Suranaree Journal of Science and Technology

PERFORMANCE ANALYSIS OF WIDE BANDGAP GAN BASED INTERLEAVED CONVERTER FOR CPU VOLTAGE REGULATOR APPLICATIONS

Ravindranath Tagore Yadlapalli — Tue, 26 Nov 2024 00:00:00 +0700

Nowadays, the central processing unit (CPU) of laptop computer operates at very high clock frequencies (GHz) with abrupt load transitions. Therefore, it necessitates an efficient voltage regulator in order to realize the rapid CPU dynamics. In view of this, this paper presents a 4-phase interleaved synchronous buck converter (ISBC) for the CPU applications. It has the exceptional features such as input and output current ripple cancellation, good thermal performance, higher power, current and efficiency. The design of a 9~19 V input, 1 V/45 A, 300 kHz ISBC is accomplished as a CPU voltage regulator. The performance of the converter is interpreted for the line and load regulations based on the voltage mode hysteretic controller. The elaborative PSIM simulation results are presented in view of emphasizing the strength of this controller. Moreover, the efficiency analysis of the Si devices as well as GaN devices based interleaved converter is explored in detail. The GaN devices can ameliorate the power density (PD) as well as efficiency of the ISBC. It also highlights the importance of the switching frequency selection and optimization for the ISBC.

LEVY BASED PHRYNOSOMA DOUGLASSII SWARM, ALASHAN WAPITI OPTIMIZATION, FOREST PONY ALGORITHM AND PANTHERA TIGRIS CORBETTI SEARCH FOR TRUE POWER LOSS REDUCTION IN ELECTRICAL SYSTEM

Lenin Kanagasabai — Tue, 26 Nov 2024 00:00:00 +0700

Lévy based Phrynosoma douglassii inspired optimization (LPD) algorithm, Alashan wapiti optimization (AWO) algorithm, Forest Pony Optimization (FPO) algorithm and Panthera Tigris corbetti optimization (PTC) algorithm are applied to solve the true power loss reduction problem. Camouflage, colour changing, blood spouting and squirt out protection methods of Phrynosoma douglassii are scientifically formulated in the LPD algorithm. Due to Camouflage action, Phrynosoma douglassii alter its body colorant by flattering luminous to evade exposure to the predators. AWO algorithm is formulated based on the natural breeding procedure of Alashan wapiti. There are dual key breeding periods for Alashan wapiti. In the rutting season Alashan wapiti herd alienated into dissimilar folks of numerous proportions. FP algorithm replicates the foraging area nearby Forest Pony with coefficient and scientific execution of foraging. Forest Ponies from upper layer of the organized matrix are designated as Alpha cluster of Forest Ponies. In PTC, during initial period, the location of population associates is rationalized grounded on picking and bout on the prey. This period sources abrupt and widespread vicissitudes in the location of population associates, and as a consequence, it upsurges the aptitude of the global examination and exploration of the procedure in precise glance over of the examination region. Lévy based Phrynosoma douglassii inspired optimization (LPD) algorithm, Alashan wapiti optimization (AWO) algorithm, Forest Pony Optimization (FPO) algorithm and Panthera Tigris corbetti optimization (PTC) algorithm are validated in IEEE 118, 300, 354 systems.

STRUCTURAL AND OPTICAL MODIFICATIONS IN BOROTELLURITE GLASS BY DYSPROSIUM DOPING

Seubsakun Khondara, Patarawagee Yasaka, Warawut Sa-ardsin, Narong Sangwaranatee — Wed, 11 Dec 2024 00:00:00 +0700

This study investigates the luminescence and physical properties of dysprosium doped borotellurite glass with the composition: (40-x)TeO₂ -35B₂O₃ - 5CaO - 15ZnO - 5Nb₂O₅ - xDy₂O₃ (while x is 0, 0.1, 0.5, 1.0, 1.5 mol%). The glass samples were synthesized using a conventional melt-quenching technique. Characterization techniques, including X-ray diffraction (XRD), optical absorption, and photoluminescence spectroscopy, were employed to analyze the properties of the prepared glasses. XRD confirmed the amorphous nature of the samples. FTIR measurements revealed structural insights into the borotellurite network with the existence of TeO₄, BO₄, and BO₃. Optical absorption spectra displayed characteristic absorption bands associated with Dy³⁺ ions. Under excitation with the light at 388 nm, the glasses exhibited intense yellow (576 nm) and blue (482 nm) emissions corresponding to the transitions: ⁴F_9/2 → ⁶H_13/2and ⁴F_9/2 → ⁶H_15/2, respectively. The physical properties, such as density and refractive index were also determined. The results demonstrate the potential of Dy-doped borotellurite glasses as promising materials for optical applications, especially within the development of white light-emitting diodes.

THE MINIMUM SCORE PREDICTION FOR CONSORTIUM OF THAI MEDICAL SCHOOLS (COTMES) FACULTY QUALIFICATION BY N-METHOD IN YEAR 2021-2023

Ruethaichanok Kasatecharoen, Padungsak Kasatecharoen — Mon, 02 Dec 2024 00:00:00 +0700

Thai university Central Admission System (TCAS) is developed for all high school students in Thailand. There are four rounds of TCAS called, portfolio, quota, admission and direct admission. The admission round is the round that use the score of each test subject to compute the total score, and then apply to TCAS. Consortium of Thai Medical Schools (COTMES) is a group of the Faculty of Medicine, Dentistry, Veterinary Medicine and Pharmacy for selecting students through the admission round of TCAS system by using the same score criteria. The minimum score that can qualify the admission is the main point. However, the last year minimum score cannot be used directly because of the difficulty of the tests in each year. The researchers have developed a model called 𝑚𝑒𝑎𝑛 + 𝑁(𝑠. 𝑑.) model or N-Method to predict the minimum score of COTMES faculties. The results show that the error means of the year 2021,2022 and 2023 of all majors are between -0.7645 and +1.4505. For only Faculty of Medicine, the error means are between -0.6477 and +1.9227. Faculty of Dentistry, similar result to Faculty of Medicine, the error means are between -0.5388 and +1.2261. For Faculty of Veterinary Medicine and Faculty of Pharmacy, the error means are from -2.8003 to +3.3976 and from -4.0377 to 4.7310 respectively.

NOVEL MATE PREFERENCES IN HUMAN BEINGS INSPIRED OPTIMIZATION AND HYBRIDIZED POMSKY - PYGOSCELIS ANTARCTICUS - PHENGODES SWARM ALGORITHM

Lenin Kanagasabai — Mon, 25 Nov 2024 00:00:00 +0700

Mate Preferences in Human beings inspired Optimization (MPHO) Algorithm and Hybridized Pomsky -Pygoscelis antarcticus - Phengodes Swarm algorithm (HPPP) are applied for solving the genuine power loss reduction problem. Mate Preferences in Human beings inspired Optimization Algorithm has been designed mathematically based on the mate preferences in Human beings. Criteria of selecting the mate may be depending on social and economic conditions, physical attractiveness, stable and intellectual deeds. This action is scientifically demarcated in the exploration section of the procedure. In the exploitation division, both men and women analyze about the conditions in intensified mode before making a final decision. Pomsky Optimization Algorithm is based on the skilled movement of the Pomsky in examining process. Extraordinary snort possessed by Pomsky through which it can identify the various aromas and by level of barking will disclose about the intimacy near the examining entity. Pygoscelis antarcticus Optimization algorithm is designed by Pygoscelis antarcticus clustering behaviour. In foraging Pygoscelis antarcticus moves in cluster or group. Phengodes swarm optimization algorithm is a new algorithm which stimulated from the light emission behavior of glow worms to attract prey. Phengodes Swarm Optimization Algorithm incorporated with the parallel hybrid mutation which unites the uniform distribution mutation with the Gaussian distribution mutation. In hybridized Pomsky - Pygoscelis antarcticus - Phengodes Swarm (HPPP) algorithm, course of iterations and extraordinary degree of divergence will be there with the orientation of amplification.

APPLICATION OF MICROBIALLY INDUCED CALCITE PRECIPITATION TO IMPROVE POORLY GRADED SANDY SOIL

RADHA BORUAH, BERLIN MOHANADHAS, JAYAKESH K — Tue, 26 Nov 2024 00:00:00 +0700

The challenges associated with improving or strengthening poor soil consistently necessitated investigation to establish a novel, environmentally acceptable, and sustainable soil improvement method. The MICP (microbially induced carbonate precipitation) approach is one method in which microorganism metabolic pathways are used to create calcite precipitation inside the soil matrix, improving soil engineering qualities. This study aims to examine the efficiency of the MICP approach in improving the California Bearing Ratio value and reduction in permeability of poorly graded sand. Aerobic bacteria, namely Bacillus Subtilis, was used in this investigation for ureolysis and calcite precipitation. Three distinct concentrations of urea-calcium chloride solution (50, 300, and 600 mmol/L) treatment conditions were explored in the experimental program, and the California Bearing Ratio (CBR) value and permeability of the soil was determined for the targeted soil. This investigation indicated that the MICP has caused a significant quantity of calcite precipitation, resulting in a substantial improvement in the strength and a reduced permeability of the poorly graded sandy soil. Scanning electron microscopy (SEM) examination testing of the produced CaCO₃crystals indicated that the CaCO₃ predominantly created connections from point to point between the particles of sand throughout the process of precipitation.

GREEN SYNTHESIS, CHARACTERISATION, MIC, AND BIOACTIVITY OF DOPED COBALT METAL TARTRATE COMPLEXES

Thu, 17 Oct 2024 00:00:00 +0700

Novel mixed transition metal complexes MnCo2(C4H4O6)36H2O and NiCo2(C4H4O6)36H2O are synthesized using green approach, these tartrate act as a bidentate ligand. For characterisation of complexes elemental analysis, FTIR, XRD, TGA, and SEM with EDAX techniques were used. Analytical data shows that all complexes exhibited 1:1 (metal: ligand) ratio. IR spectral data shows that bidentate ligand coordinate with metal ion as bidentate ligand through the two ‘O’ atoms. The TGA of the complexes showed good agreement with their suggested formulae. XRD technique shows that all the complexes found to be in polycrystalline nature. SEM shows morphological features and surface characteristics of complexes. The synthesised complexes tested for antibacterial and antifungal activity to check the physiological activity and characterized for its application in the synthesis of heterocyclic compounds as catalysts.

APPLICATION OF STATISTICAL TECHNIQUES FOR TESTING SOIL MOISTURE MEASUREMENT WITH STAINLESS STEEL TUBE SENSORS

Atirat Maksuwan , Arpapong Changjan, Nuttakorn Intaravicha, Phanuchai Pramuanl — Mon, 18 Nov 2024 00:00:00 +0700

Soil moisture measurement with advanced analytical tools is expensive and complicated. A simple soil moisture sensor was created using the capacitance between two parallel rods, which can be measured using stainless steel tubes. The statistical significance of differences in measurement testing requires studies. In this work, we introduced analysis of variance and correlation approaches to assess the statistical significance of differences between systematic effects and errors resulting from environmental parameter variation. Comparisons of the obtained results with effects and errors resulting from environmental parameter variation data on the capacitance between the two parallel rod sensors were presented. This statistically significant approach contributes to efficient and low-cost estimations of soil moisture and understandings of soil moisture based on environmental parameters.

LONG-TERM BENEFITS OF REMANUFACTURED ELECTRIC VEHICLE BATTERY: A CASE OF THAILAND

Thanwadee Chinda, Anatawat Chayutthanabun — Wed, 13 Nov 2024 00:00:00 +0700

Battery electric vehicle (BEV) is a potential solution to mitigate the environmental impacts for the automotive industry. However, the high BEV demand results in high electric vehicle battery (EVB) production and retired EVBs. This study utilizes the system dynamic modelling approach to explore the growth of BEV market based on key factors, namely the loan payment, fast charging station, driving range, available model, subsidy, tax reduction, and parking privilege. Benefits and costs of the remanufactured EVBs are then calculated to examine the feasibility of the EVB remanufacturing project. The simulation results reveal that providing parking privileges to the BEV users raise the BEV demand by 20.5%. The EVB remanufacturing project is feasible in seven years with the minimum acceptable internal rate return (IRR) of 18.49%. The sensitivity analysis results show that the IRR values increase to almost 65% at the end of year 25 when the selling prices of the remanufactured EVBs are as new and the remanufacturing costs are reduced by half. The simulation results offer insights to the Thai automotive industry and government to make strategies to promote the sustainable practices of the BEV and EVB industries.

HEALTH RISK RELATED TO URANIUM-238 INTAKE IN MAIZE

Phatchada Nochit, Wutthikrai Kulsawat, Ritiron Samran — Thu, 31 Oct 2024 00:00:00 +0700

The regular use of phosphate fertilizer in maize crops may increase ²³⁸U, the long-lived radionuclide, in agricultural soils. Maize simply accumulated ²³⁸U during growth and development. In this study, ²³⁸U concentrations were determined in sweet corn or yellow maize (Zea mays saccharata) and flour corn or white maize (Zea mays amylocea) using radioanalytical technique and alpha spectrometry. Samples were collected from maize fields in Mae Ramat district, Tak province in 2018-2019. Health risk of children, juvenile and adults as consumers related to radiation dose and risk of fatal and illness cancer were evaluated. Concentrations of ²³⁸U in all investigated samples were found to be generally low, range from 4.98 to 7.47 Bq.kg^-1 ww. in sweet corn and from 6.41 to 10.29 Bq.kg^-1 ww. in flour corn which was below the average world value for ²³⁸U in all food types of 35 Bq.kg^-1. Annual committed effective doses due to ²³⁸U intakes as a result of sweet corn and flour corn consumption for children, juveniles, and adults were 13.91 ± 1.47, 78.18 ± 3.48, and 34.05 ± 2.29 µSv.y^-1, respectively. These individual doses were below the UNSCEAR recommended limit of 120 µSv.y^-1. The lifetime cancer risks varied from 1.05 × 10^-5 to 2.18 × 10^-5 for fatal cancer and 1.61 × 10^-5 to 3.34 × 10^-5 for illness cancer. These were relatively low compared with the ICRP recommendation risk of 2.5 × 10^-3. Results presented herein suggest no health risk effect to consumers related to the intake of ²³⁸U from sweet corn and flour corn.

OUT-OF-PLANE BENDING STRENGTH OF LIGHTWEIGHT MASONRY WALLS STRENGTHENED BY COCONUT ROPE NETTING

Phaiboon Panyakapo, Lawan Kankaset — Mon, 25 Nov 2024 00:00:00 +0700

This paper presents the effectiveness of employing of coconut rope netting reinforcement on lightweight brick masonry walls. The lightweight brick was developed with a mixed design of cement: sand: coconut fiber: water: foam of 1.0:0.985:1.5:0.55:0.007 by weight. The strengthened wall panels were prepared by applying coconut rope netting with various external reinforcing patterns to the walls. Four types of coconut rope netting were employed to examine the effects of reinforcement ratio. The performance of the walls reinforced with coconut fiber was assessed by conducting experimental tests. This was to measure the out-of-plane bending strength, the deformation capacity, and the features of the failure. The test result indicated that the primary cause of failure for coconut fiber reinforced masonry walls is the flexural instability, which leads to the formation of small-scale crack patterns in the walls. The highest improvement was achieved when the reinforcement ratio reached 5.5%. This resulted in a significant increase of 114.97% and 44% in the load-bearing capacity and the ductility index, respectively. The comparisons between the experimental and the analytical results for the out-of-plane bending resistant of the walls revealed that the suggested analytical model offers a reasonable estimation. Hence, the utilization of coconut rope netting demonstrates the satisfactory enhancement, and it contributes to the advancement of sustainable and cost-effective construction technique.

STATISTICAL PROFILING OF GROUNDWATER: UNVEILING PATTERNS AND QUALITY INDICATORS FOR SAFE DRINKING

Kiran V. Mehta — Wed, 11 Dec 2024 00:00:00 +0700

This study uses physicochemical analysis to assess groundwater samples for drinking water quality. Samples of groundwater were taken from rural regions of Tharad taluka [Banaskantha district of Gujarat state of India]. The evaluation encompassed a comprehensive analysis of various parameters to assess drinking water quality in the specified region. Parameters such as temperature, color, odor, turbidity, electrical conductivity (E.C.), pH, total dissolved solids (TDS), total alkalinity (T.A.), and concentrations of ions including fluoride, chloride, calcium, magnesium, sodium, and potassium were thoroughly examined. This approach provides a detailed understanding of the overall water quality profile in the designated area. The results obtained were judged against the drinking water guidelines given by Indian Council of Medical Research (ICMR). Total dissolved solids measurements in the samples indicate that the water is unsuitable for consumption. So, water needs to be adequately treated before being used for drinking. For statistical analysis, Pearson Correlation Coefficient was used to analyze physico-chemical parameters. It indicates that turbidity is strongly related to several parameters, including total dissolved solids, electrical conductivity, and fluoride concentration.

SOIL SALINITY STATUS IN NAMANGAN REGION, UZBEKISTAN

Wed, 11 Dec 2024 00:00:00 +0700

Understanding soil salinity levels is essential for effective agricultural planning and, consequently, for ensuring food security and sustainability. However, poor practices have significantly impacted soil salinity levels in many developing countries. In Uzbekistan, soil salinity levels have not been adequately assessed and documented over the past decades, leading to adverse effects on agricultural food production. This paper presents a first attempt to systematically document soil salinity levels in the Namangan area of Uzbekistan. Data on soil salinity from the last 22 years (2000-2022) were obtained from the Namangan Regional Department of Agriculture. Additionally, soil samples from the Uychti district of Namangan, collected in 2013, 2014, and 2017, underwent thorough laboratory analysis. Documented soil salinity levels in the Namangan region highlight a need for significant attention to mitigate these impacts. Experimental findings demonstrate the effectiveness of mulching agro-technologies in reducing soil salinity. However, a comprehensive assessment and an adaptive approach to mitigate soil salinity in the Namangan region are urgently needed to ensure long-term agricultural productivity.

ENHANCING THE COMPRESSIVE STRENGTH OF HEMP FIBER REINFORCED CEMENT AND EVALUATING THERMAL PROTECTION PERFORMANCE

Sudniran Phetcharat, Rongarun Buntan, Pagornphat Budcha, Rungroj Ruekrai — Tue, 26 Nov 2024 00:00:00 +0700

This research aimed to enhance the properties of hemp concrete to comply with the non-load bearing block according to the standard criteria TIS 58-2533. Samples of hemp concrete blocks measuring 7.5×7.5×10 cm were produced with varying compositions of hemp ranging from 0-14.29% by weight of dry aggregate. Properties of hemp concrete were improved using Al₂(SO₄)₃, plasticizers, natural rubber, and polymers. Testing included compressive strength, dry density, water absorption, and calculation of the OTTV compared to standards set by the Ministry of Energy. Hemp concrete without property enhancement additives consistently exhibited lower compressive strength than 2.5 MPa. Enhancing hemp concrete with 20% Al₂(SO₄)₃by weight of hemp, combined with polymer, yielded the highest compressive strength compared to other methods. Hemp concrete with 9.09% and 14.29% hemp by weight of dry aggregate, enhanced with 20% Al₂(SO₄)₃ by weight of hemp and 50% polymer by weight of water used for mixing mortar, exhibited compressive strengths of 3.41 MPa and 2.62 MPa, respectively. Water absorption were 377 kg/m³ and 407 kg/m³, and dry densities were 0.98 g/cm³ and 0.90 g/cm³, respectively. Both samples achieved OTTV less than 50 w/m². From this research, the production process of hemp concrete with 9.09% and 14.29% hemp by weight of dry aggregate was enhanced with 20% Al₂(SO₄)₃ by weight of hemp, and polymer was combined by 50% by weight of water used for mixing mortar. This resulted in a material with compressive strengths comparable to non-load bearing block and suitable for energy-efficient construction, particularly in office buildings.

EFFECTS OF MOLECULAR CHAIN COVERAGE AND MOLECULAR CHAIN LENGTH ON STRENGTH AND PACKING OF SURFACE COATING MATERIALS: DFT CALCULATIONS

Pipat Khongpracha, Prapasiri Pongprayoon, Chaiya Prasittichai, Somkiat Nokbin — Wed, 11 Dec 2024 00:00:00 +0700

Self-assembled monolayers (SAMs) on an SiO₂ surface were investigated using periodic DFT calculations. The stability of SAMs on SiO₂ surfaces was influenced by modifications in head groups, coverage, and space group length. Three molecules were considered as trial molecular chains: methyltrichlorosilane (CH₃SiCl₃), acetyl chloride (CH₃COCl), and methylphosphonic acid (CH₃PO(OH)₂), with CH₃SiCl₃ being chosen because of the stable chemisorption complex of its -SiCl₃functional group to the surface and the nonpolar hydrophobic nature of CH₃. The stability of each SAM was evaluated using the molecular chain length in terms of CH₃(CH₂)_nSiCl₃, where n = 0-9, and three distinct coverages (1/4, 1/2, and 1 ML). Our findings revealed that coverage and molecular chain length had a major influence on SAM stability, with van der Waals interactions outweighing steric interactions during molecular chain lengthening.

AN INTELLIGENT CONTROLLED TRACKING OF POINT OF MAXIMUM POWER IN STANDALONE PV SYSTEM UNDER REALISTIC VARYING IRRADIATIONS

Shilpa Saxena, Vijay Kumar Tayal, Hemender Pal Singh, Vinod Kumar Yadav — Tue, 26 Nov 2024 00:00:00 +0700

Owing to the proven footmark for the clean, green energy, compact in size, cost effective and ease of availability of sunlight, applications of photovoltaic (PV) panels are continuously on rise. However, the low conversion efficiency is a major concern for researchers. The conversion efficiency may be improved significantly if PV panels are operating on maximum power point. Solar irradiations received by PV panel are not constant always. The irradiation may be linear and nonlinear, fast, slow and sudden varying in nature. Thus, tracking of maximum power point is a huge challenge. This irregular behaviour of incident irradiations may result in oscillations in output and low conversion efficiency. In order to enhance the performance, a suitably designed controller, operating at maximum power point is needed. This paper highlights maximum power point tracking under varying irradiation conditions (viz. Step Variable Irradiance and Ropp’s irradiance profile) using two control techniques namely Perturb and Observe (P&O) and Incremental Conductance (IC). The simulation results obtained for two control techniques are compared for system efficiency, tracking of maximum power point and enhancement of voltage. The comparison of results reveals that there is far better improvement in overall efficiency, output power, output voltage and faster regaining of the maximum power point path with IC technique as compared to P&O technique. Thus, IC control technique excellently tracks maximum power point with reduced probability of deviation and better oscillation damping under varying incident irradiations.

ADVANCED DAMAGE DETECTION IN REINFORCED CONCRETE APPLYING ACOUSTIC EMISSION, WAVELET TRANSFORM AND SHANNON ENTROPY

SOUMYADIP DAS, Aloke Kumar Datta, Pijush Topdar, Sanjay Sengupta — Tue, 03 Dec 2024 00:00:00 +0700

Concrete structures are extensively used in infrastructure but are susceptible to deterioration due to external loads, fatigue, and environmental factors. Early damage detection is vital for effective monitoring and failure prevention. Continuous sensor-based health monitoring can extend the design life of these structures. Acoustic Emission (AE) is a promising non-destructive testing technique for assessing damage in concrete, as it captures signals generated by microcrack formation and propagation. AE sensors detect these signals, which can be analyzed using wavelet transform (WT) in the time-frequency domain. Additionally, changes in the Shannon entropy of AE signals can indicate the presence and severity of damage in concrete. This study explores the effectiveness of combining WT and Shannon entropy for detecting damage in concrete structures using AE signals. Concrete specimens were subjected to simulated damage using pencil-lead break (PLB) tests, and the resulting AE signals were recorded. The WT was applied to decompose the AE signals into time-frequency components, facilitating the identification of damage-induced frequency bands. Shannon entropy was then calculated for each decomposed frequency band to measure the randomness or disorder within the signal. The results are expected to show that damage initiation and progression are reflected in changes in the frequency content and entropy of AE signals. An increase in entropy in specific WT frequency bands is anticipated to correlate with the presence and severity of damage in the concrete. This study aims to establish a different method for the localization of damage in concrete using a combination of WT and Shannon entropy analysis of AE signals.

EVALUATION OF PET SHEET DEGRADATION USING THERMOPHILIC GEOBACILLUS SP. PT206

Wed, 11 Dec 2024 00:00:00 +0700

This research aimed to evaluate the degradation of Polyethylene terephthalate (PET) sheet using the thermophilic Geobacillus sp. PT206 isolated from the landfill site at Saraburi province. Strain PT206 gave the highest Hydrolytic Capacity on MSM with BHET, at 29.1 ± 14.0. PET degradation was evaluated in biometer flasks containing Bushnell Haas Broth with PT206 at 55°C for 1 month. Optical density was measured every 7 days to monitor the bacterial growth, and carbon dioxide evolution was performed in three conditions: PT206 with PET, Control without PT206, and Control without PET. During incubation, the bacteria were able to grow, and the cumulative carbon dioxide increased. However, these changes were not significantly different from the control. The water contact angle of the treated plastic decreased from 67.12 ± 1.02° to 61.19 ± 3.31°. Furthermore, the infrared spectrum revealed a change in all PET peaks in the plastic incubated with bacteria and SEM showed abundant biofilm on the treated plastic surface, which was not observed in the control. These results indicate that the incubation of PT206 with PET for 1 month led to changes in the PET surface.

EXTRACTION AND CHARACTERIZATION OF PECTIN FROM PINEAPPLE PEELS (ANANAS CONOSUS) AND COCOA HUSK

Jitrayut Jitonnom, Panthip Tue-ngeun, Padarat Ninjiaranai, Waleepan Rakitikul — Tue, 19 Nov 2024 00:00:00 +0700

Pineapple peels and cocoa husks are typically discarded as agricultural waste from food processing in many areas of Chiang Rai. Here, we aim to extract and characterize the pectin from the pineapple waste and cocoa husk collected in the Chiang Rai area. Pectin was initially extracted using organic solvents (hydrochloric acid and citric acid), followed by ethanol precipitation. The pectin extracted was then evaluated for its dry matter yield, equivalent weight, and degree of esterification (%DE). The results showed that the pineapple residue contained 1.50-2.97% pectin, whereas the cocoa husk contained 6.20-15.86% pectin. The gram equivalent weight of cocoa husk was approximately 800-900, while pineapple waste was 1,300. The extracted pectin displayed low methoxy content, with a low level of DE (11-22%). Finally, the functional groups of pectin extracted were confirmed by Fourier transform infrared spectroscopy, showing the existence of the –C=O and C–O stretching peaks at 1600-1700 and 1100-1200 cm^-1, respectively. This preliminary study provides useful information for future studies on the gelling properties of the pectin from pineapple and cocoa husk waste.

TITANIA NANOTUBES FABRICATION BY ELECTROCHEMICAL ANODIZATION AND DYE DEGRADATION PROCESS

Arsha Anilkumar Suprabha, Donald Henry Raja — Tue, 22 Oct 2024 00:00:00 +0700

The potential of photocatalysis applications rapidly expands, offering energy-efficient solutions across various industries. Titanium dioxide nanotubes (TiO₂NTs/TNTs) are emerging as effective catalysts for water filtration techniques. Electrochemical anodization is the preferred method for producing suitable TNTs on a titanium plate. The key challenge lies in fabricating these desired TNTs efficiently in terms of time, cost, and energy. These effective nanotubes can achieve optimal photocatalytic dye degradation by modifying their optical and morphological properties. This paper explores the fabrication of NTs by manipulating different parameters and the successful application of Titania in dye degradation through appropriate doping.

A REVIEW ON TORSIONAL PROPERTIES OF COMPOSITES

Rajkumar Patil, Anand Reddy — Tue, 26 Nov 2024 00:00:00 +0700

Composite materials have gained significant attention in various engineering fields due to their unique mechanical properties and versatility. This review focuses on the torsional properties of composite materials, exploring the fundamental aspects that govern their behavior when subjected to torsional loads. Torsional properties, including shear modulus, fiber orientation, anisotropy, torsional strength, manufacturing considerations, and testing methodologies, are examined in detail. Understanding the torsional behavior of composites is crucial for optimizing their performance in applications ranging from aerospace to sports equipment. This review paper provides a concise overview of the key considerations and parameters involved in assessing the torsional properties of composite materials, offering a foundation for further research and application in this field.