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Surface Modification of Activated Carbon by Nitrogen Doping and KOH Activation for Enhanced Carbon Dioxide Adsorption Performance
(2025-01-01)
Chobsilp, Thanattha
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Treetong, Alongkot
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Yordsri, Visittapong
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Santasnachok, Mattana
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Charoeythornkhajhornchai, Pollawat
Nitrogen-doped activated carbon (N-AC) was successfully prepared by KOH-activation and nitrogen doping using ammonia (NH<inf>3</inf>) heat treatment. Coconut shell-derived activated carbon (AC) was heat-treated under NH<inf>3</inf> gas in the temperature range of 700℃–900℃. Likewise, the mixture of potassium hydroxide (KOH) and AC was heated at 800℃, followed by heat treatment under NH<inf>3</inf> gas at 800℃ (hereafter referred to as KOH-N-AC800). Scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) method were utilized to analyze morphology, crystallinity, chemical bonding, chemical composition and surface area. The surface area and porosity of N-AC increased with increasing NH<inf>3</inf> heat treatment. Similarly, the nitrogen content in the N-AC increased from 3.23% to 4.84 at% when the NH<inf>3</inf> heat treatment was raised from 700℃ to 800℃. However, the nitrogen content of N-AC decreased to 3.40 at% after using NH<inf>3</inf> heat treatment at 900℃. The nitrogen content of KOH-N-AC800 is 5.43 at%. KOH-N-AC800 and N-AC800 exhibited improvements of 33.66% and 26.24%, respectively, in CO<inf>2</inf> adsorption compared with AC. The enhancement of CO<inf>2</inf> adsorption of KOH-N-AC800 is attributed to the synergic effect of the nitrogen doping, high surface area, and porosity. The results exhibited that nitrogen sites on the surface play a more significant role in CO<inf>2</inf> adsorption than surface area and porosity. This work proposes the potential synergistic effect of KOH-activation and nitrogen doping for enhancing the CO<inf>2</inf> adsorption capacity of activated carbon.
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The Development of a High-Efficiency Small Induction Furnace for a Glass Souvenir Production Process Using Multiphysics
(2024-09-01)
Thongsri, Jatuporn
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Poopanya, Piyawong
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Sriphalang, Sanguansak
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Pattanapichai, Sorathorn
A small induction furnace (SIF), which has the important components of copper coils, a ceramic jig, and a graphite crucible, employed for a glass souvenir production process, has been developed as a form of clean technology for multiphysics, consisting of electromagnetics analysis (EA) and thermal analysis (TA). First, two experiments were established to measure parameters for multiphysics results validation and boundary condition settings. Then, the parameters were applied to multiphysics, in which the EA revealed magnetic flux density (B) and ohmic losses, and the TA reported a temperature consistent with the experimental results, confirming the multiphysics credibility. Next, a ferrite flux concentrator was added to the SIF during development. Multiphysics revealed that PC40 ferrite, as a flux concentrator with a suitable design, could increase B by about 159% compared to the conventional SIF at the power of 1000 W. As expected, the B increases alongside the increase in power applied to the coils, and is more densely concentrated in the flux concentrator than in other regions, enhancing the production process efficacy. Lastly, the developed SIF was employed in the actual process and received good feedback from users. The novel research findings are the developed SIF and methodology, exclusively designed for this research and practically employed for a glass souvenir production process.
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CFD—Assisted Expert System for N2-Controlled Atmosphere Process of Rice Storage Silos
(2024-03-01)
Angsrisuraporn, Phakkawat
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Samakkarn, Chawit
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Lekawat, Lertsak
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Singkhornart, Sasathorn
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Thongsri, Jatuporn
Since organic rice storage silos were faced with an insect problem, an owner solved this problem using the expert system (ES) in the controlled atmosphere process (CAP) under the required standard, fumigating insects with an N<inf>2</inf>, reducing O<inf>2</inf> concentration to less than 2% for 21 days. This article presents the computational fluid dynamics (CFD) assisted ES successfully solved this problem. First, CFD was employed to determine the gas flow pattern, O<inf>2</inf> concentration, proper operating conditions, and a correction factor (K) of silos. As expected, CFD results were consistent with the experimental results and theory, assuring the CFD’s credibility. Significantly, CFD results revealed that the ES controlled N<inf>2</inf> distribution throughout the silos and effectively reduced O<inf>2</inf> concentration to meet the requirement. Next, the ES was developed based on the inference engine assisted by CFD results and the sweep-through purging principle, and it was implemented in the CAP. Last, the experiments evaluated CAP’s efficacy in controlling O<inf>2</inf> concentration and insect extermination in the actual silos. The experimental results and owner’s feedback confirmed the excellent efficacy of ES implementation; therefore, the CAP is effective and practical. The novel aspect of this research is a CFD methodology to create the inference engine and the ES.
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Exploring Factors Affecting Consumer Behavioral Intentions toward Online Food Ordering in Thailand
(2022-07-01)
Inthong, Chidchanok
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Champahom, Thanapong
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Jomnonkwao, Sajjakaj
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Chatpattananan, Vuttichai
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Ratanavaraha, Vatanavongs
Due to the COVID-19 epidemic, ordering food online has become very popular. This study used a structural equation model to analyze the indicators that influence the decision to order food through a food-delivery platform. The theory of planned behavior and the technology acceptance model were both used, along with a new factor, the task–technology fit (TTF) model, to study platform suitability. Data were collected using a questionnaire given to a group of 1320 consumers. The results showed that attitudes toward on-line delivery most significantly affected the behavioral intentions of the consumers, followed by subjective norms. Among attitudes, perceived ease of use was the most significant, followed by perceived usefulness and trust. The study’s results revealed that TTF had the most significant impact on perceived ease of use, followed by perceived usefulness. This means that, if a food-ordering platform is deemed appropriate, consumers will continue to use it, and business sustainability will be enhanced.
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An Analysis of the Causal Relationships in Sustainable Consumption Behaviour (SCB) of Thai Student Science Teachers
(2021-01-01)
Pimdee, Paitoon
Having its originations in the 1987 UN Brundtland Report and the 1994 Oslo Symposium for sustainable consumption and production (SCP), education for sustainable development (ESD) has taken on global importance. As such, the study’s author sought to examine the causal relationships on sustainable consumption behaviour (SCB) of Thai student science teachers, as these are the leaders of tomorrow. The sample of 200 men and 200 women was obtained by use of multistage random sampling from ten state universities located across 5 Thai regions. The research tool was a 5-level response questionnaire consisting of 130 total items examining 18 observed variables, of which 97 items were positive in nature, while the remaining 33 items were negative in nature. The IOC was used to assess the questionnaire’s development process by the three teacher training experts. Subsequent item reliability testing of the pilot test group of 62 individuals used Cronbach’s Alpha (α) to judge reliability. Further data analysis made use of LISREL 9.1 software on the interrelationships of the latent variables psychological state (PS), environmental education (EE), psychological traits (PT), situation (SIT), as well as their effect on SCB. Results revealed that all the model’s causal variables had a positive effect on SCB, which can be explained by the combined influence of the factors (R2) being 92%. Furthermore, four factors were determined to influence SCB. Ranked in importance, these included SIT, EE, PS, and PT.

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