Length Of Poly Research Articles

Calculation of Cogging Force in Permanent Magnet Linear Motor Using Analytical and Finite Element Methods

In a permanent magnet (PM) linear motor, there is a force ripple which is detrimental to positioning. This force ripple is mainly due to a cogging force and a mutual force ripple. These forces are affected by the geometric parameters of a brushless PM motor, such as the width of the magnet, the height of the magnet, the shifted length of the magnetic pole, the length and height of the armature and the slot width. The optimal design can be found by considering force ripple as a cost function and the geometric parameters as design variables. In this paper, we calculate the flux density distribution in the air gap using the analytic solution of Laplace and Possion equations in the function of geometric parameters. The cogging force is obtained by integrating the Maxwell stress tensor, which is described by the flux density distribution on the slot face and end face of the iron core of an armature. Finally, a finite element method is presented in order to compare with the previous method.

Pyeloureterostomy in the Management of the Lower Pole Pelvi-ureteric Junction Obstruction in Incomplete Duplicated Systems

To report our experience with the pyeloureterostomy (PU) for the treatment of the lower pole PUJO in incomplete duplex systems. The combination of the duplicated collecting system and pelviureteric junction obstruction (PUJO) is a rare association and infrequently reported. Surgical treatment can be challenging in such cases. We retrospectively reviewed the medical data of the patients who had surgery from 2001 to 2009, with a diagnosis of PUJO of the lower pole moiety in incomplete duplex system. Demographic, diagnostic, and procedural data were recorded. Seven patients were identified with the lower pole PUJO associated with incomplete duplex systems. Their median age was 49 months (range 2-108 months). Prenatal hydronephrosis was detected in 3 patients, and 4 had a febrile urinary tract infection. PU was performed in 6 patients because of short ureteral length between the ureteropelvic junction and junction of lower and upper pole ureters. One patient was treated with the dismembered pyeloplasty because of sufficient ureteral length of the lower pole. No complications were detected during 14 months of follow-up. The management of the lower pole PUJO in incomplete duplex systems should be individualized for every patient. PU is a good surgical option in the management of the lower pole PUJO associated with incomplete ureteral duplication.

Pole length affects cross-country skiers’ performance in an 80-m double poling trial performed on snow from standing start

We investigated the hypothesis that longer and shorter poles would be faster and slower, respectively, than poles of self-selected length in all-out double poling. Eight elite cross-country skiers performed 80 m all-out double poling on snow performed from a standing start. Three trials with each of the pole lengths: self-selected, 7.5 cm shorter, and 7.5 cm longer than self-selected were performed. Time was recorded every 20 m and skiers were filmed during the last 40 m for calculation of cycle rate and length. Times at 80 m were 0.9 ± 0.7% shorter with longer poles than with self-selected poles (p ≤ 0.05), while they were 1.2 ± 1.0% slower with shorter poles (p ≤ 0.05). Much of these differences were established within the first 20 m. Calculated lead at 80 m with longer poles was 0.88 ± 0.65 m over self-selected poles (p ≤ 0.05). Mean cycle rate and length ranged from 1.35 to 1.45 Hz and from 4.84 to 5.52 m, respectively, across pole lengths (p > 0.05).

Highly narrow rejection bandwidth finite impulse response notch filters for communication

Design of finite impulse response (FIR) notch filters (NFs) with highly narrow rejection bandwidth (RBW) is suggested. RBW is the distance between 3 dB points on the response. Reduction in the RBW is achieved progressively in three stages. In the first stage, an FIR NF is designed from a second order infinite impulse response (IIR) prototype filter. For a given length L of the NF, the authors choose maximum permissible value of ` r ' (the pole length of IIR prototype filter) to achieve very narrow RBW of the FIR filter. In the next stage, by using an amplitude change function (ACF): H ( z )(2 - H ( z )), the designed filter is sharpened. Consequently, the RBW of the resulting NF is reduced to almost half of the earlier value. This reduction of bandwidth makes the resulting NF of length 2 L . In the next stage, RBW can be further reduced by the repeated sharpening of the filter by the same ACF.

Relationships between body composition, body dimensions, and peak speed in cross-country sprint skiing

In modern sprint cross-country skiing, strength and maximal speed are major determinants of performance. The aims of this study were to ascertain the anthropometric characteristics of world-class sprint skiers and to evaluate whether a specific body composition and/or body dimension characterizes a successful sprint skier. Our hypothesis was that body height and lean body mass are related to peak speed in double poling and diagonal stride. Fourteen male national and international elite skiers performed two peak speed tests in double poling and diagonal stride roller skiing on a treadmill and were analysed using dual-energy X-ray absorptiometry to determine body composition and body dimensions. Relative pole length was positively correlated with both techniques (double poling: r = 0.77, P < 0.01; diagonal stride: r = 0.60, P < 0.05) and was the only variable that was part of the multiple regression model for both double poling and diagonal stride peak speed. Body height was not correlated with any technique, whereas lean trunk mass (r = 0.75, P < 0.01), body mass index (r = 0.66, P < 0.01), total lean mass (r = 0.69, P < 0.01), and body mass (r = 0.57, P < 0.05) were positively related to double poling peak speed. Total lean mass (absolute: r = 0.58, P < 0.05; relative: r = 0.76, P < 0.001) and relative lean mass of the trunk, arms (both r = 0.72, P < 0.01), and legs (r = 0.54, P < 0.05) were positively related to diagonal stride peak speed. In conclusion, skiers should aim to achieve a body composition with a high percentage of lean mass and low fat mass. A focus on trunk mass through increased muscle mass appears to be important, especially for double poling. The use of longer poles (percent body height) seems to be advantageous for both double poling and diagonal stride peak speed, whereas body dimensions do not appear to be a predictive factor.

Energy Expenditure and Comfort During Nordic Walking With Different Pole Lengths

Energy expenditure and comfort for Nordic walking with self-selected and 7.5-cm shorter poles and ordinary walking were measured during uphill (12 degrees ), downhill (12 degrees ), and horizontally. Twelve (11 women and 1 man) Nordic walking practitioners participated (mean +/- SEM: 171.5 +/- 1.5 cm, 67.0 +/- 2.7 kg, 50.6 +/- 2.4 years, and maximal oxygen uptake of 43.4 +/- 2.8 mL x kg(-1) x min(-1)). Energy expenditure was calculated from oxygen uptake and comfort was self-rated. Differences in physiological responses between the 3 locomotion types at each slope were first analyzed by a 1-way analysis of variance. In case of significance, Student's paired samples 2-tailed t-test was applied twice to test for differences between the 2 pole lengths and between Nordic walking (with self-selected pole length) and ordinary walking. The corresponding differences in comfort were evaluated by a Wilcoxon matched pairs test. The relative exercise intensity during Nordic walking with self-selected pole length ranged between approximately 44 and 87% of the maximal oxygen uptake across the different slopes. For comparison, it ranged between approximately 29 and 80% during ordinary walking. Uphill Nordic walking with short poles compared with poles of self-selected length caused 3% greater energy expenditure. Notwithstanding, comfort was similar. Horizontally and downhill energy expenditure and comfort were similar between pole lengths. Compared with ordinary walking, Nordic walking required as much as 67% greater energy expenditure. Comfort was similar for ordinary and Nordic walking for each slope. In conclusion, shorter poles caused greater energy expenditure during uphill Nordic walking, whereas comfort was similar to poles of self-selected length. The substantially enhanced energy expenditure of Nordic walking compared with previous studies reflects the vigorous technique used here.

Investigation of Auxiliary Poles Design Criteria on Reduction of End Effect of Detent Force for PMLSM

The detent force in permanent magnet linear synchronous motor (PMLSM) is caused by the attraction between the permanent magnet (PM) and the iron core without input current. It can be divided into two components: the slot effect and the end effect. This paper proposes a novel technique to reduce the end effect of detent force using auxiliary poles. To investigate the auxiliary poles design criteria, we analyze the characteristics of the detent force according to the height, length, and position of the auxiliary poles by using the 2-D finite-element method (FEM). The numerical calculations and the experimental results prove that this proposed technique has a good effect on the reduction of the end effect of detent force.

Development of a small-size superconducting bulk magnet system especially designed for a pulsed-field magnetization

We developed a small superconducting bulk magnet system that was especially designed for a pulsed-field magnetization. The industrial applications of bulk magnets demand the miniaturization of the magnet apparatus as well as the enhancement of the magnetic field. A Gifford-McMahon cycle helium refrigerator with the ultimate temperature of 13 K at the 2nd stage was adopted, and a GdBa 2Cu 3O 7− x bulk material of 60 mm diameter and 20 mm thickness reinforced by a stainless steel ring was located on a cold stage. The total length of the magnetic pole was 570 mm including the refrigerator, therefore, the system could easily be managed. A cooling test and a magnetizing test were carried out using a Hall sensor and thermocouples adhered on the top surface of the material. In the cooling test, the value of 22.5 K at the cold stage was achieved in 3 h. In the magnetizing test, five successive pulsed-fields of the same strength were applied while changing the applied field, and the time responses of the trapped flux density and temperature were measured at each stage. When a magnetic field of 6.97 T was applied, the trapped field reached 2.04 T, which is the highest ever reported for a pulsed-field magnetization of ϕ60 mm class bulk material.

Energy Expenditure And Comfort During Nordic Walking And Ordinary Walking

It is a characteristic of Nordic Walking that energy expenditure is greater during this fitness activity than during ordinary walking. As much as 23% greater energy expenditure has been reported. The amount of extra energy expenditure during Nordic Walking most likely depends on how vigorously the Nordic Walking is performed. However for another important characteristic of fitness exercise, it is unknown how comfort compares for Nordic Walking and ordinary walking. PURPOSE: To compare energy expenditure and comfort during Nordic Walking and ordinary walking. METHODS: Twelve participants (mean±SEM: 171.5±1.5 cm, 67.0±2.7 kg, 50.6±2.4 years, maximal oxygen uptake of 43.4±2.8 ml kg-1 min-1) performed 6-min bouts of uphill (12°), downhill (12°), and horizontal Nordic Walking as well as ordinary walking on a motorized treadmill with their preferred pole length of 67.6±0.6% of body height. Energy expenditure was calculated from measured oxygen uptake while comfort was self-rated on a 1- to 10-point scale where 1 and 10 corresponded to "very, very uncomfortable" and "very, very comfortable", respectively. RESULTS: Nordic Walking required as much as 65±12% greater energy expenditure (p<0.05) than ordinary walking with the greatest difference observed for the horizontal condition. During uphill and downhill conditions, energy expenditure for Nordic Walking was 8±2% and 55±12% higher, respectively (p<0.05). Nevertheless, comfort was similar for the two types of locomotion for each slope (p>0.05). Illustrating the peculiarity of Nordic Walking, comfort was 7.3±0.6 at the same time as participants exercised at more than 85% of their maximal oxygen uptake during uphill Nordic Walking. CONCLUSION: Comfort responses were generally high and at the same time similar for Nordic Walking and ordinary walking for each slope condition despite greater energy expenditure during Nordic Walking. The substantially larger energy expenditure of Nordic Walking compared to previous studies reflects the particularly vigorous Nordic Walking technique used here. From a physical activity and public health perspective it is noteworthy that Nordic Walking (vs. other forms of physical activity, e.g. running) is comfortable and apparently gentle on the body for many people, even when performed at a considerable cardiovascular load.

Improved Design of Embedment Depths for Transmission Pole Foundations Subject to Lateral Loading

Self-supported direct-embedded poles are widely used by the utility industry in the United States to support high-voltage transmission lines. For a typical transmission pole, the lateral loads caused by wind and ice loadings govern the design of the pole and foundation. Recent research findings reveal that the methods used in current practice do not yield consistently reliable pole foundation embedment depths in all soil types and for all possible pole classes, lengths, species, and pole loading scenarios. In order to generate improved design methods for transmission pole foundations, validated methods for analyzing laterally loaded piles have been incorporated into the current study. New reliable methods to design safe and cost-effective transmission pole foundations, incorporating both soil and pole properties, are proposed and recommendations are made in rigorous and simplified forms such that they can be easily adopted for use in the utility industry. This study found that the current methods for dete...

대시포트형 MR유체 마운트의 자극설계에 관한 연구

본 연구에서는 MR 유체를 특징으로 하는 대시포트형 마운트를 제안하고, 제안된 MR유체 마운트의 동적지 배방정식을 구하였다. 또한, 자극의 구조 및 형상과 관련된 설계인자의 변화가 솔레노이드에서의 자계 발생에 미치는 영향에 대하여 관찰하였다 솔레노이드에서 발생하는 자기 특성에 대하여 살펴보기 위하여 자극의 유효길이와 코어 중심부의 구조를 달리하여 설계인자로 선정하였다. 등가자기회로법를 이용하여 솔레노이드에서의 자기 특성의 변화를 살펴보고, 이를 상용소프웨어에 의한 계산 결과와 비교하였다. 등가자기회로법에 의한 계산 결과, 자극의 유효길이가 증가할수록 자기저항은 감소하여 자속밀도가 증가하는 경향을 나타내지만, 그 밖의 자기 특성의 변화는 작게 나타났다. 상용 소프트웨어를 이용한 결과와 등가자기회로에 의한 결과는 유사한 경향을 나타내는 것을 확인하였다. This research proposed a dashpot type mount design using MR fluids, and derived governing equation of the proposed design considering the design parameters of the mount and the Bingham characteristics of MR fluids, which affect the damping forces of the dashpot MR fluid mount. In odor to observe the change of magnetic properties which occurs from the solenoid, the effective length of the magnetic pole and the structure of core are selected as design parameters. The magnetic field quality is calculated in compliance with an equivalent magnetic circuit method. When the effective length of pole increases, the magnetic resistance of the pole of the MR mount decreased, and the magnetic flux density is increased. The result which uses a commercial business software and the result in compliance with equivalent magnetic circuit method shows the tendency which is similar.

Vertical Scar Reduction Mammaplasty: The Fate of Nipple-Areola Complex Position and Inferior Pole Length

Vertical Scar Reduction Mammaplasty: The Fate of Nipple-Areola Complex Position and Inferior Pole Length

Vertical Scar Reduction Mammaplasty: The Fate of Nipple-Areola Complex Position and Inferior Pole Length

A major advantage of vertical scar reduction mammaplasty is the improved long-term projection of the breasts. In their experience with more than 1700 cases, the authors have observed the following important trends: Postoperatively, the nipple-areola complex is located higher than one would predict from the preoperative skin markings, and pseudoptosis does not occur. This study was performed to provide objective measurements to confirm these observations. Forty-nine consecutive women had the following measurements taken of their right breast preoperatively and on postoperative day 5: distance from the clavicle to the superior border of the nipple-areola complex; the clavicle to the nipple; and the inframammary crease to the inferior border of the nipple-areola complex. Forty-six women were available for follow-up at 4 years, and measurements were repeated. Compared with preoperative skin markings, the nipple-areola complex was located on average 1.3 cm higher on postoperative day 5 and 1.0 cm higher at 4-year follow-up. The average distance from the inframammary crease to the inferior border of the nipple-areola complex had decreased 0.4 cm at 4-year follow-up. Compared with preoperative skin markings, the nipple-areola complex was located significantly higher at both early and long-term follow-up. The authors have adjusted their skin marking technique so that the superior border of the nipple-areola complex is marked at the level of the inframammary crease. At 4 years, the distance from the inframammary crease to the inferior border of the nipple-areola complex was significantly shorter, and pseudoptosis did not occur after vertical scar reduction mammaplasty.

Evaluation of the Effects of Relationships Between Main Spatial Lower Pole Calyceal Anatomic Factors on the Success of Shock-Wave Lithotripsy in Patients with Lower Pole Kidney Stones

To evaluate the effects of lower pole calyceal anatomy on lower pole stone clearance after shock-wave lithotripsy (SWL). A total of 133 patients who had single lower pole radio-opaque stones treated with SWL alone and who became stone-free or had clinically insignificant residual fragments (CIRF) were included in the study. Pre-shock-wave lithotripsy intravenous urograms were used to determine the lower pole infundibular width and length, lower pole infundibulopelvic (LPIP) angle, caliceal pelvic height (CPH), and lower infundibular length-to-width ratio. In addition, to evaluate the relationship between LPIP and CPH, a more simple alternative measurement instead of LPIP angle, called the parenchyma-to-ureter distance (PUD), was suggested. The correlation between LPIP and PUD was then examined, and a good correlation was found between these values (P <0.000, r = 0.64). The PUD/CPH ratio was also calculated. The stone-free rate was 62%. According to the cutoff points, the lower infundibular length-to-width ratio and PUD/CPH ratio were different in the stone-free and CIRF groups by univariate analysis but not by multivariate analysis. None of the anatomic factors had a statistically significant effect in predicting the success of SWL in patients with lower pole stones. Nevertheless, evaluation of relationships between lower pole anatomic factors may offer some help in reaching a more accurate interpretation of lower pole stone clearance after SWL.

The influence of the lower patellar pole in the pathogenesis of chronic patellar tendinopathy

Resection of the lower patellar pole provides good results in the treatment of jumper's knee. Therefore we hypothesized that the length of the lower patellar pole is increased in patients with chronic patellar tendinopathy. Cohort study, level of evidence 2. Between 2000 and 2005, 25 patients with chronic patellar tendinopathy underwent conservative and surgical treatment in our clinic. All of them had preoperative MRI were three independent examiners measured the Caton Index, the length and the ratio of the articular and non-articular patellar surface, tendon length and thickness and the thickness and length of the hypodens lesions in the patellar tendon. The measurements were compared with 50 MRI of a control group with no clinical patellofemoral disorders or patellar tendinopathy. Significant changes in tendon thickness (9.42+/-2.87 vs. 4.88+/-1.13; P<0.0001), a longer non-articular surface of the patella (10.62+/-2.86 vs. 7.098+/-2.53; P<0.0001) and significant higher ratio between the articular and the non-articular patellar surface (0.32 vs. 0.24; P<0.0001) were found in the jumper's knee group. No significant changes were seen in the length of the articular surface or the Caton Index. The development of chronic patellar tendinopathy in athletes might be associated with a longer lower patellar pole as patients with jumper's knee showed a longer non-articular patellar surface compared with the control group.

Influence of the moment exerted by the athlete on the pole in pole-vaulting performance

Current studies on pole-vaulting focus mostly on energy transfer data [ Ekevad, M., Lundberg, B., 1995. Simulation of “smart” pole vaulting. Journal of Biomechanics 28, 1079–1090; Ekevad, M., Lundberg, B., 1997. Influence of pole length and stiffness on the energy conversion in pole-vaulting. Journal of Biomechanics, 30, 259–264; Linthorne, N.P., 2000. Energy loss in the pole vault take-off and the advantage of the flexible pole. Sports Engineering 3, 205–218; Schade, F., Arampatzis, A., Bruggemann, G.P., 2006. Reproducibility of energy parameters in the pole vault. Journal of Biomechanics 39, 146–147.] and often fail to take into account the actions exerted on the pole [ Arampatzis, Schade, Bruggemann, 2004. Effect of the pole–human body interaction on pole-vaulting performance. Journal of Biomechanics 37, 1353–1360]. The present study integrates the 3D kinematics data of the athlete but also the actions measured at the end of the pole in the planting box and on the track during the last stride before take-off. It proposes a mechanical model allowing determination of the pole-vaulter's actions on the pole. The model is based on a global mechanical approach. The pole-vaulter's action on his upper and lower hand is concentrated on one middle point to solve the dynamics problem. The model was applied to seven experienced pole-vaulters. The force and the moment exerted on the pole by the pole-vaulter during the last stride before take off and during jump stage, were calculated. This analysis of the compressive force and bending moment for seven pole-vaulters helps to highlight the impact of the moment in the performance. The conclusion is confirmed by an additional comparative study carried out on two pole-vaulters, with comparable morphologies and performing with the same pole.

The Lasting Calculation Optimization for Wood Poles in Power Lines Designing

Power lines in company „Latvenergo” are designed by program STAAD-111. Information involved in program contains data about the length of wood poles, wood poles strength rate, space between wood poles, the region of wind where the designed power line is intended to be exploited, the division of wood poles in the investigation stages where the data about strength parametrs are needed, the type of wires, the wood pole density, the wood pole module of flexibility . Following parameters are calculated: the support connection reactions, shear resistance, twist moment, bending tension and combined tension. After the analyses of results the assumptive load is applied on wood poles in three- dimension plane is determined. For power lines design optimization there are offered: ? the calculation data based on experimentally obtained wood strength parametrs; ? the statistical appreciation and strength parameters estimation model which is based on technological process distribution into control points; ? the calculation algorithm for the project programm STAAD-111 based on experimentally obtained wood strength parametrs.

Variable Permanent Magnet Quadrupole

A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with phi20 mm bore diameter, phi100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments

Reduction of field through read element using shorter read shield

Values for field through the read element (Hread) in longitudinal and perpendicular magnetic recording are compared with the aid of three-dimensional (3d) finite element models. We show that the Hread of the single-pole-type head used in perpendicular magnetic recording (PMR) was larger than that of the inductive ring head used in longitudinal magnetic recording (LMR). This is because that the medium for a PMR system includes a soft under layer (SUL). The Hread of PMR is affected by the permeability and thickness of SUL. The characteristic length of the upper and lower shield layers at which the Hread starts to decrease is found to be roughly equal to the length of the return pole. Decreasing the length of the upper and lower shield is shown to be the most practicable and effective way to realize the reduction of Hread.

Spindle Pole Organization inDrosophilaS2 Cells by Dynein,Abnormal SpindleProtein (Asp), and KLP10A

Dynein is a critical mitotic motor whose inhibition causes defects in spindle pole organization and separation, chromosome congression or segregation, and anaphase spindle elongation, but results differ in different systems. We evaluated the functions of the dynein-dynactin complex by using RNA interference (RNAi)-mediated depletion of distinct subunits in Drosophila S2 cells. We observed a striking detachment of centrosomes from spindles, an increase in spindle length, and a loss of spindle pole focus. RNAi depletion of Ncd, another minus-end motor, produced disorganized spindles consisting of multiple disconnected mini-spindles, a different phenotype consistent with distinct pathways of spindle pole organization. Two candidate dynein-dependent spindle pole organizers also were investigated. RNAi depletion of the abnormal spindle protein, Asp, which localizes to focused poles of control spindles, produced a severe loss of spindle pole focus, whereas depletion of the pole-associated microtubule depolymerase KLP10A increased spindle microtubule density. Depletion of either protein produced long spindles. After RNAi depletion of dynein-dynactin, we observed subtle but significant mislocalization of KLP10A and Asp, suggesting that dynein-dynactin, Asp, and KLP10A have complex interdependent functions in spindle pole focusing and centrosome attachment. These results extend recent findings from Xenopus extracts to Drosophila cultured cells and suggest that common pathways contribute to spindle pole organization and length determination.