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Microstructure and Mechanical Properties Evolution of P235GH TC1 Steel Fire Tubes from a Fire-Tube Boiler with 14 Tons Capacity and 13 Bars Pressure
(2026-02-01)
Peeratatsuwan, Chaiyawat
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Ariyakul, Yossiri
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Sangsawang, Chatnugrob
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Sukprasertchai, S.
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Chowwanonthapunya, Thee
Comprehensive understanding of the microstructural degeneration and mechanical property degradation is of great importance to evaluate the reliability of used boiler tubes. This study describes the microstructural and mechanical evolution of P 235GH TC1 steel fire tubes which had been used in a fire-tube boiler for 3, 5, and 20 years. The investigation includes visual inspection, dimensional examination, chemical composition analysis, microstructural studies, scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy (SEM-EDX), x-Ray diffraction (XRD), and tensile tests. Results reveal that prolonged exposure to the actual fire boiler environment induced the high temperature and oxidizing atmosphere. This atmosphere facilitated the diffusion and oxidation of carbon and manganese, leading to the depletion of both elements in the aged tubes. The carbon and manganese depletion and the influences of thermal exposure stimulated pearlite decomposition, resulting in the formation of a ferrite-dominated microstructure. The presence of ferrite-dominated microstructure and the deterioration of the solid solution effect due to the carbon and manganese depletion caused a reduction of mechanical performance and plastic deformation resistance of aged tube. The microstructural evolution and mechanical property evaluation indicate the significance of additional microstructural investigation techniques, such as replica examination. This useful method should be included in the routine inspection of the age fire tubes, particularly for those in the prolonged service stage. The addition of this method can improve the reliability of regular inspections, especially for aged fire-tube boilers.
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Odor Source Localization Using Optimization Algorithm for Sensor Network with Movable Nodes
(2022-01-01)
Ariyakul, Yossiri
In this paper, the approach of using optimization algorithm for odor source localization was proposed. The concept uses a number of movable odor robots which comprise of an odor sensor, an anemometer and a wireless communication module to sense the targeted odor. The odor robots construct a movable sensor network by which the measured odor intensity is sent to the processor wirelessly to perform the localization in order to point out the position of the odor source by using optimization algorithm. The odor source localization map is obtained as a result. The map represents the possibility that the odor source is located at any point in the area. The result also implies the direction that the odor robots should move toward to reach the odor source remotely. The proposed method was experimentally evaluated by constructing the odor source localization map using three, four, and five sensor nodes in which the accuracy to predict the position of the odor source can be observed.
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4-ary Odor-Shift Keying Using Multi-channel Olfactory Display
(2019-10-01)
Wisayataksin, Sumek
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Angkasuwan, Panupong
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Ariyakul, Yossiri
Odor-shift keying, a data modulation technique that encodes digital data by varying odor presentation, was proposed in this paper. A multi-channel olfactory display was used as modulator to release multiple odors whose blending ratio representing different digital data. On the demodulator side, an odor sensing system is used to measure the released smells, revert them into electrical form which is then decoded into the original data by using digital signal processing. The proposed technique can enhance data transfer rate of the communication through odor as carrier. A preliminary experiment was conducted to validate the possibility of the concept of varying the presented odors to represent different binary data. Finally, a string was practically modulated and transmitted by using the proposed technique. The demodulation process can be performed successfully and the data transfer rate was doubled from the previous work.
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Data Modulation Technique Using Concentration of Odor Molecules
(2018-12-26)
Ariyakul, Yossiri
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Wisayataksin, Sumek
This study proposed a novel data modulation technique for digital communication by using a concentration of odor molecules. The information is encapsulated in an odor with controlled concentration levels in accordance with the binary representation of the message by using an olfactory display. The released odor is then measured by an odor sensing system where it is converted into electrical form that can be demodulated into the original data by using a digital filter and decision decoder. The experiments of sending a message by mean of odor in the UART format were performed to evaluate the possibility of the proposed molecular communication approach. The results reveal that the shape of signals detected by the odor sensor is associated with the information in the message, which confirms the reliability of data communication using this method.
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Development of a Low-cost Explosive Vapor Detector Using Metal Oxide Gas Sensors
(2018-08-21)
Ratchapakorn, Natchanon
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Ariyakul, Yossiri
This paper reports on the development of a low-cost electronics nose for explosive detection. The device is composed of an array of metal oxide gas sensors installed in a 3D printer-made sensor cell. The processor and control circuit were implemented on an FPGA. The proposed device is compact, low power, and low cost. Even though, the concentration of the vapors of explosive materials are at sub-part-per million, the capabilities to sense and identify eight explosive materials; trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), cyclotrimethylenetrinitramine (RDX), ammonium nitrate, urea powder, dynamite, black powder, and double-base propellant in an open-air environment were confirmed. The reproducibility of the proposed device was also verified.
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FPGA-based odor classification system using principal component analysis
(2018-08-13)
Tongyoo, Titiwoot
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Ariyakul, Yossiri
Odor classification has been increasingly applied in various applications. The types of odors can be identified by analyzing the output pattern obtained from the odor sensors with different sensitivities to the targeted odor. Therefore, the use of reconfigurable hardware offers advantage for the flexibility to work with a number of sensors with various characteristics. In this study, the FPGA was employed in the development of an odor classification system using principal component analysis (PCA). The soft processor system was developed so that the odor classification based on PCA can be performed standalone. A number of experiments in the closed system were conducted to evaluate the validity of the proposed odor classification system and its capability to identify the kinds of odors. The effectiveness to classify the odor samples was confirmed.
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Development of Olfactory display using solenoid valves controlled atomization for high concentration scent emission
(2017-01-01)
Ariyakul, Yossiri
This paper reports on the introduction of using atomization technique controlled by high-speed switching solenoid valves to present smells. Even though atomization has been widely used to release smells in commercial aroma diffusers, intensity of the released odor cannot be controlled. In this paper, the high speed ON/OFF switching of the solenoid valves enables the capability to control odor intensity precisely and rapidly and the atomization enables emission of high concentration odors compared with odors generated from natural evaporation method. The proposed olfactory display was evaluated by using an odor sensing system composed of a quartz crystal microbalance (QCM) gas sensor. As a result, the reproducibility and the capability to present high concentration odors with adjustable intensity of the proposed olfactory display were confirmed.
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Improvement of miniaturized olfactory display using electroosmotic pumps and SAW device
(2015-01-26)
Ariyakul, Yossiri
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Nakamoto, Takamichi
Recently, the study of using olfactory displays to release scents in virtual environment have been expanded. Our group have developed an olfactory display using electroosmotic (EO) pumps and a surface acoustic device (SAW) device. In this study, the improved olfactory display is described. The number of odor components was increased from 6 in the previous work to 8 whereas the size was further miniaturized so that it can be equipped on a headset. A visual-olfactory display system was also developed using the proposed olfactory display. The system can release scents in accordance with contents in the movie on Windows Media Player platform run on a PC. An experiment based on sensory test was performed to evaluate the capability to release scents of low volatile odorants within a short time and without odor remaining after the presentation.

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