Journal of Engineering and Technological Sciences

Classical Mechanics Theory and Schrödinger's Equation: A Derivation of Relations

Jiancao Li, Yanchun Yu — Tue, 23 Sep 2025 00:00:00 +0700

This study examines integrating the Schrödinger equation with classical mechanics using a virtual axis-to-dimensional expansion. One-dimensional material fluctuations are viewed in a two-dimensional plane, explaining the random nature of these fluctuations and their spatial and temporal trajectories. A quantum-consistent force field is proposed, with its strength determined by the Planck constant and inversely proportional to the distance from the stationary point. Newton's second law is applied to establish a second-order linear differential equation for material fluctuations, from which the standard one-dimensional Schrödinger equation is derived, showing their equivalence. The study extends the three-dimensional Schrödinger equation to include external forces and explains quantum phenomena like energy levels and transitions through particle trajectory changes. This approach connects classical mechanics and quantum mechanics, offering a concise and intuitive formulation with clear physical significance.

Low Machining Parameters Produce High Cutting Performance when Machining AISI 1045 at Dry Cutting Conditions Using a CNC Lathe Machine

Tue, 23 Sep 2025 00:00:00 +0700

AISI 1045 medium-carbon steel is widely used for machining because of its excellent machinability. It balances strength and workability in various manufacturing applications, including machinery parts, gears, mold pins, automotive parts, crankshafts, bolts, and studs. The most significant disadvantage of AISI 1045 machining is that if the cutting parameters are not managed appropriately, it can affect the efficiency of the machining process, which involves tool life and product surface finish at dry cutting conditions. This study aims to determine suitable cutting parameters for AISI 1045, identify the optimum minimum tool wear (VB), and assess surface roughness (Ra). This study used various machining parameters at a cutting speed (Vc) of 35–53 m/min, feed rate (fr) of 0.15, and 0.5 mm/rev at a 1 mm constant depth of cut (DOC). The results showed that a Vc of 35 m/min and a fr of 0.15 mm/rev obtained the lowest average VB of 0.07 mm and Ra of 3.8 µm. This study found that low machining parameters produce high dry-cutting performance. This study provides guidelines for machinists to use appropriate cutting parameters when machining AISI 1045 under dry-cutting conditions at short machining times. In addition, it promotes sustainable machining and prevents air pollution from using coolants (chemical reactions).

Comparative Analysis of DTC-controlled TSTPI and FSTPI Inverters for Low-power Photovoltaic Applications

Nouira Imen, Bassem El Badsi — Tue, 23 Sep 2025 00:00:00 +0700

The increasing global shift towards renewable energy (RE) has amplified the need for efficient and cost-effective DC/AC converters in photovoltaic (PV) systems. This paper focuses on evaluating the performance of reduced structure inverters, specifically the Three Switch Three Phase Inverter (TSTPI) and the Four Switch Three Phase Inverter (FSTPI), both operating under Direct Torque Control (DTC), for low-power PV applications. A novel DTC strategy has been developed and applied to the TSTPI to improve control precision and overall performance. Through extensive simulations in Matlab/Simulink, complemented by experimental validation on a dSPACE1104 platform, we assess and compare the operational efficiency, harmonic distortions, and electromagnetic torque oscillations of both inverter structures.The findings reveal that, while both the TSTPI and FSTPI demonstrate satisfactory results, notable differences arise in terms of efficiency and harmonic distortion levels. These results highlight the suitability of reduced structure inverters for low-power PV applications, offering an attractive balance between cost and performance.This study provides valuable insights that can guide future developments in the design and real-time implementation of inverter systems tailored for RE applications.

Facile and Environmentally Friendly Synthesis of Low-defect Few-Layers Graphene (FLG) Using Combined Shear Exfoliation Methods

Tue, 23 Sep 2025 00:00:00 +0700

This study presents an environmentally friendly and scalable method for synthesizing high-quality few-layer graphene (FLG) through a combination of turbulence-assisted shear exfoliation (TASE) and high shear exfoliation (HSE) techniques. By systematically varying the high-shear mixer (HSM) speed (3000–5000 rpm) and processing time (1–3 hours), we precisely controlled key material attributes, including the number of graphene layers, crystallinity, lateral size, and defect density. Optimal conditions (5000 rpm, 3 hours) resulted in FLG with ~2–3 layers, confirmed by a symmetric 2D peak with a full-width at half-maximum (FWHM) of ~35 cm⁻¹ and a high I_2D/I_G ratio (~0.6), indicating excellent structural integrity. The I_D/I_G ratio (~0.1) further verified the presence of minimal defects, predominantly edge vacancies rather than oxidative disruptions. Raman imaging revealed a dominance of zigzag edge chirality, while TEM and PSA analyses demonstrated control over lateral size (~396.5 nm) and particle uniformity. The application of household dishwashing liquid as a green surfactant innovatively enabled selective and pure exfoliation. This work highlights how precise modulation of shear parameters can directly influence graphene quality, paving the way for sustainable large-scale production of low-defect FLG.

Strategic Location of Fluid Viscous Dampers in High-rise Reinforced Concrete Buildings for Seismic Resilience: A Comparative Analysis

Tue, 23 Sep 2025 00:00:00 +0700

High-rise reinforced concrete (RC) buildings are highly vulnerable to seismic forces due to their ‎inherent structural limitations, necessitating effective energy dissipation mechanisms. Conventional ‎damping strategies often fail to adequately control excessive vibrations, leading to potential ‎structural damage. Fluid Viscous Dampers (FVDs) offer a novel approach by significantly ‎improving energy dissipation and reducing seismic responses. However, the optimal configuration, ‎placement, and quantity of FVDs in high-rise buildings remain insufficiently explored, ‎necessitating this study. This research introduces a novel damper placement framework by ‎investigating the strategic positioning of FVDs in a 25-storey RC benchmark building, evaluating ‎‎80 damper configurations using non-linear time history analysis in ETABS. The study compares ‎Strategic Location Formats (SLFs) against Arbitrary Location Formats (ALFs) and Uniformly ‎Distributed Frames (UDFs) to determine the most effective and economical damper placement ‎strategy. Findings reveal that SLFs achieve superior seismic performance while using significantly ‎fewer dampers, demonstrating an innovative and cost-effective approach to structural damping. ‎SLFs achieve up to 45% reduction in displacement, 56% reduction in inter-storey drift, and 54% ‎reduction in base shear, using only 36 dampers, compared to 96 in ALFs and 192 in UDFs. ‎Additionally, SLFs are highly cost-efficient, requiring only 9% of total construction costs, ‎compared to 24% for ALFs and 49% for UDFs. This study establishes a novel, performance-based ‎damper placement framework, offering a scientifically validated methodology for optimizing ‎seismic resilience while maintaining economic feasibility. These findings make SLFs a ‎transformative solution for high-rise RC buildings in earthquake-prone regions.

Optimation PAN/TiO2 Nanofiber Membrane as Separator for Symmetric Supercapacitor

Tue, 23 Sep 2025 00:00:00 +0700

Supercapacitor is one of the energy storage systems known for their high-power density, long cycle life, and good cycling stability. To improve supercapacitor performance, we used a polymer PAN composite titanium dioxide (TiO₂) as the separator material. Nanofiber separator membranes of PAN/TiO₂ with various masses (0, 5, 10, 15, and 20 wt%) were successfully synthesized using the electrospinning technique. The addition of TiO₂for modified fiber, due to its high absorption rate for energy storage, increased electrolyte uptake and optimized supercapacitor performance. The morphology, functional groups, crystallinity, and thermal stability of the membranes were identified using scanning electron microscope (SEM), Fourier transform infra-red (FTIR), x-ray diffraction (XRD), and thermogravimetric analysis (TGA), respectively. It was found that the membrane with 15 wt% TiO₂exhibited a fiber diameter of 224.73 nm, pore size of 138.98 nm, the highest porosity of 66.50%, electrolyte uptake of 240%, and thermal stability up to 282°C, with a remaining mass of 3.94% after being tested at 1000°C. The electrochemical performance of the supercapacitors was measured using galvanostatic charge-discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The membrane containing 15 wt% TiO₂demonstrated optimum ionic conductivity of 4.4 x 10^-4 S/cm, gravimetric capacitance of 57.770 F. g^-1, and capacitance retention of 94.22% after 1000 test cycles.

Advanced Geotechnical Solutions for Soft Soils: FEM Analysis and Hybrid Reinforcement in the Semarang-Demak Toll Road Project

Tue, 23 Sep 2025 00:00:00 +0700

This paper presents an analysis of the data collected from the full-scale trial embankment implemented in the Semarang-Demak Toll Road project, part of a national strategic project in Central Java, Indonesia. The project integrates a sea dike with a road embankment. The main challenge of the project lies in constructing the embankment on soft soil layers up to 40 meters thick. The road embankment is designed to reach a height of 6 meters above Mean Sea Level (MSL) or 8 meters above the average seabed level. In the absence of ground improvement techniques—such as bamboo mattress, prefabricated vertical drains (PVD), or high-strength geotextiles—very soft soil with an undrained shear strength of approximately 6.5 kPa can support only a critical embankment height of about 3 meters. A hybrid reinforcement that combines bamboo mattresses, high-strength woven geotextile, PVD and staged embankment construction is selected to solve the shear strength and settlement problem. Mattress acts as platform and designed to deform as much as the soft-soil to spread initial embankment load uniformly and increase bearing capacity, PVD accelerates consolidation, and high-strength woven geotextile provides tension capacity. To achieve a load ratio of 1.3 in accordance with SNI 8460-2017, a 13.5-meter soil preloading needs to be constructed. Several monitoring systems were installed to monitor the behavior of the entire embankment system. Complementary investigations, including CPT, CPTu, and Deep Boring, were conducted. Finite element analysis (FEA) was then performed, revealing improved performance, achieving safety factors of 1.25 during construction and 1.55 long-term.

Integrated CFD and Aspen Plus Simulation for Optimizing Biomass Combustion: A Study on Sugarcane Bagasse

Maulana Gilar Nugraha, Eblin Alle Azarya, Muslikhin Hidayat, Harwin Saptoadi — Tue, 30 Sep 2025 00:00:00 +0700

This study presents an integrated simulation approach to optimize biomass combustion using sugarcane bagasse as a renewable feedstock. Computational fluid dynamics (CFD) was employed to model combustion hydrodynamics, while Aspen Plus was used to simulate pyrolysis product distribution based on Gibbs free energy minimization. The simulation involved key parameters such as air-fuel ratio, excess air level (100% and 200%), and combustion temperature profiles, which were validated against experimental data from a lab-scale grate-fired furnace. The pyrolysis results revealed that increasing the temperature from 400°C to 600°C significantly enhanced CO and H₂ concentrations, thereby improving syngas reactivity. CFD analysis showed that, at 100% excess air, CO₂ concentration reached 9.15% with an average freeboard temperature of 405.2°C, while at 200% excess air, the CO₂ dropped to 6.46% and the temperature decreased to 397.9°C, indicating reduced combustion efficiency. These results underscore the importance of optimizing air supply to enhance combustion performance and minimize unburnt volatiles. The findings confirm that integrating CFD and Aspen Plus simulations provides a reliable framework for improving the efficiency and environmental performance of biomass combustion systems.

Enhancing Random Forest Model Accuracy using GridSearchCV Optimization for Predicting Multi-Cylinder Engine Performance with Hydrogen-Enriched Natural Gas Blends

Tue, 07 Oct 2025 00:00:00 +0700

Diesel generators (gensets) are essential in India for industries, construction, agriculture, and as backup power for hospitals and data centres. Common fuels include diesel, petrol, natural gas, and, increasingly, solar energy, with hybrid systems gaining popularity for improved efficiency and reduced emissions. Diesel gensets remain reliable and cost-effective, especially in remote areas, but growing environmental concerns are driving adoption of cleaner alternatives like compressed natural gas (CNG), bio-CNG, and dual-fuel systems. HCNG (hydrogen-enriched compressed natural gas) gensets are more efficient and environmentally friendly, though they require greater initial investment. Adding hydrogen enhances combustion and reduces emissions. In this study, various HCNG blends were tested on a multi-cylinder, single-speed gas engine. Experimental evaluation of combustion and performance characteristics is typically time and resource-intensive, so Machine Learning (ML) was applied to streamline the process, thereby minimizing the number of required experiments. The engine performance is assessed using the engine dynamometer, whereas the combustion characteristics are obtained from the High-Speed Data Acquisition (HSDA) system. A Random Forest (RF) regression model was developed to predict performance and combustion characteristics for higher HCNG blends from lower-blend data, with hyperparameter optimization used to improve accuracy and minimize overfitting. Predicted values were validated against experimental results, showing strong correlations. Key parameters like Brake-Specific Fuel Consumption (BSFC), Brake Mean Effective Pressure (BMEP), Exhaust Temperature, Maximum In-Cylinder Combustion Pressure (Pmax), Indicated Mean Effective Pressure (IMEP) and Combustion Duration were predicted, with evaluations showing strong correlations between predicted values and actual results.

Experimental Research on Sustained Concrete with the Partially Substitutions of GGBS, Fly ash and Silica Fume as a Cementitious Material

Rajasekhar Cheruvu, B Kameswara Rao, M Achyutha Kumar Reddy — Wed, 08 Oct 2025 00:00:00 +0700

The aim of this study is to figure whether adding more cementitious elements like fly ash, ground granulated blast furnace slag (GGBS), and silica fume impacts the strength and durability of concrete. Concrete samples were put together with water-to-binder (w/b) ratios of 0.3, 0.4, and 0.5 after 28, 56, and 90 days of curing. After that, these ratios were tested before being employed. After 90 days, when 60% of the cement was replaced with fly ash at a water-to-binder (w/b) ratio of 0.3, the compressive strength reached 55.56 MPa. This is in contrast to the compressive strength of 32.89 MPa at 28 days. A 20% GGBS replacement also made the strength go up from 47.11 MPa after 28 days to 60.44 MPa after 90 days at the end of the trial. Adding 4% silica fume to each batch always made the strength grow stronger. The water sorptivity tests that were conducted to determine the durability performance showed that there was a substantial increase. The mixture with 20% GGBS and 4% silica fume, which had a water-to-binder (w/b) ratio of 0.4, had the lowest sorptivity value, which was 0.015 mm/min⁰·⁵. The study shows that alternative materials lower water permeability, structural integrity, and carbon emissions, promoting sustainable development. However, it knows that the building industry must source carefully and organize logistically to protect the environment.