Packaging of yield stress fluids: Flow patterns

The packaging or filling of a container with a non‐Newtonian fluid without quality failures is a current issue encountered at the final step of industrial product processes. In this work, the container filling of viscoplastic fluids is studied using an experimental laboratory plant able to reproduce the industrial transitory packaging conditions. First, a Newtonian validation was conducted to compare and to confirm our setup results with available literature data. Second five flow patterns including dripping, jet buckling, mounding, planar filling, and air entrainment were observed and characterized for the viscoplastic container filling. Most of them present different types of instabilities during the filling, except the planar filling, which seems to be ideal according to industrial specifications. A flow pattern distribution depending on relevant dimensionless numbers was developed. Finally, flow pattern transition criteria are determined highlighting the influence of rheological and process parameters on container filling. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1117–1126, 2018     

An Anisotropic A Contrario Framework for the Detection of Convergences in Images

The a contrario framework for the detection of convergences in an image consists in counting, for each tested point, the number of elementary linear structures that converge to it (up to a given precision), and when this number is high enough, the point is declared to be a meaningful point of convergence. This is so far analogous to a Hough transform, and the main contribution of the a contrario framework is to provide a statistical definition of what “high enough” means: it means large enough to ensure that in an image where all elementary structures are distributed according to a background noise model, there is, in expectation, less than 1 detection. Our aim in this paper is to discuss, from a methodological viewpoint, the choice and the influence of the background noise model. This model is generally taken as the uniform independent distribution on elementary linear structures, and here, we discuss the case of images that have a natural anisotropic distribution of structures. Our motivating example is the one of mammograms in which we would like to detect stellate patterns (that appear as local convergences of spicules), and in which the linear structures are naturally oriented towards the nipple. In this paper, we show how to tackle the two problems of (a) defining and estimating an anisotropic “normal” distribution from an image, and of (b) computing the probability that a random structure, following an anisotropic distribution, converges to any given convex region. We illustrate the whole approach with several examples.     

Properties of beeswax antifungal coatings obtained by high-pressure homogenisation and their application for preserving bananas during storage

Bananas are tropical fruits that are perishable and susceptible to fungal diseases, mainly caused by Colletotrichum musae. Antimicrobial emulsion-based coating materials have been used extensively to inhibit the growth of these fungi and extend the shelf life of bananas. Targeted emulsion-based film functionalities offer excellent mechanical, physicochemical and barrier properties and limit fungal growth kinetics. Antifungal compounds, such as essential oils or phenolic compounds, are added to emulsion-based (wax/biopolymer) coatings to enhance their antimicrobial properties. This study set out to formulate a beeswax-based emulsion for banana coatings using high-pressure homogenisation (HPH) and hydrophilic food-grade/organic coating materials. The particle size distribution, stability and mechanical properties of the film-forming emulsions, water vapour and the oxygen permeabilities of the resulting coating were investigated. The most promising sucrose emulsions were tested as coatings on banana fruits to assess their efficacy against moisture and firmness loss during storage. Adding thymol (0.5% w/w) to the sucrose emulsions further enhanced the inhibition of Colletotrichum musae growth to its barest minimum of <20%. Emulsion stability was clearly enhanced using HPH while the best inhibition was obtained with a 20% diluted sucrose emulsion containing 0.5% thymol, with or without HPH.     

Clinical utility of the Cross-Cultural (Chinese) Personality Assessment Inventory (CPAI-2) in the assessment of substance use disorders among Chinese men.

This study examined the clinical utility of the Cross-Cultural (Chinese) Personality Inventory (CPAI-2) in differentiating the personality characteristics of Chinese men with substance use disorders from other psychiatric patients and normal control participants. The CPAI-2 profile of 121 Chinese men with substance use disorders was contrasted with that of a matched psychiatric comparison group (n = 172) and a normal comparison group (n = 187). Multivariate analyses of variance and logistic regression results supported the utility of the CPAI-2 clinical scales, especially Pathological Dependence, Antisocial Behavior, and Depression, for assessing substance use disorders. The Pathological Dependence scale (cutoff T score of 64) achieved good sensitivity and specificity. Apart from the universal personality traits related to neuroticism, conscientiousness, and agreeableness found in Western studies, the indigenously derived CPAI-2 personality scales, including Family Orientation and Harmony, highlighted deficits in social adjustment and interpersonal relationship as important cultural features in the personality characteristics of these participants. The study provided a cross-cultural extension to research on the relationship between personality and substance use disorders and could assist clinicians in considering culturally relevant treatment approaches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biologically Active Tissue Factor-Bearing Larger Ectosome-Like Extracellular Vesicles in Malignant Effusions from Ovarian Cancer Patients: Correlation with Incidence of Thrombosis

The development of malignant effusions such as ascites reflects a massive progression of a malignant disease. In patients with ovarian carcinoma, a high amount of ascites (>500 mL) is an independent negative prognostic marker. The composition and constituents of ascites reflect the inflammatory environment of the underlying tumor. Increased cellular resistance of ascites-derived tumor cells and the development of venous thromboembolic events (VTE) are major risks for these patients, especially in patients with advanced ovarian carcinoma. In this study, we discuss the release of tissue factor-bearing extracellular vesicles (TF⁺ EVs) from tumor cells into the environment (ascites fluid) and their systemic spreading as a possible causal explanation of the pathologic coagulation status in these patients. We obtained ascites from patients with advanced ovarian carcinoma, collected during surgery or therapeutic paracentesis (n = 20). Larger ectosome-like EVs were isolated using sequential centrifugation, quantified by high-resolution flow cytometry and analyzed using nanoparticle tracking analysis. Furthermore, the pro-coagulant properties (TF activity) of EVs were determined. Compared to published TF activities of EVs from healthy persons, TF activities of EVs derived from ascites of patients with ovarian cancer were very high, with a median of 80 pg/mL. The rate of VTE, as reported in the patient files, was high as well (35%, 7 out of 20). Furthermore, all but one patient with VTE had EV concentrations above the median within their ascetic fluid (p < 0.02). Since VTE continues to be a frequent cause of death in cancer patients, prophylactic antithrombotic treatment might be worth considering in these patients. However, given the risk of bleeding, more clinical data are warranted. Although the study is too small to enable reaching a conclusion on direct clinical implementation, it can well serve as a proof of principle and a rationale to initiate a prospective clinical study with different patient subgroups. We also show ex vivo that these larger ectosome-like EVs induce intracellular ERK phosphorylation and tumor cell migration, which is not directly related to their pro-coagulative potency, but might help to understand why cancer patients with thromboembolic events have a poorer prognosis.     

Increasing the activity of Fe/N/C catalysts in PEM fuel cell cathodes using carbon blacks with a high-disordered carbon content

Fe/N/C catalysts for the reduction of oxygen in PEM fuel cells were prepared by pyrolyzing three series of iron acetate-impregnated developmental carbon blacks at 950 °C. The carbon supports used were derived from the N234, N330, and N650 commercial furnace grades. In this study, we tried to increase the performance of Fe/N/C-based cathode of PEM fuel cells by using the following two approaches: (1) increasing the number of catalytic sites on the carbon black either by optimizing the structural parameters of the pristine carbon supports or by increasing the initial metal content above 0.2 wt% Fe on the carbon support; (2) increasing the catalyst loading in the cathodic layer of a PEM fuel cell. For (1), we show, on the one hand, that optimizing the structural parameters of the pristine carbon support, in order to increase the number of catalytic sites, has its limits and that these limits have been reached for the present synthesis method of Fe/N/C catalysts. On the other hand, increasing the initial metal content above 0.2 wt% Fe leads to a decrease in catalytic activity. For (2), it is shown that increasing the catalyst loading per cm² of cathode well improves the performance of a cathode based on Fe/N/C catalysts in the kinetic region of the polarization curve. At lower potentials, a large improvement in the performance of these non-precious metal cathodes would occur if the mass transport properties in these electrodes were significantly increased.     

Sorption and degradation of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine in soil

The sorption/desorption and long-term fate of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) was examined using sterilized and nonsterilized soils. Two soils were used that differ mainly by the amount of total organic carbon (TOC): an agricultural topsoil (VT, 8.4% TOC) and a sandy soil (SSL, 0.33% TOC). The adsorption isotherms performed at room temperature were well-described by a linear model, which led to sorption distribution coefficients of 2.5 and 0.7 L kg(-1) for VT and SSL soils, respectively. The organic content of soil did not significantly affect HMX sorption. Over a period of 20 weeks, HMX degraded (60% disappearance) in static anaerobic nonsterile VT soil preparations. In separate experiments using UL-[14C]-HMX, 19% mineralization (liberated 14CO2) was obtained in 30 weeks. In addition, four nitroso derivatives of HMX were detected. Knowing the sorption/desorption behavior and the long-term fate of HMX in soil will help assess the effectiveness of natural attenuation for HMX removal.