Naresuan University Journal
Not a member yet
39887 research outputs found
Sort by
Fatty Acids and an Ester from the Leaves of Millettia utilis Dunn
Get PDF Two fatty acids, palmitic acid and oleic acid together with an ester, methyl oleate were isolated from dichloromethane crude extract from the leaves of Millettia utilis Dunn. The structures of all isolated compounds were elucidated by basic NMR spectroscopy and compared with previous literature. All compounds were tested for their antioxidant activities. Oleic acid revealed weak activity against ABTS assay with IC50 = 39.50 mg/mL.
Keywords: Millettia utilis Dunn, fatty acids, an ester, ABTS, antioxidant activitie
Synthesis and Application of Cuprous oxide-Potassium Lithium Titanate Composites in the Photocatalytic Degradation of Rhodamine 6G
No full text The cuprous oxide-potassium lithium titanate composites were prepared by a conventional solid-liquid reaction between potassium lithium titanate (KTLO) and copper acetate subsequent precipitation with sodium hydroxide and glucose. The cuprous oxide-potassium lithium titanate composites were characterized by X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy and UV-Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of the cuprous oxide-potassium lithium titanate composites with different cuprous oxide and potassium lithium titanate loading was evaluated in the photocatalytic degradation of rhodamine 6G under visible light irradiation. The composite which containing lower loading amount of cuprous oxide than potassium lithium titanate showed 82% of photodegradation of rhodamine 6G. The cuprous oxide-potassium lithium titanate composite is eco-friendly material with the performance as photocatalysts under solar light.
Keywords: Composite, Potassium lithium titanate, Cuprous oxide, Photocatalysis, Rhodamine
Equilibrium, Kinetics, and Thermodynamic Studies Concerning the Removal of 2–chlorophenol Using Chemically Carbonized Rice Husk Waste
Get PDF In this work, the adsorption of a harmful pollutant, 2–chlorophenol, from aqueous solution onto carbonized rice husk (C–RH) was investigated. Highly-porous adsorbent C–RH was produced in this study using chemical activation with hydrochloric acid, followed by carbonization at 550°C. The surface morphology of C–RH by scanning electron microscope (SEM) and BET N2 adsorption/desorption techniques showed that the results of C–RH characterization had a pore volume of 0.042 cm3/g and BET surface area of 278.90 m2/g due to the resulting silicon element contained in rice husk ash. Pore size distribution having a clear hysteresis loop belongs to type IV isotherm nature with H3–type of hysteresis loop, which is distributed by pores mainly in the mesoporous range. The batch adsorption experiments showed that the equilibrium uptake was increased with an increase in initial 2–chlorophenol concentration. The experimental isotherm data fit better with the Freundlich isotherm model, which followed an ideal multilayer adsorption with the maximum monolayer adsorption capacity (Nm) of 13.4048 mg/g obtained by Langmuir. Kinetic data was best fit to a pseudo–second order rate equation, indicating chemisorption. Thermodynamic parameter in terms of ΔGo for the adsorption showed that adsorption on the surface of C–RH at 304.15 K was spontaneous in nature. Consequently, C-RH produced from rice husk waste has the potential to serve as an alternative to commercial activated carbon for water treatment.
Keywords: Mesopore, Rice husk, Freundlich model, Adsorption, 2–chloropheno
The Development of Soil Moisture Control System based on Wireless Communication Technology for Off-Season Durian Production in Nopphitam District, Nakhon Si Thammarat Province, Thailand
No full text This study is a part of the research granted by the National Research Council of Thailand (NRCT). In this first stage, the study aimed to design and develop wireless communication system collecting data concerning soil moisture, light, temperature and humidity in the experimental off-season durian plantation. According to the experimental off-season durian plantation investigation, durian planting was divided into four phases. The site preparation phase started from January to April. From May to June was the controlling phase. Later, the pruning phase started from July to November and, finally, the harvesting phase was from December to January. Soil moisture analysis in those four periods found an average soil moisture content of 65 %. However, in April, soil water decreased by an average of 20 %. Therefore, irrigation was required to promote normal growth of durian. During the irrigation, temperature dropped and humidity increased by an average of 5%. All of these results will be used to develop soil moisture control system in the next stage.
Keywords: Off-Season Durian, Soil Moisture, Wireless Communication, Measurement and Control Syste
The Implement of Vehicle Blind Spot Detection System Using SDSoC
No full text Embedded system and image processing is the technology used to apply for designing systems to facilitate drivers in the future by replacing wing mirrors with the camera to detect objects at the blind spot at the back. When the object is detected within the blind spot zone, the system is alarm drivers. These are a concept of The blind spot detection vehicle system (BSDS). This research presents BSDS to help drivers, which is designed on Field Programmable Gate Array (FPGA). There are two main modules for creating. The first module is pre-processing image using grayscale to resize the dataset in terms of the bit stream in every pixel and region-of-interest (ROI) for specifying the area of pixels wanted to reduce the noise of the data set or data quantity that needs to use in calculation. The second module is vehicle detection and alarm by Sobel operator for object and shadow detection to detect the shadow of the vehicle and confirm the existence of it. This research shows details of each algorithm, flow chart, and effectiveness of vehicle detection. This idea has been designed and developed by a software called Software-Defined System-On-Chip (SDSoC) on the Zybo board. In conclusion, the system can detect vehicles at resolution 1920*1080 within 12 ms/frame and accuracy of vehicle detection at 100% recall.
Keywords: SDSoC, FPGA, BSDS, image-processing, pre-processing image, region-of-interest, Sobel operator, shadow detectio