105 research outputs found
A review on shear jamming
Jamming is a ubiquitous phenomenon that appears in many soft matter systems,
including granular materials, foams, colloidal suspensions, emulsions,
polymers, and cells -- when jamming occurs, the system undergoes a transition
from flow-like to solid-like states. Conventionally, the jamming transition
occurs when the system reaches a threshold jamming density under isotropic
compression, but recent studies reveal that jamming can also be induced by
shear. Shear jamming has attracted much interest in the context of
non-equilibrium phase transitions, mechanics and rheology of amorphous
materials. Here we review the phenomenology of shear jamming and its related
physics. We first describe basic observations obtained in experiments and
simulations, and results from theories. Shear jamming is then demonstrated as a
"bridge" that connects the rheology of athermal soft spheres and thermal hard
spheres. Based on a generalized jamming phase diagram, a universal description
is provided for shear jamming in frictionless and frictional systems. We
further review the isostaticity and criticality of the shear jamming
transition, and the elasticity of shear jammed solids. The broader relevance of
shear jamming is discussed, including its relation to other phenomena such as
shear hardening, dilatancy, fragility, and discrete shear thickening.Comment: 19 pages, 9 figure
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Application of Weighted Gene Co-expression Network Analysis for Data from Paired Design
Investigating how genes jointly affect complex human diseases is important, yet challenging. The network approach (e.g., weighted gene co-expression network analysis (WGCNA)) is a powerful tool. However, genomic data usually contain substantial batch effects, which could mask true genomic signals. Paired design is a powerful tool that can reduce batch effects. However, it is currently unclear how to appropriately apply WGCNA to genomic data from paired design. In this paper, we modified the current WGCNA pipeline to analyse high-throughput genomic data from paired design. We illustrated the modified WGCNA pipeline by analysing the miRNA dataset provided by Shiah et al. (2014), which contains forty oral squamous cell carcinoma (OSCC) specimens and their matched non-tumourous epithelial counterparts. OSCC is the sixth most common cancer worldwide. The modified WGCNA pipeline identified two sets of novel miRNAs associated with OSCC, in addition to the existing miRNAs reported by Shiah et al. (2014). Thus, this work will be of great interest to readers of various scientific disciplines, in particular, genetic and genomic scientists as well as medical scientists working on cancer
DETC2005-84367 DESIGN AND EXPERIMENTAL RESEARCH OF MAGNETO-RHEOLOGICAL FLUID FAN CLUTCH
ABSTRACT The fundamental principle of MR fluid fan clutch in transmitting torque is analyzed, in the meantime, a shear model of MR clutch is proposed; MR fluid fan clutch having simple, novel structure is designed and made; At the same time, on the basis of experiments, the characteristic of velocity regulating of the clutch is studied in detail. The experimental results indicate that, compared with the shearing rate, the change of magnetic fields has a tremendous influence on the speed regulating characteristic of a fan clutch, and output torque of fan clutch can satisfy demand of engine cooling fan
PoseHD: Boosting Human Detectors Using Human Pose Information
As most recently proposed methods for human detection have achieved a sufficiently high recall rate within a reasonable number of proposals, in this paper, we mainly focus on how to improve the precision rate of human detectors. In order to address the two main challenges in precision improvement, i.e., i) hard background instances and ii) redundant partial proposals, we propose the novel PoseHD framework, a top-down pose-based approach on the basis of an arbitrary state-of-the-art human detector. In our proposed PoseHD framework, we first make use of human pose estimation (in a batch manner) and present pose heatmap classification (by a convolutional neural network) to eliminate hard negatives by extracting the more detailed structural information; then, we utilize pose-based proposal clustering and reranking modules, filtering redundant partial proposals by comprehensively considering both holistic and part information. The experimental results on multiple pedestrian benchmark datasets validate that our proposed PoseHD framework can generally improve the overall performance of recent state-of-the-art human detectors (by 2-4% in both mAP and MR metrics). Moreover, our PoseHD framework can be easily extended to object detection with large-scale object part annotations. Finally, in this paper, we present extensive ablative analysis to compare our approach with these traditional bottom-up pose-based models and highlight the importance of our framework design decisions
Progress in NMR-based metabolomics of Catharanthus roseus
Metabolomics has been rapidly developed as an important field in plant sciences and natural products chemistry. As the only natural source for a diversity of monoterpenoid indole alkaloids (MIAs), especially the low-abundance antitumor agents vinblastine and vincristine, Catharanthus roseus is highly valued and has been studied extensively as a model for medicinal plants improvement. Due to multistep enzymatic biosynthesis and complex regulation, genetic modification in the MIA pathway has resulted in complicated changes of both secondary and primary metabolism in C. roseus, affecting not only the MIA pathway but also other pathways. Research at the metabolic level is necessary to increase knowledge on the genetic regulation of the whole metabolic network connected to MIA biosynthesis. Nuclear magnetic resonance (NMR) is a very suitable and powerful complementary technique for the identification and quantification of metabolites in the plant matrix. NMR-based metabolomics has been used in studies of C. roseus for pathway elucidation, understanding stress responses, classification among different cultivars, safety and quality controls of transgenic plants, cross talk between pathways, and diversion of carbon fluxes, with the aim of fully unravelling MIA biosynthesis, its regulation and the function of the alkaloids in the plant from a systems biology point of view
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