105,075 research outputs found
Future of weir Linne
No full textThe Meuse in the Netherlands is since the 1920s dammed by 7 weirs, which are located near Borgharen, Linne, Roermond, Belfeld, Sambeek, Grave and Lith. The weirs regulate the water levels in the canal sections (=stuwpanden) to provide sufficient depth for navigation. The management of the weirs is regulated by water level measurements at Maastricht St. Pieter (formerly Borgharen). The weirs dam the river for discharges lower than 1200 m3/s. For higher discharges the weirs are completely opened. Weir Linne is the oldest weir of the canalized Meuse and is part of the smallest canal section (=kanaalpand) of the Meuse. The weir consists just like the weirs of Roermond, Belfeld and Sambeek of two parts, a rough discharge regulating Poirée part and a accurate regulating Stoney part. Weir Linne maintains a water level of 20.80 m +NAP in the upper canal section. The canal section forms a navigable interchange between the Juliana Kanaal, Lateraal Kanaal, Kanaal Wessem-Nederweert and canal section Roermond. The weirs in the Dutch part of the Meuse have been constructed for a period between 80 and 100 years. The weirs are approaching the end of their lifetime in the period between 2020 and 2030. In this situation is not spoken about design lifetime because in the period when the weirs were constructed the design lifetime was not defined. Based on maintenance reports and inspections it is concluded that the weirs are not able to fulfill their functions properly, they need to be replaced or upgraded. The main reasons for replacement or upgrading are technical and functional aging and changing legislations. According to Rijkswaterstaat the weir of Linne has ended its lifespan in the year 2030. Aging of materials and changes in the ARBO legislations are issues of the weir. This conclusions is the result of inspections and analyzes over several years. Besides aging of materials also aging in functionality contributes to the decrease of the weir quality. The functionality of the weirs has been changed in time due to changing conditions, in the RINK project called "new risks". These functional changes can have their causes in changes of design assumptions, maintenance, usability and controllability or law and regulations. The weir of Linne has to deal with the risks of changing discharges, ASR degradation, operability and the weir does not meet the ARBO regulations. This graduation report is focused on the problems of weir of Linne. The aim of this thesis research is to improve the situation of weir Linne for the future situation by replacing of upgrading the weir. The weir should meet the requirements based on discharge and navigational purposes in the future. This report is made up at four scale levels, the problem is approached from a high scale level to lower scale levels. The levels are made up according to the elementary design cycle. The first scale level concerns the canalized Meuse in the Netherlands. Because canal section Linne is relatively small It is investigated if it is possible to remove weir Linne instead of renewing or upgrading of the weir. The second scale level focuses on canal section Linne. In this section the effect of the Maasplassen with respect to the water level changes of the canal section is investigated for high and low discharges. Also the effect of the water level changes to the weir management is investigated to obtain a clear view about the reaction time of weir operations with regard to opening and closure of the weir. The third design level concerns the construction of weir Linne. It is considered if according to the RINK reports the current weir construction should be renewed or upgraded. The chapter proceeds with a rough analysis about the required width and retaining height of the weir to obtain if the discharge capacity of the current weir is sufficient for the future. It is decided to upgrade the Poirée part of the weir, the last part of this design level concerns the determination of a new gate type for the Poirée part of the weir. The lowest design level is focusing on the design of the new weir gate. The gate is designed in high strength concrete. The dimensions of the gate elements are determined and the gate is checked to the requirements according to Eurocode 2. The last section of the lowest design level concerns the way of placing and connecting the new gate to the current construction. The result of the first design level is that abolishing canal section Linne by combining the canal section with the upstream or downstream canal sections is not advisable. Weir and weir section Linne should be maintained in the future. This hold also for the other canal sections of the Meuse corridor except for canal section Lith. Because this canal section is the most downstream section in the Meuse canalization and far away from Linne, interventions to this canal section would have no effect on weir and canal section Linne. However the result holds for the current layout of the Meuse corridor. If a new layout should be proposed for the canalization of the Meuse it should be analyzed if weir Linne should be maintained or removed. The Maasplassen have a damping effect on the water level changes in canal section Linne. The damping effect is the effect of the relation between the changing discharge with respect to the water level changes in the canal section. Due to the Maasplassen the water level changes develop more slowly compared to a situation without the Maasplassen. This is the result of the storage capacity of the Maasplassen. The damping effect of the Maasplassen is most preferable and effective during low discharges. Navigational dept is maintained for a longer period because the water level decrease proceeds slowly due to the connected lakes. The discharge accuracy of the weir is not sufficient for the small discharges in the future, to maintain the navigable depth during low discharges the discharge accuracy should be increased. The damping has less effect on extreme high discharges compared to low discharges. Because the canal section is relatively small the water level rise will be relatively quick regardless of the damping effect of the Maasplassen. An increase of the storage capacity of the Maasplassen has a minor influence on this effect. However, the banks and retention areas are omitted in the analysis of the effects of the Maasplassen to the water level changes in canal section Linne. The results are not exact however, relative to each other the variants do represent a clear view about the effect of the Maasplassen to the water level changes. The opening procedure shorter than 8 hours is reliable after high discharges are measured at measure point Maastricht St. Pieter. Investigations on running times of flood waves on the Meuse have been done are not valid any more. Due to the Grensmaasproject running times for food waves will change. It is not advisable according to the RINK (=Risico Inventarisatie Natte Kunstwerken) report to replace the total weir of Linne at the moment. It is advised to monitor the condition of the weir until the period 2030 - 2035 and to take after this period a final decision. After this period a decision should be made to replace the or maintain the current weir for a longer period. In this report is concluded to maintain the current weir construction instead constructing a new weir. Due to over dimensioning the concrete super construction is a robust construction. The upgrade of the current weir will be done by the removal of the Poirée gates and constructing a new gate on the old Poirée part. The Poirée gate does not meet the requirements according to the ARBO legislations and the gate is not able to be remote controlled. The new type of weir that is chose to replace the old Poirée gates is the inflatable flap gate. The flap gate is able to retain a the required water level, able to close the old Poirée part without large reconstruction of the weir. The gate fulfills (when properly designed) the ARBO legislations and is able to be remote controlled. The flap gate is designed in concrete class C90/105, this is a high strength concrete. High strength concrete is a durable construction material and requires less maintenance compared to steel constructions, especially in wet environments. The gate will be supported three air filled bladders, the bladders are placed next to each other. The concrete construction meets the requirements according to Eurocode 2. The checks of reinforcement, cracks and moment of failure are done for bending moments and shear resulting of loads perpendicular to the gate. Torsion due to for example failure of bladders is not taken into account. Checks to the concrete gate with regard to moments, cracks and failure due to torsion moments are also not taken into account. The gate will be placed as a prefabricated element. The element contains the gate, bladder, chain and supporting bottom plate. The plate is on upstream side placed at the rotation notches of the former Poirée gates and on the downstream side to the weir bottom. The gate could be further optimized, optimization could be done by for example reducing of the gate weight and curving the gate to increase the discharge capacity.Hydraulic StructuresHydraulic EngineeringCivil Engineering and Geoscience
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Study on the effect of polysaccharides from Solanum nigrum linne on cellular immune function in tumour-bearing mice
No full textWe investigated the anti-tumour effect of polysaccharides from Solanum nigrum Linne, and its relationship with the immune function of tumour-bearing organisms. MTT assay was used to observe the effect of different doses of polysaccharides from Solanum nigrum Linne on proliferation of lymphocytes in tumour-bearing mice. ELISA assay was also used to detect the levels of IL-2 in mice, and a laser scanning confocal microscope was used to detect the effect of polysaccharides from Solanum nigrum Linne on intralymphocytic free calcium ion concentration in tumour-bearing mice.Different doses of polysaccharides from Solanum nigrum Linne significantly inhibited the growth of mouse H22 solid tumours, improved the survival time of tumour-bearing mice, increased the proliferation of lymphocytes, elevated the levels of IL-2, and increased the concentration of calcium ions in the lymphocytes. Polysaccharides from Solanum nigrum Linne have certain anti-tumour effect, which is related with the cellular immune function that regulates the body.Keywords: Solanum nigrum polysaccharides; tumour-bearing mice; cellular immunit
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
No full textWe 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
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
Flexicurity im Lebenslauf Wechselwirkungen zwischen pluralen Lebensformen und betrieblichen Beschäftungsstrategien
No full textDiewald M, Brose H-G, Gödicke A. Flexicurity im Lebenslauf Wechselwirkungen zwischen pluralen Lebensformen und betrieblichen Beschäftungsstrategien. In: Kronauer M, Linne G, eds. Flexicurity. Die Suche nach der Sicherheit in der Flexibilität. Forschung aus der Hans-Böckler-Stiftung. Vol 65. Berlin: edition sigma; 2005: 223-248
Contribution of Information and Communication Technology (ICT) in Country’S H-Index
No full textThe aim of this study is to examine the effect of Information and Communication Technology (ICT) development on country’s scientific ranking as measured by H-index. Moreover, this study applies ICT development sub-indices including ICT Use, ICT Access and ICT skill to find the distinct effect of these sub-indices on country’s H-index. To this purpose, required data for the panel of 14 Middle East countries over the period 1995 to 2009 is collected. Findings of the current study show that ICT development increases the H-index of the sample countries. The results also indicate that ICT Use and ICT Skill sub-indices positively contribute to higher H-index but the effect of ICT access on country’s H-index is not clear
Fully Turbulent Mean Velocity Profile for Purely Viscous non-Newtonian Fluids
No full textThe characteristic near wall behavior of turbulent flow of purely-viscous non-Newtonian fluids is discussed for both power-law (P.-L.) and Herschel-Bulkley (H.-B.) rheological models. A proper scaling is presented for H.-B. fluids to establish an analogy with power-law fluids with same flow index. To provide reference data for turbulent flow of non-Newtonian fluids, DNS simulations of power-law fluids are conducted in a rectangular channel for a large range of power-law indices ( = 0.5, 0.69, 0.75, 0.9, 1, 1.2). The DNS data show that the mean velocity profile in the viscous and logarithmic layers follow expressions of the form and respectively, where shows a logarithmic dependency on the flow index.Comparison with some experimental data shows the above formulation to be valid for Reynolds numbers (based on shear velocity) as high as 1000
H-index and research evaluation: A suggested set of components for developing a comprehensive author-level index
No full textThe H-index has been investigated in various studies; this index has many strengths that have made it popular. However, it also has weaknesses, due to which other indicators have been developed. This study aims to identify the strengths and weaknesses of the H-index and provide the minimum set of necessary components for developing a comprehensive author-level index. In this systematic literature review, Scopus, PubMed, Web of Science, Emerald, and ProQuest databases were searched to identify relevant studies. From the number of 14,253 retrieved studies, after two stages of screening, 81 studies were selected according to the eligibility criteria for data extraction. The findings of the study led to the identification of 15 strengths in the three categories of Quality Features, Simplicity, and Suitability, and 13 weaknesses in the six categories of Publications, Citations, Academic Age, Author Credit Allocation, Variety of Fields, and mathematical calculation for H-index. Finally, 28 components were identified as the minimum set of necessary components to develop a comprehensive author-level index to help evaluate researchers more realistically and fairly. The minimum components that need to be considered in developing a comprehensive author-level index can be proposed as follows: Quality Features, Simplicity, Suitability, Publications, Citations, Academic Age, Author Credit Allocation, Variety of Fields, and mathematical calculation
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