Study on the correlation between ion current integral signal and combustion pressure

2022 ◽  
Author(s):  
Zhanfeng Song ◽  
Xin Zhang ◽  
Boyuan Zhang
Keyword(s):  
Ion Current ◽  
Combustion Pressure

Quantitative Measurements on the Ion Etching of TMV

1973 ◽  
Vol 31 ◽  
pp. 336-337
Author(s):  
Irwin Bendet ◽  
Nabil Rizk
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Ion Current ◽  
Beam Diameter ◽  
Ion Etching ◽  
Preliminary Results ◽  
Quantitative Measurements ◽  
Monitoring Devices

Preliminary results reported last year on the ion etching of tobacco mosaic virus indicated that the diameter of the virus decreased more rapidly at 10KV than at 5KV, perhaps reaching a constant value before disappearing completely.In order to follow the effects of ion etching on TMV more quantitatively we have designed and built a second apparatus (Fig. 1), which incorporates monitoring devices for measuring ion current and vacuum as well as accelerating voltage. In addition, the beam diameter has been increased to approximately 1 cm., so that ten electron microscope grids can be exposed to the beam simultaneously.

Ultrastructural Features of Normal and Diseased Hair Revealed by Ion Beam Etching and Freeze Fracture

1975 ◽  
Vol 33 ◽  
pp. 358-359
Author(s):  
M. Spector ◽  
A. C. Brown
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ectodermal Dysplasia ◽  
Ion Beam ◽  
Freeze Fracture ◽  
Ion Current ◽  
Ion Beam Etching ◽  
Pili Torti ◽  
Argon Ion ◽  
Scanning Electron

Ion beam etching and freeze fracture techniques were utilized in conjunction with scanning electron microscopy to study the ultrastructure of normal and diseased human hair. Topographical differences in the cuticular scale of normal and diseased hair were demonstrated in previous scanning electron microscope studies. In the present study, ion beam etching and freeze fracture techniques were utilized to reveal subsurface ultrastructural features of the cuticle and cortex.Samples of normal and diseased hair including monilethrix, pili torti, pili annulati, and hidrotic ectodermal dysplasia were cut from areas near the base of the hair. In preparation for ion beam etching, untreated hairs were mounted on conducting tape on a conducting silicon substrate. The hairs were ion beam etched by an 18 ky argon ion beam (5μA ion current) from an ETEC ion beam etching device. The ion beam was oriented perpendicular to the substrate. The specimen remained stationary in the beam for exposures of 6 to 8 minutes.

Vacuum UV actinometry. Ion current measurements with enclosed light sources

1976 ◽  
Vol 73 ◽  
pp. 436-440 ◽  
Author(s):  
Jan A. Herman ◽  
Janusz Gawlowski
Keyword(s):  
Ion Current ◽  
Light Sources ◽  
Vacuum Uv

Small Molecule Permeation Across Membrane Channels: Chemical Modification to Quantify Transport Across OmpF

2018 ◽  
Author(s):  
Jiajun Wang ◽  
Jayesh Arun Bafna ◽  
Satya Prathyusha Bhamidimarri ◽  
Mathias Winterhalter
Keyword(s):  
Dwell Time ◽  
Covalent Binding ◽  
Channel Structure ◽  
Ion Current ◽  
E Coli ◽  
Current Fluctuation ◽  
Wide Range ◽  
Outer Membrane Channel ◽  
Biological Channels ◽  
Constriction Region

Biological channels facilitate the exchange of small molecules across membranes, but surprisingly there is a lack of general tools for the identification and quantification of transport (i.e., translocation and binding). Analyzing the ion current fluctuation of a typical channel with its constriction region in the middle does not allow a direct conclusion on successful transport. For this, we created an additional barrier acting as a molecular counter at the exit of the channel. To identify permeation, we mainly read the molecule residence time in the channel lumen as the indicator whether the molecule reached the exit of the channel. As an example, here we use the well-studied porin, OmpF, an outer membrane channel from <i>E. coli</i>. Inspection of the channel structure suggests that aspartic acid at position 181 is located below the constriction region (CR) and we subsequently mutated this residue to cysteine, where else cysteine free and functionalized it by covalent binding with 2-sulfonatoethyl methanethiosulfonate (MTSES) or the larger glutathione (GLT) blockers. Using the dwell time as the signal for transport, we found that both mono-arginine and tri-arginine permeation process is prolonged by 20% and 50% respectively through OmpF<sub>E181C</sub>MTSES, while the larger sized blocker modification OmpF<sub>E181C</sub>GLT drastically decreased the permeation of mono-arginine by 9-fold and even blocked the pathway of the tri-arginine. In case of the hepta-arginine as substrate, both chemical modifications led to an identical ‘blocked’ pattern observed by the dwell time of ion current fluctuation of the OmpF<sub>wt</sub>. As an instance for antibiotic permeation, we analyzed norfloxacin, a fluoroquinolone antimicrobial agent. The modulation of the interaction dwell time suggests possible successful permeation of norfloxacin across OmpF<sub>wt</sub>. This approach may discriminate blockages from translocation events for a wide range of substrates. A potential application could be screening for scaffolds to improve the permeability of antibiotics.

scholarly journals Parameter Determination and Ion Current Improvement of the Ion Current Sensor Used for Flame Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 697
Author(s):  
Hanqing Xu ◽  
Weijun Fan ◽  
Jianwei Feng ◽  
Peiliang Yan ◽  
Shuchan Qi ◽  
...  
Keyword(s):  
Contact Area ◽  
High Reliability ◽  
Ion Current ◽  
Parameter Determination ◽  
Current Sensor ◽  
Vertical Position ◽  
Excitation Voltage ◽  
Burner Exit ◽  
And Performance ◽  
Flame Monitoring

Flame monitoring of industrial combustors with high-reliability sensors is essential to operation security and performance. An ion current flame sensor with a simple structure has great potential to be widely used, but a weak ion current is the critical defect to its reliability. In this study, parameters of the ion current sensor used for monitoring flames on a Bunsen burner are suggested, and a method of further improving the ion current is proposed. Effects of the parameters, including the excitation voltage, electrode area, and electrode radial and vertical positions on the ion current, were investigated. The ion current grew linearly with the excitation voltage. Given that the electrodes were in contact with the flame fronts, the ion current increased with the contact area of the cathode but independent of the contact area of the anode. The smaller electrode radial position resulted in a higher ion current. The ion current was insensitive to the anode vertical position but largely sensitive to the cathode vertical position. Based on the above ion current regularities, the sensor parameters were suggested as follows: The burner served as a cathode and the platinum wire acted as an anode. The excitation voltage, anode radial and vertical positions were 120 V, 0 mm, and 6 mm, respectively. The method of further improving the ion current by adding multiple sheet cathodes near the burner exit was proposed and verified. The results show that the ion current sensor with the suggested parameters could correctly identify the flame state, including the ignition, combustion, and extinction, and the proposed method could significantly improve the magnitude of the ion current.

scholarly journals Capturing single molecules by nanopores: measured times and thermodynamics

2021 ◽  
Author(s):  
Alexander M. Berezhkovskii ◽  
Sergey M. Bezrukov
Keyword(s):  
Single Molecules ◽  
Ion Current

In nanopore sensing, transient interruptions of the nanopore ion current induced by capturing solute molecules are characterized by bimodal time distributions with most of the capture events being too fast to be experimentally resolved.

Ion Current Rectification Behavior of Bioinspired Nanopores Having a pH-Tunable Zwitterionic Surface

2017 ◽  
Vol 89 (7) ◽  
pp. 3952-3958 ◽  
Author(s):  
Jyh-Ping Hsu ◽  
Hou-Hsueh Wu ◽  
Chih-Yuan Lin ◽  
Shiojenn Tseng
Keyword(s):  
Ion Current ◽  
Ion Current Rectification ◽  
Current Rectification

Radiation-induced change of polyimide properties under high-fluence and high ion current density implantation

2004 ◽  
Vol 78 (7) ◽  
pp. 1067-1072 ◽  
Author(s):  
V.N. Popok ◽  
I.I. Azarko ◽  
R.I. Khaibullin ◽  
A.L. Stepanov ◽  
V. Hnatowicz ◽  
...  
Keyword(s):  
Current Density ◽  
Ion Current ◽  
High Fluence ◽  
Radiation Induced ◽  
Ion Current Density

A Mechanism for Inducing Ion Current in a Theta-Pinch

1982 ◽  
Vol 21 (Part 2, No. 10) ◽  
pp. L645-L646 ◽  
Author(s):  
Kei-Ichi Hirano
Keyword(s):  
Ion Current ◽  
Theta Pinch

Ion density and current distributions in a propagating current sheet, determined by microwave reflection technique

1969 ◽  
Vol 3 (2) ◽  
pp. 189-213 ◽  
Author(s):  
W. R. Ellis ◽  
R. G. Jahn
Keyword(s):  
Axial Current ◽  
Ion Current ◽  
Large Radius ◽  
Relative Importance ◽  
Current Pattern ◽  
Ion Density ◽  
Density Distributions ◽  
Hall Parameter ◽  
Electron Density And Temperature ◽  
Microwave Reflection

Electron and ion density distributions and the problem of electron/ion current partitioning are studied in a large radius Z-pinch in argon. Radial scans of the electron density and temperature proffles in the propagating sheet are obtained with a multi-purpose microwave interferometer which measures the complex refiexion coefficient from the plasma. At 70 GHz the probe resolves densities up to 1017 cm−3 over dimensions of ˜ 4 mm. Proffles of the electric and magnetic field components are obtained using standard probe techniques, and these data are used to calculate ion and electron current components in the sheet.Within the approximations of MHD theory, calculations show that the overall axial current pattern is built up of four interior zones alternately dominated by electron or ion current. This structure is observed to be closely correlated with variations of the Hall parameter, Wb/vc, about the value of unity through the sheet, which suggests that this parameter might be used as a guide to the relative importance of ion conduction in pinch discharge current sheets.

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