190 research outputs found
Development of the hub port of Colombo, Sri Lanka
No full textThe Port of Colombo, Sri Lanka, is an important hub port in the Indian Ocean. A hub port is a port with mainly transhipment (and in this case container) throughput, which means that most of the cargo is not for the country itself, but for countries in the region. The yearly container throughput at the Port of Colombo reached its full capacity of 1.7 million TEU per year in 1997. Increasing waiting times for ships calling at the port are a result of this. Because of the costs of a waiting ship, shipping lines will choose other ports in the region such as Singapore, Salalah (Oman) or Dubai (United Arab Emirates) for their ships to go to. The aim of this study is to develop a plan for a New Container Terminal, which will give the Port of Colombo enough container throughput capacity for the next 25 years: till the year 2025.Hydraulic EngineeringCivil Engineering and Geoscience
Identification and regionalization of dominant runoff processes – a GIS-based and a statistical approach
No full textIn this study two approaches are presented to identify Dominant Runoff Processes (DRP) with respect to regionalization. The approaches are a simplification of an existing method to determine DRP by means of an extensive field campaign. The first approach combines the permeability of the substratum, land-use and slope of the basin in a GIS-based analysis. The second approach makes use of discriminant analysis of the physiographic characteristics of the basin and links it to the GIS analysis. The results of the developed approaches are maps, which identify dominant runoff processes and represent a spatial distribution of the hydrological behaviour of the soil during prolonged rainfall events. The approaches have been developed in a micro-scale basin (Germany). An additional meso-scale basin was introduced in which the two approaches were applied for quality control. The thus generated maps for the micro-scale basin were compared with an existing DRP map, which was derived with the existing method. The first approach showed a resemblance of 79% when compared to this map, whereas the second approach showed only a resemblance of 51%. The generated maps for the meso-scale basin were compared to DRP that were determined point wise according to the existing method. The first approach showed in this case a resemblance of 81%, whereas the second approach showed a resemblance of 68%. Therefore, the first approach is preferred to the second approach when accuracy, data input and calculation time are concerned.WatermanagementCivil Engineering and Geoscience
Binnenvaart Service Centrum op Maasvlakte 2: Een haalbaarheidsstudie
No full textOp moment van schrijven is de aanleg van Maasvlakte 2 in volle gang. Het masterplan is echter nog in ontwikkeling, maar steeds meer keuzes worden vastgelegd. Daarom moet onderzocht worden of er op Maasvlakte 2 een ruimteclaim voor een Binnenvaart Service Centrum (BSC) moet blijven staan. Een BSC is een neutrale binnenvaartterminal waar een deel van de binnenvaartcontainers van de verschillende zeeterminals worden afgehandeld. Het BSC heeft een aantal functies. Het BSC vangt de kleine call sizes af voor de terminals. Het BSC vermindert het hoppen voor de binnenvaart. Het BSC biedt een uitwijkmogelijkheid wanneer er calamiteiten op de terminal optreden. En daarnaast kan een BSC een deel van de empty’s (lege containers) afhandelen. Als eerste zijn een aantal varianten van binnenvaartafhandeling vergeleken. Uit deze analyse volgt dat het opdelen van de kadelengte in diepe zeekade en een deel “dedicated” binnenvaart/feederkade een positieve invloed heeft op de wachttijden en de investeringskosten. Daarnaast volgt uit deze analyse dat bij de ontwerpoverslag op Maasvlakte 2 geen lange wachttijden ontstaan. Een BSC heeft hierdoor weinig invloed op de wachttijden. Ook volgde uit de analyse dat een BSC een positieve invloed heeft op de wachttijden voor zeeschepen en feeders. De terminaloperators hebben hierdoor belang bij een BSC. Naar aanleiding van deze conclusies is het BSC benaderd vanuit de optiek van de terminaloperators. Hierbij is de situatie bekeken waarbij de terminals de maximale overslagcapaciteit bereiken. Vervolgens is gesimuleerd hoe groot de extra overslagcapaciteit is wanneer kleine call sizes naar een BSC worden gestuurd. Hieruit volgt dat wanneer alle calls kleiner dan 25 TEU naar een BSC worden gestuurd, er 5% meer volume overgeslagen kan worden. Voor elke TEU die via het BSC overgeslagen wordt kan 5 TEU extra zeevolume aan de terminal worden overgeslagen. Wanneer alle calls kleiner dan 50 TEU naar het BSC worden gestuurd is deze verhouding lager. Hierbij kan voor elke TEU over het BSC 1,65 TUE extra zeevolume worden overgeslagen. Vervolgens is het BSC voor een stuurcriterium van 25 TEU verder uitgewerkt. Dit BSC moet een capaciteit hebben van 430.000 TEU. Hieruit volgt dat er 6 ligplaatsen nodig zijn, dit is een kadelengte van 554m. 554m is 3% extra ondiepe kadelengte waardoor 5% extra overgeslagen kan worden aan de diepe zeekade. Voor dit BSC zijn een aantal mogelijke locaties bekeken. Uit de MCA volgt dat de Hartelhaven de meest geschikte locatie is voor het BSC. Voor deze locatie is een ontwerp gemaakt met Wide Span Gantry kranen, en transport per MTS. Daarnaast is een ontwerp gemaakt voor een willekeurige locatie op Maasvlakte 2. Hierbij is geprobeerd het ontwerp zo compact mogelijk te houden, zodat het op verschillende plaatsen ingepast zou kunnen worden. Dit ontwerp is uitgevoerd met insteekhavens en het transport vind plaats per AGV. Voor beide ontwerpen zijn de kosten bepaald. De kosten voor het overslaan van 1 TEU op het conventionele BSC zijn \u8047,04. Voor het moderne ontwerp liggen de kosten hoger namelijk \u8047,38 per TEU. De conventionele variant is goedkoper omdat op de locatie in de Hartelhaven al voorzieningen aanwezig zijn. Voor de exploitatie gaat de voorkeur uit naar een coöperatie van de stuwadoors, want wanneer zij meedragen in de investeringskosten zullen zij ook gebruik gaan maken van het BSC.Hydraulic engineeringCivil Engineering and Geoscience
Theories, Experiments, Tools: An applied hydrological spatio-temporal assessment of meso-scale basins with a view to regionalization
No full textThe thesis treats a selection of hydrological studies, which make use of a variety of models and approaches that have a common character: simplicity. Simplicity implies parsimonious use of parameters. These studies offer opportunities for hydrological research that are not, or hardly achievable with more complex models and approaches. In the thesis, these models and approaches are equated with simple and versatile hydrological tools. It is demonstrated that these hydrological tools have a mature and specific function in science as well as in practice and that such types of tools are indispensable to assess the hydrological behaviour of ungauged river systems, for hydrological research in general and for water management purposes. Furthermore, these hydrological tools can be seen as powerful instruments for the necessary communication between modellers and field experimentalists. Three criteria are introduced that hydrological tools fulfill to be suited for predictions in ungauged basins. These criteria are: representing climate fluctuations and its impact on the hydrological regime; possessing a potential for the transfer of information from gauged basins to ungauged basins; predicting and analysing hydrological behaviour. A number of hydrological toolsare presented, which are specified for a certain topic and subsequently the application of one or several of the tools should increase the knowledge of the hydrological functioning of a study area. Moreover, it is proposed that the tools themselves are fit for improvement when flaws have been identified during and after their application.WatermanagementCivil Engineering and Geoscience
On applying the set covering model to reseeding
No full textThe Functional BIST approach is a rather new BIST technique based on exploiting embedded system functionality to generate deterministic test patterns during BIST. The approach takes advantages of two well-known testing techniques, the arithmetic BIST approach and the reseeding method. The main contribution of the present paper consists in formulating the problem of an optimal reseeding computation as an instance of the set covering problem. The proposed approach guarantees high flexibility, is applicable to different functional modules, and, in general, provides a more efficient test set encoding then previous techniques. In addition, the approach shorts the computation time and allows to better exploiting the tradeoff between area overhead and global test length as well as to deal with larger circuits
Geochemistry of a long in-situ section of intrusive slow-spread crust: Results from IODP Site U1309 (Atlantis Massif, 30°N Mid-Atlantic-Ridge)
No full textIODP Site U1309 was drilled at Atlantis Massif (western rift flank of Mid-Atlantic Ridge (MAR) 30°N; Expeditions 304 and 305), a 1.5-2 Myr old oceanic core complex. The main hole, Hole U1309D, is the second deepest hole drilled into an intrusive slow-spread oceanic lithosphere: it penetrated 1415.5 mbsf (75% recovery). We present here the results of a bulk rock geochemical study (major and trace elements – ICPMS -) carried out on 234 samples representative of the different lithologies sampled at Site U1309. Over 96% of Hole U1309D is made up of gabbroic rocks, cross-cut by late diabases and basaltic dykes in the upper part of the section. Diabases and basalts have depleted MORB compositions (La/Yb ~0.8 and Yb ~ 3.5 ppm) similar to basalts sampled at MAR 30°N. Relics of mantle were recovered at shallow depth. Mantle peridotites show petrographic evidence of melt impregnation. They have relatively fertile compositions, similar to MARK peridotites, with Mg# (100xMg/(Mg+Fe)) of 89-90, Ni>2400ppm and Yb 0.03-0.11 ppm. Gabbroic rocks span a wide range of lithologies and geochemical compositions. They comprise olivine-rich troctolites (>70% modal olivine), troctolites, olivine and troctolitic gabbros (5 to 50% modal olivine), gabbros (including gabbronorites) and oxide gabbros (>2% modal Fe-Ti oxides), which represent respectively 5.4 %, 2.7%, 25.5%, 55.7% and 7% of the core recovered at Hole U1309D. Minor felsic ("leucocratic") dikes cross- cutting gabbros were also sampled. Troctolites and olivine-rich troctolites have high Mg# (82-89), high Ni (up to 2300 ppm) and low trace element contents (Yb 0.06-0.8 ppm). They overlap in composition with peridotites sampled at Atlantis Massif and with impregnated peridotites drilled along the MAR (e.g., ODP Site 1271 (MAR 15°20'N)). Gabbros and olivine gabbros have high Mg# (60-86) and low trace element contents (Yb 0.125-2.5 ppm – (La/Yb)CN ~ 0.4-0.7); these gabbros are among the most primitive and depleted yet sampled along slow spreading ridges (e.g., MAR 23°N and 15°20'N and ODP Hole 735B on the Southwest Indian Ridge). Oxide gabbros and leucocratic dykes represent the most evolved end-members of the gabbroic suite with low Mg# (<50), low Ni (~65 ppm) and high trace element contents (Yb up to 26 ppm). Troctolites and gabbros have Eu positive anomalies (Eu/Eu* ~1.4) whereas oxide gabbros and leucocratic dykes have Eu negative anomalies (Eu/Eu* ~0.75). The former are interpreted as cumulates of a common parental magma, while the later precipitated after the differentiated melts. We note that gabbros and gabbronorites overlap in composition, thus precluding precipitation after a significantly more evolved melt for orthopyroxene crystallization. The bulk composition of gabbroic rocks from Hole 1309D shows no Sr or Eu anomalies; although there may have been local separation of melt and solids, there was no large scale removal of melts from this gabbro section. It is somewhat depleted in the most incompatible elements compared to parental MORB with Ba (40%), Nb (40%) and Rare Earth Elements (REE: Ce 70%, Yb 95%), but enriched in compatible and refractory elements such as Mg (120%) or Ni (200%) and Cr (200%). This may indicate strong chemical interaction between the parental melt and the intruded (assimilated?) shallow depleted mantle, probably during the earliest stages of the formation of Site U1309 gabbroic body. Olivine-rich troctolites may represent the ultimate residue of this reaction- accumulation process
*Corresponding author
No full textAn efficient fault tolerant mechanism to deal with permanent and transient failures in a network on chi
A gene (RPGR) with homology to the RCC1 guanine nucleotide exchange factor is mutated in X-linked retinitis pigmentosa (RP3)
No full textX-linked retinitis pigmentosa (xIRP) is a severe progressive retinal degeneration which affects about 1 in 25,000 of the population. The most common form of xIRP, RP3, has been localised to the interval between CYBB and OTC in Xp21.1 by linkage analysis and deletion mapping. Identification of microdeletions within this region has now led to the positional cloning of a gene, RPGR, that spans 60 kb of genomic DNA and is ubiquitously expressed. The predicted 90 kD protein contains in its N-terminal half a tandem repeat structure highly similar to RCC1 (regulator of chromosome condensation), suggesting an interaction with a small GTPase. The C-terminal half contains a domain, rich in acidic residues, and ends in a potential isoprenylation anchorage site. The two intragenic deletions, two nonsense and three missense mutations within conserved domains provide evidence that RPGR (retinitis pigmentosa GTPase regulator) is the RP3 gene
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