WorldWideScience

Sample records for monitor iontophoretic ejections

  1. Natriuretic peptides in the monitoring of anthracycline induced reduction in left ventricular ejection fraction

    DEFF Research Database (Denmark)

    Daugaard, Gedske; Lassen, Ulrik; Bie, Peter;

    2005-01-01

    BACKGROUND: The use of anthracyclines in treatment of cancer is limited by cardiotoxicity of these compounds and may lead to heart failure. Therefore monitoring of cardiac function is necessary during therapy. AIM: We evaluated the value of natriuretic peptides (N-terminal pro-atrial natriuretic...... measurements, 19% showed a significant EF decrease (>0.10) and ended with a final EF value below 0.50. Baseline EF was no predictor of a change in EF during treatment. Neither baseline levels of N-ANP or BNP nor a change in the same variables during therapy were predictive of a change in EF. CONCLUSIONS...... peptide (N-ANP) and brain natriuretic peptide (BNP)) for monitoring and predicting anthracycline induced cardiotoxicity using radionuclide left ventricular ejection fraction (EF) measurements as reference. METHODS AND RESULTS: A total of 107 consecutive patients receiving anthracycline as part...

  2. Iontophoretic Transport Across a Multiple Membrane System

    OpenAIRE

    Molokhia, Sarah A.; Zhang, Yanhui; Higuchi, William I.; Li, S. Kevin

    2008-01-01

    The objective of the present study was to investigate the iontophoretic transport behavior across multiple membranes of different barrier properties. Spectra/Por® (SP) and Ionac membranes were the synthetic membranes and sclera was the biomembrane in this model study. The barrier properties of SP membranes were determined individually in passive and iontophoresis transport experiments with tetraethylammonium ion (TEA), chloride ion (Cl), and mannitol as the model permeants. Passive and iontop...

  3. Transdermal iontophoretic delivery of timolol maleate

    Directory of Open Access Journals (Sweden)

    Mayur Patni

    2012-12-01

    Full Text Available Transdermal iontophoresis would be a promising method for the systemic delivery of water soluble and ionic drugs of relatively high molecular size, including peptides. The objective of the present study was to investigate the effect of biological variable such as guinea pig and human cadaver skin and other variables like drug concentration, current density on the transdermal iontophoretic transport of timolol maleate. The permeation profile of drug using solution and gel formulation was studied and compared. For better bioavailability, better patient compliance, and enhanced delivery, an iontophoretic drug delivery system of a timolol maleate matrix gel was formulated using Carbopol 974P. The study was conducted using silver-silver chloride electrodes across the guinea pig and human cadaver skin. Viscosity measurements and flux calculations indicated the suitability of the Carbopol 974P gel for transdermal iontophoretic delivery of timolol maleate. Anodal iontophoresis with silver-silver chloride electrode significantly increased the timolol maleate skin permeation as compared with the passive permeation study. The amount of timolol maleate transported during iontophoresis was significantly different among the different skins. However, iontophoretic gel formulations provided required flux of drug through human cadaver skin.A iontoforese transdérmica seria um método promissor para a liberação sistêmica de fármacos solúveis em água e iônicos de relativamente elevado tamanho molecular, incluindo peptídeos. O objetivo do presente estudo foi investigar o efeito da variável biológica, tais como cobaia e pele de cadáver humano, e outras variáveis como concentração do fármaco, densidade de corrente sobre o transporte transdérmico iontoforético de maleato de timolol. Comparou-se o perfil de permeação do fármaco usando a formulação de solução e de gel. Para melhor biodisponibilidade, melhor adesão do paciente e libera

  4. Iontophoretic transdermal delivery of buspirone hydrochloride in hairless mouse skin.

    Science.gov (United States)

    Al-Khalili, Mohammad; Meidan, Victor M; Michniak, Bozena B

    2003-01-01

    The transdermal delivery of buspirone hydrochloride across hairless mouse skin and the combined effect of iontophoresis and terpene enhancers were evaluated in vitro using Franz diffusion cells. Iontophoretic delivery was optimized by evaluating the effect of drug concentration, current density, and pH of the vehicle solution. Increasing the current density from 0.05 to 0.1 mA/cm2 resulted in doubling of the iontophoretic flux of buspirone hydrochloride, while increasing drug concentration from 1% to 2% had no effect on flux. Using phosphate buffer to adjust the pH of the drug solution decreased the buspirone hydrochloride iontophoretic flux relative to water solutions. Incorporating buspirone hydrochloride into ethanol:water (50:50 vol/vol) based gel formulations using carboxymethylcellulose and hydroxypropylmethylcellulose had no effect on iontophoretic delivery. Incorporation of three terpene enhancers (menthol, cineole, and terpineol) into the gel resulted in a synergistic effect when combined with iontophoresis. Menthol was the most active enhancer, and when combined with iontophoresis it was possible to deliver 10 mg/cm2/day of buspirone hydrochloride.

  5. The response of single melanophores to extracellular and intracellular iontophoretic injection of melanocyte-stimulating hormone.

    Science.gov (United States)

    Horowitz, J M; Mikuckis, G M; Longshore, M A

    1980-03-01

    The purpose of this study was to determine if MSH, a peptide hormone, injected within a frog skin melanophore could elicit a physiological response, melanosome dispersion. Multibarreled electrodes were used to iontophoretically inject alpha-MSH inside frog skin melanophores of Rana pipiens pipiens. In 46 cells, intracellular MSH was ineffective in producing melanosome dispersion as viewed through the microscope. Because the frog skin is a complex of closely spaced cells, at times the microelectrode may have impaled cells other than melanophores. Therefore, in order to verify that the electrode was in a melanophore and not some other cell type, cAMP, shown to produce melanosome dispersion, was iontophoretically injected to 17 cells, causing the melanosomes to disperse. In these 17 cells, prior injection of MSH caused no dispersion. The response was monitored by observing the target cell with surrounding cells serving as a control. As an additional control to determine if adequate amounts of MSH were released, the electrode was withdrawn from the cell and placed near a group of melanophores, and in all cases the cells close to the electrode tip showed melanosome dispersion after MSH injection. The results of this study remain consistent with the view that MSH receptors in frog skin melanophores are located on the external surface of the plasma membrane, and MSH injected into the cytoplasm of the cell has no short term effect.

  6. Modified technique of iontophoretic anesthesia for myringotomy in children.

    Science.gov (United States)

    Epley, J M

    1977-06-01

    A modified technique is described for iontophoretic anesthesia in children who require myringotomy and insertion of a tube (tympanostomy). Principal modifications include the following procedures: (1) preoperative parenteral sedation; (2) relatively painless injection of lidocaine hydrochloride-epinephrine hydrochloride solution into the external auditory canal skin after iontophoresis alone to eliminate the extreme bony canal wall tenderness; (3) injection of lidocaine-epinephrine solution into an atelectatic middle ear to anesthetize the promontory for painless tube insertion; (4) substitution of a disposable ECG electrode for a metal plate electrode to eliminate the possibility of electrical burn from metal-to-skin contact. These modifications enhance the effectiveness and the safety of iontophoretic anesthesia, minimize the need for general anesthesia, and liberalize the indications for tympanostomy.

  7. Iontophoretically enhanced ciclopirox delivery into and across human nail plate.

    Science.gov (United States)

    Hao, Jinsong; Smith, Kelly A; Li, S Kevin

    2009-10-01

    Transungual delivery of antifungal drugs is hindered by the low permeability of human nail plates, and as such, repeated dosing over a long period of time is necessary for effective treatment. The objectives of this study were to explore the possibilities of (a) enhancing the delivery of ciclopirox (CIC) across human nail plates and (b) sustaining CIC delivery from the larger resultant drug depot in the nail plates with constant voltage iontophoresis. In vitro passive and 9 V cathodal iontophoretic transport experiments of CIC across human nails were performed. Transungual CIC delivery with Penlac was the control. The amounts of CIC released from and deposited in the nails were determined in drug release and extraction experiments, respectively. Iontophoresis increased the flux of CIC permeated across the nail approximately 10 times compared to passive delivery from the same formulation or from Penlac. A significant amount of CIC was loaded into and released from the nails; the CIC concentrations were estimated to be above the minimum inhibitory concentrations of CIC for dermatophytic molds. The apparent transport lag time decreased in iontophoretic transport. The results demonstrate that iontophoresis was able to deliver an effective amount of CIC into and across the nails, and this suggests the feasibility of a constant voltage battery-powered transungual iontophoretic device.

  8. Mechanistic Studies of the Transdermal Iontophoretic Delivery of 5-OH-DPAT In Vitro

    NARCIS (Netherlands)

    Ackaert, Oliver W.; Van Smeden, Jeroen; De Graan, Jeroen; Dijkstra, Durk; Danhof, Meindert; Bouwstra, Joke A.

    2010-01-01

    A characterization and optimization of the in vitro transdermal iontophoretic transport of 5-hydroxy-2-(N,N,-di-n-propylamino)tetralin (5-OH-DPAT) is presented. The utility of acetaminophen as a marker of electroosmotic flow was studied as well. The following parameters of iontophoretic transport of

  9. Transdermal iontophoretic delivery of a novel series of dopamine agonists in vitro : physicochemical considerations

    NARCIS (Netherlands)

    Ackaert, Oliver W.; De Graan, Jeroen; Capancioni, Romano; Dijkstra, Durk; Danhof, Meindert; Bouwstra, Joke A.

    2010-01-01

    Objectives The transdermal iontophoretic delivery of a novel series of 2- aminotetralins and chromanamine-based dopamine agonists was investigated in corn. Methods Systematic structural modifications allowed us to investigate their effect on solubility in the donor phase and iontophoretic delivery a

  10. Effect of microporation on passive and iontophoretic delivery of diclofenac sodium.

    Science.gov (United States)

    Patel, Hiren; Joshi, Abhay; Joshi, Amit; Stagni, Grazia

    2015-01-01

    Skin pretreatment with a microneedle roller (microporation (MP)) appears a simple and inexpensive technique to increase transdermal delivery of topically applied drug products. This study investigates the effect of MP on the passive and iontophoretic delivery of diclofenac (DCF) by quantifying dermis and plasma levels of DCF in a rabbit model. New Zealand albino female rabbits received either: (i) a topical application of 4 g of Voltaren® 1% gel with or without pretreatment with a microroller (0.5 mm needle length; density 23 microneedles per cm(2) area) or (ii) a DCF solution (40 mg/2.5 mL) via iontophoresis (IOMED transQ(E) medium size patch), with or without microroller pretreatment. A 300 µA/cm(2) cathodic current was applied for 20 min for a total of 80 mA. DCF concentrations were monitored in dermis with microdialysis sampling every 20 min for 5 h. Plasma samples were collected over the same period. In the passive delivery studies, microroller pretreatment increased Cmax by 1.5- and 2.0-fold in skin and plasma, respectively, and AUC by 1.5- and 2.4-fold in skin and plasma, respectively. In the iontophoresis delivery studies, microporation increased Cmax by 2.0-fold both in skin and in plasma, and AUC by 1.1- and 1.8-fold in skin and plasma, respectively. In conclusion, microneedle pretreatment increased significantly the systemic exposure of DCF from either passive or iontophoretic delivery, whereas the effect in skin was less pronounced.

  11. Iontophoretic delivery of 5-fluorouracil through excised human stratum corneum.

    Science.gov (United States)

    Singh, B N; Jayaswal, S B

    2008-04-01

    The objective of this study was to determine the effects of ionization, current density and penetration enhancers on the iontophoretic delivery of 5-fluorouracil (5-FU) through excised human stratum corneum (HSC). The iontophoretic (cathodal) transport of 5-FU was assessed in vitro at three physiologically relevant pH values of 5.0, 7.4 and 8.0, at various levels of current density ranging between 0.15 to 0.98 mA/cm2, and in the presence of suitable penetration enhancers, namely Azone(®) (AZ), lauryl alcohol (LA), and isopropyl myristate (IPM). The steady-state flux at constant current density (0.47 mA/cm(2)) was increased by approximately 19, 10 and 27 fold at pH 5, 7.4 and 8.0, respectively. The effect of current density at pH 7.4 exhibited a linear correlation between current density and steady-state flux (r = 0.98, p = 0.002), which indicates the potential of iontophoresis for controlled transdermal delivery of 5-FU. The combination of cathodal iontophoresis with IPM produced an additive enhancement which may be attributed to aggravated skin perturbation effect and increased skin conductivity. Other enhancers such as AZ and LA produced negative or no further enhancement respectively, when used in conjunction with cathodal iontophoresis. It may be therefore concluded that pH and current density play critical role during iontophoretic delivery of 5-FU, and combination of a chemical penetration enhancer and iontophoresis can not be always viewed as a synergistic strategy which should be evaluated on a case-by-case basis for each drug candidate/enhancer combination.

  12. Subcutaneous concentrations following topical iontophoretic delivery of diclofenac.

    Science.gov (United States)

    Kasha, P C; Anderson, C R; Morris, R L; Sembrowich, W L; Chaturvedula, A; Banga, A K

    2012-10-01

    A self-contained Wearable Electronic Disposable Drug Delivery (WEDD(®)) patch was used to demonstrate that diclofenac levels delivered by iontophoresis are greater than estimated minimal effective concentrations in local subcutaneous tissue and are also greater than either passive transdermal or intravenous delivery using hairless rats. In vitro iontophoretic delivery was evaluated to optimize donor cell formulation using Franz diffusion cells and 1000 NMWL Millipore ultrafiltration membrane. In vivo animal studies were done using patches powered with a 4-volt system, consisting of a 1-volt Zn anode and Ag/AgCl cathode with built in 3-volt lithium battery. Blood and microdialysis samples were collected at different time points after patch application. Current levels increased to 1.0 mA at 30 min, then fell to a steady state of ~ 0.4 mA. Both WEDD(®) and passive patches produced measurable levels of diclofenac in the subcutaneous tissue below the application site (C(max) ± SE = 113.3 ± 61.7 ng/mL and 36.3 ± 15.9 ng/mL, respectively). The dose delivered in six hours was calculated to be 0.226 ± 0.072 mg and 0.430 ± 0.048 mg in passive and iontophoretic delivery, respectively. Diclofenac was not detected in the subcutaneous tissue after intravenous administration of 1.5 mg/kg diclofenac solution. The trend indicates that WEDD(®) can be used to successfully deliver diclofenac to subcutaneous tissue to concentrations higher when compared to either passive delivery or intravenous dosing of 1.5 mg/kg.

  13. A Phase I, Open-Label, Single-Dose Safety, Pharmacokinetic, and Tolerability Study of the Sumatriptan Iontophoretic Transdermal System in Adolescent Migraine Patients.

    Science.gov (United States)

    Gutman, Dikla; Hellriegel, Edward; Aycardi, Ernesto; Bigal, Marcelo E; Kunta, Jeevan; Chitra, Rohini; Kansagra, Sujay; Kidron, Orna Srur; Knebel, Helena; Linder, Steven; Ma, Yuju; Pierce, Mark; Winner, Paul K; Spiegelstein, Ofer

    2016-09-01

    To evaluate the safety, tolerability, and pharmacokinetics of sumatriptan delivered by the iontophoretic transdermal system (TDS) in adolescent patients. Since nausea can be a prominent and early symptom of migraine, nonoral treatment options are often required. Sumatriptan iontophoretic TDS is approved for the acute treatment of migraine in adults. The present study evaluates the pharmacokinetics of sumatriptan administered via the iontophoretic TDS in adolescents, contrasting the findings with historical data from adults. Patients aged 12-17 years (inclusive) with acute migraine were treated with sumatriptan iontophoretic TDS for 4 hours. Blood samples for pharmacokinetic profiling of sumatriptan were obtained prior to dosing and at predetermined time points covering the 12 hours postonset of treatment. Key pharmacokinetic endpoints included Cmax (peak plasma drug concentration), tmax (time to Cmax ), AUC0-∞ (area under the plasma concentration-time curve from time 0 to infinity), and t½ (terminal elimination half-life). Safety was evaluated by monitoring of adverse events in addition to laboratory and clinical assessments. The sample consisted of 37 patients, and 36 were included in the PK evaluable population. Cmax , tmax , AUC0-∞ , and t½ values were all similar between male and female patients and between younger (12-14 years) and older (15-17 years) adolescents. When compared with historical adult data, adolescent patients demonstrated similar systemic exposures to those observed in adults (mean Cmax 20.20 (±6.43) ng/mL in adolescents vs 21.89 (±6.15) ng/mL in adults; mean AUC0-∞ 98.1 (±28.1) ng·h/mL in adolescents vs 109.7 (±26.1) ng·h/mL in adults). All adverse events were mild or moderate, with application-site paresthesia being the most common (32%). No clinically relevant changes in laboratory values, vital signs, or electrocardiogram findings were observed. The iontophoretic TDS produced mean systemic exposures to sumatriptan in younger

  14. In vivo iontophoretic delivery of salmon calcitonin across microporated skin.

    Science.gov (United States)

    Vemulapalli, Viswatej; Bai, Yun; Kalluri, Haripriya; Herwadkar, Anushree; Kim, Hyun; Davis, Shawn P; Friden, Phil M; Banga, Ajay K

    2012-08-01

    The purpose of this study was to determine the effect of microneedle (MN) technology and its combination with iontophoresis (ITP) on the in vivo transdermal delivery of salmon calcitonin (sCT). Maltose MNs (500 µm) were used to porate skin prior to application of the drug, with or without ITP. Micropores created by maltose MNs were characterized by histological sectioning and calcein imaging studies, which indicated uniformity of the created micropores. In vivo studies were performed in hairless rats to assess the degree of enhancement achieved by ITP (0.2 mA/cm² for 1 h), MNs (81 MNs), and their combination. In vivo studies indicate a serum maximal concentration of 0.61 ± 0.42 ng/mL, 1.79 ± 0.72 ng/mL, and 5.51 ± 0.32 ng/mL for ITP, MNs, and combination treatment, respectively. MN treatment alone increased serum concentration 2.5-fold and the combination treatment increased the concentration ninefold as compared with iontophoretic treatment alone. Combination treatment of ITP and MNs resulted in the highest delivery of sCT and therapeutic levels were achieved within 5 min of administration.

  15. Fentanyl Iontophoretic Transdermal System: A Review in Acute Postoperative Pain.

    Science.gov (United States)

    Scott, Lesley J

    2016-04-01

    Fentanyl iontophoretic transdermal system (ITS) [Ionsys(®)] is indicated for the management of acute postoperative pain in adults requiring opioid analgesia in the hospital setting. This article reviews the clinical use of fentanyl ITS for postoperative pain management, and summarizes the pharmacology of fentanyl and the characteristics of the two-component fentanyl ITS (Ionsys(®)) device. In well-designed, multicentre clinical trials, fentanyl ITS was an effective and generally well tolerated method for managing acute postoperative pain in inpatients who had undergone major abdominal, thoracic or orthopaedic surgery. Overall, fentanyl ITS provided equivalent analgesic efficacy to that with morphine patient-controlled intravenous analgesia (PCIA), but was perceived to be more convenient/easier to use than morphine PCIA by patients, nurses and physical therapists. Patients receiving fentanyl ITS also had a greater ability to mobilize after surgery than patients receiving morphine PCIA. In addition, relative to morphine PCIA, fentanyl ITS offers advantages in terms of the noninvasive administrative route (i.e. transdermal needle-free administration), pre-programmed delivery (no risk of programming errors/incorrect dosing) and improved tolerability with regard to the overall incidence of opioid-related adverse events (ORAEs) and some individual ORAEs. Hence, fentanyl ITS is a useful option for the management of acute postoperative pain in adults requiring opioid analgesia in the hospital setting.

  16. Ejection Tower Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Ejection Tower Facility's mission is to test and evaluate new ejection seat technology being researched and developed for future defense forces. The captive and...

  17. Correlation of transdermal iontophoretic phenylalanine and mannitol transport: test of the internal standard concept under DC iontophoresis and constant resistance AC iontophoresis conditions.

    Science.gov (United States)

    Yan, Guang; Higuchi, William I; Szabo, Aniko; Li, S Kevin

    2004-07-23

    The purpose of this study was to test the feasibility of using an internal standard approach to predict the transdermal flux of phenylalanine (Phe) across human epidermal membrane (HEM) in vitro during iontophoresis of constant direct current (DC), constant skin resistance alternating current (AC) with DC offset (AC-plus-DC), symmetric constant resistance AC (AC-only), and constant current DC with the application of a polyelectrolyte. Under the constant current DC and AC-plus-DC conditions, a linear relationship between the permeation of Phe and that of mannitol was observed with a slope close to unity. The ratios of the Phe permeability coefficients to those of mannitol during iontophoresis with different HEM samples were essentially constant with significantly smaller inter-sample and intra-sample variabilities than those of the raw Phe permeability coefficient data. This demonstrates that mannitol is a good internal standard for predicting the transdermal iontophoretic flux of Phe under these two conditions. On the other hand, the correlations of the permeability coefficients of Phe and mannitol under the AC-only iontophoresis and iontophoresis with the polyelectrolyte are poorer than those observed during DC and AC-plus-DC iontophoresis. The poor correlations are believed to be related to Phe being a zwitterion and its anionic form in HEM. Previously, iontophoretic transport of glucose has been demonstrated to be essentially the same as that of mannitol. The good correlations between Phe and mannitol transport across HEM during DC and AC-plus-DC iontophoresis in the present study therefore suggest that glucose and its extraction can be used as the internal standard for iontophoretic Phe monitoring.

  18. Transdermal iontophoretic delivery of apomorphine in patients improved by surfactant formulation pretreatment

    NARCIS (Netherlands)

    Li, GL; de Vries, Joeke; van Steeg, TJ; van den Busche, H; Maas, HJ; Reeuwijk, HJEM; Danhof, M; Bouwstra, JA; van Laar, T

    2005-01-01

    The objective of the present study is to evaluate the efficacy and the safety of transdermal iontophoretic delivery of Rapomorphine, a potent dopamine agonist, in combination with surfactant pretreatment in patients with advanced Parkinson's disease. Iontophoresis patches were applied in 16 patients

  19. Cutaneous metabolism, tissue binding, lipophilicity and electroosmosis : relevance for iontophoretic enhancement

    OpenAIRE

    Altenbach, Melanie Pamela

    2005-01-01

    In this work passive and iontophoretic transport of a dipeptide, Tyrosine-Phenylalanine (TyrPhe), a protected amino acid, Tyrosine-β-Naphthylamide (Tyrβ-NA), and a glucose derivative, Benzyl-2-Acetamido-2-deoxy-α-D-glucopyranoside (BAd-α-Glc), was investigated across heat-separated human epidermis in vitro. The modified Nernst-Planck Equation was used to theoretically describe permeation of these compounds. Permeation experiments were carried out with custom-made glass diffusion cells connect...

  20. Long-term recording of cardiac arrhythmias with an implantable cardiac monitor in patients with reduced ejection fraction after acute myocardial infarction: the Cardiac Arrhythmias and Risk Stratification After Acute Myocardial Infarction (CARISMA) study

    DEFF Research Database (Denmark)

    Bloch Thomsen, Poul Erik; Jons, Christian; Raatikainen, M J Pekka

    2010-01-01

    Knowledge about the incidence of cardiac arrhythmias after acute myocardial infarction has been limited by the lack of traditional ECG recording systems to document and confirm asymptomatic and symptomatic arrhythmias. The Cardiac Arrhythmias and Risk Stratification After Myocardial Infarction (C...... (CARISMA) trial was designed to study the incidence and prognostic significance of arrhythmias documented by an implantable cardiac monitor among patients with acute myocardial infarction and reduced left ventricular ejection fraction.......Knowledge about the incidence of cardiac arrhythmias after acute myocardial infarction has been limited by the lack of traditional ECG recording systems to document and confirm asymptomatic and symptomatic arrhythmias. The Cardiac Arrhythmias and Risk Stratification After Myocardial Infarction...

  1. Effects of ionic strength on passive and iontophoretic transport of cationic permeant across human nail.

    Science.gov (United States)

    Smith, Kelly A; Hao, Jinsong; Li, S Kevin

    2009-06-01

    Transport across the human nail under hydration can be modeled as hindered transport across aqueous pore pathways. As such, nail permselectivity to charged species can be manipulated by changing the ionic strength of the system in transungual delivery to treat nail diseases. The present study investigated the effects of ionic strength upon transungual passive and iontophoretic transport. Transungual passive and anodal iontophoretic transport experiments of tetraethylammonium ion (TEA) were conducted under symmetric conditions in which the donor and receiver had the same ionic strength in vitro. Experiments under asymmetric conditions were performed to mimic the in vivo conditions. Prior to the transport studies, TEA uptake studies were performed to assess the partitioning of TEA into the nail. Permselectivity towards TEA was inversely related to ionic strength in both passive and iontophoretic transport. The permeability and transference number of TEA were higher at lower ionic strengths under the symmetric conditions due to increased partitioning of TEA into the nail. Transference numbers were smaller under the asymmetric conditions compared with their symmetric counterparts. The results demonstrate significant ionic strength effects upon the partitioning and transport of a cationic permeant in transungual transport, which may be instrumental in the development of transungual delivery systems.

  2. Influence of pH on transungual passive and iontophoretic transport.

    Science.gov (United States)

    Smith, Kelly A; Hao, Jinsong; Li, S Kevin

    2010-04-01

    The present study investigated the effects of pH on nail permeability and the transport of ions such as sodium (Na) and chloride (Cl) ions endogenous to nail and hydronium and hydroxide ions present at low and high pH, which might compete with drug transport across hydrated nail plate during iontophoresis. Nail hydration and passive transport of water across the nail at pH 1-13 were assessed. Subsequently, passive and iontophoretic transport experiments were conducted using (22)Na and (36)Cl ions under various pH conditions. Nail hydration was independent of pH under moderate pH conditions and increased significantly under extreme pH conditions (pH >11). Likewise, nail permeability for water was pH independent at pH 1-10 and an order of magnitude higher at pH 13. The results of passive and iontophoretic transport of Na and Cl ions are consistent with the permselective property of nail. Interestingly, extremely acidic conditions (e.g., pH 1) altered nail permselectivity with the effect lasting several days at the higher pH conditions. Hydronium and hydroxide ion competition in iontophoretic transport was generally negligible at pH 3-11 was significant at the extreme pH conditions studied. 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  3. Iontophoretic Permeation of Lisinopril at Different Current Densities and Drug Concentrations

    Directory of Open Access Journals (Sweden)

    Ashish Jain

    2012-08-01

    Full Text Available Purpose: The purpose of the present work was to assess iontophoretic permeation of Lisinopril at different current densities and concentrations for development of patient-controlled active transdermal system. Methods: In vitro iontophoretic transdermal delivery of Lisinopril across the pigskin was investigated at three different drug concentrations and three different current densities (0.25- 0.75 mA/cm2 in the donor cell of the diffusion apparatus, using cathodal iontophoresis along with the passive controls. Results: For passive permeation, the steady state flux significantly increased with the increasing of donor drug concentration. At all concentration levels, iontophoresis considerably increased the permeation rate compared to passive controls. Iontophoretic transport of Lisinopril was to be found increase with current densities. Flux enhancement was highest at the lowest drug load and lowest at the highest drug load. Conclusion: The obtained results indicate that permeation rate of Lisinopril across the pigskin can be considerably enhanced, controlled or optimized by the use of Iontophoresis technique.

  4. Osmotic pressure: resisting or promoting DNA ejection from phage

    CERN Document Server

    Jeembaeva, Meerim; Larsson, Frida; Evilevitch, Alex

    2008-01-01

    Recent in vitro experiments have shown that DNA ejection from bacteriophage can be partially stopped by surrounding osmotic pressure when ejected DNA is digested by DNase I on the course of ejection. We argue in this work by combination of experimental techniques (osmotic suppression without DNaseI monitored by UV absorbance, pulse-field electrophoresis, and cryo-EM visualization) and simple scaling modeling that intact genome (i.e. undigested) ejection in a crowded environment is, on the contrary, enhanced or eventually complete with the help of a pulling force resulting from DNA condensation induced by the osmotic stress itself. This demonstrates that in vivo, the osmotically stressed cell cytoplasm will promote phage DNA ejection rather than resisting it. The further addition of DNA-binding proteins under crowding conditions is shown to enhance the extent of ejection. We also found some optimal crowding conditions for which DNA content remaining in the capsid upon ejection is maximum, which correlates well...

  5. Black Hole Induced Ejections

    OpenAIRE

    Pelletier, G.

    2004-01-01

    Black Holes generate a particular kind of environments dominated by an accretion flow which concentrates a magnetic field. The interplay of gravity and magnetism creates this paradoxical situation where relativistic ejection is allowed and consequently high energy phenomena take place. Therefore Black Holes, which are very likely at the origin of powerfull astrophysical phenomena such as AGNs, micro- quasars and GRBs where relativistic ejections are observed, are at the heart of high energy a...

  6. Influence of pH on Transungual Passive and Iontophoretic Transport

    OpenAIRE

    Smith, Kelly A.; HAO, JINSONG; Li, S. Kevin

    2010-01-01

    The present study investigated the effects of pH on nail permeability and the transport of ions such as sodium (Na) and chloride (Cl) ions endogenous to nail and hydronium and hydroxide ions present at low and high pH, which might compete with drug transport across hydrated nail plate during iontophoresis. Nail hydration and passive transport of water across the nail at pH 1–13 were assessed. Subsequently, passive and iontophoretic transport experiments were conducted using 22Na and 36Cl ions...

  7. Influence of pH on Transungual Passive and Iontophoretic Transport

    OpenAIRE

    Smith, Kelly A; Hao, Jinsong; Li, S. Kevin

    2010-01-01

    The present study investigated the effects of pH on nail permeability and the transport of ions such as sodium (Na) and chloride (Cl) ions endogenous to nail and hydronium and hydroxide ions present at low and high pH, which might compete with drug transport across hydrated nail plate during iontophoresis. Nail hydration and passive transport of water across the nail at pH 1–13 were assessed. Subsequently, passive and iontophoretic transport experiments were conducted using 22Na and 36Cl ions...

  8. Patient considerations in the use of transdermal iontophoretic fentanyl for acute postoperative pain

    Directory of Open Access Journals (Sweden)

    Hartrick CT

    2016-04-01

    Full Text Available Craig T Hartrick,1 Cecile R Pestano,1 Li Ding,2 Hassan Danesi,2 James B Jones,2 1Beaumont Health System, Troy, MI, 2The Medicines Company, Parsippany, NJ, USA Abstract: Opioids are commonly used in the management of moderate-to-severe postoperative pain. Patient-controlled analgesic techniques are recognized as preferred administration methods. Previously, research has focused on intravenously administered opioids via a programmable pump. More recently, an iontophoretic transdermal system (ITS, which is patient controlled, has been developed. The focus of this review is on pain management using the fentanyl ITS during the 24–72-hour time period immediately following surgery. Fentanyl ITS offers a needle-free alternative to traditional intravenous (IV patient-controlled analgesia (PCA system that is as effective and safe as IV PCA. This system is easy to use for both patients and nurses. The use of fentanyl ITS is generally associated with a better ease-of-care profile, including a greater ease of mobility, from a patients' perspective when compared with morphine IV PCA. Keywords: patient-controlled analgesia, fentanyl iontophoretic transdermal system, ease of care, mobility, patient perspective, review

  9. Iontophoretic delivery of lipophilic and hydrophilic drugs from lipid nanoparticles across human skin.

    Science.gov (United States)

    Charoenputtakun, Ponwanit; Li, S Kevin; Ngawhirunpat, Tanansait

    2015-11-10

    The combined effects of iontophoresis and lipid nanoparticles on drug delivery across human epidermal membrane (HEM) were investigated. The delivery of lipophilic and hydrophilic drugs, all trans-retinoic acid (ATRA), salicylate (SA), and acyclovir (ACV), across HEM from lipid nanoparticles, solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), was compared in passive and iontophoresis experiments in vitro. Iontophoresis experiments were also performed with synthetic Nuclepore membrane for comparison. Drug distribution in the skin after iontophoretic delivery with the lipid nanoparticles was examined using a model probe rhodamine B base (RhoB). The drug-loaded lipid nanoparticles had average sizes of ∼ 118-169 nm and a negative zeta potential. Iontophoresis did not enhance the delivery of ATRA across HEM from SLN and NLC. However, HEM distribution study of RhoB suggested that lipophilic drugs could be delivered into the deeper layer of the skin following iontophoretic delivery of the drugs from the lipid nanoparticles. Iontophoresis enhanced the delivery of hydrophilic drug SA with the lipid nanoparticles. Similarly, iontophoresis enhanced the delivery of ACV when it was loaded in SLN. These results suggest that lipid nanoparticles are a promising drug delivery method that can be combined with iontophoresis to improve skin delivery of hydrophilic drugs.

  10. Coronal Mass Ejections

    Science.gov (United States)

    Crooker, Nancy; Joselyn, Jo Ann; Feynman, Joan

    The early 1970's can be said to mark the beginning of The Enlightenment in the history of the Space Age, literally as well as by analogy to European history. Instruments blinded by Earth's atmosphere were lifted above and, for the first time, saw clearly and continuously the ethereal white light and sparkling x-rays from the solar corona. From these two bands of the light spectrum came images of coronal mass ejections and coronal holes, respectively. But whereas coronal holes were immediately identified as the source of high-speed solar wind streams, at first coronal mass ejections were greeted only by a sense of wonder. It took years of research to identify their signatures in the solar wind before the fastest ones could be identified with the well-known shock disturbances that cause the most violent space storms.

  11. Coronal Mass Ejections

    CERN Document Server

    Kunow, H; Linker, J. A; Schwenn, R; Steiger, R

    2006-01-01

    It is well known that the Sun gravitationally controls the orbits of planets and minor bodies. Much less known, however, is the domain of plasma fields and charged particles in which the Sun governs a heliosphere out to a distance of about 15 billion kilometers. What forces activates the Sun to maintain this power? Coronal Mass Ejections (CMEs) and their descendants are the troops serving the Sun during high solar activity periods. This volume offers a comprehensive and integrated overview of our present knowledge and understanding of Coronal Mass Ejections (CMEs) and their descendants, Interplanetary CMEs (ICMEs). It results from a series of workshops held between 2000 and 2004. An international team of about sixty experimenters involved e.g. in the SOHO, ULYSSES, VOYAGER, PIONEER, HELIOS, WIND, IMP, and ACE missions, ground observers, and theoreticians worked jointly on interpreting the observations and developing new models for CME initiations, development, and interplanetary propagation. The book provides...

  12. Black Hole Induced Ejections

    CERN Document Server

    Pelletier, G

    2004-01-01

    Black Holes generate a particular kind of environments dominated by an accretion flow which concentrates a magnetic field. The interplay of gravity and magnetism creates this paradoxical situation where relativistic ejection is allowed and consequently high energy phenomena take place. Therefore Black Holes, which are very likely at the origin of powerfull astrophysical phenomena such as AGNs, micro- quasars and GRBs where relativistic ejections are observed, are at the heart of high energy astrophysics. The combination of General Relativity and Magneto-HydroDynamics (MHD) makes theory difficult; however great pionneers opened beautiful tracks in the seventies and left important problems to be solved for the next decades. These lectures will present the status of these issues. They have a tutorial aspect together with critical review aspect and contain also some new issues. Most of these lectures has been presented at the "School on Black Hole in the Universe" at Cargese, in May 2003.

  13. Controlled iontophoretic delivery of pramipexole: electrotransport kinetics in vitro and in vivo.

    Science.gov (United States)

    Kalaria, Dhaval R; Patel, Pratikkumar; Merino, Virginia; Patravale, Vandana B; Kalia, Yogeshvar N

    2014-09-01

    The objective of the study was to investigate the anodal iontophoretic delivery of pramipexole (PRAM), a dopamine agonist used for the treatment of Parkinson's disease, in order to determine whether therapeutic amounts of the drug could be delivered across the skin. Preliminary iontophoretic experiments were performed in vitro using porcine ear and human abdominal skin. These were followed by a pharmacokinetic study in male Wistar rats to determine the drug input rate in vivo. Stability studies revealed that after current application (0.5 mA/cm(2) for 6h), the solution concentration of PRAM was only 60.2 ± 5.3% of its initial value. However, inclusion of sodium metabisulfite (0.5%), an antioxidant, increased this to 97.2 ± 3.1%. Iontophoretic transport of PRAM across porcine skin in vitro was studied as a function of current density (0.15, 0.3, 0.5 mA/cm(2)) and concentration (10, 20, 40 mM). Increasing the current density from 0.15 to 0.3 and 0.5 mA/cm(2), resulted in 2.5- and 4-fold increases in cumulative permeation, from 309.5 ± 80.2 to 748.8 ± 148.1 and 1229.1 ± 138.6 μg/cm(2), respectively. Increasing the PRAM concentration in solution from 10 to 20 and 40 mM resulted in a 2-fold increase in cumulative permeation (816.4 ± 123.3, 1229.1 ± 138.6 and 1643.6 ± 201.3 μg/cm(2), respectively). Good linearity was observed between PRAM flux and both the applied current density (r(2)=0.98) and drug concentration in the formulation (r(2)=0.99). Co-iontophoresis of acetaminophen showed that electromigration was the dominant electrotransport mechanism (accounting for >80% of delivery) and that there was no inhibition of electroosmotic flow at any current density. Cumulative iontophoretic permeation across human and porcine skin (after 6h at 0.5 mA/cm(2)) was also shown to be statistically equivalent (1229.1 ± 138.6 and 1184.8 ± 236.4 μg/cm(2), respectively). High transport and delivery efficiencies were achieved for PRAM (up to 7% and 58%, respectively). The

  14. The in vitro and in vivo evaluation of new synthesized prodrugs of 5-OH-DPAT for iontophoretic delivery

    NARCIS (Netherlands)

    Ackaert, O. W.; De Graan, J.; Capancioni, R.; Della Pasqua, O. E.; Dijkstra, D.; Westerink, B. H.; Danhof, M.; Bouwstra, J. A.

    2010-01-01

    The feasibility of transdermal iontophoretic transport of 4 novel ester prodrugs of 5-OH-DPAT (glycine-, proline-, valine- and (beta-alanine-5-OH-DPAT) was investigated in vitro and in vivo. Based on the chemical stability of the prodrugs, the best candidates were selected for in vitro transport stu

  15. NEUROCHEMICAL LESIONING IN THE RAT-BRAIN WITH IONTOPHORETIC INJECTION OF THE 1-METHYL-4-PHENYLPYRIDINIUM ION (MPP+)

    NARCIS (Netherlands)

    TERHORST, GJ; KNIGGE, MF; VANDERWAL, A

    1992-01-01

    Iontophoretic injections of the 1-methyl-4-phenylpyridinium ion (MPP+) were made in the dopaminergic part of the substantia nigra to see whether this injection technique could be used for inducing localized neurochemical lesions in dopaminergic cell groups and to assess the effects of MPP+ on non-do

  16. Iontophoretic delivery of lisinopril: Optimization of process variables by Box-Behnken statistical design.

    Science.gov (United States)

    Gannu, Ramesh; Yamsani, Vamshi Vishnu; Palem, Chinna Reddy; Yamsani, Shravan Kumar; Yamsani, Madhusudan Rao

    2010-01-01

    The objective of the investigation was to optimize the iontophoresis process parameters of lisinopril (LSP) by 3 x 3 factorial design, Box-Behnken statistical design. LSP is an ideal candidate for iontophoretic delivery to avoid the incomplete absorption problem associated after its oral administration. Independent variables selected were current (X(1)), salt (sodium chloride) concentration (X(2)) and medium/pH (X(3)). The dependent variables studied were amount of LSP permeated in 4 h (Y(1): Q(4)), 24 h (Y(2): Q(24)) and lag time (Y(3)). Mathematical equations and response surface plots were used to relate the dependent and independent variables. The regression equation generated for the iontophoretic permeation was Y(1) = 1.98 + 1.23X(1) - 0.49X(2) + 0.025X(3) - 0.49X(1)X(2) + 0.040X(1)X(3) - 0.010X(2)X(3) + 0.58X(1)(2) - 0.17X(2)(2) - 0.18X(3)(2); Y(2) = 7.28 + 3.32X(1) - 1.52X(2) + 0.22X(3) - 1.30X(1)X(2) + 0.49X(1)X(3) - 0.090X(2)X(3) + 0.79X(1)(2) - 0.62X(2)(2) - 0.33X(3)(2) and Y(3) = 0.60 + 0.0038X(1) + 0.12X(2) - 0.011X(3) + 0.005X(1)X(2) - 0.018X(1)X(3) - 0.015X(2)X(3) - 0.00075X(1)(2) + 0.017X(2)(2) - 0.11X(3)(2). The statistical validity of the polynomials was established and optimized process parameters were selected by feasibility and grid search. Validation of the optimization study with 8 confirmatory runs indicated high degree of prognostic ability of response surface methodology. The use of Box-Behnken design approach helped in identifying the critical process parameters in the iontophoretic delivery of lisinopril.

  17. Action as ejection.

    Science.gov (United States)

    Franco, Daisy

    2006-01-01

    The systematic analysis of acting-out episodes can be used in assessing analytic progress. Variables to be considered are the nature of the wish, the type of defense, and the degree of concreteness (versus symbolization) of the mental processes used in attempting actualization (as distinct from the resort to action). Two acting-out episodes of a borderline patient who acted out as a character trait, both occurring outside the analytic setting, are presented as illustrations. In the first one, occurring relatively early in the analysis, when split-off negative and positive self-images had to be rigidly maintained, ejection of the negative self-image was actualized via the regressive use of a symbolic equation and the mechanism of displacement, obliterating the distinction between an internal feeling and an external thing that here was literally thrown out. The later episode, occurring after the split was healed and within the context of a frustrating heterosexual involvement, contained an acted-out allusion to identification and competition with the mother. As in a dream, via associations, an unconscious wish for oedipal victory was revealed. Whereas in the first episode the goal of ejection was central, with splitting and denial the underlying defenses, it was absent from the second, in which an attempt was made to actualize a repressed infantile wish and made greater use of symbolization. It is concluded that acting-out episodes at different periods of the analysis, when systematically analyzed, can serve in assessing a patient's progress.

  18. In vivo determination of the diclofenac skin reservoir: comparison between passive, occlusive, and iontophoretic application.

    Science.gov (United States)

    Clijsen, Ron; Baeyens, Jean Pierre; Barel, André Odilon; Clarys, Peter

    2015-01-01

    There is scarce information concerning the pharmacodynamic behavior of topical substances used in the physiotherapy setting. The aim of the present study was to estimate the formation and emptying of the diclofenac (DF) skin reservoir after passive, semiocclusive, and electrically assisted applications of DF. Five different groups of healthy volunteers (ntotal=60, 23 male and 37 female), participated in this study. A 1% DF (Voltaren Emulgel) formulation (12 mg) was applied on the volar forearms on randomized defined circular skin areas of 7 cm(2). DF was applied for 20 minutes under three different conditions at the same time. The presence of DF in the skin results in a reduction of the methyl nicotinate (MN) response. To estimate the bioavailability of DF in the skin, MN responses at different times following initial DF application (1.5, 6, 24, 32, 48, 72, 96, and 120 hours) were analyzed. At 1.5 hours after the initial DF application, a significant decrease in MN response was detected for the occluded and iontophoretic delivery. Passive application resulted in a decrease of the MN response from 6 hours post-DF application. The inhibition remained up to 32 hours post-DF application for the iontophoretic delivery, 48 hours for the occluded application, and 72 hours for the passive delivery. At 96 and 120 hours post-DF application none of the MN responses was inhibited. The formation and emptying of a DF skin reservoir was found to be dependent on the DF-application mode. Penetration-enhanced delivery resulted in a faster emptying of the reservoir.

  19. In vivo determination of the diclofenac skin reservoir: comparison between passive, occlusive, and iontophoretic application

    Directory of Open Access Journals (Sweden)

    Clijsen R

    2015-02-01

    Full Text Available Ron Clijsen,1,2 Jean Pierre Baeyens,2 André Odilon Barel,2 Peter Clarys2 1Department of Health Sciences, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland; 2Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium Aim: There is scarce information concerning the pharmacodynamic behavior of topical substances used in the physiotherapy setting. The aim of the present study was to estimate the formation and emptying of the diclofenac (DF skin reservoir after passive, semiocclusive, and electrically assisted applications of DF.Subjects and methods: Five different groups of healthy volunteers (ntotal=60, 23 male and 37 female, participated in this study. A 1% DF (Voltaren Emulgel formulation (12 mg was applied on the volar forearms on randomized defined circular skin areas of 7 cm2. DF was applied for 20 minutes under three different conditions at the same time. The presence of DF in the skin results in a reduction of the methyl nicotinate (MN response. To estimate the bioavailability of DF in the skin, MN responses at different times following initial DF application (1.5, 6, 24, 32, 48, 72, 96, and 120 hours were analyzed.Results: At 1.5 hours after the initial DF application, a significant decrease in MN response was detected for the occluded and iontophoretic delivery. Passive application resulted in a decrease of the MN response from 6 hours post-DF application. The inhibition remained up to 32 hours post-DF application for the iontophoretic delivery, 48 hours for the occluded application, and 72 hours for the passive delivery. At 96 and 120 hours post-DF application none of the MN responses was inhibited.Conclusion: The formation and emptying of a DF skin reservoir was found to be dependent on the DF-application mode. Penetration-enhanced delivery resulted in a faster emptying of the reservoir. Keywords: transdermal drug delivery, passive diffusion, occlusion

  20. Ejection Fraction Heart Failure Measurement

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Ejection Fraction Heart Failure Measurement Updated:Feb 15,2017 The ejection fraction ( ... failure This content was last reviewed April 2015. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

  1. Implantable cardiac monitors in high-risk post-infarction patients with cardiac autonomic dysfunction and moderately reduced left ventricular ejection fraction: Design and rationale of the SMART-MI trial.

    Science.gov (United States)

    Hamm, Wolfgang; Rizas, Konstantinos D; Stülpnagel, Lukas von; Vdovin, Nikolay; Massberg, Steffen; Kääb, Stefan; Bauer, Axel

    2017-08-01

    Most deaths after myocardial infarction (MI) occur in patients with left ventricular ejection fraction (LVEF) >35%, for whom no specific prophylactic strategies exist. Deceleration capacity (DC) of heart rate and periodic repolarization dynamics (PRD) are noninvasive electrophysiological markers depending on the vagal and sympathetic tone. The combination of abnormal DC and/or PRD identifies a new high-risk group among postinfarction patients with LVEF 36%-50%. This new high-risk group has similar characteristics with respect to prognosis and patient numbers to those of the established high-risk group identified by LVEF ≤ 35%. The SMART-MI trial is an investigator-initiated randomized prospective multicenter trial that tests the efficacy of implantable cardiac monitors (ICM) in this new high-risk group. The study will enroll approximately 1,600 survivors of acute MI with sinus rhythm and an LVEF of 35%-50% in 17 centers in Germany who will be tested for presence of cardiac autonomic dysfunction. Four hundred patients with either abnormal DC (≤2.5 ms) and/or PRD (≥5.75deg(2)) will be randomized in a 1:1 fashion to intensive follow-up via telemonitoring using an ICM device (experimental arm) or conventional follow-up (control arm). For the ICM arm, specific treatment paths have been developed according to current guidelines. The primary end point is time to detection of predefined serious arrhythmic events during follow-up, including atrial fibrillation ≥6minutes, nonsustained ventricular tachycardia (cycle length≤320 ms; ≥40 beats), atrioventricular block ≥IIb, and sustained ventricular tachycardia/ventricular fibrillation. The median follow-up period is 18months with a minimum follow-up of 6months. The effect of remote monitoring on clinical outcomes will be tested as secondary outcome measure (ClinicalTrials.gov NCT02594488). Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Passive and iontophoretic transport enhancement of insulin through porcine epidermis by depilatories: Permeability and fourier transform infrared spectroscopy studies

    OpenAIRE

    Rastogi, Sumeet K.; Singh, Jagdish

    2003-01-01

    The effect of thioglycolate-based depilatory lotions was studied on the in vitro passive and iontophoretic permeability of insulin through porcine epidermis and biophysical changes in the stratum corneum (SC) lipids and proteins. The porcine epidermis and Franz diffusion cells modified for iontophoresis were used for the in vitro transport studies. Cathodal iontophoresis was performed at 0.2 mA/cm2 current density. Resistance of the control- and depilatory-lotion-treated epidermis was determi...

  3. Investigation of the ex vivo and in vivo iontophoretic delivery of aceclofenac from topical gels in Albino rats

    OpenAIRE

    Bhatt, Bhavik; Koland, Marina; Shama, K Prasanna

    2013-01-01

    Introduction: Iontophoresis was used to enhance the delivery of aceclofenac (ACF) from topical gels formulated with various polymers for the purpose of relieving pain and inflammation. Materials and Methods Gels were formulated from hydroxypropyl methyl cellulose (HPMC), carbopol 934P, and sodium carboxymethyl cellulose (NaCMC). The formulations were evaluated for cathodal iontophoretic delivery of ACF through excised rat abdominal skin at three levels of current density of 0.5, 0.6 and 0.7 m...

  4. Iontophoretic Delivery of Riboflavin into the Rabbit Cornea:a Primary Study

    Institute of Scientific and Technical Information of China (English)

    Na Li; Xiujun Peng; Zhengjun Fan; Yu Xia

    2014-01-01

    Purpose:.To determine the penetrability of riboflavin into the corneal stroma by iontophoresis and to compare the perme-ability effects of different solvents. Methods:.Twenty rabbits were randomly divided into four groups:.a group that received 0.1% riboflavin-balanced salt solution (BSS) by iontophoresis, a group that received 0.1%riboflavin-saline solution by iontophoresis,.a group that re-ceived 0.1% riboflavin-distilled water solution by iontophore-sis, and a control group that received classical riboflavin in-stillation after corneal de-epithelialization..The degree of yel-lowing of the de-epithelialized corneal stromal button from each rabbit was compared. Results:.The yellow color scores for the corneal stromal but-tons in the three iontophoresis groups were compared with those of control group..Iontophoretic delivery of a 0.1% ri-boflavin-distilled water solution yielded similar yellow changes in the corneal stromal button when compared with classical ri-boflavin instillation after de-epithelialization..However,.the other two solvents did not sufficiently enhance the permeabili-ty of riboflavin. Conclusion:.Riboflavin can effectively penetrate into the corneal stroma to saturation levels by iontophoresis..Using distilled water as the solvent can promote penetrability.. (Eye Science 2014; 29:30-35).

  5. NO Exchange for a Water Molecule Favorably Changes Iontophoretic Release of Ruthenium Complexes to the Skin

    Directory of Open Access Journals (Sweden)

    Danielle C. A. S. de Santana

    2017-01-01

    Full Text Available Ruthenium (Ru complexes have been studied as promising anticancer agents. Ru nitrosyl complex (Ru-NO is one which acts as a pro-drug for the release of nitric oxide (NO. The Ru-aqueous complex formed by the exchange of NO for a water molecule after NO release could also possess therapeutic effects. This study evaluates the influence of iontophoresis on enhancing the skin penetration of Ru-NO and Ru-aqueous and assesses its applicability as a tool in treating diverse skin diseases. Passive and iontophoretic (0.5 mA·cm−2 skin permeation of the complexes were performed for 4 h. The amount of Ru and NO in the stratum corneum (SC, viable epidermis (VE, and receptor solution was quantified while the influence of iontophoresis and irradiation on NO release from Ru-NO complex was also evaluated. Iontophoresis increased the amount of Ru-NO and Ru-aqueous recovered from the receptor solution by 15 and 400 times, respectively, as compared to passive permeation. Iontophoresis produced a higher accumulation of Ru-aqueous in the skin layers as compared to Ru-NO. At least 50% of Ru-NO penetrated the SC was stable after 4 h. The presence of Ru-NO in this skin layer suggests that further controlled release of NO can be achieved by photo-stimulation after iontophoresis.

  6. Coronal Mass Ejections: Observations

    Directory of Open Access Journals (Sweden)

    David F. Webb

    2012-06-01

    Full Text Available Solar eruptive phenomena embrace a variety of eruptions, including flares, solar energetic particles, and radio bursts. Since the vast majority of these are associated with the eruption, development, and evolution of coronal mass ejections (CMEs, we focus on CME observations in this review. CMEs are a key aspect of coronal and interplanetary dynamics. They inject large quantities of mass and magnetic flux into the heliosphere, causing major transient disturbances. CMEs can drive interplanetary shocks, a key source of solar energetic particles and are known to be the major contributor to severe space weather at the Earth. Studies over the past decade using the data sets from (among others the SOHO, TRACE, Wind, ACE, STEREO, and SDO spacecraft, along with ground-based instruments, have improved our knowledge of the origins and development of CMEs at the Sun and how they contribute to space weather at Earth. SOHO, launched in 1995, has provided us with almost continuous coverage of the solar corona over more than a complete solar cycle, and the heliospheric imagers SMEI (2003 – 2011 and the HIs (operating since early 2007 have provided us with the capability to image and track CMEs continually across the inner heliosphere. We review some key coronal properties of CMEs, their source regions and their propagation through the solar wind. The LASCO coronagraphs routinely observe CMEs launched along the Sun-Earth line as halo-like brightenings. STEREO also permits observing Earth-directed CMEs from three different viewpoints of increasing azimuthal separation, thereby enabling the estimation of their three-dimensional properties. These are important not only for space weather prediction purposes, but also for understanding the development and internal structure of CMEs since we view their source regions on the solar disk and can measure their in-situ characteristics along their axes. Included in our discussion of the recent developments in CME

  7. NON INVASIVE THERAPEUTIC DRUG MONITORING OF PROPRANOLOL HYDROCHLORIDE BY REVERSE IONTOPHORESIS

    Directory of Open Access Journals (Sweden)

    Saini Vipin

    2012-04-01

    Full Text Available Therapeutic drug monitoring (TDM is highly required for drugs possessing narrow therapeutic index as a slight variation in the therapeutic range could result in no or low clinical efficiency or causes significant side effects or high risk of toxicity. In recent days, reverse iontophoresis technique has been attempted for the non invasive drug monitoring. Typically, it applies a low electric current through a pair of skin electrodes to promote the transport of both charged and neutral molecules. Transdermal iontophoretic extraction of propranolol was carried out and the study involves effect of different solvents having their different pH values on the iontophoretic extraction, effect of different voltages on the iontophoretic extraction, effect of different permeation enhancers on the permeability of propranolol hydrochloride and the effect of stratum corneum removal on the permeability of propranolol. Iontophoretic diffusion was carried out in vitro using full thickness rat skin. The efficient quantity of propranolol was collected at cathode by electromigration. The correlation between the extracted fluxes of propranolol and its subdermal concentration was found to be adequate. The values of extraction fluxes didn’t attain a steady state throughout the experiment. The decrease in the solvent pH doesn’t affect the transdermal extraction of propranolol. The decrease in the voltage causes diminishes in the iontophoretic fluxes. The application of permeation enhancers especially propylene glycol causes significantly increase in the iontophoretic fluxes of propranolol. Thus it is concluded that propranolol hydrochloride can be quantitatively extracted by reverse iontophoresis in varying conditions of subdermal concentration.

  8. Determination of the in vivo bioavailability of iontophoretically delivered diclofenac using a methyl nicotinate skin inflammation assay.

    Science.gov (United States)

    Lambrecht, Renzo; Clarys, Peter; Clijsen, Ron; Barel, André O

    2006-08-01

    In this study, we investigated the bioavailability of iontophoretically delivered diclofenac with the methylnicotinate (MN) test. The inhibition of an erythema provoked by MN is proportional to the bioavailability of diclofenac in the skin. It was our aim to use this procedure in the determination of the contribution of, respectively, passive diffusion, occlusion and electrically assisted delivery during an iontophoretic procedure as used in physiotherapy. A total of six application sites were marked on the volar forearms of each volunteer (n=12), for the following treatment and/or control modes: A=cathodal iontophoresis of 12 mg/cm(2) Voltaren Emulgel (diethylammonii diclofenac 1%) for 20 min; B=passive diffusion under a contact sponge; C=passive diffusion without any covering; D=current alone; E=standard MN response; and F=blanco site. Tristimulus surface colorimetry and Laser Doppler flowmetry were used to measure, respectively, the skin color and the perfusion of the microcirculation. Bioavailability was assessed by quantification of an MN-induced erythema under the different conditions. A significant reduction of the MN-induced erythema was observed with the Chromameter and Laser Doppler measurements for the following treatment modalities: (1) electrically assisted delivery: respectively, 65% and 100%, (2) application under a contact sponge: 66% and 97% and (3) passive diffusion without any covering: 32% and 65%. A significant reduction was equally observed for the site treated with the current alone: 19% and 42%. There was no significant difference between the response after iontophoretic-delivered diclofenac (mode A) and application of diclofenac under a contact sponge (mode B). The procedure used enabled us to evaluate the bioavailability of a non-steroidal anti-inflammatory drug in the skin. Under the conditions used, we did not find an increased bioavailability after electrically assisted delivery of diclofenac compared with the passive percutaneous

  9. Sumatriptan transdermal iontophoretic patch (NP101-Zelrix™: review of pharmacology, clinical efficacy, and safety in the acute treatment of migraine

    Directory of Open Access Journals (Sweden)

    Vikelis M

    2012-09-01

    Full Text Available Michail Vikelis,1 Dimos D Mitsikostas,2 Alan M Rapoport31Glyfada Headache Center, Glyfada, Greece; 2Neurology Department, Athens Naval Hospital, Athens, Greece; 3The David Geffen School of Medicine at UCLA, Los Angeles, CA, USAAbstract: Migraine is a chronic, painful, and often disabling primary headache disorder, typically presenting with recurrent attacks that may be accompanied by a variety of neurological, gastrointestinal, and autonomic symptoms. Gastrointestinal symptoms in association with migraine including, nausea, vomiting, and gastroparesis, affect a large proportion of migraine sufferers. These symptoms may result in delays or inconsistencies in the absorption of oral treatments. Hence, the necessity for an innovative, non-invasive, parenteral delivery formulation for quick and effective treatment of migraine attacks is evident. Iontophoresis utilizes minimal amounts of electrical potential to support the fast transfer of ionized medication transdermally and into the general circulation. Two pharmacokinetic clinical trials have shown that iontophoretic delivery of sumatriptan through the skin produces quick and reproducible therapeutic plasma concentrations. A randomized, double-blind, multicenter, phase III study demonstrated superior efficacy versus placebo and excellent tolerability, with no triptan-related adverse events. The proportion of patients that were pain-free at 2 h post-treatment was 18% for the sumatriptan patch vs 9% for placebo (P = 0.0092; number needed to treat = 11.1. Upon approval from the Food and Drug Administration and other regulatory authorities, the iontophoretic transdermal delivery of sumatriptan will be a good choice for patients experiencing poor absorption of oral medication often associated with migraine and/or for those with intolerable triptan-related adverse events.Keywords: iontophoretic patch, migraine, migraine treatment, sumatriptan, transdermal patch

  10. Topical gene silencing by iontophoretic delivery of an antisense oligonucleotide-dendrimer nanocomplex: the proof of concept in a skin cancer mouse model

    Science.gov (United States)

    Venuganti, , Venkata Vamsi K.; Saraswathy, Manju; Dwivedi, Chandradhar; Kaushik, Radhey S.; Perumal, Omathanu P.

    2015-02-01

    The study was aimed at investigating the feasibility of using a poly (amidoamine) (PAMAM) dendrimer as a carrier for topical iontophoretic delivery of an antisense oligonucleotide (ASO). Bcl-2, an anti-apoptotic protein implicated in skin cancer, was used as the model target protein to demonstrate the topical gene silencing approach. Confocal laser scanning microscopy studies demonstrated that the iontophoretically delivered ASO-dendrimer complex can reach the viable epidermis in porcine skin. In contrast, passively delivered free or dendrimer complexed ASO was mainly localized to the stratum corneum. The cell uptake of ASO was significantly enhanced by the dendrimer complex and the complex suppressed Bcl-2 levels in the cell. In the skin cancer mouse model, the iontophoretically delivered ASO-dendrimer complex reduced the tumor volume by 45% and was consistent with the reduction in Bcl-2 protein levels. The iontophoretically delivered ASO-dendrimer complex caused significant apoptosis in skin tumor. Overall, the findings from this study demonstrate that dendrimers are promising nanocarriers for developing topical gene silencing approaches for skin diseases.The study was aimed at investigating the feasibility of using a poly (amidoamine) (PAMAM) dendrimer as a carrier for topical iontophoretic delivery of an antisense oligonucleotide (ASO). Bcl-2, an anti-apoptotic protein implicated in skin cancer, was used as the model target protein to demonstrate the topical gene silencing approach. Confocal laser scanning microscopy studies demonstrated that the iontophoretically delivered ASO-dendrimer complex can reach the viable epidermis in porcine skin. In contrast, passively delivered free or dendrimer complexed ASO was mainly localized to the stratum corneum. The cell uptake of ASO was significantly enhanced by the dendrimer complex and the complex suppressed Bcl-2 levels in the cell. In the skin cancer mouse model, the iontophoretically delivered ASO-dendrimer complex

  11. Topical iontophoretic delivery of ionizable, biolabile aciclovir prodrugs: A rational approach to improve cutaneous bioavailability.

    Science.gov (United States)

    Chen, Yong; Alberti, Ingo; Kalia, Yogeshvar N

    2016-02-01

    The objective was to investigate the topical iontophoretic delivery of a series of amino acid ester prodrugs of aciclovir (ACV-X, where ACV=aciclovir and X=Arg, Gly, Ile, Phe, Trp and Val) as a means to enhance cutaneous delivery of ACV. The newly synthesized prodrugs were characterized by (1)H NMR and high resolution mass spectrometry. Analytical methods using HPLC-UV were developed for their quantification and each method was validated. Investigation of solution stability as a function of pH showed that all ACV-X prodrugs were relatively stable in acid conditions at pH 2.0 and pH 5.5 for up to 8h but susceptible to extensive hydrolysis at pH 7.4 and under alkaline conditions (pH 10). No ACV-X hydrolysis was observed after contact for 2h with the external surface of porcine stratum corneum. However, there was significant hydrolysis following contact with the dermal surface of dermatomed porcine skin, in particular, for ACV-Arg. Passive transport of ACV and ACV-X prodrugs from aqueous solution after 2h was below the limit of detection. Iontophoresis of ACV at 0.5 mA/cm(2) for 2h led to modest ACV skin deposition (QDEP,ACV) of 4.6 ± 0.3 nmol/cm(2). In contrast, iontophoresis of ACV-X prodrugs under the same conditions produced order of magnitude increases in cutaneous deposition of ACV species, that is, QDEP,TOTAL=QDEP,ACV+QDEP,ACV-X. QDEP,TOTAL for ACV-Gly, ACV-Val, ACV-Ile, ACV-Phe, ACV-Trp and ACV-Arg was 412.8 ± 44.0, 358.8 ± 66.8, 434.1 ± 68.2, 249.8 ± 81.4, 156.1 ± 76.3, 785.9 ± 78.1 nmol/cm(2), respectively. The extent of bioconversion of ACV-X to ACV in the skin was high and the proportion of ACV present ranged from 81% to 100%. The skin retention ratio, a measure of the selectivity of ACV species for deposition over permeation after iontophoretic delivery of ACV-X prodrugs, was dependent on both the rate of transport and the susceptibility to hydrolysis of the prodrugs. Skin deposition of ACV and its six prodrugs were investigated further as a

  12. Coronal Mass Ejections An Introduction

    CERN Document Server

    Howard, Timothy

    2011-01-01

    In times of growing technological sophistication and of our dependence on electronic technology, we are all affected by space weather. In its most extreme form, space weather can disrupt communications, damage and destroy spacecraft and power stations, and increase radiation exposure to astronauts and airline passengers. Major space weather events, called geomagnetic storms, are large disruptions in the Earth’s magnetic field brought about by the arrival of enormous magnetized plasma clouds from the Sun. Coronal mass ejections (CMEs) contain billions of tons of plasma and hurtle through space at speeds of several million miles per hour. Understanding coronal mass ejections and their impact on the Earth is of great interest to both the scientific and technological communities. This book provides an introduction to coronal mass ejections, including a history of their observation and scientific revelations, instruments and theory behind their detection and measurement, and the status quo of theories describing...

  13. Impact of early, late, and no ST-segment resolution measured by continuous ST Holter monitoring on left ventricular ejection fraction and infarct size as determined by cardiovascular magnetic resonance imaging

    NARCIS (Netherlands)

    J.D.E. Haeck; N.J.W. Verouden; W.J. Kuijt; K.T. Koch; M. Majidi; A. Hirsch; J.G.P. Tijssen; M.W. Krucoff; R.J. de Winter

    2011-01-01

    Background: The goal of this study is to determine the predictive value of ST-segment resolution (STR) early after percutaneous coronary intervention (PCI), late STR, and no STR for left ventricular ejection fraction (LVEF) and infarct size (IS) by cardiovascular magnetic resonance (CMR) at follow-u

  14. The beam diagnostic system, serving the Serpukhov fast ejection

    CERN Document Server

    Cupérus, J; Kamber, I; Nuttall, J

    1973-01-01

    A set of beam transformers measures the intensity of each bunch, circulating or ejected. Five electrostatic pick-ups measure the radial position of one selected bunch. Secondary emission grids and luminescent screens give the profile and position of the beam at relevant points. Gated radiation detectors monitor beam loss in the ejection area. All signals are digitalized and fed to a minicomputer on line. Readout is via nixies, CRT analogue displays, pen recorders and a teletype. Statistics can be made over a chosen number of acceleration cycles. (5 refs).

  15. PS, septum magnet for ejection of antiprotons

    CERN Multimedia

    1980-01-01

    Antiprotons circulated in the PS in the sense opposite to that of the so far normal protons (or positive ions). A new ejection system with a new septum magnet was installed in straight section 58 for antiproton ejection, first towards the ISR and then to the principal customer, the SPS p-pbar Collider. Later on, when the PS delivered leptons for LEP, the antiproton ejection system was use for the ejection of electrons.

  16. Coronal Mass Ejections travel time

    Science.gov (United States)

    Braga, Carlos Roberto; Souza de Mendonça, Rafael Rodrigues; Dal Lago, Alisson; Echer, Ezequiel

    2017-10-01

    Coronal mass ejections (CMEs) are the main source of intense geomagnetic storms when they are earthward directed. Studying their travel time is a key-point to understand when the disturbance will be observed at Earth. In this work, we study the CME that originated the interplanetary disturbance observed on 2013/10/02. According to the observations, the CME that caused the interplanetary disturbance was ejected on 2013/09/29. We obtained the CME speed and estimate of the time of arrival at the Lagrangian Point L1 using the concept of expansion speed. We found that observed and estimated times of arrival of the shock differ between 2 and 23 hours depending on method used to estimate the radial speed.

  17. Development of the fentanyl iontophoretic transdermal system (ITS) for patient-controlled analgesia of postoperative pain management.

    Science.gov (United States)

    Minkowitz, Harold S; Danesi, Hassan; Ding, Li; Jones, James B

    2015-09-01

    The fentanyl iontophoretic transdermal system (ITS) is a needle-free, patient-activated drug delivery system used for patient-controlled analgesia in adult hospitalized patients with postoperative pain. The system design has been updated to a separated system consisting of a Controller and a Drug Unit, and has had regulatory submissions in USA and Europe in 2014. Fentanyl ITS has been shown to be therapeutically equivalent to morphine intravenous (iv.) patient-controlled analgesia. One of the advantages of fentanyl ITS is that patients have better mobility as there is no need for an iv. pump, iv. lines and pole. The introduction of the updated fentanyl ITS will add a versatile tool to the postoperative pain management armamentarium.

  18. Transdermal iontophoretic delivery of tacrine hydrochloride: Correlation between in vitro permeation and in vivo performance in rats.

    Science.gov (United States)

    Patel, Niketkumar; Jain, Shashank; Lin, Senshang

    2016-11-20

    The aim of present investigation is to evaluate the feasibility of transdermal iontophoretic delivery of tacrine hydrochloride in Sprague Dawley (SD) rats using anodal iontophoretic patches and to correlate plasma tacrine concentration profiles to in vitro tacrine permeation flux. In vitro skin permeation studies were carried out across artificial membrane CELGRAD(®) 2400, freshly excised SD rat abdominal skin, freshly excised hairless rat abdominal skin, and frozen pig skin to examine the role of permeation membranes. Furthermore, plasma profiles with an application of 0.1-0.3mA current strength and tacrine concentration loading of 5-20mg/ml were obtained in SD rats. The tacrine plasma profiles were fitted to one-compartmental model using WinNonlin and in vivo transdermal absorption rates were then correlated to in vitro permeation profiles using various approaches. Tacrine permeation across membranes revealed current dependent interspecies differences at lower current strength application which diminished at higher current strength application, whereas, no significant difference in tacrine permeation was observed across fresh and frozen SD rat skin under 0.2mA current application. In vivo studies confirmed current and concentration dependent tacrine plasma profiles with possible tacrine depot formation under the skin in-line with earlier in vitro results. Correlation of in vivo transdermal absorption rates to in vitro permeation profiles revealed higher in vitro permeation fluxes compare to in vivo transdermal absorption rates at varied combination of current strength and concentrations. Present in vivo studies support the earlier published in vitro findings and tacrine plasma profiles show a potential to reach therapeutic effective concentration of tacrine hydrochloride to provide a platform for pre-programmed tacrine delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Transdermal Iontophoretic Delivery of Atenolol in Combination with Penetration Enhancers: Optimization and Evaluation on Solution and Gels

    Directory of Open Access Journals (Sweden)

    Nandy B. C.

    2009-07-01

    Full Text Available In the present investigation, we prepared Atenolol (1.5 % w/w solution and various polymer formulations by incorporating the tween-20 or L-menthol, as a penetration enhancers and its effect on permeation of the drug through the excised abdominal rat skin were used to examined by using the vertical Franz-type diffusion cell. The physicochemical interactions between Atenolol and various polymers were investigated by performing the assay, ultra violet absorption maxima, Fourier transform infrared spectroscopy and it was further confirmed by thin layer chromatography studies, from which drug did not show any evidence of interaction with the polymers. We found that, L-menthol was superior than tween-20 to iontophoresis [current density applied 0.5 mA/cm2 and 90:10 (on: off ratio], in enhancing the transdermal permeation of Atenolol; it enhanced the flux of Atenolol by more than 2-folds, comparison to the preparations without penetration enhancer via passive diffusion, and 3 folds increased using iontophoresis alone with a shorter lag time. Atenolol also showed good stability in gel formulations. The basic parameters like % loading dose released at the end of the study, permeation coefficient and steady state flux (Jss were calculated and showed statistically significant difference (p<0.05. The results indicated that suitable iontophoretic delivery with desired permeability could be appeared and the cumulative amount-time curves were suitable to fit by a zero order equations which indicated a steady state permeation rate or sustained effect could be achieved from hydrogel; when it is combined with penetration enhancer, L-menthol. The results demonstrate that the semisolid gel formulations are more applicable than solution as a transdermal iontophoretic delivery system to administer clinically. Electrically assisted transdermal delivery of Atenolol significantly increased transport compared to passive delivery. Also, rapid and modulated delivery was

  20. Coronal Mass Ejections and Non-recurrent Forbush Decreases

    Science.gov (United States)

    Belov, A.; Abunin, A.; Abunina, M.; Eroshenko, E.; Oleneva, V.; Yanke, V.; Papaioannou, A.; Mavromichalaki, H.; Gopalswamy, N.; Yashiro, S.

    2014-10-01

    Coronal mass ejections (CMEs) and their interplanetary counterparts (interplanetary coronal mass ejections, ICMEs) are responsible for large solar energetic particle events and severe geomagnetic storms. They can modulate the intensity of Galactic cosmic rays, resulting in non-recurrent Forbush decreases (FDs). We investigate the connection between CME manifestations and FDs. We used specially processed data from the worldwide neutron monitor network to pinpoint the characteristics of the recorded FDs together with CME-related data from the detailed online catalog based upon the Solar and Heliospheric Observatory (SOHO)/ Large Angle and Spectrometric Coronagraph (LASCO) data. We report on the correlations of the FD magnitude to the CME initial speed, the ICME transit speed, and the maximum solar wind speed. Comparisons between the features of CMEs (mass, width, velocity) and the characteristics of FDs are also discussed. FD features for halo, partial halo, and non-halo CMEs are presented and discussed.

  1. Characteristics of Coronal Mass Ejections

    Science.gov (United States)

    Talukder, F.; Marchese, A. K.; Tulsee, T.

    2014-12-01

    A coronal mass ejection (CME) is a release of charged particles resulting from solar activity. These charged particles can affect electronics on spacecraft, airplanes, global positioning systems, and communication satellites. The purpose of this research was to study CME data from satellites and correlate these to other properties. Solar wind data collected by STEREO A/B and ACE satellites were analyzed. The data consisted of solar wind flux for various elements (helium through iron), as well as the components of the interplanetary magnetic field. CME events are known to cause a surge in the helium flux, as well as other particles. It is hypothesized that a CME event will cause an increase in the number of lighter elements relative to heavier particles. This is because for a given input of energy, lighter elements are expected to be accelerated to a greater extent than heavier elements. A significant increase was observed in the ratio between helium to oxygen (He/O) prior to intense CMEs. A CME event on November 4, 2003 caused an eleven-fold increase in the He/O ratio, while for another event on April 2, 2001 the He/O ratio increased from 80 to 700. A significant increase in He/O ratio is not observed during weaker CMEs. Furthermore, it was also observed that not all increases in the ratio were accompanied by CMEs. The increase in He/O ratio prior to the CME arrival might be used as a way to predict future events.

  2. The Accretion Flow - Discrete Ejection Connection in GRS 1915+105

    CERN Document Server

    Punsly, Brian; Trushkin, Sergei A

    2016-01-01

    The microquasar GRS~1915+105 is known for its spectacular discrete ejections. They occur unexpectedly, thus their inception escapes direct observation. It has been shown that the X-ray flux increases in the hours leading up to a major ejection. In this article, we consider the serendipitous interferometric monitoring of a modest version of a discrete ejection described in Reid et al. (2014) that would have otherwise escaped detection in daily radio light curves. The observation begins $\\sim 1$ hour after the onset of the ejection, providing unprecedented accuracy on the estimate of the ejection time. The astrometric measurements allow us to determine the time of ejection as $\\rm{MJD}\\, 56436.274^{+0.016}_{-0.013}$, i.e., within a precision of 41 minutes (95\\% confidence). Just like larger flares, we find that the X-ray luminosity increases in last 2 - 4 hours preceding ejection. Our finite temporal resolution indicates that this elevated X-ray flux persists within $21.8^{+22.6}_{-19.1}$ minutes of the ejectio...

  3. Water versus salty taste and Iontophoretic ANGII responses of septopreoptic neurons in dehydrated and euhydrated awake rats.

    Science.gov (United States)

    Mousseau, M C; Thornton, S N; Liénard, F; Martial, F P; Nicolaïdis, S

    1996-01-01

    Little is known of the influence of gustatory, particularly salt, input on neurons of the forebrain and if the same neurons are sensitive to hydromineral balance humoral stimuli. In awake, nonpremedicated rats we recorded the activity of spontaneously active neurons in the preoptic/anterior hypothalamic area of dehydrated and euhydrated rats while allowing them to ingest water or a hypertonic salt solution (1.6% NaCl) administered to the tongue. The hormones angiotensin and aldosterone, both implicated in hydromineral balance, were applied by iontophoresis to the same neurons. In the dehydrated rats, 27% (15/55) of the spontaneously active neurons responded to a liquid (either water or the NaCl) applied to the tongue; in the euhydrated rats 23% (18/78) responded to the same stimuli. In the dehydrated rats, however, 33% (5/15) of the responding neurons were inhibited when the NaCl solution was applied to the tongue compared with only 5% (1/18) in the euhydrated rats. Iontophoretic application of angiotensin increased the spontaneous activity in 21% of those neurons tested that responded to taste. These results suggest that the state of hydration of an animal is able to change the neuronal response to substances applied to the tongue. Furthermore, it appears that these gustatory-sensitive neurons may also be related to hydromineral balance regulation since they are able to respond to angiotensin.

  4. Space weather and coronal mass ejections

    CERN Document Server

    Howard, Tim

    2013-01-01

    Space weather has attracted a lot of attention in recent times. Severe space weather can disrupt spacecraft, and on Earth can be the cause of power outages and power station failure. It also presents a radiation hazard for airline passengers and astronauts. These ""magnetic storms"" are most commonly caused by coronal mass ejections, or CMES, which are large eruptions of plasma and magnetic field from the Sun that can reach speeds of several thousand km/s. In this SpringerBrief, Space Weather and Coronal Mass Ejections, author Timothy Howard briefly introduces the coronal mass ejection, its sc

  5. AD Ejection Line Studies and Optics Improvements

    CERN Document Server

    Belochitskii, P

    2013-01-01

    This paper is a summary of the work we made to understand and improve the AD ejection line optics. In 2011 significant differences were noticed between the optical properties of the AD ejection line and the MAD model. Investigations started to find out the sources of discrepancy. Better understanding of the ejection line optics was obtained and corrections were applied to the model of ejection line. The beam delivery to the experiments is better understood now. The results obtained might be useful as well for the optics design of AD to ELENA transfer line. Potential problems with the fringing field model in MAD were pointed out, when bending magnets with large bending angles and small bending radius are involved.

  6. CFD Simulations of Vibration Induced Droplet Ejection.

    Science.gov (United States)

    James, Ashley; Smith, Marc K.; Glezer, Ari

    1998-11-01

    Vibration-induced droplet ejection is a process that occurs when a liquid droplet is placed on a vibrating membrane. Above a critical value of the excitation amplitude, Faraday waves form on the surface of the drop. As the amplitude is increased secondary drops are ejected from the wave crests. A Navier-Stokes solver designed to simulate the transient fluid mechanics of the process is presented. The solver is based on a MAC method on a staggered grid. A volume of fluid method is implemented to track the free surface. The volume fraction is advected via a second-order, unsplit method that minimizes numerical diffusion of the interface. Surface tension is incorporated as a continuum surface force. This work is intended to provide a comprehensive description of the fluid dynamics involved in vibration-induced droplet ejection, with the aim of understanding the mechanism behind the ejection process. The evolution of the interface through droplet ejection will be simulated. The dependence of the ejection process on the driving parameters will be evaluated and the resonance characteristics of the drop will be determined. The results of the computations will be compared with experimental results.

  7. Progress in research of iontophoretic delivery systems%离子电渗给药技术的研究进展

    Institute of Scientific and Technical Information of China (English)

    李丁; 程志红; 吴闻哲

    2011-01-01

    Iontophoresis as a non-invasive technique has been investigated for many years. Significant achievements have been made in the understanding of mechanisms underlying iontophoresis, which have contributed to the rational development of iontophoretic delivery systems. The application of a small electric current has enhanced the transport of charged, polar, and neutral compounds across the body. The principal distinguishing feature is the control afforded by iontophoresis and the ability to individualize therapies. This may become significant impact on interindividual variations in protein expression, and may be beneficial to drug metabolism and improvement of drug efficacy. This review focused on the progress in research of iontophoretic delivery systems, factors influencing iontophoretic process, new administration routes and conjunction with other enhancing technologies.%离子电渗技术作为一种非侵袭性给药方法已经研究了很多年,其作用机制已经广为人们所熟知并以此推动离子电渗给药系统的发展.该技术利用微量电流帮助解离、极性和中性药物分子透过机体屏障.它能够根据患者的自身情况调整治疗方案,这可以减少治疗时蛋白类药物的个体差异,影响药物代谢,进而提高治疗效果.本文综述了近年来离子电渗给药技术的研究进展、影响因素、新的给药途径以及与其他促渗技术的联合应用.

  8. Synergistic iontophoretic drug delivery of risedronate sodium in combination with electroporation and chemical penetration enhancer: In-vitro and in-vivo evaluation

    Directory of Open Access Journals (Sweden)

    Swaroop R Lahoti

    2015-01-01

    Full Text Available In the present investigation iontophoretic permeation of risedronate sodium (RS through optimized gel based formulation was evaluated with respect to various electrical parameters like Current density and type of current. The study also involved enhancement the iontophoretic permeation of RS in combination with electroporation and chemical penetration enhancers with its in-vivo Pharmacokinetic evaluation. The permeation studies were carried through the human cadaver skin by using modified Franz diffusion cell and microcontroller based devices for iontophoresis and electroporation developed in the laboratory. In-vivo Pharmacokinetic studies were carried out in hairless rats. One way ANOVA followed by Tukey-Kramer test for multiple comparisons. The permeation of RS was significantly increased with iontophoresis at 0.5 mA/Cm 2 current density. The iontophoretic permeation was found depend on current density and ON:OFF ratio. The pulsatile current resulted in high permeation than continuous current. Maximum permeation was obtained at 0.5 mA/cm 2 with 1:1 pulsed current. When iontophoresis was coupled with chemical penetration enhancers and electroporation for 100 ms at 220V, synergistic enhancement in permeation was observed with shortened lag time and high flux. The required flux was achieved with area of application 1.55 cm 2 . In-vivo studies in hairless rats revealed high C max, low t max and increased area under the curve with electroporation, followed by iontophoresis indicated increased bioavailability. Relative bio-availability was 4.6 when calculated in comparison to passive studies.

  9. Numerical Simulations of a Flux Rope Ejection

    Indian Academy of Sciences (India)

    P. Pagano; D. H. Mackay; S. Poedts

    2015-03-01

    Coronal mass ejections (CMEs) are the most violent phenomena observed on the Sun. One of the most successful models to explain CMEs is the flux rope ejection model, where a magnetic flux rope is expelled from the solar corona after a long phase along which the flux rope stays in equilibrium while magnetic energy is being accumulated. However, still many questions are outstanding on the detailed mechanism of the ejection and observations continuously provide new data to interpret and put in the context. Currently, extreme ultraviolet (EUV) images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) are providing new insights into the early phase of CME evolution. In particular, observations show the ejection of magnetic flux ropes from the solar corona and how they evolve into CMEs. However, these observations are difficult to interpret in terms of basic physical mechanisms and quantities, thus, we need to compare equivalent quantities to test and improve our models. In our work, we intend to bridge the gap between models and observations with our model of flux rope ejection where we consistently describe the full life span of a flux rope from its formation to ejection. This is done by coupling the global non-linear force-free model (GNLFFF) built to describe the slow low- formation phase, with a full MHD simulation run with the software MPI-AMRVAC, suitable to describe the fast MHD evolution of the flux rope ejection that happens in a heterogeneous regime. We also explore the parameter space to identify the conditions upon which the ejection is favoured (gravity stratification and magnetic field intensity) and we produce synthesised AIA observations (171 Å and 211 Å). To carry this out, we run 3D MHD simulation in spherical coordinates where we include the role of thermal conduction and radiative losses, both of which are important for determining the temperature distribution of the solar corona during a CME. Our model of flux

  10. Proton ejection project for Saturne; Projet d'ejection des protons de saturne

    Energy Technology Data Exchange (ETDEWEB)

    Bronca, G.; Gendreau, G

    1959-07-01

    The reasons for choosing the ejection system are given. The characteristics required for the ejected beam are followed by a description of the ejection process, in chronological order from the viewpoint of the protons: movement of the particles, taking into account the various elements which make up the system (internal magnet, external magnet, quadrupoles, ejection correction coils, thin and thick cables,...) and specification of these elements. Then follows an estimation of the delay in manufacture and the cost of the project. Finally, the characteristics of the magnets and quadrupoles are listed in an appendix. (author) [French] On donne d'abord les raisons du choix du systeme d'ejection, puis le principe. Apres les caracteristiques requises pour le faisceau ejecte, on decrit le processus d'ejection selon l'ordre chronologique vu par les protons: mouvement des particules compte tenu des divers elements composant le systeme (aimant interne, aimant externe, quadrupoles, enroulements correcteurs ejection, cibles mince et epaisse,. ..) et cahier de charge de ces elements. On estime, ensuite les delais de realisation et le cout du projet. Enfin, un resume des caracteristiques des aimants et quadrupoles est donne en appendice. (auteur)

  11. Awake craniotomy in a patient with ejection fraction of 10%: considerations of cerebrovascular and cardiovascular physiology.

    Science.gov (United States)

    Meng, Lingzhong; Weston, Stephen D; Chang, Edward F; Gelb, Adrian W

    2015-05-01

    A 37-year-old man with nonischemic 4-chamber dilated cardiomyopathy and low-output cardiac failure (estimated ejection fraction of 10%) underwent awake craniotomy for a low-grade oligodendroglioma resection under monitored anesthesia care. The cerebrovascular and cardiovascular physiologic challenges and our management of this patient are discussed.

  12. Runaway Massive Binaries and Cluster Ejection Scenarios

    CERN Document Server

    McSwain, M V; Boyajian, T S; Grundstrom, E D; Roberts, M S E; Ransom, Scott M.; Boyajian, Tabetha S.; Grundstrom, Erika D.

    2006-01-01

    The production of runaway massive binaries offers key insights into the evolution of close binary stars and open clusters. The stars HD 14633 and HD 15137 are rare examples of such runaway systems, and in this work we investigate the mechanism by which they were ejected from their parent open cluster, NGC 654. We discuss observational characteristics that can be used to distinguish supernova ejected systems from those ejected by dynamical interactions, and we present the results of a new radio pulsar search of these systems as well as estimates of their predicted X-ray flux assuming that each binary contains a compact object. Since neither pulsars nor X-ray emission are observed in these systems, we cannot conclude that these binaries contain compact companions. We also consider whether they may have been ejected by dynamical interactions in the dense environment where they formed, and our simulations of four-body interactions suggest that a dynamical origin is possible but unlikely. We recommend further X-ra...

  13. Coronal Mass Ejections, Interplanetary Shocks In Relation With Forbush Decreases Associated With Intense Geomagnetic Storms

    Science.gov (United States)

    Verma, P. L.; Patel, Nand Kumar; Prajapati, Mateswari

    2014-05-01

    Coronal mass ejections (CMEs} are the most energetic solar events in which large amount of solar plasma materials are ejected from the sun into heliosphere, causing major disturbances in solar wind plasma, Interplanetary shocks, Forbush decrease(Fds) in cosmic ray intensity and geomagnetic storms. We have studied Forbush decreases associated with intense geomagnetic storms observed at Oulu super neutron monitor, during the period of May 1998-Dec 2006 with coronal mass ejections (CMEs), X-ray solar flares and interplanetary shocks. We have found that all the (100%) Forbush decreases associated with intense geomagnetic storms are associated with halo and partial halo coronal mass ejections (CMEs). The association rate between halo and partial halo coronal mass ejections are found 96.00%and 04.00% respectively. Most of the Forbush decreases associated with intense geomagnetic storms (96.29%) are associated with X-ray solar flares of different categories . The association rates for X-Class, M-Class, and C- Class X -ray solar flares are found 34.62%, 50.00% and 15.38% respectively .Further we have concluded that majority of the Forbush decrease associated with intense geomagnetic storms are related to interplanetary shocks (92.30 %) and the related shocks are forward shocks. We have found positive co-relation with co-relation co-efficient .7025 between magnitudes of Forbush decreases associated with intense geomagnetic storms and speed of associated coronal mass ejections. Positive co-relation with co-relation co-efficient 0.48 has also been found between magnitudes of intense geomagnetic storms and speed of associated coronal mass ejections.

  14. Forbush decreases associated to Stealth Coronal Mass Ejections

    Science.gov (United States)

    Heber, B.; Wallmann, C.; Galsdorf, D.; Herbst K.; Kühl, P.; Dumbovic, M.; Vršnak, B.; Veronig, A.; Temmer, M.; Möstl, C.; Dalla, S.

    Interplanetary coronal mass ejections (ICMEs) are structures in the solar wind that are the counterparts of coronal mass ejections (CMEs) at the Sun. It is commonly believed that enhanced magnetic fields in interplanetary shocks and solar ejecta as well as the increased turbulence in the solar wind sheath region are the cause of Forbush decreases (FDs) representing decreases of galactic cosmic ray (GCR) intensities. Recently, stealth CMEs i.e.~CMEs with no apparent solar surface association have become a subject in recent studies of solar activity. Whether all of such stealth CMEs can drive a FD is difficult to investigate on the basis of neutron monitor NM measurements because these measurements not only reflect the GCR intensity variation in interplanetary space but also the variation of the geomagnetic field as well as the conditions in the Earth atmosphere. Single detector counter from spacecraft instrumentation, here SOHO and Chandra EPHIN, exceed counting statistic of NMs allowing to determine intensity variation of less than 1 permil in interplanetary space on the basis of 30 minute count rate averages. Here we present the ongoing analysis of eleven stealth CMEs.

  15. Pilot ejection, parachute, and helicopter crash injuries.

    Science.gov (United States)

    McBratney, Colleen M; Rush, Stephen; Kharod, Chetan U

    2014-01-01

    USAF Pararescuemen (PJs) respond to downed aircrew as a fundamental mission for personnel recovery (PR), one of the Air Force's core functions. In addition to responding to these in Military settings, the PJs from the 212 Rescue Squadron routinely respond to small plane crashes in remote regions of Alaska. While there is a paucity of information on the latter, there have been articles detailing injuries sustained from helicopter crashes and while ejecting or parachuting from fixed wing aircraft. The following represents a new chapter added to the Pararescue Medical Operations Handbook, Sixth Edition (2014, editors Matt Wolf, MD, and Stephen Rush, MD, in press). It was designed to be a quick reference for PJs and their Special Operations flight surgeons to help with understanding of mechanism of injury with regard to pilot ejection, parachute, and helicopter accident injuries. It outlines the nature of the injuries sustained in such mishaps and provides an epidemiologic framework from which to approach the problem. 2014.

  16. Coronal Mass Ejections of Solar Cycle 23

    Indian Academy of Sciences (India)

    Nat Gopalswamy

    2006-06-01

    I summarize the statistical, physical, and morphological properties of coronal mass ejections (CMEs) of solar cycle 23, as observed by the Solar and Heliospheric Observatory (SOHO) mission. The SOHO data is by far the most extensive data, which made it possible to fully establish the properties of CMEs as a phenomenon of utmost importance to Sun–Earth connection as well as to the heliosphere. I also discuss various subsets of CMEs that are of primary importance for their impact on Earth.

  17. Observational Properties of Coronal Mass Ejections

    Science.gov (United States)

    2006-01-01

    2003. Peameis, D.V., Magntetic topology of imspumlsive assd gradutal solar energetic particle Xic. H., L. Ofmran, and G. Lawvrence, Cone model for...425, 1097, 2004. Yashiro, S., N. Gopalssvamy, G. Michalek, assd R.A. Hosvard, Properties of narrow coronal Sltatstnigara~jU, A., Y.-i. Mootn, M. Dryer...G.M.,’FTit relatiomtslip hetwseen prominence ermtptions assd coronal mnass ejections.. 107(A8), 1223, doi: 10. 1029/2001 JAOO9 143, 2002. .1. Atssnn.s

  18. Potential Method of Predicting Coronal Mass Ejection

    Science.gov (United States)

    Imholt, Timothy

    2001-10-01

    Coronal Mass Ejections (CME) may be described as a blast of gas and highly charged solar mass fragments ejected into space. These ejections, when directed toward Earth, have many different effects on terrestrial systems ranging from the Aurora Borealis to changes in wireless communication. The early prediction of these solar events cannot be overlooked. There are several models currently accepted and utilized to predict these events, however, with earlier prediction of both the event and the location on the sun where the event occurs allows us to have earlier warnings as to when they will affect man-made systems. A better prediction could perhaps be achieved by utilizing low angular resolution radio telescope arrays to catalog data from the sun at different radio frequencies on a regular basis. Once this data is cataloged a better predictor for these CME’s could be found. We propose a model that allows a prediction to be made that appears to be longer than 24 hours.

  19. Spontaneous Capillarity-Driven Droplet Ejection

    CERN Document Server

    Wollman, Andrew; Pettit, Donald; Weislogel, Mark

    2012-01-01

    The first large length-scale capillary rise experiments were conducted by R. Siegel using a drop tower at NASA LeRC shortly after the 1957 launch of Sputnik I. Siegel was curious if the wetting fluid would expel from the end of short capillary tubes in a low-gravity environment. He observed that although the fluid partially left the tubes, it was always pulled back by surface tension, which caused the fluid to remain pinned to the tubes' end. By exploiting tube geometry and fluid properties, we demonstrate that such capillary flows can in fact eject a variety of jets and drops. This fluid dynamics video provides a historical overview of such spontaneous capillarity-driven droplet ejection. Footage of terrestrial and low earth orbit experiments are also shown. Droplets generated in a microgravity environment are $10^6$ times larger than those ejected in a terrestrial environment. The accompanying article provides a summary of the critical parameters and experimental procedures. Scaling the governing equations ...

  20. Gas Ejection from Spiral Galaxy Disks

    Science.gov (United States)

    Durelle, Jeremy

    We present the results of three proposed mechanisms for ejection of gas from a spiral arm into the halo. The mechanisms were modelled using magnetohydrodynamics (MHD) as a theoretical template. Each mechanism was run through simulations using a Fortran code: ZEUS-3D, an MHD equation solver. The first mechanism modelled the gas dynamics with a modified Hartmann flow which describes the fluid flow between two parallel plates. We initialized the problem based on observation of lagging halos; that is, that the rotational velocity falls to a zero at some height above the plane of the disk. When adopting a density profile which takes into account the various warm and cold H I and HII molecular clouds, the system evolves very strangely and does not reproduce the steady velocity gradient observed in edge-on galaxies. This density profile, adopted from Martos and Cox (1998), was used in the remaining models. However, when treating a system with a uniform density profile, a stable simulation can result. Next we considered supernova (SN) blasts as a possible mechanism for gas ejection. While a single SN was shown to be insufficient to promote vertical gas structures from the disk, multiple SN explosions proved to be enough to promote gas ejection from the disk. In these simulations, gas ejected to a height of 0.5 kpc at a velocity of 130 km s--1 from 500 supernovae, extending to an approximate maximum height of 1 kpc at a velocity of 6.7 x 103 km s--1 from 1500 supernovae after 0.15 Myr, the approximate time of propagation of a supernova shock wave. Finally, we simulated gas flowing into the spiral arm at such a speed to promote a jump in the disk gas, termed a hydraulic jump. The height of the jump was found to be slightly less than a kiloparsec with a flow velocity of 41 km s--1 into the halo after 167 Myr. The latter models proved to be effective mechanisms through which gas is ejected from the disk whereas the Hartmann flow (or toy model) mechanism remains unclear as the

  1. A METHOD IN SYSTEM DESIGN OF EJECTING DEVICES OF MISSILES

    Institute of Scientific and Technical Information of China (English)

    DaiLongcheng; XuanYimin

    2002-01-01

    Anew method in system design of ejecting devices of missiles is first presented.Some important points are dis-cussed,which guid the research and development of new ejecting devices of missileg,amd provid the foundation flr thw design of mew ejecting device is provided.The system design includes the distribution of techmology specifica-tion,3-D solid modeling of ejecting devices of missiles im-ported from abroad,the design of pmeumatic device sys-tem,the design of ejecting mechanism system,the predic-tion of reliability and the experimental analysis,etc.

  2. Role of osmotic and hydrostatic pressures in bacteriophage genome ejection

    CERN Document Server

    Lemay, Serge G; Molineux, Ian J

    2012-01-01

    A critical step in the bacteriophage life cycle is genome ejection into host bacteria. The ejection process for double-stranded DNA phages has been studied thoroughly \\textit{in vitro}, where after triggering with the cellular receptor the genome ejects into a buffer. The experimental data have been interpreted in terms of the decrease in free energy of the densely packed DNA associated with genome ejection. Here we detail a simple model of genome ejection in terms of the hydrostatic and osmotic pressures inside the phage, a bacterium, and a buffer solution/culture medium. We argue that the hydrodynamic flow associated with the water movement from the buffer solution into the phage capsid and further drainage into the bacterial cytoplasm, driven by the osmotic gradient between the bacterial cytoplasm and culture medium, provides an alternative mechanism for phage genome ejection \\textit{in vivo}; the mechanism is perfectly consistent with phage genome ejection \\textit{in vitro}.

  3. Particle Ejection and Levitation Technology (PELT)

    Science.gov (United States)

    2008-01-01

    Each of the six Apollo landers touched down at unique sites on the lunar surface. Aside from the Apollo 12 landing site located 180 meters from the Surveyor III lander, plume impingement effects on ground hardware during the landings were not a problem. The planned return to the Moon requires numerous landings at the same site. Since the top few centimeters of lunar soil are loosely packed regolith, plume impingement from the lander will eject the granular material at high velocities. A picture shows what the astronauts viewed from the window of the Apollo 14 lander. There was tremendous dust excavation beneath the vehicle. With high-vacuum conditions on the Moon (10 (exp -14) to 10 (exp -12) torr), motion of all particles is completely ballistic. Estimates derived from damage to Surveyor III caused by the Apollo 12 lander show that the speed of the ejected regolith particles varies from 100 m/s to 2,000 m/s. It is imperative to understand the physics of plume impingement to safely design landing sites for future Moon missions. Aerospace scientists and engineers have examined and analyzed images from Apollo video extensively in an effort to determine the theoretical effects of rocket exhaust impingement. KSC has joined the University of Central Florida (UCF) to develop an instrument that will measure the 3-D vector of dust flow caused by plume impingement during descent of landers. The data collected from the instrument will augment the theoretical studies and analysis of the Apollo videos.

  4. Energetics of Solar Coronal Mass Ejections

    CERN Document Server

    Subramanian, P; Subramanian, Prasad; Vourlidas, Angelos

    2007-01-01

    Aims: To investigate if solar coronal mass ejections are driven mainly by coupling to the ambient solar wind, or through the release of internal magnetic energy. Methods: We examine the energetics of 39 flux-rope like coronal mass ejections (CMEs) from the Sun using data in the distance range $\\sim$ 2--20 $R_{{\\o}dot}$ from the Large Angle Spectroscopic Coronograph (LASCO) aboard the Solar and Heliospheric Observatory (SOHO). This comprises a complete sample of the best examples of flux-rope CMEs observed by LASCO in 1996-2001. Results: We find that 69% of the CMEs in our sample experience a clearly identifiable driving power in the LASCO field of view. For these CMEs which are driven, we examine if they might be deriving most of their driving power by coupling to the solar wind. We do not find conclusive evidence in favor of this hypothesis. On the other hand, we find that their internal magnetic energy is a viable source of the required driving power. We have estimated upper and lower limits on the power th...

  5. A Subpath Ejection Method for the Vehicle Routing Problem

    OpenAIRE

    1998-01-01

    Generically, ejection chains are methods conceived to allow solution transformations to be efficiently carried out by modifying a variable number of their components at each step of a local search algorithm. We consider a subpath ejection chain method for the vehicle routing problem (VRP) under capacity and route length restrictions. The method undertakes the identification of a substructure named the flower reference structure which, besides coordinating moves during an ejection chain constr...

  6. Transcutaneous iontophoretic delivery of STAT3 siRNA using layer-by-layer chitosan coated gold nanoparticles to treat melanoma.

    Science.gov (United States)

    Labala, Suman; Jose, Anup; Venuganti, Venkata Vamsi Krishna

    2016-10-01

    Overexpression of signal transducer and activator of transcription 3 (STAT3) protein prevents apoptosis and enhances proliferation of melanocytes. The aim of this study was to investigate the feasibility of using layer-by-layer assembled gold nanoparticles (LbL-AuNP) as a carrier for iontophoretic delivery of STAT3 siRNA to treat melanoma. Chitosan coated AuNP (AuNP-CS) were prepared by direct reduction of HAuCl4 in the presence of chitosan. The AuNP-CS were then sequentially layered with siRNA and chitosan to form AuNP-CS/siRNA/CS. STAT3 siRNA replaced with scrambled siRNA or sodium alginate were used as controls. The average particle size and zeta-potential of the prepared LbL-AuNP were 150±10nm (PDI: 0.41±0.06) and 35±6mV, respectively. In vitro studies in B16F10 murine melanoma cells showed that AuNP-CS/siRNA/CS inhibited the cell growth by 49.0±0.6% and 66.0±0.2% at 0.25nM and 0.5nM STAT3 siRNA concentration, respectively. Fluorescence microscopy and flow cytometry studies showed a time dependent cell uptake of the LbL-AuNP up to 120min. Clathrin mediated endocytosis was found to be the predominant cell uptake mechanism for LbL-AuNP. STAT3 siRNA loaded LbL-AuNP reduced the STAT3 protein expression by 47.3% in B16F10 cells. Similarly, apoptosis assay showed 29% and 44% of early and late apoptotic events, respectively after treatment with STAT3 siRNA loaded LbL-AuNP. Confocal microscope and skin cryosections showed that application of 0.47mA/cm(2) of anodal iontophoresis enhanced the skin penetration of LbL-AuNP to reach viable epidermis. In conclusion, layer-by-layer chitosan coated AuNP can be developed as a carrier for iontophoretic delivery of STAT3 siRNA to treat melanoma.

  7. Acoustic and aerodynamic characteristics of ejectives in Amharic

    Science.gov (United States)

    Demolin, Didier

    2004-05-01

    This paper invetsigates the main phonetic characteristics that distinguishes ejectives from pulmonic sounds in Amharic. In this language, there are five ejectives that can be phonemically singleton or geminate. Duration measurements have been made in intervocalic position for pulmonic stops and for each type of ejective, taking into account the overall duration and VOT. Results show that ejective stops have a higher amplitude burst than pulmonic stops. The duration of the noise is shorter for ejective fricatives compared to pulmonic fricatives. At the end of ejective fricatives, there is a 30-ms glottal lag that is not present in pulmonic fricatives. Geminate ejectives are realized by delaying the elevation of the larynx. This can be observed on the spectrographic data by an increase of the noise at the end of the geminate ejectives. Aerodynamic data have been collected in synchronization with the acoustic recordings. The main observations are that pharyngeal pressures values are much higher than what is usually assumed (up to 40 CmH2O for velars) and that the delayed command in the elevation of the larynx of geminate ejectives is shown by two phases in the rise of pharyngeal pressure.

  8. Case of Acute Graft Failure during Suspected Humoral Rejection with Preserved Ejection Fraction, but Severely Reduced Longitudinal Deformation Detected by 2D-Speckle Tracking

    Directory of Open Access Journals (Sweden)

    Tor Skibsted Clemmensen

    2014-01-01

    Full Text Available This case displays limited utility of left ventricular ejection fraction to detect acute graft failure due to microvascular vasculopathy and suspected humoral rejection. Despite severe and progressive graft failure, clinically and by right heart catheterizations, left ventricular ejection fraction remained unchanged, indicating need of more reliable noninvasive methods for graft function surveillance. Global longitudinal strain relates to clinical heart failure, filling pressure, and cardiac index during suspected humoral rejection and microvascular dysfunction in this HTX patient. We suggest routine monitoring of graft function by global longitudinal strain as supplement to routine left ventricular ejection fraction and diastolic Doppler measurements.

  9. Magnetic structure of Coronal Mass Ejections

    CERN Document Server

    Lyutikov, Maxim

    2012-01-01

    We present several models of the magnetic structure of solar coronal mass ejections (CMEs). First, we model CMEs as expanding force-free magnetic structures. While keeping the internal magnetic field structure of the stationary solutions, expansion leads to complicated internal velocities and rotation, while the field structures remain force-free. Second, expansion of a CME can drive resistive dissipation within the CME changing the ionization states of different ions. We fit in situ measurements of ion charge states to the resistive spheromak solutions. Finally, we consider magnetic field structures of fully confined stable magnetic clouds containing both toroidal and poloidal magnetic fields and having no surface current sheets. Expansion of such clouds may lead to sudden onset of reconnection events.

  10. Coronal Mass Ejections: From Sun to Earth

    Science.gov (United States)

    Patsourakos, S.

    2016-06-01

    Coronal Mass Ejections (CMEs) are gigantic expulsions of magnetized plasmas from the solar corona into the interplanetary (IP) space. CMEs spawn ~ 1015 gr of mass and reach speeds ranging between several hundred to a few thousand km/s (e.g., Gopalswamy et al. 2009; Vourlidas et al. 2010). It takes 1-5 days for a CME to reach Earth. CMEs are one of the most energetic eruptive manifestations in the solar system and are major drivers of space weather via their magnetic fields and energetic particles, which are accelerated by CME-driven shocks. In this review we give a short account of recent, mainly observational, results on CMEs from the STEREO and SDO missions which include the nature of their pre-eruptive and eruptive configurations and the CME propagation from Sun to Earth. We conclude with a discussion of the exciting capabilities in CME studies that will soon become available from new solar and heliospheric instrumentation.

  11. Periodicities in Solar Coronal Mass Ejections

    CERN Document Server

    Lou, Y Q; Fan, Z; Wang, S; Wang, J

    2003-01-01

    Mid-term quasi-periodicities in solar coronal mass ejections (CMEs) during the most recent solar maximum cycle 23 are reported here for the first time using the four-year data (February 5, 1999 to February 10, 2003) of the Large Angle Spectrometric Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO). In parallel, mid-term quasi-periodicities in solar X-ray flares (class >M5.0) from the Geosynchronous Operational Environment Satellites (GOES) and in daily averages of Ap index for geomagnetic disturbances from the World Data Center (WDC) at the International Association for Geomagnetism and Aeronomy (IAGA) are also examined for the same four-year time span. Several conceptual aspects of possible equatorially trapped Rossby-type waves at and beneath the solar photosphere are discussed.

  12. Kinematical properties of coronal mass ejections

    CERN Document Server

    Temmer, Manuela

    2016-01-01

    Coronal mass ejections (CMEs) are the most dynamic phenomena in our solar system. They abruptly disrupt the continuous outflow of solar wind by expelling huge clouds of magnetized plasma into interplanetary space with velocities enabling to cross the Sun-Earth distance within a few days. Earth-directed CMEs may cause severe geomagnetic storms when their embedded magnetic fields and the shocks ahead compress and reconnect with the Earth's magnetic field. The transit times and impacts in detail depend on the initial CME velocity, size, and mass, as well as on the conditions and coupling processes with the ambient solar wind flow in interplanetary space. The observed CME parameters may be severly affected by projection effects and the constant changing environmental conditions are hard to derive. This makes it difficult to fully understand the physics behind CME evolution, preventing to do a reliable forecast of Earth-directed events. This short review focusing on observational data, shows recent methods which w...

  13. Planet Scattering Around Binaries: Ejections, Not Collisions

    CERN Document Server

    Smullen, Rachel A; Shannon, Andrew

    2016-01-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically effects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Asid...

  14. Solar Eruptions: Coronal Mass Ejections and Flares

    Science.gov (United States)

    Gopalswamy, Nat

    2012-01-01

    This lecture introduces the topic of Coronal mass ejections (CMEs) and solar flares, collectively known as solar eruptions. During solar eruptions, the released energy flows out from the Sun in the form of magnetized plasma and electromagnetic radiation. The electromagnetic radiation suddenly increases the ionization content of the ionosphere, thus impacting communication and navigation systems. Flares can be eruptive or confined. Eruptive flares accompany CMEs, while confined flares hav only electromagnetic signature. CMEs can drive MHD shocks that accelerate charged particles to very high energies in the interplanetary space, which pose radiation hazard to astronauts and space systems. CMEs heading in the direction of Earth arrive in about two days and impact Earth's magnetosphere, producing geomagnetic storms. The magnetic storms result in a number of effects including induced currnts that can disrupt power grids, railroads, and underground pipelines

  15. Boulders Ejected From Small Impact Craters

    Science.gov (United States)

    Bart, Gwendolyn D.; Melosh, H. J.

    2006-09-01

    We investigate the distribution of boulders ejected from lunar craters by analyzing high resolution Lunar Orbiter images. Our previous study (DPS 2004) of four small craters indicated that larger boulders are more frequently found close to the crater rim rather than far away, and that the size of the ejecta drops off as a power law with distance from the crater. Our current study adds more than ten new bouldery craters that range in size from 200 m to several kilometers and are found on a variety of terrain (mare, highlands, and the Copernicus ejecta blanket.) For each crater we plot the boulder diameter as a function of the ejection velocity of the boulder. We compare this size-velocity distribution with the size-velocity distribution of ejecta from large craters (Vickery 1986, 1987) to ascertain the mechanism of fracture of the substrate in the impact. We also make cumulative plots of the boulders, indicating the number of boulders of each size present around the crater. The cumulative plots allow us to compare our boulder distributions with the distributions of secondary craters from large impacts. Material thrown from a several-hundred-meter diameter crater may land intact as boulders, but material thrown from a tens-of-kilometers diameter crater will travel at a significantly higher velocity, and will form a secondary crater when it impacts the surface. Our data helps elucidate whether the upturn, at small diameters, of the cratering curve of the terrestrial planets is due to secondary impacts or to the primary population. This work is funded by NASA PGG grant NNG05GK40G.

  16. Animal models of heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    G. Conceição; I. Heinonen (Ilkka); A.P. Lourenço; D.J.G.M. Duncker (Dirk); I. Falcão-Pires

    2016-01-01

    textabstractHeart failure with preserved ejection fraction (HFpEF) constitutes a clinical syndrome in which the diagnostic criteria of heart failure are not accompanied by gross disturbances of systolic function, as assessed by ejection fraction. In turn, under most circumstances, diastolic function

  17. Fighter Pilot Ejection Study as an Educational Tool

    Science.gov (United States)

    Robinson, Garry; Jovanoski, Zlatko

    2010-01-01

    In this article, we apply the well-known equations of projectile motion to the case of a fighter pilot ejecting from an aircraft, the aim being to establish under what conditions there is danger of impact with the rear vertical stabilizer. The drag force on the pilot after ejection is assumed to vary as the velocity squared and the aircraft motion…

  18. Fast ejection chain algorithms for vehicle routing with time windows

    NARCIS (Netherlands)

    Sontrop, Herman; Blesa, M.J.; Blum, C.; van der Horn, Pieter; Uetz, Marc Jochen; Roli, A.; Sampels, M.

    This paper introduces a new algorithm, based on the concept of ejection chains, to effectively target vehicle routing problems with time window constraints (VRPTW). Ejection chains create powerful compound moves within Local Search algorithms. Their potential to yield state of the art algorithms has

  19. Polymer ejection from bacteriophages is fully determined by confinement energy

    CERN Document Server

    Piili, J

    2015-01-01

    The ejection dynamics through a nanoscale pore of a flexible polymer that is initially strongly confined inside a spherical capsid is examined. By extensive simulations using the stochastic rotation dynamics method we show that the time for an individual monomer to eject grows exponentially with the number of ejected monomers under constant initial monomer density. This dependence is a consequence of the excess free energy of the polymer due to confinement growing exponentially with the initial monomer number inside the capsid, which we address to strong monomer-monomer interactions. Consequently, for sufficiently strong initial confinement and long polymers ejection times for polymers of different lengths depend linearly on the length. At polymer lengths amenable to computer simulations the dependence is superlinear due to the finite-size effect related to the retraction of polymer tails at final stages of ejection.

  20. Summoning the wind: Hydrodynamic cooperation of forcibly ejected fungal spores

    CERN Document Server

    Roper, Marcus; Cobb, Ann; Dillard, Helene R; Pringle, Anne

    2009-01-01

    The forcibly launched spores of the crop pathogen \\emph{Sclerotinia sclerotiorum} must eject through many centimeters of nearly still air to reach the flowers of the plants that the fungus infects. Because of their microscopic size, individually ejected spores are quickly brought to rest by drag. In the accompanying fluid dynamics video we show experimental and numerical simulations that demonstrate how, by coordinating the nearly simultaneous ejection of hundreds of thousands of spores,\\emph{Sclerotinia} and other species of apothecial fungus are able to sculpt a flow of air that carries spores across the boundary layer and around intervening obstacles. Many spores are sacrificed to create this flow of air. Although high speed imaging of spore launch in a wild isolate of the dung fungus \\emph{Ascobolus} shows that the synchronization of spore ejections is self-organized, which could lead to spores delaying their ejection to avoid being sacrificed, simulations and asymptotic analysis show that, close the frui...

  1. Ejection experience in Serbian air force, 1990-2010

    Directory of Open Access Journals (Sweden)

    Pavlović Miroslav

    2014-01-01

    Full Text Available Background/Aim. Ejection injuries are the problem for air forces. The present risk for injuries is still too high, approximately 30-50%. This study was an effort to determine factors responsible for and contributing to injuries in the Serbian Air Force (SAF in the last two decades. Methods. All ejection cases in the SAF between 1990 and 2010 were analyzed. The collected data were: aircraft type, ejection seat generation, pilots ´ age and experience, causes of ejection, aeronautical parameters, the condition of aircraft control and types of injuries. For ease of comparison the U.S. Air Force Safety Regulation was used to define of major injuries: hospitalization for 5 days or more, loss of consciousness for over 5 min, bone fracture, joint dislocation, injury to any internal organ, any third-degree burn, or second-degree burn over 5% of the body surface area. Results. There were 52 ejections (51 pilots and 1 mechanic on 44 airplanes. The ejected persons were from 22 to 46 years, average 32 years. Major injuries were present in 25.49% cases. Of all the ejected pilots 9.61% had fractures of thoracic spine, 11.53% fractures of legs, 3.48% fractures of arms. Of all major injuries, fractures of thoracic spine were 38.46%. None of the pilots had experienced ejection previously. Conclusion. Our results suggest to obligatory take preventive measures: magnetic resonance imaging (MRI scan must be included in the standard pilot selection procedure and procedure after ejection. Physical conditioning of pilots has to be improved. Training on ejection trainer has to be accomplished, too.

  2. Radio-quiet Fast Coronal Mass Ejections

    Science.gov (United States)

    Gopalswamy, N.; Aguilar-Rodriguez, E.; Kaiser, M. L.; Howard, R. A.

    2004-12-01

    Coronal mass ejections (CMEs) drive shocks in the interplanetary medium that produce type II radio emission. These CMEs are faster and wider on the average, than the general population of CMEs. However, when we start from fast (speed > 900 km/s) and wide (angular width > 60 degrees), more than half of them are not associated with radio bursts. In order to understand why these CMEs are radio quiet, we collected all the fast and wide (FW) CMEs detected by the Solar and Heliospheric Observatory (SOHO) mission's Large Angle and Spectrometric Coronagraph (LASCO) and isolated those without associated type II radio bursts. The radio bursts were identified in the dynamic spectra of the Radio and Plasma Wave (WAVES) Experiment on board the Wind spacecraft. We also checked the list against metric type II radio bursts reported in Solar Geophysical Data and isolated those without any radio emission. This exercise resulted in about 140 radio-quiet FW CMEs. We identified the source regions of these CMEs using the Solar Geophysical Data listings, cross-checked against the eruption regions in the SOHO/EIT movies. We explored a number of possibilities for the radio-quietness: (i) Source region being too far behind the limb, (ii) flare size, (iii) brightness of the CME, and (iv) the density of the ambient medium. We suggest that a combination of CME energy and the Alfven speed profile of the ambient medium is primarily responsible for the radio-quietness of these FW CMEs.

  3. Anatomy of Depleted Interplanetary Coronal Mass Ejections

    Science.gov (United States)

    Kocher, M.; Lepri, S. T.; Landi, E.; Zhao, L.; Manchester, W. B., IV

    2017-01-01

    We report a subset of interplanetary coronal mass ejections (ICMEs) containing distinct periods of anomalous heavy-ion charge state composition and peculiar ion thermal properties measured by ACE/SWICS from 1998 to 2011. We label them “depleted ICMEs,” identified by the presence of intervals where C6+/C5+ and O7+/O6+ depart from the direct correlation expected after their freeze-in heights. These anomalous intervals within the depleted ICMEs are referred to as “Depletion Regions.” We find that a depleted ICME would be indistinguishable from all other ICMEs in the absence of the Depletion Region, which has the defining property of significantly low abundances of fully charged species of helium, carbon, oxygen, and nitrogen. Similar anomalies in the slow solar wind were discussed by Zhao et al. We explore two possibilities for the source of the Depletion Region associated with magnetic reconnection in the tail of a CME, using CME simulations of the evolution of two Earth-bound CMEs described by Manchester et al.

  4. Planet scattering around binaries: ejections, not collisions

    Science.gov (United States)

    Smullen, Rachel A.; Kratter, Kaitlin M.; Shannon, Andrew

    2016-09-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary star and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically affects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Systems similar to the only observed multiplanet circumbinary system, Kepler-47, can arise from much more tightly packed, unstable systems. Only extreme initial conditions introduce differences in the final planet populations. Thus, we suggest that any intrinsic differences in the populations are imprinted by formation.

  5. Anisotropic mass ejection in binary mergers

    CERN Document Server

    Morris, T; Podsiadlowski, Ph.

    2006-01-01

    We investigate the mass loss from a rotationally distorted envelope following the early, rapid in-spiral of a companion star inside a common envelope. For initially wide, massive binaries (M_1+M_2=20M_{\\odot}, P\\sim 10 yr), the primary has a convective envelope at the onset of mass transfer and is able to store much of the available orbital angular momentum in its expanded envelope. Three-dimensional SPH calculations show that mass loss is enhanced at mid-latitudes due to shock reflection from a torus-shaped outer envelope. Mass ejection in the equatorial plane is completely suppressed if the shock wave is too weak to penetrate the outer envelope in the equatorial direction (typically when the energy deposited in the star is less than about 1/3 of the binding energy of the envelope). We present a parameter study to show how the geometry of the ejecta depends on the angular momentum and the energy deposited in the envelope during a merging event. Applications to the nearly axisymmetric, but very non-spherical ...

  6. Reconnection in a slow Coronal Mass Ejection

    Directory of Open Access Journals (Sweden)

    G. Poletto

    2008-10-01

    Full Text Available This paper aims at studying reconnection occurring in the aftermath of the 28 May 2004, CME, first imaged by the LASCO (Large Angle and Spectrometric Coronagraph C2 at 11:06 UT. The CME was observed in White Light and UV radiation: images acquired by the LASCO C2 and C3 coronagraphs and spectra acquired by UVCS (Ultraviolet Coronagraph Spectrometer allowed us to identify the level at which field lines, stretched outwards by the CME ejection, reconnect below the CME bubble. As the CME propagates outwards, reconnection occurs at increasingly higher levels. The process goes on at a low pace for several hours: here we give the profile of the reconnection rate vs. heliocentric distance over a time interval of ≈14 h after the CME onset, extending estimates of the reconnection rate to larger distances than previously inferred by other authors. The reconnection rate appears to decrease with time/altitude. We also calculate upper and lower limits to the density in the diffusion region between 4 and 7 R and conclude by comparing estimates of the classical and anomalous resistivity in the diffusion region with the value inferred from the data. The latter turns out to be ≥5 order of magnitudes larger than predicted by classical or anomalous theories, pointing to the need of identifying the process responsible for the observed value.

  7. Why are halo coronal mass ejections faster?

    Institute of Scientific and Technical Information of China (English)

    Qing-Min Zhang; Yang Guo; Peng-Fei Chen; Ming-De Ding; Cheng Fang

    2010-01-01

    Halo coronal mass ejections(CMEs)have been to be significantly faster than normal CMEs,which is a long-standing puzzle.In order to solve the puzzle,we first investigate the observed properties of 31 limb CMEs that clearly display loopshaped frontal loops.The observational results show a strong tendency that slower CMEs are weaker in white-light intensity.Then,we perform a Monte Carlo simulation of 20000 artificial limb CMEs that have an average velocity of~523 km s-1.The Thomson scattering of these events is calculated when they are assumed to be observed as limb and halo events,respectively.It is found that the white-light intensity of many slow CMEs becomes remarkably reduced when they turn from being viewed as a limb event to being viewed as a halo event.When the intensity is below the background solar wind fluctuation,it is assumed that they would be missed by coronagraphs.The average velocity of"detectable"halo CMEs is~922 km s-1,very close to the observed value.This also indicates that wider events are more likely to be recorded.The results soundly suggest that the higher average velocity of halo CMEs is due to that a majority of slow events and some of narrow fast events carrying less material are so faint that they are blended with the solar wind fluctuations,and therefore are not observed.

  8. Active Longitude and Coronal Mass Ejection Occurrences

    Science.gov (United States)

    Gyenge, N.; Singh, T.; Kiss, T. S.; Srivastava, A. K.; Erdélyi, R.

    2017-03-01

    The spatial inhomogeneity of the distribution of coronal mass ejection (CME) occurrences in the solar atmosphere could provide a tool to estimate the longitudinal position of the most probable CME-capable active regions in the Sun. The anomaly in the longitudinal distribution of active regions themselves is often referred to as active longitude (AL). In order to reveal the connection between the AL and CME spatial occurrences, here we investigate the morphological properties of active regions. The first morphological property studied is the separateness parameter, which is able to characterize the probability of the occurrence of an energetic event, such as a solar flare or CME. The second morphological property is the sunspot tilt angle. The tilt angle of sunspot groups allows us to estimate the helicity of active regions. The increased helicity leads to a more complex buildup of the magnetic structure and also can cause CME eruption. We found that the most complex active regions appear near the AL and that the AL itself is associated with the most tilted active regions. Therefore, the number of CME occurrences is higher within the AL. The origin of the fast CMEs is also found to be associated with this region. We concluded that the source of the most probably CME-capable active regions is at the AL. By applying this method, we can potentially forecast a flare and/or CME source several Carrington rotations in advance. This finding also provides new information for solar dynamo modeling.

  9. Pulse Ejection Presentation System Synchronized with Breathing

    Science.gov (United States)

    Kadowaki, Ami; Sato, Junta; Ohtsu, Kaori; Bannai, Yuichi; Okada, Kenichi

    Trials on transmission of olfactory information together with audio/visual information are currently being conducted in the field of multimedia. However, continuous emission of scents in high concentration creates problems of human adaptation and remnant odors in air. To overcome such problems we developed an olfactory display in conjunction with Canon Inc. This display has high emission control in the ink-jet so that it can provide stable pulse emission of scents. Humans catch a scent when they breathe in and inhale smell molecules in air. Therefore, it is important that the timing of scent presentation is synchronized with human breathing. We also developed a breath sensor which detects human inspiration. In this study, we combined the olfactory display with the breath sensor to make a pulse ejection presentation system synchronized the breath. The experimental evaluation showed that the system had more than 90 percent of detection rate. Another evaluation was held at KEIO TECHNO-MALL 2007. From questionnaire results of the participants, we found that the system made the user feel continuous sense of smell avoiding adaptation. It is expected that our system enables olfactory information to be synchronized with audio/visual information in arbitrary duration at any time.

  10. Ejection of small droplet from microplate using focused ultrasound

    Science.gov (United States)

    Tanaka, Hiroki; Mizuno, Yosuke; Nakamura, Kentaro

    2017-08-01

    We discussed an ultrasonic system for single-droplet ejection from a microplate, which is one of the basic and important procedures in the noncontact handling of droplets in air. In this system, a 1.5 MHz concave transducer located below the microplate is used for chasing the liquid surface through a pulse echo method, and also for the ejection of a 1 µL single droplet by the burst of focused ultrasound. We investigated the relationship between the droplet ejection characteristics, the distance from the transducer to the surface of liquid, the material property, and the excitation condition of the focused ultrasonic transducer. It was verified that the optimal position of the transducer was off the focal point of sound pressure by ±1 mm, because the sound intensity had to be controlled to eject a single droplet. Subsequently, we confirmed experimentally that the ejected droplet volume linearly depended on the surface tension of the liquid, and that the droplet volume and ejection velocity were determined by the Webber number, Reynolds number, and Ohnesolge number. In addition, by optimizing the duration of the burst ultrasound, the droplet volume and ejection velocity were controlled.

  11. Improved Measurement of Ejection Velocities From Craters Formed in Sand

    Science.gov (United States)

    Cintala, Mark J.; Byers, Terry; Cardenas, Francisco; Montes, Roland; Potter, Elliot E.

    2014-01-01

    A typical impact crater is formed by two major processes: compression of the target (essentially equivalent to a footprint in soil) and ejection of material. The Ejection-Velocity Measurement System (EVMS) in the Experimental Impact Laboratory has been used to study ejection velocities from impact craters formed in sand since the late 1990s. The original system used an early-generation Charge-Coupled Device (CCD) camera; custom-written software; and a complex, multicomponent optical system to direct laser light for illumination. Unfortunately, the electronic equipment was overtaken by age, and the software became obsolete in light of improved computer hardware.

  12. Pediatric keratoconus and iontophoretic corneal crosslinking: refractive and topographic evidence in patients underwent general and topical anesthesia, 18 months of follow-up.

    Science.gov (United States)

    Magli, Adriano; Chiariello Vecchio, Elisabetta; Carelli, Roberta; Piozzi, Elena; Di Landro, Felicia; Troisi, Salvatore

    2016-08-01

    To evaluate the efficiency and safety of iontophoretic transepithelial corneal crosslinking in pediatric patients with progressive keratoconus underwent general or topical anesthesia in 18 months follow-up. 13 patients (13 eyes) diagnosed with progressive keratoconus underwent corneal CXL with iontophoresis (I-CXL). Riboflavin solution was administered by iontophoresis for 5 min, and then UV-A irradiation (10 mW/cm) was performed for 9 min. Preoperative and post-operative visits at 1, 6, 12, and 18 months assessed the following parameters: uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, corneal topography, optical tomography, and pachymetry with Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany), endothelial biomicroscopy (Konan Specular Microscope; Konan Medical, Inc., Hyogo, Japan). The paired Student t test was used to compare data during the follow-up. 10 males and 3 females with a mean age of 15.4 ± 1.7 years (range 11-18 years) were included. The results showed a stabilization of the refractive UCVA and BCVA as early as the first post-operative month, with a slight improvement over time. The Kmax remained stable throughout follow-up (p = 0.04). Transepithelial collagen crosslinking by iontophoresis, unlike other transepithelial techniques seems to halt pediatric keratoconus progression over 18 months. This is the second study evaluating CXL with iontophoresis in pediatric patients with progressive keratoconus with 18 months of follow-up using two different ways of anesthesia.

  13. Use of Fentanyl Iontophoretic Transdermal System (ITS) (IONSYS(®)) in the Management of Patients with Acute Postoperative Pain: A Case Series.

    Science.gov (United States)

    Poplawski, Steven; Johnson, Matthew; Philips, Philip; Eberhart, Leopold H J; Koch, Tilo; Itri, Loretta M

    2016-12-01

    Fentanyl iontophoretic transdermal system (ITS) [IONSYS(®), The Medicines Company, Parsippany, NJ, USA] is a needle-free, patient-controlled, postoperative opioid pain management treatment. It is indicated for the short-term management of acute postoperative pain in adults requiring opioid analgesia in the hospital. The safety and effectiveness of fentanyl ITS for acute postoperative pain management has been demonstrated in a range of surgery and patient types studied in seven phase 3 trials (three placebo-controlled trials and four active-comparator trials). The majority of the patients in the phase 3 trials had undergone either abdominal/pelvic, orthopedic, or thoracic surgery. Consistent with the prescribing information, physicians in clinical practice may treat patients with this system following any type of surgery including those that may not have been included in the phase 3 trials. The purpose of this case series is to illustrate how fentanyl ITS is being utilized for postoperative pain management in real-world clinical practice following a variety of surgeries and in current pain management protocols that may have evolved since the completion of the phase 3 program. There are seven cases from three clinical centers described within this case series, each using fentanyl ITS according to the prescribing information. The surgery types included are bariatric (N = 3), prostate (N = 2), colorectal (N = 1), and perirectal abscess drainage (N = 1). A systematic review of each patient chart was conducted via a standardized retrospective assessment by the clinicians who managed each patient. Additionally, each healthcare professional was interviewed regarding their overall experience and key learnings using fentanyl ITS. Overall, fentanyl ITS was effective and well tolerated in these case reports in current-day clinical practice settings. These case studies are informative about fentanyl ITS use shortly after product approval and set the stage for

  14. Stealthy but Geoeffective Coronal Mass Ejections

    Science.gov (United States)

    Nitta, Nariaki; Mulligan, Tamitha

    2017-08-01

    We have long known about the existence of "problem" geomagnetic storms whose origins are elusive. In more general terms, not all the 1 AU disturbances can be clearly attributed to coronal mass ejections (CMEs), high speed streams (HSSs) or corotation interaction regions (CIRs.) When interplanetary CME (ICME) signatures are found in in situ data, there is not always a flare or filament eruption on the Sun or even an obvious CME observed close to the Sun that correlates with the ICME within a reasonable time range. These ICMEs sometimes result in intense storms. Furthermore, there is a possibility that some of the more severe storms could be partly contributed by such ICMEs of unclear origin. Therefore space weather prediction will remain incomplete without properly understanding these ICMEs. Even if the ICME is paired with a CME, it is sometimes difficult to find where the latter comes from. This is often called the “stealth CME” that apparently lacks low coronal signatures (LCSs). STEREO's second and third view points have tremendously helped us determine its front-side origin and find when and where it forms and accelerates, which is important for isolating possible LCSs. Although SDO/AIA has been continuously taking full-disk EUV images in a wide temperature range since 2010, there are still a number of stealthy CMEs whose LCSs are unclear or ambiguous. It is assumed that they start at high altitudes, leaving weak or negligible LCSs. Some of them seem to involve multiple magnetic domains, and weak or open field regions. We present AIA observations of several stealthy CMEs, including recent ones, that were responsible for geomagnetic storms, emphasizing the need to compare images with long time differences and to find the periods at which the CME forms and accelerates. We also discuss uncertainties in interpreting in situ data as to whether a CME is present when data are dominated by other solar wind features, such as HSS and CIR.

  15. Forecasting Coronal Mass Ejections from Vector Magnetograms

    Science.gov (United States)

    Falconer, D. A.; Moore, R. L.; Gary, G. A.; Six, N. Frank (Technical Monitor)

    2002-01-01

    In a 17 vector magnetogram study of 12 bipolar active regions (Falconer, Moore, & Gary, 2002, ApJ in press), we correlated four quantitative global magnetic measures with the Coronal Mass Ejections (CME) productivity of the active region. The global measures included a measure of active region size, the total magnetic flux phi and three measures of an active region global nonpotentiality 1) the net current (I (sub N)), 2) the length of the strong-shear, strong-field main neutral line (L(sub SS)) and 3) and the normalized twist (alpha = muIN/PHI). The CME productivity was determined from YOHKOH/SXT observations, Geostationary Operational Environmental Satellite (GOES), and when possible Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph Experiment (SOHO/LASCO) observations within 12 days of the day of the magnetogram. We found that the three measures of global nonpotentiality (I(sub N), L(sub SS), alpha) were all well correlated (greater than 99% confidence level) with an active region's CME productivity. The sample size was to small to confirm if there was a statistical significant correlation of the globally nonscientist measures with future CME activity (i.e. from the date of the magnetogram forward). We are doubling our sample, and will report on the statistical significance of global nonpotentiality as a predictor of future CME productivity. The new active regions are all from the first year of the upgraded MSFC vector magnetograms. This work, is funded by NSF through the Space Weather Program, by NASA through the Living with the Star, Targeted Research and Technology, and by NASA Solar Physics Supporting Research and Technology Program. The upgrade to the MSFC vector magnetograph was supported by the High Energy Solar Spectroscopic Imager (HESSI) mission.

  16. Nanodust dynamics during a coronal mass ejection

    Science.gov (United States)

    Czechowski, Andrzej; Kleimann, Jens

    2017-09-01

    The dynamics of nanometer-sized grains (nanodust) is strongly affected by electromagnetic forces. High-velocity nanodust was proposed as an explanation for the voltage bursts observed by STEREO. A study of nanodust dynamics based on a simple time-stationary model has shown that in the vicinity of the Sun the nanodust is trapped or, outside the trapped region, accelerated to high velocities. We investigate the nanodust dynamics for a time-dependent solar wind and magnetic field configuration in order to find out what happens to nanodust during a coronal mass ejection (CME). The plasma flow and the magnetic field during a CME are obtained by numerical simulations using a 3-D magnetohydrodynamic (MHD) code. The equations of motion for the nanodust particles are solved numerically, assuming that the particles are produced from larger bodies moving in near-circular Keplerian orbits within the circumsolar dust cloud. The charge-to-mass ratios for the nanodust particles are taken to be constant in time. The simulation is restricted to the region within 0.14 AU from the Sun. We find that about 35 % of nanodust particles escape from the computational domain during the CME, reaching very high speeds (up to 1000 km s-1). After the end of the CME the escape continues, but the particle velocities do not exceed 300 km s-1. About 30 % of all particles are trapped in bound non-Keplerian orbits with time-dependent perihelium and aphelium distances. Trapped particles are affected by plasma ion drag, which causes contraction of their orbits.

  17. Could Jupiter or Saturn Have Ejected a Fifth Giant Planet?

    CERN Document Server

    Cloutier, Ryan; Valencia, Diana

    2015-01-01

    Models of the dynamical evolution of the early solar system following the dispersal of the gaseous protoplanetary disk have been widely successful in reconstructing the current orbital configuration of the giant planets. Statistically, some of the most successful dynamical evolution simulations have initially included a hypothetical fifth giant planet, of ice giant mass, which gets ejected by a gas giant during the early solar system's proposed instability phase. We investigate the likelihood of an ice giant ejection event by either Jupiter or Saturn through constraints imposed by the current orbits of their wide-separation regular satellites Callisto and Iapetus respectively. We show that planetary encounters that are sufficient to eject an ice giant, often provide excessive perturbations to the orbits of Callisto and Iapetus making it difficult to reconcile a planet ejection event with the current orbit of either satellite. Quantitatively, we compute the likelihood of reconciling a regular Jovian satellite ...

  18. Anticipating the Geoeffectiveness of Coronal Mass Ejections Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Coronal Mass Ejections (CMEs) are responsible for some of the most severe space weather at Earth. Major geomagnetic storms arise when CMEs carry large amounts of...

  19. "Paradoxical" reduction in postexercise ejection time and increased transthoracic impedance.

    Science.gov (United States)

    Nakamura, Y; Kotilainen, P; Haffty, B; Jolda, R; Bishop, R; Spodick, D

    1978-12-01

    Despite decreasing heart rate, left ventricular ejection time (LVET) transiently falls immediately following bicycle exercise. In seven normal, untrained subjects LVET decreases at 15 s postexercise corresponded (r = 0.78) with an increase in transthoracic electrical impedance (Z) consistent with decreased venous return to the thorax. Because the determinants of LVET are stroke volume (SV) and ejection rate, the deltaZ implies that decreased SV contributed to the "paradoxical" fall in LVET.

  20. Animal models of heart failure with preserved ejection fraction

    OpenAIRE

    Conceição, G.; Heinonen, I.; Lourenço, A. P.; Duncker, D. J.; Falcão-Pires, I.

    2016-01-01

    Heart failure with preserved ejection fraction (HFpEF) constitutes a clinical syndrome in which the diagnostic criteria of heart failure are not accompanied by gross disturbances of systolic function, as assessed by ejection fraction. In turn, under most circumstances, diastolic function is impaired. Although it now represents over 50 % of all patients with heart failure, the mechanisms of HFpEF remain understood, precluding effective therapy. Understanding the pathophysiology of HFpEF has be...

  1. Chromospheric Plasma Ejections in a Light Bridge of a Sunspot

    Science.gov (United States)

    Song, Donguk; Chae, Jongchul; Yurchyshyn, Vasyl; Lim, Eun-Kyung; Cho, Kyung-Suk; Yang, Heesu; Cho, Kyuhyoun; Kwak, Hannah

    2017-02-01

    It is well-known that light bridges (LBs) inside a sunspot produce small-scale plasma ejections and transient brightenings in the chromosphere, but the nature and origin of such phenomena are still unclear. Utilizing the high-spatial and high-temporal resolution spectral data taken with the Fast Imaging Solar Spectrograph and the TiO 7057 Å broadband filter images installed at the 1.6 m New Solar Telescope of Big Bear Solar Observatory, we report arcsecond-scale chromospheric plasma ejections (1.″7) inside a LB. Interestingly, the ejections are found to be a manifestation of upwardly propagating shock waves as evidenced by the sawtooth patterns seen in the temporal-spectral plots of the Ca ii 8542 Å and Hα intensities. We also found a fine-scale photospheric pattern (1″) diverging with a speed of about 2 km s‑1 two minutes before the plasma ejections, which seems to be a manifestation of magnetic flux emergence. As a response to the plasma ejections, the corona displayed small-scale transient brightenings. Based on our findings, we suggest that the shock waves can be excited by the local disturbance caused by magnetic reconnection between the emerging flux inside the LB and the adjacent umbral magnetic field. The disturbance generates slow-mode waves, which soon develop into shock waves, and manifest themselves as the arcsecond-scale plasma ejections. It also appears that the dissipation of mechanical energy in the shock waves can heat the local corona.

  2. An Experimental Investigation of Vibration-Induced Single Droplet Ejection.

    Science.gov (United States)

    Range, Kai; Smith, Marc K.; Glezer, Ari

    1998-11-01

    Vibration-induced droplet atomization occurs when small secondary droplets are ejected from the free surface of a larger droplet placed on a vibrating membrane. To model a single ejection event, a liquid droplet is placed on a small piston and vibrated using an electromagnetic driver. The droplet oscillates in a characteristic mode shape that depends on the driving frequency and amplitude, the properties of the liquid, and the size of the droplet. When the excitation amplitude is large enough, a small secondary droplet is ejected from the primary droplet. Observations of this process using high-speed digital video imaging show that droplet ejection occurs when a small liquid column or jet appears on the primary droplet and a secondary droplet forms on the column by a capillary-pinching mechanism. The liquid column or jet emanates from a crater in the primary droplet. As the driving frequency increases, this crater becomes smaller and the diameter of the ejected droplet decreases. We shall present results showing how the ejected droplet diameter and speed depends on the driving frequency and amplitude, the liquid properties, and the primary droplet volume.

  3. Interplanetary Coronal Mass Ejection (ICME) and Cosmic rays transmission during Forbush decreases

    Science.gov (United States)

    Okpala, K. C.

    2015-12-01

    Forbush decrease (FD) is an observed reduction in galactic cosmic ray (GCR) intensity as measured by ground neutron monitors often associated energetic events on the Sun such as coronal mass ejections (CME). FD is associated with increased activity of the sun as reflected in the size of the interplanetary coronal mass ejections passing around the Earth and the corotating regions in the Heliosphere. Since the interplanetary anisotropy evolves itself during a geomagnetic storm in addition to the reconfiguration of external magnetospheric currents, it is expected that changes in transmissivity of cosmic rays of galactic origin will occur during Geomagnetic storms. In this study we examine sixty-three (63) FD events and associated geomagnetic storms over the last three solar cycles from 1970 to 2013. The negative peaks of the FDs and the Dst coincided for most of the events (~70%). There was good correlation (>0.67) between the FDs and Dst. Signatures of influence of external magnetospheric currents on the count rates of the neutron monitors stations during periods of Forbush decreases (FDs) is provided. This evidence is observed as sudden increases in the count rates during the main phase of simultaneous FD. The magnitude of the sudden rise in the count rates of Neutron monitors and peak dst correlated well (>0.50) both for high latitude and mid latitude stations.

  4. Multi-Wavelength Variability. Accretion and Ejection at the Fastest Timescales

    CERN Document Server

    Uttley, Phil

    2015-01-01

    Multiwavelength variability data, combined with spectral-timing analysis techniques, provides information about the causal relationship between different physical components in accreting black holes. Using fast-timing data and long-term monitoring, we can probe the behaviour of the same components across the black hole mass scale. In this chapter we review the observational status of multiwavelength variability in accreting black holes, from black hole X-ray binaries to AGN, and consider the implications for models of accretion and ejection, primarily considering the evidence for accretion disc and jet variability in these systems. We end with a consideration of future prospects in this quickly-developing field.

  5. The Search for Stellar Coronal Mass Ejections

    Science.gov (United States)

    Villadsen, Jacqueline Rose

    2017-05-01

    Coronal mass ejections (CMEs) may dramatically impact habitability and atmospheric composition of planets around magnetically active stars, including young solar analogs and many M dwarfs. Theoretical predictions of such effects are limited by the lack of observations of stellar CMEs. This thesis addresses this gap through a search for the spectral and spatial radio signatures of CMEs on active M dwarfs. Solar CMEs produce radio bursts with a distinctive spectral signature, narrow-band plasma emission that drifts to lower frequency as a CME expands outward. To search for analogous events on nearby stars, I worked on system design, software, and commissioning for the Starburst project, a wideband single-baseline radio interferometry backend dedicated to stellar observations. In addition, I led a survey of nearby active M dwarfs with the Karl G. Jansky Very Large Array (VLA), detecting coherent radio bursts in 13 out of 23 epochs, over a total of 58 hours. This survey's ultra-wide bandwidth (0.23-6.0 GHz) dynamic spectroscopy, unprecedented for stellar observations, revealed diverse behavior in the time-frequency plane. Flare star UV Ceti produced complex, luminous events reminiscent of brown dwarf aurorae; AD Leo sustained long-duration, intense, narrow-band "storms"; and YZ CMi emitted a burst with substructure with rapid frequency drift, resembling solar Type III bursts, which are attributed to electrons moving at speeds of order 10% of the speed of light. To search for the spatial signature of CMEs, I led 8.5-GHz observations with the Very Long Baseline Array simultaneous to 24 hours of the VLA survey. This program detected non-thermal continuum emission from the stars in all epochs, as well as continuum flares on AD Leo and coherent bursts on UV Ceti, enabling measurement of the spatial offset between flaring and quiescent emission. These observations demonstrate the diversity of stellar transients that can be expected in time-domain radio surveys, especially

  6. The Search for Stellar Coronal Mass Ejections

    Science.gov (United States)

    Villadsen, Jacqueline; Hallinan, Gregg; Monroe, Ryan; Bourke, Stephen; Starburst Program Team

    2017-01-01

    Coronal mass ejections (CMEs) may dramatically impact habitability and atmospheric composition of planets around magnetically active stars, including young solar analogs and many M dwarfs. Theoretical predictions of such effects are limited by the lack of observations of stellar CMEs. My thesis addresses this gap through a search for the spectral and spatial radio signatures of CMEs on active M dwarfs.Solar CMEs produce radio bursts with a distinctive spectral signature, narrow-band plasma emission that drifts to lower frequency as a CME expands outward. To search for analogous events on nearby stars, I worked on system design, software, and commissioning for the Starburst project, a wideband single-baseline radio interferometry backend dedicated to stellar observations. In addition, I led a survey of nearby active M dwarfs with the Karl G. Jansky Very Large Array (JVLA), detecting 12 bright (>10 mJy) radio bursts in 58 hours. This survey’s ultra-wide bandwidth (0.23-6.0 GHz) dynamic spectroscopy, unprecedented for stellar observations, revealed diverse behavior in the time-frequency plane. Flare star UV Ceti produced complex, luminous events reminiscent of brown dwarf aurorae; AD Leo sustained long-duration, intense, narrow-band "storms"; and YZ CMi emitted a burst with substructure with rapid frequency drift, resembling solar Type III bursts, which are attributed to electrons moving at speeds of order 10% of the speed of light.To search for the spatial signature of CMEs, I led 8.5-GHz observations with the Very Long Baseline Array simultaneous to 24 hours of the JVLA survey. This program detected non-thermal continuum emission from the stars in all epochs, as well as continuum flares on AD Leo and coherent bursts on UV Ceti, enabling measurement of the spatial offset between flaring and quiescent emission.These observations demonstrate the diversity of stellar transients that can be expected in time-domain radio surveys, especially with the advent of large low

  7. COMPARATIVE STUDY OF HEART FAILURE WITH PRESERVED EJECTION FRACTION VERSUS DECREASED EJECTION FRACTION

    Directory of Open Access Journals (Sweden)

    Chandrashekar

    2015-03-01

    Full Text Available BACKGROUND AND OBJECTIVES : To study the socio demographic profile , risk factors , clinical presentation and comorbidies in patients with heart failure. To compare the socio demographic profile , risk factors , clinical presentation and comorbidities in patients with Heart failure with normal ejection fraction (HFnEF and Heart failure with reduced ejection fraction (HFrEF. METHODS: The primary study population consisted of 100 cases of adult men and women aged more than 18 years with symptoms of Hea rt failure diagnosed by Framingham’s criteria . The study population was selected from inpatients and outpatients attending Department of Medicine of KIMS hospital between January to December 2012. The study was a hospital based observatory and comparative study. RESULTS: Out of 100 cases included in our study 50% cases had HFrEF & 50% cases had HFnEF as confirmed by echocardiographic parameters. There was no statistically significant difference between the two groups with respect to age and sex. However the re were significant statistical significant differences between the groups with respect to clinical features , risk factors and co morbidities. Clinical features like oedema , hepatomegaly and rales were common in HFrEF group (P<0.05. Also LVESD & LVEDD wer e increased in patients with HFrEF. Risk factors like prior MI/IHD were more common in patients with HfrEF (P<0.05 . History of hypertension and left ventricular hypertrophy were common in patients with HFnEF (P< 0.05. Among the comorbidities: IHD Conduct ion abnormalities were common in HFrEF group. Pericardial effusion was more common in HFnEFgroup.

  8. Characterizing the original ejection velocity field of the Koronis family

    Science.gov (United States)

    Carruba, V.; Nesvorný, D.; Aljbaae, S.

    2016-06-01

    An asteroid family forms as a result of a collision between an impactor and a parent body. The fragments with ejection speeds higher than the escape velocity from the parent body can escape its gravitational pull. The cloud of escaping debris can be identified by the proximity of orbits in proper element, or frequency, domains. Obtaining estimates of the original ejection speed can provide valuable constraints on the physical processes occurring during collision, and used to calibrate impact simulations. Unfortunately, proper elements of asteroids families are modified by gravitational and non-gravitational effects, such as resonant dynamics, encounters with massive bodies, and the Yarkovsky effect, such that information on the original ejection speeds is often lost, especially for older, more evolved families. It has been recently suggested that the distribution in proper inclination of the Koronis family may have not been significantly perturbed by local dynamics, and that information on the component of the ejection velocity that is perpendicular to the orbital plane (vW), may still be available, at least in part. In this work we estimate the magnitude of the original ejection velocity speeds of Koronis members using the observed distribution in proper eccentricity and inclination, and accounting for the spread caused by dynamical effects. Our results show that (i) the spread in the original ejection speeds is, to within a 15% error, inversely proportional to the fragment size, and (ii) the minimum ejection velocity is of the order of 50 m/s, with larger values possible depending on the orbital configuration at the break-up.

  9. Anaesthetic management of laparoscopic surgery for rectal cancer in patients of dilated cardiomyopathy with poor ejection fraction: a case report

    Science.gov (United States)

    Wu, Yao-Hua; Hu, Liang; Xia, Jin; Hao, Quan-Shui; Feng, Li; Xiang, Hong-Bing

    2015-01-01

    A patient with dilated cardiomyopathy with poor ejection fraction posted for laparoscopic surgery for rectal cancer which was successfully performed under general anesthesia with endotracheal intubation and mechanical ventilation was reported. Our observations strongly indicate that detailed preoperative assessment, watchful intraoperative monitoring, and skillful optimization of fluid status and hemodynamic play important role in the high risk patient under general anesthesia with endotracheal intubation and mechanical ventilation. PMID:26309623

  10. Failure and Ejection Behavior of Concrete Materials under Internal Blast

    Directory of Open Access Journals (Sweden)

    Haifu Wang

    2016-01-01

    Full Text Available In order to investigate the failure and ejection behavior of concrete materials under internal blast, the default Riedel-Hiermaier-Thoma (RHT concrete model in AUTODYN and a meshfree processor called SPH are employed in this numerical simulation. It is shown that the failure mechanisms are significantly different in these damaged zones. Crushed zone is caused by shear failure while fractured zone is induced by tensile failure, and spalled zone is formed by a combination of shear and tensile failure. In addition, the ejection velocity distribution of the fragmented concrete mass on free surface is examined. The results indicate that the ejection velocity declines monotonously with the increase of the distance to symmetry axis of computational model. On the wall of the prefabricated borehole, two types of fragmented concrete mass are analyzed, and bottom initiation is recommended to eject the fragmented concrete mass effectively. Moreover, an algorithm of average ejection speed is developed to effectively estimate the drill capacity of high velocity, energetic (HE projectiles. At last, the validity of numerical simulation is verified by physical experiments.

  11. Analysis of melt ejection during long pulsed laser drilling

    Science.gov (United States)

    Ting-Zhong, Zhang; Zhi-Chao, Jia; Hai-Chao, Cui; De-Hua, Zhu; Xiao-Wu, Ni; Jian, Lu

    2016-05-01

    In pulsed laser drilling, melt ejection greatly influences the keyhole shape and its quality as well, but its mechanism has not been well understood. In this paper, numerical simulation and experimental investigations based on 304 stainless steel and aluminum targets are performed to study the effects of material parameters on melt ejection. The numerical method is employed to predict the temperatures, velocity fields in the solid, liquid, and vapour front, and melt pool dynamics of targets as well. The experimental methods include the shadow-graphic technique, weight method, and optical microscope imaging, which are applied to real-time observations of melt ejection phenomena, measurements of collected melt and changes of target mass, observations of surface morphology and the cross-section of the keyhole, respectively. Numerical and experimental results show that the metallic material with high thermal diffusivity like aluminum is prone to have a thick liquid zone and a large quantity of melt ejection. Additionally, to the best of our knowledge, the liquid zone is used to illustrate the relations between melt ejection and material thermal diffusivity for the first time. The research result in this paper is useful for manufacturing optimization and quality control in laser-material interaction. Project supported by the Natural Science Foundation of Jiangsu Province, China (Grant No. KYLX_0341) and the National Natural Science Foundation of China (Grant No. 61405147).

  12. Hypervelocity intracluster stars ejected by supermassive black hole binaries

    CERN Document Server

    Holley-Bockelmann, K; Mihos, J C; Feldmeier, J J; Ciardullo, R; McBride, C; Holley-Bockelmann, Kelly; Sigurdsson, Steinn; Feldmeier, John J.; Ciardullo, Robin; Bride, Cameron Mc

    2005-01-01

    Hypervelocity stars have been recently discovered in the outskirts of galaxies, such as the unbound star in the Milky Way halo, or the three anomalously fast intracluster planetary nebulae (ICPNe) in the Virgo Cluster. These may have been ejected by close 3-body interactions with a binary supermassive black hole (SMBBH), where a star which passes within the semimajor axis of the SMBBH can receive enough energy to eject it from the system. Stars ejected by SMBBHs may form a significant sub-population with very different kinematics and mean metallicity than the bulk of the intracluster stars. The number, kinematics, and orientation of the ejected stars may constrain the mass ratio, semimajor axis, and even the orbital plane of the SMBBH. We investigate the evolution of the ejected debris from a SMBBH within a clumpy and time-dependent cluster potential using a high resolution, self-consistent cosmological N-body simulation of a galaxy cluster. We show that the predicted number and kinematic signature of the fas...

  13. Ejection of gaseous clumps from gravitationally unstable protostellar disks

    CERN Document Server

    Vorobyov, Eduard I

    2016-01-01

    We investigate the dynamics of gaseous clumps formed via gravitational fragmentation in young protostellar disks, focusing on the fragments that are ejected from the disk via many-body gravitational interaction. Numerical hydrodynamics simulations were employed to study the evolution of young protostellar disks formed from the collapse of rotating pre-stellar cores with mass in the 1.1-1.6 M_sun range. Protostellar disks formed in our models undergo gravitational fragmentation driven by continuing mass loading from parental collapsing cores. A few fragments can be ejected from the disk during the early evolution, but the low-mass fragments (< 15~M_Jup) disperse creating spectacular bow-type structures while passing through the disk and collapsing core. The least massive fragment that survived the ejection (21 M_Jup) straddles the planetary-mass limit, while the most massive ejected fragments (145 M_Jup) can break up into several pieces, leading to the ejection of wide separation binary clumps in the brown-...

  14. Capstan friction model for DNA ejection from bacteriophages

    Science.gov (United States)

    Ghosal, Sandip

    2013-01-01

    Bacteriophages infect cells by attaching to the outer membrane and injecting their DNA into the cell. The phage DNA is then transcribed by the cell’s transcription machinery. A number of physical mechanisms by which DNA can be translocated from the phage capsid into the cell have been identified. A fast ejection driven by the elastic and electrostatic potential energy of the compacted DNA within the viral capsid appears to be used by most phages, at least to initiate infection. In recent in vitro experiments, the speed of DNA translocation from a λ phage capsid has been measured as a function of ejected length over the entire duration of the event. Here a mechanical model is proposed that is able to explain the observed dependence of exit velocity on ejected length, and that is also consistent with the accepted picture of the geometric arrangement of DNA within the viral capsid. PMID:23368388

  15. Constraints on the original ejection velocity fields of asteroid families

    CERN Document Server

    Carruba, Valerio

    2016-01-01

    Asteroid families form as a result of large-scale collisions among main belt asteroids. The orbital distribution of fragments after a family-forming impact could inform us about their ejection velocities. Unfortunately, however, orbits dynamically evolve by a number of effects, including the Yarkovsky drift, chaotic diffusion, and gravitational encounters with massive asteroids, such that it is difficult to infer the ejection velocities eons after each family's formation. Here we analyze the inclination distribution of asteroid families, because proper inclination can remain constant over long time intervals, and could help us to understand the distribution of the component of the ejection velocity that is perpendicular to the orbital plane ($v_{W}$). From modeling the initial breakup, we find that the distribution of $v_{W}$ of the fragments, which manage to escape the parent body's gravity, should be more peaked than a Gaussian distribution (i.e., be leptokurtic) even if the initial distribution was Gaussia...

  16. Characterizing the original ejection velocity field of the Koronis family

    CERN Document Server

    Carruba, Valerio; Aljbaae, Safwan

    2016-01-01

    An asteroid family forms as a result of a collision between an impactor and a parent body. The fragments with ejection speeds higher than the escape velocity from the parent body can escape its gravitational pull. The cloud of escaping debris can be identified by the proximity of orbits in proper element, or frequency, domains. Obtaining estimates of the original ejection speed can provide valuable constraints on the physical processes occurring during collision, and used to calibrate impact simulations. Unfortunately, proper elements of asteroids families are modified by gravitational and non-gravitational effects, such as resonant dynamics, encounters with massive bodies, and the Yarkovsky effect, such that information on the original ejection speeds is often lost, especially for older, more evolved families. It has been recently suggested that the distribution in proper inclination of the Koronis family may have not been significantly perturbed by local dynamics, and that information on the component of th...

  17. Capstan Friction Model for DNA Ejection from Bacteriophages

    Science.gov (United States)

    Ghosal, Sandip

    2012-12-01

    Bacteriophages infect cells by attaching to the outer membrane and injecting their DNA into the cell. The phage DNA is then transcribed by the cell’s transcription machinery. A number of physical mechanisms by which DNA can be translocated from the phage capsid into the cell have been identified. A fast ejection driven by the elastic and electrostatic potential energy of the compacted DNA within the viral capsid appears to be used by most phages, at least to initiate infection. In recent in vitro experiments, the speed of DNA translocation from a λ phage capsid has been measured as a function of ejected length over the entire duration of the event. Here, a mechanical model is proposed that is able to explain the observed dependence of exit velocity on ejected length, and that is also consistent with the accepted picture of the geometric arrangement of DNA within the viral capsid.

  18. Fluctuation Pressure Assisted Ejection of DNA From Bacteriophage

    CERN Document Server

    Harrison, Michael J

    2010-01-01

    The role of thermal pressure fluctuation excited within tightly packaged DNA prior to ejection from protein capsid shells is discussed in a model calculation. At equilibrium before ejection we assume the DNA is folded many times into a bundle of parallel segments that forms an equilibrium conformation at minimum free energy, which presses tightly against internal capsid walls. Using a canonical ensemble at temperature T we calculate internal pressure fluctuations against a slowly moving or static capsid mantle for an elastic continuum model of the folded DNA bundle. It is found that fluctuating pressure on the capsid internal wall from thermal excitation of longitudinal acoustic vibrations in the bundle may have root-mean-square values which are several tens of atmospheres for typically small phage dimensions. Comparisons are given with measured data on three mutants of lambda phage with different base pair lengths and total genome ejection pressures.

  19. Capstan friction model for DNA ejection from bacteriophages

    CERN Document Server

    Ghosal, Sandip

    2013-01-01

    Bacteriophages infect cells by attaching to the outer membrane and injecting their DNA into the cell.The phage DNA is then transcribed by the cell's transcription machinery.A number of physical mechanisms by which DNA can be translocated from the phage capsid into the cell have been identified. A fast ejection driven by the elastic and electrostatic potential energy of the compacted DNA within the viral capsid appears to be used by most phages, at least to initiate infection.In recent in vitro experiments, the speed of DNA translocation from a lambda phage capsid has been measured as a function of ejected length over the entire duration of the event.Here a mechanical model is proposed that is able to explain the observed dependence of exit velocity on ejected length, and that is also consistent with the accepted picture of the geometric arrangement of DNA within the viral capsid.

  20. Case of Acute Graft Failure during Suspected Humoral Rejection with Preserved Ejection Fraction, but Severely Reduced Longitudinal Deformation Detected by 2D-Speckle Tracking

    DEFF Research Database (Denmark)

    Clemmensen, Tor Skibsted; Eiskjær, Hans; Kofoed-Nielsen, Pernille B;

    2014-01-01

    remained unchanged, indicating need of more reliable noninvasive methods for graft function surveillance. Global longitudinal strain relates to clinical heart failure, filling pressure, and cardiac index during suspected humoral rejection and microvascular dysfunction in this HTX patient. We suggest...... routine monitoring of graft function by global longitudinal strain as supplement to routine left ventricular ejection fraction and diastolic Doppler measurements....

  1. The interplanetary mass ejections behaviour in the heliosphere

    CERN Document Server

    Dumitrache, Cristiana

    2014-01-01

    We present here an overview of an important solar phenomenon with major implication for space weather and planetary life. The coronal mass ejections (CMEs) come from the Sun and expand in the heliosphere, becoming interplanetary coronal mass ejections (ICMEs). They represent huge clouds of plasma and magnetic fields that travel with velocities reaching even 2000 km/s and perturbing the planetary and interplanetary field. The magnetic clouds (MC) are a special class of ICMEs. We summarize some aspects as the ICMEs identification, propagation and track back to the Sun, where the solar source could be found. We notice here few known catalogs of the ICMEs and magnetic clouds.

  2. Development of a Backpack Survival Kit for Ejection Seats.

    Science.gov (United States)

    1982-02-08

    7 AD-A113 653 NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AIRCRAFT -ETC F/6 6/7 DEVELOP04ENT OF A BACKPACK SURVIVAL KIT FOR EJECTION SEATS. (U) FEB...82 T J ZENOBI, 6 F WHITMAN UNCLASSIFIED NADC 22216 NL EEEEEE -EuJ REPORT NO. NADC-82024.60 DEVELOPMENT OF A BACKPACK SURVIVAL KIT FOR EJECTION SEATS...RECIPIENT’S CATALOG NUMBER NADC-82024-60 - I" J 4. TITLE (and Subtitle) S. TYPE OF REPORT A PERIOD COVERED Development of a Backpack Survival Kit Phase Report

  3. Diagnosis of heart failure with preserved ejection fraction.

    Science.gov (United States)

    Wachter, Rolf; Edelmann, Frank

    2014-07-01

    Heart failure with preserved ejection fraction (HFpEF) constitutes a growing health care burden worldwide. Although definitions vary somewhat among guidelines, in general the presence of typical heart failure symptoms and signs in combination with a preserved left ventricular ejection fraction (≥50%) and functional and/or structural left ventricular changes makes the diagnosis likely. This review focuses on the current understanding of diagnostic criteria, as presented in current guidelines and consensus recommendations, and on new insights from recent papers. The role of comorbidities that often contribute to symptoms and hamper the HFpEF diagnostics is also reviewed.

  4. Fentanyl iontophoretic transdermal system in postoperative pain management%芬太尼离子渗透经皮给药系统在术后疼痛治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    喻洁; 黄宇光

    2011-01-01

    背景 盐酸芬太尼离子渗透经皮给药系统(fentanyl Hcl iontophoretic transdermal system,fentanyl,ITS)是通过电离子渗透技术经体表的微弱电场由皮肤给予芬太尼,产生镇痛作用的给药装置.已在美国和欧洲批准上市,用于治疗中到重度的手术后疼痛.目的 主要回顾了在欧美针对该给药系统所进行的一系列临床试验.内容 安慰剂对照试验和阳性药物平行对照试验均证实,以离子渗透技术经皮给予芬太尼对多种手术后疼痛有良好的治疗作用.该给药系统具有与标准的吗啡患者自控镇痛(patient-controlled analgesia,PCA)相似的有效性和安全性.趋向 ITS具有无创,有效,安全,简单,易于为患者接受等优点,为临床提供了一种全新的PCA方式.%Background The fentanyl hydrochloride iontophoretic transdermal system(fentanyl ITS)is a needle-free,selfcontained drug-delivery system that uses iontophoretic technology to deliver fentanyl through the skin by application of a low-intensity electrical field.It has been approved in the USA and Europe for the management of acute,moderate-to-severe postoperative pain.Objective This review focus on several clinical trails of fentanyl ITS,which have been carried out in America and Europe.Content In three phase 3 placebo-controlled trials,fentanyl ITS was shown to be superior to placebo for the treatment of postoperative pain following major abdominal,orthopedic and thoracic surgery.The results of several active-comparator phase 3 trial demonstrated comparable safety and efficacy with a standard morphine intravenous patient-controlled analgesia(Ⅳ-PCA)dosing regimen,without significant difference in the side effect profile.Trend Fentanyl ITS is a novel patient-controlled analgesia(PCA)system allowing patients to self-administer pre-programmed doses of fentanyl.It represents a safe,easy to use,non-invasive and convenient alternative to current acute postoperative pain management modalities.

  5. Characterization of Boulders Ejected from Small Impact Craters

    NARCIS (Netherlands)

    Bart, G.D.; Melosh, H.J.; Strom, R.G.

    2004-01-01

    When an asteroid or comet impacts the surface of a solid body, some of the surface material is often ejected from the crater in the form of blocks. We are characterizing the size and location of such blocks around craters on the Moon and Mars. The lunar craters were observed in Lunar Orbiter III ima

  6. 78 FR 55137 - Federal Motor Vehicle Safety Standards; Ejection Mitigation

    Science.gov (United States)

    2013-09-09

    ... Part 571 Federal Motor Vehicle Safety Standards; Ejection Mitigation; Final Rule #0;#0;Federal Register... TRANSPORTATION National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AL40 Federal Motor Vehicle... document responds to petitions for reconsideration of a 2011 final rule that established Federal...

  7. Certain optimal parameters of high-velocity Venturi ejection tubes

    Science.gov (United States)

    Stark, S. B.; Reznichenko, I. G.; Pavlenko, Y. P.

    1984-11-01

    The influence of the geometrical characteristics of centrifugal nozzles in high velocity Venturi ejection tubes for atomizing liquid in gas cleaning plant is analyzed. An optimal value of the nozzle geometrical characteristic, which is a function of the degree of filling of the nozzle outlet opening by the liquid, is given, at which the throat length is independent of water pressure before the nozzle.

  8. Galectin-3 in heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    de Boer, Rudolf A.; Edelmann, Frank; Cohen-Solal, Alain; Mamas, Mamas A.; Maisel, Alan; Pieske, Burkert

    2013-01-01

    In the last decades it has been appreciated that many patients with heart failure (HF) suffer from HF with preserved ejection fraction (HFpEF). The diagnosis and treatment of HFpEF is difficult, as we lack specific markers of the disease and no specific treatments have been identified. Galectin-3 ha

  9. Characterization of Boulders Ejected from Small Impact Craters

    NARCIS (Netherlands)

    Bart, G.D.; Melosh, H.J.; Strom, R.G.

    2004-01-01

    When an asteroid or comet impacts the surface of a solid body, some of the surface material is often ejected from the crater in the form of blocks. We are characterizing the size and location of such blocks around craters on the Moon and Mars. The lunar craters were observed in Lunar Orbiter III ima

  10. The physics of accretion-ejection with LOFT

    CERN Document Server

    Casella, P; Coriat, M; Kalemci, E; Motta, S; Neilsen, J; Ponti, G; Begelman, M; Belloni, T; Koerding, E; Maccarone, T J; Petrucci, P -O; Rodriguez, J; Tomsick, J; Bhattacharyya, S; Bianchi, S; Del Santo, M; Donnarumma, I; Gandhi, P; Homan, J; Jonker, P; Kalamkar, M; Malzac, J; Markoff, S; Migliari, S; Miller, J; Miller-Jones, J; Poutanen, J; Remillard, R; Russell, D M; Uttley, P; Zdziarski, A

    2015-01-01

    This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of the physics of accretion and ejection around compact objects. For a summary, we refer to the paper.

  11. A Filament-Associated Halo Coronal Mass Ejection

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    There are only a few observations published so far that show the initiation of a coronal mass ejection (CME) and illustrate the magnetic changes in the surface origin of a CME. Any attempt to connect a CME with its local solar activities is meaningful. In this paper we present a clear instance of a halo CME initiation. A careful analysis of magnetograms shows that the only obvious magnetic changes in the surface region of the CME is a magnetic flux cancellation underneath a quiescent filament. The early disturbance was seen as the slow upward motion in segments of the quiescent filament. Four hours later, the filament was accelerated to about 50 km s-1 and erupted. While a small part of the material in the filament was ejected into the upper corona, most of the mass was transported to a nearby region. About forty minutes later, the transported mass was also ejected partially to the upper corona. The eruption of the filament triggered a two-ribbon flare, with post-flare loops connecting the flare ribbons. A halo CME, which is inferred to be associated with the eruptive filament, was observed from LASCO/C2 and C3. The halo CME contained two CME events, each event corresponded to a partial mass ejection of the filament. We suggest that the magnetic reconnection at the lower atmosphere is responsible for the filament eruption and the halo CME.

  12. Experimental Investigation of the Dispersion of Liquids by Ejection Atomizers

    Science.gov (United States)

    Arkhipov, V. A.; Bondarchuk, S. S.; Evsevleev, M. Ya.; Zharova, I. K.; Zhukov, A. S.; Zmanovskii, S. V.; Kozlov, E. A.; Konovalenko, A. I.; Trofimov, V. F.

    2013-11-01

    This paper presents the results of an experimental investigation of the dispersivity of liquid droplets in the spray cone of ejection atomizers. The calculational droplet size distribution function was measured by the method of low angles of the probe laser radiation scattering indicatrix on a pneumohydraulic bench under cold blow conditions. The efficiency of the proposed circuit designs of atomizers has been analyzed.

  13. Anomalous-plasmoid-ejection-induced secondary magnetic reconnection: modeling solar flares and coronal mass ejections by laser–plasma experiments

    Institute of Scientific and Technical Information of China (English)

    Quanli; Dong; Dawei; Yuan; Shoujun; Wang; Xun; Liu; Yutong; Li; Xiaoxuan; Lin; Huigang; Wei; Jiayong; Zhong; Shaoen; Jiang; Yongkun; Ding; Bobin; Jiang; Kai; Du; Yongjian; Tang; Mingyang; Yu; Xiantu; He; Neng; Hua; Zhanfeng; Qiao; Kuixi; Huang; Ming; Chen; Jianqiang; Zhu; Gang; Zhao; Zhengming; Sheng; Jie; Zhang

    2013-01-01

    The driving mechanism of solar flares and coronal mass ejections is a topic of ongoing debate, apart from the consensus that magnetic reconnection plays a key role during the impulsive process. While present solar research mostly depends on observations and theoretical models, laboratory experiments based on high-energy density facilities provide the third method for quantitatively comparing astrophysical observations and models with data achieved in experimental settings.In this article, we show laboratory modeling of solar flares and coronal mass ejections by constructing the magnetic reconnection system with two mutually approaching laser-produced plasmas circumfused of self-generated megagauss magnetic fields. Due to the Euler similarity between the laboratory and solar plasma systems, the present experiments demonstrate the morphological reproduction of flares and coronal mass ejections in solar observations in a scaled sense,and confirm the theory and model predictions about the current-sheet-born anomalous plasmoid as the initial stage of coronal mass ejections, and the behavior of moving-away plasmoid stretching the primary reconnected field lines into a secondary current sheet conjoined with two bright ridges identified as solar flares.

  14. Ejection-style self-imaging system design and finite element analysis for lunar lander

    Science.gov (United States)

    Li, Qi; Pan, Qifeng; Xu, Zhihai; Feng, Huajun

    2015-08-01

    Landing on surface of planet is the most direct and effective means of deep space exploration. Taking the picture of lander and surrounding environment can monitor the working status of the lander, and different exploration tasks arranged different imaging methods. Apollo 11 achieved manned lunar landing, so astronauts leaved lunar lander and installed imaging camera; Curiosity rover is equipped MAHLI (Mars Hand Lens Imager) at the end of the robot arm, and capture the own image of the rover; Chang'E-3 consists of lander and rover, which can captured image each other. In this paper, taking into account the working conditions without rover, we designed an ejection-style self-imaging apparatus for lunar lander, which consists of the optical imaging system, the tumbler structure body and the ejector body. Ejector body is mounted on the lunar lander to eject the imaging system to the appropriate distance. To make the image of lander in the center field of view, the imaging system needs to be installed on a tumbler structure body to ensure that the optical axis of imaging system can be adjusted to the direction toward the lander. We designed and developed the imaging optical system, the mechanical structure of tumbler body and ejector body, deduced reasonable compression spiral spring parameter according to the application requirements, and completed finite element analysis of tumbler structure body in the fall process. The experiments on the sand, soil and gravel ground verify the feasibility of the design scheme.

  15. Solar Radio Emission as a Prediction Technique for Coronal Mass Ejections' registration

    Science.gov (United States)

    Sheiner, Olga; Fridman, Vladimir

    2016-07-01

    The concept of solar Coronal Mass Ejections (CMEs) as global phenomenon of solar activity caused by the global magnetohydrodynamic processes is considered commonly accepted. These processes occur in different ranges of emission, primarily in the optical and the microwave emission being generated near the surface of the sun from a total of several thousand kilometers. The usage of radio-astronomical data for CMEs prediction is convenient and promising. Actually, spectral measurements of solar radio emission cover all heights of solar atmosphere, sensitivity and accuracy of measurements make it possible to record even small energy changes. Registration of the radio emission is provided by virtually all-weather ground-based observations, and there is the relative cheapness to obtain the corresponding information due to a developed system of monitoring observations. On the large statistical material there are established regularities of the existence of sporadic radio emission at the initial stage of CMEs' formation and propagation in the lower layers of the solar atmosphere during the time interval from 2-3 days to 2 hours before registration of CMEs on coronagraph. In this report we present the prediction algorithm and scheme of short-term forecasting developed on the base of statistical analysis regularities of solar radio emission data prior to "isolated" solar Coronal Mass Ejections registered in 1998, 2003, 2009-2013.

  16. Computer-based assessment of left ventricular regional ejection fraction in patients after myocardial infarction

    Science.gov (United States)

    Teo, S.-K.; Su, Y.; Tan, R. S.; Zhong, L.

    2014-03-01

    After myocardial infarction (MI), the left ventricle (LV) undergoes progressive remodeling which adversely affects heart function and may lead to development of heart failure. There is an escalating need to accurately depict the LV remodeling process for disease surveillance and monitoring of therapeutic efficacy. Current practice of using ejection fraction to quantitate LV function is less than ideal as it obscures regional variation and anomaly. Therefore, we sought to (i) develop a quantitative method to assess LV regional ejection fraction (REF) using a 16-segment method, and (ii) evaluate the effectiveness of REF in discriminating 10 patients 1-3 months after MI and 9 normal control (sex- and agematched) based on cardiac magnetic resonance (CMR) imaging. Late gadolinium enhancement (LGE) CMR scans were also acquired for the MI patients to assess scar extent. We observed that the REF at the basal, mid-cavity and apical regions for the patient group is significantly lower as compared to the control group (P infarction. The results suggest that REF could potentially be used as a discriminator for MI and employed to measure myocardium homogeneity with respect to degree of infarction. The computational performance per data sample took approximately 25 sec, which demonstrates its clinical potential as a real-time cardiac assessment tool.

  17. Ejection fractions and pressure-heart rate product to evaluate cardiac efficiency. Continuous, real-time diagnosis using blood pressure and heart rate.

    Science.gov (United States)

    Kunig, H; Tassani-Prell, P; Engelmann, L

    2014-04-01

    Ejection fractions, derived from ventricular volumes, and double product, related to myocardial oxygen consumption, are important diagnostic parameters, as they describe the efficiency with which oxygen is consumed. Present technology often allows only intermittent determination of physiological status. This deficiency may be overcome if ejection fractions and myocardial oxygen consumption could be determined from continuous blood pressure and heart rate measurements. The purpose of this study is to determine the viability of pressure-derived ejection fractions and pressure-heart rate data in a diverse patient population and the use of ejection fractions to monitor patient safety. Volume ejection fractions, derived from ventricular volumes, EF(V), are defined by the ratio of the difference of end-diastolic volume, EDV, and end-systolic volume, ESV, to EDV. In analogy, pressure ejection fraction, EF(P), may be defined by the ratio of the difference of systolic arterial pressure, SBP, and diastolic arterial pressure, DBP, to SBP. The pressure-heart rate (heart rate: HR) is given by the product of systolic pressure and heart rate, SBP × HR. EF(P) and SBP × HR data were derived for all patients (n = 824) who were admitted in 2008 to the ICU of a university hospital at the specific time 30 min prior to leaving the ICU whether as survivors or non-survivors. The results are displayed in an efficiency/pressure-heart rate diagram. The efficiency/pressure-heart rate diagram reveals one subarea populated exclusively by survivors, another subarea populated statistically significant by non-survivors, and a third area shared by survivors and non-survivors. The efficiency/pressure-heart rate product relationship may be used as an outcome criterion to assess survival and to noninvasively monitor improvement or deterioration in real time to improve safety in patients with diverse dysfunctions.

  18. Parallel Molecular Dynamics Simulations of Ejection from the Metal Cu and Al Under Shock Loading

    Institute of Scientific and Technical Information of China (English)

    CHEN Qi-Feng; CAO Xiao-Lin; ZHANG Ying; CAI Ling-Cang; CHEN Dong-Quan

    2005-01-01

    @@ Large-scale non-equilibrium molecular dynamics simulations are used to investigate the ejection of the metal under a shock loading. The present work focus on the dynamic process of ejection from the metal Cu and Al surface groove under shock loading, using parallel MD implementation and the Morse potential. The ejected mass coefficient and the size distribution of ejected particles (cluster for atoms) are investigated with changes of the half-angle or the depth of groove and shock strength.

  19. Deactivation in the rabbit left ventricle induced by constant ejection flow

    NARCIS (Netherlands)

    Wijkstra, Hessel; Boom, H.B.K.

    1989-01-01

    A study of pressure generated by the left ventricle after ejection with constant flow for different values of the ejection flow, flow duration, time of flow arrest, and ventricular volume is discussed. It was found that pressure after ejection, normalized with respect to isovolumic pressure, is

  20. Noncardiac Comorbidities in Heart Failure With Reduced Versus Preserved Ejection Fraction

    NARCIS (Netherlands)

    Mentz, Robert J.; Kelly, Jacob P.; von Lueder, Thomas G.; Voors, Adriaan A.; Lam, Carolyn S. P.; Cowie, Martin R.; Kjeldsen, Keld; Jankowska, Ewa A.; Atar, Dan; Butler, Javed; Fiuzat, Mona; Zannad, Faiez; Pitt, Bertram; O'Connor, Christopher M.

    2014-01-01

    Heart failure patients are classified by ejection fraction (EF) into distinct groups: heart failure with preserved ejection fraction (HFpEF) or heart failure with reduced ejection fraction (HFrEF). Although patients with heart failure commonly have multiple comorbidities that complicate management a

  1. Noncardiac Comorbidities in Heart Failure With Reduced Versus Preserved Ejection Fraction

    NARCIS (Netherlands)

    Mentz, Robert J.; Kelly, Jacob P.; von Lueder, Thomas G.; Voors, Adriaan A.; Lam, Carolyn S. P.; Cowie, Martin R.; Kjeldsen, Keld; Jankowska, Ewa A.; Atar, Dan; Butler, Javed; Fiuzat, Mona; Zannad, Faiez; Pitt, Bertram; O'Connor, Christopher M.

    2014-01-01

    Heart failure patients are classified by ejection fraction (EF) into distinct groups: heart failure with preserved ejection fraction (HFpEF) or heart failure with reduced ejection fraction (HFrEF). Although patients with heart failure commonly have multiple comorbidities that complicate management

  2. Deactivation in the rabbit left ventricle induced by constant ejection flow

    NARCIS (Netherlands)

    Wijkstra, Hessel; Boom, Herman B.K.

    1989-01-01

    A study of pressure generated by the left ventricle after ejection with constant flow for different values of the ejection flow, flow duration, time of flow arrest, and ventricular volume is discussed. It was found that pressure after ejection, normalized with respect to isovolumic pressure, is rege

  3. Pioglitazone-induced congestive heart failure and pulmonary edema in a patient with preserved ejection fraction.

    Science.gov (United States)

    Jearath, Vaneet; Vashisht, Rajan; Rustagi, Vipul; Raina, Sujeet; Sharma, Rajesh

    2016-01-01

    Pioglitazone-induced heart failure is known in patients with underlying heart disease, but is not well documented in patients with normal left ventricular function. Pioglitazone has been very popular as it is an insulin sensitizer and insulin resistance is prevalent among Indians. Fluid retention exacerbates pre-existing heart failure or precipitates heart failure in a patient with underlying left ventricular dysfunction. However, pathogenesis of heart failure in a patient with normal left ventricular function is not known. Probably it is due to dose-related effect on pulmonary endothelial permeability, rather than alterations in left ventricular mass or ejection fraction. We report a patient who developed congestive heart failure and pulmonary edema with normal left ventricular function within 1 year of starting pioglitazone therapy. We have to be careful in monitoring all possible side effects during followup when patients are on pioglitazone therapy.

  4. Pioglitazone-induced congestive heart failure and pulmonary edema in a patient with preserved ejection fraction

    Science.gov (United States)

    Jearath, Vaneet; Vashisht, Rajan; Rustagi, Vipul; Raina, Sujeet; Sharma, Rajesh

    2016-01-01

    Pioglitazone-induced heart failure is known in patients with underlying heart disease, but is not well documented in patients with normal left ventricular function. Pioglitazone has been very popular as it is an insulin sensitizer and insulin resistance is prevalent among Indians. Fluid retention exacerbates pre-existing heart failure or precipitates heart failure in a patient with underlying left ventricular dysfunction. However, pathogenesis of heart failure in a patient with normal left ventricular function is not known. Probably it is due to dose-related effect on pulmonary endothelial permeability, rather than alterations in left ventricular mass or ejection fraction. We report a patient who developed congestive heart failure and pulmonary edema with normal left ventricular function within 1 year of starting pioglitazone therapy. We have to be careful in monitoring all possible side effects during followup when patients are on pioglitazone therapy. PMID:27127397

  5. Pioglitazone-induced congestive heart failure and pulmonary edema in a patient with preserved ejection fraction

    Directory of Open Access Journals (Sweden)

    Vaneet Jearath

    2016-01-01

    Full Text Available Pioglitazone-induced heart failure is known in patients with underlying heart disease, but is not well documented in patients with normal left ventricular function. Pioglitazone has been very popular as it is an insulin sensitizer and insulin resistance is prevalent among Indians. Fluid retention exacerbates pre-existing heart failure or precipitates heart failure in a patient with underlying left ventricular dysfunction. However, pathogenesis of heart failure in a patient with normal left ventricular function is not known. Probably it is due to dose-related effect on pulmonary endothelial permeability, rather than alterations in left ventricular mass or ejection fraction. We report a patient who developed congestive heart failure and pulmonary edema with normal left ventricular function within 1 year of starting pioglitazone therapy. We have to be careful in monitoring all possible side effects during followup when patients are on pioglitazone therapy.

  6. Dynamics of bacteriophage genome ejection in vitro and in vivo

    Science.gov (United States)

    Panja, Debabrata; Molineux, Ian J.

    2010-12-01

    Bacteriophages, phages for short, are viruses of bacteria. The majority of phages contain a double-stranded DNA genome packaged in a capsid at a density of ~500 mg ml-1. This high density requires substantial compression of the normal B-form helix, leading to the conjecture that DNA in mature phage virions is under significant pressure, and that pressure is used to eject the DNA during infection. A large number of theoretical, computer simulation and in vitro experimental studies surrounding this conjecture have revealed many—though often isolated and/or contradictory—aspects of packaged DNA. This prompts us to present a unified view of the statistical physics and thermodynamics of DNA packaged in phage capsids. We argue that the DNA in a mature phage is in a (meta)stable state, wherein electrostatic self-repulsion is balanced by curvature stress due to confinement in the capsid. We show that in addition to the osmotic pressure associated with the packaged DNA and its counterions, there are four different pressures within the capsid: pressure on the DNA, hydrostatic pressure, the pressure experienced by the capsid and the pressure associated with the chemical potential of DNA ejection. Significantly, we analyze the mechanism of force transmission in the packaged DNA and demonstrate that the pressure on DNA is not important for ejection. We derive equations showing a strong hydrostatic pressure difference across the capsid shell. We propose that when a phage is triggered to eject by interaction with its receptor in vitro, the (thermodynamic) incentive of water molecules to enter the phage capsid flushes the DNA out of the capsid. In vivo, the difference between the osmotic pressures in the bacterial cell cytoplasm and the culture medium similarly results in a water flow that drags the DNA out of the capsid and into the bacterial cell.

  7. EUV and Coronagraphic Observations of Coronal Mass Ejections

    Indian Academy of Sciences (India)

    Durgesh Tripathi

    2006-06-01

    The Large Angle Spectrometric Coronagraph (LASCO) and Extreme-ultraviolet Imaging Telescope (EIT) onboard Solar and Heliospheric Observatory (SOHO) provide us with unprecedented multi-wavelength observations helping us to understand different dynamic phenomena on the Sun and in the corona. In this paper we discuss the association between post-eruptive arcades (PEAs) detected by EIT and white-light coronal mass ejections (CMEs) detected by LASCO/C2 telescope.

  8. Multinucleon Ejection Model for Two Body Current Neutrino Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Sobczyk, Jan T.; /Fermilab

    2012-06-01

    A model is proposed to describe nucleons ejected from a nucleus as a result of two-body-current neutrino interactions. The model can be easily implemented in Monte Carlo neutrino event generators. Various possibilities to measure the two-body-current contribution are discussed. The model can help identify genuine charge current quasielastic events and allow for a better determination of the systematic error on neutrino energy reconstruction in neutrino oscillation experiments.

  9. Characterization of Boulders Ejected from Small Impact Craters

    Science.gov (United States)

    Bart, G. D.; Melosh, H. J.; Strom, R. G.

    2004-11-01

    When an asteroid or comet impacts the surface of a solid body, some of the surface material is often ejected from the crater in the form of blocks. We are characterizing the size and location of such blocks around craters on the Moon and Mars. The lunar craters were observed in Lunar Orbiter III images from P-12 and S-18. The Mars crater was observed in Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) Release No. MOC2-712. The craters range in size from 300 m to 3 km diameter. We measured the diameters of boulders observed around the craters, and also measured the distance between the boulder and the crater center. We then calculate the ejection velocity of each boulder based on how far the block was from the crater. The data indicate that larger boulders are more frequently found close to the crater rim rather than far away. The size of the ejecta drops off as a power law with distance from the crater. Our results are consistent with studies by Vickery (1986, 1987), which indirectly found the distribution of ejecta sizes from large craters by analyzing the size and distribution of their secondary craters. Our work characterizes the other end of the ejecta spectrum --- low velocity boulders ejected from small craters. We have also constructed R-plots of the boulder diameters for each crater. We found that the R-plot for the boulders has a dependence remarkably similar to an R-plot of the diameters of secondary craters. This similarity supports the already accepted idea that the impactors that produce secondaries are blocks ejected from larger craters. It is also consistent with the interpretation that the upturn of the cratering curve at small diameters on the terrestrial planets is due to secondary impacts rather than a primary population as some have proposed.

  10. Phenotypic Spectrum of Heart Failure with Preserved Ejection Fraction

    OpenAIRE

    Sanjiv J Shah; Katz, Daniel H.; Rahul C Deo

    2014-01-01

    Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome, with several underlying etiologic and pathophysiologic factors. While prior heart failure clinical trials have used a “one size fits all” approach, this approach has not proven successful for HFpEF. Furthermore, with the aging population and epidemics of obesity, diabetes, and hypertension, the prevalence of HFpEF will continue to grow over the foreseeable future. Coupled with the high morbidity and mortality ...

  11. The Emerging Epidemic of Heart Failure with Preserved Ejection Fraction

    OpenAIRE

    Oktay, A. Afşin; Rich, Jonathan D.; Sanjiv J Shah

    2013-01-01

    Heart failure with preserved ejection fraction (HFpEF), which currently represents approximately 50 % of heart failure (HF) cases, is common and associated with high morbidity and mortality. Understanding the epidemiology of HFpEF has been difficult due to the challenges in HFpEF diagnosis and the heterogeneous etiologies and pathophysiologies that underlie HFpEF. Nevertheless, several high-quality epidemiology and observational registry studies of HFpEF demonstrate that an increasing prevale...

  12. Survivability rate among pilots in case of ejection

    Directory of Open Access Journals (Sweden)

    Alexandru GHEORGHIU

    2015-06-01

    Full Text Available The current paper presents a statistical analysis of a recent research made by the author [1], showing the factors causing the accidents that happened in Romanian Air Force from 1952 to 2014. Also the decision of ejection is analyzed. The study contains 225 events: 110 catastrophes and 115 accidents. 280 fighter pilots and 235 aircraft were involved in this analysis. The below information is a personal one and does not reflect an official position of the Ministry of National Defence.

  13. Mergers and ejections of black holes in globular clusters

    CERN Document Server

    Aarseth, Sverre

    2012-01-01

    We report on results of fully consistent N-body simulations of globular cluster models with N = 100 000 members containing neutron stars and black holes. Using the improved `algorithmic regularization' method of Hellstrom and Mikkola for compact subsystems, the new code NBODY7 enables for the first time general relativistic coalescence to be achieved for post-Newtonian terms and realistic parameters. Following an early stage of mass segregation, a few black holes form a small dense core which usually leads to the formation of one dominant binary. The subsequent evolution by dynamical shrinkage involves the competing processes of ejection and mergers by radiation energy loss. Unless the binary is ejected, long-lived triple systems often exhibit Kozai cycles with extremely high inner eccentricity (e > 0.999) which may terminate in coalescence at a few Schwarzschild radii. A characteristic feature is that ordinary stars as well as black holes and even BH binaries are ejected with high velocities. On the basis of...

  14. Episodic AGB Mass Ejection and the Creation of Fallback Shells

    CERN Document Server

    Chen, Zhuo; Blackman, Eric

    2015-01-01

    The short duration of mass ejection events during the Ascending Giant Branch (AGB) phase of stellar evolution can take different forms ranging thermal pulses to regular stellar pulsations. In most cases the shells ejected by the star are assumed to reach the escape velocity and expand into circumstellar space until they dissipate or merge with the surrounding gas. In this paper we investigate the case of an AGB star that emits a pulse of material below the escape velocity as may occur during a Common Envelope event. We explore the evolution of the shell created by this short mass loss event. We seek to determine when the shell falls back onto the star as opposed to being driven to escape velocity by the action of winds which occur after shell ejection. The problem is solved via 2.5D AMR AstroBEAR hydrodynamic simulations and a simplified one dimensional analytic model. We find that for given set of initial wind characteristics there is a critical shell velocity that distinguishes between shell fallback and sh...

  15. Droplet ejection and sliding on a flapping film

    Science.gov (United States)

    Chen, Xi; Doughramaji, Nicole; Betz, Amy Rachel; Derby, Melanie M.

    2017-03-01

    Water recovery and subsequent reuse are required for human consumption as well as industrial, and agriculture applications. Moist air streams, such as cooling tower plumes and fog, represent opportunities for water harvesting. In this work, we investigate a flapping mechanism to increase droplet shedding on thin, hydrophobic films for two vibrational cases (e.g., ± 9 mm and 11 Hz; ± 2 mm and 100 Hz). Two main mechanisms removed water droplets from the flapping film: vibrational-induced coalescence/sliding and droplet ejection from the surface. Vibrations mobilized droplets on the flapping film, increasing the probability of coalescence with neighboring droplets leading to faster droplet growth. Droplet departure sizes of 1-2 mm were observed for flapping films, compared to 3-4 mm on stationary films, which solely relied on gravity for droplet removal. Additionally, flapping films exhibited lower percentage area coverage by water after a few seconds. The second removal mechanism, droplet ejection was analyzed with respect to surface wave formation and inertia. Smaller droplets (e.g., 1-mm diameter) were ejected at a higher frequency which is associated with a higher acceleration. Kinetic energy of the water was the largest contributor to energy required to flap the film, and low energy inputs (i.e., 3.3 W/m2) were possible. Additionally, self-flapping films could enable novel water collection and condensation with minimal energy input.

  16. Pharmacotherapy of heart failure with preserved ejection fraction.

    Science.gov (United States)

    Basaraba, Jade E; Barry, Arden R

    2015-04-01

    Heart failure with preserved ejection fraction (HFpEF) constitutes ~50% of all heart failure diagnoses and is associated with considerable morbidity and mortality. The treatment of HFpEF can be challenging due to a lack of evidence supporting the benefit of various drug therapies. In practice, treatment can be divided into acute and chronic management. Acute therapy for decompensated heart failure is similar for both HFpEF and heart failure with reduced ejection fraction. The mainstay of treatment is diuretics to reduce volume overload and improve dyspnea. Patients with an acute exacerbation of HFpEF and rapid atrial fibrillation (AF) should be rate controlled with negative chronotropic agents. For chronic therapy, patients with HFpEF should not be treated like patients with heart failure with reduced ejection fraction. Chronic management of HFpEF can be simplified by using three strategies based on applicability: treat precipitating conditions (e.g., hypertension, AF), control symptoms by maintaining euvolemia with diuretics, and avoid therapies that have been shown not to be beneficial unless another compelling indication exists. Nondrug interventions for HFpEF include salt and fluid restriction, regular physical activity, and referral to a heart function clinic, if appropriate.

  17. Pathfinder landing sites at candidate SNC impact ejection sites

    Science.gov (United States)

    Golombek, Matthew P.

    1994-01-01

    If Mars Pathfinder were able to land at a site on Mars from which the SNC meteorites were ejected by impact, the Pathfinder mission would essentially represent a very inexpensive sample return mission. Geologic units that contain four potential impact craters from which SNC meteorites could have been ejected from Mars are accessible to the Mars Pathfinder lander. Determining that SNC meteorites came from a particular spot on Mars raises the intriguing possibility of using Pathfinder as a sample return mission and providing a radiometric age for the considerably uncertain martian crater-age timescale. Pathfinder instruments are capable of determining if the rock type at the landing site is similar to that of one or more of the SNC meteorites, which would strengthen the hypothesis that the SNC meteorites did, in fact, come from Mars. Unfortunately, instrument observations from Pathfinder are probably not capable of determining if the geologic unit sampled by the lander is definitively the unit from which a SNC meteorite came from as opposed to Mars in general or perhaps a particular region on Mars. This abstract evaluates the possibility of landing at potential SNC ejection sites and the ability of Pathfinder to identify the landing site as the place from which an SNC meteorite came.

  18. Photospheric magnetic field of an eroded-by-solar-wind coronal mass ejection

    Science.gov (United States)

    Palacios, J.; Cid, C.; Saiz, E.; Guerrero, A.

    2017-10-01

    We have investigated the case of a coronal mass ejection that was eroded by the fast wind of a coronal hole in the interplanetary medium. When a solar ejection takes place close to a coronal hole, the flux rope magnetic topology of the coronal mass ejection (CME) may become misshapen at 1 AU as a result of the interaction. Detailed analysis of this event reveals erosion of the interplanetary coronal mass ejection (ICME) magnetic field. In this communication, we study the photospheric magnetic roots of the coronal hole and the coronal mass ejection area with HMI/SDO magnetograms to define their magnetic characteristics.

  19. Maximum Velocity of a Boulder Ejected From an Impact Crater Formed on a Regolith Covered Surface

    Science.gov (United States)

    Bart, G. D.; Melosh, H. J.

    2007-12-01

    We investigate the effect of regolith depth on boulder ejection velocity. A "boulder" refers to an apparently intact rock or rock fragment lying on a planetary surface, regardless of emplacement mechanism. Boulders appear in planetary images as positive relief features --- bright, sun-facing pixels adjacent to dark, shadowed pixels. We studied 12 lunar craters in high resolution (1~m) photographs from Lunar Orbiter III and V. Local regolith depth was measured using the method of small crater morphology. Ejection velocities of boulders were calculated assuming a ballistic trajectory to the final boulder location. A plot of regolith depth/crater diameter vs. maximum boulder ejection velocity shows that craters formed in deeper regolith (with respect to crater size) eject boulders at lower velocities. When ejection velocity (EjV) is in m/s, and regolith depth (Dr) and crater diameter (Dc) are in meters, the data fit the relation Dr / Dc = 1053 × EjVmax-2.823. To explain the data, we turn to impact cratering theory. An ejected particle will follow a streamline from its place of origin to its ejection point (the Z-model), and then follow a ballistic trajectory. Material ejected along more shallow streamlines is ejected at greater velocities. If shallow regolith covers the surface, the most shallow (greatest velocity) streamlines will travel only through the regolith. Boulders, however, must be ejected from the bedrock below the regolith. Thus, the boulder ejected with the greatest velocity originates just below the regolith, along the most shallow streamline through the bedrock. If the regolith is deeper, the most shallow streamline through the bedrock will be deeper, and the maximum velocity of an ejected boulder will be lower. Hence, the regolith depth and maximum ejection velocity of a boulder are correlated: greater boulder ejection velocities correspond to thinner regolith. We observe this correlation in the data.

  20. EPISODIC EJECTION FROM ACTIVE ASTEROID 311P/PANSTARRS

    Energy Technology Data Exchange (ETDEWEB)

    Jewitt, David [Department of Earth and Space Sciences, University of California at Los Angeles, 595 Charles Young Drive East, Los Angeles, CA 90095-1567 (United States); Agarwal, Jessica [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Gottingen (Germany); Weaver, Harold [The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Mutchler, Max [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Larson, Stephen, E-mail: jewitt@ucla.edu [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Tucson AZ 85721-0092 (United States)

    2015-01-10

    We examine the development of the active asteroid 311P/PANSTARRS (formerly, 2013 P5) in the period from 2013 September to 2014 February using high resolution images from the Hubble Space Telescope. This multi-tailed object is characterized by a single, reddish nucleus of absolute magnitude H ≥ 18.98 ± 0.10, corresponding to an equal-area sphere of radius ≤200 ± 20 m (for assumed geometric albedo 0.29 ± 0.09). We set an upper limit to the radii of possible companion nuclei at ∼10 m. The nucleus ejected debris in nine discrete episodes, spread irregularly over a nine month interval, each time forming a distinct tail. Particles in the tails range from about 10 μm to at least 80 mm in radius, and were ejected at speeds <1 m s{sup –1}. The ratio of the total ejected dust mass to the nucleus mass is ∼3×10{sup –5}, corresponding to a global surface layer ∼2 mm thick, or to a deeper layer covering a smaller fraction of the surface. The observations are incompatible with an origin of the activity by impact or by the sublimation of entrapped ice. This object appears to be shedding its regolith by rotational (presumably YORP-driven) instability. Long-term fading of the photometry (months) is attributed to gradual dissipation of near-nucleus dust. Photometric variations on short timescales (<0.7 hr) are probably caused by fast rotation of the nucleus. However, because of limited time coverage and dilution of the nucleus signal by near-nucleus dust, we have not been able to determine the rotation period.

  1. Informed Heuristics for Guiding Stem-and-Cycle Ejection Chains

    CERN Document Server

    Harabor, Daniel

    2011-01-01

    The state of the art in local search for the Traveling Salesman Problem is dominated by ejection chain methods utilising the Stem-and-Cycle reference structure. Though effective such algorithms employ very little information in their successor selection strategy, typically seeking only to minimise the cost of a move. We propose an alternative approach inspired from the AI literature and show how an admissible heuristic can be used to guide successor selection. We undertake an empirical analysis and demonstrate that this technique often produces better results than less informed strategies albeit at the cost of running in higher polynomial time.

  2. Geoeffectiveness of Coronal Mass Ejections in the SOHO Era

    DEFF Research Database (Denmark)

    Dumbovic, M.; Devos, A.; Vrsnak, B.;

    2014-01-01

    The main objective of the study is to determine the probability distributions of the geomagnetic Dst index as a function of the coronal mass ejection (CME) and solar flare parameters for the purpose of establishing a probabilistic forecast tool for the geomagnetic storm intensity. Several CME...... and flare parameters as well as the effect of successive-CME occurrence in changing the probability for a certain range of Dst index values, were examined. The results confirm some of already known relationships between remotely-observed properties of solar eruptive events and geomagnetic storms, namely...

  3. Invasive hemodynamic characterization of heart failure with preserved ejection fraction

    DEFF Research Database (Denmark)

    Andersen, Mads Jønsson; Borlaug, Barry A

    2014-01-01

    Recent hemodynamic studies have advanced our understanding of heart failure with preserved ejection fraction (HFpEF). Despite improved pathophysiologic insight, clinical trials have failed to identify an effective treatment for HFpEF. Invasive hemodynamic assessment can diagnose or exclude HFpEF......, making it invaluable in understanding the basis of the disease. This article reviews the hemodynamic mechanisms underlying HFpEF and how they manifest clinically, discusses invasive hemodynamic assessment as a diagnostic tool, and explores how invasive hemodynamic profiling may allow understanding...

  4. Exercise physiology in heart failure and preserved ejection fraction.

    Science.gov (United States)

    Haykowsky, Mark J; Kitzman, Dalane W

    2014-07-01

    Recent advances in the pathophysiology of exercise intolerance in patients with heart failure with preserved ejection fraction (HFPEF) suggest that noncardiac peripheral factors contribute to the reduced peak V(o2) (peak exercise oxygen uptake) and to its improvement after endurance exercise training. A greater understanding of the peripheral skeletal muscle vascular adaptations that occur with physical conditioning may allow for tailored exercise rehabilitation programs. The identification of specific mechanisms that improve whole body and peripheral skeletal muscle oxygen uptake could establish potential therapeutic targets for medical therapies and a means to follow therapeutic response.

  5. Plasmoid ejections driven by dynamo action underneath a spherical surface

    CERN Document Server

    Warnecke, Jörn; Mitra, Dhrubaditya

    2010-01-01

    We present a unified three-dimensional model of the convection zone and upper atmosphere of the Sun in spherical geometry. In this model, magnetic fields, generated by a helically forced dynamo in the convection zone, emerge without the assistance of magnetic buoyancy. We use an isothermal equation of state with gravity and density stratification. Recurrent plasmoid ejections, which rise through the outer atmosphere, is observed. In addition, the current helicity of the small--scale field is transported outwards and form large structures like magnetic clouds.

  6. Epidemiology of heart failure with preserved ejection fraction

    DEFF Research Database (Denmark)

    Andersson, Charlotte; Vasan, Ramachandran S

    2014-01-01

    Heart failure with preserved ejection fraction (HFPEF) is a common condition, and the prevalence is projected to increase further. Studies differ in the reported incidence and mortality associated with this condition, although there is agreement that between a third and one-half of all patients...... with heart failure have HFPEF. Although several consensus statements and guidelines have been published, some recent randomized clinical trials have reported low mortality, raising doubts about whether all patients diagnosed with HFPEF have HFPEF or whether the condition is heterogeneous in its cause...

  7. Comparison of ejection events in the jet and accretion disc outflows in 3C 111

    Science.gov (United States)

    Tombesi, F.; Sambruna, R. M.; Marscher, A. P.; Jorstad, S. G.; Reynolds, C. S.; Markowitz, A.

    2012-07-01

    We present a comparison of the parameters of accretion disc outflows and the jet of the broad-line radio galaxy 3C 111 on subparsec (sub-pc) scales. We make use of published X-ray observations of ultra-fast outflows (UFOs) and new 43-GHz Very Long Baseline Array images to track the jet knot ejection. We find that the superluminal jet coexists with the mildly relativistic outflows on sub-pc scales, possibly indicating a transverse stratification of a global flow. The two are roughly in pressure equilibrium, with the UFOs potentially providing additional support for the initial jet collimation. The UFOs are much more massive than the jet, but their kinetic power is probably about an order of magnitude lower, at least for the observations considered here. However, their momentum flux is equivalent and both of them are powerful enough to exert a concurrent feedback impact on the surrounding environment. A link between these components is naturally predicted in the context of magnetohydrodynamic models for jet/outflow formation. However, given the high radiation throughput of active galactic nuclei, radiation pressure should also be taken into account. From the comparison with the long-term 2-10 keV Rossi X-ray Timing Explorer light curve, we find that the UFOs are preferentially detected during periods of increasing flux. We also find the possibility to place the UFOs within the known X-ray dips-jet ejection cycles, which has been shown to be a strong proof of the disc-jet connection, in analogue with stellar mass black holes. However, given the limited number of observations presently available, these relations are only tentative and additional spectral monitoring is needed to test them conclusively.

  8. Comparison of Ejection Events in the Jet and Accretion Disc Outflows in 3C 111

    Science.gov (United States)

    Tombesi, F.; Sambruna, R. M.; Marscher, A. P.; Jorstad, S. G.; Reynolds, C. S.; Markowtiz, A.

    2012-01-01

    We present a comparison of the parameters of accretion disc outflows and the jet of the broad-line radio galaxy 3C 111 on sub-pc scales. We make use of published X-ray observations of ultra-fast outflows (UFOs) and new 43 GHz VLBA images to track the jet knots ejection. We find that the superluminal jet coexists with the mildly relativistic outflows on sub-pc scales, possibly indicating a transverse stratification of a global flow. The two are roughly in pressure equilibrium, with the UFOs potentially providing additional support for the initial jet collimation. The UFOs are much more massive than the jet, but their kinetic power is probably about an order of magnitude lower, at least for the observations considered here. However, their momentum flux is equivalent and both of them are powerful enough to exert a concurrent feedback impact on the surrounding environment. A link between these components is naturally predicted in the context of MHD models for jet/outflow formation. However, given the high radiation throughput of AGNs, radiation pressure should also be taken into account. From the comparison with the long-term 2-10 keV RXTE light curve we find that the UFOs are preferentially detected during periods of increasing flux. We also find the possibility to place the UFOs within the known X-ray dips-jet ejection cycles, which has been shown to be a strong proof of the disc-jet connection, in analogue with stellar-mass black holes. However, given the limited number of observations presently available, these relations are only tentative and additional spectral monitoring is needed to test them conclusively.

  9. Dynamical mass ejection from black hole-neutron star binaries

    CERN Document Server

    Kyutoku, Koutarou; Okawa, Hirotada; Shibata, Masaru; Taniguchi, Keisuke

    2015-01-01

    We investigate properties of material ejected dynamically in the merger of black hole-neutron star binaries by numerical-relativity simulations. We systematically study dependence of ejecta properties on the mass ratio of the binary, spin of the black hole, and equation of state of the neutron-star matter. Dynamical mass ejection is driven primarily by tidal torque, and the ejecta is much more anisotropic than that from binary neutron star mergers. In particular, the dynamical ejecta is concentrated around the orbital plane with a half opening angle of 10deg--20deg and often sweeps only a half of the plane. The ejecta mass can be as large as ~0.1M_sun, and the velocity is subrelativistic with ~0.2--0.3c for typical cases. The ratio of the ejecta mass to the bound mass (disk and fallback components) becomes high and the ejecta velocity is large when the binary mass ratio is large, i.e., the black hole is massive. The remnant black hole-disk system receives a kick velocity of O(100)km/s due to the ejecta linear...

  10. Models for grains and gas ejection dynamics from a silo

    Science.gov (United States)

    Zhou, Yixian; Aussillous, Pascale; Ruyer, Pierre; Iusti/Gep Team; Semia/Limar Team

    2015-11-01

    In the hypothetical conditions of a reactivity initiated accident in a nuclear power plant, some of the fuel rods could break. If fuel fragmentation occurs, hot fuel particles and pressurized gas could interact with the surrounding fluid. The violence of this interaction depends on the discharge rate toward the fluid. In the present work, we study the discharge dynamics and identify the parameters governing this flow. In this paper, we focus on the experimental study of the discharge of a silo composed of spherical glass beads, with an orifice either lateral or at the bottom, with or without air flow. The measured parameters are the mass flow rate and the pressure along the silo, whereas the controlled parameters are the size of particles, the size of orifices, and the flow rate of air. For the case without air flow we found that the flow rate of particles ejected from the bottom orifice is 3 times greater than from the lateral orifice. For the case of a lateral orifice, when the form of the orifice is rectangular with width W and height D, we identify two regimes which depend on the ratio of width to height W / D . For the case with air flow, we found that the flow rate increases with the air flow. A simple physical model is proposed to describe the grains and gas ejection.

  11. Full Halo Coronal Mass Ejections: Arrival at the Earth

    CERN Document Server

    Shen, Chenglong; Pan, Zonghao; Miao, Bin; Ye, Pinzhong; Wang, S

    2014-01-01

    A geomagnetic storm is mainly caused by a front-side coronal mass ejection (CME) hitting the Earth and then interacting with the magnetosphere. However, not all front-side CMEs can hit the Earth. Thus, which CMEs hit the Earth and when they do so are important issues in the study and forecasting of space weather. In our previous work (Shen et al., 2013), the de-projected parameters of the full-halo coronal mass ejections (FHCMEs) that occurred from 2007 March 1 to 2012 May 31 were estimated, and there are 39 front-side events could be fitted by the GCS model. In this work, we continue to study whether and when these front-side FHCMEs (FFHCMEs) hit the Earth. It is found that 59\\% of these FFHCMEs hit the Earth, and for central events, whose deviation angles $\\epsilon$, which are the angles between the propagation direction and the Sun-Earth line, are smaller than 45 degrees, the fraction increases to 75\\%. After checking the deprojected angular widths of the CMEs, we found that all of the Earth-encountered CM...

  12. On the role of recombination in common-envelope ejections

    CERN Document Server

    Ivanova, N; Podsiadlowski, Ph

    2014-01-01

    The energy budget in common-envelope events (CEEs) is not well understood, with substantial uncertainty even over to what extent the recombination energy stored in ionised hydrogen and helium might be used to help envelope ejection. We investigate the reaction of a red-giant envelope to heating which mimics limiting cases of energy input provided by the orbital decay of a binary during a CEE, specifically during the post-plunge-in phase during which the spiral-in has been argued to occur on a time-scale longer than dynamical. We show that the outcome of such a CEE depends less on the total amount of energy by which the envelope is heated than on how rapidly the energy was transferred to the envelope and on where the envelope was heated. The envelope always becomes dynamically unstable before receiving net heat energy equal to the envelope's initial binding energy. We find two types of outcome, both of which likely lead to at least partial envelope ejection: "runaway" solutions in which the expansion of the ra...

  13. A Solar Coronal Jet Event Triggers A Coronal Mass Ejection

    CERN Document Server

    Liu, Jiajia; Shen, Chenglong; Liu, Kai; Pan, Zonghao; Wang, S

    2015-01-01

    We present the multi-point and multi-wavelength observation and analysis on a solar coronal jet and coronal mass ejection (CME) event in this paper. Employing the GCS model, we obtained the real (three-dimensional) heliocentric distance and direction of the CME and found it propagate in a high speed over 1000 km/s . The jet erupted before and shared the same source region with the CME. The temporal and spacial relation- ship between them guide us the possibility that the jet triggered the CME and became its core. This scenario could promisingly enrich our understanding on the triggering mechanism of coronal mass ejections and their relations with coronal large-scale jets. On the other hand, the magnetic field configuration of the source region observed by the SDO/HMI instrument and the off- limb inverse Y-shaped configuration observed by SDO/AIA 171 A passband, together provide the first detailed observation on the three-dimensional reconnection process of large-scale jets as simulated in Pariat et al. 2009. ...

  14. The initiation of coronal mass ejections by magnetic flux emergence

    Science.gov (United States)

    Dubey, G.; van der Holst, B.; Poedts, S.

    2006-12-01

    Aims.The initiation of solar Coronal Mass Ejections (CMEs) is studied in the framework of computational Magneto-Hydro-Dynamics (MHD). Methods: .The initial configuration includes a magnetic flux rope that is embedded in a gravitationally stratified solar atmosphere with a background dipole magnetic field in spherical, axi-symmetric geometry. The flux rope is in equilibrium due to an image current below the photosphere. An emerging magnetic flux triggering mechanism is used to make this equilibrium configuration unstable. Results: . When the magnetic flux emerges within the filament below the flux rope this results in a catastrophic behavior similar to earlier, more simple models. As a result, the flux rope rises and a current sheet forms below it. It is shown that the magnetic reconnection in the current sheet below the flux rope in combination with the outward curvature forces results in a fast ejection of the flux rope as observed for solar CMEs. We have done a parameter study of the effect of the flux emergence rate on the velocity and the acceleration of the resulting CMEs.

  15. Physical properties of erupting plasma associated with coronal mass ejections

    Science.gov (United States)

    Lee, J.; Raymond, J. C.; Reeves, K. K.; Moon, Y.; Kim, K.

    2013-12-01

    We investigate the physical properties (temperature, density, and mass) of erupting plasma observed in X-rays and EUV, which are all associated with coronal mass ejections observed by SOHO/LASCO. The erupting plasmas are observed as absorption or emission features in the low corona. The absorption feature provides a lower limit to the cold mass while the emission feature provides an upper limit to the mass of observed plasma in X-ray and EUV. We compare the mass constraints for each temperature response and find that the mass estimates in EUV and XRT are smaller than the total mass in the coronagraph. Several events were observed by a few passbands in the X-rays, which allows us to determine the temperature of the eruptive plasma using a filter ratio method. The temperature of one event is estimated at about 8.6 MK near the top of the erupting plasma. This measurement is possibly an average temperature for higher temperature plasma because the XRT is more sensitive at higher temperatures. In addition, a few events show that the absorption features of a prominence or a loop change to emission features with the beginning of their eruptions in all EUV wavelengths of SDO/AIA, which indicates the heating of the plasma. By estimating the physical properties of the erupting plasmas, we discuss the heating of the plasmas associated with coronal mass ejections in the low corona.

  16. Spontaneous Aerosol Ejection: Origin of Inorganic Particles in Biomass Pyrolysis.

    Science.gov (United States)

    Teixeira, Andrew R; Gantt, Rachel; Joseph, Kristeen E; Maduskar, Saurabh; Paulsen, Alex D; Krumm, Christoph; Zhu, Cheng; Dauenhauer, Paul J

    2016-06-08

    At high thermal flux and temperatures of approximately 500 °C, lignocellulosic biomass transforms to a reactive liquid intermediate before evaporating to condensable bio-oil for downstream upgrading to renewable fuels and chemicals. However, the existence of a fraction of nonvolatile compounds in condensed bio-oil diminishes the product quality and, in the case of inorganic materials, catalyzes undesirable aging reactions within bio-oil. In this study, ablative pyrolysis of crystalline cellulose was evaluated, with and without doped calcium, for the generation of inorganic-transporting aerosols by reactive boiling ejection from liquid intermediate cellulose. Aerosols were characterized by laser diffraction light scattering, inductively coupled plasma spectroscopy, and high-speed photography. Pyrolysis product fractionation revealed that approximately 3 % of the initial feed (both organic and inorganic) was transported to the gas phase as aerosols. Large bubble-to-aerosol size ratios and visualization of significant late-time ejections in the pyrolyzing cellulose suggest the formation of film bubbles in addition to the previously discovered jet formation mechanism.

  17. Ejection Dynamics in Vibration-Induced Droplet Atomization

    Science.gov (United States)

    Vukasinovic, Bojan; Smith, Marc K.; Glezer, Ari

    2001-11-01

    A primary sessile liquid drop is atomized into a fine spray of secondary droplets using vibration-induced atomization (VIDA) resulting from forced waves on a free surface of the primary drop. The mechanism of free surface breakup during the VIDA process is investigated using high-speed imaging and laser vibrometry. Secondary droplets result from a localized collapse of surface troughs and the ejection and ultimate breakup of momentary liquid spikes. The characteristic breakup time of these liquid spikes scales with the vibration period and the spike length initially varies like t0.5. The breakup begins with a capillary pinch-off from the tip of the spike that can be followed by additional pinching of liquid droplets. For relatively low-viscosity liquid (e.g., water) a capillary-wave instability of a jet is observed in some cases, while in very viscous liquid (e.g., glycerin-water solution) the first breakup occurs near the stem of the jet. The mechanisms of secondary droplet ejection and the influence of the operating parameters and fluid properties are discussed.

  18. Subdwarf B stars from the common envelope ejection channel

    CERN Document Server

    Xiong, H; Podsiadlowski, P; Han, Z

    2016-01-01

    From the canonical binary scenario, the majority of sdBs are produced from low-mass stars with degenerate cores where helium is ignited in a way of flashes. Due to numerical difficulties, the models of produced sdBs are generally constructed from more massive stars with non-degenerate cores, leaving several uncertainties on the exact characteristics of sdB stars. Employing MESA, we systematically studied the characteristics of sdBs produced from the common envelope (CE) ejection channel, and found that the sdB stars produced from the CE ejection channel appear to form two distinct groups on the effective temperature-gravity diagram. One group (the flash-mixing model) almost has no H-rich envelope and crows at the hottest temperature end of the extremely horizontal branch (EHB), while the other group has significant H-rich envelope and spreads over the whole canonical EHB region. The key factor for the dichotomy of the sdB properties is the development of convection during the first helium flash, which is dete...

  19. Right heart dysfunction in heart failure with preserved ejection fraction

    Science.gov (United States)

    Melenovsky, Vojtech; Hwang, Seok-Jae; Lin, Grace; Redfield, Margaret M.; Borlaug, Barry A.

    2014-01-01

    Aim Right heart function is not well characterized in patients with heart failure and preserved ejection fraction (HFpEF). The goal of this study was to examine the haemodynamic, clinical, and prognostic correlates of right ventricular dysfunction (RVD) in HFpEF. Methods and results Heart failure and preserved ejection fraction patients (n = 96) and controls (n = 46) underwent right heart catheterization, echocardiographic assessment, and follow-up. Right and left heart filling pressures, pulmonary artery (PA) pressures, and right-sided chamber dimensions were higher in HFpEF compared with controls, while left ventricular size and EF were similar. Right ventricular dysfunction (defined by RV fractional area change, FAC Right ventricular function was impaired in HFpEF compared with controls using both load-dependent (FAC: 40 ± 10 vs. 53 ± 7%, P Right heart dysfunction is common in HFpEF and is caused by both RV contractile impairment and afterload mismatch from pulmonary hypertension. Right ventricular dysfunction in HFpEF develops with increasing PA pressures, atrial fibrillation, male sex, and left ventricular dysfunction, and may represent a novel therapeutic target. PMID:24875795

  20. Dynamical Mass Ejection from Binary Neutron Star Mergers

    CERN Document Server

    Radice, David; Lippuner, Jonas; Roberts, Luke F; Ott, Christian D; Rezzolla, Luciano

    2016-01-01

    We present fully general-relativistic simulations of binary neutron star mergers with a temperature and composition dependent nuclear equation of state. We study the dynamical mass ejection from both quasi-circular and dynamical-capture eccentric mergers. We systematically vary the level of our treatment of the microphysics to isolate the effects of neutrino cooling and heating and we compute the nucleosynthetic yields of the ejecta. We find that eccentric binaries can eject significantly more material than quasi-circular binaries and generate bright infrared and radio emission. In all our simulations the outflow is composed of a combination of tidally- and shock-driven ejecta, mostly distributed over a broad $\\sim 60^\\circ$ angle from the orbital plane, and, to a lesser extent, by thermally driven winds at high latitudes. Ejecta from eccentric mergers are typically more neutron rich than those of quasi-circular mergers. This is the effect of the strong tidal torques exerted on the neutron stars during their ...

  1. Experimental Research on Influence of Some Factors on Ejection Height of Cargo Projectile

    Institute of Scientific and Technical Information of China (English)

    郁浩; 王晓天; 李欣; 李纪敏

    2012-01-01

    Some factors influencing the cargo projectile's ejection height in different conditions were analyzed by using harmonic curve diagram and cluster method.The test results of the ejection height for a certain cargo projectile show that the wind speed and direction are the main influence factors.For given meteorological conditions,the applied environmental stress becomes the main cause,while the launching angle does not influence the ejection height.

  2. Detection of Isotopes of Mercury Ions by Resonant Ejection in Paul Trap

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-Ming; SHE Lei; LI Jiao-Mei; GAO Ke-Lin

    2007-01-01

    A simple method to detect mercury ions confined in a Paul trap has been developed by resonant ejection. In this method, frequency of the additional ejection ac voltage is scanned instead of the amplitude of the rf drive voltage in conventional methods. It is possible not only to observe the spectra of the secular oscillation of the trapped ions directly, but also to eject the confined ions from the trap mass-selectively.

  3. Modeling MHD accretion-ejection: episodic ejections of jets triggered by a mean-field disk dynamo

    Energy Technology Data Exchange (ETDEWEB)

    Stepanovs, Deniss; Fendt, Christian; Sheikhnezami, Somayeh, E-mail: deniss@stepanovs.org, E-mail: fendt@mpia.de [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

    2014-11-20

    We present MHD simulations exploring the launching, acceleration, and collimation of jets and disk winds. The evolution of the disk structure is consistently taken into account. Extending our earlier studies, we now consider the self-generation of the magnetic field by an α{sup 2}Ω mean-field dynamo. The disk magnetization remains on a rather low level, which helps to evolve the simulations for T > 10, 000 dynamical time steps on a domain extending 1500 inner disk radii. We find the magnetic field of the inner disk to be similar to the commonly found open field structure, favoring magneto-centrifugal launching. The outer disk field is highly inclined and predominantly radial. Here, differential rotation induces a strong toroidal component, which plays a key role in outflow launching. These outflows from the outer disk are slower, denser, and less collimated. If the dynamo action is not quenched, magnetic flux is continuously generated, diffuses outward through the disk, and fills the entire disk. We have invented a toy model triggering a time-dependent mean-field dynamo. The duty cycles of this dynamo lead to episodic ejections on similar timescales. When the dynamo is suppressed as the magnetization falls below a critical value, the generation of the outflows and also accretion is inhibited. The general result is that we can steer episodic ejection and large-scale jet knots by a disk-intrinsic dynamo that is time-dependent and regenerates the jet-launching magnetic field.

  4. On interplanetary coronal mass ejection identification at 1 AU

    Science.gov (United States)

    Mulligan, T.; Russell, C. T.; Gosling, J. T.

    1999-06-01

    Coronal mass ejections are believed to be produced in the corona from closed magnetic regions not previously participating in the solar wind expansion. At 1 AU their interplanetary counterparts (ICMEs) generally have a number of distinct plasma and field signatures that distinguish them from the ambient solar wind. These include heat flux dropouts, bi-directional streaming, enhanced alpha particle events, times of depressed proton temperatures, intervals of distorted or enhanced magnetic field, and times of large magnetic field rotations characteristic of magnetic clouds. The first three of these signatures are phenomena that occur at some point within the ICME, but do not necessarily persist throughout the entire ICME. The large scale magnetic field rotations, distortions and enhancements, and the proton temperature depressions tend to mark more accurately the beginning and end of the ICME proper. We examine herein the reliability with which each of these markers identifies ICMEs utilizing ISEE-3 data from 1978-1980.

  5. An ice-cream cone model for coronal mass ejections

    Science.gov (United States)

    Xue, X. H.; Wang, C. B.; Dou, X. K.

    2005-08-01

    In this study, we use an ice-cream cone model to analyze the geometrical and kinematical properties of the coronal mass ejections (CMEs). Assuming that in the early phase CMEs propagate with near-constant speed and angular width, some useful properties of CMEs, namely the radial speed (v), the angular width (α), and the location at the heliosphere, can be obtained considering the geometrical shapes of a CME as an ice-cream cone. This model is improved by (1) using an ice-cream cone to show the near real configuration of a CME, (2) determining the radial speed via fitting the projected speeds calculated from the height-time relation in different azimuthal angles, (3) not only applying to halo CMEs but also applying to nonhalo CMEs.

  6. On Sun-to-Earth Propagation of Coronal Mass Ejections

    CERN Document Server

    Liu, Ying D; Lugaz, Noé; Möstl, Christian; Davies, Jackie A; Bale, Stuart D; Lin, Robert P

    2013-01-01

    We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation. Our comparison between different techniques (and data sets) also has important implications for CME observations and their interpretations. Future CME observations and space weather forecasting are discussed based on these results. See detail in the PDF.

  7. MHD Remote Numerical Simulations: Evolution of Coronal Mass Ejections

    CERN Document Server

    Hernandez-Cervantes, L; Gonzalez-Ponce, A R

    2008-01-01

    Coronal mass ejections (CMEs) are solar eruptions into interplanetary space of as much as a few billion tons of plasma, with embedded magnetic fields from the Sun's corona. These perturbations play a very important role in solar--terrestrial relations, in particular in the spaceweather. In this work we present some preliminary results of the software development at the Universidad Nacional Autonoma de Mexico to perform Remote MHD Numerical Simulations. This is done to study the evolution of the CMEs in the interplanetary medium through a Web-based interface and the results are store into a database. The new astrophysical computational tool is called the Mexican Virtual Solar Observatory (MVSO) and is aimed to create theoretical models that may be helpful in the interpretation of observational solar data.

  8. The Kinematics and Morphology of Solar Coronal Mass Ejections

    CERN Document Server

    Byrne, Jason P

    2012-01-01

    Solar coronal mass ejections (CMEs) are large-scale eruptions of plasma and magnetic field from the Sun into the corona and interplanetary space. They are the most significant drivers of adverse space weather at Earth and other locations in the heliosphere, so it is important to understand the physics governing their eruption and propagation. However the diffuse morphology and transient nature of CMEs makes them difficult to identify and track using traditional image processing techniques. In this thesis the implementation of multiscale image processing techniques to identify and track the CME front through coronagraph images is detailed. An ellipse characterisation of the CME front is used to determine the CME kinematics and morphology with increased precision as compared to techniques used in current CME catalogues, and efforts are underway to automate this procedure for applying to a large number of CME observations for future analysis. It was found that CMEs do not simply undergo constant acceleration, bu...

  9. Dynamo generated field emergence through recurrent plasmoid ejections

    CERN Document Server

    Warnecke, Jörn

    2010-01-01

    Magnetic buoyancy is believed to drive the transport of magnetic flux tubes from the convection zone to the surface of the Sun. The magnetic fields form twisted loop-like structures in the solar atmosphere. In this paper we use helical forcing to produce a large-scale dynamo-generated magnetic field, which rises even without magnetic buoyancy. A two layer system is used as computational domain where the upper part represents the solar atmosphere. Here, the evolution of the magnetic field is solved with the stress--and--relax method. Below this region a magnetic field is produced by a helical forcing function in the momentum equation, which leads to dynamo action. We find twisted magnetic fields emerging frequently to the outer layer, forming arch-like structures. In addition, recurrent plasmoid ejections can be found by looking at space--time diagrams of the magnetic field. Recent simulations in spherical coordinates show similar results.

  10. Flux Rope Formation Preceding Coronal Mass Ejection Onset

    CERN Document Server

    Green, L M

    2009-01-01

    We analyse the evolution of a sigmoidal (S shaped) active region toward eruption, which includes a coronal mass ejection (CME) but leaves part of the filament in place. The X-ray sigmoid is found to trace out three different magnetic topologies in succession: a highly sheared arcade of coronal loops in its long-lived phase, a bald-patch separatrix surface (BPSS) in the hours before the CME, and the first flare loops in its major transient intensity enhancement. The coronal evolution is driven by photospheric changes which involve the convergence and cancellation of flux elements under the sigmoid and filament. The data yield unambiguous evidence for the existence of a BPSS, and hence a flux rope, in the corona prior to the onset of the CME.

  11. Plasma Heating Suring a Coronal Mass Ejection Observed by SOHO

    CERN Document Server

    Murphy, N A; Korreck, K E

    2011-01-01

    We perform a time-dependent ionization analysis to constrain plasma heating requirements during a fast partial halo coronal mass ejection (CME) observed on 2000 June 28 by the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the Solar and Heliospheric Observatory (SOHO). We use two methods to derive densities from the UVCS measurements, including a density sensitive O V line ratio at 1213.85 and 1218.35 Angstroms, and radiative pumping of the O VI 1032,1038 doublet by chromospheric emission lines. The most strongly constrained feature shows cumulative plasma heating comparable to or greater than the kinetic energy, while features observed earlier during the event show cumulative plasma heating comparable to or less than the kinetic energy. SOHO Michelson Doppler Imager (MDI) observations are used to estimate the active region magnetic energy. We consider candidate plasma heating mechanisms and provide constraints when possible. Because this CME was associated with a relatively weak flare, the contribution b...

  12. Geoeffectiveness of Coronal Mass Ejections in the SOHO era

    CERN Document Server

    Dumbovic, Mateja; Vrsnak, Bojan; Sudar, Davor; Rodriguez, Luciano; Ruzdjak, Domagoj; Leer, Kristoffer; Vennerstrom, Susanne; Veronig, Astrid

    2014-01-01

    The main objective of the study is to determine the probability distributions of the geomagnetic Dst index as a function of the coronal mass ejection (CME) and solar flare parameters for the purpose of establishing a probabilistic forecast tool for the geomagnetic storm intensity. Several CME and flare parameters as well as the effect of successive-CME occurrence in changing the probability for a certain range of Dst index values, were examined. The results confirm some of already known relationships between remotely-observed properties of solar eruptive events and geomagnetic storms, namely the importance of initial CME speed, apparent width, source position, and the associated solar flare class. In this paper we quantify these relationships in a form to be used for space weather forecasting in future. The results of the statistical study are employed to construct an empirical statistical model for predicting the probability of the geomagnetic storm intensity based on remote solar observations of CMEs and fl...

  13. Application of particle trajectory model in 1D planar ejection

    Institute of Scientific and Technical Information of China (English)

    刘坤; 柏劲松; 李平

    2008-01-01

    A simple one-dimensional planar model for ejection was set up based on experiments.And numerical simulation was performed on this model with particle trajectory model method.An Eulerian finite volume method was conducted to resolve gas field.And Lagrangian method was imposed to track each particle.The interaction between gas and particles was responded as source terms in governing equations which were induced by forces.The effects of total spraying mass,particle size and other factors on the mixture of particles and gas were investigated.The spatial distributions of particle mass and velocity at different time were presented.The result shows that the numerical results are qualitatively consistent to those of experiments.

  14. Raman activated cell ejection for isolation of single cells.

    Science.gov (United States)

    Wang, Yun; Ji, Yuetong; Wharfe, Emma S; Meadows, Roger S; March, Peter; Goodacre, Royston; Xu, Jian; Huang, Wei E

    2013-11-19

    We have optimized a Raman microscope to obtain a single cell Raman spectrum (SCRS) with 0.1 s acquisition time. SCRS with such short acquisition time has sufficient discriminatory ability and spectral reproducibility to differentiate cells incorporated with (13)C and (15)N and to classify five different types of bacteria isolated from the oral cavity. We also developed Raman activated cell ejection (RACE) that is assisted by laser induced forward transfer (LIFT). We have shown, for the first time, that the single cells of interest can be identified and then accurately isolated from complex microbial communities based on their SCRS. This approach can be used to sort single cells of target traits from complex samples (e.g., biofilms, soils, sludge, tissues).

  15. Interplanetary Coronal Mass Ejections observed by MESSENGER and Venus Express

    CERN Document Server

    Good, S W

    2015-01-01

    Interplanetary coronal mass ejections (ICMEs) observed by the MESSENGER (MES) and Venus Express (VEX) spacecraft have been catalogued and analysed. The ICMEs were identified by a relatively smooth rotation of the magnetic field direction consistent with a flux rope structure, coinciding with a relatively enhanced magnetic field strength. A total of 35 ICMEs were found in the surveyed MES data (primarily from March 2007 to April 2012), and 84 ICMEs in the surveyed VEX data (from May 2006 to December 2013). The ICME flux rope configurations have been determined. Ropes with northward leading edges were about four times more common than ropes with southward leading edges, in agreement with a previously established solar cycle dependence. Ropes with low inclinations to the solar equatorial plane were about four times more common than ropes with high inclinations, possibly an observational effect. Left and right-handed ropes were observed in almost equal numbers. In addition, data from MES, VEX, STEREO-A, STEREO-B ...

  16. Final common envelope ejection by migration and jets

    CERN Document Server

    Soker, Noam

    2014-01-01

    I summarize recent analytical and numerical studies of the common envelope (CE) process and suggest to replace the commonly used alpha-prescription for the CE ejection by a prescription based on final migration and jets launched by the companion or the core of the giant stellar primary. In the migration process the core-companion binary systems is surrounded by a highly oblate (flatten) envelope, a thick circumbinary disk, formed by the large angular momentum transferred from the core-companion system to the envelope. I then show that the energy that can be released by an accreting main sequence companion can surpass the mutual gravitational energy of the core and the companion. An efficient channel to leash the accretion energy to expel the CE is through jets operating via a feedback mechanism (JFM).

  17. Close Binary Progenitors and Ejected Companions of Thermonuclear Supernovae

    Science.gov (United States)

    Geier, S.; Kupfer, T.; Heber, U.; Nemeth, P.; Ziegerer, E.; Irrgang, A.; Schindewolf, M.; Marsh, T. R.; Gänsicke, B. T.; Barlow, B. N.; Bloemen, S.

    2017-03-01

    Hot subdwarf stars (sdO/Bs) are evolved core helium-burning stars with very thin hydrogen envelopes, which can be formed by common envelope ejection. Close sdB binaries with massive white dwarf (WD) companions are potential progenitors of thermonuclear supernovae type Ia (SN Ia). We discovered such a progenitor candidate as well as a candidate for a surviving companion star, which escapes from the Galaxy. More candidates for both types of objects have been found by cross-matching known sdB stars with proper motion and light curve catalogues. We found 72 sdO/B candidates with high Galactic restframe velocities, 12 of them might be unbound to our Galaxy. Furthermore, we discovered the second-most compact sdB+WD binary known. However, due to the low mass of the WD companion, it is unlikely to be a SN Ia progenitor.

  18. Predicting Coronal Mass Ejections Using Machine Learning Methods

    CERN Document Server

    Bobra, Monica G

    2016-01-01

    Of all the activity observed on the Sun, two of the most energetic events are flares and Coronal Mass Ejections (CMEs). Usually, solar active regions that produce large flares will also produce a CME, but this is not always true (Yashiro et al., 2005). Despite advances in numerical modeling, it is still unclear which circumstances will produce a CME (Webb & Howard, 2012). Therefore, it is worthwhile to empirically determine which features distinguish flares associated with CMEs from flares that are not. At this time, no extensive study has used physically meaningful features of active regions to distinguish between these two populations. As such, we attempt to do so by using features derived from [1] photospheric vector magnetic field data taken by the Solar Dynamics Observatory's Helioseismic and Magnetic Imager instrument and [2] X-ray flux data from the Geostationary Operational Environmental Satellite's X-ray Flux instrument. We build a catalog of active regions that either produced both a flare and a...

  19. Heart failure with preserved ejection fraction: emerging drug strategies.

    Science.gov (United States)

    Zouein, Fouad A; de Castro Brás, Lisandra E; da Costa, Danielle V; Lindsey, Merry L; Kurdi, Mazen; Booz, George W

    2013-07-01

    Approximately half of heart failure patients have a normal ejection fraction, a condition designated as heart failure with preserved ejection fraction (HFpEF). This heart failure subtype disproportionately affects women and the elderly and is commonly associated with other cardiovascular comorbidities, such as hypertension and diabetes. HFpEF is increasing at a steady rate and is predicted to become the leading cause of heart failure within a decade. HFpEF is characterized by impaired diastolic function, thought to be due to concentric remodeling of the heart along with increased stiffness of both the extracellular matrix and myofilaments. In addition, oxidative stress and inflammation are thought to have a role in HFpEF progression, along with endothelial dysfunction and impaired nitric oxide-cyclic guanosine monophosphate-protein kinase G signaling. Surprisingly a number of clinical studies have failed to demonstrate any benefit of drugs effective in heart failure with systolic dysfunction in HFpEF patients. Thus, HFpEF is one of the largest unmet needs in cardiovascular medicine, and there is a substantial need for new therapeutic approaches and strategies that target mechanisms specific for HFpEF. This conclusion is underscored by the recently reported disappointing results of the RELAX trial, which assessed the use of phosphodiesterase-5 inhibitor sildenafil for treating HFpEF. In animal models, endothelial nitric oxide synthase activators and If current inhibitors have shown benefit in improving diastolic function, and there is a rationale for assessing matrix metalloproteinase 9 inhibitors and nitroxyl donors. LCZ696, a combination drug of angiotensin II receptor blocker and neprilysin inhibitor, and the aldosterone receptor antagonist spironolactone are currently in clinical trial for treating HFpEF. Here we present an overview of the etiology and diagnosis of HFpEF that segues into a discussion of new therapeutic approaches emerging from basic research and

  20. Episodic mass ejections from common-envelope objects

    Science.gov (United States)

    Clayton, Matthew; Podsiadlowski, Philipp; Ivanova, Natasha; Justham, Stephen

    2017-09-01

    After the initial fast spiral-in phase experienced by a common-envelope binary, the system may enter a slow, self-regulated phase, possibly lasting hundreds of years, in which all the energy released by orbital decay can be efficiently transported to the surface, where it is radiated away. If the remaining envelope is to be removed during this phase, this removal must occur through some as-yet-undetermined mechanism. We carried out 1D hydrodynamic simulations of a low-mass red giant undergoing a synthetic common-envelope event in such a slow spiral-in phase, using the stellar evolutionary code mesa. We simulated the heating of the envelope due to frictional dissipation from a binary companion's orbit in multiple configurations and investigated the response of the giant's envelope. We find that our model envelopes become dynamically unstable and develop large-amplitude pulsations, with periods in the range 3-20 yr and very short growth time-scales of similar order. The shocks and associated rebounds that emerge as these pulsations grow are in some cases strong enough to dynamically eject shells of matter of up to 0.1 M⊙, ∼10 per cent of the mass of the envelope, from the stellar surface at above escape velocity. These ejections are seen to repeat within a few decades, leading to a time-averaged mass-loss rate of the order of 10-3 M⊙ yr-1, which is sufficiently high to represent a candidate mechanism for removing the entire envelope over the duration of the slow spiral-in phase.

  1. Metabolomic fingerprint of heart failure with preserved ejection fraction.

    Directory of Open Access Journals (Sweden)

    Beshay N Zordoky

    Full Text Available Heart failure (HF with preserved ejection fraction (HFpEF is increasingly recognized as an important clinical entity. Preclinical studies have shown differences in the pathophysiology between HFpEF and HF with reduced ejection fraction (HFrEF. Therefore, we hypothesized that a systematic metabolomic analysis would reveal a novel metabolomic fingerprint of HFpEF that will help understand its pathophysiology and assist in establishing new biomarkers for its diagnosis.Ambulatory patients with clinical diagnosis of HFpEF (n = 24, HFrEF (n = 20, and age-matched non-HF controls (n = 38 were selected for metabolomic analysis as part of the Alberta HEART (Heart Failure Etiology and Analysis Research Team project. 181 serum metabolites were quantified by LC-MS/MS and 1H-NMR spectroscopy. Compared to non-HF control, HFpEF patients demonstrated higher serum concentrations of acylcarnitines, carnitine, creatinine, betaine, and amino acids; and lower levels of phosphatidylcholines, lysophosphatidylcholines, and sphingomyelins. Medium and long-chain acylcarnitines and ketone bodies were higher in HFpEF than HFrEF patients. Using logistic regression, two panels of metabolites were identified that can separate HFpEF patients from both non-HF controls and HFrEF patients with area under the receiver operating characteristic (ROC curves of 0.942 and 0.981, respectively.The metabolomics approach employed in this study identified a unique metabolomic fingerprint of HFpEF that is distinct from that of HFrEF. This metabolomic fingerprint has been utilized to identify two novel panels of metabolites that can separate HFpEF patients from both non-HF controls and HFrEF patients.ClinicalTrials.gov NCT02052804.

  2. Metabolomic Fingerprint of Heart Failure with Preserved Ejection Fraction

    Science.gov (United States)

    Zordoky, Beshay N.; Sung, Miranda M.; Ezekowitz, Justin; Mandal, Rupasri; Han, Beomsoo; Bjorndahl, Trent C.; Bouatra, Souhaila; Anderson, Todd; Oudit, Gavin Y.; Wishart, David S.; Dyck, Jason R. B.

    2015-01-01

    Background Heart failure (HF) with preserved ejection fraction (HFpEF) is increasingly recognized as an important clinical entity. Preclinical studies have shown differences in the pathophysiology between HFpEF and HF with reduced ejection fraction (HFrEF). Therefore, we hypothesized that a systematic metabolomic analysis would reveal a novel metabolomic fingerprint of HFpEF that will help understand its pathophysiology and assist in establishing new biomarkers for its diagnosis. Methods and Results Ambulatory patients with clinical diagnosis of HFpEF (n = 24), HFrEF (n = 20), and age-matched non-HF controls (n = 38) were selected for metabolomic analysis as part of the Alberta HEART (Heart Failure Etiology and Analysis Research Team) project. 181 serum metabolites were quantified by LC-MS/MS and 1H-NMR spectroscopy. Compared to non-HF control, HFpEF patients demonstrated higher serum concentrations of acylcarnitines, carnitine, creatinine, betaine, and amino acids; and lower levels of phosphatidylcholines, lysophosphatidylcholines, and sphingomyelins. Medium and long-chain acylcarnitines and ketone bodies were higher in HFpEF than HFrEF patients. Using logistic regression, two panels of metabolites were identified that can separate HFpEF patients from both non-HF controls and HFrEF patients with area under the receiver operating characteristic (ROC) curves of 0.942 and 0.981, respectively. Conclusions The metabolomics approach employed in this study identified a unique metabolomic fingerprint of HFpEF that is distinct from that of HFrEF. This metabolomic fingerprint has been utilized to identify two novel panels of metabolites that can separate HFpEF patients from both non-HF controls and HFrEF patients. Clinical Trial Registration ClinicalTrials.gov NCT02052804 PMID:26010610

  3. Dynamical mass ejection from binary neutron star mergers

    Science.gov (United States)

    Radice, David; Galeazzi, Filippo; Lippuner, Jonas; Roberts, Luke F.; Ott, Christian D.; Rezzolla, Luciano

    2016-08-01

    We present fully general-relativistic simulations of binary neutron star mergers with a temperature and composition dependent nuclear equation of state. We study the dynamical mass ejection from both quasi-circular and dynamical-capture eccentric mergers. We systematically vary the level of our treatment of the microphysics to isolate the effects of neutrino cooling and heating and we compute the nucleosynthetic yields of the ejecta. We find that eccentric binaries can eject significantly more material than quasi-circular binaries and generate bright infrared and radio emission. In all our simulations the outflow is composed of a combination of tidally- and shock-driven ejecta, mostly distributed over a broad ˜60° angle from the orbital plane, and, to a lesser extent, by thermally driven winds at high latitudes. Ejecta from eccentric mergers are typically more neutron rich than those of quasi-circular mergers. We find neutrino cooling and heating to affect, quantitatively and qualitatively, composition, morphology, and total mass of the outflows. This is also reflected in the infrared and radio signatures of the binary. The final nucleosynthetic yields of the ejecta are robust and insensitive to input physics or merger type in the regions of the second and third r-process peaks. The yields for elements on the first peak vary between our simulations, but none of our models is able to explain the Solar abundances of first-peak elements without invoking additional first-peak contributions from either neutrino and viscously-driven winds operating on longer time-scales after the mergers, or from core-collapse supernovae.

  4. The cardio-renal-anemia syndrome in elderly subjects with heart failure and a normal ejection fraction: a comparison with heart failure and low ejection fraction.

    Science.gov (United States)

    Cohen, Rose S; Mubashir, Asyia; Wajahat, Raja; Mani, Susan; Hummel, Scott; Maurer, Mathew S

    2006-01-01

    The prevalence and severity of anemia and renal dysfunction in heart failure patients with a normal ejection fraction (HFNEF) is uncharacterized. Two hundred eighty-five consecutive patients admitted to a community hospital with heart failure were stratified by the presence or absence of anemia and a normal or reduced ejection fraction. Comparisons of clinical variables were performed. In this sample, 62% of subjects were anemic, with no difference between those with a normal and a reduced ejection fraction (63% vs. 61%). Anemic HFNEF subjects had a lower glomerular filtration rate (37 +/- 21 mL/min vs. 52 +/- 35 mL/min; p renal dysfunction and anemia. The authors conclude that the degree and magnitude of anemia in elderly inpatients with heart failure does not differ by ejection fraction. Worse symptoms and more severe renal dysfunction were seen in HFNEF subjects with anemia than in HFNEF subjects without anemia.

  5. Space-time evolution of ejected plasma for the triggering of gas switch

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shanhong, E-mail: liushanhong108098@163.com; Liu, Xuandong; Shen, Xi; Feng, Lei; Zhang, Qiaogen [State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Institute of High Voltage Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Tie, Weihao [Xi' an Electrical Engineering Research Institute, Xi' an 710049 (China)

    2016-06-15

    Ejected plasma has been widely applied to the discharge process of gas spark switches as a trigger technology, and the development process of ejected plasma has a direct and important effect on the discharge characteristics of gas switches. In this paper, both the injection characteristics and space-time evolution of ejected plasma for the triggering of gas spark switch with different stored energies, pulse polarities, and pressures are studied. The discharge characteristics and breakdown process of a gas switch ignited by ejected plasma under different working coefficients are also discussed briefly. The results show that stored energy has significant influence on the characteristics of ejected plasma. With the increase of stored energy, the propulsion mode of ejected plasma in the axial direction transforms from “plasmoid” to “plasma flow,” and the distribution of the ejected plasma goes through “cloud,” “core-cloud,” and “branch” in sequence. The velocity of ejected plasma under negative pulse polarity is obviously higher than that under positive pulse polarity, especially at the very beginning time. The radial dimensions of ejected plasma under two kinds of pulse polarities follow the similar varying pattern over time, which increase first and then decrease, assuming an inverted “U”-shaped curve. With the increase of pressure, the velocity of ejected plasma significantly decreases and the “branch” channels droop earlier. Applying the ejected plasma to the triggering of a gas switch, the switch can be triggered reliably in a much wide working coefficient range of 10%–90%. With the increase of working coefficient, the breakdown process of the switch translates from slow working mode to fast working mode, and the delay time reduces from tens of μs to hundreds of ns.

  6. Space-time evolution of ejected plasma for the triggering of gas switch

    Science.gov (United States)

    Liu, Shanhong; Liu, Xuandong; Shen, Xi; Feng, Lei; Tie, Weihao; Zhang, Qiaogen

    2016-06-01

    Ejected plasma has been widely applied to the discharge process of gas spark switches as a trigger technology, and the development process of ejected plasma has a direct and important effect on the discharge characteristics of gas switches. In this paper, both the injection characteristics and space-time evolution of ejected plasma for the triggering of gas spark switch with different stored energies, pulse polarities, and pressures are studied. The discharge characteristics and breakdown process of a gas switch ignited by ejected plasma under different working coefficients are also discussed briefly. The results show that stored energy has significant influence on the characteristics of ejected plasma. With the increase of stored energy, the propulsion mode of ejected plasma in the axial direction transforms from "plasmoid" to "plasma flow," and the distribution of the ejected plasma goes through "cloud," "core-cloud," and "branch" in sequence. The velocity of ejected plasma under negative pulse polarity is obviously higher than that under positive pulse polarity, especially at the very beginning time. The radial dimensions of ejected plasma under two kinds of pulse polarities follow the similar varying pattern over time, which increase first and then decrease, assuming an inverted "U"-shaped curve. With the increase of pressure, the velocity of ejected plasma significantly decreases and the "branch" channels droop earlier. Applying the ejected plasma to the triggering of a gas switch, the switch can be triggered reliably in a much wide working coefficient range of 10%-90%. With the increase of working coefficient, the breakdown process of the switch translates from slow working mode to fast working mode, and the delay time reduces from tens of μs to hundreds of ns.

  7. Left ventricular dyssynchrony in patients with heart failure and preserved ejection fraction

    NARCIS (Netherlands)

    Santos, Angela B. S.; Kraigher-Krainer, Elisabeth; Bello, Natalie; Claggett, Brian; Zile, Michael R.; Pieske, Burkert; Voors, Adriaan A.; McMurray, John J. V.; Packer, Milton; Bransford, Toni; Lefkowitz, Marty; Shah, Amil M.; Solomon, Scott D.

    2014-01-01

    Aims Mechanical dyssynchrony has been postulated to play a pathophysiologic role in heart failure with preserved ejection fraction (HFpEF). Methods and results We quantified left ventricular (LV) systolic dyssynchrony in 130 HFpEF patients with NYHA class II-IV symptoms, ejection fraction (EF) 45, a

  8. Septum magnet for ejection from the PS to the E-Hall

    CERN Multimedia

    1977-01-01

    Pulsed septum magnet for ejection from PS straight sections 61/62 to the East-Hall. This septum magnet, for ss 61, had only 1 turn, for minimum thickness. It was followed by another septum in ss 62, with 2 turns, as there the ejected beam was already farther away from the circulating beam. Both septa were water-cooled.

  9. Imaging of the Ejection Process of Nanosecond Laser-induced forward Transfer of Gold

    NARCIS (Netherlands)

    Pohl, R.; Visser, C.W.; Römer, G.R.B.E.; Sun, C.; Huis in 't Veld, A.J.; Lohse, D.

    2015-01-01

    Laser-induced forward transfer is a direct-write process suitable for high precision 3D printing of several materials. However, the driving forces related to the ejection mechanism of the donor ma-terial are still under debate. To gain further insights into the ejection dynamics, this article presen

  10. Speeds of coronal mass ejections: SMM observations from 1980 and 1984-1989

    Science.gov (United States)

    Hundhausen, A. J.; Burkepile, J. T.; St. Cyr, O. C.

    1994-01-01

    The speeds of 936 features in 673 coronal mass ejections have been determined from trajectories observed with the Solar Maximum Mission (SMM) coronagraph in 1980 and 1984 to 1989. The distribution of observed speeds has a range (from 5th to 95th percentile) of 35 to 911 km/s; the average and median speeds are 349 and 285 km/s. The speed distributions of some selected classes of mass ejections are significantly different. For example, the speeds of 331 'outer loops' range from 80 to 1042 km/s; the average and median speeds for this class of ejections are 445 and 372 km/s. The speed distributions from each year of SMM observations show significant changes, with the annual average speeds varying from 157 (1984) to 458 km/s (1985). These variations are not simply related to the solar activity cycle; the annual averages from years near the sunspot maxima and minimum are not significantly different. The widths, latitudes, and speeds of mass ejections determined from the SMM observations are only weakly correlated. In particular, mass ejection speeds vary only slightly with the heliographic latitudes of the ejection. High-latitude ejections, which occur well poleward of the active latitudes, have speeds similar to active latitude ejections.

  11. Uniform description of polymer ejection dynamics from capsid with and without hydrodynamics

    Science.gov (United States)

    Piili, J.; Suhonen, P. M.; Linna, R. P.

    2017-05-01

    We use stochastic rotation dynamics (SRD) to examine the dynamics of the ejection of an initially strongly confined flexible polymer from a spherical capsid with and without hydrodynamics. The results obtained using stochastic rotation dynamics (SRD) are compared to similar Langevin simulations. Inclusion of hydrodynamic modes speeds up the ejection but also allows the part of the polymer outside the capsid to expand closer to equilibrium. This shows as higher values of radius of gyration when hydrodynamics are enabled. By examining the waiting times of individual polymer beads, we find that the waiting time tw grows with the number of ejected monomers s as a sum of two exponents. When ≈63 % of the polymer has ejected, the ejection enters the regime of slower dynamics. The functional form of tw versus s is universal for all ejection processes starting from the same initial monomer densities. Inclusion of hydrodynamics only reduces its magnitude. Consequently, we define a universal scaling function h such that the cumulative waiting time t =N0h (s /N0) for large N0. Our unprecedentedly precise measurements of force indicate that this form for tw(s ) originates from the corresponding force toward the pore decreasing superexponentially at the end of the ejection. Our measured tw(s ) explains the apparent superlinear scaling of the ejection time with the polymer length for short polymers. However, for asymptotically long polymers, tw(s ) predicts linear scaling.

  12. Heart failure with preserved ejection fraction in women : The dutch queen of hearts program

    NARCIS (Netherlands)

    den Ruijter, H.; Pasterkamp, G.; Rutten, F. H.; Lam, C. S P; Chi, C.; Tan, K. H.; van Zonneveld, A. J.; Spaanderman, M.; de Kleijn, D. P V

    2015-01-01

    Heart failure (HF) poses a heavy burden on patients, their families and society. The syndrome of HF comes in two types: with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). The latter is on the increase and predominantly present in women, especially the older ones. There i

  13. Ejection Regimes in Picosecond Laser-Induced Forward Transfer of Metals

    NARCIS (Netherlands)

    Pohl, Ralph; Visser, Claas Willem; Römer, Gert-Willem; Lohse, Detlef; Sun, Chao; Huis in 't Veld, Bert

    2015-01-01

    Laser-induced forward transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials, including pure metals. To understand the ejection mechanism and thereby improve deposition, here we present visualizations of ejection events at high-spatial (submicrometer) and hi

  14. Compressed wormlike chain moving out of confined space: A model of DNA ejection from bacteriophage

    Institute of Scientific and Technical Information of China (English)

    Ji-Zeng Wang; Long Li; Hua-Jian Gao

    2012-01-01

    The molecular biomechanics of DNA ejection from bacteriophage is of interest to not only fundamental biological understandings but also practical applications such as the design of advanced site-specific and controllable drug delivery systems.In this paper,we analyze the viscous motion of a semiflexible polymer chain coming out of a strongly confined space as a model to investigate the effects of various structure confinements and frictional resistances encountered during the DNA ejection process.The theoretically predicted relations between the ejection speed,ejection time,ejection length,and other physical parameters,such as the phage type,total genome length and ionic state of external buffer solutions,show excellent agreement with in vitro experimental observations in the literature.

  15. Sizes and locations of coronal mass ejections - SMM observations from 1980 and 1984-1989

    Science.gov (United States)

    Hundhausen, A. J.

    1993-01-01

    A statistical description of the sizes and locations of 1209 mass ejections observed with the SMM coronagraph/polarimeter in 1980 and 1984-1989 is presented. The average width of the coronal mass ejections detected with this instrument was close to 40 deg in angle for the entire period of SMM observations. No evidence was found for a significant change in mass ejection widths as reported by Howard et al. (1986). There is clear evidence for changes in the latitude distribution of mass ejections over this epoch. Mass ejections occurred over a much wider range of latitudes at the times of high solar activity (1980 and 1989) than at times of low activity (1985-1986).

  16. Two billion years of magmatism recorded from a single Mars meteorite ejection site

    Science.gov (United States)

    Lapen, Thomas J.; Righter, Minako; Andreasen, Rasmus; Irving, Anthony J.; Satkoski, Aaron M.; Beard, Brian L.; Nishiizumi, Kunihiko; Jull, A. J. Timothy; Caffee, Marc W.

    2017-01-01

    The timing and nature of igneous activity recorded at a single Mars ejection site can be determined from the isotope analyses of Martian meteorites. Northwest Africa (NWA) 7635 has an Sm-Nd crystallization age of 2.403 ± 0.140 billion years, and isotope data indicate that it is derived from an incompatible trace element–depleted mantle source similar to that which produced a geochemically distinct group of 327- to 574-million-year-old “depleted” shergottites. Cosmogenic nuclide data demonstrate that NWA 7635 was ejected from Mars 1.1 million years ago (Ma), as were at least 10 other depleted shergottites. The shared ejection age is consistent with a common ejection site for these meteorites. The spatial association of 327- to 2403-Ma depleted shergottites indicates >2 billion years of magmatism from a long-lived and geochemically distinct volcanic center near the ejection site. PMID:28164153

  17. Type Ia supernova bolometric light curves and ejected mass estimates from the Nearby Supernova Factory

    CERN Document Server

    Scalzo, R; Antilogus, P; Aragon, C; Bailey, S; Baltay, C; Bongard, S; Buton, C; Cellier-Holzem, F; Childress, M; Chotard, N; Copin, Y; Fakhouri, H K; Gangler, E; Guy, J; Kim, A; Kowalski, M; Kromer, M; Nordin, J; Nugent, P; Paech, K; Pain, R; Pecontal, E; Pereira, R; Perlmutter, S; Rabinowitz, D; Rigault, M; Runge, K; Saunders, C; Sim, S A; Smadja, G; Tao, C; Taubenberger, S; Thomas, R C; Weaver, B A

    2014-01-01

    We present a sample of normal type Ia supernovae from the Nearby Supernova Factory dataset with spectrophotometry at sufficiently late phases to estimate the ejected mass using the bolometric light curve. We measure $^{56}$Ni masses from the peak bolometric luminosity, then compare the luminosity in the $^{56}$Co-decay tail to the expected rate of radioactive energy re- lease from ejecta of a given mass. We infer the ejected mass in a Bayesian context using a semi-analytic model of the ejecta, incorporating constraints from contemporary numerical models as priors on the density structure and distribution of $^{56}$Ni throughout the ejecta. We find a strong correlation between ejected mass and light curve decline rate, and consequently $^{56}$Ni mass, with ejected masses in our data ranging from 0.9-1.4 $M_\\odot$. Most fast-declining (SALT2 $x_1 < -1$) normal SNe Ia have significantly sub-Chandrasekhar ejected masses in our fiducial analysis.

  18. Femtosecond pulse-width dependent trapping and directional ejection dynamics of dielectric nanoparticles

    KAUST Repository

    Chiang, Weiyi

    2013-09-19

    We demonstrate that laser pulse duration, which determines its impulsive peak power, is an effective parameter to control the number of optically trapped dielectric nanoparticles, their ejections along the directions perpendicular to polarization vector, and their migration distances from the trapping site. This ability to controllably confine and eject the nanoparticle is explained by pulse width-dependent optical forces exerted on nanoparticles in the trapping site and ratio between the repulsive and attractive forces. We also show that the directional ejections occur only when the number of nanoparticles confined in the trapping site exceeds a definite threshold. We interpret our data by considering the formation of transient assembly of the optically confined nanoparticles, partial ejection of the assembly, and subsequent filling of the trapping site. The understanding of optical trapping and directional ejections by ultrashort laser pulses paves the way to optically controlled manipulation and sorting of nanoparticles. © 2013 American Chemical Society.

  19. Right Ventricular Ejection Fraction Is Incremental to Left Ventricular Ejection Fraction for the Prediction of Future Arrhythmic Events in Patients With Systolic Dysfunction.

    Science.gov (United States)

    Mikami, Yoko; Jolly, Umjeet; Heydari, Bobak; Peng, Mingkai; Almehmadi, Fahad; Zahrani, Mohammed; Bokhari, Mahmoud; Stirrat, John; Lydell, Carmen P; Howarth, Andrew G; Yee, Raymond; White, James A

    2017-01-01

    Left ventricular ejection fraction remains the primary risk stratification tool used in the selection of patients for implantable cardioverter defibrillator therapy. However, this solitary marker fails to identify a substantial portion of patients experiencing sudden cardiac arrest. In this study, we examined the incremental value of considering right ventricular ejection fraction for the prediction of future arrhythmic events in patients with systolic dysfunction using the gold standard of cardiovascular magnetic resonance. Three hundred fourteen consecutive patients with ischemic cardiomyopathy or nonischemic dilated cardiomyopathy undergoing cardiovascular magnetic resonance were followed for the primary outcome of sudden cardiac arrest or appropriate implantable cardioverter defibrillator therapy. Blinded quantification of left ventricular and right ventricular (RV) volumes was performed from standard cine imaging. Quantification of fibrosis from late gadolinium enhancement imaging was incrementally performed. RV dysfunction was defined as right ventricular ejection fraction ≤45%. Among all patients (164 ischemic cardiomyopathy, 150 nonischemic dilated cardiomyopathy), the mean left ventricular ejection fraction was 32±12% (range, 6-54%) with mean right ventricular ejection fraction of 48±15% (range, 7-78%). At a median of 773 days, 49 patients (15.6%) experienced the primary outcome (9 sudden cardiac arrest, 40 appropriate implantable cardioverter defibrillator therapies). RV dysfunction was independently predictive of the primary outcome (hazard ratio=2.98; P=0.002). Among those with a left ventricular ejection fraction >35% (N=121; mean left ventricular ejection fraction, 45±6%), RV dysfunction provided an adjusted hazard ratio of 4.2 (P=0.02). RV dysfunction is a strong, independent predictor of arrhythmic events. Among patients with mild to moderate LV dysfunction, a cohort greatly contributing to global sudden cardiac arrest burden, this marker

  20. Coronal ``Wave'': Magnetic Footprint of a Coronal Mass Ejection?

    Science.gov (United States)

    Attrill, Gemma D. R.; Harra, Louise K.; van Driel-Gesztelyi, Lidia; Démoulin, Pascal

    2007-02-01

    We investigate the properties of two ``classical'' EUV Imaging Telescope (EIT) coronal waves. The two source regions of the associated coronal mass ejections (CMEs) possess opposite helicities, and the coronal waves display rotations in opposite senses. We observe deep core dimmings near the flare site and also widespread diffuse dimming, accompanying the expansion of the EIT wave. We also report a new property of these EIT waves, namely, that they display dual brightenings: persistent ones at the outermost edge of the core dimming regions and simultaneously diffuse brightenings constituting the leading edge of the coronal wave, surrounding the expanding diffuse dimmings. We show that such behavior is consistent with a diffuse EIT wave being the magnetic footprint of a CME. We propose a new mechanism where driven magnetic reconnections between the skirt of the expanding CME magnetic field and quiet-Sun magnetic loops generate the observed bright diffuse front. The dual brightenings and the widespread diffuse dimming are identified as innate characteristics of this process.

  1. Global Energetics of Solar Flares: IV. Coronal Mass Ejection Energetics

    CERN Document Server

    Aschwanden, Markus J

    2016-01-01

    This study entails the fourth part of a global flare energetics project, in which the mass $m_{\\mathrm{cme}}$, kinetic energy $E_{\\mathrm{kin}}$, and the gravitational potential energy $E_{\\mathrm{grav}}$ of coronal mass ejections (CMEs) is measured in 399 M and X-class flare events observed during the first 3.5 yrs of the Solar Dynamics Observatory (SDO) mission, using a new method based on the EUV dimming effect. The EUV dimming is modeled in terms of a radial adiabatic expansion process, which is fitted to the observed evolution of the total emission measure of the CME source region. The model derives the evolution of the mean electron density, the emission measure, the bulk plasma expansion velocity, the mass, and the energy in the CME source region. The EUV dimming method is truly complementary to the Thomson scattering method in white light, which probes the CME evolution in the heliosphere at $r > 2 R_{\\odot}$, while the EUV dimming method tracks the CME launch in the corona. We compare the CME paramet...

  2. Coronal mass ejections and geomagnetic storms: Seasonal variations

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, J.L.; Gosling, J.T.; McComas, D.J.

    1992-07-01

    The well-established semiannual geomagnetic cycle, with peak activity near the equinoxes, has been attributed to the angle between the solar rotation axis and the geomagnetic dipole, which modulates the GSM Bz component in the interplanetary magnetic field (MF). This effect is predicted to be accentuated in the shocked plasma ahead of fast coronal mass ejections (CMESs); its relevance to the internal fields of the ejecta is unclear. CMEs, particularly fast events driving interplanetary shocks, are the cause of almost all large geomagnetic storms near solar maximum. We use a set of CMEs identified by ISEE-3 observations of bidirectional electron streaming, plus IMF and geomagnetic data, to investigate the semiannual geomagnetic variation and its relation to CMEs. We find that the geomagnetic effectiveness of CMEs and post-shock solar wind is well-ordered by speed and by the southward component of the IMF in GSM coordinates, as well as by preexisting geomagnetic conditions. The post-shock seasonal effect, with geomagnetic effectiveness maximizing near April 5 for negative GSEQ By and near October 5 for positive GSEQ By, is identifiable in shock and shock/CME events, but not for CME events without leading shocks. When used to complement the more fundamental causal parameter of CME speed, the seasonal effect appears to have value for prediction of geomagnetic storms.

  3. Coronal mass ejections and geomagnetic storms: Seasonal variations

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, J.L.; Gosling, J.T.; McComas, D.J.

    1992-01-01

    The well-established semiannual geomagnetic cycle, with peak activity near the equinoxes, has been attributed to the angle between the solar rotation axis and the geomagnetic dipole, which modulates the GSM Bz component in the interplanetary magnetic field (MF). This effect is predicted to be accentuated in the shocked plasma ahead of fast coronal mass ejections (CMESs); its relevance to the internal fields of the ejecta is unclear. CMEs, particularly fast events driving interplanetary shocks, are the cause of almost all large geomagnetic storms near solar maximum. We use a set of CMEs identified by ISEE-3 observations of bidirectional electron streaming, plus IMF and geomagnetic data, to investigate the semiannual geomagnetic variation and its relation to CMEs. We find that the geomagnetic effectiveness of CMEs and post-shock solar wind is well-ordered by speed and by the southward component of the IMF in GSM coordinates, as well as by preexisting geomagnetic conditions. The post-shock seasonal effect, with geomagnetic effectiveness maximizing near April 5 for negative GSEQ By and near October 5 for positive GSEQ By, is identifiable in shock and shock/CME events, but not for CME events without leading shocks. When used to complement the more fundamental causal parameter of CME speed, the seasonal effect appears to have value for prediction of geomagnetic storms.

  4. On interplanetary coronal mass ejection identification at 1 AU

    Energy Technology Data Exchange (ETDEWEB)

    Mulligan, T.; Russell, C.T. [Institute of Geophysics and Planetary Physics and the Department of Earth and Space Sciences University of California Los Angeles (United States); Gosling, J.T. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States)

    1999-06-01

    Coronal mass ejections are believed to be produced in the corona from closed magnetic regions not previously participating in the solar wind expansion. At 1 AU their interplanetary counterparts (ICMEs) generally have a number of distinct plasma and field signatures that distinguish them from the ambient solar wind. These include heat flux dropouts, bi-directional streaming, enhanced alpha particle events, times of depressed proton temperatures, intervals of distorted or enhanced magnetic field, and times of large magnetic field rotations characteristic of magnetic clouds. The first three of these signatures are phenomena that occur at some point within the ICME, but do not necessarily persist throughout the entire ICME. The large scale magnetic field rotations, distortions and enhancements, and the proton temperature depressions tend to mark more accurately the beginning and end of the ICME proper. We examine herein the reliability with which each of these markers identifies ICMEs utilizing ISEE-3 data from 1978{endash}1980. {copyright} {ital 1999 American Institute of Physics.}

  5. Large Geomagnetic Storms Associated with Limb Halo Coronal Mass Ejections

    CERN Document Server

    Gopalswamy, Nat; Xie, Hong; Akiyama, Sachiko; Makela, Pertti

    2009-01-01

    Solar cycle 23 witnessed the observation of hundreds of halo coronal mass ejections (CMEs), thanks to the high dynamic range and extended field of view of the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO) mission. More than two thirds of halo CMEs originating on the front side of the Sun have been found to be geoeffective (Dst = 45deg) have a 20% shorter delay time on the average. It was suggested that the geomagnetic storms due to limb halos must be due to the sheath portion of the interplanetary CMEs (ICMEs) so that the shorter delay time can be accounted for. We confirm this suggestion by examining the sheath and ejecta portions of ICMEs from Wind and ACE data that correspond to the limb halos. Detailed examination showed that three pairs of limb halos were interacting events. Geomagnetic storms following five limb halos were actually produced by other disk halos. The storms followed by four isolated limb halos and the ones associated with interact...

  6. The Relationship of Coronal Mass Ejections to Streamers

    CERN Document Server

    Subramanian, P; Rich, N B; Howard, R A; Subramanian, Prasad

    1999-01-01

    We have examined images from the Large Angle Spectroscopic Coronagraph (LASCO) to study the relationship of Coronal Mass Ejections (CMEs) to coronal streamers. We wish to test the suggestion (Low 1996) that CMEs arise from flux ropes embedded in a streamer erupting, thus disrupting the streamer. The data span a period of two years near sunspot minimum through a period of increased activity as sunspot numbers increased. We have used LASCO data from the C2 coronagraph which records Thomson scattered white light from coronal electrons at heights between 1.5 and 6R_sun. Maps of the coronal streamers have been constructed from LASCO C2 observations at a height of 2.5R_sun at the east and west limbs. We have superposed the corresponding positions of CMEs observed with the C2 coronagraph onto the synoptic maps. We identified the different kinds of signatures CMEs leave on the streamer structure at this height (2.5R_sun). We find four types of CMEs with respect to their effect on streamers: 1. CMEs that disrupt the s...

  7. The 3D structure of Coronal Mass Ejections

    Science.gov (United States)

    Patsourakos, Spiros

    2016-07-01

    Coronal Mass Ejections (CMEs) represent one of the most powerful energy release phenomena in the entire solar system and are a major driver of space weather. Prior to 2006, our observational access to CMEs was limited to single viewpoint remote sensing observations in the inner/outer corona, and in-situ observations further away, e.g. at 1 AU. Taking all these factors together, turned out to be a major obstacle in our understanding and characterizing of the 3D structure and evolution of CMEs. The situation improved dramatically with the availability of multi-viewpoint imaging observations of CMEs, all way through from the Sun to 1 AU, from the STEREO mission since 2006, combined with observations from other missions (SOHO, Hinode, SDO, IRIS). With this talk we will discuss several key recent results in CME science resulting from the analysis of multi-viewpoint observations. This includes: (1) shape and structure; (2) kinematics and energetics; (3) trajectories, deflections and rotations; (4) arrival times and velocities at 1 AU; (5) magnetic field structure; (6) relationships with coronal and interplanetary shocks and solar energetic particles. The implications of these results in terms of CME theories and models will be also addressed. We will conclude with a discussion of important open issues in our understanding of CMEs and how these could be addressed with upcoming (Solar Orbiter, Solar Probe Plus) and under-study missions (e.g., L5).

  8. A numerical study of two interacting coronal mass ejections

    Directory of Open Access Journals (Sweden)

    J. M. Schmidt

    2004-06-01

    Full Text Available The interaction in the solar wind between two coronal mass ejections (CMEs is investigated using numerical simulations. We show that the nature of the interaction depends on whether the CME magnetic structures interact, but in all cases the result is an equilisation of the speed of the two CMEs. In the absence of magnetic interaction, the forward shock of the faster trailing CME interacts with the slow leading CME, and accelerates it. When the two CMEs have magnetic fields with the same sense of rotation, magnetic reconnection occurs between the two CMEs, leading to the formation of a single magnetic structure: in the most extreme cases, one CME "eats" the other. When the senses of rotation are opposite, reconnection does not occur, but the CMEs collide in a highly non-elastic manner, again forming a single structure. The possibility of enhanced particle acceleration in such processes is assessed. The presence of strong magnetic reconnection provides excellent opportunities for the acceleration of thermal particles, which then form a seed population for further acceleration at the CME shocks. The presence of a large population of seed particles will thus lead to an overall increase in energetic particle fluxes, as suggested by some observations.

  9. Regarding the detectability and measurement of coronal mass ejections

    Directory of Open Access Journals (Sweden)

    Howard Timothy A.

    2015-01-01

    Full Text Available In this review I discuss the problems associated with the detection and measurement of coronal mass ejections (CMEs. CMEs are important phenomena both scientifically, as they play a crucial role in the evolution of the solar corona, and technologically, as their impact with the Earth leads to severe space weather activity in the form of magnetic storms. I focus on the observation of CMEs using visible white light imagers (coronagraphs and heliospheric imagers, as they may be regarded as the binding agents between different datasets and different models that are used to reconstruct them. Our ability to accurately measure CMEs observed by these imagers is hampered by many factors, from instrumental to geometrical to physical. Following a brief review of the history of CME observation and measurement, I explore the impediments to our ability to measure them and describe possible means for which we may be able to mitigate those impediments. I conclude with a discussion of the claim that we have reached the limit of the information that we can extract from the current generation of white light imagers, and discuss possible ways forward regarding future instrument capabilities.

  10. Dust Ejection from Planetary Bodies by Temperature Gradients: Laboratory Experiments

    CERN Document Server

    Kelling, Thorben; Kocifaj, Miroslav; Klacka, Jozef; Reiss, Dennis

    2011-01-01

    Laboratory experiments show that dusty bodies in a gaseous environment eject dust particles if they are illuminated. We find that even more intense dust eruptions occur when the light source is turned off. We attribute this to a compression of gas by thermal creep in response to the changing temperature gradients in the top dust layers. The effect is studied at a light flux of 13 kW/(m*m) and 1 mbar ambient pressure. The effect is applicable to protoplanetary disks and Mars. In the inner part of protoplanetary disks, planetesimals can be eroded especially at the terminator of a rotating body. This leads to the production of dust which can then be transported towards the disk edges or the outer disk regions. The generated dust might constitute a significant fraction of the warm dust observed in extrasolar protoplanetary disks. We estimate erosion rates of about 1 kg/s for 100 m parent bodies. The dust might also contribute to subsequent planetary growth in different locations or on existing protoplanets which ...

  11. Data Constrained Coronal Mass Ejections in A Global Magnetohydrodynamics Model

    CERN Document Server

    Jin, M; van der Holst, B; Sokolov, I; Toth, G; Mullinix, R E; Taktakishvili, A; Chulaki, A; Gombosi, T I

    2016-01-01

    We present a first-principles-based coronal mass ejection (CME) model suitable for both scientific and operational purposes by combining a global magnetohydrodynamics (MHD) solar wind model with a flux rope-driven CME model. Realistic CME events are simulated self-consistently with high fidelity and forecasting capability by constraining initial flux rope parameters with observational data from GONG, SOHO/LASCO, and STEREO/COR. We automate this process so that minimum manual intervention is required in specifying the CME initial state. With the newly developed data-driven Eruptive Event Generator Gibson-Low (EEGGL), we present a method to derive Gibson-Low (GL) flux rope parameters through a handful of observational quantities so that the modeled CMEs can propagate with the desired CME speeds near the Sun. A test result with CMEs launched with different Carrington rotation magnetograms are shown. Our study shows a promising result for using the first-principles-based MHD global model as a forecasting tool, wh...

  12. Automatic Determination of the Conic Coronal Mass Ejection Model Parameters

    Science.gov (United States)

    Pulkkinen, A.; Oates, T.; Taktakishvili, A.

    2009-01-01

    Characterization of the three-dimensional structure of solar transients using incomplete plane of sky data is a difficult problem whose solutions have potential for societal benefit in terms of space weather applications. In this paper transients are characterized in three dimensions by means of conic coronal mass ejection (CME) approximation. A novel method for the automatic determination of cone model parameters from observed halo CMEs is introduced. The method uses both standard image processing techniques to extract the CME mass from white-light coronagraph images and a novel inversion routine providing the final cone parameters. A bootstrap technique is used to provide model parameter distributions. When combined with heliospheric modeling, the cone model parameter distributions will provide direct means for ensemble predictions of transient propagation in the heliosphere. An initial validation of the automatic method is carried by comparison to manually determined cone model parameters. It is shown using 14 halo CME events that there is reasonable agreement, especially between the heliocentric locations of the cones derived with the two methods. It is argued that both the heliocentric locations and the opening half-angles of the automatically determined cones may be more realistic than those obtained from the manual analysis

  13. A spectacular coronal mass ejection event and associated phenomena

    Science.gov (United States)

    Ma, Yuan; Li, Chun-Sheng; Song, Qian

    Based on the data taken from S. G. D. and relevant simultaneous observations of solar radio bursts, gamma-ray emission and geophysical effects on June 15, 1991 the relationships among these phenomena are discussed in this paper. Through the analyses it is considered that proton events and GLE events occurred on June 15 in 1991, which were the geophysic responses caused by CME (V>=750 km/s). Simultaneous observation of the bursts at the centimetric and decimetric wavelengths can obtain the U-shape spectrum of speak fluxes, which is still one of the effective tools for predicting proton events and its production mechanism can be explained by using the acceleration of the direct current field parallel to the magnetic field in the electric current sheet formed in the process of the production of spray prominences. However, the process in which electrons are accelerated up to the high energy state remains to be explained. The whole event of June 15 1991, from the coronal matter ejection (or the spray prominences in active regions) to the production of various geophysic effects, has explained and verified.

  14. Spironolactone in patients with heart failure and preserved ejection fraction.

    Science.gov (United States)

    Sánchez-Sánchez, C; Mendoza-Ruiz de Zuazu, H F; Formiga, F; Manzano, L; Ceresuela, L M; Carrera-Izquierdo, M; González Franco, Á; Epelde-Gonzalo, F; Cerqueiro-González, J M; Montero-Pérez-Barquero, M

    2015-01-01

    Aldosterone inhibitors have been shown to be beneficial for patients with systolic heart failure. However, the evidence from patients with heart failure and preserved ejection fraction (HFPEF) is limited. We evaluated the role of spironolactone in the prognosis of a cohort of patients with HFPEF. We analyzed the outcomes of patients hospitalized for HFPEF in 52 departments of internal medicine of the Spanish RICA registry according to those who did and did not take spironolactone. We recorded the posthospital mortality rate and readmissions at 1 year and performed a multivariate survival analysis. We included 1212 patients with HFPEF, with a mean age of 79 years (standard deviation, 7.9), (64.1% women), the majority of whom had hypertensive heart disease (50.7%). The patients treated with spironolactone, compared with those who were not treated with this diuretic, had a more advanced functional class, a higher number of readmissions (44.3 vs. 29.1%; p<0.001) and a higher rate in the combined variable of readmissions/mortality (39.0 vs. 29.0%; p=0.001). In the multivariate analysis, the administration of spironolactone was associated with an increase in readmissions (RR, 1.4; 95% CI, 1.16-1.78; p=0.001). For patients with HFPEF, the administration of spironolactone was associated with an increase in all-cause readmission, perhaps due to the higher rate of hyperpotassemia. Copyright © 2015. Published by Elsevier España, S.L.U.

  15. [Heart failure with preserved left ventricular ejection fraction].

    Science.gov (United States)

    Maeder, Micha T; Rickli, Hans

    2013-10-16

    Heart failure with preserved left ventricular ejection fraction (LVEF; HFpEF) is a common type of heart failure in the elderly, and it typically represents advanced hypertensive heart disease. The left ventricle in patients with HFpEF is characterized by concentric remodeling, normal LVEF, but reduced left longitudinal shortening, and importantly diastolic dysfunction. Dyspnoe and fatigue in patients with HFpEF are due to impaired left ventricular filling with a rapid increase in filling pressures and the lack of an increase in stroke volume during exercise. The diagnosis of HFpEF requires the careful exclusion of non-cardiac causes of dyspnoe as well as cardiac causes of dyspnoe associated with preserved LVEF other than HFpEF, primarily coronary artery disease and valve disease. Then, the following findings are required to make a diagnosis of HFpEF: a non-dilated left ventricle with an LVEF >50% and the presence of a significant diastolic impairment, which can be assessed using invasive haemodynamics, echocardiography, natriuretic peptides, or a combination of these tools. In contrast to patients with heart failure and reduced LVEF there is still no established treatment for patients with HFpEF, which prolongs survival or reduces the rate of hospitalizations for heart failure. There is currently however intense research going on in this field, and results from large trials evaluating the effects of various interventions on clinical endpoints are expected within the next years.

  16. Survivability of bacteria ejected from icy surfaces after hypervelocity impact.

    Science.gov (United States)

    Burchell, Mark J; Galloway, James A; Bunch, Alan W; Brandão, Pedro F B

    2003-02-01

    Both the Saturnian and Jovian systems contain satellites with icy surfaces. If life exists on any of these icy bodies (in putative subsurface oceans for example) then the possibility exists for transfer of life from icy body to icy body. This is an application of the idea of Panspermia, wherein life migrates naturally through space. A possible mechanism would be that life, here taken as bacteria, could become frozen in the icy surface of one body. If a high-speed impact occurred on that surface, ejecta containing the bacteria could be thrown into space. It could then migrate around the local region of space until it arrived at a second icy body in another high-speed impact. In this paper we consider some of the necessary steps for such a process to occur, concentrating on the ejection of ice bearing bacteria in the initial impact, and on what happens when bacteria laden projectiles hit an icy surface. Laboratory experiments using high-speed impacts with a light gas gun show that obtaining icy ejecta with viable bacterial loads is straightforward. In addition to demonstrating the viability of the bacteria carried on the ejecta, we have also measured the angular and size distribution of the ejecta produced in hypervelocity impacts on ice. We have however been unsuccessful at transferring viable bacteria to icy surfaces from bacteria laden projectiles impacting at hypervelocities.

  17. Global Energetics in Solar Flares and Coronal Mass Ejections

    Science.gov (United States)

    Aschwanden, Markus J.

    2017-08-01

    We present a statistical study of the energetics of coronal mass ejections (CME) and compare it with the magnetic, thermal, and nonthermal energy dissipated in flares. The physical parameters of CME speeds, mass, and kinetic energies are determined with two different independent methods, i.e., the traditional white-light scattering method using LASCO/SOHO data, and the EUV dimming method using AIA/SDO data. We analyze all 860 GOES M- and X-class flare events observed during the first 7 years (2010-2016) of the SDO mission. The new ingredients of our CME modeling includes: (1) CME geometry in terms of a self-similar adiabatic expansion, (2) DEM analysis of CME mass over entire coronal temperature range, (3) deceleration of CME due to gravity force which controls the kinetic and potentail CME energy as a function of time, (4) the critical speed that controls eruptive and confined CMEs, (5) the relationship between the center-of-mass motion during EUV dimming and the leading edge motion observed in white-light coronagraphs. Novel results are: (1) Physical parameters obtained from both the EUV dimming and white-light method can be reconciled; (2) the equi-partition of CME kinetic and thermal flare energy; (3) the Rosner-Tucker-Vaiana scaling law. We find that the two methods in EUV and white-light wavelengths are highly complementary and yield more complete models than each method alone.

  18. The coronal mass ejection waiting-time distribution

    CERN Document Server

    Wheatland, M S

    2003-01-01

    The distribution of times $\\Delta t$ between coronal mass ejections (CMEs) in the Large Angle and Spectrometric Coronagraph (LASCO) CME catalog for the years 1996-2001 is examined. The distribution exhibits a power-law tail $\\propto (\\Delta t)^{\\gamma}$ with an index $\\gamma\\approx -2.36\\pm 0.11$ for large waiting times ($\\Delta t>10 {\\rm hours}$). The power-law index of the waiting-time distribution varies with the solar cycle: for the years 1996-1998 (a period of low activity), the power-law index is $\\gamma\\approx-1.86\\pm 0.14$, and for the years 1999-2001 (a period of higher activity), the index is $\\gamma\\approx-2.98\\pm 0.20$. The observed CME waiting-time distribution, and its variation with the cycle, may be understood in terms of CMEs occurring as a time-dependent Poisson process. The CME waiting-time distribution is compared with that for greater than C1 class solar flares in the Geostationary Operational Environmental Satellite (GOES) catalog for the same years. The flare and CME waiting-time distri...

  19. Ensemble Modeling of the 23 July 2012 Coronal Mass Ejection

    Science.gov (United States)

    Cash, M. D.; Biesecker, D. A.; Pizzo, V.; Koning, C. A.; Millward, G.; Arge, C. N.; Henney, C. J.; Odstrcil, D.

    2015-10-01

    On 23 July 2012 a significant and rapid coronal mass ejection (CME) was detected in situ by the Solar Terrestrial Relations Observatory (STEREO) A. This CME was unusual due to its extremely brief Sun-to-1 AU transit time of less than 21 h and its exceptionally high impact speed of 2246 km/s. If this CME had been Earth directed, it would have produced a significant geomagnetic storm with potentially serious consequences. To protect our ground- and space-based assets, there is a clear need to accurately forecast the arrival times of such events using realistic input parameters and models run in near real time. Using Wang-Sheely-Arge (WSA)-Enlil, the operational model currently employed at the NOAA Space Weather Prediction Center, we investigate the sensitivity of the 23 July CME event to model input parameters. Variations in the initial CME speed, angular width, and direction, as well as the ambient solar wind background, are investigated using an ensemble approach to study the effect on the predicted arrival time of the CME at STEREO A. Factors involved in the fast transit time of this large CME are discussed, and potential improvements to modeling such events with the WSA-Enlil model are presented.

  20. A Type II Radio Burst without a Coronal Mass Ejection

    CERN Document Server

    Su, W; Ding, M D; Chen, P F; Sun, J Q

    2015-01-01

    Type II radio bursts are thought to be a signature of coronal shocks. In this paper, we analyze a short-lived type II burst that started at 07:40 UT on 2011 February 28. By carefully checking white-light images, we find that the type II radio burst is not accompanied by a coronal mass ejection, only with a C2.4 class flare and narrow jet. However, in the extreme-ultraviolet (EUV) images provided by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO), we find a wave-like structure that propagated at a speed of $\\sim$ 600 km s$^{-1}$ during the burst. The relationship between the type II radio burst and the wave-like structure is in particular explored. For this purpose, we first derive the density distribution under the wave by the differential emission measure (DEM) method, which is used to restrict the empirical density model. We then use the restricted density model to invert the speed of the shock that produces the observed frequency drift rate in the dynamic spectrum. The ...

  1. INTERCOMPARISON OF RESULTS FOR A PWR ROD EJECTION ACCIDENT

    Energy Technology Data Exchange (ETDEWEB)

    DIAMOND,D.J.; ARONSON,A.; JO,J.; AVVAKUMOV,A.; MALOFEEV,V.; SIDOROV,V.; FERRARESI,P.; GOUIN,C.; ANIEL,S.; ROYER,M.E.

    1999-10-01

    This study is part of an overall program to understand the uncertainty in best-estimate calculations of the local fuel enthalpy during the rod ejection accident. Local fuel enthalpy is used as the acceptance criterion for this design-basis event and can also be used to estimate fuel damage for the purpose of determining radiological consequences. The study used results from neutron kinetics models in PARCS, BARS, and CRONOS2, codes developed in the US, the Russian Federation, and France, respectively. Since BARS uses a heterogeneous representation of the fuel assembly as opposed to the homogeneous representations in PARCS and CRONOS, the effect of the intercomparison was primarily to compare different intra-assembly models. Quantitative comparisons for core power, reactivity, assembly fuel enthalpy and pin power were carried out. In general the agreement between methods was very good providing additional confidence in the codes and providing a starting point for a quantitative assessment of the uncertainty in calculated fuel enthalpy using best-estimate methods.

  2. A Study of Fast Flareless Coronal Mass Ejections

    CERN Document Server

    Song, H Q; Ye, D D; Han, G Q; Du, G H; Li, G; Zhang, J; Hu, Q

    2013-01-01

    Two major processes have been proposed to convert the coronal magnetic energy into the kinetic energy of a coronal mass ejection (CME): resistive magnetic reconnection and ideal macroscopic magnetohydrodynamic instability of magnetic flux rope. However, it remains elusive whether both processes play a comparable role or one of them prevails during a particular eruption. To shed light on this issue, we carefully studied energetic but flareless CMEs, \\textit{i.e.}, fast CMEs not accompanied by any flares. Through searching the Coordinated Data Analysis Workshops (CDAW) database of CMEs observed in Solar Cycle 23, we found 13 such events with speeds larger than 1000 km s$^{-1}$. Other common observational features of these events are: (1) none of them originated in active regions; they were associated with eruptions of well-developed long filaments in quiet-Sun regions, (2) no apparent enhancement of flare emissions was present in soft X-ray, EUV and microwave data. Further studies of two events reveal that (1) ...

  3. VLA Measurements of Faraday Rotation through Coronal Mass Ejections

    CERN Document Server

    Kooi, Jason E; Buffo, Jacob J; Spangler, Steven R

    2016-01-01

    Coronal mass ejections (CMEs) are large-scale eruptions of plasma from the Sun that play an important role in space weather. Faraday rotation (FR) is the rotation of the plane of polarization that results when a linearly polarized signal passes through a magnetized plasma such as a CME. FR observations of a source near the Sun can provide information on the plasma structure of a CME shortly after launch. We report on simultaneous white-light and radio observations made of three CMEs in August 2012. We made sensitive Very Large Array (VLA) full-polarization observations using 1 - 2 GHz frequencies of a "constellation" of radio sources through the solar corona at heliocentric distances that ranged from 6 - 15 solar radii. Of the nine sources observed, three were occulted by CMEs: two sources (0842+1835 and 0900+1832) were occulted by a single CME and one source (0843+1547) was occulted by two CMEs. In addition to our radioastronomical observations, which represent one of the first active hunts for CME Faraday r...

  4. Successive Resonances for Ion Ejection at Arbitrary Frequencies in an Ion Trap

    Science.gov (United States)

    Snyder, Dalton T.; Cooks, R. Graham

    2016-09-01

    The use of successive resonances for ion ejection is demonstrated here as a method of scanning quadrupole ion traps with improvement in both resolution and sensitivity compared with single frequency resonance ejection. The conventional single frequency resonance ejection waveform is replaced with a dual-frequency waveform. The two included frequencies are spaced very closely and their relative amplitudes are adjusted so that the first frequency that ions encounter excites them to higher amplitudes where space charge effects are less prominent, thereby giving faster and more efficient ejection when the ions come into resonance with the second frequency. The method is applicable at any arbitrary frequency, unlike double and triple resonance methods. However, like double and triple resonance ejection, ejection using successive resonances requires the rf and AC waveforms to be phase-locked in order to retain mass accuracy and mass precision. The improved performance is seen in mass spectra acquired by rf amplitude scans (resonance ejection) as well as by secular frequency scans.

  5. Multiple Plasmoid Ejections and Associated Hard X-ray Bursts in the 2000 November 24 Flare

    CERN Document Server

    Nishizuka, N; Asai, A; Shibata, K; 10.1088/0004-637X/711/2/1062

    2013-01-01

    The Soft X-ray Telescope (SXT) on board Yohkoh revealed that the ejection of X-ray emitting plasmoid is sometimes observed in a solar flare. It was found that the ejected plasmoid is strongly accelerated during a peak in the hard X-ray emission of the flare. In this paper we present an examination of the GOES X 2.3 class flare that occurred at 14.51 UT on 2000 November 24. In the SXT images we found multiple plasmoid ejections with velocities in the range of 250-1500 km/s, which showed blob-like or loop-like structures. Furthermore, we also found that each plasmoid ejection is associated with an impulsive burst of hard X-ray emission. Although some correlation between plasmoid ejection and hard X-ray emission has been discussed previously, our observation shows similar behavior for multiple plasmoid ejection such that each plasmoid ejection occurs during the strong energy release of the solar flare. As a result of temperature-emission measure analysis of such plasmoids, it was revealed that the apparent veloc...

  6. Evidence for direct geographic influences on linguistic sounds: the case of ejectives.

    Directory of Open Access Journals (Sweden)

    Caleb Everett

    Full Text Available We present evidence that the geographic context in which a language is spoken may directly impact its phonological form. We examined the geographic coordinates and elevations of 567 language locations represented in a worldwide phonetic database. Languages with phonemic ejective consonants were found to occur closer to inhabitable regions of high elevation, when contrasted to languages without this class of sounds. In addition, the mean and median elevations of the locations of languages with ejectives were found to be comparatively high. The patterns uncovered surface on all major world landmasses, and are not the result of the influence of particular language families. They reflect a significant and positive worldwide correlation between elevation and the likelihood that a language employs ejective phonemes. In addition to documenting this correlation in detail, we offer two plausible motivations for its existence. We suggest that ejective sounds might be facilitated at higher elevations due to the associated decrease in ambient air pressure, which reduces the physiological effort required for the compression of air in the pharyngeal cavity--a unique articulatory component of ejective sounds. In addition, we hypothesize that ejective sounds may help to mitigate rates of water vapor loss through exhaled air. These explications demonstrate how a reduction of ambient air density could promote the usage of ejective phonemes in a given language. Our results reveal the direct influence of a geographic factor on the basic sound inventories of human languages.

  7. Dynamical ejections of massive stars from young star clusters under diverse initial conditions

    Science.gov (United States)

    Oh, Seungkyung; Kroupa, Pavel

    2016-05-01

    We study the effects that initial conditions of star clusters and their massive star population have on dynamical ejections of massive stars from star clusters up to an age of 3 Myr. We use a large set of direct N-body calculations for moderately massive star clusters (Mecl ≈ 103.5 M⊙). We vary the initial conditions of the calculations, such as the initial half-mass radius of the clusters, initial binary populations for massive stars and initial mass segregation. We find that the initial density is the most influential parameter for the ejection fraction of the massive systems. The clusters with an initial half-mass radius rh(0) of 0.1 (0.3) pc can eject up to 50% (30)% of their O-star systems on average, while initially larger (rh(0) = 0.8 pc) clusters, that is, lower density clusters, eject hardly any OB stars (at most ≈ 4.5%). When the binaries are composed of two stars of similar mass, the ejections are most effective. Most of the models show that the average ejection fraction decreases with decreasing stellar mass. For clusters that are efficient at ejecting O stars, the mass function of the ejected stars is top-heavy compared to the given initial mass function (IMF), while the mass function of stars that remain in the cluster becomes slightly steeper (top-light) than the IMF. The top-light mass functions of stars in 3 Myr old clusters in our N-body models agree well with the mean mass function of young intermediate-mass clusters in M 31, as reported previously. This implies that the IMF of the observed young clusters is the canonical IMF. We show that the multiplicity fraction of the ejected massive stars can be as high as ≈ 60%, that massive high-order multiple systems can be dynamically ejected, and that high-order multiples become common especially in the cluster. We also discuss binary populations of the ejected massive systems. Clusters that are initially not mass-segregated begin ejecting massive stars after a time delay that is caused by mass

  8. Cavitation dynamics and directional microbubble ejection induced by intense femtosecond laser pulses in liquids.

    Science.gov (United States)

    Faccio, D; Tamošauskas, G; Rubino, E; Darginavičius, J; Papazoglou, D G; Tzortzakis, S; Couairon, A; Dubietis, A

    2012-09-01

    We study cavitation dynamics when focusing ring-shaped femtosecond laser beams in water. This focusing geometry reduces detrimental nonlinear beam distortions and enhances energy deposition within the medium, localized at the focal spot. We observe remarkable postcollapse dynamics of elongated cavitation bubbles with high-speed ejection of microbubbles out of the laser focal region. Bubbles are ejected along the laser axis in both directions (away and towards the laser). The initial shape of the cavitation bubble is also seen to either enhance or completely suppress jet formation during collapse. In the absence of jetting, microbubble ejection occurs orthogonal to the laser propagation axis.

  9. Burden of Recurrent Hospitalizations Following an Admission for Acute Heart Failure: Preserved Versus Reduced Ejection Fraction.

    Science.gov (United States)

    Santas, Enrique; Valero, Ernesto; Mollar, Anna; García-Blas, Sergio; Palau, Patricia; Miñana, Gema; Núñez, Eduardo; Sanchis, Juan; Chorro, Francisco Javier; Núñez, Julio

    2017-04-01

    Heart failure with preserved ejection fraction and reduced ejection fraction share a high mortality risk. However, differences in the rehospitalization burden over time between these 2 entities remains unclear. We prospectively included 2013 consecutive patients discharged for acute heart failure. Of these, 1082 (53.7%) had heart failure with preserved ejection fraction and 931 (46.2%) had heart failure with reduced ejection fraction. Cox and negative binomial regression methods were used to evaluate the risks of death and repeat hospitalizations, respectively. At a median follow-up of 2.36 years (interquartile range: 0.96-4.65), 1018 patients (50.6%) died, and 3804 readmissions were registered in 1406 patients (69.8%). Overall, there were no differences in mortality between heart failure with preserved ejection fraction and heart failure with reduced ejection fraction (16.7 vs 16.1 per 100 person-years, respectively; P=0794), or all-cause repeat hospitalization rates (62.1 vs 62.2 per 100 person-years, respectively; P=.944). After multivariable adjustment, and compared with patients with heart failure with reduced ejection fraction, patients with heart failure with preserved ejection fraction exhibited a similar risk of all-cause readmissions (incidence rate ratio=1.04; 95%CI, 0.93-1.17; P=.461). Regarding specific causes, heart failure with preserved ejection fraction showed similar risks of cardiovascular and heart failure-related rehospitalizations (incidence rate ratio=0.93; 95%CI, 0.82-1.06; P=.304; incidence rate ratio=0.96; 95% confidence interval, 0.83-1.13; P=.677, respectively), but had a higher risk of noncardiovascular readmissions (incidence rate ratio=1.24; 95%CI, 1.04-1.47; P=.012). Following an admission for acute heart failure, patients with heart failure with preserved ejection fraction have a similar rehospitalization burden to those with heart failure with reduced ejection fraction. However, patients with heart failure with preserved ejection

  10. New Classification for Heart Failure with Mildly Reduced Ejection Fraction; Greater clarity or more confusion?

    Directory of Open Access Journals (Sweden)

    Sunil Nadar

    2017-03-01

    Full Text Available The latest European Society of Cardiology (ESC guidelines for the diagnosis and management of heart failure include a new patient group for those with heart failure with mildly reduced ejection fraction (HFmrEF. By defining this group of patients as a separate entity, the ESC hope to encourage more research focusing on patients with HFmrEF. Previously, patients with this condition were caught between two classifications—heart failure with reduced ejection fraction and heart failure with preserved ejection fraction. Hopefully, the inclusion of new terminology will not increase confusion, but rather aid our understanding of heart failure, a complex clinical syndrome.

  11. Magnetic reconnection in the interior of interplanetary coronal mass ejections.

    Science.gov (United States)

    Fermo, R L; Opher, M; Drake, J F

    2014-07-18

    Recent in situ observations of interplanetary coronal mass ejections (ICMEs) found signatures of reconnection exhausts in their interior or trailing edge. Whereas reconnection on the leading edge of an ICME would indicate an interaction with the coronal or interplanetary environment, this result suggests that the internal magnetic field reconnects with itself. In light of this data, we consider the stability properties of flux ropes first developed in the context of astrophysics, then further elaborated upon in the context of reversed field pinches (RFPs). It was shown that the lowest energy state of a flux rope corresponds to ∇ × B = λB with λ a constant, the so-called Taylor state. Variations from this state will result in the magnetic field trying to reorient itself into the Taylor state solution, subject to the constraints that the toroidal flux and magnetic helicity are invariant. In reversed field pinches, this relaxation is mediated by the reconnection of the magnetic field, resulting in a sawtooth crash. If we likewise treat the ICME as a flux rope, any deviation from the Taylor state will result in reconnection within the interior of the flux tube, in agreement with the observations by Gosling et al. Such a departure from the Taylor state takes place as the flux tube cross section expands in the latitudinal direction, as seen in magnetohydrodynamic (MHD) simulations of flux tubes propagating through the interplanetary medium. We show analytically that this elongation results in a state which is no longer in the minimum energy Taylor state. We then present magnetohydrodynamic simulations of an elongated flux tube which has evolved away from the Taylor state and show that reconnection at many surfaces produces a complex stochastic magnetic field as the system evolves back to a minimum energy state configuration.

  12. A SOLAR CORONAL JET EVENT TRIGGERS A CORONAL MASS EJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiajia; Wang, Yuming; Shen, Chenglong; Liu, Kai; Pan, Zonghao; Wang, S. [CAS Key Laboratory of Geospace Environment, Earh and Space Science School, University of Science and Technology of China, No. 96, JinZhai Road, Hefei, Anhui 230026 (China)

    2015-11-10

    In this paper, we present multi-point, multi-wavelength observations and analysis of a solar coronal jet and coronal mass ejection (CME) event. Employing the GCS model, we obtained the real (three-dimensional) heliocentric distance and direction of the CME and found it to propagate at a high speed of over 1000 km s{sup −1}. The jet erupted before the CME and shared the same source region. The temporal and spacial relationship between these two events lead us to the possibility that the jet triggered the CME and became its core. This scenario hold the promise of enriching our understanding of the triggering mechanism of CMEs and their relations to coronal large-scale jets. On the other hand, the magnetic field configuration of the source region observed by the Solar Dynamics Observatory (SDO)/HMI instrument along with the off-limb inverse Y-shaped configuration observed by SDO/AIA in the 171 Å passband provide the first detailed observation of the three-dimensional reconnection process of a large-scale jet as simulated in Pariat et al. The eruption process of the jet highlights the importance of filament-like material during the eruption of not only small-scale X-ray jets, but likely also of large-scale EUV jets. Based on our observations and analysis, we propose the most probable mechanism for the whole event, with a blob structure overlaying the three-dimensional structure of the jet, to describe the interaction between the jet and the CME.

  13. Ejection of Supernova-Enriched Gas From Dwarf Disk Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Fragile, P C; Murray, S D; Lin, D C

    2004-06-15

    We examine the efficiency with which supernova-enriched gas may be ejected from dwarf disk galaxies, using a methodology previously employed to study the self-enrichment efficiency of dwarf spheroidal systems. Unlike previous studies that focused on highly concentrated starbursts, in the current work we consider discrete supernova events spread throughout various fractions of the disk. We model disk systems having gas masses of 10{sup 8} and 10{sup 9} M{sub {circle_dot}} with supernova rates of 30, 300, and 3000 Myr{sup -1}. The supernova events are confined to the midplane of the disk, but distributed over radii of 0, 30, and 80% of the disk radius, consistent with expectations for Type II supernovae. In agreement with earlier studies, we find that the enriched material from supernovae is largely lost when the supernovae are concentrated near the nucleus, as expected for a starburst event. In contrast, we find the loss of enriched material to be much less efficient (as low as 21%) when the supernovae occur over even a relatively small fraction of the disk. The difference is due to the ability of the system to relax following supernova events that occur over more extended regions. Larger physical separations also reduce the likelihood of supernovae going off within low-density ''chimneys'' swept out by previous supernovae. We also find that, for the most distributed systems, significant metal loss is more likely to be accompanied by significant mass loss. A comparison with theoretical predications indicates that, when undergoing self-regulated star formation, galaxies in the mass range considered shall efficiently retain the products of Type II supernovae.

  14. Heart failure with preserved ejection fraction: uncertainties and dilemmas.

    Science.gov (United States)

    Ferrari, Roberto; Böhm, Michael; Cleland, John G F; Paulus, Walter J S; Pieske, Burkert; Rapezzi, Claudio; Tavazzi, Luigi

    2015-07-01

    Many uncertainties surround the syndrome of heart failure with preserved ejection fraction (HFpEF), which was the topic reviewed in an Expert Meeting at the University of Ferrara. This concluded that the absence of clear diagnostic clinical criteria was the major barrier to progress. There was general agreement that symptoms or signs of heart failure, normal LVEF despite an elevated plasma concentration of natriuretic peptides, and signs of abnormal LV relaxation, LV filling, LV hypertrophy, or left atrial enlargement, or diastolic dysfunction supported the diagnosis. However, HFpEF, like all heart failure syndromes, is heterogeneous in aetiology and pathophysiology, rather than being a single disease. HFpEF may account for about half of all patients with heart failure. The classical risk factors for developing HFpEF include age and co-morbidities, notably hypertension, atrial fibrillation, and the metabolic syndrome. When complicated by increasing congestion requiring hospital admission, the prognosis is poor; 30% or more of patients will die within 1 year (nearly two-thirds die from cardiovascular causes). Patients with chronic stable symptoms have a much better prognosis. Despite many clinical trials, there is no solid evidence that any treatment alters the natural history of HFpEF. Several treatments have shown promising early results and are now being tested in substantial randomized clinical trials. Further basic research is required to better characterize the disease and accelerate progress. Our review highlights the many difficulties encountered in performing randomized clinical trials in HFpEF, often due to difficulties in characterizing HFpEF itself.

  15. Reproducibility of gallbladder ejection fraction measured by fatty meal cholescintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Muqbel, Kusai M.; Hani, M. N. Hani; Elheis, M. A.; Al-Omari, M. H. [School of Medicine, Jordan University of Science and Technology, Irbid (Jordan)

    2010-12-15

    There are conflicting data in the literature regarding the reproducibility of the gallbladder ejection fraction (GBEF) measured by fatty meal cholescintigraphy (CS). We aimed to test the reproducibility of GBEF measured by fatty meal CS. Thirty-five subjects (25 healthy volunteers and 10 patients with chronic abdominal pain) underwent fatty meal CS twice in order to measure GBEF1 and GBEF2. The healthy volunteers underwent a repeat scan within 1-13 months from the first scan. The patients underwent a repeat scan within 1-4 years from the first scan and were not found to have chronic acalculous cholecystitis (CAC). Our standard fatty meal was composed of a 60-g Snickers chocolate bar and 200 ml full-fat yogurt. The mean {+-} SD values for GBEF1 and GBEF2 were 52{+-}17% and 52{+-}16%, respectively. There was a direct linear correlation between the values of GBEF1 and GBEF2 for the subjects, with a correlation coefficient of 0.509 (p=0.002). Subgroup data analysis of the volunteer group showed that there was significant linear correlation between volunteer values of GBEF1 and GBEF2, with a correlation coefficient of 0.473 (p=0.017). Subgroup data analysis of the non-CAC patient group showed no significant correlation between patient values of GBEF1 and GBEF2, likely due to limited sample size. This study showed that fatty meal CS is a reliable test in gallbladder motility evaluation and that GBEF measured by fatty meal CS is reproducible

  16. Interplanetary journey of a coronal mass ejection to Mars and to Comet 67P/Churyumov-Gerasimenko

    Science.gov (United States)

    Witasse, Olivier; Kajdic, Primoz; Sanchez-Cano, Beatriz; Mays, Leila; Lebreton, Jean-Pierre; Espley, Jared; Goetz, Charlotte; Richter, Ingo; Koenders, Christoph; Glassmeier, Karl-Heinz; Nilsson, Hans; Opgenoorth, Hermann; Andrews, David; Lester, Mark; Edberg, Niklas; Zouganelis, Yannis; Intzekara, Dimitra; Kuulkers, Erik; Turc, Lucile; Odstrcil, Dusan

    2016-04-01

    We discuss observations of a large coronal mass ejection (CME) ejected on 14 October 2014, which hit Mars on 17 October 2014, 1.5 days before the Mars close encounter with the Siding Spring comet. Clear disturbances of the Mars' upper atmosphere are identified in the Mars Express and MAVEN data sets. Interestingly, comet 67P/Churyumov-Gerasimenko was perfectly aligned with the Sun and Mars at 1.7 AU behind Mars, with the Rosetta spacecraft orbiting at 10 km above the cometary surface. The Rosetta plasma package and the radiation monitor detected the event on 22 October 2014. We describe the propagation of this CME from the Sun to Rosetta and show comparison with dedicated WSA-ENLIL (large-scale, physics-based prediction model of the heliosphere) simulations. CME effects on the Mars and comet 67P environments are reported. In particular, large and similar Forbush effects - a transient decrease followed by a gradual recovery in the observed galactic cosmic ray intensity- were observed at both places, as recorded by the MSL RAD instrument aboard the Curiosity rover at the surface of Mars and by the Radiation Environment Monitor aboard Rosetta. Fortuitously, the New Horizons spacecraft was also along the propagation direction of the CME, which can take 3-5 months to reach the distance of 31.7 AU. By the time the solar wind travels that far from the Sun, the fast solar wind parcels have interacted with slower wind parcels emitted at an earlier time along the same radial line. We investigate if the CME observed at Mars and Rosetta has a unique signature at New Horizons. This presents a challenge since many solar structures can either be worn down as they propagate, or they can merge into larger ones. We present also preliminary 3D WSA-ENLIL simulations out to 40 AU showing the evolution of the CME, including other CMEs during this period.

  17. Evaluation of Cardiac Function Index as Measured by Transpulmonary Thermodilution as an Indicator of Left Ventricular Ejection Fraction in Cardiogenic Shock

    Directory of Open Access Journals (Sweden)

    Jessica Perny

    2014-01-01

    Full Text Available Introduction. The PiCCO transpulmonary thermodilution technique provides two indices of cardiac systolic function, the cardiac function index (CFI and the global ejection fraction (GEF. Both appear to be correlated with left ventricular ejection fraction (LVEF measured by echocardiography in patients with circulatory failure, especially in septic shock. The aim of the present study was to test the reliability of CFI as an indicator of LVEF in patients with cardiogenic shock. Methods. In thirty-five patients with cardiogenic shock, we performed (i simultaneous measurements of echocardiography LVEF and cardiac function index assessed by transpulmonary thermodilution (n=72 and (ii transpulmonary thermodilution before/after increasing inotropic agents (n=18. Results. Mean LVEF was 31% (+/−11.7, CFI 3/min (+/−1, and GEF 14.2% (+/−6. CFI and GEF were both positively correlated with LVEF (P<0.0001, r2=0.27. CFI and GEF were significantly increased with inotropic infusion (resp., P=0.005, P=0.007. A cardiac function index <3.47/min predicted a left ventricular ejection fraction ≤35% (sensitivity 81.1% and specificity 63%. In patients with right ventricular dysfunction, CFI was not correlated with LVEF. Conclusion. CFI is correlated with LVEF provided that patient does not present severe right ventricular dysfunction. Thus, the PiCCO transpulmonary thermodilution technique is useful for the monitoring of inotropic therapy during cardiogenic shock.

  18. Space weather monitoring with neutron monitor measurements

    Energy Technology Data Exchange (ETDEWEB)

    Steigies, Christian [Christian-Albrechts-Universitaet zu Kiel (Germany)

    2013-07-01

    Space Weather affects many areas of the modern society, advance knowledge about space weather events is important to protect personnel and infrastructure. Cosmic Rays (CR) measurements by ground-based Neutron Monitors are influenced by Coronal Mass Ejections (CME), the intensity of the ever present Cosmic Rays is reduced in a Forbush decrease (Fd). In the case of very energetic CMEs, the measured intensity can be significantly increased in a Ground Level Enhancement (GLE). By detecting the anisotropy of the CR environment, a CME can be detected hours before it arrives at Earth. During a GLE the high-energy particles from the Sun can be detected before the more abundant lower energy particles arrive at Earth, thus allowing to take protective measures. Since the beginning of the Neutron Monitor Database (NMDB) project, which has been started in 2008 with funding from the European Commission, real-time data from Neutron Monitors around the world has been made available through one web-portal. We have more than doubled the number of stations providing data since the start of the project to now over 30 stations. The effectiveness of the ALERT applications which are based on NMDB data has been shown by the recent GLE71. We present different applications through which the measurements and different data products are accessible.

  19. Exercise hemodynamics in patients with and without diastolic dysfunction and preserved ejection fraction after myocardial infarction

    DEFF Research Database (Denmark)

    Andersen, Mads J; Ersbøll, Mads; Bro-Jeppesen, John

    2012-01-01

    Left ventricular diastolic dysfunction (DD) is common after myocardial infarction (MI) despite preservation of left ventricular ejection fraction, yet it remains unclear how or whether DD affects cardiac hemodynamics with stress....

  20. On pulsar-driven mass ejection in low-mass X-ray binaries

    Institute of Scientific and Technical Information of China (English)

    Lei Fu; Xiang-Dong Li

    2011-01-01

    There is accumulating evidence for mass ejection in low-mass X-ray binaries (LMXBs) driven by radio pulsar activity during X-ray quiescence.We consider the condition for mass ejection by comparing the radiation pressure from a millisecond pulsar,and the gas pressure at the inner Lagrange point or at the surrounding accretion disk.We calculate the critical spin period of the pulsar below which mass ejection is allowed.Combining with the evolution of the mass transfer rate,we present constraints on the orbital periods of the systems.We show that mass ejection could happen in both wide and compact LMXBs.It may be caused by transient accretion due to thermal instability in the accretion disks in the former,and irradiation-driven mass-transfer cycles in the latter.

  1. Improved Rock Core Sample Break-off, Retention and Ejection System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort advances the design of an innovative core sampling and acquisition system with improved core break-off, retention and ejection features. Phase 1...

  2. Improved Rock Core Sample Break-off, Retention and Ejection System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort advances the design of an innovative core sampling and acquisition system with improved core break-off, retention and ejection features. The...

  3. Impaired myocardial oxygen availability contributes to abnormal exercise hemodynamics in heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    van Empel, Vanessa P M; Mariani, Justin; Borlaug, Barry A; Kaye, David M

    2014-01-01

    BACKGROUND: Hypertension is a frequent risk factor for the development of heart failure with preserved ejection fraction (HFPEF). Progressive extracellular matrix accumulation has been presumed to be the fundamental pathophysiologic mechanism that leads to the transition to impaired diastolic reserv

  4. Individual and objective methods for preventing ejections in oil and gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Hoznek, I.

    1984-01-01

    The use of different methods for preventing ejections is noted and, along with an analysis of their effectiveness, attention is focused on the possibility of using a number of newer methods towards increasing labor safety.

  5. Mineralocorticoid receptor antagonists for heart failure with reduced ejection fraction : integrating evidence into clinical practice

    NARCIS (Netherlands)

    Zannad, Faiez; Stough, Wendy Gattis; Rossignol, Patrick; Bauersachs, Johann; McMurray, John J. V.; Swedberg, Karl; Struthers, Allan D.; Voors, Adriaan A.; Ruilope, Luis M.; Bakris, George L.; O'Connor, Christopher M.; Gheorghiade, Mihai; Mentz, Robert J.; Cohen-Solal, Alain; Maggioni, Aldo P.; Beygui, Farzin; Filippatos, Gerasimos S.; Massy, Ziad A.; Pathak, Atul; Pina, Ileana L.; Sabbah, Hani N.; Sica, Domenic A.; Tavazzi, Luigi; Pitt, Bertram

    2012-01-01

    Mineralocorticoid receptor antagonists (MRAs) improve survival and reduce morbidity in patients with heart failure, reduced ejection fraction (HFREF), and mild-to-severe symptoms, and in patients with left ventricular systolic dysfunction and heart failure after acute myocardial infarction. These

  6. Predictors and progression of aortic stenosis in patients with preserved left ventricular ejection fraction

    DEFF Research Database (Denmark)

    Ersbøll, Mads; Schulte, Phillip J; Al Enezi, Fawaz

    2015-01-01

    We aimed to characterize the hemodynamic progression of aortic stenosis (AS) in a contemporary unselected cohort of patients with preserved left ventricular ejection fraction. Current guidelines recommend echocardiographic surveillance of hemodynamic progression. However, limited data exist on th...

  7. Relationships between egg-recognition and egg-ejection in a grasp-ejector species

    Science.gov (United States)

    Soler, Manuel; Ruiz-Raya, Francisco; Roncalli, Gianluca; Ibáñez-Álamo, Juan Diego

    2017-01-01

    Brood parasitism frequently leads to a total loss of host fitness, which selects for the evolution of defensive traits in host species. Experimental studies have demonstrated that recognition and rejection of the parasite egg is the most common and efficient defence used by host species. Egg-recognition experiments have advanced our knowledge of the evolutionary and coevolutionary implications of egg recognition and rejection. However, our understanding of the proximate mechanisms underlying both processes remains poor. Egg rejection is a complex behavioural process consisting of three stages: egg recognition, the decision whether or not to reject the putative parasitic egg and the act of ejection itself. We have used the blackbird (Turdus merula) as a model species to explore the relationship between egg recognition and the act of egg ejection. We have manipulated the two main characteristics of parasitic eggs affecting egg ejection in this grasp-ejector species: the degree of colour mimicry (mimetic and non-mimetic, which mainly affects the egg-recognition stage of the egg-rejection process) and egg size (small, medium and large, which affects the decision to eject), while maintaining a control group of non-parasitized nests. The behaviour of the female when confronted with an experimental egg was filmed using a video camera. Our results show that egg touching is an indication of egg recognition and demonstrate that blackbirds recognized (i.e., touched) non-mimetic experimental eggs significantly more than mimetic eggs. However, twenty per cent of the experimental eggs were touched but not subsequently ejected, which confirms that egg recognition does not necessarily mean egg ejection and that accepting parasitic eggs, at least sometimes, is the consequence of acceptance decisions. Regarding proximate mechanisms, our results show that the delay in egg ejection is not only due to recognition problems as usually suggested, given that experimental eggs are not

  8. Laser in situ keratomileusis flap stability in an aviator following aircraft ejection.

    Science.gov (United States)

    Richmond, Christopher J; Barker, Patrick D; Levine, Edgar M; Hofmeister, Elizabeth M

    2016-11-01

    We present the case of a 28-year-old male F/A-18F Super Hornet naval flight officer who ejected from an aircraft at 13 000 feet at a speed in excess of 350 knots 7 years after uneventful laser in situ keratomileusis (LASIK). The patient was evaluated the day after the ejection. No LASIK flap complications or epithelial defects were found, and the corrected distance visual acuity was 20/15 in both eyes.

  9. Simulation of 3D Flow in Turbine Blade Rows including the Effects of Coolant Ejection

    Institute of Scientific and Technical Information of China (English)

    Jian-Jun LIU; Bai-Tao AN; Yun-Tao ZENG

    2008-01-01

    This paper describes the numerical simulation of three-dimensional viscous flows in air-cooled turbine blade rows with the effects of coolant ejection. A TVD Navier-Stokes flow solver incorporated with Baldwin-Lomax turbulence model and multi-grid convergence acceleration algorithm are used for the simulation. The influences of coolant ejection on the main flow are accounted by volumetric coolant source terms. Numerical results for a four-stage turbine are presented and discussed.

  10. The survival of patients with heart failure with preserved or reduced left ventricular ejection fraction

    DEFF Research Database (Denmark)

    Boesgaard, Søren

    2012-01-01

    A substantial proportion of patients with heart failure have preserved left ventricular ejection fraction (HF-PEF). Previous studies have reported mixed results whether survival is similar to those patients with heart failure and reduced EF (HF-REF).......A substantial proportion of patients with heart failure have preserved left ventricular ejection fraction (HF-PEF). Previous studies have reported mixed results whether survival is similar to those patients with heart failure and reduced EF (HF-REF)....

  11. Heart Failure with Preserved Ejection Fraction in the Elderly: Scope of the Problem

    OpenAIRE

    Upadhya, Bharathi; Taffet, George E.; Cheng, Che Ping; Kitzman, Dalane W.

    2015-01-01

    Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure (HF) in older adults, particularly women, and is increasing in prevalence as the population ages. With morbidity and mortality on par with HF with reduced ejection fraction, it remains a most challenging clinical syndrome for the practicing clinician and basic research scientist. Originally considered to be predominantly caused by diastolic dysfunction, more recent insights indicate that HFpEF in o...

  12. Understanding heart failure with preserved ejection fraction: where are we today?

    OpenAIRE

    van Heerebeek, L.; Paulus, W.J.

    2016-01-01

    Heart failure with preserved ejection fraction (HFpEF) represents a complex and heterogeneous clinical syndrome, which is increasingly prevalent and associated with poor outcome. In contrast to heart failure with reduced ejection fraction (HFrEF), modern heart failure pharmacotherapy did not improve outcome in HFpEF, which was attributed to incomplete understanding of HFpEF pathophysiology, patient heterogeneity and lack of insight into primary pathophysiological processes. HFpEF patients are...

  13. Assessment of poststress left ventricular ejection fraction by gated SPECT: comparison with equilibrium radionuclide angiocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Acampa, Wanda; Liuzzi, Raffaele; De Luca, Serena; Capasso, Enza; Luongo, Luca; Cuocolo, Alberto [University Federico II, Department of Biomorphological and Functional Sciences, Institute of Biostructures and Bioimages, National Council of Research, Naples (Italy); Caprio, Maria Grazia [University Federico II, Department of Biomorphological and Functional Sciences, Institute of Biostructures and Bioimages, National Council of Research, Naples (Italy); SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Nicolai, Emanuele [SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Petretta, Mario [University Federico II, Department of Clinical Medicine, Cardiovascular and Immunological Sciences, Naples (Italy)

    2010-02-15

    We compared left ventricular (LV) ejection fraction obtained by gated SPECT with that obtained by equilibrium radionuclide angiocardiography in a large cohort of patients. Within 1 week, 514 subjects with suspected or known coronary artery disease underwent same-day stress-rest {sup 99m}Tc-sestamibi gated SPECT and radionuclide angiocardiography. For both studies, data were acquired 30 min after completion of exercise and after 3 h rest. In the overall study population, a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.82, p<0.0001) and after stress (r=0.83, p<0.0001). In Bland-Altman analysis, the mean differences in ejection fraction (radionuclide angiocardiography minus gated SPECT) were -0.6% at rest and 1.7% after stress. In subjects with normal perfusion (n=362), a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.72, p<0.0001) and after stress (r=0.70, p<0.0001) and the mean differences in ejection fraction were -0.9% at rest and 1.4% after stress. Also in patients with abnormal perfusion (n=152), a good correlation between the two techniques was observed both at rest (r=0.89, p<0.0001) and after stress (r=0.90, p<0.0001) and the mean differences in ejection fraction were 0.1% at rest and 2.5% after stress. In a large study population, a good agreement was observed in the evaluation of LV ejection fraction between gated SPECT and radionuclide angiocardiography. However, in patients with perfusion abnormalities, a slight underestimation in poststress LV ejection fraction was observed using gated SPECT as compared to equilibrium radionuclide angiocardiography. (orig.)

  14. Left ventricular ejection fraction is determined by both global myocardial strain and wall thickness

    Directory of Open Access Journals (Sweden)

    David H. MacIver

    2015-06-01

    Conclusion: The findings of this study explain the coexistence of reduced global myocardial strain and normal ejection fraction seen in clinical observational studies. Our understanding of the pathophysiological processes in heart failure and associated conditions is substantially enhanced. These results provide a much better insight into the biophysical inter-relationship between myocardial strain and ejection fraction. This improved understanding provides an essential foundation for the design and interpretation of future clinical mechanistic and prognostic studies.

  15. Motion Law Analysis and Structural Optimization of the Ejection Device of Tray Seeder

    Science.gov (United States)

    Luo, Xin; Hu, Bin; Dong, Chunwang; Huang, Lili

    An ejection mechanism consisting four reset springs, an electromagnet and a seed disk was designed for tray seeder. The motion conditions of seeds in the seed disk were theoretical analyzed and intensity and height of seed ejection were calculated. The motions of the seeds and seed disk were multi-body dynamic simulated using Cosmos modules plug-in SolidWorks software package. The simulation results showed the consistence with the theoretical analysis.

  16. Rollover Car Crashes with Ejection: A Deadly Combination—An Analysis of 719 Patients

    Directory of Open Access Journals (Sweden)

    Rifat Latifi

    2014-01-01

    Full Text Available Rollover car crashes (ROCs are serious public safety concerns worldwide. Objective. To determine the incidence and outcomes of ROCs with or without ejection of occupants in the State of Qatar. Methods. A retrospective study of all patients involved in ROCs admitted to Level I trauma center in Qatar (2011-2012. Patients were divided into Group I (ROC with ejection and Group II (ROC without ejection. Results. A total of 719 patients were evaluated (237 in Group I and 482 in Group II. The mean age in Group I was lower than in Group II (24.3±10.3 versus 29±12.2; P=0.001. Group I had higher injury severity score and sustained significantly more head, chest, and abdominal injuries in comparison to Group II. The mortality rate was higher in Group I (25% versus 7%; P=0.001. Group I patients required higher ICU admission rate (P=0.001. Patients in Group I had a 5-fold increased risk for age-adjusted mortality (OR 5.43; 95% CI 3.11–9.49, P=0.001. Conclusion. ROCs with ejection are associated with higher rate of morbidity and mortality compared to ROCs without ejection. As an increased number of young Qatari males sustain ROCs with ejection, these findings highlight the need for research-based injury prevention initiatives in the country.

  17. Material ejection from shock-loaded free surfaces of aluminum and lead

    Energy Technology Data Exchange (ETDEWEB)

    Asay, J.R.

    1976-10-01

    A discussion is presented regarding interferometer experiments conducted on free surfaces which are impulsively loaded with high amplitude shock waves. It is shown that material ejection from shocked surfaces can significantly degrade interferometer experiments. In particular, loss of both light intensity and contrast of interferometer signals can result from various scattering and absorption processes occurring in a cloud of ejected material. An experimental technique is presented which allows determination of the mass and velocity of material ejected from free surfaces during shock loading. The technique has been applied to a study of mass ejection occurring naturally from shocked surfaces of two aluminium alloys and from lead. These results show that the total ejected mass ranges from a few ..mu..g/cm/sup 2/ in the aluminum alloys studied to a few mg/cm/sup 2/ in lead, for shock pressures ranging from about 10 to 50 GPa (100 to 500 kbar). Surface defects, such as pits and scratches, are thought to strongly influence mass ejection in aluminum; whereas in lead, localized shock-induced melting and vaporization are thought to be the dominant mechanisms at the higher shock pressures. Experimental results are also presented for aluminum surfaces which contain artificial defects in the form of wedge-shaped cavities. These results show that the maximum ejecta velocities of approximately two to four times the free surface velocity which are observed in these experiments can be correlated with predictions of steady jetting theory.

  18. Dynamical ejections of massive stars from young star clusters under diverse initial conditions

    CERN Document Server

    Oh, Seungkyung

    2016-01-01

    We study the effects of initial conditions of star clusters and their massive star population on dynamical ejections of stars from star clusters up to an age of 3 Myr, particularly focusing on massive systems, using a large set of direct N-body calculations for moderately massive star clusters (Mecl=$10^{3.5}$ Msun). We vary the initial conditions of the calculations such as the initial half-mass radius of the clusters, initial binary populations for massive stars and initial mass segregation. We find that the initial density is the most influential parameter for the ejection fraction of the massive systems. The clusters with an initial half-mass radius of 0.1 (0.3) pc can eject up to 50% (30)% of their O-star systems on average. Most of the models show that the average ejection fraction decreases with decreasing stellar mass. For clusters efficient at ejecting O stars, the mass function of the ejected stars is top-heavy compared to the given initial mass function (IMF), while the mass function of stars remai...

  19. Classification of the ejection mechanisms of charged macromolecules from liquid droplets

    Science.gov (United States)

    Consta, Styliani; Malevanets, Anatoly

    2013-01-01

    The relation between the charge state of a macromolecule and its ejection mechanism from droplets is one of the important questions in electrospray ionization methods. In this article, effects of solvent-solute interaction on the manifestation of the charge induced instability in a droplet are examined. We studied the instabilities in a prototype system of a droplet comprised of charged poly(ethylene glycol) and methanol, acetonitrile, and water solvents. We observed instances of three, previously only conjectured, [S. Consta, J. Phys. Chem. B 114, 5263 (2010), 10.1021/jp912119v] mechanisms of macroion ejection. The mechanism of ejection of charged macroion in methanol is reminiscent of "pearl" model in polymer physics. In acetonitrile droplets, the instability manifests through formation of solvent spines around the solvated macroion. In water, we find that the macroion is ejected from the droplet through contiguous extrusion of a part of the chain. The difference in the morphology of the instabilities is attributed to the interplay between forces arising from the macroion solvation energy and the surface energy of the droplet interface. For the contiguous extrusion of a charged macromolecule from a droplet, we demonstrate that the proposed mechanism leads to ejection of the macromolecule from droplets with sizes well below the Rayleigh limit. The ejected macromolecule may hold charge significantly higher than that suggested by prevailing theories. The simulations reveal new mechanisms of macroion evaporation that differ from conventional charge residue model and ion evaporation mechanisms.

  20. Pyroclast Tracking Velocimetry illuminates bomb ejection and explosion dynamics at Stromboli (Italy) and Yasur (Vanuatu) volcanoes

    Science.gov (United States)

    Gaudin, Damien; Taddeucci, Jacopo; Scarlato, Piergiorgio; Moroni, Monica; Freda, Carmela; Gaeta, Mario; Palladino, Danilo Mauro

    2014-07-01

    A new image processing technique—Pyroclast Tracking Velocimetry—was used to analyze a set of 30 high-speed videos of Strombolian explosions from different vents at Stromboli (Italy) and Yasur (Vanuatu) volcanoes. The studied explosions invariably appear to result from the concatenation of up to a hundred individual pyroclast ejection pulses. All these pulses share a common evolution over time, including (1) a non-linear decrease of the pyroclast ejection velocity, (2) an increasing spread of ejection angle, and (3) an increasing size of the ejected pyroclasts. These features reflect the dynamic burst of short-lived gas pockets, in which the rupture area enlarges while pressure differential decreases. We estimated depth of pyroclast release to be approximately 1 and 8 m below the surface at Stromboli and Yasur, respectively. In addition, explosions featuring more frequent pulses also have higher average ejection velocities and larger total masses of pyroclasts. These explosions release a larger overall amount of energy stored in the pressurized gas by a combination of more frequent and stronger ejection pulses. In this context, the associated kinetic energy per explosion, ranging 103-109 J appears to be a good proxy for the explosion magnitude. Differences in the pulse-defining parameters among the different vents suggest that this general process is modulated by geometrical factors in the shallow conduit, as well as magma-specific rheology. Indeed, the more viscous melt of Yasur, compared to Stromboli, is associated with larger vents producing fewer pulses but larger pyroclasts.

  1. Linear theory on temporal instability of megahertz faraday waves for monodisperse microdroplet ejection.

    Science.gov (United States)

    Tsai, Shirley C; Tsai, Chen S

    2013-08-01

    A linear theory on temporal instability of megahertz Faraday waves for monodisperse microdroplet ejection based on mass conservation and linearized Navier-Stokes equations is presented using the most recently observed micrometer- sized droplet ejection from a millimeter-sized spherical water ball as a specific example. The theory is verified in the experiments utilizing silicon-based multiple-Fourier horn ultrasonic nozzles at megahertz frequency to facilitate temporal instability of the Faraday waves. Specifically, the linear theory not only correctly predicted the Faraday wave frequency and onset threshold of Faraday instability, the effect of viscosity, the dynamics of droplet ejection, but also established the first theoretical formula for the size of the ejected droplets, namely, the droplet diameter equals four-tenths of the Faraday wavelength involved. The high rate of increase in Faraday wave amplitude at megahertz drive frequency subsequent to onset threshold, together with enhanced excitation displacement on the nozzle end face, facilitated by the megahertz multiple Fourier horns in resonance, led to high-rate ejection of micrometer- sized monodisperse droplets (>10(7) droplets/s) at low electrical drive power (<;1 W) with short initiation time (<;0.05 s). This is in stark contrast to the Rayleigh-Plateau instability of a liquid jet, which ejects one droplet at a time. The measured diameters of the droplets ranging from 2.2 to 4.6 μm at 2 to 1 MHz drive frequency fall within the optimum particle size range for pulmonary drug delivery.

  2. ON SUN-TO-EARTH PROPAGATION OF CORONAL MASS EJECTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying D. [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Luhmann, Janet G.; Moestl, Christian; Bale, Stuart D.; Lin, Robert P. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Lugaz, Noe [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States); Davies, Jackie A., E-mail: liuxying@ssl.berkeley.edu [Space Science and Technology Department, Rutherford Appleton Laboratory, Didcot (United Kingdom)

    2013-05-20

    We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts, and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation: (1) the Sun-to-Earth propagation of fast CMEs can be approximately formulated into three phases: an impulsive acceleration, then a rapid deceleration, and finally a nearly constant speed propagation (or gradual deceleration); (2) the CMEs studied here are still accelerating even after the flare maximum, so energy must be continuously fed into the CME even after the time of the maximum heating and radiation has elapsed in the corona; (3) the rapid deceleration, presumably due to interactions with the ambient medium, mainly occurs over a relatively short timescale following the acceleration phase; and (4) CME-CME interactions seem a common phenomenon close to solar maximum. Our comparison between different techniques (and data sets) has important implications for CME observations and their interpretations: (1) for the current cases, triangulation assuming a compact CME geometry is more reliable than triangulation assuming a spherical front attached to the Sun for distances below 50-70 solar radii from the Sun, but beyond about 100 solar radii we would trust the latter more; (2) a proper treatment of CME geometry must be performed in determining CME Sun-to-Earth kinematics, especially when the CME propagation direction is far away from the

  3. Phenotype-Specific Treatment of Heart Failure With Preserved Ejection Fraction: A Multiorgan Roadmap.

    Science.gov (United States)

    Shah, Sanjiv J; Kitzman, Dalane W; Borlaug, Barry A; van Heerebeek, Loek; Zile, Michael R; Kass, David A; Paulus, Walter J

    2016-07-05

    Heart failure (HF) with preserved ejection fraction (EF; HFpEF) accounts for 50% of HF cases, and its prevalence relative to HF with reduced EF continues to rise. In contrast to HF with reduced EF, large trials testing neurohumoral inhibition in HFpEF failed to reach a positive outcome. This failure was recently attributed to distinct systemic and myocardial signaling in HFpEF and to diversity of HFpEF phenotypes. In this review, an HFpEF treatment strategy is proposed that addresses HFpEF-specific signaling and phenotypic diversity. In HFpEF, extracardiac comorbidities such as metabolic risk, arterial hypertension, and renal insufficiency drive left ventricular remodeling and dysfunction through systemic inflammation and coronary microvascular endothelial dysfunction. The latter affects left ventricular diastolic dysfunction through macrophage infiltration, resulting in interstitial fibrosis, and through altered paracrine signaling to cardiomyocytes, which become hypertrophied and stiff because of low nitric oxide and cyclic guanosine monophosphate. Systemic inflammation also affects other organs such as lungs, skeletal muscle, and kidneys, leading, respectively, to pulmonary hypertension, muscle weakness, and sodium retention. Individual steps of these signaling cascades can be targeted by specific interventions: metabolic risk by caloric restriction, systemic inflammation by statins, pulmonary hypertension by phosphodiesterase 5 inhibitors, muscle weakness by exercise training, sodium retention by diuretics and monitoring devices, myocardial nitric oxide bioavailability by inorganic nitrate-nitrite, myocardial cyclic guanosine monophosphate content by neprilysin or phosphodiesterase 9 inhibition, and myocardial fibrosis by spironolactone. Because of phenotypic diversity in HFpEF, personalized therapeutic strategies are proposed, which are configured in a matrix with HFpEF presentations in the abscissa and HFpEF predispositions in the ordinate.

  4. Better Visual Outcome by Intraocular Lens Ejection in Geriatric Patients with Ruptured Ocular Injuries

    Science.gov (United States)

    Sugita, Tadasu; Tsunekawa, Taichi; Matsuura, Toshiyuki; Takayama, Kei; Yamamoto, Kentaro; Kachi, Shu; Ito, Yasuki; Ueno, Shinji; Nonobe, Norie; Kataoka, Keiko; Suzumura, Ayana; Iwase, Takeshi; Terasaki, Hiroko

    2017-01-01

    Ocular trauma is one of the leading causes of visual impairment worldwide. Because of the popularity of cataract surgeries, aged individuals with ocular trauma commonly have a surgical wound in their eyes. The purpose of this study was to evaluate the visual outcome of cases that were coincident with intraocular lens (IOL) ejection in the eyes with ruptured open-globe ocular injuries. Consecutive patients with open-globe ocular injuries were first reviewed. Patients’ characteristics, corrected distance visual acuities (CDVAs) over 3 years after the trauma, causes of injuries, traumatic wound patterns, and coexistence of retinal detachment were examined. The relationships between poor CDVA and the other factors, including the complications of crystalline lens and IOL ejection, were examined. A total of 105 eyes/patients [43 eyes with rupture, 33 with penetrating, 28 with intraocular foreign body (IOFB), and 1 with perforating injuries] were included. Rupture injuries were common in aged patients and were mostly caused by falls, whereas penetrating and IOFB injuries were common in young male patients. CDVAs of the eyes with rupture injuries were significantly worse than those of the eyes with penetrating or IOFB injuries. CDVA from more than 50% of the ruptured eyes resulted in no light perception or light perception to 20/500. CDVA of the ruptured eyes complicated by crystalline lens ejection was significantly worse than that of those complicated by IOL ejection. The wounds of the ruptured eyes complicated by IOL ejection were mainly located at the superior corneoscleral limbus, whereas those of the eyes complicated by crystalline lens ejection were located at the posterior sclera. There were significant correlations between poor CDVA and retinal detachment and crystalline lens ejection. These results proposed a new trend in the ocular injuries that commonly occur in aged patients; history of cataract surgery might affect the final visual outcome after open

  5. Value of left ventricular ejection fraction during exercise in predicting the extent of coronary artery disease.

    Science.gov (United States)

    DePace, N L; Iskandrian, A S; Hakki, A H; Kane, S A; Segal, B L

    1983-04-01

    To determine the relation between left ventricular performance during exercise and the extent of coronary artery disease, the results of exercise radionuclide ventriculography were analyzed in 65 patients who also underwent cardiac catheterization. A scoring system was used to quantitate the extent of coronary artery disease. This system takes into account the number and site of stenoses of the major coronary vessels and their secondary branches. The conventional method of interpreting the coronary angiograms indicated that 26 patients had significant coronary artery disease (defined as 70% or more narrowing of luminal diameter) of one vessel, 21 had multivessel disease and 18 had no significant coronary artery disease. Although the exercise left ventricular ejection fraction was significantly higher in patients with no coronary artery disease than in patients with one or multivessel disease (probability [p] less than 0.001), there was considerable overlap among the three groups. With the scoring system, a good correlation was found between the coronary artery disease score and the exercise left ventricular ejection fraction (r = -0.70; p less than 0.001). If the exercise heart rate was 130 beats/min or greater or the age of the patient was 50 years or less, an even better correlation was found (r = -0.73 and r = -0.82, respectively). The exercise ejection fraction (but not the change in ejection fraction, end-diastolic volume and end-systolic volume from rest to exercise) correlated with the extent of coronary artery disease. The exercise ejection fraction is the most important exercise variable that correlates with the extent of coronary artery disease when the latter is assessed quantitatively by a scoring system rather than the conventional method of reporting coronary angiograms. Young age and greater exercise heart rate strengthened the correlation. The change in ejection fraction from rest to exercise is useful in the diagnosis of coronary artery disease

  6. THE NATURE OF HYPERVELOCITY STARS AND THE TIME BETWEEN THEIR FORMATION AND EJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Cohen, Judith G., E-mail: wbrown@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu, E-mail: jlc@astro.caltech.edu [Palomar Observatory, Mail Stop 249-17, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-07-20

    We obtain Keck HIRES spectroscopy of HVS5, one of the fastest unbound stars in the Milky Way halo. We show that HVS5 is a 3.62 {+-} 0.11 M{sub Sun} main-sequence B star at a distance of 50 {+-} 5 kpc. The difference between its age and its flight time from the Galactic center is 105 {+-} 18 (stat) {+-}30 (sys) Myr; flight times from locations elsewhere in the Galactic disk are similar. This 10{sup 8} yr 'arrival time' between formation and ejection is difficult to reconcile with any ejection scenario involving massive stars that live for only 10{sup 7} yr. For comparison, we derive arrival times of 10{sup 7} yr for two unbound runaway B stars, consistent with their disk origin where ejection results from a supernova in a binary system or dynamical interactions between massive stars in a dense star cluster. For HVS5, ejection during the first 10{sup 7} yr of its lifetime is ruled out at the 3{sigma} level. Together with the 10{sup 8} yr arrival times inferred for three other well-studied hypervelocity stars (HVSs), these results are consistent with a Galactic center origin for the HVSs. If the HVSs were indeed ejected by the central black hole, then the Galactic center was forming stars {approx_equal}200 Myr ago, and the progenitors of the HVSs took {approx_equal}100 Myr to enter the black hole's loss cone.

  7. Activity associated with coronal mass ejections at solar minimum - SMM observations from 1984-1986

    Science.gov (United States)

    St. Cyr, O. C.; Webb, D. F.

    1991-01-01

    Seventy-three coronal mass ejections (CMEs) observed by the coronagraph aboard SMM between 1984 and 1986 were examined in order to determine the distribution of various forms of solar activity that were spatially and temporally associated with mass ejections during solar minimum phase. For each coronal mass ejection a speed was measured, and the departure time of the transient from the lower corona estimated. Other forms of solar activity that appeared within 45 deg longitude and 30 deg latitude of the mass ejection and within +/-90 min of its extrapolated departure time were explored. The statistical results of the analysis of these 73 CMEs are presented, and it is found that slightly less than half of them were infrequently associated with other forms of solar activity. It is suggested that the distribution of the various forms of activity related to CMEs does not change at different phases of the solar cycle. For those CMEs with associations, it is found that eruptive prominences and soft X-rays were the most likely forms of activity to accompany the appearance of mass ejections.

  8. Probability of rebound and eject of sand particles in wind-blown sand movement

    Institute of Scientific and Technical Information of China (English)

    Li Xie; Xiaojing Zheng

    2007-01-01

    When incident particles impact into a sand bed in wind-blown sand movement, rebound of the incident particles and eject of the sand particles by the incident particles affect directly the development of wind sand flux. In order to obtain rebound and eject lift-off probability of the sand particles, we apply the particle-bed stochastic collision model presented in our pervious works to derive analytic solutions of velocities of the incident and impacted particles in the postcollision bed. In order to describe randomness inherent in the real particle-bed collision, we take the incident angle, theimpact position and the direction of resultant action of sand particles in sand bed on the impacted sand particle as random variables, and calculate the rebound and eject velocities,angles and coefficients (ratio of rebound and eject velocity to incident velocity). Numerical results are found in accordance with current experimental results. The rebound and eject lift-off probabilities versus the incident and creeping velocities are predicted.

  9. Effect of arc current on droplet ejection from tungsten-based electrode in multiphase AC arc

    Science.gov (United States)

    Hashizume, Taro; Tanaka, Manabu; Watanabe, Takayuki

    2017-05-01

    The dynamic behavior of droplet ejection from a tungsten electrode was successfully visualized using a high-speed camera and an appropriate band-pass filter. The effect of arc current on droplet ejection was investigated to understand the electrode erosion mechanism in the multiphase AC arc. The rate of erosion by droplet ejection increased with increasing current. This result was examined on the basis of the time variation in forces on a pending droplet at the electrode tip during the AC cycle. The relationship among electromagnetic force, surface tension, and ion pressure on the molten tip during the cathodic period is crucial for controling droplet ejection. The molten tip becomes hemispherical forming the pending droplet with an increase in the instantaneous value of arc current during the AC cycle. The pending droplet detaches from the electrode surface when electromagnetic force becomes the dominant force. Consequently, a higher rate of erosion by droplet ejection with a higher arc current resulted from a stronger electromagnetic force.

  10. Ejection of the corona at State transitions: a common behaviour in microquasars?

    CERN Document Server

    Prat, Lionel

    2009-01-01

    The onset of most microquasar outbursts is characterized by a state transition between a Low/Hard State (LHS) and a High/Soft State (HSS). Besides drastic spectral and timing changes, this transition often shows a discrete ejection event detectable in the radio range. However, the exact nature of the ejected material and the mechanisms that give birth to these phenomena are yet to be unraveled. Recent simultaneous radio and X-ray observations on several sources point to a coronal nature of the ejected material. In the cases of GRS 1915+105, XTE J1550-564, and the 2002 outburst of GX 339-4, the flux of the Compton component decreases sharply just before an ejection is detected in the radio range. Finally, in the case of H1743-322, drastic physical changes occurred in the corona just before the state transition, compatible with the disappearance of part of this medium. Thus, the behaviour of at least 4 microquasars points in the direction of an ejection of the corona at the state transition, feature that is yet...

  11. Clinical utility of semi-automated estimation of ejection fraction at the point-of-care

    DEFF Research Database (Denmark)

    Frederiksen, Christian Alcaraz; Juhl-Olsen, Peter; Hermansen, Johan Fridolf

    2015-01-01

    INTRODUCTION: To compare estimation of ejection fraction at the bedside by AutoEF compared with conventional methods and to assess feasibility and time consumption. METHODS: A total of 102 relatively hemodynanically stable mixed medical and surgical patients were included. All patients underwent...... ultrasonography of the heart at the bedside performed by a novice examiner. Three assessments of ejection fraction were made: 1) Expert eyeballing by a single specialist in cardiology and expert in echocardiography; 2) Manual planimetry by an experienced examiner; 3) AutoEF by a novice examiner with limited...... experience in echocardiography. RESULTS: Expert eyeballing of ejection fraction was performed in 100% of cases. Manual planimetry was possible in 89% of cases and AutoEF was possible in 83% of cases. The correlation between expert eyeballing and AutoEF was r=0.82, p manual planimetry...

  12. Determination of ejection velocity of rock fragments during rock burst in consideration of damage

    Institute of Scientific and Technical Information of China (English)

    ZUO Yu-jun; LI Xi-bing; ZHOU Zi-long

    2005-01-01

    The ejection velocity of rock fragments during rock burst, one of the important indexes representing the rock burst strength, is used most conveniently in the supporting design of tunnel with rock burst tendency and is often determined by means of observation devices. In order to calculate the average ejection velocity of rock fragments theoretically, the energy of rock burst was divided into damage consuming energy and kinetic energy gained by unit volume of rock firstly, and then the rock burst kinetic proportional coefficient η was brought up which could be determined according to the rock-burst damage energy index WD , at last the expression of the average ejection velocity of rock fragments during rock burst was obtained and one deep level underground tunnel was researched using the mentioned method. The results show that the calculation method is valid with or without considering the tectonic stress of tunnels, and that the method can be a reference for supporting design of deep mining.

  13. Chip-ejection interference in cutting processes of modern cutting tools

    Institute of Scientific and Technical Information of China (English)

    师汉民

    1999-01-01

    Based on the “principle of minimum energy”, the basic characteristics of non-free cutting are studied; the phenomenon and the nature of chip-ejection interference commonly existing in the cutting process of modem cutting tools are explored. A "synthesis method of elementary cutting tools" is suggested for modeling the cutting process of modem complex cutting tools. The general equation governing the chip-ejection motion is deduced. Real examples of non-free cutting are analyzed and the theoretically predicted results are supported by the experimental data or facts. The sufficient and necessary conditions for eliminating chip-ejection interference and for realizing free cutting are given; the idea and the technical approach of "the principle of free cutting" are also discussed, and a feasible way for improving or optimizing the cutting performance of modem cutting tools is, therefore, found.

  14. Effect of shock wave risetime on material ejection from aluminum surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Asay, J.R.

    1977-09-15

    The effect of shock wave risetime on material ejection in aluminum has been studied for loading stresses of 21 GPa. Uniform loading was accomplished with plate impact techniques by mounting specimens on a ramp wave generator. Projectile impact on one side of the wave generator produced a wave which dispersed with propagation distance. This wave was then made incident to an aluminum specimen, so that the specimen experienced non-shock loading. It was found that mass ejection from aluminum surfaces can be reduced by over two orders of magnitude relative to shock loading conditions by accelerating the surface with a wave risetime greater than about 35 ns. These results suggest an explanation for the apparent discrepancies which are sometimes observed in mass ejection measurements utilizing either plate impact or electron beam deposition to generate stress waves.

  15. Model for estimating the effects of surface roughness on mass ejection from shocked materials

    Energy Technology Data Exchange (ETDEWEB)

    Asay, J R; Bertholf, L D

    1978-10-01

    A statistical model is presented for estimating the effects of surface roughness on mass ejection from shocked surfaces. In the model, roughness is characterized by the total volume of defects, such as pits, scratches and machine marks, on a surface. The amount of material ejected from these defects during shock loading can be estimated by assuming that jetting from surface depressions is the primary mode of ejection and by making simplifying assumptions about jetting processes. Techniques are discussed for estimating the effects of distribution in defect size and shape, and results are presented for several different geometries of defects. The model is used to compare predicted and measured ejecta masses from six different materials. Surface defects in these materials range from pits and scratches on polished surfaces to prepared defects such as machined or porous surfaces. Good agreement is achieved between predicted and measured results which suggests general applicability of the model.

  16. Quantitative uncertainty and sensitivity analysis of a PWR control rod ejection accident

    Energy Technology Data Exchange (ETDEWEB)

    Pasichnyk, I.; Perin, Y.; Velkov, K. [Gesellschaft flier Anlagen- und Reaktorsicherheit - GRS mbH, Boltzmannstasse 14, 85748 Garching bei Muenchen (Germany)

    2013-07-01

    The paper describes the results of the quantitative Uncertainty and Sensitivity (U/S) Analysis of a Rod Ejection Accident (REA) which is simulated by the coupled system code ATHLET-QUABOX/CUBBOX applying the GRS tool for U/S analysis SUSA/XSUSA. For the present study, a UOX/MOX mixed core loading based on a generic PWR is modeled. A control rod ejection is calculated for two reactor states: Hot Zero Power (HZP) and 30% of nominal power. The worst cases for the rod ejection are determined by steady-state neutronic simulations taking into account the maximum reactivity insertion in the system and the power peaking factor. For the U/S analysis 378 uncertain parameters are identified and quantified (thermal-hydraulic initial and boundary conditions, input parameters and variations of the two-group cross sections). Results for uncertainty and sensitivity analysis are presented for safety important global and local parameters. (authors)

  17. Synergistic effects in radiation-induced particle ejection from solid surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Noriaki (Nagoya Univ. (Japan). Dept. of Physics)

    1990-01-01

    A description is given on radiation-induced particle ejection from solid surfaces, emphasizing synergistic effects arising from multi-species particle irradiation and from irradiation under complex environments. First, it is pointed out that synergisms can be treated by introducing the effects of material modification on radiation-induced particle ejection. As examples of the effects of surface modification on the sputtering induced by elastic encounters, sputtering of alloys and chemical sputtering of graphite are briefly discussed. Then the particle ejection induced by electronic encounters is explained emphasizing the difference in the behaviors from materials to materials. The possible synergistic effects of electronic and elastic encounters are also described. Lastly, we point out the importance of understanding the elementary processes of material-particle interaction and of developing computer codes describing material behaviors under irradiation. (author).

  18. COMET 22P/KOPFF: DUST ENVIRONMENT AND GRAIN EJECTION ANISOTROPY FROM VISIBLE AND INFRARED OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Fernando; Pozuelos, Francisco; Aceituno, Francisco; Casanova, Victor; Sota, Alfredo [Instituto de Astrofisica de Andalucia, CSIC, Glorieta de la Astronomia s/n, 18008 Granada (Spain); Castellano, Julio; Reina, Esteban, E-mail: fernando@iaa.es [Amateur Association Cometas-Obs (Spain)

    2012-06-20

    We present optical observations and Monte Carlo models of the dust coma, tail, and trail structures of the comet 22P/Kopff during the 2002 and 2009 apparitions. Dust loss rates, ejection velocities, and power-law size distribution functions are derived as functions of the heliocentric distance using pre- and post-perihelion imaging observations during both apparitions. The 2009 post-perihelion images can be accurately fitted by an isotropic ejection model. On the other hand, strong dust ejection anisotropies are required to fit the near-coma regions at large heliocentric distances (both inbound at r{sub h} = 2.5 AU and outbound at r{sub h} = 2.6 AU) for the 2002 apparition. These asymmetries are compatible with a scenario where dust ejection is mostly seasonally driven, coming mainly from regions near subsolar latitudes at far heliocentric distances inbound and outbound. At intermediate to near-perihelion heliocentric distances, the outgassing would affect much more extended latitude regions, the emission becoming almost isotropic near perihelion. We derived a maximum dust production rate of 260 kg s{sup -1} at perihelion, and an averaged production rate over one orbit of 40 kg s{sup -1}. An enhanced emission rate, also accompanied by a large ejection velocity, is predicted at r{sub h} > 2.5 pre-perihelion. The model has also been extended to the thermal infrared in order to be applied to available trail observations of this comet taken with IRAS and Infrared Space Observatory spacecrafts. The modeled trail intensities are in good agreement with those observations, which is remarkable taking into account that those data are sensitive to dust ejection patterns corresponding to several orbits before the 2002 and 2009 apparitions.

  19. Left-ventricular peak ejection rate, filling rate, and ejection fraction--frame rate requirements at rest and exercise: concise communication.

    Science.gov (United States)

    Bacharach, S L; Green, M V; Borer, J S; Hyde, J E; Farkas, S P; Johnston, G S

    1979-03-01

    The effect of framing rate on the measurement of left-ventricular (LV) ejection fraction (EF), peak ejection rate (PER), and peak filling rate (PFR) was evaluated at rest and during exercise in 11 normal subjects and 21 patients who underwent gated equilibrium blood-pool imaging. Left-ventricular time-activity curves were obtained in each subject, at rest and during stress, at temporal resolutions of 10, 20, 30, 40, and 50 msec per frame. Ejection fraction, PER, and PFR were determined for each frame duration. By observing changes in the measured values of these quantities with framing rate we conclude that: a) for the measurement of EF, 50 msec per frame at rest and 40 msec per frame at exercise is sufficient; b) PER requires 40 msec per frame at rest and 20 msec per frame during exercise; and c) for the measurement of PFR, at least 40 msec per frame at rest and 20 msec per frame during exercise are needed. These results should hold for both first-pass and gated equilibrium studies.

  20. Tolvaptan Improves the Long-Term Prognosis in Patients With Congestive Heart Failure With Preserved Ejection Fraction as Well as in Those With Reduced Ejection Fraction.

    Science.gov (United States)

    Imamura, Teruhiko; Kinugawa, Koichiro

    2016-09-28

    Tolvaptan (TLV), an arginine vasopressin type 2 antagonist, has been shown to play a role in ameliorating symptomatic congestion and normalizing diluted hyponatremia in patients with congestive heart failure (HF). However, most evidence was derived from patients with HF with reduced ejection fraction (HFrEF), and the clinical efficacy of TLV in patients with HF with preserved ejection fraction (HFpEF) remains uncertain. In this study, we retrospectively enrolled 60 in-hospital patients with stage D HF, who had received TLV to treat symptomatic congestion at our institute between 2011 and 2013. As a control group, we also enrolled 60 background-matched HF patients who did not receive TLV therapy. Patients with HFpEF (n = 29), whose left ventricular ejection fraction was > 45%, had higher age and a lower urine aquaporin-2 level relative to the plasma arginine vasopressin concentration compared with those with HFrEF (n = 91). TLV therapy significantly reduced the 2-year readmission rates in both the HFrEF and HFpEF populations (P < 0.05 for both), indicating that TLV therapy may improve the long-term prognosis not only in patients with HFrEF but also in those with HFpEF.

  1. Iontophoretic drug delivery across the nail.

    Science.gov (United States)

    Delgado-Charro, Maria Begoña

    2012-01-01

    Topical drug delivery to treat nail diseases such as onychomycosis and psoriasis is receiving increasing attention. Topical nail delivery is challenged by the complicated structure of the nail and the low permeability of most drugs across the nail plate. Considerable effort has been directed at developing methods to promote drug permeation across the nail plate. Iontophoresis efficiently enhances molecular transport across the skin and the eye and is now being tested for its potential in ungual delivery. This review covers the basic mechanisms of transport (electro-osmosis and -migration) and their relative contribution to nail iontophoresis as well as the key factors governing nail permselectivity and ionic transport numbers. Methodological issues concerning research in this area are summarized. The data available in vivo on nail iontophoresis of terbinafine specifically are reviewed in separate sections. Our understanding of nail iontophoresis has improved considerably since 2007; most decisively, the feasibility of nail iontophoresis in vivo has been clearly demonstrated. Future work is required to establish the adequate implementation of the technique so that its clinical efficacy to treat onychomycosis and nail psoriasis can be unequivocally determined.

  2. Ejection fraction and outcomes in patients with atrial fibrillation and heart failure

    DEFF Research Database (Denmark)

    Banerjee, Amitava; Taillandier, Sophie; Olesen, Jonas Bjerring;

    2012-01-01

    Heart failure (HF) increases the risk of stroke and thrombo-embolism (TE) in non-valvular atrial fibrillation (NVAF), and is incorporated in stroke risk stratification scores. We aimed to establish the role of ejection fraction (EF) in risk prediction in patients with NVAF and HF.......Heart failure (HF) increases the risk of stroke and thrombo-embolism (TE) in non-valvular atrial fibrillation (NVAF), and is incorporated in stroke risk stratification scores. We aimed to establish the role of ejection fraction (EF) in risk prediction in patients with NVAF and HF....

  3. Novel plasma and imaging biomarkers in heart failure with preserved ejection fraction

    Directory of Open Access Journals (Sweden)

    Prathap Kanagala

    2015-12-01

    Full Text Available Existing diagnostic guidelines for heart failure with preserved ejection fraction (HFPEF primarily comprise natriuretic peptides and echocardiographic assessment, highlighting the role of diastolic dysfunction. However, recent discoveries of novel plasma markers implicated in pathophysiology of heart failure and technological advances in imaging provide additional biomarkers which are potentially applicable to HFPEF. The evidence base for plasma extra-cellular matrix (ECM peptides, galectin-3, ST2, GDF-15 and pentraxin-3 is reviewed. Furthermore, the capabilities of novel imaging techniques to assess existing parameters (e.g. left ventricular ejection fraction, systolic & diastolic function, chamber size and additional derangements of the ECM, myocardial mechanics and ischaemia evaluation are addressed.

  4. Impact of ejection fraction on the clinical response to cardiac resynchronization therapy in mild heart failure

    DEFF Research Database (Denmark)

    Linde, Cecilia; Daubert, Claude; Abraham, William T;

    2013-01-01

    Current guidelines recommend cardiac resynchronization therapy (CRT) in mild heart failure (HF) patients with QRS prolongation and ejection fraction (EF) ≤30%. To assess the effect of CRT in less severe systolic dysfunction, outcomes in the REsynchronization reVErses Remodeling in Systolic left v...

  5. Ejection of Hyper-Velocity Stars from the Galactic Centre by Intermediate-Mass Black Holes

    CERN Document Server

    Baumgardt, H; Zwart, S P; Baumgardt, Holger; Gualandris, Alessia; Zwart, Simon Portegies

    2006-01-01

    We have performed N-body simulations of the formation of hyper-velocity stars (HVS) in the centre of the Milky Way due to inspiralling intermediate-mass black holes (IMBHs). We considered IMBHs of different masses, all starting from circular orbits at an initial distance of 0.1 pc. We find that the IMBHs sink to the centre of the Galaxy due to dynamical friction, where they deplete the central cusp of stars. Some of these stars become HVS and are ejected with velocities sufficiently high to escape the Galaxy. Since the HVS carry with them information about their origin, in particular in the moment of ejection, the velocity distribution and the direction in which they escape the Galaxy, detecting a population of HVS will provide insight in the ejection processes and could therefore provide indirect evidence for the existence of IMBHs. Our simulations show that HVS are generated in short bursts which last only a few Myrs until the IMBH is swallowed by the supermassive black hole (SMBH). HVS are ejected almost i...

  6. A study on the core analysis methodology for SMART CEA ejection accident-I

    Energy Technology Data Exchange (ETDEWEB)

    Zee, Sung Kyun; Lee, Chung Chan; Kim, Kyo Yoon; Cho, Byung Oh

    1999-04-01

    A methodology to analyze the fuel enthalpy is developed based on MASTER that is a time dependent 3 dimensional core analysis code. Using the proposed methodology, SMART CEA ejection accident is analyzed. Moreover, radiation doses are estimated at the exclusion area boundary and low population zone to confirm the criteria for the accident. (Author). 31 refs., 13 tabs., 18 figs.

  7. Impact on porous targets: penetration, crater formation, target compaction, and ejection.

    Science.gov (United States)

    Ringl, Christian; Bringa, Eduardo M; Urbassek, Herbert M

    2012-12-01

    Using a granular-mechanics code, we study the impact of a sphere into a porous adhesive granular target, consisting of monodisperse silica grains. The model includes elastic repulsive, adhesive, and dissipative forces, as well as sliding, rolling, and twisting friction. Impact velocities of up to 30 m/s and target filling factors (densities) between 19% and 35% have been systematically studied. We find that the projectile is stopped by an effective drag force which is proportional to the square of its velocity. Target adhesion influences projectile stopping only below a critical velocity, which increases with adhesion. The penetration depth depends approximately logarithmically on the impact velocity and is inversely proportional to the target density. The excavated crater is of conical form and is surrounded by a compaction zone whose width increases but whose maximum value decreases with increasing target density. Grain ejection increases in proportion with impactor velocity. Grains are ejected which have originally been buried to a depth of 8R(grain) below the surface; the angular distribution favors oblique ejection with a maximum around 45°. The velocity distribution of ejected grains features a broad low-velocity maximum around 0.5-1 m/s but exhibits a high-velocity tail up to ~15% of the projectile impact velocity.

  8. Injury pattern as an indication of seat belt failure in ejected vehicle occupants.

    Science.gov (United States)

    Freeman, Michael D; Eriksson, Anders; Leith, Wendy

    2014-09-01

    Prior authors have suggested that when occupant ejection occurs in association with a seat belt failure, entanglement of the outboard upper extremity (OUE) with the retracting shoulder belt will invariably occur, leaving injury pattern evidence of belt use. In the present investigation, the authors assessed this theory using data accessed from the NASS-CDS for ejected front seat occupants of passenger vehicles. Logistic regression models were used to assess the associations between seat belt failure status and injuries. Injury types associated with seat belt failure were significant OUE and head injuries (OR = 3.87, [95% CI 1.2, 13.0] and 3.1, [95% CI 1.0, 9.7], respectively). The two injury types were found to be a predictor of seat belt use and subsequent failure only if combined with a high (≥0.8) precrash probability of belt use. The injury pattern associated with a seat belt failure-related ejection has limited use in the forensic investigation of crash-related ejections.

  9. Angular distribution of electrons ejected by charged particles. IV. Combined classical and quantum-mechanical treatment

    NARCIS (Netherlands)

    Boesten, L.G.J.; Bonsen, T.F.M.

    1975-01-01

    Angular distributions of electrons ejected from helium by 100 and 300 keV protons have been calculated by a method which is a comination of the classical three-body collision theory and the quantum-mechanical Born approximation. The results of this theory have been compared with the corresponding ex

  10. Comparative Influences of Fluid and Shell on Modeled Ejection Performance of a Piezoelectric Micro-Jet

    Directory of Open Access Journals (Sweden)

    Kai Li

    2017-01-01

    Full Text Available The piezoelectric micro-jet, which can achieve the drop-on-demand requirement, is based on ink-jet technology and small droplets can be ejected out by precise control. The droplets are driven out of the nozzle by the acoustic pressure waves which are generated by the piezoelectric vibrator. The propagation processes of the acoustic pressure waves are affected by the acoustic properties of the fluid and the shell material of the micro-jet, as well as the excitations and the structure sizes. The influences of the fluid density and acoustic velocity in the fluid on the nozzle pressure and support reaction force of the vibrator are analyzed in this paper. The effects of the shell material on the ejection performance are studied as well. In order to improve the ejection performance of the micro-jet, for ejecting a given fluid, the recommended methods of selecting the shell material and adjusting excitations are provided based on the results, and the influences of the factors on working frequencies are obtained as well.

  11. The Nature of Hypervelocity Stars and the Time Between Their Formation and Ejection

    CERN Document Server

    Brown, Warren R; Geller, Margaret J; Kenyon, Scott J

    2012-01-01

    We obtain Keck HIRES spectroscopy of HVS5, one of the fastest unbound stars in the Milky Way halo. We show that HVS5 is a 3.62 +- 0.11 Msun main sequence B star at a distance of 50 +- 5 kpc. The difference between its age and its flight time from the Galactic center is 105 +-18(stat)+-30(sys) Myr; flight times from locations elsewhere in the Galactic disk are similar. This 10^8 yr `arrival time' between formation and ejection is difficult to reconcile with any ejection scenario involving massive stars that live for only 10^7 yr. For comparison, we derive arrival times of 10^7 yr for two unbound runaway B stars, consistent with their disk origin where ejection results from a supernova in a binary system or dynamical interactions between massive stars in a dense star cluster. For HVS5, ejection during the first 10^7 yr of its lifetime is ruled out at the 3-sigma level. Together with the 10^8 yr arrival times inferred for three other well-studied hypervelocity stars (HVSs), these results are consistent with a Ga...

  12. The Solar Atmosphere at Three Temperatures During a Coronal Mass Ejection

    Science.gov (United States)

    Zhitnik, I.; Pertzov, A.; Oparin, S.; Oraevsky, V.; Slemzin, V.; Sobelman, I.; Feynman, J.; Goldstein, B.

    1998-01-01

    On April 14, 1994 a major coronal mass ejection (CME) occured while the solar atmosphere was being observed in XUV by the Terek C instrument aboard the CORONAS spacecraft. We here compare the TEREK data before and after the CME with the Yohkoh soft x-ray data and the National Solar Observatory He I 10830 data from April 13 and 14.

  13. Association between Hypotension, Low Ejection Fraction and Cognitive Performance in Cardiac Patients

    Directory of Open Access Journals (Sweden)

    Rebecca F. Gottesman

    2010-01-01

    Full Text Available Background and Purpose: Impaired cardiac function can adversely affect the brain via decreased perfusion. The purpose of this study was to determine if cardiac ejection fraction (EF is associated with cognitive performance, and whether this is modified by low blood pressure.

  14. Ejection Systems and the Human Factor: A Guide for Flight Surgeons and Aeromedical Trainers

    Science.gov (United States)

    1988-05-01

    from when I regained consciousness, as soon as I realised where I was, there was a lot of pain in the leg..." b. CF104: (Ejection at 400 KIAS, 3,500 feet...201-209. 31. YEAGER, R.R.; Gross Behaviour of the Body’s Gluteal Region; Technology Inc; Dayton, Ohio, December 1971. 32. ZELLER, AF.; Human Reaction

  15. Rapid estimation of left ventricular ejection fraction in acute myocardial infarction by echocardiographic wall motion analysis

    DEFF Research Database (Denmark)

    Berning, J; Rokkedal Nielsen, J; Launbjerg, J

    1992-01-01

    Echocardiographic estimates of left ventricular ejection fraction (ECHO-LVEF) in acute myocardial infarction (AMI) were obtained by a new approach, using visual analysis of left ventricular wall motion in a nine-segment model. The method was validated in 41 patients using radionuclide...

  16. High-resolution imaging of ejection dynamics in laser-induced forward transfer

    NARCIS (Netherlands)

    Pohl, R.; Visser, C.W.; Römer, G.R.B.E.; Sun, C.; Huis in 't Veld, A.J.; Lohse, D.; Nakata, Yoshiki; Xianfan, Xianfan; Roth, Stephan; Neuenschwander, Beat

    2014-01-01

    Laser-induced Forward Transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials. As the ejection mechanism of picosecond LIFT has not been visualized in detail, the governing physics are not fully understood yet. Therefore, this article presents an experimental

  17. Imaging of the ejection process of nanosecond laser-induced forward transfer of gold

    NARCIS (Netherlands)

    Pohl, R.; Visser, C.W.; Römer, G.R.B.E.; Sun, C.; Huis in 't Veld, A.J.; Lohse, D.

    2014-01-01

    Laser-induced forward transfer is a direct-write process suitable for high precision 3D printing of several materials. However, the driving forces related to the ejection mechanism of the donor ma-terial are still under debate. So far, most of the experimental studies of nanosecond LIFT, are based o

  18. Mineralocorticoid receptor antagonists for heart failure with reduced ejection fraction : integrating evidence into clinical practice

    NARCIS (Netherlands)

    Zannad, Faiez; Stough, Wendy Gattis; Rossignol, Patrick; Bauersachs, Johann; McMurray, John J. V.; Swedberg, Karl; Struthers, Allan D.; Voors, Adriaan A.; Ruilope, Luis M.; Bakris, George L.; O'Connor, Christopher M.; Gheorghiade, Mihai; Mentz, Robert J.; Cohen-Solal, Alain; Maggioni, Aldo P.; Beygui, Farzin; Filippatos, Gerasimos S.; Massy, Ziad A.; Pathak, Atul; Pina, Ileana L.; Sabbah, Hani N.; Sica, Domenic A.; Tavazzi, Luigi; Pitt, Bertram

    2012-01-01

    Mineralocorticoid receptor antagonists (MRAs) improve survival and reduce morbidity in patients with heart failure, reduced ejection fraction (HFREF), and mild-to-severe symptoms, and in patients with left ventricular systolic dysfunction and heart failure after acute myocardial infarction. These cl

  19. High-resolution imaging of ejection dynamics in laser-induced forward transfer

    NARCIS (Netherlands)

    Pohl, Ralph; Visser, C.W.; Römer, Gerardus Richardus, Bernardus, Engelina; Sun, C.; Huis in 't Veld, Bert; Lohse, Detlef; Nakata, Yoshiki; Xianfan, Xianfan; Roth, Stephan; Neuenschwander, Beat

    2014-01-01

    Laser-induced Forward Transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials. As the ejection mechanism of picosecond LIFT has not been visualized in detail, the governing physics are not fully understood yet. Therefore, this article presents an experimental

  20. On Retaining the Seat Pack After Ejection when Landing in Trees

    Science.gov (United States)

    2010-11-01

    escape over the past 20 years works at the Aerospace Engineering Test Establishment ( AETE ) in Cold Lake. Therefore, it was unclear how complete the...equipment use & utility, rations, materials found, first aid, shelter, travel. H. Rescue WFSO Aircraft signals use & performance ( visual ...ACES II Second generation advanced concept ejection seat AETE Aerospace Engineering and Test Establishment AFP Rdns Aerospace and Force Protection

  1. The role of aerodynamic drag in propagation of interplanetary coronal mass ejections

    DEFF Research Database (Denmark)

    Vršnak, B.; Žic, T.; Falkenberg, Thea Vilstrup;

    2010-01-01

    Context. The propagation of interplanetary coronal mass ejections (ICMEs) and the forecast of their arrival on Earth is one of the central issues of space weather studies. Aims. We investigate to which degree various ICME parameters (mass, size, take-off speed) and the ambient solar-wind paramete...

  2. Ethyl Radical Ejection During Photodecomposition of Butanone on TiO2(110)

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Michael A.

    2008-10-15

    The photodecomposition of acetone and butanone were examined on the (110) surface of rutile TiO2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was proceeded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in a diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater thermal stability of the ethyl radical over that of the methyl radical. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO2(110) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed a preference for dehydrogenation to ethene through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO2 surface. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  3. Predicting Heart Failure With Preserved and Reduced Ejection Fraction : The International Collaboration on Heart Failure Subtypes

    NARCIS (Netherlands)

    Ho, Jennifer E; Enserro, Danielle; Brouwers, Frank P; Kizer, Jorge R; Shah, Sanjiv J; Psaty, Bruce M; Bartz, Traci M; Santhanakrishnan, Rajalakshmi; Lee, Douglas S; Chan, Cheeling; Liu, Kiang; Blaha, Michael J; Hillege, Hans L; van der Harst, Pim; van Gilst, Wiek H; Kop, Willem J; Gansevoort, Ron T; Vasan, Ramachandran S; Gardin, Julius M; Levy, Daniel; Gottdiener, John S; de Boer, Rudolf A; Larson, Martin G

    2016-01-01

    BACKGROUND: Heart failure (HF) is a prevalent and deadly disease, and preventive strategies focused on at-risk individuals are needed. Current HF prediction models have not examined HF subtypes. We sought to develop and validate risk prediction models for HF with preserved and reduced ejection fract

  4. Automatic detection of the optimal ejecting direction based on a discrete Gauss map

    Directory of Open Access Journals (Sweden)

    Masatomo Inui

    2014-01-01

    Full Text Available In this paper, the authors propose a system for assisting mold designers of plastic parts. With a CAD model of a part, the system automatically determines the optimal ejecting direction of the part with minimum undercuts. Since plastic parts are generally very thin, many rib features are placed on the inner side of the part to give sufficient structural strength. Our system extracts the rib features from the CAD model of the part, and determines the possible ejecting directions based on the geometric properties of the features. The system then selects the optimal direction with minimum undercuts. Possible ejecting directions are represented as discrete points on a Gauss map. Our new point distribution method for the Gauss map is based on the concept of the architectural geodesic dome. A hierarchical structure is also introduced in the point distribution, with a higher level “rough” Gauss map with rather sparse point distribution and another lower level “fine” Gauss map with much denser point distribution. A system is implemented and computational experiments are performed. Our system requires less than 10 seconds to determine the optimal ejecting direction of a CAD model with more than 1 million polygons.

  5. The classification of ambiguity in polarimetric reconstruction of coronal mass ejection

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Xinghua; Wang, Huaning; Huang, Xin; Du, Zhanle; He, Han, E-mail: xhdai@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2014-01-10

    The Thomson scattering theory indicates that there exist explicit and implicit ambiguities in polarimetric analyses of coronal mass ejection (CME) observations. We suggest a classification for these ambiguities in CME reconstruction. Three samples, including double explicit, mixed, and double implicit ambiguity, are shown with the polarimetric analyses of STEREO CME observations. These samples demonstrate that this classification is helpful for improving polarimetric reconstruction.

  6. Impaired left atrial function in heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    Santos, Angela B. S.; Kraigher-Krainer, Elisabeth; Gupta, Deepak K.; Claggett, Brian; Zile, Michael R.; Pieske, Burkert; Voors, Adriaan A.; Lefkowitz, Marty; Bransford, Toni; Shi, Victor; Packer, Milton; McMurray, John J. V.; Shah, Amil M.; Solomon, Scott D.

    2014-01-01

    AimsLeft atrial (LA) enlargement is present in the majority of heart failure with preserved ejection fraction (HFpEF) patients and is a marker of risk. However, the importance of LA function in HFpEF is less well understood. Methods and resultsThe PARAMOUNT trial enrolled HFpEF patients (LVEF 45%, N

  7. Heart Failure With Preserved Ejection Fraction and Atrial Fibrillation : Vicious Twins

    NARCIS (Netherlands)

    Kotecha, Dipak; Lam, Carolyn S. P.; Van Veldhuisen, Dirk J.; Van Gelder, Isabelle C.; Voors, Adriaan A.; Rienstra, Michiel

    2016-01-01

    Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are age-related conditions that are increasing in prevalence, commonly coexist, and share clinical features. This review provides a practical update on the epidemiology, pathophysiology, diagnosis, and management of

  8. Impaired Systolic Function by Strain Imaging in Heart Failure With Preserved Ejection Fraction

    NARCIS (Netherlands)

    Kraigher-Krainer, Elisabeth; Shah, Amil M.; Gupta, Deepak K.; Santos, Angela; Claggett, Brian; Pieske, Burkert; Zile, Michael R.; Voors, Adriaan A.; Lefkowitz, Marty P.; Packer, Milton; McMurray, John J. V.; Solomon, Scott D.

    2014-01-01

    Objectives This study sought to determine the frequency and magnitude of impaired systolic deformation in heart failure with preserved ejection fraction (HFpEF). Background Although diastolic dysfunction is widely considered a key pathophysiologic mediator of HFpEF, the prevalence of concomitant sys

  9. Predicting Heart Failure With Preserved and Reduced Ejection Fraction : The International Collaboration on Heart Failure Subtypes

    NARCIS (Netherlands)

    Ho, Jennifer E.; Enserro, Danielle; Brouwers, Frank P.; Kizer, Jorge R.; Shah, Sanjiv J.; Psaty, Bruce M.; Bartz, Traci M.; Santhanakrishnan, Rajalakshmi; Lee, Douglas S.; Chan, Cheeling; Liu, Kiang; Blaha, Michael J.; Hillege, Hans L.; van der Harst, Pim; van Gilst, Wiek H.; Kop, Willem J.; Gansevoort, Ron T.; Vasan, Ramachandran S.; Gardin, Julius M.; Levy, Daniel; Gottdiener, John S.; de Boer, Rudolf A.; Larson, Martin G.

    2016-01-01

    Background-Heart failure (HF) is a prevalent and deadly disease, and preventive strategies focused on at-risk individuals are needed. Current HF prediction models have not examined HF subtypes. We sought to develop and validate risk prediction models for HF with preserved and reduced ejection fracti

  10. Clinical validation of fully automated computation of ejection fraction from gated equilibrium blood-pool scintigrams

    NARCIS (Netherlands)

    J.H.C. Reiber (Johan); S.P. Lie; M.L. Simoons (Maarten); C. Hoek; J.J. Gerbrands (Jan); W. Wijns (William); W.H. Bakker (Willem); P.P.M. Kooij (Peter)

    1983-01-01

    textabstractA fully automated procedure for the computation of left-ventricular ejection fraction (EF) from cardiac-gated Tc-99m blood-pool (GBP) scintigrams with fixed, dual, and variable ROI methods is described. By comparison with EF data from contrast ventriculography in 68 patients, the dual-RO

  11. Ultrafast probing of ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets.

    Science.gov (United States)

    Bünermann, Oliver; Kornilov, Oleg; Haxton, Daniel J; Leone, Stephen R; Neumark, Daniel M; Gessner, Oliver

    2012-12-07

    The ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets are studied with time-resolved extreme ultraviolet ion imaging spectroscopy. At excitation energies of 23.6 ± 0.2 eV, Rydberg atoms in n = 3 and n = 4 states are ejected on different time scales and with significantly different kinetic energy distributions. Specifically, n = 3 Rydberg atoms are ejected with kinetic energies as high as 0.85 eV, but their appearance is delayed by approximately 200 fs. In contrast, n = 4 Rydberg atoms appear within the time resolution of the experiment with considerably lower kinetic energies. Major features in the Rydberg atom kinetic energy distributions for both principal quantum numbers can be described within a simple elastic scattering model of localized perturbed atomic Rydberg atoms that are expelled from the droplet due to their repulsive interaction with the surrounding helium bath. Time-dependent kinetic energy distributions of He(2) (+) and He(3) (+) ions are presented that support the formation of molecular ions in an indirect droplet ionization process and the ejection of neutral Rydberg dimers on a similar time scale as the n = 3 Rydberg atoms.

  12. Observation of two coronal mass ejections on April 7, 2011 by radio telescope URAN-2

    Science.gov (United States)

    Brazhenko, A.; Melnik, V.; Konovalenko, A.; Dorovskyy, V.; Vashchishin, V.; Franzusenko, A.; Rucker, H.

    2012-09-01

    Two CME's (coronal mass ejection) were registered by SOHO and STEREO on April 7, 2011. The results of observations obtained by radio telescope URAN-2 of different CME manifestations in radio emission at decameter wavelengths are discussed in this paper. Particularly we report about registration of new type of fine structure of type II bursts.

  13. Vanadate oligoanions interact with the proton ejection by the Ca2+ pump of sarcoplasmic reticulum.

    Science.gov (United States)

    Aureliano, M; Madeira, V M

    1994-11-30

    Decameric vanadate differs from other oligomeric vanadate species in inhibiting Ca2+ uptake and H+ ejection promoted by sarcoplasmic reticulum ATPase. A decavanadate solution, 2 mM in total vanadium, containing about 200 microM decameric species, inhibits by about 50% the uptake of Ca2+ and by 75% the H+ ejection, whereas 2 mM nominal monovanadate slightly increases the uptake of Ca2+ and inhibits the ejection of H+ by 25%. Moreover, decavanadate linearly increases the Ca2+/H+ ratio, whereas monovanadate mimicks decavanadate behavior only at concentrations up to 1.2 mM. For higher concentrations of monovanadate, this effect is reversed probably due to the formation of metavanadates, namely tetravandate. It is concluded that Ca2+ uptake is tightly coupled to proton ejection through molecular events that are sensitive to the interaction of vanadate species. Apparently, the stoichiometry is variable and modulated by molecular events involved in vanadate interaction suggesting alterations in the energetic coupling associated with Ca2+ translocation.

  14. Impact-driven ejection of micro metal droplets on-demand

    NARCIS (Netherlands)

    Luo, Jun; Qi, Lehua; Tao, Yuan; Ma, Qian; Visser, Claas Willem

    2016-01-01

    On-demand metal droplet deposition will be a cornerstone technology in 3D metal printing. However, suitable small nozzles are hardly available, limiting the resolution and surface finish of final products. Here, the ejection of record-small metal droplets with a diameter of only 0.55±0.07 times the

  15. Bi-temporal 3D active appearance models with applications to unsupervised ejection fraction estimation

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Pedersen, Dorthe

    2005-01-01

    Rapid and unsupervised quantitative analysis is of utmost importance to ensure clinical acceptance of many examinations using cardiac magnetic resonance imaging (MRI). We present a framework that aims at fulfilling these goals for the application of left ventricular ejection fraction estimation i...

  16. The relationship between mitral regurgitation and ejection fraction as predictors for the prognosis of patients with heart failure

    DEFF Research Database (Denmark)

    Thune, Jens Jakob; Torp-Pedersen, Christian; Hassager, Christian;

    2011-01-01

    To study whether there is interaction between mitral regurgitation (MR) and left ventricular ejection fraction (LVEF) in the mortality risk of heart failure (HF) patients.......To study whether there is interaction between mitral regurgitation (MR) and left ventricular ejection fraction (LVEF) in the mortality risk of heart failure (HF) patients....

  17. Study of the fluence dependent interplay between laser induced material removal mechanisms in metals: Vaporization, melt displacement and melt ejection

    Science.gov (United States)

    Fishburn, J. M.; Withford, M. J.; Coutts, D. W.; Piper, J. A.

    2006-05-01

    Three quantitative methods, namely profilometry, high speed imaging and recoil momentum measurements using a ballistic pendulum, are used to determine the interplay of vaporization, melt displacement and melt ejection on nanosecond laser induced material removal. At low to moderate fluences (7 J cm -2), material removal occurs predominantly via the explosive ejection of liquid droplets from the melt pool.

  18. Differing prognostic value of pulse pressure in patients with heart failure with reduced or preserved ejection fraction

    DEFF Research Database (Denmark)

    Jackson, Colette E.; Castagno, Davide; Maggioni, Aldo P.

    2015-01-01

    AIMS: Low pulse pressure is a marker of adverse outcome in patients with heart failure (HF) and reduced ejection fraction (HF-REF) but the prognostic value of pulse pressure in patients with HF and preserved ejection fraction (HF-PEF) is unknown. We examined the prognostic value of pulse pressure...

  19. Investigating pyroclast ejection dynamics using shock-tube experiments: temperature, grain size and vent geometry effects.

    Science.gov (United States)

    Cigala, V.; Kueppers, U.; Dingwell, D. B.

    2015-12-01

    Explosive volcanic eruptions eject large quantities of gas and particles into the atmosphere. The portion directly above the vent commonly shows characteristics of underexpanded jets. Understanding the factors that influence the initial pyroclast ejection dynamics is necessary in order to better assess the resulting near- and far-field hazards. Field observations are often insufficient for the characterization of volcanic explosions due to lack of safe access to such environments. Fortunately, their dynamics can be simulated in the laboratory where experiments are performed under controlled conditions. We ejected loose natural particles from a shock-tube while controlling temperature (25˚ and 500˚C), overpressure (15MPa), starting grain size distribution (1-2 mm, 0.5-1 mm and 0.125-0.250 mm), sample-to-vent distance and vent geometry. For each explosion we quantified the velocity of individual particles, the jet spreading angle and the production of fines. Further, we varied the setup to allow for different sample-to-gas ratios and deployed four different vent geometries: 1) cylindrical, 2) funnel with a flaring of 30˚, 3) funnel with a flaring of 15˚ and 4) nozzle. The results showed maximum particle velocities up to 296 m/s, gas spreading angles varying from 21˚ to 37˚ and particle spreading angles from 3˚ to 40˚. Moreover we observed dynamically evolving ejection characteristics and variations in the production of fines during the course of individual experiments. Our experiments mechanistically mimic the process of pyroclast ejection. Thus the capability for constraining the effects of input parameters (fragmentation conditions) and conduit/vent geometry on ballistic pyroclastic plumes has been clearly established. These data obtained in the presence of well-documented conduit and vent conditions, should greatly enhance our ability to numerically model explosive ejecta in nature.

  20. A Space Weather Information Service Based Upon Remote and In-Situ Measurements of Coronal Mass Ejections Heading for Earth

    CERN Document Server

    Ritter, Birgit; Miles, Oscar; Rußwurm, Michael; Scully, Stephen; Roldán, Andrés; Hartkorn, Oliver; Jüstel, Peter; Réville, Victor; Lupu, Sorina; Ruffenach, Alexis

    2015-01-01

    The Earth's magnetosphere is formed as a consequence of interaction between the planet's magnetic field and the solar wind, a continuous plasma stream from the Sun. A number of different solar wind phenomena have been studied over the past forty years with the intention of understanding and forecasting solar behavior. One of these phenomena in particular, Earth-bound interplanetary coronal mass ejections (CMEs), can significantly disturb the Earth's magnetosphere for a short time and cause geomagnetic storms. This publication presents a mission concept consisting of six spacecraft that are equally spaced in a heliocentric orbit at 0.72 AU. These spacecraft will monitor the plasma properties, the magnetic field's orientation and magnitude, and the 3D-propagation trajectory of CMEs heading for Earth. The primary objective of this mission is to increase space weather (SW) forecasting time by means of a near real-time information service, that is based upon in-situ and remote measurements of the aforementioned CM...

  1. Observational Tracking of the 2D Structure of Coronal Mass Ejections Between the Sun and 1 AU

    CERN Document Server

    Savani,; Davies,; A., J; Davis,; J., C; Shiota,; D.,; Rouillard,; P., A; Owens,; J., M; Kusano,; K.,; Bothmer,; V.,; Bamford,; P., S; Lintott,; J., C; Smith,; A,

    2015-01-01

    The Solar TErrestrial RElations Observatory (STEREO) provides high cadence and high resolution images of the structure and morphology of coronal mass ejections (CMEs) in the inner heliosphere. CME directions and propagation speeds have often been estimated through the use of time-elongation maps obtained from the STEREO Heliospheric Imager (HI) data. Many of these CMEs have been identified by citizen scientists working within the SolarStormWatch project ( www.solarstormwatch.com ) as they work towards providing robust real-time identification of Earth-directed CMEs. The wide field of view of HI allows scientists to directly observe the two-dimensional (2D) structures, while the relative simplicity of time-elongation analysis means that it can be easily applied to many such events, thereby enabling a much deeper understanding of how CMEs evolve between the Sun and the Earth. For events with certain orientations, both the rear and front edges of the CME can be monitored at varying heliocentric distances (R) bet...

  2. Multi-point shock and flux rope analysis of multiple interplanetary coronal mass ejections around 2010 August 1 in the inner heliosphere

    CERN Document Server

    Möstl, C; Kilpua, E K J; Jian, L K; Liu, Y; Eastwood, J; Harrison, R A; Webb, D F; Temmer, M; Odstrcil, D; Davies, J A; Rollett, T; Luhmann, J G; Nitta, N; Mulligan, T; Jensen, E A; Forsyth, R; Lavraud, B; De Koning, C A; Veronig, A M; Galvin, A B; Zhang, T L; Anderson, B J

    2012-01-01

    We present multi-point in situ observations of a complex sequence of coronal mass ejections (CMEs) which may serve as a benchmark event for numerical and empirical space weather prediction models. On 2010 August 1, instruments on various space missions (Solar Dynamics Observatory/ Solar and Heliospheric Observatory/Solar-TErrestrial-RElations-Observatory) monitored several CMEs originating within tens of degrees from solar disk center. We compare their imprints on four widely separated locations, spanning 120 degree in heliospheric longitude, with radial distances from the Sun ranging from MESSENGER (0.38 AU) to Venus Express (VEX, at 0.72 AU) to Wind, ACE and ARTEMIS near Earth, and STEREO-B close to 1 AU. Calculating shock and flux rope parameters at each location points to a non-spherical shape of the shock, and shows the global configuration of the interplanetary coronal mass ejections (ICMEs), which have interacted, but do not seem to have merged. VEX and STEREO-B observed similar magnetic flux ropes (MF...

  3. Vibration-induced drop atomization and the numerical simulation of low-frequency single-droplet ejection

    Science.gov (United States)

    James, Ashley J.; Smith, Marc K.; Glezer, Ari

    2003-02-01

    Vibration-induced droplet ejection is a novel way to create a spray. In this method, a liquid drop is placed on a vertically vibrating solid surface. The vibration leads to the formation of waves on the free surface. Secondary droplets break off from the wave crests when the forcing amplitude is above a critical value. When the forcing frequency is small, only low-order axisymmetric wave modes are excited, and a single secondary droplet is ejected from the tip of the primary drop. When the forcing frequency is high, many high-order non-axisymmetric modes are excited, the motion is chaotic, and numerous small secondary droplets are ejected simultaneously from across the surface of the primary drop. In both frequency regimes a crater may form that collapses to create a liquid spike from which droplet ejection occurs. An axisymmetric, incompressible, Navier Stokes solver was developed to simulate the low-frequency ejection process. A volume-of-fluid method was used to track the free surface, with surface tension incorporated using the continuum-surface-force method. A time sequence of the simulated interface shape compared favourably with an experimental sequence. The dynamics of the droplet ejection process was investigated, and the conditions under which ejection occurs and the effect of the system parameters on the process were determined.

  4. Redefining the boundaries of interplanetary coronal mass ejections from observations at the ecliptic plane

    CERN Document Server

    Cid, C; Saiz, E; Guerrero, A

    2016-01-01

    On 2015 January 6-7, an interplanetary coronal mass ejection (ICME) was observed at L1. This event, which can be associated with a weak and slow coronal mass ejection, allows us to discuss on the differences between the boundaries of the magnetic cloud and the compositional boundaries. A fast stream from a solar coronal hole surrounding this ICME offers a unique opportunity to check the boundaries' process definition and to explain differences between them. Using Wind and ACE data, we perform a complementary analysis involving compositional, magnetic, and kinematic observations providing relevant information regarding the evolution of the ICME as travelling away from the Sun. We propose erosion, at least at the front boundary of the ICME, as the main reason for the difference between the boundaries, and compositional signatures as the most precise diagnostic tool for the boundaries of ICMEs.

  5. Predicting the magnetic vectors within coronal mass ejections arriving at Earth

    CERN Document Server

    Savani, N P; Szabo, A; Mays, M L; Thompson, B J; Richardson, I G; Evans, R; Pulkkinen, A; Nieves-Chinchilla, T

    2015-01-01

    The process by which the Sun affects the terrestrial environment on short timescales is predominately driven by the amount of magnetic reconnection between the solar wind and Earth's magnetosphere. Reconnection occurs most efficiently when the solar wind magnetic field has a southward component. The most severe impacts are during the arrival of a coronal mass ejection (CME) when the magnetosphere is both compressed and magnetically connected to the heliospheric environment, leading to disruptions to, for example, power grids and satellite navigation. Unfortunately, forecasting magnetic vectors within coronal mass ejections remains elusive. Here we report how, by combining a statistically robust helicity rule for a CME's solar origin with a simplified flux rope topology the magnetic vectors within the Earth-directed segment of a CME can be predicted. In order to test the validity of this proof-of-concept architecture for estimating the magnetic vectors within CMEs, a total of eight CME events (between 2010 and...

  6. The fastest unbound star in our Galaxy ejected by a thermonuclear supernova

    CERN Document Server

    Geier, S; Ziegerer, E; Kupfer, T; Heber, U; Irrgang, A; Wang, B; Liu, Z; Han, Z; Sesar, B; Levitan, D; Kotak, R; Magnier, E; Smith, K; Burgett, W S; Chambers, K; Flewelling, H; Kaiser, N; Wainscoat, R; Waters, C

    2015-01-01

    Hypervelocity stars (HVS) travel with velocities so high, that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we present a spectroscopic and kinematic analysis of US\\,708. Travelling with a velocity of $\\sim1200\\,{\\rm km\\,s^{-1}}$, it is the fastest unbound star in our Galaxy. In reconstructing its trajectory, the Galactic center becomes very unlikely as an origin, which is hardly consistent with the most favored ejection mechanism for the other HVS. Furthermore, we discovered US\\,708 to be a fast rotator. According to our binary evolution model it was spun-up by tidal interaction in a close binary and is likely to be the ejected donor remnant of a thermonuclear supernova.

  7. Stellar dynamics. The fastest unbound star in our Galaxy ejected by a thermonuclear supernova.

    Science.gov (United States)

    Geier, S; Fürst, F; Ziegerer, E; Kupfer, T; Heber, U; Irrgang, A; Wang, B; Liu, Z; Han, Z; Sesar, B; Levitan, D; Kotak, R; Magnier, E; Smith, K; Burgett, W S; Chambers, K; Flewelling, H; Kaiser, N; Wainscoat, R; Waters, C

    2015-03-06

    Hypervelocity stars (HVSs) travel with velocities so high that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we present a spectroscopic and kinematic analysis of US 708. Traveling with a velocity of ~1200 kilometers per second, it is the fastest unbound star in our Galaxy. In reconstructing its trajectory, the Galactic center becomes very unlikely as an origin, which is hardly consistent with the most favored ejection mechanism for the other HVSs. Furthermore, we detected that US 708 is a fast rotator. According to our binary evolution model, it was spun-up by tidal interaction in a close binary and is likely to be the ejected donor remnant of a thermonuclear supernova.

  8. DNA heats up : Energetics of genome ejection from phage revealed by isothermal titration calorimetry

    CERN Document Server

    Jeembaeva, Meerim; Castelnovo, Martin; Evilevitch, Alex

    2010-01-01

    Most bacteriophages are known to inject their double-stranded DNA into bacteria upon receptor binding in an essentially spontaneous way. This downhill thermodynamic process from the intact virion toward the empty viral capsid plus released DNA is made possible by the energy stored during active packaging of the genome into the capsid. Only indirect measurements of this energy have been available until now using either single-molecule or osmotic suppression techniques. In this paper, we describe for the first time the use of isothermal titration calorimetry to directly measure the heat released (or equivalently the enthalpy) during DNA ejection from phage lambda, triggered in solution by a solubilized receptor. Quantitative analyses of the results lead to the identification of thermodynamic determinants associated with DNA ejection. The values obtained were found to be consistent with those previously predicted by analytical models and numerical simulations. Moreover, the results confirm the role of DNA hydrat...

  9. Simulation of a liquid droplet ejection device using multi-actuator

    Science.gov (United States)

    Ono, Yoshihiro; Yoshino, Michitaka; Yasuda, Akira; Tanuma, Chiaki

    2016-07-01

    An equivalent circuit model for a liquid droplet ejection device using a multiactuator has been developed. The equivalent circuit was simplified using a gyrator in the synthesis of the outputs of many elements. The simulation was performed for an inkjet head having three piezoelectric elements using MATLAB/Simulink. In this model, the pressure chamber is filled with a Newtonian fluid. For this reason, the model assumed only the resistance component of the pressure chamber and the nozzle as a load. Furthermore, since the resistance component of the inlet is much larger than that of the nozzle, it is not considered in this model. As a result, by providing a time difference between the driving signals of the piezoelectric elements, we found that the pressure of the ink chamber could be arbitrarily controlled. By this model, it becomes possible to control the pressure in the ink chamber of the inkjet head required for the ejection of various inks.

  10. Sensing Technique Using Laser-induced Breakdown Spectroscopy Integrated with Micro-droplet Ejection System

    Directory of Open Access Journals (Sweden)

    Satoshi Ikezawa

    2008-04-01

    Full Text Available In this paper, laser-induced breakdown spectroscopy (LIBS using micro-droplet NaCl solution is described. Since the 1980s, many liquid micronizing techniques for LIBS measurements have been reported. In this study, micro-droplet ejection systems for sampling are designed and presented for two volumes. These micro-droplet ejection systems enable a constant volume of the sample liquid to be obtained and they take advantage of the liquid physical state; the density of the solution can be controlled accurately. The methods presented here generate small droplets (diameter 30 or 50 μm by confining the entire volume of the sample material in the laser beam spot area (minimum beam spot diameter: 53.2 μm and separating it from its surroundings. Using these liquid micronizing methods, improved sensitivities are obtained for drawing calibration curves for quantitative LIBS measurements.

  11. Understanding the Global Structure and Evolution of Coronal Mass Ejections in the Solar Wind

    Science.gov (United States)

    Riley, Pete

    2004-01-01

    This report summarizes the technical progress made during the first six months of the second year of the NASA Living with a Star program contract Understanding the global structure and evolution of coronal mass ejections in the solar wind, between NASA and Science Applications International Corporation, and covers the period November 18, 2003 - May 17,2004. Under this contract SAIC has conducted numerical and data analysis related to fundamental issues concerning the origin, intrinsic properties, global structure, and evolution of coronal mass ejections in the solar wind. During this working period we have focused on a quantitative assessment of 5 flux rope fitting techniques. In the following sections we summarize the main aspects of this work and our proposed investigation plan for the next reporting period. Thus far, our investigation has resulted in 6 refereed scientific publications and we have presented the results at a number of scientific meetings and workshops.

  12. A Basic Study on the Ejection of ICI Nozzle under Severe Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jong Rae; Bae, Ji Hoon; Bang, Kwang Hyun [Korea Maritime and Ocean University, Busan (Korea, Republic of); Park, Jong Woong [Dongguk University, Gyeongju (Korea, Republic of)

    2016-05-15

    Nozzle injection should be blocked because it affect to the environment if its melting core exposes outside. The purpose of this study is to carry out the thermos mechanical analysis due to debris relocation under severe accidents and to predict the nozzle ejection calculated considering the contact between the nozzle and lower head, and the supports of pipe cables. As a result of analyzing process of severe accidents, there was melting reaction between nozzle and the lower head. In this situation, we might predict the non-uniform contact region of nozzle hole of lower head and nozzle outside, delaying ejection of nozzles. But after melting, the average remaining length of the nozzle was 120mm and the maximum vertical displacement of lower nozzle near the weld is 3.3mm so there would be no nozzle this model, because the cable supports restrains the vertical displacement of nozzle.

  13. Heart Failure in Patients with Preserved Ejection Fraction: Questions Concerning Clinical Progression

    Directory of Open Access Journals (Sweden)

    George E. Louridas

    2016-09-01

    Full Text Available Over the last two decades, important advances have been made in explaining some pathophysiological aspects of heart failure with preserved ejection fraction (HFpEF with repercussions for the successful clinical management of the syndrome. Despite these gains, our knowledge for the natural history of clinical progression from the pre-clinical diastolic dysfunction (PDD until the final clinical stages is significantly limited. The subclinical progression of PDD to the clinical phenotype of HFpEF and the further clinical progression to some more complex clinical models with multi-organ involvement, similar to heart failure with reduced ejection fraction (HFrEF, continue to be poorly understood. Prospective studies are needed to elucidate the natural history of clinical progression in patients with HFpEF and to identify the exact left ventricular remodeling mechanism that underlies this progression.

  14. [What is new in heart failure with preserved ejection fraction within last five years?].

    Science.gov (United States)

    Gregorová, Zdeňka; Meluzín, Jaroslav; Spinarová, Lenka

    2014-01-01

    Heart failure with preserved ejection fraction of left ventricle (heart failure with normal ejection fraction, HFPEF, HFNEF) is frequent disease with serious consequences. Incidence of HFPEF in population is still growing. The exact pathophysiological mechanism of HFPEF remain unclear .Recent evidence suggests a relationship between inflammation associated with obesity or Diabetes mellitus and progression of HFPEF. Consistently, it has been reported that serum concentration of some pro-inflammatory markers such as adiponectin is positively related to HFPEF. By HFPEF is attended diastolic dysfunction. Diastolic dysfunction is linked to many other cardiac and non-cardiac diseases. Despite the great effort and new therapeutic approaches the prognosis of HFPEF does not improve. The gold standard in HFPEF diagnosis remains heart catheterization. Electrocardiography, chest X-ray, blood examination including diagnostic markers of heart failure and mainly echocardiography with Doppler imaging are used diagnose the underlying disease leading to heart failure.

  15. Fireball ejection from a molten hot spot to air by localized microwaves.

    Science.gov (United States)

    Dikhtyar, Vladimir; Jerby, Eli

    2006-02-03

    A phenomenon of fireball ejection from hot spots in solid materials (silicon, germanium, glass, ceramics, basalt, etc.) to the atmosphere is presented. The hot spot is created in the substrate material by the microwave-drill mechanism [Jerby, Science 298, 587 (2002)10.1126/science.1077062]. The vaporized drop evolved from the hot spot is blown up, and forms a stable fireball buoyant in the air. The experimental observations of fireball ejection from silicate hot spots are referred to the Abrahamson-Dinniss theory [Nature (London) 403, 519 (2000)10.1038/35000525] suggesting a mechanism for ball-lightning initiation in nature. The fireballs observed in our experiments tend to absorb the available microwave power entirely, similarly to the plasmon resonance effect in submicron wavelengths [Nie and Emory, Science 275, 1102 (1997)10.1126/science.275.5303.1102].

  16. IMPROVING EFFICIENCY OF THE JET PUMP AT LOW COEFFICIENTS OF EJECTION

    Directory of Open Access Journals (Sweden)

    A. G. Butenko

    2015-01-01

    Full Text Available Jet pumps are widely used in the power industry as well as in many others. Their main disadvantage is low operating efficiency which aggravates when the jet pump is working with a low ejection coefficient. Such modes are sometimes unavoidable being conditioned by the character of technological process. The article considers methods of improving the operation of central ejectors at small ejection coefficients.The authors use mathematical simulation approach to study the particularities of kinematic structure of the flow in the mixing chamber of the central ejector operating with low ejection coefficients. They utilize Solid Works Cosmos Flo application-program package for the mathematical simulation. The study shows that areas of reverse flows appear alongside the walls of the mixing chamber under the above conditions which reduces the efficiency of the jet apparatus. The more is the extent of the discovered areas the more is the loss of energy. The study detects the regime zones where detached flows areas appear. The authors propose to replace such areas with solid surface (substitution bodies for preventing them from emerging. The  mathematical  simulation  results  determine  the  geometric  parameters  of the  substitution bodies for the central ejectors with different modules and ejection coefficients and yield mathematical description of their shape. Mathematical and physical simulation of the centralejector operation with the substitution bodies shows the increase in pressure-head and efficiency coefficients in such apparatuses as compared to ejectors of the conventional form. Efficiency increase is the case in quite a wide range of operating modes.The proposed method of the efficiency increase for the central ejectors is rather straightforward and does not require substantial financial expenditures for its implementation.

  17. DNA ejection from bacteriophage: towards a general behavior for osmotic suppression experiments

    CERN Document Server

    Castelnovo, Martin

    2007-01-01

    We present in this work in vitro measurements of the force ejecting DNA from two distinct bacteriophages (T5 and lambda) using the smotic-suppression technique. Our data are analyzed by revisiting the current theories of DNA packaging in spherical capsids. In particular we show that a simplified analytical model based on bending considerations only is able to account quantitatively for the experimental findings. Physical and biological consequences are discussed.

  18. Analysing the effects of rigid and flexible aircraft dynamics on the ejection of a large store

    CSIR Research Space (South Africa)

    Jamison, Kevin

    2011-09-01

    Full Text Available Aeronautical Systems Competency Defence, Peace, Safety and Security (DPSS) ANALYSING THE EFFECTS OF RIGID AND FLEXIBLE AIRCRAFT DYNAMICS ON THE EJECTION OF A LARGE STORE International Aerospace Symposium of South Africa 26 ? 28... & rigid aircraft dynamics on store release ? Closing the loop ? comparison with flight tests ? Conclusions ? CSIR 2011 Slide 3 Background to Hawk / Katleho project ? CSIR 2011 Slide 4 ? Katleho is a PGM under development by Denel Dynamics...

  19. Low Frequency (30-110 MHz) Radio Imaging Observations Of Solar Coronal Mass Ejections

    Science.gov (United States)

    Ramesh, R.

    Ground based radio imaging observations play an useful role in the study of mass ejections from the solar corona since they do not have the limitation of an occulter and both the disk/limb events can be detected early in their development, particularly via the thermal bremmstrahlung emission from the frontal loop of the CME. I present here some of the recent results on the above topic using data obtained with the Gauribidanur radioheliograph, near Bangalore in India.

  20. Cartridge Casing Catcher With Reduced Firearm Ejection Port Flash and Noise

    Science.gov (United States)

    2009-05-26

    respective deflectors. The magnetic material is generally at least one of steel, Strontium and Barium ferrite , Samarium- Cobalt , Neody- mium -Iron...Boron, and Aluminum-Nickel- Cobalt alloy. Accordingly, the present invention may provide a cartridge casing catcher with reduced firearm ejection port...a Strontium and Barium ferrite , Samarium-Co- balt, Neodymium-Iron-Boron, other pennanently magnetic rare earth alloys, and Alnico (i.e., Aluminum

  1. Real-time Analysis of Global Waves Accompanying Coronal Mass Ejections

    Science.gov (United States)

    2016-09-01

    Ejections FA9550-14-1-0213 Long, David M., Rae , I. Jonathan, Pérez-Suárez, D. University College London (UCL) Gower Street London WC1 E6BT European...significant portion of the Sun in under an hour. However, their origin and relationship to CMEs remains a mystery due to the manual techniques...1-0213 Principle Investigator; David M. Long Period of Performance; 1 October 2014 – 30 June 2016 Additional Staff; Jonathan Rae (Co–Investigator

  2. Evaluation of Aircraft Ejection Seat Safety When Using Advanced Helmet Sensors

    Science.gov (United States)

    2015-03-09

    survivability and equipment airworthiness requirements for pilots and aircrew wearing helmet-mounted displays (HMDs), night vision goggles (NVGs), or both...equipment airworthiness requirements for pilots and aircrew wearing helmet-mounted displays (HMDs), night vision goggles (NVGs), or both during ejection...and equipment airworthiness requirements for pilots and aircrew wearing helmet-mounted displays (HMDs), night vision goggles (NVGs), or both during

  3. Renal dysfunction and anemia in patients with heart failure with reduced versus normal ejection fraction.

    Science.gov (United States)

    Villacorta, Humberto; Saenz-Tello, Bolivar F; Santos, Eduarda Barcellos dos; Steffen, Ricardo; Wiefels, Christiane; Lima, Luiz Costa; Sales, Ana Luíza F; Soares, Pedro; Mesquita, Evandro Tinoco

    2010-03-01

    The presence of anemia and renal dysfunction grants a bad prognosis for patients with heart failure and reduced ejection fraction (HFREF). The impact on patients with heart failure and normal ejection fraction (HFNEF) is not widely studied. To study the prevalence and the prognosis of anemia and renal dysfunction (RD) in patients with heart failure according to the type of ventricular dysfunction. A total of 209 patients with chronic and stable heart failure were prospectively studied. Individuals with ejection fraction Anemia was defined, based on WHO criteria, as hemoglobin Renal function was calculated by means of the Simplified Modified Diet Renal Disease (sMDRD) formula. Hospitalizations, emergency admittances and obit by cardiac causes were considered as cardiac events. Ninety patients had HFREF and 119 had HFNEF. The glomerular filtration rate (GFR) was smaller in HFREF group (57.6 +/- 66.2 versus 94.8 +/- 36.6 ml/min/1.73m(2); p=0.01). There was no difference in the prevalence of anemia between groups (23.3% versus 18.5%; p=0.34). Moderate to severe RD prevalence was higher in HFREF group (32.2% versus 16.8%; p=0.01). RD was the only factor associated with anemia that was independently associated with cardiac events (HR 2.52; 95%CI=1.27-5.2; p=0.01). RD was less prevalent in HFNEF, while the prevalence of anemia did not differ between groups. RD was predictor of cardiac events independently on ejection fraction.

  4. Direct observations of magnetic flux rope formation during a solar coronal mass ejection

    OpenAIRE

    Song, Hongqiang; Zhang, Jie; Chen, Yao; Cheng, Xin

    2014-01-01

    Coronal mass ejections (CMEs) are the most spectacular eruptive phenomena in the solar atmosphere. It is generally accepted that CMEs are results of eruptions of magnetic flux ropes (MFRs). However, a heated debate is on whether MFRs pre-exist before the eruptions or they are formed during the eruptions. Several coronal signatures, \\textit{e.g.}, filaments, coronal cavities, sigmoid structures and hot channels (or hot blobs), are proposed as MFRs and observed before the eruption, which suppor...

  5. Real-Time Analysis of Global Waves Accompanying Coronal Mass Ejections

    Science.gov (United States)

    2016-06-30

    tions and modelling to conclude that a solar eruption must have sufficient energy and downward pressure on the chromosphere before it can produce a...intensity of the wave relative to the background chromosphere. Upon completion of the code, it was applied to a series of solar flares observed by both...wave-like features seen in H observations of the solar chromosphere. They are strongly associated with coronal mass ejections (CMEs) and can cover a

  6. Certain issues about unexpected ejection of gas and life saving operations

    Energy Technology Data Exchange (ETDEWEB)

    Kristian, B.; Szazados, I.

    1984-01-01

    Prerequisites for sudden ejections of methane are examined, along with measures to prevent its spread along mine drifts in the coal mines of Hungary (VNR). Light is shed on the problems of saving people who end up in dangerous zones and for organizing operations to prepare and train miners in life saving operations. Experience in the organization of such operations in the mines of the Mechek coal basin showed their practical expedience.

  7. Ejection of molecules from solid deuterium excited by keV electrons

    DEFF Research Database (Denmark)

    Pedrys, R.; Warczak, B.; Schou, Jørgen

    1997-01-01

    The energy distribution of sputtered D-2 from electron-bombarded solid deuterium has been studied for the first time. The spectra from this quantum solid show features that may originate from an energy release sequence of association of atoms. For ejection energies above 1 meV the gross features...... of the spectrum are similar to those from electronic sputtering of ether much less volatile condensed gases. Sputtered D-4 molecules have been observed for the first time as well....

  8. A Unified Bond Graph Modeling Approach for the Ejection Phase of the Cardiovascular System

    OpenAIRE

    LUBNA MOIN; VALI UDDIN

    2016-01-01

    In this paper the unified Bond Graph model of the left ventricle ejection phase is presented, simulated and validated. The integro-differential and ordinary differential equations obtained from the bond graph models are simulated using ODE45 (Ordinary Differential Equation Solver) on MATLAB and Simulink. The results, thus, obtained are compared with CVS (Cardiovascular System) physiological data present in Simbiosys (a software for simulating biological systems) and also with the CVS Wigge...

  9. An ejection model for SNC meteorites: An indication for recent volcanism on Mars

    Science.gov (United States)

    Manker, J. P.

    1992-01-01

    When compared to other achondrites, Shergotty-Nakhla-Chassigny (SNC) meteorites are viewed as anomalous objects. This conclusion is based mainly on their extremely young crystallization ages and their short cosmic ray exposure times. Further, SNC's noble gas and nitrogen components indicate a martian origin for these objects. If these meteorites are from Mars, then the most confounding question facing the planetary science community is how were they ejected from the planet's surface. The following is an investigation of that question.

  10. Enhancement of weld failure and tube ejection model in PENTAP program

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jaehoon; An, Sang Mo; Ha, Kwang Soon; Kim, Hwan Yeol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The reactor vessel pressure, the debris mass, the debris temperature, and the component of material can have an effect on the penetration tube failure modes. Furthermore, these parameters are interrelated. There are some representative severe accident codes such as MELCOR, MAAP, and PENTAP program. MELCOR decides on a penetration tube failure by its failure temperature such as 1273K simply. MAAP considers all penetration failure modes and has the most advanced model for a penetration tube failure model. However, the validation work against the experimental data is very limited. PENTAP program which evaluates the possible penetration tube failure modes such as creep failure, weld failure, tube ejection, and a long term tube failure under given accident condition was developed by KAERI. The experiment for the tube ejection is being performed by KAERI. The temperature distribution and the ablation rate of both weld and lower vessel wall can be obtained through the experiment. This paper includes the updated calculation steps for the weld failure and the tube ejection modes of the PENTAP program to apply the experimental results. PENTAP program can evaluate the possible penetration tube failure modes. It still requires a large amount of efforts to increase the prediction of failure modes. Some calculation steps are necessary for applying the experimental and the numerical data in the PENTAP program. In this study, new calculation steps are added to PENTAP program to enhance the weld failure and tube ejection models using KAERI's experimental data which are the ablation rate and temperature distribution of weld and lower vessel wall.

  11. R-Process Nucleosynthesis in Dynamically Ejected Matter of Neutron Star Mergers

    CERN Document Server

    Goriely, Stephane; Janka, H -Thomas

    2011-01-01

    Although the rapid neutron-capture process, or r-process, is fundamentally important for explaining the origin of approximately half of the stable nuclei with A > 60, the astrophysical site of this process has not been identified yet. Here we study r-process nucleosynthesis in material that is dynamically ejected by tidal and pressure forces during the merging of binary neutron stars (NSs) and within milliseconds afterwards. For the first time we make use of relativistic hydrodynamical simulations of such events, defining consistently the conditions that determine the nucleosynthesis, i.e., neutron enrichment, entropy, early density evolution and thus expansion timescale, and ejecta mass. We find that 10^{-3}-10^{-2} solar masses are ejected, which is enough for mergers to be the main source of heavy (A > 140) galactic r-nuclei for merger rates of some 10^{-5} per year. While asymmetric mergers eject 2-3 times more mass than symmetric ones, the exact amount depends weakly on whether the NSs have radii of ~15 ...

  12. Systematics of dynamical mass ejection, nucleosynthesis, and radioactively powered electromagnetic signals from neutron-star mergers

    CERN Document Server

    Bauswein, A; Janka, H -T

    2013-01-01

    Neutron star (NS) mergers can eject considerable amounts of neutron-rich matter, allowing for r-processing. The radioactive decay of the products heats the ejecta and makes them potentially observable as a source of thermal electromagnetic radiation. We investigate systematically the dynamical mass ejection during the NS collision in dependence on uncertain properties of the nuclear equation of state (EoS) by using 40 representative, microphysical EoSs in relativistic merger simulations. The NS compactness, characterized by the radius R_1.35 of nonrotating NSs of 1.35 Msun, is the crucial parameter that determines the ejecta mass. NSs with smaller radii R_1.35 ("soft"' EoS) collide more violently and eject systematically higher masses. These range from ~10^-3 Msun to ~10^-2 Msun for symmetric 1.35-1.35 Msun binaries with R_1.35 between 16 km and 11 km, and from ~5*10^-3 Msun to ~2*10^-2 Msun for asymmetric 1.2-1.5 Msun binaries. Correspondingly, the bolometric peak luminosities of the optical transients vary ...

  13. Genesis Solar Wind Interstream, Coronal Hole and Coronal Mass Ejection Samples: Update on Availability and Condition

    Science.gov (United States)

    Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

    2017-01-01

    Recent refinement of analysis of ACE/SWICS data (Advanced Composition Explorer/Solar Wind Ion Composition Spectrometer) and of onboard data for Genesis Discovery Mission of 3 regimes of solar wind at Earth-Sun L1 make it an appropriate time to update the availability and condition of Genesis samples specifically collected in these three regimes and currently curated at Johnson Space Center. ACE/SWICS spacecraft data indicate that solar wind flow types emanating from the interstream regions, from coronal holes and from coronal mass ejections are elementally and isotopically fractionated in different ways from the solar photosphere, and that correction of solar wind values to photosphere values is non-trivial. Returned Genesis solar wind samples captured very different kinds of information about these three regimes than spacecraft data. Samples were collected from 11/30/2001 to 4/1/2004 on the declining phase of solar cycle 23. Meshik, et al is an example of precision attainable. Earlier high precision laboratory analyses of noble gases collected in the interstream, coronal hole and coronal mass ejection regimes speak to degree of fractionation in solar wind formation and models that laboratory data support. The current availability and condition of samples captured on collector plates during interstream slow solar wind, coronal hole high speed solar wind and coronal mass ejections are de-scribed here for potential users of these samples.

  14. Left ventricular ejection time, not heart rate, is an independent correlate of aortic pulse wave velocity.

    Science.gov (United States)

    Salvi, Paolo; Palombo, Carlo; Salvi, Giovanni Matteo; Labat, Carlos; Parati, Gianfranco; Benetos, Athanase

    2013-12-01

    Several studies showed a positive association between heart rate and pulse wave velocity, a sensitive marker of arterial stiffness. However, no study involving a large population has specifically addressed the dependence of pulse wave velocity on different components of the cardiac cycle. The aim of this study was to explore in subjects of different age the link between pulse wave velocity with heart period (the reciprocal of heart rate) and the temporal components of the cardiac cycle such as left ventricular ejection time and diastolic time. Carotid-femoral pulse wave velocity was assessed in 3,020 untreated subjects (1,107 men). Heart period, left ventricular ejection time, diastolic time, and early-systolic dP/dt were determined by carotid pulse wave analysis with high-fidelity applanation tonometry. An inverse association was found between pulse wave velocity and left ventricular ejection time at all ages (pulse wave velocity and heart period was also found, with the exception of the youngest subjects (P = 0.20). A significant positive correlation was also found between pulse wave velocity and dP/dt (P pulse wave velocity at all ages, whereas the contribution of heart period no longer became significant. Our data demonstrate that pulse wave velocity is more closely related to left ventricular systolic function than to heart period. This may have methodological and pathophysiological implications.

  15. Exploring the limits of spin transport efficiency for spin ejection in spin photodiodes

    Science.gov (United States)

    Simon, K. P.; Belkadi, A.; Isakovic, A. F.

    2012-02-01

    We examine several factors that affect the efficiency of the transport of optically excited, spin-polarized carriers in ferromagnet-semiconductor heterostructures. The process of optical excitation leads to the creation of the population of spin carriers in a III-V semiconductor [1], which faces a number of obstacles on its way out of the semiconductor. This poster addresses a hierarchy of problems that need to be addressed in order to improve the efficiency of spin ejection, with the goal of bringing it up to the efficiency level of the opposite process, the spin injection. Our approach is based on modeling the existing spin ejection data, in order to understand several spin relaxation processes and the transport across the interface between a semiconductor and a ferromagnet or other metal. Our results are based in part on Schokley-Queisser [2] approach for photodiodes efficiency. Our investigation shows that there is a considerable space for improvement of spin ejection transport efficiency, which opens up possibility of designing novel spintronics devices. [4pt] [1] A. F. Isakovic, D. M. Carr, J. Strand, et al., Phys. Rev. B 64 161304.[0pt] [2] W. Schokley, H. J. Queisser, J. Appl. Phys. 32 (3), 510.

  16. Filaments disappearance in relation to coronal mass ejections during the solar cycle 23

    Science.gov (United States)

    Mawad, R.; Shaltout, Mosalam; Yousef, M.; Yousef, S.; Ewaida, M.

    2015-01-01

    We have studied the relationship between filament disappearances with CMEs during solar period 1996-2010. We used the observed disappearing filaments in Hα data from Meudon given in NOAA, and coronal mass ejections data (CMEs) from SOHO/LASCO. We obtained 278 CME events (14%) contemporary filament disappearances and CME ejections (from a total of 2018 filament disappearance events and 15,874 CME events during 1996-2010). We found that the number of associated CME-filament disappearance events increased with the increase of the solar activity and significantly decreased with quiet sun. The longer filament disappearances have activity and ability to contemporary association with CMEs more than shorter filament disappearances. The filament disappearance powers the associated CMEs. CMEs which are associated with filament disappearance are ejected with higher speeds, massive, more energetic, and smaller angular width compared to non-associated CME events. In addition, the associated filament disappearance CMEs have two types depending on their duration; short-lived (9 h).

  17. Reducing Space Charge Effects in a Linear Ion Trap by Rhombic Ion Excitation and Ejection

    Science.gov (United States)

    Zhang, Xiaohua; Wang, Yuzhuo; Hu, Lili; Guo, Dan; Fang, Xiang; Zhou, Mingfei; Xu, Wei

    2016-07-01

    Space charge effects play important roles in ion trap operations, which typically limit the ion trapping capacity, dynamic range, mass accuracy, and resolving power of a quadrupole ion trap. In this study, a rhombic ion excitation and ejection method was proposed to minimize space charge effects in a linear ion trap. Instead of applying a single dipolar AC excitation signal, two dipolar AC excitation signals with the same frequency and amplitude but 90° phase difference were applied in the x- and y-directions of the linear ion trap, respectively. As a result, mass selective excited ions would circle around the ion cloud located at the center of the ion trap, rather than go through the ion cloud. In this work, excited ions were then axially ejected and detected, but this rhombic ion excitation method could also be applied to linear ion traps with ion radial ejection capabilities. Experiments show that space charge induced mass resolution degradation and mass shift could be alleviated with this method. For the experimental conditions in this work, space charge induced mass shift could be decreased by ~50%, and the mass resolving power could be improved by ~2 times at the same time.

  18. Ground experimental investigations into an ejected spray cooling system for space closed-loop application

    Directory of Open Access Journals (Sweden)

    Zhang Hongsheng

    2016-06-01

    Full Text Available Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor–liquid mixture from the heat surface and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space environments. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and experimental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 °C and 78.2 °C under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11.22 L/h to 15.76 L/h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed; results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.

  19. Ground experimental investigations into an ejected spray cooling system for space closed-loop application

    Institute of Scientific and Technical Information of China (English)

    Zhang Hongsheng; Li Yunze; Wang Shengnan; Liu Yang; Zhong Mingliang

    2016-01-01

    Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor–liquid mixture from the heat sur-face and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space environments. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and exper-imental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 ?C and 78.2 ?C under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11.22 L/h to 15.76 L/h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed;results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.

  20. Propagation of capillary waves and ejection of small droplets in rapid droplet spreading

    KAUST Repository

    Ding, Hang

    2012-03-12

    A new regime of droplet ejection following the slow deposition of drops onto a near-complete wetting solid substrate is identified in experiments and direct numerical simulations; a coalescence cascade subsequent to pinch-off is also observed for the first time. Results of numerical simulations indicate that the propagation of capillary waves that lead to pinch-off is closely related to the self-similar behaviour observed in the inviscid recoil of droplets, and that motions of the crests and troughs of capillary waves along the interface do not depend on the wettability and surface tension (or Ohnesorge number). The simulations also show that a self-similar theory for universal pinch-off can be used for the time evolution of the pinching neck. However, although good agreement is also found with the double-cone shape of the pinching neck for droplet ejection in drop deposition on a pool of the same liquid, substantial deviations are observed in such a comparison for droplet ejection in rapid drop spreading (including the newly identified regime). This deviation is shown to result from interference by the solid substrate, a rapid downwards acceleration of the top of the drop surface and the rapid spreading process. The experiments also confirm non-monotonic spreading behaviour observed previously only in numerical simulations, and suggest substantial inertial effects on the relation between an apparent contact angle and the dimensionless contact-line speed. © 2012 Cambridge University Press.

  1. Pre-ejection period by radial artery tonometry supplements echo doppler findings during biventricular pacemaker optimization

    Directory of Open Access Journals (Sweden)

    Qamruddin Salima

    2011-07-01

    Full Text Available Abstract Background Biventricular (Biv pacemaker echo optimization has been shown to improve cardiac output however is not routinely used due to its complexity. We investigated the role of a simple method involving computerized pre-ejection time (PEP assessment by radial artery tonometry in guiding Biv pacemaker optimization. Methods Blinded echo and radial artery tonometry were performed simultaneously in 37 patients, age 69.1 ± 12.8 years, left ventricular (LV ejection fraction (EF 33 ± 10%, during Biv pacemaker optimization. Effect of optimization on echo derived velocity time integral (VTI, ejection time (ET, myocardial performance index (MPI, radial artery tonometry derived PEP and echo-radial artery tonometry derived PEP/VTI and PEP/ET indices was evaluated. Results Significant improvement post optimization was achieved in LV ET (286.9 ± 37.3 to 299 ± 34.6 ms, p Conclusion An acute shortening of PEP by radial artery tonometry occurs post Biv pacemaker optimization and correlates with improvement in hemodynamics by echo Doppler and may provide a cost-efficient approach to assist with Biv pacemaker echo optimization.

  2. Sensitivity studies for 3-D rod ejection analyses on axial power shape

    Energy Technology Data Exchange (ETDEWEB)

    Park, Min-Ho; Park, Jin-Woo; Park, Guen-Tae; Ryu, Seok-Hee; Um, Kil-Sup; Lee, Jae-Il [KEPCO NF, Daejeon (Korea, Republic of)

    2015-10-15

    The current safety analysis methodology using the point kinetics model combined with numerous conservative assumptions result in unrealistic prediction of the transient behavior wasting huge margin for safety analyses while the safety regulation criteria for the reactivity initiated accident are going strict. To deal with this, KNF is developing a 3-D rod ejection analysis methodology using the multi-dimensional code coupling system CHASER. The CHASER system couples three-dimensional core neutron kinetics code ASTRA, sub-channel analysis code THALES, and fuel performance analysis code FROST using message passing interface (MPI). A sensitivity study for 3-D rod ejection analysis on axial power shape (APS) is carried out to survey the tendency of safety parameters by power distributions and to build up a realistic safety analysis methodology while maintaining conservatism. The currently developing 3-D rod ejection analysis methodology using the multi-dimensional core transient analysis code system, CHASER was shown to reasonably reflect the conservative assumptions by tuning up kinetic parameters.

  3. The Explosive Ejection of Small Droplets From a Liquid-Gas Interface.

    Science.gov (United States)

    James, Ashley; Smith, Marc K.; Glezer, Ari

    1996-11-01

    Vibration-induced liquid atomization is a process that occurs when a liquid droplet is placed on a vibrating membrane. When the proper operating conditions are attained, the droplet resonates with the motion of the membrane and explosively bursts into a spray of very small droplets. The process occurs through an instability of the surface wave motion on the free surface of the large droplet set up by the vibration of the underlying surface. We present experimental data on this process that shows how the droplet ejection event depends on the frequency and amplitude of the vibrating surface and on the initial volume of the large liquid droplet. Video images are also presented that show the basic process and some interesting transient behaviors leading to the ejection event. Our current and future experimental and analytical work on this process is directed towards an understanding of the mechanism behind the atomization process, a full characterization of the free surface instability leading to the droplet ejection event, and a knowledge of the size and velocity distributions in the resulting spray. In addition, vibration-induced droplet atomization is the basis of a new design for an evaporative heat transfer cell that is currently under development for micro-gravity applications. Supported by NASA and Georgia Tech.

  4. Mass ejection by pulsational pair-instability in very massive stars and implications for luminous supernovae

    CERN Document Server

    Yoshida, Takashi; Maeda, Keiichi; Ishii, Tatsuo

    2015-01-01

    Massive stars having a CO core of $\\sim 40 - 60$ M$_\\odot$ experience pulsational pair-instability (PPI) after carbon-burning. This instability induces strong pulsations of the whole star and a part of outer envelope is ejected. We investigate the evolution and mass ejection of metal-poor very massive stars which experience PPI. We use stellar models with initial masses of 140, 200, and 250 M$_\\odot$ and the metallicity Z=0.004. Their masses decrease to 54.09, 58.65, and 61.03 M$_\\odot$ before the neon-burning owing to mass loss and He mass fraction at the surface becomes about 20%. During the PPI period of $\\sim 1 - 2000$ years, they experience six, four, and three pulsations, respectively. The larger CO-core model has the longer PPI period and ejects the larger amount of mass. Since almost all surface He has been lost by the pulsations, these stars become type Ic supernovae if they explode. Light curves during the PPI stage and supernovae are investigated and are implicated in luminous supernovae. The lumin...

  5. IS SOLAR CYCLE 24 PRODUCING MORE CORONAL MASS EJECTIONS THAN CYCLE 23?

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.-M.; Colaninno, R., E-mail: yi.wang@nrl.navy.mil, E-mail: robin.colaninno@nrl.navy.mil [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-04-01

    Although sunspot numbers are roughly a factor of two lower in the current cycle than in cycle 23, the rate of coronal mass ejections (CMEs) appears to be at least as high in 2011-2013 as during the corresponding phase of the previous cycle, according to three catalogs that list events observed with the Large Angle and Spectrometric Coronagraph (LASCO). However, the number of CMEs detected is sensitive to such factors as the image cadence and the tendency (especially by human observers) to under-/overcount small or faint ejections during periods of high/low activity. In contrast to the total number, the total mass of CMEs is determined mainly by larger events. Using the mass measurements of 11,000 CMEs given in the manual CDAW catalog, we find that the mass loss rate remains well correlated with the sunspot number during cycle 24. In the case of the automated CACTus and SEEDS catalogs, the large increase in the number of CMEs during cycle 24 is almost certainly an artifact caused by the near-doubling of the LASCO image cadence after mid-2010. We confirm that fast CMEs undergo a much stronger solar-cycle variation than slow ones, and that the relative frequency of slow and less massive CMEs increases with decreasing sunspot number. We conclude that cycle 24 is not only producing fewer CMEs than cycle 23, but that these ejections also tend to be slower and less massive than those observed one cycle earlier.

  6. Comparison of a Global Magnetic Evolution Model with Observations of Coronal Mass Ejections

    CERN Document Server

    Yeates, A R; Nandy, Dibyendu; Mackay, D H; Martens, P C H; van Ballegooijen, A A

    2009-01-01

    The relative importance of different initiation mechanisms for coronal mass ejections (CMEs) on the Sun is uncertain. One possible mechanism is the loss of equilibrium of coronal magnetic flux ropes formed gradually by large-scale surface motions. In this paper, the locations of flux rope ejections in a recently-developed quasi-static global evolution model are compared with observed CME source locations over a 4.5-month period in 1999. Using EUV data, the low-coronal source locations are determined unambiguously for 98 out of 330 CMEs. Despite the incomplete observations, positive correlation (with coefficient up to 0.49) is found between the distributions of observed and simulated ejections, but only when binned into periods of one month or longer. This binning timescale corresponds to the time interval at which magnetogram data are assimilated into the coronal simulations, and the correlation arises primarily from the large-scale surface magnetic field distribution; only a weak dependence is found on the m...

  7. Velocities and relative amount of material ejected from Comet 9P/Tempel 1 after the Deep Impact collision

    CERN Document Server

    Ipatov, Sergei I

    2008-01-01

    Time variations of velocities and relative amount of material ejected from Comet 9P/Tempel 1 are studied based on analysis of the images made by Deep Impact (DI) cameras during the first 13 minutes after the collision of the DI impactor with the comet. The rate of production of observed ejected material and velocities considered correspond mainly to small (with diameter d1 s can be considered to be proportional to te^{-0.75} or te^{-0.7 }, but the decrease of velocity could differ from this exponential dependence. Comparison of the observed DI ejection with theoretical models testifies in favor of a model close to gravity-dominated cratering, i.e. in favor of greater amounts of ejected material and greater size of a crater.

  8. Comparison of characteristics and outcomes of patients with heart failure preserved ejection fraction versus reduced left ventricular ejection fraction in an urban cohort.

    Science.gov (United States)

    Quiroz, Rene; Doros, Gheorghe; Shaw, Peter; Liang, Chang-Seng; Gauthier, Diane F; Sam, Flora

    2014-02-15

    Despite significant advances in therapies for patients with heart failure with reduced ejection fraction (HFrEF), there are no evidence-based therapies for heart failure with preserved ejection fraction (HFpEF), also known as diastolic heart failure (HF). Differences in pathophysiologic mechanisms are touted as to why patients with HFpEF purportedly do not derive similar therapeutic benefits compared with HFrEF. Similarly, the relative frequencies of HFpEF and HFrEF may differ between hospitalized and ambulatory settings. There are limited data on the prevalence, characteristics, treatment, and short-term outcomes of patients hospitalized with HFpEF. We sought to investigate these in patients hospitalized with HFpEF in an urban, hospitalized setting using the Get With The Guidelines registry. We retrospectively reviewed all consecutive discharges (n = 1,701) with a diagnosis of acute decompensated HF from December 1, 2006 to September 30, 2008. Patients with HFpEF (n = 499) were older, overweight, predominantly women, and had underlying hypertension and dyslipidemia. Presenting blood pressure and levels of creatinine were higher, with lower brain natriuretic peptide levels compared with patients with HFrEF (n = 598). Length of stay and 30-day mortality were comparable between patients with HFpEF and HFrEF. Thirty-day readmission was initially lower in patients with HFpEF. However 30-day mortality from any cause after the index HF hospitalization and survival curve at 1-year was no different between patients with HFpEF and HFrEF. In conclusion, lower 30-day readmissions do not translate into improved long-term outcome in patients with HFpEF. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Microwave radio emissions as a proxy for coronal mass ejection speed in arrival predictions of interplanetary coronal mass ejections at 1 AU

    Science.gov (United States)

    Matamoros, Carolina Salas; Klein, Karl Ludwig; Trottet, Gerard

    2017-01-01

    The propagation of a coronal mass ejection (CME) to the Earth takes between about 15 h and several days. We explore whether observations of non-thermal microwave bursts, produced by near-relativistic electons via the gyrosynchrotron process, can be used to predict travel times of interplanetary coronal mass ejections (ICMEs) from the Sun to the Earth. In a first step, a relationship is established between the CME speed measured by the Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph (SoHO/LASCO) near the solar limb and the fluence of the microwave burst. This relationship is then employed to estimate speeds in the corona of earthward-propagating CMEs. These speeds are fed into a simple empirical interplanetary acceleration model to predict the speed and arrival time of the ICMEs at Earth. The predictions are compared with observed arrival times and with the predictions based on other proxies, including soft X-rays (SXR) and coronographic measurements. We found that CME speeds estimated from microwaves and SXR predict the ICME arrival at the Earth with absolute errors of 11 ± 7 and 9 ± 7 h, respectively. A trend to underestimate the interplanetary travel times of ICMEs was noted for both techniques. This is consistent with the fact that in most cases of our test sample, ICMEs are detected on their flanks. Although this preliminary validation was carried out on a rather small sample of events (11), we conclude that microwave proxies can provide early estimates of ICME arrivals and ICME speeds in the interplanetary space. This method is limited by the fact that not all CMEs are accompanied by non-thermal microwave bursts. But its usefulness is enhanced by the relatively simple observational setup and the observation from ground, which makes the instrumentation less vulnerable to space weather hazards.

  10. Prevalence and prognosis of heart failure with preserved ejection fraction and elevated N-terminal pro brain natriuretic peptide

    DEFF Research Database (Denmark)

    Carlsen, Christian Malchau; Bay, Morten; Kirk, Vibeke

    2012-01-01

    The aim of this study was to assess the epidemiological features and prognosis of heart failure with preserved ejection fraction (HFPEF) and to compare these findings with those from patients with reduced ejection fraction. Furthermore the effects of N-terminal pro brain natriuretic peptide (NT-pro......BNP) requirement in the heart failure diagnosis were assessed by repeating the analyses in the subgroup of patients with elevated NT-proBNP....

  11. Study of the fluence dependent interplay between laser induced material removal mechanisms in metals: Vaporization, melt displacement and melt ejection

    Energy Technology Data Exchange (ETDEWEB)

    Fishburn, J.M. [Centre for Lasers and Applications, Department of Physics, Macquarie University, Sydney 2109 (Australia); Withford, M.J. [Centre for Lasers and Applications, Department of Physics, Macquarie University, Sydney 2109 (Australia)]. E-mail: withford@ics.mq.edu.au; Coutts, D.W. [Centre for Lasers and Applications, Department of Physics, Macquarie University, Sydney 2109 (Australia); Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Piper, J.A. [Centre for Lasers and Applications, Department of Physics, Macquarie University, Sydney 2109 (Australia)

    2006-05-15

    Three quantitative methods, namely profilometry, high speed imaging and recoil momentum measurements using a ballistic pendulum, are used to determine the interplay of vaporization, melt displacement and melt ejection on nanosecond laser induced material removal. At low to moderate fluences (<7 J cm{sup -2}) material removal occurs via vaporization and melt displacement in aluminium. At high fluences (>7 J cm{sup -2}), material removal occurs predominantly via the explosive ejection of liquid droplets from the melt pool.

  12. Ispitivanje piropatrona i raketnog motora pilotskog sedišta / Testing pyrocartridges and the rocket motor of the ejection seat

    Directory of Open Access Journals (Sweden)

    Milorad Savković

    2008-04-01

    Full Text Available Raketni motor pilotskog sedišta ima složen geometrijski oblik, tako da njegov potisak deluje pod određenim uglom u odnosu na ravan simetrije pilotskog sedišta. Radi određivanja intenziteta i napadne linije potiska izvršen je veći broj eksperimenata. Meren je potisak raketnog motora na višekomponentnom opitnom stolu. Letno ispitivanje pilotskog sedišta obavljeno je pomoću lutke koja simulira masu pilota. Takođe, analizirano je letno ispitivanje pilotskog sedišta u početnom periodu katapultiranja za vreme rada raketnog motora. Obrađeni su i rezultati merenja ubrzanja, koji su korišćeni za određivanje karakteristika leta pilotskog sedišta. U radu je prikazan teorijski model kretanja sedišta. / Due to a complex geometrical shape of the rocket motor of the ejection seat, the rocket motor thrust occurs under certain angle in relation to the plane of symmetry of the ejection seat. A number of tests were carried out in order to determine thrust intensity and angle of attack. The rocket motor thrust was measured on the multicomponent test stand. The ejection seat whit a dummy simulating a mass of a pilot was tested during ejection. The paper presents an analysis of the ejection seat flight in the initial phase of ejection, during the rocket motor running. The results of the acceleration read-outs were processed and then used for the determination of the characteristics of the ejection seat flight. A theoretical model of the ejection seat flight is given in the paper.

  13. Regulation of DNA Translocation Efficiency within the Chromatin Remodeler RSC/Sth1 Potentiates Nucleosome Sliding and Ejection.

    Science.gov (United States)

    Clapier, Cedric R; Kasten, Margaret M; Parnell, Timothy J; Viswanathan, Ramya; Szerlong, Heather; Sirinakis, George; Zhang, Yongli; Cairns, Bradley R

    2016-05-01

    The RSC chromatin remodeler slides and ejects nucleosomes, utilizing a catalytic subunit (Sth1) with DNA translocation activity, which can pump DNA around the nucleosome. A central question is whether and how DNA translocation is regulated to achieve sliding versus ejection. Here, we report the regulation of DNA translocation efficiency by two domains residing on Sth1 (Post-HSA and Protrusion 1) and by actin-related proteins (ARPs) that bind Sth1. ARPs facilitated sliding and ejection by improving "coupling"-the amount of DNA translocation by Sth1 relative to ATP hydrolysis. We also identified and characterized Protrusion 1 mutations that promote "coupling," and Post-HSA mutations that improve ATP hydrolysis; notably, the strongest mutations conferred efficient nucleosome ejection without ARPs. Taken together, sliding-to-ejection involves a continuum of DNA translocation efficiency, consistent with higher magnitudes of ATPase and coupling activities (involving ARPs and Sth1 domains), enabling the simultaneous rupture of multiple histone-DNA contacts facilitating ejection.

  14. Effects of pulling forces, osmotic pressure, condensing agents and viscosity on the thermodynamics and kinetics of DNA ejection from bacteriophages to bacterial cells: a computational study

    Science.gov (United States)

    Petrov, Anton S.; Douglas, Scott S.; Harvey, Stephen C.

    2013-03-01

    In this work, we report on simulations of double-stranded DNA (dsDNA) ejection from bacteriophage ϕ29 into a bacterial cell. The ejection was studied with a coarse-grained model, in which viral dsDNA was represented by beads on a torsion-less string. The bacteriophage’s capsid and the bacterial cell were defined by sets of spherical constraints. To account for the effects of the viscous medium inside the bacterial cell, the simulations were carried out using a Langevin dynamics protocol. Our simplest simulations (involving constant viscosity and no external biasing forces) produced results compatible with the push-pull model of DNA ejection, with an ejection rate significantly higher in the first part of ejection than in the latter parts. Additionally, we performed more complicated simulations, in which we included additional factors such as external forces, osmotic pressure, condensing agents and ejection-dependent viscosity. The effects of these factors (independently and in combination) on the thermodynamics and kinetics of DNA ejection were studied. We found that, in general, the dependence of ejection forces and ejection rates on the amount of DNA ejected becomes more complex if the ejection is modeled with a broader, more realistic set of parameters and influences (such as variation in the solvent’s viscosity and the application of an external force). However, certain combinations of factors and numerical parameters led to the opposition of some ejection-driving and ejection-inhibiting influences, ultimately causing an apparent simplification of the ejection profiles.

  15. The importance of hemodynamic monitoring in mitrocuspid surgery

    OpenAIRE

    Dobrić Biljana J.; Petrović Jasna S.; Radovanović Ninoslav D.

    2006-01-01

    Introduction. Untreated mitral valve disease is associated with marked hemodynamic disorders, low ejection fraction (EF) and poor perfusion. The study aimed to explore the importance of hemodynamic monitoring in intraoperative evaluation and treatment of these patients. Material and methods. This prospective study included 85 patients: group I: 41 patients, EF<40%; group II: 44 patients, EF>40%. Hemodynamic parameters were recorded after initation of anesthesia (1), after sternotomy (2)...

  16. BNP cannot replace gated equilibrium radionuclide ventriculography in monitoring of anthracycline-induced cardiotoxity

    DEFF Research Database (Denmark)

    Vogelsang, T.W.; Jensen, R.J.; Hesse, B.;

    2007-01-01

    BACKGROUND: Cardiotoxity is a side-effect of cancer treatment with anthracycline that is currently monitored by measuring the left ventricular ejection fraction (LVEF) by gated equilibrium radionuclide ventriculography (RNV). We hypothesized that BNP measurements could replace, at least in part...

  17. Automatically Detecting and Tracking Coronal Mass Ejections. I. Separation of Dynamic and Quiescent Components in Coronagraph Images

    Science.gov (United States)

    Morgan, Huw; Byrne, Jason P.; Habbal, Shadia Rifai

    2012-06-01

    Automated techniques for detecting and tracking coronal mass ejections (CMEs) in coronagraph data are of ever increasing importance for space weather monitoring and forecasting. They serve to remove the biases and tedium of human interpretation, and provide the robust analysis necessary for statistical studies across large numbers of observations. An important requirement in their operation is that they satisfactorily distinguish the CME structure from the background quiescent coronal structure (streamers, coronal holes). Many studies resort to some form of time differencing to achieve this, despite the errors inherent in such an approach—notably spatiotemporal crosstalk. This article describes a new deconvolution technique that separates coronagraph images into quiescent and dynamic components. A set of synthetic observations made from a sophisticated model corona and CME demonstrates the validity and effectiveness of the technique in isolating the CME signal. Applied to observations by the LASCO C2 and C3 coronagraphs, the structure of a faint CME is revealed in detail despite the presence of background streamers that are several times brighter than the CME. The technique is also demonstrated to work on SECCHI/COR2 data, and new possibilities for estimating the three-dimensional structure of CMEs using the multiple viewing angles are discussed. Although quiescent coronal structures and CMEs are intrinsically linked, and although their interaction is an unavoidable source of error in any separation process, we show in a companion paper that the deconvolution approach outlined here is a robust and accurate method for rigorous CME analysis. Such an approach is a prerequisite to the higher-level detection and classification of CME structure and kinematics.

  18. Investigation on occupant ejection in high severity rear impact based on post mortem human subject sled tests.

    Science.gov (United States)

    Petit, Philippe; Luet, Carole; Potier, Pascal; Vallancien, Guy

    2011-11-01

    Occupant protection in rear impact involves two competing challenges. On one hand, allowing a deformation of the seat would act as an energy absorber in low severity impacts and would consequently decrease the risk of neck injuries. However, on the other hand, large deformations of the seat may increase the likelihood of occupant ejection in high severity cases. Green et al. 1987 analyzed a total of 919 accidents in Great Britain. They found that occupant ejection resulted in a risk of severe injuries and fatalities between 3.6 and 4.5 times higher than those cases where no ejection was observed. The sample included single front, side and rear impacts as well as multiple impacts and rollover. The rate of belt use in the sample was 50%. While this analysis included all forms of impact scenarios, nevertheless, it highlights the relative injury severity of occupant ejection. Extensive literature search has found no full-scale rear impact tests involving Post Mortem Human Subjects (PMHS) conducted in a laboratory environment and resulting in ejection. This paper describes a total of 10 sled tests conducted on 3 belted PMHS using a simplified seat design composed of rigid plates assembled such that the angular and linear stiffness of the seatback (including the foam) was modeled. The initial angular position and the range of motion of the seatback, the size of the PMHS, the slack length of the seatbelt, the angular stiffness of the seatback, and the use of headrest were varied in the test matrix while the pulse was kept constant (triangular acceleration with a peak of 17 G at 30 ms and a duration of 95 ms). In the test series, the tests were not run randomly but the likelihood of occupant ejection was increased systematically until ejection occurred. PMHS seat ejection was observed only for the 95th percentile, initially positioned with a seatback angle relative to the vertical equal to 22°, a range of seatback angular motion equal to 44° and no headrest. Repeating

  19. Heart Failure with Preserved Ejection Fraction – Concept, Pathophysiology, Diagnosis and Challenges for Treatment

    Directory of Open Access Journals (Sweden)

    Lidija Veterovska Miljkovik

    2015-07-01

    Full Text Available Heart failure (HF with preserved left ventricular (LV ejection fraction (HFpEF occurs in 40 to 60% of the patients with HF, with a prognosis which is similar to HF with reduced ejection fraction (HFrEF. HFpEF pathophysiology is different from that of HFrEF, and has been characterized with diastolic dysfunction. Diastolic dysfunction has been defined with elevated left ventricular stiffness, prolonged iso-volumetric LV relaxation, slow LV filing and elevated LV end-diastolic pressure. Arterial hypertension occurs in majority cases with HFpEF worldwide. Patients are mostly older and obese. Diabetes mellitus and atrial fibrillation appear proportionally in a high frequency of patients with HFpEF. The HFpEF diagnosis is based on existence of symptoms and signs of heart failure, normal or approximately normal ejection and diagnosing of LV diastolic dysfunction by means of heart catheterization or Doppler echocardiography and/or elevated concentration of plasma natriuretic peptide. The present recommendations for HFpEF treatment include blood pressure control, heart chamber frequency control when atrial fibrillation exists, in some situations even coronary revascularization and an attempt for sinus rhythm reestablishment. Up to now, it is considered that no medication or a group of medications improve the survival of HFpEF patients. Due to these causes and the bad prognosis of the disorder, rigorous control is recommended of the previously mentioned precipitating factors for this disorder. This paper presents a universal review of the most important parameters which determine this disorder.

  20. Global Longitudinal Strain or Left Ventricular Twist and Torsion? Which Correlates Best with Ejection Fraction?

    Directory of Open Access Journals (Sweden)

    Marcio Silva Miguel Lima

    Full Text Available Abstract Background: Estimative of left ventricular ejection fraction (LVEF is a major indication for echocardiography. Speckle tracking echocardiography (STE allows analysis of LV contraction mechanics which includes global longitudinal strain (GLS and twist/torsion, both the most widely used. Direct comparison of correlations between these novel parameters and LVEF has never been done before. Objective: This study aims to check which one has the highest correlation with LVEF. Methods: Patients with normal LVEF (> 0,55 and systolic dysfunction (LVEF <0,55 were prospectively enrolled, and underwent echocardiogram with STE analysis. Correlation of variables was performed by linear regression analysis. In addition, correlation among levels of LV systolic impairment was also tested. Results: A total of 131 patients were included (mean age, 46 ± 14y; 43%, men. LVEF and GLS showed a strong correlation (r = 0.95; r2 = 0.89; p < 0.001, more evident in groups with LV systolic dysfunction than those with preserved LVEF. Good correlation was also found with global longitudinal strain rate (r = 0.85; r2 = 0.73; p < 0.001. Comparing to GLS, correlation of LVEF and torsional mechanics was weaker: twist (r = 0.78; r2 = 0.60; p < 0.001; torsion (r = 0.75; r2 = 0.56; p < 0.001. Conclusion: GLS of the left ventricle have highly strong positive correlation with the classical parameter of ejection fraction, especially in cases with LV systolic impairment. Longitudinal strain rate also demonstrated a good correlation. GLS increments analysis of LV systolic function. On the other hand, although being a cornerstone of LV mechanics, twist and torsion have a weaker correlation with LV ejection, comparing to GLS.

  1. Pulmonary Hypertension in Elderly Patients with Diastolic Dysfunction and Preserved Ejection Fraction

    Science.gov (United States)

    Afshar, Majid; Collado, Fareed; Doukky, Rami

    2012-01-01

    Purpose: Patients with diastolic dysfunction may have a disproportionate degree of elevation in pulmonary pressure, particularly in the elderly. Higher pulmonary vascular resistance in the elderly patients with heart failure but preserved ejection fraction suggests that beyond the post-capillary contribution of pulmonary venous congestion, a pre-capillary component of pulmonary arterial hypertension occurs. We aim to identify if pulmonary vascular resistance in elderly patients with diastolic dysfunction is disproportionately higher than patients with systolic dysfunction independent of filling pressures. Methods: 389 patients identified retrospectively between 2003- 2010; elderly with preserved ejection fraction, elderly with depressed ejection fraction, and primary arterial hypertension who underwent right-heart catheterization at Rush University. Results: No significant difference in pulmonary vascular resistance between systolic and diastolic dysfunction. The mean difference in pulmonary vascular resistance was not statistically significant at 0.40 mmHg·min/l (95% CI -3.03 to 3.83) with similar left ventricular filling pressures with mean difference of 3.38 mmHg (95% CI, -1.27 to 8.02). When adjusted for filling pressures, there remained no difference in pulmonary vascular resistance for systolic and diastolic dysfunction. The mean pulmonary vascular resistance is more elevated in systolic heart failure compared to diastolic heart failure with means 3.13 mmHg·min/l and 3.52 mmHg·min/l, respectively. Conclusion: There was no other association identified for secondary pulmonary hypertension other than diastolic dysfunction and chronic venous pulmonary hypertension. Our results argue against any significant arterial remodeling that would lead to disproportionate pre-capillary hypertension, and implies that treatment should focus on lowering filling pressure rather than treating the pulmonary vascular tree. PMID:22282715

  2. Mid-range Ejection Fraction Does Not Permit Risk Stratification Among Patients Hospitalized for Heart Failure.

    Science.gov (United States)

    Gómez-Otero, Inés; Ferrero-Gregori, Andreu; Varela Román, Alfonso; Seijas Amigo, José; Pascual-Figal, Domingo A; Delgado Jiménez, Juan; Álvarez-García, Jesús; Fernández-Avilés, Francisco; Worner Diz, Fernando; Alonso-Pulpón, Luis; Cinca, Juan; Gónzalez-Juanatey, José Ramón

    2017-05-01

    European Society of Cardiology heart failure guidelines include a new patient category with mid-range (40%-49%) left ventricular ejection fraction (HFmrEF). HFmrEF patient characteristics and prognosis are poorly defined. The aim of this study was to analyze the HFmrEF category in a cohort of hospitalized heart failure patients (REDINSCOR II Registry). A prospective observational study was conducted with 1420 patients classified according to ejection fraction as follows: HFrEF, < 40%; HFmrEF, 40%-49%; and HFpEF, ≥ 50%. Baseline patient characteristics were examined, and outcome measures were mortality and readmission for heart failure at 1-, 6-, and 12-month follow-up. Propensity score matching was used to compare the HFmrEF group with the other ejection fraction groups. Among the study participants, 583 (41%) had HFrEF, 227 (16%) HFmrEF, and 610 (43%) HFpEF. HFmrEF patients had a clinical profile similar to that of HFpEF patients in terms of age, blood pressure, and atrial fibrillation prevalence, but shared with HFrEF patients a higher proportion of male participants and ischemic etiology, and use of class I drugs targeting HFrEF. All other features were intermediate, and comorbidities were similar among the 3 groups. There were no significant differences in all-cause mortality, cause of death, or heart failure readmission. The similar outcomes were confirmed in the propensity score matched cohorts. The HFmrEF patient group has characteristics between the HFrEF and HFpEF groups, with more similarities to the HFpEF group. No between-group differences were observed in total mortality, cause of death, or heart failure readmission. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  3. Natriuretic peptides and Galectin-3 in senile heart failure patients with preserved ejection fraction.

    Directory of Open Access Journals (Sweden)

    Malinova L.I.

    2015-03-01

    Full Text Available Purpose: to characterize biomarker panel in senile patients with heart failure with preserved ejection fraction (HF-pEF. Material and Methods. 356 senile patients with chronic heart failure with preserved ejection fraction (HFpEF were examined to form the study sample of 48 male patients without atrium fibrillation, anemia, diabetes mellitus, onco-pathology and missing clinical data. NT-proBNP, galectin-3 (gal-3 and proANT assay was performed by commercially available ELISA kits. Results. In patients without left ventricular (LV regional wall motion abnormalities (RWMA. gal-3 (2,13 (0,98; 3,50 vs 5.16 (4,34;9.63 ng/mL, p = 0.011 and NT-proBNP (5,59 (1,00; 10.13 vs 32,04 (15,40; 46,18 fmol/mL, p=0,006 levels were significantly lower than in patients with LV RWMA. Contrarily proANP level was lower in patients with LV RWMA (3,24 (2,47; 3,75 vs 1,38 (0,83; 2,29 nmol/mL, p=0.071. proANP was the only biomarker to increase significantly in long livers (7,30 (4,52; 7,63 vs 2,68 (1,88; 3,32 nmol/mL, p=0.006. NT-proBNP positively correlated with glucose level and negatively with hsCRP (R=0,52, p=0,007. Conclusion. Biomarker panel in senile heart failure patients with preserved ejection fraction has characterized: increase in NT-proBNP and galectin-3 is associated with more severe clinical course and presence of regional wall motion abnormalities in senile patients.

  4. Stoichiometric relationship between energy-dependent proton ejection and electron transport in mitochondria.

    Science.gov (United States)

    Brand, M D; Reynafarje, B; Lehninger, A L

    1976-02-01

    The number of protons ejected during electron transport per pair of electrons per energy-conserving site (the H+/site ratio) was measured in rat liver mitochondria by three different methods under conditions in which transmembrane movements of endogenous phosphate were minized or eliminated. (1) In the Ca2+ pulse method, between 3.5 and 4.0 molecules of 3-hydroxybutyrate and 1.75 to 2.0 Ca2+ ions were accumulated per 2 e- per site during Ca2+ induced electron transport in the presence of rotenone, when measured under conditions in which movements of endogenous phosphate were negligible. Since entry of 3-hydroxybutyrate requires its protonation to the free acid these data correspond to an H+/site ratio of 3.5-4.0 (2) In the oxygen pulse method addition of known amounts of oxygen to anaerobic mitochondria in the presence of substrate yielded H+/site ratios of 3.0 when phosphate transport was eliminated by addition of N-ethylmaleimide or by anaerobic washing to remove endogenous phosphate. In the absence of such measures the observed H+/site ratio was 2.0. (3) In the reductant pulse method measurement of the initial steady rates of H+ ejection and oxygen consumption by mitochondria in an aerobic medium after addition of substrate gave H+/site near 4.0 in the presence of N-ethylmaleimide; in the absence of the inhibitor the observed ratio was only 2.0. These and other experiments reported indicate that the values of 2.0 earlier obtained for the H+/site ratio by Mitchell and Moyle [Biochem J. (1967) 105, 1147-1162] and others were underestimates due to the unrecognized masking of H+ ejection by movements of endogenous phosphate. The results presented here show that the H+/site ratio of mitochondrial electron transport is at least 3.0 and may be as high as 4.0.

  5. Extreme jet ejections from the black hole X-ray binary V404 Cygni

    Science.gov (United States)

    Tetarenko, A. J.; Sivakoff, G. R.; Miller-Jones, J. C. A.; Rosolowsky, E. W.; Petitpas, G.; Gurwell, M.; Wouterloot, J.; Fender, R.; Heinz, S.; Maitra, D.; Markoff, S. B.; Migliari, S.; Rupen, M. P.; Rushton, A. P.; Russell, D. M.; Russell, T. D.; Sarazin, C. L.

    2017-08-01

    We present simultaneous radio through sub-mm observations of the black hole X-ray binary (BHXB) V404 Cygni during the most active phase of its June 2015 outburst. Our 4 h long set of overlapping observations with the Very Large Array, the Sub-millimeter Array and the James Clerk Maxwell Telescope (SCUBA-2) covers eight different frequency bands (including the first detection of a BHXB jet at 666 GHz/450 μm), providing an unprecedented multifrequency view of the extraordinary flaring activity seen during this period of the outburst. In particular, we detect multiple rapidly evolving flares, which reach Jy-level fluxes across all of our frequency bands. With this rich data set, we performed detailed MCMC modelling of the repeated flaring events. Our custom model adapts the van der Laan synchrotron bubble model to include twin bi-polar ejections, propagating away from the black hole at bulk relativistic velocities, along a jet axis that is inclined to the line of sight. The emission predicted by our model accounts for projection effects, relativistic beaming and the geometric time delay between the approaching and receding ejecta in each ejection event. We find that a total of eight bi-polar, discrete jet ejection events can reproduce the emission that we observe in all of our frequency bands remarkably well. With our best-fitting model, we provide detailed probes of jet speed, structure, energetics and geometry. Our analysis demonstrates the paramount importance of the mm/sub-mm bands, which offer a unique, more detailed view of the jet than can be provided by radio frequencies alone.

  6. MULTIPLE PLASMA EJECTIONS AND INTERMITTENT NATURE OF MAGNETIC RECONNECTION IN SOLAR CHROMOSPHERIC ANEMONE JETS

    Energy Technology Data Exchange (ETDEWEB)

    Singh, K. A. P.; Nishida, K.; Shibata, K. [Kwasan and Hida Observatories, Graduate School of Science, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Isobe, H. [Unit of Synergetic Study for Space, Kyoto University, Yamashina, Kyoto 607-8471 (Japan); Nishizuka, N., E-mail: singh@kwasan.kyoto-u.ac.jp, E-mail: nishida@kwasan.kyoto-u.ac.jp, E-mail: shibata@kwasan.kyoto-u.ac.jp, E-mail: isobe@kwasan.kyoto-u.ac.jp, E-mail: nishizuka.naoto@jaxa.jp [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara-shi, Kanagawa 229-8510 (Japan)

    2012-11-01

    The recent discovery of chromospheric anemone jets with the Solar Optical Telescope (SOT) on board Hinode has shown an indirect evidence of magnetic reconnection in the solar chromosphere. However, the basic nature of magnetic reconnection in chromosphere is still unclear. We studied nine chromospheric anemone jets from SOT/Hinode using Ca II H filtergrams, and we found multiple bright, plasma ejections along the jets. In most cases, the major intensity enhancements (larger than 30% relative to the background intensity) of the loop correspond to the timing of the plasma ejections. The typical lifetime and size of the plasma ejecta are about 20-60 s and 0.3-1.5 Mm, respectively. The height-time plot of jet shows many sub-structures (or individual jets) and the typical lifetime of the individual jet is about one to five minutes. Before the onset of the jet activity, a loop appears in Ca II H and gradually increases in size, and after few minutes several jets are launched from the loop. Once the jet activity starts and several individual jets are launched, the loop starts shrinking with a speed of {approx}4 km s{sup -1}. In some events, a downward moving blob with a speed of {approx}35 km s{sup -1} was observed, associated with the upward moving plasma along one of the legs of the loop hosting the jets. The upward moving plasma gradually developed into jets. Multiple plasma ejections in chromospheric anemone jet show the strongly time-dependent as well as intermittent nature of magnetic reconnection in the solar chromosphere.

  7. Are We Observing Coronal Mass Ejections in OH/IR AGB Stars?

    Science.gov (United States)

    Heiles, Carl

    2017-05-01

    Solar Coronal Mass Ejections (CMEs) are magnetic electron clouds that are violently ejected by the same magnetic reconnection events that produce Solar flares. CMEs are the major driving source of the hazardous space weather environments near the Earth. In exoplanet systems, the equivalent of Solar wind and CMEs can affect a planet's atmosphere, and in extreme cases can erode it, as probably happened with Mars, or disrupt the cosmic-ray shielding aspect of the planet's magnetic field.We (Jensen et al. 2013SoPh..285...83J, 2016SoPh..291..465J) have developed a new way to observe the electron column density and magnetic field of CMEs, namely to measure the frequency change and Faraday rotation of a spacecraft downlink carrier produced by propagation effects in the plasma. Surprisingly, this can work on other stars if they have the equivalent of the spacecraft carrier, as do OH/IR stars.OH/IR stars are Asymptotic Giant Branch (AGB) stars, which are red giant stars burning He in their final stages of stellar evolution. They have highly convective surfaces and large mass-ejection rates in the form of expanding dense shells of molecular gas and obscuring dust, which were ejected from the star by chaotic turbulent motions and then accelerated by radiation pressure. OH masers reside in these shells, pumped by the IR emission from the dust. The OH masers on the far side of the star (i.e., the positive-velocity masers) are the surrogate for the Solar-case spacecraft signal.The big question: Can we see CMEs in OH/IR stars? We have observed six OH/IR stars with the Arecibo Observatory for a total of about 150 hours over the past 1.5 years. We see changes in OH maser frequency and in the position angle of linear polarization. Both can be produced by electron clouds moving across the line of sight. We will present statistical summaries of the variability and interpret them in terms of CME models.

  8. Assessment of right ventricular ejection fraction during intravenous /sup 133/Xe pulmonary ventilation study

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, S.M.; Spencer, R.P.; Herrera, N.E.

    1985-01-01

    Intravenous /sup 133/Xe in saline was used to estimate right-ventricular ejection fraction (RVEF). In three healthy volunteers, the first pass RVEF with /sup 133/Xe was followed by RVEF estimation by intravenous /sup 99m/Tc-pertechnetate. There was agreement between the /sup 133/Xe and 99mTc determined values. Subjects rebreathed the liberated /sup 133/Xe gas, allowing an estimation of regional pulmonary ventilation. Intravenous /sup 133/Xe in saline may have potential use in measuring RVEF, as well as in evaluating pulmonary function in cor pulmonale.

  9. Investigation of the Large Scale Evolution and Topology of Coronal Mass Ejections in the Solar Wind

    Science.gov (United States)

    Riley, Peter

    1999-12-01

    This investigation is concerned with the large-scale evolution and topology of Coronal Mass Ejections (CMEs) in the solar wind. During this reporting period we have analyzed a series of low density intervals in the ACE (Advanced Composition Explorer) plasma data set that bear many similarities to CMEs. We have begun a series of 3D, MHD (Magnetohydrodynamics) coronal models to probe potential causes of these events. We also edited two manuscripts concerning the properties of CMEs in the solar wind. One was re-submitted to the Journal of Geophysical Research.

  10. The Accretion-Ejection Instability and a "Magnetic Flood" scenario for GRS 1915+105

    CERN Document Server

    Tagger, M

    2000-01-01

    I present a global view of recent results on the Accretion-Ejection Instability (AEI), described in more details in other contributions to this workshop. These results address essentially the characteristics of the AEI as a good candidate to explain the low-frequency QPO of X-ray binaries, in particular (at $\\sim 1-10$ Hz) of micro-quasars. I then discuss how, if the AEI is considered as the source of the QPO, a possible scenario can be considered where the $\\sim 30$ mn. cycles of GRS 1915+105 are controlled by the evolution of magnetic flux in the disk.

  11. Energy of coronal mass ejections and large-scale structure of solar magnetic fields

    Science.gov (United States)

    Ivanov, E. V.

    2016-12-01

    The relationship between variations of the energy and linear velocity of coronal mass ejections (CME) and the typical dimensions of structural elements of the large-scale solar magnetic field structure (LSMFS) is investigated for the period of 1996-2014. It is shown that the maximum linear velocity and maximum energy of CME correspond to the values of the effective solar multipole index n 4.0-4.4. These values determine the maximum size of the complexes of active regions, which, together with the observed maximum values of magnetic field intensity in the complexes, limit the possible maximum CME energy.

  12. Rod ejection simulation on VVER 1000/320 core using PARCS/TRACE

    OpenAIRE

    Ruscak, Marek

    2016-01-01

    The rod ejection (RE) is a design basis accident in accordance with NUREG-0800 and usually studied using point kinetics. In this thesis a 3D kinetic model is prepared and coupled with a thermal hydraulic system code for simulating this accident scenario for general VVER 1000 technology. This topic has been defined by the Research Centre Rez of the Czech Republic as a part of a larger project concerning beyond design basis accident focused on the Station Black Out (SBO) and a Lo...

  13. Clinical perspectives and evidence of diastolic stress test in heart failure with preserved ejection fraction

    Directory of Open Access Journals (Sweden)

    Evgeny Belyavskiy

    2015-12-01

    Full Text Available The diagnosis of heart failure with preserved ejection fraction (HFPEF remains on the basis of echocardiographic analyses at rest. However, some patients with HFPEF have symptoms such as dyspnea only during exercise. Accordingly, echocardiographic analyses at rest could be insufficiently sensitive to identify these patients. In line, recent studies demonstrated that in some patients with HFPEF left ventricular diastolic abnormalities occur only during exercise. This review discusses and analyzes the clinical relevance and evidence of using diastolic stress test echocardiography in patients with HFPEF.

  14. Diagnosis and Management of Heart Failure with Preserved Ejection Frac-tion: 10 Key Lessons

    OpenAIRE

    A, Afşin Oktay; Sanjiv J Shah

    2015-01-01

    Heart failure with preserved ejection fraction (HFpEF) is a common clinical syndrome associated with high rates of morbidi-ty and mortality. Due to the lack of evidence-based therapies and increasing prevalence of HFpEF, clinicians are often con-fronted with these patients and yet have little guidance on how to effectively diagnose and manage them. Here we offer 10 key lessons to assist with the care of patients with HFpEF: (1) Know the difference between diastolic dysfunction, diastolic hear...

  15. The role of temperature with unexpected ejection of gas and rock

    Energy Technology Data Exchange (ETDEWEB)

    Somosvari, Z.

    1984-01-01

    An analysis is conducted of the physical and chemical laws for storing gas. The effect of the temperature of the rock on the content of gas in a gas storage facility and the pressure of the gas are studied. It is established that in the formation of an unexpected gas and rock ejection the temperature of the rock only has an indirect role which effects the pressure of the gas in the pores. It is also pointed out that with slow liberation of gas the temperature of the rock may play a more specific role.

  16. Latitudinal Distribution of Solar Flares and Their Association with Coronal Mass Ejections

    Institute of Scientific and Technical Information of China (English)

    Pankaj K. Shrivastava; Neelam Singh

    2005-01-01

    Major solar flare events have been utilised to study the latitudinal frequency distribution of solar flares in northern and southern hemispheres for the period of 1986 to 2003. A statistical analysis has been performed to obtain the correlation between Coronal Mass Ejections (CMEs) and Forbush decrease (Fds)of cosmic ray intensity. Almost the same flares distribution in both hemispheres is found in association with CMEs. In a further analysis, it is noted that a larger number of CME-associated solar flares located in the northern hemisphere are found to be more effective in producing Forbush decreases.

  17. On Subthreshold Ionization of Helium Droplets, Ejection of He+, and the Role of Anions

    CERN Document Server

    Renzler, Michael; Weinberger, Nikolaus; Denifl, Stephan; Scheier, Paul; Echt, Olof

    2016-01-01

    The mechanism of ionization of helium droplets has been investigated in numerous reports but one observation has not found a satisfactory explanation: How are $He^+$ ions formed and ejected from undoped droplets at electron energies below the ionization threshold of the free atom? Does this path exist at all? A measurement of the ion yields of $He^+$ and $He_2^+$ as a function of electron energy, electron emission current, and droplet size reveals that metastable $He^{*-}$ anions play a crucial role in the formation of free $He^+$ at subthreshold energies. The proposed model is testable.

  18. Large density amplification measured on jets ejected from a magnetized plasma gun

    OpenAIRE

    Yun, Gunsu S.; You, Setthivoine; Bellan, Paul M.

    2007-01-01

    Observation of a large density amplification in the collimating plasma jet ejected from a coplanar coaxial plasma gun is reported. The jet velocity is ~30 km s^-1 and the electron density increases from ~10^20 to 10^(22–23) m^-3. In previous spheromak experiments, electron density of the order 10^(19–21) m^-3 had been measured in the flux conserver region, but no density measurement had been reported for the source gun region. The coplanar geometry of our electrodes permits direct observation...

  19. Solar Coronal Mass Ejection as a Result of Magnetic Helicity Accumulation in the Corona

    Institute of Scientific and Technical Information of China (English)

    ZHANG Mei

    2011-01-01

    Coronal mass ejections (CMEs) are a major form of solar activities. A CME takes away 10^15-16 g of plasma from solar low corona, to disturb the near-Earth space if the CME direction is favorable. Here we summarize our understandings and reasoning that lead us to conclude that CMEs are the unavoidable products of magnetic helicity accumulation in the corona. Our study puts the formation of magnetic flux ropes and CME eruptions as natural and unavoidable results of coronal evolution.

  20. Two massive stars possibly ejected from NGC 3603 via a three-body encounter

    OpenAIRE

    2012-01-01

    We report the discovery of a bow-shock-producing star in the vicinity of the young massive star cluster NGC 3603 using archival data of the Spitzer Space Telescope. Follow-up optical spectroscopy of this star with Gemini-South led to its classification as O6 V. The orientation of the bow shock and the distance to the star (based on its spectral type) suggest that the star was expelled from the cluster, while the young age of the cluster (~2 Myr) implies that the ejection was caused by a dynam...

  1. A Space weather information service based upon remote and in-situ measurements of coronal mass ejections heading for Earth

    Directory of Open Access Journals (Sweden)

    Ritter Birgit

    2015-01-01

    Full Text Available The Earth’s magnetosphere is formed as a consequence of interaction between the planet’s magnetic field and the solar wind, a continuous plasma stream from the Sun. A number of different solar wind phenomena have been studied over the past 40 years with the intention of understanding and forecasting solar behavior. One of these phenomena in particular, Earth-bound interplanetary coronal mass ejections (CMEs, can significantly disturb the Earth’s magnetosphere for a short time and cause geomagnetic storms. This publication presents a mission concept consisting of six spacecraft that are equally spaced in a heliocentric orbit at 0.72 AU. These spacecraft will monitor the plasma properties, the magnetic field’s orientation and magnitude, and the 3D-propagation trajectory of CMEs heading for Earth. The primary objective of this mission is to increase space weather forecasting time by means of a near real-time information service, that is based upon in-situ and remote measurements of the aforementioned CME properties. The obtained data can additionally be used for updating scientific models. This update is the mission’s secondary objective. In-situ measurements are performed using a Solar Wind Analyzer instrumentation package and fluxgate magnetometers, while for remote measurements coronagraphs are employed. The proposed instruments originate from other space missions with the intention to reduce mission costs and to streamline the mission design process. Communication with the six identical spacecraft is realized via a deep space network consisting of six ground stations. They provide an information service that is in uninterrupted contact with the spacecraft, allowing for continuous space weather monitoring. A dedicated data processing center will handle all the data, and then forward the processed data to the SSA Space Weather Coordination Center which will, in turn, inform the general public through a space weather forecast. The data

  2. MULTI-POINT SHOCK AND FLUX ROPE ANALYSIS OF MULTIPLE INTERPLANETARY CORONAL MASS EJECTIONS AROUND 2010 AUGUST 1 IN THE INNER HELIOSPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Moestl, C.; Liu, Y.; Luhmann, J. G. [Space Science Laboratory, University of California, Berkeley, CA (United States); Farrugia, C. J. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH (United States); Kilpua, E. K. J. [Department of Physics, University of Helsinki, FI-00560 Helsinki (Finland); Jian, L. K. [Department of Astronomy, University of Maryland, College Park, MD (United States); Eastwood, J. P.; Forsyth, R. [The Blackett Laboratory, Imperial College, London (United Kingdom); Harrison, R. A.; Davies, J. A. [RAL Space, Harwell Oxford, Didcot (United Kingdom); Webb, D. F. [Institute for Scientific Research, Boston College, Newton, MA (United States); Temmer, M.; Rollett, T.; Veronig, A. M. [Kanzelhoehe Observatory-IGAM, Institute of Physics, University of Graz, A-8010 Graz (Austria); Odstrcil, D. [NASA Goddard Space Flight Center, Greenbelt, MD (United States); Nitta, N. [Solar and Astrophysics Laboratory, Lockheed Martin Advanced Technology Center, Palo Alto, CA (United States); Mulligan, T. [Space Science Applications Laboratory, The Aerospace Corporation, El Segundo, CA (United States); Jensen, E. A. [ACS Consulting, Houston, TX (United States); Lavraud, B. [Institut de Recherche en Astrophysique et Planetologie, Universite de Toulouse (UPS), F-31400 Toulouse (France); De Koning, C. A., E-mail: christian.moestl@uni-graz.at [NOAA/SWPC, Boulder, Colorado (United States); and others

    2012-10-10

    We present multi-point in situ observations of a complex sequence of coronal mass ejections (CMEs) which may serve as a benchmark event for numerical and empirical space weather prediction models. On 2010 August 1, instruments on various space missions, Solar Dynamics Observatory/Solar and Heliospheric Observatory/Solar-TErrestrial-RElations-Observatory (SDO/SOHO/STEREO), monitored several CMEs originating within tens of degrees from the solar disk center. We compare their imprints on four widely separated locations, spanning 120 Degree-Sign in heliospheric longitude, with radial distances from the Sun ranging from MESSENGER (0.38 AU) to Venus Express (VEX, at 0.72 AU) to Wind, ACE, and ARTEMIS near Earth and STEREO-B close to 1 AU. Calculating shock and flux rope parameters at each location points to a non-spherical shape of the shock, and shows the global configuration of the interplanetary coronal mass ejections (ICMEs), which have interacted, but do not seem to have merged. VEX and STEREO-B observed similar magnetic flux ropes (MFRs), in contrast to structures at Wind. The geomagnetic storm was intense, reaching two minima in the Dst index ( Almost-Equal-To - 100 nT), and was caused by the sheath region behind the shock and one of two observed MFRs. MESSENGER received a glancing blow of the ICMEs, and the events missed STEREO-A entirely. The observations demonstrate how sympathetic solar eruptions may immerse at least 1/3 of the heliosphere in the ecliptic with their distinct plasma and magnetic field signatures. We also emphasize the difficulties in linking the local views derived from single-spacecraft observations to a consistent global picture, pointing to possible alterations from the classical picture of ICMEs.

  3. A Tool for Empirical Forecasting of Major Flares, Coronal Mass Ejections, and Solar Particle Events from a Proxy of Active-Region Free Magnetic Energy

    Science.gov (United States)

    Barghouty, A. F.; Falconer, D. A.; Adams, J. H., Jr.

    2010-01-01

    This presentation describes a new forecasting tool developed for and is currently being tested by NASA s Space Radiation Analysis Group (SRAG) at JSC, which is responsible for the monitoring and forecasting of radiation exposure levels of astronauts. The new software tool is designed for the empirical forecasting of M and X-class flares, coronal mass ejections, as well as solar energetic particle events. Its algorithm is based on an empirical relationship between the various types of events rates and a proxy of the active region s free magnetic energy, determined from a data set of approx.40,000 active-region magnetograms from approx.1,300 active regions observed by SOHO/MDI that have known histories of flare, coronal mass ejection, and solar energetic particle event production. The new tool automatically extracts each strong-field magnetic areas from an MDI full-disk magnetogram, identifies each as an NOAA active region, and measures a proxy of the active region s free magnetic energy from the extracted magnetogram. For each active region, the empirical relationship is then used to convert the free magnetic energy proxy into an expected event rate. The expected event rate in turn can be readily converted into the probability that the active region will produce such an event in a given forward time window. Descriptions of the datasets, algorithm, and software in addition to sample applications and a validation test are presented. Further development and transition of the new tool in anticipation of SDO/HMI is briefly discussed.

  4. Very high rate programming in primary prevention patients with reduced ejection fraction implanted with a defibrillator: Results from a large multicenter controlled study.

    Science.gov (United States)

    Clementy, Nicolas; Challal, Farid; Marijon, Eloi; Boveda, Serge; Defaye, Pascal; Leclercq, Christophe; Deharo, Jean-Claude; Sadoul, Nicolas; Klug, Didier; Piot, Olivier; Gras, Daniel; Bordachar, Pierre; Algalarrondo, Vincent; Fauchier, Laurent; Babuty, Dominique

    2017-02-01

    Programming implantable cardioverter-defibrillators (ICDs) with a high-rate therapy strategy has proven to be effective in reducing shocks and is associated with a reduced mortality. We sought to determine the impact of a very high rate cutoff programming strategy on outcomes in patients with a primary indication for an ICD due to reduced left ventricular ejection fraction. Using data from the multicenter French DAI-PP registry, this cohort-controlled study compared outcomes in 500 patients programmed with a very high rate cutoff (VH-RATE group: monitor zone 170-219 beats/min; ventricular fibrillation zone ≥220 beats/min with 13 ± 4 detection intervals) with 1500 matched control patients programmed with 1 or 2 therapy zone. All ICDs were implanted for primary prevention in patients with systolic dysfunction. Risks of events were compared after propensity score matching of sex, age, ejection fraction, New York Heart Association class, cardiomyopathy, atrial fibrillation, and type of device. After a mean follow-up of 3.6 ± 2.3 years, VH-RATE programming was associated with a reduction of appropriate therapy risk (hazard ratio [HR] 0.40; 95% confidence interval [CI] 0.31-0.51; P programmed with 2 therapy zones. There was no significant difference in overall survival between the groups. In patients implanted with an ICD in primary prevention with left ventricular dysfunction, very high rate cutoff programming (single therapy zone ≥220 beats/min) was associated with a 60% reduction of appropriate therapies as well as inappropriate shocks, without affecting mortality. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  5. A tool for empirical forecasting of major flares, coronal mass ejections, and solar particle events from a proxy of active-region free magnetic energy

    Science.gov (United States)

    Falconer, David; Barghouty, Abdulnasser F.; Khazanov, Igor; Moore, Ron

    2011-04-01

    This paper describes a new forecasting tool developed for and currently being tested by NASA's Space Radiation Analysis Group (SRAG) at Johnson Space Center, which is responsible for the monitoring and forecasting of radiation exposure levels of astronauts. The new software tool is designed for the empirical forecasting of M- and X-class flares, coronal mass ejections, and solar energetic particle events. For each type of event, the algorithm is based on the empirical relationship between the event rate and a proxy of the active region's free magnetic energy. Each empirical relationship is determined from a data set of ˜40,000 active-region magnetograms from ˜1300 active regions observed by SOHO/Michelson Doppler Imager (MDI) that have known histories of flare, coronal mass ejection, and solar energetic particle event production. The new tool automatically extracts each strong-field magnetic area from an MDI full-disk magnetogram, identifies each as a NOAA active region, and measures the proxy of the active region's free magnetic energy from the extracted magnetogram. For each active region, the empirical relationship is then used to convert the free-magnetic-energy proxy into an expected event rate. The expected event rate in turn can be readily converted into the probability that the active region will produce such an event in a given forward time window. Descriptions of the data sets, algorithm, and software in addition to sample applications and a validation test are presented. Further development and transition of the new tool in anticipation of SDO/HMI are briefly discussed.

  6. COMPOSITION STRUCTURE OF INTERPLANETARY CORONAL MASS EJECTIONS FROM MULTISPACECRAFT OBSERVATIONS, MODELING, AND COMPARISON WITH NUMERICAL SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Reinard, Alysha A. [University of Colorado/Cooperative Institute for Research in Environmental Sciences and National Oceanic and Atmospheric Administration/Space Weather Prediction Center, Boulder, CO 80505 (United States); Lynch, Benjamin J. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Mulligan, Tamitha, E-mail: alysha.reinard@noaa.gov, E-mail: blynch@ssl.berkeley.edu, E-mail: tamitha.mulligan@aero.org [Space Sciences Department, Aerospace Corporation, Los Angeles, CA 90009 (United States)

    2012-12-20

    We present an analysis of the ionic composition of iron for two interplanetary coronal mass ejections (ICMEs) observed on 2007 May 21-23 by the ACE and STEREO spacecraft in the context of the magnetic structure of the ejecta flux rope, sheath region, and surrounding solar wind flow. This analysis is made possible due to recent advances in multispacecraft data interpolation, reconstruction, and visualization as well as results from recent modeling of ionic charge states in MHD simulations of magnetic breakout and flux cancellation coronal mass ejection (CME) initiation. We use these advances to interpret specific features of the ICME plasma composition resulting from the magnetic topology and evolution of the CME. We find that, in both the data and our MHD simulations, the flux ropes centers are relatively cool, while charge state enhancements surround and trail the flux ropes. The magnetic orientations of the ICMEs are suggestive of magnetic breakout-like reconnection during the eruption process, which could explain the spatial location of the observed iron enhancements just outside the traditional flux rope magnetic signatures and between the two ICMEs. Detailed comparisons between the simulations and data were more complicated, but a sharp increase in high iron charge states in the ACE and STEREO-A data during the second flux rope corresponds well to similar features in the flux cancellation results. We discuss the prospects of this integrated in situ data analysis and modeling approach to advancing our understanding of the unified CME-to-ICME evolution.

  7. Comparative Examination of Plasmoid Ejection at Mercury, Earth, Jupiter, and Saturn

    Science.gov (United States)

    Slavin, James A.; Jackman, Caitriona M.; Vogt, Marissa F.

    2011-01-01

    The onset of magnetic reconnection in the near-tail of Earth, long known to herald the fast magnetospheric convection that leads to geomagnetic storms and substorms, is very closely associated with the formation and down-tail ejection of magnetic loops or flux ropes called plasmoids. Plasmoids form as a result of the fragmentation of preexisting cross-tail current sheet as a result of magnetic reconnection. Depending upon the number, location, and intensity of the individual reconnection X-lines and how they evolve, some of these loop-like or helical magnetic structures may also be carried sunward. At the inner edge of the tail they are expected to "re-reconnect' with the planetary magnetic field and dissipate. Plasmoid ejection has now been observed in the magnetotails of Mercury, Earth, Jupiter, and Saturn. These magnetic field and charged particle measurements have been taken by the MESSENGER, Voyager, Galileo, Cassini, and numerous Earth missions. Here we present a comparative examination of the structure and dynamics of plasmoids observed in the magnetotails of these 5 planets. The results are used to learn more about how these magnetic structures form and to assess similarities and differences in the nature of magnetotail reconnection at these planets.

  8. Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction.

    Science.gov (United States)

    Dong, Quan-Li; Wang, Shou-Jun; Lu, Quan-Ming; Huang, Can; Yuan, Da-Wei; Liu, Xun; Lin, Xiao-Xuan; Li, Yu-Tong; Wei, Hui-Gang; Zhong, Jia-Yong; Shi, Jian-Rong; Jiang, Shao-En; Ding, Yong-Kun; Jiang, Bo-Bin; Du, Kai; He, Xian-Tu; Yu, M Y; Liu, C S; Wang, Shui; Tang, Yong-Jian; Zhu, Jian-Qiang; Zhao, Gang; Sheng, Zheng-Ming; Zhang, Jie

    2012-05-25

    Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson et al. [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fanlike electron outflow region including three well-collimated electron jets appears. The (>1 MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS.

  9. Alfvenic Fluctuations in an Interplanetary Coronal Mass Ejection Observed Near 1 AU

    Institute of Scientific and Technical Information of China (English)

    梁浩明; 肖池阶; 周桂萍; 濮祖荫; 王红刚; 王晓钢

    2012-01-01

    As for the present situation of coronal mass ejection (CME) triggering models, the distributions of Alfv@n waves in flux ropes are different from model to model, and thus examining those distributions in interplanetary coronal mass ejection (ICME) is an effective way to connect ICME observations with these theoretical models of CME triggering. However, previous observations of Alfv@nic fluctuations in ICMEs were rare with locations ranging from 0.3 AU to 0.68 AU only, which is usually explained as rapid dissipation of those remnant waves. Here we present an observation of Alfv@n waves in a magnetic cloud (MC) near 1 AU, in situ detected by WIND in February 17,-~20, 2011. The MC was generated by a CME accompanied with the first X-class flare in the 24th solar cycle. The slope of the power spectral densities of magnetic fluctuation in the MC, are similar to those modes in ambient solar wind, but more anisotropic. The results will also be helpful for studies of CME theories and ICME thermodynamics.

  10. On the nature of an ejection event in the jet of 3C111

    CERN Document Server

    Perucho, M; Gómez, J L; Kadler, M; Ros, E; Kovalev, Y Y

    2008-01-01

    We present a possible scenario for the ejection of a superluminal component in the jet of the Broad Line Radio Galaxy 3C111 in early 1996. VLBI observations at 15 GHz discovered the presence of two jet features on scales smaller than one parsec. The first component evolves downstream, whereas the second one fades out after 1 parsec. We propose the injection of a perturbation of dense material followed by a decrease in the injection rate of material in the jet as a plausible explanation. This scenario is supported by 1D relativistic hydrodynamics and emission simulations. The perturbation is modeled as an increase in the jet density, without modifying the original Lorentz factor in the initial conditions. We show that an increase of the Lorentz factor in the material of the perturbation fails to reproduce the observed evolution of this flare. We are able to estimate the lifetime of the ejection event in 3C111 to be 36\\pm7 days.

  11. Deflections of Fast Coronal Mass Ejections and the Properties of Associated Solar Energetic Particle Events

    Science.gov (United States)

    Kahler, S. W.; Akiyama, S.; Gopalswamy, N.

    2012-01-01

    The onset times and peak intensities of solar energetic particle (SEP) events at Earth have long been thought to be influenced by the open magnetic fields of coronal holes (CHs). The original idea was that a CH lying between the solar SEP source region and the magnetic footpoint of the 1 AU observer would result in a delay in onset and/or a decrease in the peak intensity of that SEP event. Recently, Gopalswamy et al. showed that CHs near coronal mass ejection (CME) source regions can deflect fast CMEs from their expected trajectories in space, explaining the appearance of driverless shocks at 1 AU from CMEs ejected near solar central meridian (CM). This suggests that SEP events originating in CME-driven shocks may show variations attributable to CH deflections of the CME trajectories. Here, we use a CH magnetic force parameter to examine possible effects of CHs on the timing and intensities of 41 observed gradual E approx 20 MeV SEP events with CME source regions within 20 deg. of CM. We find no systematic CH effects on SEP event intensity profiles. Furthermore, we find no correlation between the CME leading-edge measured position angles and SEP event properties, suggesting that the widths of CME-driven shock sources of the SEPs are much larger than the CMEs. Independently of the SEP event properties, we do find evidence for significant CME deflections by CH fields in these events

  12. Heart failure with preserved ejection fraction in the elderly: scope of the problem.

    Science.gov (United States)

    Upadhya, Bharathi; Taffet, George E; Cheng, Che Ping; Kitzman, Dalane W

    2015-06-01

    Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure (HF) in older adults, particularly women, and is increasing in prevalence as the population ages. With morbidity and mortality on par with HF with reduced ejection fraction, it remains a most challenging clinical syndrome for the practicing clinician and basic research scientist. Originally considered to be predominantly caused by diastolic dysfunction, more recent insights indicate that HFpEF in older persons is typified by a broad range of cardiac and non-cardiac abnormalities and reduced reserve capacity in multiple organ systems. The globally reduced reserve capacity is driven by: 1) inherent age-related changes; 2) multiple, concomitant co-morbidities; 3) HFpEF itself, which is likely a systemic disorder. These insights help explain why: 1) co-morbidities are among the strongest predictors of outcomes; 2) approximately 50% of clinical events in HFpEF patients are non-cardiovascular; 3) clinical drug trials in HFpEF have been negative on their primary outcomes. Embracing HFpEF as a true geriatric syndrome, with complex, multi-factorial pathophysiology and clinical heterogeneity could provide new mechanistic insights and opportunities for progress in management. This article is part of a Special Issue entitled CV Aging. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Diastolic relaxation and compliance reserve during dynamic exercise in heart failure with preserved ejection fraction.

    Science.gov (United States)

    Borlaug, Barry A; Jaber, Wissam A; Ommen, Steve R; Lam, Carolyn S P; Redfield, Margaret M; Nishimura, Rick A

    2011-06-01

    Recent studies have examined haemodynamic changes with stressors such as isometric handgrip and rapid atrial pacing in heart failure with preserved ejection fraction (HFpEF), but little is known regarding left ventricular (LV) pressure-volume responses during dynamic exercise. To assess LV haemodynamic responses to dynamic exercise in patients with HFpEF. Twenty subjects with normal ejection fraction (EF) and exertional dyspnoea underwent invasive haemodynamic assessment during dynamic exercise to evaluate suspected HFpEF. LV end-diastolic pressure was elevated at rest (>15 mm Hg, n=18) and with exercise (≥20 mm Hg, n=20) in all subjects, consistent with HFpEF. Heart rate (HR), blood pressure, arterial elastance and cardiac output increased with exercise (all pincreased by 43-56% with exercise (both pincreases in HR and the proportion of diastole that elapsed prior to estimated complete relaxation increased (pincreased 50% during exercise (p=0.0003). Exercise increases in LV filling pressures correlated with changes in diastolic relaxation rates, chamber stiffness and arterial afterload but were not related to alterations in preload volume, HR or cardiac output. In patients with newly diagnosed HFpEF, LV filling pressures increase during dynamic exercise in association with inadequate enhancement of relaxation and acute increases in LV chamber stiffness. Therapies that enhance diastolic reserve function may improve symptoms of exertional intolerance in patients with hypertensive heart disease and early HFpEF.

  14. On the autonomous detection of coronal mass ejections in heliospheric imager data

    Science.gov (United States)

    Tappin, S. J.; Howard, T. A.; Hampson, M. M.; Thompson, R. N.; Burns, C. E.

    2012-05-01

    We report on the development of an Automatic Coronal Mass Ejection (CME) Detection tool (AICMED) for the Solar Mass Ejection Imager (SMEI). CMEs observed with heliospheric imagers are much more difficult to detect than those observed by coronagraphs as they have a lower contrast compared with the background light, have a larger range of intensity variation and are easily confused with other transient activity. CMEs appear in SMEI images as very faint often-fragmented arcs amongst a much brighter and often variable background. AICMED operates along the same lines as Computer Aided CME Tracking (CACTus), using the Hough Transform on elongation-time J-maps to extract straight lines from the data set. We compare AICMED results with manually measured CMEs on almost three years of data from early in SMEI operations. AICMED identified 83 verifiable events. Of these 46 could be matched with manually identified events, the majority of the non-detections can be explained. The remaining 37 AICMED events were newly discovered CMEs. The proportion of false identification was high, at 71% of the autonomously detected events. We find that AICMED is very effective as a region of interest highlighter, and is a promising first step in autonomous heliospheric imager CME detection, but the SMEI data are too noisy for the tool to be completely automated.

  15. Experimental-calculation simulation of the ejection of particles from a shock-loaded surface

    Science.gov (United States)

    Mikhailov, A. L.; Ogorodnikov, V. A.; Sasik, V. S.; Raevskii, V. A.; Lebedev, A. I.; Zotov, D. E.; Erunov, S. V.; Syrunin, M. A.; Sadunov, V. D.; Nevmerzhitskii, N. V.; Lobastov, S. A.; Burtsev, V. V.; Mishanov, A. V.; Kulakov, E. V.; Satarova, A. V.; Georgievskaya, A. B.; Knyazev, V. N.; Kleshchevnikov, O. A.; Antipov, M. V.; Glushikhin, V. V.; Yurtov, I. V.; Utenkov, A. A.; Sen'kovskii, E. D.; Abakumov, S. A.; Presnyakov, D. V.; Kalashnik, I. A.; Panov, K. N.; Arinin, V. A.; Tkachenko, B. I.; Filyaev, V. N.; Chapaev, A. V.; Andramanov, A. V.; Lebedeva, M. O.; Igonin, V. V.

    2014-05-01

    The possibilities of measuring complex Pylenie, which is intended for studying the parameters of the particles ejected from the free surface of a shock-loaded material and was created at the Institute of Experimental Gas Dynamics and Detonation Physics RFNC-VNIIEF, are demonstrated. The operation of the complex is based on the following three methods, which are based on different physical principles and supplement each other: laser-optical method (macro- and microfilming), pulsed X-ray method, and piezoelectric pressure sensors. This complex is used to study the ejection of particles from the free surface of lead samples when a shock wave with a pressure of 7, 16, and 23 GPa at its front reaches this surface. The effect of the surface roughness and the pressure amplitude at the shock wave front on the quantitative characteristics of the process is shown. The calculation-theoretical simulation is performed by two-dimensional numerical calculations of gasdynamic flows, and the calculation results are used to estimate the "ejecta" characteristics in terms of the developed phenomenological model of the process.

  16. Time-Dependent Regional Myocardial Strains in Patients with Heart Failure with a Preserved Ejection Fraction

    Directory of Open Access Journals (Sweden)

    Shane P. Smith

    2016-01-01

    Full Text Available Objectives. To better understand the etiology of HFpEF in a controlled human population, regional time-varying strains were computed using echocardiography speckle tracking in patients with heart failure with a preserved ejection fraction and normal subjects. Methods. Eleven normal volunteers and ten patients with echo-graded diastolic dysfunction and symptoms of heart failure were imaged with echocardiography and longitudinal, circumferential, and rotational strains were determined using speckle-tracking. Diastolic strain rate was also determined. Patient demographics and echo-derived flows, volumes, and pressures were recorded. Results. Peak longitudinal and circumferential strain was globally reduced in patients (p<0.001, when compared to controls. The patients attained peak longitudinal and circumferential strain at a consistently later point in systole than controls. Rotational strains were not different in most LV regions. Early diastolic strain rate was significantly reduced in the patients (p<0.001. LV mass and wall thickness were significantly increased in the patients; however ejection fraction was preserved and stroke volume was diminished (p<0.001. Conclusions. This study shows that patients with HFpEF have reduced early diastolic strain rate and reduced peak strain that is regionally homogeneous and that they also utilize a longer fraction of systole to achieve peak axial strains.

  17. How do patients with heart failure with preserved ejection fraction die?

    Science.gov (United States)

    Chan, Michelle M Y; Lam, Carolyn S P

    2013-06-01

    Understanding how patients with heart failure with preserved ejection fraction (HFPEF) die provides insight into the natural history and pathophysiology of this complex syndrome, thereby allowing better prediction of response to therapy in designing clinical trials. This review summarizes the current state of knowledge surrounding mortality rates, modes of death, and prognostic factors in HFPEF. Despite the lack of uniform reporting, the following conclusions may be drawn from previous studies. The mortality burden of HFPEF is substantial, ranging from 10% to 30% annually, and higher in epidemiological studies than in clinical trials. Mortality rates compared with heart failure with reduced ejection fraction (HFREF) appear to be strongly influenced by the type of study, but are clearly elevated compared with age- and co-morbidity-matched controls without heart failure. The majority of deaths in HFPEF are cardiovascular deaths, comprising 51-60% of deaths in epidemiological studies and ∼70% in clinical trials. Among cardiovascular deaths, sudden death and heart failure death are the leading cardiac modes of death in HFPEF clinical trials. Compared with HFREF, the proportions of cardiovascular deaths, sudden death, and heart failure deaths are lower in HFPEF. Conversely, non-cardiovascular deaths constitute a higher proportion of deaths in HFPEF than in HFREF, particularly in epidemiological studies, where this difference may be related to fewer coronary heart deaths in HFPEF. Key mortality risk factors, including age, gender, body mass index, burden of co-morbidities, and coronary artery disease, offer some explanation for the differences in mortality rates observed across studies.

  18. RADIAL AND AZIMUTHAL OSCILLATIONS OF HALO CORONAL MASS EJECTIONS IN THE SUN

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Harim; Moon, Y.-J.; Nakariakov, V. M., E-mail: harim@khu.ac.kr, E-mail: moonyj@khu.ac.kr, E-mail: V.Nakariakov@warwick.ac.uk [School of Space Research, Kyung Hee University, Yongin 446-701 (Korea, Republic of)

    2015-04-10

    We present the first observational detection of radial and azimuthal oscillations in full halo coronal mass ejections (HCMEs). We analyze nine HCMEs well-observed by the Large Angle and Spectrometric Coronagraph (LASCO) from 2011 February to June. Using the LASCO C3 running difference images, we estimated the instantaneous apparent speeds of the HCMEs in different radial directions from the solar disk center. We find that the development of all these HCMEs is accompanied by quasi-periodic variations of the instantaneous radial velocity with the periods ranging from 24 to 48 minutes. The amplitudes of the instant speed variations reach about a half of the projected speeds. The amplitudes are found to anti-correlate with the periods and correlate with the HCME speed, indicating the nonlinear nature of the process. The oscillations have a clear azimuthal structure in the heliocentric polar coordinate system. The oscillations in seven events are found to be associated with distinct azimuthal wave modes with the azimuthal wave number m = 1 for six events and m = 2 for one event. The polarization of the oscillations in these seven HCMEs is broadly consistent with those of their position angles with the mean difference of 43°. The oscillations may be connected with natural oscillations of the plasmoids around a dynamical equilibrium, or self-oscillatory processes, e.g., the periodic shedding of Alfvénic vortices. Our results indicate the need for an advanced theory of oscillatory processes in coronal mass ejections.

  19. Puddle jumping: Spontaneous ejection of large liquid droplets from hydrophobic surfaces during drop tower tests

    Science.gov (United States)

    Attari, B.; Weislogel, M.; Wollman, A.; Chen, Y.; Snyder, T.

    2016-10-01

    Large droplets and puddles jump spontaneously from sufficiently hydrophobic surfaces during routine drop tower tests. The simple low-cost passive mechanism can in turn be used as an experimental device to investigate dynamic droplet phenomena for drops up to 104 times larger than their normal terrestrial counterparts. We provide and/or confirm quick and qualitative design guides for such "drop shooters" as employed in drop tower tests including relationships to predict droplet ejection durations and velocities as functions of drop volume, surface texture, surface contour, wettability pattern, and fluid properties including contact angle. The latter is determined via profile image comparisons with numerical equilibrium interface computations. Water drop volumes of 0.04-400 ml at ejection speeds of -0.007-0.12 m/s are demonstrated herein. A sample application of the drop jump method is made to the classic problem of low-gravity phase change heat transfer for large impinging drops. Many other candidate problems might be identified by the reader.

  20. Facts and numbers on epidemiology and pharmacological treatment of heart failure with preserved ejection fraction.

    Science.gov (United States)

    Edelmann, Frank

    2015-06-01

    Heart failure with preserved ejection fraction (HFpEF) is a major and growing public health problem. Epidemiologic studies demonstrated that heart failure (HF) can be clinically diagnosed in patients with normal or preserved left ventricular ejection fraction. These patients are therefore termed as having HFpEF. In the past, this was often called diastolic HF. Because of the permanent increase of the prevalence of HFpEF during the past decades, HFpEF now accounts for more than 50% of the total HF population. There are uncertainties and debates regarding the definition, diagnosis, and pathophysiology with the consequence that all outcome trials performed so far used criteria for inclusion and exclusion that were not consistent. These trials also failed to document improved prognosis. Recent smaller proof-of-concept or Phase II clinical trials investigating different pathophysiological approaches with substances such as the neprilysin inhibitor-angiotensin receptor blocker- combination (LCZ 696), ranolazine, or ivabradine were successful to improve biomarkers, haemodynamics, or functional capacity. Future trials will need to document whether also prognosis can be improved.

  1. A Unified Bond Graph Modeling Approach for the Ejection Phase of the Cardiovascular System

    Directory of Open Access Journals (Sweden)

    LUBNA MOIN

    2016-07-01

    Full Text Available In this paper the unified Bond Graph model of the left ventricle ejection phase is presented, simulated and validated. The integro-differential and ordinary differential equations obtained from the bond graph models are simulated using ODE45 (Ordinary Differential Equation Solver on MATLAB and Simulink. The results, thus, obtained are compared with CVS (Cardiovascular System physiological data present in Simbiosys (a software for simulating biological systems and also with the CVS Wiggers diagram of heart cycle. As the cardiac activity is a multi domain process that includes mechanical, hydraulic, chemical and electrical events; therefore, for modeling such systems a unified modeling approach is needed. In this paper the unified Bond Graph model of the left ventricle ejection phase is proposed. The Bond Graph conventionalism approach is a graphical method principally powerful to portray multi-energy systems, as it is formulated on the portrayal of power exchanges. The model takes into account a simplified description of the left ventricle which is close to the medical investigation promoting the apperception and the dialogue between engineers and physiologists.

  2. OBSERVATION OF HEATING BY FLARE-ACCELERATED ELECTRONS IN A SOLAR CORONAL MASS EJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Glesener, Lindsay; Bain, Hazel M. [Space Sciences Laboratory, University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Krucker, Säm [Also at Institute of 4-D Technologies, School of Engineering, University of Applied Sciences Northwestern Switzerland, 5210 Windisch, Switzerland. (Switzerland); Lin, Robert P., E-mail: glesener@ssl.berkeley.edu [Also at Physics Department, University of California at Berkeley, Berkeley, CA 94720, USA. (United States)

    2013-12-20

    We report a Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observation of flare-accelerated electrons in the core of a coronal mass ejection (CME) and examine their role in heating the CME. Previous CME observations have revealed remarkably high thermal energies that can far surpass the CME's kinetic energy. A joint observation by RHESSI and the Atmospheric Imaging Assembly of a partly occulted flare on 2010 November 3 allows us to test the hypothesis that this excess energy is collisionally deposited by flare-accelerated electrons. Extreme ultraviolet (EUV) images show an ejection forming the CME core and sheath, with isothermal multifilter analysis revealing temperatures of ∼11 MK in the core. RHESSI images reveal a large (∼100 × 50 arcsec{sup 2}) hard X-ray (HXR) source matching the location, shape, and evolution of the EUV plasma, indicating that the emerging CME is filled with flare-accelerated electrons. The time derivative of the EUV emission matches the HXR light curve (similar to the Neupert effect observed in soft and HXR time profiles), directly linking the CME temperature increase with the nonthermal electron energy loss, while HXR spectroscopy demonstrates that the nonthermal electrons contain enough energy to heat the CME. This is the most direct observation to date of flare-accelerated electrons heating a CME, emphasizing the close relationship of the two in solar eruptive events.

  3. Galaxy evolution near groups and clusters: ejected satellites and the spatial extent of environmental quenching

    CERN Document Server

    Wetzel, Andrew R; Conroy, Charlie; Bosch, Frank C van den

    2013-01-01

    While satellite galaxies within groups/clusters are more likely to exhibit quiescent star formation rates (SFR) than central (field) galaxies, an enhanced quiescent likelihood extends to galaxies that are several virial radii beyond groups/clusters. Using a galaxy group/cluster catalog from SDSS DR7, we show that this enhancement has two causes. First, massive halos are clustered, so neighboring halos that host their own satellite galaxies boost the observed quiescent fraction out to large distances. Second, and more interestingly, central galaxies exhibit a strongly enhanced quiescent fraction out to 2.5 virial radii (with some enhancement out to 5 virial radii) beyond groups/clusters. We show that this enhancement for central galaxies can be explained by 'ejected' satellite galaxies that orbit beyond their host halo's virial radius. Using a cosmological N-body simulation, we examine the orbital histories of ejected satellites, showing that they extend out to 2.5 virial radii beyond their host halo and compo...

  4. Losses of Energetic Electrons in Earth's Outer Radiation Belt During Unusual Coronal Mass Ejections

    Science.gov (United States)

    Lugaz, Noé; Huang, Chia-Lin; Schwadron, Nathan; Spence, Harlan; Farrugia, Charles; Winslow, Reka

    2016-07-01

    The most extreme changes in solar wind parameters important for the coupling between the solar wind and the magnetosphere (dynamic pressure, dawn-to-dusk electric field, Alfven Mach number, plasma beta, …) occur during the passage at Earth of coronal mass ejections (CMEs). While the response of Earth's radiation belts to CMEs and CME-driven shocks has been investigated in great details, few studies have focused on what makes some CMEs and their shocks especially effective in driving losses of energetic electrons in the outer radiation belt. Here, we present specific examples of losses during the passage at Earth of a coronal mass ejection. In particular, we discuss the conditions which may result in the magnetopause to retreat earthward up to geosynchronous orbit, resulting in significant losses of energetic electrons due to magnetopause shadowing. We also present the result of a low-density magnetic ejecta which impacted Earth in January 2013. Combining interplanetary, magnetosheath, outer magnetosphere and radiation belt measurements by more than ten satellites, including the Van Allen Probes, THEMIS and Cluster, we show how a period of extremely low Mach number and dynamic pressure during the passage of the magnetic cloud resulted in dramatic losses in the outer radiation belt and a large-scale reorganization of the entire day-side magnetosphere.

  5. Evaluation of postoperative cardiac function in severe ischemic heart disease associated with decreased ejection fraction

    Energy Technology Data Exchange (ETDEWEB)

    Natsuaki, Masafumi; Itoh, Tsuyoshi; Norita, Hiroaki; Naitoh, Kouzou; Suda, Hisao [Saga Medical School (Japan)

    1997-09-01

    This clinical study was performed to clarify the postoperative cardiac functions after coronary artery bypass graft surgery in the cases associated with decreased left ventricular ejection fraction (EF) or increased end-diastolic volume index (EDVI). The patients were divided into two groups by preoperative EF. The EF of Group I ranged from 31 to 39% in 42 cases, and the EF of Group II was below 30% in 27 cases. Several parameters of cardiac function such as EF, peak ejection rate (PER), peak filling rate (PFR) or early diastolic peak filling rate were evaluated with radionuclide ventriculography. Postoperative mean values of these parameters significantly improved in both Group I and Group II compared to preoperative values. Although these parameters and left ventricular wall motion did not improve in the 7 cases with an EDVI over 140 ml/m{sup 2} in Group II, the clinical results of these 7 cases were good during the follow-up period except one case which preoperatively had frequent ventricular arrythmia. The clinical condition improved remarkably in the 3 patients who had preoperative angina pectoris among these 7 cases. Surgical indications must be carefully determined in cases with increased EDVI and frequent ventricular arrythmia. (author)

  6. The spectroscopic imprint of the pre-eruptive configuration resulting into two major coronal mass ejections

    CERN Document Server

    Syntelis, Petros; Patsourakos, Spiros; Tsinganos, Kanaris

    2016-01-01

    We present a spectroscopic analysis of the pre-eruptive configuration of active region NOAA 11429, prior to two very fast coronal mass ejections (CMEs) on March 7, 2012 that are associated with this active region. We study the thermal components and the dynamics associated with the ejected flux ropes. Using differential emission measure (DEM) analysis of Hinode/EIS and SDO/AIA observations, we identify the emission components of both the flux rope and the host active region. We then follow the time evolution of the flux rope emission components by using AIA observations. The plasma density and the Doppler and non-thermal velocities associated with the flux ropes are also calculated from the EIS data. The eastern and western parts of the active region, in which the two different fast CMEs originated during two X-class flares, were studied separately. In both regions we identified an emission component in the temperature range of $\\log T=6.8 - 7.1$ associated with the presence of flux ropes. The time evolution ...

  7. Ejected-electron spectroscopy of autoionizing resonances of helium excited by fast-electron impact

    Science.gov (United States)

    Zhang, Zhe; Shan, Xu; Wang, Enliang; Chen, Xiangjun

    2012-06-01

    The autoionizing resonances (2s2)1S, (2p2)1D, and (2s2p)1P of helium have been investigated employing ejected-electron spectroscopy by fast-electron impact at incident energies of 250-2000 eV and ejected angles of 26°-116°. Shore parameters of the line shapes for these three resonances have been obtained in such high incident energy regime except at 250 eV. Distinct discrepancies between the present results at 250 eV and those of McDonald and Crowe at 200 eV [D. G. McDonald and A. Crowe, J. Phys. BJPAMA40953-407510.1088/0953-4075/25/9/018 25, 2129 (1992); D. G. McDonald and A. Crowe, J. Phys. BJPAMA40953-407510.1088/0953-4075/25/20/024 25, 4313 (1992)] and Sise at 250 eV [O. Sise, M. Dogan, I. Okur, and A. Crowe, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.84.022705 84, 022705 (2011)], especially for 1D and 1P states, are also observed.

  8. NEW EMPHASES ON THE STUDY OF THE PATHOGENESIS OF CHRONIC HEART FAILURE WITH PRESERVED EJECTION FRACTION: FOCUS ON INFLAMMATORY MARKERS

    Directory of Open Access Journals (Sweden)

    O. M. Drapkina

    2014-01-01

    Full Text Available For the long time the systolic myocardial dysfunction was traditionally associated with the severity of chronic heart failure (CHF. Increasing number of patients with symptoms of CHF but without systolic dysfunction has drawn the attention of specialists to so-called CHF with preserved ejection fraction. Prognosis in CHF with preserved ejection fraction may be as bad as in CHF with reduced ejection fraction. Significant changes in views on the pathogenesis of CHF led to the creation of new therapeutic approaches in the treatment of this disease. However, at present, convincing evidence base of mortality reduction in patients with CHF with preserved ejection fraction using well-known therapeutic agents is unavailable. It makes conduct active searches for new biological markers of diastolic heart function. Participation of proinflammatory cytokines, in particular GDF-15, in the process of elasticity reduction and relaxation disorders of left ventricular myocardium, may be of great importance in the development of new medical agents designed to delay the progression of CHF with preserved ejection fraction.

  9. Geoeffectiveness (D (sub st) and K (sub p)) of Interplanetary Coronal Mass Ejections During 1995-2009 and Implications for Storm Forecasting

    Science.gov (United States)

    Richardson, I. G.; Cane, H. V.

    2011-01-01

    We summarize the geoeffectiveness (based on the Dst and Kp indices) of the more than 300 interplanetary coronal mass ejections (ICMEs) that passed the Earth during 1996-2009, encompassing solar cycle 23. We subsequently estimate the probability that an ICME will generate geomagnetic activity that exceeds certain thresholds of Dst or Kp, including the NOAA "G" storm scale, based on maximum values of the southward magnetic field component (Bs), the solar wind speed (V), and the y component (Ey) of the solar wind convective electric field E = -V x B, in the ICME or sheath ahead of the ICME. Consistent with previous studies, the geoeffectiveness of an ICME is correlated with Bs or Ey approx.= VBs in the ICME or sheath, indicating that observations from a solar wind monitor upstream of the Earth are likely to provide the most reliable forecasts of the activity associated with an approaching ICME. There is also a general increase in geoeffectiveness with ICME speed, though the overall event-to-event correlation is weaker than for Bs and Ey. Nevertheless, using these results, we suggest that the speed of an ICME approaching the Earth inferred, for example, from routine remote sensing by coronagraphs on spacecraft well separated from the Earth or by all-sky imagers, could be used to estimate the likely geoeffectiveness of the ICME (our "comprehensive" ICME database provides a proxy for ICMEs identified in this way) with a longer lead time than may be possible using an upstream monitor

  10. X-ray Dips Followed by Superluminal Ejections as Evidence for An Accretion Disc Feeding the Jet in A Radio Galaxy

    Science.gov (United States)

    Marscher, Alan P.; Jorstad, Svetlana G.; Gomez, Jose-Luis; Aller, Margo F.; Terasranta, Harri; Lister, Matthew L.; Stirling, Alastair, M.

    2002-01-01

    Accretion onto black holes is thought to power the relativistic jets and other high-energy phenomena in both active galactic nuclei (AGNs) and the "microquasar" binary systems located in our Galaxy. However, until now there has been insufficient multifrequency monitoring to establish a direct observational link between the black hole and the jet in an AGE. This contrasts with the case of microquasars, in which superluminal features appear and propagate down the radio jet shortly after sudden decreases in the X-ray flux. Such an X-ray dip is most likely caused by the disappearance of a section of the inner accretion disc, part of which falls past the event horizon and the remainder of which is injected into the jet. This infusion of energy generates a disturbance that propagates down the jet, creating the appearance of a superluminal bright spot. Here we report the results of three years of intensive monitoring of the X-ray and radio emission of the Seyfert-like radio galaxy 3C 120. As in the case of microquasars, dips in the X-ray emission are followed by ejections of bright superluminal knots in the radio jet. Comparison of the characteristic length and time scales allows us to infer that the rotational states of the black holes in these two objects are different.

  11. Monitoring madness

    Energy Technology Data Exchange (ETDEWEB)

    Blankinship, S.

    2006-01-15

    High quality continuous emission monitoring capability can be as essential as high quality emission control equipment. Future mercury monitoring and control requirements add to the justification for better CEMS. The article discusses two prominent mercury measurement methods - the cold vapour atomic absorptive spectrometer (CVAAs) and the atomic absorptive spectrometer (AFS). It stresses the importance of maintaining a CEMS. 1 photo.

  12. Mobility Monitor

    DEFF Research Database (Denmark)

    Schæbel, Anne-Lise; Dybbro, Karina Løvendahl; Andersen, Lisbeth Støvring;

    2015-01-01

    Undersøgelse af digital monitorering af plejehjemsbeboeres vendinger under søvn på Fremtidens Plejehjem, Nørresundby......Undersøgelse af digital monitorering af plejehjemsbeboeres vendinger under søvn på Fremtidens Plejehjem, Nørresundby...

  13. Numerical simulation of ejected molten metal-nanoparticles liquefied by laser irradiation: Interplay of geometry and dewetting

    CERN Document Server

    Afkhami, S

    2013-01-01

    Metallic nanoparticles, liquefied by fast laser irradiation, go through a rapid change of shape attempting to minimize their surface energy. The resulting nanodrops may be ejected from the substrate when the mechanisms leading to dewetting are sufficiently strong, as in the experiments involving gold nanoparticles [Habenicht et al., Science 309, 2043 (2005)]. We use a direct continuum-level approach to accurately model the process of liquid nanodrop formation and the subsequent ejection from the substrate. Our computations show a significant role of inertial effects and an elaborate interplay of initial geometry and wetting properties: e.g., we can control the direction of ejection by prescribing appropriate initial shape and/or wetting properties. We validate our computations by comparing directly with the experiments specified above involving the length scales measured in hundreds of nanometers, and with molecular dynamics simulations on much shorter scales measured in tens of atomic diameters, as in M. Fue...

  14. Biomechanical investigation of thoracolumbar spine in different postures during ejection using a combined finite element and multi-body approach.

    Science.gov (United States)

    Du, Chengfei; Mo, Zhongjun; Tian, Shan; Wang, Lizhen; Fan, Jie; Liu, Songyang; Fan, Yubo

    2014-11-01

    The aim of this study is to investigate the dynamic response of a multi-segment model of the thoracolumbar spine and determine how the sitting posture affects the response under the impact of ejection. A nonlinear finite element model of the thoracolumbar-pelvis complex (T9-S1) was developed and validated. A multi-body dynamic model of a pilot was also constructed so an ejection seat restraint system could be incorporated into the finite element model. The distribution of trunk mass on each vertebra was also considered in the model. Dynamics analysis showed that ejection impact induced obvious axial compression and anterior flexion of the spine, which may contribute to spinal injuries. Compared with a normal posture, the relaxed posture led to an increase in stress on the cortical wall, endplate, and intradiscal pressure of 43%, 10%, 13%, respectively, and accordingly increased the risk of inducing spinal injuries. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Accretion and ejection in black-hole X-ray transients

    Science.gov (United States)

    Kylafis, N. D.; Belloni, T. M.

    2015-02-01

    Context. A rich phenomenology has been accumulated over the years regarding accretion and ejection in black-hole X-ray transients (BHTs) and it needs an interpretation. Aims: Here we summarize the current observational picture of the outbursts of BHTs, based on the evolution traced in a hardness-luminosity diagram (HLD), and we offer a physical interpretation. Methods: The basic ingredient in our interpretation is the Poynting-Robertson cosmic battery (PRCB), which provides locally the poloidal magnetic field needed for the ejection of the jet. In addition, we make two assumptions, easily justifiable. The first is that the mass-accretion rate to the black hole in a BHT outburst has a generic bell-shaped form, whose characteristic time scale is much longer than the dynamical or the cooling ones. This is guaranteed by the observational fact that all BHTs start their outburst and end it at the quiescent state, i.e., at very low accretion rate, and that state transitions take place over long time scales (hours to days). The second assumption is that at low accretion rates the accretion flow is geometrically thick, ADAF-like, while at high accretion rates it is geometrically thin. Last, but not least, we demonstrate that the previous history of the system is absolutely necessary for the interpretation of the HLD. Results: Both, at the beginning and the end of an outburst, the PRCB establishes a strong poloidal magnetic field in the ADAF-like part of the accretion flow, and this explains naturally why a jet is always present in the right part of the HLD. In the left part of the HLD, the accretion flow is in the form of a thin disk, and such a disk cannot sustain a strong poloidal magnetic filed. Thus, no jet is expected in this part of the HLD. Finally, the counterclockwise traversal of the HLD is explained as follows: all outbursts start from the quiescent state, in which the inner part of the accretion flow is ADAF-like, threaded by a poloidal magnetic field. As the

  16. Factors influencing the variations of ejection fraction during exercise in chronic aortic regurgitation

    Energy Technology Data Exchange (ETDEWEB)

    Bassand, J.P.; Faivre, R.; Berthout, P.; Maurat, J.P.; Cardot, J.C.; Verdenet, J.; Bidet, R.

    1987-11-01

    The influence of left ventricular volume variations and regurgitant fraction variations upon left ventricular ejection fraction during exercise was examined using equilibrium radionuclide angiography in patients suffering from aortic regurgitation. Ejection fraction (EF), regurgitant fraction (RF), end diastolic volume (EDV) and end systolic volume (ESV) variations from rest to peak exercise were determined in 44 patients suffering from chronic aortic regurgitation (AR) and in 8 healthy volunteers (C). In C, EF increased (+0.10+-0.03, P<0.01) and ESV decreased significantly (-23%+-12%, P<0.01), RF and EDV did not vary significantly. In AR patients, EF, EDV and ESV did not vary significantly because of important scattering of individual values. Changes in EF and ESV were inversely correlated (r=-0.79, P<0.01) and RF decreased significantly (-0.12+-0.10, P<0.01). Volumes and EF changes during exercise occurred in three different ways. In a 1st subgroup of 7 patients, EF increased (+0.09+-0.03, P<0.05) in conjunction with a reduction of ESV (-24%+-12%, P<0.05) without a significant change in EDV. In a 2nd group of 22 patients, EF decreased (-0.04+-0.07, P<0.01) in association with an increase in ESV (+17%+-16%, P<0.01) and no changes in EDV. In a 3rd subgroup of 15 patients, EF decreased (-0.02+-0.06, P<0.01) despite a reduction in ESV (-7%+-6%, P<0.01) because of a dramatic EDV decrease (-10%+-6%, P<0.05). In this subgroup, changes in EF were inversely correlated with changes in ESV (r=-0.55, P<0.01) and positively related to EDV variations (r=0.42, P=0.02). EDV changes were weakly, but significantly, correlated to RF decrease (r=0.39, P<0.05). We conclude that changes in left ventricular ejection fraction during exercise in patients with chronic aortic regurgitation are significantly related in some patients to changes in ventricular loading conditions as well as contractile state.

  17. Monitoring Space Disturbances using KACST MWC detector

    Science.gov (United States)

    Maghrabi, Abdullrahman; Alenizi, Mohammed; Almuteri, Mohammed; AlDosari, Abdullah; Alshehri, Abdullah

    2016-04-01

    Forbush decreases are short term variations in cosmic ray observations due to the solar transient events such as solar flares and coronal mass ejections which affect the interplanetary field and heliospheric structure. They are defined as a sharp reduction of cosmic ray intensity followed by a gradual recovery over a period of a few days. We have constructed and operated a three layer small MultiWire Proportional Chamber (MWPC) for cosmic ray muon monitoring. The detector is located at KACST radiation detector laboratory (769 m; Rc=14.4 GV), Riyadh, Saudi Arabia. In this paper, data from this newly developed detector were used to study FD observed during 5-30 December 2015. Interplanetary data were used to characterize the solar and interplanetary conditions causing the observed FD. The obtained results were comparable with those obtained by the existed 1 m2 scintillator detector and with data obtained from different neutron monitors around the world.

  18. Composition Structure of Interplanetary Coronal Mass Ejections From Multispacecraft Observations, Modeling, and Comparison with Numerical Simulations

    CERN Document Server

    Reinard, Alysha; Mulligan, Tamitha

    2012-01-01

    We present an analysis of the ionic composition of iron for two interplanetary coronal mass ejections observed in May 21-23 2007 by the ACE and STEREO spacecraft in the context of the magnetic structure of the ejecta flux rope, sheath region, and surrounding solar wind flow. This analysis is made possible due to recent advances in multispacecraft data interpolation, reconstruction, and visualization as well as results from recent modeling of ionic charge states in MHD simulations of magnetic breakout and flux cancellation CME initiation. We use these advances to interpret specific features of the ICME plasma composition resulting from the magnetic topology and evolution of the CME. We find that in both the data and our MHD simulations, the flux ropes centers are relatively cool, while charge state enhancements surround and trail the flux ropes. The magnetic orientation of the ICMEs are suggestive of magnetic breakout-like reconnection during the eruption process which could explain the spatial location of the...

  19. Observing the Unobservable: identification and Characterization of Stealth Coronal Mass Ejections

    Science.gov (United States)

    D'Huys, Elke

    2016-01-01

    In this doctoral thesis we study stealth CMEs: solar coronal mass ejections that are clearly observed in coronagraph data but do not show significant low-coronal or on-disk signatures of eruption. This lack of coronal signatures makes it challenging to determine their source region and predict their trajectory throughout interplanetary space. Combining PROBA2/SWAP data with that of other instruments, we identify 40 such events and investigate their properties both observationally and statistically. We find that our sample size is insufficient to determine the scaling law for the CME angular width reliably. We therefore analyze in general what the effect is of a limited sample size on the estimation of a power law parameter. Armed with this knowledge, we return to our sample of stealth CMEs, re-analyze the power law for their angular widths and compare the results to the power law found for normal CMEs.

  20. Observing the Unobservable: Identification and Characterisation of Stealth Coronal Mass Ejections

    Science.gov (United States)

    D'Huys, Elke; Seaton, Daniel B.; Poedts, Stefaan; Berghmans, David

    2016-05-01

    I will present my doctoral thesis research on stealth CMEs: solar coronal mass ejections that are clearly observed in coronagraph data but do not show significant low-coronal or on-disk signatures of eruption. This lack of coronal signatures makes it challenging to determine their source region and predict their trajectory throughout interplanetary space. We identified 40 such events and investigated their properties both observationally and statistically. We found that our sample size was insufficient to determine the scaling law for the CME angular width reliably. We therefore analyzed in general what the effect is of a limited sample size on the estimation of a power law parameter. Armed with this knowledge, we returned to our sample of stealth CMEs, re-analyzed the power law for their angular widths and compared the results to the power law found for normal CMEs.

  1. Anomalous Expansion of Coronal Mass Ejections During Solar Cycle 24 and Its Space Weather Implications

    Science.gov (United States)

    Gopalswamy, Nat; Akiyama, Sachiko; Yashiro, Seiji; Xie, Hong; Makela, Pertti; Michalek, Grzegorz

    2014-01-01

    The familiar correlation between the speed and angular width of coronal mass ejections (CMEs) is also found in solar cycle 24, but the regression line has a larger slope: for a given CME speed, cycle 24 CMEs are significantly wider than those in cycle 23. The slope change indicates a significant change in the physical state of the heliosphere, due to the weak solar activity. The total pressure in the heliosphere (magnetic + plasma) is reduced by approximately 40%, which leads to the anomalous expansion of CMEs explaining the increased slope. The excess CME expansion contributes to the diminished effectiveness of CMEs in producing magnetic storms during cycle 24, both because the magnetic content of the CMEs is diluted and also because of the weaker ambient fields. The reduced magnetic field in the heliosphere may contribute to the lack of solar energetic particles accelerated to very high energies during this cycle.

  2. Analysis of Nonlinear Dispersion of a Pollutant Ejected by an External Source into a Channel Flow

    Directory of Open Access Journals (Sweden)

    T. Chinyoka

    2010-01-01

    Full Text Available This paper focuses on the transient analysis of nonlinear dispersion of a pollutant ejected by an external source into a laminar flow of an incompressible fluid in a channel. The influence of density variation with pollutant concentration is approximated according to the Boussinesq approximation, and the nonlinear governing equations of momentum and pollutant concentration are obtained. The problem is solved numerically using a semi-implicit finite difference method. Solutions are presented in graphical form and given in terms of fluid velocity, pollutant concentration, skin friction, and wall mass transfer rate for various parametric values. The model can be a useful tool for understanding the polluting situations of an improper discharge incident and evaluating the effects of decontaminating measures for the water body.

  3. Evolution of Magnetic Helicity During Eruptive Flares and Coronal Mass Ejections

    CERN Document Server

    Priest, Eric; Janvier, Miho

    2016-01-01

    During eruptive solar flares and coronal mass ejections, a non-pot{\\-}ential magnetic arcade with much excess magnetic energy goes unstable and reconnects. It produces a twisted erupting flux rope and leaves behind a sheared arcade of hot coronal loops. We suggest that: the twist of the erupting flux rope can be determined from conservation of magnetic flux and magnetic helicity and equipartition of magnetic helicity. It depends on the geometry of the initial pre-eruptive structure. Two cases are considered, in the first of which a flux rope is not present initially but is created during the eruption by the reconnection. In the second case, a flux rope is present under the arcade in the pre-eruptive state, and the effect of the eruption and reconnection is to add an amount of magnetic helicity that depends on the fluxes of the rope and arcade and the geometry.

  4. Heart failure with normal ejection fraction: consideration of mechanisms other than diastolic dysfunction.

    Science.gov (United States)

    Bench, Travis; Burkhoff, Daniel; O'Connell, John B; Costanzo, Maria Rosa; Abraham, William T; St John Sutton, Martin; Maurer, Mathew S

    2009-03-01

    More than half of patients with heart failure (HF) have a normal ejection fraction (EF). These patients are typically elderly, are predominantly female, and have a high incidence of multiple comorbid conditions associated with development of ventricular hypertrophy and/or interstitial fibrosis. Thus, the cause of HF has been attributed to diastolic dysfunction. However, the same comorbidities may also impact myocardial systolic, ventricular, vascular, renal, and extracardiovascular properties in ways that can also contribute to symptoms of HF by way of mechanisms not related to diastolic dysfunction. Accordingly, the descriptive term HF with normal EF has been suggested as an alternative to the mechanistic term diastolic HF. In this article, we review the current understanding of nondiastolic mechanisms that may contribute to the HF with normal EF syndrome to highlight potential pathways for research that may lead to new targets for therapy.

  5. On Understanding the Nature of Collision of Coronal Mass Ejections Observed by \\textit{STEREO}

    CERN Document Server

    Mishra, Wageesh; Srivastava, Nandita

    2016-01-01

    Our study attempts to understand the collision characteristics of two coronal mass ejections (CMEs) launched successively from the Sun on 2013 October 25. The estimated kinematics, from three-dimensional (3D) reconstruction techniques applied to observations of CMEs by SECCHI/Coronagraphic (COR) and Heliospheric Imagers (HIs), reveal their collision around 37 $R_\\sun$ from the Sun. In the analysis, we take into account the propagation and expansion speeds, impact direction, angular size as well as the masses of the CMEs. These parameters are derived from imaging observations, but may suffer from large uncertainties. Therefore, by adopting head-on as well as oblique collision scenarios, we have quantified the range of uncertainties involved in the calculation of the coefficient of restitution for expanding magnetized plasmoids. Our study shows that the comparatively large expansion speed of the following CME than that of the preceding CME, results in a higher probability of super-elastic collision. We also inf...

  6. Coronal Mass Ejections Observed at the Total Solar Eclipse on 13 November 2012

    CERN Document Server

    Hanaoka, Yoichiro; Ohgoe, Osamu; Sakai, Yoshiaki; Shiota, Kazuo

    2013-01-01

    We carried out white-light observations of the total solar eclipse on 13 November 2012 at two sites, where the totality occurred 35 minutes apart. We caught an ongoing coronal mass ejection (CME) and a pre-CME loop structure just before the eruption in the height range between 1-2 R_sun. The source region of CMEs was revealed to be in this height range, where the material and the magnetic field of CMEs were located before the eruption. This height range includes the gap between the extreme ultraviolet observations of the low corona and the spaceborne white-light observations of the high corona, but the eclipse observation shows that this height range is essentially important to study the CME initiation. The eclipse observation is basically just a snapshot of CMEs, but it indicates that future continuous observations of CMEs within this height range are promising.

  7. First Simultaneous Views of the Axial and Lateral Perspectives of a Coronal Mass Ejection

    CERN Document Server

    Cabello, I; Balmaceda, L; Dohmen, I

    2016-01-01

    The different appearances exhibited by coronal mass ejections (CMEs) are believed to be in part the result of different orientations of their main axis of symmetry, consistent with a flux-rope configuration. There are observational reports of CMEs seen along their main axis (axial perspective) and perpendicular to it (lateral perspective), but no simultaneous observations of both perspectives from the same CME have been reported to date. The stereoscopic views of the telescopes onboard the $Solar$-$Terrestrial$ $Relations$ $Observatory$ (STEREO) twin spacecraft, in combination with the views from the $Solar$ $and$ $Heliospheric$ $Observatory$ (SOHO) and the $Solar$ $Dynamics$ $Observatory$ (SDO), allow us to study the axial and lateral perspectives of a CME simultaneously for the first time. In addition, this study shows that the lateral angular extent ($L$) increases linearly with time, while the angular extent of the axial perspective ($D$) presents this behavior only from the low corona to $\\approx\\,$5 $R_...

  8. Statistical Evidence for Contributions of Flares and Coronal Mass Ejections to Major Solar Energetic Particle Events

    CERN Document Server

    Trottet, G; Klein, K -L; de Wit, T Dudok; Miteva, R

    2014-01-01

    Solar energetic particle (SEP) events are related to flares and coronal mass ejections (CMEs). This work is a new investigation of statistical relationships between SEP peak intensities - deka-MeV protons and near-relativistic electrons - and characteristic quantities of the associated solar activity. We consider the speed of the CME and quantities describing the flare-related energy release: peak flux and fluence of soft X-ray (SXR) emission, fluence of microwave emission. The sample comprises 38 SEP events associated with strong SXR bursts (classes M and X) in the western solar hemisphere between 1997 and 2006, and where the flare-related particle acceleration is accompanied by radio bursts indicating electron escape to the interplanetary space. The main distinction of the present statistical analysis from earlier work is that besides the classical Pearson correlation coefficient the partial correlation coefficients are calculated in order to disentangle the effects of correlations between the solar paramet...

  9. On the enhanced coronal mass ejection detection rate since the solar cycle 23 polar field reversal

    CERN Document Server

    Petrie, Gordon

    2015-01-01

    Coronal mass ejections (CMEs) with angular width $> 30^{\\circ}$ have been observed to occur at a higher rate during solar cycle 24 compared to cycle 23, per sunspot number. This result is supported by data from three independent databases constructed using Large Angle and Spectrometric Coronagraph Experiment (LASCO) coronagraph images, two employing automated detection techniques and one compiled manually by human observers. According to the two databases that cover a larger field of view, the enhanced CME rate actually began shortly after the cycle 23 polar field reversal, in 2004, when the polar fields returned with a 40\\% reduction in strength and interplanetary radial magnetic field became $\\approx 30\\%$ weaker. This result is consistent with the link between anomalous CME expansion and heliospheric total pressure decrease recently reported by Gopalswamy et al.

  10. Urinary Proteomics Pilot Study for Biomarker Discovery and Diagnosis in Heart Failure with Reduced Ejection Fraction

    DEFF Research Database (Denmark)

    Rossing, Kasper; Bosselmann, Helle Skovmand; Gustafsson, Finn

    2016-01-01

    Background Biomarker discovery and new insights into the pathophysiology of heart failure with reduced ejection fraction (HFrEF) may emerge from recent advances in high-throughput urinary proteomics. This could lead to improved diagnosis, risk stratification and management of HFrEF. Methods......EF103 very accurately (area under the curve, AUC = 0.972) discriminated between HFrEF patients (N = 94, sensitivity = 93.6%) and control individuals with and without impaired renal function and hypertension (N = 552, specificity = 92.9%). Interestingly, HFrEF103 showed low sensitivity (12...... to determine a vast array of HFrEF-related urinary peptide biomarkers which might help improving our understanding and diagnosis of heart failure....

  11. MAVEN observations of the response of Mars to an interplanetary coronal mass ejection.

    Science.gov (United States)

    Jakosky, B M; Grebowsky, J M; Luhmann, J G; Connerney, J; Eparvier, F; Ergun, R; Halekas, J; Larson, D; Mahaffy, P; McFadden, J; Mitchell, D F; Schneider, N; Zurek, R; Bougher, S; Brain, D; Ma, Y J; Mazelle, C; Andersson, L; Andrews, D; Baird, D; Baker, D; Bell, J M; Benna, M; Chaffin, M; Chamberlin, P; Chaufray, Y-Y; Clarke, J; Collinson, G; Combi, M; Crary, F; Cravens, T; Crismani, M; Curry, S; Curtis, D; Deighan, J; Delory, G; Dewey, R; DiBraccio, G; Dong, C; Dong, Y; Dunn, P; Elrod, M; England, S; Eriksson, A; Espley, J; Evans, S; Fang, X; Fillingim, M; Fortier, K; Fowler, C M; Fox, J; Gröller, H; Guzewich, S; Hara, T; Harada, Y; Holsclaw, G; Jain, S K; Jolitz, R; Leblanc, F; Lee, C O; Lee, Y; Lefevre, F; Lillis, R; Livi, R; Lo, D; Mayyasi, M; McClintock, W; McEnulty, T; Modolo, R; Montmessin, F; Morooka, M; Nagy, A; Olsen, K; Peterson, W; Rahmati, A; Ruhunusiri, S; Russell, C T; Sakai, S; Sauvaud, J-A; Seki, K; Steckiewicz, M; Stevens, M; Stewart, A I F; Stiepen, A; Stone, S; Tenishev, V; Thiemann, E; Tolson, R; Toublanc, D; Vogt, M; Weber, T; Withers, P; Woods, T; Yelle, R

    2015-11-01

    Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.

  12. Automated Detection of Coronal Mass Ejections in STEREO Heliospheric Imager data

    CERN Document Server

    Pant, V; Rodriguez, L; Mierla, M; Banerjee, D; Davies, J A

    2016-01-01

    We have performed, for the first time, the successful automated detection of Coronal Mass Ejections (CMEs) in data from the inner heliospheric imager (HI-1) cameras on the STEREO A spacecraft. Detection of CMEs is done in time-height maps based on the application of the Hough transform, using a modified version of the CACTus software package, conventionally applied to coronagraph data. In this paper we describe the method of detection. We present the result of the application of the technique to a few CMEs that are well detected in the HI-1 imagery, and compare these results with those based on manual cataloging methodologies. We discuss in detail the advantages and disadvantages of this method.

  13. Prognostic value of right ventricular ejection fraction in pulmonary arterial hypertension.

    Science.gov (United States)

    Courand, Pierre-Yves; Pina Jomir, Géraldine; Khouatra, Chahéra; Scheiber, Christian; Turquier, Ségolène; Glérant, Jean-Charles; Mastroianni, Bénédicte; Gentil, Béatrice; Blanchet-Legens, Anne-Sophie; Dib, Alfred; Derumeaux, Geneviève; Humbert, Marc; Mornex, Jean-François; Cordier, Jean-François; Cottin, Vincent

    2015-01-01

    Right ventricle ejection fraction (RVEF) evaluated with magnetic resonance imaging is a strong determinant of patient outcomes in pulmonary arterial hypertension. We evaluated the prognostic value of RVEF assessed with conventional planar equilibrium radionuclide angiography at baseline and change 3-6 months after initiating pulmonary arterial hypertension-specific therapy. In a prospective cohort of newly diagnosed patients with idiopathic, heritable or anorexigen-associated pulmonary arterial hypertension, RVEF was measured at baseline (n=100) and 3-6 months after initiation of therapy (n=78). After a median follow-up of 4.1 years, 41 deaths occurred, including 35 from cardiovascular causes. Patients with a (median) baseline RVEF >25% had better survival than those with a RVEF arterial hypertension.

  14. Extracellular matrix remodeling in patients with ischemic chronic heart failure with preserved ejection fraction

    Directory of Open Access Journals (Sweden)

    V. D. Syvolap

    2015-04-01

    Full Text Available Aim. To identify features, relationships between parameters of the extracellular matrix and renal function in 110 patients with ischemic chronic heart failure the activity of collagen metabolism markers (MMP-9, TIMP-1, PICP, cystatin C, structural and functional parameters of the heart were studied using ELISA, echocardiography. Results. It was established that imbalance in the system MMP/TIMP in ischemic heart failure with preserved left ventricular ejection fraction leads to disruption of the extracellular matrix structural functional sufficiency, increases functional failure and is associated with impaired renal function. Conclusion. Correlation analysis showed significant relationships between MMP/TIMP and GFR, cystatin C, indicating that the significant role of extracellular matrix imbalance in the development of renal dysfunction in patients with ischemic chronic heart failure.

  15. Ventricular fibrillation via torsade des pointes of cardiac sarcoidosis with preserved left ventricular ejection fraction.

    Science.gov (United States)

    Sekihara, Takayuki; Nakane, Eisaku; Nakasone, Kazutaka; Inoko, Moriaki

    2016-10-25

    Generally, low left ventricular ejection fraction (LVEF) is a risk for ventricular arrhythmia in patients with cardiac sarcoidosis. We present a case of cardiac sarcoidosis with preserved LVEF that evoked ventricular fibrillation (VF). A 73-year-old woman with VF presented to our emergency department. She had a history of ocular sarcoidosis, with gradual thinning of the basal intraventricular septum. LVEF was 62% on the most recent echocardiography. The electrocardiogram after defibrillation showed complete atrioventricular block (CAVB) with QT segment prolongation and frequent ventricular premature beats. VF via torsade des pointes (TdP) was suspected, and temporary intravenous ventricular pacing and magnesium sulfate infusion suppressed her VF. Cardiac sarcoidosis was diagnosed, and an implantable cardioverter defibrillator was implanted. Patients with cardiac sarcoidosis with CAVB are at risk of evoking VF via TdP regardless of LVEF. If cardiac sarcoidosis is suspected, early diagnosis and risk stratification of ventricular arrhythmia are important. 2016 BMJ Publishing Group Ltd.

  16. Effect of calf stimulation on milk ejection in reindeer (Rangifer tarandus

    Directory of Open Access Journals (Sweden)

    Hallvard Gjøstein

    2004-04-01

    Full Text Available The objective of this study was to establish methods for stimulating the milk ejection in reindeer kept for milking purpose. Calves were used to stimulate milk does’ let down. In experiment 1, five does were allowed olfactory, acoustic and visual contact with their calves during milking, whereas four does were milked in isolation. The treatment of the groups was alternated every day during the eight days experiment. Olfactory, acoustic and visual contact with the calf did not influence the doe’s milk yield. The milk yield varied significantly between individual females within treatment (P < 0.01. In experiment 2, the calves were allowed to suckle their mother for a short period (two seconds prior to milking being initiated. The same alternate design as in experiment 1 with groups consisting of three and two animals respectively was used, and the experiment lasted four days. The pre-suckling stimulation significantly increased the milk ejection measured as milk yield (P < 0.05, and the residual milk after the treatment was negectible. Moreover, the milk ejection varied between individual females within treatment (P < 0.05. We conclude that it is possible to achieve a complete milk removal by machine milking after the does have been pre-stimulated by suckling of calves. Olfactory, acoustic and visual contact with calves during milking failed to influence the milk ejection in this study. However, the results have to be interpreted with caution due to limited sample size.Abstract in Norwegian / Sammendrag: Formålet med dette forsøket var å prøve ut ulike metoder for å stimulere nedgivninga av melk hos rein. Kalvene ble tatt i bruk for å stimulere nedgivninga. I forsøk 1 hadde simla lyd-, lukt og synskontakt med kalven mens melkingen pågikk. Vi benyttet et ”switch back design” der fem simler hadde kontakt med kalven under melkingen og fire ble melket uten kontakt. Behandlingen ble byttet om annenhver dag i de åtte dagene fors

  17. Evidence for shock generation in the solar corona in the absence of coronal mass ejections

    Science.gov (United States)

    Eselevich, V. G.; Eselevich, M. V.; Zimovets, I. V.; Sharykin, I. N.

    2017-09-01

    The solar event SOL2012-10-23T03:13, which was associated with a X1.8 flare without an accompanying coronal mass ejection (CME) and with a Type II radio burst, is analyzed. A method for constructing the spatial and temporal profiles of the difference brightness detected in the AIA/SDOUVand EUV channels is used together with the analysis of the Type II radio burst. The formation and propagation of a region of compression preceded by a collisional shock detected at distances R shock could be due to a transient (impulsive) action exerted on the surrounding plasma by an eruptive, high-temperature magnetic rope. The initial instability and eruption of this rope could be initiated by emerging magnetic flux, and its heating from magnetic reconnection. The cessation of the eruption of the rope could result from its interaction with surrounding magnetic structures (coronal loops).

  18. Ion Trapping, Storage, and Ejection in Structures for Lossless Ion Manipulations.

    Science.gov (United States)

    Zhang, Xinyu; Garimella, Sandilya V B; Prost, Spencer A; Webb, Ian K; Chen, Tsung-Chi; Tang, Keqi; Tolmachev, Aleksey V; Norheim, Randolph V; Baker, Erin S; Anderson, Gordon A; Ibrahim, Yehia M; Smith, Richard D

    2015-06-16

    A new Structures for Lossless Ion Manipulations (SLIM) module, having electrode arrays patterned on a pair of parallel printed circuit boards (PCB), was constructed and utilized to investigate capabilities for ion trapping at a pressure of 4 Torr. Positive ions were confined by application of RF voltages to a series of inner rung electrodes with alternating phase on adjacent electrodes, in conjunction with positive DC potentials on surrounding guard electrodes on each PCB. An axial DC field was also introduced by stepwise varying the DC potentials applied to the inner rung electrodes to control the ion transport and accumulation inside the ion trapping region. We show that ions can be trapped and accumulated with up to 100% efficiency, stored for at least 5 h with no significant losses, and then could be rapidly ejected from the SLIM trap. The present results provide a foundation for the development of much more complex SLIM devices that facilitate extended ion manipulations.

  19. Targeting heart failure with preserved ejection fraction: current status and future prospects

    Directory of Open Access Journals (Sweden)

    Kanwar M

    2016-04-01

    Full Text Available Manreet Kanwar, Claire Walter, Megan Clarke, Maria Patarroyo-Aponte Department of Cardiology, Allegheny General Hospital, Pittsburgh, PA, USA Abstract: Heart failure with preserved ejection fraction (HFpEF portrays a significant burden in terms of prevalence, morbidity, mortality, and health care costs. There is a lack of consensus on the basic pathophysiology, definition, and therapeutic targets for therapy for this syndrome. To date, there are no approved therapies available for reducing mortality or hospitalization for these patients. Several clinical trials have recently started to try and bridge this major gap. There is an urgent need to focus on drug and device development for HFpEF as well as to understand HFpEF pathophysiology. Keywords: HFpEF therapies, diastolic dysfunction

  20. Can Biomarkers Help to Diagnose Early Heart Failure with Preserved Ejection Fraction?

    Directory of Open Access Journals (Sweden)

    Jaroslav Meluzín

    2015-01-01

    Full Text Available Early heart failure with preserved ejection fraction (HFpEF is a frequent disease, but its diagnosis is difficult and relies mostly on the evidence of left ventricular filling pressure (LVFP elevation during exercise. Several reports have suggested that natriuretic peptides plasma levels reflect exercise-induced increase in LVFP, but they still have significant limitations. In this context, any new laboratory biomarker that can accurately reflect LVFP elevation during exercise is desirable. Recently, cardiotrophin-1, soluble endoglin, ST2, growth differentiation factor 15, galectin-3, and other new laboratory markers associated with LVFP have emerged. However, the current data on the relationship of these biomarkers and diastolic dysfunction are limited to resting conditions. Therefore, their secretion deserves to be tested under the exercise to determine their potential role in making a diagnosis of early HFpEF.