2,957 research outputs found
Interaction Between Alternative Income Measures: Effects on the Significance of Market Association Tests
No full textDevelopment of an Atomic Force Microscope
No full textThis abstract presents the development of an Atomic Force Microscope (AFM) vertical scanner for surface topography measurements, which is composed of a single axis positioning stage with an integrated metrology system and AFM probe. The scanner is meant to track and measure a maximum topography step of 10 ?m with a measurement resolution of less then 0.1 nm and an uncertainty of less than 10 nm (1←) at a controllable bandwidth of at least 2 kHz.Precision and Microsystems EngineeringMechanical, Maritime and Materials Engineerin
Concrete Flow in Diaphragm Wall Panels: A Full-Scale In-Situ Test
No full textFlow processes, taking place during the concreting of diaphragm wall panels (D-wall panels), are of great importance for the quality of the wall. During this phase, the bentonite, present in the excavated trench, should be completely replaced by concrete in a controlled way. In literature several cases are described in which this process resulted in bentonite inclusions in the panel. These inclusions often lead to severe problems, like leakages, for the building pit to be excavated within the diaphragm wall panels. Beside the risks for the building pit, leakages caused by bentonite inclusions can also have large consequences for nearby constructions. In this article, set up and results of a full-scale diaphragm wall test are described. Conclusions are drawn with regard to the influence of several parameters on the flow process and subsequently on the quality of the wall and the risk on bentonite inclusions
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/5e17b7c9-4bca-4fcf-8784-0915783532dd/thumb/128.jpgIt is possible that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/c9f13811-9c93-449b-8b79-31dd26e7a981/thumb/128.jpgIt is probable that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/413865c0-390a-449d-9d4e-f69f66754b8e/thumb/128.jpgIt is possible that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Verification of BREAKWAT for berm breakwaters and low-crested structures
No full textThis report describes the verification of the model on dynamic stability for berm breakwaters. The model runs on a pc and is called BREAKWAT. The data received from various people allover the world contained not only berm breakwaters, but also dynamically stable low-crested structures. The title of the report was therefore changed to "Verification of BREAKWAT for berm breakwaters and low-crested structures". The calculations were performed and the report was written by Dr. J.W. van der Meer of Delft Hydraulics
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/48a1abe6-3896-473b-bc17-0796ead5e587/thumb/128.jpgIt is probable that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
J.W. Waterhouse 1849-1917: The Modern Pre-Raphaelite
No full textThis is the catalogue for the exhibition J.W. Waterhouse: The Modern Pre-Raphaelite, held at the Groninger Museum, Groningen, the Netherlands (14 December 2008 - 3 May 2009), Royal Academy of Arts, London (27 June - 13 September 2009), and Montreal Museum of Fine Arts (1 October 2009 - 7 February 2010). The catalogue is co-authored and co-edited by the curators of the exhibition: Elizabeth Prettejohn (author of pp. 23-35 and 48 of the 100 catalogue entries), Peter Trippi, Robert Upstone, and Patty Wageman. The book won the Historians of British Art Prize for best multi-authored book 2010 (affiliated society to the College Art Association, USA).This is the catalogue for the exhibition J.W. Waterhouse: The Modern Pre-Raphaelite, held at the Groninger Museum, Groningen, the Netherlands (14 December 2008 - 3 May 2009), Royal Academy of Arts, London (27 June - 13 September 2009), and Montreal Museum of Fine Arts (1 October 2009 - 7 February 2010). The catalogue is co-authored and co-edited by the curators of the exhibition: Elizabeth Prettejohn (author of pp. 23-35 and 48 of the 100 catalogue entries), Peter Trippi, Robert Upstone, and Patty Wageman. The book won the Historians of British Art Prize for best multi-authored book 2010 (affiliated society to the College Art Association, USA)
Wave forces on vertical breakwaters: Reliability of design formula
No full textThrough the increasing draught of large vessels the need for breakwaters at greater depths becomes more and more important. In this respect vertical breakwaters may be the best alternative because of the considerable savings in construction time as well as the lower construction and maintenance costs. Therefore a lot of research is performed nowadays in order to obtain better understanding of the dynamic processes involved. Until then the design of vertical breakwaters is based on the quasi-static approach. The formula of Goda is one of the latest design methods based on the quasi-static approach. Goda's formula is used world-wide, it is however not known in what way it describes reality. Therefore the empirical character of Goda's formula is investigated. From the comparison of measured values and values calculated with Goda's formula it is clear that Goda overestimates the wave forces and overturning moments. Especially for inclined superstructures Goda overestimates the uplift and horizontal force. It is tried to find an explanation for the overestimation but conclusions could not be drawn, partly caused by the scatter in the measurements. It is however clear that the height and the shape of the superstructure, the wave period, breaking (or non-breaking) of the waves on the foreshore and the presence of a rubble-mound foundation have large influence on the measured wave forces. For the horizontal forces Van der Meer et al., (1993) proposed a modification of Goda's formula. This modification implies that the crest height is determined at the transition from vertical to inclined, and not at the top of the structure. Good results are also obtained when this modification is used for the calculation of the overturning moments, caused by the horizontal force. As far as the uplift force and the moment caused by this force is concerned it can be said that Goda is only valid for breakwaters with a vertical superstructure. In order to determine the reliability of Goda's formula the bias and the scatter in the measurements are described. Therefore the exceedance curves of the forces and moments were investigated. A two parameter Weibull distribution was fitted through the 5%..0.1% exceedance probabilities. The shape parameter was found to be close to 2, implying the Rayleigh distribution. This Rayleigh distribution is rewritten into an expression for the exceedance probability of all forces and moments depending only on the modified Goda formula. With this expression probabilistic calculations have been performed. It is found that the horizontal and uplift force, calculated with the modified Goda formula, are inside the 90% confidence bound obtained from the easurements. The same thing holds for the overturning moments caused by these forces. Due to the high scatter in the measurements it is advised to rely on physical model tests rather than on the formula of Goda. (This report is also published as Delft Hydraulics report H1903).Hydraulic EngineeringCivil Engineering and Geoscience
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