scholarly journals Analytical solution of the problem of dynamic synthesis of a six-link straight-line converting mechanism of the sucker-rod pumping drive

2021 ◽  
Vol 6 (7 (114)) ◽  
Author(s):  
Ayaulym Rakhmatulina ◽  
Nurbibi Imanbayeva ◽  
Sayat Ibrayev ◽  
Assemgul Uderbayeva ◽  
Aiman Nurmaganbetova
Keyword(s):  
Analytical Solution ◽  
Correction Factor ◽  
Unknown Parameter ◽  
Dynamic Balancing ◽  
Maximum Torque ◽  
The Third ◽  
Dynamic Synthesis ◽  
Sucker Rod ◽  
Optimal Dynamic ◽  
Two Peaks

The paper presents an analytical solution to the problem of optimal dynamic balancing of the six-link converting mechanism of the sucker-rod pumping unit. This problem is solved numerically using a computer model of dynamics, namely by selecting the value of the correction factor k. Here we will consider an analytical method for solving this problem, that is, we find the location of the counterweight on the third link of the six-link converting mechanism for balancing. To solve the problem, we use the principle of possible displacement and write an equation where we express the torque through the unknown parameter of the counterweight. Further, such a value of the unknown parameter is found, at which the minimum of the root-mean-square value of torque M is reached. From the condition of the minimum of the function, we obtain an equation for determining the location of the counterweight. Thus, we obtain an analytical solution to the problem of optimal dynamic balancing of the six-link converting mechanism of the sucker-rod pumping drive in various settings.  According to the results, it was found that with the combined balancing method, the value of the maximum torque M and the value of the maximum power are reduced by 20 % than when the counterweight is placed on the third link of the converting mechanism, as well as when the value of the maximum torque is determined through the correction factor k. In practice, balancing is carried out empirically by comparing two peaks of torque M on the crank shaft per cycle of the mechanism movement. Solving the analytical problem, we determine the exact location of the counterweight.

scholarly journals Subcellular structure of bovine thyroid gland. The localization of the peroxidase activity in bovine thyroid

1978 ◽  
Vol 174 (3) ◽  
pp. 939-949 ◽  
Author(s):  
M J S De Wolf ◽  
A R Lagrou ◽  
H J J Hilderson
Keyword(s):  
Peroxidase Activity ◽  
Buoyant Density ◽  
Thyroid Tissue ◽  
Guaiacol Peroxidase ◽  
Subcellular Structure ◽  
The Third ◽  
Bovine Thyroid ◽  
Two Peaks ◽  
Second Peak ◽  
Membranous Material

1. After differential pelleting of bovine thyroid tissue the highest relative specific activities for plasma membrane markers are found in the L fraction whereas those for peroxidase activities (p-phenylenediamine, guaiacol and 3,3′-diaminobenizidine tetrachloride peroxidases) are found in the M fraction. 2. When M + L fractions were subjected to buoyant-density equilibration in a HS zonal rotor all peroxidases show different profiles. The guaiacol peroxidase activity always follows the distribution of glucose 6-phosphatase. 3. When a Sb fraction is subjected to Sepharose 2B chromatography three major peaks are obtained. The first, eluted at the void volume, consists of membranous material and contains most of the guaiacol peroxidase activity. Most of the protein (probably thyroglobulin) is eluted with the second peak. Solubilized enzymes are recovered in the third peak. 4. p-Phenylenediamine peroxidase activity penetrates into the gel on polyacrylamidegel electrophoresis, whereas guaiacol peroxidase activity remains at the sample zone. 5. DEAE-Sephadex A-50 chromatography resolves the peroxidase activities into two peaks, displaying different relative amounts of the different enzymic activities in each peak. 6. The peroxidase activities may be due to the presence of different proteins. A localization of guaiacol peroxidase in rough-endoplasmic-reticulum membranes (or in membranes related to them) seems very likely.

Parametric estimators for stationary time series with missing observations

1981 ◽  
Vol 13 (01) ◽  
pp. 129-146 ◽  
Author(s):  
W. Dunsmuir ◽  
P. M. Robinson
Keyword(s):  
Unknown Parameter ◽  
Strong Consistency ◽  
Moving Average ◽  
Stationary Time Series ◽  
Autoregressive Moving Average ◽  
Missing Observations ◽  
Parameter Vector ◽  
Moving Average Process ◽  
The Third ◽  
Unknown Parameter Vector

Three related estimators are considered for the parametrized spectral density of a discrete-time process X(n), n = 1, 2, · · ·, when observations are not available for all the values n = 1(1)N. Each of the estimators is obtained by maximizing a frequency domain approximation to a Gaussian likelihood, although they do not appear to be the most efficient estimators available because they do not fully utilize the information in the process a(n) which determines whether X(n) is observed or missed. One estimator, called M3, assumes that the second-order properties of a(n) are known; another, M2, lets these be known only up to an unknown parameter vector; the third, M1, requires no model for a(n). Under representative sets of conditions, which allow for both deterministic and stochastic a(n), the strong consistency and asymptotic normality of M1, M2, and M3 are established. The conditions needed for consistency when X(n) is an autoregressive moving-average process are discussed in more detail. It is also shown that in general M1 and M3 are equally efficient asymptotically and M2 is never more efficient, and may be less efficient, than M1 and M3.

An analytical solution to separate P‐waves and S‐waves in VSP wavefields

Geophysics ◽  
1995 ◽  
Vol 60 (4) ◽  
pp. 955-967 ◽  
Author(s):  
Hiroshi Amano
Keyword(s):  
Analytical Solution ◽  
Formal Solution ◽  
Seismic Profile ◽  
Synthetic Seismograms ◽  
Third Order ◽  
P Waves ◽  
Practical Applications ◽  
S Waves ◽  
The Third ◽  
Z Domain

An analytical solution to separate P‐waves and S‐waves in vertical seismic profile (VSP) wavefields is derived using combinations of certain terms of the formal solution for forward VSP modeling. Some practical applications of this method to synthetic seismograms and field data are investigated and evaluated. Little wave distortion is recognized, and the weak wavefield masked by dominant wavetrains can be extracted with this method. The decomposed wavefield is expressed in the frequency‐depth (f-z) domain as a linear combination of up to the third‐order differential of traces, which is approximated by trace differences in the practical separation process. In general, five traces with single‐component data are required in this process, but the same process is implemented with only three traces in the acoustic case. Two‐trace extrapolation is applied to each edge of the data gather to enhance the accuracy of trace difference. Since the formulas are developed in the f-z domain, the influence of anelasticity can be taken into account, and the calculation is carried out fast enough with the benefit of the fast Fourier transform (FFT).

Heat Transfer Measurements of Oblong Pins

2014 ◽  
Author(s):  
Kathryn L. Kirsch ◽  
Karen A. Thole
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Flow Direction ◽  
Effective Means ◽  
Transfer Enhancement ◽  
Pin Fin ◽  
The Third ◽  
Pin Fins ◽  
Two Peaks ◽  
Pin Fin Arrays

Pin fin arrays are employed as an effective means for heat transfer enhancement in the internal passages of a gas turbine blade, specifically in the blade’s trailing edge. Various shapes of the pin itself have been used in such arrays. In this study, oblong pin fins are investigated whereby their long axis is perpendicular to the flow direction. Heat transfer measurements were taken at the pin mid-span with unheated endwalls to isolate the pin heat transfer. Results show important differences in the heat transfer patterns between a pin in the first row and a pin in the third row. In the third row, wider spanwise spacing allows for two peaks in heat transfer over the pin surface. Additionally, closer streamwise spacing leads to consistently higher heat transfer for the same spanwise spacing. Due to the blunt orientation of the pins, the peak in heat transfer occurs off the stagnation point.

Growth and development of larvae and adults of Tipula sacra Alexander (Insecta: Diptera) in a series of abandoned beaver ponds

1976 ◽  
Vol 54 (2) ◽  
pp. 266-284 ◽  
Author(s):  
G. Pritchard
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Growth And Development ◽  
Adult Emergence ◽  
Head Capsule ◽  
Fourth Instar ◽  
Beaver Ponds ◽  
The Third ◽  
First Instar ◽  
Two Peaks

Collections of all stages of the crane fly, Tipula sacra have been made over a period of years from a series of abandoned beaver ponds in the Kananaskis Valley, Alberta. The growth of larvae was followed by head-capsule measurements and weights. Eggs hatch within a month; first-instar larvae grow rapidly and enter the second instar after a few weeks. The second instar may last for 3 months and the third instar usually lasts for 6 months, including the first winter. Most larvae spend almost a full year in the fourth instar and overwinter for a second time. However, there was much variation in growth rate within the population. Adult emergence curves were consistent in form in 4 years. Each spanned a period of just over 2 months, although individual adults lived for only a few days. These curves snowed two peaks, the second of which contained 15–20% of the year's emergents. These two groups may represent different cohorts that have grown at different rates, suggesting that the life history may be semivoltine or univoltine. The sex ratio changes from about 1:1 in the third instar to 2:1 in favor of males in the late fourth instar, pupa, and adult.

scholarly journals Optimal dynamic balancing of a hybrid serial-parallel robotic manipulator through bio-inspired computing

2021 ◽  
Author(s):  
Ricardo Mejia-Rodriguez ◽  
Miguel Gabriel Villarreal-Cervantes ◽  
Josue Nathan Martinez-Castelan ◽  
Jose Saul Munoz-Reina ◽  
Silva-Garcia
Keyword(s):  
Robotic Manipulator ◽  
Dynamic Balancing ◽  
Optimal Dynamic

scholarly journals Analytical solution of a class of nonlinear differential equations of the third order in the complex area

2021 ◽  
pp. 75-84
Author(s):  
Виктор Николаевич Орлов ◽  
Людмила Витальевна Мустафина
Keyword(s):  
Analytical Solution ◽  
Differential Equations ◽  
A Priori Estimates ◽  
Nonlinear Differential Equations ◽  
A Priori ◽  
A Priori Estimate ◽  
Third Order ◽  
The Third ◽  
Change Of Variables ◽  
Priori Estimates

В работе приводится доказательство теоремы существования и единственности аналитического решения класса нелинейных дифференциальных уравнений третьего порядка, правая часть которого представлена полиномом шестой степени, в комплексной области. Расширен класс рассматриваемых уравнений за счет новой замены переменных. Получена априорная оценка аналитического приближенного решения. Представлен вариант численного эксперимента оптимизации априорных оценок с помощью апостериорных. The article presents a proof of the theorem of the existence and uniqueness of the analytical solution of the class of nonlinear differential equations of the third order, with a polynomial right-hand side of the sixth degree, in the complex domain. The class of the considered equations has been extended by means of a new change of variables. An a priori estimate of the analytical approximate solution is obtained. A variant of the numerical experiment of optimizing a priori estimates using a posteriori estimates is presented.

Novel Approach of Sucker Rod Pump Unit Balance Determination and Monitoring

2021 ◽  
Author(s):  
Yuzar Aryadi ◽  
Azis Hidayat ◽  
Hilman Lazuardi ◽  
Syahroni Isnanto ◽  
Bonni Ariwibowo ◽  
...  
Keyword(s):  
Correction Factor ◽  
Electrical Parameter ◽  
Standard Procedure ◽  
Parameter Distribution ◽  
Well Performance ◽  
Optimization Software ◽  
Sucker Rod ◽  
Sucker Rod Pump ◽  
Pumping Unit ◽  
New Equation

Abstract SCADA optimization platform is implemented to monitor and evaluate well performance. For Sucker Rod Pump, SCADA Optimization Software can be used to monitor the unit balance and gearbox torque. In some ways, not all required well configuration data for SCADA Optimization Software to do a calculation of counterbalance torque (CBT) for pumping unit balance and gearbox torque evaluation are available. Standard field Counterbalance Effect (CBE) measurement might be performed to calculate the CBT value. However, this standard procedure is limited to well that run on balance condition. For well with unbalance condition, the measured CBE needs to be adjusted by a correction factor which the equation will be presented in this paper. The corrected CBE value from the new equation is then inputted to the SCADA Optimization software to perform day-to-day real-time monitoring of pumping unit balance and gearbox torque. Derivation of the CBE correction factor equation is presented. Validation upon this new equation is performed by comparing the result with electrical measurement on the pumping unit motor. Using the calculated CBT from the new equation, SCADA Optimization Software performs gearbox torque and pumping unit balance analysis based on every collected dynamometer card. Calculated CBT from the new equation provided results in gearbox torque distribution pattern that match with measured electrical parameter distribution along the stroke. This CBT value assists SCADA optimization software to calculate pumping unit balance and gearbox torque. Alarm in the SCADA optimization software that coming from an anomaly on pumping unit balance and gearbox torque help operator to do preventive maintenance so that pumping unit component especially the gearbox could have longer run life.

Some Useful Approximations for the Availability Function

2015 ◽  
Vol 22 (02) ◽  
pp. 1550008 ◽  
Author(s):  
Viswanathan Arunachalam ◽  
Alvaro Calvache ◽  
Ayşe Tansu
Keyword(s):  
Communication Network ◽  
Integral Equation ◽  
Analytical Solution ◽  
Reliability Analysis ◽  
Test Cases ◽  
Channel Access ◽  
The Third ◽  
Access Scheme ◽  
Opportunistic Channel Access ◽  
Functional Forms

Availability function which forms an important part of reliability analysis is expressed in terms of an integral equation. The analytical solution of such an equation is possible only in very simple cases and hence approximations are the only tools available; very few such approximations are available in the literature. This paper proposes three useful approximations, two of which are based only on the first few moments of the underlying distributions and do not require their functional forms. The third approximation uses the Riemannian sum to approximate the integral equation. Numerical illustrations based on test cases are provided to show the efficacy of the approximations. As an application, the problem of an opportunistic channel access scheme in a communication network is used to test the approximations.

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