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1.
Heliyon ; 10(7): e29170, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38623225

RESUMO

The increasing depletion of reserves of natural resources has led to a growing worldwide focus on the exploitation of available waste in new domains. The presence of weedy plants is pervasive on a global scale and has detrimental effects on several aspects of the environment, agriculture, and people's health. Therefore, repurposing these Agri-weed plants for beneficial purposes would be a significant achievement. Furthermore, since raw materials constitute a substantial portion of manufacturing costs, using weeds as a feasible substitute for raw materials might potentially provide considerable advantages for manufacturers. In this study, an endeavor has been made to the utilization of agricultural waste "Urena Lobata", for the purpose of paper production. In the interim, the utilization of Urena Lobata as an alternative and sustainable raw material for pulp and paper industry could potentially offer a beneficial approach to mitigation of deforestation. The effective production of handsheets with weights of 70 g/m2 and 80 g/m2 was achieved using Urena Lobata fiber, Bleached Urena Lobata Fiber, and hardwood kraft pulp. Mechanical characteristics of handsheet's were comprehensively examined by the bursting index, tensile strength, tear index, brightness percentage and scanning electron microscope for handsheet's morphology. The results show that the handsheets produced by Urena Lobata fiber exhibit a much lower brightness percentage, high tensile strength and bursting index. Alongside, handsheets by bleached Urena Lobata fiber indicate higher brightness percentage, satisfactory values for tensile strength, bursting index, and tear index. The prepared materials are suitable for a broad spectrum of prospective applications, encompassing newsprint, tissue paper, filtration paper as well as high-quality writing and printing paper.

2.
ACS Omega ; 7(24): 20731-20740, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35755349

RESUMO

This study reports the formation of Er-doped nanocrystalline cobalt ferrite with the formula CoFe2-x Er x O4 (0.0 ≤ x ≤ 0.10) from nontoxic metal precursors Co(NO3)2·6H2O, Fe(NO3)3·9H2O, and Er(NO3)3·5H2O through an easy and economical sol-gel route in which citric acid is served as the chelating agent. The as-prepared powder was annealed at 700 °C for 3 h in ambient air to get the required spinel structure. The annealed samples were subjected to structural and magnetic characterization. The X-ray diffraction (XRD) data of the samples confirmed the cubic spinel structure formation. The average crystallite size evaluated from XRD data increased from 21 to 34 nm with the substitution of Er due to the larger atomic size of Er3+ than Fe3+. Moreover, the crystallite size obtained from XRD data are well matched with the particle size measured from transmission electron microscopy images. The lattice parameters obtained from XRD data agree well with the values estimated from theoretical cation distribution and Rietveld refinement calculation. The hysteresis curve exhibits the particles are soft ferromagnetic and the coercivity increased from 54.7 to 76.6 kA/m with maximum saturation magnetization, M s = 61 emug-1 for 0.10 Er content. The squareness ratios were found to be less than 0.5, which indicates the single-domain nature of our particles. The blocking temperature measured from field cooled-zero field cooled curves is T B > 350 K for all the samples, which is much higher than the room temperature (300 K). The enhancement of saturation magnetization and coercivity has been explained based on the crystallite size, anisotropy constant, and cation distribution. Thus, the structural and magnetic properties of CoFe2O4 nanoparticles (NPs) can be tuned by Er incorporation and these NPs can be applied in different soft magnetic devices.

4.
Microscopy (Oxf) ; 63(2): 111-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24363441

RESUMO

Electron diffraction and electron energy-loss spectroscopy (EELS) studies were conducted on bundles of single-walled carbon nanotubes encaging coronene molecules (coronenes@SWCNTs). Selected area electron diffraction (SAED) pattern of the coronenes@SWCNTs suggests that the coronene molecules inside the SWCNTs are separated into segments. Each segment is a stack consisting of ∼ 10 molecules and has a different tilted condition with respect to the nanotube axis. EELS spectra of the coronenes@SWCNTs show characteristic structures due to interband transitions between the van Hove singularities of the SWCNTs, and also π-plasmon and π + σ plasmon (volume plasmon) peaks. The volume plasmon energy of 23.0 eV for the coronene@SWCNTs is larger than that of an empty SWCNT bundle, indicating a contribution from the valence electrons of the coronene molecules. This value for the volume plasmon energy was reproduced using a model with an average of 85% filling of the SWCNTs by the coronene molecules. Therefore, both the SAED and EELS observations suggest that the SWCNTs are highly filled with coronene molecules. Further indication was that interband transition energies of coronene molecules of the present coronenes@SWCNTs material may be different from those in isolated ones and/or in solid state.

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