Analysis on Skew of Flat Belts in Two-Pulley Drives

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Weiming Zhang

A troublesome problem in flat belt transmission is a phenomenon known as skew, where the belt moves along the axial direction of the pulleys in operation. Skew usually is caused by angular misalignment of pulleys. Angular misalignment can be classified in two types, in-plane misalignment and out-of-plane misalignment. The former is where the axes of a pulley pair, driving and driven, are in the same plane but not parallel. The latter is where the axes of pulleys are not in the same plane. In this paper, both cases of the belt skew caused by out-of-plane and in-plane misalignment are addressed. Theoretical analyses are provided following discussions of the simulation results by finite element method. It is found: (1) in case of out-of-plane misalignment, the skew ratio, an index describing the degree of skew, is determined by a very simple formula in which only three geometrical parameters are required; (2) in case of in-plane misalignment, the skew is much more complicated than that in case of out-of-plane misalignment, and the skew ratio is determined by a system of nonlinear simultaneous equation. An iteration method for solving the system of nonlinear simultaneous equations is proposed. The theoretical analyses for both cases are verified with the FEM results and factors that influence the skew are discussed.

2006 ◽  
Vol 3 (3) ◽  
pp. 142-145
Author(s):  
P. Ravi Kumar ◽  
P. Bhanu Prakash ◽  
M. Murali Krishna ◽  
M. Santha Yadav ◽  
C. Asha Deepthi

Domperidone is an antiemetic and pantoprazole is an antiulcer drug. Simple, precise, rapid and selective simultaneous equation and Q- analysis UV spectrophotometric methods have been developed for the simultaneous determination of domperidone and pantoprazole from combined tablet dosage forms. The methods involve solving of simultaneous equations and Q-value analysis based on measurement absorptivity at 216, 287 and 290 nm respectively. Linearity lies between 1-15 mcg/mL for domperidone and 0-50 mcg/mL for pantoprazole.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 750
Author(s):  
Jun-Hao Lee ◽  
Pin-Kuan Li ◽  
Hai-Wen Hung ◽  
Wallace Chuang ◽  
Eckart Schellkes ◽  
...  

This study employed finite element analysis to simulate ultrasonic metal bump direct bonding. The stress distribution on bonding interfaces in metal bump arrays made of Al, Cu, and Ni/Pd/Au was simulated by adjusting geometrical parameters of the bumps, including the shape, size, and height; the bonding was performed with ultrasonic vibration with a frequency of 35 kHz under a force of 200 N, temperature of 200 °C, and duration of 5 s. The simulation results revealed that the maximum stress of square bumps was greater than that of round bumps. The maximum stress of little square bumps was at least 15% greater than those of little round bumps and big round bumps. An experimental demonstration was performed in which bumps were created on Si chips through Al sputtering and lithography processes. Subtractive lithography etching was the only effective process for the bonding of bumps, and Ar plasma treatment magnified the joint strength. The actual joint shear strength was positively proportional to the simulated maximum stress. Specifically, the shear strength reached 44.6 MPa in the case of ultrasonic bonding for the little Al square bumps.


1979 ◽  
Vol 16 (5) ◽  
pp. 779-789 ◽  
Author(s):  
Sandro Incerti ◽  
Valerio Parisi ◽  
Francesco Zirilli

Author(s):  
Wu Guochuan ◽  
Zhuang Biaonan ◽  
Guo Bingheng

24 double circular are tandem blade cascades of three different chord-ratios were investigated under different displacements in peripheral and axial direction. The inlet Mach number was 0.3. The Reynolds number based on blade chord was 2.7×105. The characteristics of the tandem blade cascades, such as the dependence of turning angle and coefficient of total pressure loss on incidence angle were obtained. The ranges of main geometrical parameters under optimal conditions were recommended.


Trees ◽  
2017 ◽  
Vol 31 (6) ◽  
pp. 1959-1971 ◽  
Author(s):  
Liyong Fu ◽  
Wei Xiang ◽  
Guangxing Wang ◽  
Kaijie Hao ◽  
Shouzheng Tang

INDIAN DRUGS ◽  
2016 ◽  
Vol 53 (10) ◽  
pp. 40-42
Author(s):  
A Palekar ◽  
◽  
S. Gaude ◽  
S. P. N. Pai

A simple, rapid, sensitive and economical UV spectrophotometric method was developed and validated for the simultaneous estimation of aspirin, caffeine, and orphenadrine citrate by Vierodt’s method in combined tablet dosage form and using mixture of 0.1 N HCl: ethanol (1:1) as solvent. The method employs designing and solving of simultaneous equations using 3 wavelengths, namely 226 nm, 272 nm, and 210 nm. Beer’s law was obeyed in the concentration range of 3-18 μg/mL for aspirin and 0.5-12 μg/mL for both caffeine and orphenadrine citrate with r2 value of 0.993, 0.991, and 0.991 respectively. Accuracy was determined by recovery studies and showed percent recovery ranging from 99.78-100% for aspirin, 96.10-100.92% for caffeine and 100.53-102.5% for orphenadrine citrate. The developed method can be used in QC laboratory for routine analysis to ensure the identity, purity, and performance of the drug product.


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