Transient Marangoni convection in hanging evaporating drops

Abstract. A combined experimental and numerical analysis has been carried out to study Marangoni effects during the evaporation of droplets. The experiments are performed with pendant drops of silicone oils (with different viscosities) and hydrocarbons. The temperature of the disk sustaining the drop is rapidly increased or decreased in order to study transient heating or cooling processes. The velocity field in the droplet is evaluated monitoring the motion of tracers in the meridian plane, using a laser sheet illumination system and a video camera. Surface temperature distributions of the drops are detected by infrared thermocamera. The numerical model is based on axisymmetric Navier-Stokes equations, taking into account the presence of Marangoni shear stresses and evaporative cooling at the liquid-air interface. Marangoni flows cause a larger, more uniform surface temperature, increasing heat transfer from disk to droplet, as well as evaporation rate. When Marangoni effects are negligible, larger surface temperature differences occur along the drop surface and heat transfer is relatively small. The role of Marangoni and buoyancy flows in silicone oils with different viscosities and hydrocarbons is discussed and correlations are presented between experimental and numerical results. Keywords: Viscosity of liquids; diffusive momentum transport, Evaporation and condensation, Surface tension and related phenomena, Flows in ducts, channels, nozzles, and conduit

Buoyancy and surface tension-driven convection around a bubble

A combined experimental and numerical analysis has been carried out to study the behavior of a bubble under a horizontal heated surface. In this configuration, the interaction between buoyancy and surface tension driven convection produces complex fluid dynamic structures. An instability occurs in the form of an oscillatory three-dimensional fluctuation of the thermal and velocity field when a critical temperature difference is exceeded. The structure of this flow regime has been investigated with transient three-dimensional simulations carried out for normal gravity and zero gravity conditions. The velocity field around the bubble has been experimentally analyzed with a ``laser sheet'' technique for the flow visualization and a Wollaston prism interferometer has been utilized to capture the oscillatory temperature field. Good correlations are shown between experimental and numerical results. Keywords: Thermal convection, Buoyancy-driven instabilities, Surface-tension-driven instability, Interaction

Numerical and Experimental Studies of Wave Propagation Induced by Pile Driving

. This paper presents results of numerical and experimental studies to predict the peak particle velocity (ppv) induced by a pile driving. By utilizing a professional finite element software, Plaxis 2D Dynamic, this study analyzed ppv due to pile driving in clays for various soil stiffness and various embedded pile lengths. For verification, a full scale field test of pile driving was performed in East Kalimantan with installed instrumentations of accelerations. Results of both instrumentation and numerical analysis show that ppv depends on distance and soil rigidity. The closer the object to pile tip, the larger the ppv that will be produced. The more rigid the soils at the pile tip, the larger the ppv, too. The results also show that both field test and numerical analysis results are comparable. Finally, this paper proposes a chart to predict the ppv of soils due to pile driving in clays. The output of the proposed method is the predicted ppv for various distances from pile driving location

Glucose-6-phosphate dehydrogenase plays a crucial role in the protection from redox-stress induced apoptosis.

Glucose-6-phosphate dehydrogenase-deleted embryonic stem (ES) cells (G6pdD) proliferate in vitro without special requirements, but when challenged with oxidants fail to sustain glutathione disulphide reconversion to reduced glutathione (GSH), entering a condition of oxidative stress. Here, we investigate the signalling events downstream of GSH oxidation in G6pdD and wild-type (wt) ES cells. We found that G6pdD ES cells are very sensitive to oxidants, activating an apoptotic pathway at oxidant concentrations otherwise sublethal for wt ES cells. We show that the apoptotic pathway activated by low oxidant concentrations is accompanied by mitochondria dysfunction, and it is therefore blocked by the overexpression of Bcl-XL. Bcl-XL does not inhibit the decrease in cellular GSH and reactive oxygen species formation following oxidant treatment. We also found that oxidant treatment in ES cells is followed by the activation of the MEK/ extracellular signal-regulated kinase (ERK) pathway. Interest¬ingly, ERK activation has opposite outcomes in G6pdD ES cells compared to wt, which has a proapoptotic function in the first and a prosurvival function in the latter. We show that this phenomenon can be regulated by the cellular GSH level

Scaling up health knowledge at European level requires sharing integrated data: An approach for collection of database specification

Computerized health care databases have been widely described as an excellent opportunity for research. The availability of “big data” has brought about a wave of innovation in projects when conducting health services research. Most of the available secondary data sources are restricted to the geographical scope of a given country and present heterogeneous structure and content. Under the umbrella of the European Innovation Partnership on Active and Healthy Ageing, collaborative work conducted by the partners of the group on “adherence to prescription and medical plans” identified the use of observational and large-population databases to monitor medication-taking behavior in the elderly. This article describes the methodology used to gather the information from available databases among the Adherence Action Group partners with the aim of improving data sharing on a European level. A total of six databases belonging to three different European countries (Spain, Republic of Ireland, and Italy) were included in the analysis. Preliminary results suggest that there are some similarities. However, these results should be applied in different contexts and European countries, supporting the idea that large European studies should be designed in order to get the most of already available databases

Phenolic compounds from Achillea millefolium L. and their bioactivity

Since antiquity, Achillea millefolium L. (Asteraceae) has been used in traditional medicine of several cultures, from Europe to Asia. Its richness in bioactive compounds contributes to a wide range of medicinal properties. In this study, we assessed A. millefolium methanolic extract and its isolated components for free radical scavenging activity against 2,2-diphenyl-pycrilhydrazyl, total antioxidant capacity (based on the reduction of Cu ++ to Cu +), and ability to inhibit lipid peroxidation. The activity against chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum was also tested. Chlorogenic acid, its derivatives and some flavonoids isolated by semipreparative HPLC and identified by NMR and spectrometric techniques were the major bioactive constituents of the methanolic extract. The latter exhibited significant antioxidant properties, as well as its flavonol glycosides and chlorogenic acids. With regard to the antiplasmodial activity, apigenin 7-glucoside was the most effective compound, followed by luteolin 7-glucoside, whereas chlorogenic acids were completely inactive. On the whole, our results confirmed A. millefolium as an important source of bioactive metabolites, justifying its pharmaceutical and ethnobotanical use

The Comparison of High-Intensity Interval Exercise vs. Continuous Moderate-Intensity Exercise on C1q/TNF-Related Protein-9 Expression and Flow-Mediated Vasodilation in Obese Individuals

PURPOSE: A recent novel adipocytokine, C1q/TNF-related protein-9 (CTRP9), has been shown to increase activation of endothelial nitric oxide synthase and reduce vasoconstrictors (e.g., endothelin-1). In addition, CTRP9 may play a compensatory role in obesity-related endothelial dysfunction. Although there is limited information regarding exercise-mediated CTRP9, high-intensity interval exercise (HIIE) has been shown to be as or more effective than continuous moderate-intensity exercise (CME) in improving indicators of endothelial function (e.g., brachial artery flow-mediated dilation [BAFMD]). Therefore, the purpose of this study was to investigate the effect of acute HIIE vs. CME on serum CTRP9 and BAFMD responses in obese individuals. METHODS: Sixteen young male subjects (9 obese and 7 normal-weight) participated in a counterbalanced and caloric equated experiment: HIIE (30 minutes, 4 intervals of 4 minutes at 80-90% of VO2max with 3 minutes rest between intervals) and CME (38 minutes at 50-60% VO2max). Serum CTRP9 and BAFMD, were measured prior to, immediately following exercise, and 1 hour and 2 hours into recovery. RESULTS: The concentration of serum CTRP9 was significantly increased immediately following acute HIIE and CME in both obese and normal-weight groups (p = 0.003). Furthermore, both significant treatment by time and group by time interactions for BAFMD were observed following both exercise protocols (p = 0.018; p = 0.009; respectively), with a greater CME-induced BAFMD response at 2 hours into recovery in obese compared to normal-weight subjects. Additionally, a positive correlation in percent change (baseline to peak value) between CTRP9 and BAFMD was found following acute CME (r = 0.589, p = 0.016). CONCLUSIONS: Acute HIIE is as effective as CME to upregulate CTRP9 expression in both obese and normal-weight individuals, although CTRP9 may potentially improve CME-mediated BAFMD. The novel results from this study provide a foundation for additional examination of the mechanisms of exercise-mediated CTRP9 on endothelial function

Flower selection of Xylocopa violacea: aromatic and ornamental plants as resources in a botanic garden

We assessed the interactions between aromatic and ornamentals plants and local pollinators in a botanic garden. We focused our attention on a frequent solitary bee, Xylocopa violacea, that thanks to its large size and its feeding preferences can visit many types of flowers. By conducting linear walking transects, we recorded all flower visits by bees, highlighting those of X. violacea. We analysed bee preferences in terms of plant family, plant origin or flower morphology. We also identified plant species that were visited by X. violacea together with other foraging bees. Results indicated that X. violacea selectively visits flowering plant species at the botanic garden, preferring Lamiaceae and bilabiate flower types on which legitimate or illegitimate visits can be performed. Other bee species do concurrently visit the same plants, and in the future studies on competition, resource exploitation and pollination success will be addressed

1053pdgenomics features gf and integration with mri radiomics features rf to develop a prognostic model in oral cavity squamous cell carcinoma oscc

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