Sökning: "small radius curves"

Hittade 5 avhandlingar innehållade orden small radius curves.

1. 1. Rail Corrugation Growth on Curves

   Författare :Peter Torstensson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; simulation; track and wheelset structural flexibility; small radius curves; short-pitch rail corrugation; dynamic vehicle–track interaction; test rig and field measurements; wear;

   Sammanfattning : Short-pitch rail corrugation that may develop on the low (inner) rail on small radius curves causes increased noise and vibration levels on railway networks worldwide. In lack of a generally applicable treatment, track authorities are forced to run expensive rail grinding programs on a regular basis to manage these problems. LÄS MER

3. 2. Rail Corrugation Growth on Curves

   Författare :Peter Torstensson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; short-pitch rail corrugation; rotating flexible wheelset model; small radius curves; prediction of long-term roughness growth; plastic deformation; non-Hertzian and non-steady wheel‒rail contact; wear; rutting corrugation;

   Sammanfattning : The development of periodic irregularities with distinct wavelengths (corrugation) on the low rail of small radius curves is studied through mathematical modelling, numerical simulations, field measurements and laboratory investigations. One year of monitoring of roughness on the low rail of a 120 m radius curve on the metro of Stockholm Public Transport (SL) showed severe growth of rail corrugation with wavelengths of about 5 cm and 8 cm. LÄS MER

4. 3. Investigations intothe crystallization of butyl paraben

   Författare :Huaiyu Yang; Åke Rasmuson; Mårten Behm; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Butyl paraben; Solubility; Thermodynamic; Activity; Activity coefficient; Second order correlation; Liquid-liquid phase separation; Ternary phase diagram; Nucleation; Induction time; Free energy; Interfacial energy; Nuclei critical radius Cooling crystallization; Evaporation crystallization; Chemical engineering; Kemiteknik;

   Sammanfattning : In thisproject, solubility of butyl paraben in 7 puresolvents and 5 ethanol aqueous solvents has been determined at from 1 ℃to 50 ℃. Thermodynamic properties of butyl paraben have been measured by DifferentialScanning Calorimetey. LÄS MER

5. 4. Influence of rail, wheel and track geometries on wheel and rail degradation

   Författare :Kalle Karttunen; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; track geometry; rolling contact; rail; railway; Rolling contact fatigue; maintenance; wear; wheel;

   Sammanfattning : For more efficient railway maintenance there is a need to increase the understanding of the influence of operational conditions on wheel and rail degradation. To this end, the chosen primary investigation strategy is to employ dynamic multibody simulations, where operational conditions are altered, to estimate the influence on material deterioration. LÄS MER

7. 5. Computational studies of DNA sequencing with graphene nanopores

   Författare :Lijun Liang; Yaoquan Tu; Alexander Lyubartsev; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DNA sequencing; Graphene nanopore; Molecular dynamic simulation; Kemi; Chemistry;

   Sammanfattning :     The aim of DNA sequencing is to obtain the order of DNA composition comprising the base pairs A (adenine) T (thymine), and C (cytosine) G (guanine). The fast development of DNA sequencing technology allows us to better understand the relationships among diseases, inheritance, and individuality. LÄS MER