Experimental Studies in Electro-Machining

1973 ◽  
Vol 95 (4) ◽  
pp. 945-950 ◽  
Author(s):  
N. H. Cook ◽  
G. B. Foote ◽  
P. Jordan ◽  
B. N. Kalyani
Keyword(s):  
Tungsten Carbide ◽  
Experimental Studies ◽  
Electrochemical Machining ◽  
Operating Voltage ◽  
Charged Interaction ◽  
Positively Charged

Three separate studies are discussed: (a) The effect of operating voltage, on electrochemical machining of tungsten carbide, was found to be very important, determining whether machining occurred or not. Best results were obtained in the 50–60 region. (6) “Discharge machining of glass” was studied in a system in which discharges between a tool and an electrolyte cause erosion of the glass. While the mechanism of erosion has not been identified, drilling rates up to 0.1 in/min. have been obtained. (c) Bubbles, formed by electrochemical machining (H2), behave as though positively charged. Interaction between the “charged” bubbles and an a-c field produce a desirable dispersion of the bubbles.

scholarly journals Design, fabrication and experimental studies of compliant flexure diaphragm for micro pump

2018 ◽  
Vol 7 (2.21) ◽  
pp. 66 ◽  
Author(s):  
R Roopa ◽  
P Navin Karanth ◽  
S M. Kulkarni
Keyword(s):  
Polyvinylidene Fluoride ◽  
High Performance ◽  
Experimental Studies ◽  
Single Layer ◽  
Operating Voltage ◽  
Driving Voltage ◽  
Element Analysis ◽  
Central Deflection ◽  
Large Numbers ◽  
Micro Pump

This study reports the performance of piezo actuated compliant flexure diaphragm for micropump and MEMS application. To achieve the high performance of diaphragm at the low operating voltage compliant flexure diaphragm design is introduced. Very limited work has done on the diaphragms of micropump. Large numbers of mechanical micropumps have used plane diaphragms. The central deflection of diaphragm plays an important role in defining the micropump performance. The flow rate of mechanical type micropump strongly depends on the central deflection of diaphragm. In this paper compliant flexure diaphragms are designed for micropump to achieve higher deflection at lower operating voltage. Finite element analysis of compliant flexure diaphragm with single layer PVDF (Polyvinylidene fluoride) actuator is simulated in COMSOL. Compliant flexure diaphragms with a different number of flexures are analyzed. The central deflection of compliant flexure diaphragms is measured for driving voltages of 90V to 140V in 10 steps. The deflection of the compliant flexure diaphragm mainly depends on flexure width and length, the number of flexures in the diaphragm, PVDF thickness, diaphragm thickness and driving voltage. Use of compliant flexure diaphragm for micropump will reduce the mass and driving voltage of micropump. An attempt is made to compare the results of compliant flexure diaphragms with plane diaphragms. From the experimental results it is noticed that the compliant flexure diaphragm deflection is twice that of the plane diaphragm at same driving voltage. Deflection of three flexure and four flexure compliant diaphragms is 10.5µm and 11.5µm respectively at 140V.  

Theoretical and Experimental Studies of Ethanol Decomposition and Electrooxidation over Pt-Modified Tungsten Carbide

2014 ◽  
Vol 161 (8) ◽  
pp. E3165-E3170 ◽  
Author(s):  
Thomas G. Kelly ◽  
Alan L. Stottlemyer ◽  
Xiaofang Yang ◽  
Jingguang G. Chen
Keyword(s):  
Tungsten Carbide ◽  
Experimental Studies ◽  
Ethanol Decomposition

Modelling and Analysis of Pulse Electrochemical Machining (PECM)

1994 ◽  
Vol 116 (3) ◽  
pp. 316-323 ◽  
Author(s):  
J. Kozak ◽  
K. P. Rajurkar ◽  
B. Wei
Keyword(s):  
Anodic Dissolution ◽  
Experimental Studies ◽  
Electrochemical Machining ◽  
Dimensional Accuracy ◽  
Tool Design ◽  
Machining Parameters ◽  
Electrolyte Flow ◽  
Pulse Electrochemical Machining ◽  
Interelectrode Gap ◽  
Continuous Current

A small interelectrode gap in Electrochemical Machining (ECM) results in improved dimensional accuracy control and simplified tool design. However, using a small gap with conventional ECM equipment adversely affects the electrolyte flow or mass transport conditions in the gap, leading to process instability. The most remarkable breakthrough in this regard is the development of ECM using pulsed current. Pulse Electrochemical Machining (PECM) involves the application of a voltage pulse at high current density in the anodic dissolution process. PECM allows for more precise monitoring and control of machining parameters than ECM using continuous current. Small interelectrode gap, low electrolyte flow rate, gap state recovery during the pulse-off times and improved anodic dissolution efficiency features encountered in PECM lead to improved workpiece precision and surface finish when compared with ECM using continuous current. This paper presents mathematical models for the PECM process which take into consideration the nonsteady physical phenomena in the gap between the electrodes, including the conjugate fields of electrolyte flow velocities, pressure, temperature, gas concentrations, current densities and anodic material removal rates. The principles underlying higher dimensional accuracy and simpler tool design attainable with optimum pulse parameters are also discussed. Experimental studies indicate the validity of the proposed PECM models.

scholarly journals Coarse-grained molecular dynamics simulations reveal lipid access pathways in P-glycoprotein

2018 ◽  
Vol 150 (3) ◽  
pp. 417-429 ◽  
Author(s):  
Estefania Barreto-Ojeda ◽  
Valentina Corradi ◽  
Ruo-Xu Gu ◽  
D. Peter Tieleman
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Experimental Studies ◽  
Lipid Binding ◽  
Coarse Grained ◽  
Glycoprotein P ◽  
P Glycoprotein ◽  
Dynamics Simulations ◽  
Positively Charged ◽  
Coarse Grained Molecular Dynamics

P-glycoprotein (P-gp) exports a broad range of dissimilar compounds, including drugs, lipids, and lipid-like molecules. Because of its substrate promiscuity, P-gp is a key player in the development of cancer multidrug resistance. Although P-gp is one of the most studied ABC transporters, the mechanism by which its substrates access the cavity remains unclear. In this study, we perform coarse-grained molecular dynamics simulations to explore possible lipid access pathways in the inward-facing conformation of P-gp embedded in bilayers of different lipid compositions. In the inward-facing orientation, only lipids from the lower leaflet access the cavity of the transporter. We identify positively charged residues at the portals of P-gp that favor lipid entrance to the cavity, as well as lipid-binding sites at the portals and within the cavity, which is in good agreement with previous experimental studies. This work includes several examples of lipid pathways for phosphatidylcholine and phosphatidylethanolamine lipids that help elucidate the molecular mechanism of lipid binding in P-gp.

Sheet cathode design and experimental study on the electrochemical machining of deep narrow slots in TB6 titanium alloy

2019 ◽  
Vol 234 (4) ◽  
pp. 801-813
Author(s):  
Feng Wang ◽  
Jianshe Zhao ◽  
Yanming Lv ◽  
Xiuqing Fu ◽  
Min Kang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Flow Velocity ◽  
Experimental Studies ◽  
Electrochemical Machining ◽  
Low Frequency ◽  
Specific Strength ◽  
Cathode Design ◽  
Narrow Slot ◽  
Tb6 Titanium Alloy ◽  
Side Gap

TB6 titanium alloy is extensively applied in lightweight vehicles, biomedicine, and other domains because of its high specific strength, excellent fracture toughness, and excellent corrosion resistance. Electrochemical machining is a non-contact processing technology that has significant advantages in processing materials that are difficult to cut, such as cemented carbide, high-temperature alloys, and titanium alloys. To improve the consistency of deep narrow slots fabricated in TB6 titanium alloy via electrochemical machining, a sheet cathode design and experimental studies were carried out in this work. Based on a unidirectional fluid–structure coupling simulation, the influence of the stiffener arrangement on the cathode rigidity and flow-velocity distribution was studied. Furthermore, by modifying the geometry of the stiffener, the cathode deformation was significantly reduced, and flow-velocity uniformity at the cathode outlet was improved. The influence of a superimposed low-frequency oscillation on the gap distribution and the profile error of a deep narrow slot was investigated experimentally. The results revealed that when an applied voltage of 24 V, an oscillation frequency of 50 Hz, and an amplitude of 0.05 mm were adopted, a highly homogeneous deep narrow slot with an entrance gap of 0.24 mm and a side gap of 0.33 mm was machined into the TB6 titanium alloy.

scholarly journals Multi Charged Ions in Accelerators

2020 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Nuclear Physics ◽  
Radiation Flux ◽  
Experimental Studies ◽  
High Energy ◽  
Neutral Particles ◽  
Wide Range ◽  
A Charge ◽  
Physics Experiments ◽  
Charged Ions ◽  
Positively Charged

We have presented the results of experimental studies of the characteristics of the products resulting from the expansion of plasmoids formed under laser irradiation at different wavelength: 0.69, 1.06 and 10.6µm. The radiation flux density was varied in a very wide range, which made it possible to obtain (different in intensity and energy) fluxes of charged and neutral particles. In this case, the positively charged ions have a charge from Z=1 to Z=30, which allows the use of laser plasma multi charged products in various nuclear physics experiments and super high energy accelerators [1].

scholarly journals Non-Contact Methods for High-Voltage Insulation Equipment Diagnosis during Operation

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5670
Author(s):  
Dmitry A. Ivanov ◽  
Marat F. Sadykov ◽  
Danil A. Yaroslavsky ◽  
Aleksandr V. Golenishchev-Kutuzov ◽  
Tatyana G. Galieva
Keyword(s):  
Electric Fields ◽  
High Voltage ◽  
Experimental Studies ◽  
Technical Condition ◽  
Contact Method ◽  
Operating Voltage ◽  
Remote Diagnostics ◽  
High Voltage Insulation ◽  
Voltage Support ◽  
Industrial Frequency

The article describes a complex of non-contact methods for remote diagnosis of high-voltage insulators as well as the two-channel method for remote diagnostics of the operating state of high-voltage insulators, based on the registration of partial discharges by electromagnetic and acoustic sensors. The presented device allows visual inspection and searches for faulty high-voltage equipment and a remote non-contact method of recording high-intensity electric fields of industrial frequency and their spatial distribution based on the electro-optical effect. The scheme of using the system for monitoring and diagnosing the technical condition of high-voltage support insulators of open switchgear is described. The results of experimental studies confirm the possibility of industrial applicability of the proposed method for non-contact remote diagnostics of the state of high-voltage insulators under operating voltage.

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