Aerodynamic noise numerical simulation and noise reduction study on automobile alternator

Chunrong Hua,Yadong Zhang,Dawei Dong,Bin Yan,Huajiang Ouyang 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.5

Aerodynamic noise is the predominant component of automobile alternator noise at high speed, which directly affects the noise characteristic and noise control of alternator. Based on Lighthill acoustic theory, the aerodynamic noise of an automobile alternator was simulated with three-dimensional, Large eddy simulation (LES) and Ffowcs Williams-Hawkings (FW-H) acoustic model, and the aerodynamic noise reduction research was conducted through optimizing the front fan blade spacing angle of alternator with vector composition method while considering high fan flow and optimal noise frequency components for reduced harmonic rotating noise of alternator. The results show that the sound pressure amplitude of the primary aerodynamic noise components simulated with LES are in good agreement with experimental ones, and the dominant harmonic frequency components of aerodynamic noise are in the 4th, 6th, 8th, 10th, 12th and 18th orders and the A-weighted sound pressure level of one-third octave mainly concentrates in 1120-7000 Hz. The average total noise level of alternator noise is decreased by 2.58 dB, and the mass flow of monitoring surface of fan blade is increased by 1.36 g/s with 5.80 dB decrease in the sound level of the 12th and 18th harmonic orders on average with optimized front fan blade spacing angles, which verifies the effectiveness of the noise reduction method proposed in this paper.

Anesthetic Management and Outcomes of Endovascular Treatment of Basilar Artery Occlusion: Results From the ATTENTION Registry

Tao Chunrong,Yuan Guangxiong,Xu Pengfei,Wang Hao,Zhou Peiyang,Yi Tingyu,Li Kai,Cui Tao,Gao Jun,Li Rui,Sun Jun,Zhang Chao,Wang Li,Liu Tianlong,Song Jianlong,Yin Yamei,Nguyen Thanh N.,Li Qing,Hu Wei 대한뇌졸중학회 2023 Journal of stroke Vol.25 No.3

Background and Purpose To examine the clinical and safety outcomes after endovascular treatment (EVT) for acute basilar artery occlusion (BAO) with different anesthetic modalities. Methods This was a retrospective analysis using data from the Endovascular Treatment for Acute Basilar Artery Occlusion (ATTENTION) registry. Patients were divided into two groups defined by anesthetic modality performed during EVT: general anesthesia (GA) or non-general anesthesia (non-GA). The association between anesthetic management and clinical outcomes was evaluated in a propensity score matched (PSM) cohort and an inverse probability of treatment weighting (IPTW) cohort to adjust for imbalances between the two groups. Results Our analytic sample included 1,672 patients from 48 centers. The anesthetic modality was GA in 769 (46.0%) and non-GA in 903 (54.0%) patients. In our primary analysis with the PSM-based cohort, non-GA was comparable to GA concerning the primary outcome (adjusted common odds ratio [acOR], 1.01; 95% confidence interval [CI], 0.82 to 1.25; <i>P</i>=0.91). Mortality at 90 days was 38.4% in the GA group and 35.8% in the non-GA group (adjusted risk ratio, 0.95; 95% CI, 0.83 to 1.08; <i>P</i>=0.44). In our secondary analysis with the IPTW-based cohort, the anesthetic modality was significantly associated with the distribution of modified Rankin Scale at 90 days (acOR: 1.45 [95% CI: 1.20 to 1.75]). Conclusion In this nationally-representative observational study, acute ischemic stroke patients due to BAO undergoing EVT without GA had similar clinical and safety outcomes compared with patients treated with GA. These findings provide the basis for large-scale randomized controlled trials to test whether anesthetic management provides meaningful clinical effects for patients undergoing EVT.

Phosphite Esters: Reagents for Exploring <i>S</i>-Nitrosothiol Chemistry

Liu, Chunrong,Park, Chung-Min,Wang, Difei,Xian, Ming American Chemical Society 2018 ORGANIC LETTERS Vol.20 No.24

<P>The reactions between <I>S</I>-nitrosothiols and phosphite esters, including P(OPh)<SUB>3</SUB>, P(OBn)<SUB>3</SUB>, and P(OEt)<SUB>3</SUB>, were studied. Two different conjugated adducts, thiophosphoramidates and phosphorothioates, were formed, depending on the structures of the <I>S</I>-nitrosothiol substrate (e.g., primary vs tertiary). These reactions proceeded under mild conditions, and the reaction mechanisms were studied using experiments and calculations.</P> [FIG OMISSION]</BR>

Biodegrading of Pyrene by a Newly Isolated Pseudomonas putida PL2

Lifeng Ping,Chunrong Zhang,Yahong Zhu,Min Wu,Xiuqing Hu,Zhen Li,Hua Zhao 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.5

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic compounds derived from natural sources and anthropogenic processes, which have been recommended as priority pollutants. Degradation of PAHs in the environment is becoming more necessary and urgent. In the current study, strain PL2, which is capable of growing aerobically on pyrene (PYR) as the sole carbon source, was isolated from hydrocarbons-contaminated soil and then identified as Pseudomonas putida by morphological and physiological characteristics as well as 16S rDNA sequence. The strain PL2 was able to degrade 50.0%of the pyrene at 28°C within 6 days in the presence of 50mg/L pyrene, while the strain PL2 degraded 50.0% of the pyrene within 2 days when a solution of 50 mg/L pyrene and 50 mg/L phenanthrene was used. In addition, phenanthrene was shown to increase the biodegradation efficiency of pyrene by the strain PL2. The order of degradation by the strain PL2 was pH 6.0 > pH 7.0 > pH 5.0 > pH 8.0. The degradation rate of PYR in the soil by the strain PL2reached 70.0% at the 10^th day. The dynamics of PYR degradation in soil by PL2 was fit to the first order model and the strain PL2 was shown to efficiently degrade PYR in soil. The current study showed that P. putida PL2 was a novel bacterium that could degrade pyrene and holds great promise for use in PAHs bioremediation in soil.

Establishment of forming limit diagram of thin-walled metal tube under pulsating hydraulic loading

Guolin Hu,Chunrong Pan 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

Establishment of forming limit diagram of thin-walled metal tube under pulsating hydraulic loading

Guolin Hu,Chunrong Pan 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

Investigation of the plastic hardening of metal thin-walled tube under pulsating hydraulic loading condition

Guolin Hu,Chunrong Pan 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.11

In the present study, the mechanical model of section element in tube bulging area was established through the stress conditions of hydraulic bulging. Based on the mechanical model, the equivalent stress and equivalent strain equations of the section element in the bulging area were derived, respectively. Combined with the experimental data, the equivalent stress and strain of the section element in the bulging area were fitted by polynomial, and the plastic hardening model of thin-walled tube under pulsating loading was obtained. In order to verify the model precision, the plastic hardening models obtained from pulsating hydroforming and non-pulsating hydroforming were taken as the material model by finite element simulation respectively. The experimental results were compared with the simulation results which showed that as a pulsating hydraulic loading material parameters, the model established in this paper had higher precision.

Distributed Carrier Aggregation in Small Cell Networks: A Game-theoretic Approach

( Yuanhui Zhang ),( Chunrong Kan ),( Kun Xu ),( Yuhua Xu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.12

In this paper, we investigate the problem of achieving global optimization for distributed carrier aggregation (CA) in small cell networks, using a game theoretic solution. To cope with the local interference and the distinct cost of intra-band and inter-band CA, we propose a non-cooperation game which is proved as an exact potential game. Furthermore, we propose a spatial adaptive play learning algorithm with heterogeneous learning parameters to converge towards NE of the game. In this algorithm, heterogeneous learning parameters are introduced to accelerate the convergence speed. It is shown that with the proposed game-theoretic approach, global optimization is achieved with local information exchange. Simulation results validate the effectivity of the proposed game-theoretic CA approach.

Coffin-Siris syndrome in two chinese patients with novel pathogenic variants of ARID1A and SMARCA4

Liu Mingjie,Wan Linlin,Wang Chunrong,Yuan Hongyu,Peng Yun,Wan Na,Tang Zhichao,Yuan Xinrong,Chen Daji,Long Zhe,Shi Yuting,Qiu Rong,Tang Beisha,Tang Beisha,Chen Zhao 한국유전학회 2022 Genes & Genomics Vol.44 No.9

Background: Coffin-Siris syndrome (CSS) is a rare congenital syndrome characterized by developmental delay, intellectual disability, microcephaly, coarse face and hypoplastic nail of the fifth digits. Heterozygous variants of different BAF complex-related genes were reported to cause CSS, including ARID1A and SMARCA4. So far, no CSS patients with ARID1A and SMARCA4 variants have been reported in China. Objective: The aim of the current study was to identify the causes of two Chinese patients with congenital growth deficiency and intellectual disability. Methods: Genomic DNA was extracted from the peripheral venous blood of patients and their family members. Genetic analysis included whole-exome and Sanger sequencing. Pathogenicity assessments of variants were performed according to the guideline of the American College of Medical Genetics and Genomics. The phenotypic characteristics of all CSS subtypes were summarized through literature review. Results: We identified two Chinese CSS patients carrying novel variants of ARID1A and SMARCA4 respectively. The cases presented most core symptoms of CSS except for the digits involvement. Additionally, we performed a review of the phenotypic characteristics in CSS, highlighting phenotypic varieties and related potential causes. Conclusions: We reported the first Chinese CSS2 and CSS4 patients with novel variants of ARID1A and SMARCA4. Our study expanded the genetic and phenotypic spectrum of CSS, providing a comprehensive overview of genotype-phenotype correlations of CSS.

Preparation and Investigation of Ulex Europaeus Agglutinin IConjugated Liposomes as Potential Oral Vaccine Carriers

KeXin Li,DaWei Chen,XiuLi Zhao,HaiYang Hu,ChunRong Yang,DaHai Pang 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.11

We prepared and optimized Ulex europaeus agglutinin I (UEAI)-modified Bovine serum albumin (BSA)-encapsulating liposomes (UEAI-LIP) as oral vaccine carriers and examined the feasibility of inducing systemic and mucosal immune responses by oral administration of UEAILIP. The prepared systems were characterized in vitro for their average size, zeta potential,encapsulation efficiency (EE%) and conjugation efficiency (CE%). In vitro release studies indicated that the presence of UEAI around the optimized liposomes was able to prevent a burst release of loaded BSA and provide sustained release of the encapsulated protein. In vivo immune-stimulating results in KM mice showed that BSA given intramuscularly generated systemic response only but both systemic and mucosal immune responses could be induced simultaneously in the groups in which BSA-loaded liposomes (LIP) and UEAI-LIP were administered intragastrically. Furthermore, the modification of UEAI on the surface of liposomes could further enhance the IgA and IgG levels obviously. In conclusion, this study demonstrated the high potential of lectin-modified liposomes containing the antigen as carriers for oral vaccine.