Journal of Applied Research on Science and Technology (JARST)

Water pollution influencing contamination of Vibrio bacteria in the coastal aquaculture area of Chanthaburi and Trat Provinces

2024-04-26T11:00:04+07:00

Since 1982, the Eastern coastal area of Thailand has been developed from the Eastern Seaboard Project (ESP) to the Eastern Economic Corridor (EEC). The marine ecosystem of Chanthaburi and Trat Provinces was polluted by anthropogenic activities such as agriculture, transportation, tourism, fisheries, and urban communities. This study aims to investigate the marine environmental quality and the contamination of the Vibrio bacteria (V. cholerae, V. parahaemolyticus and V. vulnificus) in the coastal aquaculture area of Chantaburi and Trat Provinces. Environmental sampling areas were designated at seven stations eastward from Tamai to Klongyai districts (about 150 km long stretch). The physicochemical parameters, including temperature, salinity, conductivity, pH, dissolved oxygen (DO), NH₃, and major anions e.g. NO₂^-, PO₄^3- of seawater samples were measured at designated stations. Marine samples, including cockles (Anadara granosa), mussels (Perna viridis), oysters (Saccostrea cucullata) and white shrimp (Litopenaeus vannamei) were collected from aquaculture areas located in the estuarine ecosystem with simple random sampling. Our studies revealed that major inorganic substance concentrations followed this consequence order PO₄^3- > NH₃>NO₂^-. The physicochemical properties indicated that seawater quality has been varied within the marine quality standard class III for aquaculture. The prevalence of V. parahaemolyticus and V. vulnificus showed in all bivalve samples were detected at 0.36 to 4.30 MPN/g and below the detection limit (0.3 MPN/g), respectively, whereas V. cholerae was not detected. This study also concluded that the periods of environmental sampling did not significantly influence the seawater quality and the level of Vibrio contamination. However, the difference of infection rates for V. parahaemolyticus and V. vulnificus depended on the marine species.

Enhancing torrefaction process efficiency for biochar production from filter cake residue in the sugar industry

2024-05-20T11:31:49+07:00

The torrefaction process is a promising technique for enhancing the quality of solid biomass fuels. This study investigates the effects of torrefaction on biochar produced from filter cake residue, a byproduct of the sugar industry. The primary objectives were to evaluate the impact of process parameters on biochar properties and identify optimal conditions for maximizing the higher heating value (HHV). Filter cake residue was subjected to torrefaction at temperatures ranging from 220-340°C under an inert atmosphere. The influence of particle size (20, 60, and 100 mesh), nitrogen flow rate (20-30 ml/min), temperature (220-340°C), and residence time (30-90 min) on biochar properties was examined using response surface methodology. Proximate analysis revealed that torrefaction significantly reduced moisture, volatile matter, and ash content while increasing fixed carbon content. The maximum HHV of 21.9571 MJ/kg was achieved at a particle size of 20 mesh, nitrogen flow rate of 25 ml/min, temperature of 340°C, and residence time of 60 min. The experimental results agreed with predicted values from the developed models, with an average error of 3.64%. Optimal torrefaction conditions were determined to be a particle size of 21.77 mesh, nitrogen flow rate of 22.50 ml/min, temperature of 311.13°C, and residence time of 42.58 min, yielding a maximum HHV of 18.4853 MJ/kg. These findings demonstrate the potential of torrefaction for upgrading filter cake residue into a high-quality solid biofuel, providing a sustainable solution for waste utilization in the sugar industry.

The development of real-time energy monitoring system using IoT base

2024-06-05T11:21:31+07:00

This paper aims to develop a real-time energy monitoring system based on smart metering to enhance energy efficiency in the single-phase residential sector. Based on the concept of low-cost IoT devices, this intelligent meter system is designed to monitor household energy consumption. It provides real-time information on a graphical Node-RED Dashboard, making it easy for households to track and manage their energy usage. The hardware of the power metering system included the Node MCU ESP8266, the PZEM-004T, and a cloud server built on the Raspberry Pi for storing electricity consumption data by using Node-RED to connect devices via an application programming interface system. This system can help analyze the electricity consumption behavior in the residential sector. It is a guideline for selecting the electricity rate between the TOD and TOU rates. The results found that in the electrical energy measurements of households 1 and 2, the mean deviations were 0.8758% and 0.5523%, respectively. The electricity cost-saving results when changing the electricity tariff from the TOD rate of households 1 and 2 to the TOU rate. It was found that electricity costs can be saved by 0.2807% and 1.0936%, respectively. The most critical variable is electricity consumption during peak periods. In the case study of household 1, if the electricity consumption during the peak period is less than 13%, it will be appropriate to select the Time of Use rate. In household 2, if there is electricity consumption during the peak period, less than 38% would be appropriate to choose the type of electricity user with a TOU rate.

A study on the behavior of pulling power and flammability of mold walls mixed with high-density polyethylene plastic waste

2024-07-10T11:15:05+07:00

Currently, materials used in construction have been continuously developed in terms of quality and efficiency, especially fiber reinforcement in mortar, a form of development used in construction. The development aims to enhance concrete's tensile properties and performance for higher flexibility. Most plaster walls are ordinary mortar and have low elasticity, which is a weak point. Therefore, attempts are being made to improve their properties by using a rigid material as a concrete mixture, namely high-density polyethylene plastic, to increase its ability to bear tensile force. This study examines the tensile strength and flammability tests of walls plastered with mortar, with which high-density polyethylene plastic waste is mixed. The tensile strength of mortar plaster walls mixed with high-density polyethylene plastic is tested by replacing at 2.5%, 5%, and 10% proportions and cured at 7, 14, and 28 days. By comparing general mortar and high-density polyethylene plastic mortar, it is found that the general mortar had the highest tensile strength at 28 days of curing. The obtained value is 45 ksc, and the mortar mixed with polyethylene plastic in the amount of 2.5% at 28 days of curing can withstand the strength of 45 ksc. In addition, the general mortar can produce the same tensile strength as mortar mixed with high-density polyethylene plastic. The flammability test shows that general mortar develops red marks after being burned with fire, while the mortar combined with high-density polyethylene plastic develops black marks. However, neither type of wall is in flames nor spread.

The fabrication of wood alternative material from cassava rhizome and cassava peel pulp

2024-07-23T15:49:22+07:00

The increasing demand for wood alternative material in construction and furniture. Corresponds to global efforts to reduce pressure on forests, necessitating the exploration of alternative materials to wood. The agricultural industry can not only supply raw materials from non-wood plants but also waste material and byproducts. The aim of this research was to explore and manufacture wood alternatives using cassava rhizomes and cassava peels, thereby valorizing agricultural waste. The research methodology involved blending milled rhizomes and cassava peels with urea-formaldehyde resin followed by a hot-pressing process to form the final product. The samples size for this study was 450x450x10 mm were made using 6-10 percent urea-formaldehyde resin by weight of the composite materials aiming to achieve a sheet density about 600 kg/cu-m. Three distinct ratios of Cassava rhizome to cassava peel pulp were examined as potential wood substitutes. All test results of sample were compared with the industrial standards outlined in Thai Industrial Standard. The study found that wood substitutes created from Cassava rhizome and Cassava peel pulp combined with urea-formaldehyde resin could meet the set standards. Cassava rhizome improves important properties like density, moisture content, thickness swelling, formaldehyde content, modulus of rupture, and modulus of elasticity according to TIS 876-2547 standards. However, adding peel pulp tends to reduce these qualities. There is no significant change in the density of the wood-alternative materials. However, a 10% urea formaldehyde content improves the mechanical properties. The study found that wood substitutes created from Cassava rhizome and Cassava peel pulp combined with urea-formaldehyde resin could meet the set standards. Moreover, the production cost of these wood substitute materials was lower than the prevailing market prices. This study disseminates knowledge from research that utilizes cassava rhizomes and peels to create sheet like wood substitute materials. Using modern methods and appropriate technologies, cassava rhizomes and peels can be transformed into a diverse range of wood substitute products, and capable of effectively competing with wood and other materials in the future.

Phytochemical screening and toxicity assessment of compounds isolated from the leaves of Mangifera indica L. for the control of Spodoptera litura (Lepidoptera; Noctuidae)

2024-09-04T10:04:22+07:00

This study aimed to analyze the phytochemical composition and antioxidative capabilities of mango leaves (Mangifera indica L., Nam Dok Mai), indigenous to Sa Kaeo Province, Thailand. Various solvents with differing polarities, including n-hexane, DCM, ethyl acetate, and MeOH, were utilized for leaf extraction. The findings revealed the existence of eight groups of phytochemical compounds: alkaloids, flavonoids, coumarins, saponins, tannins, terpenoids, steroids, and cardiac glycosides. The MeOH crude extract exhibited the highest concentration of total phenolic compounds at 409.88 ±0.02 mg GAE/g. Furthermore, the MeOH crude extract demonstrated the strongest antioxidant activity, with an IC₅₀ value of 0.52 ±0.02 μg/ml, as determined by the DPPH method. High-performance liquid chromatography (HPLC) was employed to identify gallic acid and mangiferin in the MeOH crude extract. Laboratory tests were conducted using the topical application method to evaluate the toxicity of the M. indica leaf crude extract on 2nd instar Spodoptera litura larvae. The MeOH crude extract exhibited high efficacy, with an LD₅₀ value of 10.58 µg per larvae within 24 hours. Gallic acid and mangiferin were identified as the primary active ingredients, with LCD₅₀ values of 1.19 µg per larvae and 1.90 µg per larvae, respectively, within 24 hours. Additionally, the impact on detoxification enzymes (24 hours post-treatment) was assessed in surviving 2nd instar S. litura larvae using the topical application method. The MeOH extract treatment resulted in 1.31-fold inhibition of carboxylesterase (CE), 1.31-fold inhibition of glutathione-S-transferase (GST), and 1.32-fold inhibition of acetylcholinesterase (AChE).

Synthesis of biocompatible hydroxyapatite from quail eggshell, oyster shell, and periwinkle snail shell

2024-09-27T11:11:39+07:00

This study focuses on the synthesis of hydroxyapatite (HA, Ca₁₀(PO₄)₆(OH)₂) from calcium carbonate (CaCO₃)-rich quail eggshells, oyster shells, and periwinkle snail shells (Filopaludina bengalensis) through the use of the wet precipitation method. The methodology involved calcining the shell waste to convert CaCO₃ to calcium oxide (CaO), undergoing hydration, and reacting with phosphoric acid (H₃PO₄) to synthesize HA. The results indicated that periwinkle snail shells had the highest percent yield of HA at 92.12%, followed closely by quail eggshells at 92.01%, and oyster shells at 73.65%. For producing CaO, oyster shells provided the highest percent yield of CaO at 103.72%, followed by quail eggshells at 98.6% and periwinkle snail shells at 92.09%. The synthesized HA exhibited high biocompatibility, which is crucial for its potential applications in medical fields such as bone replacement and regeneration. The X-ray diffraction (XRD) analysis confirmed the successful synthesis of high-quality HA, with characteristic peaks indicative of excellent crystallinity and purity and near identicality to the standard XRD pattern of HA of ICDD 9-432 and the XRD pattern of successfully synthesized HA in other studies, indicating high biocompatibility. The research highlights the potential of recycling food waste, specifically shell waste, into valuable biomaterials. This not only addresses environmental concerns but also supports sustainable practices in the food industry. Moreover, the study contributes to advancements in biomaterials for medical applications, emphasizing the viability of utilizing organic waste for high-value products. By transforming food waste into useful medical materials, this research offers promising solutions for waste management and resource utilization, particularly within Thailand's ecological and industrial framework.

Characterization and bioactive protein hydrolysates from two-spotted cricket (Gryllus bimaculatus De Geer) and short-tail cricket (Brachytrupes portentosus Lichtenstein)

2024-08-23T10:30:12+07:00

The two-spotted cricket (Gryllus bimaculatus) and short-tail cricket (Brachytrupes portentosus) are economically significant edible insects in Thailand, boasting up to 60% protein content. This study investigates the effects of different types of proteases on the production of protein hydrolysates and biological activities from two cricket species, divided into 4 groups based on extraction and digestion methods as proteins extracted by heat at 100°C, proteins digested with the protease SD-AY 10, pepsin, and a combination of protease SD-AY 10 and pepsin. None of the 4 protein groups inhibited pathogenic E. coli, Salmonella enteritidis, and Salmonella typhimurium. The total antioxidant capacity (TAC) assessment showed that proteins from G. bimaculatus digested with SD-AY 10 had a significantly higher antioxidant level (5.5 nmol/µl), while proteins from B. portentosus digested with pepsin had a similarly high antioxidant level (5.59 nmol/µl), both significantly higher than other groups (p<0.05). Proteins from both crickets digested by enzymes were safe for RAW 246.7 macrophage cells at concentrations from 1.56 to 25% (v/v) and effectively inhibited nitric oxide production. Protein hydrolysates from G. bimaculatus and B. portentosus inhibited nitric oxide production at a concentration of 25% (v/v) equivalent to ß-glucan. Phagocytic activity was also observed in protein hydrolysates from both cricket species, stimulating RAW 246.7 cells at concentrations of 1.56-25% (v/v). However, protein hydrolysate from B. portentosus, digested with pepsin at a concentration of 1.56-12.5% (v/v) showed higher phagocytic activity values (152.52-163.86%) compared to ß-glucan (149.18%). The results showed that protein hydrolysates from two cricket species, digested by enzymes, exhibited antioxidant activity, inhibited nitric oxide production, are safe for cells, and hold potential as future supplements for human food and animal feed additives.