1,721,552 research outputs found
Steady shear and viscoelastic behaviors of polyaniline suspension as an electrorheological fluid
No full textThe steagy shear and viscoelastic behaviors of polyaniline suspension in the mineral oil subject to an electric field were studied experimentally using a Couette cell type rheometer. The dynamic yield stress determined from the plateau stress in the range of low shear rate was evaluated as a function of the applied field and particle volume fraction. The resultant yield stress is linearly increased with volume fraction and E. The storage shear modulus and loss modulus have been measured using small amplitude forced oscillatory dynamic test as functions of strain amplitude, driving frequency, and the applied field strength. The linear viscoelastic region was found to be as below 0.01 of strain amplitude by performing the amplitude sweep test. The storage and loss moduli were strongly dependent upon strain amplitude while those were nearly independent of the driving frequency for the range of 10∼10rad/s
Experimental studies of isobutene (R600a) as the refrigerant in domestic refrigeration system
No full textAnalysis and design of dirty paper coding by transformation of noise
No full textThis work was supported by the center for Broadband
OFDM Mobile Access (BrOMA) at POSTECH through the
ITRC program of the Korean MIC, supervised by IITA.
(IITA-2006-C1090-0603-0037
A thermally efficient structure of InGaP/GaAs hetero-junction bipolar transistor for power amplifier applications
No full textRadiation-hardening of low noise readout integrated circuit for infrared focal plane arrays
No full textAdditive estrogenic activities of the binary mixtures of four estrogenic chemicals in recombinant yeast expressing human estrogen receptor.
No full textTo evaluate the estrogenic activities of several chemicals such as 17beta-estradiol (E2), rho-nonylphenol, bisphenol A, butylparaben, and combinations of these chemicals, we used recombinant yeasts containing the human estrogen receptor [Saccharomyces cerevisiae ER + LYS 8127]. We evaluated E2 was most active in the recombinant yeast assay, followed by rho-nonylphenol, bisphenol A, butylparaben. The combinations of some concentrations of 17-estradiol as a strong estrogen and bisphenol A or butylparaben as a weak estrogen showed additive estrogenic effects. Also, the combinations of some concentrations of nonlyphenol and butylparaben and combination of butylparaben and bisphenol A showed additive effects in the estrogenic activity. Therefore, the estrogenic activities of the combinations of two chemicals were additive, not synergistic.Y
Finite element analysis of polycrystalline deformation with the rate-dependent crystal plasticity
No full textConstitutive models for the crystal plasticity have the common objective which relates the behavior of microscopic single crystals in the crystallographic texture to the macroscopic continuum response. This paper presents the texture analysis of polycrystalline materials using the rate-dependent single crystal plasticity to develop a multi-scale description of the mechanism at the grain and aggregate levels. The texture analysis requires a numerical algorithm for integrating the constitutive equations. The implicit deformation gradient approach is employed to update the stresses and texture orientations as an integration algorithm. It considers elastic or plastic deformation gradient as the primary unknown variables and constructs the residual of the elastic and plastic velocity gradients as the governing equations. This algorithm is shown to be an efficient and robust algorithm in rather large time steps. The texture analysis of the asymmetric rolling process is also presented to show investigation of the effect of texture evolution based on the finite element analysis as a numerical example. The analysis result for texture evolution is investigated by comparing the pole figure before and after the asymmetric rolling process
- …
