The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

Dimitrios Komilis - One of the best experts on this subject based on the ideXlab platform.

Constantinos Kletsas - One of the best experts on this subject based on the ideXlab platform.

Zongli Li - One of the best experts on this subject based on the ideXlab platform.

  • Study on Rock Mass Stability Effect of High Water Pressure Tunnels by Hydraulic Fracturing Failure
    Deep and Underground Excavations, 2010
    Co-Authors: Zongli Li
    Abstract:

    The hydraulic fracturing is one of common failure in hydraulic high water pressure tunnels. The process of hydraulic fracturing of high water pressure tunnel with different initial fracture length in tunnel inner wall is simulated using nonlinear FEM. The couple Effect of fracture inner water pressure with surrounding rock mass deformation is considered in the model. The fracture propagation process with increasing of tunnel inner water pressure is analyzed, its Effect on stress, displacement and plastic zone of tunnel surrounding rock mass is obtained. The results are compared with that obtained without considering existence of fracture water pressure. There are different results from two analysis method. The results show that only couple analysis can obtain relative authentic stress, displacement and plastic zone of tunnel surrounding rock mass, providing base data for correct Stability assessment of surrounding rock mass.

  • Study on Rock Mass Stability Effect of High Water Pressure Tunnels by Hydraulic Fracturing Failure
    Deep and Underground Excavations, 2010
    Co-Authors: Zongli Li
    Abstract:

    The hydraulic fracturing is one of common failure in hydraulic high water pressure tunnels. The process of hydraulic fracturing of high water pressure tunnel with different initial fracture length in tunnel inner wall is simulated using nonlinear FEM. The couple Effect of fracture inner water pressure with surrounding rock mass deformation is considered in the model. The fracture propagation process with increasing of tunnel inner water pressure is analyzed, its Effect on stress, displacement and plastic zone of tunnel surrounding rock mass is obtained. The results are compared with that obtained without considering existence of fracture water pressure. There are different results from two analysis method. The results show that only couple analysis can obtain relative authentic stress, displacement and plastic zone of tunnel surrounding rock mass, providing base data for correct Stability assessment of surrounding rock mass.

He Huiwen - One of the best experts on this subject based on the ideXlab platform.

  • A “one stop” thermal stabilizer, zinc arginine complex, with excellent comprehensive thermal Stability Effect on poly(vinyl chloride)
    Polymer Degradation and Stability, 2019
    Co-Authors: Shi Yanqin, Lu Songyan, Ma Meng, He Huiwen
    Abstract:

    Abstract A “one stop” thermal stabilizer, zinc arginine complex (Zn(Arg) 2 ), with excellent excellent initial whiteness, whiteness retention and long-term thermal Stability time for PVC, was conveniently synthesized in water solution. The successful synthesis of Zn(Arg) 2 was confirmed by FTIR, TGA and element analysis. Besides the longer Congo red and static thermal Stability time than nitrogen-containing thermal stabilizer reported, Zn(Arg) 2 also had better initial whiteness, whiteness retention and dynamic thermal Stability time showed by Congo red test, discoloration test and torque rheology test. Especially, the static thermal Stability time was more than 150 min, and the dynamic thermal Stability time reached 78 min. The excellent thermal Stability Effect of Zn(Arg) 2 on PVC was ascribed to the simultaneous possession of three mechanisms: absorbing HCl, replacing labile chlorine atoms and complexing ZnCl 2 . Moreover, PVC with Zn(Arg) 2 also showed excellent transmittance tested by vis-uv-near infrared spectrophotometer. Therefore, Zn(Arg) 2 is a “one stop” thermal stabilizer with good application prospects in transparent PVC.

D. A. Macleod - One of the best experts on this subject based on the ideXlab platform.

  • Wheelchair Stability: Effect of body position.
    Journal of rehabilitation research and development, 1995
    Co-Authors: R. L. Kirby, M. T. Sampson, F. A. V. Thoren, D. A. Macleod
    Abstract:

    When a wheelchair user reaches and leans, the static Stability decreases in the direction of the lean and increases in the opposite direction. The purpose of this study was to determine the extent of this Effect. We studied 21 nondisabled subjects in a representative wheelchair, measuring the static forward, rear, and lateral Stability on a tilting platform. Reaching and leaning away from the tip added Stability, with mean increases ranging from 9.1% to 124.3% of the neutral-position values, whereas reaching and leaning toward the tip reduced Stability, with mean decreases ranging from 25.2% to 52.3% (p < 0.0001). The Stability range ("away" minus "toward") varied from 52.4% to 149.5%. Reaching forward had a greater Effect on Stability than did reaching back or to the side. Wheelchair users with the ability to control their body positions can profoundly affect the Stability of their wheelchairs, a factor that should be considered in wheelchair selection and training.