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Sample records for annular plane systolic

  1. Tricuspid annular plane systolic excursion and response to cardiac resynchronization therapy

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; Ghio, Stefano; St John Sutton, Martin;

    2011-01-01

    The aims of this study were to evaluate tricuspid annular plane systolic excursion (TAPSE) as a predictor of left ventricular (LV) reverse remodeling and clinical benefit of cardiac synchronization therapy (CRT) and to evaluate the effect of CRT on TAPSE in patients with mildly symptomatic systolic...... heart failure as a substudy of the REsyncronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) trial....

  2. Tricuspid Annular Plane Systolic Excursion pada Bayi Kurang Bulan dan Cukup Bulan

    Directory of Open Access Journals (Sweden)

    Sri Endah Rahayuningsih

    2011-12-01

    Full Text Available A preterm infant is a baby born with gestational age less than 37 weeks. Preterm babies tend to have problems compared to normal ones. Premature gestational age might result in immaturity of all organ systems of the body including cardiovascular organs. The aim of this study was to find out the right ventricle function by tricuspid annular plane systolic excursion (TAPSE and left ventricle by ejection fraction and shortening fraction using echocardiography on preterm babies. The subject of this study were term and preterm babies who fulfilled the inclusion criteria: appropiate gestational age babies 3–30 days old. This was an analytic descriptive study with cross-sectional method held in Department of Child Health Dr. Hasan Sadikin Hospital Bandung during July–October 2010, and statistical analysis using t–test Spearman rank correlation test. The result of the study showed that the right ventricle function examined by TAPSE method was different on preterm compared to term babies (p=0.006. No significant difference was found in the ejection fraction between preterm and term babies (p=0.22 and so did the shortening fraction (p=0.20. It was concluded that there is a difference in the right ventricle function by TAPSE method between preterm (lower and term babies.

  3. Tricuspid annular plane systolic excursion and pulmonary arterial systolic pressure relationship in heart failure: an index of right ventricular contractile function and prognosis.

    Science.gov (United States)

    Guazzi, M; Bandera, F; Pelissero, G; Castelvecchio, S; Menicanti, L; Ghio, S; Temporelli, P L; Arena, R

    2013-11-01

    Echo-derived pulmonary arterial systolic pressure (PASP) and right ventricular (RV) tricuspid annular plane systolic excursion (TAPSE; from the end of diastole to end-systole) are of basic relevance in the clinical follow-up of heart failure (HF) patients, carrying two- to threefold increase in cardiac risk when increased and reduced, respectively. We hypothesized that the relationship between TAPSE (longitudinal RV fiber shortening) and PASP (force generated by the RV) provides an index of in vivo RV length-force relationship, with their ratio better disclosing prognosis. Two hundred ninety-three HF patients with reduced (HFrEF, n = 247) or with preserved left ventricular (LV) ejection fraction (HFpEF, n = 46) underwent echo-Doppler studies and N-terminal pro-brain-type natriuretic peptide assessment and were tracked for adverse events. The median follow-up duration was 20.8 mo. TAPSE vs. PASP relationship showed a downward regression line shift in nonsurvivors who were more frequently presenting with higher PASP and lower TAPSE. HFrEF and HFpEF patients exhibited a similar distribution along the regression line. Given the TAPSE, PASP, and TAPSE-to-PASP ratio (TAPSE/PASP) collinearity, separate Cox regression and Kaplan-Meier analyses were performed: one with TAPSE and PASP as individual measures, and the other combining them in ratio form. Hazard ratios for variables retained in the multivariate regression were as follows: TAPSE/PASP

  4. Tricuspid annular plane systolic excursion does not correlate with right ventricular ejection fraction in patients with hypoplastic left heart syndrome after Fontan palliation.

    Science.gov (United States)

    Avitabile, Catherine M; Whitehead, Kevin; Fogel, Mark; Mercer-Rosa, Laura

    2014-10-01

    Tricuspid annular plane systolic excursion (TAPSE) reflects longitudinal myocardial shortening, the main component of right ventricular (RV) contraction in normal hearts. To date, TAPSE has not been extensively studied in patients with hypoplastic left heart syndrome (HLHS) and systemic RVs after Fontan palliation. This retrospective study investigated HLHS patients after Fontan with cardiac magnetic resonance (CMR) performed between 1 January 2010 and 1 August 2012 and transthoracic echocardiogram (TTE) performed within 6 months of CMR. The maximal apical displacement of the lateral tricuspid valve annulus was measured on CMR (using four-chamber cine images) and on TTE (using two-dimensional apical views). To create TTE-TAPSE z-scores, published reference data were used. Intra- and interobserver variability was tested with analysis of variance. Inter-technique agreement of TTE and CMR was tested with Bland-Altman analysis. In this study, 30 CMRs and TTEs from 29 patients were analyzed. The age at CMR was 14.1 ± 7.1 years, performed 11.9 ± 7.8 years after Fontan. For CMR-TAPSE, the intraclass correlation coefficients for inter- and intraobserver variability were 0.89 and 0.91, respectively. The TAPSE measurements were 0.57 ± 0.2 cm on CMR and 0.70 ± 0.2 cm on TTE (TTE-TAPSE z score, -8.7 ± 1.0). The mean difference in TAPSE between CMR and TTE was -0.13 cm [95 % confidence interval (CI) -0.21 to -0.05], with 95 % limits of agreement (-0.55 to 0.29 cm). The study showed no association between CMR-TAPSE and RVEF (R = 0.08; p = 0.67). In patients with HLHS after Fontan, TAPSE is reproducible on CMR and TTE, with good agreement between the two imaging methods. Diminished TAPSE suggests impaired longitudinal shortening in the systemic RV. However, TAPSE is not a surrogate for RVEF in this study population. PMID:24840648

  5. New mitral annular force transducer optimized to distinguish annular segments and multi-plane forces.

    Science.gov (United States)

    Skov, Søren Nielsen; Røpcke, Diana Mathilde; Ilkjær, Christine; Rasmussen, Jonas; Tjørnild, Marcell Juan; Jimenez, Jorge H; Yoganathan, Ajit P; Nygaard, Hans; Nielsen, Sten Lyager; Jensen, Morten Olgaard

    2016-03-21

    Limited knowledge exists about the forces acting on mitral valve annuloplasty repair devices. The aim of this study was to develop a new mitral annular force transducer to measure the forces acting on clinically used mitral valve annuloplasty devices. The design of an X-shaped transducer in the present study was optimized for simultaneous in- and out-of-plane force measurements. Each arm was mounted with strain gauges on four circumferential elements to measure out-of-plane forces, and the central parts of the X-arms were mounted with two strain gauges to measure in-plane forces. A dedicated calibration setup was developed to calibrate isolated forces with tension and compression for in- and out-of-plane measurements. With this setup, it was possible with linear equations to isolate and distinguish measured forces between the two planes and minimize transducer arm crosstalk. An in-vitro test was performed to verify the crosstalk elimination method and the assumptions behind it. The force transducer was implanted and evaluated in an 80kg porcine in-vivo model. Following crosstalk elimination, in-plane systolic force accumulation was found to be in average 4.0±0.1N and the out-of-plane annular segments experienced an average force of 1.4±0.4N. Directions of the systolic out-of-plane forces indicated movements towards a saddle shaped annulus, and the transducer was able to measure independent directional forces in individual annular segments. Further measurements with the new transducer coupled with clinical annuloplasty rings will provide a detailed insight into the biomechanical dynamics of these devices. PMID:26903412

  6. Mitral annular systolic velocity as a marker of preclinical systolic dysfunction among patients with arterial hypertension

    Directory of Open Access Journals (Sweden)

    Daskalov Ivaylo Rilkov

    2012-11-01

    Full Text Available Abstract Background The aim of this study was to investigate early changes in left ventricular longitudinal systolic function in patients with hypertension (HTN with and without concomitant diastolic dysfunction (DD and the clinical implications of these findings. Method We enrolled 299 patients with HTN and 297 age-matched patients with HTN and DD and compared both groups with an age-matched control group consisting of 100 healthy subjects. The long axis systolic function was investigated by determining the average peak systolic velocity of the septal and lateral mitral sites (Smavg using spectral pulsed wave tissue Doppler imaging (TDI. Results We found a strong negative trend toward the reduction of velocity, which is dependent on the grade of HTN, on the magnitude of DD, and also on the gender and age of the subjects (r=−0.891/-0.580; p Conclusion The strength of the study is the analysis of incremental changes in longitudinal contraction in patients with different stage of HTN but not so many the classification of the degree of systolic dysfunction. The importance of our results lies in the fact that these initial changes in systolic contraction could be used as an early sign that should prompt optimization of the treatment of HTN.

  7. The relationship between mitral annular systolic velocity and ejection fraction in patients with preserved global systolic function of the left ventricle

    OpenAIRE

    Daskalov, Ivaylo Rilkov; Daskalova, Ivona Kirilova; Demirevska, Lilia Davidkova; Atzev, Borislav Georgiev

    2013-01-01

    Background The aim of the study was to investigate the relationship between the ejection fraction (EF) and the mitral annular systolic velocity (Sm) in patients with preserved left ventricular systolic function (EF>55%). The study task was to evaluate whether the assessment of Sm(avg) can be used as an alternative to the Simpson’s method in assessment of the EF. The expected benefit was that Sm could be used to predict EF, when EF is difficult to assess due to poor image quality (IQ). Method ...

  8. Characterization of the Annular Core Research Reactor (ACRR Neutron Radiography System Imaging Plane

    Directory of Open Access Journals (Sweden)

    Kaiser Krista

    2016-01-01

    Full Text Available The Annular Core Research Reactor (ACRR at Sandia National Laboratories (SNL is an epithermal pool-type research reactor licensed up to a thermal power of 2.4 MW. The ACRR facility has a neutron radiography facility that is used for imaging a wide range of items including reactor fuel and neutron generators. The ACRR neutron radiography system has four apertures (65:1, 125:1, 250:1, and 500:1 available to experimenters. The neutron flux and spectrum as well as the gamma dose rate were characterized at the imaging plane for the ACRR's neutron radiography system for the 65:1, 125:1 and 250:1 apertures.

  9. Characterization of the Annular Core Research Reactor (ACRR) Neutron Radiography System Imaging Plane

    Science.gov (United States)

    Kaiser, Krista; Chantel Nowlen, K.; DePriest, K. Russell

    2016-02-01

    The Annular Core Research Reactor (ACRR) at Sandia National Laboratories (SNL) is an epithermal pool-type research reactor licensed up to a thermal power of 2.4 MW. The ACRR facility has a neutron radiography facility that is used for imaging a wide range of items including reactor fuel and neutron generators. The ACRR neutron radiography system has four apertures (65:1, 125:1, 250:1, and 500:1) available to experimenters. The neutron flux and spectrum as well as the gamma dose rate were characterized at the imaging plane for the ACRR's neutron radiography system for the 65:1, 125:1 and 250:1 apertures.

  10. Mass transfer in back to back elbows arranged in an out of plane configuration under annular two phase flow conditions

    International Nuclear Information System (INIS)

    Highlights: • Mass transfer in back to back elbows in an out of plane configuration was measured. • Tests were performed under annular two phase air–water conditions. • Highest mass transfer was on the outer wall of the first elbow. • The mass transfer on the second elbow was always less than that in the first elbow. • The mass transfer increased with an increase in the air superficial velocity. - Abstract: The mass transfer in back-to-back elbows arranged in an out of plane configuration has been measured under annular two phase air–water flow conditions. The measurements were performed using a wall dissolving technique with the elbow sections cast from gypsum. Experiments were performed to study the effect of increasing the water and air superficial velocities, and the effect of separation distance between the elbows. The highest mass transfer for all cases occurs on the outer wall of the first elbow, and the magnitude was not affected by the separation distance between the elbows. The maximum mass transfer in the second elbow was approximately 60 percent of the maximum value in the first elbow. The mass transfer increased with an increase in either the water or air superficial velocity, with the air velocity having a greater effect. The roughness development in the upstream pipe was modest, but was significant in the regions of high mass transfer on the first and second elbow

  11. Characterization of the Annular Core Research Reactor (ACRR) Neutron Radiography System Imaging Plane

    OpenAIRE

    Kaiser Krista; Chantel Nowlen K.; Russell DePriest K.

    2016-01-01

    The Annular Core Research Reactor (ACRR) at Sandia National Laboratories (SNL) is an epithermal pool-type research reactor licensed up to a thermal power of 2.4 MW. The ACRR facility has a neutron radiography facility that is used for imaging a wide range of items including reactor fuel and neutron generators. The ACRR neutron radiography system has four apertures (65:1, 125:1, 250:1, and 500:1) available to experimenters. The neutron flux and spectrum as well as the gamma dose rate were char...

  12. Simplified description of out-of-plane waves in thin annular elastic plates

    DEFF Research Database (Denmark)

    Zadeh, Maziyar Nesari; Sorokin, Sergey

    2013-01-01

    Dispersion relations are derived for the out-of-plane wave propagation in planar elastic plates with constant curvature using the classical Kirchhoff thin plate theory. The dispersion diagrams and the mode shapes are compared with their counterparts for a straight plate strip and the role of...... curvature is assessed for plates with unconstrained edges. Elementary Bernoulli–Euler theory for a beam of rectangular cross-section with the circular shape of its axis is also employed to analyze the wave guide properties of this structure in its out-of-plane deformation. The applicability range of the...... elementary beam theory is validated. The wave finite element method in the formulation of the three-dimensional elasticity theory is used to ensure that the comparison of dispersion diagrams is performed in the frequency range, where the classical thin plate theory is valid. Thus, the paper summarizes the...

  13. Annular pancreas

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001142.htm Annular pancreas To use the sharing features on this page, please enable JavaScript. An annular pancreas is a ring of pancreatic tissue that encircles ...

  14. Early right ventricular systolic dysfunction in patients with systemic sclerosis without pulmonary hypertension: a Doppler Tissue and Speckle Tracking echocardiography study

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2010-01-01

    Full Text Available Abstract Background Isovolumetric acceleration (IVA is a novel tissue Doppler parameter for the assessment of systolic function. The aim of this study was to evaluate IVA as an early parameter for the detection of right ventricular (RV systolic dysfunction in patients with systemic sclerosis (SSc without pulmonary hypertension. Methods 22 patients and 22 gender- and age-matched healthy subjects underwent standard echocardiography with tissue Doppler imaging (TDI and speckle tracking strain to assess RV function. Results Tricuspid annular plane systolic excursion (TAPSE (23.2 ± 4.1 mm vs. 26.5 ± 2.9 mm, p 2 vs. 4.1 ± 0.8 m/s2, p Conclusion IVA is a useful tool with high-predictive power to detect early right ventricular systolic impairment in patients with SSc and without pulmonary hypertension.

  15. Right Ventricular Systolic Dysfunction Is Common in Hypertensive Heart Failure: A Prospective Study in Sub-Saharan Africa

    Science.gov (United States)

    Ojji, Dike B.; Lecour, Sandrine; Atherton, John J.; Blauwet, Lori A.; Alfa, Jacob; Sliwa, Karen

    2016-01-01

    Introduction Right ventricular (RV) systolic dysfunction is now recognized widely as a strong and independent predictor of adverse outcomes in patients with heart failure (HF). Reduction of RV systolic function more closely predicts impaired exercise tolerance and poor survival than does left ventricular (LV) systolic function. In spite of this, there is a dearth of data on RV function in hypertensive HF which is the commonest form of HF in sub-Saharan Africa. We therefore conducted a prospective cohort study of hypertensive HF patients presenting to the University of Abuja Teaching Hospital, Abuja, Nigeria over an 8 year period. Methods Each subject had transthoracic echocardiography performed on them according to the guidelines of American Society of Echocardiography. RV systolic function was defined as a tricuspid annular plane systolic excursion (TAPSE) <15mm using M-mode echocardiography. Results RV systolic dysfunction was identified in 272 (44.5%) of the 611 subjects that were studied. Subjects with TAPSE less than 15mm had worse prognosis compared to those with TAPSE ≥15mm.There was a significant correlation between TAPSE and other adverse prognostic markers including left and right atrial area, LV size, LV mass, LV ejection fraction, restrictive mitral inflow and RV systolic pressure (RVSP). However, LV ejection fraction and right atrial area were the only independent determinants of RV systolic dysfunction. Conclusions Hypertensive HF is a major cause of RV systolic dysfunction even in a population with a low prevalence of coronary artery disease, and RV systolic dysfunction is associated with poor prognosis in hypertensive HF. Detailed assessment of RV function should therefore be part of the echocardiography evaluation of patients with hypertensive HF. PMID:27073856

  16. In-plane free vibration of FGM annular plates considering temperature effect%温度影响下 FGM圆环板的面内自由振动分析

    Institute of Scientific and Technical Information of China (English)

    滕兆春; 蒲育

    2015-01-01

    基于二维弹性理论和Hamilton原理,假设材料物理性质随温度变化且沿圆环板径向按照幂律梯度分布,导出了温度影响下 FGM薄圆环板面内自由振动的运动微分方程。用微分求积法(DQM)计算了温度影响下 FGM圆环板面内自由振动的无量纲频率,并与各向同性材料圆环板面内自由振动的无量纲频率进行了比较,说明该分析方法的有效性。同时考虑了沿圆环板径向均匀升温和非均匀升温两种情况下,几何参数、材料性质和温度变化对面内自由振动频率的影响。%Based on the two-dimensional elastic theory and the Hamilton's principle,the differential motion equations for in-plane free vibration of the functionally graded material thin annular plate in thermal environment were derived.In the equations,the material properties were assumed to be temperature-dependent and graded in the radial direction of annular plates according to power law distributions.By using differential quadrature method (DQM),the dimensionless frequency parameters of in-plane free vibration of FGM annular plates under thermal environment were obtained.The formulations were validated by comparing the results with those available in literatures.Considering the cases of uniform and variable temperature rise distribution in the radial direction of annular plate respectively,the effects of geometrical parameters,material graded index and temperature rise on the natural frequencies of in-plane free vibration of annular plates were investigated.

  17. Granuloma annulare.

    Science.gov (United States)

    Gupta, Diptesh; Hess, Brian; Bachegowda, Lohith

    2010-01-01

    We present a case of a 77-year-old, diabetic male with a 20-year history of a migratory erythematous, asymptomatic, generalized, nonscaly, and nonitchy rash that started over the dorsum of his left hand. On examination, there were multiple annular erythematous plaques, distributed symmetrically and diffusely over his torso and arms, with central clearing and no scales. A punch biopsy of the skin helped us to arrive at the diagnosis of a generalized granuloma annulare (GA). GA is a benign, self-limiting skin condition of unknown etiology that is often asymptomatic. The cause of this condition is unknown, but it has been associated with diabetes mellitus, infections such as HIV, and malignancies such as lymphoma. These lesions typically start as a ring of flesh-colored papules that slowly progress with central clearing. Lack of symptoms, scaling, or associated vesicles helps to differentiate GA from other skin conditions such as tinea corporis, pityriasis rosea, psoriasis, or erythema annulare centrifugum. Treatment is often not needed as the majority of these lesions are self-resolving within 2 years. Treatment may be pursued for cosmetic reasons. Available options include high-dose steroid creams, PUVA, cryotherapy, or drugs such as niacinamide, infliximab, Dapsone, and topical calcineurin inhibitors. PMID:20209383

  18. Annular Flow Distribution test

    International Nuclear Information System (INIS)

    This report documents the Babcock and Wilcox (B ampersand W) Annular Flow Distribution testing for the Savannah River Laboratory (SRL). The objective of the Annular Flow Distribution Test Program is to characterize the flow distribution between annular coolant channels for the Mark-22 fuel assembly with the bottom fitting insert (BFI) in place. Flow rate measurements for each annular channel were obtained by establishing ''hydraulic similarity'' between an instrumented fuel assembly with the BFI removed and a ''reference'' fuel assembly with the BFI installed. Empirical correlations of annular flow rates were generated for a range of boundary conditions

  19. 二尖瓣环位移对肥厚性重构患者左室收缩功能的评估作用%Evaluation of left ventricular systolic dysfunction by mitral annular displacement in patients with cardiac hypertrophy and remodeling

    Institute of Scientific and Technical Information of China (English)

    吴卫华; 黄艳; 陆静; 马兰; 魏松霞; 谢晓奕; 刘奇志; 王雷; 杨玲

    2011-01-01

    目的 应用超声二维斑点追踪显像技术测定二尖瓣环位移(MAD),探讨其在评估肥厚性重构所致的早期左室收缩功能减退方面的临床应用价值.方法 选择86例左室射血分数(LVEF)正常(>50%)的各类心肌肥厚(左室壁厚度≥12 mm)患者作为研究对象.采用Philips Sonos iE33超声仪进行检查,先通过M型超声计算出相对室壁厚度(RWT),然后取心尖四腔观分别采集二维和实时三维全容积(RT3D)图像.应用QLAB 6.2在机量化分析软件分别获取MAD相关参数(包括二尖瓣环中点位移和左室长轴缩短率)和经RT3D图像测得左室射血分数(RT3D-LVEF);计算三维心肌重构指标,包括左室舒末容积指数(LVEDVI)和左室质量指数(LVMI).将心肌肥厚患者中RWT<0.45且LVMI在正常范围内的患者归入肥厚正常几何构型组(HNG组),其余归入肥厚重构组(HR组);以46名年龄相匹配的健康志愿者作为正常对照组.结果 HNG组、HR组和正常对照组的RT3D-LVEF均在正常范围内,两两比较差异均无统计学意义(P>0.05).HR组的MAD各值和LVEDVI均显著低于HNG组和正常对照组,差异均有统计学意义(P<0.01或P<0.05);HNG组与正常对照组MAD相关参数值和LVEDVI比较差异均无统计学意义(P>0.05).Bland-Altman分析显示MAD各值的可重复性较高.结论 在心肌肥厚性重构患者中,与LVEF比较,MAD能更早地反映患者的左室收缩功能减退情况.%Objective To investigate the value of mitral annular displacement (MAD) by two-dimensional speckle tracking in evaluating left ventricular systolic dysfunction in patients with cardiac hypertrophy and remodeling.Methods Eightysix patients with cardiac hypertrophy ( left ventricular wall thickness ≥ 12 mm) and normal left ventricular ejection fraction (LVEF) ( > 50% ) were selected.Philips Sonos iE33 ultrasound device was used for examinations.Relative wall thickness (IRWT) was calculated by M mode ultrasound, and two

  20. Dyck's surfaces, systoles, and capacities

    CERN Document Server

    Katz, Mikhail G

    2012-01-01

    We prove an optimal systolic inequality for nonpositively curved Dyck's surfaces. The extremal surface is flat with eight conical singularities, six of angle theta and two of angle 9?pi - theta, for a suitable theta with cos(theta) Q(sqrt{19}). Relying on capacity estimates, we also show that the extremal surface is not conformally equivalent to the hyperbolic surface with maximal systole, yielding a first example of systolic extremality with this behavior.

  1. Annular pancreas (image)

    Science.gov (United States)

    Annular pancreas is an abnormal ring or collar of pancreatic tissue that encircles the duodenum (the part of the ... intestine that connects to stomach). This portion of pancreas can constrict the duodenum and block or impair ...

  2. Confocal Annular Josephson Tunnel Junctions

    Science.gov (United States)

    Monaco, Roberto

    2016-04-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  3. Confocal Annular Josephson Tunnel Junctions

    Science.gov (United States)

    Monaco, Roberto

    2016-09-01

    The physics of Josephson tunnel junctions drastically depends on their geometrical configurations and here we show that also tiny geometrical details play a determinant role. More specifically, we develop the theory of short and long annular Josephson tunnel junctions delimited by two confocal ellipses. The behavior of a circular annular Josephson tunnel junction is then seen to be simply a special case of the above result. For junctions having a normalized perimeter less than one, the threshold curves in the presence of an in-plane magnetic field of arbitrary orientations are derived and computed even in the case with trapped Josephson vortices. For longer junctions, a numerical analysis is carried out after the derivation of the appropriate motion equation for the Josephson phase. We found that the system is modeled by a modified and perturbed sine-Gordon equation with a space-dependent effective Josephson penetration length inversely proportional to the local junction width. Both the fluxon statics and dynamics are deeply affected by the non-uniform annulus width. Static zero-field multiple-fluxon solutions exist even in the presence of a large bias current. The tangential velocity of a traveling fluxon is not determined by the balance between the driving and drag forces due to the dissipative losses. Furthermore, the fluxon motion is characterized by a strong radial inward acceleration which causes electromagnetic radiation concentrated at the ellipse equatorial points.

  4. Generalized granuloma annulare

    Directory of Open Access Journals (Sweden)

    Khatri M

    1995-01-01

    Full Text Available A 35-years-old female patient had generalized pruritic papular lesions, distributed like dermatitis herpetiformis for last 4 years. Histopathologic changes were typical of granuloma annulare with negative results of direct immunofluorescence. The patient did not have association of diabetes mellitus or any other systemic disease. She failed to respond to dapsone therapy and 13-cis-retinoic acid.

  5. Oscillating annular liquid membranes

    International Nuclear Information System (INIS)

    The response of annular liquid membranes (e.g. used as protection systems in laser fusion reactors) to sinusoidal mass flow rate fluctuations at the nozzle exit is analyzed as a function of the amplitude and frequency of the axial velocity fluctuations at the nozzle exit and thermodynamic compression of the gas enclosed by the membrane. The pressure of the gases enclosed by the annular membrane and the axial distance at which the annular membrane merges on the symmetry axis are periodic functions of time which have the same period as that of the mass flow rate fluctuations at the nozzle exit. They are also nearly sinusoidal functions of time for small amplitudes of the mass flow rate fluctuations at the nozzle exit, and exhibit delay and lag times with respect to the sinusoidal axial velocity fluctuations at the nozzle exit. The delay and the lag times are functions of the amplitude and frequency of the mass flow rate fluctuations at the nozzle exit and the polytropic exponent. The amplitudes of both the pressure of the gases enclosed by the annular liquid membrane and the convergence length increase and decrease, resp., as the amplitude and frequency of the mass flow rate fluctuations at the nozzle exit, resp., are increased. They also increase as the polytropic exponent is increased. (orig.)

  6. Annular Planar Monopole Antennas

    OpenAIRE

    Chen, Z. N.; Ammann, Max; Chia, W.Y. W.; See, T.S. P.

    2002-01-01

    A type of annular planar monopole antenna is presented. The impedance and radiation characteristics of the monopole with different holes and feed gaps are experimentally examined. The measured results demonstrate that the proposed antenna is capable of providing significantly broad impedance bandwidth with acceptable radiation performance.

  7. Hyper-systolic matrix multiplication

    NARCIS (Netherlands)

    Lippert, Th.; Petkov, N.; Palazzari, P.; Schilling, K.

    2001-01-01

    A novel parallel algorithm for matrix multiplication is presented. It is based on a 1-D hyper-systolic processor abstraction. The procedure can be implemented on all types of parallel systems. (C) 2001 Elsevier Science B,V. All rights reserved.

  8. Diagnostic accuracy and variability of three semi-quantitative methods for assessing right ventricular systolic function from cardiac MRI in patients with acquired heart disease

    International Nuclear Information System (INIS)

    To evaluate the diagnostic accuracy and variability of 3 semi-quantitative (SQt) methods for assessing right ventricular (RV) systolic function from cardiac MRI in patients with acquired heart disease: tricuspid annular plane systolic excursion (TAPSE), RV fractional-shortening (RVFS) and RV fractional area change (RVFAC). Sixty consecutive patients were enrolled. Reference RV ejection fraction (RVEF) was determined from short axis cine sequences. TAPSE, RVFS and RVFAC were measured on a 4-chamber cine sequence. All SQt analyses were performed twice by 3 observers with various degrees of training in cardiac MRI. Correlation with RVEF, intra- and inter-observer variability, and receiver operating characteristic (ROC) curve analysis were performed for each SQt method. Correlation between RVFAC and RVEF was good for all observers and did not depend on previous cardiac MRI experience (R range = 0.716-0.741). Conversely, RVFS (R range = 0.534-0.720) and TAPSE (R range = 0.482-0.646) correlated less with RVEF and depended on previous experience. Intra- and inter-observer variability was much lower for RVFAC than for RVFS and TAPSE. ROC analysis demonstrated that RVFAC <41% could predict a RVEF <45% with 90% sensitivity and 94% specificity. RVFAC appears to be more accurate and reproducible than RVFS and TAPSE for SQt assessment of RV function by cardiac MRI. (orig.)

  9. Fluxon dynamics in long annular Josephson tunnel junctions

    DEFF Research Database (Denmark)

    Martucciello, N.; Mygind, Jesper; Koshelets, V.P.; Shchukin, A.V.; Filippenko, L.; Monaco, R

    1998-01-01

    Single-fluxon dynamics has been experimentally investigated in high-quality Nb/Al-AlOx/Nb annular Josephson tunnel junctions having a radius much larger than the Josephson penetration depth. Strong evidence of self-field effects is observed. An external magnetic field in the barrier plane acts on...

  10. Diffractive analysis of annular resonators.

    Science.gov (United States)

    Morin, M; Bélanger, P A

    1992-04-20

    The modal properties of annular resonators are investigated by using an approximate version of the Kirchhoff-Fresnel integral. It is shown that the radial diffraction of a thin annular beam with a large inside radius is similar to that of a cylindrical field distribution. This permits the formal demonstration of the equivalence that exists between large Fresnel number annular resonators and infinite strip resonators. The model explains the properties of annular resonators that have been observed either experimentally or numerically by others, such as the lack of azimuthal discrimination. PMID:20720842

  11. Invasively Measured Aortic Systolic Blood Pressure and Office Systolic Blood Pressure in Cardiovascular Risk Assessment

    DEFF Research Database (Denmark)

    Laugesen, Esben; Knudsen, Søren T; Hansen, Klavs W;

    2016-01-01

    Aortic systolic blood pressure (BP) represents the hemodynamic cardiac and cerebral burden more directly than office systolic BP. Whether invasively measured aortic systolic BP confers additional prognostic value beyond office BP remains debated. In this study, office systolic BP and invasively...

  12. Axisymmetric annular curtain stability

    International Nuclear Information System (INIS)

    A temporal stability analysis was carried out to investigate the stability of an axially moving viscous annular liquid jet subject to axisymmetric disturbances in surrounding co-flowing viscous gas media. We investigated in this study the effects of inertia, surface tension, the gas-to-liquid density ratio, the inner-to-outer radius ratio and the gas-to-liquid viscosity ratio on the stability of the jet. With an increase in inertia, the growth rate of the unstable disturbances is found to increase. The dominant (or most unstable) wavenumber decreases with increasing Reynolds number for larger values of the gas-to-liquid viscosity ratio. However, an opposite tendency for the most unstable wavenumber is predicted for small viscosity ratio in the same inertia range. The surrounding gas density, in the presence of viscosity, always reduces the growth rate, hence stabilizing the flow. There exists a critical value of the density ratio above which the flow becomes stable for very small viscosity ratio, whereas for large viscosity ratio, no stable flow appears in the same range of the density ratio. The curvature has a significant destabilizing effect on the thin annular jet, whereas for a relatively thick jet, the maximum growth rate decreases as the inner radius increases, irrespective of the surrounding gas viscosity. The degree of instability increases with Weber number for a relatively large viscosity ratio. In contrast, for small viscosity ratio, the growth rate exhibits a dramatic dependence on the surface tension. There is a small Weber number range, which depends on the viscosity ratio, where the flow is stable. The viscosity ratio always stabilizes the flow. However, the dominant wavenumber increases with increasing viscosity ratio. The range of unstable wavenumbers is affected only by the curvature effect. (paper)

  13. Far-field Diffraction Properties of Annular Walsh Filters

    Directory of Open Access Journals (Sweden)

    Pubali Mukherjee

    2013-01-01

    Full Text Available Annular Walsh filters are derived from the rotationally symmetric annular Walsh functions which form a complete set of orthogonal functions that take on values either +1 or −1 over the domain specified by the inner and outer radii of the annulus. The value of any annular Walsh function is taken as zero from the centre of the circular aperture to the inner radius of the annulus. The three values 0, +1, and −1 in an annular Walsh function can be realized in a corresponding annular Walsh filter by using transmission values of zero amplitude (i.e., an obscuration, unity amplitude and zero phase, and unity amplitude and phase, respectively. Not only the order of the Walsh filter but also the size of the inner radius of the annulus provides an additional degree of freedom in tailoring of point spread function by using these filters for pupil plane filtering in imaging systems. In this report, we present the far-field amplitude characteristics of some of these filters to underscore their potential for effective use in several demanding applications like high-resolution microscopy, optical data storage, microlithography, optical encryption, and optical micromanipulation.

  14. Annular Hybrid Rocket Motor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Engineers at SpaceDev have conducted a preliminary design and analysis of a proprietary annular design concept for a hybrid motor. A U.S. Patent application has...

  15. Manufacture of annular cermet articles

    Science.gov (United States)

    Forsberg, Charles W.; Sikka, Vinod K.

    2004-11-02

    A method to produce annular-shaped, metal-clad cermet components directly produces the form and avoids multiple fabrication steps such as rolling and welding. The method includes the steps of: providing an annular hollow form with inner and outer side walls; filling the form with a particulate mixture of ceramic and metal; closing, evacuating, and hermetically sealing the form; heating the form to an appropriate temperature; and applying force to consolidate the particulate mixture into solid cermet.

  16. Fluxon dynamics in long annular Josephson tunnel junctions

    OpenAIRE

    Martucciello, N.; Mygind, Jesper; Koshelets, V. P.; Shchukin, A. V.; Filippenko, L.; Monaco, R.

    1998-01-01

    Single-fluxon dynamics has been experimentally investigated in high-quality Nb/Al-AlOx/Nb annular Josephson tunnel junctions having a radius much larger than the Josephson penetration depth. Strong evidence of self-field effects is observed. An external magnetic field in the barrier plane acts on the fluxon as a periodic potential and lowers its average speed. Further, the results of perturbative calculations do not fit the experimental current-voltage profile and, provided the temperature is...

  17. The homology systole of hyperbolic Riemann surfaces

    OpenAIRE

    Parlier, Hugo

    2010-01-01

    The main goal of this note is to show that the study of closed hyperbolic surfaces with maximum length systole is in fact the study of surfaces with maximum length homological systole. The same result is shown to be true for once-punctured surfaces, and is shown to fail for surfaces with a large number of cusps.

  18. Adiabatic Steam-Water Annular Flow in an Annular Geometry

    DEFF Research Database (Denmark)

    Andersen, P. S.; Würtz, J.

    1981-01-01

    Experimental results for fully developed steam-water annular flow in annular geometries are presented. Rod and tube film flow rates and axial pressure gradients were measured for mass fluxes between 500 and 2000 kg/m2s, steam qualities between 20 and 60 per cent and pressures ranging from 3 to 9...... MPa. It was found that the measured tube film flow rate per unit tube perimeter is always many times greater than the corresponding rod film flow rate. Possible explanations for this asymmetry are discussed....

  19. Phase flow rate measurements of annular flows

    OpenAIRE

    Al-Yarubi, Qahtan

    2010-01-01

    In the international oil and gas industry multiphase annular flow in pipelines and wells is extremely important, but not well understood. This thesis reports the development of an efficient and cheap method for measuring the phase flow rates in two phase annular and annular mist flow, in which the liquid phase is electrically conducting, using ultrasonic and conductance techniques. The method measures changes in the conductance of the liquid film formed during annular flow and uses these to c...

  20. Subcutaneous granuloma annulare: radiologic appearance

    International Nuclear Information System (INIS)

    Objective. Granuloma annulare is an uncommon benign inflammatory dermatosis characterized by the formation of dermal papules with a tendency to form rings. There are several clinically distinct forms. The subcutaneous form is the most frequently encountered by radiologists, with the lesion presenting as a superficial mass. There are only a few scattered reports of the imaging appearance of this entity in the literature. We report the radiologic appearance of five cases of subcutaneous granuloma annulare. Design and patients. The radiologic images of five patients (three male, two female) with subcutaneous granuloma annulare were retrospectively studied. Mean patient age was 6.4 years (range, 2-13 years). The lesions occurred in the lower leg (two), foot, forearm, and hand. MR images were available for all lesions, gadolinium-enhanced imaging in three cases, radiographs in four, and bone scintigraphy in one. Results. Radiographs showed unmineralized nodular masses localized to the subcutaneous adipose tissue. The size range, in greatest dimension on imaging studies, was 1-4 cm. MR images show a mass with relatively decreased signal intensity on all pulse sequences, with variable but generally relatively well defined margins. There was extensive diffuse enhancement following gadolinium administration. Conclusion. The radiologic appearance of subcutaneous granuloma annulare is characteristic, typically demonstrating a nodular soft-tissue mass involving the subcutaneous adipose tissue. MR images show a mass with relatively decreased signal intensity on all pulse sequences and variable but generally well defined margins. There is extensive diffuse enhancement following gadolinium administration. Radiographs show a soft-tissue mass or soft-tissue swelling without evidence of bone involvement or mineralization. This radiologic appearance in a young individual is highly suggestive of subcutaneous granuloma annulare. (orig.)

  1. Laser-induced retinal damage thresholds for annular retinal beam profiles

    Science.gov (United States)

    Kennedy, Paul K.; Zuclich, Joseph A.; Lund, David J.; Edsall, Peter R.; Till, Stephen; Stuck, Bruce E.; Hollins, Richard C.

    2004-07-01

    The dependence of retinal damage thresholds on laser spot size, for annular retinal beam profiles, was measured in vivo for 3 μs, 590 nm pulses from a flashlamp-pumped dye laser. Minimum Visible Lesion (MVL)ED50 thresholds in rhesus were measured for annular retinal beam profiles covering 5, 10, and 20 mrad of visual field; which correspond to outer beam diameters of roughly 70, 160, and 300 μm, respectively, on the primate retina. Annular beam profiles at the retinal plane were achieved using a telescopic imaging system, with the focal properties of the eye represented as an equivalent thin lens, and all annular beam profiles had a 37% central obscuration. As a check on experimental data, theoretical MVL-ED50 thresholds for annular beam exposures were calculated using the Thompson-Gerstman granular model of laser-induced thermal damage to the retina. Threshold calculations were performed for the three experimental beam diameters and for an intermediate case with an outer beam diameter of 230 μm. Results indicate that the threshold vs. spot size trends, for annular beams, are similar to the trends for top hat beams determined in a previous study; i.e., the threshold dose varies with the retinal image area for larger image sizes. The model correctly predicts the threshold vs. spot size trends seen in the biological data, for both annular and top hat retinal beam profiles.

  2. Annular-Efficient Triangulations of 3-manifolds

    CERN Document Server

    Jaco, William

    2011-01-01

    A triangulation of a compact 3-manifold is annular-efficient if it is 0-efficient and the only normal, incompressible annuli are thin edge-linking. If a compact 3-manifold has an annular-efficient triangulation, then it is irreducible, boundary-irreducible, and an-annular. Conversely, it is shown that for a compact, irreducible, boundary-irreducible, and an-annular 3-manifold, any triangulation can be modified to an annular-efficient triangulation. It follows that for a manifold satisfying this hypothesis, there are only a finite number of boundary slopes for incompressible and boundary-incompressible surfaces of a bounded Euler characteristic.

  3. Non-approximate method for designing annular field of two-mirror concentric system

    Institute of Scientific and Technical Information of China (English)

    Yuanshen Huang; Dongyue Zhu; Baicheng Li; Dawei Zhang; Zhengji Ni; Songlin Zhuang

    2012-01-01

    Annular field aberrations of a three-reflection concentric system, which are composed of two spherical mirrors, are analyzed. An annular field with a high level of aberration correction exists near the position where the principal ray is perpendicular to the object-image plane. Aberrations are determined by the object height and aperture angle. In this letter, the general expression of the system aberration is derived using the geometric method, and the non-approximate design method is proposed to calculate the radii of the annular fields that have minimum aberrations under different aperture angles. The closer to 0.5 (the ratio of the radius of convex mirror to the radius of concave mirror) is, the smaller the system aberration is. The examples analyzed by LABVIEW indicate that the annular field designed by the proposed method has the smallest aberration in a given system.%Annular field aberrations of a three-reflection concentric system,which are composed of two spherical mirrors,are analyzed.An annular field with a high level of aberration correction exists near the position where the principal ray is perpendicular to the object-image plane.Aberrations are determined by the object height and aperture angle.In this letter,the general expression of the system aberration is derived using the geometric method,and the non-approximate design method is proposed to calculate the radii of the annular fields that have minimum aberrations under different aperture angles.The closer to 0.5 (the ratio of the radius of convex mirror to the radius of concave mirror) is,the smaller the system aberration is.The examples analyzed by LABVIEW indicate that the annular field designed by the proposed method has the smallest aberration in a given system.

  4. Left Ventricular Regional Systolic Function in Patient with Hypertrophic Cardiomyopathy by Quantitative Tissue Velocity Imaging

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The left ventricular regional systolic functions in patients with hypertrophic cardiomyopathy (HCM) were assessed by using quantitative tissue velocity imaging (QTVI). Left ventricular (LV) regional myocardial velocity along long- and short-axis in 31 HCM patients and 20 healthy subjects were analyzed by QTVI, and the regional myocardial systolic peak velocities (MVS) were measured. Mean MVS at each level including mitral annular, basal, middle and apical segments were calculated. The ratio of MVS along long-axis to that along short-axis (Ri) at basal and middle segments of the LV posterior wall and ventricular septum were calculated. The results showed that mean MVS was slower at each level including mitral annular, basal, middle and apical segments in the HCM patients than that in the healthy subjects (P<0.01). There were no significant differences in mean MVS between obstructive and non-obstructive groups in HCM patients. MVS of all regional myocardial segments along long-axis in the HCM patients were significantly slower than that in the healthy subjects (P<0. 05), but there was no significant difference in MVS of all regional myocardial segments along long-axis between hypertrophied and non-hypertrophied group in the HCM patients. Ri was significantly lower in the HCM patients than that in the healthy subjects. The LV regional myocardial contractility along long-axis was impaired not only in the hypertrophied wall but also in the non-hypertrophied one in patients with HCM, suggesting that QTVI can assess accurately LV regional systolic function in patient with HCM and provides a novel means for an early diagnosis before and independent of hypertrophy.

  5. CFD Simulation of Annular Centrifugal Extractors

    OpenAIRE

    Vedantam, S.; Wardle, K. E.; Tamhane, T. V.; Ranade, V. V.; Joshi, J. B.

    2012-01-01

    Annular centrifugal extractors (ACE), also called annular centrifugal contactors offer several advantages over the other conventional process equipment such as low hold-up, high process throughput, low residence time, low solvent inventory and high turn down ratio. The equipment provides a very high value of mass transfer coefficient and interfacial area in the annular zone because of the high level of power consumption per unit volume and separation inside the rotor due to the high g of cent...

  6. Granuloma annulare in herpes zoster scars.

    Science.gov (United States)

    Ohata, C; Shirabe, H; Takagi, K; Kawatsu, T

    2000-03-01

    A 54-year-old Japanese female developed granuloma annulare twice in herpes zoster scars. Soon after the second event, she developed ulcerative colitis, which was well controlled by sulfonamides and corticosteroid suppository. She had no history of diabetes mellitus. There was no recurrence of granuloma annulare by June of 1999. Granuloma annulare might have contributed to the complications of ulcerative colitis, although this had not been noticed before. PMID:10774142

  7. Guided Wave Annular Array Sensor Design for Improved Tomographic Imaging

    Science.gov (United States)

    Koduru, Jaya Prakash; Rose, Joseph L.

    2009-03-01

    Guided wave tomography for structural health monitoring is fast emerging as a reliable tool for the detection and monitoring of hotspots in a structure, for any defects arising from corrosion, crack growth etc. To date guided wave tomography has been successfully tested on aircraft wings, pipes, pipe elbows, and weld joints. Structures practically deployed are subjected to harsh environments like exposure to rain, changes in temperature and humidity. A reliable tomography system should take into account these environmental factors to avoid false alarms. The lack of mode control with piezoceramic disk sensors makes it very sensitive to traces of water leading to false alarms. In this study we explore the design of annular array sensors to provide mode control for improved structural tomography, in particular, addressing the false alarm potential of water loading. Clearly defined actuation lines in the phase velocity dispersion curve space are calculated. A dominant in-plane displacement point is found to provide a solution to the water loading problem. The improvement in the tomographic images with the annular array sensors in the presence of water traces is clearly illustrated with a series of experiments. An annular array design philosophy for other problems in NDE/SHM is also discussed.

  8. Absolute photonic band gap in 2D honeycomb annular photonic crystals

    International Nuclear Information System (INIS)

    Highlights: • A two-dimensional honeycomb annular photonic crystal (PC) is proposed. • The absolute photonic band gap (PBG) is studied. • Annular PCs show larger PBGs than usual air-hole PCs for high refractive index. • Annular PCs with anisotropic rods show large PBGs for low refractive index. • There exist optimal parameters to open largest band gaps. - Abstract: Using the plane wave expansion method, we investigate the effects of structural parameters on absolute photonic band gap (PBG) in two-dimensional honeycomb annular photonic crystals (PCs). The results reveal that the annular PCs possess absolute PBGs that are larger than those of the conventional air-hole PCs only when the refractive index of the material from which the PC is made is equal to 4.5 or larger. If the refractive index is smaller than 4.5, utilization of anisotropic inner rods in honeycomb annular PCs can lead to the formation of larger PBGs. The optimal structural parameters that yield the largest absolute PBGs are obtained

  9. Systematic comparison of the use of annular and Zernike circle polynomials for annular wavefronts

    NARCIS (Netherlands)

    Mahajan, V.N.; Aftab, M.

    2010-01-01

    The theory of wavefront analysis of a noncircular wavefront is given and applied for a systematic comparison of the use of annular and Zernike circle polynomials for the analysis of an annular wavefront. It is shown that, unlike the annular coefficients, the circle coefficients generally change as t

  10. Prognostic value of systolic short-term blood pressure variability in systolic heart failure

    OpenAIRE

    Berry, Matthieu; Lairez, Olivier; Fourcade, Joelle; Roncalli, Jérôme; Carrié, Didier; Pathak, Atul; Chamontin, Bernard; Galinier, Michel

    2016-01-01

    Background Traditional cardiovascular risk factors in the general population are usually correlated to a better prognosis in patients with chronic heart failure (HF). Most of the studies show that blood pressure variability (BPV) has noxious effect on general population but data are missing for patients with systolic HF. The aim of this study was to assess the prognostic impact of short-term blood pressure variability (BPV) in systolic HF. Methods and results We retrospectively studied 288 pa...

  11. Soliton bunching in annular Josephson junctions

    DEFF Research Database (Denmark)

    Vernik, I.V; Lazarides, Nickos; Sørensen, Mads Peter;

    1996-01-01

    By studying soliton (fluxon) motion in long annular Josephson junctions it is possible to avoid the influence of the boundaries and soliton-soliton collisions present in linear junctions. A new experimental design consisting of a niobium coil placed on top of an annular junction has been used to...

  12. Bistability and hysteresis of annular impinging jets

    Science.gov (United States)

    Tisovsky, Tomas

    2016-06-01

    In present study, the bistability and hysteresis of annular impinging jets is investigated. Annular impinging jets are simulated using open source CFD code - OpenFOAM. Both flow field patterns of interest are obtained and hysteresis is found by means of dynamic mesh simulation. Effect of nozzle exit velocity on resulting hysteresis loop is also illustrated.

  13. Hyperellipticity and Systoles of Klein Surfaces

    CERN Document Server

    Katz, Mikhail G

    2012-01-01

    Given a hyperelliptic Klein surface, we construct companion Klein bottles, extending our technique of companion tori already exploited by the authors in the genus 2 case. Bavard's short loops on such companion surfaces are studied in relation to the original surface so to improve a systolic inequality of Gromov's. A basic idea is to use length bounds for loops on a companion Klein bottle, and then analyze how curves transplant to the original nonorientable surface. We exploit the real structure on the orientable double cover by applying the coarea inequality to the distance function from the real locus. Of particular interest is the case of Dyck's surface. We also exploit an optimal systolic bound for the M\\"obius band, due to Blatter.

  14. Systolic heart failure: a prothrombotic state

    DEFF Research Database (Denmark)

    de Peuter, Olav R; Kok, Wouter E M; Torp-Pedersen, Christian; Büller, Harry R; Kamphuisen, Pieter W

    2009-01-01

    Systolic heart failure is a common syndrome whose incidence is expected to increase. Several treatment modalities, such as beta-blockers and angiotensin-converting enzyme inhibitors, improve survival. Whether antithrombotic treatment is effective remains to be elucidated, although observations...... suggest a prothrombotic state in heart failure. This article focuses on this prothrombotic state and discusses the risk of thromboembolic events, pathophysiological mechanisms, and the potential role of anticoagulant treatment....

  15. Systolic blood pressure and systolic hypertension in adolescence of atomic bomb survivors exposed in utero.

    Science.gov (United States)

    Nakashima, Eiji; Akahoshi, Masazumi; Neriishi, Kazuo; Fujiwara, Saeko

    2007-11-01

    Annual medical examinations were conducted during adolescence for the in utero clinical study sample subjects exposed prenatally to the atomic bombs in Hiroshima and Nagasaki. Systolic blood pressure and several anthropometric measurements were recorded during these examinations. For 1014 persons exposed in utero, two types of longitudinal analyses were performed, for a total of 7029 observations (6.93 observations per subject) of systolic blood pressure (continuous data) and systolic hypertension (binary data) for persons aged 9 to 19 years. Body mass index (BMI) and/or body weight were considered in the analyses as potential confounders. For the measurements of systolic blood pressure, the common dose effect was 2.09 mmHg per Gy and was significant (P = 0.017). The dose by trimester interaction was suggestive (P = 0.060). A significant radiation dose effect was found in the second trimester (P = 0.001), with an estimated 4.17 mmHg per Gy, but in the first and third trimesters, radiation dose effects were not significant (P > 0.50). For prevalence of systolic hypertension, the radiation dose effect was significant (P = 0.009); the odds ratio at 1 Gy was 2.23 [95% confidence interval (CI): 1.23, 4.04], and the dose by trimester interaction was not significant (P = 0.778). The dose response of systolic hypertension had no dose threshold, with a threshold point estimate of 0 Gy (95% CI: <0.0, 1.1 Gy). The dose response for systolic blood pressure was most pronounced in the second trimester, the most active organogenesis period for the organs relevant to blood pressure. PMID:17973553

  16. Treatment of anemia with darbepoetin alfa in systolic heart failure

    DEFF Research Database (Denmark)

    Swedberg, Karl; Young, James B; Anand, Inder S;

    2013-01-01

    Patients with systolic heart failure and anemia have worse symptoms, functional capacity, and outcomes than those without anemia. We evaluated the effects of darbepoetin alfa on clinical outcomes in patients with systolic heart failure and anemia.......Patients with systolic heart failure and anemia have worse symptoms, functional capacity, and outcomes than those without anemia. We evaluated the effects of darbepoetin alfa on clinical outcomes in patients with systolic heart failure and anemia....

  17. Etizolam-induced superficial erythema annulare centrifugum.

    Science.gov (United States)

    Kuroda, K; Yabunami, H; Hisanaga, Y

    2002-01-01

    Erythema annulare centrifugum (EAC) is characterized by slowly enlarging annular erythematous lesions. Although the origin is not clear in most cases, EAC has been associated with infections, medications, and in rare cases, underlying malignancy. We describe a patient who developed annular erythematous lesions after etizolam administration. The eruptions were typical of the superficial form of EAC, both clinically and histopathologically. The lesions disappeared shortly after discontinuation of the medication. Patch testing with etizolam gave positive results. To our knowledge this is the first reported case of etizolam-induced superficial EAC. PMID:11952667

  18. Divergent Field Annular Ion Engine Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed work investigates an approach that would allow an annular ion engine geometry to achieve ion beam currents approaching the Child-Langmuir limit. In...

  19. Effects of Everolimus-Eluting Stents on the Left Ventricular Systolic and Diastolic Functions

    Directory of Open Access Journals (Sweden)

    MohammadSadegh Parsaee

    2015-10-01

    Full Text Available Background: The drug-eluting stent (DES decreases the rate of coronary restenosis and re-obstruction. The aim of this study was to assess prospectively the effectiveness of the new generation DES on the left ventricular (LV systolic and diastolic functions in patients with isolated severe proximal left anterior descending (LAD coronary artery stenosis.Methods: A prospective study was conducted on 50 patients with isolated severe proximal LAD stenosis. Successful percutaneous coronary intervention (PCI with Everolimus-eluting stents was performed for the whole study population. All the patients underwent transthoracic echocardiography within 24 hours before and one month after PCI, and LV systolic and diastolic parameters were compared before and after PCI using the paired samples t-test.Results: The mean age of the study population was 57.68 ± 8.82 years. Within the study population, 26 (52% patients were male and 24 (48% were female. There was a significant 10.6% and 5.2% increase in the early diastolic mitral annular motion (e' and the LV ejection fraction following PCI, respectively (p value = 0.005 and p value = 0.044, respectively. Before PCI, wall motion abnormality was seen in 2.21 ± 2.91 segments, which significantly decreased to 1.49 ± 2.58 segments (p value = 0.04 after the procedure. Also, the wall motion score index was 1.18 ± 0.26 before PCI, which significantly decreased to 1.13 ± 0.23 after PCI (p value < 0.001.Also, there was a trend toward a higher ratio of transmitral peak early diastolic velocity to peak late diastolic velocity after PCI (p value = 0.068.Conclusion: Our study showed that the use of the Everolimus-eluting stents improved the LV systolic and diastolic functions in patients with isolated severe LAD stenosis.

  20. An L-Band, Circularly Polarized, Dual-Feed, Cavity-Backed Annular Slot Antenna with Wide-Angle Coverage

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2006-01-01

    An L-band, circularly polarized, dual-feed, cavity-backed annular slot antenna has been investigated. The investigations comprise parametric studies of design parameters and measurements with different ground planes. The antenna has an impedance bandwidth of 6% around 1.59 GHz and a maximum...

  1. An L-Band, Circularly Polarized, Dual-Feed, Cavity-Backed Annular Slot Antenna with Wide-Angle Coverage

    OpenAIRE

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2006-01-01

    An L-band, circularly polarized, dual-feed, cavity-backed annular slot antenna has been investigated. The investigations comprise parametric studies of design parameters and measurements with different ground planes. The antenna has an impedance bandwidth of 6% around 1.59 GHz and a maximum directivity of about 7 dBi.

  2. An L-Band, Circularly Polarised, Dual-Feed, Cavity-Backed Annular Slot Antenna For Phased-Array Applications

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2006-01-01

    The results of a parametric study for the development of an L-band, circularly polarised, dual-feed, cavity-backed annular slot antenna is presented. The study included detailed numerical simulations and measurements on a prototype with different ground planes, to assess the antenna’s applicability...... as an element in a small phased array antenna....

  3. Liquid Encapsulation in Parylene Microstructures Using Integrated Annular-Plate Stiction Valves

    OpenAIRE

    Gutierrez, Christian A.; Ellis Meng

    2011-01-01

    We report the design, fabrication and characterization of micromachined Parylene structures for self-sealing liquid encapsulation applications. Automatic sealing is enabled through the use of an integrated annular-plate stiction valve which greatly reduces device footprint over in-plane configurations. We achieve automatic wafer-level liquid entrapment without using adhesives or processing at elevated pressures or temperatures. The ability to track changes to the internal liquid volume throug...

  4. Optical systolic solutions of linear algebraic equations

    Science.gov (United States)

    Neuman, C. P.; Casasent, D.

    1984-01-01

    The philosophy and data encoding possible in systolic array optical processor (SAOP) were reviewed. The multitude of linear algebraic operations achievable on this architecture is examined. These operations include such linear algebraic algorithms as: matrix-decomposition, direct and indirect solutions, implicit and explicit methods for partial differential equations, eigenvalue and eigenvector calculations, and singular value decomposition. This architecture can be utilized to realize general techniques for solving matrix linear and nonlinear algebraic equations, least mean square error solutions, FIR filters, and nested-loop algorithms for control engineering applications. The data flow and pipelining of operations, design of parallel algorithms and flexible architectures, application of these architectures to computationally intensive physical problems, error source modeling of optical processors, and matching of the computational needs of practical engineering problems to the capabilities of optical processors are emphasized.

  5. Management of Patients With Recovered Systolic Function.

    Science.gov (United States)

    Basuray, Anupam; Fang, James C

    2016-01-01

    Advancements in the treatment of heart failure (HF) with systolic dysfunction have given rise to a new population of patients with improved ejection fraction (EF). The management of this distinct population is not well described due to a lack of consensus on the definition of myocardial recovery, a scarcity of data on the natural history of these patients, and the absence of focused clinical trials. Moreover, an improvement in EF may have different prognostic and management implications depending on the underlying etiology of cardiomyopathy. This can be challenging for the clinician who is approached by a patient inquiring about a reduction of medical therapy after apparent EF recovery. This review explores management strategies for HF patients with recovered EF in a disease-specific format. PMID:26796969

  6. Two-phase flow instabilities in a vertical annular channel

    Energy Technology Data Exchange (ETDEWEB)

    Babelli, I.; Nair, S.; Ishii, M. [Purdue Univ., West Lafayette, IN (United States)

    1995-09-01

    An experimental test facility was built to study two-phase flow instabilities in vertical annular channel with emphasis on downward flow under low pressure and low flow conditions. The specific geometry of the test section is similar to the fuel-target sub-channel of the Savannah River Site (SRS) Mark 22 fuel assembly. Critical Heat Flux (CHF) was observed following flow excursion and flow reversal in the test section. Density wave instability was not recorded in this series of experimental runs. The results of this experimental study show that flow excursion is the dominant instability mode under low flow, low pressure, and down flow conditions. The onset of instability data are plotted on the subcooling-Zuber (phase change) numbers stability plane.

  7. Dynamic Response of Three-Layered Annular Plate with Imperfections

    Directory of Open Access Journals (Sweden)

    Pawlus Dorota

    2015-02-01

    Full Text Available This paper presents the imperfection sensitivity of annular plate with three-layered structure. The plate composed of thin elastic facings and a thicker elastic core is loaded in facing plane. The classical issue of a three-layered plate was solved for dynamic deflection problem using the approximation methods: orthogonalization and finite difference. The solution includes the axisymmetric and asymmetric plate modes of the dynamic stability loss. The evaluation of the rate of plate sensitivity to imperfection of plate preliminary geometry has been enriched by the analysis of plate models built of finite elements. The ABAQUS program has been used. The numerous calculation results in the form of deflection characteristics, buckling modes, values of critical parameters create the view of response of dynamic plate structure with different rate of imperfection and linear in time loading growth, too.

  8. Graphs of Large Girth and Surfaces of Large Systole

    OpenAIRE

    Petri, Bram; Walker, Alexander

    2015-01-01

    The systole of a hyperbolic surface is bounded by a logarithmic function of its genus. This bound is sharp, in that there exist sequences of surfaces with genera tending to infinity that attain logarithmically large systoles. These are constructed by taking congruence covers of arithmetic surfaces. In this article we provide a new construction for a sequence of surfaces with systoles that grow logarithmically in their genera. We do this by combining a construction for graphs of large girth an...

  9. CFD Simulation of Annular Centrifugal Extractors

    Directory of Open Access Journals (Sweden)

    S. Vedantam

    2012-01-01

    Full Text Available Annular centrifugal extractors (ACE, also called annular centrifugal contactors offer several advantages over the other conventional process equipment such as low hold-up, high process throughput, low residence time, low solvent inventory and high turn down ratio. The equipment provides a very high value of mass transfer coefficient and interfacial area in the annular zone because of the high level of power consumption per unit volume and separation inside the rotor due to the high g of centrifugal field. For the development of rational and reliable design procedures, it is important to understand the flow patterns in the mixer and settler zones. Computational Fluid Dynamics (CFD has played a major role in the constant evolution and improvements of this device. During the past thirty years, a large number of investigators have undertaken CFD simulations. All these publications have been carefully and critically analyzed and a coherent picture of the present status has been presented in this review paper. Initially, review of the single phase studies in the annular region has been presented, followed by the separator region. In continuation, the two-phase CFD simulations involving liquid-liquid and gas-liquid flow in the annular as well as separator regions have been reviewed. Suggestions have been made for the future work for bridging the existing knowledge gaps. In particular, emphasis has been given to the application of CFD simulations for the design of this equipment.

  10. Annular bilayer magnetoelectric composites: theoretical analysis.

    Science.gov (United States)

    Guo, Mingsen; Dong, Shuxiang

    2010-01-01

    The laminated bilayer magnetoelectric (ME) composites consist of magnetostrictive and piezoelectric layers are known to have giant ME coefficient due to the high coupling efficiency in bending mode. In our previous report, the bar-shaped bilayer composite has been investigated by using a magnetoelectric-coupling equivalent circuit. Here, we propose an annular bilayer ME composite, which consists of magnetostrictive and piezoelectric rings. This composite has a much lower resonance frequency of bending mode compared with its radial mode. In addition, the annular bilayer ME composite is expected to respond to vortex magnetic field as well as unidirectional magnetic field. In this paper, we investigate the annular bilayer ME composite by using impedance-matrix method and predict the ME coefficients as a function of geometric parameters of the composites. PMID:20178914

  11. Stitching algorithm for annular subaperture interferometry

    Institute of Scientific and Technical Information of China (English)

    Xi Hou; Fan Wu; Li Yang; Shibin Wu; Qiang Chen

    2006-01-01

    @@ Annular subaperture interferometry (ASI) has been developed for low cost and flexible test of rotationally symmetric aspheric surfaces, in which accurately combining the subaperture measurement data corrupted by misalignments and noise into a complete surface figure is the key problem. By introducing the Zernike annular polynomials which are orthogonal over annulus, a method that eliminates the coupling problem in the earlier algorithm based on Zernike circle polynomials is proposed. Vector-matrix notation is used to simplify the description and calculations. The performance of this reduction method is evaluated by numerical simulation. The results prove this method with high precision and good anti-noise capability.

  12. Optimal Thrust Vectoring for an Annular Aerospike Nozzle Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent success of an annular aerospike flight test by NASA Dryden has prompted keen interest in providing thrust vector capability to the annular aerospike nozzle...

  13. Exercise training in older patients with systolic heart failure

    DEFF Research Database (Denmark)

    Prescott, Eva; Hjardem-Hansen, Rasmus; Dela, Flemming; Teisner, Ane S; Nielsen, Henrik

    2009-01-01

    Training improves exercise capacity in patients with heart failure (CHF) but most evidence is on selected younger patients with systolic CHF.......Training improves exercise capacity in patients with heart failure (CHF) but most evidence is on selected younger patients with systolic CHF....

  14. Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure

    DEFF Research Database (Denmark)

    Køber, Lars; Thune, Jens J; Nielsen, Jens C;

    2016-01-01

    Background The benefit of an implantable cardioverter-defibrillator (ICD) in patients with symptomatic systolic heart failure caused by coronary artery disease has been well documented. However, the evidence for a benefit of prophylactic ICDs in patients with systolic heart failure that is not due...

  15. A New Annular Shear Piezoelectric Accelerometer

    DEFF Research Database (Denmark)

    Liu, Bin; Kriegbaum, B.

    2000-01-01

    This paper describes the construction and performance of a recently introduced Annular Shear piezoelectric accelerometer, Type 4511. The design has insulated and double-shielded case. The accelerometer housing is made of stainless steel, AISI 316L. Piezoceramic PZ23 is used. The seismic mass...

  16. Azimuthally forced flames in an annular combustor

    Science.gov (United States)

    Worth, Nicholas; Dawson, James; Mastorakos, Epaminondas

    2015-11-01

    Thermoacoustic instabilities are more likely to occur in lean burn combustion systems, making their adoption both difficult and costly. At present, our knowledge of such phenomena is insufficient to produce an inherently stable combustor by design, and therefore an improved understanding of these instabilities has become the focus of a significant research effort. Recent experimental and numerical studies have demonstrated that the symmetry of annular chambers permit a range of self-excited azimuthal modes to be generated in annular geometry, which can make the study of isolated modes difficult. While acoustic forcing is common in single flame experiments, no equivalent for forced azimuthal modes in an annular chamber have been demonstrated. The present investigation focuses on the novel application of acoustic forcing to a laboratory scale annular combustor, in order to generate azimuthal standing wave modes at a prescribed frequency and amplitude. The results focus on the ability of the method to isolate the mode of oscillation using experimental pressure and high speed OH* measurements. The successful excitation of azimuthal modes demonstrated represents an important step towards improving our fundamental understanding of this phenomena in practically relevant geometry.

  17. Quaternion hermitian planes

    OpenAIRE

    Stroppel, Markus

    1993-01-01

    The quaternion hermitian planes are defined, and are characterized by certain groups of automorphisms. For this purpose, characterizations of locally compact connected translation planes (in the context of stable planes) and compact connected projective desarguesian planes are given.

  18. Management of Periocular Granuloma Annulare Using Topical Dapsone

    Science.gov (United States)

    Patel, Mayha; Shitabata, Paul; Horowitz, David

    2015-01-01

    Granuloma annulare is a disease characterized by granulomatous inflammation of the dermis. Localized granuloma annulare may resolve spontaneously, while generalized granuloma annulare may persist for decades. The authors present the case of a 41-year-old Hispanic man with a two-week history of periocular granuloma annulare. Due to previously reported success in the use of systemic dapsone for the treatment of granuloma annulare, and the periocular proximity of the patient’s lesion, topical dapsone was used for treatment. Various additional therapies for the management of granuloma annulare have been reported, such as topical and systemic steroids, isotretinoin, pentoxifylline, cyclosporine, Interferon gamma, potassium iodide, nicotinamide, niacinamide, salicylic acid, fumaric acid ester, etanercept, infliximab, and hydroxychloroquine. Additional clinical trials are necessary to further evaluate the effectiveness of topical dapsone in the management of granuloma annulare. PMID:26203321

  19. Montgomery Modular Multiplication on Reconfigurable Hardware: Systolic versus Multiplexed Implementation

    OpenAIRE

    Guilherme Perin; Daniel Gomes Mesquita; João Baptista Martins

    2011-01-01

    This paper describes a comparison of two Montgomery modular multiplication architectures: a systolic and a multiplexed. Both implementations target FPGA devices. The modular multiplication is employed in modular exponentiation processes, which are the most important operations of some public-key cryptographic algorithms, including the most popular of them, the RSA. The proposed systolic architecture presents a high-radix implementation with a one-dimensional array of Processing Elements. The ...

  20. Risk following hospitalization in stable chronic systolic heart failure

    DEFF Research Database (Denmark)

    Abrahamsson, Putte; Swedberg, Karl; Borer, Jeffrey S; Böhm, Michael; Kober, Lars; Komajda, Michel; Lloyd, Suzanne M; Metra, Marco; Tavazzi, Luigi; Ford, Ian

    2013-01-01

    We explored the impact of being hospitalized due to worsening heart failure (WHF) or a myocardial infarction (MI) on subsequent mortality in a large contemporary data set of patients with stable chronic systolic heart failure (HF).......We explored the impact of being hospitalized due to worsening heart failure (WHF) or a myocardial infarction (MI) on subsequent mortality in a large contemporary data set of patients with stable chronic systolic heart failure (HF)....

  1. Arrhythmias and electrocardiographic changes in systolic heart failure

    OpenAIRE

    Ashok Devkota; Ahmed Bakhit; Alix Dufresne; Aung Naing Oo; Premraj Parajuli; Saveena Manhas

    2016-01-01

    Background: Heart failure is a common condition that that leads to hospitalization. It is associated with various atrial and ventricular arrhythmias. Aim: The aim of this study is to find common arrhythmias and electrocardiographic changes in hospitalized patients who have systolic heart failure. Materials and Methods: This is a retrospective study of medical records, and electrocardiograms (EKGs) of 157 patients admitted to our hospital who had systolic heart failure with ejection fraction (...

  2. Non newtonian annular alloy solidification in mould

    Energy Technology Data Exchange (ETDEWEB)

    Moraga, Nelson O.; Garrido, Carlos P. [Universidad de La Serena, Departamento de Ingenieria Mecanica, La Serena (Chile); Castillo, Ernesto F. [Universidad de Santiago de Chile, Departamento de Ingenieria Mecanica, Santiago (Chile)

    2012-08-15

    The annular solidification of an aluminium-silicon alloy in a graphite mould with a geometry consisting of horizontal concentric cylinders is studied numerically. The analysis incorporates the behavior of non-Newtonian, pseudoplastic (n=0.2), Newtonian (n=1), and dilatant (n=1.5) fluids. The fluid mechanics and heat transfer coupled with a transient model of convection diffusion are solved using the finite volume method and the SIMPLE algorithm. Solidification is described in terms of a liquid fraction of a phase change that varies linearly with temperature. The final results make it possible to infer that the fluid dynamics and heat transfer of solidification in an annular geometry are affected by the non-Newtonian nature of the fluid, speeding up the process when the fluid is pseudoplastic. (orig.)

  3. Performance of annular high frequency thermoacoustic engines

    Science.gov (United States)

    Rodriguez, Ivan A.

    This thesis presents studies of the behavior of miniature annular thermoacoustic prime movers and the imaging of the complex sound fields using PIV inside the small acoustic wave guides when driven by a temperature gradient. Thermoacoustic engines operating in the standing wave mode are limited in their acoustic efficiency by a high degree of irreversibility that is inherent in how they work. Better performance can be achieved by using traveling waves in the thermoacoustic devices. This has led to the development of an annular high frequency thermoacoustic prime mover consisting of a regenerator, which is a random stack in-between a hot and cold heat exchanger, inside an annular waveguide. Miniature devices were developed and studied with operating frequencies in the range of 2-4 kHz. This corresponds to an average ring circumference of 11 cm for the 3 kHz device, the resonator bore being 6 mm. A similar device of 11 mm bore, length of 18 cm was also investigated; its resonant frequency was 2 kHz. Sound intensities as high as 166.8 dB were generated with limited heat input. Sound power was extracted from the annular structure by an impedance-matching side arm. The nature of the acoustic wave generated by heat was investigated using a high speed PIV instrument. Although the acoustic device appears symmetric, its performance is characterized by a broken symmetry and by perturbations that exist in its structure. Effects of these are observed in the PIV imaging; images show axial and radial components. Moreover, PIV studies show effects of streaming and instabilities which affect the devices' acoustic efficiency. The acoustic efficiency is high, being of 40% of Carnot. This type of device shows much promise as a high efficiency energy converter; it can be reduced in size for microcircuit applications.

  4. Annular Alopecia Areata: Report of Two Cases

    OpenAIRE

    Bansal, Manish; Manchanda, Kajal; Pandey, SS

    2013-01-01

    Alopecia areata (AA) is an auto-immune disorder characterized by the appearance of non-scarring bald patches affecting the hair bearing areas of the body. Scalp is the most common site of involvement. AA can affect any age group. The usual pattern of the hair loss is oval or round. We hereby, report two cases of annular and circinate pattern of AA due to its unusual morphology.

  5. Annular pancreas associated with duodenal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Enrico; Bronnimann; Silke; Potthast; Tatjana; Vlajnic; Daniel; Oertli; Oleg; Heizmann

    2010-01-01

    Annular pancreas (AP) is a rare congenital anomaly. Coexisting malignancy has been reported only in a few cases. We report what is, to the best of our knowledge, the first case in the English literature of duodenal adenocarcinoma in a patient with AP. In a 55-year old woman with duodenal outlet stenosis magnetic resonance cholangiopancreatography showed an aberrant pancreatic duct encircling the duodenum. Duodenojejunostomy was performed. Eight weeks later she presented with painless jaundice. Duodenopancre...

  6. Vibration analysis of annular-like plates

    Science.gov (United States)

    Cheng, L.; Li, Y. Y.; Yam, L. H.

    2003-05-01

    The existence of eccentricity of the central hole for an annular plate results in a significant change in the natural frequencies and mode shapes of the structure. In this paper, the vibration analysis of annular-like plates is presented based on numerical and experimental approaches. Using the finite element analysis code Nastran, the effects of the eccentricity, hole size and boundary condition on vibration modes are investigated systematically through both global and local analyses. The results show that analyses for perfect symmetric conditions can still roughly predict the mode shapes of "recessive" modes of the plate with a slightly eccentric hole. They will, however, lead to erroneous results for "dominant" modes. In addition, the residual displacement mode shape is verified as an effective parameter for identifying damage occurring in plate-like structures. Experimental modal analysis on a clamped-free annular-like plate is performed, and the results obtained reveal good agreement with those obtained by numerical analysis. This study provides guidance on modal analysis, vibration measurement and damage detection of plate-like structures.

  7. Effect of Annular Slit Geometry on Characteristics of Spiral Jet

    Institute of Scientific and Technical Information of China (English)

    Shigeru Matsuo; Kwon-Hee Lee; Shinsuke Oda; Toshiaki Setoguchi; Heuy-Dong Kim

    2003-01-01

    A spiral flow using an annular slit connected to a conical cylinder does not need special device to generate a tangential velocity component of the flow and differs from swirling flows. Pressurized fluid is supplied to an annular chamber and injected into the convergent nozzle through the annular slit. The annular jet develops into the spiral flow. In the present study, a spiral jet discharged out of nozzle exit was obtained by using a convergent nozzle and an annular slit set in nozzle inlet, and the effect of annular slit geometry on characteristics of the spiral jet was investigated by using a Laser Doppler Velocimeter (LDV) experimentally. Furthermore, velocity distributions of the spiral jet were compared with those of a normal jet.

  8. Ultrasonogrphic diagnosis of snapping annular ligament in the elbow

    Energy Technology Data Exchange (ETDEWEB)

    Chai, Jee Won; Kim Su Jin; Lim, Hyun Kyong; Bae, Kee Jeong [SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2015-01-15

    Elbow snapping by annular ligament is rare and may be difficult to diagnose, when this Epub ahead of print condition is not familiar. We report a case of elbow snapping by annular ligament diagnosed by ultrasonography, which was confirmed by arthroscopic observation. The ultrasonographic findings were thickening of the annular ligament and snapping in and out of the radiocapitellar joint during elbow flexion and extension on dynamic ultrasonography.

  9. Liquid Encapsulation in Parylene Microstructures Using Integrated Annular-Plate Stiction Valves

    Directory of Open Access Journals (Sweden)

    Christian A. Gutierrez

    2011-09-01

    Full Text Available We report the design, fabrication and characterization of micromachined Parylene structures for self-sealing liquid encapsulation applications. Automatic sealing is enabled through the use of an integrated annular-plate stiction valve which greatly reduces device footprint over in-plane configurations. We achieve automatic wafer-level liquid entrapment without using adhesives or processing at elevated pressures or temperatures. The ability to track changes to the internal liquid volume through the use of electrochemical impedance measurements is also presented.

  10. Laser anemometer measurements in an annular cascade of core turbine vanes and comparison with theory

    Science.gov (United States)

    Goldman, L. J.; Seashultz, R. G.

    1982-01-01

    Laser measurements were made in an annular cascade of stator vanes operating at an exit critical velocity ratio of 0.78. Velocity and flow angles in the blade to blade plane were obtained at every 10 percent of axial chord within the passage and at 1/2 axial chord downstream of the vanes for radial positions near the hub, mean and tip. Results are presented in both plot and tabulated form and are compared with calculations from an inviscid, quasi three dimensional computer program. The experimental measurements generally agreed well with these theoretical calculations, an indication of the usefulness of this analytic approach.

  11. Granuloma annulare localized to the shaft of the penis

    DEFF Research Database (Denmark)

    Trap, R; Wiebe, B

    1993-01-01

    A case of granuloma annulare localized to the shaft of the penis is reported. The differential diagnoses are discussed. Penile granuloma annulare is a rare disorder and it is concluded that biopsies of penile lesions are recommended to verify the correct diagnosis.......A case of granuloma annulare localized to the shaft of the penis is reported. The differential diagnoses are discussed. Penile granuloma annulare is a rare disorder and it is concluded that biopsies of penile lesions are recommended to verify the correct diagnosis....

  12. 3-D Velocity Estimation for Two Planes in vivo

    DEFF Research Database (Denmark)

    Holbek, Simon; Pihl, Michael Johannes; Ewertsen, Caroline;

    2014-01-01

    3-D velocity vectors can provide additional flow information applicable for diagnosing cardiovascular diseases e.g. by estimating the out-of-plane velocity component. A 3-D version of the Transverse Oscillation (TO) method has previously been used to obtain this information in a carotid flow...... stored on the experimental scanner SARUS. The full 3-D velocity profile can be created and examined at peak-systole and end-diastole without ECG gating in two planes. Maximum out-of-plane velocities for the three peak-systoles and end-diastoles were 68.5 5.1 cm/s and 26.3 3.3 cm/s, respectively. In the...... longitudinal plane, average maximum peak velocity in flow direction was 65.2 14.0 cm/s at peak-systole and 33.6 4.3 cm/s at end-diastole. A commercial BK Medical ProFocus UltraView scanner using a spectral estimator gave 79.3 cm/s and 14.6 cm/s for the same volunteer. This demonstrates that real-time 3-D...

  13. Thread-annular flow in vertical pipes

    Science.gov (United States)

    Frei, Ch.; Lüscher, P.; Wintermantel, E.

    2000-05-01

    Thread injection is a promising method for different minimally invasive medical applications. This paper documents an experimental study dealing with an axially moving thread in annular pipe flow. Mass flow and axial force on the thread are measured for a 0.46 mm diameter thread in pipes with diameters between 0.55 and 1.35 mm. The experiments with thread velocities of up to 1.5 ms[minus sign]1 confirm the findings of theoretical studies that for clinical requirements the radius ratio between thread and pipe is crucial for the adjustments of mass ow and force on the thread.

  14. Deep variant of Erythema Annulare Centrifugum

    OpenAIRE

    Ahu Yorulmaz; Ferda Artuz; Devrim Tuba Unal

    2014-01-01

    A 29-year-old woman came to our outpatient clinic with a several-month history of itchy red lesions over her trunk. There was no family history and past history of any other diseases or medication. Dermatological examination revealed annular and oval-shaped plaques up to several cm’s in size, one of which was polycyclic in configuration, on back of the patient (Fig. 1). It was also noticed that lesions had erythematous indurated bordes with paler central areas (Fig. 1).

  15. Deep variant of Erythema Annulare Centrifugum

    Directory of Open Access Journals (Sweden)

    Ahu Yorulmaz

    2014-10-01

    Full Text Available A 29-year-old woman came to our outpatient clinic with a several-month history of itchy red lesions over her trunk. There was no family history and past history of any other diseases or medication. Dermatological examination revealed annular and oval-shaped plaques up to several cm’s in size, one of which was polycyclic in configuration, on back of the patient (Fig. 1. It was also noticed that lesions had erythematous indurated bordes with paler central areas (Fig. 1.

  16. Visualization of the annular synthetic jet

    Czech Academy of Sciences Publication Activity Database

    Broučková, Zuzana; Trávníček, Zdeněk; Šafařík, Pavel

    Praha: Ústav termomechaniky AV ČR, v. v. i, 2012 - (Šimurda, D.; Kozel, K.), s. 13-16 ISBN 978-80-87012-40-6. [Topical Problems of Fluid Mechanics 2012. Praha (CZ), 15.02.2012-17.02.2012] R&D Projects: GA AV ČR(CZ) IAA200760801; GA ČR(CZ) GCP101/11/J019 Institutional research plan: CEZ:AV0Z20760514 Keywords : synthetic jet * annular jet * visualization Subject RIV: BK - Fluid Dynamics

  17. Wave turbulence in annular wave tank

    Science.gov (United States)

    Onorato, Miguel; Stramignoni, Ettore

    2014-05-01

    We perform experiments in an annular wind wave tank at the Dipartimento di Fisica, Universita' di Torino. The external diameter of the tank is 5 meters while the internal one is 1 meter. The tank is equipped by two air fans which can lead to a wind of maximum 5 m/s. The present set up is capable of studying the generation of waves and the development of wind wave spectra for large duration. We have performed different tests including different wind speeds. For large wind speed we observe the formation of spectra consistent with Kolmogorv-Zakharov predictions.

  18. Interfacial friction in cocurrent upward annular flow

    Science.gov (United States)

    Hossfeld, L. M.; Bharathan, D.; Wallis, G. B.; Richter, H. J.

    1982-03-01

    Cocurrent upward annular flow is investigated, with an emphasis on correlating and predicting pressure drop. Attention is given to the characteristics of the liquid flow in the film, and the interaction of the core with the film. Alternate approaches are discussed for correlating suitably defined interfacial friction factors. Both approaches are dependent on knowledge of the entrainment in order to make predictions. Dimensional analysis is used to define characteristic parameters of the flow and an effort is made to determine, to the extent possible, the influences of these parameters on the interfacial friction factor.

  19. Air-water countercurrent annular flow

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, D.

    1979-09-01

    Countercurrent annular flow of air and water in circular tubes of diameters ranging from 6.4 to 152 mm is investigated. Experimental measurements include liquid fraction, pressure gradients and countercurrent gas and liquid fluxes. Influences of tube end geometries on the countercurrent fluxes are isolated. Analogies between countercurrent flow, open channel flow, and compressible flow are established. Interfacial momentum transfer between the phases are characterized by empirical friction factors. The dependence of interfacial friction factors on tube diameter is shown to yield a basis for extending the present results to larger tubes.

  20. Annular diffraction of very unstable light nuclei

    International Nuclear Information System (INIS)

    Because they are brittle, unstable light nuclei can produce an annular diffraction pattern observed on their decay products with large cross sections. With such a simple model, the 9Li angular distribution observed in the 11Li fragmentation have been reproduced together with the reaction cross-section and the fragmentation yield provided recoil effects from neutron emission are included. It results that for this projectile and for light targets, diffraction is the main source of transverse momentum for 9Li whereas for neutrons it originates from its emission energy in the 11Li center of mass

  1. Air-water countercurrent annular flow

    International Nuclear Information System (INIS)

    Countercurrent annular flow of air and water in circular tubes of diameters ranging from 6.4 to 152 mm is investigated. Experimental measurements include liquid fraction, pressure gradients and countercurrent gas and liquid fluxes. Influences of tube end geometries on the countercurrent fluxes are isolated. Analogies between countercurrent flow, open channel flow, and compressible flow are established. Interfacial momentum transfer between the phases are characterized by empirical friction factors. The dependence of interfacial friction factors on tube diameter is shown to yield a basis for extending the present results to larger tubes

  2. FFT Computation with Systolic Arrays, A New Architecture

    Science.gov (United States)

    Boriakoff, Valentin

    1994-01-01

    The use of the Cooley-Tukey algorithm for computing the l-d FFT lends itself to a particular matrix factorization which suggests direct implementation by linearly-connected systolic arrays. Here we present a new systolic architecture that embodies this algorithm. This implementation requires a smaller number of processors and a smaller number of memory cells than other recent implementations, as well as having all the advantages of systolic arrays. For the implementation of the decimation-in-frequency case, word-serial data input allows continuous real-time operation without the need of a serial-to-parallel conversion device. No control or data stream switching is necessary. Computer simulation of this architecture was done in the context of a 1024 point DFT with a fixed point processor, and CMOS processor implementation has started.

  3. Atrial systole enhances intraventricular filling flow propagation during increasing heart rate.

    Science.gov (United States)

    Santhanakrishnan, Arvind; Okafor, Ikechukwu; Kumar, Gautam; Yoganathan, Ajit P

    2016-02-29

    Diastolic fluid dynamics in the left ventricle (LV) has been examined in multiple clinical studies for understanding cardiac function in healthy humans and developing diagnostic measures in disease conditions. The question of how intraventricular filling vortex flow pattern is affected by increasing heart rate (HR) is still unanswered. Previous studies on healthy subjects have shown a correlation between increasing HR and diminished E/A ratio of transmitral peak velocities during early filling (E-wave) to atrial systole (A-wave). We hypothesize that with increasing HR under constant E/A ratio, E-wave contribution to intraventricular vortex propagation is diminished. A physiologic in vitro flow phantom consisting of a LV physical model was used for this study. HR was varied across 70, 100 and 120 beats per minute (bpm) with E/A of 1.1-1.2. Intraventricular flow patterns were characterized using 2D particle image velocimetry measured across three parallel longitudinal (apical-basal) planes in the LV. A pair of counter-rotating vortices was observed during E-wave across all HRs. With increasing HR, diminished vortex propagation occurred during E-wave and atrial systole was found to amplify secondary vorticity production. The diastolic time point where peak vortex circulation occurred was delayed with increasing HR, with peak circulation for 120bpm occurring as late as 90% into diastole near the end of A-wave. The role of atrial systole is elevated for higher HR due to the limited time available for filling. Our baseline findings and analysis approach can be applied to studies of clinical conditions where impaired exercise tolerance is observed. PMID:26895781

  4. Euclid Squares on Infinite Planes

    OpenAIRE

    W.B.Vasantha Kandasamy; Ilanthenral, K.; Florentin Smarandache

    2015-01-01

    In this book for the first time the authors study the new type of Euclid squares in various planes like real plane, complex plane, dual number plane, special dual like number plane and special quasi dual number plane.

  5. Scintigraphic prediction of pulmonary arterial systolic pressure by regional right ventricular ejection fraction during the second half of systole

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, B.J.; Holman, B.L.

    1982-11-01

    In 49 patients in whom gated equilibrium ventriculography and cardiac catheterization were performed within a 6 day interval, total and fractional portions of global and regional right ventricular ejection fraction (RVEF) were correlated with pulmonary arterial systolic pressure. Pulmonary arterial systolic pressure was normal (30 mm Hg or less) in 27 patients (Group I) and elevated (31 mm Hg or greater) in 22 patients (Group II). The second-half regional RVEF was 38 +/- 8% (mean +/- standard deviation) with a range of 30 to 54% for Group I and 22 +/- 6% with a range of 13 to 32% for Group II. The difference between the means was statistically significant (p less than 0.001). Use of a second-half regional RVEF of 30% as the criterion of elevated pulmonary arterial systolic pressure resulted in a sensitivity of 0.86 and a specificity of 1.00. A power curve fit in which pulmonary arterial systolic pressure . 10.91 (second-half regional RVEF)-0.87 allowed accurate estimation (r . -0.85) of pulmonary arterial systolic pressure from the second-half regional RVEF. It is concluded that second-half regional RVEF may be used to accurately detect pulmonary arterial hypertension and to estimate its extent.

  6. Arrhythmias and electrocardiographic changes in systolic heart failure

    Directory of Open Access Journals (Sweden)

    Ashok Devkota

    2016-01-01

    Full Text Available Background: Heart failure is a common condition that that leads to hospitalization. It is associated with various atrial and ventricular arrhythmias. Aim: The aim of this study is to find common arrhythmias and electrocardiographic changes in hospitalized patients who have systolic heart failure. Materials and Methods: This is a retrospective study of medical records, and electrocardiograms (EKGs of 157 patients admitted to our hospital who had systolic heart failure with ejection fraction (EF 35%. Twelve-lead EKG of these patients was studied to identify common arrhythmia and demographic variables; laboratory results were compared to identify the differences. Results: A total of 157 patients with systolic heart failure, 63.7% had an EF ≤ 35%. Hypertension 82.8%, diabetes 49%, coronary artery disease 40.8%, chronic obstructive pulmonary disease or bronchial asthma 22.3%, and stroke 12.1% were common associated co-morbidities. On analysis of EKG, 28.6% had tachycardia, 21.9% had prolonged PR > 200 ms, 16.3% had wide QRS > 120 ms, 70.7% had prolonged corrected QT (QTc, and 42.2% had left axis deviation. The most common arrhythmias were sinus tachycardia and atrial fibrillation/flutter which were found in 14.6% and 13.4%, respectively. The left ventricular hypertrophy was a common abnormality found in 22.4% followed by ventricular premature contractions 18.4%, atrial premature contractions 9.5%, and left bundle branch block 6.1%. Patients with severe systolic heart failure had prolonged QRS (P = 0.02 and prolonged QTc (P = 0.01 as compared to the other group. Conclusions: Sinus tachycardia and atrial fibrillation/flutter were common arrhythmias in patients with systolic heart failure. Patients with severe systolic heart failure had statistically significant prolongation of the QRS duration and QTc interval.

  7. Efficient linear systolic array for the knapsack problem

    OpenAIRE

    Andonov, Rumen; Quinton, Patrice

    1992-01-01

    A processor-efficient systolic algorithm for the dynamic programming approach to the knapsack problem is presented in this paper. The algorithm is implemented on a linear systolic array where the number of cells q, the cell memory storage a and the input/output requirements are design parameters. These are independent of the problem size given by the number of the objects m and the knapsack capacity c. The time complexity of the algorithm is Q(mc/q+m) and both the time speedup and the process...

  8. Construction of hyperbolic Riemann surfaces with large systoles

    OpenAIRE

    Akrout, Hugo; Muetzel, Bjoern

    2013-01-01

    Let $S$ be a compact hyperbolic Riemann surface of genus $g \\geq 2$. We call a systole a shortest simple closed geodesic in $S$ and denote by $\\mathop{sys}(S)$ its length. Let $\\mathop{msys(g)}$ be the maximal value that $\\mathop{sys}(\\cdot)$ can attain among the compact Riemann surfaces of genus $g$. We call a (globally) maximal surface $S_{max}$ a compact Riemann surface of genus $g$ whose systole has length $\\mathop{msys}(g)$. In Section 2 we use cutting and pasting techniques to construct...

  9. Detonation diffraction from an annular channel

    Science.gov (United States)

    Meredith, James; Ng, Hoi Dick; Lee, John H. S.

    2010-12-01

    In this study, gaseous detonation diffraction from an annular channel was investigated with a streak camera and the critical pressure for transmission of the detonation wave was obtained. The annular channel was used to approximate an infinite slot resulting in cylindrically expanding detonation waves. Two mixtures, stoichiometric acetylene-oxygen and stoichiometric acetylene-oxygen with 70% Ar dilution, were tested in a 4.3 and 14.3 mm channel width ( W). The undiluted and diluted mixtures were found to have values of the critical channel width over the cell size around 3 and 12 respectively. Comparing these results to values of the critical diameter ( d c ), in which a spherical detonation occurs, a value of critical d c / W c near 2 is observed for the highly diluted mixture. This value corresponds to the geometrical factor of the curvature term between a spherical and cylindrical diverging wave. Hence, the result is in support of Lee's proposed mechanism [Lee in Dynamics of Exothermicity, pp. 321, Gordon and Breach, Amsterdam, 1996] for failure due to diffraction based on curvature in stable mixtures such as those highly argon diluted with very regular detonation cellular patterns.

  10. Annular beam shaping and optical trepanning

    Science.gov (United States)

    Zeng, Danyong

    Percussion drilling and trepanning are two laser drilling methods. Percussion drilling is accomplished by focusing the laser beam to approximately the required diameter of the hole, exposing the material to one or a series of laser pulses at the same spot to melt and vaporize the material. Drilling by trepanning involves cutting a hole by rotating a laser beam with an optical element or an x-y galvo-scanner. Optical trepanning is a new laser drilling method using an annular beam. The annular beams allow numerous irradiance profiles to supply laser energy to the workpiece and thus provide more flexibility in affecting the hole quality than a traditional circular laser beam. Heating depth is important for drilling application. Since there are no good ways to measure the temperature inside substrate during the drilling process, an analytical model for optical trepanning has been developed by considering an axisymmetric, transient heat conduction equation, and the evolutions of the melting temperature isotherm, which is referred to as the melt boundary in this study, are calculated to investigate the influences of the laser pulse shapes and intensity profiles on the hole geometry. This mathematical model provides a means of understanding the thermal effect of laser irradiation with different annular beam shapes. To take account of conduction in the solid, vaporization and convection due to the melt flow caused by an assist gas, an analytical two-dimensional model is developed for optical trepanning. The influences of pulse duration, laser pulse length, pulse repetition rate, intensity profiles and beam radius are investigated to examine their effects on the recast layer thickness, hole depth and taper. The ray tracing technique of geometrical optics is employed to design the necessary optics to transform a Gaussian laser beam into an annular beam of different intensity profiles. Such profiles include half Gaussian with maximum intensities at the inner and outer

  11. 75 FR 23582 - Annular Casing Pressure Management for Offshore Wells

    Science.gov (United States)

    2010-05-04

    ... Recommended Practice (RP) 90. As explained in API RP 90, Section 3, Annular Casing Pressure Management Program... Institute's Recommended Practice for managing annular casing pressure. New regulations are needed because... Continental Shelf lessees to follow best industry practices for wells with sustained casing pressure....

  12. Obtention of an empirical equation for annular channels

    International Nuclear Information System (INIS)

    Using a trial circuit, the experimental heat transfer coefficient is determined, in forced convection at one phase only within an annular channel in which water flows ascendantly and for this reason an empirical equation is determined. This work tries to contribute to the understanding of the forced convection phenomena in non tubular geometries like the annular channels. (Author)

  13. Limited Diffraction Maps for Pulsed Wave Annular Arrays

    DEFF Research Database (Denmark)

    Fox, Paul D.

    2002-01-01

    A procedure is provided for decomposing the linear field of flat pulsed wave annular arrays into an equivalent set of known limited diffraction Bessel beams. Each Bessel beam propagates with known characteristics, enabling good insight into the propagation of annular fields to be obtained...

  14. Effect of annular secondary conductor in a linear electromagnetic stirrer

    Indian Academy of Sciences (India)

    R Madhavan; V Ramanarayanan

    2008-10-01

    This paper presents the variation of average axial force density in the annular secondary conductor of a linear electromagnetic stirrer. Different geometries of secondaries are considered for numerical and experimental validation namely, 1. hollow annular ring, 2. annular ring with a solid cylinder and 3. solid cylinder. Experimental and numerical simulations are performed for a 2-pole in house built 15 kW linear electromagnetic stirrer (EMS). It is observed for a supply current of 200 A at 30 Hz the force densities in the hollow annular ring is 67% higher than the equivalent solid cylinder. The same values are 33% for annular ring with a solid cylinder. Force density variation with supply frequency and current are also reported. Numerical simulations using finite element model are validated with experimental results.

  15. Dyssynchronous electrical and mechanical systole in patients with cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens H; Fuglsang, Stefan; Bendtsen, Flemming;

    2002-01-01

    BACKGROUND/AIMS: Previous investigations have shown a prolonged QT interval in some patients with cirrhosis. The aim of this study was to investigate the relation between electrical and mechanical systole in patients with different degrees of severity of cirrhosis. METHODS: Forty-eight patients w...... addition these patients have alterations in the cardiac excitation-contraction relation with compromised association between electrical and mechanical function.......BACKGROUND/AIMS: Previous investigations have shown a prolonged QT interval in some patients with cirrhosis. The aim of this study was to investigate the relation between electrical and mechanical systole in patients with different degrees of severity of cirrhosis. METHODS: Forty-eight patients...... direct relation between QT and time of mechanical systole (tS) was observed in controls (r=0.58, P<0.01), and cirrhotic patients (r=0.44, P<0.002). In patients with a prolonged QTc interval, the difference between electrical and mechanical systole time was substantially longer than in patients with a...

  16. Birth weight and systolic blood pressure in adolescence and adulthood

    DEFF Research Database (Denmark)

    Gamborg, Michael; Byberg, Liisa; Rasmussen, Finn;

    2007-01-01

    The authors investigated the shape, sex- and age-dependency, and possible confounding of the association between birth weight and systolic blood pressure (SBP) in 197,954 adults from 20 Nordic cohorts (birth years 1910-1987), one of which included 166,249 Swedish male conscripts. Random...

  17. Concordance and reproducibility between M-mode, tissue Doppler imaging, and two-dimensional strain imaging in the assessment of mitral annular displacement and velocity in patients with various heart conditions

    DEFF Research Database (Denmark)

    de Knegt, Martina Chantal; Biering-Sorensen, Tor; Sogaard, Peter;

    2014-01-01

    AIMS: Mitral annular (MA) displacement reflects longitudinal left ventricular (LV) deformation and systolic velocity measurements reflect the rate of contraction; both are valuable in the diagnosis and prognosis of cardiac disease. The aim of this study was to test the agreement and reproducibility...... between motion mode (M-mode), colour tissue Doppler imaging (TDI), and two-dimensional strain imaging (2DSI) when measuring MA displacement and systolic velocity. METHODS AND RESULTS: Using GE Healthcare Vivid 7 and E9 and Echopac BT11 software, MA displacement and velocity measurements by 2DSI, TDI, and...... inter-observer variability were tested using the Bland-Altman method in 125 patients. A relatively low bias between M-mode and TDI with respect to MA displacement (mean difference ± 1.96 standard deviation: 0.08 ± 0.35 cm) and a low bias between TDI and 2DSI with respect to MA peak systolic velocity (-0...

  18. Automatic noninvasive measurement of systolic blood pressure using photoplethysmography

    Directory of Open Access Journals (Sweden)

    Glik Zehava

    2009-10-01

    Full Text Available Abstract Background Automatic measurement of arterial blood pressure is important, but the available commercial automatic blood pressure meters, mostly based on oscillometry, are of low accuracy. Methods In this study, we present a cuff-based technique for automatic measurement of systolic blood pressure, based on photoplethysmographic signals measured simultaneously in fingers of both hands. After inflating the pressure cuff to a level above systolic blood pressure in a relatively slow rate, it is slowly deflated. The cuff pressure for which the photoplethysmographic signal reappeared during the deflation of the pressure-cuff was taken as the systolic blood pressure. The algorithm for the detection of the photoplethysmographic signal involves: (1 determination of the time-segments in which the photoplethysmographic signal distal to the cuff is expected to appear, utilizing the photoplethysmographic signal in the free hand, and (2 discrimination between random fluctuations and photoplethysmographic pattern. The detected pulses in the time-segments were identified as photoplethysmographic pulses if they met two criteria, based on the pulse waveform and on the correlation between the signal in each segment and the signal in the two neighboring segments. Results Comparison of the photoplethysmographic-based automatic technique to sphygmomanometry, the reference standard, shows that the standard deviation of their differences was 3.7 mmHg. For subjects with systolic blood pressure above 130 mmHg the standard deviation was even lower, 2.9 mmHg. These values are much lower than the 8 mmHg value imposed by AAMI standard for automatic blood pressure meters. Conclusion The photoplethysmographic-based technique for automatic measurement of systolic blood pressure, and the algorithm which was presented in this study, seems to be accurate.

  19. Dual-Band Annular-Ring Microstrip Patch Antenna for Satellite Applications

    Directory of Open Access Journals (Sweden)

    Tvs Divakar

    2014-08-01

    Full Text Available A dual-band circularly polarized antenna fed by four apertures that covers the bands of GPS, Galileo, is introduced. The ARSAs designed using FR4 substrates in the L and S bands have 3-dB axial-ratio bandwidths (ARBWs of as large as 37% and 52%, respectively, whereas the one using an RT5880 substrate in the L band, 61%. In these 3-dB axial-ratio bands, impedance matching with VSWR<=1.8 is also achieved. Three wideband planar baluns are used to achieve good axial ratio and VSWR. The results of the annular-ring microstrip antenna show good performance of a dual-band operation, which meets the requirement of Global Navigation Satellite System (GNSS applications.

  20. Facility modernization Annular Core Research Reactor

    International Nuclear Information System (INIS)

    The Annular Core Research Reactor (ACRR) has undergone numerous modifications since its conception in response to program needs. The original reactor fuel, which was special U-ZrH TRIGA fuel designed primarily for pulsing, has been replaced with a higher pulsing capacity BeO fuel. Other advanced operating modes which use this increased capability, in addition to the pulse and steady state, have been incorporated to tailor power histories and fluences to the experiments. Various experimental facilities have been developed that range from a radiography facility to a 50 cm diameter External Fuel Ring Cavity (FREC) using 180 of the original ZrH fuel elements. Currently a digital reactor console is being produced with GA, which will give enhanced monitoring capabilities of the reactor parameters while leaving the safety-related shutdown functions with analog technology. (author)

  1. Hydrodynamics of annular-dispersed flow

    International Nuclear Information System (INIS)

    The interfacial drag, droplet entrainment, and droplet size distributions are important for detailed mechanistic modeling of annular dispersed two-phase flow. In view of this, recently developed correlations for these parameters are presented and discussed in this paper. The drag correlations for multiple fluid particle systems have been developed from a similarity hypothesis based on the mixture viscosity model. The results show that the drag coefficient depends on the particle Reynolds number and droplet concentration. The onset on droplet entrainment significantly alters the mechanisms of mass, momentum, and energy transfer between the film and gas core flow as well as the transfer between the two-phase mixture and the wall. By assuming the roll wave entrainment mechanism, the correlations for the amount of entrained droplet as well as for the droplet size distribution have been obtained from a simple model in collaboration with a large number of data

  2. Lighter and stronger planes

    OpenAIRE

    Attard, Bonnie; Duca, Edward

    2015-01-01

    The price of fuel is a large cost burden on the aerospace industry. A lighter plane means cheaper flights, increased aircraft range, and less environmental pollution. http://www.um.edu.mt/think/lighter-and-stronger-planes/

  3. Recurrent Annular Peripheral Choroidal Detachment after Trabeculectomy

    Directory of Open Access Journals (Sweden)

    Shaohui Liu

    2013-10-01

    Full Text Available We report a challenging case of recurrent flat anterior chamber without hypotony after trabeculectomy in a 54-year-old Black male with a remote history of steroid-treated polymyositis, cataract surgery, and uncontrolled open angle glaucoma. The patient presented with a flat chamber on postoperative day 11, but had a normal fundus exam and intraocular pressure (IOP. Flat chamber persisted despite treatment with cycloplegics, steroids, and a Healon injection into the anterior chamber. A transverse B-scan of the peripheral fundus revealed a shallow annular peripheral choroidal detachment. The suprachoroidal fluid was drained. The patient presented 3 days later with a recurrent flat chamber and an annular peripheral choroidal effusion. The fluid was removed and reinforcement of the scleral flap was performed with the resolution of the flat anterior chamber. A large corneal epithelial defect developed after the second drainage. The oral prednisone was tapered quickly and the topical steroid was decreased. One week later, his vision decreased to count fingers with severe corneal stromal edema and Descemet's membrane folds that improved to 20/50 within 24 h of resumption of the oral steroid and frequent topical steroid. The patient's visual acuity improved to 20/20 following a slow withdrawal of the oral and topical steroid. Eight months after surgery, the IOP was 15 mm Hg without glaucoma medication. The detection of a shallow anterior choroidal detachment by transverse B-scan is critical to making the correct diagnosis. Severe cornea edema can occur if the steroid is withdrawn too quickly. Thus, steroids should be tapered cautiously in steroid-dependent patients.

  4. Annular MHD Physics for Turbojet Energy Bypass

    Science.gov (United States)

    Schneider, Steven J.

    2011-01-01

    The use of annular Hall type MHD generator/accelerator ducts for turbojet energy bypass is evaluated assuming weakly ionized flows obtained from pulsed nanosecond discharges. The equations for a 1-D, axisymmetric MHD generator/accelerator are derived and numerically integrated to determine the generator/accelerator performance characteristics. The concept offers a shockless means of interacting with high speed inlet flows and potentially offers variable inlet geometry performance without the complexity of moving parts simply by varying the generator loading parameter. The cycle analysis conducted iteratively with a spike inlet and turbojet flying at M = 7 at 30 km altitude is estimated to have a positive thrust per unit mass flow of 185 N-s/kg. The turbojet allowable combustor temperature is set at an aggressive 2200 deg K. The annular MHD Hall generator/accelerator is L = 3 m in length with a B(sub r) = 5 Tesla magnetic field and a conductivity of sigma = 5 mho/m for the generator and sigma= 1.0 mho/m for the accelerator. The calculated isentropic efficiency for the generator is eta(sub sg) = 84 percent at an enthalpy extraction ratio, eta(sub Ng) = 0.63. The calculated isentropic efficiency for the accelerator is eta(sub sa) = 81 percent at an enthalpy addition ratio, eta(sub Na) = 0.62. An assessment of the ionization fraction necessary to achieve a conductivity of sigma = 1.0 mho/m is n(sub e)/n = 1.90 X 10(exp -6), and for sigma = 5.0 mho/m is n(sub e)/n = 9.52 X 10(exp -6).

  5. Stability of cantilevered coaxial shells with internal and annular flow

    International Nuclear Information System (INIS)

    This paper is a theoretical study of the stability of cantilevered coaxial cylindrical shells conveying incompressible fluid in the annular space in- between and within the inner shell. The viscous effects of the mean flow are taken into account, but the perturbations of the equilibrium state on the basis of which stability is assessed is carried out by means of potential flow theory, thus neglecting unsteady viscous effects which are known to become important for narrow annular flows. Shell displacements are described by Flugge's equations of motion. Solution of the coupled fluid-structure equations is carried out by means of the Fourier Transform Method. The main finding of this research is that stability is lost by flutter for internal flow, according to both the inviscid and viscous variants of the theory; for annular flow, however, whereas inviscid theory predicts loss of stability by flutter, viscous theory (with dissipative effects included) predicts that the shell loses stability by divergence and then, at appreciably higher flow, by flutter. Reduction of the annular gap generally destabilizes the system; while increased steady viscous effects slightly stabilize the system for internal flow, they strongly destabilize it for annular flow. Increasing the length of the shell destabilizes the system for both internal and annular flows. The presence of internal flow in addition to annular flow tends to stabilize the system vis-a-vis the case of annular flow, but only at low flow velocities, having the opposite effect at higher flows; the same effects arise when the main flow is internal and an annular flow added to the system

  6. Detonation Initiation by Annular Jets and Shock Waves

    OpenAIRE

    Shepherd, Joseph E.

    2005-01-01

    The objective of this research is to experimentally determine the feasibility of initiating detonation in fuel-air mixtures using only the energy in hot, compressed air. The existing 6-inch shock tube at Caltech was used to create hot, high-pressure air behind a reflected shock wave. The hot air created an imploding annular shock wave when it jetted through an annular orifice into a 76-mm-diameter, 1-m-long tube attached to the end of the shock tube. A special test section with an annular ...

  7. LU and Cholesky decomposition on an optical systolic array processor

    Science.gov (United States)

    Casasent, D.; Ghosh, A.

    1983-01-01

    Direct solutions of matrix-vector equations on an optical systolic array processor are considered. The solutions are discussed and a parallel algorithm for LU matrix decomposition that is very attractive for an optical realization is formulated. It is noted that when direct techniques are used, it is preferable to realize the matrix decomposition on an optical system and to utilize a digital processor for the solution of the simplified resultant matrix-vector problem. One method of realizing LU matrix decomposition on a new frequency-multiplexed optical systolic array matrix-matrix processor is described. A simple method for extending the process of LU decomposition to Cholesky decomposition on the optical processor is discussed.

  8. SYSTOLIC BLOOD PRESSURE: BIOPHYSICAL, AGE AND GENDER FEATURES

    Directory of Open Access Journals (Sweden)

    L.I. Malinova

    2008-03-01

    Full Text Available The article is devoted to the study of systolic blood pressure features in the population of large industrial center. On the basis of measurement of blood pressure in adult population of three city regions there were revealed the following age-related changes in systolic blood pressure in men: three periods of rise and two periods of stabilization. The principal difference in women is the absence of the periods of rise and stabilization, lower level of blood pressure in young and middle aged people and authentically higher level of blood pressure - in elderly women. The increase of haemodynamical loading for one year of life in men of the middle (2 times and elder ages (3 times was revealed, that was not typical forwomen.

  9. Modeling Pathologies of Diastolic and Systolic Heart Failure

    OpenAIRE

    Genet, M.; Lee, L. C.; Baillargeon, B; Guccione, J.M.; Kuhl, E.

    2015-01-01

    Chronic heart failure is a medical condition that involves structural and functional changes of the heart and a progressive reduction in cardiac output. Heart failure is classified into two categories: diastolic heart failure, a thickening of the ventricular wall associated with impaired filling; and systolic heart failure, a dilation of the ventricles associated with reduced pump function. In theory, the pathophysiology of heart failure is well understood. In practice, however, heart failure...

  10. [Are there risk factors for pure systolic hypertension?].

    Science.gov (United States)

    Milon, H; Fromage, P; Bruyère, A M; Boissonnat, P; Contassot, J C; Francou, M; Pommier, A; Robert, A

    1987-06-01

    Pure systolic hypertension (PSH) is mainly observed in subjects over 60 years of age, and it is always due to a loss of compliance of the greater arteries. Blood pressure itself is partly responsible for loss of compliance, but other factors have been suggested. We have investigated this matter in a study of 3,388 subjects aged from 20 to 69 years. In a first stage, PSH patients (systolic BP greater than or equal to 160; diastolic BP less than 95 mmHg), aged from 50 to 59 years, were compared with normotensive subjects (systolic BP less than 140; diastolic BP less than 95 mmHg) and with other types of hypertensive patients with regard to cigarette smoking, alcohol consumption, obesity and plasma cholesterol, triglycerides, gamma-GT, glucose and uric acid levels. Several of these variables were significantly higher in all hypertensive patients than in normotensive subjects, but cigarette smoking and gamma-GT levels were predominantly or exclusively higher in PSH patients. In a second stage, correlations between differential BP and the variables listed above were studied in subjects with two levels of diastolic BP: 70-79 and 80-89 mmHg, thus taking into account all degrees between normal BP and PSH proper. Weakly positive correlations were found with alcohol consumption, plasma gamma-GT and glucose levels, and with percentages of smokers or ex-smokers. It is therefore conceivable that in addition to BP itself other factors, such as alcohol consumption, cigarette smoking and hyperglycaemia, contribute to the loss of arterial compliance progressively leading to pure systolic hypertension. PMID:3116968

  11. Design of Linear Systolic Arrays for Matrix Multiplication

    OpenAIRE

    MILOVANOVIC, E. I.; STOJCEV, M. K.; MILOVANOVIC, I. Z.; NIKOLIC, T. R.

    2014-01-01

    This paper presents architecture for matrix multiplication optimized to be integrated as an accelerator unit to a host computer. Two linear systolic arrays with unidirectional data flow (ULSA), used as hardware accelerators, where synthesized in this paper. The solution proposed here is designed to accelerate both the computation and communication by employing hardware address generator units (AGUs). The proposed design has been implemented on Xilinx Spartan-2E and Virtex4 FPG...

  12. Stable relocation of the radial head without annular ligament reconstruction using the Ilizarov technique to treat neglected Monteggia fracture: two case reports

    Directory of Open Access Journals (Sweden)

    Wani Shareef A

    2010-10-01

    Full Text Available Abstract Introduction A Monteggia facture dislocation is not an uncommon injury, and the diagnosis can often be missed. Long-term follow-up of untreated Monteggia fracture dislocations reveals development of premature arthritis, pain, instability, and loss of pronation and supination. Methods involving annular ligament reconstruction require post-operative immobilization and use of transcapitellar pinning for maintenance of reduction, and thus a delay in rehabilitation. The literature reports satisfactory results with methods that involve ulnar osteotomy and open reduction of the radial head without annular ligament reconstruction. We used the Ilizarov method in two cases with neglected Monteggia fracture dislocations to stably reduce the radial head without open reduction and annular ligament reconstruction. Case presentation We report two cases of neglected Monteggia fracture dislocation, in two Kashmiri boys aged four and six years. Using ulnar osteotomy with distraction osteogenesis, we were able to relocate the radial head gradually and maintain the reduction without a requirement for open reduction and annular ligament reconstruction. Conclusion Distraction lengthening and hyperangulation in different planes by use of the Ilizarov technique effectively reduces the radial head without open reduction and annular ligament reconstruction.

  13. Vector flow imaging of the ascending aorta. Are systolic backflow and atherosclerosis related?

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Møller-Sørensen, Hasse; Kjaergaard, Jesper; Jensen, Maiken Brit; Lund, Jens Teglgaard; Nielsen, Michael Bachmann; Jensen, Jørgen Arendt

    2015-01-01

    the ascending aorta in long axis view. The presence of systolic backflow, visualized with TO, was correlated to aortic atherosclerosis, to systolic velocities obtained with transesophageal echocardiography and cardiac output obtained with pulmonary artery catheter thermodilution, to gender, age...

  14. A grillage model for predicting wrinkles in annular graphene under circular shearing

    International Nuclear Information System (INIS)

    This paper is concerned with a Timoshenko grillage model for modeling the wrinkling phenomenon in annular graphene under circular shearing applied at its inner edge. By calibrating the grillage model results against the molecular mechanics (MM) results, the grillage model comprising beams of elliptical cross-section orientated along the carbon-carbon bond has section dimensions of 0.06 nm for the major axis length and 0.036 nm for the minor axis length. Moreover, the beams are connected to one another at 0.00212 nm from the geometric centric. This eccentric connection of beams allows the proposed grillage model to cater for the cross-couplings among bonds that produce the out-of-plane wrinkling pattern. The out-of-plane to in-plane bending stiffnesses' ratio is 0.36, and the cross bending stiffness provided by the ellipse eccentricity is 0.025 times that of the in-plane bending stiffness. Besides furnishing identical wave numbers as well as amplitudes and wavelengths that are in good agreement with MM results, the grillage model can capture wrinkling patterns with a boundary layer, whereas plate and membrane models could not mimic the boundary layer.

  15. Assessment of Inner Channel Blockage on the Annular Fuel Rod

    Energy Technology Data Exchange (ETDEWEB)

    Shin, C. H.; In, W. K.; Oh, D. S.; Chun, T. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    A dual-cooled annular fuel for a pressurized water reactor (PWR) has been introduced for a significant amount of reactor power uprate. The Korea Atomic Energy Research Institute (KAERI) has been performing a research to develop a dual-cooled annular fuel for the power uprate of 20% in an optimized PWR in Korea, OPR1000. An inner channel blockage is principal one of technical issues of the annular fuel rod. The inner channel in an annular fuel is isolated from the neighbor channels unlike the outer channels. The inner channel will be faced with a DNB accident by the partial blockage. In this paper, the largest fractional channel blockage was assessed by subchannel analysis code MATRA-AF and an end plug design to complement inlet blockage of inner channel was estimated by CFD code, CFD-ACE

  16. Annular linear induction pump with an externally supported duct

    International Nuclear Information System (INIS)

    An annular linear induction pump of increased efficiency is described, capable of being readily disassembled for repair or replacement of parts, and having one pass flow of the liquid metal through the pump. (U.K.)

  17. Principle of radial transport in low temperature annular plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yunchao, E-mail: yunchao.zhang@anu.edu.au; Charles, Christine; Boswell, Rod [Space Plasma, Power and Propulsion Laboratory, Research School of Physics and Engineering, The Australian National University, Bldg 60, Mills Road, Australian Capital Territory 2601 (Australia)

    2015-07-15

    Radial transport in low temperature annular plasmas is investigated theoretically in this paper. The electrons are assumed to be in quasi-equilibrium due to their high temperature and light inertial mass. The ions are not in equilibrium and their transport is analyzed in three different situations: a low electric field (LEF) model, an intermediate electric field (IEF) model, and a high electric field (HEF) model. The universal IEF model smoothly connects the LEF and HEF models at their respective electric field strength limits and gives more accurate results of the ion mobility coefficient and effective ion temperature over the entire electric field strength range. Annular modelling is applied to an argon plasma and numerical results of the density peak position, the annular boundary loss coefficient and the electron temperature are given as functions of the annular geometry ratio and Paschen number.

  18. Annular elastolytic giant cell granuloma in association with Hashimoto's thyroiditis

    OpenAIRE

    Rishi Hassan; P Arunprasath; Padmavathy, L.; K Srivenkateswaran

    2016-01-01

    Annular elastolytic giant cell granuloma (AEGCG) is a rare granulomatous skin disease characterized clinically by annular plaques with elevated borders and atrophic centers found mainly on sun-exposed skin and histologically by diffuse granulomatous infiltrates composed of multinucleated giant cells, histiocytes and lymphocytes in the dermis along with phagocytosis of elastic fibers by multinucleated giant cells. We report a case of AEGCG in a 50-year-old woman and is highlighted for the clas...

  19. Annular bright and dark field imaging of soft materials

    International Nuclear Information System (INIS)

    Here polyethylene, as an example of an important soft material, was studied by STEM annular bright and dark field. The contrast as function of the probe size/shape and the detector collection angle are discussed. The results are compared to conventional bright field transmission electron microscopy, electron energy filtered imaging and energy dispersive spectroscopy mapping. Annular bright and dark field gave a higher contrast than conventional transmission and analytical mapping techniques

  20. Interfacial friction in low flowrate vertical annular flow

    International Nuclear Information System (INIS)

    During boil-off and reflood transients in nuclear reactors, the core liquid inventory and inlet flowrate are largely determined by the interfacial friction in the reactor core. For these transients, annular flow occurs at relatively modest liquid flowrates and at the low heat fluxes typical of decay heat conditions. The resulting low vapor Reynolds numbers, are out of the data range used to develop the generally accepted interfacial friction relations for annular flow. In addition, most existing annular flow data comes from air/liquid adiabatic experiments with fully developed flows. By contrast, in a reactor core, the flow is continuously developing along the heated length as the vapor flowrate increases and the flow regimes evolve from bubbly to annular flow. Indeed, the entire annular flow regime may exist only over tens of L/D's. Despite these limitations, many of the advanced reactor safety analysis codes employ the Wallis model for interfacial friction in annular flow. Our analyses of the conditions existing at the end-of-reflood in the PERICLES tests have indicated that the Wallis model seriously underestimates the interfacial shear for low vapor velocity cocurrent upflow. To extend the annular flow data base to diabatic low flowrate conditions, the DADINE tests were re-analyzed. In these tests, both pressure drop and local cross-section averaged void fractions were measured. Thus, both the wall and interfacial shear can be deduced. Based on the results of this analysis, a new correlation is proposed for interfacial friction in annular flow. (authors). 5 figs., 12 refs

  1. Fabrication and Resintering of Annular UO2 Pellet

    International Nuclear Information System (INIS)

    Nuclear fuel is one of the most important components in a PWR affecting its safety and economy. The traditional PWR fuel pellet has a shape of cylindrical tablets of about 800 μm in diameter with a chamfer and dishes. A significant reduction in its failure rate has resulted from the improvements in fuel and cladding quality. Enhanced fuel assembly design allowed appreciable power density increases. However, it is difficult to achieve a significant increase of a power density under the current fuel pin design. Recently, Massachusetts Institute of Technology (MIT) has proposed an annular UO2 fuel with an internal cooling of each fuel rod. Annular fuel pellets with a voided central region have been used in VVER reactors without an internal cooling. Annular fuels with both internal and external cooling have been proposed for high temperature gas cooled reactors. However, commercial PWR reactors have not used such annular internally and externally cooled fuel rods, yet. There must be a lot of considerations in the various fields to introduce an annular internally and externally cooled fuel to commercial PWR reactors. The dimension tolerance and the thermal stability of a pellet are very important from the viewpoint of fabrication technology, because they have an influence on the size of the gap between the pellet and the inner/outer claddings. In this study, annular UO2 pellets with various densities were fabricated and then a resintering test was conducted. The changes of dimension and density of the sintered pellets were characterized

  2. Sonographic evaluation of digital annular pulley tears

    International Nuclear Information System (INIS)

    Objective. To evaluate the sonographic (US) appearance of digital annular pulley (DAP) tears in high-level rock climbers. Design and patients. We performed a retrospective analysis of the US examinations of 16 high-level rock climbers with clinical signs of DAP lesions. MRI and surgical evaluation were performed in five and three patients respectively. The normal US and MRI appearances of DAP were evaluated in 40 and three normal fingers respectively. Results. Nine of 16 patients presented a DAP tear. In eight subjects (seven with complete tears involving the fourth finger and one the fifth finger), US diagnosis was based on the indirect sign of volar bowstringing of the flexor tendons. Injured pulleys were not appreciated by US. Tears concerned the A2 and A3 in six patients and the A3 and A4 in two patients. A2 pulley thickening and hypoechogenicity compatible with a partial tear was demonstrated in one patient. MRI and surgical data correlated well with the US findings. Four patients had tenosynovitis of the flexor tendons but no evidence of pulley disruption. US examinations of three patients were normal. In the healthy subjects US demonstrated DAP in 16 of 40 digits. Conclusion. US can diagnose DAP tears and correlates with the MRI and surgical data. Because of its low cost and non-invasiveness we suggest US as the first imaging modality in the evaluation of injuries of the digital pulley. (orig.)

  3. Annular burnout data from rod bundle experiments

    International Nuclear Information System (INIS)

    Burnout data for annular flow in a rod bundle are presented for both transient and steady-state conditions. Tests were performed at the Oak Ridge National Laboratory in the Thermal Hydraulic Test Facility (THTF), a pressurized-water loop containing an electrically heated 64-rod bundle. The bundle configuration is typical of later generation pressurized-water reactors with 17 x 17 fuel arrays. Both axial and radial power profiles are flat. All experiments were carried out in upflow with subcooled inlet conditions, insuring accurate flow measurement. Conditions within the bundle were typical of those which could be encountered during a nuclear reactor loss-of-coolant accident. Level average fluid conditions within the test section were calculated using steady-state mass and energy conservation considerations for the steady-state tests and a transient, homogeneous, equilibrium computer code for the transient tests. Unlike tube dryout, burnout within a rod bundle does not necessarily occur at one distinct axial level. The location of individual rod dryout was determined by scanning rods axially and locating the position where rod superheat increased from approx. =0 to 30 K or greater. Thermocouple instrumentation within the bundle allows the location of dryout to be determined to within approximately +.5 cm for many of the tests

  4. The numerical calculation of heat transfer performance for annular flow of liquid nitrogen in a vertical annular channel

    Science.gov (United States)

    Sun, Shufeng; Wu, Yuyuan; Zhao, Rongyi

    2001-04-01

    According to a separated phase flow model for vertical annular two-phase flow in an annular channel, the liquid film thickness, distributions of velocities and temperatures in the liquid layer are predicted in the range of heat fluxes: 6000-12000 W/m 2, mass flux: 500-1100 kg/m2 s. The pressure drop along the flow channel and heat transfer coefficient are also calculated. The liquid film thickness is in the order of micrometers and heat transfer coefficient is 2800-7800 W/m2 K of liquid nitrogen boiling in narrow annular channels. The measured heat transfer coefficient is 29% higher than the calculated values. With the mass flux increasing and the gap of the annular channel decreasing, pressure drop and heat transfer coefficient increase.

  5. Age dependency of central and peripheral systolic blood pressures: Cross-sectional and longitudinal observations in European populations

    OpenAIRE

    Wojciechowska, Wiktoria; Stolarz-Skrzypek, Katarzyna; Tikhonoff, Valérie; Richart, Tom; Seidlerová, Jitka; Cwynar, Marcin; Thijs, Lutgarde; Li, Yan; Kuznetsova, Tatiana; Filipovský, Jan; Casiglia, Edoardo; Grodzicki, Tomasz; Kawecka-Jaszcz, Kalina; O'Rourke, Michael; Staessen, Jan A.

    2012-01-01

    Abstract Background. As arteries become stiffer with ageing, reflected waves move faster and augment late systolic pressure. We investigated the age dependency of peripheral and central systolic pressure, pressure amplification (peripheral systolic blood pressure - central systolic blood pressure), and peripheral and central systolic augmentation (maximal systolic pressure minus the first peak of the pressure wave). Methods. We randomly recruited 1420 White Europeans (mean age, 41.7 years). p...

  6. X-ray diffraction from bone employing annular and semi-annular beams

    International Nuclear Information System (INIS)

    There is a compelling need for accurate, low cost diagnostics to identify osteo-tissues that are associated with a high risk of fracture within an individual. To satisfy this requirement the quantification of bone characteristics such as ‘bone quality’ need to exceed that provided currently by densitometry. Bone mineral chemistry and microstructure can be determined from coherent x-ray scatter signatures of bone specimens. Therefore, if these signatures can be measured, in vivo, to an appropriate accuracy it should be possible by extending terms within a fracture risk model to improve fracture risk prediction.In this preliminary study we present an examination of a new x-ray diffraction technique that employs hollow annular and semi-annular beams to measure aspects of ‘bone quality’. We present diffractograms obtained with our approach from ex vivo bone specimens at Mo Kα and W Kα energies. Primary data is parameterized to provide estimates of bone characteristics and to indicate the precision with which these can be determined. (paper)

  7. Atrial Fibrillation Ablation in Systolic Dysfunction: Clinical and Echocardiographic Outcomes

    Directory of Open Access Journals (Sweden)

    Tasso Julio Lobo

    2015-01-01

    Full Text Available Background: Heart failure and atrial fibrillation (AF often coexist in a deleterious cycle. Objective: To evaluate the clinical and echocardiographic outcomes of patients with ventricular systolic dysfunction and AF treated with radiofrequency (RF ablation. Methods: Patients with ventricular systolic dysfunction [ejection fraction (EF <50%] and AF refractory to drug therapy underwent stepwise RF ablation in the same session with pulmonary vein isolation, ablation of AF nests and of residual atrial tachycardia, named "background tachycardia". Clinical (NYHA functional class and echocardiographic (EF, left atrial diameter data were compared (McNemar test and t test before and after ablation. Results: 31 patients (6 women, 25 men, aged 37 to 77 years (mean, 59.8±10.6, underwent RF ablation. The etiology was mainly idiopathic (19 p, 61%. During a mean follow-up of 20.3±17 months, 24 patients (77% were in sinus rhythm, 11 (35% being on amiodarone. Eight patients (26% underwent more than one procedure (6 underwent 2 procedures, and 2 underwent 3 procedures. Significant NYHA functional class improvement was observed (pre-ablation: 2.23±0.56; postablation: 1.13±0.35; p<0.0001. The echocardiographic outcome also showed significant ventricular function improvement (EF pre: 44.68%±6.02%, post: 59%±13.2%, p=0.0005 and a significant left atrial diameter reduction (pre: 46.61±7.3 mm; post: 43.59±6.6 mm; p=0.026. No major complications occurred. Conclusion: Our findings suggest that AF ablation in patients with ventricular systolic dysfunction is a safe and highly effective procedure. Arrhythmia control has a great impact on ventricular function recovery and functional class improvement.

  8. Effect of left ventricular systolic function on left atrial filling

    International Nuclear Information System (INIS)

    The effect of left ventricular (LV) systolic function on left atrial (LA) filling was studied using radionuclide angiography (RNA) and echocardiography in 21 normal subjects and in 40 patients with various heart deseases who had no regurgitant or shunt flow. The LV and LA time-activity curves (TAC) and these first-derivative curves were derived from RNA. The peak rate of LA filling during the atrial filling phase was normalized to the LA maximum counts and was defined as the LA peak filling rate (LAf-PFR). In all patients and normal subjects, the LV peak ejection rate (LVs-PER) occurred at a time close to that of LAf-PFR ((132 ± 22 msec (mean ± SD) vs 139 ± 34 msec, NS)). With use of the following equations, the peak rates of the LV emptying or LA filling determined by the RNA were converted from counts/sec to ml/sec by equating the echocardiographically-derived LV end-diastolic volume or LA maximum volume to the LV end-diastolic counts or the LA maximum counts, respectively. LVs-max dV/dt (ml/sec) = (LVs-PER) x (LV end-diastolic volume). LAf-max dV/dt (ml/sec) = (LAf-PFR) x (LA maximum volume). There was a significant positive correlation between the LVs-max dV/dt, an index of LV systolic function, and the LAf-max dV/dt, an index of LA filling function (r = 0.58, p < 0.001) in all patients and normal subjects. This indicates that the LA peak filling rate increases progressively as the LV peak ejection rate. Thus, these results suggest that the LA filling might be affected by the LV systolic function. (author)

  9. Effect of left ventricular systolic function on left atrial filling

    International Nuclear Information System (INIS)

    The effect of left ventricular (LV) systolic function on left atrial (LA) filling was studied using radionuclide angiography (RNA) and echocardiography in 17 normal subjects and in 40 patients with various heart disease who had no regurgitant or shunt flow. The LV and LA time-activity curves (TAC) and these first-derivative curves were derived from RNA. The peak rate of LA filling during the atrial filling phase was normalized to the LA maximal counts and was defined as the LA peak filling rate (LAf-PFR). In all patients and normal subjects, the LV peak ejection rate (LVs-PER) occurred at a time close to that of LAf-PFR (131 ± 22 msec (mean ± SD) vs. 140 ± 35 msec, NS). With use of the following equations, the peak rates of the LV emptying or LA filling determined by the RNA were converted from counts/sec to ml/sec by equating the echocardiographically-derived LV end-diastolic volume or LA maximal volume to the LV end-diastolic counts or the LA maximal counts, respectively. LVs-max dV/dt (ml/sec) = LVs-PER x (LV end-diastolic volume). LAf-max dV/dt (ml/sec) = LAf-PFR x (LA maximal volume). There was a significant positive correlation between the LVs-max dV/dt, an index of LV systolic function, and the LAf-max dV/dt, an index of LA filling function (r = 0.57, p < 0.001) in all patients and normal subjects. This indicates that the LA peak filling rate increases progressively as the LV peak ejection rate. Thus, these results suggest that the LA filling might be affected by the LV systolic function. (author)

  10. Unified Parallel Systolic Multiplier Over GF(2m)

    Institute of Scientific and Technical Information of China (English)

    Chiou-Yng Lee; Yung-Hui Chen; Che-Wun Chiou; Jim-Min Lin

    2007-01-01

    In general, there are three popular basis representations, standard (canonical, polynomial) basis, normal basis,and dual basis, for representing elements in GF(2m).Various basis representations have their distinct advantages and have their different associated multiplication architectures.In this paper, we will present a unified systolic multiplication arhitec-ture, by employing Hankel matrix-vector multiplication, for various basis representations.For various element representation in GF(2m), we will show that various basis multiplications can be performed by Hankel matrix-vector multiplications.A comparison with existing and similar structures has shown that the proposed architectures perform well both in space and time complexities.

  11. Sea Carousel—A benthic, annular flume

    Science.gov (United States)

    Amos, Carl L.; Grant, J.; Daborn, G. R.; Black, K.

    1992-06-01

    A benthic annular flume (Sea Carousel) has been developed and tested to measure in situ the erodibility of cohesive sediments. The flume is equipped with three optical backscatter sensors, a lid rotation switch, and an electromagnetic (EM) flow meter capable of detecting azimuthal and vertical components of flow. Data are logged at rates up to 10·66 Hz. Erodibility is inferred from the rate of change in suspended sediment concentration detected in the annulus. The energy-density/wave number spectrum of azimuthal flow showed peaks in the energy spectrum at paddle rotation wave numbers (k) of 14 and 7 m -1 (macroturbulent time scales) but were not significant. Friction velocity ( U*), measured (1) at 1 Hz using a flush-mounted hot-film sensor, and (2) derived from measured velocity profiles in the inner part of the logarithmic layer gave comparable results for Ū* 0·32 m s -1. Radial velocity gradients were proportional to ( Ū y - 0·32 m s -1). Maximum radial differences in U* were 10% for Ū y = 0·5 ms -1. Suspended sediment mass concentration ( S) in the annulus resulted in a significant decrease (10·5%) in Ū* derived by method (1) over the range 0calibration with changes in S. Subaerial deployments of Sea Carousel caused severe substrate disturbance, water losses, and aeration of the annulus. Submarine deployments produced stable results, though dispersion of turbid flume water took place. Results clearly demonstrated the existence of 'Type I' and 'Type II' erosion documented from laboratory studies.

  12. Quantitative assessment of two dimensional strain echocardiography in long-axis regional systolic function of left ventricle in patients with diabetes mellitus

    International Nuclear Information System (INIS)

    Objective: To assess the long-axis regional systolic function of the left ventricle (LV) in patients with type 2 diabetes mellitus (T2DM) using two-dimensional strain echocardiography (2D-SE) and explore clinical application value of 2D-SE. Methods: 30 T2DM patients with normal LV ejection fraction (LVEF ≥ 55%), 30 normal controls were selected. The peak strain of segments in apical long-axis, four-chamber, and two-chamber views were evaluated, and average peak strain in the long axis at basal, middle and apical levels were assessed by automated functional imaging (AFI). Results: LVEDV, LVESV, SV and LVEF in T2DM patients and normal controls were all within normal limits. Furthermore, there was no significant difference between the two groups (P>0.05). Compared with normal controls, the peak strain at each plane in T2DM patients was significantly reduced (P<0.01). Conclusion: The long-axis regional systolic function of LV in the patients with T2DM is impaired ahead of global systolic function disturbance. 2D-SE may be used to identify early abnormalities of systolic function in T2DM patients with normal LVEF. (authors)

  13. 3D strain measurement in electronic devices using through-focal annular dark-field imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suhyun; Jung, Younheum; Lee, Sungho; Jung Kim, Joong; Byun, Gwangseon; Lee, Sunyoung; Lee, Haebum

    2014-11-15

    Spherical aberration correction in high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) allows us to form an electron probe with reduced depth of field. Using through-focal HAADF imaging, we experimentally demonstrated 3D strain measurement in a strained-channel transistor. The strain field distribution in the channel region was obtained by scanning an electron beam over a plan-view specimen. Furthermore, the decrease in the strain fields toward the silicon substrate was revealed at different focal planes with a 5-nm focal step. These results demonstrate that it is possible to reconstruct the 3D strain field in electronic devices. - Highlights: • Three dimensional strain fields were measured using through-focal HAADF-STEM series. • The technique was applied to the channel of a plan-view strained-silicon device. • The strain values agreed with the results obtained using cross-section specimen.

  14. Elliptic annular Josephson tunnel junctions in an external magnetic field: the statics

    DEFF Research Database (Denmark)

    Monaco, Roberto; Granata, Carmine; Vettoliere, Antonio;

    2015-01-01

    We have investigated the static properties of one-dimensional planar Josephson tunnel junctions (JTJs) in the most general case of elliptic annuli. We have analyzed the dependence of the critical current in the presence of an external magnetic field applied either in the junction plane or in the...... perpendicular direction. We report a detailed study of both short and long elliptic annular junctions having different eccentricities. For junctions having a normalized perimeter less than one the threshold curves are derived and computed even in the case with one trapped Josephson vortex. For longer junctions...... a numerical analysis is carried out after the derivation of the appropriate perturbed sine-Gordon equation. For a given applied field we find that a number of different phase profiles exist which differ according to the number of fluxon-antifluxon pairs. We demonstrate that in samples made by...

  15. Dynamic Response Control of Three-Layered Annular Plate Due to Various Parametres of Electrorheological Core

    Directory of Open Access Journals (Sweden)

    Pawlus Dorota

    2016-03-01

    Full Text Available The paper presents dynamic responses of annular plate composed of three layers. The middle layer of the plate has electrorheological properties expressed by the Bingham body model. The plate is loaded in the plane of facings with time-dependent forces. The electrorheological effect is observed in the area of supercritical plate behaviour. The influence of both material properties and geometrical dimensions of the core on plate behaviour is examined. The problem is solved analytically and numerically using the orthogonalization method and the finite difference method. Comparison of the results obtained using the finite difference and the finite element methods for a plate in critical state is shown. The numerical calculations are carried out for axisymmetric and asymmetric plate modes. The presented diagrams show the plate reaction to the changes in values of plate parameters and indicate that the supercritical control of plate work is possible.

  16. Left ventricular systolic and diastolic function in hyperthyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, M.J.; Okada, R.D.; Ewy, G.A.; Hellman, D.J.

    1982-12-01

    In order to assess the effect of hyperthyroidism on systolic and diastolic function of the left ventricle, M-mode echocardiograms and systolic time intervals were obtained in 13 patients while they were clinically hyperthyroid and again when they were euthyroid following radioactive iodine therapy. Echocardiographic tracings of the septum and left ventricular posterior wall were digitized and analyzed to provide the maximum velocity of shortening and maximum velocity of lengthening. These velocities were normalized for left ventricular diastolic dimension. The left ventricular minor axis fractional shortening and the normalized maximum velocity of shortening were both increased during the hyperthyroid state. The normalized maximum velocity of lengthening, a measure of diastolic left ventricular function, was also increased during the hyperthyroid state when compared to the euthyroid state. The preejection period index and the preejection period/left ventricular ejection time ratio were lower when the patients were hyperthyroid than when they were euthyroid. These data confirm the increased inotropic state and demonstrated increased diastolic relaxation velocities of the hyperthyroid left ventricle.

  17. Rotordynamic Analysis of Textured Annular Seals With Multiphase (Bubbly Flow

    Directory of Open Access Journals (Sweden)

    Gérard PINEAU

    2011-09-01

    Full Text Available For some applications it must be considered that the flow in the annular seal contains a mixture of liquid and gas. The multiphase character of the flow is described by the volume fraction of gas (usually air contained in the liquid under the form of bubbles.The fluid is then a homogenous mixture of air and liquid all thru the annular seal. Its local gas volume fraction depends on the pressure field and is calculated by using a simplified form of the Rayleigh-Plesset equation.The influence of such of a multiphase (bubbly flow on the dynamic characteristics of a straight annular seal is minimal because the volume of the fluid is reduced.The situation is quite different for textured annular (damper seals provided with equally spaced deep cavities intended to increase the damping capabilities and to reduce the leakage flow rate.As a by-product, the volume of the fluid in the seal increases drastically and the compressibility effects stemming from the bubbly nature of the flow are largely increased even for a low gas volume fraction. The present work depicts the influence of the gas volume fraction on the dynamic characteristics of a textured annular seal. It is shown that variations of the gas volume fraction between 1% and 0.1% can lead to frequency dependent stiffness, damping and added mass coefficients.

  18. Vibration Analysis of Annular Sector Plates under Different Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Dongyan Shi

    2014-01-01

    Full Text Available An analytical framework is developed for the vibration analysis of annular sector plates with general elastic restraints along each edge of plates. Regardless of boundary conditions, the displacement solution is invariably expressed as a new form of trigonometric expansion with accelerated convergence. The expansion coefficients are treated as the generalized coordinates and determined using the Rayleigh-Ritz technique. This work allows a capability of modeling annular sector plates under a variety of boundary conditions and changing the boundary conditions as easily as modifying the material properties or dimensions of the plates. Of equal importance, the proposed approach is universally applicable to annular sector plates of any inclusion angles up to 2π. The reliability and accuracy of the current method are adequately validated through numerical examples.

  19. Hydrodynamic stability of inverted annular flow in an adiabatic simulation

    International Nuclear Information System (INIS)

    In experiments, inverted annular flow was simulated adiabatically with turbulent water jets, issuing downward from long aspect nozzles, enclosed in gas annuli. Velocities, diameters, and gas species were varied, and core jet length, shape, break-up mode, and dispersed-core droplet sizes were recorded at approximately 750 data points. Inverted annular flow was observed to develop into inverted slug flow at low relative velocities, and into dispersed droplet flow at high relative velocities. For both of the above transitions from inverted annular flow, a correlation for core jet length was developed by extending work done on free liquid jets to include this new, coaxial, jet disintegration phenomenon. The result, showing length dependence upon diameter, jet Reynolds number, jet Weber number, void fraction, and gas Weber number, correlates the data well, especially at moderate-to-large relative velocities

  20. Fluidic Analysis in an Annular Centrifugal Contactor for Fuel Reprocessing

    International Nuclear Information System (INIS)

    An annular centrifugal contactor (ACC) is a promising device for fuel reprocessing process, because it offers several advantages—a smaller size, a smaller holdup volume, and a higher separation performance—over conventional contactors such as a mixer-settler and a pulse column. Fluid dynamics and dispersion in an ACC, which has a combined mixer/centrifuge structure, are closely related to its separation performance and capacity, and this information is useful in improving equipment design. In this paper, experimental and computational fluid dynamics (CFD) studies were conducted to analyze fluidic and dispersion behavior in ACCs. Multiphase mixing (water/TBP-dodecane/air) in the annular zone was observed by Particle Imaging Velocimetry, and the change in the fluidic and dispersion behavior was ascertained under several operational conditions. The results of the CFD studies, which considered multiphase turbulent flow in the annular and rotor interior zones, were in a good agreement with the experimental data. (author)

  1. Air entrainment into annular water flows in a vertical pipe

    International Nuclear Information System (INIS)

    An experimental investigation was carried out on air entrainment into water flowing downward in a vertical pipe. Local flow rates of water and air in a fluid layer of annular flow, formed on the pipe wall, were measured precisely by using a small tube probe. Measurements were also made of local flow rates of water and air in bubbly flow downstream of annular water flow. Distributions of local flow rates in the radial direction of the pipe for annular flow regime indicate that the fluid layer consists of a water layer adjacent to the pipe wall and a water-air (two-phase fluid) layer located inside of the water layer. The water-air layer is formed as a result of air entrainment. The departure of air bubbles from a water pool to air phase was found for bubbly flow regime. (author)

  2. On rank 4 projective planes

    OpenAIRE

    Bachmann, O.

    1981-01-01

    Let a finite projective plane be called rank m plane if it admits a collineation group G of rank m, let it be called strong rank m plane if moreover GP=G1 for some point-line pair (P,1). It is well known that every rank 2 plane is desarguesian (Theorem of Ostrom and Wagner). It is conjectured that the only rank 3 plane is the plane of order 2. By [1] and [7] the only strong rank 3 plane is the plane of order 2. In this paper it is proved that no strong rank 4 plane exists.

  3. Annular elastolytic giant cell granuloma in association with Hashimoto's thyroiditis

    Directory of Open Access Journals (Sweden)

    Rishi Hassan

    2016-01-01

    Full Text Available Annular elastolytic giant cell granuloma (AEGCG is a rare granulomatous skin disease characterized clinically by annular plaques with elevated borders and atrophic centers found mainly on sun-exposed skin and histologically by diffuse granulomatous infiltrates composed of multinucleated giant cells, histiocytes and lymphocytes in the dermis along with phagocytosis of elastic fibers by multinucleated giant cells. We report a case of AEGCG in a 50-year-old woman and is highlighted for the classical clinical and histological findings of the disease and its rare co-existence with Hashimoto's thyroiditis.

  4. Annular elastolytic giant cell granuloma in association with Hashimoto's thyroiditis.

    Science.gov (United States)

    Hassan, Rishi; Arunprasath, P; Padmavathy, L; Srivenkateswaran, K

    2016-01-01

    Annular elastolytic giant cell granuloma (AEGCG) is a rare granulomatous skin disease characterized clinically by annular plaques with elevated borders and atrophic centers found mainly on sun-exposed skin and histologically by diffuse granulomatous infiltrates composed of multinucleated giant cells, histiocytes and lymphocytes in the dermis along with phagocytosis of elastic fibers by multinucleated giant cells. We report a case of AEGCG in a 50-year-old woman and is highlighted for the classical clinical and histological findings of the disease and its rare co-existence with Hashimoto's thyroiditis. PMID:27057492

  5. Portal annular pancreas: the pancreatic duct ring sign on MRCP.

    Science.gov (United States)

    Lath, Chinar O; Agrawal, Dilpesh S; Timins, Michael E; Wein, Melissa M

    2015-12-01

    Portal annular pancreas is a rare pancreatic variant in which the uncinate process of the pancreas extends and fuses to the dorsal surface of the body of the pancreas by surrounding the portal vein. It is asymptomatic, but it can be mistaken for a pancreatic head mass on imaging and could also have serious consequences during pancreatic surgery, if unrecognized. We report this case of a 53-year-old female patient who was diagnosed to have portal annular pancreas on the basis of an unusual course (ring appearance) of the main pancreatic duct on magnetic resonance cholangiopancreatography, not described earlier in the radiology literature. PMID:26649117

  6. Portal annular pancreas: the pancreatic duct ring sign on MRCP

    Directory of Open Access Journals (Sweden)

    Chinar O. Lath, MD

    2015-12-01

    Full Text Available Portal annular pancreas is a rare pancreatic variant in which the uncinate process of the pancreas extends and fuses to the dorsal surface of the body of the pancreas by surrounding the portal vein. It is asymptomatic, but it can be mistaken for a pancreatic head mass on imaging and could also have serious consequences during pancreatic surgery, if unrecognized. We report this case of a 53-year-old female patient who was diagnosed to have portal annular pancreas on the basis of an unusual course (ring appearance of the main pancreatic duct on magnetic resonance cholangiopancreatography, not described earlier in the radiology literature.

  7. Flow Visualisation of Annular Liquid Sheet Instability & Atomisation

    CERN Document Server

    Duke, Daniel; Soria, Julio

    2012-01-01

    Fluid dynamics videos of unstable thin annular liquid sheets are presented in this short paper. These videos are to be presented in the Gallery of Fluid Motion for the American Physical Society 65th Annual Meeting of the Division of Fluid Dynamics in San Diego, CA, 18-20 November 2012. An annular sheet of thickness h=1mm and mean radius R=18.9mm is subjected to aerodynamic axial shear from co-flowing air at various shear rates on both the inner and outer surface at a liquid sheet Reynolds Number of Re=500.

  8. Detrended fluctuation analysis of a systolic blood pressure control loop

    Energy Technology Data Exchange (ETDEWEB)

    Galhardo, C E C; Penna, T J P; Argollo de Menezes, M [Instituto de Fisica, Universidade Federal Fluminense, Av. Litoranea, s/n, 24210-340, Niteroi, RJ (Brazil); Soares, P P S [Instituto Biomedico, Universidade Federal Fluminense, R. Prof. Hernani Melo n. 101, 24210-130, Niteroi, RJ (Brazil)], E-mail: marcio@mail.if.uff.br

    2009-10-15

    We use detrended fluctuation analysis (DFA) to study the dynamics of blood pressure oscillations and its feedback control in rats by analyzing systolic pressure time series before and after a surgical procedure that interrupts its control loop. We found, for each situation, a crossover between two scaling regions characterized by exponents that reflect the nature of the feedback control and its range of operation. In addition, we found evidence of adaptation in the dynamics of blood pressure regulation a few days after surgical disruption of its main feedback circuit. Based on the paradigm of antagonistic, bipartite (vagal and sympathetic) action of the central nerve system, we propose a simple model for pressure homeostasis as the balance between two nonlinear opposing forces, successfully reproducing the crossover observed in the DFA of actual pressure signals.

  9. Assessment of right ventricular systolic function by tissue Doppler echocardiography

    DEFF Research Database (Denmark)

    Kjærgaard, Jesper

    2012-01-01

    pulmonary hypertension and exercise in normal individuals. Phosphodiestares-5 inhibition by sildenafil may predominantly be effective during hypoxia in resting conditions, and may improve the blunted response in RV contractility seen with exercise in hypoxia [VII]. Reduced RV free wall deformation can be...... promising tool for improving our understanding of right ventricular hemodynamics, several aspects of the technology must be evaluated. The accuracy and reproducibility of the technology is evaluated in vitro, and normal values, impact of changes in loading of the right ventricle, response to exercise and...... not add to the information gained from other quantitative echocardiographic measures of LV and RV function and pressure [VI]. Changes in tissue Doppler based measures of RV systolic function can be used to monitor the effect of selective vasodilation by phosphodiestares-5 inhibition in hypoxic...

  10. Detrended Fluctuation Analysis of Systolic Blood Pressure Control Loop

    CERN Document Server

    Galhardo, C E C; de Menezes, M Argollo; Soares, P P S

    2009-01-01

    We use detrended fluctuation analysis (DFA) to study the dynamics of blood pressure oscillations and its feedback control in rats by analyzing systolic pressure time series before and after a surgical procedure that interrupts its control loop. We found, for each situation, a crossover between two scaling regions characterized by exponents that reflect the nature of the feedback control and its range of operation. In addition, we found evidences of adaptation in the dynamics of blood pressure regulation a few days after surgical disruption of its main feedback circuit. Based on the paradigm of antagonistic, bipartite (vagal and sympathetic) action of the central nerve system, we propose a simple model for pressure homeostasis as the balance between two nonlinear opposing forces, successfully reproducing the crossover observed in the DFA of actual pressure signals.

  11. Design of Linear Systolic Arrays for Matrix Multiplication

    Directory of Open Access Journals (Sweden)

    MILOVANOVIC, E. I.

    2014-02-01

    Full Text Available This paper presents architecture for matrix multiplication optimized to be integrated as an accelerator unit to a host computer. Two linear systolic arrays with unidirectional data flow (ULSA, used as hardware accelerators, where synthesized in this paper. The solution proposed here is designed to accelerate both the computation and communication by employing hardware address generator units (AGUs. The proposed design has been implemented on Xilinx Spartan-2E and Virtex4 FPGAs. In order to evaluate performance of the proposed solution, we have introduced quantitative and qualitative performance criteria. For the ULSA with n processing elements (PEs, the speed-up is O(n/2. Average gain factor of hardware AGUs is about 2.7, with hardware overhead of 0.6% for 32-bit PEs.

  12. A comparison between brachial and echocardiographic systolic time intervals.

    Directory of Open Access Journals (Sweden)

    Ho-Ming Su

    Full Text Available Systolic time interval (STI is an established noninvasive technique for the assessment of cardiac function. Brachial STIs can be automatically determined by an ankle-brachial index (ABI-form device. The aims of this study are to evaluate whether the STIs measured from ABI-form device can represent those measured from echocardiography and to compare the diagnostic values of brachial and echocardiographic STIs in the prediction of left ventricular ejection fraction (LVEF <50%. A total of 849 patients were included in the study. Brachial pre-ejection period (bPEP and brachial ejection time (bET were measured using an ABI-form device and pre-ejection period (PEP and ejection time (ET were measured from echocardiography. Agreement was assessed by correlation coefficient and Bland-Altman plot. Brachial STIs had a significant correlation with echocardiographic STIs (r = 0.644, P<0.001 for bPEP and PEP; r  = 0.850, P<0.001 for bET and ET; r = 0.708, P<0.001 for bPEP/bET and PEP/ET. The disagreement between brachial and echocardiographic STIs (brachial STIs minus echocardiographic STIs was 28.55 ms for bPEP and PEP, -4.15 ms for bET and ET and -0.11 for bPEP/bET and PEP/ET. The areas under the curve for bPEP/bET and PEP/ET in the prediction of LVEF <50% were 0.771 and 0.765, respectively. Brachial STIs were good alternatives to STIs obtained from echocardiography and also helpful in prediction of LVEF <50%. Brachial STIs automatically obtained from an ABI-form device may be helpful for evaluation of left ventricular systolic dysfunction.

  13. Fluid-Structure Interaction Analysis on Turbulent Annular Seals of Centrifugal Pumps during Transient Process

    OpenAIRE

    Dazhuan Wu; Leqin Wang; Qinglei Jiang; Lulu Zhai

    2011-01-01

    The current paper studies the influence of annular seal flow on the transient response of centrifugal pump rotors during the start-up period. A single rotor system and three states of annular seal flow were modeled. These models were solved using numerical integration and finite difference methods. A fluid-structure interaction method was developed. In each time step one of the three annular seal models was chosen to simulate the annular seal flow according to the state of rotor systems. The ...

  14. Left atrial systolic force in hypertensive patients with left ventricular hypertrophy: the LIFE study

    DEFF Research Database (Denmark)

    Chinali, M.; Simone, G. de; Wachtell, K.;

    2008-01-01

    patients (52.3%), who were older and had higher body mass index and heart rate (all P < 0.01) but similar systolic and diastolic blood pressure, in comparison with patients with normal left atrial systolic force. After controlling for confounders, increased left atrial systolic force was associated with......In hypertensive patients without prevalent cardiovascular disease, enhanced left atrial systolic force is associated with left ventricular hypertrophy and increased preload. It also predicts cardiovascular events in a population with high prevalence of obesity. Relations between left atrial...

  15. Thermal Hydraulic Analysis Of Thorium-Based Annular Fuel Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Han, Kyu Hyun [Korea Institute of Nuclear Safety, 19, Guseong-dong, Yuseong-gu, Daejeon, 305-338 (Korea, Republic of)

    2008-07-01

    Thermal hydraulic characteristics of thorium-based fuel assemblies loaded with annular seed pins have been analyzed using AMAP combined with MATRA, and compared with those of the existing thorium-based assemblies. MATRA and AMAP showed good agreements for the pressure drops at the internal sub-channels. The pressure drop generally increased in the cases of the assemblies loaded with annular seed pins due to the larger wetted perimeter, but an exception existed. In the inner sub-channels of the seed pins, mass fluxes were high due to the grid form losses in the outer sub-channels. About 43% of the heat generated from the seed pin flowed into the inner sub-channel and the rest into the outer sub-channel, which implies the inner to outer wall heat flux ratio was approximately 1.2. The maximum temperatures of the annular seed pins were slightly above 500 deg. C. The MDNBRs of the assemblies loaded with annular seed pins were higher than those of the existing assemblies. Due to the fact that inter-channel mixing cannot occur in the inner sub-channels, temperatures and enthalpies were higher in the inner sub-channels. (author)

  16. Thermal Hydraulic Analysis Of Thorium-Based Annular Fuel Assemblies

    International Nuclear Information System (INIS)

    Thermal hydraulic characteristics of thorium-based fuel assemblies loaded with annular seed pins have been analyzed using AMAP combined with MATRA, and compared with those of the existing thorium-based assemblies. MATRA and AMAP showed good agreements for the pressure drops at the internal sub-channels. The pressure drop generally increased in the cases of the assemblies loaded with annular seed pins due to the larger wetted perimeter, but an exception existed. In the inner sub-channels of the seed pins, mass fluxes were high due to the grid form losses in the outer sub-channels. About 43% of the heat generated from the seed pin flowed into the inner sub-channel and the rest into the outer sub-channel, which implies the inner to outer wall heat flux ratio was approximately 1.2. The maximum temperatures of the annular seed pins were slightly above 500 deg. C. The MDNBRs of the assemblies loaded with annular seed pins were higher than those of the existing assemblies. Due to the fact that inter-channel mixing cannot occur in the inner sub-channels, temperatures and enthalpies were higher in the inner sub-channels. (author)

  17. Annular linear induction pump with an externally supported duct

    International Nuclear Information System (INIS)

    Several embodiments of an annular linear induction pump for pumping liquid metals are disclosed having the features of generally one pass flow of the liquid metal through the pump and an increased efficiency resulting from the use of thin duct walls to enclose the stator. The stator components of this pump are removable for repair and replacement. 15 claims

  18. Localized granuloma annulare and autoimmune thyroid disease. Are they associated?

    OpenAIRE

    Moran, J; Lamb, J.

    1995-01-01

    This case report identifies a temporal relationship between the diagnosis of localized granuloma annulare and the subsequent development of primary hypothyroidism in a previously healthy 10-year-old girl. We suspect these disorders are associated, but any association between them requires further study.

  19. Improvement of image processing algorithms for annular flow

    International Nuclear Information System (INIS)

    Annular flow occurs in a wide range of industrial heat-transfer equipment, including the top of a BWR core, in the steam generator of a PWR, and in postulated accident scenarios including critical heat flux (CHF) by dryout. The modeling of annular flow often requires information regarding the average thickness of liquid film at the periphery of the flow channel as a measurement of film roughness (film roughness concept). More recently, two-region modeling efforts require wave intermittency as a measurement of disturbance wave (as opposed to base film thickness) contribution to gas-to-liquid momentum transfer and pressure loss. The present work focuses on the characterization of film behaviors in annular flow using quantitative visualization. The data reduction codes for planar laser-induced flourescence (PLIF) imaging and back-lit quartz tube imaging have been further developed to improve measurement accuracy. Film thickness distribution (base film and wave), disturbance wave length, and wave intermittency estimates have been updated and applied to a recent two-region annular flow model. Outputs of average film thickness, pressure gradient, and average wave velocity have been modeled with mean absolute errors of 8.70%, 17.42%, and 19.14%, respectively. (author)

  20. Study of film boiling dispersed two phase in narrow annular gap

    International Nuclear Information System (INIS)

    Experimental investigation on film boiling dispersed two phase friction pressure drop in narrow annular gap with deionized water was performed in three types of narrow annular gap. The friction pressure drop differences were compared between narrow annular gap and circular channel was compared in the paper. The influence of narrow annular gap on friction pressure drop was examined in this paper. Results showed that the modified Sadatomi's correlation can be used to calculate film boiling dispersed two-phase friction pressure drop in narrow annular gap for engineering application

  1. Systolic Compression of Epicardial Coronary and Intramural Arteries: in Children with Hypertrophic Cardiomyopathy

    OpenAIRE

    Mohiddin, Saidi A; Fananapazir, Lameh

    2002-01-01

    It has been suggested that systolic compression of epicardial coronary arteries is an important cause of myocardial ischemia and sudden death in children with hypertrophic cardiomyopathy. We examined the associations between sudden death, systolic coronary compression of intra- and epicardial arteries, myocardial perfusion abnormalities, and severity of hypertrophy in children with hypertrophic cardiomyopathy.

  2. Oscillometric measurement of systolic and diastolic blood pressures validated in a physiologic mathematical model

    Directory of Open Access Journals (Sweden)

    Babbs Charles F

    2012-08-01

    Full Text Available Abstract Background The oscillometric method of measuring blood pressure with an automated cuff yields valid estimates of mean pressure but questionable estimates of systolic and diastolic pressures. Existing algorithms are sensitive to differences in pulse pressure and artery stiffness. Some are closely guarded trade secrets. Accurate extraction of systolic and diastolic pressures from the envelope of cuff pressure oscillations remains an open problem in biomedical engineering. Methods A new analysis of relevant anatomy, physiology and physics reveals the mechanisms underlying the production of cuff pressure oscillations as well as a way to extract systolic and diastolic pressures from the envelope of oscillations in any individual subject. Stiffness characteristics of the compressed artery segment can be extracted from the envelope shape to create an individualized mathematical model. The model is tested with a matrix of possible systolic and diastolic pressure values, and the minimum least squares difference between observed and predicted envelope functions indicates the best fit choices of systolic and diastolic pressure within the test matrix. Results The model reproduces realistic cuff pressure oscillations. The regression procedure extracts systolic and diastolic pressures accurately in the face of varying pulse pressure and arterial stiffness. The root mean squared error in extracted systolic and diastolic pressures over a range of challenging test scenarios is 0.3 mmHg. Conclusions A new algorithm based on physics and physiology allows accurate extraction of systolic and diastolic pressures from cuff pressure oscillations in a way that can be validated, criticized, and updated in the public domain.

  3. Prognostic significance of cardiovascular biomarkers and renal dysfunction in outpatients with systolic heart failure

    DEFF Research Database (Denmark)

    Bosselmann, Helle; Egstrup, Michael; Rossing, Kasper;

    2013-01-01

    To assess whether the prognostic significance of cardiovascular (CV) biomarkers, is affected by renal dysfunction (RD) in systolic heart failure (HF).......To assess whether the prognostic significance of cardiovascular (CV) biomarkers, is affected by renal dysfunction (RD) in systolic heart failure (HF)....

  4. Detection of systolic ejection click using time growing neural network.

    Science.gov (United States)

    Gharehbaghi, Arash; Dutoit, Thierry; Ask, Per; Sörnmo, Leif

    2014-04-01

    In this paper, we present a novel neural network for classification of short-duration heart sounds: the time growing neural network (TGNN). The input to the network is the spectral power in adjacent frequency bands as computed in time windows of growing length. Children with heart systolic ejection click (SEC) and normal children are the two groups subjected to analysis. The performance of the TGNN is compared to that of a time delay neural network (TDNN) and a multi-layer perceptron (MLP), using training and test datasets of similar sizes with a total of 614 normal and abnormal cardiac cycles. From the test dataset, the classification rate/sensitivity is found to be 97.0%/98.1% for the TGNN, 85.1%/76.4% for the TDNN, and 92.7%/85.7% for the MLP. The results show that the TGNN performs better than do TDNN and MLP when frequency band power is used as classifier input. The performance of TGNN is also found to exhibit better immunity to noise. PMID:24613501

  5. Systolic arterial pressure determination by a new pulse monitor technique.

    Science.gov (United States)

    Wong, D T; Volgyesi, G A; Bissonnette, B

    1992-07-01

    The Doppler ultrasound (DUS) technique is a widely accepted non-invasive technique to estimate systolic blood pressure (SBP) accurately in paediatric patients. The DUS has a number of limitations. A new pulse monitor, Mr Pulse (MP), operating on the principle of a finger plethysmograph, was developed to offer an alternative technique to estimate SBP. From 104 paired SBP measurements taken in 16 paediatric patients undergoing general anaesthesia, SBP determined by the MP technique correlated closely with that by the standard DUS technique (r2 = 0.98). Analysis of degree of agreement performed indicated that there was good agreement between SBP obtained by the MP and the DUS techniques. The mean +/- standard deviation of differences in paired SBP values between the two measurement techniques was 0.55 +/- 3.59 mmHg. Mr Pulse is as accurate as the DUS technique in estimating SBP and has the advantage of less critical sensor positioning as it is not subject to electrical interference. It has no electrical hazard. PMID:1643685

  6. In vivo adaptive response of the peripheral conduit artery in patients with borderline systolic hypertension

    Institute of Scientific and Technical Information of China (English)

    陶军; 靳亚非; 王礼春; 唐安丽; 廖新学; 杨震; 马虹

    2003-01-01

    Objective To investigate elastic changes of the radial artery, a medium-sized muscular peripheral conduit artery, in patients with borderline systolic hypertension. Methods Using a non-invasive high-resolution echo-tracking device coupled to a photoplethysmography (Finapres system) allowing simultaneous arterial diameter and finger blood pressure monitoring, we measured radial artery elastic parameters of 20 patients with borderline systolic hypertension and 20 normal subjects according to Langewouters model.Results The diameter of the radial artery of control subjects and those with borderline systolic hypertension at the isobaric level of 100 mmHg and mean arterial pressure was similar, but the compliance and distensibility at similar conditions in patients with borderline systolic hypertension did not further reduced and even increased. Conclusion In patients with borderline systolic hypertension, the adaptive responses of the radial artery compliance and distensibility to increased pressure were directed to maintain its elasticity, contributing to the homeostasis of the cardiovascular system.

  7. Physiological Responses Associated with Nordic-Walking Training in Systolic Hypertensive Postmenopausal Women

    Directory of Open Access Journals (Sweden)

    Latosik Ewelina

    2014-12-01

    Full Text Available Loss of physical strength and hypertension are among the most pronounced detrimental factors accompanying aging. The aim of this study was to evaluate the influence of a supervised 8-week Nordic-walking training program on systolic blood pressure in systolic-hypertensive postmenopausal women. This study was a randomized control trial on a sample of 24 subjects who did not take any hypertension medications. There was a statistically significant decrease in systolic blood pressure and an increase in lower and upper-body strength in the group following Nordic-walking training. There was a decrease in serum levels of total cholesterol, triglycerides, and low-density cholesterol. The obtained results indicate that an 8-week Nordic-walking program may be efficiently employed for counteracting systolic hypertension through a direct abatement of systolic blood pressure and an increase of maximal aerobic capacity.

  8. BKP plane partitions

    Energy Technology Data Exchange (ETDEWEB)

    Foda, Omar; Wheeler, Michael [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)

    2007-01-15

    Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another.

  9. BKP plane partitions

    OpenAIRE

    Foda, O.; Wheeler, M.

    2006-01-01

    Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another.

  10. BKP plane partitions

    International Nuclear Information System (INIS)

    Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another

  11. Homogeneous Plane Waves

    OpenAIRE

    Blau, Matthias; O'Loughlin, Martin

    2002-01-01

    Motivated by the search for potentially exactly solvable time-dependent string backgrounds, we determine all homogeneous plane wave (HPW) metrics in any dimension and find one family of HPWs with geodesically complete metrics and another with metrics containing null singularities. The former generalises both the Cahen-Wallach (constant $A_{ij}$) metrics to time-dependent HPWs, $A_{ij}(t)$, and the Ozsvath-Sch\\"ucking anti-Mach metric to arbitrary dimensions. The latter is a generalisation of ...

  12. Boundaries in digital planes

    Directory of Open Access Journals (Sweden)

    Efim Khalimsky

    1990-01-01

    Full Text Available The importance of topological connectedness properties in processing digital pictures is well known. A natural way to begin a theory for this is to give a definition of connectedness for subsets of a digital plane which allows one to prove a Jordan curve theorem. The generally accepted approach to this has been a non-topological Jordan curve theorem which requires two different definitions, 4-connectedness, and 8-connectedness, one for the curve and the other for its complement.

  13. Assessment of right ventricular systolic function by tissue Doppler echocardiography.

    Science.gov (United States)

    Kjærgaard, Jesper

    2012-03-01

    -massive pulmonary embolism quantifies degree of RV dysfunction, and supports the existence of the McConnell sign of mid-ventricular RV dysfunction. Echocardiographic signs of RV dysfunction are present if > 25% of the pulmonary vascular bed is obstructed. However, Tissue Doppler echocardiography and deformation analysis has no independent value over other clinical and quantitative echocardiographic measures of RV size, pressure and function in these patients [IV and V]. Regional deformation of the RV free wall has significant prognostic importance in a population suspected of first non-massive pulmonary embolism, and is significantly associated with adverse events in patients with proven pulmonary embolism, however, it does not add to the information gained from other quantitative echocardiographic measures of LV and RV function and pressure [VI]. Changes in tissue Doppler based measures of RV systolic function can be used to monitor the effect of selective vasodilation by phosphodiestares-5 inhibition in hypoxic pulmonary hypertension and exercise in normal individuals. Phosphodiestares-5 inhibition by sildenafil may predominantly be effective during hypoxia in resting conditions, and may improve the blunted response in RV contractility seen with exercise in hypoxia [VII]. Reduced RV free wall deformation can be quantified by tissue Doppler echocardiography in patients with confirmed Arrhythmogenic Right Ventricular Cardiomyopathy, but the clinical application of the technique may be limited by considerable overlap with normal values [VIII]. Acute RV volume loading in free pulmonary regurgitation is associated with abrupt geometric changes in the RV structure including significant dilatation, but is well tolerated with only mild reduction in measures of global RV systolic function as estimated by 2D echocardiography in an experimental animal model. Regional RV myocardial function is also only mildly reduced. Also no differences in global or regional RV function can be observed

  14. Severe systolic hypertension and the search for safer motherhood.

    Science.gov (United States)

    Martin, James N

    2016-03-01

    Timely and appropriate response to severe hypertension during gestation is an important component of quality, safe care for pregnant or puerperal mothers regardless of causation. The reduction of severe maternal morbidity and maternal mortality in the hypertensive mother is clearly enhanced by the addition of standard protocols for provider response to severe hypertension, particularly severe systolic hypertension. The program developed in New York State via the Safe Motherhood Initiative promotes the implementation of unit-specific safety bundles, especially one that is focused upon a standardized approach to handling the obstetric emergency of severe hypertension usually associated with preeclampsia/eclampsia. The comprehensive preeclampsia/eclampsia safety bundle as summarized by Drs. Moroz and colleagues is reviewed especially from the perspective of its focus on the timely and specific responses for health care providers to make when severe hypertension is detected in the pregnant patient. Evidence-based guidance to practice considerations and clinical care of patients with preeclampsia/eclampsia is embedded within the program outlined for New York State by Moroz and her District II ACOG colleagues. There is a central focus on timely and appropriate antepartum/postpartum management of severe hypertension, a core concept to lessen maternal risk for cerebral hemorrhage. Ten considerations for further integration into the New York program are suggested. Beyond blood pressure control, there is a need for systematic review of interventions and outcomes over time, attention to possible future variations of the protocol for racial/ethnic patient groups at highest risk for maternal morbidity and mortality, and the identification of biomarker(s) that further specify and quantify risk to the maternal brain and other organ systems when severe hypertension develops. Safer motherhood will happen when evidence for best practice is integrated into systems of care for all

  15. ANNULAR PANCREAS CAUSING DUODENAL OBSTRUCTION: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Swish Kumar

    2016-01-01

    Full Text Available Annular pancreas is a rare congenital anomaly characterized by the band of pancreatic tissue of variable width partially or completely encircling the duodenum. This abnormality, although at times clinically silent or may be the cause of a broad spectrum of diseases. Complications range from neonatal intestinal obstruction to more complex pathologies in the adult such as pancreatitis, duodenal stenosis or duodenal or gastric ulceration. This condition is important to recognise, because radiologists are usually the first person to diagnose such condition. We report the case of a young patient of 10 years old female hospitalized for epigastric pain and repeated episodes of vomiting, in whom radiological investigations showed an annular pancreas. No other congenital anomaly of the intra-abdominal organs was noted. Both the rarity of this congenital abnormality and its probability of successful correction by surgical means have prompted us to make the following presentation.

  16. Analysis of a Low-Angle Annular Expander Nozzle

    Directory of Open Access Journals (Sweden)

    Kyll Schomberg

    2015-01-01

    Full Text Available An experimental and numerical analysis of a low-angle annular expander nozzle is presented to observe the variance in shock structure within the flow field. A RANS-based axisymmetric numerical model was used to evaluate flow characteristics and the model validated using experimental pressure readings and schlieren images. Results were compared with an equivalent converging-diverging nozzle to determine the capability of the wake region in varying the effective area of a low-angle design. Comparison of schlieren images confirmed that shock closure occurred in the expander nozzle, prohibiting the wake region from affecting the area ratio. The findings show that a low angle of deflection is inherently unable to influence the effective area of an annular supersonic nozzle design.

  17. Energy and Exergy Analysis of an Annular Thermoelectric Heat Pump

    Science.gov (United States)

    Kaushik, S. C.; Manikandan, S.; Hans, Ranjana

    2016-07-01

    In this paper, the concept of an annular thermoelectric heat pump (ATEHP) has been introduced. An exoreversible thermodynamic model of the ATEHP considering the Thomson effect in conjunction with Peltier, Joule and Fourier heat conduction has been investigated using exergy analysis. New expressions for dimensionless heating power, optimum current at the maximum energy, exergy efficiency conditions and dimensionless irreversibilities in the ATEHP are derived. The results show that the heating power, energy and exergy efficiency of the ATEHP are lower than the flat-plate thermoelectric heat pump. The effects of annular shape parameter ( S r = r 2 /r 1), dimensionless temperature ratio ( θ = T h /T c) and the electrical contact resistances on the heating power, energy/exergy efficiency of an ATEHP have been studied. This study will help in the designing of actual ATEHP systems.

  18. High Thrust-to-Power Annular Engine Technology

    Science.gov (United States)

    Patterson, Michael J.; Thomas, Robert E.; Crofton, Mark W.; Young, Jason A.; Foster, John E.

    2015-01-01

    Gridded ion engines have the highest efficiency and total impulse of any mature electric propulsion technology, and have been successfully implemented for primary propulsion in both geocentric and heliocentric environments with excellent ground/in-space correlation of performance. However, they have not been optimized to maximize thrust-to-power, an important parameter for Earth orbit transfer applications. This publication discusses technology development work intended to maximize this parameter. These activities include investigating the capabilities of a non-conventional design approach, the annular engine, which has the potential of exceeding the thrust-to-power of other EP technologies. This publication discusses the status of this work, including the fabrication and initial tests of a large-area annular engine. This work is being conducted in collaboration among NASA Glenn Research Center, The Aerospace Corporation, and the University of Michigan.

  19. Axisymmetric buckling of laminated thick annular spherical cap

    Science.gov (United States)

    Dumir, P. C.; Dube, G. P.; Mallick, A.

    2005-03-01

    Axisymmetric buckling analysis is presented for moderately thick laminated shallow annular spherical cap under transverse load. Buckling under central ring load and uniformly distributed transverse load, applied statically or as a step function load is considered. The central circular opening is either free or plugged by a rigid central mass or reinforced by a rigid ring. Annular spherical caps have been analysed for clamped and simple supports with movable and immovable inplane edge conditions. The governing equations of the Marguerre-type, first order shear deformation shallow shell theory (FSDT), formulated in terms of transverse deflection w, the rotation ψ of the normal to the midsurface and the stress function Φ, are solved by the orthogonal point collocation method. Typical numerical results for static and dynamic buckling loads for FSDT are compared with the classical lamination theory and the dependence of the effect of the shear deformation on the thickness parameter for various boundary conditions is investigated.

  20. Energy and Exergy Analysis of an Annular Thermoelectric Heat Pump

    Science.gov (United States)

    Kaushik, S. C.; Manikandan, S.; Hans, Ranjana

    2016-04-01

    In this paper, the concept of an annular thermoelectric heat pump (ATEHP) has been introduced. An exoreversible thermodynamic model of the ATEHP considering the Thomson effect in conjunction with Peltier, Joule and Fourier heat conduction has been investigated using exergy analysis. New expressions for dimensionless heating power, optimum current at the maximum energy, exergy efficiency conditions and dimensionless irreversibilities in the ATEHP are derived. The results show that the heating power, energy and exergy efficiency of the ATEHP are lower than the flat-plate thermoelectric heat pump. The effects of annular shape parameter (S r = r 2 /r 1), dimensionless temperature ratio (θ = T h /T c) and the electrical contact resistances on the heating power, energy/exergy efficiency of an ATEHP have been studied. This study will help in the designing of actual ATEHP systems.

  1. Development of annular targets for 99Mo production

    International Nuclear Information System (INIS)

    During 1999, significant progress was made in the development of a low-enriched uranium (LEU) target for production of 99Mo. Successful conversion requires an inexpensive, reliable target. To keep the target geometry the same when changing from high-enriched uranium (HEU) to LEU targets, a denser form of uranium is required in order to increase the amount of uranium per target by a factor of approximately five. Targets containing LEU in the form of a metal foil are being developed for producing 99Mo from the fissioning of 235U. A new annular target was developed this year, and seven targets were irradiated in the Indonesian RSG-GAS reactor. Results of development of this annular target and its performance during irradiation are described. (author)

  2. Production of annular flat-topped vortex beams

    Institute of Scientific and Technical Information of China (English)

    Jiannong Chen; Yongjiang Yu; Feifei Wang

    2011-01-01

    @@ A model of an annular flat-topped vortex beam based on multi-Gaussian superimposition is proposed. We experimentally produce this beam with a computer-generated hologram (CGH) displayed on a spatial light modulator (SLM). The power of the beam is concentrated on a single-ring structure and has an extremely strong radial intensity gradient. This beam facilitates various applications ranging from Sisyphus atom cooling to micro-particle trapping.%A model of an annular fiat-topped vortex beam based on multi-Gaussian superimposition is proposed. We experimentally produce this beam with a computer-generated hologram (CGH) displayed on a spatial light modulator (SLM). The power of the beam is concentrated on a single-ring structure and has an extremely strong radial intensity gradient. This beam facilitates various applications ranging from Sisyphus atom cooling to micro-particle trapping.

  3. Electroosmotic flow and Joule heating in preparative continuous annular electrochromatography.

    Science.gov (United States)

    Laskowski, René; Bart, Hans-Jörg

    2015-09-01

    An openFOAM "computational fluid dynamic" simulation model was developed for the description of local interaction of hydrodynamics and Joule heating in annular electrochromatography. A local decline of electrical conductivity of the background eluent is caused by an electrokinetic migration of ions resulting in higher Joule heat generation. The model equations consider the Navier-Stokes equation for incompressible fluids, the energy equation for stationary temperature fields, and the mass transfer equation for the electrokinetic flow. The simulations were embedded in commercial ANSYS Fluent software and in open-source environment openFOAM. The annular gap (1 mm width) contained an inorganic C8 reverse-phase monolith as stationary phase prepared by an in situ sol-gel process. The process temperature generated by Joule heating was determined by thermal camera system. The local hydrodynamics in the prototype was detected by a gravimetric contact-free measurement method and experimental and simulated values matched quite well. PMID:25997390

  4. Excitational metamorphosis of surface flowfield under an impinging annular jet

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav; Trávníček, Zdeněk

    2008-01-01

    Roč. 144, č. 2 (2008), s. 312-316. ISSN 1385-8947 R&D Projects: GA ČR GA101/07/1499; GA AV ČR IAA200760705 Institutional research plan: CEZ:AV0Z20760514 Keywords : jets * impinging jets * flow topology * annular jets * stagnation points Subject RIV: BK - Fluid Dynamics Impact factor: 2.813, year: 2008 http://www.sciencedirect.com/

  5. Heat transfer to liquid sodium flowing through annular channel, (4)

    International Nuclear Information System (INIS)

    An experimental study was carried out to clarify the heat transfer characteristics of liquid sodium flowing turbulently through an annular channel. For a concentric condition, average psi(=average epsilonH/epsilonM) was found to agree with that proposed by Aoki or Ramm for circular tube. For eccentric conditions, circumferential temperature variations around the inner wall were measured and Nusselt numbers were evaluated. Numerical calculations were also made for temperature fields and compared with the measurements. (author)

  6. Unusual Presentation of Acute Annular Urticaria: A Case Report

    OpenAIRE

    Gilles Guerrier; Jean-Marc Daronat; Roger Deltour

    2011-01-01

    Acute urticarial lesions may display central clearing with ecchymotic or haemorrhagic hue, often misdiagnosed as erythema multiforme, serum-sickness-like reactions, or urticarial vasculitis. We report a case of acute annular urticaria with unusual presentation occurring in a 20-month-old child to emphasize the distinctive morphologic manifestations in a single disease. Clinicians who care for children should be able to differentiate acute urticaria from its clinical mimics. A directed history...

  7. Ignition sequence of an annular multi-injector combustor

    OpenAIRE

    Philip, Maxime; Boileau, Matthieu; Vicquelin, Ronan; Schmitt, Thomas; Durox, Daniel; Bourgoin, Jean-François; Candel, Sébastien

    2013-01-01

    Ignition is a critical process in combustion systems. In aeronautical combustors, altitude relight capacities are required in case of accidental extinction of the chamber. A simultaneous study of light-round ignition in an annular multi-injector combustor has been performed on the experimental and numerical sides. This effort allows a unique comparison to assess the reliability of Large-Eddy Simulation (LES) in such a configuration. Results are presented in fluid dynamics videos.

  8. Large Eddy Simulation of thermoacoustic instabilities in annular combustion chambers

    OpenAIRE

    Wolf, Pierre

    2011-01-01

    Increasingly stringent regulations and the need to tackle rising fuel prices have placed great emphasis on the design of aeronautical gas turbines. This drive towards innovation has resulted sometimes in new concepts being prone to combustion instabilities. Combustion instabilities arise from the coupling of acoustics and combustion. In the particular field of annular combustion chambers, these instabilities often take the form of azimuthal modes. To predict these modes, one must consider the...

  9. Thermohydraulic analysis of smooth and finned annular ducts

    International Nuclear Information System (INIS)

    The present work is concerned with the turbulent heat transfer and pressure drop in smooth and finned annular ducts overage heat transfer coefficients have been obtained by means of the heat exchanger theory. In addition, friction factors have also been determined. The experiments were performed by utilizing four double-pipe heat exchangers. The flowing fluids, in the heat exchangers, were air and water. The average heat transfer coefficients, for air flowing in the annular section, were determined by measuring the overall heat transfer coefficients of the heat exchangers. In order to attain fully developed conditions, the heat exchangers had a starting length of 30 hydraulic diameters. The thermal boundary conditions consisted of uniform temperature on the inner surface, the outer surface being insulated. The heat transfer coefficients and friction factors are presented in dimensionaless forms, as functions of the Reynolds number of the flow. The results for the smooth and finned annular ducts were compared. The purpose of such comparison was to study the influence of the fins on the pressure drop and heat transfer rate. In the case of the finned nular ducts, it is shown that the fin efficiency has some fluence on the heat transfer rates. The, a two-dimensional at transfer analysis was performed in order to obtain the n efficiency and the annular region efficiency. It is also shown that the overall thermal performance of finned surfaces epends mainly on the Nusselt number and on the region eficiency. These parameters are presented as functions of the Reynolds number of the flow and the geometry of the problem. (author)

  10. Hydraulic forces caused by annular pressure seals in centrifugal pumps

    Science.gov (United States)

    Iino, T.; Kaneko, H.

    1980-01-01

    The hydraulic forces caused by annular pressure seals were investigated. The measured inlet and exit loss coefficients of the flow through the seals were much smaller than the conventional values. The results indicate that the damping coefficient and the inertia coefficient of the fluid film in the seal are not affected much by the rotational speed or the eccentricity of the rotor, though the stiffness coefficient seemed to be influenced by the eccentricity.

  11. Active Control of Fan Noise: Feasibility Study. Volume 6; Theoretical Analysis for Coupling of Active Noise Control Actuator Ring Sources to an Annular Duct with Flow

    Science.gov (United States)

    Kraft, R. E.

    1996-01-01

    The objective of this effort is to develop an analytical model for the coupling of active noise control (ANC) piston-type actuators that are mounted flush to the inner and outer walls of an annular duct to the modes in the duct generated by the actuator motion. The analysis will be used to couple the ANC actuators to the modal analysis propagation computer program for the annular duct, to predict the effects of active suppression of fan-generated engine noise sources. This combined program will then be available to assist in the design or evaluation of ANC systems in fan engine annular exhaust ducts. An analysis has been developed to predict the modes generated in an annular duct due to the coupling of flush-mounted ring actuators on the inner and outer walls of the duct. The analysis has been combined with a previous analysis for the coupling of modes to a cylindrical duct in a FORTRAN computer program to perform the computations. The method includes the effects of uniform mean flow in the duct. The program can be used for design or evaluation purposes for active noise control hardware for turbofan engines. Predictions for some sample cases modeled after the geometry of the NASA Lewis ANC Fan indicate very efficient coupling in both the inlet and exhaust ducts for the m = 6 spinning mode at frequencies where only a single radial mode is cut-on. Radial mode content in higher order cut-off modes at the source plane and the required actuator displacement amplitude to achieve 110 dB SPL levels in the desired mode were predicted. Equivalent cases with and without flow were examined for the cylindrical and annular geometry, and little difference was found for a duct flow Mach number of 0.1. The actuator ring coupling program will be adapted as a subroutine to the cylindrical duct modal analysis and the exhaust duct modal analysis. This will allow the fan source to be defined in terms of characteristic modes at the fan source plane and predict the propagation to the

  12. Entrainment in vertical annular two-phase flow

    International Nuclear Information System (INIS)

    Prediction of amount of entrained droplets or entrainment fraction in annular two-phase flow is essential for the estimation of dryout condition and analysis of post dryout heat transfer in light water nuclear reactors and steam boilers. In this study, air-water and organic fluid (Freon-113) annular flow entrainment experiments have been carried out in 9.4 and 10.2 mm diameter test sections, respectively. Both the experiments covered three distinct pressure conditions and wide range of liquid and gas flow conditions. The organic fluid experiments simulated high pressure steam-water annular flow conditions. In each of the experiments, measurements of entrainment fraction, droplet entrainment rate and droplet deposition rate have been performed by using a liquid film extraction method. A simple, explicit and non-dimensional correlation developed by Sawant et al. (2008a) for the prediction of entrainment fraction is further improved in this study in order to account for the existence of critical gas and liquid flow rates below which no entrainment is possible. Additionally, a new correlation is proposed for the estimation of minimum liquid film flow rate at the maximum entrainment fraction condition. The improved correlation successfully predicted the newly collected air-water and Freon-113 entrainment fraction data. Furthermore, the correlations satisfactorily compared with the air-water, helium-water and air-genklene experimental data measured by Willetts (1987). (author)

  13. Treatment of generalized granuloma annulare - a systematic review.

    Science.gov (United States)

    Lukács, J; Schliemann, S; Elsner, P

    2015-08-01

    Granuloma annulare (GA) is a benign inflammatory skin disease. Localized GA is likely to resolve spontaneously, while generalized GA (GGA) is rare and may persist for decades. GGA usually is resistant to a variety of therapeutic modalities and takes a chronic course. The objective of this study was to summarize all reported treatments of generalized granuloma annulare. This is a systematic review based on MEDLINE, Embase and Cochrane Central Register search of articles in English and German and a manual search, between 1980 and 2013, to summarize the treatment of generalized granuloma annulare. Most medical literature on treatment of GGA is limited to individual case reports and small series of patients treated without a control group. Randomized controlled clinical studies are missing. Multiple treatment modalities for GGA were reported including topical and systemic steroids, PUVA, isotretinoin, dapsone, pentoxifylline, hydroxychloroquine, cyclosporine, IFN-γ, potassium iodide, nicotinamide, niacinamide, salicylic acid, dipyridamole, PDT, fumaric acid ester, etanercept, infliximab, adalimumab. While there are numerous case reports of successful treatments in the literature including surgical, medical and phototherapy options, well-designed, randomized, controlled clinical trials are required for an evidence-based treatment of GGA. PMID:25651003

  14. Experimental study on particles mixing in an annular spouted bed

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Huang; Guoxin, Hu [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China); Fengchao, Wang [Science and Technology Development Office, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2008-02-15

    A novel annular spouted bed was developed and studied experimentally. The experiments were performed to examine the effects of feeding mode, air velocity and static bed height as well as particle size on particle mixing for different conditions in this device. The results show that feeding by a rotating cone greatly improves particle mixing by homogeneously projecting the particles into the annular bed. For feeding by a rotating cone, the time required to get uniform mixing laterally is shorten almost 10 times less than that for feeding at a fixed point. With increasing air velocity, the axial mixing speed increases more significantly than the lateral mixing speed. The static bed height has important effects on the uniformity of the final admixtures. With increasing static bed height, the degree of mixing of the final mixture (FDM) axially first decreases, then increases, but laterally, the FDM is monotone decreasing. The particles of small size are helpful to raise the mixing speed. In addition, the dead zone in the annular spouted bed was analyzed. (author)

  15. Experimental study on particles mixing in an annular spouted bed

    Energy Technology Data Exchange (ETDEWEB)

    Huang Hao [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China); Hu Guoxin [School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China)], E-mail: hugx@sjtu.edu.cn; Wang Fengchao [Science and Technology Development Office, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2008-02-15

    A novel annular spouted bed was developed and studied experimentally. The experiments were performed to examine the effects of feeding mode, air velocity and static bed height as well as particle size on particle mixing for different conditions in this device. The results show that feeding by a rotating cone greatly improves particle mixing by homogeneously projecting the particles into the annular bed. For feeding by a rotating cone, the time required to get uniform mixing laterally is shorten almost 10 times less than that for feeding at a fixed point. With increasing air velocity, the axial mixing speed increases more significantly than the lateral mixing speed. The static bed height has important effects on the uniformity of the final admixtures. With increasing static bed height, the degree of mixing of the final mixture (FDM) axially first decreases, then increases, but laterally, the FDM is monotone decreasing. The particles of small size are helpful to raise the mixing speed. In addition, the dead zone in the annular spouted bed was analyzed.

  16. Droplet sizes, dynamics and deposition in vertical annular flow

    International Nuclear Information System (INIS)

    The role of droplets in vertical upwards annular flow is investigated, focusing on the droplet size distributions, dynamics, and deposition phenomena. An experimental program was performed based on a new laser optical technique developed in these laboratories and implemented here for annular flow. This permitted the simultaneous measurement of droplet size, axial and radial velocity. The dependence of droplet size distributions on flow conditions is analyzed. The Upper-Log Normal function proves to be a good model for the size distribution. The mechanism controlling the maximum stable drop size was found to result from the interaction of the pressure fluctuations of the turbulent flow of the gas core with the droplet. The average axial droplet velocity showed a weak dependence on gas rates. This can be explained once the droplet size distribution and droplet size-velocity relationship are analyzed simultaneously. The surprising result from the droplet conditional analysis is that larger droplet travel faster than smaller ones. This dependence cannot be explained if the drag curves used do not take into account the high levels of turbulence present in the gas core in annular flow. If these are considered, then interesting new situations of multiplicity and stability of droplet terminal velocities are encountered. Also, the observed size-velocity relationship can be explained. A droplet deposition is formulated based on the particle inertia control. This permitted the calculation of rates of drop deposition directly from the droplet size and velocities data

  17. The influence of annular seal clearance to the critical speed of the multistage pump

    International Nuclear Information System (INIS)

    In the multistage pump of high head, pressure difference in two ends of annular seal clearance and rotor eccentric would produce the sealing fluid force, the effect of which can be expressed by a damping and stiffness coefficient. It has a great influence on the critical speed of the rotor system. In order to research the influence of the annular seal to the rotor system, this paper used CFD method to conduct the numerical simulation for the flow field of annular seal clearance. The radial and tangential forces were obtained to calculate the annular dynamic coefficients. Also dynamic coefficient were obtained by Matlab. The rotor system was modeled using ANSYS finite software and the critical speed with and without annular seal clearance were calculated. The result shows: annular seal's fluid field is under the comprehensive effect of pressure difference and rotor entrainment. Due to the huge pressure difference in front annular seal, fluid flows under pressure difference; the low pressure difference results in the more obvious effect on the clearance field in back annular seal. The first order critical speed increases greatly with the annular seal clearance; while the average growth rate of the second order critical speed is only 3.2%; the third and fourth critical speed decreases little. Based on the above result, the annular seal has great influence to the first order speed, while has little influence on the rest

  18. Plane and geodetic surveying

    CERN Document Server

    Johnson, Aylmer

    2004-01-01

    Plane and Geodetic Surveying blends theory and practice, conventional techniques and GPS, to provide the ideal book for students of surveying.Detailed guidance is given on how and when the principle surveying instruments (theodolites, Total Stations, levels and GPS) should be used. Concepts and formulae needed to convert instrument readings into useful results are explained. Rigorous explanations of the theoretical aspects of surveying are given, while at the same time a wealth of useful advice about conducting a survey in practice is provided. An accompanying least squares adjustment program

  19. Homogeneous plane waves

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Matthias E-mail: mblau@ictp.trieste.it; O' Loughlin, Martin E-mail: loughlin@sissa.it

    2003-03-24

    Motivated by the search for potentially exactly solvable time-dependent string backgrounds, we determine all homogeneous plane wave (HPW) metrics in any dimension and find one family of HPWs with geodesically complete metrics and another with metrics containing null singularities. The former generalises both the Cahen-Wallach (constant A{sub ij}) metrics to time-dependent HPWs, A{sub ij}(x{sup +}), and the Ozsvath-Schuecking anti-Mach metric to arbitrary dimensions. The latter is a generalisation of the known homogeneous metrics with A{sub ij}{approx}1/(x{sup +}){sup 2} to a more complicated time-dependence. We display these metrics in various coordinate systems, show how to embed them into string theory, and determine the isometry algebra of a general HPW and the associated conserved charges. We review the Lewis-Riesenfeld theory of invariants of time-dependent harmonic oscillators and show how it can be deduced from the geometry of plane waves. We advocate the use of the invariant associated with the extra (timelike) isometry of HPWs for lightcone quantisation, and illustrate the procedure in some examples.

  20. The MOND Fundamental Plane

    CERN Document Server

    Cardone, V F; Diaferio, A; Tortora, C; Molinaro, R

    2010-01-01

    Modified Newtonian Dynamics (MOND) has been shown to be able to fit spiral galaxy rotation curves as well as giving a theoretical foundation for empirically determined scaling relations, such as the Tully - Fisher law, without the need for a dark matter halo. As a complementary analysis, one should investigate whether MOND can also reproduce the dynamics of early - type galaxies (ETGs) without dark matter. As a first step, we here show that MOND can indeed fit the observed central velocity dispersion $\\sigma_0$ of a large sample of ETGs assuming a simple MOND interpolating functions and constant anisotropy. We also show that, under some assumptions on the luminosity dependence of the Sersic n parameter and the stellar M/L ratio, MOND predicts a fundamental plane for ETGs : a log - linear relation among the effective radius $R_{eff}$, $\\sigma_0$ and the mean effective intensity $\\langle I_e \\rangle$. However, we predict a tilt between the observed and the MOND fundamental planes.

  1. Homogeneous plane waves

    International Nuclear Information System (INIS)

    Motivated by the search for potentially exactly solvable time-dependent string backgrounds, we determine all homogeneous plane wave (HPW) metrics in any dimension and find one family of HPWs with geodesically complete metrics and another with metrics containing null singularities. The former generalises both the Cahen-Wallach (constant Aij) metrics to time-dependent HPWs, Aij(x+), and the Ozsvath-Schuecking anti-Mach metric to arbitrary dimensions. The latter is a generalisation of the known homogeneous metrics with Aij∼1/(x+)2 to a more complicated time-dependence. We display these metrics in various coordinate systems, show how to embed them into string theory, and determine the isometry algebra of a general HPW and the associated conserved charges. We review the Lewis-Riesenfeld theory of invariants of time-dependent harmonic oscillators and show how it can be deduced from the geometry of plane waves. We advocate the use of the invariant associated with the extra (timelike) isometry of HPWs for lightcone quantisation, and illustrate the procedure in some examples

  2. Homogeneous Plane Waves

    CERN Document Server

    Blau, Matthias; Blau, Matthias; Loughlin, Martin O'

    2003-01-01

    Motivated by the search for potentially exactly solvable time-dependent string backgrounds, we determine all homogeneous plane wave (HPW) metrics in any dimension and find one family of HPWs with geodesically complete metrics and another with metrics with null singularities. The former generalises both the Cahen-Wallach (constant $A_{ij}$) metrics to time-dependent HPWs, $A_{ij}(t)$, and the Ozsvath-Sch\\"ucking anti-Mach metric to arbitrary dimensions. The latter is a generalisation of the known homogeneous metrics with $A_{ij}\\sim 1/t^2$ to a more complicated time-dependence. We display these metrics in various coordinate systems, show how to embed them into string theory, and determine the isometry algebra of a general HPW and the associated conserved charges. We review the Lewis-Riesenfeld theory of invariants of time-dependent harmonic oscillators and show how it can be deduced from the geometry of plane waves. We advocate the use of the invariant associated with the extra (timelike) isometry of HPWs for ...

  3. Pancreaticoduodenectomy for pancreas carcinoma occurring in the annular pancreas: report of a case

    OpenAIRE

    Kawaida, Hiromichi; KONO, Hiroshi; Watanabe, Mitsuaki; Maki, Akira; Amemiya, Hidetake; Matsuda, Masanori; Fujii, Hideki; Fukasawa, Mitsuharu; Takahashi, Ei; Sano, Katsuhiro; Inoue, Tomohiro

    2015-01-01

    The annular pancreas is a rare congenital anomaly in which a ring of the pancreas parenchyma surrounds the second part of the duodenum. Malignant tumors are extremely rare in patients with an annular pancreas. A 64-year-old man presented with appetite loss and vomiting. Abdominal contrast-enhanced computed tomography (CT) indicated pancreas parenchyma surrounding the second part of the duodenum, and a hypovascular area occupying lesion in the annular pancreas. Subtotal stomach-preserving panc...

  4. Repeated mitral valve replacement in a patient with extensive annular calcification

    OpenAIRE

    Kitamura Tadashi; Fukuda Sachito; Sawada Takahiro; Miura Sumio; Kigawa Ikutaro; Miyairi Takeshi

    2011-01-01

    Abstract Background Mitral valve replacement in the presence of severe annular calcification is a technical challenge. Case report A 47-year-old lady who had undergone mitral and aortic valve replacement for rheumatic disease 27 years before presented with dyspnea. At reoperation, extensive mitral annular calcification was hindering the disc motion of the Starr-Edwards mitral prosthesis. The old prosthesis was removed and a St Jude Medical mechanical valve was implanted after thorough annular...

  5. Natriuretic peptide vs. clinical information for diagnosis of left ventricular systolic dysfunction in primary care

    OpenAIRE

    Wachter Rolf; Pouwels Claudia; Kleta Sibylle; Wetzel Dirk; Kochen Michael M; Lüers Claus; Scherer Martin; Koschack Janka; Herrmann-Lingen Christoph; Pieske Burkert; Binder Lutz

    2008-01-01

    Abstract Background Screening of primary care patients at risk for left ventricular systolic dysfunction by a simple blood-test might reduce referral rates for echocardiography. Whether or not natriuretic peptide testing is a useful and cost-effective diagnostic instrument in primary care settings, however, is still a matter of debate. Methods N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, clinical information, and echocardiographic data of left ventricular systolic function wer...

  6. Systolic Peak Detection in Acceleration Photoplethysmograms Measured from Emergency Responders in Tropical Conditions

    OpenAIRE

    Elgendi, Mohamed; Norton, Ian; Brearley, Matt; Abbott, Derek; Schuurmans, Dale

    2013-01-01

    Photoplethysmogram (PPG) monitoring is not only essential for critically ill patients in hospitals or at home, but also for those undergoing exercise testing. However, processing PPG signals measured after exercise is challenging, especially if the environment is hot and humid. In this paper, we propose a novel algorithm that can detect systolic peaks under challenging conditions, as in the case of emergency responders in tropical conditions. Accurate systolic-peak detection is an important f...

  7. The relationship of blood lead to systolic blood pressure in a longitudinal study of policemen.

    OpenAIRE

    Weiss, S T; Munoz, A.; Stein, A.; Sparrow, D.; Speizer, F E

    1988-01-01

    We examined the relationship of blood lead level to systolic and diastolic blood pressure in a longitudinal study of 89 Boston, MA, policemen. At the second examination blood lead level and blood pressure were measured in triplicate. Blood pressure measurements were taken in a similar fashion in years 3, 4, and 5. Multivariate analysis using a first-order autoregressive model revealed that after adjusting for previous systolic blood pressure, body mass index, age, and cigarette smoking, an el...

  8. Prognostic value of alveolar volume in systolic heart failure: a prospective observational study

    OpenAIRE

    Miniati, Massimo; Monti, Simonetta; Bottai, Matteo; Pavlickova, Ivana; Passino, Claudio; Emdin, Michele; Poletti, Roberta

    2013-01-01

    Background Ventilatory impairment is known to occur in patients with heart failure (HF). Alveolar volume (VA) is measured by the dilution of an inert gas during a single breath-hold maneuver. Such measurement is sensitive to ventilatory disturbances. We conducted a prospective, observational study to establish the prognostic value of VA in systolic HF. Methods We studied 260 consecutive patients who were hospitalized for systolic HF. All patients were evaluated under stable clinical condition...

  9. A simple versatile method for measuring tail cuff systolic blood pressure in conscious rats.

    Science.gov (United States)

    Widdop, R E; Li, X C

    1997-09-01

    1. The non-invasive measurement of tail cuff systolic blood pressure in conscious rats is routinely used in long-term cardiovascular studies. There are a number of commercially available tail cuff systems, however, these apparatus are generally expensive and are dedicated for single-task operations. In the present study, a simple method for measuring systolic blood pressure, which requires only minor modifications to the existing hardware found in most cardiovascular laboratories, is described. 2. Systolic blood pressure measurements were made in the conventional manner by determining the systolic blood pressure which coincided with the restoration of the caudal artery pulse. This was achieved by using an inexpensive piezo-electric pulse transducer to detect the pulse, and this was coupled to a standard data-acquisition system (MacLab, ADInstruments) normally set up to record blood pressure. This method was compared with another established tail cuff method, as well as with direct intra-arterial recordings. 3. It was found that the results obtained using both tail cuff systems were in good agreement when systolic blood pressure was measured in Wistar-Kyoto rats and spontaneously hypertensive rats. In addition, systolic blood pressure was measured over 4 weeks in 2K1C rats and sham-operated rats, with both tail cuff methods producing similar results, which were not significantly different from direct intra-arterial recordings in the same animals. 4. Thus, in the present study, with only minor modifications, the same equipment was used for both direct and indirect determinations of systolic blood pressure. This situation differs from other conventional tail cuff systems since these items are designed for a single purpose. Therefore, the current method using piezo-electric sensor/MacLab-technology should be viewed as a relatively simple, flexible and cheap alternative method to measure tail cuff systolic blood pressure in conscious rats. PMID:9337632

  10. Evaluation of Sleep Problems and Its Associated Factors in Male Patients with Systolic Heart Failure

    OpenAIRE

    Zeighami Mohammadi Sh.; Shahparian M.

    2013-01-01

    Background and Objectives: Sleep problems negatively impact on quality of life . In this study, sleep quality, sleep disorders, daytime sleepiness and their associated factors were evaluated in systolic heart failure patients.Methods: This cross-sectional study was conducted on 100 male patients with systolic heart failure. Simple sampling method was used for data collection. Data were collected using Epworth sleepiness scale questionnaire, sleep disorder index, and the Pittsburgh sleep quali...

  11. DIASTOLIC BLOOD PRESSURE OR ACTUALLY IT IS BASELINE SYSTOLIC BLOOD PRESSURE?

    Directory of Open Access Journals (Sweden)

    R.Vinodh Rajkumar

    2015-08-01

    Full Text Available Blood pressure measuring represents a routine investigation in general medicine. Nokolai Korotkoff was only 31 years old when he made a short presentation to the Scientific Meeting of the Military Hospital of the Academy on 5 November 1905 concerning an easy non-invasive method of blood pressure (BP measurement, entitled ‘Concerning the problems of the methods of blood pressure measurement’. If the pressure in the cuff is relieved, blood starts coming through the compressed arterial segment during systole and causes auscultatory sound and, the first sound, which, in Korotkoff’s opinion, is a measurement of systolic blood pressure. In the same BP measurement, when normal blood flow is fully restored, the auscultatory sounds disappear and, the last sound, which, in Korotkoff's opinion is a measurement of diastolic blood pressure. Listening to Korotkoff sounds (K-sounds to determine systolic and diastolic blood pressure (BP has been the standard for noninvasive BP measurement in medical practices for nearly 100 years and it is the essential tool used for evaluation and assessment of patients with hypertension and risks of cardiovascular diseases (CVD by physicians and nurses despite limited understanding of the nature of K-sounds. This article focuses particularly on the cardiovascular biomechanics of the first and last auscultatory sound and suggests two new terminologies; Highest systolic blood pressure and Baseline systolic blood pressure to represent the systolic pressure and diastolic pressure, respectively. Experimenting blood pressures on the basis of these two new suggested terminologies may reveal various additional undiscovered aspects of normal BP and abnormal BP. KEY WORDS: Highest systolic blood pressure, Baseline systolic blood pressure, Korotkoff sounds

  12. Assessment of left ventricular systolic and diastolic function in subclinical hypothyroidism

    OpenAIRE

    Velkoska Nakova, Valentina; Krstevska, Branka; Kostovska Srbinovska, Elizabeta; Vaskova, Olivija

    2015-01-01

    Objective: Studies investigating systolic and diastolic left ventricle function in subclinical hypothyroidism (ScH) have shown controversial results. As myocardium is a target organ of thyroid hormone action, the aim of the study was to assess the left ventricular systolic and diastolic function in ScH. Methods: Fifty-four patients with newly diagnosed ScH and 30 euthyroid controls, patients of the University Clinic of the Endocrinology, Diabetes, and Metabolic Disorders Clinic...

  13. Correlation between systolic function and presence of myofibroblasts in doxorubicin-induced cardiomyopathy

    OpenAIRE

    Fábio Nelson Gava; Sheila Nogueira Saraiva da Silva; Fernando Azadinho Rosa; Edna Mireya Gómez Ortiz; Bruno Cristian Rodrigues; Márcio de Barros Bandarra; Rosemeri de Oliveira Vasconcelos; Aparecido Antonio Camacho

    2016-01-01

    ABSTRACT: Cardiotoxicity induced by doroxubicin generates systolic disfunction and myocardial remodeling with presence of myofibroblasts. These cells are thought to be attracted to the injured heart to avoid the development of congestive heart failure. The objective of this study was to evaluate the systolic dysfunction generated by doxorubicin through Doppler echocardiography, and its correlation with the presence of myofibroblasts in the myocardium. Twenty-five New Zealand White rabbits wer...

  14. Duality and noncommutative planes

    DEFF Research Database (Denmark)

    Jøndrup, Søren

    2015-01-01

    We study extensions of simple modules over an associative ring A   and we prove that for twosided ideals mm and nn with artinian factors the condition ExtA1(A/m,A/n)≠0 holds for the left A  -modules A/mA/m and A/nA/n if and only if it holds for the right modules A/nA/n and A/mA/m. The methods pro...... proving this are applied to show that noncommutative models of the plane, i.e. algebras of the form k〈x,y〉/(f)k〈x,y〉/(f), where f∈([x,y])f∈([x,y]) are noetherian only in case (f)=([x,y])...

  15. An Annular Gap Acceleration Model for γ-ray Emission of Pulsars

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    If the binding energy of the pulsar's surface is not so high (the case of a neutron star), both negative and positive charges will flow out freely from the surface of the star. An annular free flow model for γ-ray emission of pulsars is suggested. It is emphasized that:(1) Two kinds of acceleration regions (annular and core) need to be taken into account. The annular acceleration region is defined by the magnetic field lines that cross the null charge surface within the light cylinder. (2) If the potential drop in the annular region of a pulsar is high enough (normally the case for young pulsars), charges in both the annular and the core regions could be accelerated and produce primary gamma-rays. Secondary pairs are generated in both regions and stream outwards to power the broadband radiations. (3) The potential drop grows more rapidly in the annular region than in the core region. The annular acceleration process is a key process for producing the observed wide emission beams. (4)The advantages of both the polar cap and outer gap models are retained in this model. The geometric properties of the γ-ray emission from the annular flow are analogous to that presented in a previous work by Qiao et al., which match the observations well. (5) Since charges with different signs leave the pulsar through the annular and the core regions respectively, the current closure problem can be partially solved.

  16. Development of probabilistic design method for annular fuel. Development of BORNFREE-CEPTAR code

    International Nuclear Information System (INIS)

    The increase of linear power and burn-up during the reactor operation is considered as one of measures for the utility of fast reactor in future, and then the application of annular fuels is under consideration. In order to make a design for thus annular fuels, annular fuel design code 'CEPTAR' has been developed in Japan Atomic Energy Agency (JAEA). In addition, probabilistic fuel design code 'BORNFREE' has been also developed for the reasonable fuel design with safety and the quantitative evaluation of design margin. In this study, aiming at the development of probabilistic design method, we developed BORNFREE-CEPTAR code to develop the reasonable design method for annular fuels. As the results of probability evaluation of fuel melting at the transient at the initial power increase, by using the probabilistic annular fuel design code 'BORNFREE-CEPTAR', the melting probability for annular fuels was estimated to be approximately two figures lower than that for solid fuels, and the remarkable decrease of melting probability, which was caused by the fuel restructuring effect, was seen in the estimation results for solid fuels, on the other hand, the results for annular fuels indicated that this effect was comparably small. In addition, the permissive linear power for annular fuels tended to enhance from that for solid fuels with the increase of initial central-hole diameter under the similar fuel melting probability condition. This indicated the possibility of higher linear power operation for high-density annular fuels than low-density solid fuels. (author)

  17. Electron beam diagnostic system using computed tomography and an annular sensor

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, John W.; Teruya, Alan T.

    2015-08-11

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  18. Electron beam diagnostic system using computed tomography and an annular sensor

    Science.gov (United States)

    Elmer, John W.; Teruya, Alan T.

    2014-07-29

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  19. [Echocardiographic parameters and systolic times in arterial hypertension in the elderly].

    Science.gov (United States)

    Pentimone, F; Santoro, G; Giusti, C; Di Bello, V; Cini, G; Del Corso, L

    1989-09-01

    In 40 subjects, 15 mean age 70.7 +/- 5.6 with systolic-diastolic hypertension, 15 mean age 75.5 +/- 6.8 years with systolic hypertension and 10 mean age 73.6 +/- 5.1 normotensive control group we have analyzed with M-mode 2D echocardiography and echophonocardiography the following parameters: diastolic--EDD--and systolic diameter--SD--of left ventricle, diastolic thickness of septum--SSD--and posterior wall--SPPD--of left ventricle, left ventricular ejection fraction--EF--(Theicholtr. formula), radius posterior wall thickness--R/SPPD--, left ventricular mass--LVM--(Devereux' formula), and systolic time intervals (Q-A2, LVET, PEP and PEP/LVET). The differences between groups are: systolic-diastolic hypertensive patients have increased EDD, SPPD and LVM, reduction of EF and increased PEP/LVET ratio in comparison with B and C groups; systolic hypertension doesn't increase EDD; SSD and PEP/LVET increase, while the EF remains within normal limits. In the healthy aged subjects SSD, SPPD and LVM are normal. PMID:2608185

  20. Physical understanding of gas-liquid annular flow and its transition to dispersed droplets

    Science.gov (United States)

    Kumar, Parmod; Das, Arup Kumar; Mitra, Sushanta K.

    2016-07-01

    Transformation from annular to droplet flow is investigated for co-current, upward gas-liquid flow through a cylindrical tube using grid based volume of fluid framework. Three transitional routes, namely, orificing, rolling, and undercutting are observed for flow transformation at different range of relative velocities between the fluids. Physics behind these three exclusive phenomena is described using circulation patterns of gaseous phase in the vicinity of a liquid film which subsequently sheds drop leading towards transition. Orifice amplitude is found to grow exponentially towards the core whereas it propagates in axial direction in a parabolic path. Efforts have been made to fit the sinusoidal profile of wave structure with the numerical interface contour at early stages of orificing. Domination of gas inertia over liquid flow has been studied in detail at the later stages to understand the asymmetric shape of orifice, leading towards lamella formation and droplet generation. Away from comparative velocities, circulations in the dominant phase dislodge the drop by forming either a ligament (rolling) or a bag (undercut) like protrusion in liquid. Study of velocity patterns in the plane of droplet dislodge reveals the underlying physics behind the disintegration and its dynamics at the later stages. Using numerical phase distributions, rejoining of dislodged droplet with liquid film as post-rolling consequences has been also proposed. A flow pattern map showing the transitional boundaries based on the physical mechanism is constructed for air-water combination.

  1. Modeling of annular film dryout with Cobra-TF

    International Nuclear Information System (INIS)

    The COBRA-TF computer code uses a two-fluid, three-field and three-dimensional formulation to model a two-phase flow field in a specific geometry. The liquid phase is divided in a continuous liquid field and a separate dispersed field, which is used to describe the entrained liquid drops. For each space dimension, the code solves three momentum equations, three mass conservation equations and two energy conservation equations. Entrainment and depositions models are implemented into the code to model the mass transfer between the two liquid fields. In annular flow condition critical heat flux is caused by annular film dryout. Film dryout is a complex function of the film flow rate, the applied heat flux, and the entrainment from the liquid film to the continuous vapor region, and the deposition of entrained droplets back to the liquid film. Because of the three-field approach, COBRA-TF hydrodynamic equations are able to predict dry-out by solving directly the film dry-out as a hydrodynamic process rather than using an empirical dry-out correlation. The dry-out is driven by the hydraulic calculation and the prediction is the result of the combined effect of the entrainment, the deposition models and interfacial heat transfer. The paper discusses the annular film entrainment and deposition models used in the code as well as the logic, which is used to determine the dry-out phenomena as the film thickness decreases. The obtained results with COBRA-TF are compared with the test data from the Bennett Tube Dry-out Experiments. In general, the COBRA-TF prediction of the dry-out location is in good agreement with Bennett test data. In particular, results show that the predicted dry-out length tends to be longer than the measured value and in the post dry-out region the wall temperature, which is dependent on vapor superheat, tends to be underestimated by the code. (authors)

  2. Characteristic analysis of a double stator annular linear electromagnetic pump

    International Nuclear Information System (INIS)

    A annular linear induction electromagnetic pump (ALIP) is generally used to transport liquid sodium coolants for liquid metal reactors. In the present study, the theoretical induction of a developing equation has been carried out for a double stator version of the ALIP which is noticebly employed for the sodium circulation of a large flowrate. The computerzed P-Q relation, which is represented by the pump geometrical and electrical variables, has been applied to a double stator version of the ALMR EM pump. An induced equation was verified by the compared analysis with the known data on the P-Q characteristic according to the input currents

  3. A high efficiency annular dark field detector for STEM.

    Science.gov (United States)

    Kirkland, E J; Thomas, M G

    1996-01-01

    A new high efficiency annular dark field (ADF) detector for an HB501 STEM (Scanning Transmission Electron Microscope) has been constructed and tested. This detector uses a single crystal YAP scintillator and a solid quartz light pipe extending from the scintillator (inside the vacuum) to the photomultiplier tube (outside the vacuum). A factor of approximately 100 improvement in signal relative to the original detector has been obtained. This has substantially improved the signal to noise ratio in the recorded high resolution ADF-STEM images. PMID:22666919

  4. Unusual Presentation of Acute Annular Urticaria: A Case Report

    Directory of Open Access Journals (Sweden)

    Gilles Guerrier

    2011-01-01

    Full Text Available Acute urticarial lesions may display central clearing with ecchymotic or haemorrhagic hue, often misdiagnosed as erythema multiforme, serum-sickness-like reactions, or urticarial vasculitis. We report a case of acute annular urticaria with unusual presentation occurring in a 20-month-old child to emphasize the distinctive morphologic manifestations in a single disease. Clinicians who care for children should be able to differentiate acute urticaria from its clinical mimics. A directed history and physical examination can reliably orientate necessary diagnostic testing and allow for appropriate treatment.

  5. Analytic vortex dynamics in an annular Bose-Einstein condensate

    Science.gov (United States)

    Toikka, L. A.; Suominen, K.-A.

    2016-05-01

    We consider analytically the dynamics of an arbitrary number and configuration of vortices in an annular Bose-Einstein condensate obtaining expressions for the free energy and vortex precession rates to logarithmic accuracy. We also obtain lower bounds for the lifetime of a single vortex in the annulus. Our results enable a closed-form analytic treatment of vortex-vortex interactions in the annulus that is exact in the incompressible limit. The incompressible hydrodynamics that is developed here paves the way for more general analytical treatments of vortex dynamics in non-simply-connected geometries.

  6. New fluxon resonant mechanism in annular Josephson tunnel structures

    International Nuclear Information System (INIS)

    A novel dynamical state has been observed in the dynamics of a perturbed sine-Gordon system. This resonant state has been experimentally observed as a singularity in the dc current-voltage characteristic of an annular Josephson tunnel junction, excited in the presence of a magnetic field. In this respect it can be assimilated to self-resonances known as Fiske steps. Differently from these, however, we demonstrate, on the basis of numerical simulations, that its detailed dynamics involves rotating fluxon pairs, a mechanism associated, so far, to self-resonances known as zero-field steps. This occurs because the size of nonlinear excitations is comparable with that of the system

  7. Critical heat flux prediction for the annular core research reactor

    International Nuclear Information System (INIS)

    This paper reports on best estimate predictions of Critical Heat Flux Ratio (CHFR) obtained to support the upgrade of the Annular Core Research Reactor (ACRR) at Sandia National Laboratories for 2 to 4 MWt. The CHF productions are based on the University of New Mexico's (UNM)-CHF correlations in conjunction with the Global Conditions Hypothesis (GCH). Results indicate that for the range of inlet water temperature of 293 to 333 K, CHFR predictions range from 3.9 to 2.1, which is more than sufficient to support the proposed ACRR upgrade

  8. Exhaust emissions of a double annular combustor: Parametric study

    Science.gov (United States)

    Schultz, D. F.

    1974-01-01

    A full scale double-annular ram-induction combustor designed for Mach 3.0 cruise operation was tested. Emissions of oxides of nitrogen, carbon monoxide, unburned hydrocarbons, and smoke were measured over a range of combustor operating variables including reference velocity, inlet air temperature and pressure, and exit average temperature. ASTM Jet-A fuel was used for these tests. An equation is provided relating oxides of nitrogen emissions as a function of the combustor, operating variables. A small effect of radial fuel staging on reducing exhaust emissions (which were originally quite low) is demonstrated.

  9. Interfacial friction in cocurrent upward annular flow. Final report

    International Nuclear Information System (INIS)

    Cocurrent upward annular flow is investigated, with an emphasis on correlating and predicting pressure drop. Attention is given to the characteristics of the liquid flow in the film, and the interaction of the core with the film. Alternate approaches are discussed for correlating suitably defined interfacial friction factors. Both approaches are dependent on knowledge of the entrainment in order to make predictions. Dimensional analysis is used to define characteristic parameters of the flow and an effort is made to determine, to the extent possible, the influences of these parameters on the interfacial friction factor

  10. Annular burnout data from rod-bundle experiments

    International Nuclear Information System (INIS)

    Burnout data for annular flow in a rod bundle are presented for both transient and steady-state conditions. Tests were performed at the Oak Ridge National Laboratory in the Thermal Hydraulic Test Facility (THTF), a pressurized-water loop containing an electrically heated 64-rod bundle. The bundle configuration is typical of later generation pressurized-water reactors with 17 x 17 fuel arrays. Both axial and radial power profiles are flat. All experiments were carried out in upflow with subcooled inlet conditions, insuring accurate flow measurement. Conditions within the bundle were typical of those which could be encountered during a nuclear reactor loss-of-coolant accident

  11. Electrorheological damper with annular ducts for seismic protection applications

    Science.gov (United States)

    Makris, Nicos; Burton, Scott A.; Taylor, Douglas P.

    1996-10-01

    This paper presents the design, analysis, testing and modeling of an electrorheological (ER) fluid damper developed for vibration and seismic protection of civil structures. The damper consists of a main cylinder and a piston rod that pushes an ER fluid through a stationary annular duct. The behavior of the damper can be approximated with Hagen - Poiseuille flow theory. The basic equations that describe the fluid flow across an annular duct are derived. Experimental results on the damper response with and without the presence of electric field are presented. As the rate of deformation increases, viscous stresses prevail over field-induced yield stresses and a smaller fraction of the total damper force can be controlled. Simple physically motivated phenomenological models are considered to approximate the damper response with and without the presence of electric field. Subsequently, the performance of a multilayer neural network constructed and trained by an efficient algorithm known as the Dependence Identification Algorithm is examined to predict the response of the electrorheological damper. A combination of a simple phenomenological model and a neural network is then proposed as a practical tool to approximate the nonlinear and velocity-dependent damper response.

  12. Development of Dual Cooled Annular Fuel Temperature Analysis Program

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yong Sik; Shin, C. H.; Bang, J. G.; Kim, D. H.; Kim, S. K.; Lim, I. S.; Koo Yang Hyun [KAERI, Daejeon (Korea, Republic of)

    2010-09-15

    To calculate the temperature distribution of dual cooled annular fuel, the DUOS program has been developed. Various thermal hydraulic models to determine the inner channel and outer channel flow distribution were established based on equal pressure drop condition at the top of fuel rod. The effect of gap width change was considered by employing thermal deformation model of pellet and claddings. Heat conduction model in the pellet was solved by finite difference method to consider burnup and power difference according to pellet radius. Pellet temperature model was validated by comparison with calculated temperature profile, which was determined by analytical solution of heat conduction equation under controlled input condition. Accuracy of thermal hydraulic models of DUOS were validated by core sub-channel analysis code MATRA-AF. Coolant bulk temperature of inner/outer channel and pressure drop prediction results of DUOS program show good agreement with that of MATRA-AF. Further models should be added in DUOS program to describe dual cooled annular fuel in-pile behavior, but basic thermal analysis structure has been established successfully

  13. Development of Dual Cooled Annular Fuel Temperature Analysis Program

    International Nuclear Information System (INIS)

    To calculate the temperature distribution of dual cooled annular fuel, the DUOS program has been developed. Various thermal hydraulic models to determine the inner channel and outer channel flow distribution were established based on equal pressure drop condition at the top of fuel rod. The effect of gap width change was considered by employing thermal deformation model of pellet and claddings. Heat conduction model in the pellet was solved by finite difference method to consider burnup and power difference according to pellet radius. Pellet temperature model was validated by comparison with calculated temperature profile, which was determined by analytical solution of heat conduction equation under controlled input condition. Accuracy of thermal hydraulic models of DUOS were validated by core sub-channel analysis code MATRA-AF. Coolant bulk temperature of inner/outer channel and pressure drop prediction results of DUOS program show good agreement with that of MATRA-AF. Further models should be added in DUOS program to describe dual cooled annular fuel in-pile behavior, but basic thermal analysis structure has been established successfully

  14. Design Attributes and Scale Up Testing of Annular Centrifugal Contactors

    Energy Technology Data Exchange (ETDEWEB)

    David H. Meikrantz; Jack D. Law

    2005-04-01

    Annular centrifugal contactors are being used for rapid yet efficient liquid- liquid processing in numerous industrial and government applications. Commercialization of this technology began eleven years ago and now units with throughputs ranging from 0.25 to 700 liters per minute are readily available. Separation, washing, and extraction processes all benefit from the use of this relatively new commercial tool. Processing advantages of this technology include: low in-process volume per stage, rapid mixing and separation in a single unit, connection-in-series for multi-stage use, and a wide operating range of input flow rates and phase ratios without adjustment. Recent design enhancements have been added to simplify maintenance, improve inspection ability, and provide increased reliability. Cartridge-style bearing and mechanical rotary seal assemblies that can include liquid-leak sensors are employed to enhance remote operations, minimize maintenance downtime, prevent equipment damage, and extend service life. Clean-in-place capability eliminates the need for disassembly, facilitates the use of contactors for feed clarification, and can be automated for continuous operation. In nuclear fuel cycle studies, aqueous based separations are being developed that efficiently partition uranium, actinides, and fission products via liquid-liquid solvent extraction. Thus, annular centrifugal contactors are destined to play a significant role in the design of such new processes. Laboratory scale studies using mini-contactors have demonstrated feasibility for many such separation processes but validation at an engineering scale is needed to support actual process design.

  15. Investigation of azimuthal staging concepts in annular gas turbines

    Science.gov (United States)

    Noiray, Nicolas; Bothien, Mirko; Schuermans, Bruno

    2011-10-01

    In this work, the influence of azimuthal staging concepts on the thermoacoustic behavior of annular combustion chambers is assessed theoretically and numerically. Staging is a well-known and effective method to abate thermoacoustic pulsations in combustion chambers. However, in the case of, for example, fuel staging the associated inhomogeneity of equivalence ratio may result in increased levels of NOx emissions. In order to minimize this unwanted effect a staging concept is required in which the transfer functions of the burners are changed while affecting the equivalence ratio as little as possible. In order to achieve this goal, a theoretical framework for predicting the influence of staging concepts on pulsations has been developed. Both linear and nonlinear analytical approaches are presented and it is shown that the dynamics of azimuthal modes can be described by coupled Van der Pol oscillators. A criterion based on the thermoacoustic coupling strength and on the asymmetry degree provides the modal behavior in the annular combustor, i.e. standing or traveling waves. The model predictions have been verified by numerical simulations of a heavy-duty gas turbine using an in-house thermoacoustic network-modeling tool. The interaction between the heat release of the flame and the acoustic field was modeled using measured transfer functions and source terms. These numerical simulations confirmed the original theoretical considerations.

  16. The Growth of Instabilities in Annular Liquid Sheets

    Energy Technology Data Exchange (ETDEWEB)

    Duke, Daniel J.; Honnery, Damon R; Soria, Julio

    2015-11-01

    An annular liquid sheet surrounded by parallel co-flowing gas is an effective atomiser. However, the initial instabilities which determine the primary break-up of the liquid sheet are not well understood. Lack of agreement on the influence of the boundary conditions and the non-dimension scaling of the initial instability persists between theoretical stability analyses and experiments. To address this matter, we have undertaken an experimental parametric study of an aerodynamically-driven, non-swirling annular water sheet. The effects of sheet thickness, inner and outer gas-liquid momentum ratio were investigated over an order of magnitude variation in Reynolds and Weber number. From high-speed image correlation measurements in the near-nozzle region, we propose new empirical correlations for the frequency of the instability as a function of the total gas-liquid momentum ratio, with good non-dimensional collapse. From analysis of the instability velocity probability densities, we find two persistent and distinct superimposed instabilities with different growth rates. The first is a short-lived, rapidly saturating sawtooth-like instability. The second is a slower-growing stochastic instability which persists through the break-up of the sheet. The presence of multiple instabilities whose growth rates do not strongly correlate with the shear velocities may explain some of the discrepancies between experiments and stability analyses.

  17. Study on annular mist flow in pipe, 1

    International Nuclear Information System (INIS)

    An annular mist flow using air and water at room temperature has been studied experimentally in a vertical pipe with a nozzle along the axis of the pipe for supplying liquid. Observations were made of flow patterns of liquid on the inner surface of the pipe, and measurements were made of pressure losses in pipe, profiles of radial distribution of liquid droplets and total flow rates of the liquid droplets. Changes of these four factors along the pipe were measured in the non-equilibrium region. It was found that the non-equilibrium length should be decided by a position where any changes in the four factors mentioned above could not be recognized in the axial direction. For relatively high velocities of air, i.e., for apparent gaseous Reynolds number R sub(ego) >= 9.4 x 104, it was ascertained that the annular mist flow reached equilibrium at a distance of 170 - 190 diameters from the nozzle outlet when apparent liquid Reynolds number R sub(elo) = 62.1 - 183.6. (author)

  18. A Compact Annular Ring Microstrip Antenna for WSN Applications

    Directory of Open Access Journals (Sweden)

    Daihua Wang

    2012-06-01

    Full Text Available A compact annular ring microstrip antenna was proposed for a wireless sensor network (WSN application in the 2.4 GHz band. In this paper the major considerations of the conformal antenna design were the compact size and the impact on antenna’s performance of a steel installation base. By using a chip resistor of large resistance (120 Ω the antenna size was reduced to 38% of that a conventional annular ring patch antenna. With the addition of the steel installation base the resonant frequency of the antenna increases about 4.2% and the bandwidth reduces from 17.5% to 11.7% by adjusting the load resistance simultaneously. Several key parameters were discussed and optimized, and the antenna was fabricated and its performance measured. The antenna is well matched at 2.4 GHz with 34.2 dB return loss and –2.5 dBi peak gain. Meanwhile, it exhibits excellent radiation patterns with very low cross-polarization levels.

  19. Plane Mercury librations

    Science.gov (United States)

    Barkin, Yu. V.; Ferrandiz, J. M.

    2009-04-01

    theory of Mercury librations in longitude by using three characteristics of Mercury rotation determined in the paper [3]. Two from these parameters are values of angle of librations in longitude and angular velocity in moment of passage of perihelion of Mercury orbit on 17 April 2002: (^g)0 = 0007 ± 0001, (^?•? )0 = (2.10± 0.06)•? ars/d. Third parameter determined in [3] is a dynamical coefficient: K = (B -A)•(4Cm ) = (5.08± 0.30) × 10-5. B > A are principal moment of inertia, corresponding to equatorial axes of inertia; Cm is a polar moment of inertia of the mantle of Mercury. 1 Analytical theory of plane Mercury librations. This theory describes forced and free librations of Mercury in longitude in the frame of plane problem about resonant librations of Mercury considered or as non-spherical rigid body, or as system of rigid non-spherical mantle and liquid ellipsoidal core. Saving the main terms for the perturbations of angle of librations ^g and angular velocity ^? in both mentioned cases we will have formulae [6]: ^g = K(E sin M + E sin2M + E sin 3M + E sin4M + E sin5M ) 1 2 3 4 5+K0 sin(E šKM- - φ) (A)

  20. Core-annular flow through a horizontal pipe: Hydrodynamic counterbalancing of buoyancy force on core

    NARCIS (Netherlands)

    Ooms, G.; Vuik, C.; Poesio, P.

    2007-01-01

    A theoretical investigation has been made of core-annular flow: the flow of a high-viscosity liquid core surrounded by a low-viscosity liquid annular layer through a horizontal pipe. Special attention is paid to the question of how the buoyancy force on the core, caused by a density difference betwe

  1. A magnetorheological valve with both annular and radial fluid flow resistance gaps

    International Nuclear Information System (INIS)

    In order to increase the efficiency of magnetorheological (MR) valves, Ai et al (2006) proposed an MR valve simultaneously possessing annular and radial fluid flow resistance channels with the assumption that the magnetic flux densities at the annular and radial fluid flow gaps are identical. In this paper, an MR valve simultaneously possessing annular and radial fluid flow resistance channels is designed, fabricated, modeled and tested. A model for the developed MR valve is produced and its performances are theoretically predicted based on the average magnetic flux densities in the annular and radial fluid flow gaps through finite element analysis. The theoretical results for the developed MR valve are compared with the experimental results. In addition, the performances of the developed MR valve are theoretically and experimentally compared with those of the MR valve with only annular fluid flow gaps. It has been shown that the theoretical results match well with the experimental results. Mainly attributed to the radial fluid flow gaps, the pressure drops across the MR valve with both annular and radial fluid flow gaps are larger than those across the MR valve with only annular fluid flow gaps for varying valve parameters. The radial fluid flow gaps in the MR valve can reach a higher efficiency and larger controllable range than those by annular fluid flow gaps to some extent

  2. Analytical solution of neutron transport equation in an annular reactor with a rotating pulsed source

    International Nuclear Information System (INIS)

    In this study, an analytical solution of the neutron transport equation in an annular reactor is presented with a short and rotating neutron source of the type S(x) δ (x- Vt), where V is the speed of annular pulsed reactor. The study is an extension of a previous study by Williams [12] carried out with a pulsed source of the type S(x) δ (t). In the new concept of annular pulsed reactor designed to produce continuous high flux, the core consists of a subcritical annular geometry pulsed by a rotating modulator, producing local super prompt critical condition, thereby giving origin to a rotating neutron pulse. An analytical solution is obtained by opening up of the annular geometry and applying one energy group transport theory in one dimension using applied mathematical techniques of Laplace transform and Complex Variables. The general solution for the flux consists of a fundamental mode, a finite number of harmonics and a transient integral. A condition which limits the number of harmonics depending upon the circumference of the annular geometry has been obtained. Inverse Laplace transform technique is used to analyse instability condition in annular reactor core. A regenerator parameter in conjunction with perimeter of the ring and nuclear properties is used to obtain stable and unstable harmonics and to verify if these exist. It is found that the solution does not present instability in the conditions stated in the new concept of annular pulsed reactor. (author)

  3. Multiple lesions of granuloma annulare on the hand in a patient with scabies

    Directory of Open Access Journals (Sweden)

    Al Aboud K

    2011-08-01

    Full Text Available Khalid Al Aboud1, Daifullah Al Aboud21Department of Dermatology, King Faisal Hospital, Makkah; 2Department of Dermatology, Taif University, Taif, Kingdom of Saudi ArabiaAbstract: Granuloma annulare induced by scabies infection has been described previously in three patients. In this report, we share our observation of a fourth case.Keywords: granuloma annulare, scabies, skin

  4. DC intrinsic Josephson effect in 1{mu}m-lateral-size annular Bi-2212 stacks

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.J.; Yamashita, T. [Tohoku Univ., Sendai (Japan). Research Inst. of Electrical Comunication; Latyshev, Y.I.; Pavlenko, V.N. [Tohoku Univ., Sendai (Japan); Inst of Radio-Engineerig and Electronics Russian Academic of Sciences, Moscow (Russian Federation)

    1999-11-10

    Small annular junctions were the subjects of particular interest last decade because of possibility of flux trapping (see, e.g. [1]). Related magnetic field can contain radial component affecting Josephson critical current. Here we report on the first studies of intrinsic dc Josephson effect [2] in small annular type Bi-2212 mesas and its sensitivity to the trapped flux. (translated by NEDO)

  5. In-Reactor Densification of Dual Cooled Annular Fuel Pellet during Irradiation Test at HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Young Woo; Kim, Dong Joo; Kwon, Hyoung Mun; Kim, Keon Sik; Kim, Jong Hun; Oh, Jang Soo; Yang, Jae Ho; Koo, Yang Hyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    These advantages result in a considerably low pellet centerline temperature. Because of this considerably low pellet temperature, in-reactor behavior of an annular pellet, such as densification and swelling may be significantly different from that of the conventional PWR solid pellet. Since the pellet temperature of an annular fuel rod is lower than that of a PWR solid fuel rod by several hundred degrees, the in-reactor densification and swelling of a dual cooled annular fuel pellet might be considered as athermal phenomena due to a low pellet temperature. In order to investigate the in-reactor behavior of the annular UO{sub 2} pellet, HANARO irradiation test was planned and conducted for annular pellets with 5 different types. Post irradiation test is being carried out in the KAERI's PIE facility. In this study, we are going to report the preliminary results of PIE test on the inreactor densification behavior of a dual cooled annular fuel pellet. Irradiation test of dual cooled annular UO{sub 2} pellet was conducted at the OR-4 hole in HANARO by using a non-instrumented test rig. The preliminary results of PIE test on the in-reactor densification behavior showed that the irradiated pellets densified much more than expected values based on MATPRO relations of inreactor densification at low temperature in the annular pellet with low initial sintered density. It might be attributed to the higher fission rate during HANARO irradiation.

  6. Effect of myocardial ischemia and nitroglycerin on systolic time intervals in the segmental myocardium

    Directory of Open Access Journals (Sweden)

    Haraoka,Shoichi

    1978-04-01

    Full Text Available Effects of ischemia and nitroglycerin on systolic time intervals in the segmental myocardial length were studied in anesthetized open-chest dogs. Two strain-gauges were sutured on the surface of the left ventricular wall; one was in the central area perfused by the left circumflex coronary artery (LCX and the other was in the area perfused by the left anterior descending coronary artery. LCX was partially occluded with a screw type constrictor to the degree at which reactive hyperemia after the transient total coronary occlusion almost disappeared. After the hemodynamics stabilized nitroglycerin (20 microgram/kg was injected into the femoral vein. In the ischemic area, contraction time was shortened and precontraction time was prolonged in association with an elongation of end-systolic and early systolic segment-length, respectively. The systolic time intervals in the ischemic segment were improved as a result of the recovery in the segment-length toward the control. The results suggest the usefulness of analyzing the segmental myocardial systolic time intervals for verifying the asynchronous contraction of the ventricle and the favourable effects of nitroglycerin on segmental myocardial function in the ischemic area.

  7. Left ventricular systolic response to exercise in patients with systemic hypertension without left ventricular hypertrophy.

    Science.gov (United States)

    Christian, T F; Zinsmeister, A R; Miller, T D; Clements, I P; Gibbons, R J

    1990-05-15

    Supine exercise radionuclide angiography was performed in 367 men to assess left ventricular (LV) systolic response to exercise; 58 had systemic hypertension without LV hypertrophy on a resting electrocardiogram and 309 were normotensive. All patients met the following criteria defining a low pretest likelihood of coronary artery disease: age less than 50 years; normal electrocardiographic response to exercise; absence of typical or atypical chest pain; and exercise heart rate greater than 120 beats/min. Patients taking beta-receptor blockers were excluded. There were no significant differences between hypertensive and normotensive groups in peak exercise heart rate, workload or exercise duration. However, hypertensive patients had significantly higher peak exercise systolic blood pressures and peak exercise rate-pressure products. There were no differences between patients with and without hypertension in resting ejection fraction, peak exercise ejection fraction (hypertensive patients 0.71 +/- 0.01, normotensive patients 0.70 +/- 0.05) or change in ejection fraction at peak exercise (hypertensive patients 0.07 +/- 0.01, normotensive patients 0.07 +/- 0.04). Diastolic and systolic ventricular volumes tended to be smaller in the hypertensive patients, but the difference was not statistically significant. The change in systolic volume with exercise was similar in the 2 groups (hypertensive -10 +/- 3 ml/m2, normotensive -10 +/- 1 ml/m2). In the absence of electrocardiographic evidence of LV hypertrophy, systemic hypertension does not influence LV systolic response to exercise. PMID:2140008

  8. Annular core liquid-salt cooled reactor with multiple fuel and blanket zones

    Science.gov (United States)

    Peterson, Per F.

    2013-05-14

    A liquid fluoride salt cooled, high temperature reactor having a reactor vessel with a pebble-bed reactor core. The reactor core comprises a pebble injection inlet located at a bottom end of the reactor core and a pebble defueling outlet located at a top end of the reactor core, an inner reflector, outer reflector, and an annular pebble-bed region disposed in between the inner reflector and outer reflector. The annular pebble-bed region comprises an annular channel configured for receiving pebble fuel at the pebble injection inlet, the pebble fuel comprising a combination of seed and blanket pebbles having a density lower than the coolant such that the pebbles have positive buoyancy and migrate upward in said annular pebble-bed region toward the defueling outlet. The annular pebble-bed region comprises alternating radial layers of seed pebbles and blanket pebbles.

  9. Entrance and exit region friction factor models for annular seal analysis. Ph.D. Thesis

    Science.gov (United States)

    Elrod, David Alan

    1988-01-01

    The Mach number definition and boundary conditions in Nelson's nominally-centered, annular gas seal analysis are revised. A method is described for determining the wall shear stress characteristics of an annular gas seal experimentally. Two friction factor models are developed for annular seal analysis; one model is based on flat-plate flow theory; the other uses empirical entrance and exit region friction factors. The friction factor predictions of the models are compared to experimental results. Each friction model is used in an annular gas seal analysis. The seal characteristics predicted by the two seal analyses are compared to experimental results and to the predictions of Nelson's analysis. The comparisons are for smooth-rotor seals with smooth and honeycomb stators. The comparisons show that the analysis which uses empirical entrance and exit region shear stress models predicts the static and stability characteristics of annular gas seals better than the other analyses. The analyses predict direct stiffness poorly.

  10. Gravitational Couplings for Gop-Planes and y-Op-Planes

    CERN Document Server

    Ospina-Giraldo, J F

    2000-01-01

    The Wess-Zumino actions for generalized orientifold planes (GOp-planes) and y-deformed orientifold planes (yOp-planes) are presented and two series power expantions are realized from whiches processes that involves GOp-planes,yOp-planes, RR-forms, gravitons and gaugeons, are obtained. Finally non-standard GOp-planes and y-Op-planes are showed.

  11. Conceptual Design of Wave Plane

    DEFF Research Database (Denmark)

    Frigaard, Peter; Trewers, Andrew; Kofoed, Jens Peter;

    The Wave Plane is a patented Wave Energy device of the overtopping type, designed to capture potential as well as kinetic energy. This is as such different to other overtopping devices, who usually only focus on potential energy. If Wave Plane A/S can deliver the turbine technology to utilize both...

  12. Pulsed Doppler Tissue Imaging for Assessment of Left Ventricular Systolic and Diastolic Synchronicity in Normal Subjects

    Institute of Scientific and Technical Information of China (English)

    Yang Li; Wu Wei; Wang Jingfeng; Zhang Xiaoling

    2006-01-01

    Objectives To quantitatively analyze the longitudinal myocardial systolic and diastolic velocities and time intervals of the left ventricle in normal subjects, and to explore the value of pulsed Doppler tissue imaging (DTI) for the assessment of left ventricular systolic and diastolic synchronicity.Methods Twenty and six healthy subjects were studied by pulsed DTI. The septal and lateral, anterior and inferior walls of the left ventricle were displayed respectively, and basal and middle segments of each wall were selected for myocardial motion spectrum sampling. DTI parameters were: peak systolic myocardial velocity (s), regional pre-ejection period (PEP), time to the peak of s wave (Ts), regional ejection time (ET); peak early diastolic velocity (e),peak late diastolic velocity (a), e/a ratio, time to the beginning of e wave (QE), time to the peak of e wave (Te) and regional isovolumic relaxation time (IVRT).Results The e and e/a were significantly different among basal segments, and s and e/a were significantly different among middle segments, with the highest value in lateral segments and the lowest value in septal segments. The s, e and a were all significantly higher in basal segments than middle segments. None of the systolic time intervals (PEP, Ts and ET) and diastolic time intervals (QE, Te and IVRT) were significantly different among basal segments and middle segments,neither were they when basal segment was compared with middle segment. Conclusions In normal subjects, the longitudinal myocardial systolic and diastolic velocities of the left ventricle are not homogeneous, but the contraction and relaxation are highly synchronized. Pulsed DTI can be used to quantitatively analyze the systolic and diastolic synchronicity of the heart.

  13. The reliability of toe systolic pressure and the toe brachial index in patients with diabetes

    Directory of Open Access Journals (Sweden)

    Perrin Byron M

    2010-12-01

    Full Text Available Abstract Background The Ankle Brachial Index is a useful clinical test for establishing blood supply to the foot. However, there are limitations to this method when conducted on people with diabetes. As an alternative to the Ankle Brachial Index, measuring Toe Systolic Pressures and the Toe Brachial Index have been recommended to assess the arterial blood supply to the foot. This study aimed to determine the intra and inter-rater reliability of the measurement of Toe Systolic Pressure and the Toe Brachial Index in patients with diabetes using a manual measurement system. Methods This was a repeated measures, reliability study. Three raters measured Toe Systolic Pressure and the Toe Brachial Index in thirty participants with diabetes. Measurement sessions occurred on two occasions, one week apart, using a manual photoplethysmography unit (Hadeco Smartdop 45 and a standardised measurement protocol. Results The mean intra-class correlation for intra-rater reliability for toe systolic pressures was 0.87 (95% LOA: -25.97 to 26.06 mmHg and the mean intra-class correlation for Toe Brachial Indices was 0.75 (95% LOA: -0.22 to 0.28. The intra-class correlation for inter-rater reliability was 0.88 for toe systolic pressures (95% LOA: -22.91 to 29.17.mmHg and 0.77 for Toe Brachial Indices (95% LOA: -0.21 to 0.22. Conclusion Despite the reasonable intra-class correlation results, the range of error (95% LOA was broad. This raises questions regarding the reliability of using a manual sphygmomanometer and PPG for the Toe Systolic Pressure and Toe Brachial Indice.

  14. Improvement of systolic and diastolic heart function after physical training in sedentary women

    DEFF Research Database (Denmark)

    Andersen, Lars Juul; Hansen, P R; Søgaard, P;

    2010-01-01

    The present study examined the cardiac effects of football training and running for inactive pre-menopausal women by standard echocardiography and tissue Doppler imaging. Thirty-seven subjects were randomized to two training groups (football: FG; n=19; running; RG; n=18) training 1 h with equal.......0+/-1.3 mm (P<0.05). Right ventricle diameter increased by 12% in FG and 10% in RG (P<0.05). Tissue Doppler imaging demonstrated increased left ventricular systolic and diastolic performances in both training groups. Peak systolic velocity increased by 26% in FG and 17% in RG (P<0.05) and left ventricular...

  15. FPGA IMPLEMENTATION OF RSA PUBLIC-KEY CRYPTOGRAPHIC COPROCESSOR BASED ON SYSTOLIC LINEAR ARRAY ARCHITECTURE

    Institute of Scientific and Technical Information of China (English)

    Wen Nuan; Dai Zibin; Zhang Yongfu

    2006-01-01

    In order to make the typical Montgomery's algorithm suitable for implementation on FPGA, a modified version is proposed and then a high-performance systolic linear array architecture is designed for RSA cryptosystem on the basis of the optimized algorithm. The proposed systolic array architecture has distinctive features, i.e. not only the computation speed is significantly fast but also the hardware overhead is drastically decreased. As a major practical result, the paper shows that it is possible to implement public-key cryptosystem at secure bit lengths on a single commercially available FPGA.

  16. COMPARISON OF ENALAPRIL AND PERINDOPRIL IN PATIENTS WITH ARTERIAL HYPERTENSION AND LEFT VENTRICLE SYSTOLIC DYSFUNCTION

    OpenAIRE

    Yu. I. Grinshtein; O. L. Barbarash; D. A. Yakhontov; A. E. Popelysheva; V. V. Shabalin; N. B. Osetrova

    2016-01-01

    Aim. To compare efficacy of enalapril and perindopril in patients with arterial hypertension (HT) and left ventricle systolic dysfunction.Material and methods. Patients (n=51) with HT and left ventricle systolic dysfunction (ejection fraction<45%) were included in the prospective open randomized comparative study. Patients were randomized into 2 groups of therapy with enalapril 10-20 mg BID (n=25) or with perindopril 4-8 mg OD (n=26). Hydrochlorothiazide (12,5-25 mg OD) was added in case o...

  17. Liquid transfer and entrainment correlation for droplet-annular flow

    International Nuclear Information System (INIS)

    A correlation for the amount of entrained liquid in annular flow has been developed from a simple model and experimental data. There are basically two different regions of entrainment, namely, the entrance and quasi-equilibrium regions. The correlation for the equilibrium region is expressed in terms of the dimensionless gas flux, diameter, cand total liquid Reynolds number. The entrance effect is taken into account by an exponential relaxation function. It has been shown that this new model can satisfactorily correlate wide ranges of experimental data for water. Furthermore, the necessary distance for the development of entrainment is identified. These correlations, therefore, can supply accurate information on entrainment which has not been available previously

  18. Annular elastolytic giant cell granuloma of conjunctiva: A case report

    Directory of Open Access Journals (Sweden)

    Karabi Konar

    2014-01-01

    Full Text Available Annular elastolytic giant cell granuloma is a condition characterized histologically by damaged elastic fibers associated with preponderance of giant cells along with absence of necrobiosis, lipid, mucin, and pallisading granuloma. It usually occurs on sun-damaged skin and hence the previous name actinic granuloma. A similar process occurs on the conjunctiva. Over the past three decades only four cases of conjunctival actinic granuloma have been documented. All the previous patients were females with lesions in nasal or temporal bulbar conjunctiva varying 2-3 mm in size. We report a male patient aged 70 years presenting with a 14 mm × 7 mm fleshy mass on right lower bulbar conjunctiva. Clinical differential diagnoses were lymphoma, squamous cell carcinoma in situ and amyloidosis. Surgical excision followed by histopathology confirmed it to be a case of actinic granuloma. This is the first case of isolated conjunctival actinic granuloma of such a large size reported from India.

  19. An in-house developed annular bright field detection system

    International Nuclear Information System (INIS)

    Annular bright field (ABF) detectors have been developed in the last few years allowing the direct imaging of low-Z atoms from oxygen down to hydrogen. These types of detectors are now available as standard attachments for the latest generation of top-end electron microscopes. However these systems cannot always be installed in previous generation microscopes. In this paper we report the preliminary results of an in-house implementation of a ABF detection system on a CEOS aberration corrected JEOL 2200FS STEM. This has been obtained by exploiting the standard BF detector coupled with a high vacuum compatible, X-ray tight and retractable shadowing mechanism. This results in the acquisition of near zero-angle scattered electrons with inner collection semi-angle from 2.0 mrad to 23 mrad and outer semi-angle in the range from 3.0 mrad to 35 mrad. The characteristics and performances of this ABF detection system are discussed

  20. Mathematical model for multicomponent separations on the continuous annular chromatograph

    International Nuclear Information System (INIS)

    A model for multicomponent separations on ion exchange columns has been adapted for use in studying the performance of the continuous annular chromatograph. The model accurately predicts solute peak positions in the column effluent and qualitatively predicts trends in solute effluent resolution as a function of increasing bandwidth of the solute feed pulse. The major virtues of the model are its simplicity in terms of the calculations involved and the fact that it incorporates the nonlinear solute-resin binding isotherms common in many ion exchange separations. Because dispersion effects are not accounted for in the model, discrepancies exist between the shapes of the effluent peaks predicted by the model and those determined experimentally

  1. Mathematical model for multicomponent separations on the continuous annular chromatograph

    Energy Technology Data Exchange (ETDEWEB)

    Bratzler, R.L.; Begovich, J.M.

    1980-12-01

    A model for multicomponent separations on ion exchange columns has been adapted for use in studying the performance of the continuous annular chromatograph. The model accurately predicts solute peak positions in the column effluent and qualitatively predicts trends in solute effluent resolution as a function of increasing bandwidth of the solute feed pulse. The major virtues of the model are its simplicity in terms of the calculations involved and the fact that it incorporates the nonlinear solute-resin binding isotherms common in many ion exchange separations. Because dispersion effects are not accounted for in the model, discrepancies exist between the shapes of the effluent peaks predicted by the model and those determined experimentally.

  2. Aerodynamic performance of an annular classical airfoil cascade

    Science.gov (United States)

    Bergsten, D. E.; Stauter, R. C.; Fleeter, S.

    1983-01-01

    Results are presented for a series of experiments that were performed in a large-scale subsonic annular cascade facility that was specifically designed to provide three-dimensional aerodynamic data for the verification of numerical-calculation codes. In particular, the detailed three-dimensional aerodynamic performance of a classical flat-plate airfoil cascade is determined for angles of incidence of 0, 5, and 10 deg. The resulting data are analyzed and are correlated with predictions obtained from NASA's MERIDL and TSONIC numerical programs. It is found that: (1) at 0 and 5 deg, the airfoil surface data show a good correlation with the predictions; (2) at 10 deg, the data are in fair agreement with the numerical predictions; and (3) the two-dimensional Gaussian similarity relationship is appropriate for the wake velocity profiles in the mid-span region of the airfoil.

  3. A Novel Design of Magnetorheological Damper with Annular Radial Channel

    Directory of Open Access Journals (Sweden)

    Shisha Zhu

    2016-01-01

    Full Text Available With the development of automotive vibration technology, the semiactive suspension system with adjustable damping force and high reliability is taken seriously. The magnetorheological damper (MRD that applies intelligent material (magnetorheological fluid is the key element of this system. It can achieve a continuous and adjustable damping and then reaches the purpose of comfort. In order to improve the damping effect of MRD, this paper presents a MRD, which has magnetorheological (MR effect along annular radial channel. The paper completely designs the structure and magnetic circuit of MRD. Based on the theory of electromagnetism and MR fluid dynamics, the paper analyzes and tests the external characteristics of the MRD by the MATLAB/Simulink and the vibration experiment. The results compared with ordinary MRD reveal that the damping force obviously increases and has wide adjustable range, thus verifying the reasonableness of the damper design.

  4. Investigation of a low NOx full-scale annular combustor

    Science.gov (United States)

    1982-01-01

    An atmospheric test program was conducted to evaluate a low NOx annular combustor concept suitable for a supersonic, high-altitude aircraft application. The lean premixed combustor, known as the vortex air blast (VAB) concept, was tested as a 22.0-cm diameter model in the early development phases to arrive at basic design and performance criteria. Final demonstration testing was carried out on a full scale combustor of 0.66-m diameter. Variable geometry dilution ports were incorporated to allow operation of the combustor across the range of conditions between idle (T(in) = 422 K, T(out) = 917 K) and cruise (T(in) = 833 K, T(out) - 1778 K). Test results show that the design could meet the program NOx goal of 1.0 g NO2/kg fuel at a one-atmospheric simulated cruise condition.

  5. Development of annular targets for 99MO production-1999

    International Nuclear Information System (INIS)

    The new annular target performed well during irradiation. The target is inexpensive and provides good heat transfer during irradiation. Based on these and previous tests, we conclude that targets with zirconium tubes and either nickel-plated or zinc-plated foils work well. We proved that we could use aluminum target tubes, which are much cheaper and easier to work with than the zirconium tubes. In aluminum target tubes nickel-plated fission-recoil barriers work well and prevent bonding of the foil to the new target tubes during irradiation. Also, zinc-plated and aluminum-foil barriers appear promising in anodized aluminum tubes. Additional tests are anticipated to address such issues as fission-recoil barrier thickness and uranium foil composition. Overall, however, the target was successful and will provide an inexpensive, efficient way to irradiate LEU metal foil for the production of 99Mo

  6. Damping of cylindrical structures subject to annular flow

    International Nuclear Information System (INIS)

    In previous reports theoretical methods have been described for estimating the aerodynamic forces acting on cylinders vibrating laterally when surrounded by an annulus carrying high velocity gas. For a certain restricted set of geometries it is possible to predict whether a particular structure is stable or unstable and to determine the level of aerodynamic damping positive or negative due to the presence of the gas. This report describes experimental work which validates the computer program in which the theoretical methods are embodied; in particular the damping, inertial and decentralising forces acting on a cylinder in an annulus are measured and compared with theory over a range of frequencies from 0 to 25 Hz, and of Reynolds numbers from zero to 104. In addition a summary of simple relationships is provided which can be used to provide credible initial estimates of both the positive and negative damping of cylinders in a range of annular geometries. (author)

  7. Application study on fast extracting plutonium with annular centrifugal extractor

    International Nuclear Information System (INIS)

    An extraction system with annular centrifugal extractors has been designed to separate plutonium. It worked well when centrifugal speed was ranged from 2000 to 8000 r/min and organic-aqueous flow ratio (o/a) ranged from 1/3 to 1, without obvious entraining phenomenon Pu (IV) in 6 mol/L HNO3 solution was fast extracted and separated, using 0.1 mol/L TOPO/Cyclohexane as extraction solvent and 0.01 mol/L oxalic acid as back extraction solvent. The extraction ratio of two stages was larger than 90%, and the back ratio per stage was more than 96%. The extraction system shows fast operating speed and high extraction ratio, therefore it is suitable for fast extracting Pu. (authors)

  8. Annular modes and apparent eddy feedbacks in the Southern Hemisphere

    Science.gov (United States)

    Byrne, Nicholas J.; Shepherd, Theodore G.; Woollings, Tim; Plumb, R. Alan

    2016-04-01

    Lagged correlation analysis is often used to infer intraseasonal dynamical effects but is known to be affected by nonstationarity. We highlight a pronounced quasi 2 year peak in the anomalous zonal wind and eddy momentum flux convergence power spectra in the Southern Hemisphere, which is prima facie evidence for nonstationarity. We then investigate the consequences of this nonstationarity for the Southern Annular Mode and for eddy momentum flux convergence. We argue that positive lagged correlations previously attributed to the existence of an eddy feedback are more plausibly attributed to nonstationary interannual variability external to any potential feedback process in the midlatitude troposphere. The findings have implications for the diagnosis of feedbacks in both models and reanalysis data as well as for understanding the mechanisms underlying variations in the zonal wind.

  9. Intermittent Flow of Granular Matter in an Annular Geometry

    Science.gov (United States)

    Brzinski, Ted; Daniels, Karen E.

    Granular solids can be subjected to a finite stress below which the response is elastic. Above this yield stress, however, the material fails catastrophically, undergoing a rapid plastic deformation. In the case of a monotonically increasing stress the material exhibits a characteristic stick-slip response. We investigate the statistics of this intermittent failure in an annular shear geometry, driven with a linear-ramp torque in order to generate the stick-slip behavior. The apparatus is designed to allow visual access to particle trajectories and inter-particle forces (through the use of photoelastic materials). Additionally, twelve piezoelectric sensors at the outer wall measure acoustic emissions due to the plastic deformation of the material. We vary volume fraction, and use both fixed and deformable boundaries. We measure how the distribution of slip size and duration are related to the bulk properties of the packing, and compare to systems with similar governing statistics.

  10. Periocular granuloma annulare: a case report and review of literature.

    Science.gov (United States)

    Chiang, Katherine; Bhalla, Rohan; Mesinkovska, Natasha A; Piliang, Melissa P; Tamburro, Joan E

    2014-01-01

    Granuloma annulare (GA) is a granulomatous dermatosis that rarely presents on the face and is extremely uncommon in the periocular region. We report our experience with the presentation and management of GA lesions on the eyelids of a 17-year-old girl. We performed a review of published literature and identified 13 cases of pediatric periocular GA. One additional case was identified upon review of all pediatric GA cases at the Cleveland Clinic Foundation. Review of these cases suggests that periocular GA is a benign condition that spontaneously regresses within a few months. GA nodules have a predilection for the upper eyelids. A greater incidence is noted in African American children. Awareness of the self-resolving nature of this condition can prevent unnecessary surgical excisions in affected children. PMID:23551387

  11. Impaired resting myocardial annular velocities are independently associated with mental-stress induced ischemia in patients with coronary heart disease

    Science.gov (United States)

    Ersboll, Mads; Enezi, Fawaz Al; Samad, Zainab; Sedberry, Brenda; Boyle, Stephen H.; O’Connor, Christopher; Jiang, Wei; Velazquez, Eric J.

    2014-01-01

    Structured Abstract Objectives To investigate the association between resting myocardial function as assessed by tissue Doppler myocardial velocities (TDI) and the propensity for developing mental stress induced ischemia (MSIMI). Background Tissue Doppler myocardial velocities detect preclinical cardiac dysfunction and clinical outcome in a range of conditions. However, little is known about the interrelationship between myocardial velocities and the propensity for developing MSIMI versus exercise stress induced myocardial ischemia (ESIMI). Methods Resting annular myocardial TDI velocities were obtained in 225 patients with known coronary heart disease who were subjected to both conventional exercise stress test as well as a battery of 3 mental stress tests. Diastolic early (e′) and late (a′) as well as systolic (s′) velocities were obtained and eas-index, an integrated measure of myocardial velocities, was calculated as e′/(a′ x s′). MSIMI was defined as 1) development or worsening of regional wall motion abnormality, 2) reduction in left ventricular ejection fraction ≥ 8%, and/or 3) ischemic ST-segment changes during one or more of the three mental stress tests. Results A total of 98 (43.7%) out of 225 patients exhibited MSIMI. Patients developing MSIMI had significantly lower s′ (7.0±1.7 vs 7.5±1.2, p=0.016) and a′ (8.9±1.8 vs 10.0±1.9, p<0.001) at baseline whereas e′ did not differ (6.5±1.7 vs. 6.5±1.8, p=0.85). Furthermore, the eas-index was significantly higher (0.11±0.04 vs. 0.09±0.03, p<0.0001).The eas-index remained significantly associated with the propensity for developing MSIMI (Odds ratio per 0.05 unit increase: 1.85; 95%CI: 1.21–2.82, p=0.004) after adjustment of resting LVEF, resting wall motion index score, gender and social circumstances of living. There was no association between resting eas-index and ESIMI. Conclusion MSIMI but not ESIMI is independently associated with resting abnormalities in myocardial systolic

  12. Magnetically guided free surface annular NaK flow experiment

    International Nuclear Information System (INIS)

    In order to gain basic information on the magnetically guided liquid metal Li waterfall type blanket concept for ICF reactors and liquid metal Li free surface flow for FMIT type accelerator target, an experimental study was conducted by using LINAK (NaK: 50 l, Ar: 0-0.3 MPa) device. A 45 mm O.D. and 25 mm I.D. annular free jet of NaK, which flowed downwards coaxially through a superconducting magnet (2.7 Tmax, B=0.38 T at the nozzle exit), was formed in vacuum chamber and at the nozzle exit where magnetic flux density B was divergent. The experiment covered ranges of U=0.5-2.5 m/s and B=0-0.38 T at the nozzle exit. Photographic and VTR observations were made on the behavior of outer surface of annular flow. The results are summarized as follows. (1) When B=0 T, the downward flow was rather convergent due to the surface tension. (2) By applying B, the flow became divergent like a cone shell and more stable. The divergent half angle increased with intensifying B. (3) The experimental results on the flow divergence agreed fairly well with the numerical analysis which took into account the MHD force, the surface tension and the gravitational force. (4) No growth of outer surface disturbance occurred within an attained maximum divergent half angle of 8deg or less. The results are considered to be encouraging for applying to ICF blanket and FMIT type target. (author)

  13. Z-pinch of an annular gas jet

    International Nuclear Information System (INIS)

    The implosion and thermalization of an annular argon plasma is investigated. The plasma is produced by the z-pinch of an annular jet of argon gas, using a marx bank-transmission line system which delivers a peak current of 415 kA in 200 ns. The annulus implodes from its initial diameter of 2.5 cm and reaches a peak velocity of approx.2.8 x 107 cm/sec. Measurements of the plasma's radius, thickness, electron density, and average ionization state as a function of time are performed. When the imploding plasma reaches the axis, an 8 ns pulse of soft (0.1-1 keV) x rays is emitted. X rays with energies between 1 and 6 keV are also observed, and are emitted in a single pulse 2 to 5 ns wide. The thermalized plasma is inhomogeneous along the axial direction; vacuum ultraviolet spectroscopy indicates that some regions are approx.270 eV, with Ar XIV in abundance, while x-ray spectroscopy indicates that other regions of the plasma have only highly ionized argon (XVI-XVIII). Although a thermal interpretation of the x-ray spectra would indicate an electron temperature of approx.1 keV, there is evidence that an energetic beam of electrons develops in the thermalized plasma. When this beam is included in the analysis of the x-ray spectra, it is found that the temperature in the hot spots could be as low as 400 eV. The electron density in the thermalized plasma is estimated to be greater than or equal to 1020 cm-3

  14. Annular fuel pin heat transfer and lumped model correction

    International Nuclear Information System (INIS)

    Fuel pin heat transfer studies are important in nuclear reactor accident analysis. Based on the requirement of accuracy and the speed of the computation, a simple lumped heat transfer method or detailed numerical methods are chosen to solve the heat transfer equations. In a nuclear reactor design calculations, accuracy of the solution is very important than the speed. In a nuclear reactor simulator, the speed is important. Lumped model assumes fuel pellet is solid without central hole and the heat transfer coefficient is constant across the fuel pin. In the present study a new modified lumped heat transfer model is developed to consider the annular fuel pin's central hole, and the heat transfer coefficient is made as a function of average fuel pin temperature. Transient analyses are carried out with the above said modifications for a typical LMFBR annular fuel pin. The results of lumped heat transfer model are almost matching with the accurate numerical schemes like Crank-Nicolson method. Comparisons of results with Crank-Nicolson methods are good for small step reactivity addition, ramp reactivity insertion and large step reactivity addition, ramp reactivity insertion with and without reactivity feedbacks. Comparisons of results are good for LOFA also, with and without reactivity feedbacks. With the consideration of reactivity feedbacks, fuel temperature calculated through the present modified lumped model is matching well with Crank-Nicolson methods, and the nominal power also matching well. The modified lumped heat transfer model can be used in nuclear reactor simulation studies and in conservative accident analyses where fastness of the solution is a matter of concern. (author)

  15. Measurement of Quasi-periodic Oscillating Flow Motion in Simulated Dual-cooled Annular Fuel Bundle

    International Nuclear Information System (INIS)

    In order to increase a significant amount of reactor power in OPR1000, KAERI (Korea Atomic Energy Research Institute) has been developing a dual-cooled annular fuel. The dual-cooled annular fuel is simultaneously cooled by the water flow through the inner and the outer channels. KAERI proposed the 12x12 dual-cooled annular fuel array which was designed to be structurally compatible with the 16x16 cylindrical solid fuel array by maintaining the same array size and the guide tubes in the same locations, as shown in Fig. 1. In such a case, due to larger outer diameter of dual-cooled annular fuel than conventional solid fuel, a P/D (Pitch-to-Diameter ratio) of dual cooled annular fuel assembly becomes smaller than that of cylindrical solid fuel. A change in P/D of fuel bundle can cause a difference in the flow mixing phenomena between the dual-cooled annular and conventional cylindrical solid fuel assemblies. In this study, the rod bundle flow motion appearing in a small P/D case is investigated preliminarily using PIV (Particle Image Velocimetry) for dual-cooled annular fuel application

  16. Numerical Simulation of the Laval Annular Mechanical Foam Breaker for Foam Drilling

    Directory of Open Access Journals (Sweden)

    Pin Lu Cao

    2013-12-01

    Full Text Available The Computational Fluid Dynamics (CFD code, Fluent, is employed to simulate the flow phenomena inside the annular foam breaker in order to improve its performance. The numerical simulation results show that the value and the distribution of the negative pressure are very important for the annular foam breaker. The design of the Laval nozzle not only can increase the fluid velocity, but also can reduce the pressure value from -30.2 to -50.3 kPa compared with the common annular nozzle foam breaker. In order to improve the range of the internal negative pressure, the two-stage Laval annular foam breaker is designed in this study. The analysis results show the distance between the two annular slit have greatly influence on its performance. There is a small overlap area between the two negative pressure zones generated by the two annular slits. The smaller the value distance is, the larger the overlap zone is. When the value of the distance decreases to 50 mm, the minimum negative pressure can be reduced to approximately -65.5 kPa. Meanwhile, the range of the internal negative pressure is larger than the single Laval annular foam breaker, which is benefit to break foam.

  17. Thermal hydraulic performance assessment of dual-cooled annular nuclear fuel for OPR-1000

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Chang-Hwan, E-mail: shinch@kaeri.re.kr [LWR Fuel Development Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); Chun, Tae-Hyun, E-mail: thchun@kaeri.re.kr [LWR Fuel Development Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); Oh, Dong-Seok, E-mail: dsoh1@kaeri.re.kr [LWR Fuel Development Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); In, Wang-Kee, E-mail: wkin@kaeri.re.kr [LWR Fuel Development Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-Daero, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer A thermal hydraulic performance of a 12 Multiplication-Sign 12 annular fuel array is evaluated. Black-Right-Pointing-Pointer The subchannel analysis code for the dual-cooled annular fuel, MATRA-AF is validated. Black-Right-Pointing-Pointer We evaluate the sensitivity for geometry tolerances and operating parameter. Black-Right-Pointing-Pointer We decide the essential design parameters to uprate the power generation by dual-cooled annular fuel. Black-Right-Pointing-Pointer A thermal margin amount accommodating a 20% power-uprate seems viable. - Abstract: An internally and externally cooled annular fuel was proposed for an advance PWR, which can endure substantial power uprating. KAERI is pursuing the development for a reloading of power uprated annular fuel for the operating PWR reactors of OPR-1000. In this paper, the characteristics and verification of the MATRA-AF are described. The thermal hydraulic performance of a 12 Multiplication-Sign 12 annular fuel is calculated for the major design parameters and its performance is compared against the reference 16 Multiplication-Sign 16 cylindrical fuel assembly. In particular, the enhancements of the thermal hydraulic performance of dual-cooled annular fuel are estimated for the 100% normal power reactor core. The purpose of this study is to estimate a normal power for OPR-1000 with dual-cooled annular fuel, and ultimately to assess the feasibility of 120% core power. The parametric study was carried out for the fuel rod dimension, gap conductance, thermal diffusion coefficients, and pressure loss of the spacer grids. As a result of the analysis on the nominal power, annular fuel showed a sufficient margin available on DNB and fuel pellet temperature relative to cylindrical fuel. The margin amount seems accommodating a 20% power-uprate seems viable.

  18. Hydraulic lift-off issues for application of high performance annular fuels in pressurized water reactors

    International Nuclear Information System (INIS)

    Highlights: • Pin and assembly lift-off forces are compared between solid and annular fuel. • Annular fuel experiences much stronger uplift forces. • Much stronger hold-down forces are required by annular fuel assembly. • Engineering modifications for hold-down mechanisms are required by annular fuel. - Abstract: In the PWR core, the fuel assembly is firmly seated on the lower core plate during operation. However, if the hydraulic force exerted on the fuel assembly by coolant flow is too large and the fuel assembly is lifted-off from the lower core plate, the excessive vibration will cause fuel failure. Therefore, the hydraulic lift-off issue needs to be addressed when the advanced fuel assembly is developed. It has been shown that the advanced annular fuel design with internal cooling allows power uprating up to 50% while the peak temperature of the fuel can be reduced and the MDNBR can be maintained. However, if the coolant condition in the core is kept unchanged, increasing the core power by 50% requires the core flow rate also increase proportionally, which will give rise to the hydraulic lift-off, an important issue to be addressed. In this paper, taking the 17 × 17 solid fuel design as the reference, the hydraulic lift-off issue is investigated for proposed 12 × 12 and 13 × 13 annular fuel designs. Both the steady-state and start-up operating conditions are evaluated. It is found that the hydraulic lift-off indeed is an issue for annular fuel design which requires careful analysis. By comparison, the lift-off forces and hold-down forces required for the externally and internally cooled annular fuels (13 × 13 and 12 × 12 arrays) are several times larger than that of the referenced solid fuel (17 × 17 array). Therefore, the hold-down mechanism for annular fuel needs to be carefully designed

  19. Geography of irreducible plane sextics

    OpenAIRE

    Akyol, Ayşegül; Degtyarev, Alex

    2014-01-01

    We complete the equisingular deformation classification of irreducible singular plane sextic curves. As a by-product, we also compute the fundamental groups of the complement of all but a few maximizing sextics.

  20. On the Motion of an Annular Film in Microgravity Gas-Liquid Flow

    Science.gov (United States)

    McQuillen, John B.

    2002-01-01

    Three flow regimes have been identified for gas-liquid flow in a microgravity environment: Bubble, Slug, and Annular. For the slug and annular flow regimes, the behavior observed in vertical upflow in normal gravity is similar to microgravity flow with a thin, symmetrical annular film wetting the tube wall. However, the motion and behavior of this film is significantly different between the normal and low gravity cases. Specifically, the liquid film will slow and come to a stop during low frequency wave motion or slugging. In normal gravity vertical upflow, the film has been observed to slow, stop, and actually reverse direction until it meets the next slug or wave.

  1. Burnout in the boiling of water and freon-113 on tubes with annular fins

    International Nuclear Information System (INIS)

    This paper presents the results of numerical calculations of burnout heat flux associated with the boiling of Freon-113 and water on an annular fin of constant thickness which have been approximated by simple analytical relations. These are used to calculate the critical burnout parameters of tubes with an annular fin assembly. The calculated data may be used for the analysis of tubes with an annular fin assembly over a wide range of variation of the thermophysical properties of the material and geometrical parameters of the fin assembly

  2. Interarm differences in systolic blood pressure and mortality among US army veterans

    DEFF Research Database (Denmark)

    White, James; Mortensen, Laust Hvas; Kivimäki, Mika;

    2014-01-01

    BACKGROUND: Differences between the arms in systolic blood pressure (SBP) of ≥10 mmHg have been associated with an increased risk of mortality in patients with hypertensive and chronic renal disease. For the first time, we examined these relationships in a non-clinical population. DESIGN: Cohort...

  3. Effects of reversible ischemia on systolic left ventricular function evaluated by rest/stress gated SPECT

    International Nuclear Information System (INIS)

    Amplitude of post-stress systolic left ventricular dysfunction is characterized by increasing of end-systolic volume (ESV) and decreasing of ejection fraction (EF) and can be measured by 99mTc-MIBI gated SPECT. Is the dysfunction degree depended on the ischemia size and depth? We studied 11 normal subjects (control group) and 31 subjects with documented coronary artery disease at rest and after mixed stress test: dipyridamole (0,7 mg/kg) and exercise without workload limit. Post-stress systolic dysfunction was observed in almost all of patients with reversible ischemia (ESV increased in 84% and EF decreased in 92% of them). On the other hand, in patients without reversible ischemia, ESV decreased or changed not significantly and EF increased or changed not significantly. Furthermore, in patients with reversible ischemia, when compared to perfusion and thickening scores, we found a positive correlation for ESV variations and a negative one for EF variations. The chance to detect a post-stress systolic dysfunction is high in case of reversible ischemia, if the stress is intense enough. Thus the phenomenon must be surveyed in routine nuclear cardiology practice. (author)

  4. Decreasing systolic blood pressure and declining mortality rates in an untreated population

    DEFF Research Database (Denmark)

    Andersen, Ulla O; Marott, Jacob L; Jensen, Gorm B

    2011-01-01

    The aim of the present study was to evaluate developments in 30 years mortality risk that may be associated with developments in population systolic blood pressure (SBP) and to evaluate possible secular trends in BP-associated mortality risk in the untreated population....

  5. Systolically gated 3D phase contrast MRA of mesenteric arteries in suspected mesenteric ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Wasser, M.N.; Schultze Kool, L.J.; Roos, A. de [Leiden Univ. Hospital (Netherlands)] [and others

    1996-03-01

    Our goal was to assess the value of MRA for detecting stenoses in the celiac (CA) and superior mesenteric (SMA) arteries in patients suspected of having chronic mesenteric ischemia, using an optimized systolically gated 3D phase contrast technique. In an initial study in 24 patients who underwent conventional angiography of the abdominal vessels for different clinical indications, a 3D phase contrast MRA technique (3D-PCA) was evaluated and optimized to image the CAs and SMAs. Subsequently, a prospective study was performed to assess the value of systolically gated 3D-PCA in evaluation of the mesenteric arteries in 10 patients with signs and symptoms of chronic mesenteric ischemia. Intraarterial digital subtraction angiography and surgical findings were used as the reference standard. In the initial study, systolic gating appeared to be essential in imaging the SMA on 3D-PCA. In 10 patients suspected of mesenteric ischemia, systolically gated 3D-PCA identified significant proximal disease in the two mesenteric vessels in 4 patients. These patients underwent successful reconstruction of their stenotic vessels. Cardiac-gated MRA may become a useful tool in selection of patients suspected of having mesenteric ischemia who may benefit from surgery. 16 refs., 6 figs., 4 tabs.

  6. Microalbuminuria in patients with non-insulin-dependent diabetes mellitus relates to nocturnal systolic blood pressure.

    LENUS (Irish Health Repository)

    Mitchell, T H

    2012-02-03

    PURPOSE: Microalbuminuria predicts early mortality in non-insulin-dependent-diabetes mellitus patients (NIDDM). Our objective in the present study was to compare and assess the relationship between 24-hour, day and nocturnal ambulatory blood pressure (BP) and urinary albumin excretion rate (UAE) in microalbuminuric and normoalbuminuric NIDDM and in normal control subjects. PATIENTS AND METHODS: In the present cross-sectional study, 24 hour ambulatory BP (daytime BP and nocturnal BP) and HbA1c were compared in microalbuminuric (n = 10) and nonmicroalbuminuric NIDDM patients (n = 10) and in nondiabetic controls (n = 9). None of the patients were taking antihypertensive agents. RESULTS: In the microlbuminuric group, whereas 24 hour and daytime systolic BP differed significantly from control values (P < 0.025 and P < 0.05 respectively), there was no difference between diabetic groups. However, nocturnal systolic BP in the microalbuminuric group was significantly higher than in the normoalbuminuric diabetic patients (139 vs. 125) (P < 0.05) and a significant difference was also found between the NIDDM patients and the control group (139, 125 vs. 114) (P < 0.025). In multiple regression analysis, only nocturnal systolic BP showed a significant relationship with UAE (P < 0.05). CONCLUSIONS: We suggest that the higher nocturnal systolic blood pressure seen in our microalbuminuric NIDDM patients may contribute to the increased morbidity in this group.

  7. Decreased mitochondrial oxidative phosphorylation capacity in the human heart with left ventricular systolic dysfunction

    DEFF Research Database (Denmark)

    Stride, Nis; Larsen, Steen; Hey-Mogensen, Martin; Sander, Kåre; Lund, Jens T; Gustafsson, Finn; Køber, Lars; Dela, Flemming

    2013-01-01

    Heart failure (HF) with left ventricular systolic dysfunction (LVSD) is associated with a shift in substrate utilization and a compromised energetic state. Whether these changes are connected with mitochondrial dysfunction is not known. We hypothesized that the cardiac phenotype in LVSD could be...

  8. Systolic left ventricular function according to left ventricular concentricity and dilatation in hypertensive patients

    DEFF Research Database (Denmark)

    Bang, Casper; Gerdts, Eva; Aurigemma, Gerard P;

    2013-01-01

    Left ventricular hypertrophy [LVH, high left ventricular mass (LVM)] is traditionally classified as concentric or eccentric based on left ventricular relative wall thickness. We evaluated left ventricular systolic function in a new four-group LVH classification based on left ventricular dilatatio...

  9. Current Evidence on Treatment of Patients With Chronic Systolic Heart Failure and Renal Insufficiency

    NARCIS (Netherlands)

    Damman, Kevin; Tang, W. H. Wilson; Felker, G. Michael; Lassus, Johan; Zannad, Faiez; Krum, Henry; McMurray, John J. V.

    2014-01-01

    Chronic kidney disease (CKD) is increasingly prevalent in patients with chronic systolic heart failure. Therefore, evidence-based therapies are more and more being used in patients with some degree of renal dysfunction. However, most pivotal randomized clinical trials specifically excluded patients

  10. The measurement of digital systolic blood pressure by strain gauge technique

    DEFF Research Database (Denmark)

    Nielsen, P E; Bell, G; Lassen, N A

    1972-01-01

    The systolic blood pressure on the finger, toe, and ankle has been measured by a strain gauge technique in 10 normal subjects aged 17-31 years and 14 normal subjects aged 43-57 years. The standard deviation in repeated measurements lies between 2 and 6 mm Hg. The finger pressure in the younger...

  11. Influence of renal impairment on myocardial function in outpatients with systolic heart failure

    DEFF Research Database (Denmark)

    Bosselmann, Helle; Tønder, Niels; Sölétormos, György;

    2014-01-01

    BACKGROUND: Renal dysfunction (RD) is associated with poor outcome in systolic heart failure (HF). Left ventricular ejection fraction (LVEF) is not depressed to a greater extent in patients with RD compared to patients with normal renal function, but it is relatively unknown whether other measures...

  12. Isolated systolic hypertension in an elderly Danish population. Prevalence and daytime ambulatory blood pressure

    DEFF Research Database (Denmark)

    Talleruphuus, Ulrik; Bang, Lia Evi; Wiinberg, Niels;

    2006-01-01

    Isolated systolic hypertension (ISH) is a major risk factor for cardiovascular complications. Nevertheless, data on the prevalence in a representative population do not seem to be available. The prevalence of ISH and the white coat effect was thus studied in a cross-sectional survey of 2806...

  13. Systolic arrays for binary image processing by using Boolean differential operators

    Science.gov (United States)

    Shmerko, V. P.; Yanushkevich, S. N.; Kochergov, E. G.

    1993-11-01

    A matrix form of the Boolean differential temporal (parametric) operators is proposed. The procedures of preliminary binary image processing (logic filtering, finding of contours) are constructed on this base. This presentation of the operators allows to synthesize the algorithms having a mapping into an architecture of systolic arrays.

  14. Linkage analysis of systolic blood pressure: a score statistic and computer implementation

    OpenAIRE

    Peng Yingwei; Wang Kai

    2003-01-01

    Abstract A genome-wide linkage analysis was conducted on systolic blood pressure using a score statistic. The randomly selected Replicate 34 of the simulated data was used. The score statistic was applied to the sibships derived from the general pedigrees. An add-on R program to GENEHUNTER was developed for this analysis and is freely available.

  15. Significance of white-coat hypertension in older persons with isolated systolic hypertension

    DEFF Research Database (Denmark)

    Franklin, Stanley S; Thijs, Lutgarde; Hansen, Tine W;

    2012-01-01

    The significance of white-coat hypertension in older persons with isolated systolic hypertension remains poorly understood. We analyzed subjects from the population-based 11-country International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes database who...

  16. Adding serial N-terminal pro brain natriuretic peptide measurements to optimal clinical management in outpatients with systolic heart failure

    DEFF Research Database (Denmark)

    Schou, Morten; Gustafsson, Finn; Videbaek, Lars;

    2013-01-01

    AIMS: This study was designed to evaluate a new NT-proBNP monitoring concept in outpatients with systolic heart failure (HF). METHODS AND RESULTS: This was a multicentre, prospective randomized open-label blinded endpoint study. A total of 407 systolic HF patients were allocated to either clinica...

  17. Right ventricular dysfunction as an independent predictor of short- and long-term mortality in patients with heart failure

    DEFF Research Database (Denmark)

    Kjaergaard, Jesper; Akkan, Dilek; Iversen, Kasper Karmark;

    2007-01-01

    BACKGROUND: The prognostic importance of right ventricular (RV) dysfunction in heart failure (HF) has been suggested in patients with severe systolic heart failure. Tricuspid annular plane systolic excursion (TAPSE) is a simple echocardiographic measure of RV ejection fraction, but may be affected...

  18. Method of improving image sharpness for annular-illumination scanning electron microscopes

    Science.gov (United States)

    Enyama, Momoyo; Hamada, Koichi; Fukuda, Muneyuki; Kazumi, Hideyuki

    2016-06-01

    Annular illumination is effective in enhancing the depth of focus for scanning electron microscopes (SEMs). However, owing to high side lobes of the point-spread function (PSF), annular illumination results in poor image sharpness. The conventional deconvolution method, which converts the PSF to a delta function, can improve image sharpness, but results in artifacts due to noise amplification. In this paper, we propose an image processing method that can reduce the deterioration of image sharpness. With this method, the PSF under annular illumination is converted to that under standard illumination. Through simulations, we verified that the image sharpness of SEM images under annular illumination with the proposed method can be improved without noise amplification.

  19. Ultra-Wide-Band Microstrip Concentric Annular Ring Antenna for Wireless Communications

    Directory of Open Access Journals (Sweden)

    Salima Azzaz-Rahmani

    2012-01-01

    Full Text Available In this paper, a new design technique for bandwidth enhancement of concentric microstrip annular ring slot antennas is presented. Using this technique, an Ultra-Wide-Band antenna is designed with simulated bandwidth of 111.29%.

  20. The analysis of the annular fuel performance in steady state condition by using AFPAC code

    International Nuclear Information System (INIS)

    The fuel performance code AFPAC v1.0 is used to analyze annular fuel's behavior under steady state conditions, including neutronics, thermal hydraulic, rod deformation, fission gas release and rod internal pressure. The calculation results show that: 1) Annular fuel has a good steady irradiation performance at 150% power level as current LWRs' with burnup up to 50 GWd/t, and all parameters, such as temperature, rod internal pressure and rod deformation, are meet the rod design criteria for current fuel of PWRs: 2) Compared to the solid fuel under the same irradiation condition. annular fuel has lower temperature, smaller deformation, lower fission gas release and lower pressure at EOL. From the point of view of steady irradiation performance, the safety of reactors can significantly improved by u sing the annular fuel. (authors)

  1. Effect of January 15, 2010 annular solar eclipse on meteorological parameters over Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; Nisha, P.G.; Mohankumar, K.

    Atmospheric perturbations due to the annular solar eclipse were monitored to understand its influence on the meteorological parameters from surface to the lower stratosphere. A strong inversion at 13 km and an abnormal warming in the upper...

  2. Biofilm Community Dynamics in Bench-Scale Annular Reactors Simulating Arrestment of Chloraminated Drinking Water Nitrification

    Science.gov (United States)

    Annular reactors (ARs) were used to study biofilm community succession and provide an ecological insight during nitrification arrestment through simultaneously increasing monochloramine (NH2Cl) and chlorine to nitrogen mass ratios, resulting in four operational periods (I to IV)....

  3. An iterative method for the solution of nonlinear systems using the Faber polynomials for annular sectors

    Energy Technology Data Exchange (ETDEWEB)

    Myers, N.J. [Univ. of Durham (United Kingdom)

    1994-12-31

    The author gives a hybrid method for the iterative solution of linear systems of equations Ax = b, where the matrix (A) is nonsingular, sparse and nonsymmetric. As in a method developed by Starke and Varga the method begins with a number of steps of the Arnoldi method to produce some information on the location of the spectrum of A. This method then switches to an iterative method based on the Faber polynomials for an annular sector placed around these eigenvalue estimates. The Faber polynomials for an annular sector are used because, firstly an annular sector can easily be placed around any eigenvalue estimates bounded away from zero, and secondly the Faber polynomials are known analytically for an annular sector. Finally the author gives three numerical examples, two of which allow comparison with Starke and Varga`s results. The third is an example of a matrix for which many iterative methods would fall, but this method converges.

  4. Boiling two-phase flow and heat transfer in concentric annular tube

    International Nuclear Information System (INIS)

    The boiling flow resistance and heat transfer characteristics is experimentally investigated under the outer tube wall heating condition in a concentric annular tube with 2.1 mm gap size. The results show that the flow resistance in the annular tube is greater than that in circular tube, as well as the boiling heat transfer becomes enhanced. The heat transfer coefficient has close relationship with the pressure, thermal equilibrium quality, mass flux, heat flux, gap size of the annular tube, and heat models as well. The physical explanation about the enhancement boiling heat transfer in the annular tube is proposed with both micro-film evaporation mechanics and bubble disturbance mechanics. The correlations to calculate the flow friction coefficient and heat transfer coefficient are proposed based on the experimental data. (authors)

  5. An X-band high-impedance relativistic klystron amplifier with an annular explosive cathode

    International Nuclear Information System (INIS)

    The feasibility of employing an annular beam instead of a solid one in the X-band high-impedance relativistic klystron amplifier (RKA) is investigated in theory and simulation. Small-signal theory analysis indicates that the optimum bunching distance, fundamental current modulation depth, beam-coupling coefficient, and beam-loaded quality factor of annular beams are all larger than the corresponding parameters of solid beams at the same beam voltage and current. An annular beam RKA and a solid beam RKA with almost the same geometric parameters are compared in particle-in-cell simulation. Output microwave power of 100 MW, gain of 50 dB, and power conversion efficiency of 42% are obtained in an annular beam RKA. The annular beam needs a 15% lower uniform guiding magnetic field than the solid beam. Our investigations demonstrate that we are able to use a simple annular explosive cathode immersed in a lower uniform magnetic field instead of a solid thermionic cathode in a complicated partially shielding magnetic field for designing high-impedance RKA, which avoids high temperature requirement, complicated electron-optical system, large area convergence, high current density, and emission uniformity for the solid beam. An equivalent method for the annular beam and the solid beam on bunching features is proposed and agrees with the simulation. The annular beam has the primary advantages over the solid beam that it can employ the immersing uniform magnetic field avoiding the complicated shielding magnetic field system and needs a lower optimum guiding field due to the smaller space charge effect

  6. Recent achievements on annular Josephson structures and their application as radiation detectors

    International Nuclear Information System (INIS)

    One of the stimulating area of superconductors investigations lies in the achieved and potential applications as radiation detectors. Results concerning annular Josephson junctions in this context are discussed. Fundamental aspects, mainly related to the fluxon dynamics in such structures, are discussed in detail. The results confirm the importance of the precious sharing of technological requests with fundamental physical implications. Peculiar results are reported dealing with new resonances occurring on these Josephson junctions of annular configuration

  7. Fabrication of Annular Pellet for HANARO Irradiation Test of Dual Cooled Fuel

    International Nuclear Information System (INIS)

    One of the most important components in a Pressurized Water Reactor affecting its safety and economy is a nuclear fuel. The traditional PWR fuel pellet has a shape of cylindrical tablets of about 8 mm in diameter with a chamfer and dishes. A significant reduction in its failure rate has resulted from the improvements in the fuel and cladding quality. Enhanced fuel assembly design allowed appreciable power density increases. However, it is difficult to achieve a significant increase of a power density under the current fuel pin design. An internally and externally cooled annular fuel has been considered seriously as a promising solution for an extended power uprate of a PWR fuel assembly. A dual cooled annular fuel shows a lot of advantages from the point of a fuel safety and its economy due to its unique configurational merit such as an increased heat transfer area and a thin pellet thickness. There must be a lot of considerations in the various fields to introduce an annular internally and externally cooled fuel to commercial PWR reactors. The dimensional changes of the annular fuel pellets during the early irradiation stage are very important, because they have an influence on the size of the gap between the pellet and the inner/outer claddings. In order to gain an insight to how the annular pellets deform, a HANARO irradiation test is planned for annular pellets with 5 different types. The detailed specification of the annular pellet was shown in Table 1. It is noted that Type C has the same pore structure as a commercial PWR pellet. The purpose of this paper is to report on the manufacturing process of an annular fuel pellet for a HANARO irradiation test

  8. Large Eddy Simulation of ignition in an annular multi-injector combustor

    Science.gov (United States)

    Vicquelin, Ronan; Philip, Maxime; Boileau, Matthieu; Schmitt, Thomas; Bourgoin, Jean-François; Durox, Daniel; Candel, Sébastien

    2013-11-01

    The present work deals with validating the LES methodology for transient ignition simulations, and in particular elucidating the mechanisms that control the light round sequence in a laboratory annular combustor, representative of many practical industrial systems. The simulation benefits from the unique experimental database built at EM2C on a fully transparent annular chamber equipped with 16 premixed swirled injectors. The F-TACLES combustion model is used for its ability to properly represent the flame propagation.

  9. A simple analytical model to study and control azimuthal instabilities in annular combustion chambers

    OpenAIRE

    Parmentier, Jean-François; Salas, Pablo; Wolf, Pierre; Staffelbach, Gabriel; Nicoud, Franck; Poinsot, Thierry

    2012-01-01

    This study describes a simple analytical method to compute the azimuthal modes appearing in annular combustion chambers and help analyzing experimental, acoustic and large eddy simulation (LES) data obtained in these combustion chambers. It is based on a one-dimensional zero Mach number formulation where N burners are connected to a single annular chamber. A manipulation of the corresponding acoustic equations in this configuration leads to a simple dispersion relation which can be solved by ...

  10. The numerical solution of flow field of short-annular combustion chamber

    Science.gov (United States)

    Xu, H.; Ning, H.

    1986-05-01

    The recirculating flow field of a short-annular combustion chamber has been studied. The body-fitting coordinate system and the 'simple' method combined with a constant viscosity model have been employed to solve the Navier-Stokes equations in a regime containing a complicated curved boundary. The result could provide the theoretical reference for the design and improvement of short-annular combustion chambers.

  11. The influence of the equivalent hydraulic diameter on the pressure drop prediction of annular test section

    Science.gov (United States)

    Al-Kayiem, A. H. H.; Ibrahim, M. A.

    2015-12-01

    The flow behaviour and the pressure drop throughout an annular flow test section was investigated in order to evaluate and justify the reliability of experimental flow loop for wax deposition studies. The specific objective of the present paper is to assess and highlight the influence of the equivalent diameter method on the analysis of the hydrodynamic behaviour of the flow and the pressure drop throughout the annular test section. The test section has annular shape of 3 m length with three flow passages, namely; outer thermal control jacket, oil annular flow and inner pipe flow of a coolant. The oil annular flow has internal and external diameters of 0.0422 m and 0.0801 m, respectively. Oil was re-circulated in the annular passage while a cold water-glycol mixture was re-circulated in the inner pipe counter currently to the oil flow. The experiments were carried out at oil Reynolds number range of 2000 to 17000, covering laminar, transition and turbulent flow regimes. Four different methods of equivalent diameter of the annulus have been considered in this hydraulic analysis. The correction factor model for frictional pressure drop was also considered in the investigations. All methods addressed the high deviation of the prediction from the experimental data, which justified the need of a suitable pressure prediction correlation for the annular test section. The conventional hydraulic diameter method is a convenient substitute for characterizing physical dimension of a non-circular duct, and it leads to fairly good correlation between turbulent fluid flow and heat transfer characteristic of annular ducts.

  12. An X-band high-impedance relativistic klystron amplifier with an annular explosive cathode

    Science.gov (United States)

    Zhu, Danni; Zhang, Jun; Zhong, Huihuang; Qi, Zumin

    2015-11-01

    The feasibility of employing an annular beam instead of a solid one in the X-band high-impedance relativistic klystron amplifier (RKA) is investigated in theory and simulation. Small-signal theory analysis indicates that the optimum bunching distance, fundamental current modulation depth, beam-coupling coefficient, and beam-loaded quality factor of annular beams are all larger than the corresponding parameters of solid beams at the same beam voltage and current. An annular beam RKA and a solid beam RKA with almost the same geometric parameters are compared in particle-in-cell simulation. Output microwave power of 100 MW, gain of 50 dB, and power conversion efficiency of 42% are obtained in an annular beam RKA. The annular beam needs a 15% lower uniform guiding magnetic field than the solid beam. Our investigations demonstrate that we are able to use a simple annular explosive cathode immersed in a lower uniform magnetic field instead of a solid thermionic cathode in a complicated partially shielding magnetic field for designing high-impedance RKA, which avoids high temperature requirement, complicated electron-optical system, large area convergence, high current density, and emission uniformity for the solid beam. An equivalent method for the annular beam and the solid beam on bunching features is proposed and agrees with the simulation. The annular beam has the primary advantages over the solid beam that it can employ the immersing uniform magnetic field avoiding the complicated shielding magnetic field system and needs a lower optimum guiding field due to the smaller space charge effect.

  13. A research on the mechanisms of transition from annular flow in two-phase pipeline flow

    International Nuclear Information System (INIS)

    Various kinds mechanisms of transitions from two-phase annular flow in tubes were studied and modelled, and the affection factors on the transitions were also discussed. Some mathematical equations and transition criteria for every mechanisms presented were derived, and an unified general criterion for the annular flow transitions in whole range of pipe inclinations was recommended. The boundaries predicted show good agreement with the air-water two-phase experimental data

  14. Asymmetric Vibration of Polar Orthotropic Annular Circular Plates of Quadratically Varying Thickness with Same Boundary Conditions

    OpenAIRE

    Bhardwaj, N; Gupta, A. P.; Choong, K.K.

    2008-01-01

    In the present paper, asymmetric vibration of polar orthotropic annular circular plates of quadratically varying thickness resting on Winkler elastic foundation is studied by using boundary characteristic orthonormal polynomials in Rayleigh-Ritz method. Convergence of the results is tested and comparison is made with results already available in the existing literature. Numerical results for the first ten frequencies for various values of parameters describing width of annular plate, thicknes...

  15. Modified Surgical Intervention for Extensive Mitral Valve Endocarditis and Posterior Mitral Annular Calcification

    Science.gov (United States)

    Kim, Gwan Sic; Beom, Min Sun; Kim, Sung Ryong; Kim, Na Rae; Jang, Ji Wook; Jang, Mi Hee; Ryu, Sang Wan

    2016-01-01

    The concomitant presence of posterior mitral annular calcification and infectious mitral valve lesions poses a technical challenge with considerable perioperative risk when using previously proposed techniques for mitral valve surgery. Herein, we report a case of the use of a modified surgical technique to successfully treat a patient with mitral infective endocarditis complicated by a subendocardial abscess and extensive posterior mitral annular calcification. PMID:26889447

  16. Design and characterization of the annular cathode high current pulsed electron beam source for circular components

    Science.gov (United States)

    Jiang, Wei; Wang, Langping; Wang, Xiaofeng

    2016-08-01

    In order to irradiate circular components with high current pulsed electron beam (HCPEB), an annular cathode based on carbon fiber bunches was designed and fabricated. Using an acceleration voltage of 25 kV, the maximum pulsed irradiation current and energy of this annular cathode can reach 7.9 kA and 300 J, respectively. The irradiation current density distribution of the annular cathode HCPEB source measured along the circumferential direction shows that the annular cathode has good emission uniformity. In addition, four 9310 steel substrates fixed uniformly along the circumferential direction of a metal ring substrate were irradiated by this annular cathode HCPEB source. The surface and cross-section morphologies of the irradiated samples were characterized by scanning electron microscopy (SEM). SEM images of the surface reveal that crater and surface undulation have been formed, which hints that the irradiation energy of the HCPEB process is large enough for surface modification of 9310 steel. Meanwhile, SEM cross-section images exhibit that remelted layers with a thickness of about 5.4 μm have been obtained in all samples, which proves that a good practical irradiation uniformity can be achieved by this annular cathode HCPEB source.

  17. Monthly rifampicin, ofloxacin, and minocycline therapy for generalized and localized granuloma annulare

    Directory of Open Access Journals (Sweden)

    Shilpa Garg

    2015-01-01

    Full Text Available Background: The localized form of granuloma annulare is usually self-limiting, resolving within 2 years. Generalized granuloma annulare, on the other hand, runs a protracted course, with spontaneous resolution being rare. It is also characterized by a later age of onset, an increased incidence of diabetes mellitus, poor response to therapy, and an increased prevalence of HLA Bw35. Objective: To assess the efficacy of monthly pulsed rifampicin, ofloxacin, and minocycline (ROM therapy in the management of granuloma annulare. Methods : Six biopsy proven patients of granuloma annulare were included in the study, five of the generalized variety, and one localized. Three of these patients were resistant to standard modalities of treatment. All six patients were treated with pulses of once monthly ROM till complete resolution of all lesions. Results were analyzed in terms of complete resolution of lesions and side effects. Presence of comorbid conditions was noted. Result: All six patients were successfully treated with 4-8 pulses of monthly ROM. None of the patients reported any adverse effects. Limitations: Small sample size and the lack of a control group are limitations. Conclusion: Treatment with pulses of once monthly ROM caused complete resolution of lesions in both localized and generalized granuloma annulare, even in cases recalcitrant to conventional therapy. There were no side effects in any of the patients. Larger trials are needed to substantiate the efficacy of monthly ROM in granuloma annulare.

  18. Suppression of space-charge effects in transport through an RFQ using an annular beam

    International Nuclear Information System (INIS)

    High intensity proton linacs (HIPLs) have severe space-charge issues that can lead to emittance blow-up and the production of beam halos, both of which lead to limitations in the operable beam current. Hollow or annular beams are known to have a small spacecharge force (for a given current). Here we present preliminary studies on the production of such annular beams in the Low Energy Beam Transport (LEBT) line, and the subsequent transport of such a beam through a Radio- Frequency Quadrupole (RFQ). We show, using three-dimensional particle-in-cell simulations, that such an annular beam experiences a smaller emittance blow-up as well as reduced beam halo. Starting with an nns normalized emittance of 0.2 πmn-mrad, after transport through the RFQ the emittance blows up to 0.39 πmm-mrad for a Gaussian beam, but only to 0.26 πmm-mrad for an annular beam. Similarly, the halo parameter for the annular beam is only 0.4 as compared to 1.4 for the Gaussian beam. Thus, annular beams suffer lesser deterioration due to space-charge forces in transport through the RFQ, and may therefore be a better choice for HIPLs. (author)

  19. Fluid-Structure Interaction Analysis on Turbulent Annular Seals of Centrifugal Pumps during Transient Process

    Directory of Open Access Journals (Sweden)

    Qinglei Jiang

    2011-01-01

    Full Text Available The current paper studies the influence of annular seal flow on the transient response of centrifugal pump rotors during the start-up period. A single rotor system and three states of annular seal flow were modeled. These models were solved using numerical integration and finite difference methods. A fluid-structure interaction method was developed. In each time step one of the three annular seal models was chosen to simulate the annular seal flow according to the state of rotor systems. The objective was to obtain a transient response of rotor systems under the influence of fluid-induced forces generated by annular seal flow. This method overcomes some shortcomings of the traditional FSI method by improving the data transfer process between two domains. Calculated results were in good agreement with the experimental results. The annular seal was shown to have a supportive effect on rotor systems. Furthermore, decreasing the seal clearance would enhance this supportive effect. In the transient process, vibration amplitude and critical speed largely changed when the acceleration of the rotor system increased.

  20. An optical system design that converts a Gaussian to a flattop annular beam

    Science.gov (United States)

    Li, Chaochen; Wu, Tengfei; Wang, Yu

    2015-10-01

    Flattop annular beam has been predicted with good character over an increasing application, but the generating of flattop annular beam is rarely mentioned by academic article. In our paper, an optical refractive system, which is designed to achieve flattop annular beam, are proposed. The cone prism is commonly used to get an annular beam, however, the beam intensity distribution is non-uniform. In our design, an additional aspheric lens is placed in front of the cone prism along the optical axis. The lens parameters are theoretically analyzed and well optimized to homogenize the optical field. Furthermore, to lower the requirement of machining accuracy, a pair of aspheric lenses is also designed, which can be used independently to generate flattop annular beam. It combines the function of cone prism and aspheric lens, so as to replace them both. The performance of the implementations has been demonstrated in detail. Simulation result shows that the proposed design is effective and feasible. It is hope that our work would be helpful in related fields. Flattop annular beam, Aspheric lens, Cone prism

  1. Characterization of Novel Calorimeters in the Annular Core Research Reactor *

    Directory of Open Access Journals (Sweden)

    Hehr Brian D.

    2016-01-01

    Full Text Available A series of pulsed irradiation experiments have been performed in the central cavity of Sandia National Laboratories' Annular Core Research Reactor (ACRR to characterize the responses of a set of elemental calorimeter materials including Si, Zr, Sn, Ta, W, and Bi. Of particular interest was the perturbing effect of the calorimeter itself on the ambient radiation field – a potential concern in dosimetry applications. By placing the calorimeter package into a neutron-thermalizing lead/polyethylene (LP bucket and irradiating both with and without a cadmium wrapper, it was demonstrated that prompt capture gammas generated inside the calorimeters can be a significant contributor to the measured dose in the active disc region. An MCNP model of the experimental setup was shown to replicate measured dose responses to within 10%. The internal (n,γ contribution was found to constitute as much as 50% of the response inside the LP bucket and up to 20% inside the nominal (unmodified cavity environment, with Ta and W exhibiting the largest enhancement due to their sizable (n,γ cross sections. Capture reactions in non-disc components of the calorimeter were estimated to be responsible for up to a few percent of the measured response.

  2. Computation of Flow through an Annular Diffuser and Volute Exhaust

    Directory of Open Access Journals (Sweden)

    M. Arun

    2006-04-01

    Full Text Available Turbulent flow in a diffuser with swirl occurs in many commonly used fluid mechanicaldevices,eg, diffusers located downstream of a gas turbine, and in certain types of combustionchambers. Diffusers are widely used for converting kinetic energy to pressure, and a reliableprediction method of such flows with the required flow conditions would lead to the design offluid machinery with improved efficiency. As a first step, turbulent swirling flow through a 12oincluded angle conical diffuser for a swirl parameter, m = 0.18 was numerically investigated usingvarious turbulence models like standard k- , RNG-based k- , shear-stress transport (SST kandReynolds stress model (RSM. Though the comparison between the experimental and thepredicted mean velocity profile by RSM is superior to that by RNG kandSST models, the lattertwo models give closer comparison with the experimental pressure distribution. Subsequently,computation of flow inside a complex duct involving axisymmetric annular diffuser, transitionfrom rectangular to circular cross section, and exit pipe have been carried out using RNG kandSST k models.The comparison of computed and experimental results indicates that theSST k modelgives predictions with reasonable accuracy.

  3. Characterization of Novel Calorimeters in the Annular Core Research Reactor

    Science.gov (United States)

    Hehr, Brian D.; Parma, Edward J.; Peters, Curtis D.; Naranjo, Gerald E.; Luker, S. Michael

    2016-02-01

    A series of pulsed irradiation experiments have been performed in the central cavity of Sandia National Laboratories' Annular Core Research Reactor (ACRR) to characterize the responses of a set of elemental calorimeter materials including Si, Zr, Sn, Ta, W, and Bi. Of particular interest was the perturbing effect of the calorimeter itself on the ambient radiation field - a potential concern in dosimetry applications. By placing the calorimeter package into a neutron-thermalizing lead/polyethylene (LP) bucket and irradiating both with and without a cadmium wrapper, it was demonstrated that prompt capture gammas generated inside the calorimeters can be a significant contributor to the measured dose in the active disc region. An MCNP model of the experimental setup was shown to replicate measured dose responses to within 10%. The internal (n,γ) contribution was found to constitute as much as 50% of the response inside the LP bucket and up to 20% inside the nominal (unmodified) cavity environment, with Ta and W exhibiting the largest enhancement due to their sizable (n,γ) cross sections. Capture reactions in non-disc components of the calorimeter were estimated to be responsible for up to a few percent of the measured response. This work was supported by the United States Department of Energy under Contract DE-AC04-94AL85000. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy.

  4. DCH dispersal and entrainment experiment in a scaled annular cavity

    International Nuclear Information System (INIS)

    The objective of this experiment was to measure the amount of corium dispersal and the droplet size distribution during high pressure melt ejection from a CE reactor. The melt and the steam flowed to the containment through a narrow annular cavity. The experiment was carried out on a 1/20th scaled model of the cavity and the containment. The scaling was based on dimensionless numbers obtained from a two-phase flow model of the dispersal and entrainment mechanisms in the cavity. Furthermore, the model shows that the flow in the cavity was choked, so high levels of dispersal and entrainment were possible. The experiment consisted of air-water, air-helium, air-woods metal and helium-woods metal tests; the main result being that the level of dispersal was very high in all cases. The woods metal data supported a separated flow model in the cavity, implying that the gas choked velocity was very high and the droplets very small. In contrast, the measured drop sizes for the water tests were much larger than the separated flow model predictions. This discrepancy could not be resolved because the entrainment mechanism is not properly understood at the present time. (orig.)

  5. Current Density Measurements of an Annular-Geometry Ion Engine

    Science.gov (United States)

    Shastry, Rohit; Patterson, Michael J.; Herman, Daniel A.; Foster, John E.

    2012-01-01

    The concept of the annular-geometry ion engine, or AGI-Engine, has been shown to have many potential benefits when scaling electric propulsion technologies to higher power. However, the necessary asymmetric location of the discharge cathode away from thruster centerline could potentially lead to non-uniformities in the discharge not present in conventional geometry ion thrusters. In an effort to characterize the degree of this potential non-uniformity, a number of current density measurements were taken on a breadboard AGI-Engine. Fourteen button probes were used to measure the ion current density of the discharge along a perforated electrode that replaced the ion optics during conditions of simulated beam extraction. Three Faraday probes spaced apart in the vertical direction were also used in a separate test to interrogate the plume of the AGI-Engine during true beam extraction. It was determined that both the discharge and the plume of the AGI-Engine are highly uniform, with variations under most conditions limited to +/-10% of the average current density in the discharge and +/-5% of the average current density in the plume. Beam flatness parameter measured 30 mm from the ion optics ranged from 0.85 - 0.95, and overall uniformity was shown to generally increase with increasing discharge and beam currents. These measurements indicate that the plasma is highly uniform despite the asymmetric location of the discharge cathode.

  6. Criticality Benchmark Analysis of the HTTR Annular Startup Core Configurations

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess

    2009-11-01

    One of the high priority benchmarking activities for corroborating the Next Generation Nuclear Plant (NGNP) Project and Very High Temperature Reactor (VHTR) Program is evaluation of Japan's existing High Temperature Engineering Test Reactor (HTTR). The HTTR is a 30 MWt engineering test reactor utilizing graphite moderation, helium coolant, and prismatic TRISO fuel. A large amount of critical reactor physics data is available for validation efforts of High Temperature Gas-cooled Reactors (HTGRs). Previous international reactor physics benchmarking activities provided a collation of mixed results that inaccurately predicted actual experimental performance.1 Reevaluations were performed by the Japanese to reduce the discrepancy between actual and computationally-determined critical configurations.2-3 Current efforts at the Idaho National Laboratory (INL) involve development of reactor physics benchmark models in conjunction with the International Reactor Physics Experiment Evaluation Project (IRPhEP) for use with verification and validation methods in the VHTR Program. Annular cores demonstrate inherent safety characteristics that are of interest in developing future HTGRs.

  7. Experimental investigation of the low NOx vortex airblast annular combustor

    Science.gov (United States)

    Johnson, S. M.; Biaglow, J. A.; Smith, J. M.

    1984-01-01

    A low oxides of nitrogen vortex airblast annular combustor was evaluated which has attained the goal of 1 gm NO2/kg fuel or less during operation. The experimental combustor test conditions were a nominal inlet-air temperature of 703 K, inlet total pressures between 0.52 to 0.83 MPa, and a constant inlet Mach number of 0.26. Exit temperature pattern factors for all test points were between 0.16 and 0.20 and exit swirl flow angles were 47 degrees at isothermal conditions and 23 degrees during combustion. Oxides of nitrogen did not exceed 1.05 gm NO2/kg fuel at the highest inlet pressure and exhaust temperature tested. Previous correlations have related NOx proportionally to the combustor inlet pressure raised to some exponent. In this experiment, a band of exponents between 0.5 and 1.0 resulted for fuel-air ratios from 0.023 to 0.027 and inlet pressures from 0.52 to 0.83 MPa. Previously announced in STAR as N84-22567

  8. Criticality Benchmark Analysis of the HTTR Annular Startup Core Configurations

    International Nuclear Information System (INIS)

    One of the high priority benchmarking activities for corroborating the Next Generation Nuclear Plant (NGNP) Project and Very High Temperature Reactor (VHTR) Program is evaluation of Japan's existing High Temperature Engineering Test Reactor (HTTR). The HTTR is a 30 MWt engineering test reactor utilizing graphite moderation, helium coolant, and prismatic TRISO fuel. A large amount of critical reactor physics data is available for validation efforts of High Temperature Gas-cooled Reactors (HTGRs). Previous international reactor physics benchmarking activities provided a collation of mixed results that inaccurately predicted actual experimental performance.1 Reevaluations were performed by the Japanese to reduce the discrepancy between actual and computationally-determined critical configurations.2-3 Current efforts at the Idaho National Laboratory (INL) involve development of reactor physics benchmark models in conjunction with the International Reactor Physics Experiment Evaluation Project (IRPhEP) for use with verification and validation methods in the VHTR Program. Annular cores demonstrate inherent safety characteristics that are of interest in developing future HTGRs.

  9. MCNP/MCNPX model of the annular core research reactor.

    Energy Technology Data Exchange (ETDEWEB)

    DePriest, Kendall Russell; Cooper, Philip J.; Parma, Edward J., Jr. (.,; .)

    2006-10-01

    Many experimenters at the Annular Core Research Reactor (ACRR) have a need to predict the neutron/gamma environment prior to testing. In some cases, the neutron/gamma environment is needed to understand the test results after the completion of an experiment. In an effort to satisfy the needs of experimenters, a model of the ACRR was developed for use with the Monte Carlo N-Particle transport codes MCNP [Br03] and MCNPX [Wa02]. The model contains adjustable safety, transient, and control rods, several of the available spectrum-modifying cavity inserts, and placeholders for experiment packages. The ACRR model was constructed such that experiment package models can be easily placed in the reactor after being developed as stand-alone units. An addition to the 'standard' model allows the FREC-II cavity to be included in the calculations. This report presents the MCNP/MCNPX model of the ACRR. Comparisons are made between the model and the reactor for various configurations. Reactivity worth curves for the various reactor configurations are presented. Examples of reactivity worth calculations for a few experiment packages are presented along with the measured reactivity worth from the reactor test of the experiment packages. Finally, calculated neutron/gamma spectra are presented.

  10. Development of an annular arc accelerator shock tube driver

    Science.gov (United States)

    Leibowitz, L. P.

    1973-01-01

    An annular arc accelerator (ANAA) shock tube driver has been developed that deposits the energy of an arc discharge into a flowing gas, which then expands and cools without any delay for the opening of a diaphragm. A simplified one-dimensional flow analysis of the ANAA shock tube has been performed, which indicates that shock velocities greater than 40 km/sec may be obtained using a 300-kJ capacitor bank. The ANAA driver consists of a high-pressure driver, an expansion section, and an electrode section. In operation, the cold gas driver is pressurized until the diaphragm bursts, sending a pressure front down the expansion tube to the arc section. When the accelerated flow arrives at the electrode section, a 100-capacitor, 300-kJ capacitor bank is discharged either by breaking an insulating diaphragm between the electrodes or by the triggering of a series of external switches. Shock velocities of 28 km/sec have been obtained, and modifications are described that are expected to improve performance.

  11. An Unusual Presentation of Annular Pancreas: A Case Report

    Directory of Open Access Journals (Sweden)

    Saleheh Ala

    2015-01-01

    Full Text Available Abstract Annular pancreas (AP is a rare congenital malformation resulting from failure of pancreas ventral anlage rotation with the duodenum. This leads to a ring of pancreatic tissue that envelops the duodenum. Clinical manifestations of AP most commonly develop in infancy or early childhood but can present at any age. The diagnosis of AP, usually suggested by an upper GI series or abdominal CT scan, but surgery is considered the gold standard diagnostic method. Surgical bypass of the annulus in all patients with symptomatic AP is recommended. We report a one year old girl who presented with intermittent, non projectile, non bilious vomiting that occurred 1h to 2h after feeding since neonatal period. Upper GI contrast study demonstrates, a dilated duodenal bulb associated with narrowing of post bulbar area. The patient underwent surgical correction of the obstruction. A bypass of the ectopic pancreas tissue was performed by duodenoduodenostomy. Considering the rarity of this congenital abnormality, presenting with chronic partial duodenal obstruction, and its successful correction by surgical means have prompted us to report the case.

  12. Modeling and analysis of thermoacoustic instabilities in an annular combustor

    Science.gov (United States)

    Murthy, Sandeep; Sayadi, Taraneh; Le Chenadec, Vincent; Schmid, Peter

    2015-11-01

    A simplified model is introduced to study thermo-acoustic instabilities in axisymmetric combustion chambers. Such instabilities can be triggered when correlations between heat-release and pressure oscillations exist, leading to undesirable effects. Gas turbine designs typically consist of a periodic assembly of N identical units; as evidenced by documented studies, the coupling across sectors may give rise to unstable modes, which are the highlight of this study. In the proposed model, the governing equations are linearized in the acoustic limit, with each burner modeled as a one-dimensional system, featuring acoustic damping and a compact heat source. The coupling between the burners is accounted for by solving the two-dimensional wave equation over an annular region, perpendicular to the burners, representing the chamber's geometry. The discretization of these equations results in a set of coupled delay-differential equations, that depends on a finite set of parameters. The system's periodicity is leveraged using a recently developed root-of-unity formalism (Schmid et al., 2015). This results in a linear system, which is then subjected to modal and non-modal analysis to explore the influence of the coupled behavior of the burners on the system's stability and receptivity.

  13. Flow Pressure Loss through Straight Annular Corrugated Pipes

    Science.gov (United States)

    Sargent, Joseph R.; Kirk, Daniel R.; Marsell, Brandon; Roth, Jacob; Schallhorn, Paul A.; Pitchford, Brian; Weber, Chris; Bulk, Timothy

    2016-01-01

    Pressure loss through annular corrugated pipes, using fully developed gaseous nitrogen representing purge pipes in spacecraft fairings, was studied to gain insight into a friction factor coefficient for these pipes. Twelve pipes were tested: four Annuflex, four Masterflex and two Titeflex with ¼”, 3/8”, ½” and ¾” inner diameters. Experimental set-up was validated using smooth-pipe and showed good agreement to the Moody diagram. Nitrogen flow rates between 0-200 standard cubic feet per hour were used, producing approximate Reynolds numbers from 300-23,000. Corrugation depth varied from 0.248 = E/D = 0.349 and relative corrugation pitch of 0.192 = P/D = 0.483. Differential pressure per unit length was measured and calculated using 8-9 equidistant pressure taps. A detailed experimental uncertainty analysis, including correlated bias error terms, is presented. Results show larger differential pressure losses than smooth-pipes with similar inner diameters resulting in larger friction factor coefficients.

  14. Mathematical behavior and computation of transmission probabilities for annular regions

    International Nuclear Information System (INIS)

    One convenient way of treating neutron transport problems is to use the transmission probability method. For cylindrical geometry consisting of many annular subregions, this method can be formulated in terms of T/sub i//sup OO/, the transmission probability from the outer-to-outer surface of the i-th annulus, and T/sub i//sup OI/, the transmission probability from the inner-to-outer surface of the i-th annulus. The quantities T/sub i//sup OO/ and T/sub i//sup OI/ are extremely complex functions of r/sub i-1//r/sub i/, the ratio of the inner-to-outer radius, and the optical path length r/sub i/Σ/sub ti/ for region i. The latter quantity can have a wide range of values in the problems of practical interest. This paper describes new, improved methods for treating these transmission probabilities on the basis of their individual mathematical properties. These improved methods have three objectives: to provide a rigorous treatment of the asymptotic behavior of these functions, which is currently lacking in the MC2-2 code; to provide a separate treatment of T/sub i//sup OO/ and T/sub i//sup OI/ according to their distinct functional dependencies; to eliminate the two-dimensional tables currently in use to obtain these functions in the MC2-2 code. 2 figures

  15. Measurement of large aspheric surfaces by annular subaperture stitching interferometry

    Institute of Scientific and Technical Information of China (English)

    Xiaokun Wang; Lihui Wang; Longhai Yin; Binzhi Zhang; Di Fan; Xuejun Zhang

    2007-01-01

    A new method for testing aspheric surfaces by annular subaperture stitching interferometry is introduced.It can test large-aperture and large-relative-aperture aspheric surfaces at high resolution, low cost, and high efficiency without auxiliary null optics. The basic principle of the method is described, the synthetical optimization stitching model and effective algorithm are established based on simultaneous least-square fitting. A hyperboloid with an aperture of 350 mm is tested by this method. The obtained peak-to-valley (PV) and root-mean-square (RMS) values of the surface error after stitching are 0.433λ and 0.052λ (λis 632.8 nm), respectively. The reconstructed surface map is coincide with the entire surface map from null test, and the difference of PV and RMS errors between them are 0.031λ and 0.005λ, respectively.This stitching model provides another quantitive method for testing large aspheric surfaces besides null compensation.

  16. Pollution technology program, can-annular combustor engines

    Science.gov (United States)

    Roberts, R.; Fiorentino, A. J.; Greene, W.

    1976-01-01

    A Pollution Reduction Technology Program to develop and demonstrate the combustor technology necessary to reduce exhaust emissions for aircraft engines using can-annular combustors is described. The program consisted of design, fabrication, experimental rig testing and assessment of results and was conducted in three program elements. The combustor configurations of each program element represented increasing potential for meeting the 1979 Environmental Protection Agency (EPA) emission standards, while also representing increasing complexity and difficulty of development and adaptation to an operational engine. Experimental test rig results indicate that significant reductions were made to the emission levels of the baseline JT8D-17 combustor by concepts in all three program elements. One of the Element I single-stage combustors reduced carbon monoxide to a level near, and total unburned hydrocarbons (THC) and smoke to levels below the 1979 EPA standards with little or no improvement in oxides of nitrogen. The Element II two-stage advanced Vorbix (vortex burning and mixing) concept met the standard for THC and achieved significant reductions in CO and NOx relative to the baseline. Although the Element III prevaporized-premixed concept reduced high power NOx below the Element II results, there was no improvement to the integrated EPA parameter relative to the Vorbix combustor.

  17. NB-UVB phototherapy for generalized granuloma annulare.

    Science.gov (United States)

    Pavlovsky, Mor; Samuelov, Liat; Sprecher, Eli; Matz, Hagit

    2016-05-01

    Granuloma annulare (GA) is a benign, usually self-limited, granulomatous skin disease of unknown etiology. The generalized form of the disease shows a more chronic, relapsing course, rare spontaneous resolution, and poorer response to therapy. Psoralen plus UVA phototherapy has been reported to be effective for GA. However, little is known regarding the efficacy of narrowband UVB phototherapy. Our goal was to determine the efficacy of NB-UVB phototherapy in generalized GA. We carried out a retrospective study of patients with generalized GA treated with NB-UVB phototherapy over a period of 3 years. On completion of treatment, outcome was assessed as complete response (complete clearance of the lesions), partial response (>50% clearance of the lesions), and poor response (<50% clinical response). Therapy was stopped if no improvement was seen after 20 treatments. Thirteen patients were included in the study. 54% of patients treated with NB-UVB had a complete/partial response by the end of the treatment period. NB-UVB phototherapy was well-tolerated, with no serious adverse effects. NB-UVB phototherapy is effective in a substantial portion of patients with generalized GA. To determine the true efficacy of this therapeutic modality, a prospective study comparing it to PUVA is warranted. PMID:26626163

  18. Annular flow entrainment rate experiment in a small vertical pipe

    International Nuclear Information System (INIS)

    Two-fluid model predictions of film dryout in annular flow, leading to nuclear reactor fuel failure, are limited by the uncertainties in the constitutive relations for the entrainment rate of droplets from the liquid film. The main cause of these uncertainties is the lack of separate-effects experimental data in the range of the operating conditions in nuclear power reactors. An air-water experiment has been performed to measure the entrainment rate in a small pipe. The current data extend the available database in the literature to higher gas and liquid flows and also to higher pressures. The measurements were made with the film extraction technique. A mechanistic model was obtained based on Kelvin-Helmholtz' instability theory. The dimensionless model includes the Weber number of the gas and the liquid film Reynolds number. Kataoka and Ishii's correlation (Kataoka, I., Ishii, M., (1982)) is modified based on this model and the new data. The new correlation collapses the present air-water data and Cousins and Hewitt's data (Cousins, L.B. (1968)) The effects of pressure and surface tension were considered in the derivation so it may be applied for boiling water reactor operating conditions. (orig.)

  19. 8-isorpostanes – markers for oxidative stress in obstructive sleep apnea patients with systolic dysfunction

    Directory of Open Access Journals (Sweden)

    Cherneva RV

    2013-06-01

    Full Text Available Radostina Vlaeva Cherneva,1 Ognian Borisov Georgiev,1 Daniela Stoichkova Petrova,1 Emil Ivanov Manov,2 Sylvia Rumenova Ruseva,3 Vanio Ivanov Mitev,3 Julia Ivanova Petrova4 1Department of Internal Medicine, Division of Pulmonary Medicine, Medical University of Sofia, Sofia, Bulgaria; 2Department of Internal Medicine, Division of Cardiology, Medical University of Sofia, Sofia, Bulgaria; 3Department of Medical Chemistry and Biochemistry, Laboratory of Synthesis and Analysis of Bioactive Substances, Medical University of Sofia, Sofia, Bulgaria; 4Department of Neurology, Medical University of Sofia, Sofia, Bulgaria Objective: Increased oxidative stress is considered to be an independent risk factor for cardiovascular diseases, but remains disputed in obstructive sleep apnea (OSA. Among oxidative stress markers, isorpostanes are considered to be the most sensitive and specific. Aims: The aim of the study was to compare urinary isorpostanes in patients with OSA and systolic dysfunction to patients with OSA and preserved ejection fraction (EF and determine their role as markers for increased oxidative stress and early cardiac damage. Materials and methods: Urinary 8F2-isorpostanes were measured in 30 patients with OSA and mild systolic dysfunction (EF = 45.7% ± 6.17% and compared to 15 patients with OSA and normal EF (EF = 60.3% ± 6.3%. Univariate regression analysis was performed to find predictors of left systolic dysfunction. Correlations between 8-isorpostanes, anthropometric, metabolic, and sleep study characteristics were explored. In addition, in 19 patients the effect of bilevel positive airway pressure (BiPAP therapy was evaluated during a 3 month follow-up. Markers of hemodynamic stress, N-terminal prohormone of brain natriuretic peptide and oxidative stress, measured by 8-isorpostanes were compared before and after the follow-up. Results: Urinary levels of 8-isorpostanes were significantly higher in the group with mild systolic dysfunction

  20. Natriuretic peptide vs. clinical information for diagnosis of left ventricular systolic dysfunction in primary care

    Directory of Open Access Journals (Sweden)

    Wachter Rolf

    2008-02-01

    Full Text Available Abstract Background Screening of primary care patients at risk for left ventricular systolic dysfunction by a simple blood-test might reduce referral rates for echocardiography. Whether or not natriuretic peptide testing is a useful and cost-effective diagnostic instrument in primary care settings, however, is still a matter of debate. Methods N-terminal pro-brain natriuretic peptide (NT-proBNP levels, clinical information, and echocardiographic data of left ventricular systolic function were collected in 542 family practice patients with at least one cardiovascular risk factor. We determined the diagnostic power of the NT-proBNP assessment in ruling out left ventricular systolic dysfunction and compared it to a risk score derived from a logistic regression model of easily acquired clinical information. Results 23 of 542 patients showed left ventricular systolic dysfunction. Both NT-proBNP and the clinical risk score consisting of dyspnea at exertion and ankle swelling, coronary artery disease and diuretic treatment showed excellent diagnostic power for ruling out left ventricular systolic dysfunction. AUC of NT-proBNP was 0.83 (95% CI, 0.75 to 0.92 with a sensitivity of 0.91 (95% CI, 0.71 to 0.98 and a specificity of 0.46 (95% CI, 0.41 to 0.50. AUC of the clinical risk score was 0.85 (95% CI, 0.79 to 0.91 with a sensitivity of 0.91 (95% CI, 0.71 to 0.98 and a specificity of 0.64 (95% CI, 0.59 to 0.67. 148 misclassifications using NT-proBNP and 55 using the clinical risk score revealed a significant difference (McNemar test; p Conclusion The evaluation of clinical information is at least as effective as NT-proBNP testing in ruling out left ventricular systolic dysfunction in family practice patients at risk. If these results are confirmed in larger cohorts and in different samples, family physicians should be encouraged to rely on the diagnostic power of the clinical information from their patients.

  1. Explosive plane-wave lens

    Science.gov (United States)

    Marsh, Stanley P.

    1988-01-01

    An explosive plane-wave air lens which enables a spherical wave form to be converted to a planar wave without the need to specially machine or shape explosive materials is described. A disc-shaped impactor having a greater thickness at its center than around its periphery is used to convert the spherical wave into a plane wave. When the wave reaches the impactor, the center of the impactor moves first because the spherical wave reaches the center of the impactor first. The wave strikes the impactor later in time as one moves radially along the impactor. Because the impactor is thinner as one moves radially outward, the velocity of the impactor is greater at the periphery than at the center. An acceptor explosive is positioned so that the impactor strikes the acceptor simultaneously. Consequently, a plane detonation wave is propagated through the acceptor explosive.

  2. Plane waves as tractor beams

    Science.gov (United States)

    Forgács, Péter; Lukács, Árpád; Romańczukiewicz, Tomasz

    2013-12-01

    It is shown that in a large class of systems, plane waves act as tractor beams: i.e., an incident plane wave can exert a pulling force on the scatterer. The underlying physical mechanism for the pulling force is due to the sufficiently strong scattering of the incoming wave into another mode carrying more momentum, in which case excess momentum is created behind the scatterer. This tractor beam or negative radiation pressure (NRP) effect, is found to be generic in systems with multiple scattering channels. In a birefringent medium, electromagnetic plane waves incident on a thin plate exert NRP of the same order of magnitude as optical radiation pressure, while in artificial dielectrics (metamaterials), the magnitude of NRP can even be macroscopic. In two dimensions, we study various scattering situations on vortices, and NRP is shown to occur by the scattering of heavy baryons into light leptons off cosmic strings, and by neutron scattering off vortices in the XY model.

  3. Plane waves in noncommutative fluids

    International Nuclear Information System (INIS)

    We study the dynamics of the noncommutative fluid in the Snyder space perturbatively at the first order in powers of the noncommutative parameter. The linearized noncommutative fluid dynamics is described by a system of coupled linear partial differential equations in which the variables are the fluid density and the fluid potentials. We show that these equations admit a set of solutions that are monochromatic plane waves for the fluid density and two of the potentials and a linear function for the third potential. The energy–momentum tensor of the plane waves is calculated.

  4. Plane waves in noncommutative fluids

    Science.gov (United States)

    Abdalla, M. C. B.; Holender, L.; Santos, M. A.; Vancea, I. V.

    2013-08-01

    We study the dynamics of the noncommutative fluid in the Snyder space perturbatively at the first order in powers of the noncommutative parameter. The linearized noncommutative fluid dynamics is described by a system of coupled linear partial differential equations in which the variables are the fluid density and the fluid potentials. We show that these equations admit a set of solutions that are monochromatic plane waves for the fluid density and two of the potentials and a linear function for the third potential. The energy-momentum tensor of the plane waves is calculated.

  5. Plane waves in noncommutative fluids

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, M.C.B., E-mail: mabdalla@ift.unesp.br [Instituto de Física Teórica, UNESP, Universidade Estadual Paulista, Rua Dr. Bento Teobaldo Ferraz 271, Bloco 2, Barra-Funda, Caixa Postal 70532-2, 01156-970, São Paulo, SP (Brazil); Holender, L., E-mail: holender@ufrrj.br [Grupo de Física Teórica e Matemática Física, Departamento de Física, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Cx. Postal 23851, BR 465 Km 7, 23890-000 Seropédica, RJ (Brazil); Santos, M.A., E-mail: masantos@cce.ufes.br [Departamento de Física e Química, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferarri S/N, Goiabeiras, 29060-900 Vitória, ES (Brazil); Vancea, I.V., E-mail: ionvancea@ufrrj.br [Grupo de Física Teórica e Matemática Física, Departamento de Física, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Cx. Postal 23851, BR 465 Km 7, 23890-000 Seropédica, RJ (Brazil)

    2013-08-01

    We study the dynamics of the noncommutative fluid in the Snyder space perturbatively at the first order in powers of the noncommutative parameter. The linearized noncommutative fluid dynamics is described by a system of coupled linear partial differential equations in which the variables are the fluid density and the fluid potentials. We show that these equations admit a set of solutions that are monochromatic plane waves for the fluid density and two of the potentials and a linear function for the third potential. The energy–momentum tensor of the plane waves is calculated.

  6. Multivariate Modeling of Body Mass Index, Pulse Pressure, Systolic and Diastolic Blood Pressure in Chinese Twins

    DEFF Research Database (Denmark)

    Wu, Yili; Zhang, Dongfeng; Pang, Zengchang;

    2015-01-01

    Systolic and diastolic blood pressure, pulse pressure (PP), and body mass index (BMI) are heritable traits in human metabolic health but their common genetic and environmental backgrounds are not well investigated. The aim of this article was to explore the phenotypic and genetic associations among...... PP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and BMI. The studied sample contained 615 twin pairs (17-84 years) collected in the Qingdao municipality. Univariate and multivariate structural equation models were fitted for assessing the genetic and environmental contributions...... multivariate model estimated (1) high genetic correlations for DBP with SBP (0.87), PP with SBP (0.75); (2) low-moderate genetic correlations between PP and DBP (0.32), each BP component and BMI (0.24-0.37); (3) moderate unique environmental correlation for PP with SBP (0.68) and SBP with DBP (0.63); (4) there...

  7. Use of different types of angiotensin converting enzyme inhibitors and mortality in systolic heart failure

    DEFF Research Database (Denmark)

    Svanström, Henrik; Pasternak, Björn; Melbye, Mads;

    2015-01-01

    on the comparable effectiveness of different ACEIs is scarce. We conducted a registry-based cohort study to assess all-cause mortality associated with the use of enalapril, perindopril, and trandolapril, as compared with ramipril, in patients with systolic HF. METHODS: Patients with systolic HF (EF ≤40%), 2003......-2012, were identified using the Danish HF Registry. New users of enalapril (n=1807), perindopril (n=1064), ramipril (n=3270), or trandolapril (n=1150), who started treatment within 60days of first-time hospital diagnosis of HF, were selected for inclusion. Subgroup analyses were conducted by sex, age, NYHA......-level, EF, and ischemic heart disease. All analyses were adjusted for empirical risk scores for mortality. RESULTS: During follow-up, 291 deaths were observed among users of enalapril (incidence rate per 100person-years [IR], 10.1), 212 among users of perindopril (IR, 10.5), 568 among users of ramipril (IR...

  8. 5-Fluorouracil cardiotoxicity: reversible left ventricular systolic dysfunction with early detection.

    Science.gov (United States)

    Iskandar, Muhammad Zaid; Quasem, Wahid; El-Omar, Magdi

    2015-01-01

    A 33-year-old man presented to hospital with acute shortness of breath and evolving ST segment changes on ECG 3 days following a cycle of 5-fluorouracil (5-FU) for colon cancer. Despite no cardiac history, subsequent echocardiogram showed severe left ventricular systolic dysfunction. The patient was initially treated with heart failure medications and his coronary angiogram was normal. Chemotherapy was stopped and he was started on nitrates and calcium channel blockers. A repeat echocardiogram and cardiac MRI a week later showed complete resolution of his left ventricular dysfunction and he was discharged home. This case report summarises 5-FU cardiotoxicity, and emphasises the importance of early recognition and correct treatment, as left ventricular systolic dysfunction in this context is potentially reversible. PMID:25935919

  9. Quantifying the uncertainty of the annular mode time scale and the role of the stratosphere

    Science.gov (United States)

    Kim, Junsu; Reichler, Thomas

    2015-10-01

    The proper simulation of the annular mode time scale may be regarded as an important benchmark for climate models. Previous research demonstrated that this time scale is systematically overestimated by climate models. As suggested by the fluctuation-dissipation theorem, this may imply that climate models are overly sensitive to external forcings. Previous research also made it clear that calculating the AM time scale is a slowly converging process, necessitating relatively long time series and casting doubts on the usefulness of the historical reanalysis record to constrain climate models in terms of the annular mode time scale. Here, we use long control simulations with the coupled and uncoupled version of the GFDL climate model, CM2.1 and AM2.1, respectively, to study the effects of internal atmospheric variability and forcing from the lower boundary on the stability of the annular mode time scale. In particular, we ask whether a model's annular mode time scale and dynamical sensitivity can be constrained from the 50-year-long reanalysis record. We find that internal variability attaches large uncertainty to the annular mode time scale when diagnosed from decadal records. Even under the fixed forcing conditions of our long control run at least 100 years of data are required in order to keep the uncertainty in the annular mode time scale of the Northern Hemisphere to 10 %; over the Southern Hemisphere, the required length increases to 200 years. If nature's annular mode time scale over the Northern Hemisphere is similarly variable, there is no guarantee that the historical reanalysis record is a fully representative target for model evaluation. Over the Southern Hemisphere, however, the discrepancies between model and reanalysis are sufficiently large to conclude that the model is unable to reproduce the observed time scale structure correctly. The effects of ocean coupling lead to a considerable increase in time scale and uncertainty in time scale, effects which

  10. Low systolic blood pressure and self perceived wellbeing in middle aged men.

    OpenAIRE

    Rosengren, A; Tibblin, G; Wilhelmsen, L

    1993-01-01

    OBJECTIVE--To examine the relation between systolic blood pressure and self perceived wellbeing in 50 year old men. DESIGN--Cross sectional population study of data derived from questionnaires and physical examination as a part of a cardiovascular risk factor survey. SETTING--City of Gothenburg, Sweden. STUDY POPULATION--776 men from a random population sample of 1016 men aged 50. METHODS--Self perceived wellbeing according to the Gothenburg quality of life questionnaire, which is an assessme...

  11. Congestive heart failure. Correlation between functional class and systolic and diastolic functions assessed by Doppler echocardiography

    Directory of Open Access Journals (Sweden)

    Kamel Cesar Selem

    2001-01-01

    Full Text Available OBJECTIVE: To evaluate the influence of systolic or diastolic dysfunction, or both on congestive heart failure functional class. METHODS: Thirty-six consecutive patients with a clinical diagnosis of congestive heart failure with sinus rhythm, who were seen between September and November of 1998 answered an adapted questionnaire about tolerance to physical activity for the determination of NYHA functional class. The patients were studied with transthoracic Doppler echocardiography. Two groups were compared: group 1 (19 patients in functional classes I and II and group 2 (17 patients in functional classes III and IV. RESULTS: The average ejection fraction was significantly higher in group 1 (44.84%±8.04% vs. 32.59%±11.48% with p=0.0007. The mean ratio of the initial/final maximum diastolic filling velocity (E/A of the left ventricle was significantly smaller in group 1 (1.07±0.72 vs. 1.98±1.49 with p=0.03. The average maximum systolic pulmonary venous velocity (S was significantly higher in group 1 (53.53cm/s ± 12.02cm/s vs. 43.41cm/s ± 13.55cm/s with p=0.02. The mean ratio of maximum systolic/diastolic pulmonary venous velocity was significantly higher in group 1 (1.52±0.48 vs. 1.08±0.48 with p=0.01. A predominance of pseudo-normal and restrictive diastolic patterns existed in group 2 (58.83% in group 2 vs. 21.06% in group 1 with p=0.03. CONCLUSION: Both the systolic dysfunction index and the patterns of diastolic dysfunction evaluated by Doppler echocardiography worsened with the evolution of congestive heart failure.

  12. The Long Myocardial Bridging Case Causing Severe Systolic Narrowing; How Should Approach?

    OpenAIRE

    ERCAN, Süleyman; Alıcı, Mehmet Hayri; DAVUTOĞLU, Vedat; Çakıcı, Musa; Oylumlu, Muhammed

    2012-01-01

    Myocardial bridging, characterized in myocardial systolic blood flow is prevented due to compression of a coronary artery segment. This condition detected by coronary angiography is usually accepted benign. A 52 years old man, who had effort angina for three months, has been diagnosed non-critical plaque and long segment myocardial bridging by coronary angiography. We want to share with this case, non-critical plaque together with myocardial bridging caused stable angina and we aimed to appro...

  13. The Long Myocardial Bridging Case Causing Severe Systolic Narrowing; How Should Approach?

    OpenAIRE

    Süleyman Ercan; Mehmet Hayri Alıcı; Vedat Davutoğlu; Musa Çakıcı; Muhammed Oylumlu

    2013-01-01

    Myocardial bridging, characterized in myocardial systolic blood flow is prevented due to compression of a coronary artery segment. This condition detected by coronary angiography is usually accepted benign. A 52 years old man, who had effort angina for three months, has been diagnosed non-critical plaque and long segment myocardial bridging by coronary angiography. We want to share with this case, non-critical plaque together with myocardial bridging caused stable angina and we aimed to app...

  14. Pharmacist intervention in primary care to improve outcomes in patients with left ventricular systolic dysfunction

    OpenAIRE

    Lowrie, R.; Mair, F S; Greenlaw, N.; Forsyth, P.; Jhund, P.S.; McConnachie, A.; Rae, B.; McMurray, J.J.V.

    2012-01-01

    Background Meta-analysis of small trials suggests that pharmacist-led collaborative review and revision of medical treatment may improve outcomes in heart failure. Methods and results We studied patients with left ventricular systolic dysfunction in a cluster-randomized controlled, event driven, trial in primary care. We allocated 87 practices (1090 patients) to pharmacist intervention and 87 practices (1074 patients) to usual care. The intervention was delivered by non-specialist pharmac...

  15. Effects of Everolimus-Eluting Stents on the Left Ventricular Systolic and Diastolic Functions

    OpenAIRE

    MohammadSadegh Parsaee; Maryam Nabati; Naser Saffar; Morteza Taghavi

    2015-01-01

    Background: The drug-eluting stent (DES) decreases the rate of coronary restenosis and re-obstruction. The aim of this study was to assess prospectively the effectiveness of the new generation DES on the left ventricular (LV) systolic and diastolic functions in patients with isolated severe proximal left anterior descending (LAD) coronary artery stenosis.Methods: A prospective study was conducted on 50 patients with isolated severe proximal LAD stenosis. Successful percutaneous coronary inter...

  16. Doppler-derived myocardial systolic strain rate is a strong index of left ventricular contractility

    Science.gov (United States)

    Greenberg, Neil L.; Firstenberg, Michael S.; Castro, Peter L.; Main, Michael; Travaglini, Agnese; Odabashian, Jill A.; Drinko, Jeanne K.; Rodriguez, L. Leonardo; Thomas, James D.; Garcia, Mario J.

    2002-01-01

    BACKGROUND: Myocardial fiber strain is directly related to left ventricular (LV) contractility. Strain rate can be estimated as the spatial derivative of velocities (dV/ds) obtained by tissue Doppler echocardiography (TDE). The purposes of the study were (1) to determine whether TDE-derived strain rate may be used as a noninvasive, quantitative index of contractility and (2) to compare the relative accuracy of systolic strain rate against TDE velocities alone. METHODS AND RESULTS: TDE color M-mode images of the interventricular septum were recorded from the apical 4-chamber view in 7 closed-chest anesthetized mongrel dogs during 5 different inotropic stages. Simultaneous LV volume and pressure were obtained with a combined conductance-high-fidelity pressure catheter. Peak elastance (Emax) was determined as the slope of end-systolic pressure-volume relationships during caval occlusion and was used as the gold standard of LV contractility. Peak systolic TDE myocardial velocities (Sm) and peak (epsilon'(p)) and mean (epsilon'(m)) strain rates obtained at the basal septum were compared against Emax by linear regression. Emax as well as TDE systolic indices increased during inotropic stimulation with dobutamine and decreased with the infusion of esmolol. A stronger association was found between Emax and epsilon'(p) (r=0.94, P<0.01, y=0.29x+0.46) and epsilon'(m) (r=0.88, P<0.01) than for Sm (r=0.75, P<0.01). CONCLUSIONS: TDE-derived epsilon'(p) and epsilon'(m) are strong noninvasive indices of LV contractility. These indices appear to be more reliable than S(m), perhaps by eliminating translational artifact.

  17. Dietary zinc intake is inversely associated with systolic blood pressure in young obese women

    OpenAIRE

    Kim, Jihye

    2013-01-01

    Zinc may participate in blood pressure regulation and in the pathogenesis of hypertension. The study examined the relationship between zinc status and blood pressure in obese Korean women. Forty obese women (body mass index (BMI) ≥ 25 kg/m2) aged 19-28 years participated in this study. Zinc intake was estimated from one 24 hour recall and 2-day diet records. Serum and urinary zinc concentrations were determined by atomic absorbance spectrophotometry. Systolic blood pressure (SBP) and diastoli...

  18. Relationship between aetiology and left ventricular systolic dysfunction in hypertrophic cardiomyopathy

    OpenAIRE

    Rosmini, Stefania

    2015-01-01

    Background: Hypertrophic cardiomyopathy (HCM) is a common cardiac disease caused by a range of genetic and acquired disorders. The most common cause is genetic variation in sarcomeric proteins genes. Current ESC guidelines suggest that particular clinical features (‘red flags’) assist in differential diagnosis. Aims: To test the hypothesis that left ventricular (LV) systolic dysfunction in the presence of increased wall thickness is an age-specific ‘red flag’ for aetiological diagnosis an...

  19. Analysis of end-systolic pressure-volume relation by gated radionuclide angiocardiography

    International Nuclear Information System (INIS)

    Left ventricular end-systolic pressure-volume relation has been proved experimentally to b e an useful index of left ventricular contractility relatively independent of preload or afterload. But less clinical application has been reported because of its invasive nature, and we evaluated this relationship non-invasively using gated radionuclide angiocardiography as volume determination and cuff sphyngomanometer in the arm as pressure measurement. Gated equilibrium blood pool scintigrams were obtained at rest and during intravenous infusion of angiotensin or nitrate. Ventricular volumes were derived from ventricular activity and peripheral blood volume and activity. The peak systolic pressure (PSP) by cuff method to end-systolic volume index (ESVI) relations showed good linearity (r gt .930 in 84% of consecutive 50 cases) and were gentler in the groups with more impaired left ventricular function. Emax was related exponentially to ejection fraction (EF) and hyperbolically to end-diastolic volume index. The dead volume (VoI) was unfixed and fell into positive or negative value, and was not related to EF under control condition. PSP/ESVI in each loading condition was less variable with the alteration of blood pressure than EF. The linear relation was found between PSP/ESVI under control condition and Emax (PSP/ESVI = 0.651.Emax + 0.958, r = 0.841, p lt .001). Thus in measuring ventricular volume, gated radionuclide angiocardiography is a non-invasive method less affected by the geometry of the left ventricle. Non-invasive determination of end-systolic pressure-volume relation using the volume by radionuclide and the blood pressure by cuff method is clinically useful in the assessment of left ventricular contractility. (author)

  20. Non Invasive Measurement of Systolic Blood Pressure in Rats: A Simple Technique

    OpenAIRE

    Maria Pauline; Avadhany, Sandhya T.; K.N. Maruthy

    2011-01-01

    Background: Non invasive, simple and economical instrument to measure blood pressure in r365-ats is important in cardiovascular research. Methods: Systolic blood pressure measuring instrument was fabricated using a tail cuff, photoplethysmograph, pressure transducer and PC with Biopac Software for recording. Tail cuff was used to occlude the tail artery, photoplethysmograph picked the blood flow pulses in the rat tail and the pressure transducer measured the cuff pressure and converted it int...

  1. Comparison of Systolic Blood Pressure Values Obtained by Photoplethysmography and by Korotkoff Sounds

    OpenAIRE

    Michael Bursztyn; Ben-Dov, Iddo Z.; Eran Shalom; Shlomo Engelberg; Ellie Hoffman; Yair Adar; Meir Nitzan

    2013-01-01

    In the current study, a non-invasive technique for systolic blood pressure (SBP) measurement based on the detection of photoplethysmographic (PPG) pulses during pressure-cuff deflation was compared to sphygmomanometry—the Korotkoff sounds technique. The PPG pulses disappear for cuff-pressures above the SBP value and reappear when the cuff-pressure decreases below the SBP value. One hundred and twenty examinations were performed on forty subjects. In 97 examinations the two methods differed by...

  2. Testosterone level and mortality in elderly men with systolic chronic heart failure

    OpenAIRE

    Wu, Hai-Yun; Wang, Xiao-Fei; Wang, Jun-Hua; Li, Jiang-Yuan

    2011-01-01

    Previous studies on the prognostic significance of serum levels of androgens in patients with chronic heart failure (CHF) have yielded conflicting results. The aim of this study was to examine the relationship between serum concentration of testosterone and mortality in men with systolic CHF. A total of 175 elderly men (age≥60 years) with CHF were recruited. Total testosterone (TT) and sex hormone-binding globulin (SHBG) were measured, and estimated free testosterone (eFT) was calculated. The...

  3. Pulse pressure variation and systolic pressure variation in mechanically ventilated children

    OpenAIRE

    Johnny Nurman; Antonius H. Pudjiadi; Arwin AP. Akib

    2011-01-01

    Background In mechanically ventilated patients, changes in breathing patterns may affect the preload, causing stroke volume fluctuation. Pulse pressure variation (PPV) and systolic pressure variation (SPV) are dynamic means of the hemodynamic monitoring in ventilated patients. No study on PPV and SPV in children has been reported to date. Objective To study changes in PPV and SPV values in mechanically ventilated children. Method A descriptive cross-sectional study was done at the Pedia...

  4. Association of Interarm Systolic Blood Pressure Difference with Atherosclerosis and Left Ventricular Hypertrophy

    OpenAIRE

    Su, Ho-Ming; Lin, Tsung-Hsien; Hsu, Po-Chao; Chu, Chun-Yuan; Lee, Wen-Hsien; Chen, Szu-Chia; Lee, Chee-Siong; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung

    2012-01-01

    An interarm systolic blood pressure (SBP) difference of 10 mmHg or more have been associated with peripheral artery disease and adverse cardiovascular outcomes. We investigated whether an association exists between this difference and ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), and echocardiographic parameters. A total of 1120 patients were included in the study. The bilateral arm blood pressures were measured simultaneously by an ABI-form device. The values of ABI...

  5. Predictors of high central blood pressure in young with isolated systolic hypertension

    OpenAIRE

    Radchenko, Ganna; Torbas,Olena; Sirenko, Yuriy

    2016-01-01

    G D Radchenko, O O Torbas, Yu M Sirenko State Institute National Scientific Center, M.D. Strazhesko Institute of Cardiology, National Academy of Medical Science, Kyiv, Ukraine Objective: According to the European Society of Cardiology/European Society of Hypertension 2013 guidelines, evaluation of aortic blood pressure (BP) is needed in young with isolated systolic hypertension (ISH), but using special devices is not common, especially in Ukraine, where only a few centers ha...

  6. Elevated Middle Cerebral Artery Peak Systolic Velocity in a Nonanemic Fetus with Alpha-Thalassemia Trait

    OpenAIRE

    Kent Heyborne

    2009-01-01

    Background. Elevated middle cerebral artery peak systolic velocity (MCA-PSV) has been reported in nonanemic fetuses following fetal transfusion, and has been attributed to a major population of red blood cells (RBCs) with an adult mean corpuscular volume (MCV) in the fetal circulation. Reported here is an analogous case of elevated MCA-PSV with a normal fetal hematocrit and relative fetal microcytosis due to fetal α-thalassemia trait. Case. Ultrasound findings concerning for early hydrops pro...

  7. Multivariate models for human genetic analysis: aggregation, coaggregation, and tracking of systolic blood pressure and weight.

    OpenAIRE

    Hanis, C. L.; Sing, C. F.; Clarke, W. R.; Schrott, H G

    1983-01-01

    A multivariate path model parameterizing the sources of familial aggregation and coaggregation of systolic blood pressure and weight, as well as their tracking across time, is applied to longitudinal data collected in Muscatine, Iowa. Genetic, common household, and individual environmental effects, pleiotropy, and a direct regression effect of blood pressure on weight are parameterized. The sample consisted of 998 individuals distributed in 261 families of whom 601 were measured on four succe...

  8. Force Lines in Plane Stress

    DEFF Research Database (Denmark)

    Rathkjen, Arne

    A state of plane stress is illustrated by means of two families of curves, each family representing constant values of a derivative of Airy's stress function. The two families of curves form a map giving in the first place an overall picture of regions of high and low stress, and in the second...

  9. Plane and parabolic solar panels

    OpenAIRE

    Sales, J. H. O.; Suzuki, A.T.

    2009-01-01

    We present a plane and parabolic collector that absorbs radiant energy and transforms it in heat. Therefore we have a panel to heat water. We study how to increment this capture of solar beams onto the panel in order to increase its efficiency in heating water.

  10. Assessment of regional left ventricular systolic function of patients with late-stage liver cirrhosis by VSI

    International Nuclear Information System (INIS)

    Objective: To evaluate the regional left ventricular systolic function of patients with late-stage liver cirrhosis by application of vector myocardial strain and strain rate imaging (VSI), and discuss the changes of the regional left ventricular systolic function of patients with late-stage liver cirrhosis. Methods: The longitudinal peak systolic strain rates (L-SRs), radial peak systolic strain rates (R-SRs) and circumferential peak systolic velocity (C-Vs) in 30 patients with late-stage liver cirrhosis (patient group) and 30 cases of age-matched normal persons (control group) were detected by VSI technology. Results: The L-SRs of mid-anteroseptal, apical-anterior and apical-septal in patient group were reduced compared with control group (P<0.05); the R-SRs of mid-anteroseptal, apical-anterior and apical-septal in patient group were reduced compared with control group (P<0.05); the C-Vs of mid-anterior and mid-anteroseptal in the cirrhosis group was reduced compared with control group (P<0.05). Conclusion: The regional left ventricular systolic function of patients with late-stage liver cirrhosis has already reduced before the global left ventricular systolic function has not significantly affected. (authors)

  11. Remote detection of photoplethysmographic systolic and diastolic peaks using a digital camera.

    Science.gov (United States)

    McDuff, Daniel; Gontarek, Sarah; Picard, Rosalind W

    2014-12-01

    We present a new method for measuring photoplethysmogram signals remotely using ambient light and a digital camera that allows for accurate recovery of the waveform morphology (from a distance of 3 m). In particular, we show that the peak-to-peak time between the systolic peak and diastolic peak/inflection can be automatically recovered using the second-order derivative of the remotely measured waveform. We compare measurements from the face with those captured using a contact fingertip sensor and show high agreement in peak and interval timings. Furthermore, we show that results can be significantly improved using orange, green, and cyan color channels compared to the tradition red, green, and blue channel combination. The absolute error in interbeat intervals was 26 ms and the absolute error in mean systolic-diastolic peak-to-peak times was 12 ms. The mean systolic-diastolic peak-to-peak times measured using the contact sensor and the camera were highly correlated, ρ = 0.94 (p 0.001). The results were obtained with a camera frame-rate of only 30 Hz. This technology has significant potential for advancing healthcare. PMID:25073159

  12. Systolic peak detection in acceleration photoplethysmograms measured from emergency responders in tropical conditions.

    Directory of Open Access Journals (Sweden)

    Mohamed Elgendi

    Full Text Available Photoplethysmogram (PPG monitoring is not only essential for critically ill patients in hospitals or at home, but also for those undergoing exercise testing. However, processing PPG signals measured after exercise is challenging, especially if the environment is hot and humid. In this paper, we propose a novel algorithm that can detect systolic peaks under challenging conditions, as in the case of emergency responders in tropical conditions. Accurate systolic-peak detection is an important first step for the analysis of heart rate variability. Algorithms based on local maxima-minima, first-derivative, and slope sum are evaluated, and a new algorithm is introduced to improve the detection rate. With 40 healthy subjects, the new algorithm demonstrates the highest overall detection accuracy (99.84% sensitivity, 99.89% positive predictivity. Existing algorithms, such as Billauer's, Li's and Zong's, have comparable although lower accuracy. However, the proposed algorithm presents an advantage for real-time applications by avoiding human intervention in threshold determination. For best performance, we show that a combination of two event-related moving averages with an offset threshold has an advantage in detecting systolic peaks, even in heat-stressed PPG signals.

  13. Measurements of systolic time intervals using a transoesophageal pulsed echo-Doppler.

    Science.gov (United States)

    Tournadre, J P; Muchada, R; Lansiaux, S; Chassard, D

    1999-10-01

    Measurement of systolic time intervals (STI), an index of left ventricular (LV) systolic function, is usually labour intensive and requires considerable expertise to perform accurately. We have evaluated the accuracy of an automated, continuous and non-invasive STI measurement technique using a descending aortic blood velocity Doppler signal obtained using a transoesophageal echo-Doppler system (TEDS) and an ECG signal. STI were measured in adult pigs using a transoesophageal probe (4 x 4 mm pulsed wave Doppler transducer, 5-MHz frequency and a 3 x 3 mm echo transducer, 10-MHz frequency) associated with an ECG recorder. Measurements were performed at baseline and after injection of esmolol and dobutamine. TEDS data were compared with those obtained by one-line recordings of the electrocardiogram and the central aortic arterial pressure wave. Similar mean values were observed for pre-ejection period (PEPI), LV ejection time (LVET) and PEP/LVET with the two methods. Agreement between the methods (Bland and Altman's test) was excellent with 95% confidence intervals for PEP, LVET and PEP/LVET of -7.17 to +1.37 ms, -12.64 to +0.24 ms and -0.033 to +0.028, respectively. We conclude that the combination of descending aorta blood velocity Doppler and ECG signal is an alternative technique for non-invasive and objective measurement of STI, allowing continuous monitoring of LV systolic function. PMID:10673883

  14. Assessment of systolic and diastolic function in heart failure using ambulatory monitoring with acoustic cardiography.

    Science.gov (United States)

    Dillier, Roger; Zuber, Michel; Arand, Patricia; Erne, Susanne; Erne, Paul

    2011-08-01

    INTRODUCTION. The circadian variation of heart function and heart sounds in patients with and without heart failure (HF) is poorly understood. We hypothesized HF patients would exhibit less circadian variation with worsened cardiac function and sleep apnea. METHODS. We studied 67 HF patients (age 67.4 ± 8.2 years; 42% acute HF) and 63 asymptomatic control subjects with no history of HF (age 61.6 ± 7.7 years). Subjects wore a heart sound/ECG/respiratory monitor. The data were analyzed for sleep apnea, diastolic heart sounds, and systolic time intervals. RESULTS. The HF group had significantly greater prevalence of the third heart sound and prolongation of electro-mechanical activation time, while the control group had an age-related increase in the prevalence of the fourth heart sound. The control group showed more circadian variation in cardiac function. The HF subjects had more sleep apnea and higher occurrence of heart rate non-dipping. CONCLUSIONS. The control subjects demonstrated an increasing incidence of diastolic dysfunction with age, while systolic function was mostly unchanged with aging. Parameters related to systolic function were significantly worse in the HF group with little diurnal variation, indicating a constant stimulation of sympathetic tone in HF and reduction of diurnal regulation. PMID:21361859

  15. Automatic detection of end-diastole and end-systole from echocardiography images using manifold learning

    International Nuclear Information System (INIS)

    The automatic detection of end-diastole and end-systole frames of echocardiography images is the first step for calculation of the ejection fraction, stroke volume and some other features related to heart motion abnormalities. In this paper, the manifold learning algorithm is applied on 2D echocardiography images to find out the relationship between the frames of one cycle of heart motion. By this approach the nonlinear embedded information in sequential images is represented in a two-dimensional manifold by the LLE algorithm and each image is depicted by a point on reconstructed manifold. There are three dense regions on the manifold which correspond to the three phases of cardiac cycle ('isovolumetric contraction', 'isovolumetric relaxation', 'reduced filling'), wherein there is no prominent change in ventricular volume. By the fact that the end-systolic and end-diastolic frames are in isovolumic phases of the cardiac cycle, the dense regions can be used to find these frames. By calculating the distance between consecutive points in the manifold, the isovolumic frames are mapped on the three minimums of the distance diagrams which were used to select the corresponding images. The minimum correlation between these images leads to detection of end-systole and end-diastole frames. The results on six healthy volunteers have been validated by an experienced echo cardiologist and depict the usefulness of the presented method

  16. Comparison of Systolic Blood Pressure Values Obtained by Photoplethysmography and by Korotkoff Sounds

    Directory of Open Access Journals (Sweden)

    Michael Bursztyn

    2013-10-01

    Full Text Available In the current study, a non-invasive technique for systolic blood pressure (SBP measurement based on the detection of photoplethysmographic (PPG pulses during pressure-cuff deflation was compared to sphygmomanometry—the Korotkoff sounds technique. The PPG pulses disappear for cuff-pressures above the SBP value and reappear when the cuff-pressure decreases below the SBP value. One hundred and twenty examinations were performed on forty subjects. In 97 examinations the two methods differed by less than 3 mmHg. In nine examinations the SBP value measured by PPG was higher than that measured by sphygmomanometry by 5 mmHg or more. In only one examination the former was lower by 5 mmHg or more than the latter. The appearance of either the PPG pulses or the Korotkoff sounds assures that the artery under the cuff is open during systolic peak pressure. In the nine examinations mentioned above the PPG pulses were observed while Korotkoff sounds were not detected, despite the open artery during systole. In these examinations, the PPG-based technique was more reliable than sphygmomanometry. The high signal-to-noise ratio of measured PPG pulses indicates that automatic measurement of the SBP by means of automatic detection of the PPG signals is feasible.

  17. Intrinsic Frequency Method for Noninvasive Diagnosis of Left Ventricular Systolic Dysfunction

    Science.gov (United States)

    Pahlevan, Niema; Rinderknecht, Derek; Tavallali, Peyman; Petrasek, Danny; Matthews, Ray; Gharib, Morteza

    2014-11-01

    We have recently developed a new mathematical method, intrinsic frequency (IF) method, that views the left ventricle-arterial system as a coupled dynamic pumping system which is decoupled upon the closure of the aortic valve. Utilizing this method, given an arterial blood pressure waveform we are able to extract two intrinsic frequencies (ω1 and ω2) correlating to systole when the left ventricle (LV) and aorta (vasculature) act as a coupled dynamic pumping system and diastole where the dynamics of the LV is removed. Each of these dynamical pumping states has an inherent frequency of operation (ω1 and ω2) which gives information about LV systolic function (ω1) as well as arterial dynamics (ω2) . IF methodology extracts ω1 and ω2 from the pressure wave. This method was applied to invasive aortic pressure waveforms and noninvasively measured carotid pressure waveforms. Our results shows that ω1 is elevated in patients with LV systolic dysfunction (LVSD). However, ω1 remains relatively constant under healthy conditions as age advances. Our results indicate that IF methodology can be used to detect LVSD from a single pressure waveform. One unique advantage of the IF method is only the shape of the waveform is required. Therefore, ω1 can be easily derived from noninvasive measurements and monitored continuously.

  18. COMPARISON OF ENALAPRIL AND PERINDOPRIL IN PATIENTS WITH ARTERIAL HYPERTENSION AND LEFT VENTRICLE SYSTOLIC DYSFUNCTION

    Directory of Open Access Journals (Sweden)

    Yu. I. Grinshtein

    2010-01-01

    Full Text Available Aim. To compare efficacy of enalapril and perindopril in patients with arterial hypertension (HT and left ventricle systolic dysfunction.Material and methods. Patients (n=51 with HT and left ventricle systolic dysfunction (ejection fraction<45% were included in the prospective open randomized comparative study. Patients were randomized into 2 groups of therapy with enalapril 10-20 mg BID (n=25 or with perindopril 4-8 mg OD (n=26. Hydrochlorothiazide (12,5-25 mg OD was added in case of ineffective therapy. Routine clinical examination, ambulatory blood pressure (BP monitoring, an electrocardiogram, an echocardiography were performed in all patients.Results. The 24-hour and night antihypertensive effect of enalapril was more prominent than this of perindopril. Target BP level was reached in 21 patients (84% of enalapril group and in 20 patients (76,9% of perindopril group. 8 (30,8% patients of perindopril group did not reach night target BP level vs 3 (12% patients of enalapril group. Similar improvement of the left ventricle systolic function was observed in both groups.Conclusion. Enalapril and perindopril demonstrated comparable antihypertensive and cardioprotective effect.

  19. Effect of food intake on left and right ventricular systolic tissue Doppler measurements.

    Science.gov (United States)

    Dieden, Anna; Gårdinger, Ylva; Hlebowicz, Joanna; Björgell, Ola; Dencker, Magnus

    2016-09-01

    Systolic tissue Doppler measurements (s') have been used to measure the velocity in myocardial motion and are a valuable tool for evaluating the systolic function of the left and right ventricles. Digestion of food is known to significantly alter hemodynamics and may therefore affect s'. The effect of food intake on s' parameters has not yet been studied. We assessed whether s' is affected by food intake. Nineteen healthy subjects aged 26·2 ± 4·2 years were investigated. s' was measured with pulsed tissue Doppler imaging in the right and left ventricles before the subjects ate a standardized meal and also 30 and 110 min after the meal. Three measurements were taken in each projection, and a mean value was calculated for each. s' increased significantly (Pfasting to 30 min after food intake in every measured site except in the left inferolateral wall (P = 0·15, NS). Several, but not all, variables returned to base value 110 min after food intake. This study shows that food intake affects the tissue Doppler variables used to evaluate systolic heart function. Further studies are needed in older healthy subjects and older subjects with various cardiovascular diseases. PMID:25976703

  20. Characterization and modeling of annular two-phase flows

    International Nuclear Information System (INIS)

    Three aspects of annular two-phase flow are studied: (a) wave motion on falling films, (b) flow transition from downflow to upflow, and (c) the upflow. For the case of wave motion on falling films, it is shown that the assumption of the Nusselt velocity profile for finite-amplitude waves is solution of the wave profile, wave velocity, and velocity components within the wave is developed. An algorithm based on collocation methods is also detailed and can be applied to extend the model to solve for higher order terms in the velocity profile. Comparisons with experimental studies show good agreement. Flow transition and the upflow experiments are conducted in a 5.08 x 10-2m inner diameter, 6.5m long Plexiglas column. The liquid rates are varied from 0 to 0.126 kg/s and the gas rates from 0 to 0.0524 kg/s. At four measuring stations along the length of the column, an electrical conductance technique which employs two electrodes mounted flush with the wall is utilized to measure film thickness and pressure transducers are used to make the pressure measurements. Flow visualization studies indicate that flooding takes place as a result of entrainment from the crests of large waves. The effect of column length and pore size of the feed device on flooding velocities is studied. No previous correlation or theory is found to be fully adequate. A speculative interaction among system parameters is proposed to form a basis for a physical model for flooding phenomena

  1. Uninstrumented assembly airflow testing in the Annular Flow Distribution facility

    Energy Technology Data Exchange (ETDEWEB)

    Kielpinski, A.L.

    1992-02-01

    During the Emergency Cooling System phase of a postulated large-break loss of coolant accident (ECS-LOCA), air enters the primary loop and is pumped down the reactor assemblies. One of the experiments performed to support the analysis of this accident was the Annular Flow Distribution (AFD) experiment, conducted in a facility built for this purpose at Babcock and Wilcox Alliance Research Center in Alliance, Ohio. As part of this experiment, a large body of airflow data were acquired in a prototypical mockup of the Mark 22 reactor assembly. This assembly was known as the AFD (or the I-AFD here) reference assembly. The I-AFD assembly was fully prototypical, having been manufactured in SRS`s production fabrication facility. Similar Mark 22 mockup assemblies were tested in several test facilities in the SRS Heat Transfer Laboratory (HTL). Discrepancies were found. The present report documents further work done to address the discrepancy in airflow measurements between the AFD facility and HTL facilities. The primary purpose of this report is to disseminate the data from the U-AFD test, and to compare these test results to the I-AFD data and the U-AT data. A summary table of the test data and the B&W data transmittal letter are included as an attachment to this report. The full data transmittal volume from B&W (including time plots of the various instruments) is included as an appendix to this report. These data are further analyzed by comparing them to two other HTL tests, namely, SPRIHTE 1 and the Single Assembly Test Stand (SATS).

  2. Linear Instability of the Plane Couette and Plane Poiseuille Flows

    CERN Document Server

    Chefranov, Sergey G

    2015-01-01

    We show possibility of the Plane Couette (PC) flow instability for Reynolds number Re>Reth=140. This new result of the linear hydrodynamic stability theory is obtained on the base of refusal from the traditionally used assumption on longitudinal periodicity of the disturbances along the direction of the fluid flow. We found that earlier existing understanding on the linear stability of this flow for any arbitrary large Reynolds number is directly related with an assumption on the separation of the variables of the spatial variability for the disturbance field and their periodicity in linear theory of stability. By the refusal from the pointed assumptions also for the Plane Poiseuille (PP) flow, we get a new threshold Reynolds value Reth=1040 that with 4% accuracy agrees with the experiment contrary to more than 500% discrepancy for the earlier known estimate Reth=5772 obtained in the frame of the linear theory but when using the "normal" disturbance form (S. A. Orszag, 1971).

  3. Gravitational Couplings for y-Gop-Planes

    CERN Document Server

    Ospina-Giraldo, J F

    2000-01-01

    The Wess-Zumino action for y deformed and generalized orientifold planes (yGOp-planes) is presented and one power expantion is realized from which processes that involves yGOp-planes, RR-forms, gravitons and gaugeons, are obtained. Finally non-standard yGOp-planes are showed.

  4. Gravitational Couplings for Generalized Orientifold Planes

    CERN Document Server

    Ospina-Giraldo, J F

    2000-01-01

    The Wess-Zumino action for generalized orientifold planes (GOp-planes) is presented and a series power expantion is realized from which processes that involves GOp-planes, RR-forms, gravitons and gaugeons, are obtained. Finally non-standard GOp-planes are showed.

  5. Systolic Blood Pressure, Socioeconomic Status, and Biobehavioral Risk Factors in a Nationally Representative U.S Young Adult Sample

    OpenAIRE

    Brummett, Beverly H.; Babyak, Michael A; Siegler, Ilene C.; Shanahan, Michael; Harris, Kathleen Mullan; Elder, Glen H.; Williams, Redford B.

    2011-01-01

    In the National Longitudinal Study of Adolescent Health, a US longitudinal study of over 15,000 young adults, we examined the extent to which socioeconomic status is linked to systolic blood pressure, and whether biobehavioral risk factors mediate the association. Over 62% of the participants had systolic blood pressure >120 mmHg and 12% with systolic blood pressure >140 mmHg. Over 66% were classified as at least overweight (Body Mass Index>25 kg/m2), with over 36% meeting criteria for at lea...

  6. Optimization of starshades: focal plane versus pupil plane

    Science.gov (United States)

    Flamary, R.; Aime, C.

    2014-09-01

    We search for the best possible transmission for an external occulter coronagraph that is dedicated to the direct observation of terrestrial exoplanets. We show that better observation conditions are obtained when the flux in the focal plane is minimized in the zone in which the exoplanet is observed, instead of for the total flux received by the telescope. We describe the transmission of the occulter as a sum of basis functions. For each element of the basis, we numerically computed the Fresnel diffraction at the aperture of the telescope and the complex amplitude at its focus. The basis functions are circular disks that are linearly apodized over a few centimeters (truncated cones). We complemented the numerical calculation of the Fresnel diffraction for these functions by a comparison with pure circular disks (cylinder) for which an analytical expression, based on a decomposition in Lommel series, is available. The technique of deriving the optimal transmission for a given spectral bandwidth is a classical regularized quadratic minimization of intensities, but linear optimizations can be used as well. Minimizing the integrated intensity on the aperture of the telescope or for selected regions of the focal plane leads to slightly different transmissions for the occulter. For the focal plane optimization, the resulting residual intensity is concentrated behind the geometrical image of the occulter, in a blind region for the observation of an exoplanet, and the level of background residual starlight becomes very low outside this image. Finally, we provide a tolerance analysis for the alignment of the occulter to the telescope, which also favors the focal plane optimization. This means that telescope offsets of a few decimeters do not strongly reduce the efficiency of the occulter.

  7. Aircraft vibration and other factors related to high systolic blood pressure in Indonesian Air Force pilots

    Directory of Open Access Journals (Sweden)

    Minarma Siagian

    2013-05-01

    Full Text Available AbstrakLatar belakang: Penerbangan dapat berdampak pada sistem kardiovaskular manusia. Penerbang terpajan antara lain pada bising dan vibrasi pesawat. Penelitian bertujuan untuk mengetahui pengaruh beberapa faktor penerbangan pada tekanan darah sistolik.Metode: Penelitian nested case-control dilakukan pada penerbang Angkatan Udara Republik Indonesia yang melakukan pemeriksaan fisik tahunan di Lembaga Kesehatan Penerbangan dan Ruang Angkasa (LAKESPRA Saryanto tahun 2003–2008. Data yang diperoleh dari rekam medik berupa umur, jumlah jam terbang, jenis pesawat, kadar glukosa puasa dan kadar kholesterol darah, lingkaran pinggang, tinggi dan berat badan, tinggi badan, serta tekanan darah.Hasil: Dari 336 penerbang, terdapat 16 penerbanga dengan tekanan sistolik ³ 140 mmHg. Penerbang dengan rata-rata jam penerbangan 300-622 jam per tahun dibandingkan dengan 29-299 jam per tahun mempunyai risiko peningkatan tekanan darah sistolik tinggi sebesarf 5 kali [rasio odds suaian (ORa = 5,05, 95% interval kepercayaan (CI = 0,88 -23,30, P = 0,070]. Menurut jam terbang total, mereka yang memiliki 1.401-1,1125 jam dibandingkan 147-1.400 jam berisiko 3,6 kali mengalami tekanan darah sistolik tinggi (ORa = 3,58, 95% CI = 1,24-10,38. Selain itu, mereka dengan denyut nadi istirahat tinggi dibandingkan dengan denyut nadi normal istirahat memiliki 2,4 kali mengalami tekanan darah sistolik tinggi (ORa = 2,37, CI = 0,74-7,50 95, P = 0,147].Kesimpulan: Vibrasi pesawat terbang tinggi, rata-rata jam terbang per tahun tinggi, dan frekuensi nadi istirahat yang tinggi meningkatkan risiko tekanan sistolik tinggi.Kata kunci:tekanan darah sistolik, vibrasi pesawat terbang, frekuensi nadi istirahat, pilotAbstractBackground:Flight may affect the human cardiovascular system. Pilots are exposed among others to aircraft noise and vibration. This study aimed to investigate the effects of aircraft flight on systolic blood pressure.Methods:A nested case-control study was conducted on

  8. The Grushin plane and quasiconformal Jacobians

    OpenAIRE

    Meyerson, William

    2011-01-01

    We construct a quasiconformal map from the Grushin plane to the Euclidean plane. Then, we generalize the Grushin plane slightly and explain how the Grushin plane can serve as an intermediary in dealing with quasiconformal maps on Euclidean spaces. In particular, we construct a family of quasiconformal embeddings of the Euclidean plane into larger Euclidean spaces whose Jacobians fail to be locally integrable on a line.

  9. Mode controlled guided wave tomography using annular array transducers for SHM of water loaded plate like structures

    International Nuclear Information System (INIS)

    Ultrasonic guided wave tomography utilizes an array of permanently mounted transducers to detect and image defects like corrosion, cracks and delamination in structures. It is critical for successful tomography imaging to avoid the influences from external environmental conditions like water loading and changes in temperature. Water loading is particularly challenging as it affects the guided wave propagation in the structure. However, by taking advantage of the physical properties of guided waves it is possible to reduce its effect on the tomography images. Modal points on the dispersion curves can be found that have low out-of-plane displacement in their wave structure and hence no leakage into the liquid on the structure. In this paper, the omnidirectional excitation of desired guided wave modes with annular array transducers is discussed. Guided wave tomography of a steel plate like structure with a corrosion defect is studied under water loading conditions. The influence of water loading is overcome by exciting symmetric guided wave modes (S1) in the structure. Utilizing guided wave mode control it is shown that the defects in the structure can be easily discriminated from any artifacts in the images due to the liquid layer. (paper)

  10. An Experimental Study on 3—D Flow in an Annular Cascade of High Turning Angle Turbine Blades

    Institute of Scientific and Technical Information of China (English)

    WangWensheng; LiangXizhi; 等

    1994-01-01

    This paper presents an experimental study of the three-dimensional turbulent flow fields in a lowspeed annular cascade of high turning angle turbine blades.Detailed measurements were performed on the blade surfaces and mid-streamsurface in the passage and at three axial planes downstream of the cascade by using wall static pressure taps,a five-hole probe and a hot-wire anemometer,The test data include static pressure distribution on blade surfaces,total pressure loss cofeeicient,mean flow velocity components.radial flow angle,turbulence intensity and Reynolds shear stress.Analyses of the three-dimensional cascade flow characteristics were made on the noset location of high loss vortices.the variation of pressure gradient inside the cascade passage and the properties of endwall boundary layers total pressure loss distributions,secondary vortex turbulent dissipation and wake decay downtream of the cascade.These experimental results are valuable for revealing the details of the complex vortex flow structure in modern highly loaded axial turbomachines and validating the three-dimensional flow numerical computation codes.

  11. The general relativistic infinite plane

    CERN Document Server

    Jones, Preston; Ragsdale, Michael; Singleton, Douglas

    2007-01-01

    Uniform fields are one of the simplest and most pedagogically useful examples in introductory courses on electrostatics or Newtonian gravity. In general relativity there have been several proposals as to what constitutes a uniform field. In this article we examine two metrics that can be considered the general relativistic version of the infinite plane with finite mass per unit area. The first metric is the 4D version of the 5D "brane" world models which are the starting point for many current research papers. The second case is the cosmological domain wall metric. We examine to what extent these different metrics match or deviate from our Newtonian intuition about the gravitational field of an infinite plane. These solutions provide the beginning student in general relativity both computational practice and conceptual insight into Einstein's field equations. In addition they do this by introducing the student to material that is at the forefront of current research.

  12. Plane waves as tractor beams

    CERN Document Server

    Forgács, Péter; Romańczukiewicz, Tomasz

    2013-01-01

    It is shown that in a large class of systems plane waves can act as tractor beams: i.e., an incident plane wave can exert a pulling force on the scatterer. The underlying physical mechanism for the pulling force is due to the sufficiently strong scattering of the incoming wave into another mode having a larger wave number, in which case excess momentum is created behind the scatterer. Such a tractor beam or negative radiation pressure effect arises naturally in systems where the coupling between the scattering channels is due to Aharonov-Bohm (AB) gauge potentials. It is demonstrated that this effect is also present if the AB potential is an induced, ("artificial") gauge potential such as the one found in J. March-Russell, J. Preskill, F. Wilczek, Phys. Rev. Lett. 58 2567 (1992).

  13. Time delay controlled annular array transducers for omnidirectional guided wave mode control in plate like structures

    International Nuclear Information System (INIS)

    Guided waves in plate like structures offer several modes with unique characteristics that can be taken advantage for nondestructive inspection applications. Conditions relating to the structure under inspection like the surrounding media, liquid loading, coatings etc require the use of special modes for successful inspection. Therefore, transducers that can excite mode controlled guided waves are essential for defect detection and discrimination in structures. Array transducers with annular elements can generate omnidirectional guided waves in plate like structures. However, the wave modes excited are limited to a particular wavelength governed by the element spacing. This limitation on the annular array transducers can be overcome by controlling the phase at each element relative to one another. In this work, annular array transducer construction techniques are theoretically examined and the optimum phase delays between the annular elements to excite a desired guided wave mode are calculated. A five element comb type annular array transducer is fabricated utilizing 1–3 type piezocomposite material. The mode control capability of the transducer is experimentally verified by selectively exciting the A0 and S0 guided wave modes in an aluminum plate like structure. (paper)

  14. A Parametric Study on the Thermal Hydraulic Design for an Annular Fuel Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Shin, C. H.; Seo, K. W.; Chun, T. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    Recently, MIT proposed an internally and externally cooled annular fuel for an advanced PWR which can endure a substantial power uprating. To apply this annular fuel in the conventional reactors such as OPR-1000, it is desirable to investigate its a structural compatibility for its reloading to operating PWR reactors of OPR-1000 as well as other compatibilities like the fuel to moderator ratio, amount of fissile material and coolant flow area. Conventional fuel assembly has a 16x16 solid rod array with four big guide tubes and one instrumentation tube. A 12x12 annular fuel assembly design which can meet the above compatibilities was proposed, which is structurally compatible with the existing internals of OPR-1000. Actually the advantage of an annular fuel comes from the fuel performance and thermal hydraulics. In the thermal hydraulic analysis, the mixing effect between the neighboring channels has to be carried out in a subchannel analysis. A subchannel analysis code, MATRA has been developed by KAERI. However, MATRA dose not have the capability to model both an internally and externally cooled annular fuel. A subchannel code, MATRA-AF which can be coupled to MATRA and can calculate the coolant flow distribution and heat transfer fraction in the internal and external subchannels has been developed. In this paper, the characteristics and the verification of the MATRA-AF are described. The effects of the thermal hydraulic parameters are estimated through a single fuel assembly.

  15. A Parametric Study on the Thermal Hydraulic Design for an Annular Fuel Assembly

    International Nuclear Information System (INIS)

    Recently, MIT proposed an internally and externally cooled annular fuel for an advanced PWR which can endure a substantial power uprating. To apply this annular fuel in the conventional reactors such as OPR-1000, it is desirable to investigate its a structural compatibility for its reloading to operating PWR reactors of OPR-1000 as well as other compatibilities like the fuel to moderator ratio, amount of fissile material and coolant flow area. Conventional fuel assembly has a 16x16 solid rod array with four big guide tubes and one instrumentation tube. A 12x12 annular fuel assembly design which can meet the above compatibilities was proposed, which is structurally compatible with the existing internals of OPR-1000. Actually the advantage of an annular fuel comes from the fuel performance and thermal hydraulics. In the thermal hydraulic analysis, the mixing effect between the neighboring channels has to be carried out in a subchannel analysis. A subchannel analysis code, MATRA has been developed by KAERI. However, MATRA dose not have the capability to model both an internally and externally cooled annular fuel. A subchannel code, MATRA-AF which can be coupled to MATRA and can calculate the coolant flow distribution and heat transfer fraction in the internal and external subchannels has been developed. In this paper, the characteristics and the verification of the MATRA-AF are described. The effects of the thermal hydraulic parameters are estimated through a single fuel assembly

  16. Ultrasonographic assessment of the proximal digital annular ligament in the equine forelimb

    International Nuclear Information System (INIS)

    Ultrasonography was used with 6 normal cadaver forelimbs of Dutch Warmblood horses to delineate the ultrasonographic anatomy of the palmar pastern region, with emphasis on the proximal digital annular ligament. Using a 5.5 MHz sector scanner, the thin proximal digital annular ligament was not visible on offset sonograms. Only if the digital sheath in the normal limb was distended was the distal border of this ligament outlined. In all normal limbs the palmarodistal thickness of the combined skin-proximal digital annular ligament layer in the mid-pastern region was 2 mm. The flexor tendons and distal sesamoidean ligaments were easily identified as hyperechoic structures. Distension of the digital sheath in the normal limbs clearly outlined the anechoic digital sheath pouches. In 4 lame horses ultrasonography aided the diagnosis of functional proximal digital annular ligament constriction. In all 4 diseased forelimbs ultrasonography demonstrated thickening of the skin-proximal digital annular ligament layer and distension of the digital sheath. In one of these limbs the distended digital sheath was also thickened. The flexor tendons and distal sesamoidean ligaments were normal. There was no radiographic evidence of additional bone or joint lesions

  17. A modified stitching algorithm for testing rotationally symmetric aspherical surfaces with annular sub-apertures

    Science.gov (United States)

    Hou, Xi; Wu, Fan; Yang, Li; Wu, Shi-bin; Chen, Qiang

    2006-02-01

    Annular sub-aperture stitching technique has been developed for low cost and flexible testing rotationally symmetric aspherical surfaces, of which combining accurately the sub-aperture measurement data corrupted by misalignments into a complete surface figure is the key problem. An existed stitching algorithm of annular sub-apertures can convert sub-aperture Zernike coefficients into full-aperture Zernike coefficients, in which use of Zernike circle polynomials represents sub-aperture data over both circle and annular domain. Since Zernike circle polynomials are not orthogonal over annular dominion, the fitting results may give wrong results. In this paper, the Zernike polynomials and existed stitching algorithm have been reviewed, and a modified stitching algorithm with Zernike annular polynomials is provided. The performances of a modified algorithm on the reconstruction precision are studied by comparing with the algorithm existed. The results of computer simulation show that the sub-aperture data reduction with the modified algorithm is more accurate than that obtained with the existed algorithm based on Zernike circle polynomials, and the undergoing matrix manipulation is simpler.

  18. The clinical application of “jetting suture” technique in annular repair under microendoscopic discectomy

    Science.gov (United States)

    Qi, Lei; Li, Mu; Si, Haipeng; Wang, Liang; Jiang, Yunpeng; Zhang, Shuai; Li, Le

    2016-01-01

    Abstract To introduce a new designed suture technique in annular repair under the microendoscopic discectomy (MED) surgery and to evaluate the clinical application of the technique in annular repair under MED with at least 2-year follow-up period. A new method of annular repair was designed and named “jetting suture” technique. Thirty consecutive patients with lumbar disc herniation were enrolled in the prospective single-cohort observational study. Patients were followed up at intervals of preoperative, postoperative 1 week, 3 months, 6 months, 1 year, and last follow-up. The clinical outcomes were evaluated by using Japanese Orthopaedic Association (JOA) score, Oswestry Disability Index, and modified Mcnab criteria. The procedure was successfully performed in all cases. No case required conversion to an open procedure. The mean age of patients was 36.6 years. Average blood loss was 45.8 ± 10.2 mL. The preoperative symptoms were alleviated significantly after surgery. All the standardized measures improved significantly at the last follow-up, including JOA score (10.1 to 26.6; P disc herniation was reported. The designed “jetting suture” technique in annular repair under MED can be performed safely and effectively. It could be a viable alternative to annular repair under lumbar discectomy. PMID:27495101

  19. Repeated mitral valve replacement in a patient with extensive annular calcification

    Directory of Open Access Journals (Sweden)

    Kitamura Tadashi

    2011-11-01

    Full Text Available Abstract Background Mitral valve replacement in the presence of severe annular calcification is a technical challenge. Case report A 47-year-old lady who had undergone mitral and aortic valve replacement for rheumatic disease 27 years before presented with dyspnea. At reoperation, extensive mitral annular calcification was hindering the disc motion of the Starr-Edwards mitral prosthesis. The old prosthesis was removed and a St Jude Medical mechanical valve was implanted after thorough annular debridement. Postoperatively the patient developed paravalvular leak and hemolytic anemia, subsequently undergoing reoperation three days later. The mitral valve was replaced with an Edwards MIRA valve, with a bulkier sewing cuff, after more aggressive annular debridement. Although initially there was no paravalvular leak, it recurred five days later. The patient also developed a small cerebral hemorrhage. As the paravalvular leak and hemolytic anemia gradually worsened, the patient underwent reoperation 14 days later. A Carpentier-Edwards bioprosthetic valve with equine pericardial patches, one to cover the debrided calcified annulus, another as a collar around the prosthesis, was used to eliminate paravalvular leak. At 7 years postoperatively the patient is doing well without any evidence of paravalvular leak or structural valve deterioration. Conclusion Mitral valve replacement using a bioprosthesis with equine pericardial patches was useful to overcome recurrent paravalvular leak due to severe mitral annular calcification.

  20. Numerical modeling of a horizontal annular flow experiment using a droplet entrainment model

    International Nuclear Information System (INIS)

    Highlights: • A new droplet entrainment model within the AIAD framework is proposed. • The approach was validated against a horizontal annular flow experiment. • Important flow phenomena could be calculated and analyzed. - Abstract: One limitation in current simulating horizontal annular flows is the lack of treatment of droplet formation mechanisms. For self-generating annular flows in horizontal pipes, the interfacial momentum exchange and the turbulence parameters have to be modelled correctly. Furthermore the understanding of the mechanism of droplet entrainment in annular flow regimes for heat and mass transfer processes is of great importance in the chemical and nuclear industry. A new entrainment model is proposed. It assumes that due to liquid turbulence the interface gets rough and wavy and forms droplets. The new approach is validated with HZDR annular flow experiments. Important phenomena like the pressure drop, the wave pumping effect, the droplet entrainment, the liquid film formation and the transient flow behavior could be calculated, analyzed and some of the phenomena compared with the measurement

  1. Twisted sectors from plane partitions

    CERN Document Server

    Datta, Shouvik; Li, Wei; Peng, Cheng

    2016-01-01

    Twisted sectors arise naturally in the bosonic higher spin CFTs at their free points, as well as in the associated symmetric orbifolds. We identify the coset representations of the twisted sector states using the description of W_\\infty representations in terms of plane partitions. We confirm these proposals by a microscopic null-vector analysis, and by matching the excitation spectrum of these representations with the orbifold prediction.

  2. Plane SPDC-Quantum Mirror

    OpenAIRE

    Ion, M. L. D.; Ion, D. B.

    2013-01-01

    In this paper the kinematical correlations from the phase conjugated optics (equivalently with crossing symmetric spontaneous parametric down conversion (SPDC) phenomena) in the nonlinear crystals are used for the description of a new kind of optical device called SPDC-quantum mirrors. Then, some important laws of the plane SPDC-quantum mirrors combined with usual mirrors or lens are proved only by using geometric optics concepts. In particular, these results allow us to obtain a new interpre...

  3. Force Lines in Plane Stress

    OpenAIRE

    Rathkjen, Arne

    1994-01-01

    A state of plane stress is illustrated by means of two families of curves, each family representing constant values of a derivative of Airy's stress function. The two families of curves form a map giving in the first place an overall picture of regions of high and low stress, and in the second place, the map comprises a complete graphic representation of the stress at any point.

  4. Air ionization wire plane chamber

    International Nuclear Information System (INIS)

    Radiation Measurement for protection level instrumentation requires large number of detectors. Since the number is large, the detector should be cost effective and yet should have good sensitivity. Gas detectors with presently available microelectronics and signal processing capabilities opened a new era in radiation monitoring. Present paper describes the use of air filled multi anode grid planes as detector for alpha detection. Due to multiple anode wire planes, the charge collection efficiency of the air ionization chamber is higher as compared to conventional ionization chamber. The signal from this Wire Plane Chamber (WPC) has a faster and narrower pulse shape as compared to conventional two-electrode chamber of similar dimensions. The reduction in capacitance also improves the signal to noise ratio so that air can be used as the ionization medium without any special cleaning procedure etc and it may be possible to use even engineering plastic as the structural material for the chamber. The paper gives the results obtained so far with this air ionization chamber. (author)

  5. Echocardiographic assessment of the impact of cardiovascular risk factors on left ventricular systolic function in patients with acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Vijay Kumar Verma

    2014-06-01

    Conclusion: Since the proportion of patients with LV systolic dysfunction in patients with AMI remains relatively high, LV systolic function variables such as LVEF and LVESV should be echocardiographically evaluated in all patients with AMI. Since the post-infarction LV systolic function remains the single most important determinant of survival, treatment of AMI patients should be aimed at limitation of infarct size and prevention of ventricular dilation. Moreover, cardiovascular risk factors such as diabetes mellitus and smoking have a significant impact on the likelihood of impairment of LV systolic function in patients with AMI and hence could influence long-term prognosis. [Int J Res Med Sci 2014; 2(3.000: 1101-1106

  6. Changes in electrocardiographic left ventricular hypertrophy and risk of major cardiovascular events in isolated systolic hypertension: the LIFE study

    DEFF Research Database (Denmark)

    Larstorp, A C K; Okin, P M; Devereux, R B;

    2011-01-01

    The predictive value of changes in the severity of electrocardiographic left ventricular hypertrophy (ECG-LVH) during antihypertensive therapy remains unclear in isolated systolic hypertension (ISH). In a Losartan Intervention For Endpoint reduction in hypertension substudy, we included 1320...

  7. Detection of left ventricular enlargement and impaired systolic function with plasma N-terminal pro brain natriuretic peptide concentrations

    DEFF Research Database (Denmark)

    Grønning, Bjørn Aaris; Nilsson, Jens C.; Søndergaard, Lars;

    2002-01-01

    and magnetic resonance imaging along with 20 age-matched and gender-matched healthy control subjects. RESULTS: NT-proBNPwas associated with LV end-diastolic (r = 0.69; P <.0001) and end-systolic (r = 0.73; P <.0001) volume indices, LV mass index (r = 0.69; P <.0001), and LV ejection fraction (r = -0...... discriminates well between healthy subjects and subjects with impaired LV systolic function or increased LV dimensions...

  8. Enhancing VVER annular proliferation resistance fuel with minor actinides

    International Nuclear Information System (INIS)

    reactivity control of the systems into which they are incorporated. In the study, a typical pressurized water reactor (PWR) VVER-1000 annular fuel unit lattice cell model with UO2 fuel pins will be used to investigate the effectiveness of minor actinide reduction approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance in the intermediate term goal for future nuclear energy systems

  9. Exploring flocculation of suspended burned sediment using an annular flume

    Science.gov (United States)

    Blake, W. H.; Clarke, P.; Manning, A. J.; Fitzsimons, M. F.

    2010-05-01

    The frequency and severity of wildfire events are predicted to increase in many fire-prone areas of the world with implications for erosion, sediment transport and sedimentation. While cohesive suspended sediment is known to be transported primarily as flocculated material in river channels, with important implications for catchment nutrient and contaminant fluxes, there has been little work to date to explore the effect of burning on suspended sediment flocculation processes. Since heating has profound effects on surface soil biogeochemistry, it can be hypothesised that in-channel flocculation processes may also be affected as burned eroded material is transported through the catchment system. Using an annular flume and LISST-ST (Laser in Situ Scatter and Transmissometry with Settling Tube) particle size analyser, short-term suspended sediment flocculation dynamics were examined in burned and unburned sediment collected from a wildfire-impacted catchment, Southern Peloponnese, Greece. Fine sediment (stresses (0.1, 0.3, 0.6 and 0.9 Pa). Experiments were undertaken for a range of suspended sediment concentrations (111, 222 and 333 mg l-1) of burned and unburned material. For each shear and sediment concentration scenario, the flume was operated for 30 minutes to induce a theoretical equilibrium between flocs and fluid shear stress after which 5 replicate subsamples were collected and analysed for effective particle size using the LISST-ST. Material was also analysed for absolute particle size following chemical and ultrasonic dispersion. At the two higher sediment concentrations, the effective particle size distribution of unburned material notably coarsened at shear stresses of 0.1-0.3 Pa in comparison to the absolute particle size distribution. This is reflected in a reduction of the percentage of 250 μm) e.g. from 14.4 ± 4.1 % to 5.9 ± 2.0 % at the highest sediment concentration. While similar increases in effective particle size were seen at the lower

  10. Panoramic Imaging and Holographic Interferometry Using a Panoramic Annular Lens.

    Science.gov (United States)

    Puliparambil, Joseph Thomas

    1992-01-01

    Ideally, a device for making measurements of the inner surface of a cavity should be rugged, compact, and capable of obtaining an unobstructed, complete, and comprehensive image of the cavity space in every direction. The first attempt to patent a system for panoramic imaging was made by Mangin in 1878 and since that time several other devices have been patented. Most of these devices depend on a scanning system or on a complex set of lenses and mirrors and as such they are not very practical for use. However, in 1984 Dr. Pal Greguss invented a simple lens known as a Panoramic Annular Lens (PAL) capable of giving a full 360 degree surround image of the area around the lens. This lens can be utilized along with digital cameras and computer programs to inspect and measure the interior walls of cavities. If a cavity can be regarded as a cylindrical rather than a spherical volume, the image information can be transformed, using stretching methods, onto a flat surface creating a two-dimensional representation of a three-dimensional cylindrical surface. This phenomenon called Flat Cylindrical Perspective (FCP) forms the basis for the image produced by a PAL. To apply standard methods of analysis on an image and also for visual interpretation, image processing algorithms were developed to linearize a PAL image. These programs can be used for endoscopy which is a technique for imaging the inner part of a volume or cavity. Such techniques have applications in the fields of medicine, civil engineering and aerospace; indeed, anywhere tubes and pipes are involved. Holographic interferometry has become an important diagnostic tool in non-destructive testing, but due to lack of panoramic imaging systems this work could not be effectively used for the analysis of cavities. Now, the PAL can be used for panoramic holographic interferometry which can be used to measure submicron deformations of cavity walls caused by small perturbations in temperature, pressured and mechanical loads

  11. Turbulent structure at the midsection of an annular flow

    Science.gov (United States)

    Ghaemi, S.; Rafati, S.; Bizhani, M.; Kuru, E.

    2015-10-01

    The turbulent flow in the midsection of an annular gap between two concentric tubes at Reynolds number of 59 200-90 800 based on hydraulic diameter (dh = 57 mm) and average velocity is experimentally investigated. Measurements are carried out using particle tracking velocimetry (PTV) and planar particle image velocimetry (PIV) with spatial resolution of 0.0068dh (size of the binning window) and 0.0129dh (size of the interrogation window), respectively. Both PTV and PIV results show that the location of maximum mean streamwise velocity (yU) does not coincide with the locations of zero shear stress (yuv), minimum streamwise velocity fluctuation (yu2), and minimum radial velocity fluctuation (yv2). The separation between yU and yuv is 0.013dh based on PTV while PIV underestimates the separation distance as 0.0063dh. Conditional averages of turbulent fluctuations based on the four quadrants across the annulus demonstrate that the inner and outer wall flows overlap in the midsection. In the midsection, the flow is subject to opposing sweep/ejection events originating from both the inner and outer walls. The opposite quadrant events of the two boundary layers cancel out at yuv while the local minimum of spatial correlation of u (maximum mixing of the two wall flows) occurs at yU. Investigation of the budget of Reynolds shear stress showed that production and advection terms act towards the coincidence of the yU and yuv while the dissipation term works against the coincidence of the two points. The location of max also overlaps with zero dissipation of . The production of turbulent kinetic energy is slightly negative in the narrow region between yU and yuv. This negative production acts towards smoothing the mean velocity profile at the joint of the two wall flows by equalizing its curvature (∂2/∂y2) on the two sides of yU. The small separation distance of the yU and yuv is associated with slight deviation from the fully developed condition.

  12. Generalized plane gravitational waves of non-symmetric unified field theories in plane symmetry

    OpenAIRE

    Bhoyar, Sanjiv R.; Ajit Deshmukh

    2012-01-01

    In this paper we investigated the plane wave solutions of both the weak and strong non-symmetric unified field equations of Einstein and Bonner in a generalized plane symmetric space-time in the sense of Taub [Ann. Math. 53, 472 (1951)] for plane gravitational waves. We show that the plane wave solutions of Einstein and Bonner field equations exist in plane symmetry.

  13. Plane wave diffraction by a perfectly transparent half-plane.

    Science.gov (United States)

    Anokhov, Sergey P

    2007-09-01

    The exact solution is found for plane wave diffraction by an arbitrary phase step. The analysis is performed by using the Huygens-Fresnel principle and the superposition integral, where every secondary wave was identified with the surface element field of the actual electromagnetic wave. The dependence of the total field structure on the height of the phase step is analyzed. The formation algorithm is demonstrated for the primary wave component of the edge diffraction, which has a singular nature and determines nearly all physical properties of this phenomenon. PMID:17767219

  14. Effects of terlipressin on systolic pulmonary artery pressure of patients with liver cirrhosis:An echocardiographic assessment

    Institute of Scientific and Technical Information of China (English)

    Engin Altintas; Necdet Akkus; Ramazan Gen; M. Rami Helvaci; Orhan Sezgin; Dilek Oguz

    2004-01-01

    AIM: Portopulmonary hypertension is a serious complication of chronic liver disease. Our aim was to search into the effect of terlipressin on systolic pulmonary artery pressure among cirrhotic patients.METHODS: Twelve patients (6 males and 6 females) with liver cirrhosis were recruited in the study. Arterial blood gas samples were obtained in sitting position at rest. Contrast enhanced echocardiography and measurements of systolic pulmonary artery pressure were performed before and after the intravenous injection of 2 mg terlipressin.RESULTS: Of 12 patients studied, the contrast enhanced echocardiography was positive in 5, and the positive findings in contrast enhanced echocardiography were reversed to normal in two after terlipressin injection. The mean systolic pulmonary artery pressure was 25.5±3.6 mmHg before terlipressin injection, and was 22.5±2.5 mmHg after terlipressin (P=0.003). The systolic pulmonary artery pressure was above 25 mmHg in seven of these 12 patients.After the terlipressin injection, systolic pulmonary artery pressure was <25 mmHg in four of these cases (58.3% vs 25%, P=0.04).CONCLUSION: Terlipressin can decrease the systolic pulmonary artery pressure in patients with liver cirrhosis.

  15. A Study on the Pressure Drop of a Subchannel Analysis Code for an Annular Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Shin, C. H.; Seo, K. W.; In, W. K.; Chun, T. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    Recently, MIT proposed an internally and externally cooled annular fuel for an advanced PWR which can endure a substantial power uprating. KAERI is pursuing the development for its reloading to operating PWR reactors of OPR-1000. Thermal hydraulic analysis is critical part of annular fuel design because it determines dimensions of the fuel within acceptable MNDBR margins. An annular fuel subchannel analysis code, MATRA-AF which can be coupled to MATRA and can calculate the coolant flow split and heat split in the internal and external subchannels has been developed. In this paper, the effects of the parameters related with a calculation of a single-phase and two-phase pressure drop have been estimated.

  16. Hybrid multiphase CFD simulation for liquid-liquid interfacial area prediction in annular centrifugal contactors

    Energy Technology Data Exchange (ETDEWEB)

    Wardle, K.E. [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2013-07-01

    Liquid-liquid contacting equipment used in solvent extraction processes has the dual purpose of mixing and separating two immiscible fluids. Consequently, such devices inherently encompass a wide variety of multiphase flow regimes. A hybrid multiphase computational fluid dynamics (CFD) solver which combines the Eulerian multi-fluid method with VOF (volume of fluid) sharp interface capturing has been developed for application to annular centrifugal contactors. This solver has been extended to enable prediction of mean droplet size and liquid-liquid interfacial area through a single moment population balance method. Simulations of liquid-liquid mixing in a simplified geometry and a model annular centrifugal contactor are reported with droplet breakup/coalescence models being calibrated versus available experimental data. Quantitative comparison is made for two different housing vane geometries and it is found that the predicted droplet size is significantly smaller for vane geometries which result in higher annular liquid holdup.

  17. Tight focus of a radially polarized and amplitude-modulated annular multi-Gaussian beam

    International Nuclear Information System (INIS)

    The focusing of a radially polarized beam without annular apodization ora phase filter at the entrance pupil of the objective results in a wide focus and low purity of the longitudinally polarized component. However, the presence of a physical annular apodization or phase filter makes some applications more difficult or even impossible. We propose a radially polarized and amplitude-modulated annular multi-Gaussian beam mode. Numerical simulation shows that it can be focused into a sharper focal spot of 0.125λ2 without additional apodizations or filters. The beam quality describing the purity of longitudinally polarized component is up to 86%. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  18. Fast Photoacoustic Imaging of Blood Vessels Based on an Annular Transducer Array

    International Nuclear Information System (INIS)

    We present a photoacoustic imaging system for rapid high-resolution photoacoustic imaging of blood vessels based on an annular transducer array. The annular transducer array consists of 256 elements arranged along a 300° arc with a 50-mm radius of curvature, using piezocomposite technology for high sensitivity and high signal-to-noise ratio. An eight-channel data acquisition system is applied to capture the photoacoustic signals using multiplexing and a limited-view filtered back projection algorithm is used to reconstruct the photoacoustic images. The experiments with phantom and blood vessels of a chicken are performed and clear photoacoustic images are obtained. The results demonstrate that the photoacoustic imaging system using the annular transducer array holds the potential application in monitoring neovascularization in tumor angiogenesis

  19. Hybrid multiphase CFD simulation for liquid-liquid interfacial area prediction in annular centrifugal contactors

    International Nuclear Information System (INIS)

    Liquid-liquid contacting equipment used in solvent extraction processes has the dual purpose of mixing and separating two immiscible fluids. Consequently, such devices inherently encompass a wide variety of multiphase flow regimes. A hybrid multiphase computational fluid dynamics (CFD) solver which combines the Eulerian multi-fluid method with VOF (volume of fluid) sharp interface capturing has been developed for application to annular centrifugal contactors. This solver has been extended to enable prediction of mean droplet size and liquid-liquid interfacial area through a single moment population balance method. Simulations of liquid-liquid mixing in a simplified geometry and a model annular centrifugal contactor are reported with droplet breakup/coalescence models being calibrated versus available experimental data. Quantitative comparison is made for two different housing vane geometries and it is found that the predicted droplet size is significantly smaller for vane geometries which result in higher annular liquid holdup

  20. Scintillation characteristics of annular beams propagating through atmospheric turbulence along a slanted path

    International Nuclear Information System (INIS)

    Scintillation characteristics of annular beams propagating through atmospheric turbulence along a slanted path are studied by using the numerical simulation method and some new results are obtained, which are explained in physical terms. It is found that, when the zenith angle is not large enough, the saturation phenomenon of the scintillation index never appears even if the propagation distance is large enough, which is quite different from the behavior for the horizontal propagation case. However, under the same condition (i.e. the zenith angle is not large enough), the on-axis scintillation index still approaches an asymptotical value, which increases as the zenith angle increases, and depends on the obscure ratio of annular beams. Furthermore, the relation of the on-axis scintillation index between annular beams and flat-topped beams is also examined in this paper. It is shown that their relation will change as the zenith angle changes. (paper)

  1. Diametric Tolerance Control of Dual Cooled Annular Fuel Pellet without Inner Surface Grinding

    International Nuclear Information System (INIS)

    A dual cooled fuel consists of internal and external cladding tubes in which annular pellets are stacked and cooling water flows in both internal and external coolant passages. It is recently being reconsidered as a promising option for a power up-rate of a pressurized water reactor fuel assembly because an annular fuel shows a lot of advantages from the point of a fuel safety and its economy due to an increased heat transfer area and a thin pellet thickness. Many technical issues might cause a serious problem to adopt the dual cooled annular fuel to the commercial PWR reactors. One of the most important issues is a heat flux split toward an internal cladding and an external cladding due to the gap conductance asymmetry which results from a preferential expansion of a fuel pellet toward the outside during an irradiation. Gap conductance is directly related to the inner and outer gap thicknesses. Initial gap thicknesses can vary with a pellet's dimensions which are affected by a reactor operation condition. Recently, it is suggested that a fuel rod with a smaller inner gap and a larger outer gap can reduce this gap conductance asymmetry. This approach can be effective only after precise tolerance technology is achieved. Because of an inhomogeneous green density distribution along the compact height, an hour-glassing usually occurred in a sintered cylindrical PWR fuel pellet fabricated by a conventional double-acting press. Thus, a sintered pellet usually undergoes a center-less grinding process in order to secure a pellet's specifications. In the case of an annular pellet fabrication using a conventional double-acting press, the same hour-glass shape would probably occur. The outer diameter tolerance of an annular pellet can be controlled easily similar to that of a conventional cylindrical PWR pellet through a center-less grinding. However, it appears not to be simple in the case of an inner surface grinding. It would be the best way to satisfy the specifications

  2. Anti-oxidative therapy with oral dapsone improved HCV antibody positive annular elastolytic giant cell granuloma.

    Science.gov (United States)

    Igawa, K; Maruyama, R; Katayama, I; Nishioka, K

    1997-05-01

    A 72-year-old fisherman who was positive for the HCV antibody developed an annular, erythematous, infiltrated lesions on sun-exposed areas. The lesions were diagnosed as annular elastolytic giant cell granuloma both clinically and histologically. Topical corticosteroid and cryotherapy with liquid nitrogen for several months failed to improve the lesions. We then started dapsone, a known anti-oxidant, at 50 mg/day. A month later, the margins of the erythematous lesions faded, and the infiltration gradually decreased. No recurrence has been observed for one year after the start of the therapy. Anti-oxidative therapy appears to be effective for annular elastolytic giant cell granuloma and could be an alternate therapy for refractory granulomatous disease. PMID:9198323

  3. Droplet behavior analysis in consideration of droplet entrainment from liquid film in annular dispersed flow

    International Nuclear Information System (INIS)

    A method of droplet behavior simulation in an annular dispersed flow has been developed. In this method, both droplet deposition and entrainment from liquid film are considered. The Lagrangian method and stochastic model are used to analyze droplet diffusion and deposition behavior in a turbulent flow, and droplet entrainment from liquid film is calculated by an entrainment correlation. For the verification of this method, Gill's experiment is analyzed, in which the transition from annular flow with no entrainment to equilibrium annular dispersed flow was observed. Analysis results can also show the similar transition tendency. The experimental results of radial distribution of droplet mass flux are compared with analysis results. The agreement is good for low liquid flow rate, but entrainment rate must be adjusted for high liquid flow rate, in which gas turbulence is thought to be modified by high droplet density. In future work the effect of high droplet density on turbulence should be considered. (author)

  4. Cardiac I123-MIBG Correlates Better than Ejection Fraction with Symptoms Severity in Systolic Heart Failure

    International Nuclear Information System (INIS)

    The association of autonomic activation, left ventricular ejection fraction (LVEF) and heart failure functional class is poorly understood. Our aim was to correlate symptom severity with cardiac sympathetic activity, through iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy and with LVEF in systolic heart failure (HF) patients without previous beta-blocker treatment. Thirty-one patients with systolic HF, class I to IV of the New York Heart Association (NYHA), without previous beta-blocker treatment, were enrolled and submitted to 123I-MIBG scintigraphy and to radionuclide ventriculography for LVEF determination. The early and delayed heart/mediastinum (H/M) ratio and the washout rate (WR) were performed. According with symptom severity, patients were divided into group A, 13 patients in NYHA class I/II, and group B, 18 patients in NYHA class III/IV. Compared with group B patients, group A had a significantly higher LVEF (25% ± 12% in group B vs. 32% ± 7% in group A, p = 0.04). Group B early and delayed H/M ratios were lower than group A ratios (early H/M 1.49 ± 0.15 vs. 1.64 ± 0.14, p = 0.02; delayed H/M 1.39 ± 0.13 vs. 1.58 ± 0.16, p = 0.001, respectively). WR was significantly higher in group B (36% ± 17% vs. 30% ± 12%, p= 0.04). The variable that showed the best correlation with NYHA class was the delayed H/M ratio (r= -0.585; p=0.001), adjusted for age and sex. This study showed that cardiac 123I-MIBG correlates better than ejection fraction with symptom severity in systolic heart failure patients without previous beta-blocker treatment

  5. Systolic reconstruction in patients with low heart rate using coronary dual-source CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Nakashima, Yoshiteru; Shigemoto, Youko; Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Miura, Toshiro; Nao, Tomoko [Department of Cardiology, Yamaguchi University Graduate School of Medicine (Japan); Sano, Yuichi; Narazaki, Akiko [Department of Radiology, Yamaguchi University Hospital (Japan); Kido, Shoji [Computer-aided Diagnosis and Biomedical Imaging Research Biomedical Engineering, Applied Medical Engineering Science Graduate School of Medicine, Yamaguchi University (Japan)

    2011-11-15

    Objectives: The purpose of our study was to determine the relationship between the predictive factors and systolic reconstruction (SR) as an optimal reconstruction window in patients with low heart rate (LHR; less than 65 bpm). Methods: 391 patients (262 male and 129 female, mean age; 67.1 {+-} 10.1 years of age) underwent coronary CTA without the additional administration of a beta-blocker. Affecting factors for SR were analyzed in age, gender, body weight (BW), diabetes mellitus (DM), coronary arterial disease (CAD), ejection fraction (EF), systolic and diastolic body pressure (BP) and heart rate variability (HRV) during coronary CTA. Results: In 29 (7.4%) of the 391 patients, SR was needed, but there was no apparent characteristic difference between the systolic and diastolic reconstruction groups in terms of gender, age, BW, DM, CAD and EF. In a multivariate analysis, the co-existence of DM [P < 0.05; OR, 0.27; 95% CI, 0.092-0.80], diastolic BP [P < 0.01; OR, 0.95; 95% CI, 0.92-0.98] and HRV [P < 0.01; OR, 0.98; 95% CI, 0.96-0.99] were found to be the factors for SR. In gender-related analysis, HRV was an important factor regardless of sex, but co-existence of DM affected especially for female and BP for male. Conclusion: Especially in the patients with LHR who had a medication of DM, high HRV or high BP, SR, in addition to DR, was needed to obtain high-quality coronary CTA images.

  6. Systolic reconstruction in patients with low heart rate using coronary dual-source CT angiography

    International Nuclear Information System (INIS)

    Objectives: The purpose of our study was to determine the relationship between the predictive factors and systolic reconstruction (SR) as an optimal reconstruction window in patients with low heart rate (LHR; less than 65 bpm). Methods: 391 patients (262 male and 129 female, mean age; 67.1 ± 10.1 years of age) underwent coronary CTA without the additional administration of a beta-blocker. Affecting factors for SR were analyzed in age, gender, body weight (BW), diabetes mellitus (DM), coronary arterial disease (CAD), ejection fraction (EF), systolic and diastolic body pressure (BP) and heart rate variability (HRV) during coronary CTA. Results: In 29 (7.4%) of the 391 patients, SR was needed, but there was no apparent characteristic difference between the systolic and diastolic reconstruction groups in terms of gender, age, BW, DM, CAD and EF. In a multivariate analysis, the co-existence of DM [P < 0.05; OR, 0.27; 95% CI, 0.092-0.80], diastolic BP [P < 0.01; OR, 0.95; 95% CI, 0.92-0.98] and HRV [P < 0.01; OR, 0.98; 95% CI, 0.96-0.99] were found to be the factors for SR. In gender-related analysis, HRV was an important factor regardless of sex, but co-existence of DM affected especially for female and BP for male. Conclusion: Especially in the patients with LHR who had a medication of DM, high HRV or high BP, SR, in addition to DR, was needed to obtain high-quality coronary CTA images.

  7. Cardiac I123-MIBG Correlates Better than Ejection Fraction with Symptoms Severity in Systolic Heart Failure

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Sandra M.; Moscavitch, Samuel D.; Carestiato, Larissa R. [Programa de Pós-Graduação em Ciências Cardiovasculares, Hospital Universitário Antonio Pedro, Universidade Federal Fluminense, Rio de Janeiro, RJ (Brazil); Felix, Renata M. [Departamento de Medicina Nuclear, Hospital Pró-Cardíaco, Rio de Janeiro, RJ (Brazil); Rodrigues, Ronaldo C.; Messias, Leandro R. [Programa de Pós-Graduação em Ciências Cardiovasculares, Hospital Universitário Antonio Pedro, Universidade Federal Fluminense, Rio de Janeiro, RJ (Brazil); Azevedo, Jader C. [Programa de Pós-Graduação em Ciências Cardiovasculares, Hospital Universitário Antonio Pedro, Universidade Federal Fluminense, Rio de Janeiro, RJ (Brazil); Departamento de Medicina Nuclear, Hospital Pró-Cardíaco, Rio de Janeiro, RJ (Brazil); Nóbrega, Antonio Cláudio L.; Mesquita, Evandro Tinoco [Programa de Pós-Graduação em Ciências Cardiovasculares, Hospital Universitário Antonio Pedro, Universidade Federal Fluminense, Rio de Janeiro, RJ (Brazil); Mesquita, Claudio Tinoco, E-mail: ctinocom@cardiol.br [Programa de Pós-Graduação em Ciências Cardiovasculares, Hospital Universitário Antonio Pedro, Universidade Federal Fluminense, Rio de Janeiro, RJ (Brazil); Departamento de Medicina Nuclear, Hospital Pró-Cardíaco, Rio de Janeiro, RJ (Brazil)

    2013-07-15

    The association of autonomic activation, left ventricular ejection fraction (LVEF) and heart failure functional class is poorly understood. Our aim was to correlate symptom severity with cardiac sympathetic activity, through iodine-123-metaiodobenzylguanidine ({sup 123}I-MIBG) scintigraphy and with LVEF in systolic heart failure (HF) patients without previous beta-blocker treatment. Thirty-one patients with systolic HF, class I to IV of the New York Heart Association (NYHA), without previous beta-blocker treatment, were enrolled and submitted to {sup 123}I-MIBG scintigraphy and to radionuclide ventriculography for LVEF determination. The early and delayed heart/mediastinum (H/M) ratio and the washout rate (WR) were performed. According with symptom severity, patients were divided into group A, 13 patients in NYHA class I/II, and group B, 18 patients in NYHA class III/IV. Compared with group B patients, group A had a significantly higher LVEF (25% ± 12% in group B vs. 32% ± 7% in group A, p = 0.04). Group B early and delayed H/M ratios were lower than group A ratios (early H/M 1.49 ± 0.15 vs. 1.64 ± 0.14, p = 0.02; delayed H/M 1.39 ± 0.13 vs. 1.58 ± 0.16, p = 0.001, respectively). WR was significantly higher in group B (36% ± 17% vs. 30% ± 12%, p= 0.04). The variable that showed the best correlation with NYHA class was the delayed H/M ratio (r= -0.585; p=0.001), adjusted for age and sex. This study showed that cardiac {sup 123}I-MIBG correlates better than ejection fraction with symptom severity in systolic heart failure patients without previous beta-blocker treatment.

  8. [Atrial filling fraction predicts left ventricular systolic function after myocardial infarction: pre-discharge echocardiographic evaluation].

    Science.gov (United States)

    Galderisi, M; Fakher, A; Petrocelli, A; Alfieri, A; Garofalo, M; de Divitiis, O

    1995-10-01

    Aim of the study was to examine the relation between Doppler-derived indices of left ventricular diastolic and systolic function early after myocardial infarction. Fifty-three patients (31 males, 22 females) recovering from acute myocardial infarction underwent predischarge Doppler echocardiographic examination. Patients with age > 70 years, previous myocardial infarction, more than mild mitral and aortic regurgitation, mitral and aortic stenosis were excluded. Twenty-two healthy subjects (13 males; 9 females) free of coronary risk factors were selected as the control group. Both end-diastolic and end-systolic volumes and ejection fraction were measured by two-dimensional echocardiography. Pulsed Doppler was used to evaluate mitral inflow and left ventricular outflow velocity patterns. The following indices were measured: peak velocity of early (E) and late (A) flows, ratio of E/A peak velocities, ratio of early to late time velocity integrals, atrial filling fraction (time velocity integral A / time velocity integral of flow during total diastole) and deceleration time of E wave for mitral inflow; peak and time-velocity integral for left ventricular outflow. Stroke volume and cardiac output were obtained by pulsed Doppler using the left ventricular outflow method. The two groups were comparable for age, with blood pressure (p volumes were significantly higher (both p volume and cardiac output (both p volumes, atrial filling fraction was an independent predictor of stroke volume, with a direct relation (beta coefficient = 0.53, p volume indicates the importance of atrial contribution to maintain an adequate systolic performance in patients with myocardial infarction. PMID:8819737

  9. Echocardiographic Parameters and Survival in Chagas Heart Disease with Severe Systolic Dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Rassi, Daniela do Carmo, E-mail: dani.rassi@hotmail.com [Faculdade de Medicina e Hospital das Clínicas da Universidade Federal de Goiás (UFG), Goiânia, GO (Brazil); Vieira, Marcelo Luiz Campos [Instituto do Coração da Faculdade de Medicina da Universidade de São Paulo (USP), São Paulo, SP (Brazil); Arruda, Ana Lúcia Martins [Instituto de Radiologia da Faculdade de Medicina da Universidade de São Paulo (USP), São Paulo, SP (Brazil); Hotta, Viviane Tiemi [Instituto do Coração da Faculdade de Medicina da Universidade de São Paulo (USP), São Paulo, SP (Brazil); Furtado, Rogério Gomes; Rassi, Danilo Teixeira; Rassi, Salvador [Faculdade de Medicina e Hospital das Clínicas da Universidade Federal de Goiás (UFG), Goiânia, GO (Brazil)

    2014-03-15

    Echocardiography provides important information on the cardiac evaluation of patients with heart failure. The identification of echocardiographic parameters in severe Chagas heart disease would help implement treatment and assess prognosis. To correlate echocardiographic parameters with the endpoint cardiovascular mortality in patients with ejection fraction < 35%. Study with retrospective analysis of pre-specified echocardiographic parameters prospectively collected from 60 patients included in the Multicenter Randomized Trial of Cell Therapy in Patients with Heart Diseases (Estudo Multicêntrico Randomizado de Terapia Celular em Cardiopatias) - Chagas heart disease arm. The following parameters were collected: left ventricular systolic and diastolic diameters and volumes; ejection fraction; left atrial diameter; left atrial volume; indexed left atrial volume; systolic pulmonary artery pressure; integral of the aortic flow velocity; myocardial performance index; rate of increase of left ventricular pressure; isovolumic relaxation time; E, A, Em, Am and Sm wave velocities; E wave deceleration time; E/A and E/Em ratios; and mitral regurgitation. In the mean 24.18-month follow-up, 27 patients died. The mean ejection fraction was 26.6 ± 5.34%. In the multivariate analysis, the parameters ejection fraction (HR = 1.114; p = 0.3704), indexed left atrial volume (HR = 1.033; p < 0.0001) and E/Em ratio (HR = 0.95; p = 0.1261) were excluded. The indexed left atrial volume was an independent predictor in relation to the endpoint, and values > 70.71 mL/m{sup 2} were associated with a significant increase in mortality (log rank p < 0.0001). The indexed left atrial volume was the only independent predictor of mortality in this population of Chagasic patients with severe systolic dysfunction.

  10. Beat-to-beat systolic time-interval measurement from heart sounds and ECG

    International Nuclear Information System (INIS)

    Systolic time intervals are highly correlated to fundamental cardiac functions. Several studies have shown that these measurements have significant diagnostic and prognostic value in heart failure condition and are adequate for long-term patient follow-up and disease management. In this paper, we investigate the feasibility of using heart sound (HS) to accurately measure the opening and closing moments of the aortic heart valve. These moments are crucial to define the main systolic timings of the heart cycle, i.e. pre-ejection period (PEP) and left ventricular ejection time (LVET). We introduce an algorithm for automatic extraction of PEP and LVET using HS and electrocardiogram. PEP is estimated with a Bayesian approach using the signal's instantaneous amplitude and patient-specific time intervals between atrio-ventricular valve closure and aortic valve opening. As for LVET, since the aortic valve closure corresponds to the start of the S2 HS component, we base LVET estimation on the detection of the S2 onset. A comparative assessment of the main systolic time intervals is performed using synchronous signal acquisitions of the current gold standard in cardiac time-interval measurement, i.e. echocardiography, and HS. The algorithms were evaluated on a healthy population, as well as on a group of subjects with different cardiovascular diseases (CVD). In the healthy group, from a set of 942 heartbeats, the proposed algorithm achieved 7.66 ± 5.92 ms absolute PEP estimation error. For LVET, the absolute estimation error was 11.39 ± 8.98 ms. For the CVD population, 404 beats were used, leading to 11.86 ± 8.30 and 17.51 ± 17.21 ms absolute PEP and LVET errors, respectively. The results achieved in this study suggest that HS can be used to accurately estimate LVET and PEP. (paper)

  11. Safety and Economics of High Power Density PWR with Novel Annular Fuel

    International Nuclear Information System (INIS)

    The internally and externally cooled annular fuel is a new type of fuel for PWRs that enables an increase in core power density by 50% within the same or better safety margins as the traditional solid fuel. Each assembly of traditional side dimensions has 160 annular fuel rods arranged in a 13x13 array. Even at the much higher power density, the fuel exhibits substantially lower temperatures and a MDNBR margin comparable to that of the traditional solid fuel at nominal (100%) power. Safety analyses indicate that the new annular fuel can accommodate 50% power up-rate in a PWR and still maintain adequate safety margins for a variety of transients and accidents including Loss of Flow Accident, Main Steam Line Break, Large Break Loss of Coolant Accident and Rod Ejection Accident. An economic study of 50% up-rate of an existing 1200 MW(e) PWR using the annular fuel shows that: (1) an Internal Rate of Return (IRR) on the order of 20% or more can be expected from such projects, even when accounting for uncertainties in the fuel price, electricity price inflation and cost of equipment; (2) Gradual replacement of the solid core by annular batches prior to up-rating can improve the IRR by 2.3% to 3.5% as it allows to full use of the energy in two already paid for batches of solid fuel rather than discarding them. Mixing of annular and solid fuel assemblies in one core appears feasible due to similar pressure drop characteristics of both assemblies. (authors)

  12. The Long Myocardial Bridging Case Causing Severe Systolic Narrowing; How Should Approach?

    Directory of Open Access Journals (Sweden)

    Süleyman Ercan

    2013-03-01

    Full Text Available Myocardial bridging, characterized in myocardial systolic blood flow is prevented due to compression of a coronary artery segment. This condition detected by coronary angiography is usually accepted benign. A 52 years old man, who had effort angina for three months, has been diagnosed non-critical plaque and long segment myocardial bridging by coronary angiography. We want to share with this case, non-critical plaque together with myocardial bridging caused stable angina and we aimed to approach to patient with myocardial bridging.

  13. Association between coronary flow reserve, left ventricular systolic function, and myocardial viability in acute myocardial infarction

    DEFF Research Database (Denmark)

    Løgstrup, Brian Bridal; Høfsten, Dan E; Christophersen, Thomas B;

    2010-01-01

    AIMS: To investigate the relationships between coronary flow reserve (CFR), left ventricular (LV) systolic function, and myocardial viability in patients with acute myocardial infarction (AMI). METHODS AND RESULTS: In 149 patients with a first AMI, we estimated CFR non-invasively and assessed LV...... patients with CFR 2, P < 0.0001. CONCLUSION: Resting echocardiographic parameters were similar in patient groups. During LDDE, patients with reduced CFR had increased LV size and compromised longitudinal function of LV and were less likely to have evidence of myocardial viability....

  14. Proportional Relations Between Systolic, Diastolic and Mean Pulmonary Artery Pressure are Explained by Vascular Properties

    OpenAIRE

    Kind, Taco; Theo J.C. Faes; Vonk-Noordegraaf, Anton; Westerhof, Nico

    2010-01-01

    Recently, it was shown that proportional relationships exist between systolic, diastolic and mean pulmonary artery pressure (P sys, P dia and P mean) and that they are maintained under various conditions in both health and disease. An arterial-ventricular interaction model was used to study the contribution of model parameters to the ratios P sys/P mean, and P dia/P mean. The heart was modeled by a time-varying elastance function, and the arterial system by a three-element windkessel model co...

  15. Incidence and Predictors of End-Stage Renal Disease in Outpatients With Systolic Heart Failure

    DEFF Research Database (Denmark)

    Bosselmann, Helle Skovmand; Gislason, Gunnar; Gustafsson, Finn;

    2013-01-01

    Background- Renal dysfunction is an important prognostic factor in heart failure (HF), but whether this dysfunction progresses to end-stage renal disease (ESRD) is unknown. Therefore, we examined incidence and predictors of ESRD in outpatients with HF. Methods and Results- Patients with systolic HF...... were identified in The Danish Heart Failure database and new-onset ESRD from the Danish Registry on Dialysis. Renal function was estimated by The Chronic Kidney Disease Epidemiology Collaboration equation and patients grouped by estimated glomerular filtration rate (eGFR)-group I: ≥60 mL/min per 1.73 m...

  16. The Effect of Exercise Training on Diastolic and Systolic Function After Acute Myocardial Infarction

    OpenAIRE

    Fontes-Carvalho, Ricardo; Azevedo, Ana Isabel; Sampaio, Francisco; Teixeira, Madalena; Bettencourt, Nuno; Campos, Lilibeth; Gonçalves, Francisco Rocha; Ribeiro, Vasco Gama; Azevedo, Ana; Leite-Moreira, Adelino

    2015-01-01

    Abstract After acute myocardial infarction (AMI), diastolic dysfunction is frequent and an important determinant of adverse outcome. However, few interventions have proven to be effective in improving diastolic function. We aimed to determine the effect of exercise training on diastolic and systolic function after AMI. One month after AMI, 188 patients were prospectively randomized (1:1) to an 8-week supervised program of endurance and resistance exercise training (n = 86; 55.9 ± 10.8 years) ...

  17. MITRAL ANNULAR CALCIFICATION IN ELDERLY PATIENTS: RELATIONSHIP WITH CLINICAL MANIFESTATIONS AND RISK FACTORS OF CARDIOVASCULAR DISEASES CAUSED BY ATHEROSCLEROSIS

    Directory of Open Access Journals (Sweden)

    G. M. Urvacheva

    2014-07-01

    Full Text Available The aim – to study the association of the mitral annular calcification (MAC with traditional risk factors and clinical manifestations of atherosclerosisin patients aged over 65 years without diabetes.Materials and methods. The prospective study included 100 patients over 65 years with MAC consistently identified among 910 ambulatory patients after transthoracic Doppler echocardiography in relation to the symptoms of cardiovascular disease. The comparison group consisted of 65 consecutively examined patients aged over 65 with no MAC.Results. When comparing risk factors in patients with and without MAC, MAC statistically significant differences was found with age (72,4 ± 5,4 and 70,2 ± 4,3 years, respectively; p = 0,006, the incidence of hypertension of moderate and severe degree (99 % and 90.8 % of patients, p = 0.012, levels of total cholesterol – TC (6,91 ± 0,92 and 6,2 ± 0,90 mmol / l, p = 0.0008 and lipoproteinlow density (3,57 ± 0,95 and 2,96 ± 0,96 mmol / l, p = 0.004 in subgroups of patients aged 65 to 70 years. In multivariate analysis remained statistically significant association of MAC only with age (p = 0,025, β = 0,173 and total cholesterol levels (p = 0,040; β = 0,160. Averages of the coefficient of atherogenicity of blood lipids, systolic and diastolic blood pressure, C-reactive protein, body mass index, waist circumference, the frequency of smoking, and risk assessment on a scale of SCORE in groups of patients with and without MAC did not differ significantly. In patients with MAC was higher incidence of myocardial infarction (p = 0.024 and more often than in patients without MAC, diagnosed coronary heart disease (p = 0.029. In the multivariate analysis adjusted for age and total cholesterol level is set significantly associated with the presence and extent of MAC with symptomatic atherosclerotic peripheral arterial disease (p < 0,00001; β = 0,410.Conclusion. In patients with MAC older than 65 years without diabetes

  18. Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.

  19. An Evaluation of the Annular Fuel and Bottle-Shaped Fuel Concepts for Sodium Fast Reactors

    OpenAIRE

    Memmott, Matthew; Buongiorno, Jacopo; Hejzlar, Pavel

    2010-01-01

    Two innovative fuel concepts, the internally and externally cooled annular fuel and the bottle-shaped fuel, were investigated with the goal of increasing the power density and reduce the pressure drop in the sodium-cooled fast reactor, respectively. The concepts were explored for both high- and low-conversion core configurations, and metal and oxide fuels. The annular fuel concept is best suited for low-conversion metal-fuelled cores, where it can enable a power uprate of ~20%; the magnitude ...

  20. Experimental Study on Convective Boiling Heat Transfer in Vertical Narrow Gap Annular Tube

    Institute of Scientific and Technical Information of China (English)

    Li Bin; He Anding; Wang Yueshe; Zhou Fangde

    2001-01-01

    Experiments are conducted to investigate the characteristics of single-phase forced-flow convection and boiling heat transfer of R113 flowing through annular tube with gap of 1, 1.5 and 2.5 mm, and also the visualization test are carried out to get two-phase flow regime. The data show that the Nusselt numbers for the narrow-gap are higher than those predicted by traditional large channel correlation and boiling heat transfer is enhanced. Based on the data obtained in this investigation, correlations for single-phase, forced convection and flow boiling in annular tube of different gap size has been developed.

  1. Ultrasonography of the trigger fingers: Emphasis on findings of annular pulley

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Hye Won [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2003-06-15

    To analyze the sonographic findings of clinically diagnosed trigger fingers by comparing those of normal fingers with a special emphasis on findings of the annular pulleys that has not been demonstrated previously. Forty-four fingers of 38 patients with clinically diagnosed trigger fingers and 31 asymptomatic contralateral fingers from 29 patients as the normal control group were included in this study. The mean age of the subjects with trigger fingers was 39 years (age range, 7-74 years; female:male = 32:6) while that of the normal control group, 49 years (age range, 7-74 years; female:male = 24:5). Longitudinal and axial images of the flexor digitorum tendons (FDTs) and adjacent soft tissue were obtained with a careful examination of the annular pulleys including A1 pulley. Two radiologists conducted a retrospective analysis of sonographic findings with an emphasis on the visualization and thickness of annular pulleys, thickness and echo pattern of FDTs, distension of tendon sheath , and presence of ganglion. Statistical significances for the difference of thickness of the annular pulleys and FDTs between patients and normal control group were determined with independent sample t-test. The probability value less than .05 was considered statistically significant. Twenty-six of 44 fingers (59%) showed thickened annular pulleys (A1 in 20 and A3 in 6 cases). The thickness of annular pulleys of control and patient groups was 0.27 +- 0.40 mm and 0.77 +- 85 mm, respectively. The average thickness of FDTs of the control and patient groups were 3.35+- 0.77 mm and 3.6 +- 0.9 mm, respectively. The annular pulleys were thickened in the patient group with a statistical significance (p<0.05) whereas the thickness of FDTs did not. The echo pattern of FDTs was normal in 38 fingers of 44 patients (86%) while only six remaining fingers (14%) showed decreased echo and loss of the normal fibrillary pattern within the tendon. Three fingers showed distension of tendon sheath; one

  2. Radially polarized annular beam generated through a second-harmonic-generation process.

    Science.gov (United States)

    Sato, Shunichi; Kozawa, Yuichi

    2009-10-15

    A radially polarized beam with an annular intensity pattern was generated through a second-harmonic-generation process by focusing an azimuthally polarized Ti:sapphire pulsed laser beam to a c-cut beta-barium borate (BBO) crystal. The annular intensity pattern of the second-harmonic wave had a nearly sixfold symmetry as a result of the nonlinear susceptibility tensor of the BBO crystal. The width of the annulus was as narrow as less than 1/40th of its radius. PMID:19838261

  3. DETERMINATION OF TEMPERATURE DISTRIBUTION FOR ANNULAR FINS WITH TEMPERATURE DEPENDENT THERMAL CONDUCTIVITY BY HPM

    Directory of Open Access Journals (Sweden)

    Davood Domairry Ganji

    2011-01-01

    Full Text Available In this paper, homotopy perturbation method has been used to evaluate the temperature distribution of annular fin with temperature-dependent thermal conductivity and to determine the temperature distribution within the fin. This method is useful and practical for solving the nonlinear heat transfer equation, which is associated with variable thermal conductivity condition. The homotopy perturbation method provides an approximate analytical solution in the form of an infinite power series. The annular fin heat transfer rate with temperature-dependent thermal conductivity has been obtained as a function of thermo-geometric fin parameter and the thermal conductivity parameter describing the variation of the thermal conductivity.

  4. Evaluation Performance ofan Annular Composite Fin by UsingMATLAB Programming

    OpenAIRE

    Padma Lochannayak; suvendumohanty

    2015-01-01

    The aim of this project is analysis the efficiency ratio in an annular fin by the variation of heat transfer coefficient for any surface condition by using MATLAB software to calculate the base fin efficiency and the coated fin efficiency by the variation of heat transfer coefficient, radius ratio and base fin thickness of an annular fin and compare the coating fin efficiency to base fin efficiency. If the heat transfer coefficient is 50W/m2K the increase efficiency ratio is 10.46...

  5. CFD Study of an Annular-Ducted Fan Lift System for VTOL Aircraft

    OpenAIRE

    Yun Jiang; Bo Zhang; Tao Huang

    2015-01-01

    The present study aimed at assessing a novel annular-ducted fan lift system for VTOL aircraft through computational fluid dynamics (CFD) simulations. The power and lift efficiency of the lift fan system in hover mode, the lift and drag in transition mode, the drag and flight speed of the aircraft in cruise mode and the pneumatic coupling of the tip turbine and jet exhaust were studied. The results show that the annular-ducted fan lift system can have higher lift efficiency compared to the ro...

  6. Applicability of annular flow model to countercurrent flow in debris beds consisting of large particles

    International Nuclear Information System (INIS)

    Countercurrent flow limitation (CCFL) is the dominant dryout phenomenon in a debris bed that may be formed during a severe accident such as that observed at Three Mile Island unit 2. The actual CCFL situation in a debris bed is very complex, and it is difficult to treat. An annular flow model was developed to predict CCFL in a pipe. If a hypothetical flow channel were assumed, CCFL in a debris bed could be treated in the same manner as CCFL in a pipe. The purpose of this study is to investigate whether the annular flow model developed for CCFL in a pipe is applicable for CCFL in a debris bed

  7. Quasi-static transient thermal stresses in a thick annular disc

    Indian Academy of Sciences (India)

    V S Kulkarni; K C Deshmukh

    2007-10-01

    The present paper deals with the determination of transient thermal stresses in a thick annular disc. A thick annular disc is considered having zero initial temperature and subjected to arbitrary heat flux on the upper and lower surfaces where as the fixed circular edges are at zero temperature.The governing heat conduction equation have been solved by using integral transform technique. The results are obtained in series form in terms of Bessel’s functions. The results for displacement and stresses have been computed numerically and are illustrated graphically

  8. Generation of annular, high-charge electron beams at the Argonne wakefield accelerator

    Science.gov (United States)

    Wisniewski, E. E.; Li, C.; Gai, W.; Power, J.

    2013-01-01

    We present and discuss the results from the experimental generation of high-charge annular(ring-shaped)electron beams at the Argonne Wakefield Accelerator (AWA). These beams were produced by using laser masks to project annular laser profiles of various inner and outer diameters onto the photocathode of an RF gun. The ring beam is accelerated to 15 MeV, then it is imaged by means of solenoid lenses. Transverse profiles are compared for different solenoid settings. Discussion includes a comparison with Parmela simulations, some applications of high-charge ring beams,and an outline of a planned extension of this study.

  9. Plane SPDC-Quantum Mirror

    CERN Document Server

    Ion, M L D

    2013-01-01

    In this paper the kinematical correlations from the phase conjugated optics (equivalently with crossing symmetric spontaneous parametric down conversion (SPDC) phenomena) in the nonlinear crystals are used for the description of a new kind of optical device called SPDC-quantum mirrors. Then, some important laws of the plane SPDC-quantum mirrors combined with usual mirrors or lens are proved only by using geometric optics concepts. In particular, these results allow us to obtain a new interpretation of the recent experiments on the two-photon geometric optics.

  10. Distributed Storage in the Plane

    OpenAIRE

    Altman, Eitan; Avrachenkov, Konstantin; Goseling, Jasper

    2014-01-01

    We consider storage devices located in the plane according to a general point process and specialize the results for the homogeneous Poisson process. A large data file is stored at the storage devices, which have limited storage capabilities. Hence, they can only store parts of the data. Clients can contact the storage devices to retrieve the data.We compare the expected cost of obtaining the complete data under uncoded as well as coded data allocation strategies. It is shown that for the gen...

  11. Semantic versus syntactic cutting planes

    Czech Academy of Sciences Publication Activity Database

    Filmus, Y.; Hrubeš, Pavel; Lauria, M.

    Dagstuhl: Schloss Dagstuhl, Leibniz-Zentrum für Informatik, 2016 - (Ollinger, N.; Vollmer, H.), s. 1-13. (Leibniz International Proceedings in Informatics. 47). ISBN 978-3-95977-001-9. ISSN 1868-8969. [33rd Symposium on Theoretical Aspects of Computer Science (STACS 2016). Orléans (FR), 17.02.2016-20.02.2016] EU Projects: European Commission(XE) 339691 - FEALORA Keywords : proof complexity * cutting planes * lower bounds Subject RIV: BA - General Mathematics http://drops.dagstuhl.de/opus/frontdoor.php?source_opus=5736

  12. Plane waves in noncommutative fluids

    CERN Document Server

    Holender, M C B AbdallaL; Vancea, I V

    2012-01-01

    We study the dynamics of the noncommutative fluid in the Snyder space from the perturbative point of view. To this end, the relevant quantities are treated as series in powers of the noncommutative parameter. At the Planck scale, the relevant terms are of first order and the dynamics is described by a system of coupled linear partial differential equations in which the variables are the fluid density and the fluid potentials. We show that these equations admit a set of solutions that are monocromatic plane waves for the fluid density and two of the potentials and linear for the third potential. The energy-momentum tensor of these solutions is calculated.

  13. SNAP Satellite Focal Plane Development

    International Nuclear Information System (INIS)

    The proposed SuperNova/Acceleration Probe (SNAP) mission will have a two-meter class telescope delivering diffraction-limited images to an instrumented 0.7 square degree field in the visible and near-infrared wavelength regime. The requirements for the instrument suite and the present configuration of the focal plane concept are presented. A two year R and D phase, largely supported by the Department of Energy, is just beginning. We describe the development activities that are taking place to advance our preparedness for mission proposal in the areas of detectors and electronics

  14. Combinatorial geometry in the plane

    CERN Document Server

    Hadwiger, Hugo; Klee, Victor

    2014-01-01

    Geared toward advanced undergraduates familiar with analysis and college geometry, this concise book discusses theorems on topics restricted to the plane such as convexity, coverings, and graphs. In addition to helping students cultivate rigorous thought, the text encourages the development of mathematical intuition and clarifies the nature of mathematical research.The two-part treatment begins with specific topics including integral distances, covering problems, point set geometry and convexity, simple paradoxes involving point sets, and pure combinatorics, among other subjects. The second pa

  15. Constructing a uniform plane-filling path in the ternary heptagrid of the hyperbolic plane

    OpenAIRE

    Maurice Margenstern

    2007-01-01

    In this paper, we distinguish two levels for the plane-filling property. We consider a simple and a strong one. In this paper, we give the construction which proves that the simple plane-filling property also holds for the hyperbolic plane. The plane-filling property was established for the Euclidean plane by J. Kari, see [2], in the strong version. We also give an application of the construction to devise a Peano curve in the hyperbolic plane.

  16. Contact Cohomology of the Projective Plane

    OpenAIRE

    Ernstr{ö}m, Lars; Kennedy, Gary

    1997-01-01

    We construct an associative ring which is a deformation of the quantum cohomology ring of the projective plane. Just as the quantum cohomology encodes the incidence characteristic numbers of rational plane curves, the contact cohomology encodes the tangency characteristic numbers.

  17. On free fermions and plane partitions

    OpenAIRE

    Foda, O.; Wheeler, M.; Zuparic, M.

    2008-01-01

    We use free fermion methods to re-derive a result of Okounkov and Reshetikhin relating charged fermions to random plane partitions, and to extend it to relate neutral fermions to strict plane partitions.

  18. On maps taking lines to plane curves

    OpenAIRE

    Petrushchenko, Vsevolod; Timorin, Vladlen

    2014-01-01

    We study cubic rational maps that take lines to plane curves. A complete description of such cubic rational maps concludes the classification of all planarizations, i.e., maps taking lines to plane curves.

  19. The half plane UIPT is recurrent

    OpenAIRE

    Angel, Omer; Ray, Gourab

    2016-01-01

    We prove that the half plane version of the uniform infinite planar triangulation (UIPT) is recurrent. The key ingredients of the proof are a construction of a new full plane extension of the half plane UIPT, based on a natural decomposition of the half plane UIPT into independent layers, and an extension of previous methods for proving recurrence of weak local limits (still using circle packings).

  20. Aspects of Plane Wave (Matrix) String Dynamics

    OpenAIRE

    Blau, Matthias; O'Loughlin, Martin; Seri, Lorenzo

    2011-01-01

    We analyse two issues that arise in the context of (matrix) string theories in plane wave backgrounds, namely (1) the use of Brinkmann- versus Rosen-variables in the quantum theory for general plane waves (which we settle conclusively in favour of Brinkmann variables), and (2) the regularisation of the quantum dynamics for a certain class of singular plane waves (discussing the benefits and limitations of regularisations of the plane-wave metric itself).

  1. The Bolocam Galactic Plane Survey

    Science.gov (United States)

    Glenn, Jason; Aguirre, James; Bally, John; Battersby, Cara; Bradley, Eric Todd; Cyganowski, Claudia; Dowell, Darren; Drosback, Meredith; Dunham, Miranda K.; Evans, Neal J., II; Ginsburg, Adam; Harvey, Paul; Rosolowsky, Erik; Schlingman, Wayne; Shirley, Yancy L.; Stringfellow, Guy S.; Walawender, Josh; Williams, Jonathan

    2009-01-01

    The Bolocam Galactic Plane Survey (BGPS) is a 1.1 millimeter continuum survey of the northern Galactic Plane made with Bolocam and the Caltech Submillimeter Observatory. The coverage totals 170 square degrees, comprised of a contiguous range from -10.5 deg is less than or equal to 90.5 deg, 0.5 deg is less than or equal to b is less than or equal to 0.5 deg, with extended coverage in b in selected regions, and four targeted regions in the outer Galaxy, including: IC1396, toward the Perseus arm at l is approximately 111 deg, W3/4/5, and Gem OB1. Depths of the maps range from 30 to 60 mJy beam (sup 1). Approximately 8,400 sources were detected and the maps and source catalog have been made publicly available. Millimeter-wave thermal dust emission reveals dense regions within molecular clouds, thus the BGPS serves as a database for studies of the dense interstellar medium and star formation within the Milky Way.

  2. The INTEGRAL Galactic Plane Scanning

    CERN Document Server

    Fiocchi, Mariateresa

    2013-01-01

    After the first nine years of INTEGRAL operational life, the discovery of new sources and source types, a large fraction of which are highly transient or highly absorbed, is certainly one of the most compelling results and legacies of INTEGRAL. Frequent monitoring of the Galactic Plane in AO8 and AO9 campaigns allowed us to detect transient sources, both known and new, confirming that the gamma-ray sky is dominated by the extreme variability of different classes of objects. Regular scans of the Galactic Plane by INTEGRAL provide the most sensitive hard X-ray wide survey to date of our Galaxy, with flux limits of the order of 0.3 mCrab for an exposure time of ~2Ms. Many transient sources have been detected on a wide range of time scales (~hours to months) and identified by triggered followup observations, mainly by Swift/XRT and optical/infrared telescopes. These discoveries are very important to characterize the X-ray binary population in our Galaxy, that is necessary input for evolution studies. The transien...

  3. The UKIDSS Galactic Plane Survey

    CERN Document Server

    Lucas, P W; Longmore, A; Schröder, A C; Davis, C J; Adamson, A; Bandyopadhyay, R M; De Grijs, R; Smith, M; Gosling, A; Mitchison, S; Gaspar, A; Coe, M; Tamura, M; Parker, Q; Irwin, M; Hambly, N; Byant, J; Collins, R S; Cross, N; Evans, D W; Gonzalez-Solares, E; Hodgkin, S; Lewis, J; Read, M; Riello, M; Sutorius, E T W; Lawrence, A; Drew, J E; Dye, S

    2007-01-01

    The UKIDSS Galactic Plane Survey (GPS) is one of the five near infrared Public Legacy Surveys that are being undertaken by the UKIDSS consortium, using the Wide Field Camera on the United Kingdom Infrared Telescope. It is surveying 1868 sq.deg. of the northern and equatorial Galactic plane at Galactic latitudes -5

  4. Quantitative assessment of left ventricular systolic wall thickening using multidetector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, Thomas S. [Department of Radiology, Diagnostic Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: tskaarup@yahoo.com; Kofoed, Klaus F. [Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: kkofoed@dadlnet.dk; Moller, Daniel V. [Department of Cardiology, Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: DVEGA@gmx.net; Ersboll, Mads [Department of Cardiology, Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: ersboell@stud.ku.dk; Kuehl, Tobias [Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: tobiaskh@gmail.com; Recke, Peter von der [Department of Radiology, Diagnostic Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: peter.von.der.recke@rh.regionh.dk; Kober, Lars [Department of Cardiology, Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: lk@heart.dk; Nielsen, Michael B. [Department of Radiology, Diagnostic Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: mbn@dadlnet.dk; Kelbaek, Henning [Department of Cardiology, Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: henning.kelbaek@rh.regionh.dk

    2009-10-15

    Background: Multidetector computed tomography (MDCT) of the heart provides both anatomical and functional information. The objective of this study was to evaluate the accuracy of quantitative assessment of left ventricular contractile function in relation to two-dimensional transthoracic echocardiography (TTE). Materials and methods: Sixty-four patients with known or suspected coronary artery disease underwent ECG-gated 64-slice MDCT and TTE. Regional left ventricular contractile function was measured by percent systolic wall thickening (SWT) in 16 myocardial segments using MDCT, and compared with visual evaluation of wall motion score (WMS) by TTE. Global SWT by MDCT was calculated as the mean SWT of all myocardial segments and compared with wall motion index (WMI) by TTE. Results: Eight hundred and eleven segments (81%) were classified as normokinetic, 142 (14%) as hypokinetic, 41 (4%) as akinetic and 5 (0.5%) as dyskinetic by TTE. A significant inverse linear trend was found between regional SWT by MDCT and WMS by TTE (p < 0.001). Sensitivity and specificity for the identification of regional abnormalities of contractile function were 76% and 78%, respectively. A linear correlation between global SWT by MDCT and WMI by TTE was found (r = -0.8, p < 0.001). Sensitivity and specificity for the identification of WMI > 1.5 using global SWT was 91% and 94%, respectively. Conclusion: Quantification of systolic wall thickening by MDCT provides functional information, which is well correlated to visual assessment of global left ventricular contractile function by TTE.

  5. FPGA-Based Configurable Systolic Architecture for Window-Based Image Processing

    Directory of Open Access Journals (Sweden)

    Miguel Arias-Estrada

    2005-05-01

    Full Text Available Image processing requires more computational power and data throughput than most conventional processors can provide. Designing specific hardware can improve execution time and achieve better performance per unit of silicon area. A field-programmable-gate-array- (FPGA- based configurable systolic architecture specially tailored for real-time window-based image operations is presented in this paper. The architecture is based on a 2D systolic array of 7×7 configurable window processors. The architecture was implemented on an FPGA to execute algorithms with window sizes up to 7×7, but the design is scalable to cover larger window sizes if required. The architecture reaches a throughput of 3.16 GOPs at a 60 MHz clock frequency and a processing time of 8.35 milliseconds for 7×7 generic window-based operators on 512×512 gray-level images. The architecture compares favorably with other architectures in terms of performance and hardware utilization. Theoretical and experimental results are presented to demonstrate the architecture effectiveness.

  6. Cardiac systolic time intervals in fetal monkeys: pre-ejection period.

    Science.gov (United States)

    Murata, Y; Martin, C B; Ikenoue, T; Petrie, R H

    1978-10-01

    The systolic time intervals of the fetal cardiac cycle were studied by means of simultaneous recordings of electrocardiogram (ECG) and ultrasound Doppler cardiogram (DCG) in chronic preparations of fetal rhesus monkeys. Recordings were made under physiologic conditions as well as during various experimental stresses. The pre-ejection period (PEP) showed no significant relationship with heart rate in the unstressed fetuses, but the acceleration of heart rate induced by epinephrine was accompanied by shortening of PEP. The PEP increased with advancing fetal age. The PEP was inversely correlated with left ventricular end-diastolic pressure and arterial pulse pressure, but showed a positive correlation with both systolic and diastolic arterial blood pressure. The PEP also exhibited strong negative correlation with arterial blood pH. the prolongation was essentially the same whether acidosis was of respiratory or metabolic origin. The PEP increased slightly but significantly during nonacidemic hypoxemia; however, there was no correlation between Pao2 and PEP Epinephrine shortened the PEP significantly, whereas the effect of atropine was inconsistent. Alteration of the plasma glucose level by injection of insulin or glucose did not affect PEP. These findings demonstrate that the PEP may be a useful indicator of fetal cardiac performance, reflecting both myocardial contractility and the hemodynamic state of the cardiovascular system. PMID:30282

  7. Non Invasive Measurement of Systolic Blood Pressure in Rats: A Simple Technique

    Directory of Open Access Journals (Sweden)

    Maria Pauline

    2011-10-01

    Full Text Available Background: Non invasive, simple and economical instrument to measure blood pressure in r365-ats is important in cardiovascular research. Methods: Systolic blood pressure measuring instrument was fabricated using a tail cuff, photoplethysmograph, pressure transducer and PC with Biopac Software for recording. Tail cuff was used to occlude the tail artery, photoplethysmograph picked the blood flow pulses in the rat tail and the pressure transducer measured the cuff pressure and converted it into analog voltage. PPG signals were converted into voltage and amplified by the recording system with two channel amplifiers and in addition it also amplified analog voltage converted by the pressure transducer. Results: Calibration of the instrument entailed a simple Bland Altman’s plot of pressure recorded as voltage changes against pressure changes in the mercury sphygmomanometer which is considered as gold standard. A regression value of r=0.9 and p=0.00 was obtained. A pilot study was done on ten female rats. Three blood pressure readings were taken on two occasions. Between - animal variation of BP was 123±7 (mean SD, CV=5.9% and within - animal variation of BP was 120 ±7, CV=5.5%. Conclusion: The tail cuff and PPG based technique to measure systolic blood pressure in rats is simple, economic, accurate and reliable.

  8. Haemodynamic response during low-dose dobutamine infusion in patients with chronic systolic heart failure

    DEFF Research Database (Denmark)

    Egstrup, Michael; Gustafsson, Ida; Andersen, Mads Jønsson; Kistorp, Caroline Michaela; Schou, Morten; Tuxen, Christian Ditlev; Møller, Jacob Eifer

    2013-01-01

    catheterization at rest and during dobutamine infusion at rates of 10 and 20 µg/kg/min. Cardiac output increased from rest to peak dobutamine (4.9 ± 1.2 to 6.6 ± 2.0 L/min, P <0.001) and correlated with the peak systolic tissue velocity (s') at rest (R = 0.61, P = 0.02) and during dobutamine stimulation (R = 0.......2, P = 0.25), E/e' and PCWP only correlated at rest (R = 0.64, P = 0.014). CONCLUSION: The LV systolic shortening velocity is closely associated with cardiac output during LDDE in CHF patients. Dobutamine stimulation increases early diastolic mitral inflow and lengthening velocities, but the E/e' ratio.......79, P <0.001). Increases in early diastolic mitral inflow (E, 74.9 ± 29.0-90.8 ± 29.5 cm/s) and LV lengthening (e', 6.5 ± 2.4-8.2 ± 2.8 cm/s) velocities were observed during LDDE leaving the E/e' ratio unchanged. Although a mean PCWP was also unchanged from rest to peak dobutamine (16.6 ± 8.3-14.2 ± 9...

  9. Identification of phenotypes at risk of transition from diastolic hypertension to isolated systolic hypertension.

    Science.gov (United States)

    Esposito, R; Izzo, R; Galderisi, M; De Marco, M; Stabile, E; Esposito, G; Trimarco, V; Rozza, F; De Luca, N; de Simone, G

    2016-06-01

    Little is known about the potential progression of hypertensive patients towards isolated systolic hypertension (ISH) and about the phenotypes associated with the development of this condition. Aim of this study was to detect predictors of evolution towards ISH in patients with initial systolic-diastolic hypertension. We selected 7801 hypertensive patients free of prevalent cardiovascular (CV) diseases or severe chronic kidney disease and with at least 6-month follow-up from the Campania Salute Network. During 55±44 months of follow-up, incidence of ISH was 21%. Patients with ISH at the follow-up were significantly older (Pwomen (all Pmedia thickness (IMT; all P0.05). Our findings suggest that ISH is a sign of aggravation of the atherosclerotic disease already evident by the target organ damage. Great efforts should be paid to prevent this evolution and prompt aggressive therapy for arterial hypertension should be issued before the onset of target organ damage, to reduce global CV risk. PMID:26355832

  10. Effect of Right Heart Systolic Function on Outcomes in Patients with Constrictive Pericarditis Undergoing Pericardiectomy

    Directory of Open Access Journals (Sweden)

    Xue Lin

    2016-01-01

    Full Text Available Background: To determine the influence of right ventricular function in patients with constrictive pericarditis (CP undergoing surgery and to compare the outcomes of patients who received surgery with those managed medically. Methods: Patients with the diagnosis of CP and healthy volunteers were recruited from January 2006 to November 2011. Patients with CP chose to either receive pericardiectomy or medical management. Echocardiographic measurements were performed to evaluate heart function, and survival was recorded. Results: A total of 58 patients with CP (36 received pericardiectomy, 22 managed medically, and 43 healthy volunteers were included. CP patients who received surgery had a higher survival rate than those managed medically (P = 0.003, and higher survival was also seen in the subgroup of CP patients with severely impaired right systolic function. Albumin level, left ventricular end-diastolic dimension, and tricuspid regurgitation velocity were associated with survival in CP patients who received surgery. Conclusions: Preoperative right heart function does not affect surgical outcomes. Patients with severely impaired preoperative right systolic function obtain a greater survival advantage with surgery than with medical treatment.

  11. Optimization of starshades: focal plane versus pupil plane

    CERN Document Server

    Flamary, Rémi

    2014-01-01

    We search for the best possible transmission for an external occulter coronagraph that is dedicated to the direct observation of terrestrial exoplanets. We show that better observation conditions are obtained when the flux in the focal plane is minimized in the zone in which the exoplanet is observed, instead of the total flux received by the telescope. We describe the transmission of the occulter as a sum of basis functions. For each element of the basis, we numerically computed the Fresnel diffraction at the aperture of the telescope and the complex amplitude at its focus. The basis functions are circular disks that are linearly apodized over a few centimeters (truncated cones). We complemented the numerical calculation of the Fresnel diffraction for these functions by a comparison with pure circular discs (cylinder) for which an analytical expression, based on a decomposition in Lommel series, is available. The technique of deriving the optimal transmission for a given spectral bandwidth is a classical reg...

  12. Counting plane curves of any genus

    OpenAIRE

    Caporaso, Lucia; Harris, Joe

    1996-01-01

    We obtain a recursive formula answering the following question: How many irreducible, plane curves of degree d and (geometric) genus g pass through 3d-1+g general points in the plane? The formula is proved by studying suitable degenerations of plane curves.

  13. The characteristic numbers of quartic plane curves

    OpenAIRE

    Vakil, Ravi

    1998-01-01

    The characteristic numbers of smooth plane quartics are computed using intersection theory on a component of the moduli space of stable maps. This completes the verification of Zeuthen's prediction of characteristic numbers of smooth plane curves. A short sketch of a computation of the characteristic numbers of plane cubics is also given as an illustration.

  14. Monopole Antenna with Modify Ground Plane

    OpenAIRE

    kamal raj singh rajoriya; Singhal, P.K.

    2012-01-01

    This paper presents on modified the ground plane of monopole antenna with varying the shape and length. Basically the length of ground plane of monopole antenna is equal and greater than λ/4. Here analyzed a different ground plane of monopole antenna that is provided an efficient bandwidth with sufficient return loss.

  15. Monopole Antenna with Modify Ground Plane

    Directory of Open Access Journals (Sweden)

    kamal raj singh rajoriya

    2012-06-01

    Full Text Available This paper presents on modified the ground plane of monopole antenna with varying the shape and length. Basically the length of ground plane of monopole antenna is equal and greater than λ/4. Here analyzed a different ground plane of monopole antenna that is provided an efficient bandwidth with sufficient return loss.

  16. Stress Intensity Factor using Finite Element Analysis in Rectangular Orthotropic Composite Annular Disk

    Directory of Open Access Journals (Sweden)

    P. Ravinder Reddy

    1997-01-01

    Full Text Available The quadratic isoparametric elements which embody the inverse squareroot singularity were used to determine the stress intensity factor in an annular disk made of Boron-Epoxy composite material. The displacements and stresses were determined in a rectangular orthotropic composite annular disk using isoparametric finite elements. The singularity in the strain field was provided by means of 8-noded isoparametric elements (4-nodes at the four corners and four mid-side nodes each at l/4th distance from the edge. The results were obtained for various material properties and fibre orientation. The geometry of the annular disk was reported when subjected to a boundary radial and tangential. The r singularity was provided at the boundary of the circular hole and the rest of the annular disk was modelled with ordinary isoparametric elements. The apparent stress intensity factor (K/sub I/= was computed from the stress data near the circular hole, when it was subjected to uniform tension. A curve was drawn for apparent stress intensity factor versus the distance from the crack edge and was extrapolated to r = 0, the actual stress intensity factor was found on the y-axis.

  17. Application of Lubricant to Minimize Axial Deviation of Annular Pellet Diameter

    International Nuclear Information System (INIS)

    In the nuclear industry, the elevation of an economical efficiency for a nuclear fuel is one of the major issues. To increase the efficiency, a development of the nuclear fuel for a high burnup and extended cycle is necessary. In the development of a high performance fuel, in-reactor fuel behavior must be seriously considered. Also, a fuel fabrication and an enrichment process must be discussed. A modification and an improvement of a nuclear fuel system will be also required. The typical fuel geometry of a PWR (Pressurized Water Reactor) is composed of a cylindrical pellet with a tubular cladding. And the outer surface of the cladding is cooled with water. However, to allow for a substantial increase in the power density, an additional cooling is necessary. One of the best ways is the application of a new fuel geometry that is of an annular shape and has both an internal and external cooling. From this point of view, a double cooled fuel is being developed by KAERI (Korea Atomic Energy Research Institute), and as a part of the project, the development of a fabrication process for a UO2 annular pellet is now in progress. In developing the fabrication technology for an annular pellet, there are various methods which can be applied to the fabrication of an annular pellet. But a die pressing method was dominantly chosen, because it is profitable for a production on a large scale

  18. Thermal hydraulic analysis of thorium fuel assemblies loaded with annular seed pins

    International Nuclear Information System (INIS)

    Thermal hydraulic characteristics of thorium-based fuel assemblies loaded with annular seed pins have been analyzed using MATRAA combined with MATRA, and compared with those of the existing thorium-based assemblies. MATRA and MATRAA showed good agreements for the pressure drops at the internal subchannels. The pressure drop generally increased in the cases of the assemblies loaded with annular seed pins due to the larger wetted perimeter, but an exception existed. In the inner subchannels of the seed pins, mass fluxes were high due to the grid form losses in the outer subchannels. About 43% of the heat generated from the seed pin flowed into the inner subchannel and the rest into the outer subchannel, which implies the inner to outer wall heat flux ratio was approximately 1.2. The maximum temperatures of the annular seed pins were slightly above 500 qC. The MDNBRs of the assemblies loaded with annular seed pins were higher than those of the existing assemblies. Due to the fact that interchannel mixing cannot occur in the inner subchannels, temperatures and enthalpies were higher in the inner subchannels

  19. Stress Functions in a Thin Annular Disc Due To Partially Distributed Heat Supply

    Science.gov (United States)

    Bagde, Sunil D.; Khobragade, N. W.

    2012-09-01

    This paper concerned with stress functions in thin annular disc due to partially distributed heat supply to determine the temperature, displacement function and stress functions with the help of finite Fourier cosine transform, Marchi-Zgrablich transform and Laplace transform techniques.

  20. LABORATORY AND NUMERICAL INVESTIGATIONS OF RESIDENCE TIME DISTRIBUTION OF FLUIDS IN LAMINAR FLOW STIRRED ANNULAR PHOTOREACTOR

    Science.gov (United States)

    Laboratory and Numerical Investigations of Residence Time Distribution of Fluids in Laminar Flow Stirred Annular PhotoreactorE. Sahle-Demessie1, Siefu Bekele2, U. R. Pillai11U.S. EPA, National Risk Management Research LaboratorySustainable Technology Division,...