بحوث سكوبس — م.د. صفا حسن محمد

The widespread usage of the lanthanide group in the literature fascinated many researchers all over the world in recent years. Comprehensive compact information in imaging and therapeutic applications leads to presenting the recent reports in favor of supporting photodynamic treatment in both in vivo and in vitro. This review introduces upconversion nanoparticles (UCNPs) from a quite profound standpoint from general details to sophisticated cutting-edge technology in biomedical engineering, imaging, and drug delivery for introducing a professional level of designing nano-drug carriers, theranostic applications in order to fulfill effective therapeutic approaches for cancer treatment. This study will also interpret mechanisms, different synthesis methods, and various functionalized of UCNPs in nanoscience. © 2023 Elsevier B.V.

Shape memory alloys (SMAs) are materials that both industry and research are interested in. SMAs are materials that, after a seemingly irreversible deformation, can return to their original shape. This alloy has poor yield strength when heated below its transformation temperature and will simply deform into any new shape that it can retain. SMA changes its crystal structure and returns to its original shape when heated above its transformation temperature. Because of their superior properties such as shape memory effect (SME) and pseudoelasticity, which are related to the specific way the biocompatibility, phase transformation temperatures, corrosion resistance, high wear resistance, and high strength, SMAs can be utilized in a variety of applications. This paper focuses on the features of SMAs, such as shape memory effect and superelasticity, as well as their types, fabrication processes, and the most significant applications. © 2023 Author(s).

Due to their high resistance to real operational conditions, perovskite-based solar cells (PSCs) with dopant-free inorganic hole transport materials are good candidates for PSC commercialization. It should be noted that these types of PSCs have recorded lower power conversion efficiency (PCE) compared to Spiro-OMeTAD-based PSCs, with a recent PCE record of 25.8%. Here, we introduced nitrosonium tetrafluoroborate (NOBF4) into the perovskite precursor to improve hole carriers' transport between the perovskite layer and copper phthalocyanine (CuPc) layer. Electrochemical impedance spectroscopy (EIS) showed that NOBF4 additive reduces series resistance in PSC devices, which may be due to a band alignment between the valance band of perovskite and CuPc. In addition, due to a partial BF4− substitution with I− ions during the fabrication process, the crystallinity properties of the perovskite layer are tailored, leading to the formation of a film with larger grains. By employing NOBF4 material, in the obtained perovskite layer, a small unreacted lead iodide (PbI2) amount remained. In total, the NOBF4 additive brings a maximum efficiency of 16.77% for the target solar cell group, higher than the 14.42% for control devices. The target PSCs, compared with the control PSCs, showed improved air stability results from the suppressed PbI2 with enlarged perovskite grains. © 2022 Elsevier B.V.

With the increase in the importance of using green energy sources to meet the world's energy demands, attempts have been made to push perovskite solar cell technology toward industrialization all around the world. Improving the properties of perovskite materials as the heart of PSCs is one of the methods to fabricate favorable photovoltaic (PV) solar cells based on perovskites. Here, cadmium chloride (CdCl2) was used as an additive source for the perovskite precursor to improve its PV properties. Results indicated CdCl2 improves the perovskite growth and tailors its crystalline properties, suggesting boosted charge transport processes in the bulk and interfaces of the perovskite layer with electron-hole transport layers. Overall, by incorporation of 1.0% into the MAPbI3 layer, a maximum power conversion efficiency of 15.28% was recorded for perovskite-based solar cells, higher than the 12.17% for the control devices. The developed method not only improved the PV performance of devices but also boosted the stability behavior of solar cells due to the passivated domain boundaries and enhanced hydrophobicity in the CdCl2-based devices. © 2022 The Royal Society of Chemistry.

The photocatalytic activity of fluorine-doped zinc oxide (ZnO-F) nanoparticles (NPs) is improved with the assistance of polyvinyl alcohol (PVA). ZnO-F NPs were synthesized through a co-precipitation reaction of zinc nitrate and ammonium fluoride. The obtained ZnO-F NPs were capped with various amounts of PVA, utilizing a facile solution-based approach. XRD patterns showed that PVA polymer didn't alter the crystallinity properties of ZnO NPs and its hexagonal wurtzite structure with prominent orientations of (1 0 0), (0 0 2), and (1 0 1) was preserved. While UV–Vis spectra revealed that the optical band of nanocomposites varies with increasing amounts of PVA from 2.10 eV for ZnO-F NPs to 2.13 eV for 4% PVA loaded-ZnO-F. The data showed when the weight ratio of PVA polymer with respect to the neat ZnO NPs is fixed at 4% during the synthesis process, the highest photocatalytic activity for hybrid NPs is achieved. © 2022 Elsevier B.V.

The experiment and histological results for the fourth group of albino mice showed an increase in wound healing by 50%, 56.66%, and 70% after being activated for 3, 5, and 7 min, respectively. The best improvement was observed according to the control group, which had a 40% recovery, and the histological section provided the best result by the fourth group, that there was no inflammatory site with activated Aloe vera exposure to 7 min of plasma. The microwave plasma system, which is designed for preparing materials, showed a high ability to increase the effectiveness of the extracted Aloe vera solution. © 2022 Elsevier B.V.

In the present work, lanthanum oxide (La2O3) was prepared by the refluxing technique using lanthanum nitrate, urea, and double filtered water at 100 °C for various synthesis durations (6, 12, 18, and 24 h) in a water medium. X-ray diffraction (XRD) results suggest that La2O3 belongs to a monoclinic crystalline structure with the average crystallite sizes for La2O3 with 6, 12, 18, and 24 h irradiation samples being determined to be 13.4 nm, 18.7 nm, 22.6 nm, and 27.9 nm, respectively. A scanning electron microscope (SEM) was used to evaluate the morphological merits of the samples. The particle size dimensions of La2O3 are calculated to be 38 nm, 32 nm, 30 nm, and 25 nm for La2O3 with 6, 12, 18, and 24 h irradiation, respectively. The observations of the SEM confirmed that La2O3 was present in nano-sized particles. Fourier transform infrared (FTIR) measurement was used to verify the oxygen groups, and UV-visible spectroscopy was also used to measure absorption spectra. The FTIR spectra showed the La-O bending and stretching vibrations at around 530–620 cm− 1 and 950–1100 cm− 1, respectively. Thermal gravimetric analysis (TGA) was used to investigate the temperature response of the as-prepared samples. The initial weight loss around 110 ºC may be due to the removal of the adsorbed water molecules. Two peaks around 350 ºC and 370 ºC are seen in the DTA curve, which is seen through a very high merger weight loss in the sample. © 2022, The Tunisian Chemical Society and Springer Nature Switzerland AG.

Ultrasonic velocity measurements on ternary blends of aniline + 1-alkanols + hexane are performed at 303 K. The acoustical parameters such as adiabatic compressibility, free length, free volume, and internal pressure are obtained from the experimental data for all the blends, with the view of investigating the exact nature of molecular interaction. The excess values of the above-mentioned parameters have also been estimated and found to be useful in estimating the strength of interaction in the blends. In ternary systems, the occurrence of weak dipole-induced dipole and dipole–dipole interactions of large values is verified. As such, they predict the origin of the interaction of the recommended interaction, potential azeotropic formation/destruction, and the mole of such systems. The analysis reveals that the interactions between the aniline-alcohol complexes predominate over the other hexane interactions. © 2022, The Tunisian Chemical Society and Springer Nature Switzerland AG.

In this study, GO and GO-PEDOT:PSS nanocomposite films were prepared by using the modified Hummer method and spin-coating, respectively. GO-PEDOT:PSS films with different weight ratios of GO (0.015, 0.03, 0.045 and 0.06) were prepared to study the effect of the GO additive on nitrogen dioxide (NO2) sensing performance. XRD and AFM were used to determine the crystal structure and the topography of the GO-PEDOT:PSS films. The effects of GO concentration and temperature on electrical conductivity and the change in activation energy of PEDOT:PSS films were also investigated. The findings show that as the temperature rises, the electrical resistance reduces, and as the concentration increases, the activation energy decreases. © 2022 World Scientific Publishing Company.

In this study the effect of Cu addition on the phase transformation behavior, microstructure, and micro hardness of equiatomic Ni-Ti shape memory alloy was investigated. NiTiCu SMA prepared with the composition (52.119 % at. Ni, 41.731% at. Ti and Cu 6.15 % at.) and compared with the properties of the equiatomic NiTi SMA with composition (50% at. Ni, 50% at. Ti). Vacuum induction melting method used in the preparation of Both SMAs. The Differential Scanning Calorimetry, Scanning Electron Microscope, X-ray Diffraction Analysis, optical microscope and vicker's microhardness test was used to investigate the characteristics of the equiatomic NiTi and NiTiCu SMAs. The results revealed that when Cu element was added the phase transformation temperatures decreased below body temperature. NiTi matrix phase and Ti2Ni secondary phase exist in both SMA samples, also Cu-rich phase appeared in NiTiCu SMA and this is one of the reasons that lead to increasing the microhardness of alloy when Cu element was added. The value of equiatomic NiTi increases from 238.74 to 329 when Cu element was added (for NiTiCu alloy) after heat treatment. © Published under licence by IOP Publishing Ltd.

In this investigation, Hydroxyapatite/Titania and hydroxyapatite/Alumina porous composites at five various proportions were manufactured by replication method A.K.A the polymeric sponge method. HAp powder was fabricated by a "solid-state reaction"in molar proportion between (TCP)Tri calcium phosphate and Ca(OH)2 Calcium hydroxide. The microstructures were examined by utilizing (XRD), (SEM) and EDX". Incubated for thirty days in SBF (Simulation Body Fluid),a thin layer like apatite formed completely on a bone specially on the surface of the samples was.. There's a very low degeneracy degree when amount of the reinforcements materials increased.. © Published under licence by IOP Publishing Ltd.