142 research outputs found
Final Report Levee Challenge: Team Hans Brinker
No full textIn this assignment we simulate a two meters wide dike stretch which is subjected to overflow. Three failure mechanisms could occur due to overflow: full erosion of the soil of the dike, macro instability of the levee if too much soil is eroded away, leading to insufficient counterweight on the inside of the levee, and surface slip failure due to reduction of strength of the dike by flow of water in the dike core. Prevention of failure can be achieved by either keeping the water away from the berm surface or holding the soil particles in place while the water flows alongside it. The desired repair is an emergency repair that can placed quickly during a storm, or between two storms to prevent a damaged levee from failing. This is a temporary repair that will later be removed for full reconstruction of the levee. This provides constraints to the installation and repair procedure.To decide which solution is best, 10 concept solutions are compared based on their score in the Multi Criteria Analysis with 8 weighted criteria. The solution with the highest score is the best solution according to the Multi Criteria Analysis. The selected repair option is to locally cover the damaged area with flexible overlapping sheets of Tyvek®. This is a light and thin material that can easily be transported and cut to size at the location of the repair. These sheets can be easily secured against flow loads using Gripple anchors, while pins are used to keep the Tyvek® in place during windy conditions. An installation plan and cost breakdown was made. Using 3 m wide Tyvek® rolls, the costs would be around 19.19 euros per meter height.The damaged areas of the levee are covered with Tyvek® which is a waterproof, damp open material. This prevents the penetration of water into the core through the damaged areas. The Tyvek® also prevents the exposed soil from being eroded. Moreover, Tyvek® is a very strong material that won’t be torn off. As there is no strength reduction due to water penetration or further loss of surface material the chance for macro instability is minimized.First, a design was created, with components dimensioned for a dike stretch in the Hedwigepolder. Subsequently, the design was validated with tests. Including two types of damage. The first was removal of a 2 by 2 m grass layer (0.1 m thick) at the top of the dike and the second was a dug-out step-section across the entire width of the dike with a height difference of 0.5 meters at the toe of the dike. Only the second damage went through the clay layer and into the sand core of dike.During and after the tests some important observations were made. During all test volumes the plastic sheets were kept in place due to the anchors and pins. Some pins however, came loose due to vibration of the sheets (we presumed the cause of vibration is flow of water between two sheets or turbulence of water). The trench of the lower damage was partly washed away by the water. The erosion of soil in the trench did not result in changing the stability of the top sheet. At the lower damage the plastic sheet was torn off after a tear of 1 m was made with a knife.Our solution is designed to protect any dike from macro-instability by keeping the water flow away from the berm. This is done by layering multiple sheets of plastic foil over the inner berm, fastened with ground anchors and pins. The solution is a durable and reliable design due to proven waterproof, damp open and UV resistant properties, together with Gripple's demonstrated anchoring capabilities. Another major advantage of our solution is that the repair of the damage is selective, i.e. the solution is applied only to the parts of the levee where damage has occurred. In case of only localized and small damage to the levee, the costs and workload are very minimal compared to other solutions that are applied to the entire surface area of the levee.Polder2CCivil Engineerin
Finerenone and left ventricular hypertrophy in chronic kidney disease and type 2 diabetes
No full textAbstract Aims Left ventricular hypertrophy (LVH) has been associated with an increased risk of cardiovascular (CV) disease and linked to increased morbidity and mortality. In patients with chronic kidney disease (CKD) and type 2 diabetes (T2D), hypertension is common, and patients with these co‐morbidities additionally have a high prevalence of LVH. This analysis of the prespecified pooled FIDELITY analysis comprising the randomized, double‐blind, placebo‐controlled, multicentre FIDELIO‐DKD and FIGARO‐DKD phase III studies aimed to explore the CV and kidney effects of finerenone, a nonsteroidal mineralocorticoid receptor antagonist, in patients with CKD and T2D stratified by a diagnosis of LVH at baseline. Methods and results A diagnosis of LVH in the FIDELITY patient population was determined at baseline using investigator‐reported electrocardiogram (ECG) findings. The two efficacy outcomes, assessed by baseline LVH, were the composite CV outcome of time to CV death, non‐fatal myocardial infarction, non‐fatal stroke, or hospitalization for heart failure (HHF), and a composite kidney outcome of time to onset of kidney failure, a sustained decrease in estimated glomerular filtration rate (eGFR) ≥57% from baseline over ≥4 weeks, or kidney‐related death. Safety outcomes by baseline LVH were reported as treatment‐emergent adverse events. At baseline out of 13 026 patients in FIDELITY, 96.5% had hypertension and 9.6% had investigator‐reported LVH. The relative risk reduction for the composite CV and kidney outcomes with finerenone versus placebo was lower in the LVH subgroup; however, the treatment effect of finerenone was not modified by baseline LVH for either outcome ( P interaction = 0.1075 for composite CV outcome and P interaction = 0.1782 for composite kidney outcome). Analysis of the composite CV outcome components showed a greater reduction in the risk of HHF versus placebo for patients with baseline LVH compared with those without ( P interaction = 0.0024). Overall safety events were comparable between the LVH subgroups and treatment arms. Treatment‐emergent hyperkalaemia was observed more frequently with finerenone versus placebo, but discontinuation rates were low in both treatment arms and between LVH subgroups. Conclusions In conclusion, the overall CV and kidney benefits of finerenone versus placebo were not modified by the presence of LVH at baseline, with overall safety findings being similar between LVH subgroups. A greater benefit was observed for HHF in patients with versus without LVH, suggesting that LVH may be a predictor of the treatment effect of finerenone on HHF.Bayer https://doi.org/10.13039/10000432
A nonspectroscopic method to determine the photolytic decomposition pathways of 3-chloro-3-alkyldiazirine: Carbene, diazo and rearrangement in excited state
No full textC-60 acts as a mechanistic probe for the formation of carbene, diazo compound, and for the rearranged product via the excited state in the photolysis of 3-chloro-3-isopropyldiazirine and 3-chloro-3-chloromethyldiazirine. The carbene adds to C-60 to form methanofullerene, whereas the diazo compound adds to C-60 to form fulleroid. The olefin product arises as a result of the rearrangement in the excited state.PT: J; CR: AKASAKA T, 1999, J ORG CHEM, V64, P566 AKASAKA T, 1999, ORG LETT, V1, P1509 AKASAKA T, 2000, J AM CHEM SOC, V122, P7134 ARENAS JF, 2002, J AM CHEM SOC, V124, P1728 BECKE AD, 1988, PHYS REV A, V38, P3098 BECKE AD, 1993, J CHEM PHYS, V98, P5648 BONNEAU R, 1996, J AM CHEM SOC, V118, P3829 BONNEAU R, 1996, J AM CHEM SOC, V118, P7229 BRINKER U, 1994, ADV CARBENE CHEM, V1 BRINKER U, 1998, ADV CARBENE CHEM, V2 FRISCH MJ, 1998, GAUSSIAN 98 GRAHAM WH, 1965, J AM CHEM SOC, V87, P4396 HIRSCH A, 1993, CHEM BER, V126, P1061 JACKSON JE, 1988, J AM CHEM SOC, V110, P595 LAVILLA JA, 1989, J AM CHEM SOC, V111, P6877 LAVILLA JA, 1989, J AM CHEM SOC, V111, P712 LEE C, 1988, PHYS REV B, V37, P785 LIU MTH, 1987, CHEM DIAZIRINES, V1 LIU MTH, 1987, CHEM DIAZIRINES, V2 LIU MTH, 1996, J AM CHEM SOC, V118, P8098 MARTIN N, 1998, CHEM REV, V98, P2527 MODARELLI DA, 1992, J AM CHEM SOC, V114, P7034 PIETRO WJ, 1982, J AM CHEM SOC, V104, P5039 PLATZ MS, 1994, RES CHEM INTERMEDIAT, V20, P175 SCHICK G, 1998, TETRAHEDRON, V54, P4283 WHITE WR, 1992, J ORG CHEM, V57, P2841; NR: 26; TC: 8; J9: J AM CHEM SOC; PG: 4; GA: 582NTSource type: Electronic(1
Oscillatiegedrag van het lasbad tijdens het TIG-lassen van de aluminiumlegering ALMgSi1
No full textIn dit afstudeerverslag worden de resultaten van een onderzoek beschreven, dat werd uitgevoerd naar het oscillatiegedrag van het smeltbad tijdens het TIG-lassen van aluminiumlegeringen, met name de AlMgSil-legering. Met het voortschrijden der techniek worden de normen en de kwaliteit, waaraan het produkt moet voldoen, voortdurend verhoogd. In de huidige produktie nemen automatische processen een steeds belangrijker plaats in. Voor het bewaken van de laskwaliteit is een sensorsysteem nodig. De in dit afstudeeronderzoek onderzochte oscillatieverschijnselen in het lasbad zouden de basis kunnen zijn voor een boogsensor. Uit de resultaten van het onderzoek blijkt, dat tijdens het lassen een oscillatie in het lasbad kan worden gegenereerd door het toedienen van stroompulsen, die periodiek op de normale lasstroom worden gesuperponeerd. De frequentie van de oscillatie kan worden bepaald door de spanningsvariatie van de lasboog, die een gevolg is van het oscillerende lasbad, te meten. Dit oscillatiesignaal is te meten en te analyseren door gebruik te maken van Fourier analyse. Uit de metingen komt naar voren dat de oscillatiefrequentie afhangt van de geometrie van het lasbad, zoals de lasbadbreedte, de lasbadvorm en de penetratie, maar daarnaast ook van de fysische eigenschappen van het vloeibare metaal, zoals de oppervlaktespanning en de dichtheid. Uit de metingen blijkt dat er een verband bestaat tussen de lasbadgrootte en de oscillatiefrequentic. In het algemeen geldt: hoe groter de lasbadbreedte, des te lager de oscillatiefrequentie. Ook moet onderscheid worden gemaakt tussen onvolledige en volledige penetratie (doorlassing). De oscillatiefrequentie bij onvolledige penetratie is aanzienlijk hoger, dan bij volledige penetratie. De frequentiesprong, die optreedt bij de overgang van onvolledige naar volledige penetratie biedt de mogelijkheid het oscillatiegedrag te benutten als basis voor een doorlassingssensor. Een dergelijke sensor is van groot belang bij veel lastoepassingen voor het behouden van een consistente kwaliteit, met name bij het lassen van pijpen.Welding Technology and Non-destructive TestingTechnische MateriaalwetenschappenMechanical, Maritime and Materials Engineerin
Seismic architecture, the wood alternative: seismic adaption of new architecture in the province of Groningen through the use of engineered wood
No full textThe earthquakes are induced due to the gas extraction that is taking place within the province and this comes with a lot of risks and problems. First of, the province and its structures are not prepared for earthquakes. Second, there is little to no knowledge about earthquake- proof building in The Netherlands. Third, next to the fact that new developments need to be earthquake-proof, they also need to suffice according to the latest sustainability legislations.Architecture and The Built EnvironmentArchitectural Engineering and Technolog
Laguerre-domain adaptive filters
No full textUsing a tapped-delay-line as an adaptive fitter, the complexity of the filter increases with increasing correlation length of input and reference signal. The author seeks simple adaptive filter structures such that for a long correlation length only a minor complexity of the filter is needed. He considers adaptive mechanisms governed by an exponentially weighted squared-error criterion. Laguerre-domain adaptive filters are introduced, which lead to a tapped IIR-filter line. These filters contain a discount factor as a free variable, which makes it possible to set the memory and the number of adaptive coefficients independently. Convergence properties of the proposed adaptive filters are discusse
Snoring Sound Production and Modelling: Acoustic Tube Modelling
No full textThe thesis project is aimed at designing an unobtrusive method to find the obstruction location and severity for patients who are not diagnosed with Obstructive sleep apnea, during their non-sedated sleep using simple recording devices within uncontrolled environment. Similar to speech generation, which is enabled by opening and closing of the vocal cords, the sound of snoring consists of a series of impulses caused by the rapid obstruction and reopening of the upper airway. By exploiting this similarity, we try to explain snoring sound production using synthesis techniques that has been applied to speech. A trial has been conducted to gain information on efficacy of different commercially available devices that are used to alleviate snoring problem. Sleeping sounds from this trial has been analyzed to find a method to find the effective device for each participant. Similar to speech analysis, Iterative Adaptive Inverse Filtering(IAIF) method has been used to find excitation flow and airway tract transfer functions of snoring sounds during the inhalation period. A model has been built using the Acoustic Tube Theory with the purpose of reflecting the physical realities of snoring sound production. Resulting transfer function spectra from acoustic tube modeling and IAIF has been compared using a gain-independent Itakura Spectral Distance Measure. It has been found that Linear Prediction is not suitable to directly determine the cross-sectional area of the upper airway from snoring sounds. An alternative method, using transmission line model with acoustic tube modeling has been found to produce transfer functions that are spectrally similar to transfer functions obtained from source filter models
An Internship as a Scenic Carpenter for the Movie Moontrap and Discussion on the Differences of Scenic Design for the Theatre and Film
No full textiii, 152 p.The author describes his internship constructing, and later doing the drafting work for sets for the movie Moontrap at a production shop in Troy, Michigan, and compares the movie experience with a second set construction experience at Kent State University in Ohio.Troy, Michigan
The Talk of Maine piece on expert birders, Wendy Howes of Wilton and Wally Sum
No full textThe Talk of Maine piece on expert birders, Wendy Howes of Wilton and Wally Summer of Canaan, who attempted to break the official American Birding Association Big Day record for Maine, set in 1993 by Lysle Brinker from the Belgrade area, and his team. The author accompanied the two birders as they traveled to numerous sites in Maine on a tight, pre-arranged schedule in late spring. They ultimately identified a total of 140 birds by sight and/or sound, falling short of the record, which was 163
Figures de témoins : Médiations littéraires et fictionnelles du génocide des Tutsi au Rwanda
No full textInternational audienceIn what way can the special position of witnesses from outside and witnesses of the aftermath that characterizes many writers who, in the space of twenty years, have devoted works to transmit the memory of the Tutsi genocide in Rwanda help redefine the notion of testimony, and above all, on what terms? To the extent that a media memory of the event (essentially in the form of images broadcast in the mass media in 1994) predates the work of writers, the idea is to question, from an ethical and aesthetic point of view, the potential of literary fiction to construct and transmit the memory of this event today. While updating some elements of a poethics [une poethique] of mediation, this paper also seeks to measure how, beyond the use of a style that can be described as iconic, certain literary works can attempt a true passing on of memory capable of crossing timeand boundaries between author and reader, others and myself, visible and invisible, conscious and unconscious, giving a new dimension to the issue of testimony
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