Number Of Poles Research Articles

Changes in the provision of ecosystem services based on sidewalk tree-composition scenarios

Cities have been experiencing environmental and social issues due to urban expansion processes, be them planned or not. However, several environmental solutions have been proposed and sidewalk tree planting stands out among them. The aim of the current research is to assess the process to estimate ecosystem services under different sidewalk tree composition scenarios in Irati and Curitiba cities, Paraná State. In order to do so, 10 street segments from neighborhoods sampled in city-wide inventories were selected. Information about sidewalk length, curb ramps’ width, and number of utility poles was collected for each street segment. The number of trees to be fit in each segment and sampled neighborhood was determined based on safety recommendations for these urban structures. Tree dimensions (Diameter at Breast Height - DBH, total height and crown diameter) were projected for the 55th year post-planting, based on using minimum dimensions of seedlings from small, medium and large-sized species. It was done to estimate ecosystem services in i-Tree Eco software. Significant differences among floristic composition scenarios (p<0.05) were observed for all ecosystem services in both cities. Compositions featuring large-sized species have show higher ability to provide ecosystem services, as well as higher monetary valuation, despite fitting a smaller number of trees in the assessed street segments. The herein formulated scenarios have shown the potential to increase the number of planted trees and to select compositions capable of maximizing ecosystem services’ provision and trees’ monetary value.

Design and Comparative Analysis of Axial Flux Permanent Magnet Vernier Motors

This paper analytically investigates both the air gap flux density and the generated power of an Axial Flux Permanent Magnet Vernier Motor (AFPMVM). The AFPMVM has the same operational principle as a magnetic gear. It operates using space harmonics of the air gap flux density due to the magneto-motive force (MMF) and air gap permeance. This paper also examines the effect of various combinations of the rotor magnet pole pairs, stator slots, and winding pole numbers on the power factor and power density using the 3-D finite element method (3D-FEM). It is observed that, although having a higher pole ratio results in low cogging torque and high power density, it makes the machine length longer and has a lower power factor. Therefore, by employing the high pole ratios, the main advantage of the axial flux machines, i.e. having a shorter length, is sacrificed.

Modular differential equations with movable poles and admissible RCFT characters

Studies of modular linear differential equations (MLDE) for the classification of rational CFT characters have been limited to the case where the coefficient functions (in monic form) have no poles, or poles at special points of moduli space. Here we initiate an exploration of the vast territory of MLDEs with two characters and any number of poles at arbitrary points of moduli space. We show how to parametrise the most general equation precisely and count its parameters. Eliminating logarithmic singularities at all the poles provides constraint equations for the accessory parameters. By taking suitable limits, we find recursion relations between solutions for different numbers of poles. The cases of one and two movable poles are examined in detail and compared with predictions based on quasi-characters to find complete agreement. We also comment on the limit of coincident poles. Finally we show that there exist genuine CFT corresponding to many of the newly-studied cases. We emphasise that the modular data is an output, rather than an input, of our approach.

ТРУДОВА ПОЛІТИКА НАЦИСТСЬКОЇ АДМІНІСТРАЦІЇ “ДИСТРИКТУ ГАЛИЧИНА”

The article examines the process of creating the occupying administration on the territory of “District Galicia”, and the structure, powers, and main directions of activity of departments dealing with the issues of mobilization and labor use of local labor resources are highlighted. The role of Nazi officials in campaigns to recruit and transport people to forced labor in the Reich was clarified. The position of the local Nazi leadership periodically did not follow the general political course in the occupied territories due to the career aspirations of certain government officials. It is important to assess the peculiarities of the formation and implementation of personnel policy in the occupation authorities, as the success of the implementation of state policy as a whole depends on human resources. Due to the insufficient number of German employees, the rate of recruitment was low. This led to the need to involve the local population in administrative work, which should have solved the problem according to the Nazi authorities. However, the increase in the number of Ukrainians and Poles in labor departments has exacerbated interethnic conflicts, which directly affected the effectiveness of these authorities, the main criteria of which were indicators of implementation of recruitment and mobilization plans. In addition, the attitude of the local population towards the activities of the occupying authorities has deteriorated due to their repressive and punitive policies. A few months after the establishment of the civil administration, the rate of registration of the working population of the District in workbenches has decreased significantly. These and other factors influenced the spread of protest tendencies among Galician Ukrainians regarding the refusal to go to work in Germany. Particular attention is paid to the assessment of the activities of Fritz Saukel's office and the measures taken by him to accelerate the recruitment of local people with a view to their further deportation to Germany. To improve interdepartmental coordination, a special unit was set up within the Reich Ministry of Labor, the European Employment Service (Europaamt für den Arbeitseinsatz). Structurally, it was divided into five departments, which aimed to help improve the regulation of labor used in all occupied areas of Europe and engaged in management training.

Influence of Rotor Pole Number on the Output of Double Stator Flux-Switching Machine

Influence of rotor pole numbers on the output performance of a double stator flux-switching permanent magnet machine is investigated and compared in this study. A description of the analyzed machine is first given. Maxwell-2D time-stepping finite element analysis is adopted in estimating the results. The no-load and load characteristics of the investigated machine is considered and quantitatively compared amongst four different rotor pole configurations. The compared machine categories are designated as: 6S/10P, 6S/11P, 6S/13P and 6S/14P, where P stands for rotor pole and S stands for stator slot. It is revealed that the compared 6S/11P machine topology has a lot of good qualities amongst all the compared machine types, since it exhibits the largest electromotive force (EMF), power, torque and greatest overload sustainability feature, etc. Though, the 6S/14P has excellent flux-weakening capability. Moreover, the 6S/13P machine configuration would produce the largest torque if all the compared machines are equipped with same amount of permanent magnet volume/material. The compared machine topologies have reasonably good anti-demagnetization potentials; particularly, the 6S/13P topology.

#188 : Platelet-Rich Plasma in Patients with In-Vitro Fertilization

Background and Aims: Successful embryo implantation requires the presence of a receptive endometrium, and unsuccessful implantation frequently results from a thin endometrial wall. A new approach of treating thin endometrium, platelet-rich plasma (PRP), has been shown to increase endometrial thickness, vascularity, and implantation rate. The aim of this study is to assess PRP’s efficacy as a treatment for infertile women undergoing in vitro fertilization and its benefit for ART. Method: This retrospective study data was implemented by collecting 26 infertile women who were sent to the Yasmin IVF Center at the Dr. Cipto Mangunkusumo General Hospital in Jakarta and had a history of unsuccessful implantation. Results: There were 26 patients who underwent IVF and received PRP infusion prior to FET. The clinical pregnancy rate in this study was 87,5% for women <35 years old and 47% for women >35 years old. The clinical pregnancy rate was determined by dividing the number of fetal poles with a heartbeat seen on the 6-week-old ultrasound by the overall number of transplanted embryos. Conclusions: Autologous PRP injections have shown a highly effective treatment for RIF and refractory thin endometrium.

Hybrid-Excited Variable Reluctance Resolver With Wide Speed Range

The accuracy of the variable reluctance resolver (VR-Resolver) highly depends on the rotational speed and its rotational speed range is limited by the frequency of the excitation signal. To eliminate the mentioned performance dependency, this paper proposes a hybrid-excited VR-Resolver (HVR-Resolver) with two separate sets of excitation windings: a toroidal excitation winding for the AC excitation supply and an on-tooth one for the DC excitation supply. Similar to the conventional method, the HVR-Resolver is working with AC excitation ON and DC excitation OFF at the low-speed range. For high-speed operation, the excitation switched from AC excitation to DC. By using this technique, the proposed HVR-Resolver is able to accurately estimate the position at a wide speed range. This feature makes the HVR-Resolver an outstanding candidate for EV applications. The proposed design is simulated using time-stepping finite element analysis (TSFEA) in order to study the performance at both low-speed and high-speed ranges with different rotor pole numbers. In addition, an optimization process is conducted to find the best rotor shape factors. The experimental test on the proposed HVR-Resolver indicates a close agreement between simulation and experimental results.

Arranging coil winding circuits of synchronous permanent-magnet machines on rotor

<span lang="EN-US">Methodology of constructing coil winding electrical circuits for salient-pole stator of electrical permanent-magnet machines on the rotor is proposed, which is based on the required number of pole pairs (synchronous speed) and the number of phases. The methodology algorithm is based on determining the value of the number of stator teeth as the closest to the number of rotor poles number value, multiple of phase number, which provides a sufficient level of pitch coefficient and winding coefficient. The algorithm was tested by several examples of constructing synchronous machines winding circuits, known from electrical engineering theory and practice, including mass-produced ones. In all the examples, if the proposed methodology guidelines were formally and strictly followed, the correct circuit designs came out as a result. For high power motor pilot design, one and the same machine design variants were compared, having thirty six slots on stator, three-phase and nine-phase windings, synthesized according to the proposed algorithm for thirty two-pole rotor. Engine torque calculation with both circuit options performed by finite elements method showed the nine-phase winding developed torque advantage by 20%, due to less discretion of MMF slot distribution.</span>

Online position error correction technique for sensorless control of multipole permanent magnet machines

In order to improve the reliability of electric machine drive systems, the position encoder is often replaced with an estimator, such as the extended Kalman filter. However, estimation errors can still occur, especially in machines with high pole number, commonly used in renewable energy systems. The high number of pole pairs amplifies the effect of estimation errors, leading to a substantial divergence between actual and controlled currents, potentially causing harm to the machine through the excessive heat generation or demagnetization of permanent magnets. To address this issue, an error compensation method has been proposed and tested in a control scheme for a tidal stream system based on a multipole dual-star permanent magnet synchronous generator. The method estimates the position error by determining the q-axis permanent magnet flux and correcting it through a PI regulator. Simulation results demonstrate the effectiveness of the proposed method, even with a non-null initial rotor position.

A Novel Dual Port Dual Rotor Wound Field Flux Switching Generator With Uniform and Non-Uniform Rotor Poles for Counter-Rotating Wind Power Generation

In this paper, a novel dual port counter rotating dual rotor wound field flux switching generator (DPCRDR-WFFSG) is proposed for direct drive counter rotating wind power generation. Mechanism of gearless and brushless counter rotating operation of DPCRDR-WFFSG is discussed and simplified formulation is opted for possible combination of the rotor poles number <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$(N_r)$</tex-math></inline-formula> . In proposed DPCRDR-WFFSG, dual electrical ports are formed of non-overlapped armature winding having shared toroidal field excitation winding whereas inner and outer rotors act as inner and outer port. These inner and outer port are thoroughly investigated for electromagnetic performance to search out optimum rotor poles combination. The rotor poles combinations are examined under uniform and non-uniform poles and comparatively studied. Based on simplified formulation, various combinations of the rotor pole numbers are searched out and found that under uniform poles operation, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N_r= 10$</tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N_r = 14$</tex-math></inline-formula> offers comparatively better electromagnetic performance whereas in case of non-uniform rotor poles <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N_r = 10/14$</tex-math></inline-formula> further improves electromagnetic performance. Furthermore, analysis evident that in comparison with the inner port, outer port shows dominant contribution in electromagnetic performance whereas, in comparison with uniform rotor poles, the new approach of adopting non-uniform rotor poles improve electromagnetic performance. It is worth noting that non-uniform rotor poles in inner ports improves efficiency and power factor whereas in outer port, average torque and output power are enhanced. Finally, validity of uniform and non-uniform rotor poles design approach for DPCRDR-WFFSG is verified with four prototype that validated finite element analysis.

Chronic administration of delta9-tetrahydrocannabinol protects hyperinsulinemic gastric tissue in rats.

Hyperinsulinemia (HI) can result from some reasons such as an increase in basal/fasting circulating insulin and/or potentiation of postprandial insulin production. Diabetes mellitus (DM) is indirectly related to HI since it both causes and results from insulin resistance. Understanding the causes of HI and treating this is crucial for preventing DM. Previous research has shown that delta9-tetrahydrocannabinol (THC) has medicinal benefits. In light of this, the relationship between THC and oxidative stress, DNA repair mechanism, apoptosis, and its regulatory impact on appetite hormones in the gastric tissue of hyperinsulinemic rats has been investigated for the first time. Male rats (Spraque-Dawley, total = 32) were used, and they were randomly divided into the following groups (n = 8 in each group): control (CTRL), HI, THC administered control (THC, 1.5 mg/kg/day, during 4 weeks), and THC administered HI (HI + THC) groups. The number of poly (ADP-ribose) polymerase-1 and proliferating cell nuclear antigen (PCNA) and caspase-3 immunopositive cells in the HI group was significantly reduced compared to the CTRL group. The number of PCNA and caspase-9 immunopositive cells was significantly increased in the HI + THC group compared to the HI group. Obestatin immunopositive cell numbers in the HI + THC group were higher than in the HI and CTRL groups. The results show that THC administration may affect the regulation of appetite hormones and regeneration in the fundus of rats with HI. Glutathione (GSH) levels were higher in the HI + THC group than in the HI group. Both immunohistochemical and biochemical analyses revealed that THC promotes regeneration and regulates appetite hormones in hyperinsulinemic gastric tissues.

Optimal gear ratio selection of linear primary permanent magnet vernier machines for wave energy applications

AbstractLinear permanent magnet vernier generators offer a high capability of force density, making them appealing configurations for wave energy harvesting systems. In absolute terms, the performance of these machines is significantly influenced by the selection of slot/pole combinations based on the magnetic gearing effect. For the first time, this paper aims to investigate the impact of different gear ratios on a wide array of linear primary permanent magnet vernier machines (LPPMVMs) with different slot/pole combinations based on fair criteria to offer a more comprehensive understanding of gear ratio selection. To find the optimal number of slots and poles, the response surface methodology is adopted to obtain a robust design and make a fair comparison among LPPMVMs with optimum design characteristics using a cost‐effective approach for the fast and reliable optimisation process. The higher gear ratios result in higher thrust force capability. This will help establishing a new route toward faster develpment of advanced LPPMVMs. The power loss models of LPPMVMs are studied to predict their steady‐state and transient thermal behaviours, verifying their stability and safety, while a simple external forced convection method can be utilised. To verify the model, finite element analysis is exploited to confirm the electromagnetic and thermal analysis results and provide a more exhaustive investigation.

Optimized design of permanent magnet for disk permanent magnet governor

To research the magnetic field and mechanical characteristics of the permanent magnet governor, the static magnetic field of the sector permanent magnet is analyzed by the molecular current method in the permanent magnet governor. The magnetic flux distribution is acquired at any spatial position. Comparing the analytical value with the simulation value, the results show that they are basically consistent. Based on the analytical formula, the influence of the radial position, radial length, thickness, and pole number on the magnetic induction intensity of the permanent magnet governor is studied. Thus, it provides the theoretical reference for the structural optimized design. At the same time, a test bench was set up to measure the magnetic induction intensity. The calculation and experimental results show that the magnetic induction strength of the permanent magnet is increased by 27.5%, the axial component of the air gap flux density is increased by 14.3%, and the permanent magnet material is reduced by 7.84%.

„Pamiętnik Harbiński” (1923-1924) – periodyk kolonii polskiej w Harbinie (Chiny)

The article is a presentation of the periodical “Pamiętnik Harbiński” [“The Harbin Diary”], which was published in the town of Harbin in China, in the years 1923–1924. There was quite a big Polish colony, connected with eastern Chinese railway built by Russia. Its administrative center was located in the place that soon developed into an economically thriving town called Harbin, established in 1898. Fair working conditions attracted many engineers, white collar and blue collar workers, including great numbers of Poles. Their growing educational and cultural needs brought fruit in the formation of Polish organizations and associations, as well as in the development of publishing market. One of the 25 identified Polish periodical titles that were published in Harbin from the beginnings of press publishing movement in 1917 to the eradication of Polish Diaspora in 1949 was “Pamiętnik Harbiński” which, due to its characteristic profile, deserves to be analyzed in a much greater detail.

On solutions to a novel non-evolutionary integrable 1 + 1 PDE

We investigate real solutions of a C-integrable non-evolutionary partial differential equation in the form of a scalar conservation law where the flux density depends both on the density and on its first derivatives with respect to the local variables. By performing a similarity reduction dictated by one of its local symmetry generators, a nonlinear ordinary differential equation arises that is connected to the Painlevé III equation. Exact solutions are secured and described provided a constraint holds among the coefficients of the original equation. In the most general case, we pinpoint the generation of additional singularities by numerical integration. Then, we discuss the evolution of given initial profiles. Finally, we mention aspects concerning rational solutions with a finite number of poles.

Developing an Intelligent Decision Support System for large-scale smart grid communication network planning

The placement of routers and gateways in wireless communication networks for Smart Grid Advanced Metering Infrastructure (AMI) is a complex problem often addressed in the literature through heuristics, clustering, or linear programming approaches. In large-scale scenarios, the complexity is directly related to the region’s number of smart meters and poles. The terrain profile can introduce signal quality degradation between a smart meter and the routers and gateways, further complicating the problem. This study presents the AIDA-ML method, representing a preliminary step toward developing an Intelligent Decision Support System (IDSS) for an effective positioning strategy. AIDA-ML incorporates a feature engineering-based strategy and utilizes machine learning algorithms to learn from the results computed by a heuristic method called AIDA. The heuristic approach is too time-consuming, relying on external resources like numerous terrain profile API calls and a deep understanding of wireless communication loss models. To implement a machine learning-based and more straightforward approach, a feature engineering process is employed to capture the operational characteristics and results of the analytical method while requiring less processing time. Through experiments conducted with real-world data from 26 cities in the state of Paraná, Brazil, comprising 466,237 smart meters and 352,867 poles, the results obtained using machine learning algorithms suggest that AIDA-ML can ensure the connection coverage of smart meters while meeting the same minimum requirements established for the analytical method. Moreover, AIDA-ML offers the advantage of reducing the processing time by 87.60% and by 96.86% the overall search space size compared to the heuristic approach.

Model based predictive control (MPC) with constraints applied to a multi-predictor scheme for linear delayed systems with an unstable pole

In the present work, a model based predictive control (MPC) strategy using a multi-predictor scheme for unstable high-order linear systems with delay is proposed. The stability analysis of this type of systems is difficult due to two main reasons, the appearance of an infinite number of poles when the feedback of the controller is considered and the second reason, is the delay size considered. In this work the use of a digital multi-predictor scheme is proposed, this device allows to estimate the internal variables of the process, which will be used for the design of the MPC to stabilize the plant. The present proposal considers an MPC with constraints in the control and output variables, which it is one of the most attractive features of this strategy. Numerical simulations are presented to illustrate how the efficiency of the system is increased due to the proposed control approach.

ANALYZING A THREE HUNDRED TEETH BI-PHASE HYBRID STEPPER MOTOR WITH DIFFERENT NUMBERS OF POLE PAIRS

The paper presents numerical models of a bi-phase, 0.3° full step hybrid stepper motor (HSM), with 16, 24, 32, 40, and, respectively, 48 poles in the stator. For the motor to move with a constant step angle, the stator and the rotor teeth must be shifted against each other with an angle of zero, 90, 180, and 270 electric degrees for each four consecutive stator poles. Due to this, bi-phase steppers with the number of poles in the stator different than eight are hardly seen. Therefore, to allow the construction of HSMs with different numbers of poles, some of the stator poles must be shifted from their symmetrical position. The five topologies' HSM detent and holding torque characteristics and their geometrical and constructive differences are presented. The Finite Element Method (FEM) based models are developed using the professional software COMSOL Multiphysics.

EXPONENTIAL ASYMPTOTICS USING NUMERICAL RATIONAL APPROXIMATION IN LINEAR DIFFERENTIAL EQUATIONS

AbstractSingularly perturbed ordinary differential equations often exhibit Stokes’ phenomenon, which describes the appearance and disappearance of oscillating exponentially small terms across curves in the complex plane known as Stokes lines. These curves originate at singular points in the leading-order solution to the differential equation. In many important problems, it is impossible to obtain a closed-form expression for these leading-order solutions, and it is therefore challenging to locate these singular points. We present evidence that the analytic leading-order solution of a linear differential equation can be replaced with a numerical rational approximation using the adaptive Antoulas–Anderson (AAA) method. Despite such an approximation having completely different singularity types and locations, we show that the subsequent exponential asymptotic analysis accurately predicts the exponentially small behaviour present in the solution. For sufficiently small values of the asymptotic parameter, this approach breaks down; however, the range of validity may be extended by increasing the number of poles in the rational approximation. We present a related nonlinear problem and discuss the challenges that arise due to nonlinear effects. Overall, our approach allows for the study of exponentially small asymptotic effects without requiring an exact analytic form for the leading-order solution; this permits exponential asymptotic methods to be used in a much wider range of applications.

RESEARCH THE EFFECT OF THE FRACTIONAL NUMBER SLOTS OF POLE ON WIND TURBINE GENERATION USING THE ENHANCED SPOTTED HYENA OPTIMIZATION ALGORITHM

The design of machines with permanent magnets is actively developing day by day and is often used in wind energy. The main advantages of such variable speed drives are high efficiency, high power density and torque density. When designing a wind generator with two rotors and permanent magnets, it is necessary to solve such a problem as the correct choice of the number of poles and slots to increase efficiency and minimize the cost of the machine. In this work, an improved spotted hyena optimization algorithm is used to obtain the optimal combination of slots and poles. This optimization algorithm makes it possible to obtain the number of fractional slots per pole and evaluate the operating efficiency of a wind generator with a double rotor and ferrite magnets. At the first stage of machine design, various combinations of slots are installed. Next, the optimal combination is selected from various slot-pole combinations, taking into account the Enhanced Spotted Hyena Optimization (ESHO) algorithm, in which a multi-objective function is configured. Accordingly, the multi-objectives are the integration of reverse electromotive force, output torque, gear torque, flux linkage, torque ripple along with losses. Analysis of the results obtained shows that the proposed algorithm for determining the optimal slot combination is more efficient than other slot combinations. It has also been found that the choice of slot and pole combination is critical to the efficient operation of permanent magnet machines.