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An Experimental on Filtration and Clogging of Geotextile Filters around Drain Pipes in Fine Tailings
Dong-dong Li,Xuan Cui,Jing-qi Huang,Ya-bing Han 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.5
Needle-punched nonwoven geotextiles have been used as filters for decades in mine drainage systems. But the physical clogging of geotextiles by fine particles has continued to receive increasing attention. In this study, the permeation characteristics of a drain pipe wrapped with geotextiles were investigated based on a new radial flow experiment apparatus, and particle size distribution (PSD), pore water pressure (PWP), and scanning electron microscopy (SEM) analyses were employed to identify the geotextile clogging mechanism. The geotextile cleaning methods after clogging were also discussed. The results showed that an exponential decay of hydraulic conductivity (K) with time under different flow conditions. Particles less than 30 μm migrated to the drainage pipe under the action of seepage forces, and a dense and thick cake layer was formed upstream of the geotextile filter. According to microscopic analysis, the clogging process of geotextiles was divided into three stages: pore blockage and cake formation, filter cake dynamic growth and cake layer filtration. Backwash cleaning is a good way to remove a filter cake layer on the surface of geotextiles, which can recover 60% of the hydraulic conductivity (K0).
Han, Xue,Dong, Yin,Xiu, Jian-Jun,Zhang, Jie,Huang, Zhao-Qin,Cai, Shi-Feng,Yuan, Xian-Shun,Liu, Qing-Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15
Background: This study was conducted to investigate whether apparent diffusion coefficient (ADC) measurements by dividing the liver into left and right hepatic lobes may be utilized to improve the accuracy of differential diagnosis of benign and malignant focal liver lesions. Materials and Methods: A total of 269 consecutive patients with 429 focal liver lesions were examined by 3-T magnetic resonance imaging that included diffusion-weighted imaging. For 58 patients with focal liver lesions of the same etiology in left and right hepatic lobes, ADCs of normal liver parenchyma and focal liver lesions were calculated and compared using the paired t-test. For all 269 patients, ADC cutoffs for focal liver lesions and diagnostic accuracy in the left hepatic lobe, right hepatic lobe and whole liver were evaluated by receiver operating characteristic curve analysis. Results: For the group of 58 patients, mean ADCs of normal liver parenchyma and focal liver lesions in the left hepatic lobe were significantly higher than those in the right hepatic lobe. For differentiating malignant lesions from benign lesions in all patients, the sensitivity and specificity were 92.6% and 92.0% in the left hepatic lobe, 94.4% and 94.4% in the right hepatic lobe, and 90.4% and 94.7% in the whole liver, respectively. The area under the curve of the right hepatic lobe, but not the left hepatic lobe, was higher than that of the whole liver. Conclusions: ADCs of normal liver parenchyma and focal liver lesions in the left hepatic lobe were significantly higher than those in the right hepatic lobe. Optimal ADC cutoff for focal liver lesions in the right hepatic lobe, but not in the left hepatic lobe, had higher diagnostic accuracy compared with that in the whole liver.
Dong Han,Huanyu Guang,Zheng Yang,XingCai Lu,Zhen Huang 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.8
The effects of fuel/air equivalence ratio and CO2 concentration in fuel/air charge on the ignition process of gasoline and diesel-like fuel (n-heptane) blends on a rapid compression machine are investigated in this study. Results showed that the effects of equivalence ratio on ignition delays of two ignition stages are varied. As equivalence ratio increases from 0.3 to 0.5, the first stage ignition delay slightly increases because the increased equivalence ratio improves the mixture heat capacity, reducing the in-cylinder temperature and weakening the low-temperature heat release process of the fuel. The second stage ignition delay is shortened with the increased equivalence ratio because increased fuel concentration facilitates mixture reactivity. CO2 addition to the cylinder charge can effectively reduce the peak cylinder pressure and the two stage pressure rise rates, as well as extend the durations of ignition delays of two ignition stages.
Han, Hyun Soo,Shin, Sun,Kim, Dong Hoe,Park, Ik Jae,Kim, Ju Seong,Huang, Po-Shun,Lee, Jung-Kun,Cho, In Sun,Zheng, Xiaolin Royal Society of Chemistry 2018 ENERGY AND ENVIRONMENTAL SCIENCE Vol.11 No.5
<P>Materials with low crystal symmetry often exhibit anisotropic properties, allowing the tuning of their physical and chemical properties <I>via</I> crystallographic orientation and exposed facet control. Herein, for the first time, we have demonstrated that pristine BiVO4 with a preferred [001] growth orientation and exposed (001) facets exhibits excellent intrinsic charge transport properties and surface reactivity. Using preferentially [001]-oriented BiVO4 (p-BVO) as a photoanode for photoelectrochemical water splitting, an impressive photocurrent density at 1.23 V <I>vs.</I> the reversible hydrogen electrode (RHE) is achieved, which is approximately 16 times higher than that exhibited by a photoanode based on randomly oriented BiVO4. Importantly, when the surface of p-BVO is further roughened and decorated with an oxygen evolution electrocatalyst, photocurrent densities of ∼3.5 and ∼6.1 mA cm<SUP>−2</SUP> are achieved at 0.6 and 1.23 VRHE, respectively; the latter value corresponds to ∼82% of the theoretically achievable photocurrent density for BiVO4 under 1 sun illumination. Our results demonstrate the effectiveness of crystal orientation and exposed facet control in optimizing materials for solar water-splitting applications.</P>
Huang, Kuo-Ying,Yoo, Hee Young,Jho, YongSeok,Han, Songi,Hwang, Dong Soo American Chemical Society 2016 ACS NANO Vol.10 No.5
<P>An exceptionally low interfacial tension of a dense fluid of concentrated polyelectrolyte complexes, phase separated from a biphasic fluid known as complex coacervates, represents a unique and highly sought-after materials property that inspires novel applications from superior coating to wet adhesion. Despite extensive studies and broad interest, the molecular and structural bases for the unique properties of complex coacervates are unclear. Here, a microphase-separated complex coacervate fluid generated by mixing a recombinant mussel foot protein-1 (mfp-1) as the polycation and hyaluronic acid (HA) as the polyanion at stoichiometric ratios was macroscopically phase-separated into a dense complex coacervate and a dilute supernatant phase to enable separate characterization of the two fluid phases. Surprisingly, despite up to 4 orders of magnitude differing density of the polyelectrolytes, the diffusivity of water in these two phases was found to be indistinguishable. The presence of unbound, bulk-like, water in the dense fluid can be reconciled with a water population that is only weakly perturbed by the polyelectrolyte interface and network. This hypothesis was experimentally validated by cryo-TEM of the macroscopically phase-separated dense complex coacervate phase that was found to be a bicontinuous and biphasic nanostructured network, in which one of the phases was confirmed by staining techniques to be water and the other polyelectrolyte complexes. We conclude that a weak cohesive energy between water water and water polyelectrolytes manifests itself in a bicontinuous network, and is responsible for the exceptionally low interfacial energy of this complex fluid phase with respect to virtually any surface within an aqueous medium.</P>
Lin Huang,Tingwen Guo,Yongjian Zhou,Dong Han,Yu Gu,Cheng Song,Feng Pan 한국자기학회 2022 Journal of Magnetics Vol.27 No.4
The casting process of Fe-Ni Invar alloy could drastically affect magnetic properties and thermal expansion. We have observed analogous trends of saturation magnetization and thermal expansion coefficient in two distinct types of casted samples, as we perform post-annealing at different temperatures. X-ray diffraction measurements show that all the alloys remain in the same face-centered cubic structure after different heat treatments without phase transformation. With the help of X-ray diffraction and differential thermal analysis, we have inferred that these changes in properties might be induced by magnetic lattice transitions and analyzed the possible reason for property differences in samples. This work delivers a perspective on the relationships between thermal expansion, magnetic properties, and heat treatments, which could help to improve the industrial assembly line design.