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Velocity profiles description and shape factors inclusion in a hyperbolic,one-dimensional,transient two-fluid model for stratified and slug flow simulations in pipes

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Petroleum 2019年第2期5卷 191-198页

作者： Arianna Bonzanini Davide picchi Marco Ferrari Pietro Poesio Dipartimento di Ingegneria Meccanica ed Industriale Universita degli Studi di BresciaVia Branze3825123BresciaItaly Energy Resources Engineering Stanford UniversityStanford94305CAUnited States Department of Mathematics Politecnico di Milanop.zza Leonardo da Vinci3220133MilanItaly

In a previous work it has been shown that a one-dimensional,hyperbolic,transient five equations twofluid model is able to numerically describe stratified,wavy,and slug flow in horizontal and nearhorizontal pipes.Slug statistical characteristics can be numerically predicted with results in good agreement with experimental data and well-known empirical relations.In this model some approximated and simplified assumptions are adopted to describe shear stresses at wall and at phase interface.In this paper,we focus on the possibility to account for the cross sectional flow by inserting shape factors into the momentum balance equations of the aforementioned model.Velocity profiles are obtained by a pre-integrated model and they are computed at each time step and at each computational cell.Once that the velocity profiles are known,the obtained shape factors are inserted in the numerical resolution.In this way it is possible to recover part of the information lost due to the one-dimensional flow description.Velocity profiles computed in stratified conditions are compared against experimental profiles measured by PIV technique;a method to compute the velocity profile during slug initiation and growth has been developed and the computed velocity distribution in the liquid phase was compared against the one-seventh power law.

关键词： Multi-phase pipeline transport Oil&gas Hyperbolic two-fluid model Velocity profiles Shape factors

幻肢和余剩幻肢研究的历史性回顾及新病例报告(英文)

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Neuroscience Bulletin 2011年第6期27卷 359-365页

作者： Gabriele Cipriani Lucia picchi Marcella Vedovello Angelo Nuti Mario Di Fiorino Versilia医院神经科 Via Aurelia55043Lido di Camaiore(Lu)意大利 Versilia医院精神科 Via Aurelia55043Lido di Camaiore(Lu)意大利

大脑通常决定人类对其周围环境的感受。幻肢是接受过截肢手术的人所产生的一种幻觉,他们总感觉失去的肢体仍存在于躯干上。揭开幻肢的成因已成为神经病学领域的一个研究热点。此外,一些病人中风后会感觉到除正常存在的双臂和双腿之外,... 详细信息

大脑通常决定人类对其周围环境的感受。幻肢是接受过截肢手术的人所产生的一种幻觉,他们总感觉失去的肢体仍存在于躯干上。揭开幻肢的成因已成为神经病学领域的一个研究热点。此外,一些病人中风后会感觉到除正常存在的双臂和双腿之外,还存在额外的肢体。这种复杂的、意识和知觉上的偏差称为余剩幻肢。本文主要就幻肢和余剩幻肢的病因及对其认识的历史性发展作一综述,并报告一例余剩幻肢患者。

关键词：幻肢余剩幻肢身体图式

Film cooling adiabatic effectiveness measurements of pressure side trailing edge cooling configurations

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Propulsion and Power Research 2015年第4期4卷 190-201页

作者： R.Becchi B.Facchini A.picchi L.Tarchi D.Coutandin S.Zecchi Department of Industrial Engineering University of FlorenceVia S.Marta 350139FirenzeItaly GE Avio S.r.l. Via I Maggio 9910040Rivalta di TorinoTorinoItaly

Nowadays total inlet temperature of gas turbine is far above the permissible metal temperature;as a consequence,advanced cooling techniques must be applied to protect from thermal stresses,oxidation and corrosion the components located in the high pressure stages,such as the blade trailing edge.A suitable design of the cooling system for the trailing edge has to cope with geometric constraints and aerodynamic demands;state-of-the-art of cooling concepts often use film cooling on blade pressure side:the air taken from last compressor stages is ejected through discrete holes or slots to provide a cold layer between hot mainstream and the blade surface.With the goal of ensuring a satisfactory lifetime of blades,the design of efficient trailing edge film cooling schemes and,moreover,the possibility to check carefully their behavior,are hence necessary to guarantee an appropriate metal temperature distribution.For this purpose an experimental survey was carried out to investigate the film covering performance of different pressure side trailing edge cooling systems for turbine blades.The experimental test section consists of a scaled-up trailing edge model installed in an open loop suction type test rig.Measurements of adiabatic effectiveness distributions were carried out on three trailing edge cooling system configurations.The baseline geometry is composed by inclined slots separated by elongated pedestals;the second geometry shares the same cutback configuration,with an additional row of circular film cooling holes located upstream;the third model is equipped with three rows of in-line film cooling holes.Experiments have been performed at nearly ambient conditions imposing several blowing ratio values and using carbon dioxide as coolant in order to reproduce a density ratio close to the engine conditions(DR¼1.52).To extend the validity of the survey a comparison between adiabatic effectiveness measurements and a prediction by correlative approach was performed to compare the experimental results with 1D methodologi

关键词： Turbine blades Trailing edge Film cooling Pressure sensitive paint(PSP)

Microwave ablation of hepatocellular carcinoma

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World Journal of Hepatology 2015年第25期7卷 2578-2589页

作者： Guido Poggi Nevio Tosoratti Benedetta Montagna Chiara picchi Oncology and Hepatology Unit Institute of Care Città di Pavia R and E Unit HS Hospital Service SpA

Although surgical resection is still the optimal treatment option for early-stage hepatocellular carcinoma(HCC) in patients with well compensated cirrhosis,thermal ablation techniques provide a valid nonsurgical treatment alternative,thanks to their minimal invasiveness,excellent tolerability and safety profile,proven efficacy in local disease control,virtually unlimited repeatability and cost-effectiveness.Different energy sources are currently employed in clinics as physical agents for percutaneous or intra-surgical thermal ablation of HCC nodules.Among them,radiofrequency(RF) currents are the most used,while microwave ablations(MWA) are becoming increasingly popular.Starting from the 90s',RF ablation(RFA) rapidly became the standard of care in ablation,especially in the treatment of small HCC nodules;however,RFA exhibits substantial performance limitations in the treatment of large lesions and/or tumors located near major heat sinks.MWA,first introduced in the Far Eastern clinical practice in the 80s',showing promising results but also severe limitations in the controllability of the emitted field and in the high amount of power employed for the ablation of large tumors,resulting in a poor coagulative performance and a relatively high complication rate,nowadays shows better results both in terms of treatment controllability and of overall coagulative performance,thanks to the improvement of technology.In this review we provide an extensive and detailed overview of the key physical and technical aspects of MWA and of the currently available systems,and we want to discuss the most relevant published data on MWA treatments of HCC nodules in regard to clinical results and to the type and rate of complications,both in absolute terms and in comparison with RFA.

关键词： Thermal ablation Hepatocellular carcinoma Microwave ablation Percutaneous microwave ablation Laparoscopic microwave ablation Complications

Coronary microvascular dysfunction in diabetes mellitus:A review

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World Journal of Cardiology 2010年第11期2卷 377-390页

作者： Andrea picchi Stefano Capobianco Marta Focardi Department of Cardiology Misericordia HospitalVia Senese 16158100 GrossetoItaly Department of Cardiology Gaetano Rummo HospitalVia Dell'Angelo 182100 BeneventoItaly

The exploration of coronary microcirculatory dysfunction in diabetes has accelerated in recent years.Cardiac function is compromised in diabetes.Diabetic patients manifest accelerated atherosclerosis in coronary arteries.These data are confirmed in diabetic animal mod-els,where lesions of small coronary arteries have been described.These concepts are epitomized in the classic microvascular complications of diabetes,i.***.blindness,kidney failure and distal dry gangrene.Most importantly,accumulating data indicate that insights gained from the link between inflammation and diabetes can yield predictive and prognostic information of considerable clinical utility.This review summarizes the evidence for the predisposing factors and the mechanisms involved in diabetes,and assesses the current state of knowledge regarding the triggers for inflammation in this disease.We evaluate the roles of hyperglycemia,oxidative stress,polyol pathway,protein kinase C,advanced glycation end products,insulin resistance,peroxisome proliferator-activated receptor-γ,inflammation,and diabetic cardiomyopathy as a "stem cell disease".Furthermore,we discuss the mechanisms responsible for impaired coronary arteriole function.Finally,we consider how new insights in diabetes may provide innovative therapeutic strategies.

关键词： Coronary artery Diabetes Endothelial dysfunction Hyperglycemia Inflammation Insulin Microcirculation Nitric oxide Oxidative stress

欧洲和中国的心脏与肾脏远程缺血预适应研究:一项随机对照试验

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中华高血压杂志 2018年第4期26卷 334-334页

作者：刘青叶鹏 Moretti C Cerrato E Cavallero E Lin S Rossi ML picchi a Sanguineti F Ugo F Palazzuoli A Bertaina M Presbitero P Shao-Liang C Pozzi R Giammaria M Limbruno U Lefèvre T Gasparetto V Garbo R OmedèP Sheiban I Escaned J Biondi-Zoccai G Gaita F Perl L D'Ascenzo F

远程缺血预适应（remote ischemic preconditioning,RIPC）对经皮冠状动脉介入治疗（percutaneous coronary intervention,PCI）术后造影剂肾病（contrast-induced nephropathy,CIN）的潜在保护作用尚待确定。该研究为双盲、随机、安慰剂对照的多中心研究,纳入年龄〈85岁,肾清除率为30～60mL/（min·1.73m^2）的有临床适应证的患者,除了直接PCI外均按1∶1给予RIPC或标准治疗。主要终点是CIN的发生率。次要终点是围手术期心肌梗死（peri-procedural myocardial infarction,PMI）的发生率。

关键词：随机对照试验缺血预适应远程经皮冠状动脉介入治疗肾脏心脏中国欧洲