EFFECTS OF CATALYST STRUCTURAL PARAMETERS ON THE PERFORMANCE OF EXHAUST GAS AFTERTREATMENT SYSTEM OF DIESEL ENGINES

Tan Pi Qiang,Li Yun Peng,Wang De Yuan,Hu Zhi Yuan,Lou Di Ming 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.4

To meet increasingly stringent emission regulations, diesel engines must be equipped with DOC, DPF and SCR. Five performance parameters including system back pressure, HC conversion efficiency, conversion efficiency of NO to NO2, passive regeneration rate, and conversion efficiency of NO to N2 are very important for DOC+DPF+SCR system. Nine structural parameters including rDOC, rDPF, rSCR, σDOC, σDPF, σSCR, δDOC, δDPF, and δSCR di rectly a ffect t he f i ve performance parameters, this paper has carried out a detailed study on it. First, a simulation model of DOC+DPF+SCR system was established, and calibrated by experiment. Then, simulation was performed on the five performance parameters under different values of the nine structural parameters. Subsequently, a novel model using random forest algorithm was established to analyze the correlation between the performance parameters and the structural parameters. The results show that σDPF has the greatest influence on system backpressure, followed by rDPF. The rDOC has the greatest influence on HC conversion, followed by σDOC. The rDOC has the greatest influence on conversion of NO to NO2, followed by σDOC. The rDPF has the greatest influence on DPF passive regeneration rate, followed by rDOC. The rSCR has the greatest influence on conversion of NO to N2, followed by rDOC.

Metformin Attenuates Liver Fat Content: Finding from Schizophrenia Patients with Olanzapine-induced Weight Gain

Li Wang,Yu Chen,Yun-chuan Sui,Xing-qi Tan,Zhi Zhou,Ning Li,Le-ping Xu 대한정신약물학회 2020 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.18 No.1

Objective: This study was performed to evaluate the efficacy of metformin on liver fat content (LFC) in first episode schizophrenia patients with olanzapine-induced weight gain, and the relationship between the change of LFC and the other metabolic indices. Methods: In a double-blind study, the clinically stable inpatients with first-episode schizophrenia under olanzapine monotherapy who gained more than 7% of their baseline weight were randomly assigned to two groups; one with olanzapine plus metformin (1,000 mg/day) (metformin group) and the other with olanzapine plus placebo (placebo group) for 16 weeks. All patients continued to maintain the original olanzapine dosage. LFC was measured by magnetic resonance imaging at baseline and at the end of 16 weeks, respectively. At the same time, glucose and lipid metabolism, homeostasis model assessment of insulin resistance index (HOMA-IR) were measured respectively, analyzing the correlation between the change value of LFC and other indicators. Results: Over the 16-week study period, LFC value in metformin group decreased compared with baseline. LFC change across the 16-week treatment period was −2.91% for the metformin group and 0.59% for the placebo group, with a between-group difference of −3.5% (95% confidence interval, −6.08 to −0.93; p = 0.009). Compared to baseline, in the metformin group, triglyceride and HOMA-IR reduced significantly, while high density lipoprotein cholesterol increased significantly at weeks 16. There was positive correlation between LFC changes and triglycerides, HOMA-IR changes significantly. Conclusion: Metformin can significantly attenuate LFC in schizophrenia patients with olanzapine-induced weight gain. It may be related to the improvement of the part of the glucolipid metabolic indices

Health-related quality of life of patients with inflammatory bowel disease in Singapore

( Prisca Yue Min Ho ),( Wenjia Hu ),( Ying Yun Lee ),( Chuxi Gao ),( Yan Zhi Tan ),( Hua Heng Cheen ),( Hwee Lin Wee ),( Teong Guan Lim ),( Wan Chee Ong ) 대한장연구학회 2019 Intestinal Research Vol.17 No.1

Background/Aims: Inflammatory bowel disease (IBD) is associated with considerable impairment of patients’ health-related quality of life (HRQoL). Knowledge of factors that significantly affect IBD patients’ HRQoL can contribute to better patient care. However, the HRQoL of IBD patients in non-Western countries are limited. Hence, we assessed the HRQoL of Singaporean IBD patients and identified its determinants. Methods: A prospective, cross-sectional study was conducted at Singapore General Hospital outpatient IBD Centre. The HRQoL of IBD patients was assessed using the short IBD questionnaire (SIBDQ), Short Form-36 physical and mental component summary (SF-36 PCS/MCS) and EuroQol 5-dimensions 3-levels (EQ-5D-3L) and visual analogue scale (VAS). Independent samples t-test was used to compare HRQoL between Crohn’s disease (CD) and ulcerative colitis (UC). Determinants of HRQoL were identified through multiple linear regression. Results: A total of 195 IBD patients (103 UC, 92 CD) with a mean disease duration of 11.2 years were included. There was no significant difference in HRQoL between patients with UC and CD. Factors that significantly worsened HRQoL were presence of active disease (b=-6.293 [SIBDQ], -9.409 [PCS], -9.743 [MCS], -7.254 [VAS]), corticosteroids use (b=-7.392 [SIBDQ], -10.390 [PCS], -8.827 [MCS]), poor medication adherence (b=-4.049 [SIBDQ], -1.320 [MCS], -8.961 [VAS]), presence of extraintestinal manifestations (b=-13.381 [PCS]), comorbidities (b=-4.531 [PCS]), non-employment (b=-9.738 [MCS], -0.104 [EQ-5D-3L]) and public housing (b=-8.070 [PCS], -9.207 [VAS]). Conclusions: The HRQoL is impaired in this Asian cohort of IBD. The magnitude of HRQoL impairment was similar in UC and CD. Clinical characteristics were better determinants of patients’ HRQoL than socio-demographic factors. Recognizing the factors that impact patients’ HRQoL would improve the holistic management of IBD patients. (Intest Res 2019;17:107-118)

Effect of Sand Particle Size on Hydraulic-Mechanical Behavior of Bentonite-Sand Mixtures

Tian-Hao Lu,Wen-Jing Sun,Ke Liu,Yun-Zhi Tan 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.8

Bentonite-sand mixtures can be used as the base material of engineered barriers in deep high-level radioactive waste geological repositories. Swelling, compression, and permeability tests were conducted out on bentonite-sand mixtures with 30%, 50%, 70% and 85% sand content. Influence of sand content and particle size on the deformation and permeability characteristics of bentonite-sand mixtures were analyzed. The sand particle size affects the deformation characteristics by influencing the vertical stress required to form a sand skeleton, and the skeleton’s stability. When the sand content is less than the critical sand content, bentonite-sand mixtures cannot form a sand skeleton, and particle size has no effect on their characteristics. When the sand content is greater than the critical sand content and the vertical stress exceeds the initial deviation stress, a sand skeleton forms. In this case, smaller the sand particle size, lesser will be the vertical stress required to form a sand skeleton, and more the swelling of bentonite-sand mixtures. Further, more uniform particle size, more stable will be its structure and lesser the compressibility of bentonite-sand mixtures. The hydraulic conductivity is related to the flow area and the seepage path length, and particle size has no obvious effect on either with the same sand content. Therefore, the sand particle size has no obvious effect on mixtures’ permeability.

Predictions of Wake and Central Mixing Region of Double Horizontal Axis Tidal Turbine

Stephen Oppong,Wei-Haur Lam,Jianhua Guo,Leng Mui Tan,Zhi Chao Ong,Wah Yen Tey,Yun Fook Lee,Zaini Ujang,Ming Dai,Desmond Robinson,Gerard Hamill 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.7

Predicting the velocity distribution of double horizontal axis tidal turbines (DHATTs) is significant for the effective development of tidal streams. This current research gives an account on double turbine wake theory and flow structure of DHATT connected to single support by using the joint axial momentum theory and computational fluid dynamics (CFD) method. Characteristics of single turbine wake were previously studied with two theoretical equations predicting the initial upstream velocity closer to the turbine, and it’s lateral distributions along the downstream of the turbine. This current works agreed with the previous wake equations, which was used for predicting the velocity region along the downstream of the turbines. Flow field separating the two turbines is complicated in nature due to the indirect disturbance of turbines and no report was found on this central region. The Central region in the downstream flow is initially suppressed due to the blockage effects with a high velocity close to the free stream. Lateral expansion of two turbine wakes penetrated the central region with velocity reduction and followed by the flow recovery further downstream. This work provides more understandings of the wake and its central mixing region for double turbines with a proposed theoretical model.

In Vivo Protein Transduction: Delivery of PEP-1-SOD1 Fusion Protein into Myocardium Efficiently Protects against Ischemic Insult

You-en Zhang,Jia-ning Wang,Jun-ming Tang,Ling-yun Guo,Jian-ye Yang,Yong-zhang Huang,Yan Tan,Shou-zhi Fu,Xia Kong,Fei Zheng 한국분자세포생물학회 2009 Molecules and cells Vol.27 No.2

Myocardial ischemia-reperfusion injury is a medical problem occurring as damage to the myocardium following blood flow restoration after a critical period of coronary occlusion. Oxygen free radicals (OFR) are implicated in reperfusion injury after myocardial ischemia. The antioxidant enzyme, Cu, Zn-superoxide dismutase (Cu, Zn-SOD, also called SOD1) is one of the major means by which cells counteract the deleterious effects of OFR after ischemia. Recently, we reported that a PEP-1-SOD1 fusion protein was efficiently delivered into cultured cells and isolated rat hearts with ischemia-reperfusion injury. In the present study, we investigated the protective effects of the PEP-1-SOD1 fusion protein after ischemic insult. Immunofluorescecnce analysis revealed that the expressed and purified PEP-1-SOD1 fusion protein injected into rat tail veins was efficiently transduced into the myocardium with its native protein structure intact. When injected into Sprague-Dawley rat tail veins, the PEP-1-SOD1 fusion protein significantly attenuated myocardial ischemia-reperfusion damage; characterized by improving cardiac function of the left ventricle, decreasing infarct size, reducing the level of malondialdehyde (MDA), decreasing the release of creatine kinase (CK) and lactate dehydrogenase (LDH), and relieving cardiomyocyte apoptosis. These results suggest that the biologically active intact forms of PEP-1-SOD1 fusion protein will provide an efficient strategy for therapeutic delivery in various diseases related to SOD1 or to OFR.