1,720,968 research outputs found
Application of fuzzy logic to assess the risk of accidental releases of ecotoxic substances in major hazard plants
No full textInclusion of Human Factor into Risk Assessment through a Fuzzy Frequency Modifier
No full textThe frequency of an accident’s occurrence is a key aspect to take into consideration in the field of risk assessment. Aspects such as the human factor, which is a major cause of undesired events in process industries, are usually not considered explicitly in the frequency estimation, mainly due to the uncertainty and complexity associated to them. Failure frequencies are modified by a fuzzy modifier that has been developed in order to introduce the human factor in their estimation. The model includes variables such as Organizational Factors, Job Characteristics Factor and Personal Characteristics Factor. Applying this methodology, new values of frequencies have been obtained. To develop the fuzzy modifier the opinion of experts has been taken into account through the completion of a questionnaire. The new values are considered more realistic and accurate since the human factor is now reflected. Consequently, this improves the final risk assessment when it is applied to techniques such as QRA (Quantitative Risk Analysis). In this study, a real chemical installation, which stores flammable products, was examined using QRA and the fuzzy modifier. The introduction of the human factor through the fuzzy frequency modifier provided more conservative results than those obtained without considering this facto
Preliminary risk assessment of ecotoxic substances accidental releases in major risk installations through fuzzy logic
Full text linkIn the present work a fuzzy logic model to preliminary assess the risk of accidental releases of ecotoxic substances in hazard plants has been developed. The methodology is based in three steps, the characterization of the hazardousness of the substance, the delimitation of the soil and groundwater vulnerability and the identification of the protective and preventive measures of the plant. The tool has been tested with a set of storage yards of ecotoxic substances, mainly oil, in the Regione Piemonte area (Italy). The results obtained are in good agreement with the real situation of the surveyed storage yards. Thus, by using this methodology it is possible to preliminary assess the risk from uncertain data.Peer ReviewedPostprint (published version
Environmental fate models
No full textThe environmental fate of chemicals describes the processes by which chemicals move and are transformed in the environment. Environmental fate processes that should be addressed include: persistence in air, water, and soil; reactivity and degradation; migration in groundwater; removal from effluents by standard waste water treatment methods; and bioaccumulation in aquatic or terrestrial organisms. Environmental fate models are by no means compulsory for managing priority substances. Efficient source control can be done without them, i.e. by reducing emissions gradually and monitoring the environment to track changes. However the environmental fate models are proposed for use for two main reasons: (i) because the quantitative models can improve the understanding of the managed system and (ii) because the models can be used to predict long term impacts of planned actions. Furthermore the residence times of some of the priority substances may be very long (e.g. 50 years for mercury in water column), therefore only monitoring can be not enough to detect if the taken measures are enough to reach the good ecological status. The use of environmental fate models in decision making is not a new concept. They are routinely used in the framework of environmental risk assessment. The output of environmental fate models can be expressed as time series of predicted concentrations in different medium of both indoor and outdoor environments
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
Human and Environmental Impact Producted by E-waste Releases at Guiyu Region (China)
No full textOver the last decades, the amount of electronic waste (e-waste) has increased rapidly in the world. It
has become one of the emerging problems of the twenty-first century. About 50–80% of e-waste from
industrialized countries is exported to recycling centers in developing countries such as China, India,
Pakistan, and the Philippines because of the lower wages for labor and less strict environmental and
safety regulations in these countries. China, however, due to its size and population not only receives
enormous quantities of used devices from developed countries but also generates tremendous amounts
of domestic e-waste due to its fast consumption rates of electrical and electronic (EE) products. Guiyu,
a town in the Guangdong Province in the southeast of China, was identified as the largest e-waste site
in the world and the second most polluted spot, due to informal recycling processes (acid extraction for
metals, open burning of wires to get copper), which release chemicals to the environment, representing a
threat to human health, both to “recyclers” and to nearby citizens, and the environment. Measured data on
environmental concentrations and human health are scarce and scattered. Hence, environmental modeling
was applied in order to generate an overview over the distribution of selected hazardous substances due
to informal recycling in Guiyu. As all available models have a specific focus and various pros and cons,
four models were chosen, which cover different geographical scales and address different environmental
compartments and objectives in order to assess the potential risk of the selected chemicals to humans and
the environment.
These models have been applied to different scenarios, mainly for two chemicals, decabromodiphenyl
ether (DeBDE) and lead (Pb). Emissions of DeBDE and Pb that represent the input to the models are based
on the SFA (Substance Flow Analysis) developed for Guiyu presented in the chapter “Tracking Global
Flows of E-Waste Additives by Using Substance Flow Analysis, With a Case Study in China.” In this
chapter the results of the four models are presented and compared among them. The impact of the selected
chemicals for the environment and human health at Guiyu region has been assessed on different scales, i.e.,
on a global, regional, and local scales
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
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