Semi-Electrical Conductivity of Gelcast Alumina Sintered under Nitrogen Atmosphere

2006 ◽  
Vol 11-12 ◽  
pp. 493-496 ◽  
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.

Tribological Evaluation of Electrical Resistance of Lubricated Contacts

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Yan Chen ◽  
Hong Liang
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistance ◽  
Factors Affecting ◽  
Testing Conditions ◽  
Lubricating Oils ◽  
Alternative Design ◽  
Lubricated Contacts ◽  
Lubricating Film ◽  
Ohmic Behavior

Abstract We report a tribo-electrochemical configuration to conduct in situ measurement of electrical conductivity and thickness of lubricating oils against friction. Results showed the non-ohmic behavior of a lubricating film in the hydrodynamic regime. Properties of lubricants and testing conditions are factors affecting the performance. The approach reported here opens windows for future investigation in the fundamentals of lubrication and alternative design of next-generation lubricants.

Fabrication of Conductive Alumina by Gelcasting and Reduction Sintering

2006 ◽  
Vol 317-318 ◽  
pp. 657-660 ◽  
Author(s):  
Minoru Takahashi ◽  
Koichiro Adachi ◽  
Ruben L. Menchavez ◽  
Masayoshi Fuji
Keyword(s):  
Electron Microscopy ◽  
Electrical Resistance ◽  
Nitrogen Atmosphere ◽  
X Ray Diffraction ◽  
Electrically Conductive ◽  
X Ray ◽  
New Process ◽  
Plastic Mould ◽  
Scanning Electron

In this study, we propose a new process to fabricate electrically conductive alumina by gelcasting and reduction sintering. The process used the conventional gelcasting method except for varying amounts of monomer at 2.8, 5.5, and 8.0 wt.% relative to the weight of the slurry. In the plastic mould, the slurry was under in situ solidification for 3 hrs at 25oC to achieve gelation. The freshly gelled bodies were demolded, carefully dried, and then sintered at 1100oC, 1300oC, and 1550oC in nitrogen atmosphere. The holding times at 1100oC and 1300oC was 2 hours, while at 1550oC were 2, 4, and 6 hrs. The sintered alumina body was characterized by electrical property, X-ray diffraction, and scanning electron microscopy. Results showed that monomer additions and sintering schedule significantly affect in lowering electrical resistance. The low value was 3.6×106 +cm at 8.0wt.% monomer addition and sintering at 1550oC for 2 hrs. The effect of physical properties on electrical conductivity and the corresponding reaction mechanism were discussed in details.

scholarly journals Electrical Conductivity of PA6/Graphite and Graphite Nanoplatelets Composites using Two Processing Streams

2021 ◽  
Vol 5 (1) ◽  
pp. 19-31
Author(s):  
M. Umar ◽  
M. I. Ofem ◽  
A. S. Anwar ◽  
M. M. Usman
Keyword(s):  
Electrical Conductivity ◽  
Percolation Threshold ◽  
Carbon Composite ◽  
Graphite Nanoplatelets ◽  
Particulate Carbon ◽  
The Matrix ◽  
Sonication Technique ◽  
Carbon Fillers ◽  
Made In

The percolation threshold (PT) of any polymer/particulate carbon composite depends on the processing, the dispersed state of the filler, the matrix used and the morphology attained. Sonication technique was used to make PA6/G and PA6/GNP composites employing in situ polymerisation, after which their electrical conductivity behaviours were investigated. While overhead stirring and horn sonication were used to distribute and disperse the carbon fillers, the composites were made in 2 streams 40/10 and 20/20. The 40/10 stream implies that while dispersing the carbon fillers in PA6 monomer, 40% amplitude of sonication was applied for 10 minutes whereas the 20/20 stream implies 20% amplitude of sonication for 20 minutes. In both streams, the dispersing strain imparted on the monomer/carbon mixture was 400 in magnitude. Purely ohmic electrical conductivity behaviour was attained at 9.75 G wt. % for IG 40/10 system. For composites in the IG 20/20 system, same was attained at 10.00 G wt. %. Electrical conductivity sufficient for electrostatic discharge applications was achieved above 15 G wt. % in the IG 40/10 system. Using the power law percolation theory, percolation threshold was attained at 9.7 G wt. % loading in IG 40/10 system, while same was attained at 7.6 G wt. % loading in IG 20/20 system. For the GNP based systems, percolation threshold occurred at 5.2 GNP wt. % in the INP 40/10 system whereas same occurred at 7.4 GNP wt. % in the IG 20/20 system.

Influences of oxygen impurity contained in nitrogen on the reaction of titanium with nitrogen

2009 ◽  
Vol 24 (7) ◽  
pp. 2400-2408 ◽  
Author(s):  
Fu-Hsing Lu ◽  
Bor-Feng Jiang ◽  
Jen-Li Lo ◽  
Mu-Hsuan Chan
Keyword(s):  
Low Temperatures ◽  
Nitrogen Atmosphere ◽  
Model System ◽  
Oxygen Impurity ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
X Ray ◽  
Partial Pressures

In this work, Ti pellets were selected as a model system to investigate the influences of oxygen impurity in nitrogen gas on the reaction of a metal with the nitrogen. Analyzing changes in the in situ oxygen partial pressures when titanium specimens were annealed in the oxygen-containing nitrogen shows that the dissolution of oxygen in Ti and TiNx is exothermic, and the solubility decreases as the temperature increases. X-ray diffraction results show that nitridation of Ti occurred before oxidation, even in an oxygen-containing nitrogen atmosphere. Kinetics apparently predominates over thermodynamics at low temperatures in such a system.

Chemically reduced graphene oxide-coated knitted fabric imparted conductivity and outstanding hydrophobicity

2021 ◽  
pp. 004051752199547
Author(s):  
Min Hou ◽  
Xinghua Hong ◽  
Yanjun Tang ◽  
Zimin Jin ◽  
Chengyan Zhu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Chemical Reduction ◽  
Knitted Fabric ◽  
Mesh Structure ◽  
Reduced Graphene ◽  
Chemically Reduced Graphene Oxide ◽  
Modified Hummers Method

Functionalized knitted fabric, as a kind of flexible, wearable, and waterproof material capable of conductivity, sensitivity and outstanding hydrophobicity, is valuable for multi-field applications. Herein, the reduced graphene oxide (RGO)-coated knitted fabric (polyester/spandex blended) is prepared, which involves the use of graphite oxide (GO) by modified Hummers method and in-situ chemical reduction with hydrazine hydrate. The treated fabric exhibits a high electrical conductivity (202.09 S/cm) and an outstanding hydrophobicity (140°). The outstanding hydrophobicity is associated with the morphology of the fabric and fiber with reference to pseudo-infiltration. These properties can withstand repeated bending and washing without serious deterioration, maintaining good electrical conductivity (35.70 S/cm) and contact angle (119.39°) after eight standard washing cycles. The material, which has RGO architecture and continuous loop mesh structure, can find wide use in smart garment applications.

Municipal solid waste in situ moisture content measurement using an electrical resistance sensor

2003 ◽  
Vol 23 (7) ◽  
pp. 667-674 ◽  
Author(s):  
Nitin A. Gawande ◽  
Debra R. Reinhart ◽  
Philip A. Thomas ◽  
Philip T. McCreanor ◽  
Timothy G. Townsend
Keyword(s):  
Moisture Content ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Electrical Resistance ◽  
Content Measurement ◽  
Moisture Content Measurement

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

1919 ◽  
Vol 91 (635) ◽  
pp. 32-40 ◽  
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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