Electrical Resistance Reduction Induced with CO2 Laser Single Line Scan of Polyimide

We conducted a laser parameter study on CO2 laser induced electrical conductivity on a polyimide film. The induced electrical conductivity was found to occur dominantly at the center of the scanning line instead of uniformly across the whole line width. MicroRaman examination revealed that the conductivity was mainly a result of the multi-layers (4–5) of graphene structure induced at the laser irradiation line center. The graphene morphology at the line center appeared as thin wall porous structures together with nano level fiber structures. With sufficient energy dose per unit length and laser power, this surface modification for electrical conductivity was independent of laser pulse frequency but was instead determined by the average laser power. High electrical conductivity could be achieved by a single scan of laser beam at a sufficiently high-power level. To achieve high conductivity, it was not efficient nor effective to utilize a laser at low power but compensating it with a slower scanning speed or having multiple scans. The electrical resistance over a 10 mm scanned length decreased significantly from a few hundred Ohms to 30 Ohms when energy dose per unit length increased from 0.16 J/mm to 1.0 J/mm, i.e., the laser power increased from 5.0 W to 24 W with corresponding power density of 3.44 × 10 W/cm2 to 16.54 W/cm2 respectively at a speed of 12.5 mm/s for a single pass scan. In contrast, power below 5 W at speeds exceeding 22.5 mm/s resulted in a non-conductive open loop.

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Heat-Up Performance of Catalyst Carriers—A Parameter Study and Thermodynamic Analysis

Energies ◽

10.3390/en14040964 ◽

2021 ◽

Vol 14 (4) ◽

pp. 964

Author(s):

Thomas Steiner ◽

Daniel Neurauter ◽

Peer Moewius ◽

Christoph Pfeifer ◽

Verena Schallhart ◽

...

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Transfer Coefficient ◽

Surface Area ◽

Internal Surface ◽

Installation Space ◽

Parameter Study ◽

Thin Wall ◽

Primary Role ◽

Internal Surface Area

This study investigates geometric parameters of commercially available or recently published models of catalyst substrates for passenger vehicles and provides a numerical evaluation of their influence on heat-up behavior. Parameters considered to have a significant impact on the thermal economy of a monolith are: internal surface area, heat transfer coefficient, and mass of the converter, as well as its heat capacity. During simulation experiments, it could be determined that the primary role is played by the mass of the monolith and its internal surface area, while the heat transfer coefficient only has a secondary role. Furthermore, an optimization loop was implemented, whereby the internal surface area of a commonly used substrate was chosen as a reference. The lengths of the thin wall and high cell density monoliths investigated were adapted consecutively to obtain the reference internal surface area. The results obtained by this optimization process contribute to improving the heat-up performance while simultaneously reducing the valuable installation space required.

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Detection of CO2-laser power variations via plasma tube impedance changes

Applied Physics ◽

10.1007/bf00895933 ◽

1980 ◽

Vol 21 (4) ◽

pp. 407-409 ◽

Cited By ~ 9

Author(s):

A. L. Scholtz ◽

G. Schiffner

Keyword(s):

Co2 Laser ◽

Laser Power ◽

Plasma Tube

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Concerning emotive phenomena. —Part III. The influence of drugs upon the electrical conductivity of the palm of the hand

Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character ◽

10.1098/rspb.1919.0016 ◽

1919 ◽

Vol 91 (635) ◽

pp. 32-40 ◽

Cited By ~ 4

Keyword(s):

Electrical Conductivity ◽

Healthy Subject ◽

Electrical Resistance ◽

Single Observation ◽

Motor Theory ◽

Few Data ◽

Palm Of The Hand

I possess comparatively few data concerning the action of drugs upon “Emotivity” or, to put it more specifically, upon the electrical resistance of the palm of the hand. Except as regards atropine, with which I have made many observations to test the sudo-motor theory of the reaction, I find in my notes only one satisfactory observation upon each of the following drugs: alcohol, chloroform, morphia, which I will transcribe. Obviously, a single observation of any drug can give only a single facet of its action under the particular conditions of experiment. It will, however, be clear that the results have, in each instance, been such as might be anticipated on general principles with one notable exception, viz., atropine. Experiment 1: Alcohol . —A healthy subject, F. G., aged 30, with an initial hand conductance = 17 γ ( = 60, 000 ohms) gave emotive reactions = 37 γ to the threat of a burn (match struck) and 2 γ to an actual slight burn, immediately before and immediately after the ingestion of 50 c. c. of whisky. The conductance remained unaltered at 17 γ .

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EXPERIMENTAL STUDY ON THE CO2 LASER CUTTING OF NOVEL POLYAMIDE 6/FLUOROELASTOMER THERMOPLASTIC ELASTOMERIC BLENDS

Rubber Chemistry and Technology ◽

10.5254/rct.14.85960 ◽

2015 ◽

Vol 88 (1) ◽

pp. 125-137 ◽

Cited By ~ 3

Author(s):

Shib Shankar Banerjee ◽

Anil K. Bhowmick

Keyword(s):

Low Power ◽

Co2 Laser ◽

Process Parameters ◽

Laser Power ◽

Laser Cutting ◽

Manufacturing Industry ◽

Cutting Speed ◽

Polyamide 6 ◽

Thermoplastic Elastomers ◽

Dynamic Vulcanization

ABSTRACT The application of the low-power CO2 laser-cutting process to fluoroelastomer (FKM), polyamide 6 (PA6), PA6/FKM thermoplastic elastomers (TPEs), and their thermoplastic vulcanizate (TPV) is reported. The main laser process parameters studied were laser power, cutting speed, and material thickness. The value of the top and bottom widths of the slit that were formed during laser cutting (kerf width), melted transverse area, and melted volume per unit time were measured and analyzed. Interestingly, TPE showed a smaller melted area and melted volume per unit time when compared with those values with PA6. Dynamic vulcanization further decreased these values. For example, the melted areas of PA6 and TPE were 510 × 10−3 mm2 and 305 × 10−3 mm2, respectively, which reduced to 238 × 10−3 mm2 for TPV at 40 W laser power. FKM showed the lowest value (melted area of 180 × 10−3 mm2). In addition, the output quality of the cut surface was examined by measuring the root mean square (RMS) roughness of the cut edges and heat-affected zone (HAZ). The obtained results indicated that the dimension of the HAZ and RMS roughness largely decreased in TPE when compared with PA6. For example, the HAZ of PA6 was 700 μm, which decreased to 230 μm for TPE at 40 W laser power. On the other hand, HAZ was nonexistent for FKM. Infrared spectroscopic analysis showed that there was no structural change of TPE or pristine polymers after applying the low-power CO2 laser on the surface of materials. CO2 laser cutting will be a new technique in this industry, and this analysis will assist the manufacturing industry to choose a suitable laser system with exhaustive information of process parameters for cutting or machining of rubber, TPEs, and TPVs.

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Semi-Electrical Conductivity of Gelcast Alumina Sintered under Nitrogen Atmosphere

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.11-12.493 ◽

2006 ◽

Vol 11-12 ◽

pp. 493-496 ◽

Cited By ~ 1

Author(s):

Ruben L. Menchavez ◽

Koichiro Adachi ◽

Masayoshi Fuji ◽

Minoru Takahashi

Keyword(s):

Electrical Conductivity ◽

Electrical Resistance ◽

Sintered Sample ◽

Carbon Composite ◽

Nitrogen Atmosphere ◽

Potential Candidate ◽

Nitrogen Gas ◽

Conductive Property ◽

Carbon Network

This work demonstrated an in-situ pyrolysis of gelcast alumina under reduction sintering to make alumina and carbon composite in providing semi-electrical conductivity. To increase the carbon content, the monomer was varied in the premix solution with reduction sintering in nitrogen gas. Two-probe method was used to measure electrical resistance of the sintered samples. The results revealed that the increase of monomer addition and sintering treatment were effective in reducing electrical resistance. The lowest value was 3.6×106-cm, which is a potential candidate for electrostatic shielding application. The reduction-sintered sample was re-sintered in an air in order to gain insight on the conductive path due to carbon network. Further tests such as XRD, TGA/DTA, and scanning electron microscopywere used to explain the semi-conductive property of the material.

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A Method For Determination Of Specific Electrical Resistance Of Steel And Nano-Coating Sputtered On It

Environment Technology Resources Proceedings of the International Scientific and Practical Conference ◽

10.17770/etr2011vol2.989 ◽

2015 ◽

Vol 2 ◽

pp. 118 ◽

Cited By ~ 1

Author(s):

Andris Martinovs ◽

Josef Timmerberg ◽

Konstantins Savkovs ◽

Aleksandrs Urbahs ◽

Paul Beckmann

Keyword(s):

Electrical Conductivity ◽

Magnetic Permeability ◽

Electrical Resistance ◽

Skin Effect ◽

Specific Electrical Resistance ◽

Specific Electrical Conductivity ◽

Relative Magnetic Permeability ◽

Nano Coating ◽

Cylindrical Steel

The paper describes methods developed to determine specific electrical conductivity and relative magnetic permeability of cylindrical steel items and nano-coatings deposited on them by sputtering. Research enables development of a new method for determination of thickness of vacuum deposited nano- coating that is based on application of skin effect.

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Bending Deformation of Pure Titanium Plate in CO2 Laser Forming

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.329.625 ◽

2007 ◽

Vol 329 ◽

pp. 625-630 ◽

Cited By ~ 1

Author(s):

Koichi Okuda ◽

Y. Sugie ◽

Masayuki Nunobiki

Keyword(s):

Co2 Laser ◽

Laser Power ◽

Pure Titanium ◽

Laser Spot ◽

Laser Forming ◽

Titanium Plate ◽

Bending Angle ◽

Spot Diameter ◽

Bending Deformation ◽

Laser Spot Diameter

This study deals with behaviour of bending deformation in CO2 laser forming process of titanium. CO2 laser forming technique was applied for a pure titanium plate with thickness of 1 mm to aim the development of new bending process. The experiments of laser forming were carried out with a CO2 laser machine. The bending angle and the temperature of workpiece were examined under the condition of various laser power, feed speed and laser spot diameter. Based on the experimental results, it was found that the bending deformation behaved greatly depending on the laser power and the laser spot diameter. The bending angle increased with an increase in the laser power. The bending direction tended to change from the laser irradiation side to its opposite side when the large laser spot diameter was applied.

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LOW TEMPERATURE RESISTIVITY OF TRANSITION ELEMENTS: VANADIUM, NIOBIUM, AND HAFNIUM

Canadian Journal of Physics ◽

10.1139/p57-098 ◽

1957 ◽

Vol 35 (8) ◽

pp. 892-900 ◽

Cited By ~ 36

Author(s):

G. K. White ◽

S. B. Woods

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Electrical Resistivity ◽

Electrical Resistance ◽

Thermal Resistivity ◽

Superconducting Transition ◽

Transition Elements ◽

Pure Niobium ◽

Temperature Resistivity ◽

The Ideal

Measurements of the thermal conductivity from 2° to 90 ° K. and electrical conductivity from 2° to 300 ° K. are reported for vanadium, niobium, and hafnium. Although the vanadium and hafnium are not as pure as we might wish, measurements on these metals and on niobium allow a tabulation of the "ideal" electrical resistivity clue to thermal scattering for these elements from 300 ° K. down to about 20 ° K. Ice-point values of the "ideal" electrical resistivity are 18.3 μΩ-cm. for vanadium, 13.5 μΩ-cm. for niobium, and 29.4 μΩ-cm. for hafnium. Values for the "ideal" thermal resistivity of vanadium and niobium are deduced from the experimental results although for vanadium and more particularly for hafnium, higher purity specimens are required before a very reliable study of "ideal" thermal resistivity can be made. For the highly ductile pure niobium, the superconducting transition temperature, as determined from electrical resistance, appears to be close to 9.2 ° K.

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Synthesis of (Poly-methyl Methacrylate-lead Oxide) Nanocomposites and Studying their A.C Electrical Properties for Piezoelectric Applications

Bulletin of Electrical Engineering and Informatics ◽

10.11591/eei.v7i4.969 ◽

2018 ◽

Vol 7 (4) ◽

pp. 547-551

Author(s):

Dalal Hassan ◽

Ahmed Hashim

Keyword(s):

Electrical Conductivity ◽

Dielectric Constant ◽

Dielectric Loss ◽

Methyl Methacrylate ◽

Electrical Resistance ◽

Lead Oxide ◽

Piezoelectric Materials ◽

Oxide Nanoparticles ◽

Poly Methyl Methacrylate ◽

Increase With Increase

Piezoelectric materials have been prepared from (poly-methyl methacrylate-lead oxide) nanocomposites for electronic applications. The lead oxide nanoparticles were added to poly-methyl methacrylate by different concentrations are (4, 8, and 12) wt%. The structural and dielectric properties of nanocomposites were studied. The results showed that the dielectric constant and dielectric loss of nanocomposites decrease with increase in frequency of applied electric field. The A.C electrical conductivity increases with increase in frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of poly-methyl methacrylate increase with increase in lead oxide nanoparticles concentrations. The results of pressure sensor showed that the electrical resistance of (PMMA-PbO2) nanocomposites decreases with increase in pressure.

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