The Subtropolis room-and-pillar mine extracts the Vanport Limestone(Allegheny Formation,Pennsylvanian System)near Petersburg,Ohio.Strata instability problems associated with excessive concentrations of lateral stress ...The Subtropolis room-and-pillar mine extracts the Vanport Limestone(Allegheny Formation,Pennsylvanian System)near Petersburg,Ohio.Strata instability problems associated with excessive concentrations of lateral stress caused the mine operator to implement a change in layout design.This mining method has been identified as a stress control layout and has been used by other underground stone mines in the past with varying degrees of success.Practical experience has shown that entry headings advance in the direction of the principal lateral stress,producing lower stress concentrations with better mining conditions.It is important to minimize stress concentrations along the mining front,so an arrowshaped advance is recommended.This technique advances more developments(headings)in a"good"direction and reduces developments(crosscuts)in the"bad direction."As is expected,the stress control layout enhances the potential for shear failures in crosscuts.It is,therefore,important to focus crosscut engineering interventions that either:(a)lower stress concentrations(for example,an arched roof)or(b)enhance strength of the strata containing the shears(for example,rock reinforcement).This study focuses on observing strata conditions on a regular basis and monitoring the response of these strata to changing geologic and mining conditions through 3D Dynamic LiDAR scans.展开更多
Background: Knee range of motion is an essential outcome measure following total knee arthroplasty and it is important to measure this outcome with a simple and accurate tool. Measurement from digital photographs coul...Background: Knee range of motion is an essential outcome measure following total knee arthroplasty and it is important to measure this outcome with a simple and accurate tool. Measurement from digital photographs could provide a superior clinical alternative to the common goniometer as devices for capturing digital photographs are becoming more accessible, measurement accuracy is assisted with the associated software and images can be saved and stored for later reference. This ability to store images with measurements could be particularly useful in research involving knee range of motion. This study evaluated the validity and reliability of a simple photographic measurement technique to measure knee flexion and extension of patients following knee arthroplasty.Methods: Knee flexion and extension of 38 subjects who had undergone total knee arthroplasty were assessed at the one year post-operative review with the digital technique and a universal goniometer as the criterion reference. Digital measurements were repeated one month later by the first assessor (intra-tester reliability) and another independent assessor (inter-tester reliability).Results: Validity: the digital technique was found to have a high level of agreement with the universal goniometer measurements (all MAD sion with almost perfect Intra-Class Correlations (Intra-tester;flexion 0.99, extension 0.96;inter-tester;flexion 0.97, extension 0.93).Conclusion: Measurement of knee range of motion from digital photographs can be used in routine clinical total knee arthroplasty follow-up instead of, or interchangeably with the universal goniometer.展开更多
文摘The Subtropolis room-and-pillar mine extracts the Vanport Limestone(Allegheny Formation,Pennsylvanian System)near Petersburg,Ohio.Strata instability problems associated with excessive concentrations of lateral stress caused the mine operator to implement a change in layout design.This mining method has been identified as a stress control layout and has been used by other underground stone mines in the past with varying degrees of success.Practical experience has shown that entry headings advance in the direction of the principal lateral stress,producing lower stress concentrations with better mining conditions.It is important to minimize stress concentrations along the mining front,so an arrowshaped advance is recommended.This technique advances more developments(headings)in a"good"direction and reduces developments(crosscuts)in the"bad direction."As is expected,the stress control layout enhances the potential for shear failures in crosscuts.It is,therefore,important to focus crosscut engineering interventions that either:(a)lower stress concentrations(for example,an arched roof)or(b)enhance strength of the strata containing the shears(for example,rock reinforcement).This study focuses on observing strata conditions on a regular basis and monitoring the response of these strata to changing geologic and mining conditions through 3D Dynamic LiDAR scans.
文摘Background: Knee range of motion is an essential outcome measure following total knee arthroplasty and it is important to measure this outcome with a simple and accurate tool. Measurement from digital photographs could provide a superior clinical alternative to the common goniometer as devices for capturing digital photographs are becoming more accessible, measurement accuracy is assisted with the associated software and images can be saved and stored for later reference. This ability to store images with measurements could be particularly useful in research involving knee range of motion. This study evaluated the validity and reliability of a simple photographic measurement technique to measure knee flexion and extension of patients following knee arthroplasty.Methods: Knee flexion and extension of 38 subjects who had undergone total knee arthroplasty were assessed at the one year post-operative review with the digital technique and a universal goniometer as the criterion reference. Digital measurements were repeated one month later by the first assessor (intra-tester reliability) and another independent assessor (inter-tester reliability).Results: Validity: the digital technique was found to have a high level of agreement with the universal goniometer measurements (all MAD sion with almost perfect Intra-Class Correlations (Intra-tester;flexion 0.99, extension 0.96;inter-tester;flexion 0.97, extension 0.93).Conclusion: Measurement of knee range of motion from digital photographs can be used in routine clinical total knee arthroplasty follow-up instead of, or interchangeably with the universal goniometer.
