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Sample records for subjects regulatory drop

  1. Objective and subjective assessing efficacy of a lubricating drop in eyes wearing silicone hydrogel contact lenses

    Directory of Open Access Journals (Sweden)

    Amir Asharlous

    2016-06-01

    Conclusion: Our results showed that although the lubricating drop did not improve the tear film stability and optical quality in the silicone hydrogel contact lens wearers, subjects experienced a subjective improvement.

  2. Measuring Quality of Life in Stroke Subjects Receiving an Implanted Neural Prosthesis for Drop Foot

    NARCIS (Netherlands)

    Kottink, Anke I.; IJzerman, Maarten Joost; Hermens, Hermanus J.; Groothuis-Oudshoorn, Catharina Gerarda Maria; Kottink, A.I.R.

    2010-01-01

    The aim was to determine if the treatment of a drop foot by means of an implantable two-channel peroneal nerve stimulator improves health-related quality of life (HRQoL). All subjects were measured at baseline and after a follow-up period of 12 and 26 weeks. Twenty-nine stroke survivors with chronic

  3. Conducting drops subject to electric fields in 2D Stokes flows

    Science.gov (United States)

    Crowdy, Darren

    2008-10-01

    This paper presents an analysis of a variety of problems of electrohydrodynamics involving conducting uncharged drops (or bubbles) in 2D Stokes flow. The assumption of an uncharged droplet implies that there is no net force on the bubble and, hence, that a solution to this 2D problem is not disqualified by a Stokes paradox' phenomenon. We first study the dynamics of conducting, incompressible bubbles subject to electric fields and ambient straining flows and then extend the scope to include compressible bubbles containing ideal gas. The free boundary problems are first studied using full numerical simulations based on a complex variable formulation coupled with conformal mapping theory. It is found that even under the combined effects of surface tension, electric field effects, compressibility and ambient strain flows, there exist equilibria for the bubble shape which are remarkably close to elliptical. Therefore, in each case, a simple model system of (at most two) non-linear, non-local ordinary differential equations is proposed which is found to approximate the dynamics up to equilibrium to high accuracy.

  4. Increased medial foot loading during drop jump in subjects with patellofemoral pain

    DEFF Research Database (Denmark)

    Rathleff, Michael S; Richter, Camilla; Brushøj, Christoffer

    2014-01-01

    PURPOSE: To compare medial-to-lateral plantar forces during drop jump and single leg squat in individuals with and without patellofemoral pain. METHODS: This cross-sectional study compared 23 young adults with patellofemoral pain to 20 age- and sex-matched controls without knee pain. The plantar...... pressure distribution was collected during drop jump and single leg squat using pressure-sensitive Pedar insoles, inserted into a standard flat shoe. The primary outcome was the medial-to-lateral force, quantified as the peak force under the medial forefoot as the percentage of force under the total...... forefoot during drop jump. Secondary outcomes included peak medial-to-lateral force during single leg squat and mean forces during drop jump and single leg squat. RESULTS: The primary outcome showed that individuals with patellofemoral pain had a 22 % higher medial-to-lateral peak force during drop jump...

  5. Negative Pressures and Spallation in Water Drops Subjected to Nanosecond Shock Waves.

    Science.gov (United States)

    Stan, Claudiu A; Willmott, Philip R; Stone, Howard A; Koglin, Jason E; Liang, Mengning; Aquila, Andrew L; Robinson, Joseph S; Gumerlock, Karl L; Blaj, Gabriel; Sierra, Raymond G; Boutet, Sébastien; Guillet, Serge A H; Curtis, Robin H; Vetter, Sharon L; Loos, Henrik; Turner, James L; Decker, Franz-Josef

    2016-06-02

    Most experimental studies of cavitation in liquid water at negative pressures reported cavitation at tensions significantly smaller than those expected for homogeneous nucleation, suggesting that achievable tensions are limited by heterogeneous cavitation. We generated tension pulses with nanosecond rise times in water by reflecting cylindrical shock waves, produced by X-ray laser pulses, at the internal surface of drops of water. Depending on the X-ray pulse energy, a range of cavitation phenomena occurred, including the rupture and detachment, or spallation, of thin liquid layers at the surface of the drop. When spallation occurred, we evaluated that negative pressures below -100 MPa were reached in the drops. We model the negative pressures from shock reflection experiments using a nucleation-and-growth model that explains how rapid decompression could outrun heterogeneous cavitation in water, and enable the study of stretched water close to homogeneous cavitation pressures.

  6. Multi-scale Analysis of MEMS Sensors Subject to Drop Impacts

    Directory of Open Access Journals (Sweden)

    Sarah Zerbini

    2007-09-01

    Full Text Available The effect of accidental drops on MEMS sensors are examined within the frame-work of a multi-scale finite element approach. With specific reference to a polysilicon MEMSaccelerometer supported by a naked die, the analysis is decoupled into macro-scale (at dielength-scale and meso-scale (at MEMS length-scale simulations, accounting for the verysmall inertial contribution of the sensor to the overall dynamics of the device. Macro-scaleanalyses are adopted to get insights into the link between shock waves caused by the impactagainst a target surface and propagating inside the die, and the displacement/acceleration his-tories at the MEMS anchor points. Meso-scale analyses are adopted to detect the most stresseddetails of the sensor and to assess whether the impact can lead to possible localized failures.Numerical results show that the acceleration at sensor anchors cannot be considered an ob-jective indicator for drop severity. Instead, accurate analyses at sensor level are necessary toestablish how MEMS can fail because of drops.

  7. Effect of kinesiotaping, non-elastic taping and bracing on segmental foot kinematics during drop landing in healthy subjects and subjects with chronic ankle instability.

    Science.gov (United States)

    Kuni, B; Mussler, J; Kalkum, E; Schmitt, H; Wolf, S I

    2016-09-01

    To evaluate the effects of kinesiotape, non-elastic tape, and soft brace on segmental foot kinematics during drop landing in subjects with chronic ankle instability and healthy subjects. Controlled study with repeated measurements. Three-dimensional motion analysis laboratory. Twenty participants with chronic ankle instability and 20 healthy subjects. The subjects performed drop landings with 17 retroreflective markers on the foot and lower leg in four conditions: barefoot, with kinesiotape, with non-elastic tape and with a soft brace. Ranges of motion of foot segments using a foot measurement method. In participants with chronic ankle instability, midfoot movement in the frontal plane (inclination of the medial arch) was reduced significantly by non-elastic taping, but kinesiotaping and bracing had no effect. In healthy subjects, both non-elastic taping and bracing reduced that movement. In both groups, non-elastic taping and bracing reduced rearfoot excursion in inversion/eversion significantly, which indicates a stabilisation effect. No such effect was found with kinesiotaping. All three methods reduced maximum plantar flexion significantly. Non-elastic taping stabilised the midfoot best in patients with chronic ankle instability, while kinesiotaping did not influence foot kinematics other than to stabilise the rearfoot in the sagittal plane. ClinicalTrials.gov NCT01810471. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  8. Experimental and computational studies of water drops falling through model oil with surfactant and subjected to an electric field

    CERN Document Server

    Ervik, Åsmund; Munkejord, Svend Tollak; Müller, Bernhard

    2014-01-01

    The behaviour of a single sub-millimetre-size water drop falling through a viscous oil while subjected to an electric field is of fundamental importance to industrial applications such as crude oil electrocoalescers. Detailed studies, both experimental and computational, have been performed previously, but an often challenging issue has been the characterization of the fluids. As numerous authors have noted, it is very difficult to have a perfectly clean water-oil system even for very pure model oils, and the presence of trace chemicals may significantly alter the interface behaviour. In this work, we consider a well- characterized water-oil system where controlled amounts of a surface active agent (Span 80) have been added to the oil. This addition dominates any trace contaminants in the oil, such that the interface behaviour can also be well-characterized. We present the results of experiments and corresponding two-phase- flow simulations of a falling water drop covered in surfactant and subjected to a mono...

  9. Gait assessment during the initial fitting of customized selective laser sintering ankle foot orthoses in subjects with drop foot.

    Science.gov (United States)

    Creylman, Veerle; Muraru, Luiza; Pallari, Jari; Vertommen, Helga; Peeraer, Louis

    2013-04-01

    Recently, additive fabrication has been proposed as a feasible engineering method for manufacturing of customized ankle foot orthoses (AFOs). Consequently, studies on safety, comfort and effectiveness are now carried out to assess the performance of such devices. Evaluate the clinical performance of customized (selective laser sintering) SLS-AFOs on eight subjects with unilateral drop foot gait and compare to clinically accepted (polypropylene) PP-AFOs. Active control trial. For each subject two customized AFOs were fabricated: one SLS-AFO manufactured following an additive fabrication framework and one thermoplastic PP-AFO manufactured according to the traditional handcraft method. Clinical performance of both AFOs was evaluated during gait analysis. A significant beneficial effect of both custom-moulded PP-AFO and customized SLS-AFO in terms of spatial temporal gait parameters and ankle kinematic parameters compared to barefoot gait of adults with drop foot gait are observed. No statistically significant difference between the effect of PP-AFO and of SLS-AFO was found in terms of spatial temporal gait parameters and ankle kinematic parameters. AFOs manufactured through the SLS technique show performances that are at least equivalent to the handcrafted PP-AFOs commonly prescribed in current clinical practice. Clinical relevance Manufacturing personalized AFOs with selective laser sintering (SLS) in an automated production process results in decreased production time and guarantees the consistency of shape and functional characteristics over different production time points compared to the traditional manufacturing process. Moreover, it reduces the dependency of the appliance on the experience and craftsmanship of the orthopaedic technician.

  10. Biorepository regulatory frameworks: building parallel resources that both promote scientific investigation and protect human subjects.

    Science.gov (United States)

    Marko-Varga, György; Baker, Mark S; Boja, Emily S; Rodriguez, Henry; Fehniger, Thomas E

    2014-12-05

    Clinical samples contained in biorepositories represent an important resource for investigating the many factors that drive human biology. The biological and chemical markers contained in clinical samples provide important measures of health and disease that when combined with such medical evaluation data can aid in decision making by physicians. Nearly all disciplines in medicine and every "omic" depend upon the readouts obtained from such samples, whether the measured analyte is a gene, a protein, a lipid, or a metabolite. There are many steps in sample processing, storage, and management that need to understood by the researchers who utilize biorepositories in their own work. These include not only the preservation of the desired analytes in the sample but also good understanding of the moral and legal framework required for subject protection irrespective of where the samples have been collected. Today there is a great deal of effort in the community to align and standardize both the methodology of sample collection and storage performed in different locations and the necessary frameworks of subject protection including informed consent and institutional review of the studies being performed. There is a growing trend in developing biorepositories around the focus of large population-based studies that address both active and silent nonsymptomatic disease. Logistically these studies generate large numbers of clinical samples and practically place increasing demand upon health care systems to provide uniform sample handling, processing, storage, and documentation of both the sample and the subject as well to ensure that safeguards exist to protect the rights of the study subjects for deciding upon the fates of their samples. Currently the authority to regulate the entire scope of biorepository usage exists as national practice in law in only a few countries. Such legal protection is a necessary component within the framework of biorepositories, both now and in

  11. Gene expression of regulatory enzymes involved in the intermediate metabolism of sheep subjected to feed restriction.

    Science.gov (United States)

    van Harten, S; Brito, R; Almeida, A M; Scanlon, T; Kilminster, T; Milton, J; Greeff, J; Oldham, C; Cardoso, L A

    2013-03-01

    The effect of feed restriction on gene expression of regulatory enzymes of intermediary metabolism was studied in two sheep breeds (Australian Merino and Dorper) subjected to two nutritional treatments: feed restriction (85% of daily maintenance requirements) and control (ad libitum feeding), during 42 days. The experimental animals (ram lambs) were divided into four groups, n = 5 (Australian Merino control (MC), Australian Merino Restriction (MR), Dorper control (DC) and Dorper Restriction (DR)). After the trial, animals were sacrificed and samples were taken from liver tissue to quantify glucose levels and gene expression of relevant intermediary metabolism enzymes (phosphofructokinase (PFK), pyruvate kinase (PK), phosphoenolpyruvate carboxykinase, fructose 1,6-bisphosphatase, glucose-6-phosphatase, glycogen synthase (GS), fatty acid synthase (FAS), glutamate dehydrogenase (GDH) and carbamoyl phosphate synthase (CPS)) through real-time PCR. During the experimental period, the MR animals lost 12.6% in BW compared with 5.3% lost by the Dorper lambs. MC and DC rams gained, respectively, 8.8% and 14% during the same period. Within the Dorper breed, restricted feed animals revealed a significant decrease over controls in the transcription of PFK (1.95-fold) and PK (2.26-fold), both glycolytic enzymes. The gluconeogenesis showed no change in the feed restricted animals of both breeds. DR feed group presented a significant decrease over the homologous Merino sheep group on GS. In both experimental breeds, FAS mRNA expression was decreased in restricted feed groups. GDH expression was decreased only in the DR animals (1.84-fold) indicating a reduced catabolism of amino acids in these animals. Finally, CPS was significantly (P enzymes and hepatic glucose production of Dorper sheep to feed restriction concurring with the BW results in the experimental groups.

  12. Foot Drop

    Science.gov (United States)

    ... Seizures Information Page Fibromuscular Dysplasia Information Page Foot Drop Information Page Friedreich's Ataxia Information Page Gaucher Disease Information Page Generalized Gangliosidoses Information Page Gerstmann's Syndrome ...

  13. Subjectivity

    Directory of Open Access Journals (Sweden)

    Jesús Vega Encabo

    2015-11-01

    Full Text Available In this paper, I claim that subjectivity is a way of being that is constituted through a set of practices in which the self is subject to the dangers of fictionalizing and plotting her life and self-image. I examine some ways of becoming subject through narratives and through theatrical performance before others. Through these practices, a real and active subjectivity is revealed, capable of self-knowledge and self-transformation. 

  14. The Effect of Diluted Penetration Enhancer in Nebulized Mist versus Liquid Drop Preparation Forms on Retrobulbar Blood Flow in Healthy Human Subjects

    Directory of Open Access Journals (Sweden)

    Ruta Barsauskaite

    2012-08-01

    Full Text Available The aim of this study was to compare the effects of nebulized mist and liquid drop applications on retrobulbar blood flow. A prospective, non-randomized clinical trial was used to collect data from 40 healthy human eyes. Color Doppler Imaging determined peak systolic (PSV and end diastolic (EDV blood flow velocities and resistance index (RI in the ophthalmic artery after both applications. Measurements were taken at baseline and at 1 min post-treatment in both eyes with 5 min measurements in the treatment eye only. p values ≤ 0.05 were considered statistically significant. Mist application to treatment eye produced an increase in 1 min and 5 min PSV and EDV (0.001 < p < 0.03 and a decrease in 5 min RI (p = 0.01, with no significant changes in PSV, EDV or RI of control eye or in treatment eye 1 min RI (p > 0.05. Drop application to treatment eye produced an increase in PSV (p < 0.001 and EDV (p = 0.01 at 1 min, with an increase in control eye 1 min PSV and EDV (p = 0.03. There were no statistically significant changes in treatment eye PSV, EDV and RI after 5 min (p > 0.05. The use of nebulized mist may provide an effective alternative to liquid drop medication application.

  15. Carica papaya increases regulatory T cells and reduces IFN-γ+ CD4+ T cells in healthy human subjects.

    Science.gov (United States)

    Abdullah, Maha; Chai, Pei-Shin; Loh, Chiew-Yee; Chong, Mun-Yee; Quay, Huai-Wei; Vidyadaran, Sharmili; Seman, Zainina; Kandiah, Mirnalini; Seow, Heng-Fong

    2011-05-01

    Fruit and vegetables have therapeutic potential as they dampen inflammation, have no known side-effects and as whole foods have prospective additive and synergistic benefits. Th1 (IFN-γ(+) CD4(+))/Th2 (IL-4(+)CD4(+)) T cells play a vital role in mediating inflammatory responses and may be regulated by regulatory T cells (Tregs). Effects of Carica papaya on cells of healthy individuals were determined using flow cytometry methods. Significant down-regulation of IFN-γ(+) CD4(+) (p=0.03, n=13), up-regulation of IL-4(+) CD4(+) (p=0.04, n=13) T cells and up-regulation of CD3(+) CD4(+) CD25(+) CD127(-) (p=0.001, n=15) Tregs were observed after papaya consumption. In vitro cultures showed up-regulation of Tregs in male subjects and was significantly associated with levels of IL-1β in culture supernatants (R(2) =0.608, p=0.04, n=12). Other inflammatory cytokines were significantly suppressed. Papaya consumption may exert an anti-inflammatory response mediated through Tregs and have potential in alleviating inflammatory conditions. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Prediction of load threshold of fibre-reinforced laminated composite panels subjected to low velocity drop-weight impact using efficient data filtering techniques

    Directory of Open Access Journals (Sweden)

    Umar Farooq

    2015-01-01

    Full Text Available This work is concerned with physical testing of carbon fibrous laminated composite panels with low velocity drop-weight impacts from flat and round nose impactors. Eight, sixteen, and twenty-four ply panels were considered. Non-destructive damage inspections of tested specimens were conducted to approximate impact-induced damage. Recorded data were correlated to load–time, load–deflection, and energy–time history plots to interpret impact induced damage. Data filtering techniques were also applied to the noisy data that unavoidably generate due to limitations of testing and logging systems. Built-in, statistical, and numerical filters effectively predicted load thresholds for eight and sixteen ply laminates. However, flat nose impact of twenty-four ply laminates produced clipped data that can only be de-noised involving oscillatory algorithms. Data filtering and extrapolation of such data have received rare attention in the literature that needs to be investigated. The present work demonstrated filtering and extrapolation of the clipped data using Fast Fourier Convolution algorithm to predict load thresholds. Selected results were compared to the damage zones identified with C-scan and acceptable agreements have been observed. Based on the results it is proposed that use of advanced data filtering and analysis methods to data collected by the available resources has effectively enhanced data interpretations without resorting to additional resources. The methodology could be useful for efficient and reliable data analysis and impact-induced damage prediction of similar cases’ data.

  17. Short-term effects of sports taping on navicular height, navicular drop and peak plantar pressure in healthy elite athletes: A within-subject comparison.

    Science.gov (United States)

    Kim, Taegyu; Park, Jong-Chul

    2017-11-01

    Medial tibial stress syndrome (MTSS) is one of the most common exercise-induced leg pain. The navicular drop (ND) was identified as a risk factor for MTSS. This study aimed to evaluate the short-term effects of sports taping applied to the supporting lower leg during sitting, standing, walking, and jogging to restrict the ND in healthy elite athletes.Twenty-four healthy elite athletes without a history of exercise-induced pain or injuries in the lower limbs participated in this study (median age: 21.00 years; 1st--3rd quartiles; 19.25-22.00). The 4 taping conditions were used: rigid taping (RT), kinesiology taping (KT), placebo taping (PT), and non-taping (NT). The order of taping techniques was randomly assigned. Normalized navicular height (NH), ND, and normalized ND evaluated using 3-dimensional motion analysis, and normalized peak plantar pressure (PP) were compared in 4 taping conditions during sitting, standing, walking, and jogging.During sitting, the normalized NH of RT is higher than that of NT, KT, and PT (χ = 17.30, P = .001), while during jogging, the normalized NH of RT is higher than that of NT and PT (χ = 10.55, P = .014). The normalized peak PP of NT is higher than that of PT (χ = 8.871, P = .031) in the lateral midfoot region.This study showed the RT technique maintained NH during sitting and jogging, and the RT technique could be an effective preventive and treatment strategy for MTSS.

  18. Dilating Eye Drops

    Science.gov (United States)

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Dilating Eye Drops En Español Read in Chinese What are dilating eye drops? Dilating eye drops contain medication to enlarge ( ...

  19. Regulatory B Cell Function Is Suppressed by Smoking and Obesity in H. pylori-Infected Subjects and Is Correlated with Elevated Risk of Gastric Cancer.

    Science.gov (United States)

    Li, Guanggang; Wulan, Hasi; Song, Zongchang; Paik, Paul A; Tsao, Ming L; Goodman, Gary M; MacEachern, Paul T; Downey, Robert S; Jankowska, Anna J; Rabinowitz, Yaron M; Learch, Thomas B; Song, David Z; Yuan, Ji J; Zheng, Shihang; Zheng, Zhendong

    2015-01-01

    Helicobacter pylori infection occurs in more than half of the world's population and is the main cause for gastric cancer. A series of lifestyle and nutritional factors, such as tobacco smoking and obesity, have been found to elevate the risk for cancer development. In this study, we sought to determine the immunological aspects during H. pylori infection and gastric cancer development. We found that B cells from H. pylori-infected patients presented altered composition and function compared to uninfected patients. IL-10-expressing CD24+CD38+ B cells were upregulated in H. pylori-infected patients, contained potent regulatory activity in inhibiting T cell pro-inflammatory cytokine secretion, and responded directly to H. pylori antigen stimulation. Interestingly, in H. pylori-infected smoking subjects and obese subjects, the number of IL-10+ B cells and CD24+CD38+ B cells were reduced compared to H. pylori-infected asymptomatic subjects. Regulatory functions mediated by CD24+CD38+ B cells were also impaired. In addition, gastric cancer positive patients had reduced IL-10-producing B cell frequencies after H. pylori-stimulation. Altogether, these data suggest that in H. pylori-infection, CD24+CD38+ B cell is upregulated and plays a role in suppressing pro-inflammatory responses, possibly through IL-10 production, a feature that was not observed in smoking and obese patients.

  20. Regulatory B Cell Function Is Suppressed by Smoking and Obesity in H. pylori-Infected Subjects and Is Correlated with Elevated Risk of Gastric Cancer.

    Directory of Open Access Journals (Sweden)

    Guanggang Li

    Full Text Available Helicobacter pylori infection occurs in more than half of the world's population and is the main cause for gastric cancer. A series of lifestyle and nutritional factors, such as tobacco smoking and obesity, have been found to elevate the risk for cancer development. In this study, we sought to determine the immunological aspects during H. pylori infection and gastric cancer development. We found that B cells from H. pylori-infected patients presented altered composition and function compared to uninfected patients. IL-10-expressing CD24+CD38+ B cells were upregulated in H. pylori-infected patients, contained potent regulatory activity in inhibiting T cell pro-inflammatory cytokine secretion, and responded directly to H. pylori antigen stimulation. Interestingly, in H. pylori-infected smoking subjects and obese subjects, the number of IL-10+ B cells and CD24+CD38+ B cells were reduced compared to H. pylori-infected asymptomatic subjects. Regulatory functions mediated by CD24+CD38+ B cells were also impaired. In addition, gastric cancer positive patients had reduced IL-10-producing B cell frequencies after H. pylori-stimulation. Altogether, these data suggest that in H. pylori-infection, CD24+CD38+ B cell is upregulated and plays a role in suppressing pro-inflammatory responses, possibly through IL-10 production, a feature that was not observed in smoking and obese patients.

  1. Eye Drop Tips

    Science.gov (United States)

    ... Involved News About Us Donate In This Section Eye Drop Tips en Español email Send this article ... the reach of children. Steps For Putting In Eye Drops: Start by tilting your head backward while ...

  2. Differential Phenotypes of Myeloid-Derived Suppressor and T Regulatory Cells and Cytokine Levels in Amnestic Mild Cognitive Impairment Subjects Compared to Mild Alzheimer Diseased Patients

    Directory of Open Access Journals (Sweden)

    Aurélie Le Page

    2017-07-01

    Full Text Available Alzheimer disease (AD is the most prevalent form of dementia although the underlying cause(s remains unknown at this time. However, neuroinflammation is believed to play an important role and suspected contributing immune parameters can be revealed in studies comparing patients at the stage of amnestic mild cognitive impairment (aMCI to healthy age-matched individuals. A network of immune regulatory cells including regulatory T cells (Tregs and myeloid-derived suppressor cells (MDSCs maintains immune homeostasis but there are very few data on the role of these cells in AD. Here, we investigated the presence of these cells in the blood of subjects with aMCI and mild AD (mAD in comparison with healthy age-matched controls. We also quantitated several pro- and anti-inflammatory cytokines in sera which can influence the development and activation of these cells. We found significantly higher levels of MDSCs and Tregs in aMCI but not in mAD patients, as well as higher serum IL-1β levels. Stratifying the subjects based on CMV serostatus that is known to influence multiple immune parameters showed an absence of differences between aMCI subjects compared to mAD patients and healthy controls. We suggest that the increase in MDSCs and Tregs number in aMCI subjects may have a beneficial role in modulating inflammatory processes. However, this protective mechanism may have failed in mAD patients, allowing progression of the disease. This working hypothesis obviously requires testing in future studies.

  3. Studies of Drop/Drop and Drop/Interface Impact

    Science.gov (United States)

    Lowengrub, John; Cristini, Vittorio; Kim, Jun-Seok; Zheng, Xiaoming; Mohammed-Kassim, Zulfaa; Longmire, Ellen

    2003-11-01

    In this talk, we will study the impact and coalescence of liquid drops using a physically-based numerical model that allows seamless transitions in interface topologies combined with adaptive mesh refinement. By using a mesh size that is adaptive to the length scales associated to the lubrication pressure generated by interfaces in near contact, we accurately describe the near contact motion and recover the predictions of asymptotic analyses. We compare simulation results to recent experiments performed by Mohamed-Kassim and Longmire. The effects of multiple drops, van der Waal forces and surfactants will also be considered.

  4. Effects of itopride hydrochloride on plasma gut-regulatory peptide and stress-related hormone levels in healthy human subjects.

    Science.gov (United States)

    Katagiri, Fumihiko; Shiga, Toru; Inoue, Shin; Sato, Yuhki; Itoh, Hiroki; Takeyama, Masaharu

    2006-01-01

    Itopride hydrochloride (itopride), a gastrokinetic drug, has recently been evaluated for its clinical usefulness in functional dyspepsia. We investigated effects of itopride on human plasma gastrin-, somatostatin-, motilin-, and cholecystokinin (CCK)-like immunoreactive substances (IS); adrenocorticotropic hormone (ACTH)-immunoreactive substances (IS), and cortisol under stress conditions in healthy subjects. A single administration of itopride caused significant increases in plasma somatostatin- and motilin-IS levels compared to placebo. Itopride significantly decreased plasma CCK-IS, and suppressed the ACTH-IS level compared to placebo. We hypothesize that itopride may have an accelerating gastric emptying effect, and a modulatory effect on the hypothalamo-pituitary-adrenal axis and autonomic nervous functions. These effects might be beneficial in stress-related diseases, suggesting that itopride has clinicopharmacological activities.

  5. Seismic II over I Drop Test Program results and interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, B.

    1993-03-01

    The consequences of non-seismically qualified (Category 2) objects falling and striking essential seismically qualified (Category 1) objects has always been a significant, yet analytically difficult problem, particularly in evaluating the potential damage to equipment that may result from earthquakes. Analytical solutions for impact problems are conservative and available for mostly simple configurations. In a nuclear facility, the {open_quotes}sources{close_quotes} and {open_quotes}targets{close_quotes} requiring evaluation are frequently irregular in shape and configuration, making calculations and computer modeling difficult. Few industry or regulatory rules are available on this topic even though it is a source of considerable construction upgrade costs. A drop test program was recently conducted to develop a more accurate understanding of the consequences of seismic interactions. The resulting data can be used as a means to improve the judgment of seismic qualification engineers performing interaction evaluations and to develop realistic design criteria for seismic interactions. Impact tests on various combinations of sources and targets commonly found in one Savannah River Site (SRS) nuclear facility were performed by dropping the sources from various heights onto the targets. This report summarizes results of the Drop Test Program. Force and acceleration time history data are presented as well as general observations on the overall ruggedness of various targets when subjected to impacts from different types of sources.

  6. Seismic II over I Drop Test Program results and interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, B.

    1993-03-01

    The consequences of non-seismically qualified (Category 2) objects falling and striking essential seismically qualified (Category 1) objects has always been a significant, yet analytically difficult problem, particularly in evaluating the potential damage to equipment that may result from earthquakes. Analytical solutions for impact problems are conservative and available for mostly simple configurations. In a nuclear facility, the [open quotes]sources[close quotes] and [open quotes]targets[close quotes] requiring evaluation are frequently irregular in shape and configuration, making calculations and computer modeling difficult. Few industry or regulatory rules are available on this topic even though it is a source of considerable construction upgrade costs. A drop test program was recently conducted to develop a more accurate understanding of the consequences of seismic interactions. The resulting data can be used as a means to improve the judgment of seismic qualification engineers performing interaction evaluations and to develop realistic design criteria for seismic interactions. Impact tests on various combinations of sources and targets commonly found in one Savannah River Site (SRS) nuclear facility were performed by dropping the sources from various heights onto the targets. This report summarizes results of the Drop Test Program. Force and acceleration time history data are presented as well as general observations on the overall ruggedness of various targets when subjected to impacts from different types of sources.

  7. Scanning drop sensor

    Science.gov (United States)

    Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Shinde, Aniketa A.; Guevarra, Dan W.; Jones, Ryan J.; Marcin, Martin R.; Mitrovic, Slobodan

    2017-05-09

    Electrochemical or electrochemical and photochemical experiments are performed on a collection of samples by suspending a drop of electrolyte solution between an electrochemical experiment probe and one of the samples that serves as a test sample. During the electrochemical experiment, the electrolyte solution is added to the drop and an output solution is removed from the drop. The probe and collection of samples can be moved relative to one another so the probe can be scanned across the samples.

  8. Bubble and drop interfaces

    CERN Document Server

    Miller

    2011-01-01

    The book aims at describing the most important experimental methods for characterizing liquid interfaces, such as drop profile analysis, bubble pressure and drop volume tensiometry, capillary pressure technique, and oscillating drops and bubbles. Besides the details of experimental set ups, also the underlying theoretical basis is presented in detail. In addition, a number of applications based on drops and bubbles is discussed, such as rising bubbles and the very complex process of flotation. Also wetting, characterized by the dynamics of advancing contact angles is discussed critically. Spec

  9. Dynamics of deforming drops

    NARCIS (Netherlands)

    Bouwhuis, W.

    2015-01-01

    Liquid drops play a dominant role in numerous industrial applications, such as spray coating, spray painting, inkjet printing, lithography processes, and spraying/sprinkling in agriculture or gardening. In all of these examples, the generation, flight, impact, and spreading of drops are separate

  10. Lambda-dropping

    DEFF Research Database (Denmark)

    Danvy, Olivier; Schultz, Ulrik Pagh

    1997-01-01

    Lambda-lifting a functional program transforms it into a set of recursive equations. We present the symmetric transformation: lambda-dropping. Lambda-dropping a set of recursive equations restores block structure and lexical scope.For lack of scope, recursive equations must carry around all...... to float (for lambda-lifting) or to sink (for lambda-dropping) along the vertices of the scope tree.We believe lambda-lifting and lambda-dropping are interesting per se, both in principle and in practice, but our prime application is partial evaluation: except for Malmkjær and Ø...... with dozens of parameters, which most compilers do not handle efficiently. Lambda-dropping in a post-processing phase restores their block structure and lexical scope thereby significantly reducing both the compile time and the run time of residual programs....

  11. Fel d 1-derived synthetic peptide immuno-regulatory epitopes show a long-term treatment effect in cat allergic subjects.

    Science.gov (United States)

    Couroux, P; Patel, D; Armstrong, K; Larché, M; Hafner, R P

    2015-05-01

    Cat-PAD, the first in a new class of synthetic peptide immuno-regulatory epitopes (SPIREs), was shown to significantly improve rhinoconjunctivitis symptoms in subjects with cat allergy up to 1 year after the start of a short course of treatment. To evaluate the long-term effects of Cat-PAD on rhinoconjunctivitis symptoms following standardized allergen challenge 2 years after treatment. In a randomized, double-blind, placebo-controlled, parallel group study, subjects were exposed to cat allergen in an environmental exposure chamber (EEC) before and after treatment with two regimens of Cat-PAD (either eight doses of 3 nmol or four doses of 6 nmol) given intradermally over a 3-month period. In this follow-up study, changes from baseline in rhinoconjunctivitis symptoms were reassessed 2 years after the start of treatment. The primary endpoint showed a mean reduction in total rhinoconjunctivitis symptom scores of 3.85 units in the 4 × 6 nmol Cat-PAD group compared to placebo 2 years after the start of treatment (P = 0.13), and this difference was statistically significant in the secondary endpoint at the end of day 4 when the cumulative allergen challenge was greatest (P = 0.02). Consistent reductions in nasal symptoms of between 2 and 3 units were observed for 4 × 6 nmol Cat-PAD compared to placebo between the 2 and 3 h time points on days 1-4 of EEC challenge at 2 years (P Cat-PAD. This study is the first to provide evidence of a long-term therapeutic effect with this new class of SPIREs. © 2015 The Authors. Clinical & Experimental Allergy Published by John Wiley & Sons Ltd.

  12. Self-regulatory mode (locomotion and assessment), well-being (subjective and psychological), and exercise behavior (frequency and intensity) in relation to high school pupils’ academic achievement

    Science.gov (United States)

    Jimmefors, Alexander; Mousavi, Fariba; Adrianson, Lillemor; Rosenberg, Patricia; Archer, Trevor

    2015-01-01

    Background. Self-regulation is the procedure implemented by an individual striving to reach a goal and consists of two inter-related strategies: assessment and locomotion. Moreover, both subjective and psychological well-being along exercise behaviour might also play a role on adolescents academic achievement. Method. Participants were 160 Swedish high school pupils (111 boys and 49 girls) with an age mean of 17.74 (sd = 1.29). We used the Regulatory Mode Questionnaire to measure self-regulation strategies (i.e., locomotion and assessment). Well-being was measured using Ryff’s Psychological Well-Being Scales short version, the Temporal Satisfaction with Life Scale, and the Positive Affect and Negative Affect Schedule. Exercise behaviour was self-reported using questions pertaining to frequency and intensity of exercise compliance. Academic achievement was operationalized through the pupils’ mean value of final grades in Swedish, Mathematics, English, and Physical Education. Both correlation and regressions analyses were conducted. Results. Academic achievement was positively related to assessment, well-being, and frequent/intensive exercise behaviour. Assessment was, however, negatively related to well-being. Locomotion on the other hand was positively associated to well-being and also to exercise behaviour. Conclusions. The results suggest a dual (in)direct model to increase pupils’ academic achievement and well-being—assessment being directly related to higher academic achievement, while locomotion is related to frequently exercising and well-being, which in turn, increase academic achievement. PMID:25861553

  13. Self-regulatory mode (locomotion and assessment), well-being (subjective and psychological), and exercise behavior (frequency and intensity) in relation to high school pupils' academic achievement.

    Science.gov (United States)

    Garcia, Danilo; Jimmefors, Alexander; Mousavi, Fariba; Adrianson, Lillemor; Rosenberg, Patricia; Archer, Trevor

    2015-01-01

    Background. Self-regulation is the procedure implemented by an individual striving to reach a goal and consists of two inter-related strategies: assessment and locomotion. Moreover, both subjective and psychological well-being along exercise behaviour might also play a role on adolescents academic achievement. Method. Participants were 160 Swedish high school pupils (111 boys and 49 girls) with an age mean of 17.74 (sd = 1.29). We used the Regulatory Mode Questionnaire to measure self-regulation strategies (i.e., locomotion and assessment). Well-being was measured using Ryff's Psychological Well-Being Scales short version, the Temporal Satisfaction with Life Scale, and the Positive Affect and Negative Affect Schedule. Exercise behaviour was self-reported using questions pertaining to frequency and intensity of exercise compliance. Academic achievement was operationalized through the pupils' mean value of final grades in Swedish, Mathematics, English, and Physical Education. Both correlation and regressions analyses were conducted. Results. Academic achievement was positively related to assessment, well-being, and frequent/intensive exercise behaviour. Assessment was, however, negatively related to well-being. Locomotion on the other hand was positively associated to well-being and also to exercise behaviour. Conclusions. The results suggest a dual (in)direct model to increase pupils' academic achievement and well-being-assessment being directly related to higher academic achievement, while locomotion is related to frequently exercising and well-being, which in turn, increase academic achievement.

  14. Impact of granular drops

    KAUST Repository

    Marston, J. O.

    2013-07-15

    We investigate the spreading and splashing of granular drops during impact with a solid target. The granular drops are formed from roughly spherical balls of sand mixed with water, which is used as a binder to hold the ball together during free-fall. We measure the instantaneous spread diameter for different impact speeds and find that the normalized spread diameter d/D grows as (tV/D)1/2. The speeds of the grains ejected during the “splash” are measured and they rarely exceed twice that of the impact speed.

  15. Biomechanical analysis of drop and countermovement jumps

    NARCIS (Netherlands)

    Bobbert, M. F.; Mackay, M.T.; Schinkelshoek, D.; Huijing, P. A.; van Ingen Schenau, G. J.

    For 13 subjects the performance of drop jumps from a height of 40 cm (DJ) and of countermovement jumps (CMJ) was analysed and compared. From force plate and cine data biomechanical variables including forces, moments, power output and amount of work done were calculated for hip, knee and ankle

  16. Drop tube technical tasks

    Science.gov (United States)

    Workman, G. L.

    1986-01-01

    Criteria, using fundamental thermochemical dynamics, were developed to assist a scientist using the Drop Tube Facility in designing a good experiment. The types of parameters involved in designing the experiments include the type of furnace, the type of atmosphere, and in general which materials are better behaved than others as determined by past experience in the facility. One of the major advantages of the facility lies in its ability to provide large undercoolings in the cooling curve during the drops. A beginning was to consider the effect of oxygen and other gases upon the amount of undercooling observed. The starting point of the thermochemistry was given by Ellingham and later transformed into what is known as the Richardson Chart. The effect of surface oxidations upon the nucleation phenomena can be observed in each specimen.

  17. Dropped object protection analyses

    OpenAIRE

    Nilsen, Ingve

    2014-01-01

    Master's thesis in Offshore structural engineering Impact from dropped object is a typical accident action (NOKSOK N-004, 2013). Hence, the DOP structure is to be analyzed in an accidental limit state (ALS) design practice, which means that a non-linear finite element analysis can be applied. The DOP structure will be based on a typical DOP structure. Several FEM analyses are performed for the DOP structure. Different shapes size and weights and various impact positions are used for si...

  18. Dropping macadamia nuts-in-shell reduces kernel roasting quality.

    Science.gov (United States)

    Walton, David A; Wallace, Helen M

    2010-10-01

    Macadamia nuts ('nuts-in-shell') are subjected to many impacts from dropping during postharvest handling, resulting in damage to the raw kernel. The effect of dropping on roasted kernel quality is unknown. Macadamia nuts-in-shell were dropped in various combinations of moisture content, number of drops and receiving surface in three experiments. After dropping, samples from each treatment and undropped controls were dry oven-roasted for 20 min at 130 °C, and kernels were assessed for colour, mottled colour and surface damage. Dropping nuts-in-shell onto a bed of nuts-in-shell at 3% moisture content or 20% moisture content increased the percentage of dark roasted kernels. Kernels from nuts dropped first at 20%, then 10% moisture content, onto a metal plate had increased mottled colour. Dropping nuts-in-shell at 3% moisture content onto nuts-in-shell significantly increased surface damage. Similarly, surface damage increased for kernels dropped onto a metal plate at 20%, then at 10% moisture content. Postharvest dropping of macadamia nuts-in-shell causes concealed cellular damage to kernels, the effects not evident until roasting. This damage provides the reagents needed for non-enzymatic browning reactions. Improvements in handling, such as reducing the number of drops and improving handling equipment, will reduce cellular damage and after-roast darkening. Copyright © 2010 Society of Chemical Industry.

  19. Drop Testing Representative Multi-Canister Overpacks

    Energy Technology Data Exchange (ETDEWEB)

    Snow, Spencer D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Morton, Dana K. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    The objective of the work reported herein was to determine the ability of the Multi- Canister Overpack (MCO) canister design to maintain its containment boundary after an accidental drop event. Two test MCO canisters were assembled at Hanford, prepared for testing at the Idaho National Engineering and Environmental Laboratory (INEEL), drop tested at Sandia National Laboratories, and evaluated back at the INEEL. In addition to the actual testing efforts, finite element plastic analysis techniques were used to make both pre-test and post-test predictions of the test MCOs structural deformations. The completed effort has demonstrated that the canister design is capable of maintaining a 50 psig pressure boundary after drop testing. Based on helium leak testing methods, one test MCO was determined to have a leakage rate not greater than 1x10-5 std cc/sec (prior internal helium presence prevented a more rigorous test) and the remaining test MCO had a measured leakage rate less than 1x10-7 std cc/sec (i.e., a leaktight containment) after the drop test. The effort has also demonstrated the capability of finite element methods using plastic analysis techniques to accurately predict the structural deformations of canisters subjected to an accidental drop event.

  20. Drop jumping. II. The influence of dropping height on the biomechanics of drop jumping

    NARCIS (Netherlands)

    Bobbert, M F; Huijing, P A; van Ingen Schenau, G J

    In the literature, athletes preparing for explosive activities are recommended to include drop jumping in their training programs. For the execution of drop jumps, different techniques and different dropping heights can be used. This study was designed to investigate for the performance of bounce

  1. Regulatory agencies and regulatory risk

    OpenAIRE

    Knieps, Günter; Weiß, Hans-Jörg

    2008-01-01

    The aim of this paper is to show that regulatory risk is due to the discretionary behaviour of regulatory agencies, caused by a too extensive regulatory mandate provided by the legislator. The normative point of reference and a behavioural model of regulatory agencies based on the positive theory of regulation are presented. Regulatory risk with regard to the future behaviour of regulatory agencies is modelled as the consequence of the ex ante uncertainty about the relative influence of inter...

  2. Liquid toroidal drop under uniform electric field

    Science.gov (United States)

    Zabarankin, Michael

    2017-06-01

    The problem of a stationary liquid toroidal drop freely suspended in another fluid and subjected to an electric field uniform at infinity is addressed analytically. Taylor's discriminating function implies that, when the phases have equal viscosities and are assumed to be slightly conducting (leaky dielectrics), a spherical drop is stationary when Q=(2R2+3R+2)/(7R2), where R and Q are ratios of the phases' electric conductivities and dielectric constants, respectively. This condition holds for any electric capillary number, CaE, that defines the ratio of electric stress to surface tension. Pairam and Fernández-Nieves showed experimentally that, in the absence of external forces (CaE=0), a toroidal drop shrinks towards its centre, and, consequently, the drop can be stationary only for some CaE>0. This work finds Q and CaE such that, under the presence of an electric field and with equal viscosities of the phases, a toroidal drop having major radius ρ and volume 4π/3 is qualitatively stationary-the normal velocity of the drop's interface is minute and the interface coincides visually with a streamline. The found Q and CaE depend on R and ρ, and for large ρ, e.g. ρ≥3, they have simple approximations: Q˜(R2+R+1)/(3R2) and CaE∼3 √{3 π ρ / 2 } (6 ln ⁡ρ +2 ln ⁡[96 π ]-9 )/ (12 ln ⁡ρ +4 ln ⁡[96 π ]-17 ) (R+1 ) 2/ (R-1 ) 2.

  3. Investigations of levitated helium drops

    Science.gov (United States)

    Whitaker, Dwight Lawrence

    1999-11-01

    We report on the development of two systems capable of levitating drops of liquid helium. Helium drops of ˜20 mum have been levitated with the radiation pressure from two counter-propagating Nd:YAG laser beams. Drops are produced with a submerged piezoelectric transducer, and could be held for up to three minutes in our optical trap. Calculations show that Brillouin and Raman scattering of the laser light in the liquid helium produces a negligible rate of evaporation of the drop. Evaporation caused by the enhanced vapor pressure of the curved drop surfaces appears to be a significant effect limiting the drop lifetimes. Helium drops as large as 2 cm in diameter have been suspended in the earth's gravitational field with a magnetic field. A commercial superconducting solenoid provides the necessary field, field-gradient product required to levitate the drops. Drops are cooled to 0.5 K with a helium-3 refrigerator, and can be held in the trap indefinitely. We have found that when two or more drops are levitated in the same magnetic trap, the drops often remain in a state of apparent contact without coalescing. This effect is a result of the evaporation of liquid from between the two drops, and is found to occur only for normal fluid drops. We can induce shape oscillations in charged, levitated drops with an applied ac electric field. We have measured the resonance frequencies and damping rates for the l = 2 mode of oscillation as function of temperature. We have also developed a theory to describe the small amplitude shape oscillations of a He II drop surrounded by its saturated vapor. In our theory, we have considered two sets of boundary conditions---one where the drop does not evaporate and another in which the liquid and vapor are in thermodynamic equilibrium. We have found that both solutions give a frequency that agrees well with experiment, but that the data for the damping rate agree better with the solution without evaporation.

  4. Pressure drop in contraction flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz

    This note is a supplement to Dynamic of Polymeric Liquids (DPL) page 178. DPL gives an equation for the pressure drop in a tapered (and circular) contraction, valid only at low angles. Here the general definition of contraction flow (the Bagley correction) and a more general method to find...... the pressure drop in a contraction are given....

  5. Laser impact on a drop

    CERN Document Server

    Klein, Alexander L; Bouwhuis, Wilco; Lhuissier, Henri; Sun, Chao; Snoeijer, Jacco H; Villermaux, Emmanuel; Lohse, Detlef; Gelderblom, Hanneke

    2016-01-01

    The impact of a laser pulse on a highly absorbing liquid drop can lead to a violent response: the drop is accelerated, strongly deforms, and eventually fragments. Shock waves, the ejection of matter, and even plasma formation can accompany this process ...

  6. Gas Pressure-Drop Experiment

    Science.gov (United States)

    Luyben, William L.; Tuzla, Kemal

    2010-01-01

    Most chemical engineering undergraduate laboratories have fluid mechanics experiments in which pressure drops through pipes are measured over a range of Reynolds numbers. The standard fluid is liquid water, which is essentially incompressible. Since density is constant, pressure drop does not depend on the pressure in the pipe. In addition, flow…

  7. A drop in uniaxial and biaxial nonlinear extensional flows

    Science.gov (United States)

    Favelukis, M.

    2017-08-01

    In this theoretical report, we explore small deformations of an initially spherical drop subjected to uniaxial or biaxial nonlinear extensional creeping flows. The problem is governed by the capillary number (Ca), the viscosity ratio (λ), and the nonlinear intensity of the flow (E). When the extensional flow is linear (E = 0), the familiar internal circulations are obtained and the same is true with E > 0, except that the external and internal flow rates increase with increasing E. If E 0) and oblate spheroidal drops for biaxial flows (Ca 0, the drop is more elongated than the linear case, while E 0 tends to facilitate drop breakup, while E < 0 makes drop breakup more difficult.

  8. Design and Certification of Targets for Drop Tests at the NTRC Packaging Research Facility

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, S.B.

    2003-06-05

    This report provides documentation of the design and certification of drop pad (targets) at the National Transportation Research Center (NTRC) Packaging Research Facility(PRF). Based on the evaluation performed, it has been demonstrated that the small (interior) drop pad (target) meets the regulatory definition of a flat, essentially unyielding, horizontal surface for packages weighing up to 3,150 lb (1,432 kg). The large (exterior) drop pad (target) meets the regulatory definition of a flat, essentially unyielding, horizontal surface for packages weighing up to 28,184 lb (12,811 kg).

  9. Drop spreading with random viscosity

    CERN Document Server

    Xu, Feng

    2016-01-01

    We examine theoretically the spreading of a viscous liquid drop over a thin film of uniform thickness, assuming the liquid's viscosity is regulated by the concentration of a solute that is carried passively by the spreading flow. The solute is assumed to be initially heterogeneous, having a spatial distribution with prescribed statistical features. To examine how this variability influences the drop's motion, we investigate spreading in a planar geometry using lubrication theory, combining numerical simulations with asymptotic analysis. We assume diffusion is sufficient to suppress solute concentration gradients across but not along the film. The solute field beneath the bulk of the drop is stretched by the spreading flow, such that the initial solute concentration immediately behind the drop's effective contact lines has a long-lived influence on the spreading rate. Over long periods, solute swept up from the precursor film accumulates in a short region behind the contact line, allowing patches of elevated v...

  10. 45-FOOT HIGH DROP TOWER

    Data.gov (United States)

    Federal Laboratory Consortium — The Drop Tower is used to simulate and measure the impact shocks that are exerted on parachute loads when they hit the ground. It is also used for HSL static lift to...

  11. VTrans Small Culvert Inventory - Drop Inlets

    Data.gov (United States)

    Vermont Center for Geographic Information — Vermont Agency of Transportation Small Culvert Inventory: Drop Inlets. This data contains drop inlets locations along VTrans maintained roadways. The data was...

  12. Drop Spreading with Random Viscosity

    Science.gov (United States)

    Xu, Feng; Jensen, Oliver

    2016-11-01

    Airway mucus acts as a barrier to protect the lung. However as a biological material, its physical properties are known imperfectly and can be spatially heterogeneous. In this study we assess the impact of these uncertainties on the rate of spreading of a drop (representing an inhaled aerosol) over a mucus film. We model the film as Newtonian, having a viscosity that depends linearly on the concentration of a passive solute (a crude proxy for mucin proteins). Given an initial random solute (and hence viscosity) distribution, described as a Gaussian random field with a given correlation structure, we seek to quantify the uncertainties in outcomes as the drop spreads. Using lubrication theory, we describe the spreading of the drop in terms of a system of coupled nonlinear PDEs governing the evolution of film height and the vertically-averaged solute concentration. We perform Monte Carlo simulations to predict the variability in the drop centre location and width (1D) or area (2D). We show how simulation results are well described (at much lower computational cost) by a low-order model using a weak disorder expansion. Our results show for example how variability in the drop location is a non-monotonic function of the solute correlation length increases. Engineering and Physical Sciences Research Council.

  13. Drops, contact lines, and electrowetting

    NARCIS (Netherlands)

    't Mannetje, Dieter

    2013-01-01

    In this work, we study the behaviour of drops and contact lines under the influence of electric fields, and how these can answer fundamental and industrial questions. Our focus is on studying the varying balance of the electric field, hysteresis forces and inertia as the speed of a contact line

  14. Structural concerns in dynamic drop loads on transfer lock mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Pfeiffer, P.A.; Moran, T.J.; Kulak, R.F. [Argonne National Lab., IL (United States). Reactor Engineering Div.

    1997-07-01

    Drop loads are usually low probability events that can generate substantial loading to the impacted structures. When the impacted structure contains slender elements, the concern about dynamic buckling must be addressed. The problem of interest here is a structure is also under significant preload, which must be taken into account in the transient analysis. For complex structures, numerical simulations are the only viable option for assessing the transient response to short duration impactive loads. this paper addresses several analysis issues of preloaded structures with slender members subjected to drop loads. A three-dimensional beam element is validated for use in dynamic buckling analysis. the numerical algorithm used to solve the transient response of preloaded structures is discussed. The methodology is applied to an inter-compartment lock that is under significant preloads, and subjected to a drop load.

  15. An improved technique of eye drop self-administration for patients with limited vision.

    Science.gov (United States)

    Ritch, Robert; Jamal, Karim N; Gürses-Ozden, Rabia; Liebmann, Jeffrey M

    2003-04-01

    To describe a new, highly accurate, tactile technique to increase accuracy in the self-administration of eye drops. Interventional case series. Ten adult patients with loss of fixation (bottle, and location of the drops' landing points on the face or eye were recorded. The patients were then instructed in a new technique for instillation, guided through the procedure once, and allowed to practice until comfortable with it. All measurements were then repeated. In patients with loss of fixation in one eye, an additional 3.2 +/- 4.1 seconds were required to instill a drop using the new technique (P <.0001, paired t test; range, -7-18 seconds). The mean number of drops dispensed decreased by 0.1 +/- 0.6 drops (P =.60, paired t test; range, -2-1 drop). The accuracy of drop placement increased from 80.0% to 82.5% (P =.32, paired t test). In subjects with loss of fixation in both eyes, using the new technique increased the time needed to instill a drop by 3.8 +/- 3.8 seconds (P <.0001, paired t test; range, -3-13 seconds). The average number of drops dispensed decreased by 0.1 +/- 0.6 drops (P =.25, paired t test; range, -2-1 drop). The accuracy of placement increased from 63.0% to 85.0% (P =.001, paired t test). This technique of drop instillation may be beneficial for patients with significant visual impairment in both eyes.

  16. Dancing drops over vibrating substrates

    Science.gov (United States)

    Borcia, Rodica; Borcia, Ion Dan; Helbig, Markus; Meier, Martin; Egbers, Christoph; Bestehorn, Michael

    2017-04-01

    We study the motion of a liquid drop on a solid plate simultaneously submitted to horizontal and vertical harmonic vibrations. The investigation is done via a phase field model earlier developed for describing static and dynamic contact angles. The density field is nearly constant in every bulk region (ρ = 1 in the liquid phase, ρ ≈ 0 in the vapor phase) and varies continuously from one phase to the other with a rapid but smooth variation across the interfaces. Complicated explicit boundary conditions along the interface are avoided and captured implicitly by gradient terms of ρ in the hydrodynamic basic equations. The contact angle θ is controlled through the density at the solid substrate ρ S , a free parameter varying between 0 and 1 [R. Borcia, I.D. Borcia, M. Bestehorn, Phys. Rev. E 78, 066307 (2008)]. We emphasize the swaying and the spreading modes, earlier theoretically identified by Benilov and Billingham via a shallow-water model for drops climbing uphill along an inclined plane oscillating vertically [E.S. Benilov, J. Billingham, J. Fluid Mech. 674, 93 (2011)]. The numerical phase field simulations will be completed by experiments. Some ways to prevent the release of the dancing drops along a hydrophobic surface into the gas atmosphere are also discussed in this paper.

  17. The effect of dropping impact on bruising pomegranate fruit

    Directory of Open Access Journals (Sweden)

    M Mohammad Shafie

    2016-04-01

    Full Text Available Introduction: The pomegranate journey from orchard to supermarket is very complex and pomegranates are subjected to the variety of static and dynamic loads that could result in this damage and bruise occurring. Bruise area and bruise volume are the most important parameters to evaluate fruit damage occurred in harvest and postharvest stages. The bruising is defined as damage to fruit flesh usually with no abrasion of the peel. The two different types of dynamic loading which can physically cause fruit bruising are impact and vibration. The impact and vibration loadings may occur during picking or sorting as the pomegranates are dropped into storage bins and during transportation. The focus of this work was on the impact loading as this appeared to be the most prevalent. In view of the limitations of conventional testing methods (ASTM D3332 Standard Test Methods for Mechanical Shock Fragility of Products, the method and procedure for determining dropping bruise boundary of fruit were also established by adapting free-fall dropping tests. Materials and Methods: After the ‘Malas-e-Saveh’ pomegranates had been selected, they were numbered, and the weight and dimension of each sample were measured and recorded. Firmness in cheek region of each fruit was also measured. Fruit firmness was determined by measuring the maximum force during perforating the sample to a depth of 10 mm at a velocity of 100 mm min-1 with an 8 mm diameter cylindrical penetrometer mounted onto a STM-5 Universal Testing Machine (SANTAM, Design CO. LTD., England. Free-fall dropping tests with a series of drop heights (6, 7, 10, 15, 30 and 60 cm were conducted on fresh ‘Malas-e-Saveh’ pomegranates. Three samples were used for each dropping height, and each sample was subjected to impact on two different positions. Before the test was started, it was necessary to control the sample's drop position. The cheek of sample was placed on the fruit holder. An aluminum plate mounted

  18. Standard test method for conducting drop-weight test to determine nil-ductility transition temperature of ferritic steels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method covers the determination of the nil-ductility transition (NDT) temperature of ferritic steels, 5/8 in. (15.9 mm) and thicker. 1.2 This test method may be used whenever the inquiry, contract, order, or specification states that the steels are subject to fracture toughness requirements as determined by the drop-weight test. 1.3 The values stated in inch-pound units are to be regarded as the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  19. Clinical and regulatory protocol for the treatment of jaundice in adults and elderly subjects: a support for the health care network and regulatory system Protocolo clínico e de regulação para o tratamento de icterícia no adulto e idoso: subsídio para as redes assistenciais e o complexo regulador

    Directory of Open Access Journals (Sweden)

    José Sebastião dos Santos

    2008-01-01

    Full Text Available PURPOSE: Clinical interventions and controlled access to the health care system can be improved by a Regulatory System (RS and Clinical and Regulatory Protocols (CRPs. The objective of the present paper is to present the methodology used for elaborating the CRPs. METHODS: The process used to elaborate the CPRs involved a scientific co-operation between university and health care system. Workshops were held and attended by primary care practitioners, RS team, and matrix team (university specialists supporting primary care practitioners. RESULTS: The treatment of jaundice in adults and elderly subjects is amongst the themes selected for elaborating the CRPs since jaundice is a medical sign frequently seen in four clinical scenarios involving distinctive diagnostic and therapeutic interventions which can be performed in different health care settings. Evaluation guidelines as well as the clinical and regulatory procedures were established for different health care settings. The most relevant clinical and regulatory interventions were expressed as algorithms in order to facilitate the use of CRPs by health care practitioners. CONCLUSION: It is expected that the implementation of this protocol will minimise the imbalance between the icteric patients' needs and the treatment modalities being offered, thus contributing to a more co-operative health care network.OBJETIVO: As ações clínicas e de ordenação do acesso à rede de saúde podem ser aperfeiçoadas pelo Complexo Regulador (CR e pelos Protocolos Clínicos e de Regulação (PCR. Nesse trabalho apresenta-se a metodologia de elaboração dos PCR mediante cooperação entre universidade e sistema de saúde. MÉTODOS: O processo utilizado para a elaboração dos PCR envolve oficinas com a participação de profissionais da atenção básica, do CR e das equipes matriciais (especialistas da universidade que dão suporte às equipes de atenção básica. RESULTADOS: Dentre os temas selecionados

  20. Drag and drop display & builder

    Energy Technology Data Exchange (ETDEWEB)

    Bolshakov, Timofei B.; Petrov, Andrey D.; /Fermilab

    2007-12-01

    The Drag and Drop (DnD) Display & Builder is a component-oriented system that allows users to create visual representations of data received from data acquisition systems. It is an upgrade of a Synoptic Display mechanism used at Fermilab since 2002. Components can be graphically arranged and logically interconnected in the web-startable Project Builder. Projects can be either lightweight AJAX- and SVG-based web pages, or they can be started as Java applications. The new version was initiated as a response to discussions between the LHC Controls Group and Fermilab.

  1. Interfacial Dynamics of Thin Viscoelastic Films and Drops

    CERN Document Server

    Barra, Valeria; Kondic, Lou

    2016-01-01

    We present a computational investigation of thin viscoelastic films and drops on a solid substrate subject to the van der Waals interaction force. The governing equations are obtained within a long-wave approximation of the Navier-Stokes equations with Jeffreys model for viscoelastic stresses. We investigate the effects of viscoelasticity, Newtonian viscosity, and the substrate slippage on the dynamics of thin viscoelastic films. We also study the effects of viscoelasticity on drops that spread or recede on a prewetted substrate. For dewetting films, the numerical results show the presence of multiple secondary droplets for higher values of elasticity, consistently with experimental findings. For drops, we find that elastic effects lead to deviations from the Cox-Voinov law for partially wetting fluids. In general, elastic effects enhance spreading, and suppress retraction, compared to Newtonian ones.

  2. Frictionally induced ignition processes in drop and skid tests

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Peter [Los Alamos National Laboratory; Parker, Gary [Los Alamos National Laboratory; Novak, Alan [Los Alamos National Laboratory

    2010-01-01

    The standard LANL/Pantex drop and skid tests rely on subjective assessment of reaction violence to quantify the response of the charge, and completely miss nonpropagating hot-spot ignition sites. Additionally, large variations in test results have been observed, which we propose is due to a misunderstanding of the basic physical processes that lead to threshold ignition in these tests. The tests have been redesigned to provide control of these mechanisms and to permit direct observation of hot spots at the impact site, allowing us to follow the progression of the outcome as the drop height and ignition source density are varied. The results confirm that frictional interactions between high-melting-point solids are the dominant ignition mechanism, not just at the threshold, but in fact at all realistic drop heights.

  3. Regulatory Anatomy

    DEFF Research Database (Denmark)

    Hoeyer, Klaus

    2015-01-01

    This article proposes the term “safety logics” to understand attempts within the European Union (EU) to harmonize member state legislation to ensure a safe and stable supply of human biological material for transplants and transfusions. With safety logics, I refer to assemblages of discourses, le...... they arise. In short, I expose the regulatory anatomy of the policy landscape....

  4. Drop shaping by laser-pulse impact

    CERN Document Server

    Klein, Alexander L; Visser, Claas Willem; Lhuissier, Henri; Sun, Chao; Snoeijer, Jacco H; Villermaux, Emmanuel; Lohse, Detlef; Gelderblom, Hanneke

    2015-01-01

    We study the hydrodynamic response of a falling drop hit by a laser pulse. Combining high-speed with stroboscopic imaging we report that a millimeter-sized dyed water drop hit by a milli-Joule nanosecond laser-pulse deforms and propels forward at several meters per second, until it eventually fragments. We show that the drop motion results from the recoil momentum imparted at the drop surface by water vaporization. We measure the propulsion speed and the time-deformation law of the drop, complemented by boundary integral simulations. We explain the drop propulsion and shaping in terms of the laser pulse energy and drop surface tension. These findings are crucial for the generation of extreme ultraviolet (EUV) light in lithography machines.

  5. Impact of acute static-stretching on the optimal height in drop jumps

    Directory of Open Access Journals (Sweden)

    Leonardo A. Pasqua

    2014-03-01

    Full Text Available This study analyzed the effect of static stretching on performance during drop jumps. Furthermore, we investigated if a reduction in drop height would compensate the stretching-caused alterations. Ten physically active male subjects performed drop jumps at four different drop heights without static stretching for the optimal drop height determination. After, they performed drop jumps on two drop heights with static stretching previously. The jump height, contact time and reactive strength index were significantly affected by static stretching. However, only the contact time was significantly improved by the reduction in drop height with previous static stretching. Our results suggest that the decrement in performance after static stretching could be partially compensated by a reduction in drop height, which decreases the contact time near a non-stretching jump condition. This can be explained by the lower landing velocity and, possibly, the smaller reduction in the activation of the plantar flexors muscles. In conclusion, the reduction in drop height seems to be interesting after a static stretching session, aiming to expose the athletes to lower impact forces to maintain jump performance.

  6. Deformation and breakup of a non-Newtonian slender drop in an extensional flow: inertial effects and stability

    Science.gov (United States)

    Favelukis, Moshe; Lavrenteva, Olga M.; Nir, Avinoam

    2006-09-01

    We consider the deformation and breakup of a non-Newtonian slender drop in a Newtonian liquid, subject to an axisymmetric extensional flow, and the influence of inertia in the continuous phase. The non-Newtonian fluid inside the drop is described by the simple power-law model and the unsteady deformation of the drop is represented by a single partial differential equation. The steady-state problem is governed by four parameters: the capillary number; the viscosity ratio; the external Reynolds number; and the exponent characterizing the power-law model for the non-Newtonian drop. For Newtonian drops, as inertia increases, drop breakup is facilitated. However, for shear thinning drops, the influence of increasing inertia results first in preventing and then in facilitating drop breakup. Multiple stationary solutions were also found and a stability analysis has been performed in order to distinguish between stable and unstable stationary states.

  7. Micro-explosion of compound drops

    Science.gov (United States)

    Chen, Chun-Kuei; Lin, Ta-Hui

    2014-08-01

    Introducing water into spray combustion systems, by either water-in-oil emulsification or supplementary water injection, is one of the major techniques for combustion improvement and NOx reduction. Plentiful researches are available on combustion of water-in-oil emulsion fuel drops. The emulsified liquid is a heterogeneous mixture of immiscible liquids. One component forms the continuous phase and the other component forms the discrete phase. The discrete phase consists of globules of the one fluid that are suspended in the continuous phase fluid. Water-in-oil emulsions are commonly considered for combustion applications because emulsions can result in micro-explosion, thereby reducing the average drop diameter to enhance liquid vaporization, and suppressing the formation of soot and NOx. However, the water addition generally does not exceed about 20% for smooth engine operations[!, 21. The combustion characteristics and micro-explosion of emulsion drop were studied by many researchers. The micro-explosion of water in fuel emulsion drops was caused by very fast growth of superheated water vapor bubbles, its superheat limits must be lower than the boiling point temperature of the fuel. These bubbles were primarily governed by the pressure difference between the superheated vapor and the liquid, and by the inertia imparted to the liquid by the motion of the bubble surface[3 6 In this study, we used a coaxial nozzle to generation the multi-component drop. The different type of water-in-oil fuel drops called the compound drops. Unlike an emulsion drop, a compound drop consists of a water core and a fuel shell, which can originate from the phase separation of emulsion[7, 81 or a water drop colliding with a fuel drop[9, 101 Burning and micro-explosion of compound drops have been found to be distinct from those of emulsion drops[9-111 Wang et al.[9 , 101 studied the combustion characteristics of collision merged alkane-water drops. The merged drops appeared in adhesive

  8. Planar Microfluidic Drop Splitting and Merging

    Science.gov (United States)

    Collignon, Sean; Friend, James; Yeo, Leslie; MAD-LAB Team

    2015-11-01

    Open drop microfluidic platforms offer attractive alternatives to closed microchannel devices, however, to be effective they require efficient schemes for planar drop transport and manipulation. While there are many methods that have been reported for drop transport, it is far more difficult to carry out drop operations of dispensing, merging and splitting. In this work, we introduce a novel alternative to merge and split drops using laterally-offset modulated surface acoustic waves (SAWs). To do so, the energy delivery into the drop is modulated to induce drop stretching. Upon removal of the SAW energy, capillary forces at the center of the elongated drop drain the capillary bridge region towards both ends, resulting in its collapse and consequential splitting of the drop. This occurs only below a critical Ohnesorge number, a balance between the viscous forces that retard the drainage and the sufficiently large capillary forces that cause the liquid bridge to pinch. By this scheme we show the possibility of both reliable symettric splitting of a drop with an average deviation in droplet volumes of only around 4%, and no greater than 10%, as well as asymmetric splitting, by tuning the input energy to the device--thus presenting a comparable alternative to electrowetting.

  9. Characteristics of Unequal Size Drop Collisions

    Science.gov (United States)

    Kim, Jungyong; Longmire, Ellen; Kim, Man Sik

    2009-11-01

    Pairs of water/glycerin drops were injected into silicone oil and traveled on downward trajectories before colliding. Unequal size drop collisions with drop size ratios (Ds/DL) of 0.7 and 0.5 were investigated. Simultaneous dual-field PIV measurements were obtained to characterize coalescence and rebounding behavior. The initial injection angle and tube height were adjusted to access appropriate impact parameters. In the current study, the collision angle of the large drop was, in general, shallower than that of the small drop, and a range of velocity ratios and impact parameters was examined. Coalescence occurs above We* = 11 similar to collision outcomes for equal size drops. As drop size ratio decreases, the intervening film deforms more. If the velocity ratio uL/us 1, the interface flattens before coalescence. The rupture location varies due to the asymmetry of the drops. As collision offset increases (B > 0), the film rupture time is shortened and mixing of the fluid within the drops is enhanced after coalescence. These results will be compared with the behavior observed previously for equal size drop collisions.

  10. Vertical Drop Test of a Transport Fuselage Section

    OpenAIRE

    熊倉, 郁夫; KUMAKURA, Ikuo

    2002-01-01

    The NAL Structures and Materials Research Center conducted a vertical drop test of a fuselage section from a YS-11A transport airplane in December 2001. This test program is part of research into the structural crashworthiness of transport aircraft in the event of a crash accident, one of the subjects of Aviation Safety and Environmental Compatibility Technology Research(ASET) at NAL. Cooperative research related to this test program has also been carried out by NAL and Kawasaki Heavy Industr...

  11. Footprint Geometry and Sessile Drop Resonance

    Science.gov (United States)

    Chang, Chun-Ti; Daniel, Susan; Steen, Paul H.

    2016-11-01

    How does a sessile drop resonate if its footprint is square (square drop)? In this talk, we discuss the two distinct families of observed modes in our experiments. One family (spherical modes) is identified with the natural modes of capillary spherical caps, and the other (grid modes) with Faraday waves on a square bath (square Faraday waves). A square drop exhibits grid or spherical modes depending on its volume, and the two families of modes arise depending on how wavenumber selection of footprint geometry and capillarity compete. For square drops, a dominant effect of footprint constraint leads to grid modes which are constrained response; otherwise the drops exhibit spherical modes, the characteristic of sessile drops on flat plates. Chun-Ti Chang takes his new position at National Taiwan University on Aug. 15th, 2016. Until then, Chun-Ti Chang is affiliated with Technical University Dortmund, Germany.

  12. Large bubble entrainment in drop impact

    Science.gov (United States)

    Thoraval, Marie-Jean; Li, Yangfan; Thoroddsen, Sigurdur T.

    2015-11-01

    A drop impacting on a pool of the same liquid can entrap air bubbles in many different ways. A peculiar entrapment was observed by Pumphrey and Elmore (1990) and remained unexplained until now. For a small range of parameters, the cavity produced by the impacting drop spreads radially in a dish-shape and then closes to entrap a bubble larger than the drop. We demonstrate that the large bubble is caused by a vortex ring produced in the liquid during the impact of the drop. We combine experiments and numerical simulations to show that the vortex ring pulls on the interface on the side of the cavity to stretch it radially, explaining the shape of the cavity. Only prolate drops are able to generate large bubbles. This is due to the self-destruction of the vortex earlier during the impact for flatter drops.

  13. Star-shaped oscillations of Leidenfrost drops

    Science.gov (United States)

    Ma, Xiaolei; Liétor-Santos, Juan-José; Burton, Justin C.

    2017-03-01

    We experimentally investigate the self-sustained, star-shaped oscillations of Leidenfrost drops. The drops levitate on a cushion of evaporated vapor over a heated, curved surface. We observe modes with n =2 -13 lobes around the drop periphery. We find that the wavelength of the oscillations depends only on the capillary length of the liquid and is independent of the drop radius and substrate temperature. However, the number of observed modes depends sensitively on the liquid viscosity. The dominant frequency of pressure variations in the vapor layer is approximately twice the drop oscillation frequency, consistent with a parametric forcing mechanism. Our results show that the star-shaped oscillations are driven by capillary waves of a characteristic wavelength beneath the drop and that the waves are generated by a large shear stress at the liquid-vapor interface.

  14. Investigation of drop coalescence using tomographic PIV

    Science.gov (United States)

    Ortiz-Duenas, Cecilia; Kim, Jungyong; Longmire, Ellen

    2008-11-01

    High-speed tomographic PIV was used to obtain evolving volumetric velocity fields of the coalescence of single drops and two side-by-side drops through liquid/liquid interfaces. Reynolds numbers (Re=ρsUσD/μs) based on surface tension velocity (Uσ=D/tσ) and surrounding ambient fluid were 8-10, and the viscosity ratio between the fluid drop and surrounding fluid was 0.14. The coalescence process investigated is driven by gravity and thus the initial drops are non-spherical and the interface is deformed by the drops. Previously, Mohamed-Kassim & Longmire (2004) showed that under these conditions, the film rupture typically occurs off-axis, and therefore the flow is three-dimensional. For a single drop, volumetric velocity vector fields are used to characterize the asymmetric film rupture occurring for 0drop into a vortex ring are relatively axisymmetric. For two side-by-side drops, the first drop to coalesce ruptures off-axis on the side closest to the second drop. The volumetric velocity and vorticity fields indicate an asymmetric collapse of the drop for 0.1drop while the capillary waves are axisymmetric.

  15. Chaos in a Water Drop.

    Science.gov (United States)

    Schneider, Scott Dudley

    Nature is chaotic. It appears to be more disorderly and random than orderly and regular. The path of a leaf in a rocky stream can appear as complex as the smoke from a cigarette or the outline of a cloud. In trying to model the path of a leaf in a rocky stream, the dynamical equations become rapidly complicated. A branch of scientific analysis know as Chaos has sprung up in the last few decades with techniques that can be applied to most of the physical sciences in an attempt to describe or categorize the various non-linear phenomena found in Nature. The aim of this paper is to provide an introduction to the study of chaotic behavior, with an emphasis on the potential teaching possibilities contained in some of the analysis. An appropriate beginning would be motion that is regular and "easy" to understand--stable motion. Along the way, various graphical representations will be developed that enable a clear viewing of the motion of the system under study. Next, the Logistic model will be used to gain an understanding of the nature of chaos; it is very comprehensive in representing the characteristics of chaos that will be studied in other systems. Another system studied is the three-dimensional Rossler model. In the study of the "dripping faucet", a time series of the periods between drips of water is recorded. Various techniques (collected from the introductory systems) are applied in an attempt to model the mechanism behind the water drops, or at least to characterize the graphical "animals" that we find. The water drop "attractor" is found to be chaotic, exhibiting many of the chaotic characteristics seen in other models. It is hoped that this work can be used as a primer for those students beginning a journey into Chaos, or as a reference tool for those already familiar with the topics enclosed. Many areas in this work were touched lightly; there is a rich un-tapped complexity still waiting future study. The waters here have only begun to be charted.

  16. Drops moving along and across a filament

    Science.gov (United States)

    Sahu, Rakesh P.; Sinha-Ray, Suman; Yarin, Alexander; Pourdeyhimi, Behnam

    2013-11-01

    The present work is devoted to the experimental study of oil drop motion both along and across a filament due to the air jet blowing. In case of drop moving along the filament, phenomena such as drop stick-slip motion, shape oscillations, shedding of a tail along the filament, the tail capillary instability and drop recoil motion were observed which were rationalized in the framework of simplified models. Experiments with cross-flow of the surrounding gas relative to the filament with an oil drop on it were conducted, with air velocity in the range of 7.23 to 22.7 m s-1. The Weber number varied from 2 to 40 and the Ohnesorge number varied from 0.07 to 0.8. The lower and upper critical Weber numbers were introduced to distinguish between the beginning of the drop blowing off the filament and the onset of the bag-stamen breakup. The range of the Weber number between these two critical values is filled with three types of vibrational breakup: V1 (a balloon-like drop being blown off), V2 (a drop on a single stamen being blown off), and V3 (a drop on a double stamen being blown off). The Weber number/Ohnesorge number plane was delineated into domains of different breakup regimes. The work is supported by the Nonwovens Cooperative Research Center (NCRC).

  17. Cooperative breakups induced by drop-to-drop interactions in one-dimensional flows of drops against micro-obstacles.

    Science.gov (United States)

    Schmit, Alexandre; Salkin, Louis; Courbin, Laurent; Panizza, Pascal

    2015-03-28

    Depending on the capillary number at play and the parameters of the flow geometry, a drop may or may not break when colliding with an obstacle in a microdevice. Modeling the flow of one-dimensional trains of monodisperse drops impacting a micro-obstacle, we show numerically that complex dynamics may arise through drop-to-drop hydrodynamic interactions: we observe sequences of breakup events in which the size of the daughter drops created upon breaking mother ones becomes a periodic function of time. We demonstrate the existence of numerous bifurcations between periodic breakup regimes and we establish diagrams mapping the possible breakup dynamics as a function of the governing (physicochemical, hydrodynamic, and geometric) parameters. Microfluidic experiments validate our model as they concur very well with predictions.

  18. Karakteristik Penderita Drop out Pengobatan Tuberkulosis Paru di Garut

    Directory of Open Access Journals (Sweden)

    Nevi Nurkomarasari

    2014-02-01

    Observed Treatment Short course Chemotherapy (DOTS recomended by World Health Organization has been used, the drop out cases is still high. This study aim was to describe factors contributing to drop out cases in Sukamerang Health Center, Garut during year 2011. This was a cross sectional study using standard questionairres based on Ministry of Health Tuberculosis handbook. Subjects were all , 30  drop out patients during medication at Sukamerang Health Center. Statistical Programee for social science (SPSS version 17 was used to analize the result. The study results showed  that majority of drop out cases were male less than 35 years old with junior high school education and monthly earning of less than IDR 800.000. Knowledge of TB and attitude towards medication were not satisfactory although the role of pengawas minum obat (PMO was quite good. The results showed that the problem was heightened by their difficulty to access the health services. The important aspect in the treatment of tuberculosis is determining how to motivate people to complete the treatment in accordance with the established regiment. To achieve that, various pulmonary TB control programs needs to be enhanced to assist pulmonary TB patients. Key words: Drop out, knowledge and attitude, tuberculosis (TB

  19. Association of variants in the sterol regulatory element-binding factor 1 (SREBF1) gene with type 2 diabetes, glycemia, and insulin resistance: a study of 15,734 Danish subjects

    DEFF Research Database (Denmark)

    Grarup, Niels; Stender-Petersen, Kirstine L; Andersson, Ehm A

    2008-01-01

    OBJECTIVE: We evaluated the association of variants in the sterol regulatory element-binding factor 1 gene (SREBF1) with type 2 diabetes. Due to the previous inconclusive quantitative trait associations, we also did studies of intermediate quantitative phenotypes. RESEARCH DESIGN AND METHODS: We ...

  20. Optimization of fall height setting for drop weight tested polypropylene

    Directory of Open Access Journals (Sweden)

    Hylova Lenka

    2017-01-01

    Full Text Available This study deals with polypropylene (PP which was subjected the drop-weight test. PP is a semicrystalline thermoplastic polymer which is commonly used in many indoor applications and also in the automotive industry in the car interiors. The injection moulded PP samples were subjected the penetration test at different fall heights and the results were subsequently evaluated and discussed. It was found out that the fall heights from 100 to 230 J are suitable for PP penetration, but the optimal one is 100 J. Higher heights are not needed because of increasing power consumption of the test device.

  1. Many Drops Make a Lake

    Directory of Open Access Journals (Sweden)

    Chaitanya S. Mudgal

    2014-03-01

    greater knowledge, better skills and disseminate this knowledge through this journal to influence as many physicians and their patients as possible. They have taken the knowledge of their teachers, recognized their giants and are now poised to see further than ever before. My grandmother often used to quote to me a proverb from India, which when translated literally means “Many drops make a lake”. I cannot help but be amazed by the striking similarities between the words of Newton and this Indian saying. Therefore, while it may seem intuitive, I think it must be stated that it is vital for the betterment of all our patients that we recognize our own personal lakes to put our drops of knowledge into. More important is that we recognize that it is incumbent upon each and every one of us to contribute to our collective lakes of knowledge such as ABJS. And finally and perhaps most importantly we need to be utterly cognizant of never letting such lakes of knowledge run dry.... ever.

  2. Head-dropping mechanism in traffic control

    Science.gov (United States)

    Liu, Xintong; Yang, Oliver W.

    2004-09-01

    In this paper, we investigate the application of the head dropping policy as a partial solution to the problem of queue oscillation encountered by RED and its variants. With this method, instead of the tail dropping, which is currently used by RED and many other AQM schemes, the TCP source can be informed of the congestion occurring in the bottleneck router a time period earlier. Specifically, that is a time period of the queuing delay. We have compared DH-RED (drop head RED) and DH-BLUE (drop head BLUE) with the current RED and BLUE in a variety of situations and found that the performances such as the queue size stability as well as packet drop rate can be greatly improved.

  3. Ferrofluid drops in rotating magnetic fields

    CERN Document Server

    Lebedev, A V; Morozov, K I; Bauke, H

    2003-01-01

    Drops of a ferrofluid floating in a non-magnetic liquid of the same density and spun by a rotating magnetic field are investigated experimentally and theoretically. The parameters for the experiment are chosen such that different stationary drop shapes including non-axis-symmetric configurations could be observed. Within an approximate theoretical analysis the character of the occurring shape bifurcations, the different stationary drop forms, as well as the slow rotational motion of the drop is investigated. The results are in qualitative, and often quantitative agreement, with the experimental findings. It is also shown that a small eccentricity of the rotating field may have a substantial impact on the rotational motion of the drop.

  4. Axisymmetric Drop Shape Analysis (ADSA): An Outline.

    Science.gov (United States)

    Saad, Sameh M I; Neumann, A Wilhelm

    2016-12-01

    Drop shape techniques for the measurement of interfacial tension are powerful, versatile and flexible. The shape of the drop/bubble depends on the balance between surface tension and external forces, e.g. gravity. This balance is reflected mathematically in the Laplace equation of capillarity. Axisymmetric Drop Shape Analysis (ADSA) is a commonly used drop shape technique. A streamlined version of the development of ADSA over the past several decades is presented to illustrate its validity and range of utility. Several configurations of interest will be considered and presented systematically. Shape and surface tension will be linked to a shape parameter based on proper concepts of differential geometry. The resulting shape parameter will be shown to allow determination of the range of applicability of such a drop shape method. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Regulatory Physiology

    Science.gov (United States)

    Lane, Helen W.; Whitson, Peggy A.; Putcha, Lakshmi; Baker, Ellen; Smith, Scott M.; Stewart, Karen; Gretebeck, Randall; Nimmagudda, R. R.; Schoeller, Dale A.; Davis-Street, Janis

    1999-01-01

    As noted elsewhere in this report, a central goal of the Extended Duration Orbiter Medical Project (EDOMP) was to ensure that cardiovascular and muscle function were adequate to perform an emergency egress after 16 days of spaceflight. The goals of the Regulatory Physiology component of the EDOMP were to identify and subsequently ameliorate those biochemical and nutritional factors that deplete physiological reserves or increase risk for disease, and to facilitate the development of effective muscle, exercise, and cardiovascular countermeasures. The component investigations designed to meet these goals focused on biochemical and physiological aspects of nutrition and metabolism, the risk of renal (kidney) stone formation, gastrointestinal function, and sleep in space. Investigations involved both ground-based protocols to validate proposed methods and flight studies to test those methods. Two hardware tests were also completed.

  6. Regulatory Benchmarking

    DEFF Research Database (Denmark)

    Agrell, Per J.; Bogetoft, Peter

    2017-01-01

    Benchmarking methods, and in particular Data Envelopment Analysis (DEA), have become well-established and informative tools for economic regulation. DEA is now routinely used by European regulators to set reasonable revenue caps for energy transmission and distribution system operators. The appli......Benchmarking methods, and in particular Data Envelopment Analysis (DEA), have become well-established and informative tools for economic regulation. DEA is now routinely used by European regulators to set reasonable revenue caps for energy transmission and distribution system operators....... The application of bench-marking in regulation, however, requires specific steps in terms of data validation, model specification and outlier detection that are not systematically documented in open publications, leading to discussions about regulatory stability and economic feasibility of these techniques...

  7. Regulatory Benchmarking

    DEFF Research Database (Denmark)

    Agrell, Per J.; Bogetoft, Peter

    2017-01-01

    Benchmarking methods, and in particular Data Envelopment Analysis (DEA), have become well-established and informative tools for economic regulation. DEA is now routinely used by European regulators to set reasonable revenue caps for energy transmission and distribution system operators. The appli......Benchmarking methods, and in particular Data Envelopment Analysis (DEA), have become well-established and informative tools for economic regulation. DEA is now routinely used by European regulators to set reasonable revenue caps for energy transmission and distribution system operators....... The application of benchmarking in regulation, however, requires specific steps in terms of data validation, model specification and outlier detection that are not systematically documented in open publications, leading to discussions about regulatory stability and economic feasibility of these techniques...

  8. The drop height determines neuromuscular adaptations and changes in jump performance in stretch-shortening cycle training

    OpenAIRE

    Taube, Wolfgang; Leukel, Christian; Lauber, B.; Gollhofer, Albert

    2012-01-01

    There is an ongoing discussion about how to improve jump performance most efficiently with plyometric training. It has been proposed that drop height influences the outcome, although longitudinal studies are missing. Based on cross-sectional drop jump studies showing height-dependent Hoffmann (H)-reflex activities, we hypothesized that the drop height should influence the neuromuscular activity and thus, the training result. Thirty-three subjects participated as a control or in one of two str...

  9. Effect of recombinant human epidermal growth factor eye drops and deproteinized calf blood extract eye drops on corneal edema after phacoemulsification

    Directory of Open Access Journals (Sweden)

    Jia Wang

    2017-08-01

    Full Text Available AIM:To compare the effect of recombinant human epidermal growth factor eye drops and deproteinized calf blood extract eye drops on corneal edema after phacoemulsification. METHODS:Totally 72 cases(72 eyesof patients undergoing phacoemulsification were selected and divided into the observation group and the control group by random number table method. After surgery, the observation group were treated with deproteinized calf blood extract eye drops while the control group were treated with recombinant human epidermal growth factor eye drops. The degree of corneal edema, subjective symptom score, corneal endothelium count, changes of corneal thickness and postoperative visual acuity recovery were compared between the two groups at different time points after surgery. RESULTS:Corneal edema in the two groups was significantly milder at 1wk after surgery than that on the 1st day after surgery(PP>0.05. Compared with 1d after surgery, the subjective symptom score and corneal thickness of the two groups significantly decreased on the 7th day after surgery(PPPCONCLUSION:Both of recombinant human epidermal growth factor eye drops and deproteinized calf blood extract eye drops can significantly relieve corneal edema and improve visual acuity of patients after phacoemulsification. However, the latter has obvious advantages over the former in the repair of corneal endothelial cell injury after surgery.

  10. Development of Active Learning Curriculum for CASPER's Microgravity Drop Tower

    Science.gov (United States)

    Carmona-Reyes, Jorge; Wang, Li; York, Judy; Matthews, Lorin; Laufer, Rene; Cook, Mike; Schmoke, Jimmy; Hyde, Truell

    2016-10-01

    As CASPER's new drop tower comes on line, plans for correlated educational research curricula are underway. CASPER's educational research team is working on developing curricula specific to the CASPER drop tower, modeled on a contest currently in use by (BEST) Robotics Inc. within central Texas independent school districts. The curricula integrates age specific use of computer programming software packages such as ``Scratch'' with industry standard communication protocols and augmented reality applications. Content is constructed around an earth and space science framework, covering subjects such as stars and galaxies, matter and energy, fusion and fission at a middle school level. CASPER faculty are partnering with the Region 12 Service Center; this combination provides a wide range of expertise that includes professional development, pedagogical methods, computational thinking in addition to microgravity and space science research expertise. The details of this work will be presented and samples of the manner in which it is impacting the CASPER research and educational outreach partnership will be discussed.

  11. The Drop Tower Bremen -An Overview

    Science.gov (United States)

    von Kampen, Peter; Könemann, Thorben; Rath, Hans J.

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University of Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of ZARM`s drop tower began. Since its inau-guration in September 1990, the eye-catching Drop Tower Bremen with a height of 146m and its characteristic glass roof has become twice a landmark on the campus of the University of Bremen and the emblem of the technology park Bremen. As such an outstanding symbol of space science in Bremen the drop tower provides an european unique facility for experiments under conditions of high-quality weightlessness with residual gravitational accelerations in the microgravity regime. The period of maximum 4.74s of each freely falling experiment at the Drop Tower Bremen is only limited by the height of the drop tower vacuum tube, which was fully manufactured of steal and enclosed by an outer concrete shell. Thus, the pure free fall height of each microgravity drop experiment is approximately 110m. By using the later in-stalled catapult system established in 2004 ZARM`s short-term microgravity laboratory is able to nearly double the time of free fall. This world-wide inimitable capsule catapult system meets scientists` demand of extending the period of weightlessness. During the catapult operation the experiment capsule performs a vertical parabolic flight within the drop tower vacuum tube. In this way the time of microgravity can be extended to slightly over 9s. Either in the drop or in the catapult operation routine the repetition rates of microgravity experiments at ZARM`s drop tower facility are the same, generally up to 3 times per day. In comparison to orbital platforms the ground-based laboratory Drop Tower Bremen represents an economic alternative with a permanent access to weightlessness on earth. Moreover, the exceptional high quality of weightlessness in order of 1e-6 g (in the frequency range below 100

  12. Investigation of drop motion through circular orifices

    Science.gov (United States)

    Bordoloi, Ankur; Longmire, Ellen; Kong, Xiangzhao; Saar, Martin

    2011-11-01

    The motion of drops though porous media occurs in numerous science and engineering fields including multiphase fluid flow in the subsurface during groundwater flow, geothermal energy recovery, and geologic carbon dioxide sequestration. Here, we simplify the porous medium to a thin plate with an orifice to study the interactions between the drop and the solid medium. Drops of water/glycerin with diameter, D, are released in a tank of silicone oil with matched refractive index and allowed to fall downward by gravity. After reaching terminal speed, the drops encounter a thin plate with orifice diameter, d, placed horizontally within the surrounding tank. Drop deformation, contact with the orifice, and breakage are investigated using high-speed imaging, and velocity fields are determined by particle image velocimetry (PIV). Effects of diameter ratio d/D, drop Reynolds number, and drop offset with respect to the orifice center are examined. The experimental results are compared to results from numerical simulations using an immiscible, two-color BGK lattice-Boltzmann method performed under similar test conditions. Supported by DOE (DOE EERE-PMC-10EE0002764).

  13. Drop impact splashing and air entrapment

    KAUST Repository

    Thoraval, Marie-Jean

    2013-03-01

    Drop impact is a canonical problem in fluid mechanics, with numerous applications in industrial as well as natural phenomena. The extremely simple initial configuration of the experiment can produce a very large variety of fast and complex dynamics. Scientific progress was made in parallel with major improvements in imaging and computational technologies. Most recently, high-speed imaging video cameras have opened the exploration of new phenomena occurring at the micro-second scale, and parallel computing allowed realistic direct numerical simulations of drop impacts. We combine these tools to bring a new understanding of two fundamental aspects of drop impacts: splashing and air entrapment. The early dynamics of a drop impacting on a liquid pool at high velocity produces an ejecta sheet, emerging horizontally in the neck between the drop and the pool. We show how the interaction of this thin liquid sheet with the air, the drop or the pool, can produce micro-droplets and bubble rings. Then we detail how the breakup of the air film stretched between the drop and the pool for lower impact velocities can produce a myriad of micro-bubbles.

  14. "Self-Shaping" of Multicomponent Drops.

    Science.gov (United States)

    Cholakova, Diana; Valkova, Zhulieta; Tcholakova, Slavka; Denkov, Nikolai; Smoukov, Stoyan K

    2017-06-13

    In our recent study we showed that single-component emulsion drops, stabilized by proper surfactants, can spontaneously break symmetry and transform into various polygonal shapes during cooling [ Denkov Nature 2015 , 528 , 392 - 395 ]. This process involves the formation of a plastic rotator phase of self-assembled oil molecules beneath the drop surface. The plastic phase spontaneously forms a frame of plastic rods at the oil drop perimeter which supports the polygonal shapes. However, most of the common substances used in industry appear as mixtures of molecules rather than pure substances. Here we present a systematic study of the ability of multicomponent emulsion drops to deform upon cooling. The observed trends can be summarized as follows: (1) The general drop-shape evolution for multicomponent drops during cooling is the same as with single-component drops; however, some additional shapes are observed. (2) Preservation of the particle shape upon freezing is possible for alkane mixtures with chain length difference Δn ≤ 4; for greater Δn, phase separation within the droplet is observed. (3) Multicomponent particles prepared from alkanes with Δn ≤ 4 plastify upon cooling due to the formation of a bulk rotator phase within the particles. (4) If a compound, which cannot induce self-shaping when pure, is mixed with a certain amount of a compound which induces self-shaping, then drops prepared from this mixture can also self-shape upon cooling. (5) Self-emulsification phenomena are also observed for multicomponent drops. In addition to the three recently reported mechanisms of self-emulsification [ Tcholakova Nat. Commun. 2017 , ( 8 ), 15012 ], a new (fourth) mechanism is observed upon freezing for alkane mixtures with Δn > 4. It involves disintegration of the particles due to a phase separation of alkanes upon freezing.

  15. Spinal shrinkage in unloaded and loaded drop-jumping.

    Science.gov (United States)

    Fowler, N E; Lees, A; Reilly, T

    1994-01-01

    Plyometric activities, engaging the muscle in a stretch-shortening cycle, are widely used in athletic training. One such plyometric exercise is drop-jumping, where the athlete drops from a raised platform and immediately on landing performs a maximal vertical jump. These actions are also performed with the athlete externally loaded by the addition of weights to provide greater resistance. Exercises which involve repeated impacts have been shown to give rise to a loss of stature (shrinkage) which can be measured by means of a sensitive stadiometer. This study examined the shrinkage induced by unloaded and loaded drop-jumping from a height of 26 cm. Eight male subjects, aged 20-24 years, performed the test protocol three times, at the same time of day on each occasion. Fifty drop-jumps from a height of 26 cm were performed with no additional load and with a load of 8.5 kg carried in a weighted vest. The third condition was a standing trial where the subject stood for 10 min (the time taken to perform the jumps) wearing the weighted vest. Stature was measured before exercise, immediately after exercise and after a 20 min standing recovery. On a separate occasion the regimen was performed and the vertical reaction force was measured using a Kistler force platform. The mean change in stature for the two jump conditions showed shrinkages of 0.62 (+/- 0.43) mm for unloaded and 2.14 (+/- 1.56) mm for the loaded (p < 0.05). The variance in shrinkage was greater in the loaded case compared to the unloaded condition (p < 0.05) indicating a wider range of jumping strategies.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. 76 FR 40144 - Semiannual Regulatory Agenda

    Science.gov (United States)

    2011-07-07

    ... Certifications Application (ORCA) now collects this data centrally from interested A&E vendors at the time they... learning (i.e., HBCUs/MIs). This is a significant regulatory action and, therefore, was subject to review...

  17. Improvement in the signs and symptoms of dry eye disease with dobesilate eye drops

    OpenAIRE

    Cuevas, Pedro; Outeiri?o, Luis Antonio; Azanza, Carlos; Angulo, Javier; Gim?nez-Gallego, Guillermo

    2015-01-01

    Background Dry eye is a multifactor disease of the tear film and ocular surface that substantially affects quality of life. Case presentation Dobesilate administered as eye drops was well tolerated and effective in treating both the objective signs and subjective symptoms of dry eye disease in this 2-week study. Conclusion To the best of our knowledge, this is the first clinical report of using dobesilate in eye drops. Dobesilate may provide a novel approach to treating drying diseases of the...

  18. Improvement in the signs and symptoms of dry eye disease with dobesilate eye drops.

    Science.gov (United States)

    Cuevas, Pedro; Outeiriño, Luis Antonio; Azanza, Carlos; Angulo, Javier; Giménez-Gallego, Guillermo

    2015-01-01

    Dry eye is a multifactor disease of the tear film and ocular surface that substantially affects quality of life. Dobesilate administered as eye drops was well tolerated and effective in treating both the objective signs and subjective symptoms of dry eye disease in this 2-week study. To the best of our knowledge, this is the first clinical report of using dobesilate in eye drops. Dobesilate may provide a novel approach to treating drying diseases of the eye.

  19. Marangoni induced force on a drop in a Hele Shaw cell

    OpenAIRE

    Gallaire, François; Meliga, Philippe; Laure, Patrice; Baroud, Charles N.

    2014-01-01

    International audience; We analyse the force balance on a cylindrical drop in a Hele-Shaw cell, subjected to a Marangoni flow caused by a surface tension gradient. Depth-averaged Stokes equations, called Brinkman equations, are introduced and a general closed form solution is obtained. The validity of the averaging procedure is ascertained by considering a linear surface tension gradient acting on a cylindrical flattened drop. The Marangoni-driven flow field and resulting force predicted by t...

  20. Micro-splashing by drop impacts

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2012-07-18

    We use ultra-high-speed video imaging to observe directly the earliest onset of prompt splashing when a drop impacts onto a smooth solid surface. We capture the start of the ejecta sheet travelling along the solid substrate and show how it breaks up immediately upon emergence from the underneath the drop. The resulting micro-droplets are much smaller and faster than previously reported and may have gone unobserved owing to their very small size and rapid ejection velocities, which approach 100 m s-1, for typical impact conditions of large rain drops. We propose a phenomenological mechanism which predicts the velocity and size distribution of the resulting microdroplets. We also observe azimuthal undulations which may help promote the earliest breakup of the ejecta. This instability occurs in the cusp in the free surface where the drop surface meets the radially ejected liquid sheet. © 2012 Cambridge University Press.

  1. Blood drop patterns: Formation and applications.

    Science.gov (United States)

    Chen, Ruoyang; Zhang, Liyuan; Zang, Duyang; Shen, Wei

    2016-05-01

    The drying of a drop of blood or plasma on a solid substrate leads to the formation of interesting and complex patterns. Inter- and intra-cellular and macromolecular interactions in the drying plasma or blood drop are responsible for the final morphologies of the dried patterns. Changes in these cellular and macromolecular components in blood caused by diseases have been suspected to cause changes in the dried drop patterns of plasma and whole blood, which could be used as simple diagnostic tools to identify the health of humans and livestock. However, complex physicochemical driving forces involved in the pattern formation are not fully understood. This review focuses on the scientific development in microscopic observations and pattern interpretation of dried plasma and whole blood samples, as well as the diagnostic applications of pattern analysis. Dried drop patterns of plasma consist of intricate visible cracks in the outer region and fine structures in the central region, which are mainly influenced by the presence and concentration of inorganic salts and proteins during drying. The shrinkage of macromolecular gel and its adhesion to the substrate surface have been thought to be responsible for the formation of the cracks. Dried drop patterns of whole blood have three characteristic zones; their formation as functions of drying time has been reported in the literature. Some research works have applied engineering treatment to the evaporation process of whole blood samples. The sensitivities of the resultant patterns to the relative humidity of the environment, the wettability of the substrates, and the size of the drop have been reported. These research works shed light on the mechanisms of spreading, evaporation, gelation, and crack formation of the blood drops on solid substrates, as well as on the potential applications of dried drop patterns of plasma and whole blood in diagnosis. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  2. Drop Performance Test of CRDMs for JRTR

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Myoung-Hwan; Cho, Yeong-Garp; Chung, Jong-Ha [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Jung-Hyun [POSCO Plandtec Co. Ltd, Ulsan (Korea, Republic of); Lee, Kwan-Hee [RIST, Pohang (Korea, Republic of)

    2015-10-15

    The drop test results of CRDMs with AC-type electromagnet show that the initial delay times are not satisfied with the requirement, 0.15 seconds. After the replacement of the electromagnet from AC-type to DCtype, the drop times of CARs and accelerations due to the impact of moving parts are satisfied with all requirements. As a result, it is found that four CRDMs to be installed at site have a good drop performance, and meet all performance requirements. A control rod drive mechanism (CRDM) is a device to control the position of a control absorber rod (CAR) in the core by using a stepping motor which is commanded by the reactor regulating system (RRS) to control the reactivity during the normal operation of the reactor. The top-mounted CRDM driven by the stepping motor for Jordan Research and Training Reactor (JRTR) has been developed in KAERI. The CRDM for JRTR has been optimized by the design improvement based on that of the HANARO. It is necessary to verify the performances such as the stepping, drop, endurance, vibration, seismic and structural integrity for active components. Especially, the CAR drop curves are important data for the safety analysis. This paper describes the test results to demonstrate the drop performances of a prototype and 4 CRDMs to be installed at site. The tests are carried out at a test rig simulating the actual reactor's conditions.

  3. The Drop Tower Bremen -Experiment Operation

    Science.gov (United States)

    Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

    The idea behind the drop tower facility of the Center of Applied Space Technology and Micro-gravity (ZARM) in Bremen is to provide an inimitable technical opportunity of a daily access to short-term weightlessness on earth. In this way ZARM`s european unique ground-based microgravity laboratory displays an excellent economic alternative for research in space-related conditions at low costs comparable to orbital platforms. Many national and international ex-perimentalists motivated by these prospects decide to benefit from the high-quality and easy accessible microgravity environment only provided by the Drop Tower Bremen. Corresponding experiments in reduced gravity could open new perspectives of investigation methods and give scientists an impressive potential for a future technology and multidisciplinary applications on different research fields like Fundamental Physics, Astrophysics, Fluid Dynamics, Combus-tion, Material Science, Chemistry and Biology. Generally, realizing microgravity experiments at ZARM`s drop tower facility meet new requirements of the experimental hardware and may lead to some technical constraints in the setups. In any case the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH) maintaining the drop tower facility is prepared to as-sist experimentalists by offering own air-conditioned laboratories, clean rooms, workshops and consulting engineers, as well as scientific personal. Furthermore, ZARM`s on-site apartment can be used for accommodations during the experiment campaigns. In terms of approaching drop tower experimenting, consulting of experimentalists is mandatory to successfully accomplish the pursued drop or catapult capsule experiment. For this purpose there will be a lot of expertise and help given by ZARM FAB mbH in strong cooperation to-gether with the experimentalists. However, in comparison to standard laboratory setups the drop or catapult capsule setup seems to be completely different at first view. While defining a

  4. [Optimize dropping process of Ginkgo biloba dropping pills by using design space approach].

    Science.gov (United States)

    Shen, Ji-Chen; Wang, Qing-Qing; Chen, An; Pan, Fang-Lai; Gong, Xing-Chu; Qu, Hai-Bin

    2017-07-01

    In this paper, a design space approach was applied to optimize the dropping process of Ginkgo biloba dropping pills. Firstly, potential critical process parameters and potential process critical quality attributes were determined through literature research and pre-experiments. Secondly, experiments were carried out according to Box-Behnken design. Then the critical process parameters and critical quality attributes were determined based on the experimental results. Thirdly, second-order polynomial models were used to describe the quantitative relationships between critical process parameters and critical quality attributes. Finally, a probability-based design space was calculated and verified. The verification results showed that efficient production of Ginkgo biloba dropping pills can be guaranteed by operating within the design space parameters. The recommended operation ranges for the critical dropping process parameters of Ginkgo biloba dropping pills were as follows: dropping distance of 5.5-6.7 cm, and dropping speed of 59-60 drops per minute, providing a reference for industrial production of Ginkgo biloba dropping pills. Copyright© by the Chinese Pharmaceutical Association.

  5. Analysis technology in the thick plate free drop impact, heat and thermal stress of the cask for radioactive material transport

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dew Hey [Korea Institute of Nuclear and Safety, Taejon (Korea, Republic of); Lee, Young Shin; Ryu, Chung Hyun; Kim, Hyun Su; Choi, Kyung Joo; Choi, Young Jin; Lee, Jae Hyung; Na, Jae Yun; Kim, Seong Jong [Chungnam National Univ., Taejon (Korea, Republic of)

    2002-03-15

    In this study, The regulatory condition and analysis condition is analyzed for thick plate free drop, heat and thermal stress analysis to develop the safety assessment technology. Analysis is performed with finite element method which is one of the many analysis methods of the shipping cask. ANSYS, LS-DYNA3D and ABAQUS is suitable for thick plate free drop, heat and thermal stress analysis of the shipping cask. For the analysis model, the KSC-4 that is the shipping cask to transport spent nuclear fuel is investigated. The results of both LS-DYNA3D and ABAQUS for thick plate free drop and the results of ANSYS, LS-DYNA3D and ABAQUS for heat and thermal stress analysis is completely corresponded. And the integrity of the shipping cask is verified. Using this study, the reliable safety assessment technology is supplied to the staff. The efficient and reliable regulatory tasks is performed using the standard safety assessment technology.

  6. Gender, Success, and Drop-Out during a Resistance Exercise Program in Community Dwelling Old Adults

    Directory of Open Access Journals (Sweden)

    O. G. Geirsdottir

    2017-01-01

    Full Text Available Background. Resistance exercise training can be effective against sarcopenia. We identified predictors of drop-out and compared physical outcomes between men and women after such training. Methods. Subjects (N=236, 73.7±5.7 years participated in a 12-week resistance exercise program. Outcome variables were measured at baseline and endpoint. Results. Drop-out was 11.9% and not significantly different between genders. Drop-outs were significantly older and had poorer strength and physical function in comparison to completers. Anthropometrics, QoL, and cognitive function were not related to drop-out. According to multivariate analysis, gait speed and physical activity were the strongest predictors of drop-out. After the training, gains in lean mass or appendicular muscle were significantly higher in men than women; however relative gains in appendicular muscle as well as absolute improvements in strength and function were similar in men and women, respectively. Conclusions. Participants who drop out are older, have poorer physical function, and are less physically active. Old women do not drop out more frequently than men and show meaningful improvements in relevant outcomes similar to men after such a training program. The trial is registered at the US National Library of Medicine (NCT01074879.

  7. Cavity optomechanics in a levitated helium drop

    Science.gov (United States)

    Childress, L.; Schmidt, M. P.; Kashkanova, A. D.; Brown, C. D.; Harris, G. I.; Aiello, A.; Marquardt, F.; Harris, J. G. E.

    2017-12-01

    We describe a proposal for a type of optomechanical system based on a drop of liquid helium that is magnetically levitated in vacuum. In the proposed device, the drop would serve three roles: its optical whispering-gallery modes would provide the optical cavity, its surface vibrations would constitute the mechanical element, and evaporation of He atoms from its surface would provide continuous refrigeration. We analyze the feasibility of such a system in light of previous experimental demonstrations of its essential components: magnetic levitation of mm-scale and cm-scale drops of liquid He , evaporative cooling of He droplets in vacuum, and coupling to high-quality optical whispering-gallery modes in a wide range of liquids. We find that the combination of these features could result in a device that approaches the single-photon strong-coupling regime, due to the high optical quality factors attainable at low temperatures. Moreover, the system offers a unique opportunity to use optical techniques to study the motion of a superfluid that is freely levitating in vacuum (in the case of 4He). Alternatively, for a normal fluid drop of 3He, we propose to exploit the coupling between the drop's rotations and vibrations to perform quantum nondemolition measurements of angular momentum.

  8. Drop impact entrapment of bubble rings

    KAUST Repository

    Thoraval, M.-J.

    2013-04-29

    We use ultra-high-speed video imaging to look at the initial contact of a drop impacting on a liquid layer. We observe experimentally the vortex street and the bubble-ring entrapments predicted numerically, for high impact velocities, by Thoraval et al. (Phys. Rev. Lett., vol. 108, 2012, article 264506). These dynamics mainly occur within 50 -s after the first contact, requiring imaging at 1 million f.p.s. For a water drop impacting on a thin layer of water, the entrapment of isolated bubbles starts through azimuthal instability, which forms at low impact velocities, in the neck connecting the drop and pool. For Reynolds number Re above -12 000, up to 10 partial bubble rings have been observed at the base of the ejecta, starting when the contact is -20% of the drop size. More regular bubble rings are observed for a pool of ethanol or methanol. The video imaging shows rotation around some of these air cylinders, which can temporarily delay their breakup into micro-bubbles. The different refractive index in the pool liquid reveals the destabilization of the vortices and the formation of streamwise vortices and intricate vortex tangles. Fine-scale axisymmetry is thereby destroyed. We show also that the shape of the drop has a strong influence on these dynamics. 2013 Cambridge University Press.

  9. Drop splash on a smooth, dry surface

    Science.gov (United States)

    Riboux, Guillaume; Gordillo, Jose Manuel; Korobkin, Alexander

    2013-11-01

    It is our purpose here to determine the conditions under which a drop of a given liquid with a known radius R impacting against a smooth impermeable surface at a velocity V, will either spread axisymmetrically onto the substrate or will create a splash, giving rise to usually undesired star-shaped patterns. In our experimental setup, drops are generated injecting low viscosity liquids falling under the action of gravity from a stainless steel hypodermic needle. The experimental observations using two high speed cameras operating simultaneously and placed perpendicularly to each other reveal that, initially, the drop deforms axisymmetrically, with A (T) the radius of the wetted area. For high enough values of the drop impact velocity, a thin sheet of liquid starts to be ejected from A (T) at a velocity Vjet > V for instants of time such that T >=Tc . If Vjet is above a certain threshold, which depends on the solid wetting properties as well as on the material properties of both the liquid and the atmospheric gas, the rim of the lamella dewets the solid to finally break into drops. Using Wagner's theory we demonstrate that A (T) =√{ 3 RVT } and our results also reveal that Tc We - 1 / 2 =(ρV2 R / σ) - 1 / 2 and Vjet We 1 / 4 .

  10. Drop impact on inclined superhydrophobic surfaces

    Science.gov (United States)

    Choi, Wonjae; Leclear, Sani; Leclear, Johnathon; Abhijeet, .; Park, Kyoo-Chul

    We report an empirical study and dimensional analysis on the impact patterns of water drops on inclined superhydrophobic surfaces. While the classic Weber number determines the spreading and recoiling dynamics of a water drop on a horizontal / smooth surface, for a superhydrophobic surface, the dynamics depends on two distinct Weber numbers, each calculated using the length scale of the drop or of the pores on the surface. Impact on an inclined superhydrophobic surface is even more complicated, as the velocity that determines the Weber number is not necessarily the absolute speed of the drop but the velocity components normal and tangential to the surface. We define six different Weber numbers, using three different velocities (absolute, normal and tangential velocities) and two different length scales (size of the drop and of the texture). We investigate the impact patterns on inclined superhydrophobic surfaces with three different types of surface texture: (i) posts, (ii) ridges aligned with and (iii) ridges perpendicular to the impact direction. Results suggest that all six Weber numbers matter, but affect different parts of the impact dynamics, ranging from the Cassie-Wenzel transition, maximum spreading, to anisotropic deformation. We acknowledge financial support from the Office of Naval Research (ONR) through Contract 3002453812.

  11. Drop impact on spherical soft surfaces

    Science.gov (United States)

    Chen, Simeng; Bertola, Volfango

    2017-08-01

    The impact of water drops on spherical soft surfaces is investigated experimentally through high-speed imaging. The effect of a convex compliant surface on the dynamics of impacting drops is relevant to various applications, such as 3D ink-jet printing, where drops of fresh material impact on partially cured soft substrates with arbitrary shape. Several quantities which characterize the morphology of impacting drops are measured through image-processing, including the maximum and minimum spreading angles, length of the wetted curve, and dynamic contact angle. In particular, the dynamic contact angle is measured using a novel digital image-processing scheme based on a goniometric mask, which does not require edge fitting. It is shown that the surface with a higher curvature enhances the retraction of the spreading drop; this effect may be due to the difference of energy dissipation induced by the curvature of the surface. In addition, the impact parameters (elastic modulus, diameter ratio, and Weber number) are observed to significantly affect the dynamic contact angle during impact. A quantitative estimation of the deformation energy shows that it is significantly smaller than viscous dissipation.

  12. The lift force on a drop in unbounded plane Poiseuille flow

    Science.gov (United States)

    Wohl, P. R.

    1976-01-01

    The lift force on a deformable liquid sphere moving in steady, plane Poiseuille-Stokes flow and subjected to an external body force is calculated. The results are obtained by seeking a solution to Stokes' equations for the motion of the liquids inside and outside the slightly perturbed sphere surface, as expansions valid for small values of the ratio of the Weber number to the Reynolds number. When the ratio of the drop and external fluid viscosities is small, the lift exerted on a neutrally buoyant drop is found to be approximately one-tenth of the magnitude of the force reported by Wohl and Rubinow acting on the same drop in unbounded Poiseuille flow in a tube. The resultant trajectory of the drop is calculated and displayed as a function of the external body force.

  13. Nonreciprocal photonic crystal add-drop filter

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Keyu [THz Technical Research Center of Shenzhen University, Shenzhen 518067 (China); Shenzhen Key Laboratory of Micro-Nano Photonic Information Technology, Shenzhen 518067 (China); College of Electronic Science and Technology, Shenzhen University, Shenzhen 518067 (China); Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado 80309 (United States); Xiao, Jun-Jun [College of Electronic and Information Engineering, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055 (China); Yin, Xiaobo, E-mail: Xiaobo.Yin@Colorado.Edu [Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado 80309 (United States); Materials Science and Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309 (United States)

    2014-11-24

    We present a versatile add-drop integrated photonic filter (ADF) consisting of nonreciprocal waveguides in which the propagation of light is restricted in one predetermined direction. With the bus and add/drop waveguides symmetrically coupled through a cavity, the four-port device allows each individual port to add and/or drop a signal of the same frequency. The scheme is general and we demonstrate the nonreciprocal ADF with magneto-optical photonic crystals. The filter is immune to waveguide defects, allowing straightforward implementation of multi-channel ADFs by cascading the four-port designs. The results should find applications in wavelength-division multiplexing and related integrated photonic techniques.

  14. Drop impact on porous superhydrophobic polymer surfaces.

    Science.gov (United States)

    Rioboo, R; Voué, M; Vaillant, A; De Coninck, J

    2008-12-16

    Water drop impacts are performed on porous-like superhydrophobic surfaces. We investigate the influence of the drop size and of the impact velocity on the event. The Cassie-Baxter/Wenzel transition is observed to be a function of the drop size, as well as the outcomes of the impact or deposition process, which can be deposition, rebound, sticking, or fragmentation. A quantitative analysis on the experimental conditions required to observe rebound is provided. Our analysis shows that the wettability hysteresis controls the limit between deposition and rebound events. This limit corresponds to a constant Weber number. A survey of literature results on impact over patterned superhydrophobic surfaces is provided as a comparison.

  15. Water Drops Dancing on Ice: How Sublimation Leads to Drop Rebound

    Science.gov (United States)

    Antonini, C.; Bernagozzi, I.; Jung, S.; Poulikakos, D.; Marengo, M.

    2013-07-01

    Drop rebound is a spectacular event that appears after impact on hydrophobic or superhydrophobic surfaces but can also be induced through the so-called Leidenfrost effect. Here we demonstrate that drop rebound can also originate from another physical phenomenon, the solid substrate sublimation. Through drop impact experiments on a superhydrophobic surfaces, a hot plate, and solid carbon dioxide (commonly known as dry ice), we compare drop rebound based on three different physical mechanisms, which apparently share nothing in common (superhydrophobicity, evaporation, and sublimation), but lead to the same rebound phenomenon in an extremely wide temperature range, from 300°C down to even below -79°C. The formation and unprecedented visualization of an air vortex ring around an impacting drop are also reported.

  16. Transformation of the bridge during drop separation

    Science.gov (United States)

    Chashechkin, Yu. D.; Prokhorov, V. E.

    2016-05-01

    The geometry of flows during separation of pendant drops of liquids with significantly different physical properties (alcohol, water, glycerin, oil) has been studied by high-speed video recording. The dynamics of the processes involving the formation of bridges of two characteristic shapes—slightly nonuniform in thickness and with thinning of the upper and lower ends—has been investigated. It has been shown that the shape change of the separated bridge has a number of stages determined by the properties of the liquid. As a result, the bridge is transformed into a small drop—a satellite drop.

  17. Shuttlecock Velocity of a Badminton Drop Shot

    Directory of Open Access Journals (Sweden)

    Ampharin Ongvises

    2013-01-01

    Full Text Available In a badminton ‘drop shot’, the shuttlecock is struck by a non-rotating racquet at low speed. In this investigation, a shuttlecock was hit by a badminton racquet in a linear collision, simulating a drop shot. The collision was recorded with high-speed video and the velocities of the racquet and shuttlecock determined. The relationship between the impact velocity of the racquet and the velocity of the shuttlecock as it leaves the badminton racquet after collision was found to be proportional over the range tested.

  18. Shuttlecock Velocity of a Badminton Drop Shot

    Directory of Open Access Journals (Sweden)

    Ampharin Ongvises

    2013-12-01

    Full Text Available In a badminton ‘drop shot’, the shuttlecock is struck by a non-rotating racquet at low speed. In this investigation, a shuttlecock was hit by a badminton racquet in a linear collision, simulating a drop shot. The collision was recorded with high-speed video and the velocities of the racquet and shuttlecock determined. The relationship between the impact velocity of the racquet and the velocity of the shuttlecock as it leaves the badminton racquet after collision was found to be proportional over the range tested.

  19. Reduction in drop size of ophthalmic topical drop preparations and the impact of treatment

    Directory of Open Access Journals (Sweden)

    Shiva Kumar

    2011-01-01

    Full Text Available In this work we devised a method to create smaller eye drops of the glaucoma medication timolol maleate by altering the dropper tip design and changing the physical properties of the formulation. Most ocular diseases are treated with topical application of eye drops. After instillation of an eye drop, typically, less than 5% of the applied drug penetrates the cornea and reaches the intraocular tissues; the major fraction of the instilled drug is absorbed and enters the systemic circulation. Ophthalmic solutions are available in multidose or single-dose glass/plastic dropper bottles that deliver drops with a volume that ranges from 25 μL to 70 μL (average 40 μL. Because of the low capacity of the precorneal area, the optimal drop volume is about 20 μL; with larger volumes there is the risk of adverse systemic effects due to absorption of the drug via the nasal mucosa. Thus, both from the biopharmaceutical and economic point of view, drops of only 5-15 mL volume should be instilled into the eye. In this present work we devised a method to reduce the size of the drop by inserting a glass capillary tube into the dropper tip and by changing the physical properties of the formulation (by altering the concentration of Tween 80™, i.e., 0.05% and 0.1% of Tween 80™. We measured the drop sizes of the different timolol eye drop formulations available in the market and estimated the yearly cost of the medications. Our timolol maleate formulation with 0.1% concentration of Tween 80™ delivered through the dropper tip with the inserted glass capillary was shown to be better than the other formulations available in the market in terms of ability to deliver smaller drops, meaning that each bottle would last longer and that the yearly cost of treatment would be lower.

  20. Novel mRNA-specific effects of ribosome drop-off on translation rate and polysome profile.

    Science.gov (United States)

    Bonnin, Pierre; Kern, Norbert; Young, Neil T; Stansfield, Ian; Romano, M Carmen

    2017-05-01

    The well established phenomenon of ribosome drop-off plays crucial roles in translational accuracy and nutrient starvation responses during protein translation. When cells are under stress conditions, such as amino acid starvation or aminoacyl-tRNA depletion due to a high level of recombinant protein expression, ribosome drop-off can substantially affect the efficiency of protein expression. Here we introduce a mathematical model that describes the effects of ribosome drop-off on the ribosome density along the mRNA and on the concomitant protein synthesis rate. Our results show that ribosome premature termination may lead to non-intuitive ribosome density profiles, such as a ribosome density which increases from the 5' to the 3' end. Importantly, the model predicts that the effects of ribosome drop-off on the translation rate are mRNA-specific, and we quantify their resilience to drop-off, showing that the mRNAs which present ribosome queues are much less affected by ribosome drop-off than those which do not. Moreover, among those mRNAs that do not present ribosome queues, resilience to drop-off correlates positively with the elongation rate, so that sequences using fast codons are expected to be less affected by ribosome drop-off. This result is consistent with a genome-wide analysis of S. cerevisiae, which reveals that under favourable growth conditions mRNAs coding for proteins involved in the translation machinery, known to be highly codon biased and using preferentially fast codons, are highly resilient to ribosome drop-off. Moreover, in physiological conditions, the translation rate of mRNAs coding for regulatory, stress-related proteins, is less resilient to ribosome drop-off. This model therefore allows analysis of variations in the translational efficiency of individual mRNAs by accounting for the full range of known ribosome behaviours, as well as explaining mRNA-specific variations in ribosome density emerging from ribosome profiling studies.

  1. Expanding subjectivities

    DEFF Research Database (Denmark)

    Lundgaard Andersen, Linda; Soldz, Stephen

    2012-01-01

    A major theme in recent psychoanalytic thinking concerns the use of therapist subjectivity, especially “countertransference,” in understanding patients. This thinking converges with and expands developments in qualitative research regarding the use of researcher subjectivity as a tool to understa...

  2. Modeling merging behavior at lane drops.

    Science.gov (United States)

    2015-02-01

    In work-zone configurations where lane drops are present, merging of traffic at the taper presents an operational concern. In : addition, as flow through the work zone is reduced, the relative traffic safety of the work zone is also reduced. Improvin...

  3. 49 CFR 178.603 - Drop test.

    Science.gov (United States)

    2010-10-01

    ... of anti-freeze. Water/anti-freeze solutions with a minimum specific gravity of 0.95 for testing at... than flat drops, the center of gravity of the test packaging must be vertically over the point of... is performed with water: (i) Where the materials to be carried have a specific gravity not exceeding...

  4. Goose droppings as food for reindeer

    NARCIS (Netherlands)

    van der Wal, R; Loonen, MJJE

    Feeding conditions for Svalbard reindeer, Rangifer tarandus platyrhynchus, on Spitsbergen are generally poor, owing to low availability of forage. We report on coprophagy: the use of goose faeces as an alternative food source for reindeer. Fresh droppings from Barnacle Geese, Branta leucopsis,

  5. DROP AMALGAM VOLTAMMETRIC STUDY OF LEAD ...

    African Journals Online (AJOL)

    a

    ABSTRACT. A study of inorganic complexation of lead using drop amalgam voltammetry is described. The study has been carried out in simulated salt lake water and at ionic strength of. 7.35 M, the predetermined ionic strength of Lake Katwe. The complexation of lead with the simple ligands (Cl-, CO3. 2-) created anodic ...

  6. Spontaneous evaporation of the acetone drop

    Science.gov (United States)

    Dunin, S. Z.; Nagornov, O. V.

    2017-12-01

    The exact solution of the problem on evaporation of the acetone sessile drop at solid substrate is derived. The solution allows us to analyze the temperature field behavior at various thermodynamic parameters. The Marangoni forces are calculated in explicit form. The solution can be used to check numerical approaches for similar problems.

  7. An evaporation model of multicomponent solution drops

    Science.gov (United States)

    Sartori, Silvana; Liñán, Amable; Lasheras, Juan C.

    2010-11-01

    Solutions of polymers are widely used in the pharmaceutical industry as tablets coatings. These allow controlling the rate at which the drug is delivered, taste or appearance. The coating is performed by spraying and drying the tablets at moderate temperatures. The wetting of the coating solution on the pill's surface depends on the droplet Webber and Re numbers, angle of impact and on the rheological properties of the droplet. We present a model for the evaporation of multicomponent solutions droplets in a hot air environment with temperatures substantially lower than the boiling temperature of the solvent. As the liquid vaporizes from the surface the fluid in the drop increases in concentration, until reaching its saturation point. After saturation, precipitation occurs uniformly within the drop. As the surface regresses, a compacting front formed by the precipitate at its maximum packing density advances into the drop, while the solute continues precipitating uniformly. This porous shell grows fast due to the double effect of surface regression and precipitation. The evaporation rate is determined by the rates at which heat is transported to the droplet surface and at which liquid vapor diffuses away from it. When the drop is fully compacted, the evaporation is drastically reduced.

  8. Utah Drop-Out Drug Use Questionnaire.

    Science.gov (United States)

    Governor's Citizen Advisory Committee on Drugs, Salt Lake City, UT.

    This questionnaire assesses drug use practices in high school drop-outs. The 79 items (multiple choice or apply/not apply) are concerned with demographic data and use, use history, reasons for use/nonuse, attitudes toward drugs, availability of drugs, and drug information with respect to narcotics, amphetamines, LSD, Marijuana, and barbiturates.…

  9. 49 CFR 178.965 - Drop test.

    Science.gov (United States)

    2010-10-01

    ... Large Packaging design types and performed periodically as specified in § 178.955(e) of this subpart. (b...) Conditioning. Rigid plastic Large Packagings and Large Packagings with plastic inner receptacles must be... § 178.960(d). (d) Test method. (1) Samples of all Large Packaging design types must be dropped onto a...

  10. 49 CFR 178.810 - Drop test.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR PACKAGINGS Testing of IBCs... design types and performed periodically as specified in § 178.801(e) of this subpart. (b) Special preparation for the drop test. (1) Metal, rigid plastic, and composite IBCs intended to contain solids must be...

  11. Check valves with drop-shaped disk

    Energy Technology Data Exchange (ETDEWEB)

    1943-03-19

    This report discusses improvements possible with drop check valves. Up to the time of the report, the most important improvements had been: (1) lightening of the drop by hollowing it out, (2) reducing lift to reduce impact, (3) increasing clearance in the guide to minimize the danger of it getting stuck, (4) drilling of a safety hole which would indicate excessive wear of the housing by a leak. Other possibilities for the above improvements had produced the following conclusions: (1) a further lightening of the drop was found possible by milling out the halves with a milling cutter, by welding them together and thus eliminating the threaded portion, or by having the drop open on the bottom; (2) further reduction in lift was not found possible in most sizes, but for reduction of the impact effect by a cushion of oil or paste, the seating surface was widened as much as possible; (3) sticking of certain check valves caused by ferrous sulfide deposits could be solved by use of a certain bushing in the housing; (4) some plants favored and some disfavored the safety hole, but in general, plants were to service check valves and change them at such regular intervals as experience dictated; (5) the seat plate was no longer solid steel, but a welded piece.

  12. Lightweight, Economical Device Alleviates Drop Foot

    Science.gov (United States)

    Deis, B. C.

    1983-01-01

    Corrective apparatus alleviates difficulties in walking for victims of drop foot. Elastic line attached to legband provides flexible support to toe of shoe. Device used with flat (heelless) shoes, sneakers, crepe-soled shoes, canvas shoes, and many other types of shoes not usable with short leg brace.

  13. A bilateral foot drop due to neuroschistosomiasis.

    NARCIS (Netherlands)

    Wilbers, J.; Idema, A.J.S.; Gijtenbeek, A.

    2010-01-01

    Schistosomiasis is a parasitic disease, uncommon in Europe and the USA. We present an unusual case of intracerebral schistosomiasis, presenting with a bilateral foot drop. We describe unique magnetic resonance spectroscopy characteristics that can contribute to diagnosis and follow up of a

  14. Dynamic in-vivo assessment of navicular drop while running in barefoot, minimalist, and motion control footwear conditions.

    Science.gov (United States)

    Hoffman, Scott E; Peltz, Cathryn D; Haladik, Jeffrey A; Divine, George; Nurse, Matthew A; Bey, Michael J

    2015-03-01

    Running-related injuries are common and previous research has suggested that the magnitude and/or rate of pronation may contribute to the development of these injuries. Accurately and directly measuring pronation can be challenging, and therefore previous research has often relied on navicular drop (under both static and dynamic conditions) as an indirect assessment of pronation. The objectives of this study were to use dynamic, biplane X-ray imaging to assess the effects of three footwear conditions (barefoot, minimalist shoes, motion control shoes) on the magnitude and rate of navicular drop during running, and to determine the association between static and dynamic measures of navicular drop. Twelve healthy distance runners participated in this study. The magnitude and rate of navicular drop were determined by tracking the 3D position of the navicular from biplane radiographic images acquired at 60Hz during the stance phase of overground running. Static assessments of navicular drop and foot posture were also recorded in each subject. Footwear condition was not found to have a significant effect on the magnitude of navicular drop (p=0.22), but motion control shoes had a slower navicular drop rate than running barefoot (p=0.05) or in minimalist shoes (p=0.05). In an exploratory analysis, static assessments of navicular drop and foot posture were found to be poor predictors of dynamic navicular drop in all footwear conditions (p>0.18). Copyright © 2015 Elsevier B.V. All rights reserved.

  15. A Comparative Study Between an Oil-in-Water Emulsion and Nonlipid Eye Drops Used for Rewetting Contact Lenses.

    Science.gov (United States)

    Guthrie, Sarah E; Jones, Lyndon; Blackie, Caroline A; Korb, Donald R

    2015-11-01

    The purpose of this study was to determine the clinical impact of using SYSTANE BALANCE Lubricant Eye Drops (Alcon, Fort Worth, TX), an oil-in-water emulsion, as a rewetting eye drop in symptomatic contact lens wearers. Subjects who had previously experienced contact lens discomfort (CLD), with a mean lens wearing history of 18.6±12.8 years, were randomly assigned to use a Test (SYSTANE BALANCE Lubricant Eye Drops; n=76) or control (habitual nonlipid contact lens rewetting eye drop; n=30) drop over their contact lenses within 5 min of lens insertion and then subsequently at 2 hr intervals up to a maximum of 4 drops per eye daily for a 1-month period. Assessments of subjective comfort, comfortable wearing time, lid wiper epitheliopathy (LWE), and corneal staining were conducted at baseline and after 1 month, after 6 hr of lens wear. Comfort, wearing time, LWE, and corneal staining all showed statistically significant improvements in the test group using SYSTANE BALANCE Lubricant Eye Drops at the 1-month visit compared with baseline data (all P<0.01) and compared with the control group at the 1-month visit (P<0.01, P=0.01, P<0.01, and P=0.03, respectively). The use of SYSTANE BALANCE Lubricant Eye Drops as a rewetting drop in a group of wearers who experienced symptoms of CLD improved subjective comfort scores, increased comfortable wearing time, and reduced signs of LWE and corneal staining, when compared with the use of non-lipid-containing contact lens rewetting eye drops.

  16. Prospective, randomized, controlled comparison of SYSTANE UD eye drops versus VISINE INTENSIV 1% EDO eye drops for the treatment of moderate dry eye.

    Science.gov (United States)

    Jacobi, Christina; Kruse, Friedrich E; Cursiefen, Claus

    2012-12-01

    The aim of this prospective, randomized, clinical, single-center study was to compare the safety and efficacy of 2 ocular surface lubricant eye drops: preservative-free hydroxypropyl (HP)-Guar (SYSTANE UD(®)) eye drops versus preservative-free Tamarindus indica seed polysaccharide (TSP) 1% (VISINE INTENSIV 1% EDO(®)) eye drops. Fifty-six eyes of 28 patients with moderate keratoconjunctivitis sicca (DEWS severity level 2) were enrolled in the trial. Patients were randomized for 2 treatment groups (SYSTANE UD eye drops vs. VISINE INTENSIV 1% EDO eye drops). The eye drops in both groups were applied 5 times per day for 3 months. Statistical analyses were performed using Statistica™ software (Mann-Whitney U-test and Wilcoxon test). P-Values<0.05 were considered significant. After 3 months of treatment the patients of both groups had subjective benefit in the relief of symptoms of dry eye disease evaluated by the Ocular Surface Disease Index (OSDI) questionnaire score. Patients treated with HP-Guar and TSP showed improvements in tear film stability measured by tear break-up time (TBUT), which are statistically significant in the HP-Guar group (P=0.02). The results of this clinical trial show improvements of symptoms and signs in patients with moderate dry eye after the consistent use of preservative-free HP-Guar and TSP lubricant eye drops. Both artificial tear formulations produce amelioration in tear film stability improving eye conditions and patient quality of life. HP-Guar seems to be slightly more effective in improving ocular surface protection by decreasing tear film evaporation.

  17. 3 CFR - Regulatory Review

    Science.gov (United States)

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false Regulatory Review Presidential Documents Other Presidential Documents Memorandum of January 30, 2009 Regulatory Review Memorandum for the Heads of Executive Departments and Agencies For well over two decades, the Office of Information and Regulatory Affairs (OIRA) at...

  18. On the evolution and breakup of slender drops in an extensional flow

    Science.gov (United States)

    Favelukis, M.; Lavrenteva, O. M.; Nir, A.

    2012-04-01

    The evolution of the shape of an elongated drop embedded in an extensional flow is studied in the framework of slender body theory. The external flow has a weak but not neglected inertia. The problem is governed by three dimensionless parameters: the capillary number, the external Reynolds number, and the viscosity ratio between the drop and the external fluid, and exhibits a multiplicity of stationary shapes with only one being stable. Evolution of the drop surface from initial shapes was studied when the flow intensity was either kept constant or subjected to a sudden change. It was shown that the dynamics of the shape evolution can lead to a breakup of the drop or to a stable stationary shape. Two modes of breakup are revealed: an indefinite elongation and a center pinching mode. The former appears when the viscous forces dominate the inertia effects, with the typical case being that of a creeping flow. The latter breakup mode takes over in the presence of inertia when the drop viscosity diminishes with the extreme example being that of an inviscid drop.

  19. Coalescence collision of liquid drops II: Off-center collisions of unequal-size drops

    Directory of Open Access Journals (Sweden)

    Alejandro Acevedo-Malavé

    2011-09-01

    Full Text Available We applied the Smoothed Particle Hydrodynamics method to simulate for first time in the three-dimensional space the hydrodynamic off-center collisions of unequal-size liquid drops in a vacuum environment. The Weber number for several conditions of the droplets dynamics is determined. Also the velocity vector fields inside the drops are shown in the collision process. The evolution of the kinetic and internal energy is shown for the permanent coalescence case. The resulting drops tend to deform, and depending of the Weber number two possible outcomes for the collision of droplets arise: either permanent coalescence or flocculation. In the permanent coalescence of the drops a fragmentation case is modeled, yielding the formation of little satellite droplets.

  20. Coalescence collision of liquid drops I: Off-center collisions of equal-size drops

    Directory of Open Access Journals (Sweden)

    Alejandro Acevedo-Malavé

    2011-09-01

    Full Text Available The Smoothed Particle Hydrodynamics method (SPH is used here to model off-center collisions of equal-size liquid drops in a three-dimensional space. In this study the Weber number is calculated for several conditions of the droplets dynamics and the velocity vector fields formed inside the drops during the collision process are shown. For the permanent coalescence the evolution of the kinetic and internal energy is shown and also the approaching to equilibrium of the resulting drop. Depending of the Weber number three possible outcomes for the collision of droplets is obtained: permanent coalescence, flocculation and fragmentation. The fragmentation phenomena are modeled and the formation of small satellite drops can be seen. The ligament that is formed follows the “end pinching” mechanism and it is transformed into a flat structure.

  1. The Theory of Empty Categories and the Pro-drop Parameter in Modern Greek.

    Science.gov (United States)

    Philippaki-Warburton, Irene

    1987-01-01

    Examines the theory of empty categories in a Government and Binding analysis of Modern Greek syntax. No empty subject category is found and so the pro-drop parameter is a misnomer here. Further support for the correlation between parametric variation and inflexional or morphological properties of a language is presented. (Author/LMO)

  2. Head-on collision of drops: A numerical investigation

    Science.gov (United States)

    Nobari, M. R.; Jan, Y.-J.; Tryggvason, G.

    1993-01-01

    The head-on collision of equal sized drops is studied by full numerical simulations. The Navier-Stokes equations are solved for fluid motion both inside and outside the drops using a front tracking/finite difference technique. The drops are accelerated toward each other by a body force that is turned off before the drops collide. When the drops collide, the fluid between them is pushed outward leaving a thin later bounded by the drop surface. This layer gets progressively thinner as the drops continue to deform and in several of the calculations this double layer is artificially removed once it is thin enough, thus modeling rupture. If no rupture takes place, the drops always rebound, but if the film is ruptured the drops may coalesce permanently or coalesce temporarily and then split again.

  3. Cracks formation during blood drop evaporation

    Science.gov (United States)

    Sobac, Benjamin; Brutin, David; Université de Provence Team

    2011-03-01

    We firstly presented the pattern formation occurring when drops of whole blood desiccate in a recent publication. The phenomena presented evidence to involve lots of physical field such as surface chemistry, haematolology, fluid mechanics, heat transfer, colloids science... All these mechanisms are acting together and produce an axisymetric and reproducible pattern. Dried cellular components are segregated and deposited by a capillary flow. During the evaporation, the system is slowly drying and cracks when stresses are too important leading to the final pattern observed. In this presentation, we will present the mechanisms involved in the formation of crack patterns. The phenomenon presented here with red blood cells as the main colloids involved is very similar to the drying of drop of nanoparticules. We will explain the common point and the differences encountered.

  4. DROP: Durable Reconnaissance and Observation Platform

    Science.gov (United States)

    Parness, Aaron; McKenzie, Clifford F.

    2012-01-01

    Robots have been a valuable tool for providing a remote presence in areas that are either inaccessible or too dangerous for humans. Having a robot with a high degree of adaptability becomes crucial during such events. The adaptability that comes from high mobility and high durability greatly increases the potential uses of a robot in these situations, and therefore greatly increases its usefulness to humans. DROP is a lightweight robot that addresses these challenges with the capability to survive large impacts, carry a usable payload, and traverse a variety of surfaces, including climbing vertical surfaces like wood, stone, and concrete. The platform is crash-proof, allowing it to be deployed in ways including being dropped from an unmanned aerial vehicle or thrown from a large MSL-class (Mars Science Laboratory) rover.

  5. Drop interactions on a viscous film

    Science.gov (United States)

    Costalonga, Maxime; Hack, Michiel; Snoeijer, Jacco

    2017-11-01

    Every morning at their breakfast, cereal eaters can see that floating objects on a liquid bath attracts to form clusters: this is the so-called Cheerios effect. It has been shown recently that droplets on elastic substrates also interact, either attracting or repelling each other depending on the local slope of the substrate where they lie. Here we present an experiment extending these results to the interaction of droplets deposited on a thin viscous film. By measuring independently the velocity of the droplets and the surface topography of the film, we identify non-monotonic interactions that are due to waves appearing on the film. The drag force exerted onto the droplets is also investigated. We show that the thickness of the film below the drop is intrinsically selected by the velocity of the drop, by a mechanism similar to Bretherton's bubble rising in a confining tube.

  6. Semisupervised Community Detection by Voltage Drops

    Directory of Open Access Journals (Sweden)

    Min Ji

    2016-01-01

    Full Text Available Many applications show that semisupervised community detection is one of the important topics and has attracted considerable attention in the study of complex network. In this paper, based on notion of voltage drops and discrete potential theory, a simple and fast semisupervised community detection algorithm is proposed. The label propagation through discrete potential transmission is accomplished by using voltage drops. The complexity of the proposal is OV+E for the sparse network with V vertices and E edges. The obtained voltage value of a vertex can be reflected clearly in the relationship between the vertex and community. The experimental results on four real networks and three benchmarks indicate that the proposed algorithm is effective and flexible. Furthermore, this algorithm is easily applied to graph-based machine learning methods.

  7. A pressure drop model for PWR grids

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Dong Seok; In, Wang Ki; Bang, Je Geon; Jung, Youn Ho; Chun, Tae Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A pressure drop model for the PWR grids with and without mixing device is proposed at single phase based on the fluid mechanistic approach. Total pressure loss is expressed in additive way for form and frictional losses. The general friction factor correlations and form drag coefficients available in the open literatures are used to the model. As the results, the model shows better predictions than the existing ones for the non-mixing grids, and reasonable agreements with the available experimental data for mixing grids. Therefore it is concluded that the proposed model for pressure drop can provide sufficiently good approximation for grid optimization and design calculation in advanced grid development. 7 refs., 3 figs., 3 tabs. (Author)

  8. Measuring Pressure Drop Under Non Ideal Conditions

    Directory of Open Access Journals (Sweden)

    Austin M

    2014-12-01

    Full Text Available The method of measurement of the pressure drop (PD of cigarette filter rods and the draw resistance of cigarettes is defined in ISO 6565-2002 (1. This standard defines the calibration and use of a transfer standard to calibrate the measuring instrument and also defines the measurement procedure for cigarette and filter samples. The procedure described in the standard assumes that the measurement conditions are constant and that the sample is in equilibrium with the measurement environment.

  9. Impact of water drops on small targets

    Science.gov (United States)

    Rozhkov, A.; Prunet-Foch, B.; Vignes-Adler, M.

    2002-10-01

    The collision of water drops against small targets was studied experimentally by means of a high-speed photography technique. The drop impact velocity was about 3.5 m/s. Drop diameters were in the range of 2.8-4.0 mm. The target was a stainless steel disk of 3.9 mm diameter. The drop spread beyond the target like a central cap surrounded by a thin, slightly conical lamella bounded by a thicker rim. By mounting a small obstacle near the target, surface-tension driven Mach waves in the flowing lamella were generated, which are formally equivalent to the familiar compressibility driven Mach waves in gas dynamics. From the measurement of the Mach angle, the values of some flow parameters could be obtained as functions of time, which provided insight into the flow structure. The liquid flowed from the central cap to the liquid rim through the thin lamella at constant momentum flux. At a certain stage of the process, most of the liquid accumulated in the rim and the internal part of the lamella became metastable. In this situation, a rupture wave propagating through the metastable internal part of the lamella caused the rim to retract while forming outwardly directed secondary jets. The jets disintegrated into secondary droplets due to the Savart-Plateau-Rayleigh instability. Prior to the end of the retraction, an internal circular wave of rupture was formed. It originated at the target and then it propagated to meet the retracting rim. Their meeting resulted in a crown of tiny droplets. A theoretical analysis of the ejection process is proposed.

  10. Drag and Drop API v HTML5

    OpenAIRE

    BARABÁŠ, Vít

    2013-01-01

    The work (the bachelor´s thesis) deals with a new way of web application management via the "drag and drop" technique in the HTML5 programming language. The work is divided into two parts. The first part consists of DND API description in HTML5. The support analysis within common web browsers is included as a part of this description. The second, practical part of the thesis focuses on a concept and the following realisation of a photogallery using DND API.

  11. Upper-limb motion and drop jump: effect of expertise.

    Science.gov (United States)

    Laffaye, G; Bardy, B; Taiar, R

    2006-06-01

    In this study, the role of arm motion in a drop jump was investigated in skilled and unskilled subjects. Nine skilled volleyball players and 8 novice individuals performed a series of jumps from two different heights: 30 cm and 60 cm. Free and restricted arm motion were used to determine the effect of arm motion on the vertical jump. Participants were instructed to land on a force plate and jump as high as possible. The ground reaction force was measured with an AMTI force plate (500 Hz). The kinematics of the jumps was recorded with two digital cameras (50 Hz). The motion of the arms during the jumps was found to increase the jump height by 15% for the volleyball players and 12% for unskilled jumpers. Volleyball players performed better in the 60 cm than in 30 cm drop height (+8.5%). In the volleyball players, the peak vertical ground reaction force during take-off increased by 7%, the peak power increased by 10.6% while the peak impact force decreased by 6.3%. Skilled jumpers were found to have a better use of arm motion than novices in (i) increasing the vertical jump performance, (ii) controlling the balance of the body at take-off (iii) leaving the ground with an optimal body orientation.

  12. Corneal sensitivity after topical bromfenac sodium eye-drop instillation

    Directory of Open Access Journals (Sweden)

    Yanai K

    2013-04-01

    Full Text Available Kaori Yanai,1 Jane Huang,1 Kazuaki Kadonosono,2 Eiichi Uchio1 1Department of Ophthalmology, Fukuoka University School of Medicine, Fukuoka, Japan; 2Department of Ophthalmology, Yokohama City University Medical Center, Yokohama, Japan Purpose: To evaluate the safety of bromfenac sodium eye drops from the standpoint of corneal sensitivity and tear secretion in healthy controls following instillation for 1 month. Methods: A prospective single-blind parallel clinical study was conducted in 20 eyes of ten healthy volunteers with no history of ocular or systemic allergic disease, dry eye, contact lens wear, or ocular surgery. Participants were instructed to instill either bromfenac sodium or artificial tears in each eye twice daily for 28 days. Corneal sensitivity tested using a Cochet–Bonnet esthesiometer was evaluated before and immediately after instillation at 7, 14, and 28 days after the initiation of treatment. Tear secretion was also evaluated by Schirmer's eye test before and at 28 days. Results: No significant difference in mean corneal sensitivity and tear-secretion rate was observed between the bromfenac and artificial-tear treatment groups at any time. Conclusion: These results indicate that bromfenac sodium eye drops are safe with respect to corneal sensitivity and tear secretion in subjects with a normal ocular surface condition. Further evaluation is still necessary to determine whether bromfenac is safe in pathological conditions, such as inflammatory disorders and postsurgical cases. Keywords: bromfenac sodium, cornea, sensitivity, tear, nonsteroidal anti-inflammatory drug

  13. Noise levels and hearing thresholds in the drop forging industry.

    Science.gov (United States)

    Taylor, W; Lempert, B; Pelmear, P; Hemstock, I; Kershaw, J

    1984-09-01

    A-weighted equivalent continuous noise levels for hammer and press operations in a drop-forging industry were determined using both tape recordings of the noise and personal noise dosimeters. The results indicated average A-weighted Leq values of 108 dB for hammer operators and 99 dB for press operators. Comparison of hearing level statistics for 716 hammer and press operators and 293 control subjects indicated the severe hazard to hearing of impact noise exposures. For mean exposure times of less than 10 years, hearing levels for the press (99 dB) and hammer (108 dB) operator age groups are nearly identical, and in the latter case are less than those predicted for exposure to equivalent continuous noise. For long-term exposures of 10 years or more, the results of this study indicate that hearing losses resulting from impact noise in the drop-forging industry are as great or greater than those resulting from continuous noise.

  14. Drop impacts on electrospun nanofiber membranes

    Science.gov (United States)

    Sahu, Rakesh P.; Sinha-Ray, Suman; Yarin, Alexander; Pourdeyhimi, Behnam

    2013-11-01

    This work reports a study of drop impacts of polar and non-polar liquids onto electrospun nanofiber membranes (of 8-10 mm thickness and pore sizes of 3-6 nm) with an increasing degree of hydrophobicity. The nanofibers used were electrospun from polyacrylonitrile (PAN), nylon 6/6, polycaprolactone (PCL) and Teflon. It was found that for any liquid/fiber pair there exists a threshold impact velocity (1.5 to 3 m/s) above which water penetrates membranes irrespective of their wettability. The low surface tension liquid left the rear side of sufficiently thin membranes as a millipede-like system of tiny jets protruding through a number of pores. For such a high surface tension liquid as water, jets immediately merged into a single bigger jet, which formed secondary drops due to capillary instability. An especially non-trivial result is that superhydrophobicity of the porous nano-textured Teflon skeleton with the interconnected pores is incapable of preventing water penetration due to drop impact, even at relatively low impact velocities close to 3.46 m/s. A theoretical estimate of the critical membrane thickness sufficient for complete viscous dissipation of the kinetic energy of penetrating liquid corroborates with the experimental data. The current work is supported by the Nonwovens Cooperative Research Center (NCRC).

  15. High-Speed Interferometry Under Impacting Drops

    KAUST Repository

    Langley, Kenneth R.

    2017-08-31

    Over the last decade the rapid advances in high-speed video technology, have opened up to study many multi-phase fluid phenomena, which tend to occur most rapidly on the smallest length-scales. One of these is the entrapment of a small bubble under a drop impacting onto a solid surface. Here we have gone from simply observing the presence of the bubble to detailed imaging of the formation of a lubricating air-disc under the drop center and its subsequent contraction into the bubble. Imaging the full shape-evolution of the air-disc has required μm and sub-μs space and time resolutions. Time-resolved 200 ns interferometry with monochromatic light, has allowed us to follow individual fringes to obtain absolute air-layer thicknesses, based on the eventual contact with the solid. We can follow the evolution of the dimple shape as well as the compression of the gas. The improved imaging has also revealed new levels of detail, like the nature of the first contact which produces a ring of micro-bubbles, highlighting the influence of nanometric surface roughness. Finally, for impacts of ultra-viscous drops we see gliding on ~100 nm thick rarified gas layers, followed by extreme wetting at numerous random spots.

  16. Mixed effects logistic regression models for longitudinal binary response data with informative drop-out.

    Science.gov (United States)

    Ten Have, T R; Kunselman, A R; Pulkstenis, E P; Landis, J R

    1998-03-01

    A shared parameter model with logistic link is presented for longitudinal binary response data to accommodate informative drop-out. The model consists of observed longitudinal and missing response components that share random effects parameters. To our knowledge, this is the first presentation of such a model for longitudinal binary response data. Comparisons are made to an approximate conditional logit model in terms of a clinical trial dataset and simulations. The naive mixed effects logit model that does not account for informative drop-out is also compared. The simulation-based differences among the models with respect to coverage of confidence intervals, bias, and mean squared error (MSE) depend on at least two factors: whether an effect is a between- or within-subject effect and the amount of between-subject variation as exhibited by variance components of the random effects distributions. When the shared parameter model holds, the approximate conditional model provides confidence intervals with good coverage for within-cluster factors but not for between-cluster factors. The converse is true for the naive model. Under a different drop-out mechanism, when the probability of drop-out is dependent only on the current unobserved observation, all three models behave similarly by providing between-subject confidence intervals with good coverage and comparable MSE and bias but poor within-subject confidence intervals, MSE, and bias. The naive model does more poorly with respect to the within-subject effects than do the shared parameter and approximate conditional models. The data analysis, which entails a comparison of two pain relievers and a placebo with respect to pain relief, conforms to the simulation results based on the shared parameter model but not on the simulation based on the outcome-driven drop-out process. This comparison between the data analysis and simulation results may provide evidence that the shared parameter model holds for the pain data.

  17. SUBJECT INDEX

    Indian Academy of Sciences (India)

    Subject Index. Variation of surface electric field during geomagnetic disturbed period at Maitri, Antarctica. 1721. Geomorphology. A simple depression-filling method for raster and irregular elevation datasets. 1653. Decision Support System integrated with Geographic. Information System to target restoration actions in water-.

  18. Laplacian drop shapes and effect of random perturbations on accuracy of surface tension measurement for different drop constellations.

    Science.gov (United States)

    Saad, Sameh M I; Neumann, A Wilhelm

    2015-08-01

    Theoretical drop shapes are calculated for three drop constellations: pendant drops, constrained sessile drops, and unconstrained sessile drops. Based on total Gaussian curvature, shape parameter and critical shape parameter are discussed as a function of different drop sizes and surface tensions. The shape parameter is linked to physical parameters for every drop constellation. The as yet unavailable detailed dimensional analysis for the unconstrained sessile drop is presented. Results show that the unconstrained sessile drop shape depends on a dimensionless volume term and the contact angle. Random perturbations are introduced and the accuracy of surface tension measurement is assessed for precise and perturbed profiles of the three drop constellations. It is concluded that pendant drops are the best method for accurate surface tension measurement, followed by constrained sessile drops. The unconstrained sessile drops come last because they tend to be more spherical at low and moderate contact angles. Of course, unconstrained sessile drops are the only option if contact angles are to be measured. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Drop by drop scattering properties of a radar bin : a numerical experiment

    Science.gov (United States)

    Gires, Auguste; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2016-04-01

    This paper presents the development and initial results of a numerical simulation of pseudo-radar observations computed as the sum of the electric field backscattered by each drop. Simulations are carried out for three successive radar bins with a gate length of 30 m and beam width of 1°. The first step is the simulation of a 100 m x 100 m x 100 m volume with all its drops. The 3D raindrop generator relies on the findings on the rainfall field very small scales (mm to few tens of m) spatio-temporal structure, of the HYDROP experiment and a recent analysis of 2D video disdrometer data in a Multifractal framework. More precisely: (i) The Liquid Water Content (LWC) distribution is represented with the help a multiplicative cascade down to 0.5 m, below which it is considered as homogeneous. (ii) Within each 0.5 x 0.5 x 0.5 m3 patch, liquid water is distributed into drops according to a pre-defined Drop Size Distribution (DSD) and located randomly uniformly. (iii) Such configuration is compared with the one consisting of the same drops uniformly distributed over the 50 x 50 x 50 m3 volume. Then the backscattered field by the drops located within a radar bin are computed as the sum a individual contribution. Antenna beam weighing is taken into account Due to the fact that the radar wave length is much smaller than the "patches" size for rainfall, it appears that as theoretically expected we retrieved an exponential distribution for potential measure horizontal reflectivity. A much lower dispersion is noticed for differential reflectivity. We show that a simple ballistic assumption for drop velocities does not enable to reproduce radar observations, and turbulence must be taken into account. Finally the sensitivity of these outputs to the various model parameters is quantified.

  20. Drop Out or Self-Exclusion? An Analysis of drop out causes in Mexico’s Sonoran High School Students

    Directory of Open Access Journals (Sweden)

    Elba Abril Valdez

    2008-05-01

    Full Text Available The scholar drop out is not an individual decision. It is conditioned by contextual factors which are identified and analyzed in this research paper among high school students. A survey was applied to 147 high school students to know their family situation, scholar history, reasons why they drop out and their future plans, among other relevant reasons. The results indicated that 86% of the surveyed students abandoned the school between the first and the third semester. Their grade average during the last semester studied was 7.49. The main reasons of the desertion of these students were: economic factors, failure in some subjects, and the lack of interest in their studies. 93% of the participants were not satisfied with the academic level they reached. Nonetheless, they did not plan to resume their studies. The results demonstrated the necessity of an intervention model based on educational policies with higher incentives to add to the school system, flexibility of the transit among subsystems and restructuration of the communication network among the principal actors.

  1. Regulatory issues in accreditation of toxicology laboratories.

    Science.gov (United States)

    Bissell, Michael G

    2012-09-01

    Clinical toxicology laboratories and forensic toxicology laboratories operate in a highly regulated environment. This article outlines major US legal/regulatory issues and requirements relevant to accreditation of toxicology laboratories (state and local regulations are not covered in any depth). The most fundamental regulatory distinction involves the purposes for which the laboratory operates: clinical versus nonclinical. The applicable regulations and the requirements and options for operations depend most basically on this consideration, with clinical toxicology laboratories being directly subject to federal law including mandated options for accreditation and forensic toxicology laboratories being subject to degrees of voluntary or state government–required accreditation.

  2. Simplified procedure for determining of drop and stilling basin

    Directory of Open Access Journals (Sweden)

    Ali R. Vatankhah

    2014-03-01

    Full Text Available Drops are used to effectively dissipate the surplus energy of the water flow. A closed conduit drop conveys water and stills it at its downstream. I-type pipe drop is one kind of the closed conduit drops which is used in irrigation networks as a typical hydraulic structure. Sump elevation is an important design parameter for I-type pipe drop. Similarly, in supercritical flow structures, such as open channel chutes, determination of stilling basin invert elevation is very important. At present, these key design parameters are determined by the momentum and energy equations using tedious trial-and-error procedure. In this study, square conduit drop, pipe drop, and rectangular stilling basin are considered, and three explicit equations have been developed by (multiple nonlinear regression technique to determine the sump and stilling basin invert elevations. Being very simple and accurate, these equations can be easily used to design the closed conduit drops and stilling basins by hydraulic engineers.

  3. Reducing pressure drop in a baghouse using flow distributors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [Tajen Institute of Technology, Ping-Tung Hsien (Taiwan). Dept. of Environmental Engineering and Health

    2001-10-01

    The pressure drop of ladder vanes in a baghouse could be reduced by decreasing the vane number and adjusting the inclined angle of the vane. Two types of flow distributors were utilized to test pressure drop caused by the structure of a baghouse. The pressure drops were measured by an inclined manometer under various filtration velocities. The purpose of this study is to understand the improvement effect of pressure drop saving on traditional ladder vanes. 14 refs., 6 figs.

  4. Cerebral infarction presenting with unilateral isolated foot drop.

    Science.gov (United States)

    Kim, Ki-Wan; Park, Jung-Soo; Koh, Eun-Jeong; Lee, Jong-Myong

    2014-09-01

    Weakness of the dorsiflexor muscles of the ankle or toe, referred to as foot drop, is a relatively common presentation. In most cases, foot drop is caused by a lower motor neuron disease such as peroneal peripheral neuropathy, L4-5 radiculopathic sciatic neuropathy, or polyneuropathy. Although upper motor neuron lesions can present as foot drop, the incidence is very rare. Here, we report an extremely rare case in which foot drop was the only presenting symptom of cerebral infarction.

  5. Cerebral Infarction Presenting with Unilateral Isolated Foot Drop

    OpenAIRE

    Kim, Ki-Wan; Park, Jung-Soo; Koh, Eun-Jeong; Lee, Jong-Myong

    2014-01-01

    Weakness of the dorsiflexor muscles of the ankle or toe, referred to as foot drop, is a relatively common presentation. In most cases, foot drop is caused by a lower motor neuron disease such as peroneal peripheral neuropathy, L4-5 radiculopathic sciatic neuropathy, or polyneuropathy. Although upper motor neuron lesions can present as foot drop, the incidence is very rare. Here, we report an extremely rare case in which foot drop was the only presenting symptom of cerebral infarction.

  6. Electrowetting-enhanced microfluidic device for drop generation

    NARCIS (Netherlands)

    Gu, H.; Malloggi, F.G.J.; Vanapalli, Srinivas; Vanapalli Veera, V.S.A.R.; Mugele, Friedrich Gunther

    2008-01-01

    We integrated electrowetting into a microfluidic flow focusing device to study drop generation under the influence of electric fields. Using both the dispersed phase inlet pressure and the applied voltage as control parameters, we find that the range of drop sizes and the drop generation rate can be

  7. How microstructures affect air film dynamics prior to drop impact

    NARCIS (Netherlands)

    van der Veen, Roeland; Hendrix, M.H.W.; Tran, Tuan; Sun, Chao; Tsai, Peichun Amy; Lohse, Detlef

    2014-01-01

    When a drop impacts a surface, a dimple can be formed due to the increased air pressure beneath the drop before it wets the surface. We employ a high-speed color interferometry technique to measure the evolution of the air layer profiles under millimeter-sized drops impacting hydrophobic

  8. Preparation and Stability of Voriconazole Eye Drop Solution▿

    OpenAIRE

    Dupuis, Antoine; Tournier, Nicolas; Le Moal, Gwenaël; Venisse, Nicolas

    2008-01-01

    The combined systemic and topical administration of voriconazole has successfully been used to treat keratomycosis. Because no voriconazole eye drop product is commercially available, we prepared a sterile eye drop solution (10 mg/ml). Voriconazole remains stable over 30 days, providing an eye drop solution suitable for use for the topical treatment of fungal keratitis.

  9. Coalescence, evaporation and particle deposition of consecutively printed colloidal drops

    Science.gov (United States)

    Chhasatia, Viral; Yang, Xin; Shah, Jaymeen; Sun, Ying

    2012-11-01

    In applications such as inkjet printing and spray deposition, colloid drops are often used as building blocks for line and pattern printing where their interactions play important roles in determining the deposition morphology and properties. In this study, the particle deposition dynamics of two consecutively printed evaporating colloidal drops is examined using a fluorescence microscope and a synchronized side-view camera. The results show that the relaxation time of the water-air interface of the merged drop is shorter than that of a single drop impacting on a dry surface. It is also found that both morphology and particle distribution uniformity of the deposit change significantly with varying jetting delay and spatial spacing between two drops. As the drop spacing increases while keeping jetting delay constant, the circularity of the coalesced drop reduces. For the regime where the time scale for drop evaporation is comparable with the relaxation time scale for two drops to completely coalesce, the capillary flow induced by the local curvature variation of the air-water interface redistributes particles inside a merged drop, causing suppression of the coffee-ring effect for the case of a high jetting frequency while resulting in a region of particle accumulation in the middle of the merged drop at a low jetting frequency. By tuning the interplay of wetting, evaporation, capillary relaxation, and particle assembly, the deposition morphology of consecutively printed colloidal drops can be controlled.

  10. Partial coalescence from bubbles to drops

    KAUST Repository

    Zhang, F. H.

    2015-10-07

    The coalescence of drops is a fundamental process in the coarsening of emulsions. However, counter-intuitively, this coalescence process can produce a satellite, approximately half the size of the original drop, which is detrimental to the overall coarsening. This also occurs during the coalescence of bubbles, while the resulting satellite is much smaller, approximately 10 %. To understand this difference, we have conducted a set of coalescence experiments using xenon bubbles inside a pressure chamber, where we can continuously raise the pressure from 1 up to 85 atm and thereby vary the density ratio between the inner and outer fluid, from 0.005 up to unity. Using high-speed video imaging, we observe a continuous increase in satellite size as the inner density is varied from the bubble to emulsion-droplet conditions, with the most rapid changes occurring as the bubble density grows up to 15 % of that of the surrounding liquid. We propose a model that successfully relates the satellite size to the capillary wave mode responsible for its pinch-off and the overall deformations from the drainage. The wavelength of the primary wave changes during its travel to the apex, with the instantaneous speed adjusting to the local wavelength. By estimating the travel time of this wave mode on the bubble surface, we also show that the model is consistent with the experiments. This wavenumber is determined by both the global drainage as well as the interface shapes during the rapid coalescence in the neck connecting the two drops or bubbles. The rate of drainage is shown to scale with the density of the inner fluid. Empirically, we find that the pinch-off occurs when 60 % of the bubble fluid has drained from it. Numerical simulations using the volume-of-fluid method with dynamic adaptive grid refinement can reproduce these dynamics, as well as show the associated vortical structure and stirring of the coalescing fluid masses. Enhanced stirring is observed for cases with second

  11. Drops on hydrophobic surfaces & vibrated fluid surfaces

    DEFF Research Database (Denmark)

    Wind-Willassen, Øistein

    in the literature. Furthermore, we quantify the energy associated with center of mass translation and internal fluid motion. The model predicts trajectories for tracer particles deposited inside the drop, and satisfactorily describes the sliding motion of steadily accelerating droplets. The model can be used...... numerically, and the results are compared to experiments. We provide, again, the most detailed regime diagram of the possible orbits depending on the forcing and the rotation rate of the fluid bath. We highlight each class of orbit, and analyze in depth the wobbling state, precessing orbits, wobble......-leap dynamics, exotic trajectories and the emergence of statistical behavior when the forcing is near the Faraday threshold....

  12. Sudden drop in ground support produces force-related unload response in human overground walking

    DEFF Research Database (Denmark)

    Af Klint, Richard; Nielsen, Jens Bo; Sinkjaer, Thomas

    2009-01-01

    healthy volunteers. Subjects walked unrestrained over a hydraulically actuated platform. On random trials the platform was accelerated downward at 0.8 g, unloading the plantar flexor muscles in midstance or late stance. The drop of the platform resulted in a significant depression of the soleus muscle...... was decreased starting 22 ms (SD 15) after the drop. To investigate the role of length- and velocity-sensitive afferents on the depression in soleus muscle activity, the ankle rotation was arrested by using an ankle foot orthotic as the platform was dropped. Preventing the ankle movement did not significantly......Humans maneuver easily over uneven terrain. To maintain smooth and efficient gait the motor system needs to adapt the locomotor output to the walking environment. In the present study we investigate the role of sensory feedback in adjusting the soleus muscle activity during overground walking in 19...

  13. Safety assessment technology on the free drop impact and puncture analysis of the cask for radioactive material transport

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dew Hey [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of); Lee, Young Shin; Ryu, Chung Hyun; Kim, Hyun Su; Lee, Ho Chul; Hong, Song Jin; Choi, Young Jin; Lee, Jae Hyung; Na, Jae Yun [Chungnam National Univ., Taejon (Korea, Republic of)

    2001-03-15

    In this study, the regulatory condition and analysis condition is analyzed for the free drop and puncture impact analysis to develop the safety assessment technology. Impact analysis is performed with finite element method which is one of the many analysis methods of the shipping cask. LS-DYNA3D and ABAQUS is suitable for the free drop and the puncture impact analysis of the shipping cask. For the analysis model, the KSC-4 that is the shipping cask to transport spent nuclear fuel is investigated. The results of both LS-DYNA3D and ABAQUS is completely corresponded. And The integrity of the shipping cask is verified. Using this study, the reliable safety assessment technology is supplied to the staff. The efficient and reliable regulatory tasks is performed using the standard safety assessment technology.

  14. Regulatory Information By Sector

    Science.gov (United States)

    Find environmental regulatory, compliance, & enforcement information for various business, industry and government sectors, listed by NAICS code. Sectors include agriculture, automotive, petroleum manufacturing, oil & gas extraction & other manufacturing

  15. Evaluation of antimicrobial effectiveness of ophthalmic drops according to the pharmacopeial tests criteria

    Directory of Open Access Journals (Sweden)

    N Samadi

    2009-03-01

    Full Text Available ABSTRACT Background: In this study antimicrobial effectiveness test was performed on eye-drops which had high microbial contaminations in hospital practice to find out whether their antimicrobial efficacies affect the magnitude of microbial contamination during their uses. Materials and Methods: Artificial tear, atropine sulfate, betamethasone, homatropine hydrobromide, phenylephrine hydrochloride, phenylephrine zinc, pilocarpine hydrochloride, tetracaine hydrochloride and tropicamide eye-drops were subjected to the United States Pharmacopeia (USP and British Pharmacopeia (BP antimicrobial preservative effectiveness tests. Results: The results of this study showed that eight out of the nine products met the BP 'B' and USP criteria. The preservative employed in phenylephrine zinc eye-drop did not possess adequate antimicrobial activity against P. aeruginosa. Other eye-drops showed appropriate reductions in bacterial viability after 6 hrs, 24 hrs and 7 days, but showed a very low bacterial recovery after 28 days which didn't comply with the no recovery (NR term of BP 'A' criteria. Since viable microbial counts were usually determined by plate count method, it seems that the term of NR should define an acceptable range. Conclusion: The results indicated that there is not a clear correlation between antimicrobial efficacy testing of eye-drops and the rate of their microbial contamination while are being used. Other factors such as hygienic practices of eye-drops, proper bottle design and training of patients could influence their microbial contaminations. Regulation of in-use efficacy testing of eye-drops which is influenced by the environment, the frequency and technique of use, might be essential

  16. Affordance Boundaries Are Defined by Dynamic Capabilities of Parkour Athletes in Dropping from Various Heights

    Directory of Open Access Journals (Sweden)

    James L. Croft

    2017-09-01

    Full Text Available Available behaviors are determined by the fit between features of the individual and reciprocal features of the environment. Beyond some critical boundary certain behaviors become impossible causing sudden transitions from one movement pattern to another. Parkour athletes have developed multiple movement patterns to deal with their momentum during landing. We were interested in whether drop distance would cause a sudden transition between a two-footed (precision landing and a load-distributing roll and whether the transition height could be predicted by dynamic and geometric characteristics of individual subjects. Kinematics and ground reaction forces were measured as Parkour athletes stepped off a box from heights that were incrementally increased or decreased from 0.6 to 2.3 m. Individuals were more likely to roll from higher drops; those with greater body mass and less explosive leg power, were more likely to transition to a roll landing at a lower height. At some height a two-footed landing is no longer feasible but for some athletes this height was well within the maximum drop height used in this study. During low drops the primary task constraint of managing momentum could be achieved with either a precision landing or a roll. This meant that participants were free to select their preferred landing strategy, which was only partially influenced by the physical demands of the task. However, athletes with greater leg power appeared capable of managing impulse absorption through a leg mediated strategy up to a greater drop height.

  17. Equilibrium drop surface profiles in electric fields

    Science.gov (United States)

    Mugele, F.; Buehrle, J.

    2007-09-01

    Electrowetting is becoming a more and more frequently used tool to manipulate liquids in various microfluidic applications. On the scale of the entire drop, the effect of electrowetting is to reduce the apparent contact angle of partially wetting conductive liquids upon application of an external voltage. Microscopically, however, strong electric fields in the vicinity of the three phase contact line give rise to local deformations of the drop surface. We determined the equilibrium surface profile using a combined numerical, analytical, and experimental approach. We find that the local contact angle in electrowetting is equal to Young's angle independent of the applied voltage. Only on the scale of the thickness of the insulator and beyond does the surface slope assume a value consistent with the voltage-dependent apparent contact angle. This behaviour is verified experimentally by determining equilibrium surface profiles for insulators of various thicknesses between 10 and 250 µm. Numerically and analytically, we find that the local surface curvature diverges algebraically upon approaching the contact line with an exponent -1<μ<0. We discuss the relevance of the local surface properties for dynamic aspects of the contact line motion.

  18. Impact Dynamics of Oxidized Liquid Metal Drops

    CERN Document Server

    Xu, Qin; Jaeger, Heinrich M

    2013-01-01

    With exposure to air, many liquid metals spontaneously generate an oxide layer on their surface. In oscillatory rheological tests, this skin is found to introduce a yield stress that typically dominates the elastic response but can be tuned by exposing the metal to hydrochloric acid solutions of different concentration. We systematically studied the normal impact of eutectic gallium-indium (eGaIn) drops under different oxidation conditions and show how this leads to two different dynamical regimes. At low impact velocity (or low Weber number), eGaIn droplets display strong recoil and rebound from the impacted surface when the oxide layer is removed. In addition, the degree of drop deformation or spreading during the impact is controlled by the oxide skin. We show that the scaling law known from ordinary liquids for the maximum spreading radius as a function of impact velocity can still be applied to the case of oxidized eGaIn if an effective Weber number $We^{\\star}$ is employed that uses an effective surface...

  19. Investigation of the quality of stored red blood cells after simulated air drop in the maritime environment.

    Science.gov (United States)

    Meli, Athinoula; Hancock, Vicky; Doughty, Heidi; Smedley, Steve; Cardigan, Rebecca; Wiltshire, Michael

    2017-11-27

    Maritime medical capability may be compromised by blood resupply. Air-dropped red blood cells (RBCs) is a possible mitigation factor. This study set out to evaluate RBC storage variables after a simulated parachute air drop into the sea, as limited data exist. The air load construction for the air drop of blood was subject to static drop assessment to simulate a worst-case parachute drop scenario. One control and two test Golden Hour shipping containers were each packaged with 10 RBC units. The control box was not dropped; Test Boxes 1 and 2 were further reinforced with waterproof boxes and underwent a simulated air drop on Day 7 or Day 8 postdonation, respectively. One day after the drop and once a week thereafter until Day 43 of storage, RBCs from each box were sampled and tested for full blood counts, hemolysis, adenosine triphosphate, 2,3-diphosphoglycerate, pH, extracellular potassium, glucose, lactate, deformability, and RBC microvesicles. The packaging configuration completed the air drop with no water ingress or physical damage. All units met UK specifications for volume, hemoglobin, and hemolysis. There were no significant differences for any of the variables studied between RBCs in the control box compared to RBCs in Test Boxes 1 and 2 combined over storage. The test proved that the packaging solution and the impact of a maritime air drop as performed in this study, on Day 7 or Day 8 postdonation, did not affect the in vitro quality of RBCs in SAGM over storage for 35 days. © 2017 AABB.

  20. Deformed liquid marbles: Freezing drop oscillations with powders

    KAUST Repository

    Marston, Jeremy

    2012-09-01

    In this work we show that when a liquid drop impacts onto a fine-grained hydrophobic powder, the final form of the drop can be very different from the spherical form with which it impacts. In all cases, the drop rebounds due to the hydrophobic nature of the powder. However, we find that above a critical impact speed, the drop undergoes a permanent deformation to a highly non-spherical shape with a near-complete coverage of powder, which then freezes the drop oscillations during rebound. © 2012 Elsevier B.V.

  1. Investigation of liquid-liquid drop coalescence using tomographic PIV

    Science.gov (United States)

    Ortiz-Dueñas, Cecilia; Kim, Jungyong; Longmire, Ellen K.

    2010-07-01

    High-speed tomographic PIV was used to investigate the coalescence of drops placed on a liquid/liquid interface; the coalescence of a single drop and of a drop in the presence of an adjacent drop (side-by-side drops) was investigated. The viscosity ratio between the drop and surrounding fluids was 0.14, the Ohnesorge number (Oh = μd/(ρdσD)1/2) was 0.011, and Bond numbers (Bo = ( ρ d - ρ s ) gD 2/ σ) were 3.1-7.5. Evolving volumetric velocity fields of the full coalescence process allowed for quantification of the velocity scales occurring over different time scales. For both single and side-by-side drops, the coalescence initiates with an off-axis film rupture and film retraction speeds an order of magnitude larger than the collapse speed of the drop fluid. This is followed by the formation and propagation of an outward surface wave along the coalescing interface with wavelength of approximately 2D. For side-by-side drops, the collapse of the first drop is asymmetric due to the presence of the second drop and associated interface deformation. Overall, tomographic PIV provides insight into the flow physics and inherent three-dimensionalities in the coalescence process that would not be achievable with flow visualization or planar PIV only.

  2. Effect of neighboring particles on drop coalescence at an interface

    Science.gov (United States)

    Bordoloi, Ankur; Adhikari, Deepak; Longmire, Ellen

    2010-11-01

    The coalescence of a liquid drop in the presence of an adjacent solid particle or liquid drop is studied using high-speed visualization and Tomographic PIV. A drop of water/glycerin (W/G), surrounded by silicone oil of matched refractive index, is released onto an underlying W/G interface. A nylon sphere, neutrally buoyant with respect to the drop liquid, is placed adjacent to the drop. Three initial conditions are considered: the particle is wetted in W/G so that the interface maintains an angle of contact with the particle, the particle is wetted in oil so that it rests above the interface, and the particle is placed so that it maintains an angle of contact with the drop already resting above the interface. These cases are compared with that of two neighboring W/G drops. Off-axis rupture near the solid particle was found to be dominant in cases where the particle was wetted with W/G. However, when the particle was wetted with oil, the point of rupture occurred closer to the drop-axis. The film rupture in the drop is followed by retraction of the film and finally collapse of the drop. Both visualization and PIV results show that the trajectory of the collapsing drop depends on the initial contact condition as well as the rupture location.

  3. Emulsion Design. Analysis of Drop Deformations in Mixed Flows

    DEFF Research Database (Denmark)

    Egholm, Runi Ditlev

    2008-01-01

    does not rely on numerical flow field calculations. The results from this analysis indicate that there is a relationship between the average drop deformation and the apparent shear rate. In the second method the experimentally obtained particle track is used together with numerical calculations...... the drop deformation and drop position a twin camera system is applied. In the subsequent data analysis the recorded movies are analysed using an automated image analysis procedure which leads to the deformation history of the drop and the drop trajectory in the device. However, due to the geometric...... by the drop in the rotor-stator device is emulated in the computational box used for carrying out drop shape simulations. Comparison of simulated and experimentally obtained deformations show that in general the agreement is acceptable on a qualitative level. However, the simulations predict deformations...

  4. Electrowetting-driven spreading and jumping of drops in oil

    Science.gov (United States)

    Hong, Jiwoo; Lee, Sang Joon

    2013-11-01

    Electrowetting-based practical applications include digital microfluidics, liquid lenses, and reflective displays. Most of them are performed in water/oil system, because oil medium reduces the contact-angle hysteresis and prevents drop evaporation. In this study, the effects of drop volume, oil viscosity, and applied voltage on the dynamic behaviors of spreading drops, such as transition of spreading pattern and response time, are investigated. Interestingly, jumping phenomena of drops are observed in oil when the applied voltage is turned off after reaching the electrowetted equilibrium radius of drops. A numerical model to predict the transient behavior of jumping drops is formulated based on the phase-field method. The numerical results for the transient deformation of jumping drops show quantitative agreement with the experimental results.

  5. Asymmetry of Drop Impacts on Patterned Hydrophobic Microstructures

    Science.gov (United States)

    Willmott, Geoff; Robson, Simon; Broom, Matheu

    2016-11-01

    When a water drop falls on to a flat solid surface, asymmetries in the geometry of the spreading drop can be specifically determined by patterned surface microstructures. For hydrophobic (or superhydrophobic) micropillar arrays, the most important asymmetric mechanisms appear to be the surface energy of contact lines, and pathways for gas escaping from penetrated microstructure. In this presentation, static wetting and drop impact experiments will be discussed in relation to drop asymmetries. In addition to micropillar arrays, natural superhydrophobic surfaces (leaves) have been studied, and may suggest possibilities for controlling drop impacts in applications. Some of the clearest large scale drop asymmetries on leaves, which are similar to those associated with low drop impact contact times on synthetic surfaces, appear to be caused by features which generate high contact angle hysteresis, and are therefore indicative of poor superhydrophocity.

  6. Learning by the Market: Regulatory Regionalism, Bologna, and Accountability Communities

    Science.gov (United States)

    Jayasuriya, Kanishka

    2010-01-01

    Over the last two decades institutions of higher education have been subject to new modes of regulatory governance. This essay applies a "regulatory lens" to higher education governance with a view to understanding the sometimes contradictory relationship between the globalisation and regionalisation of higher education and the…

  7. Drop Pinch-Off for Discrete Flows from a Capillary

    Directory of Open Access Journals (Sweden)

    Wilson M.C.T.

    2013-07-01

    Full Text Available The problem of drop formation and pinch-off from a capillary tube under the influence of gravity has been extensively studied when the internal capillary pressure gradient is constant. This ensures a continuous time independent flow field inside the capillary tube typically of the Poiseuille flow type. Characteristic drop ejection behaviour includes: periodic drop ejection, drop ejection with associated satellite production, complex dripping, chaotic behaviour and jetting. It is well known that this characteristic behaviour is governed by the Weber (We and Ohnesorge (Oh numbers (for a given Bond number and may be delineated in a We verses Oh operability diagram. An in-depth physical understanding of drop ejection is also of great importance to industry where the tight control of drop size and ejection velocity are of critical importance in industrial processes such as sealants used in electronics assembly and inkjet printing. However, the use of such a continuous flow approach for drop ejection in industry is often impractical since such flows cannot be operator controlled. For this reason it is important to investigate so-called discrete pipe flows where the flow can be turned on and off at will. This means the flow inside the pipe is now time-dependent being controlled in a step-wise fashion. As a first stage in the investigation of drop pinch-off behaviour in discrete pipe flows this paper will study the critical pinch-off time required for drop ejection starting from a pendant drop. This is the discrete amount of time the pipe flow is turned on for in order for a drop to be ejected from the capillary. A Newtonian incompressible free-surface CFD flow code developed at the University of Leeds is used to investigate the critical pinch-off time for a range of internal pipe velocities (the central flow maximum in Poiseuille flow. It is found that the time required for drop ejection to occur decreases exponentially with internal pipe velocity

  8. Crack formation and prevention in colloidal drops

    Science.gov (United States)

    Kim, Jin Young; Cho, Kun; Ryu, Seul-A.; Kim, So Youn; Weon, Byung Mook

    2015-08-01

    Crack formation is a frequent result of residual stress release from colloidal films made by the evaporation of colloidal droplets containing nanoparticles. Crack prevention is a significant task in industrial applications such as painting and inkjet printing with colloidal nanoparticles. Here, we illustrate how colloidal drops evaporate and how crack generation is dependent on the particle size and initial volume fraction, through direct visualization of the individual colloids with confocal laser microscopy. To prevent crack formation, we suggest use of a versatile method to control the colloid-polymer interactions by mixing a nonadsorbing polymer with the colloidal suspension, which is known to drive gelation of the particles with short-range attraction. Gelation-driven crack prevention is a feasible and simple method to obtain crack-free, uniform coatings through drying-mediated assembly of colloidal nanoparticles.

  9. Drop Impact on a Solid Surface

    KAUST Repository

    Josserand, C.

    2015-09-22

    © Copyright 2016 by Annual Reviews. All rights reserved. A drop hitting a solid surface can deposit, bounce, or splash. Splashing arises from the breakup of a fine liquid sheet that is ejected radially along the substrate. Bouncing and deposition depend crucially on the wetting properties of the substrate. In this review, we focus on recent experimental and theoretical studies, which aim at unraveling the underlying physics, characterized by the delicate interplay of not only liquid inertia, viscosity, and surface tension, but also the surrounding gas. The gas cushions the initial contact; it is entrapped in a central microbubble on the substrate; and it promotes the so-called corona splash, by lifting the lamella away from the solid. Particular attention is paid to the influence of surface roughness, natural or engineered to enhance repellency, relevant in many applications.

  10. Drop Impact on to Moving Liquid Pools

    Science.gov (United States)

    Muñoz-Sánchez, Beatriz Natividad; Castrejón-Pita, José Rafael; Castrejón-Pita, Alfonso Arturo; Hutchings, Ian M.

    2014-11-01

    The deposition of droplets on to moving liquid substrates is an omnipresent situation both in nature and industry. A diverse spectrum of phenomena emerges from this simple process. In this work we present a parametric experimental study that discerns the dynamics of the impact in terms of the physical properties of the fluid and the relative velocity between the impacting drop and the moving liquid pool. The behaviour ranges from smooth coalescence (characterized by little mixing) to violent splashing (generation of multiple satellite droplets and interfacial vorticity). In addition, transitional regimes such as bouncing and surfing are also found. We classify the system dynamics and show a parametric diagram for the conditions of each regime. This work was supported by the EPSRC (Grant EP/H018913/1), the Royal Society, Becas Santander Universidades and the International Relationships Office of the University of Extremadura.

  11. Capture of cenospheres by evaporating drops

    Science.gov (United States)

    Leong, K. H.; Ochs, Harry T.; Beard, K. V.

    The capture efficiency of evaporating cloud drops between 60 and 100 μm radius has been measured for 2 μm radius lithium carbonate hollow particles (cenospheres). Since the effective particle density is low compared to a 2-μm solid particle the cenospheres have reduced sedimentation speeds and a negligible inertial capture efficiency. The particles are sufficiently large ( Kn = 0.03) so that the phoretic theory in the slip regime ( Kn < 0.1) should apply. The measured capture efficiencies are significantly above the theoretical computations. There is some evidence to suggest that thermophoresis may be underestimated in the computations. This assessment is contigent on attributing the discrepancy between theory and experiment to the theoretical description of phoresis or its application to our experiment.

  12. The IFSI Experimental Gravitation Group drop tower

    Science.gov (United States)

    Iafolla, Valerio; Fiorenza, Emiliano; Lefevre, Carlo; Nozzoli, Sergio; Peron, Roberto; Reale, Andrea; Santoli, Francesco

    The Experimental Gravitation Group of Istituto di Fisica dello Spazio Interplanetario (IFSI-INAF) has recently completed the development of a drop tower in its laboratories. This new facility is used in the context of the wide range of activities of the Group, in particular for testing high-sensitivity accelerometers and gradiometers. These instruments will be mainly operated in free fall conditions and this facility will be used for simulating these conditions. The tower has an height of 10 m (7-8 m effective fall height). Its capabilities include a magnetic release mechanism, a (variable acceleration) recovery system and will include a telemetry system. Following a description of the facility, the main foreseen uses will be discussed, among them: tests of accelerometer working position stability, release transient effects, capability of test mass initial attitude and angular velocity control, repeatability.

  13. Crack formation and prevention in colloidal drops.

    Science.gov (United States)

    Kim, Jin Young; Cho, Kun; Ryu, Seul-A; Kim, So Youn; Weon, Byung Mook

    2015-08-17

    Crack formation is a frequent result of residual stress release from colloidal films made by the evaporation of colloidal droplets containing nanoparticles. Crack prevention is a significant task in industrial applications such as painting and inkjet printing with colloidal nanoparticles. Here, we illustrate how colloidal drops evaporate and how crack generation is dependent on the particle size and initial volume fraction, through direct visualization of the individual colloids with confocal laser microscopy. To prevent crack formation, we suggest use of a versatile method to control the colloid-polymer interactions by mixing a nonadsorbing polymer with the colloidal suspension, which is known to drive gelation of the particles with short-range attraction. Gelation-driven crack prevention is a feasible and simple method to obtain crack-free, uniform coatings through drying-mediated assembly of colloidal nanoparticles.

  14. Effect of Bilineaster Drop on Neonatal Hyperbilirubinemia

    Directory of Open Access Journals (Sweden)

    Zahra Ameli

    2017-01-01

    Full Text Available Background: Hyperbilirubinemia is considered one of the most prevalent problems in newborns. Phototherapy, exchange transfusion, and herbal medicine are common therapeutic approaches for preventing any neurologic damage in infants with neonatal jaundice. However, herbal medicine is less commonly used. Aim: This study aimed to investigate the effect of bilineaster drop on neonatal hyperbilirubinemia. Method: This study was a randomized clinical trial conducted on 98 term neonates (aged 2-14 days with neonatal jaundice admitted to Ghaem Hospital of Mashhad, Iran, during 2015. These newborns were randomly assigned into intervention (phototherapy and bilineaster drop and control (only phototherapy groups. Total and direct serum bilirubin levels were measured at the time of admission and then 12, 24, 36, and 48 h after treatment. Data were analyzed using independent t-test and repeated measures ANOVA through Stata software (Version 12. Results: The mean ages of the newborns at the time of admission were 6.2 ±2.5 and 6.04 ±2.4 days in the intervention and control groups, respectively. The intervention group showed higher reduction in mean duration of hospital stay, readmission rate, and bilirubin levels 12 and 24 h after the intervention, compared to the control group (P>0.001. However, the two groups demonstrated no statistically significant difference 36 h and 48 h after the intervention (P=0.06, P=0.22, respectively. Repeated measures ANOVA indicated that the intervention had no significant effect on the reduction trend of bilirubin levels (P=0.10 [total], P=0.06 [indirect] in both groups. Nonetheless, bilirubin levels significantly diminished in both groups over time (P

  15. Regulatory Powers of the National Agency Colombia Compra Eficiente

    National Research Council Canada - National Science Library

    Jorge Santos Rodríguez

    2017-01-01

    This paper examines a recent decision by the State Council, in the matter of the regulatory powers of Colombia Compra Eficiente and its competence for issuing administrative rules in the subject of public procurement...

  16. Drop impact on a liquid-liquid interface

    Science.gov (United States)

    Mohamed-Kassim, Zulfaa; Longmire, Ellen K.

    2003-11-01

    The effects of Reynolds number (Re) on the gravity-driven impact of a single drop onto a liquid-liquid interface were studied experimentally using the particle image velocimetry method. The liquid beneath the interface was identical to the drop liquid. Two liquids with different viscosities were used as the ambient above the interface resulting in viscosity ratios (drop to ambient) of 0.14 and 0.33. Index matching and a slight camera inclination were employed to eliminate optical distortion. Image planes were captured at a rate of 500 Hz, and velocity fields were determined from consecutive images. The flow Reynolds numbers based on drop impact velocity and ambient viscosity were 20 and 68 for the lower and higher viscosity ratios, respectively. During the approach toward the interface, the drop shape was more oblate for the higher Re case. At the same time, viscous stresses generated a vortex ring inside each drop and a wake behind it. Each wake contained a detached ring of similar sign to the ring inside the drop. The subsequent deformation of the drop and the interface due to impact was observed to be more radical in the higher Re case. The impingement and shearing of the trailing wake on the upper surface of each drop played a significant role in dissipating the vorticity inside both drops, and the vorticity dissipated faster for lower Re.

  17. Surface wetting effects on drop passage through a confining orifice

    Science.gov (United States)

    Bordoloi, Ankur; Longmire, Ellen

    2013-11-01

    The motion of gravity-driven drops (Bo ~ 2-10) through a sharp-edged confining orifice is studied in a liquid/liquid system for both hydrophobic (HPB) and hydrophilic (HPL) orifice surfaces. The drop interface is tracked by high-speed imaging, and fluid velocity fields are obtained by PIV. When a drop impacts the leading edge of the orifice, the drop fluid contacts the solid surface immediately, and the resulting interfacial contact lines begin propagating away from the edge. The final drop outcome (capture, release or break-up) is influenced by the motion of the contact lines as well as the contact force between the drop fluid and the orifice surface. In the HPB case, the contact line motion is limited, and the contact force acting against drop passage is weak. In the HPL case, the contact line motion strongly inhibits drop passage by spreading fluid across the upper surface of the orifice plate. For drops that break into multiple volumes, the wettability influences both the break-up location and fractional volume of the resulting satellite drop. Supported by DOE (DOE EERE-PMC-10EE0002764).

  18. [Objective evaluation of applying eye drops by elderly patients].

    Science.gov (United States)

    Colomé-Campos, J; Martínez-Salcedo, I; Martorell-Hallado, M C; Romero-Aroca, P

    2014-05-01

    To objectively evaluate the ability and skills of patients older than 65 years to successfully administer a topical ocular eye drop. A prospective study was conducted on a group of 25 patients with a diagnosis of dry eye or glaucoma, undergoing daily treatment with eye drops for at least one year. The procedure was recorded with a video camera at the time of the application. Of the total, 64% were diagnosed with glaucoma and 36% with dry eye. Almost half (44%) needed a single attempt to apply the drop, and 56% required 2 attempts. In terms of the number of eye drops applied, 52% managed with a single drop, 16% 2 drops, a 12% 3 drops, and 20% 4 or more eye drops. Areas where the eye drop was deposited in the first attempt was, 32% into the conjunctival sac, 32% on the outer corner of the eye, 8% in the inner angle, 8% in the nose, 12% on the cheek, 8% in other areas. Self-administration of eye drops by the elderly is a complex activity that can have an effect on the expected results. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  19. Effect of neighboring perturbations on drop coalescence at an interface

    Science.gov (United States)

    Bordoloi, Ankur Deep; Longmire, Ellen K.

    2012-06-01

    Coalescence at a quiescent silicone oil/water glycerine interface was investigated for water/glycerine drops with Bond number ˜7 and Ohnesorge number = 0.01 using high-speed imaging and time-resolved tomographic particle image velocimetry. In addition to a single drop case, three perturbation cases were considered corresponding with a second drop, a solid particle wetted in oil, and a solid particle wetted in water/glycerine placed adjacent to the coalescing drop. Each perturbing object caused an initial tilting of the drop, influencing its rupture location and eventual collapse behavior. Once tilted, drops typically ruptured near their lowest vertical position which was located either toward or away from the perturbing object depending on the case. The initial retraction speed of the ruptured film was higher for drops initially tilted at significant angles, and the local variations in retraction speed correlated well with the expected variations in local film thickness. The drop fluid always collapsed away from the drop axis in the direction of the rupture location in all unperturbed or perturbed cases. In the case of a drop next to a particle wetted in water/glycerine, the collapsing fluid travelled away from the particle, and the downward propagating vortex ring which developed was similar to that resulting from an unperturbed drop rupture. By contrast, the drop fluid collapsed toward either a second drop or a particle wetted in oil. The resulting vortex rings were more asymmetric, and viscous interaction between the particle and collapsing fluid hindered the downward motion of the associated ring.

  20. Graphite/copper alloy interfacial energies determined using the sessile drop method

    Science.gov (United States)

    Devincent, Sandra M.; Ellis, David L.; Michal, Gary M.

    1991-01-01

    Graphite surfaces are not wet by pure copper. This lack of wetting is responsible for a debonding phenomenon that was found in continuous graphite fiber/copper matrix composites materials subjected to elevated temperatures. By suitably alloying copper, its capability to wet graphite surfaces can be enhanced. In situ measurements of graphite/copper alloy wetting angles were made using the sessile drop method. Interfacial energy values were calculated based upon these measurements.

  1. The Influence of Concentrace Mineral Drops on Performance Broiler

    Directory of Open Access Journals (Sweden)

    Sigit Mugiyono

    1999-05-01

    Full Text Available A research has been conducted in Experimental Farm Faculty of Animal Husbandry Unsoed from July 1 st until August 15 th, 1996. The purpose want to study the influence of CMD supplementation in drinking water consists of M0 = control; M1 = 0.5 drops/1000 cc, M2 = 1 drops/1000 cc; M3 = 1.5 drops/1000 cc and M4 = 2 drops/1000cc. The performance observed were growth, body weight, feed consumption, feed conversion, drinking water consumption; and income over feed and mineral cost (IOFMC. The research involved 100 broiler chickens divided that CMD supplementation until 2 drops/1000cc did not significantly affect on the performance of broiler chickens except in income over feed and mineral cost (P<0.05. (Animal Production 1(2: 56-62 (1999 Key Words: broiler, concentrace mineral drops, performance.

  2. Drop Impact on Textile Material: Effect of Fabric Properties

    Directory of Open Access Journals (Sweden)

    Romdhani Zouhaier

    2014-09-01

    Full Text Available This paper presents an experimental study of impact of water drop on a surface in a spreading regime with no splashing. Three surfaces were studied: virgin glass, coating film and woven cotton fabric at different construction parameters. All experiments were carried out using water drop with the same free fall high. Digidrop with high-resolution camera is used to measure the different parameters characterising this phenomenon. Results show an important effect of the height of the free fall on the drop profile and the spreading behaviour. An important drop deformation at the surface impact was observed. Then, fabric construction as the weft count deeply affects the drop impact. For plain weave, an increase of weft count causes a decrease in penetration and increase in the spreading rate. The same result was obtained for coated fabric. Therefore, the impact energy was modified and the drop shape was affected, which directly influenced the spreading rate.

  3. Regulatory affairs for biomaterials and medical devices

    CERN Document Server

    Amato, Stephen F; Amato, B

    2015-01-01

    All biomaterials and medical devices are subject to a long list of regulatory practises and policies which must be adhered to in order to receive clearance. This book provides readers with information on the systems in place in the USA and the rest of the world. Chapters focus on a series of procedures and policies including topics such as commercialization, clinical development, general good practise manufacturing and post market surveillance.Addresses global regulations and regulatory issues surrounding biomaterials and medical devicesEspecially useful for smaller co

  4. DROpS: an object of learning in computer simulation of discrete events

    Directory of Open Access Journals (Sweden)

    Hugo Alves Silva Ribeiro

    2015-09-01

    Full Text Available This work presents the “Realistic Dynamics Of Simulated Operations” (DROpS, the name given to the dynamics using the “dropper” device as an object of teaching and learning. The objective is to present alternatives for professors teaching content related to simulation of discrete events to graduate students in production engineering. The aim is to enable students to develop skills related to data collection, modeling, statistical analysis, and interpretation of results. This dynamic has been developed and applied to the students by placing them in a situation analogous to a real industry, where various concepts related to computer simulation were discussed, allowing the students to put these concepts into practice in an interactive manner, thus facilitating learning

  5. Student Drop Tower Competitions: Dropping In a Microgravity Environment (DIME) and What If No Gravity? (WING)

    Science.gov (United States)

    Hall, Nancy R.; Stocker, Dennis P.; DeLombard, Richard

    2011-01-01

    This paper describes two student competition programs that allow student teams to conceive a science or engineering experiment for a microgravity environment. Selected teams design and build their experimental hardware, conduct baseline tests, and ship their experiment to NASA where it is operated in the 2.2 Second Drop Tower. The hardware and acquired data is provided to the teams after the tests are conducted so that the teams can prepare their final reports about their findings.

  6. Overt and Null Subject Pronouns in Jordanian Arabic

    Directory of Open Access Journals (Sweden)

    Islam M. Al-Momani

    2015-08-01

    Full Text Available The paper aims at examining the role that morphology plays in allowing and/or motivating sentences in Jordanian Arabic (hereafter JA to be formed with or without subject pronouns. It also aims at giving a comprehensive and descriptive presentation of the distribution of overt and null subject pronouns in JA, and tries to determine to what extent there is optionality in its system. Keywords: null subject pronouns, overt subjects, pro-drop languages, verbal inflectional morphology

  7. Drop impact and rebound dynamics on an inclined superhydrophobic surface.

    Science.gov (United States)

    Yeong, Yong Han; Burton, James; Loth, Eric; Bayer, Ilker S

    2014-10-14

    Due to its potential in water-repelling applications, the impact and rebound dynamics of a water drop impinging perpendicular to a horizontal superhydrophobic surface have undergone extensive study. However, drops tend to strike a surface at an angle in applications. In such cases, the physics governing the effects of oblique impact are not well studied or understood. Therefore, the objective of this study was to conduct an experiment to investigate the impact and rebound dynamics of a drop at various liquid viscosities, in an isothermal environment, and on a nanocomposite superhydrophobic surface at normal and oblique impact conditions (tilted at 15°, 30°, 45°, and 60°). This study considered drops falling from various heights to create normal impact Weber numbers ranging from 6 to 110. In addition, drop viscosity was varied by decreasing the temperature for water drops and by utilizing water-glycerol mixtures, which have similar surface tension to water but higher viscosities. Results revealed that oblique and normal drop impact behaved similarly (in terms of maximum drop spread as well as rebound dynamics) at low normal Weber numbers. However, at higher Weber numbers, normal and oblique impact results diverged in terms of maximum spread, which could be related to asymmetry and more complex outcomes. These asymmetry effects became more pronounced as the inclination angle increased, to the point where they dominated the drop impact and rebound characteristics when the surface was inclined at 60°. The drop rebound characteristics on inclined surfaces could be classified into eight different outcomes driven primarily by normal Weber number and drop Ohnesorge numbers. However, it was found that these outcomes were also a function of the receding contact angle, whereby reduced receding angles yielded tail-like structures. Nevertheless, the contact times of the drops with the coating were found to be generally independent of surface inclination.

  8. Studying the field induced breakup of acoustically levitated drops

    Science.gov (United States)

    Warschat, C.; Riedel, J.

    2017-10-01

    Coulomb fission of charged droplets (The terms drop and droplet are often used synonymous. Throughout this manuscript, to avoid confusion, the terms drop and droplet will be used for liquid spheres with radii in the millimeter range and the micrometer range, respectively. In our experiments, the first correspond to the parent drop while the latter describes the ejected progeny droplets.) is a well-studied natural phenomenon. Controlled droplet fission is already successfully employed in several technological applications. Still, since the occurring surface rupture relies on the exact understanding and description of the liquid gas boundary, some details are still under debate. Most empirical systematic studies observe falling micrometer droplets passing through the electric field inside a plate capacitor. This approach, although easily applicable and reliable, limits the experimental degrees of freedom regarding the observable time and the maximum size of the drops and can only be performed in consecutive individual observations of different subsequent drops. Here we present a novel setup to study the field induced breakup of acoustically levitated drops. The design does not bear any restrictions towards the temporal window of observation, and allows handling of drops of a tunable radius ranging from 10 μm to several millimeters and a real-time monitoring of one single drop. Our comprehensive study includes a time resolved visual inspection, laser shadowgraphy, laser induced fluorescence imaging, and ambient mass spectrometric interrogation of the nascent Taylor cone. The results shown for a millimeter sized drop, previously inaccessible for Coulomb fission experiments, are mostly comparable with previous results for smaller drops. The major difference is the time scale and the threshold potential of the drop rupture. Both values, however, resemble theoretically extrapolations to the larger radius. The technique allows for a systematic study of breakup behavior of

  9. Drop-out from a psychodynamic group psychotherapy outpatient unit.

    Science.gov (United States)

    Jensen, Hans Henrik; Mortensen, Erik Lykke; Lotz, Martin

    2014-11-01

    BACKGROUND. Drop-out from psychotherapy is common and represents a considerable problem in clinical practice and research. Aim. To explore pre-treatment predictors of early and late drop-out from psychodynamic group therapy in a public outpatient unit for non-psychotic disorders in Denmark. Methods. Naturalistic design including 329 patients, the majority with mood, neurotic and personality disorders referred to 39-session group therapy. Predictors were socio-demographic and clinical variables, self-reported symptoms (Symptom Check List-90-Revised) and personality style (Millon Clinical Multiaxial Inventory-II). Drop-out was classified into early and late premature termination excluding patients who dropped out for external reasons. Results. Drop-out comprised 20.6% (68 patients) of the sample. Logistic regression revealed social functioning, vocational training, alcohol problems and antisocial behavior to be related to drop-out. However, early drop-outs had prominent agoraphobic symptoms, lower interpersonal sensitivity and compulsive personality features, and late drop-outs cognitive and somatic anxiety symptoms and antisocial personality features. Clinical and psychological variables accounted for the major part of variance in predictions of drop-out, which ranged from 15.6% to 19.5% (Nagelkerke Pseudo R-Square). Conclusion. Social functioning was consistently associated with drop-out, but personality characteristics and anxiety symptoms differentiated between early and late drop-out. Failure to discriminate between stages of premature termination may explain some of the inconsistencies in the drop-out literature. Clinical implications. Before selection of patients to time-limited psychodynamic groups, self-reported symptoms should be thoroughly considered. Patients with agoraphobic symptoms should be offered alternative treatment. Awareness of and motivation to work with interpersonal issues may be essential for compliance with group therapy.

  10. NRC regulatory initiatives

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, T.C. [Nuclear Regulatory Commission (United States)

    1989-11-01

    The US Nuclear Regulatory Commission (NRC) is addressing several low-level waste disposal issues that will be important to waste generators and to States and Compacts developing new disposal capacity. These issues include Greater-Than-Class C (GTCC) waste, mixed waste, below regulatory concern (BRC) waste, and the low-level waste data base. This paper discusses these issues and their current status.

  11. Regulatory unbundling in telecommunications

    OpenAIRE

    Knieps, Günter

    2011-01-01

    Due to its dynamic nature, and the increasing importance of competitive sub-parts, the telecommunications sector provides particularly interesting insights for studying regulatory unbundling. Based on the theory of monopolistic bottle-necks the fallacies of overregulation by undue unbundling obligations are indicated. Neither the promotion of infrastructure competition by mandatory un-bundling of competitive subparts of telecommunications infrastructure, nor regulatory induced network fragmen...

  12. Novel mRNA-specific effects of ribosome drop-off on translation rate and polysome profile.

    Directory of Open Access Journals (Sweden)

    Pierre Bonnin

    2017-05-01

    Full Text Available The well established phenomenon of ribosome drop-off plays crucial roles in translational accuracy and nutrient starvation responses during protein translation. When cells are under stress conditions, such as amino acid starvation or aminoacyl-tRNA depletion due to a high level of recombinant protein expression, ribosome drop-off can substantially affect the efficiency of protein expression. Here we introduce a mathematical model that describes the effects of ribosome drop-off on the ribosome density along the mRNA and on the concomitant protein synthesis rate. Our results show that ribosome premature termination may lead to non-intuitive ribosome density profiles, such as a ribosome density which increases from the 5' to the 3' end. Importantly, the model predicts that the effects of ribosome drop-off on the translation rate are mRNA-specific, and we quantify their resilience to drop-off, showing that the mRNAs which present ribosome queues are much less affected by ribosome drop-off than those which do not. Moreover, among those mRNAs that do not present ribosome queues, resilience to drop-off correlates positively with the elongation rate, so that sequences using fast codons are expected to be less affected by ribosome drop-off. This result is consistent with a genome-wide analysis of S. cerevisiae, which reveals that under favourable growth conditions mRNAs coding for proteins involved in the translation machinery, known to be highly codon biased and using preferentially fast codons, are highly resilient to ribosome drop-off. Moreover, in physiological conditions, the translation rate of mRNAs coding for regulatory, stress-related proteins, is less resilient to ribosome drop-off. This model therefore allows analysis of variations in the translational efficiency of individual mRNAs by accounting for the full range of known ribosome behaviours, as well as explaining mRNA-specific variations in ribosome density emerging from ribosome profiling

  13. Canadian drug regulatory framework.

    Science.gov (United States)

    Kelly, L; Lazzaro, M; Petersen, C

    2007-03-01

    The role of regulatory drug submission evaluators in Canada is to critically assess both the data submitted and the sponsor's interpretation of the data in order to reach an evidence-, and context-based recommendation as to the potential benefits and potential harms (i.e., risks) associated with taking the drug under the proposed conditions of use. The purpose of this document is to outline the regulatory framework in which this assessment occurs, including: defining what "authorization to market a drug in Canada" means, in terms of the role of the sponsor, the responsibility of Health Canada in applying the Food and Drugs Act prior to and after marketing authorization, and the distinction between regulatory authorization versus physician authorization; highlighting organizational, process and legal factors within Health Canada related to authorization of clinical trials and authorization to market a drug; considerations during the review process, such as regulatory and scientific issues related to the drug, patient populations and trial designs; application of international guidelines, and decisions from other jurisdictions; regulatory realities regarding drug authorization, including the requirement for wording in the Product Monograph to accurately reflect the information currently available on the safe and effective use of a drug, and that hypothesis-confirming studies are essential to regulatory endorsement; current issues related to the review of therapies for dementia, such as assessing preventative treatments, and therapies that have symptomatic versus disease-modifying effects, statistical issues regarding missing data, and trial design issues.

  14. Electrowetting-enhanced microfluidic device for drop generation

    Science.gov (United States)

    Gu, Hao; Malloggi, Florent; Vanapalli, Siva A.; Mugele, Frieder

    2008-11-01

    We integrated electrowetting into a microfluidic flow focusing device to study drop generation under the influence of electric fields. Using both the dispersed phase inlet pressure and the applied voltage as control parameters, we find that the range of drop sizes and the drop generation rate can be controlled in a much finer way than with hydrodynamics alone. In particular a "conical spray" regime occurring at a voltage of O(50 V) allows for continuous tuning of the (highly monodisperse) drop diameter from ≈5 to 50 μm at a fixed continuous flow rate.

  15. Electromagnetic radiation due to nonlinear oscillations of a charged drop

    Science.gov (United States)

    Shiryaeva, S. O.; Grigor'ev, A. N.; Kolbneva, N. Yu.

    2016-03-01

    The nonlinear oscillations of a spherical charged drop are asymptotically analyzed under the conditions of a multimode initial deformation of its equilibrium shape. It is found that if the spectrum of initially excited modes contains two adjacent modes, the translation mode of oscillations is excited among others. In this case, the center of the drop's charge oscillates about the equilibrium position, generating a dipole electromagnetic radiation. It is shown that the intensity of this radiation is many orders of magnitude higher than the intensity of the drop's radiation, which arises in calculations of the first order of smallness and is related to the drop's charged surface oscillations.

  16. Reducing pressure drop in a baghouse using flow distributors.

    Science.gov (United States)

    Chen, C J

    2001-10-01

    The pressure drop of ladder vanes in a baghouse could be reduced by decreasing the vane number and adjusting the inclined angle of the vane. Two types of flow distributors were utilized to test pressure drop caused by the structure of a baghouse. The pressure drops were measured by an inclined manometer under various filtration velocities. The purpose of this study is to understand the improvement effect of pressure drop saving for the traditional ladder vanes. Experimental results showed that the pressure drop of the Vane 3-1 configuration (flow distributor with three vanes perpendicular to the inlet flow) was higher than that of the Empty configuration (without flow distributors). The Vane 3-1 configuration could not reduce the pressure drop because of the barrier effect. By reducing the number and adjusting the angle of the vanes, the barrier effect was decreased, and the pressure drop of the Vane 2-1 configuration was much lower than that of the Vane 3-1 configuration. The largest difference in pressure drop between Vane 2-1 and Vane 3-1 was 1.702 cm w.g. at a filtration velocity of 4.17 cm/sec and, in terms of percentage, is 18.52% corresponding to a filtration velocity of 2.25 cm/sec. The improvement effect on the pressure drop saving for Vane 3-1 was significant.

  17. Substrate constraint modifies the Rayleigh spectrum of vibrating sessile drops.

    Science.gov (United States)

    Chang, Chun-Ti; Bostwick, Joshua B; Steen, Paul H; Daniel, Susan

    2013-08-01

    In this work, we study the resonance behavior of mechanically oscillated, sessile water drops. By mechanically oscillating sessile drops vertically and within prescribed ranges of frequencies and amplitudes, a rich collection of resonance modes are observed and their dynamics subsequently investigated. We first present our method of identifying each mode uniquely, through association with spherical harmonics and according to their geometric patterns. Next, we compare our measured resonance frequencies of drops to theoretical predictions using both the classical theory of Lord Rayleigh and Lamb for free, oscillating drops, and a prediction by Bostwick and Steen that explicitly considers the effect of the solid substrate on drop dynamics. Finally, we report observations and analysis of drop mode mixing, or the simultaneous coexistence of multiple mode shapes within the resonating sessile drop driven by one sinusoidal signal of a single frequency. The dynamic response of a deformable liquid drop constrained by the substrate it is in contact with is of interest in a number of applications, such as drop atomization and ink jet printing, switchable electronically controlled capillary adhesion, optical microlens devices, as well as digital microfluidic applications where control of droplet motion is induced by means of a harmonically driven substrate.

  18. Clinical analysis of diclofenac sodium eye drops combined with sodium hyaluronate eye drops for dry eye after ophthalmic surgery

    Directory of Open Access Journals (Sweden)

    Li-Ping Liu

    2017-07-01

    Full Text Available AIM: To study and analyze the clinical efficacy of diclofenac sodium eye drops combined with sodium hyaluronate eye drops in treating dry eyes after ophthalmic surgery. METHODS: Totally 94 eyes from 94 patients with dry eyes were slected, and they were randomly divided into orbervation group and control group. Fouty-seven patients in the control group using conventional treatment combined with sodium hyaluronate eye drops. Other 47 patients in orbervation group were treated with diclofenac sodium eye drops on the basis of control group. We compared symptoms, fluorescein station, tear film break time, Schirmer Ⅰ test between the two groups.RESULTS: Compared with before treatment, patients of both groups with sympotom, fluorescein station score, BUT, and Schirmer Ⅰ test were significantly improved(PPPCONCLUSION: Diclofenac sodium eye drops combined with sodium hyaluronate eye drops have significant efficacy in treatment of dry eyes after ophthalmic surgery, which can effectively relieve clinical symptoms, improve BUT and Schirmer Ⅰ test.

  19. That's one small drop for Mankind...

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    In August, the members of an ISOLDE project called LOI88 successfully employed a new technique to study the interaction of metal ions in a liquid. It’s the first time that specific ions have been studied in a liquid medium - a technical achievement that opens promising doors for biochemistry.   In the heart of the LOI88 experiment: this is the point where the metal ions (from the left) enter the drop.  “More than half of the proteins in the human body contain metal ions such as magnesium, zinc and copper,” explains Monika Stachura, a biophysicist at the University of Copenhagen and the LOI88 project leader. “We know that these elements are crucial to a protein’s structure and function but their behaviour and interactions are not known in detail.” Detecting these ions directly in  a body-like environment is problematic as their closed atomic shells make them invisible to most spectroscopic techniques. However, using ...

  20. Career drop outs of young elite athletes

    Directory of Open Access Journals (Sweden)

    Petra Fišer

    2007-12-01

    Full Text Available The main problem of the study was to examine the characteristics of sports career drop outs of young elite sportswomen and their adaptation to the post-sport life. The sample included 20 ex-young elite sportswomen, who had brought their successful sport careers to an end before the age of 19. We used a modified interview about sports career termination (Cecić Erpič, 1998 for the investigation of the characteristics of their sports careers. To examine the caracteristics of sport careers we used frequency analysis and cluster analysis. The results showed that the participants mostly stated more than one reason for the termination of their career. The most common reasons for career termination were: lack of motivation, bad relations with trainers or co-competitors and dedication to school or education. After the end of a sports career most of the young sportswomen stayed actively in touch with sport, either as trainers, judges, or they remained engaged in sports for recreation.

  1. On the spreading of impacting drops

    CERN Document Server

    Wildeman, Sander; Sun, Chao; Lohse, Detlef

    2016-01-01

    The energy budget and dissipation mechanisms during droplet impact on solid surfaces are studied numerically and theoretically. We find that for high impact velocities and negligible surface friction, about one half of the initial kinetic energy is transformed into surface energy, independent of the impact parameters and the detailed energy loss mechanism(s). We argue that this seemingly universal rule is related to the deformation mode of the droplet and is reminiscent of pipe flow undergoing a sudden expansion, for which the head loss can be calculated by multiplying the kinetic energy of the incoming flow by a geometrical factor. For impacts on a no-slip surface also dissipation in the shear boundary layer at the solid surface is important. In this case the head loss acts as a lower bound on the total dissipation for small viscosities. This new view on the impact problem allows for simple analytical estimates of the maximum spreading diameter of impacting drops as a function of the impact parameters and th...

  2. GENDER, DEBT, AND DROPPING OUT OF COLLEGE.

    Science.gov (United States)

    Dwyer, Rachel E; Hodson, Randy; McLoud, Laura

    2013-02-01

    For many young Americans, access to credit has become critical to completing a college education and embarking on a successful career path. Young people increasingly face the trade-off of taking on debt to complete college or foregoing college and taking their chances in the labor market without a college degree. These trade-offs are gendered by differences in college preparation and support and by the different labor market opportunities women and men face that affect the value of a college degree and future difficulties they may face in repaying college debt. We examine these new realities by studying gender differences in the role of debt in the pivotal event of graduating from college using the 1997 cohort of the national longitudinal Survey of youth. In this article, we find that women and men both experience slowing and even diminishing probabilities of graduating when carrying high levels of debt, but that men drop out at lower levels of debt than do women. We conclude by theorizing that high levels of debt are one of the mechanisms that sort women and men into different positions in the social stratification system.

  3. Effect of polyethylene glycol eye drops in management of dry eyes after cataract surgery

    Directory of Open Access Journals (Sweden)

    Dong-Mei Cai

    2013-11-01

    Full Text Available AIM: To evaluate the effect of polyethylene glycol eye drops on tear film break-up time and symptoms for dry eyes after cataract surgery.METHODS: Eighty patients with dry eyes secondary to cataract surgery who were treated in our hospital from January to August 2013 were randomly divided into group A and group B. Group A was treated with sodium hyaluronate eye drops for one week, and Group B was treated with polyethylene glycol eye drops for one week. The break-up time of tear film was measured and the subjective symptoms were graded before and after the treatment.RESULTS: The tear film break-up time of group A was respectively 3.87±1.12s and 4.21±1.06s before and after the treatment, with no significant difference(P>0.05; it was respectively 3.98±1.04s and 8.98±1.30s with significant difference for group B(PPPPCONCLUSION: Polyethylene glycol eye drops can extend tear film break-up time and improve symptoms of dry eyes. It is an effective drug in treatment of dry eyes after cataract surgery.

  4. 78 FR 44279 - Regulatory Agenda

    Science.gov (United States)

    2013-07-23

    ... July 23, 2013 Part XI Department of Justice Semiannual Regulatory Agenda #0;#0;Federal Register / Vol... CFR Ch. I 27 CFR Ch. II 28 CFR Ch. I, V Regulatory Agenda AGENCY: Department of Justice. ACTION: Semiannual regulatory agenda. SUMMARY: The Department of Justice is publishing its spring 2013 regulatory...

  5. 77 FR 8018 - Regulatory Agenda

    Science.gov (United States)

    2012-02-13

    ... February 13, 2012 Part XVIII National Aeronautics and Space Administration Semiannual Regulatory Agenda #0... AERONAUTICS AND SPACE ADMINISTRATION 14 CFR Ch. V Regulatory Agenda AGENCY: National Aeronautics and Space Administration (NASA). ACTION: Semiannual regulatory agenda. SUMMARY: NASA's regulatory agenda describes those...

  6. 75 FR 79759 - Regulatory Agenda

    Science.gov (United States)

    2010-12-20

    ... Energy ###Semiannual Regulatory Agenda### ] DEPARTMENT OF ENERGY (DOE) DEPARTMENT OF ENERGY Semiannual Regulatory Agenda 10 CFR Chs. II, III, and X 48 CFR Ch. 9 Regulatory Agenda AGENCY: Department of Energy. ACTION: Notice of semiannual regulatory agenda. SUMMARY: The Department of Energy (DOE) has prepared and...

  7. 78 FR 1634 - Regulatory Agenda

    Science.gov (United States)

    2013-01-08

    ... January 8, 2013 Part XVII National Aeronautics and Space Administration Semiannual Regulatory Agenda #0;#0... AERONAUTICS AND SPACE ADMINISTRATION 14 CFR Ch. V Regulatory Agenda AGENCY: National Aeronautics and Space Administration (NASA). ACTION: Semiannual regulatory agenda. SUMMARY: NASA's regulatory agenda describes those...

  8. 75 FR 79799 - Regulatory Agenda

    Science.gov (United States)

    2010-12-20

    ... Justice ###Semiannual Regulatory Agenda### ] DEPARTMENT OF JUSTICE (DOJ) DEPARTMENT OF JUSTICE 8 CFR Ch. V 21 CFR Ch. I 27 CFR Ch. II 28 CFR Ch. I, V Regulatory Agenda AGENCY: Department of Justice. ACTION: Semiannual regulatory agenda. SUMMARY: The Department of Justice is publishing its fall 2010 regulatory...

  9. 77 FR 7972 - Regulatory Agenda

    Science.gov (United States)

    2012-02-13

    ... February 13, 2012 Part XI Department of Justice Semiannual Regulatory Agenda #0;#0;Federal Register / Vol... CFR Ch. I 27 CFR Ch. II 28 CFR Ch. I, V Regulatory Agenda AGENCY: Department of Justice. ACTION: Semiannual regulatory agenda. SUMMARY: The Department of Justice is publishing its fall 2011 regulatory...

  10. 78 FR 44329 - Regulatory Agenda

    Science.gov (United States)

    2013-07-23

    ... July 23, 2013 Part XVIII National Aeronautics and Space Administration Semiannual Regulatory Agenda #0... AERONAUTICS AND SPACE ADMINISTRATION 14 CFR Ch. V Regulatory Agenda AGENCY: National Aeronautics and Space Administration (NASA). ACTION: Semiannual regulatory agenda. SUMMARY: NASA's regulatory agenda describes those...

  11. Assessment of eye drop instillation technique in glaucoma patients

    Directory of Open Access Journals (Sweden)

    Beatriz Fiuza Gomes

    Full Text Available ABSTRACT Purpose: To study the technique of eye drop instillation in glaucoma patients and identify independent factors that may influence their performance. Methods: In this cross-sectional study, 71 consecutive patients with glaucoma or ocular hypertension, self-administering topical anti-glaucoma medications for ≥6 months were evaluated. All patients instilled a tear substitute into the eye with the worst eyesight using the technique normally used at home. The following parameters were evaluated: age, number of years receiving treatment with ocular hypotensive eye drops, time spent to instill the first drop, number of drops instilled, correct location of the eye drops, contact of the bottle with the eye, closing of the eyelids or occlusion of the tear punctum, and asepsis of the hands. Results: The mean age of the patients was 66 ± 10.8 years, and patients were on ocular hypotensive drugs for 11.3 ± 7.3 (range, 2-35 years. Only 28% of the patients were able to correctly instill the eye drops (squeeze out 1 drop and instill it into the conjunctival sac without bottle tip contact. Touching the tip of the bottle to the globe or periocular tissue occurred in 62% of the patients. In 49% of the patients, the eye drops fell on the eyelids or cheek. Two or more drops were squeezed by 27% of the patients. Conclusions: The majority of glaucoma patients were unable to correctly instill eye drops. Age was an independent factor associated with eye drop instillation performance.

  12. The drop height determines neuromuscular adaptations and changes in jump performance in stretch-shortening cycle training.

    Science.gov (United States)

    Taube, W; Leukel, C; Lauber, B; Gollhofer, A

    2012-10-01

    There is an ongoing discussion about how to improve jump performance most efficiently with plyometric training. It has been proposed that drop height influences the outcome, although longitudinal studies are missing. Based on cross-sectional drop jump studies showing height-dependent Hoffmann (H)-reflex activities, we hypothesized that the drop height should influence the neuromuscular activity and thus, the training result. Thirty-three subjects participated as a control or in one of two stretch-shortening cycle (SSC) interventions. Subjects either trained for 4 weeks doing drop jumps from 30, 50, and 75 cm drop heights (SSC1) or completed the same amount of jumps exclusively from 30 cm (SSC2). During training and testing (from 30, 50, and 75 cm), subjects were instructed to minimize the duration of ground contact and to maximize their rebound height. Rebound heights were significantly augmented after SSC1, but a trend was only observed after SSC2. In contrast, the duration of ground contact increased after SSC1 but decreased after SSC2. The performance index (rebound height/duration of ground contact) improved similarly after SSC1 (+14%) and SSC2 (+14%). Changes in performance were accompanied by neuromuscular adaptations: for SSC1, activity of the soleus increased toward take-off (between 120 and 170 ms after touchdown), whereas SSC2-trained subjects showed enhanced activity shortly after ground contact (20-70 ms after touch down). The present study demonstrates a strong link among drop height, neuromuscular adaptation, and performance in SSC training. As the improvement in the performance index was no different after SSC1 or SSC2, the decision whether to apply SSC1 or SSC2 should depend on the specific requirements of the sports discipline. © 2011 John Wiley & Sons A/S.

  13. Universal scaling laws for the disintegration of electrified drops.

    Science.gov (United States)

    Collins, Robert T; Sambath, Krishnaraj; Harris, Michael T; Basaran, Osman A

    2013-03-26

    Drops subjected to strong electric fields emit charged jets from their pointed tips. The disintegration of such jets into a spray consisting of charged droplets is common to electrospray ionization mass spectrometry, printing and coating processes, and raindrops in thunderclouds. Currently, there exist conflicting theories and measurements on the size and charge of these small electrospray droplets. We use theory and simulation to show that conductivity can be tuned to yield three scaling regimes for droplet radius and charge, a finding missed by previous studies. The amount of charge Q that electrospray droplets carry determines whether they are coulombically stable and charged below the Rayleigh limit of stability (Q(R)) or are unstable and hence prone to further explosions once they are formed. Previous experiments reported droplet charge values ranging from 10% to in excess of (Q(R)). Simulations unequivocally show that electrospray droplets are coulombically stable at the instant they are created and that there exists a universal scaling law for droplet charge, Q = 0.44 (Q(R)).

  14. Total sleep time severely drops during adolescence.

    Directory of Open Access Journals (Sweden)

    Damien Leger

    Full Text Available UNLABELLED: Restricted sleep duration among young adults and adolescents has been shown to increase the risk of morbidities such as obesity, diabetes or accidents. However there are few epidemiological studies on normal total sleep time (TST in representative groups of teen-agers which allow to get normative data. PURPOSE: To explore perceived total sleep time on schooldays (TSTS and non schooldays (TSTN and the prevalence of sleep initiating insomnia among a nationally representative sample of teenagers. METHODS: Data from 9,251 children aged 11 to 15 years-old, 50.7% of which were boys, as part of the cross-national study 2011 HBSC were analyzed. Self-completion questionnaires were administered in classrooms. An estimate of TSTS and TSTN (week-ends and vacations was calculated based on specifically designed sleep habits report. Sleep deprivation was estimated by a TSTN - TSTS difference >2 hours. Sleep initiating nsomnia was assessed according to International classification of sleep disorders (ICSD 2. Children who reported sleeping 7 hours or less per night were considered as short sleepers. RESULTS: A serious drop of TST was observed between 11 yo and 15 yo, both during the schooldays (9 hours 26 minutes vs. 7 h 55 min.; p<0.001 and at a lesser extent during week-ends (10 h 17 min. vs. 9 h 44 min.; p<0.001. Sleep deprivation concerned 16.0% of chidren aged of 11 yo vs. 40.5% of those of 15 yo (p<0.001. Too short sleep was reported by 2.6% of the 11 yo vs. 24.6% of the 15 yo (p<0.001. CONCLUSION: Despite the obvious need for sleep in adolescence, TST drastically decreases with age among children from 11 to 15 yo which creates significant sleep debt increasing with age.

  15. Electrowetting-driven oscillating drops sandwiched between two substrates

    NARCIS (Netherlands)

    Mampallil Augustine, Dileep; Eral, Burak; Staicu, A.D.; Mugele, Friedrich Gunther; van den Ende, Henricus T.M.

    2013-01-01

    Drops sandwiched between two substrates are often found in lab-on-chip devices based on digital microfluidics. We excite azimuthal oscillations of such drops by periodically modulating the contact line via ac electrowetting. By tuning the frequency of the applied voltage, several shape modes can be

  16. Vortex Shedding and Depinning of Wind-Forced Liquid Drops

    Science.gov (United States)

    Simon, Roger; White, Edward

    2017-11-01

    Water drops adhere to solid substrates but can depin when wind forcing exceeds the adhesion force provided by surface tension. Schmucker and White (2012.DFD.M4.6) measured critical wind forcing limits for high-Reynolds-number airflow forcing and found a critical constant Weber number, Wecrit = 8.0 , for a range of drop Bond numbers. This work seeks to identify what behavior is associated with Wecrit = 8.0 and why wind-forced drops depin when they do. One hypothesis suggests that, at high Reynolds numbers, drops depin when their interface natural frequency matches the frequency of air vortex shedding in the separated drop wake. We investigate whether a resonance between vortex shedding and drop interface oscillations is involved with depinning. We measure the shedding frequencies behind solid protuberances of the same size as typical drops and, separately, water-drop interface frequencies. We compare our measured values under different flow conditions to establish whether shedding and interface resonance are related to depinning. 1Supported by the National Science Foundation through Grant CBET-1605947.

  17. Liquid-gas mass transfer at drop structures.

    Science.gov (United States)

    Matias, Natércia; Nielsen, Asbjørn Haaning; Vollertsen, Jes; Ferreira, Filipa; Matos, José Saldanha

    2017-05-01

    Over the last decades, considerable progress has been made in the understanding of the sulfur cycle in sewer systems. In spite of a wealth of experimental and field studies that have addressed the release of hydrogen sulfide from free surface flows in gravity sewers and the corresponding air-water mass transfer, little is known about hydrogen sulfide emission under highly turbulent conditions (e.g., drop structures, hydraulic jumps). In this study, experimental work was carried out to analyze the influence of characteristics of drops on reaeration. Physical models were built, mimicking typical sewer drop structures and allowing different types of drops, drop heights, tailwater depths and flow rates. In total, 125 tests were performed. Based on their results, empirical expressions translating the relationship between the mass transfer of oxygen and physical parameters of drop structures were established. Then, by applying the two-film theory with two-reference substances, the relation to hydrogen sulfide release was defined. The experiments confirmed that the choice of the type of drop structure is critical to determine the uptake/emission rates. By quantifying the air-water mass transfer rates between free-fall and backdrop types of drop, the latter resulted in considerably lower oxygen uptake rates.

  18. Cathode potential drop in the channel of a magnetoplasma compressor

    Energy Technology Data Exchange (ETDEWEB)

    Shubin, A.P.

    1977-09-01

    Calculations are carried out for the dissipationless plasma flow in the channel of a magnetoplasma compressor when there is a potential drop near the cathode. This drop appears when the current is carried by ions as the result of the disappearance of ions at the cathode.

  19. Maximal air bubble entrainment at liquid-drop impact

    NARCIS (Netherlands)

    Bouwhuis, W.; van der Veen, Roeland; Tran, Tuan; Keij, D.L.; Winkels, K.G.; Peters, I.R.; van der Meer, Roger M.; Sun, Chao; Snoeijer, Jacobus Hendrikus; Lohse, Detlef

    2012-01-01

    At impact of a liquid drop on a solid surface, an air bubble can be entrapped. Here, we show that two competing effects minimize the (relative) size of this entrained air bubble: for large drop impact velocity and large droplets, the inertia of the liquid flattens the entrained bubble, whereas for

  20. Oscillating and star-shaped drops levitated by an airflow

    NARCIS (Netherlands)

    Bouwhuis, W.; Winkels, K.G.; Peters, I.R.; Brunet, P.; van der Meer, Roger M.; Snoeijer, Jacobus Hendrikus

    2013-01-01

    We investigate the spontaneous oscillations of drops levitated above an air cushion, eventually inducing a breaking of axisymmetry and the appearance of “star drops”. This is strongly reminiscent of the Leidenfrost stars that are observed for drops floating above a hot substrate. The key advantage

  1. Drop interaction with solid boundaries in liquid/liquid systems

    Science.gov (United States)

    Bordoloi, Ankur Deep

    The present experimental work was motivated primarily by the CO 2 sequestration process. In a possible scenario during this process, gravity driven CO2 bubbles coalesce at an interface near the rock surface. In another scenario, trapped CO2 fluid may escape from a porous matrix overcoming interfacial force inside a pore. Based on these potential scenarios, the current research was divided into two broad experimental studies. In the first part, coalescence at a quiescent interface of two analogous fluids (silicone oil and water/glycerin mixture) was investigated for water/glycerin drops with Bond number (Bo) ~7 and Ohnesorge number ~ 0.01 using high-speed imaging and time-resolved tomographic PIV. Two perturbation cases with a solid particle wetted in oil and water/glycerin placed adjacent to the coalescing drop were considered. The results were compared with coalescence of a single drop and that of a drop neighBored by a second drop of equivalent size. Each perturbing object caused an initial tilting of the drop, influencing its rupture location, subsequent film retraction and eventual collapse behavior. Once tilted, drops typically ruptured near their lowest vertical position which was located either toward or away from the perturbing object depending on the case. The trends in local retraction speed of the ruptured film and the overall dynamics of the collapsing drops were discussed in detail. In the second part, the motion of gravity driven drops (B o~0.8-11) through a confining orifice d/Dglycerin, surrounded by silicone oil, fall toward and encounter the orifice plate after reaching terminal speed. The effects of surface wettability were investigated for Both round-edged and sharp-edged orifices. For the round-edged case, a thin film of surrounding oil prevented the drop fluid from contacting the orifice surface, such that the flow outcomes of the drops were independent of surface wettability. For d/D<0.8, the Boundary between drop capture and release depended

  2. Phase II trial to evaluate the ActiGait implanted drop-foot stimulator in established hemiplegia

    DEFF Research Database (Denmark)

    Burridge, Jane H; Haugland, Morten; Larsen, Birgit

    2007-01-01

    OBJECTIVE: To evaluate a selective implantable drop foot stimulator (ActiGait) in terms of effect on walking and safety. DESIGN: A phase II trial in which a consecutive sample of participants acted as their own controls. SUBJECTS: People who had suffered a stroke at least 6 months prior to recrui...

  3. Theory of Planned Behavior: Sensitivity and Specificity in Predicting Graduation and Drop-Out among College and University Students?

    Science.gov (United States)

    Fichten, Catherine S.; Amsel, Rhonda; Jorgensen, Mary; Nguyen, Mai Nhu; Budd, Jillian; King, Laura; Jorgensen, Shirley; Asuncion, Jennison

    2016-01-01

    We examined sensitivity and specificity when using the three theory of planned behavior (TPB) scales (Perceived Behavioral Control, Subjective Norms, Attitude) to predict graduation and drop-out in a longitudinal study of 252 college and university students with disabilities and in a separate cross-sectional study of a random sample of 1380…

  4. Electrowetting-driven oscillating drops sandwiched between two substrates

    Science.gov (United States)

    Mampallil, Dileep; Burak Eral, H.; Staicu, Adrian; Mugele, Frieder; van den Ende, Dirk

    2013-11-01

    Drops sandwiched between two substrates are often found in lab-on-chip devices based on digital microfluidics. We excite azimuthal oscillations of such drops by periodically modulating the contact line via ac electrowetting. By tuning the frequency of the applied voltage, several shape modes can be selected one by one. The frequency of the oscillations is half the frequency of the contact angle modulation by electrowetting, indicating a parametric excitation. The drop response to sinusoidal driving deviates substantially from sinusoidal behavior in a “stop and go” fashion. Although our simple theoretical model describes the observed behavior qualitatively, the resonances appear at lower frequencies than expected. Moreover, the oscillations produce a nonperiodic fluid transport within the drop with a typical velocity of 1 mm/s. In digital microfluidic devices, where the typical drop size is less than 1 mm, this flow can result in very fast mixing on the spot.

  5. Tunable transport of drops on a vibrating inclined fiber

    CERN Document Server

    Bick, Alison; Sauret, Alban; Stone, Howard A

    2015-01-01

    Transport of liquid drops in fibrous media occurs in various engineering systems such as fog harvesting or cleaning of textiles. The ability to tune or to control liquid movement can increase the system efficiency and enable new engineering applications. In this Letter, we experimentally investigate how partially wetting drops on a single fiber can be manipulated by vibrating the fiber. We show that a sliding motion along the fiber or a dripping of the drop can be triggered by standing waves. We identify the conditions on the drop volume, the fiber tilt angle and the amplitude and frequency of oscillations to observe these different behaviors. Finally, we experimentally illustrate that vibrations can be used to control the transport and the collection of water drops along a fiber using a combination of the sliding and dripping transitions.

  6. Silicon wavelength-selective partial-drop broadcast filter bank.

    Science.gov (United States)

    Su, Zhan; Cherchi, Matteo; Timurdogan, Erman; Sun, Jie; Moresco, Michele; Leake, Gerald; Coolbaugh, Douglas; Watts, Michael R

    2014-09-15

    We propose an approach to a wavelength-selective 1×N port optical broadcast network demonstrating the approach in a 1×8 port parallel optical drop filter bank utilizing adiabatic micro-ring tunable filters. The micro-ring filters exhibit first-order 92.7±3.7 GHz full width at half-maximum bandwidths with a 36.2 nm free spectral range, low-drop power variation (0.11 dB), and aggregate excess loss of only 1.1 dB in all drop ports. Error-free operation at a 10 Gbit/s data rate is achieved for all eight drop ports with less than a 0.5 dB power penalty among the ports. This wavelength-selective parallel-drop approach serves as a building block for on-chip all-to-all communication networks.

  7. Capillary-inertial colloidal catapults upon drop coalescence

    Science.gov (United States)

    Chavez, Roger L.; Liu, Fangjie; Feng, James J.; Chen, Chuan-Hua

    2016-07-01

    Surface energy released upon drop coalescence is known to power the self-propelled jumping of liquid droplets on superhydrophobic solid surfaces, and the jumping droplets can additionally carry colloidal payloads toward self-cleaning. Here, we show that drop coalescence on a spherical particle leads to self-propelled launching of the particle from virtually any solid surface. The main prerequisite is an intermediate wettability of the particle, such that the momentum from the capillary-inertial drop coalescence process can be transferred to the particle. By momentum conservation, the launching velocity of the particle-drop complex is proportional to the capillary-inertial velocity based on the drop radius and to the fraction of the liquid mass in the total mass. The capillary-inertial catapult is not only an alternative mechanism for removing colloidal contaminants, but also a useful model system for studying ballistospore launching.

  8. Building micro-soccer-balls with evaporating colloidal fakir drops

    Science.gov (United States)

    Gelderblom, Hanneke; Marín, Álvaro G.; Susarrey-Arce, Arturo; van Housselt, Arie; Lefferts, Leon; Gardeniers, Han; Lohse, Detlef; Snoeijer, Jacco H.

    2013-11-01

    Drop evaporation can be used to self-assemble particles into three-dimensional microstructures on a scale where direct manipulation is impossible. We present a unique method to create highly-ordered colloidal microstructures in which we can control the amount of particles and their packing fraction. To this end, we evaporate colloidal dispersion drops from a special type of superhydrophobic microstructured surface, on which the drop remains in Cassie-Baxter state during the entire evaporative process. The remainders of the drop consist of a massive spherical cluster of the microspheres, with diameters ranging from a few tens up to several hundreds of microns. We present scaling arguments to show how the final particle packing fraction of these balls depends on the drop evaporation dynamics, particle size, and number of particles in the system.

  9. Immediate effects of ankle eversion taping on dynamic and static balance of chronic stroke patients with foot drop.

    Science.gov (United States)

    Shin, Young Jun; Kim, So Min; Kim, Hyun Sung

    2017-06-01

    [Purpose] This study evaluates the immediate effect of ankle eversion taping on dynamic and static balance of chronic stroke patients with foot drop. [Subjects and Methods] This study was conducted with nine subjects who were diagnosed with stroke. A cross-over randomized design was used. Each subject performed three interventions in a random order. Subjects were randomly assigned to an ankle everion taping, placebo taping, and no taping. For dynamic and static balance, ability was measured using BIO Rescue. Limit of stability, sway length and sway speed for one minute were measured. [Results] The Limit of Stability, Sway length and Sway speed differed significantly among the three different taping methods. [Conclusion] We conclude that ankle eversion taping that uses kinesiology tape instantly increases the dynamic and static balance ability of chronic stroke patients with foot drop.

  10. Evaluation of the efficacy and safety of a new device for eye drops instillation in patients with glaucoma.

    Science.gov (United States)

    Junqueira, Daniela M; Lopes, Flavio S; de Souza, Fabiola C; Dorairaj, Syril; Prata, Tiago S

    2015-01-01

    This study evaluated the efficacy and safety of a new device (Eyedrop(®)) designed for eye drop instillation in patients with and without glaucoma. This prospective study included consecutive patients with glaucoma and healthy participants. After a complete eye examination and determination of baseline intraocular pressure (IOP), topical hypotensive medication was introduced in both eyes, and the Eyedrop(®) delivery device (a plastic device in which the bottle with eye drops is inserted) was made available to all participants (with video and written instructions) for use in one eye, randomly chosen. In the second phase, all patients were evaluated by an experienced examiner for IOP determination, investigation of possible associated side effects, and ease of instilling eye drops (by a visual analog scale [VAS]; 0-10). Thirty two participants (mean age 42.3±16.2 years) were evaluated. Of these, 44% had glaucoma. There was no significant difference in mean IOP variation when comparing the eye using (-3.9±2.9 mmHg) or not using the device (-3.3±2.6 mmHg; P=0.36). The subjective rating of the facility of drops instillation was significantly higher with the Eyedrop(®) applicator (VAS =7.6±1.6) than without it (VAS =6.2±1.8; P5) among participants without prior experience with eye drop instillation (78.6% [11/14]) versus those already experienced (66.7% [12/18]). No difference in the frequency of side effects or in the distribution pattern of fluorescein between eyes was observed (P≥0.63). Eyedrop(®) received a better subjective response regarding the ease of instillation of hypotensive eye drops compared to traditional instillation, especially in patients with no previous experience with eye drops. Using the device did not result in any loss of hypotensive effect or increase in the frequency of side effects.

  11. Coalescence and noncoalescence of sessile drops: impact of surface forces.

    Science.gov (United States)

    Karpitschka, Stefan; Hanske, Christoph; Fery, Andreas; Riegler, Hans

    2014-06-17

    Due to capillarity, sessile droplets of identical liquids will instantaneously fuse when they come in contact at their three-phase lines. However, with drops of different, completely miscible liquids, instantaneous coalescence can be suppressed. Instead, the drops remain in a state of noncoalescence for some time, with the two drop bodies connected only by a thin neck. The reason for this noncoalescence is the surface tension difference, Δγ, between the liquids. If Δγ is sufficiently large, then it induces a sufficiently strong Marangoni flow, which keeps the main drop bodies temporarily separated. Studies with spreading drops have revealed that the boundary between instantaneous coalescence and noncoalescence is sharp (Karpitschka, S.; Riegler, H. J. Fluid. Mech. 2014, 743, R1). The boundary is a function of two parameters only: Δγ and Θ(a), the arithmetic mean of the contact angles in the moment of drop-drop contact. It appears plausible that surface forces (the disjoining pressure) could also influence the coalescence behavior. However, in experiments with spreading drops, surface forces always promote coalescence and their influence might be obscured. Therefore, we present here coalescence experiments with partially wetting liquids and compare the results to the spreading case. We adjust different equilibrium contact angles (i.e., different surface forces) with different substrate surface coatings. As for spreading drops, we observe a sharp boundary between regimes of coalescence and noncoalescence. The boundary follows the same power law relation for both partially and completely wetting cases. Therefore, we conclude that surface forces have no significant, explicit influence on the coalescence behavior of sessile drops from different miscible liquids.

  12. Rationales for regulatory activity

    Energy Technology Data Exchange (ETDEWEB)

    Perhac, R.M. [Univ. of Tennessee, Knoxville, TN (United States)

    1997-02-01

    The author provides an outline which touches on the types of concerns about risk evaluation which are addressed in the process of establishing regulatory guides. Broadly he says regulatory activity serves three broad constituents: (1) Paternalism (private risk); (2) Promotion of social welfare (public risks); (3) Protection of individual rights (public risks). He then discusses some of the major issues encountered in reaching a decision on what is an acceptable level of risk within each of these areas, and how one establishes such a level.

  13. Prediction of regulatory elements

    DEFF Research Database (Denmark)

    Sandelin, Albin

    2008-01-01

    Finding the regulatory mechanisms responsible for gene expression remains one of the most important challenges for biomedical research. A major focus in cellular biology is to find functional transcription factor binding sites (TFBS) responsible for the regulation of a downstream gene. As wet......-lab methods are time consuming and expensive, it is not realistic to identify TFBS for all uncharacterized genes in the genome by purely experimental means. Computational methods aimed at predicting potential regulatory regions can increase the efficiency of wet-lab experiments significantly. Here, methods...

  14. Characteristics of patients in an eating disorder sample who dropped out: 2-year follow-up.

    Science.gov (United States)

    Gómez Del Barrio, Andrés; Vellisca Gonzalez, María Yolanda; González Gómez, Jana; Latorre Marín, José Ignacio; Carral-Fernández, Laura; Orejudo Hernandez, Santos; Madrazo Río-Hortega, Inés; Moreno Malfaz, Laura

    2017-07-17

    This manuscript explores the characteristics of individuals diagnosed with an eating disorder who dropped out of treatment, compared with those who completed it. The participants were 196 patients diagnosed with eating disorders (according to DSM-IV-TR criteria) who consecutively began treatment for the first time in an eating disorders unit. They were assessed at baseline with a set of questionnaires evaluating eating habits, temperament, and general psychopathology. During the follow-up period, patients who dropped out were re-assessed via a telephone interview. In the course of a 2-year follow-up, a total of 80 (40.8%) patients were labeled as dropouts, and 116 (59.2%) remaining subjects were considered completers. High TCI scores in the character dimensions of Disorderliness (NS4) (p < .01) and total Novelty Seeking (NST), along with low scores in Dependency (RD4), were significantly associated with dropout in the course of 2 years. Once the results were submitted to logistic regression analysis, dropout only remained associated with high scores in Disorderliness (NS4) and, inversely, with an initial Anorexia Nervosa (AN) diagnosis (p < .05). Reasons for dropout stated by the patients included logistic difficulties, subjective improvement of their condition, and lack of motivation. Clinicians should handle the first therapeutic intervention with particular care in order to enhance their understanding of clients and their ability to rapidly identify those who are at risk of dropping out of treatment. Level III: Cohort Study.

  15. Drop Calculations of HLW Canister and Pu Can-in-Canister

    Energy Technology Data Exchange (ETDEWEB)

    Sreten Mastilovic

    2001-07-31

    The objective of this calculation is to determine the structural response of the standard high-level waste (HLW) canister and the canister containing the cans of immobilized plutonium (Pu) (''can-in-canister'' [CIC] throughout this document) subjected to drop DBEs (design basis events) during the handling operation. The evaluated DBE in the former case is 7-m (23-ft) vertical (flat-bottom) drop. In the latter case, two 2-ft (0.61-m) corner (oblique) drops are evaluated in addition to the 7-m vertical drop. These Pu CIC calculations are performed at three different temperatures: room temperature (RT) (20 C ), T = 200 F = 93.3 C , and T = 400 F = 204 C ; in addition to these the calculation characterized by the highest maximum stress intensity is performed at T = 750 F = 399 C as well. The scope of the HLW canister calculation is limited to reporting the calculation results in terms of: stress intensity and effective plastic strain in the canister, directional residual strains at the canister outer surface, and change of canister dimensions. The scope of Pu CIC calculation is limited to reporting the calculation results in terms of stress intensity, and effective plastic strain in the canister. The information provided by the sketches from Reference 26 (Attachments 5.3,5.5,5.8, and 5.9) is that of the potential CIC design considered in this calculation, and all obtained results are valid for this design only. This calculation is associated with the Plutonium Immobilization Project and is performed by the Waste Package Design Section in accordance with Reference 24. It should be noted that the 9-m vertical drop DBE, included in Reference 24, is not included in the objective of this calculation since it did not become a waste acceptance requirement. AP-3.124, ''Calculations'', is used to perform the calculation and develop the document.

  16. Inverse Leidenfrost effect: self-propelling drops on a bath

    Science.gov (United States)

    Gauthier, Anais; van der Meer, Devaraj; Lohse, Detlef; Physics of Fluids Team

    2017-11-01

    When deposited on very hot solid, volatile drops can levitate over a cushion of vapor, in the so-called Leidenfrost state. This phenomenon can also be observed on a hot bath and similarly to the solid case, drops are very mobile due to the absence of contact with the substrate that sustains them. We discuss here a situation of ``inverse Leidenfrost effect'' where room-temperature drops levitate on a liquid nitrogen pool - the vapor is generated here by the bath sustaining the relatively hot drop. We show that the drop's movement is not random: the liquid goes across the bath in straight lines, a pattern only disrupted by elastic bouncing on the edges. In addition, the drops are initially self-propelled; first at rest, they accelerate for a few seconds and reach velocities of the order of a few cm/s, before slowing down. We investigate experimentally the parameters that affect their successive acceleration and deceleration, such as the size and nature of the drops and we discuss the origin of this pattern.

  17. Clustering of particles and pathogens within evaporating drops

    Science.gov (United States)

    Park, Jaebum; Kim, Ho-Young

    2017-11-01

    The evaporation of sessile suspension drops leads to accumulation of the particles around the pinned contact line, which is widely termed the coffee ring effect. However, the evaporation behavior of a liquid drop containing a small number of particles with the size comparable to the host drop is unclear yet. Thus, here we investigate the motion and spatial distribution of large particles within a sessile drop. The spherical particles cluster only when their initial distance is below a critical value, which is a function of the diameter and wettability of particle as well as the surface tension and size of the host drop. We rationalize such a critical distance for self-assembly based on the balance of the capillary force and the frictional resistance to sliding and rolling of the particles on a solid substrate. We further discuss the physical significance of this drop-mediated ``Cheerios effect'' in connection with the fate of pathogens residing in drops as a result of sneezing and coughing.

  18. Shedding of Water Drops from a Surface under Icing Conditions.

    Science.gov (United States)

    Mandal, Deepak Kumar; Criscione, Antonio; Tropea, C; Amirfazli, A

    2015-09-01

    A sessile water drop exposed to an air flow will shed if the adhesion is overcome by the external aerodynamic forces on the drop. In this study, shedding of water drops were investigated under icing conditions, on surfaces with different wettabilities, from hydrophilic to superhydrophobic. A wind tunnel was used for experiments in a temperature range between -8 and 24.5 °C. Results indicate that the temperature has a major influence on the incipient motion of drop shedding. The critical air velocity (U(c)) at which a drop first starts to shed generally increases under icing conditions, indicating an increase in the adhesion force. The contact angle hysteresis (CAH) and the drop base length (L(b)) are found to be the controlling factors for adhesion. A correlation was also developed to deduce the drag coefficient, C(D) for the drop. It was found that C(D) can decrease under icing conditions. In general, a lower C(D) and higher adhesion together lead to a higher critical air velocity. However, there are systems such as water on Teflon for which the critical air velocity remains practically unaffected by temperature because of similar adhesion and C(D) values, at all temperatures tested.

  19. Application of Proteomics to the Study of Pollination Drops

    Directory of Open Access Journals (Sweden)

    Natalie Prior

    2013-04-01

    Full Text Available Premise of the study: Pollination drops are a formative component in gymnosperm pollen-ovule interactions. Proteomics offers a direct method for the discovery of proteins associated with this early stage of sexual reproduction. Methods: Pollination drops were sampled from eight gymnosperm species: Chamaecyparis lawsoniana (Port Orford cedar, Ephedra monosperma, Ginkgo biloba, Juniperus oxycedrus (prickly juniper, Larix ×marschlinsii, Pseudotsuga menziesii (Douglas-fir, Taxus ×media, and Welwitschia mirabilis. Drops were collected by micropipette using techniques focused on preventing sample contamination. Drop proteins were separated using both gel and gel-free methods. Tandem mass spectrometric methods were used including a triple quadrupole and an Orbitrap. Results: Proteins are present in all pollination drops. Consistency in the protein complement over time was shown in L. ×marschlinsii. Representative mass spectra from W. mirabilis chitinase peptide and E. monosperma serine carboxypeptidase peptide demonstrated high quality results. We provide a summary of gymnosperm pollination drop proteins that have been discovered to date via proteomics. Discussion: Using proteomic methods, a dozen classes of proteins have been identified to date. Proteomics presents a way forward in deepening our understanding of the biological function of pollination drops.

  20. Modeling drop impacts on inclined flowing soap films

    Science.gov (United States)

    Basu, Saikat; Yawar, Ali; Concha, Andres; Bandi, Mahesh

    2015-11-01

    Small drops impinging on soap films flowing at an angle primarily exhibit three fundamental regimes of post-impact dynamics: (a) the drop bounces off the film surface, (b) it coalesces with the downstream flow, and (c) it pierces through the film. During impact, the drop deforms along with a simultaneous, almost elastic deformation of the film transverse to the stream direction. Hence, the governing dynamics for this interaction present the rare opportunity to explore the in-tandem effects of elasticity and hydrodynamics alike. In this talk, we outline the analytical framework to study the drop impact dynamics. The model assumes a deformable drop and a deformable three-dimensional soap film and invokes a parametric study to qualify the three mentioned impact types. The physical parameters include the impact angle, drop impact speed, and the diameters of the drop prior to and during impact when it deforms and spreads out. Our model system offers a path towards optimization of interactions between a spray and a flowing liquid.

  1. Pupil dilation using drops vs gel: a comparative study

    Science.gov (United States)

    Moisseiev, E; Loberman, D; Zunz, E; Kesler, A; Loewenstein, A; Mandelblum, J

    2015-01-01

    Purpose To compare the efficacy in pupil dilation and degree of discomfort between topical instillation of mydriatic drops and gel. Methods The study included 60 patients with no previous ocular history of trauma and surgery. One eye was dilated with two drops (tropicamide 0.5% and phenylephrine 10%), and the other with one drop of gel (tropicamide 0.5%+phenylephrine 5%). Pupil size was measured by a Colvard pupillometer at baseline and 5, 15, 30, and 45 min following instillation. Pain upon instillation was measured by visual analog scale (VAS). Results There was no difference in pupil size at baseline. Use of the gel achieved greater mydriasis than drops (P=0.01), and was also associated with lower pain scores (P=0.003). In diabetic patients, pupil size was smaller at baseline and following instillation of drops and gel. Use of the gel achieved an even greater degree of pupil dilation in this subset of patients than drops (P=0.019). Conclusions Gel formulation achieved significantly greater pupil dilation than drops, despite a lower concentration of phenylephrine, and was also associated with significantly lower patient discomfort. This study is the first report of improved mydriatic efficacy in diabetic patients. PMID:25857606

  2. Drop coalescence through a liquid/liquid interface

    Science.gov (United States)

    Mohamed-Kassim, Zulfaa; Longmire, Ellen K.

    2004-07-01

    Particle image velocimetry (PIV) experiments were conducted to study the coalescence of single drops through planar liquid/liquid interfaces. Sequences of velocity vector fields were obtained with a high-speed video camera and subsequent PIV analysis. Two ambient liquids with different viscosity but similar density were examined resulting in Reynolds numbers based on a surface tension velocity of 10 and 26. Prior to rupture, the drops rested on a thin film of ambient liquid above an underlying interface. After rupture, which was typically off-axis, the free edge of the thin film receded rapidly allowing the drop fluid to sink into the bulk liquid below. Vorticity generated in the collapsing fluid developed into a vortex ring straddling the upper drop surface. The ring core traveled radially inward with a ring-shaped capillary wave effectively pinching the upper drop surface and increasing the drop collapse speed. The inertia of the collapse deflected the interface downward before it rebounded upward. During this time, the vortex core split so that part of its initial vorticity moved inside the drop fluid while part remained in the ambient fluid above it. A second ring-shaped capillary wave formed along the interface outside of the drop and propagated radially outward during the collapse. Changing the ambient fluid viscosity resulted in several effects. First, the velocity of the receding free edge was smaller for higher ambient viscosity. Second, the pinching of the upper drop surface caused by the shrinking capillary ring wave was stronger when the ambient viscosity was lower, and this resulted in a higher maximum collapse speed and higher vorticity values in the dominant vortex ring.

  3. PERSAMAAN DROP SIZE DI DALAM KOLOM BERPENGADUK CAKRAM (RDC

    Directory of Open Access Journals (Sweden)

    Martunus Martunus

    2011-07-01

    Full Text Available Perpindahan massa dari satu fase cair ke fase cair lainnya di dalam kolom ekstraksi cair-cair ditentukan dengan luas perpindahan antara kedua fase. Luas perpindahan ini dapat dinyatakan dengan drop size yang merupakan faktor yang sangat penting dalam perancangan kolom ekstraksi cair-cair berpengaduk (Rotating Disc Contactor, RDC. Tiga model yang berhubungan dengan drop size dikembangkan untuk variabel operasi kolom yang didasarkan pada kecepatan putaran yaitu yaitu model untuk ekstraksi tanpa pengadukan atau pengadukan dengan putaran sangat rendah, model dengan kecepatan pengadukan medium, dan model pengadukan dengan putaran tinggi. Artikel ini berisi pembahasan persamaan drop size yang sudah dipublikasikan menyangkut ketiga kondisi operasi tersebut.

  4. Intelligent water drops for aerospace and defense applications

    Science.gov (United States)

    Straub, Jeremy

    2014-05-01

    A modified version of the intelligent water drop algorithm for performing planning for air and ground robots based on telemetry provided by satellites has been created. The IWD algorithm works by simulating the flow of water drops in a stream-network, dynamically adapting drop and network characteristics. This paper presents the base IWD algorithm, a simplified version of the algorithm (SIWD) and a derivative of this simplified version that has been adapted and applied to planning air and ground robot paths based upon orbital (for aerial) and aerial (for ground) imagery. An analysis of the performance of the algorithm is presented.

  5. Creeping motion of long bubbles and drops in capillary tubes

    DEFF Research Database (Denmark)

    Westborg, Henrik; Hassager, Ole

    1989-01-01

    at high capillary numbers. Furthermore the flow of a viscous drop through a doughnut shaped constriction in a capillary tube has been simulated. The simulations show that snap-off may be initiated by a sudden drop in the flow rate after the drops have protruded for some distance beyond the throat...... and the snap-off time increases with increasing capillary number. Snap-off without a sudden decrease of the flow rate does not seem to occur in constrictions of circular cross section....

  6. Partial coalescence of sessile drops with different liquids

    Science.gov (United States)

    Borcia, Rodica; Bestehorn, Michael

    2014-11-01

    We examine numerically the interaction between two deformable drops consisting of two perfectly miscible liquids sitting on a solid substrate under a given contact angle. Driven by solutal Marangoni forces, several distinct coalescence regimes are achieved after the droplets collision. Phase diagrams for different control parameters are emphasized, which give predictions about drop behavior along the solid substrates, control of various interfacial effects, manipulations of tiny droplets in micro- and nano-fluidic devices without power supply, design of droplets or cleaning surfaces. This work was partially supported by Deutsche Forschungsgemeinschaft (DFG) under the project ``Dynamics of interfaces between drops with miscible liquids''.

  7. Analysis of an Electrostatic MEMS Squeeze-film Drop Ejector

    Directory of Open Access Journals (Sweden)

    Edward P. Furlani

    2009-10-01

    Full Text Available We present an analysis of an electrostatic drop-on-demand MEMS fluid ejector. The ejector consists of a microfluidic chamber with a piston that is suspended a few microns beneath a nozzle plate. A drop is ejected when a voltage is applied between the orifice plate and the piston. This produces an electrostatic force that moves the piston towards the nozzle. The moving piston generates a squeeze-film pressure distribution that causes drop ejection. We discuss the operating physics of the ejector and present a lumped-element model for predicting its performance. We calibrate the model using coupled structural-fluidic CFD analysis.

  8. Ready-made allogeneic ABO-specific serum eye drops

    DEFF Research Database (Denmark)

    Harritshøj, Lene Holm; Nielsen, Connie; Ullum, Henrik

    2014-01-01

    PURPOSE: To overcome problems and delays of the preparation of autologous serum eye drops, a production line of ABO-specific allogeneic serum eye drops from male blood donors was set up in a blood bank. Feasibility, clinical routine, safety and efficacy were evaluated in a cohort of patients...... serum treatment. CONCLUSION: Ready-made ABO-identical allogeneic serum eye drops were straightforwardly produced, quality-assured and registered as a safe standard blood product for the treatment of certain cases of severe dry eye disease. Therapeutic efficacy was comparable to previous reports...

  9. Handling test of eye drop dispenser--comparison of unit-dose pipettes with conventional eye drop bottles.

    Science.gov (United States)

    Parkkari, Minna; Latvala, Terho; Ropo, Auli

    2010-06-01

    The aims of this study were to investigate how elderly people handle single-use eye drop dispensers (unit-dose pipettes) and to compare the performance with conventional eye drop bottles. In this open-label study, the handling of unit-dose pipettes and conventional eye drop bottles was compared in 41 elderly people who had little or no prior regular use of eye drop dispensers. The participants tested both types of dispenser once, and the following 7 variables were studied: ease/difficulty of opening the dispenser; influence of the size for handling of the dispenser; influence of the shape for handling of the dispenser; observation of the contents in the dispenser; the feeling of the dispenser in the hand; ease/difficulty of drop instillation on the eye from the dispenser; and overall performance of the eye drop dispenser. The dispensers contained isotonic saline, and a visual analog scale was used for assessment of each of the above variables. The mean age of the participants was 73 years. A statistically significant difference in favor of the unit-dose pipettes was found with respect to observation of the contents in the dispenser, ease of administration, and the overall performance. Women regarded the unit-dose pipettes generally better than the bottles, but such a difference was not seen in men. The study participants managed the unit-dose pipettes at least as well as the conventional eye drop bottles. If anything, the unit-dose pipettes appeared to be easier to use.

  10. Method and apparatus for producing drops using a drop-on-demand dispenser

    Science.gov (United States)

    Chen, Alvin U.; Basaran, Osman A.

    2003-01-01

    A method and apparatus for dispensing fluid from a drop-on-demand (DOD) fluid dispenser. The method involves withdrawing fluid in the dispenser for a first duration of time, followed by a second duration of time during which the fluid is propelled toward the orifice of the dispenser. Following the period during which the fluid is propelled, there is a second withdrawing of the fluid into the dispenser. The duration of the propelling period is shorter than the duration of either the first withdrawing or the second withdrawing. The propelling of the fluid results in the extension of a small tongue of fluid from the meniscus of the fluid. The second withdrawing of the fluid results in a retraction of the meniscus into the passageway such that only the small tongue of fluid separates and is ejected from the dispenser.

  11. Functional footprinting of regulatory DNA.

    Science.gov (United States)

    Vierstra, Jeff; Reik, Andreas; Chang, Kai-Hsin; Stehling-Sun, Sandra; Zhou, Yuanyue; Hinkley, Sarah J; Paschon, David E; Zhang, Lei; Psatha, Nikoletta; Bendana, Yuri R; O'Neil, Colleen M; Song, Alexander H; Mich, Andrea K; Liu, Pei-Qi; Lee, Gary; Bauer, Daniel E; Holmes, Michael C; Orkin, Stuart H; Papayannopoulou, Thalia; Stamatoyannopoulos, George; Rebar, Edward J; Gregory, Philip D; Urnov, Fyodor D; Stamatoyannopoulos, John A

    2015-10-01

    Regulatory regions harbor multiple transcription factor (TF) recognition sites; however, the contribution of individual sites to regulatory function remains challenging to define. We describe an approach that exploits the error-prone nature of genome editing-induced double-strand break repair to map functional elements within regulatory DNA at nucleotide resolution. We demonstrate the approach on a human erythroid enhancer, revealing single TF recognition sites that gate the majority of downstream regulatory function.

  12. Liquid Drop Pinning on Micro-patterned Surfaces

    Science.gov (United States)

    Soliman, Ahmed; Kalinin, Yevgeniy; Baur, Robin; Thorne, Robert

    2009-03-01

    Pinning of liquid drops on surfaces is important in many areas of biotechnology. Micro-patterned surfaces provide a way to control drop pinning, and to investigate the mechanisms of pinning on real (rough) surfaces. Continuous circular rings on silicon wafers produced by etching the interior and surrounding silicon are shown to dramatically increase contact line pinning. The critical apparent contact angles and liquid drop volumes are measured and correlated with parameters that describe the ring geometry, such as ring-wall height and width, as well as with ring surface energy (hydrophilicity / hydrophobicity). Micro-patterning of surfaces in this way can be used to improve drop pinning, shape reproducibility and imaging in high-throughput protein crystallization.

  13. Queues with Dropping Functions and General Arrival Processes.

    Science.gov (United States)

    Chydzinski, Andrzej; Mrozowski, Pawel

    2016-01-01

    In a queueing system with the dropping function the arriving customer can be denied service (dropped) with the probability that is a function of the queue length at the time of arrival of this customer. The potential applicability of such mechanism is very wide due to the fact that by choosing the shape of this function one can easily manipulate several performance characteristics of the queueing system. In this paper we carry out analysis of the queueing system with the dropping function and a very general model of arrival process--the model which includes batch arrivals and the interarrival time autocorrelation, and allows for fitting the actual shape of the interarrival time distribution and its moments. For such a system we obtain formulas for the distribution of the queue length and the overall customer loss ratio. The analytical results are accompanied with numerical examples computed for several dropping functions.

  14. Bird nesting and droppings control on highway structures.

    Science.gov (United States)

    2010-10-01

    This report provides a comprehensive literature survey of permanent and temporary deterrents to nesting and roosting, a : discussion of risks to human health and safety from exposure to bird nests and droppings and recommended protective measures, : ...

  15. Critical look at South Africa’s Green Drop Programme

    CSIR Research Space (South Africa)

    Ntombela, Cebile

    2016-10-01

    Full Text Available itself in. Challenges facing the Green Drop Programme and the municipalities implementing the programme include: lack of human resource capacity to prepare effective corrective action plans and/or wastewater risk abatement plans; lack of finances...

  16. Drop motion in a rotating immiscible liquid body

    Science.gov (United States)

    Annamalai, P.; Cole, R.

    1983-01-01

    The interaction of liquids is an important part of many processes and is often used for such purposes as causing a separation of solution components by mass transfer between phases, allowing a chemical reaction between liquids or their components, providing direct contact heating or cooling, or creating emulsions. Containerless space processing may well involve the interaction of liquids in the form of drops. For example it may be desirable to form an alloy in space by merger of two or more drops. Encapsulation of a volatile liquid by a second less volatile and immiscible liquid might be a means for avoiding volatilization. Rotation of such systems would enhance mixing where desirable and/or provide means for drop management. In this study, single drop behavior in rotating liquid bodies is studied experimentally.

  17. Satellite Formation during Coalescence of Unequal Size Drops

    KAUST Repository

    Zhang, F. H.

    2009-03-12

    The coalescence of a drop with a flat liquid surface pinches off a satellite from its top, in the well-known coalescence cascade, whereas the coalescence of two equally sized drops does not appear to leave such a satellite. Herein we perform experiments to identify the critical diameter ratio of two drops, above which a satellite is produced during their coalescence. We find that the critical parent ratio is as small as 1.55, but grows monotonically with the Ohnesorge number. The daughter size is typically about 50% of the mother drop. However, we have identified novel pinch-off dynamics close to the critical size ratio, where the satellite does not fully separate, but rather goes directly into a second stage of the coalescence cascade, thus generating a much smaller satellite droplet.

  18. Multiscale liquid drop impact on wettable and textured surfaces

    Science.gov (United States)

    Zhang, Rui; Farokhirad, Samaneh; Lee, Taehun; Koplik, Joel

    2014-08-01

    The impact of microscopic liquid drops on solids with a variety of surface characteristics is studied using numerical simulations. The focus is on relatively low impact velocities leading to bouncing or spreading drops, and the effects of wettability. Molecular dynamics and lattice Boltzmann simulation methods are used for nanometer-sized and continuum drops, respectively, and the results of the two methods are compared in terms of scaled variables. We consider surfaces which are flat, curved or pillared, with either homogeneous interactions or cross-shaped patterns of wettability. In most situations we observe similar drop behavior at both length scales; the two methods agree best at low impact velocities on wettable surfaces while discrepancies are most pronounced for strongly hydrophobic surfaces and for higher velocities.

  19. Modeling merging behavior at lane drops : [tech transfer summary].

    Science.gov (United States)

    2015-02-01

    A better understanding of the merging behavior of drivers will lead : to the development of better lane-drop traffic-control plans and : strategies, which will provide better guidance to drivers for safer : merging.

  20. Comparative evaluation of Nano-Hydroxyapatite preparation and Calcium Sucrose Phosphate on microhardness of deciduous teeth after iron drop exposure - An in-vitro study.

    Science.gov (United States)

    Rathi, Nilesh; Baid, Rutika; Baliga, Sudhindra; Thosar, Nilima

    2017-04-01

    To evaluate and compare the microhardness of deciduous teeth treated with nano-hydroxyapatite and calcium sucrose phosphate after iron drop exposure. Twenty healthy anterior deciduous teeth were collected and stored in 0.9% saline solution at room temperature. All the teeth were immersed in artificial saliva in an incubator shaker at 37° for an hour and then subjected to Vickers microhardness test at 100g load for 5 seconds. The teeth were then immersed in iron drop for 5 minutes, twice daily, rinsed with distilled water and kept in artificial saliva. This procedure was repeated for 7 days and teeth were subjected to microhardness testing. Further, the teeth were divided in two groups, each group containing 10 teeth. In group I, nanohydroxyapatite preparation and in group II, calcium sucrose phosphate were applied for 10 minutes, twice daily for 7 days and subjected again to microhardness testing again. Vickers microhardness analysis revealed that iron drop exposure to teeth caused significant decrease in microhardness (pcalcium sucrose phosphate in Group II showed significantly increased enamel microhardness (200.89) than that after iron drop exposure. Statistical difference was seen between the two groups, with nanohydroxyapatite preparation showing increased microhardness than calcium sucrose phosphate. Nanohydroxyapatite preparation and calcium sucrose phosphate have remineralizing effect over teeth affected by acid challenge of iron drops, nanohydroxyapatite preparation showing better results than calcium sucrose phosphate. Key words:Iron drops, Nanohydroxyapaptite, calcium sucrose phosphate, anticay.

  1. What explains Rwanda's drop in fertility between 2005 and 2010 ?

    OpenAIRE

    Bundervoet, Tom

    2014-01-01

    Following a decade-and-a-half stall, fertility in Rwanda dropped sharply between 2005 and 2010. Using a hierarchical age-period-cohort model, this paper finds that the drop in fertility is largely driven by cohort effects, with younger cohorts having substantially fewer children than older cohorts observed at the same age. An Oaxaca-Blinder decomposition is applied on two successive rounds...

  2. Nectar and pollination drops: how different are they?

    Science.gov (United States)

    Nepi, Massimo; von Aderkas, Patrick; Wagner, Rebecca; Mugnaini, Serena; Coulter, Andrea; Pacini, Ettore

    2009-08-01

    Pollination drops and nectars (floral nectars) are secretions related to plant reproduction. The pollination drop is the landing site for the majority of gymnosperm pollen, whereas nectar of angiosperm flowers represents a common nutritional resource for a large variety of pollinators. Extrafloral nectars also are known from all vascular plants, although among the gymnosperms they are restricted to the Gnetales. Extrafloral nectars are not generally involved in reproduction but serve as 'reward' for ants defending plants against herbivores (indirect defence). Although very different in their task, nectars and pollination drops share some features, e.g. basic chemical composition and eventual consumption by animals. This has led some authors to call these secretions collectively nectar. Modern techniques that permit chemical analysis and protein characterization have very recently added important information about these sugary secretions that appear to be much more than a 'reward' for pollinating (floral nectar) and defending animals (extrafloral nectar) or a landing site for pollen (pollination drop). Nectar and pollination drops contain sugars as the main components, but the total concentration and the relative proportions are different. They also contain amino acids, of which proline is frequently the most abundant. Proteomic studies have revealed the presence of common functional classes of proteins such as invertases and defence-related proteins in nectar (floral and extrafloral) and pollination drops. Invertases allow for dynamic rearrangement of sugar composition following secretion. Defence-related proteins provide protection from invasion by fungi and bacteria. Currently, only few species have been studied in any depth. The chemical composition of the pollination drop must be investigated in a larger number of species if eventual phylogenetic relationships are to be revealed. Much more information can be provided from further proteomic studies of both

  3. Refrigeration. Two-Phase Flow. Flow Regimes and Pressure Drop

    DEFF Research Database (Denmark)

    Knudsen, Hans-Jørgen Høgaard

    2002-01-01

    The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature.......The note gives the basic definitions used in two-phase flow. Flow regimes and flow regimes map are introduced. The different contributions to the pressure drop are stated together with an imperical correlation from the litterature....

  4. 76 FR 3825 - Regulatory Compliance

    Science.gov (United States)

    2011-01-21

    ... Documents#0;#0; ] Memorandum of January 18, 2011 Regulatory Compliance Memorandum for the Heads of Executive... accessible to the public, information concerning their regulatory compliance and enforcement activities, such... enforcement actions). Greater disclosure of regulatory compliance information fosters fair and consistent...

  5. Characteristics of regulatory regimes

    Directory of Open Access Journals (Sweden)

    Noralv Veggeland

    2013-03-01

    Full Text Available The overarching theme of this paper is institutional analysis of basic characteristics of regulatory regimes. The concepts of path dependence and administrative traditions are used throughout. Self-reinforcing or positive feedback processes in political systems represent a basic framework. The empirical point of departure is the EU public procurement directive linked to OECD data concerning use of outsourcing among member states. The question is asked: What has caused the Nordic countries, traditionally not belonging to the Anglo-Saxon market-centred administrative tradition, to be placed so high on the ranking as users of the Market-Type Mechanism (MTM of outsourcing in the public sector vs. in-house provision of services? A thesis is that the reason may be complex, but might be found in an innovative Scandinavian regulatory approach rooted in the Nordic model.

  6. Drop formation of black liquor spraying; Mustalipeaen pisaroituminen

    Energy Technology Data Exchange (ETDEWEB)

    Fogelholm, C.J.; Kankkunen, A.; Nieminen, K.; Laine, J.; Miikkulainen, P. [Helsinki Univ. of Technology, Otaniemi (Finland): Lab. of Energy Technology and Environmental Protection

    1997-10-01

    Black liquor is a spent liquor of the pulp and paper industry. It is burned in kraft recovery boilers for chemical and energy recovery. The high dry solids content and viscosity of black liquor require a high spraying temperature. This affects the performance of the boiler. Kraft recovery boiler deposit formation, emissions and chemical recovery are strongly affected by the drop size and the velocity of the black liquor spray formed by a splashplate nozzle. The sheet breakup mechanism is studied with a system based on a video and image-analysis. The drop size of mill-scale nozzles was measured also with an image-analysis-system. Measurements were carried out in a spray test chamber. The sheet breakup mechanism and drop size tests were carried out both below and over the boiling point of black liquor. Special attention was paid to the effect of flashing on drop formation. Temperature increase normally decreases drop size. In the temperature where the wavy-sheet disintegration changes to perforated-sheet disintegration the drop size increases. Spray velocity rises when the temperature is increased above the boiling point. (orig.)

  7. Wetting of sessile water drop under an external electrical field

    Science.gov (United States)

    Vancauwenberghe, Valerie; di Marco, Paolo; Brutin, David; Amu Collaboration; Unipi Collaboration

    2013-11-01

    The enhancement of heat and mass transfer using a static electric field is an interesting process for industrial applications, due to its low energy consumption and potentially high level of evaporation rate enhancement. However, to date, this phenomenon is still not understood in the context of the evaporation of sessile drops. We previously synthesized the state of the art concerning the effect of an electric field on sessile drops with a focus on the change of contact angle and shape and the influence of the evaporation rate [1]. We present here the preliminary results of an new experiment set-up. The novelty of the set-up is the drop injection from the bottom that allows to generate safety the droplet under the electrostatic field. The evaporation at room temperature of water drops having three different volumes has been investigated under an electric field up to 10.5 kV/cm. The time evolutions of the contact angles, volumes and diameters have been analysed. As reported in the literature, the drop elongate along the direction of the electric field. Despite the hysteresis effect of the contact angle, the receding contact angle increases with the strength of the electric field. This is clearly observable for the small drops for which the gravity effect can be neglected.

  8. Vortex-ring-induced large bubble entrainment during drop impact

    Science.gov (United States)

    Thoraval, Marie-Jean; Li, Yangfan; Thoroddsen, Sigurdur T.

    2016-03-01

    For a limited set of impact conditions, a drop impacting onto a pool can entrap an air bubble as large as its own size. The subsequent rise and rupture of this large bubble plays an important role in aerosol formation and gas transport at the air-sea interface. The large bubble is formed when the impact crater closes up near the pool surface and is known to occur only for drops that are prolate at impact. Herein we use experiments and numerical simulations to show that a concentrated vortex ring, produced in the neck between the drop and the pool, controls the crater deformations and pinchoff. However, it is not the strongest vortex rings that are responsible for the large bubbles, as they interact too strongly with the pool surface and self-destruct. Rather, it is somewhat weaker vortices that can deform the deeper craters, which manage to pinch off the large bubbles. These observations also explain why the strongest and most penetrating vortex rings emerging from drop impacts are not produced by oblate drops but by more prolate drop shapes, as had been observed in previous experiments.

  9. [Preparation of Shuxiong pulsatile controlled-release dropping pill].

    Science.gov (United States)

    Chen, Hui; Chen, Yan-Zhong; Xie, Qing-Chun; Lin, Shi-Yuan; Lin, Jia-Cheng; Jianc, Wei-Ning

    2013-07-01

    To prepare Shuxiong pulsatile controlled-release dropping pill and study the influencing factors in vitro. Dropping pills with suitable size (10 - 15 mg) were coated with swelling layer containing croscarmellose sodium and controlled-release layer containing ethylcellulos aqueous dispersion respectively to prepare Shuxiong pulsatile controlled-release dropping pill. The effects of the materials of swelling layer, the weight of swelling layer and controlled-release layer on the release of drugs were investigated to optimize the process technology and validate formula. The release behavior was influenced strikingly by the types and weight of coating layer. The optimal formula was as follows: Shuxiong pulsatile controlled-release dropping pills were prepared using croscarmellose sodium as inner layer with 15% (weight) coating level and ethylcellulose aqueous dispersion (Surelease) as outer controlled-release layer with 7% (weight) coating level. The lag time of prepared pulsatile controlled-release dropping pills was about 4 h and accumulative release rate reached 80% within 4 h. The drug release of Shuxiong pulsatile controlled-release dropping pill is shown in pulsatile way in vitro.

  10. Afterlife of a Drop Impacting a Liquid Pool

    Science.gov (United States)

    Saha, Abhishek; Wei, Yanju; Tang, Xiaoyu; Law, Chung K.

    2017-11-01

    Drop impact on liquid pool is ubiquitous in industrial processes, such as inkjet printing and spray coating. While merging of drop with the impacted liquid surface is essential to facilitate the printing and coating processes, it is the afterlife of this merged drop and associated mixing which control the quality of the printed or coated surface. In this talk we will report an experimental study on the structural evolution of the merged droplet inside the liquid pool. First, we will analyze the depth of the crater created on the pool surface by the impacted drop for a range of impact inertia, and we will derive a scaling relation and the associated characteristic time-scale. Next, we will focus on the toroidal vortex formed by the moving drop inside the liquid pool and assess the characteristic time and length scales of the penetration process. The geometry of the vortex structure which qualitatively indicates the degree of mixedness will also be discussed. Finally, we will present the results from experiments with various viscosities to demonstrate the role of viscous dissipation on the geometry and structure formed by the drop. This work is supported by the Army Research Office and the Xerox Corporation.

  11. Numerical simulations of drop impact on superhydrophobic structured surfaces

    Science.gov (United States)

    Guzzetti, Davide; Larentis, Stefano; Pugno, Nicola

    2011-11-01

    During the last decade drop impact dynamics on superhydrophobic surfaces has been intensively investigated because of the incredible properties of water repellency exhibited by this kind of surfaces, mostly inspired by biological examples such as Lotus leave. Thanks to the recent progress in micro-fabrication technology is possible to tailor surfaces wettability defining specific pillar-like structured surfaces. In this work, the behavior of impinging drops on these pillar-like surfaces is simulated, characterizing temporal evolution of droplets contact radius and drop maximal deformation dependence on Weber number. Numerical simulations results are compared with theoretical and experimental results guaranteeing simulation reliability. Fingering patterns obtained from drop impact has been studied obtaining a correlation between number of fingers and Weber number. Drop fragmentation pattern obtained from simulations supports the proposed correlation. Different drop impact outcomes (e.g. rebound, fragmentation) on structured superhydrophobic surfaces are simulated, focusing on the influence of micro-structured surface geometrical pattern. This investigation is relevant in order to define design rules for possible reliable non wettable surfaces. Financial support by Alta Scuola Politecnica.

  12. Capillary-Inertial Colloidal Catapult upon Drop Coalescence

    Science.gov (United States)

    Chavez, Roger; Liu, Fangjie; Feng, James; Chen, Chuan-Hua

    2014-11-01

    To discharge micron-sized particles such as colloidal contaminants and biological spores, an enormous power density is needed to compete against the strong adhesive forces between the small particles and the supporting surface as well as the significant air friction exerted on the particles. Here, we demonstrate a colloidal catapult that achieves such a high power density by extracting surface energy released upon drop coalescence within an extremely short time period, which is governed by the capillary-inertial process converting the released surface energy into the bulk inertia of the merged drop. When two drops coalesce on top of a spherical particle, the resulting capillary-inertial oscillation is perturbed by the solid particle, giving rise to a net momentum eventually propelling the particle to launch from the supporting surface. The measured launching velocity follows a scaling law that accounts for the redistribution of the momentum of the merged drop onto the particle-drop complex, and is therefore proportional to the capillary-inertial velocity characterizing the coalescing drops. The interfacial flow process associated with the colloidal catapult is elucidated with both high-speed imaging and phase-field simulations.

  13. A measurement of a control rod drop using an LVDT

    Science.gov (United States)

    Choi, Myoung-Hwan; Kim, Ji-Ho; Huh, Hyung; Yu, Je-Yong; Sohn, Dong-Seong

    2010-03-01

    A control element drive mechanism is a reactor regulating system, which is to insert, withdraw, or maintain a control rod containing neutron-absorbing material within a reactor core to control the reactivity of the reactor. The ball-screw type CEDM for the small and medium research reactor has a spring-hydraulic damper to reduce the impact force due to the free drop of the CEDM. This paper describes the experimental results to obtain the drop characteristics of the CEDM. The tests are performed by using a full-scale structure except the control element assembly, and a drop time and displacement after an impact are measured by using an LVDT. The influences of the rod weight and the drop height on the drop behavior are also estimated on the basis of test results. In case of the longest stroke, the drop time of the control rod is within 4.5 seconds to meet the design requirement. The behavior after the impact shows a general damping motion of the spring-damper system, and the maximum displacement is measured as 15.6 mm.

  14. Short Duration Reduced Gravity Drop Tower Design and Development

    Science.gov (United States)

    Osborne, B.; Welch, C.

    The industrial and commercial development of space-related activities is intimately linked to the ability to conduct reduced gravity research. Reduced gravity experimentation is important to many diverse fields of research in the understanding of fundamental and applied aspects of physical phenomena. Both terrestrial and extra-terrestrial experimental facilities are currently available to allow researchers access to reduced gravity environments. This paper discusses two drop tower designs, a 2.0 second facility built in Australia and a proposed 2.2 second facility in the United Kingdom. Both drop towers utilise a drag shield for isolating the falling experiment from the drag forces of the air during the test. The design and development of The University of Queensland's (Australia) 2.0 second drop tower, including its specifications and operational procedures is discussed first. Sensitive aspects of the design process are examined. Future plans are then presented for a new short duration (2.2 sec) ground-based reduced gravity drop tower. The new drop tower has been designed for Kingston University (United Kingdom) to support teaching and research in the field of reduced gravity physics. The design has been informed by the previous UQ drop tower design process and utilises a catapult mechanism to increase test time and also incorporates features to allow participants for a variety of backgrounds (from high school students through to university researchers) to learn and experiment in reduced gravity. Operational performance expectations for this new facility are also discussed.

  15. Vortex-ring-induced large bubble entrainment during drop impact

    KAUST Repository

    Thoraval, Marie-Jean

    2016-03-29

    For a limited set of impact conditions, a drop impacting onto a pool can entrap an air bubble as large as its own size. The subsequent rise and rupture of this large bubble plays an important role in aerosol formation and gas transport at the air-sea interface. The large bubble is formed when the impact crater closes up near the pool surface and is known to occur only for drops that are prolate at impact. Herein we use experiments and numerical simulations to show that a concentrated vortex ring, produced in the neck between the drop and the pool, controls the crater deformations and pinchoff. However, it is not the strongest vortex rings that are responsible for the large bubbles, as they interact too strongly with the pool surface and self-destruct. Rather, it is somewhat weaker vortices that can deform the deeper craters, which manage to pinch off the large bubbles. These observations also explain why the strongest and most penetrating vortex rings emerging from drop impacts are not produced by oblate drops but by more prolate drop shapes, as had been observed in previous experiments.

  16. Regulatory functions of microtubules.

    Science.gov (United States)

    Vasiliev, J M; Samoylov, V I

    2013-01-01

    This mini-review summarizes literature and original data about the role of microtubules in interphase animal cells. Recent data have shown that functioning of microtubules is essential for such diverse phenomena as directional cell movements, distribution of organelles in the cytoplasm, and neuronal memory in the central nervous system. It is suggested that microtubules can act as an important regulatory system in eukaryotic cells. Possible mechanisms of these functions are discussed.

  17. Regulatory aspects on nanomedicines.

    Science.gov (United States)

    Sainz, Vanessa; Conniot, João; Matos, Ana I; Peres, Carina; Zupancic, Eva; Moura, Liane; Silva, Liana C; Florindo, Helena F; Gaspar, Rogério S

    2015-12-18

    Nanomedicines have been in the forefront of pharmaceutical research in the last decades, creating new challenges for research community, industry, and regulators. There is a strong demand for the fast development of scientific and technological tools to address unmet medical needs, thus improving human health care and life quality. Tremendous advances in the biomaterials and nanotechnology fields have prompted their use as promising tools to overcome important drawbacks, mostly associated to the non-specific effects of conventional therapeutic approaches. However, the wide range of application of nanomedicines demands a profound knowledge and characterization of these complex products. Their properties need to be extensively understood to avoid unpredicted effects on patients, such as potential immune reactivity. Research policy and alliances have been bringing together scientists, regulators, industry, and, more frequently in recent years, patient representatives and patient advocacy institutions. In order to successfully enhance the development of new technologies, improved strategies for research-based corporate organizations, more integrated research tools dealing with appropriate translational requirements aiming at clinical development, and proactive regulatory policies are essential in the near future. This review focuses on the most important aspects currently recognized as key factors for the regulation of nanomedicines, discussing the efforts under development by industry and regulatory agencies to promote their translation into the market. Regulatory Science aspects driving a faster and safer development of nanomedicines will be a central issue for the next years. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Many Drops Interactions I: Simulation of Coalescence, Flocculation and Fragmentation of Multiple Colliding Drops with Smoothed Particle Hydrodynamics

    Directory of Open Access Journals (Sweden)

    Alejandro Acevedo-Malavé

    2012-06-01

    Full Text Available Smoothed Particle Hydrodynamics (SPH is a Lagrangian mesh-free formalism and has been useful to model continuous fluid. This formalism is employed to solve the Navier-Stokes equations by replacing the fluid with a set of particles. These particles are interpolation points from which properties of the fluid can be determined. In this study, the SPH method is applied to simulate the hydrodynamics interaction of many drops, showing some settings for the coalescence, fragmentation and flocculation problem of equally sized liquid drops in three-dimensional spaces. For small velocities the drops interact only through their deformed surfaces and the flocculation of the droplets arises. This result is very different if the collision velocity is large enough for the fragmentation of droplets takes place. We observe that for velocities around 15 mm/ms the coalescence of droplets occurs. The velocity vector fields formed inside the drops during the collision process are shown.

  19. Effect of Drop Foot on Spatiotemporal, Kinematic, and Kinetic Parameters during Gait

    Directory of Open Access Journals (Sweden)

    Ida Wiszomirska

    2017-01-01

    Full Text Available Background. The complexity of the structure and function of a living body can be affected by disorders and can cause various dysfunctions. Objective. The aim of this study was to determine compensatory mechanisms in subjects with drop foot during gait. Methods. The study evaluated 10 subjects with drop foot (DF whose results were compared to a group of 10 healthy controls (C. Spatiotemporal, kinematic, and kinetic parameters during the gait cycle were collected using Vicon system synchronized with Kistler platforms. Results. Spatiotemporal, kinematic, and kinetic parameters were significantly different between the analysed groups. In the DF group, the subjects walked almost 47% slower and performed 60% less steps per minute compared to the C group. The main problem in the DF group was insufficient ankle dorsiflexion in the 0–10% of the gait cycle. Mean values in the groups during the first 10% of the gait cycle were as follows: DF (−10.42 ± 5.7° and C (−2.37 ± 1.47°, which affected the substantial differences in the values of muscle torque: DF (0.2 ± 0.1 Nm/kg and C (−0.26 ± 0.06 Nm/kg. Conclusions. Comparative analysis for joint angles and torques demonstrated that the mechanism of compensation is the most noticeable in the knee joint and less in the hip joint.

  20. Ring-Sheared Drop (RSD): Microgravity Module for Containerless Flow Studies

    Science.gov (United States)

    Gulati, Shreyash; Raghunandan, Aditya; Rasheed, Fayaz; McBride, Samantha A.; Hirsa, Amir H.

    2017-02-01

    Microgravity is potentially a powerful tool for investigating processes that are sensitive to the presence of solid walls, since fluid containment can be achieved by surface tension. One such process is the transformation of protein in solution into amyloid fibrils; these are protein aggregates associated with neurodegenerative diseases such as Alzheimer's and Parkinson's. In addition to solid walls, experiments with gravity are also subject to influences from sedimentation of aggregates and buoyancy-driven convection. The ring-sheared drop (RSD) module is a flow apparatus currently under development to study formation of amyloid fibrils aboard the International Space Station (ISS). A 25 mm diameter drop of protein solution will be contained by surface tension and constrained by a pair of sharp-edged tubes, forming two contact rings. Shear can be imparted by rotating one ring with the other ring kept stationary. Here we report on parabolic flights conducted to test the growth and pinning of 10 mm diameter drops of water in under 10 s of microgravity. Finite element method (FEM) based fluid dynamics computations using a commercial package (COMSOL) assisted in the design of the parabolic flight experiments. Prior to the parabolic flights, the code was validated against experiments in the lab (1 g), on the growth of sessile and pendant droplets. The simulations show good agreement with the experiments. This modeling capability will enable the development of the RSD at the 25 mm scale for the ISS.

  1. Definitive foot drop deformity repair with tensor fascia latae myocutaneous flap.

    Science.gov (United States)

    Karagöz, Hüseyin; Öksüz, Sinan; Ülkür, Ersin; Sever, Celalettin; Şahin, Cihan; Külahçi, Yalçin

    2013-03-01

    Tensor fascia latae (TFL) myocutaneous flap, utilized as a novel approach for the successful functional repair of the foot drop deformity is presented in this case report. A 21-year-old male patient was subjected to a close-range high-velocity gunshot injury and sustained comminuted Gustillo-type IIIB open fracture of his left tibia. A composite skin and soft tissue defect including tibialis anterior and extansor hallucis longus tendons was determined. The injury was managed in two stages. In the first stage, the immediate reconstruction of the open tibia fracture was provided by using a reverse flow sural flap and external fixation of the fracture. The functional restoration was achieved by vascular fascia latae in the second stage, 6 months after the initial skin, soft tissue, and bone defect repair. The functional recovery was successful, and the foot drop gait was almost totally ameliorated. Reconstruction with TFL flap should be retained in the armamentarium for the functional repair of the foot drop deformity, caused by composite skin and soft tissue defects of the pretibial region. Copyright © 2012 Wiley Periodicals, Inc.

  2. Assessment of fall-arrest systems for scissor lift operators: computer modeling and manikin drop testing.

    Science.gov (United States)

    Pan, Christopher S; Powers, John R; Hartsell, Jared J; Harris, James R; Wimer, Bryan M; Dong, Renguang G; Wu, John Z

    2012-06-01

    The current study is intended to evaluate the stability of a scissor lift and the performance of various fall-arrest harnesses/lanyards during drop/fall-arrest conditions and to quantify the dynamic loading to the head/ neck caused by fall-arrest forces. No data exist that establish the efficacy of fall-arrest systems for use on scissor lifts or the injury potential from the fall incidents using a fall-arrest system. The authors developed a multibody dynamic model of the scissor lift and a human lift operator model using ADAMS and LifeMOD Biomechanics Human Modeler. They evaluated lift stability for four fall-arrest system products and quantified biomechanical impacts on operators during drop/fall arrest, using manikin drop tests. Test conditions were constrained to flat surfaces to isolate the effect of manikin-lanyard interaction. The fully extended scissor lift maintained structural and dynamic stability for all manikin drop test conditions. The maximum arrest forces from the harnesses/lanyards were all within the limits of ANSI Z359.1. The dynamic loading in the lower neck during the fall impact reached a level that is typically observed in automobile crash tests, indicating a potential injury risk for vulnerable participants. Fall-arrest systems may function as an effective mechanism for fall injury protection for operators of scissor lifts. However, operators may be subjected to significant biomechanical loadings on the lower neck during fall impact. Results suggest that scissor lifts retain stability under test conditions approximating human falls from predefined distances but injury could occur to vulnerable body structures.

  3. Evaluation of potentiating effect of a drop of lignocaine on tropicamide-induced mydriasis.

    Science.gov (United States)

    Ghose, S; Garodia, V K; Sachdev, M S; Kumar, H; Biswas, N R; Pandey, R M

    2001-06-01

    To analyze whether preinstillation of lignocaine potentiates mydriasis by tropicamide in dark eyes and to determine possible mechanisms for this effect. This investigation was conducted in two phases, the first being a double-masked, placebo-controlled, randomized clinical trial, enrolling 60 healthy dark brown eyes in 30 subjects aged 7 to 58 years. The control eye received a drop of (nonlignocaine) placebo before tropicamide 1%, and the contralateral study eye received a 4% lignocaine drop 3-minutes before the 1 drop of tropicamide was administered. A ruled pupillometer recorded pupil diameters every 10 minutes for 50 minutes. In phase II, to elucidate pathomechanisms after lignocaine, corneal and tear parameters were compared with baseline records in a further 60 such eyes. Pupillary diameters in the study eyes increased by 3.62 +/- 0.75 mm, significantly more than in the placebo (control) group (P = 0.000). Ninety percent of study eyes attained the clinically significant 6-mm size with preinstillation of lignocaine-many more than the 67% of control eyes (P = 0.016). The median time to achieve this critical 6-mm size was significantly faster in the study group (P = 0.005). In phase II, the 1 drop 4% lignocaine did not show corneal changes with slit lamp or fluorescein staining and did not reduce media clarity or induce a significant change in tear pH. It markedly decreased Schirmer values (P = 0.000), reduced tear break-up time (P = 0.003), and increased corneal thickness measured by optical pachymetry (P = 0.010). The phase II findings indicate corneal microepithelial damage and reduced tearing. Both may enhance intraocular penetration and hence potentiation of tropicamide. This remarkable phenomenon could find use with many other important topical medications.

  4. Response of laminated composite plates to low-speed impact by airgun-propelled and dropped-weight impactors

    Science.gov (United States)

    Prasad, Chunchu B.; Ambur, Damodar R.; Starnes, James H., Jr.

    1993-01-01

    An analytical procedure has been developed to determine the transient response of simply supported, rectangular laminated composite plates subjected to impact loads from airgun-propelled or dropped-weight impactors. A first-order shear-deformation theory has been included in the analysis to represent properly any local short-wavelength transient bending response. The impact force has been modeled as a locally distributed load with a cosine-cosine distribution. A double Fourier series expansion and the Timoshenko small increment method have been used to determine the contact force, out-of-plane deflections, and inplane strains and stresses at any plate location due to an impact force at any plate location. The results of experimental and analytical studies are compared for quasi-isotropic laminates. The results indicate the importance of including transverse shear deformation effects in the analysis for predicting the response of laminated plates subjected to both airgun-propelled and dropped-weight impactors. The results also indicate that plate boundary conditions influence the axial strains more significantly than the contact force for a dropped-weight impactor. The results of parametric studies identify a scaling approach based on impactor momentum that suggests an explanation for the differences in the responses of plates impacted by airgun-propelled or dropped-weight impactors.

  5. Drop-On-Drop Multimaterial 3D Bioprinting Realized by Peroxidase-Mediated Cross-Linking.

    Science.gov (United States)

    Sakai, Shinji; Ueda, Kohei; Gantumur, Enkhtuul; Taya, Masahito; Nakamura, Makoto

    2017-12-11

    A cytocompatible inkjet bioprinting approach that enables the use of a variety of bioinks to produce hydrogels with a wide range of characteristics is developed. Stabilization of bioinks is caused by horseradish peroxidase (HRP)-catalyzed cross-linking consuming hydrogen peroxide (H2 O2 ). 3D cell-laden hydrogels are fabricated by the sequential dropping of a bioink containing polymer(s) cross-linkable through the enzymatic reaction and H2 O2 onto droplets of another bioink containing the polymer, HRP, and cells. The ≈95% viability of enclosed mouse fibroblasts and subsequent elongation of the cells in a bioprinted hydrogel consisting of gelatin and hyaluronic acid derivatives suggest the high cytocompatibility of the developed printing approach. The existence of numerous polymers, including derivatives of polysaccharides, proteins, and synthetic polymers, cross-linkable through the HRP-catalyzed reaction, means the current approach shows great promise for biofabrication of functional and structurally complex tissues. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Vaporization response of evaporating drops with finite thermal conductivity

    Science.gov (United States)

    Agosta, V. D.; Hammer, S. S.

    1975-01-01

    A numerical computing procedure was developed for calculating vaporization histories of evaporating drops in a combustor in which travelling transverse oscillations occurred. The liquid drop was assumed to have a finite thermal conductivity. The system of equations was solved by using a finite difference method programmed for solution on a high speed digital computer. Oscillations in the ratio of vaporization of an array of repetitivity injected drops in the combustor were obtained from summation of individual drop histories. A nonlinear in-phase frequency response factor for the entire vaporization process to oscillations in pressure was evaluated. A nonlinear out-of-phase response factor, in-phase and out-of-phase harmonic response factors, and a Princeton type 'n' and 'tau' were determined. The resulting data was correlated and is presented in graphical format. Qualitative agreement with the open literature is obtained in the behavior of the in-phase response factor. Quantitatively the results of the present finite conductivity spray analysis do not correlate with the results of a single drop model.

  7. Underwater sound produced by individual drop impacts and rainfall

    DEFF Research Database (Denmark)

    Pumphrey, Hugh C.; Crum, L. A.; Jensen, Leif Bjørnø

    1989-01-01

    in the frequency range 14–16 kHz. These peaks have been observed by several scientists during measurements of real rain. Our findings provide evidence for the theory that the 14- to 16-kHz spectral peak is caused by the ringing of bubbles entrained in the water by the drop impact process.......An experimental study of the underwater sound produced by water drop impacts on the surface is described. It is found that sound may be produced in two ways: first when the drop strikes the surface and, second, when a bubble is created in the water. The first process occurs for every drop......; the second occurs for some impacts but not others. A range of conditions is described in which a bubble is produced for every drop impact, and it is shown that these conditions are likely to be met by a significant fraction of the raindrops in a typical shower. Underwater sound produced by artificial as well...

  8. Mapping coalescence of micron-sized drops and bubbles.

    Science.gov (United States)

    Berry, Joseph D; Dagastine, Raymond R

    2017-02-01

    Emulsion formulation, solvent extraction and multiphase microfluidics are all examples of processes that require precise control of drop or bubble collision stability. We use a previously validated numerical model to map the exact conditions under which micron-sized drops or bubbles undergo coalescence in the presence of colloidal forces and hydrodynamic effects relevant to Brownian motion and low Reynolds number flows. We demonstrate that detailed understanding of how the equilibrium surface forces vary with film thickness can be applied to make accurate predictions of the outcome of a drop or bubble collision when hydrodynamic effects are negligible. In addition, we illuminate the parameter space (i.e. interaction velocity, drop deformation, interfacial tension, etc.) at which hydrodynamic effects can stabilise collisions that are unstable at equilibrium. Further, we determine conditions for which drop or bubble collisions become unstable upon separation, caused by negative hydrodynamic pressure in the film. Lastly, we show that scaling analyses are not applicable for constant force collisions where the approach timescale is comparable to the coalescence timescale, and demonstrate that initial conditions under these circumstances cannot be ignored. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Vertical Drop Test of a YS-11 Fuselage Section

    Science.gov (United States)

    Minegishi, Masakatsu; Kumakura, Ikuo; Iwasaki, Kazuo; Shoji, Hirokazu; Yoshimoto, Norio; Terada, Hiroyuki; Sashikuma, Hirofumi; Isoe, Akira; Yamaoka, Toshihiro; Katayama, Noriaki; Hayashi, Toru; Akaso, Tetsuya

    The Structures and Materials Research Center of the National Aerospace Laboratory of Japan (NAL) and Kawasaki Heavy Industories, Ltd. (KHI) conducted a vertical drop test of a fuselage section cut from a NAMIC YS-11 transport airplane at NAL vertical drop test facility in December 2001. The main objectives of this program were to obtain background data for aircraft cabin safety by drop test of a full-scale fuselage section and to develop computational method for crash simulation. The test article including seats and anthropomorphic test dummies was dropped to a rigid impact surface at a velocity of 6.1 m/s (20 ft/s). The test condition and result were considered to be severe but potentially survivable. A finite element model of this test article was also developed using the explicit nonlinear transient-dynamic analysis code, LS-DYNA3D. An outline of analytical method and comparison of analysis result with drop test data are presented in this paper.

  10. Dynamics of viscous drops confined in a rough medium

    Science.gov (United States)

    Keiser, Ludovic; Gas, Armelle; Jaafar, Khalil; Bico, Jose; Reyssat, Etienne

    2017-11-01

    We focus on the dynamics of viscous and non-wetting ``pancake'' droplets of oil conned in a vertical Hele-Shaw cell filled with a less viscous surfactant solution. These dense drops settle at constant velocity driven by gravity. The surfactant solution completely wets the walls, and a thin lubrication film separates the drops from the walls. With smooth walls, two main dynamical regimes are characterized as the gap between the walls is varied. Viscous dissipation is found to dominate either in the droplet or in the lubrication film, depending on the ratio of viscosities and length scales. A sharp transition between both regimes is observed and successfully captured by asymptotic models. With rough walls, that transition is dramatically altered. Drops are generally much slower in a rough Hele-Shaw cell, in comparison with a similar smooth cell. Building up on the seminal works of Seiwert et al. (J.F.M. 2011) on film deposition by dip coating on a rough surface, we shed light on the non-trivial friction processes resulting from the interplay of viscous dissipation at the front of the drop, in the lubrication film and in the bulk of the drop. We acknowledge funding from Total S.A.

  11. Drop fragmentation by laser-induced cavitation bubbles

    Science.gov (United States)

    Gonzalez-A, S. Roberto; Kerssens, Pjotr; Ohl, Claus-Dieter

    2015-11-01

    The fragmentation of water droplets by a short laser pulse has received significant attention since the 70's. The fundamental understanding of droplet vaporization/fragmentation is of interest in laser beam propagation in the atmosphere, in situ analysis of combustion products -a great concern due to its ecological implications- and more recently driven by a better understanding of the drop shaping by a laser pulse which is of interest in the development of extreme ultraviolet (EUV) machines. In this presentation we discuss about the incipient events that lead to the fragmentation of a drop produced by a cavitation bubble. When the bubble expands, it stretches the drop into a thin liquid film; this liquid film is eventually ruptured and a shockwave and small droplets are ejected as fast as 4 times the speed of sound in air. Interestingly, we also observe bubbles on the surface of the stretched film. Numerical simulations of a shock wave propagating inside a droplet show that cavitation bubbles appear when counter propagating shock waves that rebound from the walls of the drop meet. We also show different fragmentation scenarios recorded with high-speed video, one of them being a jelly fish like liquid film that eventually fragments into smaller drops.

  12. A PIV Study of Drop-interface Coalescence with Surfactants

    Science.gov (United States)

    Weheliye, Weheliye Hashi; Dong, Teng; Angeli, Panagiota

    2017-11-01

    In this work, the coalescence of a drop with an aqueous-organic interface was studied by Particle Image Velocimetry (PIV). The effect of surfactants on the drop surface evolution, the vorticity field and the kinetic energy distribution in the drop during coalescence were investigated. The coalescence took place in an acrylic rectangular box with 79% glycerol solution at the bottom and Exxsol D80 oil above. The glycerol solution drop was generated through a nozzle fixed at 2cm above the aqueous/oil interface and was seeded with Rhodamine particles. The whole process was captured by a high-speed camera. Different mass ratios of non-ionic surfactant Span80 to oil were studied. The increase of surfactant concentration promoted deformation of the interface before the rupture of the trapped oil film. At the early stages after film rupture, two counter-rotating vortices appeared at the bottom of the drop which then travelled to the upper part. The propagation rates, as well as the intensities of the vortices decreased at high surfactant concentrations. At early stages, the kinetic energy was mainly distributed near the bottom part of the droplet, while at later stages it was distributed near the upper part of the droplet. Programme Grant MEMPHIS, Chinese Scholarship Council (CSC).

  13. Experimental study of drop impacts on soap films

    Science.gov (United States)

    Yawar, Ali; Basu, Saikat; Concha, Andres; Bandi, Mahesh

    2015-11-01

    Impinging drops on flowing and static soap films demonstrate at least three distinct types of impact regimes: (a) the drop bounces off the film surface, (b) it coalesces with the downstream flow for a moving film and for static films it gets assimilated within the film, and (c) it pierces through the film. The interaction presents a unique opportunity to explore the impact of a quasi one-dimensional object on a two-dimensional fluid, much like a comet impacting on a thin atmosphere. We present a detailed experimental study of droplet impacts on soap film flow, for a number of film inclination angles and falling heights of the drop. Imaging techniques employed include sodium lamp interferometry to measure film thickness fluctuations and particle tracking velocimetry to measure the velocity field. Film thickness measures approximately 10 microns and the drop diameter is 1 mm. We mostly observe the bouncing-off regime for smaller inclination angles. However, at higher impact angles, puncturing of the film becomes a more common occurrence. We show that when the drop bounces off the film, there is a momentum transfer leading to vortex dipole shedding, along with the generation of capillary waves; an impulsive regime that may share correspondence with the locomotion of water striders.

  14. A Novel Virus Causes Scale Drop Disease in Lates calcarifer.

    Science.gov (United States)

    de Groof, Ad; Guelen, Lars; Deijs, Martin; van der Wal, Yorick; Miyata, Masato; Ng, Kah Sing; van Grinsven, Lotte; Simmelink, Bartjan; Biermann, Yvonne; Grisez, Luc; van Lent, Jan; de Ronde, Anthony; Chang, Siow Foong; Schrier, Carla; van der Hoek, Lia

    2015-08-01

    From 1992 onwards, outbreaks of a previously unknown illness have been reported in Asian seabass (Lates calcarifer) kept in maricultures in Southeast Asia. The most striking symptom of this emerging disease is the loss of scales. It was referred to as scale drop syndrome, but the etiology remained enigmatic. By using a next-generation virus discovery technique, VIDISCA-454, sequences of an unknown virus were detected in serum of diseased fish. The near complete genome sequence of the virus was determined, which shows a unique genome organization, and low levels of identity to known members of the Iridoviridae. Based on homology of a series of putatively encoded proteins, the virus is a novel member of the Megalocytivirus genus of the Iridoviridae family. The virus was isolated and propagated in cell culture, where it caused a cytopathogenic effect in infected Asian seabass kidney and brain cells. Electron microscopy revealed icosahedral virions of about 140 nm, characteristic for the Iridoviridae. In vitro cultured virus induced scale drop syndrome in Asian seabass in vivo and the virus could be reisolated from these infected fish. These findings show that the virus is the causative agent for the scale drop syndrome, as each of Koch's postulates is fulfilled. We have named the virus Scale Drop Disease Virus. Vaccines prepared from BEI- and formalin inactivated virus, as well as from E. coli produced major capsid protein provide efficacious protection against scale drop disease.

  15. Handling Test of Eye Drop Dispenser—Comparison of Unit-Dose Pipettes with Conventional Eye Drop Bottles

    Science.gov (United States)

    Latvala, Terho; Ropo, Auli

    2010-01-01

    Abstract Purpose The aims of this study were to investigate how elderly people handle single-use eye drop dispensers (unit-dose pipettes) and to compare the performance with conventional eye drop bottles. Methods In this open-label study, the handling of unit-dose pipettes and conventional eye drop bottles was compared in 41 elderly people who had little or no prior regular use of eye drop dispensers. The participants tested both types of dispenser once, and the following 7 variables were studied: ease/difficulty of opening the dispenser; influence of the size for handling of the dispenser; influence of the shape for handling of the dispenser; observation of the contents in the dispenser; the feeling of the dispenser in the hand; ease/difficulty of drop instillation on the eye from the dispenser; and overall performance of the eye drop dispenser. The dispensers contained isotonic saline, and a visual analog scale was used for assessment of each of the above variables. Results The mean age of the participants was 73 years. A statistically significant difference in favor of the unit-dose pipettes was found with respect to observation of the contents in the dispenser, ease of administration, and the overall performance. Women regarded the unit-dose pipettes generally better than the bottles, but such a difference was not seen in men. Conclusions The study participants managed the unit-dose pipettes at least as well as the conventional eye drop bottles. If anything, the unit-dose pipettes appeared to be easier to use. PMID:20565314

  16. Iterative reconstruction of transcriptional regulatory networks: an algorithmic approach.

    Directory of Open Access Journals (Sweden)

    Christian L Barrett

    2006-05-01

    Full Text Available The number of complete, publicly available genome sequences is now greater than 200, and this number is expected to rapidly grow in the near future as metagenomic and environmental sequencing efforts escalate and the cost of sequencing drops. In order to make use of this data for understanding particular organisms and for discerning general principles about how organisms function, it will be necessary to reconstruct their various biochemical reaction networks. Principal among these will be transcriptional regulatory networks. Given the physical and logical complexity of these networks, the various sources of (often noisy data that can be utilized for their elucidation, the monetary costs involved, and the huge number of potential experiments approximately 10(12 that can be performed, experiment design algorithms will be necessary for synthesizing the various computational and experimental data to maximize the efficiency of regulatory network reconstruction. This paper presents an algorithm for experimental design to systematically and efficiently reconstruct transcriptional regulatory networks. It is meant to be applied iteratively in conjunction with an experimental laboratory component. The algorithm is presented here in the context of reconstructing transcriptional regulation for metabolism in Escherichia coli, and, through a retrospective analysis with previously performed experiments, we show that the produced experiment designs conform to how a human would design experiments. The algorithm is able to utilize probability estimates based on a wide range of computational and experimental sources to suggest experiments with the highest potential of discovering the greatest amount of new regulatory knowledge.

  17. Comparisons of knee and ankle joint angles and ground reaction force according to functional differences during single-leg drop landing.

    Science.gov (United States)

    Kim, Kewwan; Jeon, Kyoungkyu

    2016-04-01

    [Purpose] The purpose of this study was to determine potential predictors of functional instability of the knee and ankle joints during single-leg drop landing based on the prior history of injury. [Subjects and Methods] The subjects were 24 collegiate soccer players without pain or dysfunction. To compare the differences between the stable and unstable sides during single-leg drop landing, 8 motion analysis cameras and a force plate were used. The Cortex 4 software was used for a biomechanical analysis of 3 events. An independent t-test was used for statistical comparison between both sides; pangle of the knee joint can help prevent injury during landing.

  18. Meeting Regulatory Needs.

    Science.gov (United States)

    Weber, Michael Fred

    2017-02-01

    The world is experiencing change at an unprecedented pace, as reflected in social, cultural, economic, political, and technological advances around the globe. Regulatory agencies, like the U.S. Nuclear Regulatory Commission (NRC), must also transform in response to and in preparation for these changes. In 2014, the NRC staff commenced Project Aim 2020 to transform the agency by enhancing efficiency, agility, and responsiveness, while accomplishing NRC's safety and security mission. Following Commission review and approval in 2015, the NRC began implementing the approved strategies, including strategic workforce planning to provide confidence that NRC will have employees with the right skills and talents at the right time to accomplish the agency's mission. Based on the work conducted so far, ensuring an adequate pipeline of radiation protection professionals is a significant need that NRC shares with states and other government agencies, private industry, academia, as well as international counterparts. NRC is working to ensure that sufficient radiation protection professionals will be available to fulfill its safety and security mission and leverage the work of the National Council on Radiation Protection and Measurements, the Conference of Radiation Control Program Directors, the Health Physics Society, the Organization of Agreement States, the International Atomic Energy Agency, the Nuclear Energy Agency, and others.

  19. Criteria for drop generation in multiphase microfluidic devices.

    Science.gov (United States)

    Buttacci, Joseph D; Loewenberg, Michael; Roberts, Christine C; Nemer, Martin B; Rao, Rekha R

    2017-06-01

    A theory is presented for the transition between the coflowing and the drop-generation regimes observed in microfluidic channels with a rectangular cross section. This transition is characterized by a critical ratio of the dispersed- to continuous-phase volume flow rates. At flow-rate ratios higher than this critical value, drop generation is suppressed. The critical ratio corresponds to the fluid cross section where the dispersed-phase fluid is just tangent to the channel walls. The transition criterion is a function of the ratio of the fluid viscosities, the three-phase contact angle formed between the fluid phases and the channel walls, and the aspect ratio of the channel cross section; the transition is independent of interfacial tension. Hysteretic behavior of drop generation with respect to the flow-rate ratio is predicted for partially wetting dispersed-phase fluids. Experimental data are consistent with this theory.

  20. Viscosity Measurement via Drop Coalescence: A Space Station Experiment

    Science.gov (United States)

    Antar, Basil; Ethridge, Edwin C.

    2010-01-01

    The concept of using low gravity experimental data together with CFD simulations for measuring the viscosity of highly viscous liquids was recently validated on onboard the International Space Station (ISS). A series of microgravity tests were conducted for this purpose on the ISS in July, 2004 and in May of 2005. In these experiments two liquid drops were brought manually together until they touched and were allowed to coalesce under the action of the capillary force alone. The coalescence process was recorded photographically from which the contact radius speed of the merging drops was measured. The liquid viscosity was determined by fitting the measured data with accurate numerical simulation of the coalescence process. Several liquids were tested and for each liquid several drop diameters were employed. Experimental and numerical results will be presented in which the viscosity of several highly viscous liquids were determined using this technique.

  1. Green chemistry and nanofabrication in a levitated Leidenfrost drop

    Science.gov (United States)

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-10-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal-polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials.

  2. Investigating Call Drops with Field Measurements on Commercial Mobile Phones

    DEFF Research Database (Denmark)

    Messina, Alessandro; Caragea, Gabriel; Compta, Pol Torres

    2013-01-01

    One of the biggest problems nowadays for network operators are occurring call drops. This problem has been increasing in the last years specially since the advent of 3G. The investigation in the operator's network is very time intensive and due to the highly priced hardware only a few measurements...... can be done per day. In this paper we present a new methodology to investigate call drops by using mobile phones to do the measurements following the concept of citizen sensing. Therefore, a mobile application for Android is made that collects all necessary data and dumps the measurement results...... in a centralized database where the measurements are evaluated and represented on Google Maps. With a post analysis of the measurements, a classification of the call drops results is made. The collected data is also used to show some statistics related to the battery level and the received signal strength between...

  3. Estimation of pressure drop in gasket plate heat exchangers

    Directory of Open Access Journals (Sweden)

    Neagu Anisoara Arleziana

    2016-06-01

    Full Text Available In this paper, we present comparatively different methods of pressure drop calculation in the gasket plate heat exchangers (PHEs, using correlations recommended in literature on industrial data collected from a vegetable oil refinery. The goal of this study was to compare the results obtained with these correlations, in order to choose one or two for practical purpose of pumping power calculations. We concluded that pressure drop values calculated with Mulley relationship and Buonopane & Troupe correlation were close and also Bond’s equation gave results pretty close to these but the pressure drop is slightly underestimated. Kumar correlation gave results far from all the others and its application will lead to oversize. In conclusion, for further calculations we will chose either the Mulley relationship or the Buonopane & Troupe correlation.

  4. Hemolymph drop impact outcomes on surfaces with varying wettability

    Science.gov (United States)

    Milionis, Athanasios; Ghokulla Krishnan, K.; Loth, Eric

    2015-08-01

    Insect fouling from coagulated hemolymph and exoskeleton parts is a major challenge in the aerospace industry for the next generation of aerodynamic surfaces, which will employ laminar flow that requires extremely smooth surfaces. However, the wetting physics and dynamics of hemolymph (insect blood) on surfaces are not well understood. The present study seeks to gain a fundamental insight on the effect of surface wetting characteristics and dynamics resulting from a hemolymph drop impact, the first such study. In particular, hemolymph drops extracted from Acheta domesticus were dispensed from a range of heights to vary the kinetic impact on surfaces, which had widely varying water wetting behavior (from superhydrophilic to superhydrophobic). The impact dynamics were investigated with high-speed imaging while the dried residues were studied with optical microscopy. It was found that a superhydrophobic surface (based on thermoplastic with silica nano-particles) was able to significantly reduce hemolymph drop spreading, and even provide complete rebound when impacting on inclined surfaces.

  5. Regulatory Science in Professional Education.

    Science.gov (United States)

    Akiyama, Hiroshi

    2017-01-01

    In the field of pharmaceutical sciences, the subject of regulatory science (RS) includes pharmaceuticals, food, and living environments. For pharmaceuticals, considering the balance between efficacy and safety is a point required for public acceptance, and in that balance, more importance is given to efficacy in curing disease. For food, however, safety is the most important consideration for public acceptance because food should be essentially free of risk. To ensure food safety, first, any hazard that is an agent in food or condition of food with the potential to cause adverse health effects should be identified and characterized. Then the risk that it will affect public health is scientifically analyzed. This process is called risk assessment. Second, risk management should be conducted to reduce a risk that has the potential to affect public health found in a risk assessment. Furthermore, risk communication, which is the interactive exchange of information and opinions concerning risk and risk management among risk assessors, risk managers, consumers, and other interested parties, should be conducted. Food safety is ensured based on risk analysis consisting of the three components of risk assessment, risk management, and risk communication. RS in the field of food safety supports risk analysis, such as scientific research and development of test methods to evaluate food quality, efficacy, and safety. RS is also applied in the field of living environments because the safety of environmental chemical substances is ensured based on risk analysis, similar to that conducted for food.

  6. Regulatory elements in molecular networks.

    Science.gov (United States)

    Doane, Ashley S; Elemento, Olivier

    2017-05-01

    Regulatory elements determine the connectivity of molecular networks and mediate a variety of regulatory processes ranging from DNA looping to transcriptional, posttranscriptional, and posttranslational regulation. This review highlights our current understanding of the different types of regulatory elements found in molecular networks with a focus on DNA regulatory elements. We highlight technical advances and current challenges for the mapping of regulatory elements at the genome-wide scale, and describe new computational methods to uncover these elements via reconstructing regulatory networks from large genomic datasets. WIREs Syst Biol Med 2017, 9:e1374. doi: 10.1002/wsbm.1374 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

  7. Tear fluid-eye drops compatibility assessment using surface tension.

    Science.gov (United States)

    Hotujac Grgurević, Martina; Juretić, Marina; Hafner, Anita; Lovrić, Jasmina; Pepić, Ivan

    2017-02-01

    To evaluate the compatibility of commercially available eye drop surface tension with the tear film physiological range and to characterize commonly used ophthalmic excipients in terms of their surface activity under eye-biorelevant conditions. There are a number of quality requirements for the eye drops (e.g. tonicity, pH, viscosity, refractive index) that needs to comply with the physiological parameters of the eye surface. However, the adjustment of surface tension properties of the eye drops to the normal range of surface tension at the air/tear fluid interface (40-46 mN/m) has received rather less attention thus far. Yet, the surface tension at the air/tear fluid interface is of vital importance for the normal function of the eye surface. The surface tension compatibility of the isotonic aqueous solutions of commonly used ophthalmic excipients as well as 18 approved eye drops with the tear fluid have been evaluated using surface tension method. Each ophthalmic ingredient including the preservatives, solubilizing agents and thickening agents can influence the surface tension of the final formulation. In case of complex ophthalmic formulations one should also consider the possible interactions among excipients and consequent impact on overall surface activity. Out of 18 evaluated eye drops, three samples were within, 12 samples were below and three samples were above the physiological range of the tear fluid surface tension. Our results provide a rationale for clinical studies aiming to assess the correlation between the eye drops surface tension and the tear film (in)stability.

  8. Drop-out probabilities of IrisPlex SNP alleles

    DEFF Research Database (Denmark)

    Andersen, Jeppe Dyrberg; Tvedebrink, Torben; Mogensen, Helle Smidt

    2013-01-01

    In certain crime cases, information about a perpetrator's phenotype, including eye colour, may be a valuable tool if no DNA profile of any suspect or individual in the DNA database matches the DNA profile found at the crime scene. Often, the available DNA material is sparse and allelic drop......-out when the amount of DNA was greater than 125 pg for 29 cycles of PCR and greater than 62 pg for 30 cycles of PCR. With the use of a logistic regression model, we estimated the allele specific probability of drop-out in heterozygote systems based on the signal strength of the observed allele...

  9. Drop and Recovery of Sensor Nodes Using UAVs

    OpenAIRE

    Voldsund, Vegard

    2014-01-01

    The goal of this project is to make a system able of executing drop and recovery of sensor nodes at sea by the use of UAVs.The sensor node will be a lightweight packet that can contain different sensors depending on the mission. These sensor nodes will be dropped into the sea where they will float on the surface. Examples of use for the sensor nodes can be to log temperature, currents, salinity or water quality. Hence they can be very useful in for instance climate research or for detectingoi...

  10. Drops and bubbles in contact with solid surfaces

    CERN Document Server

    Ferrari, Michele

    2012-01-01

    The third volume in a series dedicated to colloids and interfaces, Drops and Bubbles in Contact with Solid Surfaces presents an up-to-date overview of the fundamentals and applications of drops and bubbles and their interaction with solid surfaces. The chapters cover the theoretical and experimental aspects of wetting and wettability, liquid-solid interfacial properties, and spreading dynamics on different surfaces, including a special section on polymers. The book examines issues related to interpretation of contact angle from nano to macro systems. Expert contributors discuss interesting pec

  11. Medium carbon vanadium micro alloyed steels for drop forging

    Energy Technology Data Exchange (ETDEWEB)

    Jeszensky, Gabor; Plaut, Ronald Lesley

    1992-12-31

    Growing competitiveness of alternative manufacturing routes requires cost minimization in the production of drop forged components. The authors analyse the potential of medium carbon, vanadium microalloyed steels for drop forging. Laboratory and industrial experiments have been carried out emphasizing deformation and temperature cycles, strain rates and dwell times showing a typical processing path, associated mechanical properties and corresponding microstructures. The steels the required levels of mechanical properties on cooling after forging, eliminating subsequent heat treatment. The machinability of V-microalloyed steels is also improved when compared with plain medium carbon steels. (author) 17 refs., 19 figs., 5 tabs.

  12. Zero-Gravity Research Facility Drop Test (2/4)

    Science.gov (United States)

    1995-01-01

    An experiment vehicle plunges into the deceleration pit at the end of a 5.18-second drop in the Zero-Gravity Research Facility at NASA's Glenn Research Center. The Zero-Gravity Research Facility was developed to support microgravity research and development programs that investigate various physical sciences, materials, fluid physcis, and combustion and processing systems. Payloads up to 1 meter in diameter and 455 kg in weight can be accommodated. The facility has a 145-meter evacuated shaft to ensure a disturbance-free drop. This is No. 2 of a sequence of 4 images. (Credit: NASA/Glenn Research Center)

  13. Zero-Gravity Research Facility Drop Test (3/4)

    Science.gov (United States)

    1995-01-01

    An experiment vehicle plunges into the deceleration at the end of a 5.18-second drop in the Zero-Gravity Research Facility at NASA's Glenn Research Center. The Zero-Gravity Research Facility was developed to support microgravity research and development programs that investigate various physical sciences, materials, fluid physics, and combustion and processing systems. Payloads up to one-meter in diameter and 455 kg in weight can be accommodated. The facility has a 145-meter evacuated shaft to ensure a disturbance-free drop. This is No. 3 of a sequence of 4 images. (Credit: NASA/Glenn Research Center)

  14. Zero-Gravity Research Facility Drop Test (1/4)

    Science.gov (United States)

    1995-01-01

    An experiment vehicle plunges into the deceleration pit at the end of a 5.18-second drop in the Zero-Gravity Research Facility at NASA's Glenn Research Center. The Zero-Gravity Research Facility was developed to support microgravity research and development programs that investigate various physical sciences, materials, fluid physics, and combustion and processing systems. Payloads up to 1 meter in diameter and 455 kg in weight can be accommodated. The facility has a 145-meter evacuated shaft to ensure a disturbance-free drop. This is No.1 of a sequence of 4 images. (Credit: NASA/Glenn Research Center)

  15. Zero-Gravity Research Facility Drop Test (4/4)

    Science.gov (United States)

    1995-01-01

    An experiment vehicle plunges into the deceleration pit at the end of a 5.18-second drop in the Zero-Gravity Research Facility at NASA's Glenn Research Center. The Zero-Gravity Research Facility was developed to support microgravity research and development programs that investigate various physical sciences, materials, fluid physics, and combustion and processing systems. Payloads up to one meter in diameter and 455 kg in weight can be accommodated. The facility has a 145-meter evacuated shaft to ensure a disturbance-free drop. This is No. 4 of a sequence of 4 images. (Credit: NASA/Glenn Research Center)

  16. Capacity for ethical and regulatory review of herbal trials in developing countries: a case study of Moringa oleifera research in HIV-infected patients

    OpenAIRE

    Monera-Penduka, Tsitsi G.; Maponga, Charles C.; Morse, Gene D.; Nhachi, Charles F. B.

    2017-01-01

    Background Lack of regulatory capacity limits the conduct of ethical and rigorous trials of herbal medicines in developing countries. Sharing ethical and regulatory experiences of successful herbal trials may accelerate the field while assuring human subjects protection. The methods and timelines for the ethical and regulatory review processes for the first drug regulatory authority approved herbal trial in Zimbabwe are described in this report. Methods The national drug regulatory authority ...

  17. Reversing the Approach to Null Subjects: A Perspective from Language Acquisition.

    Science.gov (United States)

    Duguine, Maia

    2017-01-01

    This paper proposes a new model for null subjects, and focuses on its implications for language development. The literature on pro-drop generally considers that not allowing null subjects is, informally speaking, the "default" option in natural languages, and appeals to particular morphosyntactic mechanisms in order to account for those languages in which the subject can be omitted. Shifting the perspective, the inverse approach postulates that pro-drop is (almost) a default grammatical setting, and that non-pro-drop results from the intervention of independent factors that block pro-drop in the derivation. The paper explores the consequences of the inverse approach in the domain of language acquisition, arguing that this model allows to account for a number of properties of child languages. It opens an avenue of research worth exploring, one that could give new solutions to old problems.

  18. Rapid determination of caffeine in one drop of beverages and foods using drop-to-drop solvent microextraction with gas chromatography/mass spectrometry.

    Science.gov (United States)

    Shrivas, Kamlesh; Wu, Hui-Fen

    2007-11-02

    A simple and rapid sample cleanup and preconcentration method for the quantitative determination of caffeine in one drop of beverages and foods by gas chromatography/mass spectrometry (GC/MS) has been proposed using drop-to-drop solvent microextraction (DDSME). The best optimum experimental conditions for DDSME were: chloroform as the extraction solvent, 5 min extraction time, 0.5 microL exposure volume of the extraction phase and no salt addition at room temperature. The optimized methodology exhibited good linearity between 0.05 and 5.0 microg/mL with correlation coefficient of 0.980. The relative standard deviation (RSD) and limits of detection (LOD) of the DDSME/GC/MS method were 4.4% and 4.0 ng/mL, respectively. Relative recovery of caffeine in beverages and foods were found to be 96.6-101%, which showing good reliability of this method. This DDSME excludes the major disadvantages of conventional method of caffeine extraction, like large amount of organic solvent and sample consumption and long sample pre-treatment process. So, this approach proves that the DDSME/GC/MS technique can be applied as a simple, fast and feasible diagnosis tool for environmental, food and biological application for extremely small amount of real sample analysis.

  19. Sensibility and Subjectivity: Levinas’ Traumatic Subject

    Directory of Open Access Journals (Sweden)

    Rashmika Pandya

    2011-02-01

    Full Text Available The importance of Levinas’ notions of sensibility and subjectivity are evident in the revision of phenomenological method by current phenomenologists such as Jean-Luc Marion and Michel Henry. The criticisms of key tenants of classical phenomenology, intentionality and reduction, are of a particular note. However, there are problems with Levinas’ characterization of subjectivity as essentially sensible. In “Totality and Infinity” and “Otherwise than Being”, Levinas criticizes and recasts a traditional notion of subjectivity, particularly the notion of the subject as the first and foremost rational subject. The subject in Levinas’ works is characterized more by its sensibility and affectedness than by its capacity to reason or affect its world. Levinas ties rationality to economy and suggests an alternative notion of reason that leads to his analysis of the ethical relation as the face-to-face encounter. The ‘origin’ of the social relation is located not in our capacity to know but rather in a sensibility that is diametrically opposed to the reason understood as economy. I argue that the opposition in Levinas’ thought between reason and sensibility is problematic and essentially leads to a self-conflicted subject. In fact, it would seem that violence characterizes the subject’s self-relation and, thus, is also inscribed at the base of the social relation. Rather than overcoming a problematic tendency to dualistic thought in philosophy Levinas merely reverses traditional hierarchies of reason/emotion, subject/object and self/other. 

  20. FUNCTIONAL AND NEUROMUSCULAR CHANGES IN THE HAMSTRINGS AFTER DROP JUMPS AND LEG CURLS

    Directory of Open Access Journals (Sweden)

    Nejc Sarabon

    2013-09-01

    Full Text Available The purpose of this study was to use a holistic approach to investigate changes in jumping performance, kinaesthesia, static balance, isometric strength and fast stepping on spot during a 5-day recovery period, following an acute bout of damaging exercise consisted of drop jumps and leg curls, where specific emphasis was given on the hamstring muscles. Eleven young healthy subjects completed a series of highly intensive damaging exercises for their hamstring muscles. Prior to the exercise, and during the 5-day recovery period, the subjects were tested for biochemical markers (creatine kinase, aspartate aminotransferase, and lactate dehydrogenase, perceived pain sensation, physical performance (squat jump, counter movement jump, maximal frequency leg stamping, maximal isometric torque production and maximally explosive isometric torque production, kinaesthesia (active torque tracking and static balance. We observed significant decreases in maximal isometric knee flexion torque production, the rate of torque production, and majority of the parameters for vertical jump performance. No alterations were found in kinaesthesia, static balance and fast stepping on spot. The highest drop in performance and increase in perceived pain sensation generally occurred 24 or 48 hours after the exercise. Damaging exercise substantially alters the neuromuscular functions of the hamstring muscles, which is specifically relevant for sports and rehabilitation experts, as the hamstrings are often stretched to significant lengths, in particular when the knee is extended and hip flexed. These findings are practically important for recovery after high-intensity trainings for hamstring muscles

  1. Reliability of knee biomechanics during a vertical drop jump in elite female athletes.

    Science.gov (United States)

    Mok, Kam-Ming; Petushek, Erich; Krosshaug, Tron

    2016-05-01

    The purpose of the study was to assess the within-session and between-session reliability of knee kinematics and kinetics in a vertical drop jump task among elite female handball and football athletes. Specifically, we aimed to quantify the within-session waveform consistency and between-session consistency of the subject ranking for a variety of knee kinematics and kinetics. Forty-one elite female handball and football (soccer) athletes were tested in two sessions. The reliability of three-dimensional knee biomechanical measurements was quantified by the intra-class correlation, Spearman's rank correlation, and typical error. All the selected discrete variables achieved excellent within-session reliability (ICC>0.87). The typical error of valgus angles, internal rotation angles, and internal rotation moment was constant throughout the whole stance phase. For between-session reliability, the selected discrete variables achieved good to excellent reliability (ICC>0.69), except peak internal rotation moment (ICC=0.40). All between-session rank correlation coefficients ranged from 0.56 to 0.90. Most of the discrete variables achieved good to excellent reliability in both within-session and between-session analysis. Moreover, moderate to strong between-session consistency of subject rankings was found, implying that the measurements assessed during the vertical drop jump demonstrate sufficient reliability to be used in both single-session and multiple-session studies. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Vestibular evoked myogenic potential (VEMP) in patients with Ménière's disease with drop attacks.

    Science.gov (United States)

    Timmer, Ferdinand C A; Zhou, Guangwei; Guinan, John J; Kujawa, Sharon G; Herrmann, Barbara S; Rauch, Steven D

    2006-05-01

    In this retrospective study, we tested the hypothesis that vestibular evoked myogenic potential (VEMP) thresholds are more often elevated or absent in patients with Ménière's disease experiencing Tumarkin drop attacks than in other patients with Ménière's disease. Subjects included normal subjects (n = 14) and patients with unilateral Ménière's disease by AAO-HNS (1995) diagnostic criteria with (n = 12) and without (n = 82) Tumarkin drop attacks at a large specialty hospital otology service. VEMP threshold testing was conducted using 250, 500, and 1,000 Hz tone burst stimuli. VEMP responses were present in at all frequencies in both ears of all normal subjects. In unaffected ears of patients with unilateral Ménière's disease, VEMPs were undetectable in 13% of measurements attempted. This number rose to 18% in affected ears of patients with unilateral Ménière's disease and to 41% in Meniere ears with Tumarkin drop attacks. Frequency tuning of the VEMP response in normal subjects showed lowest thresholds at 500 Hz. In Meniere ears, the tuning was altered such that the 500-Hz thresholds were higher than the 1,000-Hz thresholds. There was a gradient of threshold elevation and altered tuning that corresponded to the gradient of worsening disease. Our findings support the hypothesis that Tumarkin drop attacks arise from advanced disease involving the saccule and that VEMP may be a clinically valuable metric of disease severity or progression in patients with Ménière's disease.

  3. Influence of fall height on high impact polystyrene deformation and characteristics of drop weight test

    Directory of Open Access Journals (Sweden)

    Mizera Ales

    2017-01-01

    Full Text Available This study deals with high impact polystyrene (HIPS which was subjected the drop-weight test. HIPS is a polymer produced by the reaction between butadiene synthetic elastomer and styrene (5–14 % which contains the crystal polymer in certain amounts and is commonly used in mechanical engineering applications where machine parts are exposed to impact loading. The injection moulded HIPS samples were subjected the penetration test at different fall heights and the results were subsequently evaluated and discussed. It was found out that all fall heights are suitable for HIPS penetration, but the optimal one is 50 J because of the smallest variation range. Higher heights are not needed because of increasing power consumption of the test device. From the results, it is clear, that HIPS is not so highly impact resistant material as for example HDPE, because of that is this material suitable for applications where is not often exposed to too big impacts at high velocities.

  4. Many Drops Interactions II: Simulation of Coalescence, Flocculation and Fragmentation of Multiple Colliding Drops with Smoothed Particle Hydrodynamics

    Directory of Open Access Journals (Sweden)

    Alejandro Acevedo-Malavé

    2012-06-01

    Full Text Available In this study, the SPH method is applied to simulate for the first time the multiple hydrodynamics collisions and the formation of clusters of equally sized liquid drops in three-dimensional space. Smoothed Particle Hydrodynamics is a Lagrangian mesh-free formalism and has been useful to model continuous fluid. This formalism is employed to solve the Navier-Stokes equations by replacing the fluid with a set of particles. These particles are interpolation points from which properties of the fluid can be determined. We observe that when the velocity of collision varies between 0.2 mm/ms and 30.0 mm/ms different results may arise, such as: coalescence, fragmentation and formation of clusters of liquid drops. The velocity vector fields formed inside the drops during the collision process are shown.

  5. 78 FR 62417 - Regulatory Capital Rules: Regulatory Capital, Implementation of Basel III, Capital Adequacy...

    Science.gov (United States)

    2013-10-22

    ... Part 324 RIN 3064-AD95 Regulatory Capital Rules: Regulatory Capital, Implementation of Basel III... Capital Rules: Regulatory Capital, Implementation of Basel III, Capital Adequacy, Transition Provisions...

  6. Effect of recombinant human epidermal growth factor eye drops and deproteinized calf blood extract eye drops on corneal edema after phacoemulsification

    National Research Council Canada - National Science Library

    Jia Wang

    2017-01-01

    AIM:To compare the effect of recombinant human epidermal growth factor eye drops and deproteinized calf blood extract eye drops on corneal edema after phacoemulsification. METHODS:Totally 72 cases(72 eyes...

  7. Investigation of drop geometry at free-falling process depending on volume of dozing

    Directory of Open Access Journals (Sweden)

    Batischeva Ksenia A.

    2015-01-01

    Full Text Available Present work performs experimental investigation of the changes in the geometric shape of the drop in terms of its free-falling, depending on the conditions of drop formation on dispenser. It was found that volume and velocity of drop formation on dispenser are the factors affecting the geometric shape of the drop in terms of its free-falling.

  8. The Comparing the Leg Muscles Electromyography during Single Leg Drop Landing in Pesplanus and Normal Men

    Directory of Open Access Journals (Sweden)

    mostafa bazvand

    2016-03-01

    Full Text Available Objective: pesplanus is one of the changes that brings about changes in muscle activation patterns. Being aware of muscles activity changes in various standing positions among pesplanus patients provides insights into preventing lower extremity injuries in this population. The aim of this study was to compare leg muscles electromyography during various standing positions in pesplanus and normal subjects. Methods: 60 healthy male university students, 30 subjects with pesplanus deformity (with average age 23/54±3/57 year, average height 175/34±7/62 cm, average weight 74/87±10/72 kg and 30 normal subjects (with average age 22/97±2/38 year, average height 176/6±5/59 cm, average weight 73/58±8/36 kg participated in this comparative study. Deformity of pesplanus was assessed with navicular drop test. Each subject performed single-leg landing dropping from 30cm height onto a force platform where muscles activity was recorded with EMG device. For data analysis, Matlab and Spss softwares were used and independent sample t-test was used to compare the dependent variables at a significance level of P &le 0/05. Results: Significant differences were observed between the two groups for the activities of the longus peroneus and anterior tibialis muscles ( p&le0/05 while no significant differences were observed in other muscles. Conclusion: The changes in the normal structure of the foot might affect muscle activities during standing, which can cause changes in the injury patterns. Therefore, it is proposed that focusing on corrective exercises and therapy plan can reduce these risks.

  9. Regulatory mark; Marco regulatorio

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-10-15

    This chapter is based on a work performed in distinct phases. The first phase consisted in of the analysis regulatory legislation existent in Brazil for the sugar-alcohol sector since the beginning of the X X century. This analysis allowed the identification of non existent points and legal devices related to the studied aspects, and that were considered as problematic for the sector expansion. In the second phase, related treaties and international agreements was studied and possible obstacles for the brazilian bio ethanol exportation for the international market. Initiatives were examined at European Union, United States of America, Caribbean and countries of the sub-Saharan Africa. In this phase, policies were identified related to the incentives and adoption of use of bio fuels added to the gasoline in countries or group of countries considered as key for the consolidation of bio ethanol as a world commodity.

  10. Comparative evaluation of Nano-Hydroxyapatite preparation and Calcium Sucrose Phosphate on microhardness of deciduous teeth after iron drop exposure - An in-vitro study

    Science.gov (United States)

    Baid, Rutika; Baliga, Sudhindra; Thosar, Nilima

    2017-01-01

    Background To evaluate and compare the microhardness of deciduous teeth treated with nano-hydroxyapatite and calcium sucrose phosphate after iron drop exposure. Material and Methods Twenty healthy anterior deciduous teeth were collected and stored in 0.9% saline solution at room temperature. All the teeth were immersed in artificial saliva in an incubator shaker at 37° for an hour and then subjected to Vickers microhardness test at 100g load for 5 seconds. The teeth were then immersed in iron drop for 5 minutes, twice daily, rinsed with distilled water and kept in artificial saliva. This procedure was repeated for 7 days and teeth were subjected to microhardness testing. Further, the teeth were divided in two groups, each group containing 10 teeth. In group I, nanohydroxyapatite preparation and in group II, calcium sucrose phosphate were applied for 10 minutes, twice daily for 7 days and subjected again to microhardness testing again. Results Vickers microhardness analysis revealed that iron drop exposure to teeth caused significant decrease in microhardness (pmicrohardness (206.90) than that after iron drop exposure. Similarly, application of calcium sucrose phosphate in Group II showed significantly increased enamel microhardness (200.89) than that after iron drop exposure. Statistical difference was seen between the two groups, with nanohydroxyapatite preparation showing increased microhardness than calcium sucrose phosphate. Conclusions Nanohydroxyapatite preparation and calcium sucrose phosphate have remineralizing effect over teeth affected by acid challenge of iron drops, nanohydroxyapatite preparation showing better results than calcium sucrose phosphate. Key words:Iron drops, Nanohydroxyapaptite, calcium sucrose phosphate, anticay. PMID:28469827

  11. Regulatory considerations for biosimilars

    Directory of Open Access Journals (Sweden)

    Ranjani Nellore

    2010-01-01

    Full Text Available Currently there is considerable interest in the legislative debate around generic biological drugs or "biosimilars" in the EU and US due to the large, lucrative market that it offers to the industry. While some countries have issued a few regulatory guidelines as well as product specific requirements, there is no general consensus as to a single, simple mechanism similar to the bioequivalence determination that leads to approval of generic small molecules all over the world. The inherent complex nature of the molecules, along with complicated manufacturing and analytical techniques to characterize them make it difficult to rely on a single human pharmacokinetic study for assurance of safety and efficacy. In general, the concept of comparability has been used for evaluation of the currently approved "similar" biological where a step by step assessment on the quality, preclinical and clinical aspects is made. In India, the focus is primarily on the availability and affordability of life-saving drugs. In this context every product needs to be evaluated on its own merit irrespective of the innovator brand. The formation of the National Biotechnology Regulatory Authority may provide a step in the right direction for regulation of these complex molecules. However, in order to have an efficient machinery for initial approval and ongoing oversight with a country-specific focus, cooperation with international authorities for granting approvals and continuous risk-benefit review is essential. Several steps are still needed for India to be perceived as a country that leads the world in providing quality biological products.

  12. Drop-in Security for Distributed and Portable Computing Elements.

    Science.gov (United States)

    Prevelakis, Vassilis; Keromytis, Angelos

    2003-01-01

    Proposes the use of a special purpose drop-in firewall/VPN gateway called Sieve, that can be inserted between the mobile workstation and the network to provide individualized security services for that particular station. Discusses features and advantages of the system and demonstrates how Sieve was used in various application areas such as at…

  13. Electrowetting: a versatile tool for drop manipulation, generation, and characterization.

    Science.gov (United States)

    Mugele, Frieder; Duits, Michel; van den Ende, Dirk

    2010-12-15

    Electrowetting is arguably the most flexible tool to control and vary the wettability of solid surfaces by an external control parameter. In this article we briefly discuss the physical origin of the electrowetting effect and subsequently present a number of approaches for selected novel applications. Specifically, we will discuss the use of EW as a tool to extract materials properties such as interfacial tensions and elastic properties of drops. We will describe some modifications of the EW equation that apply at finite AC voltage for low conductivity fluids when the electric field can partially penetrate into the drops. We will discuss two examples where finite conductivity effects have important consequences, namely electrowetting of topographically structured surfaces as well as the generation of drops in AC electric fields. Finally, we review recent attempts to incorporate electrowetting into conventional channel-based microfluidic devices in order to enhance the flexibility of controlling the generation of drops. Copyright © 2009 Elsevier B.V. All rights reserved.

  14. Analysis of Drop Call Probability in Well Established Cellular ...

    African Journals Online (AJOL)

    Technology in Africa has increased over the past decade. The increase in modern cellular networks requires stringent quality of service (QoS). Drop call probability is one of the most important indices of QoS evaluation in a large scale well-established cellular network. In this work we started from an accurate statistical ...

  15. Clinical utility of voriconazole eye drops in ophthalmic fungal keratitis

    Science.gov (United States)

    Al-Badriyeh, Daoud; Neoh, Chin Fen; Stewart, Kay; Kong, David CM

    2010-01-01

    Fungal keratitis is one of the major causes of ophthalmic mycosis and is difficult to treat. The range of common antifungal agents available for fungal keratitis remains inadequate and is generally associated with poor clinical outcomes. Voriconazole is a new generation triazole antifungal agent. Only marketed in systemic formulation and, with broad-spectrum activity and high intraocular penetration, voriconazole has demonstrated effectiveness against fungal keratitis. Systemic voriconazole, however, is not without side effects and is costly. Voriconazole eye drops have been prepared extemporaneously and used for the treatment of ophthalmic fungal keratitis. The current article sought to review the literature for evidence related to the effectiveness and safety of topical voriconazole and its corneal penetration into the aqueous humor of the eye. The voriconazole eye drops used are typically of 1% concentration, well tolerated by the eye, and are stable. Despite existing evidence to suggest that the eye drops are effective in the treatment of fungal keratitis, more studies are needed, especially in relation to using the eye drops as first-line and stand-alone treatment, preparation of higher concentrations, and optimal dosing frequency. PMID:20463910

  16. Measurement of surface and interfacial tension using pendant drop tensiometry.

    Science.gov (United States)

    Berry, Joseph D; Neeson, Michael J; Dagastine, Raymond R; Chan, Derek Y C; Tabor, Rico F

    2015-09-15

    Pendant drop tensiometry offers a simple and elegant solution to determining surface and interfacial tension - a central parameter in many colloidal systems including emulsions, foams and wetting phenomena. The technique involves the acquisition of a silhouette of an axisymmetric fluid droplet, and iterative fitting of the Young-Laplace equation that balances gravitational deformation of the drop with the restorative interfacial tension. Since the advent of high-quality digital cameras and desktop computers, this process has been automated with high speed and precision. However, despite its beguiling simplicity, there are complications and limitations that accompany pendant drop tensiometry connected with both Bond number (the balance between interfacial tension and gravitational forces) and drop volume. Here, we discuss the process involved with going from a captured experimental image to a fitted interfacial tension value, highlighting pertinent features and limitations along the way. We introduce a new parameter, the Worthington number, Wo, to characterise the measurement precision. A fully functional, open-source acquisition and fitting software is provided to enable the reader to test and develop the technique further. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  17. Drop morphologies on flexible fibers: influence of elastocapillary effects.

    Science.gov (United States)

    Sauret, Alban; Boulogne, François; Somszor, Katarzyna; Dressaire, Emilie; Stone, Howard A

    2016-12-21

    Various materials are made of long thin fibers that are randomly oriented to form a complex network in which drops of wetting liquid tend to accumulate at the nodes. The capillary force exerted by the liquid can bend flexible fibers, which in turn influences the morphology adopted by the liquid. In this paper, we investigate through a model situation the role of the fiber flexibility on the shape of a small volume of liquid on a pair of crossed flexible fibers. We characterize the liquid morphologies as we vary the volume of liquid, the angle between the fibers, and the length of the fibers. The drop morphologies previously reported for rigid crossed fibers, i.e., a drop, a column and a mixed morphology, are also observed on flexible crossed fibers with modified domains of existence. In addition, at small tilt angles between the fibers, a new behavior is observed: the fibers bend and collapse. Depending on the volume of liquid, a thin column with or without a drop is reported on the collapsed fibers. Our study suggests that the fiber flexibility adds a rich variety of behaviors that may be important for some applications.

  18. Using Single Drop Microextraction for Headspace Analysis with Gas Chromatography

    Science.gov (United States)

    Riccio, Daniel; Wood, Derrick C.; Miller, James M.

    2008-01-01

    Headspace (HS) gas chromatography (GC) is commonly used to analyze samples that contain non-volatiles. In 1996, a new sampling technique called single drop microextraction, SDME, was introduced, and in 2001 it was applied to HS analysis. It is a simple technique that uses equipment normally found in the undergraduate laboratory, making it ideal…

  19. Structure Irregularity Impedes Drop Roll-Off at Superhydrophobic Surfaces

    DEFF Research Database (Denmark)

    Larsen, Simon Tylsgaard; Andersen, Nis Korsgaard; Søgaard, Emil

    2014-01-01

    -off angles is found to be caused by a decrease of the receding contact angle, which in turn is caused by an increase of the triple phase contact line of the drops for those more irregular surfaces. To understand the observation, we propose to treat the microdrops as rigid bodies and apply a torque balance...

  20. Physiological and biochemical changes during banana ripening and finger drop

    NARCIS (Netherlands)

    Imsabai, W.; Ketsa, S.; Doorn, van W.G.

    2006-01-01

    Fruit drop of banana is due to breaking at the junction of the pedicel and pulp, and we found no true abscission zone. The breakage seems therefore due to weakening of the peel. We investigated pectin hydrolysis and some properties at the rupture zone, using `Hom Thong` (Musa acuminata, AAA Group)

  1. Effects of relative humidity on banana fruit drop

    NARCIS (Netherlands)

    Saengpook, C.; Ketsa, S.; Doorn, van W.G.

    2007-01-01

    Commercial ripening of banana fruit occurs at high relative humidity (RH), which prevents browning of damaged skin areas. In experiments with ripening at high RH (94 ± 1%) the individual fruit (fingers) of `Sucrier¿ (Musa acuminata, AA Group) banana exhibited a high rate of drop. The falling off of

  2. Reducing cyclone pressure drop with evasés

    Science.gov (United States)

    Cyclones are widely used to separate particles from gas flows and as air emissions control devices. Their cost of operation is proportional to the fan energy required to overcome their pressure drop. Evasés or exit diffusers potentially could reduce exit pressure losses without affecting collection...

  3. Allelic drop-out probabilities estimated by logistic regression

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Eriksen, Poul Svante; Asplund, Maria

    2012-01-01

    We discuss the model for estimating drop-out probabilities presented by Tvedebrink et al. [7] and the concerns, that have been raised. The criticism of the model has demonstrated that the model is not perfect. However, the model is very useful for advanced forensic genetic work, where allelic dro...

  4. Drop amalgam voltammetric study of lead complexation by natural ...

    African Journals Online (AJOL)

    A study of inorganic complexation of lead using drop amalgam voltammetry is described. The study has been carried out in simulated salt lake water and at ionic strength of 7.35 M, the predetermined ionic strength of Lake Katwe. The complexation of lead with the simple ligands (Cl-, CO32-) created anodic waves and the ...

  5. Personality disorders and treatment drop out in the homeless

    National Research Council Canada - National Science Library

    Salavera, Carlos; Tricás, José M; Lucha, Orosia

    2013-01-01

    ... the situation, and their inertia, determines treatment abandonment, with higher levels than in other populations. (8-10) Studies on withdrawal from treatment in people under addiction treatment have been done (11-16) and these have analyzed the comorbidity between dropping out and personality disorders. (17) The reviewed literature concludes t...

  6. Capillarity and wetting phenomena drops, bubbles, pearls, waves

    CERN Document Server

    Gennes, Pierre-Gilles; Quéré, David

    2004-01-01

    As I glance out my window in the early morning, I can see beads of droplets gracing a spider web. The film of dew that has settled on the threads is unstable and breaks up spontaneously into droplets. This phenomenon has implications for the treatment of textile fibers (the process known as "oiling"), glass, and carbon. It is no less important when applying mascara! I take my morning shower. The moment I step out, I dry off by way of evaporation (which makes me feel cold) and by dewetting (the process by which dry areas form spontaneously and expand on my skin). As I rush into my car under a pelting rain, my attention is caught by small drops stuck on my windshield. I also notice larger drops rolling down and others larger still that, like snails, leave behind them a trail of water. I ask myself what the difference is between these rolling drops and grains of sand tumbling down an incline. I wonder why the smallest drops remain stuck. The answers to such questions do help car manufacturers treat the surface o...

  7. Leidenfrost drops cooling surfaces: theory and interferometric measurement

    NARCIS (Netherlands)

    Van Limbeek, Michiel A. J.; Klein Schaarsberg, Martin H.; Sobac, Benjamin; Rednikov, Alexey; Sun, Chao; Colinet, Pierre; Lohse, Detlef

    2017-01-01

    When a liquid drop is placed on a highly superheated surface, it can be levitated by its own vapour. This remarkable phenomenon is referred to as the Leidenfrost effect. The thermally insulating vapour film results in a severe reduction of the heat transfer rate compared to experiments at lower

  8. La Gotita de Agua (The Little Drop of Water).

    Science.gov (United States)

    Palandra, Maria; Puigdollers, Carmen

    This Spanish reader for children in kindergarten and first grade is about a drop of water that comes to life in a trip through the water cycle of evaporation, condensation, and subsequent return to a drier part of the earth's surface environment. The story is suitable for reading aloud or independent reading. The text is entirely in Spanish.…

  9. Playing with Water Drops: From Wetting to Optics through Electrostatics

    Science.gov (United States)

    Domps, A.; Roques-Carmes, T.

    2011-01-01

    We present a consistent series of activities, including experiments and basic computational studies, investigating the shape and optical properties of water drops in connection with novel technological devices. Most of the work can be carried out with simple teaching equipment and is well suited to undergraduate students. Firstly, we show how the…

  10. Mathematics Anxiety and the Affective Drop in Performance

    Science.gov (United States)

    Ashcraft, Mark H.; Moore, Alex M.

    2009-01-01

    The authors provide a brief review of the history and assessment of math anxiety, its relationship to personal and educational consequences, and its important impact on measures of performance. Overall, math anxiety causes an "affective drop," a decline in performance when math is performed under timed, high-stakes conditions, both in laboratory…

  11. Water drop impact onto oil covered solid surfaces

    Science.gov (United States)

    Chen, Ningli; Chen, Huanchen; Amirfazli, Alidad

    2016-11-01

    Droplet impact onto an oily surface can be encountered routinely in industrial applications; e.g., in spray cooling. It is not clear from literature what impact an oil film may have on the impact process. In this work, water drop impact onto both hydrophobic (glass) and hydrophilic (OTS) substrates which were covered by oil films (silicone) of different thickness (5um-50um) and viscosity (5cst-100cst) were performed. The effects of drop impact velocity, film thickness, and viscosity of the oil film and wettability of the substrate were studied. Our results show that when the film viscosity and impact velocity is low, the water drop deformed into the usual disk shape after impact, and rebounded from the surface. Such rebound phenomena disappears, when the viscosity of oil becomes very large. With the increase of the impact velocity, crown and splashing appears in the spreading phase. The crown and splashing behavior appears more easily with the increase of film thickness and decrease of its viscosity. It was also found that the substrate wettability can only affect the impact process in cases which drop has a large Webber number (We = 594), and the film's viscosity and thickness are small. This work was support by National Natural Science Foundation of China and the Project Number is 51506084.

  12. The evaporation of the charged and uncharged water drops ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    assumed to be the temperature of adiabatic satura- tion. Their analysis also suffered from inaccuracies in determining the values of water vapour diffu- sivity and terminal ..... its evaporation. This heat-mass transfer process causes a temperature difference between the drop and its environment. The time required for a venti-.

  13. School drop out in Bangladesh: Insights using panel data

    Science.gov (United States)

    Sabates, R.; Hossain, A.; Lewin, K.M.

    2013-01-01

    This paper examines the relative strength of different factors associated with school drop out using data collected between 2007 and 2009 in Bangladesh. A sample of 9046 children, aged 4-15, was selected across six districts for a household survey focusing on children's school access and experiences. Two groups of children were identified: those…

  14. Drop Impact upon Micro- and Nanostructured Superhydrophobic Surfaces

    NARCIS (Netherlands)

    Tsai, Peichun Amy; Pacheco Benito, Sergio; Pirat, C.; Lefferts, Leonardus; Lohse, Detlef

    2009-01-01

    We experimentally investigate drop impact dynamics onto different superhydrophobic surfaces, consisting of regular polymeric micropatterns and rough carbon nanofibers, with similar static contact angles. The main control parameters are the Weber number We and the roughness of the surface. At small

  15. The evaporation of the charged and uncharged water drops ...

    Indian Academy of Sciences (India)

    A laboratory experiment has been performed to study the effect of ventilation on the rate of evaporation of the millimeter sized charged and uncharged water drops suspended in a vertical wind tunnel. The linear relationship, = 0.907 + 0.282 , observed between the mean ventilation coefficient, , and a ...

  16. Hydrocarbon Degradation In Poultry Droppings And Cassava Peels ...

    African Journals Online (AJOL)

    This greenhouse study was aimed at determining the potentials of poultry droppings (PD) and cassava peels (CP) for nutrient-enhanced biodegradation of petroleum hydrocarbon (THC) in a well drained Typic Paleustults using the THC levels and degradation duration as remediation indices. The performance of the organic ...

  17. Vapor condensation onto a non-volatile liquid drop

    Science.gov (United States)

    Inci, Levent; Bowles, Richard K.

    2013-12-01

    Molecular dynamics simulations of miscible and partially miscible binary Lennard-Jones mixtures are used to study the dynamics and thermodynamics of vapor condensation onto a non-volatile liquid drop in the canonical ensemble. When the system volume is large, the driving force for condensation is low and only a submonolayer of the solvent is adsorbed onto the liquid drop. A small degree of mixing of the solvent phase into the core of the particles occurs for the miscible system. At smaller volumes, complete film formation is observed and the dynamics of film growth are dominated by cluster-cluster coalescence. Mixing into the core of the droplet is also observed for partially miscible systems below an onset volume suggesting the presence of a solubility transition. We also develop a non-volatile liquid drop model, based on the capillarity approximations, that exhibits a solubility transition between small and large drops for partially miscible mixtures and has a hysteresis loop similar to the one observed in the deliquescence of small soluble salt particles. The properties of the model are compared to our simulation results and the model is used to study the formulation of classical nucleation theory for systems with low free energy barriers.

  18. Vapor condensation onto a non-volatile liquid drop

    Energy Technology Data Exchange (ETDEWEB)

    Inci, Levent; Bowles, Richard K., E-mail: richard.bowles@usask.ca [Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9 (Canada)

    2013-12-07

    Molecular dynamics simulations of miscible and partially miscible binary Lennard–Jones mixtures are used to study the dynamics and thermodynamics of vapor condensation onto a non-volatile liquid drop in the canonical ensemble. When the system volume is large, the driving force for condensation is low and only a submonolayer of the solvent is adsorbed onto the liquid drop. A small degree of mixing of the solvent phase into the core of the particles occurs for the miscible system. At smaller volumes, complete film formation is observed and the dynamics of film growth are dominated by cluster-cluster coalescence. Mixing into the core of the droplet is also observed for partially miscible systems below an onset volume suggesting the presence of a solubility transition. We also develop a non-volatile liquid drop model, based on the capillarity approximations, that exhibits a solubility transition between small and large drops for partially miscible mixtures and has a hysteresis loop similar to the one observed in the deliquescence of small soluble salt particles. The properties of the model are compared to our simulation results and the model is used to study the formulation of classical nucleation theory for systems with low free energy barriers.

  19. Millikan's Oil-Drop Experiment as a Remotely Controlled Laboratory

    Science.gov (United States)

    Eckert, Bodo; Grober, Sebastian; Vetter, Martin; Jodl, Hans-Jorg

    2012-01-01

    The Millikan oil-drop experiment, to determine the elementary electrical charge e and the quantization of charge Q = n [middle dot] e, is an essential experiment in physics teaching but it is hardly performed in class for several reasons. Therefore, we offer this experiment as a remotely controlled laboratory (RCL). We describe the interactivity…

  20. Mesophilic Co-Digestion of Cattle Paunch with Poultry Droppings ...

    African Journals Online (AJOL)

    Cattle paunch and poultry droppings are wastes that have posed environmental hazards due to poor management and disposal strategies in most municipal abattoirs and livestock farms in Nigeria. Utilization of these wastes for energy production at small and/or large scale requires assessment to ascertain the optimal mix.

  1. Effects of fertilizer phosphorus and poultry droppings treatments on ...

    African Journals Online (AJOL)

    Abstract. The effect of five phosphrous levels (0, 25, 50, 75, 100 and 125 kg/ha) and five poultry dropping (0, 100, 200, 300, 400 and 500 kg/ha) levels on the growth, growth yield, yield components, nutrients concentration and food values of pepper (Capsicum annuum L) were observed from 2002 to 2003 raining seasons.

  2. Don’t drop the patient: teamwork for cataract surgery

    Directory of Open Access Journals (Sweden)

    Daksha Patel

    2014-04-01

    Full Text Available The purpose of a team is to work together towards a common goal. On an athletics track, relay race teams run with a baton that is passed from one team member to another, without breaking the pace. If the baton is dropped, the team is disqualified.

  3. Effect of drop jump technique on the reactive strength index

    Directory of Open Access Journals (Sweden)

    Struzik Artur

    2016-09-01

    Full Text Available The basic drill of plyometric training aimed at improving lower limb power and jump height is a drop jump. This exercise can be performed using different techniques, which substantially affects jump variables. Therefore, the aim of this study was to compare the values of the reactive strength index (RSI for countermovement drop jumps (CDJs and bounce drop jumps (BDJs. The study was carried out in a group of 8 male youth basketball players. The tests were conducted using the AMTI BP600900 force plate to measure ground reaction forces and the Noraxon MyoMotion system to record kinematic data. Each player performed two CDJs and two BDJs from the height of 15, 30, 45 and 60 cm. The RSI was calculated as a ratio of jump height and contact time. Moreover, the RSI was determined for the amortization and take-off phases separately. Significant differences (p < 0.05 between RSI values for CDJs and BDJs were recorded for jumps from 30, 45 and 60 cm. Differences in RSI values for jumps from 15 cm were not significant. Furthermore, CDJ height values were significantly higher (p < 0.05 than the values recorded for BDJs. Times of contact, amortization and take-off during BDJs were significantly shorter (p < 0.05 than the respective values obtained for CDJs. Therefore, the use of the RSI to monitor plyometric training should be based on the drop jump technique that is commonly performed by basketball players.

  4. Drop Jumping as a Training Method for Jumping Ability

    NARCIS (Netherlands)

    Bobbert, Maarten F.

    1990-01-01

    Vertical jumping ability is of importance for good performance in sports such as basketball and volleyball. Coaches are in need of exercises that consume only little time and still help to improve their players’ jumping ability, without involving a high risk of injury. Drop jumping is assumed to

  5. A Novel Virus Causes Scale Drop Disease in Lates calcarifer

    NARCIS (Netherlands)

    Groof, A.; Guelen, L.; Deijs, M.; Wal, van der Y.; Miyata, M.; Ng, K.S.; Grinsven, van L.; Simmelink, B.; Biermann, Y.; Grisez, L.; Lent, van J.W.M.; Ronde, de A.; Chang, S.F.; Schrier, C.; Hoek, L.

    2015-01-01

    From 1992 onwards, outbreaks of a previously unknown illness have been reported in Asian seabass (Lates calcarifer) kept in maricultures in Southeast Asia. The most striking symptom of this emerging disease is the loss of scales. It was referred to as scale drop syndrome, but the etiology remained

  6. Detection of bubble nucleation event in superheated drop detector ...

    Indian Academy of Sciences (India)

    The present work demonstrates the detection of bubble nucleation events by using the pressure sensor. The associated circuits for the measurement are described in this article. The detection of events is verified by measuring the events with the acoustic sensor. The measurement was done using drops of various sizes to ...

  7. Determination of pressure drop across activated carbon fiber respirator cartridges.

    Science.gov (United States)

    Balanay, Jo Anne G; Lungu, Claudiu T

    2016-01-01

    Activated carbon fiber (ACF) is considered as an alternative adsorbent to granular activated carbon (GAC) for the development of thinner, lighter, and efficient respirators because of their larger surface area and adsorption capacities, thinner critical bed depth, lighter weight, and fabric form. This study aims to measure the pressure drop across different types of commercially available ACFs in respirator cartridges to determine the ACF composition and density that will result in acceptably breathable respirators. Seven ACF types in cloth (ACFC) and felt (ACFF) forms were tested. ACFs in cartridges were challenged with pre-conditioned constant air flow (43 LPM, 23°C, 50% RH) at different compositions (single- or combination-ACF type) in a test chamber. Pressure drop across ACF cartridges were obtained using a micromanometer, and compared among different cartridge configurations, to those of the GAC cartridge, and to the NIOSH breathing resistance requirements for respirator cartridges. Single-ACF type cartridges filled with any ACFF had pressure drop measurements (23.71-39.93 mmH2O) within the NIOSH inhalation resistance requirement of 40 mmH2O, while those of the ACFC cartridges (85.47±3.67 mmH2O) exceeded twice the limit due possibly to the denser weaving of ACFC fibers. All single ACFF-type cartridges had higher pressure drop compared to the GAC cartridge (23.13±1.14 mmH2O). Certain ACF combinations (2 ACFF or ACFC/ACFF types) resulted to pressure drop (26.39-32.81 mmH2O) below the NIOSH limit. All single-ACFF type and all combination-ACF type cartridges with acceptable pressure drop had much lower adsorbent weights than GAC (≤15.2% of GAC weight), showing potential for light-weight respirator cartridges. 100% ACFC in cartridges may result to respirators with high breathing resistance and, thus, is not recommended. The more dense ACFF and ACFC types may still be possibly used in respirators by combining them with less dense ACFF materials and/or by

  8. Reconsidering Styles of Regulatory Enforcement

    DEFF Research Database (Denmark)

    May, Peter J.; Winter, Søren

    2000-01-01

    This study addresses enforcement styles of regulatory inspectors, based on an examination of the municipal enforcement of agro-environmental policies in Denmark. Our findings make three contributions to the regulatory literature. One contribution is to add empirical support for theorizing about...

  9. Disclosure as a regulatory tool

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig

    2006-01-01

    The chapter analyses how disclure can be used as a regulatory tool and analyses how it has been applied so far in the area of financial market law and consumer law.......The chapter analyses how disclure can be used as a regulatory tool and analyses how it has been applied so far in the area of financial market law and consumer law....

  10. Regulatory focus in groupt contexts

    NARCIS (Netherlands)

    Faddegon, Krispijn Johannes

    2009-01-01

    The thesis examines the influence of group processes on the regulatory focus of individual group members. It is demonstrated that the group situation can affect group members' regulatory focus both in a top-down fashion (via the identitiy of the group) and in a bottom-up fashion (emerging from the

  11. Reconsidering Styles of Regulatory Enforcement

    DEFF Research Database (Denmark)

    J. May, Peter; Winter, Søren

    2007-01-01

    This study addresses enforcement styles of regulatory inspectors based on an examination of the municipal enforcement of agro-environmental policies in Denmark. Our findings make three contributions to the regulatory literature. One contribution is to add empirical support for theorizing about...

  12. Inhibition of Condensation Frosting by Arrays of Hygroscopic Antifreeze Drops.

    Science.gov (United States)

    Sun, Xiaoda; Damle, Viraj G; Uppal, Aastha; Linder, Rubin; Chandrashekar, Sriram; Mohan, Ajay R; Rykaczewski, Konrad

    2015-12-29

    The formation of frost and ice can have negative impacts on travel and a variety of industrial processes and is typically addressed by dispensing antifreeze substances such as salts and glycols. Despite the popularity of this anti-icing approach, some of the intricate underlying physical mechanisms are just being unraveled. For example, recent studies have shown that in addition to suppressing ice formation within its own volume, an individual salt saturated water microdroplet forms a region of inhibited condensation and condensation frosting (RIC) in its surrounding area. This occurs because salt saturated water, like most antifreeze substances, is hygroscopic and has water vapor pressure at its surface lower than water saturation pressure at the substrate. Here, we demonstrate that for macroscopic drops of propylene glycol and salt saturated water, the absolute RIC size can remain essentially unchanged for several hours. Utilizing this observation, we demonstrate that frost formation can be completely inhibited in-between microscopic and macroscopic arrays of propylene glycol and salt saturated water drops with spacing (S) smaller than twice the radius of the RIC (δ). Furthermore, by characterizing condensation frosting dynamics around various hygroscopic drop arrays, we demonstrate that they can delay complete frosting over of the samples 1.6 to 10 times longer than films of the liquids with equivalent volume. The significant delay in onset of ice nucleation achieved by dispensing propylene glycol in drops rather than in films is likely due to uniform dilution of the drops driven by thermocapillary flow. This transport mode is absent in the films, leading to faster dilution, and with that facilitated homogeneous nucleation, near the liquid-air interface.

  13. Quantitative effect and regulatory function of cyclic adenosine 5 ...

    Indian Academy of Sciences (India)

    Cyclic adenosine 5′-phosphate (cAMP) is a global regulator of gene expression in Escherichia coli. Despite decades of intensive study, the quantitative effect and regulatory function of cAMP remain the subjects of considerable debate. Here, we analyse the data in the literature to show that: In carbon-limited cultures ...

  14. 47 CFR 1.1157 - Payment of charges for regulatory fees.

    Science.gov (United States)

    2010-10-01

    ... may be cancelled. (d) Any Commercial Mobile Radio Service (CMRS) licensee subject to payment of an... 47 Telecommunication 1 2010-10-01 2010-10-01 false Payment of charges for regulatory fees. 1.1157... of Statutory Charges and Procedures for Payment § 1.1157 Payment of charges for regulatory fees...

  15. High-Throughput Single-Cell Labeling (Hi-SCL for RNA-Seq Using Drop-Based Microfluidics.

    Directory of Open Access Journals (Sweden)

    Assaf Rotem

    Full Text Available The importance of single-cell level data is increasingly appreciated, and significant advances in this direction have been made in recent years. Common to these technologies is the need to physically segregate individual cells into containers, such as wells or chambers of a micro-fluidics chip. High-throughput Single-Cell Labeling (Hi-SCL in drops is a novel method that uses drop-based libraries of oligonucleotide barcodes to index individual cells in a population. The use of drops as containers, and a microfluidics platform to manipulate them en-masse, yields a highly scalable methodological framework. Once tagged, labeled molecules from different cells may be mixed without losing the cell-of-origin information. Here we demonstrate an application of the method for generating RNA-sequencing data for multiple individual cells within a population. Barcoded oligonucleotides are used to prime cDNA synthesis within drops. Barcoded cDNAs are then combined and subjected to second generation sequencing. The data are deconvoluted based on the barcodes, yielding single-cell mRNA expression data. In a proof-of-concept set of experiments we show that this method yields data comparable to other existing methods, but with unique potential for assaying very large numbers of cells.

  16. Single-drop microextraction followed by in-drop derivatization for the analysis of organic compounds by gas chromatography

    Directory of Open Access Journals (Sweden)

    Constantine Stalikas

    2007-12-01

    Full Text Available Microextraction has become a buzz word in the recent years in the scientific area of analytical chemistry. Over the last decade, newer miniaturised approaches to liquid extraction have emerged, resulting in solvent and sample savings and less time consuming analysis. Single-drop microextraction (SDME has been developed as a viable and easy-to-use method based on the partitioning between sample matrix and organic droplet phase. However, there are numerous examples where analytical derivatizations are required to enhance sensitivity, selectivity, extraction efficiency and overall quality of the data. Improvements resulting from derivatization in instrumental methods are well known. The absence of data in chemical reaction accompanied by mass-transfer in liquid-liquid and gas-liquid microextraction, calls for a meticulous treatment of SDME in-drop derivatization for the purpose of analytical implementation. Leveraging the inherent characteristics of an organic microdrop as a tiny reactor, a threefold aim is set out in order: Ι. to develop a theoretical approximation to the in-drop derivatization SDME using phenolic compounds for liquid-liquid and two aldehydes for gas-liquid, as model compounds, II. to gauge the significance of mass-transfer and chemical reaction in an organic drop viewed as an analytical reactor and III. to underscore the importance of the a priori knowledge of the characteristics of such a system related to its analytical aspects.

  17. Regulatory Streamlining and Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Carl

    2006-07-11

    The Interstate Oil and Gas Compact Commission (IOGCC) engaged in numerous projects outlined under the scope of work discussed in the United States Department of Energy (DOE) grant number DE-FC26-04NT15456 awarded to the IOGCC. Numerous projects were completed that were extremely valuable to state oil and gas agencies as a result of work performed utilizing resources provided by the grant. There are numerous areas in which state agencies still need assistance. This additional assistance will need to be addressed under future scopes of work submitted annually to DOE's Project Officer for this grant. This report discusses the progress of the projects outlined under the grant scope of work for the 2005-2006 areas of interest, which are as follows: Area of Interest No. 1--Regulatory Streamlining and Improvement: This area of interest continues to support IOGCC's regulatory streamlining efforts that include the identification and elimination of unnecessary duplications of efforts between and among state and federal programs dealing with exploration and production on public lands. Area of Interest No. 2--Technology: This area of interest seeks to improve efficiency in states through the identification of technologies that can reduce costs. Area of Interest No. 3--Training and Education: This area of interest is vital to upgrading the skills of regulators and industry alike. Within the National Energy Policy, there are many appropriate training and education opportunities. Education was strongly endorsed by the President's National Energy Policy Development group. Acting through the governors offices, states are very effective conduits for the dissemination of energy education information. While the IOGCC favors the development of a comprehensive, long-term energy education plan, states are also supportive of immediate action on important concerns, such as energy prices, availability and conservation. Area of Interest No. 4--Resource Assessment and

  18. Drop Tower Facility at Queensland University of Technology

    Science.gov (United States)

    Plagens, Owen; Castillo, Martin; Steinberg, Theodore; Ong, Teng-Cheong

    The Queensland University of Technology (QUT) Drop Tower Facility is a {raise.17exscriptstyle˜}2.1 second, 21.3 m fall, dual capsule drop tower system. The dual capsule comprises of an uncoupled exterior hollow drag shield that experiences drag by the ambient atmosphere with the experimental capsule falling within the drag shield. The dual capsule system is lifted to the top of the drop tower via a mechanical crane and the dropping process is initiated by the cutting of a wire coupling the experimental package and suspending the drag shield. The internal experimental capsule reaches the bottom of the drag shield floor just prior to the deceleration stage at the air bag and during this time experience gravity levels of {raise.17exscriptstyle˜}10textsuperscript{-6} g. The deceleration system utilizes an inflatable airbag where experimental packages can be designed to experience a maximum deceleration of {raise.17exscriptstyle˜}10textsuperscript{18} g for {raise.17exscriptstyle˜}0.1 seconds. The drag shield can house experimental packages with a maximum diameter of 0.8 m and height of 0.9 m. The drag shield can also be used in foam mode, where the walls are lined with foam and small experiments can be dropped completely untethered. This mode is generally used for the study of microsatellite manipulation. Payloads can be powered by on-board power systems with power delivered to the experiment until free fall occurs. Experimental data that can be collected includes but is not limited to video, temperature, pressure, voltage/current from the power supply, and triggering mechanisms outputs which are simultaneously collected via data logging systems and high speed video recording systems. Academic and commercial projects are currently under investigation at the QUT Drop Tower Facility and collaboration is openly welcome at this facility. Current research includes the study of heterogeneously burning metals in oxygen which is aimed at fire safety applications and

  19. Four-point potential drop measurements for materials characterization

    Science.gov (United States)

    Bowler, Nicola

    2011-01-01

    The technique of measuring the voltage difference (potential drop) between two of the four electrodes of a four-point probe, in order to determine conductivity or surface resistivity of a test piece, is well established in the direct-current (dc) or quasi-dc regime. The technique finds wide usage in the semiconductor industry for the purpose of measuring surface resistivity of semiconductors, and also in the measurement of conductivity of metals, particularly of ferromagnetic metals for which conductivity cannot be easily measured using eddy-current nondestructive evaluation (NDE). In these applications, the conductivity of the test piece is deduced from an analytic formula that depends on the geometry of the probe and test piece. Such a formula requires, as an input, the measured value of the potential drop. Several analytical expressions exist for a variety of test-piece geometries and probe arrangements. Recently, it has been shown that broadband measurements of the potential drop, known as 'alternating current potential drop' (ac PD) measurements, can be used not only to obtain the conductivity of a test piece, but also its linear permeability μ. The beauty of this measurement is that the two parameters are completely decoupled in the quasi-static regime. In fact, μ does not appear in the quasi-static expression for σ. Hence, σ may be obtained from low-frequency ac PD measurements and then μ may be deduced as the frequency increases beyond the quasi-static regime, once σ is known. In this review, both dc and ac solutions that are useful in determining the conductivity of metals and semiconductors, and the permeability of ferromagnetic conductors, are summarized. In particular, flat test pieces with arbitrary thickness are considered. At the next level of complexity, a solution for a half-space coated with a surface layer is given, along with a discussion of the use of the four-point potential drop method for determining thickness of a surface layer, such

  20. 75 FR 77879 - Determination of Regulatory Review Period for Purposes of Patent Extension; SAMSCA

    Science.gov (United States)

    2010-12-14

    ..., animal drug product, medical device, food additive, or color additive) was subject to regulatory review...) from Otsuka Pharmaceutical Co., Ltd., and the Patent and Trademark Office requested FDA's assistance in...

  1. Fast H-DROP: A thirty times accelerated version of H-DROP for interactive SVM-based prediction of helical domain linkers

    Science.gov (United States)

    Richa, Tambi; Ide, Soichiro; Suzuki, Ryosuke; Ebina, Teppei; Kuroda, Yutaka

    2017-02-01

    Efficient and rapid prediction of domain regions from amino acid sequence information alone is often required for swift structural and functional characterization of large multi-domain proteins. Here we introduce Fast H-DROP, a thirty times accelerated version of our previously reported H-DROP (Helical Domain linker pRediction using OPtimal features), which is unique in specifically predicting helical domain linkers (boundaries). Fast H-DROP, analogously to H-DROP, uses optimum features selected from a set of 3000 ones by combining a random forest and a stepwise feature selection protocol. We reduced the computational time from 8.5 min per sequence in H-DROP to 14 s per sequence in Fast H-DROP on an 8 Xeon processor Linux server by using SWISS-PROT instead of Genbank non-redundant (nr) database for generating the PSSMs. The sensitivity and precision of Fast H-DROP assessed by cross-validation were 33.7 and 36.2%, which were merely 2% lower than that of H-DROP. The reduced computational time of Fast H-DROP, without affecting prediction performances, makes it more interactive and user-friendly. Fast H-DROP and H-DROP are freely available from http://domserv.lab.tuat.ac.jp/.

  2. Internationalization of regulatory requirements.

    Science.gov (United States)

    Juillet, Y

    2003-02-01

    The aim of harmonisation of medicines regulatory requirements is to allow the patient quicker access to new drugs and to avoid animal and human duplications. Harmonisation in the European Union (EU) is now completed, and has led to the submission of one dossier in one language study leading to European marketing authorizations, thanks in particular to efficacy guidelines published at the European level. With the benefit of the European experience since 1989, more than 40 guidelines have been harmonised amongst the EU, Japan and the USA through the International Conference on Harmonisation (ICH). ICH is a unique process gathering regulators and industry experts from the three regions. Its activity is built on expertise and trust. The Common Technical Document (CTD), an agreed common format for application in the three regions, is a logical follow-up to the ICH first phase harmonising the content of the dossier. The CTD final implementation in July 2003 will have considerable influence on the review process and on the exchange of information in the three regions.

  3. Healthcare regulatory concepts in Brazil.

    Science.gov (United States)

    Oliveira, Robson Rocha de; Elias, Paulo Eduardo Mangeon

    2012-06-01

    The healthcare regulatory concepts used in Brazilian scientific publications on healthcare management were reviewed. A typo-logical classification for regulatory concepts was developed from the most current ideas in five disciplines: life sciences, law, economics, sociology and political science. Four ideas stood out: control, balance, adaptation and direction, with greatest emphasis on the technical nature of regulation. The political nature of regulation was secondary. It was considered that dis-cussion of healthcare regulatory concepts was connected with comprehension of the role that the state plays in this sector. De-finition of the forms of state intervention is the key convergence point between the different ways of conceptualizing healthcare regulation.

  4. Fluorimetric quantification of brimonidine tartrate in eye drops.

    Science.gov (United States)

    Sunitha, G; Bhagirath, R; Alapati, V R; Ramakrishna, K; Subrahmanyam, C V S; Anumolu, P D

    2013-11-01

    A simple and sensitive spectrofluorimetric method has been developed for the estimation of brimonidine tartrate in pure and eye drops. Linearity was obeyed in the range of 0.2-3.0 ΅g/ml in dimethyl formamide as solvent at an emission wavelength (λem) of 530 nm after excitation wavelength (λex) of 389 nm with good correlation coefficient of 0.998. The limit of detection and limit of quantification for this method were 22.0 and 72.0 ng/ml, respectively. The developed method was statistically validated as per International Conference on Harmonisation guidelines. The percentage relative standard deviation values were found to be less than 2 for accuracy and precision studies. The results obtained were in good agreement with the labelled amounts of the marketed formulations. The proposed method was effectively applied to routine quality control analysis of brimonidine tartrate in their eye drops.

  5. Dynamics of sessile drops. Part 3. Theory of forced oscillations

    CERN Document Server

    Bostwick, Joshua B

    2016-01-01

    A partially-wetting sessile drop is driven by a sinusoidal pressure field that produces capillary waves on the liquid/gas interface. The analysis presented in Part 1 of this series (Bostwick & Steen 2014) is extended by computing response diagrams and phase shifts for the viscous droplet, whose three phase contact-line moves with contact-angle that is a smooth function of the contact line speed. Viscous dissipation is incorporated through the viscous potential flow approximation and the critical Ohnesorge number bounding regions beyond which a given mode becomes over-damped is computed. Davis dissipation originating from the contact-line speed condition leads to damped oscillations for drops with finite contact-line mobility, even for inviscid fluids. The critical mobility and associated driving frequency to generate the largest Davis dissipation is computed. Lastly, regions of modal coexistence where two modes can be simultaneously excited by a single forcing frequency are identified. Predictions compare...

  6. Influence of gravity on the solidification of a drop

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, A.; Meseguer, J.; Mayo, L.

    1987-03-01

    In this paper the influence of gravity on the solidification of a drop formed at the end of a rod is analyzed. Although similar studies (but ignoring gravity effects) already exist, a theoretical analysis including gravity effects allows one to improve the experimental procedure to measure on Earth relevant properties of crystals (mainly the receding contact angle phi/sub i/) which are of importance in shaped crystal growth processes. One of the main results here obtained are the shapes of the solidified drops, which are strongly dependent on the value of phi/sub i/. Therefore, fitting theoretical shapes to experimental ones is a way to perform accurate measurements of phi/sub i/.

  7. Virtual prototyping of drop test using explicit analysis

    Science.gov (United States)

    Todorov, Georgi; Kamberov, Konstantin

    2017-12-01

    Increased requirements for reliability and safety, included in contemporary standards and norms, has high impact over new product development. New numerical techniques based on virtual prototyping technology, facilitates imrpoving product development cycle, resutling in reduced time/money spent for this stage as well as increased knowledge about certain failure mechanism. So called "drop test" became nearly a "must" step in development of any human operated product. This study aims to demonstrate dynamic behaviour assessment of a structure under impact loads, based on virtual prototyping using a typical nonlinear analysis - explicit dynamics. An example is presneted, based on a plastic container that is used as cartridge for a dispenser machine exposed to various work conditions. Different drop orientations were analyzed and critical load cases and design weaknesses have been found. Several design modifications have been proposed, based on detailed analyses results review.

  8. Surgical outcome for foot drop in lumbar degenerative disease.

    Science.gov (United States)

    Bhargava, Deepti; Sinha, Priyank; Odak, Saurabh; Tyagi, Atul; Towns, Gerry; Pal, Debasish

    2012-09-01

    Controversy exists regarding the timing and outcome of surgery for lumbar degenerative disease (LDD) associated with foot drop. In this work, we report the results of a retrospective observational study from our center. We had a sample size of 26 patients with a minimum follow-up of 6 months. Of the 26 patients, 88% improved, with complete recovery observed in 61%. Thus, our data support the view that there is good recovery from operative management of foot drop secondary to LDD. Adjusting for preoperative strength, preoperative duration of weakness was a significant predictor of extent of recovery (odds ratio = 0.93; 95% confidence interval 0.88 to 0.98; p = 0.019). The model explained 50% of the variance in outcome in this study.

  9. Hanging drop cultures of human testis and testis cancer samples

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Young, J; Nielsen, J E

    2014-01-01

    limited by the lack of experimental models. The aim of this study was to establish an experimental tissue culture model to maintain normal and malignant germ cells within their niche and allow investigation of treatment effects. METHODS: Human testis and testis cancer specimens from orchidectomies were...... cultured in 'hanging drops' and effects of activin A and follistatin treatment were investigated in seminoma cultures. RESULTS: Testis fragments with normal spermatogenesis or CIS cells were cultured for 14 days with sustained proliferation of germ cells and CIS cells and without increased apoptosis....... Seminoma cultures survived 7 days, with proliferating cells detectable during the first 5 days. Activin A treatment significantly reduced KIT transcript and protein levels in seminoma cultures, thereby demonstrating a specific treatment response. CONCLUSIONS: Hanging drop cultures of human testis...

  10. Assessment of the relative error in the automation task by sessile drop method

    Directory of Open Access Journals (Sweden)

    T. О. Levitskaya

    2015-11-01

    Full Text Available Assessment of the relative error in the sessile drop method automation. Further development of the sessile drop method is directly related to the development of new techniques and specially developed algorithms enabling automatic computer calculation of surface properties. The sessile drop method mathematical apparatus improvement, drop circuit equation transformation to a form suitable for working, the drop surface calculation method automation, analysis of relative errors in the calculation of surface tension are relevant and are important in experimental determinations. The surface tension measurement relative error, as well as the error caused by the drop ellipsoidness in the plan were determined in the task of the sessile drop automation. It should be noted that if the drop maximum diameter (l is big or if the ratio of l to the drop height above the equatorial diameter(h is big, the relative error in the measurement of surface tension by sessile drop method does not depend much on the equatorial diameter of the drop and ellipsoidness of the drop. In this case, the accuracy of determination of the surface tension varies from 1,0 to 0,5%. At lower values the drop ellipsoidness begins to affect the relative error of surface tension (from 1,2 to 0,8%, but in this case the drop ellipsoidness is less. Therefore, in subsequent experiments, we used larger drops. On the basis of the assessment of the relative error in determining the liquid surface tension by sessile drop method caused by drop ellipsoidness in the plan, the tables showing the limits of the drop parameters (h and l measurement necessary accuracy to get the overall relative error have been made up. Previously, the surface tension used to be calculated with the relative error in the range of 2-3%

  11. The Danish Regulatory Reform of Telecommunications

    DEFF Research Database (Denmark)

    Skouby, Knud Erik

    1998-01-01

    An overview of the liberalisation process and regulatory reform of telecommunications in Denmark......An overview of the liberalisation process and regulatory reform of telecommunications in Denmark...

  12. Fundamental Studies of Jumping-Drop Thermal Diodes

    Science.gov (United States)

    2016-02-29

    injection and vacuum pumping (visible in Figure 2a inset). The opposing superhydrophilic surface (Figure 2b) consisted of copper wick sintered to a...sectional area as the diode (76 mm x 76 mm). The backside of the heater was wrapped with insulating rubber foam to minimize heat leakage. The cooling was...and heated, so there would be no jumping drops. Note that the heater plate and the insulating foam were removed from the images in Figure 4 (a) and

  13. How to Make a Microgravity Drop Tower for Your Classroom

    Science.gov (United States)

    DeLombard, Richard; Hall, Nancy R.

    2014-01-01

    Microgravity is quite often seen as exotic and special as astronauts float around in the International Space Station, eating MM's in mid-air, and performing science experiments, all done seemingly without gravity being present. Surprisingly enough, up on the ISS there is about 90 of the same gravity that holds you to the floor in your classroom or museum exhibit hall. Participate in this session and you will understand that and more. You can use simple devices to demonstrate microgravity conditions in your classroom or museum exhibit hall. This will be the same microgravity condition that astronauts experience on the ISS, just for a much shorter period of time. Contrary to popular opinion of some people, microgravity is NOT caused by zero gravity up there. Microgravity on the ISS is due to free fall within the Earth's gravitational field. That means you can drop an item in free fall in your classroom and museum exhibit hall and that item will experience microgravity. In this session, a short theory segment will explain and reinforce these concepts so that you may explain to others. The session will concentrate on showing the session participants how to make an effective, but inexpensive, drop tower for use in the classroom. Such a drop tower may be used to reinforce classroom instruction in physics and forces motion as well as serve as a platform for student investigations, classroom competitions, and student science or technology fair entries. Session participants will build their own simple microgravity experiment and operate them in a drop tower, compare results, and modify their experiment based on results. This material is also useful for public demonstrations at school open houses, travelling museum exhibits, fixed museum exhibits, and independent student projects or experiments. These free fall concepts also connect terrestrial demonstrations with planetary moon motion, comet trajectory, and more.

  14. Topical dobesilate eye drops for ophthalmic primary pterygium.

    Science.gov (United States)

    Cuevas, Pedro; Outeiriño, Luis A; Angulo, Javier; Giménez-Gallego, Guillermo

    2012-03-08

    Selective inhibition of fibroblast growth factor and vascular endothelial growth factor signalling pathways is effective in causing regression of pterygia. Prompt regression of fibrovascular mass and conjunctival angiogenesis was documented 2 weeks after topical administration of dobesilate eye drops twice daily. At 3-month follow-up, no recurrence was seen and no ocular irritation and burning were noted. The authors believe that this is the first known successful use of topical dobesilate in primary pterygium.

  15. Topical dobesilate eye drops for ophthalmic primary pterygium

    OpenAIRE

    Cuevas, Pedro; Outeiriño, Luis A; Angulo, Javier; Giménez-Gallego, Guillermo

    2012-01-01

    Selective inhibition of fibroblast growth factor and vascular endothelial growth factor signalling pathways is effective in causing regression of pterygia. Prompt regression of fibrovascular mass and conjunctival angiogenesis was documented 2 weeks after topical administration of dobesilate eye drops twice daily. At 3-month follow-up, no recurrence was seen and no ocular irritation and burning were noted. The authors believe that this is the first known successful use of topical dobesilate in...

  16. Drop impact upon micro- and nanostructured superhydrophobic surfaces

    OpenAIRE

    Tsai, Peichun; Pacheco, Sergio; Pirat, Christophe; Lefferts, Leon; Lohse, Detlef

    2009-01-01

    We experimentally investigate drop impact dynamics onto different superhydrophobic surfaces, consisting of regular polymeric micropatterns and rough carbon nanofibers, with similar static contact angles. The main control parameters are the Weber number \\We and the roughness of the surface. At small \\We, i.e. small impact velocity, the impact evolutions are similar for both types of substrates, exhibiting Fakir state, complete bouncing, partial rebouncing, trapping of an air bubble, jetting, a...

  17. Probing the nanoscale: the first contact of an impacting drop

    KAUST Repository

    Li, Erqiang

    2015-11-16

    When a drop impacts onto a solid surface, the lubrication pressure in the air deforms its bottom into a dimple. This makes the initial contact with the substrate occur not at a point but along a ring, thereby entrapping a central disc of air. We use ultra-high-speed imaging, with 200 ns time resolution, to observe the structure of this first contact between the liquid and a smooth solid surface. For a water drop impacting onto regular glass we observe a ring of microbubbles, due to multiple initial contacts just before the formation of the fully wetted outer section. These contacts are spaced by a few microns and quickly grow in size until they meet, thereby leaving behind a ring of microbubbles marking the original air-disc diameter. On the other hand, no microbubbles are left behind when the drop impacts onto molecularly smooth mica sheets. We thereby conclude that the localized contacts are due to nanometric roughness of the glass surface, and the presence of the microbubbles can therefore distinguish between glass with 10 nm roughness and perfectly smooth glass. We contrast this entrapment topology with the initial contact of a drop impacting onto a film of extremely viscous immiscible liquid, where the initial contact appears to be continuous along the ring. Here, an azimuthal instability occurs during the rapid contraction at the triple line, also leaving behind microbubbles. For low impact velocities the nature of the initial contact changes to one initiated by ruptures of a thin lubricating air film.

  18. Surface tension of spherical drops from surface of tension

    Energy Technology Data Exchange (ETDEWEB)

    Homman, A.-A.; Bourasseau, E. [CEA/DAM DIF, F-91297 Arpajon Cedex (France); Stoltz, G. [Université Paris-Est, CERMICS (ENPC), INRIA, F-77455 Marne-la-Vallée (France); Malfreyt, P. [Institut de Chimie de Clermont-Ferrand, Université Blaise Pascal, UMR CNRS 6296, ICCF, BP 10448, F-63000 Clermont-Ferrand (France); Strafella, L.; Ghoufi, A., E-mail: aziz.ghoufi@univ-rennes1.fr [Institut de Physique de Rennes, Université de Rennes 1 UMR 6251 CNRS, 263 avenue Général Leclerc, 35042 Rennes (France)

    2014-01-21

    The determination of surface tension of curved interfaces is a topic that raised many controversies during the last century. Explicit liquid-vapor interface modelling (ELVI) was unable up to now to reproduce interfacial behaviors in drops due to ambiguities in the mechanical definition of the surface tension. In this work, we propose a thermodynamic approach based on the location of surface of tension and its use in the Laplace equation to extract the surface tension of spherical interfaces from ELVI modelling.

  19. Personality disorders and treatment drop out in the homeless

    OpenAIRE

    Salavera C; Tricás JM; Lucha O

    2013-01-01

    Carlos Salavera,1 José M Tricás,2 Orosia Lucha21Faculty of Education, University of Zaragoza, Zaragoza, Spain; 2Physiotherapy Research Unit, University of Zaragoza, Zaragoza, SpainAbstract: The homeless drop out of treatment relatively frequently. Also, prevalence rates of personality disorders are much higher in the homeless group than in the general population. We hypothesize that when both variables coexist – homelessness and personality disorders &ndash...

  20. A subjective scheduler for subjective dedicated networks

    Science.gov (United States)

    Suherman; Fakhrizal, Said Reza; Al-Akaidi, Marwan

    2017-09-01

    Multiple access technique is one of important techniques within medium access layer in TCP/IP protocol stack. Each network technology implements the selected access method. Priority can be implemented in those methods to differentiate services. Some internet networks are dedicated for specific purpose. Education browsing or tutorial video accesses are preferred in a library hotspot, while entertainment and sport contents could be subjects of limitation. Current solution may use IP address filter or access list. This paper proposes subjective properties of users or applications are used for priority determination in multiple access techniques. The NS-2 simulator is employed to evaluate the method. A video surveillance network using WiMAX is chosen as the object. Subjective priority is implemented on WiMAX scheduler based on traffic properties. Three different traffic sources from monitoring video: palace, park, and market are evaluated. The proposed subjective scheduler prioritizes palace monitoring video that results better quality, xx dB than the later monitoring spots.

  1. The Evopopbot Chip: Ultra High-throughput Evolutionary Population Bottlenecking using Drop-Based Microfluidics

    Science.gov (United States)

    Chang, Connie; Rotem, Assaf; Serohijos, Adrian; Zhang, Huidan; Tao, Ye; Fischer Hesselbrock, Audrey; Thielen, Peter; Mehoke, Thomas; Wolfe, Joshua; Wobus, Christiane; Feldman, Andrew; Shakhnovich, Eugene; Weitz, David

    2014-03-01

    The study of how viruses propagate is important for curing disease and preventing viral outbreaks. In nature, viruses can compete with one another, and the most evolutionary fit virus usually takes over a population. Yet there exist variants in the population that can escape subjected evolutionary pressures and eventually dominate the population. Successful studies of viral epidemics hinges on the ability to access these variants. Here, we present the use of droplet-based microfluidics as a simple method to segregate and propagate a viral population as individual viral lineages, simultaneously performing millions of in vitroevolutionary bottlenecking experiments. We introduce a novel microfluidic device, called the ``Evopopbot Chip'', that allows for simultaneous passaging of millions of evolutionary bottlenecking events by splitting drops containing previous generations of viruses and merging with drops containing new host cells. After several generations of viral replication in the evolution chip, we discover hundreds of new viruses that are able to escape a neutralizing antibody selection pressure compared to bulk passaging.

  2. A clinical trial of a prototype of wireless surface fes rehabilitation system in foot drop correction.

    Science.gov (United States)

    Miura, Naoto; Watanabe, Takashi; Akasaka, Kiyokazu; Suzuki, Tatsuto

    2011-01-01

    The purpose of this study is to develop a wireless FES rehabilitation system to assist effective improvement of the lower limbs. In this report, a prototype system combined with foot drop correction and gait evaluation using wireless surface electrical stimulator and the wireless inertial sensors was developed and tested with a right hemiplegic subject. For gait evaluation, lower limb joint angles and segment angles were estimated by the Kalman filter from the data measured with wireless inertial sensors. Electrical stimulation was applied to the common peroneal nerve or the tibialis anterior muscle by detecting stimulus timing automatically from the data of wireless inertial sensor attached on the shank of the hemiplegic side. The maximum joint angle of ankle dorsiflexion of the paralyzed side at the swing phase was increased approximately to the value of the healthy side by applying the electrical stimulation. The developed system was performed well in foot drop correction and the measured data of the inertial sensors showed the characteristics and difference of paralyzed side with and without electrical stimulation using the segment angles and joint angles.

  3. Support vector machine for classification of walking conditions of persons after stroke with dropped foot.

    Science.gov (United States)

    Lau, Hong-yin; Tong, Kai-yu; Zhu, Hailong

    2009-08-01

    Walking with dropped foot represents a major gait disorder, which is observed in hemiparetic persons after stroke. This study explores the use of support vector machine (SVMs) to classify different walking conditions for hemiparetic subjects. Seven participants with dropped foot (category 4 of functional ambulatory category) walked in five different conditions: level ground, stair ascent, stair descent, upslope, and downslope. The kinematic data were measured by two portable sensor units, each comprising an accelerometer and gyroscope attached to the lower limb on the shank and foot segments. The overall classification accuracy of stair ascent, stair descent, and other walking conditions was 92.9% using input features from the sensor attached to the shank. It was further improved to 97.5% by adding two more inputs from the sensor attached to the foot. Stair ascent was also classified by the inputs from the foot sensor unit with 96% accuracy. The performance of an SVM was shown to be superior to that of other machine learning methods using artificial neural networks (ANN) and radial basis function neural networks (RBF). The results suggested that the SVM classification method could be applied as a tool for pathological gait analysis, pattern recognition, control signals in functional electrical stimulation (FES) and rehabilitation robot, as well as activity monitoring during rehabilitation of daily activities.

  4. Application of Hanging Drop Technique for Kidney Tissue Culture.

    Science.gov (United States)

    Wang, Shaohui; Wang, Ximing; Boone, Jasmine; Wie, Jin; Yip, Kay-Pong; Zhang, Jie; Wang, Lei; Liu, Ruisheng

    2017-01-01

    The hanging drop technique is a well-established method used in culture of animal tissues. However, this method has not been used in adult kidney tissue culture yet. This study was to explore the feasibility of using this technique for culturing adult kidney cortex to study the time course of RNA viability in the tubules and vasculature, as well as the tissue structural integrity. In each Petri dish with the plate covered with sterile buffer, a section of mouse renal cortex was cultured within a drop of DMEM culture medium on the inner surface of the lip facing downward. The tissue were then harvested at each specific time points for Real-time PCR analysis and histological studies. The results showed that the mRNA level of most Na+ related transporters and cotransporters were stably maintained within 6 hours in culture, and that the mRNA level of most receptors found in the vasculature and glomeruli were stably maintained for up to 9 days in culture. Paraffin sections of the cultured renal cortex indicated that the tubules began to lose tubular integrity after 6 hours, but the glomeruli and vasculatures were still recognizable up to 9 days in culture. We concluded that adult kidney tissue culture by hanging drop method can be used to study gene expressions in vasculature and glomeruli. © 2017 The Author(s). Published by S. Karger AG, Basel.

  5. Drop weld thermal injuries to the middle ear.

    LENUS (Irish Health Repository)

    Keogh, I J

    2009-01-01

    Drop weld injuries to the tympanic membrane and middle ear caused by hot sparks or molten slag are a rare but significant injury. Steel workers and welders who are regularly exposed to flying sparks and molten metal slag are predisposed. This type of transtympanic thermal injury occurs when the slag literally drops into the external auditory canal and burns through the tympanic membrane. A spectrum of severity of injury occurs which includes chronic tympanic membrane perforation, chronic otorrhoea, facial nerve injury and deafness. Chronic tympanic membrane perforation is the most common sequelae and is perhaps one of the most challenging of all perforations to repair The combination of direct thermal injury and foreign body reaction results in continuing or recurrent suppuration. The foreign body reaction is due to the embedding of metal slag in the promontorial mucosa. We present a case of drop weld injury to the left tympanic membrane, resulting in chronic middle ear inflammation, otorrhoea and tympanic perforation. CAT scan clearly demonstrated a metallic promontorial foreign body with localised bone erosion. We emphasise the importance of removing these foreign bodies and recommend a cartilage reinforced underlay tympanoplasty technique to repair these perforations. Transtympanic thermal trauma is a preventable occupational injury, which is best, avoided by earplugs and increased awareness.

  6. Coalescence of liquid drops: Different models versus experiment

    KAUST Repository

    Sprittles, J. E.

    2012-01-01

    The process of coalescence of two identical liquid drops is simulated numerically in the framework of two essentially different mathematical models, and the results are compared with experimental data on the very early stages of the coalescence process reported recently. The first model tested is the "conventional" one, where it is assumed that coalescence as the formation of a single body of fluid occurs by an instant appearance of a liquid bridge smoothly connecting the two drops, and the subsequent process is the evolution of this single body of fluid driven by capillary forces. The second model under investigation considers coalescence as a process where a section of the free surface becomes trapped between the bulk phases as the drops are pressed against each other, and it is the gradual disappearance of this "internal interface" that leads to the formation of a single body of fluid and the conventional model taking over. Using the full numerical solution of the problem in the framework of each of the two models, we show that the recently reported electrical measurements probing the very early stages of the process are better described by the interface formation/disappearance model. New theory-guided experiments are suggested that would help to further elucidate the details of the coalescence phenomenon. As a by-product of our research, the range of validity of different "scaling laws" advanced as approximate solutions to the problem formulated using the conventional model is established. © 2012 American Institute of Physics.

  7. Modeling axisymmetric flows dynamics of films, jets, and drops

    CERN Document Server

    Middleman, Stanley

    1995-01-01

    This concise book is intended to fulfill two purposes: to provide an important supplement to classic texts by carrying fluid dynamics students on into the realm of free boundary flows; and to demonstrate the art of mathematical modeling based on knowledge, intuition, and observation. In the authors words, the overall goal is make the complex simple, without losing the essence--the virtue--of the complexity.Modeling Axisymmetric Flows: Dynamics of Films, Jets, and Drops is the first book to cover the topics of axisymmetric laminar flows; free-boundary flows; and dynamics of drops, jets, and films. The text also features comparisons of models to experiments, and it includes a large selection of problems at the end of each chapter.Key Features* Contains problems at the end of each chapter* Compares real-world experimental data to theory* Provides one of the first comprehensive examinations of axisymmetric laminar flows, free-boundary flows, and dynamics of drops, jets, and films* Includes development of basic eq...

  8. Kinetic asymmetries between forward and drop jump landing tasks

    Directory of Open Access Journals (Sweden)

    Morgana Alves de Britto

    2015-11-01

    Full Text Available Landing asymmetry is a risk factor for knee anterior cruciate ligament injury. The aim of this study was to identify kinetic asymmetries in healthy recreational athletes performing different jump-landing techniques. Twelve recreational athletes engaged in regular training underwent kinetic evaluation using two 3D force plates and were analyzed for: (a three-dimensional peak forces, (b time to peak vertical force, and (c initial phase asymmetries. All data were collected during performance of unilateral and bilateral trials of forward and drop jump tasks. Forward jump-landing tasks elicited greater kinetic asymmetry than drop-landing tasks. Regardless of jump-landing technique, the preferred leg experienced higher forces than the non-preferred leg. The initial landing phase showed more kinetic asymmetries than the later phase when peak vertical forces occur. It was concluded that when screening athletes for kinetic asymmetries that may predispose them to injury, forward jump-landing tasks and the early landing phase might show more kinetic asymmetries than drop jump-landing tasks and the late landing phase, respectively.

  9. Viscous Effect of Drop Impacting on Liquid Film

    Science.gov (United States)

    Tang, Xiaoyu; Saha, Abhishek; Law, Chung K.; Sun, Chao

    2017-11-01

    Drop impacting a liquid film is commonly observed in many processes including inkjet printing and thermal sprays. The accumulation and growth of the film depend on the outcome of subsequent drop impact on the initially formed film. In our recent study (Tang, et al. Soft Matter 2016), we have proposed a regime diagram based on the Weber number We (ratio of impact inertia and surface tension) and the film thickness, characterizing non-monotonic transitions between the bouncing and merging outcomes and providing scaling analysis for the boundaries for a single liquid (n-tetradecane). Since liquid viscosity fundamentally affects the impact outcome, through its influence on the flow field and dissipation of the kinetic energy, here we extend the study for a number of alkanes and silicone oils, covering a wide range of viscosity, to evaluate its effect on the regime diagram. We will show that while the regime diagram maintains its general structure, the merging regime becomes smaller for more viscous liquids and eventually the non-monotonicity disappears. We will model the viscous effects and present a modified scaling. This new scaling attempts to unify all liquids and provides a useful tool to manipulate the outcome of drop impact on liquid film. The work at Princeton University is supported by the Army Research Office and the Xerox Corporation.

  10. Kinetic asymmetries between forward and drop jump landing tasks

    Directory of Open Access Journals (Sweden)

    Morgana Alves de Britto

    2015-12-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n6p661   Landing asymmetry is a risk factor for knee anterior cruciate ligament injury. The aim of this study was to identify kinetic asymmetries in healthy recreational athletes performing different jump-landing techniques. Twelve recreational athletes engaged in regular training underwent kinetic evaluation using two 3D force plates and were analyzed for: (a three-dimensional peak forces, (b time to peak vertical force, and (c initial phase asymmetries. All data were collected during performance of unilateral and bilateral trials of forward and drop jump tasks. Forward jump-landing tasks elicited greater kinetic asymmetry than drop-landing tasks. Regardless of jump-landing technique, the preferred leg experienced higher forces than the non-preferred leg. The initial landing phase showed more kinetic asymmetries than the later phase when peak vertical forces occur. It was concluded that when screening athletes for kinetic asymmetries that may predispose them to injury, forward jump-landing tasks and the early landing phase might show more kinetic asymmetries than drop jump-landing tasks and the late landing phase, respectively.

  11. Electromagnetic radiation from linearly and nonlinearly oscillating charge drops

    Science.gov (United States)

    Grigor'ev, A. I.; Shiryaeva, S. O.

    2016-12-01

    It has been shown that analytic calculations of the intensity of electromagnetic radiation from an oscillating charged drop in the approximation linear in the oscillation amplitude (small parameter is on the order of 0.1) give only the quadrupole component of the total radiation. The dipole component can only be obtained in calculations using higher-order approximations. Nevertheless, the intensity of the dipole radiation turns out to be substantially higher (by 14-15 orders of magnitude). This is because the decomposition of radiation from a system of charges into multipole components (differing even in the rates of decrease in the potential with the distance) is carried out using the expansion in a substantially smaller parameter, viz., the ratio of the size of the emitting system (in our case, a drop of radius 10 μm) to the distance to the point of observation in the wave zone of the emission of radiation (emitted wavelength) of 100-1000 m. As a result, this second small parameter is on the order of 10-7 to 10-8. On the other hand, in accordance with the field theory, the ratio of intensities of quadrupole and dipole radiations is proportional to the squared ratio of the hydrodynamic velocity of the oscillating surface of a charged drop to the velocity of propagation of an electromagnetic signal in vacuum (velocity of light), which yields a ratio of 10-14 to 10-15.

  12. Personality disorders and treatment drop out in the homeless

    Directory of Open Access Journals (Sweden)

    Salavera C

    2013-03-01

    Full Text Available Carlos Salavera,1 José M Tricás,2 Orosia Lucha21Faculty of Education, University of Zaragoza, Zaragoza, Spain; 2Physiotherapy Research Unit, University of Zaragoza, Zaragoza, SpainAbstract: The homeless drop out of treatment relatively frequently. Also, prevalence rates of personality disorders are much higher in the homeless group than in the general population. We hypothesize that when both variables coexist – homelessness and personality disorders – the possibility of treatment drop out grows. The aim of this study was to analyze the hypotheses, that is, to study how the existence of personality disorders affects the evolution of and permanence in treatment. One sample of homeless people in a therapeutic community (N = 89 was studied. The structured clinical interview for the diagnostic and statistical manual of mental disorders (DSM-IV-TR was administered and participants were asked to complete the Millon Clinical Multiaxial Inventory-II (MCMI-II. Cluster B personality disorders (antisocial, borderline, and narcissistic avoided permanence in the treatment process while cluster C disorders, as dependent, favored adhesion to the treatment and improved the prognosis. Knowledge of these personality characteristics should be used to advocate for better services to support homeless people and prevent their dropping out before completing treatment.Keywords: MCMI-II, abandonment, personality disorder, homeless

  13. Pinning of a drop by a junction on an incline

    Science.gov (United States)

    De Coninck, Joël; Fernández Toledano, Juan Carlos; Dunlop, François; Huillet, Thierry

    2017-10-01

    The shape of a drop pinned on an inclined substrate is a long-standing problem where the complexity of real surfaces, with heterogeneities and hysteresis, makes it complicated to understand the mechanisms behind the phenomena. Here we consider the simple case of a drop pinned on an incline at the junction between a hydrophilic half plane (the top half) and a hydrophobic one (the bottom half). Relying on the equilibrium equations deriving from the balance of forces, we exhibit three scenarios depending on the way the contact line of the drop on the substrate either simply leans against the junction or overfills (partly or fully) into the hydrophobic side. We draw some conclusions on the geometry of the overlap and the stability of these tentative equilibrium states. In the corresponding retention force factor, we find that a major role is played by the wetted length of the junction line, in the spirit of Furmidge's observations. The predictions of the theory are compared with extensive molecular dynamics simulations.

  14. [Preservative-containing eye drops and adherence in ophthalmological practice].

    Science.gov (United States)

    Lanzl, I; Kaercher, T

    2012-11-01

    Chronic eye diseases, such as glaucoma or dry eye syndrome, require long-term drug application to the eyes. Good adherence is required to achieve the therapeutic goal and patient needs and requirements have to be taken into account. This distinguishes adherence to drug therapy from the former compliance which implies only following medical instructions. Adherence is influenced by socioeconomic, health system-related, disease-related, treatment-related and patient-related factors. It can be measured by tedious procedures, such as electronic monitoring, self-assessment, drop counting and laboratory findings of systemic drug levels. Non-adherence is a growing medical problem worldwide. An increase in adherence means an increased degree of therapeutic safety for the patient and long-term cost savings for the individual as well as society. Non-adherence in chronic diseases, such as glaucoma and dry eye syndrome is increased by eye drops that cause side effects. Often these side effects are caused by agents such as the preservative benzalkonium chloride. To achieve a good adherence preservative-free eye drops are advised.

  15. Treatment of allergic conjunctivitis with olopatadine hydrochloride eye drops

    Directory of Open Access Journals (Sweden)

    Eiichi Uchio

    2008-10-01

    Full Text Available Eiichi UchioDepartment of Ophthalmology, Fukuoka University School of Medicine, Fukuoka, JapanAbstract: Olopatadine hydrochloride exerts a wide range of pharmacological actions such as histamine H1 receptor antagonist action, chemical mediator suppressive action, and eosinophil infiltration suppressive action. Olopatadine hydrochloride 0.1% ophthalmic solution (Patanol® was introduced to the market in Japan in October 2006. In a conjunctival allergen challenge (CAC test, olopatadine hydrochloride 0.1% ophthalmic solution significantly suppressed ocular itching and hyperemia compared with levocabastine hydrochloride 0.05% ophthalmic solution, and the number of patients who complained of ocular discomfort was lower in the olopatadine group than in the levocabastine group. Conjunctival cell membrane disruption was observed in vitro in the ketotifen fumarate group, epinastine hydrochloride group, and azelastine hydrochloride group, but not in the olopatadine hydrochloride 0.1% ophthalmic solution group, which may potentially explain the lower discomfort felt by patients on instillation. Many other studies in humans have revealed the superiority of olopatadine 0.1% hydrochloride eye drops to several other anti-allergic eye drops. Overseas, olopatadine hydrochloride 0.2% ophthalmic solution for a once-daily regimen has been marketed under the brand name of Pataday®. It is expected that olopatadine hydrochloride ophthalmic solutions may be used in patients with a more severe spectrum of allergic conjunctival diseases, such as vernal keratoconjunctivitis or atopic keratoconjunctivitis, in the near future.Keywords: olopatadine, eye drop, allergic conjunctivitis, anti-histaminergic

  16. Effect of drop jump technique on the reactive strength index.

    Science.gov (United States)

    Struzik, Artur; Juras, Grzegorz; Pietraszewski, Bogdan; Rokita, Andrzej

    2016-09-01

    The basic drill of plyometric training aimed at improving lower limb power and jump height is a drop jump. This exercise can be performed using different techniques, which substantially affects jump variables. Therefore, the aim of this study was to compare the values of the reactive strength index (RSI) for countermovement drop jumps (CDJs) and bounce drop jumps (BDJs). The study was carried out in a group of 8 male youth basketball players. The tests were conducted using the AMTI BP600900 force plate to measure ground reaction forces and the Noraxon MyoMotion system to record kinematic data. Each player performed two CDJs and two BDJs from the height of 15, 30, 45 and 60 cm. The RSI was calculated as a ratio of jump height and contact time. Moreover, the RSI was determined for the amortization and take-off phases separately. Significant differences (p jumps from 30, 45 and 60 cm. Differences in RSI values for jumps from 15 cm were not significant. Furthermore, CDJ height values were significantly higher (p jump technique that is commonly performed by basketball players.

  17. The Pain Response to Mydriatic Eye Drops in Preterm Infants

    Science.gov (United States)

    Cohen, Amy M.; Cook, Noah; Harris, Mary Catherine; Ying, Gui-shuang; Binenbaum, Gil

    2013-01-01

    Objective Evaluate physiologic and behavioral pain responses of premature infants following instillation of mydriatic eye drops for ROP examinations. While burning and stinging occurs in older patients, the infant pain response is not well characterized. Study Design Vital sign and video monitor recorded infant responses before, during, and after mydriatic (tropicamide 1%, phenylephrine 2.5%) administration upon first ROP exam. Two masked observers graded Premature Infant Pain Profile (PIPP) scores immediately prior and following eye drop administration. Scores 12 severe. Results Twenty infants had mean pre-mydriatic PIPP score 3.6 (SD 1.6), mean post-mydriatic score 5.7 (SD 3.4), mean change 2.1 (SD 3.4)(p=0.01). One (5%) had pre-mydriatic PIPP score ≥7, seven (35%) post scores ≥7 (p=0.07) with one >12. Conclusions Mydriatic drops cause a clinically significant pain response in one third of infants. Non-pharmacologic supportive measures are recommended for all infants until predictive factors are defined. PMID:23238569

  18. Impact and Penetration of Nanoparticle Suspension Drops into Porous Membranes

    Science.gov (United States)

    Sahu, Rakesh; Yarin, Alexander; Pourdeyhimi, Behnam

    2014-03-01

    The impacts and dynamic penetration of drops with suspended nanoparticles into porous membranes are studied experimentally and theoretically. This type of penetration is radically different from the wettability-driven imbibition. Two types of membranes are used in the experiments: (i) glass fiber filter membrane (wettable) and (ii) PTFE depth filter (non-wettable). The nanoparticle entrainment and deposition inside the membrane bulk is used to mostly visualize the ultimate penetration fronts of the carrier fluid by observing the cut cross-sections of the filter membranes, albeit also provides an insight into potentially new applications like circuit printing on nonwovens. The experimental results demonstrate that during the dynamic focusing responsible for water penetration into micro- and nanopores, water can penetrate into a non-wettable porous medium (PTFE). Water also penetrates by the same focusing mechanism into the wettable glass fiber membrane, where it additionally spreads on a much longer time scale due to the wettability-driven flow. A theory explaining dynamic penetration of liquid into porous medium after drop impact is proposed. It is used to explain and predict water penetration into the non-wettable media after drop impact, and the results are compared with the experimental data. The work was supported by the Nonwovens Cooperative Research Center (NCRC).

  19. Personality disorders and treatment drop out in the homeless.

    Science.gov (United States)

    Salavera, Carlos; Tricás, José M; Lucha, Orosia

    2013-01-01

    The homeless drop out of treatment relatively frequently. Also, prevalence rates of personality disorders are much higher in the homeless group than in the general population. We hypothesize that when both variables coexist - homelessness and personality disorders - the possibility of treatment drop out grows. The aim of this study was to analyze the hypotheses, that is, to study how the existence of personality disorders affects the evolution of and permanence in treatment. One sample of homeless people in a therapeutic community (N = 89) was studied. The structured clinical interview for the diagnostic and statistical manual of mental disorders (DSM-IV-TR) was administered and participants were asked to complete the Millon Clinical Multiaxial Inventory-II (MCMI-II). Cluster B personality disorders (antisocial, borderline, and narcissistic) avoided permanence in the treatment process while cluster C disorders, as dependent, favored adhesion to the treatment and improved the prognosis. Knowledge of these personality characteristics should be used to advocate for better services to support homeless people and prevent their dropping out before completing treatment.

  20. Regulatory Snapshots: integrative mining of regulatory modules from expression time series and regulatory networks.

    Directory of Open Access Journals (Sweden)

    Joana P Gonçalves

    Full Text Available Explaining regulatory mechanisms is crucial to understand complex cellular responses leading to system perturbations. Some strategies reverse engineer regulatory interactions from experimental data, while others identify functional regulatory units (modules under the assumption that biological systems yield a modular organization. Most modular studies focus on network structure and static properties, ignoring that gene regulation is largely driven by stimulus-response behavior. Expression time series are key to gain insight into dynamics, but have been insufficiently explored by current methods, which often (1 apply generic algorithms unsuited for expression analysis over time, due to inability to maintain the chronology of events or incorporate time dependency; (2 ignore local patterns, abundant in most interesting cases of transcriptional activity; (3 neglect physical binding or lack automatic association of regulators, focusing mainly on expression patterns; or (4 limit the discovery to a predefined number of modules. We propose Regulatory Snapshots, an integrative mining approach to identify regulatory modules over time by combining transcriptional control with response, while overcoming the above challenges. Temporal biclustering is first used to reveal transcriptional modules composed of genes showing coherent expression profiles over time. Personalized ranking is then applied to prioritize prominent regulators targeting the modules at each time point using a network of documented regulatory associations and the expression data. Custom graphics are finally depicted to expose the regulatory activity in a module at consecutive time points (snapshots. Regulatory Snapshots successfully unraveled modules underlying yeast response to heat shock and human epithelial-to-mesenchymal transition, based on regulations documented in the YEASTRACT and JASPAR databases, respectively, and available expression data. Regulatory players involved in

  1. Therapeutic Effect of 0.1% Tacrolimus Eye Drops in the Tarsal Form of Vernal Keratoconjunctivitis.

    Science.gov (United States)

    Wan, Qi; Tang, Jing; Han, Yu; Wang, Dan; Ye, Hongquan

    2017-08-12

    The purpose of this study was to evaluate the efficacy and safety of 0.1% tacrolimus eye drops in the tarsal form of vernal keratoconjunctivitis (VKC) and to survey the changes of dendritic cells at the palpebral conjunctiva in patients with VKC by in vivo confocal microscopy. A total of 17 patients (34 eyes) with the tarsal form of VKC were enrolled in this prospective, nonrandomized case series. They were treated with 0.1% tacrolimus eye drops twice daily after discontinuation of all other topical medications. Subjective ocular symptoms and objective ocular signs were scored on a 4-point scale by one ophthalmologist and the characteristics of the dendritic cells in each right eye at the palpebral conjunctiva were evaluated by in vivo confocal microscopy before treatment and at the 1st, 2th, 4th, and 8th weeks after treatment. After 1 week of treatment with 0.1% tacrolimus eye drops, the score for each symptom in all patients showed a significant (p < 0.001) improvement, and 13 patients (76%) experienced dramatic relief of symptoms. In addition, there was a significantly (p < 0.001) decreased clinical sign score (except for giant papillae) after 4 weeks, and a significant (p < 0.001) improvement in the score of giant papillae after 8 weeks of treatment. The characteristics of dendritic cells (including cell count, total area, average size, perimeter, and diameter) showed a significant (p < 0.05) decrease after 2 weeks of treatment. During the follow-up, no other topical medications were required and no significant changes in visual acuity were documented. No cataracts or elevation of intraocular pressures were detected. Only 5 patients (29%) had a tingling or burning sensation or discomfort. Tacrolimus 0.1% eye drops are an effective and safe treatment for the tarsal form of VKC, and can rapidly inhibit the activity of dendritic cells, improve symptoms, reduce papillary hyperplasia, and reverse damage at the palpebral conjunctiva. The side effects could affect the

  2. Anti-regulatory T cells

    DEFF Research Database (Denmark)

    Andersen, Mads Hald

    2017-01-01

    Our initial understanding of immune-regulatory cells was based on the discovery of suppressor cells that assure peripheral T-cell tolerance and promote immune homeostasis. Research has particularly focused on the importance of regulatory T cells (Tregs) for immune modulation, e.g. directing host...... responses to tumours or inhibiting autoimmunity development. However, recent studies report the discovery of self-reactive pro-inflammatory T cells—termed anti-regulatory T cells (anti-Tregs)—that target immune-suppressive cells. Thus, regulatory cells can now be defined as both cells that suppress immune......-reactive T cells that recognize such targets may be activated due to the strong activation signal given by their cognate targets. The current review describes the existing knowledge regarding these self-reactive anti-Tregs, providing examples of antigen-specific anti-Tregs and discussing their possible roles...

  3. Skeletal muscle fatigue in long-distance runners, sprinters and untrained men after repeated drop jumps performed at maximal intensity.

    Science.gov (United States)

    Skurvydas, A; Dudoniene, V; Kalvenas, A; Zuoza, A

    2002-02-01

    One hundred drop jumps were performed at maximal intensity every 20 s in 12 untrained subjects (UT), 9 sprinters (S) and 10 long-distance runners (LDR). Muscle contraction force (P20, P50) induced by percutaneous electrical stimulation (20 Hz and 50 Hz, respectively) as well as maximal voluntary contraction force and the height of vertical jumps performed in different ways decreased (Psprinters during counter-movement jump and drop jump at 90 degrees decreased to a smaller extent compared to jumps performed by LDR and UT. Muscle pain did not differ between UT, S and LDR at 24 h post exercise. The present data indicate that endurance training status as well as prevalence of muscle fibres of the slow type does not decrease muscle resistance to LFF nor accelerate the recovery of muscle contraction force following maximal, intermittent stretch-shortening cycle exercise.

  4. Impact of mydriatic eye drops on neonatal cerebral blood flow

    Directory of Open Access Journals (Sweden)

    Atef Alshafei

    2017-11-01

    Full Text Available Retinopathy of prematurity (ROP screening is a common routine procedure carried out on preterm infants in neonatal intensive care units (NICUs. Mydriatic eye drops containing phenylephrine hydrochloride 2.5% (a sympathomimetic agent and tropicamide 0.5% (a cycloplegic medication are readily absorbed from the conjunctiva and produce systemic responses in various organs. To our knowledge, no studies have investigated the direct effects of these medications on cerebral blood flow velocities (CBFVs in preterm infants. To evaluate the systemic effects of locally instilled mydriatic eye drops (phenylephrine hydrochloride 2.5% and tropicamide 0.5% used for ROP screening, on cerebral blood flow velocity in preterm infants, a prospective observational study was conducted among preterm infants with gestational age (GA < 31 weeks admitted to the NICU at Dubai Hospital between February 20, 2017 and June 20, 2017. The infants (at a post-menstrual age of 31-34 weeks underwent duplex ultrasound evaluation of CBFV before and after mydriatic eye drops administration.Pulsed-wave Doppler ultrasound studies were performed 1 h before and 1 h after eye mydriasis. We measured peak systolic velocity (PSV and end diastolic velocity (EDV for both the anterior cerebral artery (ACA and middle cerebral artery (MCA and calculated the resistive index (RI, defined as PSV – EDV/PSV. Mean arterial blood pressure (MAP, heart rate, oxygen saturation and pain score were assessed before and 1 h after ROP examination.A paired t-test and McNemar’s test were used to assess the statistical significance of the difference between pairs of means and the qualitative variables measured twice for the same study group.Among the 42 eligible preterm infants, the mean (SD GA was 27 (2.68 weeks (range, 24-31 weeks. The mean (SD RI of ACA before and 1 h after eye drops administration was 0.84 (0.06 and 0.83 (0.07 respectively (p = 0.453. The mean (SD RIs of MCA before and then 1 h after

  5. Lymphocyte Activation - Regulatory Substances.

    Science.gov (United States)

    1985-12-10

    D~XPP (Yeat.MonthDay) S.PAGE COUNT > KJnaJ FROM Oil__ TO 9/85 SWJSL 16. SUPPLEMENTARY NOTATION None 1: i. COSATI CODES 1S. SUBJECT TERMS ( Continue an...microfuge centrifugation in the presence of 25mM EDTA and protease tnhibitors such as PMSF, bisulftte and anttpain. EOTA and the protease inhibitors are not...product. These observations strengthen our conviction that CS DNA is a nucleoprotein structure distinct from nucleosomes. r.T, CqA &I D 1C TAB 0 7 ivr

  6. Regulatory facility guide for Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S.S.; Bock, R.E.; Francis, M.W.; Gove, R.M.; Johnson, P.E.; Kovac, F.M.; Mynatt, J.O. [Oak Ridge National Lab., TN (United States); Rymer, A.C. [Transportation Consulting Services, Knoxville, TN (United States)

    1994-02-28

    The Regulatory Facility Guide (RFG) has been developed for the DOE and contractor facilities located in the state of Ohio. It provides detailed compilations of international, federal, and state transportation-related regulations applicable to shipments originating at destined to Ohio facilities. This RFG was developed as an additional resource tool for use both by traffic managers who must ensure that transportation operations are in full compliance with all applicable regulatory requirements and by oversight personnel who must verify compliance activities.

  7. Rhadinoviral interferon regulatory factor homologues.

    Science.gov (United States)

    Koch, Sandra; Schulz, Thomas F

    2017-07-26

    Kaposi's sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8 (HHV8) is a gammaherpesvirus and the etiological agent of Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman disease. The KSHV genome contains genes for a unique group of proteins with homology to cellular interferon regulatory factors, termed viral interferon regulatory factors (vIRFs). This review will give an overview over the oncogenic, antiapoptotic and immunomodulatory characteristics of KSHV and related vIRFs.

  8. Electronic Commerce Removing Regulatory Impediments

    Science.gov (United States)

    1992-05-01

    AD-A252 691 ELECTRONIC COMMERCE Removing Regulatory Impediments ~DuiG A% ELECTE I JUL1 8 1992 0 C D Daniel J. Drake John A. Ciucci ... - ""N ST AT KE...Management Institute 6400 Goldsboro Road Bethesda, Maryland 20817-5886 92 LMI Executive Summary ELECTRONIC COMMERCE : REMOVING REGULATORY IMPEDIMENTS... Electronic Commerce techniques, such as electronic mail and electronic data interchange (EDI), enable Government agencies to conduct business without the

  9. ESA Parabolic Flight, Drop Tower and Centrifuge Opportunities for University Students

    Science.gov (United States)

    Callens, Natacha; Ventura-Traveset, Javier; Zornoza Garcia-Andrade, Eduardo; Gomez-Calero, Carlos; van Loon, Jack J. W. A.; Pletser, Vladimir; Kufner, Ewald; Krause, Jutta; Lindner, Robert; Gai, Frederic; Eigenbrod, Christian

    The European Space Agency (ESA) Education Office was established in 1998 with the purpose of motivating young people to study science, engineering and technology subjects and to ensure a qualified workforce for ESA and the European space sector in the future. To this end the ESA Education Office is supporting several hands-on activities including small student satellites and student experiments on sounding rockets, high altitude balloons as well as microgravity and hypergravity platforms. This paper is intended to introduce three new ESA Education Office hands-on activities called "Fly Your Thesis!", "Drop Your Thesis!" and "Spin Your Thesis!". These activities give re-spectively access to aircraft parabolic flight, drop tower and centrifuge campaigns to European students. These educational programmes offer university students the unique opportunity to design, build, and eventually perform, in microgravity or hypergravity, a scientific or techno-logical experiment which is linked to their syllabus. During the "Fly Your Thesis!" campaigns, the students accompany their experiments onboard the A300 Zero-G aircraft, operated by the company Novespace, based in Bordeaux, France, for a series of three flights of 30 parabolas each, with each parabola providing about 20s of microgravity [1]. "Drop Your Thesis!" campaigns are held in the ZARM Drop Tower, in Bremen, Germany. The installation delivers 4.74s of microgravity in dropping mode and 9.3s in the catapulting mode [2]. Research topics such as fluid physics, fundamental physics, combustion, biology, material sciences, heat transfer, astrophysics, chemistry or biochemistry can greatly benefit from using microgravity platforms. "Spin Your Thesis!" campaigns take place in the Large Diameter Centrifuge (LDC) facility, at ESTEC, Noordwijk, in the Netherlands. This facility offers an acceleration from 1 to 20 times Earth's gravity [3]. The use of hypergravity allows completing the scientific picture of how gravity has an

  10. Automatic control of a drop-foot stimulator based on angle measurement using bioimpedance.

    Science.gov (United States)

    Nahrstaedt, Holger; Schauer, Thomas; Shalaby, Raafat; Hesse, Stefan; Raisch, Jörg

    2008-08-01

    The topic of this contribution is iterative learning control of a drop-foot stimulator in which a predefined angle profile during the swing phase is realized. Ineffective dorsiflexion is compensated by feedback-controlled stimulation of the muscle tibialis anterior. The ankle joint measurement is based on changes in the bioimpedance (BI) caused by leg movements. A customized four-channel BI measurement system was developed. The suggested control approach and the new measurement method for the joint angle were successfully tested in preliminary experiments with a neurologically intact subject. Reference angle measurements were taken with a marker-based optical system. An almost linear relation between joint angle and BI was found for the angle range applicable during gait. The desired angle trajectory was closely tracked by the iterative learning controller after three gait cycles. The final root mean square tracking error was below 5 degrees.

  11. Functional knee brace use effect on peak vertical ground reaction forces during drop jump landing.

    Science.gov (United States)

    Rishiraj, Neetu; Taunton, Jack E; Lloyd-Smith, Robert; Regan, William; Niven, Brian; Woollard, Robert

    2012-12-01

    The aim of the study was to investigate the landing strategies used by non-injured athletes while wearing functional knee braces (FKB, BR condition) during a drop jump task compared with non-injured, non-braced (NBR condition) subjects and also to ascertain whether accommodation to a FKB was possible by non-injured BR subjects. Twenty-three healthy male provincial and national basketball and field hockey athletes (age, 19.4 ± 3.0 years) were tested. Each subject was provided with a custom-fitted FKB. Five NBR testing sessions were performed over 3 days followed by five BR testing sessions also over 3 days, for a total of 17.5 h of testing per condition. Each subject performed eight trials of the drop jump task during each testing session per condition. Single-leg peak vertical ground reaction forces (PVGRF) and the time to PVGRF were recorded for each NBR and BR trail. The BR group mean PVGRF at landing was significantly lower (1,628 ± 405 N, 2.1 ± 0.5 BW versus 1,715 ± 403 N, 2.2 ± 0.5 BW, F (1,22) = 6.83, P = 0.01) compared with NBR subjects, respectively. The group mean time to PVGRF was not statistically longer during the BR condition (F (1,22) = 0.967, P = 0.3). Further, an accommodation trend was noted as percent performance difference decreased with continued FKB use. The significantly lower group mean PVGRF while using a FKB could keep traumatic forces from reaching the ACL until the active neuromuscular restraints are activated to provide protection to the knee joint ligaments. Also, accommodation to FKB is possible after approximately 14.0 h of brace use. The results of this paper will assist clinicians in providing information to their patients regarding a FKB ability to offer protection to an ACL-deficient knee or to address concerns about early muscle fatigue, energy expenditure, heart rate, and decrease in performance level. Prospective study, Level I.

  12. A critical look at South Africa's Green Drop Programme | Ntombela ...

    African Journals Online (AJOL)

    In this paper we briefly reflect on the different legislation and types of regulatory mechanisms that South Africa's Department of Water and Sanitation (DWS) has in place to try to improve the performance and compliance of water services authorities (WSAs) in the controversial wastewater services sector. In particular, we ...

  13. STUDY ON SOFTENING AND DROPPING PROPERTIES OF METALIZED BURDEN INSIDE BLAST FURNACE

    Directory of Open Access Journals (Sweden)

    Bi-yang Tuo

    2014-12-01

    Full Text Available The inferences of burden metallization rate on softening-melting dropping properties were investigated through softening-melting dropping test of three kinds of metalized burden pressure drop. The results indicated that the softeningmelting temperature interval of pre-reduction mixed burden is bigger than primeval mixed burden, the melting interval narrow with the rise of metallization rate of ferric burden as well as dropping temperature interval. The average pressure drop, maximum pressure drop and softening-melting dropping properties eigenvalue decrease with the rise of metallization rate of ferric burden. Besides, the dropping temperature of burden reduces with the rise of carbon content of molten iron. The combination high metalized burden and higher carbon content of molten iron is benefit to decreasing thickness of cohesive zone and improve permeability of cohesive zone.

  14. Oblique impacts of water drops onto hydrophobic and superhydrophobic surfaces: outcomes, timing, and rebound maps

    Science.gov (United States)

    Antonini, C.; Villa, F.; Marengo, M.

    2014-04-01

    This paper presents an experimental study on water drop oblique impacts onto hydrophobic and superhydrophobic tilted surfaces, with the objective of understanding drop impact dynamics and the conditions for drop rebound on low wetting surfaces. Drop impact experiments were performed with millimetric water drops with Weber numbers in the range 25 definition of six different impact regimes: deposition, rivulet, sliding, rolling, partial rebound, and rebound. For superhydrophobic surfaces, surface tilting generally enhanced drop rebound and shedding from the surface, either by reducing drop rebound time up to 40 % or by allowing drop rebound even when impalement occurred in the vicinity of the impact region. On hydrophobic surfaces, rebound was never observed for tilt angles higher than 45°.

  15. Policy and Regulatory Challenges in the Tourism Collaborative Economy

    DEFF Research Database (Denmark)

    Dredge, Dianne

    2017-01-01

    The choice of policy approach and regulatory framework in dealing with the collaborative economy rests on two fundamental factors—that government decisions should be based on good sound knowledge and that this knowledge should be above politics. In the newly emerging and rapidly growing...... collaborative economy, these conditions are difficult to meet. The dynamic restructuring of power relations, new stakeholders and information asymmetries can obscure what is really going on. Some authors offer valuable meso-level explorations of policy and regulatory issues in different sub...... and circulate in policy discussions about the collaborative economy at a macro-level. The rendering of the socio-political landscape as complex, dynamic and value-laden dictates that policy approaches and regulatory solutions are subjective and influenced by prevailing ideology, available knowledge and the path...

  16. 76 FR 40200 - Semiannual Regulatory Flexibility Agenda

    Science.gov (United States)

    2011-07-07

    ... Semiannual Regulatory Flexibility Agenda AGENCY: Board of Governors of the Federal Reserve System. ACTION: Semiannual regulatory agenda. SUMMARY: The Board is issuing this agenda under the Regulatory Flexibility Act... rules the Board has selected for review under section 610(c) of the Regulatory Flexibility Act, and...

  17. Effect of recombinant human epidermal growth factor eye drops and deproteinized calf blood extract eye drops on corneal edema after phacoemulsification

    OpenAIRE

    Jia Wang

    2017-01-01

    AIM:To compare the effect of recombinant human epidermal growth factor eye drops and deproteinized calf blood extract eye drops on corneal edema after phacoemulsification. METHODS:Totally 72 cases(72 eyes)of patients undergoing phacoemulsification were selected and divided into the observation group and the control group by random number table method. After surgery, the observation group were treated with deproteinized calf blood extract eye drops while the control group were treated with rec...

  18. Efficacy of atropine and anisodamine eye drops for adolescent pseudomyopia

    Directory of Open Access Journals (Sweden)

    Hui-Jie Wang

    2017-03-01

    Full Text Available AIM:To investigate the effect and local influence of atropine and anisodamine eye drops on adolescent pseudomyopia. METHODS:Totally 110 cases of juvenile pseudomyopia were randomly divided into two groups, the control group was given 10g/L atropine sulfate eye gel, and the observation group was treated with 5g/L raceanisodamine eye drops. The efficacy of two methods, the changes of axial length and intraocular pressure before and after treatment, and the incidence of adverse reactions were compared. RESULTS: There was no significant difference in cure rate between the two groups(χ2=0.533, P=0.465, but the effective rate of observation group was significantly better than the control group(χ2=3.907, P=0.048. Compared with the same group before treatment, the length of the axial length of the two groups increased in different degrees,and the increase value of the observation group was significantly higher than that of the control group, the difference was statistically significant(PP>0.05. The intraocular pressure of the two groups was significantly lower than that of the same group before treatment, and the difference between the two groups after treatments was not statistically significant(P >0.05. The incidence of adverse reactions in the observation group was significantly lower than that in the control group(χ2=18.939, PCONCLUSION: Anisodamine eye drops in the treatment of juvenile pseudomyopia has obvious curative effect, its efficacy and safety are better than atropine eye gel.

  19. Drop Tower Experiments concerning Fluid Management under Microgravity

    Science.gov (United States)

    Gaulke, Diana; Dreyer, Michael

    2012-07-01

    Transport and positioning of liquid under microgravity is done utilizing capillary forces. Therefore, capillary transport processes have to be understood for a wide variety of space applications, ranging from propellant management in tanks of space transportation systems to eating and drinking devices for astronauts. There are two types of liquid transportation in microgravity using capillary forces. First, the driven liquid flow in open channels where the capillary forces at free surfaces ensure a gas and vapor free flow. Here it is important to know the limiting flow rate through such an open channel before the free surface collapses and gas is sucked into the channel. A number of different experiments at the drop tower Bremen, on sounding rockets and at the ISS have been conducted to analyse this phenomenon within different geometries. As result a geometry dependent theory for calculating the maximum flow rate has been found. On the other hand liquid positioning and transportation requires the capillary pressure of curved surfaces to achieve a liquid flow to a desired area. Especially for space applications the weight of structure has to be taken into account for development. For example liquid positioning in tanks can be achieved via a complicated set of structure filling the whole tank resulting in heavy devices not reasonable in space applications. Astrium developed in cooperation with ZARM a propellant management device much smaller than the tank volume and ensuring a gas and vapour free supply of propellant to the propulsion system. In the drop tower Bremen a model of this device was tested concerning different microgravity scenarios. To further decrease weight and ensure functionality within different scenarios structure elements are designed as perforated geometries. Capillary transport between perforated plates has been analyzed concerning the influence of geometrical pattern of perforations. The conducted experiments at the drop tower Bremen show the

  20. Assessment of the quality of drop size measurements using a non-dedicated present weather sensor

    NARCIS (Netherlands)

    Leijnse, H.; Uijlenhoet, R.

    2009-01-01

    Drop size data from a present weather sensor have been compared to drop size data collected using a nearly co-located dedicated disdrometer. In a rainfall event that lasted more than 9 hours, with rainfall intensities up to 25 mm h-1 drop size distributions (DSDs) estimated by the two different

  1. The bifurcation diagram of drops in a sphere/plane geometry: influence of contact angle hysteresis

    NARCIS (Netherlands)

    de Ruiter, Riëlle; van Gorcum, M.; Semprebon, C.; Duits, Michael H.G.; Brinkmann, M.; Mugele, Friedrich Gunther

    2014-01-01

    We study liquid drops that are present in a generic geometry, namely the gap in between a sphere and a plane. For the ideal system without contact angle hysteresis, the drop position is solely dependent on the contact angle, drop volume, and sphere/ plane separation distance. Performing a geometric

  2. Determining fluid level in a translucent eye-drop bottle: transillumination by penlight.

    Science.gov (United States)

    Kayikcioğlu, O; Akkin, C; Ates, H

    We describe an easy way to determine eye-drop contents in translucent bottles. Transillumination of eye-drop bottles from behind or the bottom by using a penlight clearly defines the fluid levels. The described procedure may prevent disposal of eye-drop bottles containing useful amounts of medication and prevent Ophthalmologists and Patients unexpectedly coming across an empty bottle.

  3. Is Drop-Out from University Dependent on National Culture and Policy? The Case of Denmark

    Science.gov (United States)

    Troelsen, Rie; Laursen, Per F.

    2014-01-01

    National cultures are known to influence educational institutions and practices in many ways. It therefore seems reasonable to assume that drop-out from university is also influenced by differences in national cultures. In this article, we compare drop-out from Danish universities with drop-out from European universities. Based on Danish national…

  4. Drop shape analysis for determination of dynamic contact angles by double sided elliptical fitting method

    DEFF Research Database (Denmark)

    Andersen, Nis Korsgaard; Taboryski, Rafael J.

    2017-01-01

    fitted to a drop profile derived from the Young-Laplace equation. When measuring the wetting behaviour by tilting experiments this is not possible since it involves moving drops that are not in equilibrium. Here we present a fitting technique capable of determining the contact angle of asymmetric drops...

  5. 33 CFR 401.49 - Dropping anchor or tying to canal bank.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Dropping anchor or tying to canal bank. 401.49 Section 401.49 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT... Dropping anchor or tying to canal bank. Except in an emergency, no vessel shall drop anchor in any canal or...

  6. Tracking Drop-out Students in Palestinian Refugee Camps in Lebanon

    Science.gov (United States)

    Al-Hroub, Anies

    2015-01-01

    This research paper examines the perceptions of students on the school drop-out problem in Palestinian refugee camps in Lebanon regarding (a) the social and economic causes associated with the phenomenon of school drop-out; (b) the educational policies and practices used in UNRWA schools and their relationship to student drop-out; and (c) the role…

  7. A novel Caulimovirus associated with a complete fruit drop symptom in ‘Bluecrop’ blueberry

    Science.gov (United States)

    Here we describe the nucleotide sequence and genome organization of a novel virus in the family Caulimoviridae from ‘Bluecrop’ blueberry plants that exhibited fruit drop symptoms. The virus is tentatively named Blueberry fruit drop associated virus (BFDaV). Blueberry fruit drop disease (BFDD) was fi...

  8. Identification of regulatory modules in genome scale transcription regulatory networks.

    Science.gov (United States)

    Song, Qi; Grene, Ruth; Heath, Lenwood S; Li, Song

    2017-12-15

    In gene regulatory networks, transcription factors often function as co-regulators to synergistically induce or inhibit expression of their target genes. However, most existing module-finding algorithms can only identify densely connected genes but not co-regulators in regulatory networks. We have developed a new computational method, CoReg, to identify transcription co-regulators in large-scale regulatory networks. CoReg calculates gene similarities based on number of common neighbors of any two genes. Using simulated and real networks, we compared the performance of different similarity indices and existing module-finding algorithms and we found CoReg outperforms other published methods in identifying co-regulatory genes. We applied CoReg to a large-scale network of Arabidopsis with more than 2.8 million edges and we analyzed more than 2,300 published gene expression profiles to charaterize co-expression patterns of gene moduled identified by CoReg. We identified three types of modules in the Arabidopsis network: regulator modules, target modules and intermediate modules. Regulator modules include genes with more than 90% edges as out-going edges; Target modules include genes with more than 90% edges as incoming edges. Other modules are classified as intermediate modules. We found that genes in target modules tend to be highly co-expressed under abiotic stress conditions, suggesting this network struture is robust against perturbation. Our analysis shows that the CoReg is an accurate method in identifying co-regulatory genes in large-scale networks. We provide CoReg as an R package, which can be applied in finding co-regulators in any organisms with genome-scale regulatory network data.

  9. Adaptive simulations of drop/interface impact and rupture

    Science.gov (United States)

    Zheng, Xiaoming; Lowengrub, John; Longmire, Ellen; Cristini, Vittorio

    2002-11-01

    We present an algorithm for simulations of topology transitions (e.g., breakup and coalescence) in complex multiphase fluids. The algorithm is based on a finite element unstructured triangulated mesh, and on a diffuse-interface representation of the interfaces. During a simulation, the computational mesh is automatically adapted to describe accurately the complex morphology associated to the topology transitions and the narrow lubrication gaps between the interfaces. We apply this algorithm to study the impact and coalescence of viscous drops on solid and fluid-fluid interfaces. We compare our simulations to experimental results.

  10. Pressure Drop in Vertical Core-Annular Flow

    OpenAIRE

    Prada,José Walter Vanegas; Bannwart,Antonio Carlos

    2001-01-01

    An experimental apparatus for the study of core annular flows of heavy oil and water at room temperature has been set up and tested at laboratory scale. The test section consists of a 2.75 cm ID galvanized steel pipe. Tap water and a heavy oil (17.6 Pa.s; 963 kg/m³) were used. Pressure drop in a vertical upward test section was accurately measured for oil flow rates in the range 0.297 - 1.045 l/s and water flow rates ranging from 0.063 to 0.315 l/s. The oil-water input ratio was in the range ...

  11. Simple Model For Pressure Drop In Horizontal Core Annular Flow

    OpenAIRE

    Bannwart A.C.

    1999-01-01

    Based upon experimental data for heavy oil-water flow inside steel (26.7 mm ID) and cemented (23.9 mm ID) horizontal tubes, a very simple model for pressure drop in the core annular flow pattern was developed. The experiments were run at room temperature and the fluids used were a fuel oil (μ = 2.7 Pa.s, ρ = 989 kg/m3) and tap water, both drawn from a separator tank. First, it is shown that for both tubes the so-called 'perfect core annular flow' approach (shortly PCAF) poorly correlates the ...

  12. Analysis of Random Drop for Gateway Congestion Control

    Science.gov (United States)

    1989-11-01

    tcp- 1 2b PAPAYA PANANA berE. TUTAH- G W utah-Link 177 12a User Za U= lb ep-12& trp-2- WP-1b U PPRnk2 &fficns IQYd GUAVA sw-link SACmGW TJ. 2b Uzer 7b...yield more efficient overall behavior. The chapter concludes with a comparison of the performance of Random Drop to that of No Gateway Policy congestion...share of the available buffers, any of its packets that leaves the bottleneck will be shortly replaced by a new data packet. On the other hand, the second

  13. Mechanisms of drop formation in air-supported spray boxes

    Energy Technology Data Exchange (ETDEWEB)

    Wittig, S.; Sattelmayer, T.; Aigner, M.; Sakbani, K.

    1985-10-01

    In the course of further development of gas turbine combustion chambers, the fuel spraying was comprehensively investigated. The air-supported sprayer with liquid film in the nozzle (air blast nozzle) enables a reduction of the emission of noxious matter and shows a favourable operational behaviour. The basic mechanisms were investigated with the help of models and their possible transfer checked with test nozzles. The influences of the physical properties of the fuel, of the geometry and the operational parameter on the film formation and disintegration as well as the produced drop spectrum could be clarified in detail. (orig.).

  14. Conditioning Analysis of Incomplete Cholesky Factorizations with Orthogonal Dropping

    Energy Technology Data Exchange (ETDEWEB)

    Napov, Artem [Free Univ. of Brussels (Belgium)

    2013-08-01

    The analysis of preconditioners based on incomplete Cholesky factorization in which the neglected (dropped) components are orthogonal to the approximations being kept is presented. General estimate for the condition number of the preconditioned system is given which only depends on the accuracy of individual approximations. The estimate is further improved if, for instance, only the newly computed rows of the factor are modified during each approximation step. In this latter case it is further shown to be sharp. The analysis is illustrated with some existing factorizations in the context of discretized elliptic partial differential equations.

  15. Estimating Subjective Probabilities

    DEFF Research Database (Denmark)

    Andersen, Steffen; Fountain, John; Harrison, Glenn W.

    Subjective probabilities play a central role in many economic decisions, and act as an immediate confound of inferences about behavior, unless controlled for. Several procedures to recover subjective probabilities have been proposed, but in order to recover the correct latent probability one must...

  16. Estimating Subjective Probabilities

    DEFF Research Database (Denmark)

    Andersen, Steffen; Fountain, John; Harrison, Glenn W.

    2014-01-01

    Subjective probabilities play a central role in many economic decisions and act as an immediate confound of inferences about behavior, unless controlled for. Several procedures to recover subjective probabilities have been proposed, but in order to recover the correct latent probability one must ...

  17. Subjective meaning: an introduction

    NARCIS (Netherlands)

    van Wijnbergen-Huitink, Janneke; van Wijbergen-Huitink, Janneke; Meier, Cécile

    This introductory chapter traces some of the considerations on the basis of which relativistic approaches to subjective meaning became en vogue. In doing so, the chapter provides an overview of the relevant linguistic and philosophical issues when developing a treatment of subjectivity. In addition,

  18. Subjective safety in traffic.

    NARCIS (Netherlands)

    2012-01-01

    The term ‘subjective safety in traffic’ refers to people feeling unsafe in traffic or, more generally, to anxiety regarding being unsafe in traffic for oneself and/or others. Subjective safety in traffic can lead to road users limiting their mobility and social activities, which is one of the

  19. Subjective poverty line definitions

    NARCIS (Netherlands)

    J. Flik; B.M.S. van Praag (Bernard)

    1991-01-01

    textabstractIn this paper we will deal with definitions of subjective poverty lines. To measure a poverty threshold value in terms of household income, which separates the poor from the non-poor, we take into account the opinions of all people in society. Three subjective methods will be discussed

  20. Regulatory physiology discipline science plan

    Science.gov (United States)

    1991-01-01

    The focus of the Regulatory Physiology discipline of the Space Physiology and Countermeasures Program is twofold. First, to determine and study how microgravity and associated factors of space flight affect the regulatory mechanisms by which humans adapt and achieve homeostasis and thereby regulate their ability to respond to internal and external signals; and, second, to study selected physiological systems that have been demonstrated to be influenced by gravity. The Regulatory Physiology discipline, as defined here, is composed of seven subdisciplines: (1) Circadian Rhythms, (2) Endocrinology, (3) Fluid and Electrolyte Regulation, (4) Hematology, (5) Immunology, (6) Metabolism and Nutrition, and (7) Temperature Regulation. The purpose of this Discipline Science Plan is to provide a conceptual strategy for NASA's Life Sciences Division research and development activities in the area of regulatory physiology. It covers the research areas critical to NASA's programmatic requirements for the Extended-Duration Orbiter, Space Station Freedom, and exploration mission science activities. These science activities include ground-based and flight; basic, applied, and operational; and animal and human research and development. This document summarizes the current status of the program, outlines available knowledge, establishes goals and objectives, identifies science priorities, and defines critical questions in regulatory physiology. It contains a general plan that will be used by both NASA Headquarters Program Offices and the field centers to review and plan basic, applied, and operational intramural and extramural research and development activities in this area.

  1. Anti-regulatory T cells.

    Science.gov (United States)

    Andersen, Mads Hald

    2017-04-01

    Our initial understanding of immune-regulatory cells was based on the discovery of suppressor cells that assure peripheral T-cell tolerance and promote immune homeostasis. Research has particularly focused on the importance of regulatory T cells (Tregs) for immune modulation, e.g. directing host responses to tumours or inhibiting autoimmunity development. However, recent studies report the discovery of self-reactive pro-inflammatory T cells-termed anti-regulatory T cells (anti-Tregs)-that target immune-suppressive cells. Thus, regulatory cells can now be defined as both cells that suppress immune reactions as well as effector cells that counteract the effects of suppressor cells and support immune reactions. Self-reactive anti-Tregs have been described that specifically recognize human leukocyte antigen-restricted epitopes derived from proteins that are normally expressed by regulatory immune cells, including indoleamine 2,3-dioxygenase (IDO), tryptophan 2,6-dioxygenase (TDO), programmed death-ligand 1 (PD-L1), and forkhead box P3 (Foxp3). These proteins are highly expressed in professional antigen-presenting cells under various physiological conditions, such as inflammation and stress. Therefore, self-reactive T cells that recognize such targets may be activated due to the strong activation signal given by their cognate targets. The current review describes the existing knowledge regarding these self-reactive anti-Tregs, providing examples of antigen-specific anti-Tregs and discussing their possible roles in immune homeostasis and their potential future clinical applications.

  2. Regulatory focus and human values

    Directory of Open Access Journals (Sweden)

    Keller Johannes

    2017-01-01

    Full Text Available The present article connects two approaches to the study of human motivation and behavior: The Schwartz model of human values and Higgins’ regulatory focus theory. Considering a prominent model of human motivation - the Rubicon Model of Action Phases - reveals that although both approaches refer to goals and standards as crucial constructs, human values are specifically relevant concerning the so-called deliberation and evaluation phases whereas selfregulatory orientations are specifically relevant concerning the volitional phases (i.e., planning and action. It may be due to the selective focus on specific aspects of human motivation that up to date hardly any (empirical work has tried to connect human values and selfregulatory orientations. The reported studies assessed the relation between the endorsement of values proposed in the Schwartz model of human values and individual differences in the two self-regulatory orientations (promotion and prevention proposed in regulatory focus theory. Findings reveal that prevention-focused self-regulation is positively related to conservation values (security, conformity and negatively related to values reflecting openness to change (stimulation, self-direction. Moreover, promotion-focused self-regulation was positively related to self-enhancement values (power, achievement and negatively related to values reflecting self-transcendence (universalism, benevolence. In addition, the observed relations were found using different instruments to measure human values and self-regulatory orientations. In combination, the observed findings support the proposed two-dimensional structure of the value system as well as fundamental assumptions of regulatory focus theory.

  3. Regulatory Expectations for Safety Culture

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Su Jin; Oh, Jang Jin; Choi, Young Sung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-05-15

    The oversight of licensee's safety culture becomes an important issue that attracts great public and political concerns recently in Korea. Beginning from the intended violation of rules, a series of corruptions, documents forgery and disclosure of wrong-doings made the public think that the whole mindset of nuclear workers has been inadequate. Thus, they are demanding that safety culture shall be improved and that regulatory body shall play more roles and responsibilities for the improvements and oversight for them. This paper introduces, as an effort of regulatory side, recent changes in the role of regulators in safety culture, regulatory expectations on the desired status of licensee's safety culture, the pilot inspection program for safety culture and research activity for the development of oversight system. After the Fukushima accident in Japan 2011, many critics has searched for cultural factors that caused the unacceptable negligence pervaded in Japan nuclear society and the renewed emphasis has been placed on rebuilding safety culture by operators, regulators, and relevant institutions globally. Significant progress has been made in how to approach safety culture and led to a new perspective different from the existing normative assessment method both in operators and regulatory side. Regulatory expectations and oversight of them are based on such a new holistic concept for human, organizational and cultural elements to maintain and strengthen the integrity of defense in depth and consequently nuclear safety.

  4. Hybrid carbon-glass fiber/toughened epoxy thick composites subject to drop-weight and ballistic impacts

    Science.gov (United States)

    Sevkat, Ercan

    The goals of this study are to investigate the low velocity and ballistic impact response of thick-section hybrid fiber composites at room temperature. Plain-woven S2-Glass and IM7 Graphite fabrics are chosen as fiber materials reinforcing the SC-79 epoxy. Four different types of composites consisting of alternating layers of glass and graphite woven fabric sheets are considered. Tensile tests are conducted using 98 KN (22 kip) MTS testing machine equipped with environmental chamber. Low-velocity impact tests are conducted using an Instron-Dynatup 8250 impact test machine equipped with an environmental chamber. Ballistic impact tests are performed using helium pressured high-speed gas-gun. Tensile tests results were used to define the material behavior of the hybrid and non-hybrid composites in Finite Element modeling. The low velocity and ballistic impact tests showed that hybrid composites performance was somewhere between non-hybrid woven composites. Using woven glass fabrics as outer skin improved the impact performance of woven graphite composite. However hybrid composites are prone to delamination especially between dissimilar layers. The ballistic limit velocity V50 hybrid composites were higher that of woven graphite composite and lower than that of woven glass composite. Both destructive cross-sectional micrographs and nondestructive ultrasonic techniques are used to evaluate the damage created by impact. The Finite Element code LS-DYNA is chosen to perform numerical simulations of low velocity and ballistic impact on thick-section hybrid composites. The damage progression in these composites shows anisotropic nonlinearity. The material model to describe this behavior is not available in LS-DYNA material library. Initially, linear orthotropic material with damage (Chan-Chan Model) is employed to simulate some of the experimental results. Then, user-defined material subroutine is incorporated into LS-DYNA to simulate the nonlinear behavior. The experimentally obtained force-time histories, strain-time histories and damage patterns of impacted composites are compared with Finite element results. The results indicate that LS-DYNA could simulate the impact responses with sufficient accuracy once proper material models and boundary conditions are defined.

  5. Hybrid Carbon-Glass Fiber/Toughened Epoxy Thick Composite Joints Subject to Drop-Weight and Ballistic Impacts

    Science.gov (United States)

    2007-12-01

    NDT &E International 1996; 29(4): 225-36. 13. Lu X, Kim KY and Sachse W. In situ determination of elastic stiffness constants of thick composites...DP. The detection and measurement of impact damage in thick carbon fibre reinforced laminates by transient thermography. NDT &E International 1998...Composite Materials, ASTM STP 749. American Society for Testing and Materials, Philadelphia, 1981. 37. Lubin G (Ed). Handbook of Fibreglass and Advanced

  6. Accelerating Regulatory Progress in Multi-Institutional Research

    Science.gov (United States)

    Paolino, Andrea R.; Lauf, Sherry Lee; Pieper, Lisa E.; Rowe, Jared; Vargas, Ileana M.; Goff, Melissa A.; Daley, Matthew F.; Tuzzio, Leah; Steiner, John F.

    2014-01-01

    Purpose: Multi-institutional collaborations are necessary in order to create large and robust data sets that are needed to answer important comparative effectiveness research (CER) questions. Before scientific work can begin, a complex maze of administrative and regulatory requirements must be efficiently navigated to avoid project delays. Innovation: Staff from research, regulatory, and administrative teams involved in three HMO Research Network (HMORN) multi-institutional collaborations developed and employed novel approaches: to secure and maintain Institutional Review Board (IRB) approvals; to enable data sharing, and to expedite subawards for two data-only minimal risk studies. These novel approaches accelerated required processes and approvals while maintaining regulatory, human subjects, and institutional protections. Credibility: Outcomes from the processes described here are compared with processes outlined in the research and regulatory literature and with processes that have been used in previous multisite research collaborations. Conclusion and Discussion: Research, regulatory, and administrative staff are essential contributors to the success of multi-institutional collaborations. Their flexibility, creativity, and effective communication skills can lead to the development of efficient approaches to achieving the necessary oversight for these complex projects. Elements of these specific strategies can be adapted and used by other research networks. Other efforts in these areas should be evaluated and shared. The processes that help develop a “learning research system” play an important and complementary role in sustaining multi-institutional research collaborations. PMID:25848593

  7. Accelerating regulatory progress in multi-institutional research.

    Science.gov (United States)

    Paolino, Andrea R; Lauf, Sherry Lee; Pieper, Lisa E; Rowe, Jared; Vargas, Ileana M; Goff, Melissa A; Daley, Matthew F; Tuzzio, Leah; Steiner, John F

    2014-01-01

    Multi-institutional collaborations are necessary in order to create large and robust data sets that are needed to answer important comparative effectiveness research (CER) questions. Before scientific work can begin, a complex maze of administrative and regulatory requirements must be efficiently navigated to avoid project delays. Staff from research, regulatory, and administrative teams involved in three HMO Research Network (HMORN) multi-institutional collaborations developed and employed novel approaches: to secure and maintain Institutional Review Board (IRB) approvals; to enable data sharing, and to expedite subawards for two data-only minimal risk studies. These novel approaches accelerated required processes and approvals while maintaining regulatory, human subjects, and institutional protections. Outcomes from the processes described here are compared with processes outlined in the research and regulatory literature and with processes that have been used in previous multisite research collaborations. Research, regulatory, and administrative staff are essential contributors to the success of multi-institutional collaborations. Their flexibility, creativity, and effective communication skills can lead to the development of efficient approaches to achieving the necessary oversight for these complex projects. Elements of these specific strategies can be adapted and used by other research networks. Other efforts in these areas should be evaluated and shared. The processes that help develop a "learning research system" play an important and complementary role in sustaining multi-institutional research collaborations.

  8. Regulatory Volume Increase and Regulatory Volume Decrease Responses in HL-1 Atrial Myocytes

    Directory of Open Access Journals (Sweden)

    Veronica I. Cacace

    2014-05-01

    Full Text Available Background/Aims: we have investigated whether cultured cardiomyocytes of the cell line HL-1 have the ability to perform regulatory volume responses both in hypotonic and hypertonic conditions. Furthermore, we characterized those regulatory responses and studied the effects of bumetanide and DIDS in volume regulation of HL-1 cells. Methods: we used a light scattering system to measure the transient volume changes of HL-1 cells when subjected to osmotic challenge. Results: We found that HL-1 cells correct for their volume excess by undergoing regulatory volume decrease (RVD, and also respond to hypertonic stress with a regulatory volume increase (RVI. Rate of RVD was 0.08 ± 0.04 intensity/min, and rate of RVI was 0.09 ± 0.01 intensity/min. Volume recovery was 83.68 ± 5.73 % for RVD and 92.3 ± 2.3 % for RVI. Bumetanide 50 µM inhibited volume recovery, from 92.3 ± 2.3 % (control to 24.6 ± 8.8 % and reduced the rate of RVI from 0.070 ± 0.020 intensity/min (control to 0.010 ± 0.005 intensity/min. 50 µM DIDS reduced volume recovery to 42.93 ± 7.7 % and rate of RVI, to 0.03 ± 0.01 intensity/min. Conclusions: these results suggest that bumetanide- and DIDS-sensitive mechanisms are involved in the RVI of HL-1 cells, which points to the involvement of the Na+/K+/2Cl- cotransporter and Cl-/bicarbonate exchanger in RVI, respectively.

  9. Effects of a potential drop of a shipping cask, a waste container, and a bare fuel assembly during waste-handling operations; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.L.; Lee, J.; Lu, D.L.; Jardine, L.J. [Bechtel National, Inc., San Francisco, CA (United States)

    1991-12-01

    This study investigates the effects of potential drops of a typical shipping cask, waste container, and bare fuel assembly during waste-handling operations at the prospective Yucca Mountain Repository. The waste-handling process (one stage, no consolidation configuration) is examined to estimate the maximum loads imposed on typical casks and containers as they are handled by various pieces of equipment during waste-handling operations. Maximum potential drop heights for casks and containers are also evaluated for different operations. A nonlinear finite-element model is employed to represent a hybrid spent fuel container subject to drop heights of up to 30 ft onto a reinforced concrete floor. The impact stress, strain, and deformation are calculated, and compared to the failure criteria to estimate the limiting (maximum permissible) drop height for the waste container. A typical Westinghouse 17 {times} 17 PWR fuel assembly is analyzed by a simplified model to estimate the energy absorption by various parts of the fuel assembly during a 30 ft drop, and to determine the amount of kinetic energy in a fuel pin at impact. A nonlinear finite-element analysis of an individual fuel pin is also performed to estimate the amount of fuel pellet fracture due to impact. This work was completed on May 1990.

  10. Epinastine 0.05% ophthalmic solution in contact lens-wearing subjects with a history of allergic conjunctivitis.

    Science.gov (United States)

    Nichols, Kelly K; Morris, Scot; Gaddie, Ian B; Evans, David

    2009-01-01

    To assess the comfort and efficacy of epinastine 0.05% ophthalmic solution in contact lens wearers with a history of allergic conjunctivitis and contact lens intolerance during allergy season. One hundred forty-six subjects were enrolled in a multicenter, open-label study. Enrolled subjects instilled rewetting drops twice a day for a one-week run-in period, then were randomized to epinastine 0.05% twice a day plus rewetting drops as required (n = 75) or rewetting drops alone as required (minimum use twice a day) (n = 71). Subjects recorded the length of time that contact lens wear was comfortable, the total time of wear, ocular itch, overall comfort, and use of rewetting drops during the run-in period, at baseline, and on days 2 to 7 of the treatment period. Subjects averaged 34 years of age; 79% were female. No significant differences were shown at baseline between subjects treated with epinastine 0.05% twice a day plus rewetting drops and control subjects treated with rewetting drops alone. Averaged over the treatment period, epinastine provided significant increases in comfortable wearing time (1.33 +/- 2.89 vs. 0.43 +/- 2.28 hr, P=0.012) and total wearing time (0.35 +/- 1.87 vs. -0.32 +/- 1.81 hr, P=0.008) compared with controls. Epinastine users reported less frequent additional rewetting drop use on average by 0.56 uses per day, which was significantly different than controls (reduction of 0.06 uses per day; P=0.012). Epinastine provided significantly greater improvements from baseline in ocular itch and overall eye comfort compared with rewetting drops alone (Pcontact lens wearers.

  11. Drop coalescence and liquid flow in a single Plateau border

    Science.gov (United States)

    Cohen, Alexandre; Fraysse, Nathalie; Raufaste, Christophe

    2015-05-01

    We report a comprehensive study of the flow of liquid triggered by injecting a droplet into a liquid foam microchannel, also called a Plateau border. This drop-injected experiment reveals an intricate dynamics for the liquid redistribution, with two contrasting regimes observed, ruled either by inertia or viscosity. We devoted a previous study [A. Cohen et al., Phys. Rev. Lett. 112, 218303 (2014), 10.1103/PhysRevLett.112.218303] to the inertial imbibition regime, unexpected at such small length scales. Here we report other features of interest of the drop-injected experiment, related to the coalescence of the droplet with the liquid microchannel, to both the inertial and viscous regimes, and to the occurrence of liquid flow through the soap films as well as effects of the interfacial rheology. The transition between the two regimes is investigated and qualitatively accounted for. The relevance of our results to liquid foam drainage is tackled by considering the flow of liquid at the nodes of the network of interconnected microchannels. Extensions of our study to liquid foams are discussed.

  12. The shape of a drop between two rigid fibers

    Science.gov (United States)

    Protiere, Suzie; Duprat, Camille; Stone, Howard A.

    2012-11-01

    Wetting of fibrous media is observed in many engineered systems, e.g. filters, textiles, paper etc. and may also be found in Nature (e.g. hair or feathers). To understand the basic response of such material when interacting with a liquid we study the model system of a finite volume of liquid on two parallel rigid fibers. A liquid wetting the fibers can adopt two distinct equilibrium shapes: a compact hemispherical drop shape or a long liquid column of constant cross-section. These two morphologies depend on the inter-fiber distance, the liquid volume, the fiber radius and the liquid-fiber contact angle. We study the transitions between a drop shape and a column by incrementally varying the inter-fiber distance and find that the transition depends on the global geometry of the system as well as on the volume of liquid. More surprisingly we find that these two morphological states may coexist for certain parameter values. These switches in morphologies may be used to manipulate or transport liquid at a small scale.

  13. Digital microfluidics for automated hanging drop cell spheroid culture.

    Science.gov (United States)

    Aijian, Andrew P; Garrell, Robin L

    2015-06-01

    Cell spheroids are multicellular aggregates, grown in vitro, that mimic the three-dimensional morphology of physiological tissues. Although there are numerous benefits to using spheroids in cell-based assays, the adoption of spheroids in routine biomedical research has been limited, in part, by the tedious workflow associated with spheroid formation and analysis. Here we describe a digital microfluidic platform that has been developed to automate liquid-handling protocols for the formation, maintenance, and analysis of multicellular spheroids in hanging drop culture. We show that droplets of liquid can be added to and extracted from through-holes, or "wells," and fabricated in the bottom plate of a digital microfluidic device, enabling the formation and assaying of hanging drops. Using this digital microfluidic platform, spheroids of mouse mesenchymal stem cells were formed and maintained in situ for 72 h, exhibiting good viability (>90%) and size uniformity (% coefficient of variation microfluidic platform provides a viable tool for automating cell spheroid culture and analysis. © 2014 Society for Laboratory Automation and Screening.

  14. Shear-induced coalescence of emulsified oil drops.

    Science.gov (United States)

    Yeung, A; Moran, K; Masliyah, J; Czarnecki, J

    2003-09-15

    Crude oil droplets, when suspended in water, possess negative surface charges which give rise to double-layer repulsive forces between the drops. According to conventional DLVO theory, the magnitude of this repulsion (based on the measured zeta potential) is more than sufficient to prevent coalescence of the droplets. Indeed, when two such droplets were brought together on direct (i.e., "head-on") approach, coalescence was rarely observed. Upon oblique approach, however, the same droplets were seen to coalesce readily. An oblique encounter must necessarily give rise to lateral relative motion-or shearing-between the droplet surfaces. It is speculated that, if the charge distributions at the droplet surfaces were heterogeneous, lateral shearing would facilitate many encounters between surface patches of different zeta potentials across the intervening water film. If the repulsion across any local region were sufficiently weak to allow formation of an oil bridge across the water film, coalescence of the drops would follow inevitably. With the hypothesis of surface heterogeneity, it is not necessary to invoke any additional colloidal interactions (such as "hydrophobic forces") to account for the observed droplet-droplet coalescence. This finding may have important implications for the underlying mechanisms of emulsion stability in general and the commercial extraction of bitumen from oil sands in particular.

  15. Coalescence and Rebounding of Colliding Drops in Liquid Ambients

    Science.gov (United States)

    Salber, Shirin; Longmire, Ellen

    2003-11-01

    Flow visualization is performed on two water/glycerin droplets colliding in an immiscible liquid ambient. The drops, of equal size and velocity, are ejected from identical tubes opposite each other through means of a solenoid valve mechanism. Drop diameters are of order 1 cm. The Weber number is varied between 1 and 300 by adjusting the mass flow rate and solenoid valve open time. By using surrounding fluids of different viscosities, as well as by adjusting the mass flow rate and solenoid valve open time, the Reynolds number is varied between 1 and 500. Precise offset adjustments of the tubes are made to study a range of collisions varying from head-on to glancing. Flow behavior is observed as the two droplets directly approach, impact, and then bounce, coalesce, or separate. These outcomes are mapped into regions as functions of the Reynolds number, Weber number, and the normalized offset (i.e. impact parameter). Preliminary PIV experiments have been performed on index matched fluids to understand these events. The resulting velocity fields and the effect of seed particles on coalescence time will also be discussed. *supported by DOE (DE-FG02-98ER14869).

  16. QUANTUS: Implementing atom optical experiments in the Bremen drop tower

    Science.gov (United States)

    Müntinga, Hauke; van Zoest, T.; Ahlers, H.; Seidel, S. T.; Herr, W.; Rudolph, J.; Gaaloul, N.; Singh, Y.; Schulze, T. A.; Rode, C.; Schkolnik, V.; Ertmer, W.; Rasel, E.; Müntinga, H.; Künemann, T.; Resch, A.; Herrmann, S.; Lümmerzahl, C.; Dittus, H.; Vogel, A.; Wenzlawski, A.; Sengstock, K.; Meyer, N.; Bongs, K.; Krutzik, M.; Lewoczko-Adamczyk, W.; Schiemangk, M.; Peters, A.; Eckart, M.; Kajari, E.; Arnold, S.; Nandi, G.; Walser, R.; Schleich, W. P.; Steinmetz, T.; Hünsch, T. W.; Reichel, J.

    We report on the current status of the QUANTUS free fall BEC experiment at the ZARM drop tower in Bremen. After the first realization of a BEC in microgravity in 2007, we were able to observe conden-sates after an unprecedented time of free evolution. The extremely shallow traps possible in microgravity and resulting ultralow temperatures of a few nK allow for further studies ranging from coherence properties of condensates to inertial sensors based on matter waves. In our talk we will focus on technological challanges of the project and its roll in bringing matter wave optics into space. A drop tower experiment is considered a stepping stone towards the ISS or other platforms as it makes high demands on mechanical stability, power consumption and payload. After showing the feasibility of such a project we are now working on a second generation apparatus which leads the way to high precision measurements of gravitational forces and eventually a quantum test of Einstein's weak equivalence principle. These goals are worked on in close cooperation with QUEST and the projects PRIMUS and LASUS. The QUANTUS project is a collaboration of U Hamburg, U Ulm, HU Berlin, MPQ Munich, ZARM at U Bremen and LU Hannover. It is supported by the German Space Agency DLR with funds provided by the Federal Ministry of Economics and Technology (BMWi) under grant numbers 50WM0835 -50WM0839.

  17. Longitudinal drop-out and weighting against its bias.

    Science.gov (United States)

    Schmidt, Steffen C E; Woll, Alexander

    2017-12-08

    The bias caused by drop-out is an important factor in large population-based epidemiological studies. Many studies account for it by weighting their longitudinal data, but to date there is no detailed final approach for how to conduct these weights. In this study we describe the observed longitudinal bias and a three-step longitudinal weighting approach used for the longitudinal data in the MoMo baseline (N = 4528, 4-17 years) and wave 1 study with 2807 (62%) participants between 2003 and 2012. The most meaningful drop-out predictors were socioeconomic status of the household, socioeconomic characteristics of the mother and daily TV usage. Weighting reduced the bias between the longitudinal participants and the baseline sample, and also increased variance by 5% to 35% with a final weighting efficiency of 41.67%. We conclude that a weighting procedure is important to reduce longitudinal bias in health-oriented epidemiological studies and suggest identifying the most influencing variables in the first step, then use logistic regression modeling to calculate the inverse of the probability of participation in the second step, and finally trim and standardize the weights in the third step.

  18. Dropped-head in recessive oculopharyngeal muscular dystrophy.

    Science.gov (United States)

    Garibaldi, Matteo; Pennisi, Elena Maria; Bruttini, Mirella; Bizzarri, Veronica; Bucci, Elisabetta; Morino, Stefania; Talerico, Caterina; Stoppacciaro, Antonella; Renieri, Alessandra; Antonini, Giovanni

    2015-11-01

    A 69-year-old woman presented a dropped head, caused by severe neck extensor weakness that had started two years before. She had also developed a mild degree of dysphagia, rhinolalia, eyelid ptosis and proximal limb weakness during the last months. EMG revealed myopathic changes. Muscle MRI detected fatty infiltration in the posterior neck muscles and tongue. Muscle biopsy revealed fiber size variations, sporadic rimmed vacuoles, small scattered angulated fibers and a patchy myofibrillar network. Genetic analysis revealed homozygous (GCN)11 expansions in the PABPN1 gene that were consistent with recessive oculopharyngeal muscular dystrophy (OPMD). There are a few reports of the recessive form, which has a later disease onset with milder symptoms and higher clinical variability than the typical dominantly inherited form. This patient, who is the first Italian and the eighth worldwide reported case of recessive OPMD, is also the first case of OPMD with dropped-head syndrome, which thus expands the clinical phenotype of recessive OPMD. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Alcohol drops on miscible liquid: mixing or spreading?

    Science.gov (United States)

    Kim, Hyoungsoo; Muller, Koen; Shardt, Orest; Afkhami, Shahriar; Stone, Howard

    2016-11-01

    We studied how a sessile drop of alcohol behaves when placed on a fully miscible liquid. The dynamics of the subsequent mixing and spreading were captured by using a high-speed camera and investigated by varying parameters (e.g., surface tension, density, and viscosity). We observed that a deposited alcohol drop on a liquid bath remains as a floating lens shape, the alcohol liquid leaks out along the rim of the droplet, and it spreads axi-symmetrically along the bottom liquid interface. To visualize spreading and mixing features, we used time-resolved Particle Tacking Velocimetry and a Schlieren method. We observed a localized mixing flow at the rim of the floating droplet where the maximum flow speed is obtained, driven by a solutal Marangoni effect. Underneath the interface of the bath liquid, a viscous boundary layer develops while the alcohol liquid spreads along the radial direction. We also observed a finite quasi-steady interfacial flow velocity regime after the alcohol droplet touched the bottom liquid surface. In this regime, the flow speed linearly increases inside the floating lens, and outside the lens the flow speed decays along the r-direction with a power-law slope, Ur r - 1 / 2 . Physical arguments to support the observations will be discussed.

  20. Mouse cloning using a drop of peripheral blood.

    Science.gov (United States)

    Kamimura, Satoshi; Inoue, Kimiko; Ogonuki, Narumi; Hirose, Michiko; Oikawa, Mami; Yo, Masahiro; Ohara, Osamu; Miyoshi, Hiroyuki; Ogura, Atsuo

    2013-08-01

    Somatic cell nuclear transfer (SCNT) is a unique technology that produces cloned animals from single cells. It is desirable from a practical viewpoint that donor cells can be collected noninvasively and used readily for nuclear transfer. The present study was undertaken to determine whether peripheral blood cells freshly collected from living mice could be used for SCNT. We collected a drop of peripheral blood (15-45 μl) from the tail of a donor. A nucleated cell (leukocyte) suspension was prepared by lysing the red blood cells. Following SCNT using randomly selected leukocyte nuclei, cloned offspring were born at a 2.8% birth rate. Fluorescence-activated cell sorting revealed that granulocytes/monocytes and lymphocytes could be roughly distinguished by their sizes, the former being significantly larger. We then cloned putative granulocytes/monocytes and lymphocytes separately and obtained 2.1% and 1.7% birth rates, respectively (P > 0.05). Because the use of lymphocyte nuclei inevitably results in the birth of offspring with DNA rearrangements, we applied granulocyte/monocyte cloning to two genetically modified strains and two recombinant inbred strains. Normal-looking offspring were obtained from all four strains tested. The present study clearly indicated that genetic copies of mice could be produced using a drop of peripheral blood from living donors. This strategy will be applied to the rescue of infertile founder animals or a "last-of-line" animal possessing invaluable genetic resources.