Research on the Security Threats and Strategy in Smart Grid Application

Ding, Guanjun,Fan, Bangkui,Long, Teng,Lan, Haibin,Wang, Jing,Chen, Zhiyong The Korean Institute of Electrical Engineers 2014 The Journal of International Council on Electrical Vol.4 No.3

The smart grid is evolving rapidly from a relatively isolated environment to an opened one. The adoption of information and communication technologies can make greater connectivity and interoperability between components. However, the increased connectivity also brings the challenge to security. First of all, in allusion to the current study on security threats to smart grid simple and deficient, the paper induces and analyzes it thoroughly, which can also correct some misunderstanding in a certain degree, from the view of system level, services, confidentiality and so on. Secondly, based on the analysis of security threats, the paper constructs the security strategy for smart grid. It consists of four steps, which are discussed detailedly one by one. It can provide the protection effectively. Finally, relevant conclusions are made.

Purification and Structure Analysis of Mycolic Acids in Corynebacterium glutamicum

Yang Yang,Feng Shi,Guanjun Tao,Xiaoyuan Wang 한국미생물학회 2012 The journal of microbiology Vol.50 No.2

Corynebacterium glutamicum is widely used for producing amino acids. Mycolic acids, the major components in the cell wall of C. glutamicum might be closely related to the secretion of amino acids. In this study, mycolic acids were extracted from 5 strains of C. glutamicum, including ATCC 13032,ATCC 13869, ATCC 14067, L-isoleucine producing strain IWJ-1, and L-valine producing strain VWJ-1. Structures of these mycolic acids were analyzed using thin layer chromatography and electrospray ionization mass spectrometry. More than twenty molecular species of mycolic acid were observed in all 5 strains. They differ in the length (20–40carbons) and saturation (0–3 double bonds) of their constituent fatty acids. The dominant species of mycolic acid in every strain was different, but their two hydrocarbon chains were similar in length (14–18 carbons), and the meromycolate chain usually contained double bonds. As the growth temperature of cells increased from 30°C to 34°C, the proportion of mycolic acid species containing unsaturated and shorter hydrocarbon chains increased. These results provide new information on mycolic acids in C. glutamicum,and could be useful for modifying the cell wall to increase the production of amino acids.

Intergeneric Hybridization between Streptomyces albulus and Bacillus subtilis Facilitates Production of ε-Poly-L-lysine from Corn Starch Residues

Shu Li,Nan Wang,Zongjun Du,Guanjun Chen 한국생물공학회 2018 Biotechnology and Bioprocess Engineering Vol.23 No.5

Intergeneric hybridization between S.albulus and B. subtilis to produce ε-poly-L-lysine (ε-PL) from corn starch residues (CSR) was investigated in this study. One hybrid, designated S. albulus LS-84, which incorporated the protease gene from B. subtilis, could effectively utilize the protein in CSR as a nitrogen source. In fed-batch fermentation, LS-84 produced 32.6 g/L ε-PL in the presence of 20 g/L CSR. This was an increase of 256.1% compared to that of the parent strain S. albulus LS-01. The rapid hydrolysis of CSR by protease caused rapid growth for LS- 84, which allowed higher respiratory activity. As a result, activities of several key enzymes in LS-84 were higher than those in LS-01; additionally, the content of several intracellular amino acids, such as Asp, Glu, and Arg, was also much higher in LS-84. Therefore, intergeneric hybridization between S. albulus and B. subtilis to produce ε-PL from CSR is an economical method for effective utilization of waste resources.

Microstructure and strength of zirconia/stainless steel joints prepared by pressureless active brazing

Guiwu Liu,Hongjie Wang,Jianfeng Yang,Tianjian Lu,Guanjun Qiao 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.4

ZrO2 ceramic/stainless steel joints were fabricated by pressureless brazing using a Ag-Cu filler metal and a TiH2 powder precoating. The microstructure and microchemistry of the joint cross section were characterized and analyzed by means of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The effects of brazing conditions on the joint shear strength were also investigated. The results showed that there existed three zones with distinct microstructural differences crossing the brazing interlayer. A reaction layer and a Ti-rich sublayer were formed at the ZrO2/filler interface. The influence of the brazing temperature on the joint strength was more remarkable than that of the holding time. In the experimental condition ranges, the joint strength first increased, and the maximum shear strength was over 90MPa with the optimized condition. Most of the joint fractures developed in the ceramic matrix near the ceramic/filler interface. ZrO2 ceramic/stainless steel joints were fabricated by pressureless brazing using a Ag-Cu filler metal and a TiH2 powder precoating. The microstructure and microchemistry of the joint cross section were characterized and analyzed by means of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The effects of brazing conditions on the joint shear strength were also investigated. The results showed that there existed three zones with distinct microstructural differences crossing the brazing interlayer. A reaction layer and a Ti-rich sublayer were formed at the ZrO2/filler interface. The influence of the brazing temperature on the joint strength was more remarkable than that of the holding time. In the experimental condition ranges, the joint strength first increased, and the maximum shear strength was over 90MPa with the optimized condition. Most of the joint fractures developed in the ceramic matrix near the ceramic/filler interface.

Nonradiative energy transfer between colloidal quantum dot-phosphors and nanopillar nitride LEDs.

Zhang, Fan,Liu, Jie,You, Guanjun,Zhang, Chunfeng,Mohney, Suzanne E,Park, Min Joo,Kwak, Joon Seop,Wang, Yongqiang,Koleske, Daniel D,Xu, Jian Optical Society of America 2012 Optics express Vol.20 No.2

<P>We present in this communication our study of the nonradiative energy transfer between colloidal quantum dot (QD) phosphors and nitride nanopillar light emitting diodes (LEDs). An epitaxial p-i-n InGaN/GaN multiple quantum-well (QW) heterostructure was patterned and dry-etched to form dense arrays of nanopillars using a novel etch mask consisting of self-assembled In3Sn clusters. Colloidal QD phosphors have been deposited into the gaps between the nanopillars, leading to sidewall coupling between the QDs and InGaN QW emitters. In this approach, close QW-QD contact and a low-resistance design of the LED contact layer were achieved simultaneously. Strong non-radiative energy transfer was observed from the InGaN QW to the colloidal QD phosphors, which led to a 263% enhancement in effective internal quantum efficiency for the QDs incorporated in the nanopillar LEDs, as compared to those deposited over planar LED structures. Time-resolved photoluminescence was used to characterize the energy transfer process between the QW and QDs. The measured rate of non-radiative QD-QW energy-transfer agrees well with the value calculated from the quantum efficiency data for the QDs in the nanopillar LED.</P>

Investigation of flexural strength and porosity of porous Si₃N₄ ceramics through orthogonal experimental design

Juanli Yu,Jianmei Hou,Jian Zhang,Guanjun Qiao,Zhihao Jin,Hongjie Wang 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.6

Porous Si3N4 ceramics by a gel casting preparation route have received considerable attention because of their excellent performance. In this paper, orthogonal experimental design L16(45) was used to investigate the preparation of porous Si3N4 ceramics by a gelcasting technique. Three variables including solid loading, monomer content and the ratio of monomers were studied. Through range analysis and variance analysis, the results suggest that the ratio of monomers has a significant influence on both the flexural strength and porosity of Si3N4 sintered bodies. For the flexural strength of a Si3N4 sintered body, the order of significance levels was as follows: the ratio of monomers, solid loading and monomer content. For the porosity of a Si3N4 sintered body, the order of significance levels was as follows: the ratio of monomers, monomer content and solid loading. The experimental results suggest also that solid loading has an optimum value where the flexural strength can achieve a maximum value. Porous Si3N4 ceramics by a gel casting preparation route have received considerable attention because of their excellent performance. In this paper, orthogonal experimental design L16(45) was used to investigate the preparation of porous Si3N4 ceramics by a gelcasting technique. Three variables including solid loading, monomer content and the ratio of monomers were studied. Through range analysis and variance analysis, the results suggest that the ratio of monomers has a significant influence on both the flexural strength and porosity of Si3N4 sintered bodies. For the flexural strength of a Si3N4 sintered body, the order of significance levels was as follows: the ratio of monomers, solid loading and monomer content. For the porosity of a Si3N4 sintered body, the order of significance levels was as follows: the ratio of monomers, monomer content and solid loading. The experimental results suggest also that solid loading has an optimum value where the flexural strength can achieve a maximum value.

A Modified NHL-BFM-95 Regimen Produces Better Outcome Than HyperCVAD in Adult Patients with T-Lymphoblastic Lymphoma, a Two-Institution Experience

Chun Li,Zhi-Jun Wuxiao,Xiaoqin Chen,Guanjun Chen,Yue Lu,Zhongjun Xia,Yang Liang,Hua Wang 대한암학회 2020 Cancer Research and Treatment Vol.52 No.2

Purpose Lymphoblastic lymphoma (LBL) is an invasive neoplasm of precursor T-cell or B-cell lineage. A broadly accepted standard treatment for adult LBL has not yet been defined. Materials and Methods To address this issue, we compared two chemotherapy regimens: a modified non-Hodgkin lymphoma Berlin–Frankfurt–Mu!nster-95 (NHL-BFM-95) regimen and HyperCVAD/MA. This retrospective study consecutively enrolled 207 adult LBL patients at two hospitals from 2000 to 2018. Univariate and multivariate analysis were used to assess prognostic factors. Results In the present study, most clinical characteristics were similar between the two treatment groups except for age and lactate dehydrogenase (LDH) level. Patients treated with modified NHL-BFM-95 regimen tended to be younger and with elevated LDH level. The modified NHLBFM- 95 regimen produced better treatment outcomes than those with HyperCVAD/MA in patients with T-LBL or patients < 40 years. Treatment with HyperCVAD/MA, high Eastern Cooperative Oncology Group scores, and bone marrow involvement were independent risk factors in T-LBL. No patients interrupted treatment for severe adverse events. Conclusion The results suggested that the modified regimen is well-tolerated and can produce the promising outcomes in patients with T-LBL or patients < 40 years.

Low-Cost Flexible Strain Sensor Based on Thick CVD Graphene

Bailiang Chen,Ying Liu,Guishan Wang,Xianzhe Cheng,Guanjun Liu,Jing Qiu,Kehong Lv 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.11

Flexible strain sensors, as the core member of the family of smart electronic devices, along with reasonable sensing range and sensitivity plus low cost, have rose a huge consumer market and also immense interests in fundamental studies and technological applications, especially in the field of biomimetic robots movement detection and human health condition monitoring. In this paper, we propose a new flexible strain sensor based on thick CVD graphene film and its low-cost fabrication strategy by using the commercial adhesive tape as flexible substrate. The tensile tests in a strain range of ~30% were implemented, and a gage factor of 30 was achieved under high strain condition. The optical microscopic observation with different strains showed the evolution of cracks in graphene film. Together with commonly used platelet overlap theory and percolation network theory for sensor resistance modeling, we established an overlap destructive resistance model to analyze the sensing mechanism of our devices, which fitted the experimental data very well. The finding of difference of fitting parameters in small and large strain ranges revealed the multiple stage feature of graphene crack evolution. The resistance fallback phenomenon due to the viscoelasticity of flexible substrate was analyzed. Our flexible strain sensor with low cost and simple fabrication process exhibits great potential for commercial applications.

Amplification of transglutaminase 2 enhances tumor-promoting inflammation in gastric cancers

Cho Sung-Yup,오유미,Jeong Eui Man,박상희,Dakeun Lee,Xiaorui Wang,Qiqi Zeng,Hongyu Qin,Fang Hu,Hui Gong,Xi Liu,Guanjun Zhang,나득채,이지은,채지수,서윤석,공성호,Hyuk-Joon Lee,Jong-Il Kim,박한수,Chengsheng Zhang,양한광,Charles Lee 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

Tumor-promoting inflammation is a hallmark of cancer and is highly associated with tumor progression, angiogenesis, and metastasis. Tumor-associated macrophages (TAMs) are major drivers of tumor-promoting inflammation, but due to the complexity of the tumor microenvironment, the detailed regulatory mechanisms are still under investigation. Here, we investigated a novel role for transglutaminase 2 (TGM2) in the development of tumor-promoting inflammation and recruitment of TAMs to gastric cancer (GC) tissues. When estimated by array comparative genomic hybridization and droplet digital PCR, the copy numbers of the TGM2 gene were amplified in 13.6% (14/103) of GC patients and positively associated with TGM2 expression. Gene set enrichment analysis of expression microarray data for GC samples with high or low TGM2 expression showed that increased TGM2 expression was associated with tumor-promoting inflammation in GC. In addition, the expression of TGM2 was correlated with the expression of markers for macrophages, neutrophils, blood vessels, and lymphatic vessels. Overexpression of TGM2 in GC cells augmented the IL-1β-induced secretion of macrophage-recruiting chemokines and NF-κB activation. TGM2 protein levels were associated with the expression levels of the macrophage marker CD163 in human GC tissue samples. Moreover, GC patients with high expression of TGM2 had a worse prognosis than those with low expression of TGM2. These results suggest TGM2 as a novel regulator of the tumor microenvironment of GC and provide a promising target for constraining tumor-promoting inflammation.

Indoor feeding combined with restricted grazing time improves body health, slaughter performance, and meat quality in Huang-huai sheep

Huang Yafeng,Zhao Mengyu,Zhang Xiaoan,Wei Huiqing,Liu Lumeng,Zhang Zi Jun,Cheng Xiao,Wang Guanjun,Ren Chunhuan 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.11

Objective: The aim of this study was to evaluate the effects of three feeding systems, i.e., indoor feeding (CON), indoor feeding with 4-h daily access to grazing artificial pasture (ITGP), and indoor feeding with 8-h daily access to grazing artificial pasture (IEGP), on the plasma antioxidant and immunological capacity, slaughter characteristics, meat quality and economic efficiency of Huang-huai lambs. Methods: Thirty-three healthy Huang-huai rams with similar body weight (approximately 5 mo of age, 28.96±1.01 kg) were assigned equally to three experimental groups. When finished fattening, six lambs from each group were collect blood samples for plasma analyses and then slaughtered to determine slaughter characteristics and obtain biceps brachii muscle for further analysis of meat quality and fatty acid profile. Results: Compared to CON group, animals submitted to ITGP and IEGP groups resulted in greater contents of serum glutathione peroxidase, immunoglobulins (IgA, IgG, and IgM), polyunsaturated fatty acids (PUFA), n-6 PUFA, and PUFA/saturated fatty acid (FA) ratio and lower palmitic /oleic acid ratio (p<0.05). Moreover, animals in ITGP group exhibited a higher (p<0.05) loin eye area, content of meat crude protein (CP), and eicosetrienoic acid compared to CON group, while slaughter performance was superior (p<0.05) to that of the IEGP group. The economic efficiency of ITGP group was 70.12% higher than that of CON group, while the IEGP group exhibited a decrease of 92.54% in economic efficiency compared to the CON group. Conclusion: Restricted grazing time combined with indoor feeding was more effective in conferring superior body health, carcass traits and economic efficiency in Huang-huai lambs, as well as higher CP content and healthier FA composition in the resulting meat.