scholarly journals Research on Multi-Stage Composite Loading Process Control Method for Roller Staking of Self-Lubricating Spherical Plain Bearings

2021 ◽  
Vol 11 (23) ◽  
pp. 11127
Author(s):  
Qiang Wang ◽  
Jigang Chen ◽  
Haili Zhou ◽  
Xiaokang Wang ◽  
Zhanqi Hu
Keyword(s):  
Process Control ◽  
Control Method ◽  
Groove Depth ◽  
Material Damage ◽  
Technical Standards ◽  
Deformation Degree ◽  
Loading Process ◽  
Time Control ◽  
Multi Stage

The staking quality of Self-lubricating Spherical Plain Bearings (SSPBs) directly affects the safety of aircraft and the service life of bearings. Reliable loading process control methods and precise process parameter indexes will come into the creation of efficacious staking quality. Therefore, this paper aims to analyze the mechanical state of the roller staking process and give a load control method and corresponding parameter indexes for the high-quality roller staking process. First, based on the analysis of quality inspection requirements, five states of the deformation degree of the flanging lip of the V groove during the roller staking process were proposed, and their relationship with the requirements was studied. Then, the mechanical states corresponding to the five deformation states of the flanging lip deformation were obtained by numerical simulation, and the feeding displacement was determined. Meanwhile, a Multi-Stage Composite Loading (MSCL) process control method was first proposed to control the material damage of the flanging lip, i.e., the rotate speed of the roller tool was constant during the roller staking process, and the displacement–time control was adopted first; when the staking load reaches a staking value, the force–time control was used to make the staking quality meet the requirements. Finally, the staking quality of the MSCL method was verified though the test. The research shows that the feeding displacement needs to be added to the requirements, and the recommended value is 0.5–0.6 times of the V groove depth. A good surface quality and non-material-damage of the flanging lip is more likely to be obtained by the MSCL process control method. The research reveals the formation mechanism of process deformation, and gives more precise process control indexes. At the same time, it provides a theoretical reference for more reliable technical standards.

METHODS ASSESSMENT QUALITY OF ACCOUNTING REPORTING AND MODELS OF THEIR MEASUREMENT

2020 ◽  
Vol 3 (3) ◽  
pp. 95-99
Author(s):  
E. H. ABU ◽  
Keyword(s):  
Internal Control ◽  
Stock Prices ◽  
Control Method ◽  
Financial Statements ◽  
Accounting Conservatism ◽  
Standardized Assessment ◽  
Accrual Quality ◽  
Indirect Measures

The article explores individual approaches used to measure and evaluate the quality of financial state-ments: standardized assessment, accrual-based models (accrual quality), Beneise models (M-Score), in-dexes - the internal control method and the degree of accounting conservatism. The reason for the great dependence on the use of indirect measures (proxies for the quality of financial statements or stock prices) is that some of the qualities of financial statements are unobservable.

Quality Improvement of the DNA extracted by boiling method in Gram negative bacteria

2017 ◽  
Vol 6 (04) ◽  
pp. 5347 ◽  
Author(s):  
Omar B. Ahmed* ◽  
Anas S. Dablool
Keyword(s):  
Dna Extraction ◽  
Control Method ◽  
Extraction Procedure ◽  
Cost Effective ◽  
High Yield ◽  
Gram Negative Bacteria ◽  
Bacterial Dna ◽  
Gram Negative ◽  
E Coli

Several methods of Deoxyribonucleic acid (DNA) extraction have been applied to extract bacterial DNA. The amount and the quality of the DNA obtained for each one of those methods are variable. The study aimed to evaluate bacterial DNA extraction using conventional boiling method followed by alcohol precipitation. DNA extraction from Gram negative bacilli was extracted and precipitated using boiling method with further precipitation by ethanol. The extraction procedure performed using the boiling method resulted in high DNA yields for both E. coli and K. pneumoniae bacteria in (199.7 and 285.7μg/ml, respectively) which was close to control method (229.3 and 440.3μg/ml). It was concluded that after alcohol precipitation boiling procedure was easy, cost-effective, and applicable for high-yield quality of DNA in Gram-negative bacteria.

scholarly journals Energy efficiency and ecological quality of buildings by process control of heat supply systems

2018 ◽  
Vol 251 ◽  
pp. 03052 ◽  
Author(s):  
Andrey Benuzh ◽  
Sergey Fedorov ◽  
Ekaterina Orenburova
Keyword(s):  
Process Control ◽  
Heat Supply ◽  
Heat Supply System ◽  
Heat Transfer Fluid ◽  
Industrial Buildings ◽  
Operation Algorithm ◽  
And Control ◽  
Supply Systems ◽  
Continuous Heat

The article presents special characteristics of mathematical modeling of the process control a resource efficient heat supply system of industrial buildings and facilities, where constant temperature maintenance is especially critical for the process. A functional diagram of the operation of the continuous heat supply process is provided. The dependence of temperature at the point of heat-transfer fluid mixing on environmental is analyzed and control system operation algorithm is proposed.

Performance Improvement of SVPWM-Based Three-Phase Grid-Connected Inverters

2013 ◽  
Vol 732-733 ◽  
pp. 1261-1264
Author(s):  
Zhi Lei Yao ◽  
Lan Xiao ◽  
Jing Xu
Keyword(s):  
Dynamic Response ◽  
Control Strategy ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Grid Current ◽  
Current Controller ◽  
Three Phase ◽  
Reference Grid ◽  
Grid Connected Inverter

An improved control strategy for three-phase grid-connected inverters with space vector pulse width modulation (SVPWM) is proposed. When the grid current contains harmonics, the d-and q-axes grid currents is interacted in the traditional control method, and the waveform quality of the grid current is poor. As the reference output voltage cannot directly reflect the change of the reference grid current with the traditional control strategy, the dynamic response of the grid-connected inverter is slow. In order to solve the aforementioned problems, the d-and q-axes grid currents in the decoupled components of the grid current controller are substituted by the d-and q-axes reference grid currents, respectively. The operating principles of the traditional and proposed control methods are illustrated. Experimental results show that the grid-connected inverter with the improved control strategy has high waveform quality of the grid current and fast dynamic response.

scholarly journals Estimating the Time to Benefit for Preventive Drugs with the Statistical Process Control Method: An Example with Alendronate

Drugs & Aging ◽  
2016 ◽  
Vol 33 (5) ◽  
pp. 347-353 ◽  
Author(s):  
Esther M. M. van de Glind ◽  
Hanna C. Willems ◽  
Saeid Eslami ◽  
Ameen Abu-Hanna ◽  
Willem F. Lems ◽  
...  
Keyword(s):  
Process Control ◽  
Statistical Process Control ◽  
Control Method ◽  
Statistical Process

Optimized Non-Dead-Time Control of Inverter with Two-Phase Modulated SVPWM

2012 ◽  
Vol 562-564 ◽  
pp. 1531-1536
Author(s):  
Ming Xing Zhu ◽  
Jing Bo Shi
Keyword(s):  
Control Strategy ◽  
Pulse Width Modulation ◽  
Dead Time ◽  
Control Method ◽  
Short Circuit ◽  
Two Phase ◽  
Zero Crossing ◽  
Time Control ◽  
Bus Voltage ◽  
Current Zero

In the inverter control system, two-phase modulated space vector pulse width modulation (SVPWM) algorithm has the advantages of minimum switch loss and higher utilization of direct current (DC) bus voltage. Non-dead-time control strategy can eliminate the problems of the dead time effects. But the traditional non-dead-time control strategy heavily depends on the current zero-crossing detection, which may cause the output voltage distortion or even a short circuit. Based on the analysis of the reason for the distortion, a new optimized non-dead-time control method is proposed. Two methods for the detection of the overlapping area are enumerated. The conclusions are confirmed by the simulation results with MATLAB/ SIMULINK.

The Application of S7-200 PLC Reactive Compensation Device in Small Substation

2012 ◽  
Vol 479-481 ◽  
pp. 1476-1480
Author(s):  
Qing He Chu ◽  
Wen Si Cao ◽  
Zhen Nie
Keyword(s):  
Reactive Power ◽  
Control Method ◽  
High Reliability ◽  
Reactive Power Compensation ◽  
Control Device ◽  
Reactive Compensation ◽  
Reconstruction Project ◽  
Compensation Device ◽  
And Control

In the present rural power grid reconstruction project ,according to the problems of capacitor reactive power compensation in rural small substation. Take a small substation for instance, according to its operation and control method, set the criterion of the capacitor bank switching. A new high reliability, flexible reactive power compensation control device based on s7-200 PLC is designed. It plays an important role in improving the power supply , guaranteeing the quality of voltage, reducing the loss of rural power gid.

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