Novel based on the galloping effect curved plate piezoelectric wind energy harvester

Yonghao. Liu,Jongwon. Seok 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.5

Flexible Cu2O/Cu film self-powered photodetector for high visible light selection and fast response

Liu Yonghao,Zhao Dawei,Sun Ximing,Cui Feng,Zhang Shan,Shang Xue,Xuan Zhen,Xiao Juqing,Wang Jiapeng,Ren Yandong 한국물리학회 2024 Current Applied Physics Vol.58 No.-

Spectral selection is one of the key performance parameters for visible light photodetectors (VLPD). However, as the absorbing layer of the VLPD, the semiconductor has strong ultraviolet light absorption, leading to poor visible light selectivity of the VLPD. This work fabricated a flexible photovoltaic VLPD based on Cu2O/Cu Schottky junction by annealing Cu foil. Under zero bias, the Cu2O/Cu VLPD showed the responsivity of 14 mA/W, the response time of 1 ms, and the detectivity of 8.8 × 1011 Jones to 620 nm light. Moreover, the detection band of the device is in the range of 500–640 nm, indicating excellent visible light selectivity. Optical and electrical characterization shows that the high visible selectivity of the device is mainly attributed to the fact that the penetration depth of visible light in Cu2O film matches the position of the Cu2O/Cu Schottky junction. This, in turn, induces the effective separation of the photogenerated carriers excited by the visible light. In addition, the bend detection performance of the device is demonstrated. This work provides a reference for improving the spectral selectivity of visible photodetectors.

A Novel Torsional Galloping Electromagnetic Wind Energy Harvester

Yonghao. Liu,Jongwon. Seok 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.11

Liver Shear-Wave Velocity and Serum Fibrosis Markers to Diagnose Hepatic Fibrosis in Patients with Chronic Viral Hepatitis B

Jianxue Liu,Yonghao Ji,Hong Ai,Bo Ning,Junzhi Zhao,Yaoren Zhang,Guoliang Dun 대한영상의학회 2016 Korean Journal of Radiology Vol.17 No.3

Objective: To compare several noninvasive indices of fibrosis in chronic viral hepatitis B, including liver shear-wave velocity (SWV), hyaluronic acid (HA), collagen type IV (CIV), procollagen type III (PCIII), and laminin (LN). Materials and Methods: Acoustic radiation force impulse (ARFI) was performed in 157 patients with chronic viral hepatitis B and in 30 healthy volunteers to measure hepatic SWV (m/s) in a prospective study. Serum markers were acquired on the morning of the same day of the ARFI evaluation. Receiver operating characteristic (ROC) analysis was performed to evaluate and compare the accuracies of SWV and serum markers using METAVIR scoring from liver biopsy as a reference standard. Results: The most accurate test for diagnosing fibrosis F ≥ 1 was SWV with the area under the ROC curve (AUC) of 0.913, followed by LN (0.744), HA (0.701), CIV (0.690), and PCIII (0.524). The best test for diagnosing F ≥ 2 was SWV (AUC of 0.851), followed by CIV (0.671), HA (0.668), LN (0.562), and PCIII (0.550). The best test for diagnosing F ≥ 3 was SWV (0.854), followed by CIV (0.693), HA (0.675), PCIII (0.591), and LN (0.548). The best test for diagnosing F = 4 was SWV (0.965), followed by CIV (0.804), PCIII (0.752), HA (0.744), and LN (0.662). SWV combined with HA and CIV did not improve diagnostic accuracy (AUC = 0.931 for F ≥ 1, 0.863 for F ≥ 2, 0.855 for F ≥ 3, 0.960 for F = 4). Conclusion: The performance of SWV in diagnosing liver fibrosis is superior to that of serum markers. However, the combination of SWV, HA, and CIV does not increase the accuracy of diagnosing liver fibrosis and cirrhosis.

Cellulose nanocrystals-assisted hydrothermal synthesis of mesoporous α-Fe2O3 for photocatalysis

Hunan Liang,Kai Liu,Yonghao Ni 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.9

A hydrothermal process was adopted to synthesize mesoporous α-Fe2O3 materials using cellulose nanocrystals as template, andits photocatalytic performance on degradation of dye was investigated. The characteristic results through XRD and N2adsorption showed that the mesoporous α-Fe2O3 was successfully prepared, which possessed an average pore size of 39.5 nmand surface area of 46.5 m2 g−1. The photocatalytic capacity of the synthesized mesoporous α-Fe2O3 was determined byfollowing the degradation of methylene blue (MB) under visible-light irradiation conditions, and the results showed that thesample prepared with CNC exhibited better photocatalytic activity under the condition studied than that prepared withoutCNC. These results demonstrated that thus prepared mesoporous α-Fe2O3 would have a great potential to be used as a catalystin degrading organic dyes during a typical industrial wastewater treatment.

A novel and effective approach to enhance the interfacial interactions of meta-aramid fibers

Hui Zhang,Xiaoyun Du,Jiawei Liu,YunHong Bai,Jingyi Nie,Jiaojun Tan,Zhibin He,Meiyun Zhang,Jinbao Li,Yonghao Ni 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Meta-aramid paper exhibits some unique properties, including high temperature resistance, electricalinsulation. However, due to the inherent chemical inertness of aramid fibers, the interfacial bondingbetween fibers is weak, which negatively affect the properties of aramid paper. Herein, we report a simple,effective and scalable process for substantially improving the interfacial bonding between aramidfibers, thus, mechanical and insulating properties of the meta-aramid composite paper, and it wasachieved by surface coating of aramid paper with meta-aramid stock solution that contains N, N dimethylacetamide(DMAc)-CaCl2 and high molecular weight poly (m-phenylene isophthalamide) polymers. Results show that the tensile strength, modulus, internal bond strength and tearing index of the resultantall-PMIA paper increased by 83 %, 58 %, 173 % and 89 %, respectively, in comparison with those of the control. The breakdown strength of the improved aramid paper is 190 % higher than that of the control paper,attaining 26.46 KV/mm. This work provides a simple, economical, efficient, and scalable method toimprove the overall performance of meta-aramid paper, which has great potential to be implementedat the industrial scale.

Comparison of Clinical and Radiographic Outcomes Between Transforaminal Endoscopic Lumbar Discectomy and Microdiscectomy: A Follow-up Exceeding 5 Years

Xinyu Yang,Shijun Zhang,Junxiao Su,Sai Guo,Yakubu Ibrahim,Kai Zhang,Yonghao Tian,Lianlei Wang,Suomao Yuan,Xinyu Liu 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). Methods: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients’ clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. Results: During a mean follow-up of 5.5 years (range, 5–7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio. Conclusion: Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis. Objective: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). Methods: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients’ clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. Results: During a mean follow-up of 5.5 years (range, 5–7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio.