Suan Sunandha Science and Technology Journal

Comparative Study on the Optical Properties of Sm3+ Doped Glasses with Shell-Based and Commercial Calcium Oxide Modifiers

Sun, 22 Feb 2026 00:00:00 +0700

This study focuses on the optical and basic physical properties of samarium (Sm³⁺)-doped glasses prepared using calcium oxide (CaO) derived from mussel and cockle shells as glass network modifiers, and compares them with commercial CaO. X-ray fluorescence (XRF) analysis showed that the shell-derived CaO possessed high purity, with CaO content exceeding 99% after calcination at 900°C for 5 hours. X-ray diffraction (XRD) results revealed that prior to calcination, the primary phase in the shells was calcium carbonate (CaCO₃), while after heat treatment, the dominant phase transformed into calcium oxide (CaO). This indicates successful thermal decomposition of CaCO₃ and effective phase transition under the given conditions. In terms of optical properties, the shell-derived glass samples exhibited higher emission intensity and longer lifetimes compared to the commercial CaO sample. The density, refractive index, and molar volume values were comparable across all samples, suggesting that the use of shell-derived CaO does not significantly alter the physical properties of the glass. These results demonstrate the potential of shell-derived CaO as a sustainable alternative raw material for the production of luminescent glasses, contributing to environmentally friendly and cost-effective materials development.

Human Fecal Contamination of Toilet Doors and Food Preparation Surfaces in Households with Poor-Quality Sanitation Facilities in Ibule-Soro, Nigeria

Timileyin Olanrewaju, Adewale Olalemi , Jumoke Olaleye — Mon, 23 Mar 2026 00:00:00 +0700

Contaminated surfaces are potential breeding habitats for pathogenic organisms. Toilet doors and food preparation surfaces may serve as fomites in the indirect transmission of pathogens as a result of fecal contamination. This study set out to determine the bacterial communities and levels of enteric bacteria on toilet doors and food preparation surfaces in households with poor-quality toilet facilities in Ibule-Soro, Nigeria. 24 Swab samples from toilet doors and food preparation surfaces were collected from each of the five households over a period of six months within 12 sampling events. The abundance and identity of bacteria in the samples were determined using both culture-based and molecular methods (16S rRNA gene sequencing). Risks factors of fecal contamination were also assessed. Results revealed that the concentration of Escherichia coli ranged from 2.15 to 2.64 log₁₀ CFU/ml) while Salmonella ranged from 1.07 to 2.15 log₁₀CFU/ml. The common bacterial phyla detected were Proteobacteria, Actinobacteria and Firmicutes while Proteobacteria was the most abundant (42.45%) phylum. Risk factors such as toilet facilities, most especially ‘No toilet’ and ‘Manageable access to soap’ exhibited high significant association with the presence and load of Enterobacter, Klebsiella, Proteus. Toilet doors had higher frequency of occurrence of enteric bacteria than food preparation surfaces but food preparation surfaces had higher load of enteric bacteria than toilet doors. Isolates from toilet doors had higher normal distribution pattern than isolates from food preparation surfaces. In order to protect human health from infections, the quality of the toilet facilities in the households must be improved, adequate hygiene practices must be encouraged and food preparation surfaces must be cleaned and sanitized regularly.

A Comparison of the Efficiency of Simple DNA Extraction Methods by Direct Amplification of rbcL gene in Capsicum annuum and Capsicum chinense

Kanya Anukulthanakorn; Sayrung Kaewtanmaung — Thu, 30 Apr 2026 00:00:00 +0700

Chilli landraces of Thailand are an essential spice in Thai cuisine. Taxonomically, they belong to the family Solanaceae, genus Capsicum. This study aimed to (i) survey the biodiversity of chilli varieties in Tambon Saylampong, Amphoe Thatako, Nakhon Sawan Province, and (ii) compare the efficiency of two DNA extraction methods, a commercial kit and NaOH extraction, through the direct amplification of the rcbL gene. A line transect method was used for the biodiversity survey and sample collection, covering a distance of one kilometer. Young leaves from each chilli variety were collected and used for DNA extraction using the commercial kit and NaOH extraction methods. The study found two chilli species comprising seven distinct varieties, Capsicum annuum consisted of five varieties: Chinda, Chee Fah, Khee Noo Si Moung, Khee Noo Khao, and Sai Pla Lai, and Capsicum chinense consisted of two varieties: Khee Noo Hom and Khee Noo Suan. DNA extracted using a commercial kit and NaOH extraction methods were available to measure the yield and purity by spectrophotometer. Regarding amplifying a partial sequence of the rcbL gene, DNA extracted using the commercial kit showed strong amplification in all samples. Some DNA samples of diluted DNA extracted using NaOH method were also successfully amplified, whereas all samples of non-diluted DNA extracted using NaOH method failed to amplify. These findings indicate that the commercial kit yields high-quality DNA suitable for polymerase chain reaction (PCR) applications. However, the NaOH extraction method presents a faster and more cost-effective alternative, though further optimization is needed to enhance its efficiency.

Hydrothermal Hydrolysis of Pretreated Corn Husk into Reducing Sugars Using Sulfonated Carbon-Based Solid Acid and Ionic Liquid

Katnanipa Wanchai, Jutawadee Mingmongkut — Fri, 29 May 2026 00:00:00 +0700

This study investigates the hydrothermal hydrolysis of pretreated corn husk into reducing sugars using a sulfonated carbonaceous solid acid catalyst (C-SO₃H) in combination with the ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl). The C-SO₃H catalyst was synthesized via one-step hydrothermal carbonization-sulfonation and subsequently characterized by FTIR, SEM, and acid-base titration. The catalyst exhibited abundant Brønsted acid sites (-SO₃H, -COOH, and -OH) with a total acidity of 1.25 mmol/g. The effects of reaction temperature, reaction duration, catalyst loading, and ionic liquid dosage on the hydrothermal hydrolysis of pretreated corn husk were systematically investigated. Under the optimal conditions (120°C, 3 h, 15 wt.% catalyst loading, and 1.5 g of [BMIM]Cl per gram of corn husk), the maximum total reducing sugar yield of 82.8% was achieved. The enhanced hydrolysis efficiency is attributed to the synergistic effect between the strong Brønsted acidity of C-SO₃H and the cellulose-dissolving capability of [BMIM]Cl under hydrothermal conditions. In addition, the catalyst demonstrated good recyclability, maintaining satisfactory activity over three consecutive cycles. These results highlight an efficient and environmentally friendly approach for the valorization of agricultural residues into reducing sugars, with potential applicability in biorefinery processes.

Developing a Machine Learning Model to Detect the Early Stage of Alzheimer's Disease in Individuals with Mild Cognitive Impairment Utilizing Brain Imaging

Sat, 30 May 2026 00:00:00 +0700

Alzheimer’s disease (AD), a form of dementia, significantly impairs an individual's ability to perform daily activities. The prevalence of AD patients in Thailand will increase to 1.1 million by 2030, marking AD as a critical concern in the nation's aging society. Mild Cognitive Impairment (MCI), often seen as a normal part of aging, has the potential to progress into AD. Early intervention in MCI cases could help delay the onset of AD. Our study focuses on creating a classification model leveraging neuroimaging data to distinguish between AD, MCI, MCI that has transitioned to AD (MCI_AD), and cognitively normal (CN) individuals. We utilized MRI brain images from the ADNI database, employing the FreeSurfer program to transform neuroimages into numerical data arrays for feature extraction. The study further included data preprocessing with standardization and feature selection by the scikit-learn library. Upon constructing five supervised machine learning models, we identified the one with the best performance through comparative analysis. The model’s effectiveness was evaluated using ROC curves, with the Support Vector Machine (SVM) model showing superior performance, achieving an area under the curve (AUC) of 0.764. Comparatively, Logistic Regression, NuSVC, Extra Trees Classifier, and MLP Classifier scored AUCs of 0.761, 0.758, 0.745, and 0.736, respectively. In summary, the SVM model demonstrated a notable ability to classify early stages of MCI and AD from other groups. Nevertheless, for further advancements in AD and MCI detection, exploring a wider array of datasets and feature extraction methodologies is imperative to improve the model’s performance.

The Traffic Flow Control Algorithm Based on Graph Theory together with the Maximum Flow: A Case Study on Consecutive Road at Pattani Hospital and City Hall

Areena Hazanee; Nifatamah Makje, Asma Yafaad, Aniruth Phon-On — Mon, 29 Jun 2026 00:00:00 +0700

This study proposes a traffic signal control algorithm for consecutive intersections surrounding Pattani Hospital and City Hall based on graph theory and maximum flow analysis. The traffic system is formulated as a flow network in which arc weights represent road capacities, and the Ford–Fulkerson algorithm is employed to determine the maximum feasible traffic flow. Optimal green signal durations for inbound approaches are subsequently derived from the resulting flow distribution to improve traffic performance. Furthermore, the study investigates the relationship between green signal duration and the maximum traffic clearance capacity of an intersection during a signal phase. Signal timing optimization is conducted with the objective of reducing vehicle delay and enhancing overall traffic efficiency. The analytical framework integrates effective road length with estimated traffic flow capacity derived from vehicle registration statistics in Pattani Province, while intersection traffic volumes are computed using fundamental kinematic principles. Numerical results indicate that while the proposed model successfully discharges all queued vehicles within a single green phase at certain intersections, residual queues still remain at highly congested nodes. However, by actively accounting for the receiving capacity of downstream intersections and the available roadway storage capacity, the algorithm ensures that all segments can accommodate the remaining queued vehicles. Consequently, although temporary queue accumulation occurs, the system effectively prevents complete traffic blockage or cascading gridlock across the network. Ultimately, a comparative evaluation demonstrates that the proposed approach provides superior traffic clearance performance and more efficient signal utilization compared to the Averaged-Time (AT) model.

Comparative Evaluation of Spectrophotometric and HPLC-PDA Methods for Carotenoid Quantification in Cold Pressed Capsicum annuum Oil

Laksana Charoenchai, Tawanchai Phohom, Bancha Yingngam, Charuwan Thanawiroon — Mon, 29 Jun 2026 00:00:00 +0700

Accurate and validated analytical methods for the measurement of carotenoids in plant oils are needed for quality control, regulatory compliance and product development in the food, nutraceutical, and pharmaceutical industries. In this work, the methods of UV‒Vis spectrophotometry and high-performance liquid chromatography with photodiode array detection (HPLC‒PDA) were evaluated for the quantification of carotenoids in cold-pressed Capsicum annuum oil under harmonized validation conditions. Both techniques were validated according to ICH Q2 (R2) principles, which include predetermined analytical target profiles, risk-based validation criteria and measurement uncertainty estimation. The spectrophotometric approach exhibited good linearity (R²=0.9999),a recovery of 97.66–100.96% and an interday precision of ≤3.34% RSD, indicating its suitability for quick screening of apparent total carotenoids represented as β-carotene equivalents. Greater specificity for β-carotene was obtained with the developed HPLC-PDA method, yielding R² = 0.9992, with 82.75–95.14% recovery and LODs and LOQs of 5.41 and 9.00 µg/mL, respectively. The apparent total carotenoid content was estimated at 161.36 ± 0.83 mg/g oil by spectrophotometric analysis, and a β-carotene concentration of 8.5 mg/g oil was determined by HPLC-PDA measurements. This example demonstrates that the two methods do not measure the same endpoint but rather address different analytical concerns. Overall, the two approaches are complementary: spectrophotometry, as a high-throughput low-cost approach, is good for quality control, whereas HPLC-PDA is suitable when compound-specific identification and regulatory evidence are needed.

A Comparative Analysis of the Viscosity of Three Engine Lubricants for Gasoline Engines Post 10,000 Kilometer Service Interval

Krissadang Sookramoon; Chumpon Patummakason, Benjapa Kaithong — Tue, 30 Jun 2026 00:00:00 +0700

Vehicle maintenance is essential for ensuring efficient operation and extending service life. Engine oil is a crucial component that lubricates various parts of the engine, such as the camshaft, crankshaft, connecting rods, and pistons. It helps reduce friction and dissipates heat generated from engine operation. However, over time, the properties of engine oil gradually change, particularly its viscosity, which may decrease and affect engine performance, potentially leading to mechanical problems. Therefore, studying the changes in engine oil viscosity after prolonged use is vital in determining the appropriate oil change intervals and guiding car owners in proper vehicle maintenance. This study aims to evaluate the changes in kinematic viscosity of three types of gasoline engine oils (SAE 10W-30, SAE 10W-40, and SAE 20W-40) after 10,000 km of operation, based on ASTM D445 standard, and to compare their properties with fresh oil conditions. The analysis showed a clear decrease in viscosity for oil samples used for 10,000 km (second dataset) compared to the fresh oil samples (first dataset), with flow time decreasing from 95 to 66.5 seconds, 105 to 75.6 seconds, and 115 to 82.8 seconds for SAE 10W-30, 10W-40, and 20W-40, respectively. Similarly, the kinematic viscosity dropped from 45.2 to 31.64 cSt, 50.0 to 36.0 cSt, and 55.1 to 39.67 cSt, respectively. A slight reduction in oil density after 10,000 km was also observed. However, the viscosity classifications according to SAE standards at 40°C remained consistent. These results indicate changes in the physical properties of engine oil after use, which may affect lubrication performance and engine protection.