1,720,965 research outputs found
Covering plastic films in greenhouses system: A GIS-based model to improve post use suistainable management
Full text linkYearly, in Europe, more than 1 million tonnes of plastic materials are used in agricultural activities. Among the
possible applications, plastic films for protected cultivation practices are highly used worldwide because of the
significant advantage deriving from the shortening of the growing period. However, in the absence of a correct
policy disposal of plastic films, environmental degradation could take place with serious ecological and economic
consequences.
In this study, a geographical information system (GIS) - based model to locate and quantify the yearly amount
of agricultural plastic waste (APW) coming from crop-shelter coverage used in greenhouses system was put
forward and was applied in a study area located in southern Italy, highly characterised by protected cultivation
practices.
Firstly, the areas with the highest density of crop shelters were mapped, then a suitable index to determine
APW amount was computed and applied to obtain heat maps related to covering plastic films. Finally, sensitivity
analyses were carried out by varying thickness, lifetime, and density of the covering films of the greenhouses,
located in the considered samples. The index ranged between 976 kg ha� 1yr� 1and, 2484 kg ha� 1yr� 1.
The results showed that the density of greenhouses and tunnels-greenhouses is still elevated nearby the
coastline, highlighting that the guidelines of the territorial plan of the Province of Ragusa concerning the
displacement of protected crops from the coast to the internal rural areas were disregarded. Moreover, the GIS-
based model results could provide basic information for the analysis of the environmental impact due to
transportation of APW. Therefore, these results could offer a suitable tool to improve the correct disposal
management of covering plastic films and the related recycle policy
GIS based-model to locate and quantify agricultural wastes for sustainable building components: Plastic films and sheep wool fibers
No full textNowadays, the interest for environmental sustainability, energy, and efficiency constructions, generally known as Green Buildings, it is strongly increasing. Procedures adopted for Green Buildings are often based on both the reduction of environmental impact of buildings and the improvement of human and animal wellness. This study stems from the need to reuse agricultural wastes (AW) for producing sustainable materials to be used for the construction or renovation of rural buildings. Since a sustainable reuse of AW depends on their availability and geographical location, a methodology was put forward to locate and quantify the wastes considered in this research study i.e., plastic films used for protected crops and sheep wool. By using a Geographical Information System (GIS), land use analysis was carried out in an area with the highest concentration of protected crops in Italy (Ragusa province). A suitable index for computing Agricultural Plastic Wastes (APW) was chosen from literature. Furthermore, by using data supplied by National Zootechnical Registry, a dedicated GIS model was developed to localize and quantify sheep and breeder's sheep in Sicily. This first part of the research provides basic information useful for planning tailored collection centers as near as possible to those areas where these wastes are highly produced by minimizing the environmental impact due their localizatio
Organized Framework of Main Possible Applications of Sheep Wool Fibers in Building Components
Full text linkGreasy sheep wool is currently considered a special waste for its high bacterial load, with expensive disposal costs for sheep breeders. For this reason, wool is often burned or buried, with serious consequences for the environment. On the other hand, sheep wool is well regarded as one of the most performative insulating natural fibers due to its thermo-hygrometric and acoustic properties. In the building sector, sheep wool meets the requirements of green building components because it is an eco-friendly material, there is a surplus of it, it is annually renewable, and totally recyclable. If used instead of common insulation materials (e.g., fiberglass, rock wool, polyurethane foam, polystyrene), sheep wool offers significant benefits for sustainability such as a reduction in the production costs for new insulating materials and in environmental pollution. Mechanical and physical properties of sheep wool investigated in previous studies were assessed and discussed with the aim of providing an organized framework of possible applications of wool fibers in building components. This paper highlights in detail aspects that have not yet been investigated enough to detect new potential uses of sheep wool fibers in rural buildings and the reuse of traditional ones
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
Spatial analysis to quantify and localise the residual cardoon stem fibres as potential bio-reinforcements for building materials
Full text linkToday in Europe building-sector is responsible for the 50% of air pollution and for 70% of waste production. For this reason, researchers’ interest is focused on new eco-building materials that are sustainable, with low impact, renewable and recyclable. In this context, in the last few years, the use of cellulose-based fibres as potential reinforcements for bio-composite materials, instead of synthetic one, received worldwide growing attention. Among natural fibres, both cellulose and protein-based ones, in literature it was found that, due to its mechanical properties, artichoke fibre is suitable for this use. In this study, a Geographical Information System (GIS)–based model to locate and quantify the yearly amount of agricultural waste coming from Cynara cardunculus L. (CW) cultivation was put forward and was applied in a study area located in Southern Italy. As an additional protein-based fibre, sheep wool fibre was also taken into account due to the high presence of sheep. The estimated available amount of both considered fibres was reported in a GIS map in order to show their distribution at territorial level. The achieved results could represent basic information for both sustainable locating collection centre and analysing the environmental impact related to the logistics and supply phase
Reuse of livestock waste for the reinforcement of rammed-earth materials: investigation on mechanical performances
Full text linkAgricultural wastes as an additive within raw earth materials could improve the mechanical and physical properties of new sustainable construction materials and enhance waste management from a circular economy perspective. This study intends to fill the lack of knowledge considering the mechanical effects of animal fibres on rammed-earth materials. The effects of livestock waste, i.e., sheep wool fibre (SWF), as a reinforcing element in building components produced using raw earth and lime-free mortars have been evaluated. The samples were made by varying the wool content (0.25% or 0.50% weight) and the length of the fibres (from 10 mm to 40 mm). Linear shrinkage, flexural strength, compressive strength, and frac- ture energy were evaluated on samples incorporating SWF, to assess the effects of this waste addition on the mechanical performances of new bio-composite material. The best result of the flexural strength was 1.06 MPa, exhibited by samples made with the longest and highest percentage of fibres, 40 mm, and 0.50%, respectively. The average compression strength was about 3.00 MPa. The average energy fracture of the composite was 806.38 (N/mm)
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
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