OPTIMIZATION OF PRESSURE TRANSDUCERS WITH SILICON MEMBRANE, REGARDING PIEZORESISTORS POSITION

2016 ◽  
Keyword(s):  
Silicon Membrane ◽  
Pressure Transducers

Strain measurement by means of bend contour microscopy

1989 ◽  
Vol 47 ◽  
pp. 210-211
Author(s):  
Philip D. Hren
Keyword(s):  
Strain Measurement ◽  
Large Angle ◽  
Single Crystal Silicon ◽  
Convergent Beam Electron Diffraction ◽  
Zone Axis ◽  
Silicon Membrane ◽  
Crystal Silicon ◽  
Contour Pattern ◽  
Convergent Beam ◽  
Low Symmetry

The pattern of bend contours which appear in the TEM image of a bent or curled sample indicates the shape into which the specimen is bent. Several authors have characterized the shape of their bent foils by this method, most recently I. Bolotov, as well as G. Möllenstedt and O. Rang in the early 1950’s. However, the samples they considered were viewed at orientations away from a zone axis, or at zone axes of low symmetry, so that dynamical interactions between the bend contours did not occur. Their calculations were thus based on purely geometric arguments. In this paper bend contours are used to measure deflections of a single-crystal silicon membrane at the (111) zone axis, where there are strong dynamical effects. Features in the bend contour pattern are identified and associated with a particular angle of bending of the membrane by reference to large-angle convergent-beam electron diffraction (LACBED) patterns.

Measurement of the Air Pressure for a Rotary Vane Compressor

2003 ◽  
Author(s):  
Yuan Mao Huang ◽  
Sheng An Yang
Keyword(s):  
Frequency Converter ◽  
Air Pressure ◽  
Cover Plate ◽  
Rotary Compressor ◽  
Compression Phase ◽  
Pressure Transducers ◽  
Compressor Rotor ◽  
Two Phases ◽  
Rotary Vane Compressor ◽  
Type Pressure

This study introduces an experimental method that can measure air pressures in the vane segments when a sliding-vane rotary compressor performs suction and compression phases in stable or unstable rotational speeds. When the air pressures of these two phases can be measured, the intake effect of the compressor’s inlet and the seal effect of the vane segments can be evaluated, respectively. Because a frequency converter provides unstable rotational speeds when it controls rotational speeds of a motor with a compressor, an encoder mounted on the output shaft of the motor was applied to record the angular location of the compressor rotor. Two strain gauge type pressure transducers were inserted into the cover plate of the compressor to measure air pressures in the vane segments. Comparing the signals of the encoder with pressure transducers, the air pressures in completions of suction and compression phases could be determined in stable or unstable rotational speeds. The air pressures when the compressor performed suction and compression phases were 99.5 kPa and 153 kPa, respectively, in 1400 rpm. The air pressure when the compressor performed suction phase decreased with the rotational speed faster than 800 rpm. The size or shape of the inlet port of the compressor should be enlarged or modified to provide the suction air pressure without dropping too much. The designed air pressure when the compressor performed compression phase was 244 kPa in 140 rpm, the manufacture precision of the compressor should be increased to decrease leakage.

Method for prolonged ambulatory monitoring of high-amplitude propagated contractions from colon

1991 ◽  
Vol 261 (2) ◽  
pp. G263-G268 ◽  
Author(s):  
M. D. Crowell ◽  
G. Bassotti ◽  
L. J. Cheskin ◽  
M. M. Schuster ◽  
W. E. Whitehead
Keyword(s):  
Bowel Movement ◽  
Anal Verge ◽  
Ambulatory Monitoring ◽  
High Amplitude ◽  
X Ray ◽  
Pressure Transducers ◽  
Peristaltic Activity ◽  
Bowel Prep ◽  
Asymptomatic Individuals ◽  
State Pressure

This study monitored high-amplitude propagated contractions (HAPCs) in ambulating subjects over a 24-h period using a new ambulatory recording system. Twelve healthy volunteers aged 34 +/- 5.96 yr participated. Approximately 12 h after a Colyte bowel prep, a small catheter (OD less than 3 mm), containing three solid-state pressure transducers spaced 5 cm apart, was positioned by flexible sigmoidoscope at 40-50 cm from the anal verge. A battery-operated data recorder sampled the pressure at each port at 1 Hz and stored the values on all ports if any port exceeded 75 mmHg. At the conclusion of the 24-h period, an X-ray was taken to confirm the location of the catheter. Fifty-four percent of all HAPCs preceded a bowel movement by less than or equal to 1 h. Forty-nine percent of all HAPCs occurred within 1 h after a high-fat meal, and 33% occurred within 1 h of morning awakening. Reverse propagated waves, not previously described in the colon, were observed in three individuals. Spontaneous high-amplitude caudally propagated contractions occur 6.9 +/- 1.5 times/24 h in the sigmoid colon in ambulating asymptomatic individuals and are temporally related to defecation and meals. Peristaltic activity is decreased during sleep. This recording technique was reliable and well tolerated in all participants.

Optimized electrochemical breakdown etching using temporal voltage variation for formation of nanopores in a silicon membrane

2020 ◽  
pp. 129323
Author(s):  
Nguyen Xuan Chung ◽  
Hithesh Kumar Gatty ◽  
Xi Lu ◽  
Miao Zhang ◽  
Jan Linnros
Keyword(s):  
Silicon Membrane ◽  
Voltage Variation

scholarly journals Investigation into the Relationship between Super-Knock and Misfires in an SI GDI Engine

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2099
Author(s):  
Jian Gao ◽  
Anren Yao ◽  
Yeyi Zhang ◽  
Guofan Qu ◽  
Chunde Yao ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Direct Injection ◽  
Exhaust Valve ◽  
Gasoline Direct Injection ◽  
Exhaust Pipe ◽  
Pressure Transducers ◽  
Spark Plug ◽  
Si Engines ◽  
Gdi Engine ◽  
The Relationship

The super-knock poses new challenges for further increasing the power density of spark ignition (SI) engines. The critical factors and mechanism connecting regarding the occurrence of super-knock are still unclear. Misfire is a common phenomenon in SI engines that the mixture in cylinder is not ignited normally, which is often caused by spark plug failure. However, the effect of misfire on engine combustion has not been paid enough attention to, particularly regarding connection to super-knock. The paper presents the results of experimental investigation into the relationship between super-knock and misfires at low speed and full load conditions. In this work, a boosted gasoline direct injection (GDI) engine with an exhaust manifold integrated in the cylinder head was employed. Four piezoelectric pressure transducers were used to acquire the data of a pressure trace in cylinder. The spark plugs of four cylinders were controlled manually, of which the ignition system could be cut off as demanded. In particular, a piezoelectric pressure transducer was installed at the exhaust pipe before the turbocharger to capture the pressure traces in the exhaust pipe. The results illustrated that misfires in one cylinder would cause super-knock in the other cylinders as well as the cylinder of itself. After one cylinder misfired, the unburned mixture would burn in the exhaust pipe to produce oscillating waves. The abnormal pressure fluctuation in the exhaust pipe was strongly correlated with the occurrence of super-knock. The sharper the pressure fluctuation, the greater the intensity of knock in the power cylinder. The cylinder whose exhaust valve overlapped with the exhaust valve of the misfired cylinder was prone to super-knock.

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