Suranaree Journal of Science and Technology

ASSESSING THE PERFORMANCE OF HEMP CONCRETE IN WET-DRY CONDITIONS AND THERMAL PROTECTION EFFICIENCY

2025-04-21T12:00:57+07:00

This article presents the results of tests conducted on the properties of hemp concrete, evaluating its compressive strength, performance under wet-dry conditions, and effectiveness in preventing external heat transfer. The research began with the production of hemp concrete improved with Al₂(SO₄)₃ and polymers. The property tests were conducted following TIS 109-2517 standards and compared with TIS 58-2560 standards, including an assessment of performance after undergoing 18 cycles of wet-dry conditions. The comparison of heat protection was made between hemp concrete and lightweight concrete by calculating the OTTV and measuring heat flux using a box-shaped building model. The test results of hemp concrete cured for 28 days indicated an initial compressive strength of 4.31 MPa, a dry density of 1,008 kg/m³, and a water absorption value of 329 kg/m³. After 18 cycles of wetting and drying, the compressive strength slightly decreased to 4.27 MPa, the dry density reduced to 934 kg/m³, and water absorption increased to 463 kg/m³. Importantly, the compressive strength after 18 cycles remained within the acceptable range according to TIS 58-2560 standards. In evaluating the effectiveness of external heat protection, the hemp concrete sample showed a thermal conductivity of 0.14 w/m°C and a specific heat capacity of 1.02 kJ/kg°C. The maximum OTTV was 30.07 w/m² when the wall faced southeast. The heat transfer test results through the walls of the box-shaped building model aligned with the OTTV findings, suggesting that hemp concrete transfers less heat than lightweight concrete.The findings suggested that hemp concrete, enhanced with Al₂(SO₄)₃ and polymers, met TIS 58-2560 standards for strength and durability while providing better thermal protection compared to lightweight concrete, making it an effective energy-saving building material.

EFFECTIVENESS OF CORROSION INHIBITORS AND GGBS IN ENHANCING DURABILITY OF REINFORCED CONCRETE STRUCTURES EXPOSED TO CHLORIDE-RICH ENVIRONMENTS

2025-05-20T09:36:25+07:00

Corrosion presents a severe threat to the durability of reinforced concrete (RC) structures, particularly those exposed to chloride-rich environments. This study evaluates the efficacy of corrosion inhibitors, including calcium nitrate, sodium nitrate, and diethanolamine, incorporated at 3% by weight of cement in preventing corrosion in RC. In addition, to enhance sustainability and strength, 40% of the cement was replaced with ground granulated blast furnace slag (GGBS). Corrosion resistance was assessed through electrochemical evaluations. Diethanolamine exhibited superior inhibitory performance in both electrochemical studies. The findings suggest that using GGBS and inhibitors, particularly diethanolamine, enhances the corrosion re-sistance and durability of RC structures.

DURABILITY ASSESSMENT OF RUBBERIZED CONCRETE WITH AND WITHOUT STEEL FIBRE REINFORCEMENT

2025-04-01T13:59:01+07:00

Waste tyres are non-degradable materials that do not decompose easily, posing a significant threat to the environment. To address this issue, waste tyres are incorporated in to the rubberized concrete as a replacement for coarse aggregate. This research investigates the durability of rubberized concrete with and without steel fibres. Using only waste rubber in concrete results in inadequate strength due to the weak bond between the cement matrix and rubber shreds. To improve this bond, a sand coating with resin is applied to the surface of the rubber shreds. Two groups of concrete specimens were prepared: one containing only rubber shreds and the other incorporating both rubber shreds and steel fibres. Rubber shreds were added at proportions of 2.5%, 5%, and 7.5%, while steel fibres were included at ratios of 0.5%, 1% and 1.5%. Concrete specimens, including cubes (100×100×100 mm) and cylinders (150×300 mm), were cast. Durability tests were carried out on these specimens. The results demonstrated that the rubberized concrete containing steel fibres showed significantly improvements in water absorption, acid resistance, rapid chloride penetration and Impact test compared to rubberized concrete without fibres.

URBAN TRANSPORT RESILIENCE AND SUSTAINABILITY IN SOUTH KOREA AMID DISRUPTIONS

2025-05-13T09:45:07+07:00

Urban transportation systems must be resilient to external shocks, such as climate change, public health crises, and evolving urban mobility demands. This study analyzes daily ridership patterns in South Korea (2018-2021), using the COVID-19 pandemic as a stress test to assess transit resilience. By examining statistical relationships between subway, bus, and bicycle usage, the study identifies strong interdependencies between subways (6.4 millions daily riders) and buses (4.56 millions), with a 98% correlation, while bicycles (36,793 daily riders) remain poorly integrated into the transit network. These findings highlight the need for multimodal connectivity, adaptive infrastructure investments, and transit electrification to strengthen urban mobility resilience against future disruptions. The study’s insights extend beyond South Korea, offering a data-driven framework for global cities to design sustainable, shock-resistant transportation networks that balance efficiency, resilience, and environmental imperatives in an era of increasing uncertainty.

DEVELOPMENT OF INTERLOCKING BLOCKS FOR CONSTRUCTION IN SALINE AREAS

2025-04-30T08:13:00+07:00

This research focuses on developing interlocking blocks for construction in saline environments, which present challenges due to the corrosive effects of salt on conventional building materials. The study aims to improve the durability and compressive strength of interlocking blocks by optimizing ratios of Type 1 and Type 5 portland cement, combined with laterite soil and water. Tests were conducted to evaluate the blocks’ performance, particularly their resistance to saline soil and compressive strength, across 7, 14, 21, and 28 days. The findings reveal that blocks with higher proportions of Type 5 cement exhibited enhanced resistance to salinity, while Type 1 cement contributed to greater compressive strength. The optimal mix (2.5:2.5 ratio of Type 1 and Type 5 cement) provided both high compressive strength and superior salinity resistance, making it suitable for construction in saline environments. The study emphasizes the potential of these improved interlocking blocks for sustainable use in regions with saline soil, extending the lifespan of structures built in such areas.

EFFECTS OF HOT FILTER MEDIA ON THE YIELD AND PROPERTIES OF FUEL OBTAINED FROM THE PYROLYSIS OF RUBBER DUNG

2025-03-21T08:39:04+07:00

This research aimed to study the effect of hot filter media on the yield and properties of fuel obtained from the pyrolysis of rubber dung in a fixed bed reactor under a reaction temperature of 300°C for 2 hours. The hot filter media used in this study consisted of dolomite, charcoal, charcoal pellets, rice husks, and rice husk pellets. The hot filter operates at a reaction temperature of 100°C. The results indicated that pyrolysis of rubber dung without filter media yielded a maximum fuel content of 70 wt%. When the filter media was placed in the hot filter, the yield of fuel significantly reduced. Dolomite resulted in a minimum reduction in fuel yield of 49 wt%. However, the fuel obtained using different types of filter media exhibited improved properties. Dolomite increased the heating value of the fuel to a maximum of 42.4 MJ/kg and reduced viscosity by up to two times. Therefore, it can be concluded that using hot filter media in pyrolysis reduces the yield of fuel but improves its properties, and is suitable for producing fuel oil from rubber waste through pyrolysis. Further research should be conducted to expand the application of this process to real-world community use.

FAULT LOCATION OPTIMISATION USING GOLD RUSH OPTIMISER IN GEOTHERMAL HYBRID POWER PLANT

2025-03-26T16:28:49+07:00

With fossil fuel still happening to be the major source of input to power generation globally, the environmental complications caused by it are becoming more conspicuous. This is particularly reflected in the huge amount of CO₂ emissions taking place globally due to the high percentage use of fossil fuel. In this context, renewable energy combined with conventional energy in the form of hybrid energy offers a sustainable and environment friendly solution. But, in cases where the renewable input is from the core of the earth in the form of Geothermal energy, proper otimisation of it combined with conventional source becomes an important aspect. The presented paper focusses on optimisation technique using a novel algorithm “Gold Rush Optimiser” (GRO). The simulation of the hybrid power system has been done in MATLAB simulink. The study considers a maximum transmission line length of 300 km and a minimum absolute percentage error of 0.0001 for the stated fault location. The results obtained with the proposed algorithm are highly accurate compared to other optimisation techniques. It efficiently determines locations with remarkable precision and speed, owing to its faster convergence rate. GRO’s potential in fault location optimisation keeps expanding as power grids get smarter and more decentralized.

A STUDY ON THE INFLUENCE OF NANOFILLERS ON THE VIBRATIONAL CHARACTERISTICS OF FIBER METAL LAMINATES

2025-03-10T14:57:18+07:00

In the last several years, there has been a discernible increase in research devoted to developing innovative and complex composite materials. Because of their superior performance, especially in the aircraft industry, Fibre Metal Laminates (FML) and hybrid structures made of glass, aramid fibre, carbon, or aluminium are the most commonly used of these new technological commodities. Thus, free vibration analysis is the first step in the design of these structures. The current work examines the vibration behavior of a fiber-metal-laminate (FML) composite beam using numerical and experimental methods, a novel material for aircraft. This research series evaluated the bending natural vibration frequencies of the multi-walled carbon nanotube FML composite cantilevered beam. The Bruel and Kjaer (B and K) Fast Fourier Transform (FFT) analyzer with a PULSE platform was used in this study to find the intrinsic vibration frequencies of glass FML beams. Two parameters that investigated the dynamic behavior of the FML composite beam were the amount of MWCNT filler material and the beam's length. There was a reasonable agreement between the experimental and numerical results and the natural frequencies. The amount of MWCNT filler added to the glass fiber epoxy enhances the natural frequency of the FML composite cantilevered beam, according to both experimental and computational calculations. Furthermore, it was discovered that the vibration's inherent bending frequency decreases with the beam length.

ENHANCING STRUCTURAL PERFORMANCE AND SUSTAINABILITY WITH CO₂ ABSORBING CONCRETE USING ZEOLITE AND GGBS

2025-05-13T14:41:15+07:00

Despite being one of the most popular building materials, the manufacture of concrete greatly increases CO₂ emissions. Zeolite and ground granulated blast furnace slag are used in this study to partially replace ordinary Portland cement in order to explore the possibility of CO₂-absorbing concrete. While GGBS promotes durability and mechanical qualities, zeolite’s microporous structure aids CO₂ sequestration. The impacts of these materials on carbonation depth, compressive strength, split tensile strength, and CO₂ absorption capacity are the main topics of this study. Mix designs for M30 grade concrete were created by substituting 10%, 20%, and 30% zeolite for OPC in addition to a fixed 30% GGBS. Compressive strength, split tensile strength, carbonation depth, and CO₂ absorption by weight were all evaluated for specimens of hardened concrete. According to the data, compared to normal concrete, a 30% Zeolite and 30% GGBS replacement improves split tensile strength by 7.75% and compressive strength by 11.54%. Furthermore, the depth of carbonation rose fivefold, and the absorption of CO₂ improved considerably. These findings demonstrate how Zeolite and GGBS can improve concrete’s performance while lessening its negative effects on the environment, making it a workable option for environmentally friendly building.

SEISMIC STRENGTHENING OF RIGID FRAME BY FERROCEMENT WITH EXPANDED METAL MESH AND EXTERNAL FLEXURAL REINFORCEMENT

2025-05-08T08:17:20+07:00

Typical low rise commercial buildings are often damaged due to the soft-story effect under earthquake loading. Failure modes include flexural and shear failure at the ends of columns. To improve the flexural strength of the rigid frame, an analytical model to predict the lateral resistance of the strengthened frame was proposed. The study focused on the strengthening of the RC column with expanded metal and external longitudinal reinforcement and the strengthening of the beam-column joint. The specimens were subjected to the axial vertical load and the lateral load. A single-story, single-bay frame was selected as the prototype. Two sets of specimens were prepared to the full scale. The experimental program consisted of two types of test specimens: (1) a bare reinforced concrete (BF) frame as the control and (2) a reinforced concrete frame strengthened with ferrocement (BFS). The experimental results showed that the BFS specimen exhibited significant improvements in the lateral load capacity, stiffness, and ductility with 119%, 110%, 47%, respectively greater than the original frame. The structural performance enhancements are attributed to the respective contributions of ferrocement layer strengthening (22%), external reinforcement (45%), and the original column’s inherent moment resistance (33%), as derived from the total moment capacity. The lateral resistance resulting from the laboratory test and the analytical model showed a difference of 2.48%, indicating an acceptable prediction. The test results were also compared with the results of numerical analysis using the nonlinear structural analysis by the RUAUMOKO software. The results were found to be in good agreement.

A TRANSFORMER LESS SELF-BALANCING HIGH-GAIN 7-LEVEL INVERTER WITH MINIMUM COMPONENT COUNT AND LOWER VOLTAGE STRESSES FOR SOLAR PV APPLICATIONS

2025-03-20T08:51:59+07:00

This article presents a revolutionary 7-level, nine-times voltage boosting property converter. The main disadvantage of traditional Multilevel Inverter (MLI) is that, in order to use renewable energy sources, a high-voltage DC-DC chopper must be tolerant of raise input voltage. The suggested converter makes use of ten switches, two inductors, four diodes, three switching capacitors, and just one DC supply. The capacitor’s voltage equalizes itself automatically. Less components are needed and a capacitor is used instead of a DC source to create the switched capacitor MLI. To produce the output voltage waveforms with seven levels, the switching Inductor/capacitor must be appropriately charged and discharged. Without requiring a voltage regulating circuit with a closed loop, the suggested inverter can self-balance the capacitor’s voltage. Because of the continuous series-parallel discharge and charging over a full cycle, three capacitors receive equal charges from the input source and the inductors. Compared to the majority of recently produced topologies, the suggested 7-level Switched Capacitor (SC) inverter involves a reduced number of switches, driver diodes, capacitors, also semiconductor switches. Additionally, four pairs of switches run simultaneously using the same control signal, simplifying the control system, and eight of the ten the fundamental frequency is used by switches to function. An elementary frequency switching system is employed to regulate the inverter’s output. On the PSIM/MATLAB platform, the suggested structure’s voltage-boosting and self-balancing capabilities are verified.

NUMERICAL STUDY ON ANALYSIS AND DESIGN OF OFFICE BUILDING USING ETABS (G+7)

2025-03-07T13:05:18+07:00

This study focuses on the analysis and design of a G+7 office building in Chennai using the structural software ETABS. The building with a typical floor height of 3.9 m and 3.6 m at the stilt level. It has a length of 56 m and width of 25 m. As the structure is planned to be an office building for a tech park, majority of the floor is earmarked for computer systems, and cubicles, and thus will be a typical office floor, with pantry areas and restrooms located in certain marked areas, which will have sunken floors. In addition to the above-mentioned functions, there will be an electrical room with higher equipment loads, and staircase regions and lift lobby areas with higher live loads. In this project, ETABS software were used for modelling, analyse and design the office building for optimization of structural members, load distribution, efficiency of material selection and compliance with IS codes. Key findings from ETABS analysis includes storey drift, base shear, bending moment, shear force and deflection. The end use of this structure is for a IT park, so the required design life of the building is 50 years. To ensure that the building properly serves its function for the whole design life duration, necessary design considerations should be taken care of as per IS code.

NOVEL ENRICHED TEACHING - LEARNING INSPIRED OPTIMISATION AND QUANTUM OPPONENT PROCESS THEORY-BASED ALGORITHM FOR POWER LOSS DIMINUTION

2025-05-20T09:16:55+07:00

The enriched teaching-learning-inspired optimization algorithm (ETLO) and quantum opponent process theory-based (QOPT) algorithm are applied to solve the problem of reducing power loss. In this procedure, each learner in the population acts as a searcher and serves as a potential solution. During the course phases and statistics delivery, learners are trained to improve their skills in order to provide better solutions. The teacher will explore various methods to solve the problem as soon as possible. The environment of the human mind is ambiguous. In the exploitation period, learners of the procedure populations examine locally to discover improved solutions. The QOPT algorithm is based on how individuals observe changes in color and sensation over time. The opponent process theory explains how an individual experiences different color images in the time period following their exposure to the original image's color. The algorithm observes an individual's color over a specific time period as the original image appears and disappears. In the retina of the eye, the photochemical effect will be there for a certain period. The size of the object signifies the present rate of the candidate solution, and the distance of the object characterizes the extent from the finest solution. Enriched teaching - learning inspired optimization algorithm (ETLO) and Quantum Opponent process theory based (QOPT) algorithm validated in 7 benchmark functions and IEEE 118, 300 bus systems.

SLENDERNESS EFFECTS IN SFRC LONG BEAMS

2025-02-24T08:52:14+07:00

This study presents the findings from nine laboratory tests on rectangular long beams made of Reinforced Concrete (RC) and Steel Fiber Reinforced Concrete (SFRC). The experimental investigation shows that the long beams with SFRC show different behaviour in terms of load-deflection curve as compared to the RC long/slender beams. This study examines hooked-end steel fibers with two different aspect ratios i.e. 63.63 and 77.78. Three different grades of concrete (M25, M40 and M55) are considered to study as to how the variation in grade of concrete impacts the slenderness of the steel fibre RC long beams. The experimental study however shows that the deflection control of steel fibres with aspect ratio 63.63 is better than the steel fibres with aspect ratio 77.78. Also, it has been observed that the beams with grade of concrete M55 has a lower load carrying capacity as compared to other two grades as it fails due to instability (bending/twisting) at lower values of load. Finite Element (FE) analysis using ATENA confirms the findings from laboratory tests.

PERFORMANCE ENHANCEMENT OF BULK-DRIVEN QFG MOSFET LOW VOLTAGE CASCODE CURRENT MIRROR

2025-04-08T13:38:58+07:00

Bulk-driven (BD) and floating gate (FG) MOSFET are commonly used in applications where power consumption and voltage levels are relatively low due to their simplicity and efficiency. However, some drawbacks, such as reduced linearity and stability in the BD technique and reduction of transconductance in FG techniques, can be addressed by amalgamating both FG and BD techniques. This paper evaluates the performance of a bulk-driven quasi-floating gate (BDQFG) cascode current mirror circuit in comparison to a quasi-floating gate (QFG) and bulk-driven quasi-floating gate (BDQFG) current mirrors. The findings show that the BDQFG cascode current mirror offers an output resistance of 2.78 MΩ, input resistance of 3.71 kΩ with a bandwidth of 664.5 MHz and a current transfer ratio of 0.99. The bandwidth is further improved to 1.4 GHz and 1.93 GHz in subsequent modifications. The workability of the proposed circuits has been demonstrated using a ± 0.5 V power supply in a 130 nm CMOS technology. The design has been verified through simulation using PSpice

PHYSICOCHEMICAL, THERMAL AND PASTING PROPERTIES OF FLOURS FROM SELECTED NEW YAM CULTIVARS

2025-05-06T09:49:36+07:00

We investigated the physicochemical, thermal, and pasting characteristics of selected new yam cultivars - REP1BED8, TDR1100585, MECC9RU59, REP1BED4, TDR00396, TDR1100492, TDR0500491, REP1BED19, TDR0900082 and TDR0900002, at Ebonyi State University, Abakaliki. Our results showed significant variations in these cultivars' physicochemical, thermal, and pasting properties. The bulk densities of new yam cultivars varied between 680.45 to 780.34 kg/m³, actual density 1125.24 to 1225.35 kg/m³, wettability 1.14 to 3.24 seconds, water absorption capacity 198 to 375%, dispersibility 54.70 to 63.80%, oil absorption capacity 85.00 to 227.50 g/ml. The MECC9RU59 flour sample had a better swelling index of 98.50 to 215.00v/v. The results showed significant (P≤0.05) variations in the flour samples' thermal properties. The TDR0900002 new yam cultivar exhibited improved thermal conductivity 0.04 to 0.07 w/m²℃), specific heat capacity 1.18 to 1.63 KJ/Kg℃), thermal diffusivity 6.45 to 7.36 w/m²℃ compared with the other new yam cultivars. The TDR00396 flour sample had the highest peak viscosity, 249.11 N/m², highest trough viscosity, 218.20 N/m², highest final viscosity, 368.37 N/m², and lower breakdown viscosity, 30.89 N/m². The REP1BED4 flour sample had the highest pasting temperature, 93.89℃, and a higher paste time, 6.86 min, to form a viscous paste than other flour samples.

3-Ø, TWO-STAGE, GRID-INTERFACED SOLAR PV ENERGY CONVERSION SYSTEM WITH ADAPTIVE CONTROL BASED ON APPROXIMATE MULTIPLIERS

2025-03-31T09:07:38+07:00

In this work, a unique adaptive algorithm is successfully designed, controlled, and verified. For the grid voltage source converter (VSC) system, the suggested approximate multiplier least mean square (AM-LMS) management method effectively mitigates power disturbances without compromising power quality (PQ). Additionally, the VSC control method adds multipliers to the finite impulse response (FIR) filter and updates the coefficients of the circuitry to reduce the complexity of the LMS. Since it is more economical and reliable than other grid sides, the AC side is used. On the DC side, a bidirectional DC-DC converter and a photovoltaic (PV) array form the insular micro grid for which the VSC management is intended. On the DC side, a bidirectional DC-DC converter and a photovoltaic (PV) array form the insular micro grid for which the VSC management is intended the efficacy and validation of the suggested controller are guaranteed by the experiment findings. These results are considered satisfactory, with enhanced dynamic and steady state functionality and overall harmonic distortion of grid currents that meets the IEEE-519 standard resolution.