Journal of Applied Research on Science and Technology (JARST)

Strategic environmental assessment of Thai river basins: Incorporating climate change considerations

2023-11-23T14:52:31+07:00

It is globally recognized that climate change is increasingly affecting sustainable development. Given these challenges, it is imperative to incorporate climate change considerations as part of Strategic Environmental Assessment (SEA), a tool used for sustainable development and planning strategies. The Thai government is in the process of developing river basin management schemes and updating SEA for all the river basins in the country. Considering climate change in future development planning processes would ensure that the outcomes enable more sustainable development. In this article, SEA reports for Thai river basins that have been completed were examined to determine if climate change was considered and how it was done. Analyses were conducted for each of the four phases of SEA, i.e., establishing the context for SEA, implementing SEA, informing, and influencing decisions, monitoring and evaluating plans. The checklist criteria were used to analyze climate change impacts in the river basin SEA reports, focusing specifically on climate change or global warming impacts that lead to serious disasters in the river basins. The results showed that 7 out of the 9 reports currently consider climate change impacts, but not in all phases of the SEA. The linkage of climate change impact analyses between the different phases was weak. There were only 4 reports that sufficiently considered climate change impacts in the second phase of the SEA. These reports used both qualitative and quantitative tools that were appropriate for predicting climate change impacts and with a link to the third and fourth phases. As a result, most of the SEA reports were insufficient in considering climate change impacts.

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Preparation of nylon 6/PLA blend nanofibers by needleless electrospinning

2023-11-24T16:50:47+07:00

The nylon 6/PLA blend nanofibers have been prepared for the first time by needleless electrospinning. The formic acid (FA) was found to be the co-solvent with dichloromethane (DCM) at a ratio of 3:1 for dissolving nylon 6/PLA blend. The nylon 6/PLA blend solutions in various ratios of PLA (8, 10, and 12 wt%) were studied to prepare nanofiber at the applied voltage range of 25 kV to 30 kV. The morphology images of the fibers were shown by scanning electron microscope (SEM). It was found that the average diameter of the nylon 6/PLA blend fibers became smaller as the applied voltage increased from 25 kV to 30 kV and as the PLA content increased from 8 to 12 wt%. The morphology of the fibers became finer with increasing the PLA content. The morphology of the nylon 6:PLA (20:10) nanofibers presented a smooth surface without the formation of beads with an average diameter of 157 nm at the applied voltage of 25 kV. The high PLA content (12 wt%) at a low applied voltage (25 kV) exhibited the bead formation. In contrast, the bead was formed at the medium PLA concentration (10 wt%) at the applied voltage of 30 kV. Therefore, the high PLA content (12 wt%) at a high applied voltage (30 kV) presented a ribbon-like nanofiber of nylon 6/PLA without bead formation. The particle size distribution obtained from SEM images of the nylon 6/PLA nanofiber was narrow at low PLA contents and became broader at higher PLA concentrations.

Drowsiness detection using Raspberry Pi for EVs and smart cars

2023-12-08T14:30:58+07:00

Drowsiness detection is highly significant in assuring the safety and effectiveness of intelligent automobiles and electric vehicles (EVs). It used to be that managing driver fatigue was only a question of comfort for contemporary transportation systems. However, with the rapid improvements that have been made in automotive technology and the growing prevalence of autonomous features, this need has developed into a fundamental requirement. Sleepiness detection systems perform the role of watchful co-pilots by continually monitoring the driver's behavior and sounding alerts or taking other appropriate actions when indicators of tiredness are identified. They are an effective strategy to limit the dangerous practice of sleepy driving, which is responsible for many motor vehicle accidents. These accidents are caused by a combination of factors, including fatigue, distraction, and inattention. In the current investigation, a Raspberry Pi is a real-time monitoring system to determine drowsiness. The dataset had one thousand unique images, each depicting a different feature of a real-world driving event. These images have been organized into the following four categories: open eyes (250 images), closed eyes (250 images), open mouth (250 images), and closed mouth (250 images). During this investigation, the experimental circumstances were looked at during daylight and the evening hours. For the system to function correctly, it relies on the Eye Aspect Ratio (EAR) algorithm and the facial landmarks method. The recommended strategy showed a higher degree of accuracy when put into practice. However, the study found that false negative blinks were noticed due to noise that could not be repaired within the collected signal. In the future, we want to concentrate our research efforts on determining whether or not the recommended technique is effective in a broader variety of contexts.

Simulation of flood protection using Hec Ras modeling: A case study of the Lam Phra Phloeng river basin

2024-03-27T11:16:45+07:00

The Lam Phra Phloeng reservoir, positioned within the Lam Phra Phloeng river basin and situated in Nakhon Ratchasimi province, assumes a substantial role in the realm of regional water management. During severe storms in the reservoir's upper region, excess water flows downstream, occasionally resulting in devastating floods in Pak Thongchai district, as witnessed in 2010 and 2020. Both flooding events have resulted in significant economic, social, and livelihood disruptions to the local population in the affected areas. This study pursues two primary objectives: firstly, to assess the extent of flood-prone areas across various return periods (2, 5, 10, 25, 50, 100, and 500 years); secondly, to employ Hec Ras modeling for an in-depth analysis of strategies aimed at flood prevention and mitigation within the Lam Phra Phloeng river basin. The Hec Ras modeling incorporates both 1D and 2D flow simulations. The findings reveal that the flood-prone areas, corresponding to the specified return periods, occupy 0.20%, 1.10%, 1.60%, 2.08%, 2.39%, 2.66%, and 3.17% of the total area in the Lam Phra Phloeng river basin, respectively. To safeguard against flooding and minimize its impact, a multifaceted approach is recommended, encompassing the construction of water barrier flaps, augmentation of water transmission and drainage capacity, implementation of flood alarm systems along the Lam Phra Phloeng river, installation of runoff stations, and the establishment of a comprehensive database system for flood and drought prevention. Among these measures, constructing water barrier flaps and enhancing water transmission and drainage capabilities stand out as effective strategies to protect the Lam Phra Phloeng river basin from flooding.

Fermentation of bamboo shoots using mature coconut water and its stability during storage at different conditions

2024-03-11T11:45:01+07:00

Fermented-bamboo-shoots are a common raw ingredient used in several Thai local dishes. However, contamination of harmful and undesirable microorganisms in the fermented bamboo shoots has been reported due to improper and long fermentation processes. Mature coconut water (MCW) could shorten the bamboo shoot fermentation process and improve the product quality. This study aimed to develop fermented bamboo shoots using mature coconut water and determine their stability during storage in different conditions. Bamboo shoots from Prachinburi province were mixed with 25 g/kg of Kosher salt and fermented with MCW to obtain fermented bamboo shoots with coconut water (FBSC) at room temperature. Traditional fermented bamboo shoots (TFBS), prepared using 100 g/kg of Kosher salt, were used as a control. After fermentation, the samples were packed in polypropylene (PP) or polyethylene terephthalate (PET) bags and stored at different temperatures for 60 days. The number of bacteria, pH, and total acidity (TA) were determined during fermentation and storage, as well as the color changes of the shoots. The results indicated that in the fermentation process, MCM with low salt concentration could effectively increase the number of lactic acid bacteria (LAB) greater than the traditional method. The number of LAB in FBSC was 9.78±0.43 CFU/mL of LAB, while TFBS had 8.08±0.02 log CFU/mL. Lower pH was significantly found in FBSC (3.89±0.01) than in TFBS (4.00±0.01), while TA of FBSC was significantly higher than that of TFBS, which were 11.25±0.01 g/L and 6.00±0.01 g/L, respectively. During storage, it was found that fermentation methods, types of packaging, and storage temperatures significantly affect the shoot colors but not pH and TA. PET bags could better delay the browning reaction of the fermented shoots than PP bags. The higher storage temperatures were, the faster color changes were observed. This study indicated that MCW could be used as fermentation media for bamboo shoots.

Combining vehicle routing and bin packing problem for vehicle routing planning: A case study of a chemical factory

2024-04-24T15:56:54+07:00

In the logistics distribution process, effective transportation management is required to ensure quality and timely delivery. In addition, transportation must be more economical and faster. The case study company is a chemical plant, an industrial company that produces products for hygiene and cleaning. The delivery manager plans the transportation routes based only on her experience because no decision-making aids are available. In addition, the manager considers the shipping order from first to last when arranging the products on the transportation vehicles. The goods for the final delivery location are placed at the back and bottom of the delivery truck. This cannot guarantee that the transportation routes set by the manager are suitable. Therefore, this study aims to plan delivery routes, arrange items in trucks, and reduce transportation costs for a case study of a chemical factory by using vehicle route problems and container filling problems. Then, the program is developed in Python using the Saving Algorithm, the 3D First Fit Decreasing Algorithm, and the 3D Best Fit Algorithm. The results show that the program method can reduce the use of transportation vehicles from 19 to 14, which is 26.32%; reduce the total distance from 5,499.8 kilometers to 3,406.92 kilometers, which is 38.05%; reduce the wages of transportation vehicles from 36,666 to 24,993 baht, which is 31.84%; can increase the average total weight per vehicle from 961.22 to 1,319.71 kilograms, which is 37.30%; and increase the average space utilization per vehicle from 37.93% to 51.47%, which is 13.54%. This method can reduce costs and increase efficiency for the company. Finally, the developed program also supports inexperienced operations managers in making decisions when planning transportation routes and loading goods, Thereby saving working time.

All solutions of the Diophantine equation 1/x+1/y+1/z=u/(u+2)

2024-07-08T10:56:30+07:00

In the history of mathematics, many mathematical researchers have investigated the Diophantine equation in the form , where and are positive integers. Without loss of generality, we may assume that . This Diophantine equation, also known as the Egyptian fraction equation of length 3, is to write the fraction as a sum of three fractions with the numerator being one and the denominators being different positive integers. Examples of research such as, in 2021, Sandor and Atanassov studied and found that the Diophantine equation has forty-four positive integer solutions. In this paper, we will study and find the complete positive integer solutions of the Diophantine equation , by using elementary methods of number theory and computer calculations. In the process, we can see that . Then, we will consider separately the value of a positive integer in nine cases. The first case is impossible. For the second and third cases, we will separate to consider the value of . For the remaining cases, we will separate to consider the value of . The research results showed that all positive integer solutions of the Diophantine equation are eighty-seven positive integer solutions. Moreover, from the steps to find the above positive integer solutions, we expect that it can be used to find the complete positive integer solutions of the Diophantine equation , where is a positive integer with .

Mobile random text-based voice authentication for older adults: A pilot study

2024-05-17T10:50:36+07:00

Thai older adults often struggle to use existing smartphone authentication systems due to age-related problems. Random text-based voice authentication, which resists Replay attacks and reduces the need to memorize information, is a suitable alternative. Nevertheless, past studies have insufficiently focused on usability, leading this research effort to improve the usability of voice authentication for older adults. As part of the research, this study seeks to develop a random text-based voice authentication suitable for older adults. The prototype was implemented as a mobile application, VAuth, with Voice User Interface (VUI) as a primary interaction method. Formative Usability Testing was conducted iteratively and incrementally to evaluate and refine VAuth. The first version of VAuth was well-received despite initial problems, which were resolved subsequently. Overall results indicated that VAuth is usable for older adults. Participants could complete all given tasks (enrollment and verification) through VUIs. They responded favorably to VUIs in general and acknowledged their advantages. Moreover, the results from the SEQ and SUS questionnaires aligned with participants' positive opinions. The dialogue design was adequate, and older adults could correctly pronounce Thai-word passphrases in most cases. While the accuracy of Thai speech recognition remains an issue, progress in voice recognition may eventually overcome it. Despite these encouraging results, this study still has limitations. While the test helped determine if VAuth is a viable solution, it did not confirm whether VAuth remains usable when deployed in larger, different contexts, such as a noisy environment or public places. Thus, further studies are needed to compare VAuth with existing authentication methods with an enlarged sample size in multiple usage scenarios.