Sample records for ring circumference leads
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Lattice design for an ILC damping ring with 3 km circumference
International Nuclear Information System (INIS)
Wolski, Andrzej
2004-01-01
We describe a simple lattice that meets the specifications for the damping times and horizontal and longitudinal emittances for the International Linear Collider (ILC) damping rings. The circumference of a little over 3 km leads to a bunch spacing of around 3 ns, which will require advances in kicker technology for injection and extraction. We present the lattice design, and initial results of studies of the acceptance and collective effects. With the high bunch charge and close spacing, the ion and electron cloud effects are expected to be severe; however, the simple structure of the lattice allows for easy variation of the circumference and bunch spacing, which may make it useful for future investigations
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The short circumference damping ring design for the ILC
Korostelev, Maxim S; Kuriki, Masao; Kuroda, Shigeru; Naito, Takashi; Ross, Marc; Urakawa, Junji; Zimmermann, Frank
2005-01-01
The ILC damping ring tentative design is driven by the operational scenario of the main linac, the beam-dynamics demand of producing a stable and high-quality beam, the injection/extraction scheme and the kicker performance. In this paper, a short circumference damping ring design based on TME cells is described. The ring accommodates injection kickers which provide a flat top of 280 nsec and a 60 nsec rise and fall time and very fast strip-line kickers for beam extraction with a 2 nsec rise and fall time for 3-MHz operation. The potential impact of collective effects and the possible degradation of the dynamic aperture by nonlinear-wiggler fields are estimated.
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Mihn, Byeong-Hee; Choi, Goeun; Lee, Yong Sam
2017-03-01
This study examines the scale unique instruments used for astronomical observation during the Joseon dynasty. The Small Simplified Armillary Sphere (小簡儀, So-ganui) and the Sun-and-Stars Time-Determining Instrument (日星定時儀, Ilseong-jeongsi-ui) are minimized astronomical instruments, which can be characterized, respectively, as an observational instrument and a clock, and were influenced by the Simplified Armilla (簡儀, Jianyi) of the Yuan dynasty. These two instruments were equipped with several rings, and the rings of one were similar both in size and in scale to those of the other. Using the classic method of drawing the scale on the circumference of a ring, we analyze the scales of the Small Simplified Armillary Sphere and the Sun-and-Stars Time-Determining Instrument. Like the scale feature of the Simplified Armilla, we find that these two instruments selected the specific circumference which can be drawn by two kinds of scales. If Joseon`s astronomical instruments is applied by the dual scale drawing on one circumference, we suggest that 3.14 was used as the ratio of the circumference of circle, not 3 like China, when the ring`s size was calculated in that time. From the size of Hundred-interval disk of the extant Simplified Sundial in Korea, we make a conclusion that the three rings` diameter of the Sun-and-Stars Time-Determining Instrument described in the Sejiong Sillok (世宗實錄, Veritable Records of the King Sejong) refers to that of the middle circle of every ring, not the outer circle. As analyzing the degree of 28 lunar lodges (lunar mansions) in the equator written by Chiljeongsan-naepyeon (七政算內篇, the Inner Volume of Calculation of the Motions of the Seven Celestial Determinants), we also obtain the result that the scale of the Celestial-circumference-degree in the Small Simplified Armillary Sphere was made with a scale error about 0.1 du in root mean square (RMS).
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Directory of Open Access Journals (Sweden)
Byeong-Hee Mihn
2017-03-01
Full Text Available This study examines the scale unique instruments used for astronomical observation during the Joseon dynasty. The Small Simplified Armillary Sphere (小簡儀, So-ganui and the Sun-and-Stars Time-Determining Instrument (日星定時儀, Ilseong-jeongsi-ui are minimized astronomical instruments, which can be characterized, respectively, as an observational instrument and a clock, and were influenced by the Simplified Armilla (簡儀, Jianyi of the Yuan dynasty. These two instruments were equipped with several rings, and the rings of one were similar both in size and in scale to those of the other. Using the classic method of drawing the scale on the circumference of a ring, we analyze the scales of the Small Simplified Armillary Sphere and the Sun-and-Stars Time-Determining Instrument. Like the scale feature of the Simplified Armilla, we find that these two instruments selected the specific circumference which can be drawn by two kinds of scales. If Joseon’s astronomical instruments is applied by the dual scale drawing on one circumference, we suggest that 3.14 was used as the ratio of the circumference of circle, not 3 like China, when the ring’s size was calculated in that time. From the size of Hundred-interval disk of the extant Simplified Sundial in Korea, we make a conclusion that the three rings’ diameter of the Sun-and-Stars Time-Determining Instrument described in the Sejiong Sillok (世宗實錄, Veritable Records of the King Sejong refers to that of the middle circle of every ring, not the outer circle. As analyzing the degree of 28 lunar lodges (lunar mansions in the equator written by Chiljeongsan-naepyeon (七政算內篇, the Inner Volume of Calculation of the Motions of the Seven Celestial Determinants, we also obtain the result that the scale of the Celestial-circumference-degree in the Small Simplified Armillary Sphere was made with a scale error about 0.1 du in root mean square (RMS.
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Energy Technology Data Exchange (ETDEWEB)
Van Duyse, H [INIEX
1978-01-01
Tests 54 and 55 were carried out on rings made up of the usual type of panel. Test 54 involved panels manufactured at Zolder and Test 55 involved those manufactured at Beringen. Both types of ring are 20 cm thick, 64 cm wide and have an internal diameter of 4.20 m. The tests involved application of pressure to one quarter of the circumference, the remainder of the ring being subject to restraint against the steel testing frame. Timber chocks were inserted between the ring and the frame. The reinforcements tested were those used with the normal type of panel. An account of deformation of the ring, cracking of the panels, and deformation of the concrete is given. Tables and figures summarizing the results achieved are included. Maximum load prior to breaking was 292 t in the case of the Zolder ring and 293 t in the case of the Beringen ring; initial cracking occurred at 35 and 30 t, respectively. (In French and in Dutch)
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International Nuclear Information System (INIS)
Basu, C.; Gu Benyuan.
1994-12-01
We present the quantum mechanical calculations on the conductance of a quantum waveguide consisting of multiply connected mesoscopic rings with disordered ring-circumferences and ballistic lead connections between the rings with the transfer matrix approach. The profiles of the conductance as functions of the magnetic flux and the Fermi wave number of electrons depend on the number of rings as also on the geometric configuration of the system. The conductance spectrum of this system for disordered ring circumferences, disordered ring intervals and disordered magnetic flux is examined in detail. Studying the effect of geometric scattering and the two different length scales involved in the network, namely, the ring circumference and the ballistic lead connections on the conductance profile, we find that there exist two kinds of mini-bands, one originating from the bound states of the rings, i.e. the intrinsic mini-bands, and the other associated with the connecting leads between the adjacent rings, which are the extra mini-bands. These two kinds of mini-bands respond differently to external perturbations in parameters. Unlike the system of potential scatterers, this system of geometric scatterers show complete band formations at all energies even for finite systems and there is a preferential decay of the energy states depending upon the type of disorder introduced. The conductance band structures strongly depend on the geometric configuration of the network and so by controlling the geometric parameters, the conductance band structures can be artificially tailored. (author). 18 refs, 6 figs
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Heavier smoking may lead to a relative increase in waist circumference
DEFF Research Database (Denmark)
Morris, Richard W; Taylor, Amy E; Fluharty, Meg E
2015-01-01
in the CHRNA5-CHRNA3-CHRNB4 gene region) as a proxy for smoking heaviness, of the associations of smoking heaviness with a range of adiposity phenotypes. PARTICIPANTS: 148,731 current, former and never-smokers of European ancestry aged ≥ 16 years from 29 studies in the consortium for Causal Analysis Research...... in Tobacco and Alcohol (CARTA). PRIMARY OUTCOME MEASURES: Waist and hip circumferences, and waist-hip ratio. RESULTS: The data included up to 66,809 never-smokers, 43,009 former smokers and 38,913 current daily cigarette smokers. Among current smokers, for each extra minor allele, the geometric mean...... was lower for waist circumference by -0.40% (95% CI -0.57% to -0.22%), with effects on hip circumference, waist-hip ratio and body mass index (BMI) being -0.31% (95% CI -0.42% to -0.19), -0.08% (-0.19% to 0.03%) and -0.74% (-0.96% to -0.51%), respectively. In contrast, among never-smokers, these effects...
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Dynamic apeerture in damping rings with realistic wigglers
Energy Technology Data Exchange (ETDEWEB)
Cai, Yunhai; /SLAC
2005-05-04
The International Linear Collider based on superconducting RF cavities requires the damping rings to have extremely small equilibrium emittance, huge circumference, fast damping time, and large acceptance. To achieve all of these requirements is a very challenging task. In this paper, we will present a systematic approach to designing the damping rings using simple cells and non-interlaced sextupoles. The designs of the damping rings with various circumferences and shapes, including dogbone, are presented. To model realistic wigglers, we have developed a new hybrid symplectic integrator for faster and accurate evaluation of dynamic aperture of the lattices.
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Monahan, William B; Pereira, Ricardo J; Wake, David B
2012-03-12
In the mid 20th century, Ernst Mayr and Theodosius Dobzhansky championed the significance of circular overlaps or ring species as the perfect demonstration of speciation, yet in the over 50 years since, only a handful of such taxa are known. We developed a topographic model to evaluate whether the geographic barriers that favor processes leading to ring species are common or rare, and to predict where other candidate ring barriers might be found. Of the 952,147 geographic barriers identified on the planet, only about 1% are topographically similar to barriers associated with known ring taxa, with most of the likely candidates occurring in under-studied parts of the world (for example, marine environments, tropical latitudes). Predicted barriers separate into two distinct categories: (i) single cohesive barriers (barriers - formed by groups of barriers (each 184,000 to 1.7 million km2) in close geographic proximity (totaling 1.9 to 2.3 million km2) - associated with taxa that differentiate at larger spatial scales (birds: Phylloscopus trochiloides and Larus (sp. argentatus and fuscus)). When evaluated globally, we find a large number of cohesive barriers that are topographically similar to those associated with known ring taxa. Yet, compared to cohesive barriers, an order of magnitude fewer composite barriers are similar to those that favor ring divergence in species with higher dispersal. While these findings confirm that the topographic conditions that favor evolutionary processes leading to ring speciation are, in fact, rare, they also suggest that many understudied natural systems could provide valuable demonstrations of continuous divergence towards the formation of new species. Distinct advantages of the model are that it (i) requires no a priori information on the relative importance of features that define barriers, (ii) can be replicated using any kind of continuously distributed environmental variable, and (iii) generates spatially explicit hypotheses of
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Small electrostatic storage rings; also for highly charged ions?
International Nuclear Information System (INIS)
Moeller, S.P.; Pedersen, U.V.
2001-01-01
Two years ago, a small electrostatic storage ring ELISA (electrostatic ion storage ring, Aarhus) was put into operation. The design of this small 7 m circumference ring was based on electrostatic deflection plates and quadrupoles. This is in contrast to the larger ion storage rings, which are based on magnetic focusing and deflection. The result is a small, relatively inexpensive, storage ring being able to store ions of any mass and any charge at low energy ( -11 mbar resulting in storage times of several tens of seconds for singly charged ions. The maximum number of singly charged ions that can be stored is a few 10 7 . Several experiments have already been performed in ELISA. These include lifetime studies of metastable ions and studies of fullerenes and metal-cluster ions. Lasers are also used for excitation of the circulating ions. Heating/cooling of the ring is possible. Cooling of the ring leads to significantly lower pressures, and correspondingly longer lifetimes. A change of the temperature of the vacuum chambers surrounding the ion beam also leads to a change of the spectrum of the black-body radiation, which has a significant influence on weakly bound negative ions. At the time of writing, at least two other electrostatic storage rings are being built, and more are planned. In the following, the electrostatic storage ring ELISA will be described, and results from some of the initial experiments demonstrating the performance will be shown. The relative merits of such a ring, as opposed to the larger magnetic rings and the smaller ion traps will be discussed. The potential for highly charged ions will be briefly mentioned. (orig.)
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Directory of Open Access Journals (Sweden)
Monahan William B
2012-03-01
Full Text Available Abstract Background In the mid 20th century, Ernst Mayr and Theodosius Dobzhansky championed the significance of circular overlaps or ring species as the perfect demonstration of speciation, yet in the over 50 years since, only a handful of such taxa are known. We developed a topographic model to evaluate whether the geographic barriers that favor processes leading to ring species are common or rare, and to predict where other candidate ring barriers might be found. Results Of the 952,147 geographic barriers identified on the planet, only about 1% are topographically similar to barriers associated with known ring taxa, with most of the likely candidates occurring in under-studied parts of the world (for example, marine environments, tropical latitudes. Predicted barriers separate into two distinct categories: (i single cohesive barriers (2, associated with taxa that differentiate at smaller spatial scales (salamander: Ensatina eschscholtzii; tree: Acacia karroo; and (ii composite barriers - formed by groups of barriers (each 184,000 to 1.7 million km2 in close geographic proximity (totaling 1.9 to 2.3 million km2 - associated with taxa that differentiate at larger spatial scales (birds: Phylloscopus trochiloides and Larus (sp. argentatus and fuscus. When evaluated globally, we find a large number of cohesive barriers that are topographically similar to those associated with known ring taxa. Yet, compared to cohesive barriers, an order of magnitude fewer composite barriers are similar to those that favor ring divergence in species with higher dispersal. Conclusions While these findings confirm that the topographic conditions that favor evolutionary processes leading to ring speciation are, in fact, rare, they also suggest that many understudied natural systems could provide valuable demonstrations of continuous divergence towards the formation of new species. Distinct advantages of the model are that it (i requires no a priori information on the
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Recommendation for the Feasibility of more Compact LC Damping Rings
Pivi, M.T.F.; Demma, T.; Guiducci, S.; Suetsugu, Y.; Shibata, K.; Ohmi, K.; Dugan, G.; Palmer, M.; Crittenden, J.A.; Harkay, K.; Boon, L.; Furman, M.A.; Venturini, M.; Celata, C.; Malyshev, O.B.; Papaphilippou, I.
2010-01-01
As part of the international Linear Collider (ILC) collaboration, we have compared the electron cloud (EC) effect for different Damping Ring (DR) designs respectively with 6.4 km and 3.2 km circumference and investigated the feasibility of the shorter damping ring with respect to the electron cloud build-up and related beam instabilities. The studies for a 3.2 km ring were carried out with beam parameters of the ILC Low Power option. A reduced damping ring circumference has been proposed for the new ILC baseline design SB2009 and would allow considerable reduction of the number of components, wiggler magnets and costs. We discuss the impact of the proposed operation of the ILC at high repetition rate 10 Hz and address the necessary modifications for the DRs. We also briefly discuss the plans for future studies including the luminosity upgrade option with shorter bunch spacing, the evaluation of mitigation techniques and the integration of the CesrTA results into the Damping Ring design
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Recommendation for the Feasibility of more Compact LC Damping Rings
International Nuclear Information System (INIS)
Pivi, M.T.F.; Wang, L.; Demma, T.; Guiducci, S.; Suetsugu, Y.; Shibata, K.; Ohmi, K.; Dugan, G.; Palmer, M.; Crittenden, J.A.; Harkay, K.; Boon, L.; Furman, M.A.; Venturini, M.; Celata, C.; Malyshev, O.B.; Papaphilippou, I.
2010-01-01
As part of the international Linear Collider (ILC) collaboration, we have compared the electron cloud (EC) effect for different Damping Ring (DR) designs respectively with 6.4 km and 3.2 km circumference and investigated the feasibility of the shorter damping ring with respect to the electron cloud build-up and related beam instabilities. The studies for a 3.2 km ring were carried out with beam parameters of the ILC Low Power option. A reduced damping ring circumference has been proposed for the new ILC baseline design SB2009 (1) and would allow considerable reduction of the number of components, wiggler magnets and costs. We discuss the impact of the proposed operation of the ILC at high repetition rate 10 Hz and address the necessary modifications for the DRs. We also briefly discuss the plans for future studies including the luminosity upgrade option with shorter bunch spacing, the evaluation of mitigation techniques and the integration of the CesrTA results into the Damping Ring design.
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A numerical study of the quantum oscillations in multiple dangling rings
International Nuclear Information System (INIS)
Gu, B.Y.; Basu, C.
1994-12-01
We present the quantum mechanical calculations on magnetoconductance of the quantum waveguide topology containing multiply connected dangling mesoscopic rings with the transfer matrix approach. The profiles of the conductance as functions of the Fermi wave number of electrons and of the magnetic flux depend on the number of rings as also on the geometric configuration of the system. The conductance spectrum of this system for disordered lengths in the ring circumferences, dangling links, ballistic leads connecting consecutive dangling rings and disordered magnetic flux is examined in details. We find that there exist two kinds of mini-bands, one originating from the eigenstates of the rings, i.e. the intrinsic mini-bands, and the extra mini-bands. Some of these extra minibands are associated with the dangling links connecting the rings to the main quantum wire, while others are from the standing wave modes associated with the ballistic leads connecting adjacent dangling rings. These different kinds of mini-bands have completely different properties and responds differently to the geometric parameter fluctuations. Unlike the system of potential scatterers, this system of geometric scatterers shows complete band formations at all energies even for finite number of scatterers present. There is a preferential decay of the energy states, depending upon the type of disorder introduced. By controlling the geometric parameters, the conductance band structure of such a model can be artificially tailored and thus may guide the design of better mesoscopic switching devices. (author). 19 refs, 7 figs
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The LSU Electron Storage Ring, the first commercially-built storage ring
International Nuclear Information System (INIS)
Sah, R.
1990-01-01
The Brobeck Division of Maxwell Laboratories, Inc., is building the first industrially-produced storage ring. It will be located at Louisiana State University (LSU) at the Center for Advanced Microstructures and Devices (CAMD) in Baton Rouge. The purpose of this electron storage ring is to provide intense beams of x-rays to advance the state-of-the-art in lithography and to permit research in a broad area. This facility consists of a 1.2 GeV, 400 mA electron storage ring with a 200 MeV linac injector. The magnet lattice is a Chasman-Green design (double-bend achromat), and the ring circumference is 55.2 meters. There are four 3.0 meter, dispersion-free straight sections, one for injection, one for the 500 MHz RF cavity, and two for possible future insertion devices. The storge ring construction project is in the detailed-design stage, and many systems are in the initial stages of fabrication. 4 figs., 1 tab
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Conductance of closed and open long Aharonov-Bohm-Kondo rings
Shi, Zheng; Komijani, Yashar
2017-02-01
We calculate the finite temperature linear dc conductance of a generic single-impurity Anderson model containing an arbitrary number of Fermi liquid leads, and apply the formalism to closed and open long Aharonov-Bohm-Kondo (ABK) rings. We show that, as with the short ABK ring, there is a contribution to the conductance from the connected four-point Green's function of the conduction electrons. At sufficiently low temperatures this contribution can be eliminated, and the conductance can be expressed as a linear function of the T matrix of the screening channel. For closed rings we show that at temperatures high compared to the Kondo temperature, the conductance behaves differently for temperatures above and below vF/L , where vF is the Fermi velocity and L is the circumference of the ring. For open rings, when the ring arms have both a small transmission and a small reflection, we show from the microscopic model that the ring behaves like a two-path interferometer, and that the Kondo temperature is unaffected by details of the ring. Our findings confirm that ABK rings are potentially useful in the detection of the size of the Kondo screening cloud, the π /2 scattering phase shift from the Kondo singlet, and the suppression of Aharonov-Bohm oscillations due to inelastic scattering.
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Viktorovich Tchernyi, Vladimir
2018-06-01
Saturn Rings Origin: Quantum Trapping of Superconducting Iced Particles and Meissner Effect Lead to the Stable Rings System Vladimir V. Tchernyi (Cherny), Andrew Yu. Pospelov Modern Science Institute, SAIBR, Moscow, Russia. E-mail: chernyv@bk.ruAbstractIt is demonstrated how superconducting iced particles of the protoplanetary cloud of Saturn are coming to magnetic equator plane and create the stable enough rings disk. There are two steps. First, after appearance of the Saturn magnetic field due to Meissner phenomenon all particles orbits are moving to the magnetic equator plane. Finally they become distributed as rings and gaps like iron particles around magnet on laboratory table. And they are separated from each other by the magnetic field expelled from them. It takes up to few tens of thousands years with ten meters rings disk thickness. Second, due to their quantum trapping all particles become to be trapped within magnetic well at the magnetic equator plane due to Abrikosov vortex for superconductor. It works even when particles have small fraction of superconductor. During the rings evolution some contribution to the disk also could come from the collision-generated debris of the current moon and from the geysers like it happened due to magnetic coupling of Saturn and Enceladus. The rings are relict of the early days of the magnetic field of Saturn system.
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The Cryogenic Storage Ring CSR
von Hahn, Robert; Becker, Arno; Berg, Felix; Blaum, Klaus; Breitenfeldt, Christian; Fadil, Hisham; Fellenberger, Florian; Froese, Michael; George, Sebastian; Göck, Jürgen; Grieser, Manfred; Grussie, Florian; Guerin, Elisabeth A.; Heber, Oded; Herwig, Philipp
2016-01-01
An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion a...
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Lattice design of HISTRAP: Heavy ion storage ring for atomic physics
International Nuclear Information System (INIS)
Lee, I.Y.; Martin, J.A.; McGrory, J.B.; Milner, W.T.; Olsen, D.K.; Young, G.R.
1987-01-01
HISTRAP, a Heavy-Ion Storage Ring for Atomic Physics, is a proposed 46.8-m-circumference synchrotron-cooling-storage ring optimized to accelerate, cool, decelerate, and store beams of highly charged very-heavy ions at energies appropriate for advanced atomic physics research. This four-fold symmetrical ring has a maximum bending power of 2 Tm. It has achromatic bends and uses quadrupole triplets for focusing
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Project of the compact superconducting storage ring Siberia-SM
Energy Technology Data Exchange (ETDEWEB)
Anashin, V V; Arbuzov, V S; Blinov, G A; Veshcherevich, V G; Vobly, P D; Gorniker, E I; Zinevich, N I; Zinin, E I; Zubkov, N I; Kiselev, V A; Kollerov, E P; Kulipanov, G N; Matveev, Yu G; Medvedko, A S; Mezentsev, N A; Morgunov, L G; Petrov, V M; Petrov, S P; Repkov, V V; Roenko, V A; Skrinsky, A N; Sukhanov, S V; Tokarev, Yu I; Trakhtenberg, E M [AN SSSR, Novosibirsk. Inst. Yadernoj Fiziki
1989-10-10
In the last decade researches dealing with the creation of technology for X-ray lithography and for appropriate production equipment have been performed in many countries. The basic aim of these works is to provide a mass production of inexpensive devices with submicron structures (0.7-0.1 {mu}m). Bringing X-ray lithographic technology into commercial practice necessitates to design and build a dedicated SR source for the electronic industry. The use of superconducting bending magnets with 40-70 kG field strength enables the storage ring circumference to be reduced by a factor of 2-5 and the injection energy by a factor of 3-4 as compared to the conventional designs of storage rings. In the present paper we consider a storage ring which was designed for a maximum energy of 600 MeV, with 60 kG field strength in its bending magnets and 10 m circumference. The critical SR wavelength is 8.6 A. The electrons are injected into the storage ring at 50-60 MeV and the maximum stored current is assumed to be equal to 0.3 A. (orig.).
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Variable area manifolds for ring mirror heat exchangers
Eng, Albert; Senterfitt, Donald R.
1988-05-01
A laser ring mirror assembly is disclosed which supports and cools an annular ring mirror of a high powered laser with a cooling manifold which has a coolant flow design which is intended to reduce thermal distortions of the ring mirror by minimizing azimuthal variations in temperature around its circumference. The cooling manifold has complementary pairs of cooling passages each of which conduct coolant in opposite flow directions. The manifold also houses adjusters which vary the depth between the annular ring mirror and each cooling, and which vary the flow area of the cooling passage to produce a control over the cooling characteristics of the cooling manifold.
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Survey and alignment of the Fermilab recycler antiproton storage ring
International Nuclear Information System (INIS)
Arics, Babatunde O.O.
1999-01-01
In June of 1999 Fermilab commissioned a newly constructed antiproton storage ring, the 'Recycler Ring', in the Main Injector tunnel directly above the Main Injector beamline. The Recycler Ring is a fixed 8 GeV kinetic energy storage ring and is constructed of strontium ferrite permanent magnets. The 3319.4-meter-circumference Recycler Ring consists of 344 gradient magnets and 100 quadrupoles all of which are permanent magnets. This paper discusses the methods employed to survey and align these permanent magnets within the Recycler Ring with the specified accuracy. The Laser Tracker was the major instrument used for the final magnet alignment. The magnets were aligned along the Recycler Ring with a relative accuracy of ±0.25 mm. (author)
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Change in neck circumference after shoulder arthroscopy: An observational study
Directory of Open Access Journals (Sweden)
Shrividya Chellam
2015-01-01
Full Text Available Background and Aims: Shoulder arthroscopy requires fluid irrigation, which causes soft-tissue oedema around chest, neck, and arm intraoperatively, leading to postoperative airway complications. We decided to study the incidence of increase in the neck circumference in shoulder arthroscopy and its effects on the airway. Methods: We studied 32 cases of shoulder arthroscopies over a period of 1-year, performed under general anaesthesia with interscalene block. The neck circumference of patients before and after the procedure was measured along with other parameters. The endotracheal tube cuff was deflated at the end of surgery to determine air leak around the tube. The negative leak test suggested airway oedema. Results: Thirty out of 32 patients showed positive air leak test. The average change in neck circumference was 1.17 ± 1.16 cm and all could be extubated uneventfully. Two showed negative leak test with an increase in neck circumference by 4.5 and 6.4 cm and were not extubated. Multiple regression analysis for risk factors showed intraoperative hypertension as a single predictor for an increase in neck circumference. Conclusion: Change in the neck circumference beyond 4 cm may suggest airway compromise and below 4 cm, airway compromise is unlikely even in the presence of extensive soft-tissue oedema around the shoulder, upper arm and chest.
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The positron accumulator ring for the APS
International Nuclear Information System (INIS)
Crosbie, E.A.
1989-01-01
The Positron Accumulator Ring (PAR) is designed to accumulate and damp positrons from the 450-MeV linac during the 0.5-s cycle time of the injector synchrotron for the APS 7-GeV storage ring. During 0.4 s of each synchrotron cycle, up to 24 linac pulses are injected into the horizontal phase space of the PAR at a 60-Hz rate. Each injected pulse occupies about 1.3 of the circumference of the accumulator ring. After 0.1 s for longitudinal damping, the single accumulated bunch is transferred to one of the 353-MHz buckets of the injector synchrotron RF system. The bunch is accelerated to 7 GeV and transferred to the storage ring, while the PAR accumulates the next bunch of positrons. 2 refs., 3 figs., 2 tabs
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The positron accumulator ring for the APS
International Nuclear Information System (INIS)
Crosbie, E.A.
1989-01-01
The Positron Accumulator Ring (PAR) is designed to accumulate and damp positrons from the 450-MeV linac during the 0.5-s cycle time of the injector synchrotron for the APS 7-GeV storage ring. During 0.4 s of each synchrotron cycle, up to 24 linac pulses are injected into the horizontal phase space of the PAR at a 60-Hz rate. Each injected pulse occupies about 1/3 of the circumference of the accumulator ring. After 0.1 s for longitudinal damping, the single accumulated bunch is transferred to one of the 353-MHz buckets of the injector synchrotron RF system. The bunch is accelerated to 7 GeV and transferred to the storage ring, while the PAR accumulates the next bunch of positrons. 2 refs., 3 figs., 2 tabs
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Olive tree-ring problematic dating: a comparative analysis on Santorini (Greece.
Directory of Open Access Journals (Sweden)
Paolo Cherubini
Full Text Available Olive trees are a classic component of Mediterranean environments and some of them are known historically to be very old. In order to evaluate the possibility to use olive tree-rings for dendrochronology, we examined by various methods the reliability of olive tree-rings identification. Dendrochronological analyses of olive trees growing on the Aegean island Santorini (Greece show that the determination of the number of tree-rings is impossible because of intra-annual wood density fluctuations, variability in tree-ring boundary structure, and restriction of its cambial activity to shifting sectors of the circumference, causing the tree-ring sequences along radii of the same cross section to differ.
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Olive tree-ring problematic dating: a comparative analysis on Santorini (Greece).
Cherubini, Paolo; Humbel, Turi; Beeckman, Hans; Gärtner, Holger; Mannes, David; Pearson, Charlotte; Schoch, Werner; Tognetti, Roberto; Lev-Yadun, Simcha
2013-01-01
Olive trees are a classic component of Mediterranean environments and some of them are known historically to be very old. In order to evaluate the possibility to use olive tree-rings for dendrochronology, we examined by various methods the reliability of olive tree-rings identification. Dendrochronological analyses of olive trees growing on the Aegean island Santorini (Greece) show that the determination of the number of tree-rings is impossible because of intra-annual wood density fluctuations, variability in tree-ring boundary structure, and restriction of its cambial activity to shifting sectors of the circumference, causing the tree-ring sequences along radii of the same cross section to differ.
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International Nuclear Information System (INIS)
Patrick, Gavin J.; Farmer, John G.
2006-01-01
The validity of the use of sycamore (Acer pseudoplatanus) tree-rings for the reconstruction of atmospheric lead pollution histories was investigated. Tree cores spanning 1892-2003 were collected from several sycamores from the eastern shore of Loch Lomond, Scotland, an area with no local point sources of lead emission. The lead concentration and 206 Pb/ 207 Pb profiles of the Loch Lomond region cores were compared with corresponding data for the 21 Pb-dated loch sediment, and also with data for moss of known age from a Scottish herbarium collection. Two of the seven sycamore cores showed the same lead concentration trend as the lead flux to the loch, the rest having no similarity to either each other or the loch sediment record. Two further sycamore cores showed some similarity in their temporal 206 Pb/ 207 Pb trends to those seen in the sediment and moss records, but only in part of their profiles, whilst the 206 Pb/ 207 Pb ratios of the other sycamore cores remained relatively unchanged for the majority of the time covered, or exhibited an opposite trend. The 206 Pb/ 207 Pb ratios of the tree cores were also mostly higher than those of the previously established records for any given time period. Tree cores covering 1878-2002 were also collected along transects from Wanlockhead and Tyndrum, two areas of former lead mining and smelting associated with distinct 206 Pb/ 207 Pb ratios of 1.170 and 1.144, respectively. The Wanlockhead tree cores exhibited a generally decreasing trend in lead concentration with both time and distance from the lead mine. The characteristic 206 Pb/ 207 Pb ratio of 1.170 was observed in samples close to the mine but a decrease in the influence of the mine-derived lead was observed in more distant samples. The tree sampled at Tyndrum showed elevated lead concentrations, which decreased with time, and a fairly constant 206 Pb/ 207 Pb ratio of ∼ 1.15 reflecting input from the mine, features not observed in any other trees along the
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International Nuclear Information System (INIS)
Fischer, W.
2010-01-01
Storage rings are circular machines that store particle beams at a constant energy. Beams are stored in rings without acceleration for a number of reasons (Tab. 1). Storage rings are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage rings such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage ring but may not be extracted (Fig. 1). Accelerator rings such as synchrotrons are used as storage rings before and after acceleration. Particles stored in rings include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10 -6 eV to 3.5 x 10 12 eV (LHC, 7 x 10 12 eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in rings requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage rings. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or positron beams
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Cooldown and warmup computer simulations of the SSC ring
International Nuclear Information System (INIS)
Carcagno, R.H.; Schiesser, W.E.; Yuecel, A.
1991-06-01
The Superconducting Super Collider (SSC) consists of two stacked rings of superconducting magnets; each ring is about 86 km in circumference. The total mass to be cooled to liquid helium temperature amounts to about 1 x 10 8 kg, and the total helium inventory under nominal operating conditions (4.15 K and 4 atm) is about 2.8 x 10 5 kg. The cooldown and warmup process of a long string of magnets has to be well understood in order to design a cryogenic system that can satisfy the requirements of helium inventory handling, magnet temperature gradients, and process time for the different cooldown and warmup scenarios being planned for the SSC. A system that can be convincingly simulated can be understood, controlled, operated and improved in a systematic way. In this paper, we introduce two numerical models, a lumped model and a distributed model, for cooldown and warmup of the SSC ring, and present simulation results for an SSC string (4320 m long, or 1/20th of the full ring circumference). The models cover the temperature range between room and liquid helium temperature; the distributed model includes radial temperature distribution in the cold mass. Low temperature range simulations are particularly important to study inventory handling strategies because of the relationship between rapid changes in density and the system mass flow rate. 9 refs., 9 figs
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Mihn, Byeong-Hee; Lee, Ki-Won; Ahn, Young Sook; Lee, Yong Sam
2015-03-01
During the reign of King Sejong (世宗, 1418-1450) in the Joseon Dynasty, there were lots of astronomical instruments, including miniaturized ones. Those instruments utilized the technical know-how acquired through building contemporary astronomical instruments previously developed in the Song(宋), Jin(金), and Yuan(元) dynasties of China. In those days, many astronomical instruments had circles, rings, and spheres carved with a scale of 365.25, 100, and 24 parts, respectively, on their circumference. These were called the celestial-circumference degree, hundred-interval (Baekgak), and 24 direction, respectively. These scales are marked by the angular distance, not by the angle. Therefore, these circles, rings, and spheres had to be optimized in size to accomodate proper scales. Assuming that the scale system is composed of integer multiples of unit length, we studied the sizes of circles by referring to old articles and investigating existing artifacts. We discovered that the star chart of Cheonsang yeolcha bunyajido was drawn with a royal standard ruler (周尺) based on the unit length of 207 mm. Interestingly, its circumference was marked by the unit scale of 3 puns per 1 du (or degree) like Honsang (a celestial globe). We also found that Hyeonju ilgu (a equatorial sundial) has a Baekgak disk on a scale of 1 pun per 1 gak (that is an interval of time similar to a quarter). This study contributes to the analysis of specifications of numerous circular elements from old Korean astronomical instruments.
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Piezoelectric Lead Zirconate Titanate (PZT) Ring Shaped Contour-Mode MEMS Resonators
Kasambe, P. V.; Asgaonkar, V. V.; Bangera, A. D.; Lokre, A. S.; Rathod, S. S.; Bhoir, D. V.
2018-02-01
Flexibility in setting fundamental frequency of resonator independent of its motional resistance is one of the desired criteria in micro-electromechanical (MEMS) resonator design. It is observed that ring-shaped piezoelectric contour-mode MEMS resonators satisfy this design criterion than in case of rectangular plate MEMS resonators. Also ring-shaped contour-mode piezoelectric MEMS resonator has an advantage that its fundamental frequency is defined by in-plane dimensions, but they show variation of fundamental frequency with different Platinum (Pt) thickness referred as change in ratio of fNEW /fO . This paper presents the effects of variation in geometrical parameters and change in piezoelectric material on the resonant frequencies of Platinum piezoelectric-Aluminium ring-shaped contour-mode MEMS resonators and its electrical parameters. The proposed structure with Lead Zirconate Titanate (PZT) as the piezoelectric material was observed to be a piezoelectric material with minimal change in fundamental resonant frequency due to Platinum thickness variation. This structure was also found to exhibit extremely low motional resistance of 0.03 Ω as compared to the 31-35 Ω range obtained when using AlN as the piezoelectric material. CoventorWare 10 is used for the design, simulation and corresponding analysis of resonators which is Finite Element Method (FEM) analysis and design tool for MEMS devices.
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Energy Technology Data Exchange (ETDEWEB)
Patrick, Gavin J. [School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, Scotland (United Kingdom); Farmer, John G. [School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, Scotland (United Kingdom)]. E-mail: J.G.Farmer@ed.ac.uk
2006-06-01
The validity of the use of sycamore (Acer pseudoplatanus) tree-rings for the reconstruction of atmospheric lead pollution histories was investigated. Tree cores spanning 1892-2003 were collected from several sycamores from the eastern shore of Loch Lomond, Scotland, an area with no local point sources of lead emission. The lead concentration and {sup 206}Pb/{sup 207}Pb profiles of the Loch Lomond region cores were compared with corresponding data for the {sup 21}Pb-dated loch sediment, and also with data for moss of known age from a Scottish herbarium collection. Two of the seven sycamore cores showed the same lead concentration trend as the lead flux to the loch, the rest having no similarity to either each other or the loch sediment record. Two further sycamore cores showed some similarity in their temporal {sup 206}Pb/{sup 207}Pb trends to those seen in the sediment and moss records, but only in part of their profiles, whilst the {sup 206}Pb/{sup 207}Pb ratios of the other sycamore cores remained relatively unchanged for the majority of the time covered, or exhibited an opposite trend. The {sup 206}Pb/{sup 207}Pb ratios of the tree cores were also mostly higher than those of the previously established records for any given time period. Tree cores covering 1878-2002 were also collected along transects from Wanlockhead and Tyndrum, two areas of former lead mining and smelting associated with distinct {sup 206}Pb/{sup 207}Pb ratios of 1.170 and 1.144, respectively. The Wanlockhead tree cores exhibited a generally decreasing trend in lead concentration with both time and distance from the lead mine. The characteristic {sup 206}Pb/{sup 207}Pb ratio of 1.170 was observed in samples close to the mine but a decrease in the influence of the mine-derived lead was observed in more distant samples. The tree sampled at Tyndrum showed elevated lead concentrations, which decreased with time, and a fairly constant {sup 206}Pb/{sup 207}Pb ratio of {approx} 1.15 reflecting input
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Directory of Open Access Journals (Sweden)
Byeong-Hee Mihn
2015-03-01
Full Text Available During the reign of King Sejong (世宗, 1418-1450 in the Joseon Dynasty, there were lots of astronomical instruments, including miniaturized ones. Those instruments utilized the technical know-how acquired through building contemporary astronomical instruments previously developed in the Song(宋, Jin(金, and Yuan(元 dynasties of China. In those days, many astronomical instruments had circles, rings, and spheres carved with a scale of 365.25, 100, and 24 parts, respectively, on their circumference. These were called the celestial-circumference degree, hundred-interval (Baekgak, and 24 direction, respectively. These scales are marked by the angular distance, not by the angle. Therefore, these circles, rings, and spheres had to be optimized in size to accomodate proper scales. Assuming that the scale system is composed of integer multiples of unit length, we studied the sizes of circles by referring to old articles and investigating existing artifacts. We discovered that the star chart of Cheonsang yeolcha bunyajido was drawn with a royal standard ruler (周尺 based on the unit length of 207 mm. Interestingly, its circumference was marked by the unit scale of 3 puns per 1 du (or degree like Honsang (a celestial globe. We also found that Hyeonju ilgu (a equatorial sundial has a Baekgak disk on a scale of 1 pun per 1 gak (that is an interval of time similar to a quarter. This study contributes to the analysis of specifications of numerous circular elements from old Korean astronomical instruments.
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Device for monitoring electron-ion ring parameters
International Nuclear Information System (INIS)
Tyutyunnikov, S.I.; Shalyapin, V.N.
1982-01-01
The invention is classified as the method of collective ion acceleration. The device for electron-ion ring parameters monitoring is described. The invention is aimed at increasing functional possibilities of the device at the expense of the enchance in the number of the ring controlled parameters. The device comprises three similar plane mirrors installed over accelerating tube circumference and a mirror manufactured in the form of prism and located in the tube centre, as well as the system of synchrotron radiation recording and processing. Two plane mirrors are installed at an angle of 45 deg to the vertical axis. The angle of the third plane mirror 3 α and that of prismatic mirror 2 α to the vertical axis depend on geometric parameters of the ring and accelerating tube and they are determined by the expression α=arc sin R K /2(R T -L), where R K - ring radius, R T - accelerating tube radius, L - the height of segment, formed by the mirror and inner surface of the accelerating tube. The device suggested permits to determine longitudinal dimensions of the ring, its velocity and the number of electrons and ions in the ring
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Design for ANL 7 GeV storage ring vacuum system
International Nuclear Information System (INIS)
Wehrle, R.B.; Nielsen, R.W.
1988-01-01
The 7-GeV Advanced Photon Source (APS) design includes a storage ring having a 1060-m circumference with the capability of accommodating 34 insertion devices (ID) and their associated photon beam lines. An additional 35 photon lines can be provided from bending magnets. The vacuum system for the storage ring is designed to maintain a beam-on operating pressure of 1n Torr or less to achieve a positron beam lifetime of approximately 20 hours. The vacuum system and it's current developmental status are described
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Kleinrouweler, C. E.; Kuijper, C. F.; van Zalen-Sprock, M. M.; Mathijssen, I. B.; Bilardo, C. M.; Pajkrt, E.
2011-01-01
To evaluate the outcome of fetuses with prenatally diagnosed omphalocele and to investigate the predictive value of the omphalocele circumference/abdominal circumference (OC/AC) ratio - a measure for the relative size of the omphalocele. This study includes all fetuses prenatally diagnosed with
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Low energy current accumulator for high-energy proton rings
International Nuclear Information System (INIS)
Month, M.
1977-01-01
Building current in high-energy p-p colliding beam machines is most appropriately done in a low-energy (small circumference) current accumulator. Three significant factors favor such a procedure: First, large rings tend to be susceptible to unstable longitudinal density oscillations. These can be avoided by pumping up the beam in the accumulator. When the current stack is injected into the storage ring, potentially harmful instability is essentially neutralized. Second, high-field magnets characteristic of future high energy proton rings are designed with superconducting coils within the iron magnetic shield. This means coil construction and placement errors propagate rapidly within the beam aperture. An intermediate ''stacking ring'' allows the minimum use of the superconducting ring aperture. Finally, the coils are vulnerable to radiation heating and possible magnet quenching. By minimizing beam manipulaion in the superconducting environment and using only the central portion of the beam aperture, coil vulnerability can be put at a minimum
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A study for lattice comparison for PLS 2 GeV storage ring
International Nuclear Information System (INIS)
Yoon, M.
1991-01-01
TBA and DBA lattices are compared for 1.5-2.5 GeV synchrotron light source, with particular attention to the PLS 2 GeV electron storage ring currently being developed in Pohang, Korea. For the comparison study, the optimum electron energy was chosen to be 2 GeV and the circumference of the ring is less than 280.56 m, the natural beam emittance no greater than 13 nm. Results from various linear and nonlinear optics comparison studies are presented
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From bicycle chain ring shape to gear ratio: algorithm and examples.
van Soest, A J
2014-01-03
A simple model of the bicycle drive system with a non-circular front chain ring is proposed and an algorithm is devised for calculation of the corresponding Gear Ratio As a Function Of Crank Angle (GRAFOCA). It is shown that the true effective radius of the chain ring is always the perpendicular distance between the crank axis and the line through the chain segment between the chain ring and the cog. It is illustrated that the true effective radius of the chain ring at any crank angle may differ substantially from the maximum vertical distance between the crank axis and the chain ring circumference that is used as a proxy for the effective chain ring radius in several studies; in particular, the crank angle at which the effective chain ring radius is maximal as predicted from the latter approach may deviate by as much as 0.30 rad from the true value. The algorithm proposed may help in designing chain rings that achieve the desired GRAFOCA. © 2013 Published by Elsevier Ltd. All rights reserved.
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Status of the Frankfurt low energy electrostatic storage ring (FLSR)
King, F.; Kruppi, T.; Müller, J.; Dörner, R.; Schmidt, L. Ph H.; Schmidt-Böcking, H.; Stiebing, K. E.
2015-11-01
Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections.
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A FODO racetrack ring for nuSTORM: design and optimization
Energy Technology Data Exchange (ETDEWEB)
Liu, A.; Bross, A.; Neuffer, D.
2017-07-01
The goal of nuSTORM is to provide well-defined neutrino beams for precise measurements of neutrino cross-sections and oscillations. The nuSTORM decay ring is a compact racetrack storage ring with a circumference of ~ 480 m that incorporates large aperture (60 cm diameter) magnets. There are many challenges in the design. In order to incorporate the Orbit Combination section (OCS), used for injecting the pion beam into the ring, a dispersion suppressor is needed adjacent to the OCS . Concurrently, in order to maximize the number of useful muon decays, strong bending dipoles are needed in the arcs to minimize the arc length. These dipoles create strong chromatic effects, which need to be corrected by nonlinear sextupole elements in the ring. In this paper, a FODO racetrack ring design and its optimization using sextupolar fields via both a Genetic Algorithm (GA) and a Simulated Annealing (SA) algorithm will be discussed.
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International Nuclear Information System (INIS)
Zhang, Ch.; Matsui, S.; Hashimoto, S.
1999-01-01
The New SUBARU is a synchrotron light source being constructed at the SPring-8 site. The main facility is a 1.5 GeV electron storage ring that provides light beam in the region from VUV to soft X-ray using SPring-8's 1 GeV linac as an injector. The ring, with a circumference of about 119 meters, is composed of six bending cells. Each bending cell has two normal dipoles of 34 degree and one inverse dipole of -8 degree. The ring has six straight sections: two very long straight sections for a 11-m long undulator and an optical klystron, four short straight sections for a 2.3-m undulator, a super-conducting wiggler, rf cavity and injection, etc. The magnets of the storage ring are composed of 12 dipoles (BMs), 6 invert dipoles (BIs), 56 quadrupoles and 44 sextupoles, etc. For the magnet alignment, positions of the dipoles (the BMs and BIs) are determined by network survey method. The multipoles, which are mounted on girders between the dipoles, are aligned with a laser-CCD camera system. This article presents the methodology used to position the different components and particularly to assure the precise alignment of the multipoles. (authors)
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HISTRAP proposal: heavy-ion storage ring for atomic physics
Energy Technology Data Exchange (ETDEWEB)
Olsen, D K; Alton, G D; Datz, S; Dittner, P F; Dowling, D T; Haynes, D L; Hudson, E D; Johnson, J W; Lee, I Y; Lord, R S
1987-04-01
HISTRAP, Heavy-Ion Storage Ring for Atomic Physics, is a proposed 46.8-m-circumference synchrotron-cooling-storage ring optimized to accelerate, decelerate, and store beams of highly charge very-heavy ions at energies appropriate for advanced atomic physics research. The ring is designed to allow studies of electron-ion, photon-ion, ion-atom, and ion-ion interactions. An electron cooling system will provide ion beams with small angular divergence and energy spread for precision spectroscopic studies and also is necessary to allow the deceleration of heavy ions to low energies. HISTRAP will have a maximum bending power of 2.0 T m and will be injected with ions from either the existing Holifield Heavy Ion Research Facility 25-MV tandem accelerator or from a dedicated ECR source and 250 keV/nucleon RFQ linac.
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On the evolution of vortex rings with swirl
International Nuclear Information System (INIS)
Naitoh, Takashi; Okura, Nobuyuki; Gotoh, Toshiyuki; Kato, Yusuke
2014-01-01
A laminar vortex ring with swirl, which has the meridional velocity component inside the vortex core, was experimentally generated by the brief fluid ejection from a rotating outlet. The evolution of the vortex ring was investigated with flow visualizations and particle image velocimetry measurements in order to find the influence of swirling flow in particular upon the transition to turbulence. Immediately after the formation of a vortex ring with swirl, a columnar strong vortex along the symmetric axis is observed in all cases of the present experiment. Then the characteristic fluid discharging from a vortex ring with swirl referred to as “peeling off” appears. The amount of discharging fluid due to the “peeling off” increases with the angular velocity of the rotating outlet. We conjectured that the mechanism generating the “peeling off” is related to the columnar strong vortex by close observations of the spatio-temporal development of the vorticity distribution and the cutting 3D images constructed from the successive cross sections of a vortex ring. While a laminar vortex ring without swirl may develop azimuthal waves around its circumference at some later time and the ring structure subsequently breaks, the swirling flow in a vortex ring core reduces the amplification rate of the azimuthal wavy deformation and preserved its ring structure. Then the traveling distance of a vortex ring can be extended using the swirl flow under certain conditions
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On the evolution of vortex rings with swirl
Energy Technology Data Exchange (ETDEWEB)
Naitoh, Takashi, E-mail: naitoh.takashi@nitech.ac.jp [Department of Engineering Physics, Electronics and Mechanics, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Okura, Nobuyuki, E-mail: ohkura@meijo-u.ac.jp [Department of Vehicle and Mechanical Engineering, Meijo University, 1-501 Shiogamaguchi Tempaku-ku, Nagoya 468-8502 (Japan); Gotoh, Toshiyuki, E-mail: gotoh.toshiyuki@nitech.ac.jp [Department of Scientific and Engineering Simulation, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kato, Yusuke [Controller Business Unit Engineering Division 1, Engineering Department 3, Denso Wave Incorporated, 1 Yoshiike Kusagi Agui-cho, Chita-gun Aichi 470-2297 (Japan)
2014-06-15
A laminar vortex ring with swirl, which has the meridional velocity component inside the vortex core, was experimentally generated by the brief fluid ejection from a rotating outlet. The evolution of the vortex ring was investigated with flow visualizations and particle image velocimetry measurements in order to find the influence of swirling flow in particular upon the transition to turbulence. Immediately after the formation of a vortex ring with swirl, a columnar strong vortex along the symmetric axis is observed in all cases of the present experiment. Then the characteristic fluid discharging from a vortex ring with swirl referred to as “peeling off” appears. The amount of discharging fluid due to the “peeling off” increases with the angular velocity of the rotating outlet. We conjectured that the mechanism generating the “peeling off” is related to the columnar strong vortex by close observations of the spatio-temporal development of the vorticity distribution and the cutting 3D images constructed from the successive cross sections of a vortex ring. While a laminar vortex ring without swirl may develop azimuthal waves around its circumference at some later time and the ring structure subsequently breaks, the swirling flow in a vortex ring core reduces the amplification rate of the azimuthal wavy deformation and preserved its ring structure. Then the traveling distance of a vortex ring can be extended using the swirl flow under certain conditions.
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Penile length and circumference: an Indian study.
Promodu, K; Shanmughadas, K V; Bhat, S; Nair, K R
2007-01-01
Apprehension about the normal size of penis is a major concern for men. Aim of the present investigation is to estimate the penile length and circumference of Indian males and to compare the results with the data from other countries. Results will help in counseling the patients worried about the penile size and seeking penis enlargement surgery. Penile length in flaccid and stretched conditions and circumference were measured in a group of 301 physically normal men. Erected length and circumference were measured for 93 subjects. Mean flaccid length was found to be 8.21 cm, mean stretched length 10.88 cm and circumference 9.14 cm. Mean erected length was found to be 13.01 cm and erected circumference was 11.46 cm. Penile dimensions are found to be correlated with anthropometric parameters. Insight into the normative data of penile size of Indian males obtained. There are significant differences in the mean penile length and circumference of Indian sample compared to the data reported from other countries. Study need to be continued with a large sample to establish a normative data applicable to the general population.
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International Nuclear Information System (INIS)
Pivi, Mauro; Raubenheimer, Tor O.; Ghalam, Ali; Harkay, Katherine; Ohmi, Kazuhito; Wanzenberg, Rainer; Wolski, Andrzej; Zimmermann, Frank
2005-01-01
Collective instabilities caused by the formation of an electron cloud (EC) are a potential limitation to the performances of the damping rings for a future linear collider. In this paper, we present recent simulation results for the electron cloud build-up in damping rings of different circumferences and discuss the single-bunch instabilities driven by the electron cloud
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Status of the Frankfurt low energy electrostatic storage ring (FLSR)
International Nuclear Information System (INIS)
King, F; Kruppi, T; Müller, J; Dörner, R; Schmidt, L Ph H; Schmidt-Böcking, H; Stiebing, K E
2015-01-01
Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections. (paper)
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Zapata-Castilleja, Carlos A; Montes-Tapia, Fernando F; Treviño-Garza, Consuelo; Martínez-Cobos, María C; García-Cantú, Jesús; Arenas-Fabbri, Vincenzo; de la O-Escamilla, Norma; de la O-Cavazos, Manuel
2017-04-01
Lactose intolerance is a common disease in pediatrics, and its wrong diagnosis will lead to morbidity. The primary objective of this study was to assess the usefulness of an increased waist circumference during the hydrogen breath test as a predictor of lactose intolerance. The secondary objective was to analyze the impact of body mass index, waist circumference measurement, and age on the abdominal distension of patients with lactose intolerance. A total of 138 subjects aged 3 to 15 years were included. They underwent serial measurements of the waist circumference and hydrogen levels in the breath every 30 minutes over 3 hours during the hydrogen breath test. Out of the entire sample, 35 (25.4%) patients had lactose intolerance. An increase of 0.85 cm in waist circumference compared to the baseline waist circumference results in a sensitivity of 88% and a specificity of 85% to predict lactose intolerance (odds ratio: 42.14, 95% confidence interval: 13.08-135.75, p ≤ 0.001). The body mass index and waist circumference measurement did not affect abdominal distension (p= not significant); however, age modified the time of distension. A 0.85 cm increase in waist circumference compared to the baseline waist circumference during the hydrogen breath test is a useful parameter for the diagnosis of lactose intolerance in pediatrics. Variations in relation to body mass index and waist circumference did not affect the usefulness of an increased waist circumference, unlike age.
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Radiation safety design for SSRL storage ring
Energy Technology Data Exchange (ETDEWEB)
Khater, Hesham [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)]. E-mail: khater1@llnl.gov; Liu, James [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Fasso, Alberto [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Prinz, Alyssa [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Rokni, Sayed [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)
2006-12-15
In 2003, the Stanford Synchrotron Radiation Laboratory (SSRL) had upgraded its storage ring to a 3rd generation storage ring (SPEAR3). SPEAR3 is deigned to operate at 500-mA stored beam current and 3-GeV energy. The 234-m circumference SPEAR3 ring utilizes 60-cm-thick concrete lateral walls, 30-cm-thick concrete roof, as well as 60- or 90-cm-thick concrete ratchet walls. A total of 3.5x10{sup 15}e{sup -}/y will be injected into the ring with an injection power of 4W and an injection efficiency of 75%. Normal beam losses occur due to both injection and stored beam operations in the total of 20 low loss as well as 3 high loss limiting apertures. During the 6-min injection period, an instantaneous power loss of 0.05W occurs at each low loss aperture. When averaged over the operational year, the loss of both the injection and the stored beams is equivalent to an average loss of 2mW at each low loss aperture. On the other hand, the average losses in the high loss apertures are 16mW for the injection septum, 47mW for the beam abort dump, and 13mW for the ring stoppers. The shielding requirements for losses in the new ring were based on a generic approach that used both FLUKA Monte Carlo particle generation and transport code and empirical computer codes and formulae.
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Broadband impedance of the NESTOR storage ring
International Nuclear Information System (INIS)
Androsov, V.P.; Gladkikh, P.I.; Gvozd, A.M.; Karnaukhov, I.M.; Telegin, Yu.N.
2011-01-01
The contributions from lossy and inductive vacuum chamber components to the broadband impedance of the NESTOR storage ring are obtained by using both low-frequency analytical approaches and computer simulations. As was expected considering the small ring circumference (15.44m), the main contributions both to the longitudinal impedance Z || /n and the loss factor k loss come from the RF-cavity. Cavity impedance was also estimated with CST Microwave Studio (CST Studio Suite TM 2006) by simulating coaxial wire method commonly used for impedance measurements. Both estimates agree well. Finally, we performed the simulations of a number of inductive elements with CST Particle Studio 2010 by using wake field solver. We have also evaluated the bunch length in NESTOR taking the conservative estimate of 3 Ohm for the ring broadband impedance and have found that the bunch length s z = 0.5 cm could be obtained in steady state operation mode for the designed bunch current of 10 mA and RF-voltage of 250 kV.
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Electronic properties of superlattices on quantum rings.
da Costa, D R; Chaves, A; Ferreira, W P; Farias, G A; Ferreira, R
2017-04-26
We present a theoretical study of the one-electron states of a semiconductor-made quantum ring (QR) containing a series of piecewise-constant wells and barriers distributed along the ring circumference. The single quantum well and the superlattice cases are considered in detail. We also investigate how such confining potentials affect the Aharonov-Bohm like oscillations of the energy spectrum and current in the presence of a magnetic field. The model is simple enough so as to allow obtaining various analytical or quasi-analytical results. We show that the well-in-a-ring structure presents enhanced localization features, as well as specific geometrical resonances in its above-barrier spectrum. We stress that the superlattice-in-a-ring structure allows giving a physical meaning to the often used but usually artificial Born-von-Karman periodic conditions, and discuss in detail the formation of energy minibands and minigaps for the circumferential motion, as well as several properties of the superlattice eigenstates in the presence of the magnetic field. We obtain that the Aharonov-Bohm oscillations of below-barrier miniband states are reinforced, owing to the important tunnel coupling between neighbour wells of the superlattice, which permits the electron to move in the ring. Additionally, we analysis a superlattice-like structure made of a regular distribution of ionized impurities placed around the QR, a system that may implement the superlattice in a ring idea. Finally, we consider several random disorder models, in order to study roughness disorder and to tackle the robustness of some results against deviations from the ideally nanostructured ring system.
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Pulsed rf systems for large storage rings
International Nuclear Information System (INIS)
Wilson, P.B.
1979-03-01
The possibility is considered that by using a pulsed rf system a substantial reduction can be made in the rf power requirement for the next generation of large storage rings. For a ring with a sufficiently large circumference, the time between bunch passages, T/sub b/, can exceed the cavity filling time, T/sub f/. As the ratio T/sub b//T/sub f/ increases, it is clear that at some point the average power requirement can be reduced by pulsing the rf to the cavities. In this mode of operation, the rf power is turned on a filling time or so before the arrival of a bunch and is switched off again at the time of bunch passage. There is no rf energy in the accelerating structure, and hence no power dissipation, for most of the period between bunches
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The g-2 storage ring superconducting magnet system
International Nuclear Information System (INIS)
Green, M.A.
1993-09-01
The g-2 μ lepton (muon) storage ring is a single dipole magnet that is 44 meters in circumference. The storage ring dipole field is created by three large superconducting solenoid coils. A single outer solenoid, 15.1 meters in diameter, carries 254 kA. Two inner solenoids, 13.4 meters in diameter, carry 127 kA each in opposition to the current carried by the outer solenoid. A room temperature C shaped iron yoke returns the magnetic flux and shapes the magnetic field in a 180 mm gap where the stored muon beam circulates. The gap induction will be 1.47 T. This report describes the three large superconducting solenoids, the cryogenic system needed to keep them cold, the solenoid power supply and the magnet quench protection system
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Directory of Open Access Journals (Sweden)
Annick Doucet
2012-08-01
Full Text Available In this study, we analysed the tree-ring metal concentrations and isotope ratios of five stands located in three contrasted settings to infer the diffuse air pollution history of the northern part of the Windsor–Québec City Corridor in eastern Canada. Tree-ring series show that the Cd and Zn accumulation rates were higher between 1960 and 1986 and that the long-term acidification of the soil (Ca/Al series was likely induced by NOx and SOx deposition (δ15N and δ13C trends as proxy. The Pb concentrations and 206Pb/207Pb ratios indicate that the dominant source of lead from 1880 to the 1920s was the combustion of north-eastern American coal, which was succeeded by the combustion of leaded gasoline from the 1920s to the end of the 1980s. Our modelling approach allows separating the climatic and anthropogenic effects on the tree-ring δ13C and δ18O responses. Diffuse air pollution caused an enrichment in 13C in all stands and a decrease of the δ18O values only in three of the stands. This study indicates that dendrogeochemistry can show contrasted responses to environmental changes and that the combination of several independent indicators constitutes a powerful tool to reconstruct the air pollution history in the complex context of peri-urban regions.
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Neck Circumference May Be a Better Alternative to Standard Anthropometric Measures
Directory of Open Access Journals (Sweden)
Kaumudi Joshipura
2016-01-01
Full Text Available This paper evaluates neck circumference as a metabolic risk marker. Overweight/obese, nondiabetic Hispanics, 40–65 years old, who are free of major cardiovascular diseases, were recruited for the San Juan Overweight Adults Longitudinal Study (SOALS. Baseline exams were completed by 1,206 participants. Partial correlation coefficients (r and logistic models adjusted for age, gender, smoking status, and physical activity were computed. Neck circumference was significantly correlated with waist circumference (r=0.64, BMI (r=0.66, and body fat % (r=0.45. Neck circumference, highest (compared to lowest tertile, had higher association with prediabetes: multivariable OR = 2.30 (95% CI: 1.71–3.06 compared to waist circumference OR = 1.97 (95% CI: 1.48–2.66 and other anthropometric measures. Neck circumference showed higher associations with HOMA, low HDL-C, and triglycerides, multivariable OR = 8.42 (95% CI: 5.43–13.06, 2.41 (95% CI: 1.80–3.21, and 1.52 (95% CI: 1.14–2.03, but weaker associations with hs-CRP and hypertension, OR = 3.61 (95% CI: 2.66–4.90 and OR = 2.58 (95% CI: 1.90–3.49, compared to waist circumference. AIC for model fit was generally similar for neck or waist circumference. Neck circumference showed similar or better associations with metabolic factors and is more practicable than waist circumference. Hence, neck circumference may be a better alternative to waist circumference.
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Design of a lattice for JAERI storage ring (JSR)
International Nuclear Information System (INIS)
Harada, Shunji; Yokomizo, Hideaki; Yanagida, Kenichi
1990-08-01
The new 8GeV synchrotron radiation facility (SPring-8) is planned to be constructed in Japan, and our institute (JAERI) are involved in this project with RIKEN. A compact electron storage ring JSR has been constructed in JAERI in order to study various kind of accelerator technologies, to test some devices such as the insertion devices and the beam monitors, and to train young researchers. The ring size is limited by the available space of a linac building, so that the circumference of JSR becomes 20.546 m. However, even in this small ring, one straight section with the length of ∼1.5 m, where the dispersion is free, is provided for the insertion device study. JSR takes Chasman-Green lattice with a superperiodicity of three. JSR is possible not only to suppress the dispersion but also to leave it on the long straight section. An electron beam from a linac is accepted into JSR in any operating modes. (author)
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First results for a FCC-hh ring optics design
Chance, Antoine; Payet, Jacques; Alemany Fernandez, Reyes; Holzer, Bernhard; Schulte, Daniel
2015-01-01
The first order considerations of the optics for the FCC-hh ring are presented. The arc cell is generated taking into account some general considerations like the whole circumference, maximum gradients and lengths of the elements in the cell. The integration of the insertion regions started. Three types of Dispersion Suppressors (DIS) are studied. The sensitivity of the arc parameters to these layout considerations is studied in more detail. An alternative layout is shown as well.
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Deciphering Intrinsic Inter-subunit Couplings that Lead to Sequential Hydrolysis of F 1 -ATPase Ring
Dai, Liqiang; Flechsig, Holger; Yu, Jin
2017-10-01
The rotary sequential hydrolysis of metabolic machine F1-ATPase is a prominent feature to reveal high coordination among multiple chemical sites on the stator F1 ring, which also contributes to tight coupling between the chemical reaction and central {\\gamma}-shaft rotation. High-speed AFM experiments discovered that the sequential hydrolysis was maintained on the F1 ring even in the absence of the {\\gamma} rotor. To explore how the intrinsic sequential performance arises, we computationally investigated essential inter-subunit couplings on the hexameric ring of mitochondrial and bacterial F1. We first reproduced the sequential hydrolysis schemes as experimentally detected, by simulating tri-site ATP hydrolysis cycles on the F1 ring upon kinetically imposing inter-subunit couplings to substantially promote the hydrolysis products release. We found that it is key for certain ATP binding and hydrolysis events to facilitate the neighbor-site ADP and Pi release to support the sequential hydrolysis. The kinetically feasible couplings were then scrutinized through atomistic molecular dynamics simulations as well as coarse-grained simulations, in which we enforced targeted conformational changes for the ATP binding or hydrolysis. Notably, we detected the asymmetrical neighbor-site opening that would facilitate the ADP release upon the enforced ATP binding, and computationally captured the complete Pi release through charge hopping upon the enforced neighbor-site ATP hydrolysis. The ATP-hydrolysis triggered Pi release revealed in current TMD simulation confirms a recent prediction made from statistical analyses of single molecule experimental data in regard to the role ATP hydrolysis plays. Our studies, therefore, elucidate both the concerted chemical kinetics and underlying structural dynamics of the inter-subunit couplings that lead to the rotary sequential hydrolysis of the F1 ring.
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Fredriks, A.M.; Buuren, S. van; Fekkes, M.; Verloove-Vanhorick, S.P.; Wit, J.M.
2005-01-01
The aim of this study was to present age references for waist circumference (WC), hip circumference (HC), and waist/hip ratio (WHR) in Dutch children. Cross-sectional data were obtained from 14,500 children of Dutch origin in the age range 0-21 years. National references were constructed with the
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Taylor, Richard D; MacCoss, Malcolm; Lawson, Alastair D G
2014-07-24
We have analyzed the rings, ring systems, and frameworks in drugs listed in the FDA Orange Book to understand the frequency, timelines, molecular property space, and the application of these rings in different therapeutic areas and target classes. This analysis shows that there are only 351 ring systems and 1197 frameworks in drugs that came onto the market before 2013. Furthermore, on average six new ring systems enter drug space each year and approximately 28% of new drugs contain a new ring system. Moreover, it is very unusual for a drug to contain more than one new ring system and the majority of the most frequently used ring systems (83%) were first used in drugs developed prior to 1983. These observations give insight into the chemical novelty of drugs and potentially efficient ways to assess compound libraries and develop compounds from hit identification to lead optimization and beyond.
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HEAD CIRCUMFERENCE REFERENCES FOR SCHOOL AGE CHILDREN IN WESTERN ROMANIA.
Chirita-Emandi, Adela; Doros, Gabriela; Simina, Iulia Jurca; Gafencu, Mihai; Puiu, Maria
2015-01-01
To provide head circumference references for school-aged children in western Romania, and compare them with references from other European countries. A total of 2742 children, aged 6-19 years, from Timis county, were examined by medical students, between February 2010-June 2011. Head circumference references were constructed by Cole's LMS method with LMSChartMaker software. The Romanian 3rd, 50th and 97th percentiles for head circumference were compared with recent references from Belgium and Germany. Generally, boys show significantly larger head circumference compared to girls at any age. The head circumference increments between 6 and 19 years are Romania to those from Germany and Belgium, we found lower median head circumference in Romanian boys and girls, that could be explained by a taller stature of boys and girls in Germany and Belgium compared to Romania.
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Status of the maintenance for the KEK 12GEV-PS main ring and power supply
International Nuclear Information System (INIS)
Sato, Hikaru; Igarashi, Susumu; Marutsuka, Katsumi; Mikawa, Katsuhiko; Shirakata, Masashi; Sueno, Tsuyoshi; Tokuda, Noboru
2004-01-01
More than 30 years passed since the KEK 12GeV-PS construction, some of accelerator equipments are highly radiated, especially the injection and the extraction equipments. In recent years, the higher intensity beam has been required for such as the long baseline neutrino oscillation experiment and rare decay experiments. Then, the circumference of the maintenance work has become severe. Further, almost equipments of main ring and power supply have deteriorated. Status of the Maintenance for the KEK 12GeV-PS main ring and power supply are presented. (author)
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Formation of moon induced gaps in dense planetary rings
Grätz, F.; Seiß, M.; Spahn, F.
2017-09-01
Recent works have shown that bodies embedded in planetary rings create S-shaped density modula- tions called propellers if their mass deceeds a certain threshold or cause a gap around the entire circumference of the disc if the embedded bodies mass exceeds it. Two counteracting physical processes govern the dynamics and determine what structure is created: The gravitational disturber excerts a torque on nearby disc particles, sweeping them away from itself on both sides thus depleting the discs density and forming a gap. Diffusive spreading of the disc material due to collisions counteracts the gravitational scattering and has the tendency to fill the gap. We develop a nonlinear diffusion model that accounts for those two counteracting processes and describes the azimutally averaged surface density profile an embedded moon creates in planetary rings. The gaps width depends on the moons mass, its radial position and the rings viscosity allowing us to estimate the rings viscosity in the vicinity of the Encke and Keeler gap in Saturns A-Ring and compare it to previous measurements. We show that for the Keeler gap the time derivative of the semi-major axis as derived by Goldreich and Tremaine 1980 is underestimated yielding an underestimated viscosity for the ring. We therefore derive a corrected expression for said time derivative by fitting the solutions of Hill's equations for an ensemble of test particles. Furthermore we estimate the masses for potentionally unseen moonlets in the C-Ring and Cassini division.
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Mid-upper-arm-circumference and mid-upper-arm circumference z-score
DEFF Research Database (Denmark)
Rasmussen, J; Andersen, A; Fisker, A B
2012-01-01
Mid-upper-arm circumference (MUAC) is a simple method of assessing nutritional status in children above 6 months of age. In 2007 World Health Organization (WHO) introduced a MUAC z-score for children above 3 months of age. We evaluated whether MUAC or MUAC z-score had the best ability to identify...
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Topological matter, integrable models and fusion rings
International Nuclear Information System (INIS)
Nemeschansky, D.; Warner, N.P.
1992-01-01
We show how topological G k /G k models can be embedded into the topological matter models that are obtained by perturbing the twisted N = 2 supersymmetric, hermitian symmetric, coset models. In particular, this leads to an embedding of the fusion ring of G as a sub-ring of the perturbed, chiral primary ring. The perturbation of the twisted N = 2 model that leads to the fusion ring is also shown to lead to an integrable N = 2 supersymmetric field theory when the untwisted N = 2 superconformal field theory is perturbed by the same operator and its hermitian conjugate. (orig.)
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Beam vacuum system of Brookhaven's muon storage ring
International Nuclear Information System (INIS)
Hseuth, H.C.; Snydstrup, L.; Mapes, M.
1995-01-01
A storage ring with a circumference of 45 m is being built at Brookhaven to measure the g-2 value of the muons to an accuracy of 0.35 ppm.. The beam vacuum system of the storage ring will operate at 10 -7 Torr and has to be completely non-magnetic. It consists of twelve sector chambers. The chambers are constructed of aluminum and are approximately 3.5 m in length with a rectangular cross-section of 16.5 cm high by 45 cm at the widest point. The design features, fabrication techniques and cleaning methods for these chambers are described. The beam vacuum system will be pumped by forty eight non-magnetic distributed ion pumps with a total pumping speed of over 2000 ell/sec. Monte Carlo simulations of the pressure distribution in the muon storage region are presented
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Development of stress relaxation measurement by a small size C-ring specimen method
International Nuclear Information System (INIS)
Shimanuki, Shizuka; Nakata, Kiyotomo; Kasahara, Shigeki; Kuniya, Jiro
2002-01-01
A stress relaxation measurement method has been developed by using C-ring specimens, and a specimen size effect has been evaluated taking radiation-induced stress relaxation into consideration. C-ring specimens were stressed by forcing a wedge in the gap. Giving an appropriate eccentric configuration in the half of the ring opposite the gap, the stress gradient along the circumference was eliminated in the section and the stress level could be varied by changing the gap spacing. The validity of the C-ring test method was confirmed by thermally stress relaxation experiments at annealing temperatures from 300 to 600degC for 1 min to 200 h in carbon steel: considerable stress relaxation could be measured for all levels of applied stress even at relatively low annealing temperatures. The relaxation results obtained from the C-ring test were in good agreement with those from a uniaxial tensile stress relaxation test. The smaller C-ring specimen with about 40 mm diameter, which is required for radiation-induced stress relaxation test, also showed adequate accuracy on stress relaxation at 600 to 830degC in stainless steel, compared with the large size C-ring specimen test. (author)
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International Nuclear Information System (INIS)
RATHBONE, B.A.
1999-01-01
This study evaluates the effectiveness of lead lined gloves in reducing extremity dose from two sources specific to tank waste sampling activities: (1) sludge inside glass sample jars and (2) sludge as thin layer contamination on the exterior surface of sample jars. The response of past and present Hanford Extremity Dosimeters (ring) designs under these conditions is also evaluated
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Energy Technology Data Exchange (ETDEWEB)
RATHBONE, B.A.
1999-06-24
This study evaluates the effectiveness of lead lined gloves in reducing extremity dose from two sources specific to tank waste sampling activities: (1) sludge inside glass sample jars and (2) sludge as thin layer contamination on the exterior surface of sample jars. The response of past and present Hanford Extremity Dosimeters (ring) designs under these conditions is also evaluated.
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Study of lead free ferroelectrics using overlay technique on thick film microstrip ring resonator
Directory of Open Access Journals (Sweden)
Shridhar N. Mathad
2016-03-01
Full Text Available The lead free ferroelectrics, strontium barium niobates, were synthesized via the low cost solid state reaction method and their fritless thick films were fabricated by screen printing technique on alumina substrate. The X band response (complex permittivity at very high frequencies of Ag thick film microstrip ring resonator perturbed with strontium barium niobates (SrxBa1-xNb2O6 in form of bulk and thick film was measured. A new approach for determination of complex permittivity (ε′ and ε′′ in the frequency range 8–12 GHz, using perturbation of Ag thick film microstrip ring resonator (MSRR, was applied for both bulk and thick film of strontium barium niobates (SrxBa1-xNb2O6. The microwave conductivity of the bulk and thick film lie in the range from 1.779 S/cm to 2.874 S/cm and 1.364 S/cm to 2.296 S/cm, respectively. The penetration depth of microwave in strontium barium niobates is also reported.
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Sonographic large fetal head circumference and risk of cesarean delivery.
Lipschuetz, Michal; Cohen, Sarah M; Israel, Ariel; Baron, Joel; Porat, Shay; Valsky, Dan V; Yagel, Oren; Amsalem, Hagai; Kabiri, Doron; Gilboa, Yinon; Sivan, Eyal; Unger, Ron; Schiff, Eyal; Hershkovitz, Reli; Yagel, Simcha
2018-03-01
Persistently high rates of cesarean deliveries are cause for concern for physicians, patients, and health systems. Prelabor assessment might be refined by identifying factors that help predict an individual patient's risk of cesarean delivery. Such factors may contribute to patient safety and satisfaction as well as health system planning and resource allocation. In an earlier study, neonatal head circumference was shown to be more strongly associated with delivery mode and other outcome measures than neonatal birthweight. In the present study we aimed to evaluate the association of sonographically measured fetal head circumference measured within 1 week of delivery with delivery mode. This was a multicenter electronic medical record-based study of birth outcomes of primiparous women with term (37-42 weeks) singleton fetuses presenting for ultrasound with fetal biometry within 1 week of delivery. Fetal head circumference and estimated fetal weight were correlated with maternal background, obstetric, and neonatal outcome parameters. Elective cesarean deliveries were excluded. Multinomial regression analysis provided adjusted odds ratios for instrumental delivery and unplanned cesarean delivery when the fetal head circumference was ≥35 cm or estimated fetal weight ≥3900 g, while controlling for possible confounders. In all, 11,500 cases were collected; 906 elective cesarean deliveries were excluded. A fetal head circumference ≥35 cm increased the risk for unplanned cesarean delivery: 174 fetuses with fetal head circumference ≥35 cm (32%) were delivered by cesarean, vs 1712 (17%) when fetal head circumference cesarean delivery by an adjusted odds ratio of 1.75 (95% confidence interval, 1.4-2.18) controlling for gestational age, fetal gender, and epidural anesthesia. The rate of prolonged second stage of labor was significantly increased when either the fetal head circumference was ≥35 cm or the estimated fetal weight ≥3900 g, from 22.7% in the total
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CESAR, 2 MeV electron storage ring.
CERN PhotoLab
1967-01-01
CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.
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Orgasm and women's waist circumference.
Costa, Rui Miguel; Brody, Stuart
2014-11-01
Given that adiposity is related to poorer female sexual function, among many other health problems, the present study aimed at testing the hypothesis that larger waist circumference, an index of subcutaneous and abdominal fat mass, is associated with lack of specifically vaginal orgasm. Study design One hundred and twenty Portuguese women of reproductive age had their waist measured and reported their past month frequency of penile-vaginal intercourse (PVI), vaginal orgasm, orgasm from clitoral masturbation during PVI, non-coital partnered sex (in the absence of same-day PVI), non-coital partnered sex orgasm (regardless of same-day PVI), masturbation, and masturbation orgasm. In both simple and partial correlations (controlling for age, social desirability responding, relationship status, and cohabitation status), larger waist circumference was associated with lack of any vaginal orgasm and with having masturbated in the past month. In a multiple regression, larger waist circumference was independently predicted by lesser frequency of vaginal orgasm, greater frequency of masturbation, and older age. Abdominal fat mass appears to be adversely associated with lesser capacity for vaginal orgasm, but not for orgasms from other sexual activities. Results are discussed in the context of vaginal orgasm being relatively more contingent on situations of increased fitness in both partners. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
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Is neck circumference measurement an indicator for abdominal ...
African Journals Online (AJOL)
Background: Neck circumference (NC) measurement is one of the simple screening measurements which can be used as an index of upper body fat distribution to identify obesity. Objectives: The aim of this study was to determine the relationship between neck circumferences and obesity. Methods:A total 411 volunteer ...
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Hyperinsulinemia and waist circumference in childhood metabolic syndrome
International Nuclear Information System (INIS)
Lone, S.W.; Ibrahim, M.N.; Leghari, T.M.; Khan, Y.N.; Raza, J.
2011-01-01
To determine the characteristics of obese children presenting at a tertiary care hospital and the frequency of metabolic syndrome (MS) in them using two paediatric definitions. A total of 262 obese children aged 4-16 years, with BMI greater than 95 percentile were included. Children having obesity due to syndromes, medications causing weight gain, chronic illness and developmental disability were excluded. Blood pressure, waist circumference, fasting triglycerides, HDL, insulin and glucose levels were obtained. Obesity was defined as BMI > 95 percentile for age and gender according to the UK growth reference charts. The prevalence of metabolic syndrome was estimated using to the De Ferrantis and Lambert definitions. The frequency of MS varied between 16% and 52% depending on whether insulin levels were included in the definition. There was a significant positive correlation(r) when the metabolic parameters were correlated with waist circumference and insulin levels, except HDL which was negatively correlated. All the metabolic parameters like waist circumference, triglycerides, high density lipoprotein cholesterol and systolic blood pressure increased considerably across the insulin quartile (p < 0.05). The most noteworthy anthropometric and metabolic abnormality were the waist circumference (46.5%) and insulin levels (58%) respectively. There was a marked difference in the frequency of metabolic syndrome according to the definition used. The waist circumference and hyperinsulinemia are significant correlates of MS in obese children. There is a need for establishing normal insulin ranges according to age, gender and pubertal status. The clinical examination and investigations ought to include waist circumference and insulin levels together as a part of the definition of MS, for early detection and intervention of childhood obesity. (author)
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The Storage Ring Magnets of the Australian Synchrotron
International Nuclear Information System (INIS)
Barg, B.; Jackson, A.; LeBlanc, G.; Melbourne U.; Huttel, E.; Karlsruhe, Forschungszentrum; Tanabe, J.; SLAC
2005-01-01
A 3 GeV Synchrotron Radiation Source is being built in Melbourne, Australia. Commissioning is foreseen in 2006. The Storage ring has a circumference of 216 m and has a 14 fold DBA structure. For the storage ring the following magnets will be installed: 28 dipoles with a field of 1.3 T, and a gradient of 3.35 T/m; 56 quadrupoles with a gradient of 18 T/m and 28 with a gradient of 10 T/m; 56 sextupoles with a strength of B'' = 350 T/m and 42 with 150 T/m. The sextupoles are equipped with additional coils for horizontal and vertical steering and for a skew quadrupole. The pole profile was determined by scaling the pole profile of the SPEAR magnets [1] to the aperture of the ASP magnets. The magnets are to be supplied by Buckley Systems Ltd in Auckland, New Zealand
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Ring correlations in random networks.
Sadjadi, Mahdi; Thorpe, M F
2016-12-01
We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.
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Quantum Fourier Transform Over Galois Rings
Zhang, Yong
2009-01-01
Galois rings are regarded as "building blocks" of a finite commutative ring with identity. There have been many papers on classical error correction codes over Galois rings published. As an important warm-up before exploring quantum algorithms and quantum error correction codes over Galois rings, we study the quantum Fourier transform (QFT) over Galois rings and prove it can be efficiently preformed on a quantum computer. The properties of the QFT over Galois rings lead to the quantum algorit...
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Energy Technology Data Exchange (ETDEWEB)
Rubin, David L. [Cornell Univ., Ithaca, NY (United States). Dept. of Physics
2015-01-23
Accelerators that collide high energy beams of matter and anti-matter are essential tools for the investigation of the fundamental constituents of matter, and the search for new forms of matter and energy. A “Linear Collider” is a machine that would bring high energy and very compact bunches of electrons and positrons (anti-electrons) into head-on collision. Such a machine would produce (among many other things) the newly discovered Higgs particle, enabling a detailed study of its properties. Among the most critical and challenging components of a linear collider are the damping rings that produce the very compact and intense beams of electrons and positrons that are to be accelerated into collision. Hot dilute particle beams are injected into the damping rings, where they are compressed and cooled. The size of the positron beam must be reduced more than a thousand fold in the damping ring, and this compression must be accomplished in a fraction of a second. The cold compact beams are then extracted from the damping ring and accelerated into collision at high energy. The proposed International Linear Collider (ILC), would require damping rings that routinely produce such cold, compact and intense beams. The goal of the Cornell study was a credible design for the damping rings for the ILC. Among the technical challenges of the damping rings; the development of instrumentation that can measure the properties of the very small beams in a very narrow window of time, and mitigation of the forces that can destabilize the beams and prevent adequate cooling, or worse lead to beam loss. One of the most pernicious destabilizing forces is due to the formation of clouds of electrons in the beam pipe. The electron cloud effect is a phenomenon in particle accelerators in which a high density of low energy electrons, build up inside the vacuum chamber. At the outset of the study, it was anticipated that electron cloud effects would limit the intensity of the positron ring
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Thigh circumference and risk of heart disease and premature death
DEFF Research Database (Denmark)
Heitmann, Berit L; Frederiksen, Peder
2009-01-01
of follow-up for total death. RESULTS: A small thigh circumference was associated with an increased risk of cardiovascular and coronary heart diseases and total mortality in both men and women. A threshold effect for thigh circumference was evident, with greatly increased risk of premature death below...... circumference seems to be associated with an increased risk of developing heart disease or premature death. The adverse effects of small thighs might be related to too little muscle mass in the region. The measure of thigh circumference might be a relevant anthropometric measure to help general practitioners...... in early identification of individuals at an increased risk of premature morbidity and mortality....
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Common variants at 12q15 and 12q24 are associated with infant head circumference
H.R. Taal (Rob); B. St Pourcain (Beate); E. Thiering (Eelisabeth); S. Das (Shikta); D.O. Mook-Kanamori (Dennis); N.M. Warrington (Nicole); M. Kaakinen (Marika); E. Kreiner-Møller (Eskil); J.P. Bradfield (Jonathan); R.M. Freathy (Rachel); F. Geller (Frank); M. Guxens Junyent (Mònica); D.L. Cousminer (Diana); M. Kerkhof (Marjan); N.J. Timpson (Nicholas); M.A. Ikram (Arfan); L.J. Beilin (Lawrence); K. Bønnelykke (Klaus); J.L. Buxton (Jessica); P. Charoen (Pimphen); B.L.K. Chawes (Bo Lund Krogsgaard); J.G. Eriksson (Johan); D.M. Evans (David); A. Hofman (Albert); J.P. Kemp (John); C.E. Kim (Cecilia); N. Klopp (Norman); J. Lahti (Jari); S.J. Lye (Stephen); G. Mcmahon (George); F.D. Mentch (Frank); M. Müller-Nurasyid (Martina); P.F. O'Reilly (Paul); I. Prokopenko (Inga); F. Rivadeneira Ramirez (Fernando); E.A.P. Steegers (Eric); J. Sunyer (Jordi); C. Tiesler (Carla); H. Yaghootkar (Hanieh); M.M.B. Breteler (Monique); S. Debette (Stéphanie); M. Fornage (Myriam); V. Gudnason (Vilmunder); L.J. Launer (Lenore); A. van der Lugt (Aad); T.H. Mosley (Thomas); S. Seshadri (Sudha); A.V. Smith (Albert V.); M.W. Vernooij (Meike); A.I.F. Blakemore (Alexandra); R.M. Chiavacci (Rosetta); B. Feenstra (Bjarke); J. Fernandez-Banet (Julio); S.F.A. Grant (Struan); A.-L. Hartikainen (Anna-Liisa); A.J. van der Heijden (Albert); C. Iniguez (Carmen); M. Lathrop (Mark); W.L. McArdle (Wendy); A. Mølgaard (Anne); J.P. Newnham (John); L.J. Palmer (Lyle); A. Palotie (Aarno); A. Pouta (Anneli); S.M. Ring (Susan); U. Sovio (Ulla); M. Standl (Marie); A.G. Uitterlinden (André); E.H. Wichmann (Erich); N.H. Vissing (Nadja); C. DeCarli (Charles); C.M. van Duijn (Cornelia); M.I. McCarthy (M.); G.H. Koppelman (Gerard); X. Estivill (Xavier); A.T. Hattersley (Andrew); M. Melbye (Mads); H. Bisgaard (Hans); C.E. Pennell (Craig); E. Widen (Elisabeth); H. Hakonarson (Hakon); G. Davey-Smith (George); J. Heinrich (Joachim); M.-R. Jarvelin (Marjo-Riitta); V.W.V. Jaddoe (Vincent)
2012-01-01
textabstractTo identify genetic variants associated with head circumference in infancy, we performed a meta-analysis of seven genome-wide association studies (GWAS) (N = 10,768 individuals of European ancestry enrolled in pregnancy and/or birth cohorts) and followed up three lead signals in six
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Dietary predictors of 5-year changes in waist circumference
DEFF Research Database (Denmark)
Halkjaer, Jytte; Tjønneland, Anne; Overvad, Kim
2009-01-01
the association between intake from 21 food and beverage groups and the subsequent 5-year difference in waist circumference. METHODS: The study population consisted of 22,570 women and 20,126 men, aged 50 to 64 years at baseline, with complete data on baseline and follow-up waist circumference, baseline diet (192...... items food frequency questionnaire), body mass index, and selected potential confounders (eg, smoking status, sport activities, and intake of alcoholic beverages). Multiple linear regression analyses were performed. RESULTS: For women, 5-year difference in waist circumference was inversely related...... intake was positively associated. Sex differences occurred for vegetables, high-fat dairy products, and processed meat. CONCLUSIONS: The results suggest that a diet low in fruits and red meat and high in snack foods was associated with larger waist circumference gains in both sexes. Furthermore, in women...
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The value of hip circumference/heightx ratio for identifying childhood hypertension
Lu, Na; Wang, Rui; Ji, Meijing; Liu, Xiaoli; Qiang, Lu; Ma, Chunming; Yin, Fuzai
2018-01-01
To investigate the value of hip circumference related indexes for identifying childhood hypertension. In 2011, 1,352 Han children aged 7–12 years were recruited in our study. Hypertension was defined as systolic blood pressure or diastolic blood pressure ≥95th percentile for all three screenings. We set the power value of the hip circumference/heightx ratio (x = 0, 0.8, 1 and 1.5) and studied the association with blood pressure. Hip circumference, hip circumference/height0.8, hip circumferenc...
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Rejection of atrial sensing artifacts by a pacing lead with short tip-to-ring spacing.
Nash, A; Fröhlig, G; Taborsky, M; Stammwitz, E; Maru, F; Bouwens, L H M; Celiker, C
2005-01-01
The ability of a new pacing lead design, with a 10 mm tip-to-ring spacing, to facilitate rejection of sensed far field R-waves and myopotentials was evaluated. Measurements were performed in 66 patients. The occurrence of far field R-wave sensing and myopotential sensing was determined by means of the surface ECG and the ECG markers provided by the pacemaker. At an atrial sensitivity of 0.25 mV and an atrial blanking of 50 ms far field R-wave sensing was observed in 12 patients (18.2%) and at an atrial sensitivity of 1.0 mV no far-field R-wave sensing was observed. Myopotentials were sensed in 3 patients. In all patients the measured P-wave amplitude was at least twice the estimated amplitude of the far field R-wave at an atrial blanking of 50 ms. The results from this study show that a small tip-to-ring spacing allows for programming of a high atrial sensitivity and short atrial blanking with an acceptably low risk for atrial artifact sensing.
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Evaluation of Internet-Based Interventions on Waist Circumference Reduction: A Meta-Analysis.
Seo, Dong-Chul; Niu, Jingjing
2015-07-21
Internet-based interventions are more cost-effective than conventional interventions and can provide immediate, easy-to-access, and individually tailored support for behavior change. Waist circumference is a strong predictor of an increased risk for a host of diseases, such as hypertension, diabetes, and dyslipidemia, independent of body mass index. To date, no study has examined the effect of Internet-based lifestyle interventions on waist circumference change. This study aimed to systematically review the effect of Internet-based interventions on waist circumference change among adults. This meta-analysis reviewed randomized controlled trials (N=31 trials and 8442 participants) that used the Internet as a main intervention approach and reported changes in waist circumference. Internet-based interventions showed a significant reduction in waist circumference (mean change -2.99 cm, 95% CI -3.68 to -2.30, I(2)=93.3%) and significantly better effects on waist circumference loss (mean loss 2.38 cm, 95% CI 1.61-3.25, I(2)=97.2%) than minimal interventions such as information-only groups. Meta-regression results showed that baseline waist circumference, gender, and the presence of social support in the intervention were significantly associated with waist circumference reduction. Internet-based interventions have a significant and promising effect on waist circumference change. Incorporating social support into an Internet-based intervention appears to be useful in reducing waist circumference. Considerable heterogeneity exists among the effects of Internet-based interventions. The design of an intervention may have a significant impact on the effectiveness of the intervention.
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CIRCE: A dedicated storage ring for coherent THz synchrotron radiation
International Nuclear Information System (INIS)
Byrd, J.M.; Martin, Michael C.; McKinney, W.R.; Munson, D.V.; Nishimura, H.; Robin, D.S.; Sannibale, F.; Schlueter, R.D.; Thur, W.G.; Jung, J.Y.; Wan, W.
2003-01-01
We present the concepts for an electron storage ring dedicated to and optimized for the production of stable coherent synchrotron radiation (CSR) over the far-infrared terahertz wavelength range from 200 mm to about one cm. CIRCE (Coherent InfraRed CEnter) will be a 66 m circumference ring located on top of the ALS booster synchrotron shielding tunnel and using the existing ALS injector. This location provides enough floor space for both the CIRCE ring, its required shielding, and numerous beamlines. We briefly outline a model for CSR emission in which a static bunch distortion induced by the synchrotron radiation field is used to significantly extend the stable CSR emission towards higher frequencies. This model has been verified with experimental CSR results. We present the calculated CIRCE photon flux where a gain of 6-9 orders of magnitude is shown compared to existing far-IR sources. Additionally, the particular design of the dipole vacuum chamber has been optimized to allow an excellent transmission of these far-infrared wavelengths. We believe that the CIRCE source can be constructed for a modest cost
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Fano resonance and persistent current of a quantum ring
International Nuclear Information System (INIS)
Xiong Yongjian; Liang Xianting
2004-01-01
We investigate electron transport and persistent current of a quantum ring weakly attached to current leads. Assuming there is direct coupling (weakly or strongly) between two leads, electrons can transmit by the inter-lead coupling or tunneling through the quantum ring. The interference between the two paths yields asymmetric Fano line shape for conductance. In presence of interior magnetic flux, there is persistent current along the ring with narrow resonance peaks. The positions of the conductance resonances and the persistent current peaks correspond to the quasibound levels of the closed ring. This feature is helpful to determine the energy spectrum of the quantum ring. Our results show that the proposed setup provides a tunable Fano system
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Vacuum system for the NIJI-III compact storage ring
International Nuclear Information System (INIS)
Miura, F.; Tsutsui, Y.; Takada, H.
1990-01-01
The NIJI-III is a compact storage ring measuring about 15 m in circumference with four superconducting bending magnets. It is under development as a synchrotron light source for X-ray lithography with a stored beam current of 200 mA at a stored beam current of 200 mA at a stored energy level of 615 MeV. The vacuum system is designed to attain a pressure of less than 1 x 10 -9 Torr at beam storage. The compact ring design makes it difficult to install a large number of pumps able to satisfy the required pumping speed. For the purpose of realizing a high pumping speed, a cryopump as a result of cooling the superconducting magnet duct wall to the liquid helium (LHe) temperature is adopted, as a result the total pumping speed to 2.8 x 10 4 l/s is obtained. (author)
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Energy Technology Data Exchange (ETDEWEB)
Danel, V; Plichon, V
1983-06-01
The rotating ring-disc electrode technique was used to study the generation of soluble Pb(II) species during the anodic oxidation of the lead electrode in various H/sub 2/O-H/sub 2/SO/sub 4/ media. The concentration range extended from 0.06 to 10.3 M H/sub 2/SO/sub 4/. For every concentration it was possible to detect small cathodic ring current variation which was attributable to the reduction of Pb(II) to Pb. Quantitative measurements of the collection efficiency showed that the small cycle life of the lead-acid batter in 5.6 M H/sub 2/SO/sub 4/ cannot be ascribed to the dissolution step.
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Beam Optics for FCC-ee Collider Ring
Oide, Katsunobu; Aumon, S; Benedikt, M; Blondel, A; Bogomyagkov, A V; Boscolo, M; Burkhardt, H; Cai, Y; Doblhammer, A; Haerer, B; Holzer, B; Koop, I; Koratzinos, M; Jowett, John M; Levichev, E B; Medina, L; Ohmi, K; Papaphilippou, Y; Piminov, P A; Shatilov, D N; Sinyatkin, S V; Sullivan, M; Wenninger, J; Wienands, U; Zhou, D; Zimmermann, F
2017-01-01
A beam optics scheme has been designed [ 1 ] for the Future Circular Collider- e + e − (FCC-ee). The main characteristics of the design are: beam energy 45 to 175 GeV, 100 km circumference with two interaction points (IPs) per ring, horizontal crossing angle of 30 mrad at the IP and the crab-waist scheme [ 2 ] with local chromaticity correction. The crab-waist scheme is implemented within the local chromaticity correction system without additional sextupoles, by reducing the strength of one of the two sextupoles for vertical chromatic correction at each side of the IP. So- called “tapering" of the magnets is applied, which scales all fields of the magnets according to the local beam energy to compensate for the effect of synchrotron radiation (SR) loss along the ring. An asymmetric layout near the interaction region reduces the critical energy of SR photons on the incoming side of the IP to values below 100 keV, while matching the geometry to the beam line of the FCC proton collider (FCC-hh) [ 3 ] as clos...
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Status of the Cryogenic Storage Ring (CSR)
Energy Technology Data Exchange (ETDEWEB)
Menk, Sebastian; Becker, Arno; Berg, Felix; Blaum, Klaus; Fellenberger, Florian; Froese, Michael; Goullon, Johannes; Grieser, Manfred; Krantz, Claude; Lange, Michael; Laux, Felix; Repnow, Roland; Schornikov, Andrey; Hahn, Robert von; Wolf, Andreas [Max-Planck-Institut fuer Kernphysik (MPIK), 69117 Heidelberg (Germany); Spruck, Kaija [Institut fuer Atom- und Molekuelphysik Justus-Liebig-Universitaet, 35392 Giessen (Germany)
2012-07-01
A novel cryogenic storage ring is currently under construction at the MPIK. By electrostatic ion optical elements, the 35 m circumference Cryogenic Storage Ring will be able to store ions at energies of up to 300 keV per charge unit without any mass limitations. The CSR consists of a cryogenic ({proportional_to}5 K) beam pipe surrounded by two radiation shields (40 and 80 K) in a large outer, thermal insulation vacuum. Extreme vacuum (density {proportional_to}10{sup 3} cm{sup -3}) will be achieved by 2 K cryopumping as demonstrated in a prototype ion beam trap. The ion optics was completely assembled within the precision cryogenic mounting and shielding structure of the first corner. There, cooldown tests to {proportional_to}40 K were performed which confirmed the required sub-millimeter accuracy of the specially designed electrode positioning under large temperature changes. The high-voltage connections to the cryogenic electrodes were installed and breakdown tests will be reported. Based on the test results the beam pipe, electrode mounting and shielding structures are under final construction for mounting during 2012.
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[Animal experimental study of compression anastomosis ring for low anterior resection].
Liang, Jian-Wei; Wang, Zheng; Zhang, Xing-Mao; Zhan, Da-Wei; Zhou, Zhi-Xiang
2011-05-01
To evaluate the feasibility and safety of nickel-titanium compression anastomosis ring (CAR27) in colorectal anastomosis after low anterior rectal resection in animal models. End-to-end colorectal anastomosis was performed using CAR27 in 6 experimental pigs after resection of the middle and lower third of the rectum. The animals were observed postoperatively for up to 56 days. Five pigs were sacrificed at day 14 and the other at day 56. Distance from anal verge to anastomosis and anastomotic circumference were measured. Histopathologic examination was performed. The median distance from anal verge was 5.3(4-6) cm. No anastomotic leak or other complications were observed. All the pigs recovered and gained weight. In 5 animals sacrificed at day 14, the mean circumference of the anastomosis was 6.8(6.5-7.0) cm, and histopathological examination showed mild inflammatory reaction and fibrosis. In the one sacrificed at day 56, the circumference expanded to 9.3 cm, and no inflammation and fibrosis were observed. Minor adhesion was noticed in only one pig, while smooth and intact serosa in the anastomosis was seen in the rest of the animals. CAR27 is a promising device for mid and low colorectal anastomosis.
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Thigh circumference and risk of heart disease and premature death
DEFF Research Database (Denmark)
Heitmann, Berit L; Frederiksen, Peder
2009-01-01
OBJECTIVE: To examine associations between thigh circumference and incident cardiovascular disease and coronary heart disease and total mortality. DESIGN: Prospective observational cohort study with Cox proportional hazards model and restricted cubic splines. SETTING: Random subset of adults...... in Denmark. PARTICIPANTS: 1436 men and 1380 women participating in the Danish MONICA project, examined in 1987-8 for height, weight, and thigh, hip, and waist circumference, and body composition by impedance. MAIN OUTCOME MEASURES: 10 year incidence of cardiovascular and coronary heart disease and 12.5 years...... of follow-up for total death. RESULTS: A small thigh circumference was associated with an increased risk of cardiovascular and coronary heart diseases and total mortality in both men and women. A threshold effect for thigh circumference was evident, with greatly increased risk of premature death below...
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Arm circumference: its importance for dialysis patients in the obesity era.
Akpolat, Tekin; Kaya, Coşkun; Utaş, Cengiz; Arinsoy, Turgay; Taşkapan, Hülya; Erdem, Emre; Yilmaz, M Emin; Ataman, Rezzan; Bozfakioğlu, Semra; Özener, Çetin; Karayaylali, Ibrahim; Kazancioğlu, Rümeyza; Çamsari, Taner; Yavuz, Mahmut; Ersoy, Fevzi; Duman, Soner; Ateş, Kenan
2013-08-01
The purposes of this study were to investigate the association between arm circumference and body mass index (BMI) and to discuss problems, mainly arm circumference and cuff size mismatch, that could affect the reliability of home blood pressure monitoring (HBPM) among peritoneal dialysis (PD) and hemodialysis (HD) patients. 525 PD and 502 HD patients from 16 centers were included in the study. A two-part questionnaire was used to gather information from the participants. Arm circumferences were categorized into four groups according to the British Hypertension Society cuff size recommendations. Mean BMI and arm circumference of all participants were 25.0 kg/m(2) and 27.6 cm, respectively. There was a significant correlation between BMI and arm circumference. The mean BMI and arm circumference values were higher in PD patients than in HD patients. Requirement of a large-sized adult cuff was more common among PD patients compared to HD patients (14 % vs 8 %, p = 0.002). Since HBPM is a useful tool for clinicians to improve BP control, nephrologists should be aware of the problems related to HBPM in dialysis patients and take an active role to increase the reliability of HBPM.
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Cabling design of booster and storage ring construction progress of TPS
International Nuclear Information System (INIS)
Wong, Y.-S.; Liu, K.-B.; Liu, C.-Y.; Wang, B.-S.
2017-01-01
The 2012 Taiwan Photon Source (TPS) cable construction project started after 10 months to complete the cable laying and installation of power supply. The circumference of the booster ring (BR) is 496.8 m, whereas that of the storage ring (SR) is 518.4 m. Beam current is set to 500 mA at 3.3 GeV. The paper on grounding systems discusses the design of the ground wire (< 0.2 Ω) with low impedance, power supply of the accelerator and cabling tray. The flow and size of the ground current are carefully evaluated to avoid grounded current from flowing everywhere, which causes interference problems. In the design of the TPS, special shielding will be established to isolate the effects of electromagnetic interference on the magnet and ground current. Booster ring dipoles are connected by a series of 54-magnet bending dipole; the cable size of its stranded wire measures 250 mm"2, with a total length of 5000 m. Booster ring and storage ring quadrupoles have 150 magnets; the cable size of their stranded wire is 250 mm"2, with a total length of 17000 m. Storage ring dipole consists of 48 magnets; the cable size of its stranded wire is 325 mm"2, with a total length of 6000 m. This study discusses the power supply cabling design of the storage ring and booster ring construction progress of TPS. The sections of this paper are divided into discussions of the construction of the control and instrument area, cabling layout of booster ring and storage ring, as well as the installation and commission machine. This study also discusses the use of a high-impedance meter to determine the effect of cabling insulation and TPS power supply machine on energy transfer to ensure the use of safe and correct magnet.
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Ring-element analysis of layered orthotropic bodies
DEFF Research Database (Denmark)
Jørgensen, O.
1993-01-01
For the analysis of arbitrarily laminated circular bodies, a displacement-based ring-element is presented. The analysis is performed in a cylindrical coordinate system. The method of analysis requires the boundary conditions as well as the external forces to be pi-periodic. The element formulation...... accounts for a desired degree of approximation of the displacement field in the direction of the circumference. This is done by a truncated Fourier expansion of the angular dependence of the displacements in terms of trigonometric functions. Thus the Fourier expansion coefficients are the unknowns...... to that of solutions obtained by traditional 3D elements. A scheme for analytical integration of the angular dependence of the stiffness matrix is given....
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Design of a 4.8-m ring for inverse Compton scattering x-ray source
Directory of Open Access Journals (Sweden)
H. S. Xu
2014-07-01
Full Text Available In this paper we present the design of a 50 MeV compact electron storage ring with 4.8-meter circumference for the Tsinghua Thomson scattering x-ray source. The ring consists of four dipole magnets with properly adjusted bending radii and edge angles for both horizontal and vertical focusing, and a pair of quadrupole magnets used to adjust the horizontal damping partition number. We find that the dynamic aperture of compact storage rings depends essentially on the intrinsic nonlinearity of the dipole magnets with small bending radius. Hamiltonian dynamics is found to agree well with results from numerical particle tracking. We develop a self-consistent method to estimate the equilibrium beam parameters in the presence of the intrabeam scattering, synchrotron radiation damping, quantum excitation, and residual gas scattering. We also optimize the rf parameters for achieving a maximum x-ray flux.
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Stressful life events in pregnancy and head circumference at birth
DEFF Research Database (Denmark)
Obel, Carsten; Hedegaard, Morten; Henriksen, Tine Brink
2003-01-01
A strong association between stress in pregnancy and small head circumference in infants at birth was reported in 1994. This important finding has never been replicated. In a follow-up study of 4211 participants with singleton pregnancies, information on life events was collected twice during...... pregnancy and head circumference measured shortly after birth following standard procedures. No association was found between experienced or perceived stress as a result of life events during pregnancy and head circumference in the infants. In conclusion, stress in pregnancy may influence foetal brain...
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CESAR, 2 MeV electron storage ring; general view.
CERN PhotoLab
1964-01-01
CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.
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Accuracy of self-reported height, weight and waist circumference in a Japanese sample.
Okamoto, N; Hosono, A; Shibata, K; Tsujimura, S; Oka, K; Fujita, H; Kamiya, M; Kondo, F; Wakabayashi, R; Yamada, T; Suzuki, S
2017-12-01
Inconsistent results have been found in prior studies investigating the accuracy of self-reported waist circumference, and no study has investigated the validity of self-reported waist circumference among Japanese individuals. This study used the diagnostic standard of metabolic syndrome to assess the accuracy of individual's self-reported height, weight and waist circumference in a Japanese sample. Study participants included 7,443 Japanese men and women aged 35-79 years. They participated in a cohort study's baseline survey between 2007 and 2011. Participants' height, weight and waist circumference were measured, and their body mass index was calculated. Self-reported values were collected through a questionnaire before the examination. Strong correlations between measured and self-reported values for height, weight and body mass index were detected. The correlation was lowest for waist circumference (men, 0.87; women, 0.73). Men significantly overestimated their waist circumference (mean difference, 0.8 cm), whereas women significantly underestimated theirs (mean difference, 5.1 cm). The sensitivity of self-reported waist circumference using the cut-off value of metabolic syndrome was 0.83 for men and 0.57 for women. Due to systematic and random errors, the accuracy of self-reported waist circumference was low. Therefore, waist circumference should be measured without relying on self-reported values, particularly in the case of women.
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Bosser, Jacques; Chanel, M; Hill, C; Lombardi, A M; MacCaferri, R; Maury, S; Möhl, D; Molinari, G; Rossi, S; Tanke, E; Tranquille, G; Vretenar, Maurizio
1999-01-01
This report gives the results of a programme of experimental investigations, which were carried out to test stacking of lead ions in a storage ring (the former Low Energy Antiproton Ring, LEAR) at 4.2 MeV per nucleon. The motivation was to demonstrate the feasibility of gaining the large factor in the phase-space density required for injection into the LHC. In the first part of the report, the layout of the experiments is described, the choice of the parameters of the electron cooling system used for stacking is reported and the multi-turn injection using horizontal- and longitudinal- (and in the final project also vertical-) phase space is discussed. In the second part the experimental results are presented. Factors of vital importance are the stacking efficiency, the beam life-time and the cooling time of the ions. The beam decay owing to charge exchange with the residual gas and to recombination by the capture of cooling electrons was intensively studied. Beam instabilities and space-charge effects in the ...
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Learning circumference concepts from the didactical situations theory perspective
Directory of Open Access Journals (Sweden)
Valdir de Sousa Cavalcanti
2013-08-01
Full Text Available The circumference study, as its importance, it is one of the most relevant contents in the Analytical Geometry curriculum. However, the complexity of related concepts to this theme linked to the content fragmentation, it difficulties the students thinking of transforming geometrical problems into equations solution, systems or inequations. Within, in this article we present a partial report of a master research work, of qualitative mode, which aimed to develop and to evaluate an alternative methodology by using musical parody composition to the teaching of Mathematics in trying to contribute to the circumference concepts learning process. For that, we carried out a case study with 36 third year high school students of a public school from the city of Campina Grande, Paraíba. The research work was based and discussed on Brousseau Didactical Situation Theory. It was chosen triangulation technique for the data analyses, collected from interviews, questionnaires and a list of mathematical exercises. We concluded that the parody composition resource allowed the students better understand the concepts of center, ratio, cord and the definition of the general circumference equation, as they were capable to identify the relative positions which a circumference assumes in relation to an equation of a straight line and between two circumferences in the various concepts that differentiated them. Thus, we can state that the musical parody composition as a didactical resource can contribute to the learning of mathematical contents.
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INJECTION EFFICIENCY IN COMPTON RING NESTOR
Directory of Open Access Journals (Sweden)
P. I. Gladkikh
2017-12-01
Full Text Available NESTOR is the hard X-ray source that is under commissioning at NSC KIPT. NESTOR based on the Compton scattering of laser photons on relativistic electrons. The structure of the facility can be represented as the following components: a linear accelerator, a transport channel, a storage ring, and a laser-optical system. Electrons are stored in the storage ring for energy of 40-200 MeV. Inevitable alignment errors of magnetic elements are strongly effect on the beam dynamics in the storage ring. These errors lead to a shift of the equilibrium orbit relative to the ideal one. Significant shift of the equilibrium orbit could lead to loss of the beam on physical apertures. Transverse sizes of electron and laser beams are only few tens of microns at the interaction point. The shift of electron beam at the interaction point could greatly complicate the operation adjustment of storage ring without sufficient beam position diagnostic system. This article presents the simulation results of the efficiency of electron beam accumulation in the NESTOR storage ring. Also, this article is devoted to electron beam dynamics due to alignment errors of magnetic element in the ring.
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Amplitude-modulated fiber-ring laser
DEFF Research Database (Denmark)
Caputo, J. G.; Clausen, Carl A. Balslev; Sørensen, Mads Peter
2000-01-01
Soliton pulses generated by a fiber-ring laser are investigated by numerical simulation and perturbation methods. The mathematical modeling is based on the nonlinear Schrödinger equation with perturbative terms. We show that active mode locking with an amplitude modulator leads to a self......-starting of stable solitonic pulses from small random noise, provided the modulation depth is small. The perturbative analysis leads to a nonlinear coupled return map for the amplitude, phase, and position of the soliton pulses circulating in the fiber-ring laser. We established the validity of this approach...
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Ionization cooling ring for muons
Directory of Open Access Journals (Sweden)
R. Palmer
2005-06-01
Full Text Available Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second U.S. Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such real-world effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49.
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Global Optimization of Damping Ring Designs Using a Multi-Objective Evolutionary Algorithm
Emery, Louis
2005-01-01
Several damping ring designs for the International Linear Collider have been proposed recently. Some of the specifications, such as circumference and bunch train, are not fixed yet. Designers must make a choice anyway, select a geometry type (dog-bone or circular), an arc cell type (TME or FODO), and optimize linear and nonlinear part of the optics. The design process include straightforward steps (usually the linear optics), and some steps not so straightforward (when nonlinear optics optimization is affected by the linear optics). A first attempt at automating this process for the linear optics is reported. We first recognize that the optics is defined by just a few primary parameters (e.g., phase advance per cell) that determine the rest (e.g., quadrupole strength). In addition to the exact specification of circumference, equilibrium emittance and damping time there are some other quantities which could be optimized that may conflict with each other. A multiobjective genetic optimizer solves this problem b...
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Fantin, Francesco; Comellato, Gabriele; Rossi, Andrea P; Grison, Elisa; Zoico, Elena; Mazzali, Gloria; Zamboni, Mauro
2017-09-01
Background Only a few studies have investigated the relationship between neck circumference and cardiometabolic risk. The aim of this study was to assess the relationships between neck circumference, waist circumference, metabolic variables and arterial stiffness in a group of overweight and obese subjects evaluating a possible independent role of neck circumference in determining arterial stiffness. Methods and results We studied 95 subjects (53 women) with an age range of 20-77 years and body mass index range from 25.69 to 47.04 kg/m 2 . In each subject we evaluated body mass index, waist, hip and neck circumference, systolic and diastolic blood pressure, insulin, fasting glucose, cholesterol, low-density lipoprotein and high-density lipoprotein cholesterol and triglycerides. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (PWVcf) and carotid-radial pulse wave velocity (PWVcr). Both PWVcf and PWVcr were higher in subjects with high values of neck circumference compared with subjects with normal values of neck circumference. Subjects with high values of neck circumference and abdominal obesity presented higher values of mean arterial pressure, PWVcr and homeostasis model assessment (HOMA) index and lower values of high-density lipoprotein than subjects with only abdominal obesity. Two models of stepwise multiple regression were performed in order to evaluate the combined effect of independent variables on arterial stiffness. In the first model PWVcf was considered a dependent variable, and age, gender, systolic blood pressure, triglycerides, high-density lipoprotein cholesterol, waist circumference, neck circumference, HOMA index and the use of anti-hypertensive medications were considered independent variables. Age, systolic blood pressure, triglycerides and waist circumference were significant predictors of PWVcf, explaining 65% of its variance. In the second model, in which PWVcr was considered a dependent variable, neck circumference
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Acceleration of magnetized plasma rings
International Nuclear Information System (INIS)
Hartman, D.; Eddleman, J.; Hammer, J.H.
1982-01-01
One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency
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Energy Technology Data Exchange (ETDEWEB)
Ngo, D. Q.; Petković, I., E-mail: ivana.petkovic@yale.edu; Lollo, A. [Department of Physics, Yale University, New Haven, Connecticut 06520 (United States); Castellanos-Beltran, M. A. [National Institute for Standards and Technology, Boulder, Colorado 80305 (United States); Harris, J. G. E. [Department of Physics, Yale University, New Haven, Connecticut 06520 (United States); Department of Applied Physics, Yale University, New Haven, Connecticut 06520 (United States)
2014-10-15
We have fabricated large arrays of mesoscopic metal rings on ultrasensitive cantilevers. The arrays are defined by electron beam lithography and contain up to 10{sup 5} rings. The rings have a circumference of 1 μm, and are made of ultrapure (6N) Au that is deposited onto a silicon-on-insulator wafer without an adhesion layer. Subsequent processing of the SOI wafer results in each array being supported at the end of a free-standing cantilever. To accommodate the large arrays while maintaining a low spring constant, the cantilevers are nearly 1 mm in both lateral dimensions and 100 nm thick. The extreme aspect ratio of the cantilevers, the large array size, and the absence of a sticking layer are intended to enable measurements of the rings' average persistent current in the presence of relatively small magnetic fields. We describe the motivation for these measurements, the fabrication of the devices, and the characterization of the cantilevers' mechanical properties. We also discuss the devices' expected performance in measurements of .
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Waist circumference as an indicator of high blood pressure in preschool obese children.
Chen, Bin; Li, Hai-fei
2011-01-01
To investigate the relationship between waist circumference and blood pressure (BP) to determine if waist circumference was an indicator of BP in preschool children. Body weight, height, waist circumference (WC), hip circumference, and blood pressure of 939 3-6-year-old preschool children were collected. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) in obese children were significantly higher than that in normal weight children in both sexes (phigh blood pressure in children of both sexes. Multiple linear stepwise regression analysis using SBP as the dependent variable showed that BMI and WC were significant independent factors that influence high blood pressure adjusted for age, WtHr and waist-to-hip circumference ratio (WHr) in boys. When using DBP as the dependent variable, BMI was the only significant independent factor that influenced high blood pressure adjusted for age, WtHr and WHr, in both sex-es. Waist circumference was independently associated with high blood pressure in boys aged 3-6 years. In addition to BMI, increased waist circumference was found to be an indicator of high blood pressure in the preschool children, especially in boys.
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Asynchronous slip-ring motor synchronized with permanent magnets
Directory of Open Access Journals (Sweden)
Glinka Tadeusz
2017-03-01
Full Text Available The electric LSPMSM motor presented in the paper differs from standard induction motor by rotor design. The insulated start-up winding is located in slots along the rotor circumference. The winding ends are connected to the slip-rings. The rotor core contains permanent magnets. The electromechanical characteristics for synchronous operation were calculated, as were the start-up characteristics for operation with a short-circuited rotor winding. Two model motors were used for the calculations, the V-shaped Permanent Magnet (VPM – Fig. 3, and the Linear Permanent Magnet (IPM – Fig. 4, both rated at 14.5 kW. The advantages of the investigated motor are demonstrated in the conclusions.
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CALF CIRCUMFERENCE AT BIRTH: A SCREENING METHOD FOR DETECTION OF LOW BIRTH WEIGHT
Directory of Open Access Journals (Sweden)
Sandip Kumar
2012-12-01
Full Text Available Background: Low Birth Weight (LBW babies run a higher risk of morbidity and mortality in the perinatal period. However, in our country where almost 70-80% births take place at home and peripheral hospitals, taking accurate weight is a problem due to unavailability of weighing scale and trained personnel. Hence there is a constant search for newer methods to detect LBW babies so that early interventions can be instituted. Various authors have used different surrogate anthropometric measurements from different parts of our country. In the present study, an attempt was made to validate the feasibility of using calf circumference as a predictor of LBW babies that can be used by a trained or untrained person. Objectives: To study various anthropometric measurements including calf circumference in newborns and to correlate various measurements with birth weight. Methods: The present study was conducted in the department of Social & Preventive Medicine, MLB Medical College, Jhansi (UP for a period of one year. The study included 1100 consecutively delivered neonates in the maternity ward of MLB Medical College Hospital, Jhansi (UP. The birth weight (Wt, crown heel length (CHL, crown rump length (CRL, head circumference (HC, chest circumference (CC, mid arm circumference (MAC, thigh circumference (TC and calf circumference (CC by standard techniques. All the measurements were taken by a single person throughout the study period with in 24 hours of delivery. Standard statistical methods were adopted for determination of critical limit, sensitivity, specificity and correlation coefficient of different anthropometric measurements in relation to birth weight. Results: Analysis of data indicates that out of 1100 newborns, 55.64% were low birth weight. The percentage of newborns > 2500gm was 44.36. Overall average birth weight was 2348 ± 505gm. Out of 1100 newborns, 608 (55.27% were males and 492 (44.73% were females. Average birth weight for males was 2412
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LHC - latest in a long line of rings
Energy Technology Data Exchange (ETDEWEB)
Anon.
1993-12-15
The LHC - Large Hadron Collider - ring in CERN's 27-kilometre LEP tunnel is the natural next link in an accelerator chain first forged in the mid-1950s with the decision to build Europe's first state-of-the-art high energy synchrotron at CERN. A lot of ground has been covered since the LHC idea was launched over a decade ago. While the basic machine design has moved through several iterations, preparations for the experimental programme are well underway. CERN is now responding to the December 1991 request from its governing body, Council, to supply detailed information on the technical feasibility of the machine, its costs, and its experimental programme. In the late 1970s, when plans for CERN's LEP electron-positron collider were being pieced together, far-sighted people were already looking further ahead. With the LEP tunnel itself a major investment for the future, the circumference of the ring and the tunnel cross-section were kept as large as possible, so that another ring could be fitted in when the time came. On the physics front, the ultimate quest was the mysterious higgs mechanism which controls electroweak symmetry breaking. The symmetry of the vacuum is broken by the higgs field. Somewhere along the line, this fundamental field has to show itself as one or more higgs particles.
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LHC - latest in a long line of rings
International Nuclear Information System (INIS)
Anon.
1993-01-01
The LHC - Large Hadron Collider - ring in CERN's 27-kilometre LEP tunnel is the natural next link in an accelerator chain first forged in the mid-1950s with the decision to build Europe's first state-of-the-art high energy synchrotron at CERN. A lot of ground has been covered since the LHC idea was launched over a decade ago. While the basic machine design has moved through several iterations, preparations for the experimental programme are well underway. CERN is now responding to the December 1991 request from its governing body, Council, to supply detailed information on the technical feasibility of the machine, its costs, and its experimental programme. In the late 1970s, when plans for CERN's LEP electron-positron collider were being pieced together, far-sighted people were already looking further ahead. With the LEP tunnel itself a major investment for the future, the circumference of the ring and the tunnel cross-section were kept as large as possible, so that another ring could be fitted in when the time came. On the physics front, the ultimate quest was the mysterious higgs mechanism which controls electroweak symmetry breaking. The symmetry of the vacuum is broken by the higgs field. Somewhere along the line, this fundamental field has to show itself as one or more higgs particles
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Indriani, Novi; Julie, Hongki
2017-08-01
According Nuranisa, the students' difficulties on a lesson about the circumference of a circle were to understand the concept of what was the circumference of a circle and solve problems associated with the circumference of a circle [8]. According Nuranisa, this is because the teacher only gives a formula to find the circumference of a circle without helping students to construct the formula [8]. The purposes of this study were (1) to develop the hypothetical learning trajectory (HLT) for the cycle circumference material, (2) to describe the student results from the HLT implementation. The type of research used in this research was the design research developed by Gravemeijer and Cobb (2006). According Gravemeijer and Cobb, the design research was divided into three stages: (1) preparing for the experiment, (2) design experiments, and (3) retrospective analysis [6]. In this study, researchers developed the student learning trajectories which were help students to construct their knowledge about the understanding and how to calculate the circumference of a circle. The context used on the students' learning trajectory was sports and arts event. The learning trajectory has been tried out for 15 grade five students on the Budya Wacana elementary school in Yogyakarta. In this paper, researchers would describe how the learning trajectory traversed students to construct their knowledge about the understanding and how to calculate the circumference of the circle and the student thinking process on the understanding and how to calculate the circumference of a circle. The results showed that students could construct about the understanding of the circumference of a circle and how to calculate the circumference of a circle through the student learning trajectory.
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Neck circumference as a potential marker of metabolic syndrome among college students
Pereira, Dayse Christina Rodrigues; Araújo, Márcio Flávio Moura de; Freitas, Roberto Wagner Júnior Freire de; Teixeira, Carla Regina de Souza; Zanetti, Maria Lúcia; Damasceno, Marta Maria Coelho
2014-01-01
OBJECTIVE: to relate neck circumference with metabolic syndrome and its criteria among college students.METHOD: cross-sectional study conducted with 702 college students in Fortaleza, CE, Brazil from September 2010 to June 2011. Socio-demographic data, waist circumference and neck circumference were collected together with blood pressure, fasting blood sugar, triglyceride levels, and HDL-C.RESULTS: 1.7% of the studied sample presented metabolic syndrome. Of these, 58.3% presented altered neck...
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Measuring waist circumference in disabled adults
Waninge, Aly; Ligthart, K A M; Kramer, J; Hoeve, S; van der Schans, Cees; Haisma, Hinke
2010-01-01
To date, it is unknown whether waist circumference can be measured validly and reliably when a subject is in a supine position. This issue is relevant when international standards for healthy participants are applied to persons with severe intellectual, sensory, and motor disabilities. Thus, the
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Combined influence of leisure time physical activity and hip circumference on all-cause mortality
DEFF Research Database (Denmark)
Østergaard, Jane Nautrup; Grønbæk, Morten; Ängquist, Lars Henrik
2013-01-01
Hip circumference has been shown to be inversely associated with mortality. Muscle atrophy in the gluteofemoral region may be a possible explanation and thus physical activity is likely to play an important role. We aimed to estimate the combined effects of hip circumference and physical activity...... followed to 2009 in the Danish Civil Registration System, with 1.3% loss to follow-up and 2513 deaths. Hazard ratios (HR) were estimated for combinations of physical activity and hip circumference. Hip circumference was inversely associated with mortality irrespective of being physically active or not....... However, being physically active seemed to counterbalance some of the adverse health effects of a small hip circumference; when comparing inactive to active, the excess mortality at the 25(th) percentile of hip circumference is 40% in men (HR= 1.40, 95% CI: 1.14-1.72) and 33% in women (HR= 1.33, CI: 1...
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Relationship Between Neck Circumference and Epicardial Fat Thickness in a Healthy Male Population
Directory of Open Access Journals (Sweden)
Uğur Küçük
2016-01-01
Full Text Available Abstract Background: Epicardial fat is an upper body visceral fat depot that may play a significant role in the development of adverse metabolic and cardiovascular risk profiles. There is a significant direct relationship between the amount of epicardial fat and general body adiposity (body mass index, BMI, but data regarding subcutaneous adiposity is limited. Objective: We conducted a study to determine the association between neck circumference and epicardial fat thickness in healthy young male individuals, and assess their individual correlations with general body adiposity and cardiometabolic risk factors. Methods: One hundred consecutive male patients aged 18 years or older with no known major medical conditions were included in the study. All participants underwent detailed physical examination including measurement of blood pressure, weight, height, waist/hip ratio, and neck circumference. Blood was collected to determine fasting glucose and lipid parameters. A standard echocardiographic examination was performed with additional epicardial fat thickness determination. Results: Among 100 study participants, neck circumference correlated significantly with weight, waist circumference, BMI, blood glucose, serum total cholesterol, low-density (LDL-cholesterol, and triglycerides levels. No significant correlation was found between neck circumference and high-density lipoprotein (HDL-cholesterol levels. Neck circumference correlated moderately and positively with echocardiographic epicardial fat thickness. Conclusion: Among patients with low cardiometabolic risk, increased neck circumference was associated with increased epicardial fat thickness.
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CESAR, 2 MeV electron storage ring; general view from above.
Service Photo; CERN PhotoLab
1967-01-01
CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.
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Developments at an electrostatic cryogenic storage ring for electron-cooled keV energy ion beams
International Nuclear Information System (INIS)
Vogel, Stephen
2016-01-01
This work is devoted to final setup activities and the commissioning of an electrostatic cryogenic storage ring (CSR) at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg. The first cryogenic operation of CSR in 2015 has been documented and characterized using a set of non-destructive beam diagnostic tools developed within this work. These are (1) the current pick-up system for the determination of the current of the stored ion beam and its velocity, (2) a position pick-up system for measuring the transverse position of the ion beam center at six symmetric locations of the storage ring circumference, and (3) a Schottky pick-up system for the monitoring of coasting ion beams. Despite the requirements imposed by the cryogenic operation, the developed diagnostic system demonstrated its full functionality. First characterizations of the storage ring properties and the performance of the diagnostic system are presented. Based on previous work, an electron cooling system for CSR has been developed and largely realized. With the implementation into CSR in 2016, the electron cooler will enhance the storage ring into a unique experimental facility for electron-ion collision studies. With this CSR is on the track to become the first cryogenic storage ring featuring actively cooled ion beams.
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S.M. Boito; J.A.M. Laudij (Jacqueline); P.C. Struijk (Pieter); Th. Stijnen (Theo); J.W. Wladimiroff (Juriy)
2002-01-01
textabstractPURPOSE: To establish reproducibility and normal values for fetal hepatic volume and its significance in identification of fetal growth restriction relative to head and upper abdominal circumferences according to a cross-sectional study design. MATERIALS AND METHODS:
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1995-01-01
In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and
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Planetary ring systems properties, structures, and evolution
Murray, Carl D
2018-01-01
Planetary rings are among the most intriguing structures of our solar system and have fascinated generations of astronomers. Collating emerging knowledge in the field, this volume reviews our current understanding of ring systems with reference to the rings of Saturn, Uranus, Neptune, and more. Written by leading experts, the history of ring research and the basics of ring–particle orbits is followed by a review of the known planetary ring systems. All aspects of ring system science are described in detail, including specific dynamical processes, types of structures, thermal properties and their origins, and investigations using computer simulations and laboratory experiments. The concluding chapters discuss the prospects of future missions to planetary rings, the ways in which ring science informs and is informed by the study of other astrophysical disks, and a perspective on the field's future. Researchers of all levels will benefit from this thorough and engaging presentation.
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Waist circumference does not predict circulating adiponectin levels in sub-Saharan women
Directory of Open Access Journals (Sweden)
Gautier Jean-François
2007-10-01
Full Text Available Abstract Background Because of previously reported ethnic differences in determinants and markers of obesity and related metabolic disorders, we sought to investigate circulating levels of adiponectin and their correlates in a sub-Saharan African (sSA population. Subjects and Methods We studied 70 non-diabetic volunteers (33M/37F living in Yaoundé, Cameroon, aged 24–69 yr, with BMI 20–42 kg/m2. In all participants we measured waist circumference and total body fat by bioimpedance, and obtained a fasting venous blood sample for measurement of plasma glucose, serum insulin and adiponectin concentrations. We performed a euglycaemic hyperinsulinaemic clamp in 1/4 subjects, and HOMAIR was used as surrogate of fasting insulin sensitivity index since it best correlates to clamp measurements. Results Males had lower adiponectin levels than females (8.8 ± 4.3 vs. 11.8 ± 5.5 μg/L. There was no significant correlation between adiponectin and total body fat (rs = -0.03; NS, whereas adiponectin was inversely correlated with waist circumference (rs = -0.39; p = 0.001. Adiponectin correlated negatively with insulin resistance (rs = -0.35; p = 0.01. In a regression analysis using fasting adiponectin concentration as the dependent variable, and age, HOMAIR, waist circumference, and fat mass as predictors, waist circumference (β = -3.30; p = 0.002, fat mass (β = -2.68; p = 0.01, and insulin resistance (β = -2.38; p = 0.02 but not age (β = 1.11; p = 0.27 were independent predictors of adiponectin. When considering gender, these relations persisted with the exception of waist circumference in females. Conclusion Adiponectin correlates in this study population are comparable to those observed in Caucasians with the exception of waist circumference in women. The metabolic significance of waist circumference is therefore questioned in sSA women.
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Energy spectra of quantum rings.
Fuhrer, A; Lüscher, S; Ihn, T; Heinzel, T; Ensslin, K; Wegscheider, W; Bichler, M
2001-10-25
Quantum mechanical experiments in ring geometries have long fascinated physicists. Open rings connected to leads, for example, allow the observation of the Aharonov-Bohm effect, one of the best examples of quantum mechanical phase coherence. The phase coherence of electrons travelling through a quantum dot embedded in one arm of an open ring has also been demonstrated. The energy spectra of closed rings have only recently been studied by optical spectroscopy. The prediction that they allow persistent current has been explored in various experiments. Here we report magnetotransport experiments on closed rings in the Coulomb blockade regime. Our experiments show that a microscopic understanding of energy levels, so far limited to few-electron quantum dots, can be extended to a many-electron system. A semiclassical interpretation of our results indicates that electron motion in the rings is governed by regular rather than chaotic motion, an unexplored regime in many-electron quantum dots. This opens a way to experiments where even more complex structures can be investigated at a quantum mechanical level.
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BMI and waist circumference as indicators of health among Samoan women.
Novotny, Rachel; Nabokov, Vanessa; Derauf, Christopher; Grove, John; Vijayadeva, Vinutha
2007-08-01
High rates of obesity and chronic disease make establishment of effective indicators of risk for chronic disease important. The objective was to examine adequacy of anthropometric cut-off points as indicators of risk for chronic disease among Samoan women in Hawaii. A cross-sectional survey of 55 Samoan women 18 to 28 years of age that included blood lipids, cholesterol, and glucose (including after a 2-hour oral glucose test); anthropometry (weight, height, waist circumference); and DXA of body composition. Using the Centers for Disease Control and Prevention (CDC)/World Health Organization (WHO) cut-off points for BMI, 22% of women were overweight and 58% were obese. Cholesterol, lipid, and glucose values were all linearly related to DXA body fat, BMI, and waist circumference. BMI and waist circumference at WHO/NIH cut-off points predicted levels of blood lipids and glucose that indicate elevated risk for disease. WHO/NIH cut-off points for BMI and waist circumference reflect risk indicators of chronic disease among young Samoan women in Hawaii.
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Association between blood Pressure, waist circumference ...
African Journals Online (AJOL)
Objective: Blood pressure (BP) is one of the main cardiovascular risk indicators, but studies on its relationship with waist circumference, triglycerides and cholesterol are rare in low and middle income countries and even non-existent in some areas like the north of Cameroon. The aim of our study was to determine the ...
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Akın, S; Mucuk, S; Öztürk, A; Mazıcıoğlu, M; Göçer, Ş; Arguvanlı, S; Şafak, E D
2015-10-01
The aim of this study was to determine the prevalence of muscle strength-based sarcopenia and to determine possible predictors. This is a cross-sectional population-based study in the community-dwelling Turkish elderly. Anthropometric measurements, namely body height, weight, triceps skin fold (TSF), mid upper arm circumference (MUAC), waist circumference (WC) and calf circumference (CC), were noted. The midarm muscle circumference (MAMC) was calculated by using MUAC and TSF measurement. Sarcopenia was assessed, adjusted for body mass index (BMI) and gender, according to muscle strength. Physical performance was determined by 4 m walking speed (WS; m/s). The receiver operating curve analysis was performed to determine cut-offs of CC, MAMC and 4 m WS. A total of 879 elderly subjects, 50.1% of whom were female, were recruited. The mean handgrip strength (HGS) and s.d. was 24.2 (8.8) kg [17.9 (4.8) female, 30.6 (7.1) male]. The muscle function-dependent sarcopenia was 63.4% (female 73.5%, male 53.2%). The muscle mass-dependent sarcopenia for CC (sarcopenia. An adequate muscle mass may not mean a reliable muscle function. Muscle function may describe sarcopenia better compared with muscle mass. The CC, MAMC and 4 m WS cut-offs may be used to assess sarcopenia in certain age groups.
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The cryogenic storage ring CSR
von Hahn, R.; Becker, A.; Berg, F.; Blaum, K.; Breitenfeldt, C.; Fadil, H.; Fellenberger, F.; Froese, M.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; Heber, O.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lange, M.; Laux, F.; Lohmann, S.; Menk, S.; Meyer, C.; Mishra, P. M.; Novotný, O.; O'Connor, A. P.; Orlov, D. A.; Rappaport, M. L.; Repnow, R.; Saurabh, S.; Schippers, S.; Schröter, C. D.; Schwalm, D.; Schweikhard, L.; Sieber, T.; Shornikov, A.; Spruck, K.; Sunil Kumar, S.; Ullrich, J.; Urbain, X.; Vogel, S.; Wilhelm, P.; Wolf, A.; Zajfman, D.
2016-06-01
An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm-3 is derived, equivalent to a room-temperature pressure below 10-14 mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.
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The cryogenic storage ring CSR.
von Hahn, R; Becker, A; Berg, F; Blaum, K; Breitenfeldt, C; Fadil, H; Fellenberger, F; Froese, M; George, S; Göck, J; Grieser, M; Grussie, F; Guerin, E A; Heber, O; Herwig, P; Karthein, J; Krantz, C; Kreckel, H; Lange, M; Laux, F; Lohmann, S; Menk, S; Meyer, C; Mishra, P M; Novotný, O; O'Connor, A P; Orlov, D A; Rappaport, M L; Repnow, R; Saurabh, S; Schippers, S; Schröter, C D; Schwalm, D; Schweikhard, L; Sieber, T; Shornikov, A; Spruck, K; Sunil Kumar, S; Ullrich, J; Urbain, X; Vogel, S; Wilhelm, P; Wolf, A; Zajfman, D
2016-06-01
An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm(-3) is derived, equivalent to a room-temperature pressure below 10(-14) mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.
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The cryogenic storage ring CSR
Energy Technology Data Exchange (ETDEWEB)
Hahn, R. von; Becker, A.; Berg, F.; Blaum, K.; Fadil, H.; Fellenberger, F.; Froese, M.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lange, M.; Laux, F.; Lohmann, S.; Menk, S. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); and others
2016-06-15
An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm{sup −3} is derived, equivalent to a room-temperature pressure below 10{sup −14} mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.
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Directory of Open Access Journals (Sweden)
Menachem M. Meller
2014-01-01
Full Text Available The prevalence of class III obesity (BMI≥40 kg/m2 in black women is 18%. As class III obesity leads to hip joint deterioration, black women frequently present for orthopedic care. Weight loss associated with bariatric surgery should lead to enhanced success of hip replacements. However, we present a case of a black woman who underwent Roux-en-Y gastric bypass with the expectation that weight loss would make her a better surgical candidate for hip replacement. Her gastric bypass was successful as her BMI declined from 52.0 kg/m2 to 33.7 kg/m2. However, her hip circumference after weight loss remained persistently high. Therefore, at surgery the soft tissue tunnel geometry presented major challenges. Tunnel depth and immobility of the soft tissue interfered with retractor placement, tissue reflection, and surgical access to the acetabulum. Therefore a traditional cup placement could not be achieved. Instead, a hemiarthroplasty was performed. After surgery her pain and reliance on external support decreased. But her functional independence never improved. This case demonstrates that a lower BMI after bariatric surgery may improve the metabolic profile and decrease anesthesia risk, but the success of total hip arthroplasties remains problematic if fat mass in the operative field (i.e., high hip circumference remains high.
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Mid-upper arm circumference in pregnant women and its relation to birth weight
Directory of Open Access Journals (Sweden)
Ricalde Anamaría E.
1998-01-01
Full Text Available OBJECTIVE: In order to determine the relationship between some maternal anthropometric indicators and birth weight, crown-heel length and newborn's head circumference, 92 pregnant women were followed through at the prenatal service of hospital in S. Paulo, Brazil. MATERIAL AND METHOD: The following variables were established for the mother: weight, height, mid-upper arm circumference, pre-pregnancy weight, gestational weight gain and Quetelet's index. For the newborn the following variables were recorded: birth weight, crown-heel length, head circumference and gestational age by Dubowitz's method. RESULTS: Significant associations were noted between gestational age and newborn variables. In addition, maternal mid-arm circumference (MUAC and pre-pregnancy weight were found to be positively correlated to birth weight (r=0.399; r=0.378, respectively. The multivariate linear regression shows that gestational age, mother's arm circumference and pre-pregnancy weight continue to be significant predictors of birth weight. On the other hand, only gestational age and mother's age was associated with crown-heel length. Similarly MUAC was significantly associated with crown-heel length (r= 0.306; P=0.0030. CONCLUSION: Maternal mid-upper arm circumference is a potential indicator of maternal nutritional status. It could be used in association with other anthropometric measurements, instead of pre-pregnancy weight, as an alternative indicator to assess women at risk of poor pregnancy outcome.
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Mid-upper arm circumference in pregnant women and its relation to birth weight
Directory of Open Access Journals (Sweden)
Anamaría E. Ricalde
1998-04-01
Full Text Available OBJECTIVE: In order to determine the relationship between some maternal anthropometric indicators and birth weight, crown-heel length and newborn's head circumference, 92 pregnant women were followed through at the prenatal service of hospital in S. Paulo, Brazil. MATERIAL AND METHOD: The following variables were established for the mother: weight, height, mid-upper arm circumference, pre-pregnancy weight, gestational weight gain and Quetelet's index. For the newborn the following variables were recorded: birth weight, crown-heel length, head circumference and gestational age by Dubowitz's method. RESULTS: Significant associations were noted between gestational age and newborn variables. In addition, maternal mid-arm circumference (MUAC and pre-pregnancy weight were found to be positively correlated to birth weight (r=0.399; r=0.378, respectively. The multivariate linear regression shows that gestational age, mother's arm circumference and pre-pregnancy weight continue to be significant predictors of birth weight. On the other hand, only gestational age and mother's age was associated with crown-heel length. Similarly MUAC was significantly associated with crown-heel length (r= 0.306; P=0.0030. CONCLUSION: Maternal mid-upper arm circumference is a potential indicator of maternal nutritional status. It could be used in association with other anthropometric measurements, instead of pre-pregnancy weight, as an alternative indicator to assess women at risk of poor pregnancy outcome.
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Waist and hip circumferences and all-cause mortality: usefulness of the waist-to-hip ratio?
DEFF Research Database (Denmark)
Bigaard, J.; Frederiksen, K.; Tjønneland, A.
2004-01-01
inverse for both men and women, but only after adjustment for waist circumference, or BMI, or both. The mortality rate ratios of mutually adjusted waist and hip circumferences were 0.63 (95% CI: 0.56, 0.71), and 0.70 (95% CI: 0.63, 0.79) times higher per 10% larger hip circumference in men and women......, respectively, and 1.45 (95% CI: 1.34, 1.57) and 1.22 (95% CI: 1.14, 1.31) times higher per 10% larger waist circumference. The adequacy of the waist-to-hip ratio as a substitute for separate measurements of waist and hip circumferences depended on which other variables the analysis was adjusted for, indicating...... that the waist-to-hip ratio should be used with precaution. CONCLUSION: When mutually adjusted, waist and hip circumferences show opposite associations with all-cause mortality, probably due to different effects of adipose tissue in the abdominal and gluteofemoral regions. The waist-to-hip ratio cannot always...
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Thigh circumference and risk of heart disease and premature death: prospective cohort study
DEFF Research Database (Denmark)
Heitmann, Berit; Frederiksen, Peder
2009-01-01
OBJECTIVE: To examine associations between thigh circumference and incident cardiovascular disease and coronary heart disease and total mortality. DESIGN: Prospective observational cohort study with Cox proportional hazards model and restricted cubic splines. SETTING: Random subset of adults...... in Denmark. PARTICIPANTS: 1436 men and 1380 women participating in the Danish MONICA project, examined in 1987-8 for height, weight, and thigh, hip, and waist circumference, and body composition by impedance. MAIN OUTCOME MEASURES: 10 year incidence of cardiovascular and coronary heart disease and 12.5 years...... of follow-up for total death. RESULTS: A small thigh circumference was associated with an increased risk of cardiovascular and coronary heart diseases and total mortality in both men and women. A threshold effect for thigh circumference was evident, with greatly increased risk of premature death below...
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Interaction of Vortex Ring with Cutting Plate
Musta, Mustafa
2015-11-01
The interaction of a vortex ring impinging on a thin cutting plate was made experimentally using Volumetric 3-component Velocitmetry (v3v) technique. The vortex rings were generated with piston-cylinder vortex ring generator using piston stroke-to-diameter ratios and Re at 2-3 and 1500 - 3000, respectively. The cutting of vortex rings below center line leads to the formation of secondary vortices on each side of the plate which is look like two vortex rings, and a third vortex ring propagates further downstream in the direction of the initial vortex ring, which is previously showed by flow visualization study of Weigand (1993) and called ``trifurcation''. Trifurcation is very sensitive to the initial Reynolds number and the position of the plate with respect to the vortex ring generator pipe. The present work seeks more detailed investigation on the trifurcation using V3V technique. Conditions for the formation of trifurcation is analyzed and compared with Weigand (1993). The formed secondary vortex rings and the propagation of initial vortex ring in the downstream of the plate are analyzed by calculating their circulation, energy and trajectories.
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Leapfrogging of multiple coaxial viscous vortex rings
International Nuclear Information System (INIS)
Cheng, M.; Lou, J.; Lim, T. T.
2015-01-01
A recent theoretical study [Borisov, Kilin, and Mamaev, “The dynamics of vortex rings: Leapfrogging, choreographies and the stability problem,” Regular Chaotic Dyn. 18, 33 (2013); Borisov et al., “The dynamics of vortex rings: Leapfrogging in an ideal and viscous fluid,” Fluid Dyn. Res. 46, 031415 (2014)] shows that when three coaxial vortex rings travel in the same direction in an incompressible ideal fluid, each of the vortex rings alternately slips through (or leapfrogs) the other two ahead. Here, we use a lattice Boltzmann method to simulate viscous vortex rings with an identical initial circulation, radius, and separation distance with the aim of studying how viscous effect influences the outcomes of the leapfrogging process. For the case of two identical vortex rings, our computation shows that leapfrogging can be achieved only under certain favorable conditions, which depend on Reynolds number, vortex core size, and initial separation distance between the two rings. For the case of three coaxial vortex rings, the result differs from the inviscid model and shows that the second vortex ring always slips through the leading ring first, followed by the third ring slipping through the other two ahead. A simple physical model is proposed to explain the observed behavior
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Gender differences in waist circumference in Nigerian children ...
African Journals Online (AJOL)
Gender differences in waist circumference in Nigerian children. ... African Journal for Physical Activity and Health Sciences ... anthropometric tape according to the protocol of the International Society for the Advancement of Kinanthropometry ...
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Rashba diamond in an Aharonov-Casher ring
Wang, Xuhui
2011-10-07
Spin interference due to Rashba spin-orbit interaction(SOI) in a ballistic two-dimensional electron gas ring conductor submitted to a bias voltage is investigated theoretically. We calculate the scattering matrices and differential conductance with lead-ring junction coupling as an adjustable parameter. Due to the interference of electronic waves traversing the ring, the differential conductance modulated by both bias voltage and SOI exhibits a diamond-shaped pattern, thus termed as Rashba diamond. This feature offers a supplementary degree of freedom to manipulate phase interference.
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Rashba diamond in an Aharonov-Casher ring
Wang, Xuhui; Manchon, Aurelien
2011-01-01
Spin interference due to Rashba spin-orbit interaction(SOI) in a ballistic two-dimensional electron gas ring conductor submitted to a bias voltage is investigated theoretically. We calculate the scattering matrices and differential conductance with lead-ring junction coupling as an adjustable parameter. Due to the interference of electronic waves traversing the ring, the differential conductance modulated by both bias voltage and SOI exhibits a diamond-shaped pattern, thus termed as Rashba diamond. This feature offers a supplementary degree of freedom to manipulate phase interference.
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Extra Low Energy Antiproton ring ELENA : from the conception to the implementation phase
Bartmann, W; Breuker, H; Butin, F; Carli, C; Eriksson, T; Maury, S; Pasinelli, S; Tranquille, G; Oelert, W
2014-01-01
The Extra Low Energy Antiproton ring (ELENA) is a CERN project aiming at constructing a small 30 m circumference synchrotron to further decelerate antiprotons from the Antiproton Decelerator AD from 5.3 MeV to 100 keV. Controlled deceleration in a synchrotron equipped with an electron cooler to reduce emittances in all three planes will allow the existing AD experiments to increase substantially their antiproton capture efficiencies and render new experiments possible. The ELENA design is now well advanced and the project is moving to the implementation phase. Component design and construction are taking place at present for installation foreseen during the second half of 2015 and beginning of 2016 followed by ring commissioning until the end of 2016. New electrostatic transfer lines to the experiments will be installed and commissioned during the first half of 2017 followed by the first physics operation with ELENA. Basic limitations like Intra Beam Scattering limiting the emittances obtained under electron ...
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HISTRAP [Heavy Ion Storage Ring for Atomic Physics] vacuum test stand for pressures of 10-12 Torr
International Nuclear Information System (INIS)
Johnson, J.W.; Atkins, W.H.; Dowling, D.T.; McConnell, J.W.; Milner, W.T.; Olsen, D.K.
1988-01-01
HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed synchrotron/cooler/storage ring accelerator optimized for advanced atomic physics research. The ring has a circumference of 46.8 m, a bore diameter of about 15 cm, and requires a vacuum of 10 -12 Torr in order to decelerate highly-charged very-heavy ions down to low energies. To be able to test components and procedures to achieve this pressure, a test stand approximately modeling one-sixteenth of the ring vacuum chamber has been built. The 3.5-m-long test stand has been fabricated from 10-cm-diameter components, with 316LN stainless steel flanges. Prior to assembly, these components were vacuum fired at 950/degree/C at a pressure of 10 -4 Torr. The test stand is bakeable in situ at 300/degree/C. Pumping is achieved with two 750-L/s titanium sublimator pumps and one 60-L/s ion pump. Pressure is measured with two extractor ion gauges and a 10 -14 PP RGA. The roughing for the test stand consists of cryosorption pumps followed by a cryopump. A pressure of 4 x 10 -12 Torr has been achieved. 7 refs., 5 figs
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International Nuclear Information System (INIS)
Pivi, Mauro; Raubenheimer, Tor O.; Wang, Lanfa; Ohmi, Kazuhito; Wanzenberg, Rainer; Wolski, Andrzej
2007-01-01
In the beam pipe of the positron damping ring of the International Linear Collider (ILC), an electron cloud may be first produced by photoelectrons and ionization of residual gases and then increased by the secondary emission process. This paper reports the assessment of electron cloud effects in a number of configuration options for the ILC baseline configuration. Careful estimates were made of the secondary electron yield (sometimes in the literature also referred as secondary emission yield SEY or (delta), with a peak value (delta) max ) threshold for electron cloud build-up, and the related single- and coupled-bunch instabilities, as a function of beam current and surface properties for a variety of optics designs. When the configuration for the ILC damping rings was chosen at the end of 2005, the results from these studies were important considerations. On the basis of the joint theoretical and experimental work, the baseline configuration currently specifies a pair of 6 km damping rings for the positron beam, to mitigate the effects of the electron cloud that could present difficulties in a single 6 km ring. However, since mitigation techniques are now estimated to be sufficiently mature, a reduced single 6-km circumference is presently under consideration so as to reduce costs
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Supersymmetric rings in field theory
International Nuclear Information System (INIS)
Blanco-Pillado, Jose J.; Redi, Michele
2006-01-01
We study the dynamics of BPS string-like objects obtained by lifting monopole and dyon solutions of N = 2 Super-Yang-Mills theory to five dimensions. We present exact traveling wave solutions which preserve half of the supersymmetries. Upon compactification this leads to macroscopic BPS rings in four dimensions in field theory. Due to the fact that the strings effectively move in six dimensions the same procedure can also be used to obtain rings in five dimensions by using the hidden dimension
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He, Fang; He, Hua; Liu, Wenqi; Lin, Junyu; Chen, Bingjun; Lin, Yucong; Zhao, Yitao; Tao, Wen; Xia, Xuefeng
2017-03-01
A large neck circumference might be an indicator of metabolic syndrome and its components, and for certain patients is more practical as an index than waist circumference. The demarcation value for neck circumference that suggests metabolic syndrome appears to vary by ethnic group. Gestational diabetes mellitus is considered a component of metabolic syndrome in pregnant women. We investigated whether neck circumference in Han Chinese women is associated with gestational diabetes mellitus in early pregnancy, and determined a predictive demarcation value. A nested case-control study was carried out with 255 women aged 18-35 years. Gestational diabetes mellitus was diagnosed according to the criteria of the American Diabetes Association through a 2-h, 75-g oral glucose tolerance test. Of the total population, 41 (16%) women developed gestational diabetes mellitus by 24-28 weeks of gestation. Neck circumference at gestational week 16 positively correlated with pre-pregnancy waist circumference, bodyweight and body mass index, and maternal age (P = 0.029) and hemoglobin A1c at gestational week 24 (P ≤ 0.001). By binary logistic regression, neck circumference was an independent predictor of gestational diabetes mellitus (odds ratio 1.840, 95% confidence interval 1.040-3.254; P = 0.036). According to the receiver operating characteristic curve, for predicting gestational diabetes mellitus the optimal demarcation for neck circumference at gestational week 16 was 35.15 cm. Neck circumference is a viable tool to screen for gestational diabetes mellitus. In this population of pregnant Han Chinese women, a neck circumference of ≥35.15 cm was a predictor of gestational diabetes mellitus. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.
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Hosseini, Mostafa; Kelishadi, Roya; Yousefifard, Mahmoud; Qorbani, Mostafa; Bazargani, Behnaz; Heshmat, Ramin; Motlagh, Mohammad Esmail; Mirminachi, Babak; Ataei, Neamatollah
2017-01-01
We compared the prevalence of obesity based on both waist circumference for height and body mass index (BMI) in Iranian children and adolescents. Data on 13 120 children with a mean age of 12.45 ± 3.36 years (50.8% male) from the fourth Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable Disease study were included. Measured waist circumference values were modelled according to age, gender and height percentiles. The prevalence of obesity was estimated using the 90th percentiles for both unadjusted and height-adjusted waist circumferences and compared with the World Health Organization BMI cut-offs. They were analysed further for short, average and tall children. Waist circumference values increased steadily with age. For short and average height children, the prevalence of obesity was higher when height-adjusted waist circumference was used. For taller children, the prevalence of obesity using height-adjusted waist circumference and BMI was similar, but lower than the prevalence based on measurements unadjusted for height. Height-adjusted waist circumference and BMI identified different children as having obesity, with overlaps of 69.47% for boys and 68.42% for girls. Just using waist circumference underestimated obesity in some Iranian children and measurements should be adjusted for height. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
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Institute of Scientific and Technical Information of China (English)
ZHANG Lei; JIA Wei Ping; SHEN Yun; ZHOU Jian; PAN Jie Min; YU Hao Yong; CHEN Hai Bing; LI Qing; LI Ming; BAO Yu Qian
2014-01-01
Objective Waist circumference, as a brief indicator of visceral obesity, is associated with multi-metabolic disorders and cardiovascular diseases. The present study was aimed to find out the relationship between waist circumference and carotid intima media thickness (C-IMT), as well as the best waist circumference cutoff for identifying C-IMT elevation in Chinese male patients with newly-diagnosed diabetes. Methods Five hundred and seventy-eight patients from Department of Endocrinology and Metabolism in Shanghai Sixth People’s Hospital affiliated to Shanghai Jiao Tong University were enrolled. Both physical examination (for measurement of waist circumference) and carotid ultrasonography (for measurement of C-IMT) were performed. Results After grouping according to the quartiles of C-IMT, the waist circumference increased across all its quartiles. The waist circumference in 3rd and 4th quartiles (90.7±9.8 cm and 90.8±9.6 cm) was significant higher than in 1st and 2nd quartiles (P Conclusion Among newly-diagnosed diabetic male patients, waist circumference over 90 cm not only reflects sub-clinical atherosclerosis in early stage, but also predicts the progression of atherosclerosis.
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Vascular ring complicates accidental button battery ingestion.
Mercer, Ronald W; Schwartz, Matthew C; Stephany, Joshua; Donnelly, Lane F; Franciosi, James P; Epelman, Monica
2015-01-01
Button battery ingestion can lead to dangerous complications, including vasculoesophageal fistula formation. The presence of a vascular ring may complicate battery ingestion if the battery lodges at the level of the ring and its important vascular structures. We report a 4-year-old boy with trisomy 21 who was diagnosed with a vascular ring at the time of button battery ingestion and died 9 days after presentation due to massive upper gastrointestinal bleeding from esophageal erosion and vasculoesophageal fistula formation. Copyright © 2015 Elsevier Inc. All rights reserved.
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Pio-Magalhães, J A; Ferreira-Sae, M C; Souza, F A; Grespan-Magossi, A M; Schreiber, R; Velloso, L A; Geloneze, B; Franchini, K G; Nadruz, W
2011-10-01
This report investigated the relationship between anthropometric measurements of body fat distribution and lipid response to statins in hypercholesterolemic hypertensive patients. We prospectively examined 129 subjects who used either simvastatin 20 mg/day (no.=83) or atorvastatin 10 mg/day (no.=46) for 3 months. Anthropometry included evaluation of body mass index, waist and hip circumferences, and waist-to-hip-ratio. Significant decreases in LDL (pcorrelation between waist circumference and HDLcholesterol levels was detected (r=-0.18; p=0.04). Conversely, a direct relationship between hip circumference and HDLcholesterol response to statins was found in the whole sample (r=0.24; p=0.006), while no other anthropometric measurement displayed significant correlation with lipid changes. The association between HDL-cholesterol response and hip circumference was further confirmed by stepwise regression analysis adjusted for baseline HDL-cholesterol levels, metabolic syndrome, body mass index, and waist circumference. Hip circumference, a surrogate marker of peripheral adiposity, is associated with HDL-cholesterol changes following statin therapy in hypertensive patients.
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Relationship between waist circumference, visceral fat and ...
African Journals Online (AJOL)
Results: The prevalence was higher in women for enlarged waist circumference according to the pathological IDF or NCEP / ATP III threshold (p < 0.0001) contrasting with lower rates for pathological accumulation of visceral fat in men (p = 0.0001). The highest values for sensitivity and specificity were obtained for a ...
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Annular dynamics of memo3D annuloplasty ring evaluated by 3D transesophageal echocardiography.
Nishi, Hiroyuki; Toda, Koichi; Miyagawa, Shigeru; Yoshikawa, Yasushi; Fukushima, Satsuki; Yoshioka, Daisuke; Sawa, Yoshiki
2018-04-01
We assessed the mitral annular motion after mitral valve repair with the Sorin Memo 3D® (Sorin Group Italia S.r.L., Saluggia, Italy), which is a unique complete semirigid annuloplasty ring intended to restore the systolic profile of the mitral annulus while adapting to the physiologic dynamism of the annulus, using transesophageal real-time three-dimensional echocardiography. 17 patients (12 male; mean age 60.4 ± 14.9 years) who underwent mitral annuloplasty using the Memo 3D ring were investigated. Mitral annular motion was assessed using QLAB®version8 allowing for a full evaluation of the mitral annulus dynamics. The mitral annular dimensions were measured throughout the cardiac cycle using 4D MV assessment2® while saddle shape was assessed through sequential measurements by RealView®. Saddle shape configuration of the mitral annulus and posterior and anterior leaflet motion could be observed during systole and diastole. The mitral annular area changed during the cardiac cycle by 5.7 ± 1.8%.The circumference length and diameter also changed throughout the cardiac cycle. The annular height was significantly higher in mid-systole than in mid-diastole (p 3D ring maintained a physiological saddle-shape configuration throughout the cardiac cycle. Real-time three-dimensional echocardiography analysis confirmed the motion and flexibility of the Memo 3D ring upon implantation.
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Lead isotopes in tree rings: Chronology of pollution in Bayou Trepagnier, Louisiana
International Nuclear Information System (INIS)
Marcantonio, F.; Flowers, G.; Thien, L.; Ellgaard, E.
1998-01-01
The authors have measured the Pb isotopic composition of tree rings from seven trees in both highly contaminated and relatively noncontaminated regions of Bayou Trepagnier, a bayou in southern Louisiana that has had oil refinery effluent discharged into it over the past 70 years. To their knowledge, this is the first time that Pb isotope tree-ring records have been used to assess the sources and extent of heavy-metal contamination of the environment through time. When tree ring 206 Pb/ 208 Pb and 206 Pb/ 207 Pb isotope ratios are plotted against one another, a straight line is defined by four of the most contaminated trees. This linear correlation suggests mixing between two sources of Pb. One of the sources is derived from the highly polluted dredge spoils on the banks of the bayou and the other from the natural environment. The nature of the contaminant Pb is unique in that it is, isotopically, relatively homogeneous and extremely radiogenic, similar to ores of the Mississippi Valley (i.e., 206 Pb/ 207 Pb = 1.28). This singular pollutant isotope signature has enabled them to determine the extent of Pb contamination in each cypress wood sample. The isotope results indicate that Pb uptake by the tree is dominated by local-scale root processes and is, therefore, hydrologically and chemically controlled. In addition, the authors propose that the mobility and bioavailability of Pb in the environment depends on its chemical speciation
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Upper arm circumference measurement for detecting overweight and obesity in children aged 6-7 years
Directory of Open Access Journals (Sweden)
Dewi Rosariah Ayu
2017-02-01
Full Text Available Background Obesity is a worldwide problem and is associated with increased risk of metabolic syndrome. Nutritional status in children has traditionally been determined by body mass index (BMI scores, but with limitations. Upper arm circumference measurement may be a better predictor of energy, protein, and fat storage, as well as a simpler method for screening overweight and obesity in children. Objective To determine the diagnostic value of upper arm circumference compared to BMI for detecting overweight and obesity in children aged 6-7 years. Methods This diagnostic study with a cross-sectional design was performed from September to October 2015 at 16 primary schools in Palembang, Indonesia. We measured the heights, weights, and upper arm circumferences, and calculated BMIs of 2,258 children. Receiver-operator characteristic (ROC curve analysis was used to find an optimal upper arm circumference cut-off point to detect overweight and obesity. Diagnostic value was calculated by using a 2x2 table analysis. Results The prevalences of overweight and obesity were 5.8% and 11.7%, respectively. The optimal upper arm circumference cut-off points for detecting overweight in children aged 6-7 years was 185 mm (sensitivity 88.1% and specificity 78.3%, and for obesity was 195 mm (sensitivity 90.15% and specificity 86.65%. Upper arm circumference had a strong correlation with BMI. Conclusion Upper arm circumference measurement is an accurate method fordistinguishing between normoweight, overweight, and obesity in children aged 6-7 years.
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Hall-effect electric fields in semiconducting rings. II
International Nuclear Information System (INIS)
Gorodzha, L.V.; Emets, Yu.P.; Stril'ko, S.I.
1987-01-01
A calculation is presented for the current density distribution in a semiconducting ring with two electrodes symmetrically located on the outer boundary (system II, Fig. 1). The difference between this electrode position and that on the ring considered previously (system I) leads to substantial changes in the shape of the electric field
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The Jumping Ring and Lenz's Law--An Analysis
Bostock-Smith, J. M.
2008-01-01
Lenz's law is sometimes invoked to explain the behaviour of the jumping, or levitating, ring. This is shown to be incomplete, and an alternative explanation using Faraday's laws and circuit analysis is offered. This leads to the choice of optimum material and dimensions for the ring. (Contains 1 table and 4 figures.)
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Spin transitions in semiconductor quantum rings
International Nuclear Information System (INIS)
Baxevanis, Benjamin; Pfannkuche, Daniela
2010-01-01
We adopt the path integral Monte Carlo method to accurately resolve the total spin of the ground state of electrons confined in a quantum ring with different geometries. Using this method, an evaluation of the ground state of three electrons in a ring shows a spin transition to the fully polarized state by increasing the radius and thereby enhancing the Coulomb interaction. The total spin of the ground state is determined by the mutual interplay of confinement and electron-electron interaction. An analysis of the four-electron ring demonstrates that in this case no spin transitions take place. Furthermore, the effect of geometric distortion of the ring on its ground state has been investigated. Elliptically deforming the ring breaks the symmetry of the system and leads to the removal of orbital degeneracy. For strong distortion the splitting between hybridized states is sufficient to overcome the exchange-energy saving associated with a higher spin state. We have found that this effect removes the polarization of three electrons. Even in a four-electron ring the ground state is forced by the distortion to be unpolarized and thus suppressing the Hund's rule ground state.
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Common variants at 12q15 and 12q24 are associated with infant head circumference
DEFF Research Database (Denmark)
Taal, H Rob; St Pourcain, Beate; Thiering, Elisabeth
2012-01-01
To identify genetic variants associated with head circumference in infancy, we performed a meta-analysis of seven genome-wide association studies (GWAS) (N = 10,768 individuals of European ancestry enrolled in pregnancy and/or birth cohorts) and followed up three lead signals in six replication s......q21 signal have shown genome-wide association with adult intracranial volume, Parkinson's disease and other neurodegenerative diseases, indicating that a common genetic variant in this region might link early brain growth with neurological disease in later life....
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Saturn’s ring temperatures at equinox
Spilker, Linda J.; Ferrari, C.; Morishima, R.
2013-10-01
Modeling the thermal emission of Saturn's rings is challenging due to the numerous heating sources as well as the structural properties of the disk and of the particles that are closely related. At equinox, however, the main rings are externally heated by Saturn alone and the problem is somewhat simplified. We test the abilities of our current models to reproduce the temperatures observed with the Cassini CIRS instrument around equinox in August 2009. A simple semi-analytic model which includes mutual shadowing effects can mostly explain the radial profile of the equinox ring temperatures, except the model predicts lower temperatures than those observed for the A ring. The temperature variation at a given saturnocentric radius is primarily caused by observational geometry variations relative to Saturn. The observed temperature increases with decreasing Saturn-ring-observer angle. In addition, we found evidence that the leading hemispheres of particles are warmer than the trailing hemispheres at least for the C ring and probably for the A and B rings as well. This is explained if some fraction of particles has spin rates lower than the synchronous rotation rate as predicted by N-body simulations. The spin model for a monolayer ring (Ferrari, C., Leyrat, C., 2006, Astron. Astrophys. 447, 745-760) can fit the temperature variations with spacecraft longitude observed in the C ring with currently known thermal properties and a mixing of slow and fast rotators. The multilayer model (Morishima, R., Salo, H., Ohtsuki, K., 2009, Icarus 201, 634-654) can reproduce the temperatures of the B and C rings but gives A ring temperatures that are significantly lower than those observed as does the simple semi-analytic model. More advanced models which take into account self-gravity wakes may explain the A ring temperature behavior.
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International Nuclear Information System (INIS)
Bollini, Carlos Guido; Giambiagi, Mario; Giambiagi, Myriam Segre de; Figueiredo, Aloysio Paiva de
2001-02-01
Through the graphical method proposed it is possible to set a link between an MO multicenter bond index and VB structures. The value of the index depends on the order of the atoms involved if they are more than three. For 5-c rings three basic structures are required; the eventually different values are 12. Unlike the 6-c case it may happen that different pairs of basic structures are used to build the same polygon. For the 6-c rings including heteroatoms the original degeneracy of benzene splits leading eventually to 60 different I ring values. (author)
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biostatistical analysis of birth weight and head circumference
African Journals Online (AJOL)
URCHMAN
hypothesis that birth weight is independent of head circumference; birth weight is ... small head size called Microcephaly or very slow growth rate may indicate that .... Decision is to reject H0 if the F distribution with K degrees of freedom in the ...
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PREFACE: Special section on vortex rings Special section on vortex rings
Fukumoto, Yasuhide
2009-10-01
This special section of Fluid Dynamics Research includes five articles on vortex rings in both classical and quantum fluids. The leading scientists of the field describe the trends in and the state-of-the-art development of experiments, theories and numerical simulations of vortex rings. The year 2008 was the 150th anniversary of 'vortex motion' since Hermann von Helmholtz opened up this field. In 1858, Helmholtz published a paper in Crelle's Journal which put forward the concept of 'vorticity' and made the first analysis of vortex motion. Fluid mechanics before that was limited to irrotational motion. In the absence of vorticity, the motion of an incompressible homogeneous fluid is virtually equivalent to a rigid-body motion in the sense that the fluid motion is determined once the boundary configuration is specified. Helmholtz proved, among other things, that, without viscosity, a vortex line is frozen into the fluid. This Helmholtz's law immediately implies the preservation of knots and links of vortex lines and its implication is enormous. One of the major trends of fluid mechanics since the latter half of the 20th century is to clarify the topological meaning of Helmholtz's law and to exploit it to develop theoretical and numerical methods to find the solutions of the Euler equations and to develop experimental techniques to gain an insight into fluid motion. Vortex rings are prominent coherent structures in a variety of fluid motions from the microscopic scale, through human and mesoscale to astrophysical scales, and have attracted people's interest. The late professor Philip G Saffman (1981) emphasized the significance of studies on vortex rings. One particular motion exemplifies the whole range of problems of vortex motion and is also a commonly known phenomenon, namely the vortex ring or smoke ring. Vortex rings are easily produced by dropping drops of one liquid into another, or by puffing fluid out of a hole, or by exhaling smoke if one has the skill
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Novel Fiber-Optic Ring Acoustic Emission Sensor.
Wei, Peng; Han, Xiaole; Xia, Dong; Liu, Taolin; Lang, Hao
2018-01-13
Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.
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THE EFFECT OF WAIST CIRCUMFERENCES MORE THAN NORMAL ON THE INCIDENT OF CORONARY HEART DISEASE
Directory of Open Access Journals (Sweden)
Pria Wahyu
2017-07-01
Full Text Available Introduction: Coronary heart disease is known as the most common disease that causes mortality in the world, one of the examination to identify the risks of coronary heart disease is measuring waist circumference. The purpose of this study was to identify correlation between large waist circumferences and the incident of coroner heart disease. Method: Design used in this study was analytic observational (retrospective with cross sectional approach. There were 63 respondents which sampling by simple random sampling. The independent variable was waist circumferences and the dependent variable was coronary heart disease. Data were collected by direct observation then analyzed by spearman correlation statistic test with significance level α≤0.05. Result: The result showed that waist circumferences more than normal had significant correlation with the incident of coronary heart disease (p=0.02. Analysis: It can be concluded that there was correlation between waist circumferences more than normal and the incident of coronary heart disease to the clients with coroner cardiac disease. Discussion: Earlier screening and detection is needed to prevent coronary heart disease.
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Díez-Fernández, A; Martínez-Vizcaíno, V; Torres-Costoso, A; Cañete García-Prieto, J; Franquelo-Morales, P; Sánchez-López, M
2018-02-22
The aim of this study was to analyze the mediation role of cardiorespiratory fitness and waist circumference in the association between muscular strength and cardiometabolic risk. A cross-sectional study involved first-year college students (n = 370) from a Spanish public university was performed. We measured weight, height, waist circumference, blood pressure, biochemical variables, maximum handgrip strength assessment, and cardiorespiratory fitness. We calculated handgrip dynamometry/weight and a previously validated cardiometabolic risk index. Analysis of covariance models was conducted to test differences in cardiometabolic risk values across muscular strength, cardiorespiratory fitness, and waist circumference categories, controlling for confounders. Hayes' PROCESS macro was used for the multiple mediation analysis. The relationship between muscular strength and cardiometabolic risk did not remain significant (c' = 1.76 [1.4]; P > .05) in a multiple serial bootstrapped mediation model including cardiorespiratory fitness and waist circumference as mediators when controlling for age and sex. According to the indirect effect, the significant paths in the model mediating this relationship between muscular strength and cardiometabolic risk index were as follows: muscular strength → waist circumference → cardiometabolic risk index (-4.899; 95% CI: -6.690; -3.450) and muscular strength → cardiorespiratory fitness → waist circumference → cardiometabolic risk index (-0.720; 95% CI: -1.316; -0.360). Both cardiorespiratory fitness and waist circumference mediate the association between muscular strength and cardiometabolic risk in young adults. Thus, our results place cardiorespiratory fitness and waist circumference as the main targets of physical activity programmes aimed at preventing cardiometabolic diseases. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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Waist circumference as a predictor for blood glucose levels in adults
Directory of Open Access Journals (Sweden)
Shinta L Hardiman
2016-02-01
Full Text Available Anthropometric indexes such as body mass index (BMI, waist circumference (WC, hip ciucumference (HC, and waist–hip ratio (WHR, are all useful anthropometric measurements to provide important information on blood glucose concentrations. The aim of this study was to determine different anthropometric measurements, in particular BMI, waist circumference, hip circumference and waist-to-hip ratio, in their ability to predict the blood glucose levels in men and women 40 to 60. A cross-sectional study was conducted on a sample of 44 men and 127 women aged 40 to 50 who lived in Cipete Selatan subdistrict, South Jakarta. Blood glucose levels was assessed and anthropometric measurements comprising BMI, WC, HC, WHR were collected. Multiple linear regression analysis was used to determine the best predictor for blood glucose levels. The study showed that the prevalence of DM type 2 was 25.7% and the prevalence was higher in men (40.9% compared to women (23.5%. The significant predictive variables in the simple regression analysis were age and waist circumference. Multiple linear regression showed that after adjustment for age, WC was positively associated with blood glucose levels. Standardized a value was 0.172 (p=0.026. WC predict blood glucose levels, beyond that explained by traditional diabetic risk factors and BMI. These findings provide support for the recommendation that WC be a routine measure for identification of diabetes mellitus type 2 in men and women aged 40 to 60 years.
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Manuskiatti, W; Wachirakaphan, C; Lektrakul, N; Varothai, S
2009-07-01
A wide variety of treatments for circumference reduction and cellulite are available, but most procedures offer suboptimal clinical effect and/or delayed therapeutic outcome. Objective To determine the safety and efficacy of the TriPollar radiofrequency device for cellulite treatment and circumference reduction. Thirty-nine females with cellulite received eight weekly TriPollar treatments. Treatment areas included the abdomen, thighs, buttocks and arms. Subjects were evaluated using standardized photographs and measurements of body weight, circumference, subcutaneous thickness, and skin elasticity of the treatment sites at baseline, immediately after and 4 weeks after the final treatment. Physicians' evaluation of clinical improvement scores using a quartile grading scale was recorded. Thirty-seven patients (95%) completed the treatment protocol. There was significant circumference reduction of 3.5 and 1.7 cm at the abdomen (P = 0.002) and thigh (P = 0.002) regions, respectively. At 4 weeks after the last treatment, the average circumferential reductions of the abdomen and thighs were sustained. No significant circumferential reductions of the buttocks and arms at the last treatment visit compared to baseline were demonstrated (P = 0.138 and 0.152, respectively). Quartile grading scores correlating to approximately 50% improvement in cellulite appearance were noted. Tripollar radiofrequency provided beneficial effects on the reduction of abdomen and thigh circumference and cellulite appearance.
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Head Circumference in Autism, Asperger Syndrome and ADHD
Directory of Open Access Journals (Sweden)
J Gordon Millichap
2002-06-01
Full Text Available Occipitofrontal circumference (OFC, measured at birth and after 16 months of age, was compared in 50 consecutive patients with Asperger syndrome, 50 diagnosed with autistic disorder, and 50 with ADHD and followed at the Department of Child and Adolescent Psychiatry, Goteborg University, Sweden.
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Current density waves in open mesoscopic rings driven by time-periodic magnetic fluxes
International Nuclear Information System (INIS)
Yan Conghua; Wei Lianfu
2010-01-01
Quantum coherent transport through open mesoscopic Aharonov-Bohm rings (driven by static fluxes) have been studied extensively. Here, by using quantum waveguide theory and the Floquet theorem we investigate the quantum transport of electrons along an open mesoscopic ring threaded by a time-periodic magnetic flux. We predicate that current density waves could be excited along such an open ring. As a consequence, a net current could be generated along the lead with only one reservoir, if the lead additionally connects to such a normal-metal loop driven by the time-dependent flux. These phenomena could be explained by photon-assisted processes, due to the interaction between the transported electrons and the applied oscillating external fields. We also discuss how the time-average currents (along the ring and the lead) depend on the amplitude and frequency of the applied oscillating fluxes.
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Armen, Todd A; Vandse, Rashmi; Crestanello, Juan A; Raman, Subha V; Bickle, Katherine M; Nathan, Nadia S
2009-01-01
Left ventricular remodelling leads to functional mitral regurgitation resulting from annular dilatation, leaflet tethering, tenting, and decreased leaflet coaptation. Mitral valve annuloplasty restores valve competency, improving the patient's functional status and ventricular function. This study was designed to evaluate the mechanisms underlying mitral valve competency after the implantation of a Geoform annuloplasty ring using three-dimensional (3D) echocardiography. Seven patients (mean age of 65 years) with ischaemic mitral regurgitation underwent mitral valve annuloplasty with the Geoform ring and coronary artery bypass surgery. Pre- and post-operative 3D echocardiograms were performed. Following mitral annuloplasty, mitral regurgitation decreased from 3.4+/-0.2 to 0.9+/-0.3 (P-value<0.0001), mitral valve tenting volume from 13+/-1.7 to 3.2+/-0.3 mL (P-value<0.001), annulus area from 12.6+/-1.0 to 3.3+/-0.2 cm2 (P-value<0.0001), valve circumference from 13+/-0.5 to 7.3+/-0.3 cm (P-value<0.0001), septolateral distance from 2.1+/-0.1 to 1.4+/-0.06 cm (P-value<0.01) and intercommissural distance from 3.4+/-0.1 to 2.7+/-0.03 cm (P-value<0.03). There was significant decrease in the septolateral distance at the level of A2-P2 with respect to other regions. These geometric changes were associated with the improvement in the NYHA class from 3.1+/-0.3 to 1.3+/-0.3 (P-value<0.002). The mitral valve annuloplasty with the Geoform ring restores leaflet coaptation and eliminates mitral regurgitation by effectively modifying the mitral annular geometry.
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Beuret, A; Blas, A; Burkhardt, H; Carli, Christian; Chanel, M; Fowler, A; Gourber-Pace, M; Hancock, S; Hourican, M; Hill, C E; Jowett, John M; Kahle, K; Küchler, D; Lombardi, A M; Mahner, E; Manglunki, Django; Martini, M; Maury, S; Pedersen, F; Raich, U; Rossi, C; Royer, J P; Schindl, Karlheinz; Scrivens, R; Sermeus, L; Shaposhnikova, Elena; Tranquille, G; Vretenar, Maurizio; Zickler, T
2004-01-01
A sizeable part of the LHC physics programme foresees lead-lead collisions with a design luminosity of 1027 cm-2 s-1. This will be achieved after an upgrade of the ion injector chain comprising Linac3, LEIR, PS and SPS machines [1,2]. Each LHC ring will be filled in 10 min by almost 600 bunches, each of 7×107 lead ions. Central to the scheme is the Low Energy Ion Ring (LEIR) [3,4], which transforms long pulses from Linac3 into high-brilliance bunches by means of multi-turn injection, electron cooling and accumulation. Major limitations along the chain, including space charge, intrabeam scattering, vacuum issues and emittance preservation are highlighted. The conversion from LEAR (Low Energy Antiproton Ring) to LEIR involves new magnets and power converters, high-current electron cooling, broadband RF cavities, and a UHV vacuum system with getter (NEG) coatings to achieve a few 10-12 mbar. Major hardware changes in Linac3 and the PS are also covered. An early ion scheme with fewer bunches (but each at nominal...
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Maternal waist circumference as a prediction of children's stunted ...
African Journals Online (AJOL)
2014-05-08
May 8, 2014 ... Stunted Child and Overweight Mother (SCOM) pairs in a South African setting. After a ... this study measured waist circumference, while the Mexican group ... predictor of the mothers' children's metabolic syndrome status, but.
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Jara, Pascual; Torrecillas, Blas
1988-01-01
The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.
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Özkaya, İsmail; Tunçkale, Aydın
2016-06-01
According to the World Health Organization, central obesity is increasing alarmingly worldwide. Neck circumference is a relatively new method of differentiating between normal and abnormal fat distribution. The aim of this study is to determine the association between neck circumference and central obesity in young Turkish male and female university students. A community of university students based cross-sectional study was conducted on 319 males and 838 females and investigated the association between neck circumference and other anthropometric variables by gender. In male subjects, the neck circumference revealed a positive correlation with the body mass index (r=0.684, pobesity, is also applicable to university students. Copyright© by the National Institute of Public Health, Prague 2015.
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Head circumference, education and risk of dementia: findings from the Nun Study.
Mortimer, James A; Snowdon, David A; Markesbery, William R
2003-08-01
To examine the prevalence of dementia associated with having a smaller brain, lower education or both of these characteristics, 294 Catholic sisters were assessed annually for dementia. Sixty participants died and their brains were evaluated to determine fulfillment of neuropathological criteria for Alzheimer's disease (AD). Lower educational attainment and the interaction of smaller head circumference with lower education were associated with the presence of dementia, controlling for age and the presence of one or more apolipoprotein E-epsilon 4 alleles. By contrast, neither low educational attainment nor head circumference was significantly associated with fulfillment of neuropathological criteria for AD. Individuals having both low education and small head circumference were four times as likely to be demented as the rest of the sample. The findings suggest that higher education and larger head size, alone or in combination, may reduce the risk of expressing dementia in late life.
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Paciaroni, Nicholas G; Ratnayake, Ranjala; Matthews, James H; Norwood, Verrill M; Arnold, Austin C; Dang, Long H; Luesch, Hendrik; Huigens, Robert W
2017-03-28
High-throughput screening (HTS) is the primary driver to current drug-discovery efforts. New therapeutic agents that enter the market are a direct reflection of the structurally simple compounds that make up screening libraries. Unlike medically relevant natural products (e.g., morphine), small molecules currently being screened have a low fraction of sp 3 character and few, if any, stereogenic centers. Although simple compounds have been useful in drugging certain biological targets (e.g., protein kinases), more sophisticated targets (e.g., transcription factors) have largely evaded the discovery of new clinical agents from screening collections. Herein, a tryptoline ring-distortion strategy is described that enables the rapid synthesis of 70 complex and diverse compounds from yohimbine (1); an indole alkaloid. The compounds that were synthesized had architecturally complex and unique scaffolds, unlike 1 and other scaffolds. These compounds were subjected to phenotypic screens and reporter gene assays, leading to the identification of new compounds that possessed various biological activities, including antiproliferative activities against cancer cells with functional hypoxia-inducible factors, nitric oxide inhibition, and inhibition and activation of the antioxidant response element. This tryptoline ring-distortion strategy can begin to address diversity problems in screening libraries, while occupying biologically relevant chemical space in areas critical to human health. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Novel Fiber-Optic Ring Acoustic Emission Sensor
Directory of Open Access Journals (Sweden)
Peng Wei
2018-01-01
Full Text Available Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.
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Light-Ring Stability for Ultracompact Objects
Cunha, Pedro V. P.; Berti, Emanuele; Herdeiro, Carlos A. R.
2017-12-01
We prove the following theorem: axisymmetric, stationary solutions of the Einstein field equations formed from classical gravitational collapse of matter obeying the null energy condition, that are everywhere smooth and ultracompact (i.e., they have a light ring) must have at least two light rings, and one of them is stable. It has been argued that stable light rings generally lead to nonlinear spacetime instabilities. Our result implies that smooth, physically and dynamically reasonable ultracompact objects are not viable as observational alternatives to black holes whenever these instabilities occur on astrophysically short time scales. The proof of the theorem has two parts: (i) We show that light rings always come in pairs, one being a saddle point and the other a local extremum of an effective potential. This result follows from a topological argument based on the Brouwer degree of a continuous map, with no assumptions on the spacetime dynamics, and, hence, it is applicable to any metric gravity theory where photons follow null geodesics. (ii) Assuming Einstein's equations, we show that the extremum is a local minimum of the potential (i.e., a stable light ring) if the energy-momentum tensor satisfies the null energy condition.
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Report of the eRHIC Ring-Ring Working Group
Energy Technology Data Exchange (ETDEWEB)
Aschenauer, E. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brennan, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Palmer, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Parker, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Willeke, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)
2015-10-13
This report evaluates the ring-ring option for eRHIC as a lower risk alternative to the linac-ring option. The reduced risk goes along with a reduced initial luminosity performance. However, a luminosity upgrade path is kept open. This upgrade path consists of two branches, with the ultimate upgrade being either a ring-ring or a linac-ring scheme. The linac-ring upgrade could be almost identical to the proposed linac-ring scheme, which is based on an ERL in the RHIC tunnel. This linac-ring version has been studied in great detail over the past ten years, and its significant risks are known. On the other hand, no detailed work on an ultimate performance ring-ring scenario has been performed yet, other than the development of a consistent parameter set. Pursuing the ring-ring upgrade path introduces high risks and requires significant design work that is beyond the scope of this report.
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Beam optics simulation of rare-RI ring at RI beam factory in RIKEN
International Nuclear Information System (INIS)
Arai, I.; Ozawa, A.; Yasuda, Y.
2009-01-01
The cyclotron-like storage ring dedicated to Rare-RI Ring project consists of 6 magnetic sectors and 6 straight sections, having a circumference of 56.13 m. The magnetic sector works for both bending and focusing. The total circulation is assumed to be 1,000 turns. Over the momentum range from -1% to +1% in ∆p/p, the required isochronicity is 10 -6 while the beam emittance is several tens of π mm-mrad. To examine the design of cyclotron-like storage ring and fix its parameters, we have developed a high precision beam optics simulation. To achieve the precision as high as possible within a feasible computational time, we have adopted a geometrical tracking assuming a circular orbit for a small spatial segment. For that purpose, it is enough that the magnetic sector is divided into 150 sub-sectors in calculation. In each sub-sector, the magnetic field is given as a function of radial position but uniform around the vicinity of beam trajectory. The beam trajectory is evaluated in 4th order Runge-Kutta algorithm. Finally, we have achieved a precision of 10 -9 in ∆T/T and a computational time of 1.8 sec on a typical PC server for ray tracing of single particle undergoing a circulation of 1,000 turns. (author)
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The Effect of Uniform Background Flow on Vortex Ring Formation and Pinch-off
Krueger, Paul S.; Dabiri, John O.; Gharib, Morteza
2002-11-01
Experimental investigations of vortex ring formation are extended to include the effects of a uniform background flow, in a manner relevant to the locomotion of aquatic animals utilizing jet propulsion. Gharib et. al. [J. Fluid Mech. 360, 121 (1998)] generated vortex rings using a piston/cylinder apparatus with relatively large discharge times to demonstrate that the vortex ring at the leading edge of the jet attains its maximum circulation at a piston stroke-to-diameter ratio L/D of 4. This "formation number" is robust over a range of piston motions and cylinder boundary conditions, and can be explained in terms of the Kelvin-Benjamin variational principle. To determine the effect of background flow on formation number and pinch-off of the leading vortex ring, uniform co-flow is established in a large annulus surrounding the vortex generator. The ratio of co-flow velocity to piston velocity is varied between 0 and 1. In addition, the co-flow is initiated at times both before and after the start of vortex ring formation. We present results for stroke ratios L/D = 2 and L/D = 8, in order to discern effects of the co-flow on the leading vortex ring in isolation and in the presence of a trailing jet.
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DEFF Research Database (Denmark)
Bigaard, J.; Frederiksen, K.; Tjønneland, A.
2005-01-01
of waist circumference and body composition (body fat and fat-free mass), mutually adjusted, to all-cause mortality. DESIGN: A Danish prospective cohort study with a median follow-up period of 5.8 y. SUBJECTS: In all, 27 178 men and 29 875 women, born in Denmark, aged 50-64 y, and without diagnosis...... of cancer at the time of invitation. MEASUREMENTS: Waist circumference and body composition estimated from impedance measurements. Cox's regression models were used to estimate the mortality rate ratios (RR). RESULTS: Waist circumference was strongly associated with all-cause mortality after adjustment...... for body composition; the mortality RR was 1.36 (95% confidence intervals (CI): 1.22-1.52) times higher per 10% larger waist circumference among men and 1.30 (95% CI: 1.17-1.44) times higher among women. Adjustment for waist circumference eliminated the association between high values of the body fat mass...
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A leading-edge hardware family for diagnostics applications and low-level RF in CERN's ELENA ring
Angoletta, M E; Jaussi, M; Leiononen, P; Levens, T E; Molendijk, J C; Sanchez-Quesada, J; Simonin, J
2013-01-01
The CERN Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons transferred from the CERN’s Antiproton Decelerator (AD). The requirements for the acquisition and treatment of signals for longitudinal diagnostics are very demanding, owing to the revolution frequency swing as well as to the digital signal processing required. The requirements for the Low-Level Radio-Frequency (LLRF) system are very demanding as well, especially in terms of revolution frequency swing, dynamic range and low noise required by the cavity voltage control and digital signal processing to be performed. Both sets of requirements will be satisfied by using a leading-edge hardware family, developed to cover the LLRF needs of all synchrotrons in the Meyrin site; it will be first deployed in 2014 in the CERN’s PSB and in the medical machine MedAustron. This paper gives an overview of the main building blocks of the hardware family and of th...
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Digital closed orbit feedback system for the advanced photon source storage ring
International Nuclear Information System (INIS)
Chung, Y.; Barr, D.; Decker, G.
1995-01-01
The Advanced Photon Source (APS) is a dedicated third-generation synchrotron light source with a nominal energy of 7 GeV and a circumference of 1104 m. The closed orbit feedback system for the APS storage ring employs unified global and local feedback systems for stabilization of particle and photon beams based on digital signal processing (DSP). Hardware and software aspects of the system will be described in this paper. In particular, we will discuss global and local orbit feedback algorithms, PID (proportional, integral, and derivative) control algorithm, application of digital signal processing to compensate for vacuum chamber eddy current effects, resolution of the interaction between global and local systems through decoupling, self-correction of the local bump closure error, user interface through the APS control system, and system performance in the frequency and time domains. The system hardware including the DSPs is distributed in 20 VME crates around the ring, and the entire feedback system runs synchronously at 4-kHz sampling frequency in order to achieve a correction bandwidth exceeding 100 Hz. The required data sharing between the global and local feedback systems is facilitated via the use of fiber-optically-networked reflective memories
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Clark, Katherine; Snowball, Olivia; Nzelu, Diane; Kay, Polly; Kametas, Nikos A
2018-06-01
The Microlife WatchBP Home automated blood pressure device was assessed for accuracy in pregnant women of medium (arm circumference. The British Hypertension Society validation protocol was modified for the purpose of this study to include women with arm circumference of less than 32 cm (N=51) and greater than or equal to 32 cm (N=46) as two separate arms. The device achieved an overall A/A grade for medium arm circumference and B/A grade for large arm circumference. The mean±SD device-observer difference was 1.7±6.2 and -0.4±4.4 for systolic and diastolic blood pressure, respectively, for medium arm circumference and 3.0±8.5 and 1.5±5.1, respectively, for large arm circumference. When all women with pre-eclampsia from both groups were pooled (N=23), the device achieved an overall grade of A/A with mean differences of 2.1±7.2 for systolic blood pressure and 1.0±5.6 for diastolic blood pressure. The Microlife WatchBP Home automated blood pressure device can be recommended for use in pregnant women of all gestations, including those with pre-eclampsia. However, caution is needed for women with large arm circumferences.
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Configuration Studies and Recommendations for the ILC Damping Rings
International Nuclear Information System (INIS)
Wolski, Andrzej; Gao, Jie; Guiducci, Susanna
2006-01-01
We describe the results of studies comparing different options for the baseline configuration of the ILC damping rings. The principal configuration decisions apply to the circumference, beam energy, lattice type, and technology options for key components, including the injection/extraction kickers and the damping wigglers. To arrive at our recommended configuration, we performed detailed studies of a range of lattices representing a variety of different configuration options; these lattices are described in Chapter 2. The results of the various studies are reported in chapters covering issues of beam dynamics, technical subsystems, costs, and commissioning, reliability and upgrade ability. Our detailed recommendations for the baseline configuration are given in Chapter 7, where we also outline further research and development that is needed before a machine using our recommended configuration can be built and operated successfully. In the same chapter, we suggest possible alternatives to the baseline configuration
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Growth of planetisimals in a gaseous ring
International Nuclear Information System (INIS)
Hourigan, K.
1981-01-01
The aggregation of planetesimals in a gaseous ring leads to the development of a dominant body amongst the planetesimal population. The presence of the gas in the form of a differentially rotating ring serves to constrain the orbits of the planetesimals and grains to within a thin toroidal region through the action of gas drag. This situation allows for the efficient aggregation of bodies and, as a result of the low resultant relative velocites, the minimization of collisional fragmentation effects
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International Nuclear Information System (INIS)
Kamiya, Y.; Katoh, M.; Honjo, I.
1987-01-01
A future ring with a low emittance and large circumference, specifically dedicated to a synchrotron light source, will have a large chromaticity, so that it is important to employ a sophisticated sextupole correction as well as the design of linear lattice to obtain the stable beam. The authors tried a method of sextupole correction for a lattice with a large chromaticity and small dispersion function. In such a lattice the sextupole magnets are obliged to become large in strength to compensate the chromaticity. Then the nonlinear effects of the sextupole magnets will become more serious than their chromatic effects. Furthermore, a ring with strong quadrupole magnets to get a very small emittance and with strong sextupole magnets to compensate the generated chromaticity will be very sensitive to their magnetic errors. The authors also present simple formulae to evaluate the effects on the beam parameters. The details will appear in a KEK Report
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ASSOCIATIVE RINGS SOLVED AS LIE RINGS
Directory of Open Access Journals (Sweden)
M. B. Smirnov
2011-01-01
Full Text Available The paper has proved that an associative ring which is solvable of a n- class as a Lie ring has a nilpotent ideal of the nilpotent class not more than 3×10n–2 and a corresponding quotient ring satisfies an identity [[x1, x2, [x3, x4
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Díaz Villegas, Gregory Mishell; Runzer Colmenares, Fernando
2015-01-01
To evaluate the association between calf circumference and gait speed in elderly patients 65 years or older at Geriatric day clinic at Peruvian Centro Médico Naval. Cross-sectional, retrospective study. We assessed 139 participants, 65 years or older at Peruvian Centro Médico Naval including calf circumference, gait speed and Short Physical Performance Battery. With bivariate analyses and logistic regression model we search for association between variables. The age mean was 79.37 years old (SD: 8.71). 59.71% were male, the 30.97% had a slow walking speed and the mean calf circumference was 33.42cm (SD: 5.61). After a bivariate analysis, we found a calf circumference mean of 30.35cm (SD: 3.74) in the slow speed group and, in normal gait group, a mean of 33.51cm (SD: 3.26) with significantly differences. We used logistic regression to analyze association with slow gait speed, founding statistically significant results adjusting model by disability and age. Low calf circumference is associated with slow speed walk in population over 65 years old. Copyright © 2014. Published by Elsevier Espana.
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Hariadi, Rizal F; Appukutty, Abhinav J; Sivaramakrishnan, Sivaraj
2016-09-27
Nature has evolved molecular motors that are critical in cellular processes occurring over broad time scales, ranging from seconds to years. Despite the importance of the long-term behavior of molecular machines, topics such as enzymatic lifetime are underexplored due to the lack of a suitable approach for monitoring motor activity over long time periods. Here, we developed an "O"-shaped Myosin Empowered Gliding Assay (OMEGA) that utilizes engineered micron-scale DNA nanotube rings with precise arrangements of myosin VI to trap gliding actin filaments. This circular gliding assay platform allows the same individual actin filament to glide over the same myosin ensemble (50-1000 motors per ring) multiple times. First, we systematically characterized the formation of DNA nanotubes rings with 4, 6, 8, and 10 helix circumferences. Individual actin filaments glide along the nanotube rings with high processivity for up to 12.8 revolutions or 11 min in run time. We then show actin gliding speed is robust to variation in motor number and independent of ring curvature within our sample space (ring diameter of 0.5-4 μm). As a model application of OMEGA, we then analyze motor-based mechanical influence on "stop-and-go" gliding behavior of actin filaments, revealing that the stop-to-go transition probability is dependent on motor flexibility. Our circular gliding assay may provide a closed-loop platform for monitoring long-term behavior of broad classes of molecular motors and enable characterization of motor robustness and long time scale nanomechanical processes.
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Inelastic magnetic scattering of polarized neutrons by a superconducting ring
International Nuclear Information System (INIS)
Agafonov, A. I.
2011-01-01
The inelastic scattering of cold neutrons by a ring leads to quantum jumps of a superconducting current which correspond to a decrease in the fluxoid quantum number by one or several units while the change in the ring energy is transferred to the kinetic energy of the scattered neutron. The scattering cross sections of transversely polarized neutrons have been calculated for a thin type-II superconductor ring, the thickness of which is smaller than the field penetration depth but larger than the electron mean free path.
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Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS
Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.
2010-10-01
Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.
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The prediction of in-hospital mortality by mid-upper arm circumference
DEFF Research Database (Denmark)
Opio, Martin Otyek; Namujwiga, Teopista; Nakitende, Imaculate
2018-01-01
There are few reports of the association of nutritional status with in-hospital mortality of acutely ill medical patients in sub-Saharan Africa. This is a prospective observational study comparing the predictive value of mid-upper arm circumference (MUAC) of 899 acutely ill medical patients...... patients in a resource-poor hospital in sub-Saharan Africa....... admitted to a resource-poor sub-Saharan hospital with mental alertness, mobility and vital signs. Mid-upper arm circumference ranged from 15 cm to 42 cm, and 12 (24%) of the 50 patients with a MUAC less than 20 cm died (OR 4.84, 95% CI 2.23-10.37). Of the 237 patients with a MUAC more than 28 cm only six...
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Ring current energy injection rate and solar wind-magnetosphere energy coupling
International Nuclear Information System (INIS)
Lee, L.C.; Kan, J.R.; Akasofu, S.-I.
1982-01-01
The purpose of this paper is to (i) formulate the ring current injection rate Usub(R) in terms of phisub(CT) (cross-tail potential drop) by assuming that the ring current formation is a direct consequence of an enhanced convection, (ii) examine the relationship between the injection rate Usub(R) and the power transferred from the solar wind to the magnetosphere and (iii) demonstrate that an enhanced convection indeed leads to the formation of the ring current. (author)
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Waist circumference, BMI, and lung function in 8-year-old children : The PIAMA birth cohort study
Bekkers, Marga B. M.; Wijga, Alet H.; de Jongste, Johan C.; Kerkhof, Marjan; Postma, Dirkje; Gehring, Ulrike; Smit, Henriette A.; Brunekreef, Bert
Background Body mass index (BMI) and waist circumference (WC) may be associated with lung function in children, as observed in adults. Methods Height, weight, waist circumference, and lung function (FVC and FEV1) were measured during a medical examination in 1,058 eight-year-old children
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Directory of Open Access Journals (Sweden)
Xiang Shi
2016-11-01
Full Text Available This work discussed the optimized cut of single crystal lead magnoniobate titanate (PMNT for use of ring type travelling wave ultrasonic motors (USMs, according to anisotropic analysis on electromechanical properties. The selection criterion of crystal orientation relies on the circular uniformity of the induced travelling wave amplitude on the stator surface. By calculating the equivalent elastic coefficient c11 and lateral piezoelectric constant d31, the optimal crystal orientations were proposed for PMNT single crystals poled along different directions. For single crystal poled along c directions, the optimal orientation lies along [001]c with d31=-1335pC/N and k31=0.87. The crystallographic orientation [025]c is the optimized orientation for single crystals poled along c direction with d31=199pC/N and k31=0.55. The optimal orientation of 1R configuration is [332¯]c with a large enhancement of d31 = 1201 and k31=0.92.
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Graphene rings in magnetic fields: Aharonov–Bohm effect and valley splitting
International Nuclear Information System (INIS)
Wurm, J; Wimmer, M; Richter, K; Baranger, H U
2010-01-01
We study the conductance of mesoscopic graphene rings in the presence of a perpendicular magnetic field by means of numerical calculations based on a tight-binding model. First, we consider the magnetoconductance of such rings and observe the Aharonov–Bohm effect. We investigate different regimes of the magnetic flux up to the quantum Hall regime, where the Aharonov–Bohm oscillations are suppressed. Results for both clean (ballistic) and disordered (diffusive) rings are presented. Second, we study rings with smooth mass boundary that are weakly coupled to leads. We show that the valley degeneracy of the eigenstates in closed graphene rings can be lifted by a small magnetic flux, and that this lifting can be observed in the transport properties of the system
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Sugiyama, Takemi; Niyonsenga, Theo; Howard, Natasha J; Coffee, Neil T; Paquet, Catherine; Taylor, Anne W; Daniel, Mark
2016-12-01
Consistent associations have been observed between macro-level urban sprawl and overweight/obesity, but whether residential proximity to urban centres predicts adiposity change over time has not been established. Further, studies of local-area walkability and overweight/obesity have generated mixed results. This study examined 4-year change in adults' waist circumference in relation to proximity to city centre, proximity to closest suburban centre, and local-area walkability. Data were from adult participants (n=2080) of a cohort study on chronic conditions and health risk factors in Adelaide, Australia. Baseline data were collected in 2000-03 with a follow-up in 2005-06. Multilevel regression models examined in 2015 the independent and joint associations of the three environmental measures with change in waist circumference, accounting for socio-demographic covariates. On average, waist circumference rose by 1.8cm over approximately 4years. Greater distance to city centre was associated with a greater increase in waist circumference. Participants living in distal areas (20km or further from city centre) had a greater increase in waist circumference (mean increase: 2.4cm) compared to those in proximal areas (9km or less, mean increase: 1.2cm). Counterintuitively, living in the vicinity of a suburban centre was associated with a greater increase in adiposity. Local-area walkability was not significantly associated with the outcome. Residential proximity to city centre appears to be protective against excessive increases in waist circumference. Controlled development and targeted interventions in the urban fringe may be needed to tackle obesity. Additional research needs to assess behaviours that mediate relationships between sprawl and obesity. Copyright © 2016 Elsevier Inc. All rights reserved.
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Association of head circumference and shoulder dystocia in macrosomic neonates.
Larson, Austin; Mandelbaum, David E
2013-04-01
To determine whether asymmetric macrosomia (disproportionately large body size in comparison to head circumference) could be demonstrated in a population of infants suffering shoulder dystocia during delivery relative to those that did not suffer from shoulder dystocia. A case-control study was conducted as a retrospective chart review over 3 years at a large maternity hospital in an urban setting. Among infants over 4,000 g, those that suffered from shoulder dystocia during delivery had a smaller mean head circumference than infants of a similar size that did not suffer from shoulder dystocia. A statistically significant difference was also present when cases of documented gestational diabetes were excluded. Asymmetric macrosomia is more likely to be present in a population of infants who suffered shoulder dystocia during delivery. This knowledge could be used in designing tools to predict which pregnancies are at highest risk for shoulder dystocia during delivery.
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Reduction of ring artefacts in high resolution micro-CT reconstructions
International Nuclear Information System (INIS)
Sijbers, Jan; Postnov, Andrei
2004-01-01
High resolution micro-CT images are often corrupted by ring artefacts, prohibiting quantitative analysis and hampering post processing. Removing or at least significantly reducing such artefacts is indispensable. However, since micro-CT systems are pushed to the extremes in the quest for the ultimate spatial resolution, ring artefacts can hardly be avoided. Moreover, as opposed to clinical CT systems, conventional correction schemes such as flat-field correction do not lead to satisfactory results. Therefore, in this note a simple but efficient and fast post processing method is proposed that effectively reduces ring artefacts in reconstructed μ-CT images. (note)
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International Nuclear Information System (INIS)
Emparan, Roberto; Reall, Harvey S
2006-01-01
A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)
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Directory of Open Access Journals (Sweden)
Odewumi Adegbija
Full Text Available To predict in an Australian Aboriginal community, the 10-year absolute risk of type 2 diabetes associated with waist circumference and age on baseline examination.A sample of 803 diabetes-free adults (82.3% of the age-eligible population from baseline data of participants collected from 1992 to 1998 were followed-up for up to 20 years till 2012. The Cox-proportional hazard model was used to estimate the effects of waist circumference and other risk factors, including age, smoking and alcohol consumption status, of males and females on prediction of type 2 diabetes, identified through subsequent hospitalisation data during the follow-up period. The Weibull regression model was used to calculate the absolute risk estimates of type 2 diabetes with waist circumference and age as predictors.Of 803 participants, 110 were recorded as having developed type 2 diabetes, in subsequent hospitalizations over a follow-up of 12633.4 person-years. Waist circumference was strongly associated with subsequent diagnosis of type 2 diabetes with P<0.0001 for both genders and remained statistically significant after adjusting for confounding factors. Hazard ratios of type 2 diabetes associated with 1 standard deviation increase in waist circumference were 1.7 (95%CI 1.3 to 2.2 for males and 2.1 (95%CI 1.7 to 2.6 for females. At 45 years of age with baseline waist circumference of 100 cm, a male had an absolute diabetic risk of 10.9%, while a female had a 14.3% risk of the disease.The constructed model predicts the 10-year absolute diabetes risk in an Aboriginal Australian community. It is simple and easily understood and will help identify individuals at risk of diabetes in relation to waist circumference values. Our findings on the relationship between waist circumference and diabetes on gender will be useful for clinical consultation, public health education and establishing WC cut-off points for Aboriginal Australians.
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Measurement of surface-induced microplasticity in Alloy 600 C-rings
International Nuclear Information System (INIS)
Lo, C.F.; Kamide, H.; Mayo, W.E.; Weissmann, S.
1990-03-01
The level of microplasticity in Alloy 600 specimens used for accelerated SCC tests was measured with the aid of a novel x-ray rocking curve technique developed at Rutgers University. With this tool, it was possible to measure quantitatively the strain level at any point along the circumference of a C-ring. Combined with selective etching, the method was used to obtain a depth profile of the strain. A detailed study of the deformation state in C-rings was performed with a particular emphasis on how material parameters influence localization of the strain. These studies included the role of grain boundary carbides, grain size and mill anneal temperatures. The studies led to the development of a numerical model for calculation of the strain distribution along a C-ring which is superior to that currently in use. An additional result of these studies was a simple indirect method that can be used to determine the amount of grain boundary carbides present in tubes of Alloy 600. The final phase of this project was to measure the strain relaxation kinetics in this alloy. From this work, the activation energy for relaxation and the atomistic process responsible were identified. Based on this work, calculations were performed to indicate the degree of relaxation that can be expected during normal steam generator operation and accelerated SCC testing. These calculations suggest that relaxation may be significant in the temperature range of 280--360 degree C which is typical for such tests and highlights the fact that during these tests significant changes in the microstructure that can be detected by x-rays are taking place. These results will provide a more accurate basis for extrapolating tests to actual steam generator corrosion experience. 6 figs., 2 tabs
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Variations in Ring Particle Cooling across Saturn's Rings with Cassini CIRS
Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Déau, E.; Altobelli, N.
2010-12-01
Cassini's Composite Infrared Spectrometer has recorded over two million of spectra of Saturn's rings in the far infrared since arriving at Saturn in 2004. CIRS records far infrared radiation between 10 and 600 cm-1 ( 16.7 and 1000 μ {m} ) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn’s rings peaks in this wavelength range. Ring temperatures can be inferred from FP1 data. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and rapidly changing temperatures are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid particles can be expected to have higher thermal inertias. Ferrari et al. (2005) fit thermal inertia values of 5218 {Jm)-2 {K}-1 {s}-1/2 to their B ring data and 6412 {Jm)-2 {K}-1 {s}-1/2 to their C ring data. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The rings’ thermal budget is dominated by its absorption of solar radiation. As a result, ring particles abruptly cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.
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Heat transfer behaviors in round tube with conical ring inserts
International Nuclear Information System (INIS)
Promvonge, P.
2008-01-01
To increase convection heat transfer in a uniform heat flux tube by a passive method, several conical rings used as turbulators are mounted over the test tube. The effects of the conical ring turbulator inserts on the heat transfer rate and friction factor are experimentally investigated in the present work. Conical rings with three different diameter ratios of the ring to tube diameter (d/D = 0.5, 0.6, 0.7) are introduced in the tests, and for each ratio, the rings are placed with three different arrangements (converging conical ring, referred to as CR array, diverging conical ring, DR array and converging-diverging conical ring, CDR array). In the experiment, cold air at ambient condition for Reynolds numbers in a range of 6000-26,000 is passed through the uniform heat flux circular tube. It is found that the ring to tube diameter ratio and the ring arrays provide a significant effect on the thermal performance of the test tube. The experimental results demonstrate that the use of conical ring inserts leads to a higher heat transfer rate than that of the plain surface tube, and the DR array yields a better heat transfer than the others. The results are also correlated in the form of Nusselt number as a function of Reynolds number, Prandtl number and diameter ratio. An augmentation of up to 197%, 333%, and 237% in Nusselt number is obtained in the turbulent flow for the CR, DR and CDR arrays, respectively, although the effect of using the conical ring causes a substantial increase in friction factor
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Measurement of scrotal circumference in beef bulls in Rio Grande do Sul
Directory of Open Access Journals (Sweden)
S.R.O Menegassi
2011-02-01
Full Text Available The variability of scrotal circumference and the effects of age and breed as well as the relationship between testicular weight (TW, scrotal circumference (SC, and live weight (BW were investigated in bulls. Devon, Polled Hereford, and Red Angus breeds showed higher SC values than the other British, Continental, Synthetic, and Zebu studied breeds. The percentage of culled bulls because of low SC ranged from 7.01 to 24.25%. The increase of SC was proportional to the increase in TW and they were highly correlated (r²= 0.90. The results suggest that SC in young bulls is the best way to predict TW and, therefore, a useful tool for their selection
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Goodaire, EG; Polcino Milies, C
1996-01-01
For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri
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Primitivity and weak distributivity in near rings and matrix near rings
International Nuclear Information System (INIS)
Abbasi, S.J.
1993-08-01
This paper shows the structure of matrix near ring constructed over a weakly distributive and primative near ring. It is proved that a weakly distributive primitive near ring is a ring and the matrix near rings constructed over it is also a bag. (author). 14 refs
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Electron cooling of PB$^{54+}$ ions in the low energy ion ring (LEIR)
Bosser, Jacques; Chanel, M; MacCaferri, R; Maury, S; Möhl, D; Molinari, G; Tranquille, G
1998-01-01
For the preparation of dense bunches of lead ions for the LHC, electron cooling will be essential for accumula tion in a storage ring at 4.2 MeV/u. Tests have been carried out on the LEAR ring (renamed LEIR for Low Energy Ion Ring) in order to determine the optimum parameters for a future state-of-the-art electron cooling device which would be able to cool linac pulses of lead ions in less than 100 ms. The experiments focused on the generation of a stable high intensity electron beam that is needed to free space in both longitudinal and transverse phase space for incoming pulses. Investigations on the ion beam lifetime in the presence of the electron beam and on the dependency of the cooling times on the optical settings of the storage ring will also be discussed. This paper concentrates on the cooling aspects with the multiturn injection, vacuum, and high intensity aspects discussed in a companion paper at this conference.
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Positron emission tomography camera
International Nuclear Information System (INIS)
Anon.
1986-01-01
A positron emission tomography camera having a plurality of detector rings positioned side-by-side or offset by one-half of the detector cross section around a patient area to detect radiation therefrom. Each ring contains a plurality of scintillation detectors which are positioned around an inner circumference with a septum ring extending inwardly from the inner circumference along each outer edge of each ring. An additional septum ring is positioned in the middle of each ring of detectors and parallel to the other septa rings, whereby the inward extent of all the septa rings may be reduced by one-half and the number of detectors required in each ring is reduced. The additional septa reduces the costs of the positron camera and improves its performance
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Overview of collective effects in the NLC main damping rings
International Nuclear Information System (INIS)
Wolski, A.; Santis, S. de
2002-01-01
The present design for the NLC Main Damping Rings (MDRs) meets the specifications for acceptance and extracted emittance, in the limit of zero current. However, the relatively large bunch charge and moderate energy mean that a variety of collective effects can impact the beam dynamics, leading to loss of stability or increase of equilibrium emittance. These effects include intrabeam scattering, impedance from numerous sources, fast ion instability, and (in the positron ring) electron cloud. In this note, we survey the expected impact on damping ring performance from each of a number of collective effects, and discuss the priorities for future studies in this area
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Interaction of ring dark solitons with ring impurities in Bose-Einstein condensates
International Nuclear Information System (INIS)
Xue Jukui
2005-01-01
The interaction of ring dark solitons/vortexes with the ring-shaped repulsive and attractive impurities in two-dimensional Bose-Einstein condensates is investigated numerically. Very rich interaction phenomena are obtained, i.e., not only the interaction between the ring soliton and the impurity, but also the interaction between vortexes and the impurity. The interaction characters, i.e., snaking of ring soliton, quasitrapping or reflection of ring soliton and vortexes by the impurity, strongly depend on initial ring soliton velocity, impurity strength, initial position of ring soliton and impurity. The numerical results also reveal that ring dark solitons/vortexes can be trapped and dragged by an adiabatically moving attractive ring impurity
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The link between BMI and waist circumference in northern Iranian ...
African Journals Online (AJOL)
Background and Objectives: Waist circumference and not body mass index explains a greater variance in obesity-related health risk. The present study assesses the link between BMI and WC in Iranian adults. Methods: In a population based cross- sectional study on 3600 adults, northern Iran, we investigated the link ...
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Directory of Open Access Journals (Sweden)
Razieh Karimbeiki
2016-11-01
Full Text Available Context Milk and dairy products consumed by mothers seem to be effective for fetal and neonatal anthropometric measurements, because they contain various nutrients. Objectives The aim of this study was to systematically review the influence of milk and dairy products consumption by mothers on fetal and neonatal head circumferences. Data Sources Systematic searches were conducted in electronic databases including PubMed/MEDLINE, Scopus, ISI, Ovid, Embase, Medlib, Google Scholar, clinical trials and Cochrane central register of clinical trials. Study Selection All studies that assessed the relationship between milk and dairy products consumption in healthy females during pregnancy and fetal and neonatal head circumferences were included in our systematic review. Finally, seven studies were relevant that included five cohort studies, one cross-sectional study and one randomized clinical trial. Data Extraction This systematic review was performed based on the preferred reporting item for systematic reviews and meta-analysis (PRISMA statement recommendation, and for quality assessment, the Newcastle-Ottawa scale (NOS for cohort studies, the adapted NOS for a cross-sectional study and the Jadad quality assessment score for a randomized clinical trial, were used. Results Seven studies that comprised of more than 50000 pregnant females were included in this review. One cohort study, one cross-sectional study and one randomized controlled trial study showed that milk or dairy products consumption by pregnant mothers was not associated with neonatal birth head circumference, while three cohort studies reported that maternal milk or dairy products intake had a positive effect on neonatal birth head circumference. Two cohort studies showed that there was no relationship between maternal milk or dairy products consumption and fetal head circumference while a cross-sectional study reported that there was a positive relationship between milk or dairy products
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Bollini, C G; Giambiagi, M
2001-01-01
Through the graphical method proposed it is possible to set a link between an MO multicenter bond index and VB structures. The value of the index depends on the order of the atoms involved if they are more than three. For 5-c rings three basic structures are required; the eventually different values are 12. Unlike the 6-c case it may happen that different pairs of basic structures are used to build the same polygon. For the 6-c rings including heteroatoms the original degeneracy of benzene splits leading eventually to 60 different I sub r sub i sub n sub g values.
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Hip circumference and cardiovascular morbidity and mortality in men and women
DEFF Research Database (Denmark)
Heitmann, Berit L; Frederiksen, Peder; Lissner, Lauren
2004-01-01
to 1988) participated in the Danish MONICA (MONItoring trends and determinants of CArdiovascular disease) project, with measurements of height, weight, and hip and waist circumference taken. Through personal identification numbers, incidence of coronary heart disease (CHD) and cardiovascular disease (CVD...
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Impacts of aerosol lead to natural ecosystems
International Nuclear Information System (INIS)
Murozumi, Masayo; Nakamura, Seiji; Yoshida, Katsumi
1982-01-01
Impacts of aerosol lead have changed the concentration and isotopic ratios of the element circulating in remote ecosystems in the Hidaka and Tarumae mountains. Concentrations of lead in successive each 10 years ring veneer of Cercidiphyllum Japonica show that amount of the element residing on the bark and supwood layers has increased by a factor of 2 or more in comparison with that of the core part. The isotopic ratios of lead in the basement rocks and soils under the ecosystems converge to a certain narrow spot along the isochron Iine of the element, and distinguish their geochronogical characteristics from other leads of different sources. In these ecosystems, however, the lead isotopic ratios of materials exposed to the atmosphere are similar to those of foreign and anthropogenic aerosol lead but are evidently dissimilar to those of the rocks and soils. Furthermore, the lead isotopic ratios in yearly ring veneers of Ceridiphyllum Japonica and Ostrya Japonica show a certain differentiation towards the bark from the core, i.e., an approach to those of anthropogenic aerosol lead from those of the basement rocks and soils, as listed in Table 7. The lead burden per hectare in these remote ecosystems has increased to 4 g by the impact of 2 g of aerosol lead. (author)
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Oliveras Puig, A; Dalfó-Pibernat, A; Jdid Rosàs, N; Mayor Isaac, E; Pérez-Romero, L; Gibert Llorach, E; Dalfó-Baqué, A
2015-01-01
To assess the effectiveness of an intervention to promote standardized arm circumference measurement as way to choose appropriate cuff size to measure blood pressure. A before-after intervention study was performed in a basic health care area in Barcelona. Doctors, nurses and pharmacy staff participated by filling out an anonymous self-administered questionnaire pre- and post-intervention (3m). Variables included: demographics, type of professional, years since they finished their studies, availability of different cuff sizes, if arm circumference measurement were obtained or not, knowledge about the cutoff values for each cuff size and type of blood pressure monitor. The written results were given to the participants and presented in sessions. Pre- and post-intervention: 74.3 and 67.3% answered the questionnaires (P=ns), respectively. Determination of arm circumference varied from 1.3 to 19.1% (P=.009). A total of 37.3% and 44.1% declared that they had 2 or more available cuff sizes (P=ns). Knowledge about the correct measurement of the cuffs was 2.7 to 33.8% regarding the standard cuff size (P=.0198) and 0 to 23.5% for obese subjects (P<.05). When more than one cuff was available, reasons for the choice went from: «making a rough guess» or «when velcro stops sticking» before and after the intervention. All blood pressure devices in our primary health care center were electronic and automatic as were those of the 9 pharmacies. The intervention increased the determination of arm circumference prior to the reading of the blood pressure and the knowledge about the cutoff interval for standard and obese cuff size after intervention. There was greater availability of different sized cuffs. Despite this, the choice of the appropriate cuff size was not made based on arm circumference. Copyright © 2014 SEHLELHA. Published by Elsevier Espana. All rights reserved.
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Erect penile length and circumference dimensions of 1,661 sexually active men in the United States.
Herbenick, Debby; Reece, Michael; Schick, Vanessa; Sanders, Stephanie A
2014-01-01
Penile size continues to receive popular and empirical attention. Little is known about the process of self-measurement and whether the behaviors a man engages in to become erect for self-measurement are associated with his erect penile dimensions. The article aims to assess men's erect penile dimensions in a study in which the men would presumably be motivated to report accurate information about their penis size; and to explore associations between men's erect penile dimensions, their method of measurement, and their demographics. Data are from an Internet-based baseline phase of a large prospective daily diary study that compared men's use of a standard-sized condom to men's use of a condom sized to fit their erect penis. The main outcomes are participant characteristics, activities engaged in during self-measurement process, and self-reported erect penile length and circumference. For this sample of 1,661 men, the mean erect penile length was 14.15 cm (SD = 2.66; range = 4 to 26 cm), and the mean erect penile circumference was 12.23 cm (SD = 2.23; range = 3 to 19). Participant characteristics were not associated with measured length or circumference. Most men measured their penis while alone, using hand stimulation to become erect. In this sample of men who measured their erect penile length and circumference for the purposes of receiving a condom sized to fit their erect penis, we found a mean erect penile length of 14.15 cm and a mean erect penile circumference of 12.23 cm. The self-reported erect penile dimensions in this study are consistent with other penile dimension research. Also, findings suggest that mode of getting an erection may influence erect penile dimensions. Additionally, how a man becomes erect for self-measurement may be associated with his erect penile length and/or circumference. © 2013 International Society for Sexual Medicine.
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Piston ring lubrication and hydrocarbon emissions from internal combustion engines
Energy Technology Data Exchange (ETDEWEB)
Froelund, K.
1997-11-01
Is it the intention with this project to improve the existing hydrocarbon emission model at the Institute by combining it with a model for predicting the piston ring lubrication. The piston ring lubrication model should be experimentally verified to ensure the validity of the model. The following items were the objectives of the current study: Develop a piston ring lubrication model. This implies the development of a ring-pack gas flow model; Examine the response of the piston ring lubrication model to changing engineer conditions. Especially, it would be interesting to look at the engine warm-up phase since this is the phase where the engine-out emissions are highest and where the commonly used three way catalyst is not capable of converting the engine-out emissions, thereby leading the engine-out emissions directly out in to the environment with the exhaust gases; In order to verify the piston ring lubrication model the lubricant distribution on the cylinder liner should be investigated experimentally. Here again it would be of great interesting to look at the engine warm-up phase; The piston ring lubrication model should be adjusted for application together with the new hydrocarbon emission model for SI-engines at the Institute in order to increase the accuracy of the latter; The piston ring lubrication model could be used for describing the transport of PAH`s in diesel engines. (EG)
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Wolski, Andrzej
2014-01-01
The effects of synchrotron radiation on particle motion in storage rings are discussed. In the absence of radiation, particle motion is symplectic, and the beam emittances are conserved. The inclusion of radiation effects in a classical approximation leads to emittance damping: expressions for the damping times are derived. Then, it is shown that quantum radiation effects lead to excitation of the beam emittances. General expressions for the equilibrium longitudinal and horizontal (natural) emittances are derived. The impact of lattice design on the natural emittance is discussed, with particular attention to the special cases of FODO-, achromat- and theoretical-minimum-emittance-style lattices. Finally, the effects of betatron coupling and vertical dispersion (generated by magnet alignment and lattice tuning errors) on the vertical emittance are considered.
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International Nuclear Information System (INIS)
Wu Suzhi; Li Ning; Jin Guojun; Ma Yuqiang
2008-01-01
Persistent current and transmission probability in the Aharonov-Bohm (AB) ring with an embedded quantum dot (QD) are studied using the technique of the scattering matrix. For the first time, we find that the persistent current can arise in the absence of magnetic flux in the ring with an embedded QD. The persistent current and the transmission probability are sensitive to the lead-ring coupling and the short-range potential barrier. It is shown that increasing the lead-ring coupling or the short-range potential barrier causes the suppression of the persistent current and the increasing resonance width of the transmission probability. The effect of the potential barrier on the number of the transmission peaks is also investigated. The dependence of the persistent current and the transmission probability on the magnetic flux exhibits a periodic property with period of the flux quantum
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The behavior of the planetary rings under the Kozai Mechanism
Sucerquia, M. A.; Ramírez, C. V.; Zuluaga, J. I.
2017-07-01
Rings are one of the main feature of almost all giant planets in the Solar System. Even though thousands of exoplanets have been discovered to date, no evidence of exoplanetary rings have been found despite the effort made in the development and enhancing of techniques and methods for direct or indirect detection. In the transit of a ringed planet, the dynamic of the ring itself could play a meaningful role due to the so called Kozai Mechanism (KM) acting on each particle of it. When some specific initial conditions of the ring are fulfilled (as a ring inclination greater than ˜ 39°), KM generates short periodic changes in the inclination and eccentricity of each particle, leading to a meaningful characteristic collective behavior of the ring: it changes its width, inclination and optical depth. These changes induce periodic variations on the eclipsed area of the parent star, generating slight changes in the observed transit signal. Under this mechanism, light curves depths and shapes oscillate according to the fluctuations of the ring. To show this effect we have performed numerical simulations of the dynamic of a system of particles to asses the ring inclination and width variations over time. We have calculated the expected variations in the transit depth and finally, we have estimated the effect on the light curve of a hypothetical ringed exoplanet affected by the KM. The detection of this effect could be used as an alternative method to detect/confirm exoplanetary rings, and also it could be considered as a way to explain anomalous light curves patterns of exoplanets, as the case of KIC 8462852 star.
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Neck Circumference as a Predictor of Adiposity among Healthy and Obese Children
Directory of Open Access Journals (Sweden)
Nayera E. Hassan
2015-11-01
Full Text Available BACKGROUND: Obesity, particularly in the upper part of body, is a major health problem. Because body mass index (BMI does not adequately describe regional adiposity, other indices of body fatness are being explored. OBJECTIVES: To determine if neck circumference is a valid measure of adiposity (fat distribution among group of Egyptian children. SUBJECTS AND METHODS: This is a cross sectional study, included 50 obese subjects, aged 7 - 12 years recruited from Endocrine, obesity and Metabolism Pediatric Unit at Children Hospital, Cairo University and 50 healthy children, age and sex matched. All children were subjected to blood pressure assessment (systolic SBP and diastolic DBP, and anthropometric assessment (body weight, height, neck circumference (NC, waist (WC and hip (HC circumferences, and skin fold thicknesses at three sites: biceps, triceps and sub scapular. BMI [weight (kg/height (m2] was calculated. RESULTS: In healthy females, significant associations were detected between NC and SBP, DBP and all anthropometric measurements. However, in healthy males NC was not significantly associated with BMI, SBP and DBP. In the obese group; both sexes; insignificant association was found between NC and SBP, DBP, BMI and skinfold thickness. CONCLUSION: NC is related to fat distribution among normal healthy female children. However, this relation disappears with increasing adiposity. The results do not support the use of NC as a useful screening tool for childhood obesity.
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Experimental Observation of Fermi-Pasta-Ulam Recurrence in a Nonlinear Feedback Ring System
Wu, Mingzhong; Patton, Carl E.
2007-01-01
Fermi-Pasta-Ulam recurrence through soliton dynamics has been realized. The experiment used a magnetic film strip-based active feedback ring. At some ring gain level, a wide spin wave pulse is self-generated in the ring. As the pulse circulates, it separates into two envelop solitons with different speeds. When the fast soliton catches up and collides with the slow soliton, the initial wide pulse is perfectly reconstructed. The repetition of this process leads to periodic recurrences of the initial pulse.
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Afshar, Hossein; Ghandehari, Mehdi; Soleimani, Banafsheh
2015-12-01
It is not clear what type of pre-crimped crown is more successful in achieving greater marginal adaptation following re-crimping. This study aimed to assess the changes in the circumference of 3M ESPE and MIB pre-crimped stainless steel crowns (SSCs) for the primary maxillary and mandibular first and second molars following re-crimping. This was an in-vitro, experimental study. Initial photographs were obtained from the margins of 3M and MIB SSCs for the upper and lower primary molars using a digital camera. Crown margins were crimped by applying 0.2N force using 114 and 137 pliers. Post-crimping photographs were also obtained and the changes in crown circumference after crimping were calculated using AutoCad software. The percentage of reduction in the circumference of crowns for each tooth was statistically analyzed based on the type of crown using student t-test. The effect of crown design and the associated teeth on the decreased circumference percentage was statistically analyzed by two-sided ANOVA. The percentage of reduction in lower E SSC circumference was 3.71±0.39% in MIB and 6.29±0.62% in 3M crowns. These values were 3.55±0.55% and 7.15±1.13% for the lower Ds, and 3.95±0.43 and 6.24±0.85% for the upper Ds, respectively. For the upper Es, these values were found to be 3.12±0.65% and 5.14±0.94%, respectively. For each tooth, a significant difference was found between MIB and 3M SSCs in terms of the percentage of reduction in crown circumference following crimping. The magnitude of this reduction was smaller in MIB compared to 3M SSCs (P<0.001). Considering the significant reduction in the marginal circumference of precrimped SSCs following re-crimping, it appears that this manipulation must be necessarily performed for MIB and 3M pre-crimped SSCs. By using 3M SSCs, higher marginal adaptation can be achieved following crimping.
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Energy Technology Data Exchange (ETDEWEB)
Lu, Chenying; Wang, Zufei; Ji, Jiansong; Wang, Hailin; Hu, Xianghua; Chen, Chunmiao [Department of Radiology, Lishui Central Hospital, The Fifth Affiliated Hospital of Wenzhou Medical College, Lishui, Zhejiang 323000 (China)
2015-11-01
To assess the effect of chest circumference-adapted scanning protocol on radiation exposure and image quality in patients undergoing prospective electrocardiogram (ECG)-triggered coronary CT angiography (CCTA). One hundred-eighty-five consecutive patients, who had undergone prospective ECG triggering CCTA with a 128-slice CT, were included in the present study. Nipple-level chest circumference, body weight and height were measured before CT examinations. Patients were divided into four groups based on kV/ref·mAs = 100/200, 100/250, 120/200, and 120/250, when patient's chest circumference was ≤ 85.0 (n = 56), 85.0-90.0 (n = 53), 90.0-95.0 (n = 44), and > 95.0 (n = 32), respectively. Image quality per-segment was independently assessed by two experienced observers. Image noise and attenuation were also measured. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The effective radiation dose was calculated using CT dose volume index and the dose-length product. A significant correlation was observed between patients' chest circumference and body mass index (r = 0.762, p < 0.001). Chest circumference ranged from 74 to 105 cm, and the mean effective radiation dose was 1.9-3.8 mSv. Diagnostic image quality was obtained in 98.5% (2440/2478) of all evaluated coronary segments without any significant differences among the four groups (p = 0.650). No significant difference in image noise was observed among the four groups (p = 0.439), thus supporting the validity of the chest circumference-adapted scanning protocol. However, vessel attenuation, SNR and CNR were significantly higher in the 100 kV groups than in the 120 kV groups (p < 0.05). A measure of chest circumference can be used to adapt tube voltage and current for individualized radiation dose control, with resultant similar image noise and sustained diagnostic image quality.
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Association of Neck Circumference with Obesity in Female College Students.
Papandreou, Dimitrios; Noor, Zujaja Tul; Rashed, Maitha; Jaberi, Hadeel Al
2015-12-15
Obesity levels have been dramatically increased in the United Arab Emirates over the last few years. High levels of body Mass Index, waist circumference, and percent of total body fat as a measure of obesity have found to be related to cardiovascular risk factors and other diseases. Neck circumference is a new tool that has been linked to obesity. However, no studies in UAE have been conducted yet. The purpose of this study was to measure the obesity levels in a college population and to correlate them with NC and other anthropometrical indexes. Two hundred forty three (243) female students aged 18-25 were conveniently selected to participate in the study. Anthropometrical indexes were obtained from all subjects e after fasting. The prevalence of overweight and obesity together was found to be 28.4 % (n = 69). Pearson correlation showed that WC, NC and BF (%) were significantly positively related to obesity, (r = 0.790; r = 0.758; r = 0.767, p obesity. NC was found to be independently associated with obesity levels in Emirati college students.
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Fonseca-Reyes, Salvador; de Alba-García, Javier García; Parra-Carrillo, José Z; Paczka-Zapata, José Antonio
2003-06-01
To measure the effect on blood pressure readings when a standard cuff is used on patients with arms of a large circumference, and to determine the frequency of arms of a large circumference. Blood pressures were taken in 120 subjects with an arm circumference greater than 33 cm. Also, the arm circumference was determined in 244 patients from a family health unit, and in 216 patients from a hypertension clinic. A mercury sphygmomanometer and two different cuff sizes were used in a random sequence; therefore, 60 patients' blood pressure were first measured with a large cuff, followed by a standard cuff; the opposite sequence was then applied for another 60 patients. With the obtained values and using a regression analysis, the difference in blood pressure overestimation was calculated. Arm circumference measurement percentages were used to determine the frequency of arms of a large circumference. Both systolic and diastolic blood pressures were significantly greater when the standard cuff was used. For every 5 cm increase in arm circumference, starting at 35 cm, a 2-5 mmHg increase in systolic blood pressure, and a 1-3 mmHg increase in diastolic blood pressure was observed. The prevalence of arms with a large circumference in the family medicine unit and hypertension clinic was 42% and 41.8%, respectively. There is an overestimation of blood pressure when a standard cuff is used in obese subjects. The high prevalence of these individuals in our environment, both in the hypertensive and normotensive population, makes it necessary to have on hand different sizes of cuffs for taking blood pressure in order to avoid incorrect decisions.
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Large quantum rings in the ν > 1 quantum Hall regime
International Nuclear Information System (INIS)
Raesaenen, E; Aichinger, M
2009-01-01
We study computationally the ground-state properties of large quantum rings in the filling-factor ν>1 quantum Hall regime. We show that the arrangement of electrons into different Landau levels leads to clear signatures in the total energies as a function of the magnetic field. In this context, we discuss possible approximations for the filling factor ν in the system. We are able to characterize integer-ν states in quantum rings in an analogy with conventional quantum Hall droplets. We also find a partially spin-polarized state between ν = 2 and 3. Despite the specific topology of a quantum ring, this state is strikingly reminiscent of the recently found ν = 5/2 state in a quantum dot.
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Large quantum rings in the ν > 1 quantum Hall regime.
Räsänen, E; Aichinger, M
2009-01-14
We study computationally the ground-state properties of large quantum rings in the filling-factor ν>1 quantum Hall regime. We show that the arrangement of electrons into different Landau levels leads to clear signatures in the total energies as a function of the magnetic field. In this context, we discuss possible approximations for the filling factor ν in the system. We are able to characterize integer-ν states in quantum rings in an analogy with conventional quantum Hall droplets. We also find a partially spin-polarized state between ν = 2 and 3. Despite the specific topology of a quantum ring, this state is strikingly reminiscent of the recently found ν = 5/2 state in a quantum dot.
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Possibility of persistent voltage observation in a system of asymmetric superconducting rings
International Nuclear Information System (INIS)
Burlakov, A.A.; Gurtovoi, V.L.; Ilin, A.I.; Nikulov, A.V.; Tulin, V.A.
2012-01-01
The possibility of observing persistent voltage in superconducting rings of different arm widths is experimentally investigated. It was previously found that switching of the arms between superconducting and normal states by an AC current induces DC voltage oscillation in the magnetic field with a period corresponding to the flux quantum inside the ring. We used systems with a large number of asymmetric rings connected in series to investigate the possibility of observing this quantum phenomenon near the superconducting transition, where thermal fluctuations lead to switching of ring segments without an external influence and the persistent current is much smaller than in the superconducting state. -- Highlights: ► A possibility to observe the persistent voltage is investigated experimentally. ► The persistent voltage is a DC voltage observed at thermodynamic equilibrium. ► It oscillates in magnetic field like the persistent current in superconducting ring. ► The period of the oscillations corresponds to the flux quantum inside the ring. ► The quantum oscillations of the DC voltage were observed on asymmetric rings.
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Modi, Payal; Nasrin, Sabiha; Hawes, Meagan; Glavis-Bloom, Justin; Alam, Nur H; Hossain, M Iqbal; Levine, Adam C
2015-07-01
Undernutrition contributes to 45% of all deaths in children children with diarrhea and possible dehydration. This study assessed the validity of different measures of undernutrition in children with diarrhea. A prospective cohort study was conducted at an urban hospital in Bangladesh. Children children for screening, of which 1025 were eligible, 850 were enrolled, and 721 had complete data for analysis. Anthropometric measurements, including weight-for-age z score (WAZ), weight-for-length z score (WLZ), midupper arm circumference (MUAC), and midupper arm circumference z score (MUACZ), were calculated pre- and posthydration in all patients. Measurements were evaluated for their ability to correctly identify undernutrition in children with varying degrees of dehydration. Of the 721 patients with full data for analysis, the median percent dehydration was 4%. Of the 4 measures evaluated, MUAC and MUACZ demonstrated 92-94% agreement pre- and posthydration compared with 69-76% for WAZ and WLZ. Although each 1% change in hydration status was found to change weight-for-age by 0.0895 z scores and weight-for-length by 0.1304 z scores, MUAC and MUACZ were not significantly affected by dehydration status. Weight-based measures misclassified 12% of children with severe underweight and 14% with severe acute malnutrition (SAM) compared with only 1-2% for MUAC and MUACZ. MUAC and MUACZ were the most accurate predictors of undernutrition in children with diarrhea. WAZ and WLZ were significantly affected by dehydration status, leading to the misdiagnosis of many patients on arrival with severe underweight and SAM. This trial was registered at clinicaltrials.gov as NCT02007733. © 2015 American Society for Nutrition.
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Circumference estimation using 3D-whole body scanners and shadow scanner
Daanen, H.A.M.
1998-01-01
Clothing designers and manufacturers use traditional body dimensions as their basis. When 3D-whole body scanners are introduced to determine the body dimensions, a conversion has to be made, since scan determined circumference measures are slightly larger than the traditional values. This pilot
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Relationship Between Neck Circumference and Epicardial Fat Thickness in a Healthy Male Population.
Küçük, Uğur; Küçük, Hilal Olgun; Cüce, Ferhat; Balta, Sevket
2016-09-01
Epicardial fat is an upper body visceral fat depot that may play a significant role in the development of adverse metabolic and cardiovascular risk profiles. There is a significant direct relationship between the amount of epicardial fat and general body adiposity (body mass index, BMI), but data regarding subcutaneous adiposity is limited. We conducted a study to determine the association between neck circumference and epicardial fat thickness in healthy young male individuals, and assess their individual correlations with general body adiposity and cardiometabolic risk factors. One hundred consecutive male patients aged 18 years or older with no known major medical conditions were included in the study. All participants underwent detailed physical examination including measurement of blood pressure, weight, height, waist/hip ratio, and neck circumference. Blood was collected to determine fasting glucose and lipid parameters. A standard echocardiographic examination was performed with additional epicardial fat thickness determination. Among 100 study participants, neck circumference correlated significantly with weight, waist circumference, BMI, blood glucose, serum total cholesterol, low-density (LDL)-cholesterol, and triglycerides levels. No significant correlation was found between neck circumference and high-density lipoprotein (HDL)-cholesterol levels. Neck circumference correlated moderately and positively with echocardiographic epicardial fat thickness. Among patients with low cardiometabolic risk, increased neck circumference was associated with increased epicardial fat thickness. A gordura epicárdica é um depósito de gordura visceral na parte superior do organismo que pode desempenhar um papel importante no desenvolvimento de perfis cardiovasculares e metabólicos adversos. Há uma relação direta significativa entre a quantidade de gordura epicárdica e a adiposidade corporal geral (índice de massa corporal, IMC), mas dados sobre a adiposidade
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Suppression of coffee ring: (Particle) size matters
Bansal, Lalit; Seth, Pranjal; Murugappan, Bhubesh; Basu, Saptarshi
2018-05-01
Coffee ring patterns in drying sessile droplets are undesirable in various practical applications. Here, we experimentally demonstrate that on hydrophobic substrates, the coffee ring can be suppressed just by increasing the particle diameter. Particles with larger size flocculate within the evaporation timescale, leading to a significant gravimetric settling (for Pe > 1) triggering a uniform deposit. Interestingly, the transition to a uniform deposit is found to be independent of the internal flow field and substrate properties. Flocculation of particles also alters the particle packing at the nanoscale resulting in order to disorder transitions. In this letter, we exhibit a physical exposition on how particle size affects morphodynamics of the droplet drying at macro-nano length scales.
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Optical control of spin-dependent thermal transport in a quantum ring
Abdullah, Nzar Rauf
2018-05-01
We report on calculation of spin-dependent thermal transport through a quantum ring with the Rashba spin-orbit interaction. The quantum ring is connected to two electron reservoirs with different temperatures. Tuning the Rashba coupling constant, degenerate energy states are formed leading to a suppression of the heat and thermoelectric currents. In addition, the quantum ring is coupled to a photon cavity with a single photon mode and linearly polarized photon field. In a resonance regime, when the photon energy is approximately equal to the energy spacing between two lowest degenerate states of the ring, the polarized photon field can significantly control the heat and thermoelectric currents in the system. The roles of the number of photon initially in the cavity, and electron-photon coupling strength on spin-dependent heat and thermoelectric currents are presented.
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Evolution of the ring current during two geomagnetic storms
International Nuclear Information System (INIS)
Lui, A.T.Y.; McEntire, R.W.; Krimigis, S.M.
1987-01-01
The progressive developments in the radial profiles of the particle pressure, plasma beta, and electric currents of the storm time ring current are investigated with data from the medium energy particle analyzer on the AMPTE Charged Particle Explorer spacecraft. Measurements of ions from 25 keV to 1 MeV, which carry 70--85% of the energy density of the entire ring current population, are used in this work. Two geomagnetic storms in September of 1984 are selected and four traversals of the equatorial ring current region during the course of each storm are studied. It is shown that enhancements in the particle pressure occur initially in the outer region and reach the inner region in the late phase of the storm. Structures suggestive of multiple particle injections are seen in the pressure profile. The leading and trailing edges of the particle injection structures are associated, respectively, with the depressions and enhancements of the westward current densities of the ring current. Plasma beta occasionally increases to values of the order of 1 in some regions of the ring current from prestorm values of the order of 0.1 or less. It is also found that the location of the maximum ring current particle pressure can be several earth radii from where the most intense westward ring current flows. This is a consequence of the dominance of pressure gradient current over the current associated with the magnetic field line curvature and particle anisotropy. copyright American Geophysical Union 1987
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Directory of Open Access Journals (Sweden)
Huaidong Du
Full Text Available BACKGROUND: Experimental studies show that a reduction in dietary energy density (ED is associated with reduced energy intake and body weight. However, few observational studies have investigated the role of ED on long-term weight and waist circumference change. METHODS AND PRINCIPAL FINDINGS: This population-based prospective cohort study included 89,432 participants from five European countries with mean age 53 years (range: 20-78 years at baseline and were followed for an average of 6.5 years (range: 1.9-12.5 years. Participants were free of cancer, cardiovascular diseases and diabetes at baseline. ED was calculated as the energy intake (kcal from foods divided by the weight (g of foods. Multiple linear regression analyses were performed to investigate the associations of ED with annual weight and waist circumference change. Mean ED was 1.7 kcal/g and differed across study centers. After adjusting for baseline anthropometrics, demographic and lifestyle factors, follow-up duration and energy from beverages, ED was not associated with weight change, but significantly associated with waist circumference change overall. For 1 kcal/g ED, the annual weight change was -42 g/year [95% confidence interval (CI: -112, 28] and annual waist circumference change was 0.09 cm/year [95% CI: 0.01, 0.18]. In participants with baseline BMI<25 kg/m(2, 1 kcal/g ED was associated with a waist circumference change of 0.17 cm/year [95% CI: 0.09, 0.25]. CONCLUSION: Our results suggest that lower ED diets do not prevent weight gain but have a weak yet potentially beneficial effect on the prevention of abdominal obesity as measured by waist circumference.
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West, Jane; Manchester, Ben; Wright, John; Lawlor, Debbie A; Waiblinger, Dagmar
2011-01-01
Summary West J, Manchester B, Wright J, Lawlor DA, Waiblinger D. Reliability of routine clinical measurements of neonatal circumferences and research measurements of neonatal skinfold thicknesses: findings from the Born in Bradford study. Paediatric and Perinatal Epidemiology 2011. Assessing neonatal size reliably is important for research and clinical practice. The aim of this study was to examine the reliability of routine clinical measurements of neonatal circumferences and of skinfold thicknesses assessed for research purposes. All measurements were undertaken on the same population of neonates born in a large maternity unit in Bradford, UK. Technical error of measurement (TEM), relative TEM and the coefficient of reliability are reported. Intra-observer TEMs for routine circumference measurements were all below 0.4 cm and were generally within ±2-times the mean. Inter-observer TEM ranged from 0.20 to 0.36 cm for head circumference, 0.19 to 0.39 cm for mid upper arm circumference and from 0.39 to 0.77 cm for abdominal circumference. Intra and inter-observer TEM for triceps skinfold thickness ranged from 0.22 to 0.35 mm and 0.15 to 0.54 mm, respectively. Subscapular skinfold thickness TEM values were 0.14 to 0.25 mm for intra-observer measurements and 0.17 to 0.63 mm for inter-observer measurements. Relative TEM values for routine circumferences were all below 4.00% but varied between 2.88% and 14.23% for research skinfold measurements. Reliability was mostly between 80% and 99% for routine circumference measurements and ≥70% for most research skinfold measurements. Routine clinical measurements of neonatal circumferences are reliably assessed in Bradford. Assessing skinfolds in neonates has variable reliability, but on the whole is good. The greater intra-observer, compared with inter-observer, reliability for both sets of measurements highlights the importance of having a minimal number of assessors whenever possible. PMID:21281329
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Energy Technology Data Exchange (ETDEWEB)
Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)
1998-01-05
White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.
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Directory of Open Access Journals (Sweden)
Adela Ionescu
2007-01-01
Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion
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Neck Circumference as a Predictive Indicator of CKD for High Cardiovascular Risk Patients
Directory of Open Access Journals (Sweden)
Ya-Fang Liu
2015-01-01
Full Text Available Background. Neck circumference (NC is an anthropometric measure of obesity for upper subcutaneous adipose tissue distribution which is associated with cardiometabolic risk. This study investigated whether NC is associated with indicators of chronic kidney disease (CKD for high cardiometabolic risk patients. Methods. A total of 177 consecutive patients who underwent the outpatient departments of cardiology were prospectively enrolled in the study. The patients were aged >20 years with normal renal function or with stages 1–4 CKD. A linear regression was performed using the Enter method to present an unadjusted R2, standardized coefficients, and standard error, and the Durbin-Watson test was used to assess residual independence. Results. Most anthropometric measurements from patients aged ≧65 were lower than those from patients aged <65, except for women’s waist circumference (WC and waist hip ratio. Female NC obtained the highest R2 values for 24 hr CCR, uric acid, microalbuminuria, hsCRP, triglycerides, and HDL compared to BMI, WC, and hip circumference. The significances of female NC with 24 hr CCR and uric acid were improved after adjusted age and serum creatinine. Conclusions. NC is associated with indicators of CKD for high cardiometabolic risk patients and can be routinely measured as easy as WC in the future.
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Semi-algebraic function rings and reflectors of partially ordered rings
Schwartz, Niels
1999-01-01
The book lays algebraic foundations for real geometry through a systematic investigation of partially ordered rings of semi-algebraic functions. Real spectra serve as primary geometric objects, the maps between them are determined by rings of functions associated with the spectra. The many different possible choices for these rings of functions are studied via reflections of partially ordered rings. Readers should feel comfortable using basic algebraic and categorical concepts. As motivational background some familiarity with real geometry will be helpful. The book aims at researchers and graduate students with an interest in real algebra and geometry, ordered algebraic structures, topology and rings of continuous functions.
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Gated-controlled electron pumping in connected quantum rings
International Nuclear Information System (INIS)
Lima, R.P.A.; Domínguez-Adame, F.
2014-01-01
We study the electronic transport across connected quantum rings attached to leads and subjected to time-harmonic side-gate voltages. Using the Floquet formalism, we calculate the net pumped current generated and controlled by the side-gate voltage. The control of the current is achieved by varying the phase shift between the two side-gate voltages as well as the Fermi energy. In particular, the maximum current is reached when the side-gate voltages are in quadrature. This new design based on connected quantum rings controlled without magnetic fields can be easily integrated in standard electronic devices. - Highlights: • We introduce and study a minimal setup to pump electrons through connected quantum rings. • Quantum pumping is achieved by time-harmonic side-gate voltages instead of the more conventional time-dependent magnetic fluxes. • Our new design could be easily integrated in standard electronic devices
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Rotating ring-ring electrode theory and experiment
Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kellyb, J.J.
2000-01-01
A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating
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Directory of Open Access Journals (Sweden)
Adriana Todingrante
2013-08-01
Full Text Available BACKGROUND: There is a prevalence increase of overweight and obesity in Indonesia. Central obesity can lead a variety of chronic diseases through the inflammatory process. There are some markers for low-grade chronic inflammatory, such as cathepsin S, high sensitivity C-reactive protein (hs-CRP, interleukin-1- beta (IL-1β. To our current interest that central obesity can lead to various chronic diseases through the inflammatory process, we conducted a study to investigate correlation of Cathepsin S, hs-CRP, IL-1β in men with central obesity. METHODS: A cross-sectional study was conducted. Seventy-eight selected subjects were examined to collect anthropometric data and prepared for sample collection. Collected samples were processed for the following biochemical analyses: fasting glucose, high density lipoprotein (HDL-cholesterol, triglyceride, serum glutamic oxaloacetic transaminase (SGOT, serum glutamate pyruvate transaminase (SGPT, cathepsin S, hs-CRP, and IL-1β. Data distribution and variable correlation were then statistically analyzed. RESULTS: There were significant correlations between waist circumference (WC and cathepsin S (p=0.030; r=0.214, hs-CRP and cathepsin S (p=0.007; r=0.276, triglyceride and IL-1β (p=0.019; r=-0.235, WC and systolic blood pressure (SBP (p=0.003; r=-0.312, WC and fasting glucose (p=0.000; r=0.380, WC and body mass index (BMI (p=0.000; r=0.708. CONCLUSIONS: Our study showed that cathepsin S was correlated with central obesity, suggesting that cathepsin S could be a potential inflammatory marker in central obesity in the future. KEYWORDS: obesity, inflammation, hs-CRP, cathepsin S, IL-1β, waist circumference.
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Topological ring currents in the "empty" ring of benzo-annelated perylenes.
Dickens, Timothy K; Mallion, Roger B
2011-01-27
Cyclic conjugation in benzo-annelated perylenes is examined by means of the topological π-electron ring currents calculated for each of their constituent rings, in a study that is an exact analogy of a recent investigation by Gutman et al. based on energy-effect values for the corresponding rings in each of these structures. "Classical" approaches, such as Kekulé structures, Clar "sextet" formulas, and circuits of conjugation, predict that the central ring in perylene is "empty" and thus contributes negligibly to cyclic conjugation. However, conclusions from the present calculations of topological ring currents agree remarkably with those arising from the earlier study involving energy-effect values in that, contrary to what would be predicted from the classical approaches, rings annelated in an angular fashion relative to the central ring of these perylene structures materially increase the extent of that ring's involvement in cyclic conjugation. It is suggested that such close quantitative agreement between the predictions of these two superficially very different indices (energy effect and topological ring current) might be due to the fact that, ultimately, both depend, albeit in ostensibly quite different ways, only on an adjacency matrix that contains information about the carbon-carbon connectivity of the conjugated system in question.
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Stability of Moonlets Embedded in Rings
Lewis, Mark C.; Burdon, C.
2011-04-01
Previous work on moonlets assumed that they were just a single indestructible spherical particle and focused primarily on the effects such a body would have on the surrounding ring material (Lewis and Stewart 2009, Icarus 199:387-412; Sremcevic et al. 2007, Nature 449:1019-1021). Both observations and numerical simulations of Saturn's small inner moons show them as very low density rubble piles (Porco et al. 2007, Science 318:1602). Unlike the small moons, moonlets embedded in the ring material will experience regular collisions with self gravity wakes tens of meters across. Even with a single spherical core, these collisions can lead to the shedding of significant amounts of accreted material. We describe numerical simulations in which we explore the parameters required for stability of moonlets embedded in the ring material. Because of their location well inside the Roche limit, these bodies require either higher densities or some internal strength in order to stay together. We explore how much strength is required for these moonlets to be stable against the regular impacts they sustain in that environment. This work was funded by NSF AAG award number 0907972.
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Development of large insulator rings for the TOKAMAK Fusion Test Reactor
International Nuclear Information System (INIS)
Brown, T.; Tobin, A.
1977-01-01
Research and development leading to the manufacture of large ceramic insulator rings for the TFTR (TOKAMAK Fusion Test Reactor). Material applictions, fabrication approach and testing activities are highlighted
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Fitzpatrick, Caroline; Pagani, Linda S; Barnett, Tracie A
2012-07-16
The relationship between early childhood television viewing and physical fitness in school age children has not been extensively studied using objective outcome measures. Using a sample of 1314 children from the Québec Longitudinal Study of Child Development, we examine the association between parental reports of weekly hours of television viewing, assessed at 29 and 53 months of age, and direct measures of second grade muscular fitness using performances on the standing long jump test (SLJ) and fourth grade waist circumference. Controlling for many potentially confounding child and family variables, each hour per week of television watched at 29 months corresponded to a .361 cm decrease in SLJ, 95% CI between -.576 and -.145. A one hour increase in average weekly television exposure from 29 to 53 months was associated with a further .285 cm reduction in SLJ test performance, 95% CI between -.436 and -.134 cm and corresponded to a .047 cm increase in waistline circumference, 95% CI between .001 and .094 cm. Watching television excessively in early childhood, may eventually compromise muscular fitness and waist circumference in children as they approach pubertal age.
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Directory of Open Access Journals (Sweden)
Fitzpatrick Caroline
2012-07-01
Full Text Available Abstract Background The relationship between early childhood television viewing and physical fitness in school age children has not been extensively studied using objective outcome measures. Methods Using a sample of 1314 children from the Québec Longitudinal Study of Child Development, we examine the association between parental reports of weekly hours of television viewing, assessed at 29 and 53 months of age, and direct measures of second grade muscular fitness using performances on the standing long jump test (SLJ and fourth grade waist circumference. Results Controlling for many potentially confounding child and family variables, each hour per week of television watched at 29 months corresponded to a .361 cm decrease in SLJ, 95% CI between -.576 and -.145. A one hour increase in average weekly television exposure from 29 to 53 months was associated with a further .285 cm reduction in SLJ test performance, 95% CI between -.436 and -.134 cm and corresponded to a .047 cm increase in waistline circumference, 95% CI between .001 and .094 cm. Interpretation Watching television excessively in early childhood, may eventually compromise muscular fitness and waist circumference in children as they approach pubertal age.
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Dalvand, Sahar; Koohpayehzadeh, Jalil; Karimlou, Masoud; Asgari, Fereshteh; Rafei, Ali; Seifi, Behjat; Niksima, Seyed Hassan; Bakhshi, Enayatollah
2015-01-01
Because the use of BMI (Body Mass Index) alone as a measure of adiposity has been criticized, in the present study our aim was to fit a latent variable model to simultaneously examine the factors that affect waist circumference (continuous outcome) and obesity (binary outcome) among Iranian adults. Data included 18,990 Iranian individuals aged 20-65 years that are derived from the third National Survey of Noncommunicable Diseases Risk Factors in Iran. Using latent variable model, we estimated the relation of two correlated responses (waist circumference and obesity) with independent variables including age, gender, PR (Place of Residence), PA (physical activity), smoking status, SBP (Systolic Blood Pressure), DBP (Diastolic Blood Pressure), CHOL (cholesterol), FBG (Fasting Blood Glucose), diabetes, and FHD (family history of diabetes). All variables were related to both obesity and waist circumference (WC). Older age, female sex, being an urban resident, physical inactivity, nonsmoking, hypertension, hypercholesterolemia, hyperglycemia, diabetes, and having family history of diabetes were significant risk factors that increased WC and obesity. Findings from this study of Iranian adult settings offer more insights into factors associated with high WC and high prevalence of obesity in this population.
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Assessing Factors Related to Waist Circumference and Obesity: Application of a Latent Variable Model
Directory of Open Access Journals (Sweden)
Sahar Dalvand
2015-01-01
Full Text Available Background. Because the use of BMI (Body Mass Index alone as a measure of adiposity has been criticized, in the present study our aim was to fit a latent variable model to simultaneously examine the factors that affect waist circumference (continuous outcome and obesity (binary outcome among Iranian adults. Methods. Data included 18,990 Iranian individuals aged 20–65 years that are derived from the third National Survey of Noncommunicable Diseases Risk Factors in Iran. Using latent variable model, we estimated the relation of two correlated responses (waist circumference and obesity with independent variables including age, gender, PR (Place of Residence, PA (physical activity, smoking status, SBP (Systolic Blood Pressure, DBP (Diastolic Blood Pressure, CHOL (cholesterol, FBG (Fasting Blood Glucose, diabetes, and FHD (family history of diabetes. Results. All variables were related to both obesity and waist circumference (WC. Older age, female sex, being an urban resident, physical inactivity, nonsmoking, hypertension, hypercholesterolemia, hyperglycemia, diabetes, and having family history of diabetes were significant risk factors that increased WC and obesity. Conclusions. Findings from this study of Iranian adult settings offer more insights into factors associated with high WC and high prevalence of obesity in this population.
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Directory of Open Access Journals (Sweden)
Emma Pomeroy
Full Text Available Low birth weight has been consistently associated with adult chronic disease risk. The thrifty phenotype hypothesis assumes that reduced fetal growth impacts some organs more than others. However, it remains unclear how birth weight relates to different body components, such as circumferences, adiposity, body segment lengths and limb proportions. We hypothesized that these components vary in their relationship to birth weight.We analysed the relationship between birth weight and detailed anthropometry in 1270 singleton live-born neonates (668 male from the Mater-University of Queensland Study of Pregnancy (Brisbane, Australia. We tested adjusted anthropometry for correlations with birth weight. We then performed stepwise multiple regression on birth weight of: body lengths, breadths and circumferences; relative limb to neck-rump proportions; or skinfold thicknesses. All analyses were adjusted for sex and gestational age, and used logged data.Circumferences, especially chest, were most strongly related to birth weight, while segment lengths (neck-rump, thigh, upper arm, and especially lower arm and lower leg were relatively weakly related to birth weight, and limb lengths relative to neck-rump length showed no relationship. Skinfolds accounted for 36% of birth weight variance, but adjusting for size (neck-rump, thigh and upper arm lengths, and head circumference, this decreased to 10%. There was no evidence that heavier babies had proportionally thicker skinfolds.Neonatal body measurements vary in their association with birth weight: head and chest circumferences showed the strongest associations while limb segment lengths did not relate strongly to birth weight. After adjusting for body size, subcutaneous fatness accounted for a smaller proportion of birth weight variance than previously reported. While heavier babies had absolutely thicker skinfolds, this was proportional to their size. Relative limb to trunk length was unrelated to birth
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... Support Contacts Lab Tracker/Copper Calculator Stories Programs & Research ... About Everything you need to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring visible around the corneo- ...
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THE RINGS OF CHARIKLO UNDER CLOSE ENCOUNTERS WITH THE GIANT PLANETS
Energy Technology Data Exchange (ETDEWEB)
Araujo, R. A. N.; Sfair, R.; Winter, O. C., E-mail: ran.araujo@gmail.com, E-mail: rsfair@feg.unesp.br, E-mail: ocwinter@gmail.com [UNESP - Univ. Estadual Paulista, Grupo de Dinâmica Orbital e Planetologia, CEP 12516-410, Guaratingueta, SP (Brazil)
2016-06-20
The Centaur population is composed of minor bodies wandering between the giant planets that frequently perform close gravitational encounters with these planets, leading to a chaotic orbital evolution. Recently, the discovery of two well-defined narrow rings was announced around the Centaur 10199 Chariklo. The rings are assumed to be in the equatorial plane of Chariklo and to have circular orbits. The existence of a well-defined system of rings around a body in such a perturbed orbital region poses an interesting new problem. Are the rings of Chariklo stable when perturbed by close gravitational encounters with the giant planets? Our approach to address this question consisted of forward and backward numerical simulations of 729 clones of Chariklo, with similar initial orbits, for a period of 100 Myr. We found, on average, that each clone experiences during its lifetime more than 150 close encounters with the giant planets within one Hill radius of the planet in question. We identified some extreme close encounters that were able to significantly disrupt or disturb the rings of Chariklo. About 3% of the clones lose their rings and about 4% of the clones have their rings significantly disturbed. Therefore, our results show that in most cases (more than 90%), the close encounters with the giant planets do not affect the stability of the rings in Chariklo-like systems. Thus, if there is an efficient mechanism that creates the rings, then these structures may be common among these kinds of Centaurs.
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Nicholson, P. D.
2001-11-01
A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the
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The phase structure of higher-dimensional black rings and black holes
International Nuclear Information System (INIS)
Emparan, Roberto; Harmark, Troels; Niarchos, Vasilis; Obers, Niels A.; RodrIguez, Maria J.
2007-01-01
We construct an approximate solution for an asymptotically flat, neutral, thin rotating black ring in any dimension D ≥ 5 by matching the near-horizon solution for a bent boosted black string, to a linearized gravity solution away from the horizon. The rotating black ring solution has a regular horizon of topology S 1 x S D-3 and incorporates the balancing condition of the ring as a zero-tension condition. For D = 5 our method reproduces the thin ring limit of the exact black ring solution. For D ≥ 6 we show that the black ring has a higher entropy than the Myers-Perry black hole in the ultra-spinning regime. By exploiting the correspondence between ultra-spinning black holes and black membranes on a two-torus, we take steps towards qualitatively completing the phase diagram of rotating blackfolds with a single angular momentum. We are led to propose a connection between MP black holes and black rings, and between MP black holes and black Saturns, through merger transitions involving two kinds of 'pinched' black holes. More generally, the analogy suggests an infinite number of pinched black holes of spherical topology leading to a complicated pattern of connections and mergers between phases
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Non-Linear Dynamics of Saturn's Rings
Esposito, L. W.
2016-12-01
Non-linear processes can explain why Saturn's rings are so active and dynamic. Ring systems differ from simple linear systems in two significant ways: 1. They are systems of granular material: where particle-to-particle collisions dominate; thus a kinetic, not a fluid description needed. Stresses are strikingly inhomogeneous and fluctuations are large compared to equilibrium. 2. They are strongly forced by resonances: which drive a non-linear response, that push the system across thresholds that lead to persistent states. Some of this non-linearity is captured in a simple Predator-Prey Model: Periodic forcing from the moon causes streamline crowding; This damps the relative velocity. About a quarter phase later, the aggregates stir the system to higher relative velocity and the limit cycle repeats each orbit, with relative velocity ranging from nearly zero to a multiple of the orbit average. Summary of Halo Results: A predator-prey model for ring dynamics produces transient structures like `straw' that can explain the halo morphology and spectroscopy: Cyclic velocity changes cause perturbed regions to reach higher collision speeds at some orbital phases, which preferentially removes small regolith particles; surrounding particles diffuse back too slowly to erase the effect: this gives the halo morphology; this requires energetic collisions (v ≈ 10m/sec, with throw distances about 200km, implying objects of scale R ≈ 20km).Transform to Duffing Eqn : With the coordinate transformation, z = M2/3, the Predator-Prey equations can be combined to form a single second-order differential equation with harmonic resonance forcing.Ring dynamics and history implications: Moon-triggered clumping explains both small and large particles at resonances. We calculate the stationary size distribution using a cell-to-cell mapping procedure that converts the phase-plane trajectories to a Markov chain. Approximating it as an asymmetric random walk with reflecting boundaries
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Directory of Open Access Journals (Sweden)
Cleliani de Cassia da Silva
2014-06-01
Full Text Available OBJECTIVE: To evaluate the correlation between neck circumference and insulin resistance and components of metabolic syndrome in adolescents with different adiposity levels and pubertal stages, as well as to determine the usefulness of neck circumference to predict insulin resistance in adolescents.METHODS:Cross-sectional study with 388 adolescents of both genders from ten to 19 years old. The adolescents underwent anthropometric and body composition assessment, including neck and waist circumferences, and biochemical evaluation. The pubertal stage was obtained by self-assessment, and the blood pressure, by auscultation. Insulin resistance was evaluated by the Homeostasis Model Assessment-Insulin Resistance. The correlation between two variables was evaluated by partial correlation coefficient adjusted for the percentage of body fat and pubertal stage. The performance of neck circumference to identify insulin resistance was tested by Receiver Operating Characteristic Curve.RESULTS: After the adjustment for percentage body fat and pubertal stage, neck circumference correlated with waist circumference, blood pressure, triglycerides and markers of insulin resistance in both genders.CONCLUSIONS: The results showed that the neck circumference is a useful tool for the detection of insulin resistance and changes in the indicators of metabolic syndrome in adolescents. The easiness of application and low cost of this measure may allow its use in Public Health services.
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Directory of Open Access Journals (Sweden)
Hossein Afshar
2016-08-01
Full Text Available Objectives: It is not clear what type of pre-crimped crown is more successful in achieving greater marginal adaptation following re-crimping. This study aimed to assess the changes in the circumference of 3M ESPE and MIB pre-crimped stainless steel crowns (SSCs for the primary maxillary and mandibular first and second molars following re-crimping.Materials and Methods: This was an in-vitro, experimental study. Initial photographs were obtained from the margins of 3M and MIB SSCs for the upper and lower primary molars using a digital camera. Crown margins were crimped by applying 0.2N force using 114 and 137 pliers. Post-crimping photographs were also obtained and the changes in crown circumference after crimping were calculated using AutoCad software. The percentage of reduction in the circumference of crowns for each tooth was statistically analyzed based on the type of crown using student t-test. The effect of crown design and the associated teeth on the decreased circumference percentage was statistically analyzed by two-sided ANOVA.Results: The percentage of reduction in lower E SSC circumference was 3.71±0.39% in MIB and 6.29±0.62% in 3M crowns. These values were 3.55±0.55% and 7.15±1.13% for the lower Ds, and 3.95±0.43 and 6.24±0.85% for the upper Ds, respectively. For the upper Es, these values were found to be 3.12±0.65% and 5.14±0.94%, respectively. For each tooth, a significant difference was found between MIB and 3M SSCs in terms of the percentage of reduction in crown circumference following crimping. The magnitude of this reduction was smaller in MIB compared to 3M SSCs (P<0.001.Conclusion: Considering the significant reduction in the marginal circumference of pre-crimped SSCs following re-crimping, it appears that this manipulation must be necessarily performed for MIB and 3M pre-crimped SSCs. By using 3M SSCs, higher marginal adaptation can be achieved following crimping.
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MIGRATION OF SMALL MOONS IN SATURN's RINGS
Energy Technology Data Exchange (ETDEWEB)
Bromley, Benjamin C. [Department of Physics and Astronomy, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112 (United States); Kenyon, Scott J., E-mail: bromley@physics.utah.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)
2013-02-20
The motions of small moons through Saturn's rings provide excellent tests of radial migration models. In theory, torque exchange between these moons and ring particles leads to radial drift. We predict that moons with Hill radii r {sub H} {approx} 2-24 km should migrate through the A ring in 1000 yr. In this size range, moons orbiting in an empty gap or in a full ring eventually migrate at the same rate. Smaller moons or moonlets-such as the propellers-are trapped by diffusion of disk material into corotating orbits, creating inertial drag. Larger moons-such as Pan or Atlas-do not migrate because of their own inertia. Fast migration of 2-24 km moons should eliminate intermediate-size bodies from the A ring and may be responsible for the observed large-radius cutoff of r {sub H} {approx} 1-2 km in the size distribution of the A ring's propeller moonlets. Although the presence of Daphnis (r {sub H} Almost-Equal-To 5 km) inside the Keeler gap challenges this scenario, numerical simulations demonstrate that orbital resonances and stirring by distant, larger moons (e.g., Mimas) may be important factors. For Daphnis, stirring by distant moons seems the most promising mechanism to halt fast migration. Alternatively, Daphnis may be a recent addition to the ring that is settling into a low inclination orbit in {approx}10{sup 3} yr prior to a phase of rapid migration. We provide predictions of observational constraints required to discriminate among possible scenarios for Daphnis.
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Zeng, Xiang; Xu, Xijin; Zhang, Yuling; Li, Weiqiu; Huo, Xia
2017-10-01
The purpose of this study was to investigate the associations between birth weight, chest circumference, and lung function in preschool children from e-waste exposure area. A total of 206 preschool children from Guiyu (an e-waste recycling area) and Haojiang and Xiashan (the reference areas) in China were recruited and required to undergo physical examination, blood tests, and lung function tests during the study period. Birth outcome such as birth weight and birth height were obtained by questionnaire. Children living in the e-waste-exposed area have a lower birth weight, chest circumference, height, and lung function when compare to their peers from the reference areas (all p value <0.05). Both Spearman and partial correlation analyses showed that birth weight and chest circumference were positively correlated with lung function levels including forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV 1 ). After adjustment for the potential confounders in further linear regression analyses, birth weight, and chest circumference were positively associated with lung function levels, respectively. Taken together, birth weight and chest circumference may be good predictors for lung function levels in preschool children.
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Spin separation driven by quantum interference in ballistic rings
International Nuclear Information System (INIS)
Bellucci, S; Onorato, P
2008-01-01
We propose an all-electrical nanoscopic structure where a pure spin current is induced in the transverse probes attached to a quantum-coherent ballistic quasi-one-dimensional ring when conventional unpolarized charge current is injected through its longitudinal leads. The study is essentially based on the spin-orbit coupling (SOC) arising from the laterally confining electric field (β-SOC). This sets the basic difference with other works employing mesoscopic rings with the conventional Rashba SO term (α-SOC). The β-SOC ring generates oscillations of the predicted spin Hall current due to spin-sensitive quantum-interference effects caused by the difference in phase acquired by opposite spins states traveling clockwise and counterclockwise. We focus on single-channel transport and solve analytically the spin polarization of the current. We relate the presence of a polarized spin current with the peaks in the longitudinal conductance.
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A model of ATL ground motion for storage rings
International Nuclear Information System (INIS)
Wolski, Andrzej; Walker, Nicholas J.
2003-01-01
Low emittance electron storage rings, such as those used in third generation light sources or linear collider damping rings, rely for their performance on highly stable alignment of the lattice components. Even if all vibration and environmental noise sources could be suppressed, diffusive ground motion will lead to orbit drift and emittance growth. Understanding such motion is important for predicting the performance of a planned accelerator and designing a correction system. A description (known as the ATL model) of ground motion over relatively long time scales has been developed and has become the standard for studies of the long straight beamlines in linear colliders. Here, we show how the model may be developed to include beamlines of any geometry. We apply the model to the NLC and TESLA damping rings, to compare their relative stability under different conditions
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Preparation for electron ring - plasma ring merging experiments in RECE-MERGE
International Nuclear Information System (INIS)
Taggart, D.; Sekiguchi, A.; Fleischmann, H.H.
1986-01-01
The formation of a mixed-CT using relativistic electron rings and gun-produced plasma rings by MERGE-ing them axially is simulated. This process is similar to the axial stacking of relativistic electron rings in RECE-Christa. The results of their first plasm production experiment are reported here. After study of the gun-produced plasma's properties is completed, the gun will be mounted at the downstream end of the vacuum tank and the source of relativistic electron rings will be at the upstream end. The two rings, formed at opposite ends of the tank, will be translated axially and merged
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Iterative image-domain ring artifact removal in cone-beam CT
Liang, Xiaokun; Zhang, Zhicheng; Niu, Tianye; Yu, Shaode; Wu, Shibin; Li, Zhicheng; Zhang, Huailing; Xie, Yaoqin
2017-07-01
Ring artifacts in cone beam computed tomography (CBCT) images are caused by pixel gain variations using flat-panel detectors, and may lead to structured non-uniformities and deterioration of image quality. The purpose of this study is to propose a method of general ring artifact removal in CBCT images. This method is based on the polar coordinate system, where the ring artifacts manifest as stripe artifacts. Using relative total variation, the CBCT images are first smoothed to generate template images with fewer image details and ring artifacts. By subtracting the template images from the CBCT images, residual images with image details and ring artifacts are generated. As the ring artifact manifests as a stripe artifact in a polar coordinate system, the artifact image can be extracted by mean value from the residual image; the image details are generated by subtracting the artifact image from the residual image. Finally, the image details are compensated to the template image to generate the corrected images. The proposed framework is iterated until the differences in the extracted ring artifacts are minimized. We use a 3D Shepp-Logan phantom, Catphan©504 phantom, uniform acrylic cylinder, and images from a head patient to evaluate the proposed method. In the experiments using simulated data, the spatial uniformity is increased by 1.68 times and the structural similarity index is increased from 87.12% to 95.50% using the proposed method. In the experiment using clinical data, our method shows high efficiency in ring artifact removal while preserving the image structure and detail. The iterative approach we propose for ring artifact removal in cone-beam CT is practical and attractive for CBCT guided radiation therapy.
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Predicting waist circumference from body mass index.
Bozeman, Samuel R; Hoaglin, David C; Burton, Tanya M; Pashos, Chris L; Ben-Joseph, Rami H; Hollenbeak, Christopher S
2012-08-03
Being overweight or obese increases risk for cardiometabolic disorders. Although both body mass index (BMI) and waist circumference (WC) measure the level of overweight and obesity, WC may be more important because of its closer relationship to total body fat. Because WC is typically not assessed in clinical practice, this study sought to develop and verify a model to predict WC from BMI and demographic data, and to use the predicted WC to assess cardiometabolic risk. Data were obtained from the Third National Health and Nutrition Examination Survey (NHANES) and the Atherosclerosis Risk in Communities Study (ARIC). We developed linear regression models for men and women using NHANES data, fitting waist circumference as a function of BMI. For validation, those regressions were applied to ARIC data, assigning a predicted WC to each individual. We used the predicted WC to assess abdominal obesity and cardiometabolic risk. The model correctly classified 88.4% of NHANES subjects with respect to abdominal obesity. Median differences between actual and predicted WC were -0.07 cm for men and 0.11 cm for women. In ARIC, the model closely estimated the observed WC (median difference: -0.34 cm for men, +3.94 cm for women), correctly classifying 86.1% of ARIC subjects with respect to abdominal obesity and 91.5% to 99.5% as to cardiometabolic risk.The model is generalizable to Caucasian and African-American adult populations because it was constructed from data on a large, population-based sample of men and women in the United States, and then validated in a population with a larger representation of African-Americans. The model accurately estimates WC and identifies cardiometabolic risk. It should be useful for health care practitioners and public health officials who wish to identify individuals and populations at risk for cardiometabolic disease when WC data are unavailable.
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Dynamics of the evaporative dewetting of a volatile liquid film confined within a circular ring.
Sun, Wei; Yang, Fuqian
2015-04-07
The dewetting dynamics of a toluene film confined within a copper ring on a deformable PMMA film is studied. The toluene film experiences evaporation and dewetting, which leads to the formation of a circular contact line around the center of the copper ring. The contact line recedes smoothly toward the copper ring at a constant velocity until reaching a dynamic "stick" state to form the first circular polymer ridge. The average receding velocity is found to be dependent on the dimensions of the copper ring (the copper ring diameter and the cross-sectional diameter of the copper wire) and the thickness of the PMMA films. A model is presented to qualitatively explain the evaporative dewetting phenomenon.
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Oscillations of quantum transport through double-AB rings with magnetic impurity
International Nuclear Information System (INIS)
Gao Yingfang; Liang, J-Q
2006-01-01
We have studied the effect of impurity scattering on the quantum transport through double AB rings in the presence of spin-flipper in the middle lead in terms of one-dimensional quantum waveguide theory. The electron interacts with the impurity through the exchange interaction leading to spin-flip scattering. Transmissions in the spin-flipped and non-spin-flipped channels are calculated explicitly. It is found that the overall transmission and the conductance are distorted due to the impurity scattering. The extent of distortion not only depends on the strength of the impurity potential but also on the impurity position. Moreover, the transmission probability and the conductance are modulated by the magnetic flux, the size of the ring and the impurity potential strength as well
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Non-Linear Dynamics of Saturn’s Rings
Esposito, Larry W.
2015-11-01
Non-linear processes can explain why Saturn’s rings are so active and dynamic. Ring systems differ from simple linear systems in two significant ways: 1. They are systems of granular material: where particle-to-particle collisions dominate; thus a kinetic, not a fluid description needed. We find that stresses are strikingly inhomogeneous and fluctuations are large compared to equilibrium. 2. They are strongly forced by resonances: which drive a non-linear response, pushing the system across thresholds that lead to persistent states.Some of this non-linearity is captured in a simple Predator-Prey Model: Periodic forcing from the moon causes streamline crowding; This damps the relative velocity, and allows aggregates to grow. About a quarter phase later, the aggregates stir the system to higher relative velocity and the limit cycle repeats each orbit.Summary of Halo Results: A predator-prey model for ring dynamics produces transient structures like ‘straw’ that can explain the halo structure and spectroscopy: This requires energetic collisions (v ≈ 10m/sec, with throw distances about 200km, implying objects of scale R ≈ 20km).Transform to Duffing Eqn : With the coordinate transformation, z = M2/3, the Predator-Prey equations can be combined to form a single second-order differential equation with harmonic resonance forcing.Ring dynamics and history implications: Moon-triggered clumping at perturbed regions in Saturn’s rings creates both high velocity dispersion and large aggregates at these distances, explaining both small and large particles observed there. We calculate the stationary size distribution using a cell-to-cell mapping procedure that converts the phase-plane trajectories to a Markov chain. Approximating the Markov chain as an asymmetric random walk with reflecting boundaries allows us to determine the power law index from results of numerical simulations in the tidal environment surrounding Saturn. Aggregates can explain many dynamic aspects
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DEFF Research Database (Denmark)
Holm, Bente; Kristensen, Morten Tange; Husted, Henrik
2011-01-01
OBJECTIVE: To (1) quantify changes in knee-extension strength and functional-performance at discharge after fast-track total hip arthroplasty (THA) and (2) investigate whether these changes correlate to changes in thigh and knee circumference (ie, swelling) or pain. DESIGN: A prospective, descrip......OBJECTIVE: To (1) quantify changes in knee-extension strength and functional-performance at discharge after fast-track total hip arthroplasty (THA) and (2) investigate whether these changes correlate to changes in thigh and knee circumference (ie, swelling) or pain. DESIGN: A prospective......, descriptive, hypothesis-generating study. SETTING: A special unit for fast-track hip and knee arthroplasty operations at a university hospital. PARTICIPANTS: Twenty-four patients (20 women and 4 men; ages 69 ± 6.1 years) scheduled for primary unilateral THA. METHODS: All patients were evaluated before surgery......, except for hip pain. The average loss in knee-extension strength after surgery (32%, P = .01) did not correlate with increased thigh circumference (6%, P
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Development of large insulator rings for the Tokamak Fusion Test Reactor
International Nuclear Information System (INIS)
Brown, T.; Tobin, A.
1978-01-01
This paper discusses research and development leading to the manufacture of large ceramic insulator rings for the TFTR (TOKAMAK Fusion Test Reactor). Material applications, fabrication approach and testing activities are highlighted
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Absence of localization in a disordered one-dimensional ring threaded by an Aharonov-Bohm flux
International Nuclear Information System (INIS)
Heinrichs, Jean
2009-01-01
Absence of localization is demonstrated analytically to leading order in weak disorder in a one-dimensional Anderson model of a ring threaded by an Aharonov-Bohm (AB) flux. The result follows from adapting an earlier perturbation treatment of disorder in a superconducting ring subjected to an imaginary vector potential proportional to a depinning field for flux lines bound to random columnar defects parallel to the axis of the ring. The absence of localization in the ring threaded by an AB flux for sufficiently weak disorder is compatible with large free-electron-type persistent current obtained in recent studies of the above model.
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Modi, Payal; Nasrin, Sabiha; Hawes, Meagan; Glavis-Bloom, Justin; Alam, Nur H; Hossain, M Iqbal; Levine, Adam C
2015-01-01
Background: Undernutrition contributes to 45% of all deaths in children children with diarrhea and possible dehydration. Objective: This study assessed the validity of different measures of undernutrition in children with diarrhea. Methods: A prospective cohort study was conducted at an urban hospital in Bangladesh. Children children for screening, of which 1025 were eligible, 850 were enrolled, and 721 had complete data for analysis. Anthropometric measurements, including weight-for-age z score (WAZ), weight-for-length z score (WLZ), midupper arm circumference (MUAC), and midupper arm circumference z score (MUACZ), were calculated pre- and posthydration in all patients. Measurements were evaluated for their ability to correctly identify undernutrition in children with varying degrees of dehydration. Results: Of the 721 patients with full data for analysis, the median percent dehydration was 4%. Of the 4 measures evaluated, MUAC and MUACZ demonstrated 92–94% agreement pre- and posthydration compared with 69–76% for WAZ and WLZ. Although each 1% change in hydration status was found to change weight-for-age by 0.0895 z scores and weight-for-length by 0.1304 z scores, MUAC and MUACZ were not significantly affected by dehydration status. Weight-based measures misclassified 12% of children with severe underweight and 14% with severe acute malnutrition (SAM) compared with only 1–2% for MUAC and MUACZ. Conclusions: MUAC and MUACZ were the most accurate predictors of undernutrition in children with diarrhea. WAZ and WLZ were significantly affected by dehydration status, leading to the misdiagnosis of many patients on arrival with severe underweight and SAM. This trial was registered at clinicaltrials.gov as NCT02007733. PMID:25972523
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Self-organized formation of GaSb/GaAs quantum rings.
Timm, R; Eisele, H; Lenz, A; Ivanova, L; Balakrishnan, G; Huffaker, D L; Dähne, M
2008-12-19
Ring-shaped GaSb/GaAs quantum dots, grown by molecular beam epitaxy, were studied using cross-sectional scanning tunneling microscopy. These quantum rings have an outer shape of a truncated pyramid with baselengths around 15 nm and heights of about 2 nm but are characterized by a clear central opening extending over about 40% of the outer baselength. They form spontaneously during the growth and subsequent continuous capping of GaSb/GaAs quantum dots due to the large strain and substantial As-for-Sb exchange reactions leading to strong Sb segregation.
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Double-Slot Hybrid Plasmonic Ring Resonator Used for Optical Sensors and Modulators
Directory of Open Access Journals (Sweden)
Xu Sun
2015-11-01
Full Text Available An ultra-high sensitivity double-slot hybrid plasmonic (DSHP ring resonator, used for optical sensors and modulators, is developed. Due to high index contrast, as well as plasmonic enhancement, a considerable part of the optical energy is concentrated in the narrow slots between Si and plasmonic materials (silver is used in this paper, which leads to high sensitivity to the infiltrating materials. By partial opening of the outer plasmonic circular sheet of the DSHP ring, a conventional side-coupled silicon on insulator (SOI bus waveguide can be used. Experimental results demonstrate ultra-high sensitivity (687.5 nm/RIU of the developed DSHP ring resonator, which is about five-times higher than for the conventional Si ring with the same geometry. Further discussions show that a very low detection limit (5.37 × 10−6 RIU can be achieved after loaded Q factor modifications. In addition, the plasmonic metal structures offer also the way to process optical and electronic signals along the same hybrid plasmonic circuits with small capacitance (~0.275 fF and large electric field, which leads to possible applications in compact high-efficiency electro-optic modulators, where no extra electrodes for electronic signals are required.
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The dynamics of rings around small, irregular bodies
Sicardy, Bruno
2017-06-01
Stellar occultations revealed the presence of two dense rings around the Centaur object (10199) Chariklo (Braga-Ribas et al., Nature 508, 72, 2014). This is the first ring system discovered around an object that is not a giant planet, suggesting that rings may exist around numerous bodies in the solar system. Chariklo's rings roughly reside at the outer limit of the Roche zone of the body. Moreover, the main ring has sharp edges, which call for the presence of putative shepherd satellites. Those characteristics give an image of Chariklo's rings that are rather similar, in terms of dynamics, to those surrounding the gaseous planets.An important difference exists, however, between giant planets and small bodies: the formers are highly axisymmetric, while the latters can support mass anomalies (eg surface topographic features) or non-spherical shapes (eg an ellipsoidal figure of equilibrium) that involve masses, relative to the body itself, as large as 10-4-10-3.We investigate the effect of non-axisymmetric terms in the potential of the body upon a collisional debris disk that initially surrounds a small irregular body. We show that the corotation points being maxima of energy, dissipative collisions remove the particles from the corotation zone over short time scales (< 106 years). Moreover, the Lindblad resonances inside the corotation radius create torques that drive the particles onto the surface of the central body. Conversely, the outer Lindblad resonances push the disk material beyond the outer 3/2 and 2/1 Lindblad resonances.Taking as an example Chariklo's ring system, for which recent data have been obtained from stellar occultations, we show that the Lindblad resonant torques actuate over short time scales (< 106 years). This general picture offers a natural explanation of the presence of dense rings at the outer limit of Chariklo's Roche zone, and their absence closer to the body.The work leading to this results has received funding from the European
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Planar LIF observation of unburned fuel escaping the upper ring-land crevice in an SI engine
Energy Technology Data Exchange (ETDEWEB)
Green, R.M.; Cloutman, L.D.
1997-01-01
PLIF has been used to observe the in-cylinder transport of unburned fuel that, while trapped in the ring-land and ring-groove crevices, survives combustion in the propagating flame. Away from the top-ring gap, we detect a wall-jet comprised of unburned charge exiting the top ring-land crevice opening. At the location of the top-ring gap, we observed unburned fuel lying in the cool boundary layer along the cylinder wall during the later stages of the expansion stroke. This layer is scraped into the roll-up vortex during the exhaust stroke. These data lead us to conclude that away from the end gap, unburned, high pressure charge, trapped between the two compression rings escapes as a wall jet after ring-reversal near the bottom center. Conversely, at the ring gap, when the cylinder pressure drops below the pressure between the compression rings, the trapped charge escapes through the gap and forms a thin layer on the cylinder wall.
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Directory of Open Access Journals (Sweden)
Chi-Hang Kuok
2016-12-01
Conclusion: Parturients with greater abdominal circumference value have a higher level of sensory blockade at 5 minutes after spinal anesthesia. Abdominal circumference cannot predict the maximum sensory blockade level and the incidence of hypotension.
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Neck circumference as a screening measure of overweight/obesity among Indian adults
Directory of Open Access Journals (Sweden)
Mondal Nitish
2016-09-01
Full Text Available Neck circumference (NC is an anthropometric measurement of differentiating body fat distributions and a marker of upper subcutaneous adiposity. The present study highlights the association and importance of NC as a suitable proxy screening measure of overweight/obesity as compared to the conventional anthropometric variables used among Indian adults. The present community based cross-sectional study was undertaken among 1169 Karbi adults (males: 625; females: 544 residing in Karbi Anglong district of Assam, Northeast India, who were selected through a multistage stratified random sampling method. Height, weight, waist circumference (WC, hip circumference (HC and NC were recorded using standard procedures. The body mass index (BMI was calculated and prevalence of overweight/obesity was assessed using standard cut-offs. The prevalence of obesity using BMI (≥25.00 kg m-2 was 15.52% and 15.26% among males and females, respectively (p≥0.05.The prevalence of obesity using NC was observed to be significantly higher among males (48.80% than females (19.12% (p<0.01. The binary logistic regression analysis showed that NC predicted obesity over the conventional anthropometric variables with reasonable accuracy (p<0.01. The ROC-AUC analysis showed a relatively greater significant association between BMI, WC and HC and NC for obesity (p<0.01. Thus, NC appears to be a potentially simple, easyto- use screening measure for predicting obesity among adults. Further studies are required to validate its use for screening of obesity among other ethnic populations in India.
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Ring faults and ring dikes around the Orientale basin on the Moon.
Andrews-Hanna, Jeffrey C; Head, James W; Johnson, Brandon; Keane, James T; Kiefer, Walter S; McGovern, Patrick J; Neumann, Gregory A; Wieczorek, Mark A; Zuber, Maria T
2018-08-01
The Orientale basin is the youngest and best-preserved multiring impact basin on the Moon, having experienced only modest modification by subsequent impacts and volcanism. Orientale is often treated as the type example of a multiring basin, with three prominent rings outside of the inner depression: the Inner Rook Montes, the Outer Rook Montes, and the Cordillera. Here we use gravity data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to reveal the subsurface structure of Orientale and its ring system. Gradients of the gravity data reveal a continuous ring dike intruded into the Outer Rook along the plane of the fault associated with the ring scarp. The volume of this ring dike is ~18 times greater than the volume of all extrusive mare deposits associated with the basin. The gravity gradient signature of the Cordillera ring indicates an offset along the fault across a shallow density interface, interpreted to be the base of the low-density ejecta blanket. Both gravity gradients and crustal thickness models indicate that the edge of the central cavity is shifted inward relative to the equivalent Inner Rook ring at the surface. Models of the deep basin structure show inflections along the crust-mantle interface at both the Outer Rook and Cordillera rings, indicating that the basin ring faults extend from the surface to at least the base of the crust. Fault dips range from 13-22° for the Cordillera fault in the northeastern quadrant, to 90° for the Outer Rook in the northwestern quadrant. The fault dips for both outer rings are lowest in the northeast, possibly due to the effects of either the direction of projectile motion or regional gradients in pre-impact crustal thickness. Similar ring dikes and ring faults are observed around the majority of lunar basins.
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Nutritional profile of the elderly - Relationship obesity and waist circumference sixty years after
Directory of Open Access Journals (Sweden)
Ramara Kadija Fonseca Santos
2014-05-01
Full Text Available In the aging process the metabolic changes can cause changes in health, including nutritional status, making the absorption of nutrients or promoting the accumulation of adipose tissue. Given this, this study aimed to assess the nutritional status of the participants in an open design for the elderly, through documentary analysis of values of Body Mass Index (BMI and Waist Circumference (WC. The analyzed results show a relationship between aging and the accumulation of visceral fat, since individuals considered eutrophic demonstrated a strong CC, as the data below, in which 11.53% of the data showed that subjects with low birth weight, 42,32 % normal weight, overweight and 46.5%, comparing with 80.76% of the values with large waist circumference, increasing the risk of developing some type of metabolic disease.
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NUTRITIONAL PROFILE OF THE ELDERLY - RELATIONSHIP OBESITY AND WAIST CIRCUMFERENCE SIXTY YEARS AFTER
Directory of Open Access Journals (Sweden)
Ramara Kadija Fonseca Santos
2014-08-01
Full Text Available In the aging process the metabolic changes can cause changes in health, including nutritional status, making the absorption of nutrients or promoting the accumulation of adipose tissue. Given this, this study aimed to assess the nutritional status of the participants in an open design for the elderly, through documentary analysis of values of Body Mass Index (BMI and Waist Circumference (WC. The analyzed results show a relationship between aging and the accumulation of visceral fat, since individuals considered eutrophic demonstrated a strong CC, as the data below, in which 11.53% of the data showed that subjects with low birth weight, 42,32 % normal weight, overweight and 46.5%, comparing with 80.76% of the values with large waist circumference, increasing the risk of developing some type of metabolic disease.
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Auslander, Maurice
2014-01-01
This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions
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The Rotating Ring-Ring Electrode. Theory and Experiment
Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kelly, J.J.
2000-01-01
A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating
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The effect of height, weight and head circumference on gross motor development in achondroplasia.
Ireland, Penelope Jane; Ware, Robert S; Donaghey, Samantha; McGill, James; Zankl, Andreas; Pacey, Verity; Ault, Jenny; Savarirayan, Ravi; Sillence, David; Thompson, Elizabeth; Townshend, Sharron; Johnston, Leanne M
2013-02-01
This study aimed to investigate whether height, weight, head circumference and/or relationships between these factors are associated with gross motor milestone acquisition in children with achondroplasia. Population-based data regarding timing of major gross motor milestones up to 5 years were correlated with height, weight and head circumference at birth and 12 months in 48 children with achondroplasia born in Australia and New Zealand between 2000 and 2009. Although as a group children with achondroplasia showed delayed gross motor skill acquisition, within group differences in height, weight or head circumference did not appear to influence timing of gross motor skills before 5 years. The exception was lie to sit transitioning, which appears likely to occur earlier if the child is taller and heavier at 12 months, and later if the child has significant head-to-body disproportion. This is the first study to investigate the relationship between common musculoskeletal impairments associated with achondroplasia and timing of gross motor achievement. Identification of the musculoskeletal factors that exacerbate delays in transitioning from lying to sitting will assist clinicians to provide more proactive assessment, advice and intervention regarding motor skill acquisition for this population. © 2013 The Authors. Journal of Paediatrics and Child Health © 2013 Paediatrics and Child Health Division (Royal Australasian College of Physicians).
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Yang, R-F; Liu, X-Y; Lin, Z; Zhang, G
2015-01-01
Coronary disease is analyzed through common lipid profiles, but these analyses fail to account for residual risk due to abdominal weight and elevated TG levels. We aimed to investigate the relationship between the waist circumference × triglyceride index (WT index) and the Coronary Artery Score (CAS) in patients with coronary heart disease. 346 patients in our Cardiology Department were recruited from September 2007 to August 2011 and divided into two groups according to whether the patients presented with metabolic syndrome. We performed coronary angiography using the standard Judkins method. The severity of coronary artery stenosis and the CAS were calculated and analyzed with a computerized quantitative analysis system. The signs index, which includes the body mass index (BMI), waist circumference, hip circumference, waist-hip-ratio, and waist-height-ratio, the blood glucose and blood lipid index of all the patients were collected and used to calculate the WT index (waist circumference x triglyceride index. We performed a correlative analysis with age, gender, body mass index, blood glucose and blood lipid, blood pressure and other risk indicators of all patients as the dependent variables and the CAS as the independent variable. We show that the CAS is positively correlated to the WT index. Several lipid profiles and waist circumference were significantly associated with the CAS. The WT index is correlated to the CAS and is a good predictor for the development of coronary artery disease; it can be applied in the clinic for early intervention in populations at risk for coronary heart disease.
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Wear Analysis of Top Piston Ring to Reduce Top Ring Reversal Bore Wear
Directory of Open Access Journals (Sweden)
P. Ilanthirayan
2017-12-01
Full Text Available The piston rings are the most important part in engine which controls the lubricating oil consumption and blowby of the gases. The lubricating film of oil is provided to seal of gases towards crankcase and also to give smooth friction free translatory motion between rings and liner. Of the three rings present top ring is more crucial as it does the main work of restricting gases downwards the crankcase. Boundary lubrication is present at the Top dead centre (TDC and Bottom dead centre (BDC of the liner surface. In addition to this, top ring is exposed to high temperature gases which makes the oil present near the top ring to get evaporated and decreasing its viscosity, making metal-metal contact most of the time. Due to this at TDC, excess wear happens on the liner which is termed as Top ring reversal bore wear. The wear rate depends upon many parameters such as lubrication condition, viscosity index, contact type, normal forces acting on ring, geometry of ring face, surface roughness, material property. The present work explores the wear depth for different geometries of barrel ring using Finite Element model with the help of Archard wear law and the same is validated through experimentation. The study reveals that Asymmetric barrel rings have less contact pressure which in turn reduces the wear at Top dead centre.
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DEFF Research Database (Denmark)
Du, Huaidong; van der A, Daphne L; Ginder, Vanessa
2009-01-01
BACKGROUND: Experimental studies show that a reduction in dietary energy density (ED) is associated with reduced energy intake and body weight. However, few observational studies have investigated the role of ED on long-term weight and waist circumference change. METHODS AND PRINCIPAL FINDINGS: T...... not prevent weight gain but have a weak yet potentially beneficial effect on the prevention of abdominal obesity as measured by waist circumference....
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Akhmetov, D G
2009-01-01
This text on vortex rings covers their theoretical foundation, systematic investigations, and practical applications such as the extinction of fires at gushing oil wells. It pays special attention to the formation and motion of turbulent vortex rings.
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Kershaw, Kiarri N; Hankinson, Arlene L; Liu, Kiang; Reis, Jared P; Lewis, Cora E; Loria, Catherine M; Carnethon, Mercedes R
2014-03-01
Few studies have examined longitudinal associations between close social relationships and weight change. Using data from 3,074 participants in the Coronary Artery Risk Development in Young Adults Study who were examined in 2000, 2005, and 2010 (at ages 33-45 years in 2000), we estimated separate logistic regression random-effects models to assess whether patterns of exposure to supportive and negative relationships were associated with 10% or greater increases in body mass index (BMI) (weight (kg)/height (m)(2)) and waist circumference. Linear regression random-effects modeling was used to examine associations of social relationships with mean changes in BMI and waist circumference. Participants with persistently high supportive relationships were significantly less likely to increase their BMI values and waist circumference by 10% or greater compared with those with persistently low supportive relationships after adjustment for sociodemographic characteristics, baseline BMI/waist circumference, depressive symptoms, and health behaviors. Persistently high negative relationships were associated with higher likelihood of 10% or greater increases in waist circumference (odds ratio = 1.62, 95% confidence interval: 1.15, 2.29) and marginally higher BMI increases (odds ratio = 1.50, 95% confidence interval: 1.00, 2.24) compared with participants with persistently low negative relationships. Increasingly negative relationships were associated with increases in waist circumference only. These findings suggest that supportive relationships may minimize weight gain, and that adverse relationships may contribute to weight gain, particularly via central fat accumulation.
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Changes in waist circumference and mortality in middle-aged men and women
DEFF Research Database (Denmark)
Berentzen, Tina Landsvig; Jakobsen, Marianne Uhre; Halkjaer, Jytte
2010-01-01
Waist circumference (WC) adjusted for body mass index (BMI) is positively associated with mortality, but the association with changes in WC is less clear. We investigated the association between changes in WC and mortality in middle-aged men and women, and evaluated the influence from concurrent...
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FUZZY RINGS AND ITS PROPERTIES
Directory of Open Access Journals (Sweden)
Karyati Karyati
2017-01-01
One of algebraic structure that involves a binary operation is a group that is defined an un empty set (classical with an associative binary operation, it has identity elements and each element has an inverse. In the structure of the group known as the term subgroup, normal subgroup, subgroup and factor group homomorphism and its properties. Classical algebraic structure is developed to algebraic structure fuzzy by the researchers as an example semi group fuzzy and fuzzy group after fuzzy sets is introduced by L. A. Zadeh at 1965. It is inspired of writing about semi group fuzzy and group of fuzzy, a research on the algebraic structure of the ring is held with reviewing ring fuzzy, ideal ring fuzzy, homomorphism ring fuzzy and quotient ring fuzzy with its properties. The results of this study are obtained fuzzy properties of the ring, ring ideal properties fuzzy, properties of fuzzy ring homomorphism and properties of fuzzy quotient ring by utilizing a subset of a subset level and strong level as well as image and pre-image homomorphism fuzzy ring. Keywords: fuzzy ring, subset level, homomorphism fuzzy ring, fuzzy quotient ring
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Three dimensional atom probe imaging of GaAsSb quantum rings.
Beltrán, A M; Marquis, E A; Taboada, A G; Ripalda, J M; García, J M; Molina, S I
2011-07-01
Unambiguous evidence of ring-shaped self-assembled GaSb nanostructures grown by molecular beam epitaxy is presented on the basis of atom-probe tomography reconstructions and dark field transmission electron microscopy imaging. The GaAs capping process causes a strong segregation of Sb out of the center of GaSb quantum dots, leading to the self-assembled GaAs(x)Sb(1-x) quantum rings of 20-30 nm in diameter with x ∼ 0.33. Copyright © 2011 Elsevier B.V. All rights reserved.
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HISTRAP [Heavy Ion Storage Ring for Atomic Physics] prototype hardware studies
International Nuclear Information System (INIS)
Olsen, D.K.; Atkins, W.H.; Dowling, D.T.; Johnson, J.W.; Lord, R.S.; McConnell, J.W.; Milner, W.T.; Mosko, S.W.; Tatum, B.A.
1989-01-01
HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 2.67-Tm synchrotron/cooler/storage ring optimized for advanced atomic physics research which will be injected with ions from either the HHIRF 25-MV tandem accelerator or a dedicated ECR source and RFQ linac. Over the last two years, hardware prototypes have been developed for difficult and long lead-time components. A vacuum test stand, the rf cavity, and a prototype dipole magnet have been designed, constructed, and tested. 7 refs., 8 figs., 2 tabs
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Polarization Insensitivity in Double-Split Ring and Triple-Split Ring Terahertz Resonators
International Nuclear Information System (INIS)
Wu Qian-Nan; Lan Feng; Tang Xiao-Pin; Yang Zi-Qiang
2015-01-01
A modified double-split ring resonator and a modified triple-split ring resonator, which offer polarization-insensitive performance, are investigated, designed and fabricated. By displacing the two gaps of the conventional double-split ring resonator away from the center, the second resonant frequency for the 0° polarized wave and the resonant frequency for the 90° polarized wave become increasingly close to each other until they are finally identical. Theoretical and experimental results show that the modified double-split ring resonator and the modified triple-split ring resonator are insensitive to different polarized waves and show strong resonant frequency dips near 433 and 444 GHz, respectively. The results of this work suggest new opportunities for the investigation and design of polarization-dependent terahertz devices based on split ring resonators. (paper)
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HYDROCARBON EMISSION RINGS IN PROTOPLANETARY DISKS INDUCED BY DUST EVOLUTION
Energy Technology Data Exchange (ETDEWEB)
Bergin, Edwin A.; Du, Fujun; Schwarz, K.; Zhang, K. [Department of Astronomy, University of Michigan, 311 West Hall, 1085 S. University Ave, Ann Arbor, MI 48109 (United States); Cleeves, L. Ilsedore [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Blake, G. A. [Division of Geological and Planetary Sciences, MC 150-21, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125 (United States); Visser, R. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748, Garching (Germany)
2016-11-01
We report observations of resolved C{sub 2}H emission rings within the gas-rich protoplanetary disks of TW Hya and DM Tau using the Atacama Large Millimeter Array. In each case the emission ring is found to arise at the edge of the observable disk of millimeter-sized grains (pebbles) traced by submillimeter-wave continuum emission. In addition, we detect a C{sub 3}H{sub 2} emission ring with an identical spatial distribution to C{sub 2}H in the TW Hya disk. This suggests that these are hydrocarbon rings (i.e., not limited to C{sub 2}H). Using a detailed thermo-chemical model we show that reproducing the emission from C{sub 2}H requires a strong UV field and C/O > 1 in the upper disk atmosphere and outer disk, beyond the edge of the pebble disk. This naturally arises in a disk where the ice-coated dust mass is spatially stratified due to the combined effects of coagulation, gravitational settling and drift. This stratification causes the disk surface and outer disk to have a greater permeability to UV photons. Furthermore the concentration of ices that transport key volatile carriers of oxygen and carbon in the midplane, along with photochemical erosion of CO, leads to an elemental C/O ratio that exceeds unity in the UV-dominated disk. Thus the motions of the grains, and not the gas, lead to a rich hydrocarbon chemistry in disk surface layers and in the outer disk midplane.
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Congenital Complete Tracheal Ring in a Neonate: A Case Report
Directory of Open Access Journals (Sweden)
Esra ARUN ÖZER
2017-09-01
Full Text Available Abnormalities of the upper airway tract lead to congenital high airway obstruction and may complicate neonatal airway management in the delivery room. Congenital complete tracheal rings are a rare and unusual tracheal anomaly, usually presenting in the neonate or infant as respiratory distress. The clinical presentation can vary from almost asymptomatic patients to near-fatal airway obstruction. It may exist as an isolated entity, or in association with other congenital malformations, in particular, cardiac anomalies along with vascular rings and pulmonary slings. Other associated anomalies have also been reported, for example, chromosomal anomalies, malformation of other parts of the respiratory tract, esophagus and skeletal systems. Here, we report an extreme case of VACTERL/TACRD association presented with congenital complete tracheal ring, encephalocele, bilateral radial agenesis with absent thumbs, equinovalgus deformity on right foot, low-set ears and micrognathia.
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RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS
Energy Technology Data Exchange (ETDEWEB)
Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)
2015-12-15
We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.
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Three-dimensional coating and rimming flow: a ring of fluid on a rotating horizontal cylinder
Leslie, G. A.
2013-01-29
The steady three-dimensional flow of a thin, slowly varying ring of Newtonian fluid on either the outside or the inside of a uniformly rotating large horizontal cylinder is investigated. Specifically, we study \\'full-ring\\' solutions, corresponding to a ring of continuous, finite and non-zero thickness that extends all of the way around the cylinder. In particular, it is found that there is a critical solution corresponding to either a critical load above which no full-ring solution exists (if the rotation speed is prescribed) or a critical rotation speed below which no full-ring solution exists (if the load is prescribed). We describe the behaviour of the critical solution and, in particular, show that the critical flux, the critical load, the critical semi-width and the critical ring profile are all increasing functions of the rotation speed. In the limit of small rotation speed, the critical flux is small and the critical ring is narrow and thin, leading to a small critical load. In the limit of large rotation speed, the critical flux is large and the critical ring is wide on the upper half of the cylinder and thick on the lower half of the cylinder, leading to a large critical load. We also describe the behaviour of the non-critical full-ring solution and, in particular, show that the semi-width and the ring profile are increasing functions of the load but, in general, non-monotonic functions of the rotation speed. In the limit of large rotation speed, the ring approaches a limiting non-uniform shape, whereas in the limit of small load, the ring is narrow and thin with a uniform parabolic profile. Finally, we show that, while for most values of the rotation speed and the load the azimuthal velocity is in the same direction as the rotation of the cylinder, there is a region of parameter space close to the critical solution for sufficiently small rotation speed in which backflow occurs in a small region on the upward-moving side of the cylinder. © 2013
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Three-dimensional coating and rimming flow: a ring of fluid on a rotating horizontal cylinder
Leslie, G. A.; Wilson, S. K.; Duffy, B. R.
2013-01-01
The steady three-dimensional flow of a thin, slowly varying ring of Newtonian fluid on either the outside or the inside of a uniformly rotating large horizontal cylinder is investigated. Specifically, we study 'full-ring' solutions, corresponding to a ring of continuous, finite and non-zero thickness that extends all of the way around the cylinder. In particular, it is found that there is a critical solution corresponding to either a critical load above which no full-ring solution exists (if the rotation speed is prescribed) or a critical rotation speed below which no full-ring solution exists (if the load is prescribed). We describe the behaviour of the critical solution and, in particular, show that the critical flux, the critical load, the critical semi-width and the critical ring profile are all increasing functions of the rotation speed. In the limit of small rotation speed, the critical flux is small and the critical ring is narrow and thin, leading to a small critical load. In the limit of large rotation speed, the critical flux is large and the critical ring is wide on the upper half of the cylinder and thick on the lower half of the cylinder, leading to a large critical load. We also describe the behaviour of the non-critical full-ring solution and, in particular, show that the semi-width and the ring profile are increasing functions of the load but, in general, non-monotonic functions of the rotation speed. In the limit of large rotation speed, the ring approaches a limiting non-uniform shape, whereas in the limit of small load, the ring is narrow and thin with a uniform parabolic profile. Finally, we show that, while for most values of the rotation speed and the load the azimuthal velocity is in the same direction as the rotation of the cylinder, there is a region of parameter space close to the critical solution for sufficiently small rotation speed in which backflow occurs in a small region on the upward-moving side of the cylinder. © 2013 Cambridge
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Howarth, Roy B.
1983-01-01
A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.
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International Nuclear Information System (INIS)
Fomin, Vladimir M.
2014-01-01
Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.
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How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?
Mäthger, Lydia M; Bell, George R R; Kuzirian, Alan M; Allen, Justine J; Hanlon, Roger T
2012-11-01
The blue-ringed octopus (Hapalochlaena lunulata), one of the world's most venomous animals, has long captivated and endangered a large audience: children playing at the beach, divers turning over rocks, and biologists researching neurotoxins. These small animals spend much of their time in hiding, showing effective camouflage patterns. When disturbed, the octopus will flash around 60 iridescent blue rings and, when strongly harassed, bite and deliver a neurotoxin that can kill a human. Here, we describe the flashing mechanism and optical properties of these rings. The rings contain physiologically inert multilayer reflectors, arranged to reflect blue-green light in a broad viewing direction. Dark pigmented chromatophores are found beneath and around each ring to enhance contrast. No chromatophores are above the ring; this is unusual for cephalopods, which typically use chromatophores to cover or spectrally modify iridescence. The fast flashes are achieved using muscles under direct neural control. The ring is hidden by contraction of muscles above the iridophores; relaxation of these muscles and contraction of muscles outside the ring expose the iridescence. This mechanism of producing iridescent signals has not previously been reported in cephalopods and we suggest that it is an exceptionally effective way to create a fast and conspicuous warning display.
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Directory of Open Access Journals (Sweden)
Areej M. Abduldaim
2013-01-01
Full Text Available As a generalization of α-skew McCoy rings, we introduce the concept of α-skew π-McCoy rings, and we study the relationships with another two new generalizations, α-skew π1-McCoy rings and α-skew π2-McCoy rings, observing the relations with α-skew McCoy rings, π-McCoy rings, α-skew Armendariz rings, π-regular rings, and other kinds of rings. Also, we investigate conditions such that α-skew π1-McCoy rings imply α-skew π-McCoy rings and α-skew π2-McCoy rings. We show that in the case where R is a nonreduced ring, if R is 2-primal, then R is an α-skew π-McCoy ring. And, let R be a weak (α,δ-compatible ring; if R is an α-skew π1-McCoy ring, then R is α-skew π2-McCoy.
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Weight training, aerobic physical activities, and long-term waist circumference change in men
DEFF Research Database (Denmark)
Mekary, Rania A; Grøntved, Anders; Despres, Jean-Pierre
2015-01-01
OBJECTIVE: Findings on weight training and waist circumference (WC) change are controversial. This study examined prospectively whether weight training, moderate to vigorous aerobic activity (MVAA), and replacement of one activity for another were associated with favorable changes in WC and body ...
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James, Lauren; Nzelu, Diane; Hay, Anna; Shennan, Andrew; Kametas, Nikos A
2017-04-01
The aim of this study was to evaluate the accuracy of the Omron MIT Elite automated device in pregnant women with an arm circumference of or above 32 cm, using the British Hypertension Society validation protocol. Blood pressure was measured sequentially in 46 women of any gestation requiring the use of a large cuff (arm circumference ≥32 cm) alternating between the mercury sphygmomanometer and the Omron MIT Elite device. The Omron MIT Elite achieved an overall D/D grade with a mean of the device-observer difference being 7.17±6.67 and 9.31±6.59 for systolic and diastolic blood pressure respectively. Interobserver accuracy was 94.6% for systolic and 95% for diastolic readings within 5 mmHg. The Omron MIT Elite overestimates blood pressure and has failed the British Hypertension Society protocol requirements. Therefore, it cannot be recommended for use in pregnant women with an arm circumference of or above 32 cm.
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Transverse Periodic Beam Loading Effects in a Storage Ring
International Nuclear Information System (INIS)
Thompson, J.R.; Byrd, J.M.
2009-01-01
Uneven beam fill patterns in storage rings, such as gaps in the fill patterns, leads to periodic, or transient loading of the modes of the RF cavities. We show that an analogous effect can occur in the loading of a dipole cavity mode when the beam passes off the electrical center of the cavity mode. Although this effect is small, it results in a variation of the transverse offset of the beam along the bunch train. For ultralow emittance beams, such as optimized third generation light sources and damping rings, this effect results in a larger projected emittance of the beam compared with the single bunch emittance. The effect is particularly strong for the case when a strong dipole mode has been purposely added to the ring, such as a deflecting, or 'crab' cavity. We derive an approximate analytic solution for the variation of the beam-induced deflecting voltage along the bunch train.
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Eddy current inspection of stationary blade rings
International Nuclear Information System (INIS)
Krzywosz, K.J.; Hastings, S.N.
1994-01-01
Stationary turbine blade rings in a US power plant have experienced chloride-induced cracking. Failure analysis determined two types of cracking mechanisms: corrosion fatigue cracking confined to the leading edge of the outer shroud; and stress corrosion cracking present all over the blade surface. Fluorescent dye penetrant is typically used to detect and size cracks. However, it requires cleaning the blade rings by sandblasting to obtain reliable inspection results. Sand blasting in turn requires sealing the lower half of the turbine housing to prevent sand from contaminating the rest of the power plant components. Furthermore, both the penetrant examination and the removal of the sand are time consuming and costly. An alternative NDE technique is desirable which requires no pre-cleaning of the blade and a quick go/no-go inspection with the capability of estimating the crack length. This paper presents an innovative eddy current technique which meets the desired objectives by incorporating the use of specially designed contoured scanners equipped with an array of pancake coils. A set of eddy current pancake coils housed in three different scanners is used to manually scan and inspect the convex side of the stationary blade rings. The pancake coils are operated in a transmit/receive mode using two separate eddy current instruments. This paper presents the inspection concept, including scanner and probe designs, and test results from the various stages of multiple blade rings
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Ozkaya, Ismail; Yardimci, Bulent; Tunckale, Aydin
2017-12-01
To investigate the association between neck circumference (NC), overweight, and metabolic syndrome (MS) in Turkish patients with type 2 diabetes. A total of 264 diabetic patients (mean age: 52.9±8.1 years) were recruited from two centers in Istanbul to perform anthropometric measurements, including waist and hip circumference, NC, and body mass index. Blood pressure, fasting glucose, and lipid profile (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglyceride levels) were determined. NC correlated with waist circumference, systolic blood pressure, and triglycerides in men, whereas NC only correlated with waist circumference in women. Additionally, NC was shown to negatively correlate with high-density lipoprotein cholesterol in both men and women. Receiver operating characteristic analysis showed that the area under the curve for NC and overweight was 0.95 for both men and women (P<0.001). Moreover, a NC of 38cm for men and 37cm for women was the best cut-off point for determining overweight. The area under the curve for NC and MS was 0.87 for men and 0.83 for women (P<0.001). A NC of 39cm for men and 37cm for women was the best cut-off point to determine participants with MS. Our findings suggest a positive correlation of NC with MetS in Turkish patients with type 2 diabetes, and could be a useful and accurate tool to identify MS. Copyright © 2017 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.
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The Electromechanical Behavior of a Micro-Ring Driven by Traveling Electrostatic Force
Ye, Xiuqian; Chen, Yibao; Chen, Da-Chih; Huang, Kuo-Yi; Hu, Yuh-Chung
2012-01-01
There is no literature mentioning the electromechanical behavior of micro structures driven by traveling electrostatic forces. This article is thus the first to present the dynamics and stabilities of a micro-ring subjected to a traveling electrostatic force. The traveling electrostatic force may be induced by sequentially actuated electrodes which are arranged around the flexible micro-ring. The analysis is based on a linearized distributed model considering the electromechanical coupling effects between electrostatic force and structure. The micro-ring will resonate when the traveling speeds of the electrostatic force approach some critical speeds. The critical speeds are equal to the ratio of the natural frequencies to the wave number of the correlative natural mode of the ring. Apart from resonance, the ring may be unstable at some unstable traveling speeds. The unstable regions appear not only near the critical speeds, but also near some fractions of some critical speeds differences. Furthermore the unstable regions expand with increasing driving voltage. This article may lead to a new research branch on electrostatic-driven micro devices. PMID:22438705
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VUV optical ring resonator for Duke storage ring free electron laser
Energy Technology Data Exchange (ETDEWEB)
Park, S.H.; Litvinenko, V.N.; Madey, J.M.J. [Duke Univ., Durham, NC (United States)] [and others
1995-12-31
The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.
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Interaction Region Design for a Ring-Ring LHeC
Thompson, L N S; Bernard, N R; Fitterer, M; Holzer, B; Klein, M; Kostka, P
2011-01-01
tively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discusse...
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Predicting waist circumference from body mass index
Directory of Open Access Journals (Sweden)
Bozeman Samuel R
2012-08-01
Full Text Available Abstract Background Being overweight or obese increases risk for cardiometabolic disorders. Although both body mass index (BMI and waist circumference (WC measure the level of overweight and obesity, WC may be more important because of its closer relationship to total body fat. Because WC is typically not assessed in clinical practice, this study sought to develop and verify a model to predict WC from BMI and demographic data, and to use the predicted WC to assess cardiometabolic risk. Methods Data were obtained from the Third National Health and Nutrition Examination Survey (NHANES and the Atherosclerosis Risk in Communities Study (ARIC. We developed linear regression models for men and women using NHANES data, fitting waist circumference as a function of BMI. For validation, those regressions were applied to ARIC data, assigning a predicted WC to each individual. We used the predicted WC to assess abdominal obesity and cardiometabolic risk. Results The model correctly classified 88.4% of NHANES subjects with respect to abdominal obesity. Median differences between actual and predicted WC were − 0.07 cm for men and 0.11 cm for women. In ARIC, the model closely estimated the observed WC (median difference: − 0.34 cm for men, +3.94 cm for women, correctly classifying 86.1% of ARIC subjects with respect to abdominal obesity and 91.5% to 99.5% as to cardiometabolic risk. The model is generalizable to Caucasian and African-American adult populations because it was constructed from data on a large, population-based sample of men and women in the United States, and then validated in a population with a larger representation of African-Americans. Conclusions The model accurately estimates WC and identifies cardiometabolic risk. It should be useful for health care practitioners and public health officials who wish to identify individuals and populations at risk for cardiometabolic disease when WC data are unavailable.
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Optical line shape of molecular rings: Influence of correlated nondiagonal disorder
International Nuclear Information System (INIS)
Barvik, I.; Warns, Ch.; Reineker, P.
2006-01-01
We investigate the optical properties of molecular rings which are generally influenced by many kinds of static disorder. Recently, Papiz suggested that quasistatic disorder, anticorrelated between neighboring transfer integrals, plays an important role. We simulate such a disorder by slow colored dichotomic Markov processes with long-time constants for the decay of their correlation functions. The colored dichotomic Markov processes leading to transfer integral fluctuations can be uncorrelated, anticorrelated or partially correlated between nearest neighboring transfer integrals in the ring. The optical line shape of the molecular ring is modeled and investigated in dependence on the parameters of the stochastic processes. Conclusions as regards the influence of the correlation on the splitting of the optical line shape, the shift of the optical absorption maximum and the width of the optical line are drawn
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Li, Yang; Barløse, Casper; Jørgensen, Julie; Carlsen, Bjørn Dreiø; Jørgensen, Karl Anker
2017-01-01
An asymmetric catalytic aza-Diels-Alder/ring-closing cascade reaction between acylhydrazones and in situ formed trienamines is presented. The reaction proceeds through a formal aza-Diels-Alder cycloaddition, followed by a ring-closing reaction forming the hemiaminal ring leading to chiral bicyclic azaheterocycles in moderate to good yield (up to 71 %), good enantio- (up to 92 % ee) and diastereoselectivity (up to >20:1 d.r.). Furthermore, transformations are presented to show the potential application of the formed product. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Uniquely Strongly Clean Group Rings
Institute of Scientific and Technical Information of China (English)
WANG XIU-LAN
2012-01-01
A ring R is called clean if every element is the sum of an idempotent and a unit,and R is called uniquely strongly clean (USC for short) if every element is uniquely the sum of an idempotent and a unit that commute.In this article,some conditions on a ring R and a group G such that RG is clean are given.It is also shown that if G is a locally finite group,then the group ring RG is USC if and only if R is USC,and G is a 2-group.The left uniquely exchange group ring,as a middle ring of the uniquely clean ring and the USC ring,does not possess this property,and so does the uniquely exchange group ring.
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Influence of ring growth rate on damage development in hot ring rolling
Wang, C.; Geijselaers, H. J.M.; Omerspahic, E.; Recina, V.; van den Boogaard, A. H.
2015-01-01
As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. In the production of hot rolled rings, defects such as porosity can sometimes be found in high alloyed steel, manufactured from ingots having macro-segregation. For
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Wanitphakdeedecha, Rungsima; Iamphonrat, Thanawan; Thanomkitti, Kanchalit; Lektrakul, Nittaya; Manuskiatti, Woraphong
2015-01-01
Cellulite is a frequent skin condition for which treatment remains a challenge. A wide variety of treatments are available but most procedures offer suboptimal clinical effect and/or delayed therapeutic outcome. Only few therapeutic options have proven efficacy in the treatment of cellulite. To determine the efficacy and the safety profiles of radiofrequency and dynamic muscle activation technology in treatment of abdominal cellulite and circumference reduction. Twenty-five females with abdominal cellulite received 6 weekly radiofrequency and dynamic muscle activation treatments. Treatment areas included the abdomen and both sides of flanks. Subjects were evaluated using standardized photographs, and measurements of body weight and abdominal circumference at baseline, before every treatment visit, and 1 week and four weeks after the final treatment. Subcutaneous tissue thickness was recorded by ultrasound at baseline and 4 weeks after completion of treatment protocol. Physicians' evaluation and patient's satisfaction of clinical improvement were also measured. All subjects completed the treatment protocol and attended every follow-up visits. There was significant abdominal circumference reduction of 2.96 and 2.52 cm at 1-, and 4-week follow-up visits (p last treatment, the average circumferential reduction was sustained. Most of the patients were rated to have 25-49% improvement at 5th treatment, and 1- and 4-week follow-up visits. Ninety-two percent of the patients were satisfied with the treatment outcome. Radiofrequency provided beneficial effects on the reduction of abdomen and cellulite appearance. The benefit of muscle activation is yet to be determined.
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Ring rotational speed trend analysis by FEM approach in a Ring Rolling process
Allegri, G.; Giorleo, L.; Ceretti, E.
2018-05-01
Ring Rolling is an advanced local incremental forming technology to fabricate directly precise seamless ring-shape parts with various dimensions and materials. In this process two different deformations occur in order to reduce the width and the height of a preform hollow ring; as results a diameter expansion is obtained. In order to guarantee a uniform deformation, the preform is forced toward the Driver Roll whose aim is to transmit the rotation to the ring. The ring rotational speed selection is fundamental because the higher is the speed the higher will be the axial symmetry of the deformation process. However, it is important to underline that the rotational speed will affect not only the final ring geometry but also the loads and energy needed to produce it. Despite this importance in industrial environment, usually, a constant value for the Driver Roll angular velocity is set so to result in a decreasing trend law for the ring rotational speed. The main risk due to this approach is not fulfilling the axial symmetric constrain (due to the diameter expansion) and to generate a high localized ring section deformation. In order to improve the knowledge about this topic in the present paper three different ring rotational speed trends (constant, linearly increasing and linearly decreasing) were investigated by FEM approach. Results were compared in terms of geometrical and dimensional analysis, loads and energies required.
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Mechanical improvement of metal reinforcement rings for a finite ring-shaped superconducting bulk
Huang, Chen-Guang; Zhou, You-He
2018-03-01
As a key technique, reinforcement of type-II superconducting bulks with metal rings can efficiently improve their mechanical properties to enhance the maximum trapped field. In this paper, we study the magnetostrictive and fracture behaviors of a finite superconducting ring bulk reinforced by three typical reinforcing structures composed of metal rings during the magnetizing process by means of the minimization of magnetic energy and the finite element method. After a field-dependent critical current density is adopted, the magnetostriction, pinning-induced stress, and crack tip stress intensity factor are calculated considering the demagnetization effects. The results show that the mechanical properties of the ring bulk are strongly dependent on the reinforcing structure and the material and geometrical parameters of the metal rings. Introducing the metal ring can significantly reduce the hoop stress, and the reduction effect by internal reinforcement is much improved relative to external reinforcement. By comparison, bilateral reinforcement seems to be the best candidate structure. Only when the metal rings have particular Young's modulus and radial thickness will they contribute to improve the mechanical properties the most. In addition, if an edge crack is pre-existing in the ring bulk, the presence of metal rings can effectively avoid crack propagation since it reduces the crack tip stress intensity factor by nearly one order of magnitude.
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Minimum stiffness criteria for ring frame stiffeners of space launch vehicles
Friedrich, Linus; Schröder, Kai-Uwe
2016-12-01
Frame stringer-stiffened shell structures show high load carrying capacity in conjunction with low structural mass and are for this reason frequently used as primary structures of aerospace applications. Due to the great number of design variables, deriving suitable stiffening configurations is a demanding task and needs to be realized using efficient analysis methods. The structural design of ring frame stringer-stiffened shells can be subdivided into two steps. One, the design of a shell section between two ring frames. Two, the structural design of the ring frames such that a general instability mode is avoided. For sizing stringer-stiffened shell sections, several methods were recently developed, but existing ring frame sizing methods are mainly based on empirical relations or on smeared models. These methods do not mandatorily lead to reliable designs and in some cases the lightweight design potential of stiffened shell structures can thus not be exploited. In this paper, the explicit physical behaviour of ring frame stiffeners of space launch vehicles at the onset of panel instability is described using mechanical substitute models. Ring frame stiffeners of a stiffened shell structure are sized applying existing methods and the method suggested in this paper. To verify the suggested method and to demonstrate its potential, geometrically non-linear finite element analyses are performed using detailed finite element models.
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LENUS (Irish Health Repository)
Neff, Karl J
2013-06-24
To construct a clinical management matrix using serial fetal abdominal circumference measurements (ACMs) that will predict normal birth weight in pregnancies complicated by gestational diabetes (GDM) and reduce unnecessary ultrasound examination in women with GDM.
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Alpha - Skew Pi - Armendariz Rings
Directory of Open Access Journals (Sweden)
Areej M Abduldaim
2018-03-01
Full Text Available In this article we introduce a new concept called Alpha-skew Pi-Armendariz rings (Alpha - S Pi - ARas a generalization of the notion of Alpha-skew Armendariz rings.Another important goal behind studying this class of rings is to employ it in order to design a modern algorithm of an identification scheme according to the evolution of using modern algebra in the applications of the field of cryptography.We investigate general properties of this concept and give examples for illustration. Furthermore, this paperstudy the relationship between this concept and some previous notions related to Alpha-skew Armendariz rings. It clearly presents that every weak Alpha-skew Armendariz ring is Alpha-skew Pi-Armendariz (Alpha-S Pi-AR. Also, thisarticle showsthat the concepts of Alpha-skew Armendariz rings and Alpha-skew Pi- Armendariz rings are equivalent in case R is 2-primal and semiprime ring.Moreover, this paper proves for a semicommutative Alpha-compatible ringR that if R[x;Alpha] is nil-Armendariz, thenR is an Alpha-S Pi-AR. In addition, if R is an Alpha - S Pi -AR, 2-primal and semiprime ring, then N(R[x;Alpha]=N(R[x;Alpha]. Finally, we look forwardthat Alpha-skew Pi-Armendariz rings (Alpha-S Pi-ARbe more effect (due to their properties in the field of cryptography than Pi-Armendariz rings, weak Armendariz rings and others.For these properties and characterizations of the introduced concept Alpha-S Pi-AR, we aspire to design a novel algorithm of an identification scheme.
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Yao, Hui; Zhang, Chao; Li, Zhi-Jian; Nie, Yi-Hang; Niu, Peng-bin
2018-05-01
We theoretically investigate the thermoelectric properties in a tunneling-coupled parallel DQD-AB ring attached to one normal and one superconducting lead. The role of the intrinsic and extrinsic parameters in improving thermoelectric properties is discussed. The peak value of figure of merit near gap edges increases with the asymmetry parameter decreasing, particularly, when asymmetry parameter is less than 0.5, the figure of merit near gap edges rapidly rises. When the interdot coupling strengh is less than the superconducting gap the thermopower spectrum presents a single-platform structure. While when the interdot coupling strengh is larger than the gap, a double-platform structure appears in thermopower spectrum. Outside the gap the peak values of figure of merit might reach the order of 102. On the basis of optimizing internal parameters the thermoelectric conversion efficiency of the device can be further improved by appropriately matching the total magnetic flux and the flux difference between two subrings.
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Mendive-Tapia, David; Perrier, Aurélie; Bearpark, Michael J; Robb, Michael A; Lasorne, Benjamin; Jacquemin, Denis
2014-09-14
The photochromic properties of diarylethenes, some of the most studied class of molecular switches, are known to be controlled by non-adiabatic decay at a conical intersection seam. Nevertheless, as their fatigue-reaction mechanism - leading to non-photochromic products - is yet to be understood, we investigate the photo-chemical formation of the so-called by-product isomer using three complementary computational methods (MMVB, CASSCF and CASPT2) on three model systems of increasing complexity. We show that for the ring-opening reaction a transition state on S1(2A) involving bond breaking of the penta-ring leads to a low energy S1(2A)/S0(1A) conical intersection seam, which lies above one of the transition states leading to the by-product isomer on the ground state. Therefore, radiationless decay and subsequent side-product formation can take place explaining the photo-degradation responsible for the by-product generation in diarylethene-type molecules. The effect of dynamic electron correlation and the possible role of inter-system crossing along the penta-ring opening coordinate are discussed as well.
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Plasma-ring, fast-opening switch
International Nuclear Information System (INIS)
Hartman, C.W.; Eddleman, J.; Hammer, J.H.
1986-01-01
The authors discuss a fast-opening switch concept based on magnetically confined plasma rings, PROS (for Plasma Ring Opening Switch). In PROS, the plasma ring, confined by Bθ /sub and B/poloidal /sub fields of a compact torus, provide a low mass, localized conduction path between coaxial electrodes. To operate the switch, driver current is passed across the electrodes through the ring, storing inductive energy in external inductance and between the electrodes on the driver side of the ring. The ring is accelerated away from the driver by the field of the driver current and passes over a load gap transferring the current to the load. The authors distinguish two configurations in PROS, straight PROS where the electrodes are coaxial cylinders, and cone PROS with conical electrodes. In straight PROS ring acceleration takes place during the inductive store period as in foil switches, but with the localized ring providing the current path. Increased performance is predicted for the cone PROS (see figure) which employs compression of the ring in the cone during the inductive store period. Here, the B/θ /sub field of the driver forces the ring towards the apex of the cone but the force is in near balance with the opposing component of the radial equilibrium force of the ring along the cone. As a result, the ring undergoes a slow, quasistatic compression limited only by resistive decay of the ring field. Slow compression allows inductive storage with low-power drivers (homopoloar, magneto cumulative generators, high C-low V capacitor banks, etc.). Near the apex of the cone, near peak compression, the ring is allowed to enter a straight coaxial section where, because of low-mass, it rapidly accelerates to high velocity and crosses the load gap
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Directory of Open Access Journals (Sweden)
Eri Ishikawa
2009-12-01
Full Text Available A28-electron reduced C2h-Mo-blue 34Ǻ outer ring diameter circular ring, [Mo142O429H10(H2O49(CH3CO25(C2H5CO2]30- (≡{Mo142(CH3CO25(C2H5CO2} comprising eight carboxylate-coordinated (with disorder {Mo2} linkers and six defect pockets in two inner rings (four and three for each, respectively, reacts with La3+ in aqueous solutions at pH 3.5 to yield a 28-electron reduced elliptical Ci-Mo-blue ring of formula [Mo134O416H20(H2O46{La(H2O5}4{La(H2O7}4{LaCl2(H2O5}2]10- (≡{Mo134La10}, isolated as the Na10[Mo134O416H20(H2O46{La(H2O5}4{La(H2O7}4{LaCl2(H2O5}2]·144 H2O Na+ salt. The elliptical structure of {Mo134La10} showing 36 and 31 Å long and short axes for the outer ring diameters is attributed to four (A-D modes of LaO9/LaO7Cl2 tricapped-trigonal-prismatic coordination (TTP geometries. Two different LaO2(H2O7 and one LaO2(H2O2Cl2 TTP geometries (as A-C modes for each of two inner rings result from the coordination of all three defect pockets of the inner ring for {Mo142(CH3CO25(C2H5CO2}, and two LaO4(H2O5 TTP geometries (as D mode result from the displacement of two (acetate/propionate-coordinated binuclear {Mo2} linkers with La3+ in each inner ring. The isothermal titration calorimetry (ITC of the ring modification from circle to ellipsoid, showing the endothermic reaction of [La3+]/[{Mo142(CH3CO25(C2H5CO2}] = 6/1 with DH = 22 kJ×mol-1, DS = 172 J×K-1×mol-1, DG = −28 kJ×mol-1, and K = 9.9 ´ 104 M-1 at 293 K, leads to the conclusion that the coordination of the defect pockets to La3+ precedes the replacement of the {Mo2} linkers with La3+. 139La- NMR spectrometry of the coordination of {Mo142(CH3CO25(C2H5CO2} ring to La3+ is also discussed.
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Fusion Rings for Quantum Groups
DEFF Research Database (Denmark)
Andersen, Henning Haahr; Stroppel, Catharina
2014-01-01
We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....
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Fusion rings and fusion ideals
DEFF Research Database (Denmark)
Andersen, Troels Bak
by the so-called fusion ideals. The fusion rings of Wess-Zumino-Witten models have been widely studied and are well understood in terms of precise combinatorial descriptions and explicit generating sets of the fusion ideals. They also appear in another, more general, setting via tilting modules for quantum......This dissertation investigates fusion rings, which are Grothendieck groups of rigid, monoidal, semisimple, abelian categories. Special interest is in rational fusion rings, i.e., fusion rings which admit a finite basis, for as commutative rings they may be presented as quotients of polynomial rings...
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Opening a spiropyran ring by way of an exciplex intermediate.
Benniston, Andrew C; Harriman, Anthony; Howell, Sarah L; Li, Peiyi; Lydon, Donocadh P
2007-02-02
A molecular dyad has been synthesized in which the main chromophore is a 1,4-diethynylated benzene residue terminated with pyrene moieties, this latter unit acting as a single chromophore. A spiropyran group has been condensed to the central phenylene ring so as to position a weak electron donor close to the pyrene unit. Illumination of the pyrene-based chromophore leads to formation of a fluorescent exciplex in polar solvents but pyrene-like fluorescence is observed in nonpolar solvents. The exciplex has a lifetime of a few nanoseconds and undergoes intersystem crossing to the pyrene-like triplet state with low efficiency. Attaching a 4-nitrobenzene group to the open end of the spiropyran unit creates a new route for decay of the exciplex whereby the triplet state of the spiropyran is formed. Nonradiative decay of this latter species results in ring opening to form the corresponding merocyanine species. Rate constants for the various steps have been obtained from time-resolved fluorescence spectroscopy carried out over a modest temperature range. Under visible light illumination, the merocyanine form reverts to the original spiropyran geometry so that the cycle is closed. Energy transfer from the pyrene chromophore to the merocyanine unit leads to an increased rate of ring closure and serves to push the steady-state composition in favor of the spiropyran form.
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Waist circumference is related to low-grade inflammation in youth
DEFF Research Database (Denmark)
Steene-Johannessen, Jostein; Kolle, Elin; Resaland, GK
2010-01-01
, insulin, triglycerides and high density lipoprotein cholesterol. Results. HW participants had elevated levels of CRP (mean difference 1.50 mg/l; 95% confidence interval [CI] 0.33 to 2.66), PAI-1 (mean difference 13.3 ng/ml; 95% CI 4.1 to 22.5) and HGF (mean difference 0.29 ng/ml; 95% CI 0.07 to 0...... circumference. CRP, HGF and PAI-1 may be related to the adverse overall metabolic risk profile observed in these children and adolescents....
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Evaluation of ring impedance of the Photon Factory storage ring
International Nuclear Information System (INIS)
Kiuchi, T.; Izawa, M.; Tokumoto, S.; Hori, Y.; Sakanaka, S.; Kobayashi, M.; Kobayakawa, H.
1992-05-01
The loss parameters of the ducts in the Photon Factory (PF) storage ring were evaluated using the wire method and the code TBCI. Both the measurement and the calculation were done for a different bunch length (σ) ranging from 23 to 80 ps. The PF ring impedance was estimated to be |Z/n|=3.2 Ω using the broadband impedance model. The major contribution to the impedance comes from the bellows and the gate valve sections. Improvements of these components will lower the ring impedance by half. (author)
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An analysis of the long-term stability of the particle dynamics in hadron storage rings
International Nuclear Information System (INIS)
Bruening, O.S.
1994-05-01
This thesis extends the stability analysis of the particle motion in a storage ring and estimates the diffusion rates well inside the dynamic aperture. The calculation of the drift and diffusion coefficients focuses on an application to the proton storage ring in HERA, where the proton beam lifetime drops considerably after the proton and electron beams are brought to collision. The analysis shows that the combined effect of slow and fast modulation frequencies leads to an increased emittance growth in the storage ring. HERA the slow frequency components are caused by ground motion in the HERA tunnel and the fast frequency components by ripples in the power supplies. The thesis provides upper limits for the modultion depths of a fast tune modulation which result in tolerable growth rates for the proton emittance. The analytically calculated drift coefficients agree numerical simulations for the particle dynamics. A comparison of the calculated drift coefficients with those measured in the HERA proton storage ring shows that the analyzed mechanism can lead to growth rates of the same order of magnitude as the ones measured during the luminosity operation in the HERA storage ring. Analytical estimates for the proton growth rates predict a high sensitivity to the particle diffusion on the frequency components of the fast fast tune modulation. This prediction was confirmed by a subsequent modulation experiment in the proton storage ring of HERA, where an external tune modulation with fast frequency components led to a drastic increase in the growth rates
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Tree Rings: Timekeepers of the Past.
Phipps, R. L.; McGowan, J.
One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…
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Self-assembled formation and transformation of In/CdZnTe(110) nano-rings into camel-humps
International Nuclear Information System (INIS)
Cohen-Taguri, G.; Ruzin, A.; Goldfarb, I.
2012-01-01
We used in situ scanning tunneling microscopy to monitor in real time the formation of nano-rings at the molecular beam epitaxially grown In/CdZnTe(110) surface, and Auger electron spectroscopy to explore the corresponding compositional changes. In-diffusion of In and segregation of Cd to the surface in course of annealing lead to a formation of elliptically distorted nano-rings, elongated along the fast [110] diffusion direction. Exacerbated diffusion anisotropy in the liquid state, at temperatures above the melting point of In, further distorts the nano-rings into a camel-hump shape.
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The Centaur Chariklo and its rings system from stellar occultations in 2017
Leiva, Rodrigo; Sicardy, Bruno; Camargo, Julio; Ortiz, Jose Luis; Berard, Diane; Desmars, Josselin; Chariklo Occultations Team; Rio Group; Lucky Star Occultation Team; Granada Occultation Team
2017-10-01
A stellar occultation in June 3, 2013 revealed the presence of a dense ring system around the Centaur object (10199) Chariklo (Braga-Ribas et al., Nature 2014). Subsequent analysis of occultation data and long-term photometric variations indicate that Chariklo's body is elongated (Leiva et al. 2017, submitted) and that the main ring exhibits significant longitudinal variations of the radial width (Bérard et al. 2017, in press). We report three multi-chord high-quality stellar occultation by Chariklo on April 9, 2017 and June 22, 2017 from Namibia, and July 23 2017 from South America. The analysis of this new data set is underway, but preliminary results are consistent with triaxial ellipsoidal models. From this analysis we will:-present refined models for the size and shape of Chariklo's main body andevaluate the heights and slopes of its topographic features.-give constraints on the longitudinal width variations of Chariklo's rings andexplore the possibility to obtain the rings apsidal precession rate.Chariklo's shape and topography have strong consequences on the dynamics of the rings through Lindblad-type resonances between mean motion of the ring particles and the spin of the main body, while the rings precession rate gives constraints on the dynamical oblateness of the main body.**Part of the research leading to these results has received funding from the European Research Council under the European Community’s H2020 (2014-2020/ ERC Grant Agreement n 669416 ”LUCKY STAR”).
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Herstein, IN
2011-01-01
S. Amitsur: Associative rings with identities.- I.N. Herstein: Topics in ring theory.- N. Jacobson: Representation theory of Jordan algebras.- I. Kaplansky: The theory of homological dimension.- D. Buchsbaum: Complexes in local ring theory.- P.H. Cohn: Two topics in ring theory.- A.W. Goldie: Non-commutative localisation.
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Directory of Open Access Journals (Sweden)
Oleksandr Makeyev
2016-06-01
Full Text Available Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1-polar electrode with n rings using the (4n + 1-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2 and quadripolar (n = 3 electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected.
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Makeyev, Oleksandr; Besio, Walter G.
2016-01-01
Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected. PMID:27294933
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The impact of exospheric neutral dynamics on ring current decay
Ilie, R.; Liemohn, M. W.; Skoug, R. M.; Funsten, H. O.; Gruntman, M.; Bailey, J. J.; Toth, G.
2015-12-01
The geocorona plays an important role in the energy budget of the Earth's inner magnetosphere since charge exchange of energetic ions with exospheric neutrals makes the exosphere act as an energy sink for ring current particles. Long-term ring current decay following a magnetic storm is mainly due to these electron transfer reactions, leading to the formation energetic neutral atoms (ENAs) that leave the ring current system on ballistic trajectories. The number of ENAs emitted from a given region of space depends on several factors, such as the energy and species of the energetic ion population in that region and the density of the neutral gas with which the ions undergo charge exchange. However, the density and structure of the exosphere are strongly dependent on changes in atmospheric temperature and density as well as charge exchange with the ions of plasmaspheric origin, which depletes the geocorona (by having a neutral removed from the system). Moreover, the radiation pressure exerted by solar far-ultraviolet photons pushes the geocoronal hydrogen away from the Earth in an anti-sunward direction to form a tail of neutral hydrogen. TWINS ENA images provide a direct measurement of these ENA losses and therefore insight into the dynamics of the ring current decay through interactions with the geocorona. We assess the influence of geocoronal neutrals on ring current formation and decay by analysis of the predicted ENA emissions using 6 different geocoronal models and simulations from the HEIDI ring current model during storm time. Comparison with TWINS ENA images shows that the location of the peak ENA enhancements is highly dependent on the distribution of geocoronal hydrogen density. We show that the neutral dynamics has a strong influence on the time evolution of the ring current populations as well as on the formation of energetic neutral atoms.
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Adiponectin and waist circumference as predictors of insulin-resistance in women.
Bonneau, Graciela A; Pedrozo, Williams R; Berg, Gabriela
2014-01-01
The initial disturbance of insulin resistance seems to focus on adipose tissue is a dynamic organ involved in many physiological and metabolic processes. Expresses and secretes a variety of active peptides, adipocytokines. To evaluate the prevalence of insulin-resistance in an healthy urban middle age population and to explore the role of adiponectin, inflammatory biomarkers (hs-CRP) and traditional cardiovascular risk factors as predictors of the insulin-resistance state. We studied of 176 participants (117 women and 59 men, 25-74 years), individuals with diabetes, hypothyroidism or hyperthyroidism, infectious disease, renal, or hepatic neoplasms and pregnant women were excluded. We evaluated glucose, insulin, adiponectin and hs-CRP. We found that 17.2% of individuals presented insulin-resistance. Correlation was found between waist circumference, body mass index, blood pressure and HOMA index (pinsulin-resistance (pinsulin-resistance in men. Besides, postmenopausal women presented higher adiponectin levels than premenopausal 7.63 (4.46-9.58) vs 5.50 (3.83-7.40) μg/ml, p=0.01. Adiponectin and waist circumference are important predictors of insulin-resistance even in healthy non-diabetic women, they may open a new opportunity to improve current risk estimation. Copyright © 2013 Diabetes India. Published by Elsevier Ltd. All rights reserved.
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Confinement and stability of crystalline beams in storage rings
International Nuclear Information System (INIS)
Haffmans, A.F.
1995-01-01
We present a fully analytical approach to the study of the confinement and stability of open-quote open-quote Crystalline Beams close-quote close-quote in storage rings, in terms of such fundamental accelerator concepts as tune shift and stopband. We consider a open-quote open-quote Crystalline Beam close-quote close-quote consisting of substrings, arranged symmetrically around the reference trajectory, and we examine the motion of a slightly perturbed test particle on one of them. Our approach quite naturally leads to the conclusion, that (a) storage rings need to be operated below the transition energy, and (b) the open-quote open-quote Crystalline Beam close-quote close-quote has the same periodicity as the storage ring. Each open-quote open-quote Crystalline Beam close-quote close-quote has an upper and lower limit of the spacing between the ions. The upper limit is determined by condition (b), and the lower limit is set by the stability of the test particle motion around the equilibrium. copyright 1995 American Institute of Physics
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DEFF Research Database (Denmark)
Larsen, Sofus C; Angquist, Lars; Ahluwalia, Tarun Veer Singh
2014-01-01
Studies indicate an effect of dietary calcium on change in body weight (BW) and waist circumference (WC), but the results are inconsistent. Furthermore, a relation could depend on genetic predisposition to obesity.......Studies indicate an effect of dietary calcium on change in body weight (BW) and waist circumference (WC), but the results are inconsistent. Furthermore, a relation could depend on genetic predisposition to obesity....
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Radar imaging of Saturn's rings
Nicholson, Philip D.; French, Richard G.; Campbell, Donald B.; Margot, Jean-Luc; Nolan, Michael C.; Black, Gregory J.; Salo, Heikki J.
2005-09-01
We present delay-Doppler images of Saturn's rings based on radar observations made at Arecibo Observatory between 1999 and 2003, at a wavelength of 12.6 cm and at ring opening angles of 20.1°⩽|B|⩽26.7°. The average radar cross-section of the A ring is ˜77% relative to that of the B ring, while a stringent upper limit of 3% is placed on the cross-section of the C ring and 9% on that of the Cassini Division. These results are consistent with those obtained by Ostro et al. [1982, Icarus 49, 367-381] from radar observations at |B|=21.4°, but provide higher resolution maps of the rings' reflectivity profile. The average cross-section of the A and B rings, normalized by their projected unblocked area, is found to have decreased from 1.25±0.31 to 0.74±0.19 as the rings have opened up, while the circular polarization ratio has increased from 0.64±0.06 to 0.77±0.06. The steep decrease in cross-section is at variance with previous radar measurements [Ostro et al., 1980, Icarus 41, 381-388], and neither this nor the polarization variations are easily understood within the framework of either classical, many-particle-thick or monolayer ring models. One possible explanation involves vertical size segregation in the rings, whereby observations at larger elevation angles which see deeper into the rings preferentially see the larger particles concentrated near the rings' mid-plane. These larger particles may be less reflective and/or rougher and thus more depolarizing than the smaller ones. Images from all four years show a strong m=2 azimuthal asymmetry in the reflectivity of the A ring, with an amplitude of ±20% and minima at longitudes of 67±4° and 247±4° from the sub-Earth point. We attribute the asymmetry to the presence of gravitational wakes in the A ring as invoked by Colombo et al. [1976, Nature 264, 344-345] to explain the similar asymmetry long seen at optical wavelengths. A simple radiative transfer model suggests that the enhancement of the azimuthal
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Study of improvement in 1st ring`s gas-seal; Top ring no gas seal seino kojo no kento
Energy Technology Data Exchange (ETDEWEB)
Ando, H; Tateishi, Y; Fujimura, K; Hitosugi, H [Nippon Piston Ring Co. Ltd., Tokyo (Japan)
1997-10-01
The authors studied the effect of an angle of 1st ring twist on the amount of blow-by concerning higher speed/higher output engines for motorcycles. As a result, the authors found the twist made the ring restrained in a ring groove of piston , and confirmed its suitable range for blow-by. By means of the developed optimization method, the authors have achieved significant reduction in blow-by at high engine speed. 1 ref., 9 figs., 2 tabs.
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Directory of Open Access Journals (Sweden)
Po-Jen Hsiao
Full Text Available Estimated glomerular filtration rate (eGFR is used for diagnosis of chronic kidney disease (CKD. The eGFR models based on serum creatinine or cystatin C are used more in clinical practice. Albuminuria and neck circumference are associated with CKD and may have correlations with eGFR.We explored the correlations and modelling formulates among various indicators such as serum creatinine, cystatin C, albuminuria, and neck circumference for eGFR.Cross-sectional study.We reviewed the records of patients with high cardiovascular risk from 2010 to 2011 in Taiwan. 24-hour urine creatinine clearance was used as the standard. We utilized a decision tree to select for variables and adopted a stepwise regression method to generate five models. Model 1 was based on only serum creatinine and was adjusted for age and gender. Model 2 added serum cystatin C, models 3 and 4 added albuminuria and neck circumference, respectively. Model 5 simultaneously added both albuminuria and neck circumference.Total 177 patients were recruited in this study. In model 1, the bias was 2.01 and its precision was 14.04. In model 2, the bias was reduced to 1.86 with a precision of 13.48. The bias of model 3 was 1.49 with a precision of 12.89, and the bias for model 4 was 1.74 with a precision of 12.97. In model 5, the bias could be lower to 1.40 with a precision of 12.53.In this study, the predicting ability of eGFR was improved after the addition of serum cystatin C compared to serum creatinine alone. The bias was more significantly reduced by the calculation of albuminuria. Furthermore, the model generated by combined albuminuria and neck circumference could provide the best eGFR predictions among these five eGFR models. Neck circumference can be investigated potentially in the further studies.
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Viscosity of ring polymer melts
Pasquino, Rossana
2013-10-15
We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.
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Viscosity of ring polymer melts
Pasquino, Rossana; Vasilakopoulos, Thodoris C.; Jeong, Youncheol; Lee, Hyojoon; Rogers, Simon A.; Sakellariou, Georgios; Allgaier, Jü rgen B.; Takano, Atsushi; Brá s, Ana Rita E; Chang, Taihyun; Gooß en, Sebastian; Pyckhout-Hintzen, Wim; Wischnewski, Andreas; Hadjichristidis, Nikolaos; Richter, Dieter R.; Rubinstein, Michael H.; Vlassopoulos, Dimitris
2013-01-01
We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.
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DEFF Research Database (Denmark)
Wahlgren, B.; Rattleff, Pernille; Høyrup, S.
State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen.......State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen....
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From coffee ring to spherulites ring of poly(ethylene oxide) film from drying droplet
Hu, Yinchun; Zhang, Xuerong; Qiu, Maibo; Wei, Yan; Zhou, Qiong; Huang, Di
2018-03-01
We discuss how the "spherulites ring" morphology and "coffee ring" profile of PEO film formed by the drying droplet at glass substrate with different heating rate. Upon increasing the heating rate of substrate, it is found that deposited PEO film from drying droplet shows the unusually observed "coffee ring" profile and "spherulites ring" morphology. The main mechanism for this phenomenon is proposed to be an enhanced Marangoni convection which is induced by the increased solute concentration gradient and reduced viscous force above 70 °C. A simple formation mechanism of the unusually observed "coffee ring" profile and "spherulites ring" morphology is proposed. These findings can be exploited to trace the center of Marangoni convection, with potential applications in designing the spherulite patterns of crystalline polymer films in ink-jet printing and self-assembly fields.
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Aizawa, Masataka; Masuda, Kento; Kawahara, Hajime; Suto, Yasushi
2018-05-01
We perform a systematic search for rings around 168 Kepler planet candidates with sufficient signal-to-noise ratios that are selected from all of the short-cadence data. We fit ringed and ringless models to their light curves and compare the fitting results to search for the signatures of planetary rings. First, we identify 29 tentative systems, for which the ringed models exhibit statistically significant improvement over the ringless models. The light curves of those systems are individually examined, but we are not able to identify any candidate that indicates evidence for rings. In turn, we find several mechanisms of false positives that would produce ringlike signals, and the null detection enables us to place upper limits on the size of the rings. Furthermore, assuming the tidal alignment between axes of the planetary rings and orbits, we conclude that the occurrence rate of rings larger than twice the planetary radius is less than 15%. Even though the majority of our targets are short-period planets, our null detection provides statistical and quantitative constraints on largely uncertain theoretical models of the origin, formation, and evolution of planetary rings.
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Cylindrical-shaped nanotube field effect transistor
Hussain, Muhammad Mustafa; Fahad, Hossain M.; Smith, Casey E.; Rojas, Jhonathan Prieto
2015-01-01
A cylindrical-shaped nanotube FET may be manufactured on silicon (Si) substrates as a ring etched into a gate stack and filled with semiconductor material. An inner gate electrode couples to a region of the gate stack inside the inner circumference of the ring. An outer gate electrode couples to a region of the gate stack outside the outer circumference of the ring. The multi-gate cylindrical-shaped nanotube FET operates in volume inversion for ring widths below 15 nanometers. The cylindrical-shaped nanotube FET demonstrates better short channel effect (SCE) mitigation and higher performance (I.sub.on/I.sub.off) than conventional transistor devices. The cylindrical-shaped nanotube FET may also be manufactured with higher yields and cheaper costs than conventional transistors.
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Cylindrical-shaped nanotube field effect transistor
Hussain, Muhammad Mustafa
2015-12-29
A cylindrical-shaped nanotube FET may be manufactured on silicon (Si) substrates as a ring etched into a gate stack and filled with semiconductor material. An inner gate electrode couples to a region of the gate stack inside the inner circumference of the ring. An outer gate electrode couples to a region of the gate stack outside the outer circumference of the ring. The multi-gate cylindrical-shaped nanotube FET operates in volume inversion for ring widths below 15 nanometers. The cylindrical-shaped nanotube FET demonstrates better short channel effect (SCE) mitigation and higher performance (I.sub.on/I.sub.off) than conventional transistor devices. The cylindrical-shaped nanotube FET may also be manufactured with higher yields and cheaper costs than conventional transistors.
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Ramot, Yuval; Rousselle, Serge D; Yellin, Nadav; Willenz, Udi; Sabag, Itai; Avner, Avi; Nyska, Abraham
2016-07-01
Prosthetic annuloplasty rings are a common treatment modality for mitral regurgitation, and recently, percutaneous implantation techniques have gained popularity due to their favorable safety profile. Although in common use, biocompatibility of annuloplasty rings has been reported only sparsely in the literature, and none of these reports used the percutaneous technique of implantation. We report on the biocompatibility and the systemic safety of a novel transcatheter mitral valve annuloplasty ring (AMEND™) in 6 minipigs. This device is composed of a nitinol tube surrounded by a braided polyethylene terephthalate fabric tube. The device produced no adverse inflammatory response, showing gradual integration between the metal ring and the fabric by normal host fibrocellular response, leading to complete neoendocardium coverage. There was no evidence for adverse reactions, rejection, or intolerance in the valvular structure. In 2 animals, hemopericardium resulted from the implantation procedure, leading to right-sided cardiac insufficiency with pulmonary edema and liver congestion. The findings reported herein can serve as a case study for the expected healing pathology reactions after implantation of transcatheter mitral valve annuloplasty rings. © The Author(s) 2016.
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Structure and dynamics of ringed galaxies
International Nuclear Information System (INIS)
Buta, R.J.
1984-01-01
In many spiral and SO galaxies, single or multiple ring structures are visible in the disk. These inner rings (r), outer rings (R), and nuclear rings (nr) were investigated by means of morphology, photometry, and spectroscopy in order to provide basic data on a long neglected phenomenon. The metric properties of each ring are investigated and found to correlate with the structure of the parent galaxy. When properly calibrated, inner rings in barred (SB) systems can be used as geometric extragalactic distance indicators to distances in excess of 100 Mpc. Other statistics are presented that confirm previous indications that the rings have preferred shapes, relative sizes, and orientations with respect to bars. A survey is made of the less homogeneous non-barred (SA) ringed systems, and the causes of the inhomogeneity are isolated. It is shown that rings can be identified in multiple-ring SA systems that are exactly analogous to those in barred spirals
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Directory of Open Access Journals (Sweden)
Salima TALEB
2015-12-01
Full Text Available Introduction. Obesity evaluated by body mass index (BMI is a recognized cardiovascular risk factor. Studies have shown that adipose tissue deposition in visceral level, reflected by increased waist circumference itself was a cardiometabolic risk factor. Objective. The relationship was studied between a high waist circumference and a cardiovascular risk. Material and Methods. A descriptive and analytical cross-sectional survey was conducted among 200 subjects in 2014 in Tebessa. The questionnaire allowed us to gather the following information: anthropometric measurements, dietary habits, physical activity, smoking, personal and family history ... Blood sample was realized to determine some biochemical parameters. Results. In this study, 60.5% of the subjects had a pathological waist, women were more affected than men (72.86% vs 31.67%, p <0.0001. This prevalence peaked between 47-66 years (p <0.0001. Pathological waist circumference was a predictor of cardiovascular disease (CVD, (RR = 1.71, P = 0.028. This study revealed that 16.53% of subjects with a pathologicalwaistlines had diabetes, 55.5% were hypertensive, 49% had hypertriglyceridemia, 46% low HDL, and 18 % high LDL. In normal weight subjects, 22% had pathological waistline. Conclusion. The prevalence of abdominal obesity is higher among patients consulting in private practice in Tébessa, this requires screening and awareness of people with pathological waistline.
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The Ring of Five follows the traces
International Nuclear Information System (INIS)
Anon.
2015-01-01
The Ring of Five is an informal network of European experts in radioactivity detection belonging to public bodies such as the IRSN. After having evoked different cases of detection (detection of unusual traces of iodine 131 in the region of Stockholm in 2015, detection of high levels of traces of caesium 137 in Switzerland in 1968) which leaded to the identification of the origin of these traces, this article briefly recalls the history of the creation of this network which extended with the occurrence of the Chernobyl accident, describes how the information is transmitted, the use of modelling tools, and outlines that the detection of some species can be associated either to a nuclear accident or to an atmospheric nuclear bomb test, and indicates how new sensors, not sensitive to humidity, have been developed after a lack of detection of iodine 131. In a brief interview, the future of the Ring of Five, topics to be studied and current projects are briefly evoked
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Directory of Open Access Journals (Sweden)
Hajime Matsui
2017-12-01
Full Text Available In this study, we consider codes over Euclidean domains modulo their ideals. In the first half of the study, we deal with arbitrary Euclidean domains. We show that the product of generator matrices of codes over the rings mod a and mod b produces generator matrices of all codes over the ring mod a b , i.e., this correspondence is onto. Moreover, we show that if a and b are coprime, then this correspondence is one-to-one, i.e., there exist unique codes over the rings mod a and mod b that produce any given code over the ring mod a b through the product of their generator matrices. In the second half of the study, we focus on the typical Euclidean domains such as the rational integer ring, one-variable polynomial rings, rings of Gaussian and Eisenstein integers, p-adic integer rings and rings of one-variable formal power series. We define the reduced generator matrices of codes over Euclidean domains modulo their ideals and show their uniqueness. Finally, we apply our theory of reduced generator matrices to the Hecke rings of matrices over these Euclidean domains.
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Binomial Rings: Axiomatisation, Transfer and Classification
Xantcha, Qimh Richey
2011-01-01
Hall's binomial rings, rings with binomial coefficients, are given an axiomatisation and proved identical to the numerical rings studied by Ekedahl. The Binomial Transfer Principle is established, enabling combinatorial proofs of algebraical identities. The finitely generated binomial rings are completely classified. An application to modules over binomial rings is given.
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AN N-BODY INTEGRATOR FOR GRAVITATING PLANETARY RINGS, AND THE OUTER EDGE OF SATURN'S B RING
International Nuclear Information System (INIS)
Hahn, Joseph M.; Spitale, Joseph N.
2013-01-01
A new symplectic N-body integrator is introduced, one designed to calculate the global 360° evolution of a self-gravitating planetary ring that is in orbit about an oblate planet. This freely available code is called epi i nt, and it is distinct from other such codes in its use of streamlines to calculate the effects of ring self-gravity. The great advantage of this approach is that the perturbing forces arise from smooth wires of ring matter rather than discreet particles, so there is very little gravitational scattering and so only a modest number of particles are needed to simulate, say, the scalloped edge of a resonantly confined ring or the propagation of spiral density waves. The code is applied to the outer edge of Saturn's B ring, and a comparison of Cassini measurements of the ring's forced response to simulations of Mimas's resonant perturbations reveals that the B ring's surface density at its outer edge is σ 0 = 195 ± 60 g cm –2 , which, if the same everywhere across the ring, would mean that the B ring's mass is about 90% of Mimas's mass. Cassini observations show that the B ring-edge has several free normal modes, which are long-lived disturbances of the ring-edge that are not driven by any known satellite resonances. Although the mechanism that excites or sustains these normal modes is unknown, we can plant such a disturbance at a simulated ring's edge and find that these modes persist without any damping for more than ∼10 5 orbits or ∼100 yr despite the simulated ring's viscosity ν s = 100 cm 2 s –1 . These simulations also indicate that impulsive disturbances at a ring can excite long-lived normal modes, which suggests that an impact in the recent past by perhaps a cloud of cometary debris might have excited these disturbances, which are quite common to many of Saturn's sharp-edged rings
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Intake of ruminant trans fatty acids and changes in body weight and waist circumference
DEFF Research Database (Denmark)
Hansen, Carsten Palnæs; Berentzen, T L; Halkjær, Jytte
2012-01-01
Follow-up studies have suggested that total intake of trans fatty acids (TFA) is a risk factor for gain in body weight and waist circumference (WC). However, in a cross-sectional study individual TFA isomers in adipose tissue had divergent associations with anthropometry. Our objective...
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Buta, Ronald J.
2017-11-01
Rings are important and characteristic features of disc-shaped galaxies. This paper is the first in a series that re-visits galactic rings with the goals of further understanding the nature of the features and for examining their role in the secular evolution of galaxy structure. The series begins with a new sample of 3962 galaxies drawn from the Galaxy Zoo 2 citizen science data base, selected because zoo volunteers recognized a ring-shaped pattern in the morphology as seen in Sloan Digital Sky Survey colour images. The galaxies are classified within the framework of the Comprehensive de Vaucouleurs revised Hubble-Sandage system. It is found that zoo volunteers cued on the same kinds of ring-like features that were recognized in the 1995 Catalogue of Southern Ringed Galaxies. This paper presents the full catalogue of morphological classifications, comparisons with other sources of classifications and some histograms designed mainly to highlight the content of the catalogue. The advantages of the sample are its large size and the generally good quality of the images; the main disadvantage is the low physical resolution that limits the detectability of linearly small rings such as nuclear rings. The catalogue includes mainly inner and outer disc rings and lenses. Cataclysmic (`encounter-driven') rings (such as ring and polar ring galaxies) are recognized in less than 1 per cent of the sample.
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Novel manifestations of the Aharonov-Bohm effect in quantum rings and Moebius rings
International Nuclear Information System (INIS)
Fomin, Vladimir M.
2013-01-01
- An overview is given on the recent experimental and theoretical advancements in studies of novel manifestations of the Aharonov-Bohm quantum-interference effect for excitons confined to self assembled quantum rings and other semiconductor nanostructures with ring-like states of charge carriers as well as for electrons in Moebius rings at the micro- and nanoscale. The exciton Aharonov-Bohm effect can be effectively controlled by an out-of-plane magnetic field, a vertical electric field, a spin disorder. A 'delocalization-to-localization' transition for the electron ground state occurs in a Moebius ring as it is made more inhomogeneous. (authors)
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Ring closure in actin polymers
Energy Technology Data Exchange (ETDEWEB)
Sinha, Supurna, E-mail: supurna@rri.res.in [Raman Research Institute, Bangalore 560080 (India); Chattopadhyay, Sebanti [Doon University, Dehradun 248001 (India)
2017-03-18
We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers. - Highlights: • Ring closure of biopolymers. • Worm like chain model. • Predictions for experiments.
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On P-coherent endomorphism rings
Indian Academy of Sciences (India)
A ring is called right -coherent if every principal right ideal is finitely presented. Let M R be a right -module. We study the -coherence of the endomorphism ring of M R . It is shown that is a right -coherent ring if and only if every endomorphism of M R has a pseudokernel in add M R ; S is a left -coherent ring if and ...
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Directory of Open Access Journals (Sweden)
Rafael de Oliveira Alvim
Full Text Available The use of the anthropometric indices of adiposity, especially body mass index and waist circumference in the prediction of diabetes mellitus has been widely explored. Recently, a new body composition index, the body adiposity index was proposed. The aim of this study was to compare the effectiveness of body mass index, waist circumference, and body adiposity index in the risk assessment for type 2 diabetes mellitus.A total of 1,572 individuals from the general population of Vitoria City, Brazil and 620 Amerindians from the Aracruz Indian Reserve, Brazil were randomly selected. BMI, waist circumference, and BAI were determined according to a standard protocol. Type 2 diabetes mellitus was diagnosed by the presence of fasting glucose ≥126 mg/dL or by the use of antidiabetic drugs.The area under the curve was similar for all anthropometric indices tested in the Amerindian population, but with very different sensitivities or specificities. In women from the general population, the area under the curve of waist circumference was significantly higher than that of the body adiposity index. Regarding risk assessment for type 2 diabetes mellitus, the body adiposity index was a better risk predictor than body mass index and waist circumference in the Amerindian population and was the index with highest odds ratio for type 2 diabetes mellitus in men from the general population, while in women from the general population waist circumference was the best risk predictor.Body adiposity index was the best risk predictor for type 2 diabetes mellitus in the Amerindian population and men from the general population. Our data suggest that the body adiposity index is a useful tool for the risk assessment of type 2 diabetes mellitus in admixture populations.
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Dickmann, M
2015-01-01
In this monograph the authors extend the classical algebraic theory of quadratic forms over fields to diagonal quadratic forms with invertible entries over broad classes of commutative, unitary rings where -1 is not a sum of squares and 2 is invertible. They accomplish this by: (1) Extending the classical notion of matrix isometry of forms to a suitable notion of T-isometry, where T is a preorder of the given ring, A, or T = A^2. (2) Introducing in this context three axioms expressing simple properties of (value) representation of elements of the ring by quadratic forms, well-known to hold in
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Double Rashba Quantum Dots Ring as a Spin Filter
Directory of Open Access Journals (Sweden)
Chi Feng
2008-01-01
Full Text Available AbstractWe theoretically propose a double quantum dots (QDs ring to filter the electron spin that works due to the Rashba spin–orbit interaction (RSOI existing inside the QDs, the spin-dependent inter-dot tunneling coupling and the magnetic flux penetrating through the ring. By varying the RSOI-induced phase factor, the magnetic flux and the strength of the spin-dependent inter-dot tunneling coupling, which arises from a constant magnetic field applied on the tunneling junction between the QDs, a 100% spin-polarized conductance can be obtained. We show that both the spin orientations and the magnitude of it can be controlled by adjusting the above-mentioned parameters. The spin filtering effect is robust even in the presence of strong intra-dot Coulomb interactions and arbitrary dot-lead coupling configurations.
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Energy Technology Data Exchange (ETDEWEB)
Anon.
1993-06-15
Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)
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Elavarasan, Ramasamy; Arakeri, Jayawant; Krothapalli, Anjaneyulu
1999-11-01
The interaction of a high-speed vortex ring with a shock wave is one of the fundamental issues as it is a source of sound in supersonic jets. The complex flow field induced by the vortex alters the propagation of the shock wave greatly. In order to understand the process, a compressible vortex ring is studied in detail using Particle Image Velocimetry (PIV) and shadowgraphic techniques. The high-speed vortex ring is generated from a shock tube and the shock wave, which precedes the vortex, is reflected back by a plate and made to interact with the vortex. The shadowgraph images indicate that the reflected shock front is influenced by the non-uniform flow induced by the vortex and is decelerated while passing through the vortex. It appears that after the interaction the shock is "split" into two. The PIV measurements provided clear picture about the evolution of the vortex at different time interval. The centerline velocity traces show the maximum velocity to be around 350 m/s. The velocity field, unlike in incompressible rings, contains contributions from both the shock and the vortex ring. The velocity distribution across the vortex core, core diameter and circulation are also calculated from the PIV data.
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International Nuclear Information System (INIS)
Anon.
1993-01-01
Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)
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Accidental ingestion of BiTine ring and a note on inefficient ring separation forceps
Directory of Open Access Journals (Sweden)
Baghele ON
2011-05-01
Full Text Available Om Nemichand Baghele1, Mangala Om Baghele21Department of Periodontology, SMBT Dental College and Hospital, Sangamner, Ahmednagar, Maharashtra, India; 2Private General Dental Practice, Mumbai, IndiaBackground: Accidental ingestion of medium-to-large instruments is relatively uncommon during dental treatment but can be potentially dangerous. A case of BiTine ring ingestion is presented with a note on inefficient ring separation forceps.Case description: A 28-year-old male patient accidentally ingested the BiTine ring (2 cm diameter, 0.5 cm outward projections while it was being applied to a distoproximal cavity in tooth # 19. The ring placement forceps were excessively flexible; bending of the beaks towards the ring combined with a poor no-slippage mechanism led to sudden disengagement of the ring and accelerated movement towards the pharynx. We followed the patient with bulk forming agents and radiographs. Fortunately the ring passed out without any complications.Clinical implications: Checking equipment and methods is as important as taking precautions against any preventable medical emergency. It is the responsibility of the clinician to check, verify and then use any instrument/equipment.Keywords: foreign bodies/radiography, foreign bodies/complications, equipment failure, dental instrument, accidental ingestion
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BMI, waist circumference at 8 and 12 years of age and FVC and FEV
M.B.M. Bekkers (Marga); A.H. Wijga (Alet); U. Gehring (Ulrike); G.H. Koppelman (Gerard); J.C. de Jongste (Johan); H.A. Smit (Henriëtte); B. Brunekreef (Bert)
2015-01-01
textabstractBackground: In adults, overweight is associated with reduced lung function, in children evidence on this association is conflicting. We examined the association of body mass index (BMI) and waist circumference (WC) at age 12, and of persistently (at ages 8 and 12 years) high BMI and
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Jowett, John M; Zimmermann, Frank; Owen, H
2001-01-01
The Compact Linear Colider (CLIC) is designed to operate at 3 TeV centre-of-mass energy with a total luminosity of 10^35 cm^-2 s^-1. The overall system design leads to extremely demanding requirements on the bunch trains injected into the main libac at frequency of 100 Hz. In particular, the emittances of the intense bunches have to be about an order of magnitude smaller than presently achieved. We describe our approach to finding a damping ring design capable of meeting these requirements. Besides lattice design, emittance and damping rate considerations, a number of scattering and instability effects have to be incorporated into the optimisation of parameters. Among these, intra-bem scattering and the electron cloud effect are two of the most significant.
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Abonyi, Obinna Everistus; Eze, Charles Ugwoke; Onwuzu, Sobechukwu W I
2017-11-01
The purpose of this study was to create a reference range nomogram of foetal neck circumference (FNC) and foetal neck area (FNA) in a Nigerian population using polynomial regression models. This cross-sectional study involved 723 pregnant women between 14 and 40 weeks of gestation. Axial measurements of the FNC and FNA were obtained in three measurements and the mean taken as the final value and the 5th, 50th and 95th percentiles for each foetal gestational age (FGA) were calculated. FNC and FNA correlated strongly with FGA, biparietal diameter, abdominal circumference, head circumference, and femoral length. Cubic models fitted the FNC vs FGA, and FNA vs. FGA values, and the mathematical relationships are given as: [Formula: see text] [Formula: see text] [Formula: see text]. Nomograms of FNC and FNA are thus generated. Impact statement The foetal neck circumference (FNC) and foetal neck area (FNA) can serve as predictors of foetal gestational age (FGA) since they correlate strongly and positively with FGA and known biometric parameters. The measurements obtained vary with the population studied. This study provides a nomogram of the FNA and FNC for an African population. The values correlate with that of the Caucasian population up to 32 weeks FGA. Interestingly, FNA and FNC measurements demonstrate high correlation but poor agreement in measurements between sonographers. Even though FNA and FNC could be used as predictors of foetal gestational age, the measurements vary significantly between sonographers. This is attributable to the difficulty in obtaining a satisfactory axial view of foetal neck, which is dependent on foetal presentation.
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On the Laurent polynomial rings
International Nuclear Information System (INIS)
Stefanescu, D.
1985-02-01
We describe some properties of the Laurent polynomial rings in a finite number of indeterminates over a commutative unitary ring. We study some subrings of the Laurent polynomial rings. We finally obtain two cancellation properties. (author)
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DEFF Research Database (Denmark)
Galili, Michael; Kamchevska, Valerija; Ding, Yunhong
2016-01-01
We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization......We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization...
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International Nuclear Information System (INIS)
Uckan, N.A.
1980-04-01
This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers
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Four faces of the interaction between ions and aromatic rings.
Papp, Dóra; Rovó, Petra; Jákli, Imre; Császár, Attila G; Perczel, András
2017-07-15
Non-covalent interactions between ions and aromatic rings play an important role in the stabilization of macromolecular complexes; of particular interest are peptides and proteins containing aromatic side chains (Phe, Trp, and Tyr) interacting with negatively (Asp and Glu) and positively (Arg and Lys) charged amino acid residues. The structures of the ion-aromatic-ring complexes are the result of an interaction between the large quadrupole moment of the ring and the charge of the ion. Four attractive interaction types are proposed to be distinguished based on the position of the ion with respect to the plane of the ring: perpendicular cation-π (CP ⊥ ), co-planar cation-π (CP ∥ ), perpendicular anion-π (AP ⊥ ), and co-planar anion-π (AP ∥ ). To understand more than the basic features of these four interaction types, a systematic, high-level quantum chemical study is performed, using the X - + C 6 H 6 , M + + C 6 H 6 , X - + C 6 F 6 , and M + + C 6 F 6 model systems with X - = H - , F - , Cl - , HCOO - , CH 3 COO - and M + = H + , Li + , Na + , NH4+, CH 3 NH3+, whereby C 6 H 6 and C 6 F 6 represent an electron-rich and an electron-deficient π system, respectively. Benchmark-quality interaction energies with small uncertainties, obtained via the so-called focal-point analysis (FPA) technique, are reported for the four interaction types. The computations reveal that the interactions lead to significant stabilization, and that the interaction energy order, given in kcal mol -1 in parentheses, is CP ⊥ (23-37) > AP ⊥ (14-21) > CP ∥ (9-22) > AP ∥ (6-16). A natural bond orbital analysis performed leads to a deeper qualitative understanding of the four interaction types. To facilitate the future quantum chemical characterization of ion-aromatic-ring interactions in large biomolecules, the performance of three density functional theory methods, B3LYP, BHandHLYP, and M06-2X, is tested against the FPA benchmarks
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Prince, Martin; Acosta, Daisy; Dangour, Alan D; Uauy, Ricardo; Guerra, Mariella; Huang, Yueqin; Jacob, KS; Llibre Rodriguez, Juan J.; Salas, Aquiles; Sosa, Ana Luisa; Williams, Joseph D.; Acosta, Isaac; Albanese, Emiliano; Dewey, Michael E.; Ferri, Cleusa P.; Stewart, Robert; Gaona, Ciro; Jotheeswaran, AT.; Senthil Kumar, P; Li, Shuran; Llibre Guerra, Juan C.; Rodriguez, Diana; Rodriguez, Guillermina
2017-01-01
Background Adult leg length is influenced by nutrition in the first few years of life. Adult head circumference is an indicator of brain growth. There is a limited literature linking short legs and small skulls to an increased risk for cognitive impairment and dementia in late life. Methods One phase cross-sectional surveys of all over 65 year old residents (n=14,960) in 11 catchment areas in China, India, Cuba, Dominican Republic, Venezuela, Mexico and Peru. The cross-culturally validated 10/66 dementia diagnosis, and a sociodemographic and risk factor questionnaire were administered to all participants, and anthropometric measures taken. Poisson regression was used to calculate prevalence ratios for the effect of leg length and skull circumference upon 10/66 Dementia, controlling for age, gender, education and family history of dementia. Results The pooled meta-analysed fixed effect for leg length (highest vs. lowest quarter) was 0.82 (95% CI, 0.68-0.98) and for skull circumference 0.75 (95% CI, 0.63-0.89). While point estimates varied between sites, the proportion of the variability attributable to heterogeneity between studies as opposed to sampling error (I2) was 0% for leg length and 22% for skull circumference. The effects were independent and not mediated by family history of dementia. The effect of skull circumference was not modified by educational level or gender, and the effect of leg length was not modified by gender. Conclusions Since leg length and skull circumference are said to remain stable throughout adulthood into old age, reverse causality is an unlikely explanation for the findings. Early life nutritional programming, as well as neurodevelopment may protect against neurodegeneration. PMID:20701817
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Prince, Martin; Acosta, Daisy; Dangour, Alan D; Uauy, Ricardo; Guerra, Mariella; Huang, Yueqin; Jacob, K S; Rodriguez, Juan J Llibre; Salas, Aquiles; Sosa, Ana Luisa; Williams, Joseph D; Acosta, Isaac; Albanese, Emiliano; Dewey, Michael E; Ferri, Cleusa P; Stewart, Robert; Gaona, Ciro; Jotheeswaran, A T; Kumar, P Senthil; Li, Shuran; Guerra, Juan C Llibre; Rodriguez, Diana; Rodriguez, Guillermina
2011-03-01
Adult leg length is influenced by nutrition in the first few years of life. Adult head circumference is an indicator of brain growth. There is a limited literature linking short legs and small skulls to an increased risk for cognitive impairment and dementia in late life. One phase cross-sectional surveys were carried out of all residents aged over 65 years in 11 catchment areas in China, India, Cuba, Dominican Republic, Venezuela, Mexico and Peru (n = 14,960). The cross-culturally validated 10/66 dementia diagnosis, and a sociodemographic and risk factor questionnaire were administered to all participants, and anthropometric measures taken. Poisson regression was used to calculate prevalence ratios for the effect of leg length and skull circumference upon 10/66 dementia, controlling for age, gender, education and family history of dementia. The pooled meta-analyzed fixed effect for leg length (highest vs. lowest quarter) was 0.82 (95% CI, 0.68-0.98) and for skull circumference 0.75 (95% CI, 0.63-0.89). While point estimates varied between sites, the proportion of the variability attributable to heterogeneity between studies as opposed to sampling error (I2) was 0% for leg length and 22% for skull circumference. The effects were independent and not mediated by family history of dementia. The effect of skull circumference was not modified by educational level or gender, and the effect of leg length was not modified by gender. Since leg length and skull circumference are said to remain stable throughout adulthood into old age, reverse causality is an unlikely explanation for the findings. Early life nutritional programming, as well as neurodevelopment may protect against neurodegeneration.
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International Nuclear Information System (INIS)
Sunikumar, Nikita
2011-01-01
Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.
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Photon-induced tunability of the thermospin current in a Rashba ring
Abdullah, Nzar Rauf; Arnold, Thorsten; Tang, Chi-Shung; Manolescu, Andrei; Gudmundsson, Vidar
2018-04-01
The goal of this work is to show how the thermospin polarization current in a quantum ring changes in the presence of Rashba spin-orbit coupling and a quantized single photon mode of a cavity the ring is placed in. Employing the reduced density operator and a general master equation formalism, we find that both the Rashba interaction and the photon field can significantly modulate the spin polarization and the thermospin polarization current. Tuning the Rashba coupling constant, degenerate energy levels are formed corresponding to the Aharonov-Casher destructive phase interference in the quantum ring system. Our analysis indicates that the maximum spin polarization can be observed at the points of degenerate energy levels due to spin accumulation in the system without the photon field. The thermospin current is thus suppressed. In the presence of the cavity, the photon field leads to an additional kinetic momentum of the electron. As a result the spin polarization can be enhanced by the photon field.
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Asymmetric ring structure of Vps4 required for ESCRT-III disassembly
Caillat, Christophe; Macheboeuf, Pauline; Wu, Yuanfei; McCarthy, Andrew A.; Boeri-Erba, Elisabetta; Effantin, Gregory; Göttlinger, Heinrich G.; Weissenhorn, Winfried; Renesto, Patricia
2015-12-01
The vacuolar protein sorting 4 AAA-ATPase (Vps4) recycles endosomal sorting complexes required for transport (ESCRT-III) polymers from cellular membranes. Here we present a 3.6-Å X-ray structure of ring-shaped Vps4 from Metallosphera sedula (MsVps4), seen as an asymmetric pseudohexamer. Conserved key interface residues are shown to be important for MsVps4 assembly, ATPase activity in vitro, ESCRT-III disassembly in vitro and HIV-1 budding. ADP binding leads to conformational changes within the protomer, which might propagate within the ring structure. All ATP-binding sites are accessible and the pseudohexamer binds six ATP with micromolar affinity in vitro. In contrast, ADP occupies one high-affinity and five low-affinity binding sites in vitro, consistent with conformational asymmetry induced on ATP hydrolysis. The structure represents a snapshot of an assembled Vps4 conformation and provides insight into the molecular motions the ring structure undergoes in a concerted action to couple ATP hydrolysis to ESCRT-III substrate disassembly.
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Chiral rings and anomalies in supersymmetric gauge theory
International Nuclear Information System (INIS)
Cachazo, Freddy; Witten, Edward; Seiberg, Nathan; Douglas, Michael R.
2002-01-01
Motivated by recent work of Dijkgraaf and Vafa, we study anomalies and the chiral ring structure in a supersymmetric U(N) gauge theory with an adjoint chiral superfield and an arbitrary superpotential. A certain generalization of the Konishi anomaly leads to an equation which is identical to the loop equation of a bosonic matrix model. This allows us to solve for the expectation values of the chiral operators as functions of a finite number of 'integration constants'. From this, we can derive the Dijkgraaf-Vafa relation of the effective superpotential to a matrix model. Some of our results are applicable to more general theories. For example, we determine the classical relations and quantum deformations of the chiral ring of N=1 super Yang-Mills theory with SU(N) gauge group, showing, as one consequence, that all supersymmetric vacua of this theory have a nonzero chiral condensate. (author)
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International Nuclear Information System (INIS)
De-An, Pan; Shen-Gen, Zhang; Jian-Jun, Tian; Li-Jie, Qiao; Jun-Sai, Sun; Volinsky, Alex A.
2010-01-01
Current–voltage measurements obtained from lead zirconate titanate/nickel bilayered hollow cylindrical magnetoelectric composite showed that a sinusoidal current applied to the copper coil wrapped around the hollow cylinder circumference induces voltage across the lead zirconate titanate layer thickness. The current–voltage coefficient and the maximum induced voltage in lead zirconate titanate at 1 kHz and resonance (60.1 kHz) frequencies increased linearly with the number of the coil turns and the applied current. The resonance frequency corresponds to the electromechanical resonance frequency. The current–voltage coefficient can be significantly improved by optimizing the magnetoelectric structure geometry and/or increasing the number of coil turns. Hollow cylindrical lead zirconate titanate/nickel structures can be potentially used as current sensors. (condensed matter: electronic structure, electrical, magnetic, and optical properties)
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Cell-autonomous correction of ring chromosomes in human induced pluripotent stem cells
Bershteyn, Marina; Hayashi, Yohei; Desachy, Guillaume; Hsiao, Edward C.; Sami, Salma; Tsang, Kathryn M.; Weiss, Lauren A.; Kriegstein, Arnold R.; Yamanaka, Shinya; Wynshaw-Boris, Anthony
2014-03-01
Ring chromosomes are structural aberrations commonly associated with birth defects, mental disabilities and growth retardation. Rings form after fusion of the long and short arms of a chromosome, and are sometimes associated with large terminal deletions. Owing to the severity of these large aberrations that can affect multiple contiguous genes, no possible therapeutic strategies for ring chromosome disorders have been proposed. During cell division, ring chromosomes can exhibit unstable behaviour leading to continuous production of aneuploid progeny with low viability and high cellular death rate. The overall consequences of this chromosomal instability have been largely unexplored in experimental model systems. Here we generated human induced pluripotent stem cells (iPSCs) from patient fibroblasts containing ring chromosomes with large deletions and found that reprogrammed cells lost the abnormal chromosome and duplicated the wild-type homologue through the compensatory uniparental disomy (UPD) mechanism. The karyotypically normal iPSCs with isodisomy for the corrected chromosome outgrew co-existing aneuploid populations, enabling rapid and efficient isolation of patient-derived iPSCs devoid of the original chromosomal aberration. Our results suggest a fundamentally different function for cellular reprogramming as a means of `chromosome therapy' to reverse combined loss-of-function across many genes in cells with large-scale aberrations involving ring structures. In addition, our work provides an experimentally tractable human cellular system for studying mechanisms of chromosomal number control, which is of critical relevance to human development and disease.
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2013-01-01
Please note this is a Short Discount publication. This report provides an overview of the IBM Token-Ring technology and products built by IBM and compatible vendors. It consists of two sections: 1. A summary of the design trade-offs for the IBM Token-Ring. 2. A summary of the products of the major token-ring compatible vendors broken down by adapters and components, wiring systems, testing, and new chip technology.
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BMI, waist circumference at 8 and 12 years of age and FVC and FEV
Bekkers, Marga B.; Wijga, Alet H.; Gehring, Ulrike; Koppelman, Gerard H.; de Jongste, Johan C.; Smit, Henriette A.; Brunekreef, Bert
2015-01-01
Background: In adults, overweight is associated with reduced lung function, in children evidence on this association is conflicting. We examined the association of body mass index (BMI) and waist circumference (WC) at age 12, and of persistently (at ages 8 and 12 years) high BMI and large WC, with
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International Nuclear Information System (INIS)
Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.
1982-01-01
We have completed a design of the Prototype Moving-Ring Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma (Compact Toroids). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three burn stations. Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for 1/3 of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power
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Polycomb Group Proteins RING1A and RING1B Regulate the Vegetative Phase Transition in Arabidopsis
Directory of Open Access Journals (Sweden)
Jian Li
2017-05-01
Full Text Available Polycomb group (PcG protein-mediated gene silencing is a major regulatory mechanism in higher eukaryotes that affects gene expression at the transcriptional level. Here, we report that two conserved homologous PcG proteins, RING1A and RING1B (RING1A/B, are required for global H2A monoubiquitination (H2Aub in Arabidopsis. The mutation of RING1A/B increased the expression of members of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL gene family and caused an early vegetative phase transition. The early vegetative phase transition observed in ring1a ring1b double mutant plants was dependent on an SPL family gene, and the H2Aub status of the chromatin at SPL locus was dependent on RING1A/B. Moreover, mutation in RING1A/B affected the miRNA156a-mediated vegetative phase transition, and RING1A/B and the AGO7-miR390-TAS3 pathway were found to additively regulate this transition in Arabidopsis. Together, our results demonstrate that RING1A/B regulates the vegetative phase transition in Arabidopsis through the repression of SPL family genes.
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Ehihara, Keikiti
1944-01-01
In internal combustion engines, steam engines, air compressors, and so forth, the piston ring plays an important role. Especially, the recent development of Diesel engines which require a high compression pressure for their working, makes, nowadays, the packing action of the piston ring far more important than ever. Though a number of papers have been published in regard to researches on the problem of the piston ring, none has yet dealt with an exact measurement of pressure exerted on the cylinder wall at any given point of the ring. The only paper that can be traced on this subject so far is Mr. Nakagawa's report on the determination of the relative distribution of pressure on the cylinder wall, but the measuring method adopted therein appears to need further consideration. No exact idea has yet been obtained as to how the obturation of gas between the piston and cylinder, the frictional resistance of the piston, and the wear of the cylinder wall are affected by the intensity and the distribution of the radial pressure of the piston ring. Consequently, the author has endeavored, by employing an apparatus of his own invention, to get an exact determination of the pressure distribution of the piston ring. By means of a newly devised ring tester, to which piezoelectricity of quartz was applied, the distribution of the radial pressure of many sample rings on the market was accurately determined. Since many famous piston rings show very irregular pressure distribution, the author investigated and achieved a manufacturing process of the piston ring which will exert uniform pressure on the cylinder wall. Temperature effects on the configuration and on the mean spring power have also been studied. Further, the tests were performed to ascertain how the gas tightness of the piston ring may be affected by the number or spring power. The researches as to the frictional resistance between the piston ring and the cylinder wall were carried out, too. The procedure of study, and
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Evidence for Break-Up of Clumps in Dynamically Stirred Regions of Saturn's Rings
Colwell, J. E.; Sega, D. N.; Jerousek, R. G.; Cooney, J. H.; Esposito, L. W.
2017-12-01
Stellar occultations of Saturn's rings observed by the Cassini Ultraviolet Imaging Spectrograph (UVIS) High Speed Photometer (HSP) record stellar brightness seen through the rings as photon counts that are described by Poisson counting statistics in the absence of intervening ring material. The variance in the data increases above counting statistics due to the discrete sizes of the ring particles, with larger particles leading to a larger variance at a given optical depth. We take advantage of the high spatial resolution and multiple viewing geometries of the UVIS occultations to study variations in particle size near and within strongly perturbed regions of Saturn's A ring, in particular the strong first order Lindblad resonances with Janus and the Mimas 5:3 Lindblad resonance and inner vertical resonance. The variance shows changes in the area-weighted particle size between peaks and troughs in the density waves as well as an overall decrease in particle size in the broad "halo" regions that bracket the strong Janus Lindblad resonances in the A ring. In addition we see a decrease in particle size at the location of the Mimas 5:3 bending wave wavetrain itself, and an increase in optical depth at the location of the wave when viewed from high elevation angles out of the ring plane. Taken together, these observations suggest that clumps of particles, perhaps the ubiquitous A ring self-gravity wakes, are disaggregated in the bending wave, even though standard bending wave theory does not predict enhanced collision velocities. We also examine the skewness, a higher order moment of the occultation data, that is diagnostic of asymmetries in the particle size distribution. We use Monte Carlo simulations of occultations to match the first three moments of the data (the signal mean, or equivalently the optical depth, the variance, and the skewness) to illustrate differences in ring particle size in these perturbed regions.
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Generation of stable mixed-compact-toroid rings by inducing plasma currents in strong E rings
International Nuclear Information System (INIS)
Jayakumar, R.; Taggart, D.P.; Parker, M.R.; Fleischmann, H.H.
1989-01-01
In the RECE-Christa device, hybrid-type compact toroid rings are generated by inducing large toroidal plasma currents I rho in strong electron rings using a thin induction coil positioned along the ring axis. Starting from field-reversal values δ ο = 50 - 120 percent of the original pure fast-electron ring, the induced plasma current I rho raises δ to a maximum value of up to 240 percent with I rho contributing more than 50 percent of the total ring current. Quite interestingly, the generated hybrid compact toroid configurations appear gross-stable during the full I rho pulse length (half-amplitude width about 100 μs)
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Magnetization of two coupled rings
International Nuclear Information System (INIS)
Avishai, Y; Luck, J M
2009-01-01
We investigate the persistent currents and magnetization of a mesoscopic system consisting of two clean metallic rings sharing a single contact point in a magnetic field. Many novel features with respect to the single-ring geometry are underlined, including the explicit dependence of wavefunctions on the Aharonov-Bohm fluxes, the complex pattern of two-fold and three-fold degeneracies, the key role of length and flux commensurability, and in the case of commensurate ring lengths the occurrence of idle levels which do not carry any current. Spin-orbit interactions, induced by the electric fields of charged wires threading the rings, give rise to a peculiar version of the Aharonov-Casher effect where, unlike for a single ring, spin is not conserved. Remarkably enough, this can only be realized when the Aharonov-Bohm fluxes in both rings are neither integer nor half-integer multiples of the flux quantum
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Ground Deformation Related to Caldera Collapse and Ring-Fault Activity
Liu, Yuan-Kai
2018-05-01
Volcanic subsidence, caused by partial emptying of magma in the subsurface reservoir has long been observed by spaceborne radar interferometry. Monitoring long-term crustal deformation at the most notable type of volcanic subsidence, caldera, gives us insights of the spatial and hazard-related information of subsurface reservoir. Several subsiding calderas, such as volcanoes on the Galapagos islands have shown a complex ground deformation pattern, which is often composed of a broad deflation signal affecting the entire edifice and a localized subsidence signal focused within the caldera floor. Although numerical or analytical models with multiple reservoirs are proposed as the interpretation, geologically and geophysically evidenced ring structures in the subsurface are often ignored. Therefore, it is still debatable how deep mechanisms relate to the observed deformation patterns near the surface. We aim to understand what kind of activities can lead to the complex deformation. Using two complementary approaches, we study the three-dimensional geometry and kinematics of deflation processes evolving from initial subsidence to later collapse of calderas. Firstly, the analog experiments analyzed by structure-from-motion photogrammetry (SfM) and particle image velocimetry (PIV) helps us to relate the surface deformation to the in-depth structures. Secondly, the numerical modeling using boundary element method (BEM) simulates the characteristic deformation patterns caused by a sill-like source and a ring-fault. Our results show that the volcano-wide broad deflation is primarily caused by the emptying of the deep magma reservoir, whereas the localized deformation on the caldera floor is related to ring-faulting at a shallower depth. The architecture of the ring-fault to a large extent determines the deformation localization on the surface. Since series evidence for ring-faulting at several volcanoes are provided, we highlight that it is vital to include ring
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Ground Deformation Related to Caldera Collapse and Ring-Fault Activity
Liu, Yuan-Kai
2018-01-01
Volcanic subsidence, caused by partial emptying of magma in the subsurface reservoir has long been observed by spaceborne radar interferometry. Monitoring long-term crustal deformation at the most notable type of volcanic subsidence, caldera, gives us insights of the spatial and hazard-related information of subsurface reservoir. Several subsiding calderas, such as volcanoes on the Galapagos islands have shown a complex ground deformation pattern, which is often composed of a broad deflation signal affecting the entire edifice and a localized subsidence signal focused within the caldera floor. Although numerical or analytical models with multiple reservoirs are proposed as the interpretation, geologically and geophysically evidenced ring structures in the subsurface are often ignored. Therefore, it is still debatable how deep mechanisms relate to the observed deformation patterns near the surface. We aim to understand what kind of activities can lead to the complex deformation. Using two complementary approaches, we study the three-dimensional geometry and kinematics of deflation processes evolving from initial subsidence to later collapse of calderas. Firstly, the analog experiments analyzed by structure-from-motion photogrammetry (SfM) and particle image velocimetry (PIV) helps us to relate the surface deformation to the in-depth structures. Secondly, the numerical modeling using boundary element method (BEM) simulates the characteristic deformation patterns caused by a sill-like source and a ring-fault. Our results show that the volcano-wide broad deflation is primarily caused by the emptying of the deep magma reservoir, whereas the localized deformation on the caldera floor is related to ring-faulting at a shallower depth. The architecture of the ring-fault to a large extent determines the deformation localization on the surface. Since series evidence for ring-faulting at several volcanoes are provided, we highlight that it is vital to include ring
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Colloidal-Quantum-Dot Ring Lasers with Active Color Control.
le Feber, Boris; Prins, Ferry; De Leo, Eva; Rabouw, Freddy T; Norris, David J
2018-02-14
To improve the photophysical performance of colloidal quantum dots for laser applications, sophisticated core/shell geometries have been developed. Typically, a wider bandgap semiconductor is added as a shell to enhance the gain from the quantum-dot core. This shell is designed to electronically isolate the core, funnel excitons to it, and reduce nonradiative Auger recombination. However, the shell could also potentially provide a secondary source of gain, leading to further versatility in these materials. Here we develop high-quality quantum-dot ring lasers that not only exhibit lasing from both the core and the shell but also the ability to switch between them. We fabricate ring resonators (with quality factors up to ∼2500) consisting only of CdSe/CdS/ZnS core/shell/shell quantum dots using a simple template-stripping process. We then examine lasing as a function of the optical excitation power and ring radius. In resonators with quality factors >1000, excitons in the CdSe cores lead to red lasing with thresholds at ∼25 μJ/cm 2 . With increasing power, green lasing from the CdS shell emerges (>100 μJ/cm 2 ) and then the red lasing begins to disappear (>250 μJ/cm 2 ). We present a rate-equation model that can explain this color switching as a competition between exciton localization into the core and stimulated emission from excitons in the shell. Moreover, by lowering the quality factor of the cavity we can engineer the device to exhibit only green lasing. The mechanism demonstrated here provides a potential route toward color-switchable quantum-dot lasers.
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Radioactive gold ring dermatitis
International Nuclear Information System (INIS)
Miller, R.A.; Aldrich, J.E.
1990-01-01
A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy
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Analytical model for double split ring resonators with arbitrary ring width
DEFF Research Database (Denmark)
Zhurbenko, Vitaliy; Jensen, Thomas; Krozer, Viktor
2008-01-01
For the first time, the analytical model for a double split ring resonator with unequal width rings is developed. The proposed models for the resonators with equal and unequal widths are based on an impedance matrix representation and provide the prediction of performance in a wide frequency range...
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Traffic Load on Interconnection Lines of Generalized Double Ring Network Structures
DEFF Research Database (Denmark)
Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Madsen, Ole Brun
2005-01-01
consists of two planar rings, which are easily embedded by fiber or other wired solutions. It is shown that for large N2R structures, the interconnection lines carry notably lower loads than the other lines if shortest-path routing is used, and the effects of two other routing schemes are explored, leading...
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Lee, S. Y Tina; Ghani, Amylia Abdul; D'Elia, Valerio; Cokoja, Mirza; Herrmann, Wolfgang A.; Basset, Jean-Marie; Kü hn, Fritz
2013-01-01
Ring opening of various nickela- and palladalactones induced by the cleavage of the M-O bond by methyl trifluoromethanesulfonate (MeOTf) and methyl iodide (MeI) is examined. Experimental evidence supports the mechanism of ring opening by the alkylating agent followed by β-H elimination leading to methyl acrylate and a metal-hydride species. MeOTf shows by far higher efficiency in the lactone ring opening than any other methylating agent including the previously reported methyl iodide. © 2013 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
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International Nuclear Information System (INIS)
Tsarev, Andrei V
2009-01-01
Pure subrings of finite rank in the Z-adic completion of the ring of integers and in its homomorphic images are considered. Certain properties of these rings are studied (existence of an identity element, decomposability into a direct sum of essentially indecomposable ideals, condition for embeddability into a csp-ring, etc.). Additive groups of these rings and conditions under which these rings are subrings of algebraic number fields are described. Bibliography: 12 titles.
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International Nuclear Information System (INIS)
Gisler, G.; Faehl, R.
1983-01-01
We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package
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BODY MASS INDEX AND WAIST CIRCUMFERENCE IN GREEK ADULTS
Directory of Open Access Journals (Sweden)
Mavrovounioti, Chr.
2009-03-01
Full Text Available The aim of the present study was to investigate overweight and obesity, in Greek adults. In the presentstudy, 110 men and women, 19- to 60 years old, took part. Measurements of subject’s height, body weight, andwaist circumference (WC were performed. BMI was used for the evaluation of the degree of overweight andobesity and WC for the evaluation of the degree of central obesity, according to the values for adults set byWorld Health Organisation (WHO. For the statistical analysis the statistic packet SPSS/PC version 12.0 forwindows was used. From data statistical analysis, it was found out that men had BMI 24.94+3.22 kg/m2 and WC90.78+13.24cm, while women had BMI 22.99+4.75 kg/m2 and WC 80.64+11.19cm. T-tests showed that theobserved differences between men and women in both BMI and WC were significant (t=2.51, p<0.05 andt=4.34, p<0.001, respectively. Additionally, it was found out that more than half of the men were overweightand/or obese (51.9%, while approximately the 1/5th of women were overweight and/or obese (21.5%. Chisquaretest showed that sex affects significantly the degree of overweight and obesity (x2=18.14, p<0.001.Moreover, men presented central obesity to a percentage of 11.1%, while women presented central obesity to a smaller percentage (3.60%. Consequently, in the present study, there were observed high percentages of overweight and obesity, as well as of central obesity, especially on men. Thus, a combination of an exercise program with a balanced diet is suggested in order to lead to a normal body weight and normal abdominal fat quantity for an enhanced quality of life without health disorders due to obesity.
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DEFF Research Database (Denmark)
Dalgård, Christine; Petersen, Maria Skaalum; Steuerwald, Ulrike
2016-01-01
infants. In the third trimester, the pregnant women completed questionnaires, and clinical examination included birthweight, head circumference, and infant length at age 14 days. RESULTS: Fifty-three percent of the newborn population had UC 25(OH)D ... linear regression models with adjustment for pre-pregnancy BMI, sex, parity, gestational age, or infant age at examination, season of birth, smoking, gestational diabetes, examiner, and cohort identity, we found no relationship between birthweight or head circumference and UC 25(OH)D. However, infants...
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Self-generation of dissipative solitons in magnonic quasicrystal active ring resonator
International Nuclear Information System (INIS)
Grishin, S. V.; Beginin, E. N.; Morozova, M. A.; Sharaevskii, Yu. P.; Nikitov, S. A.
2014-01-01
Self-generation of dissipative solitons in the magnonic quasicrystal (MQC) active ring resonator is studied theoretically and experimentally. The developed magnonic crystal has quasiperiodic Fibonacci type structure. Frequency selectivity of the MQC together with the parametric three-wave decay of magnetostatic surface spin wave (MSSW) leads to the dissipative soliton self-generation. The transfer matrix method is used to describe MQC transmission responses. Besides, the model of MQC active ring resonator is suggested. The model includes three coupled differential equations describing the parametric decay of MSSW and two differential equations of linear oscillators describing the frequency selectivity of MQC. Numerical simulation results of dissipative soliton self-generation are in a fair agreement with experimental data
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Three dimensional atom probe imaging of GaAsSb quantum rings
International Nuclear Information System (INIS)
Beltran, A.M.; Marquis, E.A.; Taboada, A.G.; Ripalda, J.M.; Garcia, J.M.; Molina, S.I.
2011-01-01
Unambiguous evidence of ring-shaped self-assembled GaSb nanostructures grown by molecular beam epitaxy is presented on the basis of atom-probe tomography reconstructions and dark field transmission electron microscopy imaging. The GaAs capping process causes a strong segregation of Sb out of the center of GaSb quantum dots, leading to the self-assembled GaAs x Sb 1-x quantum rings of 20-30 nm in diameter with x∼0.33. -- Highlights: → Atom-probe tomography resolves QR morphology of GaSb self-assembled GaSb buried nanostructures. → From atom-probe tomography compositional distribution has been obtained. → Strong segregation and morphological changes are observed with respect to uncapped QR.
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Traffic Load on Interconnection Lines of Generalized Double Ring Network Structures
DEFF Research Database (Denmark)
Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Madsen, Ole Brun
2004-01-01
Generalized Double Ring (N2R) network structures possess a number of good properties, but being not planar they are hard to physically embed in communication networks. However, if some of the lines, the interconnection lines, are implemented by wireless technologies, the remaining structure...... consists of two planar rings, which are easily embedded by fiber or other wired solutions. It is shown that for large N2R structures, the interconnection lines carry notably lower loads than the other lines if shortest-path routing is used, and the effects of two other routing schemes are explored, leading...... to lower load on interconnection lines at the price of larger efficient average distance and diameter....
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Self-generation of dissipative solitons in magnonic quasicrystal active ring resonator
Energy Technology Data Exchange (ETDEWEB)
Grishin, S. V., E-mail: grishfam@sgu.ru; Beginin, E. N.; Morozova, M. A.; Sharaevskii, Yu. P. [Laboratory “Metamaterials,” Saratov State University, Saratov 410012 (Russian Federation); Nikitov, S. A. [Laboratory “Metamaterials,” Saratov State University, Saratov 410012 (Russian Federation); Kotel' nikov Institute of Radioengineering and Electronics, Russian Academy of Science, Moscow 125009 (Russian Federation)
2014-02-07
Self-generation of dissipative solitons in the magnonic quasicrystal (MQC) active ring resonator is studied theoretically and experimentally. The developed magnonic crystal has quasiperiodic Fibonacci type structure. Frequency selectivity of the MQC together with the parametric three-wave decay of magnetostatic surface spin wave (MSSW) leads to the dissipative soliton self-generation. The transfer matrix method is used to describe MQC transmission responses. Besides, the model of MQC active ring resonator is suggested. The model includes three coupled differential equations describing the parametric decay of MSSW and two differential equations of linear oscillators describing the frequency selectivity of MQC. Numerical simulation results of dissipative soliton self-generation are in a fair agreement with experimental data.
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Manipulation of vortex rings for flow control
International Nuclear Information System (INIS)
Toyoda, Kuniaki; Hiramoto, Riho
2009-01-01
This paper reviews the dynamics of vortex rings and the control of flow by the manipulation of vortex rings. Vortex rings play key roles in many flows; hence, the understanding of the dynamics of vortex rings is crucial for scientists and engineers dealing with flow phenomena. We describe the structures and motions of vortex rings in circular and noncircular jets, which are typical examples of flows evolving into vortex rings. For circular jets the mechanism of evolving, merging and breakdown of vortex rings is described, and for noncircular jets the dynamics of three-dimensional deformation and interaction of noncircular vortex rings under the effect of self- and mutual induction is discussed. The application of vortex-ring manipulation to the control of various flows is reviewed with successful examples, based on the relationship between the vortex ring dynamics and the flow properties. (invited paper)
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Cuzzi, J. N.; Filacchione, G.; Marouf, E. A.
2018-03-01
One could become an expert on Saturn's iconic rings pretty easily in the early 1970s, as very little was known about them beyond the distinction between the A, B, and C rings, and the Cassini Division or "gap" between rings A and B (Alexander, 1962; Bobrov, 1970). Water ice was discovered spectroscopically on the ring particle surfaces, and radar and microwave emission observations proved that the particles must be centimeters to meters in size, consisting primarily, not just superficially, of water ice (Pollack, 1975). While a 2:1 orbital resonance with Mimas had long been suspected of having something to do with the Cassini Division, computers of the time were unable to model the subtle dynamical effects that we now know to dominate ring structure. This innocent state of affairs was exploded by the Voyager 1 and 2 encounters in 1980 and 1981. Spectacular images revealed filigree structure and odd regional color variations, and exquisitely detailed radial profiles of fluctuating particle abundance were obtained from the first stellar and radio occultations, having resolution almost at the scale of single particles. Voyager-era understanding was reviewed by Cuzzi et al. (1984) and Esposito et al. (1984). While the Voyager data kept ring scientists busy for decades, planning which led to the monumentally successful NASA-ESA-ASI Cassini mission, which arrived in 2004, had been under way even before Voyager got to Saturn. A review of pre-Cassini knowledge of Saturn's Rings can be found in Orton et al. (2009). This chapter will build on recent topical and process-specific reviews that treat the gamut of ring phenomena and its underlying physics in considerable detail (Colwell et al., 2009; Cuzzi et al., 2009; Horányi et al., 2009; Schmidt et al., 2009; Esposito, 2010; Tiscareno, 2013b; Esposito, 2014). We will follow and extend the general organization of Cuzzi et al. (2010), the most recent general discussion of Saturn's rings. For brevity and the benefit of the
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Siavash, Mansour; Naseri, Mohsen; Rahimi, Mojgan
2016-01-01
Obesity is a worldwide health problem which is associated with a lot of complications. One of these comorbidities is the metabolic syndrome that is in correlation with abdominal fat thickness and waist circumference. Various methods were used to reduce abdominal fat thickness such as liposuction. A noninvasive method is the topical agent. In this study, we investigated the effectiveness of Arnebia euchroma (AE) ointment on the abdominal fat thickness. This study was a double-blind clinical trial which was done at the endocrinology clinic in Khorshid Hospital, Isfahan, Iran, in 2014. After explaining the procedure and obtaining informed consent, the candidates were randomly divided into the case and control groups. The participants of the case and control groups applied AE ointment or placebo for 6 weeks on their abdominal area. Body mass index, waist and buttock circumference, and abdominal fat thickness were measured in both case and control groups at their first visit and then at the next 2, 4, and 6 weeks. We used t -test for comparing parametric variables between groups, paired t -test for changes from baseline to final, and repeated measure ANOVA for changes at different steps. Sixty female candidates participated in this study (thirty in each group). Ten patients left the study and fifty participants finished the trial. At the end of the study, participants had a significant weight loss (2.96 ± 1.6 kg, P Abdominal circumference also decreased significantly in the participants (11.3 ± 6.7 cm, P abdominal fat thickness decreased significantly in the participants (2.3 ± 1.1 cm, P abdominal fat thickness as well as the waist circumference without causing any side effect.
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The reaction of Lupinus angustifolius L. root meristematic cell nucleoli to lead.
Balcerzak, Lucja; Glińska, Sława; Godlewski, Mirosław
2011-04-01
The effect of 2-48 h treatment of Lupinus angustifolius L. roots with lead nitrate at the concentration of 10(-4) M on the nucleoli in meristematic cells was investigated. In the lead presence the number of ring-shaped as well as segregated nucleoli increased especially after 12-48 h of treatment, while spindle-shaped nucleoli appeared after 24 h and 48 h. Lead presence also increased the frequency of cells with silver-stained particles in the nucleus and the number of these particles especially from the 12th hour of treatment. It was accompanied by significant decline of nucleolar area. Analysis of these cells in transmission electron microscope confirmed the presence of ring-shaped and segregated nucleoli. Moreover, electron microscopy revealed compact structure nucleoli without granular component. Additionally, one to three oval-shaped fibrillar structures attached to nucleolus or lying free in the nucleoplasm were visible. The possible mechanism of lead toxicity to the nucleolus is briefly discussed.
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Directory of Open Access Journals (Sweden)
Mohammad H. Rahbar
2015-04-01
Full Text Available The objective of this study was to characterize the concentrations of lead, mercury, cadmium, aluminum, and manganese in umbilical cord blood of Jamaican newborns and to explore the possible association between concentrations of these elements and certain birth outcomes. Based on data from 100 pregnant mothers and their 100 newborns who were enrolled from Jamaica in 2011, the arithmetic mean (standard deviation concentrations of cord blood lead, mercury, aluminum, and manganese were 0.8 (1.3 μg/dL, 4.4 (2.4 μg/L, 10.9 (9.2 μg/L, and 43.7 (17.7 μg/L, respectively. In univariable General Linear Models, the geometric mean cord blood aluminum concentration was higher for children whose mothers had completed their education up to high school compared to those whose mothers had any education beyond high school (12.2 μg/L vs. 6.4 μg/L; p < 0.01. After controlling for maternal education level and socio-economic status (through ownership of a family car, the cord blood lead concentration was significantly associated with head circumference (adjusted p < 0.01. Our results not only provide levels of arsenic and the aforementioned metals in cord blood that could serve as a reference for the Jamaican population, but also replicate previously reported significant associations between cord blood lead concentrations and head circumference at birth in other populations.
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Rahbar, Mohammad H.; Samms-Vaughan, Maureen; Dickerson, Aisha S.; Hessabi, Manouchehr; Bressler, Jan; Coore Desai, Charlene; Shakespeare-Pellington, Sydonnie; Reece, Jody-Ann; Morgan, Renee; Loveland, Katherine A.; Grove, Megan L.; Boerwinkle, Eric
2015-01-01
The objective of this study was to characterize the concentrations of lead, mercury, cadmium, aluminum, and manganese in umbilical cord blood of Jamaican newborns and to explore the possible association between concentrations of these elements and certain birth outcomes. Based on data from 100 pregnant mothers and their 100 newborns who were enrolled from Jamaica in 2011, the arithmetic mean (standard deviation) concentrations of cord blood lead, mercury, aluminum, and manganese were 0.8 (1.3 μg/dL), 4.4 (2.4 μg/L), 10.9 (9.2 μg/L), and 43.7 (17.7 μg/L), respectively. In univariable General Linear Models, the geometric mean cord blood aluminum concentration was higher for children whose mothers had completed their education up to high school compared to those whose mothers had any education beyond high school (12.2 μg/L vs. 6.4 μg/L; p < 0.01). After controlling for maternal education level and socio-economic status (through ownership of a family car), the cord blood lead concentration was significantly associated with head circumference (adjusted p < 0.01). Our results not only provide levels of arsenic and the aforementioned metals in cord blood that could serve as a reference for the Jamaican population, but also replicate previously reported significant associations between cord blood lead concentrations and head circumference at birth in other populations. PMID:25915835
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Examination techniques for non-magnetic rings
International Nuclear Information System (INIS)
Metala, M.J.; Kilpatrick, N.L.; Frank, W.W.
1990-01-01
Until the introduction of 18Mn18Cr rings a few years ago, most non-magnetic steel rings for generator rotors were made from 18Mn5Cr alloy steel, which is highly susceptible to stress corrosion cracking in the presence of water. This, the latest in a series of papers on the subject of non-magnetic rings by the authors' company, provides a discussion of nondestructive examination of 18Mn5Cr rings for stress corrosion distress. With rings on the rotor, fluorescent penetrant, ultrasonic and special visual techniques are applied. With rings off the rotor, the fluorescent penetrant technique is used, with and without stress enhancement
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Waist circumference adjusted for body mass index and intra-abdominal fat mass
DEFF Research Database (Denmark)
Berentzen, Tina Landsvig; Ängquist, Lars; Kotronen, Anna
2012-01-01
The association between waist circumference (WC) and mortality is particularly strong and direct when adjusted for body mass index (BMI). One conceivable explanation for this association is that WC adjusted for BMI is a better predictor of the presumably most harmful intra-abdominal fat mass (IAFM......) than WC alone. We studied the prediction of abdominal subcutaneous fat mass (ASFM) and IAFM by WC alone and by addition of BMI as an explanatory factor....
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The Age of Saturn's Rings Constrained by the Meteoroid Flux Into the System
Kempf, S.; Altobelli, N.; Srama, R.; Cuzzi, J. N.; Estrada, P. R.
2017-12-01
The origin of Saturn's ring is still not known. There is an ongoing argument whether Saturn's ring are rather young or have been formed shortly after Saturn together with its satellites. The water-ice rings contain about 5% rocky material resulting from continuous meteoroid bombardment of the ring material with interplanetary micrometeoroids. Knowledge of the incoming mass flux would allow to estimate the ring's exposure time. Model calculations suggest exposure times of 108 years implying a late ring formation. This scenario is problematic because the tidal disruption of a Mimas-sized moon or of a comet within the planet's Roche zone would lead to a much larger rock content as observed today. Here we report on the measurement of the meteoroid mass flux into the Saturnian system obtained by the charge-sensitive entrance grid system (QP) of the Cosmic Dust Analyser (CDA) on the Cassini spacecraft. Interplanetary dust particles (IDPs) entering Saturn's sphere of gravitational influence are identified through the measurements of their speed vectors. We analyzed the full CDA data set acquired after Cassini's arrival at Saturn in 2004, identified the impact speed vectors of 128 extrinsic micrometeoroids ≥ 2 μm, and determined their orbital elements. On the basis of these measurements we determined the mass flux into the Saturnian system. Our preliminary findings are in support of an old ring. The knowledge of the meteoroids orbital elements allows us for the first time to characterize the meteoroid environment in the outer solar system based on direct measurements.
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Electronic States and Persistent Currents in Nanowire Quantum Ring
Kokurin, I. A.
2018-04-01
The new model of a quantum ring (QR) defined inside a nanowire (NW) is proposed. The one-particle Hamiltonian for electron in [111]-oriented NW QR is constructed taking into account both Rashba and Dresselhaus spin-orbit coupling (SOC). The energy levels as a function of magnetic field are found using the exact numerical diagonalization. The persistent currents (both charge and spin) are calculated. The specificity of SOC and arising anticrossings in energy spectrum lead to unusual features in persistent current behavior. The variation of magnetic field or carrier concentration by means of gate can lead to pure spin persistent current with the charge current being zero.
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General overview and a review of storage rings, research facilities, and insertion devices
International Nuclear Information System (INIS)
Winick, H.
1989-01-01
Synchrotron radiation, the electromagnetic radiation given off by electrons in circular motion, is revolutionizing many branches of science and technology by offering beams of vacuum ultraviolet light and x rays of immense flux and brightness. In the past decade there has been an explosion of interest in these applications leading to increased exploitation of existing rings and activity to construct new research facilities based on advanced storage rings and insertion device sources. Applications include basic and applied research in biology, chemistry, medicine, and physics plus many areas of technology. In this article they present a general overview of the field of synchrotron radiation research, its history, the present status and future prospects of storage rings and research facilities, and the development of wiggler and undulator insertion devices as sources of synchrotron radiation. 66 references, 20 figures, 1 table
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Cucurbit[8]uril templated supramolecular ring structure formation and protein assembly modulation
Ramaekers, M.; Wijnands, S.P.W.; van Dongen, J.L.J.; Brunsveld, L.; Dankers, P.Y.W.
2015-01-01
The interplay of Phe-Gly-Gly (FGG)-tagged proteins and bivalent FGG-tagged penta(ethylene glycol) as guest molecules with cucurbit[8]uril (Q8) hosts is studied to modulate the supramolecular assembly process. Ring structure formation of the bivalent guest molecule with Q8 leads to enhanced binding
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Self-gravitation in Saturn's rings
International Nuclear Information System (INIS)
Salo, H.; Lukkari, J.
1982-01-01
In a ring-shaped collisional system self-gravitation reduces the equilibrium values of the geometric and optical thickness. In Saturn's rings both effects are appreciable. The previously found discrepancy between the calculated profile and the observed profile of the rings is chiefly caused by the omission of self-gravitation. (Auth.)
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Modeling photo-desorption in high current storage rings
International Nuclear Information System (INIS)
Barletta, W.A.
1991-01-01
High luminosity flavor factories are characterized by high fluxes of synchrotron radiation that lead to thermal management difficulties. The associated photo-desorption from the vacuum chamber walls presents an additional design challenge, providing a vacuum system suitable for maintaining acceptable beam-gas lifetimes and low background levels of scattered radiation in the detector. Achieving acceptable operating pressures (1-10 nTorr) with practical pumping schemes requires the use of materials with low photodesorption efficiency operating in a radiation environment beyond that of existing storage rings. Extrapolating the existing photo-desorption data base to the design requirements of high luminosity colliders requires a physical model of the differential cleaning in the vacuum chamber. The authors present a simple phenomenological model of photodesorption that includes effects of dose dependence and diffuse photon reflection to compute the leveling of gas loads in beamlines of high current storage rings that typify heavy flavor factories. This model is also used to estimate chamber commissioning times
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Colombian reference growth curves for height, weight, body mass index and head circumference.
Durán, Paola; Merker, Andrea; Briceño, Germán; Colón, Eugenia; Line, Dionne; Abad, Verónica; Del Toro, Kenny; Chahín, Silvia; Matallana, Audrey Mary; Lema, Adriana; Llano, Mauricio; Céspedes, Jaime; Hagenäs, Lars
2016-03-01
Published Growth studies from Latin America are limited to growth references from Argentina and Venezuela. The aim of this study was to construct reference growth curves for height, weight, body mass index (BMI) and head circumference of Colombian children in a format that is useful for following the growth of the individual child and as a tool for public health. Prospective measurements from 27 209 Colombian children from middle and upper socio-economic level families were processed using the generalised additive models for location, scale and shape (GAMLSS). Descriptive statistics for length and height, weight, BMI and head circumference for age are given as raw and smoothed values. Final height was 172.3 cm for boys and 159.4 cm for girls. Weight at 18 years of age was 64.0 kg for boys and 54 kg for girls. Growth curves are presented in a ± 3 SD format using logarithmic axes. The constructed reference growth curves are a start for following secular trends in Colombia and are also in the presented layout an optimal clinical tool for health care. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
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Comparison of Relative Waist Circumference between Asian Indian and US Adults
Directory of Open Access Journals (Sweden)
Harpreet S. Bajaj
2014-01-01
Full Text Available Background. Relative to Europeans, Asian Indians have higher rates of type 2 diabetes and cardiovascular disease. Whether differences in body composition may underlie these population differences remains unclear. Methods. We compared directly measured anthropometric data from the Chennai Urban Rural Epidemiology Study (CURES survey of southern Indians (I with those from three US ethnic groups (C: Caucasians, A: African Americans, and M: Mexican Americans from NHANES III (Third National Health and Nutrition Examination Survey. A total of 15,733 subjects from CURES and 5,975 from NHANES III met inclusion criteria (age 20–39, no known diabetes. Results. Asian Indian men and women had substantially lower body mass index, waist circumference, hip circumference, waist-to-hip ratio, and body surface area relative to US groups (P values <0.0001. In contrast, the mean (±se waist-weight ratio was significantly higher (P<0.001 in I (men 1.35 ± 0.002 and women 1.45 ± 0.002 than in all the US groups (1.09, 1.21, and 1.14 in A, M, and C men; 1.23, 1.33, and 1.26 in A, M, and C women (se ranged from 0.005 to 0.006. Conclusions. Compared to the US, the waist-weight ratio is significantly higher in men and women from Chennai, India. These results support the hypothesis that Southeast Asian Indians are particularly predisposed toward central adiposity.
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Split ring containment attachment device
International Nuclear Information System (INIS)
Sammel, A.G.
1996-01-01
A containment attachment device is described for operatively connecting a glovebag to plastic sheeting covering hazardous material. The device includes an inner split ring member connected on one end to a middle ring member wherein the free end of the split ring member is inserted through a slit in the plastic sheeting to captively engage a generally circular portion of the plastic sheeting. A collar potion having an outer ring portion is provided with fastening means for securing the device together wherein the glovebag is operatively connected to the collar portion. 5 figs
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An N-body Integrator for Planetary Rings
Hahn, Joseph M.
2011-04-01
A planetary ring that is disturbed by a satellite's resonant perturbation can respond in an organized way. When the resonance lies in the ring's interior, the ring responds via an m-armed spiral wave, while a ring whose edge is confined by the resonance exhibits an m-lobed scalloping along the ring-edge. The amplitude of these disturbances are sensitive to ring surface density and viscosity, so modelling these phenomena can provide estimates of the ring's properties. However a brute force attempt to simulate a ring's full azimuthal extent with an N-body code will likely fail because of the large number of particles needed to resolve the ring's behavior. Another impediment is the gravitational stirring that occurs among the simulated particles, which can wash out the ring's organized response. However it is possible to adapt an N-body integrator so that it can simulate a ring's collective response to resonant perturbations. The code developed here uses a few thousand massless particles to trace streamlines within the ring. Particles are close in a radial sense to these streamlines, which allows streamlines to be treated as straight wires of constant linear density. Consequently, gravity due to these streamline is a simple function of the particle's radial distance to all streamlines. And because particles are responding to smooth gravitating streamlines, rather than discrete particles, this method eliminates the stirring that ordinarily occurs in brute force N-body calculations. Note also that ring surface density is now a simple function of streamline separations, so effects due to ring pressure and viscosity are easily accounted for, too. A poster will describe this N-body method in greater detail. Simulations of spiral density waves and scalloped ring-edges are executed in typically ten minutes on a desktop PC, and results for Saturn's A and B rings will be presented at conference time.
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International Nuclear Information System (INIS)
Przyjalkowski, V V
2008-01-01
We construct an abstract theory of Gromov-Witten invariants of genus 0 for quantum minimal Fano varieties (a minimal class of varieties which is natural from the quantum cohomological viewpoint). Namely, we consider the minimal Gromov-Witten ring: a commutative algebra whose generators and relations are of the form used in the Gromov-Witten theory of Fano varieties (of unspecified dimension). The Gromov-Witten theory of any quantum minimal variety is a homomorphism from this ring to C. We prove an abstract reconstruction theorem which says that this ring is isomorphic to the free commutative ring generated by 'prime two-pointed invariants'. We also find solutions of the differential equation of type DN for a Fano variety of dimension N in terms of the generating series of one-pointed Gromov-Witten invariants
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Leak Rate Performance of Silicone Elastomer O-Rings Contaminated with JSC-1A Lunar Regolith Simulant
Oravec, Heather Ann; Daniels, Christopher C.
2014-01-01
Contamination of spacecraft components with planetary and foreign object debris is a growing concern. Face seals separating the spacecraft cabin from the debris filled environment are particularly susceptible; if the seal becomes contaminated there is potential for decreased performance, mission failure, or catastrophe. In this study, silicone elastomer O-rings were contaminated with JSC- 1A lunar regolith and their leak rate performance was evaluated. The leak rate values of contaminated O-rings at four levels of seal compression were compared to those of as-received, uncontaminated, O-rings. The results showed a drastic increase in leak rate after contamination. JSC-1A contaminated O-rings lead to immeasurably high leak rate values for all levels of compression except complete closure. Additionally, a mechanical method of simulant removal was examined. In general, this method returned the leak rate to as-received values.
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Electro-optical hybrid slip ring
Hong, En
2005-11-01
The slip ring is a rotary electrical interface, collector, swivel or rotary joint. It is a physical system that can perform continuous data transfer and data exchange between a stationary and a rotating structure. A slip ring is generally used to transfer data or power from an unrestrained, continuously rotating electro-mechanical system in real-time, thereby simplifying operations and eliminating damage-prone wires dangling from moving joints. Slip rings are widely used for testing, evaluating, developing and improving various technical equipment and facilities with rotating parts. They are widely used in industry, especially in manufacturing industries employing turbo machinery, as in aviation, shipbuilding, aerospace, defense, and in precise facilities having rotating parts such as medical Computerized Tomography (CT) and MRI scanners and so forth. Therefore, any improvement in slip ring technology can impact large markets. Research and development in this field will have broad prospects long into the future. The goal in developing the current slip ring technology is to improve and increase the reliability, stability, anti-interference, and high data fidelity between rotating and stationary structures. Up to now, there have been numerous approaches used for signal and data transfer utilizing a slip ring such as metal contacts, wires, radio transmission, and even liquid media. However, all suffer from drawbacks such as data transfer speed limitations, reliability, stability, electro-magnetic interference and durability. The purpose of the current research is to break through these basic limitations using an optical solution, thereby improving performance in current slip ring applications. This dissertation introduces a novel Electro-Optical Hybrid Slip Ring technology, which makes "through the air" digital-optical communication between stationary and rotating systems a reality with high data transfer speed, better reliability and low interference susceptibility
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Schoene, C; Bennett, S P; Howarth, M
2016-01-01
Enzymes often have marginal stability, with unfolding typically leading to irreversible denaturation. This sensitivity is a major barrier, both for de novo enzyme development and for expanding enzyme impact beyond the laboratory. Seeking an approach to enhance resilience to denaturation that could be applied to a range of different enzymes, we developed SpyRing cyclization. SpyRings contain genetically encoded SpyTag (13 amino acids) on the N-terminus and SpyCatcher (12kDa) on the C-terminus of the enzyme, so that the Spy partners spontaneously react together through an irreversible isopeptide bond. SpyRing cyclization gave major increases in thermal resilience, including on a model for enzyme evolution, β-lactamase, and an industrially important enzyme in agriculture and nutrition, phytase. We outline the SpyRing rationale, including comparison of SpyRing cyclization to other cyclization strategies. The cloning strategy is presented for the simple insertion of enzyme genes for recombinant expression. We discuss structure-based approaches to select suitable enzyme cyclization targets. Approaches to evaluate the cyclization reaction and its effect on enzyme resilience are described. We also highlight the use of differential scanning calorimetry to understand how SpyRing cyclization promotes enzyme refolding. Efficiently searching sequence space will continue to be important for enzyme improvement, but the SpyRing platform may be a valuable rational adjunct for conferring resilience. © 2016 Elsevier Inc. All rights reserved.
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Double acting stirling engine piston ring
Howarth, Roy B.
1986-01-01
A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.
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Fusion Rings for Quantum Groups
DEFF Research Database (Denmark)
Andersen, Henning Haahr; Stroppel, Catharina
2012-01-01
We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...
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Warner, S
1993-01-01
This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.
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Forandringslæring med autismediagnoser?
DEFF Research Database (Denmark)
Gustafson, Kari Ingrid; Mørck, Line Lerche
2013-01-01
Artiklen drøfter en række aktuelle spørgsmål omkring læring hos børn og unge med autisme-spektrum-forstyrrelses diagnoser. Der introduceres til en social praksisteoretisk forståelse af forandringslæring, der diskuterer forandring ikke kun i relation til en persons identitet, men også aktuelle og...... potentielle forandringer, når det gælder overskridelse af binær logik i autisme versus normalitet, samt i relation til at overskride individualiserede og dualistiske problem-forståelser af fejl og mangler ved det autistiske barn. Det illustreres, hvordan disse former for dualistisk tænkning er forankret i et...... Rasmus’ ændringer i læring, selvforståelse og tilhørsforhold perspektiveres med andre ASF-diagnostiseredes læring udforsket bl.a. gennem gruppeinterviews i regi af Asperger-foreningen. Artiklen byder således på et alternativ i form af at forstå forandringslæring som overskridende læring, med langt større...
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Garcia, Lorena; Qi, Lihong; Rasor, Marianne; Clark, Cari Jo; Bromberger, Joyce; Gold, Ellen B
2014-05-01
This article investigates the associations of violence and traumatic stress with changes in weight and waist circumference, hypothesizing that violence in midlife would be associated with increases or decreases in weight and waist circumference. The longitudinal cohort of the Study of Women's Health Across the Nation comprised the study sample, which included an ethnically/racially and socially diverse group of 2,870 women between the ages of 42 and 52 years at baseline. Women were followed annually for 10 years, and assessments included weight and waist circumference measures and data on violence, health outcomes, and confounders. At baseline, 8.6% Caucasian, 10.8% African American, 9.2% Chinese, and 5.0% Japanese women reported violence and traumatic stress. Reporting violence and traumatic stress during follow-up was significantly associated with weight gain (odds ratio [OR] = 2.39, 95% confidence interval [CI] = [1.28-4.47]), weight loss (OR = 3.54, 95% CI = [1.73-7.22]), and gain (OR = 2.44, 95% CI = [1.37-4.37]) or loss (OR = 2.66, 95% CI = [1.23-5.77]) in waist circumference, adjusting for age, race/ethnicity, education, marital status, and smoking. Violence and traumatic stress against midlife women were associated with gains or losses in weight and waist circumference.
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Changes in waist circumference and the incidence of diabetes in middle-aged men and women
DEFF Research Database (Denmark)
Berentzen, Tina Landsvig; Jakobsen, Marianne Uhre; Halkjaer, Jytte
2011-01-01
Waist circumference (WC) is positively associated with diabetes, but the association with changes in WC (DWC) is less clear. We investigated the association between DWC and the subsequent risk of diabetes in middle-aged men and women, and evaluated the influence from concurrent changes in body mass...
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The Lord of Rings - the mysterious case of the stolen rings: a critical analysis
Sandrelli, S.
The Lord of Rings - the mysterious case of the stolen rings: a critical analysis S. Sandrelli INAF - Osservatorio Astronomico di Brera, Milano, Italy (stefano.sandrelli@brera.inaf.it / Fax: 02 72001600 / Phone: +39 02 72320337) "The Lord of Rings - the mysterious case of the stolen rings" is a live astronomical role-playing game for kids aged 10 -13. Its goal is to introduce them to some of the main topics of the Solar System: a) the role of gravity; b) the distribution of mass & light; c) the effects of rotation; d) the distribution of water. The game was held both at the Perugia (2004) and the Genova Science Festival (2005), obtaining great success. Teams of about 6-8 members are introduced to Mr Schioppanelli, the astro-detective of the town (the name is a pun: it reminds Schiaparelli, the famous italian astronomer, and it is a slang expression meaning "ring-breaker"). Mr Schioppanelli has his office in an "gastronomical astronomical observatory", known as The Red Giant Pizzeria. Schioppanelli informs the kids that a mysterious Centaur succeded in stealing the rings of Saturn. The partecipants are appointed astro-detectives in-charge and asked to find the rings by browsing around the Solar System, which is scaled so as to fit the town historical centre or a pedestrian area, going from the Sun to Saturn or beyond, depending on the actual area at disposal. Great care must be taken allowing children playing only in a car-free area of the town. At the right scaled distances, the partecipants meet characters playing as the various planets. The kids can talk to them after solving a riddle, obtaining useful informations. A special characters play as a comet, timely going in and out of the inner solar system. The teams can also talk to some shepherd-moons of the rings. They easily discover that the rings were totally destroyed by the Centaur: a real disaster! They are also suggested to gather the necessary ingredients (gravity, light, rotation, inclination, dust and
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Buckling behaviour of imperfect ring-stiffened cone-cylinder intersections under internal pressure
International Nuclear Information System (INIS)
Zhao, Y.
2005-01-01
Cone-cylinder intersections are used commonly in pressure vessels and piping. In the case of a cone large end-to-cylinder intersection under internal pressure, the intersection is subject to a large circumferential compressive force. While both the cone and the cylinder may be locally thickened to strengthen the intersection, it is often desirable and convenient to provide an annular plate ring at the cone-to-cylinder joint to supplement local thickening or as an alternative strengthening measure, leading to a ring-stiffened cone-cylinder intersection. Only limited work has been carried out specifically on ring-stiffened cone-cylinder intersections under internal pressure. This paper presents the first experimental study on such intersections. In addition to the presentation of test results including geometric imperfections, failure behaviour and the determination of buckling mode and load based on displacement measurements, results from nonlinear bifurcation analysis using the perfect shape and nonlinear analysis using the measured imperfect shape are presented and compared with the experimental results
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Reducing support loss in micromechanical ring resonators using phononic band-gap structures
Energy Technology Data Exchange (ETDEWEB)
Hsu, Feng-Chia; Huang, Tsun-Che; Wang, Chin-Hung; Chang, Pin [Industrial Technology Research Institute-South, Tainan 709, Taiwan (China); Hsu, Jin-Chen, E-mail: fengchiahsu@itri.org.t, E-mail: hsujc@yuntech.edu.t [Department of Mechanical Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan (China)
2011-09-21
In micromechanical resonators, energy loss via supports into the substrates may lead to a low quality factor. To eliminate the support loss, in this paper a phononic band-gap structure is employed. We demonstrate a design of phononic-crystal (PC) strips used to support extensional wine-glass mode ring resonators to increase the quality factor. The PC strips are introduced to stop elastic-wave propagation by the band-gap and deaf-band effects. Analyses of resonant characteristics of the ring resonators and the dispersion relations, eigenmodes, and transmission properties of the PC strips are presented. With the proposed resonator architecture, the finite-element simulations show that the leaky power is effectively reduced and the stored energy inside the resonators is enhanced simultaneously as the operating frequencies of the resonators are within the band gap or deaf bands. Realization of a high quality factor micromechanical ring resonator with minimized support loss is expected.
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Reducing support loss in micromechanical ring resonators using phononic band-gap structures
International Nuclear Information System (INIS)
Hsu, Feng-Chia; Huang, Tsun-Che; Wang, Chin-Hung; Chang, Pin; Hsu, Jin-Chen
2011-01-01
In micromechanical resonators, energy loss via supports into the substrates may lead to a low quality factor. To eliminate the support loss, in this paper a phononic band-gap structure is employed. We demonstrate a design of phononic-crystal (PC) strips used to support extensional wine-glass mode ring resonators to increase the quality factor. The PC strips are introduced to stop elastic-wave propagation by the band-gap and deaf-band effects. Analyses of resonant characteristics of the ring resonators and the dispersion relations, eigenmodes, and transmission properties of the PC strips are presented. With the proposed resonator architecture, the finite-element simulations show that the leaky power is effectively reduced and the stored energy inside the resonators is enhanced simultaneously as the operating frequencies of the resonators are within the band gap or deaf bands. Realization of a high quality factor micromechanical ring resonator with minimized support loss is expected.
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Vortex rings in classical and quantum systems
International Nuclear Information System (INIS)
Barenghi, C F; Donnelly, R J
2009-01-01
The study of vortex rings has been pursued for decades and is a particularly difficult subject. However, the discovery of quantized vortex rings in superfluid helium has greatly increased interest in vortex rings with very thin cores. While rapid progress has been made in the simulation of quantized vortex rings, there has not been comparable progress in laboratory studies of vortex rings in a viscous fluid such as water. This article overviews the history and current frontiers of classical and quantum vortex rings. After introducing the classical results, this review discusses thin-cored vortex rings in superfluid helium in section 2, and recent progress in understanding vortex rings of very thin cores propagating in water in section 3. (invited paper)
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Spin-dependent heat and thermoelectric currents in a Rashba ring coupled to a photon cavity
Abdullah, Nzar Rauf; Tang, Chi-Shung; Manolescu, Andrei; Gudmundsson, Vidar
2018-01-01
Spin-dependent heat and thermoelectric currents in a quantum ring with Rashba spin-orbit interaction placed in a photon cavity are theoretically calculated. The quantum ring is coupled to two external leads with different temperatures. In a resonant regime, with the ring structure in resonance with the photon field, the heat and the thermoelectric currents can be controlled by the Rashba spin-orbit interaction. The heat current is suppressed in the presence of the photon field due to contribution of the two-electron and photon replica states to the transport while the thermoelectric current is not sensitive to changes in parameters of the photon field. Our study opens a possibility to use the proposed interferometric device as a tunable heat current generator in the cavity photon field.
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Laparoscopic appendicectomy using endo-ring applicator and fallope rings
International Nuclear Information System (INIS)
Ali, Iyoob V; Maliekkal, Joji I
2009-01-01
Wider adoption of laparoscopic appendicectomy (LA) is limited by problems in securing the appendiceal base as well as the cost and the duration compared with the open procedure. The objective of this study was to assess the feasibility and efficacy of a new method for securing the appendiceal base in LA, so as to make the entire procedure simpler and cheaper, and hence, more popular. Twenty-five patients who were candidates for appendicectomy (emergency as well as elective) and willing for the laparoscopic procedure were selected for this study. Ports used were 10 mm at the umbilicus, 5 mm at the lower right iliac fossa, and 10 mm at the left iliac fossa. Extremely friable, ruptured, or turgid organs of diameters larger than 8 mm were excluded from the study. The mesoappendix was divided close to the appendix by diathermy. Fallope rings were applied to the appendiceal base using a special ring applicator, and the appendix was divided and extracted through the lumen of the applicator. The procedure was successful in 23 (92%) cases, and the mean duration of the procedure was 20 minutes (15-32 minutes). There were no procedural complications seen during a median follow-up of two weeks. The equipment and rings were cheaper when compared with that of the standard methods of securing the base of the appendix. LA using fallope rings is a safe, simple, easy-to-learn, and economically viable method. (author)
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International Nuclear Information System (INIS)
Moore, M.S.; Koehler, P.E.; Michaudon, A.; Schelberg, A.; Danon, Y.; Block, R.C.; Slovacek, R.E.; Hoff, R.W.; Lougheed, R.W.
1990-01-01
In November 1989, we carried out a measurement of the fission cross section of 247 Cm, 250 Cf, and 254 Es on the Rensselaer Intense Neutron Source (RINS) at Rensselaer Polytechnic Institute (RPI). In July 1990, we carried out a second measurement, using the same fission chamber and electronics, in beam geometry at the Los Alamos Neutron Scattering Center (LANSCE) facility. Using the relative count rates observed in the two experiments, and the flux-enhancement factors determined by the RPI group for a lead slowing-down spectrometer compared to beam geometry, we can assess the performance of a spectrometer similar to RINS, driven by the Proton Storage Ring (PSR) at the Los Alamos National Laboratory. With such a spectrometer, we find that is is feasible to make measurements with samples of 1 ng for fission 1 μg for capture, and of isotopes with half-lives of tens of minutes. It is important to note that, while a significant amount of information can be obtained from the low resolution RINS measurement, a definitive determination of average properties, including the level density, requires that the resonance structure be resolved. 12 refs., 5 figs., 3 tabs
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Energy Technology Data Exchange (ETDEWEB)
Moore, M.S.; Koehler, P.E.; Michaudon, A.; Schelberg, A. (Los Alamos National Lab., NM (USA)); Danon, Y.; Block, R.C.; Slovacek, R.E. (Rensselaer Polytechnic Inst., Troy, NY (USA)); Hoff, R.W.; Lougheed, R.W. (Lawrence Livermore National Lab., CA (USA))
1990-01-01
In November 1989, we carried out a measurement of the fission cross section of {sup 247}Cm, {sup 250}Cf, and {sup 254}Es on the Rensselaer Intense Neutron Source (RINS) at Rensselaer Polytechnic Institute (RPI). In July 1990, we carried out a second measurement, using the same fission chamber and electronics, in beam geometry at the Los Alamos Neutron Scattering Center (LANSCE) facility. Using the relative count rates observed in the two experiments, and the flux-enhancement factors determined by the RPI group for a lead slowing-down spectrometer compared to beam geometry, we can assess the performance of a spectrometer similar to RINS, driven by the Proton Storage Ring (PSR) at the Los Alamos National Laboratory. With such a spectrometer, we find that is is feasible to make measurements with samples of 1 ng for fission 1 {mu}g for capture, and of isotopes with half-lives of tens of minutes. It is important to note that, while a significant amount of information can be obtained from the low resolution RINS measurement, a definitive determination of average properties, including the level density, requires that the resonance structure be resolved. 12 refs., 5 figs., 3 tabs.
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Directory of Open Access Journals (Sweden)
Elysa Nur Safrida
2017-04-01
Full Text Available Background Central obesity has been associated with a high risk of insulin resistance. Waist circumference and waist-to-height ratio are anthropometric indices for determining central obesity and have been associated with increased blood pressure, cholesterol, and insulin levels. In adults, fat distribution around the waist is a valid predictor of glycated hemoglobin (HbA1clevels, and is currently recommended by experts as a diagnostic tool for diabetes. Central obesity measurement has advantages over fasting blood glucose and oral glucose tolerance tests, as it is simple and inexpensive to perform. Objective To assess for correlations between HbA1c level and waist circumference as well as waist-to-height ratio and to assess factors potentially associated with HbA1c levels in overweight and obese adolescents. Methods This cross-sectional study was done in four junior high schools in Yogyakarta, which were obtained by cluster sampling. Overweight and obese students who were generally healthy were included in the study. Subjects underwent waist circumference and waist-to-height ratio measurements, as well as blood tests for HbA1clevels. Results Sixty-seven children participated in the study, with 48 girls (71.6% and 19 boys (28.4%. Waist circumference and HbA1c levels were not significantly associated (r=0.178; P=0.15. However, waist-to-height ratio and HbA1c levels had a weak positive correlation (r=0.21; P=0.04. Linear regression analysis revealed that waist-to-height ratio had a significant association with HbA1c level (P=0.02, but age, sex, and nutritional status did not. Conclusion Waist-to-height ratio is correlated with HbA1c levels in overweight and obese adolescents.
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Albrecht, Sandra S; Mayer-Davis, Elizabeth; Popkin, Barry M
2017-07-01
For the same body mass index (BMI) level, waist circumference (WC) is higher in more recent years. How this impacts diabetes and prediabetes prevalence in the United States and for different race/ethnic groups is unknown. We examined prevalence differences in diabetes and prediabetes by BMI over time, investigated whether estimates were attenuated after adjusting for waist circumference, and evaluated implications of these patterns on race/ethnic disparities in glycemic outcomes. Data came from 12 614 participants aged 20 to 74 years from the National Health and Nutrition Examination Surveys (1988-1994 and 2007-2012). We estimated prevalence differences in diabetes and prediabetes by BMI over time in multivariable models. Relevant interactions evaluated race/ethnic differences. Among normal, overweight, and class I obese individuals, there were no significant differences in diabetes prevalence over time. However, among individuals with class II/III obesity, diabetes prevalence rose 7.6 percentage points in 2007-2012 vs 1988-1994. This estimate was partly attenuated after adjustment for mean waist circumference but not mean BMI. For prediabetes, prevalence was 10 to 13 percentage points higher over time at lower BMI values, with minimal attenuation after adjustment for WC. All patterns held within race/ethnic groups. Diabetes disparities among blacks and Mexican Americans relative to whites remained in both periods, regardless of BMI, and persisted after adjustment for WC. Diabetes prevalence rose over time among individuals with class II/III obesity and may be partly due to increasing waist circumference. Anthropometric measures did not appear to account for temporal increases in prediabetes, nor did they attenuate race/ethnic disparities in diabetes. Reasons underlying these trends require further investigation. Copyright © 2017 John Wiley & Sons, Ltd.
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Takamura, Toshinari; Kita, Yuki; Nakagen, Masatoshi; Sakurai, Masaru; Isobe, Yuki; Takeshita, Yumie; Kawai, Kohzo; Urabe, Takeshi; Kaneko, Shuichi
2017-07-01
To test the hypothesis that preserved muscle mass is protective against obesity-associated insulin resistance and metabolic abnormalities, we analyzed the relationship of lean body mass and computed tomography-assessed sectional areas of specific skeletal muscles with insulin resistance and metabolic abnormalities in a healthy cohort. A total of 195 subjects without diabetes who had completed a medical examination were included in this study. Various anthropometric indices such as circumferences of the arm, waist, hip, thigh, and calf were measured. Body composition (fat and lean body mass) was determined by bioelectrical impedance analysis. Sectional areas of specific skeletal muscles (iliopsoas, erector spinae, gluteus, femoris, and rectus abdominis muscles) were measured using computed tomography. Fat and lean body mass were significantly correlated with metabolic abnormalities and insulin resistance indices. When adjusted by weight, relationships of fat and lean body mass with metabolic parameters were mirror images of each other. The weight-adjusted lean body mass negatively correlated with systolic and diastolic blood pressures; fasting plasma glucose, HbA1c, alanine aminotransferase, and triglyceride, and insulin levels; and hepatic insulin resistance indices, and positively correlated with HDL-cholesterol levels and muscle insulin sensitivity indices. Compared with weight-adjusted lean body mass, weight-adjusted sectional areas of specific skeletal muscles showed similar, but not as strong, correlations with metabolic parameters. Among anthropometric measures, the calf circumference best reflected lean body mass, and weight-adjusted calf circumference negatively correlated with metabolic abnormalities and insulin resistance indices. Weight-adjusted lean body mass and skeletal muscle area are protective against weight-associated insulin resistance and metabolic abnormalities. The calf circumference reflects lean body mass and may be useful as a protective
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SMARANDACHE NON-ASSOCIATIVE RINGS
Vasantha, Kandasamy
2002-01-01
An associative ring is just realized or built using reals or complex; finite or infinite by defining two binary operations on it. But on the contrary when we want to define or study or even introduce a non-associative ring we need two separate algebraic structures say a commutative ring with 1 (or a field) together with a loop or a groupoid or a vector space or a linear algebra. The two non-associative well-known algebras viz. Lie algebras and Jordan algebras are mainly built using a vecto...
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International Nuclear Information System (INIS)
Schuch, R.
1987-01-01
A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs
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International Nuclear Information System (INIS)
1983-12-01
The conceptual design of a moving ring reactor ''Karin-1'' has been carried out to advance fusion system design, to clarify the research and development problems, and to decide their priority. In order to attain these objectives, a D-T reactor with tritium breeding blanket is designed, a commercial reactor with net power output of 500 MWe is designed, the compatibility of plasma physics with fusion engineering is demonstrated, and some other guideline is indicated. A moving ring reactor is composed mainly of three parts. In the first formation section, a plasma ring is formed and heated up to ignition temperature. The plasma ring of compact torus is transported from the formation section through the next burning section to generate fusion power. Then the plasma ring moves into the last recovery section, and the energy and particles of the plasma ring are recovered. The outline of a moving ring reactor ''Karin-1'' is described. As a candidate material for the first wall, SiC was adopted to reduce the MHD effect and to minimize the interaction with neutrons and charged particles. The thin metal lining was applied to the SiC surface to solve the problem of the compatibility with lithium blanket. Plasma physics, the engineering aspect and the items of research and development are described. (Kako, I.)
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Tinkering at the main-ring lattice
Energy Technology Data Exchange (ETDEWEB)
Ohnuma, S.
1982-08-23
To improve production of usable antiprotons using the proton beam from the main ring and the lossless injection of cooled antiprotons into the main ring, modifications of the main ring lattice are recommended.
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Schurmans, C?line; De Baetselier, Irith; Kestelyn, Evelyne; Jespers, Vicky; Delvaux, Th?r?se; Agaba, Stephen K; van Loen, Harry; Menten, Joris; van de Wijgert, Janneke; Crucitti, Tania
2015-01-01
Background Research is ongoing to develop multipurpose vaginal rings to be used continuously for contraception and to prevent Human Immunodeficiency Virus (HIV) infection. Contraceptive vaginal rings (CVRs) are available in a number of countries and are most of the time used intermittently i.e. three weeks out of a 4-week cycle. Efficacy trials with a dapivirine-containing vaginal ring for HIV prevention are ongoing and plans to develop multi-purpose vaginal rings for prevention of both HIV a...
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Rubincam, David P.
2013-01-01
The thermal expansion and contraction of ring particles orbiting a planet or asteroid can cause secular orbit evolution. This effect, called here the thermal expansion effect, depends on ring particles entering and exiting the shadow of the body they orbit. A particle cools off in the shadow and heats up again in the sunshine, suffering thermal contraction and expansion. The changing cross-section it presents to solar radiation pressure plus time lags due to thermal inertia lead to a net along-track force. The effect causes outward drift for rocky particles. For the equatorial orbits considered here, the thermal expansion effect is larger than Poynting-Robertson drag in the inner solar system for particles in the size range approx. 0.001 - 0.02 m. This leads to a net increase in the semimajor axis from the two opposing effects at rates ranging from approx. 0.1 R per million years for Mars to approx. 1 R per million years for Mercury, for distances approx. 2R from the body, where R is the body's radius. Asteroid 243 Ida has approx. 10 R per million years, while a hypothetical Near-Earth Asteroid (NEA) can have faster rates of approx. 0.5 R per thousand years, due chiefly to its small radius compared to the planets. The thermal expansion effect weakens greatly at Jupiter and is overwhelmed by Poynting-Robertson for icy particles orbiting Saturn. Meteoroids in eccentric orbits about the Sun also suffer the thermal expansion effect, but with only approx. 0.0003e2 AU change in semimajor axis over a million years for a 2 m meteoroid orbiting between Mercury and Earth.
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Pyrimidine-pyridine ring interconversion
Plas, van der H.C.
2003-01-01
This chapter discusses the pyrimidine-to-pyridine ring transformation and pyridine-to-pyrimidine ring transformation. In nucleophile-induced pyrimidine-to-pyridine rearrangements, two types of reactions can be distinguished depending on the structure of the nucleophile: (1) reactions in which the
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Speckle reduction in digital holography with resampling ring masks
Zhang, Wenhui; Cao, Liangcai; Jin, Guofan
2018-01-01
One-shot digital holographic imaging has the advantages of high stability and low temporal cost. However, the reconstruction is affected by the speckle noise. Resampling ring-mask method in spectrum domain is proposed for speckle reduction. The useful spectrum of one hologram is divided into several sub-spectra by ring masks. In the reconstruction, angular spectrum transform is applied to guarantee the calculation accuracy which has no approximation. N reconstructed amplitude images are calculated from the corresponding sub-spectra. Thanks to speckle's random distribution, superimposing these N uncorrelated amplitude images would lead to a final reconstructed image with lower speckle noise. Normalized relative standard deviation values of the reconstructed image are used to evaluate the reduction of speckle. Effect of the method on the spatial resolution of the reconstructed image is also quantitatively evaluated. Experimental and simulation results prove the feasibility and effectiveness of the proposed method.
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Electron beam cooling at a magnetic storage ring, TARN II, and an electrostatic storage ring
International Nuclear Information System (INIS)
Tanabe, Tetsumi
2006-01-01
At the High Energy Accelerator Research Organization (KEK), a magnetic storage ring, TARN II, with an electron cooler was operated from 1989 to 1999, while an electrostatic storage ring with a small electron cooler has been operational since 2000. In this paper, the electron cooling at TARN II and the electrostatic storage ring is described. (author)
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International Nuclear Information System (INIS)
Barber, D.P.; Vogt, M.
2006-12-01
Here, and in a sequel, we invoke the invariant spin field to provide an in-depth study of spin motion at and near low order orbital resonances in a simple model for the effects of vertical betatron motion in a storage ring with Siberian Snakes. This leads to a clear understanding, within the model, of the behaviour of the beam polarization at and near so-called snake resonances in proton storage rings. (orig.)
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Redox shuttles having an aromatic ring fused to a 1,1,4,4-tetrasubstituted cyclohexane ring
Weng, Wei; Zhang, Zhengcheng; Amine, Khalil
2015-12-01
An electrolyte includes an alkali metal salt; an aprotic solvent; and a redox shuttle additive including an aromatic compound having at least one aromatic ring fused with at least one non-aromatic ring, the aromatic ring having two or more oxygen or phosphorus-containing substituents.
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Xu, Hongtao; Tang, Huanyu; Feng, Huijin; Li, Yuanchao
2014-02-01
Triptolide is a diterpene triepoxide natural product isolated from Tripterygium wilfordii Hook F, a traditional Chinese medicinal herb. Triptolide has previously been shown to possess antitumor, anti-inflammatory, immunosuppressive, and antifertility activities. Earlier reports suggested that the five-membered unsaturated lactone ring (D ring) is essential for potent cytotoxicity, however, to the best of our knowledge, systematic structure-activity relationship studies have not yet been reported. Here, four types of D ring-modified triptolide analogues were designed, synthesized and evaluated against human ovarian (SKOV-3) and prostate (PC-3) carcinoma cell lines. The results suggest that the D ring is essential to potency, however it can be modified, for example to C18 hydrogen bond acceptor and/or donor furan ring analogues, without complete loss of cytotoxic activity. Interestingly, evaluation of the key series of C19 analogues showed that this site is exquisitely sensitive to polarity. Together, these results will guide further optimization of this natural product lead compound for the development of potent and potentially clinically useful triptolide analogues. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Auto-production of biosurfactants reverses the coffee ring effect in a bacterial system
Sempels, Wouter; de Dier, Raf; Mizuno, Hideaki; Hofkens, Johan; Vermant, Jan
2013-04-01
The deposition of material at the edge of evaporating droplets, known as the ‘coffee ring effect’, is caused by a radially outward capillary flow. This phenomenon is common to a wide array of systems including colloidal and bacterial systems. The role of surfactants in counteracting these coffee ring depositions is related to the occurrence of local vortices known as Marangoni eddies. Here we show that these swirling flows are universal, and not only lead to a uniform deposition of colloids but also occur in living bacterial systems. Experiments on Pseudomonas aeruginosa suggest that the auto-production of biosurfactants has an essential role in creating a homogeneous deposition of the bacteria upon drying. Moreover, at biologically relevant conditions, intricate time-dependent flows are observed in addition to the vortex regime, which are also effective in reversing the coffee ring effect at even lower surfactant concentrations.
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Two dynamin-like proteins stabilize FtsZ rings during Streptomyces sporulation.
Schlimpert, Susan; Wasserstrom, Sebastian; Chandra, Govind; Bibb, Maureen J; Findlay, Kim C; Flärdh, Klas; Buttner, Mark J
2017-07-25
During sporulation, the filamentous bacteria Streptomyces undergo a massive cell division event in which the synthesis of ladders of sporulation septa convert multigenomic hyphae into chains of unigenomic spores. This process requires cytokinetic Z-rings formed by the bacterial tubulin homolog FtsZ, and the stabilization of the newly formed Z-rings is crucial for completion of septum synthesis. Here we show that two dynamin-like proteins, DynA and DynB, play critical roles in this process. Dynamins are a family of large, multidomain GTPases involved in key cellular processes in eukaryotes, including vesicle trafficking and organelle division. Many bacterial genomes encode dynamin-like proteins, but the biological function of these proteins has remained largely enigmatic. Using a cell biological approach, we show that the two Streptomyces dynamins specifically localize to sporulation septa in an FtsZ-dependent manner. Moreover, dynamin mutants have a cell division defect due to the decreased stability of sporulation-specific Z-rings, as demonstrated by kymographs derived from time-lapse images of FtsZ ladder formation. This defect causes the premature disassembly of individual Z-rings, leading to the frequent abortion of septum synthesis, which in turn results in the production of long spore-like compartments with multiple chromosomes. Two-hybrid analysis revealed that the dynamins are part of the cell division machinery and that they mediate their effects on Z-ring stability during developmentally controlled cell division via a network of protein-protein interactions involving DynA, DynB, FtsZ, SepF, SepF2, and the FtsZ-positioning protein SsgB.
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The role of substorms in the formation of the ring current
International Nuclear Information System (INIS)
Rostoker, G.
1996-01-01
It has long been recognized that the formation of the terrestrial ring current is accompanied by strong substorm expansive phase activity in the auroral oval. While large amplitude substorm activity seems to be a prerequisite for ring current formation to take place, it has long been puzzling as to why some large amplitude substorm activity in the auroral oval is not associated with significant ring current development. In this paper I shall outline the basis for the renovated boundary layer dynamics model of magnetospheric substorms showing how the onset of the substorm expansive phase can be associated with a sudden decrease in shielding space charge in the region of the near-Earth plasma sheet threaded by Region 2 field-aligned currents. I shall suggest that an episode of sufficiently large southward IMF lasting over a sufficiently lengthy period of time can lead to a sequence of substorm expansive phases, each one being initiated closer to the Earth than the previous one. Each expansive phase is attributed to a sudden decrease in radially localized cross-tail current (viz. a decrease in shielding space charge) and with each onset the inner edge of the plasma sheet moves inward. The inductive electric field associated with each crosstail current decrease is responsible for the acceleration of already energetic particles to energies of significance for ring current formation. Only when the inner edge of the crosstail current is sufficiently close to the Earth do the acceleration processes associated with substorm onset produce a long lived ring current. copyright 1996 American Institute of Physics
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Rushton, J Philippe; Vernon, Philip A; Bons, Trudy Ann
2007-04-22
We test the hypothesis that polymorphisms of the brain regulator genes MCPH1 and ASPM contribute to variations in human brain size and its correlates. We measured general mental ability, head circumference and social intelligence in 644 Canadian adults (496 Caucasians, 36 Orientals, 84 Mixed Race/Other and 28 Blacks; 257 men and 387 women). The gene polymorphisms were assessed from buccal DNA; mental ability by Wonderlic Personnel Test and Multidimensional Aptitude Battery; head circumference by stretchless tape; and social intelligence by prosocial attitude questionnaires. Although all measures were construct valid and the allele frequencies showed expected population differences, no relationship was found between the genes and any of the criteria. Among Caucasian 18-25 year olds, for example, the two mental ability tests correlated with each other (r=0.78, N=476, p<0.001), with head circumference (r=0.17, N=182, p<0.05) and with prosocial attitudes (r=0.23, N=182, p<0.001).
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Männer, R.
1989-12-01
This paper describes a systolic array processor for a ring image Cherenkov counter which is capable of identifying pairs of electron circles with a known radius and a certain minimum distance within 15 μs. The processor is a very flexible and fast device. It consists of 128 x 128 processing elements (PEs), where one PE is assigned to each pixel of the image. All PEs run synchronously at 40 MHz. The identification of electron circles is done by correlating the detector image with the proper circle circumference. Circle centers are found by peak detection in the correlation result. A second correlation with a circle disc allows circles of closed electron pairs to be rejected. The trigger decision is generated if a pseudo adder detects at least two remaining circles. The device is controlled by a freely programmable sequencer. A VLSI chip containing 8 x 8 PEs is being developed using a VENUS design system and will be produced in 2μ CMOS technology.
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International Nuclear Information System (INIS)
Maenner, R.
1989-01-01
This paper describes a systolic array processor for a ring image Cherenkov counter which is capable of identifying pairs of electron circles with a known radius and a certain minimum distance within 15 μs. The processor is a very flexible and fast device. It consists of 128x128 processing elements (PEs), where one PE is assigned to each pixel of the image. All PEs run synchronously at 40 MHz. The identification of electron circles is done by correlating the detector image with the proper circle circumference. Circle centers are found by peak detection in the correlation result. A second correlation with a circle disc allows circles of closed electron pairs to be rejected. The trigger decision is generated if a pseudo adder detects at least two remaining circles. The device is controlled by a freely programmable sequencer. A VLSI chip containing 8x8 PEs is being developed using a VENUS design system and will be produced in 2μ CMOS technology. (orig.)
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Recent results on lead-ion accumulation in LEAR for the LHC
International Nuclear Information System (INIS)
Baird, S.; Bosser, J.; Broere, J.; Carli, C.; Chanel, M.; Hill, C.; Ley, R.; Lombardi, A.; Maccaferri, R.; Maury, S.; Meshkov, I.; Moehl, D.; Molinari, G.; Mulder, H.; Syresin, E.; Tanke, E.; Tranquille, G.; Varenne, F.; Vretenar, M.
1997-01-01
To prepare dense bunches of lead ions for the LHC it has been proposed to accumulate the 4.2 MeV/u linac beam in a storage ring with electron cooling. A series of experiments is being performed in the low-energy ring LEAR to test this technique. First results were already reported at the Beam Crystallisation Workshop in Erice in November 1995. Two more recent runs to complement these investigations were concerned with: further study of the beam lifetime; the dependence of the cooling time on optical settings of the storage ring and on neutralization of the electron beam: and tests in view of multiturn injection. New results obtained in these two runs in December 1995 and in April 1996 are discussed in this contribution. (orig.)
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Magnetic ring for stripping enhancement
International Nuclear Information System (INIS)
Selph, F.
1992-10-01
A ring designed to recycle ions through a stripping medium offers the possibility for increasing output of the desired charge state by up to 4x. This could be a very important component of a Radioactive Nuclear Beam Facility. In order for such a ring to work effectively it must satisfy certain design conditions. These include achromaticity at the stripper, a dispersed region for an extraction magnet, and a number of first and higher order optics constraints which are necessary to insure that the beam emittance is not degraded unduly by the ring. An example is given of a candidate design of a stripping ring
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Solar system history as recorded in the Saturnian ring structure
International Nuclear Information System (INIS)
Alfven, H.
1983-04-01
The paper is based on Holbergs analysis of the Voyager photographs in both reflected and transparent light, combined with occulation data of stars seen through the rings. Besides rapidly varying phenomena (spokes, braided ring, etc.), which according to Mendis are due to gravito-electromagnetic effects, the ring consists of a bulk structure, a fine structure, and also a hyperfine structure, showing more than 10000 ringlets. The large number of ringlets can be explained by the Baxter-Thompson negative diffusion. This gives the ringlets a stability which makes it possible to interprete them as fossils, which originated at cosmogonic times. It is shown that the bulk structure can be explained by the combined cosmogonic shadows of the satellites Mimas, Janus (co-orbiting satellites) and the Shepherd satellites. This structure originated at the transition from the plasma phase to the planetesimal phase (which probably took place 4-5 times 10 9 years ago). Further, Holberg has discovered that the shadows are not simple void regions but exhibit a certain characteristic signature. This is not yet understood theoretically. Parts of the fine structure are explained by Holberg as resonances with the satellites. Parts are here interpreted as cosmogonic shadow effects. However, there are a number of ringlets which can neither be explained by cosmogonic nor by resonance effects. The most important conclusion is that an analysis of the ring data is liekly to lead to a reconstruction of the plasma-planetesimal transition with an accuracy of a few percent. (author)
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Estruch, Ramon; Martínez-González, Miguel Angel; Corella, Dolores; Salas-Salvadó, Jordi; Fitó, Montserrat; Chiva-Blanch, Gemma; Fiol, Miquel; Gómez-Gracia, Enrique; Arós, Fernando; Lapetra, José; Serra-Majem, Lluis; Pintó, Xavier; Buil-Cosiales, Pilar; Sorlí, José V; Muñoz, Miguel A; Basora-Gallisá, Josep; Lamuela-Raventós, Rosa María; Serra-Mir, Mercè; Ros, Emilio
2016-08-01
Because of the high density of fat, high-fat diets are perceived as likely to lead to increased bodyweight, hence health-care providers are reluctant to recommend them to overweight or obese individuals. We assessed the long-term effects of ad libitum, high-fat, high-vegetable-fat Mediterranean diets on bodyweight and waist circumference in older people at risk of cardiovascular disease, most of whom were overweight or obese. PREDIMED was a 5 year parallel-group, multicentre, randomised, controlled clinical trial done in primary care centres affiliated to 11 hospitals in Spain. 7447 asymptomatic men (aged 55-80 years) and women (aged 60-80 years) who had type 2 diabetes or three or more cardiovascular risk factors were randomly assigned (1:1:1) with a computer-generated number sequence to one of three interventions: Mediterranean diet supplemented with extra-virgin olive oil (n=2543); Mediterranean diet supplemented with nuts (n=2454); or a control diet (advice to reduce dietary fat; n=2450). Energy restriction was not advised, nor was physical activity promoted. In this analysis of the trial, we measured bodyweight and waist circumference at baseline and yearly for 5 years in the intention-to-treat population. The PREDIMED trial is registered with ISRCTN.com, number ISRCTN35739639. After a median 4·8 years (IQR 2·8-5·8) of follow-up, participants in all three groups had marginally reduced bodyweight and increased waist circumference. The adjusted difference in 5 year changes in bodyweight in the Mediterranean diet with olive oil group was -0·43 kg (95% CI -0·86 to -0·01; p=0·044) and in the nut group was -0·08 kg (-0·50 to 0·35; p=0·730), compared with the control group. The adjusted difference in 5 year changes in waist circumference was -0·55 cm (-1·16 to -0·06; p=0·048) in the Mediterranean diet with olive oil group and -0·94 cm (-1·60 to -0·27; p=0·006) in the nut group, compared with the control group. A long-term intervention with an
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Sadhukhan, Sanjoy Kr; Chatterjee, Chitra; Shrivastava, Prabha; Sardar, Jadav Chandra; Joardar, Gautam Kr; Lahiri, Saibendu
2010-09-01
This institution-based cross-sectional observational validation study was conducted in the immunisation clinic of North Bengal Medical College and Hospital, Sushrutanagar. The objective was to identify the validity characteristics of mid arm circumference to detect protein energy malnutrition among 8-11 months infants and to find out a suitable cut-off value if any. Study variables were age, sex, body weight and mid arm circumference. Mid arm circumference was validated against weight for age criteria (gold standard) of malnutrition. The mean mid arm circumference of the infants was found to be almost constant with only about 2.22% change over 4 months, signifying that single cut-off point can be used to detect protein energy malnutrition. Mid arm circumference values from 13.0 to 12.5 cm were found to have the highest accuracy to detect protein energy malnutrition (about 86%). The cut-off values of 12.5 and 12.6 cm were noted to have a sensitivity and specificity of about 52% and 96% respectively, a false negativity of 48% but a false positivity of only 4%. Receiver operating characteristics curve detected 12.5(12.6) cm as the best diagnostic cut-off point which can detect more than 50% of the malnourished babies with very little false positivity/misdiagnosis (only 4%). A simple measuring tape with some reorientation of the health workers can detect the beginning of childhood malnutrition.
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A first course in noncommutative rings
Lam, T Y
2001-01-01
A First Course in Noncommutative Rings, an outgrowth of the author's lectures at the University of California at Berkeley, is intended as a textbook for a one-semester course in basic ring theory. The material covered includes the Wedderburn-Artin theory of semisimple rings, Jacobson's theory of the radical, representation theory of groups and algebras, prime and semiprime rings, local and semilocal rings, perfect and semiperfect rings, etc. By aiming the level of writing at the novice rather than the connoisseur and by stressing th the role of examples and motivation, the author has produced a text that is suitable not only for use in a graduate course, but also for self- study in the subject by interested graduate students. More than 400 exercises testing the understanding of the general theory in the text are included in this new edition.
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DEFF Research Database (Denmark)
Lanfer, Anne; Mehlig, Kirsten; Heitmann, Berit L
2014-01-01
Accumulating evidence consistently shows that small hip circumference (HC) is related to increased risk of cardiovascular disease (CVD), coronary heart disease, diabetes, and premature death in women. This study aims to clarify whether this inverse association can be found in both normal...
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Design of Piston Ring Friction Tester Apparatus
DEFF Research Database (Denmark)
Klit, Peder
2006-01-01
One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing the frictio......One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing...... the frictional behavior of a piston ring correctly is knowledge about the amount of lubricant present. For piston rings the external load may be established by measuring the pressure distribution, i.e. the pressure drop in the piston ring package. Speed and temperature may also be established. The amount...... available is reflected in the friction absorbed in the bearing. The following properties will be measured: Oil fillm thickness - along liner (axial variation), oil film thickness - along piston ring (circumferential variation), piston tilt, temperature of piston rings and liner, pressure at piston lands...
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Study for ILC Damping Ring at KEKB
Energy Technology Data Exchange (ETDEWEB)
Flanagan, J.W.; Fukuma, H.; Kanazawa, K.I.; Koiso, H.; Masuzawa, M.; Ohmi, Kazuhito; Ohnishi, Y.; Oide, Katsunobu; Suetsugu, Y.; Tobiyama, M.; /KEK, Tsukuba; Pivi, M.; /SLAC
2011-11-04
ILC damping ring consists of very low emittance electron and positron storage rings. It is necessary for ILC damping ring to study electron cloud effects in such low emittance positron ring. We propose a low emittance operation of KEKB to study the effects.
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International Nuclear Information System (INIS)
Kim, Eun-San
2003-01-01
This paper shows the results of a numerical study of the impedance in the Accelerator Test Facility damping ring. The longitudinal impedance in the damping ring is shown to be inductive. It is shown that the total impedance |Z || /n| is 0.23 Ω and the inductance is L = 14 nH. In the extremely low emittance beam of the damping ring, bunch lengthening is caused by both the effects of potential-well distortion and intra-beam scattering. In this paper, the bunch-lengthening due to the ring impedance is numerically investigated, and the result shows qualitative agreement with the result of an analysis performed using the bunch-length measurement. With the calculated longitudinal impedance, the instability threshold in the damping ring is estimated to be a bunch population of 3.3 x 10 10 by using both a Vlasov equation approach and a multi-particle tracking method.
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Coherent Synchrotron Radiation effect in damping rings
International Nuclear Information System (INIS)
Raubenheimer, T
2004-01-01
Coherent Synchrotron Radiation (CSR) can play an important role by not only increasing the energy spread and emittance of a beam, but also leading to a potential instability. Previous studies of the CSR induced longitudinal instability were carried out for the CSR impedance due to dipole magnets. In this paper, the instability due to the CSR impedance from a wiggler is studied assuming a large wiggler parameter K. The primary consideration is a low frequency microwave-like instability in the damping rings of several linear collider projects. The threshold is determined by the instability with the longest possible wavelength
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International Nuclear Information System (INIS)
Bhattacharyya, S; Das, N R
2012-01-01
In this paper, we study the oscillator strength and cross-section for intersubband optical transition in an n-type semiconductor quantum ring of cylindrical symmetry in the presence of an electric field perpendicular to the plane of the ring. The analysis is done considering Kane-type band non-parabolicity of the semiconductor and assuming that the polarization of the incident radiation is along the axis of the ring. The results show that the oscillator strength decreases and the transition energy increases with the electric field. The assumption of a parabolic band leads to an overestimation of the oscillator strength. The effects of the electric field, band non-parabolicity and relaxation time on absorption cross-section for intersubband transition in a semiconductor quantum ring are also shown. (paper)
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Skin patch and vaginal ring versus combined oral contraceptives for contraception.
Lopez, Laureen M; Grimes, David A; Gallo, Maria F; Stockton, Laurie L; Schulz, Kenneth F
2013-04-30
likely to have missed days of therapy (OR 0.36; 95% CI 0.25 to 0.51). Of four vaginal ring trials, one found ring users had more noncompliance (OR 3.99; 95% CI 1.87 to 8.52), while another showed more compliance with the regimen (OR 1.67; 95% CI 1.04 to 2.68).More patch users discontinued early than COC users. ORs from two meta-analyses were 1.59 (95% CI 1.26 to 2.00) and 1.56 (95% CI 1.18 to 2.06) and another trial showed OR 2.57 (95% CI 0.99 to 6.64). Patch users also had more discontinuation due to adverse events than COC users. Users of the norelgestromin-containing patch reported more breast discomfort, dysmenorrhea, nausea, and vomiting. In the levonorgestrel-containing patch trial, patch users reported less vomiting, headaches, and fatigue.Of 11 ring trials with discontinuation data, two showed the ring group discontinued less than the COC group: OR 0.32 (95% CI 0.16 to 0.66) and OR 0.52 (95% CI 0.31 to 0.88). Ring users were less likely to discontinue due to adverse events in one study (OR 0.32; 95% CI 0.15 to 0.70). Compared to the COC users, ring users had more vaginitis and leukorrhea but less vaginal dryness. Ring users also reported less nausea, acne, irritability, depression, and emotional lability than COC users.For cycle control, only one trial study showed a significant difference. Women in the patch group were less likely to have breakthrough bleeding and spotting. Seven ring studies had bleeding data; four trials showed the ring group generally had better cycle control than the COC group. Effectiveness was not significantly different for the methods compared. Pregnancy data were available from half of the patch trials but two-thirds of ring trials. The patch could lead to more discontinuation than the COC. The patch group had better compliance than the COC group. Compliance data came from half of the patch studies and one-third of the ring trials. Patch users had more side effects than the COC group. Ring users generally had fewer adverse events than
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Meinke, B. K.; Esposito, L. W.; Stewart, G.
2012-12-01
Saturn's F ring is the solar system's principal natural laboratory for direct observation of accretion and disruption processes. The ring resides in the Roche zone, where tidal disruption competes with self-gravity, which allows us to observe the lifecycle of moonlets. Just as nearby moons create structure at the B ring edge (Esposito et al. 2012) and the Keeler gap (Murray 2007), the F ring "shepherding" moons Prometheus and Pandora stir up ring material and create observably changing structures on timescales of days to decades. In fact, Beurle et al (2010) show that Prometheus makes it possible for "distended, yet gravitationally coherent clumps" to form in the F ring, and Barbara and Esposito (2002) predicted a population of ~1 km bodies in the ring. In addition to the observations over the last three decades, the Cassini Ultraviolet Imaging Spectrograph (UVIS) has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Seventeen of those 27 features are associated with clumps of ring material. Two features are opaque in occultation, which makes them candidates for solid objects, which we refer to as Moonlets. The 15 other features partially block stellar signal for 22 m to just over 3.7 km along the radial expanse of the occultation. Upon visual inspection of the occultation profile, these features resemble Icicles, thus we will refer to them as such here. The density enhancements responsible for such signal attenuations are likely due to transient clumping of material, evidence that aggregations of material are ubiquitous in the F ring. Our lengthy observing campaign reveals that Icicles are likely transient clumps, while Moonlets are possible solid objects. Optical depth is an indicator of clumping because more-densely aggregated material blocks more light; therefore, it is natural to imagine moonlets as later evolutionary stage of icicle, when looser clumps of material compact to form a feature that appears
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Nonlinear analysis of ring oscillator circuits
Ge, Xiaoqing
2010-06-01
Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.
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Nonlinear analysis of ring oscillator circuits
Ge, Xiaoqing; Arcak, Murat; Salama, Khaled N.
2010-01-01
Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.
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Quality Assurance Project Plan for Verification of Sediment Ecotoxicity Assessment Ring(SEA Ring)
The objective of the verification is to test the efficacy and ability of the Sediment Ecotoxicity Assessment Ring (SEA Ring) to evaluate the toxicity of contaminants in the sediment, at the sediment-water interface, and WC to organisms that live in those respective environments.
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Dynamical Evolution of Ring-Satellite Systems
Ohtsuki, Keiji
2005-01-01
The goal of this research was to understand dynamical processes related to the evolution of size distribution of particles in planetary rings and application of theoretical results to explain features in the present rings of giant planets. We studied velocity evolution and accretion rates of ring particles in the Roche zone. We developed a new numerical code for the evolution of ring particle size distribution, which takes into account the above results for particle velocity evolution and accretion rates. We also studied radial diffusion rate of ring particles due to inelastic collisions and gravitational encounters. Many of these results can be also applied to dynamical evolution of a planetesimal disk. Finally, we studied rotation rates of moonlets and particles in planetary rings, which would influence the accretional evolution of these bodies. We describe our key accomplishments during the past three years in more detail in the following.
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Head circumference in Iranian infants
Directory of Open Access Journals (Sweden)
Mohammad Esmaeili
2015-03-01
Full Text Available Introduction: Head circumference (HC measurement is one of the important parameter for diagnosis of neurological, developmental disorders and dysmorphic syndromes. Recognition of different disorders requires an understanding of normal variation for HC size, in particular, in infancy period with most rapid growth of the brain. Because of international and interracial standard chart differences about anthropometric indices, some differences from local to local, generation to generation and changes in ethnic mix of population and socioeconomic factors, periodic revolution of HC size is suggested. The aims of our study were presenting local HC standard for an Iranian infant population and comparison with the American national center of health statistics (NCHS charts accepted by WHO. Methods: 1003 subjects aged from birth to 24 months apparently healthy normal children enrolled randomly in this cross sectional study. HC size were measured and recorded. Tables and graphs were depicted by Excel Microsoft Office 2007. We use two tailed t-student test for statistical analysis. Results: The mean of HC size in boys was larger than girls. The curves were followed a similar pattern to NCHS based on a visual comparison. Overall our subjects in both sexes at birth time had smaller HC size than NCHS. In other ages our children had larger HC size than those of NCHS. Conclusion: Because of international and interracial difference of HC size. We recommend in each area of the world, local anthropometric indices are constructed and used clinically. In addition more extensive and longitudinally design comprehensive studies is suggested.
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Directory of Open Access Journals (Sweden)
Roel J T Mocking
Full Text Available BACKGROUND: Fatty acid (FA-alterations may mediate the mutual association between Major Depressive Disorder (MDD and cardiovascular disease (CVD. However, etiology of observed FA-alterations in MDD and CVD remains largely unclear. An interesting candidate may be a mutation in the fatty acid-binding protein 2 (FABP2-gene, because it regulates dietary FA-uptake. Therefore, we aimed to test the hypotheses that in MDD-patients the FABP2 Ala54Thr-polymorphism would be (I more prevalent than in sex- and age-matched controls, (II associated with observed alterations in FA-metabolism, and (III associated with CVD-risk factor waist circumference. METHODS: We measured concentrations of 29 different erythrocyte FAs, FABP2-genotype, and waist circumference in recurrent MDD-patients and matched never-depressed controls. RESULTS: FABP2-genotype distribution did not significantly differ between the 137 MDD-patients and 73 matched controls. However, patients with the Ala54Thr-polymorphism had (I higher concentrations of especially eicosadienoic acid (C20:2ω6; P=.009 and other 20-carbon FAs, and associated (II lower waist circumference (P=.019. In addition, FABP2-genotype effects on waist circumference in patients seemed (I mediated by its effect on C20:2ω6, and (II different from controls. CONCLUSIONS: Although Ala54Thr-polymorphism distribution was not associated with recurrent MDD, our results indicate that FABP2 may play a role in the explanation of observed FA-alterations in MDD. For Ala54Thr-polymorphism patients, potentially adaptive conversion of increased bioavailable dietary precursors into eicosadienoic acid instead of arachidonic acid might be related to a low waist circumference. Because this is the first investigation of these associations, replication is warranted, preferably by nutrigenetic studies applying lipidomics and detailed dietary assessment.
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Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.
2013-12-01
Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B ring. The gap moves at Kepler speed appropriate for its radial location. Radial offsets of the gap locations in UVIS occultations are consistent with an asymmetric propeller shape. The asymmetry of the observed shape is most likely a consequence of the strong surface mass density gradient, as the feature is located at an edge between
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Cosmic rings from colliding galaxies
Energy Technology Data Exchange (ETDEWEB)
Mitton, S
1976-11-18
Research on two ring galaxies has led to the proposal of an interaction model to account for the rings. It is envisaged that this class of galaxy is created when a compact galaxy crashes through the disc of a spiral galaxy. The results of a spectroscopic investigation of the galaxy known as the Cartwheel and of another ring galaxy 11 NZ 4 are discussed. The general picture of ring galaxies which emerges from these studies of a massive starry nucleus with a necklace of emitting gas and some spokes and along the spin axis of the wheel a small companion galaxy that is devoid of interstellar gas. An explanation of these properties is considered.
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CESR Conversion Damping Ring Studies of Electron Cloud Instabilities (CESR-TA)
International Nuclear Information System (INIS)
Rubin, David L.; Palmer, Mark A.
2011-01-01
In the International Linear Collider, two linear accelerators will accelerate bunches of positrons and electrons to over a hundred billion electron volts and collide them in a central detector. In order to obtain useful collision rates, the bunches, each containing twenty billion particles, must be compressed to a cross section of a few nanometers by a few hundred nanometers. In order to prepare these ultra high density bunches, damping rings (DRs) are employed before the linear accelerators. The DRs take the high emittance bunches that are provided by the electron and positron sources and, through the process of radiation damping, squeeze them into ultra low emittance beams that are ready for the main linear accelerators. In the damping rings, a number of effects can prevent the successful preparation of the beams. In the electron ring, an effect known as the fast ion instability can lead to beam growth and, in the positron ring, the build-up of an electron cloud (EC), which interacts with the circulating bunches, can produce the same effect. EC build-up and the subsequent interaction of the cloud with the positron beam in the DR have been identified as major risks for the successful construction of a linear collider. The CESRTA research program at the Cornell Electron Storage Ring (CESR) was developed in order to study the build-up of the EC, the details of its impact on ultra low emittance beams, as well as methods to mitigate the impact of the cloud. In the DR, the EC forms when synchrotron photons radiated from the circulating beam strike the walls of the vacuum chamber, resulting in the emission of photoelectrons. These low energy electrons can be accelerated across the vacuum chamber by the electric field of the beam, and strike the walls, causing the emission of secondary electrons. The secondary electrons are subsequently accelerated into the walls yet again via the same mechanism. The result is that the EC can rapidly begin to fill the vacuum chamber. In
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CESR Conversion Damping Ring Studies of Electron Cloud Instabilities (CESR-TA)
Energy Technology Data Exchange (ETDEWEB)
Rubin, David L.; Palmer, Mark A.
2011-08-02
In the International Linear Collider, two linear accelerators will accelerate bunches of positrons and electrons to over a hundred billion electron volts and collide them in a central detector. In order to obtain useful collision rates, the bunches, each containing twenty billion particles, must be compressed to a cross section of a few nanometers by a few hundred nanometers. In order to prepare these ultra high density bunches, damping rings (DRs) are employed before the linear accelerators. The DRs take the high emittance bunches that are provided by the electron and positron sources and, through the process of radiation damping, squeeze them into ultra low emittance beams that are ready for the main linear accelerators. In the damping rings, a number of effects can prevent the successful preparation of the beams. In the electron ring, an effect known as the fast ion instability can lead to beam growth and, in the positron ring, the build-up of an electron cloud (EC), which interacts with the circulating bunches, can produce the same effect. EC build-up and the subsequent interaction of the cloud with the positron beam in the DR have been identified as major risks for the successful construction of a linear collider. The CESRTA research program at the Cornell Electron Storage Ring (CESR) was developed in order to study the build-up of the EC, the details of its impact on ultra low emittance beams, as well as methods to mitigate the impact of the cloud. In the DR, the EC forms when synchrotron photons radiated from the circulating beam strike the walls of the vacuum chamber, resulting in the emission of photoelectrons. These low energy electrons can be accelerated across the vacuum chamber by the electric field of the beam, and strike the walls, causing the emission of secondary electrons. The secondary electrons are subsequently accelerated into the walls yet again via the same mechanism. The result is that the EC can rapidly begin to fill the vacuum chamber. In