1,720,956 research outputs found
EFEK SINERGETIK ION IODIDA TERHADAP INHIBISI KOROSI BAJA DENGAN EKSTRAK DAUN SIAMIH (Ageratum conyzoides L) DALAM LARUTAN ASAM KLORIDA
Get PDFABSTRACT
SYNERGETIC EFFECT OF IODIDE ION ON THE CORROSION INHIBITION OF MILD STEEL USING EXTRACT OF SIAMIH LEAVES (Ageratum conyzoides L) IN HYDROCHLORIC ACID MEDIUM
By:
Lovera Anggraini, S.Si (BP: 1520413003)
Prof. Dr. Emriadi, MS dan Prof. Dr. Admin Alif
Siamih leaf extract (Ageratum conyzoides L) was tested as a corrosion inhibitor of steel St. 37 in HCl medium without and with the addition of iodide ions using the method of weight loss, potentiodynamic polarization and SEM analysis. Based on the method of weight loss can be seen that the corrosion rate decreases with the addition of siamih leaf extract. The highest inhibition efficiency is 85.33% with the addition of extract 8 g / L, without the addition of iodide ions. The highest inhibition efficiency is 98,51% with the addition of extract 8 g/L plus 8 g/L iodide ions. Influence of temperature causes the inhibition efficiency decreases with increasing temperature. Potentiodynamic polarization measurements showed that the leaf extract siamih a mixed type inhibitor. SEM analysis showed differences steel surface immersed in HCl without and with the addition of Siamih leaf extract. Siamih leaf extract adsorption on the steel surface according to the Langmuir adsorption isotherm.
Key words: Melastoma candidum D.Don, corrosion inhibitor, weight loss, potentiodynamic polarization, Langmuir adsorption isoterm, SEM, synergetic effect.
ABSTRACT
SYNERGETIC EFFECT OF IODIDE ION ON THE CORROSION INHIBITION OF MILD STEEL USING EXTRACT OF SIAMIH LEAVES (Ageratum conyzoides L) IN HYDROCHLORIC ACID MEDIUM
By:
Lovera Anggraini, S.Si (BP: 1520413003)
Prof. Dr. Emriadi, MS dan Prof. Dr. Admin Alif
Siamih leaf extract (Ageratum conyzoides L) was tested as a corrosion inhibitor of steel St. 37 in HCl medium without and with the addition of iodide ions using the method of weight loss, potentiodynamic polarization and SEM analysis. Based on the method of weight loss can be seen that the corrosion rate decreases with the addition of siamih leaf extract. The highest inhibition efficiency is 85.33% with the addition of extract 8 g / L, without the addition of iodide ions. The highest inhibition efficiency is 98,51% with the addition of extract 8 g/L plus 8 g/L iodide ions. Influence of temperature causes the inhibition efficiency decreases with increasing temperature. Potentiodynamic polarization measurements showed that the leaf extract siamih a mixed type inhibitor. SEM analysis showed differences steel surface immersed in HCl without and with the addition of Siamih leaf extract. Siamih leaf extract adsorption on the steel surface according to the Langmuir adsorption isotherm.
Key words: Melastoma candidum D.Don, corrosion inhibitor, weight loss, potentiodynamic polarization, Langmuir adsorption isoterm, SEM, synergetic effect
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
PEMANFAATAN EKSTRAK DAUN SENGGANI (MELASTOMA CANDIDUM D.DON) SEBAGAI INHIBITOR KOROSI BAJA St. 37 DALAM MEDIUM ASAM KLORIDA
No full textEkstrak daun senggani (Melastoma candidum D.Don) diuji sebagai inhibitor
korosi baja St. 37 dalam medium HCl dengan menggunakan metoda
kehilangan berat, polarisasi potensiodinamik dan analisis SEM. Berdasarkan
metoda kehilangan berat dapat diketahui bahwa laju korosi menurun dengan
adanya penambahan ekstrak daun senggani. Efisiensi inhibisi tertinggi adalah
67% dengan penambahan ekstrak 0,8 %. Pengaruh temperatur menyebabkan
efisiensi inhibisi menurun dengan peningkatan temperatur. Pengukuran
polarisasi potensiodinamik menunjukkan bahwa ekstrak daun senggani
merupakan inhibitor jenis campuran. Analisis SEM menunjukkan adanya
perbedaan permukaan baja yang direndam dalam HCl tanpa dan dengan
adanya penambahan ekstrak daun senggani. Adsorpsi ekstrak daun senggani
pada permukaan baja sesuai dengan isoterm Langmuir.
Kata kunci: Melastoma candidum D.Don, inhibisi korosi, kehilangan berat,
polarisasi potensiodinamik, isoterm Langmuir, SEM
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
