oil-water separators suffer from issues such as large size and low separation efficiency. Therefore, this paper investigates a highly efficient centrifugal supergravity oil-water separator. Numerical simulations examined the impact of flow parameters, structural parameters, and physical properties on the separator’s flow field and performance. The research findings reveal that the oil-water separation efficiency decreases with an increase in water content. As the inlet flow increased, the oil content at the water outlet continuously rose. With an increase in motor speed, the separation efficiency initially increased and then stabilized. Within the simulated range, the number of blades was positively correlated with the separation effect, while the blade ripple radius, oil density, and viscosity were negatively correlated with the separator's effectiveness. An increase in orifice diameter caused fluctuations in the separation effect and the oil content at the water outlet.

Motor domain phosphorylation increases nucleotide exchange and turns MYO6 into a faster and stronger motor

Myosin motors perform many fundamental functions in eukaryotic cells by providing force generation, transport or tethering capacity. Motor activity control within the cell involves on/off switches, however, few examples are known of how myosins regulate speed or processivity and fine-tune their activity to a specific cellular task. Here, we describe a phosphorylation event for myosins of class VI (MYO6) in the motor domain, which accelerates its ATPase activity leading to a 4-fold increase in motor speed determined by actin-gliding assays, single molecule mechanics and stopped flow kinetics. We demonstrate that the serine/threonine kinase DYRK2 phosphorylates MYO6 at S267 in vitro. Single-molecule optical-tweezers studies at low load reveal that S267-phosphorylation results in faster nucleotide-exchange kinetics without change in the working stroke of the motor. The selective increase in stiffness of the acto-MYO6 complex when proceeding load-dependently into the nucleotide-free rigor state demonstrates that S267-phosphorylation turns MYO6 into a stronger motor. Finally, molecular dynamic simulations of the nucleotide-free motor reveal an alternative interaction network within insert-1 upon phosphorylation, suggesting a molecular mechanism, which regulates insert-1 positioning, turning the S267-phosphorylated MYO6 into a faster motor.

Study on the effect of cyclic catalytic pyrolysis on sludge pyrolysis products

Pyrolysis technology has become a hot issue in the industry of harmless treatment of sludge in recent years. The present ex-situ catalysis process suffers from the defects of unidirectional flow of pyrolysis steam, easy to form coke buildup on the catalyst surface, and poor heating value of the output heavy tar, which is difficult to be reutilized. This paper designed a cyclic catalytic cracking by pyrolytic steam process to optimize the above defects: under the optimal experimental conditions (pyrolysis starting temperature was 500 ℃, final temperature was 800 ℃, iron-based carbon catalyst dosage was 4 g, and motor speed was 1050 r/min), this process generated more pyrolysis gas and light tar. The increase in pyrolysis temperature had the most significant effect on pyrolysis gas yield, the dosage of iron-based carbon catalyst had the most significant effect on pyrolysis gas composition, and the increase in motor speed had the most significant effect on tar cracking. The cyclic catalytic cracking by the pyrolytic steam process can increase the residence time of pyrolysis steam in the reaction unit and promote the secondary cracking, catalytic, and reforming effects of tar.

Chronic supplementation of a multi-ingredient herbal supplement increases speed of cognitive task performance alongside changes in the urinary metabolism of dopamine and the gut microbiome in cognitively intact older adults experiencing subjective memory decline: a randomized, placebo controlled, parallel groups investigation.

The effects of herbs on brain function are often investigated in isolation, yet herbal preparations are often complex combinations of phytochemicals, designed to target widespread mechanisms. To assess the effects of chronic, 12 weeks, supplementation of a multi-ingredient herbal supplement (containing Bacopa monnieri, Gotu kola leaf, Turmeric whole powder, Reishi full spectrum, Rosemary, Cardamom, Holy Basil, Turmeric Wholistic™ extract, Green Tea & Seagreens) on cognitive function in older adults with subjective memory decline. Secondly, to investigate whether effects are underpinned by shifts in microbial composition and/or metabolism of the herbs. Male and female participants (N = 128) aged between 55-75 years completed lab-based cognitive assessments, and provided stool and urine samples, at baseline and then following 90 days of multi-ingredient herb, or placebo, supplementation. Deficits in memory were observed in response to 90 days of multi-ingredient herbal supplement supplementation but the positive effects were all focused on speed of cognitive task performance, with an additional improvement in the false alarm rate on the rapid visual information processing task. These improvements coincided with an increased presence of tyrosine in the urinary metabolome and this may implicate the role of dopamine in these processing and/or motor speed increases. Finally, multi-ingredient herbal supplementation significantly reduced levels of 3 bacterial species in the gut microbiome and one of these, Sutterella, coincides with lower levels of constipation reported in the multi-ingredient herbal supplement condition. A multi-ingredient herbal supplement increases speed of cognitive task performance and increased metabolism of tyrosine suggests that this is modulated by increased dopaminergic activity. Reduced levels of Sutterella in the gut is associated with improved bowel movements of participants. Interpretation of the negative effects on memory are, however, stymied by an unequal randomization of participants into treatment groups pre- and post-COVID 19.Clinical trial registration: identifier NCT05504668.

Investigation of the Effect of Different Engine Oils on the Amount of Cylinder Liner Wear

In internal combustion engines, cylinder liner wear is a significant factor that adversely affects engine performance. The rough surfaces and geometric changes resulting from wear impede gas flow, reduce compression, and decrease combustion efficiency. This leads to a decrease in engine power, an increase in fuel consumption, and a loss of performance. Therefore, the control of cylinder liner wear and the use of appropriate lubricating oils are of great importance in enhancing motor performance. This study experimentally investigates the effects of different lubricants on cylinder liner wear in the context of internal combustion engines. The study is conducted under various loads and speeds. The commonly used 5W30 and 10W40 lubricating oils are employed as lubricants. Based on the results of the wear tests, it is observed that as the applied load on the cylinder liner increases, the wear amount also increases. Additionally, motor speed is identified as another influential parameter on wear amount. As the motor speed increases or decreases, the wear amount decreases or increases, respectively. The study reveals that the minimum wear amount is obtained with the 10W40 lubricating oil. Furthermore, SEM images are examined to assess the resulting damages on the cylinder liners after the wear tests.

Research on Motor Rotor Loss of High-Speed Air Compressor in the Application of Hydrogen Fuel Cell Vehicle

As an important component of hydrogen fuel cell vehicles, the air compressor with an air foil bearing rotates at tens of thousands of revolutions per minute. The heat generation concentration problem caused by the high-speed motor loss seriously affects the safe and normal operation of the motor, so it is very important to clarify the loss distribution of the high-speed motor and adopt a targeted loss reduction design for air compressor heat dissipation. In this paper, for an air compressor with a foil bearing with a rated speed of 80,000 rpm, an empirical formula and a three-dimensional transient magnetic field finite element model are used to model and calculate the air friction loss, stator core loss, winding loss and permanent magnet eddy current loss. The accuracy of the analytical calculation method is verified by torque test experiments under different revolutions, and the average simulation accuracy can reach 91.1%. Then, the distribution of the air friction loss, stator core loss, winding loss and eddy current loss of the air compressor motor at different revolutions is obtained by using this method. The results show that the proposed method can effectively calculate the motor rotor loss of a high-speed air compressor with air foil bearing. Although the motor efficiency increases with the increase in motor speed, the absolute value of loss also increases with the increase in motor speed. Stator core loss and air friction loss are the main sources of loss, accounting for 55.64% and 29% of the total motor loss, respectively. The electromagnetic loss of winding, the eddy current and other alloys account for a relatively small proportion, which is 15% in total. The conclusions obtained in this paper can effectively guide calculations of motor loss the motor heat dissipation design of a high-speed air compressor with an air foil bearing.

Non-Faradaic Electrochemical Energy Transduction Using Catalytic Motors

Mechanical energy generated by self-powered catalytic motors encourages researchers to explore whether their dynamics can be harnessed in developing inexpensive and efficient energy transduction and storage platforms. Herein, we present a non-Faradaic electrochemical energy transduction strategy using buoyancy-driven self-propelled catalytic motors within an electrochemical setup containing a fluorinated tin oxide working electrode and a sustained salt gradient. During propulsion, the motors facilitated advective transfer of ions from the bottom of the fuel solution to the electrode and subsequent formation of an electric double layer capacitor (EDLC) over it. The magnitude of EDLC charging was estimated using open circuit potential (OCP) measurements, which was found to increase with the number of motors in solution. We also observed instantaneous potential spikes over the OCP signal profile, when a motor struck the electrode surface, the frequency of which gets enhanced with the increase in motor speed through the solution. We quantify the OCP generated as a function of number of motors and composition of the fuel solution and also offer an explanation of the energy transduction mechanism in the system. It is expected that catalytic motor-assisted non-Faradaic energy generation will establish itself as an important energy harvesting pathway and when miniaturized, will open up avenues for fabricating autonomous power sources for smart sensors and other devices.

"Prefrontal Cortex Neuromodulation Improves Motor-Cognitive Components in Latinx Hispanic People Living with HIV"

Background: HIV is an immunodeficiency virus that currently has no cure but is managed with antiretroviral medication (ART). ART has increased the life expectancy of those living with HIV. Evidence shows a correlation between the increase in life expectancy and increases in neurological motor-cognitive impairments, thus leading to a decline in functional mobility and overall quality of life. The current study aimed to address neurological motor cognitive impairments in Latinx HIV+ individuals using transcranial direct current stimulation (tDCS).Methods: Female and male participants, ages 18-65, with an HIV diagnosis by a medical doctor and a CD4 count of >300 were obtained from an HIV clinic in La Perla de Gran Precio in Puerto Rico. Spatiotemporal data were collected; each subject participated in a dual cognitive ambulation task and completed the HIV dementia scale.Results: Dual cognitive tasks were calculated for cadence, gait cycle, gait speed, single limb, double limb, stance, stride, swing, and sway were analyzed. After the application of tDCS, the only statistically significant difference found among the subjects was an improvement in gait speed (p≤.05). In addition, the cognitive component showed an improvement in the HIV dementia scale total (p≤.05), including an increase in motor speed and memory recall (p≤.05).Conclusion: tDCS may be a feasible and effective treatment option for this population to alleviate motor-cognitive alterations in those living with HIV. Future research should consider the benefits of tDCS combined with diverse training, such as gait or balance activities.

Advanced deep flux weakening operation control strategies for IPMSM

This paper proposes an advanced flux-weakening control method to enlarge the speed range of interior permanent magnet synchronous motor (IPMSM). In the deep flux weakening (FW) region, the flux linkage decreases as the motor speed increases, increasing instability. Classic control methods will be unstable when operating in this area when changing load torque or reference speed is required. The paper proposes a hybrid control method to eliminate instability caused by voltage limit violation and improve the reference velocity-tracking efficiency when combining two classic control methods. Besides, the effective zone of IPMSM in the FW is analyzed and applied to enhance stability and efficiency following reference velocity. Simulation results demonstrate the strength and effectiveness of the proposed method.

Laboratory stand with wireless interface for investigation of automatic control systems of dc electric drives

Purpose. Development of a laboratory stand with a wireless interface for the study and research of automatic control systems for DC electric drives.
 Methodology. Physical experiment on the developed laboratory bench, computer modelling, calculation and analytical methods.
 Findings. The study considered and analyzed the advantages and disadvantages of existing developments of laboratory stands with virtual and remote components, the possibility of organizing a wireless interface, taking into account cost-effectiveness, mobility, reliability and simplicity, as well as the possibility of using as a training stand. The connection of the stand by means of USB and Wi-Fi is developed. The STM32F103C8T6 microcontroller is used for the power switch and the automatic control system. The interface part consists of a NodeMCU board, a MicroSD card module, an interface control unit, a 16x2 LCD and an I2C converter. The UART-USB interface is used for information transfer and programming of the stand. The possibility of current remote transmission of information about the modes and parameters of the engine to a computer with a browser output by installing the Wi-Fi module ESP8266MOD. A closed system of automatic DC motor control with PID current regulators and EMF has been developed. Experiments were performed with a pulse and smooth increase in motor speed and variation of the components of the PID controllers using the control panel of the laboratory stand. All graphs of the results of the experiment were obtained on a web page with a fixed IP address in the browser via Wi-Fi.
 Originality. The structure of the remote monitoring and control system based on hardware and software combination of telecommunication and measuring systems is proposed and developed, which differs from the existing ones by the presence of current wireless transmission of information, which allows to remotely receive research data of automatic DC motor control systems.
 Practical value. The developed laboratory stand with the wireless interface allows to receive and store experimental data on parameters of the investigated engine in real time remotely.

DESIGN AND EXPERIMENTAL STUDY OF THE COMB-TYPE HARVESTING TEST BENCH FOR CERASUS HUMILIS

A comb-type harvesting test bench was designed to address low fruit collection rate and theoretical analysis and simulation analysis of the harvesting process were carried out in this work. Single factor simulation experiment and bench experiment were carried out, and fruit collection rate was used as the evaluation index. The motor speed, bending angle of comb teeth and radial diameter of comb teeth arrangement were selected as the experimental factors. Results showed that the collection rate decreased with the increase of motor speed; and increased with the increase of the bending angle of comb teeth or the radial diameter of comb teeth arrangement. The orthogonal experiment of three-factor and three-level quadratic rotation centre combination was performed. The results showed that motor speed had the largest effect on collection rate, followed by radial diameter of comb teeth arrangement and bending angle of comb teeth. The optimal parameter combination was predicted by the response surface model as follows: motor speed of 25 r/min, bending angle of comb teeth of 120°, radial diameter of comb teeth arrangement of 868.45 mm and correspondingly the collection rate reached 91.51%. Based on actual harvesting efficiency and the machining problems of the test bench, the bench experiment was performed with the motor speed of 25 r/min, the bending angle of comb teeth of 120°, the radial diameter of comb teeth arrangement of 900 mm, and the collection rate was 93.82%. The relative error with the predicted optimal result was 2.48%, achieving the purpose of improving the collection rate.

Design of High-Speed Permanent Magnet Motor Considering Rotor Radial Force and Motor Losses

Different from the design of conventional permanent magnet (PM) motors, high-speed motors are primarily limited by rotor unbalanced radial forces, rotor power losses, and rotor mechanical strength. This paper aimed to propose a suitable PM motor with consideration of these design issues. First, the rotor radial force is minimized based on the selection of stator tooth numbers and windings. By designing a stator with even slots, the rotor radial force can be canceled, leading to better rotor strength at high speed. Second, rotor power losses proportional to rotor frequency are increased as motor speed increases. A two-dimensional sensitivity analysis is used to improve these losses. In addition, the rotor sleeve loss can be minimized to less than 8.3% of the total losses using slotless windings. Third, the trapezoidal drive can cause more than a 33% magnet loss due to additional armature flux harmonics. This drive reflected loss is also mitigated with slotless windings. In this paper, six PM motors with different tooth numbers, stator cores, and winding layouts are compared. All the design methods are verified based on nonlinear finite element analysis (FEA).

Experimental investigation of two-phase flow and heat transfer performance in a cooling gallery under forced oscillation

Abstract The demand of increasing power density of the Internal Combustion Engine promotes the technology development using internal cooling gallery of the piston. The oil flow and heat transfer performance of the piston internal cooling gallery have great influence on the cooling performance, which affects the thermal conditions of the piston and of the entire engine. The experimental study using visualising method is therefore critical and important to observe the flow patterns inside the piston gallery. In this paper, we presented the visualised study of two-phase flow patterns within an open cooling gallery by using a high-speed camera at various crank angles. The effects of motor speed both on the flow patterns and temperature distribution were investigated and the heat transfer mechanisms in gas-liquid two-phase flow during reciprocating motion were explored. Based on the study, the period-doubling phenomenon, which represented the transition from laminar flow to turbulent flow, was observed when the speed was around 400–500 rpm. Results indicated the increase of motor speed can effectively improve the cooling performance. Results also showed when the speed was higher than 600 rpm, the reduction of temperatures was quite close, which proven the existence of optimal or minimum requirement of motor speed to achieve good quality cooling performance. The results obtained in this study could be used as a critical reference for numerical studies and important experimental reference to further investigate the design and optimisation of engine cooling gallery for vehicle application.

Design and development of injection moulding machine for manufacturing maboratory

This paper presented the design process and manufacturing of a benchtop and inexpensive injection moulding machine for use as learning and teaching equipment in a manufacturing laboratory. The design use a vertical plunger type of injection equipped with clamping system. The maximum volume of barrel is 290 cc combined with injection plunger 60 mm provides ideal capacity for lab. The design concept process and preliminary test result are discussed. The flow rate increases with increase of motor speed and the packing time decrease with increase of motor speed. At 2500rpm the flow rate is 0.42m/s and pack time is 15 second.

Multiwavelength Light-Responsive Au/B-TiO2 Janus Micromotors.

Conventional photocatalytic micromotors are limited to the use of specific wavelengths of light due to their narrow light absorption spectrum, which limits their effectiveness for applications in biomedicine and environmental remediation. We present a multiwavelength light-responsive Janus micromotor consisting of a black TiO2 microsphere asymmetrically coated with a thin Au layer. The black TiO2 microspheres exhibit absorption ranges between 300 and 800 nm. The Janus micromotors are propelled by light, both in H2O2 solutions and in pure H2O over a broad range of wavelengths including UV, blue, cyan, green, and red light. An analysis of the particles' motion shows that the motor speed decreases with increasing wavelength, which has not been previously realized. A significant increase in motor speed is observed when exploiting the entire visible light spectrum (>400 nm), suggesting a potential use of solar energy, which contains a great portion of visible light. Finally, stop-go motion is also demonstrated by controlling the visible light illumination, a necessary feature for the steerability of micro- and nanomachines.

Impact of age, sex, socioeconomic status, and physical activity on associated movements and motor speed in preschool children

ABSTRACTIntroduction: Young children generally show contralateral associated movements (CAMs) when they are making an effort to perform a unimanual task. CAM and motor speed are two relevant aspects of motor proficiency in young children. These CAMs decrease over age, while motor speed increases. As both CAM and motor speed are associated with age, we were interested in whether these two parameters are also linked with each other. Method: In this study, three manual dexterity tasks with the dominant and nondominant hands (pegboard, repetitive hand, and repetitive finger tasks) were used to investigate the effect of covariates (age, sex, socioeconomic status, total physical activity) on both motor speed and CAMs in preschool children. Results: There was a significant age effect for both motor speed and CAMs in all tasks when the dominant hand was used. When the nondominant hand was used, the decrease in the intensity of CAMs over age was not consistently significant. The influence of physical activity and socioeconomic status on motor proficiency was small. Furthermore, the correlation between motor speed and CAMs, although significant, was low. Conclusions: Motor speed improved with age over three fine motor tasks in preschool children. Decrease in CAMs was observed but it was not always significant when the nondominant hand was working. Motor speed and CAMs were only weakly associated. We conclude that the excitatory pathways responsible for motor speed and inhibitory pathways responsible for reducing CAMs occupy two different domains in the brain and therefore mostly behave independently of each other.

Active torque ripple reduction based on an analytical model of torque

The vibration caused by torque ripple may degrade the performance of drivetrain, thus the reduction of torque ripple are necessary for hybrid electrical vehicle/electrical vehicle application, while an analytical description of torque will be the basis. In this study, two-dimensional Fourier series supplemented by polynomial fitting is introduced to reconstruct the numerical solution of magnetic coenergy (MCE) from finite element analysis. An analytical torque model, which can describe torque ripple precisely at all working points, is derived from the reconstructed MCE. On the basis of the torque model, the expressions of harmonic currents used to reduce torque ripple are obtained. The proposed expression also satisfies the principle of maximum torque per ampere. Then, a feedforward torque controller based on the expression of harmonic currents is introduced. Meanwhile, a feedback torque controller based on a torque observer is developed as a comparison. The results of simulation and experiments show that both two controllers can reduce the torque ripple in steady state, but the feedforward torque controller has obviously better effects when motor speed increases. Furthermore, the feedforward torque controller is also beneficial to decline torque ripple during transient process of torque response.

Catalytic Locomotion of Core-Shell Nanowire Motors.

We report Au/Ru core-shell nanowire motors. These nanowires are fabricated using our previously developed electrodeposition-based technique, and their catalytic locomotion in the presence of H2O2 is investigated. Unlike conventional bimetallic nanowires that are self-electroosmotically propelled, our open-ended Au/Ru core-shell nanowires show both a noticeable decrease in rotational diffusivity and increase in motor speed with increasing nanowire length. Numerical modeling based on self-electroosmosis attributes decreases in rotational diffusivity to the formation of toroidal vortices at the nanowire tail, but fails to explain the speed increase with length. To reconcile this inconsistency, we propose a combined mechanism of self-diffusiophoresis and electroosmosis based on the oxygen gradient produced by catalytic shells. This mechanism successfully explains not only the speed increase of Au/Ru core-shell nanomotors with increasing length, but also the large variation in speed among Au/Ru, Au/Rh, and Rh/Au core-shell nanomotors. The possible contribution of diffusiophoresis to an otherwise well-established electroosmotic mechanism sheds light on future designs of nanomotors, at the same time highlighting the complex nature of nanoscale propulsion.

The Influence of the Magnetic Force Generated by the In-Wheel Motor on the Vertical and Lateral Coupling Dynamics of Electric Vehicles

For the in-wheel motor (IWM)-driven electric vehicle, the drive motor is directly integrated in the wheel. The magnet gap deformation of the motor can be generated due to road surface roughness (RSR) excitation, uneven load, and other reasons. The magnet gap deformation will lead to unbalanced magnetic force, which is a critical vibration source to the vehicle dynamics. Focusing on this problem, an IWM-driven electric vehicle without a speed reducer is considered as the research subject, and an 11-degree-of-freedom dynamics model is developed and verified to study the magnetic force influence on vehicle vertical and lateral coupling dynamics. The effect of magnetic force on the vehicle dynamics is analyzed under two operation conditions first. The results show that the magnetic force makes all dynamic response variables deteriorate in different degrees, regardless of the operation conditions, which indicates that the magnetic force has some negative influence on both the vertical and lateral vehicle dynamics. The results also show that even if the hub bearing stiffness is 5 MN/m, the maximum magnet gap deformation of the IWMs can still reach a big value. Therefore, the hub bearing stiffness should be designed to be stiff enough to conquer the magnet gap deformation under permitting conditions. In addition, extended study is performed with different motor speeds to further investigate the vehicle coupling dynamics. The results show that all the root-mean square (RMS) values of the evaluation indexes increase with the increase in motor speed. This result contributes to both RSR and magnetic force, since the motor speed is not only related to road excitation but also concerns magnetic force. For electric vehicles driven by IWMs, magnetic force must be considered as one of the important factors in the system design. This study can provide some theoretical basis for the design, optimization, and coordinated control of the IWM-driven electric vehicles.

Are Weight Status and Cognition Associated? An Examination of Cognitive Development in Children and Adolescents with Anorexia Nervosa 1 Year after First Hospitalisation.

ObjectiveThe aim of this study was to characterise the association between the cognitive profile and weight restoration in children and adolescents with anorexia nervosa.MethodsThe study was a longitudinal, matched case–control, multicentre study. An assessment of cognitive functions was conducted by using the Wechsler Intelligence Scale for Children–III/the Wechsler Adult Intelligence Scale–III, the Test of Memory and Learning–second edition, Trail Making Tests A and B, the Rey–Osterrieth Complex Figure Test and the Cambridge Neuropsychological Test Automated Battery.ResultsOne hundred twenty individuals, 60 patients with anorexia nervosa with mean age of 14.65 (SD 1.820) years and 60 healthy controls with mean age of 14.76 (SD 1.704) years, participated. No association was found between weight recovery and cognitive functions. However, a significant increase in motor speed was found in Trail Making Test A (p = 0.004), Reaction Time (RTI) five‐choice movement time (p = 0.002) and RTI simple movement time (p = 0.011), resulting in a normalisation corresponding to that found in healthy controls. Furthermore, a significantly lower score in the perceptual organization index (p = 0.029) was found at follow‐up.ConclusionsWeight recovery appears not to be associated with cognition. Copyright © 2016 The Authors European Eating Disorders Review published by Eating Disorders Association and John Wiley & Sons Ltd