Mixing and Segregation Processes in Turbula Blender

2000 ◽  
Vol 627 ◽  
Author(s):  
Nathalie Sommier ◽  
Patrice Porion ◽  
Pierre Evesque
Keyword(s):  
Rotation Speed ◽  
Mixing Time ◽  
Qualitative And Quantitative Analysis ◽  
Resonance Imaging ◽  
Mixing Processes ◽  
Segregation Index ◽  
Qualitative And Quantitative ◽  
Magnetic Resonance Imaging Mri ◽  
Different Diameters ◽  
Kinetics Of

ABSTRACTMagnetic Resonance Imaging (MRI) technique was used to study the mixing and segregation processes of granular materials in a sophisticated tumbling blender (Turbula® mixer) using binary mixtures of sugar beads of different diameters d. Its motion generates mixtures with complex patterns. Effects of some parameters (beads diameter ratio, rotation speed, mixing time) were checked on segregation and mixing processes. We report in this paper, a qualitative and quantitative analysis of these phenomena. A segregation index S was defined to study the homogeneity and the kinetics of the mixing/segregation processes. When the ratio of bead diameters dmax/dmin is approximately 1, mixing process is observed but segregation occurs as soon as dmax/dmin is greater than 1.1.

An Infrared Spectrometric Study of the Oxidation of Natural Rubber

1952 ◽  
Vol 25 (2) ◽  
pp. 251-257
Author(s):  
L. D'Or ◽  
I. Kössler
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Infrared Absorption ◽  
Atmospheric Oxygen ◽  
Absorption Spectrometry ◽  
Oxidation Products ◽  
Qualitative And Quantitative Analysis ◽  
Qualitative And Quantitative ◽  
Kinetics Of ◽  
Infrared Absorption Spectrometry

Abstract The kinetics of the oxidation of natural rubber by atmospheric oxygen has been studied by various methods, for example, by volumetric and manometric measurements of the absorption of oxygen, by measurements of the increase of weight of the rubber, and by changes in the mechanical properties as a function of time. However, the oxidation of rubber is a complex phenomenon, and none of these techniques offers a means of following the oxidation in detail. In principle, it is possible, by infrared absorption spectrometry, to detect the presence of different groups which are present in a given sample of rubber and to determine their concentrations. Hence, it was hoped that this technique would offer a means of studying the various phenomena involved in the oxidation of rubber. In fact, this technique has already been employed in studies of the structure of rubber as well as in the qualitative and quantitative analysis of synthetic products. In addition to these already published studies, various authors have reported that the oxidation of natural rubber results in changes in its infrared spectrum, but none of the investigators has followed these changes quantitatively. Nevertheless, the possible interest of such a quantitative study, when carried out in parallel with a study of the changes in mechanical properties, has been pointed out by different authors. The authors of the present work decided, as a first approach to the problem, to prepare samples of rubber which could be studied by infrared absorption. The progress of oxidation could then be followed quantitatively by the disappearance of the principal groups present in rubber which had not undergone oxidation and the formation of characteristic groups in the oxidation products. Finally, from the data obtained, it was hoped, if not to draw conclusions as to the mechanism or mechanisms of oxidation, at least to obtain some indications of the precise kinetics of this oxidation.

Qualitative and quantitative diagnosis of intramuscular hemangioma subtypes: Diagnostic performance comparison of ESWAN and conventional MRI

2021 ◽  
pp. 028418512110651
Author(s):  
Jun Du ◽  
Kun Li ◽  
Wei Wang ◽  
Felix Young Jhonatan ◽  
Weisheng Zhang ◽  
...  
Keyword(s):  
Capillary Hemangioma ◽  
Performance Comparison ◽  
Resonance Imaging ◽  
Quantitative Diagnosis ◽  
Qualitative And Quantitative ◽  
Conventional Mri ◽  
Significant Difference ◽  
Cavernous Hemangiomas ◽  
Intramuscular Hemangioma ◽  
Magnetic Resonance Imaging Mri

Background Preoperative identification of intramuscular hemangioma (IMH) subtypes (capillary hemangioma, cavernous hemangioma, and mixed hemangioma) is urgently necessary. Enhanced T2*-weighted angiography (ESWAN) is sensitive to vessels and metabolites and can be used to diagnose IMH subtypes. Purpose To compare the diagnostic performances of ESWAN and conventional magnetic resonance imaging (MRI) for qualitative and quantitative diagnosis of IMH subtypes. Material and Methods In total, 23 patients with IMHs were examined using conventional MRI and ESWAN. The signal intensity ratios (SIRs) of conventional MRI and ESWAN were measured. Results There was no significant difference for volume among the three subtypes ( P = 0.124, P = 0.145). Various shapes and MRI signals were shown in the three subtypes of IMH. There was no significant difference for SIRs of conventional MRI ( P = 0.558, P = 0.259, P = 0.385, P = 0.347). However, there was a significant difference for SIRs of ESWAN parameters ( P = 0.050, P < 0.001, P = 0.005, P = 0.002). Capillary hemangiomas can be diagnosed when R2* SIR is <0.912 and intratumoral susceptibility signal (ITSS) percentage is <29.085%. Cavernous hemangiomas should be considered when R2* SIR is >0.912, ITSS percentage >35.226%, and phase SIR >2.536. In addition, mixed hemangiomas should be considered when T2* SIR is >0.662 and R2* SIR <1.618. Conclusion Conventional MRI can only display the volume, shape, and signal of IMHs. 3D-MinIP imaging of ESWAN can show the veins and minor hemorrhage. SIRs of ESWAN parameters including T2* value, R2* value, phase value, and percentage of ITSS can be used to quantitatively diagnose capillary hemangiomas, cavernous hemangiomas, and mixed hemangiomas.

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