Top PDF Relationship Between Velocity of Contraction and Force Applied On Air Muscles

Relationship Between Velocity of Contraction and Force Applied On Air Muscles

Relationship Between Velocity of Contraction and Force Applied On Air Muscles

Air muscles are simple pneumatic devices that have high potential to be used as robotic manipulators, as they have a behavior similar to biological motors or muscles. Hence, they have a wide range of potential applications in areas such as robotics, bio-robotics, biomechanics, and artificial limb replacements. In addition to the similarity to biological muscle, air muscles have the advantages of good power-to-weight ratio, being compliant, and low cost. This thesis primarily quantifies the relationship between velocity of contraction of air muscles and the force applied on it, which is a key characteristic of biological skeletal muscle. First, an experimental test rig was used to measure the velocity of contraction of air muscles as a function of applied force, supply pressure, and supply volumetric flow rate. Second, a theoretical model is proposed to quantify the relationship between the velocity of contraction and force applied on it and to explain the experimental results.
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Alternative splicing, muscle contraction and intraspecific variation: associations between troponin T transcripts, Ca2+ sensitivity and the force and power output of dragonfly flight muscles during oscillatory contraction

Alternative splicing, muscle contraction and intraspecific variation: associations between troponin T transcripts, Ca2+ sensitivity and the force and power output of dragonfly flight muscles during oscillatory contraction

Muscle temperature was monitored with a fine-gauge thermocouple implanted in the center of the thorax. The contractile performance of some preparations began to degrade between initial tests at 28 °C and the target test Fig. 1. (A) The basalar muscle (BM) of the mesothorax exposed by removal of a portion of the cuticle and underlying air sacs. The viewpoint is looking posteriorly from the rear margin of the head and slightly above the dragonfly; the base of the left forewing is visible near the upper right. White arrows show the lateral edges of the humeral plate, around which incisions were made to isolate the basalar muscle mechanically for studies of contractile performance. (B) Sample trace of wing position and velocity from a recording made using a laser distance sensor on the base of the forewing. (C) Photograph showing a dragonfly attached by its ventral thorax to a narrow glass beam (not visible) that extends from a strain gauge. A fine-gauge thermocouple and EMG electrodes are inserted into the thorax. The laser distance sensor is shown at the upper right. We have drawn a red line to depict the laser beam striking a white spot painted at the base of the right forewing. (D) Diagram showing the geometry of the basalar muscle attachment to the base of the forewing, an approximation of the EMG recording electrodes (these are differential electrodes referenced to a third electrode in the abdomen that is not shown) and the method used to calculate wing position from the laser distance sensor.
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Quantifying the effect of age and contraction mode on the force-velocity-power relationship in the knee extensors

Quantifying the effect of age and contraction mode on the force-velocity-power relationship in the knee extensors

to many of these prior studies (67-73y; 90-120°) seems likely to account for these differences. A 12 year longitudinal study of older participants of 71 years of age reported a 2-2.5% annual decrease of muscle strength in the knee extensors [15] and therefore there can be significant differences within a decade of aging for participants over ~65 years of age. It has been suggested the effects of age on muscle architecture could shift the torque-angle relationship (T-A) compared to a younger muscle [140]. However, similar torque-angle profiles between younger and older in the knee extensors have been reported [21,63], with others demonstrating a T-A relationship plateau occurring between 110 – 90° [16,25] and thus our knee angle of 80° is just slightly less than optimal. Utilizing the interpolated twitch technique to assess voluntary activation (VA), the younger and older men were able to activate their knee extensors to a similar degree, ~96%, in agreement with previous reports in the knee extensors [9,45,63] and various other muscles investigated with adult aging [8,10,51,159-161]. Thus, central activation does not appear to be a limiting factor indicating peripheral alterations likely being the predominant source of age-related muscle weakness. These peripheral factors may include reduced overall muscle mass [2,21,38,40,55], selective atrophy of type II muscle fibers [60,162], musculo-tendinous architecture changes [17,140,163], excitation- contraction uncoupling [139], or reduced intrinsic contractile capacity of muscle fibers [42,142].
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Effect of Dietary Nitrate on Force Production and Sarcoplasmic Reticulum Ca2+ Handling in Rat Fast Twitch Muscles Following Eccentric Contraction

Effect of Dietary Nitrate on Force Production and Sarcoplasmic Reticulum Ca2+ Handling in Rat Fast Twitch Muscles Following Eccentric Contraction

performed as described previously [11]. Briefly, an animal was placed in the su- pine position on a supporting platform, with the left foot secured in a foot hold- er attached to the rim of a servomotor. Further, the knee was secured using a strap such that the foot was positioned perpendicular to the lower leg. A pair of sterilized needle electrodes was inserted through aseptically prepared skin to stimulation of the peroneal nerve in the left leg that innervates the left extensor digitorum longus (EDL) and tibialis anterior (TA) muscles. The correct location of the needles was confirmed by the dorsiflexion of the ankle joints and exten- sion of the toes in response to the electrical stimulation of the common peroneal nerve. Repetitive contractions of the EDL and TA muscles were induced by elec- trical stimuli applied to the common peroneal nerve. In addition, muscle con- tractions were elicited by stimulating the peroneal nerve using a 1000-ms train of 1-ms pulse at 50 Hz and supramaximal voltage. For the ECC protocol, the ex- perimental leg was forcibly extended with the servomotor at an angular velocity of 150˚ s −1 from the ankle joint, from 30˚ to 180˚, in synchrony with the electric-
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Modeling the Force Velocity Relationship in Arm

Modeling the Force Velocity Relationship in Arm

from skeletal muscle during maximum tension depends on several internal and external factors. Internal factors are e.g. anatomical structure of muscle (cross sectional area, pennation etc.), fiber type distribution (fast and slow twitch muscle fibers have different force-velocity equations), condition of the muscle (fatigue, training) and muscle length. External factors are e.g. contraction type (isometric, concentric and eccentric) and contraction ve- locity (rate of change of muscle length). Good reviews of the above mentioned factors have been presented, e.g. [4,7,8]. Force (F) creates a moment about the joint which is moment arm multiplied by force (M = r × F). Length of muscle’s moment arm depends on joint angle and it changes as the rotation movement proceeds about the joint axis. The combined effect of the forces of several different muscles produces the rotation movement about the joint axis.
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Is there Relationship between Pectoralis Minor Muscle Length and Shoulder Rotator Muscles Strength?

Is there Relationship between Pectoralis Minor Muscle Length and Shoulder Rotator Muscles Strength?

special warming workouts for 10 minutes. Following the warming, the athletes were taken to the isokinetic device one by one for measurement and the device was adjusted according to their individual anthropometric structures. During the test, their weights were entered in the computer and the program was set. The suitability of the movement ranges of the joint to be tested to the angles that are to be tested was determined by making the athletes do a sample movement at a very low speed. The joint angles were adjusted in the assessment by considering the joint movement ranges of the persons and the measurement characteristics of the device. A concentric-concentric strength measurement was made for the shoulder IR/ER movement between the angles of 0° ER and 90° IR [Figure.1].
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Relationship between anthropometric parameters and throwing velocity in water polo players

Relationship between anthropometric parameters and throwing velocity in water polo players

Water polo is a collective sport and efforts of high intensity are made in less duration, where the players must swim, jump, and send the ball with moments of rest or low intensity. The necessity of greater, stronger, and faster players is supported by the development in the anthropometric characteristics. The aim of this study was to establish the importance of the anthropometric factors in the throwing velocity (v), evaluated on 22 players pertaining to Spanish Selection of water polo. The references to the anthropometric profile were measured according to the protocol of the International Working Group of Kinanthropometry (ISAK), considered by literature as those recommended to characterize a population of sportsmen. The conditional evaluation was centered on the evaluation of the specific v of three types of shootings, in the swimming pool and from the distance of 5 m. The v were measured whit radar (Inc., Flat StalkerPro), with a frequency of registry of 100 Hz and with 0.045 sensitivity of m·s −1 . The results show that the higher v is reached with the throwing without goalkeeper and the lower v in the throwing with goalkeeper. The corporal size through the Body Mass Index (BMI) (r=0.5), circumference of the arm (r=0.5), biacromial breadth (r=0.5) and the femur breadth (r=0.6) correlate with the throwing v with goalkeeper in players of water polo. The corporal size is confirmed as an important factor to arrive at the high performance in water polo (p<0.05).
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The Relationship Between Child Infant Mortality And Air Pollution

The Relationship Between Child Infant Mortality And Air Pollution

Air pollution is a global emergency that affects the health of society. Considered environmental pollutants inhaled by human threat to the health persons at totally stages of life, whether city or rural areas, and affect the results on the newborn babies in particular because they are suffering from feeble weak.

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Relationship between the Severity of Airway Obstruction and Inspiratory Muscles Dysfunction in COPD Patients

Relationship between the Severity of Airway Obstruction and Inspiratory Muscles Dysfunction in COPD Patients

Daneshvari Hospital were evaluated. These patients were in a stable condition during the study and did not experience the exacerbation of symptoms for the past 2 weeks. There was no change in their medications and all patients were examined by the same body plethysmography device and the same technician. Results are presented as mean ± SD. Statistical analysis was performed by using student t- test. Linear regression test was used for evaluating the correlation between FEV1 and respiratory muscles and respiratory drive tests (especially TTI and its components).

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The nervous system does not compensate for an acute change in the balance of passive force between synergist muscles

The nervous system does not compensate for an acute change in the balance of passive force between synergist muscles

The present study confirmed previous observations (Hirata et al., 2015; Le Sant et al., 2017) that passive dorsiflexion induces a much larger increase in shear modulus (stiffness) for GM (+657.6± 257.7%) than for GL (+488.7±257.9%) and SOL (+106.6±93.0%) (Fig. 2). As a strong linear relationship between changes in muscle shear modulus and changes in passive muscle force exists (Koo et al., 2013; Maïsetti et al., 2012), this result strongly suggests that the distribution of passive force across the heads of the triceps surae is different when the ankle is dorsiflexed versus plantarflexed. However, this interpretation requires two methodological considerations. First, the measurement of shear modulus is sensitive to the angle between the muscle fibres and the ultrasound transducer, and therefore to the pennation angle (Eby et al., 2013; Gennisson et al., 2010; Koo and Hug, 2015). As such, differential changes in pennation angle between the muscles during passive dorsiflexion could have induced differential changes in shear modulus for the same change in passive force. However, the change in pennation angle during passive dorsiflexion is of low magnitude (between 2 and 12 deg; Abellaneda et al., 2008; Maganaris et al., 1998; Rana et al., 2013), with negligible differences between muscles (Maganaris et al., 1998; Rana et al., 2013). Therefore, we are confident that the different changes in shear modulus between the three muscles are strongly related to different changes in passive force. Second, the quantification of the balance of passive force between muscles requires the consideration of muscle cross-sectional area. For instance, if two muscles exhibit the same change in shear modulus during stretching, the bigger muscle will exhibit the larger change in passive force. In the present study, we found a greater thickness for GM than for GL, which is in accordance with magnetic resonance imaging studies showing that GM cross-sectional area is 2 times larger than that of GL (Fukunaga et al., 1996). Together with the larger increase in shear modulus for GM, we are confident that there is a higher imbalance of passive force between GM and GL when the ankle is dorsiflexed versus plantarflexed. It is more challenging to interpret the balance of force between SOL and gastrocnemii because the volume of SOL is 2.6 and 5.4 times larger than that of GM and GL, respectively (Albracht et al., 2008), but its increase in shear modulus during passive dorsiflexion was much smaller than that of GM and GL (6.2 and 4.6 times for GM and GL, respectively). Therefore, we cannot determine whether the force was more or less balanced between SOL and gastrocnemii at the dorsiflexed position but we can reasonably conclude that this balance was modified towards a higher proportion of gastrocnemii passive force. In the present
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DEPARTMENT OF THE AIR FORCE

DEPARTMENT OF THE AIR FORCE

1.2.7.3. Air Force Medical Logistics Office/Engineering, Facilities, Equipment & Procurement Branch (AFMLO/FOM) provides Planning, Programming, and Budgetary guidance, direction and oversight as required to the MAJCOMs for using appropriated funds for medical SRM projects. 1.3. Scope. This instruction provides general procedures for planning, programming, and executing O&M-funded projects for real property classified as maintenance, repair or unspecified minor military construction. It applies to all projects, including, but not limited to, those planned for accomplishment by organic forces (which include overhires and temporary duty augmentees), troop labor, or contract (includ- ing Simplified Acquisition of Base Engineer Requirements (SABER)). This instruction addresses only O&M-funded unspecified minor military construction, facilities for operational requirements, and main- tenance and repair projects for real property. These funds are normally in the 3400 appropriation (3740 for AFRC and 3840 for ANG), but may include 3600, Research, Development, Test and Evaluation (RDT&E); Working Capital Fund (WCF); or Defense SRM accounts when made available for O&M pur- poses. See AFI 32-1001, Operations Management, for guidance on functions at the installation level.
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DEPARTMENT OF THE AIR FORCE HEADQUARTERS AIR FORCE CIVIL ENGINEER SUPPORT AGENCY

DEPARTMENT OF THE AIR FORCE HEADQUARTERS AIR FORCE CIVIL ENGINEER SUPPORT AGENCY

6.1.1.1. The primary ICS IAM must have Information Assurance Technical (IAT) Level II or Information Assurance Management (IAM) Level I certification in accordance with DOD 8570.01-M, Information Assurance Workforce Improvement Program, within six months of BCE appointment. (Note: Security+ certification satisfies either IAT Level II or IAM Level I certification.) If the CEG or CES has IT support personnel, it is recommended that the BCE assign an IT system administrator as the primary ICS IAM. Many Air Force CE IT specialists have IAT Level I or higher certification. In addition to the primary ICS IAM, an alternate ICS IAM must be appointed to assist the primary with the functional and technical aspects of ICSs. The alternate ICS IAM must be a qualified ICS operator/technician, and IAT/IAM certification is desired but not required. The alternate ICS IAM’s primary role is to provide the necessary technical support/expertise to the primary ICS IAM to achieve ICS IA certification and accreditation. These two individuals will leverage each other’s expertise to achieve IA of our ICSs.
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DEPARTMENT OF THE AIR FORCE HEADQUARTERS AIR FORCE CIVIL ENGINEER SUPPORT AGENCY

DEPARTMENT OF THE AIR FORCE HEADQUARTERS AIR FORCE CIVIL ENGINEER SUPPORT AGENCY

To ensure the confidentiality of a system, a determination needs to be made as to whether a user has the appropriate credentials to access a system or network. The need-to-know principle is determined by the necessity for access to, knowledge, or possession of specific official DOD information required to carry out official duties. The need-to-know determination is derived from a decision made by an authorized holder of official information that a prospective recipient requires access to specific official information to carry out official duties. Need-to-know principles are applied to systems within DOD and appropriate measures must be in place to verify and authorize individuals at all levels. This can be accomplished using various methods such as denying access after multiple unsuccessful logon attempts; however, stringent controls must be in place to standardize this process. If automated authentication methods cannot be employed due to reasons such as OS type or age then other methods of access control must be incorporated to mitigate any risk to the system or enclave. An example of a mitigating technique is the use of more stringent physical security where only those personnel with appropriate credentials can physically access system or enclave resources. Any risk-mitigation method such as this should be identified in the appropriate checklist or concept of operations (CONOPS) for the system or enclave.
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AIR FORCE INSTITUTE OF TECHNOLOGY

AIR FORCE INSTITUTE OF TECHNOLOGY

3.9.2 Validation. The OPNET model is validated by running test cases where no routing protocol is used with two nodes in the ad hoc network. Using IEEE 802.11g for the MAC layer, 10 VoIP data streams are sent across the network from node 1 to node 2. The size of the streams are fixed at 200 bytes while the distance between the nodes is increased from 10 m to 600 m in various increments resulting in a total of 14 different tests. As shown in Table 3.5, packet loss begins when the nodes approach 400 m of separation and increases as the distance increases. At approximately 550 m apart, the nodes drop more than 99% of all packets, and at 566 m, 100% packet loss is reached.
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Net Force F = γ3ma at High Velocity

Net Force F = γ3ma at High Velocity

Newton’s theory of gravitation has been outdated by relativity theory explaining specific phe- nomena like perihelion precession of Mercury, light deflection and very recently the detection of gravitational waves. But the disappearance of the obvious gravitational force and the variation of time are arguable concepts difficult to directly prove. Present methodology is based on hypotheses as expressed in a previous article: a universal time and an inertial mass variable according to the Lorentz factor (which could not be envisioned at Newton’s age). Because this methodology is mainly stood on Newtonian mechanics, it will be called neo-Newtonian mechanics. This theory is in coherence with the time of the Quantum Mechanics. In Newtonian mechanics, all forces, includ- ing gravitational force, are deducted from the linear momentum. Introducing the variable inertial mass, the result of the demonstration is an updated expression of the net force at high velocity: F = γ 3 m g a. If such a factor in γ 3 can look a bit strange at first sight for a force, let us remind that the lost
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The relationship between endogenous serum insulin concentration and glucose uptake in the forearm muscles of nondiabetics

The relationship between endogenous serum insulin concentration and glucose uptake in the forearm muscles of nondiabetics

obtained: (a) A highly significant correlation between muscular glucose uptake and simultaneous arterial serum insulin concentration. (b) No correlation between glucose uptake and simultaneous arterial blood glucose concentration during hyperglycemia. (c) A maximal insulin effect on muscular glucose uptake at arterial serum insulin concentrations at about 200 µU/ml. This observation is, however, based on only a few experiments.

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Headquarters U.S. Air Force. Secretary of the Air Force Office Small Business Programs

Headquarters U.S. Air Force. Secretary of the Air Force Office Small Business Programs

Defense for Acquisition, Technology & Logistics (AT&L) calls for establishing new SB career field effective 1 Oct 2014.. 6..[r]

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United States Air Force

United States Air Force

appetite for Air Force ISR 3 – we simply do not have the capacity to fulfill it. To meet as much of the demand as possible, Airmen work 10- to 12-hour shifts on a “7-on, 1-off” pattern, flying over 900 hours a year – a rate that can accumulate a career’s worth of flying hours in a single assignment. These are combat shifts, physically, mentally, and emotionally taxing…and to get it done, they are sometimes diverted from training that allows them to improve, advance, and build a professional military career. When such Airmen are faced with the decision to separate or continue to serve, it is difficult to convince them that staying is in their best interests. We are losing them at a rate faster than we can replace them.
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AIR FORCE INSTITUTE OF TECHNOLOGY

AIR FORCE INSTITUTE OF TECHNOLOGY

Investigation of the optical and electrical behavior of some semiconductors at very high temperatures has not been an area of much study, at least not experimentally. The importance of such research becomes obvious due to the effects of high temperatures on semiconductor devices such as infrared detectors and light emitters. Besides the destructive effects of thermal stress and melting, changes in the optical properties of the material can greatly affect device performance. In this research, the infrared absorption of Si, Ge, GaAs, GaSb, InAs, and InP was measured from 0.6 to 25 µm at temperatures ranging from 295 up to 900 K, using a Fourier Transform InfraRed (FTIR) spectrometer in combination with a custom-designed heater assembly. The band gap shift was estimated from the experimental results and compared to existing data. There was good agreement between the two results. For GaSb and InAs, data was taken at higher temperatures than what was found in the literature. That data provides an extension of existing theory to a higher temperature range. Free-carrier absorption was also observed and was compared to existing data. Temperature dependent expressions were developed for the band gap energy and free-carrier absorption in Si, Ge, GaAs, GaSb, InAs, and InP.
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Force Velocity Relations in the Intact Dog Heart

Force Velocity Relations in the Intact Dog Heart

Emphasizing the importance of muscle length upon the force-velocity relations of the heart muscle, they presented evidence of an inverse relation between instantaneous force and velocity[r]

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