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Comparison of Cellular Automaton and Phase Field Models to simulate dendrite Growth in Hexagonal Crystals

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Journal of Materials science & Technology 2012年第2期28卷 137-146页

作者： Mohsen Asle Zaeem Hebi Yin sergio d. Felicelli Center for Advanced Vehicular systems Mississippi State University Starkville MS 39759 USA Mechanical Engineering department Mississippi State University Starkville MS 39759 USA Materials Processing Group Oak Ridge National Laboratory Oak Ridge TN 37831 USA

A cellular automaton （CA）-finite element （FE） model and a phase field （PF）-FE model were used to simulate equiaxed dendritic growth during the solidification of hexagonal metals. In the CA-FE model, the conservation equations of mass and energy were solved in order to calculate the temperature field, solute concentration, and the dendritic growth morphology. CA-FE simulation results showed reasonable agreement with the previously reported experimental data on secondary dendrite arm spacing （sdAs） vs cooling rate. In the PF model, a PF variable was used to distinguish solid and liquid phases similar to the conventional PF models for solidification of pure materials. Another PF variable was considered to determine the evolution of solute concentration. Validation of both models was performed by comparing the simulation results with the analytical model developed by Lipton-Glicksman-Kurz （LGK）, showing quantitatively good agreement in the tip growth velocity at a given melt undercooling. Application to magnesium alloy AZ91 （approximated with the binary Mg-8.9 wt% AI） illustrates the difficulty of modeling dendrite growth in hexagonal systems using CA-FE regarding mesh-induced anisotropy and a better performance of PF-FE in modeling multiple arbitrarily-oriented dendrites growth.

关键词： dendrite growth Cellular automaton Phase-field model Finite element~ Magnesium alloy

Contribution of High sensible C-Reactive Protein (hsCRP) in the Assessment of the Risk of Onset of Type 2 diabetes and Its Cardiovascular Complications

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Journal of diabetes Mellitus 2024年第2期14卷 95-107页

作者： Maïmouna Touré Léopold Ngor sène Jean Pierre diagne demba diédhiou souleymane Thiam Abdou Khadir sow Mor diaw Aïssatou seck salimata diagne Houndjo Abdoulaye Ba Abdoulaye samb Fatou diallo-Agne Modou Oumy Kane Laboratoire de Physiologie et d’ Explorations Fonctionnelles Physiologiques Facult&#233 de M&#233decine de Pharmacie et d&#8217OdontoStomatologie (FMPOS) Universit&#233 Cheikh Anta Diop (UCAD) Dakar S&#233n&#233gal IRL3189 &#8220Environnement Sant&#233 Soci&#233t&#233&#8221 CNRS CNRST Bamako-UCAD Facult&#233 de M&#233decine de Pharmacie et d&#8217OdontoStomatologie (FMPOS) Universit&#233 Cheikh Anta Diop (UCAD) Dakar S&#233n&#233gal Laboratoire Privé de Biologie General Kaolack S&#233n&#233gal Centre Hospitalier Universitaire (CHU) Abasse Ndao Universit&#233 Cheikh Anta Diop (UCAD) Dakar S&#233n&#233gal Laboratoire de Biochimie et de Biologie molé culaire Facult&#233 de M&#233decine de Pharmacie et d&#8217OdontoStomatologie (FMPOS) Universit&#233 Cheikh Anta Diop (UCAD) Dakar S&#233n&#233gal Laboratoire de Physiologie Pharmaceutique Facult&#233 de M&#233decine de Pharmacie et d'OdontoStomatologie (FMPOS) Universit&#233 Cheikh Anta Diop (UCAD) Dakar S&#233n&#233gal

Background: Type 2 diabetes is a metabolic disease characterized by chronic hyperglycemia. The latter plays an essential role in inflammation by stimulating the production of pro-inflammatory cytokines or by increasing their secretion by an oxidative mechanism. These cytokines control the hepatic synthesis of an inflammatory protein called C-Reactive Protein (CRP). High or average values of CRP would have a predictive value of cardiovascular diseases and type 2 diabetes. The relationship between low CRP values and the risk of developing type 2 diabetes and its cardiovascular complications is not sufficiently studied. The hsCRP could serve as a predictive biomarker of risk of onset, follow-up and prognosis for type 2 diabetes and its cardiovascular complications. To answer this problem, we conducted this study, the aim of which was to study the predictive role of hsCRP in the risk of occurrence of type 2 diabetes and its cardiovascular complications. Materials and Methods: This is a prospective and cross-sectional case-control study involving 200 participants including 100 control women and 100 women with type 2 diabetes (mean age was respectively 49.89 years ± 8.26 & 51.92 years ± 7.18;p = 0.066). The interviews were conducted on the basis of a questionnaire. Physical examination collected biometric data and cardiovascular constants. The biochemical parameters such as hsCRP were analyzed by an automated Abbott device. Results: We noted that hsCRP was significantly higher in type 2 diabetic subjects compared to control subjects (p (rho = 0.40, p systolic blood pressure (rho = 0.30, p = 0.003), diastolic blood pressure (rho = 0.28, p = 0.006), total body fat (rho = 0.48, p Conclusion: hsCRP has a prognostic value in the evaluation of cardiovascular risk. It seems to play an important role in the pathogenesis of type 2 diabetes mellitus and its cardiovascular complications. It could thus be considered as a biomarker for the screening, monitoring and prognosis of type 2

关键词： hsCRP Biomarker Inflammation Type 2 diabetes

The Physical Models of Cyclone diplegs in Fluidized Beds

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Chinese Journal of Chemical Engineering 2001年第4期9卷 337-347页

作者： K.smolders d.Geldart J.Baeyens InstituteforEnvironmentalsciences UniversityofAntwerpUniversiteitsplein12610WilrijkBelgium departmentofChemicalEngineering UniversityofBradford7RichmondRoadlBradfordBD71DPUnitedKingdom departmentofChemicalEngineering KatholiekeUniversiteitLeuvendeCroyla~n463001HeverleeBelgium

In most industrial fluidization units, two- or three-stage cyclone systems are used to clean the product gases. To return the solids to the bed, these cyclones are fitted with diplegs. By pass of gas from the bed through the dipleg is partially overcome by the back pressure build-up in the dipleg and by adding a trickle valve at the bottom of the dipleg. diplegs of primary cyclones, operating at a high solid loading behave differently from diplegs of secondary and tertiary cyclones which operate at low solid loading. Both types have been investigated by pressure drop measurements, visual observation and by measurements of the air flow rate flowing up the riser. The primary dipleg was also studied using electrical capacitance tomography. The results are reported hereafter and will give a first indication towards the right design of the dipleg and the selection of the trickle valve. The influence of gas flow in the dipleg on the conversion in a catalytic fluidized bed reactor is found to be negligible.

关键词： cyclone dipleg fluidized bed physical model

Process parameter effects on microstructure and mechanical properties of tubes processed via friction assisted tube straining method

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Journal of Central south University 2021年第10期28卷 3008-3017页

作者： s.H.HOssEINI M.sEdIGHI school of Mechanical Engineering Iran University of Science and TechnologyTehran 16846-13114Iran

This paper investigates process parameter effects on microstructure and mechanical properties of the tubes processed via recently developed friction assisted tube straining(FATs)*** this purpose,design of experiment was used to arrange finite element analyses and experimental *** and experimental tests were executed by changing rotary speed,feed rate and die *** design results show that increasing feed rate and decreasing rotary speed enhance Zener-Hollomon(Z)parameter and decrease average grain size,while die angle has no considerable *** Z value reduces grain size and enhances flow stress of the processed samples,while the experiment with the highest Z value refines initial microstructure from 40 to 8μm and increases flow stress by 5 times.

关键词： friction assisted tube straining process parameter microstructure Taguchi method finite element simulation

Role of serotonin in development of esophageal and gastric fundal varices

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World Journal of Gastroenterology 2010年第48期16卷 6135-6138页

作者： Jelena s Rudi dorde M ulafi duko s Mirkovi Rada s Jei Miodrag N Krsti Clinic of Gastroenterology Clinical Center of SerbiaFaculty of MedicineUniversity of Belgrade Centre of Medical Biochemistry Clinical Center of SerbiaSchool of PharmacyUniversity of Belgrade

AIM:To determine the effect of free serotonin concentrations in plasma on development of esophageal and gastric fundal varices. METHOds:This prospective study included 33 patients with liver cirrhosis and 24 healthy controls. Ultrasonography and measurement of serotonin concentration in plasma were carried out in both groups of subjects. The upper fiber panendoscopy was performed only in patients with liver cirrhosis. REsULTs:The mean plasma free serotonin levels were much higher in liver cirrhosis patients than in healthy controls (219.0 ± 24.2 nmol/L vs 65.4 ± 18.7 nmol/L,P s no significant correlation be-tween serotonin concentration in plasma and the size of the esophageal varices according to spearman coefficient of correlation (rs =-0.217,P > 0.05). However,the correlation of plasma serotonin concentration and gastric fundal varices was highly significant (rs =-0.601,P sION:Free serotonin is significant in pathogenesis of portal hypertension especially in development of fundal varices,indicating the clinical value of serotonergic receptor blockers in these patients.

关键词： serotonin Portal hypertension Esophageal varices Fundal varices Platelets

deposition of Nano-scaled Coatings Using Inductively Coupled Plasma

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Journal of Rare Earths 2004年第z2期22卷 153-156页

作者： d H Jung B Park J J Lee school of Materials science and Engineering College of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea

Nano-scaled Ti-B-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-B-N coatings were prepared by using a TiB2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP and a bias voltage to the substrate the hardness of the Ti-B-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-B-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

关键词： nano-scaled coatings industively conpled plasma

Non-uniform,axisymmetric misfit strain:in thin films bonded on plate substrates/substrate systems:the relation between non-uniform film stresses and system curvatures

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Acta Mechanica sinica 2005年第4期21卷 362-370页

作者： Yonggang Huang d. Ngo A. J. Rosakis department of Mechanical and Industrial Engineering University of Illinois Urbana at Urbana-Champain 1206 West Green Street IL 61801 USA Graduate Aeronautical Laboratory California Institute of TechnologyPasadena CA 91125 USA

Current methodologies used for the inference of thin film stress through curvature measurements are strictly restricted to stress and curvature states which are assumed to remain uniform over the entire film/substrate system. By considering a circular thin film/substrate system subject to non-uniform, but axisymmetric misfit strain distributions in the thin film, we derived relations between the film stresses and the misfit strain, and between the plate system＇s curvatures and the misfit strain. These relations feature a “local” part which involves a direct dependence of the stress or curvature components on the misfit strain at the same point, and a “non-local” part which reflects the effect of misfit strain of other points on the location of scrutiny. Most notably, we also derived relations between the polar components of the film stress and those of system curvatures which allow for the experimental inference of such stresses from full-field curvature measurements in the presence of arbitrary radial non-uniformities. These relations also feature a “non-local” dependence on curvatures making a full-field measurement a necessity. Finally, it is shown that the interfacial shear tractions between the film and the substrate are proportional to the radial gradients of the first curvature invariant and can also be inferred experimentally.

关键词： Non-uniform misfit strain Non-uniform wafer curvatures ,stress-curvature relations Non-local effects ,Interfacial shears

deep mine cooling,a case for Northern Ontario:Part Ⅰ

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International Journal of Mining science and Technology 2016年第6期26卷 721-727页

作者： d. Millar K. Trapani A. Romero MIRARCO 935 Ramsey Lake Rd Sudbury P3E 2C6 Canada Laurentian University 935 Ramsey Lake Rd Sudbury P3E 2C6 Canada

Cooling energy needs, for mines in Northern Ontario, are mainly driven by the mining depth and its operation. Part I of this research focusses on the thermal energy loads in deep mines as a result of the virgin rock temperature, mining operations and climatic conditions. A breakdown of the various heat sources is outlined, for an underground mine producing 3500 tonnes per day of broken rock, taking into consideration the latent and sensible portions of that heat to properly assess the wet bulb global temperature. The resulting thermal loads indicate that cooling efforts would be needed both at surface and underground to maintain the temperature underground within the legal threshold. In winter the air might also have to be heated at surface and cooled underground, to ensure that icing does not occur in the inlet ventilation shaft-the main reason why coolin~ cannot be focussed solely at surface.

关键词： Thermal loads Cooling Underground mining deep mining HVAC mining

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A case of type Ⅰ variant Kounis syndrome with samter-Beer triad

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World Journal of Cardiology 2013年第4期5卷 112-114页

作者： Jayesh s Prajapati Kapil M Virpariya Ashok s Thakkar Atul d Abhyankar department of Cardiology UN Mehta Institute of Cardiology and Research CenterAhmedabad 380016GujaratIndia department of Clinical Trials Sahajanand Medical Technologies Pvt.Ltd.Surat 395004India department of Cardiology Shree BD Mehta Mahavir Heart InstituteAthwagateSurat 395001India

Kounis syndrome is defined as the coexistence of acute coronary syndromes with situations associated with allergy or hypersensitivity,as well as anaphylactic or anaphylactoid reactions,to a variety of medical conditions,environmental and medication *** report a case of Kounis-Zavras syndrome type Ⅰ variant in the setting of aspirin-induced asthma,or the samter-Beer triad of asthma,nasal polyps and aspirin *** there is a young individual with no predisposing factors of atherosclerosis and apparent coronary lesion,with or without electrocardiography and biochemical markers of infarction,the possibility of Kounis syndrome should be kept in mind.

关键词： Kounis syndrome samter-Beer triad Nasal polyps Coronary spasm Aspirin allergy