Measurement of Low Gas Concentration Using Photonic Bandgap Fiber

2006 ◽  
Vol 9 (2) ◽  
Author(s):  
Joanna Pawłat ◽  
Takahiro Matsuo ◽  
Tadashi Sugiyama ◽  
Toshitsugu Ueda
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Photonic Bandgap ◽  
High Sensitivity ◽  
Gas Absorption ◽  
Compact Set ◽  
Nitrogen Gas ◽  
Photonic Bandgap Fiber ◽  
The Core ◽  
Set Up

AbstractA high-sensitivity, compact set-up, enabling the precise measurement of a very low concentration of gas was designed. The micro-capillary gas flow phenomenon and the gas absorption inside fiber were estimated. Darcy - Weisbach equation for non-compressible flow and quasi - Panhandle equation for compressible gas flow were used for the calculation of the gas flow rate and gas velocity inside the photonic bandgap fiber. It was assumed that gas flowed mostly in the core. During the experimental part of work several types of optic fiber of various parameters were used. The core diameters ranged from 10.9 to 19.9 μm. It was possible to measure the flow rate of the nitrogen gas inside the fiber with various pressure differences on the opposite ends. Average velocity (Δp = 0.9 atm) ranged 0.17 m/s and was a little bit lower than expected.

PBG Fiber Low Concentration Gas Sensor

2008 ◽  
Vol 144 ◽  
pp. 163-168 ◽  
Author(s):  
Joanna Pawłat ◽  
Xue Feng Li ◽  
Takahiro Matsuo ◽  
Tadashi Sugiyama ◽  
Toshitsugu Ueda
Keyword(s):  
Gas Flow ◽  
Precise Measurement ◽  
Ion Beam ◽  
High Sensitivity ◽  
The Other ◽  
Compact Set ◽  
Gas Cell ◽  
Low Concentration ◽  
Photonic Bandgap Fiber ◽  
Set Up

The photonic bandgap fiber for a high-sensitivity, compact set-up, which enables the precise measurement of low concentration of gas was designed. Fiber was used instead the traditional glass gas cell during the spectroscopic measurements. Ar ion beam was proposed among the other methods to process the inlet and outlet surface of fiber and adjust it to the required parameters. The gas flow inside PBF fiber and its optical properties were investigated.

High-Precision Gas Sensor Based on Photonic Bandgap Fiber Cell

2009 ◽  
Vol 147-149 ◽  
pp. 131-136 ◽  
Author(s):  
Joanna Pawłat ◽  
Xue Feng Li ◽  
Tadashi Sugiyama ◽  
Takahiro Matsuo ◽  
Yurij Zimin ◽  
...  
Keyword(s):  
Gas Flow ◽  
Focused Ion Beam ◽  
Photonic Bandgap ◽  
Ion Beam ◽  
Sample Volume ◽  
Gas Cell ◽  
Gas Concentration ◽  
Photonic Bandgap Fiber ◽  
New Device ◽  
Microstructured Optical Fiber

As one of applications for Microstructured Optical Fiber, a new device for measurement of low gas concentration was designed. In the developed system the Photonic Bandgap Fiber (PBGF) was used as a gas cell. Proposed technique allowed reducing gas sample volume to 0.01 cc. The gas flow inside core of fiber was simulated and result was confirmed experimentally. During the experimental work several types of fibers of various parameters were specially designed, produced and used. Core diameters ranged from 10.9 μm to 700 μm. Various cutting techniques for fibers such as using the fiber cleaver, Focused Ion Beam and Cross Section Polisher were investigated.

Fabrication of Nitride Thin Films on Si Substrates by Atomic Layer Deposition Technique

MRS Advances ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 165-170
Author(s):  
Shumpei Ogawa ◽  
Tatsuya Kuroda ◽  
Ryuga Koike ◽  
Hiroki Ishizaki
Keyword(s):  
Atomic Layer Deposition ◽  
Flow Rate ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Atomic Layer ◽  
Plasma Power ◽  
Gas Flow Rate ◽  
Nitrogen Gas ◽  
Nitrogen Radical ◽  
Atomic Layer Deposition Technique

AbstractRecently, Plasma Assisted Atomic Layer Deposition Technique will easily control the thickness and the composition of semiconductor films. The radical generated by using the plasma techniques, gave the decrease of the defect into the semiconductor films. In this investigation, the relationship between microwave plasma power, nitrogen gas flow rate and concentration of generated nitrogen radical, was evaluated. At the first, Plasma emission spectrum at microwave plasma power (0 to 400W) was measured using a mixed 200sccm argon gas and 10sccm nitrogen gas. Next, the plasma emission spectrum was measured in the mixing of nitrogen gas flow rate (0 to 40sccm) with 200sccm argon gas flow rate. At that time, the microwave plasma power was set to 200W. Nitrogen radical spectrum were identified from all the emission spectrum, and the nitrogen radical intensity was calculated. As a result, the nitrogen radical intensity became the largest at 200sccm argon gas flow rate and 10sccm nitrogen gas flow rate. In addition, the nitrogen radical intensity increased in proportion to the microwave plasma power. The concentration of generated nitrogen radical could be controlled by changing the microwave plasma power and the nitrogen gas flow rate. Mentioned above, nitride thin films will be obtained on Si Substrates by microwave generated remote plasma assisted atomic layer deposition technique.

INFLUENCE OF NITROGEN FLOW RATE IN REDUCING TIN MICRODROPLETS ON BIOMEDICAL TI-13ZR-13NB ALLOY

2016 ◽  
Vol 78 (5-10) ◽  
Author(s):  
Arman Shah ◽  
S. Izman ◽  
M. A. Hassan
Keyword(s):  
Flow Rate ◽  
Physical Vapor Deposition ◽  
Gas Flow ◽  
Detrimental Effect ◽  
Gas Flow Rate ◽  
X Ray Diffraction ◽  
Tin Coating ◽  
Nitrogen Gas ◽  
Deposition Parameters ◽  
Cathodic Arc

Cathodic arc physical vapor deposition (CAPVD) is one of the promising techniques that have a potential to coat titanium nitride (TiN) on biomedical implants due to its good adhesion and high evaporation rate. However, this method emits microdroplets which have the possible detrimental effect on the coating performance. Past studies indicated that micro droplets can be controlled through proper deposition parameters. In the present work, an attempt was made to study the effect of nitrogen gas flow rates (100 to 300 sccm) on TiN coating of the Ti-13Zr-13Nb biomedical alloy. Scanning electron microscopy (SEM) was used to evaluate surface morphology and coating thickness while crystal phase of the coated substrates was determined using X-Ray Diffraction (XRD). Image analysis software was employed to quantify microdroplets counts. Results show that higher nitrogen gas flow rate able to decrease a significant amount of microdroplets and concurrently increase the thickness of TiN coating. A mixed crystal planes of (111) and (220) are obtained on the coated substrates at this setting which exhibits denser structure with higher adhesion strength as compared to substrates coated at the lower N2 gas flow rate.

scholarly journals Characteristics of mass transfer between gas-liquid phases in a higee reactor

2014 ◽  
Vol 20 (4) ◽  
pp. 523-530 ◽  
Author(s):  
Zhang Zhenzhen ◽  
Guo Kai ◽  
Luo Huijuan ◽  
Song Junnan ◽  
Qian Zhi
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Gas Absorption ◽  
Diffusion Reaction ◽  
Flow Rates ◽  
Rotating Speed ◽  
Liquid Phases ◽  
Calculation Results

In the absorption process of gas-liquid phases in Rotating Packed Bed (RPB), the liquid flow on packing was assumed to be film-flow. Based on Higbie?s penetration theory, the diffusion-reaction model in RPB was introduced to calculate the rate of gas absorption. Taking CO2 (10%)+N2(90%) gas mixture and N-methyldiethanolamine (MDEA) aqueous solution as objects, the experiments of gas absorption were carried out at different gas flow rates, rotating speeds, temperatures, liquid flow rates and MDEA mass concentrations. The experimental data were compared with calculation results to found a good agreement in the rotating speed range of 400-1100r/min. In this range, the rate of decarburization was in direct proportion to rotating speed, temperature and liquid flow rate, and inversely proportion to gas flow rate and MEDA mass concentration. The maximum deviation between experimental data and calculation results was 10%. Beyond the rotating speed of 1100 r/min, the rate of decarburization was dependent on the dynamic balance of gas-liquid system. In this area, the rate of decarburization was inversely proportion to rotating speed.

scholarly journals Realization of Low Confinement Loss Acetylene Gas Sensor by Using Hollow-core Photonic Bandgap Fiber 

2021 ◽  
Author(s):  
Hassan Arman ◽  
Saeed Olyaee
Keyword(s):  
Gas Sensor ◽  
Photonic Bandgap ◽  
Single Mode ◽  
Relative Sensitivity ◽  
Gas Absorption ◽  
Confinement Loss ◽  
Core Radius ◽  
Hollow Core ◽  
Photonic Bandgap Fiber ◽  
Mode Interference

Abstract A hollow-core photonic bandgap fiber (HC-PBF) with high relative sensitivity and low confinement loss was designed. Some destructive circumstance such as propagation losses and mode interference can disrupt performance of the PBF. By considering optimum size of the hollow-core radius, we were able to improve confinement loss and the relative sensitivity. By optimization of the shape and size of the closest row of air holes to the hollow core, the quality of the mode distribution in the hollow-core was well improved. Simulation results confirm that, at an optimal and reasonable core radius, the relative sensitivity and confinement loss of the proposed gas sensor were improved to 96.5% and 0.11 dB/m, respectively. In addition, in order to better matching of optical power between single mode fiber (SMF) and HC-PBF, we could reduce the destructive effects of optical mode mismatch, by mode interference suppression. Furthermore, by optimization of fiber structural specifications such as air filling fraction and lattice constant, the PBF was changed to a single-mode waveguide. Considering the operation wavelength 1530 nm which is very close to the acetylene gas absorption wavelength, this fiber is appropriate to be a high sensitivity gas sensor to detect absorbing gases in the middle infrared range.

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