RMUTL Engineering Journal

Influence of Durian Rind Cellulose Microfiber as the Fillers on the Mechanical Properties of Polylactic Acid Bio-composites

Watcharin Sitticharoen — 2024-12-03

This work aims to study the influence of durian rind cellulose (DRC) microfiber as a reinforcing filler on the mechanical properties of polylactic acid (PLA) bio-composites. Cellulose from durian rind will be extracted using sodium hydroxide solution and bleached treatment with hydrogen peroxide. X-Ray fluorescence technique was used to examine the chemical composition of durian rind cellulose, and functional groups were analyzed using FT-IR technique. PLA was mixed with DRC microfibers particle size of 300 μm by using a mixing apparatus, and then melt-blending by extruder in varying ratios of 100/0, 95/5, 93/7, 90/10, and 80/20wt%. The results revealed that the mechanical properties of PLA/DRC composites in the tensile modulus, flexural modulus, and shore-D hardness of the composites at DRC microfibers of 20 wt% was increased a maximum of 64%, 21%, and 16%, respectively, as compared to the neat PLA. On the other hand, the tensile strength, and flexural strength of the composites at DRC microfibers of 20 wt% was depressed by 9%, and 23%, respectively, as compared to the neat PLA. Polymer composites reinforced with DRC microfiber had increased water absorption when increasing DRC microfiber particles. PLA biocomposites as a new eco-friendly alternative material, and can be used to as compostable chopsticks.

Adsorption characteristics of methylene blue onto low-cost dried and calcined water hyacinth: A batch and fixed-bed column study

nakorn suriyanon — 2024-12-03

This study investigated the potential of using two types of water hyacinth as adsorbents for removing Methylene Blue (MB) from aqueous solutions. The Langmuir isotherm model best fits the adsorption isotherm data, with Dried Water Hyacinth (DWH) performing better than Calcined Water Hyacinth (CWH). The modeling data breakthrough curve indicated that DWH and CWH followed pseudo-second-order kinetics monolayer chemical sorption. Even though DWH has a lower adsorption capacity than activated carbon and other expensive adsorbents, it is comparable to, or performed better than other low-cost adsorbents.

Comparison of Polypropylene Flow Index to Increase Injection Efficiency In Plastic Injection Mold, 2 Cavities of Different Shapes Plastic (Case Study : Pencil Box)

Worapong Phongphattarawut — 2024-12-03

This research used a computer program to simulate the flow, experimental design and statistical analysis to find the right parameters and properties of polypropylene to fix the problem of the injection of molded plastic with two cavities, when the shape is different and the time to fill a minimum of two different indicators to the cavities. The results of the experiment; plastic polymer polypropylene grade RJ6420 is more suitable for forming injection molded plastic pencil boxes than grade RP348S due to the flow characteristics when observing and recording the time to fill the two cavities. And has filled different than 0.0097 seconds to molding. The real piece of work is complete.

Soil pH and Nutrient Analyzer for Selecting Suitable Economic Crops

Suparoek Junsupasen — 2024-12-03

This paper focuses on developing a soil pH and nutrient analyzer prototype designed to aid in the selection of economically viable crops in Thailand. The analysis includes assessing soil pH and the primary nutrients (NPK) to evaluate the soil quality for the cultivation of economically important crops in Thailand. These economic crops consist of rice, cassava, sugarcane, rubber, and palm oil. This analyzer aims to provide farmers with tools that enhance efficiency in cultivation, specifically in soil preparation before planting or selecting crops that are suitable for the specific soil conditions in the area. The soil pH and NPK sensors that have undergone preliminary accuracy calibration are utilized for soil quality assessment. The measured results of sensors are sent to a microcontroller for analysis of soil pH and NPK values to determine their suitability for cultivating economically important crops in Thailand, including rice, cassava, sugarcane, rubber, and palm oil. A pH buffer solution and NPK colorimetric test strips are used for preliminary calibration of the sensors measuring pH and NPK, respectively. The preliminary calibration results indicated that the average error for pH calibration was 9.48%. For the calibration of soil NPK, the average values for nitrogen (N), phosphorus (P), and potassium (K) were 162.4 mg/kg, 66 mg/kg, and 60.6 mg/kg, respectively. These values were within the range of the pH buffer solution kit and the NPK colorimetric test strip. The soil pH and NPK values obtained from the measurements were analyzed the suitability of the soil for cultivating the five economically important crops. Consequently, farmers can conveniently prepare the soil before planting or select suitable crops for specific soil conditions using the proposed soil pH and nutrient analyzer. This analyzer tool enhances the efficiency of Thai farmers in cultivation.

The increasing Machine Availability of the Water Filtration Process in the Water Production Process: A Case Study of Mahasawat Water Treatment Plant

Sirawit Pussawiro — 2024-12-03

The network of water production to supply Bangkok, Nonthaburi, and Samutprakarn, with 6,300,000 cubic meters per day, found raw water quality problems from saltwater encroachment, poor-quality water, and clogged algae. problems affected the water plants cannot produce water with total planned. The Mahasawat water treatment plant has no problems with raw water quality. that is necessary to maintain the stability of the water supply process. Recently, there is a growing issue of machinery damage that diminishes capacity of the water production process. This research demonstrated the improvement of machinery availability for water filtration in the water production process. This research was investigated the cause of machine damage, the relationship between machine damage and the six big losses in each system of the water filtration and determined, the equation for the capacity and improved approach. The results showed that the machinery capacity of the water filtration process increased by 0.30%, 1.29%, 1.97%, and 4.95%, and the water production capacity increased by 9,401.55 cubic meters/day, 12,675.18 cubic meters/day, 15,041.94 cubic meters/day, and 23,290.99 cubic meters/day.

Influence of Fineness Modulus Values, Polypropylene Fibers Contents, and Air Foam Contents on Dry Unit Weight and Strengths of Lightweight Geopolymer Reinforced Polypropylene Fibers

Piyathida Yoosuk — 2024-12-03

This paper investigated the influence of fineness modulus on dry weight, compressive strength and flexural strength of lightweight geopolymer reinforced polypropylene fibers. Geopolymer fly ash was used as a cementitious material. The fineness modulus of sand was determined at 1.6, 1.45, and 1.3, polypropylene fibers contents of 0, 0.5, 1, 1.5, 2, 2.5, and 3% by weight of fly ash, air foam contents (AF) of 0, 1, and 2% by weight of binder, fly ash to sand ratio was 1, the alkaline solution to binder ratio was 0.55, and the sodium silicate (Na2SiO3) to sodium hydroxide solution (NaOH) was 50:50. The results showed that the dry weight decreased with increasing polypropylene fiber contents and air foam contents. The lowest dry weight was found at a fineness modulus of 1.6, a polypropylene fiber content of 3% by weight of fly ash, and an air foam content of 2% by weight of binder. The maximum compressive strength and flexural strength were found at a fineness modulus of 1.45. The flexural strength increased by the enhancement of polypropylene fiber content due to fiber-controlling cracks and reduced crack width. The flexural strength decreased by increasing the polypropylene fiber contents up to 3% by weight of fly ash because the excess fibers induced the friction in sample. The dry weight and compressive strength of lightweight geopolymer reinforced polypropylene fibers was by the Thai Industrial Standards (TIS 2601-2013). The dry weight was between 701-1,600 kg/m3 and the compressive strength was more than 5.0 MPa (51.0 kg/cm2).

The Evaluation of the Performance and Economics of Solar Tracking System for Bifacial Solar Panel

Jirayu Beangthit — 2024-12-03

This research assessed the performance and economic viability of a bifacial solar tracking system for a 430 Wp solar panel. The system was designed and tested using an iterative process to adjust the panel tilt angle based on specified conditions. The performance evaluation of the solar tracking system for the bifacial solar panel revealed a 2.31% error in the designed and installed systems. The tracked system achieved a maximum power output of 364.20 W with a power generation efficiency of 13.01%, compared to the non-tracked system that produced a maximum power of 360.42 W with an efficiency of 12.05%. The capacity of electric generation from the 1 MW two-side solar cell system was determined the established equations. From the result, the solar tracking system produced 1,758.78 MWh/year, higher than the without-tracking system with 1,579.41 MWh/year. In terms of economic viability, the solar tracking system provided a payback period of 7.01 years, longer than the without-tracking system with a payback period of 6.38 years. The net present values were 11,910,512.54 Baht and 14,692,713.81 Baht for the tracking and without-tracking systems, respectively, with internal rates of return of 10.80% and 12.80%, respectively.