Some further observations on the creeping motion of spheres through Ellis model fluids

Using the formulation of Hopke and Slattery, upper and lower bounds on the drag coefficient of a sphere moving slowly in Ellis model fluids have been calculated, over wide range of conditions, and compared with the suitable experimental data available in the literature. C _D drag coefficient - d diameter of sphere - El Ellis number - Re Reynolds number based on zero-shear viscosity - V terminal falling velocity of a sphere - X drag correction factor - Ellis model parameter - ₀ zero-shear viscosity - _1/2 Ellis model parameter     

Establishment of an integrated data fusion method between the colorimeter and near-infrared spectroscopy to discriminate the stir-baked Gardenia jasminoides Ellis

Stir-heating is a common method to process Gardenia jasminoides Ellis. The processing of the G. jasminoides Ellis which do not meet the regulated requirements can result in the unqualified products, finally decreasing the efficacy of the drug. To guarantee the quality of the stir-baked G. jasminoides Ellis, a rapid and efficient method to discriminate the qualified stir-baked G. jasminoides Ellis from the unqualified was developed based on the middle level data fusion. 61 batches of qualified and unqualified stir-baked G. jasminoides Ellis were collected and analyzed using colorimeter and near-infrared spectroscopy, separately. L*, A*, and B* were apparent features that quantitatively described the characteristics of samples. The latent variables of partial least squares discriminant analysis model were extracted as the features of near-infrared spectroscopy. The extracted features from colorimeter and near-infrared spectroscopy were fused and a discriminant model was built using partial least squares discriminant analysis method. Accuracy, sensitivity, and specificity were used to evaluate the ability of classification. As a result, the accuracy, sensitivity, and specificity of the optimal partial least squares discriminant analysis model based on fused data were all equal to 1. It demonstrated that the developed method can be capable of discriminating the qualified stir-baked G. jasminoides Ellis from the unqualified. Compared with classification model results using color parameters or near infrared data alone, this data fusion strategy greatly improved the accuracy of classification.     

Approximate solutions for drag coefficient of bubbles moving in shear-thinning elastic fluids

The drag coefficient for bubbles with mobile or immobile interface rising in shear-thinning elastic fluids described by an Ellis or a Carreau model is discussed. Approximate solutions based on linearization of the equations of motion are presented for the highly elastic region of flow. These solutions are in reasonably good agreement with the theoretical predictions based on variational principles and with published experimental data. C _D Drag coefficient - E ^* Differential operator [E ^{* 2} = ²/² + (sin/ ²)/(1/sin /)] - El Ellis number - F _D Drag force - K Consistency index in the power-law model for non-Newtonian fluid - n Flow behaviour index in the Carreau and power-law models - P Dimensionless pressure [=(p – p ₀)/₀ (U /R)] - p Pressure - R Bubble radius - Re ₀ Reynolds number [= 2R U /₀] - Re Reynolds number defined for the power-law fluid [= (2R) ⁿ U ^2–n /K] - r Spherical coordinate - t Time - U Terminal velocity of a bubble - u Velocity - Wi Weissenberg number - Ellis model parameter - Rate of deformation - Apparent viscosity - ₀ Zero shear rate viscosity - Infinite shear rate viscosity - Spherical coordinate - Parameter in the Carreau model - ^* Dimensionless time [=/(U /R)] - Dimensionless length [=r/R] - Second invariant of rate of deformation tensors - ^* Dimensionless second invariant of rate of deformation tensors [=/(U /R)²] - Second invariant of stress tensors - ^* Dimensionless second invariant of second invariant of stress tensor [= / ₀ ² (U /R)²] - Fluid density - Shear stress - ^* Dimensionless shear stress [=/ ₀ (U /R)] - _1/2 Ellis model parameter - ₁ ^2/* Dimensionless Ellis model parameter [= _1/2/ ₀(U /R)] - Stream function - ^* Dimensionless stream function [=/U R ²]     

Total synthesis,reactivity, and structural clarification of lindenatriene

The synthesis of lindenatriene (1) and iso-lindenatriene (12) were achieved, along with the des-hydroxy model compounds (10 and 18, respectively), and compared to reported ¹H NMR spectra in the literature (1a and 10a). These comparisons clarify the correct initial assignment of lindenatriene (1) as well as its instability and propensity to isomerize into the more thermodynamically favored iso-lindenatriene (12).     

Measurement and the verificationist theory/observation distinction

In the following article, we propose to show that following the general verificationist epistemic programme (its demand that the truth of our judgments be verifiable), the analysis of measurement on the one hand, and the classical positivist analysis of common-sense observation on the other, do not lead to same conclusions. This is especially important, because the differences in conclusions concern the positivist theory/observation distinction. In particular, the analysis of measurement does not fully support this distinction. This fact might have important consequences for the problem of scientific realism and related ontological and epistemological problems in the philosophy of science.     

A model for film-forming with Newtonian and shear-thinning fluids

The formation of a thin film by (i) the slow penetration of a gas bubble into a liquid filled tube, (ii) the withdrawal of a planar substrate from a liquid filled gap, is investigated theoretically for the cases of both Newtonian and shear-thinning liquids; the latter conforming to either a power–law or Ellis model. Formulated as a boundary value problem underpinned by lubrication theory, the analysis gives rise to a system of ordinary differential equations which are solved numerically subject to appropriate boundary conditions. For Newtonian liquids comparison of the predicted residual film thickness for a wide range of capillary number, Ca  (10⁻⁴, 10), is made with others obtained using existing expressions, including the classical one of Bretherton, in the region of parameter space over which they apply. In the case of (i), prediction of the behaviour of the residual fluid fraction and gap-to-film thickness ratio, for a Newtonian liquid and one that is shear-thinning and modelled via a power–law, is found to be in particularly good agreement with experimental data for Ca < 0.2. For (ii), both shear-thinning models are utilized and contour plots of residual film thickness generated as a function of Ca and the defining parameters characteristic of each model.     

Isolation and purification of six iridoid glycosides from gardenia jasminoides fruit by medium‐pressure liquid chromatography combined with macroporous resin chromatography

Gardeniae fructus is one of the most frequently used herbs in traditional Chinese medicine. In the present study, a process for the enrichment of six iridoid glycosides from Gardeniae fructus was developed using medium‐pressure liquid chromatography combined with macroporous resin and reversed‐phase chromatography. The purities of different fractions from Gardeniae fructus were assessed using quantitative high‐performance liquid chromatography. After fractionation using HPD‐100 column chromatography, a 30% ethanol fraction was selected based on high‐performance liquid chromatography and liquid chromatography with mass spectrometry qualitative analysis to separate and purify. Based on the orientation analysis results, six compounds—deacetyl asperulosidic acid methyl ester, gardenoside, ixoroside, scandoside methyl ester, genipin‐1‐O‐β‐d‐ gentiobioside, and geniposide—were successfully isolated and purified in three to four combined steps from Gardeniae fructus. The purities of these compounds were found by high‐performance liquid chromatography analysis to be 97.9, 98.1, 95.5, 96.3, 97.1, and 98.7%, respectively. Moreover, their structures were elucidated by NMR spectroscopy and liquid chromatography with tandem mass spectrometry. The separation process was highly efficient, rapid, and accurate, making it a potential approach for the large‐scale production of iridoids in the laboratory and providing several marker compounds for quality control. This procedure may be meaningful for the purification of other natural products used in traditional Chinese medicine.     

Early Attempts to Detect the Neutrino at the Cavendish Laboratory

In the 1920s and early 1930s the Cavendish Laboratory in Cambridge was preeminent in experimental research on radioactivity and nuclear physics, with theoretical physics playing a subsidiary role in guiding, but not determining the course of experimental research. Soon after Wolfgang Pauli (1900–1958) proposed his neutrino hypothesis in 1930 to preserve conservation of energy and momentum in beta decay, experiments – the first of their kind – were carried out in the Cavendish Laboratory to detect Pauli’s elusive particle, but they were abandoned in 1936. I trace these early attempts and suggest reasons for their abandonment, which may contribute to an understanding of the complex way in which theoretical entities are accepted by physicists.