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A Kirigami-Engineered “Skeletal Framework” Composite for Ultralow Hysteresis and Highly Stable Strain Sensors
(2025-11-24)
Pongampai, Satana
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Chaithaweep, Kanokwan
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Pakawanit, Phakkhananan
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Charoonsuk, Thitirat
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Bongkarn, Theerachai
Wearable strain sensors are pivotal for next-generation human–machine interfaces, yet achieving high fidelity, robustness, and sustainability in a single platform remains a significant challenge. A primary obstacle is the inherent viscoelasticity of soft materials, which leads to signal drift and hysteresis. Here, we report a highly stretchable and ultrastable strain sensor fabricated through a synergistic integration of Kirigami-based structural engineering and nanocomposite material design. By introducing titanium dioxide nanotubes (TNTs) into a bacterial cellulose (BC) matrix, we create a composite with a unique internal “skeletal framework”. This framework substantially reduces viscoelastic losses, resulting in an exceptionally low hysteresis of 0.6% and ensuring robust performance with 99.4% signal stability over >10 000 cycles. Concurrently, the Kirigami-patterned structure enhances stretchability to ∼235% while the framework amplifies sensitivity 5.8-fold. The practical viability of this high-fidelity sensor is demonstrated through the precise and repeatable control of a robotic arm, where ultralow hysteresis proves more critical than raw sensitivity. The sensor’s eco-friendly, water-based fabrication aligns high-fidelity sensing with sustainable processing, presenting a clear design paradigm for engineering reliable and eco-conscious wearable electronic devices.
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Mathematical modeling and stability of SARS-CoV-2 transmission dynamics among domestic tourists in Thailand
(2025-02-01)
Sungchasit, Rattiya
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Pongsumpun, Puntani
The defined epidemiological model system explaining the spread of infectious diseases characterized with SARS-CoV-2 is analysed. The resulting SEIQR model is analysed in a closed system. It considers the basic reproductive value, the equilibrium point, local subclinical stability of the disease-free equilibrium point and local subclinical stability of the endemic equilibrium point. This is examined and the asymptotic dynamics of the appropriate model system are investigated. Further, a sensitivity analysis supplemented by simulations is prepared in advance to impose how changes in parameters involve the dynamic behaviours of the model.
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Study on chemical structure stability and properties of chitosan-incorporated tamarind seed kernel xyloglucan hydrogels
(2024-12-05)
Manamoongmongkol, Kanjana
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Sriprom, Pongsert
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Narkrugsa, Woatthichai
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Phumjan, Lamphung
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Permana, Lasuardi
This study investigated the stability of chitosan-incorporated tamarind seed kernel xyloglucan hydrogels prepared at different ratios after storage for three years. The physical hydrogel samples were studied using ratios of xyloglucan to chitosan between 1.5:1 and 4:1, comparing fresh hydrogel with hydrogel stored for three years. The hydrogels were analyzed for Fourier transform infrared characteristics, rheological behavior, flow rate, and zeta potential. After three years of storage, a reversible reaction was confirmed by C-H molecular stretching using Fourier transform infrared. All hydrogel samples exhibited pseudoplastic fluid characteristics with liquid-like behavior. The zeta potential of fresh hydrogel at 1.5:1 and 4:1 ratios was 27.700 ± 0.964 mV and 22.633 ± 0.929 mV, respectively, whereas after three years, it became 28.067 ± 1.106 mV and 18.867 ± 0.503 mV, respectively. The amount of xyloglucan significantly affected the zeta potential of the xyloglucan-chitosan hydrogel, leading to a decrease in the stability of the hydrogel at a 4:1 ratio. The stability of the hydrogel at a ratio of 1.5:1 was confirmed by pH and zeta potential measurements. In conclusion, the properties and behavior of the xyloglucan-chitosan hydrogel remained stable after three years of storage at a 1.5:1 ratio.
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Survival of probiotics Lactobacillus acidophilus TISTR1338 in a synbiotic-supplemented plant-based protein powder under various pH and temperatures
(2024-09-01)
Ardsiri, Panisa
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Chaoruangrit, Araya
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Pongsetkul, Jaksuma
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Bavisetty, Sri Charan Bindu
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Piewthongngam, Kullapapruk
The demand of plant-based protein has been remarkably increased, leading to the development of various plant-based protein products. Supplementation of synbiotic is an effective approach to improve food function. This study aimed to develop the formulation of plant-based protein product supplemented with synbiotic which provides high survivability of probiotic through various harsh conditions. Pea protein isolate (PPI), inulin, and glycerol at ratio 2:1:1 was supplemented with probiotic strain (Lactobacillus acidophilus TISTR1388) to develop as encapsulated synbiotic plant-based protein powder (SPBP). The developed formulation provided probiotic survival rate after freeze-drying and gastro-intestinal (GI) tract conditions at 95.0±2.1% and 62.4±6.1%, respectively. Whereas, probiotic as free-cells showed survival rate after freeze-drying at 78.9±0.4% and no survival cell was observed after GI tract digestion. Scanning Electron Microscope (SEM) analysis demonstrated SPBP's remarkable capacity to perfectly entrap probiotic cells with no visible cell damage. Herein, the stability of the SPBP was tested through various pH levels (3, 5, 7, and 9) and temperature levels (6±2°C, 26±2°C, and 55±2°C) in order to investigate the possibility of applying this product to various food categories. Results showed that developed SPBP survived through all tested pH and temperature levels for 3 h at least 88.9±6.6%. Shelf-life evaluation showed that SPBP provided survival rate of probiotic cells up to 96.2±2.4% an a<inf>w</inf> of 0.09±0.01 after 12 weeks of refrigerated storage. Overall, results revealed that SPBP had a strong possibility of being employed as a probiotic stabilizer that may be further developed for a functional food product.
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Synthesis of Crossover Network Using O′Shea′s Transformation via URC
(2024-01-01)
Janchitrapongvej, Kanok
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Chutchavong, Vanvisa
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Doungpan, Satawat
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Ngammongkolwong, Sudasawan
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Rattanathanawan, Pongpan
This paper describes method of synthesis two-way cross-over network, namely low-pass filter and high-pass filter. Firstly, we introduce synthesis method of obtain all-pass filter. We introduce O′Shea′s transformation P(s) = cosh√SRC and Wyndrum′s transformation W(s) = tanh√SRC via uniformly distributed RC (URC) network. After obtaining a desired all-pass filter, as an elementary process. We construct low-pass filter and high-pass filter by means of all-pass filter basis. Simulation results MATLAB are carried out and stability are also investigated.
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The current state of the art in internal additive materials and quantum dots for improving efficiency and stability against humidity in perovskite solar cells
(2022-12-01)
Sanglee, Kanyanee
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Nukunudompanich, Methawee
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Part, Florian
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Zafiu, Christian
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Bello, Gianluca
The remarkable optoelectronic capabilities of perovskite structures enable the achievement of astonishingly high-power conversion efficiencies on the laboratory scale. However, a critical bottleneck of perovskite solar cells is their sensitivity to the surrounding humid environment affecting drastically their long-term stability. Internal additive materials together with surface passivation, polymer-mixed perovskite, and quantum dots, have been investigated as possible strategies to enhance device stability even in unfavorable conditions. Quantum dots (QDs) in perovskite solar cells enable power conversion efficiencies to approach 20%, making such solar cells competitive to silicon-based ones. This mini-review summarized the role of such QDs in the perovskite layer, hole-transporting layer (HTL), and electron-transporting layer (ETL), demonstrating the continuous improvement of device efficiencies.
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Electrical resistivity survey for evaluating the undrained shear strength of soft Bangkok clay at some of the canal-side road investigation sites
(2022-01-01)
Chaiyaput, Salisa
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Sutti, Nut
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Suksawat, Taweephong
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Ayawanna, Jiratchaya
A resistivity-undrained shear strength equation was proposed in this work to investigate the relationship between the undrained shear strength and electrical resistivity of soft Bangkok clay. The field vane shear and screw driving sounding tests were used to evaluate the undrained shear strength of the soft Bangkok clay from 10 field investigations of the canal-side roads. Meanwhile, the electrical resistivity was collected by the low-cost nondestructive resistivity survey method. The relationship between the measured resistivity corresponding to the undrained shear strength was expressed as a linear equation of S<inf>u</inf> = 7.061ρ with a high statistical correlation (96.20%) between the undrained shear strength and resistivity. The validation between the predicted undrained shear strength from the equation and the measured undrained shear strength from the field sites confirmed the statistically significant relation of data and the reliability of the proposed equation. By using this equation, it successfully predicted the undrained shear strength of the soft Bangkok clay at a depth of 4.00–10.00 m below the ground surface of canal-side roads (zones C, D, and E in the zonation map). The proposed new equation from the resistivity survey in this work, therefore, serves as an alternative tool to fast estimate the shear strength of soft soil in the large area for the preliminary evaluation of road construction.
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Analysis of the Mathematical Model of Covid-19 in Thailand
(2021-08-20)
Pongsumpun, Puntani
The purpose of this research is to study the characteristics of the COVID-19 virus in Thailand. We formulate the mathematical model of COVID-19 virus. We separate the human populations into 6 groups. The infected human populations are separated into 2 classes such as infectious human population with no show symptom and infectious human population with symptoms. We study the behavior of the equilibrium points of the model. Determine the conditions for the local stability of the equilibrium points. Numerical results of mathematical models are presented. This will lead to a reduction in the mortality rate of patients in Thailand.
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Global stability of the transmission of hand-foot-mouth disease according to the age structure of the population
(2021-01-01)
Lamwong, Jiraporn
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Wongvanich, Napasool
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Tang, I. Ming
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Changpuek, Thurdkwun
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Pongsumpun, Puntani
This study investigates a transmission model of Hand-Foot-Mouth disease (HFMD) where the age structure of the population is taken into account. Most infections in Thailand occur among children below the age of 10 years, whose immunity to HFMD is lower than people of age greater than 10 years. Therefore, a mathematical model was developed in which the population was separated into two groups with respect to age: one comprised of children aged less than 10 years, and another comprised of the rest of the population. The reproductive number was obtained by the next-generation matrix approach. Global asymptotical stability of the developed model was assured using Lyapunov’s direct method. The model was validated by showing that the 2D and 3D trajectories of the numerical solutions for the different sub-population groups converged to the endemic equilibrium states when the reproduction number was greater than one, thus supporting the theoretical conclusions. Results show that the time series behaviors of the different normalized populations groups converge to the disease-free state when the values of the parameters are such that the basic reproductive number is 0.591481 (i.e., less than one) and to an endemic state when the values of the parameters are such that R<inf>0</inf> = 54.4523 and R<inf>0</inf> = 192.575 R = (i.e. greater than one). The results of this study can suggest ways for reducing the outbreak of this disease.
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STABILITY ANALYSIS AND ERROR ESTIMATES OF LOCAL DISCONTINUOUS GALERKIN METHOD FOR CONVECTION-DIFFUSION EQUATIONS ON OVERLAPPING MESH WITH NON-PERIODIC BOUNDARY CONDITIONS
(2021-01-01)
Chuenjarern, Nattaporn
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Wuttanachamsri, Kanognudge
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Yang, Yang
A new local discontinuous Galerkin (LDG) method for convection-diffusion equations on overlapping meshes with periodic boundary conditions was introduced in [14]. With the new method, the primary variable u and the auxiliary variable p = u<inf>x</inf> are solved on different meshes. In this paper, we will extend the idea to convection-diffusion equations with non-periodic boundary conditions, i.e. Neumann and Dirichlet boundary conditions. The main difference is to adjust the boundary cells. Moreover, we study the stability and suboptimal error estimates. Finally, numerical experiments are given to verify the theoretical findings.

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