Sökning: "Rotating Disc"

Visar resultat 11 - 15 av 20 avhandlingar innehållade orden Rotating Disc.

1. 11. Lubricating grease Experiments and modeling of wall-bounded- and free-surface flows

   Författare :Jinxia Li; Arto Lehtovaara; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

   Sammanfattning : Lubricating grease is commonly applied to lubricate e.g. rolling bearings, sealsand gears. Grease has some clear advantages over lubricating oil: it is a semisolidmaterial, which prevents it from flowing/ leaking out from the bearingsystem and gives it sealing properties, and it also protects the system fromcontaminants and corrosion. LÄS MER

3. 12. Numerical Studies of Extragalactic Objects. Analysis of mmVLBI Observations and Simulations of Barred Spiral Galaxies

   Författare :Mikael Lerner; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quasars; galactic dynamics; barred galaxies; N-body simulations; VLBI; model fitting;

   Sammanfattning : Numerical studies related to high-frequency VLBI observations of quasars and dynamics of barred spiral galaxies have been performed. Data from a global 100 GHz VLBI experiment has been reduced and a radio image of the quasar 3C 446 with the highest resolution achieved to date has been produced. LÄS MER

4. 13. Attenuation of hand-held machine vibrations. Application of non-linear tuned vibration absorber

   Författare :Hans Lindell; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Impact machine; Hand-arm vibration; High frequency vibration; ATVA; Nonlinear tuned vibration absorber; White finger; HAVS; Transient vibration; Auto Tuned Vibration Absorber; Vibration dynamics; ISO 5349;

   Sammanfattning : Vibration injury in the hand-arm system from vibrating hand-held machines is one of the most common occupational health injuries and causes severe and often chronic nerve and vascular injuries to the operator. The objective with this study is to contribute to reduce hand-arm vibration injuries, first by developing methods of redesigning machines that will lower their vibration level and second to study how high frequency vibrations (HFV) above 1250 Hz effect the finger tissue which are not included in the current standard for risk evaluation. LÄS MER

5. 14. Inverse Identification of Dynamic Wheel-rail Contact Forces

   Författare :Hamed Ronasi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inverse problems; sensitivity; optimization; regularization; railway mechanics; input estimation; load identification;

   Sammanfattning : Accurate evaluation of contact forces between wheel and rail is essential in the assessmentof vehicle performance and to predict consequences of dynamic vehicle-track interaction.As the contact forces can not be measured directly in the field, one common approachis to measure the strain or acceleration at various positions on a wheel or wheel axle. LÄS MER

7. 15. Molecular gas and ionizing radiation in star-forming galaxies

   Författare :Johannes Puschnig; Matthew Hayes; Göran Östlin; Amélie Saintonge; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; astrophysics; galaxies; star formation; starburst; interstellar medium; Lyman continuum; Lyman alpha; reionization; gravitational instability; molecular gas; clump formation; Astronomy; astronomi;

   Sammanfattning : In cosmic history, some of the major changes such as reionization were driven by baryons (i.e. the stars and gas in galaxies), despite the fact that they contribute only few percent to the total mass-energy budget in the Universe. LÄS MER