FRACTURE ASSESSMENT FOR SECONDARY LOADS

The fracture assessment of structures subjected to secondary loading systems was studied by FEM-analysis of a few illustrative two-dimensional examples. The first example is an edge-cracked plate with a thermal gradient. The FEM-calculations revealed that a purely elastic analysis yielded J-values that are in most cases considerably more conservative than the ones calculated from an elastic-plastic analysis. The results were further compared with different engineering type non-linear estimates. As a second example a crack emanating from a semi-circular notch in a rectangular plate was chosen. The plate was subjected to uniaxial tension along its boundaries. It turned out that for the cases considered the J-values were fairly close to those elastically predicted.     

A multiparameter wearable physiologic monitoring system for space and terrestrial applications.

A novel, unobtrusive and wearable, multiparameter ambulatory physiologic monitoring system for space and terrestrial applications, termed LifeGuard, is presented. The core element is a wearable monitor, the crew physiologic observation device (CPOD), that provides the capability to continuously record two standard electrocardiogram leads, respiration rate via impedance plethysmography, heart rate, hemoglobin oxygen saturation, ambient or body temperature, three axes of acceleration, and blood pressure. These parameters can be digitally recorded with high fidelity over a 9-h period with precise time stamps and user-defined event markers. Data can be continuously streamed to a base station using a built-in Bluetooth RF link or stored in 32 MB of on-board flash memory and downloaded to a personal computer using a serial port. The device is powered by two AAA batteries. The design, laboratory, and field testing of the wearable monitors are described.     

Initial scalar lithospheric magnetic anomaly map of China and surrounding regions derived from CSES satellite data

Science China Technological Sciences - The China Seismo-Electromagnetic Satellite (CSES), China’s first satellite to measure geophysical fields with scientific goals in both space and solid...     

Realization of a temperature sensor using both two- and three-dimensional photonic structures through a machine learning technique

A temperature sensor based on photonic crystal structures with two- and three-dimensional geometries is proposed, and its measurement performance is estimated using a machine learning technique. The temperature characteristics of the photonic crystal structures are studied by mathematical modeling. The physics of the structure is investigated based on the effective electrical permittivity of the substrate (silicon) and column (air) materials for a signal at 1200 nm, whereas the mathematical principle of its operation is studied using the plane-wave expansion method. Moreover, the intrinsic characteristics are investigated based on the absorption and reflection losses as frequently considered for such photonic structures. The output signal (transmitted energy) passing through the structures determines the magnitude of the corresponding temperature variation. Furthermore, the numerical interpretation indicates that the output signal varies nonlinearly with temperature for both the two- and three-dimensional photonic structures. The relation between the transmitted energy and the temperature is found through polynomial-regression-based machine learning techniques. Moreover, rigorous mathematical computations indicate that a second-order polynomial regression could be an appropriate candidate to establish this relation. Polynomial regression is implemented using the Numpy and Scikit-learn library on the Google Colab platform.

     

X-ray Fluorescence Uptake Measurement of Functionalized Gold Nanoparticles in Tumor Cell Microsamples

Quantitative cellular in vitro nanoparticle uptake measurements are possible with a large number of different techniques, however, all have their respective restrictions. Here, we demonstrate the application of synchrotron-based X-ray fluorescence imaging (XFI) on prostate tumor cells, which have internalized differently functionalized gold nanoparticles. Total nanoparticle uptake on the order of a few hundred picograms could be conveniently observed with microsamples consisting of only a few hundreds of cells. A comparison with mass spectroscopy quantification is provided, experimental results are both supported and sensitivity limits of this XFI approach extrapolated by Monte-Carlo simulations, yielding a minimum detectable nanoparticle mass of just 5 pg. This study demonstrates the high sensitivity level of XFI, allowing non-destructive uptake measurements with very small microsamples within just seconds of irradiation time.     

Phase Stability of Fine-Grained (Mg,Y)-PSZ

A fine-grained zirconia, which has been costabilized with yttria and magnesia, has been prepared. Its stability during subeutectoid annealing at 1100^deg;C, and its hydrothermal stability during hydrothermal treatment at 180^deg;C, have been determined and they are compared to those of Y-TZP and Mg-PSZ materials .