512 research outputs found
Hoogwater 2021: Feiten en Duiding
No full textIn juli 2021 zijn grote delen van Limburg getroffen door hevige regenval en overstromingen. Ook delen van België en Duitsland overstroomden met zeer veel schade en verlies aan mensenlevens tot gevolg. Dit betrof een extreme en ongeëvenaarde gebeurtenis met enorme impact. Daarom is naar aanleiding van de overstromingen deze verkenning uitgevoerd om een eerste stap te maken om beschikbare informatie over deze gebeurtenis te verzamelen en analyseren. Het onderzoek is uitgevoerd door een breed consortium (TU Delft, Deltares, HKV Lijn in Water, VU Amsterdam, Universiteit Utrecht, KNMI, WUR, Erasmus MC en Universiteit Twente) in opdracht van het Expertise Netwerk Waterveiligheid (ENW). Een overstroming heeft effect op de hele maatschappij. Daarom zijn niet alleen hydrologische en civieltechnische onderwerpen beschouwd, maar ook de maatschappelijke gevolgen van overstromingen, de crisisrespons en de gezondheidseffecten.Contributors (in alphabetical order): Nathalie Asselman (Deltares), Hermjan Barneveld (HKV / Wageningen UR), Jules Beersma (KNMI), Eline Boelee (Deltares), Wouter Botzen (VU Amsterdam), Eefke Copper (TU Delft), Dim Coumou (KNMI), Karin de Bruijn (Deltares), Anniek de Jong (Deltares), Jurjen de Jong (Deltares), Hans de Moel (VU Amsterdam), Ferdinand Diermanse (Deltares), Astrid Fischer (Evides) , Gert-Jan Geerling (Deltares), Marie-Louise Geurts (WML), Rob Groenland (KNMI), Mark Hegnauer (Deltares), Bas Jonkman (TU Delft), Nicole Jungermann (KNMI), Frans Klijn (Deltares), Andre Koelewijn (Deltares), Matthijs Kok (HKV / TU Delft), Elco Koks (VU Amsterdam), Bas Kolen (HKV / TU Delft), Marion Koopmans (Erasmus MC), Laurens Leunge (Deltares), Hans Middelkoop (Utrecht University), Roelof Moll (TU Delft), Jaap Mos (Dunea), Sjoukje Philip (KNMI), Gerbert Pleijter (HKV), Joost Pol (HKV / TU Delft), Stephan Rikkert (TU Delft), Guus Rongen (TU Delft), Rinus Scheele (KNMI), Julius Schlumberger (TU Delft), Peter Siegmund (KNMI), Kymo Slager (Deltares), Frederiek Sperna Weiland (Deltares), Bart Strijker (HKV / TU Delft), Henk v.d. Brink (KNMI), Janko van Beek (Erasmus MC), Marion van den Bulk (TU Delft), Bart van den Hurk (Deltares), Tim van Emmerik (Wageningen UR), Kees van Ginkel (VU Amsterdam / Deltares), Mick van Haren (TU Delft), Margreet van Marle (Deltares), Malou van Schaijk (TU Delft), Dennis Wagenaar (Nanyang TU), Davide Wüthrich (TU Delft)Hydraulic Structures and Flood RiskSafety and Security ScienceCoastal Engineerin
Medical history and lifestyle factors have limited impact on time-to-first-treatment in patients with chronic lymphocytic leukemia
No full textBackground Chronic lymphocytic leukemia (CLL) is a heterogeneous disease. Whereas some patients have an indolent disease, others experience an aggressive course and early death. Our aim was to investigate if modifiable and non-modifiable medical history and lifestyle factors prior to diagnosis had an impact on the natural course of the disease. Method In 1154 CLL patients, we assessed if the weight, physical activity, smoking, and alcohol consumption or non-modifiable characteristics including family history of lymphoid malignancy and medical history were associated with time-to-first-treatment (TTFT) and adjusted all results for the CLL-International Prognostic Index (CLL-IPI). Results TTFT was shorter for patients with high/very high-risk CLL-IPI than those with low/intermediate risk CLL-IPI. In the adjusted analysis we did not find additional impact on TTFT besides CLL-IPI from any environmental characteristics assessed. Conclusions We found limited impact of environmental factors on the natural course of CLL (measured as the TTFT in treatment na & iuml;ve patients) providing valuable knowledge, and potential relief, to share with patients at the time of diagnosis. How patients have lived their life (i.e. degree of physical activity, smoking and alcohol consumption) has no impact on the natural course of chronic lymphocytic leukemia (CLL), measured as time to first treatment, while CLL-international prognostic index (IPI) and its components strongly predicts prognosis. imageIngrid Glimelius and Geffen Kleinstern contributed equally to the first authorship and Susan L. Slager and Karin E. Smedby contributed equally to the last authorship.</p
Bereiding van acrylzuur
No full textDocument(en) uit de collectie Chemische Procestechnologie.DelftChemTechApplied Science
Santos, Rotterdam: From vacant to active monument, a creative office for Katendrecht
No full textSantos is a warehouse from the beginning of the 20th century, that has been vacant for most of its existence. Located on Katendrecht, it is placed right in the middle of a future high-density plan for 'de Pols', which focuses on attracting urban creators. By turning Santos into a creative office, the thesis builds upon these plans from the municipality, and attempts to once again turn Santos into a building that houses activity, instead of vacancy. The main design challenge concerns maintaining the industrial spirit of place, and the important clue that Santos provides towards Katendrecht's harbour history, all while creating the pleasant working conditions that an office requires (daylight being the most prominent one)
Security Evaluation of GoQuorum-based Smart Contracts: A Case Study of Malfunctioning Access Control and Double-Spending
No full textGoQuorum is an enterprise blockchain platform that supports smart contracts and allows for private transactions. Smart contracts enable automated payment while eliminating the need for third-party involvement. Previous attacks on smart contracts have already shown that existing vulnerabilities can lead to great financial losses. Yet, a study focusing specifically and exclusively on the security of GoQuorum-based smart contracts does not yet exist. This work evaluates two vulnerabilities: faulty use of tx.origin in authentication and private state divergence. Three attacks are demonstrated, leading to draining a contract's ether balance and double-spending. MythX is recommended to detect vulnerable code, while replacing tx.origin with msg.sender eliminates the vulnerability. It is concluded that Zero-Knowledge Proofs are a promising solution to validate transactions while maintaining privacy, although applying them to GoQuorum requires more research and development.CSE3000 Research ProjectComputer Science and Engineerin
Process Status Evaluating Tool: How can the pump process be evaluated pumping water?
No full textDamen Dredging Equipment (DDE) has a quest to make their cutter suction dredger (CSD) and their DOP pump operable by everyone for every slurry type at the correct working point every time. To complete this quest, first a process status evaluating tool has to be developed which replaces the visual wear inspection. This thesis is the first step in developing this tool, its research question hence is "How can the pump process status be evaluated pumping water?" To answer this question, first a literature study about a centrifugal pumpis done (chapter 1) to understand the working principle of a centrifugal dredge pump. Next, the wear locations in a centrifugal dredge pump are going to be examined (chapter 3) after a small wear definition introduction (chapter 2). From the wear locations found, the ones that are expected to have the most influence on the pump performance (head H and efficiency ´) are further researched in this thesis. These locations are: the axial gap and the inner impeller diameter. For the axial gap, data was already available due to previous research at DDE [1]. The data for the influence of the inner impeller diameter change is created by own experiments on the sediment transport circuit at DDE, these experiments are explained in chapter 5. Also another conditionmonitoring option (not only the influence of the pump parameters) is researched after different possibilities were investigated (chapter 4). This method is the vibration analysis of the pump and is used to see whether or not the influence of wear on the pump can bemonitored. This wear is created by pumping a slurry (sand-water) mixture through the sediment transport circuit while using casted steel for the impeller and wear plate (it would take a lot of time to create wear on the original nihard impeller and wear plate). The data for the axial gap, inner impeller diameter and vibrational analysis is explained in chapter 6. The research question can be answered in two parts: the influence on the pump parameters and the vibration analysis of the pump. The data analysis of the influence of the axial gap on the pump parameters (section 6.1) shows that it is possible to indicate whether the axial gap is small or large (2mm vs 11mm) by using a trialand- error method proposed in this study. The data analysis of the inner impeller diameter (section 6.2) shows two methods to calculate the inner diameter increase from the data obtained during the own experiments. Both methods are based on the change of the velocity triangles resulting in an extended version of the pump affinity law for head. The NPSH could not be measured decent, so no model is obtained for this. The last part to answer the research question is the vibrational analysis (in radial, axial and tangential direction). The BEP point can be found using the vibrational analysis (lower vibration level). Also cavitation in the pump is detected by the vibrational analysis (high scattering of vibrational data points). A last thing that can be seen is when the pump operates left from the BEP, the axial vibration level increases a lot. All the findings in chapter 6 should be tested for not only the DOP250, but for a various range of pumps and settings. This to conclude if the findings are applicable for every pump, or only for the DOP250 in setting used in the sediment transport circuit.Mechanical, Maritime and Materials EngineeringOffshore & dredging engineerin
Relatie korreldiameter en K-waarde voor sterk gegradeerde mengsels
No full textDe doorlatendheid van zand kunnen bepalen met één gegeven, de bepalende korreldiameter, is wegens het gemak in gebruik lange tijd een streven geweest, en is het nog steeds. De relatie tussen korreldiameter (d) en doorlatendheid (K-waarde) is door velen aangetoond, maar twijfel is er of deze relatie ook aanwezig is voor sterk gegradeerde zandmengsels. Uit een literatuurstudie volgt de kwadratische invloed van de korreldiameter op de K-waarde. Ook valt de dominantie van de formule van Kozeny-Carman over andere, vooral empirisch vastgestelde formules, op. De formule van Kozeny-Carman bevat een parameter S, het specifiek oppervlak. Deze parameter is gedefinieerd als de verhouding tussen het oppervlak en het volume van het zandmonster, gelijk aan 1/d. Volgens Kozeny-Carman is de invloed van deze parameter S op de K-waarde omgekeerd kwadratisch, wat neerkomt op een kwadratisch invloed van de korreldiameter. Door het specifiek oppervlak van het gehele monster te bepalen, wordt de invloed van elke korrel in het monster in rekening gebracht. Verschillende doorlatendheidsproeven zijn uitgevoerd met sterk gegradeerde mengsels, en de resultaten vergeleken met de voorspelling van Kozeny-Carman. Er kan geconcludeerd worden dat voor sterk gegradeerde mengsels de relatie tussen korreldiameter en K-waarde aanwezig is, en kwadratisch van aard. De beste manier om de invloed van verschillende korreldiameters in een monster weer te geven is door gebruik te maken van fracties met ieder een eigen gewichtspercentage en korreldiameter (zie rapport voor exacte formule).Hydraulic EngineeringHydraulic EngineeringCivil Engineering and Geoscience
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