In this work, we developed Metal-organic frameworks (MOFs) of different forms by changing metal and organic precursors, characterized them, and used them against methyl green (MG). The C/C-0 indicator for MG was determined to be 0.62, 0.86, and 0.01 for MIL-101, HKUST-1, and ZIF-67-SO4, respectively. A polynomial model developed and validated by statistical indices, i.e. LOF p-value of 0.41, R-Adj(2) > 0.9, R-Predict(2) > 0.8, and [R-Adj(2)- R-Predict(2)] < 0.2, to predicts MG removal as a function of pH, mixing time and adsorbent dose. Accordingly, the optimal operational condition for up to 97% removal achieved at pH 7.1, mixing time of similar to 45 min, and MOF dosage 0.5 g/L. The isotherm model revealed multilayer adsorption of MG, with a qmax of 859 mg/g ZIF-67-SO4. The kinetic study revealed that the initial phase of MG uptake was mostly dominated by passive interaction forces such as van der Waals forces or electrostatic attraction. The presence of co-current species in the real sample showed a 5-7% reduction in the dye removal. In addition, a 14.1% loss in dye removal was observed after the material was reused for the third cycle. The thermodynamic study indicated a spontaneous and endothermic physical adsorption of the dye by ZIF-67-SO4.
Homogeneous and heterogeneous photocatalysis systems were used to treat water contaminated with three pesticides, atrazine (ATZ), diazinon (DIZ), and alachlor (ALC). A pilot-scale plant powered by solar energy, consisting of compound parabolic collectors (CPCs), was used. The effect of H2O2 concentration from 200 to 2400 mg/L, Fe+2 from 5 to 30 mg/L, and TiO2 from 100 to 500 mg/L was studied to find their effects on the degradation efficiency. The concentrations of the parent pollutants rapidly declined to zero for ALC and DIZ in the initial stages of the experiment and were converted into intermediate products. The chemical oxygen demand (COD) removal efficiency for the homogeneous photocatalytic process at the optimal dosage was 45%, 74%, and 80%for ATZ, ALC, and DIZ, respectively. In comparison, the heterogeneous photocatalytic system showed removal efficiencies of 43%, 73%, and 76% for the same compounds. The single, binary, and ternary pesticide mixtures were tested in a homogeneous system. The results show that ATZ reduces oxidation of the mixture when combined with other pesticides. An artificial neural network was employed to predict the experimental results. The model demonstrated a good fit with the experimental results.
Poly(methyl methacrylate) (PMMA) is a synthetic polymer that is extensively utilized in a wide variety of industries for medical devices and electronics, such as OLEDs and solar cells. In spite of its wide range of applications, the stability of the polymer under UV exposure remains a significant issue that negatively affects its performance, especially in an outdoor environment. Recent studies revealed that PMMA suffers from significant loss of mechanical properties after UV light exposure because of chain scission and bond breaking. To address this issue, pure PMMA is blended with PMMA modified using 1,4-phenylenediamine and one of the following photostabilizers: 2-nitrobenzaldehyde, 4-nitrobenzaldehyde, or 3,4-dimethoxybenzaldehyde. The modified polymers were identified using FTIR, 1H NMR, and energy-dispersive X-ray (EDX) spectroscopies. Further, the influence of UV light on pure PMMA and the blends was assessed using various approaches, including functional group indices, the percentage of weight loss, and the leaching/extraction test. The made films were also characterized before and after irradiation by SEM and AFM images. Results show that the blends have superior photostability compared to pure PMMA, especially the blend containing 3,4-dimethoxybenzaldehyde. This blend has the lowest values of functional group indices and weight loss, as well as a smooth surface according to the SEM image after 300 h of irradiation.
Objectives: Background Non-Melanoma Skin Cancers (NMSC) are the most common malignant tumors of the skin and are often located in cosmetically and functionally important regions such as the face. Complete elimination of the tumour with an acceptable aesthetic result and without impairing functions including speech and oral competence, continues to be a major surgical challenge. Gold standard for margin control remains Mohs micrographic surgery, but its availability is restricted in many areas. FSE-assisted resection provides a feasible intraoperative option that allows such patients to be approached in one operating session with structural balance between oncological safety and reconstruction. The outcomes: Thirty patients with histologically proven NMSC received excision under frozen section, followed by adequate reconstruction in this prospective study. The average age was 54.9 years (range, 17-81) and there were more females 18(60%). Two-thirds of cases 20(66.7%) were BCC and one-third 10(33.3%) were SCC. The cheek, the scalp and the nose were most frequently involved 6(20% each). Forty percent of the patients were closed primarily, 20% underwent skin grafting and 40% received flap coverage. Flap techniques were more commonly associated with injuries to the nasal area and lips than minimally, from an aesthetic aspect as well as functional preservation, important regions (p = 0.003). On multivariate logistic regression, tumour size larger than 2 cm was the only independent predictor for flap reconstruction (OR = 24.9; CI: 1.48-420.2; p = 0.026). Conclusion: These results substantiate that frozen section- guided excision is a safe and accurate method for NMSC in cosmetically sensitive regions, when Mohs surgery is not available. Tumour size is still the main factor which determines the reconstructive difficulty and large multicentric studies with long-term results are needed to validate our findings.
We explore the dynamic interaction between proton beams and perovskite solar cells (PSCs), investigating their radiation resistance for space applications. The study starts with the fitting of SCAPS-1D simulation data against experimentally fabricated CsPbI3-based PSCs under AM1.5 light. We systematically optimized the PSC structure by varying the CsPbI3 film's thickness, bandgap, bulk defect concentration, and operating temperature. These optimizations led to an improved efficiency from 18.21 % to 19.69 % under AM0 space illumination. Furthermore, complementary SRIM/TRIM calculations demonstrate that low-energy protons (0.05-0.1 MeV) are extensively confined within the perovskite. Such confinement the likelihood of trap-assisted recombination and reduces charge extraction efficiency. Higher-energy protons (0.5-1 MeV) proceed further into the PSC stack and deliver less damage to the perovskite but have potential long-term effects on interfaces. Using TALYS 2.0 software, we demonstrate that many stable and radioactive nuclides were created from this irradiation, but the level of activity was minimal and poses negligible effect. This integrated multiphysics framework offers a reliable methodology for designing radiation-tolerant PSCs, supporting their deployment in space-based photovoltaic (PV) systems.
