The Experts below are selected from a list of 32019 Experts worldwide ranked by ideXlab platform
Elie Mousseaux - One of the best experts on this subject based on the ideXlab platform.
-
comparison of various methods for the estimation for aortic characteristic impedance in time domain from velocity encoded magnetic resonance and applanation tonometry data
Artery Research, 2013Co-Authors: Emilie Bollache, Nadjia Kachenoura, Ioannis Bargiotas, A De Cesare, M Bensalah, Alban Redheuil, Elie MousseauxAbstract:Objectives. Tocombinecardiovascularmagneticresonance(CMR),whichprovidesaccurateandnon-invasiveevaluationofflow,withapplanationtonometry toassessaortic characteristic impedance (Zc) in time domain while comparing six different methods. Methods. We studied 72 healthy volunteers (31women, age: 42.1 15.3years) who underwent aortic velocity-encoded CMR and carotid applanation tonometry. We developed a method for the superimposition of flow and Pressure waveforms as well as semi-automated estimation of temporal Zc based either on magnitude, derivative peaks and early systolic up-slopes ratios or Pressure-flow loop. All Zc indices were used to calculate reflection magnitude (RM) as the ratio between backward and forward Pressures. Results. For all methods, Zc was in good agreement with the reference Zc provided in frequency domain and with the theoretical water-hammer Zc, which combines aortic pulse wave velocity and area, and with carotid pulse Pressure (Table) with a slight superiority for methods based on derivatives peaks and early systolic up-slopes. In addition, only these latter two methods were significantly related to arterial stiffness indices such as tonometric carotid-femoral pulse wave velocity (rZ 0.27 and rZ 0.25; p < 0.03) and CMR ascending aorta distensibility (r Z 0.30 and r Z 0.25; p < 0.03). Again these two methods were slightly superior when comparing the derived RM against age (r Z 0.68, r Z 0.65; p < 0.0001). Conclusions. The time derivative and up-slopes straightforward computation methods that can be easily integrated in a clinical workflow provides
John H. Lienhard - One of the best experts on this subject based on the ideXlab platform.
-
Saturation and MetasTable Properties of the van der Waals Fluid
2015Co-Authors: N. Shamsundar, John H. LienhardAbstract:Modem applications require accurate thermodynamic equations of state that portray sTable and metasTable states of fluids. Earlier work has shown that the famous van der Waals equation, contrary to widely held views, finds its natural niche in the rank of real substances ordered according to their values of the acentric factor. In this note, the saturated and metasTable state properties of a van der Waals fluid are presented in the form 'of a temperature Table and a Pressure Table, A comparison of these results with the available data for mercury is made and it is established that mercury is approximated rather well as a van der Waals fluid, Les applications modemes exigent l'emploi d'equations d'etat thermodynamiques exactes decnvant les etats sTable et metasTable des fluides. Un travail anterieur a montre que la fameuse equation de van der Waals, contrairemenl a certains points de vue exprimes, trouve une place nature lie dans la classe des substances reelles ordonnees selon leurs valeurs du facteur "d'acentricite", On presente les propnetes aI'etat salure et metasTable d ' un flu ide de van der Waals, sous forme d'un Tableau de temperature et d'un Tableau de pression, On a compare ces resultats avec les donnees disponibles pour Ie mercure et l'on a etabli que Ie mercure est assez bien represente par un fluide de van der Waals, There has been strong recent interest in the formulation (T = 0,7)] ' (w =-0.302 for a van der Waals fluid, or of equations of state, driven in part by the problems of 0.058 for a Redlich-Kwong fluid,) dealing with the superheated liquids and supercooled vapors Peck's conclusion (which we endorse) is, in effect, that if that arise in many modem heat transfer processes, Such a real substance with Zc = 3 / 8 or w =-0.302 were to b
Emilie Bollache - One of the best experts on this subject based on the ideXlab platform.
-
comparison of various methods for the estimation for aortic characteristic impedance in time domain from velocity encoded magnetic resonance and applanation tonometry data
Artery Research, 2013Co-Authors: Emilie Bollache, Nadjia Kachenoura, Ioannis Bargiotas, A De Cesare, M Bensalah, Alban Redheuil, Elie MousseauxAbstract:Objectives. Tocombinecardiovascularmagneticresonance(CMR),whichprovidesaccurateandnon-invasiveevaluationofflow,withapplanationtonometry toassessaortic characteristic impedance (Zc) in time domain while comparing six different methods. Methods. We studied 72 healthy volunteers (31women, age: 42.1 15.3years) who underwent aortic velocity-encoded CMR and carotid applanation tonometry. We developed a method for the superimposition of flow and Pressure waveforms as well as semi-automated estimation of temporal Zc based either on magnitude, derivative peaks and early systolic up-slopes ratios or Pressure-flow loop. All Zc indices were used to calculate reflection magnitude (RM) as the ratio between backward and forward Pressures. Results. For all methods, Zc was in good agreement with the reference Zc provided in frequency domain and with the theoretical water-hammer Zc, which combines aortic pulse wave velocity and area, and with carotid pulse Pressure (Table) with a slight superiority for methods based on derivatives peaks and early systolic up-slopes. In addition, only these latter two methods were significantly related to arterial stiffness indices such as tonometric carotid-femoral pulse wave velocity (rZ 0.27 and rZ 0.25; p < 0.03) and CMR ascending aorta distensibility (r Z 0.30 and r Z 0.25; p < 0.03). Again these two methods were slightly superior when comparing the derived RM against age (r Z 0.68, r Z 0.65; p < 0.0001). Conclusions. The time derivative and up-slopes straightforward computation methods that can be easily integrated in a clinical workflow provides
N. Shamsundar - One of the best experts on this subject based on the ideXlab platform.
-
Saturation and MetasTable Properties of the van der Waals Fluid
2015Co-Authors: N. Shamsundar, John H. LienhardAbstract:Modem applications require accurate thermodynamic equations of state that portray sTable and metasTable states of fluids. Earlier work has shown that the famous van der Waals equation, contrary to widely held views, finds its natural niche in the rank of real substances ordered according to their values of the acentric factor. In this note, the saturated and metasTable state properties of a van der Waals fluid are presented in the form 'of a temperature Table and a Pressure Table, A comparison of these results with the available data for mercury is made and it is established that mercury is approximated rather well as a van der Waals fluid, Les applications modemes exigent l'emploi d'equations d'etat thermodynamiques exactes decnvant les etats sTable et metasTable des fluides. Un travail anterieur a montre que la fameuse equation de van der Waals, contrairemenl a certains points de vue exprimes, trouve une place nature lie dans la classe des substances reelles ordonnees selon leurs valeurs du facteur "d'acentricite", On presente les propnetes aI'etat salure et metasTable d ' un flu ide de van der Waals, sous forme d'un Tableau de temperature et d'un Tableau de pression, On a compare ces resultats avec les donnees disponibles pour Ie mercure et l'on a etabli que Ie mercure est assez bien represente par un fluide de van der Waals, There has been strong recent interest in the formulation (T = 0,7)] ' (w =-0.302 for a van der Waals fluid, or of equations of state, driven in part by the problems of 0.058 for a Redlich-Kwong fluid,) dealing with the superheated liquids and supercooled vapors Peck's conclusion (which we endorse) is, in effect, that if that arise in many modem heat transfer processes, Such a real substance with Zc = 3 / 8 or w =-0.302 were to b
Franzén Louise - One of the best experts on this subject based on the ideXlab platform.
-
Painted and gilded pennant of silk. A case study focusing on practical method development
2018Co-Authors: Franzén LouiseAbstract:The aim of this study is to design and establish effective methods of conserving a part of a pennant from the early 1700s. The pennant is made out of a single sheet of silk, which is decorated on both sides with a mirror image of a double-headed eagle. The pennant was deformed, brittle and had several tears and holes in it. A literature review was conducted to find out how similar objects had been conserved in the past and the present. It was also used for collecting information about the objects cultural context and its materials. The pennant was examined with a light microscope and X-ray fluorescence analysis. Several tests were done to determine the best way to conserve the pennant. They included conservation materials, investigative cleaning and flattening of the object, as well as ways to implement. The object was flattened by use of a humidity chamber and a low-Pressure Table. Superficial cleaning was done with a makeup sponge and bound saliva. It was shown that Lascaux 303 HV in a 15% water solution, impregnated to a support layer out of silk crepeline was the most proper stabilizing treatment for this object. The support material was attached to one side of the pennant by supplying heat to reactivate the adhesive. The edges of the silk crepeline were sealed with melted polyester thread and then finished with a stitched fold. Exposed adhesive was covered by adding impregnated silk crepeline to the sticky side. It was concluded that the treatment methods applied in this study was overall successful but some adjustments regarding the way to apply the adhesive on to the support material should be considered.Uppsats för avläggande av filosofie kandidatexamen i Kulturvård, Konservatorprogrammet 15 hp Institutionen för kulturvård Göteborgs universitet 2018:1