An alternative atmospheric-pressure cold plasma method for synthesizing Pd/P25 catalysts with the assistance of ethanol

Di, Lanbo,Li, Zhuang,Lee, Byungjin,Park, Dong-Wha Elsevier 2017 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.42 No.16

<P><B>Abstract</B></P> <P>Atmospheric-pressure (AP) cold plasma has experienced a growing interest recently due to its simplicity and high efficiency for preparing supported metal catalysts by using the active hydrogen species generated from explosive H<SUB>2</SUB> gas. In this communication, we report an alternative AP cold plasma method for synthesizing supported Pd catalysts using Ar gas and ethanol instead of explosive H<SUB>2</SUB> gas and toxic reducing agents. The TOF value of the prepared Pd/P25 catalyst at 120 °C is 3.1 times of that prepared by cold plasma using H<SUB>2</SUB> gas due to the protection of the formed carbon species. AP cold plasma using ethanol as the origin of active hydrogen species is safer and more efficient than that using H<SUB>2</SUB> gas, and may also have great potentials to synthesize other supported metal catalysts.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An alternative AP cold plasma method was employed to synthesize Pd catalyst. </LI> <LI> Ethanol was adopted to generate active hydrogen species instead of explosive H<SUB>2</SUB>. </LI> <LI> Protection of the residual carbon species is responsible for the small size of Pd. </LI> <LI> TOF of Pd/P25 prepared using ethanol is 3.1 times of that prepared using H<SUB>2</SUB> gas. </LI> <LI> It is a safer, facile and environmentally benign AP cold plasma method. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Evaluation of effective thermal conductivity of unsaturated granular materials using random network model

Lee, Chulho,Zhuang, Li,Lee, Dongseop,Lee, Seokjae,Lee, In-Mo,Choi, Hangseok Elsevier 2017 Geothermics Vol.67 No.-

<P><B>Abstract</B></P> <P>The effective thermal conductivity of granular materials is widely used in numerous geothermal engineering applications, such as the ground source heat pump (GSHP) system. However, for unsaturated granular materials, it is difficult to predict the thermal conductivity because of the interaction between solid and fluid in media. In this study, the effective thermal conductivity of unsaturated granular materials was measured, reviewed and analysed using a macroscopic pore structure network model with a randomly packed particles. The network model was verified by measured data (soil water characteristics curve, thermal conductivity and etc.) of three different glass beads and also Jumunjin sand (standard sand of South Korea). Upon the series of laboratory experiments, some modification to the existing network model were introduced, such as the use of soil water characteristic curve (SWCC) applied to modelling the thermal conductivity of granular materials. In addition, an empirical correlation between the fraction of the mean radius (χ) and the thermal conductivity at a given saturated condition was developed through comparison with the test results. In the range of lower degree of saturation (5%–20%), the modified network model shows relatively higher thermal conductivity than the laboratory measurements. However, for the higher degree of saturation (>40%), it shows a similar tendency to the laboratory measurements.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effective thermal conductivity of granular material at the unsaturated condition is evaluated using the network model. </LI> <LI> A modified fraction of the mean radius is introduced in the modified network model. </LI> <LI> The modified network model estimates the effective thermal conductivity of porous media in all range of the degree of saturation. </LI> </UL> </P>

Cleavage Dependent Indirect Tensile Strength of Pocheon Granite Based on Experiments and DEM Simulation

Li Zhuang(장리),Melvin B. Diaz(멜빈 디아즈),Sung Gyu Jung(정성규),Kwang Yeom Kim(김광염) 한국암반공학회 2016 터널과지하공간 Vol.26 No.4

본 연구는 화강암에 존재하는 결 이방성이 간접인장강도에 미치는 영향을 평가하였다. 표준 간접인장시험 및 3개의 서로다른 중공 크기에 대한 중공 간접인장시험을 수행하였다. 2차원 개별요소 수치해석을 통해 간접인장시험에서의 파괴 과정 및 메커니즘을 고찰하였다. 간접인장강도는 화강암의 결에 따라 하드웨이, 그레인, 리프트 면의 순으로 감소하였다. 중공 간접인장강도는 일반 간접인장강도에 비해 2.5~6.4배 정도 크게 나타났으며, 중공 크기가 클수록 크게 나타났다. 중공 시편에 대한 간접인장 파괴 유형은 중공 크기 및 결과 하중방향 각도에 영향을 받는 것으로 나타났다. The purpose of this study is to investigate the influence of cleavages on indirect tensile strength (ITS) of the granite. Brazilian disc tests and ring tests with three different hole sizes were performed. 2D DEM (Discrete Element Method) simulation was employed to further understand the failure process during the tests and the mechanism behind. Results show that ITS decreases across hardway, grain and rift cleavage. Measured average ITS from ring tests is about 2.5 ~ 6.4 times of those measured from Brazilian disc tests, and it decreases with increasing ratio of diameters of inner hole and specimen. Failure pattern in ring tests is influenced by both hole size and relative positions of cleavages parallel and perpendicular to the loading direction.

Synthesis of Silver Nanoplates with Fibronectin Nanofibril Template and Their SERS Applications

Li Wang,Yujing Sun,Yuncheng Cui,Jiku Wang,Zhuang Li 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.2

In this work, a novel strategy is provided to prepare silver nanoplates by a fibronectin (Fn) nanofibril template. First, Fn molecules were controlled to assemble into amyloid-like nanofibrils in highly concentrated ethanol aqueous solution. The resultant nanofibrils could serve as a soft template to direct the formation of silver nanoplates. It is worth noting that the silver nanoplates are excellent surface-enhanced Raman scattering (SERS) substrate with 4-aminothiophenol (4-ATP) molecule as a test probe. This high active SERS substrate can also be used to detect drug molecule, 2-thiouracil with high sensitivity.

A case of Poroelastic Effect in Laboratory Hydraulic Fracturing test on Pocheon Granite

Zhuang, Li,Jung, Sunggyu,Diaz, Melvin,Kim, Kwang Yeom 대한토목학회 2017 대한토목학회 학술대회 Vol.2017 No.10

Effect of Water Infiltration, Injection Rate and Anisotropy on Hydraulic Fracturing Behavior of Granite

Zhuang, Li,Kim, Kwang Yeom,Jung, Sung Gyu,Diaz, Melvin,Min, Ki-Bok Springer-Verlag 2019 Rock mechanics and rock engineering Vol.52 No.2

Assembly of Gold Nanoparticles on Electrospun Polymer Nanofiber Film for SERS Applications

Li Wang,Yujing Sun,Jiku Wang,Zhuang Li 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.1

We report a novel approach for fabricating active surface-enhanced Raman scattering (SERS) substrate for sensitive detection. This approach is based on the assembling of gold nanoparticles (AuNPs) onto the electrospun polycaprolactone (PCL) nanofiber film. The hydrophobic surface of PCL nanofiber film was pretreated using UV-inducing graft polymerization with acrylic acid. Afterwards this PCL nanofiber film was incubated with the AuNP solution to promote the assembly of AuNPs onto the PCL nanofibers and the formation of SERS active substrate. 4-aminothiophenol (4-ATP) molecule was used as a test probe for SERS experiments, indicating that the substrate has high sensitivity to SERS response. Our method has great advantage in term of environment-friendly synthesis, large-scale, high stability and good reproducibility. This highly active SERS substrate can be employed to detect the drug molecule, 2-thiouracil.

Identification of the Genes Involved in the Fruiting Body Production and Cordycepin Formation of Cordyceps militaris Fungus

( Zhuang Li Zheng ),( Xue Hong Qiu ),( Ri Chou Han ) 한국균학회 2015 韓國菌學會誌 Vol.43 No.1

A mutant library of Cordyceps militaris was constructed by improved Agrobacterium tumefaciens-mediated transformation and screened for degradation features. Six mutants with altered characters in in vitro and in vivo fruiting body production, and cordycepin formation were found to contain a single copy T-DNA. T-DNA flanking sequences of these mutants were identified by thermal asymmetric interlaced-PCR approach. ATP-dependent helicase, cytochrome oxidase subunit I and ubiquitin-like activating enzyme were involved in in vitro fruiting body production, serine/threonine phosphatase involved in in vivo fruiting body production, while glucose-methanol-choline oxidoreductase and telomerase reverse transcriptase involved in cordycepin formation. These genes were analyzed by bioinformatics methods, and their molecular function and biology process were speculated by Gene Ontology (GO) analysis. The results provided useful information for the control of culture degeneration in commercial production of C. militaris.

Localized deformation in sands and glass beads subjected to plane strain compressions

Zhuang, Li,Nakata, Yukio,Lee, In-Mo Techno-Press 2013 Geomechanics & engineering Vol.5 No.6

In order to investigate shear behavior of granular materials due to excavation and associated unloading actions, load-controlled plane strain compression tests under decreasing confining pressure were performed under drained conditions and the results were compared with the conventional plane strain compression tests. Four types of granular material consisting of two quartz sands and two glass beads were used to investigate particle shape effects. It is clarified that macro stress-strain behavior is more easily influenced by stress level and stress path in sands than in glass beads. Development of localized deformation was analyzed using photogrammetry method. It was found that shear bands are generated before peak strength and shear band patterns vary during the whole shearing process. Under the same test condition, shear band thickness in the two sands was smaller than that in one type of glass beads even if the materials have almost the same mean particle size. Shear band thickness also decreased with increase of confining pressure regardless of particle shape or size. Local maximum shear strain inside shear band grew approximately linearly with global axial strain from onset of shear band to the end of softening. The growth rate is found related to shear band thickness. The wider shear band, the relatively lower the growth rate. Finally, observed shear band inclination angles were compared with classical Coulomb and Roscoe solutions and different results were found for sands and glass beads.

Knockout of the EgriBLOS2 gene results in the transparent integuments of Ectropis grisescens larvae

Li Jia-Li,Zhuang Xiang-Lin,Yuan Ting-Ting,Cai Xiao-Ming,Luo Zong-Xiu,Bian Lei,Chen Zong-Mao,Li Zhao-Qun,Liu Nai-Yong 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.1

The body colors of insects have evolved specialized roles in body protection, signaling and physiology. In some case, the larvae can camouflage their body colors to adapt the habitants and protect themselves. However, the genetic and molecular basis on larval body colors of the tea geometrid, Ectropis grisescens, remains poorly known. Here, we reported an effect of the lysosome-related organelles complex-1, subunit 2 (EgriBLOS2) gene knockout on larval integuments of E. grisescens, by using a clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system. Combining transcriptomic data and PCR approaches, we first identified the EgriBLOS2 gene from E. grisescens, which encoded 137 amino acids and comprised 3 introns. In the phylogenetic analysis, EgriBLOS2 clustered in the Lepidoptera clade with high conservation to members in other lepidopteran species. Developmental expression profiles revealed that EgriBLOS2 was constantly tran scribed at each stage, in which its expression was significantly lower in 2nd instar larvae than that of other instars. After injecting EgriBLOS2-specific guide RNA and Cas9 messenger RNA into eggs, 70% of larvae showed the translucent integuments in G0 generation, with an emphasis on black splayed patterns in the 2nd and 8th segments of abdomens. However, some typical characteristics of larvae were not obviously changed in mutant instars, such as ocelli, mouthparts and other appendants. This study has unraveled the roles of EgriBLOS2 in the formation of larval integument colors, and provides an alternative strategy for pest management based on the colors in this species.