Advanced surface modification of CoCr alloys for biomedical Applications: The impact of TiB2 and BN coatings on wear, hardness, and radiation shielding

This research looks into how Boron Nitride (BN) and Titanium Diboride (TiB2) coatings change the surface properties of biomedical CoCr alloys made with selective laser melting (SLM) technology. SEM analyses confirmed uniform coating thicknesses compatible with theoretical calculations. Radiation attenuation tests demonstrated increased linear attenuation coefficients (LAC) and mass attenuation coefficients (MAC) at 1.173 MeV for both coatings, with TiB2 providing superior performance. Mechanical tests revealed significant improvements in hardness, with TiB2 and BN increasing it by 16.2 % and 15.9 %, respectively. Wear tests showed that BN coatings reduced friction coefficients, while TiB2 increased wear resistance. HVL, TVL, and MFP parameters showed improved gamma shielding at 1.173 MeV, though less effectiveness at 1.332 MeV. These results indicate that BN and TiB2 coatings enhance the mechanical, wear, and radiation attenuation properties of CoCr alloys, making them suitable for long-lasting biomedical implants

New fluorescent coumarin dyes containing functional acceptor groups: The investigation of photophysical, optical, and thermal properties

Nine novel coumarin-based compounds with a donor-π-acceptor system were synthesized, and their structural characterizations were determined by spectroscopic methods. The effects of different acceptor groups, such as dicyanovinyl, cyanoacrylic acid, and rhodanine-3-acetic acid at the 3-position of the coumarin ring, on the electronic and optical properties of the structure were investigated. Moreover, the coumarin structure was derived by adding an electron donor methoxy group, and a fused benzene ring, which also increases the planar structure. Synthesized compounds' absorption and emission properties are strongly influenced by substitution in the coumarin moiety. Four dyes showed near-IR emission in the solid state with green to orange fluorescence under UV light. The structural and electronic properties of the molecules were obtained with the DFT calculations at B3LYP/6-311++g(d,p) level of theory. The frontier molecular orbitals and the global reactivity descriptors were computed. Additionally, some DSSC parameters for 3a-c and 5a-c were also determined to provide insight into their potential. All compounds showed good thermal stability (Td > 200 °C)

Copper tailings recycling in cement-based composites: A deterministic LCA approach accompanied by microstructure, mechanical, thermal and non-destructive tests

Innovative approaches to sustainable building materials are needed due to the cement industry's high carbon footprint and the environmental management of massive amounts of copper tailings (CT) from mining operations. Using a comprehensive approach, this study aims to evaluate the thermal-mechanical performance and ecological sustainability of CT, a high-silica (>79 %) and distinctly bimodal grain-distribution material from Artvin-Murgul, as a pozzolanic additive in cement-based composites. To achieve this, mortar series were created in which CT was added to cement at weight percentages ranging from 0 % to 15 %. Mechanical, thermal, microstructural, and pozzolanic activity analyses were employed to evaluate the performance of the samples. A cradle-to-grave Life Cycle Assessment (LCA) employing the EF 3.1 method in compliance with ISO 14040/44 standards was also used to evaluate environmental performance. With a pozzolanic activity index of 76.2 %, the results verified that CT is a pozzolanic material. The 28-day compressive strength was maintained at 52.5 MPa, with the best performance from the 5 % CT replacement. The composite's higher density, however, resulted in a slightly lower specific strength compared to the control sample, underscoring the trade-off between mass efficiency and environmental advantages. Additionally, there was a 2.1 % increase in flexural strength (7.17 MPa). The success of the pozzolanic reaction has been chemically verified through microstructural analyses. The weak Ca(OH)2 phase was consumed by the 5 % CT addition, which significantly decreased the Ca/Si ratio in the matrix and resulted in a more robust C-S-H structure. According to LCA results, applying 15 % CT resulted in notable improvements in Global Warming Potential (GWP) and all impact categories, particularly acidification and eutrophication. A 12.4 % decrease in net lifecycle GWP was computed, taking carbonation effects into account. In addition to enhancing mechanical performance, this study demonstrates that using CT at the optimal rate offers substantial environmental advantages, as evidenced by LCA. This process effectively turns industrial waste into a valuable, eco-friendly building material

Effects of the thermal-structural optimization and fin-assisted cooling on the heat dissipation performance of a prismatic lithium iron phosphate battery pack for photovoltaic energy storage

The effective temperature management for prismatic lithium iron phosphate (LiFePO₄) battery packs in photovoltaic (PV)-based Battery Energy Storage Systems (BESS) is essential for battery performance, lifespan, and safety. In this paper, the thermal-structural optimization on the heat dissipation performance of a prismatic LiFePO₄ battery pack for photovoltaic energy storage with Grey Relation Analysis (GRA) was investigated. The Taguchi experimental design was performed as L9&nbsp;orthogonal array to analyze the effects of inter-cell spacing (x and y), discharge rate (C-rate), and air velocity on the thermal (cooling) performance by numerical simulation using ANSYS Fluent on the thermal-structural optimization. The optimal structural configuration has identified as inter-cell spacing of x&nbsp;=&nbsp;20&nbsp;mm (A2), y&nbsp;=&nbsp;10&nbsp;mm (B1), C-rate of 0.7C-rate (C1) and air velocity of 4&nbsp;m/s (D3). The maximum temperature (Tₘₐₓ), temperature difference (ΔT), compact module volume and the highest thermal-hydraulic performance ratio without fin of the optimum configurations were determined as 308&nbsp;K, 0.672&nbsp;K, 22,153&nbsp;cm3&nbsp;and 0.49, respectively, corresponding to an 11&nbsp;K reduction in average temperature and a 3.4&nbsp;% thermal efficiency improvement with A2B1C1D3. ANOVA identified the C-rate as the leading factor with 81.12&nbsp;% contribution ratio followed by air velocity (v) with 7.59&nbsp;%. Subsequently, the effects of cylindrical, conical, and prismatic fin-assisted cooling were investigated on the selected optimal structural design. The temperatures on the cylindrical, conical and prismatic fin-assisted cooling have computed as 304.8&nbsp;K, 305.3&nbsp;K and 305.6&nbsp;K, respectively. The structural without fin exhibits the lowest pressure drop (231&nbsp;Pa) whereas the conical, prismatic and cylindrical fins have 865&nbsp;Pa, 811&nbsp;Pa and 578&nbsp;Pa pressure drops. The best thermal-hydraulic performance ratio (Φ) was calculated as 0.52 for the cylindrical fin-assisted cooling, which represents an improvement of 6&nbsp;% compared to the finless structure. The regression equations were developed for lowest and highest temperature (Tmax, Tmin) and the thermal–hydraulic performance ratio (Φ) and the R2&nbsp;values have calculated high predictive accuracy as 0.998, 0.999 and 0.980, respectively. As a result, this work will provide a significant reference and valuable guidance for designing improved fin-assisted cooling on a prismatic LiFePO₄ battery module in PV-based BESS applications.</p

Peroxidase mimetic BSA-stabilized Pt nanozyme for colorimetric determination of arsenic

Arsenic is a highly toxic metal with harmful properties for the environment, humans, and other living things. Nanomaterials that exhibit enzyme-like catalytic activity are called nanozymes. In this study, BSA-stabilized Pt nanozymes were synthesized and characterized using TEM, XPS, and Uv-vis spectroscopic methods. A peroxidase mimetic nanozymes were used for the determination of arsenic in water, urine, and serum samples based on nanoparticle-catalyzed oxidation of colorless tetramethylbenzidine (TMB) to blue oxTMB in the presence of H2O2. Arsenic selectively inhibited this oxidation process, causing a decrease in UV–Vis absorbance at 652 nm and solution discoloration. The average diameter of Pt nanoparticles was measured as 1–2 nm and possesses highly peroxidase-like activity with the Km values of 0.17 mM and 104 mM towards TMB and H2O2, respectively. Under optimized conditions, arsenic was detected with a detection limit of 0.75 nM with a linear response range of 10–100 nM, which means the developed system is sensitive enough to detect As in drinking water, which has the maximum allowable limits of 10 μg/L (133 nM) defined by the World Health Organization (WHO) and the EPA. Recovery values were obtained 99 %–100.4 %–105.6 % for water, urine, and serum samples, respectively. AGREE calculator assessment (0.72), BAGI (72.5), and RAPI (90.0) confirmed the method's greenness, practical applicability, and offering advantages of minimal organic solvent consumption compared to existing techniques

Photophysical properties and color-tunability of diaryl ether-bridged pyrrolo[3,2-b]pyrrole (TAPP) derivatives

Diaryl ether-bridged pyrrolo[3,2-b]pyrrole (DHPP) derivatives were synthesized, and their photophysical properties were systematically investigated in both solution and solid states. UV–vis spectroscopy in toluene, THF, and DMSO revealed characteristic π→π∗ absorption bands around 350–360 nm for all compounds, showing minimal solvent dependence. Fluorescence measurements indicated emissions around 430 nm in nonpolar and moderately polar solvents (toluene, THF), whereas highly polar DMSO induced pronounced bathochromic shifts (470–500 nm) for ortho-chlorinated derivatives (2-Cl (6), 2,4-diCl (10), and 2,5-diCl (11)). These shifts are attributed to enhanced stabilization of the intramolecular charge transfer (ICT) state due to increased excited-state dipole moments and specific solvation effects in DMSO. Solid-state photoluminescence (PL) studies showed ∼25 nm red shifts for the same derivatives, while other derivatives-maintained emissions near 450 nm, highlighting the effect of substituent position on excited-state conformation and electron density. CIE color coordinate analysis confirmed solvent- and substituent-dependent emission tunability, indicating potential applications as solid-state, color-tunable luminescent materials. Overall, the results demonstrate the crucial role of the diaryl ether bridge in modulating electronic communication and controlling aggregation-induced quenching, as well as the impact of substituent positioning on fine-tuning photophysical properties for advanced optoelectronic applications