During the recent years, PM2.5 concentration is rising above the safety exposure limit in Thailand. PM2.5 could have originated from various sources such as exhaust fumes, open air burning, wildfire, etc. This concludes that all cities or places would have different PM source contributions. Most studies regarding the PM source findings were done based on chemical analysis. Our research team would like to predict the PM sources physically by nanostructures analysis. These methods would require the PM dust to be collected in a limited amount of time and dry. The use of paper filters may cause contamination from filter material which may cause errors in result evaluation. Our team suggests using Electrostatic Precipitator (ESP) where electrostatics is used to capture PM dust. This research mainly focuses on designing and building the ESP system for PM collection whereas the requirement is to collect at least 100 mg of PM dust within 1 day which would be adequate for nanostructure analysis. The study revealed that the customized ESP system could achieve of up to 80% collecting efficiency (which is more than the commercial ESP that we previously used), there’s a also a parametric study of relationships between flow velocity and collecting efficiency where collecting efficiency is inversely proportional to flow velocity. The suggested air velocity is not to exceed 2 m/s. However, there’re still more room for improvement of the ESP system for PM collection such as the convenience of PM collection process which resulted from the ESP construction geometry and sizes.
มลพิษทางอากาศนั้นส่งผลกระทบโดยตรงต่อสิ่งแวดล้อมและสุขภาพของสิ่งมีชีวิตทั้งในระยะสั้นและระยะยาว มลพิษทางอากาศนั้นสามารถจำแนกได้เป็นหลายกลุ่ม นั่นคือ มลพิษในรูปแบบสถานะแก๊ส ได้แก่ แก๊สโอโซน แก๊สไนโตรเจนออกไซค์ เป็นต้น และ มลพิษในรูปแบบของแข็ง ได้แก่ ฝุ่นละอองต่างๆ ซึ่งจะถูกจำแนกด้วยขนาดเป็นหลัก ในที่นี้ ฝุ่นละอองขนาดเล็ก (Particulate Matter) ตัวย่อ “PM” จะเป็นประเด็นสำคัญของงานวิจัยนี้เนื่องด้วยในปัจจุบัน สถานการณ์ฝุ่น PM2.5 ใน ประเทศไทยโดยเฉพาะภาคกลางและภาคเหนือ มีแนวโน้มที่จะรุนแรงขึ้นในฤดูหนาวของทุกปี
คณะเทคโนโลยีการเกษตร
Threadfin breams is an economically important fish that can be found in fisheries in both the Gulf of Thailand and Andaman Sea and is cheap. In addition, the consumption of raw fish as sashimi is increasingly popular in Thailand. Therefore, it is necessary to promote its consumption to increase its value. This study investigated the preservation of threadfin breams (N. furcosus) for raw or sashimi consumption. The preservation of threadfin breams consisted of Ikejime (K) and cold seawater (S) methods, and the preservation of the fish by Gutting (G) and whole (W) and storing for 3 days on ice (I) or in a refrigerator (F). The freshness quality of threadfin breams was evaluated by sensory, physicochemical (TVB-N, TMA-N and pH), freshness index (Ki-value) and microbiological methods. It was found that after being stored for 3 days, the KGF group of threadfin breams had the highest overall sensory score, which was 8.36±0.80 points, and the KWI, SWI and SWF groups of threadfin breams had the lowest overall sensory scores, which were 8.13±0.77, 8.13±0.77 and 8.13±0.81 points, respectively. And the overall sensory scores of all experimental groups of fish increased significantly (p<0.05). The TVB-N value of threadfin breams in KGF group had the lowest TVB-N value, which was 1.37±0.93 mg nitrogen/100 g sample. The threadfin breams in SGI group had the highest TVB-N value, which was 2.36±1.15 mg nitrogen/100 g sample. The TVB-N of fish in all experimental groups increased significantly (p<0.05). The TMA-N value of threadfin breams in KGF group had the lowest TMA-N value, which was 1.56±0.88 mg nitrogen/100 g sample. The threadfin breams in SWF group had the highest TMA-N value, which was 2.17±1.22 mg nitrogen/100 g sample. The TMA-N of fish in all experimental groups increased significantly (p<0.05). The pH value of threadfin breams in KGF group had the lowest pH value, which was 6.40±0.12. The threadfin breams in SWF group had the highest pH value, which was 6.78±0.25. The pH of fish in all experimental groups increased significantly (p<0.05). Ki value The threadfin breams in KGF group had the lowest Ki value, which was 9.05±0.73%. The threadfin breams in KWI group had the highest Ki value, which was 12.88±4.19%. The Ki value of all experimental groups of fish increased without statistical significance (p>0.05). In terms of freshness quality in microbiology, it was found that in all experimental groups, Salmonella spp., S. aureus, B. cereus, C. perfringens and E. coli were found in all experimental groups of threadfin breams. All types of microorganisms in all groups of threadfin breams increased with statistical significance (p<0.05). When compared with the freshness quality criteria in terms of sensory, chemical, physical, freshness index and microbiology, it was found that all groups of threadfin breams were very fresh and suitable for raw consumption during the preservation and storage for 3 days. After 3 days of storage, the threadfin breams should be consumed cooked because the freshness quality of the fish is not suitable for raw consumption due to the increase in various parameters. The increase in various parameters is due to the deterioration of the fish and the activities of microorganisms. Therefore, threadfin breams is suitable to promote raw consumption within 3 days of storage. In addition, fish preservation, especially by Ikejime method, then cutting open the belly and storing in the refrigerator, can help improve the freshness of the fish. The results of this study can be used to develop techniques for preserving fish after capture for fishermen and can promote the increase in the value of threadfin breams in the future.
คณะเทคโนโลยีการเกษตร
Climate change affects agricultural systems worldwide, including Thailand, and may lead to reduced crop yields, impacting food security. Bambara groundnut is a crop with the potential to adapt to changing environments and can thrive in areas with limited resources. This research aims to study the impact of climate change on Bambara groundnut yields in Thailand using the DSSAT (Decision Support System for Agrotechnology Transfer) model, an important tool for predicting plant growth under various environmental conditions. This study utilizes climate data, soil composition, and genetic information of Bambara groundnut to simulate and analyze yield trends under future climate scenarios. Four study areas in Thailand were selected: Songkhla, Lampang, Yasothon, and Saraburi. The CSM-CROPGRO-Bambara groundnut model was used to assess the impact of changing temperature and rainfall on the growth and yield of Bambara groundnut. The results of this study are expected to provide farmers and researchers with valuable information for planning cultivation and managing peanut production in response to climate change. Additionally, the findings can help formulate policy guidelines to promote the cultivation of climate-resilient crops and support the country's food security.
คณะวิศวกรรมศาสตร์
This research aims to investigate the adulteration of Khao Dawk Mali 105 rice based on storage age using Near-Infrared Spectroscopy (NIRS) with Fourier Transform Near-Infrared Spectroscopy (FT-NIR) in the wavenumber range of 12,500 – 4,000 cm-1 (800 – 2,500 nm). Storage duration significantly impacts the quality of cooked rice. This research is divided into two parts: 1) to investigate the feasibility of separating rice according to storage age (1, 2, and 3 years) using the best model created by an Ensemble method combined with Second Derivative, which achieved an accuracy of 96.3%. 2) To investigate adulteration based on storage age by adulterating at 0% (all 2- and 3-year-old rice), 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% (all 1-year-old rice). The best model was created using Gaussian Process Regression (GPR) combined with Smoothing + Multiplicative Scatter Correction (MSC), with coefficients of determination (r²), root mean square error of prediction (RMSEP), bias, and prediction ability (RPD) values of 0.92, 8.6%, 0.9%, and 3.6 respectively. This demonstrates that the adulteration model can be applied to separate rice by storage age (1, 2, and 3 years). Additionally, the color values of rice with different storage ages show differences in L* and b* values.