Numerical Cracking and Debonding Analysis of RC Beams Reinforced with FRP Sheet

Bonding a fiber reinforced polymer (FRP) sheet to the tension-side surface of reinforced concrete (RC) structures is often performed to upgrade the flexural capacity and stiffness. Except for upper concrete crushing, FRP sheet reinforcing RC structure may fail in sheet rupture, sheet peeloff failure due to opening of a critical diagonal crack, or concrete cover delamination failure from the sheet end. Accompanying the occurrence of these failure modes, reinforcing effects of the FRP sheet will be lost and load-carrying capacity of the RC structures will be decreased suddenly. This study is devoted to developing a numerical analysis method by using a three-dimensional elasto-plastic finite element method to simulate the load-carrying capacity of RC beams failed in the FRP sheet peeloff mode. Here, the discrete crack approach was employed to consider geometrical discontinuities such as opening of cracks, slipping of rebar, and debonding of the FRP sheet. Comparisons between analytical and experimental results confirm that the proposed numerical analysis method is appropriate for estimating the load-carrying capacity and failure behavior of RC beams flexurally reinforced with a FRP sheet.     

Dynamical Responses of Chaotic Memory Dynamics to Weak Input in a Recurrent Neural Network Model

Chaotic dynamics in a recurrent neural network model, in which limit cycle memory attractors are stored, is investigated by means of numerical methods. In particular, we focus on quick and sensitive response characteristics of chaotic memory dynamics to external input, which consists of part of an embedded memory attractor. We have calculated the correlation functions between the firing activities of neurons to understand the dynamical mechanisms of rapid responses. The results of the latter calculation show that quite strong correlations occur very quickly between almost all neurons within 1 ~ 2 updating steps after applying a partial input. They suggest that the existence of dynamical correlations or, in other words, transient correlations in chaos, play a very important role in quick and/or sensitive responses.     

生产阻燃剂聚酯和阻燃性母料的方法

正专利提供了生产阻燃性聚酯的方法,聚酯通过共聚含有高浓度的磷,共聚物具有高聚合度,而且二乙二醇组分的共聚合度低,不易变色。生产阻燃聚酯的方法包括边搅拌组成物边加热的步骤,组成物含有下述(A)-(E)的组分:(A)用通式(1)表示的磷化合物;(B)不饱和的二羧酸或其形成的酯化合物;(C)由以乙二醇为主所构成的饱和脂肪烃多元醇和/或酯-形成性的衍生物;(D)(B)成分外的多元羧酸或     

PEI-assisted preparation of Au nanoparticles via reductive crystallization process

Nano-sized gold particles were prepared in a solution containing polyethylenimine (PEI) utilizing a batch reactor. PEI acts as a reducing agent as well as a stabilizing agent of nanoparticles. The effects of initial concentration of PEI on the mean particle diameter, coefficient of variation (C.V.), growth rate, nucleation rate and the number of nuclei were studied. The particle diameter of gold decreased markedly with increasing initial concentration of PEI, from 3.3 μm to a minimum value of about 5 nm. The observed decrease of particle diameter was considered to be caused by the growth-inhibiting effect of PEI, which affects the conclusive number of nuclei.     

Redundant and selective roles for erythropoietin receptor tyrosines in erythropoiesis in vivo

Cytokine receptors have been shown in cell culture systems to use phosphotyrosine residues as docking sites for certain signal transduction intermediates. Studies using various cellular backgrounds have yielded conflicting information about the importance of such residues. The present studies were undertaken to determine whether or not tyrosine residues within the erythropoietin receptor (EPOR) are essential for biologic activity during hematopoiesis in vivo. A variant of the EPOR was constructed that contains both a substitution (R129C) causing constitutive receptor activation as well as replacement of all eight cytoplasmic tyrosines by phenylalanines (cEPORYF). A comparison between animals exposed to recombinant retroviruses expressing cEPOR and cEPORYF showed that efficient red blood cell (RBC) development in vivo is dependent on the pressence of tyrosine residues in the cytoplasmic domain of the EPOR. In addition, an inefficient EPOR tyrosine independent pathway supporting RBC development was detected. Tyrosine add-back mutants showed that multiple individual tyrosines have the capacity to restore full erythropoietic potential to the EPOR as determined in whole animals. The analysis of primary erythroid progenitors transduced with the various cEPOR tyrosine mutants and tyrosine add-backs showed that only tyrosine 343 (Y1) and tyrosine 479 (Y8) were capable of supporting immature burst-forming unit-erythroid progenitor development. Thus, this receptor is characterized by striking functional redundancy of tyrosines in a biologically relevant context. However, selective tyrosine residues may be uniquely important for early signals supporting erythroid development.     

Theoretical studies on VPI-5. 3. The MS-Q force field for aluminophosphate zeolites

Aluminophosphate zeolite is an artificial material which shows strange hydrophilicity. We have been investigating the reason by quantum mechanics, and found that the hydrophilicity of this zeolite depended on the local geometric deformation, and speculated that the site-specific hydrophilicity might be explained by differences in the stiffness of the local deformation determined by the location with the pore structure. In order to test these ideas, we construct a reliable force field based on the new MS-Q approach developed by Demiralp, Cagin, and Goddard. Our force field well reproduces the experimental structure of VPI-5.     

Low-dose N omega-nitro-L-arginine methyl ester treatment improves survival rate and decreases myocardial injury in a murine model of viral myocarditis induced by coxsackievirus B3

Recent reports demonstrated the expression of inducible-type NO synthase in the heart of viral myocarditis. Since NO has multiple biological actions, a substantial amount of NO produced in the diseased heart may act either as a cytotoxic or as a cytoprotective molecule in the process of myocarditis. In the present study, we examined the effect of inhibition of NO synthesis on the mortality and the extent of myocardial injury in a murine model of coxsackievirus B3-induced myocarditis. We fed the infected mice drinking water containing a relatively low concentration (0.37 mmol/L) of N omega-nitro-L-arginine methyl ester (L-NAME) for 14 days after virus inoculation. This dose of L-NAME did not change virus titers in the heart. However, L-NAME-fed mice showed a significant reduction in mortality compared with those fed normal drinking water (nontreated mice). On the contrary, mice given a higher concentration of L-NAME (3.7 mmol/L) exhibited increased mortality. In addition, mice fed a low concentration of L-NAME showed reductions in the severity of heart failure and in the area of myocardial necrosis. Although systemic blood pressure was reduced in nontreated mice, in mice fed a low concentration of L-NAME, it was maintained at a level similar to that in uninfected control mice, L-NAME-treated mice also exhibited a reduction in the degree of inflammatory cell infiltration associated with decreased production of tissue prostaglandin E2 levels in the heart compared with nontreated mice. Therefore, NO is likely to be involved in the pathogenic mechanisms of myocardial injury and resultant cardiac dysfunction in a murine model of coxsackievirus B3-induced viral myocarditis.     

Effects of growth temperature and [PH3]/[In(C2H5)3] on purity of epitaxial InP grown by metalorganic chemical vapour deposition

High-purity undoped InP epitaxial layers (ND ? NA = 5 × 1014 cm?3, ?77?105 cm2/Vs) are grown by low-pressure metalorganic chemical vapour deposition. The carrier concentrations decrease and the electron mobilities increase as the growth temperature decreases from 700°C to 575°C and the mole fraction ratios ([PH3]/[In(C2H5)3]) increase from 29 to 290.