Dielectronic recombination experiments at the storage rings: From the present CSR to the future HIAF

Science.gov (United States)

Huang, Z. K.; Wen, W. Q.; Xu, X.; Wang, H. B.; Dou, L. J.; Chuai, X. Y.; Zhu, X. L.; Zhao, D. M.; Li, J.; Ma, X. M.; Mao, L. J.; Yang, J. C.; Yuan, Y. J.; Xu, W. Q.; Xie, L. Y.; Xu, T. H.; Yao, K.; Dong, C. Z.; Zhu, L. F.; Ma, X.

2017-10-01

Dielectronic recombination (DR) experiments of highly charged ions at the storage rings have been developed as a precision spectroscopic tool to investigate the atomic structure as well as nuclear properties of stable and unstable nuclei. The DR experiment on lithium-like argon ions was successfully performed at main Cooler Storage Ring (CSRm) at Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex. The DR experiments on heavy highly charged ions and even radioactive ions are currently under preparation at the experimental Cooler Storage Ring (CSRe) at HIRFL. The current status of DR experiments at the CSRm and the preparation of the DR experiments at the CSRe are presented. In addition, an overview of DR experiments by employing an electron cooler and a separated ultra-cold electron target at the upcoming High Intensity heavy ion Accelerator Facility (HIAF) will be given.

Tree-ring-based snowfall record for cold arid western Himalaya, India since A.D. 1460

Science.gov (United States)

Yadav, Ram R.; Bhutiyani, Mahendra R.

2013-07-01

Understanding snowfall variations in high-elevation cold arid regions of the western Himalaya is important as snowmelt water is the main source of water to meet the scores of socioeconomic needs. The ground-based observational data, though limited to the last two decades, show decreasing snowfall, raising the concern of looming water scarcity in the region. The tree-ring data of Himalayan cedar from a network of six moisture-stressed sites, where snowmelt water is the sole source of soil moisture for tree growth, were used to develop the November-April snow water equivalent (SWE) extending back to A.D. 1460. The reconstruction revealed persistent severe droughts in the 1780s followed by the 1480s and relatively lesser magnitude droughts in the 1540s-1560s, 1740s, and early twentieth century. The pluvial conditions observed in 1948-1958 and 1986-1996 stand out over any other period of such duration. The SWE reconstruction revealed large-scale spatial coherence with the corresponding month's Palmer Drought Severity Index over the western Himalayan region. Significant relationship observed between SWE reconstruction and January-March Chenab River flow revealed its potential utility in understanding water resource availability in the long-term perspective.

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.

Utilization of Titanium Particle Impact Location to Validate a 3D Multicomponent Model for Cold Spray Additive Manufacturing

Science.gov (United States)

Faizan-Ur-Rab, M.; Zahiri, S. H.; King, P. C.; Busch, C.; Masood, S. H.; Jahedi, M.; Nagarajah, R.; Gulizia, S.

2017-12-01

Cold spray is a solid-state rapid deposition technology in which metal powder is accelerated to supersonic speeds within a de Laval nozzle and then impacts onto the surface of a substrate. It is possible for cold spray to build thick structures, thus providing an opportunity for melt-less additive manufacturing. Image analysis of particle impact location and focused ion beam dissection of individual particles were utilized to validate a 3D multicomponent model of cold spray. Impact locations obtained using the 3D model were found to be in close agreement with the empirical data. Moreover, the 3D model revealed the particles' velocity and temperature just before impact—parameters which are paramount for developing a full understanding of the deposition process. Further, it was found that the temperature and velocity variations in large-size particles before impact were far less than for the small-size particles. Therefore, an optimal particle temperature and velocity were identified, which gave the highest deformation after impact. The trajectory of the particles from the injection point to the moment of deposition in relation to propellant gas is visualized. This detailed information is expected to assist with the optimization of the deposition process, contributing to improved mechanical properties for additively manufactured cold spray titanium parts.

Precision ring rolling technique and application in high-performance bearing manufacturing

Directory of Open Access Journals (Sweden)

Hua Lin

2015-01-01

Full Text Available High-performance bearing has significant application in many important industry fields, like automobile, precision machine tool, wind power, etc. Precision ring rolling is an advanced rotary forming technique to manufacture high-performance seamless bearing ring thus can improve the working life of bearing. In this paper, three kinds of precision ring rolling techniques adapt to different dimensional ranges of bearings are introduced, which are cold ring rolling for small-scale bearing, hot radial ring rolling for medium-scale bearing and hot radial-axial ring rolling for large-scale bearing. The forming principles, technological features and forming equipments for three kinds of precision ring rolling techniques are summarized, the technological development and industrial application in China are introduced, and the main technological development trend is described.

Improving the Cold Temperature Properties of Tallow-Based Methyl Ester Mixtures Using Fractionation, Blending, and Additives

Science.gov (United States)

Elwell, Caleb

Beef tallow is a less common feedstock source for biodiesel than soy or canola oil, but it can have economic benefits in comparison to these traditional feedstocks. However, tallow methyl ester (TME) has the major disadvantage of poor cold temperature properties. Cloud point (CP) is an standard industry metric for evaluating the cold temperature performance of biodiesel and is directly related to the thermodynamic properties of the fuel's constituents. TME has a CP of 14.5°C compared with 2.3°C for soy methyl ester (SME) and -8.3°C for canola methyl ester (CME). In this study, three methods were evaluated to reduce the CP of TME: fractionation, blending with SME and CME, and using polymer additives. TME fractionation (i.e. removal of specific methyl ester constituents) was simulated by creating FAME mixtures to match the FAME profiles of fractionated TME. The fractionation yield was found to be highest at the eutectic point of methyl palmitate (MP) and methyl stearate (MS), which was empirically determined to be at a MP/(MP+MS) ratio of approximately 82%. Since unmodified TME has a MP/(MP+MS) ratio of 59%, initially only MS should be removed to produce a ratio closer to the eutectic point to reduce CP and maximize yield. Graphs relating yield (with 4:1 methyl stearate to methyl oleate carryover) to CP were produced to determine the economic viability of this approach. To evaluate the effect of blending TME with other methyl esters, SME and CME were blended with TME at blend ratios of 0 to 100%. Both the SME/TME and CME/TME blends exhibited decreased CPs with increasing levels of SME and CME. Although the CP of the SME/TME blends varied linearly with SME content, the CP of the CME/TME blends varied quadratically with CME content. To evaluate the potential of fuel additives to reduce the CP of TME, 11 different polymer additives were tested. Although all of these additives were specifically marketed to enhance the cold temperature properties of petroleum diesel or

Storage Rings

International Nuclear Information System (INIS)

Fischer, W.

2010-01-01

. Storage rings have instrumentation to monitor the electrical and mechanical systems, and the beam quality. Computers are used to control the operation. Large storage rings have millions of control points from all systems. The time dependent beam intensity I(t) can often be approximated by an exponential function I(t) = I(0) exp(-t/τ) (1) where the decay time τ and, correspondingly, the store time ranges from a few turns to 10 days (ISR). τ can be dominated by a variety of effects including lattice nonlinearities, beam-beam, space charge, intrabeam and Touschek scattering, interaction with the residual gas or target, or the lifetime of the stored particle. In this case, the beam lifetime measurement itself can be the purpose of a storage ring experiment. The main consideration in the design of a storage ring is the preservation of the beam quality over the store length. The beam size and momentum spread can be reduced through cooling, often leading to an increase in the store time. For long store times vacuum considerations are important since the interaction rate of the stored particles with the residual gas molecules is proportional to the pressure, and an ultra-high vacuum system may be needed. Distributed pumping with warm activated NEG surfaces or cold surfaces in machines with superconducting magnets are ways to provide large pumping speeds and achieve low pressures even under conditions with dynamic gas loads. The largest application of storage rings today are synchrotron light sources, of which about 50 exist world wide. In experiments where the beam collides with an internal target or another beam, a storage ring allows to re-use the accelerated beam many times if the interaction with the target is sufficiently small. In hadron collider and ion storage rings store times of many hours or even days are realized, corresponding to up to 1011 turns and thereby target passages. Ref. (3) is the first proposal for a collider storage ring. A number of storage rings

Simulated microbe removal around finger rings using different hand sanitation methods.

Science.gov (United States)

Alur, Archana A; Rane, Madhavi J; Scheetz, James P; Lorenz, Douglas J; Gettleman, Lawrence

2009-09-01

It is our opinion that the CDC and the WHO have underestimated cross-contamination under examination gloves in dental clinics while wearing jewelry, such as finger rings. These agencies only "recommend" removing jewelry, and only washing hands for 15 seconds with soap and warm water before donning gloves. This study examined several washing procedures and finger rings using simulated microbes. A gloved rubber hand manikin was made and fitted with a fresh disposable vinyl glove. Four fingers were fitted with rings or no ring, dusted with simulated microbes, and washed with a scrub brush for 5, 15, and 25 seconds under 20 degrees C and 40 degrees C water alone, or with liquid hand soap. Light levels (in lux) of fluorescent powder before and after washing were measured and delta scores calculated for changes in light levels, equivalent to effectiveness of hand washing procedures. A full-factorial, 3-factor analysis of variance (ANOVA) was used to test for differences among levels of the three study factors-time, temperature, and soap use. Tukey's post hoc honestly significant difference (HSD) test was applied to significant factors to examine pair-wise differences between factor levels. It was found that the longer the hands with rings were washed with a scrub brush under flowing water, the more simulated microbes were removed. By 25 seconds, all methods were essentially the same. Simulated microbes were more difficult to remove from the palm compared to the back of the hand. The liquid hand soap used in this study was more effective with warm water than cold. When given a choice of washing with cold water up to 15 seconds, it would be preferable not to use soap to remove simulated microbes. Qualitatively, the outer surface of finger rings were more effectively cleaned than the crevice below the ring, and the ring with a stone setting appeared to accumulate and retain simulated microbes more than other rings. The most effective treatment was washing with warm water

High-Power Ka-Band Window and Resonant Ring

International Nuclear Information System (INIS)

Jay L. Hirshfield

2006-01-01

A stand-alone 200 MW rf test station is needed for carrying out development of accelerator structures and components for a future high-gradient multi-TeV collider, such as CLIC. A high-power rf window is needed to isolate the test station from a structure element under test. This project aimed to develop such a window for use at a frequency in the range 30-35 GHz, and to also develop a high-power resonant ring for testing the window. During Phase I, successful conceptual designs were completed for the window and the resonant ring, and cold tests of each were carried out that confirmed the designs

Ring-Shaped Seismicity Structures in the Areas of Sarez and Nurek Water Reservoirs (Tajikistan): Lithosphere Adaptation to Additional Loading

Science.gov (United States)

Kopnichev, Yu. F.; Sokolova, I. N.

2017-12-01

Seismicity characteristics in the areas of Sarez Lake and the Nurek water reservoir are studied. Ring-shaped seismicity structures in two depth ranges (0-33 and 34-70 km) formed prior to the Pamir earthquake of December 7, 2015 ( M w = 7.2). Seismicity rings cross each other near the Usoi Dam, which formed after the strong earthquake in 1911 and led to the formation of Sarez Lake, and near the epicenter of the Pamir earthquake. In addition, three out of the four strongest events ( M ≥ 6.0) recorded in the Pamir region at depths of more than 70 km since 1950 have occurred near Sarez Lake. An aggregate of the data allows us to conclude that the Pamir earthquake, despite its very large energy, refers to events related to induced seismicity. Ring-shaped seismicity structures in two depth ranges also formed in the Nurek water reservoir area. It is supposed that the formation of ring-shaped structures is related to the self-organization processes of a geological system, which result in the ascent of deep-seated fluids. In this respect, the lithosphere is gradually adapting to the additional load related to the filling of the water reservoir. The difference between Nurek Dam (and many other hydroelectric power stations as well) and Usoi Dam is the permanent vibration in the former case due to water falling from a height of more than 200 m. Such an effect can lead to gradual stress dissipation, resulting in the occurrence of much weaker events when compared to the Pamir earthquake of December 7, 2015, in the areas of artificial water reservoirs.

Cold Leak Tests of LHC Beam Screens

CERN Document Server

Collomb-Patton, C; Jenninger, B; Kos, N

2009-01-01

In order to guide the high energy proton beams inside its two 27 km long vacuum rings, the Large Hadron Collider (LHC) at CERN, Geneva, makes use of superconducting technology to create the required magnetic fields. More than 4000 beam screens, cooled at 7 20 K, are inserted inside the 1.9 K beam vacuum tubes to intercept beam induced heat loads and to provide dynamic vacuum stability. As extremely high helium leak tightness is required, all beam screens have been leak tested under cold conditions in a dedicated test stand prior to their installation. After describing the beam screen design and its functions, this report focuses on the cold leak test sequence and discusses the results.

Damping Ring R&D at CESR-TA

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

Redox shuttles having an aromatic ring fused to a 1,1,4,4-tetrasubstituted cyclohexane ring

Science.gov (United States)

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.

Recovery in cold-worked alloy under pressure: example of AISI 316 stainless steel

Energy Technology Data Exchange (ETDEWEB)

Yousuf, M; Sahu, P C; Raghunathan, V S; Govinda Rajan, K

1986-06-01

In this paper we report the behaviour of defects under high pressure in severely cold-deformed 316 stainless steel. In situ electrical resistivity measurements indicate a minimum in the reduced resistivity ratio at 2 GPa associated with a characteristic relaxation time of 500 + - 5 sec. Microhardness data on pressure-treated and recovered samples are consistent with the electrical resistivity behaviour. X-ray powder diffraction rings indicate sharpening beyond 2 GPa. The decrease in the full width at half maximum (FWHM) of the strongest ring is about 2% at pressures beyond 2 GPa. Transmission electron microscopy reveals that samples pressure treated beyond 2 GPa have a polygonized dislocation structure. This is in sharp contrast to the tangled dislocation structure observed in the cold-worked samples. The experimental results suggest a recovery stage in cold-worked stainless steel at 2 GPa. We propose that the recovery process is activated through an enhanced vacancy concentration caused by deformation, a pressure-induced vacancy-dislocation interaction and consequently a pressure-assisted dislocation mobility leading to polygonization.

Weyl Exceptional Rings in a Three-Dimensional Dissipative Cold Atomic Gas (Author’s Manuscript)

Science.gov (United States)

2017-01-27

in a dissipative system with particle gain and loss, we discover a new type of topological ring, dubbed Weyl exceptional ring consisting of...valued. On the other hand , the Chern number is zero when the surface S does not enclose any part of the ring even when it is located inside it...k)〉 and Ãθ(k) = i〈ũθ(k)|∂kuθ(k)〉, where 〈ũθ(k)| is the normalized left eigenstate of H [i.e., 〈ũθ(k)|H(k) = 〈ũθ(k)|Eθ(k) and 〈ũθ(k)|uθ(k)〉 = 1

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

Pure subrings of the rings Zχ

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.

High Temperature Chemistry of Chlorinated Acenaphthylene. 3C Bay Acetylene Additions and Annealing by Five-Membered Ring Shifts.

Science.gov (United States)

McIntosh, Grant J; Russell, Douglas K

2015-12-24

Experimental and theoretical results concerning the growth and isomerization of chlorinated acenaphthylene, C12H8, during the pyrolysis of chlorohydrocarbons are presented here. A fullerene subunit, C12H8, is a useful system to investigate regarding C60 formation. However, direct experimental observation of isomerization and annealing processes in particular are difficult to confirm due to the high symmetry of the parent molecule. Chlorination lowers the symmetry, essentially labeling carbon atoms, allowing growth and isomerization to be followed directly. Pyrolysis of dichloro- and trichloroethylene, and their copyrolyses with trichlorobenzenes, provides an efficient and general source of chlorinated acenaphthylenes in a range of degrees of chlorination and over a number of unique congeners. Analysis of congener yields as a function of reagents employed, guided by DFT/B3LYP/6-311G(d,p) level calculations, strongly suggests that C2 addition across three-carbon bays in naphthalene is a major driver of growth. Additionally, extremely facile five-membered ring shifts are operative, with chlorine promoting isomerization. Theoretical study of C16H10- and C18H10-based congeners indicate that this is a general phenomenon, and with chlorine also favoring internal cyclopentafused rings in addition to increased isomerization rates, this suggests halogen moieties may be an important feature for efficient fullerene growth.

Cold fusion research

International Nuclear Information System (INIS)

1989-11-01

I am pleased to forward to you the Final Report of the Cold Fusion Panel. This report reviews the current status of cold fusion and includes major chapters on Calorimetry and Excess Heat, Fusion Products and Materials Characterization. In addition, the report makes a number of conclusions and recommendations, as requested by the Secretary of Energy

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.

Heating of field-reversed plasma rings estimated with two scaling models

Energy Technology Data Exchange (ETDEWEB)

Shearer, J.W.

1978-05-18

Scaling calculations are presented of the one temperature heating of a field-reversed plasma ring. Two sharp-boundary models of the ring are considered: the long thin approximation and a pinch model. Isobaric, adiabatic, and isovolumetric cases are considered, corresponding to various ways of heating the plasma in a real experiment by using neutral beams, or by raising the magnetic field. It is found that the shape of the plasma changes markedly with heating. The least sensitive shape change (as a function of temperature) is found for the isovolumetric heating case, which can be achieved by combining neutral beam heating with compression. The complications introduced by this heating problem suggest that it is desirable, if possible, to create a field reversed ring which is already quite hot, rather than cold.

Planetary Rings

Science.gov (United States)

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

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

Cold atmospheric plasma jet in an axial DC electric field

Energy Technology Data Exchange (ETDEWEB)

Lin, Li, E-mail: lilin@gwu.edu, E-mail: keidar@gwu.edu; Keidar, Michael, E-mail: lilin@gwu.edu, E-mail: keidar@gwu.edu [Department of Mechanical and Aerospace Engineering, School of Engineering and Applied Science, The George Washington University, Washington, DC 20052 (United States)

2016-08-15

Cold atmospheric plasma (CAP) jet is currently intensively investigated as a tool for new and potentially transformative cancer treatment modality. However, there are still many unknowns about the jet behavior that requires attention. In this paper, a helium CAP jet is tested in an electrostatic field generated by a copper ring. Using Rayleigh microwave scattering method, some delays of the electron density peaks for different ring potentials are observed. Meanwhile, a similar phenomenon associated with the bullet velocity is found. Chemical species distribution along the jet is analyzed based on the jet optical emission spectra. The spectra indicate that a lower ring potential, i.e., lower DC background electric field, can increase the amount of excited N{sub 2}, N{sub 2}{sup +}, He, and O in the region before the ring, but can decrease the amount of excited NO and HO almost along the entire jet. Combining all the results above, we discovered that an extra DC potential mainly affects the temporal plasma jet properties. Also, it is possible to manipulate the chemical compositions of the jet using a ring with certain electric potentials.

Carbon-Ring Microelectrode Arrays for Electrochemical Imaging of Single Cell Exocytosis: Fabrication and Characterization

Science.gov (United States)

Lin, Yuqing; Trouillon, Raphaël; Svensson, Maria I.; Keighron, Jacqueline D.; Cans, Ann-Sofie; Ewing, Andrew G.

2012-01-01

Fabrication of carbon microelectrode arrays, with up to 15 electrodes in total tips as small as 10 to 50 μm, is presented. The support structures of microelectrodes were obtained by pulling multiple quartz capillaries together to form hollow capillary arrays before carbon deposition. Carbon ring microelectrodes were deposited by pyrolysis of acetylene in the lumen of these quartz capillary arrays. Each carbon deposited array tip was filled with epoxy, followed by beveling of the tip of the array to form a deposited carbon-ring microelectrode array (CRMA). Both the number of the microelectrodes in the array and the tip size are independently tunable. These CRMAs have been characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, and electrogenerated chemiluminescence. Additionally, the electrochemical properties were investigated with steady-state voltammetry. In order to demonstrate the utility of these fabricated microelectrodes in neurochemistry, CRMAs containing eight microring electrodes were used for electrochemical monitoring of exocytotic events from single PC12 cells. Subcellular temporal heterogeneities in exocytosis (ie. cold spots vs. hot spots) were successfully detected with the CRMAs. PMID:22339586

Mechanical improvement of metal reinforcement rings for a finite ring-shaped superconducting bulk

Science.gov (United States)

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.

COLD MOLECULAR GAS IN THE INNER TWO KILOPARSECS OF NGC 4151

International Nuclear Information System (INIS)

Dumas, G.; Schinnerer, E.; Mundell, C. G.

2010-01-01

We present the first spatially resolved spectroscopic imaging observations of the 12 CO (1-0) line emission in the central 2.5 kpc of the Seyfert 1 galaxy NGC 4151, obtained with the IRAM Plateau de Bure Interferometer (PdBI). Most of the cold molecular gas is distributed along two curved gas lanes about 1 kpc north and south of the active nucleus, coincident with the circumnuclear dust ring noted by previous authors. These CO arcs lie within the Inner Lindblad Resonance of the large scale oval bar and have kinematics consistent with those derived from neutral hydrogen observations of the disk and the bar. Two additional gas clumps are detected that show non-circular motion-one associated with the southern gas lane and the other lying ∼600 pc north of the nucleus. Closer to the nucleus, no cold molecular gas is detected in the central 300 pc where abundant near-IR H 2 line emission arises. This suggests that the H 2 line emission is not a good indicator of a cold gas reservoir in NGC 4151 and that the H 2 is likely photo-excited by the active galactic nucleus (AGN). The upper limit of the CO mass in the central 300 pc is sufficient to support the AGN activity at its current level for 10 7 yr. The total cold molecular mass detected by PdBI is 4.3 x 10 7 M sun . Finally, 3 mm continuum emission arising from the location of the AGN is detected with a flux of S 3 m m ∼ 14 mJy and appears to be unresolved at an angular resolution of 2.''8 (∼180 pc).

On the possibility of generation of cold and additional electric energy at thermal power stations

Science.gov (United States)

Klimenko, A. V.; Agababov, V. S.; Borisova, P. N.

2017-06-01

A layout of a cogeneration plant for centralized supply of the users with electricity and cold (ECCG plant) is presented. The basic components of the plant are an expander-generator unit (EGU) and a vapor-compression thermotransformer (VCTT). At the natural-gas-pressure-reducing stations, viz., gas-distribution stations and gas-control units, the plant is connected in parallel to a throttler and replaces the latter completely or partially. The plant operates using only the energy of the natural gas flow without burning the gas; therefore, it can be classified as a fuelless installation. The authors compare the thermodynamic efficiencies of a centralized cold supply system based on the proposed plant integrated into the thermal power station scheme and a decentralized cold supply system in which the cold is generated by electrically driven vapor-compression thermotransformers installed on the user's premises. To perform comparative analysis, the exergy efficiency was taken as the criterion since in one of the systems under investigation the electricity and the cold are generated, which are energies of different kinds. It is shown that the thermodynamic efficiency of the power supply using the proposed plant proves to be higher within the entire range of the parameters under consideration. The article presents the results of investigating the impact of the gas heating temperature upstream from the expander on the electric power of the plant, its total cooling capacity, and the cooling capacities of the heat exchangers installed downstream from the EGU and the evaporator of the VCTT. The results of calculations are discussed that show that the cold generated at the gas-control unit of a powerful thermal power station can be used for the centralized supply of the cold to the ventilation and conditioning systems of both the buildings of the power station and the neighboring dwelling houses, schools, and public facilities during the summer season.

Novel Fiber-Optic Ring Acoustic Emission Sensor.

Science.gov (United States)

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.

S.C. correction coils and magnets for the HERA proton ring

International Nuclear Information System (INIS)

Daum, C.; Geerinck, J.; Schmueser, P.

1986-05-01

The quadrupole and sextupole correction coils of the HERA proton ring are mounted on the cold beam pipe inside the main dipole magnets. Superferric dipole magnets for orbit correction are located adjacent to the main quadrupole magnets in a common cryostat which also contains the beam monitor. The design, manufacture and performance of both types of correction elements are described. (orig.)

Multiplication modules over non-commutative rings

International Nuclear Information System (INIS)

Tuganbaev, A A

2003-01-01

It is proved that each submodule of a multiplication module over a regular ring is a multiplicative module. If A is a ring with commutative multiplication of right ideals, then each projective right ideal is a multiplicative module, and a finitely generated A-module M is a multiplicative module if and only if all its localizations with respect to maximal right ideals of A are cyclic modules over the corresponding localizations of A. In addition, several known results on multiplication modules over commutative rings are extended to modules over not necessarily commutative rings

Calcium addition at the Hubbard Brook Experimental Forest increases the capacity for stress tolerance and carbon capture in red spruce (Picea rubens) trees during the cold season

Science.gov (United States)

Paul G. Schaberg; Rakesh Minocha; Stephanie Long; Joshua M. Halman; Gary J. Hawley; Christopher. Eagar

2011-01-01

Red spruce (Picea rubens Sarg.) trees are uniquely vulnerable to foliar freezing injury during the cold season (fall and winter), but are also capable of photosynthetic activity if temperatures moderate. To evaluate the influence of calcium (Ca) addition on the physiology of red spruce during the cold season, we measured concentrations of foliar...

Wave-Kinetic Simulations of the Nonlinear Generation of Electromagnetic VLF Waves through Velocity Ring Instabilities

Science.gov (United States)

Ganguli, G.; Crabtree, C. E.; Rudakov, L.; Mithaiwala, M.

2014-12-01

Velocity ring instabilities are a common naturally occuring magnetospheric phenomenon that can also be generated by man made ionospheric experiments. These instabilities are known to generate lower-hybrid waves, which generally cannot propagte out of the source region. However, nonlinear wave physics can convert these linearly driven electrostatic lower-hybrid waves into electromagnetic waves that can escape the source region. These nonlinearly generated waves can be an important source of VLF turbulence that controls the trapped electron lifetime in the radiation belts. We develop numerical solutions to the wave-kinetic equation in a periodic box including the effects of nonlinear (NL) scattering (nonlinear Landau damping) of Lower-hybrid waves giving the evolution of the wave-spectra in wavenumber space. Simultaneously we solve the particle diffusion equation of both the background plasma particles and the ring ions, due to both linear and nonlinear Landau resonances. At initial times for cold ring ions, an electrostatic beam mode is excited, while the kinetic mode is stable. As the instability progresses the ring ions heat, the beam mode is stabilized, and the kinetic mode destabilizes. When the amplitude of the waves becomes sufficient the lower-hybrid waves are scattered (by either nearly unmagnetized ions or magnetized electrons) into electromagnetic magnetosonic waves [Ganguli et al 2010]. The effect of NL scattering is to limit the amplitude of the waves, slowing down the quasilinear relaxation time and ultimately allowing more energy from the ring to be liberated into waves [Mithaiwala et al. 2011]. The effects of convection out of the instability region are modeled, additionally limiting the amplitude of the waves, allowing further energy to be liberated from the ring [Scales et al., 2012]. Results are compared to recent 3D PIC simulations [Winske and Duaghton 2012].

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.

Initial heating in cold cars

NARCIS (Netherlands)

Daanen, H.A.M.; Teunissen, L.P.J.; Hoogh, I.M. de

2012-01-01

During the initial minutes after entering a cold car, people feel uncomfortably cold. Six different warming systems were investigated in a small car in order to find out how to improve the feeling of comfort using 16 volunteers. The methods were: no additional warming next to a standard heating

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.

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.

Order in cold ionic systems: Dynamic effects

International Nuclear Information System (INIS)

Schiffer, J.P.

1988-01-01

The present state and recent developments in Molecular Dynamics calculations modeling cooled heavy-ion beams are summarized. First, a frame of reference is established, summarizing what has happened in the past; then the properties of model systems of cold ions studied in Molecular Dynamics calculations are reviewed, with static boundary conditions with which an ordered state is revealed; finally, more recent results on such modelling, adding the complications in the (time-dependent) boundary conditions that begin to approach real storage rings (ion traps) are reported. 14 refs., 19 figs., 2 tabs

Polarized gas targets for storage rings

International Nuclear Information System (INIS)

Holt, R.J.

1990-01-01

It is widely recognized that polarized gas targets in electron storage rings represent a new opportunity for precision nuclear physics studies. New developments in polarized target technology specific to internal applications will be discussed. In particular, polarized gas targets have been used in the VEPP-3 electron ring in Novosibirsk. A simple storage cell was used to increase the total target thickness by a factor of 15 over the simple gas jet target from an atomic beam source. Results from the initial phase of this project will be reported. In addition, the plans for increasing the luminosity by an additional order or magnitude will be presented. The application of this work to polarized hydrogen and deuterium targets for the HERA ring will be noted. The influence of beam-induced depolarization, a phenomena encountered in short-pulse electron storage rings, will be discussed. Finally, the performance tests of laser-driven sources will be presented. 8 refs., 12 figs., 1 tab

Iterative Addition of Kinetic Effects to Cold Plasma RF Wave Solvers

Science.gov (United States)

Green, David; Berry, Lee; RF-SciDAC Collaboration

2017-10-01

The hot nature of fusion plasmas requires a wave vector dependent conductivity tensor for accurate calculation of wave heating and current drive. Traditional methods for calculating the linear, kinetic full-wave plasma response rely on a spectral method such that the wave vector dependent conductivity fits naturally within the numerical method. These methods have seen much success for application to the well-confined core plasma of tokamaks. However, quantitative prediction of high power RF antenna designs for fusion applications has meant a requirement of resolving the geometric details of the antenna and other plasma facing surfaces for which the Fourier spectral method is ill-suited. An approach to enabling the addition of kinetic effects to the more versatile finite-difference and finite-element cold-plasma full-wave solvers was presented by where an operator-split iterative method was outlined. Here we expand on this approach, examine convergence and present a simplified kinetic current estimator for rapidly updating the right-hand side of the wave equation with kinetic corrections. This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725.

Ring cavity for a Raman capillary waveguide amplifier

Science.gov (United States)

Kurnit, N.A.

1981-01-27

A regenerative ring amplifier and regenerative ring oscillator are described which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplified Stokes signal is synchronous with the mode-locked spikes of the incoming CO/sub 2/ laser pump signal.

Ring cavity for a Raman capillary waveguide amplifir

Science.gov (United States)

Kurnit, N.A.

1981-01-27

A regenerative ring amplifier and regenerative ring oscillator are described which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplified Stokes signal is synchronous with the mode-locked spikes of the incoming CO/sub 2/ laser pump signal.

A NEWLY FORMING COLD FLOW PROTOGALACTIC DISK, A SIGNATURE OF COLD ACCRETION FROM THE COSMIC WEB

International Nuclear Information System (INIS)

Martin, D. Christopher; Matuszewski, Mateusz; Morrissey, Patrick; Neill, James D.; Moore, Anna; Steidel, Charles C.; Trainor, Ryan

2016-01-01

How galaxies form from, and are fueled by, gas from the intergalactic medium (IGM) remains one of the major unsolved problems in galaxy formation. While the classical Cold Dark Matter paradigm posits galaxies forming from cooling virialized gas, recent theory and numerical simulations have highlighted the importance of cold accretion flows—relatively cool ( T ∼ few × 104 K) unshocked gas streaming along filaments into dark matter halos, including hot, massive, high-redshift halos. These flows are thought to deposit gas and angular momentum into the circumgalactic medium resulting in disk- or ring-like structures, eventually coalescing into galaxies forming at filamentary intersections. We earlier reported a bright, Ly α emitting filament near the QSO HS1549+19 at redshift z = 2.843 discovered with the Palomar Cosmic Web Imager. We now report that the bright part of this filament is an enormous ( R > 100 kpc) rotating structure of hydrogen gas with a disk-like velocity profile consistent with a 4 × 10"1"2 M _⊙ halo. The orbital time of the outer part of the what we term a “protodisk” is comparable to the virialization time and the age of the universe at this redshift. We propose that this protodisk can only have recently formed from cold gas flowing directly from the cosmic web.

A NEWLY FORMING COLD FLOW PROTOGALACTIC DISK, A SIGNATURE OF COLD ACCRETION FROM THE COSMIC WEB

Energy Technology Data Exchange (ETDEWEB)

Martin, D. Christopher; Matuszewski, Mateusz; Morrissey, Patrick; Neill, James D. [Cahill Center for Astrophysics, California Institute of Technology, 1216 East California Boulevard, Mail Code 278-17, Pasadena, California 91125 (United States); Moore, Anna [Caltech Optical Observatories, Cahill Center for Astrophysics, California Institute of Technology, 1216 East California Boulevard, Mail Code 11-17, Pasadena, California 91125 (United States); Steidel, Charles C. [Cahill Center for Astrophysics, California Institute of Technology, 1216 East California Boulevard, Mail Code 249-17, Pasadena, California 91125 (United States); Trainor, Ryan, E-mail: cmartin@srl.caltech.edu [Department of Astronomy, University of California, Berkeley, 501 15 Campbell Hall, Berkeley, CA 94720 (United States)

2016-06-10

How galaxies form from, and are fueled by, gas from the intergalactic medium (IGM) remains one of the major unsolved problems in galaxy formation. While the classical Cold Dark Matter paradigm posits galaxies forming from cooling virialized gas, recent theory and numerical simulations have highlighted the importance of cold accretion flows—relatively cool ( T ∼ few × 104 K) unshocked gas streaming along filaments into dark matter halos, including hot, massive, high-redshift halos. These flows are thought to deposit gas and angular momentum into the circumgalactic medium resulting in disk- or ring-like structures, eventually coalescing into galaxies forming at filamentary intersections. We earlier reported a bright, Ly α emitting filament near the QSO HS1549+19 at redshift z = 2.843 discovered with the Palomar Cosmic Web Imager. We now report that the bright part of this filament is an enormous ( R > 100 kpc) rotating structure of hydrogen gas with a disk-like velocity profile consistent with a 4 × 10{sup 12} M {sub ⊙} halo. The orbital time of the outer part of the what we term a “protodisk” is comparable to the virialization time and the age of the universe at this redshift. We propose that this protodisk can only have recently formed from cold gas flowing directly from the cosmic web.

Selective Tree-ring Models: A Novel Method for Reconstructing Streamflow Using Tree Rings

Science.gov (United States)

Foard, M. B.; Nelson, A. S.; Harley, G. L.

2017-12-01

Surface water is among the most instrumental and vulnerable resources in the Northwest United States (NW). Recent observations show that overall water quantity is declining in streams across the region, while extreme flooding events occur more frequently. Historical streamflow models inform probabilities of extreme flow events (flood or drought) by describing frequency and duration of past events. There are numerous examples of tree-rings being utilized to reconstruct streamflow in the NW. These models confirm that tree-rings are highly accurate at predicting streamflow, however there are many nuances that limit their applicability through time and space. For example, most models predict streamflow from hydrologically altered rivers (e.g. dammed, channelized) which may hinder our ability to predict natural prehistoric flow. They also have a tendency to over/under-predict extreme flow events. Moreover, they often neglect to capture the changing relationships between tree-growth and streamflow over time and space. To address these limitations, we utilized national tree-ring and streamflow archives to investigate the relationships between the growth of multiple coniferous species and free-flowing streams across the NW using novel species-and site-specific streamflow models - a term we coined"selective tree-ring models." Correlation function analysis and regression modeling were used to evaluate the strengths and directions of the flow-growth relationships. Species with significant relationships in the same direction were identified as strong candidates for selective models. Temporal and spatial patterns of these relationships were examined using running correlations and inverse distance weighting interpolation, respectively. Our early results indicate that (1) species adapted to extreme climates (e.g. hot-dry, cold-wet) exhibit the most consistent relationships across space, (2) these relationships weaken in locations with mild climatic variability, and (3) some

Wavepacket revivals in monolayer and bilayer graphene rings.

Science.gov (United States)

García, Trinidad; Rodríguez-Bolívar, Salvador; Cordero, Nicolás A; Romera, Elvira

2013-06-12

We have studied the existence of quantum revivals in graphene quantum rings within a simplified model. The time evolution of a Gaussian-populated wavepacket shows revivals in monolayer and bilayer graphene rings. We have also studied this behavior for quantum rings in a perpendicular magnetic field. We have found that revival time is an observable that shows different values for monolayer and bilayer graphene quantum rings. In addition, the revival time shows valley degeneracy breaking.

Mechanisms of fragmentation and microstructure of debris generated during explosive testing of Al-W granular composite rings

International Nuclear Information System (INIS)

Chiu, Po-Hsun; Nesterenko, V F; Olney, K L; Braithwaite, C; Jardine, A; Collins, A; Benson, D J

2014-01-01

Highly heterogeneous materials comprised of elements with drastically different densities and shock impedances (e.g., Al and W) may provide additional mesoscale fragmentation mechanisms reducing the characteristic fragment size in comparison with solid materials with similar density (e.g., Stainless Steel 304). Explosively driven expanding ring experiments were conducted with Al-W granular composite rings, processed using hot and cold isostatic pressing, with different morphologies (W polyhedral particles or W rods with high aspect ratio and bonded/unbonded Al spherical particles with different sizes). In comparison to homogeneous samples with a similar density, these granular/porous composites generated fragments with a significantly smaller characteristic size. Scanning Electron Microscopy revealed that fragments had a propensity to be composed of clustered Al and W particles. Finite element simulations were conducted to gain an insight into the mesoscale fragmentation mechanisms and the clustering behavior observed in the experiments. Understanding the mesoscale mechanisms of explosively driven pulverization is important for tailoring the size of the fragments through the alteration of mesostructural properties.

Wavepacket revivals in monolayer and bilayer graphene rings

International Nuclear Information System (INIS)

García, Trinidad; Rodríguez-Bolívar, Salvador; Cordero, Nicolás A; Romera, Elvira

2013-01-01

We have studied the existence of quantum revivals in graphene quantum rings within a simplified model. The time evolution of a Gaussian-populated wavepacket shows revivals in monolayer and bilayer graphene rings. We have also studied this behavior for quantum rings in a perpendicular magnetic field. We have found that revival time is an observable that shows different values for monolayer and bilayer graphene quantum rings. In addition, the revival time shows valley degeneracy breaking. (paper)

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

Additional diagnostic value of 99Tcm-MIBI imaging over 'cold' nodules in 99Tcm thyroid imaging proved by ROC analysis

International Nuclear Information System (INIS)

Mei Ping; Qin Yongde; Wang Saigang; Ruxianguli; Baya; Lv Jie; Xie Bing; Sun Xiaoyan

2007-01-01

Objective: More studies have found that 99 Tc m -MIBI thyroid imaging may provide more differential diagnostic value than traditional 99 Tc m O 4 - thyroid imaging. This study attempted to analyze the receiver operating characteristic (ROC) curves to verify the additional diagnostic value of 99 Tc m -MIBI over 99 Tc m O 4 - thyroid imaging in the differentiation of the 'cold' nodules. Methods: Sixty-eight patients initially diagnosed with 'cold' nodules in 99 Tc m O 4 - thyroid scintigraphy were selected for further 99 Tc m -MIBI thyroid imaging at early (15 min after 99 Tc m -MIBI intravenous injection, ER) and delayed phase (2 h after injection, DR). Semi-quantitative analysis was performed using tumor/normal tissue (T/N) ratio both at ER and DR, with 0.8 defined as the threshold for differential diagnoses. In ROC curves analyses, the ratios from tumor/submaxillary gland (T/S) and tumor/heart (T/H) were derived to obtain the most proper differential diagnostic thresholds. Results: Of all patients with the 'cold' nodules, only eight cases were finally diagnosed on pathology with thyroid malignancy, while other 60 were benign. For differential diagnoses, the sensitivity, specificity and accuracy of semi-quantitative 99 Tc m -MIBI thyroid imaging were 100.0%, 76.7% and 79.4% respectively. However, with thresholds of T/N=0.995, T/S=0.995, T/H=1.005 derived from ROC curves for DR 99 Tc m -MIBI imaging, the differential diagnostic sensitivities were 100.0%, 87.5%, 75.0% and the specificities were 90.0%, 85.0%, 83.3% respectively. The areas under the ROC curves were 0.949, 0.876 and 0. 867 respectively for DR, all significantly larger than those of ER. Statistical difference was also evident between threshold values of 0.8 and 0.995 (χ 2 =6.125, P 99 Tc m -MIBI thyroid imaging provide additional diagnostic value over 99 Tc m O 4 - thyroid imaging for the differentiation of the 'cold' nodules. For 99 Tc m -MIBI thyroid imaging, DR is more valuable than ER in the ROC

Influence of topology in a quantum ring

International Nuclear Information System (INIS)

Netto, A.L. Silva; Chesman, C.; Furtado, C.

2008-01-01

In this Letter we study the quantum rings in the presence of a topological defect. We use geometric theory of defects to describe one and two-dimensional quantum rings in the presence of a single screw dislocation. In addition we consider some potential in a two dimensional ring and calculate their energy spectrum. It is shown that the energy spectrum depend on the parabolic way on the burgers vectors of the screw dislocation. We also show that the presence of a topological defect introduces a new contribution for the Aharonov-Bohm effect in the quantum ring

Ring Theory

CERN Document Server

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.

Synthesis of the EF-ring of ciguatoxin 3C based on the [2,3]-Wittig rearrangement and ring-closing olefin metathesis.

Science.gov (United States)

Goto, Akiyoshi; Fujiwara, Kenshu; Kawai, Ayako; Kawai, Hidetoshi; Suzuki, Takanori

2007-12-20

The EF-ring segment of ciguatoxin 3C, a causative toxin of ciguatera fish poisoning, was synthesized in three major steps: 1,4-addition for the C20O-C27 bond connection, chirality transferring anti selective [2,3]-Wittig rearrangement for the construction of the anti-2-hydroxyalkyl ether part, and ring-closing olefin metathesis for the F-ring formation.

Vertically coupled double quantum rings at zero magnetic field

OpenAIRE

Malet, Francesc; Barranco, Manuel; Lipparini, Enrico; Pi, Ricardo Mayol Martí; Climente, Juan Ignacio; Planelles, Josep

2006-01-01

Within local-spin-density functional theory, we have investigated the `dissociation' of few-electron circular vertical semiconductor double quantum ring artificial molecules at zero magnetic field as a function of inter-ring distance. In a first step, the molecules are constituted by two identical quantum rings. When the rings are quantum mechanically strongly coupled, the electronic states are substantially delocalized, and the addition energy spectra of the artificial molecule resemble thos...

Comparison of structure, function and regulation of plant cold shock domain proteins to bacterial and animal cold shock domain proteins.

Science.gov (United States)

Chaikam, Vijay; Karlson, Dale T

2010-01-01

The cold shock domain (CSD) is among the most ancient and well conserved nucleic acid binding domains from bacteria to higher animals and plants. The CSD facilitates binding to RNA, ssDNA and dsDNA and most functions attributed to cold shock domain proteins are mediated by this nucleic acid binding activity. In prokaryotes, cold shock domain proteins only contain a single CSD and are termed cold shock proteins (Csps). In animal model systems, various auxiliary domains are present in addition to the CSD and are commonly named Y-box proteins. Similar to animal CSPs, plant CSPs contain auxiliary C-terminal domains in addition to their N-terminal CSD. Cold shock domain proteins have been shown to play important roles in development and stress adaptation in wide variety of organisms. In this review, the structure, function and regulation of plant CSPs are compared and contrasted to the characteristics of bacterial and animal CSPs. [BMB reports 2010; 43(1): 1-8].

Detection of cold pain, cold allodynia and cold hyperalgesia in freely behaving rats

Directory of Open Access Journals (Sweden)

Woolf Clifford J

2005-12-01

Full Text Available Abstract Background Pain is elicited by cold, and a major feature of many neuropathic pain states is that normally innocuous cool stimuli begin to produce pain (cold allodynia. To expand our understanding of cold induced pain states we have studied cold pain behaviors over a range of temperatures in several animal models of chronic pain. Results We demonstrate that a Peltier-cooled cold plate with ± 1°C sensitivity enables quantitative measurement of a detection withdrawal response to cold stimuli in unrestrained rats. In naïve rats the threshold for eliciting cold pain behavior is 5°C. The withdrawal threshold for cold allodynia is 15°C in both the spared nerve injury and spinal nerve ligation models of neuropathic pain. Cold hyperalgesia is present in the spared nerve injury model animals, manifesting as a reduced latency of withdrawal response threshold at temperatures that elicit cold pain in naïve rats. We also show that following the peripheral inflammation produced by intraplantar injection of complete Freund's adjuvant, a hypersensitivity to cold occurs. Conclusion The peltier-cooled provides an effective means of assaying cold sensitivity in unrestrained rats. Behavioral testing of cold allodynia, hyperalgesia and pain will greatly facilitate the study of the neurobiological mechanisms involved in cold/cool sensations and enable measurement of the efficacy of pharmacological treatments to reduce these symptoms.

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.

Characteristics of hot electron ring in a simple magnetic mirror field

International Nuclear Information System (INIS)

Hosokawa, M.; Ikegami, H.

1980-12-01

Characteristics of hot electron ring are studied in a simple magnetic mirror machine (mirror ratio 2 : 1) with a diameter of 30 cm at the midplane and with the distance of 80 cm between the mirrors. Maximum microwave input power is 5 kW at 6.4 GHz with the corresponding power density of approximately 0.3 W/cm 3 . With a background cold plasma of 4 x 10 11 cm -3 , hot electron rings are most effectively generated in two cases when the magnetic field on the axis of the midplane is set near the fundamental or the second harmonic electron cyclotron resonance to the applied microwave frequency. Density profile of the hot electrons is observed to take a so-called ring shape with a radius controllable by the magnetic field intensity and with an axial length of approximately 10 cm. The radial cut view of the ring, however, indicates an M shape density profile, and the density of the hot electrons on the axis is about one half of the density at the ring. Approximately 30 msec is needed before generating the hot electron ring at the density of 10 10 cm -3 with an average kinetic energy of 100 keV. The ultimate energy distribution function is observed to have a stepwise cut in the high energy tail and no energetic components above 1 MeV are detected. The hot electron ring is susceptible to a few instabilities which can be artificially triggered. One of the instabilities is observed to associate with a loss of lower energetic electrons and microwave bursts. At the instability, the ring shape is observed to transform into a filled cylinder in a few microseconds and disappear. (author)

SSC collider quadrupole cold mass design and development

International Nuclear Information System (INIS)

Farrell, R.A.; Murray, F.S.; Jonas, P.A.; Mischler, W.R.; Blecher, L.

1992-01-01

Approximately 1,664 focussing and defocussing superconducting quadrupoles are required for the two SSC collider rings. Collider quadruple magnets (CQMS) must satisfy stringent performance, reliability, life and low cost criteria. Performance requirements include field uniformity, training, quench, tracking, thermal cycling and alignment. The CQM cold mass design presented incorporates lessons IGC and Alsthom Intermagnetics S.A. (AISA), our joint venture with GEC-Alsthom, learned in the design, development and manufacture of 500 MRI, 160 high-field custom and 126 HERA quadruple superconducting magnets. This baseline design reflects careful quantitative assessment of coil winding placement and collar material, evaluation of field uniformity and mechanical performance of the magnet coil ends using 3-D modeling and analysis, and considers tolerance and process variability. Selected CQM cold mass design highlights and a proposed prototype development program that allows incorporation of test feedback into the design to minimize risk are detailed in this paper. This information may be helpful to SSCL in the design and development of prototype CQM'S

Propellers in Saturn's rings

Science.gov (United States)

Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

2013-12-01

high and relatively low optical depth. From the radial separation of the propeller wings we estimate that the embedded body is about 1.5km in size. In addition to the population of "big" propellers we found evidence for a population of much smaller propellers which are more similar to known A ring propellers (size r=94,958km. The feature represents a gap with a width of 300m. This gap is statistically significant and consists of 6 consequent high counts. All other UVIS occultations show a flat and boring profile at this location. The r=94,958km feature is very similar in shape and size to a known detection of A ring propeller Bleriot from zeta Persei Rev42 occultation. This feature is also found as a dark spot moving at Kepler speed across several ISS images. Additionally we found 5 more small propeller candidates in ISS images of the inner B ring.

Series fabrication of the main quadrupole cold masses for the LHC begins

CERN Multimedia

2003-01-01

Three hundred and sixty main quadrupole (MQ) magnets will perform the principal beam focusing around the 27 km LHC ring. CERN and CEA-Saclay began collaborating on the development and prototyping of these magnets in 1989. This resulted in five highly successful quadrupole units - also known as short straight sections - one of which was integrated for testing in String 1, and two others of the final design in String 2. Once the tests had confirmed the validity of the design and realization, the fabrication of the 360 cold masses had to be transferred to industry.The German firm ACCEL Instruments was entrusted both with the construction of the quadrupole magnets themselves, and with their assembly into the cold masses together with various combinations of corrector magnets produced by other European manufacturers. Here we see the first of the cold masses containing the MQ magnet of the machine arcs together with two types of corrector magnet ready for shipping to CERN. Pictured with this first unit, delivered o...

Harnessing case isolation and ring vaccination to control Ebola.

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Chad Wells

2015-05-01

Full Text Available As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures including contact tracing, quarantine, and case isolation are being implemented. In addition, public health agencies are scaling up efforts to test and deploy candidate vaccines. Given the experimental nature and limited initial supplies of vaccines, a mass vaccination campaign might not be feasible. However, ring vaccination of likely case contacts could provide an effective alternative in distributing the vaccine. To evaluate ring vaccination as a strategy for eliminating Ebola, we developed a pair approximation model of Ebola transmission, parameterized by confirmed incidence data from June 2014 to January 2015 in Liberia and Sierra Leone. Our results suggest that if a combined intervention of case isolation and ring vaccination had been initiated in the early fall of 2014, up to an additional 126 cases in Liberia and 560 cases in Sierra Leone could have been averted beyond case isolation alone. The marginal benefit of ring vaccination is predicted to be greatest in settings where there are more contacts per individual, greater clustering among individuals, when contact tracing has low efficacy or vaccination confers post-exposure protection. In such settings, ring vaccination can avert up to an additional 8% of Ebola cases. Accordingly, ring vaccination is predicted to offer a moderately beneficial supplement to ongoing non-pharmaceutical Ebola control efforts.

Harnessing case isolation and ring vaccination to control Ebola.

Science.gov (United States)

Wells, Chad; Yamin, Dan; Ndeffo-Mbah, Martial L; Wenzel, Natasha; Gaffney, Stephen G; Townsend, Jeffrey P; Meyers, Lauren Ancel; Fallah, Mosoka; Nyenswah, Tolbert G; Altice, Frederick L; Atkins, Katherine E; Galvani, Alison P

2015-05-01

As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures including contact tracing, quarantine, and case isolation are being implemented. In addition, public health agencies are scaling up efforts to test and deploy candidate vaccines. Given the experimental nature and limited initial supplies of vaccines, a mass vaccination campaign might not be feasible. However, ring vaccination of likely case contacts could provide an effective alternative in distributing the vaccine. To evaluate ring vaccination as a strategy for eliminating Ebola, we developed a pair approximation model of Ebola transmission, parameterized by confirmed incidence data from June 2014 to January 2015 in Liberia and Sierra Leone. Our results suggest that if a combined intervention of case isolation and ring vaccination had been initiated in the early fall of 2014, up to an additional 126 cases in Liberia and 560 cases in Sierra Leone could have been averted beyond case isolation alone. The marginal benefit of ring vaccination is predicted to be greatest in settings where there are more contacts per individual, greater clustering among individuals, when contact tracing has low efficacy or vaccination confers post-exposure protection. In such settings, ring vaccination can avert up to an additional 8% of Ebola cases. Accordingly, ring vaccination is predicted to offer a moderately beneficial supplement to ongoing non-pharmaceutical Ebola control efforts.

The barrel EM is cold and full

CERN Document Server

Fournier, D

After insertion of the two EM wheels in the cryostat in 2003, the cold vessel was finally closed in December (Omega seals and welds). This was then followed by the installation of the solenoid in February, and the closing of the warm vessel in March (see eNews of December 2003). During these few months the LAr cryogenic system was thoroughly tested, and its control system commissioned, each of the ~1000 control points at a time. Finally, in April the cool-down could start. Rather unusual for liquid argon detectors, the cool-down was made in its first part (above 140K) by circulating cold nitrogen gas (instead of liquid nitrogen) in the heat exchangers. The reason was to limit as much as possible temperature gradients in the calorimeter body. With the accordion structure, each of the EM wheel behaves as a single piece, which could be damaged if the supporting rings at its outside would contract faster than the active part inside. Also with improperly controlled gradients, the two wheels - 4 meters in diamete...

Testing the additive versus the compensatory hypothesis of mortality from ring recovery data using a random effects model

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Schaub, M.

2004-06-01

Full Text Available The interaction of an additional source of mortality with the underlying “natural” one strongly affects population dynamics. We propose an alternative way to test between two forms of interaction, total additivity and compensation. In contrast to existing approaches, only ring-recovery data where the cause of death of each recovered individual is known are needed. Cause-specific mortality proportions are estimated based on a multistate capture-recapture model. The hypotheses are tested by inspecting the correlation between the cause-specific mortality proportions. A variance decomposition is performed to obtain a proper estimate of the true process correlation. The estimation of the cause-specific mortality proportions is the most critical part of the approach. It works well if at least one of the two mortality rates varies across time and the two recovery rates are constant across time. We illustrate this methodology by a case study of White Storks Ciconia ciconia where we tested whether mortality induced by power line collision is additive to other forms of mortality.

Saturn’s ring temperatures at equinox

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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.

Evaluation of pelvic ring injuries using SPECT/CT

Energy Technology Data Exchange (ETDEWEB)

Scheyerer, Max J. [University Hospital Zurich, Division of Trauma Surgery, Department of Surgery, Zurich (Switzerland); University Medical Center, Centre for Orthopaedic and Trauma Surgery, Cologne (Germany); Huellner, Martin; Pietsch, Carsten [University Hospital Zurich, Division of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); Werner, Clement M.L. [University Hospital Zurich, Division of Trauma Surgery, Department of Surgery, Zurich (Switzerland); Veit-Haibach, Patrick [University Hospital Zurich, Division of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); University Hospital Zurich, Diagnostic and Interventional Radiology, Department of Medical Radiology, Zurich (Switzerland)

2014-08-12

The incidence of pelvic fractures is relatively low compared with other fracture locations. The low incidence is in great contrast to the high morbidity and mortality. Particularly in the elderly, with apparently isolated fractures of the pubic rami, these observations are believed to be due to additional occult lesions of the posterior pelvic ring. In these cases diagnosis cannot be established by conventional imaging alone and SPECT/CT is considered as a diagnostic adjunct. The aim of this study was to assess concomitant bony or soft tissue lesions within the pelvic ring in a population of patients with fractures of the anterior elements. In all patients with no obvious lesions of the posterior pelvic ring on X-rays and CT or with suspicious but inconclusive findings on CT an additional SPECT/CT was carried out in a non-acute setting within 3 days of the trauma. In all cases additional lesions within the pelvic ring were found. Most lesions were vertical sacral fractures, followed by transverse fractures, one non-dislocated fracture of the acetabulum on the side of the pubic rami fracture, and one post-traumatic dilatation of the sacroiliac joint with increased tracer uptake. According to our results after SPECT/CT all patients with pubic rami fracture suffered additional lesions, none detectable previously by X-ray or CT, within the pelvic ring. In this context SPECT/CT has proved to be very helpful in the clinical routine to visualize occult fractures and instability within the sacroiliac joint. (orig.)

Frequent extreme cold exposure and brown fat and cold-induced thermogenesis: a study in a monozygotic twin.

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Maarten J Vosselman

Full Text Available INTRODUCTION: Mild cold acclimation is known to increase brown adipose tissue (BAT activity and cold-induced thermogenesis (CIT in humans. We here tested the effect of a lifestyle with frequent exposure to extreme cold on BAT and CIT in a Dutch man known as 'the Iceman', who has multiple world records in withstanding extreme cold challenges. Furthermore, his monozygotic twin brother who has a 'normal' sedentary lifestyle without extreme cold exposures was measured. METHODS: The Iceman (subject A and his brother (subject B were studied during mild cold (13°C and thermoneutral conditions (31°C. Measurements included BAT activity and respiratory muscle activity by [18F]FDG-PET/CT imaging and energy expenditure through indirect calorimetry. In addition, body temperatures, cardiovascular parameters, skin perfusion, and thermal sensation and comfort were measured. Finally, we determined polymorphisms for uncoupling protein-1 and β3-adrenergic receptor. RESULTS: Subjects had comparable BAT activity (A: 1144 SUVtotal and B: 1325 SUVtotal, within the range previously observed in young adult men. They were genotyped with the polymorphism for uncoupling protein-1 (G/G. CIT was relatively high (A: 40.1% and B: 41.9%, but unlike during our previous cold exposure tests in young adult men, here both subjects practiced a g-Tummo like breathing technique, which involves vigorous respiratory muscle activity. This was confirmed by high [18F]FDG-uptake in respiratory muscle. CONCLUSION: No significant differences were found between the two subjects, indicating that a lifestyle with frequent exposures to extreme cold does not seem to affect BAT activity and CIT. In both subjects, BAT was not higher compared to earlier observations, whereas CIT was very high, suggesting that g-Tummo like breathing during cold exposure may cause additional heat production by vigorous isometric respiratory muscle contraction. The results must be interpreted with caution given the

Analysis of cold resistance and identification of SSR markers linked to cold resistance genes in Brassica rapa L.

Science.gov (United States)

Huang, Zhen; Zhang, Xuexian; Jiang, Shouhua; Qin, Mengfan; Zhao, Na; Lang, Lina; Liu, Yaping; Tian, Zhengshu; Liu, Xia; Wang, Yang; Zhang, Binbin; Xu, Aixia

2017-06-01

Currently, cold temperatures are one of the main factors threatening rapeseed production worldwide; thus, it is imperative to identify cold-resistant germplasm and to cultivate cold-resistant rapeseed varieties. In this study, the cold resistance of four Brassica rapa varieties was analyzed. The cold resistance of Longyou6 and Longyou7 was better than that of Tianyou2 and Tianyou4. Thus, an F 2 population derived from Longyou6 and Tianyou4 was used to study the correlation of cold resistance and physiological indexes. Our results showed that the degree of frost damage was related to the relative conductivity and MDA content (r1 = 0.558 and r2 = 0.447, respectively). In order to identify the markers related to cold resistance, 504 pairs of SSR (simple sequence repeats) primers were used to screen the two parents and F 2 population. Four and five SSR markers had highly significant positive correlation to relative conductivity and MDA, respectively. In addition, three of these SSR markers had a highly significant positive correlation to both of these two indexes. These three SSR markers were subsequently confirmed to be used to distinguish between cold-resistant and non-cold-resistant varieties. The results of this study will lay a solid foundation for the mapping of cold-resistant genes and molecular markers assisted selection for the cold-resistance.

An Archetype Semi-Ring Fabry-Perot (SRFP) Resonator

Science.gov (United States)

Taghavi-Larigani, Shervin; VanZyl, Jakob

2009-01-01

We introduce and demonstrate the generation of a novel resonator, termed Semi-Ring Fabry-Perot (SRFP), that exhibits unique features, such as, its use of one plane mirror, allowing the SRFP to be easily fabricated as a symmetrical device. In addition to its unique features, it exhibits advantages of ring and Fabry-Perot resonators: 1) compared to a ring resonator that only allows a transmitted intensity, the Semi-Ring Fabry-Perot (SRFP) supports standing waves, allowing both a reflected and transmitted intensity; 2) the reflected light spectrum of the SRFP resonator is much narrower than similar Fabry-Perot, implying higher finesse.

ASSOCIATIVE RINGS SOLVED AS LIE RINGS

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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

Accretion in Saturn's F Ring

Science.gov (United States)

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

Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS

Science.gov (United States)

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.

Increased Adhesion of Listeria monocytogenes Strains to Abiotic Surfaces under Cold Stress

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Bo-Hyung Lee

2017-11-01

Full Text Available Food contamination by Listeria monocytogenes remains a major concern for some food processing chains, particularly for ready-to-eat foods, including processed foods. Bacterial adhesion on both biotic and abiotic surfaces is a source of contamination by pathogens that have become more tolerant or even persistent in food processing environments, including in the presence of adverse conditions such as cold and dehydration. The most distinct challenge that bacteria confront upon entry into food processing environments is the sudden downshift in temperature, and the resulting phenotypic effects are of interest. Crystal violet staining and the BioFilm Ring Test® were applied to assess the adhesion and biofilm formation of 22 listerial strains from different serogroups and origins under cold-stressed and cold-adapted conditions. The physicochemical properties of the bacterial surface were studied using the microbial adhesion to solvent technique. Scanning electron microscopy was performed to visualize cell morphology and biofilm structure. The results showed that adhesion to stainless-steel and polystyrene was increased by cold stress, whereas cold-adapted cells remained primarily in planktonic form. Bacterial cell surfaces exhibited electron-donating properties regardless of incubation temperature and became more hydrophilic as temperature decreased from 37 to 4°C. Moreover, the adhesion of cells grown at 4°C correlated with affinity for ethyl acetate, indicating the role of cell surface properties in adhesion.

Vortex Ring Interaction with a Heated Screen

Science.gov (United States)

Smith, Jason; Krueger, Paul S.

2008-11-01

Previous examinations of vortex rings impinging on porous screens has shown the reformation of the vortex ring with a lower velocity after passing through the screen, the creation of secondary vortices, and mixing. A heated screen could, in principle, alter the vortex-screen interaction by changing the local liquid viscosity and density. In the present investigation, a mechanical piston-cylinder vortex ring generator was used to create vortex rings in an aqueous sucrose solution. The rings impinged on a screen of horizontal wires that were heated using electrical current. The flow was visualized with food color and video imaging. Tests with and without heat were conducted at a piston stroke-to-jet diameter ratio of 4 and a jet Reynolds number (Re) of 1000. The vortex rings slowed after passing through the screen, but in tests with heat, they maintained a higher fraction of their before-screen velocity due to reduction in fluid viscosity near the wires. In addition, small ``fingers'' that developed on the front of the vortex rings as they passed through the screen exhibited positive buoyancy effects in the heated case.

A note on derivations in semiprime rings

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Joso Vukman

2005-01-01

Full Text Available We prove in this note the following result. Let n>1 be an integer and let R be an n!-torsion-free semiprime ring with identity element. Suppose that there exists an additive mapping D:R→R such that D(xn=∑j=1nxn−jD(xxj−1 is fulfilled for all x∈R. In this case, D is a derivation. This research is motivated by the work of Bridges and Bergen (1984. Throughout, R will represent an associative ring with center Z(R. Given an integer n>1, a ring R is said to be n-torsion-free if for x∈R, nx=0 implies that x=0. Recall that a ring R is prime if for a,b∈R, aRb=(0 implies that either a=0 or b=0, and is semiprime in case aRa=(0 implies that a=0. An additive mapping D:R→R is called a derivation if D(xy=D(xy+xD(y holds for all pairs x,y∈R and is called a Jordan derivation in case D(x2=D(xx+xD(x is fulfilled for all x∈R. Every derivation is a Jordan derivation. The converse is in general not true. A classical result of Herstein (1957 asserts that any Jordan derivation on a prime ring with characteristic different from two is a derivation. A brief proof of Herstein's result can be found in 1988 by Brešar and Vukman. Cusack (1975 generalized Herstein's result to 2-torsion-free semiprime rings (see also Brešar (1988 for an alternative proof. For some other results concerning derivations on prime and semiprime rings, we refer to Brešar (1989, Vukman (2005, Vukman and Kosi-Ulbl (2005.

How cold is cold dark matter?

International Nuclear Information System (INIS)

Armendariz-Picon, Cristian; Neelakanta, Jayanth T.

2014-01-01

If cold dark matter consists of particles, these must be non-interacting and non-relativistic by definition. In most cold dark matter models however, dark matter particles inherit a non-vanishing velocity dispersion from interactions in the early universe, a velocity that redshifts with cosmic expansion but certainly remains non-zero. In this article, we place model-independent constraints on the dark matter temperature to mass ratio, whose square root determines the dark matter velocity dispersion. We only assume that dark matter particles decoupled kinetically while non-relativistic, when galactic scales had not entered the horizon yet, and that their momentum distribution has been Maxwellian since that time. Under these assumptions, using cosmic microwave background and matter power spectrum observations, we place upper limits on the temperature to mass ratio of cold dark matter today (away from collapsed structures). These limits imply that the present cold dark matter velocity dispersion has to be smaller than 54 m/s. Cold dark matter has to be quite cold, indeed

Cold stress induces lower urinary tract symptoms.

Science.gov (United States)

Imamura, Tetsuya; Ishizuka, Osamu; Nishizawa, Osamu

2013-07-01

Cold stress as a result of whole-body cooling at low environmental temperatures exacerbates lower urinary tract symptoms, such as urinary urgency, nocturia and residual urine. We established a model system using healthy conscious rats to explore the mechanisms of cold stress-induced detrusor overactivity. In this review, we summarize the basic findings shown by this model. Rats that were quickly transferred from room temperature (27 ± 2°C) to low temperature (4 ± 2°C) showed detrusor overactivity including increased basal pressure and decreased voiding interval, micturition volume, and bladder capacity. The cold stress-induced detrusor overactivity is mediated through a resiniferatoxin-sensitve C-fiber sensory nerve pathway involving α1-adrenergic receptors. Transient receptor potential melastatin 8 channels, which are sensitive to thermal changes below 25-28°C, also play an important role in mediating the cold stress responses. Additionally, the sympathetic nervous system is associated with transient hypertension and decreases of skin surface temperature that are closely correlated with the detrusor overactivity. With this cold stress model, we showed that α1-adrenergic receptor antagonists have the potential to treat cold stress-exacerbated lower urinary tract symptoms. In addition, we showed that traditional Japanese herbal mixtures composed of Hachimijiogan act, in part, by increasing skin temperature and reducing the number of cold sensitive transient receptor potential melastatin channels in the skin. The effects of herbal mixtures have the potential to treat and/or prevent the exacerbation of lower urinary tract symptoms by providing resistance to the cold stress responses. Our model provides new opportunities for utilizing animal disease models with altered lower urinary tract functions to explore the effects of novel therapeutic drugs. © 2013 The Japanese Urological Association.

Cold Antimatter Plasmas, and Aspirations for Cold Antihydrogen

Science.gov (United States)

2002-06-24

UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP012494 TITLE: Cold Antimatter Plasmas, and Aspirations for Cold...part numbers comprise the compilation report: ADP012489 thru ADP012577 UNCLASSIFIED Cold Antimatter Plasmas, and Aspirations for Cold Antihydrogen G...and positrons. The antiprotons come initially from the new Antiproton Decel- erator facility at CERN. Good control of such cold antimatter plasmas is

APS storage ring vacuum system performance

International Nuclear Information System (INIS)

Noonan, J.R.; Gagliano, J.; Goeppner, G.A.

1997-01-01

The Advanced Photon Source (APS) storage ring was designed to operated with 7-GeV, 100-mA positron beam with lifetimes > 20 hours. The lifetime is limited by residual gas scattering and Touschek scattering at this time. Photon-stimulated desorption and microwave power in the rf cavities are the main gas loads. Comparison of actual system gas loads and design calculations will be given. In addition, several special features of the storage ring vacuum system will be presented

Steel weldability. Underbead cold cracking

International Nuclear Information System (INIS)

Marquet, F.; Defourny, J.; Bragard, A.

1977-01-01

The problem of underbead cold cracking has been studied by the implant technique. This approach allows to take into account in a quantitative manner the different factors acting on the cold cracking phenomenon: structure under the weld bead, level of restraint, hydrogen content in the molten metal. The influence of the metallurgical factors depending from the chemical composition of the steel has been examined. It appeared that carbon equivalent is an important factor to explain cold cracking sensitivity but that it is not sufficient to characterize the steel. The results have shown that vanadium may have a deleterious effect on the resistance to cold cracking when the hydrogen content is high and that small silicon additions are beneficient. The influence of the diffusible hydrogen content has been checked and the important action of pre- and postheating has been shown. These treatments allow the hydrogen to escape from the weld before the metal has been damaged. Some inclusions (sulphides) may also decrease the influence of hydrogen. A method based on the implant tests has been proposed which allows to choose and to control safe welding conditions regarding cold cracking

Series fabrication of the main quadrupole cold masses for the LHC begins

CERN Multimedia

2003-01-01

Three hundred and sixty main quadrupole (MQ) magnets will perform the principal beam focusing around the 27 km LHC ring. CERN and CEA-Saclay began collaborating on the development and prototyping of these magnets in 1989. This resulted in five highly successful quadrupole units - also known as short straight sections - one of which was integrated for testing in String 1, and two others of the final design in String 2. Once the tests had confirmed the validity of the design and realization, the fabrication of the 360 cold masses had to be transferred to industry.The German firm ACCEL Instruments was entrusted both with the construction of the quadrupole magnets themselves, and with their assembly into the cold masses together with various combinations of corrector magnets produced by other European manufacturers. Here we see the first of the cold masses containing the MQ magnet of the machine arcs together with two types of corrector magnet ready for shipping to CERN. This first unit was delivered on 12 Februa...

Efficacy of zinc against common cold viruses: an overview.

Science.gov (United States)

Hulisz, Darrell

2004-01-01

To review the laboratory and clinical evidence of the medicinal value of zinc for the treatment of the common cold. Published articles identified through Medline (1980-2003) using the search terms zinc, rhinovirus, and other pertinent subject headings. Additional sources were identified from the bibliographies of the retrieved articles. By the author. By the author. Human rhinoviruses, by attaching to the nasal epithelium via the intracellular adhesion molecule-1 (ICAM-1) receptor, cause most colds. Ionic zinc, based on its electrical charge, also has an affinity for ICAM-1 receptor sites and may exert an antiviral effect by attaching to the ICAM-1 receptors in the rhinovirus structure and nasal epithelial cells. Clinical tests of zinc for treatment of common colds have been inconsistent, primarily because of study design, blinding, and lozenge contents. Early formulations of lozenges also were unpalatable. In three trials with similar study designs, methodologies, and efficacy assessments, zinc effectively and significantly shortened the duration of the common cold when it was administered within 24 hours of the onset of symptoms. Recent reports of trials with zinc gluconate administered as a nasal gel have supported these findings; in addition, they have shown that treatment with zinc nasal gel is effective in reducing the duration and severity of common cold symptoms in patients with established illness. Clinical trial data support the value of zinc in reducing the duration and severity of symptoms of the common cold when administered within 24 hours of the onset of common cold symptoms. Additional clinical and laboratory evaluations are warranted to further define the role of ionic zinc for the prevention and treatment of the common cold and to elucidate the biochemical mechanisms through which zinc exerts its symptom-relieving effects.

Hyperbranched polyglycerol as a colloid in cold organ preservation solutions.

Directory of Open Access Journals (Sweden)

Sihai Gao

Full Text Available Hydroxyethyl starch (HES is a common colloid in organ preservation solutions, such as in University of Wisconsin (UW solution, for preventing graft interstitial edema and cell swelling during cold preservation of donor organs. However, HES has undesirable characteristics, such as high viscosity, causing kidney injury and aggregation of erythrocytes. Hyperbranched polyglycerol (HPG is a branched compact polymer that has low intrinsic viscosity. This study investigated HPG (MW-0.5 to 119 kDa as a potential alternative to HES for cold organ preservation. HPG was synthesized by ring-opening multibranching polymerization of glycidol. Both rat myocardiocytes and human endothelial cells were used as an in vitro model, and heart transplantation in mice as an in vivo model. Tissue damage or cell death was determined by both biochemical and histological analysis. HPG polymers were more compact with relatively low polydispersity index than HES in UW solution. Cold preservation of mouse hearts ex vivo in HPG solutions reduced organ damage in comparison to those in HES-based UW solution. Both size and concentration of HPGs contributed to the protection of the donor organs; 1 kDa HPG at 3 wt% solution was superior to HES-based UW solution and other HPGs. Heart transplants preserved with HPG solution (1 kDa, 3% as compared with those with UW solution had a better functional recovery, less tissue injury and neutrophil infiltration in syngeneic recipients, and survived longer in allogeneic recipients. In cultured myocardiocytes or endothelial cells, significantly more cells survived after cold preservation with the HPG solution than those with the UW solution, which was positively correlated with the maintenance of intracellular adenosine triphosphate and cell membrane fluidity. In conclusion, HPG solution significantly enhanced the protection of hearts or cells during cold storage, suggesting that HPG is a promising colloid for the cold storage of donor organs

Hypothermic general cold adaptation induced by local cold acclimation.

Science.gov (United States)

Savourey, G; Barnavol, B; Caravel, J P; Feuerstein, C; Bittel, J H

1996-01-01

To study relationships between local cold adaptation of the lower limbs and general cold adaptation, eight subjects were submitted both to a cold foot test (CFT, 5 degrees C water immersion, 5 min) and to a whole-body standard cold air test (SCAT, 1 degree C, 2 h, nude at rest) before and after a local cold acclimation (LCA) of the lower limbs effected by repeated cold water immersions. The LCA induced a local cold adaptation confirmed by higher skin temperatures of the lower limbs during CFT and a hypothermic insulative general cold adaptation (decreased rectal temperature and mean skin temperature P adaptation was related to the habituation process confirmed by decreased plasma concentrations of noradrenaline (NA) during LCA (P general cold adaptation was unrelated either to local cold adaptation or to the habituation process, because an increased NA during SCAT after LCA (P syndrome" occurring during LCA.

A pulse tube cryocooler with a cold reservoir

Science.gov (United States)

Zhang, X. B.; Zhang, K. H.; Qiu, L. M.; Gan, Z. H.; Shen, X.; Xiang, S. J.

2013-02-01

Phase difference between pressure wave and mass flow is decisive to the cooling capacity of regenerative cryocoolers. Unlike the direct phase shifting using a piston or displacer in conventional Stirling or GM cryocoolers, the pulse tube cyocooler (PTC) indirectly adjusts the cold phase due to the absence of moving parts at the cold end. The present paper proposed and validated theoretically and experimentally a novel configuration of PTC, termed cold reservoir PTC, in which a reservoir together with an adjustable orifice is connected to the cold end of the pulse tube. The impedance from the additional orifice to the cold end helps to increase the mass flow in phase with the pressure wave at the cold end. Theoretical analyses with the linear model for the orifice and double-inlet PTCs indicate that the cooling performance can be improved by introducing the cold reservoir. The preliminary experiments with a home-made single-stage GM PTC further validated the results on the premise of minor opening of the cold-end orifice.

Cold Stress

Science.gov (United States)

... Publications and Products Programs Contact NIOSH NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir Workers who ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

Black rings

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)

Cold suppresses agonist-induced activation of TRPV1.

Science.gov (United States)

Chung, M-K; Wang, S

2011-09-01

Cold therapy is frequently used to reduce pain and edema following acute injury or surgery such as tooth extraction. However, the neurobiological mechanisms of cold therapy are not completely understood. Transient receptor potential vanilloid 1 (TRPV1) is a capsaicin- and heat-gated nociceptive ion channel implicated in thermosensation and pathological pain under conditions of inflammation or injury. Although capsaicin-induced nociception, neuropeptide release, and ionic currents are suppressed by cold, it is not known if cold suppresses agonist-induced activation of recombinant TRPV1. We demonstrate that cold strongly suppressed the activation of recombinant TRPV1 by multiple agonists and capsaicin-evoked currents in trigeminal ganglia neurons under normal and phosphorylated conditions. Cold-induced suppression was partially impaired in a TRPV1 mutant that lacked heat-mediated activation and potentiation. These results suggest that cold-induced suppression of TRPV1 may share a common molecular basis with heat-induced potentiation, and that allosteric inhibition may contribute, in part, to the cold-induced suppression. We also show that combination of cold and a specific antagonist of TRPV1 can produce an additive suppression. Our results provide a mechanistic basis for cold therapy and may enhance anti-nociceptive approaches that target TRPV1 for managing pain under inflammation and tissue injury, including that from tooth extraction.

The ring plus project: safety and acceptability of vaginal rings that protect women from unintended pregnancy.

Science.gov (United States)

Schurmans, Céline; De Baetselier, Irith; Kestelyn, Evelyne; Jespers, Vicky; Delvaux, Thérèse; Agaba, Stephen K; van Loen, Harry; Menten, Joris; van de Wijgert, Janneke; Crucitti, Tania

2015-04-10

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 and pregnancy have been elaborated. In contrast with the CVRs, multi-purpose vaginal rings will have to be used continuously. Women who continuously use a CVR will no longer have menses. Furthermore, some safety aspects of CVR use have never been studied in-depth in the past, such as the impact of the vaginal ring on the vaginal microbiota, biofilm formation and induction of inflammation. We studied acceptability and these novel aspects of safety in Rwandan women. Although significant progress has been made over the past decade, Rwanda still has a high unmet need for contraception (with 47% unplanned births) and a generalized HIV epidemic, and CVRs are not yet available. We will conduct an open label, single centre, randomized controlled trial. A total of 120 HIV-negative women will be randomized to intermittent CVR use (to allow menstruation) or continuous CVR use. Women will be followed for a maximum of 14 weeks. In parallel, we will conduct a qualitative study using in-depth interview and focus group discussion methodology. In addition to evaluating the safety and acceptability of intermittent and continuous CVR use in Rwandan women, we hope that our findings will inform the development of future multipurpose vaginal rings, will prepare Rwandan study populations for future clinical trials of multipurpose vaginal rings, and will pave the way for introduction of CVRs on African markets. Clinicaltrials.gov NCT01796613 . Registered 14 February 2013.

Punchless Drawing of Magnesium Alloy Sheet under Cold Condition and its Computation

International Nuclear Information System (INIS)

Yamashita, Minoru; Hattori, Toshio; Sato, Joji

2011-01-01

The punchless drawing with Maslennikov's technique was applied to the circular cup drawing of magnesium alloy AZ31B sheet under cold condition. The elastic rubber ring was used instead of the 'hard' punch, where the compressed ring dragged the sheet inward the die cavity. Attainable circumferential strain of the blank was increased by this technique with repetitive drawing operation. Thickness of the rubber pad affected little the attainable strain. The shape appearance became better when a harder rubber was used. The cup forming by single drawing operation was also tested using a small die shoulder radius. The LDR of 1.250 was obtained with the straight cup wall. Further, the computation of the punchless drawing was also conducted for the single drawing operation. The computed deformation pattern was well consistent with the corresponding experimental result.

Variations in Ring Particle Cooling across Saturn's Rings with Cassini CIRS

Science.gov (United States)

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.

An improved red blood cell additive solution maintains 2,3-diphosphoglycerate and adenosine triphosphate levels by an enhancing effect on phosphofructokinase activity during cold storage.

Science.gov (United States)

Burger, Patrick; Korsten, Herbert; De Korte, Dirk; Rombout, Eva; Van Bruggen, Robin; Verhoeven, Arthur J

2010-11-01

Current additive solutions (ASs) for red blood cells (RBCs) do not maintain constant 2,3-diphosphoglycerate (DPG) and adenosine triphosphate (ATP) levels during cold storage. We have previously shown that with a new AS called phosphate-adenine-glucose-guanosine-gluconate-mannitol (PAGGGM), both 2,3-DPG and ATP could be maintained throughout storage for 35 days. In this study, the mechanism underlying the effect of PAGGGM on RBC storage was studied in more detail. By using double-erythrocytapheresis units (leukoreduced), a direct comparison could be made between the current AS saline-adenine-glucose-mannitol (SAGM) and the experimental solution PAGGGM. During cold storage, several in vitro characteristics were analyzed. In agreement with our previous findings with single RBCs, PAGGGM maintained 2,3-DPG and ATP levels for 35 days of cold storage. Furthermore, glucose consumption and lactate production were higher in PAGGGM units during the first 21 days of cold storage. Fructose-1,6-diphophate and dihydroxyacetone phosphate levels were also increased during the first 21 days of storage in PAGGGM units. These results indicate that it is likely that phosphofructokinase (PFK) activity is enhanced in PAGGGM units relative to SAGM units. After 21 days, PFK activity also decreases in PAGGGM units, but sufficient metabolic reserve in these units prevents depletion of 2,3-DPG and ATP. © 2010 American Association of Blood Banks.

Cottonwood Tree Rings and Climate in Western North America

Science.gov (United States)

Friedman, J. M.; Edmondson, J.; Griffin, E. R.; Meko, D. M.; Merigliano, M. F.; Scott, J. A.; Scott, M. L.; Touchan, R.

2012-12-01

In dry landscapes of interior western USA, cottonwood (Populus spp.) seedling establishment often occurs only close to river channels after floods. Where winter is sufficiently cold, cottonwoods also have distinct annual rings and can live up to 370 years, allowing us to reconstruct the long-term history of river flows and channel locations. We have analyzed the annual rate of cottonwood establishment along streams in Montana, Wyoming, Colorado, North Dakota and Idaho. Because the trees germinate next to the river, establishment rates are strongly correlated with the rate of channel migration driven by floods. Along large rivers dominated by snowmelt from the mountains, interannual variation in peak flows and cottonwood establishment is small, and century-scale variation driven by climate change is apparent. The upper Snake, Yellowstone and Green rivers all show a strong decrease in cottonwood establishment beginning in the late 1800s and continuing to the present, indicating a decrease in peak flows prior to flow regulation by large dams. This is consistent with published tree-ring studies of montane conifers showing decreases in snowpack at the same time scale. In contrast, beginning in the late 1800s cottonwood ring widths along the Little Missouri River, North Dakota show an increase in annual growth that continues into the present. Because annual growth is strongly correlated with April-July flows (r=0.69) the ring-width data suggest an increase in April-July flows at the same time tree establishment dates suggest a decrease in peak flows. These results may be reconciled by the hypothesis that increases in low temperatures have decreased snowpack while lengthening the growing season.

Supernumerary ring chromosome 20 characterized by fluorescence in situ hybridization

NARCIS (Netherlands)

Van Langen, Irene M.; Otter, Mariëlle A.; Aronson, Daniël C.; Overweg-Plandsoen, W.C.G.; Hennekam, Raoul C.M.; Leschot, Nico J.; Hoovers, Jan M.N.

1996-01-01

We report on a boy with mild dysmorphic features and developmental delay, in whom karyotyping showed an additional minute ring chromosome in 60% of metaphases. Fluorescence in situ hybridization (FISH) with a centromere specific probe demonstrated that the ring chromosome contained the centromeric

Alternative loop rings

CERN Document Server

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

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

Finger cold-induced vasodilation of older Korean female divers, haenyeo: effects of chronic cold exposure and aging

Science.gov (United States)

Lee, Joo-Young; Park, Joonhee; Koh, Eunsook; Cha, Seongwon

2017-07-01

The aim of the present study was to evaluate the local cold tolerance of older Korean female divers, haenyeo ( N = 22) in terms of cold acclimatization and ageing. As control groups, older non-diving females ( N = 25) and young females from a rural area ( N = 15) and an urban area ( N = 51) participated in this study. To evaluate local cold tolerance, finger cold-induced vasodilation (CIVD) during finger immersion of 4 °C water was examined. As a result, older haenyeos showed greater minimum finger temperature and recovery finger temperature than older non-diving females ( P < 0.05), but similar responses in onset time, peak time, maximum finger temperature, frequency of CIVD, heart rate, blood pressure, and thermal and pain sensations as those of older non-diving females. Another novel finding was that young urban females showed more vulnerable responses to local cold in CIVD variables and subjective sensations when compared to older females, whereas young rural females had the most excellent cold tolerance in terms of maximum temperature and frequency of CIVD among the four groups ( P < 0.05). The present results imply that older haenyeos still retain cold acclimatized features on the periphery even though they changed their cotton diving suits to wet suits in the early 1980s. However, cardiovascular responses and subjective sensations to cold reflect aging effects. In addition, we suggest that young people who have been adapted to highly insulated clothing and indoor heating systems in winter should be distinguished from young people who were exposed to less modern conveniences when compared to the aged in terms of cold tolerance.

Modeling of anisotropic properties of double quantum rings by the terahertz laser field.

Science.gov (United States)

Baghramyan, Henrikh M; Barseghyan, Manuk G; Kirakosyan, Albert A; Ojeda, Judith H; Bragard, Jean; Laroze, David

2018-04-18

The rendering of different shapes of just a single sample of a concentric double quantum ring is demonstrated realizable with a terahertz laser field, that in turn, allows the manipulation of electronic and optical properties of a sample. It is shown that by changing the intensity or frequency of laser field, one can come to a new set of degenerated levels in double quantum rings and switch the charge distribution between the rings. In addition, depending on the direction of an additional static electric field, the linear and quadratic quantum confined Stark effects are observed. The absorption spectrum shifts and the additive absorption coefficient variations affected by laser and electric fields are discussed. Finally, anisotropic electronic and optical properties of isotropic concentric double quantum rings are modeled with the help of terahertz laser field.

Friction and wear properties of Ti6Al4V/WC-Co in cold atmospheric plasma jet

International Nuclear Information System (INIS)

Xu Wenji; Liu Xin; Song Jinlong; Wu Libo; Sun Jing

2012-01-01

Highlights: ► Cold plasma jet can effectively reduce the friction coefficients of Ti6Al4V/WC-Co friction pairs. ► Cold plasma jet can easily form nitrides on the surface of Ti6Al4V and on new surfaces generated by tool wear. ► The nitrides can reduce the friction coefficients and protect the friction surface. - Abstract: The friction and wear properties of Ti6Al4V/WC-Co friction pair were studied using an autonomous atmospheric pressure bare electrode cold plasma jet generating device and block-on-ring friction/wear tester, respectively. The study was conducted under air, air jet, nitrogen jet, air cold plasma jet, and nitrogen cold plasma jet atmospheres. Both nitrogen cold and air cold plasma jets effectively reduced the friction coefficients of the friction pairs and decreased friction temperature. The friction coefficient in the nitrogen cold plasma jet decreased to almost 60% compared with that in the air. The scanning electron microscope, energy-dispersive X-ray spectroscope, and X-ray diffraction analyses illustrated that adhesive wear was relieved and the friction surfaces of Ti6Al4V were smoother, both in the nitrogen cold and air cold plasma jets. The roughness value R a of the Ti6Al4V friction surfaces can reach 1.107 μm. A large number of nitrogen particles in the ionic and excited states contained by cold plasma jets reacts easily on the friction surface to produce a large amount of nitrides, which can excellently reduce the wear of Ti6Al4V/WC-Co friction pairs in real-time.

Vortex formation in narrow ferromagnetic rings

International Nuclear Information System (INIS)

Klaeui, M; Vaz, C A F; Lopez-Diaz, L; Bland, J A C

2003-01-01

The high-symmetry ring geometry is shown to exhibit a wide range of intriguing magnetostatic and magnetodynamic properties, which we survey in this topical review. We consider first the patterning and deposition techniques, which are used to fabricate ring structures (diameters between 0.1 and 2 μm) and discuss their respective advantages and disadvantages. The results of direct nanoscale imaging of the novel magnetization configurations present in rings with different geometrical parameters (including discs) are discussed. These results give valuable insight into the influence of the magnetic anisotropies governing the magnetic states. The different types of domain walls that arise are compared quantitatively to micromagnetic simulations. The magnetodynamic switching between the different magnetic states is described in detail. In particular we elaborate on the different geometry-dependent magnetic switchings, since the different transitions occurring allow us to determine which energy terms govern the reversal process. We discuss a process by which fast (sub-ns) and controlled switching can be achieved, therefore making rings an attractive geometry for applications, in addition to studying fundamental issues of nanomagnetism. (topical review)

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

Characterisation of protein stability in rod-insert vaginal rings.

Science.gov (United States)

Pattani, Aditya; Lowry, Deborah; Curran, Rhonda M; McGrath, Stephanie; Kett, Vicky L; Andrews, Gavin P; Malcolm, R Karl

2012-07-01

A major goal in vaccine development is elimination of the 'cold chain', the transport and storage system for maintenance and distribution of the vaccine product. This is particularly pertinent to liquid formulation of vaccines. We have previously described the rod-insert vaginal ring (RiR) device, comprising an elastomeric body into which are inserted lyophilised, rod-shaped, solid drug dosage forms, and having potential for sustained mucosal delivery of biomacromolecules, such as HIV envelope protein-based vaccine candidates. Given the solid, lyophilised nature of these insert dosage forms, we hypothesised that antigen stability may be significantly increased compared with more conventional solubilised vaginal gel format. In this study, we prepared and tested vaginal ring devices fitted with lyophilised rod inserts containing the model antigen bovine serum albumin (BSA). Both the RiRs and the gels that were freeze-dried to prepare the inserts were evaluated for BSA stability using PAGE, turbidimetry, microbial load, MALDI-TOF and qualitative precipitate solubility measurements. When stored at 4 °C, but not when stored at 40 °C/75% RH, the RiR formulation offered protection against structural and conformational changes to BSA. The insert also retained matrix integrity and release characteristics. The results demonstrate that lypophilised gels can provide relative protection against degradation at lower temperatures compared to semi-solid gels. The major mechanism of degradation at 40 °C/75% RH was shown to be protein aggregation. Finally, in a preliminary study, we found that addition of trehalose to the formulation significantly reduces the rate of BSA degradation compared to the original formulation when stored at 40 °C/75% RH. Establishing the mechanism of degradation, and finding that degradation is decelerated in the presence of trehalose, will help inform further development of RiRs specifically and polymer based freeze-dried systems in general. Copyright

New graft sizing rings for aortic valve reimplantation procedures.

Science.gov (United States)

Jelenc, Matija; Jelenc, Blaž; Kneževic, Ivan; Klokocovnik, Tomislav

2018-01-01

The objective was to design sizing rings that would enable proper sizing of the graft in reimplantation procedures and to perform leaflet repair before graft implantation. The rings were designed in Autodesk Fusion 360 (San Rafael, CA, USA) and 3D printed using a commercial online 3D printing service. We designed incomplete rings with a low profile and complete rings with a high profile. The complete rings are best suited for reimplantation procedures, whereas low profile C rings are intended for isolated aortic valve repair, where the ascending aorta is not transected. The rings come in sizes corresponding to Vascutek Gelweave graft sizes (Vascutek Terumo, Renfrewshire, Scotland). The ring internal diameters are 5% larger than the designated ring sizes and account for the 5% stretch of the grafts when pressurized. Blades of the rings are placed at 20° intervals. The slits between the blades are designed in such a way that the commissural U-sutures, when put in place and under tension, will lock the ring in position. The rings were successfully used in 10 of our latest reimplantation procedures. After dissection of the aortic root, the commissures were suspended with U-stitches and then the ring was seated onto them. Complete leaflet repair with plication to achieve adequate effective height was then performed, followed by graft implantation. No additional leaflet repair was needed. The newly designed sizing rings enable proper sizing of the graft in reimplantation procedures and enable complete leaflet repair before graft implantation. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Cold injuries.

Science.gov (United States)

Kruse, R J

1995-01-01

There are two categories of cold injury. The first is hypothermia, which is a systemic injury to cold, and the second is frostbite, which is a local injury. Throughout history, entire armies, from George Washington to the Germans on the Russian Front in World War II, have fallen prey to prolonged cold exposure. Cold injury is common and can occur in all seasons if ambient temperature is lower than the core body temperature. In the 1985 Boston Marathon, even though it was 76 degrees and sunny, there were 75 runners treated for hypothermia. In general, humans adapt poorly to cold exposure. Children are at particular risk because of their relatively greater surface area/body mass ratio, causing them to cool even more rapidly than adults. Because of this, the human's best defense against cold injury is to limit his/her exposure to cold and to dress appropriately. If cold injury has occurred and is mild, often simple passive rewarming such as dry blankets and a warm room are sufficient treatment.

Influence of oil starvation on piston ring oil film thickness; Junkatsuyu kyokyuryo fusoku ga ring yumaku ni ataeru eikyo

Energy Technology Data Exchange (ETDEWEB)

Hiruma, M [Musashi Institute of Technology, Tokyo (Japan). Hydrogen Energy Research Center; Takiguchi, M [Musashi Institute of Technology, Tokyo (Japan)

1997-10-01

An analytical behavior of the piston ring oil film has been carried out theoretically under the condition where sufficient lubrication oil dose not exist. Phenomena have been studied on the oil film when plural rings slide together on the surface of cylinder with a new concept in addition to the well-known assumptions. In particular, a comparison has been made on the friction force with the data obtained by the floating liner method. 5 refs., 9 figs.

Proposal for the Purchase, Without a New Call for Tenders, of Four Additional Superconducting Quadrupole Magnets for the Duplication of the Low-Beta Insertion of the CERN Intersecting Storage Rings (ISR)

CERN Document Server

1978-01-01

Proposal for the Purchase, Without a New Call for Tenders, of Four Additional Superconducting Quadrupole Magnets for the Duplication of the Low-Beta Insertion of the CERN Intersecting Storage Rings (ISR)

Structure of the cold- and menthol-sensing ion channel TRPM8.

Science.gov (United States)

Yin, Ying; Wu, Mengyu; Zubcevic, Lejla; Borschel, William F; Lander, Gabriel C; Lee, Seok-Yong

2018-01-12

Transient receptor potential melastatin (TRPM) cation channels are polymodal sensors that are involved in a variety of physiological processes. Within the TRPM family, member 8 (TRPM8) is the primary cold and menthol sensor in humans. We determined the cryo-electron microscopy structure of the full-length TRPM8 from the collared flycatcher at an overall resolution of ~4.1 ångstroms. Our TRPM8 structure reveals a three-layered architecture. The amino-terminal domain with a fold distinct among known TRP structures, together with the carboxyl-terminal region, forms a large two-layered cytosolic ring that extensively interacts with the transmembrane channel layer. The structure suggests that the menthol-binding site is located within the voltage-sensor-like domain and thus provides a structural glimpse of the design principle of the molecular transducer for cold and menthol sensation. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Bunch lengthening in the SLC [Stanford Linear Collider] damping rings

International Nuclear Information System (INIS)

Bane, K.L.F.

1990-02-01

A high level of current dependent bunch lengthening has been observed on the North damping ring of the Stanford Linear Collider (SLC). At currents of 3 x 10 10 this behavior does not appear to degrade the machine's performance significantly. However, at the higher currents that are envisioned for the future one fears that its performance could be greatly degraded due to the phenomenon of bunch lengthening. This was the motivation for the work described in this paper. In this paper we calculate the longitudinal impedance of the damping ring vacuum chamber. More specifically, in this paper we find the response function of the ring to a short Gaussian bunch, which we call the Green function wake. In addition, we try to estimate the relative importance of the different vacuum chamber objects, in order to see how we might reduce the ring impedance. This paper also describes bunch length measurements performed on the North damping ring. We use the Green function wake, discussed above, to compute the bunch lengthening. Then we compare these results with those obtained from the measurements. In addition, we calculate the current dependence of the tune distribution

Rings in drugs.

Science.gov (United States)

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.

Refined liquid smoke: a potential antilisterial additive to cold-smoked sockeye salmon (Oncorhynchus nerka).

Science.gov (United States)

Montazeri, Naim; Himelbloom, Brian H; Oliveira, Alexandra C M; Leigh, Mary Beth; Crapo, Charles A

2013-05-01

Cold-smoked salmon (CSS) is a potentially hazardous ready-to-eat food product due to the high risk of contamination with Listeria monocytogenes and lack of a listericidal step. We investigated the antilisterial property of liquid smokes (LS) against Listeria innocua ATCC 33090 (surrogate to L. monocytogenes) as a potential supplement to vacuum-packaged CSS. A full-strength LS (Code 10-Poly), and three commercially refined fractions (AM-3, AM-10, and 1291) having less color and flavor (lower content of phenols and carbonyl-containing compounds) were tested. In vitro assays showed strong inhibition for all LS except for 1291. The CSS strips were surface coated with AM-3 and AM-10 at 1% LS (vol/wt) with an L-shaped glass rod and then inoculated with L. innocua at 3.5 log CFU/g, vacuum packaged, and stored at 4°C. The LS did not completely eliminate L. innocua but provided a 2-log reduction by day 14, with no growth up to 35 days of refrigerated storage. A simple difference sensory test by 180 untrained panelists showed the application of AM-3 did not significantly influence the overall sensorial quality of CSS. In essence, the application of the refined LS as an antilisterial additive to CSS is recommended.

TSR: A Storage Ring for HIE-ISOLDE

CERN Document Server

Butler, P A; Blaum, K; Grieser, M; Davinson, T; Woods, P J; Flanagan, K; Freeman, S J; Lazarus, I H; Litvinov, Yu A; Raabe, R; Siesling, E; Wenander, F

2016-01-01

It is planned to install the heavy-ion, low-energy ring TSR, currently at the Max-Planck-Institute for Nuclear Physics in Heidelberg, at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored, cooled secondary beams that is rich and varied, spanning from studies of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. In addition to experiments performed using beams recirculating within the ring, the cooled beams can be extracted and exploited by external spectrometers for high-precision measurements. The capabilities of the ring facility as well as some physics cases will be presented, together with a brief report on the status of the project.

Influence of cold deformation and annealing on hydrogen embrittlement of cold hardening bainitic steel for high strength bolts

Energy Technology Data Exchange (ETDEWEB)

Hui, Weijun, E-mail: wjhui@bjtu.edu.cn [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Zhang, Yongjian; Zhao, Xiaoli; Shao, Chengwei [School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Wang, Kaizhong; Sun, Wei; Yu, Tongren [Technical Center, Maanshan Iron & Steel Co., Ltd., Maanshan 243002, Anhui (China)

2016-04-26

The influence of cold drawing and annealing on hydrogen embrittlement (HE) of newly developed cold hardening bainitic steel was investigated by using slow strain rate testing (SSRT) and thermal desorption spectrometry (TDS), for ensuring safety performance of 10.9 class high strength bolts made of this kind of steel against HE under service environments. Hydrogen was introduced into the specimen by electrochemical charging. TDS analysis shows that the hydrogen-charged cold drawn specimen exhibits an additional low-temperature hydrogen desorption peak besides the original high-temperature desorption peak of the as-rolled specimen, causing remarkable increase of absorbed hydrogen content. It is found that cold drawing significantly enhances the susceptibility to HE, which is mainly attributed to remarkable increase of diffusible hydrogen absorption, the occurrence of strain-induced martensite as well as the increase of strength level. Annealing after cold deformation is an effective way to improve HE resistance and this improvement strongly depends on annealing temperature, i.e. HE susceptibility decreases slightly with increasing annealing temperature up to 200 °C and then decreases significantly with further increasing annealing temperature. This phenomenon is explained by the release of hydrogen, the recovery of cold worked microstructure and the decrease of strength with increasing annealing temperature.

Influence of selected factors on bovine spermatozoa cold shock resistance

Directory of Open Access Journals (Sweden)

Luděk Stádník

2015-01-01

Full Text Available The objectives of this study were to determine the effects of sire, extender, and addition of Low Density Lipoprotein (LDL to extenders used on the percentage rate of spermatozoa survival after cold shock. Two groups of extenders were compared: without LDL addition (control variants and LDL enriched (experimental variants. Three extenders were used: AndroMed®, Bioxcell®, and Triladyl®. Experimental variants included 4–8% LDL addition into the AndroMed® and Bioxcell® extenders, and 6–10% LDL addition into the Triladyl® extender. In total, 12 samples of fresh semen were collected from 4 bulls during a period of 8 weeks. Bovine spermatozoa cold shock resistance (1 ± 1 °C, 10 min was evaluated by the percentage rate of live sperm using eosin-nigrosine staining immediately and after heat incubation (37 ± 1 °C, 120 min. The results showed the effect of sire as important and individual differences between selected sires in their sperm resistance against cold shock were confirmed. AndroMed® and Bioxcell® were found to be providing better protection of bull semen to cold shock compared to Triladyl® due to lower decline of live sperm proportion. Our results detected a positive effect of LDL addition on sperm resistance against cold shock, especially on lower decrease of live sperm percentage rate after 120 min of the heat test (P < 0.05. Further studies are needed to assess the optimal concentration of LDL in various kinds of extenders as well to state ideal time and temperature conditions for ensuring LDL reaction with sperm.

OTEC LSCT study, additional work. Final report

Energy Technology Data Exchange (ETDEWEB)

1980-12-01

In the final stage of the Large Systems Construction Techniques (LSCT) study, work on the elastomer cold water pipe and on the design of power modules for the Sparmod platform concept was performed. Six different configurations of pipe are compared, and the pressure difference between the outside and inside of the pipe is analyzed. Static forces in the membrane are also discussed. Calculation of the strength and stability of concrete rings are done. The forces, membrane materials and connection details of the elastomer membrane of the pipe are discussed. Construction and handling of the pipe and rings are discussed, and a rough breakdown of the costs for a 30 m diameter pipe is given. The consequences of the sparmod principles to the OTEC-plant design are investigated. Conceptual design of a 50 MW power module for the 400 MW sparmod design was done, followed by a construction and installation plan. Conceptual design of a 50 MW and 100 MW Plant based on the sparmod principle is done to investigate the influence of scale. (LEW)

Inductive fault current limiter based on multiple superconducting rings of small diameter

International Nuclear Information System (INIS)

Osorio, M R; Cabo, L; Veira, J A; Vidal, F

2004-01-01

We present a fault current limiter prototype based on the use of a secondary comprised of an array of magnetic cores of small sections, each one of them with several superconducting rings. The main advantage of this configuration is that it is easier to make small diameter superconducting rings which, in addition, are more homogeneous and allow better refrigeration. We then present detailed measurements that show that, in addition to these advantages, this prototype offers the same limitation performances than when using a unique core and a superconducting ring with an equivalent area as the array of small section cores

Cold hypersensitivity increases with age in mice with sickle cell disease

Science.gov (United States)

Zappia, Katherine J.; Garrison, Sheldon R.; Hillery, Cheryl A.; Stucky, Cheryl L.

2014-01-01

Sickle cell disease (SCD) is associated with acute vaso-occlusive crises that trigger painful episodes and frequently involves ongoing, chronic pain. Additionally, both humans and mice with SCD experience heighted cold sensitivity. However, studies have not addressed the mechanism(s) underlying the cold sensitization, nor its progression with age. Here we measured thermotaxis behavior in young and aged mice with severe SCD. Sickle mice had a marked increase in cold sensitivity measured by a cold preference test. Further, cold hypersensitivity worsened with advanced age. We assessed whether enhanced peripheral input contributes to the chronic cold pain behavior by recording from C fibers, many of which are cold-sensitive, in skin-nerve preparations. We observed that C fibers from sickle mice displayed a shift to warmer (more sensitive) cold-detection thresholds. To address mechanisms underlying the cold sensitization in primary afferent neurons, we quantified mRNA expression levels for ion channels thought to be involved in cold detection. These included the Transient Receptor Potential Melastatin 8 (Trpm8) and TRP Ankyrin 1 (Trpa1) channels, as well as the two-pore domain potassium channels, TREK-1 (Kcnk2), TREK-2 (Kcnk4), and TRAAK (Kcnk10). Surprisingly, transcript expression levels of all of these channels were comparable between sickle and control mice. We further examined transcript expression of 83 additional pain-related genes and found increased mRNA levels for endothelin 1 and tachykinin receptor 1. These factors may contribute to hypersensitivity in sickle mice at both the afferent and behavioral levels. Sensory neurons from sickle cell disease mice are sensitized to cold, mirroring behavioral observations, and have increased expression of endothelin 1 and tachykinin receptor 1. PMID:24953902

Spectrophotometry of ring nebulae around Wolf-Rayet stars

International Nuclear Information System (INIS)

Kwitter, K.B.

1979-01-01

Spectrophotometric observations of four ring nebulae surrounding population I Wolf-Rayet (WN) stars have been obtained, and four additional filamentary nebulae in order to determine the physical conditions and chemical abundances in these objects. It was concluded that the ring nebulae are enriched in nitrogen and helium as a result of contamination of the ambient interstellar medium by the helium- and nitrogen-rich wind from the central Wolf-Rayet star. Of the additional nebulae studied, two were found to be Peimbert Type I planetary nebulae, overabundant in nitrogen and helium due to mixing of CNO processed material into the parent envelope prior to ejection. One of the remaining objects, a shell around an Oef star, is found to have normal abundances; the other, a small H II region around an early Be star, also exhibits normal abundances. It was attempted to interpret the ring nebulae and the Oef shell as interstellar bubbles, according to recent theory; it met with varying degrees of success. For two of the ring nebulae, the fraction of nebular mass contributed by the central star can be estimated from published stellar abundances. It was found that in these two cases, the stellar wind has provided less than 10% of the observed nebular mass

Cold-inducible RNA-binding protein mediates cold air inducible airway mucin production through TLR4/NF-κB signaling pathway.

Science.gov (United States)

Chen, Lingxiu; Ran, Danhua; Xie, Wenyue; Xu, Qing; Zhou, Xiangdong

2016-10-01

Mucus overproduction is an important feature in patients with chronic inflammatory airway diseases and cold air stimulation has been shown to be associated with the severity of these diseases. However, the regulatory mechanisms that mediate excessive mucin production under cold stress remain elusive. Recently, the cold-inducible RNA-binding protein (CIRP) has been shown to be markedly induced after exposure to cold air. In this study, we sought to explore the expression of CIRP within bronchial biopsy specimens, the effect on mucin5AC (MUC5AC) production in chronic inflammatory airway diseases and the potential signaling pathways involved in cold air stimulation process. We found that CIRP protein expression was significantly increased in patients with COPD and in mice treated with cold air. Moreover, cold air stimulation induced MUC5AC expression in wild-type mice but not in CIRP(-/-) mice. In vitro, cold air stress significantly elevated the transcriptional and protein expression levels of MUC5AC in human bronchial epithelial cells. CIRP, toll-like receptor 4 (TLR4) and phosphorylated NF-κB p65 (p-p65) increased significantly in response to cold stress and CIRP siRNA, TLR4 - neutralizing Ab and a specific inhibitor of NF-κB could attenuated cold stress inducible MUC5AC expression. In addition, CIRP siRNA could hindered the expression levels of TLR4 and p-p65 both induced by cold stress. Taken together, these results suggest that airway epithelial cells constitutively express CIRP in vitro and in vivo. CIRP is responsible for cold-inducible MUC5AC expression by activating TLR4/NF-κB signaling pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

Chemical Sensors Based on Optical Ring Resonators

Science.gov (United States)

Homer, Margie; Manfreda, Allison; Mansour, Kamjou; Lin, Ying; Ksendzov, Alexander

2005-01-01

Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong evanescent-wave coupling between the outer polymer layer and the electromagnetic field propagating along the waveguide core. By virtue of this coupling, the chemically induced change in index of refraction of the polymer causes a measurable shift in the resonance peaks of the ring. In a prototype that has been used to demonstrate the feasibility of this sensor concept, the ring resonator is a dielectric optical waveguide laid out along a closed path resembling a racetrack (see Figure 1). The prototype was fabricated on a silicon substrate by use of standard techniques of thermal oxidation, chemical vapor deposition, photolithography, etching, and spin coating. The prototype resonator waveguide features an inner cladding of SiO2, a core of SixNy, and a chemical-sensing outer cladding of ethyl cellulose. In addition to the ring Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong

Hereditary noetherian prime rings and idealizers

CERN Document Server

Levy, Lawrence S

2011-01-01

The direct sum behaviour of its projective modules is a fundamental property of any ring. Hereditary Noetherian prime rings are perhaps the only noncommutative Noetherian rings for which this direct sum behaviour (for both finitely and infinitely generated projective modules) is well-understood, yet highly nontrivial. This book surveys material previously available only in the research literature. It provides a re-worked and simplified account, with improved clarity, fresh insights and many original results about finite length modules, injective modules and projective modules. It culminates in the authors' surprisingly complete structure theorem for projective modules which involves two independent additive invariants: genus and Steinitz class. Several applications demonstrate its utility. The theory, extending the well-known module theory of commutative Dedekind domains and of hereditary orders, develops via a detailed study of simple modules. This relies upon the substantial account of idealizer subrings wh...

White Ring; White ring

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.

Token Ring Project

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

Development of dapivirine vaginal ring for HIV prevention.

Science.gov (United States)

Devlin, Bríd; Nuttall, Jeremy; Wilder, Susan; Woodsong, Cynthia; Rosenberg, Zeda

2013-12-01

In the continuing effort to develop effective HIV prevention methods for women, a vaginal ring containing the non-nucleoside reverse transcriptase inhibitor dapivirine is currently being tested in two safety and efficacy trials. This paper reviews dapivirine ring's pipeline development process, including efforts to determine safe and effective dosing levels as well as identify delivery platforms with the greatest likelihood of success for correct and consistent use. Dapivirine gel and other formulations were developed and tested in preclinical and clinical studies. Multiple vaginal ring prototypes were also tested, resulting in the current ring design as well as additional designs under consideration for future testing. Efficacy results from clinical trials are expected in 2015. Through ongoing consultations with national regulatory authorities, licensure requirements for dapivirine vaginal ring approval have been defined. This article is based on a presentation at the "Product Development Workshop 2013: HIV and Multipurpose Prevention Technologies," held in Arlington, Virginia on February 21-22, 2013. It forms part of a special supplement to Antiviral Research. Copyright © 2013 Elsevier B.V. All rights reserved.

Semi-algebraic function rings and reflectors of partially ordered rings

CERN Document Server

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.

Condensation of galactic cold dark matter

International Nuclear Information System (INIS)

Visinelli, Luca

2016-01-01

We consider the steady-state regime describing the density profile of a dark matter halo, if dark matter is treated as a Bose-Einstein condensate. We first solve the fluid equation for “canonical” cold dark matter, obtaining a class of density profiles which includes the Navarro-Frenk-White profile, and which diverge at the halo core. We then solve numerically the equation obtained when an additional “quantum pressure” term is included in the computation of the density profile. The solution to this latter case is finite at the halo core, possibly avoiding the “cuspy halo problem” present in some cold dark matter theories. Within the model proposed, we predict the mass of the cold dark matter particle to be of the order of M_χc"2≈10"−"2"4 eV, which is of the same order of magnitude as that predicted in ultra-light scalar cold dark matter models. Finally, we derive the differential equation describing perturbations in the density and the pressure of the dark matter fluid.

Electronic properties of superlattices on quantum rings.

Science.gov (United States)

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.

Rotating ring-ring electrode theory and experiment

NARCIS (Netherlands)

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

Radioecological investigations on tree rings of spruce

International Nuclear Information System (INIS)

Haas, G.; Mueller, A.

1995-01-01

Tree ring analysis contributes essentially to the explanation of physiological and element-specific transport phenomena in trees. After the accident in Chernobyl the behaviour of Cs-134 and Cs-137 in trees is most informative for the prediction of the future development of the distribution of these elements. In this study the uptake and the long term behaviour of Cs-134, Cs-137, Pb-210, Ra-226, Ra-228, K-40, Th-228, Th-230, Th-232, U-234 and U-238 in tree rings of spruce are examined by α- and γ-spectrometry. All samples are dried at 105C and ashed at 450C in a muffle furnace. The distributions found in the tree rings vary for different radionuclides. A soil profile from the spruce stand provides additional information

An optimum cold end configuration for helium liquefaction cycles

International Nuclear Information System (INIS)

Minta, M.; Smith, J.L.

1984-01-01

This chapter examines the effect of the non-ideal behavior of helium at low temperature on the performance of helium liquefaction cycles. The effect is isolated by means of a continuum model for the precooling stage. The cold end losses are due primarily to the composite effect of the non-ideality of helium at low temperatures and the heat exchanger losses, in addition to the component losses fixed by the expander/compressor efficiencies. Topics considered include continuously distributed full-pressure ratio expanders, continuously distributed full-flow expanders, the heat exchange effect (ideal gas working fluid, real gas working fluid), and cold end configuration. The cold end configuration minimizes the cycle cold end losses

Cold plate

Energy Technology Data Exchange (ETDEWEB)

Marroquin, Christopher M.; O' Connell, Kevin M.; Schultz, Mark D.; Tian, Shurong

2018-02-13

A cold plate, an electronic assembly including a cold plate, and a method for forming a cold plate are provided. The cold plate includes an interface plate and an opposing plate that form a plenum. The cold plate includes a plurality of active areas arranged for alignment over respective heat generating portions of an electronic assembly, and non-active areas between the active areas. A cooling fluid flows through the plenum. The plenum, at the non-active areas, has a reduced width and/or reduced height relative to the plenum at the active areas. The reduced width and/or height of the plenum, and exterior dimensions of cold plate, at the non-active areas allow the non-active areas to flex to accommodate surface variations of the electronics assembly. The reduced width and/or height non-active areas can be specifically shaped to fit between physical features of the electronics assembly.

Rutting Performance of Cold-Applied Asphalt Repair Materials for Airfield Pavements

Science.gov (United States)

2017-06-23

this study. Cold mix asphalt materials, further denoted cold mixes , were selected to reasonably represent available products on the market and were...pavement repair, primarily because of the small quantities involved and/or the unavailability of hot- mixed asphalt. These cold-applied mixtures have...poorer rutting resistance than hot mix asphalt because additives, often solvent, are required to provide adequate workability for them to be placed

Dual-Band Split-Ring Antenna Design for WLAN Applications

OpenAIRE

BAŞARAN, S. Cumhur; ERDEMLİ, Yunus E.

2014-01-01

A dual-band microstrip antenna based on split-ring elements is introduced for WLAN (2.4/5.2 GHz) applications. The proposed split-ring antenna (SRA) has a compact novel design which provides about 2% impedance-bandwidth without a need for additional matching network. Analysis and design of the proposed microstrip antenna is carried out by means of full-wave simulators based on the finite-element method.

Topological ring currents in the "empty" ring of benzo-annelated perylenes.

Science.gov (United States)

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.

The ring structure of chiral operators for minimal models coupled to 2D gravity

International Nuclear Information System (INIS)

Sarmadi, M.H.

1992-09-01

The BRST cohomology ring for (p,q) models coupled to gravity is discussed. In addition to the generators of the ghost number zero ring, the existence of a generator of ghost number - 1 and its inverse is proved and used to construct the entire ring. Some comments are made regarding the algebra of the vector fields on the ring and the supersymmetric extension. (author). 13 refs

Ripple Ring Basins on Ganymede and Callisto

Science.gov (United States)

Croft, S. K.

1985-01-01

The unusual morphology of the Valhalla multiple or ripple-ring basin in Callisto was totally unexpected in light of the morphologies of large impact structures on the terrestrial planets. Two other ripple-ring basins (RRB's), Asgard and a smaller structure near the crater Adlinda are also described. Several additional RRB's were found on Callisto, an example of which is shown. A previously unrecognized RRB on Ganymede was also found. An image and geologic sketch map of this RRB are shown. Morphometric and positional data for all known RRB's are given.

Convergent synthesis of the HIJKLM ring system of ciguatoxin CTX3C.

Science.gov (United States)

Takamura, Hiroyoshi; Nishiuma, Naoki; Abe, Takashi; Kadota, Isao

2011-09-02

The HIJKLM ring system of ciguatoxin CTX3C was synthesized in a convergent manner. The key steps were a conjugate addition/alkylation sequence, spiroacetalization, intramolecular allylation, ring-closing metathesis, and hydrogenation to form the 36-α-methyl substituent.

Kayser-Fleischer Rings

Science.gov (United States)

... 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- ...

Effect of cold work on CO sub 2 corrosion behavior of 13% Cr (420 type) stainless steel in brine medium with and without addition of sodium sulphide

International Nuclear Information System (INIS)

Akram Ali Agil; Azmi Rahmat; Suraj Bhan

1996-01-01

Cold work introduces residual stresses and increases internal stored energy. Plastic deformation also causes slip steps on the surface. All these factors effect corrosion rate as corrosion is controlled by surface reaction. The residual stresses are caused by inhomogeneous deformation in cold rolling and are maximum at low deformation and then decrease as the samples get thinner on further rolling. In the absence of CO sub 2 the corrosion rates are found relatively low in brine solution with or without addition of Na sub 2 S, with only slight variation with % total deformation. However simultaneous presence of CO sub 2 and Na sub 2 S has synergic effect increasing the corrosion rate appreciably. Presence of sulphur is also found to increase the pitting tendency in the steel

Winter-spring precipitation reconstructions from tree rings for northeast Mexico

Energy Technology Data Exchange (ETDEWEB)

Villanueva-Diaz, J.; Cerano-Paredes, J. [Instituto Nacional de Investigaciones Forestales y Agropecuarias, Centro Nacional de Investigacion Disciplinarioa en Relacion Agua, Suelo, Planta. Km 6.5 Margen Derecha del Canal Sacramento Gomez Palacio, Durango, 35140 (Mexico); Stahle, D.W.; Cleaveland, M.K. [Tree-Ring Laboratory, Department of Geosciences, University of Arkansas, fayetteville, Arkansas 72701 (United States); Luckman, B.H. [Department of Geography, University of Western Ontario, London, Ontario, N6A5C3 (Canada); Therrell, M.D. [Department of Environmental Sciences, University of Virginia, Charlottesville, VA 29904 (United States); Cornejo-Oviedo, E. [Departamento Forestal, Universidad Autonoma Agraria Antonio Narro, Saltillo, Coahuila (Mexico)

2007-07-15

The understanding of historic hydroclimatic variability is basic for planning proper management of limited water resources in northeastern Mexico. The objective of this study was to develop a network of tree-ring chronologies to reconstruct hydroclimate variability in northeastern Mexico and to analyze the influence of large-scale circulation patterns, such as ENSO. Precipitation sensitive tree-ring chronologies of Douglas-fir were developed in mountain ranges of the Sierra Madre Oriental and used to produce winter-spring precipitation reconstructions for central and southern Nuevo Leon, and southeastern Coahuila. The seasonal winter-spring precipitation reconstructions are 342 years long (1659-2001) for Saltillo, Coahuila and 602 years long (1400-2002) for central and southern Nuevo Leon. Both reconstructions show droughts in the 1810s, 1870s, 1890s, 1910s, and 1970s, and wet periods in the 1770s, 1930s, 1960s, and 1980s. Prior to 1800s the reconstructions are less similar. The impact of ENSO in northeastern Mexico (as measured by the Tropical Rainfall Index) indicated long-term instability of the Pacific equatorial teleconnection. Atmospheric circulation systems coming from higher latitudes (cold fronts or 'nortes') and others developed in the Gulf of Mexico (tropical storms, hurricanes) also influence the climatic conditions characterizing this region. The recent development of new and longer tree-ring chronologies for the region will contribute to a better understanding of the interannual and multidecadal climatic variability of northeastern Mexico.

Expert Cold Structure Development

Science.gov (United States)

Atkins, T.; Demuysere, P.

2011-05-01

The EXPERT Program is funded by ESA. The objective of the EXPERT mission is to perform a sub-orbital flight during which measurements of critical aero- thermodynamic phenomena will be obtained by using state-of-the-art instrumentation. As part of the EXPERT Flight Segment, the responsibility of the Cold Structure Development Design, Manufacturing and Validation was committed to the Belgian industrial team SONACA/SABCA. The EXPERT Cold Structure includes the Launcher Adapter, the Bottom Panel, the Upper Panel, two Cross Panels and the Parachute Bay. An additional Launcher Adapter was manufactured for the separation tests. The selected assembly definition and manufacturing technologies ( machined parts and sandwich panels) were dictated classically by the mass and stiffness, but also by the CoG location and the sensitive separation interface. Used as support for the various on-board equipment, the Cold Structure is fixed to but thermally uncoupled from the PM 1000 thermal shield. It is protect on its bottom panel by a thermal blanket. As it is a protoflight, analysis was the main tool for the verification. Low level stiffness and modal analysis tests have also been performed on the Cold Structure equipped with its ballast. It allowed to complete its qualification and to prepare SONACA/SABCA support for the system dynamic tests foreseen in 2011. The structure was finally coated with a thermal control black painting and delivered on time to Thales Alenia Space-Italy end of March 201.

Conceptualizing Cold Disasters

DEFF Research Database (Denmark)

Lauta, Kristian Cedervall; Dahlberg, Rasmus; Vendelø, Morten Thanning

2017-01-01

In the present article, we explore in more depth the particular circumstances and characteristics of governing what we call ‘cold disasters’, and thereby, the paper sets out to investigate how disasters in cold contexts distinguish themselves from other disasters, and what the implications hereof...... are for the conceptualization and governance of cold disasters. Hence, the paper can also be viewed as a response to Alexander’s (2012a) recent call for new theory in the field of disaster risk reduction. The article is structured in four overall parts. The first part, Cold Context, provides an overview of the specific...... conditions in a cold context, exemplified by the Arctic, and zooms in on Greenland to provide more specific background for the paper. The second part, Disasters in Cold Contexts, discusses “cold disasters” in relation to disaster theory, in order to, elucidate how cold disasters challenge existing...

Electrical Characteristics of the Contour-Vibration-Mode Piezoelectric Transformer with Ring/Dot Electrode Area Ratio

Science.gov (United States)

Yoo, Juhyun; Yoon, Kwanghee; Lee, Yongwoo; Suh, Sungjae; Kim, Jongsun; Yoo, Chungsik

2000-05-01

Contour-vibration-mode Pb(Sb1/2Nb1/2)O3-Pb(Zr, Ti)O3 [PSN-PZT] piezoelectric transformers with different ring/dot electrode area ratios were fabricated to the size of 27.5× 27.5× 2.5 mm3 by cold isostatic pressing. The electrical properties and characteristic temperature rises caused by the vibration were measured at various load resistances. Efficiencies above 90% with load resistance were obtained from all the transformers. The voltage step-up ratio appeared to be proportional to the dot electrode area. A 14 W fluorescent lamp, T5, was successfully driven by all of the fabricated transformers. The transformer with ring/dot electrode area ratio of 4.85 exhibited the best properties in terms of output power, efficiency and characteristic temperature rise, 14.88 W, 98% and 5°C, respectively.

Solution structure of the cold-shock-like protein from Rickettsia rickettsii

International Nuclear Information System (INIS)

Gerarden, Kyle P.; Fuchs, Andrew M.; Koch, Jonathan M.; Mueller, Melissa M.; Graupner, David R.; O’Rorke, Justin T.; Frost, Caleb D.; Heinen, Heather A.; Lackner, Emily R.; Schoeller, Scott J.; House, Paul G.; Peterson, Francis C.; Veldkamp, Christopher T.

2012-01-01

The solution structure of the cold-shock-like protein from R. rickettsii, the causative agent of Rocky Mountain spotted fever, is reported. Rocky Mountain spotted fever is caused by Rickettsia rickettsii infection. R. rickettsii can be transmitted to mammals, including humans, through the bite of an infected hard-bodied tick of the family Ixodidae. Since the R. rickettsii genome contains only one cold-shock-like protein and given the essential nature of cold-shock proteins in other bacteria, the structure of the cold-shock-like protein from R. rickettsii was investigated. With the exception of a short α-helix found between β-strands 3 and 4, the solution structure of the R. rickettsii cold-shock-like protein has the typical Greek-key five-stranded β-barrel structure found in most cold-shock domains. Additionally, the R. rickettsii cold-shock-like protein, with a ΔG of unfolding of 18.4 kJ mol −1 , has a similar stability when compared with other bacterial cold-shock proteins

Spin transport in quantum dot embedded in Aharonov-Bohm ring

International Nuclear Information System (INIS)

Wei, J.S.; Wang, R.Z.; Yuan, R.Y.; You, J.Q.; Yan, H.

2005-01-01

Spin polarized transport was studied by employing non-equilibrium Green function method, for a model of quantum dot (QD) embedded in a mesoscopic Aharonov-Bohm (AB) ring with magnetic field applied on QD. In comparison with the situation without magnetic field on QD, the average spin occupations separate with the increase in applied magnetic field on QD; in addition, magnetic field on QD has profound effect on the density of states for different spins in QD; on the other hand, the amplitude and phase of transmission for up spin and down spin were found to present novel effects, such as, the additional peak in the phase of transmission. To understand the spin transport in the system of QD coupled to AB ring, the effects of the two magnetic fields imposed on the QD and penetrating the AB ring should be considered

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

Comparing CTH simulations and experiments on explosively loaded rings

Science.gov (United States)

Braithwaite, C. H.; Aydelotte, Brady; Collins, Adam; Thadhani, Naresh; Williamson, David Martin

2012-03-01

A series of experiments were conducted on explosively loaded metallic rings for the purpose of studying fragmentation. In addition to the collection of fragments for analysis, the radial velocity of the expanding ring was measured with photon Doppler velocimetry (PDV) and the arrangement was imaged using high speed photography. Both the ring material and the material used as the explosive container were altered and the results compared with simulations performed in CTH. Good agreement was found between the simulations and the experiments. The maximum radial velocity attained was approximately 380 m/s, which was achieved through loading with a 5g PETN based charge.

ABA Is Involved in Regulation of Cold Stress Response in Bermudagrass

Directory of Open Access Journals (Sweden)

Xuebing Huang

2017-10-01

Full Text Available As a representative warm-season grass, Bermudagrass [Cynodon dactylon (L. Pers.] is widely used in turf systems. However, low temperature remarkably limits its growth and distribution. ABA is a crucial phytohormone that has been reported to regulate much important physiological and biochemical processes in plants under abiotic stress. Therefore, the objective of this study was to figure out the effects of ABA on the cold-sensitive (S and cold-resistant (R Bermudagrass genotypes response to cold stress. In this study, the plants were treated with 100 μM ABA solution and exposed to 4°C temperature. After 7 days of cold treatment, the electrolyte leakage (EL, malonaldehyde (MDA and H2O2 content were significantly increased in both genotypes compared with control condition, and these values were higher in R genotype than those of S genotype, respectively. By contrast, exogenous ABA application decreased the electrolyte leakage (EL, MDA and H2O2 content in both genotypes compared with those plants without ABA treatment under cold treatment condition. In addition, exogenous ABA application increased the levels of chlorophyll a fluorescence transient curve for both genotypes, and it was higher in R genotype than that of S genotype. Analysis of photosynthetic fluorescence parameters revealed that ABA treatment improved the performance of photosystem II under cold condition, particularly for the R genotype. Moreover, cold stress significantly increased δ13C values for both genotypes, while it was alleviated by exogenous ABA. Additionally, exogenous ABA application altered the expression of ABA- or cold related genes, including ABF1, CBF1, and LEA. In summary, exogenous ABA application enhanced cold resistance of both genotypes by maintaining cell membrane stability, improving the process of photosystem II, increasing carbon isotopic fractionation under cold stress, and more prominently in R genotype compared with S genotype.

Giant pseudoaneurysm from Vieussens' arterial ring.

Science.gov (United States)

Kocica, Mladen J; Vranes, Mile R; Djukic, Petar L; Mikic, Aleksandar Dj; Velinovic, Milos M; Havelka, Marija; Kanjuh, Vladimir I

2004-11-01

A giant coronary pseudoaneurysm of uncertain cause, arising from Vieussens' arterial ring, was preoperatively diagnosed in an oligosymptomatic female patient. Successful off-pump surgical excision without additional bypass grafting was performed. Difficulties in diagnostic algorithm, as well as possible cause and extremely rare localization were discussed.

A progress report on the g-2 storage ring magnet system

International Nuclear Information System (INIS)

Bunce, G.; Cullen, J.; Danby, G.

1995-01-01

The 3.1 GeV muon storage ring for the g-2 experiment at Brookhaven National Laboratory hat three large solenoid magnets that form a continuous 1.451 tesla storage ring dipole with an average beam bond radius of 7.1 metors. In addition to the three storage ring solenoids, there is an inflector dipole with nested dipole coils that create very little stray magnetic field. A superconducting shield on the infractor gets rid of most of the remaining stray flux. This paper reports on the progress made on the storage ring solenoid magnet system and the inflector as of June 1995. The results of cryogenic system tests are briefly reported

Cold Spray Deposition of Freestanding Inconel Samples and Comparative Analysis with Selective Laser Melting

Science.gov (United States)

Bagherifard, Sara; Roscioli, Gianluca; Zuccoli, Maria Vittoria; Hadi, Mehdi; D'Elia, Gaetano; Demir, Ali Gökhan; Previtali, Barbara; Kondás, Ján; Guagliano, Mario

2017-10-01

Cold spray offers the possibility of obtaining almost zero-porosity buildups with no theoretical limit to the thickness. Moreover, cold spray can eliminate particle melting, evaporation, crystallization, grain growth, unwanted oxidation, undesirable phases and thermally induced tensile residual stresses. Such characteristics can boost its potential to be used as an additive manufacturing technique. Indeed, deposition via cold spray is recently finding its path toward fabrication of freeform components since it can address the common challenges of powder-bed additive manufacturing techniques including major size constraints, deposition rate limitations and high process temperature. Herein, we prepared nickel-based superalloy Inconel 718 samples with cold spray technique and compared them with similar samples fabricated by selective laser melting method. The samples fabricated using both methods were characterized in terms of mechanical strength, microstructural and porosity characteristics, Vickers microhardness and residual stresses distribution. Different heat treatment cycles were applied to the cold-sprayed samples in order to enhance their mechanical characteristics. The obtained data confirm that cold spray technique can be used as a complementary additive manufacturing method for fabrication of high-quality freestanding components where higher deposition rate, larger final size and lower fabrication temperatures are desired.

Heat pumps combined with cold storage; Warmtepompen gecombineerd met koudeopslag

Energy Technology Data Exchange (ETDEWEB)

Van Ingen, M.A. [Techniplan Adviseurs, Rotterdam (Netherlands)

1999-09-01

The architects of the new Nike head office building in Hilversum, Netherlands, opted for a heat pump combined with a cold storage system. The most efficient design was found to be a single central location for the production of heat and cold, with distribution lines to each of the five buildings. The cold storage system provides direct cooling and indirect heating: the heat pump raises the low-temperature heat from the cold storage to a usable temperature (augmented by district heating when necessary). In addition, the heat pump generates cold as a by-product in winter, which can be stored in the sources system and utilised during the following summer. The heat pump can also be used for cooling, for peak load supply and for any short-term storage requirement in emergencies

Cold urticaria. Dissociation of cold-evoked histamine release and urticara following cold challenge.

Science.gov (United States)

Keahey, T M; Greaves, M W

1980-02-01

Nine patients with acquired cold urticaria were studied to assess the effects of beta-adrenergic agents, xanthines, and corticosteroids on cold-evoked histamine release from skin in vivo. The patients, in all of whom an immediate urticarial response developed after cooling of the forearm, demonstrated release of histamine into the venous blood draining that forearm. Following treatment with aminophylline and albuterol in combination or prednisone alone, suppression of histamine release occurred in all but one patient. In some patients, this was accompanied by a subjective diminution in pruritus or buring, but there was no significant improvement in the ensuing edema or erythema. In one patient, total suppression of histamine release was achieved without any effect on whealing and erythema in response to cold challenge. Our results suggest that histamine is not central to the pathogenesis of vascular changes in acquired cold urticaria.

Wavelength-selectable and steady single-mode erbium-doped fiber multiple ring laser

Science.gov (United States)

Yeh, Chien-Hung; Yang, Zi-Qing; Huang, Tzu-Jung; Chow, Chi-Wai; Chen, Jing-Heng; Chen, Kun-Huang

2017-11-01

To achieve a stable and selectable C-band erbium-doped fiber (EDF) laser with single-longitudinal-mode output, a multiple ring architecture is proposed and demonstrated experimentally. In this work, we design a passively quadruple-ring structure in the cavity of an EDF laser to produce a Vernier effect with a mode filter for suppressing the multimode spikes significantly. In addition, the output performance and stability of the proposed EDF ring laser are discussed.

Ring faults and ring dikes around the Orientale basin on the Moon.

Science.gov (United States)

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.

Superplasticity behaviors of Al-Zn-Mg-Zr cold-rolled alloy sheet with minor Sc addition

Energy Technology Data Exchange (ETDEWEB)

Xiang, H. [School of Materials Science and Engineering, Central South University (Light Alloy Research Institute, Central South University), Changsha 410083 (China); Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center, Changsha 410083 (China); Pan, Q.L., E-mail: pql2016@126.com [School of Materials Science and Engineering, Central South University (Light Alloy Research Institute, Central South University), Changsha 410083 (China); Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center, Changsha 410083 (China); Yu, X.H.; Huang, X.; Sun, X.; Wang, X.D.; Li, M.J.; Yin, Z.M. [School of Materials Science and Engineering, Central South University (Light Alloy Research Institute, Central South University), Changsha 410083 (China); Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center, Changsha 410083 (China)

2016-10-31

A refined microstructure of Al-Zn-Mg-Sc-Zr alloy sheet was produced by simple hot and cold rolling to an average grain size of 3 µm. Experiments were completed in electro-fluid servo-fatigue tester and results were investigated by means of optical microscope (OM), scanning electron microscopy (SEM) and transmission electron microscope (TEM). Superplastic deformation was conducted and superplastic ductility of ≥200% was achieved at a testing temperature range from 425 ºC to 500 ºC and relative high strain rate range of 1×10{sup −3} s{sup −1}~1×10{sup −1} s{sup −1}. The maximum elongation of 539% was obtained at 500 ºC and 1×10{sup −2} s{sup −1}. In addition, the scanning electron microscopy (SEM) and transmission electron microscope (TEM) analyses showed that the presence of Al{sub 3} (Sc, Zr) particles in pinning grain boundaries and dislocations had a great influence on the superplastic deformation. The analyses of superplastic test data calculated out the coherent strain rates sensitivity parameter of 0.43 and the average activation energy of 143.762 kJ/mol. The data interpreted that the dominant deformation mechanism was grain boundary sliding controlled by lattice self-diffusion.

De Novo Transcriptome Sequencing and the Hypothetical Cold Response Mode of Saussurea involucrata in Extreme Cold Environments.

Science.gov (United States)

Li, Jin; Liu, Hailiang; Xia, Wenwen; Mu, Jianqiang; Feng, Yujie; Liu, Ruina; Yan, Panyao; Wang, Aiying; Lin, Zhongping; Guo, Yong; Zhu, Jianbo; Chen, Xianfeng

2017-06-07

Saussurea involucrata grows in high mountain areas covered by snow throughout the year. The temperature of this habitat can change drastically in one day. To gain a better understanding of the cold response signaling pathways and molecular metabolic reactions involved in cold stress tolerance, genome-wide transcriptional analyses were performed using RNA-Seq technologies. A total of 199,758 transcripts were assembled, producing 138,540 unigenes with 46.8 Gb clean data. Overall, 184,416 (92.32%) transcripts were successfully annotated. The 365 transcription factors identified (292 unigenes) belonged to 49 transcription factor families associated with cold stress responses. A total of 343 transcripts on the signal transduction (132 upregulated and 212 downregulated in at least any one of the conditions) were strongly affected by cold temperature, such as the CBL-interacting serine/threonine-protein kinase ( CIPKs ), receptor-like protein kinases , and protein kinases . The circadian rhythm pathway was activated by cold adaptation, which was necessary to endure the severe temperature changes within a day. There were 346 differentially expressed genes (DEGs) related to transport, of which 138 were upregulated and 22 were downregulated in at least any one of the conditions. Under cold stress conditions, transcriptional regulation, molecular transport, and signal transduction were involved in the adaptation to low temperature in S. involucrata . These findings contribute to our understanding of the adaptation of plants to harsh environments and the survival traits of S. involucrata . In addition, the present study provides insight into the molecular mechanisms of chilling and freezing tolerance.

Groups, rings, modules

CERN Document Server

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

Saturn's Rings Edge-on

Science.gov (United States)

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

The Rotating Ring-Ring Electrode. Theory and Experiment

NARCIS (Netherlands)

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

Identification and expression analysis of cold and freezing stress responsive genes of Brassica oleracea.

Science.gov (United States)

Ahmed, Nasar Uddin; Jung, Hee-Jeong; Park, Jong-In; Cho, Yong-Gu; Hur, Yoonkang; Nou, Ill-Sup

2015-01-10

Cold and freezing stress is a major environmental constraint to the production of Brassica crops. Enhancement of tolerance by exploiting cold and freezing tolerance related genes offers the most efficient approach to address this problem. Cold-induced transcriptional profiling is a promising approach to the identification of potential genes related to cold and freezing stress tolerance. In this study, 99 highly expressed genes were identified from a whole genome microarray dataset of Brassica rapa. Blast search analysis of the Brassica oleracea database revealed the corresponding homologous genes. To validate their expression, pre-selected cold tolerant and susceptible cabbage lines were analyzed. Out of 99 BoCRGs, 43 were differentially expressed in response to varying degrees of cold and freezing stress in the contrasting cabbage lines. Among the differentially expressed genes, 18 were highly up-regulated in the tolerant lines, which is consistent with their microarray expression. Additionally, 12 BoCRGs were expressed differentially after cold stress treatment in two contrasting cabbage lines, and BoCRG54, 56, 59, 62, 70, 72 and 99 were predicted to be involved in cold regulatory pathways. Taken together, the cold-responsive genes identified in this study provide additional direction for elucidating the regulatory network of low temperature stress tolerance and developing cold and freezing stress resistant Brassica crops. Copyright © 2014 Elsevier B.V. All rights reserved.

Black rings and the physical process version of the first law of thermodynamics

International Nuclear Information System (INIS)

Rogatko, Marek

2005-01-01

We consider the problem of the physical process version of the first law of black ring thermodynamics in n-dimensional Einstein gravity with additional (p+1)-form field strength and dilaton fields. The first order variations of mass, angular momentum and local charge for black ring are derived. From them we prove the physical process version of the first law of thermodynamic for stationary black rings

Synthesis of azaphenanthridines via anionic ring closure

DEFF Research Database (Denmark)

Hansen, Henriette Møller; Lysén, M.; Begtrup, M.

2005-01-01

A new and convergent synthesis of azaphenanthridines via an anionic ring closure is reported. Ortho-lithiation/in situ borylation of cyanopyridines produces the corresponding cyanopyridylboronic esters, which undergo a Suzuki-Miyaura cross-coupling to give the key intermediates. Addition of lithium...

Internal stress distribution of X-ring using photoelastic experimental hybrid method

Energy Technology Data Exchange (ETDEWEB)

Bernard, Alunda Ouma [Dedan Kimathi University of Technology, Nyeri (Kenya); Hawong, Jai Sug; Lim, Hyun Seok [Yeungnam University, Gyeongsan (Korea, Republic of); Shin, Dong Chul [Koje College, Geoje (Korea, Republic of)

2014-05-15

Sealing elements are essential parts of many machines, and are used to prevent the loss of a fluid or gas. When such fluids are not properly sealed, catastrophic failures may result. Many different types of rings have been developed to suit various industrial needs. Considerable research has been done on the O-ring. We analyze the internal stresses developed in an X-ring under a uniform squeeze rate of 20%, which is suitable for static applications, using a photoelastic experimental hybrid method. The internal pressures applied were 0.98, 1.96, 2.94, 3.92, 4.90, and 5.88 MPa. We show that sealing rings with X geometry have considerably higher internal stresses than O-ring seals. In addition, we demonstrate that after extrusion, for an internal pressure of 5.88 MPa, the two lobes on the upper contact surface merge, thereby increasing the contact length of the upper side significantly. Extrusion in the X-ring occurred when the internal pressure was 4.90 MPa.

Relationships of self-identified cold tolerance and cold-induced vasodilatation in the finger

Science.gov (United States)

Park, Joonhee; Lee, Joo-Young

2016-04-01

This study was conducted to investigate relationships of self-identified cold tolerance and cold-induced vasodilatation (CIVD) in the finger. Nine males and 34 females participated in the following 2 tests: a CIVD test and a self-reported survey. The CIVD test was conducted 30-min cold-water immersion (3.8 ± 0.3 °C) of the middle finger at an air temperature of 27.9 ± 0.1 °C. The self-reported questionnaire consisted of 28 questions about whole and local body cold and heat tolerances. By a cluster analysis on the survey results, the participants were divided into two groups: high self-identified cold tolerance (HSCT, n = 25) and low self-identified cold tolerance (LSCT, n = 18). LSCT had lower self-identified cold tolerance ( P cold or heat tolerance had relationships with cold tolerance index, T max, and amplitude ( P cold tolerance classified through a standardized survey could be a good index to predict physiological cold tolerance.

PREFACE: Special section on vortex rings Special section on vortex rings

Science.gov (United States)

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

Calculations of toroidal EXTRAP equilibria for different toroidal ring current configurations

International Nuclear Information System (INIS)

Drake, J.R.; Scheffel, J.

1985-12-01

EXTRAP is a concept in which a pure Z-pinch is generated along the axis of an octupole field. Experiments in a linear as well as in a sector geometry have demonstrated that the pinch becomes stable against instabilities for many Alfven times. The octupole field in EXTRAP is produced by four, external, current-carrying rings. In the toroidal geometry these rings must be supplemented by additional rings to compensate for the plasma loop force and transformer core leakage flux. Equilibrium studies are carried out for two basically ring designs. The studies are based on numerical equilibrium copmputations using the GOYA code. Sensitivity of the equilibrium to technical imperfections is also analyzed. (author)

Some commutativity theorems for a certain class of rings

International Nuclear Information System (INIS)

Khan, M.A.

1994-08-01

In the present paper we first establish the commutativity theorem for semiprime ring satisfying the polynomial identity [x n ,y]x r = ±y s [x,y m ]y t for all x,y in R, where m,n,r,s and t are fixed nonnegative integers, and further, we investigate commutativity of rings with unity under some additional hypothesis. Moreover, it is also shown that the above result is true for s-unital. Also, we provide some counter examples which show that the hypothesis of our theorems are not altogether superfluous. The results of this paper generalize some of the well-known commutativity theorems for rings which are right s-unital. (author). 21 refs

Velocity space ring-plasma instability, magnetized, Part I: Theory

International Nuclear Information System (INIS)

Lee, J.K.; Birdsall, C.K.

1979-01-01

The interaction of magnetized monoenergetic ions (a ring in velocity space) with a homogeneous Maxwellian target plasma is studied numerically using linear Vlasov theory. The ring may be produced when an energetic beam is injected perpendicular to a uniform magnetic field. In addition to yielding the previously known results, the present study classifies this flute-like instability into three distinct regimes based on the beam density relative to the plasma density, where many features such as physical mechanisms, dispersion diagrams, and maximum growth rates are quite different. The effects of electron dynamics, plasma or ring thermal spread, the ratio of ω/sub p//ω/sub c/ for plasma ions, and electromagnetic modifications are also considered

Vortex rings

CERN Document Server

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.

BEAM TRANSPORT AND STORAGE WITH COLD NEUTRAL ATOMS AND MOLECULES

Energy Technology Data Exchange (ETDEWEB)

Walstrom, Peter L. [Los Alamos National Laboratory

2012-05-15

A large class of cold neutral atoms and molecules is subject to magnetic field-gradient forces. In the presence of a field, hyperfine atomic states are split into several Zeeman levels. The slopes of these curves vs. field are the effective magnetic moments. By means of optical pumping in a field, Zeeman states of neutral lithium atoms and CaH molecules with effective magnetic moments of nearly {+-} one Bohr magneton can be selected. Particles in Zeeman states for which the energy increases with field are repelled by increasing fields; particles in states for which the energy decreases with field are attracted to increasing fields. For stable magnetic confinement, field-repelled states are required. Neutral-particle velocities in the present study are on the order of tens to hundreds of m/s and the magnetic fields needed for transport and injection are on the order of in the range of 0.01-1T. Many of the general concepts of charged-particle beam transport carry over into neutral particle spin-force optics, but with important differences. In general, the role of bending dipoles in charged particle optics is played by quadrupoles in neutral particle optics; the role of quadrupoles is played by sextupoles. The neutralparticle analog of charge-exchange injection into storage rings is the use of lasers to flip the state of particles from field-seeking to field-repelled. Preliminary tracking results for two neutral atom/molecule storage ring configurations are presented. It was found that orbit instabilities limit the confinment time in a racetrack-shaped ring with discrete magnetic elements with drift spaces between them; stable behavior was observed in a toroidal ring with a continuous sextupole field. An alternative concept using a linear sextupole or octupole channel with solenoids on the ends is presently being considered.

A Compact, High-Flux Cold Atom Beam Source

Science.gov (United States)

Kellogg, James R.; Kohel, James M.; Thompson, Robert J.; Aveline, David C.; Yu, Nan; Schlippert, Dennis

2012-01-01

The performance of cold atom experiments relying on three-dimensional magneto-optical trap techniques can be greatly enhanced by employing a highflux cold atom beam to obtain high atom loading rates while maintaining low background pressures in the UHV MOT (ultra-high vacuum magneto-optical trap) regions. Several techniques exist for generating slow beams of cold atoms. However, one of the technically simplest approaches is a two-dimensional (2D) MOT. Such an atom source typically employs at least two orthogonal trapping beams, plus an additional longitudinal "push" beam to yield maximum atomic flux. A 2D atom source was created with angled trapping collimators that not only traps atoms in two orthogonal directions, but also provides a longitudinal pushing component that eliminates the need for an additional push beam. This development reduces the overall package size, which in turn, makes the 2D trap simpler, and requires less total optical power. The atom source is more compact than a previously published effort, and has greater than an order of magnitude improved loading performance.

The role of cold plasma and its composition on the growth of electromagnetic ion cyclotron waves in the inner magnetosphere

Science.gov (United States)

Snelling, J. M.; Johnson, J.; Engebretson, M. J.; Kim, E. H.; Tian, S.

2017-12-01

While it is currently well accepted that the free energy for growth of electromagnetic ion cyclotron (EMIC) waves in Earth's magnetosphere comes from unstable configurations of hot anisotropic ions that are injected into the ring current, several questions remain about what controls the instability. A recent study of the occurrence of EMIC waves relative to the plasmapause in Vallen Probes Data showed that plasma density gradients or enhancements were not the dominant factor in determining the site of EMIC wave generation [Tetrick et al. 2017]. However, the factors that control wave growth on each of the branches are not fully understood. For example, in some cases, the measured anisotropy is not adequate to explain local instability, and the relative importance of the density and composition of a cold plasma population is still uncertain. Several intervals of EMIC wave activity are analyzed to determine the role of a cold population in driving instability on each of the wave branches. This study utilizes the WHAMP (Waves in Homogeneous Anisotropic Magnetized Plasma) stability code with plasma distributions optimized to fit the observed distributions including temperature anisotropy, loss cone, and ring beam populations.

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

Burning Cold: Involvement of TRPA1 in Noxious Cold Sensation

OpenAIRE

Kwan, Kelvin Y.; Corey, David P.

2009-01-01

Soon after its discovery ten years ago, the ion channel TRPA1 was proposed as a sensor of noxious cold. Evidence for its activation by painfully cold temperatures (below ~15° C) has been mixed, however. Some groups found that cold elicits a nonselective conductance in cells expressing TRPA1; others found no activation, or argued that activation is an indirect effect of elevated \\(Ca^{ 2+}\\) . Sensory cells from the trigeminal and dorsal root ganglia that are activated by cold were sometimes c...

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)

High Time Resolution Measurements of VOCs from Vehicle Cold Starts: The Air Toxic Cold Start Pulse

Science.gov (United States)

Jobson, B. T.; Huangfu, Y.; Vanderschelden, G. S.

2017-12-01

Pollutants emitted during motor vehicle cold starts, especially in winter in some climates, is a significant source of winter time air pollution. While data exist for CO, NO, and total hydrocarbon emissions from federal testing procedures for vehicle emission certification, little is known about the emission rates of individual volatile organic compounds, in particular the air toxics benzene, formaldehyde, and acetaldehyde. Little is known about the VOC speciation and temperature dependence for cold starts. The US EPA vehicle emission model MOVES assumes that cold start emissions have the same speciation profile as running emissions. We examined this assumption by measuring cold start exhaust composition for 4 vehicles fueled with E10 gasoline over a temperature range of -4°C to 10°C in winter of 2015. The extra cold start emissions were determined by comparison with emissions during engine idling. In addition to CO and NOx measurements a proton transfer reaction mass spectrometer was used to measure formaldehyde, acetaldehyde, benzene, toluene, and C2-alkylbenzenes at high time resolution to compare with the cold start emission speciation profiles used in the EPA MOVES2014 model. The results show that after the vehicle was started, CO mixing ratios can reach a few percent of the exhaust and then drop to several ppmv within 2 minutes of idling, while NOx showed different temporal behaviors among the four vehicles. VOCs displayed elevated levels during cold start and the peak mixing ratios can be two orders higher than idling phase levels. Molar emission ratios relative to toluene were used to compare with the emission ratio used in MOVES2014 and we found the formaldehyde-to-toluene emission ratio was about 0.19, which is 5 times higher than the emission ratio used in MOVES2014 and the acetaldehyde-to-toluene emission ratios were 0.86-0.89, which is 8 times higher than the ones in MOVES2014. The C2-alkylbenzene-to-toluene ratio agreed well with moves. Our results

Cold-Hearted or Cool-Headed: Physical Coldness Promotes Utilitarian Moral Judgment

Directory of Open Access Journals (Sweden)

Hiroko eNakamura

2014-10-01

Full Text Available In the current study, we examine the effect of physical coldness on personal moral dilemma judgment. Previous studies have indicated that utilitarian moral judgment—sacrificing a few people to achieve the greater good for others—was facilitated when: (1 participants suppressed an initial emotional response and deliberately thought about the utility of outcomes; (2 participants had a high-level construal mindset and focused on abstract goals (e.g., save many; or (3 there was a decreasing emotional response to sacrificing a few. In two experiments, we exposed participants to extreme cold or typical room temperature and then asked them to make personal moral dilemma judgments. The results of Experiment 1 indicated that coldness prompted utilitarian judgment, but the effect of coldness was independent from deliberate thought or abstract high-level construal mindset. As Experiment 2 revealed, coldness facilitated utilitarian judgment via reduced empathic feelings. Therefore, physical coldness did not affect the cool-headed deliberate process or the abstract high-level construal mindset. Rather, coldness biased people toward being cold-hearted, reduced empathetic concern about a sacrificed victim, and facilitated utilitarian moral judgments.

Aspects of cold intrusions over Greece during autumn

Science.gov (United States)

Mita, Constantina; Marinaki, Aggeliki; Zeini, Konstantina; Konstantara, Metaxia

2010-05-01

This study is focused on the description of atmospheric disturbances that caused intense cold intrusions over Greece during autumn for a period of 25 years (1982-2006). The study was based on data analysis from the meteorological station network of the Hellenic National Meteorological Service (HNMS) and the European Centre for Medium Range Weather Forecasts (ECMWF). Initially, the days with temperature at the isobaric surface of 850 hPa less or equal to the mean temperature for the 10-day period the day under investigation belongs to are isolated, composing a new confined data set which was further used. An event of intense cold intrusion is identified based on a subjective set of criteria, considering the temperature decrease at the level of 850 hPa and its duration. In particular, the criteria that were used to identify a cold intrusion were: temperature variation between two successive days at the isobaric level of 850 hPa being equal or greater than 50 C at least once during the event and duration of the event of at least two successive days with continuous temperature decrease. Additionally, the synoptic analysis of the atmospheric disturbances involved using weather charts from ECMWF, revealed that all cases were related to low pressure systems at the level of 500 hPa, accompanied by cold air masses. Moreover, a methodology proposed to classify the cold intrusions based on general circulation characteristics of the atmosphere, resulted in seven major categories. More than half of the events belong in two categories, originated northwest of the greater Greek area (Greece and parts of neighbouring countries), between 400 and 600 N. Further analysis indicated that the frequency of events increases from September to November and the majority of the events lasted two to three days. Additionally, the non-parametric Mann-Kendall test was used for the investigation of the statistical significance of the trends appearing in the results. The tests revealed that over

Physics with colder molecular ions: The Heidelberg Cryogenic Storage Ring CSR

International Nuclear Information System (INIS)

Zajfman, D; Wolf, A; Schwalm, D; Orlov, D A; Grieser, M; Hahn, R von; Welsch, C P; Lopez-Urrutia, J R Crespo; Schroeter, C D; Urbain, X; Ullrich, J

2005-01-01

A novel cryogenic electrostatic storage ring is planned to be built at the Max-Planck Institute for Nuclear Physics in Heidelberg. The machine is expected to operate at low temperatures (∼2K) and to store beams with kinetic energies between 20 to 300 keV. An electron target based on cooled photocathode technology will serve as a major tool for the study of reactions between molecular ions and electrons. Moreover, atomic beams can be merged and crossed with the stored ion beams allowing for atom molecular-ion collision studies at very low up to high relative energies. The proposed experimental program, centered around the physics of cold molecular ions, is shortly outlined

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.

Stirling engine piston ring

Science.gov (United States)

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.

Physics of quantum rings

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.

How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?

Science.gov (United States)

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.

α-Skew π-McCoy Rings

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.

Ionic mechanisms of spinal neuronal cold hypersensitivity in ciguatera.

Science.gov (United States)

Patel, Ryan; Brice, Nicola L; Lewis, Richard J; Dickenson, Anthony H

2015-12-01

Cold hypersensitivity is evident in a range of neuropathies and can evoke sensations of paradoxical burning cold pain. Ciguatoxin poisoning is known to induce a pain syndrome caused by consumption of contaminated tropical fish that can persist for months and include pruritus and cold allodynia; at present no suitable treatment is available. This study examined, for the first time, the neural substrates and molecular components of Pacific ciguatoxin-2-induced cold hypersensitivity. Electrophysiological recordings of dorsal horn lamina V/VI wide dynamic range neurones were made in non-sentient rats. Subcutaneous injection of 10 nm ciguatoxin-2 into the receptive field increased neuronal responses to innocuous and noxious cooling. In addition, neuronal responses to low-threshold but not noxious punctate mechanical stimuli were also elevated. The resultant cold hypersensitivity was not reversed by 6-({2-[2-fluoro-6-(trifluoromethyl)phenoxy]-2-methylpropyl}carbamoyl)pyridine-3-carboxylic acid, an antagonist of transient receptor potential melastatin 8 (TRPM8). Both mechanical and cold hypersensitivity were completely prevented by co-injection with the Nav 1.8 antagonist A803467, whereas the transient receptor potential ankyrin 1 (TRPA1) antagonist A967079 only prevented hypersensitivity to innocuous cooling and partially prevented hypersensitivity to noxious cooling. In naive rats, neither innocuous nor noxious cold-evoked neuronal responses were inhibited by antagonists of Nav 1.8, TRPA1 or TRPM8 alone. Ciguatoxins may confer cold sensitivity to a subpopulation of cold-insensitive Nav 1.8/TRPA1-positive primary afferents, which could underlie the cold allodynia reported in ciguatera. These data expand the understanding of central spinal cold sensitivity under normal conditions and the role of these ion channels in this translational rat model of ciguatoxin-induced hypersensitivity. © 2015 The Authors. European Journal of Neuroscience published by Federation of

Cold dark matter plus not-so-clumpy dark relics

International Nuclear Information System (INIS)

Diamanti, Roberta; Ando, Shin'ichiro; Weniger, Christoph; Gariazzo, Stefano; Mena, Olga

2017-01-01

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f ncdm of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2σ limits for non-cold dark matter particles with masses in the range 1–10 keV are f ncdm ≤0.29 (0.23) for fermions (bosons), and for masses in the 10–100 keV range they are f ncdm ≤0.43 (0.45), respectively.

Cold dark matter plus not-so-clumpy dark relics

Energy Technology Data Exchange (ETDEWEB)

Diamanti, Roberta; Ando, Shin' ichiro; Weniger, Christoph [GRAPPA, Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Gariazzo, Stefano; Mena, Olga, E-mail: r.diamanti@uva.nl, E-mail: s.ando@uva.nl, E-mail: gariazzo@to.infn.it, E-mail: omena@ific.uv.es, E-mail: c.weniger@uva.nl [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de Valencia, Apartado de Correos 22085, E-46071, Valencia (Spain)

2017-06-01

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark matter scenarios, where the first component is assumed to be cold, and the second is a non-cold thermal relic. Considering the cases where the non-cold dark matter species could be either a fermion or a boson, we derive consistent upper limits on the non-cold dark relic energy density for a very large range of velocity dispersions, covering the entire range from dark radiation to cold dark matter. To this end, we employ the latest Planck Cosmic Microwave Background data, the recent BOSS DR11 and other Baryon Acoustic Oscillation measurements, and also constraints on the number of Milky Way satellites, the latter of which provides a measure of the suppression of the matter power spectrum at the smallest scales due to the free-streaming of the non-cold dark matter component. We present the results on the fraction f {sub ncdm} of non-cold dark matter with respect to the total dark matter for different ranges of the non-cold dark matter masses. We find that the 2σ limits for non-cold dark matter particles with masses in the range 1–10 keV are f {sub ncdm}≤0.29 (0.23) for fermions (bosons), and for masses in the 10–100 keV range they are f {sub ncdm}≤0.43 (0.45), respectively.

Assembly of the MreB-associated cytoskeletal ring of Escherichia coli.

Science.gov (United States)

Vats, Purva; Shih, Yu-Ling; Rothfield, Lawrence

2009-04-01

The Escherichia coli actin homologue MreB is part of a helical cytoskeletal structure that winds around the cell between the two poles. It has been shown that MreB redistributes during the cell cycle to form circumferential ring structures that flank the cytokinetic FtsZ ring and appear to be associated with division and segregation of the helical cytoskeleton. We show here that the MreB cytoskeletal ring also contains the MreC, MreD, Pbp2 and RodA proteins. Assembly of MreB, MreC, MreD and Pbp2 into the ring structure required the FtsZ ring but no other known components of the cell division machinery, whereas assembly of RodA into the cytoskeletal ring required one or more additional septasomal components. Strikingly, MreB, MreC, MreD and RodA were each able to independently assemble into the cytoskeletal ring and coiled cytoskeletal structures in the absence of any of the other ring components. This excludes the possibility that one or more of these proteins acts as a scaffold for incorporation of the other proteins into these structures. In contrast, incorporation of Pbp2 required the presence of MreC, which may provide a docking site for Pbp2 entry.

Stress analysis of HLW containers. Preliminary ring test exercise Compas project

International Nuclear Information System (INIS)

1989-01-01

This document describes the series of experiments and associated calculations performed as the Compas preliminary ring test exercise. A number of mild steel rings, representative of sections through HLW containers, some notched and pre-cracked, were tested in compression right up to and beyond their ultimate load. The Compas project partners independently modelled the behaviour of these rings using their finite element codes. Four different ring types were tested, and each test was repeated three times. For three of the ring types, the three test repetitions gave identical results. The fourth ring, which was not modelled by the partners, had a 4 mm thick layer of weld metal deposited on its surface. The three tests on this ring did not give identical results and suggested that the effect of welding methods should be addressed at a later stage of the project. Fracture was not found to be a significant cause of ring failure. The results of the ring tests were compared with the partners predictions, and additionally some time was spent assessing where the use of the codes could be improved. This exercise showed that the partners codes have the ability to produce results within acceptable limits. Most codes were unable to model stable crack growth. There were indications that some codes would not be able to cope with a significantly more complex three-dimensional analysis

In vitro contraction of cytokinetic ring depends on myosin II but not on actin dynamics.

Science.gov (United States)

Mishra, Mithilesh; Kashiwazaki, Jun; Takagi, Tomoko; Srinivasan, Ramanujam; Huang, Yinyi; Balasubramanian, Mohan K; Mabuchi, Issei

2013-07-01

Cytokinesis in many eukaryotes involves the contraction of an actomyosin-based contractile ring. However, the detailed mechanism of contractile ring contraction is not fully understood. Here, we establish an experimental system to study contraction of the ring to completion in vitro. We show that the contractile ring of permeabilized fission yeast cells undergoes rapid contraction in an ATP- and myosin-II-dependent manner in the absence of other cytoplasmic constituents. Surprisingly, neither actin polymerization nor its disassembly is required for contraction of the contractile ring, although addition of exogenous actin-crosslinking proteins blocks ring contraction. Using contractile rings generated from fission yeast cytokinesis mutants, we show that not all proteins required for assembly of the ring are required for its contraction in vitro. Our work provides the beginnings of the definition of a minimal contraction-competent cytokinetic ring apparatus.

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.

TSR: A storage and cooling ring for HIE-ISOLDE

Energy Technology Data Exchange (ETDEWEB)

Butler, P.A. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Blaum, K. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Davinson, T. [School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Flanagan, K.; Freeman, S.J. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Grieser, M. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Lazarus, I.H. [S.T.F.C. Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Litvinov, Yu.A. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Lotay, G. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Page, R.D. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Raabe, R. [KU Leuven, Instituut voor Kern- en Stralingsfysica, 3001 Leuven (Belgium); Siesling, E.; Wenander, F. [CERN, 1211 Geneva 23 (Switzerland); Woods, P.J. [School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom)

2016-06-01

It is planned to install the heavy-ion, low-energy ring TSR, currently at the Max-Planck-Institute for Nuclear Physics in Heidelberg, at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored, cooled secondary beams that is rich and varied, spanning from studies of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. In addition to experiments performed using beams recirculating within the ring, the cooled beams can be extracted and exploited by external spectrometers for high-precision measurements. The capabilities of the ring facility as well as some physics cases will be presented, together with a brief report on the status of the project.

Interaction Region Design for a Ring-Ring LHeC

CERN Document Server

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...

Grooved cold moderator tests

International Nuclear Information System (INIS)

Inoue, K.; Kiyanagi, Y.; Iwasa, H.; Watanabe, N.; Ikeda, S.; Carpenter, J.M.; Ishikawa, Y.

1983-01-01

We performed some grooved cold moderator experiments for methane at 20 K by using the Hokkaido University linac to obtain information to be used in the planning of the KENS-I' project. Cold neutron gains, spatial distribution of emitted beams and time distribution of the neutrons in the grooved cold moderator were measured. Furthermore, we assessed the effects of the grooved cold moderator on the performances of the spectrometers presently installed at the KENS-I cold source. We concluded that the grooved cold moderator benefited appreciably the performances of the spectrometers

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.

Influence of ring growth rate on damage development in hot ring rolling

NARCIS (Netherlands)

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

Cold and hot model investigation of flow and mixing in a multi-jet flare

Energy Technology Data Exchange (ETDEWEB)

Pagot, P.R. [Petrobras Petroleo Brasileiro S.A., Rio de Janeiro (Brazil); Sobiesiak, A. [Windsor Univ., ON (Canada); Grandmaison, E.W. [Queen' s Univ., Kingston, ON (Canada). Centre for Advanced Gas Combustion Technology

2003-07-01

The oil and gas industry commonly disposes of hydrocarbon wastes by flaring. This study simulated several features of industrial offshore flares in a multi-jet burner. Cold and hot flow experiments were performed. Twenty-four nozzles mounted on radial arms originating from a central fuel plenum were used in the burner design. In an effort to improve the mixing and radiation characteristics of this type of burner, an examination of the effect of various mixing-altering devices on the nozzle exit ports was performed. Flow visualization studies of the cold and hot flow systems were presented, along with details concerning temperature, gas composition and radiation levels from the burner models. The complex flow pattern resulting when multiple jets are injected into a cross flow stream were demonstrated with the flow visualization studies from the cold model. The trajectory followed by the leading edge jet for the reference case and the ring attachments was higher but similar to the simple round jet in a cross flow. The precessing jets and the cone attachments were more strongly deflected by the cross flow with a higher degree of mixing between the jets in the nozzle region. For different firing rates, flow visualization, gas temperature, gas composition and radiative heat flux measurements were performed in the hot model studies. Flame trajectories, projected side view areas and volumes increased with firing rates for all nozzle configurations and the ring attachment flare had the smallest flame volume. The gas temperatures reached maximum values at close to 30 per cent of the flame length and the lowest gas temperature was observed for the flare model with precessing jets. For the reference case nozzle, nitrogen oxide (NOx) concentrations were in the 30 to 45 parts per million (ppm) range. The precessing jet model yielded NOx concentrations in the 22 to 24 ppm range, the lowest obtained. There was a linear dependence between the radiative heat flux from the flames

Ring rotational speed trend analysis by FEM approach in a Ring Rolling process

Science.gov (United States)

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.

Three-dimensional ordering of cold ion beams in a storage ring: A molecular-dynamics simulation study

Energy Technology Data Exchange (ETDEWEB)

Yuri, Yosuke, E-mail: yuri.yosuke@jaea.go.jp [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki-machi Takasaki, Gunma 370-1292 Japan (Japan)

2015-06-29

Three-dimensional (3D) ordering of a charged-particle beams circulating in a storage ring is systematically studied with a molecular-dynamics simulation code. An ion beam can exhibit a 3D ordered configuration at ultralow temperature as a result of powerful 3D laser cooling. Various unique characteristics of the ordered beams, different from those of crystalline beams, are revealed in detail, such as the single-particle motion in the transverse and longitudinal directions, and the dependence of the tune depression and the Coulomb coupling constant on the operating points.

An improved ring removal procedure for in-line x-ray phase contrast tomography

Science.gov (United States)

Massimi, Lorenzo; Brun, Francesco; Fratini, Michela; Bukreeva, Inna; Cedola, Alessia

2018-02-01

The suppression of ring artifacts in x-ray computed tomography (CT) is a required step in practical applications; it can be addressed by introducing refined digital low pass filters within the reconstruction process. However, these filters may introduce additional ringing artifacts when simultaneously imaging pure phase objects and elements having a non-negligible absorption coefficient. Ringing originates at sharp interfaces, due to the truncation of spatial high frequencies, and severely affects qualitative and quantitative analysis of the reconstructed slices. In this work, we discuss the causes of ringing artifacts, and present a general compensation procedure to account for it. The proposed procedure has been tested with CT datasets of the mouse central nervous system acquired at different synchrotron radiation facilities. The results demonstrate that the proposed method compensates for ringing artifacts induced by low pass ring removal filters. The effectiveness of the ring suppression filters is not altered; the proposed method can thus be considered as a framework to improve the ring removal step, regardless of the specific filter adopted or the imaged sample.

Ring correlations in random networks.

Science.gov (United States)

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.

Instrumental neutron activation analysis of tree rings for dendrochemical studies

International Nuclear Information System (INIS)

Schaumloffel, J.C.; Filby, R.H.

1996-01-01

Instrumental neutron activation analysis (INAA) was employed to determine zinc, cadmium and potassium concentrations in the growth rings of ponderosa pine (Pinus ponderosa Dougl.) trees growing along the shores of Lake Roosevelt in Washington State, U.S.A. where mineral processing activities have resulted in high burdens of zinc and cadmium in the lake sediments. The tree growing along the contaminated waterway display elevated concentrations of zinc in its growth rings relative to a tree growing along an uncontaminated tributary of Lake Roosevelt. Cadmium concentrations in the growth rings from both sites are similar from 1988 to 1993. Water quality data indicate an increased concentration of cadmium in the lake from 1984 to 1988. The increased concentrations of cadmium in the lake water were reflected in apparent increases in concentrations of cadmium in individual rings of the tree sampled at the contaminated site. This suggests that translocation of cadmium in the sapwood of heartwood-forming species does not occur in the short term, and thus may not be a limiting factor in using trees as environmental monitors for cadmium. In addition, five-year tree ring segments were analyzed and subsequently reanalyzed as individual single-year ring segments. The analytical data obtained for the pooled individual rings are essentially the same as for the five-year segments, demonstrating the utility of NAA for dendrochemical studies. (author). 24 refs., 5 figs., 2 tabs

Limits to the observation of coherent oscillations in a SQUID ring

International Nuclear Information System (INIS)

Diggins, J.

1995-01-01

Using the quantum mechanical, lumped component model of a SQUID ring we compute the onset of tunnelling and macroscopic superposition behaviour in the parameter space of the ring. In addition, we make a quantitative estimate of the stability required in the environmental flux to sustain a superposition state. Both these features are of crucial importance to the realisation of experiments aimed at revealing such behaviour. (orig.)

Cold acclimation increases cold tolerance independently of diapause programing in the bean bug, Riptortus pedestris.

Science.gov (United States)

Rozsypal, J; Moos, M; Goto, S G

2017-10-17

The bean bug (Riptortus pedestris) is a pest of soybeans and other legumes in Japan and other Asian countries. It enters a facultative adult diapause on exposure to short days. While photoperiodism and diapause are well understood in R. pedestris, knowledge of cold tolerance is very limited, as is information on the effect of diapause on cold tolerance. We examined the effect of photoperiod, cold acclimation, and feeding status on cold tolerance in R. pedestris. We found that cold acclimation significantly increased survival at -10°C in both long- and short-day adult R. pedestris. Since the difference in cold survival between long- and short-day cold-acclimated groups was only marginal, we conclude that entering diapause is not crucial for R. pedestris to successfully pass through cold acclimation and become cold tolerant. We observed similar effects in 5th instar nymphs, with both long- and short-day cold-acclimated groups surviving longer cold exposures compared with non-acclimated groups. Starvation, which was tested only in adult bugs, had only a negligible and negative impact on cold survival. Although cold tolerance significantly increased with cold acclimation in adult bugs, supercooling capacity unexpectedly decreased. Our results suggest that changes in supercooling capacity as well as in water content are unrelated to cold tolerance in R. pedestris. An analysis of metabolites revealed differences between the treatments, and while several metabolites markedly increased with cold acclimation, their concentrations were too low to have a significant effect on cold tolerance.

Modeling and Design Guidelines for P⁺ Guard Rings in Lightly Doped CMOS Substrates

DEFF Research Database (Denmark)

Shen, Ming; Mikkelsen, Jan H.; Zhang, Ke

2013-01-01

of ${rm P}^{+}$ guard rings in terms of S-parameters, which is useful for substrate noise mitigation in mixed-signal system-on-chips. Validation of the model has been done by both electromagnetic simulation and experimental results from guard rings implemented using a standard 0.18-$mu{rm m}$ CMOS process....... In addition, design guidelines have been drawn for minimizing the guard ring size while maintaining the noise suppression performance....

Spin temperature and density of cold and warm H I in the Galactic disk: Hidden H I

Science.gov (United States)

Sofue, Yoshiaki

2018-05-01

We present a method to determine the spin temperature TS and volume density n of H I gas simultaneously along the tangent-point circle of Galactic rotation in the Milky Way by using the χ2 method. The best-fit TS is shown to range either in TS ˜ 100-120 K or in 1000-3000 K, indicating that the gas is in the cold H I phase with high density and large optical depth, or in warm H I with low density and small optical depth. Averaged values at 3 ≤ R ≤ 8 kpc are obtained to be TS = 106.7 ± 16.0 K and n = 1.53 ± 0.86 H cm-3 for cold H I, and 1720 ± 1060 K and 0.38 ± 0.10 H cm-3 for warm H I, where R = 8 |sinl| kpc is the galacto-centric distance along the tangent-point circle. The cold H I appears in spiral arms and rings, whereas warm H I appears in the inter-arm regions. The cold H I is denser by a factor of ˜4 than warm H I. The present analysis has revealed the hidden H I mass in the cold and optically thick phase in the Galactic disk. The total H I mass inside the solar circle is shown to be greater by a factor of 2-2.5 than the current estimation by the optically thin assumption.

Perspective Research Progress in Cold Responses of Capsella bursa-pastoris

Directory of Open Access Journals (Sweden)

Ali Noman

2017-08-01

Full Text Available Plants respond to cold stress by modulating biochemical pathways and array of molecular events. Plant morphology is also affected by the onset of cold conditions culminating at repression in growth as well as yield reduction. As a preventive measure, cascades of complex signal transduction pathways are employed that permit plants to endure freezing or chilling periods. The signaling pathways and related events are regulated by the plant hormonal activity. Recent investigations have provided a prospective understanding about plant response to cold stress by means of developmental pathways e.g., moderate growth involved in cold tolerance. Cold acclimation assays and bioinformatics analyses have revealed the role of potential transcription factors and expression of genes like CBF, COR in response to low temperature stress. Capsella bursa-pastoris is a considerable model plant system for evolutionary and developmental studies. On different occasions it has been proved that C. bursa-pastoris is more capable of tolerating cold than A. thaliana. But, the mechanism for enhanced low or freezing temperature tolerance is still not clear and demands intensive research. Additionally, identification and validation of cold responsive genes in this candidate plant species is imperative for plant stress physiology and molecular breeding studies to improve cold tolerance in crops. We have analyzed the role of different genes and hormones in regulating plant cold resistance with special reference to C. bursa-pastoris. Review of collected data displays potential ability of Capsella as model plant for improvement in cold stress regulation. Information is summarized on cold stress signaling by hormonal control which highlights the substantial achievements and designate gaps that still happen in our understanding.

Assessing the thermal performance of three cold energy storage materials with low eutectic temperature for food cold chain

International Nuclear Information System (INIS)

Li, Yu-Chu M.; Chen, Yen-Hong A.

2016-01-01

Development a novel inorganic salt eutectic solution for cold energy storage material (ESM) have succeeded conducted in this study. The eutectic solutions shows a low melting temperature and high latent heat of fusion value as effect of addition nano copper powder into the eutectic solution. We report a new simulation technique of thermal property as well as test results of three inorganic salts. The thermal property of three inorganic salts were simulated using the differential scanning calorimetry (DSC) method with the help of three binary phase diagrams. The simulation shows the liquidus temperature of each binary phase diagram conforming nicely to the theoretical prediction of the Gibbs-Duhem equation. In order to predict cold storage keeping time, we derived a heat transfer model based on energy conservation law. Three ESMs were tested for their cold energy storage performance and thermal properties aging for durability. The empirical results indicate that, for food cold chain, the melting point rule is superior with less deviation. With this information, one can pre-estimate the basic design parameters with great accuracy; the cost of design and development for a new cold storage logistics system can be dramatically reduced. - Highlights: • For these three ESMs, their modified values of melting point and latent heat are presented in Table 2. • But, TC is usually not a constant like TE. • The freezing time underwent a drop ∼10% in the binary eutectic region.

Optical control of spin-dependent thermal transport in a quantum ring

Science.gov (United States)

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.

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

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....

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

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.

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...

Ordered one-component plasmas: Phase transitions, normal modes, large systems, and experiments in a storage ring

International Nuclear Information System (INIS)

Schiffer, J.P.

1994-01-01

The property of cold one-component plasmas, confined by external forces, to form an ordered array has been known for some time both from simulations and from experiment. The purpose of this talk is to summarize some recent work on simulations and some new experimental results. The author discusses some experimental work on real storage rings, magnetic storage devices in which partials circulate with large kinetic energies and for which laser cooling is used on partially ionized ions to attain temperatures ten or more orders of magnitude lower than their kinetic energies

Development of an Acoustic Levitation Linear Transportation System Based on a Ring-Type Structure.

Science.gov (United States)

Thomas, Gilles P L; Andrade, Marco A B; Adamowski, Julio Cezar; Silva, Emilio Carlos Nelli

2017-05-01

A linear acoustic levitation transportation system based on a ring-type vibrator is presented. The system is composed by two 21-kHz Langevin transducers connected to a ring-shaped structure formed by two semicircular sections and two flat plates. In this system, a flexural standing wave is generated along the ring structure, producing an acoustic standing wave between the vibrating ring and a plane reflector located at a distance of approximately a half wavelength from the ring. The acoustic standing wave in air has a series of pressure nodes, where small particles can be levitated and transported. The ring-type transportation system was designed and analyzed by using the finite element method. Additionally, a prototype was built and the acoustic levitation and transport of a small polystyrene particle was demonstrated.

Electron ring design for HERA, including spin-matching

International Nuclear Information System (INIS)

Skuja, A.; Hand, L.; Steffen, K.; Barber, D.

1984-01-01

A. Skuja has been working in collaboration with Professor Lou Hand in obtaining an optics for the electron ring at HERA that satisfies the usual constraints of an electron storage ring, but in addition allows longitudinal polarization in the interaction region without depolarizing the electron beam completely. This collaboration effort grew out of their work on a possible electron ring at Fermilab. When this project was degraded in priority at Fermilab, they turned their attention to the HERA project at DESY. The HERA project will have an electron ring of about 30 GeV e - (or e + ) incident on 800 GeV protons. Recently it has been decided that the collisions should be head on (0 0 crossing), although all previous designs had a crossing angle of the 2 beams of 20 mrad. Professors Hand and Skuja implemented a complete program in the last year and a half that could fit the usual Turis parameters as well as the so called 12 spin-matching conditions of Chao and Yukoya for all possible machine elements including solenoids. The program has the possibility of fully coupling vertical and horizontal motion using the usual eigenvalue method

The spatial distribution of silicoflagellates in the region of the Gulf Stream warm-core ring 82B: application to water mass tracer studies

Science.gov (United States)

Takahashi, Kozo; Blackwelder, Patricia L.

1992-03-01

To delineate potential water mass affinities, we investigated silicoflagellates from the region of Gulf Stream warm-core ring (WCR) 82B in the northwestern Atlantic. Silicoflagellates from 202 samples from N-S and an E-W transects across WCR 82B during late April were analysed. Shelf to Sargasso Sea transects, one completed in early May and the other in June 1982 were also examined. Eight to 11 vertical profiles to 200 m comprised each of the transects. Six taxa of silicoflagellates were found in the samples studied and a total of more than 8000 specimens were encountered. Three major taxa dominated standing stocks: Distephanus speculum, Dictyocha messanensis (intermediate-sized form) and D. mandrai. D. speculum, considered a cold-water taxon in the literature, showed a higher standing stock in the cooler high-velocity region (HVR) of the warm-core ring, continental shelf (SH) and slope (SL) waters. Fewer were present in the wanner ring center (RC), Gulf Stream (GS) and Sargasso Sea (SS). D. mandrai showed a similar distribution to that of D. speculum, but its preference for slightly warmer waters (>~10°C) was noted. In contrast, Dictyocha messanensis (intermediate-sized) and Distephanus pulchra, known to be warm-water taxa, were relatively abundant in the warm ring center. In contrast to standing stock data, ratios between cold- and warm-water taxa correlate well with temperature and salinity in the warm-core ring. Since these ratios are not effected by convective loss, they are excellent water mass tracers in this system. Distribution of the silicoflagellate taxa suggests that WCR82B April had a higher affinity with the Gulf Stream than the Sargasso Sea. Scores derived from factor analysis indicate that silicoflagellate species distributions are highly correlative with water masses. This was evident from correlations with temperature, salinity and with distance from ring center. Nutrients were generally not correlated with species data. This may be due to deep

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)

Preliminary evaluation of the potential of tree-ring cellulose content as a novel supplementary proxy in dendroclimatology

Science.gov (United States)

Ziehmer, Malin M.; Nicolussi, Kurt; Schlüchter, Christian; Leuenberger, Markus

2018-02-01

Cellulose content (CC (%)) in tree rings is usually utilised as a tool to control the quality of the α-cellulose extraction from tree rings in the preparation of stable-isotope analysis in wooden tissues. Reported amounts of CC (%) are often limited to mean values per tree. For the first time, CC (%) series from two high-Alpine species, Larix decidua Mill. (European Larch, LADE) and Pinus cembra L. (Swiss stone pine, PICE) are investigated in modern wood samples and Holocene wood remains from the Early and mid-Holocene. Modern CC (%) series reveal a species-specific low-frequency trend independent of their sampling site over the past 150 years. Climate-cellulose relationships illustrate the ability of CC (%) to record temperature in both species but for slightly different periods within the growing season. The Holocene CC (%) series illustrate diverging low-frequency trends in both species, independent of sampling site characteristics (latitude, longitude and elevation). Moreover, potential age trends are not apparent in the two coniferous species. The arithmetic mean of CC (%) series in the Early and mid-Holocene indicate low CC (%) succeeding cold events. In conclusion, CC (%) in tree rings show high potential to be established as novel supplementary proxy in dendroclimatology.

Wind energy under cold climate conditions

Energy Technology Data Exchange (ETDEWEB)

Maribo Pedersen, B.

1999-03-01

There is an increasing interest in wind energy production under different climatic conditions, among them cold climate and icing conditions. More and more wind turbines are being installed in cold climates and even adapted technology has been developed for that environment. Various national activities are going on in at least Finland, Canada, Italy, Sweden, etc. and international collaboration has been carried out within the European Union's Non-nuclear energy programme. Wind turbine operation is affected by both the cold temperatures and the formation of ice on the blades and the supporting structure. Cold temperatures can be handled by material selections known in other technical fields but to prevent icing, new techniques have to be - and have been - developed. Icing affects the reliability of anemometers, which concerns both turbine control and resource estimation, and changes the aerodynamics of the blades, which eventually stops the turbine. In addition, occasional icing events can locally affect public safety. The development of applied technology has entered some different paths and different solutions are tried out. As the applications are entering a commercial phase, these is a request to gather the experiences and monitor the reliability in a form that can be utilised by developers, manufactureres, consultants and other tenderers. The Topical Experts Meeting will focus on site classification, operational experiences, modelling and mesurements of ice induced loads and safety aspects. (EHS)

Completeness of the ring of polynomials

DEFF Research Database (Denmark)

Thorup, Anders

2015-01-01

Consider the polynomial ring R:=k[X1,…,Xn]R:=k[X1,…,Xn] in n≥2n≥2 variables over an uncountable field k. We prove that R   is complete in its adic topology, that is, the translation invariant topology in which the non-zero ideals form a fundamental system of neighborhoods of 0. In addition we pro...

Challenges in Switching SiC MOSFET without Ringing

DEFF Research Database (Denmark)

Li, Helong; Munk-Nielsen, Stig

2014-01-01

Switching SiC MOSFET without ringing in high frequency applications is important for meeting the EMI (ElectroMagnetic Interference) standard. Achieving a clean switching waveform of SiC MOSFET without additional components is becoming a challenge. In this paper, the switching oscillation mechanis...

Cold formability of steels

International Nuclear Information System (INIS)

Lafond, G.; Leclerq, G.; Moliexe, F.; Namdar, R.; Roesch, L.; Sanz, G.

1977-01-01

This work was essentially aimed to the study of the following three questions. Is it possible to assess the cold formability of steels using simple material properties as criteria. What values of mechanical properties can one expect to reach in cold formed parts. Are there simple ways of characterizing the speroidization treatments carried out on steels before cold forming operations. The present report describes the results obtained during this investigation. It is logically divided into three separate parts. Experimental study of cold formability in wire drawing. Influence of metallurgical variables on mechanical properties of high carbon cold drawn wires. Contribution to the study of characterization methods of cold forming steels subjected to a spheroidization heat treatment

Tree Rings: Timekeepers of the Past.

Science.gov (United States)

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…

Human whole body cold adaptation.

Science.gov (United States)

Daanen, Hein A M; Van Marken Lichtenbelt, Wouter D

2016-01-01

Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000 y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations, but also physiological adaptations to cold. Dedicated studies show that repeated whole body exposure of individual volunteers, mainly Caucasians, to severe cold results in reduced cold sensation but no major physiological changes. Repeated cold water immersion seems to slightly reduce metabolic heat production, while repeated exposure to milder cold conditions shows some increase in metabolic heat production, in particular non-shivering thermogenesis. In conclusion, human cold adaptation in the form of increased metabolism and insulation seems to have occurred during recent evolution in populations, but cannot be developed during a lifetime in cold conditions as encountered in temperate and arctic regions. Therefore, we mainly depend on our behavioral skills to live in and survive the cold.

Activation analysis opportunities using cold neutron beams

Energy Technology Data Exchange (ETDEWEB)

Lindstrom, R M; Zeisler, R; Rossbach, M

1987-05-01

Guided beams of cold neutrons being installed at a number of research reactors may become increasingly available for analytical research. A guided cold beam will provide higher neutron fluence rates and lower background interferences than in present facilities. In an optimized facility, fluence rates of 10/sup 9/ nxcm/sup -2/xs/sup -1/ are obtainable. Focusing a large area beam onto a small target will further increase the neutron intensity. In addition, the shift to lower neutron energy increases the effective cross sections. The absence of fast neutrons and gamma rays permits detectors to be placed near the sample without intolerable background, and thus the efficiency for counting prompt gamma rays can be much higher than in present systems. Measurements made at the hydrogen cold source of the FRJ-2 (DIDO) reactor at the KFA provide a numerical evaluation of the improvements in PGAA with respect to signal-to-background ratios of important elements and matrices. (author) 15 refs.

The effect of tempering on mechanical properties of 50Mn18Cr4WN retaining ring material

International Nuclear Information System (INIS)

Sun, M.C.; Guo, C.H.; Zheng, Z.Z.; Ma, Z.M.

1990-01-01

50Mn18Cr4WN is a retaining ring steel. It is strengthened by solution heat treatment and cold working. The process produces high macro residual stress. The retaining ring must be tempered for stress-relief. When the ring is sleeved, it is heated too. If the retaining ring is tempered, are the mechanical properties of the retaining ring damaged? The problem is described in the article. The tempering of testing pieces was carried out at several temperatures: 350degC, 400degC, 450degC, 500degC and 650degC. The tempering time was 3h. The yield point, tensile strength, elongation and reduction of area were determined by means of the tensile test. In the results, for temperatures between 350degC and 450degC, the yield point, tensile strength, elongation and reduction of area did not change notably. A stress corrosion cracking test was also carried out in a 3%Ni 4 NO 3 , 36%Ca(NO 3 ) 2 aqueous solution. K 1scc values after tempering at 450degC and without tempering were measured. The results showed that the K 1scc after tempering at 450degC decreased notably. Micrographs show that carbo-nitride precipitated. The precipitated carbo-nitride particles increased in size at the grain boundaries. The precipitated carbonitride particles increased in number at slip lines. It is clear that the precipitated particles lead to the increase of micro-cells and the micro-cells aggravated the stress corrosion cracking process. (orig.)

The impact of cold spells on mortality and effect modification by cold spell characteristics

Science.gov (United States)

Wang, Lijun; Liu, Tao; Hu, Mengjue; Zeng, Weilin; Zhang, Yonghui; Rutherford, Shannon; Lin, Hualiang; Xiao, Jianpeng; Yin, Peng; Liu, Jiangmei; Chu, Cordia; Tong, Shilu; Ma, Wenjun; Zhou, Maigeng

2016-12-01

In China, the health impact of cold weather has received little attention, which limits our understanding of the health impacts of climate change. We collected daily mortality and meteorological data in 66 communities across China from 2006 to 2011. Within each community, we estimated the effect of cold spell exposure on mortality using a Distributed Lag Nonlinear Model (DLNM). We also examined the modification effect of cold spell characteristics (intensity, duration, and timing) and individual-specific factors (causes of death, age, gender and education). Meta-analysis method was finally used to estimate the overall effects. The overall cumulative excess risk (CER) of non-accidental mortality during cold spell days was 28.2% (95% CI: 21.4%, 35.3%) compared with non-cold spell days. There was a significant increase in mortality when the cold spell duration and intensity increased or occurred earlier in the season. Cold spell effects and effect modification by cold spell characteristics were more pronounced in south China. The elderly, people with low education level and those with respiratory diseases were generally more vulnerable to cold spells. Cold spells statistically significantly increase mortality risk in China, with greater effects in southern China. This effect is modified by cold spell characteristics and individual-level factors.

Some Aspects of Ring Theory

CERN Document Server

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.

The Ring Current Response to Solar and Interplanetary Storm Drivers

Science.gov (United States)

Mouikis, C.; Kistler, L. M.; Bingham, S.; Kronberg, E. A.; Gkioulidou, M.; Huang, C. L.; Farrugia, C. J.

2014-12-01

The ring current responds differently to the different solar and interplanetary storm drivers such as coronal mass injections, (CME's), corotating interaction regions (CIR's), high-speed streamers and other structures. The resulting changes in the ring current particle pressure, in turn, change the global magnetic field, controlling the transport of the radiation belts. To quantitatively determine the field changes during a storm throughout the magnetosphere, it is necessary to understand the transport, sources and losses of the particles that contribute to the ring current. Because the measured ring current energy spectra depend not only on local processes, but also on the history of the ions along their entire drift path, measurements of ring current energy spectra at two or more locations can be used to strongly constrain the time dependent magnetic and electric fields. In this study we use data predominantly from the Cluster and the Van Allen Probes, covering more than a full solar cycle (from 2001 to 2014). For the period 2001-2012, the Cluster CODIF and RAPID measurements of the inner magnetosphere are the primary data set used to monitor the storm time ring current variability. After 2012, the Cluster data set complements the data from the Van Allen Probes HOPE and RBSPICE instruments, providing additional measurements from different MLT and L shells. Selected storms from this periods, allow us to study the ring current dynamics and pressure changes, as a function of L shell, magnetic local time, and the type of interplanetary disturbances.

Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

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.

Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

Science.gov (United States)

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

THE RING IN THE FOLK STORIES-HALK ANLATILARINDA YÜZÜK

Directory of Open Access Journals (Sweden)

Yaprak Pelin Uluışık

2017-04-01

Full Text Available A ring is not just a piece of jewelry that indicates commitment, endless unity and loyalty; it is a symbol that has a chain of common meanings intertwined with similar features in different geographies. It is seen that rings in myths, epics, legends, fairy tales and folk stories provide features such as power, control, wisdom, youth, earthly and spiritual prosperity, good fortune, invisibility, shape changing, talking with plants and animals. Heroes wearing these rings that protect the human soul from the evil will not suffer in any way. In the stories of the west, it is often mentioned about cursed rings that effects its owner in a bad manner and brings only bad luck. These rings, located in places that can be associated with the underground such as the ground, the hole, the cave and the water bed, are given to the heroes by supernatural beings or wise men. Supernatural beings, such as demons or giants, are trapped in these rings, many of which are magical, as slaves of the rings at an unknown time. When the hero rubs his ring, reverses it, puts it in his mouth; when he hits the ring or whistles to it, the slave of the ring comes out and asks the hero for his wish. This wish is carried out by the slave right after the hero tells the slave what he wishes. In this article, many examples from the Chinese myths to the Arabic tales, from the Babylonian Talmud to the descriptions of Scandinavian, Celtic, Welsh, French and Spanish culture have been examined in order to determine the characteristics of the rings mentioned in folkloric tales. In addition, many examples of Turkish folk literature from Dede Korkut to Anatolian tales were also discussed.

Ring enhancement in recurrent gliomas

International Nuclear Information System (INIS)

Ogashiwa, Motohide; Takeuchi, Kazuo; Akai, Keiichiro

1981-01-01

The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas. (author)

Ring enhancement in recurrent gliomas

Energy Technology Data Exchange (ETDEWEB)

Ogashiwa, M; Takeuchi, K; Akai, K [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

1981-08-01

The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas.

Radar imaging of Saturn's rings

Science.gov (United States)

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

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.

The Quest for Converting Biorenewable Bifunctional α-Methylene-γ-butyrolactone into Degradable and Recyclable Polyester: Controlling Vinyl-Addition/Ring-Opening/Cross-Linking Pathways

KAUST Repository

Tang, Xiaoyan

2016-10-04

α-Methylene-γ-butyrolactone (MBL), a naturally occurring and biomass-sourced bifunctional monomer, contains both a highly reactive exocyclic C═C bond and a highly stable five-membered γ-butyrolactone ring. Thus, all previous work led to exclusive vinyl-addition polymerization (VAP) product P(MBL)VAP. Now, this work reverses this conventional chemoselectivity to enable the first ring-opening polymerization (ROP) of MBL, thereby producing exclusively unsaturated polyester P(MBL)ROP with Mn up to 21.0 kg/mol. This elusive goal was achieved through uncovering the thermodynamic, catalytic, and processing conditions. A third reaction pathway has also been discovered, which is a crossover propagation between VAP and ROP processes, thus affording cross-linked polymer P(MBL)CLP. The formation of the three types of polymers, P(MBL)VAP, P(MBL)CLP, and P(MBL)ROP, can be readily controlled by adjusting the catalyst (La)/initiator (ROH) ratio, which is determined by the unique chemoselectivity of the La–X (X = OR, NR2, R) group. The resulting P(MBL)ROP is degradable and can be readily postfunctionalized into cross-linked or thiolated materials but, more remarkably, can also be fully recycled back to its monomer thermochemically. Computational studies provided the theoretical basis for, and a mechanistic understanding of, the three different polymerization processes and the origin of the chemoselectivity.

The Quest for Converting Biorenewable Bifunctional α-Methylene-γ-butyrolactone into Degradable and Recyclable Polyester: Controlling Vinyl-Addition/Ring-Opening/Cross-Linking Pathways

KAUST Repository

Tang, Xiaoyan; Hong, Miao; Falivene, Laura; Caporaso, Lucia; Cavallo, Luigi; Chen, Eugene Y X

2016-01-01

α-Methylene-γ-butyrolactone (MBL), a naturally occurring and biomass-sourced bifunctional monomer, contains both a highly reactive exocyclic C═C bond and a highly stable five-membered γ-butyrolactone ring. Thus, all previous work led to exclusive vinyl-addition polymerization (VAP) product P(MBL)VAP. Now, this work reverses this conventional chemoselectivity to enable the first ring-opening polymerization (ROP) of MBL, thereby producing exclusively unsaturated polyester P(MBL)ROP with Mn up to 21.0 kg/mol. This elusive goal was achieved through uncovering the thermodynamic, catalytic, and processing conditions. A third reaction pathway has also been discovered, which is a crossover propagation between VAP and ROP processes, thus affording cross-linked polymer P(MBL)CLP. The formation of the three types of polymers, P(MBL)VAP, P(MBL)CLP, and P(MBL)ROP, can be readily controlled by adjusting the catalyst (La)/initiator (ROH) ratio, which is determined by the unique chemoselectivity of the La–X (X = OR, NR2, R) group. The resulting P(MBL)ROP is degradable and can be readily postfunctionalized into cross-linked or thiolated materials but, more remarkably, can also be fully recycled back to its monomer thermochemically. Computational studies provided the theoretical basis for, and a mechanistic understanding of, the three different polymerization processes and the origin of the chemoselectivity.

Viscosity of ring polymer melts

KAUST Repository

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.

Viscosity of ring polymer melts

KAUST Repository

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.

Læring og refleksion

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....

Birth Control Ring

Science.gov (United States)

... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Ring KidsHealth / For Teens / Birth Control Ring What's ...

Tricuspid annuloplasty with the MC3 ring and septal plication technique.

Science.gov (United States)

Isomura, Tadashi; Hirota, Masanori; Hoshino, Joji; Fukada, Yasuhisa; Kondo, Taichi; Takahashi, Yu

2015-01-01

Functional tricuspid regurgitation is caused by annular dilation mainly in the posterior annulus. However, ring annuloplasty does not always prevent the recurrence of tricuspid regurgitation due to dilation of the septal annulus. We developed a septal plication technique with a 3-dimensional MC3 ring. Between 2006 and 2011, 76 patients (male/female 30/46; mean age 68 ± 11 years) with functional tricuspid regurgitation received tricuspid ring annuloplasty. After placement of the annular sutures, the 3 commissural ring portions were fixed on the equivalent commissures to plicate the anterior and posterior annulus. The end of the septal ring portion was fixed at the optimal annular position to obtain minimal tricuspid regurgitation. All patients were followed-up for a mean of 47 ± 18 months; the longest duration was 79 months. Although there was no operative death, one patient died of sepsis during hospitalization (hospital mortality 1.3%). After implantation of the MC3 ring (mean size 31.0 ± 3.3 mm), additional edge-to-edge sutures were required for minor leakage in 5 (7%) patients. The degree of tricuspid regurgitation was significantly reduced at discharge (0.5 ± 0.6) and midterm (0.6 ± 0.6) compared to 2.5 ± 0.7 before the operation (p tricuspid ring annuloplasty with a 3-dimensional MC3 ring. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

From coffee ring to spherulites ring of poly(ethylene oxide) film from drying droplet

Science.gov (United States)

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.

Systematic Search for Rings around Kepler Planet Candidates: Constraints on Ring Size and Occurrence Rate

Science.gov (United States)

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.

Ring tests on high density polyethylene: Full investigation assisted by finite element modeling

International Nuclear Information System (INIS)

Laiarinandrasana, L.; Devilliers, C.; Oberti, S.; Gaudichet, E.; Fayolle, B.; Lucatelli, J.M.

2011-01-01

In order to characterize the mechanical behavior of HDPE pipes, the ASTM D 2290-04 standard recommends carrying out tensile tests on notched rings, cut out from the pipe. This very simple test is also utilized to investigate the aging effect of the pipe by determining the strain at failure. Comparison between full ring and notched ring mechanical responses are discussed. Constitutive modeling including strain rate effects was performed by finite element analysis. This allowed a better understanding of the stress state in the cross section perpendicular to the loading direction. Additionally, the influence of a thin layer of oxidized HDPE in the inner wall of the ring was studied in the light of the finite element results.

Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock-induced oxidation.

Science.gov (United States)

Borowiec, Anne-Sophie; Sion, Benoit; Chalmel, Frédéric; D Rolland, Antoine; Lemonnier, Loïc; De Clerck, Tatiana; Bokhobza, Alexandre; Derouiche, Sandra; Dewailly, Etienne; Slomianny, Christian; Mauduit, Claire; Benahmed, Mohamed; Roudbaraki, Morad; Jégou, Bernard; Prevarskaya, Natalia; Bidaux, Gabriel

2016-09-01

Testes of most male mammals present the particularity of being externalized from the body and are consequently slightly cooler than core body temperature (4-8°C below). Although, hypothermia of the testis is known to increase germ cells apoptosis, little is known about the underlying molecular mechanisms, including cold sensors, transduction pathways, and apoptosis triggers. In this study, using a functional knockout mouse model of the cold and menthol receptors, dubbed transient receptor potential melastatine 8 (TRPM8) channels, we found that TRPM8 initiated the cold-shock response by differentially modulating cold- and heat-shock proteins. Besides, apoptosis of germ cells increased in proportion to the cooling level in control mice but was independent of temperature in knockout mice. We also observed that the rate of germ cell death correlated positively with the reactive oxygen species level and negatively with the expression of the detoxifying enzymes. This result suggests that the TRPM8 sensor is a key determinant of germ cell fate under hypothermic stimulation.-Borowiec, A.-S., Sion, B., Chalmel, F., Rolland, A. D., Lemonnier, L., De Clerck, T., Bokhobza, A., Derouiche, S., Dewailly, E., Slomianny, C., Mauduit, C., Benahmed, M., Roudbaraki, M., Jégou, B., Prevarskaya, N., Bidaux, G. Cold/menthol TRPM8 receptors initiate the cold-shock response and protect germ cells from cold-shock-induced oxidation. © The Author(s).

Numerical modeling of the plasma ring acceleration experiment

International Nuclear Information System (INIS)

Eddleman, J.L.; Hammer, J.H.; Hartman, C.W.

1987-01-01

Modeling of the LLNL RACE experiment and its many applications has necessitated the development and use of a wide array of computational tools. The two-dimensional MHD code, HAM, has been used to model the formation of a compact torus plasma ring in a magnetized coaxial gun and its subsequent acceleration by an additional applied toroidal field. Features included in the 2-D calculations are self-consistent models for (1) the time-dependent poloidal field produced by a capacitor bank discharge through a solenoid field coil (located either inside the gun inner electrode or outside the outer gun electrode) and the associated diffusion of magnetic flux through neighboring conductors, (2) gas flow into the gun annular region from a simulated puffed gas valve plenum, (3) formation and motion of a current sheet produced by J x B forces resulting from discharge of the gun capacitor bank through the plasma load between the coaxial gun electrodes, (4) the subsequent stretching and reconnection of the poloidal field lines to form a compact torus plasma ring, and (5) finally the discharge of the accelerator capacitor bank producing an additional toroidal field for acceleration of the plasma ring. The code has been extended to include various models for gas breakdown, plasma anomalous resistivity, and mass entrainment from ablation of electrode material

Cold stress alters transcription in meiotic anthers of cold tolerant chickpea (Cicer arietinum L.).

Science.gov (United States)

Sharma, Kamal Dev; Nayyar, Harsh

2014-10-11

Cold stress at reproductive phase in susceptible chickpea (Cicer arietinum L.) leads to pollen sterility induced flower abortion. The tolerant genotypes, on the other hand, produce viable pollen and set seed under cold stress. Genomic information on pollen development in cold-tolerant chickpea under cold stress is currently unavailable. DDRT-PCR analysis was carried out to identify anther genes involved in cold tolerance in chickpea genotype ICC16349 (cold-tolerant). A total of 9205 EST bands were analyzed. Cold stress altered expression of 127 ESTs (90 up-regulated, 37 down-regulated) in anthers, more than two third (92) of which were novel with unknown protein identity and function. Remaining about one third (35) belonged to several functional categories such as pollen development, signal transduction, ion transport, transcription, carbohydrate metabolism, translation, energy and cell division. The categories with more number of transcripts were carbohydrate/triacylglycerol metabolism, signal transduction, pollen development and transport. All but two transcripts in these categories were up-regulated under cold stress. To identify time of regulation after stress and organ specificity, expression levels of 25 differentially regulated transcripts were also studied in anthers at six time points and in four organs (anthers, gynoecium, leaves and roots) at four time points. Limited number of genes were involved in regulating cold tolerance in chickpea anthers. Moreover, the cold tolerance was manifested by up-regulation of majority of the differentially expressed transcripts. The anthers appeared to employ dual cold tolerance mechanism based on their protection from cold by enhancing triacylglycerol and carbohydrate metabolism; and maintenance of normal pollen development by regulating pollen development genes. Functional characterization of about two third of the novel genes is needed to have precise understanding of the cold tolerance mechanisms in chickpea anthers.

A Fast Recommender System for Cold User Using Categorized Items

Directory of Open Access Journals (Sweden)

Hamid Jazayeriy

2018-01-01

Full Text Available In recent years, recommender systems (RS provide a considerable progress to users. RSs reduce the cost of a user’s time in order to reach to desired results faster. The main issue of RSs is the presence of cold users which are less active and their preferences are more difficult to detect. The aim of this study is to provide a new way to improve recall and precision in recommender systems for cold users. According to the available categories of items, prioritization of the proposed items is improved and then presented to the cold user. The obtained results show that in addition to increased speed of processing, recall and precision have an acceptable improvement.

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

Powder consolidation using cold spray process modeling and emerging applications

CERN Document Server

Moridi, Atieh

2017-01-01

This book first presents different approaches to modeling of the cold spray process with the aim of extending current understanding of its fundamental principles and then describes emerging applications of cold spray. In the coverage of modeling, careful attention is devoted to the assessment of critical and erosion velocities. In order to reveal the phenomenological characteristics of interface bonding, severe, localized plastic deformation and material jet formation are studied. Detailed consideration is also given to the effect of macroscopic defects such as interparticle boundaries and subsequent splat boundary cracking on the mechanical behavior of cold spray coatings. The discussion of applications focuses in particular on the repair of damaged parts and additive manufacturing in various disciplines from aerospace to biomedical engineering. Key aspects include a systematic study of defect shape and the ability of cold spray to fill the defect, examination of the fatigue behavior of coatings for structur...

Cough & Cold Medicine Abuse

Science.gov (United States)

... Videos for Educators Search English Español Cough & Cold Medicine Abuse KidsHealth / For Teens / Cough & Cold Medicine Abuse ... resfriado Why Do People Use Cough and Cold Medicines to Get High? There's an ingredient in many ...

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

Multiplicative Structure and Hecke Rings of Generator Matrices for Codes over Quotient Rings of Euclidean Domains

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.

Molecular cytogenetic analysis and clinical manifestations of a case with de novo mosaic ring chromosome 7

Directory of Open Access Journals (Sweden)

Fang Jye-Siung

2011-02-01

Full Text Available Abstract Aim Clinical and molecular cytogenetic investigations of a newborn girl exhibiting facial dysmorphism with developmental delay. Methods Phenotypic evaluation was first applied to examine the proband's developmental status. Computed tomography and colour transcranial Doppler were used then to investigate her brain structure and function. Subsequently, chromosomal abnormalities were examined by karyotyping and fluorescent in situ hybridization was performed to investigate size of fragments lost at the two distal ends of the ring chromosome 7. In addition, multicolour banding was applied to rule out structural rearrangement occurs in between the ring chromosome 7. Results The proband was born with mosaic supernumerary ring chromosome 7, without a normal karyotype detected in the peripheral blood lymphocytes. The distal arm of chromosome 7p (at least 255 kb from the telomere was part of an extra ring chromosome 7. In addition, the distal arm of 7q, at least 8 kb from the telomere, was missing. There was no other chromosomal rearrangement detected by multicolour banding. Interpretation This is the 19th reported case of complete ring chromosome 7 mosaicism and the first survived case with mosaic supernumerary ring 7 without a normal karyotype detected in the peripheral lymphocytes.

Binomial Rings: Axiomatisation, Transfer and Classification

OpenAIRE

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.

Plasma confinement in a magnetic field of the internal ring current

International Nuclear Information System (INIS)

Shafranov, Vitaly; Popovich, Paul; Samitov, Marat

2000-01-01

Plasma confinement in compact region surrounding an internal ring current is considered. As the limiting case of large aspect ratio system the cylindrical plasma is considered initially. Analysis of the cylindrical tubular plasma equilibrium and stability against the most dangerous flute (m=0) and kink (m=1) modes revealed the possibility of the MHD stable plasma confined by magnetic field of the internal rod current, with rather peaked plasma pressure and maximal local beta β(γ)=0.4. In case of the toroidal internal ring system an additional external magnetic field creates the boundary separatrix witch limits the plasma volume. The dependence of the plasma pressure profiles, marginally stable with respect to the flute modes, from the shape of the external plasma boundary (separatrix) in such kind closed toroidal systems is investigated. The internal ring system with circular poloidal magnetic mirror, where the ring supports could be placed, is proposed. (author)

Astrochemical Properties of Planck Cold Clumps

Energy Technology Data Exchange (ETDEWEB)

Tatematsu, Ken’ichi; Sanhueza, Patricio; Nguyễn Lu’o’ng, Quang; Hirota, Tomoya [National Astronomical Observatory of Japan, National Institutes of Natural Sciences, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Liu, Tie; Choi, Minho; Kang, Miju; Kim, Kee-Tae [Korea Astronomy and Space Science Institute, Daedeokdaero 776, Yuseong, Daejeon 305-348 (Korea, Republic of); Ohashi, Satoshi [Department of Astronomy, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Liu, Sheng-Yuan; Hirano, Naomi [Academia Sinica Institute of Astronomy and Astrophysics, 11F of Astronomy-Mathematics Building, AS/NTU. No.1, Section 4, Roosevelt Rd, Taipei 10617, Taiwan (China); Thompson, Mark A. [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield, AL10 9AB (United Kingdom); Fuller, Gary [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Wu, Yuefang [Department of Astronomy, Peking University, 100871, Beijing (China); Li, Di [National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 (China); Francesco, James Di [NRC Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Wang, Ke [European Southern Observatory (Germany); Ristorcelli, Isabelle [IRAP, CNRS (UMR5277), Universite Paul Sabatier, 9 avenue du Colonel Roche, BP 44346, F-31028, Toulouse Cedex 4 (France); Juvela, Mika [Department of physics, University of Helsinki, FI-00014, Helsinki (Finland); Shinnaga, Hiroko, E-mail: k.tatematsu@nao.ac.jp [Department of Physics, Kagoshima University, 1-21-35, Korimoto, Kagoshima, 890-0065 (Japan); Collaboration: JCMT Large Program “SCOPE” collaboration; TRAO Key Science Program “TOP” collaboration; and others

2017-02-01

We observed 13 Planck cold clumps with the James Clerk Maxwell Telescope/SCUBA-2 and with the Nobeyama 45 m radio telescope. The N{sub 2}H{sup +} distribution obtained with the Nobeyama telescope is quite similar to SCUBA-2 dust distribution. The 82 GHz HC{sub 3}N, 82 GHz CCS, and 94 GHz CCS emission are often distributed differently with respect to the N{sub 2}H{sup +} emission. The CCS emission, which is known to be abundant in starless molecular cloud cores, is often very clumpy in the observed targets. We made deep single-pointing observations in DNC, HN{sup 13}C, N{sub 2}D{sup +}, and cyclic-C{sub 3}H{sub 2} toward nine clumps. The detection rate of N{sub 2}D{sup +} is 50%. Furthermore, we observed the NH{sub 3} emission toward 15 Planck cold clumps to estimate the kinetic temperature, and confirmed that most targets are cold (≲20 K). In two of the starless clumps we observed, the CCS emission is distributed as it surrounds the N{sub 2}H{sup +} core (chemically evolved gas), which resembles the case of L1544, a prestellar core showing collapse. In addition, we detected both DNC and N{sub 2}D{sup +}. These two clumps are most likely on the verge of star formation. We introduce the chemical evolution factor (CEF) for starless cores to describe the chemical evolutionary stage, and analyze the observed Planck cold clumps.

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

Galactic rings revisited - I. CVRHS classifications of 3962 ringed galaxies from the Galaxy Zoo 2 Database

Science.gov (United States)

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.

Temperature variability over the past millennium inferred from Northwestern Alaska tree rings

Energy Technology Data Exchange (ETDEWEB)

D' Arrigo, Rosanne; Mashig, Erika; Jacoby, Gordon [Lamont-Doherty Earth Observatory, Tree-Ring Laboratory, Palisades, NY (United States); Frank, David [WSL, Birmensdorf (Switzerland); Wilson, Rob [University of Edinburgh, School of Geosciences, Grant Institute, Edinburgh (United Kingdom)

2005-02-01

We describe a new tree-ring width data set of 14 white spruce chronologies for the Seward Peninsula (SP), Alaska, based on living and subfossil wood dating from 1358 to 2001 AD. A composite chronology derived from these data correlates positively and significantly with summer temperatures at Nome from 1910 to 1970, after which there is some loss of positive temperature response. There is inferred cooling during periods within the Little Ice Age (LIA) from the early to middle 1600s and late 1700s to middle 1800s; and warming from the middle 1600s to early 1700s. We also present a larger composite data set covering 978-2001 AD, utilizing the SP ring-width data in combination with archaeological wood measurements and other recent collections from northwestern Alaska. The Regional Curve Standardization (RCS) method was employed to maximize potential low-frequency information in this data set. The RCS chronology shows intervals of persistent above-average growth around the time of the Medieval Warm Period (MWP) early in the millennium, which are comparable to growth levels in recent centuries. There is a more sustained cold interval during the LIA inferred from the RCS record as compared to the SP ring-width series. The chronologies correlate significantly with Bering and Chukchi Sea sea surface temperatures and with the Pacific Decadal Oscillation index. These atmosphere-ocean linkages probably account for the differences between these records and large-scale reconstructions of Arctic and Northern Hemisphere temperatures based largely on continental interior proxy data. (orig.)

Causes of ring-related leg injuries in birds - evidence and recommendations from four field studies.

Directory of Open Access Journals (Sweden)

Michael Griesser

Full Text Available One of the main techniques for recognizing individuals in avian field research is marking birds with plastic and metal leg rings. However, in some species individuals may react negatively to rings, causing leg injuries and, in extreme cases, the loss of a foot or limb. Here, we report problems that arise from ringing and illustrate solutions based on field data from Brown Thornbills (Acanthiza pusilla (2 populations, Siberian Jays (Perisoreus infaustus and Purple-crowned Fairy-wrens (Malurus coronatus. We encountered three problems caused by plastic rings: inflammations triggered by material accumulating under the ring (Purple-crowned Fairy-wrens, contact inflammations as a consequence of plastic rings touching the foot or tibio-tarsal joint (Brown Thornbills, and toes or the foot getting trapped in partly unwrapped flat-band colour rings (Siberian Jays. Metal rings caused two problems: the edges of aluminium rings bent inwards if mounted on top of each other (Brown Thornbills, and too small a ring size led to inflammation (Purple-crowned Fairy-wrens. We overcame these problems by changing the ringing technique (using different ring types or larger rings, or using different adhesive. Additionally, we developed and tested a novel, simple technique of gluing plastic rings onto metal rings in Brown Thornbills. A review of studies reporting ring injuries (N = 23 showed that small birds (35 g tend to get rings stuck over their feet. We give methodological advice on how these problems can be avoided, and suggest a ringing hazard index to compare the impact of ringing in terms of injury on different bird species. Finally, to facilitate improvements in ringing techniques, we encourage online deposition of information regarding ringing injuries of birds at a website hosted by the European Union for Bird Ringing (EURING.

Quantum Fourier Transform Over Galois Rings

OpenAIRE

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...

Ring species as demonstrations of the continuum of species formation

DEFF Research Database (Denmark)

Pereira, Ricardo José Do Nascimento; Wake, David B.

2015-01-01

In the mid-20th century, Ernst Mayr (1942) and Theodosius Dobzhansky (1958) championed the significance of 'circular overlaps' or 'ring species' as the perfect demonstration of the gradual nature of species formation. As an ancestral species expands its range, wrapping around a geographic barrier......? What conditions favour their formation? Modelling studies have attempted to address these knowledge gaps by estimating the biological parameters that result in stable ring species (Martins et al. 2013), and determining the necessary topographic parameters of the barriers encircled (Monahan et al. 2012......). However, any generalization is undermined by a major limitation: only a handful of ring species are known to exist in nature. In addition, many of them have been broken into multiple species presumed to be evolving independently, usually obscuring the evolutionary dynamics that generate diversity. A paper...

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)

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.

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 ...

Biomarkers and biometric measures of adherence to use of ARV-based vaginal rings.

Science.gov (United States)

Stalter, Randy M; Moench, Thomas R; MacQueen, Kathleen M; Tolley, Elizabeth E; Owen, Derek H

2016-01-01

Poor adherence to product use has been observed in recent trials of antiretroviral (ARV)-based oral and vaginal gel HIV prevention products, resulting in an inability to determine product efficacy. The delivery of microbicides through vaginal rings is widely perceived as a way to achieve better adherence but vaginal rings do not eliminate the adherence challenges exhibited in clinical trials. Improved objective measures of adherence are needed as new ARV-based vaginal ring products enter the clinical trial stage. To identify technologies that have potential future application for vaginal ring adherence measurement, a comprehensive literature search was conducted that covered a number of biomedical and public health databases, including PubMed, Embase, POPLINE and the Web of Science. Published patents and patent applications were also searched. Technical experts were also consulted to gather more information and help evaluate identified technologies. Approaches were evaluated as to feasibility of development and clinical trial implementation, cost and technical strength. Numerous approaches were identified through our landscape analysis and classified as either point measures or cumulative measures of vaginal ring adherence. Point measurements are those that give a measure of adherence at a particular point in time. Cumulative measures attempt to measure ring adherence over a period of time. Approaches that require modifications to an existing ring product are at a significant disadvantage, as this will likely introduce additional regulatory barriers to the development process and increase manufacturing costs. From the point of view of clinical trial implementation, desirable attributes would be high acceptance by trial participants, and little or no additional time or training requirements on the part of participants or clinic staff. We have identified four promising approaches as being high priority for further development based on the following measurements

Status of rf development work on a ferrite tuned amplifier cavity for the TRIUMF KAON factory booster ring

International Nuclear Information System (INIS)

Poirier, R.L.; Enegren, T.

1987-01-01

Of the five synchrotron rings in the proposed TRIUMF KAON factory, the Booster ring to accelerate the proton beam from 440 MeV to 3 GeV has the most demanding rf requirements, primarily because of the relatively large frequency swing of 46.1 MHz to 61.1 MHz at a high repetition rate of 50 Hz. In the current reference design, the Booster lattice has twelve 3.9 m drift spaces with 2.5 m in each drift space available for installation of rf cavities to provide a required effective acceleration voltage of up to 600 kV per turn i.e. 50 kV per cavity. Design and development studies of a suitable cavity-amplifier system are in progress. For the initial reference design a system based on the one used in the Fermilab booster synchrotron has been chosen. That is, a double-gap drift-tube cavity with parallel-biased ferrite tuners and excited with a directly coupled Eimac Y567B tetrode. To meet the tuning and voltage requirements within the various mechanical and other constraints such as tube-to-gap voltage ratio, ferrite power density and available space, the reference design had to be further modified and a cold model of the cavity and tuners was constructed from copper-covered cardboard cylinders. From the results of the cold model measurements a new reference design was established and design work has begun on a full power prototype of the cavity-amplifier system

Design Method for Proportion of Cement-Foamed Asphalt Cold Recycled Mixture

Directory of Open Access Journals (Sweden)

Li Junxiao

2018-01-01

Full Text Available Through foaming experiment of Zhongtai AH-70 asphalt, the best foaming temperature water consumption and influence factors of foamed asphalt’s foaming features are determined; By designing the proportion of foamed asphalt cold in-place recycled mixture combined with the water stability experiment, for this mixture the best foamed asphalt addition is 3%, and proportion of the mixture is RAP: fine aggregate: cement=75:23:2. Using SEM technology, the mechanism of increasing on the intensity of foamed asphalt mixture resulted by the addition of cement was analysed. This research provides reference for cement admixture’s formulation in the designing of foamed asphalt cold in-place recycled mixture.

Model calibration and beam control systems for storage rings

International Nuclear Information System (INIS)

Corbett, W.J.; Lee, M.J.; Ziemann, V.

1993-04-01

Electron beam storage rings and linear accelerators are rapidly gaining worldwide popularity as scientific devices for the production of high-brightness synchrotron radiation. Today, everybody agrees that there is a premium on calibrating the storage ring model and determining errors in the machine as soon as possible after the beam is injected. In addition, the accurate optics model enables machine operators to predictably adjust key performance parameters, and allows reliable identification of new errors that occur during operation of the machine. Since the need for model calibration and beam control systems is common to all storage rings, software packages should be made that are portable between different machines. In this paper, we report on work directed toward achieving in-situ calibration of the optics model, detection of alignment errors, and orbit control techniques, with an emphasis on developing a portable system incorporating these tools

Finite-size effects in the dynamics of few bosons in a ring potential

Science.gov (United States)

Eriksson, G.; Bengtsson, J.; Karabulut, E. Ö.; Kavoulakis, G. M.; Reimann, S. M.

2018-02-01

We study the temporal evolution of a small number N of ultra-cold bosonic atoms confined in a ring potential. Assuming that initially the system is in a solitary-wave solution of the corresponding mean-field problem, we identify significant differences in the time evolution of the density distribution of the atoms when it instead is evaluated with the many-body Schrödinger equation. Three characteristic timescales are derived: the first is the period of rotation of the wave around the ring, the second is associated with a ‘decay’ of the density variation, and the third is associated with periodic ‘collapses’ and ‘revivals’ of the density variations, with a factor of \\sqrt{N} separating each of them. The last two timescales tend to infinity in the appropriate limit of large N, in agreement with the mean-field approximation. These findings are based on the assumption of the initial state being a mean-field state. We confirm this behavior by comparison to the exact solutions for a few-body system stirred by an external potential. We find that the exact solutions of the driven system exhibit similar dynamical features.

Faithfully quadratic rings

CERN Document Server

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

BERKELEY: ALS ring

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)

Compressible Vortex Ring

Science.gov (United States)

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.

BERKELEY: ALS ring

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)

A pilot study exploring the effects of reflexology on cold intolerance.

Science.gov (United States)

Zhang, Wenping; Takahashi, Shougo; Miki, Takashi; Fujieda, Hisayo; Ishida, Torao

2010-03-01

Cold intolerance is an inability to tolerate cold temperatures and is accompanied by symptoms including headache, shoulder discomfort, dizziness and palpitations. The current study was performed to examine whether reflexology therapy affected cold intolerance in human subjects and whether the treatment was systemically effective. Ten female volunteer examinees with subjective feelings of cold were examined. After a 5-minute foot bath, 10 minutes of reflexology therapy was performed on their left foot. Skin temperature and blood flow were estimated before and after treatment, together with an interview concerning their feelings of cold and daily habits. In addition, how the recovery rate was affected by the application of a chilled-water load was also estimated. Along with significant increases in skin temperature and blood flow compared with pre-treatment at the bilateral points of KI-1, LR-3, and BL-60, a faster recovery after the application of the chilled-water load was also seen in the lower limbs on both sides. From these results, we conclude that reflexology has systemic effects and is an alternative method for treating cold intolerance. Copyright (c) 2010 Korean Pharmacopuncture Institute. Published by .. All rights reserved.

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

Relationship between carbon-14 concentrations in tree-ring cellulose and atmospheric CO2

International Nuclear Information System (INIS)

Yamada, Yoshimune; Yasuike, Kaeko; Komura, Kazuhisa

2008-01-01

Concentrations of organically-bound 14 C in the tree-ring cellulose of a Japanese Cedar (Cryptomeria japonica) grown in a rural region of Kanazawa, Ishikawa prefecture, Japan (36.5degN, 136.7degE), were measured for the ring-years from 1989 to 1998 to study relationship between 14 C concentrations in tree-ring cellulose and atmospheric CO 2 in a narrow region. An interesting result in comparing our data of tree-ring cellulose with those of atmospheric CO 2 is that the 14 C concentration in tree-ring cellulose was close to the corresponding average from mid-June to early September of 14 C concentrations in atmospheric CO 2 . Furthermore, the 14 C concentrations in tree-ring cellulose were found to be merely influenced by the drastic decrease of 14 C concentrations in atmospheric CO 2 in winter, which might be caused by air pollution from the Asian continent and additional local fossil fuel contribution. These results suggest that the 14 C concentration in tree-ring cellulose for a given growing year reflects the 14 C concentrations of atmospheric CO 2 during the warm summer months. (author)

Transcriptome Profiling of the Pineapple under Low Temperature to Facilitate Its Breeding for Cold Tolerance

Science.gov (United States)

Chen, Chengjie; Zhang, Yafeng; Xu, Zhiqiang; Luan, Aiping; Mao, Qi; Feng, Junting; Xie, Tao; Gong, Xue; Wang, Xiaoshuang; Chen, Hao; He, Yehua

2016-01-01

The pineapple (Ananas comosus) is cold sensitive. Most cultivars are injured during winter periods, especially in sub-tropical regions. There is a lack of molecular information on the pineapple’s response to cold stress. In this study, high-throughput transcriptome sequencing and gene expression analysis were performed on plantlets of a cold-tolerant genotype of the pineapple cultivar ‘Shenwan’ before and after cold treatment. A total of 1,186 candidate cold responsive genes were identified, and their credibility was confirmed by RT-qPCR. Gene set functional enrichment analysis indicated that genes related to cell wall properties, stomatal closure and ABA and ROS signal transduction play important roles in pineapple cold tolerance. In addition, a protein association network of CORs (cold responsive genes) was predicted, which could serve as an entry point to dissect the complex cold response network. Our study found a series of candidate genes and their association network, which will be helpful to cold stress response studies and pineapple breeding for cold tolerance. PMID:27656892

Plasmon-induced transparency in ring-bar meta-atom

Directory of Open Access Journals (Sweden)

Wan-Xia Huang

2018-03-01

Full Text Available We introduce an approach for constructing a scalable metamaterial structure, which is composed of a ring and a bar in a unit cell, and supports singular plasmon-induced transparency. The composite multilayered structure consists of coupled meta-atom with bright modes and dark modes interacting through the introduction of structural asymmetry, which involves the displacement of the bar from the center of the ring. The splitting and merging of the absorption peaks is observed with the change in asymmetric degree. In addition, coupled-mode theory with a two-mode and two-port model is introduced to explain the observed novel spectral feature. The results provide a reference for further application to optoelectronic devices.

Microstructure Evolution and Mechanical Behavior of 2219 Aluminum Alloys Additively Fabricated by the Cold Metal Transfer Process

Directory of Open Access Journals (Sweden)

Xuewei Fang

2018-05-01

Full Text Available In this research, four different welding arc modes including conventional cold metal transfer (CMT, CMT-Pulse (CMT-P, CMT-Advanced (CMT-ADV, and CMT pulse advanced (CMT-PADV were used to deposit 2219-Al wire. The effects of different arc modes on porosity, pore size distribution, microstructure evolution, and mechanical properties were thoroughly investigated. The statistical analysis of the porosity and its size distribution indicated that the CMT-PADV process gave the smallest pore area percentage and pore aspect ratio, and had almost no larger pores. The results from optical microscopy, scanning electron microscopy, and fractographic morphology proved that uniform and fine equiaxed grains, evenly distributed Al2Cu second phase particles were formed during the CMT-PADV process. Furthermore, the X-ray diffraction test ascertained that the CMT-PADV sample had the smallest lattice parameter and the highest solute Cu content. Besides, the tensile strength could reach 283 MPa, the data scattering was the smallest, and the strength scattering of the sample in the horizontal direction was the shortest. In addition, the strength properties were nearly isotropic, with only 5 MPa difference in the vertical and horizontal directions. The above mentioned results indicated that the mechanical properties of 2219 aluminum alloy was improved using the CMT-PADV arc mode.

Microstructure Evolution and Mechanical Behavior of 2219 Aluminum Alloys Additively Fabricated by the Cold Metal Transfer Process.

Science.gov (United States)

Fang, Xuewei; Zhang, Lijuan; Li, Hui; Li, Chaolong; Huang, Ke; Lu, Bingheng

2018-05-16

In this research, four different welding arc modes including conventional cold metal transfer (CMT), CMT-Pulse (CMT-P), CMT-Advanced (CMT-ADV), and CMT pulse advanced (CMT-PADV) were used to deposit 2219-Al wire. The effects of different arc modes on porosity, pore size distribution, microstructure evolution, and mechanical properties were thoroughly investigated. The statistical analysis of the porosity and its size distribution indicated that the CMT-PADV process gave the smallest pore area percentage and pore aspect ratio, and had almost no larger pores. The results from optical microscopy, scanning electron microscopy, and fractographic morphology proved that uniform and fine equiaxed grains, evenly distributed Al₂Cu second phase particles were formed during the CMT-PADV process. Furthermore, the X-ray diffraction test ascertained that the CMT-PADV sample had the smallest lattice parameter and the highest solute Cu content. Besides, the tensile strength could reach 283 MPa, the data scattering was the smallest, and the strength scattering of the sample in the horizontal direction was the shortest. In addition, the strength properties were nearly isotropic, with only 5 MPa difference in the vertical and horizontal directions. The above mentioned results indicated that the mechanical properties of 2219 aluminum alloy was improved using the CMT-PADV arc mode.

Microstructure Evolution and Mechanical Behavior of 2219 Aluminum Alloys Additively Fabricated by the Cold Metal Transfer Process

Science.gov (United States)

Fang, Xuewei; Li, Hui; Li, Chaolong; Lu, Bingheng

2018-01-01

In this research, four different welding arc modes including conventional cold metal transfer (CMT), CMT-Pulse (CMT-P), CMT-Advanced (CMT-ADV), and CMT pulse advanced (CMT-PADV) were used to deposit 2219-Al wire. The effects of different arc modes on porosity, pore size distribution, microstructure evolution, and mechanical properties were thoroughly investigated. The statistical analysis of the porosity and its size distribution indicated that the CMT-PADV process gave the smallest pore area percentage and pore aspect ratio, and had almost no larger pores. The results from optical microscopy, scanning electron microscopy, and fractographic morphology proved that uniform and fine equiaxed grains, evenly distributed Al2Cu second phase particles were formed during the CMT-PADV process. Furthermore, the X-ray diffraction test ascertained that the CMT-PADV sample had the smallest lattice parameter and the highest solute Cu content. Besides, the tensile strength could reach 283 MPa, the data scattering was the smallest, and the strength scattering of the sample in the horizontal direction was the shortest. In addition, the strength properties were nearly isotropic, with only 5 MPa difference in the vertical and horizontal directions. The above mentioned results indicated that the mechanical properties of 2219 aluminum alloy was improved using the CMT-PADV arc mode. PMID:29772708

Ring Coils on the Endcap Yoke of a CLIC Detector

CERN Document Server

Gerwig, H

2011-01-01

Ring coils on the endcap return yoke can be useful in several ways. Depending on their size and the current chosen, they may either be used to reduce the fringe-field outside the return yoke of a detector, or to reduce considerably the thickness of the endcap yoke. The main focus of this note is the analysis of the ring coils, with the aim to reduce the overall length of the CLIC_ILD detector. In addition, some results concerning the fringe field in the vicinity of the detector are shown.

A simple scheme for injection and extraction in compact rings

International Nuclear Information System (INIS)

Xu, H. S.; Huang, W. H.; Tang, C. X.

2014-01-01

There has been great interest in building compact synchrotrons for various applications, for example, inverse Compton scattering X-ray sources. However, the beam injection and extraction in compact rings require careful design for the lack of space. In this paper, we propose a simple combined injection-extraction scheme exploiting the fringe field of existing dipole magnets instead of additional septum magnets. This scheme is illustrated by using the 4.8 m ring proposed for Tsinghua Thomson scattering X-ray source as an example. Particle tracking is applied to demonstrate the validity of this scheme

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)

Commemoration of a cold war

DEFF Research Database (Denmark)

Farbøl, Rosanna

2015-01-01

This article brings together the fields of Cold War studies and memory studies. In Denmark, a remarkable institutionalisation of Cold War memory has taken place in the midst of a heated ideological battle over the past and whether to remember the Cold War as a ‘war’. Using Danish Cold War museums...... and heritage sites as case studies, this article sheds new light on the politics of history involved in Cold War commemoration. It suggests that the Cold War is commemorated as a war, yet this war memory is of a particular kind: it is a war memory without victims....

The Hi-Ring DCN Architecture

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...

Cold vacuum chamber for diagnostics: Analysis of the measurements at the Diamond Light Source and impedance bench measurements

Science.gov (United States)

Voutta, R.; Gerstl, S.; Casalbuoni, S.; Grau, A. W.; Holubek, T.; Saez de Jauregui, D.; Bartolini, R.; Cox, M. P.; Longhi, E. C.; Rehm, G.; Schouten, J. C.; Walker, R. P.; Migliorati, M.; Spataro, B.

2016-05-01

The beam heat load is an important input parameter needed for the cryogenic design of superconducting insertion devices. Theoretical models taking into account the different heating mechanisms of an electron beam to a cold bore predict smaller values than the ones measured with several superconducting insertion devices installed in different electron storage rings. In order to measure and possibly understand the beam heat load to a cold bore, a cold vacuum chamber for diagnostics (COLDDIAG) has been built. COLDDIAG is equipped with temperature sensors, pressure gauges, mass spectrometers as well as retarding field analyzers which allow to measure the beam heat load, total pressure, and gas content as well as the flux of particles hitting the chamber walls. COLDDIAG was installed in a straight section of the Diamond Light Source (DLS). In a previous paper the experimental equipment as well as the installation of COLDDIAG in the DLS are described [S. Gerstl et al., Phys. Rev. ST Accel. Beams 17, 103201 (2014)]. In this paper we present an overview of all the measurements performed with COLDDIAG at the DLS and their detailed analysis, as well as impedance bench measurements of the cold beam vacuum chamber performed at the Karlsruhe Institute of Technology after removal from the DLS. Relevant conclusions for the cryogenic design of superconducting insertion devices are drawn from the obtained results.

Cold vacuum chamber for diagnostics: Analysis of the measurements at the Diamond Light Source and impedance bench measurements

Directory of Open Access Journals (Sweden)

R. Voutta

2016-05-01

Full Text Available The beam heat load is an important input parameter needed for the cryogenic design of superconducting insertion devices. Theoretical models taking into account the different heating mechanisms of an electron beam to a cold bore predict smaller values than the ones measured with several superconducting insertion devices installed in different electron storage rings. In order to measure and possibly understand the beam heat load to a cold bore, a cold vacuum chamber for diagnostics (COLDDIAG has been built. COLDDIAG is equipped with temperature sensors, pressure gauges, mass spectrometers as well as retarding field analyzers which allow to measure the beam heat load, total pressure, and gas content as well as the flux of particles hitting the chamber walls. COLDDIAG was installed in a straight section of the Diamond Light Source (DLS. In a previous paper the experimental equipment as well as the installation of COLDDIAG in the DLS are described [S. Gerstl et al., Phys. Rev. ST Accel. Beams 17, 103201 (2014]. In this paper we present an overview of all the measurements performed with COLDDIAG at the DLS and their detailed analysis, as well as impedance bench measurements of the cold beam vacuum chamber performed at the Karlsruhe Institute of Technology after removal from the DLS. Relevant conclusions for the cryogenic design of superconducting insertion devices are drawn from the obtained results.

Cold thermal injury from cold caps used for the prevention of chemotherapy-induced alopecia.

Science.gov (United States)

Belum, Viswanath Reddy; de Barros Silva, Giselle; Laloni, Mariana Tosello; Ciccolini, Kathryn; Goldfarb, Shari B; Norton, Larry; Sklarin, Nancy T; Lacouture, Mario E

2016-06-01

The use of scalp cooling for the prevention of chemotherapy-induced alopecia (CIA) is increasing. Cold caps are placed onto the hair-bearing areas of the scalp for varying time periods before, during, and after cytotoxic chemotherapy. Although not yet reported, improper application procedures could result in adverse events (AEs). At present, there are no evidence-based scalp cooling protocols, and there is no regulatory oversight of their use. To report the occurrence of cold thermal injury (frostbite) on the scalp, following the use of cold caps for the prevention of CIA. We identified four patients who developed cold thermal injuries on the scalp following the application of cold caps. Medical records were analyzed to retrieve the demographic and clinical characteristics. The cold thermal injuries in our patients were grade 1/2 in severity and improved with topical interventions and interruption of cold cap use, although grade 1 persistent alopecia ensued in 3 patients. The true incidence of such injuries in this setting, however, remains unknown. Cold thermal injuries are likely infrequent and preventable AEs that may result from improper device application procedures during cold cap use. Although these untoward events are usually mild to moderate in severity, the potential occurrence of long-term sequelae (e.g., permanent alopecia and scarring) or the need to discontinue cold cap use, are not known. Prospective studies are needed to further elucidate the risk and standardize healthcare delivery methods, and to improve patient/supportive/healthcare provider education.

EBT ring physics

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

Cold starting characteristics analysis of hydraulic free piston engine

International Nuclear Information System (INIS)

Zhang, Shuanlu; Zhao, Zhenfeng; Zhao, Changlu; Zhang, Fujun; Wang, Shan

2017-01-01

The cold start characteristic of hydraulic free piston diesel engine may affect its stable operation. Therefore the specific cold start characteristics, such as BDC or TDC positions, pressure in-cylinder, heat release rate, should be investigated in detail. These parameters fluctuate in some regularity in the cod start process. With the development of the free piston engine prototype and the establishment of test bench, the results are obtained. For the dynamic results, the fluctuation range of TDC and BDC positions is 8 mm and decreases with time. The thermodynamic results show that the combustion process is not stable and the pressure in-cylinder fluctuates largely in the cold start process. In addition, the combustion is rapid and knock happens inevitably. In order to investigate the reasons, a CFD model is established for temperature analysis in-cylinder and heat transfer conditions. It is found that higher start wall temperature will lead to more uniform temperature distribution. The delay period may decreases and heat release will move forward. This reason is analyzed by thermodynamic derivation based on the first law of thermodynamics. Finally, the improvement suggestions of cold start strategy are proposed. - Highlights: • The cold start behaviors of HFPE are investigated in detail. • CFD method is used for simulating temperature distribution in start process. • Thermodynamic derivation uncovers the compression temperature distribution. • The improvement suggestions of cold start strategy are proposed.

Late summer temperature reconstruction based on tree-ring density for Sygera Mountain, southeastern Tibetan Plateau

Science.gov (United States)

Li, Mingyong; Duan, Jianping; Wang, Lily; Zhu, Haifeng

2018-04-01

Although several tree-ring density-based summer/late summer temperature reconstructions have been developed on the Tibetan Plateau (TP), the understanding of the local/regional characteristics of summer temperature fluctuations on a long-term scale in some regions is still limited. To improve our understanding in these aspects, more local or regional summer temperature reconstructions extending back over several centuries are required. In this study, a new mean latewood density (LWD) chronology from Abies georgei var. smithii from the upper tree line of Sygera Mountain on the southeastern TP was developed to reconstruct the late summer temperature variability since 1820 CE. The bootstrapped correlation analysis showed that the LWD chronology index was significantly and positively correlated with the late summer (August-September) mean temperatures (r1950-2008 = 0.63, p < 0.001) recorded at the nearest meteorological station and that this reconstruction has considerable potential to represent the late summer temperature variability at the regional scale. Our late summer temperature reconstruction revealed three obvious cold periods (i.e., 1872-1908, 1913-1937 and 1941-1966) and two relatively warm phases (i.e., 1821-1871 and 1970-2008) over the past two centuries. Comparisons of our reconstruction with other independent tree-ring-based temperature reconstructions, glacier fluctuations and historical documental records from neighboring regions showed good agreement in these relatively cold and warm intervals. Our reconstruction exhibits an overall increasing temperature trend since the 1960s, providing new evidence supporting the recent warming of the TP. Moreover, our results also indicate that the late summer temperature variability of Sygera Mountain on the southeastern TP has potential links with the Pacific Decadal Oscillation (PDO).

A Computer Vision Approach to Identify Einstein Rings and Arcs

Science.gov (United States)

Lee, Chien-Hsiu

2017-03-01

Einstein rings are rare gems of strong lensing phenomena; the ring images can be used to probe the underlying lens gravitational potential at every position angles, tightly constraining the lens mass profile. In addition, the magnified images also enable us to probe high-z galaxies with enhanced resolution and signal-to-noise ratios. However, only a handful of Einstein rings have been reported, either from serendipitous discoveries or or visual inspections of hundred thousands of massive galaxies or galaxy clusters. In the era of large sky surveys, an automated approach to identify ring pattern in the big data to come is in high demand. Here, we present an Einstein ring recognition approach based on computer vision techniques. The workhorse is the circle Hough transform that recognise circular patterns or arcs in the images. We propose a two-tier approach by first pre-selecting massive galaxies associated with multiple blue objects as possible lens, than use Hough transform to identify circular pattern. As a proof-of-concept, we apply our approach to SDSS, with a high completeness, albeit with low purity. We also apply our approach to other lenses in DES, HSC-SSP, and UltraVISTA survey, illustrating the versatility of our approach.

Compartmental transport model of microbicide delivery by an intravaginal ring

Science.gov (United States)

Geonnotti, Anthony R.; Katz, David F.

2010-01-01

Topical antimicrobials, or microbicides, are being developed to prevent HIV transmission through local, mucosal delivery of antiviral compounds. While hydrogel vehicles deliver the majority of current microbicide products, intravaginal rings (IVRs) are an alternative microbicide modality in preclinical development. IVRs provide a long-term dosing alternative to hydrogel use, and might provide improved user adherence. IVR efficacy requires sustained delivery of antiviral compounds to the entire vaginal compartment. A two-dimensional, compartmental vaginal drug transport model was created to evaluate the delivery of drugs from an intravaginal ring. The model utilized MRI-derived ring geometry and location, experimentally defined ring fluxes and vaginal fluid velocities, and biophysically relevant transport theory. Model outputs indicated the presence of potentially inhibitory concentrations of antiviral compounds along the entire vaginal canal within 24 hours following IVR insertion. Distributions of inhibitory concentrations of antiviral compounds were substantially influenced by vaginal fluid flow and production, while showing little change due to changes in diffusion coefficients or ring fluxes. Additionally, model results were predictive of in vivo concentrations obtained in clinical trials. Overall, this analysis initiates a mechanistic computational framework, heretofore missing, to understand and evaluate the potential of IVRs for effective delivery of antiviral compounds. PMID:20222027

Ground Movement in SSRL Ring

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.

Two pyrazine derivatives as inhibitors of the cold rolled steel corrosion in hydrochloric acid solution

Energy Technology Data Exchange (ETDEWEB)

Deng Shuduan, E-mail: dengshuduan@163.co [Faculty of Wood Science and Decoration Technology, Southwest Forestry University, Kunming 650224 (China); Li Xianghong; Fu Hui [Department of Fundamental Courses, Southwest Forestry University, Kunming 650224 (China)

2011-02-15

Research highlights: Two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) are good inhibitors for the corrosion of steel in 1.0 M HCl solution. The inhibition efficiency follows the order: ABP > AP. The substitution Br of ABP is the additional centre of adsorption and increases the electron density of pyrazine ring, which can facilitate its adsorption on the metal surface. For either ABP or AP, the adsorption obeys Langmuir adsorption isotherm. Both ABP and AP act as mixed-type inhibitors. - Abstract: The inhibition effect of two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was studied by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that both AP and ABP are good inhibitors, and inhibition efficiency follows the order: ABP > AP. The adsorption of each inhibitor on CRS surface obeys Langmuir adsorption isotherm. Potentiodynamic polarization curves show that two pyrazine derivatives act as mixed-type inhibitors. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability.

Two pyrazine derivatives as inhibitors of the cold rolled steel corrosion in hydrochloric acid solution

International Nuclear Information System (INIS)

Deng Shuduan; Li Xianghong; Fu Hui

2011-01-01

Research highlights: → Two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) are good inhibitors for the corrosion of steel in 1.0 M HCl solution. → The inhibition efficiency follows the order: ABP > AP. The substitution Br of ABP is the additional centre of adsorption and increases the electron density of pyrazine ring, which can facilitate its adsorption on the metal surface. → For either ABP or AP, the adsorption obeys Langmuir adsorption isotherm. → Both ABP and AP act as mixed-type inhibitors. - Abstract: The inhibition effect of two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was studied by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that both AP and ABP are good inhibitors, and inhibition efficiency follows the order: ABP > AP. The adsorption of each inhibitor on CRS surface obeys Langmuir adsorption isotherm. Potentiodynamic polarization curves show that two pyrazine derivatives act as mixed-type inhibitors. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability.

Changes in ventricular function during emotional stress and cold exposure

International Nuclear Information System (INIS)

Kiess, M.C.; Moore, R.A.; Dimsdale, J.; Alpert, N.M.; Boucher, C.A.; Strauss, H.W.

1984-01-01

Patients with cardiac disease frequently develop symptoms with emotional stress or cold exposure. To investigate the effects of these stresses in normal subjects, an ambulatory ventricular function monitor (VEST) (previously reported to measure EFs which correlate well with gamma camera measurements) was employed to record sequential 2 minute time activity curves from the left ventricles of 6 healthy men (ages 19-24) during a control period and during a 30 minute stress interview with a psychiatrist. Four of the subjects were also monitored in a cold room (1 0 C) for 20 min. In addition to the left ventricular time-activity curve, heart rate (HR), and BP (cuff) were recorded. All subjects had increases in HR, BP and EF during the stress interview. Cold, however, produced decreases in HR and EF and an increase in BP. The results (mean +- SD) are tabulated. End-systolic and end-diastolic counts and hence volume decreased during the interview and increased during cold exposure. The results suggest that (1) ambulatory changes in ventricular function can be measured with the VEST, and (2) significant changes in cardiovascular physiology are seen in normal subjects during a stress interview and exposure to cold

Token ring technology report

CERN Document Server

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.

Cold urticaria: inhibition of cold-induced histamine release by doxantrazole.

Science.gov (United States)

Bentley-Phillips, C B; Eady, R A; Greaves, M W

1978-10-01

Thirteen patients with cold urticaria were studied to assess the effect of the systemic drug doxantrazole, which has actions resembling disodium cromoglycate, on cold evoked histamine release. The patients, all of whom developed an immediate local whealing response after cooling of the forearm, demonstrated release of histamine into venous blood draining that forearm. Following doxantrazole treatment, significant suppression of histamine release occurred. In some but not all patients this was accompanied by diminution of urtication in response to cooling. A double-blind study was carried out in 3 subjects, all of whom showed diminished cold-stimulated histamine release after doxantrazole. Two of these showed clinical improvement. Doxantrazole had no effect on erythema due to intradermal histamine, but did suppress the erythematous reaction to intradermal injection of compound 48/80. Our results suggest that doxantrazole or related anti-allergic agents might be useful in the treatment of cold urticaria.

Performance of the advanced cold neutron source and optics upgrades at the NIST Research Reactor

International Nuclear Information System (INIS)

Williams, R.E.; Kopetka, P.; Cook, J.C.; Rowe, J.M.

2003-01-01

On March 6, 2002, the NIST Research Reactor resumed routine operation following a six-month shutdown for facility upgrades and maintenance. During the shutdown, the original liquid hydrogen cold neutron source was removed, and the advanced cold source was installed. An optical filter was installed on one of the neutron guides, NG-3, replacing a crystal filter for the 30-m SANS instrument and the guide used between the chopper disks of the Disk Chopper time-of-flight Spectrometer (DCS) installed on NG-4 has been recently reconfigured. Additional improvements in the neutron optics of various instruments are being made. The advanced liquid hydrogen cold neutron source performs as expected, nearly doubling the flux available to most instruments. The measured gains range from about 1.4 at 2 A, to over a factor of two at 15 A. Also as expected, the heat load in the new source increased to 1200 watts, but the previously existing refrigerator has easily accommodated the increase. With intensity gains of a factor of two in the important long wavelength region of the spectrum, the advanced cold source significantly enhances the measurement capability of the cold neutron scattering instrumentation at NIST. The optical filter on NG-3 is also very successful; the 30-m SANS has an additional gain of two at 17 A. A system of refracting lenses and prisms near the SANS sample position has made possible measurements at low Q (0.0005 A -1 ) that were previously not feasible. The DCS has also seen additional intensity gain factors in excess of two for the majority of experiments and at short neutron wavelengths the gains exceed three. In addition, two new triple axis spectrometers will feature double-focusing monochromators in order to exploit the full size of the available thermal and cold neutron beam tubes. The success of the advanced cold source and enhanced neutron optics contributed to the recognition of the NIST Center for Neutron Research as 'the premiere neutron scattering

77 FR 43117 - Meeting of the Cold War Advisory Committee for the Cold War Theme Study

Science.gov (United States)

2012-07-23

... the Cold War Advisory Committee for the Cold War Theme Study AGENCY: National Park Service, Interior... Committee Act, 5 U.S.C. Appendix, that the Cold War Advisory Committee for the Cold War Theme Study will... National Park Service (NPS) concerning the Cold War Theme Study. DATES: The teleconference meeting will be...

Design of a quasi-isochronous storage ring for THz light source

International Nuclear Information System (INIS)

Zhu Jiapeng; Xu Hongliang; Feng Guangyao; Lan Jieqin

2012-01-01

A quasi-isochronous storage ring is designed by manipulating lattice parameters to introduce a negative dispersion function to the dispersion section. This quasi-isochronous storage ring is designed for a THz synchrotron radiation source. The simulation of the optics function and beam emittance shows its feasibility, and the tracing result of particles indicates that the designed ring has a good particle dynamic aperture. In addition, a three-dimensional model of the vacuum chamber used for photon radiation in the quasi-isochronous mode is also designed. The eigenmodes of the chamber are simulated, and characteristic parameters such as quality factor, power loss and characteristic impedance are also calculated. The result shows that the vacuum chamber has little effect on the circulating beam. (authors)

Helium/solid powder O-ring leakage correlation experiments using a radiotracer

International Nuclear Information System (INIS)

Bild, R.W.; Leisher, W.B.; Weissman, S.H.; Seya, M.

1984-01-01

UO 2 definitely leaked past the O-ring in three of the tests confirming the major results of the previous work. Continuous leakage at these levels may require additional precautions under present regulatory policies. The mechanism and the time and particle size dependence for the leakage are not known, but there is some indication leakage is more likely at low temperatures. It is possible leakage is due to movement of the O-ring during temperature or pressure cycling at the beginning or end of a test. The radiotracer method involves less labor and is much less susceptible to contamination than the previous method. Future work will investigate leakage past lubricated O-rings and time dependence of leakage. 1 reference, 1 table

Prototype moving-ring reactor

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

Researches on the Piston Ring

Science.gov (United States)

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

Outer crust of nonaccreting cold neutron stars

International Nuclear Information System (INIS)

Ruester, Stefan B.; Hempel, Matthias; Schaffner-Bielich, Juergen

2006-01-01

The properties of the outer crust of nonaccreting cold neutron stars are studied by using modern nuclear data and theoretical mass tables, updating in particular the classic work of Baym, Pethick, and Sutherland. Experimental data from the atomic mass table from Audi, Wapstra, and Thibault of 2003 are used and a thorough comparison of many modern theoretical nuclear models, both relativistic and nonrelativistic, is performed for the first time. In addition, the influences of pairing and deformation are investigated. State-of-the-art theoretical nuclear mass tables are compared to check their differences concerning the neutron drip line, magic neutron numbers, the equation of state, and the sequence of neutron-rich nuclei up to the drip line in the outer crust of nonaccreting cold neutron stars

Probing the Cold Dust Emission in the AB Aur Disk: A Dust Trap in a Decaying Vortex?

Science.gov (United States)

Fuente, Asunción; Baruteau, Clément; Neri, Roberto; Carmona, Andrés; Agúndez, Marcelino; Goicoechea, Javier R; Bachiller, Rafael; Cernicharo, José; Berné, Olivier

2017-09-01

One serious challenge for planet formation is the rapid inward drift of pebble-sized dust particles in protoplanetary disks. Dust trapping at local maxima in the disk gas pressure has received much theoretical attention but still lacks observational support. The cold dust emission in the AB Aur disk forms an asymmetric ring at a radius of about 120 au, which is suggestive of dust trapping in a gas vortex. We present high spatial resolution (0".58×0".78 ≈ 80×110 au) NOEMA observations of the 1.12 mm and 2.22 mm dust continuum emission from the AB Aur disk. Significant azimuthal variations of the flux ratio at both wavelengths indicate a size segregation of the large dust particles along the ring. Our continuum images also show that the intensity variations along the ring are smaller at 2.22 mm than at 1.12 mm, contrary to what dust trapping models with a gas vortex have predicted. Our two-fluid (gas+dust) hydrodynamical simulations demonstrate that this feature is well explained if the gas vortex has started to decay due to turbulent diffusion, and dust particles are thus losing the azimuthal trapping on different timescales depending on their size. The comparison between our observations and simulations allows us to constrain the size distribution and the total mass of solid particles in the ring, which we find to be of the order of 30 Earth masses, enough to form future rocky planets.

Probing the Cold Dust Emission in the AB Aur Disk: A Dust Trap in a Decaying Vortex?

Energy Technology Data Exchange (ETDEWEB)

Fuente, Asunción; Bachiller, Rafael [Observatorio Astronómico Nacional (OAN, IGN), Apdo 112, E-28803 Alcalá de Henares (Spain); Baruteau, Clément; Carmona, Andrés; Berné, Olivier [IRAP, Université de Toulouse, CNRS, UPS, Toulouse (France); Neri, Roberto [Institut de Radioastronomie Millimétrique (IRAM), 300 rue de la Piscine, F-38406 Saint Martin d’Hères (France); Agúndez, Marcelino; Goicoechea, Javier R.; Cernicharo, José, E-mail: a.fuente@oan.es [Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), E-28049 Cantoblanco, Madrid (Spain)

2017-09-01

One serious challenge for planet formation is the rapid inward drift of pebble-sized dust particles in protoplanetary disks. Dust trapping at local maxima in the disk gas pressure has received much theoretical attention but still lacks observational support. The cold dust emission in the AB Aur disk forms an asymmetric ring at a radius of about 120 au, which is suggestive of dust trapping in a gas vortex. We present high spatial resolution (0.″58 × 0.″78 ≈ 80 × 110 au) NOEMA observations of the 1.12 mm and 2.22 mm dust continuum emission from the AB Aur disk. Significant azimuthal variations of the flux ratio at both wavelengths indicate a size segregation of the large dust particles along the ring. Our continuum images also show that the intensity variations along the ring are smaller at 2.22 mm than at 1.12 mm, contrary to what dust trapping models with a gas vortex have predicted. Our two-fluid (gas+dust) hydrodynamical simulations demonstrate that this feature is well explained if the gas vortex has started to decay due to turbulent diffusion, and dust particles are thus losing the azimuthal trapping on different timescales depending on their size. The comparison between our observations and simulations allows us to constrain the size distribution and the total mass of solid particles in the ring, which we find to be of the order of 30 Earth masses, enough to form future rocky planets.

Development of Cold Neutron Activation Station at HANARO Cold Neutron Source

International Nuclear Information System (INIS)

Sun, G. M.; Hoang, S. M. T.; Moon, J. H.; Chung, Y. S.; Cho, S. J.; Lee, K. H.; Park, B. G.; Choi, H. D.

2012-01-01

A new cold neutron source at the HANARO Research Reactor had been constructed in the framework of a five-year project, and ended in 2009. It has seven neutron guides, among which five guides were already allocated for a number of neutron scattering instruments. A new two-year project to develop a Cold Neutron Activation Station (CONAS) was carried out at the two neutron guides since May 2010, which was supported by the program of the Ministry of Education, Science and Technology, Korea. Fig. 1 shows the location of CONAS. CONAS is a complex facility including several radioanalytical instruments utilizing neutron capture reaction to analyze elements in a sample. It was designed to include three instruments like a CN-PGAA (Cold Neutron - Prompt Gamma Activation Analysis), a CN-NIPS (Cold Neutron - Neutron Induced Pair Spectrometer), and a CN-NDP (Cold Neutron - Neutron-induced prompt charged particle Depth Profiling). Fig. 2 shows the conceptual configuration of the CONAS concrete bioshield and the instruments. CN-PGAA and CN-NIPS measure the gamma-rays promptly emitted from the sample after neutron capture, whereas CN-NDP is a probe to measure the charged particles emitted from the sample surface after neutron capture. For this, we constructed two cold neutron guides called CG1 and CG2B guides from the CNS

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)

Low grade mosaic for a complex supernumerary ring chromosome 18 in an adult patient with multiple congenital anomalies

Directory of Open Access Journals (Sweden)

Hoogeboom A Jeannette M

2010-07-01

Full Text Available Abstract Background Several cases have been reported of patients with a ring chromosome 18 replacing one of the normal chromosomes 18. Less common are patients with a supernumerary ring chromosomes 18. High resolution whole genome examination in patients with multiple congenital abnormalities might reveal cytogenetic abnormalities of an unexpected complexity. Results We report a 24 years old male patient with lower spinal anomalies, hypospadia, bifid scrotum, cryptorchism, anal atresia, kidney stones, urethra anomalies, radial dysplasia, and a hypoplastic thumb. Some of the anomalies overlap with the VACTERL association. Chromosome analysis of cultured peripheral blood lymphocytes revealed an additional ring chromosome in 13% of the metaphases. Both parents had a normal karyotype, demonstrating the de novo origin of this ring chromosome. FISH analysis using whole chromosome paints showed that the additional chromosomal material was derived from chromosome 18. Chromosome analysis of cultured fibroblasts revealed only one cell with the supernumerary ring chromosome in the 400 analyzed. To characterize the ring chromosome in more detail peripheral blood derived DNA was analyzed using SNP-arrays. The array results indicated a 5 Mb gain of the pericentromeric region of chromosome 18q10-q11.2. FISH analysis using BAC-probes located in the region indicated the presence of 6 signals on the r(18 chromosome. In addition, microsatellite analysis demonstrated that the unique supernumerary ring chromosome was paternally derived and both normal copies showed biparental disomy. Conclusions We report on an adult patient with multiple congenital abnormalities who had in 13% of his cells a unique supernumerary ring chromosome 18 that was composed of 6 copies of the 5 Mb gene rich region of 18q11.

Support for cold neutron utilization

International Nuclear Information System (INIS)

Lee, Kye Hong; Han, Young Soo; Choi, Sungmin; Choi, Yong; Kwon, Hoon; Lee, Kwang Hee

2012-06-01

- Support for experiments by users of cold neutron scattering instrument - Short-term training of current and potential users of cold neutron scattering instrument for their effective use of the instrument - International collaboration for advanced utilization of cold neutron scattering instruments - Selection and training of qualified instrument scientists for vigorous research endeavors and outstanding achievements in experiments with cold neutron - Research on nano/bio materials using cold neutron scattering instruments - Bulk nano structure measurement using small angle neutron scattering and development of analysis technique

"Ring" in the solo child singing voice.

Science.gov (United States)

Howard, David M; Williams, Jenevora; Herbst, Christian T

2014-03-01

Listeners often describe the voices of solo child singers as being "pure" or "clear"; these terms would suggest that the voice is not only pleasant but also clearly audible. The audibility or clarity could be attributed to the presence of high-frequency partials in the sound: a "brightness" or "ring." This article aims to investigate spectrally the acoustic nature of this ring phenomenon in children's solo voices, and in particular, relating it to their "nonring" production. Additionally, this is set in the context of establishing to what extent, if any, the spectral characteristics of ring are shared with those of the singer's formant cluster associated with professional adult opera singers in the 2.5-3.5kHz region. A group of child solo singers, acknowledged as outstanding by a singing teacher who specializes in teaching professional child singers, were recorded in a major UK concert hall performing Come unto him, all ye that labour, from the aria He shall feed his flock from The Messiah by GF Handel. Their singing was accompanied by a recording of a piano played through in-ear headphones. Sound pressure recordings were made from well within the critical distance in the hall. The singers were observed to produce notes with and without ring, and these recordings were analyzed in the frequency domain to investigate their spectra. The results indicate that there is evidence to suggest that ring in child solo singers is carried in two areas of the output spectrum: first in the singer's formant cluster region, centered around 4kHz, which is more than 1000Hz higher than what is observed in adults; and second in the region around 7.5-11kHz where a significant strengthening of harmonic presence is observed. A perceptual test has been carried out demonstrating that 94% of 62 listeners label a synthesized version of the calculated overall average ring spectrum for all subjects as having ring when compared with a synthesized version of the calculated overall average nonring

Utilizing wheel-ring architecture for stable and selectable single-longitudinal-mode erbium fiber laser

Science.gov (United States)

Yeh, Chien-Hung; Yang, Zi-Qing; Huang, Tzu-Jung; Chow, Chi-Wai

2018-03-01

To achieve a steady single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser, the wheel-ring architecture is proposed in the laser cavity. According to Vernier effect, the proposed wheel-ring can produce three different free spectrum ranges (FSRs) to serve as the mode-filter for suppressing the densely multi-longitudinal-mode (MLM). Here, to complete wavelength-tunable EDF laser, an optical tunable bandpass filter (OTBF) is utilized inside the cavity for tuning arbitrarily. In addition, the entire output performances of the proposed EDF wheel-ring laser are also discussed and analyzed experimentally.

Computational study of hydrogen shifts and ring-opening mechanisms in α-pinene ozonolysis products

DEFF Research Database (Denmark)

Kurtén, Theo; Rissanen, Matti P.; Mackeprang, Kasper

2015-01-01

, sterically unhindered) H-shifts of all four peroxy radicals formed in the ozonolysis of α-pinene using density functional (ωB97XD) and coupled cluster [CCSD(T)-F12] theory. In contrast to the related but chemically simpler cyclohexene ozonolysis system, none of the calculated H-shifts have rate constants...... products in the α-pinene ozonolysis system, additional ring-opening reaction mechanisms breaking the cyclobutyl ring are therefore needed. We further investigate possible uni- and bimolecular pathways for opening the cyclobutyl ring in the α-pinene ozonolysis system....

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

Studies on the friction and wear properties of synchronizer rings and gear cones; Shinkuro kiko ni okeru masatsu mamo tokusei ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Hayashi, K; Kunoki, T [COSMO Research Institute, Tokyo (Japan)

1997-10-01

The influence of materials of synchronizer rings, automotive gear oils and sulfur-phosphorus EP additives on the friction and wear properties of synchromesh system was studied by using a synchromesh friction tester. As a result, the durability was decreased by using the synchronizer ring made of copper alloys. The initial friction performance estimated by using the synchronizer ring made of resin have influence on EP additives, in particular some kinds of phosphorus type additives. 3 refs., 12 figs.

Morphological evolution of Ge/Si(001) quantum dot rings formed at the rim of wet-etched pits.

Science.gov (United States)

Grydlik, Martyna; Brehm, Moritz; Schäffler, Friedrich

2012-10-30

We demonstrate the formation of Ge quantum dots in ring-like arrangements around predefined {111}-faceted pits in the Si(001) substrate. We report on the complex morphological evolution of the single quantum dots contributing to the rings by means of atomic force microscopy and demonstrate that by careful adjustment of the epitaxial growth parameters, such rings containing densely squeezed islands can be grown with large spatial distances of up to 5 μm without additional nucleation of randomly distributed quantum dots between the rings.

THE IBEX RIBBON AND THE PICKUP ION RING STABILITY IN THE OUTER HELIOSHEATH. II. MONTE-CARLO AND PARTICLE-IN-CELL MODEL RESULTS

Energy Technology Data Exchange (ETDEWEB)

Niemiec, J. [Institute of Nuclear Physics PAN, Radzikowskiego 152 31-342 Krakow (Poland); Florinski, V.; Heerikhuisen, J. [Department of Space Science and Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Nishikawa, K.-I., E-mail: jacek.niemiec@ifj.edu.pl, E-mail: vaf0001@uah.edu, E-mail: jh0004@uah.edu, E-mail: ken-ichi.nishikawa-1@nasa.gov [Department of Physics, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

2016-08-01

The nearly circular ribbon of energetic neutral atom (ENA) emission discovered by NASA’s Interplanetary Boundary EXplorer satellite ( IBEX ), is most commonly attributed to the effect of charge exchange of secondary pickup ions (PUIs) gyrating about the magnetic field in the outer heliosheath (OHS) and the interstellar space beyond. The first paper in the series (Paper I) presented a theoretical analysis of the pickup process in the OHS and hybrid-kinetic simulations, revealing that the kinetic properties of freshly injected proton rings depend sensitively on the details of their velocity distribution. It was demonstrated that only rings that are not too narrow (parallel thermal spread above a few km s{sup −1}) and not too wide (parallel temperature smaller than the core plasma temperature) could remain stable for a period of time long enough to generate ribbon ENAs. This paper investigates the role of electron dynamics and the extra spatial degree of freedom in the ring ion scattering process with the help of two-dimensional full particle-in-cell (PIC) kinetic simulations. A good agreement is observed between ring evolution under unstable conditions in hybrid and PIC models, and the dominant modes are found to propagate parallel to the magnetic field. We also present more realistic ribbon PUI distributions generated using Monte Carlo simulations of atomic hydrogen in the global heliosphere and examine the effect of both the cold ring-like and the hot “halo” PUIs produced from heliosheath ENAs on the ring stability. It is shown that the second PUI population enhances the fluctuation growth rate, leading to faster isotropization of the solar-wind-derived ring ions.

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

Fundamental Design Principles of Linear Collider Damping Rings, with an Application to CLIC

CERN Document Server

Potier, J P

2000-01-01

Damping Rings for Linear Colliders have to produce very small normalised emittances at a high repetition rate. A previous paper presented analytical expressions for the equilibrium emittance of an arc cell as a function of the deflection angle per dipole. In addition, an expression for the lattice parameters providing the minimum emittance, and a strategy to stay close to this, were proposed. This analytical approach is extended to the detailed design of Damping Rings, taking into account the straight sections and the damping wigglers. Complete rings, including wiggler and injection insections, were modelled with the MAD [1] program, and their performance was found to be in good agreement with the analytical calculation. With such an approach it is shown that a Damping Ring corresponding to the Compact Linear Collider (CLIC) parameters at 0.5 and 1 TeV centre-of-mass energy, and tunable for two different sets of emittance and injection repetition rate, can be designed using the same ring layout.

Commissioning of the Cryogenic Plant for the Cryogenic Storage Ring (CSR) at Heidelberg

CERN Document Server

von Hahn, R; Grieser, M; Haberstroh, C; Kaiser, D; Lange, M; Laux, F; Menk, S; Orlov, D A; Repnow, R; Sieber, T; Quack, H; Varju, J; Wolf A

2009-01-01

At the Max-Planck-Institute for Nuclear Physics in Heidelberg a next generation electrostatic storage ring for low velocity atomic and molecular ion beams is under construction. In contrast to existing electrostatic storage rings, the Cryogenic Storage Ring CSR will be cooled down to temperatures below 2 K. Thus acting as a large cryopump it will provide long storage times and, in addition, open a new field of quantum state controlled molecular physics due to a low heat radiation background from space-like environment. A concept for cooling the storage ring has been developed and is presently tested by means of a linear trap as a prototype with a length of 1/10 of the planned ring. A commercial refrigerator with 21 W at 2 K has been successfully commissioned and was connected to the prototype. This paper presents the status of the cryogenic plant after the commissioning and one year of operation.

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...

Microstructure Evolution During Creep of Cold Worked Austenitic Stainless Steel

Science.gov (United States)

Krishan Yadav, Hari; Ballal, A. R.; Thawre, M. M.; Vijayanand, V. D.

2018-04-01

The 14Cr–15Ni austenitic stainless steel (SS) with additions of Ti, Si, and P has been developed for their superior creep strength and better resistance to void swelling during service as nuclear fuel clad and wrapper material. Cold working induces defects such as dislocations that interact with point defects generated by neutron irradiation and facilitates recombination to make the material more resistant to void swelling. In present investigation, creep properties of the SS in mill annealed condition (CW0) and 40 % cold worked (CW4) condition were studied. D9I stainless steel was solution treated at 1333 K for 30 minutes followed by cold rolling. Uniaxial creep tests were performed at 973 K for various stress levels ranging from 175-225 MPa. CW4 samples exhibited better creep resistance as compared to CW0 samples. During creep exposure, cold worked material exhibited phenomena of recovery and recrystallization wherein new strain free grains were observed with lesser dislocation network. In contrast CW0 samples showed no signs of recovery and recrystallization after creep exposure. Partial recrystallization on creep exposure led to higher drop in hardness in cold worked sample as compared to that in mill annealed sample. Accelerated precipitation of carbides at the grain boundaries was observed during creep exposure and this phenomenon was more pronounced in cold worked sample.

Carotenoid β-Ring Hydroxylase and Ketolase from Marine Bacteria—Promiscuous Enzymes for Synthesizing Functional Xanthophylls

OpenAIRE

Misawa, Norihiko

2011-01-01

Marine bacteria belonging to genera Paracoccus and Brevundimonas of the α-Proteobacteria class can produce C40-type dicyclic carotenoids containing two β-end groups (β rings) that are modified with keto and hydroxyl groups. These bacteria produce astaxanthin, adonixanthin, and their derivatives, which are ketolated by carotenoid β-ring 4(4′)-ketolase (4(4′)-oxygenase; CrtW) and hydroxylated by carotenoid β-ring 3(3′)-hydroxylase (CrtZ). In addition, the genus Brevundimonas possesses a gene fo...

A tree-ring perspective on the terrestrial carbon cycle

International Nuclear Information System (INIS)

Babst, F.; Alexander, M.R.; Szejner, P.; Trouet, V.; Alexander, M.R.; Moore, D.J.P.; Bouriaud, O.; Klesse, S.; Frank, D.; Roden, J.; Ciais, P.; Poulter, B.

2014-01-01

Tree-ring records can provide valuable information to advance our understanding of contemporary terrestrial carbon cycling and to reconstruct key metrics in the decades preceding monitoring data. The growing use of tree rings in carbon-cycle research is being facilitated by increasing recognition of reciprocal benefits among research communities. Yet, basic questions persist regarding what tree rings represent at the ecosystem level, how to optimally integrate them with other data streams, and what related challenges need to be overcome. It is also apparent that considerable unexplored potential exists for tree rings to refine assessments of terrestrial carbon cycling across a range of temporal and spatial domains. Here, we summarize recent advances and highlight promising paths of investigation with respect to (1) growth phenology, (2) forest productivity trends and variability, (3) CO 2 fertilization and water-use efficiency, (4) forest disturbances, and (5) comparisons between observational and computational forest productivity estimates. We encourage the integration of tree-ring data: with eddy-covariance measurements to investigate carbon allocation patterns and water-use efficiency; with remotely sensed observations to distinguish the timing of cambial growth and leaf phenology; and with forest inventories to develop continuous, annually resolved and long-term carbon budgets. In addition, we note the potential of tree-ring records and derivatives thereof to help evaluate the performance of earth system models regarding the simulated magnitude and dynamics of forest carbon uptake, and inform these models about growth responses to (non-)climatic drivers. Such efforts are expected to improve our understanding of forest carbon cycling and place current developments into a long-term perspective. (authors)

Neurosensory sequelae assessed by thermal and vibrotactile perception thresholds after local cold injury.

Science.gov (United States)

Carlsson, Daniel; Burström, Lage; Lilliesköld, Victoria Heldestad; Nilsson, Tohr; Nordh, Erik; Wahlström, Jens

2014-01-01

Local freezing cold injuries are common in the north and sequelae to cold injury can persist many years. Quantitative sensory testing (QST) can be used to assess neurosensory symptoms but has previously not been used on cold injury patients. To evaluate neurosensory sequelae after local freezing cold injury by thermal and vibrotactile perception thresholds and by symptom descriptions. Fifteen patients with a local freezing cold injury in the hands or feet, acquired during military training, were studied with QST by assessment of vibrotactile (VPT), warmth (WPT) and cold (CPT) perception thresholds 4 months post-injury. In addition, a follow-up questionnaire, focusing on neurovascular symptoms, was completed 4 months and 4 years post-injury. QST demonstrated abnormal findings in one or both affected hands for VPT in 6 patients, for WPT in 4 patients and for CPT in 1 patient. In the feet, QST was abnormal for VPT in one or both affected feet in 8 patients, for WPT in 6 patients and for CPT in 4 patients. Freezing cold injury related symptoms, e.g. pain/discomfort when exposed to cold, cold sensation and white fingers were common at 4 months and persisted 4 years after the initial injury. Neurosensory sequelae after local freezing cold injury, in terms of abnormal thermal and/or vibration perception thresholds, may last at least 4 months after the initial injury. Symptoms such as pain/discomfort at cold exposure, cold sensations and white fingers may persist at least 4 years after the initial injury.

The Nav1.9 Channel Is a Key Determinant of Cold Pain Sensation and Cold Allodynia

Directory of Open Access Journals (Sweden)

Stéphane Lolignier

2015-05-01

Full Text Available Cold-triggered pain is essential to avoid prolonged exposure to harmfully low temperatures. However, the molecular basis of noxious cold sensing in mammals is still not completely understood. Here, we show that the voltage-gated Nav1.9 sodium channel is important for the perception of pain in response to noxious cold. Nav1.9 activity is upregulated in a subpopulation of damage-sensing sensory neurons responding to cooling, which allows the channel to amplify subthreshold depolarizations generated by the activation of cold transducers. Consequently, cold-triggered firing is impaired in Nav1.9−/− neurons, and Nav1.9 null mice and knockdown rats show increased cold pain thresholds. Disrupting Nav1.9 expression in rodents also alleviates cold pain hypersensitivity induced by the antineoplastic agent oxaliplatin. We conclude that Nav1.9 acts as a subthreshold amplifier in cold-sensitive nociceptive neurons and is required for the perception of cold pain under normal and pathological conditions.

Ring accelerators

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

Cold temperatures increase cold hardiness in the next generation Ophraella communa beetles.

Directory of Open Access Journals (Sweden)

Zhong-Shi Zhou

Full Text Available The leaf beetle, Ophraella communa, has been introduced to control the spread of the common ragweed, Ambrosia artemisiifolia, in China. We hypothesized that the beetle, to be able to track host-range expansion into colder climates, can phenotypically adapt to cold temperatures across generations. Therefore, we questioned whether parental experience of colder temperatures increases cold tolerance of the progeny. Specifically, we studied the demography, including development, fecundity, and survival, as well as physiological traits, including supercooling point (SCP, water content, and glycerol content of O. communa progeny whose parents were maintained at different temperature regimes. Overall, the entire immature stage decreased survival of about 0.2%-4.2% when parents experienced cold temperatures compared to control individuals obtained from parents raised at room temperature. However, intrinsic capacity for increase (r, net reproductive rate (R 0 and finite rate of increase (λ of progeny O. communa were maximum when parents experienced cold temperatures. Glycerol contents of both female and male in progeny was significantly higher when maternal and paternal adults were cold acclimated as compared to other treatments. This resulted in the supercooling point of the progeny adults being significantly lower compared to beetles emerging from parents that experienced room temperatures. These results suggest that cold hardiness of O. communa can be promoted by cold acclimation in previous generation, and it might counter-balance reduced survival in the next generation, especially when insects are tracking their host-plants into colder climates.

A HIGH FIDELITY SAMPLE OF COLD FRONT CLUSTERS FROM THE CHANDRA ARCHIVE

International Nuclear Information System (INIS)

Owers, Matt S.; Nulsen, Paul E. J.; Markevitch, Maxim; Couch, Warrick J.

2009-01-01

This paper presents a sample of 'cold front' clusters selected from the Chandra archive. The clusters are selected based purely on the existence of surface brightness edges in their Chandra images which are modeled as density jumps. A combination of the derived density and temperature jumps across the fronts is used to select nine robust examples of cold front clusters: 1ES0657 - 558, Abell 1201, Abell 1758N, MS1455.0+2232, Abell 2069, Abell 2142, Abell 2163, RXJ1720.1+2638, and Abell 3667. This sample is the subject of an ongoing study aimed at relating cold fronts to cluster merger activity, and understanding how the merging environment affects the cluster constituents. Here, temperature maps are presented along with the Chandra X-ray images. A dichotomy is found in the sample in that there exists a subsample of cold front clusters which are clearly mergers based on their X-ray morphologies, and a second subsample of clusters which harbor cold fronts, but have surprisingly relaxed X-ray morphologies, and minimal evidence for merger activity at other wavelengths. For this second subsample, the existence of a cold front provides the sole evidence for merger activity at X-ray wavelengths. We discuss how cold fronts can provide additional information which may be used to constrain merger histories, and also the possibility of using cold fronts to distinguish major and minor mergers.

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)

Improved cold neutron radiographic apparatus and method

International Nuclear Information System (INIS)

1981-01-01

An improved cold neutron radiography technique is described in which the neutron temperature is matched to the specific material to be analyzed. In addition to a beam source and detector the apparatus incorporates a cryogenic refrigerator which enables the moderator material to be cooled to a predetermined adjustable temperature below the Bragg edge temperature of the sample. (U.K.)

A possible candidate for cold dark matter

Indian Academy of Sciences (India)

This additional scalar can be a viable candidate of cold dark matter (CDM) since the stability of is achieved by the application of Z 2 symmetry on . Considering as a possible candidate of CDM, Boltzmann's equation is solved to find the freeze-out temperature and relic density of for Higgs mass 120 GeV in the scalar ...

The Rings of Saturn

Science.gov (United States)

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

PHYSIOLOGICAL AND LEUKOCYTE SUBSET RESPONSES TO EXERCISE AND COLD EXPOSURE IN COLD-ACCLIMATIZED SKATERS

Directory of Open Access Journals (Sweden)

K. Kim

2014-07-01

Full Text Available We investigated physiological responses and changes in circulating immune cells following exercise in cold and thermoneutral conditions. Participants were short track skaters (n=9 who were acclimatized to cold conditions, and inline skaters (n=10 who were not acclimatized. All skaters were young, and skating at a recreational level three days per week for at least one year. Using a cross-over design, study variables were measured during 60 min of submaximal cycling (65% ·VO2max in cold (ambient temperature: 5±1°C, relative humidity: 41±9% and thermoneutral conditions (ambient temperature: 21±1°C, relative humidity: 35±5%. Heart rate, blood lactate and tympanic temperature were measured at rest, during exercise and recovery. Plasma cortisol, calprotectin and circulating blood cell numbers were measured before and after 60 min of cold or thermoneutral conditions, and during recovery from exercise. Heart rate was lower in both groups during exercise in cold versus thermoneutral conditions (P<0.05. The increase in total leukocytes during recovery was primarily due to an increase in neutrophils in both groups. The cold-acclimatized group activated neutrophils after exercise in cold exposure, whereas the non-acclimatized group activated lymphocyte and cortisol after exercise in cold exposure. Lymphocyte subsets significantly changed in both groups over time during recovery as compared to rest. Immediately after exercise in both groups, CD16+ and CD69+ cells were elevated compared to rest or before exercise in both conditions. Acclimatization to exercise in the cold does not appear to influence exercise-induced immune changes in cold conditions, with the possible exception of neutrophils, lymphocytes and cortisol concentration.

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

Cold fusion, Alchemist's dream

International Nuclear Information System (INIS)

Clayton, E.D.

1989-09-01

In this report the following topics relating to cold fusion are discussed: muon catalysed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalysed cold fusion; vibrational mechanisms in excited states of D 2 molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D 2 fusion at low energies; fusion of deuterons into 4 He; secondary D+T fusion within the hydrogenated metal lattice; 3 He to 4 He ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of 3 He/ 4 He

Four centuries of reconstructed hydroclimatic variability for Northwestern Chihuahua, Mexico, based on tree rings

Directory of Open Access Journals (Sweden)

José Villanueva Díaz

2015-03-01

Full Text Available A Douglas-fir chronology with a length of 409 years (1600-2008 was developed for northwestern Chihuahua in Mesa de las Guacamayas, a “Natural Protected Area” known as an important nesting habitat for the thickbilled parrot (Rhynchopsitta pachyrhyncha an endangered neotropical bird. Increment cores and cross-sections from selected Douglas-fir trees (Pseudotsuga menziesii in a mixed conifer forest were obtained with an increment borer and a chain-saw. Standard dendrochronological techniques were used to process and date each one of the rings to their exact year of formation. The quality of dating of the measured series was analyzed with the COFECHA program, while biological trends not related to climate (age differences, stem-size increases, and disturbances were removed by standardization procedures in the ARSTAN program. Tree ring series of earlywood, latewood and total ring width were developed for the last four centuries. The total ring-width chronology was significantly associated (r>0.40, p=0.000 with nearby chronologies, particularly those located <200 km apart along the western slopes of the Sierra Madre Occidental (SMO observing correlations as high as 0.69 (p<0.001. Association between chronologies decreased for those sites in the state of Durango along the SMO but separated more than 200 km in straight line and also for sites in nearby borderline in the USA side. The similar climatic response among distant chronologies implies the influence of common atmospheric circulatory patterns affecting a large portion of land simultaneously. ENSO is one of the most important factors in determining inter-annual and multiannual hydroclimatic variability in northern Mexico, increasing winter-spring precipitation in its warm phase and causing extreme droughts in its cold phase.

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.

TRPM8 mediates cold and menthol allergies associated with mast cell activation.

Science.gov (United States)

Cho, Yeongyo; Jang, Yongwoo; Yang, Young Duk; Lee, Chang-Hun; Lee, Yunjong; Oh, Uhtaek

2010-10-01

Exposure to low temperatures often causes allergic responses or urticaria. Similarly, menthol, a common food additive is also known to cause urticaria, asthma, and rhinitis. However, despite the obvious clinical implications, the molecular mechanisms responsible for inducing allergic responses to low temperatures and menthol have not been determined. Because a non-selective cation channel, transient receptor potential subtype M8 (TRPM8) is activated by cold and menthol, we hypothesized that this channel mediates cold- and menthol-induced histamine release in mast cells. Here, we report that TRPM8 is expressed in the basophilic leukemia mast cell line, RBL-2H3, and that exposure to menthol or low temperatures induced Ca(2+) influx in RBL-2H3 cells, which was reversed by a TRPM8 blocker. Furthermore, menthol, a TRPM8 agonist, induced the dose-dependent release of histamine from RBL-2H3 cells. When TRPM8 transcripts were reduced by siRNA (small interfering RNA), menthol- and cold-induced Ca(2+) influx and histamine release were significantly reduced. In addition, subcutaneous injection of menthol evoked scratching, a typical histamine-induced response which was reversed by a TRPM8 blocker. Thus, our findings indicate that TRPM8 mediates the menthol- and cold-induced allergic responses of mast cells, and suggest that TRPM8 antagonists be viewed as potential treatments for cold- and menthol-induced allergies. Copyright © 2010 Elsevier Ltd. All rights reserved.

Condensation reactions of glucose and aromatic ring; Glucose to hokokan tono shukugo hanno

Energy Technology Data Exchange (ETDEWEB)

Komano, T.; Mashimo, K.; Wainai, T.; Tanaka, C.; Yoshioka, T. [Nihon University, Tokyo (Japan). College of Science and Technology; Sugimoto, Y.; Miki, Y. [National Institute of Materials and Chemical Research, Tsukuba (Japan)

1996-10-28

For artificial coalification, condensation reactions of aromatic ring and activated compounds produced by dehydrating reaction of glucose were studied experimentally. In heat treatment experiment in water, three reaction specimens such as glucose, glucose and phenol, and glucose and benzaldehyde were fed into an autoclave together with distilled water, and subjected to reaction at 180{degree}C under spontaneous pressure for 50 hours. In hydrogenation experiment, the specimens were fed into an autoclave together with tetradecane and sulfurization catalyst, and subjected to reaction at 350{degree}C under initial pressure of 9.8MPa for 2 hours for gas chromatography (GC) analysis of products. As the experimental result, the reaction between glucose and aromatic ring in heat treatment in water occurred between aromatic ring and active fragment with a mean carbon number of 4-5 produced by decomposition of glucose. The reactivity was higher in benzaldehyde addition than phenol addition. 3 refs., 4 figs., 1 tab.

Cold neutron production and application

International Nuclear Information System (INIS)

Inoue, Kazuhiko; Watanabe, Noboru.

1976-01-01

The first part gives general introduction to cold neutrons, namely the definition and the role as a probe in basic science and technology. The second part reviews various methods of cold neutron production. Some physical characteristics required for cold moderators are presented, and a list summarizes a number of cold moderators and their reactor physics constants. The definition of flux gain factor and the measured values for liquid light- and heavy-hydrogen are also given. The cold neutron spectra in methane and liquid hydrogen measured by LINAC time-of-flight method are presented to show the advantage of solid methane. The cold neutron sources using experimental reactors or linear accelerators are explained along with the examples of existing facilities. Two Japanese programs, the one is the use of a high flux reactor and the other is the use of a LINAC, are also presented. The third part of this report reviews the application areas of cold neutrons. (Aoki, K.)

Effects of cold temperatures on the excitability of rat trigeminal ganglion neurons that are not for cold-sensing

Science.gov (United States)

Kanda, Hirosato; Gu, Jianguo G.

2016-01-01

Except a small population of primary afferent neurons for sensing cold to generate the sensations of innocuous and noxious cold, it is generally believed that cold temperatures suppress the excitability of other primary afferent neurons that are not for cold-sensing. These not-for-cold-sensing neurons include the majority of non-nociceptive and nociceptive afferent neurons. In the present study we have found that not-for-cold-sensing neurons of rat trigeminal ganglia (TG) change their excitability in several ways at cooling temperatures. In nearly 70% of not-for-cold-sensing TG neurons, the cooling temperature of 15°C increases their membrane excitability. We regard these neurons as cold-active neurons. For the remaining 30% of not-for-cold-sensing TG neurons, the cooling temperature of 15°C either has no effect (regarded as cold-ineffective neurons) or suppress (regarded as cold-suppressive neurons) their membrane excitability. For cold-active neurons, the cold temperature of 15°C increases their excitability as is evidenced by the increases in action potential (AP) firing numbers and/or reduction of AP rheobase when these neurons are depolarized electrically. The cold temperature of 15°C significantly inhibits M-currents and increases membrane input resistance of cold-active neurons. Retigabine, an M-current activator, abolishes the effect of cold temperatures on AP firing but not the effect of cold temperature on AP rheobase levels. The inhibition of M-currents and the increases of membrane input resistance are likely two mechanisms by which cooling temperatures increase the excitability of not-for-cold-sensing TG neurons. PMID:26709732

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.)

The Nav1.9 channel is a key determinant of cold pain sensation and cold allodynia.

Science.gov (United States)

Lolignier, Stéphane; Bonnet, Caroline; Gaudioso, Christelle; Noël, Jacques; Ruel, Jérôme; Amsalem, Muriel; Ferrier, Jérémy; Rodat-Despoix, Lise; Bouvier, Valentine; Aissouni, Youssef; Prival, Laetitia; Chapuy, Eric; Padilla, Françoise; Eschalier, Alain; Delmas, Patrick; Busserolles, Jérôme

2015-05-19

Cold-triggered pain is essential to avoid prolonged exposure to harmfully low temperatures. However, the molecular basis of noxious cold sensing in mammals is still not completely understood. Here, we show that the voltage-gated Nav1.9 sodium channel is important for the perception of pain in response to noxious cold. Nav1.9 activity is upregulated in a subpopulation of damage-sensing sensory neurons responding to cooling, which allows the channel to amplify subthreshold depolarizations generated by the activation of cold transducers. Consequently, cold-triggered firing is impaired in Nav1.9(-/-) neurons, and Nav1.9 null mice and knockdown rats show increased cold pain thresholds. Disrupting Nav1.9 expression in rodents also alleviates cold pain hypersensitivity induced by the antineoplastic agent oxaliplatin. We conclude that Nav1.9 acts as a subthreshold amplifier in cold-sensitive nociceptive neurons and is required for the perception of cold pain under normal and pathological conditions. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Cold-Weather Sports

Science.gov (United States)

... Videos for Educators Search English Español Cold-Weather Sports KidsHealth / For Teens / Cold-Weather Sports What's in this article? What to Do? Classes ... weather. What better time to be outdoors? Winter sports can help you burn calories, increase your cardiovascular ...

Molecular spectrum of laterally coupled quantum rings under intense terahertz radiation.

Science.gov (United States)

Baghramyan, Henrikh M; Barseghyan, Manuk G; Laroze, David

2017-09-05

We study the influence of intense THz laser radiation and electric field on molecular states of laterally coupled quantum rings. Laser radiation shows the capability to dissociate quantum ring molecule and add 2-fold degeneracy to the molecular states at the fixed value of the overlapping size between rings. It is shown that coupled to decoupled molecular states phase transition points form almost a straight line with a slope equal to two. In addition, the electric field direction dependent energy spectrum shows unexpected oscillations, demonstrating strong coupling between molecular states. Besides, intraband absorption is considered, showing both blue and redshifts in its spectrum. The obtained results can be useful for the controlling of degeneracy of the discrete energy spectrum of nanoscale structures and in the tunneling effects therein.

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

Carbon-14 in tree rings

International Nuclear Information System (INIS)

Cain, W.F.; Suess, H.E.

1976-01-01

In order to investigate how reliably the carbon 14 content of tree rings reflects that of atmospheric carbon dioxide, two types of determinations were carried out: (1) carbon 14 determinations in annual rings from the beginning of this century until 1974 and (2) carbon 14 determinations in synchronous wood from the North American bristlecone pine and from European oak trees, dendrochronologically dated to have grown in the third and fourth century B.C. The first series of measurements showed that bomb-produced radiocarbon was incorporated in wood at a time when it was converted from sapwood to heartwood, whenever radiocarbon from bomb testing was present in the atmosphere. The second series showed that wood more than 2000 years old and grown on two different continents at different altitudes had, within the limits of experimental error, the same radiocarbon content. This work and other experimental evidence, obtained in part by other laboratories, show that tree rings reflect the average radiocarbon content of global atmospheric carbon dioxide accurately within several parts per mil. In rare cases, deviations of up to 10 parts per thousand may be possible. This means that a typical single radiocarbon date for wood or charcoal possesses an intrinsic uncertainty (viz., an estimated ''one-sigma error'' in addition to all the other errors) of the order of +-50 years. This intrinsic uncertainty is independent of the absolute age of the sample. More accurate dates can, in principle, be obtained by the so-called method of ''wiggle matching.''

An N-body Integrator for Planetary Rings

Science.gov (United States)

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.

Minimal Gromov-Witten rings

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

Context-dependent effects of cold stress on behavioral, physiological, and life-history traits of the red flour beetle.

Science.gov (United States)

Scharf, Inon; Wertheimer, Keren-Or; Xin, Joy Lim; Gilad, Tomer; Goldenberg, Inna; Subach, Aziz

2017-06-20

Animals are exposed in nature to a variety of stressors. While stress is generally harmful, mild stress can also be beneficial and contribute to reproduction and survival. We studied the effect of five cold shock events versus a single cold shock and a control group, representing three levels of stress (harsh, mild, and no stress), on behavioral, physiological, and life-history traits of the red flour beetle (Tribolium castaneum, Herbst 1797). Beetles exposed to harsh cold stress were less active than a control group: they moved less and failed more frequently to detect a food patch. Their probability to mate was also lower. Beetle pairs exposed to harsh cold stress frequently failed to reproduce at all, and if reproducing, females laid fewer eggs, which were, as larvae in mid-development, smaller than those in the control group. However, harsh cold stress led to improved female starvation tolerance, probably due to enhanced lipid accumulation. Harsh cold shock also improved tolerance to an additional cold shock compared to the control. Finally, a single cold shock event negatively affected fewer measured response variables than the harsh cold stress, but also enhanced neither starvation tolerance nor tolerance to an additional cold shock. The consequences of a harsher cold stress are thus not solely detrimental but might even enhance survival under stressful conditions. Under benign conditions, nevertheless, harsh stress impedes beetle performance. The harsh stress probably shifted the balance point of the survival-reproduction trade-off, a shift that did not take place following exposure to mild stress. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Electro-optical hybrid slip ring

Science.gov (United States)

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

Carotenoid β-Ring Hydroxylase and Ketolase from Marine Bacteria—Promiscuous Enzymes for Synthesizing Functional Xanthophylls

Science.gov (United States)

Misawa, Norihiko

2011-01-01

Marine bacteria belonging to genera Paracoccus and Brevundimonas of the α-Proteobacteria class can produce C40-type dicyclic carotenoids containing two β-end groups (β rings) that are modified with keto and hydroxyl groups. These bacteria produce astaxanthin, adonixanthin, and their derivatives, which are ketolated by carotenoid β-ring 4(4′)-ketolase (4(4′)-oxygenase; CrtW) and hydroxylated by carotenoid β-ring 3(3′)-hydroxylase (CrtZ). In addition, the genus Brevundimonas possesses a gene for carotenoid β-ring 2(2′)-hydroxylase (CrtG). This review focuses on these carotenoid β-ring-modifying enzymes that are promiscuous for carotenoid substrates, and pathway engineering for the production of xanthophylls (oxygen-containing carotenoids) in Escherichia coli, using these enzyme genes. Such pathway engineering researches are performed towards efficient production not only of commercially important xanthophylls such as astaxanthin, but also of xanthophylls minor in nature (e.g., β-ring(s)-2(2′)-hydroxylated carotenoids). PMID:21673887

Carotenoid β-Ring Hydroxylase and Ketolase from Marine Bacteria—Promiscuous Enzymes for Synthesizing Functional Xanthophylls

Directory of Open Access Journals (Sweden)

Norihiko Misawa

2011-05-01

Full Text Available Marine bacteria belonging to genera Paracoccus and Brevundimonas of the α-Proteobacteria class can produce C40-type dicyclic carotenoids containing two β-end groups (β rings that are modified with keto and hydroxyl groups. These bacteria produce astaxanthin, adonixanthin, and their derivatives, which are ketolated by carotenoid β-ring 4(4′-ketolase (4(4′-oxygenase; CrtW and hydroxylated by carotenoid β-ring 3(3′-hydroxylase (CrtZ. In addition, the genus Brevundimonas possesses a gene for carotenoid β-ring 2(2′-hydroxylase (CrtG. This review focuses on these carotenoid β-ring-modifying enzymes that are promiscuous for carotenoid substrates, and pathway engineering for the production of xanthophylls (oxygen-containing carotenoids in Escherichia coli, using these enzyme genes. Such pathway engineering researches are performed towards efficient production not only of commercially important xanthophylls such as astaxanthin, but also of xanthophylls minor in nature (e.g., β-ring(s-2(2′-hydroxylated carotenoids.

Carotenoid β-ring hydroxylase and ketolase from marine bacteria-promiscuous enzymes for synthesizing functional xanthophylls.

Science.gov (United States)

Misawa, Norihiko

2011-01-01

Marine bacteria belonging to genera Paracoccus and Brevundimonas of the α-Proteobacteria class can produce C₄₀-type dicyclic carotenoids containing two β-end groups (β rings) that are modified with keto and hydroxyl groups. These bacteria produce astaxanthin, adonixanthin, and their derivatives, which are ketolated by carotenoid β-ring 4(4')-ketolase (4(4')-oxygenase; CrtW) and hydroxylated by carotenoid β-ring 3(3')-hydroxylase (CrtZ). In addition, the genus Brevundimonas possesses a gene for carotenoid β-ring 2(2')-hydroxylase (CrtG). This review focuses on these carotenoid β-ring-modifying enzymes that are promiscuous for carotenoid substrates, and pathway engineering for the production of xanthophylls (oxygen-containing carotenoids) in Escherichia coli, using these enzyme genes. Such pathway engineering researches are performed towards efficient production not only of commercially important xanthophylls such as astaxanthin, but also of xanthophylls minor in nature (e.g., β-ring(s)-2(2')-hydroxylated carotenoids).

Double acting stirling engine piston ring

Science.gov (United States)

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.

Effects of heat and cold on health, with special reference to Finnish sauna bathing.

Science.gov (United States)

Heinonen, Ilkka; Laukkanen, Jari A

2018-05-01

Environmental stress such as extremely warm or cold temperature is often considered a challenge to human health and body homeostasis. However, the human body can adapt relatively well to heat and cold environments, and recent studies have also elucidated that particularly heat stress might be even highly beneficial for human health. Consequently, the aim of the present brief review is first to discuss general cardiovascular and other responses to acute heat stress, followed by a review of beneficial effects of Finnish sauna bathing on general and cardiovascular health and mortality as well as dementia and Alzheimer's disease risk. Plausible mechanisms included are improved endothelial and microvascular function, reduced blood pressure and arterial stiffness, and possibly increased angiogenesis in humans, which are likely to mediate the health benefits of sauna bathing. In addition to heat exposure with physiological adaptations, cold stress-induced physiological responses and brown fat activation on health are also discussed. This is important to take into consideration, as sauna bathing is frequently associated with cooling periods in cold(er) environments, but their combination remains poorly investigated. We finally propose, therefore, that possible additive effects of heat- and cold-stress-induced adaptations and effects on health would be worthy of further investigation.

Cold fusion

International Nuclear Information System (INIS)

Koster, J.

1989-01-01

In this contribution the author the phenomenom of so-called cold fusion, inspired by the memorable lecture of Moshe Gai on his own search for this effect. Thus much of what follows was presented by Dr. Gai; the rest is from independent reading. What is referred to as cold fusion is of course the observation of possible products of deuteron-deuteron (d-d) fusion within deuterium-loaded (dentended) electrodes. The debate over the two vanguard cold fusion experiments has raged under far more public attention than usually accorded new scientific phenomena. The clamor commenced with the press conference of M. Fleishmann and S. Pons on March 23, 1989 and the nearly simultaneous wide circulation of a preprint of S. Jones and collaborators. The majority of work attempting to confirm these observations has at the time of this writing yet to appear in published form, but contributions to conferences and electronic mail over computer networks were certainly filled with preliminary results. To keep what follows to a reasonable length the author limit this discussion to the searches for neutron (suggested by ref. 2) or for excessive heat production (suggested by ref. 1), following a synopsis of the hypotheses of cold fusion

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.

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...

Topological rings

CERN Document Server

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.

Energy spectra of quantum rings.

Science.gov (United States)

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.

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...

Ultra-low energy storage ring at FLAIR

International Nuclear Information System (INIS)

Welsch, Carsten P.; Papash, A. I.; Gorda, O.; Harasimowicz, J.; Karamyshev, O.; Karamysheva, G.; Newton, D.; Panniello, M.; Putignano, M.; Siggel-King, M. R. F.; Smirnov, A.

2012-01-01

The Ultra-low energy electrostatic Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will provide cooled beams of antiprotons in the energy range between 300 keV down to 20 keV and possibly less. The USR has been completely redesigned over the past three years. The ring structure is based on a “split achromat” lattice that allows in-ring experiments with internal gas jet target. Beam parameters might be adjusted in a wide range: from very short pulses in the nanosecond regime to a Coasting beam. In addition, a combined fast and slow extraction scheme was developed that allows for providing external experiments with cooled beams of different time structure. Detailed investigations of the USR, including studies into the ring’s long term beam dynamics, life time, equilibrium momentum spread and equilibrium lateral spread during collisions with an internal target were carried out. New tools and beam handling techniques for diagnostics of ultra-low energy ions at beam intensities less than 10 6 were developed by the QUASAR Group. In this paper, progress on the USR project will be presented with an emphasis on the expected beam parameters available to the experiments at FLAIR.

The Lord of Rings - the mysterious case of the stolen rings: a critical analysis

Science.gov (United States)

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

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)

The ITER pre-compression rings – A first in cryogenic composite technology

International Nuclear Information System (INIS)

Rajainmaki, Hannu; Fanthome, John; Losasso, Marcello; Foussat, Arnaud; Rodriguez, Jesus; Evans, David; Diaz, Victor

2014-01-01

The ITER Pre-Compression Rings represent one of the heaviest composite structures ever manufactured as a single piece and the largest - the outer diameter will be above 5.5 meters - intended for use in a cryogenic environment. With a cross section of 337 mm × 288 mm, each item will weigh more than 3,000 kg. A development program, based on filament wound and dry wound S2 glass unidirectional fibers, the latter processed by VARTM, was completed on one fifth scale rings, and these materials and techniques were shown to be satisfactory. The paper describes how a technology applied to build up primary structures of European launchers is being accommodated to produce the ITER Pre-Compression Rings, fulfilling its extremely challenging requirements. In addition, we will describe how the structural analysis is correlated with the test results of scaled down rings, as well as how the pre-compression rings’ manufacturing process will be qualified

Cold acclimation and cognitive performance: A review.

Science.gov (United States)

Jones, Douglas M; Bailey, Stephen P; Roelands, Bart; Buono, Michael J; Meeusen, Romain

2017-12-01

Athletes, occupational workers, and military personnel experience cold temperatures through cold air exposure or cold water immersion, both of which impair cognitive performance. Prior work has shown that neurophysiological pathways may be sensitive to the effects of temperature acclimation and, therefore, cold acclimation may be a potential strategy to attenuate cold-induced cognitive impairments for populations that are frequently exposed to cold environments. This review provides an overview of studies that examine repeated cold stress, cold acclimation, and measurements of cognitive performance to determine whether or not cold acclimation provides beneficial protection against cold-induced cognitive performance decrements. Studies included in this review assessed cognitive measures of reaction time, attention, logical reasoning, information processing, and memory. Repeated cold stress, with or without evidence of cold acclimation, appears to offer no added benefit of improving cognitive performance. However, research in this area is greatly lacking and, therefore, it is difficult to draw any definitive conclusions regarding the use of cold acclimation to improve cognitive performance during subsequent cold exposures. Given the current state of minimal knowledge on this topic, athletes, occupational workers, and military commands looking to specifically enhance cognitive performance in cold environments would likely not be advised to spend the time and effort required to become acclimated to cold. However, as more knowledge becomes available in this area, recommendations may change. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of the Ring Current on ULF Waves in the Magnetosphere

Directory of Open Access Journals (Sweden)

Khan-Hyuk Kim

1994-06-01

Full Text Available A three-dimensional box model has been developed to study the MHD wave coupling in the magnetosphere. In this model, the effects of the ring current are included by assuming the pressure gradients in the MHD equations. It is found that the axisymmetric ring current may play an important role in producing spectral noises in compressional waves, while field line resonances have no such disturbances. These results may explain the current observational characteristics that compressional cavity modes hardly appear in the satellite experiment, while field line resonances often occur. Our numerical results also suggest that any discrete spectral peaks such as the global cavity modes can hardly occur where the pressure distribution of the ring current becomes important. The continuous band of transverse waves is found to be unperturbed until the ring current becomes significantly asymmetric with respect to the dipole axis. In addition, our results in the absence of the pressure gradient are found to be consistent with the previous results from the box-like and dipole models.

A Survey of Precipitation-Induced Atmospheric Cold Pools over Oceans and Their Interactions with the Larger-Scale Environment

Science.gov (United States)

Zuidema, Paquita; Torri, Giuseppe; Muller, Caroline; Chandra, Arunchandra

2017-11-01

Pools of air cooled by partial rain evaporation span up to several hundreds of kilometers in nature and typically last less than 1 day, ultimately losing their identity to the large-scale flow. These fundamentally differ in character from the radiatively-driven dry pools defining convective aggregation. Advancement in remote sensing and in computer capabilities has promoted exploration of how precipitation-induced cold pool processes modify the convective spectrum and life cycle. This contribution surveys current understanding of such cold pools over the tropical and subtropical oceans. In shallow convection with low rain rates, the cold pools moisten, preserving the near-surface equivalent potential temperature or increasing it if the surface moisture fluxes cannot ventilate beyond the new surface layer; both conditions indicate downdraft origin air from within the boundary layer. When rain rates exceed ˜ 2 mm h^{-1}, convective-scale downdrafts can bring down drier air of lower equivalent potential temperature from above the boundary layer. The resulting density currents facilitate the lifting of locally thermodynamically favorable air and can impose an arc-shaped mesoscale cloud organization. This organization allows clouds capable of reaching 4-5 km within otherwise dry environments. These are more commonly observed in the northern hemisphere trade wind regime, where the flow to the intertropical convergence zone is unimpeded by the equator. Their near-surface air properties share much with those shown from cold pools sampled in the equatorial Indian Ocean. Cold pools are most effective at influencing the mesoscale organization when the atmosphere is moist in the lower free troposphere and dry above, suggesting an optimal range of water vapor paths. Outstanding questions on the relationship between cold pools, their accompanying moisture distribution and cloud cover are detailed further. Near-surface water vapor rings are documented in one model inside but

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)

Transcriptomic analysis of (group I Clostridium botulinum ATCC 3502 cold shock response.

Directory of Open Access Journals (Sweden)

Elias Dahlsten

Full Text Available Profound understanding of the mechanisms foodborne pathogenic bacteria utilize in adaptation to the environmental stress they encounter during food processing and storage is of paramount importance in design of control measures. Chill temperature is a central control measure applied in minimally processed foods; however, data on the mechanisms the foodborne pathogen Clostridium botulinum activates upon cold stress are scarce. Transcriptomic analysis on the C. botulinum ATCC 3502 strain upon temperature downshift from 37°C to 15°C was performed to identify the cold-responsive gene set of this organism. Significant up- or down-regulation of 16 and 11 genes, respectively, was observed 1 h after the cold shock. At 5 h after the temperature downshift, 199 and 210 genes were up- or down-regulated, respectively. Thus, the relatively small gene set affected initially indicated a targeted acute response to cold shock, whereas extensive metabolic remodeling appeared to take place after prolonged exposure to cold. Genes related to fatty acid biosynthesis, oxidative stress response, and iron uptake and storage were induced, in addition to mechanisms previously characterized as cold-tolerance related in bacteria. Furthermore, several uncharacterized DNA-binding transcriptional regulator-encoding genes were induced, suggesting involvement of novel regulatory mechanisms in the cold shock response of C. botulinum. The role of such regulators, CBO0477 and CBO0558A, in cold tolerance of C. botulinum ATCC 3502 was demonstrated by deteriorated growth of related mutants at 17°C.

Human whole body cold adaptation.

OpenAIRE

Daanen, Hein A.M.; Van Marken Lichtenbelt, Wouter D.

2016-01-01

ABSTRACT Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000?y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations...

SMARANDACHE NON-ASSOCIATIVE RINGS

OpenAIRE

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...

Coulomb collisions of ring current particles: Indirect source of heat for the ionosphere

Science.gov (United States)

Cole, K. D.

1975-01-01

The additional energy requirements of the topside ionosphere during a magnetic storm are less than one quarter of the ring current energy. This energy is supplied largely by Coulomb collisions of ring current protons of energy less than about 20 keV with background thermal electrons which conduct the heat to the ionosphere. Past criticisms are discussed of this mechanism for the supply of energy to the SAR-arc and neighboring regions of the ionosphere.

Human whole body cold adaptation.

NARCIS (Netherlands)

Daanen, Hein A.M.; Van Marken Lichtenbelt, Wouter D.

2016-01-01

Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced

Moving ring reactor 'Karin-1'

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.)

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.

The ring plus project: safety and acceptability of vaginal rings that protect women from unintended pregnancy

OpenAIRE

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...

Cold spray NDE for porosity and other process anomalies

Science.gov (United States)

Glass, S. W.; Larche, M. R.; Prowant, M. S.; Suter, J. D.; Lareau, J. P.; Jiang, X.; Ross, K. A.

2018-04-01

This paper describes a technology review of nondestructive evaluation (NDE) methods that can be applied to cold spray coatings. Cold spray is a process for depositing metal powder at high velocity so that it bonds to the substrate metal without significant heating that would be likely to cause additional residual tensile stresses. Coatings in the range from millimeters to centimeters are possible at relatively high deposition rates. Cold spray coatings that may be used for hydroelectric components that are subject to erosion, corrosion, wear, and cavitation damage are of interest. The topic of cold spray NDE is treated generally, however, but may be considered applicable to virtually any cold spray application except where there are constraints of the hydroelectric component application that bear special consideration. Optical profilometry, eddy current, ultrasound, and hardness tests are shown for one set of good, fair, and poor nickel-chrome (NiCr) on 304 stainless steel (304SS) cold spray samples to demonstrate inspection possibilities. The primary indicator of cold spray quality is the cold spray porosity that is most directly measured with witness-sample destructive examinations (DE)—mostly photo-micrographs. These DE-generated porosity values are correlated with optical profilometry, eddy current, ultrasound, and hardness test NDE methods to infer the porosity and other information of interest. These parameters of interest primarily include: • Porosity primarily caused by improper process conditions (temperature, gas velocity, spray standoff, spray angle, powder size, condition, surface cleanliness, surface oxide, etc.) • Presence/absence of the cold spray coating including possible over-sprayed voids • Coating thicknessOptical profilometry measurements of surface roughness trended with porosity plus, if compared with a reference measurement or reference drawing, would provide information on the coating thickness. Ultrasound could provide similar

Pyrimidine-pyridine ring interconversion

NARCIS (Netherlands)

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

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)

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

Investigating temperature breaks in the summer fruit export cold chain: A case study

Directory of Open Access Journals (Sweden)

Heinri W. Freiboth

2013-11-01

Full Text Available There is concern in the South African fruit industry that a large amount of fruit and money is lost every season due to breaks in the fruit export cold chain. The possibility of a large percentage of losses in a significant sector of the economy warranted further investigation. This article attempted to highlight some of the possible problem areas in the cold chain, from the cold store to the port, by analysing historic temperature data from different fruit export supply chains of apples, pears and grapes. In addition, a trial shipment of apples was used to investigate temperature variation between different pallets in the same container. This research has added value to the South African fruit industry by identifying the need to improve operational procedures in the cold chain.

Spectroscopy with cold and ultra-cold neutrons

Directory of Open Access Journals (Sweden)

Abele Hartmut

2015-01-01

Full Text Available We present two new types of spectroscopy methods for cold and ultra-cold neutrons. The first method, which uses the R×B drift effect to disperse charged particles in a uniformly curved magnetic field, allows to study neutron β-decay. We aim for a precision on the 10−4 level. The second method that we refer to as gravity resonance spectroscopy (GRS allows to test Newton’s gravity law at short distances. At the level of precision we are able to provide constraints on any possible gravity-like interaction. In particular, limits on dark energy chameleon fields are improved by several orders of magnitude.

FEL radiation power available in electron storage rings

International Nuclear Information System (INIS)

Miyahara, Yoshikazu

1994-01-01

FEL radiation power available in electron storage rings was studied in the small signal regime in considering the increase of the energy spread of the electron beam caused by the FEL interaction and the decrease of the FEL gain with the increase of the energy spread in addition to the radiation damping and the quantum excitation. All these effects were considered separately, and combined with FEL power equations. The radiation power available was expressed explicitly with the parameters of the storage ring, the wiggler and the mirrors. The transient process of FEL lasing is simulated with the power equations. A rough estimation is made of the radiation power available by the FEL at different beam energies, and optimization of FEL parameters for a higher radiation power is discussed. ((orig.))

Cold recovery during regasification of LNG part one: Cold utilization far from the regasification facility

International Nuclear Information System (INIS)

La Rocca, Vincenzo

2010-01-01

The paper deals with cold recovery during LNG regasification. The applications analyzed pertain to the use in deep freezing agro food industry and in space air conditioning facilities in commercial sector (Supermarkets and Hypermarkets) of cold recovered from the regasification process. A modular LNG regasification unit is proposed having the regasification capacity of 2 BCM/year of gas and it is based on use of a Power Cycle working with Ethane, this unit allows operation of cold energy transfer, contained in LNG to be regasified, in a range of temperatures suitable for multipurpose use of cold, reducing regasification process irreversibility. Some electric energy is produced by the Power Cycle, but the purpose of the modular unit is to deliver cold suitable for industrial and commercial use in the proper temperature range utilizing Carbon dioxide as secondary fluid to transfer cold from regasification site to far end users. The subject is divided in two papers: this paper deals with facilities delivering cold released during LNG regasification and related pipeline facilities to transfer cold at far end users while the other paper pertains to analysis of end users applications. Results of a detailed thermodynamic and economic analysis demonstrate the suitability of the proposal.

Charge breeding investigation in EBIS/T and collision study of ions with cold atoms for HITRAP

Energy Technology Data Exchange (ETDEWEB)

Sokolov, Alexey

2010-01-29

Highly charged ions (HCI) at low velocities or at rest are interesting systems for various atomic physics experiments. For investigations on HCI of heavy stable or radioactive nuclides the HITRAP (Highly charged Ion TRAP) decelerator facility has been set up at GSI to deliver cooled beams of HCI at an energy of 5 keV/q. The HCI are produced in a stripper foil at relativistic energies and are decelerated in several steps at ESR storage ring and HITRAP before they are delivered to experimental setups. One of the experiments is the investigation of multi-electron charge exchange in collisions of heavy HCI with cold atoms using novel MOTRIMS technique. Collision experiments on light ions from an ECR ion source colliding with cold atoms in a MOT have been performed and the results are described. An electron beam ion trap (EBIT) has been tested and optimized for commissioning of the HITRAP physics experiments. The process of charge breeding in the EBIT has been successfully studied with gaseous elements and with an alkaline element injected from an external ion source. (orig.)

Charge breeding investigation in EBIS/T and collision study of ions with cold atoms for HITRAP

International Nuclear Information System (INIS)

Sokolov, Alexey

2010-01-01

Highly charged ions (HCI) at low velocities or at rest are interesting systems for various atomic physics experiments. For investigations on HCI of heavy stable or radioactive nuclides the HITRAP (Highly charged Ion TRAP) decelerator facility has been set up at GSI to deliver cooled beams of HCI at an energy of 5 keV/q. The HCI are produced in a stripper foil at relativistic energies and are decelerated in several steps at ESR storage ring and HITRAP before they are delivered to experimental setups. One of the experiments is the investigation of multi-electron charge exchange in collisions of heavy HCI with cold atoms using novel MOTRIMS technique. Collision experiments on light ions from an ECR ion source colliding with cold atoms in a MOT have been performed and the results are described. An electron beam ion trap (EBIT) has been tested and optimized for commissioning of the HITRAP physics experiments. The process of charge breeding in the EBIT has been successfully studied with gaseous elements and with an alkaline element injected from an external ion source. (orig.)

Detection and direction discrimination of single vortex rings by harbour seals (Phoca vitulina).

Science.gov (United States)

Krüger, Yvonne; Hanke, Wolf; Miersch, Lars; Dehnhardt, Guido

2018-04-25

Harbour seals possess highly sensitive vibrissae that enable them to track hydrodynamic trails left behind by a swimming fish. Most of these trails contain vortex rings as a main hydrodynamic component. They may reveal information about their generator as the trails differ depending on the fish species, the fish's body shape, size and swimming style. In addition, fish generate single vortex rings in diverse natural situations. In this study, the ability of blindfolded stationary harbour seals to detect and analyse single vortex rings regarding directional information has been investigated. In three different behavioural experiments, the animals were trained to respond to single artificially generated vortex rings. The results show that harbour seals are able to respond to a variety of different vortex rings upon vibrissal stimulation. The investigation of the minimum hydrodynamically perceivable angle revealed that it is at least as small as 5.7 deg, which was the smallest adjustable angle. Moreover, harbour seals are capable of analysing the travel direction of a vortex ring perceived by the mystacial vibrissae irrespective of whether the vibrissae were stimulated ipsilaterally or contralaterally. In situations in which no complex hydrodynamic trail is available, it is advantageous for a hunting seal to be able to extract information from a single vortex ring. © 2018. Published by The Company of Biologists Ltd.

An advanced hadron facility: A combined kaon factory and cold-neutron source

International Nuclear Information System (INIS)

Thiessen, H.A.

1987-01-01

A design concept is presented for an advanced hadron facility consisting of a combined kaon factory and second generation spallation source. Our proposed facility consists of a 1.2 GeV superconducting H - linac to bring the LAMPF energy up to 2 GeV, a multi-ring 2 GeV compressor, a shared cold-neutron and stopped-pion neutrino source, a 60 GeV 25 μAmp 6 Hz proton synchrotron, and kaon and proton experimental areas. We discuss the considerations which led to this design concept. We summarize recent results of r and d work on components for rapid-cycling synchrotrons. Finally, we mention briefly a pion linac, which may be a good way to gain experience with superconducting cavities if advanced hadron facility funding is delayed

Present status of beam position stabilization at photon factory storage ring

International Nuclear Information System (INIS)

Nakamura, Norio

1990-01-01

Stabilization of photon beam position became a major issue in the operation of the storage rings dedicated as synchrotron radiation source. At the Photon Factory storage ring (PF ring), the orbit movement appeared remarkably when the low-emittance operation started. This orbit movement became a serious problem to synchrotron radiation users because the photon beam to drift with a large amplitude. The horizontal and vertical orbit feedback systems were constructed and developed in order to suppress the orbit movement globally. As a result, the horizontal and vertical orbit movements were reduced by a factor of five and ten, respectively. In addition, another type of feedback system using a local bump was constructed. In the test operation, this system could remove the fast photon beam motion as well as the slow photon beam drift for a beamline. (author)

Interaction of Vortex Ring with Cutting Plate

Science.gov (United States)

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.

Synchronization in a Random Length Ring Network for SDN-Controlled Optical TDM Switching

DEFF Research Database (Denmark)

Kamchevska, Valerija; Cristofori, Valentina; Da Ros, Francesco

2016-01-01

. In addition, we propose a novel synchronization algorithm that enables automatic synchronization of software defined networking controlled all-optical TDM switching nodes connected in a ring network. Besides providing synchronization, the algorithm also can facilitate dynamic slot size change and failure......In this paper we focus on optical time division multiplexed (TDM) switching and its main distinguishing characteristics compared with other optical subwavelength switching technologies. We review and discuss in detail the synchronization requirements that allow for proper switching operation...... detection. We experimentally validate the algorithm behavior and achieve correct operation for three different ring lengths. Moreover, we experimentally demonstrate data plane connectivity in a ring network composed of three nodes and show successful wavelength division multiplexing space division...

Highly Efficient Spin-Current Operation in a Cu Nano-Ring

Science.gov (United States)

Murphy, Benedict A.; Vick, Andrew J.; Samiepour, Marjan; Hirohata, Atsufumi

2016-11-01

An all-metal lateral spin-valve structure has been fabricated with a medial Copper nano-ring to split the diffusive spin-current path. We have demonstrated significant modulation of the non-local signal by the application of a magnetic field gradient across the nano-ring, which is up to 30% more efficient than the conventional Hanle configuration at room temperature. This was achieved by passing a dc current through a current-carrying bar to provide a locally induced Ampère field. We have shown that in this manner a lateral spin-valve gains an additional functionality in the form of three-terminal gate operation for future spintronic logic.

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

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

Persistent current in triangle silicene rings with spin–orbit interaction

Energy Technology Data Exchange (ETDEWEB)

Xu, Ning, E-mail: nxu@ycit.cn [Department of Physics, Yancheng Institute of Technology, Yancheng 224051 (China); Zhang, Haiyang; Wu, Xiuqiang; Bai, Yujie [Department of Physics, Yancheng Institute of Technology, Yancheng 224051 (China); Ding, Jianwen, E-mail: jwding@xtu.edu.cn [Department of Physics, Xiangtan University, Xiangtan 411105 (China)

2017-06-28

The energy spectrum and magnetic response of triangle silicene rings (TSRs) are investigated within the tight-binding model. It is shown that the flux-dependent energy spectrum is divided into bands, with three levels per band, owing to the three-fold rotational symmetry structure of TSRs. The zigzag TSRs are metallic, exhibiting either diamagnetic or paramagnetic response depending on the size of inner ring radius. Armchair TSRs are semiconducting, exhibiting diamagnetic response. Taking into account the intrinsic spin–orbit interaction, the magnetic-field-driven spin-up electrons flow anticlockwise around the TSRs and the spin-down electrons flow clockwise around the TSRs. Additionally, paramagnetism–diamagnetism or diamagnetism–paramagnetism transitions are observed with the increase of exchange field. The results may be very helpful for the design and application of TSR-based nanodevices. - Highlights: • The zigzag TSRs are metallic. • Armchair TSRs which exhibit diamagnetic response are semiconducting. • The spin-up electrons flow anticlockwise and spin-down electrons flow clockwise around the rings.

Cold dark matter plus not-so-clumpy dark relics

NARCIS (Netherlands)

Diamanti, R.; Ando, S.; Gariazzo, S.; Mena, O.; Weniger, C.

Various particle physics models suggest that, besides the (nearly) cold dark matter that accounts for current observations, additional but sub-dominant dark relics might exist. These could be warm, hot, or even contribute as dark radiation. We present here a comprehensive study of two-component dark

Green chemistry: Efficient epoxides ring-opening with 1-butanol under microwave irradiation

International Nuclear Information System (INIS)

Garcia-Vidal, Jesus A.; Duran-Valle, Carlos J.; Ferrera-Escudero, Santiago

2006-01-01

Two activated carbons treated with mineral acids (HNO 3 and sulfonitric mixture) have been tested as acid catalysts in the epoxides (1,2-epoxyhexane and styrene oxide) ring-opening reaction with 1-butanol under microwave (MW) irradiation. The mayor obtained product is that resulting of the alcohol addition to the most substituted carbon in the epoxide ring. The most active catalyst is that treated with sulfonitric mixture. The use of a MW oven allows achieving to the complete conversion of styrene oxide in only 2 min

Green chemistry: Efficient epoxides ring-opening with 1-butanol under microwave irradiation

Energy Technology Data Exchange (ETDEWEB)

Garcia-Vidal, Jesus A. [Departamento de Quimica Inorganica, Facultad de Ciencias, Universidad de Extremadura, Campus Universitario, Avda. de Elvas, s/n, E-06071-Badajoz (Spain); Duran-Valle, Carlos J. [Departamento de Quimica Inorganica, Facultad de Ciencias, Universidad de Extremadura, Campus Universitario, Avda. de Elvas, s/n, E-06071-Badajoz (Spain)]. E-mail: carlosdv@unex.es; Ferrera-Escudero, Santiago [Departamento de Quimica Inorganica y Quimica Tecnica, Universidad Nacional de Educacion a Distancia, C/Senda del Rey, 9, E-28040 Madrid (Spain)

2006-06-30

Two activated carbons treated with mineral acids (HNO{sub 3} and sulfonitric mixture) have been tested as acid catalysts in the epoxides (1,2-epoxyhexane and styrene oxide) ring-opening reaction with 1-butanol under microwave (MW) irradiation. The mayor obtained product is that resulting of the alcohol addition to the most substituted carbon in the epoxide ring. The most active catalyst is that treated with sulfonitric mixture. The use of a MW oven allows achieving to the complete conversion of styrene oxide in only 2 min.

A first course in noncommutative rings

CERN Document Server

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.

Age and Ethnic Differences in Cold Weather and Contagion Theories of Colds and Flu

Science.gov (United States)

Sigelman, Carol K.

2012-01-01

Age and ethnic group differences in cold weather and contagion or germ theories of infectious disease were explored in two studies. A cold weather theory was frequently invoked to explain colds and to a lesser extent flu but became less prominent with age as children gained command of a germ theory of disease. Explanations of how contact with…

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...

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.

Comparative transcriptomic analysis of the response to cold acclimation in Eucalyptus dunnii.

Directory of Open Access Journals (Sweden)

Yiqing Liu

Full Text Available Eucalyptus dunnii is an important macrophanerophyte with high economic value. However, low temperature stress limits its productivity and distribution. To study the cold response mechanisms of E. dunnii, 5 cDNA libraries were constructed from mRNA extracted from leaves exposed to cold stress for varying lengths of time and were evaluated by RNA-Seq analysis. The assembly of the Illumina datasets was optimized using various assembly programs and parameters. The final optimized assembly generated 205,325 transcripts with an average length of 1,701 bp and N50 of 2,627 bp, representing 349.38 Mb of the E. dunnii transcriptome. Among these transcripts, 134,358 transcripts (65.4% were annotated in the Nr database. According to the differential analysis results, most transcripts were up-regulated as the cold stress prolonging, suggesting that these transcripts may be involved in the response to cold stress. In addition, the cold-relevant GO categories, such as 'response to stress' and 'translational initiation', were the markedly enriched GO terms. The assembly of the E. dunnii gene index and the GO classification performed in this study will serve as useful genomic resources for the genetic improvement of E. dunnii and also provide insights into the molecular mechanisms of cold acclimation in E. dunnii.

Magnesium and diltiazem relaxes phenylephrine-precontracted rat aortic rings