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Sample records for compact sr ring

  1. Compact electron storage rings

    International Nuclear Information System (INIS)

    Williams, G.P.

    1987-01-01

    There have been many recent developments in the area of compact storage rings. Such rings would have critical wavelengths of typically 10 A, achieved with beam energies of several hundreds of MeV and superconducting dipole fields of around 5 Tesla. Although the primary motivation for progress in this area is that of commercial x-ray lithography, such sources might be an attractive source for college campuses to operate. They would be useful for many programs in materials science, solid state, x-ray microscopy and other biological areas. We discuss the properties of such sources and review developments around the world, primarily in the USA, japan and W. Germany

  2. A compact electron storage ring design

    International Nuclear Information System (INIS)

    Swenson, C.A.

    1992-01-01

    Electron storage rings are sources of synchrotron radiation in the soft and hard parts of the x-ray spectrum. X-ray lithography is an ideal candidate technology for the production of microelectronic devices with sizes between 0.3-0.5 microns. Industrial x-ray lithography requires the x-ray source, which is the electron storage ring, to be as compact and reliable as possible. In this thesis the author reviews and develops the basic physical principles governing the design of compact electron synchrotrons for x-ray lithography. He explores the various aspects of lattice design for this application. He argues that the optimal storage ring design consists of a four fold symmetric cell lattice with two quadrupole families and 90 degrees zero gradient dipole magnets. It is demonstrated that radiation requirements for lithography and the use of zero gradient magnetic dipole fields constrains the lattice to four or more dipole magnets. The author develops a lattice design for x-ray lithography following this logic. He then develops a dipole magnet design for a machine using this lattice. Particle tracking data is integrated into the magnet design and used to optimize the end coil configurations of the magnets. The author then reviews the magnet's physical construction and measurement. He develops a cryogenic Hall probe mapping apparatus for this magnet and measure its excitation curves

  3. 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)

  4. A compact SR light source for x-ray lithography 'AURORA'

    International Nuclear Information System (INIS)

    Toba, Y.

    1990-01-01

    A compact synchrotron radiation (SR) light source called AURORA has been developed for industrial use. It is specially designed for X-ray lithography. AURORA consists of a storage ring, injector microtron and SR light beam lines. The storage ring is a superconducting single magnet machine, designed to accelerate a 150 MeV electron beam to 650 MeV and to store as high as 300 mA current. The injector is a racetrack microtron (RTM) producing a pulsed 150 MeV beam. As many as 16 SR light beam channels are available for AURORA. Prototypes of the storage ring and RTM are constructed, and beam commissioning is performed. A hundred and fifty MeV electron beam of a pulsed current 10 μA from the RTM is successfully injected to the ring and accelerated to 600 MeV and 10 mA current stored with a lifetime of more than 20 hours. The half-integer method investigated is shown to work well with the injection efficiency being found to be very high. Improvement of the design is now under way. (N.K.)

  5. 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

  6. Project of the compact superconducting storage ring Siberia-SM

    Energy Technology Data Exchange (ETDEWEB)

    Anashin, V V; Arbuzov, V S; Blinov, G A; Veshcherevich, V G; Vobly, P D; Gorniker, E I; Zinevich, N I; Zinin, E I; Zubkov, N I; Kiselev, V A; Kollerov, E P; Kulipanov, G N; Matveev, Yu G; Medvedko, A S; Mezentsev, N A; Morgunov, L G; Petrov, V M; Petrov, S P; Repkov, V V; Roenko, V A; Skrinsky, A N; Sukhanov, S V; Tokarev, Yu I; Trakhtenberg, E M [AN SSSR, Novosibirsk. Inst. Yadernoj Fiziki

    1989-10-10

    In the last decade researches dealing with the creation of technology for X-ray lithography and for appropriate production equipment have been performed in many countries. The basic aim of these works is to provide a mass production of inexpensive devices with submicron structures (0.7-0.1 {mu}m). Bringing X-ray lithographic technology into commercial practice necessitates to design and build a dedicated SR source for the electronic industry. The use of superconducting bending magnets with 40-70 kG field strength enables the storage ring circumference to be reduced by a factor of 2-5 and the injection energy by a factor of 3-4 as compared to the conventional designs of storage rings. In the present paper we consider a storage ring which was designed for a maximum energy of 600 MeV, with 60 kG field strength in its bending magnets and 10 m circumference. The critical SR wavelength is 8.6 A. The electrons are injected into the storage ring at 50-60 MeV and the maximum stored current is assumed to be equal to 0.3 A. (orig.).

  7. Vacuum system for the NIJI-III compact storage ring

    International Nuclear Information System (INIS)

    Miura, F.; Tsutsui, Y.; Takada, H.

    1990-01-01

    The NIJI-III is a compact storage ring measuring about 15 m in circumference with four superconducting bending magnets. It is under development as a synchrotron light source for X-ray lithography with a stored beam current of 200 mA at a stored beam current of 200 mA at a stored energy level of 615 MeV. The vacuum system is designed to attain a pressure of less than 1 x 10 -9 Torr at beam storage. The compact ring design makes it difficult to install a large number of pumps able to satisfy the required pumping speed. For the purpose of realizing a high pumping speed, a cryopump as a result of cooling the superconducting magnet duct wall to the liquid helium (LHe) temperature is adopted, as a result the total pumping speed to 2.8 x 10 4 l/s is obtained. (author)

  8. Injection system of compact SR light source 'AURORA'

    International Nuclear Information System (INIS)

    Takayama, Takeshi; Yano, Takashi; Sasaki, Yasushi; Yasumitsu, Naoki

    1991-01-01

    A half-integer-resonance injection method is introduced for a superconducting SR-ring of 1 m orbit diameter, which is made of a weak focussing single-body magnet. The present method makes it possible to inject an electron beam of an energy of as high as 150 MeV into the ring of a magnetic field strength of 1 T. Several new injection devices are introduced in order to guide the beam under the strong magnetic fringing field, and to excite the half-integer-resonance. The field index of 0.73 is selected for the half-integer-resonance injection. The field index of 0.35 at the maximum magnetic field strength of 4.3 T is to get a sufficiently long quantum lifetime. A new device named resonance jumper is used to pass quickly several resonances of betatron motion without beam loss. The resonances occur when the magnetic field is ramped up and the field index decreases from 0.73 to 0.35. The injection devices except the inflector are air-core magnets in order to work in the strong magnetic field. In November of 1989, the beam was successfully injected and stored. The injection devices and the half-integer-resonance injection method were established. (author)

  9. A Compact Annular Ring Microstrip Antenna for WSN Applications

    Directory of Open Access Journals (Sweden)

    Daihua Wang

    2012-06-01

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

  10. Development and status of superconducting SR-ring

    International Nuclear Information System (INIS)

    Toyota, Eijiro; Tomimasu, Takio.

    1991-01-01

    Recently, attention has been paid to synchrotron radiation as a powerful tool for material science research, and for the most advanced research, stronger beam is sought for, therefore, large scale synchrotron radiation source facilities are going to be constructed. In contrast with the move toward large scale like this, effort is exerted to reduce the size by using superconductivity and to utilize for industries. Especially Japan precedes most in this field, and has already succeeded in the beam generation. This move to reduce size and pursue economic efficiency is noteworthy as that of supplementing the trend to large scale on the other hand, and its outline is explained. Synchrotron radiation means the strong beam emitted in tangential direction when the electrons or positrons moving at the velocity close to the velocity of light are bent in a magnetic field. The device which stably generates synchrotron radiation is an electron storage ring. The features of synchrotron radiation are explained. The history of synchrotron radiation research, the trend of development of superconducting synchrotron radiation ring, the actual examples of superconducting SR rings and their problems are described. (K.I.)

  11. Compact electron storage ring JESCOS with normalconducting or superconducting magnets for X-ray lithography

    International Nuclear Information System (INIS)

    Anton, F.; Klein, U.; Krischel, D.; Anderberg, B.

    1992-01-01

    The layouts of a normal conducting electron storage ring and a storage ring with superconducting bending magnets are presented. The storage rings have a critical wavelength of 1 nm and are designed as compact sources for X-ray lithography. Each ring fits into a shielded room with a diameter of 14 m. (author) 3 refs.; 5 figs.; 1 tab

  12. Acceleration of compact torus plasma rings in a coaxial rail-gun

    International Nuclear Information System (INIS)

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

    1985-01-01

    We discuss here theoretical studies of magnetic acceleration of Compact Torus plasma rings in a coaxial, rail-gun accelerator. The rings are formed using a magnetized coaxial plasma gun and are accelerated by injection of B/sub theta/ flux from an accelerator bank. After acceleration, the rings enter a focusing cone where the ring is decelerated and reduced in radius. As the ring radius decreases, the ring magnetic energy increases until it equals the entering kinetic energy and the ring stagnates. Scaling laws and numerical calculations of acceleration using a O-D numerical code are presented. 2-D, MHD simulations are shown which demonstrate ring formation, acceleration, and focusing. Finally, 3-D calculations are discussed which determine the ideal MHD stability of the accelerated ring

  13. Acceleration of compact torus plasma rings in a coaxial rail-gun

    International Nuclear Information System (INIS)

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

    1986-01-01

    They discuss here theoretical studies of magnetic acceleration of Compact Torus plasma rings in a coaxial, rail-gun accelerator. The rings are formed using a magnetized coaxial plasma gun and are accelerated by injection of B/sub Theta/ flux from an accelerator bank. After acceleration, the rings enter a focusing cone where the ring is decelerated and reduced in radius. As the ring radius decreases, the ring magnetic energy increases until it equals the entering kinetic energy and the ring stagnates. Scaling laws and numerical calculations of acceleration using a O-D numerical code are presented. 2-D, MHD simulations are shown which demonstrate ring formation, acceleration, and focusing. Finally, 3-D calculations are discussed which determine the ideal MHD stability of the accelerated ring

  14. On the number of light rings in curved spacetimes of ultra-compact objects

    Science.gov (United States)

    Hod, Shahar

    2018-01-01

    In a very interesting paper, Cunha, Berti, and Herdeiro have recently claimed that ultra-compact objects, self-gravitating horizonless solutions of the Einstein field equations which have a light ring, must possess at least two (and, in general, an even number of) light rings, of which the inner one is stable. In the present compact paper we explicitly prove that, while this intriguing theorem is generally true, there is an important exception in the presence of degenerate light rings which, in the spherically symmetric static case, are characterized by the simple dimensionless relation 8 πrγ2 (ρ +pT) = 1 [here rγ is the radius of the light ring and { ρ ,pT } are respectively the energy density and tangential pressure of the matter fields]. Ultra-compact objects which belong to this unique family can have an odd number of light rings. As a concrete example, we show that spherically symmetric constant density stars with dimensionless compactness M / R = 1 / 3 possess only one light ring which, interestingly, is shown to be unstable.

  15. Recommendation for the Feasibility of more Compact LC Damping Rings

    CERN Document Server

    Pivi, M.T.F.; Demma, T.; Guiducci, S.; Suetsugu, Y.; Shibata, K.; Ohmi, K.; Dugan, G.; Palmer, M.; Crittenden, J.A.; Harkay, K.; Boon, L.; Furman, M.A.; Venturini, M.; Celata, C.; Malyshev, O.B.; Papaphilippou, I.

    2010-01-01

    As part of the international Linear Collider (ILC) collaboration, we have compared the electron cloud (EC) effect for different Damping Ring (DR) designs respectively with 6.4 km and 3.2 km circumference and investigated the feasibility of the shorter damping ring with respect to the electron cloud build-up and related beam instabilities. The studies for a 3.2 km ring were carried out with beam parameters of the ILC Low Power option. A reduced damping ring circumference has been proposed for the new ILC baseline design SB2009 and would allow considerable reduction of the number of components, wiggler magnets and costs. We discuss the impact of the proposed operation of the ILC at high repetition rate 10 Hz and address the necessary modifications for the DRs. We also briefly discuss the plans for future studies including the luminosity upgrade option with shorter bunch spacing, the evaluation of mitigation techniques and the integration of the CesrTA results into the Damping Ring design

  16. Recommendation for the Feasibility of more Compact LC Damping Rings

    International Nuclear Information System (INIS)

    Pivi, M.T.F.; Wang, L.; Demma, T.; Guiducci, S.; Suetsugu, Y.; Shibata, K.; Ohmi, K.; Dugan, G.; Palmer, M.; Crittenden, J.A.; Harkay, K.; Boon, L.; Furman, M.A.; Venturini, M.; Celata, C.; Malyshev, O.B.; Papaphilippou, I.

    2010-01-01

    As part of the international Linear Collider (ILC) collaboration, we have compared the electron cloud (EC) effect for different Damping Ring (DR) designs respectively with 6.4 km and 3.2 km circumference and investigated the feasibility of the shorter damping ring with respect to the electron cloud build-up and related beam instabilities. The studies for a 3.2 km ring were carried out with beam parameters of the ILC Low Power option. A reduced damping ring circumference has been proposed for the new ILC baseline design SB2009 (1) and would allow considerable reduction of the number of components, wiggler magnets and costs. We discuss the impact of the proposed operation of the ILC at high repetition rate 10 Hz and address the necessary modifications for the DRs. We also briefly discuss the plans for future studies including the luminosity upgrade option with shorter bunch spacing, the evaluation of mitigation techniques and the integration of the CesrTA results into the Damping Ring design.

  17. Workshop on compact storage ring technology: applications to lithography

    International Nuclear Information System (INIS)

    1986-01-01

    Project planning in the area of x-ray lithography is discussed. Three technologies that are emphasized are the light source, the lithographic technology, and masking technology. The needs of the semiconductor industry in the lithography area during the next decade are discussed, particularly as regards large scale production of high density dynamic random access memory devices. Storage ring parameters and an overall exposure tool for x-ray lithography are addressed. Competition in this area of technology from Germany and Japan is discussed briefly. The design of a storage ring is considered, including lattice design, magnets, and beam injection systems

  18. Compact high-efficiency vortex beam emitter based on a silicon photonics micro-ring

    DEFF Research Database (Denmark)

    Li, Shimao; Ding, Yunhong; Guan, Xiaowei

    2018-01-01

    Photonic integrated devices that emit vortex beam carrying orbital angular momentum are becoming key components for multiple applications. Here we propose and demonstrate a high-efficiency vortex beam emitter based on a silicon micro-ring resonator integrated with a metal mirror. Such a compact...

  19. Results from the RACE [Ring ACceleration Experiment] Compact Torus Acceleration Experiment

    International Nuclear Information System (INIS)

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

    1987-06-01

    RACE (Ring ACceleration Experiment) is a proof-of-principle experiment aimed at demonstrating acceleration of magnetically confined compact torus plasma rings to directed kinetic energies well in excess of their magnetic and thermal energies. In the course of the first year of operation the following have been observed: successful formation of rings in the RACE geometry; acceleration of rings with large forces, F/sub accelerate/ ∼F/sub equilibrium/ without apparent degradation of the ring structure; peak velocities of ≅2.5 x 10 8 cm/sec; acceleration efficiency of >30% at speeds of 1.5 x 10 8 cm/sec inferred from trajectory and capacitor bank data; kinetic to magnetic energy ratios ∼10 were observed. Experiments in the near future will be aimed at confirmation of the mass/energy measurements by calorimetry and direct density measurements

  20. Operation with the low momentum compaction factor on an electron storage ring

    International Nuclear Information System (INIS)

    Hama, H.; Yamazaki, J.; Nakamura, E.; Isoyama, G.

    1994-01-01

    We have studied quasi-isochronous operation with the low momentum compaction factor to reduce the bunch length of the electron beam on the UVSOR storage ring. The momentum compaction factor α was reduced by changing the dispersion function in the bending magnets. Though effect of the second order α becomes dominant in the very low α region, we could compensate it by reducing strength of the focusing sextupole magnets. The momentum compaction factor was reduced to less than one hundredth with respect to the ordinary value. Using a streak camera, we measured the very short bunch, and confirmed the storage ring was operated nearly isochronously. The beam current dependence of the bunch length was also measured. The bunch lengthening was interpreted by potential-well distortion theory with a constant value of the effective longitudinal coupling impedance over the wide range of α. (author)

  1. Distribution of ^<90>Sr and ^<137>Cs in Annual Tree Rings of Japanese Cedar, Cryptomeria Japonica D.Don.

    OpenAIRE

    千木良, みどり; 斎藤, 裕子; 木村, 幹; MIDORI, CHIGIRA; YUKO, SAITO; KAN, KIMURA; 青山学院大学理工学部; 青山学院大学理工学部; 青山学院大学理工学部; Department of Chemistry, College of Science and Engineering, Aoyama Gakuin University; Department of Chemistry, College of Science and Engineering, Aoyama Gakuin University; Department of Chemistry, College of Science and Engineering, Aoyama Gakuin University

    1988-01-01

    The contents of ^Sr and ^Cs in two samples of Japanese cedar from Takao and Tsukui districts were determined in tree rings cut into segments representing steps of 5 years of growth. ^Sr in both cedar samples and ^Cs in the Tsukui cedar sample were determined after ashing and chemical isolation, while ^Cs in the Takao sample was directly determined from the sample ash. The distribution of ^Sr fallout in tree rings suggests that ^Sr had given a rather direct effect and showed no significant tra...

  2. Effect of additives on the orientation of magnetic Sr-ferrite powders in powder injection molded compacts

    Energy Technology Data Exchange (ETDEWEB)

    Cho, T.S. [Sangju National Unviersity, Sangju (Korea); Jeung, W.Y. [Korea Institute of Science and Technology, Seoul (Korea)

    2001-03-01

    The effect of additives on the orientation of magnetic Sr-ferrite powders has been studied during powder injection molding under applied magnetic field for fabricating multi=pole anisotropic sintered Sr-ferrite magnets. The orientation of the Sr-ferrite powders depends sensitively on the fluidity of powder-binder mixture, related to the binder additives and the injection molding temperature, and the magnetic field intensity. The orientation of Sr-ferrite powders is good for the compacts with stearic acid added in the binder system of paraffin wax/ carnauba wax/HDPE, but it is poor of the compacts with silane coupling agent added. The orientation of sr-ferrites higher than 80% is achieved at the following useful conditions; apparent viscosity lower than 2500 poise in 1000 sec {sup -1} shear rate and applied magnetic field higher than 4 kOe. (author). 15 refs., 1 tab., 6 figs.

  3. A compact 5.5 GHz band-rejected UWB antenna using complementary split ring resonators.

    Science.gov (United States)

    Islam, M M; Faruque, M R I; Islam, M T

    2014-01-01

    A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs) is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12 GHz, with a compact dimension of 22 × 26 mm(2), and VSWR WLAN band.

  4. Compact near-IR and mid-IR cavity ring down spectroscopy device

    Science.gov (United States)

    Miller, J. Houston (Inventor)

    2011-01-01

    This invention relates to a compact cavity ring down spectrometer for detection and measurement of trace species in a sample gas using a tunable solid-state continuous-wave mid-infrared PPLN OPO laser or a tunable low-power solid-state continuous wave near-infrared diode laser with an algorithm for reducing the periodic noise in the voltage decay signal which subjects the data to cluster analysis or by averaging of the interquartile range of the data.

  5. Distribution of 90Sr and 137Cs in annual tree rings of Japanese cedar, Cryptomeria Japonica D. Don

    International Nuclear Information System (INIS)

    Chigira, Midori; Saito, Yuko; Kimura, Kan

    1988-01-01

    The contents of 90 Sr and 137 Cs in two samples of Japanese cedar from Takao and Tsukui districts were determined in tree rings cut into segments representing steps of 5 years of growth. 90 Sr in both cedar samples and 137 Cs in the Tsukui cedar sample were determined after ashing and chemical isolation, while 137 Cs in the Takao sample was directly determined from the sample ash. The distribution of 90 Sr fallout in tree rings suggests that 90 Sr had given a rather direct effect and showed no significant translocation from sapwood to heartwood, whereas 137 Cs tends to concentrate in heartwood irrespective of the effect of the fallout. Average contents of 90 Sr and 137 Cs were 22 and 9.4 pCi/kg in the Takao sample (9.61 kg air dried) and were 23 and 12 in the Tsukui (4.71 kg air dried) in 1982. (author)

  6. Compact circularly polarized truncated square ring slot antenna with suppressed higher resonances.

    Directory of Open Access Journals (Sweden)

    Mursyidul Idzam Sabran

    Full Text Available This paper presents a compact circularly polarized (CP antenna with an integrated higher order harmonic rejection filter. The proposed design operates within the ISM band of 2.32 GHz- 2.63 GHz and is suitable for example for wireless power transfer applications. Asymmetrical truncated edges on a square ring create a defected ground structure to excite the CP property, simultaneously realizing compactness. It offers a 50.5% reduced patch area compared to a conventional design. Novel stubs and slot shapes are integrated in the transmission line to reduce higher (up to the third order harmonics. The proposed prototype yields a -10 dB reflection coefficient (S11 impedance bandwidth of 12.53%, a 3 dB axial ratio bandwidth of 3.27%, and a gain of 5.64 dBi. Measurements also show good agreement with simulations.

  7. A Compact 5.5 GHz Band-Rejected UWB Antenna Using Complementary Split Ring Resonators

    Directory of Open Access Journals (Sweden)

    M. M. Islam

    2014-01-01

    Full Text Available A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12 GHz, with a compact dimension of 22 × 26 mm2, and VSWR < 2, observing band elimination of 5.5 GHz WLAN band.

  8. A Low-Profile and Compact Split-Ring Antenna with Horizontally Polarized Omnidirectional Radiation

    Directory of Open Access Journals (Sweden)

    Kittima Lertsakwimarn

    2015-01-01

    Full Text Available This paper presents a low-profile and compact printed antenna having an omnidirectional radiation pattern with horizontal polarization to the ground. The proposed antenna consists of an inner small fed ring, an outer coupled split ring, and a ground plane. The overall dimension of the proposed antenna is 45 mm × 50.5 mm × 11.6 mm (0.138λ0 × 0.155λ0 × 0.036λ0. The −10-dB S11 of the antenna covers the 920-MHz RFID band, and the gain is about 1.45 dBi in the parallel direction to the ground plane. The measured results show good agreements with the simulated results. Furthermore, the reasons for the low-profile structure and the omnidirectional radiation pattern are also discussed.

  9. Compact Dual-Band Bandpass Filter Using Stubs Loaded Ring Resonator

    Science.gov (United States)

    Xu, Jin

    2016-01-01

    This paper presents a novel second-order dual-band bandpass filter (BPF) by using proposed stubs loaded ring resonator. The resonant behavior of proposed stubs loaded ring resonator is analyzed by even-/odd-mode method, which shows its multiple-mode resonant characteristic. Parameters sweep is done so as to give the design guidelines. As an example, a second-order dual-band BPF operating at 1.8/5.2 GHz for GSM and WLAN applications is designed, fabricated and measured. The fabricated filter has a very compact size of 0.05λg×0.15λg. Measured results also show that the proposed dual-band BPF has a better than 20 dB rejection upper stopband from 5.47 GHz to 12.56 GHz. Good agreement is shown between the simulated and measured results.

  10. Compact light-emitting diode lighting ring for video-assisted thoracic surgery.

    Science.gov (United States)

    Lu, Ming-Kuan; Chang, Feng-Chen; Wang, Wen-Zhe; Hsieh, Chih-Cheng; Kao, Fu-Jen

    2014-01-01

    In this work, a foldable ring-shaped light-emitting diode (LED) lighting assembly, designed to attach to a rubber wound retractor, is realized and tested through porcine animal experiments. Enabled by the small size and the high efficiency of LED chips, the lighting assembly is compact, flexible, and disposable while providing direct and high brightness lighting for more uniform background illumination in video-assisted thoracic surgery (VATS). When compared with a conventional fiber bundle coupled light source that is usually used in laparoscopy and endoscopy, the much broader solid angle of illumination enabled by the LED assembly allows greatly improved background lighting and imaging quality in VATS.

  11. Compact light-emitting diode lighting ring for video-assisted thoracic surgery

    Science.gov (United States)

    Lu, Ming-Kuan; Chang, Feng-Chen; Wang, Wen-Zhe; Hsieh, Chih-Cheng; Kao, Fu-Jen

    2014-10-01

    In this work, a foldable ring-shaped light-emitting diode (LED) lighting assembly, designed to attach to a rubber wound retractor, is realized and tested through porcine animal experiments. Enabled by the small size and the high efficiency of LED chips, the lighting assembly is compact, flexible, and disposable while providing direct and high brightness lighting for more uniform background illumination in video-assisted thoracic surgery (VATS). When compared with a conventional fiber bundle coupled light source that is usually used in laparoscopy and endoscopy, the much broader solid angle of illumination enabled by the LED assembly allows greatly improved background lighting and imaging quality in VATS.

  12. The suitability of annual tree growth rings as environmental archives: Evidence from Sr, Nd, Pb and Ca isotopes in spruce growth rings from the Strengbach watershed

    Science.gov (United States)

    Stille, Peter; Schmitt, Anne-Désirée; Labolle, François; Pierret, Marie-Claire; Gangloff, Sophie; Cobert, Florian; Lucot, Eric; Guéguen, Florence; Brioschi, Laure; Steinmann, Marc; Chabaux, François

    2012-05-01

    The combination of the Sr, Nd and Pb isotope systems, recognized as tracers of sources, with the Ca isotope system, known to reveal biology-related fractionations, allowed us to test the reliability of spruce (Picea abies) growth rings as environmental archives through time (from 1916 to 1983) in a forest ecosystem affected by acid atmospheric deposition. Sr and Pb isotopes have already been applied in former tree-ring studies, whereas the suitability of Nd and Ca isotope systems is checked in the present article. Our Sr and Nd isotope data indicate an evolution in the cation origin with a geogenic origin for the oldest rings and an atmospheric origin for the youngest rings. Ca isotopes show, for their part, an isotopic homogeneity which could be linked to the very low weathering flux of Ca. Since this flux is weak the spruces' root systems have pumped the Ca mainly from the organic matter-rich top-soil over the past century. In contrast, the annual growth rings studied are not reliable and suitable archives of past Pb pollution.

  13. A Dynamic Momentum Compaction Factor Lattice for Improvements to Stochastic Cooling in Storage Rings

    Energy Technology Data Exchange (ETDEWEB)

    Olivieri, David Nicholas [Massachusetts U., Amherst

    1996-01-01

    A dynamic momentum compaction factor, also referred to as a dynamic $\\Delta \\gamma \\tau$, lattice for the FNAL Antiproton Source Debuncher Storage Ring is studied, both theoretically and experimentally, for the purpose of improving stochastic precooling, and hence, improving the global antiproton production and stacking performance. A dynamic $\\Delta \\gamma \\tau$ lattice is proposed due to the competing requirements inherent within the Debuncher storage ring upon $\\gamma \\tau$· Specifically, the Debuncher storage ring performs two disparate functions, $(i)$ accepting and debunching a large number of $\\overline{p}$s/pulse at the outset of the production cycle, which would perform ideally with a large value of $\\gamma\\tau$, and $(ii)$ subsequently employing stochastic cooling throughout the remainder of the $\\overline{p}$ production cycle for improved transfer and stacking efficiency into the Accumulator, for which a small value $\\gamma \\tau$ is ideal in order to reduce the diffusive heating caused by the mixing factor. In the initial design of the Debuncher optical lattice, an intermediate value of $\\gamma \\tau$ was chosen as a compromise between the two functional requirements. The goal of the thesis is to improve stochastic precooling by changing $\\gamma \\tau$ between two desired values during each p production cycle. In particular, the dynamic $\\Delta \\gamma \\tau$ lattice accomplishes a reduction in $\\gamma \\tau$, and hence the mixing factor, through an uniform increase to the dispersion throughout the arc sections of the storage ring. Experimental measurements of cooling rates and system performance parameters, with the implementation of the dynamic $\\Delta \\gamma \\tau$ lattice, are in agreement with theoretical predictions based upon a detailed integration of the stochastic cooling Fokker Planck equations. Based upon the consistency between theory and experiment, predictions of cooling rates are presented for future operational

  14. Compact and Wide Stopband Lowpass Filter Using Open Complementary Split Ring Resonator and Defected Ground Structure

    Directory of Open Access Journals (Sweden)

    S. S. Karthikeyan

    2015-09-01

    Full Text Available A compact (0.16 λg x 0.08 λg and wide stop¬band lowpass filter design using open complementary split ring resonator (OCSRR and defected ground structure (DGS is presented in this paper. Low pass filter is con-structed using two cascaded stages of OCSRR. Since the rejection bandwidth of the OCSRR is narrow, tapered dumbbell shaped DGS section is placed under the OCSRR to enhance the bandwidth. The cutoff frequency (fc of the proposed lowpass filter is 1.09 GHz. The rejection band¬width of the filter covers the entire ultra wideband spec¬trum. Hence the spurious passband suppression is achieved up to 10 fc. The designed filter has been fabri¬cated and validated by experimental results

  15. A lattice with larger momentum compaction for the NLC main damping rings

    International Nuclear Information System (INIS)

    Wolski, Andrzej; Raubenheimer, Tor O.; Woodley, Mark; Wu, Juhao

    2004-01-01

    Previous lattice designs for the Next Linear Collider Main Damping Rings [1] have met the specifications for equilibrium emittance, damping rate and dynamic aperture. Concerns about the effects of the damping wiggler on the beam dynamics [2] led to the aim of reducing the total length of the wiggler to a minimum consistent with the required damping rate, so high-field dipoles were used to provide a significant energy loss in the arcs. However, recent work has shown that the wiggler effects may not be as bad as previously feared. Furthermore, other studies have suggested the need for an increased momentum compaction (by roughly a factor of four) to raise the thresholds of various collective effects. We have therefore developed a new lattice design in which we increase the momentum compaction by reducing the field strength in the arc dipoles, compensating the loss in damping rate by increasing the length of the wiggler. The new lattice again meets the specifications for emittance, damping rate and dynamic aperture, while having the benefit of significantly higher thresholds for a number of instabilities

  16. Distribution of 90Sr in the tree rings of a Japanese cedar exposed to the black rain from the Nagasaki atomic bomb

    International Nuclear Information System (INIS)

    Katayama, Y.; Nagai, M.; Aoki, T.; Nagatomo, T.; Okada, N.

    2006-01-01

    Cedar sample was collected at the black rain area in Nagasaki city. A clear peak of 90 Sr/Sr was observed in the 1924-1925 rings. To investigate the mobility of Sr in a cedar tree stem, strontium chloride solution was injected into a living tree, and the distribution profiles of Sr in the stem at 8 months later were determined. The strontium moves radially through the sapwood of a cedar stem but that it almost stops at the heartwood. It was concluded that the peak in the 1924-1925 rings was due to the black rain from the Nagasaki atomic bomb. (author)

  17. Growth tree rings as bioindicator of environmental pollution employing SR-TXRF

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Bruna Fernanda; Moreira, Silvana [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: silvana@fec.unicamp.br; Vives, Ana Elisa Sirito de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil)]. E-mail: aesvives@unimep.br; Medeiros, Jean Gabriel da Silva; Tomazello Filho, Mario [Universidade de Sao Paulo (USP), SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]. E-mail: jeangm@esalq.usp.br; Zucchi, Orgheda Luiza Araujo Domingues [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br

    2007-07-01

    The present work has the aim to evaluate the use of tree ring as a bioindicator of the environmental pollution in urban and industrial areas. The sampling was made in a area located at the Forest Park, in the Bauru city, Sao Paulo state/Brazil. The area was contaminated by battery industries residues, which was interdicted by the Environmental Control Agency of the Sao Paulo State (CETESB), on March, 2002. Trees of Copaifera langsdorffi L. species were sampling in two different sites. The first one is near to the industry and other site 1700 m far. Synchrotron Radiation Total Reflection X-Ray Fluorescence technique (SR-TXRF) was employed to identify and quantify the metals of toxicological importance in the wood samples. The analysis was performed in the Brazilian Synchrotron Light Laboratory using a white beam for excitation and a hyperpure germanium detector for X-ray detection. In wood samples Cr, Co, Ni, Cu, Zn, As and Pb were determined. (author)

  18. Growth tree rings as bioindicator of environmental pollution employing SR-TXRF

    International Nuclear Information System (INIS)

    Faria, Bruna Fernanda; Moreira, Silvana; Medeiros, Jean Gabriel da Silva; Tomazello Filho, Mario; Zucchi, Orgheda Luiza Araujo Domingues

    2007-01-01

    The present work has the aim to evaluate the use of tree ring as a bioindicator of the environmental pollution in urban and industrial areas. The sampling was made in a area located at the Forest Park, in the Bauru city, Sao Paulo state/Brazil. The area was contaminated by battery industries residues, which was interdicted by the Environmental Control Agency of the Sao Paulo State (CETESB), on March, 2002. Trees of Copaifera langsdorffi L. species were sampling in two different sites. The first one is near to the industry and other site 1700 m far. Synchrotron Radiation Total Reflection X-Ray Fluorescence technique (SR-TXRF) was employed to identify and quantify the metals of toxicological importance in the wood samples. The analysis was performed in the Brazilian Synchrotron Light Laboratory using a white beam for excitation and a hyperpure germanium detector for X-ray detection. In wood samples Cr, Co, Ni, Cu, Zn, As and Pb were determined. (author)

  19. Optics Design and Performance of an Ultra-Low Emittance Damping Ring for the Compact Linear Collider

    CERN Document Server

    Korostelev, M S

    2006-01-01

    A high-energy (0.5-3.0 TeV centre of mass) electron-positron Compact Linear Collider (CLIC) is being studied at CERN as a new physics facility. The design study has been optimized for 3 TeV centre-of-mass energy. Intense bunches injected into the main linac must have unprecedentedly small emittances to achieve the design luminosity 1035cm-2s-1 required for the physics experiments. The positron and electron bunch trains will be provided by the CLIC injection complex. This thesis describes an optics design and performance of a positron damping ring developed for producing such ultra-low emittance beam. The linear optics of the CLIC damping ring is optimized by taking into account the combined action of radiation damping, quantum excitation and intrabeam scattering. The required beam emittance is obtained by using a TME (Theoretical Minimum Emittance) lattice with compact arcs and short period wiggler magnets located in dispersionfree regions. The damping ring beam energy is chosen as 2.42 GeV. The lattice featu...

  20. Status of the variable momentum compaction storage ring experiment in SPEAR

    International Nuclear Information System (INIS)

    Tran, P.; Amiry, A.; Pellegrini, C.

    1993-01-01

    Variable momentum compaction lattices have been proposed for electron-positron colliders and synchrotron radiation sources to control synchrotron tune and bunch length. To address questions of single particle stability limits, a study has been initiated to change the SPEAR lattice into a variable momentum compaction configuration for experimental investigation of the beam dynamics. In this paper, we describe a model-based method used to transform SPEAR from the injection lattice to the low momentum compaction configuration. Experimental observations of the process are reviewed

  1. Design of a compact polarizing beam splitter based on a photonic crystal ring resonator with a triangular lattice.

    Science.gov (United States)

    Yu, Tianbao; Huang, Jiehui; Liu, Nianhua; Yang, Jianyi; Liao, Qinghua; Jiang, Xiaoqing

    2010-04-10

    We propose and simulate a new kind of compact polarizing beam splitter (PBS) based on a photonic crystal ring resonator (PCRR) with complete photonic bandgaps. The two polarized states are separated far enough by resonant and nonresonant coupling between the waveguide modes and the microring modes. Some defect holes are utilized to control the beam propagation. The simulated results obtained by the finite-difference time-domain method show that high transmission (over 95%) is obtained and the polarization separation is realized with a length as short as 3.1 microm. The design of the proposed PBS can be flexible, thanks to the advantages of PCRRs.

  2. Microstructures and superconducting properties of Y-Ba-Cu and Bi-Sr-Ca-Cu oxide wires and coils prepared by the explosive compaction technique

    International Nuclear Information System (INIS)

    Hagino, S.; Suzuki, M.; Takeshita, T.; Takashima, K.; Tonda, H.

    1989-01-01

    It has been shown that explosive compaction technique can be used to densify metal, and ceramics powders and their mixtures. The authors discuss how they applied this technique to produce silver sheathed superconducting oxide wires and coils (Y-B-Cu-O and Bi-Sr-Ca-Cu-O). The wires and coils to be compacted were placed into metal tube and the tube was filled with SiC powder as a pressure propagating medium and the tube was compacted by a cylindrically axisymmetric method. The wires and coils compacted were then heat-treated in order to improve grain boundary connections of superconducting oxide crystalline grains. The oxide cores heat-treated were seen to be very dense, and a part of a Y-Ba-Cu oxide coil which was heat-treated optimally was found to have a critical current density higher than 13,000A/cm 2 at 77K

  3. Superconducting glass-ceramics in BiSrCaCu2Al0.5Ox---Comparison between rod and powder compacted specimens

    International Nuclear Information System (INIS)

    Hirata, K.; Abe, Y.

    1991-01-01

    Superconducting properties are studied for glass-ceramics which were prepared by reheating glass rods and the glass powder compacts in the BiSrCaCu 2 Al 0.5 O x system, respectively. The glass-ceramic rod specimens obtained by reheating rod glass at 800--830 degree C for 50 h have a T c (R=0) of 85 K, while the disk specimens obtained by reheating the powered glass compacts in the same way do not exhibit superconductivity above 77 K. This difference in superconductivity between the specimens is discussed in terms of crystallization process and the amount of oxygen absorption of the specimens during heating

  4. Compact 6 dB Two-Color Continuous Variable Entangled Source Based on a Single Ring Optical Resonator

    Directory of Open Access Journals (Sweden)

    Ning Wang

    2018-02-01

    Full Text Available Continuous-variable entangled optical beams at the degenerate wavelength of 0.8 μm or 1.5 μm have been investigated extensively, but separately. The two-color entangled states of these two useful wavelengths, with sufficiently high degrees of entanglement, still lag behind. In this work, we analyze the various limiting factors that affect the entanglement degree. On the basis of this, we successfully achieve 6 dB of two-color quadrature entangled light beams by improving the escape efficiency of the nondegenerate optical amplifier, the stability of the phase-locking servo system, and the detection efficiency. Our entangled source is constructed only from a single ring optical resonator, and thus is highly compact, which is suitable for applications in long-distance quantum communication networks.

  5. Coherent synchrotron radiation and bunch stability in a compact storage ring

    Directory of Open Access Journals (Sweden)

    Marco Venturini

    2005-01-01

    Full Text Available We examine the effect of the collective force due to coherent synchrotron radiation (CSR in an electron storage ring with small bending radius. In a computation based on time-domain integration of the nonlinear Vlasov equation, we find the threshold current for a longitudinal microwave instability induced by CSR alone. The model accounts for suppression of radiation at long wavelengths due to shielding by the vacuum chamber. In a calculation just above threshold, small ripples in the charge distribution build up over a fraction of a synchrotron period, but then die out to yield a relatively smooth but altered distribution with eventual oscillations in bunch length. The instability evolves from small noise on an initial smooth bunch of rms length much greater than the shielding cutoff.

  6. Multi-cell disk-and-ring tapered structure for compact RF linacs

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A.V.; Boucher, S.; Kutsaev, S. [RadiaBeam Systems LLC, 1713 Stewart Street, Santa Monica, CA 90404, US (United States); Hartzell, J. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); Savin, E. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation)

    2016-09-11

    A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

  7. Multi-cell disk-and-ring tapered structure for compact RF linacs

    International Nuclear Information System (INIS)

    Smirnov, A.V.; Boucher, S.; Kutsaev, S.; Hartzell, J.; Savin, E.

    2016-01-01

    A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

  8. A novel method of support vector machine to compute the resonant frequency of annular ring compact microstrip antennas

    Directory of Open Access Journals (Sweden)

    Ahmet Kayabasi

    2015-12-01

    Full Text Available An application of support vector machine (SVM to compute the resonant frequency at dominant mode TM11 of annular ring compact microstrip antennas (ARCMAs is presented in this paper. ARCMAs have some useful features; resonant modes can be adjusted by controlling the ratio of the outer radius to the inner radius. The resonant frequencies of 100 ARCMAs with varied dimensions and electrical parameters in accordance with UHF band covering GSM, LTE, WLAN, and WiMAX applications were simulated with IE3D™ which is a robust numerical electromagnetic computational tool. Then, the SVM model was built with simulation data and 88 simulated ARCMAs were operated for training and the remaining 12 ARCMAs were used for testing this model. The proposed model has been confirmed by comparing with the suggestions reported elsewhere via measurement data published earlier in the literature, and it has further validated on an ARCMA operating at 3 GHz fabricated in this study. The obtained results show that this technique can be successfully used to compute the resonant frequency of ARCMAs without involving any sophisticated methods. The novelty of the approach described here is to offer ease of designing the process using this method.

  9. External meeting - Geneva University: Proposal to measure the muon electric dipole moment with a compact storage ring at PSI

    CERN Multimedia

    2007-01-01

    GENEVA UNIVERSITY ECOLE DE PHYSIQUE Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet 1211 GENEVE 4 ? Tél : 022 379 62 73 - Fax: 022 379 69 92 Wednesday 16th May  2007 PARTICLE PHYSICS SEMINAR at 17:00 - Stückelberg Auditorium Proposal to measure the muon electric dipole moment with a compact storage ring at PSI by Dr. Thomas Schietinger, PSI - Villigen In the Standard Model, lepton electric dipole moments (EDM) arise from the CP-violating phase in the CKM matrix at the three-loop level only, resulting in values that are many orders of magnitude below the sensitivity of current and future experiments. Lepton EDMs therefore offer an excellent opportunity to discover unambiguous evidence for new CP-violating phases, as called for by the baryon-antibaryon asymmetry of the universe. The muon EDM is one of the least constrained fundamental properties in elementary particle physics. We propose to utilize the large available flux of polarized muons at PSI to search for a muon EDM ...

  10. Diffusion of I{sup -}, Cs{sup +}, and Sr{sup 2+} in compacted bentonite - Anion exclusion and surface diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Eriksen, T.E.; Jansson, Mats [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Nuclear Chemistry

    1996-11-01

    The diffusion of I, Cs and Sr ions in bentonite compacted to a dry density of 1.8 gr/cm{sup 3} and saturated with two groundwaters of different ionic strength have been studied experimentally using the through diffusion technique. The I{sup -} diffusivity and diffusion porosity were found to be concentration independent in the concentration range exp(-8) to exp(-2) mol/dm{sup 3}. The diffusion porosity, being only a fraction of the water porosity for normal groundwaters, is strongly ionic strength dependent due to anion exclusion. The dependence of the diffusion of Cs{sup +} and Sr{sup 2+} on the sorption intensity is accommodated by a model encompassing diffusion of the sorbed cations within the electrical double layer next to the mineral surface in addition to diffusion in the pore water. 18 refs, 12 figs.

  11. Study of radial distribution of 239,240Pu and 90Sr in annual tree rings and trunk bark of a 103 years old Norway spruce at four different heights above ground

    International Nuclear Information System (INIS)

    Holgye, Z.; Schlesingerova, E.

    2016-01-01

    Radial distribution of 239,240 Pu and 90 Sr originating from atmospheric nuclear tests in tree rings and trunk bark at heights of 1.3, 10, 18 and 22 m above ground was studied. 239,240 Pu activity concentrations in air dried tree ring samples (each containing 10 annual rings) at all heights were under detection limit of the used method. 90 Sr activity concentrations in tree ring samples ranged from 0.54 to 2.81 Bq kg -1 . 239,240 Pu and 90 Sr were present in the trunk bark. The paper presents data for 239,240 Pu and 90 Sr aggregated transfer factors to tree trunk. (author)

  12. Single-phase highly densified SrBi{sub 2}Ta{sub 2}O{sub 9} compacts produced by high-pressure sintering

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Altair Soria; Souza, Ricson Rocha de; Sousa, Vania Caldas de, E-mail: altair@if.ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre (Brazil)

    2016-07-01

    Full text: The development of high-performance lead-free piezoelectric ceramics is an important scientific and technological challenge, as environmental and health issues have imposed restrictions to the use of lead zirconate titanates, the most employed material in ferroelectric devices [1]. Strontium bismuth tantalate (SBT),SrBi{sub 2}Ta{sub 2}O{sub 9}, is an interesting alternative ferroelectric material as its polarization can be modified at low voltages and it shows limited polarization switching fatigue. However, the production of highly densified single-phase bulk SBT by conventional sintering procedures is strongly compromised by stoichiometric changes due to bismuth loss. In this work, high-pressure sintering has been exploited as an alternative procedure to obtain SBT highly-densified single-phase compacts. Using toroidal-type high-pressure chambers, samples were produced by reaction sintering of BiTaO{sub 4} and SrCO{sub 3} powders, mixed in the stoichiometric ratio corresponding to SrBi{sub 2}Ta{sub 2}O{sub 9}, at pressures of 2.5 GPa and 7.7 GPa, and temperatures up to 1250°C, during 10 min. X-ray diffraction and scanning electron microscopy associated to energy-dispersive X-ray spectroscopy were used to follow the phase composition and the microstructure evolution as a function of the processing conditions. A single-phase SBT compact, with a relative density of 93% and a homogeneous microstructure, was produced by sintering at 2.5 GPa/900°C [2]. References: [1] K. Panda, J. Mater. Sci. 44, 5049-5062 (2009). [2] Ricson R.Souza, Rejane K. Kirchner, Jose R. Jurado, Altair S. Pereira, Vania C. Sousa. Journal of Solid State Chemistry 233, 259-268 (2016). (author)

  13. Vibrational collapse of boroxol rings in compacted B2O3 glasses: a study of Raman scattering and low temperature specific heat

    Science.gov (United States)

    Carini, Giovanni, Jr.; Carini, Giuseppe; D’Angelo, Giovanna; Federico, Mauro; Romano, Valentino

    2018-05-01

    Low and high frequency Raman scattering of B2O3 glasses, compacted under GPa pressures, has been performed to investigate structural changes due to increasing atomic packing. Compacted glasses, annealed at ambient temperature and pressure, experience a time-dependent decrease of the density to a smaller constant value over a period of few months, displaying a permanent plastic deformation. Increasing densification determines a parallel and progressive decrease of the intensity of the Boson peak and the main band at 808 cm‑1, both these modes arising from localized vibrations involving planar boroxol rings (B3O6), the glassy units formed from three basic BO3 triangles. The 808 cm‑1 mode preserves its frequency, while the BP evidences a well-defined frequency increase. The high-frequency multicomponent band between 1200 and 1600 cm‑1 also changes with increasing densification, disclosing a decreasing intensity of the 1260 cm‑1 mode due to oxygen vibrations of BO3 units bridging boroxol rings. This indicates the gradual vibrational collapse of groups formed from rings connected by more complex links than a single bridging oxygen. The observed behaviours suggest that glass compaction causes severe deformation of boroxol rings, determining a decrease of groups which preserve unaltered their vibrational activity. Growing glass densification stiffens the network and leads to a decrease of the excess heat capacity over the Debye prediction below 20 K, which is not accounted for by the hardening of the elastic continuum. By using the low-frequency Raman scattering to determine the temperature dependence of the heat capacity, it has been evaluated the density of low-frequency vibrational states which discloses a significant reduction of excess modes with increasing density.

  14. A method for estimating time-frequency characteristics of compact binary mergers to improve searches for inspiral, merger and ring-down phases separately

    International Nuclear Information System (INIS)

    Hanna, Chad; Megevand, Miguel; Palenzuela, Carlos; Ochsner, Evan

    2009-01-01

    Recent advances in the description of compact binary systems have produced gravitational waveforms that include inspiral, merger and ring-down phases. Comparing results from numerical simulations with those of post-Newtonian, and related, expansions has provided motivation for employing post-Newtonian waveforms in near merger epochs when searching for gravitational waves and has encouraged the development of analytic fits to full numerical waveforms. Until searches employ full waveforms as templates, data analysts can still conduct separate inspiral, merger and ring-down searches. Improved knowledge about the end of the inspiral phase, the beginning of the merger and the ring-down frequencies will increase the efficiency of searches over each phase separately without needing the exact waveform. We will show that knowledge of the final spin, of which there are many theoretical models and analytic fits to simulations, may give an insight into the time-frequency properties of the merger. We also present implications on the ability to probe the tidal disruption of neutron stars through gravitational waves.

  15. Research and development activity for the construction of beam lines in spring-8 (a new 8GeV SR ring)

    International Nuclear Information System (INIS)

    Watanabe, Tsutomu; Ohno, Hideo; Iwasaki, Hitoshi; Sasaki, Teikichi

    1990-01-01

    A research and development activity for a new large-scale synchrotron radiation facility started in Japan in 1987. The Institute of Physical and Chemical Research (RIKEN) and Japan Atomic Energy Research Institute (JAERI) have been participating this project. In particular, a joint team for this SR project was formed in 1988 to perform efficient research and development activities in cooperation. The new facility is scheduled to be in normal operation in 1998. The maximum energy of the electron or positron beams in the storage ring (SPring-8) is planned to be 8 GeV. The present report particularly describes the beam line front-end, research and development of optical components, beam lines for radioactive materials, insertion devices, activities of the atomic physics group, double focusing monochromator for macromolecular crystallography, preceding studies on magnetic and Compton scattering, EXAFS and XANES studies of biopolymers, studies on surface properties, and applications. (N.K.)

  16. Technological study of ring and compact spinning systems for the manufacturing of slub fancy yarn under multiple slub variations and its effect on woven fabric

    International Nuclear Information System (INIS)

    Mahmood, N.; Iftikhar, M.; Mahmood, T.; Arshad, M.

    2009-01-01

    Textile technologies are continuously evolving with the objects both of increasing productivity and reducing processing costs, and of creating new products or variants of existing ones. Fashion, in the widest sense of the word mean fulfillment of consumer demands, through the ages constitutes a fundamental and conditional element for the whole textile industry. Fancy yarns present deliberate, decorative continuous or programmed effects of colour and/or form they are used to create some variation in the aesthetic appearance of a fabric. The drafting process is deliberately interrupted through the effect yarn device to produce slubs in the final yarn. The present research study was aimed to evaluate the quality characteristics of slub fancy yarn by changing slub length, inter slub distance, slub thickness and twist multiplier (T.M) at ring and compact spinning systems. (author)

  17. 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.

  18. Sorption of Sr, Co and Zn on illite: Batch experiments and modelling including Co in-diffusion measurements on compacted samples

    Science.gov (United States)

    Montoya, V.; Baeyens, B.; Glaus, M. A.; Kupcik, T.; Marques Fernandes, M.; Van Laer, L.; Bruggeman, C.; Maes, N.; Schäfer, T.

    2018-02-01

    Experimental investigations on the uptake of divalent cations (Sr, Co and Zn) onto illite (Illite du Puy, Le-Puy-en-Velay, France) were carried out by three different international research groups (Institute for Nuclear Waste Disposal, KIT (Germany), Group Waste & Disposal, SCK-CEN, (Belgium) and Laboratory for Waste Management, PSI (Switzerland)) in the framework of the European FP7 CatClay project. The dependence of solid-liquid distribution ratios (Rd values) on pH at trace metal conditions (sorption edges) and on the metal ion concentration (sorption isotherms) was determined in dilute suspensions of homo-ionic Na-illite (Na-IdP) under controlled N2 atmosphere. The experimental results were modelled using the 2 Site Protolysis Non Electrostatic Surface Complexation and Cation Exchange (2SPNE SC/CE) sorption model. The sorption of Sr depends strongly on ionic strength, while a rather weak pH dependence is observed in a pH range between 3 and 11. The data were modelled with cation exchange reactions, taking into account competition with H, K, Ca, Mg and Al, and surface complexation on weak amphotheric edge sites at higher pH values. The sorption of Co on Na-IdP, however, is strongly pH dependent. Cation exchange on the planar sites and surface complexation on strong and weak amphoteric edge sites were used to describe the Co sorption data. Rd values for Co derived from in-diffusion measurements on compacted Na-IdP samples (bulk-dry density of 1700 kg m-3) between pH 5.0 and 9.0 are in good agreement with the batch sorption data. The equivalence of both approaches to measure sorption was thus confirmed for the present test system. In addition, the results highlight the importance of both major and minor surface species for the diffusive transport behaviour of strongly sorbing metal cations. While surface complexes at the edge sites determine largely the Rd value, the diffusive flux may be governed by those species bound to the planar sites, even at low fractional

  19. Development of compact synchrotron radiation facilities TELL-TERAS, NIJI-I∼IV, at ETL

    International Nuclear Information System (INIS)

    Tomimasu, T.

    1990-01-01

    At the Electrotechnical Laboratory (ETL) four compact storage rings, TERAS, NIJI-I∼III, have been already constructed and a compact storage ring, NIJI-IV, with long straight sections for a free electron laser (FEL) experiment will be completed in 1990. The 0.8-GeV ETL storage ring is called TERAS; Tsukuba Electron Ring for Accelerating and Storage. TERAS has been operated since Oct. 1981 for researches on radiometric standards, dissociative photoionization, photodissociation of sulfur containing molecules, solid state physics, ULSI lithography, generation of polarized SR and gamma-rays and for FEL experiment using an transverse optical klystron (TOK). A 10-T three pole wiggler will be installed in 1991 at the straight section where the TOK is installed. NIJI-I is a 0.27-GeV compact ring. NIJI is a Japanese verb meaning 'rainbow' in English. It has been operated from Feb. 1986 to March 1989 for machine study of beam storage higher than 0.5 A at low energies below 0.15-GeV. NIJI-II is a 0.6-GeV conventional type compact ring. It has been operated in Aug. 1989 and will be used for chemical vapor deposition (CVD) and polarized SR experiments. NIJI-III is a 0.62-GeV superconducting type ring. It will be used for ULSI lithography experiments. Before the superconducting coils are installed, NIJI-III with conventional type magnets has been already constructed and operated in June 1989. NIJI-III with the superconducting ones is now operated in June 1990. NIJI-IV is a 0.5-GeV conventional type compact ring with straight sections longer than 7m where a 6.2-m long TOK is installed to achieve UV FEL experiment. (author)

  20. CHICSi - a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. II. Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Golubev, P.; Avdeichikov, V.; Carlen, L.; Jakobsson, B. E-mail: bo.jakobsson@kosufy.lu.se; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J

    2003-03-11

    We describe the detectors for identification of charged particles and fragments in CHICSi, a large solid angle multi-telescope system mounted inside an ultra-high vacuum (UHV), cluster-jet target chamber. CHICSi performs nuclear reaction experiments at storage rings. The telescopes consist of a first very thin, 10-14 {mu}m Si detector, a second 300 {mu}m (or possibly 500 {mu}m) ion implanted Si detector supplemented by a 6 mm GSO(Ce) scintillator read out by a photodiode (PD) or by a third 300 {mu}m Si detector. The telescopes provide full charge separation up to Z=17 and mass resolution up to A=9 in the energy range 0.7-60A MeV. The thin p-i-n diode detector, etched out from a 280 {mu}m Si wafer, and the GSO/PD detector, both exclusively developed for CHICSi, provide an energy resolution {<=}8%, while the standard 300 {mu}m detectors have {<=}2% energy resolution. Radiation stability of the Si detectors is confirmed up to an integrated flux of 10{sup 10} alpha particles. The GSO detector has 70% light collection efficiency with the optical coupling to the PD a simple open, 0.2 mm, gap. A new method, developed to perform absolute energy calibration for the GSO/PD detector is presented.

  1. CHICSi - a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. II. Detectors

    International Nuclear Information System (INIS)

    Golubev, P.; Avdeichikov, V.; Carlen, L.; Jakobsson, B.; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J.

    2003-01-01

    We describe the detectors for identification of charged particles and fragments in CHICSi, a large solid angle multi-telescope system mounted inside an ultra-high vacuum (UHV), cluster-jet target chamber. CHICSi performs nuclear reaction experiments at storage rings. The telescopes consist of a first very thin, 10-14 μm Si detector, a second 300 μm (or possibly 500 μm) ion implanted Si detector supplemented by a 6 mm GSO(Ce) scintillator read out by a photodiode (PD) or by a third 300 μm Si detector. The telescopes provide full charge separation up to Z=17 and mass resolution up to A=9 in the energy range 0.7-60A MeV. The thin p-i-n diode detector, etched out from a 280 μm Si wafer, and the GSO/PD detector, both exclusively developed for CHICSi, provide an energy resolution ≤8%, while the standard 300 μm detectors have ≤2% energy resolution. Radiation stability of the Si detectors is confirmed up to an integrated flux of 10 10 alpha particles. The GSO detector has 70% light collection efficiency with the optical coupling to the PD a simple open, 0.2 mm, gap. A new method, developed to perform absolute energy calibration for the GSO/PD detector is presented

  2. Effects of sintering and paste-baking conditions on PTCR characteristic of (Ba,Sr)TiO{sub 3} vacuum-sintered compact added with TiO{sub 2}(Ti) powder; TiO{sub 2}(ti) fun tenka (Ba,Sr)TiO{sub 3} shinku shoketsutai no PTCR tokusei ni oyobosu shoketsu oyobi paste yakitsuke joken no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.; Hayashi, K. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science

    1999-04-15

    The effects of sintering temperature (T{sub s}; 1,573 {approx} 1,748K) and time (t{sub s}; 0.6 {approx} 14.4ks) and paste-baking-temperature or heating temperature (T{sub b} or T{sub h}; 673 {approx} 1,273K; t{sub b} is 0.3ks) on PTCR characteristic were investigated for (Ba, Sr)TiO{sub 3} vacuum-sintered compact added with 3.9mass% TiO{sub 2}(Ti) powder of 12.5mass% TiO{sub 2}. The results obtained were as follows; (1) PTCR characteristic developed at all T{sub s} (t{sub s}=3.6ks, T{sub b}=853K). The electrical resistivity at room temperature ({rho}{sub rt}) showed a minimum value of 1.8 times 10{sup 2}ohmcenter dotcm and the {rho}{sub max}/{rho}{sub rt} showed a maximum value of about 10{sup 6} at 1,723K. (2)For all t{sub s} (T{sub s}=1,623K, T{sub b}=853K), PTCR characteristic developed. The {rho}{sub rt} showed a minimum value of 2.6 times 10{sup 3}ohmcenter dotcm at 7.2ks. (3) At T{sub b} above 823K (T{sub s}=1,623K, t{sub s}=3.6ks), PTCR characteristic developed. The {rho}{sub rt} showed a minimum value of 1.0 times 10{sup 3}ohmcenter dotcm. (4)The {rho}-T curve of (Ba, Sr)TiO{sub 3}+TiO{sub 2}(Ti) vacuum-sintered compact was affected more largely by T{sub s}, t{sub s} and T{sub b} than that of (Ba, Sr)TiO{sub 3} air-sintered compact. This was considered to be mainly due to the porous and fine gained microstructure in the former compact. (author)

  3. Coral growth rings and the temporal history of nuclear 14C/C and 90Sr/Sr in the surface ocean: Final report, June 1, 1982-December 31, 1984

    International Nuclear Information System (INIS)

    Broecker, W.S.; Cember, R.P.; Toggweiler, J.R.; Trumbore, S.E.; White, J.

    1987-08-01

    This report summarizes the history and scientific results of the Lamont-Doherty Geological Observatory coral radioisotope project. The report includes abstracts of works in the literature or in preparation resulting from the coral project and a complete listing of the radiocarbon and 90 Sr data measured in the course of the project. Also, some possible future research directions for the coral project are suggested

  4. Computer control system of the superconducting SR-light source ''Aurora''

    International Nuclear Information System (INIS)

    Yamada, H.

    1989-01-01

    The Aurora is a compact SR-light system optimized for x-ray lithography. The system includes a superconducting electron storage ring, a 150-MeV race track microtron as an injector, and light beamlines. The SR-ring features a single magnet body, in which the 650-MeV electron beam orbits a true circular trajectory of 1 m diameter. The computer control system developed for Aurora has a three-level hierarchical architecture. The top level is the Central Intelligence System, and the second an Autonomic Control System (ACS). The bottom is an assembly of distributed local controllers linked to the ACS level through optical fibers. This system provides fully automatic and remote operation, and a powerful machine study capability through the associated man--machine console and the interpretive operation language

  5. Computer control system of the superconducting SR-light source ``Aurora''

    Science.gov (United States)

    Yamada, Hironari

    1989-07-01

    The Aurora is a compact SR-light system optimized for x-ray lithography. The system includes a superconducting electron storage ring, a 150-MeV race track microtron as an injector, and light beamlines. The SR-ring features a single magnet body, in which the 650-MeV electron beam orbits a true circular trajectory of 1 m diameter. The computer control system developed for Aurora has a three-level hierarchical architecture. The top level is the Central Intelligence System, and the second an Autonomic Control System (ACS). The bottom is an assembly of distributed local controllers linked to the ACS level through optical fibers. This system provides fully automatic and remote operation, and a powerful machine study capability through the associated man-machine console and the interpretive operation language.

  6. The Achkal Oligocene ring complex: Sr, Nd, Pb evidence for transition between tholeiitic and alkali cenozoic magmatism in Central Hoggar (South Algeria)

    International Nuclear Information System (INIS)

    Maza, M.; Dautria, J.M.; Briqueu, L.; Bosch, D.

    1998-01-01

    The Achkal Oligocene ring complex-cuts the Upper Eocene tholeiitic traps located on the top of the Hoggar swell. The plutonic rocks range from tholeiitic gabbros to alkali essexites, monzonites and syenites, whereas the volcanites are restricted to late per-alkaline rhyolites. The affinity change linked to the large isotopic heterogeneities (from EM1 to HIMU) suggests that the parental magmas are issued from two district mantle sources, first lithospheric then deeper. The Achkal has recorded the magmatic evolution of the Hoggar hot spot, between Eocene and Miocene. (authors)

  7. Monitoring environmental pollution of trace elements in tree-rings by synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF)

    International Nuclear Information System (INIS)

    Moreira, Silvana; Vives, Ana Elisa S. de; Brienza, Sandra Maria B.; Medeiros, Jean Gabriel S.; Tomazello Filho, Mario; Zucchi, Orgheda L.A.D.; Nascimento Filho, Virgilio F.

    2005-01-01

    This paper aims to study the environmental pollution in the tree development, as a manner to evaluate its use as bioindicator in urban and country sides. The sample collecting was carry out in Piracicaba city, Sao Paulo State, that presents high level of environmental contamination of the water, soil and air, due industrial activities, vehicles combustion, sugar-cane leaves burning in the harvesting, etc. It was selected the Caesalpinia peltophoroides ('Sibipiruna') specie because its very used in urban arborization. It was employed the analytical technique named total reflection X-ray fluorescence (TXRF) to identify and quantify the elements and metals of nutritional and toxicological importance in the wood samples. The analysis was done in the Brazilian Synchrotron Light Laboratory, using a white beam for excitation and a Si(Li) detector for characteristic X-ray detection. It was quantified the P, K, Ca, Ti, Fe, Sr, Ba e Pb elements. (author)

  8. Monitoring environmental pollution of trace elements in tree-rings by synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo]. E-mail: Silvana@fec.unicamp.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Brienza, Sandra Maria B. [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil) Faculdade de Ciencias Matematicas, da Natureza e de Tecnologia da Informacao]. E-mail: sbrienza@unimep.br; Medeiros, Jean Gabriel S.; Tomazello Filho, Mario [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]. E-mail: jeangm@esalq.usp.br; mtomazel@esalq.usp.br; Zucchi, Orgheda L.A.D. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear]. E-mail: virgilio@cena.usp.br

    2005-07-01

    This paper aims to study the environmental pollution in the tree development, as a manner to evaluate its use as bioindicator in urban and country sides. The sample collecting was carry out in Piracicaba city, Sao Paulo State, that presents high level of environmental contamination of the water, soil and air, due industrial activities, vehicles combustion, sugar-cane leaves burning in the harvesting, etc. It was selected the Caesalpinia peltophoroides ('Sibipiruna') specie because its very used in urban arborization. It was employed the analytical technique named total reflection X-ray fluorescence (TXRF) to identify and quantify the elements and metals of nutritional and toxicological importance in the wood samples. The analysis was done in the Brazilian Synchrotron Light Laboratory, using a white beam for excitation and a Si(Li) detector for characteristic X-ray detection. It was quantified the P, K, Ca, Ti, Fe, Sr, Ba e Pb elements. (author)

  9. Low-field spin dynamics of Cr7Ni and Cr7Ni-Cu -Cr 7Ni molecular rings as detected by μ SR

    Science.gov (United States)

    Sanna, S.; Arosio, P.; Bordonali, L.; Adelnia, F.; Mariani, M.; Garlatti, E.; Baines, C.; Amato, A.; Sabareesh, K. P. V.; Timco, G.; Winpenny, R. E. P.; Blundell, S. J.; Lascialfari, A.

    2017-11-01

    Muon spin rotation measurements were used to investigate the spin dynamics of heterometallic Cr7Ni and Cr7Ni -Cu-Cr7Ni molecular clusters. In Cr7Ni the magnetic ions are arranged in a quasiplanar ring and interact via an antiferromagnetic exchange coupling constant J , while Cr7Ni -Cu-Cr7Ni is composed of two Cr7Ni linked by a bridging moiety containing one Cu ion, that induces an inter-ring ferromagnetic interaction J'≪J . The longitudinal muon relaxation rate λ collected at low magnetic fields μ0H BPP)-like heuristic fitting model that takes into account of a distribution of electronic spin characteristic times for T >5 K, while the shoulder presented by Cr7Ni can be reproduced by a BPP function that incorporates a single electronic characteristic time theoretically predicted to dominate for T <5 K. The flattening of λ (T ) in Cr7Ni -Cu-Cr7Ni occurring at very low temperature can be tentatively attributed to field-dependent quantum effects and/or to an inelastic term in the spectral density of the electronic spin fluctuations.

  10. 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.

  11. Study of environmental contamination in growth tree rings of Copaifera Langsdorfii by SR-TXRF: evaluation of Cr, Ni, Cu, Zn and Pb

    International Nuclear Information System (INIS)

    Faria, Bruna Fernanda; Moreira, Silvana; Vives, Ana Elisa S. de

    2009-01-01

    Some arboreal species present annual cycles of growth and sleeping, registered in the log by different anatomical structures - the growth rings. With the objective of verifying the industrial activity in the city of Bauru, SP samples were submitted to a quantitative analysis in order to verify the bio-accumulation of metals. For that Synchrotron Radiation Total Reflection X-Ray Fluorescence was used. Samples of Copaifera Langsdorfii (Copaiba) were collected close to Municipal Forest of Bauru, SP located at 200m of distance of a disabled company of energy accumulators (batteries) known by receiving several penalties of CETESB due disagreement with the environmental legislation. Through the quantification of the elements Cr, Ni, Cu, Zn and Pb in the annual growth rings were possible to verify the influence of the battery industry in the local pollution. The temporal variation of Pb showed that after the interdiction of the battery industry the concentrations are close to the reference value, but in the periods previous to the industry interdiction the Pb concentrations were above the reference value. For Cr, 46% of the samples presented superior concentration to the reference value. Zinc presented larger concentration in the period from 1996 to 1998, reaching 1383 μg g -1 . For Cu the concentrations were higher than the reference value in almost all periods analyzed, that is, from 1969 to 2004. On the other hand Ni presented great oscillation in its concentration, and the highest values were observed in the period from 1969 to 1971 and from 1999 to 2001, reaching 87 μg g -1 . (author)

  12. Study of environmental contamination in growth tree rings of Copaifera Langsdorfii by SR-TXRF: evaluation of Cr, Ni, Cu, Zn and Pb

    Energy Technology Data Exchange (ETDEWEB)

    Faria, Bruna Fernanda; Moreira, Silvana, E-mail: bffaria@yahoo.com.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Dept. de Saneamento e Ambiente; Vives, Ana Elisa S. de, E-mail: aesvives@unimep.b [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo

    2009-07-01

    Some arboreal species present annual cycles of growth and sleeping, registered in the log by different anatomical structures - the growth rings. With the objective of verifying the industrial activity in the city of Bauru, SP samples were submitted to a quantitative analysis in order to verify the bio-accumulation of metals. For that Synchrotron Radiation Total Reflection X-Ray Fluorescence was used. Samples of Copaifera Langsdorfii (Copaiba) were collected close to Municipal Forest of Bauru, SP located at 200m of distance of a disabled company of energy accumulators (batteries) known by receiving several penalties of CETESB due disagreement with the environmental legislation. Through the quantification of the elements Cr, Ni, Cu, Zn and Pb in the annual growth rings were possible to verify the influence of the battery industry in the local pollution. The temporal variation of Pb showed that after the interdiction of the battery industry the concentrations are close to the reference value, but in the periods previous to the industry interdiction the Pb concentrations were above the reference value. For Cr, 46% of the samples presented superior concentration to the reference value. Zinc presented larger concentration in the period from 1996 to 1998, reaching 1383 mug g{sup -1}. For Cu the concentrations were higher than the reference value in almost all periods analyzed, that is, from 1969 to 2004. On the other hand Ni presented great oscillation in its concentration, and the highest values were observed in the period from 1969 to 1971 and from 1999 to 2001, reaching 87 mug g{sup -1}. (author)

  13. CHICSi - a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. I. General structure, mechanics and UHV compatibility

    International Nuclear Information System (INIS)

    Westerberg, L.; Avdeichikov, V.; Carlen, L.; Golubev, P.; Jakobsson, B.; Rouki, C.; Siwek, A.; Veldhuizen, E.J. van; Whitlow, H.J.

    2003-01-01

    CELSIUS Heavy-Ion Collision Silicon detector system (CHICSi) is a large solid angle, barrel-shaped detector system, housing up to 600 detector telescopes arranged in rotational symmetry around the beam axis. CHICSi measures charged particles and fragments from nuclear reactions. It operates at internal targets of storage rings. In order to optimize space and momentum-space coverage and minimize the low-energy detection limits, CHICSi is designed for use in ultra-high vacuum (UHV, ∼10 -8 Pa) inside a cluster-jet target chamber. This calls for materials in mechanical support, detectors, Very Large Scale Integrated (VLSI) electronics, connectors, cables and other signal transport devices with very low outgassing. Two auxiliary detector systems, which will operate in coincidence with CHICSi, a heavy-recoil, time-of-flight system (HR-TOF) also placed inside the target chamber and a projectile fragmentation wall (PF-WALL) located outside the chamber, have also been constructed. In total, this combined system registers more than 80% of all charged particles and fragments from typical heavy-ion reactions at energies of a few hundreds of MeV per nucleon

  14. CHICSi - a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. I. General structure, mechanics and UHV compatibility

    Energy Technology Data Exchange (ETDEWEB)

    Westerberg, L.; Avdeichikov, V.; Carlen, L.; Golubev, P.; Jakobsson, B. E-mail: bo.jakobsson@kosufy.lu.se; Rouki, C.; Siwek, A.; Veldhuizen, E.J. van; Whitlow, H.J

    2003-03-11

    CELSIUS Heavy-Ion Collision Silicon detector system (CHICSi) is a large solid angle, barrel-shaped detector system, housing up to 600 detector telescopes arranged in rotational symmetry around the beam axis. CHICSi measures charged particles and fragments from nuclear reactions. It operates at internal targets of storage rings. In order to optimize space and momentum-space coverage and minimize the low-energy detection limits, CHICSi is designed for use in ultra-high vacuum (UHV, {approx}10{sup -8} Pa) inside a cluster-jet target chamber. This calls for materials in mechanical support, detectors, Very Large Scale Integrated (VLSI) electronics, connectors, cables and other signal transport devices with very low outgassing. Two auxiliary detector systems, which will operate in coincidence with CHICSi, a heavy-recoil, time-of-flight system (HR-TOF) also placed inside the target chamber and a projectile fragmentation wall (PF-WALL) located outside the chamber, have also been constructed. In total, this combined system registers more than 80% of all charged particles and fragments from typical heavy-ion reactions at energies of a few hundreds of MeV per nucleon.

  15. Compact synchrotron radiation source

    International Nuclear Information System (INIS)

    Liu, N.; Wang, T.; Tian, J.; Lin, Y.; Chen, S.; He, W.; Hu, Y.; Li, Q.

    1985-01-01

    A compact 800 MeV synchrotron radiation source is discussed. The storage ring has a circumference of 30.3 m, two 90 degree and four 45 degree bending magnet sections, two long straight sections and four short straight sections. The radius of the bending magnet is 2.224m. The critical wave length is 24A. The injector is a 15 Mev Microtron Electrons are accelerated from 15 Mev to 800 Mev by ramping the field of the ring. The expected stored current will be around 100 ma

  16. CHICSi--a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. III. readout system

    Energy Technology Data Exchange (ETDEWEB)

    Carlen, L.; Foerre, G.; Golubev, P.; Jakobsson, B. E-mail: bo.jakobsson@kosufy.lu.se; Kolozhvari, A.; Marciniewski, P.; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J.; Oestby, J.M

    2004-01-11

    (CHICSi) Celsius Heavy Ion Collaboration Si detector system is a high granularity, modular detector telescope array for operation around the cluster-jet target/circulating beam intersection of the CELSIUS storage ring at the The. Svedberg Laboratory in Uppsala, Sweden. It is able to provide identity and momentum vector of up to 100 charged particles and fragments from proton-nucleus and nucleus-nucleus collisions at intermediate energies, 50-1000A MeV. All detector telescopes as well as the major part of electronic readout system are placed inside the target chamber in ultra-high vacuum (UHV, 10{sup -9}-10{sup -7} Pa). This requires Very Large Scale Integrated (VLSI) microchip for the spectroscopic signal processing and the generation and transport of digital control signals. Eighteen telescopes, read out with chip-on-board technique by ceramics Mother Boards (MB) and corresponding 18 microchips are mounted on a 450x45 mm{sup 2} Grand Mother Board (GMB), processed on FR4 glass-fibre material. Each of these 28 GMB units contains a daisy-chain organisation of the VLSI chips and associated protection circuits. Analogue-to-digital conversion of the spectroscopic signals is performed on a board outside the chamber which is connected on one side to a power distribution board, directly attached to a UHV mounting flange, and on the other side to the VME-based data acquisition system (CHICSiDAQ). This in its turn is connected via a fibre-optic link to the general TSL acquisition system (SVEDAQ), and in this way data from auxiliary detector systems, read out in CAMAC mode, can be stored in coincidence with CHICSi data.

  17. CHICSi--a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. III. readout system

    International Nuclear Information System (INIS)

    Carlen, L.; Foerre, G.; Golubev, P.; Jakobsson, B.; Kolozhvari, A.; Marciniewski, P.; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J.; Oestby, J.M.

    2004-01-01

    (CHICSi) Celsius Heavy Ion Collaboration Si detector system is a high granularity, modular detector telescope array for operation around the cluster-jet target/circulating beam intersection of the CELSIUS storage ring at the The. Svedberg Laboratory in Uppsala, Sweden. It is able to provide identity and momentum vector of up to 100 charged particles and fragments from proton-nucleus and nucleus-nucleus collisions at intermediate energies, 50-1000A MeV. All detector telescopes as well as the major part of electronic readout system are placed inside the target chamber in ultra-high vacuum (UHV, 10 -9 -10 -7 Pa). This requires Very Large Scale Integrated (VLSI) microchip for the spectroscopic signal processing and the generation and transport of digital control signals. Eighteen telescopes, read out with chip-on-board technique by ceramics Mother Boards (MB) and corresponding 18 microchips are mounted on a 450x45 mm 2 Grand Mother Board (GMB), processed on FR4 glass-fibre material. Each of these 28 GMB units contains a daisy-chain organisation of the VLSI chips and associated protection circuits. Analogue-to-digital conversion of the spectroscopic signals is performed on a board outside the chamber which is connected on one side to a power distribution board, directly attached to a UHV mounting flange, and on the other side to the VME-based data acquisition system (CHICSiDAQ). This in its turn is connected via a fibre-optic link to the general TSL acquisition system (SVEDAQ), and in this way data from auxiliary detector systems, read out in CAMAC mode, can be stored in coincidence with CHICSi data

  18. Studies of accelerated compact toruses

    International Nuclear Information System (INIS)

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

    1983-01-01

    In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, 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 (focusing) during acceleration. Because the allowable acceleration force, F/sub a/ = kappaU/sub m//R where (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

  19. 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)

  20. 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.

  1. The circular RFQ storage ring

    International Nuclear Information System (INIS)

    Ruggiero, A.G.

    1998-01-01

    This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features used in a conventional storage ring and an ion trap, and is basically a linear RFQ bend on itself. In summary the advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

  2. The Circular RFQ Storage Ring

    International Nuclear Information System (INIS)

    Ruggiero, A. G.

    1999-01-01

    This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features of conventional storage rings and ion traps, and is basically a linear RFQ bent on itself. The advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

  3. 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.

  4. Compact NMR

    Energy Technology Data Exchange (ETDEWEB)

    Bluemich, Bernhard; Haber-Pohlmeier, Sabina; Zia, Wasif [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie (ITMC)

    2014-06-01

    Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures, while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue. In both applications, the sample (or patient) is positioned inside a large, superconducting magnet to magnetize the atomic nuclei. Interrogating radio-frequency pulses result in frequency spectra that provide the chemist with molecular information, the medical doctor with anatomic images, and materials scientist with NMR relaxation parameters. Recent advances in magnet technology have led to a variety of small permanent magnets to allow compact and low-cost instruments. The goal of this book is to provide an introduction to the practical use of compact NMR at a level nearly as basic as the operation of a smart phone.

  5. Compact vortices

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D.; Losano, L.; Marques, M.A.; Zafalan, I. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil); Menezes, R. [Universidade Federal da Paraiba, Departamento de Ciencias Exatas, Rio Tinto, PB (Brazil); Universidade Federal de Campina Grande, Departamento de Fisica, Campina Grande, PB (Brazil)

    2017-02-15

    We study a family of Maxwell-Higgs models, described by the inclusion of a function of the scalar field that represent generalized magnetic permeability. We search for vortex configurations which obey first-order differential equations that solve the equations of motion. We first deal with the asymptotic behavior of the field configurations, and then implement a numerical study of the solutions, the energy density and the magnetic field. We work with the generalized permeability having distinct profiles, giving rise to new models, and we investigate how the vortices behave, compared with the solutions of the corresponding standard models. In particular, we show how to build compact vortices, that is, vortex solutions with the energy density and magnetic field vanishing outside a compact region of the plane. (orig.)

  6. Compact stars

    Science.gov (United States)

    Estevez-Delgado, Gabino; Estevez-Delgado, Joaquin

    2018-05-01

    An analysis and construction is presented for a stellar model characterized by two parameters (w, n) associated with the compactness ratio and anisotropy, respectively. The reliability range for the parameter w ≤ 1.97981225149 corresponds with a compactness ratio u ≤ 0.2644959374, the density and pressures are positive, regular and monotonic decrescent functions, the radial and tangential speed of sound are lower than the light speed, moreover, than the plausible stability. The behavior of the speeds of sound are determinate for the anisotropy parameter n, admitting a subinterval where the speeds are monotonic crescent functions and other where we have monotonic decrescent functions for the same speeds, both cases describing a compact object that is also potentially stable. In the bigger value for the observational mass M = 2.05 M⊙ and radii R = 12.957 Km for the star PSR J0348+0432, the model indicates that the maximum central density ρc = 1.283820319 × 1018 Kg/m3 corresponds to the maximum value of the anisotropy parameter and the radial and tangential speed of the sound are monotonic decrescent functions.

  7. 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

  8. Cosmic rings from colliding galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Mitton, S

    1976-11-18

    Research on two ring galaxies has led to the proposal of an interaction model to account for the rings. It is envisaged that this class of galaxy is created when a compact galaxy crashes through the disc of a spiral galaxy. The results of a spectroscopic investigation of the galaxy known as the Cartwheel and of another ring galaxy 11 NZ 4 are discussed. The general picture of ring galaxies which emerges from these studies of a massive starry nucleus with a necklace of emitting gas and some spokes and along the spin axis of the wheel a small companion galaxy that is devoid of interstellar gas. An explanation of these properties is considered.

  9. ring system

    African Journals Online (AJOL)

    1,3,2-DIAZABORACYCLOALKANE. RING SYSTEM. Negussie Retta" and Robert H. Neilson. 'Department of Chemistry, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. Department of Chemistry, Texas Christian University.

  10. 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

  11. 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.)

  12. Optimization of 90Sr/89Sr measurements

    Directory of Open Access Journals (Sweden)

    Legarda F.

    2012-04-01

    Full Text Available One of the key points in the double measurement method for the measurement of both, 89Sr and 90Sr, by using a proportional counter is the choice of the times at which the measurements should be done. In this paper, the formulae to calculate the 89Sr and 90Sr detection limits in conditions of radioactive equilibrium between 90Y and 90Sr are derived, and an analysis of them as a function of the time between the two measurements is done. The choice for the time of the second measurement is going to depend on the desired quality of the results to be obtained.

  13. Storage Rings

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Storage rings are circular machines that store particle beams at a constant energy. Beams are stored in rings without acceleration for a number of reasons (Tab. 1). Storage rings are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage rings such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage ring but may not be extracted (Fig. 1). Accelerator rings such as synchrotrons are used as storage rings before and after acceleration. Particles stored in rings include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10 -6 eV to 3.5 x 10 12 eV (LHC, 7 x 10 12 eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in rings requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage rings. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or positron beams

  14. 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

  15. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    ... through the compaction formulation process and application. Compaction of powder constituents both active ingredient and excipients is examined to ensure consistent and reproducible disintegration and dispersion profiles...

  16. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  17. Characterization of heterocyclic rings through quantum chemical topology.

    Science.gov (United States)

    Griffiths, Mark Z; Popelier, Paul L A

    2013-07-22

    Five-membered rings are found in a myriad of molecules important in a wide range of areas such as catalysis, nutrition, and drug and agrochemical design. Systematic insight into their largely unexplored chemical space benefits from first principle calculations presented here. This study comprehensively investigates a grand total of 764 different rings, all geometry optimized at the B3LYP/6-311+G(2d,p) level, from the perspective of Quantum Chemical Topology (QCT). For the first time, a 3D space of local topological properties was introduced, in order to characterize rings compactly. This space is called RCP space, after the so-called ring critical point. This space is analogous to BCP space, named after the bond critical point, which compactly and successfully characterizes a chemical bond. The relative positions of the rings in RCP space are determined by the nature of the ring scaffold, such as the heteroatoms within the ring or the number of π-bonds. The summed atomic QCT charges of the five ring atoms revealed five features (number and type of heteroatom, number of π-bonds, substituent and substitution site) that dictate a ring's net charge. Each feature independently contributes toward a ring's net charge. Each substituent has its own distinct and systematic effect on the ring's net charge, irrespective of the ring scaffold. Therefore, this work proves the possibility of designing a ring with specific properties by fine-tuning it through manipulation of these five features.

  18. Damping rings for CLIC

    CERN Document Server

    Jowett, John M; Zimmermann, Frank; Owen, H

    2001-01-01

    The Compact Linear Colider (CLIC) is designed to operate at 3 TeV centre-of-mass energy with a total luminosity of 10^35 cm^-2 s^-1. The overall system design leads to extremely demanding requirements on the bunch trains injected into the main libac at frequency of 100 Hz. In particular, the emittances of the intense bunches have to be about an order of magnitude smaller than presently achieved. We describe our approach to finding a damping ring design capable of meeting these requirements. Besides lattice design, emittance and damping rate considerations, a number of scattering and instability effects have to be incorporated into the optimisation of parameters. Among these, intra-bem scattering and the electron cloud effect are two of the most significant.

  19. 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

  20. Topography and diffractometry station in synchrotron radiation beam of the VEPP-4 storage ring. Topography of garnets

    International Nuclear Information System (INIS)

    Kub, I.; Poltsarova, M.; Panchenko, V.E.

    1987-01-01

    Advantages of synchrotron radiation (SR) spectrum of the VEhPP-4 storage ring for X-ray topography and diffractometry are shown. The description of ''Topography and diffractometry'' station in SR dump station of the VEhPP storage ring is presented, peculiarities of X-ray topography method used are discussed. X-ray topographic images of gadolinium-gallium and manganese-germanium garnets taken on the VEhPP SR are given in comparison with conventional images taken using X-ray tubes and SR of the VEhPP-3 storage ring

  1. Control system for compact SR light source 'AURORA'

    International Nuclear Information System (INIS)

    Fukami, Nobutaka; Kariya, Hiroyuki; Yamada, Hironari

    1991-01-01

    The computer control system developed for 'AURORA' has a three level hierarchical architecture. The top level is Central Intelligence System (CIS), and the second one is Autonomic Control System (ACS). The bottom one is an assembly of distributed local controllers linked to the ACS level through optical fibers. This system provides fully automated operation, and a powerful machine study capability through the associated man-machine console and an interpretive operation language. (author)

  2. Environmental 90Sr measurements

    Science.gov (United States)

    Paul, M.; Berkovits, D.; Cecil, L.D.; Feldstein, H.; Hershkowitz, A.; Kashiv, Y.; Vogt, S.

    1997-01-01

    90Sr (T1/2 = 28.5 years) is a long-lived radionuclide produced in nuclear fission. Fast radiochemical detection of 90Sr in environmental samples is not feasible using current analytical methods. Accelerator Mass Spectrometry (AMS) measurements of 90Sr were made with the Rehovot 14UD Pelletron accelerator at a terminal voltage of 11 or 12 MV using our standard detection system. Injection of hydride ions (SrH3-) was chosen owing to high beam intensity and low Coulomb explosion effects. 90Sr ions were identified and discriminated from isobaric 90Zr by measuring time of flight, total energy and three independent energy-loss signals in an ionization chamber. A reference sample and a ground-water sample were successfully measured. The detection limit determined for a laboratory blank by the residual counts in the 90Sr region is 90Sr/Sr = 3 ?? 10-13, corresponding in practice to (2-4) ?? 10790Sr atoms or about 0.5-1 pCi/L in environmental water samples.

  3. 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

  4. 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- ...

  5. Fundamentals of Coherent Synchrotron Radiation in Storage Rings

    International Nuclear Information System (INIS)

    Sannibale, F.; Byrd, J.M.; Loftsdottir, A.; Martin, M.C.; Venturini, M.

    2004-01-01

    We present the fundamental concepts for producing stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The analysis includes distortion of bunch shape from the synchrotron radiation (SR), enhancing higher frequency coherent emission and limits to stable emission due to a microbunching instability excited by the SR. We use these concepts to optimize the performance of a source for CSR emission

  6. ASSOCIATIVE RINGS SOLVED AS LIE RINGS

    Directory of Open Access Journals (Sweden)

    M. B. Smirnov

    2011-01-01

    Full Text Available The paper has proved that an associative ring which is solvable of a n- class as a Lie ring has a nilpotent ideal of the nilpotent class not more than 3×10n–2  and a corresponding quotient ring satisfies an identity [[x1, x2, [x3, x4

  7. Acceleration of a compact torus

    International Nuclear Information System (INIS)

    Hartmann, C.W.; Eddleman, J.L.; Hammer, J.H.; Kusse, B.

    1987-01-01

    The authors report the first results of a study of acceleration of spheromak-type compact toruses in the RACE experiment (plasma Ring ACceleration Experiment). The RACE apparatus consists of (1) a magnetized, coaxial plasma gun 50 cm long, 35 cm OD, 20 cm ID, (2) 600 cm long coaxial acceleration electrodes 50 cm OD, 20 cm ID, (3) a 250 kJ electrolytic capacitor bank to drive the gun solenoid for initial magnetization, (4) a 200 kJ gun bank, (5) a 260 kJ accelerator bank, and (6) magnetic probes and other diagnostics, and vacuum apparatus. To outer acceleration electrode is an extension, at larger OD, of the gun outer electrode, and the inner acceleration electrode is supported and fed by a coaxial insert in the gun center electrode as shown

  8. A Model Describing Stable Coherent Synchrotron Radiation in Storage Rings

    International Nuclear Information System (INIS)

    Sannibale, F.

    2004-01-01

    We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

  9. A model describing stable coherent synchrotron radiation in storage rings

    International Nuclear Information System (INIS)

    Sannibale, F.; Byrd, J.M.; Loftsdottir, A.; Venturini, M.; Abo-Bakr, M.; Feikes, J.; Holldack, K.; Kuske, P.; Wuestefeld, G.; Huebers, H.-W.; Warnock, R.

    2004-01-01

    We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission

  10. Ring resonator systems to perform optical communication enhancement using soliton

    CERN Document Server

    Amiri, Iraj Sadegh

    2014-01-01

    The title explain new technique of secured and high capacity optical communication signals generation by using the micro and nano ring resonators. The pulses are known as soliton pulses which are more secured due to having the properties of chaotic and dark soliton signals with ultra short bandwidth. They have high capacity due to the fact that ring resonators are able to generate pulses in the form of solitons in multiples and train form. These pulses generated by ring resonators are suitable in optical communication due to use the compact and integrated rings system, easy to control, flexibi

  11. An electron undulating ring for VLSI lithography

    International Nuclear Information System (INIS)

    Tomimasu, T.; Mikado, T.; Noguchi, T.; Sugiyama, S.; Yamazaki, T.

    1985-01-01

    The development of the ETL storage ring ''TERAS'' as an undulating ring has been continued to achieve a wide area exposure of synchrotron radiation (SR) in VLSI lithography. Stable vertical and horizontal undulating motions of stored beams are demonstrated around a horizontal design orbit of TERAS, using two small steering magnets of which one is used for vertical undulating and another for horizontal one. Each steering magnet is inserted into one of the periodic configulation of guide field elements. As one of useful applications of undulaing electron beams, a vertically wide exposure of SR has been demonstrated in the SR lithography. The maximum vertical deviation from the design orbit nCcurs near the steering magnet. The maximum vertical tilt angle of the undulating beam near the nodes is about + or - 2mrad for a steering magnetic field of 50 gauss. Another proposal is for hith-intensity, uniform and wide exposure of SR from a wiggler installed in TERAS, using vertical and horizontal undulating motions of stored beams. A 1.4 m long permanent magnet wiggler has been installed for this purpose in this April

  12. Self-Compacting Concrete

    OpenAIRE

    Okamura, Hajime; Ouchi, Masahiro

    2003-01-01

    Self-compacting concrete was first developed in 1988 to achieve durable concrete structures. Since then, various investigations have been carried out and this type of concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making self-compacting concrete a standard concrete.

  13. Compact Polarimetry Potentials

    Science.gov (United States)

    Truong-Loi, My-Linh; Dubois-Fernandez, Pascale; Pottier, Eric

    2011-01-01

    The goal of this study is to show the potential of a compact-pol SAR system for vegetation applications. Compact-pol concept has been suggested to minimize the system design while maximize the information and is declined as the ?/4, ?/2 and hybrid modes. In this paper, the applications such as biomass and vegetation height estimates are first presented, then, the equivalence between compact-pol data simulated from full-pol data and compact-pol data processed from raw data as such is shown. Finally, a calibration procedure using external targets is proposed.

  14. Pharmaceutical powder compaction technology

    National Research Council Canada - National Science Library

    Çelik, Metin

    2011-01-01

    "Revised to reflect modern pharmaceutical compacting techniques, this Second Edition guides pharmaceutical engineers, formulation scientists, and product development and quality assurance personnel...

  15. Compact Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  16. 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.

  17. 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

  18. Evaluating the use of strontium isotopes in tree rings to record the isotopic signal of dust deposited on the Wasatch Mountains

    International Nuclear Information System (INIS)

    Miller, Olivia L.; Solomon, Douglas Kip; Fernandez, Diego P.; Cerling, Thure E.; Bowling, David R.

    2014-01-01

    Highlights: • Dust was a major contributor of Sr to soil and tree rings over Sr poor bedrocks. • Tree rings were evaluated for their use as a record of dust strontium isotope history. • The isotopic signal of dust deposited on the Wasatch Mountains changed over the past ∼75 years. - Abstract: Dust cycling from the Great Basin to the Rocky Mountains is an important component of ecological and hydrological processes. We investigated the use of strontium (Sr) concentrations and isotope ratios ( 87 Sr/ 86 Sr) in tree rings as a proxy for dust deposition. We report Sr concentrations and isotope ratios ( 87 Sr/ 86 Sr) from atmospherically deposited dust, soil, bedrock, and tree rings from the Wasatch Mountains to investigate provenance of dust landing on the Wasatch Mountains and to determine if a dust Sr record is preserved in tree rings. Trees obtained a majority of their Sr from dust, making them a useful record of dust source and deposition. Dust contributions of Sr to soils were more than 94% over quartzite, 63% over granodiorite, and 50% over limestone. Dust contributions of Sr to trees were more than 85% in trees growing over quartzite, 55% over granodiorite, and between 0% and 92% over limestone. These findings demonstrate that a dust signal was preserved in some tree rings and reflects how Sr from dust and bedrock mixes within the soil. Trees growing over quartzite were most sensitive to dust. Changes in Sr isotope ratios for a tree growing over quartzite were interpreted as changes in dust source over time. This work has laid the foundation for using tree rings as a proxy for dust deposition over time

  19. Application of nanotechnology in self-compacting concrete design

    International Nuclear Information System (INIS)

    Maghsoudi, A. A.; Arabpour Dahooei, F.

    2009-01-01

    In this study, first, different mix design of four types of Self-Compacting Concrete, 1. Self-Compacting Concrete consisted of only nano silica, 2. Self-Compacting Concrete included only micro silica, 3. Self-Compacting Concrete consisted of both micro silica and nano silica and 4. Self-Compacting Concrete without micro silica and nano silica called as control mix, were casted and tested to find out the values of the Slump Flow, L-Box and 7 and 28 days compressive strength. Then, based on the results obtained and as yet there is no universally accepted standard for characterizing of Self-Compacting Concrete, the most suitable four concrete mixes were selected for further investigation of fresh and hardened concrete. For selected mixes, the fresh concrete properties such as values of the Slump Flow, L-Box, V-Funnel, J-Ring and hardened engineering properties such as compressive and flexural strength, shrinkage and swelling values were investigated for three curing conditions at short and long term. The results showed that the engineering properties of Self-Compacting Concrete mixes could not be improved by adding only nano silica. However, a satisfactory behavior can be achieved using micro silica in the Self-Compacting Concrete mixes. However, by adding both micro silica and nano silica to the Self-Compacting Concrete mixtures, the best effect on the engineering properties was reported while comparing to the control mixes.

  20. Uniaxial backfill block compaction

    International Nuclear Information System (INIS)

    Koskinen, V.

    2012-05-01

    The main parts of the project were: to make a literature survey of the previous uniaxial compaction experiments; do uniaxial compaction tests in laboratory scale; and do industrial scale production tests. Object of the project was to sort out the different factors affecting the quality assurance chain of the backfill block uniaxial production and solve a material sticking to mould problem which appeared during manufacturing the blocks of bentonite and cruched rock mixture. The effect of mineralogical and chemical composition on the long term functionality of the backfill was excluded from the project. However, the used smectite-rich clays have been tested for mineralogical consistency. These tests were done in B and Tech OY according their SOPs. The objective of the Laboratory scale tests was to find right material- and compaction parameters for the industrial scale tests. Direct comparison between the laboratory scale tests and industrial scale tests is not possible because the mould geometry and compaction speed has a big influence for the compaction process. For this reason the selected material parameters were also affected by the previous compaction experiments. The industrial scale tests were done in summer of 2010 in southern Sweden. Blocks were done with uniaxial compaction. A 40 tons of the mixture of bentonite and crushed rock blocks and almost 50 tons of Friedland-clay blocks were compacted. (orig.)

  1. Compaction properties of isomalt

    NARCIS (Netherlands)

    Bolhuis, Gerad K.; Engelhart, Jeffrey J. P.; Eissens, Anko C.

    Although other polyols have been described extensively as filler-binders in direct compaction of tablets, the polyol isomalt is rather unknown as pharmaceutical excipient, in spite of its description in all the main pharmacopoeias. In this paper the compaction properties of different types of

  2. Model Compaction Equation

    African Journals Online (AJOL)

    The currently proposed model compaction equation was derived from data sourced from the. Niger Delta and it relates porosity to depth for sandstones under hydrostatic pressure condition. The equation is useful in predicting porosity and compaction trend in hydrostatic sands of the. Niger Delta. GEOLOGICAL SETTING OF ...

  3. Stabilization of compactible waste

    International Nuclear Information System (INIS)

    Franz, E.M.; Heiser, J.H. III; Colombo, P.

    1990-09-01

    This report summarizes the results of series of experiments performed to determine the feasibility of stabilizing compacted or compactible waste with polymers. The need for this work arose from problems encountered at disposal sites attributed to the instability of this waste in disposal. These studies are part of an experimental program conducted at Brookhaven National Laboratory (BNL) investigating methods for the improved solidification/stabilization of DOE low-level wastes. The approach taken in this study was to perform a series of survey type experiments using various polymerization systems to find the most economical and practical method for further in-depth studies. Compactible dry bulk waste was stabilized with two different monomer systems: styrene-trimethylolpropane trimethacrylate (TMPTMA) and polyester-styrene, in laboratory-scale experiments. Stabilization was accomplished by wetting or soaking compactible waste (before or after compaction) with monomers, which were subsequently polymerized. Three stabilization methods are described. One involves the in-situ treatment of compacted waste with monomers in which a vacuum technique is used to introduce the binder into the waste. The second method involves the alternate placement and compaction of waste and binder into a disposal container. In the third method, the waste is treated before compaction by wetting the waste with the binder using a spraying technique. A series of samples stabilized at various binder-to-waste ratios were evaluated through water immersion and compression testing. Full-scale studies were conducted by stabilizing two 55-gallon drums of real compacted waste. The results of this preliminary study indicate that the integrity of compacted waste forms can be readily improved to ensure their long-term durability in disposal environments. 9 refs., 10 figs., 2 tabs

  4. Simplified compact containment BWR plant

    International Nuclear Information System (INIS)

    Heki, H.; Nakamaru, M.; Tsutagawa, M.; Hiraiwa, K.; Arai, K.; Hida, T.

    2004-01-01

    The reactor concept considered in this paper has a small power output, a compact containment and a simplified BWR configuration with comprehensive safety features. The Compact Containment Boiling Water Reactor (CCR), which is being developed with matured BWR technologies together with innovative systems/components, is expected to prove attractive in the world energy markets due to its flexibility in regard to both energy demands and site conditions, its high potential for reducing investment risk and its safety features facilitating public acceptance. The flexibility is achieved by CCR's small power output of 300 MWe class and capability of long operating cycle (refueling intervals). CCR is expected to be attractive from view point of investment due to its simplification/innovation in design such as natural circulation core cooling with the bottom located short core, internal upper entry control rod drives (CRDs) with ring-type dryers and simplified ECCS system with high pressure containment concept. The natural circulation core eliminates recirculation pumps and the maintenance of such pumps. The internal upper entry CRDs reduce the height of the reactor vessel (RPV) and consequently reduce the height of the primary containment vessel (PCV). The safety features mainly consist of large water inventory above the core without large penetration below the top of the core, passive cooling system by isolation condenser (IC), passive auto catalytic recombiner and in-vessel retention (IVR) capability. The large inventory increases the system response time in the case of design-base accidents, including loss of coolant accidents. The IC suppresses PCV pressure by steam condensation without any AC power. The recombiner decreases hydrogen concentration in the PCV in the case of a severe accident. Cooling the molten core inside the RPV if the core should be damaged by loss of core coolability could attain the IVR. The feasibility of CCR safety system has been confirmed by LOCA

  5. Mouse Embryo Compaction.

    Science.gov (United States)

    White, M D; Bissiere, S; Alvarez, Y D; Plachta, N

    2016-01-01

    Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo. © 2016 Elsevier Inc. All rights reserved.

  6. Electron Storage Ring Development for ICS Sources

    Energy Technology Data Exchange (ETDEWEB)

    Loewen, Roderick [Lyncean Technologies, Inc., Palo Alto, CA (United States)

    2015-09-30

    There is an increasing world-wide interest in compact light sources based on Inverse Compton Scattering. Development of these types of light sources includes leveraging the investment in accelerator technology first developed at DOE National Laboratories. Although these types of light sources cannot replace the larger user-supported synchrotron facilities, they offer attractive alternatives for many x-ray science applications. Fundamental research at the SLAC National Laboratory in the 1990’s led to the idea of using laser-electron storage rings as a mechanism to generate x-rays with many properties of the larger synchrotron light facilities. This research led to a commercial spin-off of this technology. The SBIR project goal is to understand and improve the performance of the electron storage ring system of the commercially available Compact Light Source. The knowledge gained from studying a low-energy electron storage ring may also benefit other Inverse Compton Scattering (ICS) source development. Better electron storage ring performance is one of the key technologies necessary to extend the utility and breadth of applications of the CLS or related ICS sources. This grant includes a subcontract with SLAC for technical personnel and resources for modeling, feedback development, and related accelerator physics studies.

  7. Orbital dynamics in a storage ring with electrostatic bending

    International Nuclear Information System (INIS)

    Mane, S.R.

    2008-01-01

    A storage ring where electrostatic fields contribute to the bending and focusing of the orbital motion has some novel features because, unlike a magnetostatic field, an electrostatic field can change the kinetic energy of the particles. I present analytical formulas to calculate the linear focusing gradient, dispersion, momentum compaction and natural chromaticity for a storage ring with a radial electrostatic field. I solve the formulas explicitly for a weak focusing model.

  8. Small Valdivia compact spaces

    CERN Document Server

    Kubi's, W; Kubi\\'s, Wieslaw; Michalewski, Henryk

    2005-01-01

    We prove a preservation theorem for the class of Valdivia compact spaces, which involves inverse sequences of ``simple'' retractions. Consequently, a compact space of weight $\\loe\\aleph_1$ is Valdivia compact iff it is the limit of an inverse sequence of metric compacta whose bonding maps are retractions. As a corollary, we show that the class of Valdivia compacta of weight at most $\\aleph_1$ is preserved both under retractions and under open 0-dimensional images. Finally, we characterize the class of all Valdivia compacta in the language of category theory, which implies that this class is preserved under all continuous weight preserving functors.

  9. Compact turbidity meter

    Science.gov (United States)

    Hirschberg, J. G.

    1979-01-01

    Proposed monitor that detects back-reflected infrared radiation makes in situ turbidity measurements of lakes, streams, and other bodies of water. Monitor is compact, works well in daylight as at night, and is easily operated in rough seas.

  10. 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.

  11. 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 ...

  12. 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

  13. The present status of a compact synchrotron radiation source LUNA of IHI

    International Nuclear Information System (INIS)

    Marushita, Motoharu; Oishi, Masaya; Takahashi, Mitsuyuki; Komatsu, Takahito; Mandai, Shinichi

    1993-01-01

    Synchrotron radiation is expected to apply to many fields of science and industry and we are specially interested in availability of SR for X-ray lithography. This paper presents the characteristics, the design parameters, the features and current status of LUNA. Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI) has developed a compact synchrotron radiation source 'LUNA' for lithography and has successfully stored beam current at full energy. LUNA consists of a 45 MeV linear accelerator as an electron injector and an 800 MeV synchrotron as a storage ring. The construction of LUNA has been completed in April 1989 at IHI Tsuchiura facility near Tsukuba. Synchrotron Radiation was first observed at December 1989. The design goal, which is to store beam current of 50 mA with the beam lifetime of over 30 minutes, has been successfully achieved in March 1991. At present the stored beam current is 80 mA with the beam lifetime of over 5 hours. (author)

  14. Synthesis, structure and fluorescence properties of a novel 3D Sr(II) coordination polymer

    Science.gov (United States)

    Tan, Yu-Hui; Xu, Qing; Gu, Zhi-Feng; Gao, Ji-Xing; Wang, Bin; Liu, Yi; Yang, Chang-Shan; Tang, Yun-Zhi

    2016-09-01

    Solvothermal reaction of 2,2‧-bipyridine-5,5‧-dicarboxylic acid (H2bpdc) and SrCl2 affords a novel coordination polymer [Sr(Hbpdc)2]n1. X-ray structure determination shows that 1 exhibits a novel three-dimensional network. The unique Sr II cation sits on a two-fold axis and coordinated by four O-atom donors from four Hbptc- ligands and four N-atom donors from two Hbptc- ligands in distorted dodecahedral geometry. In 1 each Sr II cation connects to six different Hbptc- ligands and each Hbptc- ligand bridges three different Sr II cations which results in the formation of a three-dimensional polymeric structure. Corresponding to the free ligand, the fluorescent emission of complex 1 display remarkable "Einstain" shifts, which may be attributed to the coordination interaction of Sr atoms, thus reduce the rigidity of pyridyl rings.

  15. Stability of large orbit, high-current particle rings

    International Nuclear Information System (INIS)

    Lovelace, R.V.E.

    1994-01-01

    A review is made of theory of the low-frequency stability of large orbit, high-current particle rings which continue to be of interest for compact fusion systems. The precession mode was the first mode predicted by Furth and observed by Christofilos to be unstable under certain conditions. Subsequently, many detailed studies have been made of the stability of particle rings- different modes, different ring geometries, systems with/without a toroidal B field, and sytems with/without a current carrying plasma component. The possibly dangerous modes are still thought to include the precession mode, the tilting mode, and the low order kink modes. copyright American Institute of Physics

  16. Surface emitting ring quantum cascade lasers for chemical sensing

    Science.gov (United States)

    Szedlak, Rolf; Hayden, Jakob; Martín-Mateos, Pedro; Holzbauer, Martin; Harrer, Andreas; Schwarz, Benedikt; Hinkov, Borislav; MacFarland, Donald; Zederbauer, Tobias; Detz, Hermann; Andrews, Aaron Maxwell; Schrenk, Werner; Acedo, Pablo; Lendl, Bernhard; Strasser, Gottfried

    2018-01-01

    We review recent advances in chemical sensing applications based on surface emitting ring quantum cascade lasers (QCLs). Such lasers can be implemented in monolithically integrated on-chip laser/detector devices forming compact gas sensors, which are based on direct absorption spectroscopy according to the Beer-Lambert law. Furthermore, we present experimental results on radio frequency modulation up to 150 MHz of surface emitting ring QCLs. This technique provides detailed insight into the modulation characteristics of such lasers. The gained knowledge facilitates the utilization of ring QCLs in combination with spectroscopic techniques, such as heterodyne phase-sensitive dispersion spectroscopy for gas detection and analysis.

  17. Compact type mutants in apple and sour cherries

    International Nuclear Information System (INIS)

    Zagaja, S.W.; Przybyla, A.

    1976-01-01

    Induction of mutations in deciduous fruits is considered complementary to the conventional breeding methods. Several promissing mutants, particularly in apples, were described and some of them were introduced to commercial orchards. Studies described herein are aimed at developing compact type mutants in apple cultivars, apple rootstocks and in sour cherry cultivars. Data obtained so far confirm the results of the other authors, who developed compact type mutants in apples and sweet cherries. Physiological studies have shown that the leaves of spontaneous apple mutants of compact type are more efficient in photosynthesis than the leaves of respective standards. In spite of this, using branch ringing techniques, it was found that the leaves of compacts and those of standards do not differ in their productivity. There seem to be several advantages in employing tissue culture technique in mutation breeding. That is why a project was started to work out a method of growing apple shoots from adventitious buds developed on sections of roots. (author)

  18. Compaction of FGD-gypsum

    NARCIS (Netherlands)

    Stoop, B.T.J.; Larbi, J.A.; Heijnen, W.M.M.

    1996-01-01

    It is shown that it is possible to produce compacted gypsum with a low porosity and a high strength on a laboratory scale by uniaxial compaction of flue gas desulphurization (FGD-) gypsum powder. Compacted FGD-gypsum cylinders were produced at a compaction pres-sure between 50 and 500 MPa yielding

  19. Projects of SR sources including research and development for insertion devices in the USSR

    International Nuclear Information System (INIS)

    Kulipanov, G.

    1990-01-01

    Some technical information on the electron and positron storage rings - SR sources that are being constructed, used or developed at the Novosibirsk Institute of Nuclear Physics (INP), is given. The parameters and construction of wigglers and undulators (electromagnetic, superconducting, and based on permanent magnets) that are intended to be used at such storage rings are described. Various schemes of installation of wigglers, undulators and FEL at storage rings is considered. The ways of minimizing the influence of their magnetic fields on particle motion in storage rings are treated. (author)

  20. Physically detached 'compact groups'

    Science.gov (United States)

    Hernquist, Lars; Katz, Neal; Weinberg, David H.

    1995-01-01

    A small fraction of galaxies appear to reside in dense compact groups, whose inferred crossing times are much shorter than a Hubble time. These short crossing times have led to considerable disagreement among researchers attempting to deduce the dynamical state of these systems. In this paper, we suggest that many of the observed groups are not physically bound but are chance projections of galaxies well separated along the line of sight. Unlike earlier similar proposals, ours does not require that the galaxies in the compact group be members of a more diffuse, but physically bound entity. The probability of physically separated galaxies projecting into an apparent compact group is nonnegligible if most galaxies are distributed in thin filaments. We illustrate this general point with a specific example: a simulation of a cold dark matter universe, in which hydrodynamic effects are included to identify galaxies. The simulated galaxy distribution is filamentary and end-on views of these filaments produce apparent galaxy associations that have sizes and velocity dispersions similar to those of observed compact groups. The frequency of such projections is sufficient, in principle, to explain the observed space density of groups in the Hickson catalog. We discuss the implications of our proposal for the formation and evolution of groups and elliptical galaxies. The proposal can be tested by using redshift-independent distance estimators to measure the line-of-sight spatial extent of nearby compact groups.

  1. Conceptual design of a moving-ring reactor

    International Nuclear Information System (INIS)

    Smith, A.C.; Carlson, G.A.; Ashworth, C.P.

    1986-01-01

    A design of a prototype moving-ring reactor was completed, and a development plan for a pilot reactor is outlined. 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 one-third of the total burn time at each station. Deuterium-tritium- 3 He ice pellets refuel the rings at a rate that maintains constant radiated power. The fusion power per ring is approx. =105.5 MW. The burn time to reach a fusion energy gain of Q = 30 is 5.9 s

  2. The vibration measurements at the photon factory storage ring building

    International Nuclear Information System (INIS)

    Haga, K.; Nakayama, M.; Masuda, K.; Ishizaki, H.; Kura, M.; Meng, L.; Oku, Y.

    1999-01-01

    The Photon Factory is a 2.5 GeV electron storage ring and has been operating since 1982 as a dedicated SR source. At the Photon Factory, we have been pursuing the various sources of the beam instabilities which deteriorated the SR beam quality in the wide frequency range. Some of the sources were the vibrations of magnets and floor of the ring tunnel, temperature change of the cooling water and the elongation of the storage ring building roof due to sunshine that induced the diurnal motion of the SR beam axis. This article presents the results of the vibration measurements that have been performed at the Photon Factory storage ring building. (1) The vibrations of the ring tunnel floor and the experimental hall floor, comparing with the vibration of the ground surrounding the storage ring building, are same order in the 1 ∼ 5 Hz range, and 1/3 ∼ 1/5 in the 5 ∼ 100 Hz range, in the vertical and the horizontal direction. (2) The effects of the vibration arising from the operating eight air-conditioners can be seen in the Fourier spectrum of the vibration of the ring tunnel floor, experimental floor, Q-magnets and BPM vacuum duct. (3) The vibrations of the Q-magnet and girder at frequencies near their fundamental resonant frequencies have been amplified 100 limes in the lateral direction comparing to the floor vibration. (4) Correlation between the vibration of the BPM vacuum duct and the vibration of the electron beam motion is unknown for the lack of the precise data. (authors)

  3. Inhomogeneous compact extra dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Bronnikov, K.A. [Center of Gravity and Fundamental Metrology, VNIIMS, 46 Ozyornaya st., Moscow 119361 (Russian Federation); Budaev, R.I.; Grobov, A.V.; Dmitriev, A.E.; Rubin, Sergey G., E-mail: kb20@yandex.ru, E-mail: buday48@mail.ru, E-mail: alexey.grobov@gmail.com, E-mail: alexdintras@mail.ru, E-mail: sergeirubin@list.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), 115409 Moscow (Russian Federation)

    2017-10-01

    We show that an inhomogeneous compact extra space possesses two necessary features— their existence does not contradict the observable value of the cosmological constant Λ{sub 4} in pure f ( R ) theory, and the extra dimensions are stable relative to the 'radion mode' of perturbations, the only mode considered. For a two-dimensional extra space, both analytical and numerical solutions for the metric are found, able to provide a zero or arbitrarily small Λ{sub 4}. A no-go theorem has also been proved, that maximally symmetric compact extra spaces are inconsistent with 4D Minkowski space in the framework of pure f ( R ) gravity.

  4. Interim initial state report for the safety assessment SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Pers, Karin (ed.) [Kemakta Konsult AB, Stockholm (Sweden)

    2004-07-01

    the cylindrical canister has a length of approximately 4.8 metres and a diameter of 1.05 metres. The copper shell is made of pure oxygen-free copper. The insert is cast from spheroidal graphite cast iron and has channels where the fuel assemblies are placed. The insert is presently available in two versions: one for 12 BWR assemblies and one for 4 PWR assemblies. A canister holds about two tonnes of spent fuel. Canisters with BWR and PWR assemblies weigh 25 and 27 tonnes, respectively. The decay heat in the spent fuel deposited in one canister is limited to 1700 W, to fulfil temperature requirements at the canister surface in the deposition hole. A total of about 4500 canisters will be produced according to current estimates. In the deposition holes, the copper canister is surrounded by a buffer of clay. The buffer is deposited as bentonite blocks and rings. The final decision on excavation technique for the deposition tunnels has not been taken and two possible techniques, drill and blast or mechanical excavation (tunnel boring machine), are analysed in SR-Can. The excavation technique will have implications on the dimensions and shape of the deposition tunnels. The cross section in a drill and blast deposition tunnel is a square with an arched roof, whereas the cross section in a mechanically excavated tunnel is circular. Two different backfill concepts are analysed. One is an in situ compacted mixture of crushed rock and bentonite of the same type as in the buffer and the other comprises pre-compacted blocks of Friedland clay. A number of more or less vertical investigation or surface-based characterisation boreholes are to be drilled during site investigations in order to obtain, e.g. data on the properties of the rock. These boreholes will be sealed, no later than at the closure of the deep repository. Some holes will be bored from the repository tunnels during the construction phase, meaning that horizontal and upwards-directed holes also have to be sealed. The

  5. Interim initial state report for the safety assessment SR-Can

    International Nuclear Information System (INIS)

    Pers, Karin

    2004-07-01

    the cylindrical canister has a length of approximately 4.8 metres and a diameter of 1.05 metres. The copper shell is made of pure oxygen-free copper. The insert is cast from spheroidal graphite cast iron and has channels where the fuel assemblies are placed. The insert is presently available in two versions: one for 12 BWR assemblies and one for 4 PWR assemblies. A canister holds about two tonnes of spent fuel. Canisters with BWR and PWR assemblies weigh 25 and 27 tonnes, respectively. The decay heat in the spent fuel deposited in one canister is limited to 1700 W, to fulfil temperature requirements at the canister surface in the deposition hole. A total of about 4500 canisters will be produced according to current estimates. In the deposition holes, the copper canister is surrounded by a buffer of clay. The buffer is deposited as bentonite blocks and rings. The final decision on excavation technique for the deposition tunnels has not been taken and two possible techniques, drill and blast or mechanical excavation (tunnel boring machine), are analysed in SR-Can. The excavation technique will have implications on the dimensions and shape of the deposition tunnels. The cross section in a drill and blast deposition tunnel is a square with an arched roof, whereas the cross section in a mechanically excavated tunnel is circular. Two different backfill concepts are analysed. One is an in situ compacted mixture of crushed rock and bentonite of the same type as in the buffer and the other comprises pre-compacted blocks of Friedland clay. A number of more or less vertical investigation or surface-based characterisation boreholes are to be drilled during site investigations in order to obtain, e.g. data on the properties of the rock. These boreholes will be sealed, no later than at the closure of the deep repository. Some holes will be bored from the repository tunnels during the construction phase, meaning that horizontal and upwards-directed holes also have to be sealed. The

  6. Formation and acceleration of precompressed compact tori in RACE

    International Nuclear Information System (INIS)

    Molvik, A.W.; Eddleman, J.L.; Hammer, J.H.; Hartman, C.W.; McLean, H.S.

    1990-01-01

    Many applications of the compact torus accelerator, CTA, concept (such as a driver for inertial fusion, or magnetically insulated inertial fusion) require maximizing the power density by compressing the compact torus, CT. The ring accelerator experiment, RACE, has compressed CT's by a factor of 2 in radius before acceleration, after being reconfigured with a precompressor cone followed by a short, 80 cm long, coaxial accelerator. The authors show the gas valves and gun, precompressor, and the beginning of the accelerator. The inner acceleration electrode begins at the precompressor cone after passing through the inner gun electrode. The authors discuss the experimental results of slow formation, compression, and acceleration in this new geometry

  7. 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

  8. 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.

  9. 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

  10. Review of SR 97

    International Nuclear Information System (INIS)

    Voss, C.I.

    2000-01-01

    The safety analysis conducted by SKB for SR 97 is impressive in terms of both scale and content. In addition to an eventual solution to Sweden's nuclear waste isolation question, much general scientific knowledge of real value in other applications will be created as a by-product of SKB's efforts. This review focuses on those geoscience aspects of SR 97 that have the most important effects on radionuclide release from each barrier. Indeed, SR 97 elucidates the most important geoscience parameters that control releases from the near field and the far field; these comprise mainly the transport resistance parameter, and the sorption coefficients for each nuclide, the matrix diffusion coefficient, and the Darcy flux. The Main Report is the most important document in SR 97 inasmuch as it is the only one that brings together all of the supporting work to answer the question of safety. Unfortunately pervading the good supporting work done is the impression that the Main Report is not balanced, that it emphasizes optimistic aspects and downplays the negative. SKB specifies 3 main requirements to guarantee proper repository function: a non-oxidizing subsurface environment, temperatures less than 100 C, and a mechanically stable low-permeability buffer surrounding the canisters. The first and third requirements are not thoroughly proven by SKB. One source of near-field doubt stems from the consequences of combinations of scenarios in which several negative events are linked, while the effect of each scenario is mainly evaluated only independently in SR 97. More pertinently, disastrous breakdown of complex systems may occur due to a chain of linked failures. For example, in the glacial scenario: high ground-water flow (possible ablation of buffer and high fluid transport), change in ground-water chemistry (even the possibility of oxidizing conditions), new flow paths, significant changes in mechanical stress and possible motion along faults (which may also generate new flow

  11. Characterization of ceramic powder compacts

    International Nuclear Information System (INIS)

    Yanai, K.; Ishimoto, S.; Kubo, T.; Ito, K.; Ishikawa, T.; Hayashi, H.

    1995-01-01

    UO 2 and Al 2 O 3 powder packing structures in cylindrical powder compacts are observed by scanning electron microscopy using polished cross sections of compacts fixed by low viscosity epoxy resin. Hard aggregates which are not destroyed during powder compaction are observed in some of the UO 2 powder compacts. A technique to measure local density in powder compacts is developed based on counting characteristic X-ray intensity by energy dispersive X-ray analysis (EDX). The local density of the corner portion of the powder compact fabricated by double-acting dry press is higher than that of the inner portion. ((orig.))

  12. Stable CSR in storage rings: A model

    International Nuclear Information System (INIS)

    Sannibale, Fernando; Byrd, John M.; Loftsdottir, Agusta; Venturini, Marco; Abo-Bakr, Michael; Feikes, Jorge; Holldack, Karsten; Kuske, Peter; Wustefeld, Godehart; Hubers, Heinz-Willerm; Warnock, Robert

    2005-01-01

    A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user s shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

  13. Stable CSR in Storage Rings: A Model

    International Nuclear Information System (INIS)

    Sannibale, F.

    2005-01-01

    A comprehensive historical view of the work done on coherent synchrotron radiation (CSR) in storage rings is given in reference [1]. Here we want just to point out that even if the issue of CSR in storage rings was already discussed over 50 years ago, it is only recently that a considerable number of observations have been reported. In fact, intense bursts of coherent synchrotron radiation with a stochastic character were measured in the terahertz frequency range, at several synchrotron light source storage rings [2-8]. It has been shown [8-11], that this bursting emission of CSR is associated with a single bunch instability, usually referred as microbunching instability (MBI), driven by the fields of the synchrotron radiation emitted by the bunch itself. Of remarkably different characteristics was the CSR emission observed at BESSY II in Berlin, when the storage ring was tuned into a special low momentum compaction mode [12, 13]. In fact, the emitted radiation was not the quasi-random bursting observed in the other machines, but a powerful and stable flux of broadband CSR in the terahertz range. This was an important result, because it experimentally demonstrated the concrete possibility of constructing a stable broadband source with extremely high power in the terahertz region. Since the publication of the first successful experiment using the ring as a CSR source [14], BESSY II has regular scheduled user's shifts dedicated to CSR experiments. At the present time, several other laboratories are investigating the possibility of a CSR mode of operation [15-17] and a design for a new ring optimized for CSR is at an advanced stage [18]. In what follows, we describe a model that first accounts for the BESSY II observations and then indicates that the special case of BESSY II is actually quite general and typical when relativistic electron storage rings are tuned for short bunches. The model provides a scheme for predicting and optimizing the performance of ring

  14. 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.

  15. Preparation of highly stable zeolite-alginate foam composite for strontium(90Sr) removal from seawater and evaluation of Sr adsorption performance.

    Science.gov (United States)

    Hong, Hye-Jin; Kim, Byoung-Gyu; Ryu, Jungho; Park, In-Su; Chung, Kang-Sup; Lee, Sang Moon; Lee, Jin-Bae; Jeong, Hyeon Su; Kim, Hyunchul; Ryu, Taegong

    2018-01-01

    Alginate bead is a promising strontium (Sr) adsorbent in seawater, but highly concentrated Na ions caused over-swelling and damaged the hydrogel bead. To improve the mechanical stability of alginate bead, flexible foam-type zeolite-alginate composite was synthesized and Sr adsorption performance was evaluated in seawater; 1-10% zeolite immobilized alginate foams were prepared by freeze-dry technique. Immobilization of zeolite into alginate foam converted macro-pores to meso-pores which lead to more compact structure. It resulted in less swollen composite in seawater medium and exhibited highly improved mechanical stability compared with alginate bead. Besides, Sr adsorption efficiency and selectivity were enhanced by immobilization of zeolite in alginate foam due to the increase of Sr binding sites (zeolite). In particular, Sr selectivity against Na was highly improved. The 10% zeolite-alginate foam exhibited a higher log K d of 3.3, while the pure alginate foam exhibited 2.7 in the presence of 0.1 M Na. Finally, in the real seawater, the 10% zeolite-alginate foam exhibited 1.5 times higher Sr adsorption efficiency than the pure alginate foam. This result reveals that zeolite-alginate foam composite is appropriate material for Sr removal in seawater due to its swelling resistance as well as improved Sr adsorption performance in complex media. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Correlations and fixation of some elements in tree rings

    International Nuclear Information System (INIS)

    Goldberg, E.L.; Zolotarev, K.B.; Maksimovskaya, V.V.; Kondratyev, V.I.; Ovchinnikov, D.V.; Naurzbaev, M.M.

    2007-01-01

    High-resolution scanning with Synchrotron Radiation X-ray Fluorescence Analysis (SRXFA) was applied to investigate element distributions in tree rings. Two cores of Siberia Larch have been investigated with resolution 100-200 mkm. Two groups of elements in tree rings with different trends have been found. The members of the first group are Br, Zn, Cl, whose trends correlate with each other. Moreover, trends of Br, Zn, Cl in tree rings are similar to the trend of atmosphere precipitation in the region investigated. Other group of elements are represented by K, Ca, Sr, Mn, Fe, but their trends differ sufficiently from trend of elements of the first group. Extended fixation of elements in tree rings is observed for elements of the first group over the whole interval investigated (150 years). In contrast, elements of the second group mainly accumulate in external part of tree stem

  17. Proceedings of the third symposium on the physics and technology of compact toroids in the magnetic fusion energy program

    International Nuclear Information System (INIS)

    Siemon, R.E.

    1981-03-01

    This document contains papers contributed by the participants of the Third Symposium on Physics and Technology of Compact Toroids in the Magnetic Fusion Energy Program. Subjects include reactor aspects of compact toroids, energetic particle rings, spheromak configurations (a mixture of toroidal and poloidal fields), and field-reversed configurations

  18. Decay of 83Sr

    International Nuclear Information System (INIS)

    Yu Xiaohan; Shi Shuanghui; Gu Jiahui

    1997-01-01

    The decay of 83 Sr was reinvestigated using γ singles and γ-γ-t coincidence measurement. A new level scheme of Rb, which contains 41 excited levels and about 180 transitions, is constructed. 19 new levels were added to the old level scheme and 8 formerly adopted levels were denied. A new data set of branching ratio, log(ft) value and spin parity was obtained

  19. Weakly compact operators and interpolation

    OpenAIRE

    Maligranda, Lech

    1992-01-01

    The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. In this survey, we have collected and ordered some of this (partly very new) knowledge. We have also included some comments, remarks and examples. The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. I...

  20. 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

  1. Diffusion and sorption properties of radionuclides in compacted bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Yu Ji-Wei; Neretnieks, I. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    1997-07-01

    In this report, recent studies on sorption and diffusion of radionuclides in compacted bentonite have been reviewed. The sorption distribution coefficient and diffusion coefficient data obtained from experiments in the literature have been compiled. Based on these experimental data and the report SKB-TR--91-16 (Brandberg and Skagius, 1991), this report proposes a set of sorption distribution coefficient and diffusion coefficient values for modelling purpose for safety analysis of nuclear waste repositories. The variability and uncertainty of the diffusivity data span somewhat more than an order or magnitude up and down. Most of the nuclides have an effective diffusivity in around 10{sup -10} m{sup 2}/s. Ion exclusion effects are observed for C, Cl and for Tc in oxidizing waters. Effective diffusivities are nearly tow orders of magnitude lower for these elements and of the order of 10{sup -12} m{sup 2}/s. Surface diffusion effects are found for Cs, Ni, Pa, Pb, Ra, Sn, Sr and Zr. Effective diffusivities for these elements are of the order of 10{sup -8} m{sup 2}/s. The surface diffusion effect should decrease in saline waters which is seen for Cs and Sr where there are data available. It is also deemed that Ra will have this effect because of its similarity with Sr. The other nuclides should also show this decrease but no data is available. Sorption and diffusion mechanisms in compacted bentonite are discussed in the report. In highly compacted bentonite, sorption and hence its distribution coefficient is not well defined, and a pore diffusion coefficient or a surface diffusion coefficient is not well defined either. Therefore, an apparent diffusion coefficient and a total concentration gradient should be more relevant in describing the diffusion process in compacted bentonite. 99 refs.

  2. 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

  3. Compact stellarators as reactors

    International Nuclear Information System (INIS)

    Lyon, J.F.; Valanju, P.; Zarnstorff, M.C.; Hirshman, S.; Spong, D.A.; Strickler, D.; Williamson, D.E.; Ware, A.

    2001-01-01

    Two types of compact stellarators are examined as reactors: two- and three-field-period (M=2 and 3) quasi-axisymmetric devices with volume-average =4-5% and M=2 and 3 quasi-poloidal devices with =10-15%. These low-aspect-ratio stellarator-tokamak hybrids differ from conventional stellarators in their use of the plasma-generated bootstrap current to supplement the poloidal field from external coils. Using the ARIES-AT model with B max =12T on the coils gives Compact Stellarator reactors with R=7.3-8.2m, a factor of 2-3 smaller R than other stellarator reactors for the same assumptions, and neutron wall loadings up to 3.7MWm -2 . (author)

  4. Compact torsatron reactors

    International Nuclear Information System (INIS)

    Lyon, J.F.; Carreras, B.A.; Lynch, V.E.; Tolliver, J.S.; Sviatoslavsky, I.N.

    1988-05-01

    Low-aspect-ratio torsatron configurations could lead to compact stellarator reactors with R 0 = 8--11m, roughly one-half to one-third the size of more conventional stellarator reactor designs. Minimum-size torsatron reactors are found using various assumptions. Their size is relatively insensitive to the choice of the conductor parameters and depends mostly on geometrical constraints. The smallest size is obtained by eliminating the tritium breeding blanket under the helical winding on the inboard side and by reducing the radial depth of the superconducting coil. Engineering design issues and reactor performance are examined for three examples to illustrate the feasibility of this approach for compact reactors and for a medium-size (R 0 ≅ 4 m,/bar a/ /approx lt/ 1 m) copper-coil ignition experiment. 26 refs., 11 figs., 7 tabs

  5. Compact Spreader Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  6. Compact fusion reactors

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Fusion research is currently to a large extent focused on tokamak (ITER) and inertial confinement (NIF) research. In addition to these large international or national efforts there are private companies performing fusion research using much smaller devices than ITER or NIF. The attempt to achieve fusion energy production through relatively small and compact devices compared to tokamaks decreases the costs and building time of the reactors and this has allowed some private companies to enter the field, like EMC2, General Fusion, Helion Energy, Lawrenceville Plasma Physics and Lockheed Martin. Some of these companies are trying to demonstrate net energy production within the next few years. If they are successful their next step is to attempt to commercialize their technology. In this presentation an overview of compact fusion reactor concepts is given.

  7. Compact nuclear fuel storage

    International Nuclear Information System (INIS)

    Kiselev, V.V.; Churakov, Yu.A.; Danchenko, Yu.V.; Bylkin, B.K.; Tsvetkov, S.V.

    1983-01-01

    Different constructions of racks for compact storage of spent fuel assemblies (FA) in ''coolin''g pools (CP) of NPPs with the BWR and PWR type reactors are described. Problems concerning nuclear and radiation safety and provision of necessary thermal conditions arising in such rack design are discussed. It is concluded that the problem of prolonged fuel storage at NPPs became Very actual for many countries because of retapdation of the rates of fuel reprocessing centers building. Application of compact storage racks is a promising solution of the problem of intermediate FA storage at NPPs. Such racks of stainless boron steel and with neutron absorbers in the from of boron carbide panels enable to increase the capacity of the present CP 2-2.6 times, and the period of FA storage in them up to 5-10 years

  8. Analysis of laboratory compaction methods of roller compacted concrete

    Science.gov (United States)

    Trtík, Tomáš; Chylík, Roman; Bílý, Petr; Fládr, Josef

    2017-09-01

    Roller-Compacted Concrete (RCC) is an ordinary concrete poured and compacted with machines typically used for laying of asphalt road layers. One of the problems connected with this technology is preparation of representative samples in the laboratory. The aim of this work was to analyse two methods of preparation of RCC laboratory samples with bulk density as the comparative parameter. The first method used dynamic compaction by pneumatic hammer. The second method of compaction had a static character. The specimens were loaded by precisely defined force in laboratory loading machine to create the same conditions as during static rolling (in the Czech Republic, only static rolling is commonly used). Bulk densities obtained by the two compaction methods were compared with core drills extracted from real RCC structure. The results have shown that the samples produced by pneumatic hammer tend to overestimate the bulk density of the material. For both compaction methods, immediate bearing index test was performed to verify the quality of compaction. A fundamental difference between static and dynamic compaction was identified. In static compaction, initial resistance to penetration of the mandrel was higher, after exceeding certain limit the resistance was constant. This means that the samples were well compacted just on the surface. Specimens made by pneumatic hammer actively resisted throughout the test, the whole volume was uniformly compacted.

  9. Infrared Spectroscopy Beamline Based on a Tabletop Storage Ring

    OpenAIRE

    Haque, Md. Monirul; Moon, Ahsa; Yamada, Hironari

    2012-01-01

    An optical beamline dedicated to the infrared (IR) spectroscopy has been constructed at MIRRORCLE, a tabletop storage ring. The beamline has been designed for the use of infrared synchrotron radiation (IRSR) emitted from a bending magnet of 156 mm bending radius with the acceptance angle of 355(H) × 138(V) mrad to obtain high flux. The IR emission is forced by an exactly circular optics, named photon storage ring (PhSR), placed around the electron orbit and is collected by a “magic mirror” as...

  10. Compaction of cereal grain

    OpenAIRE

    Wychowaniec, J.; Griffiths, I.; Gay, A.; Mughal, A.

    2013-01-01

    We report on simple shaking experiments to measure the compaction of a column of Firth oat grain. Such grains are elongated anisotropic particles with a bimodal polydispersity. In these experiments, the particle configurations start from an initially disordered, low-packing-fraction state and under vertical shaking evolve to a dense state with evidence of nematic-like structure at the surface of the confining tube. This is accompanied by an increase in the packing fraction of the grain.

  11. Compact nuclear reactor

    International Nuclear Information System (INIS)

    Juric, S.I.

    1975-01-01

    A compact nuclear reactor of the pressurized-water variety is described which has two separate parts separably engageable for ease of inspection, maintenance and repair. One of the parts is a pressure vessel having an active core and the other of the parts is a closure adapted on its lower surface with an integral steam generator. An integral pump, external pressurizer and control rods are provided which communicate with the active core when engaged to form a total unit. (U.S.)

  12. Compact power reactor

    International Nuclear Information System (INIS)

    Wetch, J.R.; Dieckamp, H.M.; Wilson, L.A.

    1978-01-01

    There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector

  13. CMS (Compact Muon Solenoid)

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The milestone workshops on LHC experiments in Aachen in 1990 and at Evian in 1992 provided the first sketches of how LHC detectors might look. The concept of a compact general-purpose LHC experiment based on a solenoid to provide the magnetic field was first discussed at Aachen, and the formal Expression of Interest was aired at Evian. It was here that the Compact Muon Solenoid (CMS) name first became public. Optimizing first the muon detection system is a natural starting point for a high luminosity (interaction rate) proton-proton collider experiment. The compact CMS design called for a strong magnetic field, of some 4 Tesla, using a superconducting solenoid, originally about 14 metres long and 6 metres bore. (By LHC standards, this warrants the adjective 'compact'.) The main design goals of CMS are: 1 - a very good muon system providing many possibilities for momentum measurement (physicists call this a 'highly redundant' system); 2 - the best possible electromagnetic calorimeter consistent with the above; 3 - high quality central tracking to achieve both the above; and 4 - an affordable detector. Overall, CMS aims to detect cleanly the diverse signatures of new physics by identifying and precisely measuring muons, electrons and photons over a large energy range at very high collision rates, while also exploiting the lower luminosity initial running. As well as proton-proton collisions, CMS will also be able to look at the muons emerging from LHC heavy ion beam collisions. The Evian CMS conceptual design foresaw the full calorimetry inside the solenoid, with emphasis on precision electromagnetic calorimetry for picking up photons. (A light Higgs particle will probably be seen via its decay into photon pairs.) The muon system now foresaw four stations. Inner tracking would use silicon microstrips and microstrip gas chambers, with over 10 7 channels offering high track finding efficiency. In the central CMS barrel, the tracking elements are

  14. Compact Information Representations

    Science.gov (United States)

    2016-08-02

    Department of Defense, Executive Services, Directorate (0704-0188).   Respondents should be aware that notwithstanding any other provision of law, no person...which lies in the mission of AFOSR. 15.  SUBJECT TERMS sparse sampling , principal components analysis 16.  SECURITY CLASSIFICATION OF: 17...approved for public release Contents 1 Training for Ph.D. Students and Postdoc Researchers 2 2 Papers 2 3 Summary of Proposed Research: Compact

  15. Separation of 90Sr from Purex high level waste and development of a 90Sr-90Y generator

    International Nuclear Information System (INIS)

    Ramanujam, A.; Dhami, P.S.; Chitnis, R.R.; Achuthan, P.V.; Kannan, R.; Gopalakrishnan, V.; Balu, K.

    2000-04-01

    90 Y (T 1/2 =64.2 h) finds several applications in nuclear medicine. It is formed from the decay of 90 Sr which has a long half-life of 28.8 years. 90 Sr can be used as a long-lasting source for the production of carrier-free 90 Y. 90 Sr itself is abundantly available in high level waste (HLW) of PUREX origin. The present studies deal with the separation of pure 90 Sr from HLW and the subsequent separation of 90 Y from 90 Sr. Actinides and some of the fission products like lanthanides, zirconium, molybdenum and cesium were first removed from the HLW using methods based on solvent extraction and ion-exchange studied earlier in our laboratory. The resulting waste solution was used as a feed for the present process. The separation of 90 Sr from HLW was based on radiochemical method which involved a repeated scavenging with ferric hydroxide followed by strontium carbonate precipitation. The separation of 90 Y from 90 Sr was achieved by membrane separation technique. A compact generator is developed for this separation using a commercially available polytetrafluoroethylene (PTFE) membrane, impregnated with indigenously synthesised 2-ethylhexyl 2-ethylhexyl phosphonic acid (KSM-17). Generator system overcomes the drawbacks associated with conventional solvent extraction and ion-exchange based generators. The product is in chloride form and is suitable for complexation studies. After gaining an operating experience of ∼3 years in generating carrier-free 90 Y at 2 mCi level for initial studies in radiotherapeutic applications, the process was scaled up for the production of about 12 mCi of 90 Y to be used for animal studies before its application to patients. Radiochemical and chemical purity of the product was critically assayed by radiometry, ICP-AES, etc. The process is amenable for further scaling up. (author)

  16. Finite element modelling of process-integrated powder coating by radial axial rolling of rings

    International Nuclear Information System (INIS)

    Frischkorn, J.; Kebriaei, R.; Reese, S.; Moll, H.; Theisen, W.; Husmann, T.; Meier, H.

    2011-01-01

    The process-integrated powder coating by radial axial rolling of rings represents a new hybrid production technique applied in the manufacturing of large ring-shaped work pieces with functional layers. It is thought to break some limitations that come along with the hot isostatic pressing (HIP) which is used nowadays to apply the powdery layer material onto the rolled substrate ring. Within the new process the compaction of the layer material is integrated into the ring rolling and HIP becomes dispensable. Following this approach the rolling of such compound rings brings up some new challenges. The volume of a solid ring stays nearly constant during the rolling. This behaviour can be exploited to determine the infeed of the rollers needed to reach the desired ring shape. Since volume consistency cannot be guaranteed for the rolling of a compound ring the choice of appropriate infeed of the rollers is still an open question. This paper deals with the finite element (FE) simulation of this new process. First, the material model that is used to describe the compaction of the layer material is shortly reviewed. The main focus of the paper is then put on a parameterized FE ring rolling model that incorporates a control system in order to stabilize the process. Also the differences in the behaviour during the rolling stage between a compound and a solid ring will be discussed by means of simulation results.

  17. 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)

  18. Computer simulations of compact toroid formation and acceleration

    International Nuclear Information System (INIS)

    Peterkin, R.E. Jr.; Sovinec, C.R.

    1990-01-01

    Experiments to form, accelerate, and focus compact toroid plasmas will be performed on the 9.4 MJ SHIVA STAR fast capacitor bank at the Air Force Weapons Laboratory during the 1990. The MARAUDER (magnetically accelerated rings to achieve ultrahigh directed energy and radiation) program is a research effort to accelerate magnetized plasma rings with the masses between 0.1 and 1.0 mg to velocities above 10 8 cm/sec and energies above 1 MJ. Research on these high-velocity compact toroids may lead to development of very fast opening switches, high-power microwave sources, and an alternative path to inertial confinement fusion. Design of a compact toroid accelerator experiment on the SHIVA STAR capacitor bank is underway, and computer simulations with the 2 1/2-dimensional magnetohydrodynamics code, MACH2, have been performed to guide this endeavor. The compact toroids are produced in a magnetized coaxial plasma gun, and the acceleration will occur in a configuration similar to a coaxial railgun. Detailed calculations of formation and equilibration of a low beta magnetic force-free configuration (curl B = kB) have been performed with MACH2. In this paper, the authors discuss computer simulations of the focusing and acceleration of the toroid

  19. Diffusion through statically compacted clay

    International Nuclear Information System (INIS)

    Ho, C.L.; Shebl, M.A.A.

    1994-01-01

    This paper presents experimental work on the effect of compaction on contaminant flow through clay liners. The experimental program included evaluation of soil properties, compaction, permeability and solute diffusion. A permeameter was built of non reactive materials to test samples compacted at different water contents and compactive efforts. The flow of a permeating solute, LiCl, was monitored. Effluent samples were collected for solute concentration measurements. The concentrations were measured by performing atomic adsorption tests. The analyzed results showed different diffusion characteristics when compaction conditions changed. At each compactive effort, permeability decreased as molding water content increased. Consequently, transit time (measured at relative concentration 50%) increased and diffusivity decreased. As compactive effort increased for soils compacted dry of optimum, permeability and diffusion decreased. On the other hand, as compactive effort increased for soils compacted wet of optimum, permeability and diffusivity increased. Tortuosity factor was indirectly measured from the diffusion and retardation rate. Tortuosity factor also decreased as placement water content was increased from dry of optimum to wet of optimum. Then decreases were more pronounced for low compactive effort tests. 27 refs., 7 figs., 5 tabs

  20. A MODEL FOR PRODUCING STABLE, BROADBAND TERAHERTZ COHERENT SYNCHROTRON RADIATION IN STORAGE RINGS

    International Nuclear Information System (INIS)

    Sannibale, Fernando; Byrd, John M.; Loftsdottir, Agusta; Martin, MichaelC.; Venturini, Marco

    2003-01-01

    We present a model for producing stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), enhancing higher frequency coherent emission and limits to stable emission due to a microbunching instability excited by the SR. We use this model to optimize the performance of a source for CSR emission

  1. Heavy ion storage rings

    International Nuclear Information System (INIS)

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs

  2. 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

  3. Diffusion of anions and cations in compacted sodium bentonite

    International Nuclear Information System (INIS)

    Muurinen, A.

    1994-02-01

    The thesis presents the results of studies on the diffusion mechanisms of anions and cations in compacted sodium bentonite, which is planned to be used as a buffer material in nuclear waste disposal in Finland. The diffusivities and sorption factors were determined by tracer experiments. The pore volume accessible to chloride, here defined as effective porosity, was determined as a function of bentonite density and electrolyte concentration in water, and the Stern-Gouy double-layer model was used to explain the observed anion exclusion. The sorption of Cs + and Sr 2+ was studied in loose and compacted bentonite samples as a function of the electrolyte concentration in solution. In order to obtain evidence of the diffusion of exchangeable cations, defined as surface diffusion, the diffusivities of Cs + and Sr 2+ in compacted bentonite were studied as a function of the sorption factor, which was varied by electrolyte concentration in solution. The measurements were performed both by a non-steady state method and by a through-diffusion method. (89 refs., 35 fig., 4 tab.)

  4. MECHANICS OF DYNAMIC POWDER COMPACTION PROCESS

    OpenAIRE

    Nurettin YAVUZ

    1996-01-01

    In recent years, interest in dynamic compaction methods of metal powders has increased due to the need to improve compaction properties and to increase production rates of compacts. In this paper, review of dynamic and explosive compaction of metal powders are given. An attempt is made to get a better understanding of the compaction process with the mechanicis of powder compaction.

  5. Ring artifacts removal from synchrotron CT image slices

    International Nuclear Information System (INIS)

    Wei Zhouping; Chapman, Dean; Wiebe, Sheldon

    2013-01-01

    Ring artifacts can occur in reconstructed images from x-ray Computerized Tomography (CT) as full or partial concentric rings superimposed on the scanned structures. Due to the data corruption by those ring artifacts in CT images, qualitative and quantitative analysis of these images are compromised. In this paper, we propose to correct the ring artifacts on the reconstructed synchrotron radiation (SR) CT image slices. The proposed correction procedure includes the following steps: (1). transform the reconstructed CT images into polar coordinates; (2) apply discrete two-dimensional (2D) wavelet transform to the polar image to decompose it into four image components: low pass band image component, as well as the components from horizontal, vertical and diagonal details bands; (3). apply 2D Fourier transform to the vertical details band image component only, since the ring artifacts become vertical lines in the polar coordinates; (4). apply Gaussian filtering in Fourier domain along the abscissa direction to suppress the vertical lines, since the information of the vertical lines in Fourier domain is completely condensed to that direction; (5). perform inverse Fourier transform to get the corrected vertical details band image component; (6). perform inverse wavelet transform to get the corrected polar image; (7). transform the corrected polar image back to Cartesian coordinates to get the CT image slice with reduced ring artifacts. This approach has been successfully used on CT data acquired from the Biomedical Imaging and Therapy (BMIT) beamline in Canadian Light Source (CLS), and the results show that the ring artifacts in original SR CT images have been effectively suppressed with all the structure information in the image preserved.

  6. The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

    Energy Technology Data Exchange (ETDEWEB)

    Podulka, W J; Greenly, J B; Anderson, D E; Glidden, S C; Hammer, D A; Omelchenko, Yu A; Sudan, R N [Cornell Univ., Ithaca, NY (United States). Laboratory of Plasma Studies

    1997-12-31

    The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10{sup 17} protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs.

  7. The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

    International Nuclear Information System (INIS)

    Podulka, W.J.; Greenly, J.B.; Anderson, D.E.; Glidden, S.C.; Hammer, D.A.; Omelchenko, Yu.A.; Sudan, R.N.

    1996-01-01

    The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10 17 protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs

  8. On arbitrarily graded rings

    Indian Academy of Sciences (India)

    58

    paper is devoted to the study of arbitrary rings graded through arbitrary sets. .... which recover certain multiplicative relations among the homogeneous components ... instance the case in which the grading set A is an Abelian group, where the ...

  9. The g-2 ring

    CERN Multimedia

    1974-01-01

    The precise measurement of "g-2", the anomalous magnetic moment of the muon, required a special muon storage ring with electrostatic focussing and very accurate knowledge of the magnetic bending field. For more details see under photo 7405430.

  10. Compact neutron flux monitor

    International Nuclear Information System (INIS)

    Madhavi, V.; Phatak, P.R.; Bahadur, C.; Bayala, A.K.; Jakati, R.K.; Sathian, V.

    2003-01-01

    Full text: A compact size neutron flux monitor has been developed incorporating standard boards developed for smart radiation monitors. The sensitivity of the monitors is 0.4cps/nV. It has been tested up to 2075 nV flux with standard neutron sources. It shows convincing results even in high flux areas like 6m away from the accelerator in RMC (Parel) for 106/107 nV. These monitors have a focal and remote display, alarm function with potential free contacts for centralized control and additional provision of connectivity via RS485/Ethernet. This paper describes the construction, working and results of the above flux monitor

  11. Compact ignition experiments

    International Nuclear Information System (INIS)

    Angelini, A.; Coppi, B.; Nassi, M.

    1992-01-01

    This paper reports on high magnetic field experiments which can be designed to investigate D-T ignition conditions based on present-day experimental results and theoretical understanding of plasma phenomena. The key machine elements are: large plasma currents, compact dimensions, tight aspect ratios, moderate elongations and significant triangularities of the plasma column. High plasma densities, strong ohmic heating, the needed degree of energy confinement, good plasma purity and robust stability against ideal and resistive instabilities can be achieved simultaneously. The Ignitor design incorporates all these characteristics and involves magnet technology developments, started with the Alcator experiment, that use cryogenically cooled normal conductors

  12. Compact LINAC for deuterons

    International Nuclear Information System (INIS)

    Kurennoy, S.S.; O'Hara, J.F.; Rybarcyk, L.J.

    2008-01-01

    We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

  13. LASL Compact Torus Program

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Bartsch, R.R.

    1981-01-01

    The Compact Torus (CT) concept includes any axisymmetric toroidal plasma configuration, which does not require the linking of any material through the hole in the torus. Thus, the magnet coils, vacuum vessel, etc., have a simple cylindrical or spherical geometry instead of the toroidal geometry required for Tokamaks and RFP's. This simplified geometry results in substantial engineering advantages in CT reactor embodiments while retaining the good confinement properties afforded by an axisymmetric toroidal plasma-field geometry. CT's can be classified into three major types by using the ion gyro radius rho/sub i/ and the magnitude of the maximum toroidal field B/sub tm/

  14. Compact Q-balls

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Losano, L.; Marques, M.A. [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Menezes, R. [Departamento de Ciências Exatas, Universidade Federal da Paraíba, 58297-000 Rio Tinto, PB (Brazil); Departamento de Física, Universidade Federal de Campina Grande, 58109-970 Campina Grande, PB (Brazil); Rocha, R. da [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, 09210-580 Santo André (Brazil)

    2016-07-10

    In this work we deal with non-topological solutions of the Q-ball type in two space–time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  15. [Liesegang's rings resembling helminthiasis].

    Science.gov (United States)

    Zámecník, M; Riedl, I

    1996-12-01

    So called Liesegang's rings are lamellar corpuscles which develop after periodical precipitation of oversaturated solutions in gel medium. They can occur in cysts, closed cavities, inflammatory exudates and necroses. They resemble parasitic eggs, larvae or adult forms. A case of 28-year-old woman is presented with many Liesegang's rings in a stuff from dilated renal calyx. Their preliminary evaluation considered helminths, especially Dioctophyma renale.

  16. Storage ring group summary

    International Nuclear Information System (INIS)

    King, N.M.

    1980-01-01

    The Storage Ring Group set out to identify and pursue salient problems in accelerator physics for heavy ion fusion, divorced from any particular reference design concept. However, it became apparent that some basic parameter framework was required to correlate the different study topics. As the Workshop progressed, ring parameters were modified and updated. Consequently, the accompanying papers on individual topics will be found to refer to slightly varied parameters, according to the stage at which the different problems were tackled

  17. The rings of Uranus

    Science.gov (United States)

    Elliot, J. L.; Dunham, E.; Mink, D.

    1977-01-01

    A description is given of the observation of five brief occultations of the star SAO 158687 which occurred both before and after its occultation by Uranus on March 10, 1977. The events were observed with a three-channel occultation photometer, attached to a 91-cm telescope. The observations indicate that at least five rings encircle the planet Uranus. Possible reasons for the narrowness of the Uranus rings are discussed.

  18. On zero divisor graph of unique product monoid rings over Noetherian reversible ring

    Directory of Open Access Journals (Sweden)

    Ebrahim Hashemi

    2016-02-01

    Full Text Available Let $R$ be an associative ring with identity and $Z^*(R$ be its set of non-zero zero divisors.  The zero-divisor graph of $R$, denoted by $Gamma(R$, is the graph whose vertices are the non-zero  zero-divisors of  $R$, and two distinct vertices $r$ and $s$ are adjacent if and only if $rs=0$ or $sr=0$.  In this paper, we bring some results about undirected zero-divisor graph of a monoid ring over reversible right (or left Noetherian ring $R$. We essentially classify the diameter-structure of this graph and show that $0leq mbox{diam}(Gamma(Rleq mbox{diam}(Gamma(R[M]leq 3$. Moreover, we give a characterization for the possible diam$(Gamma(R$ and diam$(Gamma(R[M]$, when $R$ is a reversible Noetherian ring and $M$ is a u.p.-monoid. Also, we study relations between the girth of $Gamma(R$ and that of $Gamma(R[M]$.

  19. Calibration Device Designed for proof ring used in SCC Experiment

    Science.gov (United States)

    Hu, X. Y.; Kang, Z. Y.; Yu, Y. L.

    2017-11-01

    In this paper, a calibration device for proof ring used in SCC (Stress Corrosion Cracking) experiment was designed. A compact size loading device was developed to replace traditional force standard machine or a long screw nut. The deformation of the proof ring was measured by a CCD (Charge-Coupled Device) during the calibration instead of digital caliper or a dial gauge. The calibration device was verified at laboratory that the precision of force loading is ±0.1% and the precision of deformation measurement is ±0.002mm.

  20. Ring-array processor distribution topology for optical interconnects

    Science.gov (United States)

    Li, Yao; Ha, Berlin; Wang, Ting; Wang, Sunyu; Katz, A.; Lu, X. J.; Kanterakis, E.

    1992-01-01

    The existing linear and rectangular processor distribution topologies for optical interconnects, although promising in many respects, cannot solve problems such as clock skews, the lack of supporting elements for efficient optical implementation, etc. The use of a ring-array processor distribution topology, however, can overcome these problems. Here, a study of the ring-array topology is conducted with an aim of implementing various fast clock rate, high-performance, compact optical networks for digital electronic multiprocessor computers. Practical design issues are addressed. Some proof-of-principle experimental results are included.

  1. Is the Modern Marine 87Sr/86Sr Cycle Balanced?

    Science.gov (United States)

    Peucker-Ehrenbrink, B.

    2017-12-01

    The marine 87Sr/86Sr record is one of the best-reconstructed isotope records with thousands of high quality measurements spanning the past 800 million years. It records a global signal of tectonic, biotic and climatic processes on Earth. Yet despite decades of research we still do not know whether the current marine Sr budget is in steady state. Studies of the marine 88Sr/86Sr record indicate that sources and sinks do not balance. The magnitude and isotope composition of the terrestrial inputs are being debated, and the magnitude and temporal variability of unradiogenic contributions are not well constrained. Here I provide a revised assessment of all continental sources of Sr to the ocean, including river runoff, submarine groundwater discharge (Beck et al., 2013), dissolution of riverine suspended matter in seawater and dissolution of volcanic ash deposited on the ocean (Jones et al., 2012). I contrast continental sources of Sr with estimates of marine sources of Sr to seawater, specifically high- and low-temperature submarine hydrothermal fluids, as well as diffusive diagenetic fluxes. Best current data imply that unradiogenic submarine hydrothermal inputs to seawater are insufficient to balance the flux of radiogenic continental Sr. The revised assessment of riverine contributions is based on Sr data for almost 230 rivers, an increasing amount of time-series data for such rivers, as well as river discharge and sediment flux data for more than 2000 rivers. Regional sampling biases have been corrected with the aid of digital bedrock maps, specifically along the western margin of North America, East Africa and the large drainage region of Arabia, India and SE Asia. Significant uncertainty in the chemical and isotopic compositions of runoff from Greenland and East Africa remains. The main uncertainty in the budget, however, is related to the possibility that modern rivers do not represent the pre-anthropogenic (natural) state of continental runoff (e.g. Ganges

  2. Einstein Ring in Distant Universe

    Science.gov (United States)

    2005-06-01

    population. The far away lensed galaxy, however, is extremely active, having recently experienced bursts of star formation. It is a compact galaxy, 7,000 light-years across. "Because the gravitational pull of matter bends the path of light rays, astronomical objects - stars, galaxies and galaxy clusters - can act like lenses, which magnify and severely distort the images of galaxies behind them, producing weird pictures as in a hall of mirrors", explains Chris Lidman (ESO), co-discover of the new cosmic mirage. In the most extreme case, where the foreground lensing galaxy and the background galaxy are perfectly lined up, the image of the background galaxy is stretched into a ring. Such an image is known as an Einstein ring, because the formula for the bending of light, first described in the early twentieth century by Chwolson and Link, uses Albert Einstein's theory of General Relativity. Gravitational lensing provides a very useful tool with which to study the Universe. As "weighing scales", it provides a measure of the mass within the lensing body, and as a "magnifying glass", it allows us to see details in objects which would otherwise be beyond the reach of current telescopes. From the image, co-worker David Valls-Gabaud (CFHT), using state-of-the-art modelling algorithms, could deduce the mass of the galaxy acting as a lens - it is almost one million million suns. More information The paper describing this research has been published as a Letter to the Editor in Astronomy and Astrophysics, volume 436, L21-L25 ("Discovery of a high-redshift Einstein ring", by R.A. Cabanac, D. Valls-Gabaud, A.O. Jaunsen, C. Lidman, and H. Jerjen). The paper is available for download in PDF format from the A&A web site.

  3. Physicochemical compatibility of SrCeO3 with potential SOFC cathodes

    International Nuclear Information System (INIS)

    Tolchard, J.; Grande, T.

    2007-01-01

    The chemical and physical compatibility of SrCeO 3 is investigated with respect to LaMO 3 (M=Mn, Fe, Co) and La 2-x Sr x NiO 4 (x=0, 0.8), via the reaction of fine-grained powder compacts and solid-state diffusion couples. Compositions were chosen so as to give predictive insight into possible candidate materials for all-oxide electrochemical devices. Results show the primary reaction in these systems to be the dissolution of SrO from SrCeO 3 into the LaMO 3 /La 2-x Sr x NiO 4 , and corresponding formation of La-doped CeO 2 . Reaction kinetics are observed to be relatively fast, with element profiles suggesting the diffusion of Sr 2+ in ceria to be surprisingly rapid. It is demonstrated that perovskite starting materials represent poor candidates for use with SrCeO 3 , reacting completely to form Ruddlesden-Popper/K 2 NiF 4 type oxides. Reaction with La 2 NiO 4 is less pronounced, and formation of secondary phases suppressed for the composition La 1.2 Sr 0.8 NiO 4 . It is thus concluded that Ruddlesden-Popper type oxides represent good candidate materials for use with a SrCeO 3 -based electrolytes when doped with appropriate levels of Sr. - Graphical abstract: Assessment of the SrCeO 3 proton conductor shows this material to have poor chemical compatibility with LaMO 3 perovskite systems, but predicts coexistence with Ruddlesden-Popper type oxides

  4. Scalable Nonlinear Compact Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Debojyoti [Argonne National Lab. (ANL), Argonne, IL (United States); Constantinescu, Emil M. [Univ. of Chicago, IL (United States); Brown, Jed [Univ. of Colorado, Boulder, CO (United States)

    2014-04-01

    In this work, we focus on compact schemes resulting in tridiagonal systems of equations, specifically the fifth-order CRWENO scheme. We propose a scalable implementation of the nonlinear compact schemes by implementing a parallel tridiagonal solver based on the partitioning/substructuring approach. We use an iterative solver for the reduced system of equations; however, we solve this system to machine zero accuracy to ensure that no parallelization errors are introduced. It is possible to achieve machine-zero convergence with few iterations because of the diagonal dominance of the system. The number of iterations is specified a priori instead of a norm-based exit criterion, and collective communications are avoided. The overall algorithm thus involves only point-to-point communication between neighboring processors. Our implementation of the tridiagonal solver differs from and avoids the drawbacks of past efforts in the following ways: it introduces no parallelization-related approximations (multiprocessor solutions are exactly identical to uniprocessor ones), it involves minimal communication, the mathematical complexity is similar to that of the Thomas algorithm on a single processor, and it does not require any communication and computation scheduling.

  5. Compact magnetic fusion systems

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K.

    1983-12-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak/sup 1/ and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics.

  6. Compact magnetic fusion systems

    International Nuclear Information System (INIS)

    Linford, R.K.

    1983-01-01

    If the core (first wall, blanket, shield, and magnet coils) of fusion reactor systems could be made smaller in mass and volume for a given net electric power output than is usually predicted for the mainline tokamak 1 and mirror concepts, the cost of the technological development of the core and the construction of power plants might be significantly reduced. Although progress in plasma physics and engineering approaches should continue to yield improvements in reactor designs, certain physics features of the mainline concepts may prevent major reductions in the size of the core without straining the limits of technology. However, more than a factor of ten reduction in volume and mass of the core, at constant output power, may be possible for a class of toroidal confinement concepts in which the confining magnetic fields are supported more by currents flowing in the plasma than those in the external coils. In spite of this dramatic increase in power density (ratio of total thermal output power to the volume of the core), the design of compact systems need not rely on any materials requirements that are qualitatively more difficult than those proposed for the lower-power-density mainline fusion concepts. In some respects compact systems require less of an extension of existing technology, e.g. magnetics

  7. Diffusion in compacted betonite

    International Nuclear Information System (INIS)

    Muurinen, A.; Rantanen, J.

    1985-01-01

    The objective of this report is to collect the literature bearing on the diffusion in compacted betonite, which has been suggested as possible buffer material for the disposal of spent fuel. Diffusion in a porous, water-saturated material is usually described as diffusion in the pore-water where sorption on the solid matter can delay the migration in the instationary state. There are also models which take into consideration that the sorbed molecules can also move while being sorbed. Diffusion experiments in compacted bentonite have been reported by many authors. Gases, anions, cations and actinides have been used as diffusing molecules. The report collects the results and the information on the measurement methods. On the basis of the results can be concluded that different particles possibly follow different diffusion mechanisms. The parameters which affect the diffusion seem to be for example the size, the electric charge and the sorption properties of the diffusing molecule. The report also suggest the parameters to be used in the diffusion calculation of the safety analyses of spent fuel disposal. (author)

  8. Compact Infrasonic Windscreen

    Science.gov (United States)

    Zuckerwar, Allan J.; Shams, Qamar A.; Sealey, Bradley S.; Comeaux, Toby

    2005-01-01

    A compact windscreen has been conceived for a microphone of a type used outdoors to detect atmospheric infrasound from a variety of natural and manmade sources. Wind at the microphone site contaminates received infrasonic signals (defined here as sounds having frequencies <20 Hz), because a microphone cannot distinguish between infrasonic pressures (which propagate at the speed of sound) and convective pressure fluctuations generated by wind turbulence. Hence, success in measurement of outdoor infrasound depends on effective screening of the microphone from the wind. The present compact windscreen is based on a principle: that infrasound at sufficiently large wavelength can penetrate any barrier of practical thickness. Thus, a windscreen having solid, non-porous walls can block convected pressure fluctuations from the wind while transmitting infrasonic acoustic waves. The transmission coefficient depends strongly upon the ratio between the acoustic impedance of the windscreen and that of air. Several materials have been found to have impedance ratios that render them suitable for use in constructing walls that have practical thicknesses and are capable of high transmission of infrasound. These materials (with their impedance ratios in parentheses) are polyurethane foam (222), space shuttle tile material (332), balsa (323), cedar (3,151), and pine (4,713).

  9. Compact electrostatic comb actuator

    Science.gov (United States)

    Rodgers, M. Steven; Burg, Michael S.; Jensen, Brian D.; Miller, Samuel L.; Barnes, Stephen M.

    2000-01-01

    A compact electrostatic comb actuator is disclosed for microelectromechanical (MEM) applications. The actuator is based upon a plurality of meshed electrostatic combs, some of which are stationary and others of which are moveable. One or more restoring springs are fabricated within an outline of the electrostatic combs (i.e. superposed with the moveable electrostatic combs) to considerably reduce the space required for the actuator. Additionally, a truss structure is provided to support the moveable electrostatic combs and prevent bending or distortion of these combs due to unbalanced electrostatic forces or external loading. The truss structure formed about the moveable electrostatic combs allows the spacing between the interdigitated fingers of the combs to be reduced to about one micron or less, thereby substantially increasing the number of active fingers which can be provided in a given area. Finally, electrostatic shields can be used in the actuator to substantially reduce unwanted electrostatic fields to further improve performance of the device. As a result, the compact electrostatic comb actuator of the present invention occupies only a fraction of the space required for conventional electrostatic comb actuators, while providing a substantial increase in the available drive force (up to one-hundred times).

  10. Development task of compact reactor

    International Nuclear Information System (INIS)

    Kurushima, Morihiro

    1982-01-01

    In the Ministry of International Trade and Industry, studies proceed on the usage of compact medium and small LWRs. As such, the reactors from 100 to 200 MW may meet varieties of demands in scale and kind in view of the saving of petroleum and the economy of nuclear power. In this case, the technology of light water reactors with already established safety will be suitable for the development of compact reactors. The concept of ''nuclear power community'' using the compact reactors in local society and industrial zones was investigated. The following matters are described: need for the introduction of compact reactors, the survey on the compact reactor systems, and the present status and future problems for compact reactor usage. (J.P.N.)

  11. 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.

  12. The United Nations Global Compact

    DEFF Research Database (Denmark)

    Rasche, Andreas; Waddock, Sandra; McIntosh, Malcolm

    2013-01-01

    This article reviews the interdisciplinary literature on the UN Global Compact. The review identifies three research perspectives, which scholars have used to study the UN Global Compact so far: a historical perspective discussing the Global Compact in the context of UN-business relations...... key empirical as well as conceptual scholarly contributions. The remainder of this article contains focused summaries of the articles selected for this Special Issue. All articles are introduced and evaluated against the background of the three research perspectives....

  13. Compact toroid formation, compression, and acceleration

    International Nuclear Information System (INIS)

    Degnan, J.H.; Peterkin, R.E. Jr.; Baca, G.P.; Beason, J.D.; Bell, D.E.; Dearborn, M.E.; Dietz, D.; Douglas, M.R.; Englert, S.E.; Englert, T.J.; Hackett, K.E.; Holmes, J.H.; Hussey, T.W.; Kiuttu, G.F.; Lehr, F.M.; Marklin, G.J.; Mullins, B.W.; Price, D.W.; Roderick, N.F.; Ruden, E.L.; Sovinec, C.R.; Turchi, P.J.; Bird, G.; Coffey, S.K.; Seiler, S.W.; Chen, Y.G.; Gale, D.; Graham, J.D.; Scott, M.; Sommars, W.

    1993-01-01

    Research on forming, compressing, and accelerating milligram-range compact toroids using a meter diameter, two-stage, puffed gas, magnetic field embedded coaxial plasma gun is described. The compact toroids that are studied are similar to spheromaks, but they are threaded by an inner conductor. This research effort, named MARAUDER (Magnetically Accelerated Ring to Achieve Ultra-high Directed Energy and Radiation), is not a magnetic confinement fusion program like most spheromak efforts. Rather, the ultimate goal of the present program is to compress toroids to high mass density and magnetic field intensity, and to accelerate the toroids to high speed. There are a variety of applications for compressed, accelerated toroids including fast opening switches, x-radiation production, radio frequency (rf) compression, as well as charge-neutral ion beam and inertial confinement fusion studies. Experiments performed to date to form and accelerate toroids have been diagnosed with magnetic probe arrays, laser interferometry, time and space resolved optical spectroscopy, and fast photography. Parts of the experiment have been designed by, and experimental results are interpreted with, the help of two-dimensional (2-D), time-dependent magnetohydrodynamic (MHD) numerical simulations. When not driven by a second discharge, the toroids relax to a Woltjer--Taylor equilibrium state that compares favorably to the results of 2-D equilibrium calculations and to 2-D time-dependent MHD simulations. Current, voltage, and magnetic probe data from toroids that are driven by an acceleration discharge are compared to 2-D MHD and to circuit solver/slug model predictions. Results suggest that compact toroids are formed in 7--15 μsec, and can be accelerated intact with material species the same as injected gas species and entrained mass ≥1/2 the injected mass

  14. 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.

  15. Dipole Magnets for the LHeC Ring-Ring Option

    CERN Document Server

    Tommasini, D; Chritin, R

    2012-01-01

    The Ring-Ring option of a Large Hadron electron Collider (LHeC) requires 3080 bending magnets, 5.35-meter-long each providing a magnetic field ranging from 0.0127 T at 10 GeV to 0.0763 T at 60 GeV. Main issues in the design of these magnets are the very low injection field, constituting a challenge in achieving a satisfactory field reproducibility from cycle to cycle, and the required compactness to fit in the existing LHC tunnel. This paper describes and discusses a design meeting these requirements, together with its experimental validation by the manufacture and measurement of a 400-mm-long magnet model.

  16. 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.

  17. 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

  18. 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)

  19. 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.

  20. 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)

  1. Compact particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo-Decanini, Juan M.

    2017-08-29

    A compact particle accelerator having an input portion configured to receive power to produce particles for acceleration, where the input portion includes a switch, is provided. In a general embodiment, a vacuum tube receives particles produced from the input portion at a first end, and a plurality of wafer stacks are positioned serially along the vacuum tube. Each of the plurality of wafer stacks include a dielectric and metal-oxide pair, wherein each of the plurality of wafer stacks further accelerate the particles in the vacuum tube. A beam shaper coupled to a second end of the vacuum tube shapes the particles accelerated by the plurality of wafer stacks into a beam and an output portion outputs the beam.

  2. Compact vacuum insulation embodiments

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  3. Compact vacuum insulation

    Science.gov (United States)

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  4. The Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    Schmidt, J.

    1987-01-01

    The author discusses his lab's plan for completing the Compact Ignition Tokamak (CIT) conceptual design during calendar year 1987. Around July 1 they froze the subsystem envelopes on the device to continue with the conceptual design. They did this by formalizing a general requirements document. They have been developing the management plan and submitted a version to the DOE July 10. He describes a group of management activities. They released the vacuum vessel Request For Proposals (RFP) on August 5. An RFP to do a major part of the system engineering on the device is being developed. They intend to assemble the device outside of the test cell, then move it into the the test cell, install it there, and bring to the test cell many of the auxiliary facilities from TFTR, for example, power supplies

  5. Compact cryocooler heat exchangers

    International Nuclear Information System (INIS)

    Luna, J.; Frederking, T.H.K.

    1991-01-01

    Compact heat exchangers are subject to different constraints as a room temperature gas is cooled down by a cold stream returning from a JT valve (or a similar cryoprocess component). In particular, the optimization of exchangers for liquid helium systems has to cover a wide range in temperature and density of the fluid. In the present work we address the following thermodynamic questions: 1. The optimization of intermediate temperatures which optimize stage operation (a stage is assumed to have a constant cross section); 2. The optimum temperature difference available for best overall economic performance values. The results are viewed in the context of porous media concepts applied to rather low speeds of fluid flow in narrow passages. In this paper examples of fluid/solid constraints imposed in this non-classical low temperature area are presented

  6. Compact semiconductor lasers

    CERN Document Server

    Yu, Siyuan; Lourtioz, Jean-Michel

    2014-01-01

    This book brings together in a single volume a unique contribution by the top experts around the world in the field of compact semiconductor lasers to provide a comprehensive description and analysis of the current status as well as future directions in the field of micro- and nano-scale semiconductor lasers. It is organized according to the various forms of micro- or nano-laser cavity configurations with each chapter discussing key technical issues, including semiconductor carrier recombination processes and optical gain dynamics, photonic confinement behavior and output coupling mechanisms, carrier transport considerations relevant to the injection process, and emission mode control. Required reading for those working in and researching the area of semiconductors lasers and micro-electronics.

  7. Almost ring theory

    CERN Document Server

    2003-01-01

    This book develops thorough and complete foundations for the method of almost etale extensions, which is at the basis of Faltings' approach to p-adic Hodge theory. The central notion is that of an "almost ring". Almost rings are the commutative unitary monoids in a tensor category obtained as a quotient V-Mod/S of the category V-Mod of modules over a fixed ring V; the subcategory S consists of all modules annihilated by a fixed ideal m of V, satisfying certain natural conditions. The reader is assumed to be familiar with general categorical notions, some basic commutative algebra and some advanced homological algebra (derived categories, simplicial methods). Apart from these general prerequisites, the text is as self-contained as possible. One novel feature of the book - compared with Faltings' earlier treatment - is the systematic exploitation of the cotangent complex, especially for the study of deformations of almost algebras.

  8. Burial trench dynamic compaction demonstration at a humid site

    International Nuclear Information System (INIS)

    Spalding, B.P.

    1985-01-01

    This task has the objective of determining the degree of consolidation which can be achieved by dynamic compaction of a closed burial trench within a cohesive soil formation. A seven-year-old burial trench in Solid Waste Storage Area (SWSA) 6 of Oak Ridge National Laboratory (ORNL) was selected for this demonstration. This 251 m 3 trench contained about 80 Ci of mixed radionuclides, mostly 90 Sr, in 25 m 3 of waste consisting of contaminated equipment, dry solids, and demolition debris. Prior to compaction, a total trench void space of 79 m 3 was measured by pumping the trench full of water with corrections for seepage. Additional pre-compaction characterization included trench cap bulk density (1.68 kg/L), trench cap permeability (3 x 10 -7 m/s), and subsurface waste/backfill hydraulic conductivity (>0.01 m/s). Compaction was achieved by repeatedly dropping a 4-ton steel-reinforced concrete cylinder from heights of 4 to 8 m using the whipline of a 70-ton crane. The average trench ground surface was depressed 0.79 m, with some sections over 2 m, yielding a surveyed volumetric depression which totaled to 64% of the measured trench void space. Trench cap (0 to 60 cm) bulk density and permeability were not affected by compaction indicating that the consolidation was largely subsurface. Neither surface nor airborne radioactive contamination were observed during repeated monitoring during the demonstration. Dynamic compaction was shown to be an excellent and inexpensive (i.e., about $20/m 2 ) method to collapse trench void space, thereby hastening subsidence and stabilizing the land surface. 15 refs., 10 figs., 3 tabs

  9. Left-handed compact MIMO antenna array based on wire spiral resonator for 5-GHz wireless applications

    Science.gov (United States)

    Alqadami, Abdulrahman Shueai Mohsen; Jamlos, Mohd Faizal; Soh, Ping Jack; Rahim, Sharul Kamal Abdul; Narbudowicz, Adam

    2017-01-01

    A compact coplanar waveguide-fed multiple-input multiple-output antenna array based on the left-handed wire loaded spiral resonators (SR) is presented. The proposed antenna consists of a 2 × 2 wire SR with two symmetrical microstrip feed lines, each line exciting a 1 × 2 wire SR. Left-handed metamaterial unit cells are placed on its reverse side and arranged in a 2 × 3 array. A reflection coefficient of less than -16 dB and mutual coupling of less than -28 dB are achieved at 5.15 GHz WLAN band.

  10. Ring cavity surface emitting semiconductor lasers

    International Nuclear Information System (INIS)

    Mujagic, E.

    2010-01-01

    Quantum cascade lasers (QCLs) are electrically driven semiconductor lasers, which have undergone a steady improvement since the first demonstration in 1994. These are now well established as reliable sources of coherent light in the mid-infrared (MIR) and terahertz (THz)range of the electromagnetic spectrum (3-300 μm). The rapid progress of this type of lasers is based on a high degree of freedom in tailoring the emission wavelength within a large variety of semiconductor heterostructure designs and materials. These properties have attracted the attention of various applications such as gas analysis, chemical sensing, spectral imaging and free-space telecommunication. In order to improve the selectivity, sensitivity and efficiency of today's sensor systems, high optical power, continuous wave and room temperature performance, single-mode operation and low divergence optical beams, are highly desirable qualities of a compact laser source in this field of research. Since all of these features cannot be provided by a conventional edge-emitting device at the same time, research has put focus on the development of surface emitting devices. Nowadays, the vertical cavity surface emitting lasers (VCSELs) are the most prominent representative for this type of light emitters. With its capability of producing narrow circular beams, the feasibility of two-dimensional arrays and on-wafer testing, such a coherent light source results in a reduction of the fabrication effort and production costs. Since the radiation in QCLs is strictly polarized normal to the epitaxial layer plane, fabrication of VCSELs based on QC structures is not viable. The subject of this work is the design and realization of 'ring cavity surface emitting lasers' (ring-CSELs). This type of lasers employs a circular ring cavity and a resonant distributed feedback (DFB) surface grating. Ring-CSELs were fabricated on the basis of MIR and THz QC structures, which cover a wavelength range from 4 μm to 93

  11. Concentric circular ring and nanodisk optical antenna enhanced multispectral quantum dot infrared photodetector with spectral localization

    International Nuclear Information System (INIS)

    Zhang, Yingjie; Kemsri, Thitikorn; Li, Lin; Lu, Xuejun; Gu, Guiru

    2017-01-01

    In this paper, we report a concentric circular ring and nanodisk plasmonic optical antenna (POA) enhanced multispectral quantum dot infrared photodetector (QDIP). The circular ring and the nanodisk POA structures are designed to have plasmonic resonant wavelengths in the longwave infrared (LWIR) and the midwave infrared (MWIR) spectral regimes, respectively. The electric field ( E -field) distributions are simulated and show spectral localization due to the distinct plasmonic resonant wavelengths of the POA structures. The circular ring is found to enhance the E -fields in the nanodisk regions due to the mutual coupling. A concentric circular ring and nanodisk POA enhanced multispectral QDIP was fabricated and tested. Multispectral enhancement was observed. The enhancement is compared to that of a QDIP with only the circular ring POA structure. The experiment data agree with the simulation. The concentric circular ring and nanodisk POA provides a compact planar structure for multispectral QDIP enhancement. (paper)

  12. The covariant chiral ring

    Energy Technology Data Exchange (ETDEWEB)

    Bourget, Antoine; Troost, Jan [Laboratoire de Physique Théorique, École Normale Supérieure, 24 rue Lhomond, 75005 Paris (France)

    2016-03-23

    We construct a covariant generating function for the spectrum of chiral primaries of symmetric orbifold conformal field theories with N=(4,4) supersymmetry in two dimensions. For seed target spaces K3 and T{sup 4}, the generating functions capture the SO(21) and SO(5) representation theoretic content of the chiral ring respectively. Via string dualities, we relate the transformation properties of the chiral ring under these isometries of the moduli space to the Lorentz covariance of perturbative string partition functions in flat space.

  13. Vortex and source rings

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre

    2017-01-01

    The velocity field, vector potential and velocity gradient of a vortex ring is derived in this chapter. The Biot-Savart law for the vector potential and velocity is expressed in a first section. Then, the flow is derived at specific locations: on the axis, near the axis and in the far field where...... the analogy to a doublet field is made. The following section derive the value of the vector potential and velocity field in the full domain. The expression for the velocity gradient is also provided since it may be relevant in a simulation with vortex particles and vortex rings. Most of this chapter...

  14. The Saturnian rings

    International Nuclear Information System (INIS)

    Alfven, H.

    1975-09-01

    The structure of the Saturnian rings is traditionally believed to be due to resonances caused by Mimas (and possibly other satellites). It is shown that both theoretical and observational evidence rule out this interpretation. The increased observational accuracy on one hand and the increased understanding of the cosmogonic processes on the other makes it possible to explain the structure of the ring system as a product of condensation from a partially corotating plasma. In certain respects the agreement between theory and observations is about 1%. (Auth.)

  15. RINGED ACCRETION DISKS: INSTABILITIES

    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)

    2016-04-01

    We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends on the dimensionless spin of the rotating attractor.

  16. Compact magnetic fusin reactor concepts

    International Nuclear Information System (INIS)

    Chung, K.M.

    1984-01-01

    Compact, high-power-density approaches to fusion power represent alternatives to main-line fusion concepts, Tokamaks and mirrors. If technological issues are resolved, theses approaches would yield small, low-cost fusion power plants. This survey reviews the principal physics and technology employed by leading compact magnetic fusion plants. (Author)

  17. Solid targetry for compact cyclotrons

    International Nuclear Information System (INIS)

    Comor, J.

    2004-01-01

    In this presentation authors present experimental results of solid targetry for compact cyclotrons. It is concluded: Solid targetry is not restricted to large accelerator centers anymore; Small and medium scale radioisotope production is feasible with compact cyclotrons; The availability of versatile solid target systems is expected to boost the radiochemistry of 'exotic' positron emitters

  18. Roller-compacted concrete pavements.

    Science.gov (United States)

    2010-09-01

    Roller-compacted concrete (RCC) gets its name from the heavy vibratory steel drum and rubber-tired rollers used to help compact it into its final form. RCC has similar strength properties and consists of the same basic ingredients as conventional con...

  19. Machine for compacting solid residues

    International Nuclear Information System (INIS)

    Herzog, J.

    1981-11-01

    Machine for compacting solid residues, particularly bulky radioactive residues, constituted of a horizontally actuated punch and a fixed compression anvil, in which the residues are first compacted horizontally and then vertically. Its salient characteristic is that the punch and the compression anvil have embossments on the compression side and interpenetrating plates in the compression position [fr

  20. EVOLUTION OF A RING AROUND THE PLUTO–CHARON BINARY

    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 St., Cambridge, MA 02138 (United States)

    2015-08-10

    We consider the formation of satellites around the Pluto–Charon binary. An early collision between the two partners likely produced the binary and a narrow ring of debris, out of which arose the moons Styx, Nix, Kerberos, and Hydra. How the satellites emerged from the compact ring is uncertain. Here we show that a particle ring spreads from physical collisions and collective gravitational scattering, similar to migration. Around a binary, these processes take place in the reference frames of “most circular” orbits, akin to circular ones in a Keplerian potential. Ring particles damp to these orbits and avoid destructive collisions. Damping and diffusion also help particles survive dynamical instabilities driven by resonances with the binary. In some situations, particles become trapped near resonances that sweep outward with the tidal evolution of the Pluto–Charon binary. With simple models and numerical experiments, we show how the Pluto–Charon impact ring may have expanded into a broad disk, out of which grew the circumbinary moons. In some scenarios, the ring can spread well beyond the orbit of Hydra, the most distant moon, to form a handful of smaller satellites. If these small moons exist, New Horizons will find them.

  1. Development status of compact containment BWR

    International Nuclear Information System (INIS)

    Heki, H.; Nakamaru, M.; Mori, H.; Sekiguchi, K.; Kuroki, M.; Arai, K.; Hida, T.

    2005-01-01

    In Japan, increase of nuclear plant unit capacity has been promoted to take advantage of economies of scale while further enhancing safety and reliability. As a result, more than 50 units of nuclear power plants are playing important role in electric power generation. However, the factors, such as stagnant growth in the recent electricity demand, limitation in electricity grid capacity and limited in initial investment avoiding risk, will not be in favor of large plant outputs. The reactor concept considered in this paper has a small power output, a compact containment and a simplified BWR configuration with comprehensive safety features. The Compact Containment Boiling Water Reactor (CCR), which is being developed with matured BWR technologies together with innovative systems/components, will provide attractiveness for the energy market in the world due to its flexibility in energy demands as well as in site conditions, its high potential in reducing investment risk and its safety feature facilitating public acceptance. The flexibility is achieved by CCR's mid/small power output of 400 MWe class and capability of long operating cycle (refueling intervals). The high investment potential is expected from CCR's simplification/innovation in design such as natural circulation core cooling with the bottom located short core, top mounted upper entry control rod drives (CRDs) with ring-type dryers and simplified ECCS system with high pressure resistible primary containment vessel (PCV) concept. The natural circulation core eliminates recirculation pumps as well as needs for maintenance of such pumps. The top mounted upper entry CRDs enable the bottom located short core in RPV. The safety feature mainly consists of large water inventory above the core without large penetration below the top of the core, passive cooling system by isolation condenser (IC), high pressure resistible PCV and in-vessel retention (IVR) capability. The large inventory increases the system response

  2. 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...

  3. 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.

  4. Flushing Ring for EDM

    Science.gov (United States)

    Earwood, L.

    1985-01-01

    Removing debris more quickly lowers cutting time. Operation, cutting oil and pressurized air supplied to ring placed around workpiece. Air forces oil through small holes and agitates oil as it flows over workpiece. High flow rate and agitation dislodge and remove debris. Electrical discharge removes material from workpiece faster.

  5. Sector ring accelerator ''RESATRON''

    International Nuclear Information System (INIS)

    Schwabe, E.

    1980-01-01

    Project of sector ring accelerator RESATRON is described. The curiosity of this accelerator is the second cycle of acceleration of the beam after stripping it on the foil. In such an accelerator heavy ions with a different ratio Z to A can be accelerated. (S.B.)

  6. Ring chromosome 13

    DEFF Research Database (Denmark)

    Brandt, C A; Hertz, Jens Michael; Petersen, M B

    1992-01-01

    A stillborn male child with anencephaly and multiple malformations was found to have the karyotype 46,XY,r(13) (p11q21.1). The breakpoint at 13q21.1, determined by high resolution banding, is the most proximal breakpoint ever reported in patients with ring chromosome 13. In situ hybridisation...

  7. SXLS storage ring design

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    X-ray lithography has emerged as a strong candidate to meet the demands of ever finer linewidths on integrated circuits, particularly for linewidths less than .25 microns. Proximity printing X-ray lithography makes use of soft X-rays to shadow print an image of a mask onto a semiconductor wafer to produce integrated circuits. To generate the required X-rays in sufficient quantities to make commercial production viable, electron storage rings have been proposed as the soft X-ray sources. Existing storage rings have been used to do the initial development work and the success of these efforts has led the lithographers to request that new rings be constructed that are dedicated to X-ray lithography. As a result of a series of workshops held at BNL [10.3] which were attended by both semiconductor and accelerator scientists, the following set of zeroth order specifications' on the light and electron beam of a storage ring for X-ray lithography were developed: critical wavelength of light: λ c = 6 to 10 angstroms, white light power: P = 0.25 to 2.5 watts/mrad, horizontal collection angle per port: θ = 10 to 50 mrad, electron beam sizes: σ x ∼ σ y y ' < 1 mrad

  8. Ring magnetron ionizer

    International Nuclear Information System (INIS)

    Alessi, J.G.

    1986-01-01

    A ring magnetron D - charge exchange ionizer has been built and tested. An H - current of 500 μA was extracted with an estimated H 0 density in the ionizer of 10 12 cm -3 . This exceeds the performance of ionizers presently in use on polarized H - sources. The ionizer will soon be tested with a polarized atomic beam

  9. Algebras, rings and modules

    CERN Document Server

    Hazewinkel, Michiel; Kirichenko, V V

    Provides both the classical aspects of the theory of groups and their representations as well as a general introduction to the modern theory of representations, including the representations of quivers and finite partially ordered sets. This volume provides the theory of semiprime Noetherian semiperfect and semidistributive rings.

  10. Lattices for antiproton rings

    International Nuclear Information System (INIS)

    Autin, B.

    1984-01-01

    After a description of the constraints imposed by the cooling of Antiprotons on the lattice of the rings, the reasons which motivate the shape and the structure of these machines are surveyed. Linear and non-linear beam optics properties are treated with a special amplification to the Antiproton Accumulator. (orig.)

  11. Propellers in Saturn's rings

    Science.gov (United States)

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

    2013-12-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B ring. The gap moves at Kepler speed appropriate for its radial location. Radial offsets of the gap locations in UVIS occultations are consistent with an asymmetric propeller shape. The asymmetry of the observed shape is most likely a consequence of the strong surface mass density gradient, as the feature is located at an edge between

  12. Compact radio sources

    International Nuclear Information System (INIS)

    Altschuler, D.R.

    1975-01-01

    Eighty-seven compact radio sources were monitored between 1971 and 1974 with the National Radio Astronomy Observatory interferometer. Both flux density and polarization were measured at intervals of about one month at wavelengths of 3.7 and 11.1 cms. Forty-four sources showed definite variability in their total and/or polarized flux density. The variations in polarization were of a shorter time scale than the corresponding flux density variations. Some of the qualitative features of an expanding source model were observed. The data suggest that some form of injection of relativistic electrons is taking place. The absence of significant depolarization in the variable sources indicates that only a small fraction of the mass of the radio outburst is in the form of non-relativistic plasma. Some of the objects observed belong to the BL-Lacertal class. It is shown that this class is very inhomogeneous in its radio properties. For the violently variable BL-Lacertal type objects the spectrum, flux variations and polarization data strongly suggest that these are very young objects

  13. Compact Dexterous Robotic Hand

    Science.gov (United States)

    Lovchik, Christopher Scott (Inventor); Diftler, Myron A. (Inventor)

    2001-01-01

    A compact robotic hand includes a palm housing, a wrist section, and a forearm section. The palm housing supports a plurality of fingers and one or more movable palm members that cooperate with the fingers to grasp and/or release an object. Each flexible finger comprises a plurality of hingedly connected segments, including a proximal segment pivotally connected to the palm housing. The proximal finger segment includes at least one groove defining first and second cam surfaces for engagement with a cable. A plurality of lead screw assemblies each carried by the palm housing are supplied with power from a flexible shaft rotated by an actuator and output linear motion to a cable move a finger. The cable is secured within a respective groove and enables each finger to move between an opened and closed position. A decoupling assembly pivotally connected to a proximal finger segment enables a cable connected thereto to control movement of an intermediate and distal finger segment independent of movement of the proximal finger segment. The dexterous robotic hand closely resembles the function of a human hand yet is light weight and capable of grasping both heavy and light objects with a high degree of precision.

  14. Compact stellarator coils

    International Nuclear Information System (INIS)

    Pomphrey, N.; Berry, L.A.; Boozer, A.H.

    2001-01-01

    Experimental devices to study the physics of high-beta (β>∼4%), low aspect ratio (A<∼4.5) stellarator plasmas require coils that will produce plasmas satisfying a set of physics goals, provide experimental flexibility, and be practical to construct. In the course of designing a flexible coil set for the National Compact Stellarator Experiment, we have made several innovations that may be useful in future stellarator design efforts. These include: the use of Singular Value Decomposition methods for obtaining families of smooth current potentials on distant coil winding surfaces from which low current density solutions may be identified; the use of a Control Matrix Method for identifying which few of the many detailed elements of the stellarator boundary must be targeted if a coil set is to provide fields to control the essential physics of the plasma; the use of Genetic Algorithms for choosing an optimal set of discrete coils from a continuum of potential contours; the evaluation of alternate coil topologies for balancing the tradeoff between physics objective and engineering constraints; the development of a new coil optimization code for designing modular coils, and the identification of a 'natural' basis for describing current sheet distributions. (author)

  15. Compact neutron generator

    Science.gov (United States)

    Leung, Ka-Ngo; Lou, Tak Pui

    2005-03-22

    A compact neutron generator has at its outer circumference a toroidal shaped plasma chamber in which a tritium (or other) plasma is generated. A RF antenna is wrapped around the plasma chamber. A plurality of tritium ion beamlets are extracted through spaced extraction apertures of a plasma electrode on the inner surface of the toroidal plasma chamber and directed inwardly toward the center of neutron generator. The beamlets pass through spaced acceleration and focusing electrodes to a neutron generating target at the center of neutron generator. The target is typically made of titanium tubing. Water is flowed through the tubing for cooling. The beam can be pulsed rapidly to achieve ultrashort neutron bursts. The target may be moved rapidly up and down so that the average power deposited on the surface of the target may be kept at a reasonable level. The neutron generator can produce fast neutrons from a T-T reaction which can be used for luggage and cargo interrogation applications. A luggage or cargo inspection system has a pulsed T-T neutron generator or source at the center, surrounded by associated gamma detectors and other components for identifying explosives or other contraband.

  16. Compact tokamak reactors

    International Nuclear Information System (INIS)

    Wootton, A.J.; Wiley, J.C.; Edmonds, P.H.; Ross, D.W.

    1997-01-01

    The possible use of tokamaks for thermonuclear power plants is discussed, in particular tokamaks with low aspect ratio and copper toroidal field coils. Three approaches are presented. First, the existing literature is reviewed and summarized. Second, using simple analytic estimates, the size of the smallest tokamak to produce an ignited plasma is derived. This steady state energy balance analysis is then extended to determine the smallest tokamaks power plant, by including the power required to drive the toroidal field and by considering two extremes of plasma current drive efficiency. Third, the analytic results are augmented by a numerical calculation that permits arbitrary plasma current drive efficiency and different confinement scaling relationships. Throughout, the importance of various restrictions is emphasized, in particular plasma current drive efficiency, plasma confinement, plasma safety factor, plasma elongation, plasma beta, neutron wall loading, blanket availability and recirculation of electric power. The latest published reactor studies show little advantage in using low aspect ratios to obtain a more compact device (and a low cost of electricity) unless either remarkably high efficiency plasma current drive and low safety factor are combined, or unless confinement (the H factor), the permissible elongation and the permissible neutron wall loading increase as the aspect ratio is reduced. These results are reproduced with the analytic model. (author). 22 refs, 3 figs

  17. Geodesic detection of Agulhas rings

    Science.gov (United States)

    Beron-Vera, F. J.; Wang, Y.; Olascoaga, M. J.; Goni, G. J.; Haller, G.

    2012-12-01

    Mesoscale oceanic eddies are routinely detected from instantaneous velocities. While simple to implement, this Eulerian approach gives frame-dependent results and often hides true material transport by eddies. Building on the recent geodesic theory of transport barriers, we develop an objective (i.e., frame-independent) method for accurately locating coherent Lagrangian eddies. These eddies act as compact water bodies, with boundaries showing no leakage or filamentation over long periods of time. Applying the algorithm to altimetry-derived velocities in the South Atlantic, we detect, for the first time, Agulhas rings that preserve their material coherence for several months, while eddy candidates yielded by other approaches tend to disperse or leak within weeks. These findings suggest that current Eulerian estimates of the Agulhas leakage need significant revision.Temporal evolution of fluid patches identified as eddies by different methods. First column: eddies extracted using geodesic eddy identification [1,2]. Second column: eddies identified from sea surface height (SSH) using the methodology of Chelton et al. [2] with U/c > 1. Third column: eddies identified as elliptic regions by the Okubo-Weiss (OW) criterion [e.g., 3]. Fourth column: eddies identified as mesoelliptic (ME) regions by Mezic et al.'s [4] criterion. References: [1] Beron-Vera et al. (2012). Geodesic eddy detection suggests reassessment of Agulhas leakage. Proc. Nat. Acad. Sci. USA, submitted. [2] Haller & Beron-Vera (2012). Geodesic theory of transport barriers in two-dimensional flows. Physica D, in press. [2] Chelton et al. (2011). Prog. Oceanog. 91, 167. [3] Chelton et al. (2007). Geophys. Res. Lett. 34, L5606. [4] Mezic et al. (2010). Science 330, 486.

  18. 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

  19. Inorganic glass ceramic slip rings

    Science.gov (United States)

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  20. 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.

  1. Coral Sr-U Thermometry

    Science.gov (United States)

    DeCarlo, T. M.; Gaetani, G. A.; Cohen, A. L.; Foster, G. L.; Alpert, A.; Stewart, J.

    2016-12-01

    Coral skeletons archive the past two millennia of climate variability in the oceans with unrivaled temporal resolution. However, extracting accurate temperature information from coral skeletons is confounded by "vital effects", which often override the temperature dependence of geochemical proxies. Here, we present a new approach to coral paleothermometry based on results of abiogenic precipitation experiments interpreted within a framework provided by a quantitative model of the coral biomineralization process. We conducted laboratory experiments to test the temperature and carbonate chemistry controls on abiogenic partitioning of Sr/Ca and U/Ca between aragonite and seawater, and we modeled the sensitivity of skeletal composition to processes occurring at the site of calcification. The model predicts that temperature can be accurately reconstructed from coral skeleton by combining Sr/Ca and U/Ca ratios into a new proxy, Sr-U. We tested the model predictions with measured Sr/Ca and U/Ca ratios of fourteen Porites sp. corals collected from the tropical Pacific Ocean and the Red Sea, with a subset also analyzed using the boron isotope (δ11B) pH proxy. Observed relationships among Sr/Ca, U/Ca, and δ11B agree with model predictions, indicating that the model accounts for the key features of the coral biomineralization process. We calibrated Sr-U to instrumental temperature records and found that it captures 93% of mean annual variability (26-30 °C) and predicts temperature within 0.5 °C (1 σ). Conversely, Sr/Ca alone has an error of prediction of 1 °C and often diverges from observed temperature by 3 °C or more. Many of the problems afflicting Sr/Ca - including offsets among neighboring corals and decouplings from temperature during coral stress events - are reconciled by Sr-U. By accounting for the influence of the coral biomineralization process, the Sr-U thermometer may offer significantly improved reliability for reconstructing ocean temperatures from coral

  2. Advanced Construction of Compact Containment BWR

    International Nuclear Information System (INIS)

    Takahashi, M.; Maruyama, T.; Mori, H.; Hoshino, K.; Hijioka, Y.; Heki, H.; Nakamaru, M.; Hoshi, T.

    2006-01-01

    The reactor concept considered in this paper has a mid/small power output, a compact containment and a simplified BWR configuration with comprehensive safety features. Compact Containment BWR (CCR) is being developed with matured BWR technologies together with innovative systems/components, will provide attractiveness for the energy market in the world due to its flexibility in energy demands as well as in site conditions, its high potential in reducing investment risk and its safety feature facilitating public acceptance. The flexibility is achieved by CCR's mid/small power output of 400 MWe class and capability of long operating cycle (refueling intervals). The high investment potential is expected from CCR's simplification/innovation in design such as natural circulation core cooling with the bottom located short core, top mounted upper entry control rod drives (CRDs) with ring-type dryers and simplified safety system with high pressure resistible primary containment vessel (PCV) concept. The natural circulation core eliminates recirculation pumps as well as needs for maintenance of such pumps. The top mounted upper entry CRDs enable the bottom located short core in RPV. The safety feature mainly consists of large water inventory above the core without large penetration below the top of the core, passive cooling system by isolation condenser (IC), high pressure resistible PCV and in-vessel retention (IVR) capability. The large inventory increases the system response time in case of design base accidents including loss of coolant accidents. The IC suppresses PCV pressure by steam condensation without any AC power. Cooling the molten core inside the RPV if the core should be damaged by loss of core coolability could attain the IVR. CCR's specific self-standing steel high pressure resistible PCV is designed to contain minimum piping and valves inside with reactor pressure vessel (RPV), only 13 m in diameter and 24 m in height. This compact PCV makes it possible to

  3. 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.

  4. Impedance effects in the CLIC damping rings

    CERN Document Server

    Koukovini-Platia, E; Mounet, N; Rumolo, G; Salvant, B

    2011-01-01

    Due to the unprecedented brilliance of the beams, the performance of the Compact Linear Collider (CLIC) damping rings (DR) is affected by collective effects. Single bunch instability thresholds based on a broad-band resonator model and the associated coherent tune shifts have been evaluated with the HEADTAIL code. Simulations performed for positive and negative values of chromaticity showed that higher order bunch modes can be potentially dangerous for the beam stability. This study also includes the effects of high frequency resistive wall impedance due to different coatings applied on the chambers of the wigglers for e-cloud mitigation and/or ultra-low vacuum pressure. The impact of the resistive wall wake fields on the transverse impedance budget is finally discussed.

  5. Compact Holographic Data Storage

    Science.gov (United States)

    Chao, T. H.; Reyes, G. F.; Zhou, H.

    2001-01-01

    NASA's future missions would require massive high-speed onboard data storage capability to Space Science missions. For Space Science, such as the Europa Lander mission, the onboard data storage requirements would be focused on maximizing the spacecraft's ability to survive fault conditions (i.e., no loss in stored science data when spacecraft enters the 'safe mode') and autonomously recover from them during NASA's long-life and deep space missions. This would require the development of non-volatile memory. In order to survive in the stringent environment during space exploration missions, onboard memory requirements would also include: (1) survive a high radiation environment (1 Mrad), (2) operate effectively and efficiently for a very long time (10 years), and (3) sustain at least a billion write cycles. Therefore, memory technologies requirements of NASA's Earth Science and Space Science missions are large capacity, non-volatility, high-transfer rate, high radiation resistance, high storage density, and high power efficiency. JPL, under current sponsorship from NASA Space Science and Earth Science Programs, is developing a high-density, nonvolatile and rad-hard Compact Holographic Data Storage (CHDS) system to enable large-capacity, high-speed, low power consumption, and read/write of data in a space environment. The entire read/write operation will be controlled with electrooptic mechanism without any moving parts. This CHDS will consist of laser diodes, photorefractive crystal, spatial light modulator, photodetector array, and I/O electronic interface. In operation, pages of information would be recorded and retrieved with random access and high-speed. The nonvolatile, rad-hard characteristics of the holographic memory will provide a revolutionary memory technology meeting the high radiation challenge facing the Europa Lander mission. Additional information is contained in the original extended abstract.

  6. Compact instantaneous water heater

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-07-01

    This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)

  7. Design of low energy ring(s)

    CERN Document Server

    Lachaize, Antoine

    During the last two years, several upgrades of the initial baseline scenario were studied with the aim of increasing the average intensity of ion beams in the accelerator chain of the Beta Beam complex. This is the reason why the Rapid Cycling Synchrotron (RCS) specifications were reconsidered many times [1], [2], [3].General considerations on the optical design were presented at the Beta Beam Task Meetings held at CERN and at Saclay in 2005 [4]. More detailed beam optics studies were performed during the next months. Lattices, RF system parameters, multi-turn injection scheme, fast extraction, closed orbit correction and chromaticity correction systems were proposed for different versions of the RCS [5], [6], [7].Finally, the RCS specifications have stabilized in November 2006 after the fourth Beta Beam Task Meeting when it was decided to fix the maximum magnetic rigidity of ion beams to 14.47 T.m (3.5 GeV equivalent proton energy) and to adopt a ring physical radius of 40 m in order to facilitate injectio...

  8. 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...

  9. 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.

  10. Imaging phase slip dynamics in micron-size superconducting rings

    Science.gov (United States)

    Polshyn, Hryhoriy; Naibert, Tyler R.; Budakian, Raffi

    2018-05-01

    We present a scanning probe technique for measuring the dynamics of individual fluxoid transitions in multiply connected superconducting structures. In these measurements, a small magnetic particle attached to the tip of a silicon cantilever is scanned over a micron-size superconducting ring fabricated from a thin aluminum film. We find that near the superconducting transition temperature of the aluminum, the dissipation and frequency of the cantilever changes significantly at particular locations where the tip-induced magnetic flux penetrating the ring causes the two lowest-energy fluxoid states to become nearly degenerate. In this regime, we show that changes in the cantilever frequency and dissipation are well-described by a stochastic resonance (SR) process, wherein small oscillations of the cantilever in the presence of thermally activated phase slips (TAPS) in the ring give rise to a dynamical force that modifies the mechanical properties of the cantilever. Using the SR model, we calculate the average fluctuation rate of the TAPS as a function of temperature over a 32-dB range in frequency, and we compare it to the Langer-Ambegaokar-McCumber-Halperin theory for TAPS in one-dimensional superconducting structures.

  11. What Is Business's Social Compact?

    Science.gov (United States)

    Avishai, Bernard

    1994-01-01

    Under the "new" social compact, businesses must focus on continuous learning and thus have both an obligation to support teaching and an opportunity to profit from it. Learning organizations must also be teaching organizations. (SK)

  12. Collapse settlement in compacted soils

    CSIR Research Space (South Africa)

    Booth, AR

    1977-01-01

    Full Text Available Research into collapse settlement in compacted soils is described, with special reference to recent cases in Southern Africa where collapse settlement occurred in road embankments following wetting of the soil. The laboratory work described...

  13. Compact silicon photonic resonance-sssisted variable optical attenuator.

    Science.gov (United States)

    Wang, Xiaoxi; Aguinaldo, Ryan; Lentine, Anthony; DeRose, Christopher; Starbuck, Andrew L; Trotter, Douglas; Pomerene, Andrew; Mookherjea, Shayan

    2016-11-28

    A two-part silicon photonic variable optical attenuator is demonstrated in a compact footprint which can provide a high extinction ratio at wavelengths between 1520 nm and 1620 nm. The device was made by following the conventional p-i-n waveguide section by a high-extinction-ratio second-order microring filter section. The rings provide additional on-off contrast by utilizing a thermal resonance shift, which harvested the heat dissipated by current injection in the p-i-n junction. We derive and discuss a simple thermal-resistance model in explanation of these effects.

  14. Ring Confidential Transactions

    Directory of Open Access Journals (Sweden)

    Shen Noether

    2016-12-01

    Full Text Available This article introduces a method of hiding transaction amounts in the strongly decentralized anonymous cryptocurrency Monero. Similar to Bitcoin, Monero is a cryptocurrency which is distributed through a proof-of-work “mining” process having no central party or trusted setup. The original Monero protocol was based on CryptoNote, which uses ring signatures and one-time keys to hide the destination and origin of transactions. Recently the technique of using a commitment scheme to hide the amount of a transaction has been discussed and implemented by Bitcoin Core developer Gregory Maxwell. In this article, a new type of ring signature, A Multilayered Linkable Spontaneous Anonymous Group signature is described which allows one to include a Pedersen Commitment in a ring signature. This construction results in a digital currency with hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation. The author would like to note that early drafts of this were publicized in the Monero Community and on the #bitcoin-wizards IRC channel. Blockchain hashed drafts are available showing that this work was started in Summer 2015, and completed in early October 2015. An eprint is also available at http://eprint.iacr.org/2015/1098.

  15. Compact torus accelerator as a driver for ICF

    International Nuclear Information System (INIS)

    Tobin, M.T.; Meier, W.R.; Morse, E.C.

    1986-01-01

    The authors have carried out further investigations of the technical issues associated with using a compact torus (CT) accelerator as a driver for inertial confinement fusion (ICF). In a CT accelerator, a magnetically confined, torus-shaped plasma is compressed, accelerated, and focused by two concentric electrodes. After its initial formation, the torus shape is maintained for lifetimes exceeding 1 ms by inherent poloidal and toroidal currents. Hartman suggests acceleration and focusing of such a plasma ring will not cause dissolution within certain constraints. In this study, we evaluated a point design based on an available capacitor bank energy of 9.2 MJ. This accelerator, which was modeled by a zero-dimensional code, produces a xenon plasma ring with a 0.73-cm radius, a velocity of 4.14 x 10 9 cm/s, and a mass of 4.42 μg. The energy of the plasma ring as it leaves the accelerator is 3.8 MJ, or 41% of the capacitor bank energy. Our studies confirm the feasibility of producing a plasma ring with the characteristics required to induce fusion in an ICF target with a gain greater than 50. The low cost and high efficiency of the CT accelerator are particularly attractive. Uncertainties concerning propagation, accelerator lifetime, and power supply must be resolved to establish the viability of the accelerator as an ICF driver

  16. Applications of UV-storage ring free electron lasers: the case of super-ACO

    CERN Document Server

    Nahon, L; Couprie, Marie Emmanuelle; Merola, F; Dumas, P; Marsi, M; Taleb-Ibrahimi, A; Nutarelli, D; Roux, R; Billardon, M

    1999-01-01

    The potential of UV-storage ring free electron lasers (SRFELs) for the performance of original application experiments is shown with a special emphasis concerning their combination with the naturally synchronized synchrotron radiation (SR). The first two-color FEL+SR experiment, performed in surface science at Super-ACO is reported. The experimental parameters found to be the most important as gathered from the acquired experience, are underlined and discussed. Finally, future prospects for the scientific program of the Super-ACO FEL are presented with two-color experiments combining the FEL with SR undulator-based XUV and VUV beamlines as well as with a SR white light bending magnet beamline emiting in the IR-UV (20 mu m-0.25 mu m).

  17. 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....

  18. Electron density enhancement in a quasi isochronous storage ring

    International Nuclear Information System (INIS)

    Pellegrini, C.; Robin, D.

    1991-01-01

    The six dimensional phase-space density of an electron beam in a storage ring is determined by the emission of synchrotron radiation, and by the transverse and longitudinal focusing forces determining the particle trajectories. In the simplest case of uncoupled horizontal, vertical and longitudinal motion, the phase space volume occupied by the beam can be characterized by the product of its three projections on the single degree of freedom planes, the horizontal, vertical, and longitudinal emittances. To minimize the beam phase space volume the authors can minimize the transverse and longitudinal emittances. In the case of transverse emittances this problem is very important for synchrotron radiation sources, and has been studied by several authors. A method to minimize the longitudinal emittance, and produce electron bunches with a short pulse length, small energy spread and large peak current has been proposed and discussed recently by C. Pellegrini and D. Robin. This method uses a ring in which the revolution period is weakly dependent on the particle energy, Quasi Isochronous Ring (QIR), in other words a ring with a momentum compaction nearly zero. In this paper they will extend the previous analysis of the conditions for stable single particle motion in such a ring, and give simple criteria for the estimate of the energy spread and phase acceptance of a QIR

  19. Conceptual design of a moving-ring reactor

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

    1983-01-01

    A design of a prototype Moving-Ring Reactor has been completed. 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 one third 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. The first wall and tritium breeding blanket designs make credible use of helium cooling, SiC and Li 2 O to minimize structural radioactivity. ''Hands-on'' maintenance is possible on all reactor components outside the blanket. The first wall and blanket are designed to shut the reactor down passively in the event of a loss-of-coolant or loss-of-flow accident. Helium removes heat from the first wall, blanket and shield, and is used in a closed-cycle gas turbine to produce electricity. Energy residing in the plasma ring at the end of the burn is recovered via magnetic expansion. Electrostatic direct conversion is not used in this design. The reactor produces a constant net power of 99 MW(e). (author)

  20. Synthetic clay excels in 90Sr removal

    International Nuclear Information System (INIS)

    Komarneni, Sridhar; Kodama, Tatsuya; Paulus, William J.; Carlson, C.

    2000-01-01

    Tests with actual ground water from Hanford site, and fundamental studies of 2Na + →Sr 2+ exchange equilibria revealed that a synthetic clay is extremely selective for 90 Sr with a high capacity for uptake. Comparative studies with existing Sr selective ion exchangers clearly revealed that the present synthetic clay exhibited the best performance for 90 Sr removal from actual ground water collected from three different locations at Hanford. This novel Sr ion sieve is expected to be useful for the decontamination of the environment after accidental release and contamination with 90 Sr. (c) 2000 Materials Research Society

  1. Linear all-optical signal processing using silicon micro-ring resonators

    DEFF Research Database (Denmark)

    Ding, Yunhong; Ou, Haiyan; Xu, Jing

    2016-01-01

    Silicon micro-ring resonators (MRRs) are compact and versatile devices whose periodic frequency response can be exploited for a wide range of applications. In this paper, we review our recent work on linear all-optical signal processing applications using silicon MRRs as passive filters. We focus...

  2. A FODO racetrack ring for nuSTORM: design and optimization

    Energy Technology Data Exchange (ETDEWEB)

    Liu, A.; Bross, A.; Neuffer, D.

    2017-07-01

    The goal of nuSTORM is to provide well-defined neutrino beams for precise measurements of neutrino cross-sections and oscillations. The nuSTORM decay ring is a compact racetrack storage ring with a circumference of ~ 480 m that incorporates large aperture (60 cm diameter) magnets. There are many challenges in the design. In order to incorporate the Orbit Combination section (OCS), used for injecting the pion beam into the ring, a dispersion suppressor is needed adjacent to the OCS . Concurrently, in order to maximize the number of useful muon decays, strong bending dipoles are needed in the arcs to minimize the arc length. These dipoles create strong chromatic effects, which need to be corrected by nonlinear sextupole elements in the ring. In this paper, a FODO racetrack ring design and its optimization using sextupolar fields via both a Genetic Algorithm (GA) and a Simulated Annealing (SA) algorithm will be discussed.

  3. 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…

  4. Compact Intracloud Discharges

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David A. [Univ. of Colorado, Boulder, CO (United States)

    1998-11-01

    In November of 1993, mysterious signals recorded by a satellite-borne broadband VHF radio science experiment called Blackboard led to a completely unexpected discovery. Prior to launch of the ALEXIS satellite, it was thought that its secondary payload, Blackboard, would most often detect the radio emissions from lightning when its receiver was not overwhelmed by noise from narrowband communication carriers. Instead, the vast majority of events that triggered the instrument were isolated pairs of pulses that were one hundred times more energetic than normal thunderstorm electrical emissions. The events, which came to be known as TIPPs (for transionospheric pulse pairs), presented a true mystery to the geophysics community. At the time, it was not even known whether the events had natural or anthropogenic origins. After two and one half years of research into the unique signals, two ground-based receiver arrays in New Mexico first began to detect and record thunderstorm radio emissions that were consistent with the Blackboard observations. On two occasions, the ground-based systems and Blackboard even recorded emissions that were produced by the same exact events. From the ground based observations, it has been determined that TIPP events areproduced by brief, singular, isolated, intracloud electrical discharges that occur in intense regions of thunderstorms. These discharges have been dubbed CIDS, an acronym for compact intracloud discharges. During the summer of 1996, ground-based receiver arrays were used to record the electric field change signals and broadband HF emissions from hundreds of CIDS. Event timing that was accurate to within a few microseconds made possible the determination of source locations using methods of differential time of arrival. Ionospheric reflections of signals were recorded in addition to groundwave/line-of-sight signals and were used to determine accurate altitudes for the discharges. Twenty-four CIDS were recorded from three

  5. Internal bremsstrahlung from 89Sr and 90Sr

    International Nuclear Information System (INIS)

    Sayibaba, T.; Narasimha Murity, K.; Rao, C.R.; Satyaprakash; Gubbi, G.K.

    1987-01-01

    The internal bremsstrahlung (IB) spectra emitted in the beta-decays of 89 Sr and 90 Sr were measured with a HPGe detector and a multichannel analyser along with a standard geometrical set-up. Sufficient care has been taken to avoid spurious effects. After making all the necessary corrections, the experimental results were compared with the corresponding theoretical distributions due to Knipp and Uhlenbeck and Bloch (KUB), Lewis and Ford, Nilsson, and also due to Ford and Martin (detour theory). The total IB yields of intensity and energy from each of the isotopes in the investigated energy regions are also determined and compared with the corresponding theoretical values. The present results of IB from 89 Sr are satisfactorily accounted for by the KUB theory. In the case of 90 Sr the experimental results of IB coincide with the Coulomb-corrected theoretical distibution due to Nilsson in the energy range from 60 keV to 110 keV and Beyond 110 keV, they are found to be in excess over Nilsson's theory as well as the detour theory due to Ford and Martin up to the maximum photon energy studied, namely 350 keV

  6. SOR-ring failure

    International Nuclear Information System (INIS)

    Kitamura, Hideo

    1981-01-01

    It was in the autumn of 1976 that the SOR-ring (synchrotron radiation storage ring) has commenced the regular operation. Since then, the period when the operation was interrupted due to the failures of SOR-ring itself is in total about 8 weeks. Failures and accidents have occurred most in the vacuum system. Those failure experiences are described on the vacuum, electromagnet, radio-frequency acceleration and beam transport systems with their interrupted periods. The eleven failures in the vacuum system have been reported, such as bellows breakage in a heating-evacuating period, leakage from the bellows of straight-through valves (made in U.S.A. and Japan), and leakage from the joint flange of the vacuum system. The longest interruption was 5 weeks due to the failure of a domestically manufactured straight-through valve. The failures of the electromagnet system involve the breakage in a cooling water system, short circuit of a winding in the Q magnet power transformer, blow of a fuse protecting the deflection magnet power source by the current less than the rating, and others. The failures of the RF acceleration system include the breakage of an output electronic tube the breakage of a cavity ceramic, RF voltage fluctuation due to the contact deterioration at a cavity electrode, and the failure of grid bias power source. It is necessary to select the highly reliable components for the vacuum system because the vacuum system failures require longer time for recovery, and very likely to induce secondary and tertiary failures. (Wakatsuki, Y.)

  7. Proton storage rings

    International Nuclear Information System (INIS)

    Rau, R.R.

    1978-04-01

    A discussion is given of proton storage ring beam dynamic characteristics. Topics considered include: (1) beam energy; (2) beam luminosity; (3) limits on beam current; (4) beam site; (5) crossing angle; (6) beam--beam interaction; (7) longitudinal instability; (8) effects of scattering processes; (9) beam production; and (10) high magnetic fields. Much of the discussion is related to the design parameters of ISABELLE, a 400 x 400 GeV proton---proton intersecting storage accelerator to be built at Brookhaven National Laboratory

  8. Ring-constrained Join

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Karras, Panagiotis; Mamoulis, Nikos

    2008-01-01

    . This new operation has important applications in decision support, e.g., placing recycling stations at fair locations between restaurants and residential complexes. Clearly, RCJ is defined based on a geometric constraint but not on distances between points. Thus, our operation is fundamentally different......We introduce a novel spatial join operator, the ring-constrained join (RCJ). Given two sets P and Q of spatial points, the result of RCJ consists of pairs (p, q) (where p ε P, q ε Q) satisfying an intuitive geometric constraint: the smallest circle enclosing p and q contains no other points in P, Q...

  9. Femtoslicing in Storage Rings

    CERN Document Server

    Khan, Shaukat

    2005-01-01

    The generation of ultrashort synchrotron radiation pulses by laser-induced energy modulation of electrons and their subsequent transverse displacement, now dubbed "femtoslicing," was demonstrated at the Advanced Light Source in Berkeley. More recently, a femtoslicing user facility was commissioned at the BESSY storage ring in Berlin, and another project is in progress at the Swiss Light Source. The paper reviews the principle of femtoslicing, its merits and shortcomings, as well as the variations of its technical implementation. Various diagnostics techniques to detect successful laser-electron interaction are discussed and experimental results are presented.

  10. 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.

  11. 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.

  12. Summary of Self-compacting Concrete Workability

    OpenAIRE

    GUO Gui-xiang; Duan Hong-jun

    2015-01-01

    On the basis of a large number of domestic and foreign literature, situation and development of self-compacting concrete is introduced. Summary of the compacting theory of self-compacting concrete. And some of the factors affecting the workability of self-compacting concrete were discussed and summarized to a certain extent. Aims to further promote the application and research of self-compacting concrete

  13. Clustering of near clusters versus cluster compactness

    International Nuclear Information System (INIS)

    Yu Gao; Yipeng Jing

    1989-01-01

    The clustering properties of near Zwicky clusters are studied by using the two-point angular correlation function. The angular correlation functions for compact and medium compact clusters, for open clusters, and for all near Zwicky clusters are estimated. The results show much stronger clustering for compact and medium compact clusters than for open clusters, and that open clusters have nearly the same clustering strength as galaxies. A detailed study of the compactness-dependence of correlation function strength is worth investigating. (author)

  14. Compact magnetic confinement fusion: Spherical torus and compact torus

    Directory of Open Access Journals (Sweden)

    Zhe Gao

    2016-05-01

    Full Text Available The spherical torus (ST and compact torus (CT are two kinds of alternative magnetic confinement fusion concepts with compact geometry. The ST is actually a sub-category of tokamak with a low aspect ratio; while the CT is a toroidal magnetic configuration with a simply-connected geometry including spheromak and field reversed pinch. The ST and CT have potential advantages for ultimate fusion reactor; while at present they can also provide unique fusion science and technology contributions for mainstream fusion research. However, some critical scientific and technology issues should be extensively investigated.

  15. 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.

  16. Cerenkov Counter for In-Situ Groundwater Monitoring of 90Sr

    Directory of Open Access Journals (Sweden)

    Lindsay C. Todd

    2005-02-01

    Full Text Available Groundwater contamination from 90Sr is an environmental challenge posed topresent and former nuclear weapons related sites. Traditional methods of extractinggroundwater samples and performing laboratory analyses are expensive, time-consumingand induce significant disposal challenges. The authors present here a prototype countercapable of measuring 90Sr groundwater concentrations in-situ at or below the drinking waterlimit of 8 pCi/liter. The 90Y daughter of 90Sr produces high-energy electrons, which cancreate Cerenkov light. Photomultiplier tubes convert the Cerenkov light into an electronicpulse, which then undergoes signal processing with standard electronics. Strontium-90concentrations near the drinking water limit can be measured in a matter of hours if it is insecular equilibrium with the 90Y daughter. The prototype counter is compact, can bedeployed in an American Standard 6-inch, well while operated by a single person, andtransmits the results to a central monitoring location.

  17. 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

  18. Westinghouse compact poloidal divertor reference design

    International Nuclear Information System (INIS)

    Yang, T.F.; Lee, A.Y.; Ruck, G.W.

    1977-08-01

    A feasible compact poloidal divertor system has been designed as an impurity control and vacuum vessel first-wall protection option for the TNS tokamak. The divertor coils are inside the TF coil array and vacuum vessel. The poloidal divertor is formed by a pair of coil sets with zero net current. Each set consists of a number of coils forming a dish-shaped washer-like ring. The magnetic flux in the space between the coil sets is compressed vertically to limit the height and to expand the horizontal width of the particle and energy burial chamber which is located in the gap between the coil sets. The intensity of the poloidal field is increased to make the pitch angle of the flux lines very large so that the diverted particles can be intercepted by a large number of panels oriented at a small angle with respect to the flux lines. They are carefully shaped and designed such that the entire surfaces are exposed to the incident particles and are not shadowed by each other. Large collecting surface areas can be obtained. Flowing liquid lithium film and solid metal panels have been considered as the particle collectors. The power density for the former is designed at 1 MW/m 2 and for the latter 0.5 MW/m 2 . The major mechanical, thermal, and vacuum problems have been evaluated in sufficient detail so that the advantages and difficulties are identified. A complete functional picture is presented

  19. Design of a 4.8-m ring for inverse Compton scattering x-ray source

    Directory of Open Access Journals (Sweden)

    H. S. Xu

    2014-07-01

    Full Text Available In this paper we present the design of a 50 MeV compact electron storage ring with 4.8-meter circumference for the Tsinghua Thomson scattering x-ray source. The ring consists of four dipole magnets with properly adjusted bending radii and edge angles for both horizontal and vertical focusing, and a pair of quadrupole magnets used to adjust the horizontal damping partition number. We find that the dynamic aperture of compact storage rings depends essentially on the intrinsic nonlinearity of the dipole magnets with small bending radius. Hamiltonian dynamics is found to agree well with results from numerical particle tracking. We develop a self-consistent method to estimate the equilibrium beam parameters in the presence of the intrabeam scattering, synchrotron radiation damping, quantum excitation, and residual gas scattering. We also optimize the rf parameters for achieving a maximum x-ray flux.

  20. NRL ion ring program

    International Nuclear Information System (INIS)

    Kapetanakos, C.A.; Golden, J.; Drobot, A.; Mahaffey, R.A.; Marsh, S.J.; Pasour, J.A.

    1977-01-01

    An experiment is under way to form a storng proton ring using the 200 ka, 1.2 MeV, 50 nsec hollow proton beam recently generated at NRL. The 5 m long magnetic field configuration consists of a magnetic cusp, a compressing magnetic field, a gate field and a magnetic mirror. The midplane value of the magnetic mirror is such that the major radius of the ring will be about 10 cm. The degree of field reversal that will be achieved with 5 x 10 16 protons per pulse from the existing beam depends upon the field reversal is possible with the 600 kA proton beam that would be generated from the low inductance coaxial triode coupled to the upgraded Gamble II generator. The propagation and trapping of an intense proton beam in the experimental magnetic field configuration is investigated numerically. The results show that the self magnetic has a very pronounced effect on the dynamics of the gyrating protons

  1. Flexible ring seal

    International Nuclear Information System (INIS)

    Abbes, Claude; Gournier, Andre; Rouaud, Christian; Villepoix, Raymond de.

    1976-01-01

    The invention concerns a flexible metal ring seal, able to ensure a perfect seal between two bearings due to the crushing and elastic deformation properties akin to similar properties in elastomers. Various designs of seal of this kind are already known, particularly a seal made of a core formed by a helical wire spring with close-wound turns and with high axial compression ratio, closed on itself and having the shape of an annulus. This wire ring is surrounded by at least one envelope having at rest the shape of a toroidal surface of which the generating circle does not close on itself. In a particular design mode, the seal in question can include, around the internal spring, two envelopes of which one in contact with the spring is composed of a low ductility elastic metal, such as mild steel or stainless steel and the other is, on the contrary, made of a malleable metal, such as copper or nickel. The first envelope evenly distributes the partial crushing of the spring, when the seal is tightened, on the second envelope which closely fits the two surfaces between which the seal operates. The stress-crushing curve characteristic of the seal comprises two separate parts, the first with a relatively sharp slope corresponds to the start of the seal compression phase, enabling at least some of these curves to reach the requisite seal threshold very quickly, then, beyond this, a second part, practically flat, where the stress is appreciably constant for a wide operating bracket [fr

  2. The Rb-Sr system

    International Nuclear Information System (INIS)

    Graham, I.J.

    1983-11-01

    This manual is intended to serve as a guide to the chemical procedures involved in Rb-Sr isotopic analysis as conducted at the Institute of Nuclear Sciences. Included are notes on the experimental developments made over the last 2.5 years, especially those involving rock dissolution and cation exchange chromatography

  3. 90Sr in animal bones

    International Nuclear Information System (INIS)

    Kostadinov, K.

    1994-01-01

    90 Sr content in deer from Finland and Bulgaria, as well as cows and domestic pigs from Bulgaria has been investigated. The results obtained support an evaluation of the radioactive contamination of the biosphere in Bulgaria after the Chernobyl accident. (author)

  4. 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

  5. The DARPA compact Superconducting X-Ray Lithography Source features

    International Nuclear Information System (INIS)

    Heese, R.; Kalsi, S.; Leung, E.

    1991-01-01

    Under DARPA sponsorship, a compact Superconducting X-Ray Lithography Source (SXLS) is being designed and built by the Brookhaven National Laboratory (BNL) with industry participation from Grumman Corporation and General Dynamics. This source is optimized for lithography work for sub-micron high density computer chips, and is about the size of a billiard table (1.5 m x 4.0 m). The machine has a racetrack configuration with two 180 degree bending magnets being designed and built by General Dynamics under a subcontract with Grumman Corporation. The machine will have 18 photon ports which would deliver light peaked at a wave length of 10 Angstroms. Grumman is commercializing the SXLS device and plans to book orders for delivery of industrialized SXLS (ISXLS) versions in 1995. This paper will describe the major features of this device. The commercial machine will be equipped with a fully automated user-friendly control systems, major features of which are already working on a compact warm dipole ring at BNL. This ring has normal dipole magnets with dimensions identical to the SXLS device, and has been successfully commissioned

  6. Upgrading of the Munich reactor with a compact core

    International Nuclear Information System (INIS)

    Boening, K.; Glaeser, W.; Meier, J.; Rau, G.; Roehrmoser, A.; Zhang, L.

    1985-01-01

    An extremely small reactor core has been proposed for the project of substantial modernization of the FRM research reactor at Munich. According to the present status this 'compact core' will be a cylinder with a diameter of about 20 cm and 70 cm high. The new high-density U 3 Si/Al dispersion fuel of about 45% enrichment is contained in 20 concentric fuel plate rings. The compact core is surrounded by a large heavy-water tank which will incorporate the user installations (beam tubes and irradiation channels). However, the primary cooling circuit will contain light water which is not only more economic but also essential for the performance of the small core. An important optimization potential to decrease easily the power density peaks in the core is to reduce further the enrichment in those fuel plate rings where the neutron flux is particularly high. Two-dimensional neutron transport calculations show that such a core, containing about 7.5 kg 235 U, should have an effective multiplication factor of about 1.22 and an unperturbed but realistic maximum thermal neutron flux in the heavy water tank of 7 to 8x10 14 cm -2 .s -1 at 20 MW reactor power. (author)

  7. Professional Windows Embedded Compact 7

    CERN Document Server

    Phung, Samuel; Joubert, Thierry; Hall, Mike

    2011-01-01

    Learn to program an array of customized devices and solutions As a compact, highly efficient, scalable operating system, Windows Embedded Compact 7 (WEC7) is one of the best options for developing a new generation of network-enabled, media-rich, and service-oriented devices. This in-depth resource takes you through the benefits and capabilities of WEC7 so that you can start using this performance development platform today. Divided into several major sections, the book begins with an introduction and then moves on to coverage of OS design, application development, advanced application developm

  8. Modeling of compact loop antennas

    International Nuclear Information System (INIS)

    Baity, F.W.

    1987-01-01

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively-tuned resonant double loop (RDL) antennas the model treats stub-tuned resonant double loop antennas. Calculations using the model have been compared with measurements on full-scale mockups of resonant double loop antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and for the Compact Ignition Tokamak

  9. Compact accelerator for medical therapy

    Science.gov (United States)

    Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

    2010-05-04

    A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

  10. Compact toroid refueling of reactors

    International Nuclear Information System (INIS)

    Gouge, M.J.; Hogan, J.T.; Milora, S.L.; Thomas, C.E.

    1988-04-01

    The feasibility of refueling fusion reactors and devices such as the International Thermonuclear Engineering Reactor (ITER) with high-velocity compact toroids is investigated. For reactors with reasonable limits on recirculating power, it is concluded that the concept is not economically feasible. For typical ITER designs, the compact toroid fueling requires about 15 MW of electrical power, with about 5 MW of thermal power deposited in the plasma. At these power levels, ideal ignition (Q = ∞) is not possible, even for short-pulse burns. The pulsed power requirements for this technology are substantial. 6 ref., 1 figs

  11. Co-compact Gabor Systems on Locally Compact Abelian Groups

    DEFF Research Database (Denmark)

    Jakobsen, Mads Sielemann; Lemvig, Jakob

    2016-01-01

    In this work we extend classical structure and duality results in Gabor analysis on the euclidean space to the setting of second countable locally compact abelian (LCA) groups. We formulate the concept of rationally oversampling of Gabor systems in an LCA group and prove corresponding characteriz...

  12. Isometric coactions of compact quantum groups on compact ...

    Indian Academy of Sciences (India)

    a compact quantum metric space in the framework of Rieffel, where the ... This problem can be formulated and studied in various settings. ... The spaces we are interested in this paper are metric spaces, both classical and quantum. ... He has given a definition for a quantum symmetry of a classical ...... by the construction of I.

  13. Electronic properties and surface reactivity of SrO-terminated SrTiO3 and SrO-terminated iron-doped SrTiO3.

    Science.gov (United States)

    Staykov, Aleksandar; Tellez, Helena; Druce, John; Wu, Ji; Ishihara, Tatsumi; Kilner, John

    2018-01-01

    Surface reactivity and near-surface electronic properties of SrO-terminated SrTiO 3 and iron doped SrTiO 3 were studied with first principle methods. We have investigated the density of states (DOS) of bulk SrTiO 3 and compared it to DOS of iron-doped SrTiO 3 with different oxidation states of iron corresponding to varying oxygen vacancy content within the bulk material. The obtained bulk DOS was compared to near-surface DOS, i.e. surface states, for both SrO-terminated surface of SrTiO 3 and iron-doped SrTiO 3 . Electron density plots and electron density distribution through the entire slab models were investigated in order to understand the origin of surface electrons that can participate in oxygen reduction reaction. Furthermore, we have compared oxygen reduction reactions at elevated temperatures for SrO surfaces with and without oxygen vacancies. Our calculations demonstrate that the conduction band, which is formed mainly by the d-states of Ti, and Fe-induced states within the band gap of SrTiO 3 , are accessible only on TiO 2 terminated SrTiO 3 surface while the SrO-terminated surface introduces a tunneling barrier for the electrons populating the conductance band. First principle molecular dynamics demonstrated that at elevated temperatures the surface oxygen vacancies are essential for the oxygen reduction reaction.

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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.

  20. ring 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....

  1. Detection of Sr-90 in bones using a photoluminescence imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Drissner, J [Inst. fuer Innovation und Transfer, Fachhochschule Ravensburg-Weingarten, Weingarten (Germany); Kaminski, S [Inst. fuer Innovation und Transfer, Fachhochschule Ravensburg-Weingarten, Weingarten (Germany); Koulikov, A O [A.N. Severtzov Inst. of Evolutionary Morphology and Ecology of Animals, Russian Academy of Sciences, Moscow (Russian Federation); Lindner, G [Inst. fuer Innovation und Transfer, Fachhochschule Ravensburg-Weingarten, Weingarten (Germany)

    1994-12-31

    Using a photoluminescence imaging system with BaFBr:Eu{sup 2+} imaging plates and digital image processing the distribution of {sup 90}Sr radionuclides incorporated from the Chernobyl fallout in bones of fish was measured, which were caught in Kiev reservoir in 1992. According to the rings of annual growth of the analyzed bones (kleitrum) the time sequence of incorporation could be reconstructed resulting in incorporation maxima in 1986 for most samples, but n some samples also maxima corresponding to subsequent years were observed. The system was calibrated with synthetical samples of similar thickness made from bone powder and homogeneously doped with {sup 90}Sr standard solutions. The amount of {sup 90}Sr radioactivity in the bone samples, which was determined quantitatively after about one day of exposition, was in the order of 0,1 Bq. (orig.)

  2. Compaction dynamics of crunchy granular material

    Directory of Open Access Journals (Sweden)

    Guillard François

    2017-01-01

    Full Text Available Compaction of brittle porous material leads to a wide variety of densification patterns. Static compaction bands occurs naturally in rocks or bones, and have important consequences in industry for the manufacturing of powder tablets or metallic foams for example. Recently, oscillatory compaction bands have been observed in brittle porous media like snow or cereals. We will discuss the great variety of densification patterns arising during the compaction of puffed rice, including erratic compaction at low velocity, one or several travelling compaction bands at medium velocity and homogeneous compaction at larger velocity. The conditions of existence of each pattern are studied thanks to a numerical spring lattice model undergoing breakage and is mapped to the phase diagram of the patterns based on dimensionless characteristic quantities. This also allows to rationalise the evolution of the compaction behaviour during a single test. Finally, the localisation of compaction bands is linked to the strain rate sensitivity of the material.

  3. Compaction dynamics of crunchy granular material

    Science.gov (United States)

    Guillard, François; Golshan, Pouya; Shen, Luming; Valdès, Julio R.; Einav, Itai

    2017-06-01

    Compaction of brittle porous material leads to a wide variety of densification patterns. Static compaction bands occurs naturally in rocks or bones, and have important consequences in industry for the manufacturing of powder tablets or metallic foams for example. Recently, oscillatory compaction bands have been observed in brittle porous media like snow or cereals. We will discuss the great variety of densification patterns arising during the compaction of puffed rice, including erratic compaction at low velocity, one or several travelling compaction bands at medium velocity and homogeneous compaction at larger velocity. The conditions of existence of each pattern are studied thanks to a numerical spring lattice model undergoing breakage and is mapped to the phase diagram of the patterns based on dimensionless characteristic quantities. This also allows to rationalise the evolution of the compaction behaviour during a single test. Finally, the localisation of compaction bands is linked to the strain rate sensitivity of the material.

  4. 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

  5. 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

  6. How to orient the functional GroEL-SR1 mutant for atomic force microscopy investigations

    International Nuclear Information System (INIS)

    Schiener, Jens; Witt, Susanne; Hayer-Hartl, Manajit; Guckenberger, Reinhard

    2005-01-01

    We present high-resolution atomic force microscopy (AFM) imaging of the single-ring mutant of the chaperonin GroEL (SR-EL) from Escherichia coli in buffer solution. The native GroEL is generally unsuitable for AFM scanning as it is easily being bisected by forces exerted by the AFM tip. The single-ring mutant of GroEL with its simplified composition, but unaltered capability of binding substrates and the co-chaperone GroES, is a more suited system for AFM studies. We worked out a scheme to systematically investigate both the apical and the equatorial faces of SR-EL, as it binds in a preferred orientation to hydrophilic mica and hydrophobic highly ordered pyrolytic graphite. High-resolution topographical imaging and the interaction of the co-chaperone GroES were used to assign the orientations of SR-EL in comparison with the physically bisected GroEL. The usage of SR-EL facilitates single molecule studies on the folding cycle of the GroE system using AFM

  7. Operational Status of PF-Ring and PF-AR after the Earthquake

    International Nuclear Information System (INIS)

    Honda, T; Asaoka, S; Haga, K; Harada, K; Honda, Y; Izawa, M; Kamiya, Y; Kobayashi, Y; Miyajima, T; Miyauchi, H; Nagahashi, S; Nakamura, N; Nogami, T; Obina, T; Ozaki, T; Sagehashi, H; Sakai, H; Sakanaka, S; Sasaki, H; Sato, Y

    2013-01-01

    In 2011, two SR sources of KEK, PF-ring and PF-AR, needed to change the operation schedule because of the unprecedented earthquake on March 11. Though the injector linac and the storage rings suffered a serious damage, temporary recovery was accomplished quickly and the trial operation started in May. The regular user operation could be resumed in October 2011. In the restoration work after the earthquake, some old vacuum components were removed from PF-ring. This work fortunately brought an effect of settling the quadrupole-mode longitudinal instability. For the top-up injection of PF-ring, the pulsed sextupole magnet has been used instead of the conventional kicker magnets since 2011. The hybrid-fill mode in place of the single-bunch mode has become available. Recently, the 10-Hz orbit switching for the tandem circularly polarized undulators has been developed for the user operation.

  8. Does the sun ring

    International Nuclear Information System (INIS)

    Isaak, G.R.

    1978-01-01

    The work of various groups, which have been investigating the possibility of measuring the periodicities of solar oscillations in an attempt to test theoretical models of the sun, is reported. In particular the observation of small velocity oscillations of the surface layers of the sun that permits the measurement of the sound waves (or phonons) in the solar atmosphere, is discussed. Oscillations with periods of 2.65 h, 58 and 40 min and amplitudes of 2.7, 0.8 and 0.7 ms -1 respectively are reported. Support for a periodicity at about 2.65 h from a number of other groups using other measuring techniques are considered. It is felt that the most probable interpretation of the observed solar oscillations is that the sun is a resonator which is ringing. (UK)

  9. Inverse compton light source: a compact design proposal

    Energy Technology Data Exchange (ETDEWEB)

    Deitrick, Kirsten Elizabeth [Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2017-05-01

    In the last decade, there has been an increasing demand for a compact Inverse Compton Light Source (ICLS) which is capable of producing high-quality X-rays by colliding an electron beam and a high-quality laser. It is only in recent years when both SRF and laser technology have advanced enough that compact sources can approach the quality found at large installations such as the Advanced Photon Source at Argonne National Laboratory. Previously, X-ray sources were either high flux and brilliance at a large facility or many orders of magnitude lesser when produced by a bremsstrahlung source. A recent compact source was constructed by Lyncean Technologies using a storage ring to produce the electron beam used to scatter the incident laser beam. By instead using a linear accelerator system for the electron beam, a significant increase in X-ray beam quality is possible, though even subsequent designs also featuring a storage ring offer improvement. Preceding the linear accelerator with an SRF reentrant gun allows for an extremely small transverse emittance, increasing the brilliance of the resulting X-ray source. In order to achieve sufficiently small emittances, optimization was done regarding both the geometry of the gun and the initial electron bunch distribution produced off the cathode. Using double-spoke SRF cavities to comprise the linear accelerator allows for an electron beam of reasonable size to be focused at the interaction point, while preserving the low emittance that was generated by the gun. An aggressive final focusing section following the electron beam's exit from the accelerator produces the small spot size at the interaction point which results in an X-ray beam of high flux and brilliance. Taking all of these advancements together, a world class compact X-ray source has been designed. It is anticipated that this source would far outperform the conventional bremsstrahlung and many other compact ICLSs, while coming closer to performing at the

  10. Compact objects and accretion disks

    NARCIS (Netherlands)

    Blandford, Roger; Agol, Eric; Broderick, Avery; Heyl, Jeremy; Koopmans, Leon; Lee, Hee-Won

    2002-01-01

    Recent developments in the spectropolarimetric study of compact objects, specifically black holes (stellar and massive) and neutron stars are reviewed. The lectures are organized around five topics: disks, jets, outflows, neutron stars and black holes. They emphasize physical mechanisms and are

  11. Engineering aspects of compact stellarators

    International Nuclear Information System (INIS)

    Nelson, B.E.; Benson, R.D.; Brooks, A.

    2003-01-01

    Compact stellarators could combine the good confinement and high beta of a tokamak with the inherently steady state, disruption-free characteristics of a stellarator. Two U.S. compact stellarator facilities are now in the conceptual design phase: the National Compact Stellarator Experiment (NCSX) and the Quasi- Poloidal Stellarator (QPS). NCSX has a major radius of 1.4 m and a toroidal field up to 2 T. The primary feature of both NCSX and QPS is the set of modular coils that provide the basic magnetic configuration. These coils represent a major engineering challenge due to the complex shape, precise geometric accuracy, and high current density of the windings. The winding geometry is too complex for conventional hollow copper conductor construction. Instead, the modular coils will be wound with flexible, multi strand cable conductor that has been compacted to a 75% copper packing fraction. Inside the NCSX coil set and surrounding the plasma is a highly contoured vacuum vessel. The vessel consists of three identical, 120 deg. segments that are bolted together at double sealed joints. The QPS device has a major radius of 0.9 m, a toroidal field of 1 T, and an aspect ratio of only 2.7. Instead of an internal vacuum vessel, the QPS modular coils will operate in an external vacuum tank. (author)

  12. Compact Circuit Preprocesses Accelerometer Output

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1993-01-01

    Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.

  13. Rapid method for determining Sr-89 and Sr-90 using Cherenkov and proportional counting; Schnellmethode zur Bestimmung von SR-89 und SR-90 durch Cerenkov- und Proportionalzaehlermessungen

    Energy Technology Data Exchange (ETDEWEB)

    Lange, S.; Wende, C.; Schwokowski, R.; Alisch-Mark, M.; Abraham, A.; Heinrich, T. [Staatliche Betriebsgesellschaft fuer Umwelt und Landwirtschaft, Radebeul (Germany)

    2016-07-01

    A rapid method for determining Sr-89 and Sr-90 in water, milk and biological samples has been developed and tested. After sample preparation strontium is separated by extraction chromatography using Sr resin. Eluate is divided and transfered to LSC vial and filter paper by SrCO{sub 3} precipitation. A Hidex 300 SL TDCR liquid scintillation counter and Thermo Fisher low level proportional counter have been used. Chemical yield of Sr-85 tracer is determined by Gamma spectroscopy. Uncertainty budget, decision threshold and detection limit are calculated in accordance with GUM and ISO 11929.

  14. Optical bio-chemical sensors on SNOW ring resonators

    Science.gov (United States)

    Khorasaninejad, Mohammadreza; Clarke, Nigel; Anantram, M. P.; Singh Saini, Simarjeet

    2011-08-01

    In this paper, we propose and analyze novel ring resonator based bio-chemical sensors on silicon nanowire optical waveguide (SNOW) and show that the sensitivity of the sensors can be increased by an order of magnitude as compared to silicon-on-insulator based ring resonators while maintaining high index contrast and compact devices. The core of the waveguide is hollow and allows for introduction of biomaterial in the center of the mode, thereby increasing the sensitivity of detection. A sensitivity of 243 nm/refractive index unit (RIU) is achieved for a change in bulk refractive index. For surface attachment, the sensor is able to detect monolayer attachments as small as 1 Å on the surface of the silicon nanowires.

  15. Optimizing ring-based CSR sources

    International Nuclear Information System (INIS)

    Byrd, J.M.; De Santis, S.; Hao, Z.; Martin, M.C.; Munson, D.V.; Li, D.; Nishimura, H.; Robin, D.S.; Sannibale, F.; Schlueter, R.D.; Schoenlein, R.; Jung, J.Y.; Venturini, M.; Wan, W.; Zholents, A.A.; Zolotorev, M.

    2004-01-01

    . Propagating around an electron storage ring, this bunch develops a longitudinal density perturbation due to the dispersion of electron trajectories. This perturbation emits short pulses of temporally and spatially coherent terahertz pulses that are inherently synchronized to the modulating laser. Although this technique was originally developed for producing ultrashort x-ray pulses, the CSR emission has interesting possibilities as a source. In this paper, we present several of the concepts for optimizing a ring for producing both stable CSR and ultrashort terahertz pulses from laser sliced beams in the context of CIRCE (Coherent InfraRed CEnter), a ring we have proposed which incorporates many of these concepts. Many of these concepts were originally inspired by a compact CSR source described by Murphy et al.. The first section of this paper presents several general considerations for an optimized CSR ring and is followed by details of CIRCE

  16. Compaction and relaxation of biofilms

    KAUST Repository

    Valladares Linares, R.

    2015-06-18

    Operation of membrane systems for water treatment can be seriously hampered by biofouling. A better characterization of biofilms in membrane systems and their impact on membrane performance may help to develop effective biofouling control strategies. The objective of this study was to determine the occurrence, extent and timescale of biofilm compaction and relaxation (decompaction), caused by permeate flux variations. The impact of permeate flux changes on biofilm thickness, structure and stiffness was investigated in situ and non-destructively with optical coherence tomography using membrane fouling monitors operated at a constant crossflow velocity of 0.1 m s−1 with permeate production. The permeate flux was varied sequentially from 20 to 60 and back to 20 L m−2 h−1. The study showed that the average biofilm thickness on the membrane decreased after elevating the permeate flux from 20 to 60 L m−2 h−1 while the biofilm thickness increased again after restoring the original flux of 20 L m−2 h−1, indicating the occurrence of biofilm compaction and relaxation. Within a few seconds after the flux change, the biofilm thickness was changed and stabilized, biofilm compaction occurred faster than the relaxation after restoring the original permeate flux. The initial biofilm parameters were not fully reinstated: the biofilm thickness was reduced by 21%, biofilm stiffness had increased and the hydraulic biofilm resistance was elevated by 16%. Biofilm thickness was related to the hydraulic biofilm resistance. Membrane performance losses are related to the biofilm thickness, density and morphology, which are influenced by (variations in) hydraulic conditions. A (temporarily) permeate flux increase caused biofilm compaction, together with membrane performance losses. The impact of biofilms on membrane performance can be influenced (increased and reduced) by operational parameters. The article shows that a (temporary) pressure increase leads to more

  17. How Jupiter's Ring Was Discovered.

    Science.gov (United States)

    Elliot, James; Kerr, Richard

    1985-01-01

    "Rings" (by astronomer James Elliot and science writer Richard Kerr) is a nontechnical book about the discovery and exploration of ring systems from the time of Galileo to the era of the Voyager spacecraft. One of this book's chapters is presented. (JN)

  18. 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

  19. Optimization of superconducting bending magnets for a 1.0 to 1.5 GeV compact light source

    International Nuclear Information System (INIS)

    Green, M.A.; Garren, A.A.

    1995-06-01

    Compact light sources are being proposed for protein crystallography, medical imaging, nano-machining and other areas of study that require intense sources of x rays at energies up to 35 keV. In order for a synchrotron light source to be attractive, its capital cost must, be kept low. The proposed compact light source has superconducting bending elements to bend the stored beam and produce the x rays. Additional focusing for the machine is provided by conventional quadrupoles. An important part of the cost optimization of a compact light source is the cost of the bending magnets. In the case of a machine with superconducting bending elements, the bending magnet system can represent close to half of the storage ring cost. The compact light source storage rings studied here have a range of stored electron energies from 1.0 to 1.5 GeV. For a number of reasons, it is desirable to keep the storage ring circumference below 30 meters. Cost optimization parameters include: (1) the number of superconducting bending elements in the ring, and (2) the central induction of the dipole. A machine design that features two superconducting dipoles in a single cryostat vacuum vessel is also discussed

  20. 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.

  1. Beam Optics for FCC-ee Collider Ring

    CERN Document Server

    Oide, Katsunobu; Aumon, S; Benedikt, M; Blondel, A; Bogomyagkov, A V; Boscolo, M; Burkhardt, H; Cai, Y; Doblhammer, A; Haerer, B; Holzer, B; Koop, I; Koratzinos, M; Jowett, John M; Levichev, E B; Medina, L; Ohmi, K; Papaphilippou, Y; Piminov, P A; Shatilov, D N; Sinyatkin, S V; Sullivan, M; Wenninger, J; Wienands, U; Zhou, D; Zimmermann, F

    2017-01-01

    A beam optics scheme has been designed [ 1 ] for the Future Circular Collider- e + e − (FCC-ee). The main characteristics of the design are: beam energy 45 to 175 GeV, 100 km circumference with two interaction points (IPs) per ring, horizontal crossing angle of 30 mrad at the IP and the crab-waist scheme [ 2 ] with local chromaticity correction. The crab-waist scheme is implemented within the local chromaticity correction system without additional sextupoles, by reducing the strength of one of the two sextupoles for vertical chromatic correction at each side of the IP. So- called “tapering" of the magnets is applied, which scales all fields of the magnets according to the local beam energy to compensate for the effect of synchrotron radiation (SR) loss along the ring. An asymmetric layout near the interaction region reduces the critical energy of SR photons on the incoming side of the IP to values below 100 keV, while matching the geometry to the beam line of the FCC proton collider (FCC-hh) [ 3 ] as clos...

  2. Positron Options for the Linac-Ring LHeC

    CERN Document Server

    Zimmermann, F; Papaphilippou, Y; Schulte, D; Sievers, P; Rinolfi, L; Variola, A; Zomer, F; Braun, H H; Yakimenko, V; Bulyak, E V; Klein, M

    2012-01-01

    The full physics program of a future Large Hadron electron Collider (LHeC) [1] requires both pe+ and pe− collisions. For a pulsed 140-GeV or an ERL-based 60-GeV Linac-Ring LHeC this implies a challenging rate of, respectively, about 1.8 × 1015 or 4.4 × 1016 e+/s at the collision point, which is about 300 or 7000 times the rate previously obtained, at the SLAC Linear Collider (SLC). We consider providing this e+ rate through a combination of measures: (1) Reducing the required production rate from the e+ target through colliding e+ (and the LHC protons) several times before deceleration, by reusing the e+ over several acceleration/deceleration cycles, and by cooling them, e.g., with a compact tri-ring scheme or a conventional damping ring in the SPS tunnel. (2) Using an advanced target, e.g., W-granules, rotating wheel, slicedrod converter, or liquid metal jet, for converting gamma rays to e+. (3) Selecting the most powerful of several proposed gamma sources, namely Compton ERL, Compton storage ring, coher...

  3. Alstom Francis Turbine Ring Gates: from Retrofitting to Commissioning

    Science.gov (United States)

    A, Nguyen P.; G, Labrecque; M-O, Thibault; M, Bergeron; A, Steinhilber; D, Havard

    2014-03-01

    The Ring Gate synchronisation system developed by Alstom is new and patented. It uses hydraulic cylinders connected in pairs by a serial connection. The new hydraulic synchronisation system, when compared to the previous mechanical synchronisation system, has several advantages. It is a compact design; it reduces the number of mechanical components as well as maintenance costs. The new system maintains the Ring Gates robustness. The new approach is an evolution from mechanical to hydraulic synchronization assisted by electronic control. The new synchronization system eliminates several mechanical components that used to add wear and friction and which are usually difficult to adjust during maintenance. Tension chains and sprockets and associated controls are eliminated. Through the position sensors, the redundancy of the ring gate synchronization system makes it predictable and reliable. The electronic control compensates for any variation in operation, for example a leak in the hydraulic system. An emergency closing is possible without the electronic control system due to the stiffness of hydraulic serial connection in the hydraulic cylinder pairs. The Ring Gate can work safely against uneven loads and frictions. The development will be reviewed and its application discussed through commissioning results.

  4. Alstom Francis Turbine Ring Gates: from Retrofitting to Commissioning

    International Nuclear Information System (INIS)

    Nguyen P A; Labrecque G; Thibault M-O; Bergeron M; Steinhilber A; Havard D

    2014-01-01

    The Ring Gate synchronisation system developed by Alstom is new and patented. It uses hydraulic cylinders connected in pairs by a serial connection. The new hydraulic synchronisation system, when compared to the previous mechanical synchronisation system, has several advantages. It is a compact design; it reduces the number of mechanical components as well as maintenance costs. The new system maintains the Ring Gates robustness. The new approach is an evolution from mechanical to hydraulic synchronization assisted by electronic control. The new synchronization system eliminates several mechanical components that used to add wear and friction and which are usually difficult to adjust during maintenance. Tension chains and sprockets and associated controls are eliminated. Through the position sensors, the redundancy of the ring gate synchronization system makes it predictable and reliable. The electronic control compensates for any variation in operation, for example a leak in the hydraulic system. An emergency closing is possible without the electronic control system due to the stiffness of hydraulic serial connection in the hydraulic cylinder pairs. The Ring Gate can work safely against uneven loads and frictions. The development will be reviewed and its application discussed through commissioning results

  5. 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.

  6. Rate type isotach compaction of consolidated sandstone

    NARCIS (Netherlands)

    Waal, J.A. de; Thienen-Visser, K. van; Pruiksma, J.P.

    2015-01-01

    Laboratory experiments on samples from a consolidated sandstone reservoir are presented that demonstrate rate type compaction behaviour similar to that observed on unconsolidated sands and soils. Such rate type behaviour can have large consequences for reservoir compaction, surface subsidence and

  7. Siting actions in compacts and nonmember states

    International Nuclear Information System (INIS)

    Tullis, J.

    1986-05-01

    This paper examines the status of siting actions in those compacts and states currently progressing with siting studies. The efforts of the Central Compact Commission, Texas, California, Colorado and Illinois are highlighted to illustrate progress, methodology, and problems encountered

  8. CHESS upgrade with compact undulator magnets: Operating experience and first results

    Energy Technology Data Exchange (ETDEWEB)

    Temnykh, A., E-mail: abt6@cornell.edu; Dale, D.; Fontes, E.; Lyndaker, A.; Li, Y.; Ruff, J.; Revesz, P.; Woll, A. [Cornell High Energy Synchrotron Source (United States)

    2016-07-27

    In November 2014 two in-air 1.5 m CHESS Compact Undulator (CCU) magnets built by KYMA S.R.l. were installed in Cornell Electron Storage Ring (CESR) in canted arrangement and after few days of commissioning their regular operation started. CCU magnets are compact, lightweight and cost efficient devices. They have very stable magnetic field integrals independent of deflection parameter value. This feature greatly simplifies the storage ring operation. The CCU concept was developed at Cornell in 2011 and the first 1 m in-vacuum CCU magnet was beam-tested in 2012. The article presents CCU concept and some details of the design. It describes also the layout of CCUs installation in CESR, their performance and characteristics. The current status of operation and future plans are discussed as well. Presently, at CHESS two CCU magnets provide radiation for 5 out of 11 experimental stations.

  9. CHESS upgrade with compact undulator magnets: Operating experience and first results

    International Nuclear Information System (INIS)

    Temnykh, A.; Dale, D.; Fontes, E.; Lyndaker, A.; Li, Y.; Ruff, J.; Revesz, P.; Woll, A.

    2016-01-01

    In November 2014 two in-air 1.5 m CHESS Compact Undulator (CCU) magnets built by KYMA S.R.l. were installed in Cornell Electron Storage Ring (CESR) in canted arrangement and after few days of commissioning their regular operation started. CCU magnets are compact, lightweight and cost efficient devices. They have very stable magnetic field integrals independent of deflection parameter value. This feature greatly simplifies the storage ring operation. The CCU concept was developed at Cornell in 2011 and the first 1 m in-vacuum CCU magnet was beam-tested in 2012. The article presents CCU concept and some details of the design. It describes also the layout of CCUs installation in CESR, their performance and characteristics. The current status of operation and future plans are discussed as well. Presently, at CHESS two CCU magnets provide radiation for 5 out of 11 experimental stations.

  10. Powder compaction in systems of bimodal distribution

    Science.gov (United States)

    Chattopadhyay, A. K.; Whittemore, O. J., Jr.

    1973-01-01

    The compaction of mixtures involving different particle sizes is discussed. The various stages of the compaction process include the rearrangement of particles, the filling of the interstices of the large particles by the smaller ones, and the change in particle size and shape upon further densification through the application of pressure. Experimental approaches and equipment used for compacting material are discussed together with the theoretical relations of the compacting process.

  11. UV written compact broadband optical couplers

    DEFF Research Database (Denmark)

    Olivero, Massimo; Svalgaard, Mikael

    2005-01-01

    In this paper the first demonstration of compact asymmetric directional couplers made by UV writing is presented. The combined performance in terms bandwidth, loss and compactness exceeds that reported using other, more elaborate fabrication techniques.......In this paper the first demonstration of compact asymmetric directional couplers made by UV writing is presented. The combined performance in terms bandwidth, loss and compactness exceeds that reported using other, more elaborate fabrication techniques....

  12. 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)

  13. Invariant subsets under compact quantum group actions

    OpenAIRE

    Huang, Huichi

    2012-01-01

    We investigate compact quantum group actions on unital $C^*$-algebras by analyzing invariant subsets and invariant states. In particular, we come up with the concept of compact quantum group orbits and use it to show that countable compact metrizable spaces with infinitely many points are not quantum homogeneous spaces.

  14. Equationally Compact Acts : Coproducts / Peeter Normak

    Index Scriptorium Estoniae

    Normak, Peeter

    1998-01-01

    In this article equational compactness of acts and its generalizations are discussed. As equational compactness does not carry over to coproducts a slight generalization of c-equational campactness is introduced. It is proved that a coproduct of acts is c-equationally compact if and only if all components are c-equationally campact

  15. Formation and evolution of compact binaries

    NARCIS (Netherlands)

    Sluijs, Marcel Vincent van der

    2006-01-01

    In this thesis we investigate the formation and evolution of compact binaries. Chapters 2 through 4 deal with the formation of luminous, ultra-compact X-ray binaries in globular clusters. We show that the proposed scenario of magnetic capture produces too few ultra-compact X-ray binaries to explain

  16. Commissioning results of the APS storage ring rf beam position monitors

    International Nuclear Information System (INIS)

    Kahana, E.; Chung, Y.

    1996-01-01

    The commissioning of the 360 rf beam position monitors (BPMs) in the Advanced Photon Source (APS) storage ring (SR) is nearing completion. After using the single-turn capability of the BPM electronics in the early ring commissioning phase, resolution measurements versus current and bandwidth were successfully performed. In the standard Sr vacuum chamber geometry, the resolution was measured with beam as 0.16 micromA/√(Hz). For the insertion device vacuum chamber geometry, the resolution was measured to be 0.1 micromA/√(Hz). Since the photon beam stability requirement for the users is only 4.5 microns rms in the vertical direction, investigations of rf BPM offset versus current and bunch pattern have also been initiated. Both single bunch and multibunch beam patterns with varying intensity were used to determine offset stability for both the global and the local orbit feedback applications

  17. 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.

  18. Is the bell ringing?

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    During the Nobel prize-winning UA1 experiment, scientists in the control room used to ring a bell if a particularly interesting event had occurred. Today, the “CMS Exotica hotline” routine produces a daily report that lists the exotic events that were recorded the day before.   Display of an event selected by the Exotica routine. Take just a very small fraction of the available data (max. 5%); define the events that you want to keep and set the parameters accordingly; run the Exotica routine and only look at the very few images that the system has selected for you. This is the recipe that a small team of CMS researchers has developed to identify the signals coming from possible new physics processes. “This approach does not replace the accurate data analysis on the whole set of data. However, it is a very fast and effective way to focus on just a few events that are potentially very interesting”, explains Maurizio Pierini (CERN), who developed the...

  19. 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)

  20. Characteristic features of the magnetoresistance in the ferrimagnetic (Sr2FeMoO6-δ) - dielectric (SrMoO4) nanocomposite

    Science.gov (United States)

    Demyanov, S.; Kalanda, N.; Yarmolich, M.; Petrov, A.; Lee, S.-H.; Yu, S.-C.; Oh, S. K.; Kim, D.-H.

    2018-05-01

    Magnetic metal-oxide compounds with high values of magnetoresistance (MR) have attracted huge interest for spintronic applications, among which Sr2FeMoO6-δ (SFMO) has been relatively less known compared to the cobaltites and manganites, despite 100% electrons spin-polarization degree and a high Curie temperature. Here, stable fabrication and systematic analysis of nanocomposites based on SFMO with SrMoO4 dielectric sheaths are presented. SFMO-SrMoO4 nanocomposites were fabricated as follows: synthesis of the SFMO single-phase nanopowders by the modified citrate-gel technique; compaction under high pressure; thermal treatment for sheaths formation around grains. The nanocomposite is observed to exhibit a transitional behavior of conductivity from metallic, which is characteristic for the SFMO to semiconductor one in the temperature range 4 - 300K under magnetic fields up to 10T. A negative MR is observed due to the spin-polarized charge carriers tunneling through dielectric sheaths. MR value reaches 43% under 8T at 10κ. The dielectric sheaths thickness was determined to be about 10 nm by electric breakdown voltage value at current-voltage characteristics curves. The breakdown is found to be a reversible process determined by collisional ionization of dielectric atoms in strong electric field depending on knocked-out electrons from the SrMoO4. It was found that MR changes sign in electric breakdown region, revealing the giant magnetoresistive properties.

  1. Compact sources for eyesafe illumination

    Science.gov (United States)

    Baranova, Nadia; Pu, Rui; Stebbins, Kenneth; Bystryak, Ilya; Rayno, Michael; Ezzo, Kevin; DePriest, Christopher

    2018-02-01

    Q-peak has demonstrated a compact, pulsed eyesafe laser architecture operating with >10 mJ pulse energies at repetition rates as high as 160 Hz. The design leverages an end-pumped solid-state laser geometry to produce adequate eyesafe beam quality (M2˜4), while also providing a path toward higher-density laser architectures for pulsed eyesafe applications. The baseline discussed in this paper has shown a unique capability for high-pulse repetition rates in a compact package, and offers additional potential for power scaling based on birefringence compensation. The laser consists of an actively Q-switched oscillator cavity producing pulse widths designed to fit within a volume of 3760 cm3. We will discuss details of the optical system design, modeled thermal effects and stress-induced birefringence, as well as experimental advantages of the end-pumped laser geometry, along with proposed paths to higher eyesafe pulse energies.

  2. Magnetohydrodynamical processes near compact objects

    International Nuclear Information System (INIS)

    Bisnovatyi Kogan, G.S.

    1979-01-01

    Magnetohydrodynamical processes near compact objects are reviewed in this paper. First the accretion of the magnetized matter into a single black hole and spectra of radiation are considered. Then the magnetic-field phenomena in the disk accretion, when the black hole is in a pair are discussed. Furthermore, the magnetohydrodynamics phenomena during supernova explosion are considered. Finally the magnetohydrodynamics in the accretion of a neutron star is considered in connection With x-ray sources

  3. Compact toroids with Alfvenic flows

    International Nuclear Information System (INIS)

    Wang Zhehui; Tang, X.Z.

    2004-01-01

    The Chandrasekhar equilibria form a class of stationary ideal magnetohydrodynamics equilibria stabilized by magnetic-field-aligned Alfvenic flows. Analytic solutions of the Chandrasekhar equilibria are explicitly constructed for both field-reversed configurations and spheromaks. Favorable confinement property of nested closed flux surfaces and the ideal magnetohydrodynamic stability of the compact toroids are of interest for both magnetic trapping of high energy electrons in astrophysics and confinement of high temperature plasmas in laboratory

  4. Toward a New Test of the Relativistic Time Dilation Factor by Laser Spectroscopy of Fast Ions in a Storage Ring

    International Nuclear Information System (INIS)

    Saathoff, G.; Eisenbarth, U.; Hannemann, S.; Hoog, I.; Huber, G.; Karpuk, S.; Krohn, S.; Lassen, J.; Schwalm, D.; Weidemueller, M.; Wolf, A.; Gwinner, G.

    2003-01-01

    The frequency measurement of Doppler-shifted optical lines of ions circulating in a storage ring at high speed permits a sensitive test of the relativistic Doppler-formula and, hence, the time dilation factor γ SR of special relativity. Previous measurements at the storage ring TSR with 7 Li + at v=0.065c gave a new, improved limit, but were hampered by the large observed linewidth, exceeding the natural width 15-fold. Recently we have identified the broadening to be caused by velocity-changing processes in the storage ring. Saturation spectroscopy has proven to be largely immune against these effects and has yielded linewidths only a few MHz larger than the natural one. This is the major ingredient for an improved test of γ SR , which is now under way.

  5. Toward a New Test of the Relativistic Time Dilation Factor by Laser Spectroscopy of Fast Ions in a Storage Ring

    Energy Technology Data Exchange (ETDEWEB)

    Saathoff, G.; Eisenbarth, U.; Hannemann, S. [Max-Planck-Institut fuer Kernphysik (Germany); Hoog, I.; Huber, G.; Karpuk, S. [Universitaet Mainz, Institut fuer Physik (Germany); Krohn, S. [Max-Planck-Institut fuer Kernphysik (Germany); Lassen, J. [Universitaet Mainz, Institut fuer Physik (Germany); Schwalm, D.; Weidemueller, M.; Wolf, A.; Gwinner, G. [Max-Planck-Institut fuer Kernphysik (Germany)

    2003-03-15

    The frequency measurement of Doppler-shifted optical lines of ions circulating in a storage ring at high speed permits a sensitive test of the relativistic Doppler-formula and, hence, the time dilation factor {gamma}{sub SR} of special relativity. Previous measurements at the storage ring TSR with {sup 7}Li{sup +} at v=0.065c gave a new, improved limit, but were hampered by the large observed linewidth, exceeding the natural width 15-fold. Recently we have identified the broadening to be caused by velocity-changing processes in the storage ring. Saturation spectroscopy has proven to be largely immune against these effects and has yielded linewidths only a few MHz larger than the natural one. This is the major ingredient for an improved test of {gamma}{sub SR}, which is now under way.

  6. 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...

  7. Durability of Self Compacting Concrete

    International Nuclear Information System (INIS)

    Benmarce, A.; Boudjehem, H.; Bendjhaiche, R.

    2011-01-01

    Self compacting concrete (SCC) seem to be a very promising materials for construction thanks to their properties in a fresh state. Studying of the influence of the parameters of specific designed mixes to their mechanical, physical and chemical characteristics in a state hardened is an important stage so that it can be useful for new-to-the-field researchers and designers (worldwide) beginning studies and work involving self compacting concrete. The objective of this research is to study the durability of self compacting concrete. The durability of concrete depends very much on the porosity; the latter determines the intensity of interactions with aggressive agents. The pores inside of concrete facilitate the process of damage, which began generally on the surface. We are interested to measure the porosity of concrete on five SCC with different compositions (w/c, additives) and vibrated concrete to highlight the influence of the latter on the porosity, thereafter on the compressive strength and the transfer properties (oxygen permeability, chloride ion diffusion, capillary absorption). (author)

  8. Comminution circuits for compact itabirites

    Directory of Open Access Journals (Sweden)

    Pedro Ferreira Pinto

    Full Text Available Abstract In the beneficiation of compact Itabirites, crushing and grinding account for major operational and capital costs. As such, the study and development of comminution circuits have a fundamental importance for feasibility and optimization of compact Itabirite beneficiation. This work makes a comparison between comminution circuits for compact Itabirites from the Iron Quadrangle. The circuits developed are: a crushing and ball mill circuit (CB, a SAG mill and ball mill circuit (SAB and a single stage SAG mill circuit (SSSAG. For the SAB circuit, the use of pebble crushing is analyzed (SABC. An industrial circuit for 25 million tons of run of mine was developed for each route from tests on a pilot scale (grinding and industrial scale. The energy consumption obtained for grinding in the pilot tests was compared with that reported by Donda and Bond. The SSSAG route had the lowest energy consumption, 11.8kWh/t and the SAB route had the highest energy consumption, 15.8kWh/t. The CB and SABC routes had a similar energy consumption of 14.4 kWh/t and 14.5 kWh/t respectively.

  9. Strange matter in compact stars

    Science.gov (United States)

    Klähn, Thomas; Blaschke, David B.

    2018-02-01

    We discuss possible scenarios for the existence of strange matter in compact stars. The appearance of hyperons leads to a hyperon puzzle in ab-initio approaches based on effective baryon-baryon potentials but is not a severe problem in relativistic mean field models. In general, the puzzle can be resolved in a natural way if hadronic matter gets stiffened at supersaturation densities, an effect based on the quark Pauli quenching between hadrons. We explain the conflict between the necessity to implement dynamical chiral symmetry breaking into a model description and the conditions for the appearance of absolutely stable strange quark matter that require both, approximately masslessness of quarks and a mechanism of confinement. The role of strangeness in compact stars (hadronic or quark matter realizations) remains unsettled. It is not excluded that strangeness plays no role in compact stars at all. To answer the question whether the case of absolutely stable strange quark matter can be excluded on theoretical grounds requires an understanding of dense matter that we have not yet reached.

  10. Strange matter in compact stars

    Directory of Open Access Journals (Sweden)

    Klähn Thomas

    2018-01-01

    Full Text Available We discuss possible scenarios for the existence of strange matter in compact stars. The appearance of hyperons leads to a hyperon puzzle in ab-initio approaches based on effective baryon-baryon potentials but is not a severe problem in relativistic mean field models. In general, the puzzle can be resolved in a natural way if hadronic matter gets stiffened at supersaturation densities, an effect based on the quark Pauli quenching between hadrons. We explain the conflict between the necessity to implement dynamical chiral symmetry breaking into a model description and the conditions for the appearance of absolutely stable strange quark matter that require both, approximately masslessness of quarks and a mechanism of confinement. The role of strangeness in compact stars (hadronic or quark matter realizations remains unsettled. It is not excluded that strangeness plays no role in compact stars at all. To answer the question whether the case of absolutely stable strange quark matter can be excluded on theoretical grounds requires an understanding of dense matter that we have not yet reached.

  11. Generator of a dense atomic gas curtain (for use in Intersecting Storage Rings)

    CERN Document Server

    Zankel, K

    1975-01-01

    A supersonic beam source is described which continuously generates a gas curtain for the proton beam profile observation in the Intersecting Storage Rings at CERN. Its maximum intensity is 10/sup 20 / atoms/sr s. A commonly used theoretical model for the determination of the intensity downstream of the source is discussed. Some results about the condensation behaviour of sodium vapour on metallic substrate surfaces are reported. (8 refs).

  12. Polarized particles in storage rings

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Kondratenko, A.M.; Serednyakov, S.I.; Skrinskij, A.N.; Tumajkin, G.M.; Shatunov, Yu.M.

    1977-01-01

    Experiments with polarized beams on the VEPP-2M and SPEAK storage rings are described. Possible methods of producing polarized particle beams in storage rings as well as method of polarization monitoring are counted. Considered are the processes of radiation polarization of electrons and positrons. It is shown, that to preserve radiation polarization the introduction of regions with a strong sign-variable magnetic field is recommended. Methods of polarization measurement are counted. It is suggested for high energies to use dependence of synchrotron radiation power on transverse polarization of electrons and positrons. Examples of using polarizability of colliding beams in storage rings are presented

  13. 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

  14. Soft Congruence Relations over Rings

    Science.gov (United States)

    Xin, Xiaolong; Li, Wenting

    2014-01-01

    Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainty. In this paper, we initiate the study of soft congruence relations by using the soft set theory. The notions of soft quotient rings, generalized soft ideals and generalized soft quotient rings, are introduced, and several related properties are investigated. Also, we obtain a one-to-one correspondence between soft congruence relations and idealistic soft rings and a one-to-one correspondence between soft congruence relations and soft ideals. In particular, the first, second, and third soft isomorphism theorems are established, respectively. PMID:24949493

  15. Distributively generated matrix near rings

    International Nuclear Information System (INIS)

    Abbasi, S.J.

    1993-04-01

    It is known that if R is a near ring with identity then (I,+) is abelian if (I + ,+) is abelian and (I,+) is abelian if (I*,+) is abelian [S.J. Abbasi, J.D.P. Meldrum, 1991]. This paper extends these results. We show that if R is a distributively generated near ring with identity then (I,+) is included in Z(R), the center of R, if (I + ,+) is included in Z(M n (R)), the center of matrix near ring M n (R). Furthermore (I,+) is included in Z(R) if (I*,+) is included in Z(M n (R)). (author). 5 refs

  16. 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...

  17. Cabling design of booster and storage ring construction progress of TPS

    International Nuclear Information System (INIS)

    Wong, Y.-S.; Liu, K.-B.; Liu, C.-Y.; Wang, B.-S.

    2017-01-01

    The 2012 Taiwan Photon Source (TPS) cable construction project started after 10 months to complete the cable laying and installation of power supply. The circumference of the booster ring (BR) is 496.8 m, whereas that of the storage ring (SR) is 518.4 m. Beam current is set to 500 mA at 3.3 GeV. The paper on grounding systems discusses the design of the ground wire (< 0.2 Ω) with low impedance, power supply of the accelerator and cabling tray. The flow and size of the ground current are carefully evaluated to avoid grounded current from flowing everywhere, which causes interference problems. In the design of the TPS, special shielding will be established to isolate the effects of electromagnetic interference on the magnet and ground current. Booster ring dipoles are connected by a series of 54-magnet bending dipole; the cable size of its stranded wire measures 250 mm"2, with a total length of 5000 m. Booster ring and storage ring quadrupoles have 150 magnets; the cable size of their stranded wire is 250 mm"2, with a total length of 17000 m. Storage ring dipole consists of 48 magnets; the cable size of its stranded wire is 325 mm"2, with a total length of 6000 m. This study discusses the power supply cabling design of the storage ring and booster ring construction progress of TPS. The sections of this paper are divided into discussions of the construction of the control and instrument area, cabling layout of booster ring and storage ring, as well as the installation and commission machine. This study also discusses the use of a high-impedance meter to determine the effect of cabling insulation and TPS power supply machine on energy transfer to ensure the use of safe and correct magnet.

  18. Response Of Lowland Rice To Soil Compaction

    International Nuclear Information System (INIS)

    Idawati; Haryanto

    2000-01-01

    Soil compaction, as a new tillage practice for paddy soil, is to substitute pudding in order to reduce land preparation cost. To study response of lowland rice to soil compaction, a pot experiment has been conducted which took place in the greenhouse of P3TIR-BATAN. Soil for experiment was taken from pusakanegara. Two factors (degree of soil compaction and rice variety) were combined. Degree of compaction was split into 3 levels (DI = normal; D215% more compact than normal; 30 % more compact than normal), and rice variety into 2 levels (IR64 and Atomita IV). KH 2 32 PO 4 solution was injected into the soil surrounding rice clump to test the root activity at blooming stage of rice plant. Data resulted from this experiment is presented together with additional data from some other experiments of fertilization in the research s erie to study soil compaction. Some information's from experiment results are as following. Both rice varieties tested gave the same response to soil compaction. Root activity, according to data of 32 P absorbed by plant, was not harmed by soil compaction at the degree tested in the experiment. This prediction is supported by the growth by rice observed at generative growth stage, in pot experiment as well as in field experiment, which showed that soil compaction tested did not decrease rice yield but in opposite in tended to increase the yield. In practising soil compaction in land preparation, fertilizers should be applied by deep placement to have higher increasing is rice yield

  19. Prediction of reservoir compaction and surface subsidence

    Energy Technology Data Exchange (ETDEWEB)

    De Waal, J.A.; Smits, R.M.M.

    1988-06-01

    A new loading-rate-dependent compaction model for unconsolidated clastic reservoirs is presented that considerably improves the accuracy of predicting reservoir rock compaction and surface subsidence resulting from pressure depletion in oil and gas fields. The model has been developed on the basis of extensive laboratory studies and can be derived from a theory relating compaction to time-dependent intergranular friction. The procedure for calculating reservoir compaction from laboratory measurements with the new model is outlined. Both field and laboratory compaction behaviors appear to be described by one single normalized, nonlinear compaction curve. With the new model, the large discrepancies usually observed between predictions based on linear compaction models and actual (nonlinear) field behavior can be explained.

  20. Diverse Formation Mechanisms for Compact Galaxies

    Science.gov (United States)

    Kim, Jin-Ah; Paudel, Sanjaya; Yoon, Suk-Jin

    2018-01-01

    Compact, quenched galaxies such as M32 are unusual ones located off the mass - size scaling relation defined by normal galaxies. Still, their formation mechanisms remain unsolved. Here we investigate the evolution of ~100 compact, quenched galaxies at z = 0 identified in the Illustris cosmological simulation. We identify three ways for a galaxy to become a compact one and, often, multiple mechanisms operate in a combined manner. First, stripping is responsible for making about a third of compact galaxies. Stripping removes stars from galaxies, usually while keeping their sizes intact. About one third are galaxies that cease their growth early on after entering into more massive, gigantic halos. Finally, about half of compact galaxies, ~ 35 % of which turn out to undergo stripping, experience the compaction due to the highly centrally concentrated star formation. We discuss the evolutionary path of compact galaxies on the mass – size plane for each mechanism in a broader context of dwarf galaxy formation and evolution.

  1. Rapid determination of 90Sr in seawater

    International Nuclear Information System (INIS)

    Pavlotskaya, F.I.; Moskin, A.I.

    1994-01-01

    A method for determining 90 Sr in seawater that is based on direct isolation and radiochemical purification of daughter 90 Y is proposed. The analysis time is 6-8 h. The chemical yield of the Y-carrier during the 90 Sr determination from 35 liters of seawater varies in the range 37-69%. The analysis uncertainty is 90 Sr from seawater and subsequent isolation of 90 Y

  2. Autumn study on storage rings

    CERN Multimedia

    1974-01-01

    The first two weeks of October have seen storage ring people from accelerator Laboratories throughout the world at CERN to study the fundamental problems of very high energy protonproton colliding beam machines.

  3. 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

  4. Ring lasers - a brief history

    Science.gov (United States)

    Klein, Tony

    2017-10-01

    Used these days in inertial navigation, ring lasers are also used in recording the tiniest variations in the Earth's spin, as well in detecting earthquakes and even the drift of continents. How did it all begin?

  5. Measurement of resonance integral of the 90Sr(n,γ)91Sr reaction

    International Nuclear Information System (INIS)

    Nakamura, Shoji; Furutaka, Kazuyoshi; Wada, Hiroaki; Katoh, Toshio; Harada, Hideo; Fujii, Toshiyuki; Yamana, Hajimu

    2001-01-01

    To obtain fundamental data for research on nuclear transmutation method of radioactive wastes, the resonance integral (I 0 ) of the 90 Sr(n,γ) 91 Sr reaction was measured with an activation method. (author)

  6. Isotope ratio 87Sr/86Sr in limestones from Bambui group, Brazil (MG)

    International Nuclear Information System (INIS)

    Kawashita, K.; Mizusaki, A.M.P.; Kiang, C.H.

    1987-01-01

    The Sr composition of ancient seawater can be estimated from the analysis of carbonate rocks and, in some cases, used to estimate the age of the analyzed carbonate. The normalized 87Sr/86Sr ratios in calcium carbonate fractions from 14 core samples in the Bambui Group near Montalvania, MG, were found to range between .7077 and .7280. The higher values are attributable to Sr isotopic exchange between silicate and carbonate phases during diagenesis. The ratio of .7077 obtained in two pure calcium carbonate samples is here suggested as the best aproximation for the 87Sr/86Sr value for the Bambui sea. This ratio is compatible with an age of about 700 Ma., estimated from the published 87Sr/86Sr curve of Veizer and others, an age in accordance with Quadros recent (1987, in preparation) identification of marine acritarchs from the latest Precambrian (Vendian). (author) [pt

  7. Ring insertions as light sources

    International Nuclear Information System (INIS)

    Green, G.K.

    1975-01-01

    Bending magnets can be inserted in the long straight sections of electron storage rings to produce synchrotron radiation. If the design is carefully proportioned, the bending magnets create only a small perturbation of the properties of the ring. The resulting spectra have favorable optical properties as sources for spectroscopy and diffraction studies. The characteristics of the source are discussed, and the geometrical requirements of the magnets are presented

  8. Collector ring project at FAIR

    International Nuclear Information System (INIS)

    Dolinskii, A; Blell, U; Dimopoulou, C; Gorda, O; Leibrock, H; Litvinov, S; Laier, U; Schurig, I; Weinrich, U; Berkaev, D; Koop, I; Starostenko, A; Shatunov, P

    2015-01-01

    The collector ring is a dedicated ring for fast cooling of ions coming from separators at the FAIR project. To accommodate optimal technical solutions, a structure of a magnet lattice was recently reviewed and modified. Consequently, more appropriate technical solutions for the main magnets could be adopted. A general layout and design of the present machine is shown. The demanding extraction schemes have been detailed and open design issues were completed. (paper)

  9. Synlig læring

    DEFF Research Database (Denmark)

    Brandsen, Mads

    2017-01-01

    Introduktionen af John Hatties synlig læring i den danske skoleverden møder stadig meget kritik. Mange lærere og pædagoger oplever synlig læring som en tornado, der vil opsuge og ødelægge deres særlige danske udgave af den kontinentale dannelsestænkning, didaktik og pædagogik. Spørgsmålet er om...

  10. Electrically charged dilatonic black rings

    International Nuclear Information System (INIS)

    Kunduri, Hari K.; Lucietti, James

    2005-01-01

    In this Letter we present (electrically) charged dilatonic black ring solutions of the Einstein-Maxwell-dilaton theory in five dimensions and we consider their physical properties. These solutions are static and as in the neutral case possess a conical singularity. We show how one may remove the conical singularity by application of a Harrison transformation, which physically corresponds to supporting the charged ring with an electric field. Finally, we discuss the slowly rotating case for arbitrary dilaton coupling

  11. Low emittance electron storage rings

    Science.gov (United States)

    Levichev, E. B.

    2018-01-01

    Low-emittance electron (positron) beams are essential for synchrotron light sources, linear collider damping rings, and circular Crab Waist colliders. In this review, the principles and methods of emittance minimization are discussed, prospects for developing relativistic electron storage rings with small beam phase volume are assessed, and problems related to emittance minimization are examined together with their possible solutions. The special features and engineering implementation aspects of various facilities are briefly reviewed.

  12. Resonance capture and Saturn's rings

    International Nuclear Information System (INIS)

    Patterson, C.W.

    1986-05-01

    We have assigned the resonances apparently responsible for the stabilization of the Saturn's shepherd satellites and for the substructure seen in the F-ring and the ringlets in the C-ring. We show that Saturn's narrow ringlets have a substructure determined by three-body resonances with Saturn's ringmoons and the sun. We believe such resonances have important implications to satellite formation. 17 refs., 1 fig., 1 tab

  13. Preparation of 90Sr-90Y generator

    International Nuclear Information System (INIS)

    Jin Xiaohai; Yu Haibin; Zhang Jinming; Zhang Peixin; Lin Qiongfang

    1990-01-01

    In recent years, 90 Y has been considered as one of the best radionuclides for tumor radioimmunotherapy when chelated to tumor-associated antibodies. This evaluation is based on the superior properties of this radionuclide (suitable half-life, pure β-ray emitter of intermediate energy, stable daughters, and suitable chemical properties) and because it is available as a radionuclide generator product by decay of its 28a parent 90 Sr. The experimental conditions of 90 Sr- 90 Y generator are described. The elution efficiency of 90 Sr- 90 Y generator reaches 98%. One of the most important problems is the 90 Sr contamination breakthrough from the generator. The level of 90 Sr contamination must be controlled to the clinical standard. The cation exchange resin 732 (100-150 mesh) was successfully used for the separation of 90 Y from 90 Sr. The method used by the authors provides a 90 Y-HAc solution which is very simple and safe for administration to the patients. 90 Y was separated from 90 Sr almost completely, the level of the 90 Sr contamination per 740 MBq 90 Y product was only 0.74 kBq. However the toxicity of 90 Sr is extremely high, the human life-time permissible dose is 74 kBq, then 740 MBq of 90 Y is allowed to be administrated to a patient for 50-100 times

  14. Chernobyl 90Sr in bilberries from Poland

    International Nuclear Information System (INIS)

    Mietelski, J.W.; Vajda, N.

    1997-01-01

    As part of a detailed survey on the contamination of Polish forests 90 Sr activity concentrations were determined in bilberries. Elevated 90 Sr levels were found in several samples from north-eastern Poland. The calculated maximum 90 Sr surface contamination was 2 kBq*m -2 . The correlation between 90 Sr and 137 Cs concentrations in bilberries was good for two sets of samples originating from two geographical areas of Poland indicating the local differences in radionuclide depositions from Chernobyl fallout. (author)

  15. Experiences with the determination of Sr-89 and Sr-90 using fast methods; Erfahrungen bei der Bestimmung von {sup 89}Sr und {sup 90}Sr mittels Schnellmethoden

    Energy Technology Data Exchange (ETDEWEB)

    Kowalik, C.; Fueger, J. [Thueringer Landesanstalt fuer Umwelt und Geologie, Jena (Germany). Landesmessstelle fuer Umweltradioaktivaet

    2014-01-20

    Quick methods of the measurement of {sup 89}Sr and {sup 90}Sr have a great importance in the supervision of the environmental radioactivity. It is necessary to receive in short time dependable analytical data to be able to carry out suitable assessments or to give recommendations. The aim of the investigations was to be guaranteed the demands for these methods (test preparation, measurement and evaluation). The use of the solid phase extraction by means of commercial Sr Resin trademark columns (4.4' (5')-Di-tert-butylcyclohexanol-18-kronen-6-aether) (Triskem) to the radiochemical separation of the Sr isotopes was suitable. The measurements occurred to the FHT 770 T12 - Multi Low Level Alpha/Beta Sample Counter (Thermo Scientific). The results contain the summary activities of all available Sr isotopes, as for example {sup 89}Sr and {sup 90}Sr. The calculations of the single activities occur about the mathematical algorithm of the linear development on the basis of the works of G. Kanisch. The first results show, this method is suitable for the analysis of {sup 89}Sr and {sup 90}Sr and is used therefore in future in Thuringia.

  16. Evaluation of tableting and tablet properties of Kollidon SR: the influence of moisture and mixtures with theophylline monohydrate.

    Science.gov (United States)

    Hauschild, Karsten; Picker-Freyer, Katharina M

    2006-02-01

    The aim of the study was firstly to investigate the influence of moisture on the tableting and tablet properties of Kollidon SR and secondly to investigate the influence of theophylline monohydrate on the tableting behavior and tablet properties produced from binary mixtures with Kollidon SR. In comparison to Kollidon SR, microcrystalline cellulose (MCC) was used. The glass transition temperature (Tg) of the powder over the whole range of RH (0-90%), and in addition, the Tg of tablets of Kollidon SR were measured. Densities and flowability of the powders were analyzed. The tablets were produced at five different maximum relative densities (rho(rel), max) on an instrumented eccentric tableting machine. They were produced at three different relative humidities (RH), 30%, 45%, and 60% RH for the pure substances and binary mixtures with different ratios of drug and excipient were tableted at 45% RH. The tableting properties were analyzed by 3D modeling, force-displacement profiles, and compactibility plots. First, the Tg of the powder decreased with increasing RH and the Tg of the tablet was 4-8 K lower than the powder. The predominant deformation of Kollidon SR is plastic deformation and Kollidon SR showed a higher compactibility than MCC. The parameters of the 3D model showed an extreme change between 45 and 60% RH, and at higher RH more and more particles deformed elastically. This was confirmed by analysis of force-displacement profiles. At 60% RH, the radial tensile strength of the Kollidon SR tablets was half of the radial tensile strength at 45% RH. The reason is a higher relative energy of plastic deformation than for MCC. This results in a better utilization of the energy to deform the powder into a tablet and the exceeding of the glass transition temperature at higher RH. In conclusion, at 60% RH at the same rho(rel, max), tableting and tablet properties of Kollidon SR are extremely changed since plasticity is significantly higher. In the second part of the

  17. MAGNETS FOR A MUON STORAGE RING

    International Nuclear Information System (INIS)

    PARKER, B.; ANERELLA, M.; GHOSH, A.; GUPTA, R.; HARRISON, M.; SCHMALZLE, J.; SONDERICKER, J.; WILLEN, E.

    2002-01-01

    We present a new racetrack coil magnet design, with an open midplane gap, that keeps decay particles in a neutrino factory muon storage ring from directly hitting superconducting coils. The structure is very compact because coil ends overlap middle sections top and bottom for skew focusing optics. A large racetrack coil bend radius allows ''react and wind'' magnet technology to be used for brittle Nb 3 Sn superconductors. We describe two versions: Design-A, a magnet presently under construction and Design-B, a further iterated concept that achieves the higher magnetic field quality specified in the neutrino factory feasibility Study-II report. For Design-B reverse polarity and identical end design of consecutive long and short coils offers theoretically perfect magnet end field error cancellation. These designs avoid the dead space penalty from coil ends and interconnect regions (a large fraction in machines with short length but large aperture magnets) and provide continuous bending or focusing without interruption. The coil support structure and cryostat are carefully optimized

  18. 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.

  19. Design of a compact synchrotron light source for medical applications at NIRS

    International Nuclear Information System (INIS)

    Torikoshi, M.; Endo, M.; Kumada, M.; Noda, K.; Yamada, S.; Kawachi, K.

    1998-01-01

    A synchrotron light source dedicated to medical applications is required to be compact for installation in limited spaces at hospitals. The NIRS storage ring, with a circumference of 44.8 m, is designed to accelerate electrons up to 1.8 GeV and to store a beam of 400 mA. The ring is composed of superconducting bending magnets for downsizing. A beam of 300 MeV is injected into the ring from a microtron operated at an L-band RF frequency. There are two superconducting multipole wigglers with nine poles and a maximum field of 8 T, which can produce a photon flux of about 1.4 x 10 13 photons s -1 mrad -1 (0.1% bandwidth) -1 at 33 keV used for coronary angiography

  20. Noise Source Identification of a Ring-Plate Cycloid Reducer Based on Coherence Analysis

    Directory of Open Access Journals (Sweden)

    Bing Yang

    2013-01-01

    Full Text Available A ring-plate-type cycloid speed reducer is one of the most important reducers owing to its low volume, compactness, smooth and high performance, and high reliability. The vibration and noise tests of the reducer prototype are completed using the HEAD acoustics multichannel noise test and analysis system. The characteristics of the vibration and noise are obtained based on coherence analysis and the noise sources are identified. The conclusions provide the bases for further noise research and control of the ring-plate-type cycloid reducer.

  1. Effect of Wood Aging on Wine Mineral Composition and 87Sr/86Sr Isotopic Ratio.

    Science.gov (United States)

    Kaya, Ayse D; Bruno de Sousa, Raúl; Curvelo-Garcia, António S; Ricardo-da-Silva, Jorge M; Catarino, Sofia

    2017-06-14

    The evolution of mineral composition and wine strontium isotopic ratio 87 Sr/ 86 Sr (Sr IR) during wood aging were investigated. A red wine was aged in stainless steel tanks with French oak staves (Quercus sessiliflora Salisb.), with three industrial scale replicates. Sampling was carried out after 30, 60, and 90 days of aging, and the wines were evaluated in terms of general analysis, phenolic composition, total polysaccharides, multielement composition, and Sr IR. Li, Be, Mg, Al, Sc, Ti, V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Mo, Sb, Cs, Ba, Pr, Nd, Sm, Eu, Dy, Ho, Er, Yb, Lu, Tl, and Pb elements and 87 Sr/ 86 Sr were determined by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and Na, K, Ca, and Fe by flame atomic absorption spectrometry (FAAS). Two-way ANOVA was applied to assess wood aging and time effect on Sr IR and mineral composition. Wood aging resulted in significantly higher concentrations of Mg, V, Co, Ni, and Sr. At the end of the aging period, wine exhibited statistically identical Sr IR compared to control. Study suggests that wood aging does not affect 87 Sr/ 86 Sr, not precluding the use of this parameter for wine traceability purposes.

  2. Atomic layer deposited ZrO2 nanofilm on Mg-Sr alloy for enhanced corrosion resistance and biocompatibility.

    Science.gov (United States)

    Yang, Qiuyue; Yuan, Wei; Liu, Xiangmei; Zheng, Yufeng; Cui, Zhenduo; Yang, Xianjin; Pan, Haobo; Wu, Shuilin

    2017-08-01

    The biodegradability and good mechanical property of magnesium alloys make them potential biomedical materials. However, their rapid corrosion rate in the human body's environment impairs these advantages and limits their clinical use. In this work, a compact zirconia (ZrO 2 ) nanofilm was fabricated on the surface of a magnesium-strontium (Mg-Sr) alloy by the atomic layer deposition (ALD) method, which can regulate the thickness of the film precisely and thus also control the corrosion rate. Corrosion tests reveal that the ZrO 2 film can effectively reduce the corrosion rate of Mg-Sr alloys that is closely related to the thickness of the film. The cell culture test shows that this kind of ZrO 2 film can also enhance the activity and adhesion of osteoblasts on the surfaces of Mg-Sr alloys. The significance of the current work is to develop a zirconia nanofilm on biomedical MgSr alloy with controllable thickness precisely through atomic layer deposition technique. By adjusting the thickness of nanofilm, the corrosion rate of Mg-Sr alloy can be modulated, thereafter, the degradation rate of Mg-based alloys can be controlled precisely according to actual clinical requirement. In addition, this zirconia nanofilm modified Mg-Sr alloys show excellent biocompatibility than the bare samples. Hence, this work provides a new surface strategy to control the degradation rate while improving the biocompatibility of substrates. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Formation of a compact torus using a toroidal plasma gun

    International Nuclear Information System (INIS)

    Levine, M.A.; Pincosy, P.A.

    1981-01-01

    Myers, Levine and Pincosy earlier reported results using a toroidal plasma gun. The device differs from the usual coaxial plasma gun in the use of a strong toroidal bias current for enhanced efficiency, a pair of disk-like accelerating electrodes for reduced viscosity and a fast pulsed toroidal gas valve for more effective use of the injected gas sample. In addition, a technique is used for generating a toroidal current in the plasma ring. The combination offers an opportunity to deliver a plasma with a large amount of energy and to vary the density and relative toroidal and poloidal magnetic field intensities over a range of values. It is the purpose of this paper to report further experimental results, to project the gun's applications to the formation of a compact torus, and to propose a simple modification of the present apparatus as a test

  4. Self-compacting concrete (SCC)

    DEFF Research Database (Denmark)

    Geiker, Mette Rica

    2008-01-01

    In many aspects Self-Compacting Concrete (SCC, “Self-Consolidating Concrete” in North America) can be considered the concrete of the future. SCC is a family of tailored concretes with special engineered properties in the fresh state. SCC flows into the formwork and around even complicated...... reinforcement arrangements under its own weight. Thus, SCC is not vibrated like conventional concrete. This drastically improves the working environment during construction, the productivity, and potentially improves the homogeneity and quality of the concrete. In addition SCC provides larger architectural...

  5. Portable compact multifunction IR calibrator

    International Nuclear Information System (INIS)

    Wyatt, C.L.; Jacobsen, L.; Steed, A.

    1988-01-01

    A compact portable multifunction calibrator designed for future sensor systems is described which enables a linearity calibration for all detectors simultaneously using a near small-area source, a high-resolution mapping of the focal plane with 10 microrad setability and with a blur of less than 100 microrad, system spectral response calibration (radiometer) using a Michelson interferometer source, relative spectral response (spectrometer) using high-temperature external commercial blackbody simulators, and an absolute calibration using an internal low-temperature extended-area source. 5 references

  6. Thermal evolution of compact stars

    International Nuclear Information System (INIS)

    Schaab, C.; Glendenning, N.K.

    1996-01-01

    A collection of modern, field-theoretical equations of state is applied to the investigation of cooling properties of compact stars. These comprise neutron stars as well as hypothetical strange-matter stars, made up of absolutely stable 3-flavor strange-quark matter. Various uncertainties in the behavior of matter at supernuclear densities, e.g., hyperonic degrees of freedom, behavior of coupling strengths in matter, pion and meson condensation, superfluidity, transition to quark matter, absolute stability of strange-quark matter, and last but not least the many-body technique itself are tested against the body of observed cooling data. (orig.)

  7. Shock compaction of molybdenum powder

    Science.gov (United States)

    Ahrens, T. J.; Kostka, D.; Vreeland, T., Jr.; Schwarz, R. B.; Kasiraj, P.

    1983-01-01

    Shock recovery experiments which were carried out in the 9 to 12 GPa range on 1.4 distension Mo and appear adequate to compact to full density ( 45 (SIGMA)m) powders were examined. The stress levels, however, are below those calculated to be from 100 to approx. 22 GPa which a frictional heating model predicts are required to consolidate approx. 10 to 50 (SIGMA)m particles. The model predicts that powders that have a distension of m=1.6 shock pressures of 14 to 72 GPa are required to consolidate Mo powders in the 50 to 10 (SIGMA)m range.

  8. Porewater chemistry in compacted bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Muurinen, A.; Lehikoinen, J. [VTT Chemical Technology, Espoo (Finland)

    1999-03-01

    In this study, the porewater chemistry in compacted bentonite, considered as an engineered barrier in the repository of spent fuel, has been studied in interaction experiments. Many parameters, like the composition and density of bentonite, composition of the solution, bentonite-to-water ratio (B/W), surrounding conditions and experimental time have been varied in the experiments. At the end of the interaction the equilibrating solution, the porewaters squeezed out of the bentonite samples, and bentonites themselves were analyzed to give information for the interpretation and modelling of the interaction. Equilibrium modelling was performed with the HYDRAQL/CE computer code 33 refs.

  9. Compact inertial confinement multireactor concepts

    International Nuclear Information System (INIS)

    Pendergrass, J.H.

    1985-01-01

    Inertial confinement fusion (ICF) commercial-applications plant-optimum driver pulse repetition rates may exceed reactor pulse-repetition-rate capabilities. Thus, more than one reactor may be required for low-cost production of electric power, process heat, fissionable fuels, etc., in ICF plants. Substantial savings in expensive reactor containment cells and blankets can be realized by placing more than one reactor in a cell and by surrounding more than one reactor cavity with a single blanket system. There are also some potential disadvantages associated with close coupling in compact multicavity blankets and multireactor cells. Tradeoffs associated with several scenarios have been studied

  10. Storage ring lattice calibration using resonant spin depolarization

    Directory of Open Access Journals (Sweden)

    K. P. Wootton

    2013-07-01

    Full Text Available This paper presents measurements of the GeV-scale electron beam energy for the storage rings at the synchrotron light source facilities Australian Synchrotron (AS and SPEAR3 at SLAC. Resonant spin depolarization was employed in the beam energy measurement, since it is presently the highest precision technique and an uncertainty of order 10^{-6} was achieved at SPEAR3 and AS. Using the resonant depolarization technique, the beam energy was measured at various rf frequencies to measure the linear momentum compaction factor. This measured linear momentum compaction factor was used to evaluate models of the beam trajectory through combined-function bending magnets. The main bending magnets of both lattices are rectangular, horizontally defocusing gradient bending magnets. Four modeling approaches are compared for the beam trajectory through the bending magnet: a circular trajectory, linear and nonlinear hyperbolic cosine trajectories, and numerical evaluation of the trajectory through the measured magnetic field map. Within the uncertainty of the measurement the momentum compaction factor is shown to agree with the numerical model of the trajectory within the bending magnet, and disagree with the hyperbolic cosine approximation.

  11. 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.

  12. 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.

  13. Magnet design for a low-emittance storage ring

    International Nuclear Information System (INIS)

    Johansson, Martin; Anderberg, Bengt; Lindgren, Lars-Johan

    2014-01-01

    The magnet design of the MAX IV 3 GeV storage ring replaces the conventional support girder + discrete magnets scheme of previous third-generation light sources with a compact integrated design having several consecutive magnet elements precision-machined out of a common solid iron block. The MAX IV 3 GeV storage ring, currently under construction, pursues the goal of low electron beam emittance by using a multi-bend achromat magnet lattice, which is realised by having several consecutive magnet elements precision-machined out of a common solid iron block, 2.3–3.4 m long. With this magnet design solution, instead of having 1320 individual magnets, the MAX IV 3 GeV storage ring is built up using 140 integrated ‘magnet block’ units, containing all these magnet elements. Major features of this magnet block design are compactness, vibration stability and that the alignment of magnet elements within each unit is given by the mechanical accuracy of the CNC machining rather than individual field measurement and adjustment. This article presents practical engineering details of implementing this magnet design solution, and mechanical + magnetic field measurement results from the magnet production series. At the time of writing (spring 2014), the production series, which is totally outsourced to industry, is roughly half way through, with mechanical/magnetic QA conforming to specifications. It is the conclusion of the authors that the MAX IV magnet block concept, which has sometimes been described as new or innovative, is from a manufacturing point of view simply a collection of known mature production methods and measurement procedures, which can be executed at fixed cost with a low level of risk

  14. Cosmology on a cosmic ring

    International Nuclear Information System (INIS)

    Niedermann, Florian; Schneider, Robert

    2015-01-01

    We derive the modified Friedmann equations for a generalization of the Dvali-Gabadadze-Porrati (DGP) model in which the brane has one additional compact dimension. The main new feature is the emission of gravitational waves into the bulk. We study two classes of solutions: first, if the compact dimension is stabilized, the waves vanish and one exactly recovers DGP cosmology. However, a stabilization by means of physical matter is not possible for a tension-dominated brane, thus implying a late time modification of 4D cosmology different from DGP. Second, for a freely expanding compact direction, we find exact attractor solutions with zero 4D Hubble parameter despite the presence of a 4D cosmological constant. The model hence constitutes an explicit example of dynamical degravitation at the full nonlinear level. Without stabilization, however, there is no 4D regime and the model is ruled out observationally, as we demonstrate explicitly by comparing to supernova data

  15. 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)

  16. 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

  17. Spectrometers for compact neutron sources

    Science.gov (United States)

    Voigt, J.; Böhm, S.; Dabruck, J. P.; Rücker, U.; Gutberlet, T.; Brückel, T.

    2018-03-01

    We discuss the potential for neutron spectrometers at novel accelerator driven compact neutron sources. Such a High Brilliance Source (HBS) relies on low energy nuclear reactions, which enable cryogenic moderators in very close proximity to the target and neutron optics at comparably short distances from the moderator compared to existing sources. While the first effect aims at increasing the phase space density of a moderator, the second allows the extraction of a large phase space volume, which is typically requested for spectrometer applications. We find that competitive spectrometers can be realized if (a) the neutron production rate can be synchronized with the experiment repetition rate and (b) the emission characteristics of the moderator can be matched to the phase space requirements of the experiment. MCNP simulations for protons or deuterons on a Beryllium target with a suitable target/moderator design yield a source brightness, from which we calculate the sample fluxes by phase space considerations for different types of spectrometers. These match closely the figures of todays spectrometers at medium flux sources. Hence we conclude that compact neutron sources might be a viable option for next generation neutron sources.

  18. Manufacturability of compact synchrotron mirrors

    Science.gov (United States)

    Douglas, Gary M.

    1997-11-01

    While many of the government funded research communities over the years have put their faith and money into increasingly larger synchrotrons, such as Spring8 in Japan, and the APS in the United States, a viable market appears to exist for smaller scale, research and commercial grade, compact synchrotrons. These smaller, and less expensive machines, provide the research and industrial communities with synchrotron radiation beamline access at a portion of the cost of their larger and more powerful counterparts. A compact synchrotron, such as the Aurora-2D, designed and built by Sumitomo Heavy Industries, Ltd. of japan (SHI), is a small footprint synchrotron capable of sustaining 20 beamlines. Coupled with a Microtron injector, with 150 MeV of injection energy, an entire facility fits within a 27 meter [88.5 ft] square floorplan. The system, controlled by 2 personal computers, is capable of producing 700 MeV electron energy and 300 mA stored current. Recently, an Aurora-2D synchrotron was purchased from SHI by the University of Hiroshima. The Rocketdyne Albuquerque Operations Beamline Optics Group was approached by SHI with a request to supply a group of 16 beamline mirrors for this machine. These mirrors were sufficient to supply 3 beamlines for the Hiroshima machine. This paper will address engineering issues which arose during the design and manufacturing of these mirrors.

  19. Compact Visualisation of Video Summaries

    Directory of Open Access Journals (Sweden)

    Janko Ćalić

    2007-01-01

    Full Text Available This paper presents a system for compact and intuitive video summarisation aimed at both high-end professional production environments and small-screen portable devices. To represent large amounts of information in the form of a video key-frame summary, this paper studies the narrative grammar of comics, and using its universal and intuitive rules, lays out visual summaries in an efficient and user-centered way. In addition, the system exploits visual attention modelling and rapid serial visual presentation to generate highly compact summaries on mobile devices. A robust real-time algorithm for key-frame extraction is presented. The system ranks importance of key-frame sizes in the final layout by balancing the dominant visual representability and discovery of unanticipated content utilising a specific cost function and an unsupervised robust spectral clustering technique. A final layout is created using an optimisation algorithm based on dynamic programming. Algorithm efficiency and robustness are demonstrated by comparing the results with a manually labelled ground truth and with optimal panelling solutions.

  20. Compact heat exchanger for fluids

    International Nuclear Information System (INIS)

    Marchal, P.A.H.

    1975-01-01

    The invention concerns a welded heat exchanger with two or more fluids which can be used counter current. The principle of the apparatus allows the use of rolled welded concentric metal strips as well as spiral rolled metal strips. The ring sheets are kept apart either by their rigidity due to the cylindrical shape or by deformations in the sheets themselves or yet again by spacers or chequered and/or perforated sheets forming for instance corrugated spacers, the end sheet being thick enough to take the pressure strain [fr

  1. Review of SR 97 performance assessment

    International Nuclear Information System (INIS)

    Glynn, P.D.

    2000-01-01

    This review has identified many technical problems in the SR 97 performance assessment. The general impression of this reviewer is that SKB has been disingenuous in its performance assessment effort. It has not cited important differences of opinion with its own views. Furthermore, there are many inconsistencies in the SR 97 report that all together leave the impression that there are many more uncertainties in the SR 97 performance assessment than SKB would perhaps care to admit. Additionally, despite SKB's statements to the contrary, many of the analyses conducted for the SR 97 performance assessment can be clearly shown not to have been based on 'conservative' assumptions. Finally, SKB has made little effort to consider possible coupling effects between their different scenarios in SR 97. This is a serious flaw in the SR 97 performance assessment. The comments in this review should not be taken to imply that the KBS-3 nuclear waste disposal method will not be able to meet the safety and radiation protection requirements which SKI and SSI have specified in recent years. Instead, my conclusion is simply that the SR 97 performance assessment of the KBS-3 method would have been more believable had it been based on a forthright and comprehensive discussion of facts, uncertainties and opinions, and on a more conservative choice of assumptions. As it stands, the SR 97 performance assessment is not very credible

  2. Surface characterization, in vitro and in vivo biocompatibility of Mg-0.3Sr-0.3Ca for temporary cardiovascular implant

    Energy Technology Data Exchange (ETDEWEB)

    Bornapour, M., E-mail: mandana.bornapour@mail.mcgill.ca [Light Metals and Advanced Magnesium Materials, Mining and Materials Engineering, McGill University, Montreal, Qc, H3A 0C5 (Canada); Biointerface Lab, Mining and Materials Engineering, McGill University, Montreal, Qc H3A 0C5 (Canada); Mahjoubi, H. [Biointerface Lab, Mining and Materials Engineering, McGill University, Montreal, Qc H3A 0C5 (Canada); Vali, H. [Department of Anatomy and Cell Biology, McGill University, Montreal, Qc, H3A 0C7 (Canada); Shum-Tim, D. [Department of Cardiac Surgery and Surgical Research, McGill University, Montreal, Qc H3G 1A1 (Canada); Cerruti, M. [Biointerface Lab, Mining and Materials Engineering, McGill University, Montreal, Qc H3A 0C5 (Canada); Pekguleryuz, M. [Light Metals and Advanced Magnesium Materials, Mining and Materials Engineering, McGill University, Montreal, Qc, H3A 0C5 (Canada)

    2016-10-01

    Magnesium-based alloys are attractive candidate materials for medical applications. Our earlier work showed that the ternary Mg-0.3Sr-0.3Ca alloy exhibits slower degradation rates than both binary Mg-Sr and Mg-Ca alloys. The ternary alloy immersed in simulated body fluid (SBF) forms a compact surface layer of corrosion products that we hypothesized to be a Sr-substituted hydroxyapatite (HA). The main objectives of the current work are to understand the bio-degradation mechanism of Mg-0.3Sr-0.3Ca, to identify the exact nature of its protective layer and to evaluate the in vitro and in vivo biocompatibility of the alloy for cardiovascular applications. To better simulate the physiological environment, the alloy was immersed in SBF which was daily refreshed. Raman spectroscopy and X-Ray photoelectron spectroscopy (XPS) confirmed the formation of a thin, Sr-substituted HA layer at the interface between the alloy and the corrosion products. In vitro biocompatibility evaluated via indirect cytotoxicity assays using HUVECs showed no toxicity effect and ions extracted from Mg-0.3Sr-0.3Ca in fact increased the viability of HUVECs after one week. In vivo tests were performed by implanting a tubular Mg-0.3Sr-0.3Ca stent along with a WE43 control stent into the right and left femoral artery of a dog. Post implantation and histological analyses showed no thrombosis in the artery with Mg-0.3Sr-0.3Ca stent after 5 weeks of implantation while the artery implanted with WE43 stent was extensively occluded and thrombosed. Microscopic observation of the Mg-0.3Sr-0.3Ca implant-tissue interface confirmed the in situ formation of Sr-substituted HA on the surface during in vivo test. These results show that the interfacial layer protects the surface of the Mg-0.3Sr-0.3Ca alloy both in vitro and in vivo, and is the key factor in the bio-corrosion resistance of the alloy. - Highlights: • The surface active elements of Sr and Ca alter the corrosion of Mg alloy in SBF • Sr

  3. Surface characterization, in vitro and in vivo biocompatibility of Mg-0.3Sr-0.3Ca for temporary cardiovascular implant

    International Nuclear Information System (INIS)

    Bornapour, M.; Mahjoubi, H.; Vali, H.; Shum-Tim, D.; Cerruti, M.; Pekguleryuz, M.

    2016-01-01

    Magnesium-based alloys are attractive candidate materials for medical applications. Our earlier work showed that the ternary Mg-0.3Sr-0.3Ca alloy exhibits slower degradation rates than both binary Mg-Sr and Mg-Ca alloys. The ternary alloy immersed in simulated body fluid (SBF) forms a compact surface layer of corrosion products that we hypothesized to be a Sr-substituted hydroxyapatite (HA). The main objectives of the current work are to understand the bio-degradation mechanism of Mg-0.3Sr-0.3Ca, to identify the exact nature of its protective layer and to evaluate the in vitro and in vivo biocompatibility of the alloy for cardiovascular applications. To better simulate the physiological environment, the alloy was immersed in SBF which was daily refreshed. Raman spectroscopy and X-Ray photoelectron spectroscopy (XPS) confirmed the formation of a thin, Sr-substituted HA layer at the interface between the alloy and the corrosion products. In vitro biocompatibility evaluated via indirect cytotoxicity assays using HUVECs showed no toxicity effect and ions extracted from Mg-0.3Sr-0.3Ca in fact increased the viability of HUVECs after one week. In vivo tests were performed by implanting a tubular Mg-0.3Sr-0.3Ca stent along with a WE43 control stent into the right and left femoral artery of a dog. Post implantation and histological analyses showed no thrombosis in the artery with Mg-0.3Sr-0.3Ca stent after 5 weeks of implantation while the artery implanted with WE43 stent was extensively occluded and thrombosed. Microscopic observation of the Mg-0.3Sr-0.3Ca implant-tissue interface confirmed the in situ formation of Sr-substituted HA on the surface during in vivo test. These results show that the interfacial layer protects the surface of the Mg-0.3Sr-0.3Ca alloy both in vitro and in vivo, and is the key factor in the bio-corrosion resistance of the alloy. - Highlights: • The surface active elements of Sr and Ca alter the corrosion of Mg alloy in SBF • Sr

  4. Design of a lattice for JAERI storage ring (JSR)

    International Nuclear Information System (INIS)

    Harada, Shunji; Yokomizo, Hideaki; Yanagida, Kenichi

    1990-08-01

    The new 8GeV synchrotron radiation facility (SPring-8) is planned to be constructed in Japan, and our institute (JAERI) are involved in this project with RIKEN. A compact electron storage ring JSR has been constructed in JAERI in order to study various kind of accelerator technologies, to test some devices such as the insertion devices and the beam monitors, and to train young researchers. The ring size is limited by the available space of a linac building, so that the circumference of JSR becomes 20.546 m. However, even in this small ring, one straight section with the length of ∼1.5 m, where the dispersion is free, is provided for the insertion device study. JSR takes Chasman-Green lattice with a superperiodicity of three. JSR is possible not only to suppress the dispersion but also to leave it on the long straight section. An electron beam from a linac is accepted into JSR in any operating modes. (author)

  5. Optics design of Intrabeam Scattering dominated damping rings

    CERN Document Server

    Antoniou, Fanouria; Papaphilippou, Ioannis

    A e+/e- linear collider, the Compact Linear Collider (CLIC) is under design at CERN, aiming to explore the terascale particle physics regime. The collider has been optimized at 3 TeV center of mass energy and targets a luminosity of 1034 cm-2 s-1. In order to achieve this high luminosity, high intensity bunches with ultra low emittances, in all three planes, are required. The generation of ultra low emittance is achieved in the Damping Rings (DR) complex of the collider. The large input beam emittances, especially the ones coming from the positron source, and the requirement of ultra low emittance production in a fast repetition time of 20 ms, imply that the beam damping is done in two stages. Thus, a main-damping ring (DR) and a predamping ring (PDR) are needed, for each particle species. The high bunch brightness gives rise to several collective effects, with Intra-beam scattering (IBS) being the main limitation to the ultra-low emittance. This thesis elaborates the lattice design and non-linear optimizatio...

  6. Prediction for swelling characteristics of compacted bentonite

    International Nuclear Information System (INIS)

    Komine, H.; Ogata, N.

    1996-01-01

    Compacted bentonites are attracting greater attention as back-filling (buffer) materials for high-level nuclear waste repositories. For this purpose, it is very important to quantitatively evaluate the swelling characteristics of compacted bentonite. New equations for evaluating the relationship between the swelling deformation of compacted bentonite and the distance between two montmorillonite layers are derived. New equations for evaluating the ion concentration of pore water and the specific surface of bentonite, which significantly influence the swelling characteristics of compacted bentonite, are proposed. Furthermore, a prediction method for the swelling characteristics of compacted bentonite is presented by combining the new equations with the well-known theoretical equations of repulsive and attractive forces between two montmorillonite layers. The applicability of this method was investigated by comparing the predicted results with laboratory test results on the swelling deformation and swelling pressure of compacted bentonites. (author) 31 refs., 8 tabs., 12 figs

  7. Pure subrings of the rings

    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.

  8. 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

  9. Ring wormholes via duality rotations

    Directory of Open Access Journals (Sweden)

    Gary W. Gibbons

    2016-09-01

    Full Text Available We apply duality rotations and complex transformations to the Schwarzschild metric to obtain wormhole geometries with two asymptotically flat regions connected by a throat. In the simplest case these are the well-known wormholes supported by phantom scalar field. Further duality rotations remove the scalar field to yield less well known vacuum metrics of the oblate Zipoy–Voorhees–Weyl class, which describe ring wormholes. The ring encircles the wormhole throat and can have any radius, whereas its tension is always negative and should be less than −c4/4G. If the tension reaches the maximal value, the geometry becomes exactly flat, but the topology remains non-trivial and corresponds to two copies of Minkowski space glued together along the disk encircled by the ring. The geodesics are straight lines, and those which traverse the ring get to the other universe. The ring therefore literally produces a hole in space. Such wormholes could perhaps be created by negative energies concentrated in toroidal volumes, for example by vacuum fluctuations.

  10. HYPERAUTOFLUORESCENT RING IN AUTOIMMUNE RETINOPATHY

    Science.gov (United States)

    LIMA, LUIZ H.; GREENBERG, JONATHAN P.; GREENSTEIN, VIVIENNE C.; SMITH, R. THEODORE; SALLUM, JULIANA M. F.; THIRKILL, CHARLES; YANNUZZI, LAWRENCE A.; TSANG, STEPHEN H.

    2015-01-01

    Purpose To report the presence of a hyperautofluorescent ring and corresponding spectral-domain optical coherence tomography (SD-OCT) features seen in patients with autoimmune retinopathy. Methods All eyes were evaluated by funduscopic examination, full-fleld electroretinography, fundus autofluorescence, and SD-OCT. Further confirmation of the diagnosis was obtained with immunoblot and immunohistochemistry testing of the patient’s serum. Humphrey visual fields and microperimetry were also performed. Results Funduscopic examination showed atrophic retinal pigment epithelium (RPE) associated with retinal artery narrowing but without pigment deposits. The scotopic and photopic full-field electroretinograms were nondetectable in three patients and showed a cone–rod pattern of dysfunction in one patient. Fundus autofluorescence revealed a hyperautofluorescent ring in the parafoveal region, and the corresponding SD-OCT demonstrated loss of the photoreceptor inner segment–outer segment junction with thinning of the outer nuclear layer from the region of the hyperautofluorescent ring toward the retinal periphery. The retinal layers were generally intact within the hyperautofluorescent ring, although the inner segment–outer segment junction was disrupted, and the outer nuclear layer and photoreceptor outer segment layer were thinned. Conclusion This case series revealed the structure of the hyperautofluorescent ring in autoimmune retinopathy using SD-OCT. Fundus autofluorescence and SD-OCT may aid in the diagnosis of autoimmune retinopathy and may serve as a tool to monitor its progression. PMID:22218149

  11. Noise Source Identification of a Ring-Plate Cycloid Reducer Based on Coherence Analysis

    OpenAIRE

    Yang, Bing; Liu, Yan

    2013-01-01

    A ring-plate-type cycloid speed reducer is one of the most important reducers owing to its low volume, compactness, smooth and high performance, and high reliability. The vibration and noise tests of the reducer prototype are completed using the HEAD acoustics multichannel noise test and analysis system. The characteristics of the vibration and noise are obtained based on coherence analysis and the noise sources are identified. The conclusions provide the bases for further noise research and ...

  12. The Future Concrete: Self-Compacting Concrete

    Directory of Open Access Journals (Sweden)

    Liana Iureş

    2010-01-01

    Full Text Available The paper presents the characteristics of the self-compacting concretes, their advantages and disadvantages when they are used in buildings. Due to its properties and composition, the self-compacting concrete is described here as being one of the future friendly enviromental material for buildings. Tests concerning to obtaining a self-compacting concrete, together with the specific fresh concrete properties tests, are described.

  13. Starbursts in Blue compact dwarf galaxies

    International Nuclear Information System (INIS)

    Thuan, T.X.

    1987-01-01

    We summarize all the arguments for a bursting mode of star formation in blue compact dwarf galaxies. We show in particular how spectral synthesis of far ultraviolet spectra of Blue compact dwarf galaxy constitutes a powerful way for studying the star formation history in these galaxies. Blue compact dwarf galaxy luminosity functions show jumps and discontinuities. These jumps act like fossil records of the star-forming bursts, helping us to count and date the bursts

  14. Effect of slash on forwarder soil compaction

    Science.gov (United States)

    Timothy P. McDonald; Fernando Seixas

    1997-01-01

    A study of the effect of slash on forwarder soil compaction was carried out. The level of soil compaction at two soil moisture contents, three slash densities (0, 10, and 20 kg/m2), and two levels of traffic (one and five passes) were measured. Results indicated that, on dry, loamy sand soils, the presence of slash did not decrease soil compaction after one forwarder...

  15. The Future Concrete: Self-Compacting Concrete

    OpenAIRE

    Iureş, Liana; Bob, Corneliu

    2010-01-01

    The paper presents the characteristics of the self-compacting concretes, their advantages and disadvantages when they are used in buildings. Due to its properties and composition, the self-compacting concrete is described here as being one of the future friendly enviromental material for buildings. Tests concerning to obtaining a self-compacting concrete, together with the specific fresh concrete properties tests, are described.

  16. Compact approach to fusion power reactors

    International Nuclear Information System (INIS)

    Hagenson, R.L.; Krakowski, R.A.; Bathke, C.G.; Miller, R.L.

    1984-01-01

    The potential of the Reversed-Field Pinch (RFP) for development into an efficient, compact, copper-coil fusion reactor has been quantified by comprehensive parametric tradeoff studies. These compact systems promise to be competitive in size, power density, and cost to alternative energy sources. Conceptual engineering designs that largely substantiate these promising results have since been completed. This 1000-MWe(net) design is described along with a detailed rationale and physics/technology assessment for the compact approach to fusion

  17. Thermodynamic Modeling of Sr/TRU Removal

    International Nuclear Information System (INIS)

    Felmy, A.R.

    2000-01-01

    This report summarizes the development and application of a thermodynamic modeling capability designed to treat the Envelope C wastes containing organic complexants. A complete description of the model development is presented. In addition, the model was utilized to help gain insight into the chemical processes responsible for the observed levels of Sr, TRU, Fe, and Cr removal from the diluted feed from tank 241-AN-107 which had been treated with Sr and permanganate. Modeling results are presented for Sr, Nd(III)/Eu(III), Fe, Cr, Mn, and the major electrolyte components of the waste (i.e. NO 3 , NO 2 , F,...). On an overall basis the added Sr is predicted to precipitate as SrCO 3 (c) and the MnO 4 - reduced by the NO 2 - and precipitated as a Mn oxide. These effects result in only minor changes to the bulk electrolyte chemistry, specifically, decreases in NO 2 - and CO 3 2- , and increases in NO 3 - and OH - . All of these predictions are in agreement with the experimental observations. The modeling also indicates that the majority of the Sr, TRU's (or Nd(III)/Eu(III)) analogs, and Fe are tied up with the organic complexants. The Sr and permanganate additions are not predicted to effect these chelate complexes significantly owing to the precipitation of insoluble Mn oxides or SrCO 3 . These insoluble phases maintain low dissolved concentrations of Mn and Sr which do not affect any of the other components tied up with the complexants. It appears that the removal of the Fe and TRU'S during the treatment process is most likely as a result of adsorption or occlusion on/into the Mn oxides or SrCO 3 , not as direct displacement from the complexants into precipitates. Recommendations are made for further studies that are needed to help resolve these issues

  18. Mirror decay of $^{75}$Sr

    CERN Document Server

    Huikari, J; Algora, A; Cederkäll, J; Courtin, S; Dessagne, P; Fraile-Prieto, L M; Franchoo, S; Fynbo, H O U; Huang Wan Xia; Jokinen, A; Knipper, A; Maréchal, F; Miehé, C; Nácher, E; Peräjärvi, K; Poirier, E; Weissman, L; Äystö, J

    2003-01-01

    The beta -decay of /sup 75/Sr to its mirror nucleus /sup 75/Rb was studied at the ISOLDE PSB facility at CERN by means of beta -delayed gamma and proton spectroscopy. The decay Q-value and beta -delayed gamma intensity were measured for the first time. These results, 10.60+or-0.22 MeV and 4.5/sub -0.7//sup +1.9/%, together with accurate measurements of the beta -decay half-life and beta -delayed proton branching ratio yielded the Gamow-Teller strength 0.35+or-0.05 for the mirror transition. Implications of the results on studies of deformation effects and on the path of the rapid proton capture process are discussed. (24 refs).

  19. Compactly supported Wannier functions and algebraic K -theory

    Science.gov (United States)

    Read, N.

    2017-03-01

    In a tight-binding lattice model with n orbitals (single-particle states) per site, Wannier functions are n -component vector functions of position that fall off rapidly away from some location, and such that a set of them in some sense span all states in a given energy band or set of bands; compactly supported Wannier functions are such functions that vanish outside a bounded region. They arise not only in band theory, but also in connection with tensor-network states for noninteracting fermion systems, and for flat-band Hamiltonians with strictly short-range hopping matrix elements. In earlier work, it was proved that for general complex band structures (vector bundles) or general complex Hamiltonians—that is, class A in the tenfold classification of Hamiltonians and band structures—a set of compactly supported Wannier functions can span the vector bundle only if the bundle is topologically trivial, in any dimension d of space, even when use of an overcomplete set of such functions is permitted. This implied that, for a free-fermion tensor network state with a nontrivial bundle in class A, any strictly short-range parent Hamiltonian must be gapless. Here, this result is extended to all ten symmetry classes of band structures without additional crystallographic symmetries, with the result that in general the nontrivial bundles that can arise from compactly supported Wannier-type functions are those that may possess, in each of d directions, the nontrivial winding that can occur in the same symmetry class in one dimension, but nothing else. The results are obtained from a very natural usage of algebraic K -theory, based on a ring of polynomials in e±i kx,e±i ky,..., which occur as entries in the Fourier-transformed Wannier functions.

  20. Advances in compact manufacturing for shape and performance controllability of large-scale components-a review

    Science.gov (United States)

    Qin, Fangcheng; Li, Yongtang; Qi, Huiping; Ju, Li

    2017-01-01

    Research on compact manufacturing technology for shape and performance controllability of metallic components can realize the simplification and high-reliability of manufacturing process on the premise of satisfying the requirement of macro/micro-structure. It is not only the key paths in improving performance, saving material and energy, and green manufacturing of components used in major equipments, but also the challenging subjects in frontiers of advanced plastic forming. To provide a novel horizon for the manufacturing in the critical components is significant. Focused on the high-performance large-scale components such as bearing rings, flanges, railway wheels, thick-walled pipes, etc, the conventional processes and their developing situations are summarized. The existing problems including multi-pass heating, wasting material and energy, high cost and high-emission are discussed, and the present study unable to meet the manufacturing in high-quality components is also pointed out. Thus, the new techniques related to casting-rolling compound precise forming of rings, compact manufacturing for duplex-metal composite rings, compact manufacturing for railway wheels, and casting-extruding continuous forming of thick-walled pipes are introduced in detail, respectively. The corresponding research contents, such as casting ring blank, hot ring rolling, near solid-state pressure forming, hot extruding, are elaborated. Some findings in through-thickness microstructure evolution and mechanical properties are also presented. The components produced by the new techniques are mainly characterized by fine and homogeneous grains. Moreover, the possible directions for further development of those techniques are suggested. Finally, the key scientific problems are first proposed. All of these results and conclusions have reference value and guiding significance for the integrated control of shape and performance in advanced compact manufacturing.

  1. Soil compaction and growth of woody plants

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, T.T. [Univ. of California, Berkeley (United States). Dept. of Environmental Science, Policy and Management

    1999-07-01

    Although soil compaction in the field may benefit or inhibit the growth of plants, the harmful effects are much more common. This paper emphasizes the deleterious effects of predominantly high levels of soil compaction on plant growth and yield. High levels of soil compaction are common in heavily used recreation areas, construction sites, urban areas, timber harvesting sites, fruit orchards, agroforestry systems and tree nurseries. Compaction can occur naturally by settling or slumping of soil or may be induced by tillage tools, heavy machinery, pedestrian traffic, trampling by animals and fire. Compaction typically alters soil structure and hydrology by increasing soil bulk density; breaking down soil aggregates; decreasing soil porosity, aeration and infiltration capacity; and by increasing soil strength, water runoff and soil erosion. Appreciable compaction of soil leads to physiological dysfunctions in plants. Often, but not always, reduced water absorption and leaf water deficits develop. Soil compaction also induces changes in the amounts and balances of growth hormones in plants, especially increases in abscisic acid and ethylene. Absorption of the major mineral nutrients is reduced by compaction of both surface soils and subsoils. The rate of photosynthesis of plants growing in very compacted soil is decreased by both stomatal and non-stomatal inhibition. Total photosynthesis is reduced as a result of smaller leaf areas. As soils become increasingly compacted respiration of roots shifts toward an anaerobic state. Severe soil compaction adversely influences regeneration of forest stands by inhibiting seed germination and growth of seedlings, and by inducing seedling mortality. Growth of woody plants beyond the seedling stage and yields of harvestable plant products also are greatly decreased by soil compaction because of the combined effects of high soil strength, decreased infiltration of water and poor soil aeration, all of which lead to a decreased

  2. Peculiarities of powder brittle media compaction

    International Nuclear Information System (INIS)

    Perel'nam, V.E.; Aristarkhov, A.I.

    1981-01-01

    The paper is concerned with theoretical and practical aspects of the compaction process for powders of almost unstrained materials. Consideration from the standpoint of compressible body strain mechanics shows that such porous media may have a certain ''threshold'' density. Ductile characteristics of the porous material compacted up to this extent are identical with properties of compacrat bodies, i.e. there is a theoretically substantiated ban on a possibility of their further compaction without changing the state of the powder particle material. Theoretical conclusions are confirmed by results of experimental studies in compaction of titanium- containing ceramics [ru

  3. Soil compaction and growth of woody plants

    International Nuclear Information System (INIS)

    Kozlowski, T.T.

    1999-01-01

    Although soil compaction in the field may benefit or inhibit the growth of plants, the harmful effects are much more common. This paper emphasizes the deleterious effects of predominantly high levels of soil compaction on plant growth and yield. High levels of soil compaction are common in heavily used recreation areas, construction sites, urban areas, timber harvesting sites, fruit orchards, agroforestry systems and tree nurseries. Compaction can occur naturally by settling or slumping of soil or may be induced by tillage tools, heavy machinery, pedestrian traffic, trampling by animals and fire. Compaction typically alters soil structure and hydrology by increasing soil bulk density; breaking down soil aggregates; decreasing soil porosity, aeration and infiltration capacity; and by increasing soil strength, water runoff and soil erosion. Appreciable compaction of soil leads to physiological dysfunctions in plants. Often, but not always, reduced water absorption and leaf water deficits develop. Soil compaction also induces changes in the amounts and balances of growth hormones in plants, especially increases in abscisic acid and ethylene. Absorption of the major mineral nutrients is reduced by compaction of both surface soils and subsoils. The rate of photosynthesis of plants growing in very compacted soil is decreased by both stomatal and non-stomatal inhibition. Total photosynthesis is reduced as a result of smaller leaf areas. As soils become increasingly compacted respiration of roots shifts toward an anaerobic state. Severe soil compaction adversely influences regeneration of forest stands by inhibiting seed germination and growth of seedlings, and by inducing seedling mortality. Growth of woody plants beyond the seedling stage and yields of harvestable plant products also are greatly decreased by soil compaction because of the combined effects of high soil strength, decreased infiltration of water and poor soil aeration, all of which lead to a decreased

  4. Understanding the apparent diffusivity of Sr-85 ion for MX-80 in different salinity condition at low dry density

    International Nuclear Information System (INIS)

    Ahmad Hasnulhadi Che Kamaruddin

    2012-01-01

    The apparent diffusivity of strontium-85 in the compacted MX-80 bentonite under different salinity conditions and dry densities was conducted were studied from the viewpoint of activation energy. Through in-diffusions experiments the effect of salinity on diffusion behavior of Sr-85 ions can also can be explained. As we know, Sr-90 is by product of the fission materials of nuclear wastes and should be manage properly. Sr-85 is radioactive isotope with the same chemical properties of Sr-90. Adsorption affects only non-steady-state diffusion while at the steady state (e.g., a constant concentration gradient between a constant source and a constant sink), there is no net uptake or release by adsorption, so adsorption has no effect on diffusion (Drever, James I., 1997). The changes in the basal spacing of bentonite as a function of salinity are needed to be observed by the X-ray diffraction method to understand the microstructure changes in diffusion pathways for Sr-85 in MX-80 bentonite. As we know, there could be three potential pathways for radionuclide diffusion in solution-saturated, compacted montmorillonite, i.e., pore water, external surfaces and the internal surface (interlayer spaces) of montmorillonite aggregates (Kozaki et al., 2008). So, it is important to understand the diffusion processes in term of apparent diffusivity of Sr-85 ions in different salinity concentration at low dry density of MX-80. Several parameters are needed in explaining the process such as dry density, activation energy, temperature dependence and concentration of the salinity solutions. (author)

  5. Compact X-ray source based on Compton backscattering

    CERN Document Server

    Bulyak, E V; Zelinsky, A; Karnaukhov, I; Kononenko, S; Lapshin, V G; Mytsykov, A; Telegin, Yu P; Khodyachikh, A; Shcherbakov, A; Molodkin, V; Nemoshkalenko, V; Shpak, A

    2002-01-01

    The feasibility study of an intense X-ray source based on the interaction between the electron beam in a compact storage ring and the laser pulse accumulated in an optical resonator is carried out. We propose to reconstruct the 160 MeV electron storage ring N-100, which was shutdown several years ago. A new magnetic lattice will provide a transverse of electron beam size of approx 35 mu m at the point of electron beam-laser beam interaction. The proposed facility is to generate X-ray beams of intensity approx 2.6x10 sup 1 sup 4 s sup - sup 1 and spectral brightness approx 10 sup 1 sup 2 phot/0.1%bw/s/mm sup 2 /mrad sup 2 in the energy range from 10 keV up to 0.5 MeV. These X-ray beam parameters meet the requirements for most of technological and scientific applications. Besides, we plan to use the new facility for studying the laser cooling effect.

  6. Compact X-ray source based on Compton backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Bulyak, E.; Gladkikh, P.; Zelinsky, A. E-mail: zelinsky@kipt.kharkov.ua; Karnaukhov, I.; Kononenko, S.; Lapshin, V.; Mytsykov, A.; Telegin, Yu.; Khodyachikh, A.; Shcherbakov, A.; Molodkin, V.; Nemoshkalenko, V.; Shpak, A

    2002-07-21

    The feasibility study of an intense X-ray source based on the interaction between the electron beam in a compact storage ring and the laser pulse accumulated in an optical resonator is carried out. We propose to reconstruct the 160 MeV electron storage ring N-100, which was shutdown several years ago. A new magnetic lattice will provide a transverse of electron beam size of {approx}35 {mu}m at the point of electron beam-laser beam interaction. The proposed facility is to generate X-ray beams of intensity {approx}2.6x10{sup 14} s{sup -1} and spectral brightness {approx}10{sup 12} phot/0.1%bw/s/mm{sup 2}/mrad{sup 2} in the energy range from 10 keV up to 0.5 MeV. These X-ray beam parameters meet the requirements for most of technological and scientific applications. Besides, we plan to use the new facility for studying the laser cooling effect.

  7. Development of Stripline Kickers for Low Emittance Rings: Application to the Beam Extraction Kicker for CLIC Damping Rings

    CERN Document Server

    AUTHOR|(SzGeCERN)728476; Toral Fernandez, Fernando

    In the framework of the design study of Future Linear Colliders, the Compact Linear Collider (CLIC) aims for electron-positron collisions with high luminosity at a nominal centre-of-mass energy of 3 TeV. To achieve the luminosity requirements, Pre-Damping Rings (PDRs) and Damping Rings (DRs) are required: they reduce the beam emittance before the beam is accelerated in the main linac. Several injection and extraction systems are needed to inject and extract the beam from the PDRs and DRs. The work of this Thesis consists of the design, fabrication and laboratory tests of the first stripline kicker prototype for beam extraction from the CLIC DRs, although the methodology proposed can be extended to stripline kickers for any low emittance ring. The excellent field homogeneity required, as well as a good transmission of the high voltage pulse through the electrodes, has been achieved by choosing a novel electrode shape. With this new geometry, it has been possible to benefit from all the advantages that the most...

  8. Neodymium-doped Sr5(PO4)3F and Sr5(VO4)3F

    International Nuclear Information System (INIS)

    Corker, D.L.; Nicholls, J.; Loutts, G.B.

    1995-01-01

    Neodymium-doped Sr 5 (PO 4 ) 3 F [neodymium strontium fluoride phosphate, (Nd,Sr) 5 (PO 4 ) 3 F] and neodymium-doped Sr 5 (VO 4 ) 3 F [neodymium strontium fluoride vanadate, (Nd,Sr) 5 (VO 4 ) 3 F] crystallize in space group P6 3 /m and are isostructural with calcium fluorophosphate, Ca 5 (PO 4 ) 3 F. There are two different Sr sites in Sr 5 (XO 4 ) 3 F, denoted Sr(1) and Sr(2). Using single-crystal X-ray diffraction the two structures were refined to R factors of 2.3 and 2.2%, respectively, showing that Nd is present at both Sr sites in (Sr,Nd) 5 (VO 4 ) 3 F but only at the Sr(2) site in (Sr,Nd) 5 (PO 4 ) 3 F. (orig.)

  9. CMB lensing and giant rings

    Energy Technology Data Exchange (ETDEWEB)

    Rathaus, Ben; Itzhaki, Nissan, E-mail: nitzhaki@post.tau.ac.il, E-mail: ben.rathaus@gmail.com [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv University, Ramat-Aviv, 69978 (Israel)

    2012-05-01

    We study the CMB lensing signature of a pre-inationary particle (PIP), assuming it is responsible for the giant rings anomaly that was found recently in the WMAP data. Simulating Planck-like data we find that generically the CMB lensing signal to noise ratio associated with such a PIP is quite small and it would be difficult to cross correlate the temperature giant rings with the CMB lensing signal. However, if the pre-inationary particle is also responsible for the bulk flow measured from the local large scale structure, which happens to point roughly at the same direction as the giant rings, then the CMB lensing signal to noise ratio is fairly significant.

  10. Proton storage ring summer workshop

    International Nuclear Information System (INIS)

    Lawrence, G.P.; Cooper, R.K.

    1977-10-01

    During the week of August 16, 1976 a Workshop was held at the Los Alamos Scientific Laboratory (LASL) on the Proton Storage Ring (PSR) for the Weapons Neutron Research Facility (WNRF). Written contributions were solicited from each of the participants in the Workshop, and the contributions that were received are presented. The papers do not represent polished or necessarily complete work, but rather represent ''first cuts'' at their respective areas. Topics covered include: (1) background information on the storage ring; (2) WNRF design; (3) rf transient during filling; (4) rf capture; (5) beam bunch compression; (6) transverse space charge limits; (7) transverse resistive instability in the PSR; (8) longitudinal resistive instability; (9) synchrotron frequency splitting; (10) E Quintus Unum--off resonance; (11) first harmonic bunching in the storage ring; (12) kicker considerations; (13) beam extraction; (14) ferrite kicker magnets; and (15) E Quintus Unum: a possible ejection scheme

  11. New Main Ring control system

    International Nuclear Information System (INIS)

    Seino, K.; Anderson, L.; Ducar, R.; Franck, A.; Gomilar, J.; Hendricks, B.; Smedinghoff, J.

    1990-03-01

    The Fermilab Main Ring control system has been operational for over sixteen years. Aging and obsolescence of the equipment make the maintenance difficult. Since the advent of the Tevatron, considerable upgrades have been made to the controls of all the Fermilab accelerators except the Main Ring. Modernization of the equipment and standardization of the hardware and software have thus become inevitable. The Tevatron CAMAC serial system has been chosen as a basic foundation in order to make the Main Ring control system compatible with the rest of the accelerator complex. New hardware pieces including intelligent CAMAC modules have been designed to satisfy unique requirements. Fiber optic cable and repeaters have been installed in order to accommodate new channel requirements onto the already saturated communication medium system. 8 refs., 2 figs

  12. Full-scale demonstration of EBS construction technology I. Block, pellet and in-situ compaction method

    International Nuclear Information System (INIS)

    Toguri, Satohito; Asano, Hidekazu; Takao, Hajime; Matsuda, Takeshi; Amemiya, Kiyoshi

    2008-01-01

    (i) Bentonite Block: Applicability of manufacturing technology of buffer material was verified by manufacturing of full scale bentonite ring which consists of one-eight (1/8) dividing block (Outside Diameter (OD): 2.220 mm H: 300 mm). Density characteristic, dimension and scale effect, which were considered the tunnel environment under transportation, were evaluated. Vacuum suction technology was selected as handling technology for the ring. Hoisting characteristic of vacuum suction technology was presented through evaluation of the mechanical property of buffer material, the friction between blocks, etc. by using a full-scale bentonite ring (OD 2.200 mm, H 300 mm). And design of bentonite block and emplacement equipment were presented in consideration of manufacturability of the block, stability of handling and improvement of emplacement efficiency. (ii) Bentonite Pellet Filling: Basic characteristics such as water penetration, swelling and thermal conductivity of various kinds of bentonite pellet were collected by laboratory scale tests. Applicability of pellet filling technology was evaluated by horizontal filling test using a simulated full-scale drift tunnel (OD 2.200 mm, L 6 m) . Filling density, grain size distribution, etc. were also measured. (iii) In-Situ Compaction of Bentonite: Dynamic compaction method (heavy weight fall method) was selected as in-situ compaction technology. Compacting examination which used a full scale disposal pit (OD 2.360 mm) was carried out. Basic specification of compacting equipment and applicability of in-situ compaction technology were presented. Density, density distribution of buffer material and energy acted on the wall of the pit, were also measured. (author)

  13. Tree rings and radiocarbon calibration

    International Nuclear Information System (INIS)

    Barbetti, M.

    1999-01-01

    Only a few kinds of trees in Australia and Southeast Asia are known to have growth rings that are both distinct and annual. Those that do are therefore extremely important to climatic and isotope studies. In western Tasmania, extensive work with Huon pine (Lagarostrobos franklinii) has shown that many living trees are more than 1,000 years old, and that their ring widths are sensitive to temperature, rainfall and cloud cover (Buckley et al. 1997). At the Stanley River there is a forest of living (and recently felled) trees which we have sampled and measured. There are also thousands of subfossil Huon pine logs, buried at depths less than 5 metres in an area of floodplain extending over a distance of more than a kilometre with a width of tens of metres. Some of these logs have been buried for 50,000 years or more, but most of them belong to the period between 15,000 years and the present. In previous expeditions in the 1980s and 1990s, we excavated and sampled about 350 logs (Barbetti et al. 1995; Nanson et al. 1995). By measuring the ring-width patterns, and matching them between logs and living trees, we have constructed a tree-ring dated chronology from 571 BC to AD 1992. We have also built a 4254-ring floating chronology (placed by radiocarbon at ca. 3580 to 7830 years ago), and an earlier 1268-ring chronology (ca. 7,580 to 8,850 years ago). There are many individuals, or pairs of logs which match and together span several centuries, at 9,000 years ago and beyond

  14. Adiabatic compression of ion rings

    International Nuclear Information System (INIS)

    Larrabee, D.A.; Lovelace, R.V.

    1982-01-01

    A study has been made of the compression of collisionless ion rings in an increasing external magnetic field, B/sub e/ = zB/sub e/(t), by numerically implementing a previously developed kinetic theory of ring compression. The theory is general in that there is no limitation on the ring geometry or the compression ratio, lambdaequivalentB/sub e/ (final)/B/sub e/ (initial)> or =1. However, the motion of a single particle in an equilibrium is assumed to be completely characterized by its energy H and canonical angular momentum P/sub theta/ with the absence of a third constant of the motion. The present computational work assumes that plasma currents are negligible, as is appropriate for a low-temperature collisional plasma. For a variety of initial ring geometries and initial distribution functions (having a single value of P/sub theta/), it is found that the parameters for ''fat'', small aspect ratio rings follow general scaling laws over a large range of compression ratios, 1 3 : The ring radius varies as lambda/sup -1/2/; the average single particle energy as lambda/sup 0.72/; the root mean square energy spread as lambda/sup 1.1/; and the total current as lambda/sup 0.79/. The field reversal parameter is found to saturate at values typically between 2 and 3. For large compression ratios the current density is found to ''hollow out''. This hollowing tends to improve the interchange stability of an embedded low β plasma. The implications of these scaling laws for fusion reactor systems are discussed

  15. Computation of integral electron storage ring beam characteristics in the application package DeCA. Version 3.3. A physical model

    International Nuclear Information System (INIS)

    Gladkikh, P.I.; Strelkov, M.A.; Zelinskij, A.Yu.

    1993-01-01

    In calculations and optimization of electron storage ring lattices, aside from solving the problem of particle motion stability in the ring and calculating ring structure functions and betatron tune, it is of great importance to determine the integral characteristics such as momentum compaction factor, chromaticity of the lattice, emittance, energy spread, bunch size, beam lifetime, etc. Knowing them, one is able to determine all most important properties which the beam would have in the storage ring, as well as to work out requirements for physical equipment of the ring. In this respect it is of importance to have a possibility of calculating rapidly all the parameters required. This paper describes convenient algorithms for calculating integral beam characteristics in electron storage rings, which are employed in the application package DeCA

  16. Superconducting proton ring for PETRA

    International Nuclear Information System (INIS)

    Baynham, E.

    1979-01-01

    A powerful new facility for colliding beam physics could be provided by adding a proton storage ring in the range of several hundred GeV to the electron-positron storage ring PETRA at DESY. This can be achieved in an economic way utilizing the PETRA tunnel and taking advantage of the higher magnetic fields of superconducting magnets which would be placed above or below the PETRA magnets. A central field of 4 Tesla in the bending magnets corresponds to a proton energy of 225 GeV. (orig.)

  17. The Cryogenic Storage Ring CSR

    OpenAIRE

    von Hahn, Robert; Becker, Arno; Berg, Felix; Blaum, Klaus; Breitenfeldt, Christian; Fadil, Hisham; Fellenberger, Florian; Froese, Michael; George, Sebastian; Göck, Jürgen; Grieser, Manfred; Grussie, Florian; Guerin, Elisabeth A.; Heber, Oded; Herwig, Philipp

    2016-01-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion a...

  18. Supersymmetric rings in field theory

    International Nuclear Information System (INIS)

    Blanco-Pillado, Jose J.; Redi, Michele

    2006-01-01

    We study the dynamics of BPS string-like objects obtained by lifting monopole and dyon solutions of N = 2 Super-Yang-Mills theory to five dimensions. We present exact traveling wave solutions which preserve half of the supersymmetries. Upon compactification this leads to macroscopic BPS rings in four dimensions in field theory. Due to the fact that the strings effectively move in six dimensions the same procedure can also be used to obtain rings in five dimensions by using the hidden dimension

  19. Damping ring designs and issues

    International Nuclear Information System (INIS)

    Wolski, Andrzej; Decking, Winfried

    2003-01-01

    The luminosity performance of a future linear collider (LC) will depend critically on the performance of the damping rings. The design luminosities of the current LC proposals require rings with very short damping times, large acceptance, low equilibrium emittance and high beam intensity. We discuss the design strategies for lattices achieving the goals of dynamical stability, examine the challenges for alignment and coupling correction, and consider a variety of collective effects that threaten to limit beam quality. We put the design goals in context by referring to the experience of operating facilities, and outline the further research and development that is needed

  20. 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)

  1. (U) Influence of Compaction Model Form on Planar and Cylindrical Compaction Geometries

    Energy Technology Data Exchange (ETDEWEB)

    Fredenburg, David A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carney, Theodore Clayton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fichtl, Christopher Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ramsey, Scott D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-01-05

    The dynamic compaction response of CeO2 is examined within the frameworks of the Ramp and P-a compaction models. Hydrocode calculations simulating the dynamic response of CeO2 at several distinct pressures within the compaction region are investigated in both planar and cylindrically convergent geometries. Findings suggest additional validation of the compaction models is warranted under complex loading configurations.

  2. Experimental studies of compact toroids

    International Nuclear Information System (INIS)

    1991-01-01

    The Berkeley Compact Toroid Experiment (BCTX) device is a plasma device with a Marshall-gun generated, low aspect ratio toroidal plasma. The device is capable of producing spheromak-type discharges and may, with some modification, produce low-aspect ratio tokamak configurations. A unique aspect of this experimenal devie is its large lower hybrid (LH) heating system, which consists of two 450MHz klystron tubes generating 20 megawatts each into a brambilla-type launching structure. Successful operation with one klystron at virtually full power (18 MW) has been accomplished with 110 μs pulse length. A second klystron is currently installed in its socket and magnet but has not been added to the RF drive system. This report describes current activities and accomplishments and describes the anticipated results of next year's activity

  3. Quasistatic evolution of compact toroids

    International Nuclear Information System (INIS)

    Sgro, A.G.; Spencer, R.L.; Lilliequist, C.

    1981-01-01

    Some results are presented of simulations of the post formation evolution of compact toroids. The simulations were performed with a 1-1/2 D transport code. Such a code makes explicit use of the fact that the shapes of the flux surfaces in the plasma change much more slowly than do the profiles of the physical variables across the flux surfaces. Consequently, assuming that the thermodynamic variables are always equilibrated on a flux surface, one may calculate the time evolution of these profiles as a function of a single variable that labels the flux surfaces. Occasionally, during the calculation these profiles are used to invert the equilibrium equation to update the shapes of the flux surfaces. In turn, these shapes imply certain geometric cofficients, such as A = 2 >, which contain the geometric information required by the 1-D equations

  4. Compact RFID Enabled Moisture Sensor

    Directory of Open Access Journals (Sweden)

    U. H. Khan

    2016-09-01

    Full Text Available This research proposes a novel, low-cost RFID tag sensor antenna implemented using commercially available Kodak photo-paper. The aim of this paper is to investigate the possibility of stable, RFID centric communication under varying moisture levels. Variation in the frequency response of the RFID tag in presence of moisture is used to detect different moisture levels. Combination of unique jaw shaped contours and T-matching network is used for impedance matching which results in compact size and minimal ink consumption. Proposed tag is 1.4 × 9.4 cm2 in size and shows optimum results for various moisture levels upto 45% in FCC band with a bore sight read range of 12.1 m.

  5. COMPACTION STUDIES OF TORREFIED WILLOW

    Directory of Open Access Journals (Sweden)

    Michał Rejdak

    2017-01-01

    Full Text Available The article presents the results of studies of torrefied willow (Salix viminalis L. compaction. Densification tests were performed using a hydraulic press with a maximum pressure of 216 MPa. The effect of basic parameters of the briquetting process (pressure and temperature on mechanical parameters of manufactured briquettes were determined. On the basis of the research, it was found that the increase in pressure and temperature of the densification process increases the density and strength of pressed briquettes. The positive effect of temperature is particularly noticeable at lower pressing pressures (36 MPa – 72 MPa. In the case of a temperature of 300 °C, the increase in a pressure from 144 MPa to 216 MPa resulted in the decrease in the density and strength of the briquette. It was also found that the briquettes manufactured at this temperature are characterized by lower density and strength than the briquettes obtained at a temperature of 200 °C.

  6. A compact mobile neutron generator

    International Nuclear Information System (INIS)

    Zhou Changgeng; Li Yan; Hu Yonghong; Lou Benchao; Wu Chunlei

    2007-06-01

    Through fitting the high voltage terminal from introducing overseas and pulse system et al. from oneself developing together, a compact mobile neutron generator is established. The length and weight of this neutron generator are 2 500 mm and less than 1 t, respectively. It can be expediently moved to the location which is required by experimental people. It is consisted of RF ion source, acceleration tube, high voltage generator, focus device, microsecond pulse system, gas leak system, control system, vacuum system and experimental target. It can produce 150 μA continuous deuterium ion beam current, also can produce the pulse deuterium ion beam current. The pulse widths are 10-100 μs and frequencies 10 Hz, 1 000 Hz, 10 000 Hz. The D-T neutron yields of the neutron generator may arrive 1.5 x 10 10 s -1 . The working principle and the structure of the main parts of this neutron generator are described. (authors)

  7. Compact torus compression of microwaves

    International Nuclear Information System (INIS)

    Hewett, D.W.; Langdon, A.B.

    1985-01-01

    The possibility that a compact torus (CT) might be accelerated to large velocities has been suggested by Hartman and Hammer. If this is feasible one application of these moving CTs might be to compress microwaves. The proposed mechanism is that a coaxial vacuum region in front of a CT is prefilled with a number of normal electromagnetic modes on which the CT impinges. A crucial assumption of this proposal is that the CT excludes the microwaves and therefore compresses them. Should the microwaves penetrate the CT, compression efficiency is diminished and significant CT heating results. MFE applications in the same parameters regime have found electromagnetic radiation capable of penetrating, heating, and driving currents. We report here a cursory investigation of rf penetration using a 1-D version of a direct implicit PIC code

  8. Anisotropic models for compact stars

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, S.K.; Dayanandan, Baiju [University of Nizwa, Department of Mathematical and Physical Sciences, College of Arts and Science, Nizwa (Oman); Gupta, Y.K. [Jaypee Institute of Information Technology University, Department of Mathematics, Noida, Uttar Pradesh (India); Ray, Saibal [Government College of Engineering and Ceramic Technology, Department of Physics, Kolkata, West Bengal (India)

    2015-05-15

    In the present paper we obtain an anisotropic analog of the Durgapal and Fuloria (Gen Relativ Gravit 17:671, 1985) perfect fluid solution. The methodology consists of contraction of the anisotropic factor Δ with the help of both metric potentials e{sup ν} and e{sup λ}. Here we consider e{sup λ} the same as Durgapal and Fuloria (Gen Relativ Gravit 17:671, 1985) did, whereas e{sup ν} is as given by Lake (Phys Rev D 67:104015, 2003). The field equations are solved by the change of dependent variable method. The solutions set mathematically thus obtained are compared with the physical properties of some of the compact stars, strange star as well as white dwarf. It is observed that all the expected physical features are available related to the stellar fluid distribution, which clearly indicates the validity of the model. (orig.)

  9. Compact oleic acid in HAMLET.

    Science.gov (United States)

    Fast, Jonas; Mossberg, Ann-Kristin; Nilsson, Hanna; Svanborg, Catharina; Akke, Mikael; Linse, Sara

    2005-11-07

    HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a complex between alpha-lactalbumin and oleic acid that induces apoptosis in tumor cells, but not in healthy cells. Heteronuclear nuclear magnetic resonance (NMR) spectroscopy was used to determine the structure of 13C-oleic acid in HAMLET, and to study the 15N-labeled protein. Nuclear Overhauser enhancement spectroscopy shows that the two ends of the fatty acid are in close proximity and close to the double bond, indicating that the oleic acid is bound to HAMLET in a compact conformation. The data further show that HAMLET is a partly unfolded/molten globule-like complex under physiological conditions.

  10. Magnetohydodynamics stability of compact stellarators

    International Nuclear Information System (INIS)

    Fu, G.Y.; Ku, L.P.; Cooper, W.A.; Hirshman, S.H.

    2000-01-01

    Recent stability results of external kink modes and vertical modes in compact stellarators are presented. The vertical mode is found to be stabilized by externally generated poloidal flux. A simple stability criterion is derived in the limit of large aspect ratio and constant current density. For a wall at infinite distance from the plasma, the amount of external flux needed for stabilization is given by Fi = (k2 minus k)=(k2 + 1), where k is the axisymmetric elongation and Fi is the fraction of the external rotational transform. A systematic parameter study shows that the external kink mode in QAS can be stabilized at high beta (approximately 5%) without a conducting wall by magnetic shear via 3D shaping. It is found that external kinks are driven by both parallel current and pressure gradient. The pressure contributes significantly to the overall drive through the curvature term and the Pfirsch-Schluter current

  11. A Compact UWB Diversity Antenna

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2014-01-01

    Full Text Available A compact printed ultrawideband (UWB diversity antenna with a size of 30 mm × 36 mm operating at a frequency range of 3.1–10.6 GHz is proposed. The antenna is composed of two semielliptical monopoles fed by two microstrip lines. Two semicircular slots, two rectangular slots, and one stub are introduced in the ground plane to adjust the impedance bandwidth of the antenna and improve the isolation between two feeding ports. The simulated and measured results show that impedance bandwidth of the proposed antenna can cover the whole UWB band with a good isolation of < −15 dB. The radiation patterns, peak antenna gain, and envelope correlation coefficient are also measured and discussed. The measured results show that the proposed antenna can be a good candidate for some portable MIMO/diversity UWB applications.

  12. Compact Digital High Voltage Charger

    CERN Document Server

    Li, Ge

    2005-01-01

    The operation of classical resonant circuit developed for the pulse energizing is investigated. The HV pulse or generator is very compact by a soft switching circuit made up of IGBT working at over 30 kHZ. The frequencies of macro pulses andμpulses can be arbitrarily tuned below resonant frequency to digitalize the HV pulse power. Theμpulses can also be connected by filter circuit to get the HVDC power. The circuit topology is given and its novel control logic is analyzed by flowchart. The circuit is part of a system consisting of a AC or DC LV power supply, a pulse transformer, the pulse generator implemented by LV capacitor and leakage inductance of the transformer, a HV DC or pulse power supply and the charged HV capacitor of the modulators.

  13. Compact Microwave Fourier Spectrum Analyzer

    Science.gov (United States)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry

    2009-01-01

    A compact photonic microwave Fourier spectrum analyzer [a Fourier-transform microwave spectrometer, (FTMWS)] with no moving parts has been proposed for use in remote sensing of weak, natural microwave emissions from the surfaces and atmospheres of planets to enable remote analysis and determination of chemical composition and abundances of critical molecular constituents in space. The instrument is based on a Bessel beam (light modes with non-zero angular momenta) fiber-optic elements. It features low power consumption, low mass, and high resolution, without a need for any cryogenics, beyond what is achievable by the current state-of-the-art in space instruments. The instrument can also be used in a wide-band scatterometer mode in active radar systems.

  14. Optimal shapes of compact strings

    International Nuclear Information System (INIS)

    Maritan, A.; Micheletti, C.; Trovato, A.; Banavar, J.R.

    2000-07-01

    Optimal geometrical arrangements, such as the stacking of atoms, are of relevance in diverse disciplines. A classic problem is the determination of the optimal arrangement of spheres in three dimensions in order to achieve the highest packing fraction; only recently has it been proved that the answer for infinite systems is a face-centred-cubic lattice. This simply stated problem has had a profound impact in many areas, ranging from the crystallization and melting of atomic systems, to optimal packing of objects and subdivision of space. Here we study an analogous problem-that of determining the optimal shapes of closely packed compact strings. This problem is a mathematical idealization of situations commonly encountered in biology, chemistry and physics, involving the optimal structure of folded polymeric chains. We find that, in cases where boundary effects are not dominant, helices with a particular pitch-radius ratio are selected. Interestingly, the same geometry is observed in helices in naturally-occurring proteins. (author)

  15. Physics of Compact Advanced Stellarators

    International Nuclear Information System (INIS)

    Zarnstorff, M.C.; Berry, L.A.; Brooks, A.; Fredrickson, E.; Fu, G.-Y.; Hirshman, S.; Hudson, S.; Ku, L.-P.; Lazarus, E.; Mikkelsen, D.; Monticello, D.; Neilson, G.H.; Pomphrey, N.; Reiman, A.; Spong, D.; Strickler, D.; Boozer, A.; Cooper, W.A.; Goldston, R.; Hatcher, R.; Isaev, M.; Kessel, C.; Lewandowski, J.; Lyon, J.; Merkel, P.; Mynick, H.; Nelson, B.E.; Nuehrenberg, C.; Redi, M.; Reiersen, W.; Rutherford, P.; Sanchez, R.; Schmidt, J.; White, R.B.

    2001-01-01

    Compact optimized stellarators offer novel solutions for confining high-beta plasmas and developing magnetic confinement fusion. The 3-D plasma shape can be designed to enhance the MHD stability without feedback or nearby conducting structures and provide drift-orbit confinement similar to tokamaks. These configurations offer the possibility of combining the steady-state low-recirculating power, external control, and disruption resilience of previous stellarators with the low-aspect ratio, high beta-limit, and good confinement of advanced tokamaks. Quasi-axisymmetric equilibria have been developed for the proposed National Compact Stellarator Experiment (NCSX) with average aspect ratio 4-4.4 and average elongation of approximately 1.8. Even with bootstrap-current consistent profiles, they are passively stable to the ballooning, kink, vertical, Mercier, and neoclassical-tearing modes for beta > 4%, without the need for external feedback or conducting walls. The bootstrap current generates only 1/4 of the magnetic rotational transform at beta = 4% (the rest is from the coils), thus the equilibrium is much less nonlinear and is more controllable than similar advanced tokamaks. The enhanced stability is a result of ''reversed'' global shear, the spatial distribution of local shear, and the large fraction of externally generated transform. Transport simulations show adequate fast-ion confinement and thermal neoclassical transport similar to equivalent tokamaks. Modular coils have been designed which reproduce the physics properties, provide good flux surfaces, and allow flexible variation of the plasma shape to control the predicted MHD stability and transport properties

  16. Compact autonomous navigation system (CANS)

    Science.gov (United States)

    Hao, Y. C.; Ying, L.; Xiong, K.; Cheng, H. Y.; Qiao, G. D.

    2017-11-01

    Autonomous navigation of Satellite and constellation has series of benefits, such as to reduce operation cost and ground station workload, to avoid the event of crises of war and natural disaster, to increase spacecraft autonomy, and so on. Autonomous navigation satellite is independent of ground station support. Many systems are developed for autonomous navigation of satellite in the past 20 years. Along them American MANS (Microcosm Autonomous Navigation System) [1] of Microcosm Inc. and ERADS [2] [3] (Earth Reference Attitude Determination System) of Honeywell Inc. are well known. The systems anticipate a series of good features of autonomous navigation and aim low cost, integrated structure, low power consumption and compact layout. The ERADS is an integrated small 3-axis attitude sensor system with low cost and small volume. It has the Earth center measurement accuracy higher than the common IR sensor because the detected ultraviolet radiation zone of the atmosphere has a brightness gradient larger than that of the IR zone. But the ERADS is still a complex system because it has to eliminate many problems such as making of the sapphire sphere lens, birefringence effect of sapphire, high precision image transfer optical fiber flattener, ultraviolet intensifier noise, and so on. The marginal sphere FOV of the sphere lens of the ERADS is used to star imaging that may be bring some disadvantages., i.e. , the image energy and attitude measurements accuracy may be reduced due to the tilt image acceptance end of the fiber flattener in the FOV. Besides Japan, Germany and Russia developed visible earth sensor for GEO [4] [5]. Do we have a way to develop a cheaper/easier and more accurate autonomous navigation system that can be used to all LEO spacecraft, especially, to LEO small and micro satellites? To return this problem we provide a new type of the system—CANS (Compact Autonomous Navigation System) [6].

  17. General Relativity and Compact Stars

    International Nuclear Information System (INIS)

    Glendenning, Norman K.

    2005-01-01

    Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10 14 times denser than Earth. Some neutron stars are in binary orbit with a companion. Application of orbital mechanics allows an assessment of masses in some cases. The mass of a neutron star is typically 1.5 solar masses. They can therefore infer their radii: about ten kilometers. Into such a small object, the entire mass of our sun and more, is compressed

  18. Nonlinear momentum compaction and coherent synchrotron radiation at the metrology light source. Low-α commissioning and development

    International Nuclear Information System (INIS)

    Ries, Markus

    2014-01-01

    Short pulses of synchrotron radiation are becoming an increasingly demanded tool in various fields of science. The generation of short synchrotron radiation pulses can be accomplished by different accelerator-based approaches such as free electron lasers, energy recovery linacs or electron storage rings. Linear accelerator driven free electron lasers are capable of generating intense pulses in the femtosecond regime at moderate repetition rates. In comparison, electron storage rings generate pulses of lower intensity with the advantage of large repetition rates. However, electron storage rings rely on radiation emitted by the same bunch(es) every turn, which are present in an equilibrium state. Thus making the electron storage ring a yet unchallenged source of short synchrotron radiation pulses in terms of stability and reproducibility. In addition, storage rings are capable to serve a large number of users simultaneously. In general, it is possible to distinguish the user community of short pulses at electron storage rings. The first user group is interested in time-resolution applying incoherent synchrotron radiation up to the X-ray regime. The second user group makes use of coherent synchrotron radiation emitted by short bunches at wavelengths large compared to the bunch dimensions, which commonly applies up to the THz-regime. Both user groups are interested in the high average power and stability available at electron storage rings. However, there is a current limitation for stable short bunch operation of electron storage rings, which is due to an instability driven by the emission of coherent synchrotron radiation. The subject of this thesis is the operation of an electron storage ring at a low momentum compaction to generate short electron bunches as a source for coherent synchrotron radiation. For this purpose the Metrology Light Source is ideally suited, as it is the first light source designed with the ability to adjust the three leading orders of the

  19. Autoradiography of 90Sr in developing rats

    International Nuclear Information System (INIS)

    Olsen, I.; Jonsen, J.

    1979-01-01

    The distribution patterns of 90 Sr in five littermate, 8-day-old Wistar rats were studied by whole body autoradiography. Rats were killed 15 min, 1, 4, 24, and 72 h after a single intraperitoneal injection of the isotope. Immediately after administration, 90 Sr was distributed throughout most of the soft tissues of the body. The soft tissue deposits had practically disappeared after 4 h. In the hard tissues of the body 90 Sr accumulated up to 24-72 h. Fifteen minutes after injection the uptake of 90 Sr in the enamel of the teeth was highest in the occlusal and incisal regions. 90 Sr gradually accumulated throughout the enamel and after 72 h its distribution in this layer was fairly uniform. Immediately after injection a narrow zone of radioactivity appeared in the dentin near the pulp. This zone broadened with time towards the dentinoenamel junction and included the intire dentin layer 72 h after injection. Initially, the uptake of 90 Sr was higher in the dentin than in the enamel, particularly in the cervical areas of the crown. This difference became less apparent with time. There was good correlation between the uptake in the teeth and bones, supporting the use of teeth as indicators of the 90 Sr body burden. (author)

  20. Maxdose-SR and popdose-SR routine release atmospheric dose models used at SRS

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, G. T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Trimor, P. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-28

    MAXDOSE-SR and POPDOSE-SR are used to calculate dose to the offsite Reference Person and to the surrounding Savannah River Site (SRS) population respectively following routine releases of atmospheric radioactivity. These models are currently accessed through the Dose Model Version 2014 graphical user interface (GUI). MAXDOSE-SR and POPDOSE-SR are personal computer (PC) versions of MAXIGASP and POPGASP, which both resided on the SRS IBM Mainframe. These two codes follow U.S. Nuclear Regulatory Commission (USNRC) Regulatory Guides 1.109 and 1.111 (1977a, 1977b). The basis for MAXDOSE-SR and POPDOSE-SR are USNRC developed codes XOQDOQ (Sagendorf et. al 1982) and GASPAR (Eckerman et. al 1980). Both of these codes have previously been verified for use at SRS (Simpkins 1999 and 2000). The revisions incorporated into MAXDOSE-SR and POPDOSE-SR Version 2014 (hereafter referred to as MAXDOSE-SR and POPDOSE-SR unless otherwise noted) were made per Computer Program Modification Tracker (CPMT) number Q-CMT-A-00016 (Appendix D). Version 2014 was verified for use at SRS in Dixon (2014).

  1. Crystal structures of KM(AsF{sub 6}){sub 3} (M{sup 2+} = Mg, Co, Mn, Zn), KCu(SbF{sub 6}){sub 3} and [Co(HF){sub 2}]Sr[Sr(HF)]{sub 2}-[Sr(HF){sub 2}]{sub 2}[AsF{sub 6}]{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Mazej, Zoran; Goreshnik, Evgeny [Jozef Stefan Institute, Ljubljana (Slovakia). Dept. of Inorganic Chemisrty and Technology

    2015-05-01

    The KM(AsF{sub 6}){sub 3} (M{sup 2+} = Mg, Co, Mn, Zn) and KCu(SbF{sub 6}){sub 3} compounds crystallize isotypically to previously known KNi(AsF{sub 6}){sub 3}. The main features of the structure of these compounds are rings of MF{sub 6} octahedra sharing apexes with AsF{sub 6} octahedra connected into infinite tri-dimensional frameworks. In this arrangement cavities are formed where K{sup +} cations are placed. Single crystals of CoSr{sub 5}(AsF{sub 6}){sub 12}.8HF were obtained as one of the products after the crystallization of 3KF/CoF{sub 2}/SrF{sub 2} mixture in the presence of AsF{sub 5} in anhydrous HF. The CoSr{sub 5}(AsF{sub 6}){sub 12}.8HF is monoclinic, C/2c (No.15), with a = 26.773(5) Aa, b = 10.087(2) Aa, c = 21.141(5) Aa, β = 93.296(13) {sup circle}, V = 5699.9(19) Aa{sup 3} at 200 K, and Z = 4. There are three crystallographically non-equivalent Sr{sup 2+} cations in the crystal structure of CoSr{sub 5}(AsF{sub 6}){sub 12}.8HF. The Sr1 is coordinated by ten fluorine atoms from eight different [AsF{sub 6}]- anions, meanwhile Sr2 and Sr3 are bound to nine fluorine atoms provided by one HF and eight AsF{sub 6} units or by two HF and six AsF{sub 6} units, respectively. The Co{sup 2+} is coordinated distorted-octahedrally by six fluorine atoms from two HF molecules and four different AsF{sub 6} units. All those moieties in the crystal structure of [Co(HF){sub 2}]Sr[Sr(HF)]{sub 2}[Sr(HF){sub 2}]{sub 2}[AsF{sub 6}]{sub 12} are connected into tridimensional framework. The CoSr{sub 5}(AsF{sub 6}){sub 12}.8HF is a unique example of compound where HF molecules are directly bound via fluorine atoms to two different metal centres.

  2. Crystal structures of KM(AsF6)3 (M2+ = Mg, Co, Mn, Zn), KCu(SbF6)3 and [Co(HF)2]Sr[Sr(HF)]2-[Sr(HF)2]2[AsF6]12

    International Nuclear Information System (INIS)

    Mazej, Zoran; Goreshnik, Evgeny

    2015-01-01

    The KM(AsF 6 ) 3 (M 2+ = Mg, Co, Mn, Zn) and KCu(SbF 6 ) 3 compounds crystallize isotypically to previously known KNi(AsF 6 ) 3 . The main features of the structure of these compounds are rings of MF 6 octahedra sharing apexes with AsF 6 octahedra connected into infinite tri-dimensional frameworks. In this arrangement cavities are formed where K + cations are placed. Single crystals of CoSr 5 (AsF 6 ) 12 .8HF were obtained as one of the products after the crystallization of 3KF/CoF 2 /SrF 2 mixture in the presence of AsF 5 in anhydrous HF. The CoSr 5 (AsF 6 ) 12 .8HF is monoclinic, C/2c (No.15), with a = 26.773(5) Aa, b = 10.087(2) Aa, c = 21.141(5) Aa, β = 93.296(13) circle , V = 5699.9(19) Aa 3 at 200 K, and Z = 4. There are three crystallographically non-equivalent Sr 2+ cations in the crystal structure of CoSr 5 (AsF 6 ) 12 .8HF. The Sr1 is coordinated by ten fluorine atoms from eight different [AsF 6 ]- anions, meanwhile Sr2 and Sr3 are bound to nine fluorine atoms provided by one HF and eight AsF 6 units or by two HF and six AsF 6 units, respectively. The Co 2+ is coordinated distorted-octahedrally by six fluorine atoms from two HF molecules and four different AsF 6 units. All those moieties in the crystal structure of [Co(HF) 2 ]Sr[Sr(HF)] 2 [Sr(HF) 2 ] 2 [AsF 6 ] 12 are connected into tridimensional framework. The CoSr 5 (AsF 6 ) 12 .8HF is a unique example of compound where HF molecules are directly bound via fluorine atoms to two different metal centres.

  3. A CPW-Fed Rectangular Ring Monopole Antenna for WLAN Applications

    Directory of Open Access Journals (Sweden)

    Sangjin Jo

    2014-01-01

    Full Text Available We present a simple coplanar waveguide- (CPW- fed rectangular ring monopole antenna designed for dual-band wireless local area network (WLAN applications. The antenna is based on a simple structure composed of a CPW feed line and a rectangular ring. Dual-band WLAN operation can be achieved by controlling the distance between the rectangular ring and the ground plane of the CPW feed line, as well as the horizontal vertical lengths of the rectangular ring. Simulated and measured data show that the antenna has a compact size of 21.4×59.4 mm2, an impedance bandwidths of 2.21–2.70 GHz and 5.04–6.03 GHz, and a reflection coefficient of less than −10 dB. The antenna also exhibits an almost omnidirectional radiation pattern. This simple compact antenna with favorable frequency characteristics therefore is attractive for applications in dual-band WLAN.

  4. 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

  5. High-pressure synthesis and crystal structures of the strontium oxogallates Sr2Ga2O5 and Sr5Ga6O14

    International Nuclear Information System (INIS)

    Kahlenberg, Volker; Goettgens, Valerie; Mair, Philipp; Schmidmair, Daniela

    2015-01-01

    High-pressure synthesis experiments in a piston–cylinder apparatus at 1.5 GPa/3.0 GPa and 1000 °C resulted in the formation of single-crystals of Sr 2 Ga 2 O 5 and Sr 5 Ga 6 O 14 , respectively. The structures of both compounds have been solved from single-crystal diffraction data sets using direct methods. The first compound is orthorhombic with space group type Pbca (a=10.0021(4) Å, b=9.601(4) Å, c=10.6700(4) Å, V=1024.6(4) Å 3 , M r =394.68 u, Z=8, D x =5.12 g/cm 3 ) and belongs to the group of single layer gallates. Individual sheets are parallel to (0 0 1) and can be built from the condensation of unbranched vierer single chains running along [0 1 0]. The layers are characterized by the presence of four- and strongly elliptical eight-membered rings of corner connected tetrahedra in UUDD and UUUUDDDD conformation. Strontium atoms are sandwiched between the tetrahedral layers for charge compensation and are coordinated by six and seven oxygen ligands, respectively. Sr 2 Ga 2 O 5 is isotypic with several other double sulfides and selenides. To the best of our knowledge, it is the first example of an oxide with this structure type. From a structural point of view, Sr 5 Ga 6 O 14 is a phyllogallate as well. The crystal structure adopts the monoclinic space group P2 1 /c (a=8.1426(3) Å, b=8.1803(3) Å, c=10.8755(4) Å, β=91.970(4)° V=723.98(5) Å 3 , M r =1080.42 u, Z=2, D x =4.96 g/cm 3 ). Individual sheets extend along (0 0 1). Basic building units are unbranched dreier single chains parallel to [1 0 0]. The layers contain tertiary (Q 3 ) und quaternary (Q 4 ) connected [GaO 4 ]-tetrahedra in the ratio 2:1 resulting in a Ga:O ratio of 3:7 and the formation of exclusively five-membered rings. Linkage between adjacent tetrahedral sheets is provided by three symmetrically independent strontium ions which are surrounded by six to eight oxygen atoms. The layers in Sr 5 Ga 6 O 14 are similar to those observed in the melilite structure-type. Crystallochemical

  6. On compact multipliers of topological algebras

    International Nuclear Information System (INIS)

    Mohammad, N.

    1994-08-01

    It is shown that if the maximal ideal space Δ(A) of a semisimple commutative complete metrizable locally convex algebra contains no isolated points, then every compact multiplier is trivial. Particularly, compact multipliers on semisimple commutative Frechet algebras whose maximal ideal space has no isolated points are identically zero. (author). 5 refs

  7. Compaction Characteristics of Igumale Shale | Iorliam | Global ...

    African Journals Online (AJOL)

    This paper reports the outcome of an investigation into the effect of different compactive energies on the compaction characteristics of Igumale shale, to ascertain its suitability as fill material in highway ... The study showed that Igumale shale is not suitable for use as base, subbase and filling materials in road construction.

  8. Compact Process Development at Babcock & Wilcox

    Energy Technology Data Exchange (ETDEWEB)

    Eric Shaber; Jeffrey Phillips

    2012-03-01

    Multiple process approaches have been used historically to manufacture cylindrical nuclear fuel compacts. Scale-up of fuel compacting was required for the Next Generation Nuclear Plant (NGNP) project to achieve an economically viable automated production process capable of providing a minimum of 10 compacts/minute with high production yields. In addition, the scale-up effort was required to achieve matrix density equivalent to baseline historical production processes, and allow compacting at fuel packing fractions up to 46% by volume. The scale-up approach of jet milling, fluid-bed overcoating, and hot-press compacting adopted in the U.S. Advanced Gas Reactor (AGR) Fuel Development Program involves significant paradigm shifts to capitalize on distinct advantages in simplicity, yield, and elimination of mixed waste. A series of compaction trials have been completed to optimize compaction conditions of time, temperature, and forming pressure using natural uranium oxycarbide (NUCO) fuel at packing fractions exceeding 46% by volume. Results from these trials are included. The scale-up effort is nearing completion with the process installed and operable using nuclear fuel materials. Final process testing is in progress to certify the process for manufacture of qualification test fuel compacts in 2012.

  9. Investigation of pressing of molybdenum powder compacts

    International Nuclear Information System (INIS)

    Mymrin, S.A.; Kuznetsov, V.Eh.; Yampol'skij, M.L.; Leonov, S.A.; Mikhridinov, R.M.; Korzukhin, V.A.

    1990-01-01

    Results of an experimental investigation into pressing of compacts of MCh type molybdenum powders using the industrial equipment are presented. To measure the density of powder molybdenum billets a radioisotopic density meter with cesium-137 is used as radioactive gamma radiation source. The dependence of the produced billet density on the specific compacting pressure at different values of the powder bulk density is ascertained

  10. Compact fuel storage rack for fuel pools

    International Nuclear Information System (INIS)

    Parras, F.; Louvat, J.P.

    1986-01-01

    ETS LEMER and FRAMATOME propose a new compact storage rack. This rack permits a considerable increase of the storage capacity of cooling pools. A short description of the structure and the components is presented, to propose racks that are: . Inalterable, . Compact, . Insensitive to earthquakes. Installation in pools already in operation is simplified by their light structure and the bearing device [fr

  11. Quantification of the compactibility of pharmaceutical powders

    DEFF Research Database (Denmark)

    Sonnergaard, Jørn

    2006-01-01

    The purpose of this study is to investigate and to quantify the compactibility of pharmaceutical powders by a simple linear relationship between the diametral compressive strength of tablets and the applied compaction pressure. The mechanical strength of the tablets is characterized as the crushing...

  12. Feature Based Control of Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh

    Two servo control loops are used to keep the Optical Pick-up Unit focused and radially on the information track of the Compact Disc. These control servos have problems handling surface faults on the Compact Disc. In this Ph.D thesis a method is proposed to improve the handling of these surface...

  13. Computing Decoupled Residuals for Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

    2006-01-01

    a pair of residuals generated by Compact Disc Player. However, these residuals depend on the performance of position servos in the Compact Disc Player. In other publications of the same authors a pair of decoupled residuals is derived. However, the computation of these alternative residuals has been...

  14. The classification of 2-compact groups

    DEFF Research Database (Denmark)

    K. S. Andersen, Kasper; Grodal, Jesper

    2009-01-01

    with Moeller and Viruel for p odd, this establishes the full classification of p-compact groups, stating that, up to isomorphism, there is a one-to-one correspondence between connected p-compact groups and root data over the p-adic integers. As a consequence we prove the maximal torus conjecture, giving a one...

  15. Report on nuclear energy in SR Slovenia

    International Nuclear Information System (INIS)

    1987-01-01

    Currently Yugoslavia has one 632 MWe nuclear power plant (NPP) of PWR design, located at Krsko in the Socialist Republic (SR) of Slovenia. Krsko NPP, which is a two-loop plant, started power operation in 1981. In general, reactor safety activities in the SR of Slovenia are mostly related to upgrading the safety of our Krsko NPP and to developing capabilities for use in future units. This report presents the nuclear safety related legislation and organization of the corresponding regulatory body, and the activities related to nuclear safety of the participating organizations in the SR of Slovenia in 1987.

  16. Ring diagrams and phase transitions

    International Nuclear Information System (INIS)

    Takahashi, K.

    1986-01-01

    Ring diagrams at finite temperatures carry most infrared-singular parts among Feynman diagrams. Their effect to effective potentials are in general so significant that one must incorporate them as well as 1-loop diagrams. The author expresses these circumstances in some examples of supercooled phase transitions

  17. WR stars with ring nebulae

    International Nuclear Information System (INIS)

    Tutukov, A.

    1982-01-01

    It is shown that most of usually apparently single nitrogen WR stars with ring emission nebulae around them (WN + Neb) are a probable product of the evolution of a massive close binary with initial masses of components exceeding approximately 20 solar masses. (Auth.)

  18. Alignment for new Subaru ring

    International Nuclear Information System (INIS)

    Zhang, Ch.; Matsui, S.; Hashimoto, S.

    1999-01-01

    The New SUBARU is a synchrotron light source being constructed at the SPring-8 site. The main facility is a 1.5 GeV electron storage ring that provides light beam in the region from VUV to soft X-ray using SPring-8's 1 GeV linac as an injector. The ring, with a circumference of about 119 meters, is composed of six bending cells. Each bending cell has two normal dipoles of 34 degree and one inverse dipole of -8 degree. The ring has six straight sections: two very long straight sections for a 11-m long undulator and an optical klystron, four short straight sections for a 2.3-m undulator, a super-conducting wiggler, rf cavity and injection, etc. The magnets of the storage ring are composed of 12 dipoles (BMs), 6 invert dipoles (BIs), 56 quadrupoles and 44 sextupoles, etc. For the magnet alignment, positions of the dipoles (the BMs and BIs) are determined by network survey method. The multipoles, which are mounted on girders between the dipoles, are aligned with a laser-CCD camera system. This article presents the methodology used to position the different components and particularly to assure the precise alignment of the multipoles. (authors)

  19. Characteristic of Rings. Prime Fields

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-12-01

    Full Text Available The notion of the characteristic of rings and its basic properties are formalized [14], [39], [20]. Classification of prime fields in terms of isomorphisms with appropriate fields (ℚ or ℤ/p are presented. To facilitate reasonings within the field of rational numbers, values of numerators and denominators of basic operations over rationals are computed.

  20. Ring laser frequency biasing mechanism

    International Nuclear Information System (INIS)

    McClure, R.E.

    1975-01-01

    A ring laser cavity including a magnetically saturable member for differentially phase shifting the contradirectional waves propagating in the laser cavity, the phase shift being produced by the magneto-optic interaction occurring between the light waves and the magnetization in the cavity forming component as the light waves are reflected therefrom is described