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The quasi-static and dynamic bending responses of the human mid-lower cervical spine were determined using cadaver intervertebral joints fixed at the base to a six-axis load cell. Flexion bending moment was applied to the superior end of the specimen using an electrohydraulic piston. Each specimen was tested under three cycles of quasi-static load-unload and one high-speed dynamic load. A total of five specimens were included in this study. The maximum intervertebral rotation ranged from 11.0 to 15.4 deg for quasi-static tests and from 22.9 to 34.4 deg for dynamic tests. The resulting peak moments at the center of the intervertebral joint ranged from 3.8 to 6.9 Nm for quasi-static tests and from 14.0 to 31.8 Nm for dynamic tests. The quasi-static stiffness ranged from 0.80 to 1.35 Nm/deg with a mean of 1.03 Nm/deg ([+ or -]0.11 Nm/deg). The dynamic stiffness ranged from 1.08 to 2.00 Nm/deg with a mean of 1.50 Nm/deg ([+ or -]0.17 Nm/deg). The differences between the two stiffnesses were statistically significant (p < 0.01). Exponential functions were derived to describe the quasi-static and dynamic moment-rotation responses. These results provide input data for lumped-parameter models and validation data for finite element models to better investigate the biomechanics of the human cervical spine.

General formulas to produce failure were derived from acantilever beam-column with one end built-in and the free end subjected to an oblique-eccentric arbitrary concentrated force. The solutions for uniform safe conditions for material strength failure and buckling failure were given in terms of four dimensionless numbers including the Secant formula used for axialeccentric buckling and Euler's classic buckling formula.

By injecting cryogenic deuterium pellets into H-mode plasmas with edge localized modes (ELMs) from the low-field side (LFS) on EAST tokamak, the impact of these pellets on the edge plasma can be investigated. In some cases of pellet injection (PI), the intermediate phase (I-phase), i.e, the dithering-like cycles, have been observed. Experiments show that during one dithering-like cycle, three phases can be distinguished, which are closely related to the variations in the pedestal density profiles and density gradient after PI. Phase 1 is characterized by rapid particle loss and a density pedestal crash, phase 2 has a relatively low density gradient and enhanced edge density fluctuation and phase 3 corresponds to the relatively fast recovery of the density pedestal and reduced edge density fluctuation. Through an experimental analysis, it is shown that the plasma will enter the I-phase when the edge line-averaged density increases beyond a certain threshold value after PI. H-I-H transitions are more likely to be observed when the edge line-averaged density is greater than the core line-averaged density. [ABSTRACT FROM AUTHOR]

Because of the increasing market potential of Pacific white shrimp ( Litopenaeus vannamei) and limited availability of coastal areas for production, culture of L. vannamei at low salinity is a growing trend throughout the world. Dietary manipulation could improve the growth performance of L. vannamei at low salinity. This study reared L. vannamei with glucose, sucrose and corn starch as dietary carbohydrate sources, respectively, at a low salinity. The results indicated that the sucrose and glucose feeding groups showed better growth performance. An Illumina-based sequencing method was used to examine the intestinal bacterial composition and the results indicated that Proteobacteria were the most prevalent members, but abundance of Actinobacteria decreased while Firmicutes increased in the corn starch-fed group. Furthermore, bacteria related to complex carbohydrate degradation were in lower abundance, whereas the abundance of opportunistic pathogenic bacteria increased in corn starch-fed group than the other two groups, suggesting that the diet imposes selective pressure on the intestinal microbiota. Complex carbohydrates were not the ideal energy sources for L. vannamei at low salinity because the host has higher energy demand in the stressful conditions while the complex carbohydrate degradation efficiency of the gut microbiota in L. vannamei is limited. [ABSTRACT FROM AUTHOR]

Thermodynamic analysis and optimization of a multistage latent heat storage (LHS) unit with unsteady heat transfer fluid (HTF) inlet temperature were performed based on the entransy theory. The expressions of the optimum phase change material (PCM) melting temperatures ( T m,opt ) were derived. The results indicate that with the increase of stage number ( n ), T m1,opt increases and T mn,opt decreases, which extends the selection range of PCM. For fixed entransy dissipation condition, increasing n will not change the fluctuation of the HTF outlet temperature; however, a nearly uniform HTF outlet temperature can be obtained by increasing unit length ( L ). The unsteady HTF inlet temperature has great effects on the optimum phase change temperature. For a 3-stage LHS unit, the optimum phase change temperature of each stage increases by 14.9 K, 26.4 K and 38.0 K respectively with respect to the values obtained by steady method, which causes the heat storage capacity decreases by 6.1% and entransy dissipation decreases by 10.6%. The greater the temperature fluctuation is, the greater the effects will be. The present work can provide guidance for the design of the multistage LHS unit with unsteady HTF inlet temperature. [ABSTRACT FROM AUTHOR]