scholarly journals Aplicação dos métodos de cálculo aproximado e de Gibbs na determinação das cargas atuantes no bombeio mecânico com hastes

2021 ◽  
Vol 8 (1) ◽  
pp. 67-85
Author(s):  
Camylla Moreira de Oliveira ◽  
Oldrich Joel Romero
Keyword(s):  
Peak Torque ◽  
Polished Rod

O bombeio mecânico é o método de elevação artificial mais utilizado no mundo e a determinação de seus parâmetros operacionais é de extrema importância para a otimização de seu desempenho. O controle das cargas máximas e mínimas na haste pode garantir um tempo de vida útil maior para as hastes e para todo o sistema de bombeio mecânico (Pons, 2014). A simulação do comportamento da coluna de hastes é o método mais adequado para a descrição deste sistema. Neste trabalho são utilizados o método do cálculo aproximado, e o método de Gibbs para o cálculo dos parâmetros operacionais PPRL – Peak Polished Rod Load, MPRL – Minimum Polished Rod Load e PT – Peak Torque. O método de Gibbs foi aplicado através do software SROD® e os dados reais para o estudo foram obtidos do banco de dados da Petrobras retirados do software TWM® (Total Well Management). É realizada a comparação dos resultados da simulação com duas pressões de sucção diferentes fornecidas pelo software TWM, a pressão de sucção da bomba calculada a partir do teste acústico e a pressão de sucção da bomba calculada a partir da carta dinamométrica. Os resultados mostram que para o método do cálculo aproximado a pressão de sucção da bomba calculada a partir do teste acústico é a mais adequada a ser utilizada, e para a modelagem dinâmica via SROD® a pressão de sucção mais adequada é aquela proveniente da análise da carta dinamométrica.

Effect of Al2O3 and SiO2 Metal Oxide Nanoparticles Blended with POME on Combustion, Performance and Emissions Characteristics of a Diesel Engine

2019 ◽  
Vol 16 (3) ◽  
pp. 6859-6873 ◽  
Author(s):  
M. A. Adzmi ◽  
A. Abdullah ◽  
Z. Abdullah ◽  
A. G. Mrwan
Keyword(s):  
Diesel Engine ◽  
Metal Oxide Nanoparticles ◽  
Peak Torque ◽  
Combustion Characteristic ◽  
Maximum Pressure ◽  
Single Cylinder ◽  
Engine Testing ◽  
Co Addition ◽  
Carbon Dioxide Co2 ◽  
Test Fuel

Evaluation of combustion characteristic, engine performances and exhaust emissions of nanoparticles blended in palm oil methyl ester (POME) was conducted in this experiment using a single-cylinder diesel engine. Nanoparticles used was aluminium oxide (Al2O3) and silicon dioxide (SiO2) with a portion of 50 ppm and 100 ppm. SiO2 and Al2O3 were blended in POME and labelled as PS50, PS100 and PA50, PA100, respectively. The data results for PS and PA fuel were compared to POME test fuel. Single cylinder diesel engine YANMAR TF120M attached with DEWESoft data acquisition module (DAQ) model SIRIUSi-HS was used in this experiment. Various engine loads of zero, 7 N.m, 14 Nm, 21 N.m and 28 N.m at a constant engine speed of 1800 rpm were applied during engine testing. Results for each fuel were obtained by calculating the average three times repetition of engine testing. Findings show that the highest maximum pressure of nanoparticles fuel increase by 16.3% compared to POME test fuel. Other than that, the engine peak torque and engine power show a significant increase by 43% and 44%, respectively, recorded during the PS50 fuel test. Meanwhile, emissions of nanoparticles fuel show a large decrease by 10% of oxide of nitrogen (NOx), 6.3% reduction of carbon dioxide (CO2) and a slight decrease of 0.02% on carbon monoxide (CO). Addition of nanoparticles in biodiesel show positive improvements when used in diesel engines and further details were discussed.  

Modeling of Dynamic Loads on the Polished Rod of Pumping Unit in Case of Mulfunction of Rod Pump Operating

2014 ◽  
Vol 10 ◽  
pp. 95-101
Author(s):  
A.S. Topolnikov
Keyword(s):  
Multiphase Flow ◽  
Satisfactory Agreement ◽  
Model Simulation ◽  
Theoretical Modeling ◽  
Dynamic Loads ◽  
Plunger Pump ◽  
Proposed Model ◽  
Pumping Unit ◽  
Polished Rod

The paper presents the results of theoretical modeling of joined movement of pump rods and plunger pump and multiphase flow in a well for determination of dynamic loads on the polished rod of pumping unit. The specificity of the proposed model is the possibility of taking into account for complications in rod pump operating, such as leakage in valve steam, presence of gas and emulsion, incorrect fitting of plunger inside the cylinder pump. The satisfactory agreement of results of the model simulation with filed measurements are obtained.

scholarly journals 602 THE EFFECT OF BILATERAL ISOKINETIC KNEE EXTENSION/FLEXION ON JOINT ANGLE AT PEAK TORQUE

1993 ◽  
Vol 25 (Supplement) ◽  
pp. S108 ◽  
Author(s):  
J. R. Bryant ◽  
L. E. Brown ◽  
M. Whitehurst
Keyword(s):  
Joint Angle ◽  
Peak Torque ◽  
Knee Extension

Muscle Strength Deficit though Intact Proprioception after Lateral Ankle Sprain without Persistent Instability

2021 ◽  
Author(s):  
Adel M. Madkhali ◽  
Shibili Nuhmani
Keyword(s):  
Ankle Sprain ◽  
Peak Torque ◽  
Position Sense ◽  
Joint Position Sense ◽  
Joint Position ◽  
Lateral Ankle Sprain ◽  
Lateral Ankle ◽  
Cohen’S D ◽  
History Of ◽  
Cohen's D

Abstract Background Lateral ankle sprain is one of the most common injuries in competitive sports. Previous studies which investigated muscle strength and proprioception (joint position sense) focused on subjects who sustained ankle sprain with instability. It is also important to investigate strength deficits and proprioception in subjects with a history of ankle sprain without instability. Therefore the aim of the study is to investigate proprioception and muscle strength deficits in athletes with lateral ankle sprain. Methods Twenty-four male athletes with a history of lateral ankle sprain and 24 age-matched controls (mean age of 22.42±4.13 years, mean height of 173±5.73 cm, and mean weight of 71.20±7.55 Kg) participated in this cross-sectional study. Peak torque and peak torque ratio at speeds of 30 and 120°/s for concentric and eccentric ankle inversion/eversion were evaluated using an isokinetic dynamometer. The joint position sense of the ankle joint was evaluated using an active angle reproduction test. Result Peak torque produced was significantly less in subjects with history of ankle sprain in concentric inversion 30°/s(t(47)=4.11; p=0.000, Cohen’s d=1.29), concentric inversion 120°/s (t(47)=3.01; p=0.006, Cohen’s d=1.13), concentric eversion 30°/s (t(47)=3.85; p=0.001, Cohen’s d=1.24) and concentric eversion 120°/s (t(47)=3.15; p=0.005, Cohen’s d=1.09). At the same time there was no significant difference observed in eccentric eversion peak torque in both speed (eccentric eversion 30°/s p=0.079; eccentric eversion 120°/s p=0.867) between experimental and control group. No significant difference was found in the joint position sense in the maximal active inversion −5° position (p=0.312) and the 15° inversion position (P=0.386) between both group. Conclusion The study’s results reported a significantly less peak torque of invertors and evertors during concentric movements in athletes with history of ankle sprain. At the same time, no significant difference reported in the evertor/invertor peak torque ratio, and active joint position sense between the 2 groups.

scholarly journals Reliability of a New Portable Dynamometer for Assessing Hip and Lower Limb Strength

2021 ◽  
Vol 11 (8) ◽  
pp. 3391
Author(s):  
Jan Marušič ◽  
Goran Marković ◽  
Nejc Šarabon
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Peak Torque ◽  
Knee Extension ◽  
Lower Limb Muscles ◽  
Lower Limb Strength ◽  
Flexion Extension ◽  
Strength Tests ◽  
Hip Abduction ◽  
Maximal Peak

The purpose of this study was to evaluate intra- and inter-session reliability of the new, portable, and externally fixated dynamometer called MuscleBoard® for assessing the strength of hip and lower limb muscles. Hip abduction, adduction, flexion, extension, internal and external rotation, knee extension, ankle plantarflexion, and Nordic hamstring exercise strength were measured in three sessions (three sets of three repetitions for each test) on 24 healthy and recreationally active participants. Average and maximal value of normalized peak torque (Nm/kg) from three repetitions in each set and agonist:antagonist ratios (%) were statistically analyzed; the coefficient of variation and intra-class correlation coefficient (ICC2,k) were calculated to assess absolute and relative reliability, respectively. Overall, the results display high to excellent intra- and inter-session reliability with low to acceptable within-individual variation for average and maximal peak torques in all bilateral strength tests, while the reliability of unilateral strength tests was moderate to good. Our findings indicate that using the MuscleBoard® dynamometer can be a reliable device for assessing and monitoring bilateral and certain unilateral hip and lower limb muscle strength, while some unilateral strength tests require some refinement and more extensive familiarization.

scholarly journals Cancer-Related Fatigue and Muscle Quality in Hodgkin’s Lymphoma Survivors

2017 ◽  
Vol 17 (2) ◽  
pp. 299-305 ◽  
Author(s):  
Filipe Dinato de Lima ◽  
Martim Bottaro ◽  
Ritielli de Oliveira Valeriano ◽  
Lorena Cruz ◽  
Claudio L. Battaglini ◽  
...  
Keyword(s):  
Physical Activity ◽  
Body Composition ◽  
Hodgkin’S Lymphoma ◽  
Muscle Thickness ◽  
Peak Torque ◽  
Hodgkin's Lymphoma ◽  
Muscle Quality ◽  
Activity Levels ◽  
Physical Activity Levels ◽  
Lymphoma Survivors

The purpose of this study was to compare fatigue, strength, body composition, muscle thickness, and muscle quality between Hodgkin’s lymphoma survivors (HLS) and apparently healthy subjects matched by age, gender, and physical activity levels (CON). Twelve HLS (32.16 ± 8.06) and 36 CON (32.42 ± 7.64) were enrolled in the study. Fatigue was assessed using the 20-item Multidimensional Fatigue Inventory, muscle strength using an isokinetic dynamometer, body composition using dual-energy X-ray absorptiometry, and thickness and muscle quality using B-mode ultrasound. Differences between HLS and CON were analyzed using independent samples t tests. No significant differences were observed between groups for any demographic characteristics: age ( P = .922), weight ( P = .943), height ( P = .511), body mass index ( P = .796), fat mass ( P = .688), fat-free mass ( P = .520), and percent body fat ( P = .446). No significant differences were observed for strength (peak torque; P = .552), relative peak torque ( P = .200), muscle thickness ( P > .05) and muscle quality ( P > .05). However, self-perceived fatigue was significantly higher in HLS than in CON ( P = .009). It appears that when HLS are matched by age and physical activity levels to CON, no significant difference in body composition, muscle thickness, muscle quality, or strength is observed. Self-perceived fatigue, as predicted, is higher in HLS, which may have implications and should be considered when prescribing exercise training to this cancer population.

scholarly journals STRONGER THAN EVER! ADOLESCENT ATHLETES SHOW STRENGTH GAINS WITHIN THE UNINJURED LEG AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0005
Author(s):  
Elliot Greenberg ◽  
Joshua Bram ◽  
Theodore Ganley
Keyword(s):  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Reconstruction ◽  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Cohort Analysis ◽  
Peak Torque ◽  
Quadriceps Strength ◽  
Strength Assessment ◽  
Cruciate Ligament Reconstruction ◽  
Anterior Cruciate

Background: The restoration of quadriceps strength after anterior cruciate ligament reconstruction (ACLR) is critical to restore optimal patient function and reduce the incidence of secondary ACL injury. Strength is typically quantified during return to sport assessments, by comparing the strength in the involved limb to that of the uninvolved limb. A limb symmetry index (LSI) is calculated and used to determine if any residual strength deficits persist. Recent evidence demonstrates that the uninvolved limb may lose strength during ACLR recovery and suggests that pre-operative uninvolved limb strength values may offer a better representation and more stringent indicator of strength recovery after ACLR. However, this body of literature is limited and no studies have specifically evaluated this occurrence within youth athletes. Purpose: To evaluate the change in strength in the uninvolved limb from pre-operative to 6 months post-ACLR, and assess the effect of pre-operative strength comparison on 6-month post-op LSI. Methods: A retrospective cohort analysis of pediatric patients (≤18 years) undergoing primary ACLR from 1/2018-1/2020 without concomitant multi-ligamentous reconstruction was conducted. Isokinetic peak torque values for the uninvolved and involved quadriceps were extracted at pre-operative (uninvolved only) and 6 months post-operative. Strength changes were analyzed using paired-samples t-test. Results: Complete data was available for a total of 17 subjects (mean age 15.1±1.7, 53% female). Pre-operative strength assessment was performed a mean of 11.5 days (range 1-26) prior to surgery. The mean 6-month post-operative assessment occurred at 177 days (range 127-246). The uninvolved limb was significantly stronger (p<0.001) at 6 months compared to preoperatively, with a mean improvement of 12.1ft/lbs (95%CI 18.3 – 7.2) with a change from 82.4ft/lbs to 95.1 ft/lbs. The LSI was calculated using both pre-operative and 6-month post-operative uninvolved limb values and demonstrated substantially lower LSI values when using concurrent 6-month data (LSIpre 91.3% vs LSI6M 76.9%). Conclusions: Among this sample, the uninvolved limb got stronger during post-ACLR recovery and comparison to concurrently assessed strength values led to a more stringent determination of LSI. Differences in rehabilitation programming, adolescent physiology, and pre-injury training patterns may explain why these results differ than those found in older cohorts.

scholarly journals Test-Retest Reliability of Isokinetic Knee Strength Measurements in Type 2 Diabetes Mellitus Patients

2021 ◽  
Vol 13 (3) ◽  
pp. 1343
Author(s):  
José Carmelo Adsuar ◽  
Jose Parraca ◽  
Armando Raimundo ◽  
Miguel Angel Garcia-Gordillo ◽  
Patricia Polero ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Peak Torque ◽  
Total Sample ◽  
Good For ◽  
The Right ◽  
Test Retest Reliability ◽  
Standard Error Of Measurement

Background: Reliability studies are used to verify the evaluation accuracy of a given device. Strength is an important factor for the development of daily activities and its correct management is fundamental. The objective of this study was to examine the reliability of a concentric strength test in people with type 2 diabetes mellitus (T2DM). Methods: Twenty-seven individuals with T2DM performed three repetitions of extension-flexion in concentric-concentric action at 60°/s, for both legs, using an isokinetic dynamometer. For the reliability analysis, we performed an intra-session test retest. Results: The total sample and men sub-group intra-class correlation coefficient (ICC) values were excellent for peak torque and work. In the women sub-group, ICC values were excellent for extensors in both peak torque and work; however, concerning flexor, the ICC values were good for peak torque while, for work, they were good for the right leg and moderate for the left leg. Standard error of measurement (SEM) percentage oscillated from 3.85% to 6.80%, with the smallest real difference (SRD) percentage being from 10.66% to 18.86% for peak torque. Furthermore, the SEM (%) was around 5.5% and SRD (%) was around 15% for work. Conclusions: The isokinetic dynamometry had “good” to “excellent” relative reliability for peak torque (0.862–0.983) and work (0.744–0.982) of extension-flexion in concentric-concentric action at 60°/s. In addition, our study showed that, in general, an SRD < 20% could indicate a true change in strength regarding this protocol in T2DM.

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