Statsoft Statistica 12 REPACK Crack 11
CLICK HERE >>> https://urlin.us/2tok19
Operation of the software typically involves loading a table of data and applying statistical functions from pull-down menus or (in versions starting from 9.0) from the ribbon bar. The menus then prompt for the variables to be included and the type of analysis required. It is not necessary to type command prompts. Each analysis may include graphical or tabular output and is stored in a separate workbook.
SigmaStat is an easy-to-use, wizard-based statistical software package designed to guide users through every step of the analysis and perform powerful statistical analysis without being a statistical expert. SigmaStat is tailored to the areas of life science and medicalresearch, but can be a valuable product to scientists in many fields.
Retrieval examinations and biomechanical simulation revealed that primary micromotions initiated fretting within the modular tapered neck connection. A continuous abrasion and repassivation process with a subsequent cold welding at the titanium alloy modular interface. Surface layers of 10 - 30 μm titanium oxide were observed. Surface cracks caused by fretting or fretting corrosion finally lead to fatigue fracture of the titanium alloy modular neck adapters. Neck adapters made of cobalt chrome alloy show significantly reduced micromotions especially in case of contaminated cone connection. With a cobalt-chromium neck the micromotions can be reduced by a factor of 3 compared to the titanium neck. The incidence of fretting corrosion was also substantially lower with the cobalt-chromium neck configuration.
The stem was combined with neck adapters with 130 CCD angle, embedded in bone cement (Palacos R, Heraeus Medical GmbH Wehrheim, Germany) and tested on a servohydraulic testing machine (MTS 850.2, MTS Systems Corporation Eden Prairie MN, USA). A sinusoidal axial force between 50 and 2500 N was applied via a ceramic head with neck length L at a frequency of 1 Hz for 2000 cycles to measure the relative displacement between neck adapter and stem with regard to irreversible settling and micromotions. A statistical analysis was performed to distinguish between independent groups (clean and particle contaminated joining area) (paired Student's t test) for both neck adapter materials (SPSS 15.0).
Metallographic analyses showed that microcracks developed on the surface of the cone in the clamping range (Figure 9). It appears that these microcracks induced the fatigue crack which finally led to the implant failure. Microcracks were analyzed using a scanning electron microscope. Figure 9 shows a potential micro crack in an area where fretting marks can be seen on the surface of the cone.
The study suggests the following hypothesis as to the cause of the damage. Fretting occurs when two surfaces in contact experience small amplitude oscillary relative motion; damage is induced on the fretting region. If the fretting fatigue strength of the material is exceeded, microcracks develope on the surface. In addition, tribochemically activated particles can discharge their content from the surface. These particles react with oxygen spontaneously, thus leading to fretting corrosion.
The surface damage of the titanium alloy adapters caused by the microcracks or by corrosive deterioration accelerates the propagation of cracks by the cyclic loads bringing about the dynamic fatigue failure of the adapters. Micro-movements cause fretting in the cone connection. They can be increased by contamination of the cone connection through tissue or other particles intraoperatively. To anticipate this process any contamination of the connection should be avoided and the components dried before assembling. For this purpose abrasion-resistant cleaning rods are supplied together with the implants.
The authors would like to thank Elisa Hoenig, M.Sc. and Michael M. Morlock, Ph.D. for the examination of micromotions in the neck adapter/stem interface, Thomas Hermle, M.Sc., MBA for the performance of the survival-failure analysis