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Evaluation of Precision and Sensitivity of Back Extrusion Test for Measuring Textural Qualities of Cooked Germinated Brown Rice in Production Process
(2023-08-01)
Kaewsorn, Kannapot
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Maichoon, Pisut
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Pornchaloempong, Pimpen
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Krusong, Warawut
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Sirisomboon, Panmanas
The textural qualities of cooked rice may be understood as a dominant property and indicator of eating quality. In this study, we evaluated the precision and sensitivity of a back extrusion (BE) test for the texture of cooked germinated brown rice (GBR) in a production process. BE testing of the textural properties of cooked GBR rice showed a high precision of measurement in hardness, toughness and stickiness tests which indicated by the repeatability and reproductivity test but the sensitivity indicated by coefficient of variation of the texture properties. The findings of our study of the effects on cooked GBR texture of different soaking and incubation durations in the production of Khao Dawk Mali 105 (KDML 105) GBR, as measured by BE testing, confirmed that our original protocol for evaluation of the precision and sensitivity of this texture measurement method. The coefficients of determination (R<sup>2</sup>) of hardness, toughness and stickiness tests and the incubation time at after 48 hours of soaking were 0.82, 0.81 and 0.64, respectively. The repeatability and reproducibility of reliable measurements, which have a low standard deviation of the greatest difference between replicates, are considered to indicate high precision. A high coefficient of variation where relatively wide variations in the absolute value of the property can be detected indicates high sensitivity when small resolutions can be detected, and vice versa. The sensitivity of the BE tests for stickiness, toughness and hardness all ranked higher, in that order, than the sensitivity of the method for adhesiveness, which ranked lowest. The coefficients of variation of these texture parameters were 31.26, 20.59, 19.41 and 18.72, respectively. However, the correlation coefficients among the texture properties obtained by BE testing were not related to the precision or sensitivity of the test. By obtaining these results, we verified that our original protocol for the determination of the precision and sensitivity of food texture measurements which was successfully used for GBR texture measurement.
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A modified optimal control for the mathematical model of dengue virus with vaccination
(2023-01-01)
Pongsumpun, Puntipa
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Lamwong, Jiraporn
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Tang, I. Ming
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Pongsumpun, Puntani
The dengue viruses (of which there are four strains) are the causes of three illnesses of increasing severity; dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Recently, dengue fever has reached epidemic proportion in several countries. Strategies or preventative methods have to be developed to combat these epidemics. This can be done by development of vaccines or by preventing the transmission of the virus. The latter approach could involve the use of mosquito nets or insecticide spraying. To determine which strategy would work, we test the strategy using mathematical modeling to simulate the effects of the strategy on the dynamics of the transmission. We have chosen the Susceptible-Exposed-Infected-Recovered (SEIR) model and the Susceptible, Exposed-Infected (SEI) model to describe the human and mosquito populations, repectively. We use the Pontryagin’s maximum principle to find the optimal control conditions. A sensitivity analysis revealed that the transmission rate (ɣ<inf>ℎ</inf>, ɣ<inf>v</inf>), the birth rate of human population (µ<inf>ℎ</inf>), the constant recruitment rate of the vector population (A) and the total human population (N<inf>ℎ</inf>) are the most influential factors affecting the disease transmission. Numerical simulations show that the optimal controlled infective responses, when implemented, cause the convergence to zero to be faster than that in uncontrolled cases.
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Vaccination’s Role in Combating the Omicron Variant Outbreak in Thailand: An Optimal Control Approach
(2022-10-01)
Lamwong, Jiraporn
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Pongsumpun, Puntani
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Tang, I. Ming
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Wongvanich, Napasool
COVID-19 is the name of the new infectious disease which has reached the pandemic stage and is named after the coronavirus (COVs) which causes it. COV is a single-stranded RNA virus which in humans leads to respiratory tract symptoms which can lead to death in those with low immunities, particularly older people. In this study, a standard dynamic model for COVID-19 was proposed by comparing a simple model and the optimal control model to reduce the number of infected people and become a guideline to control the outbreak. Control strategies are the vaccination rate and vaccine-induced immunity. An analysis was performed to find an equilibrium point, the basic reproduction number (Formula presented.), and conditions that generate stability by using Lyapunov functions to prove the stability of the solution at the equilibrium point. Pontryagin’s maximum principle was used to find the optimal control condition. Moreover, sensitivity analysis of the parameters was performed to learn about the parameters that might affect the outbreak in order to be able to control the outbreak. According to the analysis, it is seen that the efficacy of vaccines (Formula presented.) and the infection rate (Formula presented.) will affect the increased (decreased) incidence of the outbreak. Numerical analyses were performed on the Omicron variant outbreak data collected from the Thailand Ministry of Health, whose analyses then indicated that the optimal control strategy could lead to planning management and policy setting to control the COVID-19 outbreak.
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Impressive Response of Spin-Coated ZnO Nanoparticle UV-Sensitive Devices with Various Thicknesses under Different UV Intensities
(2021-09-01)
Pawong, Whongsatorn
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Wasapinyokul, Kamol
We fabricated ultraviolet (UV) detectors based on spin-coated pure zinc oxide (ZnO) nanoparticles with a metal–semiconductor–metal configuration. Devices with various ZnO layer thicknesses were characterized under different UV intensities, and their responsivity, sensitivity, response time, and recovery time analyzed. The following performance was achieved: responsivity of 99.8 A W<sup>−1</sup>, sensitivity of 531.1, and response and recovery times of 0.01 s and 0.07 s, respectively. Increasing the thickness revealed monotonic effects on each property: the responsivity decreased, the sensitivity decreased, and the response and recovery times increased, mainly because of the thin penetration depth of ZnO and the lengthened cracks on the thicker layer. However, the effects of the UV intensity on the parameters were not monotonic. Indeed, as the intensity was increased, the responsivity decreased, the sensitivity first increased then decreased, the response time first increased before shortening, while the recovery time consistently shortened. Such trends resulted from the combination of several mechanisms: shrinkage of depletion layers, saturation of excitons, and saturation of trapping states. Increasing the radiation-on time shortened both the response and recovery times. This device performance is impressive compared with devices with more complicated material formats, device structure, or fabrication methods. Some complications in the work are also discussed.
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INFLUENCE of COOLANT on COOLING PERFORMANCE SENSITIVITY of INTERNALLY CONVECTIVE TURBINE VANE
(2021-01-01)
Chotroongruang, Thanapat
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Prapamonthon, Prasert
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Thongdee, Rungsimun
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Thongmuenwaiyathon, Thanapat
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Sun, Zhenxu
Based on the Brayton cycle for gas-turbine engines, the high thermal efficiency and power output of a gas-turbine engine can be obtainable when the gas-turbine engine operates at high turbine inlet temperatures. However, turbine components e.g., inlet guide vane, rotor blade, and stator vane request high cooling performance. Typically, internal cooling and film cooling are two effective techniques that are widely used to protect high thermal loads for the turbine components in a stateof- the-art gas turbine. Consequently, the high thermal efficiency and power output can be obtained, and the turbine lifespan can be prolonged, also. On top of that, a comprehensive understanding of flow and heat transfer phenomena in the turbine components is very important. As a result, both experiments and simulations have been used to improve the cooling performance of the turbine components. In fact, the cooling air used in the internal cooling and film cooling is partially extracted from the compressor. Therefore, variations in the cooling air affect the cooling performance of the turbine components directly. This paper presents a numerical study on the influence of the cooling air on cooling-performance sensitivity of an internally convective turbine vane, MARK II using the computational fluid dynamics (CFD)/conjugate heat transfer (CHT) with the SST k- turbulence model. Result comparisons are conducted in terms of pressure, temperature, and cooling effectiveness under the effects of the inlet temperature, mass flow rate, turbulence intensity, and flow direction of the cooling air. The cooling-performance sensitivity to the coolant parameters is shown through variations of local cooling effectiveness, and area and volume-weighted average cooling effectiveness.
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Study of Nitride Thickness on Sensitivity IDEs Humidity Sensor Based on Graphene Oxide Sensing
(2020-03-01)
Pongampai, Satana
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Pengpad, Puttapon
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Meananeatra, Rattanawan
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Atiwongsangthong, Narin
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Muanghlua, Rangson
An interdigitaged electrodes (IDEs) humidity sensor was patterned like a combs by lithography process based on silicon bulk substrate with different nitride thickness (50, 100 and 150 nm). This research studied an effect of thick nitride on sensitivity of IDEs humidity sensor based APTES adhesive layer with graphene oxide (GO) sensing material. The IDEs humidity sensor based on GO was comparatively examined all thick nitride conditions. Capacitance value of fresh IDEs humidity sensor shown not significant change all nitride thickness but it affected to sensitivity after GO coating due to high GO densified onto IDEs surface. Scanning Electron Microscope (SEM) was analyzed GO distribution and surface morphology. Raman spectroscopy clearly revealed the GO presence. The sensitivity from 50 to 80 %RH for optimal 100 nm thick nitride shows improvement to 2.78 and 1.27 times or 278.35% and 127.46% based on 50 and 150 nm thick nitride, respectively. Furthermore, the optimal condition of IDEs humidity sensor shows a little response and recovery times (11 and 7 sec), low hysteresis (3.21%), fine repeatability as well as high accuracy on long-term ability test. It clearly demonstrated for high sensitivity of nitride IDEs humidity sensor based on GO sensing film deposition.
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Development of FBG sensing system for outdoor temperature environment
(2011-05-02)
Daud, S.
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Jalil, M. A.
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Najmee, S.
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Saktioto, Saktioto
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Ali, J.
We have experimentally designed a practical pass-through type FBG temperature sensor. The objective of this study is to design and built a prototype outdoor fibre Bragg grating (FBG) temperature sensor system. Its performance is evaluated at different times of the day. In order to reduce the optical losses of the FBG system, the shortest optical fiber path used to connect the FBG system is 55.5m. It has a total connector loss 4.0 dB and fibre loss of 0.3 dB thus giving a total loss of the system as 4.3 dB. The FBG sensor system is connected to the tunable laser source (TLS) and optical spectrum analyzer (OSA). The TLS is used to provide a broadband light source via a fibre optic cable of wavelength 1550 nm. The OSA is used to display the transmission and reflection spectrum to give the Bragg wavelength λB, bandwidth and power dip. The output spectrum can be obtained through direct connection to the FBG. Result of transmission and reflection spectrum show the sensitivity which is calculated from the slope of the graph. The FBG temperature sensor system has an average sensitivity of 9.1 pm (°C)-1 based on the transmission spectrum. It has an average sensitivity of 10.6 pm (°C)-1 based on the reflection spectrum.
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The design of an active band pass filter using uniformly distributed RC line
(2002-01-01)
Phantonglow, R.
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Janchitrapongvej, K.
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Tangtisanon, P.
This paper describes the realization of an active band pass filter circuit using a uniformly distributed RC line (URC). The proposed circuit structures resemble the Renz's band pass filter circuit, which consist of three URCs and a single positive gain amplifier. From the experimental results by Matlab and Pspice programs, it is showed that the behavior of the proposed band pass filter circuit gives a good narrow band and low sensitivity, better than Renz's band pass filter circuit.

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