Sökning: "blasting"

Visar resultat 21 - 25 av 45 avhandlingar innehållade ordet blasting.

  1. 21. Effects of confinement and initiation delay on fragmentation and waste rock compaction : Results from small scale tests

    Författare :Daniel Johansson; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gruv- och Berganläggningsteknik; Mining and Rock Engineering;

    Sammanfattning : Sub-level caving (SLC) is classified as a mass mining method and there is an increasing interest in its application worldwide and in a very wide range of geotechnical environments. Design of sub-level blasting rounds and optimization has become more important now when the sizes of the blasting rings have become larger. LÄS MER

  2. 22. Mehanics of Rock Fragmentation Static and Dynamic Laboratory Testing Applied to Aggregate Production

    Författare :Bahman Bohloli; Chalmers University of Technology; []
    Nyckelord :anisotropy; aggregates; rock failure; saturation; Brazilian test; dynamic tensile strength; Hopkinson pressure bar; fragmentation; rock fines; crushing;

    Sammanfattning : Knowing the strength properties of rocks is essential for calculating the stability of natural slopes, constructions in and on rock, excavations, blasting geometry, crushing, and drilling. When rock and rock masses are subjected to either dynamic or static loads, the tensile strength is determined by tests appropriate to the load type. LÄS MER

  3. 23. Models for analysis of young cast and sprayed concrete subjected to impact-type loads

    Författare :Lamis Ahmed; Anders Ansell; Richard Malm; Lennart Elfgren; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Young concrete · Shotcrete · Rock · Impact-type vibration · Finite element method · Fracture mechanics model · Crack width;

    Sammanfattning : The strive for a time-efficient construction process naturally put focus on the possibility of reducing the time of waiting between stages of construction, thereby minimizing the construction cost. If recently placed concrete, cast or sprayed, is exposed to impact vibrations at an early age while still in the process of hardening, damage that threatens the function of the hard concrete may occur. LÄS MER

  4. 24. Cleaning of metal artefacts using pulsed lasers

    Författare :Yang Sook Koh; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Manufacturing Systems Engineering; Produktionsutveckling;

    Sammanfattning : Preservation of cultural property in the form of historical artefacts for the future is an important interest in our society. The information which can be obtained from these materials is a valuable key to understand the past. LÄS MER

  5. 25. Characterising Dental Implant Surfaces by Topographical, Electrochemical, and Biomechanical Methods

    Författare :Johanna Löberg; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :Titanium dental implants; 3D-SEM; AFM; Mott-Schottky analysis; surface roughness parameters; biomechanics.;

    Sammanfattning : Replacement of extracted teeth by dental implants was first introduced in the 1950’s. From the beginning, threaded titanium implants with smooth surfaces were used. Later on, screw shaped implants with micro-scaled roughened surfaces were introduced showing bone ingrowth and improved in vivo and in vitro results and good long term stability. LÄS MER