| 1. |
- Abutalib, M. M., et al.
(författare)
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Fe3O4/Co3O4-TiO2 S-scheme photocatalyst for degradation of organic pollutants and H-2 production under natural sunlight
- 2022
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Ingår i: Journal of Materials Research and Technology. - : Elsevier Editora Ltda. - 2238-7854. ; 20, s. 1043-1056
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Tidskriftsartikel (refereegranskat)abstract
- Sunlight responsible mono-and co-doped TiO2 nanoparticles (Con+ and Fen+) were prepared via sol-gel technique. The X-ray diffraction (XRD) results showed no phase change of TiO2 was observed after the addition of Con+ and Fen+ ions. Diffuse reflectance spectra (DRS) results showed a significant red-shift of the absorption edge after doping TiO2 by Co(n )and Fen+ and the band gap energy reduced sharply from 3.10 to 1.72 eV. X-ray photoelectron spectroscopy (XPS) results emphasized the existence of multivalent states of Co2+, Co3+, Fe2+ and Fe3+. The results of ultraviolet photoelectron spectroscopy (UPS), work function, electron spin resonance (ESR) illustrated the Fe3O4/Co3O4-TiO2 formed of ternary hetero-junctions. The photocatalytic performance of the prepared photocatalysts was determined for photodegradation of tetracycline (TC) and phenol (Pl) and production of hydrogen. The results illustrated the existence of multivalent states of Fe and Co ions (Co2+, Co3+, Fe2+ and Fe3+) together improved the solar light absorption, inhibited the recombination of photo -generated charges and consequently enhanced the photocatalytic efficiency of TiO2 compared with mono-doped TiO2 (Co3O4/TiO2 and Fe3O4/TiO2). The sample with 5%Fe3O4/ Co(3)O(4)4-TiO2 showed the highest photoactivity. The mineralization (TOC), photodegradation mechanism and reusability of prepared photocatalysts were also studied. The Fe3O4/Co3O4-TiO2 nanoparticles showed high photoactivity and stability and can be adopted as a promising materials for different environmental and H-2 production applications. (C) 2022 The Author(s). Published by Elsevier B.V.
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| 2. |
- Abutalib, M. M., et al.
(författare)
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Preparation of rGO/FeMoO4 as high-performance photocatalyst for degradation of malachite green, phenol and H2 evolution under natural sunlight
- 2022
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Ingår i: International journal of hydrogen energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0360-3199 .- 1879-3487. ; 47:77, s. 32955-32968
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Tidskriftsartikel (refereegranskat)abstract
- FeMoO4 and rGO/FeMoO4 nanocomposites were successfully prepared by a facile hydro-thermal method. The XRD results confirmed that the FeMoO4 has a monometallic b-FeMoO4 crystalline phase while the rGO/FeMoO4 showed both monometallic a-and b-FeMoO4 phases where b-FeMoO4 is the predominant phase. The reduction of graphene oxide (GO) to reduced graphene oxide (rGO) was performed without using any chemical reductions. UV-Vis results showed that the visible light absorption and band gap energy were enhanced after the addition of rGO. The prepared samples were successfully applied for degradation of malachite green (MG) and phenol (Ph) and for H2 evolution under natural solar light irradiation. All the nanocomposites showed higher photocatalytic activities compared with pure FeMoO4 photocatalyst, and the 10%rGO/FeMoO4 gave the highest photodegradation performance for MG and Ph and for H2 evolution. The photodegradation results revealed that the rGO content played the crucial factor in the photodegradation of MG and Ph, and H2 evolution. The mineralization (TOC), photodegradation mechanism and degradation kinetics of MG and Ph were discussed.
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| 3. |
- Hezam, F. A., et al.
(författare)
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Synthesis and physical properties of spinel ferrites/MWCNTs hybrids nanocomposites for energy storage and photocatalytic applications
- 2020
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Ingår i: Physica. B, Condensed matter. - : ELSEVIER. - 0921-4526 .- 1873-2135. ; 596
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Tidskriftsartikel (refereegranskat)abstract
- NiFe2O4, NiFe2O4/MWCNTs, CoFe2O4 and CoFe2O4/MWCNTs nanocomposites were synthesized via the hydrothermal method. XRD, FT-IR, SEM and TEM techniques have been used to investigate the structural properties. CoFe2O4/MWCNTs has a good morphology with small sizes compared to NiFe2O4/MWCNTs. UV-vis. DRS analysis showed that the nanocomposites have high absorbance of irradiation in the whole range of the wavelengths (200-900 nm). The optical energy gaps of the nanocomposites have been calculated. Using VSM technique, NiFe2O4 and NiFe2O4/MWCNTs exhibited super-paramagnetism at room temperature, while CoFe2O4 and CoFe2O4/MWCNTs exhibited ferromagnetism with saturation magnetization of 37.8, 25.5, 66.46 and 51.49 emu/g, respectively. The AC conductivity measurements for NiFe2O4 and CoFe2O4 NPs revealed an increase in conductivity with the addition of MWCNTs as well as the dielectric measurements. The structural and electrical properties of CoFe2O4/MWCNTs make it of potential for capacitive storage and optoelectronic devices. Promising magnetic-optical properties can be utilized for developing recyclable photocatalytic applications.
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| 4. |
- Alghamdi, Haifa Mohammed, et al.
(författare)
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Effect of the Fe2O3/TiO2 Nanoparticles on the Structural, Mechanical, Electrical Properties and Antibacterial Activity of the Biodegradable Chitosan/Polyvinyl Alcohol Blend for Food Packaging
- 2022
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Ingår i: Journal of Polymers and the Environment. - : SPRINGER. - 1566-2543 .- 1572-8919. ; 30, s. 3865-3874
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Tidskriftsartikel (refereegranskat)abstract
- As the request for ready-made food grows, its more important than ever to develop effective antimicrobial food packaging materials to assure foods microbiological safety. The solvent casting method was used to create a chitosan (Cs)/polyvinyl alcohol (PVA) blend based active food packaging material enhanced with Fe2O3/TiO2 (FeTiO2) nanoparticles. The prepared films were characterized by TEM, XRD, FTIR, and ac conductivity. The structural alterations occurring in the nanocomposites are indicated by FTIR spectra and XRD investigations. The AC conductivity and dielectric characteristics of nanocomposites were dramatically improved as the nanoparticle loading was raised. The mechanical properties of blend/FeTiO2 nanocomposites films were better than pure blend film. The nanocomposites films had good antibacterial activity and mechanical properties, suggesting that they could be a viable alternative to non-biodegradable packaging material.
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| 5. |
- Alghamdi, Haifa Mohammed, et al.
(författare)
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Modification and development of high bioactivities and environmentally safe polymer nanocomposites doped by Ni/ZnO nanohybrid for food packaging applications
- 2022
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Ingår i: JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T. - : ELSEVIER. - 2238-7854. ; 19, s. 3421-3432
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to develop a sodium alginate (50%NaAlg)/polyethylene oxide (50%PEO) blend-based film loaded with nickel and zinc oxide nanoparticles (Ni/ZnO NPs) as a rein-forcing and antibacterial agent. The Ni/ZnO NPs as nanohybrid were synthesized via the sol-gel method at different concentrations (0.0, 5.0, 10.0, 15.0, 20.0 wt.%). The solution cast approach was utilized to create polymer nanocomposites samples from NaAlg/PEO/Ni/ZnO NPs for application in bioactive food packaging. The films were characterized using various procedures in detail. With the addition of Ni/ZnO, the XRD confirms the expansion of amorphous nature within NaAlg/PEO. The crystallinity degree of NaAlg/PEO-Ni/ZnO nanocomposite were decreased from 47 to 25%. The interactions between the compo-nents of NaAlg/PEO and Ni/ZnO NPs are revealed by FTIR findings. The bio-degradable nanocomposites dielectric behavior, electrical conductivity as well as mechanical prop-erties, were investigated. With the addition of Ni/ZnO NPs, the dielectric and AC conduc-tivity properties of the nanocomposites improved with the increase in the concentrations of Ni/ZnO NPs. The loading of Ni/ZnO nanoparticles increased the mechanical character-istics of the nanocomposite, such as tensile strength increased from 30.18 to 72.34, stiff-ness increased from 18.78 to 38.42, and Youngs Modulus increased from 8.24 to 29.76. The antibacterial activity of nanocomposites films was examined against Gram-negative (Escherichia coli), Gram-positive (Staphylococcus aureus), Aspergillus niger (fungus) and Candida albicans (yeast). Though the tested NaAlg/PEO blend did not indicate any activity against the microbial strains, when Ni/ZnO NPs were added, activity against E. coli, S. aureus, fungus and yeast was enhanced. The water solubility of nanocomposites films reduced from 65.5% to 9.81% with increasing of Ni/ZnO NPs content. The present study shown that NaAlg/PEO-Ni/ZnO films were more effective in inhibiting bacteria growth than pure NaAlg/PEO film, confirming the nanocomposites films potential application as anti-microbial food packaging.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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| 6. |
- Alsalmah, Hessa A., et al.
(författare)
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Optical, conductivity, dielectric, and magnetic properties of polymer nanocomposite based on PAM/cs matrix and ZnFe2O4 NPs for use in magneto-electronic and energy storage capacitor devices
- 2024
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Ingår i: Ceramics International. - : ELSEVIER SCI LTD. - 0272-8842 .- 1873-3956. ; 50:7, s. 12167-12174
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a cast synthesis approach was used to create flexible nanocomposite films made of polyacrylamide (PAM), chitosan (Cs), and zinc ferrite nanoparticles (ZnFe2O4 NPs). XRD analysis was used to examine the composite structure. They demonstrated the effective interaction between ZnFe2O4 NPs and PAM/Cs blend. As the concentration of nanomaterial in the host polymer matrix grew, it was observed that the PAM/Cs matrix's direct and indirect energy band gaps decreased while its absorbance of ultraviolet-visible radiations increased. The nanocomposite's AC conductivity was significantly higher than that of the blend, and 2.5 wt percent of the nanocomposite showed the highest electrical conductivity. It was observed that as frequency raised, the epsilon ' and epsilon '' declined though the concentration of nanoparticles enhanced these characteristics. Because of the high dielectric permittivity of ZnFe2O4, the values of epsilon ' and epsilon '' raised as ZnFe2O4 were higher. The outcome of the vibrating sample magnetometer (VSM) demonstrated the ferromagnetic property of the produced nanocomposites. Furthermore, the VSM study shows that as the nanoparticles content increases, the PAM/Cs/ZnFe2O4 nanocomposites' Ms, Hc, and Mr also increase. These PAM/Cs/ZnFe2O4 films were shown by the experimental results to be promising candidates for bandgap-regulated materials, electromagnetic interference shielders, frequency tunable nanodielectric, and flexible dielectric substrates for future microelectronic, optoelectronic technologies, and capacitive energy storage.
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| 7. |
- Alsalmah, Hessa A., et al.
(författare)
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Synthesis and characterization of PEG/CS-AgNO3 polymer nanocomposites for flexible optoelectronic and energy storage applications
- 2024
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Ingår i: Polymer Composites. - : WILEY. - 0272-8397 .- 1548-0569.
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Tidskriftsartikel (refereegranskat)abstract
- The Polyethylene glycol (PEG) and Chitosan (CS)/silver nitrate (AgNO3) thin films were prepared by utilizing the casting technique to enhance their optical, dielectric, and electrical properties. Their physicochemical characteristics were investigated using a variety of techniques. The FT-IR study demonstrates that the addition of AgNO3 NPs results in a discernible difference in the intensities and locations of vibrational peaks of all bands, supporting the incorporation of AgNO(3)NPs inside the PEG/CS. The XRD analysis indicates that the peak at 2 theta = 23.1(degrees) broadens and strengthens proportionally with the increase of AgNO3 NPs. This observation suggests that the incorporation of AgNO3 NPs into PEG/CS results in a greater degree of amorphous characteristics compared to the PEG/CS blend. Additionally, when the amount of AgNO3 NPs increases in the PEG/CS, the energy band gap decreases, resulting in the creation of localized states between the valence and conduction bands. These polymer nanocomposite films' electrical conductivity, dielectric constant, and dielectric loss all increased with frequency increased and showed variance for various composite concentrations. These AgNO(3)NPs/PEG/CS films can be promising options for frequency-tunable nanodielectrics, flexible dielectric substrates, and bandgap-regulated materials for upcoming microelectronic, capacitive energy storage, and optoelectronic technologies, according to the experimental results.
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| 8. |
- Wan, Guihong, et al.
(författare)
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Prediction of early-stage melanoma recurrence using clinical and histopathologic features
- 2022
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Ingår i: NPJ precision oncology. - : Springer Science and Business Media LLC. - 2397-768X. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Prognostic analysis for early-stage (stage I/II) melanomas is of paramount importance for customized surveillance and treatment plans. Since immune checkpoint inhibitors have recently been approved for stage IIB and IIC melanomas, prognostic tools to identify patients at high risk of recurrence have become even more critical. This study aims to assess the effectiveness of machine-learning algorithms in predicting melanoma recurrence using clinical and histopathologic features from Electronic Health Records (EHRs). We collected 1720 early-stage melanomas: 1172 from the Mass General Brigham healthcare system (MGB) and 548 from the Dana-Farber Cancer Institute (DFCI). We extracted 36 clinicopathologic features and used them to predict the recurrence risk with supervised machine-learning algorithms. Models were evaluated internally and externally: (1) five-fold cross-validation of the MGB cohort; (2) the MGB cohort for training and the DFCI cohort for testing independently. In the internal and external validations, respectively, we achieved a recurrence classification performance of AUC: 0.845 and 0.812, and a time-to-event prediction performance of time-dependent AUC: 0.853 and 0.820. Breslow tumor thickness and mitotic rate were identified as the most predictive features. Our results suggest that machine-learning algorithms can extract predictive signals from clinicopathologic features for early-stage melanoma recurrence prediction, which will enable the identification of patients that may benefit from adjuvant immunotherapy.
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