Efficiency of collective myosin Ⅱ motors studied with an elastic coupling power-stroke ratchet model

We proposed a modified ratchet model including power-stroke and elastic coupling to study the efficiency of collective non-processive motors such as myosin Ⅱ in muscle. Our theoretical results are in good agreement with the experimental data. Our study not only reveals that the maximum efficiency depends on elasticity and is independent of transition rates but also indicates that the parameters fitted to fast muscle are different from those fitted to a slow one. The latter may imply that the structure of the fast muscle is different from that of the slow one. The main reason that our model succeeds is that velocity in this model is an independent variable.

Efficiency of Model Induction Motor Using Various Non-Oriented Electrical Steels

The performance of a 3-phase 6-pole 400 W inverter-drive induction motor was investigated using a variety of non-oriented electrical steels for stator core at PWM inverter fundamental wave frequencies of 30 to 300 Hz. There existed an optimum Si content of the material depending on the tooth flux density. Both reduction of material thickness and stress-relief annealing of the stator core improved the motor efficiency. The influence of Si content on the efficiency was small at lower PWM frequencies, while at higher frequencies the motor efficiency increased with increasing Si content. The Cu loss WC increased and the Fe loss Wi counteractiveiy decreasedwith increasing Si content at lower frequencies; while at higher frequencies Wi had dominant effect on the efficiency. Newly developed materials RMA, having lower Fe losses after stress-relief annealing and higher flux densities with lower Si contents, showed motor efficiencies superior to conventional J1S grade materials with comparable Fe losses.

Improved Efficiency Test Method for the Motor Controller with SiC MOSFETs

The traditional measurement method was inaccurate to evaluate the motor controller efficiency,which the measurement efficiency value could be more than 100%in practical testing experiments.To deal with this issue,an improved electrical measurement method for the motor controller efficiency is proposed in this paper,which is established by analyzing the power loss distribution and phase currents of the motor controller.It is demonstrated that the SiC MOSFET chips are the main power loss devices in the motor controller,accounting for more than 93.1%of the total power loss.The accuracy of the proposed method is compared with the traditional method in simulation.It shows that the test error of the efficiency obtained by the traditional method fluctuates on a large scale,which varied from 0.094%to 1.911%.Compared with the traditional method,the test error of the proposed method appears to be less than 0.083%,which provides significant guidance for the motor controller efficiency test and design.

Motor Efficiency and Comparison of Children in Early Childhood from Greece Albania and Sweden

The purpose of this study was to observe record and compare the children＇s of early childhood performance of motor skills of different nationalities from Greece, Albania and Sweden. Additionally to investigate differences in motor performance between boys and girls and between age groups. The survey was conducted in the school years 2013-2014 and 2014-2015, and took place in the flame of the student exchange program ERASMUS internships of Preschool Education, University of loannina. The sample consisted of 369 infants （187 boys, 182 girls） aged 66 ± 7 months. The sample was selected according to the access that the team had in nursery schools of Ioannina （N1 = 133）, in Dervitsani （N2 = 131） Albania and Gothenburg （N2 = 105） of Sweden. The array of 18 different motor activities for children aged 4-6 years old was used to investigate the toddlers＇ degree of movement performance. They were used the manufacturer＇s instructions for the degree of movement performance and classification of the sample in different categories, while a descriptive statistics and analysis of variance （Three Way ANOVA） took place for sex factors, age and region of origin. The results showed that although there were differences in rates distributions and averages, there were no significant differences either between children from the three countries or between boys and girls, however, there were in the age groups with older children who achieved better rates.

Industrial Vision of High Efficiency Motors

This paper discusses the prospect of high efficiency motors based on usage in industrial sectors. In fact, energy consumption is globally classified into the industrial sector, transport system, residential and commercial building, agriculture and others sectors. In all the sectors, energy is eventually consumed by electrical appliances and equipments and the industrial sector accounts for the largest share of the overall energy consumption. The study concerns to identify the energy consumption using qualitative method. The main emphasis was given to comparison of the motor with high efficiency motors （HEMs） and traditional standard motors to investigate energy savings. According to the study, industrial sector has up to 25% of electrical energy conservation potential. Almost 70%-75% of the electrical energy consumption in industry is on account of use of electrical motors being used by pumps, fans, compressors and other motor driven system. Therefore, the potential for energy conservation through electric motors is quite high. Using high efficiency motors （HEMs） can thus reduce the losses and hence save vital energy costs. This paper will provide a contribution to electrical motors arena and will be a systematic knowledge base for researchers in this field.

Improving the Energy Efficiency of Cyclone Dust Collectors for Wood Product Factories

Dust collection systems represent a significant portion of a wood product manufacturer’s total electricity use. The system fan works against the static pressure of the entire system—the blast gates, the ductwork, and the upstream or downstream cyclone and/or baghouse. A poor system design (e.g., sharp elbows or undersized ductwork) increases the total amount of static pressure in the system, the fan’s performance curve shifts, increasing the total brake horsepower required by the fan (up to the maximum point on the curve). Additionally, system designers may oversize a dust collection system to ensure adequate dust capture and transport, either to accommodate system expansion or simply to be conservative. Since theoretical fan energy use increases with its velocity cubed, this can be an expensive safety net. This paper presents a comprehensive literature review about industrial cyclone dust collectors energy saving in relation to management, technologies, and policies. Energy-saving technologies like high-efficiency motors (HEMs), variable-speed drives (VSDs), leak detection, and pressure drop reduction have all been examined. Based on energy saving technologies results, it has been found that in the industrial sectors, a sizeable amount of electric energy, and utility bill can be saved using these technologies. Finally, various energy-saving policies were reviewed.

Current and efficiency of Brownian particles under oscillating forces in entropic barriers

In this study, considering the temporarily unbiased force and different forms of oscillating forces, we investigate the current and efficiency of Brownian particles in an entropic tube structure and present the numerically obtained results. We show that different force forms give rise to different current and efficiency profiles in different optimized parameter intervals. We find that an unbiased oscillating force and an unbiased temporal force lead to the current and efficiency, which are dependent on these parameters. We also observe that the current and efficiency caused by temporal and different oscillating forces have maximum and minimum values in different parameter intervals. We conclude that the current or efficiency can be controlled dynamically by adjusting the parameters of entropic barriers and applied force.

Current and efficiency optimization under oscillating forces in entropic barriers

The transport of externally overdriven particles confined in entropic barriers is investigated under various types of oscillating and temporal forces.Temperature,load,and amplitude dependence of the particle current and energy conversion efficiency are investigated in three dimensions.For oscillating forces,the optimized temperature–load,amplitude–temperature,and amplitude–load intervals are determined when fixing the amplitude,load,and temperature,respectively.By using three-dimensional plots rather than two-dimensional ones,it is clearly shown that oscillating forces provide more efficiency compared with a temporal one in specified optimized parameter regions.Furthermore,the dependency of efficiency to the angle between the unbiased driving force and a constant force is investigated and an asymmetric angular dependence is found for all types of forces.Finally,it is shown that oscillating forces with a high amplitude and under a moderate load lead to higher efficiencies than a temporal force at both low and high temperatures for the entire range of contact angle.

Dynamic neighborhood genetic learning particle swarm optimization for high-power-density electric propulsion motor

To maximize the power density of the electric propulsion motor in aerospace application,this paper proposes a novel Dynamic Neighborhood Genetic Learning Particle Swarm Optimization(DNGL-PSO)for the motor design,which can deal with the insufficient population diversity and non-global optimal solution issues.The DNGL-PSO framework is composed of the dynamic neighborhood module and the particle update module.To improve the population diversity,the dynamic neighborhood strategy is first proposed,which combines the local neighborhood exemplar generation mechanism and the shuffling mechanism.The local neighborhood exemplar generation mechanism enlarges the search range of the algorithm in the solution space,thus obtaining highquality exemplars.Meanwhile,when the global optimal solution cannot update its fitness value,the shuffling mechanism module is triggered to dynamically change the local neighborhood members.The roulette wheel selection operator is introduced into the shuffling mechanism to ensure that particles with larger fitness value are selected with a higher probability and remain in the local neighborhood.Then,the global learning based particle update approach is proposed,which can achieve a good balance between the expansion of the search range in the early stage and the acceleration of local convergence in the later stage.Finally,the optimization design of the electric propulsion motor is conducted to verify the effectiveness of the proposed DNGL-PSO.The simulation results show that the proposed DNGL-PSO has excellent adaptability,optimization efficiency and global optimization capability,while the optimized electric propulsion motor has a high power density of 5.207 kW/kg with the efficiency of 96.12%.