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.

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...

Behavior of concrete-filled round-ended steel tubes under bending

Fa-xing Ding,Tao Zhang,Liping Wang,Lei Fu 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.25 No.4

The objective of this paper is to investigate the flexural behavior of concrete-filled round-ended steel tubes (CFRTs) under bending. Beam specimens were tested to investigate the mechanical behavior of the CFRTs, including four CFTs with different concrete strengths and steel ratios, and three CFRTs with varied aspect ratios. The load vs. deflection relationships and the failure modes for CFRTs were analyzed in detail. The composite action between the core concrete and steel tube was also discussed and examined based on the experimental results. In addition, ABAQUS program was used to develop the full-scale finite element model and analyze the effect of different parameters on the moment vs. curvature curves of the CFRTs bending about the major and minor axis, respectively. Furthermore, design formulas were proposed to estimate the ultimate moment and the flexural stiffness of the CFRTs, and the simplified theoretical model of the moment vs. curvature curves was also developed. The predicted results showed satisfactory agreement with the experimental and FE results. Finally, the differences of the experimental, FE and predicted results using the existing codes were illustrated.

Unloading Deformation of Rock Slopes Under High Geo-stress Condition

( Fa Quan Wu ),( Shen Wen Qi ),( Tong Liu ) 대한지질공학회 2007 국제학술발표회 논문집 Vol.2007 No.-

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.

Flexural stiffness of steel-concrete composite beam under positive moment

Fa-Xing Ding,Jing Liu,Xuemei Liu,Feng-Qi Guo,Li-Zhong Jiang 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.20 No.6

This paper investigates the flexural stiffness of simply supported steel-concrete composite I-beams under positive bending moment through combined experimental, numerical, and different standard methods. 14 composite beams are tested for experimental study and parameters including shear connection degree, transverse and longitudinal reinforcement ratios, loading way are also investigated. ABAQUS is employed to establish finite element (FE) models to simulate the flexural behavior of composite beams. The influences of a few key parameters, such as the shear connection degree, stud arrangement, stud diameter, beam length, loading way, on the flexural stiffness is also studied by parametric study. In addition, three widely used standard methods including GB, AISC, and British standards are used to estimate the flexural stiffness of the composite beams. The results are compared with the experimental and numerical results. The findings have provided comprehensive understanding of the flexural stiffness and the modelling of the composite beams. The results also indicate that GB 50017-2003 could provide better results in comparison to the other standards.

Improved Enantioselective Hydrolysis of Racemic Ethyl-2,2- dimethylcyclopropanecarboxylate Catalyzed by Modified Novozyme 435

Fa-yong Liang,Jin Huang,Jun-yao He,Pu Wang 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.5

S-(+)-2,2-dimethylcyclopropanecarboxylic acid (S-(+)-DMCPA) is a key chiral intermediate for the synthesis of Cilastatin. The enzymatic preparation of S-(+)-DMCPA has attracted much attention. In order to improve the activity and stability of Novozyme 435 for enzymatic preparation of S-(+)-DMCPA from 2,2-dimethylcyclopropane carboxylate (DMCPE), the glutaraldehyde modification for Novozyme 435 was investigated and the glutaraldehydemodified Novozyme 435 was used as biocatalyst for the synthesis of S-(+)-DMCPA. The results showed that the modified Novozyme 435 had a better reusing merit than unmodified enzyme. The maximum specific activity was obtained by modification Novozyme 435 with 1.5%glutaraldehyde solution under the conditions of shaking at 200 rpm and 30oC for 45 min. The optimal enzymatic hydrolysis conditions for glutaraldehyde-modified Novozyme 435 were also confirmed. The optimized hydrolytic reaction mixture contained 10 mL potassium phosphate buffer (1.0 mol/L, pH 7.6), 90 mg of DMCPE and 160 mg of glutaraldehyde-modified enzyme, and the reaction was performed at 30oC and 200 rpm for 52 h. The reusing efficiency of modified Novozyme 435 was further evaluated. Under the optimal conditions, the modified enzyme remained 76.0% of its original yield after 10 times reuse,but the optical purity of the product kept intact; whereas the yield of unmodified enzyme reduced to 20.8% of its initial value and the ee value of product decreased a lot to 90.7% after 7 times recycle. These results showed that the modified Novozyme 435 was more cost-effective for the preparation of S-(+)-DMCPA in industrial application.

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.

Catheter Ablation of Ventricular Tachycardia/Fibrillation in a Patient with Right Ventricular Amyloidosis with Initial Manifestations Mimicking Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

Fa-Po Chung,Yenn-Jiang Lin,Ling Kuo,Shih-Ann Chen 대한심장학회 2017 Korean Circulation Journal Vol.47 No.2

Differentiating arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) from other cardiomyopathies is clinically important but challenging. Although the modified Task Force Criteria can facilitate diagnosis of ARVD/C according to clinical manifestations, histopathological examination plays a pivotal role in excluding other diseases that can mimic ARVD/C. Here, we report a patient with amyloidosis that initially presented similarly to ARVD/C. The diagnosis was confirmed by endomyocardial biopsy, and catheter ablation eliminated the ventricular tachyarrhythmias through an epicardial approach.