E/e' Ratio: An Index of LV Filling Pressures Revisited
Directory of Open Access Journals (Sweden)
Sherif F. Nagueh
2013-01-01
Full Text Available There is a clinical need for the assessment of cardiac function in patients who present with symptoms and signs of pulmonary and systemic congestion. Echocardiography has been utilized over the years to answer this question. It is possible to study left ventricular (LV systolic and diastolic function as well as pulmonary artery pressures and right ventricular function using this technique. With respect to LV diastolic function, an ideal assessment includes evaluation of LV relaxation and LV filling pressures. There are several parameters that when properly acquired and analyzed can predict the 2 fundamental aspects noted above of LV diastolic function. The mitral annulus early diastolic recoil velocity (e’ recorded by tissue Doppler imaging (TDI was introduced as an index of LV relaxation. Further, e’ velocity is combined with mitral peak velocity E to predict LV filling pressures1. I will discuss the supporting literature for the last statement and point to the limitations in its application.
Choi, Jin-Oh; Daly, Richard C; Lin, Grace; Lahr, Brian D; Wiste, Heather J; Beaver, Thomas M; Iacovoni, Attilio; Malinowski, Marcin; Friedrich, Ivar; Rouleau, Jean L; Favaloro, Roberto R; Sopko, George; Lang, Irene M; White, Harvey D; Milano, Carmelo A; Jones, Robert H; Lee, Kerry L; Velazquez, Eric J; Oh, Jae K
2015-04-01
We sought to evaluate associations between baseline sphericity index (SI) and clinical outcome, and changes in SI after coronary artery bypass graft (CABG) surgery with or without surgical ventricular reconstruction (SVR) in ischaemic cardiomyopathy patients enrolled in the SVR study (Hypothesis 2) of the Surgical Treatment for Ischemic Heart Failure (STICH) trial. Among 1000 patients in the STICH SVR study, we evaluated 546 patients (255 randomized to CABG alone and 291 to CABG + SVR) whose baseline SI values were available. SI was not significantly different between treatment groups at baseline. After 4 months, SI had increased in the CABG + SVR group, but was unchanged in the CABG alone group (0.69 ± 0.10 to 0.77 ± 0.12 vs. 0.67 ± 0.07 to 0.66 ± 0.09, respectively; P < 0.001). SI did not significantly change from 4 months to 2 years in either group. Although LV end-systolic volume and EF improved significantly more in the CABG + SVR group compared with CABG alone, the severity of mitral regurgitation significantly improved only in the CABG alone group, and the estimated LV filling pressure (E/A ratio) increased only in the CABG + SVR group. Higher baseline SI was associated with worse survival after surgery (hazard ratio 1.21, 95% confidence interval 1.02 - 1.43; P = 0.026). Survival was not significantly different by treatment strategy. Although SVR was designed to improve LV geometry, SI worsened after SVR despite improved LVEF and smaller LV volume. Survival was significantly better in patients with lower SI regardless of treatment strategy. © 2015 The Authors. European Journal of Heart Failure © 2015 European Society of Cardiology.
Spherical gradient-index lenses as perfect imaging and maximum power transfer devices.
Gordon, J M
2000-08-01
Gradient-index lenses can be viewed from the perspectives of both imaging and nonimaging optics, that is, in terms of both image fidelity and achievable flux concentration. The simple class of gradient-index lenses with spherical symmetry, often referred to as modified Luneburg lenses, is revisited. An alternative derivation for established solutions is offered; the method of Fermat's strings and the principle of skewness conservation are invoked. Then these nominally perfect imaging devices are examined from the additional vantage point of power transfer, and the degree to which they realize the thermodynamic limit to flux concentration is determined. Finally, the spherical gradient-index lens of the fish eye is considered as a modified Luneburg lens optimized subject to material constraints.
Radiative transfer equation for graded index medium in cylindrical and spherical coordinate systems
International Nuclear Information System (INIS)
Liu, L.H.; Zhang, L.; Tan, H.P.
2006-01-01
In graded index medium, the ray goes along a curved path determined by Fermat principle, and the curved ray-tracing is very difficult and complex. To avoid the complicated and time-consuming computation of curved ray trajectory, the methods not based on ray-tracing technique need to be developed for the solution of radiative transfer in graded index medium. For this purpose, in this paper the streaming operator along a curved ray trajectory in original radiative transfer equation for graded index medium is transformed and expressed in spatial and angular ordinates and the radiative transfer equation for graded index medium in cylindrical and spherical coordinate systems are derived. The conservative and the non-conservative forms of radiative transfer equation for three-dimensional graded index medium are given, which can be used as base equations to develop the numerical simulation methods, such as finite volume method, discrete ordinates method, and finite element method, for radiative transfer in graded index medium in cylindrical and spherical coordinate systems
Acosta, Eva; Vazquez, Daniel; Garner, Leon; Smith, George
2005-03-01
We present an iterative tomographic algorithm to reconstruct refractive-index profiles for meridional planes of the lens of the spherical fish eye from measurements of deflection angles of refracted rays. Numerical simulations show that the algorithm allows accuracy up to the fourth decimal place, provided that the refractive index can be regarded as an analytical function of the radial coordinate and the experimental errors are neglected. An experimental demonstration is given by applying the algorithm to retrieve the refractive-index profile of a spherical fish lens. The method is conceptually simple and does not require matching of the index of the surrounding medium to that of the surface of the lens, and the related iterative algorithm rapidly converges.
Yu, Haitao; Sun, Hui; Shen, Jianqi; Tropea, Cameron
2018-03-01
The primary rainbow observed when light is scattered by a spherical drop has been exploited in the past to measure drop size and relative refractive index. However, if higher spatial resolution is required in denser drop ensembles/sprays, and to avoid then multiple drops simultaneously appearing in the measurement volume, a highly focused beam is desirable, inevitably with a Gaussian intensity profile. The present study examines the primary rainbow pattern resulting when a Gaussian beam is scattered by a spherical drop and estimates the attainable accuracy when extracting size and refractive index. The scattering is computed using generalized Lorenz-Mie theory (GLMT) and Debye series decomposition of the Gaussian beam scattering. The results of these simulations show that the measurement accuracy is dependent on both the beam waist radius and the position of the drop in the beam waist.
Radiative Transfer Equation for Anisotropic Spherical Medium with Specular Reflective Index
International Nuclear Information System (INIS)
Elghazaly, A.
2009-01-01
Radiative transfer problem for anisotropic scattering in a spherical homogeneous, turbid medium with diffuse and angular dependent (specular) reflecting boundaries is solved using the Pomraning-Eddington approximation method. The angular dependent specular reflectivity of the boundary is considered as Fresnel's reflection probability function. The partial heat flux is calculated with anisotropic scattering through a homogeneous solid sphere. The calculations are carried out for spherical media of radii 0.1, 1.0, and 10 mfp and for different scattering albedo. Two different weight functions are used to verify the boundary conditions. Our results are compared with the available data and give an excellent agreement for thick and highly scattering media
International Nuclear Information System (INIS)
Kumari, S. Sindhu; Varadaraj, Kulandaiappan
2014-01-01
Highlights: • Intact AQP0 functions as fiber cell-to-fiber cell adhesion protein. • AQP0 facilitates reduction in extracellular space and lens water content. • AQP0 adhesion function aids in lens refractive index gradient (RING) formation. • AQP0 prevents lens spherical aberration by establishing RING. • AQP0 is critical for lens transparency and homeostasis. - Abstract: Aquaporin 0 (AQP0) is a transmembrane channel that constitutes ∼45% of the total membrane protein of the fiber cells in mammalian lens. It is critical for lens transparency and homeostasis as mutations and knockout cause autosomal dominant lens cataract. AQP0 functions as a water channel and as a cell-to-cell adhesion (CTCA) molecule in the lens. Our recent in vitro studies showed that the CTCA function of AQP0 could be crucial to establish lens refractive index gradient (RING). However, there is a lack of in vivo data to corroborate the role of AQP0 as a fiber CTCA molecule which is critical for creating lens RING. The present investigation is undertaken to gather in vivo evidence for the involvement of AQP0 in developing lens RING. Lenses of wild type (WT) mouse, AQP0 knockout (heterozygous, AQP0 +/− ) and AQP0 knockout lens transgenically expressing AQP1 (heterozygous AQP0 +/− /AQP1 +/− ) mouse models were used for the study. Data on AQP0 protein profile of intact and N- and/or C-terminal cleaved AQP0 in the lens by MALDI-TOF mass spectrometry and SDS–PAGE revealed that outer cortex fiber cells have only intact AQP0 of ∼28 kDa, inner cortical and outer nuclear fiber cells have both intact and cleaved forms, and inner nuclear fiber cells have only cleaved forms (∼26–24 kDa). Knocking out of 50% of AQP0 protein caused light scattering, spherical aberration (SA) and cataract. Restoring the lost fiber cell membrane water permeability (P f ) by transgene AQP1 did not reinstate complete lens transparency and the mouse lenses showed light scattering and SA. Transmission and
Energy Technology Data Exchange (ETDEWEB)
Kumari, S. Sindhu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, New York, NY (United States)
2014-10-03
Highlights: • Intact AQP0 functions as fiber cell-to-fiber cell adhesion protein. • AQP0 facilitates reduction in extracellular space and lens water content. • AQP0 adhesion function aids in lens refractive index gradient (RING) formation. • AQP0 prevents lens spherical aberration by establishing RING. • AQP0 is critical for lens transparency and homeostasis. - Abstract: Aquaporin 0 (AQP0) is a transmembrane channel that constitutes ∼45% of the total membrane protein of the fiber cells in mammalian lens. It is critical for lens transparency and homeostasis as mutations and knockout cause autosomal dominant lens cataract. AQP0 functions as a water channel and as a cell-to-cell adhesion (CTCA) molecule in the lens. Our recent in vitro studies showed that the CTCA function of AQP0 could be crucial to establish lens refractive index gradient (RING). However, there is a lack of in vivo data to corroborate the role of AQP0 as a fiber CTCA molecule which is critical for creating lens RING. The present investigation is undertaken to gather in vivo evidence for the involvement of AQP0 in developing lens RING. Lenses of wild type (WT) mouse, AQP0 knockout (heterozygous, AQP0{sup +/−}) and AQP0 knockout lens transgenically expressing AQP1 (heterozygous AQP0{sup +/−}/AQP1{sup +/−}) mouse models were used for the study. Data on AQP0 protein profile of intact and N- and/or C-terminal cleaved AQP0 in the lens by MALDI-TOF mass spectrometry and SDS–PAGE revealed that outer cortex fiber cells have only intact AQP0 of ∼28 kDa, inner cortical and outer nuclear fiber cells have both intact and cleaved forms, and inner nuclear fiber cells have only cleaved forms (∼26–24 kDa). Knocking out of 50% of AQP0 protein caused light scattering, spherical aberration (SA) and cataract. Restoring the lost fiber cell membrane water permeability (P{sub f}) by transgene AQP1 did not reinstate complete lens transparency and the mouse lenses showed light scattering and SA
Holler, P J; Wess, G
2014-01-01
E-point-to-septal-separation (EPSS) and the sphericity index (SI) are echocardiographic parameters that are recommended in the ESVC-DCM guidelines. However, SI cutoff values to diagnose dilated cardiomyopathy (DCM) have never been evaluated. To establish reference ranges, calculate cutoff values, and assess the clinical value of SI and EPSS to diagnose DCM in Doberman Pinschers. One hundred seventy-nine client-owned Doberman Pinschers. Three groups were formed in this prospective longitudinal study according to established Holter and echocardiographic criteria using the Simpson method of disk (SMOD): control group (97 dogs), DCM with echocardiographic changes (75 dogs) and "last normal" group (n = 7), which included dogs that developed DCM within 1.5 years, but were still normal at this time point. In a substudy, dogs with early DCM based upon SMOD values above the reference range but still normal M-Mode measurements were selected, to evaluate if EPSS or SI were abnormal using the established cutoff values. ROC-curve analysis determined 6.5 mm for EPSS (sensitivity 100%; specificity 99.0%) as optimal cutoff values to diagnose DCM. Both parameters were significantly different between the control group and the DCM group (P < 0.001), but were not abnormal in the "last normal" group. In the substudy, EPSS was abnormal in 13/13 dogs and SI in 2/13 dogs. E-point-to-septal-separation is a valuable additional parameter for the diagnosis of DCM, which can enhance diagnostic capabilities of M-Mode and which performs similar as well as SMOD. Copyright © 2013 by the American College of Veterinary Internal Medicine.
L.V. switchgear - design and development
International Nuclear Information System (INIS)
Armes, D.S.; Brown, R.D.
1992-01-01
This work describes the methods employed in the design and development of L.V. switchgear to meet the prospective conditions and operational requirements imposed on equipment at sites of PWR power stations. The work concentrates on the aspects of design, manufacture, qualification work and quality assurance particular to the range of L.V. switchgear distribution boards manufactured by Laurence, Scott and Electromotors Ltd. for Sizewell B Power Station and contrasts this equipment with other equipment for conventional (i.e. non-nuclear) power station purposes. (Author)
Energy Technology Data Exchange (ETDEWEB)
El Ghazi, Haddou, E-mail: hadghazi@gmail.com [LPS, Faculty of Science, Dhar El Mehrez, BP 1796 Fes-Atlas (Morocco); Special Mathematics, CPGE My Youssef, Rabat (Morocco); Jorio, Anouar [LPS, Faculty of Science, Dhar El Mehrez, BP 1796 Fes-Atlas (Morocco)
2014-10-01
By means of a combination of Quantum Genetic Algorithm and Hartree–Fock–Roothaan method, the changes in linear, third-order nonlinear and total refractive index associated with intra-conduction band transition are investigated with and without shallow-donor impurity in wurtzite (In,Ga)N–GaN spherical quantum dot. For both cases with and without impurity, the calculation is performed within the framework of single band effective-mass and parabolic band approximations. Impurity's position and relaxation time effects are investigated. It is found that the modulation of the refractive index changes, suitable for good performance optical modulators and various infra-red optical device applications can be easily obtained by tailoring the relaxation time and the position of the impurity.
International Nuclear Information System (INIS)
El Ghazi, Haddou; Jorio, Anouar
2014-01-01
By means of a combination of Quantum Genetic Algorithm and Hartree–Fock–Roothaan method, the changes in linear, third-order nonlinear and total refractive index associated with intra-conduction band transition are investigated with and without shallow-donor impurity in wurtzite (In,Ga)N–GaN spherical quantum dot. For both cases with and without impurity, the calculation is performed within the framework of single band effective-mass and parabolic band approximations. Impurity's position and relaxation time effects are investigated. It is found that the modulation of the refractive index changes, suitable for good performance optical modulators and various infra-red optical device applications can be easily obtained by tailoring the relaxation time and the position of the impurity
Protection of LV system against lightning
Yordanova Nedyalkova, Greta
2010-01-01
Lightning is a natural hazard and one of the greatest local mysteries. Scientists have not fully understood the mechanism of lightning. It is one of the most beautiful displays in nature and one of the nature's most dangerous phenomenon known to man. Overvoltage due to lightning is a very important problem of LV systems. Some lightning flashes damage buildings and a few kill or injure people and animals, either directly or indirectly, by causing fire and explosions. The need for protect...
Schneider, M; Hirleman, E D
1994-04-20
A model based on geometric optics for predicting the response of interferometric (phase Doppler) instruments for size measurements of particles with radially symmetric but inhomogeneous internal refractive index profiles is developed. The model and results are important for applications in which heat or mass transfer from the particles or droplets is significant, for example, in liquid-fuel combustion. To quantify the magnitude of potential bias errors introduced by the classical assumption of uniform internal properties on phase Doppler measurements, we compute calibration curves for a sequence of times during the evaporation of a decane droplet immersed in an environment of T = 2000 K and p = 10 bars. The results reveal considerable effects on the relation between phase difference and droplet diameter caused by the refractive index gradients present. The model provides an important tool to assess sizing uncertainties that can be expected when applying conventional (based on uniform properties) phase Doppler calibration curves in spray combustion and similar processes.
Tilapia lake virus (TiLV): Literature review
Jansen, Mona Dverdal; Mohan, Chadag Vishnumurthy
2017-01-01
Tilapia lake virus (TiLV) is an emerging infectious agent that has recently been identified in diseased tilapia on three continents. At the time of writing, scientific publications have reported TiLV in samples collected from Colombia, Ecuador, Egypt, Israel and Thailand. While the link between TiLV and disease outbreaks in Israel and Thailand are well documented, further investigations are being undertaken to determine the significance of TiLV in the other countries. Israel and Taiwan Provin...
Fundamentals of spherical array processing
Rafaely, Boaz
2015-01-01
This book provides a comprehensive introduction to the theory and practice of spherical microphone arrays. It is written for graduate students, researchers and engineers who work with spherical microphone arrays in a wide range of applications. The first two chapters provide the reader with the necessary mathematical and physical background, including an introduction to the spherical Fourier transform and the formulation of plane-wave sound fields in the spherical harmonic domain. The third chapter covers the theory of spatial sampling, employed when selecting the positions of microphones to sample sound pressure functions in space. Subsequent chapters present various spherical array configurations, including the popular rigid-sphere-based configuration. Beamforming (spatial filtering) in the spherical harmonics domain, including axis-symmetric beamforming, and the performance measures of directivity index and white noise gain are introduced, and a range of optimal beamformers for spherical arrays, includi...
Freeden, Willi; Schreiner, Michael
2018-01-01
This book presents, in a consistent and unified overview, results and developments in the field of today´s spherical sampling, particularly arising in mathematical geosciences. Although the book often refers to original contributions, the authors made them accessible to (graduate) students and scientists not only from mathematics but also from geosciences and geoengineering. Building a library of topics in spherical sampling theory it shows how advances in this theory lead to new discoveries in mathematical, geodetic, geophysical as well as other scientific branches like neuro-medicine. A must-to-read for everybody working in the area of spherical sampling.
Cohen, Taco S.; Geiger, Mario; Koehler, Jonas; Welling, Max
2018-01-01
Convolutional Neural Networks (CNNs) have become the method of choice for learning problems involving 2D planar images. However, a number of problems of recent interest have created a demand for models that can analyze spherical images. Examples include omnidirectional vision for drones, robots, and autonomous cars, molecular regression problems, and global weather and climate modelling. A naive application of convolutional networks to a planar projection of the spherical signal is destined t...
Application of MV/LV Transformers with OLTC for Increasing the PV Hosting Capacity Of LV Grids
DEFF Research Database (Denmark)
Hashemi Toghroljerdi, Seyedmostafa; Heckmann, Wolfram; Geibel, Dominik
2015-01-01
The increased use of grid connected photovoltaic (PV) systems in low voltage (LV) grids also raises concern regarding the effects of these new generation units on the grid operation. Overvoltage in LV grids during high PV generation periods is one of the well-known effects caused by PV systems......) and the reactive power absorption by PV inverters, are investigated using field test results and simulations performed on the mentioned LV grid. The results show that the application of OLTC can effectively increase the PV hosting capacity of the grid......., which potentially can decrease the PV hosting capacity of electric grids. This paper presents the applications of medium voltage to low voltage (MV/LV) transformers with on-load tap changers (OLTCs) to prevent overvoltage in high PV penetration conditions. Autonomous methods for controlling...
Czosek, Richard J; Cnota, James F; Knilans, Timothy K; Pratt, Jesse; Guerrier, Karine; Anderson, Jeffrey B
2014-09-01
In attempts to detect diseases that may place adolescents at risk for sudden death, some have advocated for population-based screening. Controversy exists over electrocardiography (ECG) screening due to the lack of specificity, cost, and detrimental effects of false positive or extraneous outcomes. Analyze the relationship between precordial lead voltage on ECG and left ventricle (LV) mass by echocardiogram in adolescent athletes. Retrospective cohort analysis of a prospectively obtained population of self-identified adolescent athletes during sports screening with ECG and echocardiogram. Correlation between ECG LV voltages (R wave in V6 [RV6] and S wave in lead V1 [SV1]) was compared to echocardiogram-based measurements of left ventricular mass. Potential effects on ECG voltages by body anthropometrics, including weight, body mass index (BMI), and body surface area were analyzed, and ECG voltages indexed to BMI were compared to LV mass indices to analyze for improved correlation. A total of 659 adolescents enrolled in this study (64% male). The mean age was 15.4 years (14-18). The correlations between LV mass and RV6, SV1, and RV6 + SV1 were all less than 0.20. The false positive rate for abnormal voltages was relatively high (5.5%) but improved if abnormal voltages in both RV6 and SV1 were mandated simultaneously (0%). Indexing ECG voltages to BMI significantly improved correlation to LV mass, though false positive findings were increased (12.9%). There is poor correlation between ECG precordial voltages and echocardiographic LV mass. This relationship is modified by BMI. This finding may contribute to the poor ECG screening characteristics. ©2014 Wiley Periodicals, Inc.
Telles, J. E.; de Souza, R. E.; Penereiro, J. C.
1990-11-01
RESUMEN. Presentamos fotometria fotografica de 8 objetos y espectrosco- pla para 3 galaxias, las cuales son buenos candidatos para galaxias esfericas. Los resultados fotometricos se presentan en la forma de iso- fotas y de perfiles radiales promedlo, de los cuales se derivan para- metros estructurales. Estas observaciones combinadas con parametros di- namicos obtenidos de observaciones espectrosc6picas, son consistentes con el plano fundamental derivado por Djorgovski y Davis (1987). ABSTRACT. We present photographic surface photometry for 8 objects and spectroscopy for 3 galaxies which are good candidates for spherical galaxies. Photometric results are presented in the form of isophotes and mean radial profiles from which we derived structural parameters. These observations combined with dynamical parameters obtained from spectroscopic observations are consistent with the fundamental plane derived by Djorgovski and Davis (1987). Keq wo : CALAXIES-ELLIPTICAL
Hagy, Jessica
2008-01-01
Jessica Hagy is a different kind of thinker. She has an astonishing talent for visualizing relationships, capturing in pictures what is difficult for most of us to express in words. At indexed.blogspot.com, she posts charts, graphs, and Venn diagrams drawn on index cards that reveal in a simple and intuitive way the large and small truths of modern life. Praised throughout the blogosphere as “brilliant,” “incredibly creative,” and “comic genius,” Jessica turns her incisive, deadpan sense of humor on everything from office politics to relationships to religion. With new material along with some of Jessica’s greatest hits, this utterly unique book will thrill readers who demand humor that makes them both laugh and think.
Formation and characterization of FeLV iscoms.
L. Akerblom; K. Strö mstedt; S. Hö glund; A.D.M.E. Osterhaus (Albert); B. Morein (Bror)
1989-01-01
textabstractImmunostimulating complexes (ISCOMs) have been prepared from feline leukaemia virus (FeLV) envelope proteins. The ISCOMs were characterized biochemically in SDS-polyacrylamide gel electrophoresis showing the presence of proteins of estimated molecular weights of 15,000, 27,000 and
Smart curtailment for congestion management in LV distribution network
Haque, A. N.M.M.; Rahman, M. T.; Nguyen, P. H.; Bliek, F. W.
2016-01-01
The rapid proliferation of distributed energy resources (DERs) leads to capacity challenges, i.e. network congestions, in the low-voltage (LV) distribution networks. A number of strategies are being widely studied to tackle the challenges with direct switching actions such as load shedding or power
Avoided losses on LV networks as a result of microgeneration
Energy Technology Data Exchange (ETDEWEB)
Costa, Paulo Moises [Escola Superior Tecnologia Viseu, Instituto Politecnico Viseu, Campus Politecnico Repeses, 3504-510 Viseu (Portugal); Matos, Manuel A. [INESC Porto, Faculdade de Engenharia da Universidade do Porto, Porto (Portugal)
2009-04-15
In the scope of the discussions about microgeneration (and microgrids), the avoided electrical losses are often pointed out as an important value to be credited to those entities. Therefore, methods to assess the impact of microgeneration on losses must be developed in order to support the definition of a suitable regulatory framework for the economic integration of microgeneration on distribution networks. This paper presents an analytical method to quantify the value of avoided losses that microgeneration may produce on LV networks. Intervals of expected avoided losses are used to account for the variation of avoided losses due to the number, size and location of microgenerators, as well as for the kind of load distribution on LV networks. (author)
A Dynamic and Heuristic Phase Balancing Method for LV Feeders
Directory of Open Access Journals (Sweden)
Samad Taghipour Boroujeni
2016-01-01
Full Text Available Due to the single-phase loads and their stochastic behavior, the current in the distribution feeders is not balanced. In addition, the single-phase loads are located in different positions along the LV feeders. So the amount of the unbalanced load and its location affect the feeder losses. An unbalanced load causes the feeder losses and the voltage drop. Because of time-varying behavior of the single-phase loads, phase balancing is a dynamic and combinatorial problem. In this research, a heuristic and dynamic solution for the phase balancing of the LV feeders is proposed. In this method, it is supposed that the loads’ tie could be connected to all phases through a three-phase switch. The aim of the proposed method is to make the feeder conditions as balanced as possible. The amount and the location of single-phase loads are considered in the proposed phase balancing method. Since the proposed method needs no communication interface or no remote controller, it is inexpensive, simple, practical, and robust. Applying this method provides a distributed and dynamic phase balancing control. In addition, the feasibility of reducing the used switches is investigated. The ability of the proposed method in the phase balancing of the LV feeders is approved by carrying out some simulations.
Directory of Open Access Journals (Sweden)
Caruppannan Ketheswaram
2011-04-01
Full Text Available Abstract Background In patients with severe aortic stenosis (AS, long-term data tracking surgically induced effects of afterload reduction on reverse LV remodeling are not available. Echocardiographic data is available short term, but in limited fashion beyond one year. Cardiovascular MRI (CMR offers the ability to serially track changes in LV metrics with small numbers due to its inherent high spatial resolution and low variability. Hypothesis We hypothesize that changes in LV structure and function following aortic valve replacement (AVR are detectable by CMR and once triggered by AVR, continue for an extended period. Methods Tweny-four patients of which ten (67 ± 12 years, 6 female with severe, but compensated AS underwent CMR pre-AVR, 6 months, 1 year and up to 4 years post-AVR. 3D LV mass index, volumetrics, LV geometry, and EF were measured. Results All patients survived AVR and underwent CMR 4 serial CMR's. LVMI markedly decreased by 6 months (157 ± 42 to 134 ± 32 g/m2, p 2. Similarly, EF increased pre to post-AVR (55 ± 22 to 65 ± 11%,(p 2. LV stroke volume increased rapidly from pre to post-AVR (40 ± 11 to 44 ± 7 ml, p Conclusion After initial beneficial effects imparted by AVR in severe AS patients, there are, as expected, marked improvements in LV reverse remodeling. Via CMR, surgically induced benefits to LV structure and function are durable and, unexpectedly express continued, albeit markedly incomplete improvement through 4 years post-AVR concordant with sustained improved clinical status. This supports down-regulation of both mRNA and MMP activity acutely with robust suppression long term.
Role of HIV-2 envelope in Lv2-mediated restriction
International Nuclear Information System (INIS)
Reuter, Sandra; Kaumanns, Patrick; Buschhorn, Sabine B.; Dittmar, Matthias T.
2005-01-01
We have characterized envelope protein pseudotyped HIV-2 particles derived from two HIV-2 isolates termed prCBL23 and CBL23 in order to define the role of the envelope protein for the Lv2-mediated restriction to infection. Previously, it has been described that the primary isolate prCBL23 is restricted to infection of several human cell types, whereas the T cell line adapted isolate CBL23 is not restricted in these cell types. Molecular cloning of the two isolates revealed that the env and the gag gene are responsible for the observed phenotype and that this restriction is mediated by Lv2, which is distinct from Ref1/Lv1 (Schmitz, C., Marchant, D., Neil, S.J., Aubin, K., Reuter, S., Dittmar, M.T., McKnight, A., Kizhatil, K., Albritton, L.M., 2004. Lv2, a novel postentry restriction, is mediated by both capsid and envelope. J. Virol. 78 (4), 2006-2016). We generated pseudotyped viruses consisting of HIV-2 (ROD-AΔenv-GFP, ROD-AΔenv-RFP, or ROD-AΔenv-REN) and the prCBL23 or CBL23 envelope proteins as well as chimeric proteins between these envelopes. We demonstrate that a single amino acid exchange at position 74 in the surface unit of CBL23-Env confers restriction to infection. This single point mutation causes tighter CD4 binding, resulting in a less efficient fusion into the cytosol of the restricted cell line. Prevention of endosome formation and prevention of endosome acidification enhance infectivity of the restricted particles for GHOST/X4 cells indicating a degradative lysosomal pathway as a cause for the reduced cytosolic entry. The described restriction to infection of the primary isolate prCBL23 is therefore largely caused by an entry defect. A remaining restriction to infection (19-fold) is preserved when endosomal acidification is prevented. This restriction to infection is also dependent on the presence of the point mutation at position 74 (G74E)
Schlecht-Louf, Géraldine; Mangeney, Marianne; El-Garch, Hanane; Lacombe, Valérie; Poulet, Hervé; Heidmann, Thierry
2014-01-01
We previously delineated a highly conserved immunosuppressive (IS) domain within murine and primate retroviral envelope proteins that is critical for virus propagation in vivo. The envelope-mediated immunosuppression was assessed by the ability of the proteins, when expressed by allogeneic tumor cells normally rejected by engrafted mice, to allow these cells to escape, at least transiently, immune rejection. Using this approach, we identified key residues whose mutation (i) specifically abolishes immunosuppressive activity without affecting the "mechanical" function of the envelope protein and (ii) significantly enhances humoral and cellular immune responses elicited against the virus. The objective of this work was to study the immunosuppressive activity of the envelope protein (p15E) of feline leukemia virus (FeLV) and evaluate the effect of its abolition on the efficacy of a vaccine against FeLV. Here we demonstrate that the FeLV envelope protein is immunosuppressive in vivo and that this immunosuppressive activity can be "switched off" by targeted mutation of a specific amino acid. As a result of the introduction of the mutated envelope sequence into a previously well characterized canarypox virus-vectored vaccine (ALVAC-FeLV), the frequency of vaccine-induced FeLV-specific gamma interferon (IFN-γ)-producing cells was increased, whereas conversely, the frequency of vaccine-induced FeLV-specific interleukin-10 (IL-10)-producing cells was reduced. This shift in the IFN-γ/IL-10 response was associated with a higher efficacy of ALVAC-FeLV against FeLV infection. This study demonstrates that FeLV p15E is immunosuppressive in vivo, that the immunosuppressive domain of p15E can modulate the FeLV-specific immune response, and that the efficacy of FeLV vaccines can be enhanced by inhibiting the immunosuppressive activity of the IS domain through an appropriate mutation.
Patel, M; Carritt, K; Lane, J; Jayappa, H; Stahl, M; Bourgeois, M
2015-07-01
Four vaccines for feline leukemia virus (FeLV) are available in the United States. This study's purpose was to compare the efficacy of Nobivac feline 2-FeLV (an inactivated, adjuvanted whole-virus vaccine) and PureVax recombinant FeLV (a live, canarypox virus-vectored vaccine) following FeLV challenge. Cats were vaccinated at 9 and 12 weeks with Nobivac feline 2-FeLV (group A, n = 11) or PureVax recombinant FeLV (group B, n = 10). Group C (n = 11) comprised unvaccinated controls. At 3 months postvaccination, cats were immunosuppressed and challenged with FeLV-A/61E. The outcomes measured were persistent antigenemia at 12 weeks postchallenge (PC) and proviral DNA and viral RNA at 3 to 9 weeks PC. Persistent antigenemia was observed in 0 of 11 cats in group A, 5 of 10 cats in group B, and 10 of 11 cats in group C. Group A was significantly protected compared to those in groups B (P 0.063). The preventable fraction was 100% for group A and 45% for group B. At 9 weeks PC, proviral DNA and viral RNA were detected 1 of 11 cats in group A, 6 of 10 cats in group B, and 9 of 11 cats in group C. Nucleic acid loads were significantly lower in group A than in group C (P feline 2-FeLV-vaccinated cats were fully protected against persistent antigenemia and had significantly smaller amounts of proviral DNA and plasma viral RNA loads than PureVax recombinant FeLV-vaccinated cats and unvaccinated controls. Copyright © 2015, Patel et al.
Pat, Betty; Killingsworth, Cheryl; Chen, Yuanwen; Gladden, James D; Walcott, Greg; Powell, Pamela C; Denney, Thomas; Gupta, Himanshu; Desai, Ravi; Tillson, Michael; Dillon, A Ray; Dell'italia, Louis J
2010-09-01
Mast cells are increased in isolated mitral regurgitation (MR) in the dog and may mediate extracellular matrix loss and left ventricular (LV) dilatation. We tested the hypothesis that mast cell stabilization would attenuate LV remodeling and improve function in the MR dog. MR was induced in adult dogs randomized to no treatment (MR, n = 5) or to the mast cell stabilizer, ketotifen (MR + MCS, n = 4) for 4 months. LV hemodynamics were obtained at baseline and after 4 months of MR and magnetic resonance imaging (MRI) was performed at sacrifice. MRI-derived, serial, short-axis LV end-diastolic (ED) and end-systolic (ES) volumes, LVED volume/mass ratio, and LV 3-dimensional radius/wall thickness were increased in MR and MR + MCS dogs compared with normal dogs (n = 6) (P < .05). Interstitial collagen was decreased by 30% in both MR and MR + MCS versus normal dogs (P < .05). LV contractility by LV maximum time-varying elastance was significantly depressed in MR and MR + MCS dogs. Furthermore, cardiomyocyte fractional shortening was decreased in MR versus normal dogs and further depressed in MR + MCS dogs (P < .05). In vitro administration of ketotifen to normal cardiomyocytes also significantly decreased fractional shortening and calcium transients. Chronic mast cell stabilization did not attenuate eccentric LV remodeling or collagen loss in MR. However, MCS therapy had a detrimental effect on LV function because of a direct negative inotropic effect on cardiomyocyte function. Published by Elsevier Inc.
Are Nanoparticles Spherical or Quasi-Spherical?
Sokolov, Stanislav V; Batchelor-McAuley, Christopher; Tschulik, Kristina; Fletcher, Stephen; Compton, Richard G
2015-07-20
The geometry of quasi-spherical nanoparticles is investigated. The combination of SEM imaging and electrochemical nano-impact experiments is demonstrated to allow sizing and characterization of the geometry of single silver nanoparticles. © 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.
Leung, Ka-Ngo
2006-11-21
A spherical neutron generator is formed with a small spherical target and a spherical shell RF-driven plasma ion source surrounding the target. A deuterium (or deuterium and tritium) ion plasma is produced by RF excitation in the plasma ion source using an RF antenna. The plasma generation region is a spherical shell between an outer chamber and an inner extraction electrode. A spherical neutron generating target is at the center of the chamber and is biased negatively with respect to the extraction electrode which contains many holes. Ions passing through the holes in the extraction electrode are focused onto the target which produces neutrons by D-D or D-T reactions.
Energy levels, lifetimes and radiative data of W LV
Ding, Xiao-bin; Sun, Rui; Koike, Fumihiro; Murakami, Izumi; Kato, Daiji; Sakaue, Hiroyuki A.; Nakamura, Nobuyuki; Dong, Chen-zhong
2018-01-01
Calculations of energy levels, radiative data and lifetimes are reported for tungsten Ca-like ion (W LV) by using multi-configuration Dirac-Fock (MCDF) method. The GRASP2K package is adopted to carry out a large-scale systematic computation with a restricted active space treatment; the Breit interaction and QED effects are included in subsequent relativistic configuration interaction calculations. The energies and lifetimes of the lowest 119 levels are listed; the main leading configuration of the levels is of the ground state configuration [Ne]3s23p63d2 and the first excited configuration [Ne]3s23p53d3. The wavelengths, radiative rates and oscillator strengths for relatively strong E1, E2, M1, and M2 transitions are listed. Comparisons with earlier experimental and theoretical values are made. The average relative deviations of energy levels from the NIST results and E1 transition wavelengths from the EBIT experimental results have turned to be only 0.20% and 0.13%, respectively. The other present results are in reasonable agreement with available data. These agreements confirm the reliability and accuracy of the current results. The present datasets may help us with the investigation of the electron-electron correlation effects in complex multi-electron highly charged heavy ions and of the diagnosis of tungsten impurity plasmas in fusion science.
Energy Technology Data Exchange (ETDEWEB)
Glissmeyer, John A.; Antonio, Ernest J.; Flaherty, Julia E.; Amidan, Brett G.
2014-09-30
This document reports on a series of tests conducted to assess the proposed air sampling locations for the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Group 1-2A exhaust stacks with respect to the applicable criteria regarding the placement of an air sampling probe. The LV-C2, LV-S2, and LV-S3 exhaust stacks were tested together as a group (Test Group 1-2A). This report only covers the results of LV-S2 and LV-S3; LV-C2 will be reported on separately. Federal regulations1 require that a sampling probe be located in the exhaust stack according to the criteria established by the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. 2 These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream.
Energy Technology Data Exchange (ETDEWEB)
Viggiano Guerra, J.C.; Sandoval Medina, F.; Flores Armenta, M.C. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: fernando.sandoval@cfe.gob.mx, E-mail: magaly.flores@cfe.gob.mx; Perez, R.J. [Universidad de Calgary (Canada); Gonzalez Partida, E. [Universidad Nacional Autonoma de Mexico, Centro de Geociencias, Mexico, D.F. (Mexico)
2009-01-15
SPCALC is an excellent software application providing chemical and multi-phase speciation for geothermal fluids. Recently it was acquired by the Comision Federal de Electricidad (CFE) through a contract with the National Autonomous University of Mexico (UNAM) and the University of Calgary, Canada. Software methodology consists of calculating thermodynamic variables, such as activity (a) and fugacity (f) of chemical species, as well as the saturation indices (log Q/K) of mineral phases of the reservoir. In other words, it models the thermodynamic conditions of the reservoir (pH among other) and simulates the fluid-corrosion rate. This allows the software to foresee scaling and corrosion. In this paper, pervasive fluids in Cretaceous granitic rocks penetrated by wells LV-4A, LV-11 and LV-13 in Las Tres Virgenes geothermal field, BCS, are modeled, starting with chemical analyses. The more important ratios among activities [those which influence the fluid-rock interaction (i.e. {sup a}K{sup +}/{sup a}H{sup +}, {sup a}Ca{sup ++}/{sup a}H{sup +}, {sup a}Na{sup +}/{sup a}H{sup +}, {sup a}Mg{sup ++}/{sup a}H{sup +}) and whose results are the minerals visible under a microscope] are graphed in balance diagrams compatible with the pressure (P) and temperature (T) conditions in the reservoir. Epidote (zoisite) is the mineral found in congruent equilibrium with the system. The main mineral association at those conditions (200-250 degrees Celsius and {approx}18 bar), as observed in the well cuttings, is calcite+illite-quartz{+-}epidote, which is explained by the hydrolithic reactions that form replacement calcite in the presence of CO{sub 2}, thus restricting the formation of epidote and eventually eliminating it. The process enhances the CO{sub 2} molarity in the residual fluid, even up to {sup m}CO{sub 2} 1, which means the CO{sub 2} can be diluted back into fluid and intervene again in the process of calcite formation (2HCO{sub 3}{sup -} + Ca{sup ++} = calcite + H{sub 2}O
Studies on the synthesis of isotopes of superheavy element Lv (Z = 116)
Energy Technology Data Exchange (ETDEWEB)
Santhosh, K.P.; Safoora, V. [Kannur University, School of Pure and Applied Physics, Payyanur (India)
2017-11-15
The probable projectile-target combinations for the synthesis of superheavy nucleus {sup 296}Lv found in the cold valley of {sup 296}Lv have been identified by studying the interaction barrier of the colliding nuclei, probability of compound nucleus formation, P{sub CN}, and survival probability W{sub sur}. At energies near and above the Coulomb barrier, the capture, fusion and evaporation residue (ER) cross sections for the probable combinations for the hot and cold fusion reactions are systematically investigated. By considering intensities of the projectile beams, availabilities of the targets and half lives of the colliding nuclei, the combination {sup 48}Ca + {sup 248}Cm is found to be the most probable projectile-target pair for the synthesis of {sup 296}Lv. The calculated maximum value of 2n, 3n, 4n and 5n channel cross section for the reaction {sup 48}Ca + {sup 248}Cm are 0.599 pb, 5.957 pb, 4.805 pb, and 0.065 pb, respectively. Moreover, the production cross sections for the synthesis of isotopes {sup 291-295,298}Lv using {sup 48}Ca projectile on {sup 243-247,250}Cm targets are calculated. Among these reactions, the reactions {sup 48}Ca + {sup 247}Cm → {sup 295}Lv and {sup 48}Ca + {sup 250}Cm → {sup 298}Lv have maximum production cross section in 3n (10.697 pb) and 4n (12.006 pb) channel, respectively. Our studies on the SHE Lv using the combinations {sup 48}Ca + {sup 245}Cm → {sup 293}Lv and {sup 48}Ca + {sup 248}Cm → {sup 296}Lv are compared with available experimental data and with other theoretical studies. Our studies are in agreement with experimental data and we hope that these studies will be a guide for the future experiments to synthesize the isotopes of Lv. (orig.)
Biodegradation of di-n-butyl phthalate by bacterial consortium LV-1 enriched from river sludge.
Directory of Open Access Journals (Sweden)
Yangyang Wang
Full Text Available A stable bacterial consortium (LV-1 capable of degrading di-n-butyl phthalate (DBP was enriched from river sludge. Community analysis revealed that the main families of LV-1 are Brucellaceae (62.78% and Sinobacteraceae (14.83%, and the main genera of LV-1 are Brucella spp. (62.78% and Sinobacter spp. (14.83%. The optimal pH and temperature for LV-1 to degrade DBP were pH 6.0 and 30°C, respectively. Inoculum size influenced the degradation ratio when the incubation time was < 24 h. The initial concentration of DBP also influenced the degradation rates of DBP by LV-1, and the degradation rates ranged from 69.0-775.0 mg/l/d in the first 24 h. Degradation of DBP was best fitted by first-order kinetics when the initial concentration was < 300 mg/l. In addition, Cd2+, Cr6+, and Zn2+ inhibited DBP degradation by LV-1 at all considered concentrations, but low concentrations of Pb2+, Cu2+, and Mn2+ enhanced DBP degradation. The main intermediates (mono-ethyl phthalate [MEP], mono-butyl phthalate [MBP], and phthalic acid [PA] were identified in the DBP degradation process, thus a new biochemical pathway of DBP degradation is proposed. Furthermore, LV-1 also degraded other phthalates with shorter ester chains (DMP, DEP, and PA.
Removal of the liquid waste storage tank LV-2 in JRTF. Part 2. Removal works
International Nuclear Information System (INIS)
Kanayama, Fumihiko; Hagiya, Kazuaki; Sunaoshi, Mizuho; Muraguchi, Yoshinori; Satomi, Shinichi; Nemoto, Kouichi; Terunuma, Akihiro; Shiraishi, Kunio; Ito, Shinichi
2011-06-01
Dismantling activities of components in JAERI's Reprocessing Test Facility (JRTF) started from 1996 as a part of decommissioning of this facility. Removing out of a large liquid waste storage tank LV-2 as a whole tank from the annex building B without cutting in pieces to confirm safety and efficiency of this method started from 2006. After preparatory works, ceiling of LV-2 room was opened, and LV-2 was transferred. Useful data such as manpower, radiation control and waste amount through these works were collected, and work efficiency was analyzed by using of these data. (author)
La piattaforma POS/LV di Applanix nelle applicazioni di laser scanner cinematico
Domenico Santarsiero
2008-01-01
The Applanix POS/LV platform in cinematic laser scanner applicationsOn the 11th of march the GEOmedia editorial unit had the pleasure of hosting a technical meeting dedicated to the Applanix LANDMark new Position and Orientation System for Land Vehicles (POS/LV)field test. The meeting, which is part of an italian tour organized by Louis Nastro (Applanix Director of Land Products) and Terenzio Mariani (Sales manager for Italy), helped to test the functionalities of a complete POS/LV system equ...
Impact Study of Electric Vehicle (EV) Integration on Low Voltage (LV) Grids
DEFF Research Database (Denmark)
Wu, Qiuwei; Cha, Seung-Tae; Nielsen, Arne Hejde
2012-01-01
the single line diagram (SLD) of the LV grid. The demand profiles of end-users are determined by the end-user yearly consumption and avreaged demand profiles of different customer types in Denmark. Five charging scenarios have been tested using the developed LV grid. The first two charging scenarios are dumb....... The two charging power levels are 1 phase 16 A and 3 phase 16 A. The loading of the power components and voltage profile are analyzed to quantify the impact of the charging scenarios and charging power levels on LV grids....
Gullian, Mariel; Rodríguez, Jenny
2002-01-01
Estudio de las cualidades inmunoestimulantes de nuevas bacterias probióticas asociadas al cultivo de LV Estudio de las cualidades inmunoestimulantes de nuevas bacterias probióticas asociadas al cultivo de LV
Electromagnetic cloaking in higher order spherical cloaks
Sidhwa, H. H.; Aiyar, R. P. R. C.; Kulkarni, S. V.
2017-06-01
The inception of transformation optics has led to the realisation of the invisibility devices for various applications, one of which is spherical cloaking. In this paper, a formulation for a higher-order spherical cloak has been proposed to reduce its physical thickness significantly by introducing a nonlinear relation between the original and transformed coordinate systems and it has been verified using the ray tracing approach. Analysis has been carried out to observe the anomalies in the variation of refractive index for higher order cloaks indicating the presence of poles in the relevant equations. Furthermore, a higher-order spherical cloak with predefined values of the material characteristics on its inner and outer surfaces has been designed for practical application.
International Nuclear Information System (INIS)
Flotats, A.; Camacho, V.; Mena, E.; Tembl, A.; Estorch, M.; Carrio, I.; Serra-Grima, R.; Borras, X.; Cinca, J.
2002-01-01
Aim: Marked ventricular re-polarization abnormalities (MRA) in athletes may suggest the presence of associated heart disease. Assessment of LV function during exercise may contribute to rule out heart disease and help to decide continuation of physical training. The aim of the study was to assess whether athletes with MRA show a particular response of LV function to exhausting exercise. Material and Methods: Thirty-nine male athletes underwent monitoring of LV function with a miniaturised radionuclide detector (VEST, Capintec, Inc.) during bicycle exhausting exercise. There were 22 athletes with MRA in the ECG at rest (negative T waves equal or more than 2mm in up to 3 ECG leads) and 17 with normal ECG. All were symptom free. Age and physical fitness were comparable in both groups. Clinical examination, ECG, exercise test and echocardiography were performed in all athletes. Results: In all cases LV wall thickness was that expected for highly conditioned sportsmen. Both groups of athletes attained a similar energy expenditure. During exercise, athletes with MRA showed a tendency to normalise re-polarization. There were no differences in heart rate, LV end-systolic volume, LVEF, cardiac output , and peak ejection and filling rates at rest, 50%, 75%, 85% and 100% of peak HR, nor at 2, 5 and 10 min of recovery between both groups of athletes. At rest stroke volume was lower in athletes with MRA (60% vs. 64%, p=0.044). There were also no differences in LV end-diastolic volume (EDV), except at peak HR, when EDV increased in athletes with normal ECG while it decreased in athletes with MRA (p=0.047). Conclusions: The presence of marked ventricular re-polarization abnormalities in athletes does not substantially affect exercise performance nor LV function and should not preclude physical training. The VEST is a useful means to assess LV function during exhausting upright bicycle exercise
The Spherical Deformation Model
DEFF Research Database (Denmark)
Hobolth, Asgar
2003-01-01
Miller et al. (1994) describe a model for representing spatial objects with no obvious landmarks. Each object is represented by a global translation and a normal deformation of a sphere. The normal deformation is defined via the orthonormal spherical-harmonic basis. In this paper we analyse the s...
Spherical rhenium metal powder
International Nuclear Information System (INIS)
Leonhardt, T.; Moore, N.; Hamister, M.
2001-01-01
The development of a high-density, spherical rhenium powder (SReP) possessing excellent flow characteristics has enabled the use of advanced processing techniques for the manufacture of rhenium components. The techniques that were investigated were vacuum plasma spraying (VPS), direct-hot isostatic pressing (D-HIP), and various other traditional powder metallurgy processing methods of forming rhenium powder into near-net shaped components. The principal disadvantages of standard rhenium metal powder (RMP) for advanced consolidation applications include: poor flow characteristics; high oxygen content; and low and varying packing densities. SReP will lower costs, reduce processing times, and improve yields when manufacturing powder metallurgy rhenium components. The results of the powder characterization of spherical rhenium powder and the consolidation of the SReP are further discussed. (author)
International Nuclear Information System (INIS)
Berg, S.; Semmes, P.B.; Nazarewicz, W.
1997-01-01
Various theoretical approaches to proton emission from spherical nuclei are investigated, and it is found that all the methods employed give very similar results. The calculated decay widths are found to be qualitatively insensitive to the parameters of the proton-nucleus potential, i.e., changing the potential parameters over a fairly large range typically changes the decay width by no more than a factor of ∼3. Proton half-lives of observed heavy proton emitters are, in general, well reproduced by spherical calculations with the spectroscopic factors calculated in the independent quasiparticle approximation. The quantitative agreement with experimental data obtained in our study requires that the parameters of the proton-nucleus potential be chosen carefully. It also suggests that deformed proton emitters will provide invaluable spectroscopic information on the angular momentum decomposition of single-proton orbitals in deformed nuclei. copyright 1997 The American Physical Society
The Spherical Deformation Model
DEFF Research Database (Denmark)
Hobolth, Asgar
2003-01-01
Miller et al. (1994) describe a model for representing spatial objects with no obvious landmarks. Each object is represented by a global translation and a normal deformation of a sphere. The normal deformation is defined via the orthonormal spherical-harmonic basis. In this paper we analyse the s...... a single central section of the object. We use maximum-likelihood-based inference for this purpose and demonstrate the suggested methods on real data....
Inferring microbial interaction networks from metagenomic data using SgLV-EKF algorithm.
Alshawaqfeh, Mustafa; Serpedin, Erchin; Younes, Ahmad Bani
2017-03-27
Inferring the microbial interaction networks (MINs) and modeling their dynamics are critical in understanding the mechanisms of the bacterial ecosystem and designing antibiotic and/or probiotic therapies. Recently, several approaches were proposed to infer MINs using the generalized Lotka-Volterra (gLV) model. Main drawbacks of these models include the fact that these models only consider the measurement noise without taking into consideration the uncertainties in the underlying dynamics. Furthermore, inferring the MIN is characterized by the limited number of observations and nonlinearity in the regulatory mechanisms. Therefore, novel estimation techniques are needed to address these challenges. This work proposes SgLV-EKF: a stochastic gLV model that adopts the extended Kalman filter (EKF) algorithm to model the MIN dynamics. In particular, SgLV-EKF employs a stochastic modeling of the MIN by adding a noise term to the dynamical model to compensate for modeling uncertainties. This stochastic modeling is more realistic than the conventional gLV model which assumes that the MIN dynamics are perfectly governed by the gLV equations. After specifying the stochastic model structure, we propose the EKF to estimate the MIN. SgLV-EKF was compared with two similarity-based algorithms, one algorithm from the integral-based family and two regression-based algorithms, in terms of the achieved performance on two synthetic data-sets and two real data-sets. The first data-set models the randomness in measurement data, whereas, the second data-set incorporates uncertainties in the underlying dynamics. The real data-sets are provided by a recent study pertaining to an antibiotic-mediated Clostridium difficile infection. The experimental results demonstrate that SgLV-EKF outperforms the alternative methods in terms of robustness to measurement noise, modeling errors, and tracking the dynamics of the MIN. Performance analysis demonstrates that the proposed SgLV-EKF algorithm
A Simple Generator of Forward Scattering Functions on Spherical Dielectrics
Directory of Open Access Journals (Sweden)
O. Fiser
1993-04-01
Full Text Available The described program generates the forward scattering functions of dielectrics of spherical shape, while the input parameters are: frequency, radius of the sphere and complex refractive index. The part enabling to evaluate the complex refractive index of water in the dependence on frequency and temperature is added.
Efficient Control of Energy Storage for Increasing the PV Hosting Capacity of LV Grids
DEFF Research Database (Denmark)
Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob
2016-01-01
grid is usually limited by overvoltage, and the efficient control of distributed electrical energy storage systems (EESSs) can considerably increase this capacity. In this paper, a new control approach based on the voltage sensitivity analysis is proposed to prevent overvoltage and increase the PV......Photovoltaic (PV) systems are among the renewable sources that electrical energy systems are adopting with increasing frequency. The majority of already-installed PV systems are decentralized units that are usually connected to lowvoltage (LV) distribution grids. The PV hosting capacity of an LV...... hosting capacity of LV grids by determining dynamic set points for EESS management. The method has the effectiveness of central control methods and can effectively decrease the energy storage required for overvoltage prevention, yet it eliminates the need for a broadband and fast communication. The net...
EV Charging Facilities and Their Application in LV Feeders with Photovoltaics
DEFF Research Database (Denmark)
Marra, Francesco; Yang, Guangya; Træholt, Chresten
2013-01-01
Low-voltage (LV) grid feeders with high penetration of photovoltaics (PVs) are often affected by voltage magnitude problems. To solve such issues, previous research has shown that reactive power methods, active power curtailment and grid reinforcement can be used for voltage support, yet showing...... several limits. We introduce the use of electric vehicle (EV) public charging stations with energy storage system (ESS) as a solution for voltage regulation in LV feeders with PV. A novel method is proposed to determine the ESS charging load required for voltage regulation and compare the results...... for the different locations in the feeder. With time-series simulations, we quantify the energy size required for a station ESS. A Belgian LV residential grid, modeled using real PV generation and load profiles, is used as case study. The method and simulation results show the effectiveness of using public EV...
La piattaforma POS/LV di Applanix nelle applicazioni di laser scanner cinematico
Directory of Open Access Journals (Sweden)
Domenico Santarsiero
2008-03-01
Full Text Available The Applanix POS/LV platform in cinematic laser scanner applicationsOn the 11th of march the GEOmedia editorial unit had the pleasure of hosting a technical meeting dedicated to the Applanix LANDMark new Position and Orientation System for Land Vehicles (POS/LVfield test. The meeting, which is part of an italian tour organized by Louis Nastro (Applanix Director of Land Products and Terenzio Mariani (Sales manager for Italy, helped to test the functionalities of a complete POS/LV system equipped with a laser and an imaging acquisition software installed on board of a SUV.
Holographic Spherically Symmetric Metrics
Petri, Michael
The holographic principle (HP) conjectures, that the maximum number of degrees of freedom of any realistic physical system is proportional to the system's boundary area. The HP has its roots in the study of black holes. It has recently been applied to cosmological solutions. In this article we apply the HP to spherically symmetric static space-times. We find that any regular spherically symmetric object saturating the HP is subject to tight constraints on the (interior) metric, energy-density, temperature and entropy-density. Whenever gravity can be described by a metric theory, gravity is macroscopically scale invariant and the laws of thermodynamics hold locally and globally, the (interior) metric of a regular holographic object is uniquely determined up to a constant factor and the interior matter-state must follow well defined scaling relations. When the metric theory of gravity is general relativity, the interior matter has an overall string equation of state (EOS) and a unique total energy-density. Thus the holographic metric derived in this article can serve as simple interior 4D realization of Mathur's string fuzzball proposal. Some properties of the holographic metric and its possible experimental verification are discussed. The geodesics of the holographic metric describe an isotropically expanding (or contracting) universe with a nearly homogeneous matter-distribution within the local Hubble volume. Due to the overall string EOS the active gravitational mass-density is zero, resulting in a coasting expansion with Ht = 1, which is compatible with the recent GRB-data.
Integration of SPICE with TEK LV500 ASIC Design Verification System
Directory of Open Access Journals (Sweden)
A. Srivastava
1996-01-01
Full Text Available The present work involves integration of the simulation stage of design of a VLSI circuit and its testing stage. The SPICE simulator, TEK LV500 ASIC Design Verification System, and TekWaves, a test program generator for LV500, were integrated. A software interface in ‘C’ language in UNIX ‘solaris 1.x’ environment has been developed between SPICE and the testing tools (TekWAVES and LV500. The function of the software interface developed is multifold. It takes input from either SPICE2G.6 or SPICE 3e.1. The output generated by the interface software can be given as an input to either TekWAVES or LV500. A graphical user interface has also been developed with OPENWlNDOWS using Xview tool kit on SUN workstation. As an example, a two phase clock generator circuit has been considered and usefulness of the software demonstrated. The interface software could be easily linked with VLSI design such as MAGIC layout editor.
77 FR 21620 - Notice of the Buy America Waiver Request for Vossloh 101-LV Concrete Ties
2012-04-10
... the Buy America Waiver Request for Vossloh 101-LV Concrete Ties AGENCY: Federal Railroad... concrete ties, which contain certain components not manufactured in the United States. In furtherance of... concrete ties. FRA has received this request from the four States for the following projects: (a) The...
Choloniewski, J.; Valentijn, E. A.
A new method for the determination of the extinction in the Galaxy is proposed. The method uses surface brightnesses of external galaxies in the B and R-bands. The observational data have been taken from the ESO-LV galaxy catalog. As a first application of our model we derive the ratio of R-band to
Current distribution in LV networks during 1-phase MV short-circuit
Waes, van J.B.M.; Provoost, F.; Merwe, van der J.; Cobben, J.F.G.; Deursen, van A.P.J.; van Riet, M.J.M.; Laan, van der P.C.T.
2000-01-01
This paper describes the consequences of a fault in a medium voltage network on the grounding systems at the LV-side. To study the current distribution and to verify the models, we deliberately introduced one phase to ground faults in the 10 kV floating MV network. The selected site was the end of a
La piattaforma POS/LV di Applanix nelle applicazioni di laser scanner cinematico
Directory of Open Access Journals (Sweden)
Domenico Santarsiero
2008-03-01
field test. The meeting, which is part of an italian tour organized by Louis Nastro (Applanix Director of Land Products and Terenzio Mariani (Sales manager for Italy, helped to test the functionalities of a complete POS/LV system equipped with a laser and an imaging acquisition software installed on board of a SUV.
Distributed generation in the Dutch LV network - self-supporting residential area
Mes, M.; Vanalme, G.M.A.; Myrzik, J.M.A.; Bongaerts, M.; Verbong, G.P.J.; Kling, W.L.
2008-01-01
A self-supporting residential area is seen as an alternative operational approach of power supply in low voltage (LV) networks. The intention of the new approach is to exploit the advantages of distributed generation (DG) and avoid the difficulties, that come with DG when implemented in the
Haque, A.N.M.M.; Nguyen, H.P.; Vo, T.; Bliek, F.W.
2016-01-01
Rapid proliferation of the distributed energy resources (DERs) poses operational challenges for the low-voltage (LV) distribution networks in terms of thermal overloading of the network assets along with voltage limit violations at the connection points. A number of market-based and direct control
Coordinated control to mitigate over voltage and under voltage in LV networks
Viyathukattuva Mohamed Ali, M.M.; Nguyen, H.P.; Cobben, J.F.G.
2016-01-01
Increasing penetration of distributed renewable energy resources (DRES) and smart loads into the LV network lead to new power quality challenges. Important power quality challenges are overvoltage and undervoltage. A number of solutions are already developed to mitigate these voltage variations. In
Effect of spherical aberration on scintillations of Gaussian beams in atmospheric turbulence
International Nuclear Information System (INIS)
Ji, Xiaoling; Deng, Jinping
2014-01-01
The effect of spherical aberration on scintillations of Gaussian beams in weak, moderate and strong turbulence is studied using numerical simulation method. It is found that the effect of the negative spherical aberration on the on-axis scintillation index is quite different from that of the positive spherical aberration. In weak turbulence, the positive spherical aberration results in a decrease of the on-axis scintillation index on propagation, but the negative spherical aberration results in an increase of the on-axis scintillation index when the propagation distance is not large. In particular, in weak turbulence the negative spherical aberration may cause peaks of the on-axis scintillation index, and the peaks disappear in moderate and strong turbulence, which is explained in physics. The strong turbulence leads to less discrepancy among scintillations of Gaussian beams with and without spherical aberration. - Highlights: • In weak turbulence scintillations can be suppressed using positive spherical aberration. • In weak turbulence scintillations may be very large due to negative spherical aberration. • The effect of spherical aberration on scintillations is less with increasing of turbulence
Effect of spherical aberration on scintillations of Gaussian beams in atmospheric turbulence
Energy Technology Data Exchange (ETDEWEB)
Ji, Xiaoling, E-mail: jiXL100@163.com; Deng, Jinping
2014-07-18
The effect of spherical aberration on scintillations of Gaussian beams in weak, moderate and strong turbulence is studied using numerical simulation method. It is found that the effect of the negative spherical aberration on the on-axis scintillation index is quite different from that of the positive spherical aberration. In weak turbulence, the positive spherical aberration results in a decrease of the on-axis scintillation index on propagation, but the negative spherical aberration results in an increase of the on-axis scintillation index when the propagation distance is not large. In particular, in weak turbulence the negative spherical aberration may cause peaks of the on-axis scintillation index, and the peaks disappear in moderate and strong turbulence, which is explained in physics. The strong turbulence leads to less discrepancy among scintillations of Gaussian beams with and without spherical aberration. - Highlights: • In weak turbulence scintillations can be suppressed using positive spherical aberration. • In weak turbulence scintillations may be very large due to negative spherical aberration. • The effect of spherical aberration on scintillations is less with increasing of turbulence.
Evolution of the spherical clusters
International Nuclear Information System (INIS)
Surdin, V.G.
1978-01-01
The possible processes of the Galaxy spherical clusters formation and evolution are described on a popular level. The orbits of spherical cluster motion and their spatial velocities are determined. Given are the distrbutions of spherical cluster stars according to their velocities and the observed distribution of spherical clusters in the area of the Galaxy slow evolution. The dissipation and dynamic friction processes destructing clusters with the mass less than 10 4 of solar mass and bringing about the reduction of clusters in the Galaxy are considered. The paradox of forming mainly X-ray sources in spherical clusters is explained. The schematic image of possible ways of forming X-ray sources in spherical clusters is given
Spherical tokamak development in Brazil
Energy Technology Data Exchange (ETDEWEB)
Ludwig, Gerson Otto; Bosco, Edson Del; Ferreira, Julio Guimaraes [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma] (and others)
2003-07-01
The general characteristics of spherical tokamaks, or spherical tori, with a brief view of work in this area already performed or in progress at several institutions worldwide are described. The paper presents also the steps in the development of the ETE (Experiment Tokamak spheric) project, its research program, technical characteristics and operating conditions as of December, 2002 a the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)
Spherical tokamak development in Brazil
International Nuclear Information System (INIS)
Ludwig, Gerson Otto; Bosco, Edson Del; Ferreira, Julio Guimaraes
2003-01-01
The general characteristics of spherical tokamaks, or spherical tori, with a brief view of work in this area already performed or in progress at several institutions worldwide are described. The paper presents also the steps in the development of the ETE (Experiment Tokamak spheric) project, its research program, technical characteristics and operating conditions as of December, 2002 a the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)
Spherical grating spectrometers
O'Donoghue, Darragh; Clemens, J. Christopher
2014-07-01
We describe designs for spectrometers employing convex dispersers. The Offner spectrometer was the first such instrument; it has almost exclusively been employed on satellite platforms, and has had little impact on ground-based instruments. We have learned how to fabricate curved Volume Phase Holographic (VPH) gratings and, in contrast to the planar gratings of traditional spectrometers, describe how such devices can be used in optical/infrared spectrometers designed specifically for curved diffraction gratings. Volume Phase Holographic gratings are highly efficient compared to conventional surface relief gratings; they have become the disperser of choice in optical / NIR spectrometers. The advantage of spectrometers with curved VPH dispersers is the very small number of optical elements used (the simplest comprising a grating and a spherical mirror), as well as illumination of mirrors off axis, resulting in greater efficiency and reduction in size. We describe a "Half Offner" spectrometer, an even simpler version of the Offner spectrometer. We present an entirely novel design, the Spherical Transmission Grating Spectrometer (STGS), and discuss exemplary applications, including a design for a double-beam spectrometer without any requirement for a dichroic. This paradigm change in spectrometer design offers an alternative to all-refractive astronomical spectrometer designs, using expensive, fragile lens elements fabricated from CaF2 or even more exotic materials. The unobscured mirror layout avoids a major drawback of the previous generation of catadioptric spectrometer designs. We describe laboratory measurements of the efficiency and image quality of a curved VPH grating in a STGS design, demonstrating, simultaneously, efficiency comparable to planar VPH gratings along with good image quality. The stage is now set for construction of a prototype instrument with impressive performance.
First results of spherical GEMs
Pinto, Serge Duarte; Brock, Ian; Croci, Gabriele; David, Eric; de Oliveira, Rui; Ropelewski, Leszek; van Stenis, Miranda; Taureg, Hans; Villa, Marco
2010-01-01
We developed a method to make GEM foils with a spherical geometry. Tests of this procedure and with the resulting spherical GEMs are presented. Together with a spherical drift electrode, a spherical conversion gap can be formed. This eliminates the parallax error for detection of x-rays, neutrons or UV photons when a gaseous converter is used. This parallax error limits the spatial resolution at wide scattering angles. Besides spherical GEMs, we have developed curved spacers to maintain accurate spacing, and a conical field cage to prevent edge distortion of the radial drift field up to the limit of the angular acceptance of the detector. With these components first tests are done in a setup with a spherical entrance window but a planar readout structure; results will be presented and discussed. A flat readout structure poses difficulties, however. Therefore we will show advanced plans to make a prototype of an entirely spherical double-GEM detector, including a spherical 2D readout structure. This detector w...
Spherical Torus Center Stack Design
International Nuclear Information System (INIS)
C. Neumeyer; P. Heitzenroeder; C. Kessel; M. Ono; M. Peng; J. Schmidt; R. Woolley; I. Zatz
2002-01-01
The low aspect ratio spherical torus (ST) configuration requires that the center stack design be optimized within a limited available space, using materials within their established allowables. This paper presents center stack design methods developed by the National Spherical Torus Experiment (NSTX) Project Team during the initial design of NSTX, and more recently for studies of a possible next-step ST (NSST) device
Energy Technology Data Exchange (ETDEWEB)
Dowker, J S, E-mail: dowker@man.ac.uk [Theory Group, School of Physics and Astronomy, University of Manchester, Manchester (United Kingdom)
2011-08-07
A piston is introduced into a spherical lune Casimir cavity turning it into two adjacent lunes separated by the (hemispherical) piston. On the basis of zeta-function regularization, the vacuum energy of the arrangement is finite for conformal propagation in spacetime. For even spheres this energy is independent of the angle of the lune. For odd dimensions it is shown that for all Neumann, or all Dirichlet, boundary conditions the piston is repelled or attracted by the nearest wall if d = 3, 7, ... or if d = 1, 5, ... , respectively. For hybrid N-D conditions these requirements are switched. If a mass is added, divergences arise which render the model suspect. The analysis, however, is relatively straightforward and involves the Barnes zeta function. The extension to finite temperatures is made and it is shown that for the 3, 7, ... series of odd spheres, the repulsion by the walls continues but that, above a certain temperature, the free energy acquires two minima symmetrically placed about the midpoint.
International Nuclear Information System (INIS)
Dowker, J S
2011-01-01
A piston is introduced into a spherical lune Casimir cavity turning it into two adjacent lunes separated by the (hemispherical) piston. On the basis of zeta-function regularization, the vacuum energy of the arrangement is finite for conformal propagation in spacetime. For even spheres this energy is independent of the angle of the lune. For odd dimensions it is shown that for all Neumann, or all Dirichlet, boundary conditions the piston is repelled or attracted by the nearest wall if d = 3, 7, ... or if d = 1, 5, ... , respectively. For hybrid N-D conditions these requirements are switched. If a mass is added, divergences arise which render the model suspect. The analysis, however, is relatively straightforward and involves the Barnes zeta function. The extension to finite temperatures is made and it is shown that for the 3, 7, ... series of odd spheres, the repulsion by the walls continues but that, above a certain temperature, the free energy acquires two minima symmetrically placed about the midpoint.
Resistance to RadLV-induced leukemia: non-participation of splenic natural killer cells
International Nuclear Information System (INIS)
St-Pierre, Y.; Hugo, P.; Lemieux, S.; Lussier, G.; Potworowski, E.F.
1988-01-01
The phenotypic expression of genetically determined resistance to radiation leukemia virus (RadLV)-induced leukemia in mice has been shown to reside in the bone marrow. Because the bone marrow contains precursors of natural killer (NK) cells, known to play a role in retrovirally induced infections, and because these cells have been suggested as participating in resistance to radiation-induced leukemia, it was pertinent to establish whether their levels differed in strains of mice susceptible and resistant to leukemia. We therefore tested splenic NK cell levels in C57BL/Ka (susceptible) and B10.A(5R) (resistant) mice before viral inoculation, immediately after viral inoculation, and throughout the preleukemic period and showed that they were not different. This indicates that splenic NK cell levels have no bearing on the resistance to RadLV-induced leukemia and that other immune or non-immune mechanisms must be sought
Energy Technology Data Exchange (ETDEWEB)
Venegas Salgado, Saul; Arredondo Fragoso, Jesus; Ramirez Silva, German; Flores Armenta, Magaly; Ramirez Montes, Miguel [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: magaly.flores@cfe.gob.mx
2006-07-15
From September through December 2004 a seismic monitoring in the Las Tres Virgenes, BCS, geothermal field was carried out simultaneously with the acid stimulation of wells LV-4 and LV-13. The seismic network had four digital seismographs and recorded 174 local seismic events, 131 regional ones and many more volcanic signals at seismic station TV20 during the acid stimulation. Additionally, 37 seismic events were located, 22 of them inside the most important geothermal zone at depths between 0.4 and 4 km with typically low magnitudes (0.7 to 2.2 Md). Two relevant zones were determined: Zone A related to the El Volcan fault system and Zone B related to injection well LV-8. In Zone A the well-induction stage and the operation start of the wells LV-4 and LV-13 after acidification on October 30 and November 17, 2004, increased seismic activity to a maximum of 12 daily events in early December. When the two wells in Zone B were cooled before the acidification, the seismic events recorded there increased to a maximum of 6 daily events on October 2, and then decreased. Also in Zone B the seismic activity increased after well-induction and the start of well production once they were acidified, recording up to 11 daily events in late November. According to the seismic distribution, we may conclude that the most active fault systems are El Volcan and El Viejo. New proposals for well locations in the field are supported by these results. [Spanish] De septiembre a diciembre de 2004 se realizo un estudio de monitoreo sismico en el campo geotermico de Las Tres Virgenes, BCS, simultaneamente con las estimulaciones acidas de los pozos LV-4 y LV-13. Se utilizo una red sismica conformada por cuatro sismografos digitales, logrando registrar en la estacion sismica TV20 un total de 174 sismos locales, 131 sismos regionales y muchas mas senales de tipo volcanico, durante el periodo del monitoreo de la estimulacion acida. Ademas, se localizaron un total de 37 sismos, de los cuales 22 se
Energy Technology Data Exchange (ETDEWEB)
Song, J.; Shi, Z.; Yang, Y.; Shi, W.; Wei, H.; Zhai, S.; Xie, H. [Taiyuan University of Technology, Taiyuan (China)
2001-02-01
The overcurrent fault characteristics in underground LV cable distribution networks is analysed and the fundamental principle of overcurrent protective system is described in this paper. The emphasis is paid to the determination of the characteristic curves of phase-sensitive symmetrical short-circuit protection, the design of negative-sequence current filter and the definition of the mathematical model of overload. Besides, the hardware block diagram and the software flowchart of the protective system, which is controlled by a single chip microcomputer, is also introduced in the paper. The protective system was tested before being applied to the underground LV distribution networks. The results obtained are in conformity with the design specification. It has been verified that the protective distance is extended and the protective sensitivity is improved with the protective system. The field experience has shown that the protective system is stable and reliable, and will be of great application value in the mining industry. 7 refs., 5 figs., 2 tabs.
Drift of IBL LV current and its consequence in IBL distortion
The ATLAS collaboration
2015-01-01
The low voltage (LV) current of the IBL modules had been stable since the beginning of the Run2 until the middle of September 2015, but it has been unstable since then (Figure 1). A clear relation is observed between the current rise-up and the total radiation doze (TID) increase, which is considered to be the TID effect reported in . A shutdown of more than 29 hour on October 6 recovered the current largely (Figure 2). With the change of the LV current, the temperature of IBL modules also changes (Figure 3). The change of the thermo-mechanical condition of the IBL resulted in the change of the IBL distortion magnitude, and a clear relation between the module temperature and the distortion magnitude is observed (Figure 4). Through the duration presented in this series of plots, the cooling set temperature of the IBL was kept at -10℃.
International Nuclear Information System (INIS)
Luo Zhiyuan; Wang Guangjin; Zhou Bin
2007-01-01
A LV electrical penetration assembly with perfusion sealing conductor feedthrough module was developed, which can be used for the connection of internal and external cables through the wall of the research reactor workshop. The LV electrical penetration assembly was combined with several independent modules. The maintenance and replacement of the assembly can be easily done in service. The sealing of conductor feedthrough module was achieved with the perfusion of self-extinguishing epoxy. The leakage between the conductor feedthrough module and the end plate module was blocked with rubber rings. The result of the leakage test and the electrical performance test for the samples of conductor feedthrough module satisfied the requirement of research reactor. The structure of the new electrical penetration assembly is simple and compact. It can be manufactured with mature technology and cost low price. The performance of the assembly is steady. It can be used widely in research reactors. (authors)
Analysis of critical operating conditions for LV distribution networks with microgrids
Zehir, M. A.; Batman, A.; Sonmez, M. A.; Font, A.; Tsiamitros, D.; Stimoniaris, D.; Kollatou, T.; Bagriyanik, M.; Ozdemir, A.; Dialynas, E.
2016-11-01
Increase in the penetration of Distributed Generation (DG) in distribution networks, raises the risk of voltage limit violations while contributing to line losses. Especially in low voltage (LV) distribution networks (secondary distribution networks), impacts of active power flows on the bus voltages and on the network losses are more dominant. As network operators must meet regulatory limitations, they have to take into account the most critical operating conditions in their systems. In this study, it is aimed to present the impact of the worst operation cases of LV distribution networks comprising microgrids. Simulation studies are performed on a field data-based virtual test-bed. The simulations are repeated for several cases consisting different microgrid points of connection with different network loading and microgrid supply/demand conditions.
‘Lv Peng and his Chinese Art History in Operation, since 1986’
Directory of Open Access Journals (Sweden)
Joshua Gong
2014-06-01
Full Text Available Lv Peng is one of the most influential contemporary Chinese art historians, who began publishing his work in 1986 and introduced various innovative approaches and methods to the field. Even though his work gained momentum in the field, his totalising and continually-revised publication scheme have come under incessant criticism from friends and rivals alike. This article is an attempt at surveying Lv Peng’s oeuvre, while testifying to the value of his art history writings by making his various approaches more legible and systematic. His most popular publications as well as a few projects that are still in progress will be analysed for a more comprehensive understanding of his operational art history.
Voltage unbalance mitigation in LV networks using three-phase PV systems
DEFF Research Database (Denmark)
Garcia Bajo, Cristina; Hashemi Toghroljerdi, Seyedmostafa; Bækhøj Kjær, Søren
2015-01-01
In this paper a new method is proposed to mitigate voltage unbalance caused by single-phase solar inverters in low voltage (LV) networks. The method is based on uneven reactive power absorption and injection by three-phase solar inverters. Independent control of each phase is performed to achieve...... this uneven injection. The average values of phase voltages at the connection points of the photovoltaic (PV) inverters are used as the references for the balancing algorithm. Voltage unbalance mitigation is achieved by use of this method in different scenarios with variable three-phase and single......-phase inverters penetration in a realistic LV grid. In addition, the overvoltage is reduced by using this method....
A New Protection System for Islanding Detection in LV Distribution Systems
Directory of Open Access Journals (Sweden)
Anna Rita Di Fazio
2015-04-01
Full Text Available The growth of penetration of Distributed Generators (DGs is increasing the risk of unwanted islanded operation in Low Voltage (LV distribution systems. In this scenario, the existing anti-islanding protection systems, installed at the DG premises and based on classical voltage and frequency relays, are no longer effective, especially in the cases of islands characterized by a close match between generation and load. In this paper, a new protection system for islanding detection in LV distribution systems is proposed. The classical voltage and frequency relays in the DG interface protections are enriched with an innovative Smart Islanding Detector, which adopts a new passive islanding detection method. The aim is to keep the advantages of the classical relays while overcoming the problem of their limited sensitivity in detecting balanced islands. In the paper, to define the requirements of the anti-islanding protection system, the events causing the islanded operation of the LV distribution systems are firstly identified and classified. Then, referring to proposed protection system, its architecture and operation are described and, eventually, its performance is analyzed and validated by experimental laboratory tests, carried out with a hardware-in-the-loop technique.
Quantifying grain shape with MorpheoLV: A case study using Holocene glacial marine sediments
Charpentier, Isabelle; Staszyc, Alicia B.; Wellner, Julia S.; Alejandro, Vanessa
2017-06-01
As demonstrated in earlier works, quantitative grain shape analysis has revealed to be a strong proxy for determining sediment transport history and depositional environments. MorpheoLV, devoted to the calculation of roughness coefficients from pictures of unique clastic sediment grains using Fourier analysis, drives computations for a collection of samples of grain images. This process may be applied to sedimentary deposits assuming core/interval/image archives for the storage of samples collected along depth. This study uses a 25.8 m jumbo piston core, NBP1203 JPC36, taken from a 100 m thick sedimentary drift deposit from Perseverance Drift on the northern Antarctic Peninsula continental shelf. Changes in ocean and ice conditions throughout the Holocene recorded in this sedimentary archive can be assessed by studying grain shape, grain texture, and other proxies. Ninety six intervals were sampled and a total of 2319 individual particle images were used. Microtextures of individual grains observed by SEM show a very high abundance of authigenically precipitated silica that obscures the original grain shape. Grain roughness, computed along depth with MorpheoLV, only shows small variation confirming the qualitative observation deduced from the SEM. Despite this, trends can be seen confirming the reliability of MorpheoLV as a tool for quantitative grain shape analysis.
Quantifying grain shape with MorpheoLV: A case study using Holocene glacial marine sediments
Directory of Open Access Journals (Sweden)
Charpentier Isabelle
2017-01-01
Full Text Available As demonstrated in earlier works, quantitative grain shape analysis has revealed to be a strong proxy for determining sediment transport history and depositional environments. MorpheoLV, devoted to the calculation of roughness coefficients from pictures of unique clastic sediment grains using Fourier analysis, drives computations for a collection of samples of grain images. This process may be applied to sedimentary deposits assuming core/interval/image archives for the storage of samples collected along depth. This study uses a 25.8 m jumbo piston core, NBP1203 JPC36, taken from a ~100 m thick sedimentary drift deposit from Perseverance Drift on the northern Antarctic Peninsula continental shelf. Changes in ocean and ice conditions throughout the Holocene recorded in this sedimentary archive can be assessed by studying grain shape, grain texture, and other proxies. Ninety six intervals were sampled and a total of 2319 individual particle images were used. Microtextures of individual grains observed by SEM show a very high abundance of authigenically precipitated silica that obscures the original grain shape. Grain roughness, computed along depth with MorpheoLV, only shows small variation confirming the qualitative observation deduced from the SEM. Despite this, trends can be seen confirming the reliability of MorpheoLV as a tool for quantitative grain shape analysis.
Directory of Open Access Journals (Sweden)
Shijun Xie
Full Text Available White spot syndrome virus (WSSV is a major pathogen in shrimp cultures. The interactions between viral proteins and their receptors on the surface of cells in a frontier target tissue are crucial for triggering an infection. In this study, a yeast two-hybrid (Y2H library was constructed using cDNA obtained from the stomach and gut of Litopenaeus vannamei, to ascertain the role of envelope proteins in WSSV infection. For this purpose, VP37 was used as the bait in the Y2H library screening. Forty positive clones were detected after screening. The positive clones were analyzed and discriminated, and two clones belonging to the peritrophin family were subsequently confirmed as genuine positive clones. Sequence analysis revealed that both clones could be considered as the same gene, LV-peritrophin (LvPT. Co-immunoprecipitation confirmed the interaction between LvPT and VP37. Further studies in the Y2H system revealed that LvPT could also interact with other WSSV envelope proteins such as VP32, VP38A, VP39B, and VP41A. The distribution of LvPT in tissues revealed that LvPT was mainly expressed in the stomach than in other tissues. In addition, LvPT was found to be a secretory protein, and its chitin-binding ability was also confirmed.
Spherical transceivers for ultrafast optical wireless communications
Jin, Xian; Hristovski, Blago A.; Collier, Christopher M.; Geoffroy-Gagnon, Simon; Born, Brandon; Holzman, Jonathan F.
2016-02-01
Optical wireless communications (OWC) offers the potential for high-speed and mobile operation in indoor networks. Such OWC systems often employ a fixed transmitter grid and mobile transceivers, with the mobile transceivers carrying out bi-directional communication via active downlinks (ideally with high-speed signal detection) and passive uplinks (ideally with broad angular retroreflection and high-speed modulation). It can be challenging to integrate all of these bidirectional communication capabilities within the mobile transceivers, however, as there is a simultaneous desire for compact packaging. With this in mind, the work presented here introduces a new form of transceiver for bi-directional OWC systems. The transceiver incorporates radial photoconductive switches (for high-speed signal detection) and a spherical retro-modulator (for broad angular retroreflection and high-speed all-optical modulation). All-optical retromodulation are investigated by way of theoretical models and experimental testing, for spherical retro-modulators comprised of three glasses, N-BK7, N-LASF9, and S-LAH79, having differing levels of refraction and nonlinearity. It is found that the spherical retro-modulator comprised of S-LAH79, with a refractive index of n ≍ 2 and a Kerr nonlinear index of n2 ≍ (1.8 ± 0.1) × 10-15 cm2/W, yields both broad angular retroreflection (over a solid angle of 2π steradians) and ultrafast modulation (over a duration of 120 fs). Such transceivers can become important elements for all-optical implementations in future bi-directional OWC systems.
JUST: Joint Upgraded Spherical Tokamak
International Nuclear Information System (INIS)
Azizov, E.A.; Dvorkin, N.Ya.; Filatov, O.G.
1997-01-01
The main goals, ideas and the programme of JUST, spherical tokamak (ST) for the plasma burn investigation, are presented. The place and prospects of JUST in thermonuclear investigations are discussed. (author)
Directory of Open Access Journals (Sweden)
Laura S. Levy
2011-09-01
Full Text Available Detailed analysis has been performed over many years of a geographic and temporal cohort of cats naturally infected with feline leukemia virus (FeLV. Molecular analysis of FeLV present in the diseased tissues and application of those viruses to experimental systems has revealed unique isolates with distinctive disease potential, previously uncharacterized virus-receptor interactions, information about the role of recombinant viruses in disease induction, and novel viral and cellular oncogenes implicated in pathogenesis, among other findings. The studies have contributed to an understanding of the selective forces that lead to predominance of distinctive FeLV isolates and disease outcomes in a natural population.
Spherical tokamak development in Brazil
International Nuclear Information System (INIS)
Ludwig, G.O.; Del Bosco, E.; Ferreira, J.G.; Berni, L.A.; Oliveira, R.M.; Andrade, M.C.R.; Shibata, C.S.; Ueda, M.; Barroso, J.J.; Castro, P.J.; Barbosa, L.F.W.; Patire Junior, H.; The high-power microwave sources group
2003-01-01
This paper describes the general characteristics of spherical tokamaks, or spherical tori, with a brief overview of work in this area already performed or in progress at several institutions worldwide. The paper presents also the steps in the development of the ETE (Experimento Tokamak Esferico) project, its research program, technical characteristics and operating conditions as of December, 2002 at the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)
Miniaturization of Spherical Magnetodielectric Antennas
DEFF Research Database (Denmark)
Hansen, Troels Vejle
; Arbitrary order of the spherical wave, arbitrary radius of the spherical antenna, as well as arbitrarily large core permeability and/or permittivity, given an inversely proportional frequency variation of the imaginary part(s) and an arbitrary dispersion of the real part(s) - thus describing both lossless...... with a magnetic loss tangent of 1 and relative permeability of 300 yield Q/e equal 65% of the Chu lower bound, with a simultaneous e of 71%....
Spherical tokamak development in Brazil
Energy Technology Data Exchange (ETDEWEB)
Ludwig, G.O.; Del Bosco, E.; Ferreira, J.G.; Berni, L.A.; Oliveira, R.M.; Andrade, M.C.R.; Shibata, C.S.; Ueda, M.; Barroso, J.J.; Castro, P.J. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma; Barbosa, L.F.W. [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo; Patire Junior, H. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Div. de Mecanica Espacial e Controle; The high-power microwave sources group
2003-12-01
This paper describes the general characteristics of spherical tokamaks, or spherical tori, with a brief overview of work in this area already performed or in progress at several institutions worldwide. The paper presents also the steps in the development of the ETE (Experimento Tokamak Esferico) project, its research program, technical characteristics and operating conditions as of December, 2002 at the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)
Directory of Open Access Journals (Sweden)
Lijia Wang
2015-01-01
Full Text Available CMR quantification of LV chamber volumes typically and manually defines the basal-most LV, which adds processing time and user-dependence. This study developed an LV segmentation method that is fully automated based on the spatiotemporal continuity of the LV (LV-FAST. An iteratively decreasing threshold region growing approach was used first from the midventricle to the apex, until the LV area and shape discontinued, and then from midventricle to the base, until less than 50% of the myocardium circumference was observable. Region growth was constrained by LV spatiotemporal continuity to improve robustness of apical and basal segmentations. The LV-FAST method was compared with manual tracing on cardiac cine MRI data of 45 consecutive patients. Of the 45 patients, LV-FAST and manual selection identified the same apical slices at both ED and ES and the same basal slices at both ED and ES in 38, 38, 38, and 41 cases, respectively, and their measurements agreed within -1.6±8.7 mL, -1.4±7.8 mL, and 1.0±5.8% for EDV, ESV, and EF, respectively. LV-FAST allowed LV volume-time course quantitatively measured within 3 seconds on a standard desktop computer, which is fast and accurate for processing the cine volumetric cardiac MRI data, and enables LV filling course quantification over the cardiac cycle.
Sack, Kevin L.; Baillargeon, Brian; Acevedo-Bolton, Gabriel; Genet, Martin; Rebelo, Nuno; Kuhl, Ellen; Klein, Liviu; Weiselthaler, Georg M.; Burkhoff, Daniel; Franz, Thomas; Guccione, Julius M.
2016-01-01
Purpose: Heart failure is a worldwide epidemic that is unlikely to change as the population ages and life expectancy increases. We sought to detail significant recent improvements to the Dassault Systèmes Living Heart Model (LHM) and use the LHM to compute left ventricular (LV) and right ventricular (RV) myofiber stress distributions under the following 4 conditions: (1) normal cardiac function; (2) acute left heart failure (ALHF); (3) ALHF treated using an LV assist device (LVAD) flow rate o...
Estimation of Maximum Allowable PV Connection to LV Residential Power Networks
DEFF Research Database (Denmark)
Demirok, Erhan; Sera, Dezso; Teodorescu, Remus
2011-01-01
Maximum photovoltaic (PV) hosting capacity of low voltage (LV) power networks is mainly restricted by either thermal limits of network components or grid voltage quality resulted from high penetration of distributed PV systems. This maximum hosting capacity may be lower than the available solar...... potential of geographic area due to power network limitations even though all rooftops are fully occupied with PV modules. Therefore, it becomes more of an issue to know what exactly limits higher PV penetration level and which solutions should be engaged efficiently such as over sizing distribution...
The B → D*lv form factor at zero recoil
International Nuclear Information System (INIS)
Simone, J.N.; Hashimoto, S.; El-Khadra, A.X.; Kronfeld, A.S.; Mackenzie, P.B.; Ryan, S.M.
2000-01-01
We describe a model independent lattice QCD method for determining the deviation from unity for h A1 (1), the B → D*lv form factor at zero recoil. We extend the double ratio method previously used to determine the B → Dlv form factor. The bulk of statistical and systematic errors cancel in the double ratios we consider, yielding form factors which promise to reduce present theoretical uncertainties in the determination of parallel V cb parallel. We present results from a prototype calculation at a single lattice spacing corresponding to β = 5.7
Voltage regulation in LV grids by coordinated volt-var control strategies
DEFF Research Database (Denmark)
Juamperez Goñi, Miguel Angel; Yang, Guangya; Kjær, Søren Bækhøj
2014-01-01
in a representative LV network in Bornholm Island using a multi-objective genetic algorithm. The approach is to increase the reactive power contribution of the inverters closest to the transformer during overvoltage conditions. Two standard reactive power control concepts, cosΦ(P) and Q(U), are simulated and compared...... in terms of network power losses and voltage level along the feeder. As a practical implementation, a reconfigurable hardware is used for developing a testing platform based on real-time measurements to regulate the reactive power level. The proposed testing platform has been developed within PVNET...
Nearly collisionless spherical accretion
International Nuclear Information System (INIS)
Begelman, M.C.
1977-01-01
A fluid-like gas accretes much more efficiently than a collisionless gas. The ability of an accreting gas to behave like a fluid depends on the relationship of the mean free path of a gas particle at r → infinity lambdasub(infinity), to the typical length scales associated with the star-gas system. This relationship is examined in detail. For constant collision cross-section evidence is found for a rapid changeover from collisionless to fluid-like accretion flow when lambdasub(infinity) drops below a certain value, but for hard Coulomb collisions, the transition is more gradual, and is sensitive to the adiabatic index of the gas at r→ infinity. To these results must be added the effects of the substantial cusp of bound particles, which always develops in a system with arbitrarily small but non-zero cross-section. The density run in such a cusp depends on the collision properties of the particles. 'Loss-cone' accretion from the cusp may in some cases exceed the predicted accretion rate. (author)
Yeon, Susan B; Salton, Carol J; Gona, Philimon; Chuang, Michael L; Blease, Susan J; Han, Yuchi; Tsao, Connie W; Danias, Peter G; Levy, Daniel; O'Donnell, Christopher J; Manning, Warren J
2015-04-01
To determine normative values for left ventricular (LV) volumes, mass, concentricity, and ejection fraction (EF) and investigate associations between sex, age, and body size with LV parameters in community-dwelling adults. In all, 1794 Framingham Heart Study Offspring cohort members underwent LV short-axis oriented, contiguous multislice cine steady-state free precession MR of the left ventricle; from these a healthy referent group (n = 852, 61 ± 9 years, 40% men) free of clinical cardiac disease and hypertension (SBP 65 years); LV parameters were indexed to measures of body size. Men have greater LV volumes and mass than women both before and after indexation to height, powers of height, and body surface area (P J. Magn. Reson. Imaging 2015;41:1038-1045. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.
Spherical Demons: Fast Surface Registration
Yeo, B.T. Thomas; Sabuncu, Mert; Vercauteren, Tom; Ayache, Nicholas; Fischl, Bruce; Golland, Polina
2009-01-01
We present the fast Spherical Demons algorithm for registering two spherical images. By exploiting spherical vector spline interpolation theory, we show that a large class of regularizers for the modified demons objective function can be efficiently implemented on the sphere using convolution. Based on the one parameter subgroups of diffeomorphisms, the resulting registration is diffeomorphic and fast – registration of two cortical mesh models with more than 100k nodes takes less than 5 minutes, comparable to the fastest surface registration algorithms. Moreover, the accuracy of our method compares favorably to the popular FreeSurfer registration algorithm. We validate the technique in two different settings: (1) parcellation in a set of in-vivo cortical surfaces and (2) Brodmann area localization in ex-vivo cortical surfaces. PMID:18979813
Surface glycosaminoglycans mediate adherence between HeLa cells and Lactobacillus salivarius Lv72.
Martín, Rebeca; Martín, Carla; Escobedo, Susana; Suárez, Juan E; Quirós, Luis M
2013-09-17
The adhesion of lactobacilli to the vaginal surface is of paramount importance to develop their probiotic functions. For this reason, the role of HeLa cell surface proteoglycans in the attachment of Lactobacillus salivarius Lv72, a mutualistic strain of vaginal origin, was investigated. Incubation of cultures with a variety of glycosaminoglycans (chondroitin sulfate A and C, heparin and heparan sulfate) resulted in marked binding interference. However, no single glycosaminoglycan was able to completely abolish cell binding, the sum of all having an additive effect that suggests cooperation between them and recognition of specific adhesins on the bacterial surface. In contrast, chondroitin sulfate B enhanced cell to cell attachment, showing the relevance of the stereochemistry of the uronic acid and the sulfation pattern on binding. Elimination of the HeLa surface glycosaminoglycans with lyases also resulted in severe adherence impairment. Advantage was taken of the Lactobacillus-glycosaminoglycans interaction to identify an adhesin from the bacterial surface. This protein, identify as a soluble binding protein of an ABC transporter system (OppA) by MALDI-TOF/(MS), was overproduced in Escherichia coli, purified and shown to interfere with L. salivarius Lv72 adhesion to HeLa cells. These data suggest that glycosaminoglycans play a fundamental role in attachment of mutualistic bacteria to the epithelium that lines the cavities where the normal microbiota thrives, OppA being a bacterial adhesin involved in the process.
Biocorrosion of 316LV steel used in oral cavity due to Desulfotomaculum nigrificans bacteria.
Mystkowska, Joanna; Ferreira, Jose A; Leszczyńska, Katarzyna; Chmielewska, Sylwia; Dąbrowski, Jan Ryszard; Wieciński, Piotr; Kurzydłowski, Krzysztof Jan
2017-01-01
Corrosion processes of metallic biomaterials in the oral cavity pose a significant limitation to the life and reliable functioning of dental materials. In this article, the influence of environment bacteria Desulfotomaculum nigrificans sulfate reducing bacteria on the corrosion processes of 316LV steel was assessed. After 14 and 28 days of contact of the material with the bacterial environment, the surfaces of the tested biomaterial were observed by means of confocal scanning laser microscopy, and their chemical composition was studied using X-Ray Photoelectron Spectrometry and a scanning transmission electron microscopy. Corrosive changes, the presence of sulfur (with atomic concentration of 0.5%) on the surface of the biomaterial and the presence of a thin oxide layer (thickness of ∼20 nm) under the surface of the steel were observed. This corrosion layer with significant size reduction of grains was characterized by an increased amount of oxygen (18% mas., p < 0.001) in comparison to untreated 316LV steel (where oxygen concentration - 10% mas.). Image analysis conducted using APHELION software indicated that corrosion pits took up ∼2.8% of the total tested surface. The greatest number of corrosion pits had a surface area within the range of 100-200 μm 2 . © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 222-229, 2017. © 2015 Wiley Periodicals, Inc.
Design and Transmission Analysis of an Asymmetrical Spherical Parallel Manipulator
DEFF Research Database (Denmark)
Wu, Guanglei; Caro, Stéphane; Wang, Jiawei
2015-01-01
analysis and optimal design of the proposed manipulator based on its kinematic analysis. The input and output transmission indices of the manipulator are defined for its optimum design based on the virtual coefficient between the transmission wrenches and twist screws. The sets of optimal parameters......This paper presents an asymmetrical spherical parallel manipulator and its transmissibility analysis. This manipulator contains a center shaft to both generate a decoupled unlimited-torsion motion and support the mobile platform for high positioning accuracy. This work addresses the transmission...... are identified and the distribution of the transmission index is visualized. Moreover, a comparative study regarding to the performances with the symmetrical spherical parallel manipulators is conducted and the comparison shows the advantages of the proposed manipulator with respect to its spherical parallel...
Benazepril inhibited the NF-κB and TGF-β networking on LV hypertrophy in rats.
Yan, Shi-Hai; Zhao, Ning-Wei; Zhu, Xuan-Xuan; Wang, Qiong; Wang, Hai-Dan; Fu, Rui; Sun, Yuan; Li, Qi-Yi
2013-05-01
Benazepril, an angiotensin-converting enzyme (ACE) inhibitor, has been used to treat hypertension, congestive heart failure, and chronic renal failure. However, its biological activity and mechanism of action in inflammation are not fully identified. The present study was designed to determine the in vivo anti-inflammatory effects of benazepril on LV hypertrophy in rats. LV hypertrophy was produced in rats by abdominal aortic coarctation. They were then divided into the following groups: sham operation; LV hypertrophy; LV hypertrophy+benazepril (1mg/kg in a gavage, once a day for 4 weeks). Both morphological assays (hemodynamic and hemorheological measurement; LV hypertrophy assessment), and molecular assays (protein levels of Collagen type I/III, TNF-α and VCAM-1; TGF-β gene expression; NF-κB or Smad activation; intracellular ROS production) were performed. The following effects were observed in rats treated with benazepril: (1) marked improvements in hemodynamic and hemorheological parameters; (2) significant reductions in LV hypertrophy, dilatation and fibrosis; (3) significantly attenuated protein levels of Collagen type I/III, TGF-β, TNF-α and VCAM-1, NF-κB or Smad activation, as well as intracellular ROS production. These results suggest that the anti-inflammatory properties of benazepril may be ascribed to their down-regulation of both NF-κB and TGF-β signaling pathways by acting on the intracellular ROS production in rats with LV hypertrophy, thus supporting the use of benazepril as an anti-inflammatory agent. Copyright © 2013 Elsevier B.V. All rights reserved.
Trapped surfaces in spherical stars
International Nuclear Information System (INIS)
Bizon, P.; Malec, E.; O'Murchadha, N.
1988-01-01
We give necessary and sufficient conditions for the existence of trapped surfaces in spherically symmetric spacetimes. These conditions show that the formation of trapped surfaces depends on both the degree of concentration and the average flow of the matter. The result can be considered as a partial validation of the cosmic-censorship hypothesis
Spherical Pendulum, Actions, and Spin
Richter, Peter H.; Dullin, Holger R.; Waalkens, Holger; Wiersig, Jan
1996-01-01
The classical and quantum mechanics of a spherical pendulum are worked out, including the dynamics of a suspending frame with moment of inertia θ. The presence of two separatrices in the bifurcation diagram of the energy-momentum mapping has its mathematical expression in the hyperelliptic nature of
Laplacian eigenmodes for spherical spaces
International Nuclear Information System (INIS)
Lachieze-Rey, M; Caillerie, S
2005-01-01
The possibility that our space is multi-rather than singly-connected has gained renewed interest after the discovery of the low power for the first multipoles of the CMB by WMAP. To test the possibility that our space is a multi-connected spherical space, it is necessary to know the eigenmodes of such spaces. Except for lens and prism space, and to some extent for dodecahedral space, this remains an open problem. Here we derive the eigenmodes of all spherical spaces. For dodecahedral space, the demonstration is much shorter, and the calculation method much simpler than before. We also apply our method to tetrahedric, octahedric and icosahedric spaces. This completes the knowledge of eigenmodes for spherical spaces, and opens the door to new observational tests of the cosmic topology. The vector space V k of the eigenfunctions of the Laplacian on the 3-sphere S 3 , corresponding to the same eigenvalue λ k = -k(k + 2), has dimension (k + 1) 2 . We show that the Wigner functions provide a basis for such a space. Using the properties of the latter, we express the behaviour of a general function of V k under an arbitrary rotation G of SO(4). This offers the possibility of selecting those functions of V k which remain invariant under G. Specifying G to be a generator of the holonomy group of a spherical space X, we give the expression of the vector space V x k of the eigenfunctions of X. We provide a method to calculate the eigenmodes up to an arbitrary order. As an illustration, we give the first modes for the spherical spaces mentioned
Current status of the Citrus leprosis virus (CiLV -C and its vector Brevipalpus phoenicis (Geijskes
Directory of Open Access Journals (Sweden)
Guillermo León M
2012-08-01
Full Text Available The Citrus leprosis virus CiLV-C is a quarantine disease of economic importance. Over the past 15 years, this disease has spread to several countries of Central and South America. Colombia has about 45,000 hectares of citrus planted with an annual production of 750,000 tonnes. The CiLV-C has only been detected in the departments of Meta, Casanare and recently Tolima. Meta has 4,300 hectares representing 10% of the national cultivated area, and Casanare, where CiLV-C appeared in 2004, has no more than 500 ha planted with citrus. The presence of the Citrus leprosis virus in Colombia could affect the international market for citrus, other crops and ornamental plants with the United States and other countries without the disease. The false spider mite Brevipalpus phoenicis (Geijskes (Acari: Tenuipalpidae is the main vector of the CiLV-C. Disease management is based on control programs of the vector and diminishing host plants. Chemical mite control is expensive, wasteful and generates resistance to different acaricides. This paper provides basic information on CiLV-C and its vector, advances in diagnosis and methods to control the disease and prevention of its spread
BezRindas.lv biļešu tirdzniecības Android lietotne
Upītis, Reinis
2014-01-01
Kvalifikācijas darbā tiek aprakstīta autobusu biļešu tirdzniecības lietotne, kas ir paredzēta viedtālruņiem ar Android operētājsistēmu. Mobilā lietotne paredzēta kā papildinājums jau esošam servisam – Bezrindas.lv. Aprakstītās sistēmas izveide atvieglotu biļešu iegādi lietotājiem, kas to vēlētos darīt ar saviem viedtālruņiem.
Efficient Control of Active Transformers for Increasing the PV Hosting Capacity of LV Grids
DEFF Research Database (Denmark)
Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob; Degner, Thomas
2016-01-01
. The potential interferences between the operation of active transformers and the reactive power absorption by PV inverters are investigated, and a voltage droop control approach is proposed for the efficient control of these transformers during high PV generation periods. The proposed method can potentially...... increase the PV hosting capacity of the grid, while eliminating the need for a complex and centralized controller. The voltages of specific locations or the grid state estimations provide adequate data for adjustments of the droop parameters. The simulations and field test results associated...... with the implementation of the proposed method to a newly developed active LV grid with high PV penetration in Felsberg, Germany, confirm the efficiency of the proposed method....
Evolution of the Nova Vulpeculae no.1 1968 (LV Vul) spectrum after the maximum brightness
International Nuclear Information System (INIS)
Andrijya, I.; Antipova, L.I.; Babaev, M.B.; AN Azerbajdzhanskoj SSR, Baku. Shemakhinskaya Astrofizicheskaya Observatoriya)
1986-01-01
The analysis of the spectral evolution of LV Vulpeculae 1968 after the maximum brightness was carried out. It is shown that the pre-maximum spectrum was replaced by the principal one in less than 24sup(h). The diffuse enhanced scectrum and the Orion one existed already when the Nova brightness has decreased only by 0.4sup(m) and 0.5sup(m) respectively. The radial velocities of the Orion spectrum coincided with those of the diffuse enhanced one during the total observational period. The Orion spectrum consists of the lines of He I, N2, O 2 and may be H 1. The appearance of two additional components is probably due to splitting of the principal and diffuse enhanced spectrum
Impact of Distributed Generation Grid Code Requirements on Islanding Detection in LV Networks
Directory of Open Access Journals (Sweden)
Fabio Bignucolo
2017-01-01
Full Text Available The recent growing diffusion of dispersed generation in low voltage (LV distribution networks is entailing new rules to make local generators participate in network stability. Consequently, national and international grid codes, which define the connection rules for stability and safety of electrical power systems, have been updated requiring distributed generators and electrical storage systems to supply stabilizing contributions. In this scenario, specific attention to the uncontrolled islanding issue has to be addressed since currently required anti-islanding protection systems, based on relays locally measuring voltage and frequency, could no longer be suitable. In this paper, the effects on the interface protection performance of different LV generators’ stabilizing functions are analysed. The study takes into account existing requirements, such as the generators’ active power regulation (according to the measured frequency and reactive power regulation (depending on the local measured voltage. In addition, the paper focuses on other stabilizing features under discussion, derived from the medium voltage (MV distribution network grid codes or proposed in the literature, such as fast voltage support (FVS and inertia emulation. Stabilizing functions have been reproduced in the DIgSILENT PowerFactory 2016 software environment, making use of its native programming language. Later, they are tested both alone and together, aiming to obtain a comprehensive analysis on their impact on the anti-islanding protection effectiveness. Through dynamic simulations in several network scenarios the paper demonstrates the detrimental impact that such stabilizing regulations may have on loss-of-main protection effectiveness, leading to an increased risk of unintentional islanding.
Directory of Open Access Journals (Sweden)
HAKAN SARITAŞ
2013-06-01
Full Text Available Proponents of the efficient market hypothesis believe that active portfolio management is largely wasted effort and unlikely to justify the expenses incurred. Therefore, they advocate a passive investment strategy that makes no attempt to outsmart the market. One common strategy for passive management is indexing where a fund is designed to replicate the performance of a broad-based index of stocks and bonds. Traditionally, indexing was used by institutional investors, but today, the use of index funds proliferated among individual investors. Over the years, both international and domestic index funds have disproportionately outperformed the market more than the actively managed funds have.
Development of tools to manage the operational monitoring and pre-design of the NPP-LV cycle
International Nuclear Information System (INIS)
Perusquia, R.; Arredondo S, C.; Hernandez M, J. L.; Montes T, J. L.; Castillo M, A.; Ortiz S, J. J.
2015-09-01
This paper presents the development of tools to facilitate the management so much, the operational monitoring of boiling water reactors (BWR) of the nuclear power plant of Laguna Verde (NPP-LV) through independent codes, and how to carry out the static calculations corresponding to process of optimized pre-design of the reference cycle next to current cycle. The progress and preliminary results obtained with the program SACal, developed at Instituto Nacional de Investigaciones Nucleares (ININ), central tool to achieve provide a management platform of the operational monitoring and pre-design of NPP-LV cycle are also described. The reached preliminary advances directed to get an Analysis center and automated design of fuel assembly cells are also presented, which together with centers or similar modules related with the fuel reloads form the key part to meet the targets set for the realization of a Management Platform of Nuclear Fuel of the NPP-LV. (Author)
Developement of Spherical Polyurethane Beads
Institute of Scientific and Technical Information of China (English)
K. Maeda; H. Ohmori; H. Gyotoku
2005-01-01
@@ 1Results and Discussion We established a new method to produce the spherical polyurethane beads which have narrower distribution of particle size. This narrower distribution was achieved by the polyurethane prepolymer which contains ketimine as a blocked chain-extending agent. Firstly, the prepolymer is dispersed into the aqueous solution containing surfactant. Secondaly, water comes into the inside of prepolymer as oil phase. Thirdly, ketimine is hydrolyzed to amine, and amine reacts with prepolymer immediately to be polyurethane.Our spherical polyurethane beads are very suitable for automotive interior parts especially for instrument panel cover sheet producing under the slush molding method, because of good process ability, excellent durability to the sunlight and mechanical properties at low temperature. See Fig. 1 ,Fig. 2 and Fig. 3 (Page 820).
Contractions of affine spherical varieties
International Nuclear Information System (INIS)
Arzhantsev, I V
1999-01-01
The language of filtrations and contractions is used to describe the class of G-varieties obtainable as the total spaces of the construction of contraction applied to affine spherical varieties, which is well-known in invariant theory. These varieties are local models for arbitrary affine G-varieties of complexity 1 with a one-dimensional categorical quotient. As examples, reductive algebraic semigroups and three-dimensional SL 2 -varieties are considered
Spherical subsystem of galactic radiosources
Energy Technology Data Exchange (ETDEWEB)
Gorshkov, A G; Popov, M V [Moskovskij Gosudarstvennyj Univ. (USSR). Gosudarstvennyj Astronomicheskij Inst. ' ' GAISh' '
1975-05-01
The concentration of statistically complete sampling radiosources of the Ohiof scanning with plane spectra towards the Galaxy centre has been discovered. Quantitative calculations have showed that the sources form a spheric subsystem, which is close in parameters to such old formations in the Galaxy as globular clusters and the RRLsub(YR) type stars. The luminosity of the galaxy spheric subsystem object equals 10/sup 33/ erg/sec, the total number of objects being 7000. The existence of such a subsystem explains s the anomalously by low incline of statistics lgN-lgS in HF scanning PKS (..gamma..-2700Mgz) and the Michigan University scanning (..gamma..=8000Mgz) because the sources of galaxy spheric subsystem make up a considerable share in the total number of sources, especially at high frequencies (50% of sources with a flux greater than a unit of flux per 8000Mgz). It is very probable that the given subsystem consists of the representatives of one of the following class of objects: a) heat sources - the H2H regions with T=10/sup 40/K, Nsub(e)=10/sup 3/, l=1 ps b) supermass black holes with mass M/Mo approximately 10/sup 5/.
Xie, Shijun; Li, Fuhua; Zhang, Xiaojun; Zhang, Jiquan; Xiang, Jianhai
2017-11-01
The peritrophic membrane plays an important role in the defense system of the arthropod gut. The digestive tract is considered one of the major tissues targeted by white spot syndrome virus (WSSV) in shrimp. In this study, the nucleotide sequence encoding peritrophin-like protein of Litopenaeus vannamei (LvPT) was amplified from a yeast two-hybrid library of L. vannamei. The epitope peptide of LvPT was predicted with the GenScript OptimumAntigen™ design tool. An anti-LvPT polyclonal antibody was produced and shown to specifically bind a band at 27 kDa, identified as LvPT. The LvPT protein was expressed and its concentration determined. LvPT dsRNA (4 μg per shrimp) was used to inhibit LvPT expression in shrimp, and a WSSV challenge experiment was then performed with reverse gavage. The pleopods, stomachs, and guts were collected from the shrimp at 0, 24, 48, and 72 h post-infection (hpi). Viral load quantification showed that the levels of WSSV were significantly lower in the pleopods, stomachs, and guts of shrimp after LvPT dsRNA interference than in those of the controls at 48 and 72 hpi. Our results imply that LvPT plays an important role during WSSV infection of the digestive tract.
Munro, Hannah J; Berghuis, Lesley; Lang, Andrew S; Rogers, Laura; Whitney, Hugh
2014-04-01
Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses found within domestic and wild cat populations. These viruses cause severe illnesses that eventually lead to death. Housing cats communally for long periods of time makes shelters at high risk for virus transmission among cats. We tested 548 cats from 5 different sites across the island of Newfoundland for FIV and FeLV. The overall seroprevalence was 2.2% and 6.2% for FIV and FeLV, respectively. Two sites had significantly higher seroprevalence of FeLV infection than the other 3 sites. Analysis of sequences from the FeLV env gene (envelope gene) from 6 positive cats showed that 4 fell within the FeLV subtype-A, while 2 sequences were most closely related to FeLV subtype-B and endogenous feline leukemia virus (en FeLV). Varying seroprevalence and the variation in sequences at different sites demonstrate that some shelters are at greater risk of FeLV infections and recombination can occur at sites of high seroprevalence.
Bolin, Lisa L; Ahmad, Shamim; Levy, Laura S
2011-10-15
Feline leukemia virus (FeLV) is a natural retrovirus of domestic cats associated with degenerative, proliferative and malignant diseases. Studies of FeLV infection in a cohort of naturally infected cats were undertaken to examine FeLV variation, the selective pressures operative in FeLV infection that lead to predominance of natural variants, and the consequences for infection and disease progression. A unique variant, designated FeLV-945, was identified as the predominant isolate in the cohort and was associated with non-T-cell diseases including multicentric lymphoma. FeLV-945 was assigned to the FeLV-A subgroup based on sequence analysis and receptor utilization, but was shown to differ in sequence from a prototype member of FeLV-A, designated FeLV-A/61E, in the long terminal repeat (LTR) and the surface glycoprotein gene (SU). A unique sequence motif in the FeLV-945 LTR was shown to function as a transcriptional enhancer and to confer a replicative advantage. The FeLV-945 SU protein was observed to differ in sequence as compared to FeLV-A/61E within functional domains known to determine receptor selection and binding. Experimental infection of newborn cats was performed using wild type FeLV-A/61E or recombinant FeLV-A/61E in which the LTR (61E/945L) or LTR and SU (61E/945SL) were exchanged for that of FeLV-945. Infection with either FeLV-A/61E or 61E/945L resulted in T-cell lymphoma of the thymus, although 61E/945L caused disease significantly more rapidly. In contrast, infection with 61E/945SL resulted in the rapid induction of a multicentric lymphoma of B-cell origin, thus recapitulating the outcome of natural infection and implicating FeLV-945 SU as a determinant of disease outcome. Recombinant FeLV-B was detected infrequently and at low levels in multicentric lymphomas, and was thereby not implicated in disease induction. Preliminary studies of receptor interaction indicated that virus particles bearing FeLV-945 SU bind to the FeLV-A receptor more
Modelling wetland-groundwater interactions in the boreal Kälväsvaara esker, Northern Finland
Jaros, Anna; Rossi, Pekka; Ronkanen, Anna-Kaisa; Kløve, Bjørn
2016-04-01
Many types of boreal peatland ecosystems such as alkaline fens, aapa mires and Fennoscandia spring fens rely on the presence of groundwater. In these ecosystems groundwater creates unique conditions for flora and fauna by providing water, nutrients and constant water temperature enriching local biodiversity. The groundwater-peatland interactions and their dynamics are not, however, in many cases fully understood and their measurement and quantification is difficult due to highly heterogeneous structure of peatlands and large spatial extend of these ecosystems. Understanding of these interactions and their changes due to anthropogenic impact on groundwater resources would benefit the protection of the groundwater dependent peatlands. The groundwater-peatland interactions were investigated using the fully-integrated physically-based groundwater-surface water code HydroGeoSphere in a case study of the Kälväsvaara esker aquifer, Northern Finland. The Kälväsvaara is a geologically complex esker and it is surrounded by vast aapa mire system including alkaline and springs fens. In addition, numerous small springs occur in the discharge zone of the esker. In order to quantify groundwater-peatland interactions a simple steady-state model was built and results were evaluated using expected trends and field measurements. The employed model reproduced relatively well spatially distributed hydrological variables such as soil water content, water depths and groundwater-surface water exchange fluxes within the wetland and esker areas. The wetlands emerged in simulations as a result of geological and topographical conditions. They could be identified by high saturation levels at ground surface and by presence of shallow ponded water over some areas. The model outputs exhibited also strong surface water-groundwater interactions in some parts of the aapa system. These areas were noted to be regions of substantial diffusive groundwater discharge by the earlier studies. In
Tattiyapong, Puntanat; Dachavichitlead, Worawan; Surachetpong, Win
2017-08-01
Since 2015, a novel orthomyxo-like virus, tilapia lake virus (TiLV) has been associated with outbreaks of disease and massive mortality of cultured Nile and red tilapia (Oreochromis niloticus and Oreochromis spp., respectively) in Thailand. In this study, TiLV was isolated from field samples and propagated in the permissive E-11 cell line, with cytopathic effect (CPE) development within 3-5days post-inoculation. Electron micrographs of infected E-11 cells and fish tissues confirmed the rounded, enveloped virions of 60 to 80nm with characteristics very similar to those of Orthomyxoviridae. In vivo challenge studies showed that high mortality in Nile (86%) and red tilapia (66%) occurred within 4-12days post-infection. The virus was re-isolated from challenged fish tissues in the permissive cell line, and PCR analysis confirmed TiLV as a causative pathogen. The distinct histopathology of challenged fish included massive degeneration and inflammatory cell infiltration in the liver and brain as well as the presence of eosinophilic intracytoplasmic inclusions in hepatocytes and splenic cells. Our results fulfilled Koch's postulates and confirmed that TiLV is an etiologic agent of mass mortality of tilapia in Thailand. The emergence of this virus in many countries has helped increase awareness that it is a potential threat to tilapia aquacultured in Thailand, Asia, and worldwide. Copyright © 2017 Elsevier B.V. All rights reserved.
A Spherical Aerial Terrestrial Robot
Dudley, Christopher J.
This thesis focuses on the design of a novel, ultra-lightweight spherical aerial terrestrial robot (ATR). The ATR has the ability to fly through the air or roll on the ground, for applications that include search and rescue, mapping, surveillance, environmental sensing, and entertainment. The design centers around a micro-quadcopter encased in a lightweight spherical exoskeleton that can rotate about the quadcopter. The spherical exoskeleton offers agile ground locomotion while maintaining characteristics of a basic aerial robot in flying mode. A model of the system dynamics for both modes of locomotion is presented and utilized in simulations to generate potential trajectories for aerial and terrestrial locomotion. Details of the quadcopter and exoskeleton design and fabrication are discussed, including the robot's turning characteristic over ground and the spring-steel exoskeleton with carbon fiber axle. The capabilities of the ATR are experimentally tested and are in good agreement with model-simulated performance. An energy analysis is presented to validate the overall efficiency of the robot in both modes of locomotion. Experimentally-supported estimates show that the ATR can roll along the ground for over 12 minutes and cover the distance of 1.7 km, or it can fly for 4.82 minutes and travel 469 m, on a single 350 mAh battery. Compared to a traditional flying-only robot, the ATR traveling over the same distance in rolling mode is 2.63-times more efficient, and in flying mode the system is only 39 percent less efficient. Experimental results also demonstrate the ATR's transition from rolling to flying mode.
Cooperative effects in spherical spasers
DEFF Research Database (Denmark)
Bordo, Vladimir
2017-01-01
A fully analytical semiclassical theory of cooperative optical processes which occur in an ensemble of molecules embedded in a spherical core-shell nanoparticle is developed from first principles. Both the plasmonic Dicke effect and spaser generation are investigated for the designs in which...... a shell/core contains an arbitrarily large number of active molecules in the vicinity of a metallic core/shell. An essential aspect of the theory is an ab initio account of the feedback from the core/shell boundaries which significantly modifies the molecular dynamics. The theory provides rigorous, albeit...
Spherical bodies of constant width
Lassak, Marek; Musielak, Michał
2018-01-01
The intersection $L$ of two different non-opposite hemispheres $G$ and $H$ of a $d$-dimensional sphere $S^d$ is called a lune. By the thickness of $L$ we mean the distance of the centers of the $(d-1)$-dimensional hemispheres bounding $L$. For a hemisphere $G$ supporting a %spherical convex body $C \\subset S^d$ we define ${\\rm width}_G(C)$ as the thickness of the narrowest lune or lunes of the form $G \\cap H$ containing $C$. If ${\\rm width}_G(C) =w$ for every hemisphere $G$ supporting $C$, we...
International Nuclear Information System (INIS)
Ionescu-Pallas, N.; Vlad, V.I.
1999-01-01
The spectrum of black body radiation at the absolute temperature T, in an ideal spherical cavity of radius R, is studied. The departures from the classical predictions of Planck's theory, due to the discrete energies of the radiation quanta confined inside the cavity, depend on the adiabatic invariant RT and are significant for RT≤ 1 cm K. Special attention was paid to evidence sudden changes in the spectrum intensities, forbidden bands of frequency, as well as major modifications of the total energy for RT≤ 1 cm K. Similar effects were present in case of a cubic cavity too. (authors)
Impact of biogenic nanoscale metals Fe, Cu, Zn and Se on reproductive LV chickens
International Nuclear Information System (INIS)
Nguyen, Quy Khiem; Nguyen, Van Kien; Nguyen, Khac Thinh; Nguyen, Duy Dieu; Nguyen, Hoai Chau; Tran, Xuan Tin; Nguyen, Huu Cuong; Phung, Duc Tien
2015-01-01
Using biogenic nanoscale metals (Fe, Cu, ZnO, Se) to supplement into diet premix of reproductive LV (a Vietnamese Luong Phuong chicken breed) chickens resulted in certain improvement of poultry farming. The experimental data obtained showed that the farming indices depend mainly on the quantity of nanocrystalline metals which replaced the inorganic mineral component in the feed premix. All four experimental groups with different quantities of the replacement nano component grew and developed normally with livability reaching 91 to 94%, hen’s bodyweight at 38 weeks of age and egg weight ranged from 2.53–2.60 kg/hen and 50.86–51.55 g/egg, respectively. All these farming indices together with laying rate, egg productivity and chick hatchability peaked at group 5 with 25% of nanoscale metals compared to the standard inorganic mineral supplement, while feed consumption was lowest. The results also confirmed that nanocrystalline metals Fe, Cu, ZnO and Se supplemented to chicken feed were able to decrease inorganic minerals in the diet premixes at least four times, allowing animals to more effectively absorb feed minerals, consequently decreasing environmental pollution risks. (paper)
Interactions between charged spherical macroions
International Nuclear Information System (INIS)
Stevens, M.J.; Falk, M.L.; Robbins, M.O.
1996-01-01
Monte Carlo (MC) simulations were used to study the screened interactions between charged spherical macroions surrounded by discrete counterions, and to test previous theories of screening. The simulations were performed in the primitive cell of the bcc lattice, and in the spherical Wigner endash Seitz cell that is commonly used in approximate calculations. We found that the Wigner endash Seitz approximation is valid even at high volume fractions φ and large macroion charges Z, because the macroion charge becomes strongly screened. Pressures calculated from Poisson endash Boltzmann theory and local density functional theory deviate from MC values as φ and Z increase, but continue to provide upper and lower bounds for the MC results. While Debye endash Hueckel (DH) theory fails badly when the bare charge is used, MC pressures can be fit with an effective DH charge, Z DH , that is nearly independent of volume fraction. As Z diverges, Z DH saturates at zψ max R m /λ, where z is the counterion charge, R m is the macroion radius, λ is the Bjerrum length, and ψ max is a constant of order 10. copyright 1996 American Institute of Physics
National Spherical Torus Experiment (NSTX)
International Nuclear Information System (INIS)
Masayuki Ono
2000-01-01
The main aim of National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the innovative spherical torus (ST) concept. Physics outcome of the NSTX research program is relevant to near-term applications such as the Volume Neutron Source (VNS) and burning plasmas, and future applications such as the pilot and power plants. The NSTX device began plasma operations in February 1999 and the plasma current was successfully ramped up to the design value of 1 million amperes (MA) on December 14, 1999. The CHI (Coaxial Helicity Injection) and HHFW (High Harmonic Fast Wave) experiments have also started. Stable CHI discharges of up to 133 kA and 130-msec duration have been produced using 20 kA of injected current. Using eight antennas connected to two transmitters, up to 2 MW of HHFW power was successfully coupled to the plasma. The Neutral-beam Injection (NBI) heating system and associated NBI-based diagnostics such as the Charge-exchange Recombination Spectrometer (CHERS) will be operational in October 2000
Casimir effect in spherical shells
International Nuclear Information System (INIS)
Ruggiero, J.R.
1985-01-01
The analytic regularization method is applied to study the Casimir effect for spherical cavities. Although many works have been presented in the past few years, problems related to the elimination of the regulator parameter still remain. A way to calculate the zero point energy of a perfectly conducting spherical shell which is a miscellaneous of those presented early is here proposed, How a cancelation of divergent terms occurs and how a finite parte is obtained after the elimination of the regulator parameter is shown. As a by-product the zero point energy of the interior vibration modes is obtained and this has some relevance to the quarks bag model. This relev ance is also discussed. The calculation of the energy fom the density view is also discussed. Some works in this field are criticized. The logarithmic divergent terms in the zero point energy are studied when the interior and exterior of the sphere are considered as a medium not dispersive and characterized by a dielectric constants ε 1 and ε 2 and peermeability constants μ 1 and μ 2 respectivelly. The logarithmic divergent terms are not present in the case of ε i μ i =K, with K some constant and i=1,2. (author) [pt
Progress in octahedral spherical hohlraum study
Directory of Open Access Journals (Sweden)
Ke Lan
2016-01-01
Full Text Available In this paper, we give a review of our theoretical and experimental progress in octahedral spherical hohlraum study. From our theoretical study, the octahedral spherical hohlraums with 6 Laser Entrance Holes (LEHs of octahedral symmetry have robust high symmetry during the capsule implosion at hohlraum-to-capsule radius ratio larger than 3.7. In addition, the octahedral spherical hohlraums also have potential superiority on low backscattering without supplementary technology. We studied the laser arrangement and constraints of the octahedral spherical hohlraums, and gave a design on the laser arrangement for ignition octahedral hohlraums. As a result, the injection angle of laser beams of 50°–60° was proposed as the optimum candidate range for the octahedral spherical hohlraums. We proposed a novel octahedral spherical hohlraum with cylindrical LEHs and LEH shields, in order to increase the laser coupling efficiency and improve the capsule symmetry and to mitigate the influence of the wall blowoff on laser transport. We studied on the sensitivity of the octahedral spherical hohlraums to random errors and compared the sensitivity among the octahedral spherical hohlraums, the rugby hohlraums and the cylindrical hohlraums, and the results show that the octahedral spherical hohlraums are robust to these random errors while the cylindrical hohlraums are the most sensitive. Up till to now, we have carried out three experiments on the spherical hohlraum with 2 LEHs on Shenguang(SG laser facilities, including demonstration of improving laser transport by using the cylindrical LEHs in the spherical hohlraums, spherical hohlraum energetics on the SGIII prototype laser facility, and comparisons of laser plasma instabilities between the spherical hohlraums and the cylindrical hohlraums on the SGIII laser facility.
International Nuclear Information System (INIS)
Janowski, M.; Merregaert, J.; Nuyten, J.M.; Maisin, J.R.
1984-01-01
An infectious clone of the linear, unintegrated RadLV provirus was obtained by insertion in the plasmid pBR322. Its restriction map was indistinguishable from that of the majority of the multiple proviral copies, which are found apparently at random sites in the DNA of RadLV-induced rat thymic lymphomas [fr
Chuang, Michael L.; Gona, Philimon; Hautvast, Gilion L T F; Salton, Carol J.; Blease, Susan J.; Yeon, Susan B.; Breeuwer, Marcel; O'Donnell, Christopher J.; Manning, Warren J.
2012-01-01
Objectives: The goal of this study was to assess the relationship of left ventricular (LV) trabeculae and papillary muscles (TPM) with clinical characteristics in a community-based, free-living adult cohort and to determine the effect of TPM on quantitative measures of LV volume, mass, and ejection
Montoya, Nelson; Reyes, Eduardo
2002-01-01
Acumulación/eliminación de oxitetraciclina en el camarón blanco, LV y su residualidad en dietas artificiales Acumulación/eliminación de oxitetraciclina en el camarón blanco, LV y su residualidad en dietas artificiales
International Nuclear Information System (INIS)
Ali, A.Z.
2007-01-01
Full text: Aim: To compare the perfusion and LV function parameters as quantified by 4D-MSPECT and ECT in the same patient group and a qualitative comparison of the reconstructed slices by two different experts. Materials and methods: Thirty-one consecutive patients underwent gated myocardial perfusion SPECT using a two-day protocol. The gated and ungated data were reconstructed by back projection method. Quantitative analysis was performed on the same set of reconstructed slices by 4D-MSPECT and Emory Cardiac Tool Box. The reconstructed slices were read qualitatively by two different experts on their respective systems. Polar map and functional analysis was performed in both softwares and the results were compared. Results: The concordance between the two experts qualitatively was seen in 78/93(84%) coronary territories. The polar map defects were comparable in LAD (r-value of 0.87) and LCX (r-value of 0.76) territories whereas RCA defects (r-value of 0.04) were not at all correlating. The defect severity showed concordance in 68/93 (73%) coronary territories. There was concordance between 4DMSPECT and the qualitative interpretation in 84/93 (90%) coronary territories whereas ECT showed concordance in only 70/93(75%) coronary territories. The overall sensitivity is marginally higher for ECT (100% vs. 96%) but the overall specificity is much higher with 4 DMSPECT (88% vs. 65%). ESV showed good correlation(r=0.94) of the two softwares with no significant difference in means. EDV and LVEF although had good correlation(r = 0.96 and 0.89) showed high difference in means (p<0.01). Conclusion: Between 4D-MSPECT and ECT, 4D-MSPECT is marginally superior to ECT with reference to qualitative interpretation in view of better specificity. The LVEF values between the two softwares should also not be used interchangeably. (author)
Regulation of FeLV-945 by c-Myb binding and CBP recruitment to the LTR
Directory of Open Access Journals (Sweden)
Finstad Samantha L
2004-09-01
Full Text Available Abstract Background Feline leukemia virus (FeLV induces degenerative, proliferative and malignant hematologic disorders in its natural host, the domestic cat. FeLV-945 is a viral variant identified as predominant in a cohort of naturally infected animals. FeLV-945 contains a unique sequence motif in the long terminal repeat (LTR comprised of a single copy of transcriptional enhancer followed by a 21-bp sequence triplicated in tandem. The LTR is precisely conserved among independent cases of multicentric lymphoma, myeloproliferative disease and anemia in animals from the cohort. The 21-bp triplication was previously shown to act as a transcriptional enhancer preferentially in hematopoietic cells and to confer a replicative advantage. The objective of the present study was to examine the molecular mechanism by which the 21-bp triplication exerts its influence and the selective advantage responsible for its precise conservation. Results Potential binding sites for the transcription factor, c-Myb, were identified across the repeat junctions of the 21-bp triplication. Such sites would not occur in the absence of the repeat; thus, a requirement for c-Myb binding to the repeat junctions of the triplication would exert a selective pressure to conserve its sequence precisely. Electrophoretic mobility shift assays demonstrated specific binding of c-Myb to the 21-bp triplication. Reporter gene assays showed that the triplication-containing LTR is responsive to c-Myb, and that responsiveness requires the presence of both c-Myb binding sites. Results further indicated that c-Myb in complex with the 21-bp triplication recruits the transcriptional co-activator, CBP, a regulator of normal hematopoiesis. FeLV-945 replication was shown to be positively regulated by CBP in a manner dependent on the presence of the 21-bp triplication. Conclusion Binding sites for c-Myb across the repeat junctions of the 21-bp triplication may account for its precise conservation in
Directory of Open Access Journals (Sweden)
Daniella Poffo
Full Text Available ABSTRACT: This search aimed to investigate FIV and FeLV infections in domestic cats, analysing the epidemiological profile of the disease as well as additional infection with Leishmania sp. We evaluated 88 domestic cats for the presence of FIV, FeLV and Leishmania sp. infection. Eleven (12.5% cats were positive for FIV infection, four (4.5% were positive for FeLV, and two were co-infected. However, none was infected with Leishmania sp. The prevalence for FIV infection was higher than FeLV, and those observed in other regions, but no factor was associated with the infection by FIV and FeLV in this study.
The ETE spherical Tokamak project. IAEA report
Energy Technology Data Exchange (ETDEWEB)
Ludwig, Gerson Otto; Del Bosco, E.; Berni, L.A.; Ferreira, J.G.; Oliveira, R.M.; Andrade, M.C.R.; Shibata, C.S.; Barroso, J.J.; Castro, P.J.; Patire Junior, H. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma]. E-mail: ludwig@plasma.inpe.br
2002-07-01
This paper describes the general characteristics of spherical tokamaks, or spherical tori, with a brief overview of work in this area already performed or in progress at several institutions worldwide. The paper presents also the historical development of the ETE (Spherical Tokamak Experiment) project, its research program, technical characteristics and operating conditions as of October, 2002 at the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)
Spherical sila- and germa-homoaromaticity.
Chen, Zhongfang; Hirsch, Andreas; Nagase, Shigeru; Thiel, Walter; Schleyer, Paul von Ragué
2003-12-17
Guided by the 2(N + 1)2 electron-counting rule for spherical aromatic molecules, we have designed various spherical sila- and germa-homoaromatic systems rich in group 14 elements. Their aromaticity is revealed by density-functional computations of their structures and the nucleus-independent chemical shifts (NICS). Besides the formerly used endohedral inclusion strategy, spherical homoaromaticity is another way to stabilize silicon and germanium clusters.
Spherical collapse in chameleon models
International Nuclear Information System (INIS)
Brax, Ph.; Rosenfeld, R.; Steer, D.A.
2010-01-01
We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse in principle depends on the initial comoving size of the inhomogeneity
Spherical collapse in chameleon models
Energy Technology Data Exchange (ETDEWEB)
Brax, Ph. [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Rosenfeld, R. [Instituto de Física Teórica, Universidade Estadual Paulista, Rua Dr. Bento T. Ferraz, 271, 01140-070, São Paulo (Brazil); Steer, D.A., E-mail: brax@spht.saclay.cea.fr, E-mail: rosenfel@ift.unesp.br, E-mail: daniele.steer@apc.univ-paris7.fr [APC, UMR 7164, CNRS, Université Paris 7, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)
2010-08-01
We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse in principle depends on the initial comoving size of the inhomogeneity.
Spherical Collapse in Chameleon Models
Brax, Ph; Steer, D A
2010-01-01
We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse depends on the initial comoving size of the inhomogeneity.
Relativistic fluids in spherically symmetric space
International Nuclear Information System (INIS)
Dipankar, R.
1977-12-01
Some of McVittie and Wiltshire's (1977) solutions of Walker's (1935) isotropy conditions for relativistic perfect fluid spheres are generalized. Solutions are spherically symmetric and conformally flat
Energy Technology Data Exchange (ETDEWEB)
Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2015-03-18
Tests were performed to evaluate a sample conditioning unit for stack monitoring at Hanford Tank Waste Treatment and Immobilization Plant (WTP) exhaust stacks with elevated air temperatures. The LV-S2, LV-S3, HV-S3A and HV-S3B exhaust stacks are expected to have elevated air temperature and dew point. At these emission points, exhaust temperatures are too high to deliver the air sample directly to the required stack monitoring equipment. As a result, a sample conditioning system is considered to cool and dry the air prior to its delivery to the stack monitoring system. The method proposed for the sample conditioning is a dilution system that will introduce cooler, dry air to the air sample stream. This method of sample conditioning is meant to reduce the sample temperature while avoiding condensation of moisture in the sample stream. An additional constraint is that the ANSI/HPS N13.1-1999 standard states that at least 50% of the 10 μm aerodynamic diameter (AD) particles present in the stack free stream must be delivered to the sample collector. In other words, depositional loss of particles should be limited to 50% in the sampling, transport, and conditioning systems. Based on estimates of particle penetration through the LV-S3 sampling system, the diluter should perform with about 80% penetration or better to ensure that the total sampling system passes the 50% or greater penetration criterion.
Information-Quality based LV-Grid-Monitoring Framework and its Application to Power-Quality Control
DEFF Research Database (Denmark)
Findrik, Mislav; Kristensen, Thomas le Fevre; Hinterhofer, Thomas
2015-01-01
The integration of unpredictable renewable energy sources into the low voltage (LV) power grid results in new challenges when it comes to ensuring power quality in the electrical grid. Addressing this problem requires control of not only the secondary substation but also control of flexible assets...... inside the LV grid. In this paper we investigate how the flexibility information of such assets can be accessed by the controller using heterogeneous off-the-shelf communication networks. To achieve this we develop an adaptive monitoring framework, through which the controller can subscribe to the assets......' flexibility information through an API. We define an information quality metric making the monitoring framework able to adapt information access strategies to ensure the information is made available to the controller with the highest possible information quality. To evaluate the monitoring framework...
Acoustic radiation force control: Pulsating spherical carriers.
Rajabi, Majid; Mojahed, Alireza
2018-02-01
The interaction between harmonic plane progressive acoustic beams and a pulsating spherical radiator is studied. The acoustic radiation force function exerted on the spherical body is derived as a function of the incident wave pressure and the monopole vibration characteristics (i.e., amplitude and phase) of the body. Two distinct strategies are presented in order to alter the radiation force effects (i.e., pushing and pulling states) by changing its magnitude and direction. In the first strategy, an incident wave field with known amplitude and phase is considered. It is analytically shown that the zero- radiation force state (i.e., radiation force function cancellation) is achievable for specific pulsation characteristics belong to a frequency-dependent straight line equation in the plane of real-imaginary components (i.e., Nyquist Plane) of prescribed surface displacement. It is illustrated that these characteristic lines divide the mentioned displacement plane into two regions of positive (i.e., pushing) and negative (i.e., pulling) radiation forces. In the second strategy, the zero, negative and positive states of radiation force are obtained through adjusting the incident wave field characteristics (i.e., amplitude and phase) which insonifies the radiator with prescribed pulsation characteristics. It is proved that zero radiation force state occurs for incident wave pressure characteristics belong to specific frequency-dependent circles in Nyquist plane of incident wave pressure. These characteristic circles divide the Nyquist plane into two distinct regions corresponding to positive (out of circles) and negative (in the circles) values of radiation force function. It is analytically shown that the maximum amplitude of negative radiation force is exactly equal to the amplitude of the (positive) radiation force exerted upon the sphere in the passive state, by the same incident field. The developed concepts are much more deepened by considering the required
Stability of the spherical form of nuclei
International Nuclear Information System (INIS)
Sabry, A.A.
1976-08-01
An extension of the mass formula for a spherical nucleus in the drop model to include a largely deformed nucleus of different forms is investigated. It is found that although the spherical form is stable under small deformations from equilibrium, there exists for heavier nuclei another more favourable stable form, which can be approximated by two, or three touching prolate ellipsoids of revolution
How Spherical Is a Cube (Gravitationally)?
Sanny, Jeff; Smith, David
2015-01-01
An important concept that is presented in the discussion of Newton's law of universal gravitation is that the gravitational effect external to a spherically symmetric mass distribution is the same as if all of the mass of the distribution were concentrated at the center. By integrating over ring elements of a spherical shell, we show that the…
Spherical Tensor Calculus for Local Adaptive Filtering
Reisert, Marco; Burkhardt, Hans
In 3D image processing tensors play an important role. While rank-1 and rank-2 tensors are well understood and commonly used, higher rank tensors are rare. This is probably due to their cumbersome rotation behavior which prevents a computationally efficient use. In this chapter we want to introduce the notion of a spherical tensor which is based on the irreducible representations of the 3D rotation group. In fact, any ordinary cartesian tensor can be decomposed into a sum of spherical tensors, while each spherical tensor has a quite simple rotation behavior. We introduce so called tensorial harmonics that provide an orthogonal basis for spherical tensor fields of any rank. It is just a generalization of the well known spherical harmonics. Additionally we propose a spherical derivative which connects spherical tensor fields of different degree by differentiation. Based on the proposed theory we present two applications. We propose an efficient algorithm for dense tensor voting in 3D, which makes use of tensorial harmonics decomposition of the tensor-valued voting field. In this way it is possible to perform tensor voting by linear-combinations of convolutions in an efficient way. Secondly, we propose an anisotropic smoothing filter that uses a local shape and orientation adaptive filter kernel which can be computed efficiently by the use spherical derivatives.
International Nuclear Information System (INIS)
Chen, Chun; Li, Dianfu; Miao, Changqing; Zhou, Yanli; Cao, Kejiang; Feng, Jianlin; Lloyd, Michael S.; Chen, Ji
2012-01-01
The purpose of this study was to evaluate left ventricular (LV) mechanical dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome pre- and post-radiofrequency catheter ablation (RFA) using phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Forty-five WPW patients were enrolled and had gated SPECT MPI pre- and 2-3 days post-RFA. Electrophysiological study (EPS) was used to locate accessory pathways (APs) and categorize the patients according to the AP locations (septal, left and right free wall). Electrocardiography (ECG) was performed pre- and post-RFA to confirm successful elimination of the APs. Phase analysis of gated SPECT MPI was used to assess LV dyssynchrony pre- and post-RFA. Among the 45 patients, 3 had gating errors, and thus 42 had SPECT phase analysis. Twenty-two patients (52.4 %) had baseline LV dyssynchrony. Baseline LV dyssynchrony was more prominent in the patients with septal APs than in the patients with left or right APs (p < 0.05). RFA improved LV synchrony in the entire cohort and in the patients with septal APs (p < 0.01). Phase analysis of gated SPECT MPI demonstrated that LV mechanical dyssynchrony can be present in patients with WPW syndrome. Septal APs result in the greatest degree of LV mechanical dyssynchrony and afford the most benefit after RFA. This study supports further investigation in the relationship between electrical and mechanical activation using EPS and phase analysis of gated SPECT MPI. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Chen, Chun; Li, Dianfu; Miao, Changqing; Zhou, Yanli; Cao, Kejiang [First Affiliated Hospital of Nanjing Medical University, Department of Cardiology, Nanjing, Jiangsu (China); Feng, Jianlin [First Affiliated Hospital of Nanjing Medical University, Department of Nuclear Medicine, Nanjing, Jiangsu (China); Lloyd, Michael S. [Emory University School of Medicine, Division of Cardiology, Atlanta, GA (United States); Chen, Ji [Emory University School of Medicine, Department of Radiology and Imaging Sciences, Atlanta, GA (United States)
2012-07-15
The purpose of this study was to evaluate left ventricular (LV) mechanical dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome pre- and post-radiofrequency catheter ablation (RFA) using phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Forty-five WPW patients were enrolled and had gated SPECT MPI pre- and 2-3 days post-RFA. Electrophysiological study (EPS) was used to locate accessory pathways (APs) and categorize the patients according to the AP locations (septal, left and right free wall). Electrocardiography (ECG) was performed pre- and post-RFA to confirm successful elimination of the APs. Phase analysis of gated SPECT MPI was used to assess LV dyssynchrony pre- and post-RFA. Among the 45 patients, 3 had gating errors, and thus 42 had SPECT phase analysis. Twenty-two patients (52.4 %) had baseline LV dyssynchrony. Baseline LV dyssynchrony was more prominent in the patients with septal APs than in the patients with left or right APs (p < 0.05). RFA improved LV synchrony in the entire cohort and in the patients with septal APs (p < 0.01). Phase analysis of gated SPECT MPI demonstrated that LV mechanical dyssynchrony can be present in patients with WPW syndrome. Septal APs result in the greatest degree of LV mechanical dyssynchrony and afford the most benefit after RFA. This study supports further investigation in the relationship between electrical and mechanical activation using EPS and phase analysis of gated SPECT MPI. (orig.)
Lee, Ji-Hyun; Momani, Jalal; Kim, Young Mog; Kang, Chang-Keun; Choi, Jung-Hwa; Baek, Hae-Ja; Kim, Hyun-Woo
2015-01-01
Myostatin (MSTN), also known as GDF8, is a member of the transforming growth factor-β (TGF-β) superfamily and plays an important role in muscle growth, development, and differentiation. Recently, Lv-MSTN/GDF11, the primitive isoform of MSTN and GDF11, was identified from the shrimp Litopenaeus vannamei. The major production site for Lv-MSTN/GDF11 is in the heart, not the tail muscle, which differs from MSTNs in mammals. Among the three injected RNAs, long dsRNA was the most effective for Lv-MSTN/GDF11 knockdown and transcripts of Lv-MSTN/GDF11 decreased in both the heart (88.85%) and skeletal muscles (43.36%) 72h after injection of 10pmol of long dsRNA. We also found that higher doses of dsRNA did not lead to greater decreases in Lv-MSTN/GDF11 transcripts for amounts between 1pmol and 100pmol. Injection of Lv-MSTN/GDF11 dsRNA did not affect the upregulation of the skeletal actin gene (Lv-ACTINSK) in the tail muscle, but the expression of cytoplasmic and cardiac actins were upregulated in both the heart and tail muscle. Over the course of 8weeks of dsRNA injection, considerably higher mortality (~71%) was seen in the dsRNA-injected group compared to the control group (40%). Surviving shrimp in the dsRNA injected group had a lower growth rate due to the adverse effects of Lv-MSTN/GDF11 knockdown. Lv-MSTN/GDF11 appears to be involved in muscular or neuronal development, but not in doubling muscle fibers, as is the case with mammalian MSTN. Copyright © 2014 Elsevier Inc. All rights reserved.
Electrical properties of spherical syncytia.
Eisenberg, R S; Barcilon, V; Mathias, R T
1979-01-01
Syncytial tissues consist of many cells whose intracellular spaces are electrically coupled one to another. Such tissues typically include narrow, tortuous extracellular space and often have specialized membranes at their outer surface. We derive differential equations to describe the potentials induced when a sinusoidal or steady current is applied to the intracellular space with a microelectrode. We derive solutions for spherical preparations with isotropic properties or with a particular anisotropy in effective extracellular and intracellular resistivities. Solutions are presented in an approximate form with a simple physical interpretation. The leading term in the intracellular potential describes an "isopotential" cell in which there is no spatial variation of intracellular potential. The leading term in the extracellular potential, and thus the potential across the inner membranes, varies with radial position, even at zero frequency. The next term of the potentials describes the direct effects of the point source of current and, for the parameters given here, acts as a series resistance producing a large local potential drop essentially independent of frequency. A lumped equivalent circuit describes the "low frequency" behavior of the syncytium, and a distributed circuit gives a reasonably accurate general description. Graphs of the spatial variation and frequency dependence of intracellular, extracellular, and transmembrane potential are given, the response to sinusoidal currents is used to calculate numerically the response to a step function of current.
Intrinsic cylindrical and spherical waves
International Nuclear Information System (INIS)
Ludlow, I K
2008-01-01
Intrinsic waveforms associated with cylindrical and spherical Bessel functions are obtained by eliminating the factors responsible for the inverse radius and inverse square radius laws of wave power per unit area of wavefront. The resulting expressions are Riccati-Bessel functions for both cases and these can be written in terms of amplitude and phase functions of order v and wave variable z. When z is real, it is shown that a spatial phase angle of the intrinsic wave can be defined and this, together with its amplitude function, is systematically investigated for a range of fixed orders and varying z. The derivatives of Riccati-Bessel functions are also examined. All the component functions exhibit different behaviour in the near field depending on the order being less than, equal to or greater than 1/2. Plots of the phase angle can be used to display the locations of the zeros of the general Riccati-Bessel functions and lead to new relations concerning the ordering of the real zeros of Bessel functions and the occurrence of multiple zeros when the argument of the Bessel function is fixed
Alfven Eigenmodes in spherical tokamaks
International Nuclear Information System (INIS)
Gryaznevich, Mikhail P.; Sharapov, Sergei E.; Berk, Herbert L.; Pinches, Simon D.
2005-01-01
Electromagnetic instabilities are often excited by fast super-Alfvenic ions produced by neutral beam injection (NBI) in plasmas of the spherical tokamaks START and MAST (toroidal magnetic confinement devices in which the minor a and major R 0 radii of the torus are comparable, R 0 /a≅1.2/1.8). These instabilities are seen as discrete weakly-damped toroidal and elliptical Alfven Eigenmodes (TAEs and EAEs) with frequencies tracing in time the Alfven scaling with the equilibrium magnetic field and plasma density, or as energetic particle modes (EPMs) whose frequencies don't start from TAE-frequency and sweep down in time faster than the equilibrium parameters change. In some discharges the beam drives Aflvenic-type modes that start from the TAE frequency and sweep in both up- and down- directions. Such electromagnetic perturbations are interpreted as 'hole-clump' long-living nonlinear fluctuations of the fast ion distribution function predicted by Berk-Breizman-Petviashvili [Phys. Lett. A238 (1998) 408]. It is found on both START and MAST that the Alfven instabilities weaken in their mode amplitude and in the number of unstable modes as the pressure of the thermal plasma increases, in agreement with increased thermal ion Landau damping and the pressure effect on core-localised TAEs. (author)
Spherically symmetric charged compact stars
Energy Technology Data Exchange (ETDEWEB)
Maurya, S.K. [University of Nizwa, Department of Mathematical and Physical Sciences, College of Arts and Science, Nizwa (Oman); Gupta, Y.K. [Jaypee Institute of Information Technology University, Department of Mathematics, Noida, Uttar Pradesh (India); Ray, Saibal [Government College of Engineering and Ceramic Technology, Department of Physics, Kolkata, West Bengal (India); Chowdhury, Sourav Roy [Seth Anandaram Jaipuria College, Department of Physics, Kolkata, West Bengal (India)
2015-08-15
In this article we consider the static spherically symmetric metric of embedding class 1. When solving the Einstein-Maxwell field equations we take into account the presence of ordinary baryonic matter together with the electric charge. Specific new charged stellar models are obtained where the solutions are entirely dependent on the electromagnetic field, such that the physical parameters, like density, pressure etc. do vanish for the vanishing charge. We systematically analyze altogether the three sets of Solutions I, II, and III of the stellar models for a suitable functional relation of ν(r). However, it is observed that only the Solution I provides a physically valid and well-behaved situation, whereas the Solutions II and III are not well behaved and hence not included in the study. Thereafter it is exclusively shown that the Solution I can pass through several standard physical tests performed by us. To validate the solution set presented here a comparison has also been made with that of the compact stars, like RX J 1856 - 37, Her X - 1, PSR 1937+21, PSRJ 1614-2230, and PSRJ 0348+0432, and we have shown the feasibility of the models. (orig.)
Beig, Robert; Siddiqui, Azad A.
2007-11-01
It is known that spherically symmetric static spacetimes admit a foliation by flat hypersurfaces. Such foliations have explicitly been constructed for some spacetimes, using different approaches, but none of them have proved or even discussed the uniqueness of these foliations. The issue of uniqueness becomes more important due to suitability of flat foliations for studying black hole physics. Here, flat spherically symmetric spacelike hypersurfaces are obtained by a direct method. It is found that spherically symmetric static spacetimes admit flat spherically symmetric hypersurfaces, and that these hypersurfaces are unique up to translation under the timelike Killing vector. This result guarantees the uniqueness of flat spherically symmetric foliations for such spacetimes.
Modeling mantle convection in the spherical annulus
Hernlund, John W.; Tackley, Paul J.
2008-12-01
Most methods for modeling mantle convection in a two-dimensional (2D) circular annular domain suffer from innate shortcomings in their ability to capture several characteristics of the spherical shell geometry of planetary mantles. While methods such as rescaling the inner and outer radius to reduce anomalous effects in a 2D polar cylindrical coordinate system have been introduced and widely implemented, such fixes may have other drawbacks that adversely affect the outcome of some kinds of mantle convection studies. Here we propose a new approach that we term the "spherical annulus," which is a 2D slice that bisects the spherical shell and is quantitatively formulated at the equator of a spherical polar coordinate system after neglecting terms in the governing equations related to variations in latitude. Spherical scaling is retained in this approximation since the Jacobian function remains proportional to the square of the radius. We present example calculations to show that the behavior of convection in the spherical annulus compares favorably against calculations performed in other 2D annular domains when measured relative to those in a fully three-dimensional (3D) spherical shell.
Averaging in spherically symmetric cosmology
International Nuclear Information System (INIS)
Coley, A. A.; Pelavas, N.
2007-01-01
The averaging problem in cosmology is of fundamental importance. When applied to study cosmological evolution, the theory of macroscopic gravity (MG) can be regarded as a long-distance modification of general relativity. In the MG approach to the averaging problem in cosmology, the Einstein field equations on cosmological scales are modified by appropriate gravitational correlation terms. We study the averaging problem within the class of spherically symmetric cosmological models. That is, we shall take the microscopic equations and effect the averaging procedure to determine the precise form of the correlation tensor in this case. In particular, by working in volume-preserving coordinates, we calculate the form of the correlation tensor under some reasonable assumptions on the form for the inhomogeneous gravitational field and matter distribution. We find that the correlation tensor in a Friedmann-Lemaitre-Robertson-Walker (FLRW) background must be of the form of a spatial curvature. Inhomogeneities and spatial averaging, through this spatial curvature correction term, can have a very significant dynamical effect on the dynamics of the Universe and cosmological observations; in particular, we discuss whether spatial averaging might lead to a more conservative explanation of the observed acceleration of the Universe (without the introduction of exotic dark matter fields). We also find that the correlation tensor for a non-FLRW background can be interpreted as the sum of a spatial curvature and an anisotropic fluid. This may lead to interesting effects of averaging on astrophysical scales. We also discuss the results of averaging an inhomogeneous Lemaitre-Tolman-Bondi solution as well as calculations of linear perturbations (that is, the backreaction) in an FLRW background, which support the main conclusions of the analysis
Elastic interaction between surface and spherical pore
International Nuclear Information System (INIS)
Ganeev, G.Z.; Kadyrzhanov, K.K.; Kislitsyn, S.B.; Turkebaev, T.Eh.
2000-01-01
The energy of elastic interaction of a gas-filled spherical cavity with a boundary of an elastic isotropic half-space is determined. The elastic field of a system of a spherical cavity - boundary is represented as an expansion in series of potential functions. The factors of expansions are determined by boundary conditions on a free surface of an elastic half-space and on a spherical surface of a cavity with pressure of gas P. Function of a Tresca-Miesesa on a surface of elastic surface is defined additionally with purpose creep condition determination caused by gas pressure in the cavity. (author)
DEFF Research Database (Denmark)
Hashemi Toghroljerdi, Seyedmostafa; Østergaard, Jacob; Yang, Guangya
2014-01-01
In this paper a new method is proposed to determine the minimum energy storage required to be installed at different locations of a low voltage (LV) grid in order to prevent the overvoltage due to high residential photovoltaic (PV) penetration. The method is based on the voltage sensitivity...... with different occurrence probabilities without involving the time-series studies problems. The proposed method is capable of modeling output power of PV panels with different orientations as well as different electric vehicle (EV) charging patterns....
Monodromy in the quantum spherical pendulum
International Nuclear Information System (INIS)
Guillemin, V.; Uribe, A.
1989-01-01
In this article we show that monodromy in the quantum spherical pendulum can be interpreted as a Maslov effect: i.e. as multi-valuedness of a certain generating function of the quantum energy levels. (orig.)
Transformation of Real Spherical Harmonics under Rotations
Romanowski, Z.; Krukowski, St.; Jalbout, A. F.
2008-08-01
The algorithm rotating the real spherical harmonics is presented. The convenient and ready to use formulae for l = 0, 1, 2, 3 are listed. The rotation in R3 space is determined by the rotation axis and the rotation angle; the Euler angles are not used. The proposed algorithm consists of three steps. (i) Express the real spherical harmonics as the linear combination of canonical polynomials. (ii) Rotate the canonical polynomials. (iii) Express the rotated canonical polynomials as the linear combination of real spherical harmonics. Since the three step procedure can be treated as a superposition of rotations, the searched rotation matrix for real spherical harmonics is a product of three matrices. The explicit formulae of matrix elements are given for l = 0, 1, 2, 3, what corresponds to s, p, d, f atomic orbitals.
Optical properties of spherical gold mesoparticles
DEFF Research Database (Denmark)
Evlyukhin, A. B.; Kuznetsov, A. I.; Novikov, S. M.
2012-01-01
Optical properties of spherical gold particles with diameters of 150-650 nm (mesoparticles) are studied by reflectance spectroscopy. Particles are fabricated by laser-induced transfer of metallic droplets onto metal and dielectric substrates. Contributions of higher multipoles (beyond...
Spiral CT manifestations of spherical pneumonia
International Nuclear Information System (INIS)
Li Xiaohong; Yang Hongwei; Xu Chunmin; Qin Xiu
2008-01-01
Objective: To explore the Spiral CT manifestations and differential diagnosis of spherical pneumonia. Methods: 18 cases of spherical pneumonia and 20 cases of peripheral pulmonary carcinoma were selected, both of them were confirmed by clinic and/or pathology. The SCT findings of both groups were compared retrospectively. Results: Main spiral CT findings of spherical pneumonia were showed as followings: square or triangular lesions adjacent to pleura; with irregular shape, blurry, slightly lobulated margin, sometimes with halo sign. Small inflammatory patches and intensified vascular markings around the lesions were seen. Lesions became smaller or vanished after short-term anti-inflammatory treatment. Conclusion: Spherical pneumonia showed some characteristics on Spiral CT scan, which are helpful in diagnosis and differential diagnosis of this disease. (authors)
FY 2006 Miniature Spherical Retroreflectors Final Report
Energy Technology Data Exchange (ETDEWEB)
Anheier, Norman C.; Bernacki, Bruce E.; Krishnaswami, Kannan
2006-12-28
Research done by the Infrared Photonics team at Pacific Northwest National Laboratory (PNNL) is focused on developing miniature spherical retroreflectors using the unique optical and material properties of chalcogenide glass to reduce both performance limiting spherical aberrations. The optimized optical performance will provide efficient signal retroreflection that enables a broad range of remote detection scenarios for mid-wave infrared (MWIR) and long-wave infrared (LWIR) sensing applications. Miniature spherical retroreflectors can be developed to aid in the detection of signatures of nuclear proliferation or other chemical vapor or radiation signatures. Miniature spherical retroreflectors are not only well suited to traditional LIDAR methods for chemical plume detection and identification, but could enable remote detection of difficult semi-volatile chemical materials or low level radiation sources.
Feasibility study for the Spherical Torus Experiment
International Nuclear Information System (INIS)
Lazarus, E.A.; Attenberger, S.E.; Baylor, L.R.
1985-10-01
The design of the Spherical Torus Experiment (STX) is discussed. The physics of the plasma are given in a magnetohydrodynamic model. The structural aspects and instrumentation of the device are described. 19 refs., 103 figs
Directory of Open Access Journals (Sweden)
Fernanda V.A. da Costa
Full Text Available ABSTRACT: Using a retrospective study, 493 cats tested for FeLV and FIV were selected for analysis of the association between hematologic findings and positivity at immunoassay test. Individual and hematologic variables were assessed considering the influence of results using univariate and multivariate logistic regression analysis. Out 153 of the 493 cats were positive for FeLV (31%, 50 were positive for FIV (10.1% and 22 were positive for both FIV and FeLV (4.4%. Multivariate analysis detected significant associations between FeLV infection and age below 1 year (p=0.01, age from 1 to 10 years (p=0.03, and crossbreed (p=0.04. Male cats were more likely to be FIV-positive (p=0.002. Regarding hematological changes, FeLV-positive cats have higher odds to anemia, leukopenia and lymphopenia than FeLV-negative cats. FIV-positive cats are more likely to have anemia than negative. Identification of associated factors related to animal status and correlation of hematological disorders with infection by retroviruses in cats could be useful for detecting these retroviral diseases in cats.
Directory of Open Access Journals (Sweden)
Pei-Hui Wang
Full Text Available The Toll-like receptor (TLR-mediated NF-κB pathway is tightly controlled because overactivation may result in severe damage to the host, such as in the case of chronic inflammatory diseases and cancer. In mammals, sterile-alpha and armadillo motif-containing protein (SARM plays an important role in negatively regulating this pathway. While Caenorhabditis elegans SARM is crucial for an efficient immune response against bacterial and fungal infections, it is still unknown whether Drosophila SARM participates in immune responses. Here, Litopenaeus vannamei SARM (LvSARM was cloned and functionally characterized. LvSARM shared signature domains with and exhibited significant similarities to mammalian SARM. Real-time quantitative PCR analysis indicated that the expression of LvSARM was responsive to Vibrio alginolyticus and white spot syndrome virus (WSSV infections in the hemocyte, gill, hepatopancreas and intestine. In Drosophila S2 cells, LvSARM was widely distributed in the cytoplasm and could significantly inhibit the promoters of the NF-κB pathway-controlled antimicrobial peptide genes (AMPs. Silencing of LvSARM using dsRNA-mediated RNA interference increased the expression levels of Penaeidins and antilipopolysaccharide factors, which are L.vannamei AMPs, and increased the mortality rate after V. alginolyticus infection. Taken together, our results reveal that LvSARM may be a novel component of the shrimp Toll pathway that negatively regulates shrimp AMPs, particularly Penaeidins and antilipopolysaccharide factors.
Vismane, Inese
2010-01-01
Maģistra darba tēma ir „Interneta sociālie tīkli draugiem.lv, mammam/tetiem.lv un twitter.com kā reklāmas nesēji Latvijā (2009.gads)”. Darba mērķis ir izpētīt Latvijas interneta sociālo tīklu vidi kā potenciāli augošu un reklāmai piemērotu, kā arī izpētīt pamanāmākos reklāmas gadījumus šajos portālos. Teorijas daļā tiek apskatīta Web 2.0 ēra, interneta reklāmas un sociālo mediju mārketinga īpatnības, sociālo tīklu fenomens un teorijas, Latvijas reklāmas tirgus un auditorija, kā arī sociāl...
3D Printing Electrically Small Spherical Antennas
DEFF Research Database (Denmark)
Kim, Oleksiy S.
2013-01-01
3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations.......3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations....
Method of producing spherical lithium aluminate particles
International Nuclear Information System (INIS)
Yang, L.; Medico, R.R.; Baugh, W.A.
1983-01-01
Spherical particles of lithium aluminate are formed by initially producing aluminium hydroxide spheroids, and immersing the spheroids in a lithium ion-containing solution to infuse lithium ions into the spheroids. The lithium-infused spheroids are rinsed to remove excess lithium ion from the surface, and the rinsed spheroids are soaked for a period of time in a liquid medium, dried and sintered to form lithium aluminate spherical particles. (author)
START: the creation of a spherical tokamak
International Nuclear Information System (INIS)
Sykes, Alan
1992-01-01
The START (Small Tight Aspect Ratio Tokamak) plasma fusion experiment is now operational at AEA Fusion's Culham Laboratory. It is the world's first experiment to explore an extreme limit of the tokamak - the Spherical Tokamak - which theoretical studies predict may have substantial advantages in the search for economic fusion power. The Head of the START project, describes the concept, some of the initial experimental results and the possibility of developing a spherical tokamak power reactor. (author)
Spherical cows in dark matter indirect detection
Energy Technology Data Exchange (ETDEWEB)
Bernal, Nicolás [Centro de Investigaciones, Universidad Antonio Nariño, Cra 3 Este # 47A-15, Bogotá (Colombia); Necib, Lina; Slatyer, Tracy R., E-mail: nicolas.bernal@uan.edu.co, E-mail: lnecib@mit.edu, E-mail: tslatyer@mit.edu [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)
2016-12-01
Dark matter (DM) halos have long been known to be triaxial, but in studies of possible annihilation and decay signals they are often treated as approximately spherical. In this work, we examine the asymmetry of potential indirect detection signals of DM annihilation and decay, exploiting the large statistics of the hydrodynamic simulation Illustris. We carefully investigate the effects of the baryons on the sphericity of annihilation and decay signals for both the case where the observer is at 8.5 kpc from the center of the halo (exemplified in the case of Milky Way-like halos), and for an observer situated well outside the halo. In the case of Galactic signals, we find that both annihilation and decay signals are expected to be quite symmetric, with axis ratios very different from 1 occurring rarely. In the case of extragalactic signals, while decay signals are still preferentially spherical, the axis ratio for annihilation signals has a much flatter distribution, with elongated profiles appearing frequently. Many of these elongated profiles are due to large subhalos and/or recent mergers. Comparing to gamma-ray emission from the Milky Way and X-ray maps of clusters, we find that the gamma-ray background appears less spherical/more elongated than the expected DM signal from the large majority of halos, and the Galactic gamma ray excess appears very spherical, while the X-ray data would be difficult to distinguish from a DM signal by elongation/sphericity measurements alone.
International Nuclear Information System (INIS)
Aoi, Y; Tominaga, T
2013-01-01
Titanium dioxide (TiO 2 ) inverse opals in spherical shape were prepared by liquid phase deposition (LPD) using spherical colloidal crystals as templates. Spherical colloidal crystals were produced by ink-jet drying technique. Aqueous emulsion droplets that contain polystyrene latex particles were ejected into air and dried. Closely packed colloidal crystals with spherical shape were obtained. The obtained spherical colloidal crystals were used as templates for the LPD. The templates were dispersed in the deposition solution of the LPD, i.e. a mixed solution of ammonium hexafluorotitanate and boric acid and reacted for 4 h at 30 °C. After the LPD process, the interstitial spaces of the spherical colloidal crystals were completely filled with titanium oxide. Subsequent heat treatment resulted in removal of templates and spherical titanium dioxide inverse opals. The spherical shape of the template was retained. SEM observations indicated that the periodic ordered voids were surrounded by titanium dioxide. The optical reflectance spectra indicated that the optical properties of the spherical titanium dioxide inverse opals were due to Bragg diffractions from the ordered structure. Filling in the voids of the inverse opals with different solvents caused remarkable changes in the reflectance peak.
Garcia, M J; Smedira, N G; Greenberg, N L; Main, M; Firstenberg, M S; Odabashian, J; Thomas, J D
2000-01-01
To determine the effect of preload in color M-mode Doppler flow propagation velocity (v(p)). The interpretation of Doppler filling patterns is limited by confounding effects of left ventricular (LV) relaxation and preload. Color M-mode v(p) has been proposed as a new index of LV relaxation. We studied four dogs before and during inferior caval (IVC) occlusion at five different inotropic stages and 14 patients before and during partial cardiopulmonary bypass. Left ventricular (LV) end-diastolic volumes (LV-EDV), the time constant of isovolumic relaxation (tau), left atrial (LA) pre-A and LV end-diastolic pressures (LV-EDP) were measured. Peak velocity during early filling (E) and v(p) were extracted by digital analysis of color M-mode Doppler images. In both animals and humans, LV-EDV and LV-EDP decreased significantly from baseline to IVC occlusion (both p < 0.001). Peak early filling (E) velocity decreased in animals from 56 +/- 21 to 42 +/- 17 cm/s (p < 0.001) without change in v(p) (from 35 +/- 15 to 35 +/- 16, p = 0.99). Results were similar in humans (from 69 +/- 15 to 53 +/- 22 cm/s, p < 0.001, and 37 +/- 12 to 34 +/- 16, p = 0.30). In both species, there was a strong correlation between LV relaxation (tau) and v(p) (r = 0.78, p < 0.001, r = 0.86, p < 0.001). Our results indicate that color M-mode Doppler v(p) is not affected by preload alterations and confirms that LV relaxation is its main physiologic determinant in both animals during varying lusitropic conditions and in humans with heart disease.
Laboratorios virtuales (LV como apoyo a las prácticas a distancia y presenciales en ingeniería
Directory of Open Access Journals (Sweden)
Francis Castellanos
2010-01-01
Full Text Available El presente artículo tiene como propósito mostrar los procesos inherentes a cada una de las etapas de diseño y desarrollo en un Laboratorio Virtual, LV, y más específicamente para el laboratorio redes convergentes de la Institución. Durante la investigación, se desarrolló una metodología basada en los lineamientos del PMI (Project Management Institute que servirá como base para la creación de futuros laboratorios virtuales en cualquier área del conocimiento. Para el acceso de los laboratorios se desarrolló la herramienta de Software Vlab, como una plataforma integradora de laboratorios virtuales para la Institución. Los LV son simulaciones consideradas como una alternativa pedagógica para el desarrollo de prácticas a distancia o como apoyo a las prácticas en la presencialidad, que ofrecen a los estudiantes la oportunidad de adquirir destrezas y habilidades en el manejo de materiales y equipos relacionados con las áreas de su campo de formación, sin restricción de tiempo o espacio.
Project of Ariane 5 LV family advancement by use of reusable fly-back boosters (named “Bargouzine”)
Sumin, Yu.; Bonnal, Ch.; Kostromin, S.; Panichkin, N.
2007-12-01
The paper concerns possible concept variants of a partially reusable Heavy-Lift Launch Vehicle derived from the advanced basic launcher (Ariane-2010) by means of substitution of the EAP Solid Rocket Boosters for a Reusable Starting Stage consisting two Liquid-propellant Reusable Fly-Back Boosters called "Bargouzin". This paper describes the status of the presently studied RFBB concepts during its three phases. The first project phase was dedicated to feasibility expertise of liquid-rocket reusable fly-back boosters ("Baikal" type) utilization for heavy-lift space launch vehicle. The design features and main conclusions are presented. The second phase has been performed with the purpose of selection of preferable concept among the alternative ones for the future Ariane LV modernization by using RFBB instead of EAP Boosters. The main requirements, logic of work, possible configuration and conclusion are presented. Initial aerodynamic, ballistic, thermoloading, dynamic loading, trade-off and comparison analysis have been performed on these concepts. The third phase consists in performing a more detailed expertise of the chosen LV concept. This part summarizes some of the more detailed results related to flight performance, system mass, thermoprotection system, aspects of technologies, ground complex modification, comparison analyses and conclusion.
Piacentino, Michael L; Chung, Oliver; Ramachandran, Janani; Zuch, Daniel T; Yu, Jia; Conaway, Evan A; Reyna, Arlene E; Bradham, Cynthia A
2016-04-01
Skeletal patterning in the sea urchin embryo requires coordinated signaling between the pattern-dictating ectoderm and the skeletogenic primary mesenchyme cells (PMCs); recent studies have begun to uncover the molecular basis for this process. Using an unbiased RNA-Seq-based screen, we have previously identified the TGF-ß superfamily ligand, LvBMP5-8, as a skeletal patterning gene in Lytechinus variegatus embryos. This result is surprising, since both BMP5-8 and BMP2/4 ligands have been implicated in sea urchin dorsal-ventral (DV) and left-right (LR) axis specification. Here, we demonstrate that zygotic LvBMP5-8 is required for normal skeletal patterning on the left side, as well as for normal PMC positioning during gastrulation. Zygotic LvBMP5-8 is required for expression of the left-side marker soxE, suggesting that LvBMP5-8 is required for left-side specification. Interestingly, we also find that LvBMP5-8 knockdown suppresses serotonergic neurogenesis on the left side. While LvBMP5-8 overexpression is sufficient to dorsalize embryos, we find that zygotic LvBMP5-8 is not required for normal DV specification or development. In addition, ectopic LvBMP5-8 does not dorsalize LvBMP2/4 morphant embryos, indicating that, in the absence of BMP2/4, BMP5-8 is insufficient to specify dorsal. Taken together, our data demonstrate that zygotic LvBMP5-8 signaling is essential for left-side specification, and for normal left-side skeletal and neural patterning, but not for DV specification. Thus, while both BMP2/4 and BMP5-8 regulate LR axis specification, BMP2/4 but not zygotic BMP5-8 regulates DV axis specification in sea urchin embryos. Copyright © 2016 Elsevier Inc. All rights reserved.
Sukhumavasi, Woraporn; Bellosa, Mary L; Lucio-Forster, Araceli; Liotta, Janice L; Lee, Alice C Y; Pornmingmas, Pitcha; Chungpivat, Sudchit; Mohammed, Hussni O; Lorentzen, Leif; Dubey, J P; Bowman, Dwight D
2012-08-13
The seroprevalence of Toxoplasma gondii, Dirofilaria immitis (heartworm), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections was examined using serum or plasma samples from 746 pet cats collected between May and July 2009 from clinics and hospitals located in and around Bangkok, Thailand. The samples were tested for heartworm, FIV, and FeLV using a commercial ELISA. Of the 746 samples, 4.6% (34/746) were positive for heartworm antigen, 24.5% (183/746) had circulating FeLV antigen, and 20.1% (150/746) had antibodies against FIV. In addition, the first 348 submitted samples were tested for T. gondii antibodies using a modified agglutination test (MAT, cut off 1:25); 10.1% (35/348) were seropositive. Of the 348 cats sampled for all four pathogens, 11, 10, and 1 were positive for T. gondii antibodies and FIV antibodies, FeLV antigen, or D. immitis antigen, respectively. Of the 35 T. gondii-seropositive cats, 42.9% (15/35) were co-infected with at least one of the other three pathogens. The presence of antibodies to FIV was significantly associated with both age and gender, while FeLV antigen presence was only associated with age. In the case of FIV, males were twice as likely to be infected as females, and cats over 10 years of age were 13.5 times more likely to be infected than cats less than 1 year of age. FeLV antigen was more common in younger cats, with cats over 10 years of age being 10 times less likely to be FeLV positive than cats under 1 year of age. This is the first survey for these four pathogens affecting feline health in Thailand. Copyright © 2012 Elsevier B.V. All rights reserved.
ELSA- The European Levitated Spherical Actruator
Ruiz, M.; Serin, J.; Telteu-Nedelcu, D.; De La Vallee Poussin, H.; Onillon, E.; Rossini, L.
2014-08-01
The reaction sphere is a magnetic bearing spherical actuator consisting of a permanent magnet spherical rotor that can be accelerated in any direction. It consists of an 8-pole permanent magnet spherical rotor that is magnetically levitated and can be accelerated about any axis by a 20-pole stator with electromagnets. The spherical actuator is proposed as a potential alternative to traditional momentum exchange devices such as reaction wheels (RWs) or control moment gyroscopes (CMGs). This new actuator provides several benefits such as reduced mass and power supply allocated to the attitude and navigation unit, performance gain, and improved reliability due to the absence of mechanical bearings. The paper presents the work done on the levitated spherical actuator and more precisely the electrical drive including its control unit and power parts. An elegant breadboard is currently being manufactured within the frame of an FP7 project. This project also comprises a feasibility study to show the feasibility of integrating such a system on a flight platform and to identify all the challenges to be solved in terms of technology or components to be developed.
Statistical Mechanics of Thin Spherical Shells
Directory of Open Access Journals (Sweden)
Andrej Košmrlj
2017-01-01
Full Text Available We explore how thermal fluctuations affect the mechanics of thin amorphous spherical shells. In flat membranes with a shear modulus, thermal fluctuations increase the bending rigidity and reduce the in-plane elastic moduli in a scale-dependent fashion. This is still true for spherical shells. However, the additional coupling between the shell curvature, the local in-plane stretching modes, and the local out-of-plane undulations leads to novel phenomena. In spherical shells, thermal fluctuations produce a radius-dependent negative effective surface tension, equivalent to applying an inward external pressure. By adapting renormalization group calculations to allow for a spherical background curvature, we show that while small spherical shells are stable, sufficiently large shells are crushed by this thermally generated “pressure.” Such shells can be stabilized by an outward osmotic pressure, but the effective shell size grows nonlinearly with increasing outward pressure, with the same universal power-law exponent that characterizes the response of fluctuating flat membranes to a uniform tension.
Scaling of a fast spherical discharge
Energy Technology Data Exchange (ETDEWEB)
Antsiferov, P. S., E-mail: Ants@isan.troitsk.ru; Dorokhin, L. A. [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation)
2017-02-15
The influence of the discharge cavity dimensions on the properties of the spherical plasma formed in a fast discharge was studied experimentally. The passage of a current pulse with an amplitude of 30–40 kA and a rise rate of ~10{sup 12} A/s (a fast discharge) through a spherical ceramic (Al{sub 2}O{sub 3}) cavity with an inner diameter of 11 mm filled with argon at a pressure of 80 Pa results in the formation of a 1- to 2-mm-diameter spherical plasma with an electron temperature of several tens of electronvolts and a density of 10{sup 18}–10{sup 19} cm{sup –3}. It is shown that an increase in the inner diameter of the discharge cavity from 11 to 21 mm leads to the fourfold increase in the formation time of the spherical plasma and a decrease in the average ion charge. A decrease in the cavity diameter to 7 mm makes the spherical plasma unstable.
Spherical aberrations of human astigmatic corneas.
Zhao, Huawei; Dai, Guang-Ming; Chen, Li; Weeber, Henk A; Piers, Patricia A
2011-11-01
To evaluate whether the average spherical aberration of human astigmatic corneas is statistically equivalent to human nonastigmatic corneas. Spherical aberrations of 445 astigmatic corneas prior to laser vision correction were retrospectively investigated to determine Zernike coefficients for central corneal areas 6 mm in diameter using CTView (Sarver and Associates). Data were divided into groups according to cylinder power (0.01 to 0.25 diopters [D], 0.26 to 0.75 D, 0.76 to 1.06 D, 1.07 to 1.53 D, 1.54 to 2.00 D, and >2.00 D) and according to age by decade. Spherical aberrations were correlated with age and astigmatic power among groups and the entire population. Statistical analyses were conducted, and P.05 for all tested groups). Mean spherical aberration of astigmatic corneas was not correlated significantly with cylinder power or age (P>.05). Spherical aberrations are similar to those of nonastigmatic corneas, permitting the use of these additional data in the design of aspheric toric intra-ocular lenses. Copyright 2011, SLACK Incorporated.
Recent Progress on Spherical Torus Research
Energy Technology Data Exchange (ETDEWEB)
Ono, Masayuki [PPPL; Kaita, Robert [PPPL
2014-01-01
The spherical torus or spherical tokamak (ST) is a member of the tokamak family with its aspect ratio (A = R0/a) reduced to A ~ 1.5, well below the normal tokamak operating range of A ≥ 2.5. As the aspect ratio is reduced, the ideal tokamak beta β (radio of plasma to magnetic pressure) stability limit increases rapidly, approximately as β ~ 1/A. The plasma current it can sustain for a given edge safety factor q-95 also increases rapidly. Because of the above, as well as the natural elongation κ, which makes its plasma shape appear spherical, the ST configuration can yield exceptionally high tokamak performance in a compact geometry. Due to its compactness and high performance, the ST configuration has various near term applications, including a compact fusion neutron source with low tritium consumption, in addition to its longer term goal of attractive fusion energy power source. Since the start of the two megaampere class ST facilities in 2000, National Spherical Torus Experiment (NSTX) in the US and Mega Ampere Spherical Tokamak (MAST) in UK, active ST research has been conducted worldwide. More than sixteen ST research facilities operating during this period have achieved remarkable advances in all of fusion science areas, involving fundamental fusion energy science as well as innovation. These results suggest exciting future prospects for ST research both near term and longer term. The present paper reviews the scientific progress made by the worldwide ST research community during this new mega-ampere-ST era.
Friction factor for water flow through packed beds of spherical and non-spherical particles
Directory of Open Access Journals (Sweden)
Kaluđerović-Radoičić Tatjana
2017-01-01
Full Text Available The aim of this work was the experimental evaluation of different friction factor correlations for water flow through packed beds of spherical and non-spherical particles at ambient temperature. The experiments were performed by measuring the pressure drop across the bed. Packed beds made of monosized glass spherical particles of seven different diameters were used, as well as beds made of 16 fractions of quartz filtration sand obtained by sieving (polydisperse non-spherical particles. The range of bed voidages was 0.359–0.486, while the range of bed particle Reynolds numbers was from 0.3 to 286 for spherical particles and from 0.1 to 50 for non-spherical particles. The obtained results were compared using a number of available literature correlations. In order to improve the correlation results for spherical particles, a new simple equation was proposed in the form of Ergun’s equation, with modified coefficients. The new correlation had a mean absolute deviation between experimental and calculated values of pressure drop of 9.04%. For non-spherical quartz filtration sand particles the best fit was obtained using Ergun’s equation, with a mean absolute deviation of 10.36%. Surface-volume diameter (dSV necessary for correlating the data for filtration sand particles was calculated based on correlations for dV = f(dm and Ψ = f(dm. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. ON172022
The spherical harmonics method, II (application to problems with plane and spherical symmetry)
Energy Technology Data Exchange (ETDEWEB)
Mark, C
1958-12-15
The application of the spherical harmonic method to problems with plane or spherical symmetry is discussed in detail. The numerical results of some applications already made are included to indicate the degree of convergence obtained. Formulae for dealing with distributions of isotropic sources are developed. Tables useful in applying the method are given in Section 11. (author)
A spherical Taylor-Couette dynamo
Marcotte, Florence; Gissinger, Christophe
2016-04-01
We present a new scenario for magnetic field amplification in the planetary interiors where an electrically conducting fluid is confined in a differentially rotating, spherical shell (spherical Couette flow) with thin aspect-ratio. When the angular momentum sufficiently decreases outwards, a primary hydrodynamic instability is widely known to develop in the equatorial region, characterized by pairs of counter-rotating, axisymmetric toroidal vortices (Taylor vortices) similar to those observed in cylindrical Couette flow. We characterize the subcritical dynamo bifurcation due to this spherical Taylor-Couette flow and study its evolution as the flow successively breaks into wavy and turbulent Taylor vortices for increasing Reynolds number. We show that the critical magnetic Reynolds number seems to reach a constant value as the Reynolds number is gradually increased. The role of global rotation on the dynamo threshold and the implications for planetary interiors are finally discussed.
Spherical tokamak power plant design issues
International Nuclear Information System (INIS)
Hender, T.C.; Bond, A.; Edwards, J.; Karditsas, P.J.; McClements, K.G.; Mustoe, J.; Sherwood, D.V.; Voss, G.M.; Wilson, H.R.
2000-01-01
The very high β potential of the spherical tokamak has been demonstrated in the START experiment. Systems code studies show the cost of electricity from spherical tokamak power plants, operating at high β in second ballooning mode stable regime, is comparable with fossil fuels and fission. Outline engineering designs are presented based on two concepts for the central rod of the toroidal field (TF) circuit - a room temperature water cooled copper rod or a helium cooled cryogenic aluminium rod. For the copper rod case the TF return limbs are supported by the vacuum vessel, while for the aluminium rod the TF coils form an independent structure. In both cases thermohydraulic and stress calculations indicate the viability of the design. Two-dimensional neutronics calculations show the feasibility of tritium self-sufficiency without an inboard blanket. The spherical tokamak has unique maintenance possibilities based on lowering major component structures into a hot cell beneath the device and these are discussed
Dynamics of a spherical minority game
International Nuclear Information System (INIS)
Galla, T; Coolen, A C C; Sherrington, D
2003-01-01
We present an exact dynamical solution of a spherical version of the batch minority game (MG) with random external information. The control parameters in this model are the ratio of the number of possible values for the public information over the number of agents, and the radius of the spherical constraint on the microscopic degrees of freedom. We find a phase diagram with three phases: two without anomalous response (an oscillating versus a frozen state) and a further frozen phase with divergent integrated response. In contrast to standard MG versions, we can also calculate the volatility exactly. Our study reveals similarities between the spherical and the conventional MG, but also intriguing differences. Numerical simulations confirm our analytical results
Electrostatic axisymmetric mirror with removable spherical aberration
International Nuclear Information System (INIS)
Birmuzaev, S.B.; Serikbaeva, G.S.; Hizirova, M.A.
1999-01-01
The electrostatic axisymmetric mirror, assembled from three coaxial cylinders with an equal diameter d and under the potential v1, v2 and v3, was computed. The proportions of geometrical and electric parameters of the mirror, with which the spherical 3-order aberration may be eliminated, were determined. The computation outcomes of the case, when the focal power of the mirror is enough large and the object plane in the focus is out of its field, are presented (Fig. 1 - potentials proportion that makes elimination of the spherical aberration possible; Fig. 2 - the focus coordinates when the spherical aberration is eliminated). The geometrical values are presented by d, and the electric ones are presented by v1. The figures on the curves present a length of the second (middle) electrode. The zero point is located in the middle of the gap between the first and second electrodes The investigated mirror may be used as a lens for the transmission electron microscope
Flow and scour around spherical bodies
DEFF Research Database (Denmark)
Truelsen, Christoffer
2003-01-01
Spherical bodies placed in the marine environment may bury themselves due to the action of the waves and the current on the sediment in their immediate neighborhood. The present study addresses this topic by a numerical and an experimental investigation of the flow and scour around a spherical body...... results except in the critical flow regime. For flow around a near-wall sphere, a weak horseshoe vortex emerges as the gap ratio becomes less than or equal to 0.3. In Chapter 3, a RANS flow solver has been used to compute the bed shear stress for a near-wall sphere. The model results compare well...... 4, an experimental study on the scour around spherical bodies and self-burial in sand for steady current and waves has been carried out. The effect of the contraction of streamlines is found to be the key element in the scour process both for steady current and waves. Furthermore, it is demonstrated...
Elastic properties of spherically anisotropic piezoelectric composites
International Nuclear Information System (INIS)
En-Bo, Wei; Guo-Qing, Gu; Ying-Ming, Poon
2010-01-01
Effective elastic properties of spherically anisotropic piezoelectric composites, whose spherically anisotropic piezoelectric inclusions are embedded in an infinite non-piezoelectric matrix, are theoretically investigated. Analytical solutions for the elastic displacements and the electric potentials under a uniform external strain are derived exactly. Taking into account of the coupling effects of elasticity, permittivity and piezoelectricity, the formula is derived for estimating the effective elastic properties based on the average field theory in the dilute limit. An elastic response mechanism is revealed, in which the effective elastic properties increase as inclusion piezoelectric properties increase and inclusion dielectric properties decrease. Moreover, a piezoelectric response mechanism, of which the effective piezoelectric response vanishes due to the symmetry of spherically anisotropic composite, is also disclosed. (condensed matter: structure, thermal and mechanical properties)
Chen, Chun; Li, Dianfu; Miao, Changqing; Feng, Jianlin; Zhou, Yanli; Cao, Kejiang; Lloyd, Michael S; Chen, Ji
2012-07-01
The purpose of this study was to evaluate left ventricular (LV) mechanical dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome pre- and post-radiofrequency catheter ablation (RFA) using phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Forty-five WPW patients were enrolled and had gated SPECT MPI pre- and 2-3 days post-RFA. Electrophysiological study (EPS) was used to locate accessory pathways (APs) and categorize the patients according to the AP locations (septal, left and right free wall). Electrocardiography (ECG) was performed pre- and post-RFA to confirm successful elimination of the APs. Phase analysis of gated SPECT MPI was used to assess LV dyssynchrony pre- and post-RFA. Among the 45 patients, 3 had gating errors, and thus 42 had SPECT phase analysis. Twenty-two patients (52.4%) had baseline LV dyssynchrony. Baseline LV dyssynchrony was more prominent in the patients with septal APs than in the patients with left or right APs (p syndrome. Septal APs result in the greatest degree of LV mechanical dyssynchrony and afford the most benefit after RFA. This study supports further investigation in the relationship between electrical and mechanical activation using EPS and phase analysis of gated SPECT MPI.
Directory of Open Access Journals (Sweden)
Mark James Robinson
2011-01-01
Full Text Available Xenotropic murine leukaemia virus-related virus (XMRV is a recently described retrovirus which has been claimed to infect humans and cause associated pathology. Initially identified in the US in patients with prostate cancer and subsequently in patients with chronic fatigue syndrome, doubt now exists that XMRV is a human pathogen. We studied the prevalence of genetic sequences of XMRV and related MuLV sequences in human prostate cancer, from B cell lymphoma patients and from UK blood donors. Nucleic acid was extracted from fresh prostate tissue biopsies, formalin-fixed paraffin-embedded (FFPE prostate tissue and FFPE B-cell lymphoma. The presence of XMRV-specific LTR or MuLV generic gag-like sequences was investigated by nested PCR. To control for mouse DNA contamination, a PCR that detected intracisternal A-type particle (IAP sequences was included. In addition, DNA and RNA were extracted from whole blood taken from UK blood donors and screened for XMRV sequences by real-time PCR. XMRV or MuLV-like sequences were not amplified from tissue samples. Occasionally MuLV gag and XMRV-LTR sequences were amplified from Indian prostate cancer samples, but were always detected in conjunction with contaminating murine genomic DNA. We found no evidence of XMRV or MuLV infection in the UK blood donors.
Energy Technology Data Exchange (ETDEWEB)
Ban, Kazunobu; Nakajima, Toru; Aoki, Naoto; Abe, Sumihisa; Handa, Shunnosuke; Suzuki, Yutaka [Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine
1998-11-01
The quantitative gated SPECT (QGS) software that has automatic edge detection algorithm of the left ventricle, is able to calculate LV volumes and visualize LV wall motion with perfusion throughout the cardiac cycle. We evaluated the reliability of global and regional LV function derived from QGS using {sup 99m}Tc-tetrofosmin by comparing with left ventricular cineangiography (LVG) and echocardiography (ECHO). In 22 cardiac patients, end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) were calculated. Using cinematic display, regional LV wall motion were scored on a 3-point scale (1=normal, 2=hypokinesis, 3=akinesis; WMS). EDV, ESV and LVEF correlated well with those by LVG (p<0.001 for each). Correlation between WMS derived from QGS and ECHO was high (r=0.85, p<0.001). There was an inverse correlation between WMS and LVEF (r=0.77, p<0.001). In conclusion, QGS is useful to evaluate global LV function. Regional wall motion evaluated by QGS is good enough for clinical application. (author)
Studies of spherical inertial-electrostatic confinement
International Nuclear Information System (INIS)
Miley, G.H.
1992-01-01
Theoretical and experimental results from studies of Spherical Inertial-Electrostatic Confinement (SIEC) are presented. This principle of IEC involves the confinement by multiple potential wells created by ion injection into a spherical device containing biased grids. A semitransparent cathode accelerates ions, generating a spherical ion-beam flow which converges at the center of the spherical volume, creating a space charge (potential well) region. An electron flow is created by the core (virtual anode) region, forming in turn a virtual cathode. Ions trapped inside this well oscillate back and forth until they fuse or degrade in energy. Such multiple wells with virtual anodes and cathodes, have been called ''Poissors'' following the original work by Farnsworth and by Hirsch. Fusion within the core occurs by reactions between non-Maxwellian beam-beam type ions. This has the potential for achieving a high power density and also for burning both D-T and advanced fuels. If successful, such a device would be attractive for a variety of high power density applications, e.g., space power or as a neutron source based on D-D or D-T operation. Simulations of recent SIEC experiments have been carried out using the XL-code, to solve Poisson's equation, self-consistently with the collisionless Vlasov equation in spherical geometry for several current species and grid parameters. The potential profile predictions are reasonably consistent with experimental results. Potential well measurements used a collimated proton detector. Results indicate that an ∼ 15-kV virtual anode, at least one centimeter in radius, was formed in a spherical device with a cathode potential of 30 kV using an ion current of ∼ 30 mA. Analysis indicates D + densities on the order of 10 9 cm -3 , and D 2 + densities on the order of 10 10 cm -3 . Steady-state D-D neutron emission of about 10 6 n/sec is observed
Analysis of a spherical permanent magnet actuator
International Nuclear Information System (INIS)
Wang, J.; Jewell, G.W.; Howe, D.
1997-01-01
This paper describes a new form of actuator with a spherical permanent magnet rotor and a simple winding arrangement, which is capable of a high specific torque by utilizing a rare-earth permanent magnet. The magnetic-field distribution is established using an analytical technique formulated in spherical coordinates, and the results are validated by finite element analysis. The analytical field solution allows the prediction of the actuator torque and back emf in closed forms. In turn, these facilitate the characterization of the actuator and provide a firm basis for design optimization, system dynamic modeling, and closed-loop control law development. copyright 1997 American Institute of Physics
Development of a spherical neutron rem monitor
International Nuclear Information System (INIS)
Panchal, C.G.; Madhavi, V.; Bansode, P.Y.; Jakati, R.K.; Ghodgaonkar, M.D.; Desai, S.S.; Shaikh, A.M.; Sathian, V.
2007-01-01
A new neutron rem monitor based on spherical LINUS with the state of art electronic circuits has been designed in Electronics Division. This prototype instrument encompasses a spherical double polythene moderator to improve an isotropic response and a lead layer to extend its energy response compared to the conventional neutron rem monitors. A systematic testing and calibration of the energy and directional response of the prototype monitor have been carried out. Although the monitor is expected to perform satisfactorily upto an energy ∼ 55 MeV, at present its response has been tested upto 5 MeV. (author)
MoMuLV-ts-1: A Unique Mouse Model of Retrovirus-Induced Lymphoma Transmitted by Breast Milk
Directory of Open Access Journals (Sweden)
J. Chakraborty
2011-01-01
Full Text Available Our laboratory has developed a murine model of lymphoma via breast milk transmission of MoMuLV-ts-1 (Moloney murine leukemia virus-temperature sensitive mutant-1. Uninfected offspring suckled from infected surrogate mothers become infected and develop lymphoma. Multiple gene integration sites of ts-1 into the infected mouse genome including tacc3, aurka, ndel1, tpx2, p53, and rhamm were identified, and mRNA expressions were quantitated. These genes produce centrosomal proteins, which may be involved in abnormal chromosomal segregation leading to aneuploidy or multiploidy, thus causing lymphoma. Since there is no report to date on this retroviral model leading to centrosomal abnormality, and causing lymphoma development, this is a valuable and unique model to study the centrosomal involvement in lymphomagenesis.
O'Donnell, David; Sperzel, Johannes; Thibault, Bernard; Rinaldi, Christopher A; Pappone, Carlo; Gutleben, Klaus-Jürgen; Leclercq, Christopher; Razavi, Hedi; Ryu, Kyungmoo; Mcspadden, Luke C; Fischer, Avi; Tomassoni, Gery
2017-04-01
The aim of this study was to evaluate any benefits to the number of viable pacing vectors and maximal spatial coverage with quadripolar left ventricular (LV) leads when compared with tripolar and bipolar equivalents in patients receiving cardiac resynchronization therapy (CRT). A meta-analysis of five previously published clinical trials involving the Quartet™ LV lead (St Jude Medical, St Paul, MN, USA) was performed to evaluate the number of viable pacing vectors defined as capture thresholds ≤2.5 V and no phrenic nerve stimulation and maximal spatial coverage of viable vectors in CRT patients at pre-discharge (n = 370) and first follow-up (n = 355). Bipolar and tripolar lead configurations were modelled by systematic elimination of two and one electrode(s), respectively, from the Quartet lead. The Quartet lead with its four pacing electrodes exhibited the greatest number of pacing vectors per patient when compared with the best bipolar and the best tripolar modelled equivalents. Similarly, the Quartet lead provided the highest spatial coverage in terms of the distance between two furthest viable pacing cathodes when compared with the best bipolar and the best tripolar configurations (P tripolar configurations, elimination of the second proximal electrode (M3) resulted in the highest number of viable pacing options per patient. There were no significant differences observed between pre-discharge and first follow-up analyses. The Quartet lead with its four electrodes and the capability to pace from four anatomical locations provided the highest number of viable pacing vectors at pre-discharge and first follow-up visits, providing more flexibility in device programming and enabling continuation of CRT in more patients when compared with bipolar and tripolar equivalents. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.
Pat, Betty; Chen, Yuanwen; Killingsworth, Cheryl; Gladden, James D; Shi, Ke; Zheng, Junying; Powell, Pamela C; Walcott, Greg; Ahmed, Mustafa I; Gupta, Himanshu; Desai, Ravi; Wei, Chih-Chang; Hase, Naoki; Kobayashi, Tsunefumi; Sabri, Abdelkarim; Granzier, Henk; Denney, Thomas; Tillson, Michael; Dillon, A Ray; Husain, Ahsan; Dell'italia, Louis J
2010-10-12
The left ventricular (LV) dilatation of isolated mitral regurgitation (MR) is associated with an increase in chymase and a decrease in interstitial collagen and extracellular matrix. In addition to profibrotic effects, chymase has significant antifibrotic actions because it activates matrix metalloproteinases and kallikrein and degrades fibronectin. Thus, we hypothesize that chymase inhibitor (CI) will attenuate extracellular matrix loss and LV remodeling in MR. We studied dogs with 4 months of untreated MR (MR; n=9) or MR treated with CI (MR+CI; n=8). Cine MRI demonstrated a >40% increase in LV end-diastolic volume in both groups, consistent with a failure of CI to improve a 25% decrease in interstitial collagen in MR. However, LV cardiomyocyte fractional shortening was decreased in MR versus normal dogs (3.71±0.24% versus 4.81±0.31%; P<0.05) and normalized in MR+CI dogs (4.85±0.44%). MRI with tissue tagging demonstrated an increase in LV torsion angle in MR+CI versus MR dogs. CI normalized the significant decrease in fibronectin and FAK phosphorylation and prevented cardiomyocyte myofibrillar degeneration in MR dogs. In addition, total titin and its stiffer isoform were increased in the LV epicardium and paralleled the changes in fibronectin and FAK phosphorylation in MR+CI dogs. These results suggest that chymase disrupts cell surface-fibronectin connections and FAK phosphorylation that can adversely affect cardiomyocyte myofibrillar structure and function. The greater effect of CI on epicardial versus endocardial titin and noncollagen cell surface proteins may be responsible for the increase in torsion angle in chronic MR.
Tharp, Darla L.; Ivey, Jan R.; Ganjam, Venkataseshu K.; Bowles, Douglas K.
2011-01-01
Coronary vascular dysfunction has been observed in several models of heart failure (HF). Recent evidence indicates that exercise training is beneficial for patients with HF, but the precise intensity and underlying mechanisms are unknown. Left ventricular (LV) hypertrophy can play a significant role in the development of HF; therefore, the purpose of this study was to assess the effects of low-intensity interval exercise training on coronary vascular function in sedentary (HF) and exercise trained (HF-TR) aortic-banded miniature swine displaying LV hypertrophy. Six months postsurgery, in vivo coronary vascular responses to endothelin-1 (ET-1) and adenosine were measured in the left anterior descending coronary artery. Baseline and maximal coronary vascular conductance were similar between all groups. ET-1-induced reductions in coronary vascular conductance (P < 0.05) were greater in HF vs. sedentary control and HF-TR groups. Pretreatment with the ET type A (ETA) receptor blocker BQ-123 prevented ET-1 hypersensitivity in HF animals. Whole cell voltage clamp was used to characterize composite K+ currents (IK+) in coronary smooth muscle cells. Raising internal Ca2+ from 200 to 500 nM increased Ca2+-sensitive K+ current in HF-TR and control, but not HF animals. In conclusion, an ETA-receptor-mediated hypersensitivity to ET-1, elevated resting LV wall tension, and decreased coronary smooth muscle cell Ca2+-sensitive IK+ was found in sedentary animals with LV hypertrophy. Low-intensity interval exercise training preserved normal coronary vascular function and smooth muscle cell Ca2+-sensitive IK+, illustrating a potential mechanism underlying coronary vascular dysfunction in a large-animal model of LV hypertrophy. Our results demonstrate the potential clinical impact of exercise on coronary vascular function in HF patients displaying pathological LV hypertrophy. PMID:21841018
Emter, Craig A; Tharp, Darla L; Ivey, Jan R; Ganjam, Venkataseshu K; Bowles, Douglas K
2011-10-01
Coronary vascular dysfunction has been observed in several models of heart failure (HF). Recent evidence indicates that exercise training is beneficial for patients with HF, but the precise intensity and underlying mechanisms are unknown. Left ventricular (LV) hypertrophy can play a significant role in the development of HF; therefore, the purpose of this study was to assess the effects of low-intensity interval exercise training on coronary vascular function in sedentary (HF) and exercise trained (HF-TR) aortic-banded miniature swine displaying LV hypertrophy. Six months postsurgery, in vivo coronary vascular responses to endothelin-1 (ET-1) and adenosine were measured in the left anterior descending coronary artery. Baseline and maximal coronary vascular conductance were similar between all groups. ET-1-induced reductions in coronary vascular conductance (P < 0.05) were greater in HF vs. sedentary control and HF-TR groups. Pretreatment with the ET type A (ET(A)) receptor blocker BQ-123 prevented ET-1 hypersensitivity in HF animals. Whole cell voltage clamp was used to characterize composite K(+) currents (I(K(+))) in coronary smooth muscle cells. Raising internal Ca(2+) from 200 to 500 nM increased Ca(2+)-sensitive K(+) current in HF-TR and control, but not HF animals. In conclusion, an ET(A)-receptor-mediated hypersensitivity to ET-1, elevated resting LV wall tension, and decreased coronary smooth muscle cell Ca(2+)-sensitive I(K(+)) was found in sedentary animals with LV hypertrophy. Low-intensity interval exercise training preserved normal coronary vascular function and smooth muscle cell Ca(2+)-sensitive I(K(+)), illustrating a potential mechanism underlying coronary vascular dysfunction in a large-animal model of LV hypertrophy. Our results demonstrate the potential clinical impact of exercise on coronary vascular function in HF patients displaying pathological LV hypertrophy.
Roots of two transcendental equations involving spherical bessel functions
International Nuclear Information System (INIS)
Pexton, R.L.; Steiger, A.D.
1977-01-01
Roots of the transcendental equations j/sub l/(αlambda) y/sub l/(lambda) =j/sub l/(lambda) y/sub l/(αlambda) and [xj/sub l/(x)]'/sub x alphaeta yl-italic/(x)]'/sub x eta/=xj/sub l/(x)]'/sub x eta yl-italic/(x)]'/sub x alphaeta/for the spherical Bessel functions of the first and second kind, j/sub l/(z) and y/sub l/(z), have been computed. The ranges for the parameter α, the order l and the root index n are: α=0.1(0.1)0.7,l=1(1)15,n=1(1)30
A general mixture theory. I. Mixtures of spherical molecules
Hamad, Esam Z.
1996-08-01
We present a new general theory for obtaining mixture properties from the pure species equations of state. The theory addresses the composition and the unlike interactions dependence of mixture equation of state. The density expansion of the mixture equation gives the exact composition dependence of all virial coefficients. The theory introduces multiple-index parameters that can be calculated from binary unlike interaction parameters. In this first part of the work, details are presented for the first and second levels of approximations for spherical molecules. The second order model is simple and very accurate. It predicts the compressibility factor of additive hard spheres within simulation uncertainty (equimolar with size ratio of three). For nonadditive hard spheres, comparison with compressibility factor simulation data over a wide range of density, composition, and nonadditivity parameter, gave an average error of 2%. For mixtures of Lennard-Jones molecules, the model predictions are better than the Weeks-Chandler-Anderson perturbation theory.
The homogeneous boundary value problem of the thick spherical shell
International Nuclear Information System (INIS)
Linder, F.
1975-01-01
With the aim to solve boundary value problems in the same manner as it is attained at thin shell theory (Superposition of Membrane solution to solution of boundary values), one has to search solutions of the equations of equilibrium of the three dimensional thick shell which produce tensions at the cut edge and are zero on the whole shell surface inside and outside. This problem was solved with the premissions of the linear theory of Elasticity. The gained solution is exact and contains the symmetric and non-symmetric behaviour and is described in relatively short analytical expressions for the deformations and tensions, after the problem of the coupled system had been solved. The static condition of the two surfaces (zero tension) leads to a homogeneous system of complex equations with the index of the Legendre spherical function as Eigenvalue. One symmetrical case is calculated numerically and is compared with the method of finite elements. This comparison results in good accordance. (Auth.)
Novel Electrically Small Spherical Electric Dipole Antenna
DEFF Research Database (Denmark)
Kim, Oleksiy S.
2010-01-01
This paper introduces a novel electrically small spherical meander antenna. Horizontal sections of the meander are composed of wire loops, radii of which are chosen so that the whole structure is conformal to a sphere of radius a. To form the meander the loops are connected by wires at a meridian...
Preparations of spherical polymeric particles from Tanzanian ...
African Journals Online (AJOL)
Spherical Polymeric Particles (SPP) have been prepared from Tanzanian Cashew Nut Shell Liquid (CNSL) by suspension polymerization technique involving either step-growth or chain- growth polymerization mechanisms. The sizes of the SPP, which ranged from 0.1 to 2.0 mm were strongly influenced by the amounts of ...
Sphericity in the interacting boson model
International Nuclear Information System (INIS)
Ogata, H.
1977-01-01
The interacting boson model (IBM) of Arima and Iachello is examined. The transition between the rotational and vibrational modes of even-even nuclei is presented as a function of a sphericity parameter, which is determined primarily from yrast band spectra. The backbending feature is reasonably reproduced. (author)
Exact solutions of the spherically symmetric multidimensional ...
African Journals Online (AJOL)
The complete orthonormalised energy eigenfunctions and the energy eigenvalues of the spherically symmetric isotropic harmonic oscillator in N dimensions, are obtained through the methods of separation of variables. Also, the degeneracy of the energy levels are examined. KEY WORDS: - Schrödinger Equation, Isotropic ...
Added Mass of a Spherical Cap Body
Czech Academy of Sciences Publication Activity Database
Šimčík, Miroslav; Punčochář, Miroslav; Růžička, Marek
2014-01-01
Roč. 118, OCT 18 (2014), s. 1-8 ISSN 0009-2509 R&D Projects: GA MŠk(CZ) LD13018 Institutional support: RVO:67985858 Keywords : spherical cap * added mass * single particle Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.337, year: 2014
Effective pair potentials for spherical nanoparticles
International Nuclear Information System (INIS)
Van Zon, Ramses
2009-01-01
An effective description for rigid spherical nanoparticles in a fluid of point particles is presented. The points inside the nanoparticles and the point particles are assumed to interact via spherically symmetric additive pair potentials, while the distribution of points inside the nanoparticles is taken to be spherically symmetric and smooth. The resulting effective pair interactions between a nanoparticle and a point particle, as well as between two nanoparticles, are then given by spherically symmetric potentials. If overlap between particles is allowed, as can occur for some forms of the pair potentials, the effective potential generally has non-analytic points. It is shown that for each effective potential the expressions for different overlapping cases can be written in terms of one analytic auxiliary potential. Even when only non-overlapping situations are possible, the auxiliary potentials facilitate the formulation of the effective potentials. Effective potentials for hollow nanoparticles (appropriate e.g. for buckyballs) are also considered and shown to be related to those for solid nanoparticles. For hollow nanoparticles overlap is more physical, since this covers the case of a smaller particle embedded in a larger, hollow nanoparticle. Finally, explicit expressions are given for the effective potentials derived from basic pair potentials of power law and exponential form, as well as from the commonly used London–van der Waals, Morse, Buckingham, and Lennard-Jones potentials. The applicability of the latter is demonstrated by comparison with an atomic description of nanoparticles with an internal face centered cubic structure
MAST: a Mega Amp Spherical Tokamak
International Nuclear Information System (INIS)
Darke, A.C.; Harbar, J.R.; Hay, J.H.; Hicks, J.B.; Hill, J.W.; McKenzie, J.S.; Morris, A.W.; Nightingale, M.P.S.; Todd, T.N.; Voss, G.M.; Watkins, J.R.
1995-01-01
The highly successful tight aspect ratio tokamak research pioneered on the START machine at Culham, together with the attractive possibilities of the concept, suggest a larger device should be considered. The design of a Mega Amp Spherical Tokamak is described, operating at much higher currents and over longer pulses than START and compatible with strong additional heating. (orig.)
A Generalization of the Spherical Inversion
Ramírez, José L.; Rubiano, Gustavo N.
2017-01-01
In the present article, we introduce a generalization of the spherical inversion. In particular, we define an inversion with respect to an ellipsoid, and prove several properties of this new transformation. The inversion in an ellipsoid is the generalization of the elliptic inversion to the three-dimensional space. We also study the inverse images…
Sparse acoustic imaging with a spherical array
DEFF Research Database (Denmark)
Fernandez Grande, Efren; Xenaki, Angeliki
2015-01-01
In recent years, a number of methods for sound source localization and sound field reconstruction with spherical microphone arrays have been proposed. These arrays have properties that are potentially very useful, e.g. omni-directionality, robustness, compensable scattering, etc. This paper propo...
Spherical torus, compact fusion at low field
International Nuclear Information System (INIS)
Peng, Y.K.M.
1985-02-01
A spherical torus is obtained by retaining only the indispensable components on the inboard side of a tokamak plasma, such as a cooled, normal conductor that carries current to produce a toroidal magnetic field. The resulting device features an exceptionally small aspect ratio (ranging from below 2 to about 1.3), a naturally elongated D-shaped plasma cross section, and ramp-up of the plasma current primarily by noninductive means. As a result of the favorable dependence of the tokamak plasma behavior to decreasing aspect ratio, a spherical torus is projected to have small size, high beta, and modest field. Assuming Mirnov confinement scaling, an ignition spherical torus at a field of 2 T features a major radius of 1.5 m, a minor radius of 1.0 m, a plasma current of 14 MA, comparable toroidal and poloidal field coil currents, an average beta of 24%, and a fusion power of 50 MW. At 2 T, a Q = 1 spherical torus will have a major radius of 0.8 m, a minor radius of 0.5 m, and a fusion power of a few megawatts
Maceo Heilman, Bianca; Manns, Fabrice; de Castro, Alberto; Durkee, Heather; Arrieta, Esdras; Marcos, Susana; Parel, Jean-Marie
2015-02-10
The purpose of this study was to quantify accommodation-induced changes in the spherical aberration of cynomolgus monkey lenses. Twenty-four lenses from 20 cynomolgus monkeys (Macaca fascicularis; 4.4-16.0 years of age; postmortem time 13.5 ± 13.0 hours) were mounted in a lens stretcher. Lens spherical aberration was measured in the unstretched (accommodated) and stretched (relaxed) states with a laser ray tracing system that delivered 51 equally spaced parallel rays along 1 meridian of the lens over the central 6-mm optical zone. A camera mounted below the lens was used to measure the ray height at multiple positions along the optical axis. For each entrance ray, the change in ray height with axial position was fitted with a third-order polynomial. The effective paraxial focal length and Zernike spherical aberration coefficients corresponding to a 6-mm pupil diameter were extracted from the fitted values. The unstretched lens power decreased with age from 59.3 ± 4.0 diopters (D) for young lenses to 45.7 ± 3.1 D for older lenses. The unstretched lens shifted toward less negative spherical aberration with age, from -6.3 ± 0.7 μm for young lenses to -5.0 ± 0.5 μm for older lenses. The power and spherical aberration of lenses in the stretched state were independent of age, with values of 33.5 ± 3.4 D and -2.6 ± 0.5 μm, respectively. Spherical aberration is negative in cynomolgus monkey lenses and becomes more negative with accommodation. These results are in good agreement with the predicted values using computational ray tracing in a lens model with a reconstructed gradient refractive index. The spherical aberration of the unstretched lens becomes less negative with age. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
The Walkability Index dataset characterizes every Census 2010 block group in the U.S. based on its relative walkability. Walkability depends upon characteristics of the built environment that influence the likelihood of walking being used as a mode of travel. The Walkability Index is based on the EPA's previous data product, the Smart Location Database (SLD). Block group data from the SLD was the only input into the Walkability Index, and consisted of four variables from the SLD weighted in a formula to create the new Walkability Index. This dataset shares the SLD's block group boundary definitions from Census 2010. The methodology describing the process of creating the Walkability Index can be found in the documents located at ftp://newftp.epa.gov/EPADataCommons/OP/WalkabilityIndex.zip. You can also learn more about the Smart Location Database at https://edg.epa.gov/data/Public/OP/Smart_Location_DB_v02b.zip.
DEFF Research Database (Denmark)
Møller, J E; Søndergaard, E; Poulsen, S H
2001-01-01
To investigate the value of the Doppler-derived myocardial performance index to predict early left-ventricular (LV) dilation and cardiac death after a first acute myocardial infarction (AMI), Doppler echocardiography was performed within 24 h of hospital admission, on day 5, 1 and 3 months after...... AMI in 125 consecutive patients. The index measured on day 1 correlated well with the change in end-diastolic volume index observed from day 1 to 3 months following AMI (r = 0.66, p 0.0001). One-year survival in patients with Doppler index index > or = 0......, we conclude that the Doppler echocardiographic myocardial performance index is a predictor of LV dilation and cardiac death after a first AMI....
Directory of Open Access Journals (Sweden)
Katja Hueper
Full Text Available To quantify resting myocardial blood flow (MBF in the left ventricular (LV wall of HCM patients and to determine the relationship to important parameters of disease: LV wall thickness, late gadolinium enhancement (LGE, T2-signal abnormalities (dark and bright signal, LV outflow tract obstruction and age.Seventy patients with proven HCM underwent cardiac MRI. Absolute and relative resting MBF were calculated from cardiac perfusion MRI by using the Fermi function model. The relationship between relative MBF and LV wall thickness, T2-signal abnormalities (T2 dark and T2 bright signal, LGE, age and LV outflow gradient as determined by echocardiography was determined using simple and multiple linear regression analysis. Categories of reduced and elevated perfusion in relation to non- or mildly affected reference segments were defined, and T2-signal characteristics and extent as well as pattern of LGE were examined. Statistical testing included linear and logistic regression analysis, unpaired t-test, odds ratios, and Fisher's exact test.804 segments in 70 patients were included in the analysis. In a simple linear regression model LV wall thickness (p<0.001, extent of LGE (p<0.001, presence of edema, defined as focal T2 bright signal (p<0.001, T2 dark signal (p<0.001 and age (p = 0.032 correlated inversely with relative resting MBF. The LV outflow gradient did not show any effect on resting perfusion (p = 0.901. Multiple linear regression analysis revealed that LGE (p<0.001, edema (p = 0.026 and T2 dark signal (p = 0.019 were independent predictors of relative resting MBF. Segments with reduced resting perfusion demonstrated different LGE patterns compared to segments with elevated resting perfusion.In HCM resting MBF is significantly reduced depending on LV wall thickness, extent of LGE, focal T2 signal abnormalities and age. Furthermore, different patterns of perfusion in HCM patients have been defined, which may represent different stages of
Spherical Bessel transform via exponential sum approximation of spherical Bessel function
Ikeno, Hidekazu
2018-02-01
A new algorithm for numerical evaluation of spherical Bessel transform is proposed in this paper. In this method, the spherical Bessel function is approximately represented as an exponential sum with complex parameters. This is obtained by expressing an integral representation of spherical Bessel function in complex plane, and discretizing contour integrals along steepest descent paths and a contour path parallel to real axis using numerical quadrature rule with the double-exponential transformation. The number of terms in the expression is reduced using the modified balanced truncation method. The residual part of integrand is also expanded by exponential functions using Prony-like method. The spherical Bessel transform can be evaluated analytically on arbitrary points in half-open interval.
National Oceanic and Atmospheric Administration, Department of Commerce — Planetary Amplitude index - Bartels 1951. The a-index ranges from 0 to 400 and represents a K-value converted to a linear scale in gammas (nanoTeslas)--a scale that...
Non-conformal contact mechanical characteristic analysis on spherical components
Energy Technology Data Exchange (ETDEWEB)
Zhen-zhi, G.; Bin, H.; Zheng-ming, G.; Feng-mei, Y.; Jin, Q [The 2. Artillery Engineering Univ., Xi' an (China)
2017-03-15
Non-conformal spherical-contact mechanical problems is a three-dimensional coordination or similar to the coordination spherical contact. Due to the complexity of the problem of spherical-contact and difficulties of solving higher-order partial differential equations, problems of three-dimensional coordination or similar to the coordination spherical-contact is still no exact analytical method for solving. It is based on three-dimensional taper model is proposed a model based on the contour surface of the spherical contact and concluded of the formula of the contact pressure and constructed of finite element model by contact pressure distribution under the non-conformal spherical. The results shows spherical contact model can reflect non-conformal spherical-contacting mechanical problems more than taper-contacting model, and apply for the actual project.
Normal modes and quality factors of spherical dielectric resonators: I ...
Indian Academy of Sciences (India)
Eigenmodes; spherical resonators; spherical dielectric resonators; quality factors. PACS No. 42.50. .... Alternatively, introducing the angular momentum operator L defined as, L = (1/j)( r × ∇) ...... referee of the article for some helpful comments.
Quality metric for spherical panoramic video
Zakharchenko, Vladyslav; Choi, Kwang Pyo; Park, Jeong Hoon
2016-09-01
Virtual reality (VR)/ augmented reality (AR) applications allow users to view artificial content of a surrounding space simulating presence effect with a help of special applications or devices. Synthetic contents production is well known process form computer graphics domain and pipeline has been already fixed in the industry. However emerging multimedia formats for immersive entertainment applications such as free-viewpoint television (FTV) or spherical panoramic video require different approaches in content management and quality assessment. The international standardization on FTV has been promoted by MPEG. This paper is dedicated to discussion of immersive media distribution format and quality estimation process. Accuracy and reliability of the proposed objective quality estimation method had been verified with spherical panoramic images demonstrating good correlation results with subjective quality estimation held by a group of experts.
Simplified discrete ordinates method in spherical geometry
International Nuclear Information System (INIS)
Elsawi, M.A.; Abdurrahman, N.M.; Yavuz, M.
1999-01-01
The authors extend the method of simplified discrete ordinates (SS N ) to spherical geometry. The motivation for such an extension is that the appearance of the angular derivative (redistribution) term in the spherical geometry transport equation makes it difficult to decide which differencing scheme best approximates this term. In the present method, the angular derivative term is treated implicitly and thus avoids the need for the approximation of such term. This method can be considered to be analytic in nature with the advantage of being free from spatial truncation errors from which most of the existing transport codes suffer. In addition, it treats the angular redistribution term implicitly with the advantage of avoiding approximations to that term. The method also can handle scattering in a very general manner with the advantage of spending almost the same computational effort for all scattering modes. Moreover, the methods can easily be applied to higher-order S N calculations
Spherical harmonics and integration in superspace
International Nuclear Information System (INIS)
Bie, H de; Sommen, F
2007-01-01
In this paper, the classical theory of spherical harmonics in R m is extended to superspace using techniques from Clifford analysis. After defining a super-Laplace operator and studying some basic properties of polynomial null-solutions of this operator, a new type of integration over the supersphere is introduced by exploiting the formal equivalence with an old result of Pizzetti. This integral is then used to prove orthogonality of spherical harmonics of different degree, Green-like theorems and also an extension of the important Funk-Hecke theorem to superspace. Finally, this integration over the supersphere is used to define an integral over the whole superspace, and it is proven that this is equivalent with the Berezin integral, thus providing a more sound definition of the Berezin integral
Spherical projections and liftings in geometric tomography
DEFF Research Database (Denmark)
Goodey, Paul; Kiderlen, Markus; Weil, Wolfgang
2011-01-01
We consider a variety of integral transforms arising in Geometric Tomography. It will be shown that these can be put into a common framework using spherical projection and lifting operators. These operators will be applied to support functions and surface area measures of convex bodies and to rad......We consider a variety of integral transforms arising in Geometric Tomography. It will be shown that these can be put into a common framework using spherical projection and lifting operators. These operators will be applied to support functions and surface area measures of convex bodies...... and to radial functions of star bodies. We then investigate averages of lifted projections and show that they correspond to self-adjoint intertwining operators. We obtain formulas for the eigenvalues of these operators and use them to ascertain circumstances under which tomographic measurements determine...... the original bodies. This approach via mean lifted projections leads us to some unexpected relationships between seemingly disparate geometric constructions....
Spherical Cancer Models in Tumor Biology
Directory of Open Access Journals (Sweden)
Louis-Bastien Weiswald
2015-01-01
Full Text Available Three-dimensional (3D in vitro models have been used in cancer research as an intermediate model between in vitro cancer cell line cultures and in vivo tumor. Spherical cancer models represent major 3D in vitro models that have been described over the past 4 decades. These models have gained popularity in cancer stem cell research using tumorospheres. Thus, it is crucial to define and clarify the different spherical cancer models thus far described. Here, we focus on in vitro multicellular spheres used in cancer research. All these spherelike structures are characterized by their well-rounded shape, the presence of cancer cells, and their capacity to be maintained as free-floating cultures. We propose a rational classification of the four most commonly used spherical cancer models in cancer research based on culture methods for obtaining them and on subsequent differences in sphere biology: the multicellular tumor spheroid model, first described in the early 70s and obtained by culture of cancer cell lines under nonadherent conditions; tumorospheres, a model of cancer stem cell expansion established in a serum-free medium supplemented with growth factors; tissue-derived tumor spheres and organotypic multicellular spheroids, obtained by tumor tissue mechanical dissociation and cutting. In addition, we describe their applications to and interest in cancer research; in particular, we describe their contribution to chemoresistance, radioresistance, tumorigenicity, and invasion and migration studies. Although these models share a common 3D conformation, each displays its own intrinsic properties. Therefore, the most relevant spherical cancer model must be carefully selected, as a function of the study aim and cancer type.
Fusion technology applications of the spherical tokamak
International Nuclear Information System (INIS)
Robinson, D.C.; Akers, R.; Allfrey, S.J.
1999-01-01
Fusion technology applications of the spherical tokamak are presented, exploiting its high β capability, normal conducting TF coils, compact core, high natural elongation, disruption resilience and low capital cost. We concentrate here on two particular applications: a volume neutron source (VNS) for component testing and a power plant, addressing engineering and physics issues for steady state operation. The prospect of nearer term burning plasma ST devices are discussed in the conclusions. (author)
Fusion technology applications of the spherical tokamak
International Nuclear Information System (INIS)
Robinson, D.C.; Akers, R.; Allfrey, S.J.
2001-01-01
Fusion technology applications of the spherical tokamak are presented, exploiting its high β capability, normal conducting TF coils, compact core, high natural elongation, disruption resilience and low capital cost. We concentrate here on two particular applications: a volume neutron source (VNS) for component testing and a power plant, addressing engineering and physics issues for steady state operation. The prospect of nearer term burning plasma ST devices are discussed in the conclusions. (author)
Particles in spherical electromagnetic radiation fields
International Nuclear Information System (INIS)
Mitter, H.; Thaller, B.
1984-03-01
If the time-dependence of a Hamiltonian can be compensated by an appropriate symmetry transformation, the corresponding quantum mechanical problem can be reduced to an effectively stationary one. With this result we investigate the behavior of nonrelativistic particles in a spherical radiation field produced by a rotating source. Then the symmetry transformation corresponds to a rotation. We calculate the transition probabilities in Born approximation. The extension to problems involving an additional Coulomb potential is briefly discussed. (Author)
New mathematical framework for spherical gravitational collapse
International Nuclear Information System (INIS)
Giambo, Roberto; Giannoni, Fabio; Magli, Giulio; Piccione, Paolo
2003-01-01
A theorem, giving necessary and sufficient condition for naked singularity formation in spherically symmetric non-static spacetimes under hypotheses of physical acceptability, is formulated and proved. The theorem relates the existence of singular null geodesics to the existence of regular curves which are supersolutions of the radial null geodesic equation, and allows us to treat all the known examples of naked singularities from a unified viewpoint. New examples are also found using this approach, and perspectives are discussed. (letter to the editor)
Particle Entrainment in Spherical-Cap Wakes
Energy Technology Data Exchange (ETDEWEB)
Warncke, Norbert G W; Delfos, Rene; Ooms, Gijs; Westerweel, Jerry, E-mail: n.g.w.warncke@tudelft.nl [Laboratory for Aero- and Hydrodynamics, Delft University of Technology (Netherlands)
2011-12-22
In this work we study the preferential concentration of small particles in the turbulent wake behind a spherical-cap object. We present a model predicting the mean particle concentration in the near-wake as a function of the characteristic Stokes number of the problem, the turbulence level and the Froude number. We compare the model with our experimental results on this flow, measured in a vertical water tunnel.
Spherical tokamak without external toroidal fields
International Nuclear Information System (INIS)
Kaw, P.K.; Avinash, K.; Srinivasan, R.
2001-01-01
A spherical tokamak design without external toroidal field coils is proposed. The tokamak is surrounded by a spheromak shell carrying requisite force free currents to produce the toroidal field in the core. Such equilibria are constructed and it is indicated that these equilibria are likely to have robust ideal and resistive stability. The advantage of this scheme in terms of a reduced ohmic dissipation is pointed out. (author)
All silicon waveguide spherical microcavity coupler device.
Xifré-Pérez, E; Domenech, J D; Fenollosa, R; Muñoz, P; Capmany, J; Meseguer, F
2011-02-14
A coupler based on silicon spherical microcavities coupled to silicon waveguides for telecom wavelengths is presented. The light scattered by the microcavity is detected and analyzed as a function of the wavelength. The transmittance signal through the waveguide is strongly attenuated (up to 25 dB) at wavelengths corresponding to the Mie resonances of the microcavity. The coupling between the microcavity and the waveguide is experimentally demonstrated and theoretically modeled with the help of FDTD calculations.
Angular shift in scattering the spherical analogous of the Goos-Hanchen effect
International Nuclear Information System (INIS)
Ferrari Junior, N.F.; Nussenzveig, H.M.
1983-01-01
A generalization of the time and spatial delay concept is obtained, for the scattering of transversaly incident beam restricted by a spherically symmetric scatterer using the methods of the complex angular momentum, valid for the angular momentum and angle conjufated variable pair. The result obtained is known validity domain, within the semiclassical approximation. Applied to the scttering problem in the high frequency limit by a transparent sphere with refractive index N [pt
Indicators of Mass in Spherical Stellar Atmospheres
Lester, John B.; Dinshaw, Rayomond; Neilson, Hilding R.
2013-04-01
Mass is the most important stellar parameter, but it is not directly observable for a single star. Spherical model stellar atmospheres are explicitly characterized by their luminosity ( L⋆), mass ( M⋆), and radius ( R⋆), and observations can now determine directly L⋆ and R⋆. We computed spherical model atmospheres for red giants and for red supergiants holding L⋆ and R⋆ constant at characteristic values for each type of star but varying M⋆, and we searched the predicted flux spectra and surface-brightness distributions for features that changed with mass. For both stellar classes we found similar signatures of the stars’ mass in both the surface-brightness distribution and the flux spectrum. The spectral features have been use previously to determine log 10(g), and now that the luminosity and radius of a non-binary red giant or red supergiant can be observed, spherical model stellar atmospheres can be used to determine a star’s mass from currently achievable spectroscopy. The surface-brightness variations of mass are slightly smaller than can be resolved by current stellar imaging, but they offer the advantage of being less sensitive to the detailed chemical composition of the atmosphere.
Fusion potential for spherical and compact tokamaks
International Nuclear Information System (INIS)
Sandzelius, Mikael
2003-02-01
The tokamak is the most successful fusion experiment today. Despite this, the conventional tokamak has a long way to go before being realized into an economically viable power plant. In this master thesis work, two alternative tokamak configurations to the conventional tokamak has been studied, both of which could be realized to a lower cost. The fusion potential of the spherical and the compact tokamak have been examined with a comparison of the conventional tokamak in mind. The difficulties arising in the two configurations have been treated from a physical point of view concerning the fusion plasma and from a technological standpoint evolving around design, materials and engineering. Both advantages and drawbacks of either configuration have been treated relative to the conventional tokamak. The spherical tokamak shows promising plasma characteristics, notably a high β-value but have troubles with high heat loads and marginal tritium breeding. The compact tokamak operates at a high plasma density and a high magnetic field enabling it to be built considerably smaller than any other tokamak. The most notable down-side being high heat loads and neutron transport problems. With the help of theoretical reactor studies, extrapolating from where we stand today, it is conceivable that the spherical tokamak is closer of being realized of the two. But, as this study shows, the compact tokamak power plant concept offers the most appealing prospect
Fusion potential for spherical and compact tokamaks
Energy Technology Data Exchange (ETDEWEB)
Sandzelius, Mikael
2003-02-01
The tokamak is the most successful fusion experiment today. Despite this, the conventional tokamak has a long way to go before being realized into an economically viable power plant. In this master thesis work, two alternative tokamak configurations to the conventional tokamak has been studied, both of which could be realized to a lower cost. The fusion potential of the spherical and the compact tokamak have been examined with a comparison of the conventional tokamak in mind. The difficulties arising in the two configurations have been treated from a physical point of view concerning the fusion plasma and from a technological standpoint evolving around design, materials and engineering. Both advantages and drawbacks of either configuration have been treated relative to the conventional tokamak. The spherical tokamak shows promising plasma characteristics, notably a high {beta}-value but have troubles with high heat loads and marginal tritium breeding. The compact tokamak operates at a high plasma density and a high magnetic field enabling it to be built considerably smaller than any other tokamak. The most notable down-side being high heat loads and neutron transport problems. With the help of theoretical reactor studies, extrapolating from where we stand today, it is conceivable that the spherical tokamak is closer of being realized of the two. But, as this study shows, the compact tokamak power plant concept offers the most appealing prospect.
Collisions of droplets on spherical particles
Charalampous, Georgios; Hardalupas, Yannis
2017-10-01
Head-on collisions between droplets and spherical particles are examined for water droplets in the diameter range between 170 μm and 280 μm and spherical particles in the diameter range between 500 μm and 2000 μm. The droplet velocities range between 6 m/s and 11 m/s, while the spherical particles are fixed in space. The Weber and Ohnesorge numbers and ratio of droplet to particle diameter were between 92 deposition and splashing regimes, a regime is observed in the intermediate region, where the droplet forms a stable crown, which does not breakup but propagates along the particle surface and passes around the particle. This regime is prevalent when the droplets collide on small particles. The characteristics of the collision at the onset of rim instability are also described in terms of the location of the film on the particle surface and the orientation and length of the ejected crown. Proper orthogonal decomposition identified that the first 2 modes are enough to capture the overall morphology of the crown at the splashing threshold.
Next Step Spherical Torus Design Studies
International Nuclear Information System (INIS)
Neumeyer, C.; Heitzenroeder, P.; Kessel, C.; Ono, M.; Peng, M.; Schmidt, J.; Woolley, R.; Zatz, I.
2002-01-01
Studies are underway to identify and characterize a design point for a Next Step Spherical Torus (NSST) experiment. This would be a ''Proof of Performance'' device which would follow and build upon the successes of the National Spherical Torus Experiment (NSTX) a ''Proof of Principle'' device which has operated at PPPL since 1999. With the Decontamination and Decommissioning (DandD) of the Tokamak Fusion Test Reactor (TFTR) nearly completed, the TFTR test cell and facility will soon be available for a device such as NSST. By utilizing the TFTR test cell, NSST can be constructed for a relatively low cost on a short time scale. In addition, while furthering spherical torus (ST) research, this device could achieve modest fusion power gain for short-pulse lengths, a significant step toward future large burning plasma devices now under discussion in the fusion community. The selected design point is Q=2 at HH=1.4, P subscript ''fusion''=60 MW, 5 second pulse, with R subscript ''0''=1.5 m, A=1.6, I subscript ''p''=10vMA, B subscript ''t''=2.6 T, CS flux=16 weber. Most of the research would be conducted in D-D, with a limited D-T campaign during the last years of the program
Integrals of products of spherical functions
International Nuclear Information System (INIS)
Veverka, O.
1975-01-01
Various branches of mathematical physics use integral formulas of the products of spherical functions. In quantum mechanics and in transport theory the integrals ∫sub((4π))dΩ vectorYsub(s)sup(t)(Ω vector)Ysub(l)sup(k)(Ω vector)Ysub(n)sup(m)(Ω vector), ∫sub(-1)sup(1)dμPsub(s)sup(t)(μ)Psub(l)sup(k)(μ)Psub(n)sup(m)(μ), ∫sub(-1)sup(1)dμPsub(s)(μ)Psub(l)(μ)Psub(n)(μ) are generally applied, where Ysub(α)sup(β)(Ω vector) are spherical harmonics, Psub(α)sup(β)(μ) are associated Legendre functions, and Psub(α)(μ) are Legendre polynomials. In the paper, the general procedure of calculating the integrals of the products of any combination of spherical functions is given. The procedure is referred to in a report on the boundary conditions for the cylindrical geometry in neutron transport theory for both the outer and inner cylindrical boundaries. (author)
Directory of Open Access Journals (Sweden)
Ane S. Simionato
2017-06-01
Full Text Available One of the most important postharvest plant pathogens that affect strawberries, grapes and tomatoes is Botrytis cinerea, known as gray mold. The fungus remains in latent form until spore germination conditions are good, making infection control difficult, causing great losses in the whole production chain. This study aimed to purify and identify phenazine-1-carboxylic acid (PCA produced by the Pseudomonas aeruginosa LV strain and to determine its antifungal activity against B. cinerea. The compounds produced were extracted with dichloromethane and passed through a chromatographic process. The purity level of PCA was determined by reversed-phase high-performance liquid chromatography semi-preparative. The structure of PCA was confirmed by nuclear magnetic resonance and electrospray ionization mass spectrometry. Antifungal activity was determined by the dry paper disk and minimum inhibitory concentration (MIC methods and identified by scanning electron microscopy and confocal microscopy. The results showed that PCA inhibited mycelial growth, where MIC was 25 μg mL-1. Microscopic analysis revealed a reduction in exopolysaccharide (EPS formation, showing distorted and damaged hyphae of B. cinerea. The results suggested that PCA has a high potential in the control of B. cinerea and inhibition of EPS (important virulence factor. This natural compound is a potential alternative to postharvest control of gray mold disease.
Directory of Open Access Journals (Sweden)
Ajay Kumar
2010-01-01
Full Text Available Dumbbell oligonucleotides with loops of various chemistry were synthesized. Incubation of dumbbell oligonucleotides containing phosphorothioate bonds or trimethylene phosphate linkages in loops with S1 nuclease did not result in significant cleavage under conditions which led to the degradation of dumbbell oligonucleotide containing phophodiester bonds in the loops. The binding of reverse transcriptase of Moloney Murine Leukemia Virus (MoMuLV was evaluated with all the five oligonucleotides. The protein binds to all the dumbbell oligonucleotides with similar affinity. The dissociation constants evaluated using PAGE band mobility shift assays were of the order of 10-7. The inhibitory properties of the retroviral RNase H activity was evaluated using 3H –UTP-labeled RNA:RNA-DNA hybrid. It was found that the best dumbbell oligonucleotide, inhibitor contained phosphorothioate residues in both the loops. Our value studies demonstrated that this particularly designed oligonucleotide displays an IC50 of 18 nM in its inhibition on the reverse transcriptase RNase H activity, a magnitude lower than that of first nucleotide reverse transcriptase of HIV-1, tenofovir, introduced by Gilead Science in the market.
Strauss, Margit; Kouraki, Kleopatra; Skarlos, Alexandros; Zahn, Ralf; Kleemann, Thomas
2013-06-01
The wearable cardioverter-defibrillator (WCD) is indicated in patients who are considered to be at temporarily high risk for sudden cardiac death (SCD), when an implantable defibrillator is not yet clearly indicated. We report the case of a 41-year-old patient with a newly diagnosed severely reduced left ventricular (LV) function for suspected myocarditis and repeated nonsustained ventricular tachycardia (VT). This patient was supplied with a WCD who came back to the hospital 4 weeks after discharge with an electrical storm and adequate discharge of the WCD. After application of amiodarone, no further arrhythmias were detected during intrahospital course. For further risk stratification, we performed a magnetic field imaging (MFI), that was reported to be useful in risk assessment of SCD in patients with ischemic cardiomyopathy. This measurement showed a normal result, but we decided to give an implantable cardioverter-defibrillator (ICD) to the patient. During a follow-up of 1 year, no further arrhythmias occurred. With this case, we report the efficacy of a WCD, which is a novel tool in patients at temporarily high risk of SCD and we report a novel method of risk stratification in patients with a high risk of SCD.
Jing, Fulong; Jiao, Shuhong; Hou, Changbo; Si, Weijian; Wang, Yu
2017-06-21
For targets with complex motion, such as ships fluctuating with oceanic waves and high maneuvering airplanes, azimuth echo signals can be modeled as multicomponent quadratic frequency modulation (QFM) signals after migration compensation and phase adjustment. For the QFM signal model, the chirp rate (CR) and the quadratic chirp rate (QCR) are two important physical quantities, which need to be estimated. For multicomponent QFM signals, the cross terms create a challenge for detection, which needs to be addressed. In this paper, by employing a novel multi-scale parametric symmetric self-correlation function (PSSF) and modified scaled Fourier transform (mSFT), an effective parameter estimation algorithm is proposed-referred to as the Two-Dimensional product modified Lv's distribution (2D-PMLVD)-for QFM signals. The 2D-PMLVD is simple and can be easily implemented by using fast Fourier transform (FFT) and complex multiplication. These measures are analyzed in the paper, including the principle, the cross term, anti-noise performance, and computational complexity. Compared to the other three representative methods, the 2D-PMLVD can achieve better anti-noise performance. The 2D-PMLVD, which is free of searching and has no identifiability problems, is more suitable for multicomponent situations. Through several simulations and analyses, the effectiveness of the proposed estimation algorithm is verified.
National Oceanic and Atmospheric Administration, Department of Commerce — The geomagnetic aa index provides a long climatology of global geomagnetic activity using 2 antipodal observatories at Greenwich and Melbourne- IAGA Bulletin 37,...
U.S. Environmental Protection Agency — The Walkability Index dataset characterizes every Census 2010 block group in the U.S. based on its relative walkability. Walkability depends upon characteristics of...
Town of Chapel Hill, North Carolina — This map service summarizes racial and ethnic diversity in the United States in 2012.The Diversity Index shows the likelihood that two persons chosen at random from...
Indian Academy of Sciences (India)
a granitic terrain of southern India using factor analysis and GIS. 1059. Radhakrishna M see Dev Sheena V .... Landslide susceptibility analysis using Probabilistic. Certainty Factor ... index via entropy-difference analysis. 687. Yidana Sandow ...
Funabashi, Nobusada; Takaoka, Hiroyuki; Ozawa, Koya; Kamata, Tomoko; Uehara, Masae; Komuro, Issei; Kobayashi, Yoshio
2018-05-30
To achieve further risk stratification in hypertrophic cardiomyopathy (HCM) patients, we localized and quantified layer-specific LVM fibrosis on MRI in HCM patients using regional layer-specific peak longitudinal strain (PLS) and peak circumferential strain (PCS) in LV myocardium (LVM) on speckle tracking transthoracic echocardiography (TTE). A total of 18 HCM patients (14 males; 58 ± 17 years) underwent 1.5T-MRI and TTE. PLS and PCS in each layer of the LVM (endocardium, epicardium, and whole-layer myocardium) were calculated for 17 AHA-defined lesions. MRI assessment showed that fibrosis was classified as endocardial, epicardial, or whole-layer (= either or both of these). Regional PLS was smaller in fibrotic endocardial lesions than in non-fibrotic endocardial lesions (P = 0.004). To detect LV endocardial lesions with fibrosis, ROC curves of regional PLS revealed an area under the curve (AUC) of 0.609 and a best cut-off point of 13.5%, with sensitivity of 65.3% and specificity of 54.3%. Regional PLS was also smaller in fibrotic epicardial lesions than in non-fibrotic epicardial lesions (P layer myocardium analysis, PLS was smaller in fibrotic lesions than in non-fibrotic lesions (P layer LV lesions with fibrosis, ROC curves of regional PLS revealed an AUC of 0.674 and a best cut-off point of 12.5%, with sensitivity of 79.0% and specificity of 50.7%. There were no significant differences in PCS of LV myocardium (endocardium, epicardium, and whole-layer) between fibrotic and non-fibrotic lesions. Quantitative regional PLS but not PCS in LV endocardium, epicardium, and whole-layer myocardium provides useful non-invasive information for layer-specific localization of fibrosis in HCM patients.
International Nuclear Information System (INIS)
Farkas, J.
1992-01-01
In this paper we discuss the relevance of artificial intelligence to the automatic indexing of natural language text. We describe the use of domain-specific semantically-based thesauruses and address the problem of creating adequate knowledge bases for intelligent indexing systems. We also discuss the relevance of the Hilbert space ι 2 to the compact representation of documents and to the definition of the similarity of natural language texts. (author). 17 refs., 2 figs
Energy Technology Data Exchange (ETDEWEB)
Farkas, J
1993-12-31
In this paper we discuss the relevance of artificial intelligence to the automatic indexing of natural language text. We describe the use of domain-specific semantically-based thesauruses and address the problem of creating adequate knowledge bases for intelligent indexing systems. We also discuss the relevance of the Hilbert space {iota}{sup 2} to the compact representation of documents and to the definition of the similarity of natural language texts. (author). 17 refs., 2 figs.
Virginia ESI: INDEX (Index Polygons)
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all hardcopy cartographic products produced as part of the Environmental Sensitivity Index...
Watermarking on 3D mesh based on spherical wavelet transform.
Jin, Jian-Qiu; Dai, Min-Ya; Bao, Hu-Jun; Peng, Qun-Sheng
2004-03-01
In this paper we propose a robust watermarking algorithm for 3D mesh. The algorithm is based on spherical wavelet transform. Our basic idea is to decompose the original mesh into a series of details at different scales by using spherical wavelet transform; the watermark is then embedded into the different levels of details. The embedding process includes: global sphere parameterization, spherical uniform sampling, spherical wavelet forward transform, embedding watermark, spherical wavelet inverse transform, and at last resampling the mesh watermarked to recover the topological connectivity of the original model. Experiments showed that our algorithm can improve the capacity of the watermark and the robustness of watermarking against attacks.
Liang, Gao-Feng; Liang, Yan; Xue, Qinggang; Lu, Jin-Feng; Cheng, Jun-Jun; Huang, Jie
2015-03-01
Cytokines play a critical role in innate and adaptive immunity. Astakines represent a group of invertebrate cytokines that are related to vertebrate prokineticin and function in promoting hematopoiesis in crustaceans. We have identified an astakine from the white shrimp Litopeneaus vannamei and named it LvAST in a previous research. In the present research, we investigated the interactions among LvAST, the envelope protein VP37 of white spot syndrome virus (i.e., WSSV), and the β subunit of F1-ATP synthase (ATPsyn-β) of the white shrimp (i.e., BP53) using binding assays and co-precipitations. We also examined the effects of LvAST on shrimp susceptibility to WSSV. We found that LvAST and VP37 competitively bound to BP53, but did not bind to each other. Shrimps that had been injected with recombinant LvAST exhibited significantly lower mortality and longer survival time in experimental infections by WSSV. In contrast, shrimps whose LvAST gene expression had been inhibited by RNA interference showed significantly higher WSSV infection intensity and shorter survival time following viral challenges. These results suggested that LvAST and WSSV both likely use ATPsyn-β as a receptor and LvAST plays a role in shrimp defense against WSSV infection. This represented the first research showing the involvement of astakines in host antiviral immunity. Copyright © 2014 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Wood, A.G.; Parker, G.E.; Berry, R.
1976-01-01
It is stated that the indexing mechanism described can be used in a nuclear reactor fuel element inspection rig. It comprises a tubular body adapted to house a canister containing a number of fuel elements located longtitudinally, and has two chucks spaced apart for displacing the fuel elements longitudinally in a stepwise manner, together with a plunger mechanism for displacing them successively into the chucks. A measuring unit is located between the chucks for measuring the diameter of the fuel elements at intervals about their circumferences, and a secondary indexing mechanism is provided for rotating the measuring unit in a stepwise manner. (U.K.)
Chiral pion dynamics for spherical nucleon bags
International Nuclear Information System (INIS)
Vento, V.; Rho, M.; Nyman, E.M.; Jun, J.H.; Brown, G.E.; CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette
1980-01-01
A chirally symmetric quark-bag model for the nucleon is obtained by introducing an explicit, classical, pion field exterior to the bag. The coupling at the bag surface is determined by the requirement of a conserved axial-vector current. The pion field satisfies equations of motion corresponding to the non-linear sigma-model. We study on this paper the simplified case where the bag and the pion field are spherically symmetric. Corrections due to gluon exchange between the quarks are ignored along with other interactions which split the N- and Δ-masses. The equations of motion for the pion field are solved and we find a substantial pion pressure at the bag surface, along with an attractive contribution to the nucleon self-energy. The total energy of the system, bag plus meson cloud, turns out to be approximately Msub(n)c 2 for a wide range of bag radii, from 1.5 fm down to about 0.5 fm. Introduction of a form factor for the pion would extend the range of possible radii to even smaller values. We propose that the bag with the smallest allowed radius be identified with the 'little bag' discussed before. One surprising result of the paper is that as long as one restricts to spherically symmetric bags, restoring chiral symmetry to the bag model makes the axial-vector current coupling constant gsub(A) to be always too large compared with the experimental value for any bag radius, suggesting a deviation from spherical symmetry for the intrinsic bag wave functions of the 'ground-state' hadrons. (orig.)
Spherically symmetric self-similar universe
Energy Technology Data Exchange (ETDEWEB)
Dyer, C C [Toronto Univ., Ontario (Canada)
1979-10-01
A spherically symmetric self-similar dust-filled universe is considered as a simple model of a hierarchical universe. Observable differences between the model in parabolic expansion and the corresponding homogeneous Einstein-de Sitter model are considered in detail. It is found that an observer at the centre of the distribution has a maximum observable redshift and can in principle see arbitrarily large blueshifts. It is found to yield an observed density-distance law different from that suggested by the observations of de Vaucouleurs. The use of these solutions as central objects for Swiss-cheese vacuoles is discussed.
The generalized spherical model of ferromagnetic films
International Nuclear Information System (INIS)
Costache, G.
1977-12-01
The D→ infinity of the D-vectorial model of a ferromagnetic film with free surfaces is exactly solved. The mathematical mechanism responsible for the onset of a phase transition in the system is a generalized sticking phenomenon. It is shown that the temperature at which the sticking appears, the transition temperature of the model is monotonously increasing with increasing the number of layers of the film, contrary to what happens in the spherical model with overall constraint. Certain correlation inequalities of Griffiths type are shown to hold. (author)
The spherical tokamak fusion power plant
International Nuclear Information System (INIS)
Wilson, H.R.; Voss, G.; Ahn, J.W.
2003-01-01
The design of a 1GW(e) steady state fusion power plant, based on the spherical tokamak concept, has been further iterated towards a fully self-consistent solution taking account of plasma physics, engineering and neutronics constraints. In particular a plausible solution to exhaust handling is proposed and the steam cycle refined to further improve efficiency. The physics design takes full account of confinement, MHD stability and steady state current drive. It is proposed that such a design may offer a fusion power plant which is easy to maintain: an attractive feature for the power plants following ITER. (author)
The status of the Brazilian spherical detector
International Nuclear Information System (INIS)
Aguiar, O D; Andrade, L A; Filho, L Camargo; Costa, C A; Araujo, J C N de; Neto, E C de Rey; Souza, S T de; Fauth, A C; Frajuca, C; Frossati, G; Furtado, S R; Furtado, V G S; Magalhaes, N S; Jr, R M Marinho; Matos, E S; Meliani, M T; Melo, J L; Miranda, O D; Jr, N F Oliveira; Ribeiro, K L; Salles, K B M; Stellati, C; Jr, W F Velloso
2002-01-01
The first phase of the Brazilian Graviton Project is the construction and operation of the gravitational wave detector Mario Schenberg at the Physics Institute of the University of Sao Paulo. This gravitational wave spherical antenna is planned to feature a sensitivity better than h = 10 -21 Hz -1/2 at the 3.0-3.4 kHz bandwidth, and to work not only as a detector, but also as a testbed for the development of new technologies. Here we present the status of this detector
Spherical conformal models for compact stars
Energy Technology Data Exchange (ETDEWEB)
Takisa, P.M.; Maharaj, S.D.; Manjonjo, A.M.; Moopanar, S. [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa)
2017-10-15
We consider spherical exact models for compact stars with anisotropic pressures and a conformal symmetry. The conformal symmetry condition generates an integral relationship between the gravitational potentials. We solve this condition to find a new anisotropic solution to the Einstein field equations. We demonstrate that the exact solution produces a relativistic model of a compact star. The model generates stellar radii and masses consistent with PSR J1614-2230, Vela X1, PSR J1903+327 and Cen X-3. A detailed physical examination shows that the model is regular, well behaved and stable. The mass-radius limit and the surface red shift are consistent with observational constraints. (orig.)
Galileon radiation from a spherical collapsing shell
Energy Technology Data Exchange (ETDEWEB)
Martín-García, Javier [Instituto de Física Teórica UAM/CSIC,C/ Nicolás Cabrera 15, E-28049 Madrid (Spain); Vázquez-Mozo, Miguel Á. [Instituto Universitario de Física Fundamental y Matemáticas (IUFFyM),Universidad de Salamanca, Plaza de la Merced s/n, E-37008 Salamanca (Spain)
2017-01-17
Galileon radiation in the collapse of a thin spherical shell of matter is analyzed. In the framework of a cubic Galileon theory, we compute the field profile produced at large distances by a short collapse, finding that the radiated field has two peaks traveling ahead of light fronts. The total energy radiated during the collapse follows a power law scaling with the shell’s physical width and results from two competing effects: a Vainshtein suppression of the emission and an enhancement due to the thinness of the shell.
Equivalent-spherical-shield neutron dose calculations
International Nuclear Information System (INIS)
Russell, G.J.; Robinson, H.
1988-01-01
Neutron doses through 162-cm-thick spherical shields were calculated to be 1090 and 448 mrem/h for regular and magnetite concrete, respectively. These results bracket the measured data, for reinforced regular concrete, of /approximately/600 mrem/h. The calculated fraction of the high-energy (>20 MeV) dose component also bracketed the experimental data. The measured and calculated doses were for a graphite beam stop bombarded with 100 nA of 800-MeV protons. 6 refs., 2 figs., 1 tab
Spherical Panoramas for Astrophysical Data Visualization
Kent, Brian R.
2017-05-01
Data immersion has advantages in astrophysical visualization. Complex multi-dimensional data and phase spaces can be explored in a seamless and interactive viewing environment. Putting the user in the data is a first step toward immersive data analysis. We present a technique for creating 360° spherical panoramas with astrophysical data. The three-dimensional software package Blender and the Google Spatial Media module are used together to immerse users in data exploration. Several examples employing these methods exhibit how the technique works using different types of astronomical data.
Geometrodynamics of spherically symmetric Lovelock gravity
International Nuclear Information System (INIS)
Kunstatter, Gabor; Taves, Tim; Maeda, Hideki
2012-01-01
We derive the Hamiltonian for spherically symmetric Lovelock gravity using the geometrodynamics approach pioneered by Kuchar (1994 Phys. Rev. D 50 3961) in the context of four-dimensional general relativity. When written in terms of the areal radius, the generalized Misner-Sharp mass and their conjugate momenta, the generic Lovelock action and Hamiltonian take on precisely the same simple forms as in general relativity. This result supports the interpretation of Lovelock gravity as the natural higher dimensional extension of general relativity. It also provides an important first step towards the study of the quantum mechanics, Hamiltonian thermodynamics and formation of generic Lovelock black holes. (fast track communication)
Kiani, M.; Abdolali, A.; Safari, M.
2018-03-01
In this article, an analytical approach is presented for the analysis of electromagnetic (EM) scattering from radially inhomogeneous spherical structures (RISSs) based on the duality principle. According to the spherical symmetry, similar angular dependencies in all the regions are considered using spherical harmonics. To extract the radial dependency, the system of differential equations of wave propagation toward the inhomogeneity direction is equated with the dual planar ones. A general duality between electromagnetic fields and parameters and scattering parameters of the two structures is introduced. The validity of the proposed approach is verified through a comprehensive example. The presented approach substitutes a complicated problem in spherical coordinate to an easy, well posed, and previously solved problem in planar geometry. This approach is valid for all continuously varying inhomogeneity profiles. One of the major advantages of the proposed method is the capability of studying two general and applicable types of RISSs. As an interesting application, a class of lens antenna based on the physical concept of the gradient refractive index material is introduced. The approach is used to analyze the EM scattering from the structure and validate strong performance of the lens.
Indian Academy of Sciences (India)
user1
Astr. (2012) 33, 419–420. Author Index. 419. AGGARWAL SUNNY. Photoionization Cross-Section of Chlorine-like Iron, 291. AMBASTHA ASHOK see Das, A. C., 1. ARAKIDA HIDEYOSHI. Effect of Inhomogeneity of the Universe on a Gravitationally. Bound Local System: A No-Go Result for Explaining the Secular Increase in.
Indian Academy of Sciences (India)
automorphic solutions to fractional order abstract integro-differential equations. 323. Afrouzi G A see Ala Samira ... 521. Agarwal Praveen. Certain fractional integral operators and the generalized multi-index Mittag- ... of positive solutions for sys- tems of second order multi-point bound- ary value problems on time scales 353.
African Journals Online (AJOL)
Items 101 - 150 of 1250 ... Vol 10, No 6 (2013), A study on the anticancer activity of ethanol extract of ... S Han, X Lv, Y Wang, H Gong, C Zhang, A Tong, N Yan ... YJ Wanga, Y Zhenga, GF Zhang, JP Zhanga, CX Wua, SQ Zhang, HL Ouyang, ...
Characteristic wave velocities in spherical electromagnetic cloaks
International Nuclear Information System (INIS)
Yaghjian, A D; Maci, S; Martini, E
2009-01-01
We investigate the characteristic wave velocities in spherical electromagnetic cloaks, namely, phase, ray, group and energy-transport velocities. After deriving explicit expressions for the phase and ray velocities (the latter defined as the phase velocity along the direction of the Poynting vector), special attention is given to the determination of group and energy-transport velocities, because a cursory application of conventional formulae for local group and energy-transport velocities can lead to a discrepancy between these velocities if the permittivity and permeability dyadics are not equal over a frequency range about the center frequency. In contrast, a general theorem can be proven from Maxwell's equations that the local group and energy-transport velocities are equal in linear, lossless, frequency dispersive, source-free bianisotropic material. This apparent paradox is explained by showing that the local fields of the spherical cloak uncouple into an E wave and an H wave, each with its own group and energy-transport velocities, and that the group and energy-transport velocities of either the E wave or the H wave are equal and thus satisfy the general theorem.
Initial assessments of ignition spherical torus
International Nuclear Information System (INIS)
Peng, Y.K.M.; Borowski, S.K.; Bussell, G.T.
1985-12-01
Initial assessments of ignition spherical tori suggest that they can be highly cost effective and exceptionally small in unit size. Assuming advanced methods of current drive to ramp up the plasma current (e.g., via lower hybrid wave at modest plasma densities and temperatures), the inductive solenoid can largely be eliminated. Given the uncertainties in plasma energy confinement times and the effects of strong paramagnetism on plasma pressure, and allowing for the possible use of high-strength copper alloys (e.g., C-17510, Cu-Ni-Be alloy), ignition spherical tori with a 50-s burn are estimated to have major radii ranging from 1.0 to 1.6 m, aspect ratios from 1.4 to 1.7, vacuum toroidal fields from 2 to 3 T, plasma currents from 10 to 19 MA, and fusion power from 50 to 300 MW. Because of its modest field strength and simple poloidal field coil configuration, only conventional engineering approaches are needed in the design. A free-standing toroidal field coil/vacuum vessel structure is assessed to be feasible and relatively independent of the shield structure and the poloidal field coils. This exceptionally simple configuration depends significantly, however, on practical fabrication approaches of the center conductor post, about which there is presently little experience. 19 refs
Saltation of non-spherical sand particles.
Directory of Open Access Journals (Sweden)
Zhengshi Wang
Full Text Available Saltation is an important geological process and the primary source of atmospheric mineral dust aerosols. Unfortunately, no studies to date have been able to precisely reproduce the saltation process because of the simplified theoretical models used. For example, sand particles in most of the existing wind sand movement models are considered to be spherical, the effects of the sand shape on the structure of the wind sand flow are rarely studied, and the effect of mid-air collision is usually neglected. In fact, sand grains are rarely round in natural environments. In this paper, we first analyzed the drag coefficients, drag forces, and starting friction wind speeds of sand grains with different shapes in the saltation process, then established a sand saltation model that considers the coupling effect between wind and the sand grains, the effect of the mid-air collision of sand grains, and the effect of the sand grain shape. Based on this model, the saltation process and sand transport rate of non-spherical sand particles were simulated. The results show that the sand shape has a significant impact on the saltation process; for the same wind speed, the sand transport rates varied for different shapes of sand grains by as much as several-fold. Therefore, sand shape is one of the important factors affecting wind-sand movement.
Spherical aggregates composed of gold nanoparticles
International Nuclear Information System (INIS)
Chen, C-C; Kuo, P-L; Cheng, Y-C
2009-01-01
Alkylated triethylenetetramine (C12E3) was synthesized and used as both a reductant in the preparation of gold nanoparticles by the reduction of HAuCl 4 and a stabilizer in the subsequent self-assembly of the gold nanoparticles. In acidic aqueous solution, spherical aggregates (with a diameter of about 202 ± 22 nm) of gold nanoparticles (with the mean diameter of ∼18.7 nm) were formed. The anion-induced ammonium adsorption of the alkylated amines on the gold nanoparticles was considered to provide the electrostatic repulsion and steric hindrance between the gold nanoparticles, which constituted the barrier that prevented the individual particles from coagulating. However, as the amino groups became deprotonated with increasing pH, the ammonium adsorption was weakened, and the amino groups were desorbed from the gold surface, resulting in discrete gold particles. The results indicate that the morphology of the reduced gold nanoparticles is controllable through pH-'tunable' aggregation under the mediation of the amino groups of alkylated amine to create spherical microstructures.
Status of National Spherical Torus Experiment (NSTX)*
Ono, Masayuki
2001-10-01
The main aim of National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the innovative spherical torus (ST) concept. The NSTX experimental facility has been operating reliably and its capabilities steadily improving. Due to relatively efficient ohmic current drive and benign halo current behavior, the plasma current was increased to 1.4 MA, which is well above the design value of 1 MA. The plasmas at 1 MA are now routinely heated by NBI to the average toroidal beta value of 20 percent range at 3 kG with electrons and ions in the 1-2 keV range. Even with the “L-mode” edge, the energy confinement time can well exceed the so-called L-mode (and even H-mode) scaling values. As a part of ST tool development, High Harmonic Fast Wave (HHFW) heating has demonstrated efficient electron heating with the central electron temperatures reaching 3.7 keV. HHFW induced H-modes have been also observed. For CHI (Coaxial Helicity Injection) non-inductive start-up, CHI discharges of up to 300 kA of toroidal current and 300 msec duration have been produced from zero current using = 25 kA of injected current. The poster presentation will also include the near term NSTX facility upgrade plan.
Bidispersed Sphere Packing on Spherical Surfaces
Atherton, Timothy; Mascioli, Andrew; Burke, Christopher
Packing problems on spherical surfaces have a long history, originating in the classic Thompson problem of finding the ground state configuration of charges on a sphere. Such packings contain a minimal number of defects needed to accommodate the curvature; this is predictable using the Gauss-Bonnet theorem from knowledge of the topology of the surface and the local symmetry of the ordering. Famously, the packing of spherical particles on a sphere contains a 'scar' transition, where additional defects over those required by topology appear above a certain critical number of particles and self-organize into chains or scars. In this work, we study the packing of bidispersed packings on a sphere, and hence determine the interaction of bidispersity and curvature. The resultant configurations are nearly crystalline for low values of bidispersity and retain scar-like structures; these rapidly become disordered for intermediate values and approach a so-called Appollonian limit at the point where smaller particles can be entirely accommodated within the voids left by the larger particles. We connect our results with studies of bidispersed packings in the bulk and on flat surfaces from the literature on glassy systems and jamming. Supported by a Cottrell Award from the Research Corporation for Science Advancement.
Rotating field current drive in spherical plasmas
International Nuclear Information System (INIS)
Brotherton-Ratcliffe, D.; Storer, R.G.
1988-01-01
The technique of driving a steady Hall current in plasmas using a rotating magnetic field is studied both numerically and analytically in the approximation of negligible ion flow. A spherical plasma bounded by an insulating wall and immersed in a uniform magnetic field which has both a rotating component (for current drive) and a constant ''vertical'' component (for MHD equilibrium) is considered. The problem is formulated in terms of an expansion of field quantities in vector spherical harmonics. The numerical code SPHERE solves the resulting pseudo-harmonic equations by a multiple shooting technique. The results presented, in addition to being relevant to non-inductive current drive generally, have a direct relevance to the rotamak experiments. For the case of no applied vertical field the steady state toroidal current driven by the rotating field per unit volume of plasma is several times less than in the long cylinder limit for a plasma of the same density, resistivity and radius. The application of a vertical field, which for certain parameter regimes gives rise to a compact torus configuration, improves the current drive dramatically and in many cases gives ''better'' current drive than the long cylinder limit. This result is also predicted by a second order perturbation analysis of the pseudo-harmonic equations. A steady state toroidal field is observed which appears consistent with experimental observations in rotamaks regarding magnitude and spatial dependence. This is an advance over previous analytical theory which predicted an oppositely directed toroidal field of undefined magnitude. (author)
Crack propagation on spherical pressure vessels
International Nuclear Information System (INIS)
Lebey, J.; Roche, R.
1975-01-01
The risk presented by a crack on a pressure vessel built with a ductile steel cannot be well evaluated by simple application of the rules of Linear Elastic Fracture Mechanics, which only apply to brittle materials. Tests were carried out on spherical vessels of three different scales built with the same steel. Cracks of different length were machined through the vessel wall. From the results obtained, crack initiation stress (beginning of stable propagation) and instable propagation stress may be plotted against the lengths of these cracks. For small and medium size, subject to ductile fracture, the resulting curves are identical, and may be used for ductile fracture prediction. Brittle rupture was observed on larger vessels and crack propagation occurred at lower stress level. Preceedings curves are not usable for fracture analysis. Ultimate pressure can be computed with a good accuracy by using equivalent energy toughness, Ksub(1cd), characteristic of the metal plates. Satisfactory measurements have been obtained on thin samples. The risks of brittle fracture may then judged by comparing Ksub(1cd) with the calculated K 1 value, in which corrections for vessel shape are taken into account. It is thus possible to establish the bursting pressure of cracked spherical vessels, with the help of two rules, one for brittle fracture, the other for ductile instability. A practical method is proposed on the basis of the work reported here
Mochizuki, Hiroyuki; Takahashi, Masashi; Nishigaki, Kazuo; Ide, Tetsuya; Goto-Koshino, Yuko; Watanabe, Shinya; Sato, Hirofumi; Sato, Masahiko; Kotera, Yukiko; Fujino, Yasuhito; Ohno, Koichi; Uchida, Kazuyuki; Tsujimoto, Hajime
2011-04-15
We established a novel feline B-cell line, MS4, from the neoplastic pleural effusion of a cat with cutaneous B-cell lymphoma. Immunophenotype staining of the MS4 cells was positive for CD20, CD79α, and IgA and negative for CD3, CD4, CD5, CD8α, CD18, CD21, CD22, IgM, IgG, Ig light chain, and MHC class II. PCR analysis for immunoglobulin heavy chain gene rearrangements revealed a monoclonal rearrangement, whereas no clonal rearrangement of the T-cell receptor γ gene was detected. Southern blotting with an exogenous feline leukemia virus (FeLV) U3 probe revealed no integration of exogenous FeLV provirus. The MS4 cell line is the first FeLV-negative feline B-cell lymphoma cell line, and may be used to investigate the pathogenesis of spontaneously occurring feline lymphoma and the development of new therapies. Copyright © 2011 Elsevier B.V. All rights reserved.
DEFF Research Database (Denmark)
Linnet, Poul Martin
2007-01-01
basis. The data are divided into different indicators such as security, polls, drug, social, economic, refugees etc. This represents a practical division and does not indicate that a picture as to for instance security can be obtained by solely looking at the data under security. In order to obtain...... a more valid picture on security this must incorporate an integrated look on all data meaning that for instance the economic data provides an element as to the whole picture of security.......The Afghanistan index is a compilation of quantitative and qualitative data on the reconstruction and security effort in Afghanistan. The index aims at providing data for benchmarking of the international performance and thus provides the reader with a quick possibility to retrieve valid...
Wang, Haoyu; Sun, Yingxian; Li, Zhao; Guo, Xiaofan; Chen, Shuang; Ye, Ning; Tian, Yichen; Zhang, Lijun
2018-04-10
Despite current interest in the unfavorable impact of cardiometabolic index (CMI) and lipid accumulation product (LAP) on diabetes and cardiovascular risk, information regarding the relation of CMI and LAP to left ventricular (LV) geometry has not been specifically addressed. We aimed to examine the hypothesis: (1) CMI and LAP represent an independent determinant of LV remodeling in general population of rural China; (2) there are gender differences in obesity-related alterations in terms of LV morphology. The sample for this cross-sectional analysis included 11,258 participants (mean age 53.9 years; 54.0% females) who underwent assessment of basic metabolic and anthropometric parameters in rural areas of northeast China. Comprehensive echocardiography-defined LV geometric pattern was determined according to left ventricular mass index and relative wall thickness. The prevalence rate of eccentric and concentric LV hypertrophy (LVH) presented a proportional increase with elevated quartiles of CMI and LAP in a dose-response manner (all P factor of 3.552 and 1.768 in females and males, respectively. In contrast to females, where LAP fourth quartile and concentric LVH were positively associated (OR:2.544, 95%CI:1.537-4.209), higher LAP did not correlate with concentric LVH in males (OR:1.234, 95%CI:0.824-1.849). CMI and LAP give rise to a new paradigm of accounting for gender difference in obesity-related abnormal LV geometry, an effect that was substantially greater in females. These two indices, acting in concert, may also be advantageous prognostically for refining cardiovascular risk stratification in individuals with LV remodeling.
Measurement of Turbulence Modulation by Non-Spherical Particles
DEFF Research Database (Denmark)
Mandø, Matthias; Rosendahl, Lasse
2010-01-01
The change in the turbulence intensity of an air jet resulting from the addition of particles to the flow is measured using Laser Doppler Anemometry. Three distinct shapes are considered: the prolate spheroid, the disk and the sphere. Measurements of the carrier phase and particle phase velocities...... at the centerline of the jet are carried out for mass loadings of 0.5, 1, 1.6 and particle sizes 880μm, 1350μm, 1820μm for spherical particles. For each non-spherical shape only a single size and loading are considered. The turbulence modulation of the carrier phase is found to highly dependent on the turbulence......, the particle mass flow and the integral length scale of the flow. The expression developed on basis of spherical particles only is applied on the data for the non-spherical particles. The results suggest that non-spherical particles attenuate the carrier phase turbulence significantly more than spherical...
The prediction of spherical aberration with schematic eyes.
Liou, H L; Brennan, N A
1996-07-01
Many model eyes have been proposed; they differ in optical characteristics and therefore have different aberrations and image quality. In predicting the visual performance of the eye, we are most concerned with the central foveal vision. Spherical aberration is the only on-axis monochromatic aberration and can be used as a criterion to assess the degree of resemblance of eye models to the human eye. We reviewed and compiled experimental values of the spherical aberration of the eye, calculated the spherical aberration of several different categories of model eyes and compared the calculated results to the experimental data. Results show an over-estimation of spherical aberration by all models, the finite schematic eyes predicting values of spherical aberration closest to the experimental data. Current model eyes do not predict the average experimental values of the spherical aberration of the eye. A new model eye satisfying this assessment criterion is required for investigations of the visual performance of the eye.
Non-Spherical Gravitational Collapse of Strange Quark Matter
Institute of Scientific and Technical Information of China (English)
Zade S S; Patil K D; Mulkalwar P N
2008-01-01
We study the non-spherical gravitational collapse of the strange quark null fluid.The interesting feature which emerges is that the non-spherical collapse of charged strange quark matter leads to a naked singularity whereas the gravitational collapse of neutral quark matter proceeds to form a black hole.We extend the earlier work of Harko and Cheng[Phys.Lett.A 266 (2000) 249]to the non-spherical case.
Spherical solitons in Earth’S mesosphere plasma
International Nuclear Information System (INIS)
Annou, K.; Annou, R.
2016-01-01
Soliton formation in Earth’s mesosphere plasma is described. Nonlinear acoustic waves in plasmas with two-temperature ions and a variable dust charge where transverse perturbation is dealt with are studied in bounded spherical geometry. Using the perturbation method, a spherical Kadomtsev–Petviashvili equation that describes dust acoustic waves is derived. It is found that the parameters taken into account have significant effects on the properties of nonlinear waves in spherical geometry
On the phase diagram of non-spherical nanoparticles
Wautelet, M; Hecq, M
2003-01-01
The phase diagram of nanoparticles is known to be a function of their size. In the literature, this is generally demonstrated for cases where their shape is spherical. Here, it is shown theoretically that the phase diagram of non-spherical particles may be calculated from the spherical case, at the same surface area/volume ratio, both with and without surface segregation, provided the surface tension is considered to be isotropic.
Directory of Open Access Journals (Sweden)
Onishi Tetsuari
2011-04-01
Full Text Available Abstract Background We have previously reported strain dyssynchrony index assessed by two-dimensional speckle tracking strain, and a marker of both dyssynchrony and residual myocardial contractility, can predict response to cardiac resynchronization therapy (CRT. A newly developed three-dimensional (3-D speckle tracking system can quantify endocardial area change ratio (area strain, which coupled with the factors of both longitudinal and circumferential strain, from all 16 standard left ventricular (LV segments using complete 3-D pyramidal datasets. Our objective was to test the hypothesis that strain dyssynchrony index using area tracking (ASDI can quantify dyssynchrony and predict response to CRT. Methods We studied 14 heart failure patients with ejection fraction of 27 ± 7% (all≤35% and QRS duration of 172 ± 30 ms (all≥120 ms who underwent CRT. Echocardiography was performed before and 6-month after CRT. ASDI was calculated as the average difference between peak and end-systolic area strain of LV endocardium obtained from 3-D speckle tracking imaging using 16 segments. Conventional dyssynchrony measures were assessed by interventricular mechanical delay, Yu Index, and two-dimensional radial dyssynchrony by speckle-tracking strain. Response was defined as a ≥15% decrease in LV end-systolic volume 6-month after CRT. Results ASDI ≥ 3.8% was the best predictor of response to CRT with a sensitivity of 78%, specificity of 100% and area under the curve (AUC of 0.93 (p Conclusions ASDI can predict responders and LV reverse remodeling following CRT. This novel index using the 3-D speckle tracking system, which shows circumferential and longitudinal LV dyssynchrony and residual endocardial contractility, may thus have clinical significance for CRT patients.
On three-dimensional spherical acoustic cloaking
International Nuclear Information System (INIS)
Munteanu, Ligia; Chiroiu, Veturia
2011-01-01
Transformation acoustics opens a new avenue towards the design of acoustic metamaterials, which are materials engineered at the subwavelength scale in order to mimic the parameters in wave equations. The design of the acoustic cloaking is based on the property of equations being invariant under a coordinate transformation, i.e. a specific spatial compression is equivalent to a variation of the material parameters in the original space. In this paper, the sound invisibility performance is discussed for spherical cloaks. The original domain consists of alternating concentric layers made from piezoelectric ceramics and epoxy resin, following a triadic Cantor sequence. The spatial compression, obtained by applying the concave-down transformation, leads to an equivalent domain with an inhomogeneous and anisotropic distribution of the material parameters.
Nuclear structure investigations on spherical nuclei
International Nuclear Information System (INIS)
Heisenberg, J.; Calarco, J.; Dawson, J.; Hersman, F.W.
1989-09-01
This report discusses the following topics: electron scattering studies on spherical nuclei; electron scattering from collective states in deformed nuclei; proton and pion scattering studies; 12 C(e,e'p) and 16 O(e,e'p); 12 C(e,e'α) and 16 O(e,e'α); studies at high q at Bates; measurements with rvec e at Bates; 12 C(γ,p); future directions in giant resonance studies; proton knockout from 16 O; quasielastic studies at Bates; triple coincidence studies of nuclear correlations; contributions to (e,e'2p) at KIKHEF; contributions to instrumentation at CEBAF; instrumentation development at UNH; the Bates large acceptance spectrometer toroid; shell model and core polarization calculations; and the relativistic nuclear model
Saltation movement of large spherical particles
Chara, Z.; Dolansky, J.; Kysela, B.
2017-07-01
The paper presents experimental and numerical investigations of the saltation motion of a large spherical particle in an open channel. The channel bottom was roughed by one layer of glass rods of diameter 6 mm. The plastic spheres of diameter 25.7 mm and density 1160 kgm-3 were fed into the water channel and theirs positions were viewed by a digital camera. Two light sheets were placed above and under the channel, so the flow was simultaneously lighted from the top and the bottom. Only particles centers of which moved through the light sheets were recorded. Using a 2D PIV method the trajectories of the spheres and the velocity maps of the channel flow were analyzed. The Lattice-Boldzmann Method (LBM) was used to simulate the particle motion.
Coulomb potentials between spherical heavy ions
International Nuclear Information System (INIS)
Iwe, H.
1982-01-01
The Coulomb interaction between spherical nuclei having arbitrary radial nuclear charge distributions is calculated. All these realistic Coulomb potentials are given in terms of analytical expressions and are available for immediate application. So in no case a numerical computation of the Coulomb integral is required. The parameters of the charge distributions are taken from electron scattering analysis. The Coulomb self-energies of the charge distributions used are also calculated analytically in a closed form. For a number of nucleus-nucleus pairs, the Coulomb potentials derived from realistic charge distributions are compared with those normally used in various nucleus-nucleus optical model calculations. In this connection a detailed discussion of the problem how to choose consistently Coulomb parameters for different approximations is given. (orig.)
Application studies of spherical tokamak plasma merging
International Nuclear Information System (INIS)
Ono, Yasushi; Inomoto, Michiaki
2012-01-01
The experiment of plasma merging and heating has long history in compact torus studies since Wells. The study of spherical tokamak (ST), starting from TS-3 plasma merging experiment of Tokyo University in the late 1980s, is followed by START of Culham laboratory in the 1900s, TS-4 and UTST of Tokyo University and MAST of Culham laboratory in the 2000s, and last year by VEST of Soul University. ST has the following advantages: 1) plasma heating by magnetic reconnection at a MW-GW level, 2) rapid start-up of high beta plasma, 3) current drive/flux multiplication and distribution control of ST plasma, 4) fueling and helium-ash exhaust. In the present article, we emphasize that magnetic reconnection and plasma merging phenomena are important in ST plasma study as well as in plasma physics. (author)
Confined detonations with cylindrical and spherical symmetry
International Nuclear Information System (INIS)
Linan, A.; Lecuona, A.
1979-01-01
An imploding spherical or cylindrical detonation, starting in the interface of the detonantion with an external inert media, used as a reflector, creates on it a strong shock wave moving outward from the interface. An initially weak shock wave appears in the detonated media that travels toward the center, and it could reach the detonation wave, enforcing it in its process of implosion. To describe the fluid field, the Euler s equations are solved by means of expansions valid for the early stages of the process. Isentropic of the type P/pγ-K for the detonated and compressed inert media are used. For liquid or solid reflectors a more appropriate equation is used. (Author) 8 refs
Simple spherical ablative-implosion model
International Nuclear Information System (INIS)
Mayer, F.J.; Steele, J.T.; Larsen, J.T.
1980-01-01
A simple model of the ablative implosion of a high-aspect-ratio (shell radius to shell thickness ratio) spherical shell is described. The model is similar in spirit to Rosenbluth's snowplow model. The scaling of the implosion time was determined in terms of the ablation pressure and the shell parameters such as diameter, wall thickness, and shell density, and compared these to complete hydrodynamic code calculations. The energy transfer efficiency from ablation pressure to shell implosion kinetic energy was examined and found to be very efficient. It may be possible to attach a simple heat-transport calculation to our implosion model to describe the laser-driven ablation-implosion process. The model may be useful for determining other energy driven (e.g., ion beam) implosion scaling
Space Propulsion via Spherical Torus Fusion Reactor
International Nuclear Information System (INIS)
Williams, Craig H.; Juhasz, Albert J.; Borowski, Stanley K.; Dudzinski, Leonard A.
2003-01-01
A conceptual vehicle design enabling fast outer solar system travel was produced predicated on a small aspect ratio spherical torus nuclear fusion reactor. Analysis revealed that the vehicle could deliver a 108 mt crew habitat payload to Saturn rendezvous in 204 days, with an initial mass in low Earth orbit of 1630 mt. Engineering conceptual design, analysis, and assessment were performed on all major systems including nuclear fusion reactor, magnetic nozzle, power conversion, fast wave plasma heating, fuel pellet injector, startup/re-start fission reactor and battery, and other systems. Detailed fusion reactor design included analysis of plasma characteristics, power balance and utilization, first wall, toroidal field coils, heat transfer, and neutron/X-ray radiation
Canonical quantization of static spherically symmetric geometries
International Nuclear Information System (INIS)
Christodoulakis, T; Dimakis, N; Terzis, P A; Doulis, G; Grammenos, Th; Melas, E; Spanou, A
2013-01-01
The conditional symmetries of the reduced Einstein–Hilbert action emerging from a static, spherically symmetric geometry are used as supplementary conditions on the wave function. Based on their integrability conditions, only one of the three existing symmetries can be consistently imposed, while the unique Casimir invariant, being the product of the remaining two symmetries, is calculated as the only possible second condition on the wave function. This quadratic integral of motion is identified with the reparametrization generator, as an implication of the uniqueness of the dynamical evolution, by fixing a suitable parametrization of the r-lapse function. In this parametrization, the determinant of the supermetric plays the role of the mesure. The combined Wheeler – DeWitt and linear conditional symmetry equations are analytically solved. The solutions obtained depend on the product of the two ''scale factors''
Laser Pulse Heating of Spherical Metal Particles
Directory of Open Access Journals (Sweden)
Michael I. Tribelsky
2011-12-01
Full Text Available We consider the general problem of laser pulse heating of spherical metal particles with the sizes ranging from nanometers to millimeters. We employ the exact Mie solution of the diffraction problem and solve the heat-transfer equation to determine the maximum temperature rise at the particle surface as a function of optical and thermometric parameters of the problem. Primary attention is paid to the case when the thermal diffusivity of the particle is much larger than that of the environment, as it is in the case of metal particles in fluids. We show that, in this case, for any given duration of the laser pulse, the maximum temperature rise as a function of the particle size reaches a maximum at a certain finite size of the particle. We suggest simple approximate analytical expressions for this dependence, which cover the entire parameter range of the problem and agree well with direct numerical simulations.
Spherical Nb single crystals containerlessly grown by electrostatic levitation
International Nuclear Information System (INIS)
Sung, Y.S.; Takeya, H.; Hirata, K.; Togano, K.
2003-01-01
Spherical Nb (T m =2750 K) single crystals were grown via containerless electrostatic levitation (ESL). Samples became spherical at melting in levitation and undercooled typically 300-450 K prior to nucleation. As-processed samples were still spherical without any macroscopic shape change by solidification showing a uniform dendritic surface morphology. Crystallographic {111} planes exposed in equilateral triangular shapes on the surface by preferential macroetching and spotty back-reflection Laue patterns confirm the single crystal nature of the ESL-processed Nb samples. No hysteresis in magnetization between zero field and field cooling also implies a clean defect-free condition of the spherical Nb single crystals
Investigation of spherical and concentric mechanism of compound droplets
Directory of Open Access Journals (Sweden)
Meifang Liu
2016-07-01
Full Text Available Polymer shells with high sphericity and uniform wall thickness are always needed in the inertial confined fusion (ICF experiments. Driven by the need to control the shape of water-in-oil (W1/O compound droplets, the effects of the density matching level, the interfacial tension and the rotation speed of the continuing fluid field on the sphericity and wall thickness uniformity of the resulting polymer shells were investigated and the spherical and concentric mechanisms were also discussed. The centering of W1/O compound droplets, the location and movement of W1/O compound droplets in the external phase (W2 were significantly affected by the density matching level of the key stage and the rotation speed of the continuing fluid field. Therefore, by optimizing the density matching level and rotation speed, the batch yield of polystyrene (PS shells with high sphericity and uniform wall thickness increased. Moreover, the sphericity also increased by raising the oil/water (O/W2 interfacial tension, which drove a droplet to be spherical. The experimental results show that the spherical driving force is from the interfacial tension affected by the two relative phases, while the concentric driving force, as a resultant force, is not only affected by the three phases, but also by the continuing fluid field. The understanding of spherical and concentric mechanism can provide some guidance for preparing polymer shells with high sphericity and uniform wall thickness.
Low-Q Electrically Small Spherical Magnetic Dipole Antennas
DEFF Research Database (Denmark)
Kim, Oleksiy S.
2010-01-01
Three novel electrically small antenna configurations radiating a TE10 spherical mode corresponding to a magnetic dipole are presented and investigated: multiarm spherical helix (MSH) antenna, spherical split ring resonator (S-SRR) antenna, and spherical split ring (SSR) antenna. All three antennas...... are self-resonant, with the input resistance tuned to 50 ohms by an excitation curved dipole/monopole. A prototype of the SSR antenna has been fabricated and measured, yielding results that are consistent with the numerical simulations. Radiation quality factors (Q) of these electrically small antennas (in...
Fluid Fuel Fluctuations in the Spherical Tank
Directory of Open Access Journals (Sweden)
H. D. Nguyen
2014-01-01
Full Text Available Many authors tried to solve a task concerning small fluctuations of the incompressible ideal liquid, which partially fills a stationary tank of any shape. There is a long list of references to this subject. The article presents a task solution on own fluctuations of liquid in spherical capacity, with boundary conditions on a free surface and a surface with a resistance – drain surface. Relevance of problem consists in assessment of influence of intra tank devices (measuring, intaking, damping devices, etc. on the liquid fuel fluctuations. The special attention is paid to finding the own values and frequencies of the equations of disturbed flow fluctuations with dissipation available on the boundary surfaces. In contrast to the previous examples, the lowering speed and the free surface area at undisturbed state are variable.The article also considers a variation formulation of the auxiliary boundary tasks. In solution of variation tasks, the attached Legendre's functions were used as coordinate functions. Further, after substitution of the variation tasks solution in the boundary conditions and the subsequent mathematical operations the characteristic equation was obtained. To obtain solutions of the cubic characteristic equation Cardano formulas were used. The article also considers the task on the own motions of liquid filling a capacity between two concentric spheres and flowing out via the intake in case there is a free surface. Reliability of the obtained numerical results is confirmed by comparison with calculation results of frequencies resulting from solutions of a task on the own fluctuations of liquid in the spherical capacity with the constant depth of liquid. All numerical calculations were performed using the Matlab environment.
Directory of Open Access Journals (Sweden)
Yan Chen
2017-06-01
Full Text Available AIM: To evaluate the impact of spherical and aspherical intraocular lenses on the postoperative visual quality of age-related cataract patients using Optical Quality Analysis System (OQAS. METHODS: Seventy-four eyes with age-related cataracts were randomly divided into spherical and aspherical lens implantation groups. Best-corrected visual acuity (BCVA was measured preoperatively, one day, one week, two weeks, one month and two months after surgery. A biometric systems analysis using the OQAS objective scattering index (OSI was performed. RESULTS: There were no significant differences in visual acuity (P>0.05 before and after spherical and aspheric lens implantation. There was a negative linear correction between the OSI value and BCVA (r=-0.634, P=0.000, and positive corrections between the OSI value and the lens LOCUS III value of nucleus color (NC, nucleus opacity (NO, cortex (C and posterior lens capsular (P (r=0.704, P=0.000; r=0.514, P=0.000; r=0.276, P=0.020; r=0.417, P=0.000, respectively. OSI values of spherical vs aspherical lenses were 11.5±3.6 vs 11.8±3.4, 4.1±0.9 vs 3.3±0.8, 3.5±0.9 vs 2.7±0.7, 3.3±0.8 vs 2.6±0.7, 3.2±0.7 vs 2.5±0.8, and 3.2±0.8 vs 2.5±0.8 before and 1d, 1, 2wk, 1 and 2mo after surgery, respectively. All time points varied significantly (P<0.01 between the two groups. CONCLUSION: Aspherical IOLs does not significantly affect visual acuity compared with spherical IOLs. The OSI value, was significantly lower in the aspherical lens group compared with the spherical lens. This study shows that objective visual quality of aspheric IOLs is better than that of the spherical lens by means of OQAS biological measurement method.
Lim, Sooyeon; Rhee, Moon-Soo; Chang, Dong-Ho; Kim, Byoung-Chan
2016-04-10
Erysipelothrix larvae LV19(T) was preliminary isolated from the larval gut of a rhinoceros beetle, Trypoxylus dichotomus in Korea. Here, we present the whole genome sequence of E. larvae LV19(T) strain, which consisted of 2,511,486 base pairs with a GC content of 37.4% and one plasmid. Unlike other Erysipelothrix strains (SY 1027, Fujisawa and ATCC 19414), the arsenic-resistance genes were identified in LV19(T) strain. Copyright © 2016 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Sahni, D.C.; Sharma, A.
2000-01-01
The integral form of one-speed, spherically symmetric neutron transport equation with isotropic scattering is considered. Two standard problems are solved using normal mode expansion technique. The expansion coefficients are obtained by solving their singular integral equations. It is shown that these expansion coefficients provide a representation of all spherical harmonics moments of the angular flux as a superposition of Bessel functions. It is seen that large errors occur in the computation of higher moments unless we take certain precautions. The reasons for this phenomenon are explained. They throw some light on the failure of spherical harmonics method in treating spherical geometry problems as observed by Aronsson
Initial value formulation for the spherically symmetric dust solution
International Nuclear Information System (INIS)
Liu, H.
1990-01-01
An initial value formulation for the dust solution with spherical symmetry is given explicitly in which the initial distributions of dust and its velocity on an initial surface are chosen to be the initial data. As special cases, the Friedmann universe, the Schwarzschild solution in comoving coordinates, and a spherically symmetric and radially inhomogeneous cosmological model are derived
Cylindrical and spherical dust-acoustic wave modulations in dusty ...
Indian Academy of Sciences (India)
Abstract. The nonlinear wave modulation of planar and non-planar (cylindrical and spherical) dust-acoustic waves (DAW) propagating in dusty plasmas, in the presence of non-extensive distribu- tions for ions and electrons is investigated. By employing multiple scales technique, a cylindrically and spherically modified ...
Systematic Calibration for a Backpacked Spherical Photogrammetry Imaging System
Rau, J. Y.; Su, B. W.; Hsiao, K. W.; Jhan, J. P.
2016-06-01
A spherical camera can observe the environment for almost 720 degrees' field of view in one shoot, which is useful for augmented reality, environment documentation, or mobile mapping applications. This paper aims to develop a spherical photogrammetry imaging system for the purpose of 3D measurement through a backpacked mobile mapping system (MMS). The used equipment contains a Ladybug-5 spherical camera, a tactical grade positioning and orientation system (POS), i.e. SPAN-CPT, and an odometer, etc. This research aims to directly apply photogrammetric space intersection technique for 3D mapping from a spherical image stereo-pair. For this purpose, several systematic calibration procedures are required, including lens distortion calibration, relative orientation calibration, boresight calibration for direct georeferencing, and spherical image calibration. The lens distortion is serious on the ladybug-5 camera's original 6 images. Meanwhile, for spherical image mosaicking from these original 6 images, we propose the use of their relative orientation and correct their lens distortion at the same time. However, the constructed spherical image still contains systematic error, which will reduce the 3D measurement accuracy. Later for direct georeferencing purpose, we need to establish a ground control field for boresight/lever-arm calibration. Then, we can apply the calibrated parameters to obtain the exterior orientation parameters (EOPs) of all spherical images. In the end, the 3D positioning accuracy after space intersection will be evaluated, including EOPs obtained by structure from motion method.
Stability of transparent spherically symmetric thin shells and wormholes
International Nuclear Information System (INIS)
Ishak, Mustapha; Lake, Kayll
2002-01-01
The stability of transparent spherically symmetric thin shells (and wormholes) to linearized spherically symmetric perturbations about static equilibrium is examined. This work generalizes and systematizes previous studies and explores the consequences of including the cosmological constant. The approach shows how the existence (or not) of a domain wall dominates the landscape of possible equilibrium configurations
Invariants of the spherical sector in conformal mechanics
International Nuclear Information System (INIS)
Hakobyan, Tigran; Nersessian, Armen; Saghatelian, Armen; Lechtenfeld, Olaf
2011-01-01
A direct relation is established between the constants of motion for conformal mechanics and those for its spherical part. In this way, we find the complete set of functionally independent constants of motion for the so-called cuboctahedric Higgs oscillator, which is just the spherical part of the rational A 3 Calogero model (describing four Calogero particles after decoupling their center of mass).
Rapid Prototyping of Electrically Small Spherical Wire Antennas
DEFF Research Database (Denmark)
Kim, Oleksiy S.
2014-01-01
It is shown how modern rapid prototyping technologies can be applied for quick and inexpensive, but still accurate, fabrication of electrically small wire antennas. A well known folded spherical helix antenna and a novel spherical zigzag antenna have been fabricated and tested, exhibiting...
Effect of the spherical Earth on a simple pendulum
Burko, Lior M.
2003-01-01
We consider the period of a simple pendulum in the gravitational field of the spherical Earth. Effectively, gravity is enhanced compared with the often used flat Earth approximation, such that the period of the pendulum is shortened. We discuss the flat Earth approximation, and show when the corrections due to the spherical Earth may be of interest.
Sextupole system for the correction of spherical aberration
Crewe, A.V.; Kopf, D.A.
In an electron beam device in which an electron beam is developed and then focused by a lens to a particular spot, there is provided a means for eliminating spherical aberration. A sextupole electromagnetic lens is positioned between two focusing lenses. The interaction of the sextupole with the beam compensates for spherical aberration. (GHT)
Erosion and damage by hard spherical particles on glass
Slikkerveer, P.J.; Verspui, M.A.; Skerka, G.J.E.
1999-01-01
Solid particle impact of hard spherical particles on glass is of fundamental interest because of the presence of a number of different impact regimes. Understanding the impact of spherical particles is also a step toward modeling the behavior of rounded particles. This paper verifies theoretical
Equilibrium spherically curved two-dimensional Lennard-Jones systems
Voogd, J.M.; Sloot, P.M.A.; van Dantzig, R.
2005-01-01
To learn about basic aspects of nano-scale spherical molecular shells during their formation, spherically curved two-dimensional N-particle Lennard-Jones systems are simulated, studying curvature evolution paths at zero-temperature. For many N-values (N < 800) equilibrium configu- rations are traced
Theory and applications of spherical microphone array processing
Jarrett, Daniel P; Naylor, Patrick A
2017-01-01
This book presents the signal processing algorithms that have been developed to process the signals acquired by a spherical microphone array. Spherical microphone arrays can be used to capture the sound field in three dimensions and have received significant interest from researchers and audio engineers. Algorithms for spherical array processing are different to corresponding algorithms already known in the literature of linear and planar arrays because the spherical geometry can be exploited to great beneficial effect. The authors aim to advance the field of spherical array processing by helping those new to the field to study it efficiently and from a single source, as well as by offering a way for more experienced researchers and engineers to consolidate their understanding, adding either or both of breadth and depth. The level of the presentation corresponds to graduate studies at MSc and PhD level. This book begins with a presentation of some of the essential mathematical and physical theory relevant to ...
A modular spherical harmonics approach to the neutron transport equation
International Nuclear Information System (INIS)
Inanc, F.; Rohach, A.F.
1989-01-01
A modular nodal method was developed for solving the neutron transport equation in 2-D xy coordinates. The spherical harmonic expansion was used for approximating the second-order even-parity form of the neutron transport equation. The boundary conditions of the spherical harmonics approximation were derived in a form to have forms analogous to the partial currents in the neutron diffusion equation. Relations were developed for generating both the second-order spherical harmonic equations and the boundary conditions in an automated computational algorithm. Nodes using different orders of the spherical harmonics approximation to the transport equation were interfaced through mixed-type boundary conditions. The determination of spherical harmonic orders implemented in the nodes were determined by the scheme in an automated manner. Results of the method compared favorably to benchmark problems. (author)
Ju, Jia-Fei; Hoffmann, Ary A; Zhang, Yan-Kai; Duan, Xing-Zhi; Guo, Yan; Gong, Jun-Tao; Zhu, Wen-Chao; Hong, Xiao-Yue
2017-06-01
Wolbachia are endosymbionts that infect many species of arthropods and nematodes. Wolbachia-induced cytoplasmic incompatibility (CI) is the most common phenotype in affected hosts, involving embryonic lethality in crosses between Wolbachia-infected males and uninfected females. The molecular mechanisms underlying this phenomenon are currently unclear. Here we examine the molecular correlates of the Wolbachia infection in Laodelphax striatellus (Fallén), an important rice pest, where embryonic lethality is strong and almost complete. We compared the gene expression of 4-day-old Wolbachia-infected and uninfected L. striatellus testes to identify candidate genes for paternal-effect embryonic lethality induction. Based on microarray analysis, iLvE was the most down-regulated gene; this gene mediates branched-chain amino acid (BCAA) biosynthesis and participates in many processes related to reproductive performance. After knocking down iLvE by RNAi in uninfected male L. striatellus, male fertility was reduced, leading to a decrease in embryo hatching rates, but fertility was rescued in crosses between these males and Wolbachia-infected females. Removal of BCAA in chemically-defined diets of uninfected males also led to a loss of male fertility. Low amino acid nutrition may enhance exposure time of sperm to Wolbachia in the testes to affect adult reproduction in L. striatellus by reducing the number of sperm transferred per mating by males. These results indicate that Wolbachia may decrease male fertility in L. striatellus by acting on iLvE, a key factor of BCAA biosynthesis, and delaying sperm maturation. Copyright © 2017 Elsevier Ltd. All rights reserved.
Excitation of Alfvenic instabilities in spherical tokamaks
International Nuclear Information System (INIS)
McClements, K.G.; Appel, L.C.; Hole, M.J.; Thyagaraja, A.
2003-01-01
Understanding energetic particle confinement in spherical tokamak (STs) is important for optimising the design of ST power plants, and provides a testbed for theoretical modelling under conditions of strong toroidicity and shaping, and high beta. MHD analysis of some recent beam-heated discharges in the MAST ST indicates that high frequency modes observed in these discharges can be identified as toroidal Alfven Eigenmodes (TAEs) and elliptical Alfven Eigenmodes (EAEs). It is possible that such modes could strongly enhance fusion alpha-particle transport in an ST power plant. Computations of TAE growth rates for one particular MAST discharge, made using the HAGIS guiding centre code and benchmarked against analytical estimates, indicate strong drive by sub-Alfvenic neutral beam ions. HAGIS computations using higher mode amplitudes than those observed indicate that whereas co-passing beam ions provide the bulk of he TAE drive, counter-passing ions provide the dominant component of TAE-induced particle losses. Axisymmetric Alfvenic mode activity has been detected during ohmic discharges in MAST. These observations are shown by computational modelling to be consistent with the excitation of global Alfven Eigenmodes (GAEs) with n=0 and low m, driven impulsively by low frequency MHD. (author)
Plasmonic and silicon spherical nanoparticle antireflective coatings
Baryshnikova, K. V.; Petrov, M. I.; Babicheva, V. E.; Belov, P. A.
2016-03-01
Over the last decade, plasmonic antireflecting nanostructures have been extensively studied to be utilized in various optical and optoelectronic systems such as lenses, solar cells, photodetectors, and others. The growing interest to all-dielectric photonics as an alternative optical technology along with plasmonics motivates us to compare antireflective properties of plasmonic and all-dielectric nanoparticle coatings based on silver and crystalline silicon respectively. Our simulation results for spherical nanoparticles array on top of amorphous silicon show that both silicon and silver coatings demonstrate strong antireflective properties in the visible spectral range. For the first time, we show that zero reflectance from the structure with silicon coatings originates from the destructive interference of electric- and magnetic-dipole responses of nanoparticle array with the wave reflected from the substrate, and we refer to this reflection suppression as substrate-mediated Kerker effect. We theoretically compare the silicon and silver coating effectiveness for the thin-film photovoltaic applications. Silver nanoparticles can be more efficient, enabling up to 30% increase of the overall absorbance in semiconductor layer. Nevertheless, silicon coatings allow up to 64% absorbance increase in the narrow band spectral range because of the substrate-mediated Kerker effect, and band position can be effectively tuned by varying the nanoparticles sizes.
The spheric tokamak programme at Culham
International Nuclear Information System (INIS)
Sykes, A.
1999-01-01
The Spherical Tokamak (ST) is the low aspect ratio limit of the conventional tokamak, and appears to offer attractive physics properties in a simpler device. The START (Small Tight Aspect Ratio Tokamak) experiment provided the world's first demonstration of the properties of hot plasmas in an ST configuration, and was operational at Culham from January 1991 to March 1998, obtaining plasma current of up to 300 kA and pulse durations of ∼ 50 ms. Its successor, MAST is scheduled to obtain first plasma in Autumn 1998 and is a purpose built, high vacuum machine designed to have a tenfold increase in plasma volume with plasma currents up to 2 MA. Current drive and heating will be by a combination of induction-compression as on START, a high-performance central solenoid, 1.5 MW ECRH and 5 MW of Neutral Beam Injection. The promising results from START are reviewed, and the many challenges posed for the next generation of purpose-built STs (such as MAST) are described. (author)
Spherical images and inextensible curved folding
Seffen, Keith A.
2018-02-01
In their study, Duncan and Duncan [Proc. R. Soc. London A 383, 191 (1982), 10.1098/rspa.1982.0126] calculate the shape of an inextensible surface folded in two about a general curve. They find the analytical relationships between pairs of generators linked across the fold curve, the shape of the original path, and the fold angle variation along it. They present two special cases of generator layouts for which the fold angle is uniform or the folded curve remains planar, for simplifying practical folding in sheet-metal processes. We verify their special cases by a graphical treatment according to a method of Gauss. We replace the fold curve by a piecewise linear path, which connects vertices of intersecting pairs of hinge lines. Inspired by the d-cone analysis by Farmer and Calladine [Int. J. Mech. Sci. 47, 509 (2005), 10.1016/j.ijmecsci.2005.02.013], we construct the spherical images for developable folding of successive vertices: the operating conditions of the special cases in Duncan and Duncan are then revealed straightforwardly by the geometric relationships between the images. Our approach may be used to synthesize folding patterns for novel deployable and shape-changing surfaces without need of complex calculation.
Spherical dust collapse in higher dimensions
International Nuclear Information System (INIS)
Goswami, Rituparno; Joshi, Pankaj S.
2004-01-01
We consider here whether it is possible to recover cosmic censorship when a transition is made to higher-dimensional spacetimes, by studying the spherically symmetric dust collapse in an arbitrary higher spacetime dimension. It is pointed out that if only black holes are to result as the end state of a continual gravitational collapse, several conditions must be imposed on the collapsing configuration, some of which may appear to be restrictive, and we need to study carefully if these can be suitably motivated physically in a realistic collapse scenario. It would appear, that, in a generic higher-dimensional dust collapse, both black holes and naked singularities would develop as end states as indicated by the results here. The mathematical approach developed here generalizes and unifies the earlier available results on higher-dimensional dust collapse as we point out. Further, the dependence of black hole or naked singularity end states as collapse outcomes on the nature of the initial data from which the collapse develops is brought out explicitly and in a transparent manner as we show here. Our method also allows us to consider here in some detail the genericity and stability aspects related to the occurrence of naked singularities in gravitational collapse
Scaling laws for spherical pinch experiments
International Nuclear Information System (INIS)
Singh, D.P.; Palleschi, V.; Vaselli, M.
1991-01-01
In spherical pinch (SP) experiments, the plasma heated at the center of a cell to reach ignition temperature is confined by imploding shock waves for a time long enough to satisfy the Lawson criterion for plasma fusion. In earlier theoretical studies, the expansion of the central plasma either is neglected or is assumed to be radially uniform. The energy is considered to be deposited instantaneously at the center of the cell and the nonlinear heat conduction equation is solved to study the temporal evolution of the central plasma. Incorporating the ignition condition for the average temperature of the expanding fireball, and its confinement by imploding convergent shock waves, which may be fired from the periphery of the cell with some time delay, the scaling laws for satisfying the Lawson criterion are investigated in detail. The relevant calculations indicate that the cumulative effects of the convergent shock waves in the vicinity of the center of the cell play an important role in these scaling laws. (author)
Spherical radial basis functions, theory and applications
Hubbert, Simon; Morton, Tanya M
2015-01-01
This book is the first to be devoted to the theory and applications of spherical (radial) basis functions (SBFs), which is rapidly emerging as one of the most promising techniques for solving problems where approximations are needed on the surface of a sphere. The aim of the book is to provide enough theoretical and practical details for the reader to be able to implement the SBF methods to solve real world problems. The authors stress the close connection between the theory of SBFs and that of the more well-known family of radial basis functions (RBFs), which are well-established tools for solving approximation theory problems on more general domains. The unique solvability of the SBF interpolation method for data fitting problems is established and an in-depth investigation of its accuracy is provided. Two chapters are devoted to partial differential equations (PDEs). One deals with the practical implementation of an SBF-based solution to an elliptic PDE and another which describes an SBF approach for solvi...
Failure internal pressure of spherical steel containments
International Nuclear Information System (INIS)
Sanchez Sarmiento, G.
1985-01-01
An application of the British CEGB's R6 Failure Assessment Approach to the determination of failure internal pressure of nuclear power plant spherical steel containments is presented. The presence of hypothetical cracks both in the base metal and in the welding material of the containment, with geometrical idealizations according to the ASME Boiler and Pressure Vessel Code (Section XI), was taken into account in order to analyze the sensitivity of the failure assessment with the values of the material fracture properties. Calculations of the elastoplastic collapse load have been performed by means of the Finite Element System SAMCEF. The clean axisymmetric shell (neglecting the influence of nozzles and minor irregularities) and two major penetrations (personnel and emergency locks) have been taken separately into account. Large-strain elastoplastic behaviour of the material was considered in the Code, using lower bounds of true stress-true strain relations obtained by testing a collection of tensile specimens. Assuming the presence of cracks in non-perturbed regions, the reserve factor for test pressure and the failure internal pressure have been determined as a function of the flaw depth. (orig.)
Synchrotron radiation from spherically accreting black holes
International Nuclear Information System (INIS)
Ipser, J.R.; Price, R.H.
1982-01-01
Spherical accretion onto a Schwartzchild black hole, of gas with frozen-in magnetic field, is studied numerically and analytically for a range of hole masses and accretion rates in which synchrotron emission is the dominant radiative mechanism. At small radii the equipartition of magnetic, kinetic, and gravitational energy is assumed to apply, and the gas is heated by dissipation of infalling magnetic energy, turbulent energy, etc. The models can be classified into three types: (a) synchrotron cooling negligible, (b) synchrotron cooling important but synchrotron self-absorption negligible, (c) synchrotron cooling and self-absorption important. In the first case gas temperatures become very high near the horizon but luminosity efficiencies (luminosity/mass-energy accretion rate) are low. In cases (b) and (c) the gas flow near the horizon is essentially isothermal and luminosity efficiencies are fairly high. The analysis and results for the isothermal cases (b) and (c) are valid only for moderate dissipative heating and synchrotron self-absorption. If self-absorption is very strong or if dissipated energy is comparable to infall energy, Comptonization effects, not included in the analysis, become important
Spherical Process Models for Global Spatial Statistics
Jeong, Jaehong
2017-11-28
Statistical models used in geophysical, environmental, and climate science applications must reflect the curvature of the spatial domain in global data. Over the past few decades, statisticians have developed covariance models that capture the spatial and temporal behavior of these global data sets. Though the geodesic distance is the most natural metric for measuring distance on the surface of a sphere, mathematical limitations have compelled statisticians to use the chordal distance to compute the covariance matrix in many applications instead, which may cause physically unrealistic distortions. Therefore, covariance functions directly defined on a sphere using the geodesic distance are needed. We discuss the issues that arise when dealing with spherical data sets on a global scale and provide references to recent literature. We review the current approaches to building process models on spheres, including the differential operator, the stochastic partial differential equation, the kernel convolution, and the deformation approaches. We illustrate realizations obtained from Gaussian processes with different covariance structures and the use of isotropic and nonstationary covariance models through deformations and geographical indicators for global surface temperature data. To assess the suitability of each method, we compare their log-likelihood values and prediction scores, and we end with a discussion of related research problems.
Transitions between compound states of spherical nuclei
International Nuclear Information System (INIS)
Kadmenskii, S.G.; Markushev, V.P.; Furman, V.I.
1980-01-01
Wigner's statistical matrices are used to study the average reduced g widths and their dispersion for g transitions from a compound state c to another state f, with a lower excitation energy but of arbitrary complexity, for spherical nuclei. It is found that the Porter--Thomas distribution holds for the g widths for all cases of practical interest. In g transitions between compound states c and c' with E/sub g/< or =2 MeV, the most important transitions are M1 transitions involving the major many-quasiparticle components of state c and E1 transitions involving the minor components of state c. It is shown that the strength functions predicted by the various theories for M1 and E1 transitions between compound states with E/sub g/< or =2 MeV are similar. Preference is assigned to the M1-transition version because of experimental results on (n,ga) reactions with thermal and resonance neutrons
Painleve-Gullstrand synchronizations in spherical symmetry
International Nuclear Information System (INIS)
Herrero, Alicia; Morales-Lladosa, Juan Antonio
2010-01-01
A Painleve-Gullstrand synchronization is a slicing of the spacetime by a family of flat space-like 3-surfaces. For spherically symmetric spacetimes, we show that a Painleve-Gullstrand synchronization only exists in the region where (dr) 2 ≤ 1, r being the curvature radius of the isometry group orbits (2-spheres). This condition states that the Misner-Sharp gravitational energy of these 2-spheres is not negative and has an intrinsic meaning in terms of the norm of the mean extrinsic curvature vector. It also provides an algebraic inequality involving the Weyl curvature scalar and the Ricci eigenvalues. We prove that the energy and momentum densities associated with the Weinberg complex of a Painleve-Gullstrand slice vanish in these curvature coordinates, and we give a new interpretation of these slices by using semi-metric Newtonian connections. It is also outlined that, by solving the vacuum Einstein's equations in a coordinate system adapted to a Painleve-Gullstrand synchronization, the Schwarzschild solution is directly obtained in a whole coordinate domain that includes the horizon and both its interior and exterior regions.
M. Larson; D. Bendz; G. Göransson
2013-01-01
The turbidity variation in time and space is investigated in the downstream stretch of the river Göta Älv in Sweden. The river is heavily regulated and carries the discharge from the largest fresh water lake in Sweden, Lake Vänern, to the outflow point in Göteborg Harbour on the Swedish west coast. The river is an important waterway and serves as a fresh-water supply for 700 000 users. Turbidity is utilised as a water quality indicator to ensure sufficient quality of the intake water to the t...
Directory of Open Access Journals (Sweden)
Lee Gyu-sub
2016-01-01
Full Text Available The exhaustion of fossil fuel and the greenhouse gas emission are one of the most significant energy and environmental issues, respectively. Photovoltaic (PV generators and battery energy storage systems (BESSs have been significantly increased for recent years. The BESSs are mainly used for smoothing active power fluctuation of the PV. In this paper, PV–BESSs integration of two DC/DC converters and one AC/DC converter is investigated and DC-link voltage control to compensate the AC voltage deviation is proposed for the PV‒BESS system in low-voltage (LV networks.
The influence of metal Mg on micro-morphology and crystallinity of spherical hexagonal boron nitride
Energy Technology Data Exchange (ETDEWEB)
Zhang, Ning, E-mail: zhangning5832@163.com; Liu, Huan; Kan, Hongmin; Wang, Xiaoyang; Long, Haibo; Zhou, Yonghui
2015-08-15
Highlights: • The action mechanism of Mg to the synthesis of spherical BN was explored. • The influence of Mg content on the crystallinity of h-BN powders was studied. • Even if not added any template, the spherical h-BN could be prepared. - Abstract: This search used the boric acid and borax as a source of boron, urea as a nitrogen source, Mg as metal catalyst, and thus prepared different micro-morphology and crystallinity hexagonal boron nitride powders under a flowing ammonia atmosphere at a nitriding temperature of 750 °C. The effect of Mg content on the crystallinity and micro-morphology of hexagonal boron nitride powders was studied, and the Mg action mechanism was explored. Without the added surfactant, the graphitization index (GI) was 6.87, and the diameter of the spherical h-BN was bigger. When the added Mg were 0.1 g, 0.3 g, 0.5 g and 0.7 g, the (GI) decreased to 6.04, 5.67, 4.62 and 4.84, respectively. When the Mg content was higher (0.9 g), GI value increased rapidly, and the crystallinity became bad. When the Mg content was 0.5 g, the dispersion of h-BN powders was at its optimum and refinement apparently, and the crystallinity at its highest.
Linear analysis on the growth of non-spherical perturbations in supersonic accretion flows
Energy Technology Data Exchange (ETDEWEB)
Takahashi, Kazuya; Yamada, Shoichi, E-mail: ktakahashi@heap.phys.waseda.ac.jp [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku 169-8555 (Japan)
2014-10-20
We analyzed the growth of non-spherical perturbations in supersonic accretion flows. We have in mind an application to the post-bounce phase of core-collapse supernovae (CCSNe). Such non-spherical perturbations have been suggested by a series of papers by Arnett, who has numerically investigated violent convections in the outer layers of pre-collapse stars. Moreover, Couch and Ott demonstrated in their numerical simulations that such perturbations may lead to a successful supernova even for a progenitor that fails to explode without fluctuations. This study investigated the linear growth of perturbations during the infall onto a stalled shock wave. The linearized equations are solved as an initial and boundary value problem with the use of a Laplace transform. The background is a Bondi accretion flow whose parameters are chosen to mimic the 15 M {sub ☉} progenitor model by Woosley and Heger, which is supposed to be a typical progenitor of CCSNe. We found that the perturbations that are given at a large radius grow as they flow down to the shock radius; the density perturbations can be amplified by a factor of 30, for example. We analytically show that the growth rate is proportional to l, the index of the spherical harmonics. We also found that the perturbations oscillate in time with frequencies that are similar to those of the standing accretion shock instability. This may have an implication for shock revival in CCSNe, which will be investigated in our forthcoming paper in more detail.
Hoshyaripour, A.; Vogel, B.; Vogel, H.
2017-12-01
Mineral dust, emitted from arid and semi-arid regions, is the most dominant atmospheric aerosol by mass. Beside detrimental effect on air quality, airborne dust also influences the atmospheric radiation by absorbing and scattering solar and terrestrial radiation. As a result, while the long-term radiative impacts of dust are important for climate, the short-term effects are significant for the photovoltaic energy production. Therefore, it is a vital requirement to accurately forecast the effects of dust on energy budget of the atmosphere and surface. To this end, a major issue is the fact that dust particles are non-spherical. Thus, the optical properties of such particles cannot be calculated precisely using the conventional methods like Mie theory that are often used in climate and numerical weather forecast models. In this study, T-Matrix method is employed, which is able to treat the non-sphericity of particles. Dust particles are assumed to be prolate spheroids with aspect ratio of 1.5 distributed in three lognormal modes. The wavelength-dependent refractive indices of dust are used in T-Matrix algorithm to calculate the extinction coefficient, single scattering albedo, asymmetry parameter and backscattering ratio at different wavelengths. These parameters are then implemented in ICON-ART model (ICOsahedral Nonhydrostatic model with Aerosols and Reactive Trace gases) to conduct a global simulation with 80 km horizontal resolution and 90 vertical levels. April 2014 is selected as the simulation period during which North African dust plumes reached central Europe and Germany. Results show that treatment of non-sphericity reduces the dust AOD in the range of 10 to 30%/. The impacts on diffuse and direct radiation at global, regional and local scales show strong dependency on the size distribution of the airborne dust. The implications for modeling and remote sensing the dust impacts on solar energy are also discussed.
Bioinspired adaptive gradient refractive index distribution lens
Yin, Kezhen; Lai, Chuan-Yar; Wang, Jia; Ji, Shanzuo; Aldridge, James; Feng, Jingxing; Olah, Andrew; Baer, Eric; Ponting, Michael
2018-02-01
Inspired by the soft, deformable human eye lens, a synthetic polymer gradient refractive index distribution (GRIN) lens with an adaptive geometry and focal power has been demonstrated via multilayer coextrusion and thermoforming of nanolayered elastomeric polymer films. A set of 30 polymer nanolayered films comprised of two thermoplastic polyurethanes having a refractive index difference of 0.05 were coextruded via forced-assembly technique. The set of 30 nanolayered polymer films exhibited transmission near 90% with each film varying in refractive index by 0.0017. An adaptive GRIN lens was fabricated from a laminated stack of the variable refractive index films with a 0.05 spherical GRIN. This lens was subsequently deformed by mechanical ring compression of the lens. Variation in the optical properties of the deformable GRIN lens was determined, including 20% variation in focal length and reduced spherical aberration. These properties were measured and compared to simulated results by placido-cone topography and ANSYS methods. The demonstration of a solid-state, dynamic focal length, GRIN lens with improved aberration correction was discussed relative to the potential future use in implantable devices.
DEFF Research Database (Denmark)
Osmanagic, Armin; Möller, Sören; Osmanagic, Azra
2016-01-01
BACKGROUND: Attempts to achieve rhythm control using direct-current cardioversion (DCC) are common in those with persistent atrial fibrillation (AF). Although often successful, AF recurs within 1 month in as many as 57% of patients. The aim of this study was to assess whether a baseline left atri...
HFE and Spherical Cryostats MC Study
International Nuclear Information System (INIS)
Brodsky, Jason P.
2016-01-01
The copper vessel containing the nEXO TPC is surrounded by a buffer of HFE, a liquid refrigerant with very low levels of radioactive element contamination. The HFE is contained within the cryostat's inner vessel, which is in turn inside the outer vessel. While some HFE may be necessary for stable cooling of nEXO, it is possible that using substantially more than necessary for thermal reasons will help reduce backgrounds originating in the cryostats. Using a larger amount of HFE is accomplished by making the cryostat vessels larger. By itself, increasing the cryostat size somewhat increases the background rate, as the thickness of the cryostat wall must increase at larger sizes. However, the additional space inside the cryostat will be filled with HFE which can absorb gamma rays headed for the TPC. As a result, increasing the HFE reduces the number of backgrounds reaching the TPC. The aim of this study was to determine the relationship between HFE thickness and background rate. Ultimately, this work should support choosing a cryostat and HFE size that satisfies nEXO's background budget. I have attempted to account for every consequence of changing the cryostat size, although naturally this remains a work in progress until a final design is achieved. At the moment, the scope of the study includes only the spherical cryostat design. This study concludes that increasing cryostat size reduces backgrounds, reaching neglible backgrounds originating from the cryostat at the largest sizes. It also shows that backgrounds originating from the inherent radioactivity of the HFE plateau quickly, so may be considered essentially fixed at any quantity of HFE.
Assessment of the LV-C2 Stack Sampling Probe Location for Compliance with ANSI/HPS N13.1-1999
Energy Technology Data Exchange (ETDEWEB)
Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Antonio, Ernest J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flaherty, Julia E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2015-09-01
This document reports on a series of tests conducted to assess the proposed air sampling location for the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Low-Activity Waste (LAW) C2V (LV-C2) exhaust stack with respect to the applicable criteria regarding the placement of an air sampling probe. Federal regulations require that a sampling probe be located in the exhaust stack according to the criteria established by the American National Standards Institute/Health Physics Society (ANSI/HPS) N13.1-1999, Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities. These criteria address the capability of the sampling probe to extract a sample that represents the effluent stream. The tests were conducted on the LV-C2 scale model system. Based on the scale model tests, the location proposed for the air sampling probe in the scale model stack meets the requirements of the ANSI/HPS N13.1-1999 standard for velocity uniformity, flow angle, gas tracer and particle tracer uniformity. Additional velocity uniformity and flow angle tests on the actual stack will be necessary during cold startup to confirm the validity of the scale model results in representing the actual stack.
DEFF Research Database (Denmark)
Flores, German Antonio Enriquez; Fotidis, Ioannis; Karakashev, Dimitar Borisov
2015-01-01
In this study, the individual and synergistic toxicity of the following xenobiotics: Benzalkonium Chloride (BKC), Proxel LV (PRX), P3 Hypochloran (HPC), Triton X-100 (TRX), and DOWFAX 63N10 (DWF), on anaerobic digestion (AD) process, was assessed. The experiments were performed in batch and conti......In this study, the individual and synergistic toxicity of the following xenobiotics: Benzalkonium Chloride (BKC), Proxel LV (PRX), P3 Hypochloran (HPC), Triton X-100 (TRX), and DOWFAX 63N10 (DWF), on anaerobic digestion (AD) process, was assessed. The experiments were performed in batch...... and continuous (up-flow anaerobic sludge blanket, UASB) reactors with biochemical-industrial wastewater, as substrate. In batch experiments, half-maximal inhibitory concentrations (IC50) for the tested xenobiotics were found to be 13.1, 1003, 311.5 and 24.3 mg L1 for BKC, PRX, DWF and TRX, respectively while HPC...... observed from the batch reactors. Oppositely, TRX showed no inhibition in continuous mode, while inhibition was detected at batch mode....
Sobrinho, Ludmila Silva Vicente; Rossi, Cláudio Nazaretian; Vides, Juliana Peloi; Braga, Eveline Tozzi; Gomes, Ana Amélia Domingues; de Lima, Valéria Marçal Félix; Perri, Sílvia Helena Venturoli; Generoso, Diego; Langoni, Hélio; Leutenegger, Christian; Biondo, Alexander Welker; Laurenti, Márcia Dalastra; Marcondes, Mary
2012-06-08
The aim of the present study was to determine the coinfection of Leishmania sp. with Toxoplasma gondii, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in a population of cats from an endemic area for zoonotic visceral leishmaniasis. An overall 66/302 (21.85%) cats were found positive for Leishmania sp., with infection determined by direct parasitological examination in 30/302 (9.93%), by serology in 46/302 (15.23%) and by both in 10/302 (3.31%) cats. Real time PCR followed by amplicon sequencing successfully confirmed Leishmania infantum (syn Leishmania chagasi) infection. Out of the Leishmania infected cats, coinfection with FIV was observed in 12/66 (18.18%), with T. gondii in 17/66 (25.75%) and with both agents in 5/66 (7.58%) cats. FeLV was found only in a single adult cat with no Leishmania infection. A positive association was observed in coinfection of Leishmania and FIV (p0.05). In conclusion, cats living in endemic areas of visceral leishmaniasis are significantly more likely to be coinfected with FIV, which may present confounding clinical signs and therefore cats in such areas should be always carefully screened for coinfections. Copyright © 2012 Elsevier B.V. All rights reserved.
Electrically small circularly polarized spherical antenna with air core
DEFF Research Database (Denmark)
Kim, O. S.
2013-01-01
An electrically small circularly polarized self-resonant spherical antenna with air core is presented. The antenna is a modified multiarm spherical helix exciting TM10 and TE10 spherical modes with equal radiated power, and thus yielding perfect circular polarization over the entire far......-field sphere (except the polar regions, where the radiation is low). The self-resonance is achieved by exciting higher-order TM modes, which provide the necessary electric stored energy in the near-field, while contributing negligibly to the far-field radiation of the antenna. The antenna has electrical size...
Spherical reconciliation for a continuous-variable quantum key distribution
International Nuclear Information System (INIS)
Lu Zhao; Shi Jian-Hong; Li Feng-Guang
2017-01-01
Information reconciliation is a significant step for a continuous-variable quantum key distribution (CV-QKD) system. We propose a reconciliation method that allows two authorized parties to extract a consistent and secure binary key in a CV-QKD protocol, which is based on Gaussian-modulated coherent states and homodyne detection. This method named spherical reconciliation is based on spherical quantization and non-binary low-density parity-check (LDPC) codes. With the suitable signal-to-noise ratio (SNR) and code rate of non-binary LDPC codes, spherical reconciliation algorithm has a high efficiency and can extend the transmission distance of CV-QKD. (paper)
Virial theorem and hypervirial theorem in a spherical geometry
International Nuclear Information System (INIS)
Li Yan; Chen Jingling; Zhang Fulin
2011-01-01
The virial theorem in the one- and two-dimensional spherical geometry are presented in both classical and quantum mechanics. Choosing a special class of hypervirial operators, the quantum hypervirial relations in the spherical spaces are obtained. With the aid of the Hellmann-Feynman theorem, these relations can be used to formulate a perturbation theorem without wavefunctions, corresponding to the hypervirial-Hellmann-Feynman theorem perturbation theorem of Euclidean geometry. The one-dimensional harmonic oscillator and two-dimensional Coulomb system in the spherical spaces are given as two sample examples to illustrate the perturbation method. (paper)
Non-Spherical Microcapsules for Increased Core Content Volume Delivery
Oliva-Buisson, Yvette J.
2014-01-01
The goal of this project was to advance microencapsulation from the standard spherical microcapsule to a non-spherical, high-aspect ratio (HAR), elongated microcapsule. This was to be accomplished by developing reproducible methods of synthesizing or fabricating robust, non-spherical, HAR microcapsules. An additional goal of this project was to develop the techniques to the point where scale-up of these methods could be examined. Additionally, this project investigated ways to apply the microencapsulation techniques developed as part of this project to self-healing formulations.
International Nuclear Information System (INIS)
Grann, Alison; Minsky, Bruce D.; Cohen, Alfred M.; Saltz, Leonard; Kelsen, David P.; Kemeny, Nancy; Ilson, David; Guillem, Jose G.; Paty, Philip B.; Bass, Joanne
1996-01-01
PURPOSE: We report the downstaging, acute toxicity, and preliminary local control and survival of pre-op 5-FU, low dose LV, and concurrent RT followed by post-op LV/5-FU for pts with clinically resectable, T3 rectal cancer. MATERIALS AND METHODS: A total of 32 pts (M:26, F:6) were prospectively treated from 12/91-8/95. Eligibility criteria included adequate hematologic indicies, primary adenocarcinoma limited to the pelvis, and T3 disease confirmed by transrectal ultrasound. Twenty five pts were considered clinically to require an APR on initial (pre-treatment) assessment by their operating surgeon. The median age was 56 (range: 24-80), and the median distance from the anal verge was 5.0cm (range: 3-9cm). Pts received 2 monthly cycles (bolus daily X 5) of LV (20mg/m2) and 5-FU (325mg/m2), beginning concurrently with day 1 of RT, followed by surgery 4-5 weeks later. RT included 4680 cGy to the pelvis followed by a boost to 5040 cGy. Post-operatively, pts received a median of 2 monthly cycles (range: 0-10 cycles) of LV (20 mg/m2) and 5-FU (425mg/m2). A toxicity assessment was performed at each visit using the NCI toxicity criteria modified for gastrointestinal toxicity. The median follow-up was 12 months (range: 3-48 months). All 32 patients were included in the analysis of toxicity, sphincter preservation, and downstaging. Analysis of patterns of failure and survival was limited to the 15 pts who had a minimum follow-up of 1yr or developed failure prior to 1 yr. For this subset the median follow-up was 24 months (range: 3-48 months). RESULTS: During the pre-op segment, individual grade 3+ acute toxicities were; diarrhea: 16%, bowel movements: 16%, leukopenia: 12%. The incidence of total toxicity was 25% ((8(32))). The median nadir counts were; WBC: 2.9 (range: 1.7-5.6), HGB: 12.4 (range: 7.1-15.0), and PLT (X1000): 161 (range: 113-237). The pathologic complete response rate was 9% ((3(32))). An additional 13% ((4(32))) had negative lymph nodes and 1-2 microscopic
Design innovations of the next-step spherical torus experiment and spherical torus development path
International Nuclear Information System (INIS)
Ono, M.; Kessel, C.; Peng, M.
2003-01-01
The spherical torus (ST) fusion energy development path is complementary to the tokamak burning plasma experiment such as ITER as it focuses toward the compact Component Test Facility (CTF) and higher toroidal beta regimes to improve the design of DEMO and a Power Plant. To support the ST development path, one option of a Next Step Spherical Torus (NSST) device is examined. NSST is a 'performance extension' (PE) stage ST with a plasma current of 5 - 10 MA, R = 1.5, B T ≤ 2.7 T with flexible physics capability to 1) Provide a sufficient physics basis for the design of the CTF, 2) Explore advanced operating scenarios with high bootstrap current fraction/high performance regimes, which can then be utilized by CTF, DEMO, and Power Plants, 3) Contribute to the general plasma/fusion science of high β toroidal plasmas. The NSST facility is designed to utilize the TFTR site to minimize the cost and time required for the construction. (author)
International Nuclear Information System (INIS)
Ono, M.; Peng, M.; Kessel, C.; Neumeyer, C.; Schmidt, J.; Chrzanowski, J.; Darrow, D.; Grisham, L.; Heitzenroeder, P.; Jarboe, T.; Jun, C.; Kaye, S.; Menard, J.; Raman, R.; Stevenson, T.; Viola, M.; Wilson, J.; Woolley, R.; Zatz, I.
2003-01-01
A spherical torus (ST) fusion energy development path which is complementary to proposed tokamak burning plasma experiments such as ITER is described. The ST strategy focuses on a compact Component Test Facility (CTF) and higher performance advanced regimes leading to more attractive DEMO and Power Plant scale reactors. To provide the physics basis for the CTF an intermediate step needs to be taken which we refer to as the ''Next Step Spherical Torus'' (NSST) device and examine in some detail herein. NSST is a ''performance extension'' (PE) stage ST with the plasma current of 5-10 MA, R = 1.5 m, and Beta(sub)T less than or equal to 2.7 T with flexible physics capability. The mission of NSST is to: (1) provide a sufficient physics basis for the design of CTF, (2) explore advanced operating scenarios with high bootstrap current fraction/high performance regimes, which can then be utilized by CTF, DEMO, and Power Plants, and (3) contribute to the general plasma/fusion science of high beta toroidal plasmas. The NSST facility is designed to utilize the Tokamak Fusion Test Reactor (or similar) site to minimize the cost and time required for the design and construction
African Journals Online (AJOL)
Items 151 - 200 of 229 ... Vol 17, No 1 (2005), Obtaining the green's function for electromagnetic waves propagating in layered in-homogeneous thin film media of spherical ... screens within Benue State University, Makurdi, Nigeria, Abstract.
Analytic theory of the spherical electron to ion convertor
International Nuclear Information System (INIS)
Verdeyen, J.T.; Miller, P.A.
1980-01-01
Calculations will be presented which indicate that one could, with high efficiency, convert the electron beam energy transported from many pinched diode to ions at a reasonably sized evacuated spherical shell - or a light bulb
Turbulence Modulation by Non-Spherical Particles
DEFF Research Database (Denmark)
Mandø, Matthias
This study deals with the interaction between turbulence and non-spherical particles and represents an extension of the modeling framework for particleladen flows. The effect of turbulence on particles is commonly referred to as turbulent dispersion while the effect of particles on the carrier....... This study encompass an outlook on existing work, an experimental study, development of a numerical model and a case study advancing the modeling techniques for pulverized coal combustion to deal with larger non-spherical biomass particles. Firstly, existing knowledge concerning the motion of non......-spherical particles and turbulence modulation are outlined. A complete description of the motion of non-spherical particles is still lacking. However, evidence suggests that the equation of motion for a sphere only represent an asymptotical value for a more general, but yet unformulated, description of the motion...
Ultrasmooth, Highly Spherical Monocrystalline Gold Particles for Precision Plasmonics
Lee, You-Jin; Schade, Nicholas B.; Sun, Li; Fan, Jonathan A.; Bae, Doo Ri; Mariscal, Marcelo M.; Lee, Gaehang; Capasso, Federico; Sacanna, Stefano; Manoharan, Vinothan N.; Yi, Gi-Ra
2013-01-01
isotropic, so that spheres are favored under quasi-static conditions. It is scalable up to particle sizes of 200 nm or more. The resulting spherical crystals display uniform scattering spectra and consistent optical coupling at small separations, even
Spherical convolutions and their application in molecular modelling
DEFF Research Database (Denmark)
Boomsma, Wouter; Frellsen, Jes
2017-01-01
Convolutional neural networks are increasingly used outside the domain of image analysis, in particular in various areas of the natural sciences concerned with spatial data. Such networks often work out-of-the box, and in some cases entire model architectures from image analysis can be carried over...... to other problem domains almost unaltered. Unfortunately, this convenience does not trivially extend to data in non-euclidean spaces, such as spherical data. In this paper, we introduce two strategies for conducting convolutions on the sphere, using either a spherical-polar grid or a grid based...... of spherical convolutions in the context of molecular modelling, by considering structural environments within proteins. We show that the models are capable of learning non-trivial functions in these molecular environments, and that our spherical convolutions generally outperform standard 3D convolutions...
A variational solution of transport equation based on spherical geometry
International Nuclear Information System (INIS)
Liu Hui; Zhang Ben'ai
2002-01-01
A variational method with differential forms gives better precision for numerical solution of transport critical problem based on spherical geometry, and its computation seems simple than other approximate methods
Spherical loudspeaker array for local active control of sound.
Rafaely, Boaz
2009-05-01
Active control of sound has been employed to reduce noise levels around listeners' head using destructive interference from noise-canceling sound sources. Recently, spherical loudspeaker arrays have been studied as multiple-channel sound sources, capable of generating sound fields with high complexity. In this paper, the potential use of a spherical loudspeaker array for local active control of sound is investigated. A theoretical analysis of the primary and secondary sound fields around a spherical sound source reveals that the natural quiet zones for the spherical source have a shell-shape. Using numerical optimization, quiet zones with other shapes are designed, showing potential for quiet zones with extents that are significantly larger than the well-known limit of a tenth of a wavelength for monopole sources. The paper presents several simulation examples showing quiet zones in various configurations.
On a randomly imperfect spherical cap pressurized by a random ...
African Journals Online (AJOL)
On a randomly imperfect spherical cap pressurized by a random dynamic load. ... In this paper, we investigate a dynamical system in a random setting of dual ... characterization of the random process for determining the dynamic buckling load ...
Some comments on the hydrogen atom in a spherical enclosure
International Nuclear Information System (INIS)
Aguilera-Navarro, V.C.; Koo, E.L.; Zimerman, A.H.
1980-01-01
Some properties of the ground state energy solutions for the hydrogen atom in a spherical enclosure are discussed. The application of the many-point Pade approximants to this kind of systems inside a box is consider also. (Author) [pt
Spherical collapse in quintessence models with zero speed of sound
International Nuclear Information System (INIS)
Creminelli, Paolo; D'Amico, Guido; Noreña, Jorge; Senatore, Leonardo; Vernizzi, Filippo
2010-01-01
We study the spherical collapse model in the presence of quintessence with negligible speed of sound. This case is particularly motivated for w Q /Ω m . This gives a distinctive modification of the total mass function at low redshift
Aircraft navigation and surveillance analysis for a spherical earth
2014-10-01
This memorandum addresses a fundamental function in surveillance and navigation analysis : quantifying the geometry of two or more locations relative to each other and to a spherical earth. Here, geometry refers to: (a) points (idealized lo...
Electron Optics for Biologists: Physical Origins of Spherical Aberrations
Geissler, Peter; Zadunaisky, Jose
1974-01-01
Reports on the physical origins of spherical aberrations in axially symmetric electrostatic lenses to convey the essentials of electon optics to those who must think critically about the resolution of the electron microscope. (GS)
Volume of the domain visited by N spherical Brownian particles
International Nuclear Information System (INIS)
Berezhkovskii, A.M.
1994-01-01
The average value and variance of the volume of the domain visited in time t by N spherical Brownian particles starting initially at the same point are presented as quadratures of the solutions of simple diffusion problems of the survival of a point Brownian particle in the presence of one and two spherical traps. As an illustration, explicit time dependences are obtained for the average volume in one and three dimensions
Fluorescence of molecules placed near a spherical particle: Rabi splitting
Directory of Open Access Journals (Sweden)
M.M. Dvoynenko
2017-12-01
Full Text Available Theoretical study of spontaneously emitted spectra of point-like source placed near spherical Ag particle was performed. It was shown that near-field electromagnetic interaction between a point-like emitter and spherical Ag particle leads to strong coupling between them at very small emitter-metal surface distances. It was shown that values of Rabi splitting are quantitatively close to that of emitter-flat substrate interaction.
Effect of Rolling Resistance in Dem Models With Spherical Bodies
Directory of Open Access Journals (Sweden)
Dubina Radek
2016-12-01
Full Text Available The rolling resistance is an artificial moment arising on the contact of two discrete elements which mimics resistance of two grains of complex shape in contact rolling relatively to each other. The paper investigates the influence of rolling resistance on behaviour of an assembly of spherical discrete elements. Besides the resistance to rolling, the contacts between spherical particles obey the Hertzian law in normal straining and Coulomb model of friction in shear.
Features of spherical uranium-graphite HTGR fuel elements control
International Nuclear Information System (INIS)
Kreindlin, I.I.; Oleynikov, P.P.; Shtan, A.S.
1985-01-01
Control features of spherical HTGR uranium-graphite fuel elements with spherical coated fuel particles are mainly determined by their specific construction and fabrication technology. The technology is chiefly based on methods of ceramic fuel (fuel microspheres fabrication) and graphite production practice it is necessary to deal with a lot of problems from determination of raw materials properties to final fuel elements testing. These procedures are described
Features of spherical uranium-graphite HTGR fuel elements control
Energy Technology Data Exchange (ETDEWEB)
Kreindlin, I I; Oleynikov, P P; Shtan, A S
1985-07-01
Control features of spherical HTGR uranium-graphite fuel elements with spherical coated fuel particles are mainly determined by their specific construction and fabrication technology. The technology is chiefly based on methods of ceramic fuel (fuel microspheres fabrication) and graphite production practice it is necessary to deal with a lot of problems from determination of raw materials properties to final fuel elements testing. These procedures are described.
Minimum Q Electrically Small Spherical Magnetic Dipole Antenna - Theory
DEFF Research Database (Denmark)
Breinbjerg, Olav; Kim, Oleksiy S.
2009-01-01
The stored energies, radiated power, and quality factor of a magnetic-dipole antenna, consisting of a spherical electrical surface current density enclosing a magnetic core, is obtained through direct spatial integration of the internally and externally radiated field expressed in terms...... of spherical vector waves. The obtained quality factor agrees with that of Wheeler and Thal for vanishing free-space electric radius but holds also for larger radii and facilitates the optimal choice of permeability in the presence of the resonances....
Models for randomly distributed nanoscopic domains on spherical vesicles
Anghel, Vinicius N. P.; Bolmatov, Dima; Katsaras, John
2018-06-01
The existence of lipid domains in the plasma membrane of biological systems has proven controversial, primarily due to their nanoscopic size—a length scale difficult to interrogate with most commonly used experimental techniques. Scattering techniques have recently proven capable of studying nanoscopic lipid domains populating spherical vesicles. However, the development of analytical methods able of predicting and analyzing domain pair correlations from such experiments has not kept pace. Here, we developed models for the random distribution of monodisperse, circular nanoscopic domains averaged on the surface of a spherical vesicle. Specifically, the models take into account (i) intradomain correlations corresponding to form factors and interdomain correlations corresponding to pair distribution functions, and (ii) the analytical computation of interdomain correlations for cases of two and three domains on a spherical vesicle. In the case of more than three domains, these correlations are treated either by Monte Carlo simulations or by spherical analogs of the Ornstein-Zernike and Percus-Yevick (PY) equations. Importantly, the spherical analog of the PY equation works best in the case of nanoscopic size domains, a length scale that is mostly inaccessible by experimental approaches such as, for example, fluorescent techniques and optical microscopies. The analytical form factors and structure factors of nanoscopic domains populating a spherical vesicle provide a new and important framework for the quantitative analysis of experimental data from commonly studied phase-separated vesicles used in a wide range of biophysical studies.
International Nuclear Information System (INIS)
Serrano R, M. L.
2015-09-01
This article describes some of the work done in the Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS) to define specifically the requirements that the Federal Electricity Commission (CFE) shall meet to submit for consideration of CNSNS an operation request of an Independent Spent Fuel Dry Storage Installation (ISFSI). The project of a facility of this type arose from the need to provide storage capacity for spent nuclear fuel in the nuclear power plant of Laguna Verde (NPP-LV) and to continue the operation at the same facility in a safe manner. The licensing of these facilities in the United States of America has two modes: specific license or general license. The characteristics of these licenses are described in this article. However, in Mexico the existing national legislation is not designed for such license types, in fact there is a lack of standards or regulations in this regard. The regulatory law of Article 27 of the Constitution in the nuclear matter, only generally establishes that this type of facility requires an authorization from the Ministry of Energy. For this reason and because there is not a national legislation, was necessary to use the legislation that provides the Nuclear Regulatory Commission of USA, the US NRC. However, it cannot be applied as is established, so was necessary that the CNSNS analyze one by one the requirements of both types of license and determine what would be required to NPP-LV to submit its operating license of ISFSI. The American regulatory applicable to an ISFSI, the 10-Cfr-72 of the US NRC, establishes the requirements for both types of licenses. Chapter 10-Cfr was analyzed in all its clauses and coupled to the laws, regulations and standards as well as to the requirements established by CNSNS, all associated with a store spent fuel on site; the respective certification of containers for spent fuel dry storage was not included in this article, even though the CNSNS also performed that activity under the
Yu, P. S.; Liao, C. J.; Chen, M. T.; Zou, J. J.; Shi, X.; Bosin, A. A.; Gorbarenko, S. A.
2017-12-01
Sea surface temperature (SST) records from the subarctic Northwestern (NW) Pacific are ideal for reconstructing regional paleoceanographic changes sensitive to global climate change. Core LV 63-41-2 (52.56°N, 160.00° E; water depth 1924 m) retrieved from a high sedimentation site, in which the interactions of the Bering Sea and the warm water mass from the NW Pacific are highly dynamic. Here we reported high-resolution last glacial alkenone-based records from Core LV 63-41-2. Prior to 27-16 ka BP high glacial C37:4 alkenone concentrations indicate large amount of fresh water influencing the surface water of the NW Pacific with a reaching to the Site LV 63-41-2. We further inferred that during the last glacial the low salinity water may be formed from the ice-melting water on site and/or brought by the surface current from the Bering Sea, and are efficient in producing strong water stratification condition. The stratification weakens vertical mixing of the upper water column, that in turn decreases the nutrients upwelled from deep to the surface therefore causes low productivity of coccolithophorids. During the early Bølling-Allerød (B/A) period, a gradual increasing alkenone-SST and associated with high C37:4 alkenone concentrations, implying that a weakened stratification and much stronger nutrient upwelling of the early B/A period than that of the glacial. The late B/A period is characterized by an abrupt warming with possibly more melting sea ices in the Bering Sea and the coast near the Kamchatka Peninsula. The large amount of fresh water lens formed during the ice melting might have ceased vertical mixing and upwelling in the upper water column as evidenced by a decline of biological productivity of both calcerous and soliceous organism during late B/A. We suggest an early warming and low productivity in the NW Pacific that is coincident with a rapid cooling in most of the Northern Hemisphere high latitudes during the Younger Dryas.
Cong, Wei; Meng, Qing-Feng; Blaga, Radu; Villena, Isabelle; Zhu, Xing-Quan; Qian, Ai-Dong
2016-01-01
This study was conducted to estimate the prevalence of Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections among stray and pet cats in Lanzhou, northwest China, and to identify the influence of age, gender, and regions on seropositivity. T. gondii antibodies were examined in cat sera by the modified agglutination test (MAT). The circulating antigens of D. immitis and FeLV and specific antibodies to FIV were examined using kits commercially available. The overall prevalence of T. gondii, FIV, FeLV, and D. immitis was 19.34, 9.12, 11.33, and 3.04 %, respectively. For the genetic characterization of T. gondii genotypes in cats, genomic DNA was extracted from the seropositive cats and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genotyped using multilocus PCR-RFLP. Two T. gondii genotypes (ToxoDB#9 and ToxoDB#1) were identified. Results of the multivariate logistic regression analysis showed that older cats are more likely to be seropositive than juveniles for T. gondii, FIV, FeLV, and D. immitis. This is the first report of T. gondii genotypes in cats in northwest China. Moreover, the present study is the first study of retrovirus and D. immitis seroprevalence in cats in China. The results revealed that T. gondii, FIV, and FeLV infections are common in stray and pet cats in northwest China.
Directory of Open Access Journals (Sweden)
Chirojit Mukherjee
2012-01-01
Full Text Available Echocardiographic assessment of systolic left ventricular (LV function in patients with severe mitral regurgitation (MR undergoing mitral valve (MV repair can be challenging because the measurement of ejection fraction (EF or fractional area change (FAC in pathological states is of questionable value. The aim of our study was to evaluate the usefulness of the pre-operative Tei Index in predicting left ventricular EF or FAC immediately after MV repair. One hundred and thirty patients undergoing MV repair with sinus rhythm pre- and post-operatively were enrolled in this prospective study. Twenty-six patients were excluded due to absence of sinus rhythm post-operatively. Standard transesophageal examination(IE 33,Philips,Netherlands was performed before and after cardiopulmonary bypass according to the guidelines of the ASE/SCA. FAC was determined in the transgastric midpapillary short-axis view. LV EF was measured in the midesophageal four- and two-chamber view. For calculation of the Tei Index, the deep transgastric and the midesophageal four-chamber view were used. Statistical analysis was performed with SPSS 17.0. values are expressed as mean with standard deviation. LV FAC and EF decreased significantly after MV repair (FAC: 56±12% vs. 50±14%, P<0.001; EF: 58±11 vs. 50±12Έ P<0.001. The Tei Index decreased from 0.66±0.23 before MV repair to 0.41±0.19 afterwards (P<0.001. No relationship between pre-operative Tei Index and post-operative FAC or post-operative EF were found (FAC: r=−0.061, P=0.554; EF: r=−0.29, P=0.771. Conclusion: Pre-operative Tei Index is not a good predictor for post-operative FAC and EF in patients undergoing MV repair.
Spherical grating based x-ray Talbot interferometry
Energy Technology Data Exchange (ETDEWEB)
Cong, Wenxiang, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Xi, Yan, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu; Wang, Ge, E-mail: congw@rpi.edu, E-mail: xiy2@rpi.edu, E-mail: wangg6@rpi.edu [Biomedical Imaging Center, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)
2015-11-15
Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and
Spherical grating based x-ray Talbot interferometry
International Nuclear Information System (INIS)
Cong, Wenxiang; Xi, Yan; Wang, Ge
2015-01-01
Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and
Energy Technology Data Exchange (ETDEWEB)
Akbar, M.M., E-mail: akbar@utdallas.edu
2017-06-10
It is well known that static spherically symmetric spacetimes can admit foliations by flat spacelike hypersurfaces, which are best described in terms of the Painlevè–Gullstrand coordinates. The uniqueness and existence of such foliations were addressed earlier. In this paper, we prove, purely geometrically, that any possible foliation of a static spherically symmetric spacetime by an arbitrary codimension-one spherical spacelike geometry, up to time translation and rotation, is unique, and we find the algebraic condition under which it exists. This leads us to what can be considered as the most natural generalization of the Painlevè–Gullstrand coordinate system for static spherically symmetric metrics, which, in turn, makes it easy to derive generic conclusions on foliation and to study specific cases as well as to easily reproduce previously obtained generalizations as special cases. In particular, we note that the existence of foliation by flat hypersurfaces guarantees the existence of foliation by hypersurfaces whose Ricci curvature tensor is everywhere non-positive (constant negative curvature is a special case). The study of uniqueness and the existence concurrently solves the question of embeddability of a spherical spacelike geometry in one-dimensional higher static spherically symmetric spacetimes, and this produces known and new results geometrically, without having to go through the momentum and Hamiltonian constraints.
Apte, M; McGwin, G; Vilá, L M; Kaslow, R A; Alarcón, G S; Reveille, J D
2008-03-01
To examine the factors associated with myocarditis and its impact on disease outcomes in SLE patients. SLE patients aged > or = 16 yrs, disease duration NAture vs nurture), a multiethnic US cohort, were studied. Myocarditis was defined as per the category 3 of the pericarditis/myocarditis item of the SLAM-Revised (SLAM-R). Patients with concurrent pericardial involvement were excluded. Patients with myocarditis were compared with those without myocarditis or its sequelae in the preceding year. The association between myocarditis and baseline variables (T(0)) was first examined. The impact of myocarditis on disease activity over time (SLAM-R), damage accrual [SLICC Damage Index (SDI)] at last visit (T(L)) and mortality was evaluated. Fifty-three of the 496 patients studied had myocarditis. African American ethnicity [Odds ratio (OR) = 12.6; 95% CI 1.6, 97.8] and SLAM-R at diagnosis (OR = 1.1, 95% CI 1.0, 1.1) were significantly and independently associated with myocarditis. Myocarditis did not predict disease activity over time, but approached significance as a predictor of SDI at T(L) in multivariable analyses P = 0.051. Kaplan-Meier curves indicated that myocarditis was associated with shorter survival (log-rank = 4.87, P = 0.02), particularly in patients with > or = 5 yrs disease; however, myocarditis was not retained in the Cox proportional hazards regression model. Ethnicity and disease activity at diagnosis were associated with the occurrence of myocarditis in SLE. Myocarditis did not significantly impact on disease activity over time, but impacts some on damage accrual and survival, reflecting overall the more severe disease those patients experience.
Energy Technology Data Exchange (ETDEWEB)
Perusquia, R.; Arredondo S, C.; Hernandez M, J. L.; Montes T, J. L.; Castillo M, A.; Ortiz S, J. J., E-mail: raul.perusquia@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)
2015-09-15
This paper presents the development of tools to facilitate the management so much, the operational monitoring of boiling water reactors (BWR) of the nuclear power plant of Laguna Verde (NPP-LV) through independent codes, and how to carry out the static calculations corresponding to process of optimized pre-design of the reference cycle next to current cycle. The progress and preliminary results obtained with the program SACal, developed at Instituto Nacional de Investigaciones Nucleares (ININ), central tool to achieve provide a management platform of the operational monitoring and pre-design of NPP-LV cycle are also described. The reached preliminary advances directed to get an Analysis center and automated design of fuel assembly cells are also presented, which together with centers or similar modules related with the fuel reloads form the key part to meet the targets set for the realization of a Management Platform of Nuclear Fuel of the NPP-LV. (Author)
Hawking radiation from a spherical loop quantum gravity black hole
International Nuclear Information System (INIS)
Gambini, Rodolfo; Pullin, Jorge
2014-01-01
We introduce quantum field theory on quantum space-times techniques to characterize the quantum vacua as a first step toward studying black hole evaporation in spherical symmetry in loop quantum gravity and compute the Hawking radiation. We use as quantum space-time the recently introduced exact solution of the quantum Einstein equations in vacuum with spherical symmetry and consider a spherically symmetric test scalar field propagating on it. The use of loop quantum gravity techniques in the background space-time naturally regularizes the matter content, solving one of the main obstacles to back-reaction calculations in more traditional treatments. The discreteness of area leads to modifications of the quantum vacua, eliminating the trans-Planckian modes close to the horizon, which in turn eliminates all singularities from physical quantities, like the expectation value of the stress–energy tensor. Apart from this, the Boulware, Hartle–Hawking and Unruh vacua differ little from the treatment on a classical space-time. The asymptotic modes near scri are reproduced very well. We show that the Hawking radiation can be computed, leading to an expression similar to the conventional one but with a high frequency cutoff. Since many of the conclusions concern asymptotic behavior, where the spherical mode of the field behaves in a similar way as higher multipole modes do, the results can be readily generalized to non spherically symmetric fields. (paper)
Fabrication and Characterization of Nanoenergetic Hollow Spherical Hexanitrostibene (HNS Derivatives
Directory of Open Access Journals (Sweden)
Xiong Cao
2018-05-01
Full Text Available The spherization of nanoenergetic materials is the best way to improve the sensitivity and increase loading densities and detonation properties for weapons and ammunition, but the preparation of spherical nanoenergetic materials with high regularization, uniform size and monodispersity is still a challenge. In this paper, nanoenergetic hollow spherical hexanitrostibene (HNS derivatives were fabricated via a one-pot copolymerization strategy, which is based on the reaction of HNS and piperazine in acetonitrile solution. Characterization results indicated the as-prepared reaction nanoenergetic products were HNS-derived oligomers, where a free radical copolymerization reaction process was inferred. The hollow sphere structure of the HNS derivatives was characterized by scanning electron microscopy (SEM, transmission electron microscope (TEM, and synchrotron radiation X-ray imaging technology. The properties of the nanoenergetic hollow spherical derivatives, including thermal decomposition and sensitivity are discussed in detail. Sensitivity studies showed that the nanoenergetic derivatives exhibited lower impact, friction and spark sensitivity than raw HNS. Thermogravimetric-differential scanning calorimeter (TG-DSC results showed that continuous exothermic decomposition occurred in the whole temperature range, which indicated that nanoenergetic derivatives have a unique role in thermal applications. Therefore, nanoenergetic hollow spherical HNS derivatives could provide a new way to modify the properties of certain energetic compounds and fabricate spherical nanomaterials to improve the charge configuration.
Numerical relativity in spherical coordinates with the Einstein Toolkit
Mewes, Vassilios; Zlochower, Yosef; Campanelli, Manuela; Ruchlin, Ian; Etienne, Zachariah B.; Baumgarte, Thomas W.
2018-04-01
Numerical relativity codes that do not make assumptions on spatial symmetries most commonly adopt Cartesian coordinates. While these coordinates have many attractive features, spherical coordinates are much better suited to take advantage of approximate symmetries in a number of astrophysical objects, including single stars, black holes, and accretion disks. While the appearance of coordinate singularities often spoils numerical relativity simulations in spherical coordinates, especially in the absence of any symmetry assumptions, it has recently been demonstrated that these problems can be avoided if the coordinate singularities are handled analytically. This is possible with the help of a reference-metric version of the Baumgarte-Shapiro-Shibata-Nakamura formulation together with a proper rescaling of tensorial quantities. In this paper we report on an implementation of this formalism in the Einstein Toolkit. We adapt the Einstein Toolkit infrastructure, originally designed for Cartesian coordinates, to handle spherical coordinates, by providing appropriate boundary conditions at both inner and outer boundaries. We perform numerical simulations for a disturbed Kerr black hole, extract the gravitational wave signal, and demonstrate that the noise in these signals is orders of magnitude smaller when computed on spherical grids rather than Cartesian grids. With the public release of our new Einstein Toolkit thorns, our methods for numerical relativity in spherical coordinates will become available to the entire numerical relativity community.
Preparation of spherical particles by vibrating orifice technique
Shibata, Shuichi; Tomizawa, Atsushi; Yoshikawa, Hidemi; Yano, Tetsuji; Yamane, Masayuki
2000-05-01
Preparation of micrometer-sized spherical particles containing Rhodamine 6G (R6G) has been investigated for the spherical cavity micro-laser. Using phenyl triethoxy silane (PTES) as a starting material, R6G-doped monodisperse spherical particles were prepared by the vibrating orifice technique. Processing consists of two major processes: (1) Hydrolysis and polymerization of PTES and (2) Droplet formation from PTES oligomers by vibrating orifice technique. A cylindrical liquid jet passing through the orifice of 10 and 20 micrometers in diameter breaks up into equal- sized droplets by mechanical vibration. Alcohol solvent of these droplets was evaporated during flying with carrier gas and subsequently solidified in ammonium water trap. For making smooth surface and god shaped particles, control of molecular weight of PTES oligomer was essential. R6G-doped hybrid spherical particles of 4 to 10 micrometers size of cavity structure were successfully obtained. The spherical particles were pumped by a second harmonic pulse of Q- switched Nd:YAG laser and laser emission peaks were observed at wavelengths which correspond to the resonance modes.
U.S. Environmental Protection Agency — There is an EJ Index for each environmental indicator. There are eight EJ Indexes in EJSCREEN reflecting the 8 environmental indicators. The EJ Index names are:...
U.S. Environmental Protection Agency — There is an EJ Index for each environmental indicator. There are eleven EJ Indexes in EJSCREEN reflecting the 11 environmental indicators. The EJ Index names are:...
Badkoubeh, Roya Sattarzadeh; Tavoosi, Anahita; Jabbari, Mostafa; Parsa, Amir Farhang Zand; Geraeli, Babak; Saadat, Mohammad; Larti, Farnoosh; Meysamie, Ali Pasha; Salehi, Mehrdad
2016-06-10
We performed comprehensive transmitral and pulmonary venous Doppler echocardiographic studies to devise a novel index of diastolic function. This is the first study to assess the utility of the acceleration rate (AR) of the E wave of mitral inflow as a primary diagnostic modality for assessing diastolic function. Study group consisted of 84 patients (53 + 11 years) with left ventricle (LV) diastolic dysfunction and 34 healthy people (35 ± 9 years) as control group, who were referred for clinically indicated two-dimensional transthoracic echocardiogram (TTE) during 2012 and 2013 to Imam Hospital. Normal controls were defined as patients without clinical evidence of cardiac disease and had normal TTE. LV diastolic function was determined according to standardized protocol of American Society of Echocardiography (ASE). As our new parameter, AR of E wave of mitral inflow was also measured in all patients. It was represented by the slope of the line between onset of E wave and peak of it. Correlation between AR of E wave and LV diastolic function grade was measured using the Spearman correlation coefficient. Receiver operating characteristic (ROC) curve was used to determine the sensitivity and specificity of AR of E wave in diagnosing LV diastolic dysfunction in randomly selected two-thirds of population then its derived cutoff was evaluated in rest of the population. The institutional review board of the hospital approved the study protocol. All participants gave written informed consent. This investigation was in accordance with the Declaration of Helsinki. The mean value of AR was 1010 ± 420 cm/s(2) in patients whereas the mean value for the normal controls was 701 ± 210 cm/s(2). There was a strong and graded relation between AR of E wave of mitral inflow and LV diastolic function grade (Spearman P ≤0.0001, rs =0.69). ROC curve analysis revealed that AR of E wave of mitral inflow =750 cm/s(2) predicted moderate or severe LV diastolic
Influence of initial imperfections on ultimate strength of spherical shells
Directory of Open Access Journals (Sweden)
Chang-Li Yu
2017-09-01
Full Text Available Comprehensive consideration regarding influence mechanisms of initial imperfections on ultimate strength of spherical shells is taken to satisfy requirement of deep-sea structural design. The feasibility of innovative numerical procedure that combines welding simulation and non-linear buckling analysis is verified by a good agreement to experimental and theoretical results. Spherical shells with a series of wall thicknesses to radius ratios are studied. Residual stress and deformations from welding process are investigated separately. Variant influence mechanisms are discovered. Residual stress is demonstrated to be influential to stress field and buckling behavior but not to the ultimate strength. Deformations are proved to have a significant impact on ultimate strength. When central angles are less than critical value, concave magnitudes reduce ultimate strengths linearly. However, deformations with central angles above critical value are of much greater harm. Less imperfection susceptibility is found in spherical shells with larger wall thicknesses to radius ratios.
Resonance energy transfer: The unified theory via vector spherical harmonics
Energy Technology Data Exchange (ETDEWEB)
Grinter, Roger, E-mail: r.grinter@uea.ac.uk; Jones, Garth A., E-mail: garth.jones@uea.ac.uk [School of Chemistry, University of East Anglia, Norwich NR4 7TJ (United Kingdom)
2016-08-21
In this work, we derive the well-established expression for the quantum amplitude associated with the resonance energy transfer (RET) process between a pair of molecules that are beyond wavefunction overlap. The novelty of this work is that the field of the mediating photon is described in terms of a spherical wave rather than a plane wave. The angular components of the field are constructed in terms of vector spherical harmonics while Hankel functions are used to define the radial component. This approach alleviates the problem of having to select physically correct solution from non-physical solutions, which seems to be inherent in plane wave derivations. The spherical coordinate system allows one to easily decompose the photon’s fields into longitudinal and transverse components and offers a natural way to analyse near-, intermediate-, and far-zone RET within the context of the relative orientation of the transition dipole moments for the two molecules.
Towards linearization of atmospheric radiative transfer in spherical geometry
International Nuclear Information System (INIS)
Walter, Holger H.; Landgraf, Jochen
2005-01-01
We present a general approach for the linearization of radiative transfer in a spherical planetary atmosphere. The approach is based on the forward-adjoint perturbation theory. In the first part we develop the theoretical background for a linearization of radiative transfer in spherical geometry. Using an operator formulation of radiative transfer allows one to derive the linearization principles in a universally valid notation. The application of the derived principles is demonstrated for a radiative transfer problem in simplified spherical geometry in the second part of this paper. Here, we calculate the derivatives of the radiance at the top of the atmosphere with respect to the absorption properties of a trace gas species in the case of a nadir-viewing satellite instrument
An electromagnetic spherical phased array thermonuclear fusion reactor
International Nuclear Information System (INIS)
Okress, E.C.
1983-01-01
Discussed are salient physics aspects of a microwave singly reentrant spherical periodic phased array of uniformally distributed identical coaxial radiation elements in an essentially simulated infinite array environment. The array is capable of maintaining coherence or phase control (to the limit of the order of 300 GHz) of its spherically converging electromagnetic transverse magnetic mode radiation field, for confinement (and heating) of thermonuclear plasma in steady-state or inertial thermonuclear fusion. The array also incorporates capability for coaxial directional coupler extraction of fusionpower. The radiation elements of the array are shielded against DT Thermonuclear plasma emissions (i.e., neutrons and bremsstrahlung) by either sufficiently (available) low less tangent and cooled, spherically concentric shield (e.g., Titanium oxide); or alternately by identical material dome windows mounted on each radiation element's aperture of the array. The pump microwave power required for thermonuclear fusion feasibility comprises an array of phase-locked available klystron amplifiers (comparable gyratron amplifiers remain to be developed)
Mixed-Degree Spherical Simplex-Radial Cubature Kalman Filter
Directory of Open Access Journals (Sweden)
Shiyuan Wang
2017-01-01
Full Text Available Conventional low degree spherical simplex-radial cubature Kalman filters often generate low filtering accuracy or even diverge for handling highly nonlinear systems. The high-degree Kalman filters can improve filtering accuracy at the cost of increasing computational complexity; nevertheless their stability will be influenced by the negative weights existing in the high-dimensional systems. To efficiently improve filtering accuracy and stability, a novel mixed-degree spherical simplex-radial cubature Kalman filter (MSSRCKF is proposed in this paper. The accuracy analysis shows that the true posterior mean and covariance calculated by the proposed MSSRCKF can agree accurately with the third-order moment and the second-order moment, respectively. Simulation results show that, in comparison with the conventional spherical simplex-radial cubature Kalman filters that are based on the same degrees, the proposed MSSRCKF can perform superior results from the aspects of filtering accuracy and computational complexity.
Plane-wave decomposition by spherical-convolution microphone array
Rafaely, Boaz; Park, Munhum
2004-05-01
Reverberant sound fields are widely studied, as they have a significant influence on the acoustic performance of enclosures in a variety of applications. For example, the intelligibility of speech in lecture rooms, the quality of music in auditoria, the noise level in offices, and the production of 3D sound in living rooms are all affected by the enclosed sound field. These sound fields are typically studied through frequency response measurements or statistical measures such as reverberation time, which do not provide detailed spatial information. The aim of the work presented in this seminar is the detailed analysis of reverberant sound fields. A measurement and analysis system based on acoustic theory and signal processing, designed around a spherical microphone array, is presented. Detailed analysis is achieved by decomposition of the sound field into waves, using spherical Fourier transform and spherical convolution. The presentation will include theoretical review, simulation studies, and initial experimental results.
Mechanisms of Stochastic Diffusion of Energetic Ions in Spherical Tori
Energy Technology Data Exchange (ETDEWEB)
Ya.I. Kolesnichenko; R.B. White; Yu.V. Yakovenko
2001-01-18
Stochastic diffusion of the energetic ions in spherical tori is considered. The following issues are addressed: (I) Goldston-White-Boozer diffusion in a rippled field; (ii) cyclotron-resonance-induced diffusion caused by the ripple; (iii) effects of non-conservation of the magnetic moment in an axisymmetric field. It is found that the stochastic diffusion in spherical tori with a weak magnetic field has a number of peculiarities in comparison with conventional tokamaks; in particular, it is characterized by an increased role of mechanisms associated with non-conservation of the particle magnetic moment. It is concluded that in current experiments on National Spherical Torus eXperiment (NSTX) the stochastic diffusion does not have a considerable influence on the confinement of energetic ions.
Classical properties and semiclassical quantization of a spherical nuclear potential
International Nuclear Information System (INIS)
Carbonell, J.; Brut, F.; Arvieu, R.; Touchard, J.
1984-03-01
The geometrical properties of the classical energy-action surface are studied for a nuclear Woods-Saxon-like spherical potential, in connection with the E.B.K. semiclassical method of quantization. Comparisons are made with other well known cases: the spherical harmonic oscillator and the spherical billiard. The shift of single particle energies from A = 208 to A = 16 is calculated by a simple method inspired by the Erhenfest adiabatic invariants. Semiclassical results are then compared with exact Schroedinger energies. It is seen that the most significant features of the single particle spectrum are explained by local properties of the energy action surface (curvature, slope) and by their evolution with the particle number
Limwong, Vasinee; Sutanthavibul, Narueporn; Kulvanich, Poj
2004-03-12
Composite particles of rice starch (RS) and microcrystalline cellulose were fabricated by spray-drying technique to be used as a directly compressible excipient. Two size fractions of microcrystalline cellulose, sieved (MCS) and jet milled (MCJ), having volumetric mean diameter (D50) of 13.61 and 40.51 microm, respectively, were used to form composite particles with RS in various mixing ratios. The composite particles produced were evaluated for their powder and compression properties. Although an increase in the microcrystalline cellulose proportion imparted greater compressibility of the composite particles, the shape of the particles was typically less spherical with rougher surface resulting in a decrease in the degree of flowability. Compressibility of composite particles made from different size fractions of microcrystalline cellulose was not different; however, using MCJ, which had a particle size range close to the size of RS (D50 = 13.57 microm), provided more spherical particles than using MCS. Spherical composite particles between RS and MCJ in the ratio of 7:3 (RS-MCJ-73) were then evaluated for powder properties and compressibility in comparison with some marketed directly compressible diluents. Compressibility of RS-MCJ-73 was greater than commercial spray-dried RS (Eratab), coprocessed lactose and microcrystalline cellulose (Cellactose), and agglomerated lactose (Tablettose), but, as expected, lower than microcrystalline cellulose (Vivapur 101). Flowability index of RS-MCJ-73 appeared to be slightly lower than Eratab but higher than Vivapur 101, Cellactose, and Tablettose. Tablets of RS-MCJ-73 exhibited low friability and good self-disintegrating property. It was concluded that these developed composite particles could be introduced as a new coprocessed direct compression excipient.
Spherical null geodesics of rotating Kerr black holes
International Nuclear Information System (INIS)
Hod, Shahar
2013-01-01
The non-equatorial spherical null geodesics of rotating Kerr black holes are studied analytically. Unlike the extensively studied equatorial circular orbits whose radii are known analytically, no closed-form formula exists in the literature for the radii of generic (non-equatorial) spherical geodesics. We provide here an approximate formula for the radii r ph (a/M;cosi) of these spherical null geodesics, where a/M is the dimensionless angular momentum of the black hole and cos i is an effective inclination angle (with respect to the black-hole equatorial plane) of the orbit. It is well-known that the equatorial circular geodesics of the Kerr spacetime (the prograde and the retrograde orbits with cosi=±1) are characterized by a monotonic dependence of their radii r ph (a/M;cosi=±1) on the dimensionless spin-parameter a/M of the black hole. We use here our novel analytical formula to reveal that this well-known property of the equatorial circular geodesics is actually not a generic property of the Kerr spacetime. In particular, we find that counter-rotating spherical null orbits in the range (3√(3)−√(59))/4≲cosi ph (a/M;cosi=const) on the dimensionless rotation-parameter a/M of the black hole. Furthermore, it is shown that spherical photon orbits of rapidly-rotating black holes are characterized by a critical inclination angle, cosi=√(4/7), above which the coordinate radii of the orbits approach the black-hole radius in the extremal limit. We prove that this critical inclination angle signals a transition in the physical properties of the spherical null geodesics: in particular, it separates orbits which are characterized by finite proper distances to the black-hole horizon from orbits which are characterized by infinite proper distances to the horizon.
[Depth of focus in spherical and aspheric intraocular lenses].
Nan, Li; Tang, Xin; Liu, Yong-ji
2012-02-01
To investigate depth of focus (DOF) in spherical and aspheric IOL eye models. Computer numerical simulation experiment was used. IOL eye model based on Liou-Brennan eye model was constructed by using ZEMAX optical design software. Different IOL were implanted in this eye model. Monochromatic through focus modulation transfer function (MTF) curves were computed. Pupil and aspheric designs' effect on DOF were analyzed. DOF of eye model increased with pupil shrinkage in 550 nm monochromatic light (FY60AD 1.20 D at 6 mm pupil, 1.35 D at 5 mm pupil, 1.70 D at 4 mm pupil, 2.46 D at 3 mm pupil; YA60BBR 1.24 D at 6 mm pupil, 1.48 D at 5 mm pupil, 1.80 D at 4 mm pupil, 2.50 D at 3 mm pupil). MTF in spherical IOL eye model was higher with minus defocus, this trend was obvious at larger pupil. MTF of aspheric IOL eyes were higher than spherical IOL eyes when well focused at 5 mm pupil, while the DOF was lower in aspheric IOL with negative spherical aberration (Tecnis Z9000 1.31 D, FY60AD 1.35 D, CeeOn911 1.55 D, YA60BBR 1.48 D). DOF decreased less in aspheric IOL with zero spherical aberration (LI61AO 1.42 D). DOF in IOL eye model was higher at smaller pupil. When the pupil was large, well focused aspheric IOL improved optical quality compared with spherical IOL, while DOF and the tolerance to defocus in aspheric IOL were partially lost; this phenomenon was obvious with minus defocus.
A Robust Solution of the Spherical Burmester Problem
DEFF Research Database (Denmark)
Angeles, Jorge; Bai, Shaoping
2010-01-01
The problem of spherical four-bar linkage synthesis is revisited in this paper. The work is aimed at developing a robust synthesis method by taking into account both the formulation and the solution method. In addition, the synthesis of linkages with spherical prismatic joints is considered...... by treating them as a special case of the linkages under study. A two-step synthesis method is developed, which sequentially deals with equation-solving by a semigraphical approach and branching-detection. Examples are included to demonstrate the proposed method....
Positivity of the spherically averaged atomic one-electron density
DEFF Research Database (Denmark)
Fournais, Søren; Hoffmann-Ostenhof, Maria; Hoffmann-Ostenhof, Thomas
2008-01-01
We investigate the positivity of the spherically averaged atomic one-electron density . For a which stems from a physical ground state we prove that for r ≥ 0. This article may be reproduced in its entirety for non-commercial purposes.......We investigate the positivity of the spherically averaged atomic one-electron density . For a which stems from a physical ground state we prove that for r ≥ 0. This article may be reproduced in its entirety for non-commercial purposes....
Current drive experiments on the HIT-II spherical torus
International Nuclear Information System (INIS)
Jarboe, T.R.; Raman, R.; Nelson, B.A.; Holcomb, C.T.; McCollam, K.J.; Sieck, P.E.
1999-01-01
This paper describes the following new achievements from the Helicity Injected Torus (HIT) program: a) formation and sustainment of a toroidal magnetic equilibrium using coaxial helicity injection (CHI) in a conducting shell that has an L/R time much shorter than the pulse length; b) static formation of a spherical torus with plasma current over 180 kA using a transformer and feedback controlled equilibrium coils; and c) production of a current increase in a transformer produced spherical torus using CHI. (author)
Current drive experiments on the HIT-II spherical torus
International Nuclear Information System (INIS)
Jarboe, T.; Raman, R.; Nelson, B.; Holcomb, C.T.; McCollam, K.J.; Sieck, P.E.
2001-01-01
This paper describes the following new achievements from the Helicity Injected Torus (HIT) program: a) formation and sustainment of a toroidal magnetic equilibrium using coaxial helicity injection (CHI) in a conducting shell that has an L/R time much shorter than the pulse length; b) static formation of a spherical torus with plasma current over 180 kA using a transformer and feedback controlled equilibrium coils; and c) production of a current increase in a transformer produced spherical torus using CHI. (author)
Spherical powder for retaining thermosetting acrylic resin veneers.
Tanaka, T; Atsuta, M; Uchiyama, Y; Nakabayashi, N; Masuhara, E
1978-03-01
1. Nine different sizes of spherical powder were prepared, and their effectiveness as retentive devices was evaluated against those available commercially. 2. Smaller-diameter spherical powder (No. 5) gave the best results of all retaining devices tested. 3. The physical properties of the resins play an important role in the retentive strength with No. 5 retention beads. The retentive strength was reduced when brittle resin was used. 4. The retentive strength of the resin veneer was greatly affected by the angle of stress at the incisal resin. The retentive strength increased as the angle between the longitudinal axis of the specimen and the direction of stress decreased.
Photodetachment of H− near a Hard Spherical Surface
International Nuclear Information System (INIS)
Haneef, M.; Rahman, A.; Ahmad, Iftikhar; Afaq, A.
2012-01-01
The photodetachment of a hydrogen negative ion (H − ) near a hard spherical surface is investigated by using the theoretical imaging method. The surface is oriented in such a fashion that the laser polarization direction is perpendicular to the principal axis of the spherical surface. Analytical expressions are derived for the detached-electron flux and photodetachment cross section. Strong interference patterns are observed in the detached-electron flux, while no visible oscillations are found in the photodetachment cross section. (atomic and molecular physics)
Preserving spherical symmetry in axisymmetric coordinates for diffusion problems
International Nuclear Information System (INIS)
Brunner, T. A.; Kolev, T. V.; Bailey, T. S.; Till, A. T.
2013-01-01
Persevering symmetric solutions, even in the under-converged limit, is important to the robustness of production simulation codes. We explore the symmetry preservation in both a continuous nodal and a mixed finite element method. In their standard formulation, neither method preserves spherical solution symmetry in axisymmetric (RZ) coordinates. We propose two methods, one for each family of finite elements, that recover spherical symmetry for low-order finite elements on linear or curvilinear meshes. This is a first step toward understanding achieving symmetry for higher-order elements. (authors)
Strongly Localized Image States of Spherical Graphitic Particles
Directory of Open Access Journals (Sweden)
Godfrey Gumbs
2014-01-01
Full Text Available We investigate the localization of charged particles by the image potential of spherical shells, such as fullerene buckyballs. These spherical image states exist within surface potentials formed by the competition between the attractive image potential and the repulsive centripetal force arising from the angular motion. The image potential has a power law rather than a logarithmic behavior. This leads to fundamental differences in the nature of the effective potential for the two geometries. Our calculations have shown that the captured charge is more strongly localized closest to the surface for fullerenes than for cylindrical nanotube.
Neutron production in a spherical phantom aboard ISS
International Nuclear Information System (INIS)
Tasbaz, A.; Machrafi, R.
2012-01-01
As part of an ongoing research program on radiation monitoring on International Space Station (ISS) that was established to analyze the radiation exposure levels onboard the ISS using different radiation instruments and a spherical phantom to simulate human body. Monte Carlo transport code was used to simulate the interaction of high energy protons and neutrons with the spherical phantom currently onboard ISS. The phantom has been exposed to individual proton energies and to a spectrum of neutrons. The internal to external neutron flux ratio was calculated and compared to the experimental data, recently, measured on the ISS. (author)
Spherical and cylindrical particle resonator as a cloak system
Minin, I. V.; Minin, O. V.; Eremeev, A. I.; Tseplyaev, I. S.
2018-05-01
The concept of dielectric spherical or cylindrical particle in resonant mode as a cloak system is offered. In fundamental modes (modes with the smallest volume correspond to |m| = l, and s = 1) the field is concentrated mostly in the equatorial plane and at the surface of the sphere. Thus under resonance modes, such perturbation due to cuboid particle inserted in the spherical or cylindrical particle has almost no effect on the field forming resonance regardless of the value of internal particle material (defect) as long as this material does not cover the region where resonance takes place.
Fabrication technology of spherical fuel element for HTR-10
International Nuclear Information System (INIS)
He Jun; Zou Yanwen; Liang Tongxiang; Qiu Xueliang
2002-01-01
R and D on the fabrication technology of the spherical fuel elements for the 10 MW HTR Test Module (HTR-10) began from 1986. Cold quasi-isostatic molding with a silicon rubber die is used for manufacturing the spherical fuel elements.The fabrication technology and the graphite matrix materials were investigated and optimized. Twenty five batches of fuel elements, about 11000 of the fuel elements, have been produced. The cold properties of the graphite matrix materials satisfied the design specifications. The mean free uranium fraction of 25 batches was 5 x 10 -5
Spectroscopy and probe diagnostics of dc spherical glow discharge
International Nuclear Information System (INIS)
Zhovtyansky, V.A.; Nazarenko, V.G.; Syrotyuk, R.P.
2016-01-01
Probe and spectroscopic investigations of a spherical glow discharge (GD) were done in nitrogen and argon plasma. There were obtained the distributions of electron temperature and electron density in a discharge gap as well as plasma potential distribution. These results were compared with theoretical ones and the conclusion about their convergence was done in the present study. Particular attention was paid to the anode processes role in the formation of self-organized structure in a spherical glow discharge. It was shown the necessity of taking into account the possibility of the anode potential drop forming in this discharge region
Buckling strength of spherical shells under combined loads
International Nuclear Information System (INIS)
Nagashima, H.; Kokubo, K.; Takayanagi, M.; Hayasaka, Y.; Kume, T.; Nagata, T.
1995-01-01
Many studies on buckling of cylindrical shells have been conducted, and many buckling evaluation equations have been proposed for actual plant designs; however, buckling of spherical shells under combined horizontal and vertical loads cannot be evaluated due to insufficient data. There is a particular lack of buckling data for spherical shells under lateral loads. To establish a method for estimating the buckling strength of spherical shells, we investigate the interactions between horizontal and vertical (compressive tensile) loads by conducting buckling tests. Applying several combinations of these loads in tests and using computer linear analysis, we obtain interaction curves. This study reports on the buckling tests conducted using spherical shell 1120 mm in dia., 0.7 mm thick and 696 mm high, which are shaped individually by press-forming and finally joined together by four meridional welds, using a specially made jig. Initial imperfections before testing and local deformations after each loading increment during testing are measured with special measuring equipment, and the interaction curve of horizontal and vertical loads and effect of imperfection on the buckling strength of spherical shells are obtained. Nonlinear FEM programs are developed using an 8-node isoparametric shell element and a four-node quadrilateral element of C 0 type with reduced integration based upon a Mindlin-Reissner theory which includes transverse shear. Actual initial imperfections are generally in irregular patterns. Thus, there may be several definitions of the equivalent magnitudes of initial imperfections related to buckling loads. Equivalent magnitudes have no practical meaning unless they can be obtained easily not only for small structures such as test shells but also for large actual structures. In the present study, we define the equivalent magnitude of initial imperfections as the maximum local ruggedness measured radially from a circular temperature having a radius equal
Flat synchronizations in spherically symmetric space-times
International Nuclear Information System (INIS)
Herrero, Alicia; Morales-Lladosa, Juan Antonio
2010-01-01
It is well known that the Schwarzschild space-time admits a spacelike slicing by flat instants and that the metric is regular at the horizon in the associated adapted coordinates (Painleve-Gullstrand metric form). We consider this type of flat slicings in an arbitrary spherically symmetric space-time. The condition ensuring its existence is analyzed, and then, we prove that, for any spherically symmetric flat slicing, the densities of the Weinberg momenta vanish. Finally, we deduce the Schwarzschild solution in the extended Painleve-Gullstrand-LemaItre metric form by considering the coordinate decomposition of the vacuum Einstein equations with respect to a flat spacelike slicing.
Static solutions with spherical symmetry in f(T) theories
International Nuclear Information System (INIS)
Wang Tower
2011-01-01
The spherically symmetric static solutions are searched for in some f(T) models of gravity theory with a Maxwell term. To do this, we demonstrate that reconstructing the Lagrangian of f(T) theories is sensitive to the choice of frame, and then we introduce a particular frame based on the conformally Cartesian coordinates. In this particular frame, the existence conditions of various solutions are presented. Our results imply that only a limited class of f(T) models can be solved in this frame. For more general models, the search for spherically symmetric static solutions is still an open and challenging problem, hopefully solvable in other frames.
Full-angle tomographic phase microscopy of flowing quasi-spherical cells.
Villone, Massimiliano M; Memmolo, Pasquale; Merola, Francesco; Mugnano, Martina; Miccio, Lisa; Maffettone, Pier Luca; Ferraro, Pietro
2017-12-19
We report a reliable full-angle tomographic phase microscopy (FA-TPM) method for flowing quasi-spherical cells along microfluidic channels. This method lies in a completely passive optical system, i.e. mechanical scanning or multi-direction probing of the sample is avoided. It exploits the engineered rolling of cells while they are flowing along a microfluidic channel. Here we demonstrate significant progress with respect to the state of the art of in-flow TPM by showing a general extension to cells having almost spherical shapes while they are flowing in suspension. In fact, the adopted strategy allows the accurate retrieval of rotation angles through a theoretical model of the cells' rotation in a dynamic microfluidic flow by matching it with phase-contrast images resulting from holographic reconstructions. So far, the proposed method is the first and the only one that permits to get in-flow TPM by probing the cells with full-angle, achieving accurate 3D refractive index mapping and the simplest optical setup, simultaneously. Proof of concept experiments were performed successfully on human breast adenocarcinoma MCF-7 cells, opening the way for the full characterization of circulating tumor cells (CTCs) in the new paradigm of liquid biopsy.
Energy Transfer Using Gradient Index Metamaterial
Directory of Open Access Journals (Sweden)
Boopalan Ganapathy
2018-01-01
Full Text Available The gradient refractive index structure in this paper is used to increase the quantum of energy transfer. This is done by improving the directive gain of the pyramidal horn antenna at a frequency of 10 GHz. A three-dimensional array of closed square rings is placed in front of the horn antenna aperture to form a gradient refractive index structure. This structure increases the directive gain by 1.6 dB as compared to that of the conventional horn antenna. The structure nearly doubles the wireless power transfer quantum between the transmitter and the receiver when placed at both ends. The increase in the directivity is achieved by converting the spherical wave emanating from the horn to a plane wave once it passes through the structure. This transformation is realized by the gradient refractive index structure being placed perpendicular to the direction of propagation. The gradient refractive index is constructed by changing the dimensions of a closed square ring placed in the unit cell of the array. The change in the refractive index gives rise to an improvement of the half power beam width and side lobe level compared to that of the normal horn. The design and simulation were done using CST Studio software.
Directory of Open Access Journals (Sweden)
G. Göransson
2013-07-01
Full Text Available The turbidity variation in time and space is investigated in the downstream stretch of the river Göta Älv in Sweden. The river is heavily regulated and carries the discharge from the largest fresh water lake in Sweden, Lake Vänern, to the outflow point in Göteborg Harbour on the Swedish west coast. The river is an important waterway and serves as a fresh-water supply for 700 000 users. Turbidity is utilised as a water quality indicator to ensure sufficient quality of the intake water to the treatment plant. The overall objective of the study was to investigate the influence of rainfall, surface runoff, and river water flow on the temporal and spatial variability of the turbidity in the regulated river system by employing statistical analysis of an extensive data set. A six year long time series of daily mean values on precipitation, discharge, and turbidity from six stations along the river were examined primarily through linear correlation and regression analysis, combined with nonparametric tests and analysis of variance. The analyses were performed on annual, monthly, and daily bases, establishing temporal patterns and dependences, including; seasonal changes, impacts from extreme events, influences from tributaries, and the spatial variation along the river. The results showed that there is no simple relationship between discharge, precipitation, and turbidity, mainly due to the complexity of the runoff process, the regulation of the river, and the effects of Lake Vänern and its large catchment area. For the river Göta Älv, significant, positive correlations between turbidity, discharge, and precipitation could only be found during periods with high flow combined with heavy rainfall. Local precipitation does not seem to have any significant impact on the discharge in the main river, which is primarily governed by precipitation at catchment scale. The discharge from Lake Vänern determines the base level for the turbidity in the river
International Nuclear Information System (INIS)
Sandoval V, S.; Mendoza R, M. E.; Tijerina S, F.; Garcia C, T.
2016-09-01
A nuclear power plant is operated at all times within the design criteria of structures, systems and components, and according to the operation technical specifications. For different areas of work of a nuclear power plant is necessary to carry out practices in which is useful to have the prediction of the thermo-hydraulic and radiological progression of scenarios that imply exceeding that design bases, even reaching the damage of the fuel in different degree. During the exercises and drills of the External Plan of Emergency Response, the projection of doses is done to exercise the different tasks of the plan. To make the projection of doses is required to have the radiological source term of the scenario on which is practiced. Because of this, was identified the convenience of having a catalog of scenarios for which the radiological source term was calculated. In 2004, a first version of the catalog was produced for a power of 2027 MW, and in 2011 the catalog was updated for extended power conditions, 2317 MW. Both versions were made using the severe accident simulator MAAP-3B. That catalog consists of a form and an optical storage device. The form contains tables and figures in which the characteristics of the scenario to be practiced are searched and the electronic files of the corresponding radiological source term are located in the storage device. Due to the recent development of the graphical console for analysis of severe accidents, visualization of OEs, NAEs and calculation of the source term for the nuclear power plant of Laguna Verde (NPP-LV) CoGrAAS, the catalog printed was replaced by an electronic catalog for the CoGrAAS. The new catalog retains the philosophy of the previous catalog, constituted by a wide collection of scenarios that involve different circumstances and phenomena, that can be used to practice different tasks during training exercises or simulacrums, and combined with the following advantages: the scenario selection is made from an
Radiation quality factor of spherical antennas with material cores
DEFF Research Database (Denmark)
Hansen, Troels Vejle; Kim, Oleksiy S.; Breinbjerg, Olav
2011-01-01
This paper gives a description of the radiation quality factor and resonances of spherical antennas with material cores. Conditions for cavity and radiating resonances are given, and a theoretical description of the radiation quality factor, as well as simple expressions describing the relative...
Rayleigh-Taylor instability in multi-structured spherical targets
International Nuclear Information System (INIS)
Gupta, N.K.; Lawande, S.V.
1986-01-01
An eigenvalue equation for the exponential growth rate of the Rayleigh-Taylor instability is derived in spherical geometry. The free surface and jump boundary conditions are obtained from the eigenvalue equation. The eigenvalue equation is solved in the cases where the initial fluid density profile has a step function or exponential variation in space and analytical formulae for growth rate of the instability are obtained. The solutions for the step function are generalized for any number N of spherical zones forming an arbitrary fluid density profile. The results of the numerical calculations for N spherical zones are compared with the exact analytical results for exponential fluid density profile with N=10 and a good agreement is observed. The formalism is further used to study the effects of density gradients on Rayleigh-Taylor instability in spherical geometry. Also analytical formulae are presented for a particular case of N=3 and shell targets. The formalism developed here can be used to study the growth of the instability in present day multi-structured shell targets. (author)
Linearized vector radiative transfer model MCC++ for a spherical atmosphere
International Nuclear Information System (INIS)
Postylyakov, O.V.
2004-01-01
Application of radiative transfer models has shown that optical remote sensing requires extra characteristics of radiance field in addition to the radiance intensity itself. Simulation of spectral measurements, analysis of retrieval errors and development of retrieval algorithms are in need of derivatives of radiance with respect to atmospheric constituents under investigation. The presented vector spherical radiative transfer model MCC++ was linearized, which allows the calculation of derivatives of all elements of the Stokes vector with respect to the volume absorption coefficient simultaneously with radiance calculation. The model MCC++ employs Monte Carlo algorithm for radiative transfer simulation and takes into account aerosol and molecular scattering, gas and aerosol absorption, and Lambertian surface albedo. The model treats a spherically symmetrical atmosphere. Relation of the estimated derivatives with other forms of radiance derivatives: the weighting functions used in gas retrieval and the air mass factors used in the DOAS retrieval algorithms, is obtained. Validation of the model against other radiative models is overviewed. The computing time of the intensity for the MCC++ model is about that for radiative models treating sphericity of the atmosphere approximately and is significantly shorter than that for the full spherical models used in the comparisons. The simultaneous calculation of all derivatives (i.e. with respect to absorption in all model atmosphere layers) and the intensity is only 1.2-2 times longer than the calculation of the intensity only
Compact fusion energy based on the spherical tokamak
Sykes, A.; Costley, A. E.; Windsor, C. G.; Asunta, O.; Brittles, G.; Buxton, P.; Chuyanov, V.; Connor, J. W.; Gryaznevich, M. P.; Huang, B.; Hugill, J.; Kukushkin, A.; Kingham, D.; Langtry, A. V.; McNamara, S.; Morgan, J. G.; Noonan, P.; Ross, J. S. H.; Shevchenko, V.; Slade, R.; Smith, G.
2018-01-01
Tokamak Energy Ltd, UK, is developing spherical tokamaks using high temperature superconductor magnets as a possible route to fusion power using relatively small devices. We present an overview of the development programme including details of the enabling technologies, the key modelling methods and results, and the remaining challenges on the path to compact fusion.
Spherical Model Integrating Academic Competence with Social Adjustment and Psychopathology.
Schaefer, Earl S.; And Others
This study replicates and elaborates a three-dimensional, spherical model that integrates research findings concerning social and emotional behavior, psychopathology, and academic competence. Kindergarten teachers completed an extensive set of rating scales on 100 children, including the Classroom Behavior Inventory and the Child Adaptive Behavior…
The volume of fluid method in spherical coordinates
Janse, A.M.C.; Janse, A.M.C.; Dijk, P.E.; Kuipers, J.A.M.
2000-01-01
The volume of fluid (VOF) method is a numerical technique to track the developing free surfaces of liquids in motion. This method can, for example, be applied to compute the liquid flow patterns in a rotating cone reactor. For this application a spherical coordinate system is most suited. The novel
An approximate solution for spherical and cylindrical piston problem
Indian Academy of Sciences (India)
the growth and decay of shock strengths for spherical and cylindrical pistons starting from a non-zero ... conditions at an appropriate level, a new theory of shock dynamics (NTSD) has been proposed (Ravindran and ..... sive, its packing density etc. which are not included in our mathematical formulation, it may explain the ...
Spherical anharmonic oscillator in self-similar approximation
International Nuclear Information System (INIS)
Yukalova, E.P.; Yukalov, V.I.
1992-01-01
The method of self-similar approximation is applied here for calculating the eigenvalues of the three-dimensional spherical anharmonic oscillator. The advantage of this method is in its simplicity and high accuracy. The comparison with other known analytical methods proves that this method is more simple and accurate. 25 refs
Dynamics and control of vibratory gyroscopes with special spherical symmetry
CSIR Research Space (South Africa)
Shatalov, M
2006-01-01
Full Text Available It was shown in 1985 by Acad. V. Zhuravlev that the angular rate of a pure vibrating mode excited in a vibratory gyroscope with spherical symmetry is proportional to an inertial angular rate of the gyroscope. The effect is three dimensional...
Exact solution of the neutron transport equation in spherical geometry
Energy Technology Data Exchange (ETDEWEB)
Anli, Fikret; Akkurt, Abdullah; Yildirim, Hueseyin; Ates, Kemal [Kahramanmaras Suetcue Imam Univ. (Turkey). Faculty of Sciences and Letters
2017-03-15
Solution of the neutron transport equation in one dimensional slab geometry construct a basis for the solution of neutron transport equation in a curvilinear geometry. Therefore, in this work, we attempt to derive an exact analytical benchmark solution for both neutron transport equations in slab and spherical medium by using P{sub N} approximation which is widely used in neutron transport theory.
Optical properties of spherical and oblate spheroidal gold shell colloids
Penninkhof, J.J.; Moroz, A.; van Blaaderen, A.; Polman, A.
2008-01-01
The surface plasmon modes of spherical and oblate spheroidal core−shell colloids composed of a 312 nm diameter silica core and a 20 nm thick Au shell are investigated. Large arrays of uniaxially aligned core−shell colloids with size aspect ratios ranging from 1.0 to 1.7 are fabricated using a novel
Inversion of the Earth spherical albedo from radiation-pressure
Wilkman, Olli; Herranen, Joonas; Näränen, Jyri; Virtanen, Jenni; Koivula, Hannu; Poutanen, Markku; Penttilä, Antti; Gritsevich, Maria; Muinonen, Karri
2017-04-01
We are studying the retrieval of the spherical albedo and net radiation of the Earth from the perturbations caused by the planet's radiation on the dynamics of its satellites. The spherical or Bond albedo gives the ratio of the fluxes incident on and scattered by the planet. The net radiation represents the net heat input into the planet's climate system and drives changes in its atmospheric, surface, and ocean temperatures. The ultimate aim of the study is inverting the problem and estimating the Earth albedo based on observations of satellites, simultaneously improving the space-geodetic positioning accuracy. Here we investigate the effect of the spherical albedo on satellite orbits with the help of a simplified model. We simulate the propagation of satellite orbits using a new simulation software. The simulation contains the main perturbing forces on medium and high Earth orbits, used by, e.g., navigation satellites, including the radiation pressure of reflected sunlight from the Earth. An arbitrary satellite shape model can be used, and the rotation of the satellite is modeled. In this first study, we use a box-wing satellite model with a simple surface BRDF. We also assume a diffusely reflecting Earth with a single global albedo value. We vary the Earth albedo and search for systematic effects on different orbits. Thereafter, we estimate the dependence of the albedo accuracy on the satellite positioning and timing data available. We show that the inversion of the spherical albedo with reasonable accuracy is feasible from the current space-geodetic measurements.
Spherical torus (ST) concept and its reactor implications
International Nuclear Information System (INIS)
Peng, Y.K.M.; Lazarus, E.A.; Miller, R.L.; Carreras, B.A.; Hogan, J.T.; Krakowski, R.A.; Seed, T.J.; Zubrin, R.M.; Schnurr, N.M.
1986-01-01
A brief description of the spherical torus design is given. The design concept includes resistive demountable toroidal field coils, poloidal divertor for impurity control, oscillating-field current maintenance, RF initiation and ramp-up of the plasma current, and flowing liquid-metal breeding blanket. 4 refs., 6 figs
Coupled Person Orientation Estimation and Appearance Modeling using Spherical Harmonics
Liem, M.C.; Gavrila, D.M.
2014-01-01
We present a novel approach for the estimation of a person's overall body orientation, 3D shape and texture, from overlapping cameras. A distinguishing aspect of our approach is the use of spherical harmonics for 3D shape- and texture-representation; it offers a compact, low-dimensional
Novel spherical hohlraum with cylindrical laser entrance holes and shields
Energy Technology Data Exchange (ETDEWEB)
Lan, Ke [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Zheng, Wudi [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)
2014-09-15
Our recent works [K. Lan et al., Phys. Plasmas 21, 010704 (2014); K. Lan et al., Phys. Plasmas 21, 052704 (2014)] have shown that the octahedral spherical hohlraums are superior to the cylindrical hohlraums in both higher symmetry during the capsule implosion and lower backscatter without supplementary technology. However, both the coupling efficiency from the drive laser energy to the capsule and the capsule symmetry decrease remarkably when larger laser entrance holes (LEHs) are used. In addition, the laser beams injected at angles > 45° transport close to the hohlraum wall, thus the wall blowoff causes the LEH to close faster and results in strong laser plasma interactions inside the spherical hohlraums. In this letter, we propose a novel octahedral hohlraum with LEH shields and cylindrical LEHs to alleviate these problems. From our theoretical study, with the LEH shields, the laser coupling efficiency is significantly increased and the capsule symmetry is remarkably improved in the spherical hohlraums. The cylindrical LEHs take advantage of the cylindrical hohlraum near the LEH and mitigate the influence of the blowoff on laser transport inside a spherical hohlraum. The cylindrical LEHs can also be applied to the rugby and elliptical hohlraums.
Novel spherical hohlraum with cylindrical laser entrance holes and shields
International Nuclear Information System (INIS)
Lan, Ke; Zheng, Wudi
2014-01-01
Our recent works [K. Lan et al., Phys. Plasmas 21, 010704 (2014); K. Lan et al., Phys. Plasmas 21, 052704 (2014)] have shown that the octahedral spherical hohlraums are superior to the cylindrical hohlraums in both higher symmetry during the capsule implosion and lower backscatter without supplementary technology. However, both the coupling efficiency from the drive laser energy to the capsule and the capsule symmetry decrease remarkably when larger laser entrance holes (LEHs) are used. In addition, the laser beams injected at angles > 45° transport close to the hohlraum wall, thus the wall blowoff causes the LEH to close faster and results in strong laser plasma interactions inside the spherical hohlraums. In this letter, we propose a novel octahedral hohlraum with LEH shields and cylindrical LEHs to alleviate these problems. From our theoretical study, with the LEH shields, the laser coupling efficiency is significantly increased and the capsule symmetry is remarkably improved in the spherical hohlraums. The cylindrical LEHs take advantage of the cylindrical hohlraum near the LEH and mitigate the influence of the blowoff on laser transport inside a spherical hohlraum. The cylindrical LEHs can also be applied to the rugby and elliptical hohlraums
development of a hydrothermal method to synthesize spherical znse
African Journals Online (AJOL)
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nanoparticles have a zinc blend structure and in a spherical form with ... optoelectronic devices such as blue-green laser diodes and turnable mid-IR ... Solvothermal methods have also been developed for the synthesis of ZnSe and CdSe. The.
Gravitational field of spherical domain wall in higher dimension
Indian Academy of Sciences (India)
An exact solution of Einstein's equations is found describing the gravitational ﬁeld of a spherical domain wall with nonvanishing stress component in the direction perpendicular to the plane of the wall. Also we have studied the motion of test particle around the domain wall.
WAVEMOTH-FAST SPHERICAL HARMONIC TRANSFORMS BY BUTTERFLY MATRIX COMPRESSION
International Nuclear Information System (INIS)
Seljebotn, D. S.
2012-01-01
We present Wavemoth, an experimental open source code for computing scalar spherical harmonic transforms (SHTs). Such transforms are ubiquitous in astronomical data analysis. Our code performs substantially better than existing publicly available codes owing to improvements on two fronts. First, the computational core is made more efficient by using small amounts of pre-computed data, as well as paying attention to CPU instruction pipelining and cache usage. Second, Wavemoth makes use of a fast and numerically stable algorithm based on compressing a set of linear operators in a pre-computation step. The resulting SHT scales as O(L 2 log 2 L) for the resolution range of practical interest, where L denotes the spherical harmonic truncation degree. For low- and medium-range resolutions, Wavemoth tends to be twice as fast as libpsht, which is the current state-of-the-art implementation for the HEALPix grid. At the resolution of the Planck experiment, L ∼ 4000, Wavemoth is between three and six times faster than libpsht, depending on the computer architecture and the required precision. Because of the experimental nature of the project, only spherical harmonic synthesis is currently supported, although adding support for spherical harmonic analysis should be trivial.
Non-spherical granular flows down inclined chutes
Hidalgo, R.C.; Rubio-Largo, S.M.; Alonso-Marroquin, F.; Weinhart, T.
2017-01-01
In this work, we numerically examine the steady-state granular flow of 3D non-spherical particles down an inclined plane. We use a hybrid CPU/GPU implementation of the discrete element method of nonspherical elongated particles. Thus, a systematic study of the system response is performed varying
Vibrational collective model for spheric even-even nuclei
International Nuclear Information System (INIS)
Cruz, M.T.F. da.
1985-01-01
A review is made on the evidences of collective motions in spherical even-even nuclei. The several multipole transitions occuring in such a nuclei are discussed. Some hypothesis which are necessary in order to build-up the model are presented. (L.C.) [pt
Avian influenza a virus budding morphology: spherical or filamentous?
Most strains of influenza A virus (IAV) can produce long (µm length) filamentous virus particles as well as ~100 nm diameter spherical virions. The function of the filamentous particles is unclear but is hypothesized to facilitate transmission within or from the respiratory tract. In mammalian IAVs,...
Transient neutrons flux behaviour in a spherical reactor core
International Nuclear Information System (INIS)
Souza, A.W.A. de.
1978-11-01
This work studies the transient neutron flux in a fast reactor of spherical geometry. The burning of U 235 nuclei is equated and two kinds of reflector were studied. The numeric solutions are then compared with the results for those reflectors. (author) [pt
FFT-based high-performance spherical harmonic transformation
Czech Academy of Sciences Publication Activity Database
Gruber, Ch.; Novák, P.; Sebera, Josef
2011-01-01
Roč. 55, č. 3 (2011), s. 489-500 ISSN 0039-3169 Institutional research plan: CEZ:AV0Z10030501 Keywords : 2-D Fourier expansion * geopotential * spherical harmonics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.700, year: 2011
Spherical-wave expansions of piston-radiator fields.
Wittmann, R C; Yaghjian, A D
1991-09-01
Simple spherical-wave expansions of the continuous-wave fields of a circular piston radiator in a rigid baffle are derived. These expansions are valid throughout the illuminated half-space and are useful for efficient numerical computation in the near-field region. Multipole coefficients are given by closed-form expressions which can be evaluated recursively.
Effects of Brinkman number on thermal-driven convective spherical ...
African Journals Online (AJOL)
Michael Horsfall
KEYWORDS: Magnetic field generation, Thermal-driven convection, Brinkman number, Dynamo action, Fluid outer core ... The problem considers conducting fluid motion in a rapidly rotating spherical shell. The ... is, that the energy lost by the electric currents must be ... which are sources of free electrons and basically due.
Spherical wave particle velocities in geologic materials from laboratory experiments
International Nuclear Information System (INIS)
Cizek, J.C.; Florence, A.L.
1983-01-01
Particle velocity records that describe spherical waves in rock simulants, tuffs, salt, and granite have been obtained in laboratory experiments. The records aid the modeling of constitutive equations for continuum mechanics codes used in DNA containment research. The technique has also been applied to investigate containment-related problems involving material poperties, failure criteria, scaling, decoupling, and residual strain field relaxation. 22 figures
Design of mechanical coxa joints based on three-degree-of-freedom spherical parallel manipulators
International Nuclear Information System (INIS)
Li, Yanbiao; Ji, Shiming; Wang, Zhongfei; Jin, Mingsheng; Liu, Yi; Jin, Zhenlin
2013-01-01
We addressed the issue of the design of mechanical coxa joints based on three-degree-of-freedom spherical parallel manipulators using the parameter statistics optimum method based on index atlases. The coxa joints have the advantages of high payload, high accuracy, and good technological efficiency. The first step of the design and prototyping used in this paper develops the direct and inverse displacement equations from the layout feature of the mechanical coxa joints. Then, the shapes of a constant-orientation workspace of the mechanical coxa joints are described, and the effects of the design parameters on the workspace volume are studied quantitatively. The next step deals with the graphical representation of the atlases that illustrates the relationship between performance evaluation index and design parameters based on the kinematics and torque analysis of the mechanical coxa joints. Finally, the geometric parameters of the coxa joints are obtained by the parameter statistics optimum method based on the index atlases. Considering assembly conditions, the design scheme of the mechanical coxa joints is developed, which provides a theoretical basis for the application of the mechanical coxa joints.
The impact of tissue Doppler index E/e' ratio on instantaneous wave-free ratio.
Arashi, Hiroyuki; Yamaguchi, Junichi; Ri, Tonre; Otsuki, Hisao; Nakao, Masashi; Kamishima, Kazuho; Jujo, Kentaro; Minami, Yuichiro; Ogawa, Hiroshi; Hagiwara, Nobuhisa
2018-03-01
The instantaneous wave-free ratio (iFR) is a vasodilator-free, invasive pressure wire index of the functional severity of coronary stenosis and is calculated under resting conditions. In a recent study, iFR was found to be more closely linked to coronary flow reserve (CFR) than fractional flow reserve (FFR). E/e' is a surrogate marker of left ventricular (LV) filling pressure and LV diastolic dysfunction. Coronary resting flow was found to be increased in patients with elevated E/e', and higher coronary resting flow was associated with lower CFR. Higher baseline coronary flow induces a greater loss of translesional pressure and may affect iFR. However, no reports have examined the impact of E/e' on iFR. The purpose of this study was to assess the relationship between iFR and E/e' compared with FFR. We retrospectively examined 103 consecutive patients (142 with stenosis) whose iFR, FFR, and E/e' were measured simultaneously. The mean age, LV mass index, and systolic blood pressure of patients with elevated E/e' were higher than those of patients with normal E/e'. Although no significant differences were observed in mean FFR values and % diameter stenosis, the mean iFR value in patients with elevated E/e' was significantly lower than that in patients with normal E/e'. The iFR was negatively correlated with E/e', while there was no correlation between FFR and E/e'. Multivariate analysis showed that E/e' and % diameter stenosis were independent determinants of iFR. E/e' ratio affects iFR values. Our results suggest that FFR mainly reflects the functional severity of the epicardial stenosis whereas iFR could potentially be influenced by not only epicardial stenosis but also other factors related to LV filling pressure or LV diastolic dysfunction. Further research is needed to understand the underlying mechanisms that influence the evaluation of iFR in patients with elevated E/e'. Copyright © 2017 Japanese College of Cardiology. Published by Elsevier Ltd. All rights
Water hammer caused by closure of turbine safety spherical valves
Karadžić, U.; Bergant, A.; Vukoslavčević, P.
2010-08-01
This paper investigates water hammer effects caused by closure of spherical valves against the discharge. During the first phase of modernisation of Perućica high-head hydropower plant (HPP), Montenegro, safety spherical valves (inlet turbine valves) have been refurbished on the first two Pelton turbine units. The valve closure is controlled by the valve actuator (hydraulic servomotor). Because the torque acting on the valve body is dependent on flow conditions the valve closing time may vary significantly for different flow velocities (passive valve). For the passive valve the torques acting on the valve body should be considered in the valve model. The valve closing time results from numerical simulation. On the contrary, for the active valve the valve closing time is assumed prior to simulation. The spherical valve boundary condition is incorporated into the method of characteristics (MOC) algorithm. The staggered (diamond) grid in applying the MOC is used in this paper. The passive valve boundary condition is described by the water hammer equations, the valve equation that relates discharge to pressure head drop and the dynamic equation of the valve body motion (torque equation). The active valve boundary condition is described by the first two equations, respectively. Standard quasi-steady friction model is used for estimating friction losses in plant's tunnel and penstocks. Numerical results using both the active and the passive spherical valve models are compared with results of measurements. It has been found that the influence of flow conditions on the spherical valve closing time is minor for the cases considered. Computed and measured results agree reasonably well.
Water hammer caused by closure of turbine safety spherical valves
International Nuclear Information System (INIS)
Karadzic, U; Vukoslavcevic, P; Bergant, A
2010-01-01
This paper investigates water hammer effects caused by closure of spherical valves against the discharge. During the first phase of modernisation of Perucica high-head hydropower plant (HPP), Montenegro, safety spherical valves (inlet turbine valves) have been refurbished on the first two Pelton turbine units. The valve closure is controlled by the valve actuator (hydraulic servomotor). Because the torque acting on the valve body is dependent on flow conditions the valve closing time may vary significantly for different flow velocities (passive valve). For the passive valve the torques acting on the valve body should be considered in the valve model. The valve closing time results from numerical simulation. On the contrary, for the active valve the valve closing time is assumed prior to simulation. The spherical valve boundary condition is incorporated into the method of characteristics (MOC) algorithm. The staggered (diamond) grid in applying the MOC is used in this paper. The passive valve boundary condition is described by the water hammer equations, the valve equation that relates discharge to pressure head drop and the dynamic equation of the valve body motion (torque equation). The active valve boundary condition is described by the first two equations, respectively. Standard quasi-steady friction model is used for estimating friction losses in plant's tunnel and penstocks. Numerical results using both the active and the passive spherical valve models are compared with results of measurements. It has been found that the influence of flow conditions on the spherical valve closing time is minor for the cases considered. Computed and measured results agree reasonably well.
Water hammer caused by closure of turbine safety spherical valves
Energy Technology Data Exchange (ETDEWEB)
Karadzic, U; Vukoslavcevic, P [Faculty of Mechanical Engineering, University of Montenegro Dzordza Vasingtona nn, Podgorica, 81000 (Montenegro); Bergant, A, E-mail: uros.karadzic@ac.m [LitostrojPower d.o.o., Litostrojska 50, Ljubljana, 1000 (Slovenia)
2010-08-15
This paper investigates water hammer effects caused by closure of spherical valves against the discharge. During the first phase of modernisation of Perucica high-head hydropower plant (HPP), Montenegro, safety spherical valves (inlet turbine valves) have been refurbished on the first two Pelton turbine units. The valve closure is controlled by the valve actuator (hydraulic servomotor). Because the torque acting on the valve body is dependent on flow conditions the valve closing time may vary significantly for different flow velocities (passive valve). For the passive valve the torques acting on the valve body should be considered in the valve model. The valve closing time results from numerical simulation. On the contrary, for the active valve the valve closing time is assumed prior to simulation. The spherical valve boundary condition is incorporated into the method of characteristics (MOC) algorithm. The staggered (diamond) grid in applying the MOC is used in this paper. The passive valve boundary condition is described by the water hammer equations, the valve equation that relates discharge to pressure head drop and the dynamic equation of the valve body motion (torque equation). The active valve boundary condition is described by the first two equations, respectively. Standard quasi-steady friction model is used for estimating friction losses in plant's tunnel and penstocks. Numerical results using both the active and the passive spherical valve models are compared with results of measurements. It has been found that the influence of flow conditions on the spherical valve closing time is minor for the cases considered. Computed and measured results agree reasonably well.
Fabrication and electromechanical examination of a spherical dielectric elastomer actuator
International Nuclear Information System (INIS)
Ahmadi, S; Gooyers, M; Soleimani, M; Menon, C
2013-01-01
In this paper, a procedure for fabricating and testing a seamless spherical dielectric elastomer actuator (DEA) is presented. In previously developed spherical prototypes, the DEA material is pre-strained by a rigid frame to improve the actuator’s output force; however, it is possible to pre-strain a spherical DEA by inflating the sample with a liquid or gas as long as the sample contains the pressure. In this work, a very compliant silicone-based material was used to fabricate a nearly spherical balloon-shaped prototype. The DEA sample was inflated by air and various electrical-actuation regimes were considered. The performance of the DEA sample was studied using an analytical and a finite element-based model. An Ogden hyperelastic model was used in formulation of the analytical model to include nonlinear behavior of the silicone material. Full statistical analysis of the experimental and numerical results was carried out using the root-mean-square (RMS) error and the normalized RMS error. The analytical and FEM results were in good agreement with the experimental data. According to modeling results, it was found that the DEA’s actuation force can be mainly improved by increasing the voltage, reducing the thickness, lowering the stiffness, and/or increasing the initial pressure. As an example, a three-fold increase of the actuation force was found when the thickness was reduced to half of its initial value. This improvement of the efficiency suggests that the spherical DEA is suitable for use in several applications if an appropriate design with optimal governing parameters is developed. (paper)
Detecting topology in a nearly flat spherical universe
International Nuclear Information System (INIS)
Weeks, Jeffrey; Lehoucq, Roland; Uzan, Jean-Philippe
2003-01-01
When the density parameter is close to unity, the universe has a large curvature radius independent of its being hyperbolic or spherical, or in the limiting case of an infinite curvature radius, flat. Whatever the curvature, the universe may have either a simply connected or a multiply connected topology. In the flat case, the topology scale is arbitrary, and there is no a priori reason for this scale to be of the same order as the size of the observable universe. In the hyperbolic case, any nontrivial topology would almost surely be on a length scale too large to detect. In the spherical case, in contrast, the topology could easily occur on a detectable scale. The present paper shows how, in the spherical case, the assumption of a nearly flat universe simplifies the algorithms for detecting a multiply connected topology, but also reduces the amount of topology that can be seen. This is of primary importance for the upcoming cosmic microwave background data analysis. This paper shows that for spherical spaces one may restrict the search to diametrically opposite pairs of circles in the circles-in-the-sky method and still detect the cyclic factor in the standard factorization of the holonomy group. This vastly decreases the algorithm's run time. If the search is widened to include pairs of candidate circles whose centres are almost opposite and whose relative twist varies slightly, then the cyclic factor along with a cyclic subgroup of the general factor may also be detected. Unfortunately, the full holonomy group is, in general, unobservable in a nearly flat spherical universe, and so a full six-parameter search is unnecessary. Crystallographic methods could also potentially detect the cyclic factor and a cyclic subgroup of the general factor, but nothing else
Detecting topology in a nearly flat spherical universe
Energy Technology Data Exchange (ETDEWEB)
Weeks, Jeffrey [15 Farmer St, Canton NY 13617-1120 (United States); Lehoucq, Roland [CE-Saclay, DSM/DAPNIA/Service d' Astrophysique, F-91191 Gif sur Yvette Cedex (France); Uzan, Jean-Philippe [Institut d' Astrophysique de Paris, GReCO, CNRS-FRE 2435, 98 bis, Bd Arago, 75014 Paris (France)
2003-04-21
When the density parameter is close to unity, the universe has a large curvature radius independent of its being hyperbolic or spherical, or in the limiting case of an infinite curvature radius, flat. Whatever the curvature, the universe may have either a simply connected or a multiply connected topology. In the flat case, the topology scale is arbitrary, and there is no a priori reason for this scale to be of the same order as the size of the observable universe. In the hyperbolic case, any nontrivial topology would almost surely be on a length scale too large to detect. In the spherical case, in contrast, the topology could easily occur on a detectable scale. The present paper shows how, in the spherical case, the assumption of a nearly flat universe simplifies the algorithms for detecting a multiply connected topology, but also reduces the amount of topology that can be seen. This is of primary importance for the upcoming cosmic microwave background data analysis. This paper shows that for spherical spaces one may restrict the search to diametrically opposite pairs of circles in the circles-in-the-sky method and still detect the cyclic factor in the standard factorization of the holonomy group. This vastly decreases the algorithm's run time. If the search is widened to include pairs of candidate circles whose centres are almost opposite and whose relative twist varies slightly, then the cyclic factor along with a cyclic subgroup of the general factor may also be detected. Unfortunately, the full holonomy group is, in general, unobservable in a nearly flat spherical universe, and so a full six-parameter search is unnecessary. Crystallographic methods could also potentially detect the cyclic factor and a cyclic subgroup of the general factor, but nothing else.
Relative Pose Estimation and Accuracy Verification of Spherical Panoramic Image
Directory of Open Access Journals (Sweden)
XIE Donghai
2017-11-01
Full Text Available This paper improves the method of the traditional 5-point relative pose estimation algorithm, and proposes a relative pose estimation algorithm which is suitable for spherical panoramic images. The algorithm firstly computes the essential matrix, then decomposes the essential matrix to obtain the rotation matrix and the translation vector using SVD, and finally the reconstructed three-dimensional points are used to eliminate the error solution. The innovation of the algorithm lies the derivation of panorama epipolar formula and the use of the spherical distance from the point to the epipolar plane as the error term for the spherical panorama co-planarity function. The simulation experiment shows that when the random noise of the image feature points is within the range of pixel, the error of the three Euler angles is about 0.1°, and the error between the relative translational displacement and the simulated value is about 1.5°. The result of the experiment using the data obtained by the vehicle panorama camera and the POS shows that:the error of the roll angle and pitch angle can be within 0.2°, the error of the heading angle can be within 0.4°, and the error between the relative translational displacement and the POS can be within 2°. The result of our relative pose estimation algorithm is used to generate the spherical panoramic epipolar images, then we extract the key points between the spherical panoramic images and calculate the errors in the column direction. The result shows that the errors is less than 1 pixel.
Application of identifying transmission spheres for spherical surface testing
Han, Christopher B.; Ye, Xin; Li, Xueyuan; Wang, Quanzhao; Tang, Shouhong; Han, Sen
2017-06-01
We developed a new application on Microsoft Foundation Classes (MFC) to identify correct transmission spheres (TS) for Spherical Surface Testing (SST). Spherical surfaces are important optical surfaces, and the wide application and high production rate of spherical surfaces necessitates an accurate and highly reliable measuring device. A Fizeau Interferometer is an appropriate tool for SST due to its subnanometer accuracy. It measures the contour of a spherical surface using a common path, which is insensitive to the surrounding circumstances. The Fizeau Interferometer transmits a wide laser beam, creating interference fringes from re-converging light from the transmission sphere and the test surface. To make a successful measurement, the application calculates and determines the appropriate transmission sphere for the test surface. There are 3 main inputs from the test surfaces that are utilized to determine the optimal sizes and F-numbers of the transmission spheres: (1) the curvatures (concave or convex), (2) the Radii of Curvature (ROC), and (3) the aperture sizes. The application will firstly calculate the F-numbers (i.e. ROC divided by aperture) of the test surface, secondly determine the correct aperture size of a convex surface, thirdly verify that the ROC of the test surface must be shorter than the reference surface's ROC of the transmission sphere, and lastly calculate the percentage of area that the test surface will be measured. However, the amount of interferometers and transmission spheres should be optimized when measuring large spherical surfaces to avoid requiring a large amount of interferometers and transmission spheres for each test surface. Current measuring practices involve tedious and potentially inaccurate calculations. This smart application eliminates human calculation errors, optimizes the selection of transmission spheres (including the least number required) and interferometer sizes, and increases efficiency.
Determining spherical lens correction for astronaut training underwater.
Porter, Jason; Gibson, C Robert; Strauss, Samuel
2011-09-01
To develop a model that will accurately predict the distance spherical lens correction needed to be worn by National Aeronautics and Space Administration astronauts while training underwater. The replica space suit's helmet contains curved visors that induce refractive power when submersed in water. Anterior surface powers and thicknesses were measured for the helmet's protective and inside visors. The impact of each visor on the helmet's refractive power in water was analyzed using thick lens calculations and Zemax optical design software. Using geometrical optics approximations, a model was developed to determine the optimal distance spherical power needed to be worn underwater based on the helmet's total induced spherical power underwater and the astronaut's manifest spectacle plane correction in air. The validity of the model was tested using data from both eyes of 10 astronauts who trained underwater. The helmet's visors induced a total power of -2.737 D when placed underwater. The required underwater spherical correction (FW) was linearly related to the spectacle plane spherical correction in air (FAir): FW = FAir + 2.356 D. The mean magnitude of the difference between the actual correction worn underwater and the calculated underwater correction was 0.20 ± 0.11 D. The actual and calculated values were highly correlated (r = 0.971) with 70% of eyes having a difference in magnitude of astronauts. The model accurately predicts the actual values worn underwater and can be applied (more generally) to determine a suitable spectacle lens correction to be worn behind other types of masks when submerged underwater.
Energy Technology Data Exchange (ETDEWEB)
Chen, Zhan-Bin, E-mail: chenzb008@qq.com [College of Science, National University of Defense Technology, Changsha, Hunan 410073 (China); Ma, Kun [School of Information Engineering, Huangshan University, Huangshan 245041 (China); Wang, Hong-Jian [Chongqing Key Laboratory for Design and Control of Manufacturing Equipment, Chongqing Technology and Business University, Chongqing 40067 (China); Wang, Kai, E-mail: wangkai@hbu.edu.cn [Hebei Key Lab of Optic-electronic Information and Materials, The College of Physics Science and Technology, Hebei University, Baoding 071002 (China); Liu, Xiao-Bin [Department of Physics, Tianshui Normal University, Tianshui 741001 (China); Zeng, Jiao-Long [College of Science, National University of Defense Technology, Changsha, Hunan 410073 (China)
2017-01-15
Detailed calculations using the multi-configuration Dirac–Fock (MCDF) method are carried out for the lowest 64 fine-structure levels of the 3s{sup 2}3p{sup 2}, 3s{sup 2}3p3d, 3s3p{sup 3}, 3s3p{sup 2}3d, 3s{sup 2}3d{sup 2}, and 3p{sup 4} configurations in Si-like ions of La XLIII, Er LIV, Tm LV, and Yb LVI. Energies, oscillator strengths, wavelengths, line strengths, and radiative electric dipole transition rates are given for all ions. A parallel calculation using the many-body perturbation theory (MBPT) method is also carried out to assess the present energy levels accuracy. Comparisons are performed between these two sets of energy levels, as well as with other available results, showing that they are in good agreement with each other within 0.5%. These high accuracy results can be used to the modeling and the interpretation of astrophysical objects and fusion plasmas. - Highlights: • Energy levels and E1 transition rates of Si-like ions are presented. • Breit interaction and Quantum Electrodynamics effects are discussed. • Present results should be useful in the astrophysical application and plasma modeling.
International Nuclear Information System (INIS)
Farrar, G.L.
1993-01-01
The accompanying table compares refinery construction and operating wages monthly for the years 1990 and 1991. The Nelson-Farrar refinery construction cost indexes are inflation indexes, while the operating indexes incorporate a productivity which shows improvement with experience and the increasing size of operations. The refinery construction wage indexes in the table show a steady advance over the 2-year period. Common labor indexes moved up faster than skilled indexes. Refinery operating wages showed a steady increase, while productivities averaged higher near the end of the period. Net result is that labor costs remained steady for the period
Atomic Force Microscopy Based Cell Shape Index
Adia-Nimuwa, Usienemfon; Mujdat Tiryaki, Volkan; Hartz, Steven; Xie, Kan; Ayres, Virginia
2013-03-01
Stellation is a measure of cell physiology and pathology for several cell groups including neural, liver and pancreatic cells. In the present work, we compare the results of a conventional two-dimensional shape index study of both atomic force microscopy (AFM) and fluorescent microscopy images with the results obtained using a new three-dimensional AFM-based shape index similar to sphericity index. The stellation of astrocytes is investigated on nanofibrillar scaffolds composed of electrospun polyamide nanofibers that has demonstrated promise for central nervous system (CNS) repair. Recent work by our group has given us the ability to clearly segment the cells from nanofibrillar scaffolds in AFM images. The clear-featured AFM images indicated that the astrocyte processes were longer than previously identified at 24h. It was furthermore shown that cell spreading could vary significantly as a function of environmental parameters, and that AFM images could record these variations. The new three-dimensional AFM-based shape index incorporates the new information: longer stellate processes and cell spreading. The support of NSF PHY-095776 is acknowledged.
Energy Technology Data Exchange (ETDEWEB)
Sugihara, Masami [Kanazawa Univ. (Japan). School of Medicine
1982-02-01
In order to determine the usefulness of nuclear cardiology methods in evaluating infarction size and in predicting subsequent mortality, the infarction size index was calculated and their left ventricular ejection fraction (LVEF) was measured for 136 patients with acute myocardial infarction, by means of sup(99m)Tc- and /sup 201/Tl-scintigraphy. Sensitivity of sup(99m)Tc-scintigraphy was 84% (of 44 cases). The hot sup(99m)Tc-areas were measured by planimetry only in anterior transmural infarctions. For 15 patients followed for 25 months on the average, hot areas were 13.8 +- 10.8 cm/sup 2/ in survivors and 31.7 +- 18.2 cm/sup 2/ in non-survivors. Both a doughnut pattern and persistent hot area in scintigraphs were signs of poor prognosis. Sensitivity of /sup 201/Tl-scintigraphy was 86% (of 95 cases). The extent of /sup 201/Tl perfusion defects was determined in three views by the average ratio of the length of perfusion defects to that of the left ventricle (LV). Interobserver correlation was high (r = 0.89). As the percent /sup 201/Tl defect index increased, the peak value of creatine phosphokinase, the grade of Peel index, incidence of congestion on initial chest X-ray, and LV aneurysma all gradually increased. In 48 patients followed for 23 months on the average after discharge, the incidence of congestive heart failure and mortality also increased with the larger degree of percent /sup 201/Tl defect index. In particular, the prognosis was poor in patients who had the percent /sup 201/Tl defect index larger than 40%. The LVEF, measured with a computerized multi-crystal gamma camera, was well correlated with that of contrast ventriculography (r = 0.92). The patients who had severe LV dysfunction and the LVEF less than 31% also showed poor prognosis.
Western Alaska ESI: INDEX (Index Polygons)
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries of all the hardcopy cartographic products produced as part of the Environmental Sensitivity Index...
Department of Veterans Affairs — As of June 28, 2010, the Master Veteran Index (MVI) database based on the enhanced Master Patient Index (MPI) is the authoritative identity service within the VA,...
U.S. Environmental Protection Agency — Human land uses may have major impacts on ecosystems, affecting biodiversity, habitat, air and water quality. The human use index (also known as U-index) is the...
U.S. Environmental Protection Agency — Human land uses may have major impacts on ecosystems, affecting biodiversity, habitat, air and water quality. The human use index (also known as U-index) is the...
U.S. Department of Health & Human Services — IndexCat provides access to the digitized version of the printed Index-Catalogue of the Library of the Surgeon General's Office; eTK for medieval Latin texts; and...
... Families ( We Can! ) Health Professional Resources Body Mass Index Table 1 for BMI greater than 35, go ... Health Information Email Alerts Jobs and Careers Site Index About NHLBI National Institute of Health Department of ...
On the spherical harmonic expansion of the neutron angular distribution function
Energy Technology Data Exchange (ETDEWEB)
Depken, Sven
1959-03-15
The neutron (one-velocity) angular distribution function is expanded in terms of spherical harmonic tensors. The solution to the equations of the moments is given explicitly and the result is applied to the plane, spherical and cylinder symmetrical cases.
On the spherical harmonic expansion of the neutron angular distribution function
International Nuclear Information System (INIS)
Depken, Sven
1959-03-01
The neutron (one-velocity) angular distribution function is expanded in terms of spherical harmonic tensors. The solution to the equations of the moments is given explicitly and the result is applied to the plane, spherical and cylinder symmetrical cases
E-Beam-Cured Layered-Silicate and Spherical Silica Epoxy Nanocomposites (Preprint)
National Research Council Canada - National Science Library
Chen, Chenggang; Anderson, David P
2007-01-01
.... The nanofillers can be two dimensional (layered-silicate) and zero dimensional (spherical silica). Both the spherical silica epoxy nanocomposite and the layered-silicate epoxy nanocomposite can be cured to a high degree of curing...
Spherical harmonic expansion of short-range screened Coulomb interactions
Energy Technology Data Exchange (ETDEWEB)
Angyan, Janos G [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Gerber, Iann [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Marsman, Martijn [Institut fuer Materialphysik and Center for Computational Materials Science, Universitaet Wien, Sensengasse 8, A-1090, Vienna (Austria)
2006-07-07
Spherical harmonic expansions of the screened Coulomb interaction kernel involving the complementary error function are required in various problems in atomic, molecular and solid state physics, like for the evaluation of Ewald-type lattice sums or for range-separated hybrid density functionals. A general analytical expression is derived for the kernel, which is non-separable in the radial variables. With the help of series expansions a separable approximate form is proposed, which is in close analogy with the conventional multipole expansion of the Coulomb kernel in spherical harmonics. The convergence behaviour of these expansions is studied and illustrated by the electrostatic potential of an elementary charge distribution formed by products of Slater-type atomic orbitals.
The ''Dolphin'' power laser installation for spherical thermonuclear target heating
International Nuclear Information System (INIS)
Basov, N.G.; Bykovskij, N.E.; Danilov, A.E.
1978-01-01
12-channel laser installation the ''Dolphin'' for thermonuclear target heating in the radiation spheric geometry has been developed to carry out series of physical investigations of laser-thermonuclear plasma system, optimization of target heating conditions and obtaining a comparatively large value of thermonuclear output in ratio to the energy of absorbed light radiation in the target. The description of installation main elements, consisting of the following components, is given: 1)neodymium laser with the maximum permissible radiation energy of 10kJ, with light pulse duration of 10 -10 /10 -9 c and radiation divergence of approximately 5x10 -4 rad; 2)vacuum chamber, where laser radiation interaction with plasma takes place; 3)diagnostic means of laser and plasma parameters and 4)focus system. The focus system provides a high degree of target spherical radiation symmetry at current maximum density on its surface of approximately 10 15 W/cm 2
Exploration of spherical torus physics in the NSTX device
Ono, M.; Kaye, S. M.; Peng, Y.-K. M.; Barnes, G.; Blanchard, W.; Carter, M. D.; Chrzanowski, J.; Dudek, L.; Ewig, R.; Gates, D.; Hatcher, R. E.; Jarboe, T.; Jardin, S. C.; Johnson, D.; Kaita, R.; Kalish, M.; Kessel, C. E.; Kugel, H. W.; Maingi, R.; Majeski, R.; Manickam, J.; McCormack, B.; Menard, J.; Mueller, D.; Nelson, B. A.; Nelson, B. E.; Neumeyer, C.; Oliaro, G.; Paoletti, F.; Parsells, R.; Perry, E.; Pomphrey, N.; Ramakrishnan, S.; Raman, R.; Rewoldt, G.; Robinson, J.; Roquemore, A. L.; Ryan, P.; Sabbagh, S.; Swain, D.; Synakowski, E. J.; Viola, M.; Williams, M.; Wilson, J. R.; NSTX Team
2000-03-01
The National Spherical Torus Experiment (NSTX) is being built at Princeton Plasma Physics Laboratory to test the fusion physics principles for the spherical torus concept at the MA level. The NSTX nominal plasma parameters are R0 = 85 cm, a = 67 cm, R/a >= 1.26, Bt = 3 kG, Ip = 1 MA, q95 = 14, elongation κ The plasma heating/current drive tools are high harmonic fast wave (6 MW, 5 s), neutral beam injection (5 MW, 80 keV, 5 s) and coaxial helicity injection. Theoretical calculations predict that NSTX should provide exciting possibilities for exploring a number of important new physics regimes, including very high plasma β, naturally high plasma elongation, high bootstrap current fraction, absolute magnetic well and high pressure driven sheared flow. In addition, the NSTX programme plans to explore fully non-inductive plasma startup as well as a dispersive scrape-off layer for heat and particle flux handling.
The Rayleigh-Taylor instability in the spherical pinch
International Nuclear Information System (INIS)
Chen, H.B.; Hilko, B.; Panarella, E.
1994-01-01
The spherical pinch (SP) concept is an outgrowth of the inertial confinement model (ICF). Unlike the ICF where instabilities, especially the Rayleigh-Taylor instability, have been studied extensively, the instability study of the spherical pinch has just begun. The Raleigh-Taylor instability is investigated for the first time in the SP in the present work. By using the simple condition for the Rayleigh-Taylor instability ∇p · ∇p < O (density and pressure gradients have opposite direction), we have qualitatively identified the regions for development of instabilities in the SP. It is found that the explosion phase (central discharge) is stable and instabilities take place in the imploding phase. However, the growth rate for the instability is not in exponential form, and the appearance of the Rayleigh-Taylor instability does not prevent the main shock wave from converging to the center of the sphere
Merging startup experiments on the UTST spherical tokamak
International Nuclear Information System (INIS)
Yamada, Takuma; Kamio, Shuji; Imazawa, Ryota
2010-01-01
The University of Tokyo Spherical Tokamak (UTST) was constructed to explore the formation of ultrahigh-beta spherical tokamak (ST) plasmas using double null plasma merging. The main feature of the UTST is that the poloidal field coils are located outside the vacuum vessel to demonstrate startup in a reactor-relevant situation. Initial operations used partially completed power supplies to investigate the appropriate conditions for plasma merging. The plasma current of the merged ST reached 100 kA when the central solenoid coil was used to assist plasma formation. Merging of two ST plasmas through magnetic reconnection was successfully observed using two-dimensional pickup coil arrays, which directly measure the toroidal and axial magnetic fields inside the UTST vacuum vessel. The resistivity of the current sheet was found to be anomalously high during merging. (author)
Spherical Harmonics Treatment of Epithermal Neutron Spectra in Reactor lattices
International Nuclear Information System (INIS)
Matausek, M.V.
1972-04-01
A procedure has been developed to solve the slowing down transport equation for neutrons in a cylindrized reactor lattice cell. Treating the anisotropy of the epithermal neutron flux by the spherical harmonics formalism, which reduces the space-angle-lethargy-dependent transport equation to the matrix integrodifferential equation in space and lethargy, and replacing the lethargy transfer integrals by finite-difference forms, a set of matrix ordinary differential equations, with lethargy and space dependent coefficients, is obtained. In the resonance region this set takes a lower block triangular form and can be directly solved by forward block substitution; in the lethargy range, where the fast fission effects have to be considered, the iterative procedure is introduced. A simple and efficient approximation is then proposed, making possible the analytical solution for the spatial dependence of the spherical harmonics flux moments. The proposed procedure has been numerically examined and approved. Some typical results are presented and discussed. (author)
Enhancement of octupole strength in near spherical nuclei
Energy Technology Data Exchange (ETDEWEB)
Robledo, L.M. [Universidad Autonoma de Madrid, Dep. Fisica Teorica, Facultad de Ciencias, Madrid (Spain)
2016-09-15
The validity of the rotational formula used to compute E1 and E3 transition strengths in even-even nuclei is analyzed within the Generator Coordinate Method framework based on mean field wave functions. It turns out that those nuclei with spherical or near spherical shapes the E1 and E3 strengths computed with this formula are strongly underestimated and a sound evaluation of them requires angular-momentum projected wave functions. Results for several isotopic chains with proton number equal to or near magic numbers are analyzed and compared with experimental data. The use of angular-momentum projected wave functions greatly improves the agreement with the scarce experimental data. (orig.)
On the Field of a Stationary Charged Spherical Source
Directory of Open Access Journals (Sweden)
Stavroulakis N.
2009-04-01
Full Text Available The equations of gravitation related to the field of a spherical charged source imply the existence of an interdependence between gravitation and electricity [5]. The present paper deals with the joint action of gravitation and electricity in the case of a stationary charged spherical source. Let m and " be respectively the mass and the charge of the source, and let k be the gravitational constant. Then the equations of gravitation need specific discussion according as j " j m p k (source strongly charged. In any case the curvature radius of the sphere bounding the matter possesses a strictly positive greatest lower hound, so that the source is necessarily an extended object. Pointwise sources do not exist. In particular, charged black holes do not exist.
Ultrasmooth, Highly Spherical Monocrystalline Gold Particles for Precision Plasmonics
Lee, You-Jin
2013-12-23
Ultrasmooth, highly spherical monocrystalline gold particles were prepared by a cyclic process of slow growth followed by slow chemical etching, which selectively removes edges and vertices. The etching process effectively makes the surface tension isotropic, so that spheres are favored under quasi-static conditions. It is scalable up to particle sizes of 200 nm or more. The resulting spherical crystals display uniform scattering spectra and consistent optical coupling at small separations, even showing Fano-like resonances in small clusters. The high monodispersity of the particles we demonstrate should facilitate the self-assembly of nanoparticle clusters with uniform optical resonances, which could in turn be used to fabricate optical metafluids. Narrow size distributions are required to control not only the spectral features but also the morphology and yield of clusters in certain assembly schemes. © 2013 American Chemical Society.
Morphological and electrochemical studies of spherical boron doped diamond electrodes
Energy Technology Data Exchange (ETDEWEB)
Mendes de Barros, R.C. [IQ/USP, Av. Lineu Prestes, 748, Bloco 2 Superior, Cidade Universitaria, Sao Paulo/SP, 05508-900 (Brazil); Ferreira, N.G. [LAS/INPE, Av. dos Astronautas, 1758, Jardim da Granja, Sao Jose dos Campos/SP, 12245-970 (Brazil); Azevedo, A.F. [LAS/INPE, Av. dos Astronautas, 1758, Jardim da Granja, Sao Jose dos Campos/SP, 12245-970 (Brazil); Corat, E.J. [LAS/INPE, Av. dos Astronautas, 1758, Jardim da Granja, Sao Jose dos Campos/SP, 12245-970 (Brazil); Sumodjo, P.T.A. [IQ/USP, Av. Lineu Prestes, 748, Bloco 2 Superior, Cidade Universitaria, Sao Paulo/SP, 05508-900 (Brazil); Serrano, S.H.P. [IQ/USP, Av. Lineu Prestes, 748, Bloco 2 Superior, Cidade Universitaria, Sao Paulo/SP, 05508-900 (Brazil)]. E-mail: shps@iq.usp.br
2006-08-14
Morphological and electrochemical characteristics of boron doped diamond electrode in new geometric shape are presented. The main purpose of this study is a comparison among voltammetric behavior of planar glassy carbon electrode (GCE), planar boron doped diamond electrode (PDDE) and spherical boron doped diamond electrode (SDDE), obtained from similar experimental parameters. SDDE was obtained by the growth of boron doped film on textured molybdenum tip. This electrode does not present microelectrode characteristics. However, its voltammetric peak current, determined at low scan rates, is largest associated to the smallest {delta}E {sub p} values for ferrocyanide system when compared with PDDE or GCE. In addition, the capacitance is about 200 times smaller than that for GCE. These results show that the analytical performance of boron doped diamond electrodes can be implemented just by the change of sensor geometry, from plane to spherical shape.
Spherical gyroscopic moment stabilizer for attitude control of microsatellites
Keshtkar, Sajjad; Moreno, Jaime A.; Kojima, Hirohisa; Uchiyama, Kenji; Nohmi, Masahiro; Takaya, Keisuke
2018-02-01
This paper presents a new and improved concept of recently proposed two-degrees of freedom spherical stabilizer for triaxial orientation of microsatellites. The analytical analysis of the advantages of the proposed mechanism over the existing inertial attitude control devices are introduced. The extended equations of motion of the stabilizing satellite including the spherical gyroscope, for control law design and numerical simulations, are studied in detail. A new control algorithm based on continuous high-order sliding mode algorithms, for managing the torque produced by the stabilizer and therefore the attitude control of the satellite in the presence of perturbations/uncertainties, is presented. Some numerical simulations are carried out to prove the performance of the proposed mechanism and control laws.
Laser driven compression and neutron generation with spherical shell targets
International Nuclear Information System (INIS)
Campbell, P.M.; Hammerling, P.; Johnson, R.R.; Kubis, J.J.; Mayer, F.J.
1977-01-01
Laser-driven implosion experiments using DT-gas-filled spherical glass-shell targets are described. Neutron yields to 5 x 10 7 are produced from implosions of small ( -- 55 μm-diameter) targets spherically illuminated with an on-target laser power of 0.4 terawatt. Nuclear reaction product diagnostics, X-ray pinhole photographs, fast-ion spectra and X-ray measurements are used in conjunction with hydrodynamic computer code simulations to investigate the implosion phenomenology as well as the target corona evolution. Simulations using completely classical effects are not able to describe the full range of experimental data. Electron or radiation preheating may be required to explain some implosion measurements. (auth.)
Implications of the Cosmological Constant for Spherically Symmetric Mass Distributions
Zubairi, Omair; Weber, Fridolin
2013-04-01
In recent years, scientists have made the discovery that the expansion rate of the Universe is increasing rather than decreasing. This acceleration leads to an additional term in Albert Einstein's field equations which describe general relativity and is known as the cosmological constant. This work explores the aftermath of a non-vanishing cosmological constant for relativistic spherically symmetric mass distributions, which are susceptible to change against Einstein's field equations. We introduce a stellar structure equation known as the Tolman-Oppenhiemer-Volkoff (TOV) equation modified for a cosmological constant, which is derived from Einstein's modified field equations. We solve this modified TOV equation for these spherically symmetric mass distributions and obtain stellar properties such as mass and radius and investigate changes that may occur depending on the value of the cosmological constant.
Preparation procedure for spherical titanium powders by RF induction plasma
International Nuclear Information System (INIS)
Gu Zhongtao; Jin Yuping; Ye Gaoying
2011-01-01
The paper uses the single-factor method for the study of spherical titanium powder preparation process. Titanium powders with excellent sphericity can be prepared through controlling and regulating the radio frequency plasma anode working current and voltage, central gas flow rate, sheath gas flow rate, powder-carrying gas flow rate, negative ventilation pressure and powder feed rate, etc. Spheroidization of titanium powders with a size of (17.0±2.0) μm is performed by radio frequency plasma technology. With the increase of negative ventilation pressure, the spheroidization rate of titanium powders increases firstly and then decreases rapidly at the turning point around 1800 Pa. With the rate of powder feed increasing, the spheroidization rate of titanium powders increases firstly. When the powder feed rate is greater than 90.0 g/min, the spheroidization rate of titanium powders reduces rapidly as the powder feed rate increases. (authors)
Rotationally invariant clustering of diffusion MRI data using spherical harmonics
DEFF Research Database (Denmark)
Liptrot, Matthew George; Lauze, Francois Bernard
2016-01-01
simple features that are invariant to the rotation of the highly orientational diffusion data. This provides a way to directly classify voxels whose diffusion characteristics are similar yet whose primary diffusion orientations differ. Subsequent application of machine-learning to the spherical harmonic...... data as a collection of spherical basis functions. We use the derived coefficients as voxelwise feature vectors for classification. Using a simple Gaussian mixture model, we examined the classification performance for a range of sub-classes (3-20). The results were compared against existing...... classification of DWI data can be performed without the need for a model reconstruction step. This avoids the potential confounds and uncertainty that such models may impose, and has the benefit of being computable directly from the DWI volumes. As such, the method could prove useful in subsequent pre...
Finite size melting of spherical solid-liquid aluminium interfaces
DEFF Research Database (Denmark)
Chang, J.; Johnson, Erik; Sakai, T.
2009-01-01
We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting tempera...... to the conclusion that the depressed melting temperature is not controlled solely by the inverse radius 1/R. Instead, we found a direct relation between the depressed melting temperature and the ratio between the solid-liquid interface area and the molten volume.......We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting...
Pair distribution function and structure factor of spherical particles
International Nuclear Information System (INIS)
Howell, Rafael C.; Proffen, Thomas; Conradson, Steven D.
2006-01-01
The availability of neutron spallation-source instruments that provide total scattering powder diffraction has led to an increased application of real-space structure analysis using the pair distribution function. Currently, the analytical treatment of finite size effects within pair distribution refinement procedures is limited. To that end, an envelope function is derived which transforms the pair distribution function of an infinite solid into that of a spherical particle with the same crystal structure. Distributions of particle sizes are then considered, and the associated envelope function is used to predict the particle size distribution of an experimental sample of gold nanoparticles from its pair distribution function alone. Finally, complementing the wealth of existing diffraction analysis, the peak broadening for the structure factor of spherical particles, expressed as a convolution derived from the envelope functions, is calculated exactly for all particle size distributions considered, and peak maxima, offsets, and asymmetries are discussed
Realization of a Service Robot for Cleaning Spherical Surfaces
Directory of Open Access Journals (Sweden)
Houxiang Zhang
2005-03-01
Full Text Available There are more and more buildings with complicated shape emerging all over the world. Their walls require constant cleaning which is difficult to realize. In this paper, based on analyzing the characteristics of the working target, a new kind of auto-climbing robot is proposed, which is used for cleaning the spherical surface of the National GrandTheatre in China. The robots' mechanism and unique aspects are presented in detail. A distributed controller based onCAN bus is designed to meet the requirements of controlling the robot. The control system is divided into 6 parts, fiveCAN bus control nodes and a remote controller, which are designed and established based mainly on the P80C592. Finally, the motion function is described in detail. The experimental results confirm the principle described above andthe robot's ability to work on the spherical surface.
Analysis of Shield Construction in Spherical Weathered Granite Development Area
Cao, Quan; Li, Peigang; Gong, Shuhua
2018-01-01
The distribution of spherical weathered bodies (commonly known as "boulder") in the granite development area directly affects the shield construction of urban rail transit engineering. This paper is based on the case of shield construction of granite globular development area in Southern China area, the parameter control in shield machine selection and shield advancing during the shield tunneling in this special geological environment is analyzed. And it is suggested that shield machine should be selected for shield construction of granite spherical weathered zone. Driving speed, cutter torque, shield machine thrust, the amount of penetration and the speed of the cutter head of shield machine should be controlled when driving the boulder formation, in order to achieve smooth excavation and reduce the disturbance to the formation.
Analyzing correlation functions with tesseral and Cartesian spherical harmonics
International Nuclear Information System (INIS)
Danielewicz, Pawel; Pratt, Scott
2007-01-01
The dependence of interparticle correlations on the orientation of particle relative momentum can yield unique information on the space-time features of emission in reactions with multiparticle final states. In the present paper, the benefits of a representation and analysis of the three-dimensional correlation information in terms of surface spherical harmonics is presented. The harmonics include the standard complex tesseral harmonics and the real Cartesian harmonics. Mathematical properties of the lesser known Cartesian harmonics are illuminated. The physical content of different angular harmonic components in a correlation is described. The resolving power of different final-state effects with regard to determining angular features of emission regions is investigated. The considered final-state effects include identity interference, strong interactions, and Coulomb interactions. The correlation analysis in terms of spherical harmonics is illustrated with the cases of Gaussian and blast-wave sources for proton-charged meson and baryon-baryon pairs
Nonlinear Interaction of Waves in Rotating Spherical Layers
Zhilenko, D.; Krivonosova, O.; Gritsevich, M.
2018-01-01
Flows of a viscous incompressible fluid in a spherical layer that are due to rotational oscillations of its inner boundary at two frequencies with respect to the state of rest are numerically studied. It is found that an increase in the amplitude of oscillations of the boundary at the higher frequency can result in a significant enhancement of the low-frequency mode in a flow near the outer boundary. The direction of propagation of the low-frequency wave changes from radial to meridional, whereas the high-frequency wave propagates in the radial direction in a limited inner region of the spherical layer. The role of the meridional circulation in the energy exchange between spaced waves is demonstrated.
Determination of pitch rotation in a spherical birefringent microparticle
Roy, Basudev; Ramaiya, Avin; Schäffer, Erik
2018-03-01
Rotational motion of a three dimensional spherical microscopic object can happen either in pitch, yaw or roll fashion. Among these, the yaw motion has been conventionally studied using the intensity of scattered light from birefringent microspheres through crossed polarizers. Up until now, however, there is no way to study the pitch motion in spherical microspheres. Here, we suggest a new method to study the pitch motion of birefringent microspheres under crossed polarizers by measuring the 2-fold asymmetry in the scattered signal either using video microscopy or with optical tweezers. We show a couple of simple examples of pitch rotation determination using video microscopy for a microsphere attached with a kinesin molecule while moving along a microtubule and of a particle diffusing freely in water.
The inverse spatial Laplacian of spherically symmetric spacetimes
International Nuclear Information System (INIS)
Fernandes, Karan; Lahiri, Amitabha
2017-01-01
We derive the inverse spatial Laplacian for static, spherically symmetric backgrounds by solving Poisson’s equation for a point source. This is different from the electrostatic Green function, which is defined on the four dimensional static spacetime, while the equation we consider is defined on the spatial hypersurface of such spacetimes. This Green function is relevant in the Hamiltonian dynamics of theories defined on spherically symmetric backgrounds, and closed form expressions for the solutions we find are absent in the literature. We derive an expression in terms of elementary functions for the Schwarzschild spacetime, and comment on the relation of this solution with the known Green function of the spacetime Laplacian operator. We also find an expression for the Green function on the static pure de-Sitter space in terms of hypergeometric functions. We conclude with a discussion of the constraints of the electromagnetic field. (paper)
Recent results from the National Spherical Torus Experiment
International Nuclear Information System (INIS)
Maingi, R; Bell, M G; Bell, R E; Bialek, J; Bourdelle, C; Bush, C E; Darrow, D S; Fredrickson, E D; Gates, D A; Gilmore, M; Gray, T; Jarboe, T R; Johnson, D W; Kaita, R; Kaye, S M; Kubota, S; Kugel, H W; LeBlanc, B P; Maqueda, R J; Mastrovito, D; Medley, S S; Menard, J E; Mueller, D; Nelson, B A; Ono, M; Paoletti, F; Park, H K; Paul, S F; Peebles, T; Peng, Y-K M; Phillips, C K; Raman, R; Rosenberg, A L; Roquemore, A L; Ryan, P M; Sabbagh, S A; Skinner, C H; Soukhanovskii, V A; Stutman, D; Swain, D W; Synakowski, E J; Taylor, G; Wilgen, J; Wilson, J R; Wurden, G A; Zweben, S J
2003-01-01
The National Spherical Torus Experiment (NSTX) is a low aspect-ratio fusion research facility whose research goal is to make a determination of the attractiveness of the spherical torus concept in the areas of high-β stability, confinement, current drive, and divertor physics. Remarkable progress was made in extending the operational regime of the device in FY 2002. In brief, β t of 34% and β N of 6.5 were achieved. H-mode became the main operational regime, and energy confinement exceeded conventional aspect-ratio tokamak scalings. Heating was demonstrated with the radiofrequency antenna, and signatures of current drive were observed. Current initiation with coaxial helicity injection produced discharges of 400 kA, and first measurements of divertor heat flux profiles in H-mode were made
International Nuclear Information System (INIS)
Sandoval V, S.; Mendoza E, P. R.; Gonzalez C, J. M.; Cecenas F, M.; Tijerina S, F.
2016-09-01
In response to the Fukushima Daiichi nuclear power plant accident, the NRC conducted an analysis and issued recommendations to improve the safety of the nuclear reactors. These include strengthening and integrating emergency response capabilities and emphasizing periodic staff training, the performance of simulation exercises. As a tool to observe these recommendations, the Graphic Console was developed for Analysis of Severe Accidents, Visualization of OEs, NAEs and calculation of the source term for nuclear power plant of Laguna Verde (NPP-LV ; CoGrAAS). The CoGrAAS is a computer system that displays in an integrated, graphic and dynamic way the information of a catalog of previously simulated accident scenarios. Has core mimics, vessel, primary containment and safety systems, trend graph of thermodynamic and radiological variables and the emergency procedures (OEs), chronological list of events, windows with detailed information for the dry-well, among others. The use of CoGrAAS allows that staff to understand and become familiar with the thermo-hydraulic progression of actual scenarios that exceed the design basis including those with core damage as severe accidents. The system enables personnel to develop an integral vision of the scenarios during the exercises and drills by observing and analyzing the evolution of the main reactor, core and primary containment variables, the response of emergency systems and the influence of that progression on OEs and the emergency action levels (NAEs). The CoGrAAS allows o observe the radiological variables and obtain the source term, to make the projection of doses, at any time within the scenario evolution. Thus, not only can the phenomenology of severe accidents be analyzed and understood, it is also possible to exercise, verify and evaluate the performance of critical tasks in the application of procedures, guidelines and emergency management plans. (Author)
The Electrochemical Behavior of Dispersions of Spherical Ultramicroelectrodes.
1986-07-30
means of bipolar electrolyses with dispersions. Polarization equations are predicted for highly simplified models based on the concept of the mixture...three-dimensional electrodes. Bipolar electrolyses on dispersions of spherical particles have been proposed and the behavior of such electrodes in the...photodecomposition of water (e.g. see (32-41)). It should be noted that the size range of the particles which will be most frequently used in dispersion
The spherical harmonics method, 1 (general development of the theory)
International Nuclear Information System (INIS)
Mark, C.
1957-02-01
A method of obtaining approximate solutions of the transport equation is presented in a form applicable in principle to any geometry. The approximation will give good results in cases where the angular distribution is not very anisotropic. The basis of the approximation is to expand the density per unit solid angle Ψ(→/r, →/Ω) in spherical harmonic tensors formed from →/Ω the unit vector in the direction of velocity, and to break off the expansion. A differential equation whose degree increases with the order of the approximation is obtained for the total density Ψ (o) (r). This equation has the form where the numbers ν i depend on the order of the approximation and on the value of the parameter a of the medium, but not at all on the geometry. When the equation for the total density is an ordinary equation, we simulate the physical condition of continuity of Ψ(→/r, →/Ω) at a boundary in a multi-medium problem by requiring that the spherical harmonic moments of Ψ(→/r, →/Ω) which we retain be continuous; and this determines the constants in the solution for Ψ (o) (→/r. The form of the solution for the total density and the necessary moments in an approximation of general order is given explicitly for plane and spherical symmetry; and for cylindrical symmetry the solution is given for two low-order approximations. In a later report (CRT-338, Revised) the application of the method to several problems involving plane and spherical symmetry will be discussed in detail and the results of a number of examples already worked will also be given. (author)
Decay of reverberant sound in a spherical enclosure
International Nuclear Information System (INIS)
Carroll, M.M.; Chien, C.F.
1977-01-01
The assumption of diffuse reflection (Lambert's Law) leads to integral equations for the wall intensity in a reverberant sound field in the steady state and during decay. The latter equation, in the special case of a spherical enclosure with uniformly absorbent walls and uniform wall intensity, allows exponential decay with a decay time which agrees closely with the Norris--Eyring prediction. The sound-intensity and sound-energy density in the medium, during decay, are also calculated
Exact Polynomial Eigenmodes for Homogeneous Spherical 3-Manifolds
Weeks, Jeffrey R.
2005-01-01
Observational data hints at a finite universe, with spherical manifolds such as the Poincare dodecahedral space tentatively providing the best fit. Simulating the physics of a model universe requires knowing the eigenmodes of the Laplace operator on the space. The present article provides explicit polynomial eigenmodes for all globally homogeneous 3-manifolds: the Poincare dodecahedral space S3/I*, the binary octahedral space S3/O*, the binary tetrahedral space S3/T*, the prism manifolds S3/D...
Dynamics and entanglement in spherically symmetric quantum gravity
International Nuclear Information System (INIS)
Husain, Viqar; Terno, Daniel R.
2010-01-01
The gravity-scalar field system in spherical symmetry provides a natural setting for exploring gravitational collapse and its aftermath in quantum gravity. In a canonical approach, we give constructions of the Hamiltonian operator, and of semiclassical states peaked on constraint-free data. Such states provide explicit examples of physical states. We also show that matter-gravity entanglement is an inherent feature of physical states, whether or not there is a black hole.
Attractive electromagnetic Casimir stress on a spherical dielectric shell
International Nuclear Information System (INIS)
Graham, N.; Quandt, M.; Weigel, H.
2013-01-01
Based on calculations involving an idealized boundary condition, it has long been assumed that the stress on a spherical conducting shell is repulsive. We use the more realistic case of a Drude dielectric to show that the stress is attractive, matching the generic behavior of Casimir forces in electromagnetism. We trace the discrepancy between these two cases to interactions between the electromagnetic quantum fluctuations and the dielectric material
Spherical fusion plasma-confinement field of Surmac type
Energy Technology Data Exchange (ETDEWEB)
Wipf, S.L.
1981-01-01
The concept of a Surmac confinement field that can be completely closed is presented. The internal conductor is magnetically suspended inside large corrugations of a superconducting spherical shell structure that carries the return current. Presently available superconductor technology using superfluid helium cooling allows fields above 1.5T throughout the wall region. Such a Surmac has potential for the study of advanced fuel cycles.
Effect of Fresnel Reflectivity in a Spherical Turbid Medium
Elghazaly, A
2003-01-01
Radiative transfer problem for anisotropic scattering in a spherical homogeneous, turbid medium with angular dependent (specular) reflecting boundary is solved using the pomraning-Eddington approximation method. The angular dependent reflectivity of the boundary is considered as Fresnel's reflection probability function. The partial heat flux is calculated with anisotropic scattering through a homogeneous solid sphere. our results are compared with the available data and give an excellent agreement.
Effect of Fresnel Reflectivity in a Spherical Turbid Medium
International Nuclear Information System (INIS)
Elghazaly, A.; Attia, M.T.
2003-01-01
Radiative transfer problem for anisotropic scattering in a spherical homogeneous, turbid medium with angular dependent (specular) reflecting boundary is solved using the pomraning-Eddington approximation method. The angular dependent reflectivity of the boundary is considered as Fresnel's reflection probability function. The partial heat flux is calculated with anisotropic scattering through a homogeneous solid sphere. our results are compared with the available data and give an excellent agreement
Characterization of Rubbers from Spherical Punch - Plate Indentation Tests
Directory of Open Access Journals (Sweden)
Florina Carmen Ciornei
2016-12-01
Full Text Available Rubber plates with different compositions and hardness were tested by continuous indentation, using a spherical punch and hysteretic phenomenon was evidenced. The experimental data interpolation with polynomial functions is accurate and permits estimation of the lost work during loading cycles. The interpolation by power law functions is more convenient by using less parameters and having a form accepted in literature. From the rubbers tested, two were considered to present good damping properties.