6 research outputs found
Effect of Saccharum officinarum Juice Extract Additive on the Electrodeposition of Zinc on Mild Steel in Acid Chloride Solution
Experimental investigations have been performed to examine the electrodeposition of zinc on mild steel in acid chloride solution using as additive different concentrations of saccharum officinarum (sugarcane) juice extracts. The experiments were performed under different plating time, different additive concentrations and fixed pH conditions. Zinc electrodeposition on mild steel was performed using a DC – supply at defined operating parameters. The surface of the plated steel was examined using scanning electron microscopy (SEM); and Energy Dispersive Spectroscopy (EDS) for surface elemental composition analysis. Different surface characteristics were obtained depending upon the concentration of the additive and the plating time. The corrosion resistance of the plated surface was also determined by gravimetric method. The quality of electrodeposition of zinc was good as indicated by the plated surface microstructural morpholog
Single solid source precursor route to the synthesis of MOCVD Cu-Cd-S thin films
Bis-(morpholinodithiato-s,s')-Cu-Cd was synthesized from appropriate reagents as a single solid source precursor and characterized using particle induced x-ray emission (PIXE), Fourier transform infrared (FTIR) spectroscopy and differential thermal analysis (DTA). Cu-Cd-S thin films were deposited on sodalime glass substrate using MOCVD technique at temperatures in the range 360 °C–450 °C. The films were further characterized using Rutherford backscattering spectroscopy (RBS), x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy and four-point probe technique. PIXE revealed that the synthesized precursor contained the expected elements which led to the successful deposition of the Cu-Cd-S thin films. FTIR ascertained that the organic ligand actually attached to the metals. DTA analysis showed that the synthesized precursor was thermally stable and could pyrolyzed around 300 and 500 °C. RBS of the deposited films showed that the stoichiometry and the thickness depended on deposition temperature. XRD analysis revealed that the films deposited at 360 and 380 °C are amorphous while those deposited at 400 °C to 450 °C showed peaks, which supported the possible co-existence of CuS and CdS as Cu-Cd-S, with an improvement in the crystallinity as substrate temperature increased. SEM showed that the films are uniform and crack-free, in which the morphology strongly depended on substrate temperature. Optical analysis revealed that the films have high absorbance in the UV region and high transmittance in the visible and near infrared region, in which direct band gap energy of 2.36 to 2.14 eV was obtained as deposition temperature increased. Other optical parameters such as Urbach energy, refractive index, extinction coefficient, dielectric constant also increased as the deposition temperature increased. Electrical analysis showed that resistivity is temperature dependent as it reduced as deposition temperature increased.http://iopscience.iop.org/journal/2053-15912020-09-13hj2020Physic
Optimization of graphene oxide through various Hummers' methods and comparative reduction using green approach
Graphene oxide (GO) was synthesized using three techniques and was reduced using two reducers' extracts from neem and pumpkin leaves. The obtained GOs and RGOs were characterized using Fourier infra-red (FTIR) spectroscopy, Raman spectroscopy, UV–visible spectrophotometry, energy dispersive x-ray spectroscopy (EDX) and scanning electron microscopy (SEM). Results revealed that all the three methods used are capable of producing GO with various levels of oxidation. FTIR spectra of RGOs showed that the Cdouble bondO signature of GOs at 1730–1740 cm−1 were eliminated after reduction. Other characterization results of the RGOs revealed that both the neem and pumpkin extracts are capable of reducing the synthesized GO. With all these, it can be concluded that the extracts of neem and pumpkin are good reducing agents. The neem and pumpkin extracts, which are ecofriendly can replace the use of hazardous chemicals that are not ecofriendly.http://www.elsevier.com/locate/diamond2023-05-18hj2022Physic
Accurate Diagnosis?:Exploring Convergence and Divergence in Non-Western Missionary and Sociological Master Narratives of Christian Decline in Western Europe
Non-Western Christian missionaries from a variety of backgrounds represent Europe as in decline in terms of its religiosity and morals. Such evaluations are set against a backdrop of Christian demographic shift from the global North to the global South and secularization theory. The shift in demographics is, however, unfinished, as is the inversion of relations implied by the vocal, critical presence of Southern Christians in Europe. There is great religious variety within Europe, the West and the global South. Hence scholars are developing fresh theoretical lenses to take better account of contexts and connections in analyses, and further research into the relationship between rhetoric and reality is called for
Conceptualizing racialized black political activity within European spaces: a political opportunities approach
African presence in Europe can be traced back to Roman times, yet African peoples within European spaces are continually perceived and often treated as new migrants with no sense of an historical attachment to European soil. This paper seeks to understand and challenge this conception of black migrants to Europe by focusing on the community and political activities of black subjects in European spaces. Using Britain as a primary reference point, the paper argues that the unfolding nature of black political activity in European spaces emerges as a result of dynamic interactions between black protagonists and the state. The nature of these interactions it is argued are racialized in character and that black community organizations and individuals play a crucial role in determining the forms and nature of political activity and outcomes that operate under the guise of minority ethnic mobilization. This paper argues a point that is often overlooked in the literature that focuses on African and other immigrants to Europe as recent migrants with problems. The paper uses a refined political opportunities approach and focuses on state practices and black community organizational practices between the First and Second World Wars to outline the varied nature of black community and political activity in an era of state antagonism towards black populations at home and abroad. The paper argues that context, state power and action, and the activities and ideas of black community organizations interact in dynamic ways to account for the changing nature of black political activity in European spaces