1,722,035 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
The Influence of Heat Treatment and Weathering on the Gasification Reactivity of Montana Lignite
No full textThermogravimetric analysis and temperature programmed desorption have been used to assess the influence of annealing and of char weathering on the gasification reactivity of a Montana lignite. To this end, lignite samples were heat treated at 900 °C for different times in a nitrogen atmosphere. Samples either weathered under ambient conditions for six months or nonweathered were tested to assess their reactivity toward oxygen and carbon dioxide and their propensity to chemisorb either reactants. Reactivity and chemisorption capacity of heat-treated chars were found to be closely related to each other. Annealing mainly affects the availability of sites that are active toward oxygen chemisorption, a property that is directly reflected by char oxyreactivity. Also, the effect of weathering is strongly emphasized by the previous temperature history of the chars. On the contrary, the ability of chars to chemisorb carbon dioxide and related gasification reactivity are negligibly affected by heat treatment. Results are analyzed considering possible relationships between the reactivity, chemisorption capacity, and chemical and microstructural modifications induced by heat treatment in low-rank coals. It is believed that modifications of the organic structure, rather than mineral matter transformations, are responsible for the observed phenomena
Polarization Modulator Unit Harness Thermal Design for the Mid- and High-Frequency Telescopes of the LiteBIRD Space Mission
No full textPolarization modulator units (PMUs) represent a critical and powerful component in CMB polarization experiments to suppress the 1/f noise component and mitigate systematic uncertainties induced by detector gain drifts and beam asymmetries. The LiteBIRD mission (expected launch in the late 2020 s) will be equipped with 3 PMUs, one for each of the 3 telescopes, and aims at detecting the primordial gravitational waves with a sensitivity of δr< 0.001. Each PMU is based on a continuously rotating transmissive half-wave plate held by a superconducting magnetic bearing in the 5 K environment. To achieve and monitor the rotation a number of subsystems is needed: clamp and release system and motor coils for the rotation; optical encoder, capacitive, Hall and temperature sensors to monitor its dynamic stability. In this contribution, we present a preliminary thermal design of the harness configuration for the PMUs of the mid- and high- frequency telescopes. The design is based on both the stringent system constraint for the total thermal budget available for the PMUs (≲ 4 mW at 5 K) and on the requirements for different subsystem: coils currents (up to 10 mA), optical fibers for encoder readout, 25 MHz bias signal for temperature and levitation monitors
SIVRAD: an integrated system for the assessment of the environmental risk from solid waste landfills - Guidelines/ SIVRAD: Un Sistema Integrato per la Valutazione del Rischio Ambientale da Discariche - Linee guida
No full textLa contaminazione delle risorse idriche sotterranee a causa di una fuoriuscita di percolato da discarica ha creato gravi problemi socio-economici ed ambientale in diversi paesi. Infatti, molte delle discariche esistenti e quelle abbandonate, ancorché non adeguatamente controllate o gestite, possono costituire una grave problematica sanitaria ed ambientale. La scelta del sito per lo smaltimento dei rifiuti deve necessariamente scaturire da uno studio rigoroso basato sulla valutazione integrata della pericolosità ambientale dell’impianto stesso, delle caratteristiche
idrogeologiche e del grado di vulnerabilità intrinseca all’inquinamento delle falde acquifere.
Nel presente lavoro viene proposto un Sistema Integrato per la Valutazione del Rischio Ambientale da Discariche di rifiuti solidi urbani (SIVRAD). L’analisi integrata della vulnerabilità intrinseca del sistema acquifero e la stima della pericolosità potenziale intrinseca consentono di valutare l’idoneità dei siti ad ospitare una discarica e di definire la priorità di bonifica ed il sistema di monitoraggio per gli impianti esistenti. Inoltre, per le nuove discariche, la metodologia descritta permette di suggerire una migliore strategia di costruzione per la tutela dell’ambiente circostante.
Infine, questo approccio metodologico è stato applicato in discariche situate in diversi contesti geologici ed idrogeologici.In recent years, the contamination of the underground resources from landfill leachates is recognised as a serious socio-economic and environmental problem in many countries. In fact, the existing not adequately controlled and abandoned sites, constitute a serious sanitary and environmental problems. The choice of the waste disposal site must necessarily arise from a rigorous study based on the joint assessment of the environmental hazard of the same plant and the hydrogeological characteristics and the degree of intrinsic vulnerability to pollution of the aquifers. In the present paper an integrated system for the assessment of the environmental risk from solid waste landfills is proposed. The integrated analysis of the intrinsic vulnerability of the aquifer system and the estimate of the intrinsic potential hazard caused by the landfill expressed in terms of danger index allow to evaluate the suitability of the sites to host a landfill and to define the reclamation priority and monitoring system for the existing landfills. As concerns new landfills, the proposed methodology could also support a better construction strategy and the protection of the surrounding environment. Finally, this methodological approach was applied in landfills located in different geological and hydrogeological contexts
- …
