Carbon nanotube based separation columns for high electrical field strengths in microchip electrochromatography

Lab on a Chip ◽  
2011 ◽  
Vol 11 (12) ◽  
pp. 2116 ◽  
Author(s):  
Klaus B. Mogensen ◽  
Miaoxiang Chen ◽  
Kristian Molhave ◽  
Peter Boggild ◽  
Jörg P. Kutter
Keyword(s):  
Carbon Nanotube ◽  
Electrical Field ◽  
High Electrical Field ◽  
Separation Columns ◽  
Field Strengths

Simulation of Local Surface Modification in STM by ab initio Quantum Chemistry

1998 ◽  
Vol 05 (02) ◽  
pp. 493-499 ◽  
Author(s):  
V. S. Gurin
Keyword(s):  
Surface Modification ◽  
Ab Initio ◽  
Physical Nature ◽  
Atomic Scale ◽  
Level Shift ◽  
Electrical Field ◽  
High Electrical Field ◽  
Wide Range ◽  
Energy Level Shift ◽  
Ab Initio Approach

Surface modification by means of STM has became a well-known method for the artificial formation of nanometer and atomic scale structures. The physical nature of surface modification can consist in a wide range of phenomena (from mechanical indentation up to specific tip-induced chemistry). The high electrical field at the STM tip is considered to be the main feature of STM modification experiments. The field strength is comparable with intramolecular ones and can influence the chemical bonding in surface structures. The model of STM-stimulated modification is considered using the quantum-chemical ab initio approach for a surface cluster in the high electrical field. The destabilization effect, energy level shift, and bond polarization under the STM tip field occur and can show the atomistic nature of surface transformations in STM.

Fabrication of Carbon Nanotube Gas Sensor Using Step-Wise Dielectrophoretic Deposition Onto Interdigitated Pyrolyzed Carbon Electrodes

2021 ◽  
Author(s):  
Taajza Singleton ◽  
Lawrence Kulinsky
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Gas Sensor ◽  
Carbon Electrodes ◽  
Proof Of Concept ◽  
Nitrogen Gas ◽  
Electrical Field ◽  
The Creation ◽  
Field Lines

Abstract Carbon nanotubes (CNTs) have been implemented in the creation of many micro- and nano-devices due to their physical properties such as large volume-to-surface area as well as their high thermal and electrical conductivity. The paper describes a novel dielectrophoretic step-wise deposition of CNTs (that alternates deposition of CNTs and drying steps) between the interdigitated fingers of carbon electrodes. Multiphysics simulation illustrates the physics of CNT alignment along the electrical field lines that forms a basis for dielectrophoretic deposition of CNTs. This fabrication methodology resulted in the creation of a proof-of-concept nitrogen gas sensor.

Application of electrical fields to reduce chloride ingress into concrete structures

2021 ◽  
pp. 1-27
Author(s):  
Carla Driessen-Ohlenforst ◽  
Michael Raupach
Keyword(s):  
Chloride Ions ◽  
Chloride Ingress ◽  
Textile Reinforced Concrete ◽  
Electrical Field ◽  
Joint Research ◽  
Electrical Fields ◽  
Joint Research Project ◽  
Anodic Polarisation ◽  
Current Densities ◽  
Field Strengths

In the context of a joint research project, a system for monitoring, protection and strengthening of bridges by using a textile reinforced concrete interlayer has been developed which consists of two carbon layers with a spacing of 15 mm and a special mortar. This setup led to the idea to build up an electrical field between the carbon meshes, which suppresses the ingress of chlorides into the concrete. This paper focuses on the question which voltages and electrical field strengths are necessary to prevent critical chloride contents at the reinforcing steel. For this purpose, extensive laboratory tests have been performed, followed by a numerical simulation study. By applying an electrical field, the negatively charged chloride ions are forced to move to the upper carbon mesh that is polarized as an anode. It has been investigated whether the voltages to implement an electrochemical chloride barrier are smaller than they have to be for the common preventive cathodic protection. One advantage of this chloride barrier is that because of the lower current densities the anodic polarisation of the carbon meshes can be reduced. Therefore, different voltages, electrical field strengths, anode materials and anode arrangements were investigated.

Elimination of Tight Emulsions

2021 ◽  
Author(s):  
Haakon Ellingsen ◽  
Hikmat Jaouhar ◽  
Andreas Hannisdal
Keyword(s):  
Crude Oil ◽  
Separation Efficiency ◽  
Operating Temperature ◽  
Oil Fields ◽  
Water Removal ◽  
Water Production ◽  
Test Results ◽  
Electrical Field ◽  
High Electrical Field ◽  
Performance Specifications

Abstract Maturing oil fields can pose a severe challenge for separation of oil and water. Increasing water production and tie in of new fields into existing infrastructure may result in separators struggling to meet performance specifications. Operational challenges are particularly experienced when the facilities are processing cold feedstock and tight emulsions. Typical solutions for overcoming separation challenges would be increasing operating temperature, injecting an increased quantity of demulsifier chemicals, or installing new larger separators. These alternatives may not be economically attractive or feasible for other reasons. The ability to successfully operate existing plants with tight and water-rich emulsions without incurring significant added operating expenditure is perceived as a major advantage. This paper will share the results from testing on a separator operating with Flotta Gold crude oil. The oil is known to produce particularly tight emulsions at low temperatures. The ePack technology has been tested to study its capability of separating water and crude oil from tight emulsions by means of electrical forces. The force generated by the high electrical field can break even tight emulsions, and the test results shown have proven the ability to go from very low separation efficiency without the ePack, to more than 90% water removal with the ePack turned on. Testing with residence times of up to 19 minutes without the ePack was not able to surpass the performance of a three minutes residence time with the ePack energized.

The Effect of Mechanical Stress and Surface Tracking of 22 kV Cable Spacer

2015 ◽  
Vol 1119 ◽  
pp. 769-774
Author(s):  
Nutsopin Nilbunpot ◽  
Amnart Suksri
Keyword(s):  
Epoxy Resin ◽  
Mechanical Stress ◽  
Mechanical Load ◽  
Tracking Performance ◽  
Electrical Field ◽  
Resin Sample ◽  
Pure Epoxy ◽  
Surface Tracking ◽  
High Electrical Field ◽  
Insulation Performance

Surface tracking is one of the causes that degraded the property of cable spacer. This research investigates about the mechanical stress and surface tracking performance of 22 kV cable spacer. Sample were tested according to the surface tracking under IEC 60587 standard under modified condition by and addition of the mechanical weight on the surface of pure epoxy resin sample. The mechanical load use were 0 kg and increase from 5 kg until 15 kg. The results showed that mechanical stress has affected the surface degradation of an insulation performance when the mechanical load is increased combined with high electrical field.

Structural transition in liquid dimethylsulfoxide induced by a high electrical field

2001 ◽  
Vol 4 (1) ◽  
pp. 1-3 ◽  
Author(s):  
S. Markarian ◽  
Kh. Nerkararyan ◽  
W. Fawcett
Keyword(s):  
Structural Transition ◽  
Electrical Field ◽  
High Electrical Field
Sign in / Sign up

Export Citation Format

Share Document