Thai Science and Technology Journal

Simulation of Power Generation from Agricultural by-Products: Case Study of Bagasse and Cassava Pulp

2024-06-24T11:53:53+07:00

In this research, the simulation of a biomass power generation system was studied by comparing two processes: biomass combustion coupled with a steam turbine for power generation and biomass gasification coupled with a combined cycle system. The aim was to compare the efficiency of power generation system using sugarcane bagasse and cassava pulp as feedstocks. The simulated process was conducted using the Aspen Plus program to analyze various operating variables, including combustion temperature (800-1,000°C), air-to-fuel ratio (1-10), gasification temperature (800-1,000°C), and steam-to-biomass ratio (0.1-2.0). The results revealed that the most efficient power generation system, yielding maximum total power output and electrical efficiency, was biomass gasification coupled with a combined cycle system. The optimal operating conditions were gasification temperature at 1,000°C and steam-to-biomass ratio of 1. Under these conditions, the total power outputs from bagasse and cassava pulp were 4,995.10 kW and 4,985.08 kW, respectively. Moreover, the electrical efficiencies were 66.88% and 77.43% for bagasse and cassava pulp, respectively. In addition, for biomass combustion coupled with a steam turbine for power generation using bagasse and cassava pulp, the optimal operating conditions were a combustion temperature of 1,000°C and air-to-fuel ratio of 7. This resulted in comparable electricity outputs of approximately 700 kW, with electrical efficiencies of 13.91% and 15.89% for bagasse and cassava pulp, respectively.

Effect of Ground Pumice on the Properties of Fly Ash Geopolymer Paste

2024-06-25T16:04:30+07:00

This research aimed to investigate the effect of ground pumice (GPM) on flow value, setting time, compressive strength, and microstructure of fly ash geopolymer paste. The primary aluminosilicate material used was fly ash (FA) sourced from the thermal power plants in Thailand. Ground pumice was incorporated as a partial replacement for fly ash at replacement levels of 0%, 25%, 50%, 75%, and 100% by weight. A 10 M sodium hydroxide solution and sodium silicate solution were used as the alkali solution. The alkali solution-to-powder material ratio and sodium hydroxide solution-to-sodium silicate solution ratio of all the mixes were designed at 0.60 and 1.00 by weight, respectively. The result showed that increasing the replacement of FA with GPM reduced the flow value of the geopolymer paste while prolonging the setting time. The compressive strength of the FA geopolymer paste decreased as the GPM content increased. Microstructure analysis revealed that replacing FA with GPM negatively impacted the reaction at an initial age, resulting in a large number of unreacted particles and a weak microstructure. However, when 50% of FA was replaced with GPM and the paste was cured at room temperature, the geopolymer paste achieved a compressive strength exceeding 70 MPa at 90 days of age.

Mushroom Classification between Poisonous and Edible Mushrooms Using Machine Learning Techniques

2023-08-16T09:46:04+07:00

Traditional methods of identifying poisonous mushrooms can be both inaccurate and time consuming. The most common approach involves visually inspecting the mushroom's physical characteristics, which can be labor-intensive and challenging. This study investigated the use of machine learning techniques to classify mushrooms into two categories: edible and poisonous. A public dataset of 8,124 gilled mushrooms from 23 species within the Agaricus and Leiota genera was used to train five machine learning models: logistic regression, support vector machines (SVMs), decision trees, random forests, and XGBoost. Feature selection and extraction technique were applied to identify the most important attributes for classifying mushroom species. The results indicated that
the decision tree model, coupled with recursive feature elimination (RFE), achieved the best performance when using 60% of the data and focusing on three features: odor, gill size, and spore print color. This model produced an F1 score of 99.32%. Based on these finding, a prototype web application was developed for potential future use.

The Effect of Ripening Stage on Bioactive Compounds and Antioxidants Activity of Karanda (Carissa carandas Linn.)

2024-07-08T08:51:44+07:00

This research aimed to investigate the physical properties of karanda fruit at different ripening stages (raw, ripe, and overripe) from Songkhla and Chonburi provinces. The pH of karanda fruit was found to range from 2.80 to 3.14, the soluble solid content from 6 to 10 ^oBrix, and the percentage of acidity from 3.01% to 6.59%. The ripening stage and cultivation area significantly affected the levels of phenolic compounds, flavonoids, and anthocyanins (p<0.05). At the ripe stage, the hue angle indicated a red color, and the brightness (L*) was at its lowest. As the fruit ripened, there were increases in total anthocyanin content, total flavonoid content, total phenolic compounds, and antioxidant activity. At the overripe stage, the fruit exhibited the highest phenolic content (344.82±10.23 to 385.00±14.64 mg GAE/100 g), the highest flavonoid content (280.07±25.91 to 282.71±24.52 mg RE/100 g), the highest anthocyanin content (386.65±85.27 to 459.25±69.82 mg cyanidin-3-glucoside/100 g), and the highest antioxidant activity (86.19% to 91.22%). However, the highest vitamin C content was observed in the raw stage.

Development of Active Packaging from PVA-Cellulose-Biosynthesized AgNPs Composites

2024-07-12T10:13:56+07:00

This work aims to study and develop active packaging for the inhibition of Aspergillus ochraceus. Composite films were prepared using poly (vinyl alcohol) and cellulose extracted from oil palm fronds (PVA-C). FTIR and XRD results indicated that bleaching process, as well as the removal of lignin and hemicellulose from oil palm fronds, can be achieved in a single step using a mixed solution of H₂O₂ and NaOH. The effects of cellulose content on the physical properties and degradation behavior, assessed via soil burial, were investigated. It was found that the PVA-C composite film containing 5% w/w cellulose exhibited the best properties, including good cellulose dispersion, a water vapor permeability (WVP) of 14.04±3.09 g.m x 10^-⁴/m².hour.mmHg, a moisture content of 26.29% (±0.83), and complete degradation within 2 days. Cellulose aggregation was observed when cellulose content exceeded 5% w/w. Silver nanoparticles (AgNPs) were synthesized through a biosynthesis process using Garcinia cowa extracted solution at pH 7 and a reaction time of 2 h. The obtained AgNPs are spherical, with an average particle size of 25.9±5.6 nm. The antifungal properties of the composite film were evaluated base on varying AgNPs concentrations. It was found that the PVA-C5-Ag composite film exhibited strong antifungal activity against Aspergillus ochraceus. Therefore, the PVA-C5-Ag composite film demonstrated high potential as a biodegradable active packaging material for dried food in future applications.

Production of Udon Noodles Supplemented with Surimi and Purple Sweet Potato Powder

2023-11-24T15:11:14+07:00

The objective of this research was to develop udon noodles nutritionally supplemented with surimi and purple sweet potato powder (PSPP). The surimi amount was varied at four levels: 0% (control), 20%, 40%, and 60% by wheat flour. It was found that the highest tensile strength was observed at udon with 40% surimi. The addition of surimi resulted in higher water activity (a_w) and an optimum cooking time (p < 0.05), but the percentage of cooking loss was not significantly different (p > 0.05) compared to the control sample. Therefore, udon with 40% surimi was selected to test varying PSPP levels at five concentrations: 0% (control), 2.5%, 5.0%, 7.5%, and 10% of wheat flour. It was found that increasing the PSPP content resulted lower L* value, water activity (a_w) and tensile strength, but higher a* value, optimum cooking time and percentage of cooking loss compared to the control sample. Udon supplemented with 40% surimi and 7.5% PSPP exhibited tensile strength similar to that of the control udon made from 100% wheat flour. Therefore, this formula was selected for chemical composition analysis. The developed udon had higher moisture and protein content but lower fat and carbohydrate content compared to the control. Moreover, the antioxidant capacity increased by 30.20 times compared to the control sample.

Development of Simple Detection Method of the Gene Edited Low Gluten Wheat by Homo/Hetero-Duplexes and T7E1 Technique

2024-03-11T13:39:53+07:00

The development and application of agricultural gene-editing technology have been studied in various crops. The current regulation framework in Thailand is still under consideration. Therefore, the ability to detect gene-edited plants is essential for monitoring and verifying such plants as part of the preparation for the adoption of this technology. This study focuses on the research and development of an investigative method for detecting gene-edited wheat in a simpler and faster manner. Wheat with edited α-gliadin family genes in the sgAlpha-2 region, a group of genes responsible for controlling wheat gluten production, was used in this study. The gene editing involved the deletion of only a few bases from the genome, resulting in a significant reduction in gluten protein levels in the edited wheat. The homo/hetero duplex and T7 endonuclease-I (T7E1) assay was employed as the detection technique. This method relies on the principle of pairing complementary and non-complementary DNA strands. Mismatched DNA pairs form a characteristic loop in the editable region, which can be detected using gel electrophoresis analysis to differentiate DNA bands. This approach enables the identification of gene-edited plant samples effectively.

Evaluating the Risk of Cassava Mosaic Disease Using Imagery from Unmanned Aerial Vehicles and Synthetic Vegetation Indices.

2024-08-15T15:28:57+07:00

Cassava mosaic disease (CMD) is a viral disease that causes significant damage to cassava crops. Nakhon Ratchasima province in Thailand has experienced the highest prevalence of Cassava mosaic virus (CMV) outbreaks in the country, resulting in losses amounting to 1,605 million baht. The objectives of the study were 1) to analyze the synthetic vegetation indices (VI) of CMD occurrence locations, 2) to develop a risk map for CMD outbreaks, and 3) to analyze the relationship between vegetation indices and disease risk levels. Data on disease occurrence locations were collected, and aerial images were captured using an unmanned aerial vehicle (UAV) to analyze the vegetation indices. Seven indices were included: GRDI, VDVI, ExG, GCC, VARI, TGI, and GLI, to determine the index values at CMD occurrence locations. The data were then analyzed to assess disease risk levels, and vegetation index data were correlated with these risk levels using spatial statistics. The results revealed that 353 cassava plants were infected with CMD. The average values for the GRDI, VDVI, ExG, GCC, VARI, TGI, and GLI indices were 0.0359, 0.0417, 0.0674, 0.0352, 0.0636, 0.0296, and 0.0575, respectively. The highest moderate risk level was identified in 3,056 pixels. The Moran's I spatial autocorrelation coefficient for the vegetation index was 0.207, with a Z-score of 25.099. Most image pixels exhibited a high-high spatial clustering pattern, with high-risk points (Z-scores greater than 1.96 at a 99% confidence level) totaling 1,583 image points. This study contributes to improving the efficiency of monitoring and tracking CMD outbreaks in cassava crops, offering a valuable tool for disease management and prevention.