scholarly journals Interpreting turbidity measurements for vesicle studies

2018 ◽  
Author(s):  
Anna Wang ◽  
Christopher Chan Miller ◽  
Jack W. Szostak
Keyword(s):  
Experimental Data ◽  
Exact Solution ◽  
Oleic Acid ◽  
Multiple Scattering ◽  
Excellent Agreement ◽  
Core Shell ◽  
Comprehensive Overview ◽  
Vesicle Size ◽  
Vesicle Membranes ◽  
Scatter Light

Spectrophotometers are routinely used to assess the turbidity of vesicle solutions. Here we provide guidelines for interpreting turbidity measurements of vesicle samples, and highlight potential pitfalls of the approach. We use an exact solution for core-shell scatterers to model and calculate how samples of vesicles scatter light, and provide a comprehensive overview of how the turbidity of vesicle samples can change with vesicle size, contents, and composition. Surprisingly, we find that vesicle lamellarity has a large effect on sample turbidity, while unilamellar vesicles of different sizes have similar turbidity. We use our model in conjunction with experimental data to measure the thickness of oleic acid vesicle membranes and find excellent agreement with values determined by cryo-TEM. We also calculate the effects of potential errors in measurement from forward scattering and multiple scattering.

Engineered Inorganic/Organic-Core/Shell Magnetic FexOy Nanoparticles with Oleic Acid and/or Oleylamine As Capping Agents

2015 ◽  
Vol 21 (37) ◽  
pp. 5369-5388 ◽  
Author(s):  
Richard Harris ◽  
Hendriëtte van der Walt ◽  
Poslet Shumbula
Keyword(s):  
Oleic Acid ◽  
Core Shell ◽  
Capping Agents

scholarly journals Experimental demonstration of negative refraction with 3D locally resonant acoustic metafluids

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benoit Tallon ◽  
Artem Kovalenko ◽  
Olivier Poncelet ◽  
Christophe Aristégui ◽  
Olivier Mondain-Monval ◽  
...  
Keyword(s):  
Experimental Data ◽  
Yield Stress ◽  
Multiple Scattering ◽  
Silicone Rubber ◽  
Acoustic Waves ◽  
Scattering Theory ◽  
Negative Refraction ◽  
Volume Fraction ◽  
Experimental Demonstration ◽  
Acoustic Beam

AbstractNegative refraction of acoustic waves is demonstrated through underwater experiments conducted at ultrasonic frequencies on a 3D locally resonant acoustic metafluid made of soft porous silicone-rubber micro-beads suspended in a yield-stress fluid. By measuring the refracted angle of the acoustic beam transmitted through this metafluid shaped as a prism, we determine the acoustic index to water according to Snell’s law. These experimental data are then compared with an excellent agreement to calculations performed in the framework of Multiple Scattering Theory showing that the emergence of negative refraction depends on the volume fraction $$\Phi$$ Φ of the resonant micro-beads. For diluted metafluid ($$\Phi =3\%$$ Φ = 3 % ), only positive refraction occurs whereas negative refraction is demonstrated over a broad frequency band with concentrated metafluid ($$\Phi =17\%$$ Φ = 17 % ).

Convective Losses From Cavity Solar Receivers—Comparisons Between Analytical Predictions and Experimental Results

1983 ◽  
Vol 105 (1) ◽  
pp. 29-33 ◽  
Author(s):  
A. M. Clausing
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Analytical Model ◽  
Excellent Agreement ◽  
Experimental Results ◽  
Simple Analytical Model ◽  
Refined Model ◽  
Wall Area

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent agreement is obtained, and the important mechanisms are more clearly delineated.

scholarly journals Exact Solution for Viscoelastic Flow in Pipe and Experimental Validation

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 334
Author(s):  
Ekaterina Vachagina ◽  
Nikolay Dushin ◽  
Elvira Kutuzova ◽  
Aidar Kadyirov
Keyword(s):  
Experimental Data ◽  
Exact Solution ◽  
Analytical Methods ◽  
Experimental Validation ◽  
Parametric Method ◽  
Fluid Flows ◽  
Parametric Representation ◽  
Viscoelastic Flow ◽  
Exponential Form ◽  
Image Velocimetry

The development of analytical methods for viscoelastic fluid flows is challenging. Currently, this problem has been solved for particular cases of multimode differential rheological equations of media state (Giesekus, the exponential form of Phan-Tien-Tanner, eXtended Pom-Pom). We propose a parametric method that yields solutions without additional assumptions. The method is based on the parametric representation of the unknown velocity functions and the stress tensor components as a function of coordinate. Experimental flow visualization based on the SIV (smoke image velocimetry) method was carried out to confirm the obtained results. Compared to the Giesekus model, the experimental data are best predicted by the eXtended Pom-Pom model.

scholarly journals A Quantitative Determination of Minimum Film Thickness in Elastohydrodynamic Circular Contacts

2021 ◽  
Author(s):  
Wassim Habchi ◽  
Philippe Vergne
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Model ◽  
Film Thickness ◽  
Quantitative Determination ◽  
Excellent Agreement ◽  
Operating Conditions ◽  
Pure Rolling ◽  
Minimum Film Thickness

Abstract The current work presents a quantitative approach for the prediction of minimum film thickness in elastohydrodynamic lubricated (EHL) circular contacts. In contrast to central film thickness, minimum film thickness can be hard to accurately measure, and it is usually poorly estimated by classical analytical film thickness formulae. For this, an advanced finite-element-based numerical model is used to quantify variations of the central-to-minimum film thickness ratio with operating conditions, under isothermal Newtonian pure-rolling conditions. An ensuing analytical expression is then derived and compared to classical film thickness formulae and to more recent similar expressions. The comparisons confirmed the inability of the former to predict the minimum film thickness, and the limitations of the latter, which tend to overestimate the ratio of central-to-minimum film thickness. The proposed approach is validated against numerical results as well as experimental data from the literature, revealing an excellent agreement with both. This framework can be used to predict minimum film thickness in circular elastohydrodynamic contacts from knowledge of central film thickness, which can be either accurately measured or rather well estimated using classical film thickness formulae.

Effect of glycidyl methacrylate (GMA) on the stability of acrylic latex

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Guangfeng Wu ◽  
Yue Tao ◽  
Hong Kang ◽  
Huixuan Zhang
Keyword(s):  
Experimental Data ◽  
Glycidyl Methacrylate ◽  
Sodium Dodecyl ◽  
The Other ◽  
Lower Amount ◽  
Core Shell ◽  
Acrylic Latex ◽  
The Core ◽  
Shell Particles ◽  
The Stability

AbstractThe stability of core-shell particles (CSPs) with butyl acrylate (BA) as the core and methyl methacrylate (MMA)/glycidyl methacrylate (GMA) mixture in various compositions as the shell was investigated by turbidity measurements. The experiments demonstrate that lower amount addition of GMA could not improve the latex stability. When the amount of GMA exceeded 2% of the total reactants, it began to improve the stability of the latex. With the increasing content of GMA, the latex became more and more stable. On the other hand, experimental data also show that the stability was improved by increasing the concentration of sodium dodecyl sulfate (SDS).

scholarly journals Modelling of the behaviour of metal foams under shock compression

2018 ◽  
Vol 183 ◽  
pp. 01041
Author(s):  
Nicolas Jacques ◽  
Romain Barthélémy
Keyword(s):  
Experimental Data ◽  
Excellent Agreement ◽  
Strain Curve ◽  
Metal Foams ◽  
Cellular Materials ◽  
Theoretical Modelling ◽  
Stress Strain Curve ◽  
Open Cell ◽  
Proposed Model ◽  
Shock Response

A theoretical modelling is proposed to describe the shock response of foam materials. This model is based on micromechanical and energetic arguments, and takes into account the contribution of microscale inertia. Within this framework, an analytical expression of the Hugoniot stress-strain curve is proposed for elastic-plastic cellular materials. The predictions derived from the proposed model are in excellent agreement with experimental data for open-cell aluminium foams. The case of viscoplastic foams is also considered.

New model of dielectric strength of Debye relaxation in monohydroxy alcohols

2019 ◽  
Vol 33 (26) ◽  
pp. 1950313
Author(s):  
Li-Na Wang ◽  
Xing-Yu Zhao ◽  
Yi-Neng Huang
Keyword(s):  
Experimental Data ◽  
Exact Solution ◽  
High Temperature ◽  
Ising Model ◽  
Dielectric Spectroscopy ◽  
Dielectric Strength ◽  
Experimental Results ◽  
Debye Relaxation ◽  
New Model ◽  
Model Predictions

The Debye relaxation of dielectric spectroscopy exists extensively in monohydroxy alcohols, and the existing theory of the dielectric strength is obviously inconsistent with the experimental results. In this paper, we propose an Ising model of infinite free-rotating pseudospin chains and get the exact solution of the dielectric strength versus temperature. The model predictions are qualitatively consistent with the experimental results, especially the crossover from the low to the high-temperature Curie–Weiss law. The quantitative comparisons indicate that the model predictions can agree well with the experimental data below 250 K.

scholarly journals Über die Konformation yon 1.2.4.5-Tetrathian / On the Conformation of 1,2,4,5-Tetrathiane

1982 ◽  
Vol 37 (2) ◽  
pp. 234-235 ◽  
Author(s):  
Rudy Susilo ◽  
Rolf Gmelin
Keyword(s):  
Experimental Data ◽  
Nmr Spectroscopy ◽  
Force Field ◽  
Excellent Agreement ◽  
Dynamic Nmr ◽  
Force Field Calculations ◽  
Chair Form ◽  
Dynamic Nmr Spectroscopy ◽  
Twist Form

Abstract The conformation of 1,2,4,5-tetrathian was determined by means of dynamic NMR spectroscopy. The barrier (ilG+) of the chair/twist equilibration is 14.5 kcal/mol and the chair form is more stable than the twist form in this molecule by 1.4 kcal/mol. These experimental data are in excellent agreement with force field calculations

Diffuse Reflectance of Highly Anisotropic Nonconservative Media

1976 ◽  
Vol 30 (6) ◽  
pp. 610-614 ◽  
Author(s):  
Harry G. Hecht
Keyword(s):  
Exact Solution ◽  
Exact Solutions ◽  
Excellent Agreement ◽  
Phase Function ◽  
Entire Range ◽  
Approximate Formula ◽  
Diffuse Reflectance ◽  
Incident Radiation ◽  
Scattering Media ◽  
Reflectance Data

With the use of methods described by Chandrasekhar, integrals have been tabulated which allow the diffuse reflectance of highly anisotropic nonconservative scattering media to be calculated. Solutions obtained in this way are compared for normally incident radiation with those given by an approximate formula due to Pitts. It is found that the Pitts formula is in excellent agreement with the exact solution and can be used to interpret reflectance data throughout the entire range of positive x values for which exact solutions exist for the phase function ω0 (1 + x cos θ).

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