Past studies on soil nailing have a common assumption that a soil nail could be simplified as a single material solid cylinder. However, a soil nail is a composite material and consisted of the following basic components: steel bars, cement grout, PVC centralizers, steel couplers, and a plastic hose, etc. They are combined and work together to keep the fundamental functions in soil reinforcement. Since these components are made by various constituent materials, the physical and mechanical properties of them are greatly different, making the deformations through soil nail diverse. The different deformations could be incompatible, which has significant effects on the soil nail integrity and performance due to the intrinsically existing vulnerable areas. One critical issue is the key component cement grout sleeve, functioning as the adhesive to transfer stress between the ground and steel bar, may encounter tensile failure on the out-layer surface or along the interface between steel bar and itself. The consequence would be cracking and detachment of cement grout and then malfunction of soil nails. Therefore, it is of great importance to examine the mechanical behavior of soil nails by taking into account the behavior of the different components. In this research extensive laboratory tests have been carried out to examine and quantify the mechanical properties of soil nail’s each component as well as their simple combinations. Based on this, a series of physical modeling of soil nail in tension and bending tests are designed to simulate the deformation of soil nail under loading. The characteristics of soil nail’s overall behavior and cracking initiation/propagation in cement grout are observed and interpreted. Besides, two soil nail’s component replacement trials based on the conventional design are conducted with attempt to enhance the overall soil nail strength and facilitate the installation procedure. A new concrete mix design with fine aggregates (sands) is adopted to substitute the neat cement grout for minimizing the local failure in cement column. Optimum sand ratio which is sound for postponing the cracking is evaluated as well. Another trial is the application of hollow core steel bar in place of the solid one. Compared to the traditional drill-and-grout soil nailing method, this new technology has advantages of fewer installation steps through a self-grout method. Similar laboratory tests are done to exam the impact on soil nail’s capacity from this change and preliminarily evaluate the feasibility of using of hollow core steel bar in practice. / published_or_final_version / Civil Engineering / Master / Master of Philosophy

MMed (Orthopaedic Surgery), Faculty of Health Sciences, University of the Witwatersrand / Intramedullary nail insertion into a fractured bone allows stabilisation of the fracture with minimal intervention through the zone of injured tissue. This study aimed to assess whether intramedullary nailing of the forearm bones (radius and/or ulna) is a safe and effective form of management of these often complex fractures. A prospective case series was followed from presentation to fracture union. Between April 2006 and February 2008, 21 patients were enrolled in the study. The fracture union rate was high and complication rate was low. There was no increased risk of sepsis. The use of intramedullary nailing for diaphyseal fractures was successful but metaphyseal fractures, particularly with shortening, may be problematic. The use of intramedullary nailing for radius/ulna fractures is safe and effective, however the widespread use of this technique may be limited by the cost of the implant.

No description available.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 211-217). Also available in electronic version.

Each year, thousands of femoral and tibial internal fracture repairs are performed by orthopedic surgeons in the United States. Internal fixation of long bones using intramedullary nails (IMN) has decreased incidence of non-union, allowed shorter hospitalization time, and earlier weight bearing for the patient compared to other fixation methods. Orthopedic surgeons have expressed that one of the most difficult parts of this intramedullary nailing of long bones, is locating and drilling the interlocking screw holes. IMN interlocking requires the surgeon to locate the holes in the nail, center the drill, and advance the bit through the bone to meet them. Many novel procedures and devices have been developed to assist the surgeon in distal locking of intramedullary nails, but have some disadvantages. These can include the need for extensive x-ray exposure, expensive x-ray equipment, high power consumption, active electronics in vivo, soft tissue damage, which all lead to inaccurate screw placement. For these reasons, a new prototype device for locating and drilling IMN distal interlocking holes has been developed. This prototype device uses magnetic sensors to locate a permanent magnet placed at a know distance from the IMN interlocking hole. A drill sleeve may be attached to the targeting sensors so that when they are aligned with the target magnet, the drill sleeve is aligned with the axis of the interlocking hole to be drilled. This new prototype device has significant advantages over existing devices, including the following. It has no active or passive electronics in vivo, no x-ray imaging is needed for targeting, while allowing real time feedback of alignment. It is a percutaneous technique, which can be adapted for use with existing IMN's. The new prototype also has low power requirements allowing battery operation, a single target magnet with unique axisymmetric field and novel magnet orientation, and adjustable sensitivity. Additionally, the new device allows visual, audible, or tactile positioning feedback. This prototype magnetic targeting device can improve orthopedic surgeons' ability to target and drill distal IMN interlocking screw holes. This device may allow shorter surgery, decreased x-ray exposure, and fewer complications for the surgeon and patient. / Master of Science

M.Med., Orthopaedic Surgery, Faculty of Health Sciences, University of the Witwatersrand, 2010

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xii, 86 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 80-82).

Στην παρούσα εργασία μελετάμε την εφαρμογή ενός ρομποτικού βραχίονα στην διαδικασία της ενδομυελικής ήλωσης, η οποία είναι η συνήθης τεχνική που χρησιμοποιείται σε διαδικασίες ρουτίνας, για την ανακατασκευή των καταγμάτων του μηριαίου οστού και της κνήμης. Πιο συγκεκριμένα, αρχικά γίνεται προσπάθεια ανίχνευσης των οπών του ενδομυελικού ήλου, οι οποίες λαμβάνονται μέσω ενός C-arm, στον τρισδιάστατο χώρο. Στις οπές αυτές τοποθετούνται ειδικά μεταλλικά καρφιά που στοχεύουν στη συγκράτηση του ενδομυελικού ήλου με το οστό του ασθενούς. Από τη στιγμή που έχει προσδιοριστεί ο άξονας που συνδέει δύο οπές στον ήλο, οδηγείται ρομποτικός βραχίονας προκειμένου να τρυπηθεί το οστό του ασθενούς, κατά μήκος αυτού του άξονα. Η όλη διαδικασία μελετάται μέσω προσομοίωσης στην παρούσα εργασία. / The summary is not available.

The subject of this thesis is the design of a local road cut off in the resort Hálův mlýn located in the cadastral of municipality Lažánky, Brno-venkov district, South Moravian Region. The thesis contains static calculation and design documentation.

No description available.