1,720,965 research outputs found
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Physical and electrochemical studies on nanocomposite -30 % PMMA-g-natural rubber (MG30) / Nurul Ilham Adam
No full textThis thesis focuses on the effect of nanofillers on the physical and electrochemical properties of polymer electrolytes. 30% PMMA-g-natural rubber (MG30) is doped with lithium triflate (LiTf) salt and composited with silicon dioxide (SiO₂) or aluminum oxide (A1₂O₃ ) nanofiller. The conductivity of the samples is measured by impedance spectroscopy (IS) and shows a substantial increase in conductivity with the addition of lithium salt up to 35 wt. % after which, at higher salt loading (>35 wt.%) the conductivity seem to decrease. The optimum composition of MG30-LiTf salt complexes sample with highest conductivity is then separately composited with different concentrations of SiO₂ or A1₂O₃ filler
Physical and electrochemical studies of bio-based chain extended cationic polyurethane with NaTf salt for solid polymer electrolytes / Nurul Ilham Adam
Full text linkPolymer electrolytes are class of materials characterised with high ion concentrations in application of renewable energy devices. Unfortunately, the world is facing a severe shortage of renewable, safe, and environmentally friendly energy resources. Therefore, in this study, a new class of bio-based chain extended polyurethane (modified PU) and cationic polyurethane (PCPU) were synthesized as a polymer host for polymer electrolyte system. The PU samples were synthesized using two different polyols monomer groups ratio of palm kernel oil polyol (PKO-p) to polyethylene glycol (PEG200) as chain extender, while 2-4 'diphenylethylene diisocyanate (MDI) is used as isocyanate group. 1-iodopropane is used as alkyl group to produce cationic PU (PCPU) and sodium triflate (NaTf) is used as a doping salt for preparation of polymer electrolyte. Characterization techniques of GPC, FTIR, XRD, FESEM, TGA, DSC, EIS, transference number (ionic and cationic) and linear sweep voltammetry (LSV) were used to study the properties of the prepared system. The addition of PEG200 into PU increased the molecular weight of modified PU from 14968 g/mol to 66969 g/mol and decreased to 2157 g/mol in PCPU. Formation of urethane linkages (-NCOOH-) of PU were evidenced by Fourier transform infrared (FTIR) spectroscopic analysis with the disappearance of NCO peak and emergence of secondary amine, carbonyl, and ether group. XRD studies showed that the sample PU3 exhibited the largest FWHM at 9.83 with degree of crystallinity of 68 % and for PCPU3, FWHM value is at 9.68 with degree of crystallinity of 68 %. The Tg reduced to 35 ºC for PU3 and 23 ºC for PCPU3 with thermal stability up to up 190 ºC. The ionic conductivity achieved was approximately 1.46 × 10-9 Scm-1 for PU3 and 2.97 × 10-9 Scm-1 for PCPU3. The addition of 25 wt. % NaTf in PU3 and PCPU3 polymeric system found that the peaks of the functional groups N-H, C=O, C-N and C-O-C were shifted due to the interaction of Na+ with oxygen atom at ether group. TGA analysis proved that all samples prepared are thermally stable up to 190 º C and the Tg was found to decreased. Ionic conductivity for the PU and cationic PU polymer electrolytes showed optimum ionic conductivity at 25 wt.% NaTf of 3.59 ×10 -7 Scm-1 for PU3_25 and 1.11 × 10-5 Scm-1 for PCPU3_25. The transference number of these electrolytes were found to be 0.40 for PU3_25 and 0.47 for PCPU3_25 with window stability of 2.90 V for PU3_25 and 3.01 V for PCPU3_25
The effect of current density on nanostructured porous silicon / Nurul Ilham Adam
Full text linkThe work presents the effect of the current density on nano-structured porous silicon through the electrochemical etching process using Hydrofluoric acid (HF) and Ethanol (CH2OH) at ratio 1:1. In this research, the current density is increased during the anodization process regarding the etching time and the distance of the electrode are constant. Atomic Force Microscope (AFM) measurement and Photoluminescence Spectrometer (PL) analysis were performed to investigate the physical and the optical characteristics of the interface region of porous silicon. The result shows that the roughness of the porous silicon surface was increased when the current density increased. The PL measurement indicates that the PL intensity and the Photon energy increased with the increasing value of current density. This research discovers that the current density has large effect on the nanostructured porous silicon on the structural and optical properties
Interaksi dinamik antara ilmu fizik dan sukan/ Nurul Ilham Adam
Full text linkIlmu Fizik dan sukan dikaitkan secara intrinsik, dengan prinsip saintifik yang penting dalam menentukan hasil pelbagai aktiviti sukan. Artikel ini akan memperjelaskan hubungan dinamik antara ilmu Fizik dan sukan berlandaskan hukum gerakan dalam konsep tenaga dan biomekanik.Teori Hukum gerakan Newton oleh Sir Isaac Newton pada abad ke-17, adalah asas untuk memahami ilmu fizik dan gerakan dalam sukan. Hukum ini dikenali sebagai hukum inersia, dimana objek dalam keadaan diam (tidak bergerak) akan kekal dalam keadaan diam. Manakala objek yang bergerak akan terus bergerak pada halaju malar jika tiada tindakan oleh daya luar. Para atlet mempraktikkan hukum ini dalam pelbagai sukan contohnya dalam acara trek padang, di mana pelari pecut memecut dengan mengerahkan seluruh tenaga secara maksimum untuk mengatasi inersia dari garisan permulaan
- …
