1,720,958 research outputs found
Green synthesis of ZnO nanoparticles by Myrtus communis plant extract with investigation of effect of precursor, calcination temperature and study of photocatalytic performance
No full textAn elegant approach was made for the synthesis of ZnO nanoparticles by Myrtus Communis plant extract using two different precursors at variable temperatures (400,600, and 800 degrees C). The properties of nanoparticles were investigated with PXRD, SEM-EDX, PL, FTIR, and UV-Vis spectrometer. PXRD results inferred that all samples have pure wurtzite phase confirming with JCPDS card No. 36-1451. The UV-Vis spectroscopy exhibited that all estimated bandgaps are a little less than those for bulk ZnO. It was confirmed by EDX spectra that Zn and O atoms are the main compositions of the material. FESEM images displayed hexagonal-like shapes of nanoparticles for all samples prepared with acetate. Hexagonal morphology was observed in the samples having green emission at room temperature PL measurements. It was seen that methylene blue degraded about 90 % after about 20 min of irradiation of UV light for samples calcined at 400 degrees C. It was also observed that the samples calcined at 400 degrees C degraded methylene blue by approximately 99 %. This work is the first paper on the morphological utilization and photocatalytic performance of green synthesized ZnO with Myrtus communis plant extract with various calcination temperatures via two different precursor reagents.Department of Scientific Research Projects (BAP) of Osmaniye Korkut Ata University [OKUBAP-2022-PT2-005]This research was supported by the Department of Scientific Research Projects (BAP) of Osmaniye Korkut Ata University under the Project Number OKUBAP-2022-PT2-005. The author thanks Fuat Bozok for providing the plant and support
A Detailed Study on the Structural, Electrical and Optical Properties of (ZnO-GeO2) Substituted In2O3 Transparent Conducting Oxide
Get PDFIn this study, ZnO and GeO2 cosubstituted In2O3 ternary system is investigated with various characterization methods for optical, electrical and structural properties. This new transparent conducting oxide prepared different composition which can be symbolized as ZnxIn2-2xGexO3 samples optical properties show increasing increase the optical gap from 2.94 eV to 3.16 eV. Conductivity values for is about 308 S/cm and 1060 S/cm for unreduced and reduced samples respectively. The reduced conductivity of Zn0.476In1.032Ge0.476O3 is about 135 S/cm and for this composition samples are phase pure for new fluorite related phase. Thus, this study stresses the importance of cosubstitution to decrease amount of indium and understanding the various results for bulk samples
Characterization and photocatalytic activity of ZnO nanoparticles by green synthesis method
No full textIn this work, zinc oxide nanoparticles have been synthesized by green synthesis technique using sodium hydroxide and zinc nitrate, with and without calcination. In this research, Myrtus communis extract was used along with three different alkaline molar ratios (0.5 M, 1 M, and 2 M) to successfully synthesize ZnO nanoparticles (NPs) from the same precursor. In the calcined samples, this process was carried out at 800 °C. X-ray diffraction, scanning electron microscopy, and diffuse reflectance spectra were used to explore the structural, morphological, and optical features of ZnO nanoparticles. The XRD peaks confirm the successfully synthesized hexagonal wurtzite zinc oxide and are in full conformity with the published data of the JCPDS: 36–145. With high absorption peaks at about 370 nm wavelength, UV-Vis spectroscopy further supported the ZnO NPs' strong optical properties. Morphology and topography were discovered by SEM analysis and displayed the evolution of ZnO nanowires around 10 µm length with calcination. No nanowire formation was observed in the uncalcined samples. The results demonstrated that the degradation efficiency of ZnO nanoparticles is dependent primarily on the UV exposure time and morpholgy. When ZnO with 1 M NaOH calcined at 800 °C is used, the maximum MB degradation of about 99% is achieved. Methyl blue photodegradation follows the first-order Langmuir–Hinshelwood kinetic model. © 2023 Elsevier GmbHOsmaniye Korkut Ata University, (OKÜBAP-2022-PT2–005, OKÜBAP-2022-PT2–036
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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