Journal articles on the topic 'Wedge position'
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Trow, M. W., J. S. Lapington, and R. D. Bentley. "Position sensitive detector with wedge-and-wedge readout." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 310, no. 1-2 (December 1991): 344–47. http://dx.doi.org/10.1016/0168-9002(91)91056-2.
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Bridges, EJ, SL Woods, GL Brengelmann, P. Mitchell, and D. Laurent-Bopp. "Effect of the 30 degree lateral recumbent position on pulmonary artery and pulmonary artery wedge pressures in critically ill adult cardiac surgery patients." American Journal of Critical Care 9, no. 4 (July 1, 2000): 262–75. http://dx.doi.org/10.4037/ajcc2000.9.4.262.
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BACKGROUND: Despite demonstrated benefits of lateral positioning, critically ill patients may require prolonged supine positioning to obtain reproducible hemodynamic measurements. OBJECTIVES: TO determine the effect of 30 degree right and left lateral positions on pulmonary artery and pulmonary artery wedge pressures after cardiac surgery in critically ill adult patients. METHODS: An experimental repeated-measures design was used to study 35 patients with stable hemodynamics after cardiac surgery. Subjects were randomly assigned to 1 of 2 position sequences. Pulmonary artery and pulmonary artery wedge pressures were measured in each position. RESULTS: Measurements obtained from patients in the 30 degree left lateral position differed significantly (all Ps < .05) from measurements obtained from patients in the supine position for pulmonary artery systolic, end-diastolic, and mean pressures. Pulmonary artery wedge pressures did not differ significantly; however, data were available from only 17 subjects. The largest mean difference in pressures between the 2 positions was 2.0 +/- 2.1 mm Hg for pulmonary artery systolic pressures, whereas maximum differences for end-diastolic and pulmonary artery wedge pressures were 1.4 +/- 2.7 mm Hg and 1.6 +/- 2.4 mm Hg, respectively. Clinically significant position-related changes in pressure occurred in 12 (2.1%) of 581 pressure pairs. Clinically significant changes occurred in end-diastolic pressure in 2 subjects and in pulmonary artery wedge pressure in 1 subject. CONCLUSiONS: In patients with stable hemodynamics during the first 12 to 24 hours after cardiac surgery, measurements of pulmonary artery and pulmonary artery wedge pressures obtained in the 30 degree lateral and supine positions are clinically interchangeable.
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Ikeda, Andrea J., John R. Fergason, and Jason M. Wilken. "Effects of altering heel wedge properties on gait with the Intrepid Dynamic Exoskeletal Orthosis." Prosthetics and Orthotics International 42, no. 3 (September 4, 2017): 265–74. http://dx.doi.org/10.1177/0309364617728116.
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Background: The Intrepid Dynamic Exoskeletal Orthosis is a custom-made dynamic response carbon fiber device. A heel wedge, which sits in the shoe, is an integral part of the orthosis-heel wedge-shoe system. Because the device restricts ankle movement, the system must compensate to simulate plantarflexion and allow smooth forward progression during gait. Objectives: To determine the influence of wedge height and durometer on the walking gait of individuals using the Intrepid Dynamic Exoskeletal Orthosis. Study design: Repeated measures. Methods: Twelve individuals walked over level ground with their Intrepid Dynamic Exoskeletal Orthosis and six different heel wedges of soft or firm durometer and 1, 2, or 3 cm height. Center of pressure velocity, joint moments, and roll-over shape were calculated for each wedge. Results: Height and durometer significantly affected time to peak center of pressure velocity, time to peak internal dorsiflexion and knee extension moments, time to ankle moment zero crossing, and roll-over shape center of curvature anterior-posterior position. Wedge height had a significant influence on peak center of pressure velocity, peak dorsiflexion moment, time to peak knee extension moment, and roll-over shape radius and vertical center of curvature. Conclusion: Changes in wedge height and durometer systematically affected foot loading. Participants preferred wedges which produced ankle moment zero crossing timing, peak internal knee extension moment timing, and roll-over shape center of curvature anterior-posterior position close to that of able-bodied individuals. Clinical relevance Adjusting the heel wedge is a simple, straightforward way to adjust the orthosis-heel wedge-shoe system. Changing wedge height and durometer significantly alters loading of the foot and has great potential to improve an individual’s gait.
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Chen, Le Ping, Xue Dao Shu, Wen Fei Peng, and Bao Shou Sun. "Mechanism Research on Multi-Wedge Synchrostep Rolling Asymmetric Shaft-Parts by Cross-Wedge Rolling." Applied Mechanics and Materials 201-202 (October 2012): 1061–65. http://dx.doi.org/10.4028/www.scientific.net/amm.201-202.1061.
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Because most of the asymmetric shaft-parts have relatively large size in the axial direction, single-wedge cross-wedge rolling (CWR) exposes many imperfections, such as the huge roller, higher cost etc. The paper adopted finite element method (FEM) to simulate multi-wedge synchrostep CWR (MS-CWR) based on the typical asymmetric shaft-part, and gained its distribution and characteristics of stress and strain. In the knifing stage, the deformation of work piece only emerges on the local region, but in the stretching stage, most of regions are observed the deformation except two ends of the billet and the transition position between inner and outer wedge of multi-wedges. The results offer theoretical basis for promoting and applying MS-CWR technology on asymmetric shaft-parts.
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Kostaschuk, R. A., and L. A. Atwood. "River discharge and tidal controls on salt-wedge position and implications for channel shoaling: Fraser River, British Columbia." Canadian Journal of Civil Engineering 17, no. 3 (June 1, 1990): 452–59. http://dx.doi.org/10.1139/l90-049.
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Salinity and current surveys in the Main Channel of the Fraser River estuary, British Columbia, show that a well-defined salt-wedge intrusion migrates along the channel. Bivariate statistical analyses reveal that when discharge is nearly constant, the position of the salt-wedge is controlled by tidal height. Multivariate analyses of data with large ranges in discharge and tidal height indicate that intrusion location is a function of both discharge and tides. Multiple regression models provide predictive relations for salt-wedge position. Application of a regression model indicates that channel shoaling at the mouth of the river is related to the low-tide position of the salt-wedge. Key words: Fraser River estuary, salt-wedge position, channel shoaling.
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Lin, Jing, Chen-Yuan Bai, and Zi-Niu Wu. "Study of asymmetrical shock wave reflection in steady supersonic flow." Journal of Fluid Mechanics 864 (February 13, 2019): 848–75. http://dx.doi.org/10.1017/jfm.2019.18.
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The asymmetrical Mach reflection configuration is studied analytically in this paper, using an asymmetrical model extended from a recent symmetrical model and accounting for the new features related to asymmetry of the two wedges. It is found that the two sliplines do not turn parallel to the incoming flow at the same horizontal location and the sonic throat locates at the position where the difference of slopes of the two sliplines vanishes. This allows us to define a new sonic throat compatibility condition essential to determine the size of the Mach stem. The present model gives the height of the Mach stem, declined angle of the Mach stem from vertical axis, sonic throat location and shape of all shock waves and sliplines. The accuracy of the model is checked by computational fluid dynamics (CFD) simulation. It is found that the Mach stem height is strongly dependent on asymmetry of the wedge angles and almost linearly dependent on the asymmetry of the wedge lower surface lengths. The Mach stem height is shown to be insensitive to the asymmetry of the horizontal positions of the two wedges. The mechanisms for these observations are explained. For instance, it is demonstrated that the Mach reflection configuration remains closely similar when there is horizontal shift of either wedge.
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Thomas, S. J., and R. L. Thomas. "Variation of linear accelerator wedge factors with field size and wedge position." British Journal of Radiology 66, no. 786 (June 1993): 567–68. http://dx.doi.org/10.1259/0007-1285-66-786-567-c.
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Dean, E. M., and J. B. Davis. "Variation of linear accelerator wedge factors with field size and wedge position." British Journal of Radiology 66, no. 786 (June 1993): 569. http://dx.doi.org/10.1259/0007-1285-66-786-569.
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Seo, Jungkun. "Wedge-issue dynamics and party position shifts." Party Politics 17, no. 6 (August 9, 2010): 823–47. http://dx.doi.org/10.1177/1354068810376184.
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Even when the stakes of party-building are high, political parties often find their members divided over a key policy position. In post-Reconstruction America, the hot-button issue of excluding Chinese immigrant workers strengthened Democratic cohesion while splitting the ‘party of Lincoln’. Previous research has not completely investigated the role of party competition and cohesiveness in paving the way for passage of the Chinese exclusion laws. In this investigation of the legislative politics of banning the Chinese from 1879 to 1882, it is found that cross-pressured members sometimes facilitate party transformation. The evidence demonstrates that partisan responses to potential wedge issues are a previously unnoticed source of explanation of eventual party position changes.
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Zhang, Hanmin, Ming Hu, Fei Zong, Baoguan Yin, Denghong Ye, Qingchun He, and Zhijie Wang. "Wafer damage issue study by heavy Al wire wedge bonding." Microelectronics International 31, no. 2 (April 29, 2014): 129–36. http://dx.doi.org/10.1108/mi-10-2013-0048.
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Purpose – The purpose of this paper was to attempt to confirm the root cause of wafer damage issue by heavy Al wire wedge bonding and propose some permanent solutions for it. Design/methodology/approach – The infra red–optical beam-induced resistance change (IR-OBIRCH) analysis defines the position of an abnormal hotspot. A cross section and an scanning electron microscope (SEM) confirmed the wafer damage issue and its position. Based on the position of wafer damage, the wedge tool with different life and Al buildup was checked found to be on the wedge tool. Finite element analysis (FEA) modeling analysis and simulation experiment guarantee the Al buildup, and low wedge deformation thickness (WDT) can cause the wafer damage issue. Finally, design of experiment (DOE) experiments are designed to optimize wedge tool dimension and wedge-bond parameters to eliminate wafer damage issue. Findings – Wafer damage issue caused the Vpwr-OUTPUT leakage issue by IR-OBIRCH analysis. Al buildup was found on wedge tool with different life and its size gets larger along with the increase in wedge tool life. Low WDT and bigger Al buildup can cause the wafer damage. Designing new wedge tool and parameters optimization can increase WDT. Research limitations/implications – Because of the limitation of time and resources, finite element method (FEM) modeling and wedge tool dimension could not be studied more deeply. Originality/value – This paper sets an example on how to find out the root cause of wafer damage by a step-by-step analysis and put forward a quick solution accordingly for the issue.
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Ema, S., and E. Marui. "Chucking Performance of a Wedge-Type Power Chuck." Journal of Engineering for Industry 116, no. 1 (February 1, 1994): 70–77. http://dx.doi.org/10.1115/1.2901811.
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In order to improve the chucking performance of a wedge-type power chuck with three top jaws, bending tests, chucking accuracy tests, and cutting tests in the chuck-work system were performed using top jaws with different inner diameters, gripping positions, and taper angles. Bending stiffness, eccentricity of a workpiece, and cutting stability of the chuck were assessed using variance analysis. The inner diameter and the taper angle are effective to increase the bending stiffness; however, the gripping position is generally ineffective. With respect to the chucking accuracy, the effects of the inner diameter and the taper angle are significant; however, the effect of the gripping position is insignificant. Top jaws with tapered gripping parts are effective for limiting chatter vibration in actual use. Therefore, for the wedge-type power chuck used in the experiment, the use of the top jaws with tapered gripping parts is the most effective.
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Miller, M. K. "A Transparent Anode Array Detector for 3d Atom Probes." Microscopy and Microanalysis 4, S2 (July 1998): 80–81. http://dx.doi.org/10.1017/s1431927600020523.
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In a three dimensional atom probe, the identity and spatial coordinates of the atoms field evaporated from the specimen are determined. Their identity is calculated from the flight time from the specimen to the single atom detector. The x and y coordinates of the atom in the specimen are determined from the coordinates of its impact position on the position-sensitive detector and the z coordinate is determined from its position in the evaporation sequence. These data may then be reconstructed to visualize and quantify the distribution of all the elements in the specimen. Several types of position-sensitive detectors have been used including a wedge-and-strip detector (position-sensitive atom probe), a 10 by 10 array of anodes (tomographic atom probe), and a gateable CCD camera (optical atom probe). The wedge-and strip and the CCD camera detectors both suffer from the limitation that if more than one atom strikes the detector on a field evaporation pulse then the impact positions cannot be determined in many cases.
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Budantseva, Nadine Arkad'evna, and Yurij Kirillovich Vasil'chuk. "Ratio of isotopic parameters δ2H-δ18o in Late Pleistocene and Holocene ice wedge." Арктика и Антарктика, no. 3 (March 2021): 19–43. http://dx.doi.org/10.7256/2453-8922.2021.3.36636.
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The subject of this research is the ratio of isotopic parameters of deuterium of heavy oxygen in ice wedges. The authors considered such parameter as inclination of the line of the ration of deuterium of heavy oxygen in ice wedges. Proximal to GMLV (or LLMV) position of isotope values for ice wedge and inclination of the line proximate to 8 suggests that the ice wedge was formed from atmospheric precipitation (winter snow). The article provides separate examples of anomalous deuterium ratios of heavy oxygen with very low ration of line inclination, which in combination with the abnormally low dexc values indicate the indicate isotopic fractionation processes in snow before melting and/or melting snow water before filling frost-cutting cracks. Three author determines the three main types of ratios of deuterium m of heavy oxygen content in ice wedge: a) normal ratio δ2H-δ18O (with line inclination of the ratio proximate to GLMV or LLMW). b) ratio of deuterium of heavy oxygen to deviation from GLMV or LLMW (with signs of change in the primary isotope signal of atmospheric precipitation), c) anomalous ratio of deuterium of heavy oxygen. It is shown that the first two types are characteristic to most ice wedge under study in the vast part of the Russian cryolithozone from the European North to the east of Chukotka; the third type is obtained for several Holocene ice wedge in Transbaikal and upper Yenisei River. This may be explained by significant isotope transformation of snow cover in the conditions of distinctly continental climate.
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POWER, C. K., S. E. MARSHALL, D. M. PHELAN, and C. M. BURKE. "Pulmonary artery catheter: arterialisation of aspirated wedge blood confirms the wedge position in pulmonary hypertension." Clinical Intensive Care 7, no. 1 (February 1996): 39–41. http://dx.doi.org/10.3109/tcic.7.1.39.41.
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Earhart, Gammon M., and Amy J. Bastian. "Selection and Coordination of Human Locomotor Forms Following Cerebellar Damage." Journal of Neurophysiology 85, no. 2 (February 1, 2001): 759–69. http://dx.doi.org/10.1152/jn.2001.85.2.759.
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We have previously shown that control subjects use two distinct temporal strategies when stepping on an inclined surface during walking: one for level and 10° surfaces and another for 20 and 30° surfaces. These two temporal strategies were characterized by systematic shifts in the timing of muscle activity and peak joint angles. We examined whether cerebellar subjects with mild to moderate gait ataxia were impaired in their ability to select these two temporal strategies, adjust peak joint angle amplitudes, and/or adjust one joint appropriately with respect to movements and constraints at another joint. Subjects walked on a level surface and on different wedges (10, 20, and 30°) presented in the context of level walking. In a single trial, a subject walked on a level surface in approach to a wedge, took a single step on the wedge, and continued walking on an elevated level surface beyond the wedge. Cerebellar subjects used two temporal strategies, one for the level and 10° surfaces and another for 20 and 30° surfaces. Cerebellar strategies were similar to those used by controls except for the timing of ankle-joint movement on the steeper wedges. Cerebellar subjects adjusted the peak amplitudes of individual joint angles normally, with the exception of peak ankle plantarflexion. However, they exhibited greater trial-to-trial variability of peak hip and knee joint angles that increased as a function of wedge inclination. The most substantial deficit noted in the cerebellar group was in the relative movement of multiple joints. Cerebellar subjects demonstrated multijoint coordination deficits in all conditions, although these deficits were most pronounced during stance on the steeper wedges. On the 30° wedge, cerebellar subjects showed abnormal relative movement of hip, knee, and ankle joints and the most substantial decomposition of movement. We speculate that to simplify multijoint control, cerebellar subjects decomposed their movement by fixing the ankle joint in a dorsiflexed position on the steepest wedges. Our results suggest that the cerebellum may not be critical in selecting the basic motor patterns for the two temporal strategies because cerebellar subjects produced appropriate timing shifts at most joints. Instead, our data suggest that the cerebellum is most critical for adjusting the relative movement of multiple joints, especially to accommodate external constraints.
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Seo, Jeong-Hwa, Chul-Woo Jung, and Jae-Hyon Bahk. "Uppermost Blood Levels of the Right and Left Atria in the Supine Position." Anesthesiology 107, no. 2 (August 1, 2007): 260–63. http://dx.doi.org/10.1097/01.anes.0000270720.67307.fa.
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Background To eliminate the influence of hydrostatic pressure, proper transducer positions for central venous pressure and pulmonary artery wedge pressure are at the uppermost blood levels of right atrium (RA) and left atrium (LA). This study was performed to investigate accurate reference levels of central venous pressure and pulmonary artery wedge pressure in the supine position. Methods Chest computed tomography images of 96 patients without history of cardiothoracic surgery, heart disease, or cardiothoracic anatomical abnormality were retrospectively reviewed. The anteroposterior (AP) diameter of the thorax and the vertical distances from the skin on the back to the most anterior portion of RA (RA height) and LA (LA height) were measured. Their ratios were abbreviated, respectively, as RA height/AP diameter and LA height/AP diameter. Data are expressed as mean +/- SD (range). Results There was a significant difference [4.6 +/- 1.0 (1.6-6.4) cm; P < 0.001] between RA and LA heights. AP diameter was positively correlated with RA and LA heights (R = 0.839 and 0.700, respectively; P < 0.001). There was also a significant difference between RA height/AP diameter [0.83 +/- 0.03 (0.71-0.91)] and LA height/AP diameter [0.62 +/- 0.04 (0.52-0.72)] (P < 0.001). Conclusion In the supine position, a central venous pressure transducer should be positioned approximately 4.6 cm higher than a pulmonary artery wedge pressure transducer. The external reference level for central venous pressure seems to be at approximately four fifths of the AP diameter of the thorax from the back, and that for pulmonary artery wedge pressure seems to be at approximately three fifths of the AP diameter.
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Negi, Takahiro, Takashi Suda, Sachiko Tochii, and Yasushi Hoshikawa. "Subxiphoid uniportal bilateral lung wedge resection." European Journal of Cardio-Thoracic Surgery 58, Supplement_1 (June 29, 2020): i100—i102. http://dx.doi.org/10.1093/ejcts/ezaa169.
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Abstract Subxiphoid uniportal bilateral lung wedge resection, in which all manipulations are performed via a 3-cm wound positioned below the xiphoid process, can be performed in the supine position without the patient having to change positions. It also enables one-stage bilateral lung resection. We report the surgical procedure and initial results of subxiphoid uniportal bilateral lung wedge resection. A 3-cm transverse incision was made 1 cm caudally below the xiphoid process. A port for uniportal surgery was inserted. After CO2 insufflation at 8 mmHg, the lung was grasped and lifted with bent grasping forceps, and by bending the tip of a stapler, the surgeon resected the affected portion of the bilateral lungs. In this approach, there is one incision, no intercostal nerve damage and bilateral surgery can be performed in the same procedure; therefore, the technique may have the benefit of lesser invasiveness for the patient. Furthermore, a detailed comparison of subxiphoid uniportal bilateral lung wedge resection with the one-stage lateral intercostal approach with a larger subject sample is needed.
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ZhiJie, Wang, Tony Lim, Jiang YingWei, Zhang ChangLiang, Haengsun Choi, and Kwansun Hwang. "2 mils Au wire interchip wedge bond cratering study." International Symposium on Microelectronics 2010, no. 1 (January 1, 2010): 000479–85. http://dx.doi.org/10.4071/isom-2010-wa4-paper4.
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Au wire thermosonic wedge bonding is applied for die to die interconnect on accelerometer device. With the fragile bond pad structure of MEMS device, bond pad cratering or bond pad metal peel is a fatal wedge bond defect during assembly packaging and reliability failure during field application. Typical interchip wedge bond failure mode and the cause of failures are studied through analyzing wedge bonding mechanism, packaging & tooling design and bond pad metallization. Comprehensive wedge bond process characterization was carried out to improve wedge bond quality and reliability. Critical wedge bond responses (wedge pull, wedge shear, Cratering) were studied during wedge bond process characterization. Post wedge bond cratering has good correlation with the wedge tool in both position and shape. Si nodule underneath the bond pad metal generates higher local stress to the bond pad during wedge bonding. Thinner bond pad metal could not act as a cushion to mitigate the wedge bond stress to the poly silicon layer beneath the bond pad. The initial post wedge bond cratering / bond pad damage will get deteriorated during following assembly reflow process as well as SMT process, eventually the weakest interface layer beneath the bond pad will be separated, reflected as the bond pad metal peel. Approaches to enhance interchip wedge bond integrity were explored and significant improvements were seen.
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Willemen, M. A., J. L. Lanovaz, H. C. Schamhardt, and Hilary Clayton. "Effects of a Heel Wedge in Horses with Superficial Digital Flexor Tendinitis." Veterinary and Comparative Orthopaedics and Traumatology 13, no. 01 (2000): 01–08. http://dx.doi.org/10.1055/s-0038-1632622.
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SummaryThe objective was to determine whether the use of heel wedges is an appropriate treatment for superficial digital flexor (SDF) tendinitis. The subjects were six warmblood horses in which SDF tendinitis was induced in one forelimb using a collagenase model. The stride characteristics were compared under four conditions: flat shoes; 6° heel wedge following a one hour adaptation; 6° heel wedge following five days adaptation; and one hour after reapplication of flat shoes. Videographic and force data were collected for both forelimbs during the stance phase of the trot, and were combined with morphometric measurements using an inverse dynamics method to calculate net joint moments and joint powers at each of the joints of the forelimbs. Repeated measures ANOVA was used to compare the stride variables across conditions in the lame limb and in the compensating forelimb. Significant kinematic changes in response to the use of heel wedges were confined to the coffin joint which was more flexed due to the more upright orientation of the hoof segment. The onset of breakover was delayed with the hoof wedges. In the compensating limb only, the use of heel wedges was associated with a shift of the net joint moment to the dorsal side of the coffin joint during the first one third of stance. Both forelimbs had significantly smaller peak palmar moments at the coffin joint with heel wedges in the second half of stance, which appeared to be a mechanical consequence of the more flexed position of the coffin joint. Tension was increased in the extensor branches of the suspensory ligament and common digital extensor tendon on the dorsal side, and reduced in the deep digital flexor tendon and its distal accessory ligament on the palmar side. Less energy was absorbed across the coffin joint in both limbs with heel wedges. The study did not reveal changes associated with the use of heel wedges that could be interpreted as a reduction of the effects of lameness due to SDF tendinitis.The objective was to determine whether the application of 60 heel wedges was appropriate for treating horses with superficial digital flexor (SDF) tendinitis. The significant effects of the heel wedges affected the coffin joint and included a more flexed position due to the more upright orientation of the hoof segment, a reduction in the peak palmar moment and less energy absorption across the joint. Since these changes were confined to the coffin joint, they were not interpreted as being beneficial in treating lameness due to SDF tendinitis.
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Kim, Tae Woo, Myung Chul Lee, Jae Ho Cho, Jong Seop Kim, and Yong Seuk Lee. "The Ideal Location of the Lateral Hinge in Medial Closing Wedge Osteotomy of the Distal Femur: Analysis of Soft Tissue Coverage and Bone Density." American Journal of Sports Medicine 47, no. 12 (August 29, 2019): 2945–51. http://dx.doi.org/10.1177/0363546519869325.
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Background: Although an appropriate hinge position to prevent unstable lateral hinge fractures is well established in medial opening wedge high tibial osteotomy, the position during medial closing wedge distal femoral osteotomy has not been elucidated. Purpose/Hypothesis: The purpose was to evaluate the ideal hinge position that would prevent an unstable lateral hinge fracture during biplanar medial closing wedge distal femoral osteotomy based on soft tissue coverage and bone density around the hinge area. The hypothesis was that the ideal hinge position could be clarified by analyzing soft tissue coverage and bone density around the lateral hinge area. Study Design: Controlled laboratory study. Methods: In 20 cadaveric knees (mean age, 70.3 ± 19.2 years), the femoral attachment of the gastrocnemius lateral head was quantitatively analyzed as a soft tissue stabilizer using digital photography and fluoroscopy. Then, medial closing wedge distal femoral osteotomy was performed, locating the lateral hinge either inside (group 1) or outside (group 2) the femoral attachment of the gastrocnemius lateral head, and the incidence of unstable lateral hinge fractures was compared between the 2 groups. Cortical bone density around the lateral hinge was measured using Hounsfield units on 30 computed tomography scans and reconstructed as a 3-dimensional mapping model. The transitional zone with low bone density was regarded as the safe hinge position with an increased capacity for bone deformation. Results: The upper and lower margins of the femoral attachment of the gastrocnemius lateral head were 9.1 ± 0.9 mm above and 8.0 ± 1.4 mm below the upper border of the lateral femoral condyle, respectively, and the femoral attachment of the gastrocnemius lateral head was widest in the anteroposterior dimension 0.4 ± 1.7 mm above the upper border of the lateral femoral condyle. The incidence of unstable lateral hinge fractures during osteotomy was significantly decreased in group 1 compared with group 2 (group 1: 0/10; group 2: 5/10; P = .01). An isolated transitional zone with low bone density was observed in all 30 knees and located 1.3 ± 0.8 mm above the upper border of the lateral femoral condyle. Bone density of the transitional zone with low bone density was significantly lower than surrounding femoral cortices ( P < .001). Conclusion: Only the upper border of the lateral femoral condyle can be recommended as an ideal hinge position to prevent unstable lateral hinge fractures during biplanar medial closing wedge distal femoral osteotomy based on soft tissue coverage and bone density. Clinical Relevance: When the hinge is positioned at the upper border of the lateral femoral condyle during biplanar medial closing wedge distal femoral osteotomy, the risk of unstable hinge fractures can be minimized.
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Thürig, Grégoire, Alexander Korthaus, Jannik Frings, Markus Thomas Berninger, Karl-Heinz Frosch, and Matthias Krause. "Influence of Medial Osteotomy Height and Hinge Position in Open Wedge High Tibial Osteotomy: A Simulation Study." Diagnostics 12, no. 10 (October 20, 2022): 2546. http://dx.doi.org/10.3390/diagnostics12102546.
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(1) Background: In treating medial unicompartmental gonarthrosis, medial open wedge high tibial osteotomy (mOWHTO) reduces pain and is intended to delay a possible indication for joint replacement by relieving the affected compartment. This study aimed to investigate the influence of the osteotomy height with different hinge points in HTO in genu varum on the leg axis. (2) Methods: Fifty-five patients with varus lower leg alignment obtained full-weight bearing long-leg radiographs were analyzed. Different simulations were performed: Osteotomy height was selected at 3 and 4 cm distal to the tibial articular surface, and the hinge points were selected at 0.5 cm, 1 cm, and 1.5 cm medial to the fibular head, respectively. The target of each correction was 55% of the tibial plateau measured from the medial. Then, the width of the opening wedge was measured. Intraobserver and interobserver reliability were calculated. (3) Results: Statistically significant differences in wedge width were seen at an osteotomy height of 3 cm below the tibial plateau when the distance of the hinge from the fibular head was 0.5 cm to 1.5 cm (3 cm and 0.5 cm: 8.9 +/− 3.88 vs. 3 cm and 1.5 cm: 11.6 +/− 4.39 p = 0.012). Statistically significant differences were also found concerning the wedge width between the distances 0.5 to 1.5 cm from the fibular head at the osteotomy height of 4 cm below the tibial plateau. (4 cm and 0.5 cm: 9.0 +/− 3.76 vs. 4 cm and 1.5 cm: 11.4 +/− 4.27 p = 0.026). (4) Conclusion: A change of the lateral hinge position of 1 cm results in a change in wedge width of approximately 2 mm. If hinge positions are chosen differently in preoperative planning and intraoperatively, the result can lead to over- or under-correction.
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Shu, Xue Dao, Wen Ping Liu, Chao Cheng, Zhan Li, Wen Fei Peng, and Bao Shou Sun. "Study on the Regularity of the Center Quality of Cross Wedge Rolling Asymmetric Shaft Parts Based on Parity Wedge." Applied Mechanics and Materials 488-489 (January 2014): 1125–29. http://dx.doi.org/10.4028/www.scientific.net/amm.488-489.1125.
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In order to expand cross wedge rolling technology applications further and improving the quality of asymmetric shaft parts, this paper predicts the position of center defect location of Cross Wedge Rolling asymmetric shaft parts based on Parity Wedge by Normalized C & L criteria. On this basis, it conducted a systematic study on the effect of forming angle on quality of rolling core part. It has found that, during the forming process of Cross Wedge Rolling shaft parts, rolling center region was more prone to damage, and achieved the regularity of process parameters on the quality of core part. The study results lay the theoretical foundation for preventing defects effectively and improving quality of rolling core part.
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Aitken, LM. "Reliability of measurements of pulmonary artery pressure obtained with patients in the 60 degrees lateral position." American Journal of Critical Care 9, no. 1 (January 1, 2000): 43–51. http://dx.doi.org/10.4037/ajcc2000.9.1.43.
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BACKGROUND: Monitoring of pulmonary artery pressure is an essential component of the care of critically ill patients. The conditions under which reliable measurements can be obtained must be clarified. OBJECTIVES: To determine (1) whether reliable measurements of pulmonary artery pressure can be obtained with patients in the right or left 60 degrees lateral position and (2) which characteristics of patients preclude obtaining reliable measurements. METHODS: One hundred five patients (65 cardiac surgery, 40 general medicine) with pulmonary artery catheters were enrolled in a prospective, stratified, quasi-experimental study. Subjects were repositioned from supine (head of bed elevated < 30 degrees with 1 pillow) to the left and right 60 degrees lateral positions. Systolic, diastolic, and mean pulmonary artery pressures and pulmonary capillary wedge pressure were measured before and 5, 10, and 20 minutes after lateral repositioning. The zero reference was the phlebostatic axis when patients were supine and the dependent midclavicular line at the level of the fourth intercostal space when patients were in the lateral positions. RESULTS: In most patients, measurements obtained with patients in the lateral position differed significantly from measurements obtained with patients supine. None of the variables examined were reliable predictors of which patients would have these differences. More than 11% of the patients had clinically significant differences in addition to the statistically significant differences. CONCLUSION: Reliable measurements of pulmonary artery pressure and pulmonary capillary wedge pressure cannot be obtained with patients in the 60 degrees lateral position.
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Li, Zhan, Xue Dao Shu, Wen Fei Peng, and Bao Shou Sun. "Strain Rules of Cross Wedge Rolling Asymmetric Shaft-Parts Based on the Parity Wedge." Applied Mechanics and Materials 201-202 (October 2012): 1066–70. http://dx.doi.org/10.4028/www.scientific.net/amm.201-202.1066.
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The analysising of strain is the key factors to understand the forming mechanism of cross wedge rolling asymmetric shaft. due to the extrusion of dies and other external force, its interior,interactions can cause the relative position between the various parts. In order to study the deformation of workpiece at different degrees, pulling in the finite element strain field analysis, the strain of the analysis at deformation process is also a necessary precondition for forming and stress distribution. In this papre,By using Deform3D platform, the forming process of the cross wedge rolling on parity wedge asymmetric shaft is simulated. It is also to be analyzed the distribution and variation of the amount of strain in the rolling process, it shows that a cross-sectional and longitudinal section about the deformation characteristics of the strain fields, the results can achieve production of cross wedge rolling and provide important theoretical foundation to promote further cross-wedge rolling.
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Thornton, John. "The inter-electrode capacitance of wedge and strip position sensing elements." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 269, no. 1 (June 1988): 226–29. http://dx.doi.org/10.1016/0168-9002(88)90883-2.
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IZAWA, Keisuke, and Yuichi MATSUMURA. "551 Optimal attached position of damping material for wedge-shaped damper." Proceedings of the Dynamics & Design Conference 2011 (2011): _551–1_—_551–7_. http://dx.doi.org/10.1299/jsmedmc.2011._551-1_.
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Zhou, Yuanye, Tianlong See, Shan Zhong, Zhu Liu, and Lin Li. "A massive reduction of dust particle adhesion in a cyclone by the introduction of a wedge." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 17 (September 1, 2017): 3102–14. http://dx.doi.org/10.1177/0954406217728978.
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Particle adhesion in a cyclone, such as a cyclonic vacuum cleaner, can significantly reduce its efficiency. An investigation is presented here on the particle adhesion in a cyclone from a vacuum cleaner that consists of a primary separation stage (a cylindrical chamber) and a secondary separation stage (14 cyclones). The flow direction in the primary separation stage was modified by the use of a wedge of 40 mm × 40 mm × 6 mm at the inlet of the primary separation stage, which affected the particle trajectory in the primary separation stage and the particle inlet position in the cyclone while keeping the air flow direction and velocity (without particles being loaded), the Hamaker constant, particle size and the particle charge unaffected. The particle inlet position in the cyclone was varied from the lower portion (without wedge) to the upper portion (with wedge). Without the wedge, a spiral pattern of particle (plaster particles, average size 1.13 μm) adhesion onto the inner wall of the cyclone was found and a thicker deposited layer of particles at the cyclone tip region was observed. With the introduction of the wedge, the spiral particle adhesion pattern was not observed and a reduction of particle adhered to the inner wall by up to 94% was achieved, although there was an increase in the amount of particles entering the cyclone. This demonstrates almost a complete elimination of particle adhesion onto the cyclone wall, without compromising separation efficiencies.
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Wolfram, Susann, Christopher I. Morse, Keith L. Winwood, Emma Hodson-Tole, and Islay M. McEwan. "Achilles tendon moment arm in humans is not affected by inversion/eversion of the foot: a short report." Royal Society Open Science 5, no. 1 (January 2018): 171358. http://dx.doi.org/10.1098/rsos.171358.
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The triceps surae primarily acts as plantarflexor of the ankle joint. However, the group also causes inversion and eversion at the subtalar joint. Despite this, the Achilles tendon moment arm is generally measured without considering the potential influence of inversion/eversion of the foot during plantarflexion. This study investigated the effect of foot inversion and eversion on the plantarflexion Achilles tendon moment arm. Achilles tendon moment arms were determined using the centre-of-rotation method in magnetic resonance images of the left ankle of 11 participants. The foot was positioned at 15° dorsiflexion, 0° or 15° plantarflexion using a Styrofoam wedge. In each of these positions, the foot was either 10° inverted, neutral or 10° everted using an additional Styrofoam wedge. Achilles tendon moment arm in neutral foot position was 47.93 ± 4.54 mm and did not differ significantly when the foot was positioned in 10° inversion and 10° eversion. Hence, inversion/eversion position of the foot may not considerably affect the length of the Achilles tendon moment arm. This information could be useful in musculoskeletal models of the human lower leg and foot and when estimating Achilles tendon forces during plantarflexion with the foot positioned in inversion or eversion.
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Lac, Choi Young, and Hwang Sun Chul. "The influence of different hinge position on HTO. -comparison of medial open-wedge osteotomy & lateral closed-wedge osteotomy.-." Asia-Pacific Journal of Sports Medicine, Arthroscopy, Rehabilitation and Technology 9 (July 2017): 86–87. http://dx.doi.org/10.1016/j.asmart.2017.05.193.
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Gao, Wen Xue, Wen Long Sun, Hong Liang Deng, and Xi Meng Sun. "Study on Blasting Vibration Effects of Shallow Tunnel Excavation." Advanced Materials Research 250-253 (May 2011): 2366–70. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.2366.
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Based on the practice of Huolang-yu tunnel of Mixing road reconstruction, this paper studies the monitoring of ground surface vibration and the technology of controlled blasting. The results show: (1) the ground surface vibration declines from constructed position to non-excavated areas along tunnel excavation direction. (2) The vibration control of wedge cutting holes blasting is the key to reduce or eliminate shallow tunnel vibrating calamity. And the replacement of the multi-stage small wedge cutting holes to the big wedge cutting holes ameliorates blasting vibration and rock fragmentation. (3) The overall monitoring of shallow tunnel blasting vibration and the effects, and optimum of the blasting design not only reduce blasting vibration but also ensure large circulation footage.
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Cramoysan, M., R. Bunting, and D. Orr. "The use of a model current wedge in the determination of the position of substorm current systems." Annales Geophysicae 13, no. 6 (June 30, 1995): 583–94. http://dx.doi.org/10.1007/s00585-995-0583-0.
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Abstract. We present a technique for determination of the position and extent of the current systems present during substorm breakup. The parameters of a three-dimensional model of the currents are determined by fitting the model to data from the SAMNET magnetometer array, a midlatitude array of seven stations. The model used is a fully 3D current wedge aligned along dipolar field lines, the parameters being the meridians of upward and downward field-aligned currents (FACs), the latitude of the auroral electrojet and the magnitude of current growth over the observation interval. The method is novel in that the three geometrical parameters are first determined with the fourth arrived at via a secondary process. It has been applied to a number of events and appears to make estimates of the longitudes of the FACs consistent with the predictions of previous methods. Since the method employs a fully 3D model of the substorm current wedge as opposed to an idealised 2D model, it is reasonable to place more reliance on the results so obtained. Moreover, the method also has the additional benefit of a prediction of the latitude of the substorm electrojet and the nature of the current growth through the wedge at substorm onset.
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Kraus, Jonathan C., Michael Ziegele, Mei Wang; Brian C. Law, and Glenn G. Shi. "Peak Contact Stress of TMT-1 Joint after Sequential Correction of Hallux Valgus Using a Proximal Opening Wedge Metatarsal Osteotomy (PMO) and Distal Soft Tissue Procedure." Foot & Ankle Orthopaedics 5, no. 4 (October 1, 2020): 2473011420S0030. http://dx.doi.org/10.1177/2473011420s00305.
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Category: Bunion; Midfoot/Forefoot Introduction/Purpose: The proximal opening wedge metatarsal osteotomy (PMO) of the first metatarsal is a common procedure for the surgical treatment of moderate to severe hallux valgus. Although with a long track record of success, limited work has been dedicated to this procedures effect on the first tarsometatarsal (TMT-1) joint. The purpose of this study is to evaluate the changes in TMT-1 joint contact stress in the diseased and corrected state following an opening wedge osteotomy of the proximal metatarsal. In addition, the effect of a distal soft tissue release (DSTR) was evaluated as it related to both radiographic correction and TMT-1 joint contact stress. Methods: Seven fresh-frozen cadaveric below knee specimens (mean age: 69yrs) with hallux valgus deformities (mean HVA: 31.7+-12.0degs) were obtained for the study. The specimen was loaded up to 400N on an MTS servo hydraulic load frame with the tibia at 90-degree to the neutrally position foot. Joint contact characteristics at TMT-1 joint were measured with a Tekscan pressure sensor (Model6900, 1100psi). A standard proximal metatarsal osteotomy was performed. Various sized metal wedges (3, 5, 7 mm) with locking plates and screws were inserted in the osteotomy for correction. Following initial tests, a complete distal soft tissue release (DSTR) was performed and the specimens were retested. Additionally, dorsoplantar weight bearing (400N) radiograph was obtained for each condition to measure intermetatarsal (IMA) and hallux valgus (HVA) angles. The contact force, area, and peak contact stress were compared among groups using ANOVA and post-hoc multiple comparisons over the untreated (Dunnett test, p<0.05). Results: The mean HVA decreased with wedge size and DSTR, reached to significant level with 7mm+DSTR (24.1 degs). The mean contact force was 39.7+-32.6 N for untreated specimens. This increased sequentially with opening wedge size and reached statistical significance 7mm opening-wedge (119.6+-53.8 N, p=0.03) and 7mm-wedge+DSTR (116.7+-58.3 N, p=0.04). The peak contact stress followed a similar trend (Figure 1). The mean peak contact stress was 2.3+-1.5 MPa for the untreated specimens and increased incrementally with wedge size to 5.3+-2.6 MPa for 7mm-wedge only (p=0.03) and 5.2+-2.1 MPa for 7mm- wedge+DSTR (p=0.04). Contact area increased with corrections, but none reached significance. Conclusion: The results from this study demonstrate that with sequentially increasing opening wedge size, loading properties through the TMT-1 joint increase. Prior work has demonstrated that joint stresses of over 4.7 MPa can be chondrotoxic, a value which was surpassed with our peak contact stress with the 7mm wedge. This has significant implications for the long-term health of the TMT-1 joint following PMO, potentially predisposing patients to arthritic joint changes. The optimal degree of correction with PMO to limit chondrotoxicity is not known at this time, and is a direction for future work.
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Alwadani, Fawaz A., Huaqing Liang, and Alexander S. Aruin. "Effects of Ankle Angular Position and Standing Surface on Postural Control of Upright Stance." Motor Control 24, no. 2 (April 1, 2020): 291–303. http://dx.doi.org/10.1123/mc.2019-0079.
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The purpose of the study was to investigate the effects of ankle angular position and standing surface type on static upright balance. Ten young adults stood on a force platform or on a firm wedge that induced 15° of either dorsiflexion or plantarflexion. In addition, a piece of foam was placed on top of the force platform and on the wedge. The center of pressure distance and velocity in the anteroposterior and mediolateral directions were calculated. Significantly larger magnitudes in most of the investigated variables were seen while standing with ankles in the dorsiflexion when compared with standing with the ankle joints in a natural position (p < .05). Plantarflexion increased the center of pressure anteroposterior velocity by 87% when compared with a natural stance (p < .05). Standing on the foam surfaces resulted in increases in all of the center of pressure measures by an average of 38% in all of the ankle conditions.
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Filippov, A. V. "Constructing a Model of the Equivalent Wedge Oblique Cutting Edge." Applied Mechanics and Materials 379 (August 2013): 139–44. http://dx.doi.org/10.4028/www.scientific.net/amm.379.139.
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The article presents a method for constructing a three-dimensional model of the equivalent wedge oblique cutting edge. This technique allows you to visually assess the complexity of changing the geometry of the tool and can be used in the design of cutting edge with a curved wedge. To construct a model, the equation of a space curve of cutting edge working part was derived. The article also shows the position of the tool-in-hand and the setting system in the developed model.
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Park, Hyun-Young, Soo-Joon Chae, and Moon-Kyung Cho. "Controlling shareholders’ ownership structure, foreign investors’ monitoring, and investment efficiency." Investment Management and Financial Innovations 13, no. 3 (September 23, 2016): 159–70. http://dx.doi.org/10.21511/imfi.13(3-1).2016.02.
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This study examines the effect of control-ownership wedge (the difference between control rights and cash flow rights) on investment efficiency. Subsequently, the authors analyze how the level of foreign investor monitoring influences the association between control-ownership wedge and investment efficiency. The results of the analyses show that investment efficiency deteriorates as control-ownership wedge increases. This, in turn, suggests that when this wedge increases, agency problems and information asymmetry between controlling and minority shareholders become more severe. The authors also perform an analysis by dividing the samples into four groups based on foreign investor ratio from the least to the greatest. The result shows that control-ownership wedge deteriorates investment efficiency in the group with the least foreign investor ratio. The result reveals that foreign investor monitoring is effective corporate governance mechanism to monitor the controlling shareholders’ investment decisions. We also find that higher control-ownership wedge with over-investment tendency negatively affects firm performance, which implies an inefficient investment behavior. This result suggests that as controlling shareholders’ ownership increases, controlling shareholders becomes more and more reluctant to assume a loss of firm value as a result of reduced investment efficiency. This study provides additional evidence that the greater control-ownership wedge decreases investment efficiency, while recent studies on the relation between control-ownership wedge and investment efficiency suggest mixed evidence. In addition, the results show that foreign investors play an effective monitoring role when controlling shareholders are in position of exercising exclusive power. The results indicate the importance of external investors’ monitoring over investment decisions. Keywords: control-ownership wedge, foreign ownership, investment efficiency, over-investment, under-investment. JEL Classification: G32, M41
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Almajidy, Arwa, and Sabah Naji. "http://www.iqnjm.com/wp-content/uploads/2020/01/Unmet-health-care-work-s-2-No..pdf." Iraqi National Journal of Medicine 2, no. 1 (January 15, 2020): 42–51. http://dx.doi.org/10.37319/iqnjm.2.1.4.
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Background: Clinodactyly or inclination of the digits, particularly the fifth digit, is a congenital anomaly of the hand that occurs in 1% to 19.5% of the population. This deformity requires reconstruction of both the functional and the aesthetic appearance of the finger, if it is severe, to avoid future growth deformity. Objective: The study aims to review the outcomes and the complications associated with closing and reverse wedge osteotomy techniques for treating clinodactyly. Patients and Methods: Ten patients’ ten fingers with clinodactyly were submitted for reconstruction from March 2014 to May 2016 in the Al Wasity teaching hospital in Baghdad. They were treated using the closing and reverse wedge osteotomy techniques. In the closing wedge procedure, a wedge was removed from the most convex part of the middle phalanx. Subsequently, the finger is aligned in the midaxial plane and repaired with 2 K-wires. In the reverse wedge osteotomy, the wedge was rotated 180 degrees and reinserted into the bone gap with the wide end first. This buttressed the osteotomy open. Subsequently, the K-wires were inserted in retrograde fashion, maintaining the graft’s position. Then, dressing was applied with the small splint from the PIP to the tip of the finger. Results: After a 15-month follow-up, all the patients showed satisfactory results aesthetically and the functionally—with full range of motion. There was no recurrence in any case. Only one case had residual angulation and no major complications were encountered. Conclusion: The closing and reverse wedge osteotomy was proven effective in treating clinodactyly. The closing wedge is simpler than the reverse wedge. The technical difficulty of reverse wedge osteotomy may make it a less appealing option to surgeons but the outcomes we had were rewarding, both techniques provided good overall correction of angulation in one stage, and straightforward procedure, with few complications, good aesthetic outcome and patient satisfaction with improved function. Keywords: clinodactyly, closing wedge, reverse wedge
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CITTEUR, J. M. E., M. J. P. F. RITT, and K. E. BOS. "Carpal Boss: Destabilization of the third Carpometacarpal Joint after a Wedge Excision." Journal of Hand Surgery 23, no. 1 (February 1998): 76–78. http://dx.doi.org/10.1016/s0266-7681(98)80225-8.
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In a standard carpal boss procedure, the dorsal ligament of the involved carpometacarpal joint is cut in the process of performing a wedge excision. We studied the effect of such a dorsal ligament sectioning on the joint between the capitate and middle metacarpal bone in ten fresh-frozen wrist specimens. The passive range of motion of this joint was measured with the joint loaded into flexion and extension and in the unloaded neutral position. After the dorsal ligament of the carpometacarpal joint was cut, simulating a dorsal wedge excision, the passive range of motion was measured again. Analysis indicated that this simulated wedge excision approximately doubled the passive range of motion of the carpometacarpal joint. This study shows that such a procedure disturbs the normal anatomy and creates instability of the involved joint.
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Wu, Yiting, Elisa Wirthmann, Ute Klöpzig, and Tino Hausotte. "Development of a Metrological Atomic Force Microscope System with Improved Signal Quality." Engineering Proceedings 6, no. 1 (May 17, 2021): 49. http://dx.doi.org/10.3390/i3s2021dresden-10102.
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This article presents a new metrological atomic force microscope (MAFM) with a homodyne interferometer and a tilt measuring system by a position sensitive device (PSD). The combination allows simultaneous three-dimensional detection of the tip displacement by capturing the position, bending and torsion of a reflecting surface of the cantilever realized with one laser beam. Based on an existing interferometric measuring head of a micro-tactile 3D probe, the sensor head was revised and adapted for atomic force microscopy. The new measuring system uses two tiltable plane mirrors to adjust the direction and position of a focused laser beam. With this adjustment unit, the focused laser beam can be steered perpendicular to the reflecting backside of the cantilever. Regarding the probe system, the optical design of the measuring head has been reengineered to reduce the disturbing interference on the PSD. A simulation applying the optical design program OpticStudio from Zemax shows that the integration of two wedge plates with a wedge angle of 0.5° reduces the disturbing interference significantly. After manufacturing, initial measurement results are presented to verify the functionality.
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Lv, Xin, and Guan-Ting Liu. "Exact Solutions for Interaction of Parallel Screw Dislocations with a Wedge Crack in One-Dimensional Hexagonal Quasicrystal with Piezoelectric Effects." Mathematical Problems in Engineering 2020 (May 29, 2020): 1–15. http://dx.doi.org/10.1155/2020/4797413.
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The purpose of this paper is to consider the interaction between many parallel dislocations and a wedge-shaped crack and their collective response to the external applied generalized stress in one-dimensional hexagonal piezoelectric quasicrystal, employing the complex variable function theory and the conformal transformation method; the problem for the crack is reduced to the solution of singular integral equations, which can be further reduced to solving Riemann–Hilbert boundary value problems. The analytical solutions of the generalized stress field are obtained. The dislocations are subjected to the phonon field line force, phason field line force, and line charge at the core. The positions of the dislocations are arbitrary, but the dislocation distribution is additive. The dislocation is not only subjected to the external stress and the internal stress generated by the crack, but also to the force exerted on it by other dislocations. The closed-form solutions are obtained for field intensity factors and the image force on a screw dislocation in the presence of a wedge-shaped crack and a collection of other dislocations. Numerical examples are provided to show the effects of wedge angle, dislocation position, dislocation distribution containing symmetric configurations and dislocation quantities on the field intensity factors, energy release rate, and image force acting on the dislocation. The principal new physical results obtained here are (1) the phonon stress, phason stress, and electric displacement singularity occur at the crack tip and dislocations cores, (2) the increasing number of dislocations always accelerates the crack propagation, (3) the effect of wedge angle on crack propagation is related to the distribution of dislocations, and (4) the results of the image force on the dislocation indicate that the dislocations can either be attracted or rejected and reach stable positions eventually.
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Yalfani, Ali, Azadeh Asgarpour, and Zahra Raeisi. "Comparing the effective interventions on plantar and ankle proprioception in balance control with and without fatigue." Journal of Shahrekord University of Medical Sciences 21, no. 1 (April 6, 2018): 45–50. http://dx.doi.org/10.34172/jsums.2019.08.
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Background and aims: The "postural control" is one of the important abilities to maintain body balance especially during upright stances which is a basic requirement in human life. The role of proprioception in the ankle joint function is essential to maintain balance and function correctly during gate and upright stances. Fatigue is one of the essential factors disrupting the proprioception. The purpose of the present study was to compare effective interventions on plantar and ankle proprioception in balance control with and without fatigue. Methods: Twenty female college students participated in this study. The participants taped the ankle or wore three types of insoles (i.e., normal, 10-degree lateral, and medial wedge) before and after using a fatigue protocol with and without visual information. Their static and dynamic balance was evaluated by the Biodex Balance System (BBS). Data analysis was performed employing the SPSS software. Besides, the significance level was considered at 0.05. Results: The results indicated that application of wedge insoles was associated with a significant reduction of postural sway during static balance position. In addition, the 10-degree lateral wedge insole had a greater effect for improving the balance of non-visual position after using the fatigue protocol. However, there were no significant differences between taping and insole types regarding improving the dynamic balance. Conclusion: Generally, it was inferred that wedge insoles could be used to improve the static balance with and without fatigue. However, Kinesio tape had no effect on static balance. Moreover, results regarding the effectiveness of the studied interventions in relation to the dynamic balance improvement were not significant.
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Sonohata, Motoki, Masaru Kitajima, Shunsuke Kawano, and Masaaki Mawatari. "Comparison of Total Hip Arthroplasty Outcomes after Failed Femoral Wedge or Curved Varus Osteotomy." Open Orthopaedics Journal 12, no. 1 (June 25, 2018): 208–17. http://dx.doi.org/10.2174/1874325001812010208.
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Background: Differences in clinical and radiographic results following total hip arthroplasty between failed wedge and curved varus osteotomy are unclear. Objective: To investigate differences in clinical and radiographic results following total hip arthroplasty in patients who exhibited failed wedge or curved varus osteotomy. Method: We performed 18 total hip arthroplasties after failed femoral varus osteotomy. Hips were divided into two groups: 14 had failed wedge varus osteotomy and four had failed curved varus osteotomy. Average ages at osteotomy and total hip arthroplasty were 27 years old (range, 10-46 years old) and 56 years old (range, 25-74 years old), respectively. The average duration of follow-up monitoring was 72.2 months (range, 54-91 months). Clinical and radiographic evaluations were completed for each group. Results: The Japanese Orthopaedic Association hip score of total hip arthroplasty after failed varus osteotomy significantly improved at the last follow-up in both groups. However, hip score at the last follow-up was significantly higher after failed curved varus osteotomy than after failed wedge varus osteotomy (p<0.01). Four hips that failed wedge varus osteotomy underwent subtrochanteric corrective osteotomy with total hip arthroplasty. Radiographic evaluation showed that three stems for total hip arthroplasty after failed wedge varus osteotomy were inserted in malposition, and all stems in total hip arthroplasty after failed curved varus osteotomy were inserted in the normal position. Conclusion: Surgeons performing femoral varus osteotomy should consider possible future conversion to total hip arthroplasty. Curved varus osteotomy is more suitable than wedge varus osteotomy for future conversion to total hip arthroplasty.
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Jang, Hyungkwan, Hyunwoo Kim, Huai-Cong Liu, Ho-Joon Lee, and Ju Lee. "Investigation on the Torque Ripple Reduction Method of a Hybrid Electric Vehicle Motor." Energies 14, no. 5 (March 4, 2021): 1413. http://dx.doi.org/10.3390/en14051413.
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Owing to the development of electric vehicles (EVs), research and development are underway to minimize torque ripple in relation to vibration and noise in EV motors. Although there are various ways to reduce torque ripple, this study analyzes the torque ripple, cogging torque, total harmonic distortion (THD), and magnetic flux density distribution for the three rotor shapes of interior permanent magnet synchronous motors, which are widely employed in EVs. To reduce the torque ripple while retaining the required average torque, the barrier shape is optimized, and wedge skew is applied. First, regarding the rotor barrier shape, torque ripple is primarily reduced by designing the rotor barrier shape with the response surface method, which is an experimental design method. Additionally, the wedge skew shape considering the bidirectional rotation and fabrication was applied to the stator shoe as a step and analyzed using three-dimensional finite element analysis. When designing the wedge skew, the layer subdivision according to the axial length, wedge skew diameter, and wedge skew position was analyzed and improved. The torque ripple reduction method in this paper can be applied not only to motors for EVs or Hybrid EVs (HEVs) but also all types of permanent magnet synchronous motors.
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Liu, Li, Zhen Yang, Pan Zhou, and Hongwei Yang. "An Analytical Method of Coulomb’s Active Earth Pressure Acting on Cohesion-Less Backfill Subject to Local Surcharge in Cold Regions." Advances in Civil Engineering 2020 (August 29, 2020): 1–13. http://dx.doi.org/10.1155/2020/8827006.
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The traditional Coulomb’s earth pressure theory does not consider the effect of local surcharge on the lateral earth pressure and its critical failure angle. However, in practice, local surcharges commonly act on the surface of frozen backfill that is affected by freeze-thaw actions in cold regions and tend to affect the active thrust and its position. In paper, analytical solutions for estimating the active thrust, critical wedge failure angle, and action position subject to a local surcharge in cold regions are proposed. Herein, the simplified equivalent moment of surcharge is adopted on the premise of maintaining Coulomb’s earth pressure assumptions. The formula derivation is provided as a typical example to obtain the active thrust, critical wedge failure angle, and its position under a strip surcharge. Compared with previous approaches, the proposed solutions lead to easier evaluation of all indexes associated with Coulomb’s active earth pressure. Meanwhile, the expressions of Coulomb’s earth pressure under other types of nonuniform loading acting on the wall are discussed. In addition, sensitivity is performed to assess the effect of some main parameters. The results indicate that the dip angle of retaining wall-back and the friction angle of frozen backfill soil are two most significant indexes that influence the active thrust and its position.
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Bruce, L. C., P. L. M. Cook, I. Teakle, and M. R. Hipsey. "Controls on oxygen dynamics in a riverine salt-wedge estuary – a three-dimensional model of the Yarra River estuary, Australia." Hydrology and Earth System Sciences Discussions 10, no. 7 (July 26, 2013): 9799–845. http://dx.doi.org/10.5194/hessd-10-9799-2013.
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Abstract. Oxygen depletion in estuarine waters is an important factor governing water quality and ecological health. A complex and dynamic balance of physical and biogeochemical factors drive the extent and persistence of hypoxia and anoxia making it difficult to predict. An increased understanding of the effect of changing flow regimes and temperature on patterns of estuarine oxygen depletion is required to support ongoing management. Coupled physical and biogeochemical models have been applied to study the interaction of physical processes and seasonal hypoxia, however, application to riverine estuaries with tight curvature and more sporadic periods of oxygen depletion is rare. In this study we apply a finite volume 3-D hydrodynamic-biogeochemical model (TUFLOW-FV–FABM) to the Yarra River estuary, Australia, in order to predict the extent of salt-wedge intrusion and consequent patterns of oxygen depletion. The predictive capacity of the model was evaluated using a series of model verification metrics and the results evaluated to determine the dominant mechanisms affecting salt-wedge position and the extent and persistence of anoxia and hypoxia. Measures of model fit indicated that the model reasonably captured the strength of stratification and the position and extent of the salt wedge (r2 ~ 0.74). The extent of the salt wedge intrusion was controlled by riverine flow and the strength of stratification or mixing dominated by topographical features corresponding to areas of tight curvature ("horseshoe" bends). The model predicted that the extent of anoxic waters generally mimicked the extent of the salt wedge (r2 ~ 0.65) increasing during periods of low flow and reduced following episodic high flow events. The results showed two sporadically isolated "hot spots" of anoxia, the first downstream of the horseshoe bend and the second downstream of a sill. Simulated oxygen concentrations indicated that whilst a threshold salt wedge intrusion was a requirement of oxygen depletion, temperature was critical in determining the extent of hypoxia and anoxia in the estuary. These findings highlight the importance of how seasonal changes in flow events and environmental flow management can impact on estuarine oxygen depletion in a warming climate. This study provides an improved understanding of the controls on hypoxia and anoxia in riverine estuaries, which is essential to support improved prediction of nutrient dynamics and ecological heath.
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Ca´rdenas-Garci´a, J. F., K. P. Suryanarayan, and W. E. Ingalls. "Mechanical Alignment Using Duplicate Circular Wedges." Journal of Mechanical Design 121, no. 2 (June 1, 1999): 305–9. http://dx.doi.org/10.1115/1.2829458.
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There is a need for the repeatable, accurate, precise and versatile alignment of mechanical components. A flexible and inexpensive approach to this problem is the use of a duplicate pair of wedged discs. This paper uses kinematic transformation matrices to examine in detail the design of such a wedge pair. The accuracy, precision and versatility of the circular wedges are shown to be functions of wedge angle, the number of positions or increments along the circumference of the circular wedge, and changes in the offset angle, which defines the asymmetry of the discs.
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Coates, Michael J., and Yakun Guo. "The salt wedge position in a bar-blocked estuary subject to pulsed inflows." Estuarine, Coastal and Shelf Science 58, no. 1 (September 2003): 187–96. http://dx.doi.org/10.1016/s0272-7714(03)00076-3.
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Eliasberg, Claire D., Kyle N. Kunze, Erica Swartwout, Atul F. Kamath, Hugo Robichaud, and Anil S. Ranawat. "Extreme Hinge Axis Positions Are Necessary to Achieve Posterior Tibial Slope Reduction With Small Coronal-Plane Corrections in Medial Opening Wedge High Tibial Osteotomy." Orthopaedic Journal of Sports Medicine 10, no. 5 (May 1, 2022): 232596712210943. http://dx.doi.org/10.1177/23259671221094346.
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Background: Both coronal- and sagittal-plane knee malalignment can increase the risk of ligamentous injuries and the progression of degenerative joint disease. High tibial osteotomy can achieve multiplanar correction, but determining the precise hinge axis position for osteotomy is technically challenging. Purpose: To create computed tomography (CT)–based patient-specific models to identify the ideal hinge axis position angle and the amount of maximum opening in medial opening wedge high tibial osteotomy (MOWHTO) required to achieve the desired multiplanar correction. Study Design: Descriptive laboratory study. Methods: A total of 10 patients with lower extremity CT scans were included. Baseline measurements including the mechanical tibiofemoral angle (mTFA) and the posterior tibial slope (PTS) were calculated. Virtual osteotomy was performed to achieve (1) a specified degree of PTS correction and (2) a planned degree of mTFA correction. The mean hinge axis position angle for MOWHTO to maintain an anatomic PTS (no slope correction) was 102.6° ± 8.3° relative to the posterior condylar axis (PCA). Using this as the baseline correction, the resultant hinge axis position and maximum opening were then calculated for each subsequent osteotomy procedure. Results: For 5.0° of mTFA correction, the hinge axis position was decreased by 6.8°, and the maximum opening was increased by 0.49 mm for every 1° of PTS correction. For 10.0° of mTFA correction, the hinge axis position was decreased by 5.2°, and the maximum opening was increased by 0.37 mm for every 1° of PTS correction. There was a significant difference in the trend-line slopes for hinge axis position versus PTS correction ( P = .013) and a significant difference in the trend-line intercepts for maximum opening versus PTS correction ( P < .0001). Conclusion: The mean hinge axis position for slope-neutral osteotomy was 102.6° ± 8.3° relative to the PCA. For smaller corrections in the coronal plane, more extreme hinge axis positions were necessary to achieve higher magnitudes of PTS reduction. Clinical Relevance: Extreme hinge axis positions are technically challenging and can lead to unstable osteotomy. Patient-specific instrumentation may allow for precise correction to be more readily achieved.
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Ewert, Ralf, Alexander Heine, Annegret Müller-Heinrich, Tom Bollmann, Anne Obst, Susanna Desole, Christine Knaak, Beate Stubbe, Christian F. Opitz, and Dirk Habedank. "Exercise and fluid challenge during right heart catheterisation for evaluation of dyspnoea." Pulmonary Circulation 10, no. 3 (June 11, 2020): 10.1177_2045894. http://dx.doi.org/10.1177/2045894020917887.
Full textAbstract:
This prospective study compared exercise test and intravenous fluid challenge in a single right heart catheter procedure to detect latent diastolic heart failure in patients with echocardiographic heart failure with preserved ejection function. We included 49 patients (73% female) with heart failure with preserved ejection function and pulmonary artery wedge pressure ≤15 mmHg. A subgroup of 26 patients had precapillary pulmonary hypertension. Invasive haemodynamic and gas exchange parameters were measured at rest, 45° upright position, during exercise, after complete haemodynamic and respiratory recovery in lying position, and after rapid infusion of 500 mL isotonic solution. Most haemodynamic parameters increased at both exercise and intravenous fluid challenge, with the higher increase at exercise. Pulmonary vascular resistance decreased by –0.21 wood units at exercise and –0.56 wood units at intravenous fluid challenge ( p = 0.3); 20% (10 of 49) of patients had an increase in pulmonary artery wedge pressure above the upper limit of 20 mmHg at exercise, and 20% above the respective limit of 18 mmHg after intravenous fluid challenge. However, only three patients exceeded the upper limit of pulmonary artery wedge pressure in both tests, i.e. seven patients only at exercise and seven other patients only after intravenous fluid challenge. In the subgroup of pulmonary hypertension patients, only two patients exceeded pulmonary artery wedge pressure limits in both tests, further five patients at exercise and four patients after intravenous fluid challenge. A sequential protocol in the same patient showed a significantly higher increase in haemodynamic parameters at exercise compared to intravenous fluid challenge. Both methods can unmask diastolic dysfunction at right heart catheter procedure, but in different patient groups.
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Theodoulidis, T. P., and J. R. Bowler. "Eddy current coil interaction with a right-angled conductive wedge." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 461, no. 2062 (August 17, 2005): 3123–39. http://dx.doi.org/10.1098/rspa.2005.1509.
Full textAbstract:
The time-harmonic electromagnetic field in an electrically conductive right-angled wedge due to an inductive excitation by circular coil in air has been calculated. Using a formulation in Cartesian coordinates, the problem domain is truncated in a dimension whose axis is normal to a wedge face, and an approximate series solution found using elementary functions satisfying Maxwell's equations in the quasi-static limit. The coil impedance variation with position and frequency is calculated and compared with measurements made on a coil near the edge of a large aluminium block which approximates the effect of a conductive quarter-space. The comparison between theory and experiment shows very close agreement.
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GHADIMI, PARVIZ, AMIR SAADATKHAH, and ABBAS DASHTIMANESH. "ANALYTICAL SOLUTION OF WEDGE WATER ENTRY BY USING SCHWARTZ–CHRISTOFFEL CONFORMAL MAPPING." International Journal of Modeling, Simulation, and Scientific Computing 02, no. 03 (September 2011): 337–54. http://dx.doi.org/10.1142/s1793962311000487.
Full textAbstract:
Water impact is one of the most critical phenomena from the viewpoint of the structural design of ships and offshore structures. The impact force can impose a large load with high local pressure on the body surface. On the other hand, determination of the maximum impact force during impact and acting point itself is very important in the design of floats. In this paper, the water entry of a two-dimensional wedge section is considered. This study is carried out in the framework of a potential-flow assumption. In particular, water impact on a dropping wedge with a constant velocity is pursued analytically by using the Schwartz–Christoffel conformal mapping. In order to determine a position of the wedge where the instantaneous effective force is largest during the impact, a particular equation is introduced here for the first time. The pressure distribution and maximum impact force are also calculated. The obtained results are compared against other numerical and experimental works and favorable agreement is displayed.