RMUTP Research Journal Sciences and Technology

Development of Interlocking Block Mixed with Waste Stone Dust and Para Rubber Wood Fly Ash

Khwanchiwa Yongsata — 2024-06-30

This research has the objective to develop interlocking block with waste stone dusts and para rubber wood fly ash. This research used the solder material ratio: gross which equals to 1:7 by the weight. The cement displacement ratio with waste stone dusts and para rubber wood fly ash was at the percentage of 0, 25, 50 and 75 by the weight. The water to material ratio was equal to 12% by the weight. The qualities of interlocking blocks were investigated after curing for 7, 14 and 28 days by comparing with the standard of community products of interlocking block (TCPS 602/2547) non-load-bearing type. The results showed that the compressive strength and the density of interlocking block tended to decrease with increasing the waste stone dusts and para rubber wood fly ash. The water absorption value of interlocking block tended to increase with increasing quantity of replacement materials. The best ratio of interlocking block replacing the cement waste stone dust was at 25% by the time that the density, water absorption, and compressive resistance were 1825 kgs per cubic meters, 250 kgs per cubic meters, and 3.47 megapascal, respectively. The best ratio of interlocking bricks replacing the cement with waste stone dusts and para rubber wood fly ash was at 25% considered at the age of 28 days by the time that the density, water absorption, and compressive resistance were 1,836 kgs per cubic meters, 256 kgs per cubic meters, and 3.28 megapascal, respectively.

Effect of Microwave Drying and then Hot-Air Drying on Quality of Longan Flesh

Paidaeng Khwanchai — 2024-06-30

The effect of microwave power at 300 and 450 W for 3, 6 and 9 min followed by hot air drying with temperature of 65 °C for 6 and 8 h on the physical and chemical properties as well as consumer acceptability of flesh longan was investigated. It was found that the moisture content in the dried longan flesh using microwave drying followed by hot air convective drying was faster than the hot air drying alone at 65 °C for 10 h. Longan flesh with hot air at 65 °C for 10 hours and longan flesh with microwave at 450 W for 6 or 9 min followed by hot air at 65 °C for 8 h were obtained the dried longan standard criteria, while other drying conditions of dried longan flesh products were in the range of intermediate moisture food (IMF). The hardness of longan flesh at 450 W was higher than that of dried longan flesh at 300 W. The loss of lightness (L* parameter) or the increase of redness (a* parameter) and browning index in dried longan flesh at 450 W could be associated with the increase of enzymatic and non-enzymatic browning reactions after drying process. Panelists were most satisfied with sensory qualities of the dried longan flesh using microwave power 450 W for 9 min followed by hot air drying for 6 h. It was indicated that drying at 450 W (for 9 min) and hot air drying for 6 h was acceptable for the production of dried longan flesh. Moreover, compared to the 65 °C hot air drying, microwave followed by hot air-drying process reduced drying time by 40%.

Content of Bioactive Compounds and Antioxidant Properties of Winter Fruit Wines Grown in Thailand

Rungthiwa Wongpaisanrit — 2024-06-30

The objective of this research was to quantify carotenoids content, anthocyanin content, flavonoid compounds content, phenolic compound content and antioxidant activity by 2, 2-diphenyl-1-picrylhydrazyl scavenging capacity (DPPH) and 1, 10-Phenantroline (Phen) in 5 types of winter fruit wine, namely; plum (Prunus domestica L.), plum (Prunus mume), amber peach (Prunus persica var. persica), golden peach (Prunus persic), cherry (Prunus cerasifera) and mixed fruit (peach, plum). It was found that the total carotenoid contents of the winter fruit wine samples were equal to 0.70+0.01, 0.61+0.03, 0.63+0.00, 0.67+0.01, 0.63+0.00 and 0.64+0.03 mg/l, respectively (p<0.05), the anthocyanin content measured by the pH-differential method were 3.81+0.00, 0.97+0.06, 1.22+0.12, 0.05+0.01, 0.02+0.01 and 0.57+0.03 mg/l, respectively (p<0.05). The amount of flavonoid compounds were 0.33+0.01, 0.39+0.00, 0.04+0.01, 0.15+0.01, 0.21+0.010 and 0.15+0.01 mg/l, respectively (p<0.05). The total phenolic compounds were 16.19+0.01, 17.31+0.05, 11.37+0.03, 9.42+0.04, 9.47+0.06 and 15.31+0.02mg/l, respectively (p<0.05). The DPPH antioxidant capacity were 47.65+0.06, 55.54+0.01, 9.75+0.02, 3.90+0.03, 0.58+0.01 and 23.86+0.00, respectively (p<0.05). The antioxidant activity of Phen were 151.43+0.03, 143.21+0.03, 5.01+0.35, 5.89+0.01, 7.15+0.05 and 41.92+0.02 mg/l, respectively (p<0.05). It can be seen that all 5types of winter fruit wines contain carotenoids, anthocyanin content, phenolic compounds content and antioxidants was different. This may be used as the basis for establishing the identity of the fruit wine product in the OTOP business and differentiating the product by inserting antioxidant information to add value to the product.

Computational Efficiency for Calculating Determinants of Block Matrices

Puttha Sakkaplangkul — 2024-06-30

In this paper, we study a method for calculating the determinant of a matrix divided into four submatrices using the formula of Schur. The purpose of this study is to analyze and provide the formula for the number of flops for matrix determinants consisting of submatrices of different sizes. The results are analyzed based on matrices with a submatrix on the first main diagonal of size . It shows that using the formula of Schur to calculate the determinant gives the number of flops close to calculating the determinant directly using the Gaussian elimination method. We also prove the relationship between the number of flops of determinant calculations by using the formula of Schur and direct determinant calculations using the Gaussian elimination method. Numerical experiments are presented, and the conclusions of the theoretical analysis are well supported.

Product Development of Ice Cream Fiber-Fortified from Pomelo Puree

Jurupat Kanjanarong — 2024-06-30

Development of fiber-fortified ice cream product from pomelo puree with a stabilizer in 4 recipes of 5, 7, 10 and 15 % was demonstrated. The results showed that the overrun and viscosity value of ice cream increased whereas the melting rate significantly decreased depended on pomelo content. Ice cream without pomelo puree remained the highest in sensory acceptance, and with the addition of pomelo puree, overall acceptance decreased. The ice cream formula with 7% pomelo puree was the highest overall acceptance (6.28±1.88), with no statistically significant difference from the standard formula without pomelo puree added. Overrun was 41.15±0.59%, the viscosity was 698.02±5.56 cps, and melting rate at 30 minutes was 22.23±0.24%. In addition, chemical analysis of 7% pomelo puree ice cream found that total soluble solids was 25.28±1.88 °Brix, pH was 3.35±0.30, and moisture and fiber content were 71.72 and 7.73 percent respectively when compared to a controlled ice cream using a commercial substance (CREMODAN® SE 709-M; Danisco Thailand Co., Ltd.) as a stabilizer, it was found that pomelo puree -infused ice cream had significantly higher fiber content (p ≤ 0.05). Also, the storage of pomelo ice cream at -20 °c for 12 days showed a lower total number of microorganisms and coliform bacteria than a standard criterion of the Ministry of Public Health.

Effect of Phulea to Nanglea Pineapple Ratios on Physical, Chemical and Sensory Evaluation in Pineapple Crisps

Kritsanakan Phaphothirat — 2024-06-30

This research aimed to select of pineapple chips recipe and study the ratio of Phulea pineapple to Nanglea pineapple in pineapple crisps. The selected pineapple crisps consisted of a percentage of cassava starch, all-purpose flour, Pattavia pineapple, water, and sugar for 52.46, 11.31, 16.39, 16.39 and 1.64 respectively. A study of the ratio of Phulea pineapple to Nanglea pineapple in pineapple crisps of 100:0, 72:25, 50:50, 25:75, and 0:100. The result showed that: the ratio of 50:50 is an appropriate ratio for making pineapple crisps, with sensory evaluation being the highest in all aspects. The colour quality are (L*) 87.70, (a*) 12.33 and (b*) 53.80. and research also showed the ratio of Phulea pineapple to Nanglea pineapple in pineapple crisps in different ratios did not affect the crispness and a_w Value.

Effect of Drying Temperature Level on Vacuum Drying of Okra Combined with Far-infrared Radiation

Piyabud Innu — 2024-06-30

This research aimed to study the effect of infrared radiation assisted vacuum drying on the change of moisture content of okra and to determine the electrical energy and specific energy consumption used for drying. The physical property in terms of the color of dried okra powder was examined. Okra sheets with a size of 30x30 (width x length) cm and a thickness of 5 mm were dried under an absolute pressure of the drying chamber of 7 kPa and the drying temperatures of 70, 80, and 90^oC until the moisture content of the okra was lower than 10% wet basis. The experimental results showed that dried okra at high temperatures could reduce moisture faster than that at low temperatures. Drying okra at the temperature of 70^oC had a significantly higher the electrical energy and specific energy consumption than that of 80 and 90^oC (P£0.05). The electrical energy and specific energy consumption used for drying okra at 80 and 90^oC were not significantly different (P>005). In addition, okra powder dried at high temperatures had significantly lower lightness (L* value) and greenness (-a* value) than that at low temperatures (P£0.05). Okra powder dried at the temperature of 70^oC had significantly lower yellowness (b* value) than that of 90^oC (P£0.05). However, the yellowness (b* value) of okra powder dried at the temperature of 80^oC and okra powder dried at the temperatures of 70 and 90^oC were not significantly different (P>0.05). Therefore, okra powder dried at an absolute pressure of the drying chamber of 7 kPa and the drying temperature of 70^oC had the best color quality compared to that of 80 and 90^oC.

Study on Antioxidant Activities and Total Phenolic Contents Analysis from the Elixir Extracts

Jirapat Laysing — 2024-06-30

According to folk medicine beliefs, elixir was a body tonic with properties that help people stay healthy and live longer. The purposes of this research were to compare the antioxidant activities, and to compare the total phenolic contents from bolus elixir extracts. The drug was extracted by boiling with distilled water and maceration with 95%, 70%, and 50% ethanol, respectively. The results showed that extracts with 50% ethanol had the best antioxidant activities, and found the highest total phenolic contents as follows: 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay gave IC₅₀ of 87.23±1.53 µg/mL, Ferric reducing antioxidant power (FRAP) assay showed the value was 40.96±0.91 mgFe²⁺/g, and Trolox equivalent antioxidant capacity (TEAC) value was 20.33±0.85 mgTrolox/g, and total phenolic contents was equal to 25.53±1.54 mg GAE/g. The extracts with 70%, 95% ethanol, and distilled water showed less effective than the extracts with 50%, respectively.

Product Development of Low-Calorie Ready-to-Drink Soy Bean Milk Pudding Supplemented with Black Sesame for the Elderly

Achara Dholvitayakhun — 2024-06-30

This research aimed to develop a low-calorie ready-to-drink soybean milk pudding supplemented with black sesame for the elderly. The chemical, physical properties, and sensory evaluations of pudding products supplemented with 5 10 15, and 20% soybean milk weight were determined. Results showed that an increasing amount of black sesame caused a decrease in lightness (L*), but redness (a*) and hardness increased (p≤0.05). However, it did not affect yellowness (b*), springiness, and total soluble solids. Sensory evaluation showed that the product with 15% black sesame showed a like very much score (7.71±0.78). Therefore, this product was selected for studying the types and amounts of sweeteners. Results revealed that the different types and quantities of sweeteners resulted in different brightness (L*) and hardness values. The substitution of 25% sugar with sorbitol in soybean milk pudding received the highest score of sensory evaluation in like moderate score. The product's nutritional composition was 81.03% moisture, 2.0% protein, 3.6% fat, 13% carbohydrate, 0.37% ash, and 92 Kcal/100g.

Development of an Infrared-assisted Pneumatic Paddy Drying System

Boontarika Sila — 2024-06-30

The development of various dryers to dry paddy still faces a significant problem of high energy consumption. Therefore, this research objective was to develop an infrared-assisted pneumatic paddy drying system and study the possibility of reducing the problem. The study consists of 3 methods of drying paddy, namely: 1) drying paddy by hot air 60°C; 2) drying paddy by hot air 60°C with 50 W infrared radiation; and 3) Drying paddy with 800 W infrared radiation. In this study, 20 kg of Thai jasmine 105 paddy with initial moisture content 23%w.b. was dried until 14%w.b. at drying air velocity and paddy feed of 6 m/s and 8.4 kg/min respectively. The performance of drying was evaluated based on the drying characteristic curve, drying rate and the specific energy consumption (SEC) of the developed drying system. The results showed that hot air combined with infrared radiation in drying had fastest time 220 min in drying. Drying rate of hot air drying and hot air drying combined with infrared radiation was no statistical difference (p<0.05). The lowest SEC was 14.24 ± 0.88 MJ/kg _water and it was not significantly different (p<0.05) when comparing within all experiment methods.

The Effect of Watering rate to Napier Pak Chong 1 Grass on Its Yield and Quality Using a Soil Moisture Sensor Module

Kittisak Wasantiwong — 2024-06-30

The research aims to study on watering rates per the Napier Pak Chon 1 grass yield and quality, including fresh-weight, dry-weight and crude protein content by using randomized complete block design in each field cutting Napier grass 3 times: 1^st, 70-days aged, 2^nd at 115-days aged, and 3^rd at 150-days aged. The watering rates of water at 12, 16, and 20 cubic meters per rai. The results showed that in the 1st cutting was not different significantly (P > 0.05), the results as fresh-weight of 4,190+403, 4,019+435, and 3,995+320 kg per rai, dry-weight of 779+109 746+86, and 734+64 kgs per rai, crude protein of 10.88+1.02, 10.73+0.83 and 10.08+0.98 percent, and amount of watering 6 times per plot. The 2nd cutting was not different significantly (P > 0.05), the results as fresh-weight of 7,075+618, 6,924+511, and 6,837+511 kgs per rai, dry-weight 1,085+64, 1,037+123, and 1,036+37 kgs per rai, and crude protein of 12.91+1.54, 12.88+1.33, and 12.86+1.19 percent and amount of watering 3 times per plot. In the 3rd cutting, the results near by the 2nd cutting and was not different significantly (P > 0.05). The results as fresh-weight of 7,590+691 7,446+555 and 7,456+788 kgs per rai, dry-weight of 1,138+162, 1,161+166, and 1,112+108 kgs per rai, crude protein of 12.98+1.55, 12.95+1.58, and 12.94+1.08 percent, and amount of watering 5 times per plot. In conclusion, the optimum watering rate was 12 cubic meters per rai a time.

Location Selection of Beverage Distribution Center Using a Mathematical Modeling Considering Transportation Logistic Costs

Pornpimol Chaiwuttisak — 2024-06-30

This research aims to select the location of the beverage distribution center with the lowest total cost of transportation using a mathematical model by considering the Muang districts of all 76 provinces, excluding Chachoengsao Province, where the factory is located. In the present study, two scenarios were divided: 1) when only one distribution center was required; 2) when four distributions, according to four regions, were required. The results processed by IBM ILOG CPLEX Optimization Studio have shown that Scenario 1, the total transportation cost is 786,107.75 baht/month and the break-even point is 6 years 9 months 1 day. Ayutthaya is the optimal province to set up a distribution center. The solution obtained from the model is consistent with the opinions of the executives of the company, Scenario 2, the total transportation cost is 401,499.61 baht/month and the break-even point is 8 years 2 months 6 days. The results of the establishment of distribution centers classified by regions are as follows. Phra Nakhon Si Ayutthaya Province, Uttaradit Province, Roi Et Province and Phang Nga Province for the central, northern, northeastern, and southern regions respectively.

Performance Evaluation of a Hybrid Evaporative Cooling – Vapor Compression Air Condition

Natthapon Aumpai — 2024-06-30

A hybrid system combining an evaporative cooler and a traditional vapor-compression air-conditioner was investigated and evaluated its performance in this study. A 2.30m x 2.30m x 2.75m building was built at Suranaree University of Technology, Nakhon Ratchasima. A vapor-compression air-conditioner was installed in the building. Five different types of indirect evaporative coolers were built and installed in the building. They are a Maisotsenko (M) - cycle type, cross-flow with regeneration type, cross-flow without regeneration type, counter-flow with baffles type, and counter-flow without baffles type. The test results showed that the cross-flow without regeneration type provided the highest coefficient of performance (COP) and wet-bulb effectiveness compared with the other 4 types. Its maximum COP and wet bulb effectiveness were 11.68 and 0.97, respectively. This type was also easier to build because it is less complicated when compared to the others. Therefore, the cross-flow without regeneration type was chosen. It found that installing the evaporative cooler outside the building can reduce energy consumption by 30.77% compared with installing the cooler inside the building. It also found that intermittent water spraying on the cooling core is better than continuous water spraying 5 min spraying of water every 2 h can reduce the outlet air temperature of the cooler to about 8 °C.

The Development of Mantou Product Supplement Purple Waxy Corn Flour

Nittaya Phungam — 2024-06-30

The replacement of wheat flour with purple waxy corn flour (PWCF) in mantou product at three levels, 15, 30 and 45 % was compared with control (0% PWCF). The results demonstrated that the moisture contents of mantou product with varying amounts of PWCF were no significant difference but were different from control sample without PWCF (p>0.05). However, the addition of 30% PWCF to mantou product resulted in an increase in water holding characteristics (63.24%) and a slightly higher specific volume than other formulas (1.85%). Additionally, 30% PWCF replacement resulted in an increase in redness (a*) and yellowness (b*) values (6.08 and 10.49, respectively). When the mantou products were stored at -18 °C for 28 days, it was found that the 30% PWCF replacement mantou product tended to change in qualities such as texture (springiness), water holding characteristics and specific volume. In addition, mantou products that were replaced with 30% PWCF and control sample were significant difference in chemical components, such as protein, fiber, ash, and anthocyanin (p≤0.05). The protein, fiber, ash, and anthocyanin contents of mantou products with 30% PWCF were 3.45 %, 7.50 %, 0.61%, and 7.35 mg, respectively which were higher than control mantou product (2.52 %, 6.50 %, 0.44 % and 0 mg, respectively.

Product Development of Sweetened Condensed Rice Milk from Rai Dok Kha Phang Nga Rice

Janya Khongkaew — 2024-06-30

The objectives of this research were to formulate sweetened condensed rice milk from Rai Dok Kha Phang Nga rice by studying the ratio of rice to water in a rice milk preparation step, to study the suitable amount of Luo Han Kuo powder used as a sweetener for sucrose substitute, to study the appropriate amount of supplementation with rice protein powder, and to analyze nutritional values of sweetened condensed rice milk product. The sweetened condensed rice milk obtained at each stage was evaluated for quality and statistical analysis. From the experiment, it was found that a ratio of crushed rice mixed with water affects the concentration of the product. From the results of sensory evaluation, it was found that the preparation of rice milk using Dok Kha rice mixed with water at a ratio of 10:40 received a higher preference score than using the ratios of 5:45 and 15:35 (p≤0.05). The use of Luo Han Kuo sugar powder sweetened replaced 30% sugar resulted in the product having a higher preference score than substitutions of 40% and 50% (p≤0.05). By adding rice protein powder, the sweetened condensed rice milk products had a lighter color. The viscosity was higher, and panelists rated the sweetened condensed rice milk product fortified with 4% rice protein powder more highly than those fortified with 2% and 6%.(p≤0.05). The developed sweetened condensed rice milk product consists of 46% Phang Nga rice milk, 35% granulated sugar, 15% Luo Hang Kuay sugar powder, and 4% rice protein powder. The 100 g of developed sweetened condensed rice milk was 215.66 kcal with a protein content of 3.03 g, 0.82 g of fat, 49.04 g of carbohydrates, and 8.88 mg of anthocyanins.

Academic article: Spheroidizing Process and Applying to Pack Carburizing Process

Wanna Homjabok — 2024-06-30

The purpose of this article review was to compile contents and factors which affected the spheroidizing process, carburizing process, and carburizing process followed by the spheroidizing process for utilization in industrial, and academic matters. The findings of this study revealed that there were many methods for the spheroidizing process with the most used process being used with the cycle temperature at slightly lower and higher A₁ temperature. The number of sequences of increased temperature found lighter cementite which had higher ultimate tensile strength, yield strength, and percent elongation. The essential factors in the pack carburizing process were composed of types of charcoal, catalyst, temperature, and time. The best charcoals to extend carbon were from eucalyptus, tamarind, the rootstock of cassava, coconut shell, and bamboo respectively. The study showed that calcium carbonate (CaCO₃, commercial-grade) was the best catalyst along with the catalyst in calcium carbonate from nature. The temperature and time in the process affected carbon diffused to sample well, increased hardness, and reduced the efficiency of impact. Moreover, spheroidizing was used after finishing carburizing process, discovering the cementite network where the surface changed to a sphere shape but with the properties of toughness and elasticity still high. After carburizing process, the sample had increased hardness but after the spheroidizing process the hardness decreased. Time studies showed that a longer period in the spheroidizing process, led to lower hardness and increased impact.