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Volume 13, Issue 4, 2025

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Convection heat transfer enhancement techniques play a vital role in many industrial thermal processing applications, including food thermal processing, and the pharmaceutical, and chemical manufacturing industries. These techniques contribute to reducing the size and cost of heat exchangers, conserving energy, improving product quality, and enhancing both energy efficiency and thermal performance. Among passive solutions, corrugated wall tubes are widely adopted in heat exchangers for such applications. This study applies the inverse heat conduction problem (IHCP) method combined with infrared thermography data to estimate the local temperature and convective heat transfer coefficient distributions for forced convection in a transversally corrugated wall tube with high viscosity fluid flow under laminar conditions. The IHCP is solved within the corrugated wall domain using measured external wall temperatures as input. Thermal performance was evaluated over a Reynolds number range of 290–1200. The findings showed that at Re $<$ 350, irregular local temperature and convective heat transfer distributions led to reduced thermal efficiency, unreliable sterilization, and increased microbial risk, whereas for 650 $<$ Re $<$ 1200, thermal efficiency improved significantly. These findings support the development of more efficient heat exchanger designs, offering significant benefits to industries requiring precise thermal management.

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Perovskite solar cells (PSCs) continue to advance toward higher efficiencies, yet the geometrical design of functional layers remains a critical bottleneck for device optimization and manufacturability. This work establishes a hybrid physics-data framework that integrates three-dimensional finite-element modeling with machine-learningbased surrogate prediction to accelerate PSC thickness optimization. A full 3D COMSOL Multiphysics model was developed to resolve charge-transport behavior, spatial electric fields, and recombination profiles within TiO2/MAPbI3/Spiro-OMeTAD architectures. Systematic variations in electron transport layer (ETL), perovskite absorber, and hole transport layer (HTL) thicknesses reveal that device power conversion efficiency (PCE) is governed by a trade-off between optical absorption, interface recombination, and resistive losses. A multi-layer perceptron regressor was trained using simulation data and achieved strong predictive fidelity (R2 ≈ 0.98) with a mean absolute error below 0.3%. The resulting surrogate model rapidly identifies optimal structural configurations without requiring additional high-cost simulations, demonstrating a reduction of design time by more than an order of magnitude. The proposed workflow provides a transferable route toward digital-twin-driven photovoltaic design and offers practical guidance for high-performance PSC engineering with reduced material consumption and enhanced computational efficiency.

Open Access
Research article
Experimental Model of Direct Tensile Strength of Pyrite and Chalcopyrite Veins: Implications for Rock Mass Stability
ccatamayo barrios johnny-henrry ,
victor felix flores-moreno ,
josé agustín esparta-sanchez ,
amilcar tacuri-gamboa ,
jaime palomino-claudio ,
luis alfredo vargas-moreno ,
humberto pehovaz-alvarez ,
enrique guadalupe-gomez ,
jesus alberto torres-guerra
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Available online: 12-04-2025

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Despite their influence on the stability of underground excavations, mineralized veinlets, particularly those composed of pyrite and chalcopyrite, are often underestimated in traditional geomechanical models. The lack of experimental data on their tensile behavior under direct stress represents a critical gap in rock mass characterization. This study experimentally evaluated the direct tensile strength of pyrite and chalcopyrite veinlets from the El Teniente mine, in order to enhance the accuracy of geotechnical models for complex geological contexts. Following the Organization for Economic Cooperation and Development (OECD) 203 (2019) guidelines, a fully randomized experimental design was employed to conduct direct tensile testing of 19 veinlet samples. The results showed that chalcopyrite veinlets exhibited greater internal cohesion with significantly higher tensile strength, reaching up to 3.17 MPa, compared to pyrite veinlets of lower values. Furthermore, chalcopyrite veinlets demonstrated a more homogeneous and cohesive failure behavior compared to pyrite, which displayed greater surface roughness and interfacial failure. This study highlights the importance of incorporating veinlet mineralogy into geotechnical models to improve underground design and safety.

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Modern image processing systems deployed on embedded and heterogeneous platforms face increasing pressure to deliver high performance under strict energy and real-time constraints. The rapid growth in image resolution and frame rates has significantly amplified computational demand, making uniform full-precision processing increasingly inefficient. This paper presents a significance-driven adaptive approximate computing framework that reduces energy consumption by tailoring computational precision and resource allocation to the spatial importance of image content. We introduce a statistical importance metric that captures local structural variability using low-complexity deviation-based analysis on luminance information. The metric serves as a lightweight proxy for identifying regions that are more sensitive to approximation errors, enabling differentiated processing without the overhead of semantic or perceptual saliency models. Based on this importance classification, the proposed framework dynamically orchestrates heterogeneous CPU–GPU resources, applies variable kernel sizes, and exploits dynamic voltage and frequency scaling (DVFS) to reclaim timing slack for additional energy savings. The framework is validated through two complementary case studies: (i) a heterogeneous software implementation for adaptive convolution filtering on an Odroid XU-4 embedded platform, and (ii) a hardware-level approximate circuit allocation approach using configurable-precision arithmetic units. Experimental results demonstrate energy reductions of up to 60\% compared to uniform-precision baselines, while maintaining acceptable visual quality. Image quality is evaluated using both PSNR and the perceptually motivated SSIM metric, confirming that the proposed approach preserves structural fidelity despite aggressive approximation.
Open Access
Research article
Optimizing Da’wah Through the MASJIDA Application: A Cognitive Ergonomics Approach to Enhance User Experience
ririt dwiputri permatasari ,
m. ansyar bora ,
luki hernando ,
vitri aprilla handayani ,
taufiq rahman ,
larisang ,
m. ropianto ,
tommy saputra ,
fitri mehdini addieningrum ,
dukhroni ali ,
alhamidi ,
haidil fauzan ,
nur shilah ,
muhamad andrian yudhistira ,
shafira putri rheyna ,
fani rahma yanti ,
anisa fitrianti
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Available online: 12-30-2025

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This study investigates how cognitive ergonomics-based interface design can enhance user experience and reduce cognitive workload in digital da’wah applications, using the MASJIDA mobile application as a case study. While existing digital da’wah platforms primarily emphasize functional features and content dissemination, limited attention has been given to systematic evaluations of usability and cognitive load. To address this gap, this study integrates cognitive ergonomics principles into the design and evaluation of MASJIDA, a mobile application developed to support mosque management and congregational engagement. A pre-test and post-test experimental design was employed involving mosque administrators and congregants. System usability was measured using the System Usability Scale (SUS), while cognitive workload was assessed using the NASA Task Load Index (NASA-TLX). The results demonstrate a substantial improvement in usability, with SUS scores increasing from 55.1 to 79.3 for congregants and from 55.5 to 85.4 for mosque administrators. In parallel, NASA-TLX results reveal a significant reduction in mental demand, effort, and frustration, indicating lower cognitive workload after implementation. These findings confirm that applying cognitive ergonomics principles contributes not only to improved usability but also to more cognitively efficient user interactions. This study provides empirical evidence and analytical insights for the development of user-centered digital religious applications that balance functional effectiveness with cognitive accessibility.

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Functional plate is one of the most typical materials used for strengthening of reinforced concrete (RC) structures. This article focuses on using functional plates internally to improve the flexural response of RC beams. For this purpose, experimental and numerical investigations on the flexural behavior and ductility of steel-plated RC beams were conducted. Nine RC beams were cast and cured for 28 days. The steel plates were located at the tension side of the RC beams to investigate their effect on the flexural performance of the tested beams. To achieve the research objective, three configurations of the shape of steel plates were proposed, flat, curved, and rounded. The results demonstrate that using embedded steel plates is effective and significantly enhanced the flexural performance of concrete beams. The strengthening delayed the first cracking appearance and increasing of ultimate load up to 45% compared to the reference beam. Further, there was an improvement in ductility and stiffness behaviours by 202% and 46%, respectively, particularly for beams with constrained flat steel plates, which exhibited the highest performance gain. The experimental and finite element (FE) results showed a good agreement in terms of cracking behavior and with approximately 6% maximum ultimate load difference.

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This work provides a comprehensive evaluation of the effect of shot peening (SP) time on the mechanical, electrochemical, and surface properties of AA6061-T6 aluminum alloy tested in an alkaline chloride medium (pH = 9). The specimens were subjectively peened for varying durations from 0 to 12 min. The subsequent effects on tensile strength, fatigue life, corrosion resistance, surface roughness, and microhardness were studied. The results showed that a SP time of 9 min increased the tensile strength and hardness through strain hardening, dislocation accumulation, and establishment of compressive residual stress. The formation of a strong passive layer and delayed crack initiation also help make the material more resistant to corrosion and fatigue. However, peening for more than 9 min resulted in rough and localized damage and slightly reduced the mechanical performance. The results show that a 9-minute SP duration is the ideal method to strengthen the surface and maintain a strong structure, which makes AA6061-T6 parts last longer under harsh conditions.

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This article presents a mathematical analysis of 3D Williamson nanofluid flow over a stretching Riga plate in a Darcy-Forchheimer porous medium. The model incorporates thermal radiation, heat generation/absorption, and the Buongiorno nanofluid framework with Cattaneo-Christov double flux. Similarity transformations reduce the governing PDEs to ODEs, solved using Mathematica's NDSolve. Graphs and tables illustrate the effects of key parameters on velocity, temperature, concentration, skin friction, Nusselt number, and Sherwood number. The x-direction velocity increases with the modified Hartmann number ($Ha$ = 0.5–2.0), enhancing skin friction by 20–30%. Higher thermophoresis ($Nt$ = 0.1–0.5) elevates temperature and concentration by 15–20% and 10–14%, respectively. Brownian motion ($Nb$ = 0.1–0.5) boosts mass transfer, increasing Sherwood number by 7–9%. Increasing heat and mass relaxation parameters ($\gamma_1$, $\gamma_2$ = 0.1–0.5) accelerates Nusselt and Sherwood numbers by 5–10%. Results correlate well with prior studies, providing a basis for magnetohydrodynamic (MHD) cooling systems, polymer processing, and biomedical simulations involving non-Newtonian fluids.

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The Internet of Things (IoT) consists of a large interconnected system of devices that automatically gather, analyze, and transfer data. Securing the integrity and privacy of these devices is a significant challenge due to their distributed and heterogeneous nature. To address this issue, this paper presents a hybrid security framework that is designed in two phases: Node Topology Measures-based Vulnerable Node Detection (NTMVND) and Adoption-based Differential Evolution (ADE) with Elicited Genetic Algorithm (ADE2GA). The NTMVND component detects vulnerable nodes using important topological measures such as node degree, betweenness, clustering coefficient, and centrality to remove potential risks in the communication network. The ADE2GA component produces optimal and secure paths for data transmission by leveraging the adaptive exploration characteristics of Differential Evolution (DE) and the exploitative learning capabilities of the Genetic Algorithm (GA). The simulation results in Network Simulator-2 shows that the ADE2GA model performs best, resulting in 39% reduction in the end-to-end delay and 26% savings in energy consumption, while producing a 41% increase in throughput and a 10% increase in packet delivery ratio compared to standard Particle Swarm Optimization (PSO) and Differential Evolution with Genetic Algorithm (DEGA) models. The results substantiate the proposed framework's capability for promoting improved integrity, privacy, and efficiency in IoT settings.

Open Access
Research article
Validated Numerical Model of a Lightweight Trickle-Flow Solar Water Heater for Tropical Applications
nugroho agung pambudi ,
dony marly martiawan siregar ,
desita kamila ulfa ,
danny rizki sofyan permana putra
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Available online: 12-30-2025

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The increasing global energy crisis and concerns about environmental impacts are driving the development of efficient and low-cost renewable energy systems. Solar water heaters (SWH) are an alternative, specifically in tropical countries such as Indonesia, which receive solar radiation intensity of 4–6 kWh/m$^2$/day. Therefore, this study aimed to model the thermal performance of trickle-flow SWH using a lightweight composite material called polymethyl methacrylate (PMMA) as cover and galvalume for the heat absorber plate, which has previously been validated through experiments. The simulation model was developed using a transient lumped-parameter energy balance method and was implemented in Python with minute-by-minute interpolated meteorological data. Model validation was conducted by comparing simulated and experimental inlet and outlet temperatures. It reproduced the main temperature trends and peak values observed in the experiments. Statistical evaluation further indicated a high level of accuracy, with root-mean-square error (RMSE) values of up to 0.81℃ and a coefficient of determination ($R^2$) of 0.986 for outlet temperature. Additional parametric analyses showed the effects of flow rate and tank volume on thermal efficiency. These effects were visualized using efficiency contour plots, while confidence bands were applied to present simulation uncertainty. In general, the results confirmed the feasibility of using lightweight materials in solar collectors and showed the capability of numerical-statistical models for performance prediction as well as design optimization. These findings supported the development of efficient and low-cost SWH systems for tropical regions.
Open Access
Research article
Experimental and Theoretical Analysis of the Effect of Pipe Material on Major Head Losses in Pipes
intesar k. atiyah ,
nadya husain muslim ,
nihad a. al-bughaebi ,
audai hussein al-abbas
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Available online: 12-30-2025

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This paper experimentally and analytically investigated the effect of pipe wall roughness on hydraulic loss generation in turbulent flow. The study used straight circular pipes with same geometrical dimensions (length = 5 m and internal diameter = 4 cm). Four different metals used such as cast iron, galvanized steel, stainless steel, and copper. Experiments were performed at a flow Reynolds number ($Re$) ranging from approximately 3.4 × 10$^4$ to 5.1 × 10$^4$. The volumetric flow rates were in a range of 80–120 L/min with pressure drop and head loss measured by using a calibrated laboratory setup. The analytical prediction of the head‐loss was conducted using Darcy-Weisbach equation with Colebrook-White friction factor correlations. From the literature data, roughness heights were used to predict the head loss. Experimental and theoretical results can be directly compared, providing an evaluation of model predictiveness accuracy. The frictional head losses depended on the pipe roughness; and it increased from cooper (2.4–2.8 m) to cast iron (3.8–5.2 m), with intermediate values for galvanized and stainless steel, respectively. The friction coefficient ratio measured for the cast iron of 0.031 and copper of 0.018, and this is to indicate different surface roughness. Observed and predicted head losses were in agreement, with errors up to 6–7% relative deviation for smooth-lined pipes, and higher than 8% for roughed ones. The results emphasized the importance of relative roughness in turbulent flow and substantiate the validity of established friction-loss relationships for better engineering design. Model selection and friction loss prediction principles can be practically exploited to aid energy-efficient pipe network design, as well as encourage the recognition of predictive uncertainty. Overall, the study bridges experimental validation and analytical modeling, offering benchmarks for accurate hydraulic analysis under realistic operating conditions.

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Increasing energy requirements in hot regions highlight the need for sustainable thermal management technologies. A promising passive cooling solution is Earth-Air Heat Exchanger (EAHE) that use the relatively stable temperature of the subsurface soil to pre-cool air supplied to indoor spaces. This study investigates the thermal and hydraulic performance of an EAHE coupled to a greenhouse in severe summer conditions in Nasiriyah city, southern Iraq, experimentally. The system was designed to evaluate its effectiveness in moderating ambient temperature extremes and reducing mechanical cooling energy requirements. Experimental results during July–October showed that the EAHE outlet air temperature stayed between 31 and 38°C despite ambient temperature exceeding 50°C, indicating a stable thermal response of the buried exchanger. The greenhouse air temperature was maintained at 34–40°C during peak daytime hours and decreased to about 29–33°C during the remaining operating periods, confirming improved internal thermal conditions. The thermal effectiveness ($\varepsilon$) ranged from 0.68 to 0.75, and the average temperature drop ($\Delta{T}$) was above 13°C throughout the test period. Furthermore, pressure drop and fan power increased with airflow velocity, consistent with a turbulent flow regime. The EAHE delivered 2011–2942 W of cooling with 42–144 W of fan power; an indicative baseline from a comparable 50 Hz mini-split (8500–11000 Btu/h) shows a rated electrical input of ~880–1070 W, highlighting the low electrical demand of the EAHE fan (catalog-based context, not a side-by-side test). In summary, the EAHE–greenhouse system demonstrates a viable, energy-efficient pilot-scale option for passive cooling in hot climates, with potential for agricultural applications subject to site-specific sizing and installation constraints.

Open Access
Research article
Low-Cost IoT-Cloud Dual-Meter System for Real-Time Electricity Theft Detection
jamil abedalrahim jamil alsayaydeh ,
mohd faizal yusof ,
ahmed hussein ahmed ,
rostam affendi bin hamzah ,
Safarudin Gazali Herawan
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Available online: 12-30-2025

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Electricity theft is a major contributor to non-technical losses (NTL) in distribution networks, causing substantial revenue losses and degrading grid reliability. Conventional approaches such as periodic inspections and smart-meter-only monitoring often fail to detect sophisticated theft behaviors, including meter tampering and illegal line tapping. This paper presents a low-cost IoT-cloud dual-meter system for real-time electricity theft detection and response. The proposed design measures energy at two points: (i) the incoming supply line and (ii) the consumer-side meter output. An embedded controller acquires both streams and uploads the readings to a cloud platform, where a discrepancy-based detection module continuously compares delivered and metered energy within a configurable tolerance to account for normal losses and sensor uncertainty. When persistent abnormal discrepancies are identified, the system issues immediate alerts to utility operators and can optionally trigger a local relay to disconnect the load. A prototype implementation was evaluated under controlled scenarios that emulate normal operation and theft conditions. The system achieved approximately 95% detection accuracy, maintained false alarms below 5%, and detected small theft levels down to about 10 W in the test setup. The bill of materials indicates an estimated unit cost of approximately USD 30–50, supporting scalable deployment in cost-sensitive environments.

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Mobile ad hoc networks (MANETs) are inherently susceptible to malicious packet-dropping attacks, including black holes, gray holes and selective forwarding attacks that greatly decrease the reliability and performance of MANETs. Current solutions for detecting malicious attacks have large false-positive rates because they often confuse an intended malicious drop with an unintended loss caused by limited resources, traffic congestion and/or the impairment of wireless channels. In addition, current solutions can be vulnerable to acknowledgment (ACK) forgery attacks and consume considerable amounts of energy in continuously monitoring packets. The authors present a comprehensive four-phase framework that synergistically combines route qualification based on available resources, password-based mutual authentication using chaotic map Diffie Hellman password authenticated key exchange (CMDH-PAKE), authenticated digested ACKs based on counters and selectively activating promiscuous monitors to accurately detect and mitigate malicious packet-dropping attacks in MANETs at low power. The authors’ solution identifies and excludes honest-but-constrained nodes during route discovery by estimating buffer congestion using exponentially weighted moving average (EWMA) and modeling energy feasibility, thus reducing false positives by up to 73%. Binding keys between cryptographic sessions reduces the potential for ACK forgery and impersonation attacks, and aggregated window-based ACKs reduce energy use by 85%, relative to per-packet ACKs. Selectively activating monitors on demand using only cryptographic evidence of anomalies minimizes the energy used while still maintaining a high level of detection accuracy (above 96%). Simulation results using Network Simulator 3 (NS-3) indicate that the authors’ solution has a higher packet delivery ratio (94.2%), shorter end-to-end delay (127 ms), and much lower false-positive rate (3.1%) than other approaches; in addition, the authors’ solution uses about 42% less energy than always-on monitoring approaches.

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The increasing adoption of electric vehicles with fast-charging capability has intensified thermal challenges in power cables, potentially leading to localized overheating and reduced system reliability and service life. To address this issue, an integrated framework combining experimental measurement and data-driven analysis was developed to identify and predict thermal behaviour in critical electrical components of electric vehicles. A laboratory-scale electric vehicle powertrain was constructed to replicate representative operating conditions. Infrared thermography was employed together with synchronized electrical measurements to capture the coupled electrical–thermal response of the system. The powertrain was tested under variable mechanical loads ranging from 0% to over 80% and under constant-current operation at 15 A for 30 minutes. Passive thermal management using phase change materials, specifically beeswax and paraffin, was evaluated to assess its effectiveness in mitigating temperature rise. In addition, a lightweight artificial neural network (ANN) model was developed to predict the temperatures of thermally critical components. Thermographic results showed that thermal stress was spatially concentrated at specific interfaces. At maximum load, the temperatures of the power cable downstream of the main switch, the motor cable, and the connector reached 41.2 ℃, 39.7 ℃, and 47 ℃, respectively. Analysis of battery charging behaviour revealed a strong correlation between battery temperature and charging current, with a correlation coefficient of 0.95. When phase change materials were applied, the battery temperature rise was reduced to approximately 35.2–35.5 ℃, compared with 36.7 ℃ in the absence of phase change materials, and voltage stability was improved. The ANN demonstrated high predictive accuracy, with R² values of 0.978 for main switch temperature, 0.969 for connector temperature, and 0.962 for motor cable temperature, corresponding to prediction errors within ±2.5 ℃ across all load conditions. These findings indicate that an integrated experimental and predictive diagnostic approach can effectively support thermal management and early risk identification in high-current electric vehicle power cable systems.

Open Access
Research article
Numerical Modeling of Supersonic Flow Through a Ramjet Nozzle Using Ansys Fluent
mustafa abdulsalam mustafa ,
atheer raheem abdullah ,
mohammed mousa al-azzawi
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Available online: 12-30-2025

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A ramjet nozzle was designed for supersonic operating conditions and evaluated numerically using Ansys Fluent 16.1 over a range of chamber-to-ambient pressure ratios. The nozzle geometry was generated to achieve smooth, shock-free expansion under supersonic outflow conditions using the characteristic curve method at a specific nozzle chamber pressure and temperature using Matrix Laboratory (MATLAB) and then validated by comparing the numerical predictions with available experimental data. The results show that a pressure ratio of 57 provides the highest thrust coefficient (TC), while lower ratios lead to over-expanded flow and higher ratios to under-expansion with increased shock losses. Contours of pressure, temperature, and Mach number confirm the expected supersonic flow structure and demonstrate that the nozzle achieves optimum performance under the identified conditions.

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This study investigates whole-body vibration (WBV) exposure in commuters on Iraqi roads. Measurement of vertical, lateral and longitudinal acceleration was obtained on urban arterials, rural two-lane roads and intercity highways using a low-cost measurement setup that incorporates an MPU6050 accelerometer and ESP32 microcontroller. Data was analyzed in accordance with ISO 2631-1, i.e. frequency-weighted root mean square (RMS) acceleration, vibration dose values (VDV) or power spectral density analysis. The results show that vertical vibration (z-axis) predominates in WBV, with maximum energy occurring within the 3–6 Hz frequency range, which is known to correspond to the most responsive frequency range of the human body. The International Roughness Index (IRI), a measure of pavement texture, was highly associated with RMS (r = 0.66), with speed having an additional enhancing influence. Cars and SUVs on intercity highways stayed in “comfort” or “light comfort” zones, whereas heavy trucks on rural roads often encountered “uncomfortable” levels, with VDV up to 16.9 m/s$^{1.75}$. These results reveal a growing need for pavement rehabilitation of the Iraqi arterial and rural road networks, better enforcement of axle-load limits and the adoption of WBV monitoring in sensor-based management of road infrastructure. The research outcomes can serve as a useful reference for enhancing transport and occupational health protection policy making in Iraq.

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Liquid level control plays a crucial role in process industries, where accurate and stable regulation is required to ensure operational safety and process efficiency. In practice, nonlinear tank dynamics and wide operating ranges often degrade the performance of conventional proportional-integral-derivative (PID)-based control strategies, leading to excessive overshoot, oscillations, and prolonged settling times. Although various advanced control techniques have been proposed, many of them rely on complex tuning procedures or heuristic design, which limits their practical applicability. This paper proposes a mass-balance-based liquid level control strategy that directly exploits the physical relationship between inflow, outflow, and liquid level. The proposed method introduces a mode-switching mechanism that distinguishes between transient and steady-state operating conditions. During transient operation, the control valve is driven to its saturation limits to accelerate level correction, while steady-state regulation is achieved by balancing inflow and outflow to maintain mass equilibrium. Unlike conventional PID controllers, the proposed approach does not require parameter tuning, system identification, or optimization procedures. Simulation studies are conducted on nonlinear tank systems to evaluate the effectiveness of the proposed strategy. The results demonstrate that the proposed method achieves fast setpoint tracking with zero overshoot and reduced settling time compared with conventional proportional (P), proportional-integral (PI), and PID, and cascade control schemes. Quantitative performance comparisons further confirm the robustness and practical advantages of the proposed control strategy for nonlinear liquid level control applications.

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External dynamic circumstances, especially vertical vibrations brought on by uneven road surfaces and engine activity, have a major impact on a vehicle’s radiator performance. To increase cooling effectiveness and improve thermal management in automobiles, it is essential to comprehend how these vibrations affect heat transmission. This paper proposes using methods to enhance vibration-enhanced heat transfer and increase volumetric flows on a finned-tube car radiator. The radiator’s thermal performance is improved through heat dissipation. The experiment was conducted at volumetric flows (0.5, 0.75, 1, and 1.25 liters per minute (LPM)) and frequencies (0, 5, 10, and 15 Hz). In terms of enhancing vibration-enhanced thermal performance, this study varies from other experimental investigations, particularly with regard to the frequency range employed and volumetric flow. We investigated the impact of vibration coinciding with volumetric flow and pellet behavior under operating settings more similar to those in which cooling systems function. This topic has not been fully explored before and does not constitute redundancy; instead, it solves limits by experimentally examining how vibration and realistic operating circumstances work together to improve thermal performance. The highest increase in Nusselt number enhancement was 23.4% observed on the water side, while the highest enhancement was 12.99% observed on the air side. Increased vibration led to increased heat flow, reaching its maximum 773.85 W/m2 at frequency 15 Hz and volumetric flow 1.25 LPM. The vibrational disturbance further enhanced heat exchange between adjacent surfaces.

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The efficiency of the multi-effect distillation (MED) system is highly influenced by its operational parameters during operation. Similarly, the efficiency of the compact MED is significantly affected by its operating conditions. One of the operating parameters of MED is the pressure applied to each component. In this study, a compact MED experimental test was conducted using sub-atmospheric pressure in a freshwater tank. The freshwater tanks are designed to hold the freshwater produced by the compact MED. The installation of the freshwater tank is designed to connect to a vacuum pump to create sub-atmospheric conditions inside the freshwater tank. The highest experimental results show that under a freshwater tank pressure of 70 kPa, 368.5 mL of freshwater can be produced from 500 mL of seawater tested in a boiler at a pressure of 151.3 kPa. Based on these experimental results, sub-atmospheric pressure inside the freshwater tank can influence the output of the compact MED freshwater.
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