1,721,028 research outputs found
Comparison of quay wall designs in concrete, steel, wood and composites with regard to the CO2-emission and the Life Cycle Analysis
No full textThis thesis focuses on quay wall structures in the Port of Rotterdam. A quay wall is a soil retaining structure where ships can moore and transfer goods. Over the centuries the developments in quay wall structures have been tremendous, due to increasing ship dimensions, loads and crane designs. Next to that climate change is a hot topic nowadays. The building sector is one of the sectors which have a large impact on the environment. Constructing durable and sustainable throughout the entire life cycle is becoming more and more important. CO2-emission is a widely excepted parameter to estimate sustainability. Besides CO2 many other environmental effects, so called impact categories, have an impact on air, water and soil, which can be shown with help of a Life Cycle Analysis (LCA). In this thesis the impact on the environment of a quay wall constructed in four different materials is analyzed. These materials are: concrete, steel, wood and composites. To make a good comparison, the designs must be based on the same requirements and boundary conditions. For this purpose the quay wall of the Euromax Terminal is used. Several types of quay wall structures have been studied and their main dimensions have been determined. This resulted in a retaining wall in combination with a concrete L-shaped relieving structure. The stability of the structure is guaranteed by a combination of mv-piles and vibro-piles. In this design the retaining wall is constructed in the four different materials: concrete diaphragm wall, steel combi wall, wooden wall of Azobé elements and a Fiber Reinforced Polymer sandwich panel. Next a cost estimation of the four designs has been made. Finally the CO2-emission of each structure is determined. This Carbon Footprint has been calculated with two different databases. Furthermore the emissions of several other impact categories have been determined. They represent emissions due to pollution to air, water and soil, depletion and land use. Using monetization as a weighing factor, the so called “shadow prices” of each structure can be calculated. These costs represent the costs for the preventive measures that must be taken to reduce the emissions to a sustainable level.CoMEM - Coastal and Marine Engineering and ManagementHydraulic EngineeringCivil Engineering and Geoscience
Joint-free quay walls in high performance concrete: A feasibility study
No full textA feasibility study has been started with respect to the joint-free exectution of quay walls in high-performance concrete. This feasibility study has the purpose of looking for faster means of building quay walls. The use of high performance concrete is an excellent material for a faster execution of the superstructure of quay walls. The strength development of the material is significantly higher then normal concrete, which allows for faster dismantling of the casing. To further improve the building speed it's been proposed to broaden the study with the subject of joint-free execution. This means there will be no contraction joints anymore in the concrete upper structure of the quay walls, which allows for a continuous execution of the superstructure. As a reference project the quay wall of ECT (Europe Container Terminal) has been chosen. A reference project is chosen to allow for a comparison between the new and the old design. The superstructure has been redesigned in high performance concrete without the use of contraction joints. The substructure stayed the same to allow for a comparison between only the superstructures. The first problem faced was the temperature induced deformation of the superstructure. The foundation (the substructure) was unable to withstand these new forces, causing them to fail in certain cases. The main item here was the increased length of the quay wall when the concrete got warmer. To disable the influence of the elongation of the superstructure with respect to the loads on the substructure a slide bearing has been designed between the superstructure and the substructure. This allows the superstructure to elongate without causing any harmful loads on the substructure. The only adjustment in the design was the relocation of the strain element (the MV-pole) from the superstructure to the substructure. Furthermore the superstructure has to be made from fibre-reinforced concrete. This has to be done to make the concrete strong enough to withstand the extra strains, caused by the joint free execution. When at the end the two designs (the old one and the new one) were compared it showed a slight profit for the new design of 200.000 euro. Compared to the overall costs of 24 Million euro of the project this was a small profit. More economical profit could be gained when the used concrete mixtures will be cheaper. The price of the concrete made up for a large proportion of the loss-factor, so cheaper concrete would increase the overall profit significantly.Civil Engineering and Geoscience
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
Voegloze Kademuren in Hogesterktebeton
No full textOm een beter inzicht te krijgen naar de toepassingen van hogesterktebeton (HSB) bij de uitvoering van kademuren is er een haalbaarheidsstudie gestart. Deze bekijkt de mogelijkheden van het voegloos uitvoeren van de betonnen bovenbouw van kademuren in HSB. Als eerste is er gekeken naar de opbouw van kademuren. De verschillende onderdelen waaruit een kademuur is opgebouwd zijn geanalyseerd en ingedeeld naar functie. Er zijn een aantal verschillende typen kademuren genomen en er is gekeken voor welk type kademuur het aantrekkelijk zou zijn om deze uit te voeren in HSB.WaterbouwkundeCivil Engineering and Geoscience
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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