Burapha Science Journal

Editorial Note

2024-04-19T08:58:47+07:00

Reading-Based Voice Authentication on a Smartphone: A Case Study of Older Adults

2024-01-04T13:25:31+07:00

Background and Objectives : Authentication is a vital component of smartphones to protect devices from unauthorized access. Nevertheless, existing schemes are unsuitable for elderly users due to their age-related difficulties. As a result, many older adults employ insecure practices, including disabling device authentication systems. One promising solution is voice authentication, which has been consistently suggested as a more usable option for older adults. However, voice authentication has a drawback regarding vulnerability to an imitation or recording of an enrolled speaker. Among many solutions for this issue, reading-based voice authentication is relatively simple and theoretically usable for older adults. Still, there is insufficient information to confirm the possibility, including older adults' perceptions and the reactions of Thai subjects toward the system. Therefore, this research intends to confirm that possibility and find whether reading-based voice authentication is usable enough for older adults.

Methodology : Three different styles of reading-based voice authentication were developed, and the testing was conducted to evaluate their usability relative to older adults. Participants were divided into three groups for each authentication style. Then, they would use the systems by enrolling and verifying themselves, where the researcher observed their actions and noted their opinions, along with the systems' performance metrics (Success Rate, Task Time, Error).

Main Results : The results of the test were encouraging. In terms of performance, all three styles achieved high task completion rates; almost all participants successfully enrolled in the system and verified themselves. There were significant differences regarding the time needed to complete enrollment. Nonetheless, the verification process used the same amount of time on average. Most errors occurred during the manual voice recording, where participants either forgot to press a button or pressed at the wrong moment. Both the scores from SEQ and SUS questionnaires indicated that all three styles of reading-based voice authentication were easy to use. The statistical tests to compare the results of all three authentication styles indicated that they were comparably usable, and mechanisms, like random passphrases, could be employed without adverse effects on usability. However, the ability to freely choose a passphrase negatively impacts usability as it requires text input and is thus unsuitable for older adults. Most participants expressed positive thoughts about reading-based voice authentication, like the ease of use and convenience.

Conclusions : Despite the promising results, this research still has limitations. The number of participants was smaller than intended, which affected the study's statistical power. Furthermore, this research needs more experiments to compare reading-based voice authentication with other authentication methods, assess its security aspect, and test the system in other settings, such as outdoor locations.

Design and Performance Evaluation of Vegetable Shredder

2024-01-04T14:07:52+07:00

Background and Objectives :Vegetable shredders were generally designed to be used to reduce the size of agricultural products. The design and development of vegetable shredder to get a beautiful shapes and quality suitable for further process in healthy products is still lacking knowledge. Therefore, this research was aimed to design and build a vegetable shredder and study the effect of rotational speed on the efficiency of the shredder.

Methodology : Study and calculate the important values for the main component of vegetable shredder. Then, five types of vegetables used to test the shredder performance were potato, carrot, radish, cucumber and onion with the rotational speeds of the inverter included 500, 600, 700 and 800 rpm. The loss percentage, the percentage passing the required quality criteria and the production capacity of vegetable shredder were determined.

Main Results : The vegetable shredder has the following main components: machine structure, blade plate, blade plate cover, raw material input slot, 0.5 hp electric motor and inverter (rotational speed device). The result showed that the loss percentage from the shredder’s operation under various conditions was 5.28%±0.84 - 19.15%±1.89, and the different types of vegetables used different rotational speeds. The suitable rotational speed with a high percentage passing the required quality criteria in potato, carrot and onion was at 700 rpm, while the rotational speed at 600 and 800 rpm were suitable with radish and cucumber, respectively. In addition, the vegetable shredder had a significantly higher production capacity than the manpower to cut vegetables (p<0.05).

Conclusions : To save production costs and get high-quality products or high percentage pass the required quality criteria, the vegetable shredder designed and built in this research was suitable for chopping vegetables with good shapes and homogeneous textures, such as potatoes, carrots and radishes.

Dynamic Mathematical Models of Mineral Water Production for Community Consumption

2024-01-05T09:43:31+07:00

Background and Objectives : The objective of this study was to develop the dynamic modeling of Recirculation Ring Plug-Flow Reactor (RRPFR) and Recirculation Ring Completely-Mixed Stirred Tank Reactor (RRCSTR) of a Recirculation Ring Drown Flow Filter Reactor of Groundwater (RRFRG).

Methodology :The flow direction is perpendicular to the Recirculation Ring Drown Flow-cylindrical reactor. The inflow into the iron reactor diameter 0.15 m., height 4 m., connected to the second resin reactor, diameter 0.15 m., height 1.2 meters of 12 reactors had a diameter to length ratio (D:L) (<1:4)

Main Results :It was found that the ratio (R) was 3 with the background concentration iron (Fe*) and the background concentration hardness (CaCO3*) were 0.071 and 0.032 mg/L. The hydraulic retention time (HRT) at 0.09 day was the highest efficiency to remove Fe and CaCO3 were 99.867% % and 99.996 % in groundwater.

Conclusions : The development of the mathematical model, it was found that second-order reaction occurred in Recirculation Ring Completely-Mixed Stirred Tank Reactor (RRCSTR) with a coefficient of constant k_2nd were 3396.80 1/day and 11091 1/day.

Application of Benthic Fauna as Bioindicators for Water Quality Assessment : A Case Study of Bang Ban Canal, Ayutthaya Province

2024-01-05T10:34:04+07:00

Background and Objectives : The objective of this study was to observe the benthic fauna diversity and application of the biotic indices, BMWP^thaiscore (Biological Monitoring Working Party) and ASTP^thai (Average Score Per Taxa) to assess the water quality of the Bang Ban canal, Ayutthaya Province.

Methodology : Benthic samples were collected from four sampling stations throughout the canal course in June 2020 (dry season), July-August 2020 (early rainy season) and September 2020 (late rainy season), using an Ekman grab. Water depth, transparency, temperature, pH, dissolved oxygen, conductivity and total dissolved solids were recorded in situ at each station, and sediment samples were taken for grain size analysis and organic matter assessment in a laboratory.

Main Results : A total of 19 species belonging to 17 genera, in 13 families of benthic fauna were found. The dominant macrofauna in the area, including aquatic oligochaetes families Tubificidae (Branchiura sp. and Tubifex sp.) and Naididae (Dero sp.), polychaetes families Nepthyidae (Nepthys sp.) and Nereididae (Namalycastis sp., Nereis sp. and Dendronereis sp.), gastropods family Viviparidae (Mekongia swainsoni brueri), bivalves family Corbiculidae (Corbicula sp.), crustacean family Palaemonidae (Macrobrachium sp.), and insect larvae family Chironomidae (Chironomus sp.) were discovered. According to the result of the biological indices, BMWP^thai score and ASPT^thai, Bang Ban canal indicated poor water quality depending on the standard criteria of surface water quality category 4 (poor water quality).

Conclusions : The study concluded that the BMWP^thai score and ASPT^thai can be used to assess water quality, with relationships to the number of families, density, richness index, diversity index, and evenness index.

Effect of Different Concentration of Plant Growth Regulators on In Vitro Culture of Kaempferia sisaketensis Picheans.& Koonterm

2024-01-05T10:56:29+07:00

Background and Objectives : This research studied a propagation protocol of Kaempferia sisaketensis Picheans. & Koonterm which is a rare and endemic plant of The Northeast of Thailand using plant tissue culture techniques.

Methodology : Microshoot (1 cm long) of K. sisaketensis were cultured on Murashige and Skoog medium (MS) supplemented with various concentrations of cytokinins (BA, kinetin, and TDZ) and auxin (NAA) for eight weeks. Transferring complete plantlets of K. sisaketensis to pots containing soil, sand and soil:sand (1:1) under greenhouse conditions for eight weeks.

Main Results : The results show that culturing the microshoot of K. sisaketensis on MS medium supplemented with 1 mg/l kinetin produced the highest number of shoots, which is 5.30 shoots/explant. For root induction, the results show that the highest number of roots were 14.50 roots/explant when microshoots of K. sisaketensis was cultured on MS medium augmented with 2 mg/l kinetin and 1 mg/l NAA. After transferring complete plantlets of K. sisaketensis to pots containing different types of planting materials under greenhouse conditions for eight weeks, the best survival rate was 100% when transplanting to sand.

Conclusions : This research is the first report on tissue culture of K. sisaketensis. This study can be used to propagate and preserve K. sisaketensis from extinction.

The Simplified Synthesis of Co0.6Zn0.4Fe1.7 Mn0.3O4 Magnetic Nanopowders with High Magnetization by Solid-State Combustion Technique

2024-01-05T13:20:28+07:00

Background and Objectives : The aim of this work, the simplified synthesis of magnetic crystal powder Co_0.6Zn_0.4Fe_1.7Mn_0.3O₄ (CZFMO) via solid-state combustion techniques was studied

Methodology : The simplified synthesis of magnetic crystal powder Co_0.6Zn_0.4Fe_1.7Mn_0.3O₄ (CZFMO) via solid-state combustion technique was prepared by using glycine as fuel, and raw materials with nitrate compounds. The molar ratio of the fuel to the raw materials was 1:4.27, and calcined temperatures were in the range of 500–800^oC.

Main Results : It was found that the CZFMO powders with a calcined temperature between 500 and 800^oC for 2 h showed a pure spinel structure with a cubic structure, which corresponded to JCPDS no. 221086. The particles of the CZFMO powders at a calcined temperature of 500–800^oC for 2 h exhibited an agglomerated form. The average particle size increased from 70 to 150 nm when the calcination temperature increased. The magnetic properties of CZFMO powders calcined at temperatures of 500–800^oC for 2 h showed soft ferromagnetic properties in all samples. The values of magnetization (M_s), remnant magnetization (M_r), and coercive field (H_c) were in the range of 67.60–116.64 emu/g, 14.50–33.50 emu/g, and 7.30–26.45 Oe, respectively.

Conclusions : At a calcined temperature of 750^oC, the CMZFO powder exhibited the highest values of M_s, M_r, and H_c at 116.64 emu/g, 33.5 emu/g, and 26.45 Oe, respectively.

The Preparation of (Bi0.5Na0.5)0.94 (Ba0.945Ca0.055)0.06(Ti0.9946Sn0.0054)O3 :Y2.7Bi0.3Fe4.7Mn0.3O12 Composite Ceramics with Multiferroic Properties Via Solid-State Combustion Technique

2024-01-05T14:02:49+07:00

Background and Objectives : This research focuses on the preparation of ceramic composites with multiferroic properties of (Bi_0.5Na_0.5)_0.9₄(Ba_0.945Ca_0.055)_0.0₆(Ti_(0.9946)Sn_0.0054)O₃(BNT-BCTS) with mixing Y_2.7Bi_0.3Fe_4.7Mn_0.3O₁₂ (YBFM) at various ratios by solid-state combustion technique. The effect of ratios on phase structure, microstructure, electrical properties, and magnetic properties of the prepared ceramic composites were studied.

Methodology : The ceramic composite of (Bi_0.5Na_0.5)_0.9₄(Ba_0.945Ca_0.055)_0.0₆(Ti_(0.9946)Sn_0.0054)O₃(BNT-BCTS) with mixing Y_2.7Bi_0.3Fe_4.7Mn_0.3O₁₂ (YBFM) compound at various ratios of 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, and 3:7 wt% was prepared by solid-state combustion with glycine as fuel.

Main Results : It was found that the ratio of all ceramics showed perovskite structure with coexisted phases of rhombohedral and tetragonal phases mixed a garnet structure. The intensity of the garnet structure increased with increasing of the YBFM ratios. Grain ceramics showed mixture of large grains and small grains in all ceramics and grains exhibited polygonal shapes. Average grain size density of the ceramics deceased while the density of the ceramics increased from 5.75 g.cm^-3 to 5.96 g.cm^-3when the YBFM ratios increased. In the analysis of dielectric property at room temperature with measuring at 1 kHz of the ceramics at various ratios, it was observed that the dielectric constant () decreased. In contrast, the dielectric loss (tan) increased when the YBFM ratios increased. The analysis of ferroelectric properties from P-E loops at room temperature of all ceramics, it was found that all P-E loops showed non-saturated loops and the P-E loos showed bloated loops with increasing the YBFM ratios which indicated that leakage current was formed. The P_svalue of the ceramics was in the range of 1.72 - 5.97 µC/cm². When the YBFM ratios increased, the P_r and E_c values were increased. For magnetic property of all ceramic ratios with measuring at 27^oC, showed that all ceramics showed the ferromagnetic property. The value of saturated magnetic (M_s), Remnant magnetic (M_r), and Magnetic coercive field (H_c) of all ceramic ratios were in the range of 0.12-5.01 emu/g, 0.003-2.28 emu/g and 61.25-149.19 Oe, respectively, all values increased with increasing the YBFM ratios.

Conclusions : The BNT-BCTS:YBFM ceramic composite exhibited ferroelectric and ferromagnetic coupling properties, which were important characteristics of multiferroic materials. However, at volume ratios of 5:5 to 3:7, the ceramic has a large leakage current, which was a range of inappropriate ratios. Moreover, it is not possible to confirm that the ratio of ceramic was the best. Therefore, further study of the magnetoelectric coefficient is required in the future.

Effect of Burning Stubble and Rice Straw on Concentration of PM2.5 Particulate Matter in Atmosphere : A Case study of Ban Nong Khon Community, Mueang Mai Subdistrict, Ratchasan District, Chachoengsao Province

2024-01-10T13:57:53+07:00

Background and Objectives : To study the problems and causes associated with the burning of stubble and rice straw in relation to the mass concentration of PM_2.5particulate matter in the atmosphere of Ban Nong Khon community, Muang Mai Subdistrict, Ratchasan District, Chachoengsao Province. The research aimed to compare the PM_2.5concentrations resulting from the burning of stubble and rice straw with the air quality standards set by the Pollution Control Department. Furthermore, it aimed to assess the emission rate of pollutants post-harvest.

Methodology : The research utilized research tools, such as process flow diagrams, to collect data on rice cultivation activities and analyzed the relationships between the problems and causes of stubble and rice straw burning using fishbone diagrams.

Main Results : Rice farmers lacked knowledge in managing stubble and rice straw. They believed that burning could effectively control weed and pests, and there was a labor shortage. Another contributing factor was the working methods, as farmers needed speed in soil preparation and plowing for the next planting cycle. The study also found that the PM_2.5particulate matter concentration in the atmosphere between May 20 - 26, 2023, exceeded the air quality standards set by the Pollution Control Department for three days.

Conclusions : The air quality index measurements indicated a beginning of adverse health impacts on the population. Additionally, the study found that the amount of PM_2.5 particulate matter in the atmosphere resulting from the burning of stubble and rice straw left in the rice cultivation area after harvest, with different moisture levels, during the periods of 0, 10, 20, and 30 days, decreased as the burning time increased. The moisture content decreased to 80.8%, 46.8%, 24.5%, and 12.7% (wet basis) respectively. Consequently, the amount of PM_2.5particulate matter in the atmosphere decreased, with concentrations of 35, 30, 24, and 21 μg/m³ respectively. The emission rate of PM_2.5particulate matter was calculated to be 5.4 grams per kilogram of stubble and rice straw.

Optimization of Batik Production Using the Quick Simplex Method

2024-01-09T14:15:36+07:00

Background and Objectives : To calculate the amount of Lampung batik production of the Andanan Batik Lampung company in Indonesia. There are 3 types of batik: printed batik, handmade batik and batik scarf that resulted in that resulted in the maximum profit using the quick simplex method compared with the simplex method.

Methodology : Study the problem of the maximum profit from batik production. Study the simplex method and the quick simplex method. Apply the quick simplex method to the problem of maximizing the profit of batik production. Compare the results with the simplex method. Summarize and discuss the finding.

Main Results : It was found that the Lampung batik production of the Andanan Batik Lampung company should be produced printed batik (4.05 dozen) and handmade batik (5.51 dozen) for the maximum profit 652,530 IDR.

Conclusions : When we calculated using the quick simplex method it was found that this method reduced the calculation process of the simplex table. The simplex method used three tables, but the quick simplex method used only two tables, which gave the same answer as the simplex method. In addition, Python programs were used to help verify the results. In order to achieve the maximum profitability of each type of batik production, it was found that the quick simplex method took time less than the simplex method, which was 0.21457 seconds.

Development of Crispy Roti Flour Using Riceberry Flour as Substitute for All Purpose Wheat Flour

2023-12-16T15:26:49+07:00

Background and Objectives : Riceberry is an antioxidant and a good source of iron, calcium and vitamin E. Riceberry flour was used to increase nutrition value and partially substitute all purpose wheat flour in crispy roti flour. Therefore, the purpose of this research was to develop the crispy roti flour products in order to substitute all purpose wheat flour with 0% (as a control formula), 40%, 60% and 80% of riceberry flour.

Methodology : The study of the physical and chemical properties of heated and unheated riceberry flour revealed that they were significantly different. Physical properties such as lightness, colour and texture, as well as chemical properties such as moisture content, water activity, crude fiber as well as anthocyanin and DPPH inhibition varied. Furthermore, microbiological properties including total plate count were also evaluated. In addition, the results of sensory evaluation of each product’s in terms of colour, odour, texture and overall acceptability were performed by 30 panelists using the 9-point hedonic scale.

Main Results : With respect to the physical properties of lightness, redness, yellowness, hardness and fracturability, it was found that all experiments were significantly different (p<0.05). The lightness, redness, yellowness, hardness and fracturability exhibited a light purple to dark purple colour in the range of 17.99-62.29, 7.91-10.55, 5.61-33.85, 267.26-2517.96 N and 0.80-6.90 mm, respectively. As the amount of riceberry flour increased, lightness, colour and texture also significantly decreased. The chemical properties showed that they were significantly different, except for the moisture. The water activity, moisture content, crude fiber, anthocyanin and DPPH inhibition were in the range of 0.50-0.71, 1.28-3.62%, 0.35-2.15%, 0.00-22.09 mg/g dry weight and 0.00-45.11 mg eq trolox/100g, respectively. The microbiological results revealed that total plate count met the standard regulation according to the Thai Industrial Standards Institute crispy roti (CPS.503/2004). The sensory evaluation indicated that colour, odour, texture and overall acceptability of crispy roti product supplemented with 40% riceberry flour gave the highest scores of 7.57, 7.97, 7.67 and 7.87, respectively.

Study on Production of Functional Ready-to-drink Tea from Borassus flabellifer L. Male Flowers Mixed with Herbs

2023-12-16T15:40:45+07:00

Background and Objectives : Borassus flabellifer L. male flowers are a local herb in Phetchaburi province. This plant has health benefits and is commonly consumed as hot tea. However, preparation time is long and not ideal. This particular ready-to-drink tea is a widely popular product since it is convenient to consume and gives a refreshing feeling. The objectives of this research are the followings : 1. To study the product development of ready-to-drink tea from Borassus flabellifer L. male flowers that use stevia extract as sweetener 2. To study physical properties, chemical compositions, microbiological properties and nutritional value of ready-to-drink tea from Borassus flabellifer L. male flowers with herbs.

Methodology : Study on suitable sweetness of stevia extract of ready-to-drink tea at 5 sweetness levels; 0.00, 0.01, 0.02, 0.03 and 0.04 percent (w/v), respectively. Only one level of sweetness that consumers accepted the most was then selected. Subsequently, this level was developed into ready-to-drink tea from Borassus flabellifer L. male flowers with herbs. There were three herbs that were used which were chrysanthemum, pandanus and butterfly pea. The ratio of Borassus flabellifer L. male flowers to herbs was studied at 90:10, 80:20 and 70:30 (w/w), respectively. The quantity and type of herbs that were most accepted by consumers was selected, this condition was studied on the consumer acceptance, physical qualities, chemical compositions, microbial quality and nutritional value with product labels.

Main Results : It was established that the level of sweetness was obtained at 0.03 percent (w/v). Subsequently, stevia extract addition was used to produce ready-to-drink tea from Borassus flabellifer L. male flowers with three levels of herbs. Sensory quality test showed that, the consumers mostly accepted the pandan supplement formula at the ratio of 90:10 (w/w). Ready-to-drink tea from Borassus flabellifer L. male flowers with pandan has good physical, chemical, and microbiological qualities. This is in accordance with the standards as set by The Ministry of Public Health (No. 356) 2013 that was issued in accordance with the Food Act B.E. 2522 regarding beverages in sealed containers. After nutritional test, the results exhibited that ready-to-drink tea from Borassus flabellifer L. male flowers with pandan is a significantly non-calories drink; suitable for health conscious consumers. The study found that 97 percent of consumers accepted this product and that they would buy the product when released (equivalent to 71 percent of consumers). Moreover, they thought that the reasonable price of the ready-to-drink tea should be 25 baht/500 ml, representing 60 percent.

Conclusions : Ready-to-drink tea from Borassus flabellifer L. male flowers with a sweetness level of 0.03 percent (w/v) stevia extract and pandan leaves at a ratio of 90:10 (w/w) has the highest acceptance from consumers. It was a non-calorie product, rich in antioxidants, suitable for health conscious and is a product that is convenient to consume.

Effect of Beauveria bassiana and Bacillus thuringiensis on Hemocytes of Mealworm Beetle Larvae (Tenebrio molitor L.)

2024-02-16T09:13:40+07:00

Background and Objectives : Biopesticides have been used to control and eliminate pests widely. However, the information on how insect’s hemocytes respond to biopesticides is still limited. The aim of this study was to examine the effect of Beauveria bassiana and Bacillus thuringiensis on insect’s hemocytes using the mealworm beetle (Tenebrio molitor L.) larva as an animal model.

Methodology : The total hemocyte count (THC) and differential hemocyte count (DHC) were examined after T. molitor larvae were treated with biopesticides at concentrations of 0.0025, 0.00625 and 0.0125 g/ml for 24, 48, 72, 96, 120, 144 and 168 hours.

Main Results : Results showed that THC was decreased significantly in the larvae treated with B. bassiana and B. thuringiensis at 24 hours and remained low thereafter. Moreover, the changes in THC were examined in larvae treated with 0.0125 g/ml of biopesticides for 2, 6, 10, 24, 48 and 72 hours. The THC in larvae treated with B. bassiana started to decrease at 6 h, while the decrease in TCH was recorded at 2 h after the larvae were treated with B. thuringiensis. The DHC in larvae treated with B. bassiana and B. thuringiensis were found in 4 types. Prohemocytes was the dominant hemocytes found in the control larvae, but number of prohemocytes decreased significantly when the larvae were treated with B. bassiana and B. thuringiensis at every concentration for 24 hours. Plasmatocytes increased in all examined concentrations and all periods of treatment. Granulocytes responded differently to B. bassiana and B. thuringiensis. The number of granulocytes increased when the larvae were treated with B. thuringiensis at 48 and 72 hours, while the decrease of granulocytes was recorded with highest concentration at 120-168 hours after B. bassiana treatment. In contrast, the number of oenocytes was not changed after biopesticide treatment.

Conclusions : The results indicated the treatment of biopesticides affected the THC and DHC in the T. molitor larvae. This finding provides basic information on how biopesticides affected the immune system in insects.

Effect of Drying Kinetics on the Quality of Dried Gracilaria Salicornia (C. Agardh) Dawson

2023-11-16T13:47:42+07:00

Background and Objectives : People of Koh Samui in Surat Thani Province often bring Gracilaria Salicornia (C. Agardh) Dawson that is in large quantities during the season to be blanched and frozen to preserve raw materials before being processed by drying methods. The purpose of this research was to study the effect of drying kinetics on the physical and chemical quality of dried Gracilaria Salicornia (C. Agardh) Dawson.

Methodology : Drying experiments were carried out at drying temperatures of 60, 70 and 80^oC using six different drying methods were a vacuum drying (VD), a blanching before (B-VD) vacuum drying, and a freezing and thawing at room temperature before vacuum drying (F-VD), a hot air drying (CD), a blanching before hot air drying (B-CD) and a freezing and thawing at room temperature before hot air drying (F-CD).

Main Results : VD at 80^oC of algae showed more rehydration, less color change, higher total phenolic values, higher tannin values, and higher b-carotene values compared to other drying methods. Consequently, the VD at 80^oC was suggested as the best drying condition.

Conclusions : VD at 80^oC of algae showed shorter drying, higher values of the effective moisture diffusivity and lower values of activation energy. The high moisture diffusion at the short drying time creates a large amount of pores inside the product, which corresponds to a high rehydration ratio. Moreover, the short drying period resulted in the high retention of total phenolic compounds, tannins, chlorophyll A and b-carotene in the product. The suitable thin layer model for drying of algae with VD at 80^oC was two-term exponential.

Seasonal Variation in Biomass of Economic Seaweed Genus Caulerpa in Trang Province, Thailand

2024-01-31T15:24:02+07:00

Background and Objectives : The research investigated the seasonal variation in biomass of economic seaweed, Caulerpa, and monitored some water qualities that correlated to a variation of economic seaweed species at Trang province. Notably, the findings would benefit economic seaweed management in the local area, leading to sustainable utilization.

Methodology : Samples of Economic seaweed, Caulerpa were collected to determine biomass, and some water quality parameters were analyzed, covering the entire rainy season (September 2021), late rainy season (January 2022), and summer season (April 2022) from three different stations. Moreover, the correlation of water quality impacting seaweed biomass variation in Trang province was analysed.

Main Results : Two species of seweeds in the genus Caulerpa was found, namely Caulerpa lentillifera and Caulerpa racemosa var. corynephora. There were no seaweed specimens found at study sites in the rainy season, but their average dried-weight biomass was discovered in the late rainy season at 113.97 grams per square meters, and highest dried-weight biomass was in summer season at 251.56 grams per square meters. Considering a correlation between water quality and seaweed biomass, Caulerpa lentillifera exhibited a significantly positive correlation (r=0.694) with salinity at P<0.05. In contrast, a significant negative correlation (r= -0.752) was pH at P<0.05. Caulerpa racemosa var. corynephora showed a very significant negative correlation (r=-0.871) with water temperature at P<0.01. The other significant negative correlations, i.e., r = -0.719, r = -0.746, and r = -0.711, were water transparency, dissolved ammonia-nitrogen, and dissolved orthophosphate at P<0.05, respectively.

Conclusions : Caulerpa lentillifera and Caulerpa racemosa var. corynephora were found at the study sites. Both species were absent in the rainy season, but their biomass was discovered in the late rainy season, and the highest biomass was in summer season. Furthermore, salinity was a crucial parameter that might determine seaweed biomass, as increasing salinity related to increasing seaweed biomass.

Fuel Properties Improvement of Palm Kernel Shell with Torrefaction Process by using Screw Conveyor Reactor

2024-03-04T10:16:06+07:00

Background and Objectives : Waste from oil palm has the potential to be used as a sustainable energy source, despite its low fuel characteristics. To address this, the torrefaction technique was employed to convert the waste into a solid fuel with improved energy efficiency.

Methodology : The study involved designing and constructing a continuous screw conveyor reactor for oil palm kernel shells (PKS) to enhance fuel properties at temperatures ranging from 200 to 300°C and residence times between 50 and 500 seconds.

Main Results : The research found that the mass yield percentage was inversely related to the severity index of the torrefaction. Torrefied PKS had a higher fixed carbon content than untreated PKS, while moisture and volatile content decreased with increased torrefaction temperature and residence time. Optimal conditions were observed at 260°C and 500 seconds, resulting in the highest Energy-mass co-benefit index (EMCI). This produced torrefied oil palm with low moisture and volatile content, higher fixed carbon, and increased heating value by 1.20 times compared to untreated PKS. Additionally, thermogravimetric analysis (TGA) revealed that torrefied PKS had lower moisture, volatile matter, hemicellulose, and cellulose content compared to untreated PKS. SEM analysis shows that the surface of torrefied PKS is smoother, attributed to the decomposition of hemicellulose and cellulose during the torrefaction process. The resulting torrefied product proves to be a more favorable biofuel option compared to untreated PKS.

Conclusions : The continuous screw conveyor reactor demonstrated efficiency in torrefaction for improving biofuel characteristics in waste of oil palm biomass.

PU Virginis The New Light Curves of a Binary Star System PU Virginis

2024-03-20T09:29:22+07:00

Background and Objectives : The study of the binary star system led to an understanding of the mechanism and behavior of the stars through the analysis of the multi-band light curve. We selected a binary star system PU Virginis, which was only recently discovered.

Methodology : The observational data were obtained at the Regional Observatory for the Public in Chachoengsao, under the auspices of the National Astronomical Research Institute of Thailand (Public Organization) with the CCD photometer via the 0.7-m reflecting telescope in B, V and R bands. Including data obtained from the Kepler space telescope. The all data were used to create the light curves. The light curves were analyzed using the Wilson-Devinney code to determine the physical parameters. Moreover, the light curves analyze by the Fourier equation.

Main Results : The results of the physical parameters obtained from the Wilson-Devinney code are as follows: the temperature of the secondary star is approximately 5,000 K, the inclination is less than 30 degrees, the mass ratio is about 0.68, and the secondary component is expected to have dark spots. While Fourier analysis suggests that it might be an ellipsoidal variable star.

Conclusions : The binary star system PU Virginis might be the ellipsoidal variable star.

Terminalia chebula Extract Inhibited Biofilm Formation and Enhanced Antibacterial Activity of Antibiotics against some Drug Resistant Bacteria

2024-03-27T09:21:03+07:00

Background and Objectives : Terminalia chebula is commonly used to treat frequent disease. This study investigated the synergistic effect of an ethanol extract from Terminalia chebula fruit in combination with antibiotics against some bacteria.

Methodology : Antimicrobial activity was determined by Broth microdilution susceptibility test, Synergy effect of Terminalia chebula extract in combination with antibiotics was tested by Checkerboard assay and antibiofilm activity was conducted by Crystal violet staining assay.

Main Results : T. chebula extract combined with Ampicillin had synergistic effect against B. cereus and B. subtilis by the FICI values of 0.187 and 0.14, respectively. Likewise, the synergism of T. chebula extract combined with Oxytetracycline was detected against E. coli and FICI value was 0.5. The antibiofilm activities of T. chebula extract were examined and the results showed that T. chebula extract inhibited the biofilm formation of E. coli, P. aeruginosa, and S. aureus during 8–24 hours of incubation. Oxytetracycline inhibited the biofilm formation of E. coli, P. aeruginosa and S. aureus better than T. chebula extract at 4–12 hours.

Conclusions : An ethanol extract from Terminalia chebula fruit showed synergy effect with ampicillin and oxytetracycline and had antibiofilm activity against some bacteria.

The Diversity of Crabs under Complex Habitats around Ao Chalok Baan Kao Beach, Koh Tao, Suratthani Province

2024-01-08T22:41:17+07:00

Background and Objectives : The complex habitats promotes high diversity of crabs by providing greater space for refuge, food resources and area-independent. This study aims to determine species diversity, abundance and distribution of crabs around Ao Chalok Bann Kao Beach, located in the southern part of Koh Tao, the unique area with complex habitats all within a 500-meter stretch.

Methodology : The species diversity, abundance and distribution of crabs around Ao Chalok Bann Kao Beach, with 4 complex habitats : sandy beach, rocky beach, muddy beach, and mangrove forest were studied as well as the life history of the most abundance crabs in rocky beach and muddy beach.

Main Results : The results showed the diversity of crabs, comprising 11 families, 16 genera, and 22 species. Notably, new record of three species of sentinel crabs (Macrophthalmus convexus, M. brevis, and M. milloti) living in the same muddy beach was identified. A rare species, the purple land crab (Gecarcoidea lalandii), was observed migrating from the forest to the beach through drainage pipes for spawning in the sea, highlighting the threat posed by human destroying their spawning routes. The rocky beach was densely populated with yellow-legged hermit crabs (Clibanarius virescens), reaching about 1,393.52 individuals per square meter. The muddy beach had a high density of red-bellied sentinel crabs (Macrophthalmus convexus), at 20.33 individuals per square meter. These abundant crabs play a crucial role in providing environmental services at Koh Tao.

Conclusions : Ao Chalok Ban Kao Beach had complex habitats for crabs. As a result, biodiversity is high and different from common areas. The impact of human threatened crab habitats on Koh Tao necessitate protective and conservation measures, particularly for purple land crabs, and declaring Ao Chalok Ban Kao Beach as a biodiversity important area (BIA).

Carbon Deposition over Ni/ZrO2 Catalyst for Dry Reforming of Methane Reaction

2024-03-08T16:52:00+07:00

Background and Objectives : The increase of greenhouse gases (carbon dioxide and methane) in recent decades has led to a global warming crisis. As a result, researchers are interested in solving this problem. Dry reforming of methane (DRM) is an attractive reaction for syngas production (hydrogen and carbon monoxide) from greenhouse gases. The nickel-based catalysts are often used as catalysts in DRM reaction, because of their high activity and low cost. However, there is also a disadvantage to the carbon deposition, leading to the catalyst deactivation. ZrO₂ has been considered an attractive support due to its good resistance to coke formation. Therefore, this work is interested in studying the formation of carbon deposits on various Ni/ZrO₂ catalysts.

Methodology : The Ni(NO₃)₂ solution was deposited on ZrO₂, which is prepared in four different ways with 10% Ni loading by the impregnation method. The physico-chemical properties of supports and catalysts were analyzed by XRD, N₂ adsorption-desorption, and H₂-TPD techniques. The type and amount of the deposited carbon on the spent 10% Ni/ZrO₂ catalysts were characterized by XRD, O₂-TPD and TEM techniques.

Main Results : Four ZrO₂ samples with different microstructure and morphology were used as catalyst support. The catalytic performance of 10%Ni/ZrO₂ catalysts conducted in fixed-bed reactor DRM reaction was found the different catalytic activity of different catalysts.

Conclusions : It was found that the effects of Ni particle size and zirconia phase had a significant influence on the catalytic activity. Moreover, both the type and amount of carbon deposition on spent Ni/ZrO₂ were also related to the catalytic activity.

Fluxoid Quantum hc/2e Protected in an S-Wave Superconducting Ring

2024-02-15T08:47:13+07:00

Background and Objectives : A question of the possibility of the crossover of flux periodicity from the usual Little-Parks value of a fluxoid quantum to a period when the radius of an s-wave superconducting ring is reduced, is examined in detail.

Methodology : The method of Gor’kov Green's function is employed to calculate the superconducting critical temperature equation. The numerical analysis is studied to explore the fluxoid crossover phenomenon.

Main Results : We study the phenomenon of fluxoid crossover both in the cases of large- and finite-radius limits and found a period of oscillation of the critical temperature is always given by . The obtained results show the fluxoid is strictly quantized in units of .

Conclusions : Our analysis provides the results contrast to the theoretical work of Wei-Goldbart in the context of a one-dimensional superconducting clean ring. The study enhances the proper understanding of flux periodicity and fluxoid quantization in the critical temperature of an s-wave superconducting ring threaded by magnetic flux.

Seasonal Variation of Water Quality in Bang Phra Reservoir and Nearby Canals at Chonburi Province

2024-01-31T09:51:27+07:00

Background and Objectives : Bang Phra Reservoir is an important source of fresh water for tap water production and consumption in Chonburi Province and nearby areas. Deteriorating water quality can indeed have significant impacts on livelihoods and economic development, particularly in the industrial sector. Therefore, this research study aims to study and evaluate the water quality of Bang Phra Reservoir and nearby canals. The data obtained from the study will be used as guidelines for monitoring water quality changes according to the seasons, which will impact the use of water for consumption and domestic purposes.

Methodology: Water samples were collected from August 2019 to July 2020, divided into 5 canal stations and 1 reservoir station. The water parameters are including general water quality (temperature, pH, dissolved oxygen, BOD, total suspended solids and chlorophyll a) and dissolved inorganic nutrients (total ammonia, nitrite, nitrate, silicate and phosphate).

Main Results: The results of the study showed that the temperature, pH, dissolved oxygen, BOD, suspended solids and chlorophyll a averaged 30.2±2.7 ^oC, 7.7±0.6, 5.1±1.8 mg/l, 2.8±1.7 mg/l, 23.9±40.2 mg/l, and 7.0±11.5 µg/l, respectively. Dissolved inorganic nutrients including ammonia, nitrate and phosphate had average values of 44.5±71.0, 329.9.9±1,864.1, and 3.1±2.6 µM, respectively. Furthermore, it was found that water quality varies by season (p<0.05), with water quality deteriorating during the rainy season.

Conclusions: Our results indicated that the water qualities of Bang Phra reservoir and nearby canals were compiled the Surface Water Quality Standard and Classification 2. (for consumption, conservation of aquatic animals and fisheries) and it can be used as water for drinking water production. However, there should be monitoring of the dissolved oxygen levels, which may be lower than the standard in some season

Effect of Drying Temperature on Physicochemical Qualities and Antioxidant Capacity of Tamarind Shoot and Flower

2024-02-02T10:43:36+07:00

Background and Objectives : Tamarind leaves are rich in antioxidant polyphenols and bioactive activity. This research aimed to study the effect of drying temperature on the physicochemical qualities, bioactive compounds, and antioxidant effects of tamarind shoot leaves and flowers.

Methodology : Drying tamarind shoots and flowers with a hot air drying at 50, 60 and 70^oC until water activity (a_w) values were lower than 0.5. Physicochemical qualities including a_w, brightness (L*), redness (a*) and yellowness (b*) values of dried tamarind shoots and flowers were examined. In addition, antioxidant properties including total phenolic compounds, total flavonoids, 2,2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging activity and ferric reducing antioxidant power (FRAP) of the hot water extracts of dried tamarind shoots and flowers were evaluated.

Main Results : The values of water activity of dried samples were ranged 0.35 – 0.43. The L* and b* values of dried tamarind shoot leaves were significantly increased when drying temperature rose (P≤0.05). The extract of tamarind shoots dried at 50ºC for 3.5 h exhibited the highest values of total phenolic compounds (3.10 mg GAE/g), flavonoids (1.54 mg CE/g) and FRAP value (6.64 mg TE/g). Moreover, the extract of tamarind shoot leaves found to have significant greater potent of antioxidant capacity than those found in flower part (P£0.05).

Conclusions : Tamarind shoot leaves exhibited higher antioxidant quality than those found in the flower part. The optimal drying condition for tamarind shoot leaves was 50^oC for 3.50 h resulting in the superior antioxidant quality than those found in other drying temperature.

Effects of Vitamin C in Indian Gooseberry (Phyllanthus emblica) Extract on Growth Performance, Blood Biochemical, Non-Specific Immune Responses and Bacterial Resistance, Streptococcus agalactiae in Nile tilapia (Oreochromis niloticus)

2024-03-12T07:51:50+07:00

Background and Objectives : The aim of this research is to determine the effects of vitamin C in Indian gooseberry (Phyllanthus emblica) extract on growth performance, blood biochemical, non-specific immune response and bacterial resistance against, Streptococcus agalactiae in Nile tilapia (Oreochromis niloticus)

Methodology : A completely randomized design (CRD) was used in this experiment, Five groups of Nile tilapia were fed experimental diets containing control group (without vitamin C), T1-T3: supplemented with vitamin C (natural ascorbic acid) from Indian gooseberry extract at 3, 6, and 10%, and T4: supplemented synthetic vitamin C at 3 g/kg for 60 days.

Main Results : The experimental fish supplemented with Indian gooseberry extract at 3 % had a final average weight, weight gain, average dairy gain (ADG) and the feed conversion ratio (FCR) were not significantly different compared with Indian gooseberry extract at 10 % and synthetic vitamin C groups (P > 0.05). Nile tilapia in the experimental group were fed with vitamin C (natural ascorbic acid) from Indian gooseberry extract and synthetic vitamin C has a growth rate, non specific immune response; Phagocytic activity and lysozyme activity; and bacterial resistance, S. agalactiae significantly better than control group (P<0.05).

Conclusions : The results of this study can be seen that Indian gooseberry (P. emblica) extract can be used as a supplemented in tilapia diets to replace the use of synthetic vitamin C.

Blue Swimming Crab Shells Extracted Carotenoid on Color Inducing of Lambchop Rasbora (Trigonostigma espei)

2024-02-15T23:36:05+07:00

Background and Objectives : The carotenoid was extracted from blue swimming crab shells, waste from the fisheries industry for utilization and value added. The efficiency of carb shells extracted carotenoid on color inducing of Lambchop rasbora (Trigonostigma espei Meinken, 1967) was studied to avoid chemical use, increase the income of a farmer, and value add of Lambchop rasbora before sending to the ornamental fish market.

Methodology : The carotenoid was extracted from blue swimming crab shells by ethanol. The carotenoid concentrations of 0 (control group), 25, 50, 75, and 100 mg astaxanthin per 1 kg of feed were infused into ornamental fish feed. The commercial astaxanthin mixed feed was used for comparison. The 15 adult Lambchop rasbora with 2.50±0.19 cm of total length were stocked in a square aquarium with 10 liters of water with triplication in each group. After four weeks of rearing, redness values (+a*), yellowness values (+b*), lightness value (L*), growth and survival rate were estimated.

Main Results : The fish fed with feed containing crab shells extracted carotenoid 25, 50, and 75 mg astaxanthin per 1 kg presented redness values, 4.39±0.09, 4.64±0.21 and 4.53±0.18, respectively, and no significant difference with the commercial feed group, 4.19±0.17 but different (p<0.05) from the control group, 2.37±0.21. While, the redness value of the 100 mg astaxanthin per 1 kg group was 5.27±0.24, and significantly higher than others (p<0.05). The yellowness values of 25, 50, 75, and 100 mg astaxanthin per 1 kg, and commercial feed groups were no significant differences (p>0.05). However, theirs were significantly different from the control groups. The blue swimming crab shells extracted carotenoid did not affect the lightness value, growth, and survival rate of fish (p>0.05).

Conclusions : This study can conclude that blue swimming crab shells extracted carotenoid can induce redness, yellowness and the color intensity of skin of Lambchop rasbora. It has the potential to utilize and value added crab shell waste from the fisheries industry.

On the Diophantine Equation Where is a Positive Integer

2024-02-15T14:11:40+07:00

Background and Objectives : to find the solution to the Diophantine equation where and are non-negative integers, and is a positive integer, which is in the form for some non-negative integer .

Methodology : proving by contradiction and various properties related to the congruent in order to find the Diophantine equation’s solutions.

Main Results : the Diophantine equation has no any solution.

Conclusions : the Diophantine equation where is a positive integer, which is in the form for some non-negative integer , has no any solution for and are non-negative integers.

Effect of Bacillus licheniformis on Growth, Survival Rate and Immune of Giant Freshwater Prawn (Macrobrachium rosenbergii)

2024-02-21T15:55:40+07:00

Background and Objectives : Giant freshwater prawn are economic freshwater aquatic species. The intensive prawn culture affects on slow growth and disease outbreaks. Currently, there are biological shrimp farms using microorganism sush as Bacillus spp. for enhance shrimp growth and immune. The objective of this study is to determine effects of Bacillus licheniformis on growth survival rate and immune of Macrobrachium rosenbergii .

Methodology : Prawns (size 5.23±0.007 g) were stocked in 0.52×1×0.42 meters tanks at density 13 prawns/tank (25 prawns/m²). The experiment was Completely Randomized Design (CRD) and divided in to 4 treatments. Each treatment had 3 replications. The first treatment was commercial pelleted feed (control), the 2^nd, 3^rd and 4^th treatments were commercial pelleted feed with B. licheniformis at concentration 1, 5 and 10 g/feed 1 kilograms respectively. The growth, survival rate and immune were recorded during culture for 60 days.

Main Results : Growth and survival rate of prawn in treatment 4, 3 and 2 fed with B. licheniformis were 11.71±0.29, 11.18±0.56, and 10.41±0.71 grams, respectively and significantly higher than the control group (p<0.05). For the prawn immunity, prawn fed with probiotic in treatment 4 had total hemocyte count and phagocytosis activity better than control group (p<0.05).

Conclusions : Prawn fed with diet containing B. licheniformis at concentration 10 g/feed 1 kilograms was able to enhance growth, survival rates and immune than the control group.

Optically Stimulated Luminescence Dating Revealed the Late Quaternary Coastal Sediments in Songkhla Coast, Thailand

2023-12-23T16:38:07+07:00

Background and Objectives : Coastal sediments along the Songkhla coast still lack chronological data to describe their evolution. The objective of this study was to determine the chronological ages of the lagoonal side of the Songkhla coastline area, with the purpose of conducting a preliminary investigation into the development of the Songkhla lagoon.

Methodology : The topographic map of the coastal sediments that were classified early were taken with the real-time kinematic survey by the Global Navigation Satellite System. Samples were taken from the old ridges and plains behind the ridges using a light-blocking (PVC) cylinder tube and dated by optically stimulated luminescence (OSL) with the single aliquot regenerative dose protocol.

Main Results : A field survey by GNSS-RTK confirmed the two old ridges and plains parallel to the Songkhla lagoon coast in Hatyai district. The dating results were 10.0, 30.5, 39.2 ka (thousand years), and a saturated equivalent dose sample.

Conclusions : Quartz OSL dating revealed that the inner old ridge and plain behind the ridge were deposited during the humid period approximately 30–40 ka before the drought period in the late glacial maximum (LGM). At the same time, the youngest sediment here was the outer plain behind the ridge that was deposited 10 ka ago when the sea level transgressed in the early Holocene. Since then, only tidal flat sediment has been found on the lagoon coast. However, in this area, there was a hiatus during LGM.