Suranaree Journal of Science and Technology

STRUCTURAL, DIELECTRIC, AND ENERGY STORAGE PROPERTIES OF Ba2+ DOPED LEAD-FREE NaNbO3-BASED CERAMICS

2025-03-25T16:20:33+07:00

NaNbO₃-based antiferroelectric ceramics have recently attracted significant attention due to their potential in energy storage applications. This study explores the effect of barium (Ba²⁺) doping on the dielectric and energy storage properties of 0.88NaNbO₃-0.12Sr_0.7Bi_0.2TiO₃ (0.88Na_1-₂_xBa_xNbO₃-0.12Sr_0.7Bi_0.2TiO₃, where x = 0.0-0.025) ceramics synthesized via the solid-state reaction method. The XRD results indicated that all samples possessed an orthorhombic structure. The transition temperature from the antiferroelectric P phase to R phase (T_P-R) significantly increased from 141℃ at x = 0.0 to approximately 160°C for x ≥ 0.01. Additionally, the dielectric loss (tanδ) within the temperature range of 32°C to 130°C for the 100xBa ceramic exhibited a notable reduction, decreasing from 0.012 (x = 0.0) to 0.002 (x = 0.025). As the Ba²⁺ doping content increased, the remnant polarization significantly decreased, leading to a narrower P-E hysteresis loop with enhanced energy storage density and efficiency. Consequently, the x = 0.015 composition achieved a maximum recoverable energy storage density of 0.28 J/cm³ and an energy storage efficiency of 76% under an applied electric field of 125 kV/cm. These findings guide the development of NaNbO₃-based antiferroelectric materials with enhanced energy storage.

THE EFFECT OF BLANK THICKNESS, CURVATURE RADIUS, AND FRICTION COEFFICIENTS ON THE QUALITY OF PRODUCTS IN THE METAL FORMING PROCESS USING ABAQUS

2025-01-06T08:41:10+07:00

In recent years, mechanical techniques have been exponentially developing, among which metal forming is indispensable. The mechanical parts by this method often exhibit uneven thickness, directly affecting the durability of the product. This study investigates and analyzes the effect of material thickness, friction coefficient, and the fillet radius between the punch and die mechanism on the quality of the product using the metal forming method. The simulation process is conducted using Abaqus software, with the Taguchi method subsequently applied to evaluate the effect of the technological parameters. The results show that the material thickness and curvature radius have the greatest impact on the performance of the product.

TRANSPARENT BARIUM TITANATE GLASS CERAMIC NANOCOMPOSITES FOR OPTOELECTRONIC DEVICE APPLICATIONS

2025-03-17T17:51:33+07:00

The glass crystallization process was applied to create a nanocomposite material composed of crystallites within a glass-like matrix. The structural optical and dielectric properties of crystals embedded in a glassy matrix, the BaTiO₃-Na₂O-B₂O₃-SiO₂ system generated by the melt quenching process, were investigated in this study. The heat treatment procedure was used to convert the prepared glass to glass-ceramic samples at temperatures ranging from 700 to 800°C. After being quenched between stainless steel plates, the X-ray diffraction results reveal the presence of crystalline phase in a glassy matrix. Scanning electron micrography and transmission electron micrography were used to investigate the crystal morphology. The glass transition and crystallization temperatures were investigated by using the differential thermal analysis. The optical transmittance spectra in the wavelength range of 300-1000 nm were then recorded using UV-Vis spectrophotometer. A precise LCZ meter was used to measure the dielectric characteristics at various frequencies. It was demonstrated that crystallites form using a specific method, resulting in anisotropic glass ceramic. The shape and crystallinity of the produced samples influence their optical and dielectric properties.

VOLUMETRIC PROPERTIES OF STONE MASTIC ASPHALT MIXTURE INCORPORATED WITH NANO SILICA AND GLASS FIBER

2025-02-21T08:37:29+07:00

Stone Mastic Asphalt (SMA) has become integral to contemporary road construction due to its exceptional durability and performance. The stability of SMA, a key determinant of its resistance to deformation under diverse traffic and environmental conditions, underscores its effectiveness. Moreover, the flow characteristics of SMA play a pivotal role in its workability and compaction during construction. This study aims to evaluate the impact of nano silica-modified bitumen on rheological properties, encompassing viscosity, penetration, and softening point. Additionally, the research investigates the influence of glass fiber reinforcement on the mechanical properties of the asphalt mixture, explicitly focusing on volumetric properties and the Marshall stability test. In pursuit of these objectives, pure bitumen underwent modification with (1-5%) nano silica using a high-shear mechanical mixer, and (0, 0.2, 0.4, 0.6, 0.8, and 1%) glass fiber was incorporated into the asphalt mixture. The findings reveal that the asphalt mixture exhibits enhanced Marshall stability, stiffness, and flow values compared to conventional asphalt mixtures. Notably, the modified bitumen containing 4% nano silica and the hybrid asphalt mixture with a 0.4% glass fiber concentration demonstrate the most significant improvements in Marshall stability. The study establishes a positive correlation between the addition of nano silica to bitumen and glass fiber to the asphalt mixture, indicating a beneficial impact on the overall mechanical characteristics of the pavement.

AN ANALYSIS OF THE SEIDEL LAPLACIAN ENERGY OF A FUZZY INTUITIONISTIC SYSTEM

2025-01-27T09:27:05+07:00

This paper presents one of the latest research works in intuitionistic fuzzy graph theory. Along with questionable concepts conveyed in distinctive languages, intuitionistic fuzzy set theory offers a noteworthy and ground-breaking depiction of vulnerability estimation. The concept of energy is related to the spectrum of a graph. The energy of graphs plays a vital role in graph theory. In mathematics, the total sum of the absolute values of the eigenvalues of the graph’s adjacency matrix is referred to as the graph’s energy. In the framework of spectral graph theory, this quantity is extensively studied. When analyzing various repulsive and appealing circumstances, energy graphs are a great tool. Analogous energies based on the eigenvalues of various additional graph matrices have been examined recently. Graph energy possesses numerous mathematical characteristics which are investigated in this paper. One type of graph energy is Seidel Laplacian energy. The Seidel Laplacian energy (SLE) of a graph has already been extended to fuzzy graphs. In this manuscript, it is extended to an intuitionistic fuzzy graph. Energy, Laplacian energy, and SLE of an intuitionistic fuzzy graph are evaluated using some examples, and their lower and upper bounds are derived.

THE BEHAVIOR OF BISMUTH OXIDE ON TELLURITE BORATE OXIDE BASED GLASS SYSTEM FOR IONIZING RADIATION SHIELDING

2025-03-18T15:08:45+07:00

This research, the photons shielding parameters such as mass attenuation coefficients (m_m), effective atomic number (Z_eff) and Kerma relative to air (K_a) for Bi₂O₃ based TeO₂-B₂O₃-Bi₂O₃ glass system have been simulated by WinXCom software program at energies of 10^–3-10⁵ MeV. Also, buildup factors (BFs) have been estimated in wide energy ranging 15 keV-15 MeV for penetration depths (PD) until 40 mean free path (mfp). The results of the glass system in formula (70-x)TeO₂-30B₂O₃-xBi₂O₃ at x = 10, 20, 30, 40 and 50 mol% exhibited that Bi₂O₃ partial replacement of TeO₂ adjusts photons attenuation behaviors for get better. In addition, charged particles (proton: H⁺ and alpha particles: He²⁺) shielding parameters such as mass sopping power (MSP) and projected range (PR) were evaluated using SRIM software program at kinetic energy ranging 10 keV-10 MeV. The results found that the 20TeO₂-30B₂O₃-50Bi₂O₃ glass sample which had the highest Bi₂O₃ content showed the largest m_m, Z_eff and BFs values, while the MSP and the PR were the lowest values. These results indicated that glass sample with high Bi₂O₃ content is superb for photons attenuation while low Bi₂O₃ content is excellent for H⁺ and He²⁺ shielding glass. The results of this research can be useful in enhancing the optimization of ionizing radiation shielding materials.

A GRID SEARCH OPTIMIZED HYBRID MODEL FOR SOLAR IRRADIANCE FORECAST USING EMPIRICAL MODE DECOMPOSITION AND BIDIRECTIONAL GATED RECURRENT UNIT

2025-02-04T15:14:32+07:00

To ensure the reliable operation of the power grid, an accurate forecasting of solar irradiance (SI) is highly essential. Classical forecasting methods struggle to capture the fundamental nonlinearity of SI, resulting in low forecasting accuracy. A hybrid model based on deep learning (DL) technique called EMD-GS-BiGRU, which is the combination of empirical mode decomposition (EMD) with Bidirectional gated recurrent unit (BiGRU) predictor and grid search algorithm is proposed in this paper. The suggested EMD-GS-BiGRU model constructed and tested in two different Indian locations: Chennai and Jammu, for different popular models: artificial neural network (ANN), long short-term memory (LSTM), gated recurrent unit (GRU), and their EMD-based hybrid version i.e. EMD-GS-LSTM and EMD-GS-GRU. The evaluation of the performance of the proposed model is performed by statistical and graphical analysis of one hour ahead seasonal SI forecasts. According to the findings, the lower average root means square error (RMSE) of 64.39 W/m²-83.46 W/m²is obtained by proposed model compared to contrast models. The proposed model also obtained higher yearly R² value, 0.9366-0.955 compared to other models. Furthermore, the study found that the EMD with grid search optimized BiGRU enhanced the RMSE (39.23%-47.31%) and mean absolute percentage error (MAPE) (41.82%-52.31%) compared to other standalone contrast models.

RARE EARTH OXIDE DIELECTRICS FOR FLEXIBLE TRIBOELECTRIC NANOGENERATOR

2025-04-01T13:11:32+07:00

Rare earth oxides (REO) are well known in catalysts, glass-related industries, and permanent magnets manufacturing for almost 70%, according to the mature industry. This work proposes the new developments of REO as the emergence for mechanical energy harvesting (MEH) technology. The binary-system of REO or R₂O₃, including La₂O₃, Sm₂O₃ and Nd₂O₃, are used as dielectric materials to incorporate polydimethylsiloxane (PDMS) for fabricating flexible triboelectric nanogenerators (TENG), one of MEH devices. The change in REO’s amount was studied at 0.5, 2.5, 5, and 10 wt%. Upon applying mechanical force in vertical direction, the PDMS/R₂O₃ TENG can convert mechanical energy into electricity for the best value of ~66 V and ~93 µA with power density of about ~62 µW·cm^-2. The PDMS/La₂O₃ can be used to fully charge the 0.22 and 0.33 µF capacitor within 3 seconds and power up over 100 LEDs directly. Moreover, the influence of triboelectric polarity and dielectricity on the triboelectric output performance is scientifically discussed by following the percolation point with air breakdown limitation’s theory. The researcher believes that the knowledge of this work will be inexhaustible useful to develop a group of REO in broad applications of MEH electronics in future.

LOW POWER DESIGN OF SPI AND I2C PROTOCOL IN VERILOG HDL

2025-02-05T09:21:43+07:00

A method for sharing data between a slave and a master is the SPI (Serial Peripheral Interface). The result of this paper explores a high-speed SPI configuration that utilizes clock gating, drawing inspiration from Motorola’s manual and is implemented in Xilinx’s Virtex 5 FPGA using Verilog 2001. It covers design strategies for managing the SPI bus, including handling multiple slave devices. The document also explores an I2C (Inter-Integrated Circuit) single master with a bidirectional data line, supporting multiple masters and efficient communication between devices. The I2C master can transfer numerous bytes of data, controlled through a start signal and slave address. The design is in Verilog, simulated with Xilinx Vivado, and is parameterized for flexibility. The goal is to provide a deep understanding of SPI and I2C protocols, their applications, and implementation in FPGA devices, along with insights into their design and simulation process.

THE EFFECT OF Nb2O5 FOR GAMMA RAYS, FAST AND THERMAL NEUTRONS SHIELDING ON B2O3-TeO2 BASED GLASSES

2025-03-19T13:42:52+07:00

In this work, the glass system in formula (70-x)B₂O₃-30TeO₂-xNb₂O₅ at x = 0, 10, 20, 30, 40 and 50 mol% were determined gamma rays, fast and thermal neutrons shielding properties. The gamma-ray shielding properties have been explained for some parameters such as mass attenuation coefficients (m_m), effective atomic number (Z_eff), and half value layer (HVL). These parameters were evaluated by the WinXCom software program at energies of 10^-3-10⁵ MeV. While fast and thermal neutrons were calculated based on the macroscopic neutron capture cross-section. The results found that the addition of Nb₂O₅ by replacing B₂O₃ improved gamma ray shielding characteristics. This event also improved fast neutron shielding. Whereas, the thermal neutron found that the low Nb₂O₅ content was superb. These results reflected that the glass sample with high Nb₂O₅ content is excellent for gamma rays and fast neutron attenuation while low Nb₂O₅ content is excellent thermal neutron shielding glass. The results of this study are useful in enhancing the efficiency of materials for shielding gamma rays, fast and thermal neutrons.

MODEL PREDICTIVE CONTROL (MPC) AND PROPORTIONAL-INTEGRAL-DERIVATIVE (PID) CONTROLLERS FOR LOAD FREQUENCY CONTROL SCHEME

2025-01-30T08:44:53+07:00

This study aims to examine the use of Proportional Integral Derivative (PID) and Model Predictive Control (MPC) in Load Frequency Control (LFC). A balance between the generation and the load is necessary to ensure the consistency of the electrical supply. These days, MPC techniques are becoming popular due to their merits over conventional PID controllers. In this study, performance of the designed PID and MPC schemes has been tested and compared for two area interconnected power system. This system consists hydro unit in area-1 and three Thermal units in area-2. A step load perturbation scenario in both areas has been obtained to evaluate the effectiveness of the designed control strategies. The results show that both the designed control approaches performed successfully however, the MPC scheme outperform the PID scheme in terms of time domain specifications like reduced oscillation and smaller settling time. It can be concluded that MPC can be used as a secondary controller for LFC applications in future research.

EFFECT OF (AlNb)4+ B-SITES SUBSTITUTION ON THE PHASE STRUCTURE, MICROSTRUCTURE AND ELECTRICAL PROPERTIES OF Bi0.47Na0.47Ba0.06TiO3 CERAMICS

2025-04-02T15:52:46+07:00

Bi_0.47Na_0.47Ba_0.06Ti_1-x(Al_0.5Nb_0.5)_xO₃ (abbreviated as BNBT_1-xAN_x) lead-free ceramics (x=0-0.05) were synthesized by the solid-state combustion technique. The effect of (AlNb)⁴⁺ content on the phase structure, microstructure and electrical properties was investigated. A pure perovskite structure was obtained from all specimens. Rietveld refinement revealed coexisting rhombohedral and tetragonal phases in all samples and the tetragonal phase increased with increased AlNb content (x). The morphology of the BNBT_1-xAN_x ceramics displayed nearly round grains and anisotropic grain growth. Average grain size decreased from 1.8 to 0.7 µm when x increased from 0 to 0.05 and the grain size distribution became narrower. The density, maximum dielectric constant and remnant polarization rapidly decreased with increased x. The deterioration of the electrical properties induced by (AlNb)⁴⁺ substitution was due to shifting away from the morphotropic phase boundary (MPB), poor microstructure and low density.

DIFFUSE PHASE TRANSITION AND DIELECTRIC PROPERTIES OF MN4+-DOPED BA0.9CA0.1SN0.06TI0.94O3 PEROVSKITE CERAMICS

2025-03-12T16:13:19+07:00

In this work, a conventional solid-state reaction technique was used to successfully fabricate lead-free Ba_0.9Ca_0.1Sn_0.06Ti_0.94-xMn_xO₃ (BCSTM) perovskite ceramics, where x = 0.00, 0.03, 0.06, and 0.09. The effect of Mn⁴⁺ doping on structure, dielectric properties, and phase transition was investigated. The dielectric constant (ε) of Mn⁴⁺-doped BCST ceramics was enhanced by Mn⁴⁺ incorporation, as measured by LCR meter at room temperature. The dielectric constant (ε) of 4963 and the low dielectric loss (tanδ) of 0.0241 were obtained at the composition of x = 0.06 at room temperature, with a frequency of 1 kHz. The dielectric property investigation indicated that the degree of the diffuse phase transition behavior increased with Mn⁴⁺ substitution. The phase transition from tetragonal to cubic symmetry was significantly dependent on the amount of Mn⁴⁺ added. It also was found that the diffuseness of the phase transition behavior of BCST ceramics was enhanced, while the phase transition temperature (TC) of these ceramic samples decreased with an increase in the content of Mn⁴⁺. In addition, the diffuseness of the phase transition behavior was enhanced with an increase in the content of Mn⁴⁺. The replacement of Mn⁴⁺ at the Ti⁴⁺ site led to diffuseness and a rapid decrease in the phase transition temperature (T_C or T_m).

PREPARATION AND DIELECTRIC PROPERTIES OF PVA AND P(VDF-HFP) ALTERNATING MULTILAYER FIBERS FOR ENERGY STORAGE APPLICATIONS

2025-03-21T14:15:13+07:00

Dielectric polymer capacitors with high energy storage density are becoming increasingly important for the current advancements in electrical power applications. Energy storage performance in dielectric materials not only depends on the dielectric breakdown strength but also dielectric constant. This study focuses on the dielectric properties of polyvinyl alcohol (PVA) and poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) alternating multilayer fibers with different layers. Alternating multilayer structures layer by layer were prepared by using an electrospinning technique with suitable conditions, and the thickness of multilayer fibers was controlled by time. Alternating multilayer of P(VDF-HFP)/PVA structures can bring impressive the dielectric performance and energy storage efficiency. The morphology of obtained fibers was investigated by SEM. The dielectric properties and conductivity of multilayer fiber were investigated by using an LCR meter. The dielectric constant and conductivity of PVA and P(VDF-HFP) alternating multilayer fibers increase with the increasing number of layers. The dielectric constant of alternating multilayer fibers (8 layers) at a frequency of 20 Hz is observed to increase by 38.7% compared to PVA fibers. It appears that the integrated PVA and P(VDF-HFP) fibers, through an alternating multilayer structure, influence the interfacial polarization and the dominant charge carriers in each fiber layer. Additionally, the energy storage density of alternating multilayer fibers (8 layers) at 20MV/m is enhanced by 34.0% compared to PVA fibers.

PROPERTY IMPROVEMENT OF HEMP-ENHANCED INTERLOCKING BLOCKS WITH DURABILITY EVALUATION AND ENERGY EFFICIENCY

2025-01-13T13:02:55+07:00

This study focused on the property improvement and durability evaluation of hemp-enhanced interlocking blocks to meet the standards specified in TIS 58-2560. The blocks were produced using Type I Portland cement, soil, and hemp with a weight ratio of 1:2:0.4 and were formed using interlocking block-making machines. The properties were enhanced through the incorporation of Al₂(SO₄)₃, natural rubber latex, and polymers. Samples were air-cured for 28 days and subjected to 12 cycles of wetting and drying, after which they were tested for compressive strength, water absorption, and dry density. Thermal properties were also evaluated to calculate the OTTV. The results demonstrated that the incorporation of 15% Al₂(SO₄)₃ improved the compressive strength, with values of 5.41 MPa after air curing, which increased by 111.33% compared to the hemp concrete without improvement. After 12 wetting and drying cycles, compressive strength was 5.55 MPa, with both values meeting the TIS 58-2560 standards. Additionally, thermal conductivity was recorded at 0.16 w/m°C, with a specific heat capacity of 1.24 kJ/kg°C and a density of 1,260 kg/m³. The OTTV peaked at 19.97 w/m² when the walls faced southeast, which was lower than that of red bricks, concrete blocks, and lightweight concrete blocks. These findings indicated that hemp-enhanced interlocking blocks with 15% Al₂(SO₄)₃ not only met strength standards but also offered energy-efficient properties, making them suitable for sustainable construction. This material effectively reduced energy consumption from air conditioning due to its low OTTV values. As it utilized hemp, an agricultural waste product that would otherwise require disposal, it also contributed to waste reduction and minimized environmental impact.

A COMPARISON OF THE LUMINESCENCE AND SCINTILLATION PROPERTIES OF Lu2.5Y0.5Al5O12:Ce SINGLE CRYSTAL AND TRANSLUCENT CERAMIC

2025-03-17T16:36:46+07:00

This research studied the comparative luminescence and scintillation properties of Ce-doped Lu_2.5Y_0.5Al₅O₁₂ single crystal and translucent ceramic. The translucent ceramic and single crystal samples were fabricated by spark plasma sintering (SPS) furnace and the floating zone (FZ) furnace, respectively. The microstructure of both samples was investigated by scanning electron microscopy (SEM) technique. The transmittance of single crystal showed 77% in visible light range with the absorption at 350 nm (4f-5d₂) and 450 nm (4f-5d₁), while the translucent ceramic exhibited approximately 8% in visible light range with absorption is 350 nm (4f-5d₂) and 490 nm (4f-5d₁). The photoluminescence (PL) emission band was 518 nm (Ce³⁺: 5d-4f transition) for single crystal and 548 nm (Ce³⁺: 5d-4f transition) of translucent ceramic. The radioluminescence spectra presented a broad emission band 490-700 nm for both samples. At 662 keV γ-rays, the scintillation light yield value of single crystal and translucent ceramic was 6,700 and 4,900 photons/MeV, respectively, via comparison with Ce-doped Gd₂SiO₅ (GSO:Ce). The PL decay curves were fitted by single exponential function with a fast decay time constant of 51 ns for single crystal and 60 ns for translucent ceramic.

AN ADVANCED STRATEGY FOR OPTIMAL SITING AND SIZING OF DISTRIBUTED GENERATORS THROUGH GENETIC ALGORITHM AND D-STATCOM INTEGRATION FOR SUSTAINABLE POWER SYSTEM OPERATIONS

2025-02-07T16:23:19+07:00

This research article suggests a unique technique for the best placement and size of distributed generators (DGs) which may in the form of solar or wind in a power system network. The objective is to identify the optimum positions and sizes of the DGs that minimize the power losses in addition to fulfill increased load demand in the system. The proposed methodology combines two methods: the Genetic Algorithm (GA) and the Least Power Deprivation (LPL) method. The LPL method is used to determine the optimum positions of the DGs, while the GA is used to determine their optimum sizes. Potentially unstable voltage spots in a power system can be identified by computing the Voltage Stability Index (VSI) of each bus. Installing a Distribution Static Compensators (D-STATCOM) at these sites reduces voltage fluctuations, improving overall system stability and dependability, which is essential for preserving operational effectiveness and averting power network cascade failures. The methodology is validated through extensive simulations on the 30-bus IEEE power network using simulink. The study provides valuable insights into the best positioning and sizing of DGs and D-STATCOMs in power systems, which can help power system operators and planners in enhancing the overall system performance and reliability including reduction in carbon emissions and supplying clean energy. The proposed methodology is also compared with other intelligent techniques reported in literature to determine its versatility and applicability like harmony search algorithm, fire fly algorithm, coyote optimizers and particle swarm optimization; is generic and can be applied to other power systems as well for optimum location and sizing of DGs.

EFFECT OF RAPID THERMAL ANNEALING TREATMENT ON THE ELECTRICAL CONDUCTIVITY OF NANOCRYSTALLINE ZINC OXIDE DOPED WITH ALUMINUM

2025-04-01T11:05:51+07:00

Spherical nanocrystalline aluminum-doped zinc oxide (nc-AZO) has shown an improvement in conductivity and optical properties under rapid thermal annealing (RTA) treatment. The typical treatment at 500℃ for 1 h. on nc-AZO provides low electrical conductivity and low photocurrent, whereas RTA treatment performs better properties with above 85% optical transmittance and higher electrical conductivity. The diameter size of nano-spherical nc-AZO is around at 10-30 nm providing the energy band gap between 3.2 eV and 3.4 eV. Thus, the high electrical and optical qualities of such nc-AZO films can be required for an electron transport layer and transparent contact electrodes for semiconductor devices.