Swelling characteristics of soils derived from black shales heightened by cations in Northern Chongqing,China

Black shale is widely distributed in southern and western China.The swelling and breakdown characteristics of black shale are important physicomechanical properties in engineering activities.Aqueous solutions with different compositions exert various influences on the swelling characteristic of black shale because of the complexity of its composition.Soils derived from black shale are most commonly developed on black shales with bedded horizons that generally have cutting and weathering profiles.This paper reports an axial free swelling study for soils derived from black shales and developed in the Lower Cambrian black shales in Chengkou County,Chongqing Municipality,Southwest China.To discuss the swelling characteristics of black shale under the influence of cations,an axial free swelling test was conducted on black shale samples while considering the initial water content,weathering stage of black shale,and different cationic solutions with various concentrations.Results showed that the swelling deformation curve of black shale could be divided into three phases:acceleration,deceleration,and stability.The axial swelling ratio eventually decreased with increasing water content,and the axial free swelling rate changed with the free expansion model of the exponential relationship.Under a constant initial water content,the axial swelling rate increased with the intensity of black shale weathering in the same immersion solution.When different types of immersion solutions were used,the cationic price was high and the axial swelling rate increased with rising cation valence.The changes in the swelling ratio were significant at a valence of one or two.The results of this study provide further understanding of the engineering geological characteristics of black shale and the geological hazards caused by the swelling characteristics of black shale.

Tracking typhoon-generated swell in the western North Pacific Ocean using satellite altimetry

This paper proposes a scheme for detecting the swell decay of a moving typhoon. We considered a typhoon that was neither far from a point source nor had a belt-like homogenous source,as previously studied. We tracked the swell close to the source during a typhoon in the western North Pacific Ocean. We used wind speed and significant wave height data derived from the Geophysical Data Record of the Jason-1 altimeter and the best-track information of the typhoon from the China Meteorological Administration tropical cyclone database. We selected three specific cases to reveal the decay characteristics of the swell generated by a moving typhoon. Based on an altimeter-based typhoon swell identification scheme and the dispersion relationship for deep water,we relocated the swell source for each altimeter measurement. The subsequent statistical decay coefficient was comparable to previous studies,and effectively depicted the swell propagation conditions induced by the typhoon. We hope that our results provide a new understanding of the characteristics and wave energy budget of the North Pacific Ocean,and significantly contribute to wave modeling in this region.

A mechanically robust egg white hydrogel scaffold with excellent biocompatibility by three-step green processing

Egg white(EW) is one of the most common and high-quality nutritional proteins. A novel three-step green processing technology is constructed to process homogeneous EW into a mechanically robust EW hydrogel scaffold(EWHS) with excellent biocompatibility. The homogeneous EW is first treated with stream to form a hydrogel, then slowly dehydrated to form a fragile and almost transparent EW glass, and finally annealed into an EWHS. The EWHS is water-insoluble, wet soft and translucent and has a porous network structure, and its pore size distribution is between 0.1–1.0 μm. The tensile strength in wet state is as high as 5.0 MPa, the elongation at break is about 93%, and the swelling rate is about 85%. The order of the enzymatically residual rate of these EWHSs is pepsin > neutral protease > papain> trypsin > alkaline protease. Mouse L929 cells can adhere,proliferate, and grow well on the EWHSs. After EWHS was implanted in rats for three weeks, the levels of IL-6, TNF-α, and NF-κB inflammatory factors did not change significantly in comparison with the pseudo-operated and normal groups. This novel EW hydrogel biomaterial has potential applications in medical 3 D tissue engineering materials, such as tendons, soft tissues, and in vivo implants.

Irradiation Effects in Ni–17Mo–7Cr Alloy Bombarded with MeV Au Ions

Irradiation effects in Ni–17Mo–7Cr alloy have been systematically investigated by using 3 Me V Au ions at different fluences ranging from 8 × 10^13cm^-2to 2.3 × 10^15cm^-2,corresponding to doses of 1–30 dpa.The results indicated that sample microstrain increased gradually from 0.14 to 0.22% as dose increased from 0 to 30 dpa.Besides,the nanohardness of Ni–17Mo–7Cr alloy increased with irradiation dose until 10 dpa,and then,softening effect became dominant while further increasing dose to 30 dpa.After being irradiated at room temperature,the swelling rate of Ni–17Mo–7Cr alloy was found to be around 0.04% per dpa.These data are helpful in estimating the irradiation resistance of this newly developed Ni–17Mo–7Cr alloy in nuclear energy systems.