Engineering

Abstract: Intense rainfall, and the resulting increase in ground saturation can significantly modify the mechanical performance of rock masses in natural slopes. This is particularly important if material fractured is present. Extended infiltration accelerates material degradation, reduces shear strength along discontinuities, and increases pore-water pressures, reducing effective stresses, and in turn, raises the probability of large-scale landslides. Evaluating these processes requires a thorough understanding of the geotechnical and hydrogeological properties controlling slope response, as well as reliable stability assessments under varying saturation conditions, including factor of safety and deformation estimates. However, in engineering practice most of the time ground exploration is limited, and laboratory testing in rocks only provides an estimation of the rock performance expected in the slope within a reduced zone. This study examines a landslide triggered in a shale–limestone slope after heavy rainfall. A back-analysis was performed within a performance-based design (PBD) framework to reproduce the observed failure and, thus, characterize representative geomechanically parameters for design validation, using three-dimensional finite difference modeling. The performance under monotonic and seismic loading of a tunnel built adjacent to the slope was analyzed as a mitigation measure, thus establishing its technical soundness, from both state limit of failure and service, of the tunnel-slope system.

Abstract: Lithium-ion batteries are prone to internal short circuits and subsequent thermal runaway under compression and impact loads during electric vehicle crashes, posing a critical safety challenge for the industry. However, existing studies lack systematic comparative analysis between quasi-static and dynamic loading conditions. In this study, 26 Ah ternary pouch lithium-ion batteries were used as research objects. A test platform for synchronous acquisition of mechanical load, electrical voltage and thermal temperature was established. Quasi-static compression and drop-weight impact tests were conducted to investigate the effects of indenter diameter, impact velocity and state of charge (SOC) on the multiphysics responses of batteries. The results show significant differences in failure modes between the two loading conditions: quasi-static loading causes progressive plastic deformation and stable short-circuit voltage decay, while dynamic loading induces brittle shear fracture and soft short-circuit voltage rebound. Under non-thermal runaway conditions, the temperature rise amplitude under dynamic impact is approximately 20% higher than that under quasi-static compression. High SOC alters the heat release pathway during thermal runaway, leading to deviations in surface temperature measurements. These findings provide critical experimental support for the crash safety design of power batteries and the formulation of thermal runaway prevention and control strategies.

Abstract: Emerging technologies and cyber-physical systems have led to the development of complex mathematical models described by differential equations with multiple fractional orders. In this regard, this paper investigates the stability of control systems for this class of models, defined by state equations with multiple fractional orders ranging between 0 and 1. Matrix criteria and comparison principle for linear and nonlinear autonomous systems of different fractional orders are developed based on generalized Lyapunov functions for differential equations with multi-order fractional exponents. The results are extended to non-autonomous linear or with nonlinear components systems of different fractional orders. The application of the Yakubovich-Kalman-Popov lemma, adapted for this class of systems, allows us to obtain new stability criteria presented as frequency criteria and represented graphically by familiar frequency plots similar those of the Nyquist or Popov type. Numerical applications illustrate these results such as models of complex human-machine systems described by state equations of multivariable fractional orders. An analysis of the advantages of the proposed methods compared to procedures and techniques used in other papers regarding the study of multi-order fractional exponent systems is presented. It is demonstrated that the proposed methods minimize the computational effort required for stability criteria.

Abstract: In Jordan, the construction industry and businesses are burdened by the high prices of materials in terms of extraction, production, transportation, and purchasing, as well as the volatility of their market value. The environment is primarily affected by construction and demolition activity since the construction sector in Jordan is based on a linear economy model and does not rely on the circular economy (CE) by reusing or recycling building materials rather than discarding them. Therefore, this study aims to develop a CE framework for managing construction waste in residential buildings during the construction phase and facilitating the adoption of the proposed model within the construction sector in Jordan. Therefore, a questionnaire was distributed to 31 experts, the results were analyzed, and the Delphi technique was then applied to validate the proposed framework and study findings. The findings indicate that the CE contributes to minimizing construction waste. The researcher sought to identify the most significant challenges hindering the implementation of the CE. The most influential challenges were low demand for reused or recycled materials, limited stakeholder awareness, and difficulties in disassembly. Furthermore, the results indicated use of visual management and 5S techniques, the use of BIM to map materials and components for circular lifecycle planning, and offering tax incentives and grants for using recycled materials are the most important strategies for minimizing construction waste. This study contributes to minimizing construction waste and advancing sustainable development, while also supporting Jordan’s Vision 2025 as outlined by the Jordanian government and the Ministry of Environment.

Abstract: Programmed conservation of heritage buildings requires assessment tools capable of iden-tifying vulnerabilities in a systematic and decision-oriented manner. This study proposes and applies a methodology for calculating the vulnerability index of the National Theatre of Costa Rica, with the aim of establishing a technical baseline for monitoring, prioritizing interventions, and supporting long-term conservation management. The method struc-tures vulnerability through four dimensions (systems, environment, use, and urban pres-sure), each subdivided into specific risk variables weighted through the Analytic Hierar-chy Process (AHP) and pairwise comparison matrices. The building was assessed through 33 spaces grouped into 17 zones, based on two on-site evaluation campaigns, and the re-sults were consolidated into a global assessment matrix. The findings indicate an overall low vulnerability index for the building (1.391), with similarly low values recorded for systems (1.549), use (1.450), environment (1.268), and urban pressure (1.198). However, the South Façade (1.824) and the Foyer (1.778) reached medium vulnerability levels, while several additional spaces were close to that threshold. The results suggest that use-related conditions exert the greatest influence on the overall index, whereas systems-related is-sues—particularly electrical installations—remain a relevant field for intervention. The study supports the applicability of the proposed method as an objective instrument for programmed conservation of built heritage.

Abstract: p-GaN gate enhancement-mode GaN HEMTs are promising normally-off power devices, but their high-temperature reliability is strongly affected by the gate contact scheme. This study compares Pd-ohmic and Ni-Schottky p-GaN gate HEMTs fabricated on the same GaN-on-Si epitaxial platform by combining temperature-dependent electrical characterization, post-temperature-dependent-test (TDT) room-temperature recovery analysis, and thermoreflectance thermal mapping. Electrical measurements were performed from room temperature to 500 °C using gate leakage, transfer, and output characteristics, while thermal maps were obtained before and after TDT under identical bias conditions. The Pd-ohmic devices exhibited higher initial current drive but larger operating gate-current penalty and stronger degradation of normalized on-state characteristics at elevated temperature. After TDT, reduced transconductance and maximum drain current were accompanied by weaker active-channel heating, indicating degradation-type cooling associated with reduced gate-channel modulation efficiency. In contrast, the Ni-Schottky devices showed lower gate-current penalty and better normalized output retention up to approximately 300 °C; however, post-TDT increases in transconductance and drain current occurred together with degraded subthreshold swing and persistent localized heating, indicating apparent on-state activation with weakened gate/depletion control. These results show that p-GaN gate reliability should be assessed through coupled electrical and thermal signatures rather than single electrical or thermal metrics.

Abstract: Food fraud is a persistent global threat estimated to cost the food industry over USD 30 billion annually. The integration of artificial intelligence (AI) with analytical instrumentation has generated significant research activity directed at developing detection systems capable of identifying adulteration, mislabeling, and substitution across diverse food matrices. This systematic review critically examines the extent to which AI-assisted instrumental technologies contribute to food fraud prevention, and identifies the structural limitations that constrain their real-world implementation. A systematic search of peer-reviewed literature published between 2021 and 2026 yielded 72 eligible studies after application of predefined inclusion criteria. Studies were required to report quantitative performance metrics (accuracy, R², RMSE, AUC, sensitivity, specificity), describe methodological limitations, and mention laboratory or industrial implementation contexts. Data were extracted into a structured seven-sheet workbook covering study characteristics, instrumental technologies, AI architectures, performance metrics, industrial validation status, implementation evidence, and methodological quality. The corpus reveals a systematic pattern of high reported analytical accuracy—frequently exceeding 95% and in many cases reaching 100%—under controlled laboratory conditions. However, 75% of studies (54/72) conducted no external validation, 100% of studies reported no pilot-scale or routine monitoring application, and no study achieved inter-laboratory validation. The predominant technology was NIR spectroscopy (26/72 studies, 36%), followed by gas chromatography-based systems (14/72, 19%) and electronic noses (8/72, 11%). Classical machine learning—predominantly SVM, Random Forest, and ANN—dominated methodological approaches (43/72, 60%), with deep learning architectures accounting for 26% of studies. Technology Readiness Levels were unreported in 97% of studies. Methodological quality was predominantly moderate (42/72 studies scoring 3/5), with 19 studies scoring 2/5 and only one achieving the maximum score. This review identifies a structural gap between detection and prevention as the central finding: the scientific literature consistently demonstrates high analytical precision in laboratory settings while providing minimal evidence of real-world industrial deployment, regulatory integration, or measurable impact on the prevention of food fraud events. The findings demonstrate that the limitation is not primarily technological but systemic, highlighting the need for a paradigm shift from performance-driven research toward validation-driven, deployment-oriented frameworks.

Abstract: An approach for the control of linear control systems with a single time-delay is proposed. The main contribution is the inclusion of a symmetric-injection virtual reference trajectory into the controller to render stability robustness of single-delay linear control systems. The dynamics of the virtual trajectory is included into the closed-loop dynamics allowing theoretical computation of the critical time-delay before losing stability. Moreover, an energy-based symmetry interpretation of the proposed approach is drawn. Numerical simulations considering stable and unstable linear systems are shown, and experiments to control a DC-motor with time-delay measurements validate our proposal.

Abstract: Emerging materials often face challenges in market adoption due to limited comparability and reliability of measurement-based material information, despite their potential to drive technological innovation. While standardization is widely recognized as an important mechanism for market diffusion, existing approaches provide limited insight into how material specifications facilitate the comparative evaluation of material characteristics and their use in market decision-making. This study proposes a complementary perspective that interprets standardization as an infrastructure for organizing the generation, sharing, and evaluation of measurement-based material information across industry, standard development organizations (SDOs), and markets. Within this framework, the study distinguishes between two complementary types of standards for material specifications. Type A standards enable the structured disclosure of measured characteristic values and associated measurement uncertainties, allowing application-specific evaluation without predefined acceptance criteria. In contrast, Type B standards define predefined characteristic values and compliance criteria, providing a basis for conformity assessment, certification, and quality assurance. These two types may be understood as complementary mechanisms that fulfill different functions of comparability and compliance under varying technological and market conditions in emerging material systems. Consequently, they contribute to both innovation-oriented market evaluation and quality-assured market acceptance.

Abstract: This work deals with the time-domain analysis of asymmetrical faults in three-phase systems. Conventional three-phase analysis provides steady-state solutions for asymmetrical faults. Transient analysis, however, is usually performed by resorting either to oversimplified approximate circuits, or to numerical methods. In this paper, a rigorous analytical methodology based on the time-domain Clarke transformation is presented for the most common asymmetrical faults in three-phase systems. In particular, it is shown that asymmetrical faults result in circuit coupling in the Clarke equivalent circuits. Circuit representation of coupling is also derived in the paper. Coupled equivalent circuits allow rigorous analytical solution of transients in case of asymmetrical faults. The analytical results derived in the paper are validated through proper numerical simulation of faulted radial systems.

Abstract: In the hyper-arid climate of Riyadh, Saudi Arabia, the building envelope represents the most critical determinant of energy demand and occupant comfort. This study evaluates the environmental and energy performance of a 6,581m2 mixed-use development through an experiential learning framework, where students utilized Sefaira (Ener-gyPlus/Radiance engines) to bridge the gap between theoretical architectural design and national code compliance. This pedagogical approach allowed for the practical application of Building Energy Modelling (BEM) principles to a real-world capstone project. A baseline analysis conducted in accordance with the Saudi Building Code (SBC 601) re-vealed a high Energy Use Intensity (EUI) of 139 kWh/m2. yr, driven primarily by solar heat gains and an "overlit" floor plate as noted above exceeded Annual Sunlight Exposure (ASE) thresholds. To mitigate these deficiencies, students implemented a series of passive interventions, including the optimization of glazing U-values (0.5~W/m²·K), reduction of Solar Heat Gain Coefficient (SHGC to 0.20), and the integration of external shading fins. Post-intervention results demonstrated a significant EUI reduction to 130 kWh/m²·yr" to "a 6.95% reduction in EUI from 139 to 130 kWh/m²·yr, equating to 63,659 kWh in annual energy savings. Furthermore, daylighting analysis confirmed a more uniform distri-bution and the successful mitigation of disability glare. The findings validate that ex-periential learning in performance-driven envelope optimization is essential for de-veloping the technical proficiency required to achieve full SBC compliance and opera-tional efficiency in hot-arid regions.

Abstract: Limited access to clean water and reliable electricity infrastructure remains a major challenge in many remote regions of Indonesia, particularly for building‑scale domestic use. Conventional water treatment systems are often constrained by high operational costs and dependence on grid power, highlighting the need for sustainable and autonomous infrastructure solutions. This study presents the design, development, and performance evaluation of an integrated solar‑powered clean water treatment system for smart building applications in remote areas using a Research and Development (R&D) approach. The proposed system combines off‑grid polycrystalline photovoltaic panels with a multi‑stage water treatment process consisting of a floss (mud) filter, activated carbon filter, water hyacinth cellulose bio‑filter, ultraviolet (UV) sterilization unit, storage tank, and an IoT‑based real‑time water quality monitoring system. System performance was evaluated through microbiological, physical, and chemical water quality testing, with monitoring conducted via Wi‑Fi‑enabled sensors connected to the Blynk platform. The results demonstrate substantial improvements in treated water quality. Escherichia coli and total coliform bacteria were eliminated (100% reduction). Total dissolved solids (TDS) decreased from 450 mg/L to 218 mg/L (51.6%), and dissolved manganese was reduced from 30 mg/L to 0.01 mg/L (99.97%), while nitrate levels decreased by 50%. Water pH and temperature remained stable and within regulatory limits. All treated water parameters complied with national clean water standards for hygiene and sanitation. The system operated independently using solar energy and achieved a clean water production capacity of 1,000–1,500 L/day. These findings indicate that the proposed system is a feasible, cost‑effective, and sustainable civil engineering solution for clean water infrastructure in remote building environments.

Abstract: Double-sided solar greenhouses are recognized as energy-efficient agricultural facilities that significantly enhance land utilization and thermal performance through their unique double-sided lighting design, thereby promoting crop growth. However, challenges persist regarding insufficient heat storage capacity and suboptimal thermal environments within the shaded shed during the winter and spring seasons. To fully exploit the advantages of this greenhouse type, this study proposes a structural optimization methodology utilizing Computational Fluid Dynamics simulation. A CFD model was developed and validated against experimental data to ensure accuracy. Subsequently, the influence of key parameters, including roof geometry and wall thickness, on the internal photothermal environment was systematically analyzed. The results demonstrate that the 370 mm thick wall configuration achieves a daily peak temperature approximately 2°C lower than the 240 mm wall, indicating a more uniform spatial distribution, while exhibiting a nighttime temperature increase of up to 2.5°C, thereby confirming superior thermal insulation properties. Furthermore, the presence of a rear roof structure is critical for nighttime heat retention, maintaining a minimum temperature of approximately 5°C compared to 2°C in greenhouses lacking this feature, with a maximum temperature difference of 4.2°C, effectively optimizing temperature uniformity. Based on these findings, this research provides a robust theoretical foundation and technical support for the structural optimization of double-sided solar greenhouses and the advancement of facility agriculture.

Abstract: Ground failure during major seismic events associated with soil liquefaction can lead to major structural damage in both the columns and the bridge upper deck, due to large seismic-induced displacements in the support foundation. Liquefaction-driven ground motion incoherence during the dynamic event, and permanent soil deformations are key variables in the observed damage. This paper summarizes a numerical study of an alternative bridge foundation design proposed to reduce support displacements and bearing capacity failure during and after an earthquake, as well as relative settlement associated with partial loss of bearing capacity when the bridge column is founded on a potential liquefiable layer. Three-dimensional numerical models were developed using FLAC3D. The seismic environment was characterized by a uniform hazard spectrum, UHS, for intraplate and interplate earthquakes, as presented in the current construction Mexico City regulations. Initially, a one-dimensional analysis was performed using SHAKE to evaluate liquefaction susceptibility. Results show that the structured cell foundation reduces excess pore pressure generation by up to 42% compared to shallow foundations and 25% compared to pile systems. This improvement is associated with (i) restriction of cyclic shear strain, (ii) modification of deformation patterns, (iii) partial hydraulic isolation of the confined soil, and (iv) preservation of effective stresses during shaking. Additionally, the system reduces shear strain localization and decreases acceleration transmitted to the superstructure by up to 25%. The findings demonstrate that structured confinement systems can significantly alter the mechanisms governing liquefaction, offering a promising alternative for bridge foundations in seismic regions.

Abstract: Channel estimation is important for Orthogonal Frequency-Division Multiplexing (OFDM) in wireless channel communication and requires algorithms that offer the best accuracy while at the same time have very low computational and runtime complexities. Newtonised Orthogonal Matching Pursuit (NOMP) is a promising algorithm for channel estimation; however, it suffers from high computational complexity due to repeated refinement and least-squares updates. In this paper, we propose a low complexity NOMP variant that reduces the dominant computational cost through three modifications: (i) a residual energy-based stopping criterion for NOMP to avoid expensive CFAR evaluation, (ii) a partial cyclic refinement with frozen atoms, and (iii) approximate one-sweep per atom least-squares updates. Complexity analysis shows a reduction from O(K³) to O(KN) in the gain update and from O(K²N) to O(KN) in refinement. Simulation results show that the proposed method achieves ∼87% reduction in runtime, while the symbol error rate (SER) performance is comparable to classical NOMP and outperforms Oversampled OMP at high signal-to-noise ratio (SNR). These results show that NOMP can be computationally efficient for OFDM systems without sacrificing estimation accuracy.

Abstract: This study proposes a reproducible exploratory framework to link long-term territorial development with electricity demand in data-scarce contexts, and applies it to Ecuador’s Costa region. The pipeline combines three commonly available input streams: periodic census microdata, an official demand series, and macroeconomic aggregates. Socioeconomic heterogeneity across five non-uniform census rounds (1974, 1982, 1990, 2001, 2010) is summarized through Principal Component Analysis (PCA), and territorial indicators are projected to the demand horizon using low-order polynomial functions. Eleven regression specifications are compared on a log-transformed demand variable, and a rollingorigin backtesting scheme plus a 2020–2024 holdout are used for validation. The selected Trend OLS log model attains R2 = 0.551 and MAPE = 6.08%, and projects a regional demand of approximately 6,940 MW by 2050, equivalent to a compound annual growth rate of 3.45%. Beyond the Ecuadorian case, the results show that transparent, low-data pipelines based on harmonized census information, macroeconomic drivers and simple regression models can provide defensible medium- and long-term demand signals for planners in other emerging economies with limited high-frequency data.

Abstract: Events such as landslides and slope failures happen suddenly and can be catastrophic. To predict the onset of such events, as well as the flow and final deposition of the material, engineers make use of numerical modeling techniques. These events are associated with large deformation and mesh-based methods, such as the finite element method, are not capable of modeling them due to mesh distortion. The material point method (MPM) is a particle-based continuum method capable of modeling large deformation and material flow. In this paper, MPM is used to model the sudden and dynamic flow of material by modeling the collapse and runout of a non-cohesive sand column. The results from two- and three-dimensional models are compared to experiments, showing that MPM accurately predicts the free-surface profile of the material during collapse. Furthermore, the model accurately predicts the runout distance with an error of less than 5%.

Abstract: To alleviate the shortage of natural river sand and promote the utilization of aeolian sand, concrete was prepared by replacing river sand with Taklamakan Desert aeolian sand at different mass ratios. The effects of replacement ratio and curing age on compressive strength and microstructure were investigated using compressive strength tests, SEM, and EDS. A quadratic regression model was established by response surface methodology using replacement ratio, curing age, and Ca/Si ratio as variables. The results showed that compressive strength first increased and then decreased with increasing aeolian sand content, with the 20% replacement group achieving the highest strength. Strength increased with curing age, but the growth rate slowed after 28 days. SEM and EDS results indicated that suitable aeolian sand content promoted hydration product formation and matrix densification, whereas excessive replacement increased pores and interfacial defects. The Ca/Si ratio generally increased with curing age. The model showed good fitting accuracy, with R² = 0.9970, providing a reference for strength prediction and mix design optimization of aeolian sand concrete. Keywords: aeolian sand concrete; compressive strength; microstructure; Ca/Si ratio; response surface methodology

Abstract: The current work uses Iterated Fission Probability (IFP) routine that was recently implemented in OpenMC to calculate reactor kinetics parameters. IFP is calculated from the product of the multiplication factors tracked across the L+1 generations of fission progenies. Since IFP is an excellent estimator of adjoint flux, it is able to calculate Λ_eff , β_eff and β_i of the reactor. OpenMC calculation of the reactor itself has k_eff = 1.01687 with an effective mean neutron generation time, Λ_eff = 44.82 μs. The effective delayed neutron fraction, β_eff that we get is 0.007235 or 723.5 pcm. Other calculations of β_eff using prompt methods for reactors with similar designs gave us values between 724 pcm to 752 pcm. Our own calculations using the prompt method in OpenMC gave us an effective delayed neutron fraction of 734.1 pcm. The group β_i that we obtain is 24 pcm, 131.4 pcm,124.1 pcm, 284.0 pcm, 112.7 pcm and 47.4 pcm respectively. If we strip away the influences of β_eff on β_i , by looking at only the abundances of each delayed neutron group, a_i ; we are able to see that the a_i is similar to the abundances of just ²³⁵U in the six group abundances of ENDF/B-VIII.0 evaluated cross section library. When we adopt a different evaluated cross section library in OpenMC, changes in β_i is due to the different β_eff and λ_i adopted in these libraries.

Abstract: This paper presents the complete design and development of a dried whole blood cartridge designed for point-of-care (POC) clinical diagnostics. The system integrates a near-infrared (NIR) spectroscopy sensor with a disposable multilayer paper cartridge capable of collecting and analyzing small, controlled volumes of capillary blood (20 μL). The work emphasizes a technical and iterative design approach that combines product design with both additive and subtractive prototyping, supported by experimental validation. The development process involved multiple design iterations focusing on fluid transport, capillary dynamics, usability, and optical integration. Several materials and manufacturing processes, such as CNC (Computer Numerical Control) machining and Material Jetting (MJ), were explored to optimize channel geometry and flow behavior. Experimental results guided successive refinements, leading to a cartridge configuration that ensures efficient capillary action, minimal coagulation, and consistent optical alignment with the sensor’s analysis zone. The study underscores the importance of an integrated engineering approach that unites design methodology, material selection, and manufacturing processes to achieve a reliable and reproducible cartridge for point-of-care blood diagnostics. It demonstrates how iterative design, supported by experimenal testing, can effectively bridge the gap between experimental prototyping and practical implementation in medical device development.