1,721,001 research outputs found
Fabrication and characterisation of solid titanium nitride and molybdenum nitride microelectrodes
No full textMetal nitrides have gained interest due to their high melting point, mechanical resistance, thermal and electrical conductivity. To the best of our knowledge, titanium nitride (TiN) and molybdenum nitride (MoN) electrodes have always been prepared as thin films. However, thin film electrodes tend to delaminate or crack during preparation or usage which exposes the underlying substrate and increases their surface area. In addition, the vapour deposition techniques employed to prepare thin films can introduce contaminants to the samples. In this work we prepared solid metal nitride samples, characterised them with a range of physical methods and investigated their electrochemical properties.Our work demonstrates the feasibility of obtaining TiN and MoN from Ti and Mo foils and microwires via nitridation in a NH3 atmosphere. The process was confirmed using energy dispersive X-ray spectroscopy and X-ray diffraction (XRD). The XRD spectra also showed that hexagonal MoN and cubic Mo2N were obtained. This work also demonstrates the viability of fabricating solid TiN and MoN microelectrodes, microdisks and microbands, from the nitrided Ti and Mo samples. Hence a major objective of the project was to assess whether TiN and MoN could be used as alternatives to conventional microelectrode materials such as Pt, Au, and C. To the extent of our knowledge, MoN and TiN wires have never been used to construct microelectrodes.The electrochemical behaviour of the solid TiN and MoN microelectrodes is assessed using different redox mediators to cover a range of redox potentials. The cyclic voltammograms recorded with the untreated TiN microband electrodes showed that the redox processes at positive potentials were not electrochemically reversible. Yet, the electrochemical response was improved after etching the TiN surface with hydrofluoric acid vapour. In contrast, MoN microelectrodes exhibited sigmoidal shape cyclic voltammograms with a plateau region for all redox mediators even without surface treatment. The TiN and MoN microelectrodes exhibited good activity towards the oxygen reduction reaction recorded in pH 1, 7, 10, and 14. The TiN and MoN microelectrodes were also employed to assess their properties towards the reduction of peroxodisulfate, a very strong oxidising agent with a very complex reduction process. This study also employed bare Au, bare Pt, nanostructured Pt, and bismuth-adsorbed Pt microdisk electrodes to search for the electrode that produces a stable and preferably a diffusion-controlled current for the reduction of peroxodisulfate. Cyclic voltammograms with a plateau region were obtained with the nanostructured Pt, bismuth-modified Pt, HF-etched TiN, and MoN microelectrodes but not with the bare Au and bare Pt microelectrodes. However, only MoN microdisks demonstrated a stable steady-state current for the reduction of peroxodisulfate. To our knowledge, no group has observed cyclic voltammograms with a plateau region when employing bare electrodes for the reduction of peroxodisulfate. A linear relationship between the current and concentration was obtained with the MoN microdisk electrodes for concentrations above 0.1 mM. Similarly, the MoN microdisk electrode produced a diffusion-controlled current for scan rates between 5 and 50 V s-1.Overall, the MoN microelectrodes produced more reliable amperometric results than the TiN microelectrode. Thus, the MoN microelectrodes could be exploited as an alternative to the conventional Pt, Au, and C microelectrodes
Solid molybdenum nitride microdisc electrodes: fabrication, characterisation, and application to the reduction of peroxodisulfate
Full text linkA new methodology was developed to fabricate solid molybdenum nitride microdisc electrodes for the first time. The MoN microrods were produced by heating Mo microwires in dry NH3 atmosphere for several hours. They were characterised by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The latter revealed the samples had crystallised in the δ3-MoN phase with a core of γ-Mo2N. Their electrochemical behaviour was probed for the reduction of Ru(NH3)63+. For this fast electron transfer the MoN microdisc electrodes returned similar voltammetric features to Pt microelectrodes. Their amperometric response was further tested with the reduction of peroxodisulfate. In contrast with other electrode materials, the reduction of S2O82− on MoN microdiscs delivered steady state voltammograms with well-defined diffusion controlled plateau. At low sweep rates, the limiting current was consistent with hemispherical diffusion and stable for at least 500 s. The diffusion coefficient of S2O82− derived from these results, 9.5 × 10−6 cm2 s−1, is in excellent agreement with previous work. At high sweep rates, the reduction of peroxodisulfate was found to be complicated by the simultaneous reduction of adsorbates. The results indicate that MoN is an ideal electrode material to monitor the concentration of peroxodisulfate under steady state conditions
3D printable conductive materials for the fabrication of electrochemical sensors:A mini review
Full text linkThe review presents recent developments in the use of conductive materials that can be printed using additive manufacturing (3D printing), enabling the development of mass-produced electrochemical sensors of varying geometries. This review will highlight some key electroanalytical applications of 3D-printed electrochemical sensors and discuss their potential future capabilities
EFEKTIVITAS KONTEN TUTORIAL EDIT VIDEO PADA KEMAMPUAN PRAKTIS EDIT VIDEO MAHASISWA KPI IAIN TULUNGAGUNG
Full text linkABSTRAK
Skripsi dengan judul “Efektivitas Konten Tutorial Edit Video Pada Kemampuan Praktis Edit Video Mahasiswa KPI IAIN Tulungagung” ini ditulis oleh Saiful Arifin dan dibimbing oleh Ibu Ucik Ana Fardila, M.I.Kom.
KPI merupakan salah satu jurusan di IAIN Tulungagung yang memiliki salah satu bidang fokus pada Perfilman dan TV. Selain itu KPI IAIN Tulungagung juga mendorong mahasiswanya untuk mengikuti kompetisi film atau jurnalisme di luar kampus. Fokus Penelitian ini mengkaji efektivitas video tutorial mengedit video pada mahasiswa.
Rumusan masalah dalam penelitian ini adalah 1) Bagaimana pemanfaatan video tutorial edit video terhadap peningkatan kemampuan praktis pada mahasiswa KPI IAIN Tulungagung? 2) Bagaimana efektivitas video tutorial di youtube dengan kemampuan mahasiswa KPI IAIN Tulungagung? 3) Bagaimana peran platform youtube edukasi bagi keberhasilan belajar mahasiswa KPI IAIN Tulungagung?
Penelitian ini menggunakan metode analisis isi dengan pendekatan kualitatif deskriptif, dengan menggunakan pengamatan, wawancara, dan studi kepustakaan sebagai alat ukur pencarian data secara terperinci. Mengolah data berdasarkan informasi langsung dari narasumber, ditambah dengan studi pustaka berdasarkan penelitian yang lalu, sehingga menghasilkan hasil data yang obyektif berdasarkan kondisi dilapangan pada saat ini.
Hasil penelitian ini adalah: 1) Kemampuan mengedit video mahasiswa KPI IAIN Tulungagung dapat meningkat dengan belajar menggunakan video tutorial di youtube. 2) Media sosial youtube terbukti efektif karena mempengaruhi pencapaian akademik maupun non akademik. 3) Sosial media menjadi platform baru bagi mahasiswa sebagai sumber belajar, Sehingga New media dapat menjadi sarana bagi pembelajaran saat ini.
Kata Kunci : Media Youtube, Efektivitas, Peran, Tutorial Edit Video, Cognitive Load (Sweller J
Recent advances on metal nitride materials as emerging electrochemical sensors: A mini review
Full text linkMetal nitride materials are garnering interest in many fields including electrochemistry, although they are still at an early stage of investigation and underexplored. This mini review provides insights on the latest advancements in the field of electroanalytical chemistry based on metal nitride materials, specifically focusing on the best performing transition metal nitride sensors published between 2017 and 2020 for important targets such as glucose, hydrogen peroxide and dissolved oxygen. Nickel cobalt nitride electrodes demonstrate electrocatalytic behaviours toward glucose oxidation and hydrogen peroxide reduction processes. Meanwhile, zirconium nitride electrodes could replace platinum/carbon electrodes for oxygen reduction reaction. This article also introduces solid molybdenum nitride microdisk electrodes, which can easily be prepared and maintained and show diffusion-control voltammetric responses for the complex peroxodisulfate reduction reaction. This mini review will benefit researchers who would like to delve into the potential of metal nitride electrodes as electrochemical sensors.</p
Qualitative and quantitative methods of Capsaicinoids: a mini‑review
Full text linkThe interest in capsaicinoids increased recently due to its potential for commercial use, including food products, dietary supplements, pharmaceutical, and self-defence products. Hence, there is an urge to develop an efficient qualitative and quantitative method of capsaicinoids so as to protect the consumer right and upright the regulation regarding their concentration in the aforementioned products. Therefore, this mini-review is aimed at assisting readers in choosing the best analytical method for detecting capsaicinoids in a variety of samples, which includes selected recent journals. HPLC, NMR spectroscopy, and electrochemical sensors are among the analytical methods chosen in this review. The advantages, disadvantages, and limitations of each analytical method are thoroughly examined. It also discusses the validation methods such as the accuracy, precision, sensitivity, selectivity, and detection limits of the techniques. This mini-review is believed to benefit not only researchers, but also the related regulatory institutions in the determination of capsaicinoids
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
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