Investigation on Electrostatic Atomization and Charged Spray Characteristics of Fuel

Wang Junfeng,Hwang Wook Ryo,Luo Tiqian 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

Due to many advantages, electrostatic atomization would be more application potential in the filed of combustion, especially in improving efficiency and decrease emission pollutant. Based on the analysis of fluids charging mechanism, an effective charging equipment for fuel was designed and the charging characteristics of kerosene was obtained and analyzed through experiments in this paper. A kind of electrostatic spray mainly affected by electric field inducted by charging droplets was measured and investigated by PIV. The change law of spray flow field under the action of different charging voltage was presented.

Combined effect of initial biomass density and nitrogen concentration on growth and astaxanthin production of Haematococcus pluvialis (Chlorophyta) in outdoor cultivation

Junfeng Wang,Milton R. Sommerfeld,Congming Lu,Qiang Hu 한국조류학회I 2013 ALGAE Vol.28 No.2

Nitrogen availability and cell density each affects growth and cellular astaxanthin content of Haematococcus pluvialis, but possible combined effects of these two factors on the content and productivity of astaxanthin, especially under outdoor culture conditions, is less understood. In this study, the effects of the initial biomass densities IBDs of 0.1, 0.5, 0.8, 1.5, 2.7, 3.5, and 5.0 g L-1 DW and initial nitrogen concentrations of 0, 4.4, 8.8, and 17.6 mM nitrate on growth and cellular astaxanthin content of H. pluvialis Flotow K-0084 were investigated in outdoor glass column photobioreactors in a batch culture mode. A low IBD of 0.1 g L-1 DW led to photo-bleaching of the culture within 1-2 days. When the IBD was 0.5 g L-1 and above, the rate at which the increase in biomass density and the astaxanthin content on a per cell basis was higher at lower IBD. When the IBD was optimal (i.e., 0.8 g L-1), the maximum astaxanthin content of 3.8% of DW was obtained in the absence of nitrogen, whereas the maximum astaxanthin productivity of 16.0 mg L-1 d-1 was obtained in the same IBD culture containing 4.4 mM nitrogen. The strategies for achieving maximum Haematococcus biomass productivity and for maximum cellular astaxanthin content are discussed.

A Comprehensive Theory of Multi-Aspect Interaction with Cyber Physical Systems

Junfeng Wang,Suihuai Yu 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.3

Interaction with Cyber physical systems (CPSs) greatly differ from traditional human computer interaction. A theory that could explain multi-aspect interaction with cyber physical systems and would facilitate the implementation of highly interactive CPSs is needed. This paper tries to make the first steps in this direction and to provide insights for a necessary new theory. Four kinds of interaction which play a crucial role in the operation of CPSs and four fundamental aspects of interaction (i.e. levels, domains, contexts and modalities) are introduced. The theory explains both the aspects and the various constituents that should be considered. The novelty of the theory is in that it establishes relationships between the four aspects and supports the specification of wishful interaction profiles. Finally, a practical case of robot assisted smart bathroom is used to show how the theory can systematize and rationalize the designing of interaction with CPSs.

Effect of Burkholderia contaminans on Postharvest Diseases and Induced Resistance of Strawberry Fruits

Wang, Xiaoran,Shi, Junfeng,Wang, Rufu The Korean Society of Plant Pathology 2018 Plant Pathology Journal Vol.34 No.5

This study takes strawberry-fruits as the test material and discusses the effect of Burkholderia contaminans B-1 on preventing postharvest diseases and inducing resistance-related substances in strawberry-fruits. Soaking and wound inoculating is performed to analyze the inhibitory effects of different treatment solutions on the gray mold of postharvest strawberry-fruits. The count of antagonistic bacteria colonies in the wound is found, and the dynamic growth of antagonistic bacteria and the pathogenic fungus is observed by electron microscopy. The results indicated that, either by soaking/wound-inoculating, the fermentation and suspension of antagonistic bacteria significantly reduced the incidence of postharvest diseases of strawberry-fruits. With wound inoculation, the inhibition rate of antagonist fermentation and suspension ($1{\times}10^{10}cfu/ml$) respectively reached 77.4% and 66.7%. It also led to a significant increase in the activity of resistance-related enzymes, i.e., phenylalanine ammonia lyase (PAL), 4-coumarate coenzyme A ligase (4CL), cinnamate-4-hydroxylase (C4H) and chalcone isomerase (CHI). On 1 d and 2 d post-treatment, the activity of 4CL was respectively 3.78 and 6.1 times of the control, and on 5 d, the activity of PAL was increased by 4.47 times the control. The treatment of antagonistic bacteria delayed the peaking of cinnamyl-alcohol dehydrogenase (CAD) activity and promoted the accumulation of lignin and total phenols. The antagonistic bacteria could be well colonized in the wounds. On 4-5 d post-inoculation, the count of colonies was $10^8$ times of that upon inoculation. Electronmicroscopy indicated that the antagonistic bacteria delayed the germination of pathogenic spores in the wounds, and inhibited further elongations of the mycelia.

Combined effect of initial biomass density and nitrogen concentration on growth and astaxanthin production of Haematococcus pluvialis (Chlorophyta) in outdoor cultivation

Wang, Junfeng,Sommerfeld, Milton R.,Lu, Congming,Hu, Qiang The Korean Society of Phycology 2013 ALGAE Vol.28 No.2

Nitrogen availability and cell density each affects growth and cellular astaxanthin content of Haematococcus pluvialis, but possible combined effects of these two factors on the content and productivity of astaxanthin, especially under outdoor culture conditions, is less understood. In this study, the effects of the initial biomass densities IBDs of 0.1, 0.5, 0.8, 1.5, 2.7, 3.5, and 5.0 g $L^{-1}$ DW and initial nitrogen concentrations of 0, 4.4, 8.8, and 17.6 mM nitrate on growth and cellular astaxanthin content of H. pluvialis Flotow K-0084 were investigated in outdoor glass column photobioreactors in a batch culture mode. A low IBD of 0.1 g $L^{-1}$ DW led to photo-bleaching of the culture within 1-2 days. When the IBD was 0.5 g $L^{-1}$ and above, the rate at which the increase in biomass density and the astaxanthin content on a per cell basis was higher at lower IBD. When the IBD was optimal (i.e., 0.8 g $L^{-1}$), the maximum astaxanthin content of 3.8% of DW was obtained in the absence of nitrogen, whereas the maximum astaxanthin productivity of 16.0 mg $L^{-1}\;d^{-1}$ was obtained in the same IBD culture containing 4.4 mM nitrogen. The strategies for achieving maximum Haematococcus biomass productivity and for maximum cellular astaxanthin content are discussed.

Effect of Burkholderia contaminans on Postharvest Diseases and Induced Resistance of Strawberry Fruits

Xiaoran Wang,Junfeng Shi,Rufu Wang 한국식물병리학회 2018 Plant Pathology Journal Vol.34 No.5

This study takes strawberry-fruits as the test material and discusses the effect of Burkholderia contaminans B-1 on preventing postharvest diseases and inducing resistance-related substances in strawberry-fruits. Soaking and wound inoculating is performed to analyze the inhibitory effects of different treatment solutions on the gray mold of postharvest strawberry-fruits. The count of antagonistic bacteria colonies in the wound is found, and the dynamic growth of antagonistic bacteria and the pathogenic fungus is observed by electron microscopy. The results indicated that, either by soaking/ wound-inoculating, the fermentation and suspension of antagonistic bacteria significantly reduced the incidence of postharvest diseases of strawberry-fruits. With wound inoculation, the inhibition rate of antagonist fermentation and suspension (1 × 1010 cfu/ml) respectively reached 77.4% and 66.7%. It also led to a significant increase in the activity of resistance-related enzymes, i.e., phenylalanine ammonia lyase (PAL), 4-coumarate coenzyme A ligase (4CL), cinnamate-4-hydroxylase (C4H) and chalcone isomerase (CHI). On 1 d and 2 d post-treatment, the activity of 4CL was respectively 3.78 and 6.1 times of the control, and on 5 d, the activity of PAL was increased by 4.47 times the control. The treatment of antagonistic bacteria delayed the peaking of cinnamyl-alcohol dehydrogenase (CAD) activity and promoted the accumulation of lignin and total phenols. The antagonistic bacteria could be well colonized in the wounds. On 4-5 d post-inoculation, the count of colonies was 108 times of that upon inoculation. Electronmicroscopy indicated that the antagonistic bacteria delayed the germination of pathogenic spores in the wounds, and inhibited further elongations of the mycelia.

MicroRNA-373 Inhibits Cell Proliferation and Invasion via Targeting BRF2 in Human Non-small Cell Lung Cancer A549 Cell Line

Lei Wang,Junfeng Qu,Li Zhou,Fei Liao,Ju Wang 대한암학회 2018 Cancer Research and Treatment Vol.50 No.3

Purpose The purpose of this study was to investigate the biological role and mechanism of miR-373 targeting of TFIIB-related factor 2 (BRF2) in the regulation of non-small cell lung cancer (NSCLC) cells. Materials and Methods miRNA microarray chip analysis of four paired NSCLC and adjacent non-tumor tissues was performed. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were used to detect the expression levels of miR-373 and BRF2 in NSCLC tissues and cell lines. The dual-luciferase reporter method was performed to determine if BRF2 is a target of miR-373. MTT, wound-healing, Transwell, and flow cytometric assays were conducted to examine the proliferation, migration, invasion, and cell cycle progression of NSCLC A549 cells, respectively; western blotting was used to detect the expression of epithelial-mesenchymal transition (EMT)–related proteins. Results The miRNA microarray chip analysis demonstrated that miR-373 was down-regulated in NSCLC tissues, and this result was confirmed by qRT-PCR. Additionally, miR-373 was confirmed to target BRF2. Moreover, miR-373 expression was inversely correlated with BRF2 expression in NSCLC tissues and cell lines; both miR-373 down-regulation and BRF2 up-regulation were strongly associated with the clinicopathological features and prognosis of NSCLC patients. In vitro, overexpression of miR-373 markedly inhibited cell proliferation, migration, and invasion; up-regulated the expression of E-cadherin; and down-regulated the expression of N-cadherin and Snail in A549 cell. Knockdown BRF2 by siRNA resulted in effects similar to those caused by overexpression of miR-373. Conclusion MiR-373 is decreased in NSCLC, and overexpression of miR-373 can suppress cell EMT, and inhibit the proliferation, migration, and invasion of NSCLC A549 cells by targeting BRF2.

On-the-fly Data Compression for Efficient TCP Transmission

( Min Wang ),( Junfeng Wang ),( Xuan Mou ),( Sunyoung Han ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.3

Data compression at the transport layer could both reduce transmitted bytes over network links and increase the transmitted application data (TCP PDU) in one RTT at the same network conditions. Therefore, it is able to improve transmission efficiency on Internet, especially on the networks with limited bandwidth or long delay links. In this paper, we propose an on-the-fly TCP data compression scheme, i.e., the TCPComp, to enhance TCP performance. This scheme is primarily composed of the compression decision mechanism and the compression ratio estimation algorithm. When the application data arrives at the transport layer, the compression decision mechanism is applied to determine which data block could be compressed. The compression ratio estimation algorithm is employed to predict compression ratios of upcoming application data for determining the proper size of the next data block so as to maximize compression efficiency. Furthermore, the assessment criteria for TCP data compression scheme are systematically developed. Experimental results show that the scheme can effectively reduce transmitted TCP segments and bytes, leading to greater transmission efficiency compared with the standard TCP and other TCP compression schemes.

HIGH-ORDERED AND ULTRA-SENSITIVE PARTICLE-IN-BOWL METALLIC ARRAYS FOR SURFACE ENHANCED RAMAN SPECTROSCOPY

DI DI,PEITAO DONG,XUEZHONG WU,CHAOGUANG WANG,JIAN CHEN,HAOXU WANG,SHENGYI LI,JUNFENG WANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.4

High-ordered particle-in-bowl (PIB) arrays are developed in this paper for surface enhancedRaman spectroscopy (SERS). A heterogeneous shadow mask, composing of the chrome (Cr) layerand colloid residues, is used to fabricate the silicon (Si) template from where the PIB arrays¯nally lift-o®. The ¯nite di®erence time domain (FDTD) method is employed to investigate theRaman enhancement mechanism of this PIB architecture. The electromagnetic (EM) ¯eld tendsto concentrate in the gap between the bowl and the particle forming the \hot spots". Theenhancement factor (EF) of the EM ¯eld is about 70 with an excitation wavelength of 785 nm. The Raman measurements validate the EM calculation of the PIB arrays. The EF is about1 : 12 ? 10 7 using Rodamine 6G (R6G) as probe molecule. The proposed PIB array is high-orderedin morphology and ultra-sensitive in Raman measurement, providing an ideal substrate forSERS-based bio-chemical sensing, disease diagnosis and analytical chemistry.

Roles of RpoS in Yersinia pseudotuberculosis stress survival, motility, biofilm formation and type VI secretion system expression

Jingyuan Guan,Xiao Xiao,Shengjuan Xu,Fen Gao,Jianbo Wang,Tietao Wang,Yunhong Song,Junfeng Pan,Xihui Shen,Yao Wang 한국미생물학회 2015 The journal of microbiology Vol.53 No.9

RpoS (σS), the stationary phase/stress σ factor, controls the expression of a large number of genes involved in cellular responses to a variety of stresses. However, the role of RpoS appears to differ in different bacteria. While RpoS is an important regulator of flagellum biosynthesis, it is associated with biofilm development in Edwardsiella tarda. Biofilms are dense communities formed by bacteria and are important for microbe survival under unfavorable conditions. The type VI secretion system (T6SS) discovered recently is reportedly associated with several phenotypes, ranging from biofilm formation to stress sensing. For example, Vibrio anguillarum T6SS was proposed to serve as a sensor for extracytoplasmic signals and modulates RpoS expression and stress response. In this study, we investigated the physiological roles of RpoS in Yersinia pseudotuberculosis, including bacterial survival under stress conditions, flagella formation, biofilm development and T6SS expression. We found that RpoS is important in resistance to multiple stressors–including H2O2, acid, osmotic and heat shock–in Y. pseudotuberculosis. In addition, our study showed that RpoS not only modulates the expression of T6SS but also regulates flagellum formation by positively controlling the flagellar master regulatory gene flhDC, and affects the formation of biofilm on Caenorhabditis elegans by regulating the synthesis of exopolysaccharides. Taken together, these results show that RpoS plays a central role in cell fitness under several adverse conditions in Y. pseudotuberculosis.