Vapor-liquid equilibrium in low pressure water+congener mixtures

Claudio Alonso Faúndez,Felipe Andrés Urbina,José Omar Valderrama 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.5

Vapor-liquid equilibrium in binary water+congeners mixtures found in alcoholic distillation has been analyzed using the Peng-Robinson equation of state and one of the most popular modern mixing rules, the Wong-Sandler model. Accurate modeling of the concentration of congeners (substances different from ethanol and water) in the vapor phase is of special importance because these substances give some special characteristics of flavor and aroma to the final distilled spirit and also because their concentrations are regulated by law. In the Wong-Sandler mixing rules the van Laar model for the Gibbs excess energy has been used. The type of model used in this work is commonly used to correlate high pressure phase equilibrium and has not yet been used to treat complex low pressure water+congener mixtures as done in this work. Eight binary water+congeners mixtures have been considered for analysis. Comparison with available literature data is done and the accuracy of the model to correlate the pressure and the vapor phase concentration of the congeners is discussed. It is concluded that the model used is accurate enough for distillation analysis, modeling and simulation.

Evaluation of Antibacterial Activity against Salmonella Enteritidis

Gaëlle Legendre,Fabienne Faÿ,Isabelle Linossier,Karine Vallée-Réhel 한국미생물학회 2011 The journal of microbiology Vol.49 No.3

Salmonella enterica serovar Enteritidis is a well-known pathogenic bacterium responsible for human gastrointestinal enteritis mainly due to the consumption of eggs and egg-products. The first aim of this work was to study several virulence factors of a strain isolated from egg content: SEovo. First, bacterial growth was studied at several temperatures and cell morphology was observed by scanning electronic microscopy. These experiments showed Salmonella’s ability to grow at low temperatures and to produce exoproducts. Next, Salmonella motility was observed performing swimming, twitching, and swarming tests. Results indicated a positive flagellar activity and the cell ability to differentiate and become hyperflagellated under specific conditions. Moreover, SEovo adherence and biofilm formation was carried out. All of these tests enabled us to conclude that SEovo is a potential pathogen, thus it can be used as a model to perform antibacterial experiments. The second part of the study was dedicated to the evaluation of the antibacterial activity of different molecules using several methods. The antibacterial effect of silver and copper aluminosilicates was tested by two different kinds of methods. On the one hand, the effect of these two antibacterial agents was determined using microbiological methods: viable cell count and agar-well diffusion. And on the other hand, the antibacterial activity was evaluated using CLSM and SYTO Red/SYTOX Green dyeing. CLSM allowed for the evaluation of the biocide on sessile cells, whereas the first methods did not. Results showed that adhered bacteria were more resistant than planktonic counterparts and that CLSM was a good alternative to evaluate antibacterial activity on fixed bacteria without having to carry out a removing step.

The Effects of Temperature on Daily Electricity Demand Profile Based on Principal Component Analysis

Fa-Zheng Chu(저법정),Kwang-Hui Lee(이광휘) 대한전자공학회 2015 대한전자공학회 학술대회 Vol.2015 No.11

Outside temperature is the inevitable factor during modeling for electricity demand. In this paper, we deploy principal components analysis (PCA) method on the daily electricity demand profile to investigate the effect of temperatures. According to the data sets we used from New York state, daily electricity demand profile on 24 hours resolution could be reduced as two components vector and each component shows a clear manner to response to temperature changes. According to our investigation, the first, considering a totally different pattern of demand response to high temperature, modeling for daily electricity demand should treat electricity demand in high temperature separately. The second, because of showing a parallel shift on the transformed demand profile, even the daily electricity demand profile of no working day is much different from the working days", it is possible to take the manner of response to temperature change as the same.

Emulsified oil foam for improving the flowability of heavy oil in wellbore under high salinity environments

Fa-yang Jin,Song Wang,Wan-Fen Pu,Cheng-dong Yuan,Lei Wang,Ke-xing Li,Can Gong 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.39 No.-

Emulsified oil foam was investigated to improve the flowability of heavy oil under high salinityenvironment of 23 104 mg/L. Sixteen foaming agents were used to determine an applicableformulation. The factors affecting the formation and stability of the emulsified oil foam were evaluated,including oil viscosity, oil–water ratio, foaming agent concentration, stirring rate and time, andtemperature. The microgram of emulsified oil foam was analyzed by polarizing microscope. The resultsshowed that stable pseudo-emulsion film was built. The considerable dynamic viscosity-reducing ratesin different depth in wellbore were obtained according to pressure differential method in long tubephysical simulation experiments.

Research on surface-modification of Nano-TiO₂ by span 60

Fa-Tang Li,Di-Shun Zhao,Qing-Zhi Luo,Rui-Hong Liu,Rong Yin 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.4

Nano-TiO2 is likely to agglomerate easily because of its high surface energy, which decreases its photocatalytic activity. Also the hydrophilic nature of the TiO2 restricts its usefulness in organic materials and in solution. Nano-TiO2 particles were modified by Span 60 in anhydrous ethanol in this paper. The powders were characterized by Fourier transform infrared (FTIR) and transmission electron microscopy (TEM). The results showed that there were characteristic absorption peaks of Span 60 from the surface of TiO2 nanoparticles and the degree of aggregation of TiO2 particles has been decreased effectively after modification. The surface of TiO2 changed from hydrophilic to hydrophobic. Nano-TiO2 is likely to agglomerate easily because of its high surface energy, which decreases its photocatalytic activity. Also the hydrophilic nature of the TiO2 restricts its usefulness in organic materials and in solution. Nano-TiO2 particles were modified by Span 60 in anhydrous ethanol in this paper. The powders were characterized by Fourier transform infrared (FTIR) and transmission electron microscopy (TEM). The results showed that there were characteristic absorption peaks of Span 60 from the surface of TiO2 nanoparticles and the degree of aggregation of TiO2 particles has been decreased effectively after modification. The surface of TiO2 changed from hydrophilic to hydrophobic.

Nanocomposite Ni–TiN coatings prepared by ultrasonic electrodeposition

Fa-feng Xia,Meng-hua Wu,Fan Wang,Zhen-yuan Jia,Ai-leng Wang 한국물리학회 2009 Current Applied Physics Vol.9 No.1

Nanocomposite Ni–TiN coatings were prepared by ultrasonic electrodeposition and the effects of ultrasonication on the coatings were studied. X-ray diffraction analysis was utilized to detect the crystalline and amorphous characteristics of the composite coatings. The surface morphology and metallurgical structure were observed by scanning electron microscopy, high-resolution transmission electron microscopy and scanning probe microscopy. The results showed that ultrasonication had great effects on TiN nanoparticles in composite coatings. The moderate ultrasonication conduced to homogeneous dispersion of TiN particles in the coatings. Moreover, the TiN nanoparticles that entered and homogeneously dispersed in the composite coating led to an increase in the number of nuclei for nucleation of nickel grains and inhibition of grain growth. Therefore, the introduction of ultrasonication and TiN nanoparticles resulted in the formation of smaller nickel grains. The average grain diameter of TiN particles was 33 nm, while Ni grains measured approximately 53 nm. Nanocomposite Ni–TiN coatings were prepared by ultrasonic electrodeposition and the effects of ultrasonication on the coatings were studied. X-ray diffraction analysis was utilized to detect the crystalline and amorphous characteristics of the composite coatings. The surface morphology and metallurgical structure were observed by scanning electron microscopy, high-resolution transmission electron microscopy and scanning probe microscopy. The results showed that ultrasonication had great effects on TiN nanoparticles in composite coatings. The moderate ultrasonication conduced to homogeneous dispersion of TiN particles in the coatings. Moreover, the TiN nanoparticles that entered and homogeneously dispersed in the composite coating led to an increase in the number of nuclei for nucleation of nickel grains and inhibition of grain growth. Therefore, the introduction of ultrasonication and TiN nanoparticles resulted in the formation of smaller nickel grains. The average grain diameter of TiN particles was 33 nm, while Ni grains measured approximately 53 nm.

Mechanical behavior of outer square inner circular concrete-filled dual steel tubular stub columns

Fa-Xing Ding,Wenjun Wang,Xue-mei Liu,Liping Wang,Yi Sun 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.3

The mechanical behavior of the outer square inner circular concrete-filled dual steel tubular (SCCFT) stub columns under axial compression is investigated by means of experimental research, numerical analysis and theoretical investigation. Parameters such as diameter ratio, concrete strength and steel ratio were discussed to identify their influence on the mechanical properties of SCCFT short columns on the basis of the experimental investigation of seven SCCFT short columns. By establishing a finite element model, nonlinear analysis was performed to discuss the longitudinal and transverse stress of the dual steel tubes. The longitudinal stress characteristics of the core and sandwich concrete were also analyzed. Furthermore, the failure sequence was illustrated and the reasonable cross-section composition of SCCFT stub column was proposed. A formula to predict the axial load capacity of SCCFT stub column was advanced and verified by the results from experiment and the finite element.

Plants, Germs, and Animals: They Want to Be in History, Too!

Fa-ti Fan 고려대학교 민족문화연구원 2014 Cross-Currents Vol.- No.10

Environmental history, history of science, and animal studies are emerging trends in the historiography of modern East Asia, for good reason. Environmental concerns are prominent in the region today, and environmental factors are important to understanding its history. Science (together with technology) has been held up as the benchmark of modernity in East Asia for more than a century and has been fundamental to visions of the modern nation (consider, for example, Mr. Science in China’s May Fourth Movement). Animal studies is the newest of these trends. This field has gained notice only in recent years, yet there are signs that it is becoming a popular topic...

Overexpression of a Nitrile Hydratase from Klebsiella oxytoca KCTC 1686 in Escherichia coli and Its Biochemical Characterization

Fa-Mou Guo,Jian-ping Wu,Li-Rong Yang,Gang Xu 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.6

The putative Co-type nitrile hydratase (NHaseK, consisting of α- and β-subunits) genes and the putative activator (17K) gene adjacent to the β subunit region were cloned from Klebsiella oxytoca KCTC 1686. 17K is essential for the functional expression of recombinant NHaseK in Escherichia coli; however, the expression level of 17K was very low when the 17K gene and NHaseK structural genes were expressed as a gene cluster in E. coli BL21(DE3). To improve the 17K expression level and NHaseK activity, the expression cassette was redesigned by placing the 17K gene and NHaseK structural genes under the control of different promoters in the pETDuet-1 expression vector, co-expressing the 17K gene with the gene cluster in a double plasmid or a single plasmid with a double promoter, and introducing an efficient Shine- Dalgarno sequence 5' to the17K gene. The specific activity of NHaseK was improved when 17K was co-expressed with the gene cluster, whereas the production of NHaseK protein decreased. The maximum activity was achieved when an efficient Shine-Dalgarno sequence was introduced 5' to the 17K gene: the expression level of 17K was significantly improved and the expression level of NHaseK did not decrease significantly. The maximum activity was about 63,480 ± 1915.6 U/L broth towards 3-Cyanopyridine. Recombinant NHaseK could hydrolyze a wide range of aliphatic, aromatic, and heterocyclic nitriles, and convert racemic nitriles to the corresponding S-amides, with E values ranging from 9 to 17. The enzyme had a temperature optimum of 35°C and exhibited remarkably stability below 35°C.

Linear Pole-placement Anti-windup Control for Input Saturation Nonlinear System Based on Takagi Sugeno Fuzzy Model

Fa Guang Wang,Hongmei Wang,박승규,Xue-Song Wang 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.6

An anti-windup controller for multi-input nonlinear system is proposed in this paper. The proposedmethod does not need to calculate every time for every fuzzy rules comparing with traditional linear pole placementof T-S(Takagi-Sugeno) fuzzy. This means fewer LMIs(linear matrix inequality) will be needed and its solutionwill be guaranteed as much as possible. For different saturation limit, different D-stable disk center and radius ofpole placement can be selected to eliminate input saturation effect directly. Nonlinear system will be transferredto T-S fuzzy model first. Then, by employing a series of transition matrix, nonlinear system will be transferredinto a nearly linear format accompanied by a nonlinear part. Finally, by designing a proper controller, linear poleplacement method can be used and the controller gains can be calculated out with LMIs.