Force Based Canonical Approximation of Molecular Potentials: Average Force versus Pointwise Force

2020 ◽  
Vol 124 (8) ◽  
pp. 1648-1658
Author(s):  
Jay R. Walton ◽  
Luis A. Rivera-Rivera
Keyword(s):  
Average Force ◽  
Molecular Potentials

Stability and performance of the EnSite Precision cardiac mapping system for electrophysiology mapping and ablation procedures: results from the EnSite Precision observational study

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Lin ◽  
B Glover ◽  
J Colley ◽  
B Thibault ◽  
C.M Steinberg ◽  
...  
Keyword(s):  
Observational Study ◽  
Real World ◽  
Cardiac Electrophysiology ◽  
Median Number ◽  
System Stability ◽  
Cardiac Mapping ◽  
Average Force ◽  
Mapping System ◽  
Respiratory Change ◽  
Electrophysiology Mapping

Abstract Background The EnSite Precision™ Cardiac Mapping System is a catheter navigation and mapping system capable of displaying the three-dimensional (3D) position of conventional and sensor enabled electrophysiology catheters, as well as displaying cardiac electrical activity as waveform traces and dynamic 3-D maps of cardiac chambers. Objective The EnSite Precision™ Observational Study was designed to quantify and characterize the use of the EnSite Precision™ Cardiac Mapping System for mapping and ablation of cardiac arrhythmias in a real-world environment and to evaluate procedural and subsequent clinical outcomes. Methods 1065 patients were enrolled at 38 centers in the U.S. and Canada between 2017–2018. Eligible subjects were adults undergoing a cardiac electrophysiology mapping and radiofrequency ablation procedures using the EnSite Precision™ System. Results Of 989 patients who completed the protocol, a geometry was created in 936 (94.7%). Most initial maps were created using Automap (n=545, 67.0%) or a combination of Automap and manually mapping (n=151, 18.6%). Median time to create an initial map was 9.0 min (IQR 5.0–15.0), with a median number of used mapping points per minute of 92.7 (IQR 30.0–192.0). During ablation, AutoMark was used in 817 (82.6%) of procedures. The most frequent metrics for lesion color were Impedance Drop or Impedance Drop Percent (45.5% combined), time (23.9%) and average force (14.2%). At Canadian sites where LSI was an option, it was used as the color metric in 87 (45.8%) of cases (10.6% overall). The EnSite System was stable throughout 79.7% (n=788 of 989) of procedures. Factors affecting stability were respiratory change (n=88 of 989, 8.9%), patient movement (n=73, 7.4%), CS Positional Reference dislodgement (n=32, 3.2%), and cardioversion (n=19, 1.9%). Conscious sedation was used in 189 (19.1%) of patients. Acute success was reached based on the pre-defined endpoints for the procedure in 97.4% (n=963) of cases. Conclusion In a real-world study analysis, the EnSite Precision™ mapping system was associated with a high prevalence of acute procedural success, low mapping times, and high system stability. Funding Acknowledgement Type of funding source: None

Roller Cutter Forces

1970 ◽  
Vol 10 (01) ◽  
pp. 57-65 ◽  
Author(s):  
C.R. Peterson
Keyword(s):  
Normal Force ◽  
Penetration Rate ◽  
Rolling Force ◽  
Skew Angle ◽  
Average Force ◽  
Straight Line ◽  
Bearing Load ◽  
Boring Machines ◽  
Force Reduction ◽  
Cutter Head

Abstract An experimental technique is described in which three component forces are measured while a typical toothed cutter is rolled in a straight line over a rock sample. The technique includes the attainment of a steady state in which volume-averaged penetration is correlated with average force during penetration is correlated with average force during the removal of several layers from the rock surface. Simple rolling and skewed rolling forces are measured. The cutter was artificially dulled for some of the measurements. Surprisingly little variation in force requirement is noted. A qualitative explanation is suggestedThe normal force requirement is substantially reduced when the cutter is skewed. A theoretical description of the force reduction is presented, showing reasonable agreement with the observed behavior in terms of cutter radius, tooth width, penetration and skew angle. penetration and skew angle Introduction Toothed roller cutters have long been in use on tricone bits, and they are in common use on boring machines. Yet the designer of boring machines is still faced with a dearth of good design information on the performance of such cutters. For example, what are the relationships between thrust, power, and penetration rate? How are these relationships influenced by rock properties and cutter configuration?While the data presented here provide answers to more specific questions than those mentioned above, these data are necessary for arriving at solutions to the broader questions. This work is restricted to one tooth type, typical of the wedge-shaped steel teeth used on medium rock. A limited range of rock types was tested; this coupled with the extreme variation of rock drillability, renders the data of limited value in predicting penetration rate. But the designer must predicting penetration rate. But the designer must answer questions even more important than the prediction of absolute penetration rate. For example, prediction of absolute penetration rate. For example, the cutter normal force is usually known in terms of the thrust to be applied to the cutter head. What is the torque or power required to rotate the cutter head? For an answer, one need know only the ratio of normal force to the tangential or rolling force. This ratio may be estimated from the present data. Variation of this ratio is reasonably small from one rock to another so that, lacking more specific information, these data can provide at least rough design estimates for other rocks. Tricone bits for soft to medium rock usually are constructed with skewed cutter elements that provide a "gouging and scraping action". Whatever the explanation, skewed cutters do provide increased drilling rate or, for a given drilling rate, a decreased thrust requirement. To my knowledge, skewed cutter elements have not been used on boring machines. If they were, bearing load could be reduced at a given penetration rate, or, conversely, an increased penetration rate could be obtained at the same penetration rate could be obtained at the same bearing load. Of course, a side load is introduced to the cutter bearing and this must be provided for. As for the rolling force, the designer really needs only the ratio of side-to-normal load. The present data indicate that this ratio is quite independent of rock type. The magnitude of the force reduction to be expected with skewed cutters is also of interest. The present data indicate that substantial reductions might be expected. A simple analytical model predicts the observed reduction reasonably well on the basis of the limited data available. EXPERIMENTAL APPARATUS AND TECHNIQUES Forces produced by a single cutter wheel rolling in a straight line over the rock specimen were measured. This simple geometry is experimentally convenient and is thought to be reasonably representative of cutter conditions on a large boring machine. Fig 1 illustrates the "linear apparatus" on which the measurements were made. The cutter wheel was rotatably mounted in a heavy yoke. SPEJ P. 57

Electrostatic molecular potentials: Mulliken approximation

1975 ◽  
Vol 9 (2) ◽  
pp. 193-214 ◽  
Author(s):  
Ramón Carbó ◽  
Miguel Martin
Keyword(s):  
Molecular Potentials

scholarly journals Evaluation of Strength and Irradiated Movement Pattern Resulting from Trunk Motions of the Proprioceptive Neuromuscular Facilitation

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Luciana Bahia Gontijo ◽  
Polianna Delfino Pereira ◽  
Camila Danielle Cunha Neves ◽  
Ana Paula Santos ◽  
Dionis de Castro Dutra Machado ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Movement Pattern ◽  
Lower Limbs ◽  
Trunk Flexion ◽  
Average Force ◽  
Proprioceptive Neuromuscular Facilitation ◽  
Muscular Activation ◽  
Flexion And Extension ◽  
Regional Muscle ◽  
Dorsal Flexion

Introduction. The proprioceptive neuromuscular facilitation (PNF) is a physiotherapeutic concept based on muscle and joint proprioceptive stimulation. Among its principles, the irradiation is the reaction of the distinct regional muscle contractions to the position of the application of the motions.Objective. To investigate the presence of irradiated dorsiflexion and plantar flexion and the existing strength generated by them during application of PNF trunk motions.Methods. The study was conducted with 30 sedentary and female volunteers, the PNF motions of trunk flexion, and extension with the foot (right and left) positioned in a developed equipment coupled to the load cell, which measured the strength irradiated in Newton.Results. Most of the volunteers irradiated dorsal flexion in the performance of the flexion and plantar flexion during the extension motion, both presenting an average force of 8.942 N and 10.193 N, respectively.Conclusion. The distal irradiation in lower limbs became evident, reinforcing the therapeutic actions to the PNF indirect muscular activation.

Measurements of the nearly isotropic turbulence behind a uniform jet grid

1974 ◽  
Vol 62 (1) ◽  
pp. 115-143 ◽  
Author(s):  
Mohamed Gad-El-Hak ◽  
Stanley Corrsin
Keyword(s):  
Pressure Drop ◽  
Kinetic Energy ◽  
Static Pressure ◽  
Isotropic Turbulence ◽  
Decay Rates ◽  
Turbulence Energy ◽  
Turbulence Level ◽  
Average Force ◽  
General Behaviour ◽  
Decay Behaviour

Wind-tunnel turbulence behind a parallel-rod grid with jets evenly distributed along each rod is nearly isotropic. Homogeneity improvement over prior related experiments was attained by the use of controllable nozzles. Compared with the ‘passive’ case, the downwind-jet ‘active’ grid has a smaller static pressure drop across it and gives a smaller turbulence level at a prescribed distance from it, while the upwind-jet grid gives a larger static pressure drop and larger turbulence level. ‘Counterflow injection’ generates larger turbulence energy and larger scales, both events being evidently associated with instability of the jet system. This behaviour is much like that commonly observed behind passive grids of higher solidities.If the turbulent kinetic energy is approximated as an inverse power law in distance, the (positive) exponent decreases with increasing (downwind or upwind) jet strength, corresponding to slower absolute decay rates. No peculiar decay behaviour occurs when the jet grid is ‘self-propelled’ (zero net average force), or when the static pressure drop across it is zero.The injection does not change the general behaviour of the energy spectra, although the absolute spectra change inasmuch as the turbulence kinetic energy changes.

KINETIC INDICATORS OF TRAINING METHODS AND SELECTION OF YOUNG ROWERS

sportlogia ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. 13-24
Author(s):  
Željko M. Rajković ◽  
◽  
Darko N. Mitrović ◽  
Vladimir K. Miletić ◽  
Petar M. Spaić ◽  
...  
Keyword(s):  
Average Power ◽  
The Other ◽  
Training Methods ◽  
Average Force ◽  
Other Hand ◽  
The World ◽  
Strict Selection ◽  
Selection Of

Modern diagnostics in rowing enables more and more possibilities for recording, and comparing numerous stroke variables. At the same time, many coaches fall into the trap of strict respect for the prescribed norms, ratios, and temporarily results, which the athlete must achieve if he wants to stay in the world of competitive rowing. On the example of the comparison of rowing schools RC "Danubius" and RC "Partizan", descriptive indicators are on the side of RC "Danubius" at a time of 2000m, average force and average power. No significant differences were found in average force (sig = 0,167) between rowers of RC "Danubius" and RC "Partizan", while statistically significant differences were recorded in time at 2000m (sig = 0,036) and power (sig = 0,02) in favor of rowers of RC “Danubius”. On the other hand, a higher correlation of average force (-0,955) and power (-0,928) with time on 2000m was achieved by RC "Partizan" than RC "Danubius" (-0,931) and (-0,896). The correlation between the average force, and the average power within one team shows a higher correlation for RC “Partizan" (0,95) compared to RC "Danubius" (0,755). The obtained results are not enough for single rower or crew elimination from competition to recreational section in the process of too frequent and strict selection of rowers, considering different possible ways of building rowing techniques and numerous parasitic factors that may affect measured variables, specialy at the age under 14 and novice rowers in general.

Average force obtained from the impulse or from the mechanical work?

2021 ◽  
Vol 56 (5) ◽  
pp. 053006
Author(s):  
F Ribas ◽  
J A Espinosa ◽  
F Lusquiños
Keyword(s):  
Mechanical Work ◽  
Average Force

The effects of pH on force and stiffness development in mouse muscles

1987 ◽  
Vol 65 (8) ◽  
pp. 1798-1801 ◽  
Author(s):  
J. M. Renaud ◽  
R. B. Stein ◽  
T. Gordon
Keyword(s):  
High Frequency ◽  
Small Amplitude ◽  
Force Production ◽  
Muscle Length ◽  
Low Ph ◽  
Muscle Stiffness ◽  
Average Force ◽  
Cross Bridge ◽  
Effects Of Ph ◽  
Cross Bridges

Changes in force and stiffness during contractions of mouse extensor digitorum longus and soleus muscles were measured over a range of extracellular pH from 6.4 to 7.4. Muscle stiffness was measured using small amplitude (<0.1% of muscle length), high frequency (1.5 kHz) oscillations in length. Twitch force was not significantly affected by changes in pH, but the peak force during repetitive stimulation (2, 3, and 20 pulses) was decreased significantly as the pH was reduced. Changes in muscle stiffness with pH were in the same direction, but smaller in extent. If the number of attached cross-bridges in the muscle can be determined from the measurement of small amplitude, high frequency muscle stiffness, then these findings suggest that (a) the number of cross-bridges between thick and thin filaments declines in low pH and (b) the average force per cross-bridge also declines in low pH. The decline in force per cross-bridge could arise from a reduction in the ability of cross-bridges to generate force during their state of active force production and (or) in an increased percentage of bonds in a low force, "rigor" state.

Constructing global functional maps between molecular potentials and quantum observables

2001 ◽  
Vol 114 (21) ◽  
pp. 9325-9336 ◽  
Author(s):  
J. M. Geremia ◽  
Herschel Rabitz ◽  
Carey Rosenthal
Keyword(s):  
Molecular Potentials ◽  
Quantum Observables
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