Thermal–economic design optimization of an instant cooling water dispenser with a vapor compression refrigeration system

Background: Soft soils present significant challenges in civil engineering practice due to their high compressibility, low shear strength, and susceptibility to excessive settlement under structural loading. Accurate characterization and prediction of settlement behavior are therefore essential for safe and economical foundation design, particularly in regions underlain by soft cohesive soils. Methodology: In this study, soil samples were obtained from three locations, with two trial pits per location, at depths of 0.5 m and 1.0 m, using a systematic site investigation approach. Laboratory testing was conducted in accordance with relevant ASTM standards to determine key geotechnical parameters, including moisture content (MC), optimum moisture content (OMC), cohesion (C), internal friction angle (∅), maximum dry density (MDD), unconfined compressive strength (UCS), shear strength (SS), void ratio (e₀), hydraulic conductivity (K), and consolidation characteristics. Principal Component Analysis (PCA) was applied to identify dominant soil parameters controlling behavior, while multivariate linear regression models were developed to predict total settlement, unconfined compressive strength, shear strength, and permeability Results: The results indicate pronounced spatial variability in soil properties across locations and depths, reflecting heterogeneity typical of soft soils. Correlation analysis, regression modeling, and PCA consistently identified moisture content, void ratio, permeability, and compressibility-related parameters as the primary controls on settlement behavior. The regression models exhibited high predictive accuracy, with coefficients of determination (R²) ranging from 97.0% to 99.9%, confirming strong quantitative relationships between soil properties and measured responses. PCA revealed that the first principal components are dominated by void ratio and hydraulic conductivity, representing a compressibility–permeability mechanism, while strength- and density-related parameters govern secondary components, reflecting soil compactness and structural resistance. Conclusion: This study demonstrates that integrating laboratory-based soil characterization with statistical tools provides both predictive and interpretative insights into soft soil behavior. While PCA–regression techniques are established in geotechnical analysis, their application to site-specific soft soils enables a clearer identification of critical parameters influencing settlement. The developed regression models and PCA framework offer practical decision-support tools for foundation design and settlement risk assessment in soft soil environments, while highlighting the need for broader datasets to enhance regional generalization.

Through our research, we found that many existing drone systems do not clearly solve the problems related to thermal detection in disaster areas, and they often fail in providing reliable real-time human detection. These issues are important to address because search and rescue operations need to be more efficient, time-saving, and economic. Since UAVs are extremely useful in locations where humans cannot reach easily, improving their performance in such missions becomes essential for future emergency response systems. In this work, we propose a drone system designed to detect humans more effectively by using audio, video, and thermal inputs. Our approach focuses on integrating GPS, computer vision, and artificial intelligence to automate the drone’s operation and support real-time data processing. The drone captures photos, videos, audio, or thermal images, and the AI model confirms whether a human is present and potentially in need. Once detection is verified, the system immediately processes and sends the information to rescue teams in real time. It can also hold its position or circle around the target until responders arrive. The implications of this system show that faster alerts, improved detection accuracy, and economic design can significantly support rescue teams and help save more lives during emergencies.

Punching Shear failure is a severe Limit condition that controls the seismic behavior of Reinforced Concrete (RC) flat slab-column connections. Such critical structural connections are widely used in modern construction due to economic design benefits and aesthetic appearances, which reduce the floor height in the absence of beams. The study identifies the key parameters that influence flat slab column connection failures, including punching shear, inadequate reinforcement, and poor detailing. Previous studies have revealed that the punching shear failure is the primary cause of Flat slab column connection failures, strongly influenced by concrete grade and reinforcement detailing. This work is a Finite Element Analysis (FEA) exploration of twelve flat slab-column connection models in FEA software to assess the effect of concrete grades M25 and M30, utilizing different types of reinforcement, including stirrups and stud rails, and loading for both static and seismic conditions. Concrete Damaged Plasticity (CDP) was used to model the nonlinear material behaviour of concrete, and the seismic shear demand was applied as required by the IS 1893. Unstiffened flat slabs in the shear region were brittle and exhibited rapid post-peak strength that declined, resulting in low residual capacity. Conversely, a stiffened flat slab in the shear region has demonstrated significant improvements in mass-carrying capacity, ductility, and energy-dispersing capabilities. Stirrups increased confinement, and stud rails offered better stability at the post-peak by maintaining residual strength and increasing the time to evolve damage. A higher concrete grade increased stiffness and maximum resistance, whereas the type of reinforcement was a key factor in determining ductility. A relative comparison with IS 456, ACI 318, and Eurocode 2 design provisions revealed that the predictions of punching shear using these codes are always conservative compared to those obtained through numerical methods. In general, the results emphasize the significance of reinforcement detailing in increasing the seismic resilience of flat slab systems, with stud rails proving to be the most promising form of reinforcement.

Energy efficiency plays a crucial role in the initial design of chemical plants, as it directly influences operational costs and process sustainability. In sodium hydroxide plants, the substantial thermal energy demand, especially in heating and cooling units, necessitates effective energy optimization strategies. This study seeks to enhance energy efficiency in the preliminary design of a sodium hydroxide plant by incorporating heat exchangers (HE) through a Heat Exchanger Network (HEN) approach, utilizing the HINT application based on the Pinch Analysis method. Process stream data, including temperature, mass flow rate, and heat capacity flow rates of hot and cold streams, were analyzed to identify the pinch point, minimum heating and cooling utility requirements, and the optimal heat exchanger network configuration. The findings reveal that adding heat exchangers significantly boosts internal heat recovery and reduces the need for external utilities. Consequently, applying Pinch Analysis with the HINT application at the preliminary design stage of a sodium hydroxide plant effectively enhances energy efficiency, supporting a more economical and sustainable plant design.

Addressing socioeconomic challenges has become a central concern for emerging market economies, where financial instability can rapidly spill over into the real economy and undermine sustainable development. This paper develops novel stress indices for Türkiye’s financial institutions, financial markets, and real economy using three widely applied methodologies: equal variance weighting, principal component analysis, and portfolio theory (CISS). By constructing sector-specific and aggregate indicators, the study provides a comprehensive framework for monitoring financial stress in an emerging market context. The proposed indices are further evaluated using discrete choice models to assess their ability to signal periods of elevated financial vulnerability. This research makes three main contributions. First, it extends the financial stress literature by developing a multi-dimensional stress measurement framework that integrates financial institutions, financial markets, and the real economy for an emerging market economy. Second, it offers a systematic comparison of alternative aggregation methodologies, highlighting their relative strengths for different types of stress episodes. Third, it provides policy-relevant tools that can support macroprudential surveillance and early-warning systems. Overall, the study underscores how tailored stress indicators can contribute to more effective economic policy design and help address socioeconomic challenges arising from financial instability.

Computational modeling offers a cost-effective approach to exploring complex geotechnical behavior. This study uses PLAXIS 2D finite element software to simulate nailed soil slopes under plane strain conditions, with models calibrated against laboratory-scale experiments involving a sand-filled Perspex box, steel nail reinforcements, and a rigid foundation. The soil mass, structural elements, and reinforcements are modeled using fifteen-node triangular elements, five-node plate elements, and two-node elastic spring elements, respectively. In this paper, parametric studies evaluate the influence of slope angles, mesh density, domain dimensions, constitutive models, and reinforcement configurations. Both prototype-scale and 3D-approximated models are included to assess scale effects and spatial behavior. The results highlight the significant impact of model size and material behavior, particularly when using the Hardening Soil model and its small-strain extension. Reinforcement optimization, including nail length reduction strategies, demonstrates the potential for maintaining slope stability while improving material efficiency. Validation against experimental data confirms that the numerical models accurately capture deformation patterns and internal stress development across different construction and loading phases. This study observed that the Hardening Soil (small-strain) material model significantly improved slope performance by reducing settlements and better capturing stress behavior, especially for steep slopes. Optimized redistribution of nail lengths across the slope depth enhanced stability while reducing reinforcement usage, demonstrating a cost-effective alternative to uniform configurations. The findings offer practical guidance for optimizing nailed slope stabilization in sandy soils, supporting safer and more economical geotechnical design for real-world applications.

Abstract-This project analyzes soil–structure interaction (SSI) of strip footings using PLAXIS 2D. Various soil types—soft clay, stiff clay, sandy clay, sand, and dense sand—are modeled to study their effects on bearing capacity and load–settlement behavior under central and eccentric loading. Results show dense sand provides the highest capacity with minimal settlement, while soft clay performs the weakest. Comparisons with Terzaghi, Brinch Hansen, Meyerhof, and IS Code methods show close agreement, with PLAXIS giving slightly conservative values. Eccentric loading (e/B = 0.2) reduces bearing capacity by up to 30%, emphasizing its importance in design. The study demonstrates the usefulness of PLAXIS 2D in realistic geotechnical analysis. Additionally, the modeling highlights the nonlinear response of soils under increasing stress. Interface elements capture slip and separation at the footing–soil boundary effectively. The study also shows that settlement patterns change significantly with soil stiffness. Numerical stress contours help visualize failure mechanisms clearly. Overall, the findings support using advanced FEM tools for accurate, safe, and economical foundation design. Index Terms-T-Beam; IRC-codes; Bourbon’s method; Deflection; Crack Soil–Structure Interaction, PLAXIS 2D, Strip Footing, Bearing Capacity, Load–Settlement, Eccentric Loading, Soil Types. width etc.

This study presents a novel approach for interpreting static load tests (SLT) of piles using Artificial Neural Networks (ANNs) integrated with the Meyer and Kowalow load-settlement mathematical model. Reliable estimation of pile bearing capacity and settlement behavior is critical for safe and economical geotechnical design, particularly given the nonlinear and heterogeneous nature of soils. Traditional SLT interpretation methods, such as Chin-Kondner, Decourt, and hyperbolic fitting approaches, provide useful extrapolation of the ultimate capacity but are sensitive to test termination levels and parameter estimation uncertainties. The Meyer and Kowalow function offers a robust mathematical representation of the load-settlement curve, allowing decomposition of the total pile resistance into the shaft and base components. In this work, ANN models were trained to solve both the direct and inverse forms of the Meyer and Kowalow problem, enabling rapid identification of constitutive parameters (initial stiffness, nonlinearity coefficient, and ultimate capacity) from measured SLT data. Numerical experiments demonstrated that networks with a single hidden layer achieved accurate predictions with low RMSE for both training and test sets. The proposed ANN-based framework facilitates improved parameter identification, supports partial-load SLT interpretation, and provides a practical tool for engineers seeking the reliable prediction of pile performance under service loads.

Abstract - The present work deals with the structural design and analysis of an Intze-type overhead water tank, which is one of the most commonly used systems for dependable water storage and distribution both in urban and rural areas. The configuration of the Intze tank, consisting of a top dome, cylindrical wall, conical dome, and a bottom ring girder, represents an extremely efficient structural form that reduces material consumption while maximizing strength and stability. An optimal determination of dimensions, reinforcement details, and supporting components has to be derived to resist safely the water load, self-weight, wind forces, and seismic effects within the stipulation of applicable design standards. A comprehensive structural analysis is performed to check all stresses, bending moments, and axial forces arising on each component of the tank. Great care has been taken to ensure durability, serviceability, and economy by selecting appropriate materials and reinforcement. The staging system design forms part of the project, which supports the tank at the desired height to give proper distribution pressure. In general, the aim is to provide a safe, economical, and strong overhead tank design with ample community water supply requirements and adhering to the latest engineering practices and provisions. Key words: Limit state method(LSM), modeling with the help of STAAD PRO, total station.

This paper presents the development of serviceability-based design charts for partially prestressed high-strength concrete (HSC) girders, with a focus on cracking and deflection performance. Partially prestressed girders, which serve as an intermediate design between fully prestressed and conventionally reinforced concrete, offer both structural efficiency and economic benefits. However, there is a notable gap in research regarding specific serviceability guidelines, particularly for controlling cracking and deflection in these girders. To address this gap, this study utilizes validated finite element models to investigate key variables, including the concrete compressive strength, prestressing forces, and non-prestressed reinforcement ratios. Parametric investigation provides insights into the impact of these factors on girder behavior under service loads, leading to the development of practical design charts. These charts allow for quick estimation of the optimal prestressing and reinforcement ratios that meet predefined serviceability limits, simplifying the design process for engineers. The proposed charts offer an accessible, efficient tool for optimizing material usage while ensuring compliance with serviceability criteria, making them highly valuable for the design of HSC girders in bridges and other infrastructures. Ultimately, this research enhances the usability of partially prestressed HSC girders, promoting more effective and economical designs in structural engineering practice.

Abstract This study examines the VVIP Airport Access Road Construction Project in Penajam Paser Utara Regency, with the objective of comparing pavement design methods and assessing their structural adequacy, cost efficiency, and sensitivity to soil conditions. Flexible pavement designs were developed using the Pavement Design Manual (MDP 2017), AASHTO 1993, and the Component Analysis Method (MAK), while rigid pavement was designed using the Cement Concrete Pavement Guidelines (Pd T-14-2003). Structural analysis was performed using Kenpave software, and cost estimates were calculated based on regional government regulations. Results show that the MAK method produces the thickest pavement, while AASHTO 1993 yields the most economical design. Rigid pavement designed under Pd T-14-2003 demonstrates structural reliability but incurs the highest cost. Soil characteristics significantly influence both thickness and cost, with weaker soils requiring thicker and more expensive designs. These findings provide practical insights for optimizing pavement planning in large-scale infrastructure projects.

Advanced seismic resilience assessment of self-centering frames with slotted infill walls: Economic losses and design implications

Abstract In conventional cold‐formed steel (CFS) structural design, floor‐to‐wall joints are generally considered pinned and, thus, incapable of transferring moments. However, recent studies have shown that the use of semi‐rigid connections can lead to more efficient and economical frame designs. This paper presents an experimental investigation into CFS frames with semi‐rigid joints, comprising a series of full‐scale tests on CFS frames with varying joint stiffnesses, varying joist and stud dimensions and different screw arrangements between the steel joists and timber boarding. Digital image correlation (DIC) was employed to monitor rotations and the buckling behaviour of the joists in detail. The joint rotational stiffness was found to have a significant influence on the limit states of the CFS frames, while it was shown that optimised combinations of joist and stud dimensions, along with appropriate screw arrangements, can further enhance structural efficiency.

Reliability-based optimization of economic life forward design for complex systems in uncertain task environments

Operational and economic design of multi-terminal medium DC voltage hybrid renewable energy systems for effective power sharing

The analysis of policy impacts in a dynamic and uncertain reality is vital to supporting informed economic policy design and implementation. Dynamic, stochastic economic models used in policy evaluation necessarily simplify the world as we know it. This motivates us to explore, refine, and extend tools aimed at producing marginal valuations that shed light on why some policies are optimal and how others, though suboptimal, can be improved. We present representations of these marginal valuations that embrace uncertainty and support robust implementation-even in environments characterized by "deep uncertainties." These representations offer a more complete understanding of how interactions among multiple state variables, concerns about model misspecification, and uncertainties surrounding potentially long-term implications contribute to the cogent assessment of policies. We argue that these methods are particularly salient for evaluating the global cost of climate change and the global value of research and development with long-term prospects for success.

This letter presents a high-gain frequency-controlled beam-scanning antenna specifically designed for through-wall radar (TWR) applications in the W band. The antenna leverages the leaky-wave radiation generated by spoof surface plasmon polaritons (SSPPs) propagating on sinusoidally modulated reactance surfaces (SMRS). Periodically arranged quasi-H-shaped metallic cells are employed to achieve beam scanning. The integration of a flared structure at the apex of the designed SSPP antenna results in a significant gain enhancement, yielding an approximate increase of 10 dB. From 92.8 to 97.6 GHz, the antenna exhibits a reflection coefficient of |S11| < −10 dB, provides a high scanning rate of 4.05°/%, and achieves a realized gain of 20.9 dBi. This design eliminates the necessity for mechanical rotators and phase shifters that are typical in traditional TWR systems, significantly reducing system complexity and cost. A vehicle-mounted W-band TWR system was developed, integrating the designed SSPP antenna and employing linear frequency modulation technology to emit millimeter-wave signals for electronic scanning detection. With an economical and efficient design approach, testing has demonstrated that the system can perform through-wall imaging at a distance of 10 m, both in stationary and in motion conditions.

This paper focuses on a deep foundation pit project of a metro shaft constructed by the cover-and-excavation reverse method in a section of Guangzhou Metro Line 13. This study integrates field monitoring data, three-dimensional finite element simulations, and parametric analyses to propose a systematic optimization design framework, providing a more comprehensive and reliable quantitative basis for the design of support structures for deep metro foundation pits constructed using the cut-and-cover top-down method. The study examines the effects of pile diameter, pile spacing, embedment depth, and types of retaining structures on pit deformation. The results indicate that increasing the pile diameter from 800 mm to 1000 mm reduces the maximum lateral displacement of the retaining structure by 30.7%, while decreasing the pile spacing from 2000 mm to 1600 mm results in a 17.5% reduction in deformation. However, beyond these thresholds, the marginal improvement becomes less significant. An embedment depth of 4 m for shallow sections and 2.5 m for deep sections is recommended to balance deformation control and construction economy. Diaphragm walls outperform bored piles and secant piles in deformation control. The optimized design achieves an estimated cost reduction of approximately 15% while maintaining safety requirements. The optimized parameters and comparative conclusions derived from this study can be directly applied to the design of deep foundation pits for metro stations under similar geological conditions. These findings provide crucial data support and theoretical reference for formulating more economical and safer design codes and standards.

ABSTRACT Objective of this paper is to study how reliability standards, expressed as probabilities of dike segment failure, can be practically updated to improve opportunities for risk‐based dike design and planning. The approach to assess the economic optimal flood probability, used by the Dutch Delta Committee (1958, in this paper referred to as Van Dantzig), is adapted to reflect time‐dependent effects of a.o. climate change and subsidence. Furthermore, the approach is adapted to reflect overtopping instead of overflow and it is extended to include reinforcements over time. A comparison of the results of the Adapted Van Dantzig approach with the economic optimal probabilities used as input for the recently formalised Dutch standards (2017) is performed for 73 dike segments in the Netherlands, showing good agreement. Following the Adapted Van Dantzig approach, an analytical relation is developed for economic optimal design horizons, dependent on the dike design, and characteristics of load, investment, climate effect, and economic growth. Finally, a dynamic and simple‐to‐use approach is developed to enable updating of the economic optimal reliability based on a proposed design and investment planning. This can serve to consider whether an existing reliability standard still fits adequately or needs updating.