scholarly journals A Standard for Rotatory Power Measurement

ACTA IMEKO ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 48 ◽  
Author(s):  
Andreas Brüge ◽  
Harald Pfeiffer
Keyword(s):  
Rotatory Power ◽  
Power Measurement ◽  
National Metrology Institute ◽  
Safe Operation ◽  
Revolution Speed ◽  
Technical Details ◽  
The Revolution

<p class="Abstract">In Germany, the realisation and dissemination of the unit of rotatory power is a legal task of the national metrology institute aimed at ensuring the safe operation of ergometers for patients. At the Physikalisch-Technische Bundesanstalt, this task is carried out by means of a standard that can be operated both as a regulated brake and as a regulated drive, so that the effective torque and the revolution speed can be measured traceably. In this article, technical details and uncertainty calculations about this standard are given.</p>

Preparation of SiO2/PEG Shear Thickening System by Centrifugal Dispersion

2012 ◽  
Vol 560-561 ◽  
pp. 586-590 ◽  
Author(s):  
Biao Yang ◽  
Sheng Wang ◽  
Guo Zhi Xu ◽  
Fei Xin
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
High Speed ◽  
Rotation Speed ◽  
Loss Modulus ◽  
Shear Thickening ◽  
Angular Frequency ◽  
Revolution Speed ◽  
Centrifugal Dispersion ◽  
The Revolution

The nano-SiO2/polyethylene glycol (PEG) dispersion system was prepared by centrifugal mixing, and its rheological properties were investigated. The results showed the revolution and rotation speed during the centrifugal mixing have a significant effect on the rheological properties of SiO2/PEG system. When the revolution speed of the centrifugal mixer was fixed at a high speed of 1200rpm, the shear thickening effect of SiO2/PEG was gradually increased with the decrease of rotation speed, and the maximum viscosity (η) of 12340 mPa•s appeared at the rotation speed of 200 rpm. At the low revolution speed of 700 rpm, the increase of the rotation speed significantly enhanced the shear thickening effect. When the rotation speed was 700rpm, the maximum viscosity was up to 86130mPa s. In steady state experiments, the systems show a shear-thinning property under low shear rate. When the shear rate exceeded a critical value (γ= 24.92 s-1), the viscosity first increased, and then decreased sharply. In the dynamic experiments, with the increase of angular frequency (ω), the loss modulus (G″) also increased and the systems behaved as a shear-thickening fluid.

scholarly journals The study of the drying kinetic and the cutting performance in dried betel nut production machine

2018 ◽  
Vol 192 ◽  
pp. 03005
Author(s):  
Naruebodee Srisang ◽  
Siriwan Srisang ◽  
Thatchapol Chungcharoen
Keyword(s):  
Moisture Content ◽  
Cutting Performance ◽  
Raw Material ◽  
Betel Nut ◽  
Drying Temperature ◽  
Revolution Speed ◽  
Drying Kinetic ◽  
Nut Production ◽  
Drying Chamber ◽  
The Revolution

Betel nut kernel is an important raw material in the leather and dye industries. The quality control after harvest is necessary, especially, the excess moisture content may cause the spoilage. Therefore, this research aims to study the betel nut fruit drying using infrared ray combined with the rotated trays. The betel nuts fruits were placed in rotated trays. These trays were installed within drying chamber which had the infrared rod in 2 positions namely the center and wall of drying chamber. The drying temperature used at 80, 100 and 120°C. The revolution speed of tray was set at 2, 4 and 6 rpm. The dried betel nut fruits were cut into 2 pieces at the blade speed of 25, 30 and 35 rpm. The experimental results showed the installation of infrared rods at the center could decrease the moisture content faster than at the wall. The betel nut fruit should use the drying temperature of 120°C for 10 h and the revolution speed of 2 rpm. The blade speed of 30 rpm gave the most cutting performance about 76%. The colour of dried betel nut kernel (L*, a* and b*) did not significantly difference with the commercial betel nut.

Study on Sapphire Wafer Grinding by Chromium Oxide (Cr2O3) Wheel

2016 ◽  
Vol 1136 ◽  
pp. 311-316 ◽  
Author(s):  
Ke Wu ◽  
Naoki Yamazaki ◽  
Yutaro Ebina ◽  
Li Bo Zhou ◽  
Jun Shimizu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Chromium Oxide ◽  
Removal Rate ◽  
Semiconductor Industry ◽  
High Surface ◽  
Grinding Wheel ◽  
Sapphire Wafer ◽  
High Surface Quality ◽  
Revolution Speed ◽  
The Revolution

Finishing process of sapphire wafer is meeting huge challenge to fulfill the strict requirement of high surface quality in semiconductor industry. Fixed abrasive process, although can guarantee the profile accuracy, leaves damaged layer on the surface or subsurface of sapphire wafer. Chemical mechanical polishing (CMP) is famous for providing great surface roughness, however, sacrifices surface geometrical accuracy. Therefore, a new chromium oxide (Cr2O3) sapphire grinding wheel based on chemical mechanical grinding (CMG) principle has been developed and its performance has also been put into examination. The experiment result has demonstrated that Cr2O3 possesses an outstanding potential in terms of a high material removal rate of sapphire wafer, meanwhile, largely reduces surface roughness from about 150nm to below 10nm in 1 hour. In addition, the design of experiment (DOE) has also been carried out to study the effect of influencing factors towards ultimate surface roughness of sapphire wafer. It reveals that the revolution speed of sapphire wafer bears twice greater influence towards surface roughness than the revolution speed of grinding wheel.

Functional Neck Dissection: Three Decades of Controversy

1992 ◽  
Vol 101 (4) ◽  
pp. 339-341 ◽  
Author(s):  
Javier Gavilán ◽  
César Gavilán ◽  
Jesús Herranz
Keyword(s):  
Head And Neck Cancer ◽  
Surgical Technique ◽  
Head And Neck ◽  
Neck Dissection ◽  
Neck Cancer ◽  
Safe Operation ◽  
Technical Details ◽  
Functional Neck Dissection ◽  
Radical Approach

Functional neck dissection (FND) is a neck-functional, tumor-radical approach for the management of the neck in patients with head and neck cancer. Based on the anatomic knowledge of the lymphatic compartments of the neck, FND is a different surgical technique rather than a modification of the classic procedure described by Crile. From an oncologic viewpoint, FND is a relatively safe operation to treat the cervical spread from head and neck cancer as long as the indications and technical details are carefully followed. In this report, based on our experience with more than 1,000 FNDs, we analyze the history and the philosophy of the operation.

scholarly journals Experimental Research of Journal Orbit for Water-Lubricated Bearing

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaoyan Ye ◽  
Jing Wang ◽  
Desheng Zhang ◽  
Lanqian Hu ◽  
Xunan She
Keyword(s):  
High Pressure ◽  
Aspect Ratio ◽  
Pressure Distribution ◽  
Journal Bearing ◽  
Rotor System ◽  
High Pressure Pump ◽  
Pressure Pump ◽  
Revolution Speed ◽  
Circumferential Pressure ◽  
The Revolution

To study the transient dynamic characteristics of water-lubricated bearing-rotor system in seawater desalination high pressure pump, the water-lubricated bearing test device was designed and built based on the prototype of high pressure pump with 4-stage rotors. The test was conducted to study the journal orbit and circumferential pressure distribution of journal bearing. The result shows that, in startup stage, the journal whirled with little amplitude in low revolution speed, and as the revolution speed increased, the journal began to move irregularly. The hydrodynamic lubrication formed basically when close to the rated revolution speed, and there is stable whirling center and amplitude of the journal orbit. The circumferential pressure distribution of journal bearing changed severely and kept consistent with the change of journal orbit; when the revolution speed reached the rated speed, the pressure distribution is stable. We changed the radius clearance, the aspect ratio, and the rotating speed to analyze the influence on the bearing-rotor system at steady speed. In conclusion, the journal orbit and circumferential pressure of journal bearing are very stable when the clearance radius is 0.05 mm, the aspect ratio is 1, and the revolution speed is 3000 r/min.

The Revolution that Failed

2020 ◽  
Author(s):  
Brendan Rittenhouse Green
Keyword(s):  
The Revolution
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