Potentiality of Using Vertical and Three-Dimensional Isolation Systems in Nuclear Structures

Zhiguang Zhou,Jenna Wong,Stephen Mahin 한국원자력학회 2016 Nuclear Engineering and Technology Vol.48 No.5

Although the horizontal component of an earthquake response can be significantly reduced through the use of conventional seismic isolators, the vertical component of excitation is still transmitted directly into the structure. Records from instrumented structures, and some recent tests and analyses have actually seen increases in vertical responses in base isolated structures under the combined effects of horizontal and vertical ground motions. This issue becomes a great concern to facilities such as a Nuclear Power Plants (NPP), with specialized equipment and machinery that is not onlyexpensive, but critical to safe operation. As such, there is considerable interest worldwide in vertical and three-dimensional (3D) isolation systems. This paper examines several vertical and 3D isolation systems that have been proposed and their potential application to modern nuclear facilities. In particular, a series of case study analyses of a modern NPP model are performed to examine the benefits and challenges associated with 3D isolation compared with horizontal isolation. It was found that compared with the general horizontal isolators, isolators that have vertical frequencies of no more than 3 Hz can effectively reduce the vertical in-structure responses for the studied NPP model. Among the studied cases, the case that has a vertical isolation frequency of 3 Hz is the one that can keep the horizontal period of the isolators as the first period while having the most flexible vertical isolator properties. When the vertical frequency of isolators reduces to 1 Hz, the rocking effect is obvious and rocking restraining devices are necessary.

Steel Fiber Reinforced Self-Compacting Concrete: A Comprehensive Review

Jawad Ahmad,Zhiguang Zhou,Ahmed Farouk Deifalla 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.6

Self-compacting concrete (SCC), which flows under its own weight without being compacted or vibrating, requires no outside mechanical force to move. But like normal concrete, SCC has a brittle character (weak in tension) that causes sudden collapse with no advance notification. The tensile capacity of SCC has increased owing to the addition of steel fiber (SF). Various research concentrates on increasing the tensile strength (TS) of SCC by incorporating SF. To collect information on past research, present research developments, and future research directions on SF-reinforced SCC, however, a detailed review of the study is necessary. The main aspects of this review are the general introduction of SCC, fresh properties namely slump flow, slump T50, L box, and V funnel, and strength properties such as compressive, tensile, flexure, and elastic modulus. Furthermore, failure modes of steel fiber-reinforced SCC are also reviewed. Results suggest that the SF decreased the filling and passing ability. Furthermore, improvement in strength properties was also observed. However, some studies reported that SF had no effect or even decreased compressive capacity. Additionally, SF improved the tensile capacity of SCC and avoid undesirable brittle failure. Finally, the review recommends the substitution of secondary cementitious materials in SF-reinforced SCC to improve its compressive capacity.

Self-Compacting Concrete with Partially Substitution of Waste Marble: A Review

Jawad Ahmad,Zhiguang Zhou,Ahmed Farouk Deifalla 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.4

Self-compacting concrete (SCC) is also seen as unsustainable since it uses a lot of natural resources. Recent researchers have focused on lowering construction costs and partially replacing cement with industrial waste. It is possible to effectively use various industrial wastes in concrete as cement or aggregates. Among these wastes, waste marble (WM) is a useful choice, and researchers have been interested in using WM in concrete for a couple of years. However, to pinpoint the advantages and recent advancements of research on WM as an ingredient of SCC, a comprehensive study is necessary. Therefore, the purpose of this study is to do a compressive evaluation of WM as an SCC ingredient. The review includes a general introduction to SCC and WM, the filling and passing capability of SCC, strength properties of SCC, durability, and microstructure analysis of SCC. According to the findings, WM improved the concrete strength and durability of SCC by up to 20% substitution due to micro-filling and pozzolanic reaction. Finally, the review also identifies research gaps for future investigations.

Fabrication of Stable Fluorine-Free Hydrophobic Cotton Fabrics with Prominent Antibacterial Property

Fengyi Qian,Meiping Chen,Zhiguang Li,Change Zhou,Rong Li,Xuehong Ren 한국섬유공학회 2023 Fibers and polymers Vol.24 No.11

Multifunctional cotton fabrics with antibacterial property and hydrophobicity were prepared using surface modification. Cotton fabrics were treated with the coating solution containing N-halamine compound poly[5,5-dimethyl-3-(3’-triethoxysilylpropyl) hydantoin] (PSPH) and TiO2 nanoparticles, followed by treated with polydimethylsiloxane (PDMS) to reduce the surface energy of cotton fabrics. The prepared cotton fabrics were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS), and X-ray diffractometry (XRD). After chlorination, the prepared cotton fabrics exhibited excellent hydrophobicity with contact angle of 143°. The antibacterial results demonstrated that the prepared cotton fabrics had excellent antibacterial activity and could completely inactivate 4.54 cfu/sample of S.aureus and 4.92 cfu/sample of E. coli O157:H7 within 30 min of contact. The treated cotton fabrics also possessed robust stability under washing, UV light irradiation, and abrasion. Moreover, the breaking strength and air permeability of cotton fabric could maintain to the required values for practical application after treatment.

The Antibacterial and Hydrophobic Cotton Fabrics Constructed by Multifunctional Polysiloxane and TiO2 Nanoparticles

Fengyi Qian,Meiping Chen,Change Zhou,Zhiguang Li,Rong Li,Xuehong Ren 한국섬유공학회 2023 Fibers and polymers Vol.24 No.2

Multifunctional polysiloxane was synthesized by introducing N-halamine compound precursor and stearyl methacrylateinto polyhydromethylsiloxane, and characterized by Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance(NMR). Cotton fabrics with antibacterial and hydrophobic properties were prepared via a simple one-pot method with thesynthesized polysiloxane and rutile TiO2nanoparticles. The prepared cotton fabrics was characterized by scanning electronmicroscopy (SEM), FT-IR, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results demonstratedthat prepared cotton fabrics could inactivate 3.9 × 106cfu/sample of S. aureus and 4.8 × 106cfu/sample of E. coli O157:H7within 30 min of contact time, and the water contact angle of the treated fabrics was 133°. The prepared cotton fabrics alsoexhibited excellent stability against 50 abrasion cycles. After 50 washing cycles, 72% of the chlorine content on preparedcotton fabrics could be recovered after rechlorination. And the antibacterial hydrophobic cotton fabrics loaded with TiO2possessed higher UV stability than cotton fabrics only treated with PTSAMS-Cl. Furthermore, the breaking strength ofantibacterial hydrophobic cotton fabrics was decreased while the wrinkle resistance was improved.

Preparation and Properties of Water-Resistant Antibacterial Curcumin/Silver Composite Nanofiber

Meiping Chen,Chao Ma,Change Zhou,Zhiguang Li,Rong Li 한국섬유공학회 2023 Fibers and polymers Vol.24 No.11

The water-resistant antibacterial PVA nanofibers containing curcumin (Cur) and silver nanoparticles (AgNPs) were prepared by electrospinning, and the AgNps were prepared by in situ reduction in the spinning solution. The prepared PVA nanofibers were measured by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectrophotometer (FT-IR). The breathable, hygroscopic, antibacterial, anti-inflammatory, and antioxidants functions of the prepared nanofibers were evaluated. The results indicated that the prepared nanofiber membrane has high swelling rate, moisture permeability, good mechanical properties, good biocompatibility, anti-inflammatory, antioxidant, and bacteriostatic activities with no cytotoxicity. Curcumin and AgNPs in the prepared nanofiber have effect on antibacterial activity and wound healing. The functionalized silver nanoparticles developed have effective activities against both Gram-negative bacteria and Gram-positive bacteria. In short, Cur/AgNPs composite nanofibers can be used as a potential medical dressing with antibacterial, anti-inflammatory, and antioxidant properties.

Tannin–Thioctic Acid Network Hydrogels with Antibacterial and Hydrophobic Properties

Xinyi Hu,Que Kong,Rong Li,Change Zhou,Zhiguang Li 한국섬유공학회 2023 Fibers and polymers Vol.24 No.10

Making a multifunctional hydrogel-based wound dressing is a long-term research goal. Therefore, it is of great significance to develop an ideal wound dressing with desirable biocompatibility, adhesive property, antibacterial property and simple production. Herein, molecular network crosslinking hydrogels were achieved through the nucleophilic addition of polyphenol-sulfur radical using tannic acid and thioctic acid as matrix. The multifunctional tannic–thioctic acid (TATA) hydrogels with excellent rheological properties were prepared by further modification of antibacterial and hydrophobic properties. The successful cross-linking of the molecules was confirmed by infrared spectroscopy, Raman spectroscopy and energy dispersive X-ray spectroscopy (EDX). Complex hydrogels had certain hydrophobic properties, which can slowly absorb wound tissue fluid and keep the wetness of the wound. In addition, the hydrogel had good rheological, antibacterial and antioxidant properties, and also improved blood clotting effect and biocompatibility. These results indicated that TATA hydrogel had the potential prospect to be used as a novel wound dressing for a wide range of medical applications.

Glutamic Acid Decarboxylase Autoantibody Detection by Electrochemiluminescence Assay Identifies Latent Autoimmune Diabetes in Adults with Poor Islet Function

Yuxiao Zhu,Li Qian,Qing Liu,Jing Zou,Ying Zhou,Tao Yang,Gan Huang,Zhiguang Zhou,Yu Liu 대한당뇨병학회 2020 Diabetes and Metabolism Journal Vol.44 No.2

Background: The detection of glutamic acid decarboxylase 65 (GAD65) autoantibodies is essential for the prediction and diagnosis of latent autoimmune diabetes in adults (LADA). The aim of the current study was to compare a newly developed electrochemiluminescence (ECL)-GAD65 antibody assay with the established radiobinding assay, and to explore whether the new assay could be used to define LADA more precisely. Methods: Serum samples were harvested from 141 patients with LADA, 95 with type 1 diabetes mellitus, and 99 with type 2 diabetes mellitus, and tested for GAD65 autoantibodies using both the radiobinding assay and ECL assay. A glutamic acid decarboxylase antibodies (GADA) competition assay was also performed to assess antibody affinity. Furthermore, the clinical features of these patients were compared. Results: Eighty-eight out of 141 serum samples (62.4%) from LADA patients were GAD65 antibody-positive by ECL assay. Compared with ECL-GAD65 antibody-negative patients, ECL-GAD65 antibody-positive patients were leaner (P<0.0001), had poorer β-cell function (P<0.05), and were more likely to have other diabetes-associated autoantibodies. The β-cell function of ECLGAD65 antibody-positive patients was similar to that of type 1 diabetes mellitus patients, whereas ECL-GAD65 antibody-negative patients were more similar to type 2 diabetes mellitus patients. Conclusion: Patients with ECL-GAD65 antibody-negative share a similar phenotype with type 2 diabetes mellitus patients, whereas patients with ECL-GAD65 antibody-positive resemble those with type 1 diabetes mellitus. Thus, the detection of GADA using ECL may help to identify the subtype of LADA.

Impact test of a centrifugal pump used in nuclear power plant under aircraft crash scenario

Huang, Tao,Chen, Mengmeng,Li, Zhongcheng,Dong, Zhanfa,Zhang, Tiejian,Zhou, Zhiguang Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.6

Resisting an accidental impact of large commercial aircrafts is an important aspect of advanced nuclear power plant (NPP) design. Especially after the 9·11 event, some regulations were enacted, which required the design of NPPs should consider the accidental impact of large commercial aircrafts. Normal working of equipment is important for stopping reactor under an impact when an NPP is in operation. However, there is a lack of reliable analysis and research on the impact test of nuclear prototype equipment. Therefore, in order to study the response of the equipment under high acceleration impact, a centrifugal pump is selected as the research object to perform the impact test. A horizontal half-sinusoidal pulse wave was applied to the working pump. The test results show that the horizontal response of the motor and flange is greater compared to other parts, as well as the vertical response of the coupling. The stress response of the pump body support and motor support is high, hence these parts should be considered in the design of the pump. Finally, combined with the damage and stress evaluation results of the pump under different amplitudes, the ultimate impact acceleration that the pump can withstand is given.

A highly efficient and selective fluorescent probe for Pd (II) based on benzotriazole-coumarin derivative and its catalytic application in Sonogashira reaction

Shaoheng Li,Ziji Bai,Feiyang Rong,Jiayin Huang,Lipan Zhou,Guodong Feng,Zhiguang Song 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

Palladium-catalyzed coupling reactions have become effective tools for forming new carbon–carbonbonds. In this work, a novel fluorescence active benzotriazole-coumarin derivative, (E)-N’-((1H-benzo[d][1,2,3]triazol-6-yl)methylene)-7-(diethylamino)-2-ox o-2H-chromene-3-carbohydrazide (BTANC),was synthesized as ligand in Pd(II) cation coordination. It is shown that BTANC has a strong fluorescentemission at 483 nm and Pd(II) can effectively quench the fluorescence of BTANC and BTANC shows excellentsensitivity and selectivity towards Pd (II) ions. Otherwise, the BTANC-Pd(II) complex was also testedin the Sonogashira coupling reaction of phenylacetylene and aryl halides. The desired product wasobtained with high yield (up to 99%) under the optimized reaction conditions. More to that, Low fluorescenceemission was observed during the Pd-catalyzed reaction process and the fluorescent emission ofBTANC was recovered at the end of the Pd-catalyzed reaction because the oxidative addition of the arylhalide towards Pd (0) was shut down at the end of the Pd-catalyzed reaction. This fluorescence propertiesof BTANC indicates the feasibility of using fluorescence signal as a potential tool to monitor the completionof the Sonogashira coupling reaction.