Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV

We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×109 protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to ∼10 GV and ∼20 GV, respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV.</p

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.</p

Chemical and microstructural investigations on slag hydration products

SIGLEAvailable from British Library Document Supply Centre- DSC:DX94974 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Self-cleaning and air purification performance of Portland cement paste with low dosages of nanodispersed TiO2 coatings

The strong agglomeration potential and poor re-dispersibility of nano TiO2 particles in powder form seriously affect the depollution and self-cleaning performances. The nano TiO2 particles in hydrosol form can be stably dispersed in aqueous solution, but the synthetic temperature influences the crystal pattern, stability, and hydrodynamic diameter of nano TiO2 particles. In this study, a stable and nano dispersed anatase TiO2 hydrosol is synthesized by hydrolysis of titanium isopropoxide, and the effects of synthetic temperature on physicochemical properties and stability of TiO2 hydrosol are discussed. The photocatalytic and self-cleaning performances of synthetic TiO2 hydrosol coating are characterized by the colour change rate of Rhodamine B and NOx conversion UV irradiation. Compared with a commercial nano TiO2 powder (Degussa P-25), the TiO2 hydrosol coating with very low dosages shows better photocatalytic and self-cleaning performances under the same experimental conditions

Nano dispersed TiO2 hydrosol modified Portland cement paste: the underlying role of hydration on self-cleaning mechanisms

The self-cleaning performance of photocatalytic cement paste is related to the dispersion of nano-TiO2 in the hardened matrix. This work aims to study the influences of Portland cement hydration on the self-cleaning behavior of acidic anatase TiO2 hydrosol modified hardened Portland cement paste (HPCP), and the working mechanisms. The presence of TiO2 hydrosol results in the retardation of hydration at early age and better self-cleaning performance of HPCP. The additional surface defects of TiO2 in HPCP are the main reason of self-cleaning performance enhancement. The morphology and the pore size distribution of hydration products also contribute to the enhancement of self-cleaning performance by the surface electron capture effect, which are supported by the analyses of Confocal Raman Microscopy and Scanning Electron Microscope. A new mechanism is suggested to explain the role of photocatalytic property and cement hydration on the enhancement of self-cleaning performance of HPCP with different concentration of TiO2 hydrosol

Crosslinked collagen/chitosan matrix for artificial livers

Matrices composed of collagen and chitosan may create an appropriate environment for the regeneration of livers. In this study, we have prepared, characterized and evaluated a new collagen/chitosan matrix (CCM). The CCM was made by using crosslinking agent 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) in N-hydroxysuccinimide (NHS) and a 2-morpholinoethane sulfonic acid (MES) buffer system. The chemical characteristics were evaluated by Fourier-transformed infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The mechanical strength was measured by tensile tests. The platelet deposition and hepatocyte culture experiments show that CCM has excellent blood and cell compatibility. The results suggest that the CCM is a promising candidate matrix for implantable bioartificial livers.\u

Optical Spectroscopy and Imaging for the Noninvasive Evaluation of Engineered Tissues

Optical spectroscopy and imaging approaches offer the potential to noninvasively assess different aspects of the cellular, extracellular matrix, and scaffold components of engineered tissues. In addition, the combination of multiple imaging modalities within a single instrument is highly feasible, allowing acquisition of complementary information related to the structure, organization, biochemistry, and physiology of the sample. The ability to characterize and monitor the dynamic interactions that take place as engineered tissues develop promises to enhance our understanding of the interdependence of processes that ultimately leads to functional tissue outcomes. It is expected that this information will impact significantly upon our abilities to optimize the design of biomaterial scaffolds, bioreactors, and cell systems. Here, we review the principles and performance characteristics of the main methodologies that have been exploited thus far, and we present examples of corresponding tissue engineering studies