Articles tagged with Dislocation
Researchers found that even three-nanometer-sized nanocrystals can suffer from dislocation-mediated plastic deformation when subjected to stress. This challenges the long-held assumption that ultrafine nanocrystals are defect-free.
Older patients with shoulder dislocations are more likely to experience rotator cuff tears due to weakened tissues, but less likely to recur compared to younger patients. Prompt evaluation and management by a specialist or orthopedic surgeon is crucial for optimal outcomes.
A study by University of Iowa researchers found that morbidly obese patients experience higher dislocation rates due to increased thigh girth, which creates hip instability. The team suggests surgeons modify procedures and consider new implant designs to minimize this risk.
Young athletes playing contact sports are at high risk of recurring shoulder instability injuries, often caused by traumatic contact injuries such as force or falling on an outstretched arm. Symptoms include pain, instability, and weakness in the affected shoulder.
Researchers at the University of Pennsylvania have gained insight into how phase change materials switch between states, a key step towards creating universal memory storage devices. By using nanowires, they were able to observe the phase change in real-time and discovered a new mechanism that could lead to more efficient memory devices.
Traumatic shoulder injuries often contain secondary injuries that can compromise treatment effectiveness. New protocols aim to identify these injuries, leading to improved patient outcomes. The protocols, awarded the 2012 Gold Medal, will be presented at the 2012 ARRS Annual Meeting.
New research finds that shorter hospital stays for total knee replacement (TKR) patients are associated with increased risk of revision and mortality. Outpatient groups had lower costs at 2 years, but higher mortality and dislocation rates.
Researchers at Case Western Reserve University have imaged atomic structural changes in sapphires that control their properties. These changes, called dislocations, involve small rearrangements of aluminum atoms and can affect the material's electrical, chemical, and magnetic properties as well as its strength and durability.
Researchers found a new mechanism controlling peak strength in nanostructured metals by observing organized dislocation patterns in 3-D atomic simulations. The pattern, governed by nucleation, dictates the metal's strength or weakness.
A study by American Academy of Orthopaedic Surgeons reveals that majority of shoulder dislocations occur during sports and recreational activities, with young males being at higher risk. Elderly women also show a high rate of shoulder dislocation, especially among those aged 80 to 90 years old.
A study released by the American Orthopaedic Society for Sports Medicine found that arthroscopic surgery is successful in young, athletic patients with a high failure rate of conservative methods. The study evaluated 39 patients over an average of 11.7 years and found excellent shoulder function and activity level maintenance.
Materials scientists have developed a theoretical model to predict the strength of metals at the nanoscale. Their study found that metal strengths saturate at around 10-50 nanometers diameter due to temperature and strain rate sensitivity.
Researchers found that compressing nanoscale nickel pillars drives out dislocations, producing a perfect crystal and increasing strength. The process, called mechanical annealing, reduces dislocation density by 15 orders of magnitude, making small structures stronger than expected.
Researchers in France have successfully modeled the defects responsible for deformation in the Earth's mantle layer, a 2900-kilometer-deep region that has long puzzled geophysicists. By studying dislocations at the atomic scale, they gained insights into the layer's deformation and its effects on convection movements within the mantle.
A study found that obesity increases risk of infection and dislocations in women after total hip replacements. Obese women also reported lower functional outcomes and satisfaction due to a higher incidence of complications. The study suggests that surgeons should counsel obese female patients before surgery.
Researchers have developed a new method to study materials under extreme conditions, revealing the evolution of high-strain-rate plasticity. The technique combines molecular dynamics simulations with experimental data from laser experiments, providing insights into metal deformation and material strength.
Researchers discovered that nanoscale materials can withstand near-theoretical shear stresses even with high defect densities, challenging traditional concepts of plastic deformation. Using a unique experimental setup, they correlated load-displacement measurements with individual video frames to study the sequence of events.
Researchers use X-ray microbeam to measure stresses and strains in deformed metal, confirming a 20-year-old theory. The study provides quantitative data to support computer models of mechanical stress, offering new insights into the behavior of metals.
Researchers at Lawrence Livermore National Laboratory discovered that three line defects in the crystal structure of metals create a stronger bond than when only two dislocations intersect. This finding has significant implications for hardening metals and could be applied to various industries, including construction and manufacturing.
The thesis proposes a measurement system that uses magnetic domains as internal sensors to determine microstructure variations in steels. This method allows for the quantitative investigation of dislocation density, grain boundaries, and precipitates, opening up new technological possibilities in magnetic non-destructive testing.
Scientists have identified a prominent way in which nanocrystalline metals change shape by using dark-field imaging techniques. Researchers report that at very small dimensions, grain boundaries themselves move and slide past one another to allow deformation.
Johns Hopkins researchers create ultra-strong copper that retains its ductility by manipulating the metal's microstructure through a process involving liquid nitrogen, rolling, and controlled heating. The resulting material exhibits enhanced strength without sacrificing flexibility.
Using a powerful supercomputer, researchers simulated materials' strength and behavior, gaining insights into fracture, work hardening, and customized properties. The study enables better understanding of earthquakes and design of new materials to resist brittle fracture.
Researchers discovered strontium titanate deforms plastically at low stresses and temperatures, contrary to its brittle nature. Detailed analysis reveals the existence of different dislocation core structures, suggesting potential applications in forming or enhancing ceramic properties.
Researchers identified imperfections' preferred location on twin grain boundaries, leading to new strategies to control material properties. Grain size plays a role only when plastic deformation begins, with little effect afterwards.
Scientists have found that deformation can bypass the sound barrier in materials, leading to supersonic dislocations. These findings challenge conventional wisdom and open up new avenues for understanding high-speed deformation in engineering materials.
Researchers at the Max Planck Institute of Metals Research have identified two temperature-dependent mechanisms controlling the brittle-to-ductile transition in materials. Dislocation mobility dominates fracture toughness above a characteristic temperature, whereas dislocation nucleation controls fracture toughness below this temperature.
Researchers are developing atomistic simulations to predict macroscopic deformation behavior from atomic scale processes. These simulations use discrete dislocation dynamic methods, feeding mobility laws and short-range defect interactions into continuum models.