1,720,959 research outputs found
Synthesis and characterization of some new metals complexes of ((2-Chloro acetyl) carbamothioyl) glycine
Get PDFA new ligand ((2-Choroacetyl) carbamothioyl ) Glycine (CCG) is synthesized by reaction of (Chloro acetyl isothiocyanate) with Glycine (1:1). It is characterized by micro elemental analysis (C.H.N.S.), FT-IR, (UV-Vis) and 1H and 13CNMR spectra. Some metals ions complexes of this ligand were prepared and characterized byFT-IR,UV-Visible spectra ,conductivity measurements, magnetic susceptibility and atomic absorption. From results obtained, the following formula [M(CCG)2] where M2+ = Mn, Co, Ni, Cu, Zn, , Cd and Hg, the proposed molecular structure for these complexes as tetrahedral geometry, except copper complex is has square planer geometry
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
Synthesis and spectroscopic study of new ligand 3-(acetylthioureido)propanoic acid with their metal complexes
Get PDFA new ligand 3-(3-acetylthioureido)propanoic acid (ATA) was prepared through the reaction of acetyl chloride, ammonium thiocyanate and b- alanine. For this study the following methods were used: FT-IR, 1H-NMR 13C-NMR spectra and the Elemental analysis. complexesis of M+2=Mn,Cu,Ni,Co,Zn,Cd and Hg derived from3-(3-acetylthioureido) propanoic acid have been synthesized and characterized by elemental analyses, molar conductance, magnetic suscpility, FT-IR, UV Vis spectra, The results have shown complexation with b-alanine derivative with metal ion in a 1:2 ratio. The spectral characterization confirms the formation of ligand and complexes. The evidences from the above results suggest the ligand to be abi dentate ion
Synthesis and Characterization of Some Metal Complexes of [4-Methoxy-N-(pyrimidine-2-ylcarbamothioyl)benzamide]
Get PDFA new ligand [4-Methoxy -N-(pyrimidine-2-ylcarbamothioyl) benzamide] (MPB) was synthesized by reactioniofi(4-Methoxyibenzoyliisothiocyanate)withi(2-aminopyri-midine). The Ligand was characterized by elemental micro analysis (C.H.N.S),(FT-IR) (UV- Vis) and (1Hi,13CNMR)spectra. Some transition metals complexes of this ligand were prepared and characterized by (FT-IR, UV-Vis) spectra conductivity measurements magnetic susceptibility and atomic absorption. From the obtained results the molecular formula of all complexes was suggested to be [M(MPB)2Cl2] (M+2i=Cu, Mn, Co ,Ni ,Zn ,Cd and Hg),the proposed geometrical structure for all complexes was an octahedral
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
Preparation, Identification And Biological Activity Of Some Metals Complexes With A New Ligand (4-Nitro-N-((6-Oxo-6,9-Dihydro-1H-Purin-2-Yl)Carbamothioyl)Benzamid)
Get PDFThis study aimed to synthesize and characterize a novel guanine derivative, namely ( 4-nitro-N-((6-oxo-6,9-dihydro-1H-purin-2-yl)carbamothioyl)benzamid) (abbreviated as NPBL4). This compound possesses an intriguing chemical structure, consisting of a guanine moiety (a bicyclic heterocyclic base) linked to a benzamide group through a carbamothioyl linker. The synthesis of this nitrogenous base derivative involved two steps. Firstly 4-nitro-N-thioformylbenzamide was synthesized by reacting 4-nitrobenzoyl chloride with ammonium thiocyanate in acetone. Subsequently, the obtained 4-nitro-N-thioformylbenzamide was reacted with guanine to yield the desired ligand. In addition to the ligand synthesis, the study focused on preparing complexes of various metal ions (Mn+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2, and Pd+2) with the prepared guanine derivative. The ligand and complexes were subjected to comprehensive characterization using techniques such as infrared spectra, ultraviolet-visible spectra, 1H-NMR, 13C-NMR spectra, elemental analysis (C.H.N.S.), molar conductivity measurement, magnetic susceptibility, atomic absorption, melting point determination, and study the biological activity for the complexes. The results of these characterization studies led to the determination of the general formulas for the prepared complexes, which were found to be [MCl2(NPB)2], where M represents the respective metal ion (Mn+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2, and Pd+2). Notably, the geometric shape of all the prepared complexes was determined to be an octahedron. In summary, this study successfully synthesized and characterized a novel guanine derivative (NPB) and investigated its complexes with various metal ions. The findings provided valuable insights into the chemical properties and structural features of these compounds
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