Academic literature on the topic 'Length of stretch'

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Journal articles on the topic "Length of stretch"

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Adekoya, A. O., M. B. Fetuga, T. A. Ogunlesi, A. O. Adekoya, O. O. Oba-Daini, and E. D. Ajibola. "Flaccid penile length and stretch factor in the newborn." Research Journal of Health Sciences 9, no. 1 (April 7, 2021): 23–29. http://dx.doi.org/10.4314/rejhs.v9i1.3.

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Objective: Little is known about the flaccid penile length in the newborn and the degree of stretch of the penis among investigators while measuring the stretched penile length. This study aimed to document the flaccid penile length and the stretch factor in the newborn.Methods: This cross-sectional study was carried out on 200 term male infants within the first 72 hours of life. The flaccid penile length and the stretched penile length were measured with a wooden spatula and the stretch factor was calculated.Results: The mean (±SD) flaccid and stretched penile length were 30.9 ± 3.8 mm and 38.9 ± 4.0 mm respectively. The mean stretch factor was 26.4 %. Both testes had the same mean volume of 1.6 ± 0.5 ml. There was a significant correlation between flaccid and stretched penile lengths (r = 0.775, p = 0.000). The flaccid penile length was a significant predictor of the stretched penile length.Conclusion: This study has been able to determine the stretch factor while measuring the flaccid and stretch penile lengths in Nigerian newborn infants. It is recommended that the flaccid penile length be measured along with the stretched penile length and determine the stretch factor in order to compare how much investigators stretch the penis during measurement. This will allow for detailed comparison of penile anthropometry across different ethnic groups and races. Keywords: flaccid penile length, newborn, stretch factor, stretched penile length.
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Rassier, Dilson E., Eun-Jeong Lee, and Walter Herzog. "Modulation of passive force in single skeletal muscle fibres." Biology Letters 1, no. 3 (June 28, 2005): 342–45. http://dx.doi.org/10.1098/rsbl.2005.0337.

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In this study, we investigated the effects of activation and stretch on the passive force–sarcomere length relationship in skeletal muscle. Single fibres from the lumbrical muscle of frogs were placed at varying sarcomere lengths on the descending limb of the force–sarcomere length relationship, and tetanic contractions, active stretches and passive stretches (amplitudes of ca 10% of fibre length at a speed of 40% fibre length/s) were performed. The passive forces following stretch of an activated fibre were higher than the forces measured after isometric contractions or after stretches of a passive fibre at the corresponding sarcomere length. This effect was more pronounced at increased sarcomere lengths, and the passive force–sarcomere length relationship following active stretch was shifted upwards on the force axis compared with the corresponding relationship obtained following isometric contractions or passive stretches. These results provide strong evidence for an increase in passive force that is mediated by a length-dependent combination of stretch and activation, while activation or stretch alone does not produce this effect. Based on these results and recently published findings of the effects of Ca 2+ on titin stiffness, we propose that the observed increase in passive force is caused by the molecular spring titin.
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Minozzo, Fabio C., and Dilson E. Rassier. "Effects of blebbistatin and Ca2+ concentration on force produced during stretch of skeletal muscle fibers." American Journal of Physiology-Cell Physiology 299, no. 5 (November 2010): C1127—C1135. http://dx.doi.org/10.1152/ajpcell.00073.2010.

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When activated muscle fibers are stretched at low speeds [≤2 optimal length ( Lo)/s], force increases in two phases, marked by a change in slope [critical force (Pc)] that happens at a critical sarcomere length extension ( Lc). Some studies attribute Pc to the number of attached cross bridges before stretch, while others attribute it to cross bridges in a pre-power-stroke state. In this study, we reinvestigated the mechanisms of forces produced during stretch by altering either the number of cross bridges attached to actin or the cross-bridge state before stretch. Two sets of experiments were performed: 1) activated fibers were stretched by 3% Lo at speeds of 1.0, 2.0, and 3.0 Lo/s in different pCa2+ (4.5, 5.0, 5.5, 6.0), or 2) activated fibers were stretched by 3% Lo at 2 Lo/s in pCa2+ 4.5 containing either 5 μM blebbistatin(+/−) or its inactive isomer (+/+). All stretches started at a sarcomere length (SL) of 2.5 μm. When fibers were activated at a pCa2+ of 4.5, Pc was 2.47 ± 0.11 maximal force developed before stretch (Po) and decreased with lower concentrations of Ca2+. Lc was not Ca2+ dependent; the pooled experiments provided a Lc of 14.34 ± 0.34 nm/half-sarcomere (HS). Pc and Lc did not change with velocities of stretch. Fibers activated in blebbistatin(+/−) showed a higher Pc (2.94 ± 0.17 Po) and Lc (16.30 ± 0.38 nm/HS) than control fibers (Pc 2.31 ± 0.08 Po; Lc 14.05 ± 0.63 nm/HS). The results suggest that forces produced during stretch are caused by both the number of cross bridges attached to actin and the cross bridges in a pre-power-stroke state. Such cross bridges are stretched by large amplitudes before detaching from actin and contribute significantly to the force developed during stretch.
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Joumaa, V., F. Bertrand, S. Liu, S. Poscente, and W. Herzog. "Does partial titin degradation affect sarcomere length nonuniformities and force in active and passive myofibrils?" American Journal of Physiology-Cell Physiology 315, no. 3 (September 1, 2018): C310—C318. http://dx.doi.org/10.1152/ajpcell.00183.2017.

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The aim of this study was to determine the role of titin in preventing the development of sarcomere length nonuniformities following activation and after active and passive stretch by determining the effect of partial titin degradation on sarcomere length nonuniformities and force in passive and active myofibrils. Selective partial titin degradation was performed using a low dose of trypsin. Myofibrils were set at a sarcomere length of 2.4 µm and then passively stretched to sarcomere lengths of 3.4 and 4.4 µm. In the active condition, myofibrils were set at a sarcomere length of 2.8 µm, activated, and actively stretched by 1 µm/sarcomere. The extent of sarcomere length nonuniformities was calculated for each sarcomere as the absolute difference between sarcomere length and the mean sarcomere length of the myofibril. Our main finding is that partial titin degradation does not increase sarcomere length nonuniformities after passive stretch and activation compared with when titin is intact but increases the extent of sarcomere length nonuniformities after active stretch. Furthermore, when titin was partially degraded, active and passive stresses were substantially reduced. These results suggest that titin plays a crucial role in actively stretched myofibrils and is likely involved in active and passive force production.
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Chapple, W. D. "Mechanics of stretch in activated crustacean slow muscle. I. Factors affecting peak force." Journal of Neurophysiology 62, no. 5 (November 1, 1989): 997–1005. http://dx.doi.org/10.1152/jn.1989.62.5.997.

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1. The active stiffness of ventral superficial abdominal muscle (VSM) of the hermit crab, Pagurus pollicarus, was measured with ramp stretches of different amplitudes and velocities. Active stiffness was calculated by subtracting the peak force produced by passive stretch and the isometric force just before stretch from the peak force produced by stretching active muscle. The result was then divided by stretch length to give stiffness. 2. The relationship between force just before stretch (the level of activation) and active stiffness was curvilinear and was found to apply under a variety of experiment conditions. For pooled data from eight experiments, active stiffness (GN.m-2.m-1) = 3.2*stress (MN/m2)-7.6*stress2. Decreasing the number of motor units or activating the inhibitor did not alter this relationship nor did the addition of proctolin, octopamine, or 5-HT to the bath. The relationship also applied during the rising phase of isometric tension. However, stiffness declined more rapidly than predicted by this relationship after the end of tetanus. 3. Active stiffness varied inversely with stretch amplitude for fast stretches, and the slope of this relationship increased with increasing muscle activation. At lower stretch velocities, the slope was much less than at rapid stretch velocities, so at low levels of activation and stretch velocity, active stiffness was essentially independent of stretch length. 4. Active stiffness covaried with muscle force as both were sampled at shorter and shorter lengths on the ascending limb of the length-tension curve.(ABSTRACT TRUNCATED AT 250 WORDS)
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Azizi, Emanuel, and Emily M. Abbott. "Anticipatory motor patterns limit muscle stretch during landing in toads." Biology Letters 9, no. 1 (February 23, 2013): 20121045. http://dx.doi.org/10.1098/rsbl.2012.1045.

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To safely land after a jump or hop, muscles must be actively stretched to dissipate mechanical energy. Muscles that dissipate energy can be damaged if stretched to long lengths. The likelihood of damage may be mitigated by the nervous system, if anticipatory activation of muscles prior to impact alters the muscle's operating length. Anticipatory motor recruitment is well established in landing studies and motor patterns have been shown to be modulated based on the perceived magnitude of the impact. In this study, we examine whether motor recruitment in anticipation of landing can serve a protective function by limiting maximum muscle length during a landing event. We use the anconeus muscle of toads, a landing muscle whose recruitment is modulated in anticipation of landing. We combine in vivo measurements of muscle length during landing with in vitro characterization of the force–length curve to determine the muscle's operating length. We show that muscle shortening prior to impact increases with increasing hop distance. This initial increase in muscle shortening functions to accommodate the larger stretches required when landing after long hops. These predictive motor strategies may function to reduce stretch-induced muscle damage by constraining maximum muscle length, despite variation in the magnitude of impact.
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Willems, Mark E. T., and William T. Stauber. "Effect of Contraction History on Torque Deficits by Stretches of Active Rat Skeletal Muscles." Canadian Journal of Applied Physiology 27, no. 4 (August 1, 2002): 323–35. http://dx.doi.org/10.1139/h02-018.

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Effects of contraction history on torque deficits by stretches of active skeletal muscles were examined. After three contractions using maximal and submaximal activation (80 and 20 Hz) at an ankle position of 40° (i.e., long muscle length) and with maximal activation at 120° (i.e., short muscle length), the isometric and stretch torques (15 stretches) of rat plantar flexor muscles (bout 1) were measured. Controls were unconditioned. Stretches (i.e., ankle rotation from 90° to 40°, velocity: 50°•s−1) were imposed on maximal isometric contractions at 90° (i.e. preloaded stretches). All groups performed a second bout following 2 hours of rest after bout 1. After maximal contractions at long muscle length, preload torque at 90° and stretch torque at 40° for stretch 1 of bout 1 were 25% and 18% lower than the other groups. However, for all groups, bout 1 ended and bout 2 began and ended with similar isometric and stretch torques. Stretches early in bout 2, with preloads similar to stretches in bout 1, had greater stretch torques resulting in larger torque deficits. Torque deficits, possibly caused by damage to muscle structures and excitation-contraction uncoupling, were not prevented by a history of isometric contractions. Different contraction histories can result in similar isometric torques but different stretch torques. Key words: injury, warm-up, isometric contractions, prevention, eccentric contractions
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Rassier, Dilson E., and Ivan Pavlov. "Force produced by isolated sarcomeres and half-sarcomeres after an imposed stretch." American Journal of Physiology-Cell Physiology 302, no. 1 (January 2012): C240—C248. http://dx.doi.org/10.1152/ajpcell.00208.2011.

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When a stretch is imposed to activated muscles, there is a residual force enhancement that persists after the stretch; the force is higher than that produced during an isometric contraction in the corresponding length. The mechanisms behind the force enhancement remain elusive, and there is disagreement if it represents a sarcomeric property, or if it is associated with length nonuniformities among sarcomeres and half-sarcomeres. The purpose of this study was to investigate the effects of stretch on single sarcomeres and myofibrils with predetermined numbers of sarcomeres ( n = 2, 3. . . , 8) isolated from the rabbit psoas muscle. Sarcomeres were attached between two precalibrated microneedles for force measurements, and images of the preparations were projected onto a linear photodiode array for measurements of half-sarcomere length (SL). Fully activated sarcomeres were subjected to a stretch (5–10% of initial SL, at a speed of 0.3 μm·s−1·SL−1) after which they were maintained isometric for at least 5 s before deactivation. Single sarcomeres showed two patterns: 31 sarcomeres showed a small level of force enhancement after stretch (10.46 ± 0.78%), and 28 sarcomeres did not show force enhancement (−0.54 ± 0.17%). In these preparations, there was not a strong correlation between the force enhancement and half-sarcomere length nonuniformities. When three or more sarcomeres arranged in series were stretched, force enhancement was always observed, and it increased linearly with the degree of half-sarcomere length nonuniformities. The results show that the residual force enhancement has two mechanisms: 1) stretch-induced changes in sarcomeric structure(s); we suggest that titin is responsible for this component, and 2) stretch-induced nonuniformities of half-sarcomere lengths, which significantly increases the level of force enhancement.
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Fasciano, Robert W., and Leslie Tung. "Factors governing mechanical stimulation in frog hearts." American Journal of Physiology-Heart and Circulatory Physiology 277, no. 6 (December 1, 1999): H2311—H2320. http://dx.doi.org/10.1152/ajpheart.1999.277.6.h2311.

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Because stretch-induced activation may be important in generating clinically relevant arrhythmias in the heart, we delineated the ability of different types of stretches to activate ventricular tissue. Geometrically simple sheets of frog ( Rana catesbeiana) ventricular tissue were mounted to allow stretches to be applied perpendicular to one edge. Every heart could be activated by a stretch pulse ( n = 25), and several parameters were varied to determine their effects on mechanical activation threshold. At shorter coupling intervals, a larger stretch was needed to excite the tissue, and activation-recovery intervals were shorter, similar to previously published electrically probed strength-interval and restitution relations. Additionally, the tissue became easier to activate as the speed of the stretch increased from 0.09 to 2.6% length/ms. The increment in stretch needed for activation decreased as the baseline stretch increased from 0 to 6% length. Thus we show that mechanical activation is similar to electrical activation and that increasing uniquely mechanical parameters such as the speed of the applied stretch or baseline level of stretch can decrease the mechanical activation threshold.
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Matsumoto, H., C. B. Baron, and R. F. Coburn. "Smooth muscle stretch-activated phospholipase C activity." American Journal of Physiology-Cell Physiology 268, no. 2 (February 1, 1995): C458—C465. http://dx.doi.org/10.1152/ajpcell.1995.268.2.c458.

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Rabbit aortic muscles were stretched from a holding length of 0.6 maximum length (Lmax) to lengths as great as 1.0 Lmax and the new length maintained. When muscles were stretched to 1.0 Lmax, inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] and inositol 1,4-bisphosphate [Ins(1,4)P2] contents were increased at 375 ms (uncorrected for freezing time) poststretch to 209 +/- 27 and 139.8 +/- 12% (SE), respectively, of control values. Increases in Ins(1,4,5)P3 and Ins(1,4)P2 contents reached an apparent maximum at approximately 500 ms, i.e., to 243.7 +/- 15.8 and 180.9 +/- 16.2% of control, and were decreased to near control levels at 1,700 ms poststretch. The stretch threshold for phospholipase C (PLC) activation was 0.85 Lmax. The latency to onset of PLC activation, correcting for the time for freezing, was 275 to 375 ms. Maximal PLC activity was 91 pmol.s-1.100 nmol total lipid P(i)-1, which corresponded to 10% of total phosphatidylinositol bisphosphate being hydrolyzed per second. The mechanism of stretch-activated PLC activity involved influx of Ca2+ via gadolinium-sensitive ion channels, but not via nifedipine-sensitive ion channels.
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Dissertations / Theses on the topic "Length of stretch"

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Lane, William Todd. "Effects of dynamic, static stretch, and proprioceptive neuromuscular facilitation on running velocity, step length, and step rate." Click here to access thesis, 2005. http://www.georgiasouthern.edu/etd/archive/fall2005/todd%5Fw%5Flane/lane%5Ftodd%5Fw%5F200508%5FMS.pdf.

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Thesis (M.S.)--Georgia Southern University, 2005.
"A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science in the Department of Public Health" ETD. Includes bibliographical references (p. 37-41) and appendices.
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Varea, Emilien. "Experimental analysis of laminar spherically expanding flames." Phd thesis, INSA de Rouen, 2013. http://tel.archives-ouvertes.fr/tel-00800616.

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Laminar burning velocity is very useful for both combustion modeling and kinetic scheme validationand improvement. Accurate experimental data are needed. To achieve this, the spherical flame method was chosen. However various expression for burning velocity from the spherically expanding flame can be found. A theorical review details all the expressions and models for the burning veolcity and shows how they can be obtained experimentally. These models were comparated considering basic fuels - various Lewis numbers. As a result, it is shown that the pure kinematic measurement method is the only one thet does not introduce any assumptions. This kinematic measurement had needed the development and validation of an original post-processing tool. Following the theorical review, a parametric experimental study is presented. The new technique is extended to extract burning velocity and Markstein length relative to the fresh gas for pure ethanol, isooctane and blended fuels at high pressure.
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Brequigny, Pierre. "Influence de la nature du carburant sur la combustion en moteur à allumage commandé : impact de l’étirement de flamme." Thesis, Orléans, 2014. http://www.theses.fr/2014ORLE2038/document.

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Dans un contexte de diminution des émissions polluantes émises par les moteurs à combustion interne, le secteur des transports assiste à une amélioration des motorisations mais également à une diversification des carburants pour l’automobile. L’utilisation de ces différents carburants entraîne souvent un impact sur les performances de la combustion. Dans le cas du moteur à allumage commandé, la performance dépend du dégagement d’énergie, image de la vitesse de la combustion, soit du front de flamme consommant le mélange air-carburant. Or toute flamme en expansion est théoriquement soumise à des effets de courbure et de cisaillement, toutes deux contributions de l’étirement. La réponse à l’étirement étant propre à chaque type de mélange air-carburant (lié au carburant proprement dit, à la richesse du mélange, à la dilution …), ce travail de thèse est centré sur la compréhension de l’impact de l’étirement sur les performances des carburants dans les moteurs à allumage commandé. Pour cela, différents mélanges air-carburant similaires du point de vue des propriétés thermodynamiques et des vitesses fondamentales de combustion laminaire mais avec des sensibilités à l’étirement différentes ont été sélectionnés. Ces mélanges ont ensuite été étudiés dans différentes configurations expérimentales et à l’aide de différentes techniques de mesure: moteur monocylindre opaque et à accès optiques, chambre sphérique de combustion turbulente. Les résultats montrent que les propriétés de sensibilités à l’étirement déterminées en régime laminaire comme la longueur de Markstein et le nombre de Lewis sont indicatrices du comportement des mélanges en combustion turbulente, comme dans la chambre de combustion caractéristique des moteurs à allumage commandé, et sont des paramètres à prendre en considération afin de prédire les performances plus globales de ces carburants que ce soit expérimentalement qu’en simulation
In a context of decreasing pollutant emissions, the transport sector is facing an improvement of engine concept as well as a fuel diversification. The use of these different fuels often involves an impact on the combustion performance itself. In the case of Spark ignition engine, the efficiency is a function of the released heat, image of the combustion speed, i.e. the flame front speed consuming the air-fuel mixture. It is well known that every expanding flame is submitted to flame curvature and strain rate which are both contributors to flame stretch. As the answer of each air-fuel mixture (i.e. the fuel itself, the equivalence ratio, the dilution …) is different to flame stretch, the objective of this work is to understand flame stretch impact on fuel performance in Spark-Ignition engines. To achieve this goal, different fuel-air mixtures with similar unstretched laminar burning speed and thermodynamic properties but different responses to stretch were selected. Those mixtures were then studied with different experimental devices with different measurement techniques: single-cylinder metallic and optical engines, turbulent combustion spherical vessel. Results show that flame stretch sensitivity properties such as Markstein length and Lewis number, determined in laminar combustion regime, are relevant parameters to describe the flame propagation in turbulent combustion as in the combustion chamber of the Spark-Ignition engine and need to be taken into consideration to evaluate global performance of these fuels, experimentally and also in modeling simulation
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Das, Suma Rani. "Investigation of Design and Operating Parameters in Partially-Filled Rubber Mixing Simulations." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1479151141596147.

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De, Vries Jaap. "A STUDY ON SPHERICAL EXPANDING FLAME SPEEDS OF METHANE, ETHANE, AND METHANE/ETHANE MIXTURES AT ELEVATED PRESSURES." 2009. http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-601.

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High-pressure experiments and chemical kinetics modeling were performed for laminar spherically expanding flames for methane/air, ethane/air, methane/ethane/air and propane/air mixtures at pressures between 1 and 10 atm and equivalence ratios ranging from 0.7 to 1.3. All experiments were performed in a new flame speed facility capable of withstanding initial pressures up to 15 atm. The facility consists of a cylindrical pressure vessel rated up to 2200 psi. Vacuums down to 30 mTorr were produced before each experiment, and mixtures were created using the partial pressure method. Ignition was obtained by an automotive coil and a constant current power supply capable of reducing the spark energy close to the minimum ignition energy. Optical cine-photography was provided via a Z-type schlieren set up and a high-speed camera (2000 fps). A full description of the facility is given including a pressure rating and a computational conjugate heat transfer analysis predicting temperature rises at the walls. Additionally, a detailed uncertainty analysis revealed total uncertainty in measured flame speed of approximately +-0.7 cm/s. This study includes first-ever measurements of methane/ethane flame speeds at elevated pressures as well as unique high pressure ethane flame speed measurements. Three chemical kinetic models were used and compared against measured flame velocities. GRI 3.0 performed remarkably well even for high-pressure ethane flames. The C5 mechanism performed acceptably at low pressure conditions and under-predicted the experimental data at elevated pressures. Measured Markstein lengths of atmospheric methane/air flames were compared against values found in the literature. In this study, Markstein lengths increased for methane/air flames from fuel lean to fuel rich. A reverse trend was observed for ethane/air mixtures with the Markstein length decreasing from fuel lean to fuel rich conditions. Flame cellularity was observed for mixtures at elevated pressures. For both methane and ethane, hydrodynamic instabilities dominated at stoichiometric conditions. Flame acceleration was clearly visible and used to determine the onset of cellular instabilities. The onset of flame acceleration for each high-pressure experiment was recorded.
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Books on the topic "Length of stretch"

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Parker, Philip M. The 2007-2012 World Outlook for Womens, Misses, and Girls Stretch and Non-Stretch Knee-Length Sheer Finished Hosiery. ICON Group International, Inc., 2006.

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Parker, Philip M. The 2007-2012 Outlook for Womens, Misses, and Girls Stretch and Non-Stretch Knee-Length Sheer Finished Hosiery in India. ICON Group International, Inc., 2006.

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Parker, Philip M. The 2007-2012 Outlook for Womens, Misses, and Girls Stretch and Non-Stretch Knee-Length Sheer Finished Hosiery in Greater China. ICON Group International, Inc., 2006.

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Parker, Philip M. The 2007-2012 Outlook for Womens, Misses, and Girls Stretch and Non-Stretch Knee-Length Sheer Finished Hosiery in the United States. ICON Group International, Inc., 2006.

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The effects of body segment length and head position upon sit and reach flexibility performance. 1992.

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The effects of body segment length and head position upon sit and reach flexibility performance. 1992.

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The effects of body segment length and head position upon sit and reach flexibility performance. 1992.

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Cazeneuve, Cécile, and Alexandra Durr. Genetic and Molecular Studies. Oxford University Press, 2014. http://dx.doi.org/10.1093/med/9780199929146.003.0006.

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Huntington’s disease (HD) is a rare inherited neurologic disorder due to a single mutational mechanism in a large gene (HTT). The mutation is an abnormal CAG repeat expansion, which is translated to a polyglutamine stretch in the huntingtin protein. The growing field of repeat expansion disorders benefits greatly from the lessons learned from the role of the CAG repeat expansion in HD and its resulting phenotype–genotype correlations. The molecular diagnosis can be difficult, and there are some pitfalls for accurate sizing of the CAG repeat, especially in juvenile HD and for intermediate alleles. Correlation between CAG length and age of onset accounts for up to 72% of the variance in different populations, but the search for genes modifying age of onset or progression of HD is still ongoing.
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Farb, Benson, and Dan Margalit. Pseudo-Anosov Theory. Princeton University Press, 2017. http://dx.doi.org/10.23943/princeton/9780691147949.003.0015.

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This chapter focuses on the construction as well as the algebraic and dynamical properties of pseudo-Anosov homeomorphisms. It first presents five different constructions of pseudo-Anosov mapping classes: branched covers, constructions via Dehn twists, homological criterion, Kra's construction, and a construction for braid groups. It then proves a few fundamental facts concerning stretch factors of pseudo-Anosov homeomorphisms, focusing on the theorem that pseudo-Anosov stretch factors are algebraic integers. It also considers the spectrum of pseudo-Anosov stretch factors, along with the special properties of those measured foliations that are the stable (or unstable) foliations of some pseudo-Anosov homeomorphism. Finally, it describes the orbits of a pseudo-Anosov homeomorphism as well as lengths of curves and intersection numbers under iteration.
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Acevedo, Butcher Carmen, ed. Following Christ: A lenten reader to stretch your soul. Brewster, Mass: Paraclete Press, 2009.

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Book chapters on the topic "Length of stretch"

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Rassier, Dilson E., and Clara Pun. "Stretch and Shortening of Skeletal Muscles Activated Along the Ascending Limb of the Force–Length Relation." In Advances in Experimental Medicine and Biology, 175–89. New York, NY: Springer New York, 2010. http://dx.doi.org/10.1007/978-1-4419-6366-6_10.

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Erman, Burak, and James E. Mark. "Segmental Orientation." In Structures and Properties of Rubberlike Networks. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195082371.003.0013.

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Segmental or molecular orientation refers to the anisotropic distribution of chain-segment orientations in space, due to the orienting effect of some external agent. In the case of uniaxially stretched rubbery networks, which will be the focus of this chapter, segmental orientation results from the distortion of the configurations of network chains when the network is macroscopically deformed. In the undistorted state, the orientations of chain segments are random, and hence the network is isotropic because the chain may undertake all possible configurations, without any bias. In the other hypothetically extreme case of infinite degree of stretching of the network, segments align exclusively along the direction of stretch. The mathematical description of segmental orientation at all levels of macroscopic deformation is the focus of this chapter. Segmental orientation in rubbery networks differs distinctly from that in crystalline or glassy polymers. Whereas the chains in glassy or crystalline solids are fully or partly frozen, those in an elastomeric network have the full freedom to go from one configuration to another, subject to the constraints imposed by the network connectivity. The orientation at the segmental level in glassy or crystalline networks is mostly induced by intermolecular coupling between closely packed neighboring molecules, while in the rubbery network intramolecular conformational distributions predominantly determine the degree of segmental orientation. The first section of this chapter describes the state of molecular deformation. In section 11.2, the simple theory of segmental orientation is outlined, followed by the more detailed treatment of Nagai and Flory. The chapter concludes with a discussion of infrared spectroscopy and the birefringence technique for measuring segmental orientation. For uniaxial deformation, the deformation tensor λ takes the form λ = diag(λ, λ-1/2, λ-1/2), where diag represents the diagonal of a square matrix, and λ is the ratio of the stretched length of the rubbery sample to its undeformed reference length. The first element along the diagonal of the matrix represents the extension ratio along the direction of stretch, which may be conveniently identified as the X axis of a laboratory-fixed frame XYZ. The other two elements refer to the deformation along two lateral directions, Y and Z.
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Michie, Helena, and Robyn Warhol. "Introduction: adventures in the archives." In Love Among the Archives, 1–61. Edinburgh University Press, 2015. http://dx.doi.org/10.3366/edinburgh/9781474406635.003.0001.

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The album is huge. Depending on which librarian brings it to the circulation desk, you might be offered a cart to carry it to your seat in the British Library Reading Room or you might have to tote it yourself. Its vertical length is at least two feet; its width nearly as great. The covers are a dusty red-brown, faded and scratched, and the binding is broken so that the album must be tied with a flat cord to keep it from falling open when lifted. Inside, musty pages of heavy paper require you to stretch out your whole arm to turn them. Neatly affixed to the pages in rough chronological order are a variety of items in card stock: calling cards with the names of English dukes and duchesses in elaborate scripted fonts; handwritten menus for French meals served in grand country houses; seating charts for dinners large and small; printed bills of fare for restaurant banquets. The pages, despite their slight yellowing and a faint but perceptible yellowish smell, have an aura of faded opulence.
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"Lengthen, align and stretch." In Beginning AutoCAD 2005, 206–11. Routledge, 2012. http://dx.doi.org/10.4324/9780080940700-33.

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"Lengthen, align and stretch." In Beginning AutoCAD 2002, 207–12. Routledge, 2012. http://dx.doi.org/10.4324/9780080499970-34.

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"Conservation, Ecology, and Management of Catfish: The Second International Symposium." In Conservation, Ecology, and Management of Catfish: The Second International Symposium, edited by TIMOTHY F. BONVECHIO, MICHEAL S. ALLEN, DAN GWINN, and JASON S. MITCHELL. American Fisheries Society, 2011. http://dx.doi.org/10.47886/9781934874257.ch33.

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<em>Abstract</em>.—Recent modeling indicates that increased exploitation on nonnative flathead catfish <em>Pylodictis olivaris</em> may be an avenue for native species recovery. Flathead catfish were illegally introduced into the Satilla River, Georgia, and negative impacts have occurred on native fishes. In an effort to aid in the restoration of native fish on the Satilla River, the Georgia Department of Natural Resources initiated an intensive electrofishing removal effort. In this study, we evaluated the changes in flathead catfish total mortality, condition, and size structure from those efforts. From 2007 to 2009, 13,472 flathead catfish totaling 19,337 kg were removed along a 129-km stretch of the Satilla River. The population size structure changed substantially from containing many large individuals (59% 510 mm total length [TL]) in 2007 to mainly small fish (79% 356 mm TL) by 2009. Total biomass per effort declined from 57.05 kg/h in 2007 to 19.96 kg/h in 2009. Mean individual weight of fish removed decreased from 2.64 kg in 2007 to 1.32 kg in 2008 to 0.61 kg in 2009. Population age structure was also truncated, but there was evidence for higher recruitment and earlier maturation, which would require that intensive harvest be maintained to prevent the population from rebuilding within 2–5 years. Catch-curves revealed increasing total annual mortality rates of 37, 48 and 52%, for 2007–2009, respectively. Considering the life history of the flathead catfish, being a long-lived species that presumably cannot withstand excessive rates of exploitation (i.e., greater than 25% exploitation), our results indicated that an electrofishing removal program is a reasonable management option for areas where this apex predator has been introduced, but continual removal may be required to maintain low biomass.
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Henikoff, Jorja G. "Assembling Blocks." In Pattern Discovery in Biomolecular Data. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780195119404.003.0007.

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A block is an ungapped local multiple alignment of amino acid sequences from a group of related proteins. Ideally, the contiguous stretch of residues represented by a block is conserved for biological function. Blocks have depth (the number of sequences) and width (the number of aligned positions). There are currently several useful programs for finding blocks in a group of related sequences that I do not discuss in detail here. Among these, Motif (Smith et al., 1990) and Asset (Neuwald and Green, 1994) both align blocks on occurrences of certain types of patterns found in the sequences; Gibbs (Lawrence et al., 1993; Neuwald et al., 1995) and MEME (Bailey and Elkan, 1994) both look for statistically optimal local alignments; and Macaw (Schuler et al., 1991) and Somap (Parry-Smith and Attwood, 1992) both give the user assistance in finding blocks interactively. After candidate blocks are identified by a block-finding method, they can be evaluated and assembled into a set representing the protein group, resulting in a multiple alignment consisting of ungapped regions separated by unaligned regions of variable length. The block assembly process is the subject of this chapter. Both the Blocks (Henikoff and Henikoff, 1996a) and Prints (Attwood and Beck, 1994) databases consist of such sets of blocks and between them currently represent 1,163 different protein groups. These collections of blocks are more sensitive and efficient for classifying new sequences into known protein groups than are collections of individual sequences, as demonstrated by comprehensive evaluations (Henikoff and Henikoff, 1994b, 1997), by genomic studies (Green et al., 1993), and by individual studies (Posfai et al., 1988; Henikoff, 1992, 1993; Attwood and Findlay, 1993; Pietrokovski, 1994; Brown, 1995). Issues that must be addressed during block assembly include the number of blocks provided to the assembly module by the block finders, block width, the number of times a block occurs in each sequence (zero to many), overlap of blocks, and the order of multiple blocks within each sequence. Once these issues are decided, it is necessary to score individual competing blocks and then competing sets of blocks.
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Dumas, Alexandre. "The Cemetery of the Château d’If." In The Count of Monte Cristo. Oxford University Press, 2008. http://dx.doi.org/10.1093/owc/9780199219650.003.0021.

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On the bed, at full length, and faintly lit by the pale ray that entered by the window, was visible a sack of coarse cloth, under the large folds of which were stretched a long and stiffened form; it was Faria’s last winding-sheet—a winding-sheet...
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Zola, Émile. "Chapter 4." In A Love Story. Oxford University Press, 2017. http://dx.doi.org/10.1093/owc/9780198728641.003.0024.

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Leaning back in his armchair, Malignon stretched out his legs before the roaring fire and waited patiently. He’d gone to the lengths of closing the curtains and lighting the candles. The first room where he was sitting was brightly illuminated with a little chandelier...
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Ahmed, Tarem, Al-Sakib Khan Pathan, and Supriyo Shafkat Ahmed. "Learning Algorithms for Anomaly Detection from Images." In Biometrics, 281–308. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0983-7.ch013.

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Visual surveillance networks are installed in many sensitive places in the present world. Human security officers are required to continuously stare at large numbers of monitors simultaneously, and for lengths of time at a stretch. Constant alert vigilance for hours on end is difficult to maintain for human beings. It is thus important to remove the onus of detecting unwanted activity from the human security officer to an automated system. While many researchers have proposed solutions to this problem in the recent past, significant gaps remain in existing knowledge. Most existing algorithms involve high complexities. No quantitative performance analysis is provided by most researchers. Most commercial systems require expensive equipment. This work proposes algorithms where the complexities are independent of time, making the algorithms naturally suited to online use. In addition, the proposed methods have been shown to work with the simplest surveillance systems that may already be publicly deployed. Furthermore, direct quantitative performance comparisons are provided.
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Conference papers on the topic "Length of stretch"

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Omar, Hamzeh W., and Harini G. Sundararaghavan. "Effects of Cytoskeletal Tension on Chick Dorsal Root Ganglia." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14585.

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About 50,000 cases of peripheral nerve injuries occur annually [1] resulting in patient pain or loss of touch. Methods of repairing peripheral nerve gaps is essential for aiding in patient recovery. During development, growth, and joint movement, nerves are exposed to mechanical tension that is hypothesized to aid in their growth. Neurons can grow less than .5–1 mm/day but are known to grow up to ∼3 cm/day during development, theorized from factors of stretch on cell cytoskeleton during growth [2,3]. Our focus was to investigate the effects of mechanical strain on nerve growth. We fabricated biodegradable, electrospun, polycaprolactone (PCL) scaffolds to create three-dimensional, nanofibrous networks for Dorsal Root Ganglia (DRG) neuron extension and growth. To test the effects of scaffold stretch and tension on DRG growth, scaffolds were stretched using a custom scaffold stretcher. DRG growth was investigated for 3mm changes in scaffold length on days 0 and 1 of DRG development. Further investigation of DRG growth on day 2 and 3 as well as stretches of 6 and 9mm are being performed. In addition, an incremental stretch test for total stretches of 3, 6, and 9mm will be performed.
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Parks, J. E., C. P. Pantelides, L. F. Ibarra, and D. H. Sanders. "Seismic Anchorage of Dry Storage Casks Using Stretch Length Anchors." In Structures Congress 2017. Reston, VA: American Society of Civil Engineers, 2017. http://dx.doi.org/10.1061/9780784480427.045.

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Webster, William C., Kostas Lambrakos, Jangwhan Kim, and Xiaoning Jing. "Rod Dynamics With Large Stretch." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83889.

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In the last few decades, the use of synthetic fiber line in mooring systems has become increasingly popular, for instance in composite moors consisting of wire rope, polyester line and chain. Synthetic fiber lines are noted for their large stretch which can under high load be as much as 10 to 20 percent of their unloaded length or more. In developing a consistent model for the motions of a moored offshore platform using composite moors, it is necessary to model the dynamics of the moor recognizing that some elements may exhibit large stretch. The model for the dynamics of a rod without stretch was developed by Garrett (1982). This model has been frequently extended to the case with small stretch by linearizing the stretch term in the compatibility equation, for instance, Paulling & Webster (1986). The research presented here is an extension of Garrett’s theory to include the possibility of large stretch. With the adoption of a simple assumption concerning the character of the stretch, and with the incorporation of visco-elastic behavior of the large-stretch elements given by Kim, Kyoung & Sablok (2010), large stretch can be introduced consistently with few changes in the traditional finite-element scheme. Finally, the effects of large stretch on the physical properties and dynamics of the rod are also discussed.
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Foley, Christopher W., Jerry Seitzman, and Tim Lieuwen. "Analysis and Scalings of Blowoff Limits of 2D and Axisymmetric Bluff Body Stabilized Flames." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-70048.

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This paper considers shear layer flame stabilization with a particular focus on velocity scaling of blowoff limits. Analysis of the expression for hydrodynamic flame stretch, κ, in a shear layer shows that it consists of two contributions, associated with normal and shearing flow strain. These two contributors lead to flame stretch scalings of SL/δ and U/L, respectively, where δ and L denote shear layer thickness and characteristic geometric length scale. These two flame stretch terms have different velocity and length scalings (roughly U1/2 and U1, respectively) and so different blowoff trends can be expected depending upon which term dominates. These scalings are used to interpret a variety of bluff body blowoff data in the literature by analyzing the velocity and length scale dependence of extinction stretch rates calculated at the measured blowoff conditions. We also show that the measured velocity sensitivities to chemical time at blowoff range from U−0.3 to U−1.6. A key point of this study is that blowoff boundaries do not necessarily follow a U−1 scaling suggested by classical Damköhler number scalings and that more work is needed to understand the controlling extinction processes of near-blowoff flames.
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Sirignano, William A., Arash Zandian, and Fazle Hussain. "Mechanisms of Liquid Stream Breakup: Vorticity and Time and Length Scales." In ILASS2017 - 28th European Conference on Liquid Atomization and Spray Systems. Valencia: Universitat Politècnica València, 2017. http://dx.doi.org/10.4995/ilass2017.2017.4616.

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The 3D, temporal instabilities on a planar liquid jet are studied using DNS with level-set and VoF interface-capturingmethods. The λ2 method has been used to relate the vortex dynamics to the surface dynamics at different stages of the jet breakup. The breakup character depends on the Ohnesorge number (Oh) and gas-to-liquid density ratio. At high Reynolds number (Re) and high Oh, hairpin vortices form on the braid and overlap with the lobe hairpins, thinning the lobes, which then puncture creating holes and bridges. The bridges break, creating ligaments that stretch and break into droplets by capillary action. At low Oh and high Re, lobe stretching and thinning is hindered by high surface tension and splitting of the original Kelvin-Helmholtz vortex, preventing early hole formation. Corru- gations form on the lobe edges, influenced by the split vortices, and stretch to form ligaments. Both mechanisms are present in a transitional region in the We-Re map. At lower Re and not-too-large Weber number (We), lobe stretching occurs but with longer and larger ligaments in this third domain which has a hyperbolic transition to the hole formation domain as We increases. The three domains with differing breakup behaviors each occupy distinct portions of a plot of We based on gas density versus Re based on liquid properties. Characteristic times for the hole formation, as well as the lobe and ligament stretching are different - the former depending on the surface tensionand the latter on liquid viscosity. In the transitional region, both times are of the same order.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4616
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Ho, Clifford K., Siri S. Khalsa, and Nathan P. Siegel. "Analytical Methods to Evaluate Flux Distributions From Point-Focus Collectors for Solar Furnace and Dish Engine Applications." In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90054.

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This paper introduces a new analytical “stretch” function that accurately predicts the flux distribution from on-axis point-focus collectors. Different dish sizes and slope errors can be assessed using this analytical function with a ratio of the focal length to collector diameter fixed at 0.6 to yield the maximum concentration ratio. Results are compared to data, and the stretch function is shown to provide more accurate flux distributions than other analytical methods employing cone optics.
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Maas, Jürgen, Martin Griese, and Thorben Hoffstadt. "Integrated Sensor Concepts for Dielectric Elastomer Actuators." In ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3243.

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Actuators based on dielectric electroactive polymers (DEAP) use the electrostatic pressure to convert electric energy into strain energy. Besides this, they are also predestined for sensor applications to monitor the actual stretch state based on the deformation dependent capacitive-resistive behavior of the DEAP. Considering DEAP actuators for positioning applications, like stack- or roll-actuators, the actual position, length or stretch of the actuator is required for a precise control. Thus, integrated sensors made of DEAP can be used to determine the actual stretch state with sufficient accuracy and high dynamics on the one hand. On the other hand the electrical behavior of the DEAP transducer itself can be evaluated for the estimation of the stretch state representing a sensor-less concept. In this paper at first the state of the art of sensor-based and sensor-less concepts for determining the stretch state of DEAP transducers is presented. Afterwards the authors propose novel concepts for DEAP-based sensors integrated into stack- and roll-actuators. These concepts are compared with each other in terms of sensitivity, accuracy, dynamics and integration efforts for the realization. Finally, fundamental concepts, estimation algorithms and different approaches for monitoring the actual stretch state are presented based on the electrical parameters of a lossy DEAP transducer, which are suitable both for sensor-based and sensor-less concepts.
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Venkateswaran, Prabhakar, Andrew D. Marshall, David R. Noble, Jerry M. Seitzman, and Tim C. Lieuwen. "Turbulent Consumption Speed Scaling of H2/CO Blends." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-45401.

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This paper describes measurements and analysis of global turbulent consumption speeds, ST,GC, of hydrogen/carbon monoxide (H2/CO) mixtures. The turbulent flame properties of such mixtures are of fundamental interest because of their strong stretch sensitivity and of practical interest since they are the primary constituents of syngas fuels. Data are analyzed at mean flow velocities and turbulence intensities of 4 < U0 < 50 m/s and 1 < u′rms/SL,0 < 100, respectively, for H2/CO blends ranging from 30–90% H2 by volume. Data from two sets of experiments are reported. In the first, fuel blends ranging from 30–90% H2 and mixture equivalence ratio, Φ, were adjusted at each fuel composition to have nominally the same un-stretched laminar flame speed, SL,0. In the second set, equivalence ratios were varied at constant H2 levels. The data clearly corroborate results from other studies that show significant sensitivity of ST,GC to fuel composition. For example, at a fixed u′rms, ST,GC of a 90% H2 case (at Φ = 0.48) is a factor of three times larger than the baseline Φ = 0.9, CH4/air mixture that has the same SL,0 value. We also describe physics-based correlations of these data, using leading points concepts and detailed kinetic calculations of their stretch sensitivities. These results are used to develop an inequality for negative Markstein length flames that bounds the turbulent flame speed data and show that the data can be collapsed using the maximum stretched laminar flame speed, SL,max, rather than SL,0.
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Pugh, Daniel, Andrew Crayford, Philip Bowen, Tim O’Doherty, and Richard Marsh. "Variation in Laminar Burning Velocity and Markstein Length With Water Addition for Industrially Produced Syngases." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-25455.

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An outwardly propagating spherical flame has been used to characterise the influence of water addition on the combustion of variable steelworks gas compositions. Attention was given to the ratio of hydrogen and carbon monoxide within blast furnace gas, and the catalysing influence of water addition on the preponderant reaction kinetics. A nonlinear extrapolative technique was used to obtain values of laminar burning velocity and Markstein length for atmospheric combustion with air and change in equivalence ratio. Four disparate blast furnace gas mixtures were tested with increasing volumetric proportions of hydrogen in the range of one to seven percent, displacing other constituent fractions. A non-monotonic influence was observed, with propagation accelerated for compositions comprising smaller amounts of hydrogen, and the cooling impact of water addition shown to slow faster burning flames. Water addition was also shown to increase the effects of flame stretch on observed propagation rates, and the contrasting influences resulting from vapour fraction are discussed with respect to practical combustion instability, in addition to alternative synthesised fuels. Numerically modelled results were generated using the PREMIX coded CHEMKIN-PRO, and the performance of specified chemical reaction mechanisms evaluated in relation to the obtained experimental data.
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Pugh, Daniel, Tim O’Doherty, Anthony Griffiths, Philip Bowen, Andrew Crayford, Richard Marsh, Anthony Giles, and Andrew Hopkins. "Laminar Burning Velocity and Markstein Length Characterisation of Compositionally Dynamic Blast Furnace Gas." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-69667.

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Blast Furnace Gas is a poor quality process gas comprising proportions of CO, H2, CO2, and N2, with a low energy density typically in the order of 3 MJ·kg−1. Produced in large quantities as a by-product of blast furnace iron making, it is one of the process gases indigenous to integrated steelworks worldwide. The inherently dynamic nature of furnace operation causes compositional variation and therefore leads to fluctuation in the fuel characteristics, often dissuading engineers from fully utilising the gas in increasingly complex and efficient technologies such as gas turbines. Characterisation studies were undertaken in a new constant volume bomb to determine the sensitivity to change in laminar burning velocity and Markstein length experienced as a result of increasing the volumetric H2 fraction in the range of 1–7%. Experiments were performed by measuring outwardly propagating spherical flame evolution, recorded using a Schlieren flame visualisation technique for a range of equivalence ratios, and processed using nonlinear data analysis. The relative performance of the experimental technique was benchmarked against other works using well-investigated CH4 and yielded results in good agreement with published values. Peak laminar burning velocity was shown to increase by a factor of approximately 3.5 over the tested range, with H2 concentration and equivalence ratio shown to greatly influence the effect of flame stretch. Comparisons of results were also made with values obtained from different reaction mechanisms employed using the PREMIX code developed by Sandia National Laboratories.
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Reports on the topic "Length of stretch"

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Kodupuganti, Swapneel R., Sonu Mathew, and Srinivas S. Pulugurtha. Modeling Operational Performance of Urban Roads with Heterogeneous Traffic Conditions. Mineta Transportation Institute, January 2021. http://dx.doi.org/10.31979/mti.2021.1802.

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The rapid growth in population and related demand for travel during the past few decades has had a catalytic effect on traffic congestion, air quality, and safety in many urban areas. Transportation managers and planners have planned for new facilities to cater to the needs of users of alternative modes of transportation (e.g., public transportation, walking, and bicycling) over the next decade. However, there are no widely accepted methods, nor there is enough evidence to justify whether such plans are instrumental in improving mobility of the transportation system. Therefore, this project researches the operational performance of urban roads with heterogeneous traffic conditions to improve the mobility and reliability of people and goods. A 4-mile stretch of the Blue Line light rail transit (LRT) extension, which connects Old Concord Rd and the University of North Carolina at Charlotte’s main campus on N Tryon St in Charlotte, North Carolina, was considered for travel time reliability analysis. The influence of crosswalks, sidewalks, trails, greenways, on-street bicycle lanes, bus/LRT routes and stops/stations, and street network characteristics on travel time reliability were comprehensively considered from a multimodal perspective. Likewise, a 2.5-mile-long section of the Blue Line LRT extension, which connects University City Blvd and Mallard Creek Church Rd on N Tryon St in Charlotte, North Carolina, was considered for simulation-based operational analysis. Vissim traffic simulation software was used to compute and compare delay, queue length, and maximum queue length at nine intersections to evaluate the influence of vehicles, LRT, pedestrians, and bicyclists, individually and/or combined. The statistical significance of variations in travel time reliability were particularly less in the case of links on N Tryon St with the Blue Line LRT extension. However, a decrease in travel time reliability on some links was observed on the parallel route (I-85) and cross-streets. While a decrease in vehicle delay on northbound and southbound approaches of N Tryon St was observed in most cases after the LRT is in operation, the cross-streets of N Tryon St incurred a relatively higher increase in delay after the LRT is in operation. The current pedestrian and bicycling activity levels seemed insignificant to have an influence on vehicle delay at intersections. The methodological approaches from this research can be used to assess the performance of a transportation facility and identify remedial solutions from a multimodal perspective.
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