Statistical Deformable Model-Based Reconstruction of a Patient-Specific Surface Model from Single Standard X-ray Radiograph

Author(s):  
Guoyan Zheng
2021 ◽  
Author(s):  
Muhammad U. Ghani ◽  
Xizeng Wu ◽  
Laurie L. Fajardo ◽  
Zhengxue Jing ◽  
Molly D. Wong ◽  
...  

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.


Author(s):  
Suiyi Zhu ◽  
Xia Yang ◽  
Gu-Ning Wang ◽  
Lei-Lei Zhang ◽  
He-Feng Zhu ◽  
...  

A kind of P-25 TiO2 films coated nickel foam was synthesized by a facile dip-coating/calcination route, and used to fabricate a continuous-flow three-phase photocatalytic reactor. The morphology, crystal phase structure, surface composition and specific surface area of P-25 films coated nickel foam were investigated by field emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption-desorption measurements, respectively. The results indicated that the coated/ calcined P-25 films had the porous surface structure fabricated by nano-sized titanium dioxide consisted of two crystal phases and incorporated with a NiO interlayer. The increase of P-25 contents enhanced the specific surface area; however, 20 percent of initial P-25 sol would result in visible large cracks because of too high P-25 content and consequently cause the peeling of films. The photocatalytic activities of nickel foam with different coating amounts of P-25 for the degradation of quinoline aqueous solutions were investigated with a continuous-flow three-phase photocatalytic reactor based on the P-25 films coated nickel foam. The results suggested that nickel foam coated with 10 percent of P-25 sol had an optimal photocatalytic activity for the degradation of quinoline aqueous solutions. The continuous-flow three-phase photocatalytic reactor fabricated with P-25 films coated nickel foam with an optimal P-25 coating amount shows high photocatalytic activity and stability for the degradation of quinoline aqueous solutions and industrial wastewater. The treated industrial wastewater meets the international discharge standard.


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