Effect of cohesive particle addition on bubbling characteristics of gas-solid fluidized bed: Meso-scale mechanism

Wei Liping,Li Haoqi,Wu Changsong,Lu Youjun,Luo Kun 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.6

Due to the small particle size and large specific surface area, the cohesive particles affect the flow characteristics in a gas-solid bubbling fluidized bed. They can easily produce agglomerated and smooth heterogeneous flow under the different cohesive particle addition amounts. The influence of the cohesive particle amount on the bubbling characteristics was experimentally investigated for two typical cases: bed surface agglomerate and well-dispersed with the bed. The images of bubble rise were recorded by digital camera and processed by binarization to track bubble motion and obtained the bubble motion characteristics. An energy minimization multiscale (EMMS) model based on binary particle bubble was expanded to the flow of cohesive particles to reveal the basic mechanism of influence of the cohesive particle. By comparing the results predicted by the model with the experimental data, it is found that the change rules of bubble size and bubble rising speed are similar, which proves the feasibility of the newly developed EMMS model. A study of the structure shows that the addition of cohesive particles increases the size of the bubbles and inhibits the collapse of the bubble due to the reduction of the gas-solid resistance coefficient.

Hexahedral Mesh Quality Improvement with Geometric Constraints

Wei Peng,Xinyu Mei,Kun Shao,ChenXin Song,Xinguang Wu 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.12

Hexahedral mesh is of great value in the analysis of mechanical structure, and the mesh quality has an important impact on the efficiency and accuracy of the analysis. This paper presents a quality improvement method for hexahedral meshes, which consists of node classification, geometric constraints based single hexahedron regularization and local hexahedral mesh stitching. The nodes are divided into different types and the corresponding geometric constraints are established in single hexahedron regularization to keep the geometric shapes of original mesh. In contrast to the global optimization strategies, we perform the hexahedral mesh stitching operation within a few local regions surrounding elements with undesired quality, which can effectively improve the quality of the mesh with less consuming time. Several mesh quality improvements for hexahedral meshes generated by a variety of methods are introduced to demonstrate the effectiveness of our method.

Design and Implementation of a Photovoltaic Grid-Connected Micro-Inverter with Power Factor Correction Technology

Yu-Kun Chen,Tsorng-Juu Liang,Wei-Chia Wu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

In this paper, a photovoltaic (PV) girdconnected micro-inverter controlled by power factor correction (PFC) controller is implemented. The PFC controller is adopted to control the inverter output current sinusoidally. Besides, the maximum power point tracking control circuit can get the maximum power form PV modules. The duality between the PFC circuit and the inverter circuit is presented first. Then, the PFC design rules is applied in the inverter circuit. However, the flyback inverter controlled by boundary conduction mode (BCM) PFC IC will cause a high third harmonic component from the analysis. Hence, the third harmonic injection method is estimated and analyzed to improve the output current total harmonic distortion. Finally, a 300W grid-connected flyback micro-inverter with BCM control based on L6561 PFC controller is implemented to verify the feasibility. Input voltage is 20V to 40V and the peak power is 300 W from PV simulator, and the output voltage is 220Vac/60Hz. The highest efficiency of the micro-inverter is 92.8%.

Synthesis, and antioxidant, thrombin-inhibitory, and anticancer activities of hydroxybenzamide derivatives

Jin-Rui Wei,Kun Liu,Faquan Lin,Chunping He,Xuan Luo,Jiajia Zou,Wei He,Wenqian Nong,Cui-Wu Lin 한국응용생명화학회 2016 Applied Biological Chemistry (Appl Biol Chem) Vol.59 No.2

Four hydroxybenzamide derivatives were synthesized from protocatechuic acid. The antioxidant activities of these derivatives were evaluated in vitro using DPPH radical scavenging and reducing power assays. In addition, these compounds were subjected to a chromogenic thrombin-inhibitory assay using Chromozym-TH as the substrate. The anticancer effects of these derivatives were also investigated using the MTT assay in three human cancer cell lines. Four derivatives exhibited excellent DPPH radical scavenging activity and redox potential. Their highly inhibitory effect against thrombin may allow them to be utilized as novel micromolecule thrombin inhibitors. Furthermore, four derivatives demonstrated different inhibitory activities in three human cancer cell lines but showed minimal harmful effects on normal HUVEC cells. Therefore, hydroxybenzamide derivatives indicate the superior antioxidant, thrombin-inhibitory, and anticancer activities along with the excellent biocompatibility, which have the potential application in therapeutic interventions and disease prevention of cancer, thrombotic diseases, and aging.

Association of RASSF1A Promoter Methylation with Lung Cancer Risk: a Meta-analysis

Huang, Ying-Ze,Wu, Wei,Wu, Kun,Xu, Xiao-Ning,Tang, Wen-Ru Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

RASSF1A, regarded as a candidate tumor suppressor, is frequently silenced and inactivated by methylation of its promoter region in many human tumors. However, the association between RASSF1A promoter methylation and lung cancer risk remains unclear. To provide a more reliable estimate we conducted a meta-analysis of cohort studies to evaluate the potential role of RASSF1A promoter methylation in lung carcinogenesis. Relevant studies were identified by searches of PubMed, Web of Science, ProQest and Medline databases using the following key words: 'lung cancer or lung neoplasm or lung carcinoma', 'RASSF1A methylation' or 'RASSF1A hypermethylation'. According to the selection standard, 15 articles were identified and analysised by STATA 12.0 software. Combined odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of the association between RASSF1A promoter methylation and lung cancer risk. A chi-square-based Q test and sensitivity analyses were performed to test between-study heterogeneity and the contributions of single studies to the final results, respectively. Funnel plots were carried out to evaluate publication bias. Overall, a significant relationship between RASSF1A promoter methylation and lung cancer risk (OR, 16.12; 95%CI, 11.40-22.81; p<0.001) with no between-study heterogeneity. In subgroup analyses, increased risk of RASSF1A methylation in cases than controls was found for the NSCLC group (OR, 13.66, 95%CI, 9.529-19.57) and in the SCLC group (OR, 314.85, 95%CI, 48.93-2026.2).

Association between hearing loss and physical performance in patients on maintenance hemodialysis

Fan Weifeng,Zhong Xiaojing,Wu Qing,Zhang Lihong,Yang Zhenhao,Gu Yong,Guo Qi,Chen Xiaoyu,Yu Chen,Zhang Kun,Ding Wei,Qi Hualin,Zhao Junli,Zhang Liming,Zhang Suhua,Niu Jianying 대한신장학회 2024 Kidney Research and Clinical Practice Vol.43 No.3

Background: The correlation between hearing loss (HL) and physical performance in patients receiving maintenance hemodialysis (MHD) remains poorly investigated. This study explored the association between HL and physical performance in patients on MHD. Methods: This multicenter cross-sectional study was conducted between July 2020 and April 2021 in seven hemodialysis centers in Shanghai and Suzhou, China. The hearing assessment was performed using pure-tone average (PTA). Physical performance was assessed using the Timed Up and Go Test (TUGT), handgrip strength, and gait speed. Results: Finally, 838 adult patients (male, 516 [61.6%]; 61.2 ± 2.6 years) were enrolled. Among them, 423 (50.5%) had mild to profound HL (male, 48.6% and female, 53.4%). Patients with HL had poorer physical performance than patients without HL (p < 0.001). TUGT was positively correlated with PTA (r = 0.265, p < 0.001), while handgrip strength and gait speed were negatively correlated with PTA (r = –0.356, p < 0.001 and r = –0.342, p < 0.001, respectively). Physical performance in patients aged <60 years showed significant dose-response relationships with HL. After adjusting for confounders, the odds ratios (95% confidence intervals) for HL across the TUGT quartiles (lowest to highest) were 1.00 (reference), 1.15 (0.73–1.81), 1.69 (1.07–2.70), and 2.87 (1.69–4.88) (p for trend = 0.005). Conclusion: Lower prevalence of HL was associated with a faster TUGT and a stronger handgrip strength in patients on MHD.

A 4th-Order Wideband Sigma Delta Modulator Using Linear System Theory Technique

Ming-yuan Ren,Yong-sheng Zhang,Wei-kun Wu,Zhen-xi Bao,Zi-wei Zhao,Chao Li,Hong-guo Zhang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.1

A 4th-Order Wideband Sigma Delta modulator structure is proposed in this paper, which uses linear system theory technique. There are many implementation techniques to improve the performance of Sigma Delta ADCs, such as noise coupling, differential sampling and dynamic elements matching. An extra loop delay is needed to be added in the system. This paper explains how to make the modulator stable with the addition of feed-forward and feed-back branches which are used to compensate the extra loop delay. Next, we restore the signal and noise transfer functions. A 4th-Order Wideband delta-sigma modulator have been designed and simulated to verify the method.

Staged Improvement in Awareness of Disease for Elderly Cancer Patients in Southern China

Li, Xing,Dong, Min,Wen, Jing-Yun,Wei, Li,Ma, Xiao-Kun,Xing, Yan-Fang,Deng, Yun,Chen, Zhan-Hong,Chen, Jie,Ruan, Dan-Yun,Lin, Ze-Xiao,Wang, Tian-Tian,Wu, Dong-Hao,Liu, Xu,Hu, Hai-Tao,Lin, Jia-Yu,Li, Zhu Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: In mainland China, awareness of disease of elderly cancer patients largely relies on the patients' families. We developed a staged procedure to improve their awareness of disease. Materials and Methods: Participants were 224 elderly cancer patients from 9 leading hospitals across Southern China. A questionnaire was given to the oncologists in charge of each patient to evaluate the interaction between family and patients, patient awareness of their disease and participation in medical decision-making. After first cycles of treatment, increased information of disease was given to patients with cooperation of the family. Then patient awareness of their disease and participation in medical decision-making was documented. Results: Among the 224 cancer elderly patients, 26 (11.6%) made decisions by themselves and 125 (55.8%) delegated their rights of decision-making to their family. Subordinate family members tended to play a passive role in decision-making significantly. Patients participating more in medical decision-making tended to know more about their disease. However, in contrast to the awareness of disease, patient awareness of violation of medical recommendations was reversely associated with their participation in medical decision-making. Improvement in awareness of diagnosis, stages and prognosis was achieved in about 20% elderly cancer patients. About 5% participated more actively in medical decision-making. Conclusions: Chinese elderly cancer patient awareness of disease and participation in medical decision-making is limited and relies on their family status. The staged procedure we developed to improve patient awareness of disease proved effective.

Hepatitis B Virus DNA Negativity Acts as a Favorable Prognostic Factor in Hepatocellular Carcinoma Patients

Li, Xing,Zhong, Xiang,Chen, Zhan-Hong,Xing, Yan-Fang,Wu, Dong-Hao,Chen, Jie,Ma, Xiao-Kun,Lin, Qu,Wen, Jing-Yun,Wei, Li,Wang, Tian-Tian,Ruan, Dan-Yun,Lin, Ze-Xiao,Wu, Xiang-Yuan,Dong, Min Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22

Background: This retrospective study was aimed to investigate the efficacy of prophylactic agents in hepatocellular carcinoma (HCC) patients receiving TACE and compare the difference between lamivudine and entecavir. Materials and Methods: A consecutive series of 203 HBV-related HCC patients receiving TACE were analyzed including 91 patients given prophylactic agents. Virologic events, defined as an increase in serum HBV DNA level to more than 1 log10 IU/ml higher than the nadir level, hepatitis flares due to HBV reactivation and progression free survival (PFS) were the main endpoints. Results: Some 48 (69.6%) reached virologic response. Prophylaxis significantly reduced virologic events (8.8% vs 58.0%, p=0.000) and hepatitis flares (1.1% vs 13.4%, p=0.001). Patients presenting undetectable HBV DNA levels displayed a significantly improved PFS as compared to those who never achieved undetectable HBV DNA. Prophylaxis and e-antigen positivity were the only significant variables associated with virologic events. In addition, prophylaxis was the only independent protective factor for hepatitis flares. Liver cirrhosis, more cycles of TACE, HBV DNA negativity, a lower Cancer of the Liver Italian Program score, non-metastasis and no hepatitis flares were protective factors for PFS. Prophylactic lamivudine demonstrated similar efficacy as entecavir. Conclusions: Prophylactic agents are efficacious for prevention of HBV reactivation in HCC patients receiving TACE. Achievement of undetectable HBV DNA levels displayed a significant capability in improving PFS. Moreover, persistent tumor residual lesions, positive HBV DNA and hepatitis B flares might be causes of tumor progression in these patients.

Efficacy of Prophylactic Entecavir for Hepatitis B Virus-Related Hepatocellular Carcinoma Receiving Transcatheter Arterial Chemoembolization

Li, Xing,Zhong, Xiang,Chen, Zhan-Hong,Wang, Tian-Tian,Ma, Xiao-Kun,Xing, Yan-Fang,Wu, Dong-Hao,Dong, Min,Chen, Jie,Ruan, Dan-Yun,Lin, Ze-Xiao,Wen, Jing-Yun,Wei, Li,Wu, Xiang-Yuan,Lin, Qu Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.18

Background and Aims: Hepatitis B virus (HBV) reactivation was reported to be induced by transcatheter arterial chemoembolization (TACE) in HBV-related hepatocellular carcinonma (HCC) patients with a high incidence. The effective strategy to reduce hepatitis flares due to HBV reactivation in this specific group of patients was limited to lamivudine. This retrospective study was aimed to investigate the efficacy of prophylactic entecavir in HCC patients receiving TACE. Methods: A consecutive series of 191 HBV-related HCC patients receiving TACE were analyzed including 44 patients received prophylactic entecavir. Virologic events, defined as an increase in serum HBV DNA level to more than 1 log10 copies/ml higher than nadir the level, and hepatitis flares due to HBV reactivation were the main endpoints. Results: Patients with or without prophylactic were similar in host factors and the majorities of characteristics regarding to tumor factors, HBV status, liver function and LMR. Notably, cycles of TACE were parallel between the groups. Ten (22.7%) patients receiving prophylactic entecavir reached virologic response. The patients receiving prophylactic entecavir presented significantly reduced virologic events (6.8% vs 54.4%, p=0.000) and hepatitis flares due to HBV reactivation (0.0% vs 11.6%, p=0.039) compared with patients without prophylaxis. Kaplan-Meier analysis illustrated that the patients in the entecavir group presented significantly improved virologic events free survival (p=0.000) and hepatitis flare free survival (p=0.017). Female and Eastern Cooperative Oncology Group (ECOG) performance status 2 was the only significant predictors for virological events in patients without prophylactic antiviral. Rescue antiviral therapy did not reduce the incidence of hepatitis flares due to HBV reactivation. Conclusion: Prophylactic entecavir presented promising efficacy in HBV-related cancer patients receiving TACE. Lower performance status and female gender might be the predictors for HBV reactivation in these patients.