Measurement and analysis of sound radiation from coherently vibrating shunt reactors

Yuxing Wang,Ming Jin,Yanzhao Wang,B. Zhou,Jie Pan 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

In parallel with the rapid development of ultra-high voltage (UHV) power transmission systems, noise contamination radiated from UHV shunt reactors is becoming an urgent concern. This investigation explored the distributed structural vibration of reactors and their near-field and far-field sound radiation characteristics based on a thorough on-site measurement and a combined numerical method. The proposed method could realize sound field reconstruction of on-site shunt reactors by directly measuring their surface vibration, thus avoiding complex modelling with fluid-structure interactions and multi-physics problems. Furthermore, the combined method was utilized to investigate the effect of acoustical environments upon reactors’ sound radiation. The results show that reflection boundaries composed of firewalls among reactor units could introduce a higher noise level in the parallel radiation region due to their influence on the sound source directivity. Finally, the sound power levels of the on-site reactors were derived from the constructed sound field, which could avoid on-site background noise concerns in the current executive standards.

Improved Preimage Attacks on RIPEMD-160 and HAS-160

( Yanzhao Shen ),( Gaoli Wang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.2

The hash function RIPEMD-160 is a worldwide ISO/IEC standard and the hash function HAS-160 is the Korean hash standard and is widely used in Korea. On the basis of differential meet-in-the-middle attack and biclique technique, a preimage attack on 34-step RIPEMD-160 with message padding and a pseudo-preimage attack on 71-step HAS-160 without message padding are proposed. The former is the first preimage attack from the first step, the latter increases the best pseudo-preimage attack from the first step by 5 steps. Furthermore, we locate the linear spaces in another message words and exchange the bicliques construction process and the mask vector search process. A preimage attack on 35-step RIPEMD-160 and a preimage attack on 71-step HAS-160 are presented. Both of the attacks are from the intermediate step and satisfy the message padding. They improve the best preimage attacks from the intermediate step on step-reduced RIPEMD-160 and HAS-160 by 4 and 3 steps respectively. As far as we know, they are the best preimage and pseudo-preimage attacks on step-reduced RIPEMD-160 and HAS-160 respectively in terms of number of steps.

Experimental Study on Flow Water Diffusion of Cement-Sodium Silicate Grouting in Rough Fracture Model

Zengguang Xu,Yanzhao Wang,Cheng Cao,Junrui Chai 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.5

Grouting is one of the common methods used to seal and reinforce fractures in underground construction. Flowing groundwater is often encountered in underground spaces, and grout sealing in such situations. Cement-sodium silicate (C-S) slurry is one of the commonly used quick-setting materials for sealing flowing water. Aperture width, initial water flow velocity, grout pressure and gel time are the key factors affecting dynamic flow grouting. Orthogonal tests based on a homemade experimental platform for simulating two-sided rough fractures in dynamic water grouting are conducted to investigate the effects of the four factors on slurry diffusion and sealing. The results show that there are three main modes of slurry diffusion: near cross diffusion mode, near U-shaped diffusion mode, and near T-shaped diffusion mode. Those affecting the slurry sealing efficiency from strong to weak are initial water flow velocity, aperture width, gel time and grouting pressure. The final distribution patterns of the slurry are divided into four types: successful sealing, partial sealing of boundary erosion, failure sealing of violent erosion, and ineffective sealing. According to these results, it has certain guiding significance for grouting sealing in practical engineering applications.

Rectal cancer-derived exosomes activate the nuclear factor kappa B pathway and lung fibroblasts by delivering integrin beta-1

Qingkun Gao,Ke An,Zhaoya Gao,Yanzhao Wang,Changmin Ding,Pengfei Niu,Fuming Lei The Korean Society of Pharmacology 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.4

Numerous studies have revealed the importance of tumor-derived exosomes in rectal cancer (RC). This study aims to explore the influence of tumor-derived exosomal integrin beta-1 (ITGB1) on lung fibroblasts in RC along with underlying mechanisms. Exosome morphology was observed using a transmission electron microscope. Protein levels of CD63, CD9, ITGB1, p-p65 and p65 were detected using Western blot. To determine ITGB1's mRNA expression, quantitative real-time polymerase chain reaction was used. Moreover, levels of interleukin (IL)-8, IL-1β, and IL-6 in cell culture supernatant were measured via commercial ELISA kits. ITGB1 expression was increased in exosomes from RC cells. The ratio of p-p65/p65 as well as levels of interleukins in lung fibroblasts was raised by exosomes derived from RC cells, while was reduced after down-regulation of exosomal ITGB1. The increased ratio of p-p65/p65 as well as levels of pro-inflammatory cytokines caused by exosomes from RC cells was reversed by the addition of nuclear factor kappa B (NF-κB) inhibitor. We concluded that the knockdown of RC cells-derived exosomal ITGB1 repressed activation of lung fibroblasts and the NF-κB pathway in vitro.

Size-Controlled Silver Nanoparticles Confined in Ordered Mesoporous Silica and Their Enhanced Catalytic Activities

Xiaofei Zhou,Jiawei Wan,Yefeng Liu,Di Liu,Hong Wang,Xiaoyong Lai,Yanzhao Zou,Guo Lin,Jian Chen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.9

A cooperative assembly route has been developed, by which silver nanoparticles with controlled sizes are incorporated into the channels of ordered cubic mesoporous silica (KIT-6) with different pore sizes (4.3–6.4 nm). The samples were characterized by XRD, TEM, FT-IR, UV-Vis and N2 physisorption. The pore wall of mesoporous silica can efficiently confine the growth of silver nanoparticles within the channels and their average sizes decreased with the pore size reduction of KIT-6. Catalytic activities of the resultant Ag/KIT-6-x (x stands for hydrothermal temperature) composite for reducing harmful organic dye Rhodamine B (Rh B) by sodium borohydride (NaBH4) were investigated. All the Ag/KIT-6 composite samples show great catalytic activities, among which Ag/KIT-6-80 with higher loading and smaller size of Ag nanoparticles exhibits higher catalytic activity than those of Ag/KIT-6-60 and Ag/KIT-6-100.

Effect of Calcium Chloride in Combination with Salicylic Acid on Post-harvest Freshness of Apples

Yan Zhao,Chen Wang 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.3

The effects of calcium chloride (CaCl2) and salicylic acid (SA) alone and in combination against postharvest anthracnose rot on apples caused by Colletotrichum gloeosporioides were investigated, and influences on several quality and disease resistance related parameters were evaluated. Dipping in a solution of 5% CaCl2+5 mM SA for 10 min was the most effective approach to inhibit C. gloeosporioides both in vitro and in vivo. A combined CaCl2 and SA treatment had the best efficacy for mitigation of the decline of total soluble solid content, titratable acidity, and firmness. Quality preservation plays an important role in apple post-harvest freshness. CaCl2 in combination with SA demonstrated the strongest effect for induction of disease resistance and maintenance of postharvest freshness of apples.

Partial-state Feedback Stabilization for a Class of Generalized Nonholonomic Systems with ISS Dynamic Uncertainties

Yan Zhao,Chunxiao Wang,Jiang-Bo Yu 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.1

In this paper, the problem of global stabilization control via partial-state feedback is addressed for a class of uncertain nonholonomic systems with the disturbed virtual control directions. The investigated nonholonomic system has the input-to-state stable (ISS) dynamic uncertainties. The small gain theorem and the changing supply function technique are employed to derive a global stabilization controller. Additionally, we develop a switching control strategy in order to get around the smooth stabilization burden associated with nonholonomic systems. The simulation results illustrate the efficacy of the presented algorithm.

Aromatic Diamino-bridged Bis(β-cyclodextrin) as Fluorescent Sensor for the Molecular Recognition of Bile Salts

Yan Zhao,Juan Gu,Shao Ming,Shao Ming Chi,Yong Cun Yang,Yu Fei Wang,Hong You Zhu,Jian Hong Liu,Rong Huang 대한화학회 2008 Bulletin of the Korean Chemical Society Vol.29 No.11

representative bile salts, i.e., cholate (CA), deoxycholate (DCA), glycocholate (GCA) and taurocholate (TCA), has been investigated at 25 °C in phosphate buffer (pH 7.20) by fluorescence, circular dichroism and 2D NMR spectroscopy. The result indicated that the bis(β-cyclodextrin) 2 acts as fluorescent sensor and displays remarkable fluorescence enhancement upon addition of optically inert bile salts. Form the induced circular dichroism (ICD) and ROESY spectra, it is deduced that the phenyl moiety in the linker of bis(β-cyclodextrin) 2 is partially self-included in the CD cavity, and is not expelled out of the CD cavity upon complexation with bile guests. Owing to the cooperative host-tether-guest binding mode in which the linker and guest are coincluded in the two CD cavities, bis(β-cyclodextrin) 2 significantly enhanced binding ability and molecular selectivity as compared with the native β-cyclodextrin 1 through the simultaneous contributions of hydrophobic, hydrogen bond, and electrostatic interactions. The complex stability constants are discussed comparatively and globally from the viewpoints of multiple recognition between host and guest.