Time dependence of mesoscopic strain distribution for triaxial woven carbon-fiber-reinforced polymer under creep loading measured by digital image correlation

This paper presents the time dependence of the mesoscopic strain of a triaxial woven carbon-fiber-reinforced polymer under creep loading measured using digital image correlation (DIC). Two types of DIC techniques were employed for the measurement: conventional subset DIC and mesh DIC. Static tensile and creep tests were carried out, and the time dependence of the mesoscopic strain distribution was investigated by applying these techniques. The ultimate failure of this material is dominated by inter-bundle decohesion caused by relative rigid rotation and relating shear stress. Therefore, these were focused on in the present study. During the creep tests, the fiber directional strain, shear strain, and rotation were monitored using the DIC, and the mechanism for the increase in the specimen’s macro-strain over time was investigated based on the results obtained by the DIC measurement.     

Amorphous nanosilicas induce consumptive coagulopathy after systemic exposure

We previously reported that well-dispersed amorphous nanosilicas with particle size 70 nm (nSP70) penetrate skin and produce systemic exposure after topical application. These findings underscore the need to examine biological effects after systemic exposure to nanosilicas. The present study was designed to examine the biological effects. BALB/c mice were intravenously injected with amorphous nanosilicas of sizes 70, 100, 300, 1000 nm and then assessed for survival, blood biochemistry, and coagulation. As a result, injection of nSP70 caused fatal toxicity, liver damage, and platelet depletion, suggesting that nSP70 caused consumptive coagulopathy. Additionally, nSP70 exerts procoagulant activity in vitro associated with an increase in specific surface area, which increases as diameter reduces. In contrast, nSP70-mediated procoagulant activity was absent in factor XII-deficient plasma. Collectively, we revealed that interaction between nSP70 and intrinsic coagulation factors such as factor XII, were deeply related to nSP70-induced harmful effects. In other words, it is suggested that if interaction between nSP70 and coagulation factors can be suppressed, nSP70-induced harmful effects may be avoided. These results would provide useful information for ensuring the safety of nanomaterials (NMs) and open new frontiers in biological fields by the use of NMs.     

基于价值评价方法对天津碱厂进行工业遗产的分级保护

工业遗产的价值评价、保护及再利用的方式成为目前的研究热点。基于价值评价法,对天津碱厂工业遗产的价值评价与工业遗产的实体相结合,探讨工业遗产的价值评价分级与分级保护方式,为工业遗产的保护和改造再利用方式提供理论依据。     

Falling of particle beds in a vertical pipe with closed top

Light which is scattered by small particles (2 – 120 μm in diameter) can be used to determine the cross-sectional area of those particles. A new measurement technique has been developed in which three single measurements of the scattered light are used to determine the volume mean diameter, area mean diameter, and variance of the particle distribution regardless of the nature of the distribution. This is accomplished by means of a uniquely shaped spatial filter which, when placed in the Fraunhofer diffraction plane, transmits the proper amount of light as a function of scattering angle to give the desired responses.Signal handling is accomplished by means of a microcomputer. The analog signal from the photodetector is fed to an analog-to-digital converter. All computations are carried out digitally and the result displayed on an LED readout. A digital printer is used for convenience in taking data.This measurement technique can be applied both in the laboratory and in process measurement and control. Both slurry and dry samples can be handled. Experimental results of the instrument performance are presented along with discussion of other potential applications for the measurement technique.     

Optimal discrete-time control system with cost for observation

The problem of how to select the total number and the spacings of the observations optimally when a constant cost is incurred for each observation taken is discussed. Approximate expressions for the criterion function with a fixed number of observations are obtained and are used to determine the optimal total number of observations. For a class of multidimensional systems with a dominant eigenvalue, the problem is shown to reduce to that for scalar systems. Detailed discussion is then carded out for scalar systems including some sensitivity study.