In recent years, geotechnical engineering has experienced a surge of interest in sustainable and environmentally responsible soil improvement technologies. Out of these, bio-cementation using calcium phosphate compounds (hereinafter referred to as CPCs) has emerged as a promising and novel approach for soil stabilization. Unlike conventional methods that may contribute to environmental concerns, CPC-based bio-cementation offers multiple benefits, including environmental compatibility, non-toxicity, self-setting behavior, and the potential for material recycling. Moreover, the application of CPCs mitigates the issue of ammonium pollution commonly associated with ureolytic pathways, positioning this technique as a more sustainable alternative. However, there are unexplored sites of this technology that remain to be found out. It is essential to evaluate whether the multifaceted CPC bio-cement can feasibly provide a robust skeletal framework for soils, while aligning with greener concepts, akin to the structural role that bones play in humans and animals. Originally developed for biomedical applications, CPCs were first introduced to geotechnical engineering in 2010, yet their full potential remains underexplored. This review holistically examines the technical performance, economic feasibility, and environmental sustainability of CPCs as soil binders. Through a comprehensive analysis of current research and application trends, this study aims to establish a foundational understanding of CPC-based bio-cementation and assess its viability as a green binder for future geotechnical applications. The review concludes with strategic recommendations to guide future researchers and foster the industrial advancement of CPC in the field of geotechnical engineering.
This study investigates the application of machine learning (ML) for predicting the compressive strength of cement mortar, which is influenced by a combination of mix design parameters, sand characteristics, and curing time. A comprehensive dataset was utilised, incorporating factors such as the aggregate-to-binder ratio, water-to-binder ratio, detailed sand properties (including fine content, sand content, mean particle size, uniformity coefficient, and others), and curing time. The study applied several ML algorithms, including linear regression, artificial neural networks (ANN), K-nearest neighbors (KNN), random forest regression (RFR), support vector regression (SVR), and extreme gradient boosting (XGB). The models were trained using a 70:30 train-test split and evaluated through 10-fold cross-validation, with performance metrics including R², root mean square error (RMSE), and mean absolute error (MAE). The results revealed that XGB performed the best, achieving a testing R² of 0.94 and an RMSE of 3.75 MPa. This was followed by ANN with a testing R² of 0.93 and RMSE of 3.96 MPa, and SVR with an R² of 0.92 and RMSE of 4.04 MPa. Sensitivity analysis indicated that the aggregate-to-binder ratio (Agg/B), water-to-binder ratio (W/B), and curing time were the most critical factors affecting compressive strength. Although less influential, sand properties still contributed significantly, particularly in terms of aggregate packing and paste demand. The findings suggest that ML offers a promising approach to optimising cement mortar mix designs, enhancing quality control, and reducing the need for extensive experimental trials in the construction industry.
In this study, an iodine-free 1-butyl-3-methylimidazolium iodide (BmimI) ionic liquid, modified with acetonitrile (AN), was employed as a redox mediator using a facile approach to enhance DSSC performance. The optical properties of BmimI-AN(1:2) electrolyte (BmimI: AN = 1:2 w/w) indicate low absorption and high transmittance in the visible region. In addition to the UV-Vis spectra, Raman spectra also confirm the presence of the in-situ generated I_3^- ions, which are sufficient to complete the reaction mechanism in DSSCs. Conductivity measurements revealed that the BmimI-AN(1:2) electrolyte possesses excellent ionic conductivity compared to BmimI and standard commercial I^-/I_3^- electrolytes. The photovoltaic performances of the fabricated devices were analysed under simulated irradiation at an intensity of 100 mWcm–2 using a Xe lamp with an AM 1.5 filter. The BmimI-AN(1:2) electrolyte led to a higher power conversion efficiency (PCE) in DSSC, reaching up to 6.26 ± 0.21
In this study, we investigate the optical soliton solutions, stability and sensitivity analysis of the (2+1)-dimensional complex modified Korteweg-de Vries (cmKdV) system of equations. To obtain soliton solutions, we utilized the newly developed extended auxiliary equation method, leading to a range of Jacobi elliptic function solutions. These solutions are further shown to reduce to bright, dark, singular and periodic solitary wave solutions under specific parameter choices. In addition, a linear stability analysis is performed to derive the criterion for modulation instability (MI) associated with the continuous wave solutions of the considered equation. A detailed sensitivity analysis is also conducted under varying initial conditions to express that the equation is extremely sensitive. The physical behavior of the obtained solutions is then visualized through the 3D graphical representations.
Scholarship in the Global North has traditionally treated trauma as an individual pathological condition that needs medical intervention. However, Global South communities such as Sri Lanka approach trauma differently. Since the whole community has lived through centuries of colonization and decades of civil war, trauma is collective. For this reason, the community has developed everyday practices for a supportive environment. Such community-sponsored cultural and relational practices do not pathologize trauma. Survivors are treated as exhibiting forms of neurodiversity that come with their own strengths such as resilience, patience, and dependency. Their communication is not treated as fragmented and incoherent, but as meaningful when others co-construct meanings with them, adopting diversified semiotic resources, and going beyond normative assumptions. English language teachers have adopted pedagogical strategies influenced by such relational orientations. This article will discuss the intuitive strategies Northern Sri Lankan educators and students have adopted since the civil war.
