1,720,952 research outputs found
Berm breakwater structures: Results from analysis of 3D tests at DHI
No full textFigures with results from the tests; no text is attached.Berm Breakwater
Model tests carried out at Danish Hydraulic Institute (DHI)
No full textResults of physical tests done at DHI on the stability and regressionof Berm Breakwaters.Berm Breakwater
Web 2.0: Hypertext by Any Other Name?
No full textWeb 2.0 is the popular name of a new generation of Web applications, sites and companies that emphasis openness, community and interaction. Examples include technologies such as Blogs and Wikis, and sites such as Flickr. In this paper we compare these next generation tools to the aspirations of the early Hypertext pioneers to see if their aims have finally been realized
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Revealed likelihood and knightian uncertainty
Get PDFexpected utility theory;uncertainty;revealed preference
Metocean forecasting for ports and terminals
No full textIndustry standard numerical models are excellent and accurate tools for analysis of port plans and design. They link meteorological and oceanographic information to impacts on moored vessels and thereby provide the metocean conditions along the berths. By use of relevant motion and safety criteria for moored vessels, numerical modelling studies can assist the designer and the port owner to determine the optimal protection for the port operation. Operators and users of an exposed port or terminal will from time to time experience downtime due to adverse weather conditions. Downtime can be associated with strong currents in the approach channel and port entrance or with difficulties encountered for pilot assistance. It can also be due to excessive motions of the vessel resulting in suspension of loading/unloading by cranes or over ramps. If the port operator and the port user receive early information on conditions in and around the port and is able to interpret this information into expected conditions for arriving vessels they will be able to make prudent decisions on optimal and safe arrival at the port. This paper describes the use of numerical models and state-of-art-methods for ship motion analysis in combination with metocean forecast to build a web-based operational tool for vessels calling at ports and, terminal facilities. The systems present in a user friendly way the forecast exposure at the berths for the coming week which can guide the port operator to select the most suitable time for arrival and berthing and selecting the optimal berth for the planned loading/unloading operation
Effect of organic loading on nitrification and denitrification in a marine sediment microcosm
No full textThe effects of organic additions on nitrification and denitrification were examined in sediment microcosms. The organic material, heat killed yeast ,had a C/N ratio of 7.5 and was added to sieved, homogenized sediments. Four treatments were compared: no addition (control), 30 g dry weight (dw) m⁻² mixed throughout the 10 cm sediment column (30M), 100 g dw m⁻² mixed throughout sediments (100M), and 100 g dw m⁻² mixed into top 1 crn (100S). After the microcosms had been established for 7-11 days, depth of O2 penetration, sediment-water fluxes and nitrification rates were measured. Nitrification rates were measured using three different techniques: N-serve and acetylene inhibition in intact cores , and nitrification potentials in slurries. Increased organic additions decreased O₂ penetration from 2.7 to 0.2 mm while increasing both O₂ consumption, from 30 to 70 mmol O₂ m⁻² d⁻¹ , and NO₃⁻ flux into sediments. Nitrification rates in intact cores were similar for the two methods. Highest rates occurred in the 30M treatment, while the lowest rate was measured in the 100S treatment. Total denitrification rates (estimated from nitrification and nitrate fluxes) increased with increased organic addition, because of the high concentrations of NO₃⁻ (40 µM) in the overlying water. The ratio of nitrification: denitrification was used as an indication of the importance of nitrification as the NO₃⁻ supply for denitrification. This ratio decreased from 1.55 to 0.05 with increased organic addition.Journal ArticleFinal article publishe
Berm breakwater structures: Roundhead stability of berm breakwaters
No full textFor berm breakwaters as compared with traditional rubble mound breakwaters, special measures have to be taken for the breakwater roundhead. If stone displacements occur on a roundhead, the stones will be moved in the wave direction and will loose most of their stabilising effect. The major part of the research on berm breakwaters has concentrated on the reshaping of the seaward side of the trunk under perpendicular wave attack. Only a little research has been made to study the stability of berm breakwater roundheads (eg Burcharth and Frigaard, Jensen and Sorensen, and Van der Meer and Veldman). Comprehensive three-dimensional (3D) model tests were carried out to study the reshaping of the roundhead as function of the wave conditions (wave height and wave period) and the angle of wave incidence. The reshaping process and the movements of stones on the berm were analysed based on both profile measurements and observations.Berm Breakwater
Berm breakwater structures: Roundhead stability of berm breakwaters / Reshaping breakwater - Longshore transport and recession of the berm
No full textFor berm breakwaters as compared with traditional rubble mound breakwaters, special measures have to be taken for the breakwater roundhead. If stone displacements occur on a roundhead, the stones will be moved in the wave direction and will loose most of their stabilising effect. A point of special concern is whether, and under which conditions, a berm breakwater roundhead will develop in a way that in the long-term will lead to structural failure. The major part of the research on berm breakwaters has concentrated on the reshaping of the seaward side cif the trunk under perpendicular wave attack. Only a little research has been made to study the stability of berm breakwater roundheads (eg Burcharth and Frigaard, Jensen and Serensen, and Van der Meer and Veldman). Comprehensive three-dimensional model tests have been carried out to study the reshaping of the roundhead as function of the wave conditions (wave height and wave period) and the angle of wave incidence. The reshaping process and the movements of stones on the berm have been analysed based on both profile measurements and observations.Berm Breakwater
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