Effects of inter-particle friction on the critical state behavior of granular materials: a numerical study

Critical state soil mechanics (CSSM) gives a theoretical framework for soil modelling. This paper investigates the effect of inter-particle friction on the critical state behavior of DEM assemblies with grading representative of a real soil. It is found that the angle of shearing resistance at the critical state increases with increasing inter-particle friction (µ) and in void ratio (e) vs logarithmic mean effective stress (log(p’)) space the critical state locii have higher e values when µ is higher. An atypical CSL in e-logp’ space that deviates from experimental observations and the classical CSSM behavior was observed when µ = 0.5. Micro-scale analyses show that this can be attributed to the emergence of a higher number of floating particles due to the increasing self-stability of strong force chains with increasing inter-particle friction. This study recommends the use of inter-particle friction lower than 0.5 in DEM simulations of element testing in soil mechanics

Common variants in SOX-2 and congenital cataract genes contribute to age-related nuclear cataract

Nuclear cataract is the most common type of age-related cataract and a leading cause of blindness worldwide. Age-related nuclear cataract is heritable (h2 = 0.48), but little is known about specific genetic factors underlying this condition. Here we report findings from the largest to date multi-ethnic meta-analysis of genome-wide association studies (discovery cohort N = 14,151 and replication N = 5299) of the International Cataract Genetics Consortium. We confirmed the known genetic association of CRYAA (rs7278468, P = 2.8 × 10−16) with nuclear cataract and identified five new loci associated with this disease: SOX2-OT (rs9842371, P = 1.7 × 1

Turnover in information systems development projects - Managing forgetting

PACIS 2008 - 12th Pacific Asia Conference on Information Systems: Leveraging ICT for Resilient Organizations and Sustainable Growth in the Asia Pacific Regio

Effects of inter-particle friction on the critical state behavior of granular materials: a numerical study

Critical state soil mechanics (CSSM) gives a theoretical framework for soil modelling. This paper investigates the effect of inter-particle friction on the critical state behavior of DEM assemblies with grading representative of a real soil. It is found that the angle of shearing resistance at the critical state increases with increasing inter-particle friction (µ) and in void ratio (e) vs logarithmic mean effective stress (log(p’)) space the critical state locii have higher e values when µ is higher. An atypical CSL in e-logp’ space that deviates from experimental observations and the classical CSSM behavior was observed when µ = 0.5. Micro-scale analyses show that this can be attributed to the emergence of a higher number of floating particles due to the increasing self-stability of strong force chains with increasing inter-particle friction. This study recommends the use of inter-particle friction lower than 0.5 in DEM simulations of element testing in soil mechanics

Root systems of native shrubs and trees in Hong Kong and their effects on enhancing slope stability

Objectives: Mechanical reinforcement by plant roots is believed to have an important role in stabilizing highly saturated slopes against shallow failure. In this study, the root system of four Hong Kong native shrubs (Rhodomyrtus tomentosa and Melastoma sanguineum) and trees (Schefflera heptaphylla and Reevesia thyrsoidea) with height that ranged between 1 and 1.5 m was sampled and their characteristics were studied. Methods: The distribution of roots and root area ratio (RAR) with depth, relationship between root tensile strength (Tr) and root diameter (d), and also the variation of root cohesion (cr) with depth of the four species were investigated and statistically compared. Results: Roots of the studied trees were found to extend deeper into the ground (up to 0.8 m) as compared to the shrubs (up to 0.4 m). RAR lies between 0.03 and 0.14% for the top 0.1 m soil and decreased with depth. The obtained Tr–d relationship of all the studied species fell into the same order as compared to some commonly reported European species. Besides, conventionally adopted power relationship between Tr and d was confirmed to be applicable for the studied species. The variation of root cohesion with depth was investigated for each species. Root cohesion of less than 1.5 kPa was evaluated for even the top 0.2 m soil when roots with a diameter that ranged only between 1 and 10 mm were considered. The contribution of roots to slope stability was studied on infinite slopes with and without vegetation under two hydrological scenarios (dry and wet slopes). Conclusions and Implications: It was found that the studied young vegetation can bring an unsafe slope to marginal safety (factor of safety slightly larger than unity). Moreover, the studied tree species did not outperform the shrubs

Phonological processing in Chinese-English bilingual biscriptals: An fMRI study

10.1016/j.neuroimage.2005.06.057NeuroImage283579-587NEIM

Phonological processing in Chinese-english bilingual biscriptals: An fMri study

2004 IEEE International Workshop on Biomedical Circuits and SystemsS3.1-1