Academic literature on the topic 'SWING STABILITY'
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Journal articles on the topic "SWING STABILITY"
1
Gonzalez-Longatt, Francisco, Choidorj Adiyabazar, and Ernesto Vazquez Martinez. "Setting and Testing of the Out-of-Step Protection at Mongolian Transmission System." Energies 14, no. 23 (2021): 8170. http://dx.doi.org/10.3390/en14238170.
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Modern distance relays have integrated numerous protection functions, including power-swing blocking and out-of-step or pole-slip tripping functions. The main purpose of the power-swing blocking function is to differentiate faults from power swings and block distance or other relay elements from operating during stable or unstable power swings. Most power-swing blocking elements are based on traditional methods that monitor the positive sequence impedance rate. The required settings for the power-swing blocking elements could be difficult to calculate in many applications, particularly those where fast swings can be expected. For these cases, extensive stability studies are necessary to determine the fastest rate of possible power swings. This paper presents a detailed step-by-step method for settings calculation of out-of-step (OOS) protection, both blocking and tripping functions considering a generic two-source system. Then the method is applied to define the protection relay settings installed at the interconnection between the Russian and Mongolian power systems, as it is crucial to feed the demand-rich Mongolian power system. In this paper, a specific impedance method is used for defining the OOS protection settings. This paper innovates by testing the settings using the recordings of the major events of 15 September 2018 in two approaches: hybrid co-simulation and cyber-physical. Both tests have demonstrated the appropriate performance of the proposed settings and proving the proposed methodology works appropriately.
2
Qin, Jian-Hua, Jie Luo, Kai-Chi Chuang, Tian-Syung Lan, Lie-Ping Zhang, and Huai-An Yi. "Stable Balance Adjustment Structure of the Quadruped Robot Based on the Bionic Lateral Swing Posture." Mathematical Problems in Engineering 2020 (August 28, 2020): 1–10. http://dx.doi.org/10.1155/2020/1571439.
Full textAbstract:
Aiming at the problem that the stability of the quadruped robot is decreased as its leg momentum is too high, a stable balance adjustment structure of the quadruped robot based on the bionic lateral swing posture is proposed. First, the leg structure of the quadruped robot is improved and designed by using the mechanism of the lateral swing posture of the leg of the hoof animal. Then, the D-H method is used to construct the corresponding leg kinematics model and determine the generalized coordinates of the leg joints in the lateral swing posture. The torque expression of the quadruped robot when it is tilted is established. Based on the differential equation of momentum of the hip joint and its static stability analysis, the static stability conditions in the upright posture and the bionic lateral swing posture are given. Finally, the experimental simulation and comparative analysis of the upright posture and the lateral swing posture of the quadruped robot are proposed by using the Adams virtual prototype technology. The simulation results show that as the angle of lateral swing increases, the peak value of the positive flip torque of the quadruped robot body increases accordingly, while the degree of tilt decreases accordingly, which shows that the bionic lateral swing posture of the quadruped robot has higher static stability than the traditional upright posture. This research provides a technical reference for the design and optimization of the offline continuous gait of the robot and the improvement of stability.
3
Rahmeyer, W. J. "Sizing Swing Check Valves for Stability and Minimum Velocity Limits." Journal of Pressure Vessel Technology 115, no. 4 (1993): 406–10. http://dx.doi.org/10.1115/1.2929548.
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Unexpected wear and failure of swing check valves cost power plants and water treatment facilities millions of dollars each year. Operating swing check valves at too low flow velocities can cause the check valve internals to rapidly wear and suddenly fail. Many of the swing check valve failures could have been avoided by the use of a minimum velocity limit or a numerical model to predict the limit of minimum velocity. The following equations and methodology can be used to predict a minimum velocity limit or VMIN for swing check valves. The limit of VMIN is defined as the minimum flow velocity in which the valve disk is fully open and stable without motion. The procedures and equations can also be used to predict the velocity (VOPEN) to just open the disk to any position or angle. The equations presented in this paper are also unique in that they can be applied to swing check valves that have large degrees of disk position or valve opening. The equations are not limited to swing check valves that must have a portion of the valve disk protruding into the flow through the check valve. Although the methodology was developed primarily for horizontal liquid flows, limited testing has shown that the equations can be applied for installations with inclined slopes and for applications with compressible fluids. The following equations were derived from a large data base of tests of different sizes and types of swing check valves. Tables and figures are presented to support the suggested equations.
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Ferraris, Claudia, Gianluca Amprimo, Giulia Masi, et al. "Evaluation of Arm Swing Features and Asymmetry during Gait in Parkinson’s Disease Using the Azure Kinect Sensor." Sensors 22, no. 16 (2022): 6282. http://dx.doi.org/10.3390/s22166282.
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Arm swinging is a typical feature of human walking: Continuous and rhythmic movement of the upper limbs is important to ensure postural stability and walking efficiency. However, several factors can interfere with arm swings, making walking more risky and unstable: These include aging, neurological diseases, hemiplegia, and other comorbidities that affect motor control and coordination. Objective assessment of arm swings during walking could play a role in preventing adverse consequences, allowing appropriate treatments and rehabilitation protocols to be activated for recovery and improvement. This paper presents a system for gait analysis based on Microsoft Azure Kinect DK sensor and its body-tracking algorithm: It allows noninvasive full-body tracking, thus enabling simultaneous analysis of different aspects of walking, including arm swing characteristics. Sixteen subjects with Parkinson’s disease and 13 healthy controls were recruited with the aim of evaluating differences in arm swing features and correlating them with traditional gait parameters. Preliminary results show significant differences between the two groups and a strong correlation between the parameters. The study thus highlights the ability of the proposed system to quantify arm swing features, thus offering a simple tool to provide a more comprehensive gait assessment.
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Remelius, Jebb G., and Richard E. A. van Emmerik. "Time-To-Contact Analysis of Gait Stability in the Swing Phase of Walking in People With Multiple Sclerosis." Motor Control 19, no. 4 (2015): 289–311. http://dx.doi.org/10.1123/mc.2013-0106.
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This study investigated timing and coordination during the swing phase of swing leg, body center of mass (CoM) and head during walking people with multiple sclerosis (MS; n = 19) and controls (n = 19). The MS group showed differences in swing phase timing at all speeds. At imposed but not preferred speeds, the MS group had less time to prepare for entry into the unstable equilibrium, as the CoM entered this phase of swing earlier. Time-to-contact coupling, quantifying the coordination between the CoM and the swing foot, was not different between groups. The projection of head motion on the ground occurred earlier after toeoff and was positioned closer to the body in the MS group, illustrating increased reliance on visual exproprioception in which vision of the body in relation to the surface of support is established. Finally, prospective control, linking head movements to the swing foot time-to-contact and next step landing area, was impaired in the MS group at higher gait speeds.
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Lee, Ho-Hoon. "A New Motion-Planning Scheme for Overhead Cranes With High-Speed Hoisting." Journal of Dynamic Systems, Measurement, and Control 126, no. 2 (2004): 359–64. http://dx.doi.org/10.1115/1.1767855.
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This paper proposes a motion-planning method for a high-performance anti-swing control of overhead cranes, where the motion-planning problem is solved as a kinematic problem. First, an anti-swing regulating control law is proposed based on the Lyapunov stability theorem, where the proposed anti-swing control drives trolley velocity regulating error asymptotically to zero while suppressing load swing rapidly to zero for given arbitrary high-speed hoisting motions. Then a motion-planning scheme is designed based on the concept of minimumtime control, the proposed anti-swing control law, and typical anti-swing crane-operation practices. The motion-planning scheme is free from the usual mathematical constraints in anti-swing control such as small swing angle, small hoisting speed, and small hoisting distance. The effectiveness of the proposed motion planning is shown by generating high-performance anti-swing trajectories with high hoisting speed and hoisting ratio.
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Li, Ang, Jin Yun Pu, and Yue Hou. "On the Dynamic Characteristics of Swinging Damaged Rectangular Vessels - An Analysis Employing Collaborative Simulation Based on MATLAB/FLUENT." Applied Mechanics and Materials 253-255 (December 2012): 2145–51. http://dx.doi.org/10.4028/www.scientific.net/amm.253-255.2145.
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The existing stability evaluation methods of damaged vessels fell short of the consideration of the turbulent characteristics. Based on the analysis of the coupled relation of the damaged rectangular vessels’ stability and the water dynamic characteristics under different stages, collaborative simulations were made with the aid of MATLAB and FLUENT. Results show that: (1) the swing significantly hinders the turbulent; when the swinging amplitude is comparatively small, its impact is weakened accordingly. (2) When the swinging amplitude increases, in phase , backflow emerges. (3) When the swing frequency is high, an extremum appeared in phase , whose value is determined by the biggest swing angular acceleration.
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Al-Badrany, Ahmad A. "Modeling and Simulation of Out of Step Blocking Relay for Power Swing using Concentric Polygons Scheme." Tikrit Journal of Engineering Sciences 17, no. 1 (2010): 21–31. http://dx.doi.org/10.25130/tjes.17.1.08.
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This paper investigates a power swing effect on a distance protection relay performance installed on (HV/EHV) transmission line as well as power system stability. A conventional distance relay can’t properly operate under transient stability conditions; therefore, it cause mol-operation, and it will adversely impact on its trip signals. To overcome this problem, the Out Of Step (OOS) relay has modeled and simulated to joint with distance relay to supervise and control on its trip signals response. The setting characteristics technique of the OOS based on concentric polygons scheme method to detect power swing under transient stability situation. This study ia a modeling and simulating using (Maltab\ Simulink) software. A Two relays had been performed and tested with two equivalents network connected to ends. The results of this study showed an activity and reliability of this way to control the distance relay response under a transient stability conditions and it indicated the possibility to find out faults which may occur at period of power swing.
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Liu, Peng Fei, Bin Lin, Xiao Feng Zhang, Xu Zhang, and Meng Long Zhou. "Safety and Stability Analysis of the Ship Loader during Shipping." Materials Science Forum 770 (October 2013): 189–93. http://dx.doi.org/10.4028/www.scientific.net/msf.770.189.
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The influence which is brought by the variation law of the whole machines center of gravity position when the telescopic boom and fixed boom at different pitch angles during shipping is been given by using ANSYS and MATLAB. Meanwhile, the influence which the swing arms different pitch angles bring to the safety of the ship loaders own structure is also being analyzed in this paper. Finally, the best placement angle of the ship loaders swing arm is given based on the comprehensive analysis of all factors.
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Siragy, Tarique, Allen Hill, and Julie Nantel. "Recovery of dynamic stability during slips unaffected by arm swing in people with Parkinson’s Disease." PLOS ONE 16, no. 4 (2021): e0249303. http://dx.doi.org/10.1371/journal.pone.0249303.
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The arm elevation strategy assists in recovering stability during slips in healthy young and elderly individuals. However, in people with Parkinson’s Disease, one of the main motor symptoms affecting the upper limbs is reduced arm swing which intensifies throughout the course of the disease before becoming absent. This holds direct implications for these individuals when encountering slips as the arm elevation strategy is an integral component in the interlimb slip response to restore stability. Arm swing’s effect in recovering from slips in people with Parkinson’s Disease though remains unexamined. Twenty people with Parkinson’s Disease (63.78 ± 8.97 years) walked with restricted and unrestricted arm swing conditions on a dual-belt treadmill where slips were induced on the least and most affected sides. Data were collected on the CAREN Extended System (Motek Medical, Amsterdam, NL). The Margin of Stability, linear and angular trunk velocities, as well as step length, time, and width were calculated. Data were examined during the slipped step and recovery step. The restricted arm swing condition, compared to unrestricted, caused a faster step time during the slipped step. Compared to the most affected leg, the least affected had a wider step width during the slipped step. During the recovery step, the least affected leg had a larger anteroposterior Margin of Stability and longer step time than the most affected. No differences between our arm swing conditions suggests that the normal arm swing in our participants was not more effective at restoring stability after an induced slip compared to when their arm motion was restricted. This may be due to the arm elevation strategy being ineffective in counteracting the slip’s backward destabilization in these individuals. Differences between the legs revealed that our participants were asymmetrically impaired in their slip recovery response.
Dissertations / Theses on the topic "SWING STABILITY"
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Velez-Cedeno, Francisco Gerardo. "Multiple Swing Out-of-Step Relaying." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/40394.
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The reduced stability margin, at which power systems are being operated these days, has encouraged the power industry to come up with new ideas to guarantee a continuous and reliable operation of the bulk interconnected system. The development of the synchronized Phasor Measurement technology, and its deployment in several locations in the network, has introduced a promising means to protect power systems from undesired conditions.
This research effort describes a methodology to handle transient stability in power systems using Wide Area Measurements. A correct identification of transiently stable and unstable power oscillations can be achieved with the use of the Out-of-Step protection technique presented in this document. The development of this idea is explained through the analysis of small power system models, and tested in three different operating conditions of the state of California.
The main contribution of this research work, to the Out-of-Step relaying theory, is the identification of multiple unstable swings after a given disturbance. In other words, an Out-of-Step protection scheme that handles a network that behaves as a multi-machine system is presented.<br>Ph. D.
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CASTRO, MARCEL RENE VASCONCELOS DE. "MODELING OF VOLTAGE CONTROL AND MULTIPLE SWING BUSES IN VOLTAGE STABILITY ASSESSMENT." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=11320@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO<br>O crescente aumento da complexidade dos sistemas
elétricos
de potência gera
a necessidade de desenvolvimento de ferramentas que
melhorem as condições
de análise.
O objetivo deste trabalho é aprimorar a ferramenta
computacional de avaliação
das condições de segurança (ou estabilidade) de tensão.
No
que diz respeito às
barras associadas ao controle remoto de tensão por
geração
de potência
reativa, são propostos novos modelos que representam
mais
adequadamente as
condições operativas no momento do cálculo dos índices
de
segurança de
tensão. Em relação à barra associada ao controle local
de
tensão por geração
de potência reativa é proposta nova modelagem, aplicável
tanto no problema de
fluxo de potência, utilizando o método de Newton-
Raphson,
quanto no cálculo
dos índices de segurança de tensão. Este modelo,mais
robusto e flexível, inclui
o controle de tensão local da barra no problema geral de
fluxo de potência,
formando um sistema de equações de ordem (2*número de
barras+número de barras
controladas localmente). Para o tratamento de múltiplas
barras swing, é
proposto um novo modelo, de novo para representar mais
adequadamente as
condições operativas. É aplicável tanto no problema
básico
de fluxo de potência,
como no cálculo dos índices de segurança de tensão. O
modelo proposto
considera que apenas o ângulo de uma barra swing é
especificado, com os
ângulos das demais barras swing livres para variar.
Testes numéricos com sistemas-teste (5 e 6 barras)
comprovam a aplicabilidade
e adequação dos modelos propostos comparando-os aos
modelos usados
atualmente.<br>The crescent increase of the complexity of the electric
power systems generates
the need of development of tools to improve the analysis
conditions.
The objective of this work is to improve the computational
tool of voltage security
(stability) conditions assessment. As regards to the buses
associated to remote
voltage control by reactive power generation, new models
that represent more
appropriately the operatives conditions at the moment of
the calculations of the
voltage security indexes, are proposed. As regards to the
bus associated to local
voltage control by reactive power generation, it is
proposed a new modeling,
applicable as much in the power flow problem, using the
Newton-Raphson
method, as in the calculation of the voltage security
indexes. This model, more
robust and flexible, includes the local voltage control of
the bus in the general
power flow problem, constituting an equations system of
order (2*number of
system buses + number of buses with local voltage
control). As regard to the
multiples swing buses, it is proposed a new model, again
to represents more
appropriately the operatives conditions. It is applicable
as much in the basic
power flow problem, as in the calculation of the voltage
security indexes. The
proposed model considers that just one swing bus has your
voltage angle
specified and the others swing buses of the power system
have your voltage
angles free to vary.
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Siragy, Tarique. "The Role of Arm Swing on Dynamic Stability in People with Parkinson’s Disease." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/41997.
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Introduction: Idiopathic Parkinson’s Disease is a multisystem neurodegenerative disease that is characterized by asymmetric impairment in regions of the midbrain, forebrain, and brainstem. Of the known neurodegenerative diseases, Parkinson’s is the second most commonly diagnosed worldwide with a global prevalence expected to reach 9 million individuals by 2030. As fall rates range between 35-68% annually, falling during walking is amongst the primary concerns for this demographic. Interestingly, despite the close association between loss of arm swing (due to Parkinson’s Disease) and future falls, evidence to-date has not examined the effect different arm swing conditions have on walking stability during unperturbed and perturbed (cognitive and mechanical) conditions. Dynamic stability research in this demographic is further limited in that evidence examining differences between the least and most affected leg is sparse.
Research Objectives: To examine the differences between natural arm swing (unrestricted) and when arm swing was physical restricted (restricted) in people with Parkinson’s Disease. The effect of arm swing was assessed when people with Parkinson’s Disease walked in steady-state, dual-task, destabilizing terrains as well as in response to slips. Additionally, this thesis examined differences between the least and most affected sides, during the aforementioned conditions, that stem from the asymmetric progression in Parkinson’s Disease.
Methods: Twenty individuals with Parkinson’s Disease were recruited for this research. Individuals walked on a CAREN-Extended System with unrestricted (natural) and restricted (absent) arm swing. Arm conditions were combined with steady-state walking, walking while performing a secondary dual-task, walking on minor destabilizing environments (hilly, rocky and mediolateral translational), and in response to slips for the heel-strikes of the perturbed (slipped) leg and recovery (contralateral) leg. The minor destabilizing terrains were assessed separately to steady-state walking for the arm swing condition resulting in three types of analyses (arms-rocky, arms-rolling hills, and arms-mediolateral). Data were processed in Vicon, Visual 3D, and OpenSim before being exported to Matlab to calculate dynamic stability (Margin of Stability, Harmonic Ratios and Coefficient of Variation), average spatiotemporal parameters, as well as trunk linear and angular velocities. Statistical analyses were conducted in SPSS with a significance level set a priori at (p<0.05).
Results: During unperturbed walking with the restricted arm swing condition, compared to unrestricted, average trunk angular velocity increased in the transverse plane while instantaneous linear velocity at heel-strike decreased in the sagittal plane. Further, on the least affected leg, the Margin of Stability increased, average step length decreased, and coefficient of variation for step length increased. Contrastingly, step time coefficient of variation increased in the most affected leg. In the presence of the dual-task, average angular velocity in the frontal plane increased, average step time decreased (most affected leg), and step width coefficient of variation increased (bilaterally). Compared to unrestricted arm swing, restricted arm swing reduced average step length (arm-rolling hills) and time (arm-rocky), and increased COV step time (arm-rolling hills). The arm-rolling hills analysis revealed that the most affected leg had a shorter step length than the least affected. The destabilizing surface effects revealed that during the arm-rolling hills and arm-rocky analyses step time decreased, step width increased, and the COV for step time, length and width increased. No main effects occurred for the arm-mediolateral analysis. Additionally, when comparing the arm swing conditions in response to a slip, the restricted arm swing condition, compared to unrestricted, caused a faster step time during the slipped step. Compared to the most affected leg, the least affected had a wider step width during the slipped step. During the recovery step, the least affected leg had a larger anteroposterior Margin of Stability and longer step time than the most affected.
Conclusion: The findings revealed that when people with Parkinson’s Disease walk without arm swing, trunk rotational velocity increases which internally perturbs gait. This destabilization elicited unique responses from dynamic stability metrics that were specific to the terrain encountered. Since Parkinson’s Disease primarily affects movement timing, the results suggest that loss of arm swing is particularly perturbing to foot placement timing while changes in spatial foot placement reflect compensation to maintain an existing level of global dynamic stability and symmetry. Additionally, the evidence indicates that the independent behavior of the least and most affected leg respond uniquely to loss of arm swing. However, as people with Parkinson’s Disease adjust the least affected leg’s foot placement to mirror the contralateral leg, functional interlimb differences may only be revealed when individuals encounter perturbations.
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Mezher, Cézar. "The Effect of Arm Swing and Rocky Surface on Dynamic Stability In Healthy Young Adults." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40939.
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There are millions of fall-related injuries worldwide requiring medical attention on a yearly basis. These falls place a financial burden on the healthcare system. These falls can occur in the event of disruption in the postural control system and/or a loss of balance while walking. Previously, most gait studies have focused on the assessment of the lower extremities while neglecting the contribution of arm swing as it was believed to be a passive motion.
However, it has been shown that there is an active component to arm swing. Moreover, these arm movements have been shown to affect the motion of the center of mass when walking. Therefore, arm swing could mitigate the destabilizing effects of perturbations caused by challenging surfaces. Additionally, no studies have examined the effect of arm swing when walking on a rocky surface. This type of surface causes perturbations in the anteroposterior and mediolateral directions simultaneously, leading to uneven center of mass displacement and spatiotemporal modifications.
Hence, the present study assessed the effect of normal arm swing, held arm swing and active arm swing on postural control and dynamic stability when walking on regular and rocky surface. We hypothesized that active arm swing will have a negative impact on postural control and gait dynamics on a regular surface, while rocky surface walking will decrease stability and increase spatiotemporal variability. Additionally, we expect active arm swing to attenuate the negative effects of the rocky surface.
Fifteen healthy young adults from the University of Ottawa community (mean age 23.4 ± 2.8 years) were recruited to participate in this study. They were asked to walk using three different arm conditions (normal, held and active arm swing) on the dual-belt CAREN-Extended System (Motek Medical, Amsterdam, NL) on simulated regular and rocky surface. This last is generated using the “Rumble” module (maximum range of ±2 cm at 0.6 Hz vertically, ±1° at 1 Hz pitch, and ±1° at 1.2 Hz roll). Mean, standard deviation and maximal values of trunk linear and angular velocity were calculated in all three planes. Moreover, step length, time and width mean and coefficient of variation as well as margin of stability mean and standard deviation were calculated. A mixed linear model was performed to compare the effects of the arm swing motions and surface types. The arm and surface conditions were set as fixed effects, while the walking speed was set as a covariate.
Active arm swing increased trunk linear and angular velocity variability and peak values compared to normal and held arm conditions. Active arm swing also increased participants’ step length and step time, as well as the variability of margin of stability. Similarly, rocky surface walking increased trunk kinematics variability and peak values compared to regular surface walking. Furthermore, rocky surface increased the average step width while reducing the average step time.
The spatiotemporal adaptations show the use of “cautious” gait to mitigate the destabilizing effects of both the active arm swing and rocky surface walking and, ultimately, maintain stability.
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Yontz, Nicholas Allen. "Determining the Correlation Between Core Performance and Golf Swing Kinematics and Kinetics." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1281540237.
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Miranda, La Hera Pedro Xavier. "Contributions to Motion Planning and Orbital Stabilization : Case studies: Furuta Pendulum swing up, Inertia Wheel oscillations and Biped Robot walking." Licentiate thesis, Umeå : Umepå universitet, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1874.
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Alberto, Luís Fernando Costa. "O Princípio de Invariância de LaSalle estendido aplicado ao estudo de coerência de geradores e à análise de estabilidade transitória multi-'swing'." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-01102001-175455/.
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As técnicas de análise de estabilidade transitória em sistemas elétricos de potência desenvolveram-se significativamente nas últimas duas décadas. Atualmente, o principal desafio dos pesquisadores é a obtenção de técnicas que sejam adequadasa análises em tempo real. Neste sentido, as idéias de Liapunov associadas ao Princípio de Invariância de LaSalle têm sido utilizadas para estimar a bacia de atraçãoo dos sistemas de potência. Embora esta filosofia seja bastante adequada a análises de estabilidade em tempo real, existem alguns obstáculos que impedem a aplicação da mesma à análise de sistemas reais. Dentre estes obstáculos poder-se-ia destacar a impossibilidade de utilização de modelos mais realísticos e a limitação da análise ao primeiro "swing". Em verdade, estes obstáculos estão intimamente relacionados com as limitações do Princípio de Invariância de LaSalle. Para superar estes problemas, propõe-se, neste trabalho, uma extensão deste princípio que é mais geral e portanto mais flexível do que o original. Aproveitando esta maior flexibilidade, duas aplicações em análise de estabilidade transitória são abordadas, ambas com o objetivo de reduzir os obstáculos anteriormente mencionados. Na primeira, propõe-se uma nova função energia para sistemas de potência com perdas nas linhas de transmissão. Mostra-se que esta é uma função de Liapunov no sentido mais geral da extensão do Princípio de Invariância de LaSalle, podendo portanto ser empregada para estudos de estabilidade. Na segunda, uma metodologia de análise de estabilidade multi-"swing" é proposta com base em uma análise de coerência de geradores.
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Gillespie, Jennifer Ann. "Genetic Stability of a Genetically-Engineered Chimeric Porcine Circovirus (PCV) Vaccine, PCV1-2." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/31475.
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Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus associated disease (PCVAD), an economically important swine disease that causes wasting in pigs 5-18 weeks of age. There exist two different types of porcine circoviruses: porcine circovirus type 1 (PCV1) was discovered as a contaminant of porcine kidney (PK-15) cells and was determined to be nonpathogenic in swine; whereas porcine circovirus type 2 (PCV2) is pathogenic. A recently released vaccine for PCVAD was generated by inserting the gene encoding the immunogenic capsid protein of PCV2 into the genetic backbone of the non-pathogenic PCV1. This chimeric PCV vaccine, called PCV1-2, was shown to induce protective immunity against PCV2 infection in pigs. The vaccine is currently on the market in a killed form. In order to develop a live version of the vaccine, the genetic stability of the chimeric PCV1-2 vaccine virus was investigated by in vitro and in vivo passaging of the vaccine virus. In vitro passaging of the PCV1-2 vaccine virus was done in a porcine kidney PK-15 cell line. Cells were infected with the PCV1-2 vaccine virus and then serially passaged 11 times. The passaged vaccine viruses recovered from passages 5 and 11 were sequenced, and the sequences were compared to that of the original PCV1-2 vaccine virus. The in vitro serial passage result showed that no mutation occurred during the 11 in vitro passages. The in vivo passaging was done using specific-pathogen-free (SPF) pigs. In in vivo â passage 1â , nine piglets were divided into 3 groups of 3 each: group 1 each inoculated with 200ug of PCV1-2 plasmid, group 2 each with 1Ã 103 TCID50 live PCV1-2 vaccine virus, and group 3 each with 3ml phosphate buffered saline (PBS) buffer as a control. One pig from each group was necropsied at 14, 21, and 28 days post-inoculation (DPI), respectively. A panel of tissue samples including lymph nodes and thymus were collected from each pig. Tissue homogenates from DPI 28 that were positive by PCR for PCV1-2 DNA were used to inoculate new piglets in the in vivo passage 2 experiment. Viruses recovered from passage 2 pigs were subsequently used for inoculation in the in vivo passage 3 experiment. The PCV1-2 vaccine virus DNA from pigs in each passage was amplified and sequenced. The results of the in vivo serial passage experiment showed that, after 3 passages of the PCV1-2 vaccine virus in pigs, there were no new mutations in the viruses recovered from pigs. The PCV1-2 vaccine contained an introduced marker mutation at amino acid position number 79, which is in the capsid region. During the in vivo passaging of the vaccine virus in pigs, this marker mutation quickly reverted back to its original nucleotide. This marker back mutation occurred between DPI 21 and DPI 28 of passage 1 in the PCV1-2 live vaccine virus group, and between DPI 28 of passage 1 and DPI 14 of passage 2 in the PCV1-2 vaccine plasmid group, and remained stable throughout the reminder of the in vivo study. Based upon the results from this study, we conclude that the PCV1-2 chimeric vaccine virus is genetically stable in vitro and in pigs, and thus should serve as a good candidate for a live vaccine against PCV2.<br>Master of Science
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沈維華 and Weihua Shen. "Stability and absorption of milk-borne growth factors in the gastrointestinal tract of neonatal pigs." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31237642.
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Shen, Weihua. "Stability and absorption of milk-borne growth factors in the gastrointestinal tract of neonatal pigs /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19867943.
Full textBooks on the topic "SWING STABILITY"
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Berg, Andrew, and Rafael Portillo. Monetary Policy in Sub-Saharan Africa. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198785811.003.0001.
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Most countries in sub-Saharan Africa have made great progress in stabilizing inflation over the past two decades. In about half, a hard peg provides the nominal anchor. In the rest, which are the focus of this book, policymakers have more recently been asking more of monetary policy—to avoid policy misalignments and respond appropriately to shocks such as export and food price spikes and swings in fiscal policy—in support of overall stability and growth. And they are, in many cases, finding current regimes lacking, with opaque and sometimes inconsistent objectives, inadequate transmission of policy to the economy, and difficulties in responding to supply shocks. This chapter reviews this history and the analytic and policy challenges of modernizing monetary policy regimes in the region. Drawing on the results from the rest of this book, it charts a way forward.
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Scott, E. Hitchcock, and George E. Muñoz. Integrative Approaches to Healing. Edited by Shahla J. Modir and George E. Muñoz. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190275334.003.0029.
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Emotional balance and stability are important aspects of long-term abstinence from non-prescribed mood altering chemicals. Labiality (extreme mood swings) can contribute to relapse. This chapter challenges the traditional concept of healing, defined as a return to prior levels of functioning. Adverse childhood experiences, with their long-term contribution to adolescent and adult mood problems are noted. Interventions for adverse childhood experiences are recommended as part of the healing journey for emotional wellness. The limitations of traditional addiction treatment are discussed, as well as various possible detractors to good emotional health and sobriety. Interventions, processes, and various counseling theoretical practices are suggested for improving mood, emotional well-being, and sobriety. Ongoing assessment and monitoring of emotional well-being and relapse risk are critical. The quality of the relationship between the practitioner and patient is crucial in order to co-create a viable, individualized, holistic treatment plan.
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Ragsdale, Lyn, and Jerrold G. Rusk. The American Nonvoter. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780190670702.001.0001.
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The book explores the impact of uncertainty in the national campaign context on nonvoting in presidential and midterm House elections from 1920 through 2012. While previous studies have focused on individuals' motivations to vote and candidates' mobilization efforts, this book considers how uncertain national circumstances in the months before the election affect whether people vote or not. Uncertainty is defined as decision makers being unable to accurately predict future conditions, possible options, or final outcomes based on the current situation. Within the national campaign context, uncertainty arises from economic volatility, technological advances in mass communication, dramatic national events including wars, and changes in suffrage requirements. The book examines this uncertainty across four historical periods: the government expansion period (1920–1944), the post-war period (1946–1972), the government reassessment period (1974–1990), the internet technology period (1992–2012). The book considers the nature of politics during these periods with key occurrences including the economic swings of the Roaring 20s, the Great Depression, the post-World War II boom, and the Great Recession, voting rights for women, African-Americans, and young people, and the effects of radio, television, cable television, and the Internet on nonvoting. It concludes that the higher the degree of uncertainty in the national scene, the more likely eligible voters will go to the polls. Conversely, the lower the degree of uncertainty, as the national scene remains stable, the less likely eligible voters will participate. As one example, throughout all four historical periods, economic change decreases nonvoting, while economic stability increases nonvoting.
Book chapters on the topic "SWING STABILITY"
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"The Swing Equation and Its Solution." In Power System Stability. IEEE, 2010. http://dx.doi.org/10.1109/9780470545614.ch2.
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Dixon, Andrew. "Analytical methods for solving the “swing equation”." In Modern Aspects of Power System Frequency Stability and Control. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-816139-5.00006-0.
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Dixon, Andrew. "Numerical methods for solving the “swing equation”." In Modern Aspects of Power System Frequency Stability and Control. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-816139-5.00007-2.
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"The “exact solution” of the “swing equation”." In Modern Aspects of Power System Frequency Stability and Control. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-816139-5.00024-2.
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"4: Swing Low: The Stability of Periodic Orbits." In Mathematical Models and Their Analysis. Society for Industrial and Applied Mathematics, 2018. http://dx.doi.org/10.1137/1.9781611975277.ch4.
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Agbenyo Folly, Komla, Severus Panduleni Sheetekela, and Tshina Fa Mulumba. "Power System Small-Signal Stability Enhancement Using Damping Controllers Designed Based on Evolutionary Algorithms." In Genetic Algorithms [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.105591.
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This chapter is concerned with the stability enhancement of a power system using power system stabilizers (PSSs) designed based on four evolutionary algorithms (EAs), namely, genetic algorithms (GAs), breeder genetic algorithm (BGA), population-based incremental learning (PBIL), and differential evolution (DE). GAs have been widely applied in many fields of engineering and science and have shown to be a robust and powerful adaptive search algorithm. However, GAs are known to have several limitations. To deal with these limitations, many variant forms of GAs have been suggested often tailored to specific problems. In this research, we investigated the performances of GA-PSS and three other EAs-based PSSs (i.e., BGA-PSS and PBIL-PSS and DE-PSS) in improving the small-signal stability of a power system. These EAs have been selected on the basis of their simplicity, efficiency, and effectiveness in solving the optimization problem at hand. Frequency domain and time-domain simulation results show that DE-PSS, PBIL-PSS, and BGA-PSS performed better than GA-PSS. Time domain simulations suggest that overall, DE-PSS performs better than PBIL-PSS and BGA-PSS in terms of undershoot and subsequent swings, albeit with a relatively large first swing overshoot. The performances of BGA-PSS and PBIL-PSS are similar. On the other hand, GA-PSS gives a better response than the conventional PSS (CPSS).
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Kharola, Ashwani. "Control Optimisation of Overhead Gantry Cranes via Fuzzy Controllers." In Handbook of Research on Advancements in Manufacturing, Materials, and Mechanical Engineering. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4939-1.ch014.
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This study considers a fuzzy logic-based reasoning approach for control and optimising performance of overhead gantry crane. The objective of this study is to minimise load swing and to stabilise the crane in the least possible time. The fuzzy controllers were designed using nine Gaussian and triangular shape membership functions. The results clearly confirmed the effect of shape of memberships on performance of fuzzy controllers. Performance of overhead crane was measured in terms of settling time and overshoot ranges. The study also demonstrates the influence of varying mass of the load, mass of crane, and length of crane bar on stability of the crane. A mathematical model of the crane system has been derived to develop a simulink model of proposed system and performing simulations.
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Dixon, Andrew. "Initial analysis of the frequency control problem and a derivation of the swing equation." In Modern Aspects of Power System Frequency Stability and Control. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-816139-5.00004-7.
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GEORGE, DORAN. "OUT OF BALANCE: A YEAR OF DIALOGUE WITH KIRA O’REILLY TOWARD A MOVEMENT PRACTICE." In Kira O’Reilly: Untitled (Bodies). Intellect, 2018. http://dx.doi.org/10.1386/9781783208333_13.
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Frantic clockwork arms swing rigid, in arcs, below your shoulder, always less than 180°. It’s futile searching for a centre of balance, a place to balance the heels that are jerked up out of the floor on top of impossibly bent knees. The balls of your feet stab forwards and backwards along tracks etched out by a mean logic of the body in physical crisis. Fast concentration dips with your face, as torso, unyielding, grasping for stability, see-saws over your hips.
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"The “exact solution” of the “Swing Equation” when the power set point is not the nominal power output." In Modern Aspects of Power System Frequency Stability and Control. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-816139-5.00025-4.
Full textConference papers on the topic "SWING STABILITY"
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Sun, Andy. "Stability Theory of Swing Equations." In 2020 European Control Conference (ECC). IEEE, 2020. http://dx.doi.org/10.23919/ecc51009.2020.9143692.
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Velez, Francisco G., Virgilio A. Centeno, and Arun G. Phadke. "Multiple swing transient stability assessment with phasor measurements." In 2017 IEEE Manchester PowerTech. IEEE, 2017. http://dx.doi.org/10.1109/ptc.2017.7981173.
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Klimina, Liubov, and Alexander Formalskii. "On a Control to Pump a Swing." In 2022 16th International Conference on Stability and Oscillations of Nonlinear Control Systems (Pyatnitskiy's Conference) (STAB). IEEE, 2022. http://dx.doi.org/10.1109/stab54858.2022.9807467.
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Sebastian, Betsy, and Rachana Garg. "Transient stability analysis of multi-machine power system and first swing stability analysis using SVC." In 2014 International Conference on Advances in Electrical Engineering (ICAEE). IEEE, 2014. http://dx.doi.org/10.1109/icaee.2014.6838511.
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Omi, Takuya, Hiroto Kakisaka, Tomomi Sadakawa, and Shinichi Iwamoto. "Transient stability multi-swing step-out prediction with online anomaly detection." In TENCON 2016 - 2016 IEEE Region 10 Conference. IEEE, 2016. http://dx.doi.org/10.1109/tencon.2016.7848624.
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Chiku, Takahiro, Kaoni Nakamura, Yu Kurita, Shinichi Iwamoto, Hideo Hosogoe, and Mitsuhiro Matsumoto. "A novel generator output adjustment considering multi-swing transient stability ATC." In 2014 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC). IEEE, 2014. http://dx.doi.org/10.1109/appeec.2014.7066000.
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Amano, H., T. Kumano, and T. lnoue. "Nonlinear stability indices of power swing oscillation using normal form analysis." In 2006 IEEE Power Engineering Society General Meeting. IEEE, 2006. http://dx.doi.org/10.1109/pes.2006.1709010.
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Ajala, Olaoluwapo, Alejandro Dominguez-Garcia, Peter Sauer, and Daniel Liberzon. "A Second-Order Synchronous Machine Model for Multi-swing Stability Analysis." In 2019 North American Power Symposium (NAPS). IEEE, 2019. http://dx.doi.org/10.1109/naps46351.2019.9000368.
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Lee, Ho-Hoon. "A Robust Anti-Swing Trajectory Control of Overhead Cranes With High-Speed Load Hoisting: Simulation Study." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-10128.
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This paper proposes a new approach for the anti-swing trajectory control of overhead cranes that allows simultaneous high-speed load hoisting. The objective of this study is to design an anti-swing trajectory control scheme that is robust to unavoidable mechanical inaccuracies and installation errors such as locally sloped trolley rails. First, a coupled sliding surface is defined based on the load-swing dynamics, and then the stability of the coupled sliding surface is shown to be equivalent to that of trolley tracking errors. Next, a robust anti-swing trajectory control scheme, minimizing the coupled sliding surface asymptotically to zero, is designed based on the trolley and load-hoisting dynamics. Finally, the proposed control is extended to an adaptive scheme. In this study, the Lyapunov stability theorem is used as a mathematical design tool. The proposed control guarantees asymptotic stability of the anti-swing trajectory control while keeping all internal signals bounded. The proposed control provides a practical solution for the robustness problem caused by the usual mechanical inaccuracies and installation errors in application. The proposed control also provides clear gain-tuning criteria for easy application. The validity of the theoretical results is shown by computer simulation.
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Lee, Ho-Hoon, Del Segura, and Yi Liang. "A New Trajectory-Generation Scheme for Overhead Cranes With High-Speed Load Hoisting." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-59087.
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This paper proposes a new trajectory-generation scheme for a high-performance anti-swing control of overhead cranes, where the trajectory-generation problem is solved as a kinematic problem. First, a new anti-swing control law is designed based on the load-swing dynamics, for which the Lyapunov stability theorem is used as a mathematical tool. Then a new trajectory-generation scheme is proposed based on the anti-swing control law and typical crane operation in practice. For g iven hoisting motions, trolley-traveling trajectory references are computed based on the concept of minimum-time control, and then anti-swing trajectories are generated based on the trajectory references through the anti-swing control law. The new trajectory-generation scheme generates a typical anti-swing trajectory in industry with high-speed load hoisting. The effectiveness of the proposed trajectory-generation scheme is shown by generating high-performance anti-swing trajectories with high hoisting speed and hoisting ratio.
Reports on the topic "SWING STABILITY"
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Kanner, Joseph, Dennis Miller, Ido Bartov, John Kinsella, and Stella Harel. The Effect of Dietary Iron Level on Lipid Peroxidation of Muscle Food. United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7604282.bard.
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Biological oxidations are almost exclusively metal ion-promoted reactions and in ths respect iron, being the most abundant, is the commonly involved. The effect of dietary iron levels on pork, turkey and chick muscle lipid peroxidation and various other related compounds were evaluated. Crossbred feeder pigs were fed to market weight on corn-soy rations containing either 62, 131 or 209 ppm iron. After slaughter, the muscles were dissected, cooked and stored at 4°C. Heavily fortifying swine rations with iron (>200 ppm) increase nn-heme iron (NHI), thiobarbituric acid reactive substances (TBARS), and decrease a-tocopherol in cooked stored pork but did not increase warmed-over aroma (WOA). NHI and TBARS were higher in cooked pork from pigs fed high-iron diets. Liver iron correlated with muscle iron. TBARS were strongly related with WOA. The role of dietary vitamin E and ascorbic acid on Fe-induced in vivo lipid peroxidation in swine was also evaluated. Moderate elevation in iron stores had a marked effect on oxidative stress, especially as indicated by liver TBARS. Supplemental vitamin E, and to a lesser extent vitamin C, protect against this oxidative stress. Unsupplementation of Fe in the regular diet of turkeys did not affect body weight, blood hemoglobin level, or iron pool in the liver or muscle. The reason being that it contained "natural" ~120 mg Fe/kg feed, and this amount is high enough to keep constant the pool of iron in the body, liver or muscle tissues. Only Fe-supplementation with high amounts of Fe (500 ppm) significantly increased turkey blood hemoglobin and total iron in the liver, in 1 out of 3 experiments, but only slightly affects iron pool in the muscles. It seems that the liver accumulates very high concentations of iron and significantly regulates iron concentration in skeletal muscles. For this reason, it was very difficult to decrease muscle stability in turkeys through a diet containing high levels of Fe-supplementation. It was shown that the significant increase in the amount of iron (total and "free") in the muscle by injections with Fe-dextran accelerated its lipid peroxidation rate and decreased its a-tocopherol concentration. The level and metabolism of iron in the muscles affects the intensity of in vivo lipid peroxidation. This process was found to ifluence the turnover and accumulation of a-tocopherol in turkey and chick muscles. Treatments which could significantly decrease the amount and metabolism of iron pool in muscle tissues (or other organs) may affect the rate of lipid peroxidation and the turnover of a-tocopherol. Several defense enzymes were determined and found in the turkey muscle, such as superoxide dismutase, catalase, and glutathione peroxidase. Glutathione peroxidase was more active in muscles with a high trend of lipid peroxidation, lmore so in drumsticks than in breast muscles, or muscles with a low a-tocopherol content. The activity of glutathione peroxidase increased several fold in muscle stored at 4°C. Our work demonstrated that it will be much more practical to increase the stability of muscle tissues in swine, turkeys and chickens during storage and processing by increasing the amount of vitamin E in the diet than by withdrawing iron supplementation.