84 research outputs found
Catalytic oxidation of soot: Potential for reduction of diesel particulate emissions
No full textApplied Science
Relating Robotic- and Ultrasound-Based Techniques for Characterizing the Effects of Changes in Muscle Properties Following Stroke
No full textBackground: Following a stroke, muscle tissue is prone to atrophy, decreased fascicle length, loss of sarcomeres, and a possible enhancement of collagenous extracellular matrix. Decreased fascicle length associated with a loss of sarcomeres, and a possible enhancement of collagenous extracellular matrix are thought to result in an increase in passive stiffness and therefore contribute to movement dysfunction. Valid and reliable in-vivo, non-invasive, and cost-effective assessment of muscle stiffness eludes conventional rehabilitation practice. Ultrasound-based shear wave elastography is a new measurement technique; capable of measuring muscle elasticity however evidence for criterion validity is lacking for paretic muscle in individuals with stroke. Thus our aim was to (1) to investigate the concurrent/criterion validity of shear wave elastography, for estimating the passive stiffness of biceps, with an established robotic perturbation metric for quantifying joint stiffness in individuals with severe chronic stroke and (2) confirm that both metrics were capable of detecting a difference between paretic and non-paretic arms. Methods: Passive elbow stiffness during extension was quantified using a robotic device that administered a controlled elbow joint extension perturbation. Passive biceps elasticity was quantified using a conventional ultrasoundbased shear wave elastography. Stiffness values were extracted at 7 elbow joint positions in the paretic and non-paretic arms of 10 stroke patients. Sophisticated post-processing of muscle EMG was administered to confirm muscle quiescence during all measurements. Results: There was a significant correlation between passive biceps elasticity and joint stiffness during elbow extension with a strengthening relationship approaching end range extension. Both metrics identified increased passive stiffness with elbow extension joint stiffness 2.26 times greater and biceps stiffness 1.19 times greater on the paretic side. Conclusion: Shear wave elastography appears to be a valid and viable tool for the estimation of muscle stiffness in individuals with severe chronic stroke. The ability to quantify muscle elasticity will expand the depth and breadth of the clinician’s evaluation and offer a new target for therapeutic intervention.Mechanical, Maritime and Materials EngineeringBiomedical Engineerin
Copper catalysis for particulate removal from diesel exhaust gas. Copper fuel additives in combination with copper coatings.
No full textThe formation of carbon surface oxygen complexes by oxygen and ozone. The effect of transition metal oxides
No full text
De hydroformylering van propeen
No full textDocument(en) uit de collectie Chemische ProcestechnologieDelftChemTechApplied Science
Onderzoek van 2-dimensionale stromingen m.b.v. het hele-Shaw spleetmodel en een regensimulator
No full textTengevolge van de regenval heeft de waterstand de neiging omhoog te komen. Andere factoren van watertoevoer zijn o.a. kwel, irrigatiewater, doorspoelwater, sneeuwval. Zij zijn t.o.v. de regen in kwantitatief opzicht minder belangrijk en worden verder verwaarloosd. De gevallen neerslag moet op lange termijn meer afgevoerd worden om een constant polderpeil te waarborgen. Dit afvoeren geschiedt in diepe polders (b.v. droogmakerijen) altijd door de gemalen. Als het polderpeil (= grondwaterstand) hoger ligt dan het ontvangende water (boezem, rivier of zee) is het mogelijk om op natuurlijke wijze (= d.m.v. zwaartekracht) te lozen. In dit verslag wordt in het midden gelaten hoe het water geloosd wordt. Er wordt echter wel vanuit gegaan dat afvoer zodanig is dat er een constant slootwaterpeil gehandhaafd blijft. De regen, die op het maaiveld valt, zakt vertikaal tussen de korrels door naar beneden tot het grondwater, dat daardoor zal stijgen boven het constante slootpeil. Tengevolge van dit niveauverschil ontstaat er een grondwaterstroming naar de sloot. De korrelstructuur heeft een remmende invloed op deze stroming en destemeer naarmate de doorlatendheid van de grond kleiner is en/of de af te leggen afstand voor een waterdeeltje groter is. In evenwichtstoestand bij constante neerslag ontstaat er zodoende een constant niveauverschil tussen grond- en slootwater en deze is groter naarmate de afstand tot de sloot groter en/of de doorlatendheid kleiner is.Hydraulic EngineeringCivil Engineering and Geoscience
De industriële zuivering van caprolactam
No full textDocument(en) uit de collectie Chemische Procestechnologie.DelftChemTechApplied Science
Critical Flow Calculations of Compressible Non-Ideal Fluids Based on an EOS
No full textThis thesis comprises the results of a graduation project which has been executed at the Laboratory of Applied Thermodynamics and Phase Equilibria, faculty of Chemical Engineering and Materials Science, Delft University of Technology (DUT). It is a part of a research project being carried out by Dr. L.Z. Boshkov and prof. J. de Swaan Arons; the project is financially sponsored by the Royal Dutch Shell Company. The aim of the research project is to present a systematic approach to the modelling and sizing of safety relief valves. Pressure or safety relief valves are routinely placed on chemical reactors and pressure vessels handling gases or liquids to protect the equipment against pressure build-up. Because the modelling still causes non-trivial tasks for chemical engineers, the research project was started to structurize the problems. In this work the results will be discussed with respect to t the critical flow of both one- and two-phase flow of non-ideal fluids through PRV 's at given stagnation states using an EOS. The results in this thesis are calculated for the non-ideal RK-fluid, however, the derived theories are presented as general as possible which makes extension to other EOS possible. The results in this thesis are calculated for the non-ideal RK-fluid, however, the derived theories are presented as general as possible which makes extension to other EOS possible. When concerning the one-phase flow calculations for the RK-fluid, one can conclude that the obtained results are equivalent to published results [Leung & Epstein, 1988]. In contrast to the latter published results, in this work an analytical maximization criterium is applied which provides more insight into the process equation which has to be used. Another important conclusion is that in this thesis the thermodynamic limits of one-phase critical flow are described and calculated. Both the spinodal and the saturation curve are indicated in the presented diagrams. The approach has been used to develop a new kind of phase diagrams: the critical flow phase diagrams (CFPD). This CFPD can be applied as an engineering tool in PRV design studies. With respect to the two-phase critical flow calculations, the well-known HEM have been worked out for non-ideal fluids using an EOS for the first time. Again an analytical maximization criterium has been applied to obtain the results. The results in this work are in a preliminary stage but one can conclude that they are in qualitatively correspondence with published data. On the face on it, the developed model can relatively easy be extended to critical flow processes which start in the one-phase region but have a maximum in mass flux in the two-phase region, and to processes concerning binary mixtures or even multi-component systems. When these extensions are succeeded, for the first time a general theory will have been derived that covers the entire range of initial vessel temperatures and pressures.Applied SciencesChemical Technology and Materials ScienceApplied Thermodynamics and Phase Equilibri
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