Effect of Temperature on the Strength Characteristics of Unsaturated Silty Clay in Seasonal Frozen Region

Huie Chen,Haotian Guo,Xiaoqing Yuan,Yating Chen,Chao Sun 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.9

The strength characteristics of unsaturated silty clay after the cooling and single freeze-thawcycle were studied by using Global Digital Systems Ltd. (GDS) triaxial test system aftercontrolling initial matric suction. The results demonstrate that, the initial matrix suction andfreezing process can strengthen the shear strength of the soil, which makes the stress-straincurve of the soil show certain strain hardening characteristics at different temperatures. whenthe temperature is negative (including 0°C), the curve has a flat transition section whosestrength does not change with deformation, and the flat transition section becomes shorter asthe temperature and confining pressure decrease. The strength of the soil at negativetemperature and the speed at which it reaches its peak value are much greater than those ofthe soil after positive temperature and single freeze-thaw cycle, and the contribution ofconfining pressure to the strength decreases with the decrease of temperature. The effect oftemperature change (15oC to -15oC) on soil strength is mainly reflected in the total cohesion,and the effect of freeze-thaw on the effective internal friction angle is more significant. Thestrength and deformation characteristics of soil under the freezing process and freeze-thawcycle are determined by the initial matric suction, the form of connection between soilparticles, the migration of unfrozen water, and the degree of water-ice phase transformation.

Observations of Stress-dependent Microstructural Changes in Cement-stabilized Soil

( Huie Chen ),( Zongfang Chen ),( Jun Zhang ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Pore parameters of cement-stabilized soil samples were obtained by a mercury intrusion test to allow evaluation of the influence of microstructural characteristics on the macromechanical properties. Samples were subjected to a range of unconfined stresses (fractions of their unconfined compressive strength). Five characteristic pore size classes were determined (larger than 40 μm, 40-2.5 μm, 2.5-0.4 μm, 0.4-0.04 μm and less than 0.04 μm) and changes in the relative proportions of these classes were used to evaluate structural changes and the development of progressive failure of the cement-stabilized soils. The results show that in this cement-stabilized soil changes in applied stress have a significant effect on variations in micropore content. No obvious changes were observed in the proportions of larger pores during the initial loading stage. However, these proportions changed significantly as failure approached. The porosity of the samples showed a tendency to increase (dilatancy) after an initial decline.

Effect of Heavy Pruning on Oval Kumquat (Fortunella margarita Swingle) Flowering

Yu-Huie Lin,Kou-Tan Li,Su-Fen Ruan,Yun-Qiong Zhang,Zheng-Zhong Shi,Iou-Zen Chen 한국원예학회 2008 한국원예학회 기타간행물 Vol.- No.-

Easily prepared graphene-modified melamine sponge and its solar-aided adsorption performance on viscous oil

Fan Mingkan,Liu Huie,Guo Qilin,Zhang Yingbo,Chen Shuang,Zhang Wanqing,Shen Qi,Dou Xiangyan 한국탄소학회 2024 Carbon Letters Vol.34 No.3

Graphene-modified melamine sponges (RGO-MSs) were prepared, as adsorbents with photothermal conversion ability, utilizing solar energy to achieve heavy oil temperature rise, viscosity reduction, and efficient adsorption recovery of highly viscous oil. The RGO-MSs were prepared through a simple impregnation method. The photothermal performance and heavy oil adsorption performances of RGO-MSs with different densities and thicknesses were observed. It was found that as the density increases, the thermal conductivity of RGO-MS increases too, leading to the increase of the average oil absorption rate. The reduction of thickness is beneficial to improving of the adsorption rate. The prepared RGO-MS with a density of 21.5 mg/cm−3 and a height of 1 cm (RGO-MS-3-1) shows excellent mechanical properties and fatigue resistance. Cyclic adsorption–desorption of RGO-MS-3-1 was achieved through extrusion/ ethanol washing. After 10 cycles of reuse through extrusion, the adsorption capacity decreased from 52.90 to 50.02 g g−1, with a loss of 5.4%. The material was then washed with petroleum ether and ethanol in turn. Its adsorption capacity can restored to 98.8% of the initial value, showing a promising application prospect on heavy oil leakage treatment. The easily prepared RGO-MS exhibits excellent light absorption and photothermal oil adsorption properties, providing a good solution for the problem of heavy oil leakage at sea.

The Efficacy and Long-Term Outcome of Microcoil Embolotherapy for Acute Lower Gastrointestinal Bleeding

Hui-Chung Teng,Huei-Lung Liang,Yih-Huie Lin,Jer-Shyung Huang,Chiung-Yu Chen,Shang-Chieh Lee,Huay-Ben Pan 대한영상의학회 2013 Korean Journal of Radiology Vol.14 No.2

Objective: To evaluate the clinical efficacy as well as long-term clinical outcomes of superselective microcoil embolization for lower gastrointestinal bleeding (LGIB). Materials and Methods: Between 1997 and 2009, 26 patients with intended transcatheter embolotherapy for LGIB were retrospectively reviewed. Embolization was performed only when the catheter could be advanced to or distal to the mesenteric border of the bowel. The main purpose of our study was to assess technical success, recurrent bleeding rate and complications. We also evaluated the long-term clinical outcome, including late recurrent LGIB, bowel ischemia and the survival rate. Results: Twenty-two bleeding sources were in the territory of superior mesenteric artery and four in the inferior mesenteric artery. Technical success was achieved in 22 patients (84.6%). The target vessel of embolization was vasa recta in seventeen patients and marginal artery in the remaining five patients. Early rebleeding occurred in two patients (7.7%) and bowel ischemia in two patients, of whom the embolized points were both at the marginal artery. Delayed recurrent bleeding (> 30 days) occurred in two angiodysplasia patients. Five patients (19.2%) died within the first 30 days of intervention. Long-term follow-up depicted estimated survival rates of 58.2 and 43.1% after one, and five years, respectively. Conclusion: Transcatheter embolotherapy to treat LGIB is effective with low rebleeding and ischemic complications. Considering the advanced age and complex medical problems of these patients, the minimal invasive embolotherapy may be used as both a primary and potentially definitive treatment of LGIB.

Metallic Stent Placement in Hemodialysis Graft Patients after Insufficient Balloon Dilation

Huei-Lung Liang,Huay-Ben Pan,Yih-Huie Lin,Chiung-Yu Chen,Hsiao-Min Chung,Tung-Ho Wu,Kang-Ju Chou,Pin-Hong Lai,Chien-Fang Yang 대한영상의학회 2006 Korean Journal of Radiology Vol.7 No.2

Objective: We wanted to report our experience of metallic stent placement after insufficient balloon dilation in graft hemodialysis patients. Materials and Methods: Twenty-three patients (13 loop grafts in the forearm and 10 straight grafts in the upper arm) underwent metallic stent placement due to insufficient flow after urokinase thrombolysis and balloon dilation. The indications for metallic stent deployment included 1) recoil and/or kinked venous stenosis in 21 patients (venous anastomosis: 17 patients, peripheral outflow vein: four patients); and 2) major vascular rupture in two patients. Metallic stents 8 10mm in diameter and 40 80 mm in length were used. Of them, eight stents were deployed across the elbow crease. Access patency was determined by clinical follow-up and the overall rates were calculated by Kaplan-Meier survival analysis. Results: No procedure-related complications (stent fracture or central migration) were encountered except for a delayed Wallstent shortening/migration at the venous anastomosis, which resulted in early access failure. The overall primary and secondary patency rates ( standard error) of all the vascular accesses in our 23 patients at 3, 6, 12 and 24 months were 69% 9 and 88% 6, 41% 10 and 88% 6, 30% 10 and 77% 10, and 12% 8 and 61% 13, respectively. For the forearm and upper-arm grafts, the primary and secondary patency rates were 51% 16 and 86% 13 vs 45% 15 and 73% 13 at 6 months, and 25% 15 and 71% 17 vs 23% 17 and 73% 13 at 12 months (p = .346 and .224), respectively. Conclusion: Metallic stent placement is a safe and effective means for treating peripheral venous lesions in dialysis graft patients after insufficient balloon dilation. No statistically difference in the patency rates between the forearm and upper-arm patient groups was seen.

Preparation of N-TiO2/RGO nanocomposites through sol-gel method

Yudi Ma,Shukun Wang,Wanlan Zheng,Xin Xue,Huie Liu,Shuang Chen,Yiwen Zhu 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.9

Nitrogen-doped TiO2 and reduced graphene oxide (RGO) nanocomposites (NTG) were prepared by solgel method followed by annealing treatment process under N2 atmosphere. The as-prepared NTG nanocomposite were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet-visible diffuse reflectance spectroscopy (DRS). The results indicate that the incorporation of nitrogen onto both RGO and TiO2 was accomplished simultaneously in the facile process. Nitrogen doping makes the light excitation range red shift and can enhance the electron-hole separation effectively. The photocatalytic activity of the as-prepared samples was evaluated through the degradation of methyl orange (MO) under visible light irradiation. The introduction of nitrogen increased the photodegradation activity, which can be indicated by the fitted apparent first-order kinetics rate constant k, increasing about four times from 0- NTG-450 to 15-NTG-450. The annealing treatment further increased the photodegradation activity about 1.5 times of 15NTG-450 for 15NTG-800.