Bio-nanomaterials are gaining increasing attention due to their renewable and eco-friendly characteristics. Among these, nanocrystalline cellulose (NCC) stands out as one of the most advanced materials for applications in food, healthcare, composite production, and beyond. In this study, NCC was successfully extracted from cotton-based textile waste using a combination of chemical and mechanical methods. The cellulose fibers were first hydrolyzed using a dilute HCl solution, neutralized, and then dried, resulting in microcrystalline cellulose (MCC) with diameters ranging from 7 to 15 µm and lengths up to 300 µm (as observed via optical microscopy and scanning electron microscopy, SEM). To achieve nanoscale dimensions, NaOH/urea solution with mechanical treatment was applied, resulting in the successful extraction of NCC in the supernatant, particularly under room-temperature conditions. Dynamic light scattering (DLS) analysis confirmed the presence of nanostructures (average sizes ranging from 120 nm to 750 nm), and atomic force microscopy (AFM) analysis verified the nanoscale range (diameters between 2 and 4 nm and lengths from 200 nm to 1 µm). Fourier transform infrared (FTIR) spectroscopy revealed the conversion of cellulose I to cellulose II, confirming the successful transformation into NCC. For the first time, NCC was obtained from undyed cotton textile wastes using NaOH/urea treatment after HCl hydrolysis, eliminating the need for pre-treatment and intermediate steps.

This study investigated the mechanical properties of aluminum matrix functionally graded material (FGM) reinforced by integration of aluminum 2014 alloy (AlCu4SiMg) and 15 vol% SiC. The specimens were obtained by centrifugal casting technique, followed by aging treatment. The variations that occurred in microstructure, hardness, Young’s modulus, tensile strength, yield strength, elongation, fatigue, and fretting fatigue behaviors were analyzed. In both cast and aged conditions, it was observed that hardness values and mechanical properties changed between SiC-rich and aluminum-rich regions. Fatigue and fretting fatigue data were similar. It was determined that greater wear was occurring on the pad surfaces compared to that occurring on the sample surfaces.

In this investigation, two distinct composites were produced using the liquid metallurgy vortex-route method with an aluminum AA6013 matrix and 0.5% and 1% nano-Al₂O₃ reinforcement by weight. The effects of nano-Al₂O₃ ceramic particles added into the AA6013 alloy to increase the hardness and strength of the composite were investigated. Samples for welding were prepared from cast composite materials with dimensions of 250 × 110 × 60 mm. The obtained specimens were joined via butt welding at 110-A and 120-A current intensities, and at a constant speed of 400 mm/min by cold metal transfer (CMT) and pulse multi-control (PMC) welding methods. Using the use of micro- and macrostructural evaluations, hardness measurements, and tensile testing, the impacts of each welding parameter on the mechanical characteristics and weld structure of the cast composites were examined. The composite material with 0.5% nano-Al₂O₃ reinforcement that was joined at 120 A utilizing the CMT process achieved the highest tensile strength value at 96.6 MPa. At 110-A and 120-A welding current values, 0.5% reinforced composite demonstrated the maximum strength in both welding techniques.

This study presents a low-cost and environmentally friendly medium for the pack boriding (boronizing) of a Ti6Al4V alloy. Titanium and its alloys are known to be highly reactive and to have extreme oxygen affinity. Therefore, boriding is performed under vacuum or in protective atmospheric conditions. This work evaluated the pack boriding heat treatments of a Ti6Al4V alloy under atmospheric conditions via the various boriding media used by previous researchers. In addition, a new pack boriding medium was developed by adding aluminum. Consequently, this study demonstrated that it is possible to obtain an undamaged titanium surface by applying solid-state boriding under atmospheric conditions.

This study investigates the adsorption performance of activated carbon (AC) derived from food and agricultural waste, specifically coffee grounds, coffee skin, bamboo, and palm leaves, for the removal of two antibiotics: amoxicillin (AMX) and sulfamethoxazole (SMX). The ACs were synthesized via KOH and ZnCl₂ chemical activation and characterized through BET surface area analysis, thermal stability, electrical conductivity, SEM, EDS, and FTIR. Among all samples, bamboo-derived AC (B-AC) exhibited superior properties, such as the highest surface area (860 m²/g), thermal stability (855 °C), conductivity (0.063 S/cm), and adsorption capacities (292.6 mg/g for AMX and 195.7 mg/g for SMX). SEM and EDS analyses confirmed successful antibiotic adsorption with morphological and elemental changes, while FTIR spectra indicated interaction with surface functional groups. Adsorption data were best described by the Langmuir and Dubinin–Radushkevich isotherm models, suggesting a monolayer physical adsorption process dominated by micropore filling (E < 8 kJ/mol). In contrast, BET and Flory–Huggins models exhibited poor fit, confirming the absence of multilayer or partition-based adsorption mechanisms. Kinetic modeling showed that AMX followed a pseudo-second-order model, while SMX exhibited a more complex adsorption behavior. Thermodynamic studies confirmed that both processes were spontaneous, with AMX adsorption being endothermic and entropy-driven and SMX being exothermic but favorable. These findings demonstrate the high potential of B-AC as a low-cost, eco-friendly, and efficient adsorbent for pharmaceutical removal from water, supporting circular economy and sustainability goals.

The article brings to attention a cross cultural model related to the perception of students in relation to the current problem of plastic waste. To create the model, a questionnaire was applied online in two countries at the same time, among students from different specializations. The survey was structured in several parts, with the first part meant to identify individual characteristics of the responders, the second part to identify their knowledge about plastic, determine their beliefs in the new material—bioplastic, their preference in using plastic or bioplastic, and the last part meant to determine students’ attitude towards the environment. The model wants to highlight the preferences and knowledge of students about plastic, the degree of information and students’ knowledge about plastic waste, and if these are influenced by culture; in our case, the country was considered. Also, we established that gender or specialization have no influence on the perception of bioplastic. A total of 39.79% of the students from both countries participate in and attend conferences about nature protection and plastic waste, and only 58.69% of the students do not participate in any conferences about nature conservation or recycling materials. As a conclusion, we can mention that Turkish students are more responsible and more active in environmental activities regarding plastic waste in comparison with Romanian students. In comparison with Romanian students, Turkish students are more careful when it comes to recycling waste plastic and when choosing products that are less harmful to nature. The young generation is open to selective recycling, even if they sometimes do not follow the established rules. Based on this model, common problems can be identified and universities, as incubators of ideas, can welcome the use of the necessary methods and tools to stimulate care and students’ awareness of the environment and its protection.