WorldWideScience

Sample records for spirally fluted tubing

  1. CFD investigation of flow and heat transfer of nanofluids in isoflux spirally fluted tubes

    KAUST Repository

    Salama, Amgad

    2012-01-01

    In this work, the problem of flow and heat transfer of nanofluids in spirally fluted tubes is investigated numerically using the CFD code Fluent. The tube investigated in this work is characterized by the existence of helical ridging which is usually obtained by embossing a smooth tube. A tube of diameter of 15 mm, 1.5 mm groove depth and a single helix with pitch of 64 mm is chosen for simulation. This geometry has been chosen for simulation because it has been investigated experimentally for pure fluids and would, therefore, provide a verification framework with our CFD model. The result of our CFD investigation compares very well with the experimental work conducted on this tube geometry. Interesting patterns are highlighted and investigated including the existence of flow swirl as a result of the existence of the spirally enhanced ridges. This swirl flow enhances heat transfer characteristics of this system as reported in the literatures. This study also shows that further enhancement is achieved if small amount of nanoparticles are introduced to the fluid. These nanoparticles (metallic-based nanoparticles) when introduced to the fluid enhances its heat transfer characteristics.

  2. Fluting Modes in Transversely Nonuniform Solar Flux Tubes

    Science.gov (United States)

    Soler, Roberto

    2017-12-01

    Magnetohydrodynamic waves of different types are frequently observed in magnetic flux tubes of the solar atmosphere and are often modeled using simple models. In the standard flux tube model made of a straight uniform tube with an abrupt boundary, transverse wave modes are classified according to their azimuthal wavenumber, m. Sausage (m = 0) and kink (m = 1) modes produce pulsations of the cross section and transverse oscillations of tube axis, respectively. Both sausage and kink modes have been observed in the solar atmosphere. Fluting (m≥slant 2) modes produce perturbations that are essentially confined around the boundary of the tube, I.e., they have a strong surface-like character. Unlike sausage and kink modes, the detection of fluting modes remains elusive. Here we show that the inclusion of transverse inhomogeneity in the flux tube model dramatically affects the properties of fluting modes. Even in a thin tube, kink and fluting modes are no longer degenerate in frequency when the tube has a smooth boundary. In addition, fluting modes become heavily damped by resonant absorption in a timescale shorter than the oscillation period. The perturbations loose their global shape and their distinctive surface-like appearance. As a consequence of that, we argue that nonuniform flux tubes with smooth boundaries may not be able to support fluting-like perturbations as coherent, global modes.

  3. SPIRAL COUNTER-CURRENT CHROMATOGRAPHY OF SMALL MOLECULES, PEPTIDES AND PROTEINS USING THE SPIRAL TUBING SUPPORT ROTOR

    OpenAIRE

    Knight, Martha; Finn, Thomas M.; Zehmer, John; Clayton, Adam; Pilon, Aprile

    2011-01-01

    An important advance in countercurrent chromatography (CCC) carried out in open flow-tubing coils, rotated in planetary centrifuges, is the new design to spread out the tubing in spirals. More spacing between the tubing was found to significantly increase the stationary phase retention, such that now all types of two-phase solvent systems can be used for liquid-liquid partition chromatography in the J-type planetary centrifuges. A spiral tubing support (STS) frame with circular channels was c...

  4. Chemical milling of zircaloy tubing to produce integral OD spiral finned tubes. AWBA development program

    Science.gov (United States)

    Horwood, W. A.

    1982-02-01

    A detailed process description is provided for producing integral spiral fins on the outside surface of Zircaloy nuclear fuel cladding tubes by masking with pressure sensitive tape strips and then chemical milling (pickling) the tube wall between the tape strips to leave the fins in relief. Fins up to 0.020 inch high by 0.05 to 0.12 inch wide were consistently produced on tubes having wall thickness of 0.008 inch or greater after fin pickling. Wall thickness uniformity was excellent. Information is provided on tube surface preparation to maximize tape mask adhesion time during pickling, acid chemistry control to prevent local tube wall thinning near the fin, and pickling techniques to promote uniform material removal. Simple fixture designs are described for quickly and conveniently applying the tape strips to the tube wall in an accurate spiral.

  5. Heat transfer enhancement in two-start spirally corrugated tube

    Directory of Open Access Journals (Sweden)

    Zaid S. Kareem

    2015-09-01

    Full Text Available Various techniques have been tested on heat transfer enhancement to upgrade the involving equipment, mainly in thermal transport devices. These techniques unveiled significant effects when utilized in heat exchangers. One of the most essential techniques used is the passive heat transfer technique. Corrugations represent a passive technique. In addition, it provides effective heat transfer enhancement because it combined the features of extended surfaces, turbulators and artificial roughness. Therefore, A Computational Fluid Dynamics was employed for water flowing at low Reynolds number in spiral corrugated tubes. This article aimed for the determination of the thermal performance of unique smooth corrugation profile. The Performance Evaluation Criteria were calculated for corrugated tubes, and the simulation results of both Nusselt number and friction factor were compared with those of standard plain and corrugated tubes for validation purposes. Results showed the best thermal performance range of 1.8–2.3 for the tube which has the severity of 45.455 × 10−3 for Reynolds number range of 100–700. The heat transfer enhancement range was 21.684%–60.5402% with friction factor increase of 19.2–36.4%. This indicated that this creative corrugation can improve the heat transfer significantly with appreciably increasing friction factor.

  6. Strain-based design procedures for spiral-welded steel tubes in combined walls

    NARCIS (Netherlands)

    Gresnigt, A.M.; van Es, S.H.J.; Vasilikis, D; Karamanos, SA; Dubina, D.; Ungureanu, V.

    2016-01-01

    To investigate the structural behaviour of large-diameter spiral-welded steel tubes under bending, a full scale experimental program has been performed, consisting of thirteen 42-inch diameter, spiral-welded steel tubes with D/t ratios ranging between 65 and 120. Additionally, numerical studies have

  7. Flute Choir Fundamentals

    Science.gov (United States)

    Chappell, Jon

    2007-01-01

    The flute is one of the more accessible instruments for beginners and is a popular choice for many elementary and middle school students. It is relatively easy to create a decent, usable sound with a flute, and it is more portable than most instruments. While starting a flute choir has a lot of benefits, arranging a band has a lot of challenges.…

  8. Application of spiral nasointestinal tube in enteral nutrition support for patients with extensive burn

    Directory of Open Access Journals (Sweden)

    Lai-Ping Wang

    2016-09-01

    Full Text Available Objective: To observe the effect of spiral nasointestinal tube on enteral nutrition support in patients with extensive burn. Methods: A total of 60 patients with extensive burn who were admitted in our hospital from January, 2014 to June, 2015 were included in the study and divided into the observation group and the control group with 30 cases in each group according to different catheter indwelling methods. The patients in the observation group were given spiral nasointestinal tube for enteral nutrition support, while the patients in the control group were given routine gastric tube for enteral nutrition support. The nutrition status and the occurrence rate of complications before catheter indwelling, 3, 6, and 10 d after catheter indwelling in the two groups were recorded. Results: The levels of ALB, HB, PA, and Scr 6, 10 d after catheter indwelling in the observation group were significantly higher than those in the control group (P<0.05. The occurrence rate of complications during the treatment period in the observation group was significantly lower than that in the control group (P<0.05. Conclusions: The spiral nasointestinal tube can provide the patients with extensive burn a better effective enteral nutrition support and improve the nutrition support, with a lower occurrence rate of complications, which is beneficial for the patients’ rehabilitation.

  9. EXPERIMENTAL INVESTIGATION OF THE CONVECTIVE HEAT TRANSFER IN A SPIRALLY COILED CORRUGATED TUBE WITH RADIANT HEATING

    Directory of Open Access Journals (Sweden)

    Milan Đorđević

    2017-12-01

    Full Text Available The Archimedean spiral coil made of a transversely corrugated tube was exposed to radiant heating in order to represent a heat absorber of the parabolic dish solar concentrator. The main advantage of the considered innovative design solution is a coupling effect of the two passive methods for heat transfer enhancement - coiling of the flow channel and changes in surface roughness. The curvature ratio of the spiral coil varies from 0.029 to 0.234, while water and a mixture of propylene glycol and water are used as heat transfer fluids. The unique focus of this study is on specific boundary conditions since the heat flux upon the tube external surfaces varies not only in the circumferential direction, but in the axial direction as well. Instrumentation of the laboratory model of the heat absorber mounted in the radiation field includes measurement of inlet fluid flow rate, pressure drop, inlet and outlet fluid temperature and 35 type K thermocouples welded to the coil surface. A thermal analysis of the experimentally obtained data implies taking into consideration the externally applied radiation field, convective and radiative heat losses, conduction through the tube wall and convection to the internal fluid. The experimental results have shown significant enhancement of the heat transfer rate compared to spirally coiled smooth tubes, up to 240% in the turbulent flow regime.

  10. Use of Extended Flute Techniques in Flute Education in Turkey

    Science.gov (United States)

    Sakin, Ajda Senol

    2018-01-01

    Extended flute techniques, which are frequently found in contemporary flute literature, carry the flute to a different dimension, pushing the boundaries of composers and performers. Although the number of pieces containing these techniques in the world has increased rapidly, along with Turkish flute repertoire, written Turkish sources about…

  11. Spiral multiple-effect diffusion solar still coupled with vacuum-tube collector and heat pipe

    KAUST Repository

    Huang, Bin-Juine

    2015-04-01

    © 2015 Elsevier B.V. A novel solar still with spiral-shape multiple-effect diffusion unit is developed in the present study. The test results of a 14-effect unit coupled with vacuum-tube solar collector (absorber area 1.08m2) show that the highest daily pure water production is 40.6kgd-1. The measured highest productivity based on the area of glass cover, solar absorber, and evaporating surface is 34.7, 40.6, and 7.96kgm-2d-1, respectively, which are much higher than the published results. The measured solar distillation efficiency is 2.0-3.5. The performance enhancement results mainly from the lateral diffusion process in the spiraled still cell. The vapor flow generated by heat input can flow freely and laterally through the spiral channel down to the end when solar heat input is high. Besides, the larger evaporating and condensing area at the outer cell may increase heat and mass transfer at the outer cell.

  12. Numerical Investigation of the Fully-Developed Periodic Flow Field for Optimal Heat Transfer in Spirally Corrugated Tubes

    DEFF Research Database (Denmark)

    Hærvig, Jakob; Condra, Thomas Joseph; Sørensen, Kim

    Even though the corrugated tube is a widely used technique to enhance transfer heat, the exact heat transfer enhancing mechanism remains relatively un-documented. Most studies attribute the favourable heat transfer characteristics to a swirling flow being present at higher corrugation....... In this study, a systematic approach relying on Computational Fluid Dynamics (CFD) is used to study and compare the heat transfer characteristics with the detailed flow field in the spirally corrugated tubes. By comparing the flow in 12 different spirally corrugated tubes at a fixed Reynolds number of 5000......, this study compares the flow field with the surface averaged Nusselt number to gain valuable insight into which flow phenomena causes favourable heat transfer characteristics. While the flow at low corrugations approximates the non-corrugated tube, higher corrugations of h/D creates a significant tangential...

  13. The usefulness of levin tube inserted drip infusion spiral CT: comparison with conventional method in subtotal gastrectomy patients

    International Nuclear Information System (INIS)

    Park, Young Jin; Kim, Young Hwan; Yoon, Jung Hee; Cha, Soon Joo; Kim, Jeong Sook; Kim, Sung Rok; Hur, Gham; Rhim, Hyun Chul

    1998-01-01

    The purpose of this study is to access the usefulness of newly designed Levin tube inserted drip infusion spiral CT for the evaluation of remnant stomach and anastomosis site in patients who have undergone subtotal gastrectomy for stomach cancer. A new technique named Levin tube inserted drip infusion spiral CT was used to prospectively study 23 patients. A 16Fr Levin tube was inserted into the remnant stomach; 500 ml of tap water was drip infused just before CT scanning and an additional 500 ml of water was infused during IV contrast injection. Water was infused by gravity, using a water bottle suspended at a height of 90 cm (Group A). The 31 patients who underwent conventional spiral CT scanning immediately after the divided ingestion of 900 ml diluted gastrografin were selected as a control group (Group B). The anatomic delineation of the anastomosis site was graded by two radiologists as excellent (3), good(2), fair (1) or poor (0). To evaluate the degree of distension, the maximal diameters of remnant stomach and the anastomosis site, and the thickness of the stomach wall, were also measured. In patients who had undergone subtobal gastrectomy, Levin tube inserted drip infusion spiral CT showed excellent anatomic delineation of the site of anastomosis and remnant stomach. We found that because it increases the distension of remnant stomach and the anastomosis site, this technique is effective for the evaluation of postoperative stomach. (author). 10 refs., 2 tabs., 3 figs

  14. Parabolic solar cooker: Cooking with heat pipe vs direct spiral copper tubes

    Science.gov (United States)

    Craig, Omotoyosi O.; Dobson, Robert T.

    2016-05-01

    Cooking with solar energy has been seen by many researchers as a solution to the challenges of poverty and hunger in the world. This is no exception in Africa, as solar coking is viewed as an avenue to eliminate the problem of food insecurity, insufficient energy supply for household and industrial cooking. There are several types of solar cookers that have been manufactured and highlighted in literature. The parabolic types of solar cookers are known to reach higher temperatures and therefore cook faster. These cookers are currently being developed for indoor cooking. This technology has however suffered low cooking efficiency and thus leads to underutilization of the high heat energy captured from the sun in the cooking. This has made parabolic solar cookers unable to compete with other conventional types of cookers. Several methods to maximize heat from the sun for indirect cooking has been developed, and the need to improve on them of utmost urgency. This paper investigates how to optimize the heat collected from the concentrating types of cookers by proposing and comparing two types of cooking sections: the spiral hot plate copper tube and the heat pipe plate. The system uses the concentrating solar parabolic dish technology to focus the sun on a conical cavity of copper tubes and the heat is stored inside an insulated tank which acts both as storage and cooking plate. The use of heat pipes to transfer heat between the oil storage and the cooking pot was compared to the use of a direct natural syphon principle which is achieved using copper tubes in spiral form like electric stove. An accurate theoretical analysis for the heat pipe cooker was achieved by solving the boiling and vaporization in the evaporator side and then balancing it with the condensation and liquid-vapour interaction in the condenser part while correct heat transfer, pressure and height balancing was calculated in the second experiment. The results show and compare the cooking time, boiling

  15. An improved design of spiral tube assembly for separation of proteins by high-speed counter-current chromatography.

    Science.gov (United States)

    Dasarathy, Dhweeja; Ito, Yoichiro

    2015-10-30

    A new spiral tube assembly was designed to improve the column capacity and partition efficiency for protein separation. This spiral tube assembly has greater column capacity than the original tubing because of an increase in radial grooves from 4 to 12 to accommodate more spiral layers and 12 narrow spots instead of 4 in each circular loop to interrupt the laminar flow that causes sample band broadening. Standard PTFE tubing (1.6mm ID) and the modified flat-twisted tubing were used as the separation column. The performances of both assemblies were compared for separating three stable test proteins including cytochrome c, myoglobin, and lysozyme using a two phase aqueous-aqueous solvent system composed of polyethylene glycol 1000 (12.5% w/w) and dibasic potassium phosphate (12.5% w/w). All samples were run at 1, 2, 3, and 5mL/min at both 800rpm and 1000rpm. The separation of these three protein samples produced high stationary phase retentions at 1, 2, and 3mL/min, yet separated efficiently at 5mL/min in 40min. After comparing the separation efficiency in terms of the peak resolutions, theoretical plate numbers, and separation times, it was determined that the flat-twisted tubing was more effective in separating these protein samples. In order to validate the efficacy of this novel assembly, a mixture of five protein samples (cytochrome c, myoglobin, ovalbumin, lysozyme, and hemoglobin) were separated, under the optimal conditions established with these three protein samples, at 1mL/min with a revolution speed of 1000rpm. There were high stationary phase retentions of around 60%, with effective separations, demonstrating the efficiency of the flat-twisted spiral tube assembly. The separation time of 6h was a limitation but can potentially be shortened by improving the strength of the column that will permit an increase in revolution speed and flow rate. This novel spiral separation column will allow rapid and efficient separation of mixtures with high yield of the

  16. Magnitudes of gluteus medius muscle activation during standing hip joint movements in spiral-diagonal patterns using elastic tubing resistance.

    Science.gov (United States)

    Youdas, James W; Adams, Kady E; Bertucci, John E; Brooks, Koel J; Steiner, Meghan M; Hollman, John H

    2015-01-01

    The aim of this study was to simultaneously quantify electromyographic (EMG) activation levels (% maximum voluntary isometric contraction [MVIC]) within the gluteus medius muscles on both moving and stance limbs across the performance of four proprioceptive neuromuscular facilitation (PNF) spiral-diagonal patterns in standing using resistance provided by elastic tubing. Differential EMG activity was recorded from the gluteus medius muscle of 26 healthy participants. EMG signals were collected with surface electrodes at a sampling frequency of 1000 Hz during three consecutive repetitions of each spiral-diagonal movement pattern. Significant differences existed among the four-spiral-diagonal movement patterns (F3,75 = 19.8; p gluteus medius muscle recruitment (50 SD 29.3% MVIC) than any of the other three patterns and the diagonal one extension [D1E] (39 SD 37% MVIC) and diagonal two extension [D2E] (35 SD 29% MVIC) patterns generated more gluteus medius muscle recruitment than diagonal one flexion [D1F] (22 SD 21% MVIC). From a clinical efficiency standpoint, a fitness professional using the spiral-diagonal movement pattern of D2F and elastic tubing with an average peak tension of about 9% body mass may be able to concurrently strengthen the gluteus medius muscle on both stance and moving lower limbs.

  17. Strength of Short Concrete Filled Steel Tube Columns with Spiral Reinforcement

    Science.gov (United States)

    Krishan, A. L.; Troshkina, E. A.; Astafyeva, M. A.

    2017-11-01

    To further increase the bearing capacity and survivability of reinforced concrete filled steel tube (RCFT) columns, it is offered to supply their concrete core with additional spiral reinforcement. Such reinforcement also has a positive effect on the fire resistance of the columns. The practical use of compressed RCFT elements is restrained by the absence of procedures for determining their bearing capacity. A calculation procedure for determining the strength of short centrally compressed RCFT columns is offered. It is rather easy in terms of application and it allows one to take into account the main features of power resistance of such columns. The results of comparison of the calculated strength with experimental data are presented. The analysis of these results testifies that the accuracy of calculation of RCFT columns strength is sufficient for practice. The offered calculation procedure allows to provide the wider use of RCFT columns in construction practice as heavy loaded bearing elements of buildings and structures. It is recommended to use high-strength longitudinal reinforcement for further increase of the efficiency of these columns.

  18. LMTD Design Methodology Assessment of Spiral Tube Heat Exchanger under the S-CO2 cycle operating condition

    International Nuclear Information System (INIS)

    Jung, Hwa Young; Lee, Jeong Ik; Ahn, Yoon Han

    2013-01-01

    The advantages of PCHE are compact high pressure difference endurance high temperature operation. However, PCHE is quite expensive and the resistance to the fast thermal cycling is questionable. In order to overcome this problem, the Korea Advanced Institute of Science and Technology (KAIST) research team is considering an alternative for the PCHE. Currently KAIST research team is using a Spiral Tube Heat Exchanger (STHE) of Sentry Equipment Corp. as a pre cooler in the SCO 2 PE facility. A STHE is relatively cheap but the operating pressure and temperature are acceptable for utilizing it as a pre cooler. A STHE is consisted of spiral shaped tubes (hot side i.e. S-CO 2 ) immersed in a shell (cold side i.e. water). This study is aimed at whether the logarithmic mean temperature difference (LMTD) heat exchanger design methodology is acceptable for designing the S-CO 2 cycle pre cooler. This is because the LMTD method usually assumes a constant specific heat, but the pre cooler in the S-CO 2 cycle operates at the nearest point to the critical point where a dramatic change in properties is expected. Experimentally obtained data are compared to the vendor provided technical specification based on the LMTD method. The detailed specifications provided by the vendor are listed in Table 1

  19. Quality Characteristics of bread made from Wheat and Fluted ...

    African Journals Online (AJOL)

    Bread fortified with fluted pumpkin seed flour was made; the seeds of fluted pumpkin were extracted and processed into raw dried flour. Appropriate quantities of wheat and fluted pumpkin flour (on dry weight basis) were measured and mixed to give the following blends, 90:10, 80:20, 60:40, 50:50, wheat/fluted pumpkin ...

  20. The Flute Music of Frederick II

    OpenAIRE

    Macken, Sarah

    2012-01-01

    Frederick II ‘the Great’ of Prussia (1712-1786) is regarded as one of the greatest aristocratic dilettante musicians and composers of the 18th century. This Master of Arts in Music (Performance) minor dissertation explores his flute music with particular reference to the compositional style of his flute sonatas and concertos. It commences with an overview of Frederick’s musical background, focusing on relevant biographical details that relate both to the formative influences on...

  1. Construction practices in pre-Hispanic flutes

    Science.gov (United States)

    Rawcliffe, Susan

    2002-11-01

    The ancient cultures of the Americas were separated by thousands of miles and thousand of years. There was a long history of trade over the miles and the years with many shared cultural ideals and artifacts, as evidenced by their musical instruments. Flutes were the most prevalent instruments found throughout the ancient Americas. Some types are unique to the pre-Hispanic world. Although flutes were constructed from a variety of materials, including bone, cane, seed pods, skulls, it is primarily the ceramic ones that survived, and it is ceramic flutes which form the bulk of this writer's work and research. This paper includes musical demonstrations to show how ancient flutemakers could have manipulated timbre during construction. Clay's plasticity enabled the construction of some instruments, and limited the development of others. Pitch jump flutes, certain Veracruzano whistles, and chamberduct flutes and whistles all share the addition of clay flaps or chambers around the aperture, as do hooded pipes. Some instruments exhibit a seemingly cultural predilection for complex tones that are windy, raspy, or animalistic. Simple adjustments of the airduct promote these timbres. Also included will be samples of the original sounds of ancient flutes.

  2. Spiral Countercurrent Chromatography

    Science.gov (United States)

    Ito, Yoichiro; Knight, Martha; Finn, Thomas M.

    2013-01-01

    For many years, high-speed countercurrent chromatography conducted in open tubing coils has been widely used for the separation of natural and synthetic compounds. In this method, the retention of the stationary phase is solely provided by the Archimedean screw effect by rotating the coiled column in the centrifugal force field. However, the system fails to retain enough of the stationary phase for polar solvent systems such as the aqueous–aqueous polymer phase systems. To address this problem, the geometry of the coiled channel was modified to a spiral configuration so that the system could utilize the radially acting centrifugal force. This successfully improved the retention of the stationary phase. Two different types of spiral columns were fabricated: the spiral disk assembly, made by stacking multiple plastic disks with single or four interwoven spiral channels connected in series, and the spiral tube assembly, made by inserting the tetrafluoroethylene tubing into a spiral frame (spiral tube support). The capabilities of these column assemblies were successfully demonstrated by separations of peptides and proteins with polar two-phase solvent systems whose stationary phases had not been well retained in the earlier multilayer coil separation column for high-speed countercurrent chromatography. PMID:23833207

  3. Enantioseparation of DL-tryptophan by spiral tube assembly counter-current chromatography and evaluation of mass transfer rate for enantiomers

    Science.gov (United States)

    Tong, Shengqiang; Ito, Yoichiro; Ma, Ying

    2014-01-01

    Spiral tube assembly counter-current chromatography was successfully applied in enantioseparation of DL-tryptophan using bovine serum albumin as chiral selector. An improved biphasic aqueous-aqueous solvent system 12.0% (w/w) polyethyleneglycol 8000–9.0% (w/w) dibasic potassium phosphate-0.1% ammonia-78.9% water was used as the solvent system for counter-current chromatography, in which bovine serum albumin was predominantly distributed in the lower phase of the two-phase aqueous system. The aqueous-aqueous solvent system gave a very high enantioselectivity for D- and L-tryptophan at α=2.605 along with distribution ratio DD=1.200 and DL=0.461. High peak resolution was obtained for enantioseparation of 2.0 mg of DL-tryptophan by spiral tube assembly counter-current chromatography under room temperature. It was found that 0.1% ammonia added in the aqueous-aqueous solvent system greatly improved the enantioseparations. An unusual extremely broad peak for L-tryptophan was observed during enantioseparations. In order to give an explanation, mass transfer rates of D- and L-enantiomers through the interface between the two phases were measured. It was found that L-tryptophan showed lower mass transfer rate than D-tryptophan. Further discussions were proposed for possible reasons for mass transfer rate difference between the enantiomers. PMID:25476690

  4. Experimental results for an experimental condensation heat exchanger with a spiral minichanel tube. Comparison to numerical imulations

    Directory of Open Access Journals (Sweden)

    Hrubý J.

    2013-04-01

    Full Text Available The paper describes new results for an experimental heat exchanger equipped with a single corrugated capillary tube, basic information about the measurements and the experimental setup. Some of the results were compared with numerical simulations.

  5. FLUTE - File Delivery over Unidirectional Transport

    OpenAIRE

    Paila, Toni; Walsh, Rod; Luby, Michael; Roca, Vincent; Lehtonen, Rami

    2012-01-01

    Internet Engineering Task Force (IETF) Request for Comments: 6726; This document defines File Delivery over Unidirectional Transport (FLUTE), a protocol for the unidirectional delivery of files over the Internet, which is particularly suited to multicast networks. The specification builds on Asynchronous Layered Coding, the base protocol designed for massively scalable multicast distribution. This document obsoletes RFC 3926.

  6. Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch

    Energy Technology Data Exchange (ETDEWEB)

    May, Matthias S.; Kuettner, Axel; Lell, Michael M.; Wuest, Wolfgang; Scharf, Michael; Uder, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany); Deak, Paul; Kalender, Willi A. [University of Erlangen, Department of Medical Physics, Erlangen (Germany); Keller, Andrea K.; Haeberle, Lothar [University of Erlangen, Department of Medical Informatics, Biometry and Epidemiology, Erlangen (Germany); Achenbach, Stephan; Seltmann, Martin [University of Erlangen, Department of Cardiology, Erlangen (Germany)

    2012-03-15

    To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine. Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation. Estimates for mean relative ED was 7.1 {+-} 2.1 mSv/100 mAs for TCM and 12.5 {+-} 5.3 mSv/100 mAs for CTC (P < 0.001). Relative dose reduction at low HR ({<=}60 bpm) was highest (49 {+-} 5%) compared to intermediate (60-70 bpm, 33 {+-} 12%) and high HR (>70 bpm, 29 {+-} 12%). However lowest ED is achieved at high HR (5.2 {+-} 1.5 mSv/100 mAs), compared with intermediate (6.7 {+-} 1.6 mSv/100 mAs) and low (8.3 {+-} 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied. Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM. circle Monte Carlo simulations allow for individual radiation dose calculations. (orig.)

  7. Intra-individual diagnostic image quality and organ-specific-radiation dose comparison between spiral cCT with iterative image reconstruction and z-axis automated tube current modulation and sequential cCT

    International Nuclear Information System (INIS)

    Wenz, Holger; Maros, Máté E.; Meyer, Mathias; Gawlitza, Joshua; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O.; Groden, Christoph; Henzler, Thomas

    2016-01-01

    •Superiority of spiral versus sequential cCT in image quality and organ-specific-radiation dose.•Spiral cCT: lower organ-specific-radiation-dose in eye lense compared to tilted sequential cCT.•State-of-the-art IR spiral cCT techniques has significant advantages over sequential cCT techniques. Superiority of spiral versus sequential cCT in image quality and organ-specific-radiation dose. Spiral cCT: lower organ-specific-radiation-dose in eye lense compared to tilted sequential cCT. State-of-the-art IR spiral cCT techniques has significant advantages over sequential cCT techniques. To prospectively evaluate image quality and organ-specific-radiation dose of spiral cranial CT (cCT) combined with automated tube current modulation (ATCM) and iterative image reconstruction (IR) in comparison to sequential tilted cCT reconstructed with filtered back projection (FBP) without ATCM. 31 patients with a previous performed tilted non-contrast enhanced sequential cCT aquisition on a 4-slice CT system with only FBP reconstruction and no ATCM were prospectively enrolled in this study for a clinical indicated cCT scan. All spiral cCT examinations were performed on a 3rd generation dual-source CT system using ATCM in z-axis direction. Images were reconstructed using both, FBP and IR (level 1–5). A Monte-Carlo-simulation-based analysis was used to compare organ-specific-radiation dose. Subjective image quality for various anatomic structures was evaluated using a 4-point Likert-scale and objective image quality was evaluated by comparing signal-to-noise ratios (SNR). Spiral cCT led to a significantly lower (p < 0.05) organ-specific-radiation dose in all targets including eye lense. Subjective image quality of spiral cCT datasets with an IR reconstruction level 5 was rated significantly higher compared to the sequential cCT acquisitions (p < 0.0001). Consecutive mean SNR was significantly higher in all spiral datasets (FBP, IR 1–5) when compared to sequential cCT with a mean

  8. Logarithmic Spiral

    Indian Academy of Sciences (India)

    anti-clockwise direction and we get a right-handed spiral. (Figure 2). We know that the derivative of eX is also eX. Various properties of logarithmic spiral depend on this property of eX. Properties of Logarithmic Spiral. 1. The most important property of a logarithmic spiral is that r (i.e. the distance from the origin) increases.

  9. On the Fully-Developed Heat Transfer Enhancing Flow Field in Sinusoidally, Spirally Corrugated Tubes Using Computational Fluid Dynamics

    DEFF Research Database (Denmark)

    Hærvig, Jakob; Sørensen, Kim; Condra, Thomas Joseph

    2017-01-01

    in the ranges 0–0.16 and 0–2.0 respectively. The 3D Unsteady Reynolds-averaged Navier–Stokes (URANS) equations combined with the transition SST turbulence model are solved using the finite volume method to obtain the fully-developed flow field in a repeatable section of the heat exchangers at a constant wall...... loss. To assess the performance as a heat exchanger, the ratio of enhanced Nusselt number to enhanced friction factor η=(Nu/Nu_s)/(f/f_s)^(1/3) compared to the non-corrugated tube is used. Using this parameter, the simulations show a decrease in performance at higher corrugation heights. To link...... the detailed flow fields to the performance as a heat exchanger, non-dimensional correlations for heat transfer, pressure loss, and performance parameter are given....

  10. Heat transfer and critical heat flux in a spiral flow in an asymmetrical heated tube; Transfert thermique et flux critique dans un ecoulement helicoidal en tube chauffe asymetriquement

    Energy Technology Data Exchange (ETDEWEB)

    Boscary, J. [CEA Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Direction des Sciences de la Matiere]|[Association Euratom-CEA, Centre d`Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    1997-03-01

    The design of plasma facing components is crucial for plasma performance in next fusion reactors. These elements will be submitted to very high heat flux. They will be actively water-cooled by swirl tubes in the subcooled boiling regime. High heat flux experiments were conducted in order to analyse the heat transfer and to evaluate the critical heat flux. Water-cooled mock-ups were one-side heated by an electron beam gun for different thermal-hydraulic conditions. The critical heat flux was detected by an original method based on the isotherm modification on the heated surface. The wall heat transfer law including forced convection and subcooled boiling regimes was established. Numerical calculations of the material heat transfer conduction allowed the non-homogeneous distribution of the wall temperature and of the wall heat flux to be evaluated. The critical heat flux value was defined as the wall maximum heat flux. A critical heat flux model based on the liquid sublayer dryout under a vapor blanket was established. A good agreement with test results was found. (author) 197 refs.

  11. Reinvigorating the indigenous flute in African dance performance ...

    African Journals Online (AJOL)

    This article examines the place of the indigenous African flute as an instrument of communication in dance performance. In doing this, it attempts to explore the usefulness of flute in encouraging vocational and entrepreneurial skills among the youth, with a view to creating job opportunities. Over the decades, scholars and ...

  12. Effects of Climate Change on Fluted Pumpkin Production and ...

    African Journals Online (AJOL)

    The importance of fluted pumpkin crop in rural household economy cannot be over emphasized. Farmers in the South South Nigeria depend greatly on fluted pumpkin for its many uses. The production however is beset with a myriad of constraints of which climate change is one of the most outstanding. The study assessed ...

  13. Spiral symmetry

    CERN Document Server

    Hargittai, Istvan

    1992-01-01

    From the tiny twisted biological molecules to the gargantuan curling arms of many galaxies, the physical world contains a startling repetition of spiral patterns. Today, researchers have a keen interest in identifying, measuring, and defining these patterns in scientific terms. Spirals play an important role in the growth processes of many biological forms and organisms. Also, through time, humans have imitated spiral motifs in their art forms, and invented new and unusual spirals which have no counterparts in the natural world. Therefore, one goal of this multiauthored book is to stress the c

  14. Jolivet: Complete Flute Music, Vol. 2 / Guy S. Rickards

    Index Scriptorium Estoniae

    Rickards, Guy S.

    1996-01-01

    Uuest heliplaadist "Jolivet: Complete Flute Music, Vol. 2. Kroumata Percussion Ensemble, Tapiola Sinfonietta, Paavo Järvi". BIS CD 739 (64 minutes: DDD). Item marked from CD630 (6/94), CD272, remainder new to UK

  15. Properties of spiral resonators

    International Nuclear Information System (INIS)

    Haeuser, J.

    1989-10-01

    The present thesis deals with the calculation and the study of the application possibilities of single and double spiral resonators. The main aim was the development and the construction of reliable and effective high-power spiral resonators for the UNILAC of the GSI in Darmstadt and the H - -injector for the storage ring HERA of DESY in Hamburg. After the presentation of the construction and the properties of spiral resonators and their description by oscillating-circuit models the theoretical foundations of the bunching are presented and some examples of a rebuncher and debuncher and their influence on the longitudinal particle dynamics are shown. After the description of the characteristic accelerator quantities by means of an oscillating-circuit model and the theory of an inhomogeneous λ/4 line it is shown, how the resonance frequency and the efficiency of single and double spiral resonators can be calculated from the geometrical quantities of the structure. In the following the dependence of the maximal reachable resonator voltage in dependence on the gap width and the surface of the drift tubes is studied. Furthermore the high-power resonators are presented, which were built for the different applications for the GSI in Darmstadt, DESY in Hamburg, and for the FOM Institute in Amsterdam. (orig./HSI) [de

  16. Evaluation of Analysis Techniques for Fluted-Core Sandwich Cylinders

    Science.gov (United States)

    Lovejoy, Andrew E.; Schultz, Marc R.

    2012-01-01

    Buckling-critical launch-vehicle structures require structural concepts that have high bending stiffness and low mass. Fluted-core, also known as truss-core, sandwich construction is one such concept. In an effort to identify an analysis method appropriate for the preliminary design of fluted-core cylinders, the current paper presents and compares results from several analysis techniques applied to a specific composite fluted-core test article. The analysis techniques are evaluated in terms of their ease of use and for their appropriateness at certain stages throughout a design analysis cycle (DAC). Current analysis techniques that provide accurate determination of the global buckling load are not readily applicable early in the DAC, such as during preliminary design, because they are too costly to run. An analytical approach that neglects transverse-shear deformation is easily applied during preliminary design, but the lack of transverse-shear deformation results in global buckling load predictions that are significantly higher than those from more detailed analysis methods. The current state of the art is either too complex to be applied for preliminary design, or is incapable of the accuracy required to determine global buckling loads for fluted-core cylinders. Therefore, it is necessary to develop an analytical method for calculating global buckling loads of fluted-core cylinders that includes transverse-shear deformations, and that can be easily incorporated in preliminary design.

  17. A Little Flute Music: Mimicry, Memory, and Narrativity

    Directory of Open Access Journals (Sweden)

    Vicki Powys

    2013-11-01

    Full Text Available A lyrebird chick was raised in captivity in the 1920s in Australia’s New England Tablelands, or so the story goes. The bird mimicked the sounds of the household’s flute player, learning two tunes and an ascending scale. When released back into the wild, his flute-like songs and timbre spread throughout the local lyrebird population. We count ourselves among those who admire the sonic achievements of this bioregion’s “flute lyrebirds.” These Superb Lyrebirds (Menura novaehollandiae do indeed deliver an unusual and extraordinarily complex, flute-like territorial song, although often with a musical competence exceeding what a human flutist could achieve. In this paper, we engage with both the living and the dead across a wide-ranging cast of characters, linking up in the here and now and grasping a hand across the span of many years. Memory and narrativity are pertinent to the at times conflicting stories and reminiscences from archival and contemporary sources. Ultimately, accounts of “flute lyrebirds” speak to how meaning evolves in the tensions, boundaries, and interplay between knowledge and imagination. We conclude that this story exceeds containment, dispersed as it is across several fields of inquiry and a number of individual memories that go in and out of sync.

  18. 77 FR 60803 - Endangered and Threatened Wildlife and Plants; Endangered Species Status for the Fluted...

    Science.gov (United States)

    2012-10-04

    ... infest potential host fishes. Fluted kidneyshell conglutinates are shaped like black fly (Simuliidae... the Clinch River is a population of the fluted kidneyshell known to be large, stable, and viable, but...

  19. Eccentric-fluted beam pipes to damp quadrupole higher-order modes

    Directory of Open Access Journals (Sweden)

    M. Sawamura

    2010-02-01

    Full Text Available An eccentric-fluted beam pipe is proposed to damp quadrupole modes in a cavity. The eccentric flutes act as a mode converter from quadrupole to dipole. Optimizing the parameters of the eccentric-fluted beam pipe allows sufficient damping of both degenerate quadrupole modes. The external Q values of the eccentric-fluted beam pipe measured with a low power model cavity agree well with those calculated with the 3D electromagnetic field simulation code MAFIA.

  20. Eccentric-fluted beam pipes to damp quadrupole higher-order modes

    Science.gov (United States)

    Sawamura, M.; Furuya, T.; Sakai, H.; Takahashi, T.; Umemori, K.; Shinoe, K.

    2010-02-01

    An eccentric-fluted beam pipe is proposed to damp quadrupole modes in a cavity. The eccentric flutes act as a mode converter from quadrupole to dipole. Optimizing the parameters of the eccentric-fluted beam pipe allows sufficient damping of both degenerate quadrupole modes. The external Q values of the eccentric-fluted beam pipe measured with a low power model cavity agree well with those calculated with the 3D electromagnetic field simulation code MAFIA.

  1. Effects of diameter and helical angle of flute on the flow evenness of ...

    African Journals Online (AJOL)

    In this study, the optimum dimensions of flute diameter and helical angle of fluted roller used in seed drills were determined for lentil seeds at 100 kg ha-1 of seed rate. The values of coefficient variation were used to determine the optimum dimensions of fluted rollers. The best rates of flow evenness and the minimum ...

  2. Finite Larmor radius flute mode theory with end loss

    Energy Technology Data Exchange (ETDEWEB)

    Kotelnikov, I.A. [AN SSSR, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Berk, H.L. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies

    1993-08-01

    The theory of flute mode stability is developed for a two-energy- component plasma partially terminated by a conducting limiter. The formalism is developed as a preliminary study of the effect of end-loss in open-ended mirror machines where large Larmor radius effects are important.

  3. Microproagation of Fluted pumkin by Enhanced Axilary shoot ...

    African Journals Online (AJOL)

    In a bid to develop protocols for micropropagation of fluted pumkin (Telfairia occidentalis), single node cuttings of two genotypes, Telfairia occidentalis white and Telfairia occidentalis orange (ToW-1 and ToR-1 respectively) were cultured in Murashige and Skoog medium but with four different combinations of kinetin and ...

  4. Effects of processing on the nutritional composition of fluted pumpkin ...

    African Journals Online (AJOL)

    Fluted pumpkin seeds were processed into the raw, boiled, fermented, germinated and roasted seeds, dried at 500C, milled and sieved. The seed flours were analyzed for nutritional composition, energy, amino acids and fatty acids of the oils. Processing affected the levels of nutrients in the seed. The energy values ranged ...

  5. Growth response of fluted pumpkin ( Telfairia occidentalis Hook . F ...

    African Journals Online (AJOL)

    An investigation of the growth response of fluted pumpkin to different combinations of irrigation intervals and spent mushroom substrate (SMS) was conducted during the dry season, with a view to determining the combination that would give the best performance of the crop. The experiment lasted for a period of thirteen ...

  6. Pre-School Children's Encounters with "The Magic Flute"

    Science.gov (United States)

    Nyland, Berenice; Acker, Aleksandra; Ferris, Jill; Deans, Jan

    2011-01-01

    This article describes a music programme in an Australian early learning centre. Through a repertoire of songs, games and instruments, the children were introduced to music forms, including opera. Mozart's Magic Flute was presented to these children by watching the Metropolitan Opera's latest film performance. Because this opera seized the…

  7. Residual Effect of Chromium on Early Growth of Fluted Pumpkin ...

    African Journals Online (AJOL)

    These greenhouse and field trials were aimed at determining the residual influence of Cr on some agronomic characters, nutrient content, nutrient uptake and crude protein content of fluted pumpkin in soils previously treated with 0, 50, 100, 200 mg Cr(NO3). .9H2O per 5 kg soil in the greenhouse and 0, 20, 40, 80 kgha-1 Cr ...

  8. Performance of broiler chickens served heat-treated fluted pumpkin ...

    African Journals Online (AJOL)

    One hundred and twenty five day-old chicks of Anak 2000 were weighed and randomly distributed to five dietary treatments A, B, C, D and E which contained no FPLE (control), fluted pumpkin leaves (FPL) no heat treatment, FPL immersed in hot water (100°C) for 1, 3 and 5 min, respectively. Each treatment was replicated 3 ...

  9. Influence of crude extract of root of Telfairia occidentalis (fluted ...

    African Journals Online (AJOL)

    The effect of crude extract of root of Telfairia occidentalis (fluted pumpkin) was investigated on the kidney of adult wistar rats. The crude extract of pumpkin root were given both intraperitoneally and orally to rats respectively. The control group received distilled water throughout the duration of experiment. The administration ...

  10. The spiral

    DEFF Research Database (Denmark)

    Bibace, Roger; Kharlamov, Nikita

    2013-01-01

    ’s work with Bernard Kaplan on symbol formation is a primer on this idea. This paper examines the idea of spirality and develops the notion of dynamic coexistence that can clarify the issue of directionality of development; that is, what is the general trajectory or ground plan that development assumes....... Directionality is discussed in terms of the organism-in-environment unfolding over time as the unit of developmental analysis. Thinking on this issue has proceeded from the nature–nurture debates, to recognition of the interaction of external and internal processes, to transactions between the organism...

  11. Investigation on hole manufacture in 42CrMo4 steel using 3-flute carbide drills and 6-flute cermet reamers

    DEFF Research Database (Denmark)

    Müller, Pavel; De Chiffre, Leonardo

    2009-01-01

    An investigation on cutting forces and hole quality using carbide 3-flute self-centering drills and 6-flute cermet reamers was performed on 42CrMo4 alloy steel. Different depths of cuts were analyzed with respect to cutting thrust and cutting torque, hole diameter, form and surface integrity. Goo...

  12. Spiral tectonics

    Science.gov (United States)

    Hassan Asadiyan, Mohammad

    2014-05-01

    Spiral Tectonics (ST) is a new window to global tectonics introduced as alternative model for Plate Tectonics (PT). ST based upon Dahw(rolling) and Tahw(spreading) dynamics. Analogues to electric and magnetic components in the electromagnetic theory we could consider Dahw and Tahw as components of geodynamics, when one component increases the other decreases and vice versa. They are changed to each other during geological history. D-component represents continental crust and T-component represents oceanic crust. D and T are two arm of spiral-cell. T-arm 180 degree lags behind D-arm so named Retard-arm with respect to D or Forward-arm. It seems primary cell injected several billions years ago from Earth's center therefore the Earth's core was built up first then mantel and finally the crust was build up. Crust building initiate from Arabia (Mecca). As the universe extended gravitation wave swirled the earth fractaly along cycloid path from big to small scale. In global scale (order-0) ST collect continents in one side and abandoned Pacific Ocean in the other side. Recent researches also show two mantels upwelling in opposite side of the Earth: one under Africa (tectonic pose) and the other under Pacific Ocean (tectonic tail). In higher order (order-1) ST build up Africa in one side and S.America in the other side therefore left Atlantic Ocean meandered in between. In order-n e.g. Khoor Musa and Bandar-Deylam bay are seen meandered easterly in the Iranian part but Khoor Abdullah and Kuwait bay meandered westerly in the Arabian part, they are distributed symmetrically with respect to axis of Persian Gulf(PG), these two are fractal components of easterly Caspian-wing and westerly Black Sea-wing which split up from Anatoly. Caspian Sea and Black Sea make two legs of Y-like structure, this shape completely fitted with GPS-velocity map which start from PG and split up in the Catastrophic Point(Anatoly). We could consider PG as remnants of Ancient Ocean which spent up

  13. Innovative Field Investigations in Limestone using a FACT-FLUTe

    DEFF Research Database (Denmark)

    Mosthaf, Klaus; Barrett Sørensen, Mie; Broholm, Mette Martina

    2015-01-01

    from the Water-FLUTe multilevels (Janniche et al. 2013 and 2013b) at the site. Method and technique The FLUTe Activated Carbon Technique was described e.g. in Janniche et al. (2013). The sorption of chlorinated ethenes on activated carbon was determined in laboratory experiments as described...... in Sørensen et al. (2014) to obtain equilibrium sorption coefficients (Kd) for individual and mixed chlorinated ethenes on activated carbon from aqueous solution. As the uptake on FACT in limestone aquifers will depend on transport (advection and/or diffusion and retardation by sorption) in the limestone...... matrix and fractures as well as on the sorption to activated carbon, a modeling tool was developed (Mosthaf et al. 2014) which allows for the interpretation of field data and the analysis of the influence of various aquifer parameters. The model provides a link between sorbed concentrations on the FACT...

  14. The Development of the Flute as a Solo Instrument from the Medieval to the Baroque Era

    Directory of Open Access Journals (Sweden)

    Anna J. Reisenweaver

    2011-05-01

    Full Text Available As one of the oldest instruments known to mankind, the flute is present in some form in nearly every culture and ethnic group in the world. However, in Western music in particular, the flute has taken its place as an important part of musical culture, both as a solo and an ensemble instrument. The flute has also undergone its most significant technological developments in Western musical culture, moving from the bone keyless flutes of the Prehistoric era to the gold and silver instruments known to performers today. During the Renaissance and Baroque periods in particular, however, the flute rose to popularity as a solo instrument and began to evolve into its modern form. New developments in the design and mechanics of the instrument drove this increased interest, which ultimately gave the flute a prominent position in music that has lasted throughout history.

  15. Impact of Grinding Wheel Position on Flute Profile of End mill and Cutting Process

    Science.gov (United States)

    Zhidyaev, Alexey N.

    2018-01-01

    The article provides the research on flute profile of end mills. The flute profile of a specified end mill design is affected by grinding wheel position relative to end mill workpiece in grinding operation. Different profiles were obtained, their rake surfaces and cross section areas were compared. Temperatures and cutting forces were evaluated via finite element analysis for these profiles in case of titanium alloy and heat-resistant alloy machining. Finally, the impact of flute profile on cutting process was assessed.

  16. Modular Fluted Tapered Stems in Aseptic Revision Total Hip Arthroplasty.

    Science.gov (United States)

    Abdel, Matthew P; Cottino, Umberto; Larson, Dirk R; Hanssen, Arlen D; Lewallen, David G; Berry, Daniel J

    2017-05-17

    Modular fluted tapered stems have become the most commonly employed category of femoral component in revision hip arthroplasty in North America as a result of favorable early results and simplicity of use. Despite wide adoption, the majority of published data are limited to relatively small series with modest follow-up. The goal of the current study was to determine the success rate and factors associated with success, failure, and complications of the use of modular fluted tapered stems in aseptic revision total hip arthroplasties (THAs) in a large patient cohort. We identified 519 aseptic femoral revisions during which a modular fluted tapered stem was utilized. Clinical outcomes, Kaplan-Meier survivorship, radiographic outcomes, and complications were assessed. The mean age at revision arthroplasty was 70 years, the mean body mass index (BMI) was 29 kg/m, and the mean duration of follow-up was 4.5 years (range, 2 to 14 years). The mean Harris hip score (HHS) improved significantly from 51 points preoperatively to 76 points at 2 years (p revisions had been performed: 6 because of aseptic loosening, 4 because of infection, 3 because of instability, 2 because of periprosthetic fracture, and 1 because of stem fracture. The 10-year survivorship was 96% with revision for any reason as the end point and 90% with any reoperation as the end point. Of the patients who were alive and had not undergone revision at the time of final follow-up, 12 had stem subsidence but all but 1 of these stems had stabilized after subsiding. Postoperative complications were noted in 12% of the cases. Repeat revision due to femoral component loosening was not correlated with the preoperative bone-loss category or patient demographic factors. In this large series, femoral revision with a modular fluted tapered stem provided a high rate of osseointegration and sustained improvement in clinical scores at the time of the last follow-up. There was also a high rate of successful implant fixation

  17. Glacial flutings in bedrock, an observation in East Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1978-01-01

    and 5 m in height and occur between 50 and 250 m above sea level inthe gently sloping lowland area adjacent to the fjord. They were probably formed beneath the lateral part of the former Harefjord-Glacier which receded rapidly in the fjord and exposed the area at c. 7500 years BP. Large scale glacial...... flutings have not been recorded before in Greenland, but seem to be of common occurrence in parts of North America. They have probably been formed near the margin of actively moving glaciers, and secondary flow in the basal ice may have played an important role...

  18. The Spiral of Euroscepticism

    DEFF Research Database (Denmark)

    Galpin, Charlotte; Trenz, Hans-Jörg

    2017-01-01

    Media scholars have increasingly examined the effects of a negativity bias that applies to political news. In the ‘spiral of cynicism’, journalist preferences for negative news correspond to public demands for sensational news. We argue that this spiral of cynicism in EU news results in a ‘spiral...

  19. Experimental Study of the Compression Response of Fluted-Core Composite Panels with Joints

    Science.gov (United States)

    Schultz, Marc R.; Rose, Cheryl A.; Guzman, J. Carlos; McCarville, Douglas; Hilburger, Mark W.

    2012-01-01

    Fluted-core sandwich composites consist of integral angled web members spaced between laminate face sheets, and may have the potential to provide benefits over traditional sandwich composites for certain aerospace applications. However, fabrication of large autoclave-cured fluted-core cylindrical shells with existing autoclaves will require that the shells be fabricated in segments, and joined longitudinally to form a complete barrel. Two different longitudinal fluted-core joint designs were considered experimentally in this study. In particular, jointed fluted-core-composite panels were tested in longitudinal compression because longitudinal compression is the primary loading condition in dry launch-vehicle barrel sections. One of the joint designs performed well in comparison with unjointed test articles, and the other joint design failed at loads approximately 14% lower than unjointed test articles. The compression-after-impact (CAI) performance of jointed fluted-core composites was also investigated by testing test articles that had been subjected to 6 ft-lb impacts. It was found that such impacts reduced the load-carrying capability by 9% to 40%. This reduction is dependent on the joint concept, component flute size, and facesheet thickness.

  20. Triangular spiral tilings

    International Nuclear Information System (INIS)

    Sushida, Takamichi; Hizume, Akio; Yamagishi, Yoshikazu

    2012-01-01

    The topology of spiral tilings is intimately related to phyllotaxis theory and continued fractions. A quadrilateral spiral tiling is determined by a suitable chosen triple (ζ, m, n), where ζ element of D/R, and m and n are relatively prime integers. We give a simple characterization when (ζ, m, n) produce a triangular spiral tiling. When m and n are fixed, the admissible generators ζ form a curve in the unit disk. The family of triangular spiral tilings with opposed parastichy pairs (m, n) is parameterized by the divergence angle arg (ζ), while triangular spiral tilings with non-opposed parastichy pairs are parameterized by the plastochrone ratio 1/|ζ|. The generators for triangular spiral tilings with opposed parastichy pairs are not dense in the complex parameter space, while those with non-opposed parastichy pairs are dense. The proofs will be given in a general setting of spiral multiple tilings. We present paper-folding (origami) sheets that build spiral towers whose top-down views are triangular tilings. (paper)

  1. Flute and Shank Dimensions of Reciprocating Instruments before and after Simulated Root Canal shaping.

    Science.gov (United States)

    Sampaio, Felipe C; Brito, Ana Pp; Veloso, Heloisa Hp; de Alencar, Ana Hg; Decurcio, Daniel de A; de Figueiredo, José Ap; Estrela, Carlos

    2017-03-01

    This study analyzed the effect of the dimensions of the flute and shank in the first 4 mm of instrument tips on the deformation and dimensional changes of reciprocating instruments after root canal shaping (RCS). The reciprocating instruments used were Reciproc ® R25, R40, and R50; WaveOne ® Small, Primary, and Large; and Unicone ® #20, #25, and #40. Scanning electron microscopy images of the first 4 mm of the tip were acquired at 30× magnification before and after simulated curved root canals were shaped. Each instrument was used only once. The images were transferred to the AxioVision ® software to measure the flute area (μm 2 ), shank area (μm 2 ), flute length (μm), and cross-sectional diameter (μm). Student's t test for paired samples was used to compare differences before and after RCS, and analysis of variance followed by the Tukey test, to compare differences between instruments of similar sizes. The instruments were classified according to deformations after RCS. Reciproc ® instruments had larger flutes and smaller shanks. The Reciproc ® R40 had significant differences in cross-sectional diameter at 0.5 mm from the tip. Reciproc ® had no plastic deformations. Unicone ® #20 instruments had significant differences in cross-sectional diameter at 1.5 and 3.0 mm from the tip, and #25 instruments had differences at 1.5 and 3.0 mm and in length of the second and third flutes. One #20 and three #40 instruments had plastic deformations. The differences in length of the first and fourth flutes of WaveOne ® Primary and in cross-sectional diameter at 2.0 mm from the tip of WaveOne ® Large were significant. Two of three WaveOne ® Large instruments had plastic deformations. Reciproc ® instruments had greater flute areas and lengths and smaller shanks than Unicone ® and WaveOne ® instruments of similar sizes. Reciproc ® instruments had a greater flute-to-shank ratio. WaveOne ® instruments had the lowest flute-to-shank ratio. Unicone ® instruments

  2. Surface flute modes in the bumpy magnetic field

    International Nuclear Information System (INIS)

    Girka, I.O.; Girka, V.O.; Lapshin, V.I.

    2005-01-01

    Surface electromagnetic waves are often determined as the most possible cause of undesirable heating of edge plasma that leads, in turn, to strengthening of plasma - wall interaction in stellarators and increased plasma contamination. The propagation of surface flute modes near the interface of plasma column separated by a vacuum layer from the ring cylindrical ideally conductive metallic chamber is studied. The external steady bumpy magnetic field B-vector 0 = B 0z e-vector z + B 0r e-vector r was considered, B 0z =B 00 [1+ε m (r)cos(k m z)], here ε m '≡dε m /dr, k m =2π/L, L is the period of nonuniformity. non-uniformity of B-vector 0 is planned to be dominant in the confining magnetic field of the modular stellarator Helias, ε m ∼ 0.13. In the bumpy magnetic field the electromagnetic disturbance propagates in the form of the wave envelope, in which one alongside with the fundamental harmonic, proportional to exp[i(mθ±-ωt)], infinite set of satellite spatial harmonics, proportional to exp[i(mθ ± jk m z - ωt)], j=1,2,3..., is present. It is shown, that in the first approximation in the respect to ε m , amplitudes of the fundamental harmonics of the E-wave with the field components E r , E θ , B z do not vary, small satellite harmonics of these fields arise, proportional to exp[i(mθ ± k m z - ωt)]. At the same time due to weak coupling of - and - modes, caused by B-vector 0 nonuniformity and nonzero axial wave number of satellite harmonics, small satellite harmonics of H-wave with the field components E z , B r , B θ also arise. The amplitudes of satellite harmonics of E-wave are shown to be symmetric: E r (+) =E r (-) , E θ (+) =E θ (-) , B z (+) =B z (-) , and the amplitudes of H-wave are antisymmetric: B r (+) =-B r (-) , B θ (+) =- B θ (-) , E z (+) =-E z (-) . In the second approximation in the respect to ε m corrections to the amplitudes of the fundamental harmonic of E-wave arise. The correction to the eigen frequency of the wave

  3. Lung studies with spiral CT. pitch 1 versus pitch 2

    International Nuclear Information System (INIS)

    Sartoni Galloni, S.; Miceli, M.; Lipparino, M.; Burzi, M.; Gigli, F.; Rossi, M.S.; Santoli, G.; Guidarelli, G.

    1999-01-01

    In Spiral CT, the pitch is the ratio of the distance to tabletop travels per 360 degrees rotation to nominal slice width, expressed in mm. Performing Spiral CT examination with pitch 2 allows to reduce examination time, exposure and contrast dose, and X-ray tube overload. The authors investigated the yield of pitch 2 in lung parenchyma studies, particular relative to diagnostic image quality [it

  4. Flute ``breath support'' perception and its acoustical correlates

    Science.gov (United States)

    Cossette, Isabelle A.; Sabourin, Patrick

    2004-05-01

    Music educators and performers commonly refer to ``breath support'' in flute playing, yet the term ``support'' is neither well-defined nor consistently used. Different breathing strategies used by professional flautists who were instructed to play with and without support were previously identified by the authors. In the current study, 14 musical excerpts with and without support were recorded by five professional flautists. Eleven professional flautists listened to the recordings in a random order and ranked (1 to 6) how much of the following sound qualities they judged to be in each example: support, intonation, control and musical expressiveness. Answers to the test showed that musical expressiveness was associated more closely with the supported excerpts than the answers about support itself. The ratings for each sound quality were highly intercorrelated. Acoustical parameters were analyzed (frequency and centroid variation within each note) and compared with the results of the perception test in order to better understand how the acoustical and psychological variables were related. The acoustical analysis of the central part of the notes did not show evident correlation with the answers of the perception test. [Work funded by the Social Sciences and Humanities Research Council of Canada.

  5. Flute instability growth on a magnetized plasma column

    International Nuclear Information System (INIS)

    Rose, D. V.; Genoni, T. C.; Welch, D. R.; Mehlhorn, T. A.; Porter, J. L.; Ditmire, T.

    2006-01-01

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r i , where R is the Gaussian characteristic radius and r i is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation

  6. Spiral finned crucible pot

    Science.gov (United States)

    Soemowidagdo, Arianto Leman; Tiwan, Widarto, Ardian, Aan

    2018-02-01

    Innovation on a crucible furnace to increase its efficiency in aluminum melting has been done. The innovation was a spiral finned crucible pot. The inclination of the spiral finned was vary of 5, 10, 15, and 20 degrees. The spiral finned effects was determined from the performance test result. A crucible pot without fin was also tested as a control. The crucible pot was examined at the same process condition. The crucible pot with the inclined fin of 10 degrees gives an optimum performance. It gives effective heating rate so that more efficient in LPG consumption. Therefore it saves energy in the aluminum melting process.

  7. Spiral 2 Week

    International Nuclear Information System (INIS)

    2007-01-01

    The main goal of this meeting is to present and discuss the current status of the Spiral-2 project at GANIL in front of a large community of scientists and engineers. Different issues have been tackled particularly the equipment around Spiral-2 like injectors, cryo-modules or beam diagnostics, a workshop was devoted to other facilities dedicated to radioactive ion beam production. This document gathers only the slides of the presentations

  8. Spiral 2 Week

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The main goal of this meeting is to present and discuss the current status of the Spiral-2 project at GANIL in front of a large community of scientists and engineers. Different issues have been tackled particularly the equipment around Spiral-2 like injectors, cryo-modules or beam diagnostics, a workshop was devoted to other facilities dedicated to radioactive ion beam production. This document gathers only the slides of the presentations.

  9. Development and Performance Evaluation of Fluted Pumpkin Seed Dehulling Machine

    Directory of Open Access Journals (Sweden)

    M. M. Odewole

    2017-08-01

    Full Text Available A machine for dehulling fluted pumpkin seed (Telfairia occidentalis was developed. The main objective of developing the machine was to provide a better substitute to traditional methods of dehulling the seed which contains edible oil of high medicinal and nutritional values. Traditional methods are full of drudgery, slow, injury prone and would lead to low and poor outputs in terms of quantity and quality of dehulled products. The machine is made of five major parts: the feed hopper (for holding the seeds to be dehulled before getting into the dehulling chamber, dehulling chamber (the part of the machine that impacts forces on seeds thereby causing fractures and opening of seeds coats for the delivery of the oily kernels, discharge unit (exit for oily kernels and seed coats after dehulling, the frame (for structural support and stability of all parts of the machine and electric motor (power source of the machine.The development process involved design of major components (shaft diameter (20 mm, machine velocity (7.59 m/s, power requirement (3hp single phase electric motor and structural support of mild steel angle iron, selection of construction materials and fabrication. ANSYS R14.5 machine design computer software was used to design the shaft and structural support; while other components were designed with conventional design method of using design equations. The machine works on the principle of centrifugal and impact forces. Performance evaluation was carried out after fabrication and 87.26%, 2.83g/s, 8.9% and 3.84%were obtained for dehulling efficiency, throughput capacity, percentage partially dehulled and percentage undehulled respectively.

  10. Plasma Generator Using Spiral Conductors

    Science.gov (United States)

    Szatkowski, George N. (Inventor); Dudley, Kenneth L. (Inventor); Ticatch, Larry A. (Inventor); Smith, Laura J. (Inventor); Koppen, Sandra V. (Inventor); Nguyen, Truong X. (Inventor); Ely, Jay J. (Inventor)

    2016-01-01

    A plasma generator includes a pair of identical spiraled electrical conductors separated by dielectric material. Both spiraled conductors have inductance and capacitance wherein, in the presence of a time-varying electromagnetic field, the spiraled conductors resonate to generate a harmonic electromagnetic field response. The spiraled conductors lie in parallel planes and partially overlap one another in a direction perpendicular to the parallel planes. The geometric centers of the spiraled conductors define endpoints of a line that is non-perpendicular with respect to the parallel planes. A voltage source coupled across the spiraled conductors applies a voltage sufficient to generate a plasma in at least a portion of the dielectric material.

  11. The spinning ball spiral

    Science.gov (United States)

    Dupeux, Guillaume; Le Goff, Anne; Quéré, David; Clanet, Christophe

    2010-09-01

    We discuss the trajectory of a fast revolving solid ball moving in a fluid of comparable density. As the ball slows down owing to drag, its trajectory follows an exponential spiral as long as the rotation speed remains constant: at the characteristic distance L where the ball speed is significantly affected by the drag, the bending of the trajectory increases, surprisingly. Later, the rotation speed decreases, which makes the ball follow a second kind of spiral, also described in the paper. Finally, the use of these highly curved trajectories is shown to be relevant to sports.

  12. Quarkyonic Chiral Spirals

    International Nuclear Information System (INIS)

    Toru, Kojo; Hidaka, Y.; Pisarski, R.; McLerran, L.

    2010-01-01

    We argue the properties of confining dense quark matter, 'quarkyonic' matter, from the viewpoint of both bulk properties and excitation modes. After a brief review of confining aspects, the chiral breaking/restoration will be discussed. We argue that the strong infrared correlations induce the chiral spiral, i.e., the spatial modulation of the chiral condensate which breaks the chiral symmetry locally but restore it globally. The effective dimensional reduction takes place, allowing us to analyzing the system as 2D model in which several exact results can be explicitly derived. We also discuss the excitation spectra, both mesonic and baryonic ones, on the chiral spiral. (author)

  13. 78 FR 59555 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Fluted...

    Science.gov (United States)

    2013-09-26

    ... concurred with our conclusions and provided additional information on taxonomic classification, life history... demonstrates strong habitat specificity. It is associated with faster flows, greater baseflow shear stress, and... stress is relatively low, although the fluted kidneyshell is more tolerant of shear stress than other...

  14. 78 FR 59269 - Endangered and Threatened Wildlife and Plants; Endangered Species Status for the Fluted...

    Science.gov (United States)

    2013-09-26

    ...) are moderately inflated. A series of flutings (parallel ridges or grooves) characterizes the posterior... for the District of Columbia Circuit has recently spoken to these issues. Safari Club International... the District of Columbia Circuit affirmed the District Court's holding that Safari Club International...

  15. Anvendelse af Water FLUTe multi-level vandprøvetagning til DNAPL-karakterisering

    DEFF Research Database (Denmark)

    Janniche, Gry Sander; Kerrn-Jespersen, Henriette; Christensen, Anders G.

    2013-01-01

    Denne artikel omhandler erfaringer med anvendelse af en ny metode, Water FLUTe til niveauspecifik vandprøvetagning i fm. karakterisering af DNAPL i et kalkmagasin. Metoden blev anvendt i et samarbejdsprojekt mellem DTU Miljø og Region Hovedstaden om afprøvning af metoder til bestemmelse af DNAPL...

  16. Observations on in vitro behaviour of the zygotic axes of fluted ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-08-03

    Aug 3, 2006 ... In order to facilitate this, the behaviour of excised embryonic axes and shoot tips of fluted pumpkin under in vitro conditions were investigated. Systemic infection of seeds from field led to frequent and high microbial contamination in culture. There was interaction between the type of microbial contamination ...

  17. Effect of organic and inorganic fertilizer on growth and yield of fluted ...

    African Journals Online (AJOL)

    PAT

    ABSTRACT. Field trails were conducted during 2009 and 2010 farming seasons at University of Uyo. Teaching and Research Farm, to asses the effect of organic and inorganic fertilizers on growth and yield of fluted pumpkin (Telfaria occidentalis). A randomized complete block design was used with three replicates.

  18. Observations on in vitro behaviour of the zygotic axes of fluted ...

    African Journals Online (AJOL)

    Fluted pumpkin, Telfairia occidentalis Hook. f., is an important leaf and seed vegetable and a local medicinal plant across West Africa. Many biological constraints have become potent threats to the existence of the plant necessitating an urgent need to collect and conserve the existing narrow genetic diversity. However ...

  19. Idea Bank: The Native American Flute--A Possibility for Your Classroom

    Science.gov (United States)

    Kacanek, Hal

    2011-01-01

    The sound of the Native American flute seems to convey care, sadness, loneliness, longing, heartfelt emotion, a sense of the natural world, wisdom, the human spirit, and a sense of culture. It is a sound that competes for attention, dramatically punctuating messages about First Nation peoples on television and in movies. A relatively small group…

  20. Implications of Y-fluting microstructures in zircaloy stress-corrosion fracture and analogous systems

    International Nuclear Information System (INIS)

    Banks, T.M.; Garlick, A.

    1982-01-01

    Transgranular cleavage is an important mode of crack propagation during stress-corrosion cracking (SCC) of Zircaloy in iodine vapour; and another characteristic feature is the presence of parallel closely spaced ridges. These are often referred to as Y-flutings because each ridge takes the form of an inverted Y when viewed along the direction of crack growth. The flutings are shown here to be formed by localised ductile parting of the Zircaloy near the tips of cleavage cracks; high mechanical constraints in those regions and the limited number of available slip systems result in the formation of a planar array of parallel tunnels. Upon final separation these appear as a pattern of parallel ridges on each fracture face. Striking similarities in morphology have been noted here between Y-flutings in Zircaloy and those produced during tests on unstable fluid interfaces: the direction of motion of the fluid interface can be determined from the Y-morphology and is in agreement with observations from Zircaloy SCC tests. It is further demonstrated that equations governing thermodynamic and kinetic instability of fluid interfaces can be adapted to relate the fluting spacing in Zircaloy to standard fracture mechanics parameters. (author)

  1. Effect of plant spacing on weed suppression and yield of fluted ...

    African Journals Online (AJOL)

    The field study was conducted to evaluate the effect of plant spacing on weed suppression yield and economic benefit of fluted pumpkin (Telfeiria occidentalis Hook F). The experiment was carried out at the Department of Crop and Soil Science Demonstration Plot, Faculty of Agriculture, University of Port Harcourt, Nigeria ...

  2. Tube with helical grooves for heat transfer and its fabrication process

    International Nuclear Information System (INIS)

    Yampolsky, J.S.

    1977-01-01

    The invention suggests a thermal transfer tube for use in a heat exchanger. The wall of the tube includes a certain number of spiral or helical, internal and external, grooves for the flow of the heat exchange fluids along the tube. The grooves extend for the full length of the tube. They are uniform in design and mark the internal and external spiral hollows and crests. A process for the manufacture of the heat transfer tube is also included in the invention [fr

  3. Tracking Target and Spiral Waves

    DEFF Research Database (Denmark)

    Jensen, Flemming G.; Sporring, Jon; Nielsen, Mads

    2002-01-01

    A new algorithm for analyzing the evolution of patterns of spiral and target waves in large aspect ratio chemical systems is introduced. The algorithm does not depend on finding the spiral tip but locates the center of the pattern by a new concept, called the spiral focus, which is defined by the...

  4. Are spiral galaxies heavy smokers?

    International Nuclear Information System (INIS)

    Davies, J.; Disney, M.; Phillipps, S

    1990-01-01

    The dustiness of spiral galaxies is discussed. Starburst galaxies and the shortage of truly bright spiral galaxies is cited as evidence that spiral galaxies are far dustier than has been thought. The possibility is considered that the dust may be hiding missing mass

  5. Spiraling into Transformative Learning

    Science.gov (United States)

    Cranton, Patricia

    2010-01-01

    This article explores how technical and vocational learning may spiral into transformative learning. Transformative learning theory is reviewed and the learning tasks of critical theory are used to integrate various approaches to transformative learning. With this as a foundation, the article explores how transformative learning can be fostered in…

  6. Archimedean Voronoi spiral tilings

    Science.gov (United States)

    Yamagishi, Yoshikazu; Sushida, Takamichi

    2018-01-01

    We study the transition of the number of spirals (called parastichy in the theory of phyllotaxis) within a Voronoi tiling for Archimedean spiral lattices. The transition of local parastichy numbers within a tiling is regarded as a transition at the base site point in a continuous family of tilings. This gives a natural description of the quasiperiodic structure of the grain boundaries. It is proved that the number of tiles in the grain boundaries are denominators of rational approximations of the argument (called the divergence angle) of the generator. The local parastichy numbers are non-decreasing functions of the plastochron parameter. The bifurcation diagram of local parastichy numbers has a Farey tree structure. We also prove Richards’ formula of spiral phyllotaxis in the case of Archimedean Voronoi spiral tilings, and show that, if the divergence angle is a quadratic irrational number, then the shapes of tiles in the grain boundaries are close to rectangles. If the divergence angle is linearly equivalent to the golden section, then the shape of tiles in the grain boundaries is close to square.

  7. Theory of spiral structure

    International Nuclear Information System (INIS)

    Lin, C.C.

    1977-01-01

    The density wave theory of galactic spirals has now developed into a form suitable for consideration by experts in Applied Mechanics. On the one hand, comparison of theoretical deductions with observational data has convinced astrophysicists of the validity of the basic physical picture and the calculated results. On the other hand, the dynamical problems of a stellar system, such as those concerning the origin of spiral structure in galaxies, have not been completely solved. This paper reviews the current status of such developments, including a brief summary of comparison with observations. A particularly important mechanism, currently called the mechanism of energy exchange, is described in some detail. The mathematical problems and the physical processes involved are similar to those occurring in certain instability mechanisms in the 'magnetic bottle' designed for plasma containment. Speculations are given on the future developments of the theory and on observational programs. (Auth.)

  8. Spiral 2 workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The accelerator and experimental facilities at GANIL will be transformed over the next 5-10 years. The centerpiece of the additions to the accelerator complex will be Spiral-2. This is the first phase of a new radioactive beam facility based on the ISOL principle. The main aim of Spiral-2 will be to produce intense, high quality beams of neutron-rich nuclei created in neutron-induced fission of heavy elements and accelerated by the existing CIME cyclotron. The principal aims of this workshop will be a) to publicize the new facilities, b) to discuss and define the science which might be carried out with them, c) to discuss the instrumentation and infrastructure required to exploit the new facilities and d) to help form collaborations of scientists wishing to design and construct the equipment needed to undertake the science programme. This document gathers most of the slides presented in the workshop.

  9. Spirality: A Noval Way to Measure Spiral Arm Pitch Angle

    Science.gov (United States)

    Shields, Douglas W.; Boe, Benjamin; Henderson, Casey L.; Hartley, Matthew; Davis, Benjamin L.; Pour Imani, Hamed; Kennefick, Daniel; Kennefick, Julia D.

    2015-01-01

    We present the MATLAB code Spirality, a novel method for measuring spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. For a given pitch angle template, the mean pixel value is found along each of typically 1000 spiral axes. The fitting function, which shows a local maximum at the best-fit pitch angle, is the variance of these means. Error bars are found by varying the inner radius of the measurement annulus and finding the standard deviation of the best-fit pitches. Computation time is typically on the order of 2 minutes per galaxy, assuming at least 8 GB of working memory. We tested the code using 128 synthetic spiral images of known pitch. These spirals varied in the number of spiral arms, pitch angle, degree of logarithmicity, radius, SNR, inclination angle, bar length, and bulge radius. A correct result is defined as a result that matches the true pitch within the error bars, with error bars no greater than ±7°. For the non-logarithmic spiral sample, the correct answer is similarly defined, with the mean pitch as function of radius in place of the true pitch. For all synthetic spirals, correct results were obtained so long as SNR > 0.25, the bar length was no more than 60% of the spiral's diameter (when the bar was included in the measurement), the input center of the spiral was no more than 6% of the spiral radius away from the true center, and the inclination angle was no more than 30°. The synthetic spirals were not deprojected prior to measurement. The code produced the correct result for all barred spirals when the measurement annulus was placed outside the bar. Additionally, we compared the code's results against 2DFFT results for 203 visually selected spiral galaxies in GOODS North and South. Among the entire sample, Spirality's error bars overlapped 2DFFT's error bars 64% of the time. For those galaxies in which Source code is available by email request from the primary author.

  10. Flute-like musical instruments: A toy model investigated through numerical continuation

    Science.gov (United States)

    Terrien, Soizic; Vergez, Christophe; Fabre, Benoît

    2013-07-01

    Self-sustained musical instruments (bowed string, woodwind and brass instruments) can be modelled by nonlinear lumped dynamical systems. Among these instruments, flutes and flue organ pipes present the particularity to be modelled as a delay dynamical system. In this paper, such a system, a toy model of flute-like instruments, is studied using numerical continuation. Equilibrium and periodic solutions are explored with respect to the blowing pressure, with focus on amplitude and frequency evolutions along the different solution branches, as well as "jumps" between periodic solution branches. The influence of a second model parameter (namely the inharmonicity) on the behaviour of the system is addressed. It is shown that harmonicity plays a key role in the presence of hysteresis or quasiperiodic regime. Throughout the paper, experimental results on a real instrument are presented to illustrate various phenomena, and allow some qualitative comparisons with numerical results.

  11. Nonlinear stability of m=1 flute mode in a nonparaxial open plasma device

    International Nuclear Information System (INIS)

    Lanskij, I.M.; Stupakov, G.V.

    1991-01-01

    Plasma flute stability as to high shifts under strong effects of ion Larmor finite radius conditions is studied. System consisting of long axisymmetric paraxial mirror device with stabilizing cells at its edges is considered. Variation of plasma energy as to its shift as a whole is calculated. It is shown, that depending on stabilizer type the force bringing plasma back in equilibrium state with shift growth may both increase and decrease

  12. The Dance of the Dead Rhino: William Kentridge’s Magic Flute

    OpenAIRE

    Guarracino, Serena

    2010-01-01

    The article offers a reading of the staging of The Magic Flute by visual artist William Kentridge, focusing on his introduction of the rhino in the visual landscape of the opera as symbol for the silenced subject of violence. Operatic tradition has always been concerned with the staging of death, in particular with the death of its female protagonists, and recent scholarship has highlighted the complicity of the genre with the ideology of Western patriarchy and colonial violence. In this ligh...

  13. Mental training, relaxation techniques and pedagogical instructions to reduce Music Performance Anxiety (MPA) in flute students

    OpenAIRE

    Carmen Viejo Llaneza; Ana Laucirica Larrinaga

    2016-01-01

    Music Performance Anxiety (MPA) is, frequently, one of the problems faced by a musical performer in his or her career. This study observes way in which stage fright affects in musicians, which is a possible factor that may later lead to anxiety in public performances and, furthermore, how we can intervene to mitigate or reduce its effects. An initial interview was conducted with four upper division students of transverse flute. This was followed by some training techniques - relaxation techni...

  14. The Possible Mechanism and Factors Affecting Synthetic Reactive Dye Removal by Treated Flute Reed

    OpenAIRE

    Chatchawan Singhakant

    2010-01-01

    This study investigated the ability of treated flute-reed to adsorb synthetic reactive dye solution in a batch system. The effects of particle size, contact time and adsorption isotherms at various particle sizes and temperatures were investigated. Desorption was studied to confirm the mechanism of adsorption. The results showed that the adsorption capacity increased as the particle size decreased. The smaller particle size required less contact time to reach equilibrium because it had a high...

  15. Band-notched spiral antenna

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jae; Chang, John

    2018-03-13

    A band-notched spiral antenna having one or more spiral arms extending from a radially inner end to a radially outer end for transmitting or receiving electromagnetic radiation over a frequency range, and one or more resonance structures positioned adjacent one or more segments of the spiral arm associated with a notch frequency band or bands of the frequency range so as to resonate and suppress the transmission or reception of electromagnetic radiation over said notch frequency band or bands.

  16. Music Performance Anxiety: Causes, Symptoms and Coping Strategies for Flute Students

    Directory of Open Access Journals (Sweden)

    Andre Sinico

    2013-05-01

    Full Text Available This article addresses the causes, symptoms and coping strategies used by undergraduate flute students from three universalities in Brazil to cope with music performance anxiety (MPA during jury recitals. The data collection and analysis procedures used were similar to a study by Siw Nielsen (1999, i.e., recital participant behavioral observation and verbal reports using semi-structured interviews. Both procedures were recorded in audio and video. As a result, the study highlights sixteen causes, nineteen symptoms, and eighteen strategies used by flute students to cope with MPA. Anxiety among the participants was constantly present to a greater or lesser degree. Its main cause was the repertoire for solo flute; nervousness was the symptom most reported by the participants; and positive self-talk was the most used coping strategy. The research concluded that, since anxiety is an inherent emotion in performing music, musicians must use a broad range of strategies—before and during the performance—to thoroughly deal with the causes and symptoms of anxiety. The article also highlights the importance of music professors in knowing the causes of MPA and its symptoms so that they can plan a strategy consistent with the needs of their students that will help them cope with the negative effects of anxiety.

  17. Three phase spiral liver Scanning

    International Nuclear Information System (INIS)

    Kanyanja, T.A.

    2006-01-01

    The ability to perform rapid back-to-back spiral acquisitions is an important recent technical advantage of spiral CT. this allows imaging of the upper abdomen (liver) during peak arterial enhancement (arterial phase) and during peak hepatic parenchymal enhancement (portal venous phase). Breatheld spiral CT has completely replaced dynamic incremental CT for evaluation of the liver. in selected patients with hyper vascular metastasis (hepatoma, neuroendocrine tumors, renal cell carcinoma, etc.) a biphasic examination is performed with one spiral acquisition obtained during the hepatic arterial phase and a second acquisition during the portal venous phase

  18. Finned Tube With Vortex Generators For A Heat Exchanger.

    Science.gov (United States)

    Sohal, Monohar S.; O'Brien, James E.

    2004-09-14

    A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at least one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

  19. The subtropical nutrient spiral

    Science.gov (United States)

    Jenkins, William J.; Doney, Scott C.

    2003-12-01

    We present an extended series of observations and more comprehensive analysis of a tracer-based measure of new production in the Sargasso Sea near Bermuda using the 3He flux gauge technique. The estimated annually averaged nitrate flux of 0.84 ± 0.26 mol m-2 yr-1 constitutes only that nitrate physically transported to the euphotic zone, not nitrogen from biological sources (e.g., nitrogen fixation or zooplankton migration). We show that the flux estimate is quantitatively consistent with other observations, including decade timescale evolution of the 3H + 3He inventory in the main thermocline and export production estimates. However, we argue that the flux cannot be supplied in the long term by local diapycnal or isopycnal processes. These considerations lead us to propose a three-dimensional pathway whereby nutrients remineralized within the main thermocline are returned to the seasonally accessible layers within the subtropical gyre. We describe this mechanism, which we call "the nutrient spiral," as a sequence of steps where (1) nutrient-rich thermocline waters are entrained into the Gulf Stream, (2) enhanced diapycnal mixing moves nutrients upward onto lighter densities, (3) detrainment and enhanced isopycnal mixing injects these waters into the seasonally accessible layer of the gyre recirculation region, and (4) the nutrients become available to biota via eddy heaving and wintertime convection. The spiral is closed when nutrients are utilized, exported, and then remineralized within the thermocline. We present evidence regarding the characteristics of the spiral and discuss some implications of its operation within the biogeochemical cycle of the subtropical ocean.

  20. The perfect shape spiral stories

    CERN Document Server

    Hammer, Øyvind

    2016-01-01

    This book uses the spiral shape as a key to a multitude of strange and seemingly disparate stories about art, nature, science, mathematics, and the human endeavour. In a way, the book is itself organized as a spiral, with almost disconnected chapters circling around and closing in on the common theme. A particular strength of the book is its extremely cross-disciplinary nature - everything is fun, and everything is connected! At the same time, the author puts great emphasis on mathematical and scientific correctness, in contrast, perhaps, with some earlier books on spirals. Subjects include the mathematical properties of spirals, sea shells, sun flowers, Greek architecture, air ships, the history of mathematics, spiral galaxies, the anatomy of the human hand, the art of prehistoric Europe, Alfred Hitchcock, and spider webs, to name a few.

  1. Origins and spread of fluted-point technology in the Canadian Ice-Free Corridor and eastern Beringia.

    Science.gov (United States)

    Smith, Heather L; Goebel, Ted

    2018-04-02

    Fluted projectile points have long been recognized as the archaeological signature of early humans dispersing throughout the Western Hemisphere; however, we still lack a clear understanding of their appearance in the interior "Ice-Free Corridor" of western Canada and eastern Beringia. To solve this problem, we conducted a geometric morphometric shape analysis and a phylogenetic analysis of technological traits on fluted points from the archaeological records of northern Alaska and Yukon, in combination with artifacts from further south in Canada, the Great Plains, and eastern United States to investigate the plausibility of historical relatedness and evolutionary patterns in the spread of fluted-point technology in the latest Pleistocene and earliest Holocene. Results link morphologies and technologies of Clovis, certain western Canadian, and northern fluted points, suggesting that fluting technology arrived in the Arctic from a proximate source in the interior Ice-Free Corridor and ultimately from the earliest populations in temperate North America, complementing new genomic models explaining the peopling of the Americas.

  2. Hurricane Spiral Bands.

    Science.gov (United States)

    Guinn, Thomas A.; Schubert, Wayne H.

    1993-10-01

    The spiral bands that occur in tropical cyclones can be conveniently divided into two classes-outer bands and inner bands. Evidence is presented here that the outer bands form as the result of nonlinear effects during the breakdown of the intertropical convergence zone (ITCZ) through barotropic instability. In this process a zonal strip of high potential vorticity (the ITCZ shear zone or monsoon trough) begins to distort in a varicose fashion, with the potential vorticity (PV) becoming pooled in local regions that are connected by filaments of high PV. As the pooled regions become more axisymmetric, the filaments become thinner and begin to wrap around the PV centers.It is argued that inner bands form in a different manner. As a tropical cyclone intensifies due to latent heat release, the PV field becomes nearly circular with the highest values of PV in the cyclone center. The radial gradient of PV provides a state on which PV waves (the generalization of Rossby waves) can propagate. The nonlinear breaking of PV waves then leads to an irreversible distortion of the PV contours and a downgradient flux of PV. The continuation of this proem tends to erode the high PV core of the tropical cyclone, to produce a surrounding surf zone, and hence to spread the PV horizontally. In a similar fashion, inner bands can also form by the merger of a vortex with a patch of relatively high PV air. As the merger proem occurs the patch of PV is quickly elongated and wrapped around the vortex. The resulting vortex is generally larger in horizontal extent and exhibits a spiral band of PV.When the formation of outer and inner bands is interpreted in the context of a normal-mode spectral model, they emerge as slow manifold phenomena; that is, they have both rotational and (balanced or slaved) gravitational mode aspects. In this sense, regarding them as simply gravity waves leads to an incomplete dynamical picture.

  3. Flute Teachers’ One-to-One Instructional Strategies at Individual Teaching Stages in Music School

    Directory of Open Access Journals (Sweden)

    Ana Kavčič Pucihar

    2017-12-01

    Full Text Available This article focuses on one-to-one studio based instrumental instruction in music schools. Some novelties in the music school woodwind curricula are presented within various contexts. Teacher – student relationship, their interactions, and knowledge transfer are essential in individual instrumental instruction. The learning process is systematically structured within six teaching stages, ranging from new content presentation to learning reviews. We examined music school flute teachers’ beliefs (N=78 about teaching stages in individual studio based instruction. We researched their new content teaching strategies, guided practice and reinforcement, feedback, homework monitoring strategies, formative review and assessment within music studio academic year.

  4. Simultaneous and integrated neutron-based techniques for material analysis of a metallic ancient flute

    Science.gov (United States)

    Festa, G.; Pietropaolo, A.; Grazzi, F.; Sutton, L. F.; Scherillo, A.; Bognetti, L.; Bini, A.; Barzagli, E.; Schooneveld, E.; Andreani, C.

    2013-09-01

    A metallic 19th century flute was studied by means of integrated and simultaneous neutron-based techniques: neutron diffraction, neutron radiative capture analysis and neutron radiography. This experiment follows benchmark measurements devoted to assessing the effectiveness of a multitask beamline concept for neutron-based investigation on materials. The aim of this study is to show the potential application of the approach using multiple and integrated neutron-based techniques for musical instruments. Such samples, in the broad scenario of cultural heritage, represent an exciting research field. They may represent an interesting link between different disciplines such as nuclear physics, metallurgy and acoustics.

  5. Simultaneous and integrated neutron-based techniques for material analysis of a metallic ancient flute

    International Nuclear Information System (INIS)

    Festa, G; Andreani, C; Pietropaolo, A; Grazzi, F; Scherillo, A; Barzagli, E; Sutton, L F; Bognetti, L; Bini, A; Schooneveld, E

    2013-01-01

    A metallic 19th century flute was studied by means of integrated and simultaneous neutron-based techniques: neutron diffraction, neutron radiative capture analysis and neutron radiography. This experiment follows benchmark measurements devoted to assessing the effectiveness of a multitask beamline concept for neutron-based investigation on materials. The aim of this study is to show the potential application of the approach using multiple and integrated neutron-based techniques for musical instruments. Such samples, in the broad scenario of cultural heritage, represent an exciting research field. They may represent an interesting link between different disciplines such as nuclear physics, metallurgy and acoustics. (paper)

  6. Measuring with the spiral reader

    CERN Multimedia

    1974-01-01

    The spiral reader shown here was at the time, together with the Shivamatic scanning system, the basic equipment used for measuring bubble chamber pictures. Anne Anton sits at the table. (See Photo Archive 7408343.)

  7. Spiral-shaped disinfection reactors

    KAUST Repository

    Ghaffour, Noreddine

    2015-08-20

    This disclosure includes disinfection reactors and processes for the disinfection of water. Some disinfection reactors include a body that defines an inlet, an outlet, and a spiral flow path between the inlet and the outlet, in which the body is configured to receive water and a disinfectant at the inlet such that the water is exposed to the disinfectant as the water flows through the spiral flow path. Also disclosed are processes for disinfecting water in such disinfection reactors.

  8. Spiral inlets for steam turbines

    Science.gov (United States)

    Škach, Radek; Uher, Jan

    2017-09-01

    This paper deals with the design process of special nozzle blades for spiral inlets. Spiral inlets are used for the first stages of high pressure and intermediate pressure steam turbines with both reaction and impulse blades when throttling or sliding pressure control is applied. They improve the steam flow uniformity from the inlet pipe and thus decrease the aerodynamic losses. The proposed evaluation of the inlet angle is based on the free vortex law.

  9. Individuality of movements in music--finger and body movements during playing of the flute.

    Science.gov (United States)

    Albrecht, Stefan; Janssen, Daniel; Quarz, Esther; Newell, Karl M; Schöllhorn, Wolfgang I

    2014-06-01

    The achievement of mastery in playing a composition by means of a musical instrument typically requires numerous repetitions and corrections according to the keys and notations of the music piece. Nevertheless, differences in the interpretation of the same music piece by highly skilled musicians seem to be recognizable. The present study investigated differences within and between skilled flute players in their finger and body movements playing the same piece several times on the same and on different days. Six semiprofessional and four professional musicians played an excerpt of Mozart's Flute Concerto No. 2 several times on three different days. Finger and body movements were recorded by 3D motion capture and analyzed by linear and nonlinear classification approaches. The findings showed that the discrete and continuous movement timing data correctly identified individuals up to 100% by means of their finger movements and up to 94% by means of their body movements. These robust examples of identifying individual movement patterns contradict the prevailing models of small, economic finger movements that are favored in the didactic literature for woodwind players and question traditional recommendations for teaching the learning of motor skills. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Floral Biology of Fluted Pumpkin (Telfairia occidentalis Hook. F.

    Directory of Open Access Journals (Sweden)

    Lawrence Stephen FAYEUN

    2016-12-01

    Full Text Available Knowledge of floral biology is essential to crop improvement. Ten genotypes of fluted pumpkin (Telfairia occidentalis were observed for floral morphology, phenology and insect visitation for two consecutive years. Functional dioecy of fluted pumpkin was confirmed, whereas none of the studied genotypes was monoecious. Floral structures differed significantly among the genotypes. Both male and female flowers were symmetrical, pentasepalous, fimbriate and non-bright pentapetalous, but male flowers were more numerous. Male inflorescences emerged from 11 to 14 weeks after planting and the female flower buds appeared about 4 weeks later. The flowering period of the male flowers was longer than that of female flowers and both gender flowering periods coincided for a specific interval. It took between 11 to 14 days from bud initiation to anthesis and flowering ceased when there were occurrences of successful fruits set. In both gender flowers petals started unfurling at around 6.00 pm and full bloom was achieved by dawn, while petal shrivelled at sun set (between 6.30 pm to 7.30 pm. The anthers dehisced at anthesis of the male flowers; the pollen grains were whitish and sticky. Only the male flowers have nectar and pollen and this may explain infrequent female flowers visitation. Hover flies (Cheilosia species were the major floral visitors observed.

  11. The Dance of the Dead Rhino: William Kentridge’s Magic Flute

    Directory of Open Access Journals (Sweden)

    Serena Guarracino

    2010-11-01

    Full Text Available The article offers a reading of the staging of The Magic Flute by visual artist William Kentridge, focusing on his introduction of the rhino in the visual landscape of the opera as symbol for the silenced subject of violence. Operatic tradition has always been concerned with the staging of death, in particular with the death of its female protagonists, and recent scholarship has highlighted the complicity of the genre with the ideology of Western patriarchy and colonial violence. In this light, Kentridge's appropriation stages Mozart's opera as both voice of colonial Europe and place of resistance for the postcolonial artist. Kentridge moves the setting of the opera to colonial Africa, and the Flute becomes haunted with the massacre of the Herero people in South West Africa by the German army led by general von Trotha (1904-1907. The African white rhino, a species under the threat of extinction, works in this work as proxy for the missing corpses of the Herero people; in its being subject to humiliation and ruthless murder, it recalls Judith Butler's recent attempt at a different categorization of human life as both a continuous exposure to violence and what can be mourned after death. With its silence among the powerful sounds of Mozart's opera, the body of the dead, dancing rhino stands at the centre of Kentridge's work, which becomes a ceremony of mourning where the Western canon can be made to "resonate differently" (Trinh T. Minh-ha.

  12. Feeding Tubes

    Science.gov (United States)

    ... the TPN. Tubes Used for Enteral Feeds NG (Nasogastric Tube) A flexible tube is placed via the nose, ... portion of the small intestine Naso – nose NG – Nasogastric Tube -ostomy – new opening Percutaneous – through the skin PEJ – ...

  13. Spiral Inflector For Compact Cyclotron

    CERN Document Server

    Karamysheva, G A

    2004-01-01

    Compact cyclotron for explosives detection by nuclear resonance absorption of γ-rays in nitrogen is under development [1] Cyclotron will be equipped with the external ion source. The injection system consists of a double-drift beam bunching system, a spiral inflector, beam diagnostics, focusing and adjustment elements [2]. The spiral inflector for ion bending from axial to median plane is used. Computer model of spiral inflector for the Customs cyclotron is developed. 3D electrostatic field calculations of the designed inflector are performed. Calculated electric field map and magnetic field map of the cyclotron [3] are used for beam dynamic simulations. Numeric simulations are carried out for 500 particles using code for calculation of particle dynamics by integration of differential equations in Cartesian coordinate system written in MATLAB. Direct Coulomb particle-to-particle method is used to take into account space-charge effects.

  14. Complete genome sequence of a new bipartite begomovirus infecting fluted pumpkin (Telfairia occidentalis) plants in Cameroon.

    Science.gov (United States)

    Leke, Walter N; Khatabi, Behnam; Fondong, Vincent N; Brown, Judith K

    2016-08-01

    The complete genome sequence was determined and characterized for a previously unreported bipartite begomovirus from fluted pumpkin (Telfairia occidentalis, family Cucurbitaceae) plants displaying mosaic symptoms in Cameroon. The DNA-A and DNA-B components were ~2.7 kb and ~2.6 kb in size, and the arrangement of viral coding regions on the genomic components was like those characteristic of other known bipartite begomoviruses originating in the Old World. While the DNA-A component was more closely related to that of chayote yellow mosaic virus (ChaYMV), at 78 %, the DNA-B component was more closely related to that of soybean chlorotic blotch virus (SbCBV), at 64 %. This newly discovered bipartite Old World virus is herein named telfairia mosaic virus (TelMV).

  15. Tapered modular fluted titanium stems for femoral fixation in revision total knee arthroplasty.

    Science.gov (United States)

    Stambough, Jeffrey B; Mason, J Bohannon; Riesgo, Aldo M; Fehring, Thomas K

    2018-03-01

    Consensus regarding femoral stem fixation options in revision total knee arthroplasty remains controversial. Tapered, modular, fluted titanium (TMFT) stems have an excellent track record in total hip arthroplasty for their ability to provide axial and rotational stability in situations of compromised host bone. We present 3 successfully treated cases in which the Food & Drug Administration granted permission to use custom TMFT stems in situations of failed femoral fixation in multiple revised knees. These stems hold promise to achieve stable fixation in revision total knee arthroplasty where host metadiaphyseal bone is deficient. Implant manufactures should consider dedicating future resources to create adapters that can link existing successful TMFT stems currently used in hip arthroplasty to revision total knee components when host bone is severely compromised.

  16. Active feedback stabilization of the flute instability in a mirror machine using field-aligned coils

    International Nuclear Information System (INIS)

    Lifshitz, A.; Be'ery, I.; Fisher, A.; Ron, A.; Fruchtman, A.

    2012-01-01

    A plasma confined in linear mirror machines is unstable even at low β, mainly because of the flute instability. One possible way to stabilize the plasma is to use active feedback to correct the plasma shape in real time. The theoretically investigated apparatus consists of feedback coils aligned with the magnetic field, immersed in a cold plasma around the hot core. When the current through the feedback coils changes, the plasma moves to conserve the magnetic flux via compressional Alfvén waves. An analytical model is used to find a robust feedback algorithm with zero residual currents. It is shown that due to the plasma's rotation, maximal stability is obtained with a large phase angle between the perturbations' modes and the feedback integral-like term. Finally, a two-dimensional MHD simulation implementing the above algorithm in fact shows stabilization of the plasma with zero residual currents. (paper)

  17. GANIL-SPIRAL1-SPIRAL2: Highlights and Perspectives

    Science.gov (United States)

    Gales, S.

    2010-06-01

    GANIL presently offers unique opportunities in nuclear physics and many other fields that arise from not only the provision of low-energy stable beams, fragmentation beams and re-accelerated radioactive species, but also from the availability of a wide range of state-of-the-art spectrometers and instrumentation. A few examples of recent highlights are presented. With the construction of SPIRAL2 over the next few years, GANIL is in a good position to retain its world-leading capability. As selected by the ESFRI committee, the next generation of ISOL facility in Europe is represented by the SPIRAL2 project to be built at GANIL (Caen, France). SPIRAL 2 is based on a high power, CW, superconducting LINAC, delivering 5 mA of deuteron beams at 40 MeV (200 KW) directed on a C converter+ Uranium target and producing therefore more 1013 fissions/s. The expected radioactive beams intensities in the mass range from A = 60 to A = 140, will surpass by two order of magnitude any existing facilities in the world. These unstable atoms will be available at energies between few KeV/n to 15 MeV/n. The same driver will accelerate high intensity (100*A to 1 mA), heavier ions (Ar up to Xe) at maximum energy of 14 MeV/n. Under the 7FP program of European Union called*Preparatory phase*, the SPIRAL2 project has been granted a budget of about 4 M€ to build up an international consortium around this new venture. The status of the construction of SPIRAL2 accelerator and associated physics instruments in collaboration with EU and International partners will be presented.

  18. Reproducibility of multi-slice spiral computed tomography scans: An experimental study

    NARCIS (Netherlands)

    van Straten, Marcel; Venema, Henk W.; Hartman, Joris; den Heeten, Gerard J.; Grimbergen, Cornelis A.

    2004-01-01

    In multi-slice spiral computed tomography (CT) images interpolation artifacts are present. The relationship between the x-ray tube rotation angle and these artifacts is demonstrated. A head phantom was repeatedly scanned with a four-slice CT scanner at different pitch values. Two scans, made with

  19. Quasicrystallography on the spiral of Archimedes

    International Nuclear Information System (INIS)

    Bursill, L.A.

    1990-01-01

    The concept of a spiral lattice is discussed. Some examples of known mineral structures, namely clino asbestos, halloysite and cylindrite, are then interpreted in terms of this structural principle. An example of a synthetic sulphide catalyst spiral structure having atomic dimensions is also described. All of these inorganic spiral structures are based on the sprial of Archimedes. The principles for a new type of crystallography, based on the Archimedian spiral, are then presented. 45 refs., 8 figs

  20. Inspired Spirals. Teaching Art with Art.

    Science.gov (United States)

    Hubbard, Guy

    2001-01-01

    Discusses spirals in nature, man-made objects, and art. Focuses on art that incorporates the spiral, including works by M. C. Escher and Frank Lloyd Wright, an African headdress, and a burial urn. Describes activities to help students make spirals of their own, such as constructing a coil clay pot. (CMK)

  1. The Spiral Pattern During Development*

    African Journals Online (AJOL)

    1971-08-07

    Aug 7, 1971 ... which are destined to become the limb areas bud out laterally. Fig. 8. The early cells, which are destined to develop into the upper and the lower limbs, after lateral budding has occurred. Fig. 11 demonstrates the human embryo of about 5 mm. CR length and age of about 32 days. The spiral pattern is.

  2. A study of spiral galaxies

    International Nuclear Information System (INIS)

    Wevers, B.M.H.R.

    1984-01-01

    Attempts have been made to look for possible correlations between integral properties of spiral galaxies as a function of morphological type. To investigate this problem, one needs the detailed distribution of both the gaseous and the stellar components for a well-defined sample of spiral galaxies. A sample of about 20 spiral galaxies was therefore defined; these galaxies were observed in the 21 cm neutral hydrogen line with the Westerbork Synthesis Radio Telescope and in three broad-band optical colours with the 48-inch Palomar Smidt Telescope. First, an atlas of the combined radio and optical observations of 16 nearby northern-hemisphere spiral galaxies is presented. Luminosity profiles are discussed and the scale lengths of the exponential disks and extrapolated central surface brightnesses are derived, as well as radial color distributions; azimuthal surface brightness distributions and rotation curves. Possible correlations with optical features are investigated. It is found that 20 to 50 per cent of the total mass is in the disk. (Auth.)

  3. Strength analysis of helical buckling tubing using spring theory

    Science.gov (United States)

    Cao, Yinping; Xia, Hui; Dou, Yihua

    2017-08-01

    With the constraint of the wellbore, tubing has possibility to conduct spiral plastic deformation if axial compression load is great enough. The residual stress from the plastic deformation of tubing will eventually influence the effective stress, thus strength safety. The effective stress and strength safety of spiral plastic deformed tubing are different from undeformed or straight tubing. The purpose of this research is to investigate the effective stress and strength safety of helical buckling tubing. The analytic models of tubing in vertical well and inclined well were established. Using spring theory and equilibrium equations, the equations of shear force and bending moment of tubing were derived. Considering the stresses of the tubing are three-dimensional stresses and tubing undergoes plastic deformation, the distortional strain energy design criterion was taken to derive the effective stresses equations of the tubing. MATLAB program was coded to investigate the influence of compression force, tubing length and screw-pitch on the effective stress for the commonly used tubing. It can be used to evaluate the strength safety of in-situ tubing more accurately.

  4. Definition of the Face Profile in the End Section of the Teeth of the Thread Milling Cutters with Helical Flutes

    Directory of Open Access Journals (Sweden)

    O. V. Malkov

    2014-01-01

    Full Text Available An increasing thread accuracy in details of the machine-building production results from the improved design and manufacturing stages of threading tools. In modern industry, thread milling cutters gain an increasingly greater spread for thread manufacturing. Preliminary studies have shown that improving the accuracy of a cut thread is closely connected with the task of profiling the teeth of the thread milling cutters with helical flutes, and the accuracy of the solution depends on the face profile of the tool into the end section. In addition, the face profile of the tool is required to solve problems related to the calculation of strength thread milling cutters and evaluation of geometrical parameters of the teeth.The analysis of GOST 1336-77 on thread milling cutters showed that there are no geometric and structural parameters characterizing the end thread milling cutters with helical flutes. Since the standard presents thread milling cutters with a straight flutes, in which the shape of the tooth profile cutters of the second order is the same as in normal and end sections, for cutters with helical flutes it is necessary to solve the problem of conversion of normal and end sections to get the desired shape of the cutting edge.In order to assess the face profile, the end mills of high speed steel and carbide have been analyzed to show that the vast majority of the face profile of the tooth is specified in the normal section line, which is taken as an input in determining the function of the profile form for the face of the end section of the teeth thread milling cutter with helical flutes.The paper solves the problem of calculating the coordinates of the profile of the endsection of a tooth cutters with helical flutes adopted at the original tooth profile in normal section. It has been verified by modeling software CATIA V5 R17. An example illustrates finding the function form of the end section. Calculations have shown that in the end

  5. The use of a mono-fluted reamer results in decreased enlargement of the tibial tunnel when using a transtibial ACL reconstruction technique.

    Science.gov (United States)

    Knight, Justin R; Condie, Daniel; Querry, Ross; Robertson, William J

    2014-02-01

    To evaluate whether femoral tunnel preparation using a mono-fluted reamer rather than an acorn reamer would result in less tibial tunnel deformation when using a transtibial technique for anterior cruciate ligament reconstruction. Tibial and femoral tunnel preparation was performed in four matched pairs of cadaveric knees. The tibial tunnel was drilled using a standard acorn reamer. The femoral tunnel was prepared using a transtibial technique with a mono-fluted reamer, and then, the same femoral tunnel was re-reamed using an acorn reamer. The anterior-posterior (AP) and medial-lateral (ML) dimensions of the tibial tunnel were recorded after each reamer. We then compared the measurements following the use of each reamer using a paired two-sample t test. There was a significantly larger degree of tibial tunnel deformation following femoral tunnel preparation with the acorn reamer when compared with the mono-fluted reamer. The initial tibial tunnel measured 10.5 and 10.1 mm in the AP and ML dimensions, respectively. The resultant AP diameter of the tibial tunnel after femoral reaming was 16.7 mm (p mono-fluted reamer. The ML diameters were 11.3 mm (p = 0.003) versus 10.2 mm (p = 0.07) for the acorn and mono-fluted reamer, respectively. The use of a mono-fluted reamer for femoral tunnel preparation results in less tibial tunnel deformation during transtibial reaming.

  6. Cannon de Hermeto Pascoal: aspectos musicais e religiosos em uma obra-prima para flauta Cannon by Hermeto Pascoal: musical and religious aspects in a flute masterpiece

    Directory of Open Access Journals (Sweden)

    Fausto Borém

    2010-12-01

    Full Text Available Estudo de caso sobre Cannon de Hermeto Pascoal, obra para flauta, humming na flauta e sons pré-gravados, planejada como uma sessão espírita musical e gravada pelo compositor no disco Slaves Mass (PASCOAL, 1977. A partir do desenho artístico de uma pauta espiralada na capa interna do mesmo LP (PASCOAL e PEREIRA, 1977 e de uma transcrição baseada na faixa gravada, a partitura da obra foi detalhadamente reconstituída e editada (PASCOAL e BORÉM, 2010; incluída neste volume de Per Musi às p.80-82. A combinação das análises formal, escalar e proporcional da partitura e seu cruzamento com a análise espectral da gravação revelam grande unidade e uma íntima relação entre os conteúdos musicais e extra-musicais da obra, na qual elementos opostos dialogam: a improvisação e as camadas de superposição de sons pré-gravados, a sonoridade acústica e os sons manipulados, a performance individual e a coletiva, a estabilidade e a instabilidade modal, as linguagens popular (embolada, jazz modal, free jazz e erudita (música concreta, atonalismo, cadenza, recitativo, os mundos terreno e espiritual. Apresenta também, em primeira mão, a abordagem analítica do "continuum separação-fusão paradoxal" da obra, a partir de ferramenta etnomusicológica criada e realizada por COSTA-LIMA NETO (2009. Inclui uma contextualização do papel da religião na música do "mago" multi-instrumentista, arranjador e compositor da música popular brasileira.Case study on Cannon by Brazilian composer, arranger and multi-instrumentalist Hermeto Pascoal, a work for flute, flute humming and pre-recorded sounds, designed as a musical spiritism session and included in the LP Slaves Mass (PASCOAL, 1977. Departing from an artistic drawing of a music staff spiral included in the internal covers of the same LP (PASCOAL e PEREIRA, 1977 and a transcription based on the listening of the track in the same disc, the score of the work was reconstituted and edited in detail

  7. Soil Chemical Changes and Growth of Fluted Pumpkin (Telfairia occidentalis Hook F) Resulting from Untreated Petroleum Industry Effluent Application

    OpenAIRE

    , ER Orhue; , V Edosa; , V Eleta

    2016-01-01

    This article revealed the results of the impact of untreated petroleum industry effluent on some soil chemical properties and agronomic characters of fluted pumpkin (Telfairia occidentalis).A completely randomized design was used. In this greenhouse trial, the following rates of 0, 100, 200, 300, 400 and 500 ml per 5 kg topsoil were used. The chemical properties determined in the soil treated with the effluent appreciated higher when compared to the control. The Exchangeable Acidity however d...

  8. Effect of top metal contact on the electrical properties of suspended spiral multiwalled carbon nanotube

    Science.gov (United States)

    Dhall, Shivani; Jaggi, Neena

    2014-04-01

    The electrical transport behavior of individual spiral multiwalled carbon nanotube (MWCNT), functionalized via chemical route, has been investigated. The electrical current and conductance of such dangling bond attached tube, has been increased, after deposition of platinum (Pt) metal contacts at the two ends using electron beam induced deposition technique (EBID). The increment in the conductance is explained in terms of the change in the density of the states (DOS) near the Fermi level by dangling bonds and Pt atoms presence on the tube. Scanning electron microscope (SEM) image confirms its spiral nature after functionalization. Current -voltage measurements reveal a significant enhancement in the electrical transport of the same tube after the deposition of side metal contact. These results can be useful for the fabrication of nanoelectronic devices.

  9. Three-dimensional spiral CT for neurosurgical planning

    International Nuclear Information System (INIS)

    Klein, H.M.; Bertalanffy, H.; Mayfrank, L.; Thron, A.; Guenther, R.W.; Gilsbach, J.M.

    1994-01-01

    We carried out 22 examinations to determine the value of three-dimensional (3D) volumetric CT (spiral CT) for planning neurosurgical procedures. All examinations were carried out on a of the first generation spiral CT. A tube model was used to investigate the influence of different parameter settings. Bolus injection of nonionic contrast medium was used when vessels or strongly enhancing tumours were to be delineated. 3D reconstructions were carried out using the integrated 3D software of the scanner. We found a table feed of 3 mm/s with a slice thickness of 2 mm and an increment of 1 mm to be suitable for most purposes. For larger regions of interest a table feed of 5 mm was the maximum which could be used without blurring of the 3D images. Particular advantages of 3D reconstructed spiral scanning were seen in the planning of approaches to the lower clivus, acquired or congenital bony abnormalities and when the relationship between vessels, tumour and bone was important. (orig.)

  10. Low surface brightness spiral galaxies

    International Nuclear Information System (INIS)

    Romanishin, W.

    1980-01-01

    This dissertation presents an observational overview of a sample of low surface brightness (LSB) spiral galaxies. The sample galaxies were chosen to have low surface brightness disks and indications of spiral structure visible on the Palomar Sky Survey. They are of sufficient angular size (diameter > 2.5 arcmin), to allow detailed surface photometry using Mayall 4-m prime focus plates. The major findings of this dissertation are: (1) The average disk central surface brightness of the LSB galaxies is 22.88 magnitude/arcsec 2 in the B passband. (2) From broadband color measurements of the old stellar population, we infer a low average stellar metallicity, on the order of 1/5 solar. (3) The spectra and optical colors of the HII regions in the LSB galaxies indicate a lack of hot ionizing stars compared to HII regions in other late-type galaxies. (4) The average surface mass density, measured within the radius containing half the total mass, is less than half that of a sample of normal late-type spirals. (5) The average LSB galaxy neutral hydrogen mass to blue luminosity ratio is about 0.6, significantly higher than in a sample of normal late-type galaxies. (6) We find no conclusive evidence of an abnormal mass-to-light ratio in the LSB galaxies. (7) Some of the LSB galaxies exhibit well-developed density wave patterns. (8) A very crude calculation shows the lower metallicity of the LSB galaxies compared with normal late-type spirals might be explained simply by the deficiency of massive stars in the LSB galaxies

  11. Multiple mechanisms quench passive spiral galaxies

    Science.gov (United States)

    Fraser-McKelvie, Amelia; Brown, Michael J. I.; Pimbblet, Kevin; Dolley, Tim; Bonne, Nicolas J.

    2018-02-01

    We examine the properties of a sample of 35 nearby passive spiral galaxies in order to determine their dominant quenching mechanism(s). All five low-mass (M⋆ environments. We postulate that cluster-scale gas stripping and heating mechanisms operating only in rich clusters are required to quench low-mass passive spirals, and ram-pressure stripping and strangulation are obvious candidates. For higher mass passive spirals, while trends are present, the story is less clear. The passive spiral bar fraction is high: 74 ± 15 per cent, compared with 36 ± 5 per cent for a mass, redshift and T-type matched comparison sample of star-forming spiral galaxies. The high mass passive spirals occur mostly, but not exclusively, in groups, and can be central or satellite galaxies. The passive spiral group fraction of 74 ± 15 per cent is similar to that of the comparison sample of star-forming galaxies at 61 ± 7 per cent. We find evidence for both quenching via internal structure and environment in our passive spiral sample, though some galaxies have evidence of neither. From this, we conclude no one mechanism is responsible for quenching star formation in passive spiral galaxies - rather, a mixture of mechanisms is required to produce the passive spiral distribution we see today.

  12. A comparison of ROChem reverse osmosis and spiral wound reverse osmosis membrane modules

    Energy Technology Data Exchange (ETDEWEB)

    Siler, J.L.

    1992-01-31

    Testing of the ROChem Disc Tube[reg sign] reverse osmosis (RO) module's performance on biologically active feed waters has been completed. Both the ROChem module (using Filmtec standard-rejection seawater membranes) and the Filmtec spiral-wound membrane module (using Filmtec high-rejection seawater membranes) were tested with stimulant solutions containing typical bacteria and metal hydroxide levels found in the F/H Effluent Treatment Facility (ETF) influent. Results indicate that the ROChem module gave superior performance over the spiral-wound module. Water flux losses were reduced by over 30% for water recoveries above 40%.

  13. A comparison of ROChem reverse osmosis and spiral wound reverse osmosis membrane modules

    Energy Technology Data Exchange (ETDEWEB)

    Siler, J.L.

    1992-01-31

    Testing of the ROChem Disc Tube{reg_sign} reverse osmosis (RO) module`s performance on biologically active feed waters has been completed. Both the ROChem module (using Filmtec standard-rejection seawater membranes) and the Filmtec spiral-wound membrane module (using Filmtec high-rejection seawater membranes) were tested with stimulant solutions containing typical bacteria and metal hydroxide levels found in the F/H Effluent Treatment Facility (ETF) influent. Results indicate that the ROChem module gave superior performance over the spiral-wound module. Water flux losses were reduced by over 30% for water recoveries above 40%.

  14. Multiple antibiotic-resistant bacteria on fluted pumpkin leaves, a herb of therapeutic value.

    Science.gov (United States)

    Igbeneghu, Oluwatoyin A; Abdu, Abdulrasheed B

    2014-06-01

    Fluted pumpkin (Telfairia occidentalis) is a minimally-processed green leafy vegetable traditionally used for its antianaemic properties in the form of leaf juice without a heating or inactivation step before consumption. The aim of the study was to assess the presence of surface microbiota on T. occidentalis leaves and also to determine the antimicrobial susceptibility of isolated organisms. Bacterial contaminants on 50 samples of T. occidentalis leaves were isolated and characterized using standard biochemical methods and the antimicrobial susceptibility of isolated organisms was determined using the antibiotic disc diffusion assay. The results obtained show that the leaves of T. occidentalis is contaminated with organisms which included Enterobacter agglomerans (25.9%), Proteus vulgaris (24.9%), Klebsiella spp. (2.6%), and Serratia liquefaciens (2.1%). Other bacterial isolates recovered in order of frequency included: Staphylococcus spp. (33.7%), Bacillus spp. (8.3%), and Pseudomonas fluorescens (2.6%). Of the 193 bacterial isolates from the leaves of T. occidentalis samples tested for antimicrobial resistance, all (100%) were found to be resistant to ampicillin, cloxacillin, augmentin, erythromycin, and tetracycline while 96% of the isolates were resistant to cephalothin. Resistance to trimethoprim (93%) and gentamicin (83%) was also observed. Approximately, 22% of the isolates were resistant to ciprofloxacin; however, only 11 (5.8%) were resistant to ofloxacin. Thus, uncooked T. occidentalis is a potential source of highly-resistant epiphytic bacteria which could be opportunistic pathogens in consumers.

  15. Experimental investigation of a coherent flute instability using a heavy ion beam probe

    International Nuclear Information System (INIS)

    Glowienka, J.C.; Jennings, W.C.; Hickok, R.L.

    1988-01-01

    A coherent, low-frequency instability found in a cylindrical, hollow cathode arc plasma has been investigated by using a heavy ion beam probe (HIBP). The energy density of the plasma was high enough to render it inaccessible to Langmuir probes, but the HIBP was able to provide measurements throughout the plasma cross section. The data clearly show that azimuthal symmetry does not exist. Radial profiles of steady-state density and space potential and of simultaneous n, phi amplitude and phase were obtained to allow detailed comparison between theory and experiment. Predictions from a cylindrically symmetric, small-perturbation theoretical model provide reasonably conclusive identification of the instability as a Kelvin--Helmholtz flute driven by and localized in a region of fluid shear. The most serious discrepancy was with regard to the oscillation frequency, which was consistently predicted to be three to four times lower than that observed experimentally. The reason for the discrepancy is not understood, but it is probably related to inadequacies in the theory caused by assumptions of azimuthal symmetry and of small linear perturbations

  16. Fabrication and Testing of Durable Redundant and Fluted-Core Joints for Composite Sandwich Structures

    Science.gov (United States)

    Lin, Shih-Yung; Splinter, Scott C.; Tarkenton, Chris; Paddock, David A.; Smeltzer, Stanley S.; Ghose, Sayata; Guzman, Juan C.; Stukus, Donald J.; McCarville, Douglas A.

    2013-01-01

    The development of durable bonded joint technology for assembling composite structures is an essential component of future space technologies. While NASA is working toward providing an entirely new capability for human space exploration beyond low Earth orbit, the objective of this project is to design, fabricate, analyze, and test a NASA patented durable redundant joint (DRJ) and a NASA/Boeing co-designed fluted-core joint (FCJ). The potential applications include a wide range of sandwich structures for NASA's future launch vehicles. Three types of joints were studied -- splice joint (SJ, as baseline), DRJ, and FCJ. Tests included tension, after-impact tension, and compression. Teflon strips were used at the joint area to increase failure strength by shifting stress concentration to a less sensitive area. Test results were compared to those of pristine coupons fabricated utilizing the same methods. Tensile test results indicated that the DRJ design was stiffer, stronger, and more impact resistant than other designs. The drawbacks of the DRJ design were extra mass and complex fabrication processes. The FCJ was lighter than the DRJ but less impact resistant. With barely visible but detectable impact damages, all three joints showed no sign of tensile strength reduction. No compression test was conducted on any impact-damaged sample due to limited scope and resource. Failure modes and damage propagation were also studied to support progressive damage modeling of the SJ and the DRJ.

  17. Field tests of 2- and 40-tube condensers at the East Mesa Geothermal Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, R.W.; Domingo, N.

    1982-05-01

    Two water-cooled isobutane condensers, one with 2 tubes and one with 40 tubes, were subjected to field tests at the East Mesa Geothermal Test Site to assess relative heat transfer performance in both surface evaporator and direct-contact evaporator modes. The five groups of tests established that field performance was below earlier laboratory-determined levels and that direct-contact evaporator mode performance was poorer than that for the surface evaporator mode. In all test situations, fluted condenser tubes performed better than smooth condenser tubes. Cooling water quality had no significant effect on performance, but brine preflash in the direct-contact mode did promote some relative performance improvement. Important implications of these results for binary geothermal power plants are that (1) working-fluid-side impurities can significantly degrade heat transfer performance of the power plant condensers and (2) provisions for minimizing such impurities may be required.

  18. Spiral 2 the scientific objectives

    International Nuclear Information System (INIS)

    2006-06-01

    The French ministry of research took the decision to build Spiral-2 in May 2005. Its construction costs are estimated to 130 million euros while its operating costs will near 8.5 million euros per year. The construction works will last 5 years. The Spiral-2 facility is based on a high power, superconducting driver Linac, which will deliver a high intensity, 40 MeV deuteron beam as well as a variety of heavy-ion beams with mass over charge ratio equal to 3 and energy up to 14.5 MeV/nucleon. Using a carbon converter, fast neutrons from the breakup of the 5 mA of deuterons impinging on a uranium carbide target will induce a rate of up to 10 14 fissions/s. The radioactive ion beam intensities in the mass range from A = 60 to 140 will be of the order of 10 6 to 10 11 particles/s surpassing by one or two orders-of-magnitude any existing facility in the world. A direct irradiation of the UC 2 target with 3,4 He, 6,7 Li or 12 C may also be used. Different production targets will be used to produce high-intensity beams of light radioactive species with the Isol technique. The extracted radioactive ion beam will be accelerated to energies up to 20 MeV/nucleons by the existing Cime cyclotron. One of the most important features of the future Ganil accelerator complex will be the capability of delivering up to 5 stable or radioactive beams simultaneously in the energy range from the keV to several tens of MeV/nucleons. The document details also the future contribution of Spiral-2 concerning the structure of exotic nuclei, the thermodynamical aspects of nuclear matter, nucleosynthesis, the fundamental basic interactions, and the use of neutrons. (A.C.)

  19. Spiral 2 the scientific objectives

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-06-15

    The French ministry of research took the decision to build Spiral-2 in May 2005. Its construction costs are estimated to 130 million euros while its operating costs will near 8.5 million euros per year. The construction works will last 5 years. The Spiral-2 facility is based on a high power, superconducting driver Linac, which will deliver a high intensity, 40 MeV deuteron beam as well as a variety of heavy-ion beams with mass over charge ratio equal to 3 and energy up to 14.5 MeV/nucleon. Using a carbon converter, fast neutrons from the breakup of the 5 mA of deuterons impinging on a uranium carbide target will induce a rate of up to 10{sup 14} fissions/s. The radioactive ion beam intensities in the mass range from A = 60 to 140 will be of the order of 10{sup 6} to 10{sup 11} particles/s surpassing by one or two orders-of-magnitude any existing facility in the world. A direct irradiation of the UC{sub 2} target with {sup 3,4}He, {sup 6,7}Li or {sup 12}C may also be used. Different production targets will be used to produce high-intensity beams of light radioactive species with the Isol technique. The extracted radioactive ion beam will be accelerated to energies up to 20 MeV/nucleons by the existing Cime cyclotron. One of the most important features of the future Ganil accelerator complex will be the capability of delivering up to 5 stable or radioactive beams simultaneously in the energy range from the keV to several tens of MeV/nucleons. The document details also the future contribution of Spiral-2 concerning the structure of exotic nuclei, the thermodynamical aspects of nuclear matter, nucleosynthesis, the fundamental basic interactions, and the use of neutrons. (A.C.)

  20. The rotation of spiral galaxies.

    Science.gov (United States)

    Rubin, V C

    1983-06-24

    There is accumulating evidence that as much as 90 percent of the mass of the universe is nonluminous and is clumped, halo-like, around individual galaxies. The gravitational force of this dark matter is presumed to be responsible for the high rotational velocities of stars and gas in the disks of spiral galaxie. At present, the form of the dark matter is unknown. Possible candidates span a range in mass of 10(70), from non-zero-mass neutrinos to massive black holes.

  1. Tool Wear Analysis on Five-Axis Flank Milling for Curved Shape Part – Full Flute and Ground Shank End Mill

    Directory of Open Access Journals (Sweden)

    Syahrul Azwan Sundi

    2017-01-01

    Full Text Available This paper is a study on full flute (extra-long tool and ground shank end mill wear analysis by utilizing five-axis CNC to implement flank milling strategy on curved shape part. Five-axis machining eases the user to implement variations of strategy such as flank milling. Flank milling is different from point milling. Point milling cuts materials by using the tip of the tool whereas the flank milling uses the cutting tool body to cut material. The type of cutting tool used was end mill 10 mm diameter with High Speed Steel (HSS material. One factor at a time was utilized to analyze the overall data. Feed rate and spindle speed were the two main factors that been set up equally for both full flute and ground shank end mill. At the end of this research, the qualitative analysis based on tool wear between full flute and ground shank end mill is observed. Generally, both types of cutting tools showed almost the same failure indication such as broken edge or chipped off edge, formation of pinned hole on the surface and serration formation or built-up edge (BUE on the primary flute. However, the results obtained from the enlarged images which were captured by Optical Microscope indicated that, the ground shank end mill is better than the full flute end mill.

  2. Parotid-Absorbed Doses: A Comparison Between Spiral Tomography and Panoramic

    Directory of Open Access Journals (Sweden)

    Ehsan Hekmatian

    2016-07-01

    Full Text Available Background Jaws spiral tomography and panoramic radiography have wide applications in dentistry, and the parotid gland is one of the most sensitive organs of the head and neck. Objectives The aim of this study was to evaluate and compare the parotid-absorbed dose in spiral tomography and panoramic radiographs using a thermoluminescent dosimeter. Materials and Methods A radiation analog dosimetry phantom was placed in a Cranex Tome radiograph device, and a parotid absorbed dose was measured in both techniques. Thermoluminescent dosimeters were placed bilaterally in the parotid region (on the tube side and the opposite side. Spiral tomography dosimetry was done for the upper and lower jaws in the anterior and posterior regions. Each region contained four slices of 2 mm and four slices of 4 mm in thickness. The results were analyzed by a Wilcoxon test. Results For the tube side parotid, the average absorbed doses in spiral tomography of the anterior and posterior parts of the maxilla and mandible, with the 2 mm slice thickness, were 1.70/1.40 and 1.65/1.60 mGy, respectively. The average absorbed doses with the 4mm slices were 1.65/1.70 and 1.75/1.57 mGy, respectively. For the opposite parotid, the average absorbed dose in spiral tomography of the anterior and posterior parts of the maxilla and mandible, with the 2 mm slice thickness, were 1.40/1.30 and 1.40/1.67 mGy, respectively. The average absorbed doses with the 4mm slices were 1.50/1.66 and 1.40/1.50 mGy, respectively. The average absorbed dose of the panoramic radiograph was 1.40 mGy. Conclusions There was no statistically significant difference in the parotid absorbed dose between spiral tomography and a panoramic radiograph (P value = 0.18. The overall results of this study were similar to other studies.

  3. Recruitment constraints in Singapore's fluted giant clam (Tridacna squamosa population--a dispersal model approach.

    Directory of Open Access Journals (Sweden)

    Mei Lin Neo

    Full Text Available Recruitment constraints on Singapore's dwindling fluted giant clam, Tridacna squamosa, population were studied by modelling fertilisation, larval transport, and settlement using real-time hydrodynamic forcing combined with knowledge of spawning characteristics, larval development, behaviour, and settlement cues. Larval transport was simulated using a finite-volume advection-diffusion model coupled to a three-dimensional hydrodynamic model. Three recruitment constraint hypotheses were tested: 1 there is limited connectivity between Singapore's reefs and other reefs in the region, 2 there is limited exchange within Singapore's Southern Islands, and 3 there exist low-density constraints to fertilisation efficacy (component Allee effects. Results showed that connectivity among giant clam populations was primarily determined by residual hydrodynamic flows and spawning time, with greatest chances of successful settlement occurring when spawning and subsequent larval dispersal coincided with the period of lowest residual flow. Simulations suggested poor larval transport from reefs located along the Peninsular Malaysia to Singapore, probably due to strong surface currents between the Andaman Sea and South China Sea combined with a major land barrier disrupting larval movement among reefs. The model, however, predicted offshore coral reefs to the southeast of Singapore (Bintan and Batam may represent a significant source of larvae. Larval exchange within Singapore's Southern Islands varied substantially depending on the locations of source and sink reefs as well as spawning time; but all simulations resulted in low settler densities (2.1-68.6 settled individuals per 10,000 m(2. Poor fertilisation rates predicted by the model indicate that the low density and scattered distribution of the remaining T. squamosa in Singapore are likely to significantly inhibit any natural recovery of local stocks.

  4. The DESIR Facility at SPIRAL2

    Indian Academy of Sciences (India)

    Beams from the low-energy branch of the separator spectrometer S3 and from SPIRAL1 will allow complementary studies of refrac- tory elements produced by means of fusion reactions as well as of light and intense exotic beams, respectively. Keywords. SPIRAL2; low-energy facility; nuclear physics; weak interaction; astro-.

  5. ANGULAR-MOMENTUM IN BINARY SPIRAL GALAXIES

    NARCIS (Netherlands)

    OOSTERLOO, T

    In order to investigate the relative orientations of spiral galaxies in pairs, the distribution of the angle between the spin-vectors for a new sample of 40 binary spiral galaxies is determined. From this distribution it is found, contrary to an earlier result obtained by Helou (1984), that there is

  6. Scaling effects in spiral capsule robots.

    Science.gov (United States)

    Liang, Liang; Hu, Rong; Chen, Bai; Tang, Yong; Xu, Yan

    2017-04-01

    Spiral capsule robots can be applied to human gastrointestinal tracts and blood vessels. Because of significant variations in the sizes of the inner diameters of the intestines as well as blood vessels, this research has been unable to meet the requirements for medical applications. By applying the fluid dynamic equations, using the computational fluid dynamics method, to a robot axial length ranging from 10 -5 to 10 -2  m, the operational performance indicators (axial driving force, load torque, and maximum fluid pressure on the pipe wall) of the spiral capsule robot and the fluid turbulent intensity around the robot spiral surfaces was numerically calculated in a straight rigid pipe filled with fluid. The reasonableness and validity of the calculation method adopted in this study were verified by the consistency of the calculated values by the computational fluid dynamics method and the experimental values from a relevant literature. The results show that the greater the fluid turbulent intensity, the greater the impact of the fluid turbulence on the driving performance of the spiral capsule robot and the higher the energy consumption of the robot. For the same level of size of the robot, the axial driving force, the load torque, and the maximum fluid pressure on the pipe wall of the outer spiral robot were larger than those of the inner spiral robot. For different requirements of the operating environment, we can choose a certain kind of spiral capsule robot. This study provides a theoretical foundation for spiral capsule robots.

  7. QS Spiral: Visualizing Periodic Quantified Self Data

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Cuttone, Andrea; Jørgensen, Sune Lehmann

    2013-01-01

    In this paper we propose an interactive visualization technique QS Spiral that aims to capture the periodic properties of quantified self data and let the user explore those recurring patterns. The approach is based on time-series data visualized as a spiral structure. The interactivity includes ...

  8. Numerical investigation on the convective heat transfer in a spiral coil with radiant heating

    Directory of Open Access Journals (Sweden)

    Đorđević Milan Lj.

    2016-01-01

    Full Text Available The objective of this study was to numerically investigate the heat transfer in spiral coil tube in the laminar, transitional, and turbulent flow regimes. The Archimedean spiral coil was exposed to radiant heating and should represent heat absorber of parabolic dish solar concentrator. Specific boundary conditions represent the uniqueness of this study, since the heat flux upon the tube external surfaces varies not only in the circumferential direction, but also in the axial direction. The curvature ratio of spiral coil varies from 0.029 at the flow inlet to 0.234 at the flow outlet, while the heat transfer fluid is water. The 3-D steady-state transport equations were solved using the Reynolds stress turbulence model. Results showed that secondary flows strongly affect the flow and that the heat transfer is strongly asymmetric, with higher values near the outer wall of spiral. Although overall turbulence levels were lower than in a straight pipe, heat transfer rates were larger due to the curvature-induced modifications of the mean flow and temperature fields. [Projekat Ministarstva nauke Republike Srbije, br. 42006

  9. Enteroelysis and spiral CT examination in diagnosis and evaluation of small bowel Crohn's disease

    International Nuclear Information System (INIS)

    Mako, E.K.; Mester, A.R.; Tarjan, Zs.; Karlinger, K.; Toth, G.

    2000-01-01

    Introduction: During the last few decades introducing many of new radiologic methods, diagnostic conditions and facilities of Crohn's disease has became markedly improved. Appropriate using of these techniques definitely modifies the management of patients with known or suspected Crohn's disease serving reliable information about extent, severity and possible complications of disease. Enteroclysis and Computed tomography are the two major and basic methods to disclose or confirm diagnosis of Crohn's disease, obtain appropriate inforination about disease either with mucosal, transmural or extraintestinal manifestation. Methods and patients: We evaluated 281 patients who were referred in our institution under suspicion of Crohn's disease. Enteroclysis and abdominal spiral CT in all cases were carried out usually within 1 week. The 172 patients underwent abdominal spiral CT as the primary examination to evaluate diagnostic value of spiral CT in this entity, while 109 patients had enteroclysis followed by abdominal CT. In 11 cases we also perforined CT enteroclysis with administration of 0.5% methylcellulose solution thorough nasojejunal tube controlled by electric motor driven contrast pump. Results were compared with final clinical, pathological or surgical data were available. Results: From the 281 patients eventually 74 proved Crohn's disease; sensitivity and specificity of enteroclysis proved to be 96 and 98%, while spiral CT sensitivity and specificity was 94 and 95%, respectively. Enteroclysis was superior to the spiral CT in demonstration of early lesions and functional disorders, while spiral CT proved to be essential in evaluation of transmural and extraintestinal complications. Conclusions: Regarding enteroclysis and spiral CT as complementary methods, they provide excellent results in diagnosis of Crohn's disease

  10. Analisa Kekuatan Spiral Bevel Gear Dengan Variasi Sudut Spiral Menggunakan Metode Elemen Hingga

    Directory of Open Access Journals (Sweden)

    Deta Rachmat Andika

    2017-01-01

    Full Text Available Seiring perkembangan zaman,  teknologi roda gigi dituntut untuk mampu mentransmisikan daya yang besar dengan efisiensi yang besar pula. Pada jenis intersecting shaft gear, tipe roda gigi payung spiral (spiral bevel gear  merupakan perkembangan dari roda gigi payung bergigi lurus (straight bevel gear. Kelebihan dari spiral bevel gear antara  lain adalah kemampuan transmisi daya dan efisiensi yang lebih besar pada geometri yang sama serta tidak terlalu berisik. Akan tetapi spiral bevel gear juga mempunyai kelemahan jika dibandingkan dengan straight bevel gear. Selain proses manufaktur yang lebih rumit, profil lengkung gigi spiral ini membuat distribusi tegangan yang terjadi menjadi lebih rumit untuk dimodelkan dengan persamaan matematika. Salah satu pendekatan yang dapat dilakukan adalah dengan menggunakan metode elemen hingga. Penelitian diawali dengan membuat model dari straight bevel gear dan juga spiral bevel gear yang sudut spiralnya divariasikan 20, 35, dan 45 derajat. Model dibuat dengan dimensi yang sama baik diameter maupun jumlah gigi gear. Langkah selanjutnya yaitu perhitungan analitis pada straight bevel gear dimana hasilnya akan dibandingkan dengan hasil simulasi statis. Setelah eror yang terjadi dibawah 15% maka dilakukan simulasi dinamis pada semua model yang telah dibuat yaitu straight bevel dan juga spira bevel gear. Hasil yang didapatkan dari penelitian ini adalah secara keseluruhan spiral bevel gear lebih kuat daripada straight bevel gear pada dimensi dan beban yang sama jika dilihat dari lebih kecilnya tegangan bending dan tegangan kontak maksimum yang terjadi. Tegangan terbesar terjadi pada jenis straight bevel gear baik pada tegangan bending maupun tegangan kontak sedangkan spiral bevel gear dengan variasi sudut Seiring spiral 35 mempunyai nilai tegangan terkecil. Prosntase selisih tegangan bending maksimum yang terjadi antara straight bevel gear dan spiral bevel gear dengan variasi sudut spiral 35 derajat  sebesar 44

  11. On Density Waves in Spiral Galaxies

    Science.gov (United States)

    Grosbol, P.; Patsis, P. A.

    The spiral structure of five ordinary spiral galaxies was studied using deep BVIK' surface photometry maps obtained at the 2.2m ESO/MPI telescope. The detailed shape of the arms was analyzed in terms of the spiral density wave theory. Grand design spirals were found on the K' maps in all five galaxies although at least two would be classified as flocculent on the blue images. In several of the galaxies, bulges with weak oval distortion (~10%) were observed. Dust spirals also continue, in some cases, inside the ILR where the stellar arms terminate. This emphasizes the strong bias of morphological classifications of spiral galaxies based on blue image due to dust and young stars. The 2--armed spirals were systematically found to be wound tighter on I than on K' maps suggesting the existence of a density wave. Locations of the ILR and the 4/1 resonance were estimated based on the arm morphology and the amplitude ratio between the m = 2,4 Fourier components. The wavenumber of the stellar 2--armed pattern is increasing towards the ILR which could suggest that the density wave is associated to the long waved branch of the dispersion relation. A possible scenario is discussed.

  12. Spiral arms in thermally stratified protoplanetary discs

    Science.gov (United States)

    Juhász, Attila; Rosotti, Giovanni P.

    2018-02-01

    Spiral arms have been observed in nearly a dozen protoplanetary discs in near-infrared scattered light and recently also in the submillimetre continuum. While one of the most compelling explanations is that they are driven by planetary or stellar companions, in all but one cases such companions have not yet been detected and there is even ambiguity on whether the planet should be located inside or outside the spirals. Here, we use 3D hydrodynamic simulations to study the morphology of spiral density waves launched by embedded planets taking into account the vertical temperature gradient, a natural consequence of stellar irradiation. Our simulations show that the pitch angle of the spirals in thermally stratified discs is the lowest in the disc mid-plane and increases towards the disc surface. We combine the hydrodynamic simulations with 3D radiative transfer calculations to predict that the pitch angle of planetary spirals observed in the near-infrared is higher than in the submillimetre. We also find that in both cases the spirals converge towards the planet. This provides a new powerful observational method to determine if the perturbing planet is inside or outside the spirals, as well as map the thermal stratification of the disc.

  13. Monitoring gaseous CO2 and ethanol above champagne glasses: flute versus coupe, and the role of temperature.

    Directory of Open Access Journals (Sweden)

    Gérard Liger-Belair

    Full Text Available In champagne tasting, gaseous CO(2 and volatile organic compounds progressively invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. Simultaneous quantification of gaseous CO(2 and ethanol was monitored through micro-gas chromatography (μGC, all along the first 15 minutes following pouring, depending on whether a volume of 100 mL of champagne was served into a flute or into a coupe. The concentration of gaseous CO(2 was found to be significantly higher above the flute than above the coupe. Moreover, a recently developed gaseous CO(2 visualization technique based on infrared imaging was performed, thus confirming this tendency. The influence of champagne temperature was also tested. As could have been expected, lowering the temperature of champagne was found to decrease ethanol vapor concentrations in the headspace of a glass. Nevertheless, and quite surprisingly, this temperature decrease had no impact on the level of gaseous CO(2 found above the glass. Those results were discussed on the basis of a multiparameter model which describes fluxes of gaseous CO(2 escaping the liquid phase into the form of bubbles.

  14. Monitoring gaseous CO2 and ethanol above champagne glasses: flute versus coupe, and the role of temperature.

    Science.gov (United States)

    Liger-Belair, Gérard; Bourget, Marielle; Pron, Hervé; Polidori, Guillaume; Cilindre, Clara

    2012-01-01

    In champagne tasting, gaseous CO(2) and volatile organic compounds progressively invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. Simultaneous quantification of gaseous CO(2) and ethanol was monitored through micro-gas chromatography (μGC), all along the first 15 minutes following pouring, depending on whether a volume of 100 mL of champagne was served into a flute or into a coupe. The concentration of gaseous CO(2) was found to be significantly higher above the flute than above the coupe. Moreover, a recently developed gaseous CO(2) visualization technique based on infrared imaging was performed, thus confirming this tendency. The influence of champagne temperature was also tested. As could have been expected, lowering the temperature of champagne was found to decrease ethanol vapor concentrations in the headspace of a glass. Nevertheless, and quite surprisingly, this temperature decrease had no impact on the level of gaseous CO(2) found above the glass. Those results were discussed on the basis of a multiparameter model which describes fluxes of gaseous CO(2) escaping the liquid phase into the form of bubbles.

  15. Corrosion of Spiral Rib Aluminized Pipe

    Science.gov (United States)

    2012-08-01

    Large diameter, corrugated steel pipes are a common sight in the culverts that run alongside many Florida roads. Spiral-ribbed aluminized pipe (SRAP) has been widely specified by the Florida Department of Transportation (FDOT) for runoff drainage. Th...

  16. Corrosion of Spiral Rib Aluminized Pipe : [Summary

    Science.gov (United States)

    2012-01-01

    Large diameter, corrugated steel pipes are a common sight in the culverts that run alongside many Florida roads. Spiral-ribbed aluminized pipe (SRAP) has been widely specified by the Florida Department of Transportation (FDOT) for runoff drainage. Th...

  17. Magnetic spiral arms in galaxy haloes

    Science.gov (United States)

    Henriksen, R. N.

    2017-08-01

    We seek the conditions for a steady mean field galactic dynamo. The parameter set is reduced to those appearing in the α2 and α/ω dynamo, namely velocity amplitudes, and the ratio of sub-scale helicity to diffusivity. The parameters can be allowed to vary on conical spirals. We analyse the mean field dynamo equations in terms of scale invariant logarithmic spiral modes and special exact solutions. Compatible scale invariant gravitational spiral arms are introduced and illustrated in an appendix, but the detailed dynamical interaction with the magnetic field is left for another work. As a result of planar magnetic spirals `lifting' into the halo, multiple sign changes in average rotation measures forming a regular pattern on each side of the galactic minor axis, are predicted. Such changes have recently been detected in the Continuum Halos in Nearby Galaxies-an EVLA Survey (CHANG-ES) survey.

  18. Cylindrical spirals in human skeletal muscle.

    Science.gov (United States)

    Carpenter, S; Karpati, G; Robitaille, Y; Melmed, C

    1979-01-01

    Muscle biopsies from two patients revealed that numerous type 2 fibers contained large abnormal areas filled with cylindrical spirals. The cytochemical profile of these cylindrical spirals was sufficiently characteristic that they could be distinguished from tubular aggregates. Their electron microscopic appearance was unmistakable. Their origin and significance are uncertain. The diverse nature of the patients' conditions (cramps and malignancy, and an unusual form of spinocerebellar degeneration) indicate that these abnormal structures are not disease specific.

  19. Wavelet Scattering on the Pitch Spiral

    OpenAIRE

    Lostanlen, Vincent; Mallat, Stéphane

    2016-01-01

    We present a new representation of harmonic sounds that linearizes the dynamics of pitch and spectral envelope, while remaining stable to deformations in the time-frequency plane. It is an instance of the scattering transform, a generic operator which cascades wavelet convolutions and modulus nonlinearities. It is derived from the pitch spiral, in that convolutions are successively performed in time, log-frequency, and octave index. We give a closed-form approximation of spiral scattering coe...

  20. Ear Tubes

    Science.gov (United States)

    ... of the ear drum or eustachian tube, Down Syndrome, cleft palate, and barotrauma (injury to the middle ear caused by a reduction of air pressure, ... specialist) may be warranted if you or your child has experienced repeated ... fluid in the middle ear, barotrauma, or have an anatomic abnormality that ...

  1. Dark matter in spiral galaxies

    International Nuclear Information System (INIS)

    Albada, T.S. van; Sancisi, R.

    1986-01-01

    Mass models of spiral galaxies based on the observed light distribution, assuming constant M/L for bulge and disc, are able to reproduce the observed rotation curves in the inner regions, but fail to do so increasingly towards and beyond the edge of the visible material. The discrepancy in the outer region can be accounted for by invoking dark matter; some galaxies require at least four times as much dark matter as luminous matter. There is no evidence for a dependence on galaxy luminosity or morphological type. Various arguments support the idea that a distribution of visible matter with constant M/L is responsible for the circular velocity in the inner region, i.e. inside approximately 2.5 disc scalelengths. Luminous matter and dark matter seem to 'conspire' to produce the flat observed rotation curves in the outer region. It seems unlikely that this coupling between disc and halo results from the large-scale gravitational interaction between the two components. Attempts to determine the shape of dark halos have not yet produced convincing results. (author)

  2. SIGNATURES OF LONG-LIVED SPIRAL PATTERNS

    International Nuclear Information System (INIS)

    Martínez-García, Eric E.; González-Lópezlira, Rosa A.

    2013-01-01

    Azimuthal age/color gradients across spiral arms are a signature of long-lived spirals. From a sample of 19 normal (or weakly barred) spirals where we have previously found azimuthal age/color gradient candidates, 13 objects were further selected if a two-armed grand-design pattern survived in a surface density stellar mass map. Mass maps were obtained from optical and near-infrared imaging, by comparison with a Monte Carlo library of stellar population synthesis models that allowed us to obtain the mass-to-light ratio in the J band, (M/L) J , as a function of (g – i) versus (i – J) color. The selected spirals were analyzed with Fourier methods in search of other signatures of long-lived modes related to the gradients, such as the gradient divergence toward corotation, and the behavior of the phase angle of the two-armed spiral in different wavebands, as expected from theory. The results show additional signatures of long-lived spirals in at least 50% of the objects.

  3. SIGNATURES OF LONG-LIVED SPIRAL PATTERNS

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Garcia, Eric E. [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Aptdo. Postal 51 y 216, 72000 Puebla, Pue. (Mexico); Gonzalez-Lopezlira, Rosa A., E-mail: ericmartinez@inaoep.mx, E-mail: martinez@astro.unam.mx, E-mail: r.gonzalez@crya.unam.mx [Centro de Radioastronomia y Astrofisica, UNAM, Campus Morelia, Michoacan, C.P. 58089 (Mexico)

    2013-03-10

    Azimuthal age/color gradients across spiral arms are a signature of long-lived spirals. From a sample of 19 normal (or weakly barred) spirals where we have previously found azimuthal age/color gradient candidates, 13 objects were further selected if a two-armed grand-design pattern survived in a surface density stellar mass map. Mass maps were obtained from optical and near-infrared imaging, by comparison with a Monte Carlo library of stellar population synthesis models that allowed us to obtain the mass-to-light ratio in the J band, (M/L){sub J}, as a function of (g - i) versus (i - J) color. The selected spirals were analyzed with Fourier methods in search of other signatures of long-lived modes related to the gradients, such as the gradient divergence toward corotation, and the behavior of the phase angle of the two-armed spiral in different wavebands, as expected from theory. The results show additional signatures of long-lived spirals in at least 50% of the objects.

  4. Chiralities of spiral waves and their transitions

    Science.gov (United States)

    Pan, Jun-ting; Cai, Mei-chun; Li, Bing-wei; Zhang, Hong

    2013-06-01

    The chiralities of spiral waves usually refer to their rotation directions (the turning orientations of the spiral temporal movements as time elapses) and their curl directions (the winding orientations of the spiral spatial geometrical structures themselves). Traditionally, they are the same as each other. Namely, they are both clockwise or both counterclockwise. Moreover, the chiralities are determined by the topological charges of spiral waves, and thus they are conserved quantities. After the inwardly propagating spirals were experimentally observed, the relationship between the chiralities and the one between the chiralities and the topological charges are no longer preserved. The chiralities thus become more complex than ever before. As a result, there is now a desire to further study them. In this paper, the chiralities and their transition properties for all kinds of spiral waves are systemically studied in the framework of the complex Ginzburg-Landau equation, and the general relationships both between the chiralities and between the chiralities and the topological charges are obtained. The investigation of some other models, such as the FitzHugh-Nagumo model, the nonuniform Oregonator model, the modified standard model, etc., is also discussed for comparison.

  5. Continuous enzyme reactions with immobilized enzyme tubes prepared by radiation cast-polymerization

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Kaetsu, Isao

    1986-01-01

    Immobilized glucose oxidase tubes were prepared by radiation cast-polymerization of 2-hydroxyethyl methacrylate and tetraethyleneglycol diacrylate monomer at low temperatures. The immobilized enzyme tubes which were spirally set in a water bath were used as reactor, in which the enzyme activity varied with tube size and flow rate of the substrate. The conversion yield of the substrate in continuous enzyme reaction was about 80%. (author)

  6. Six Decades of Spiral Density Wave Theory

    Science.gov (United States)

    Shu, Frank H.

    2016-09-01

    The theory of spiral density waves had its origin approximately six decades ago in an attempt to reconcile the winding dilemma of material spiral arms in flattened disk galaxies. We begin with the earliest calculations of linear and nonlinear spiral density waves in disk galaxies, in which the hypothesis of quasi-stationary spiral structure (QSSS) plays a central role. The earliest success was the prediction of the nonlinear compression of the interstellar medium and its embedded magnetic field; the earliest failure, seemingly, was not detecting color gradients associated with the migration of OB stars whose formation is triggered downstream from the spiral shock front. We give the reasons for this apparent failure with an update on the current status of the problem of OB star formation, including its relationship to the feathering substructure of galactic spiral arms. Infrared images can show two-armed, grand design spirals, even when the optical and UV images show flocculent structures. We suggest how the nonlinear response of the interstellar gas, coupled with overlapping subharmonic resonances, might introduce chaotic behavior in the dynamics of the interstellar medium and Population I objects, even though the underlying forces to which they are subject are regular. We then move to a discussion of resonantly forced spiral density waves in a planetary ring and their relationship to the ideas of disk truncation, and the shepherding of narrow rings by satellites orbiting nearby. The back reaction of the rings on the satellites led to the prediction of planet migration in protoplanetary disks, which has had widespread application in the exploding data sets concerning hot Jupiters and extrasolar planetary systems. We then return to the issue of global normal modes in the stellar disk of spiral galaxies and its relationship to the QSSS hypothesis, where the central theoretical concepts involve waves with negative and positive surface densities of energy and angular

  7. Establishing Decision Trees for Predicting Successful Postpyloric Nasoenteric Tube Placement in Critically Ill Patients.

    Science.gov (United States)

    Chen, Weisheng; Sun, Cheng; Wei, Ru; Zhang, Yanlin; Ye, Heng; Chi, Ruibin; Zhang, Yichen; Hu, Bei; Lv, Bo; Chen, Lifang; Zhang, Xiunong; Lan, Huilan; Chen, Chunbo

    2016-08-31

    Despite the use of prokinetic agents, the overall success rate for postpyloric placement via a self-propelled spiral nasoenteric tube is quite low. This retrospective study was conducted in the intensive care units of 11 university hospitals from 2006 to 2016 among adult patients who underwent self-propelled spiral nasoenteric tube insertion. Success was defined as postpyloric nasoenteric tube placement confirmed by abdominal x-ray scan 24 hours after tube insertion. Chi-square automatic interaction detection (CHAID), simple classification and regression trees (SimpleCart), and J48 methodologies were used to develop decision tree models, and multiple logistic regression (LR) methodology was used to develop an LR model for predicting successful postpyloric nasoenteric tube placement. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of these models. Successful postpyloric nasoenteric tube placement was confirmed in 427 of 939 patients enrolled. For predicting successful postpyloric nasoenteric tube placement, the performance of the 3 decision trees was similar in terms of the AUCs: 0.715 for the CHAID model, 0.682 for the SimpleCart model, and 0.671 for the J48 model. The AUC of the LR model was 0.729, which outperformed the J48 model. Both the CHAID and LR models achieved an acceptable discrimination for predicting successful postpyloric nasoenteric tube placement and were useful for intensivists in the setting of self-propelled spiral nasoenteric tube insertion. © 2016 American Society for Parenteral and Enteral Nutrition.

  8. Establishing Decision Trees for Predicting Successful Postpyloric Nasoenteric Tube Placement in Critically Ill Patients.

    Science.gov (United States)

    Chen, Weisheng; Sun, Cheng; Wei, Ru; Zhang, Yanlin; Ye, Heng; Chi, Ruibin; Zhang, Yichen; Hu, Bei; Lv, Bo; Chen, Lifang; Zhang, Xiunong; Lan, Huilan; Chen, Chunbo

    2018-01-01

    Despite the use of prokinetic agents, the overall success rate for postpyloric placement via a self-propelled spiral nasoenteric tube is quite low. This retrospective study was conducted in the intensive care units of 11 university hospitals from 2006 to 2016 among adult patients who underwent self-propelled spiral nasoenteric tube insertion. Success was defined as postpyloric nasoenteric tube placement confirmed by abdominal x-ray scan 24 hours after tube insertion. Chi-square automatic interaction detection (CHAID), simple classification and regression trees (SimpleCart), and J48 methodologies were used to develop decision tree models, and multiple logistic regression (LR) methodology was used to develop an LR model for predicting successful postpyloric nasoenteric tube placement. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of these models. Successful postpyloric nasoenteric tube placement was confirmed in 427 of 939 patients enrolled. For predicting successful postpyloric nasoenteric tube placement, the performance of the 3 decision trees was similar in terms of the AUCs: 0.715 for the CHAID model, 0.682 for the SimpleCart model, and 0.671 for the J48 model. The AUC of the LR model was 0.729, which outperformed the J48 model. Both the CHAID and LR models achieved an acceptable discrimination for predicting successful postpyloric nasoenteric tube placement and were useful for intensivists in the setting of self-propelled spiral nasoenteric tube insertion. © 2016 American Society for Parenteral and Enteral Nutrition.

  9. Some INDRA experiments on SPIRAL

    International Nuclear Information System (INIS)

    Cussol, D.; Orr, N.A.

    1997-01-01

    A panel joining members of INDRA collaboration and physicists off collaboration was gathered to debate the question whether the INDRA detector, designed to study multifragmentation with beams of stable nuclei, could be used also in experiments with beams of exotic nuclei. Four experiments were discussed as well as the implied detector modifications. In the frame of experiments with SISSI the study of the multifragmentation as a function of N/Z of the system should answer questions related to the system stability as a function of N/Z and origin of the particles emitted during the collision. Among the experiments with SPIRAL to study de-excitation of hot nuclei the following topics were examined: nuclear stability as a function of N/Z, α-n competition, emission of neutron-rich particles as a function of N/Z, evolution of emission modes near the shell closure. The de-excitation of the resonant excited states through 2p decay will be studied in the following three channels: 1p-1p sequential decay, un-correlated simultaneous 2p emission and correlated simultaneous 2p emission ( 2 He emission). Such experiments were carried out on 6 Be, 12 O and 14 O. The only first two channels were observed so far. The 16 Ne could be a good candidate to observe the third channel. Finally sub-barrier Coulomb fusion experiments were also discussed. Concerning the modifications to be undertaken on INDRA detector two were obvious: a modification at the level of electronics to make possible time-of-flight measurements with silicon detectors and transformations of ionization chambers in Bragg chambers. Simulation studies are under way to test the pertinence and validity of the solution

  10. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo [Hercules, CA; Lou, Tak Pui [Berkeley, CA; Reijonen, Jani [Oakland, CA

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  11. Difficulty with cuff deflation of reinforced tracheal tube caused by inflation line occlusion with silk thread ligation and fixation.

    Science.gov (United States)

    Gotoh, Sayoko; Sugiyama, Daisuke; Imai, Eriko; Kawamata, Mikito

    2015-03-05

    A reinforced tracheal tube, ligated with silk threads, was inserted into a tracheostomy orifice and fixed to the skin. The cuff inflation line of the reinforced tracheal tube became occluded. Reinforced 'armoured' tracheal tubes have a spiral of wire embedded into the wall of the tube to give strength and flexibility, and may be sharply bent without compromising the tube lumen. The tracheal cuff attached to the tube is inflated by injecting air through a narrow-diameter tube welded to the outside of the tracheal tube. When a reinforced tracheal tube is ligated and fixed with silk threads, it should be confirmed whether the tracheal tube cuff can be deflated and inflated after fixation. Moreover, because occlusion can be eliminated by removing all silk threads used to ligate a tracheal tube, they should be removed before extubation. 2015 BMJ Publishing Group Ltd.

  12. Galaxy Zoo: dust in spiral galaxies

    Science.gov (United States)

    Masters, Karen L.; Nichol, Robert; Bamford, Steven; Mosleh, Moein; Lintott, Chris J.; Andreescu, Dan; Edmondson, Edward M.; Keel, William C.; Murray, Phil; Raddick, M. Jordan; Schawinski, Kevin; Slosar, Anže; Szalay, Alexander S.; Thomas, Daniel; Vandenberg, Jan

    2010-05-01

    We investigate the effect of dust on spiral galaxies by measuring the inclination dependence of optical colours for 24276 well-resolved Sloan Digital Sky Survey (SDSS) galaxies visually classified via the Galaxy Zoo project. We find clear trends of reddening with inclination which imply a total extinction from face-on to edge-on of 0.7, 0.6, 0.5 and 0.4mag for the ugri passbands (estimating 0.3mag of extinction in z band). We split the sample into `bulgy' (early-type) and `discy' (late-type) spirals using the SDSS fracdeV (or fDeV) parameter and show that the average face-on colour of `bulgy' spirals is redder than the average edge-on colour of `discy' spirals. This shows that the observed optical colour of a spiral galaxy is determined almost equally by the spiral type (via the bulge-disc ratio and stellar populations), and reddening due to dust. We find that both luminosity and spiral type affect the total amount of extinction, with discy spirals at Mr ~ -21.5mag having the most reddening - more than twice as much as both the lowest luminosity and most massive, bulge-dominated spirals. An increase in dust content is well known for more luminous galaxies, but the decrease of the trend for the most luminous has not been observed before and may be related to their lower levels of recent star formation. We compare our results with the latest dust attenuation models of Tuffs et al. We find that the model reproduces the observed trends reasonably well but overpredicts the amount of u-band attenuation in edge-on galaxies. This could be an inadequacy in the Milky Way extinction law (when applied to external galaxies), but more likely indicates the need for a wider range of dust-star geometries. We end by discussing the effects of dust on large galaxy surveys and emphasize that these effects will become important as we push to higher precision measurements of galaxy properties and their clustering. This publication has been made possible by the participation of more than

  13. Investigations on high-pressure ribbed tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kling, G.

    1942-05-01

    During hydrogenation of coal, the reactants (coal paste and hydrogen) had to be heated to reaction temperature partly by heat exchange with products and partly by heating in hairpin tubes of a preheater. These hairpin tubes were heated externally by hot circulating gases. In order to improve heat transfer from the gases to the tubes, various types of metal ribbing were welded to the tubes to catch more heat and transfer it to the tubes. This report detailed some studies on the best shapes and dimensions and numbers of plates to be used. The report was limited to flat, rectangular-cross-section plates attached perpendicularly, instead of including flat circular plates, spiral plates, or other configurations. The advantage of greater surface area to catch more heat had to be balanced off against the disadvantage of greater surface area to absorb more heat in internal resistance to heat flow. The report described the experimental conditions, the modifications tested, and the shape decided upon as best for flat plates. Some of the diagrams illustrating temperature distributions around the tubes and ribs were presented in imitation three-dimenional formats. 16 figures.

  14. Caenorhabditis elegans centriolar protein SAS-6 forms a spiral that is consistent with imparting a ninefold symmetry.

    Science.gov (United States)

    Hilbert, Manuel; Erat, Michèle C; Hachet, Virginie; Guichard, Paul; Blank, Iris D; Flückiger, Isabelle; Slater, Leanne; Lowe, Edward D; Hatzopoulos, Georgios N; Steinmetz, Michel O; Gönczy, Pierre; Vakonakis, Ioannis

    2013-07-09

    Centrioles are evolutionary conserved organelles that give rise to cilia and flagella as well as centrosomes. Centrioles display a characteristic ninefold symmetry imposed by the spindle assembly abnormal protein 6 (SAS-6) family. SAS-6 from Chlamydomonas reinhardtii and Danio rerio was shown to form ninefold symmetric, ring-shaped oligomers in vitro that were similar to the cartwheels observed in vivo during early steps of centriole assembly in most species. Here, we report crystallographic and EM analyses showing that, instead, Caenorhabotis elegans SAS-6 self-assembles into a spiral arrangement. Remarkably, we find that this spiral arrangement is also consistent with ninefold symmetry, suggesting that two distinct SAS-6 oligomerization architectures can direct the same output symmetry. Sequence analysis suggests that SAS-6 spirals are restricted to specific nematodes. This oligomeric arrangement may provide a structural basis for the presence of a central tube instead of a cartwheel during centriole assembly in these species.

  15. Spiral CT manifestations of spherical pneumonia

    International Nuclear Information System (INIS)

    Li Xiaohong; Yang Hongwei; Xu Chunmin; Qin Xiu

    2008-01-01

    Objective: To explore the Spiral CT manifestations and differential diagnosis of spherical pneumonia. Methods: 18 cases of spherical pneumonia and 20 cases of peripheral pulmonary carcinoma were selected, both of them were confirmed by clinic and/or pathology. The SCT findings of both groups were compared retrospectively. Results: Main spiral CT findings of spherical pneumonia were showed as followings: square or triangular lesions adjacent to pleura; with irregular shape, blurry, slightly lobulated margin, sometimes with halo sign. Small inflammatory patches and intensified vascular markings around the lesions were seen. Lesions became smaller or vanished after short-term anti-inflammatory treatment. Conclusion: Spherical pneumonia showed some characteristics on Spiral CT scan, which are helpful in diagnosis and differential diagnosis of this disease. (authors)

  16. photomultiplier tubes

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  17. photomultiplier tube

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  18. Graphite target for the spiral project

    Energy Technology Data Exchange (ETDEWEB)

    Putaux, J.C.; Ducourtieux, M.; Ferro, A.; Foury, P.; Kotfila, L.; Mueller, A.C.; Obert, J.; Pauwels, N.; Potier, J.C.; Proust, J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Bertrand, P. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Loiselet, M. [Universite Catholique de Louvain, Louvain-La-Neuve (Belgium)] [and others

    1996-12-31

    A study of the thermal and physical properties of graphite targets for the SPIRAL project is presented. The main objective is to develop an optimized set-up both mechanically and thermally resistant, presenting good release properties (hot targets with thin slices). The results of irradiation tests concerning the mechanical and thermal resistance of the first prototype of SPIRAL target with conical geometry are presented. The micro-structural properties of the graphite target is also studied, in order to check that the release properties are not deteriorated by the irradiation. Finally, the results concerning the latest pilot target internally heated by an electrical current are shown. (author). 5 refs.

  19. Photometry and mass modeling of spiral galaxies

    International Nuclear Information System (INIS)

    Kent, S.

    1987-01-01

    Recent estimates of the relative contributions of dark and luminous matter to the mass of spiral galaxies are reviewed. In these studies, the galactic mass distribution is modeled on the basis of photometric and kinematic observational data. The accuracy of current photometry is discussed; the three-dimensional structure of spiral galaxies and the techniques used in bulge-disk decomposition are examined; and mass models incorporating rotation curves are presented. The disk mass/luminosity ratios in the red band (corrected for internal extinction) are found to range from 1.6 to 3.2, with no particular radius at which dark matter dominates. 20 references

  20. Sedimentation of an ellipsoidal particle in narrow tubes

    Science.gov (United States)

    Huang, Haibo; Yang, Xin; Lu, Xi-yun

    2014-05-01

    Sedimentation behaviours of an ellipsoidal particle in narrow and infinitely long tubes are studied by a multi-relaxation-time lattice Boltzmann method (LBM). In the present study, both circular and square tubes with 12/13 ⩽ D/A ⩽ 2.5 are considered with the Galileo number (Ga) up to 150, where D and A are the width of the tube and the length of major axis of the ellipsoid, respectively. Besides three modes of motion mentioned in the literature, two novel modes are found for the narrow tubes in the higher Ga regime: the spiral mode and the vertically inclined mode. Near a transitional regime, in terms of average settling velocity, it is found that a lighter ellipsoid may settle faster than a heavier one. The relevant mechanism is revealed. The behaviour of sedimentation inside the square tubes is similar to that in the circular tubes. One significant difference is that the translation and rotation of ellipsoid are finally constrained to a diagonal plane in the square tubes. The other difference is that the anomalous rolling mode occurs in the square tubes. In this mode, the ellipsoid rotates as if it is contacting and rolling up one corner of the square tube when it settles down. Two critical factors that induce this mode are identified: the geometry of the tube and the inertia of the ellipsoid.

  1. Numerical investigation of unsteady detonation waves in combustion chamber using Shchelkin spirals

    Directory of Open Access Journals (Sweden)

    Repaka Ramesh

    2016-09-01

    Full Text Available : Pulse Detonation Engine (PDE is considered to be a propulsive system of future air vehicles. The main objective is to minimizing the Deflagration to Detonation transition run-up distance and time by placing Shchelkin spiral with varying pitch length. Here we have considered blockage-area ratio is 0.5 as optimal value from review of previous studies. In the present study the detonation initiation and propagation is modeled numerically using commercial CFD codes GAMBIT and FLUENT. The unsteady and two-dimensional compressible Reynolds Averaged Navier-Stokes equation is used to simulate the model. Fuel-air mixture of Hydrogen-air is used for better efficiency of PDE. It is very simple straight tube with Shchelkin spirals, one of the methods which is used to initiate detonation is creation of high pressure and temperature chamber region with 0.5cm from closed end of tube where shock will generate and transition into low pressure and temperature region propagates towards end of the tube. Two different zones namely high and low pressure zones are used as interface in modeling and patching has been used to fill the zones with hydrogen and oxygen with different pressure and temperatures hence shock leads to propagate inside the combustion chamber.

  2. Adaptation of the control system in view of SPIRAL integration

    International Nuclear Information System (INIS)

    Lecorche, E.

    1998-01-01

    As soon as the collaboration between the SPIRAL project and the Control Group has been defined, the first implementation of the SPIRAL control system started following various directions. Both the global hardware and software architectures has been specified and some practical works have been undertaken such as the Ethernet network installation or the first SPIRAL oriented software design and coding. (authors)

  3. The dynamics of the spiral galaxy M81

    International Nuclear Information System (INIS)

    Visser, H.C.D.

    1978-01-01

    A detailed comparison of the observations of the spiral galaxy M81 with the density-wave theory for tightly-wound spirals is presented. In particular, hydrogen-line observations are compared with the nonlinear density-wave theory for the gas with the aim of constructing a density-wave model for the spiral galaxy M81

  4. Geometric studies on variable radius spiral cone-beam scanning

    International Nuclear Information System (INIS)

    Ye Yangbo; Zhu Jiehua; Wang Ge

    2004-01-01

    The goal is to perform geometric studies on cone-beam CT scanning along a three-dimensional (3D) spiral of variable radius. First, the background for variable radius spiral cone-beam scanning is given in the context of electron-beam CT/micro-CT. Then, necessary and sufficient conditions are proved for existence and uniqueness of PI lines inside the variable radius 3D spiral. These results are necessary steps toward exact cone-beam reconstruction from a 3D spiral scan of variable radius, adapting Katsevich's formula for the standard helical cone-beam scanning. It is shown in the paper that when the longitudinally projected planar spiral is not always convex toward the origin, the PI line may not be unique in the envelope defined by the tangents of the spiral. This situation can be avoided by using planar spirals whose curvatures are always positive. Using such a spiral, a longitudinally homogeneous region inside the corresponding 3D spiral is constructed in which any point is passed by one and only one PI line, provided the angle ω between planar spiral's tangent and radius is bounded by vertical bar ω-90 deg. vertical bar ≤ε for some positive ε≤32.48 deg. If the radius varies monotonically, this region is larger and one may allow ε≤51.85 deg. Examples for 3D spirals based on logarithmic and Archimedean spirals are given. The corresponding generalized Tam-Danielsson detection windows are also formulated

  5. A nutrient’s downstream spiral

    Science.gov (United States)

    Indicators of a stream’s ability to remove nutrients provide insights on watershed integrity and stream habitat characteristics that are needed to help managers to restore stream ecosystem services. We used the Tracer Additon Spiraling Characterization Curve (TASCC) to mea...

  6. The Distribution of Mass in Spiral Galaxies.

    NARCIS (Netherlands)

    Swaters, Rob; Andersen, David; Bershady, Matthew; Verheijen, Marc

    2002-01-01

    Little is known about the content and distribution of dark matter in spiral galaxies. Mass modeling of any rotation curve can yield an alarming range of results - from entirely halo-dominated, centrally- concentrated dark distributions, to disk-dominated inner potentials with shallow, low density

  7. The surface brightness of spiral galaxies

    International Nuclear Information System (INIS)

    Phillipps, S.; Disney, M.

    1983-01-01

    Correlations between optical surface brightness and the radio properties of spiral galaxies are investigated. It is found that galaxies with high surface brightness are more likely to be strong continuum radio sources and that galaxies with low surface brightness have high 21-cm line emission. (author)

  8. Logarithmic spiral trajectories generated by Solar sails

    Science.gov (United States)

    Bassetto, Marco; Niccolai, Lorenzo; Quarta, Alessandro A.; Mengali, Giovanni

    2018-02-01

    Analytic solutions to continuous thrust-propelled trajectories are available in a few cases only. An interesting case is offered by the logarithmic spiral, that is, a trajectory characterized by a constant flight path angle and a fixed thrust vector direction in an orbital reference frame. The logarithmic spiral is important from a practical point of view, because it may be passively maintained by a Solar sail-based spacecraft. The aim of this paper is to provide a systematic study concerning the possibility of inserting a Solar sail-based spacecraft into a heliocentric logarithmic spiral trajectory without using any impulsive maneuver. The required conditions to be met by the sail in terms of attitude angle, propulsive performance, parking orbit characteristics, and initial position are thoroughly investigated. The closed-form variations of the osculating orbital parameters are analyzed, and the obtained analytical results are used for investigating the phasing maneuver of a Solar sail along an elliptic heliocentric orbit. In this mission scenario, the phasing orbit is composed of two symmetric logarithmic spiral trajectories connected with a coasting arc.

  9. Importance of packing in spiral defect chaos

    Indian Academy of Sciences (India)

    We develop two measures to characterize the geometry of patterns exhibited by the state of spiral defect chaos, a weakly turbulent regime of Rayleigh-Bénard convection. These describe the packing of contiguous stripes within the pattern by quantifying their length and nearest-neighbor distributions. The distributions ...

  10. High-displacement spiral piezoelectric actuators

    Science.gov (United States)

    Mohammadi, F.; Kholkin, A. L.; Jadidian, B.; Safari, A.

    1999-10-01

    A high-displacement piezoelectric actuator, employing spiral geometry of a curved piezoelectric strip is described. The monolithic actuators are fabricated using a layered manufacturing technique, fused deposition of ceramics, which is capable of prototyping electroceramic components with complex shapes. The spiral actuators (2-3 cm in diameter) consisted of 4-5 turns of a lead zirconate titanate ceramic strip with an effective length up to 28 cm. The width was varied from 0.9 to 1.75 mm with a height of 3 mm. When driven by the electric field applied across the width of the spiral wall, the tip of the actuator was found to displace in both radial and tangential directions. The tangential displacement of the tip was about 210 μm under the field of 5 kV/cm. Both the displacement and resonant frequency of the spirals could be tailored by changing the effective length and wall width. The blocking force of the actuator in tangential direction was about 1 N under the field of 5 kV/cm. These properties are advantageous for high-displacement low-force applications where bimorph or monomorph actuators are currently employed.

  11. The Spiral Curriculum. Research into Practice

    Science.gov (United States)

    Johnston, Howard

    2012-01-01

    The Spiral Curriculum is predicated on cognitive theory advanced by Jerome Bruner (1960), who wrote, "We begin with the hypothesis that any subject can be taught in some intellectually honest form to any child at any stage of development." In other words, even the most complex material, if properly structured and presented, can be understood by…

  12. Nobeyama CO Atlas of Nearby Spiral Galaxies

    Science.gov (United States)

    Kuno, N.; Nakai, N.; Sorai, K.; Sato, N..; Yamauchi, A.; Tosaki, T.; Shioya, Y.; Vila-Vilaró, B.; Nishiyama, K.; Ishihara, Y.; Cepa, J.

    BEARS is a 25-beam focal plane array receiver mounted on the Nobeyama 45-m telescope. The combination of the large dish size of the telescope with the excellent performance of this receiver makes it an ideal tool for mapping observations of extended regions of the sky. We present here one of its current applications in a CO mapping survey of nearby spiral galaxies.

  13. A section of a spiral coal chute

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtin, V.N.; Gorodilov, N.N.

    1981-01-01

    A section of a spiral coal chute includes a housing with support brackets. It differs in that to decrease the amount of work necessary for assembly, each support bracket is made with a guide slot and equipped with a pull-out cantilever in the shape of a fork which covers the slot from the lateral sides.

  14. Biofouling of spiral wound membrane systems

    NARCIS (Netherlands)

    Vrouwenvelder, J.S.

    2009-01-01

    Biofouling of spiral wound membrane systems High quality drinking water can be produced with membrane filtration processes like reverse osmosis (RO) and nanofiltration (NF). Because the global demand for fresh clean water is increasing, these membrane technologies will increase in importance in the

  15. SPIRAL2 at GANIL: Status and Perspectives

    Science.gov (United States)

    Gales, S.

    2008-05-01

    To pursue the investigation of a new territory of nuclei with extreme N/Z called ``terra incognita'' several projects, all aiming at the increase by several orders of magnitude of the RIB intensities are now under discussions worldwide. In Europe, two major new projects have been approved recently FAIRatGSI using the so-called ``in-flight'' method and SPIRAL2atGANIL, based on the ISOL method. Both projects were selected in the European Strategic Roadmap For research Infrastructures (ESFRI). The main goal of SPIRAL2 is clearly to extend our knowledge of the limit of existence and the structure of nuclei deeply in the medium and heavy mass region (A = 60 to 140) which is to day an almost unexplored continent. SPIRAL 2 is based on a high power, CW, superconducting driver LINAC, delivering 5 mA of deuteron beams at 40 MeV (200 KW) directed on a C converter+ Uranium target and producing therefore more 1013 fissions/s. The expected radioactive beams intensities for exotic species in the mass range from A = 60 to A = 140, of the order of 106 to 1010 pps will surpass by two order of magnitude any existing facilities in the world. These unstable atoms will be available at energies between few KeV/n to 15 MeV/n. The same driver will accelerate high intensity (100 μA to 1 mA), heavier ions up to Ar at 14 MeV/n producing also proton rich exotic nuclei. In applied areas SPIRAL2 is considered as a powerful variable energy neutron source, a must to study the impact of nuclear fission and fusion on materials. The intensities of these unstable species are excellent opportunities for new tracers and diagnostics either for solid state, material or for radiobiological science and medicine. The ``Go'' decision has been taken in May 2005. The investments and personnel costs amount to 190 M€, for the construction period 2006-2012. Construction of the SPIRAL2 facility is shared by ten French laboratories and a network of international partners. Under the 7FP program of European Union

  16. X-ray tube transformer

    International Nuclear Information System (INIS)

    1980-01-01

    An X-ray generator is described which comprises a transmission line transformer including an electrical conductor with a cavity and a second electrical conductor including helical windings disposed along a longitudinal axis within the cavity of the first conductor. The windings have a pitch which varies per unit length along the axis. There is dielectric material in the cavity for insulation and to couple electromagnetically the two conductors in response to an electric current flowing through the conductors, which have an impedance between them; this varies with distance along the axis of the helix of the second conductor. An X-ray tube is disposed along the longitudinal axis within the cavity, for radiating X-rays. The invention increases the voltage of applied voltage pulses at the remote tube-head with a transformer formed by using a spiral delay line geometry to give a tapered-impedance coaxial high voltage multiplier for pulse voltage operation. This transformer is smaller and lighter than previous designs for the same high peak voltage and power ratings. This is important because the penetration capabilities of Flash X-ray equipment increase with voltage, particularly in heavy materials such as steel. (U.K.)

  17. Nutrient spiraling in streams and river networks

    Science.gov (United States)

    Ensign, Scott H.; Doyle, Martin W.

    2006-12-01

    Over the past 3 decades, nutrient spiraling has become a unifying paradigm for stream biogeochemical research. This paper presents (1) a quantitative synthesis of the nutrient spiraling literature and (2) application of these data to elucidate trends in nutrient spiraling within stream networks. Results are based on 404 individual experiments on ammonium (NH4), nitrate (NO3), and phosphate (PO4) from 52 published studies. Sixty-nine percent of the experiments were performed in first- and second-order streams, and 31% were performed in third- to fifth-order streams. Uptake lengths, Sw, of NH4 (median = 86 m) and PO4 (median = 96 m) were significantly different (α = 0.05) than NO3 (median = 236 m). Areal uptake rates of NH4 (median = 28 μg m-2 min-1) were significantly different than NO3 and PO4 (median = 15 and 14 μg m-2 min-1, respectively). There were significant differences among NH4, NO3, and PO4 uptake velocity (median = 5, 1, and 2 mm min-1, respectively). Correlation analysis results were equivocal on the effect of transient storage on nutrient spiraling. Application of these data to a stream network model showed that recycling (defined here as stream length ÷ Sw) of NH4 and NO3 generally increased with stream order, while PO4 recycling remained constant along a first- to fifth-order stream gradient. Within this hypothetical stream network, cumulative NH4 uptake decreased slightly with stream order, while cumulative NO3 and PO4 uptake increased with stream order. These data suggest the importance of larger rivers to nutrient spiraling and the need to consider how stream networks affect nutrient flux between terrestrial and marine ecosystems.

  18. GANIL-SPIRAL2: A new era

    Science.gov (United States)

    Gales, Sydney

    2011-05-01

    GANIL presently offers unique opportunities in nuclear physics and many other fields that arise from not only the provision of low-energy stable beams, fragmentation beams and re-accelerated radioactive species, but also from the availability of a wide range of state-of-the-art spectrometers and instrumentation. A few examples of recent highlights are discussed in the present paper. With the construction of SPIRAL2 over the next few years, GANIL is in a good position to retain its world-leading capability. As selected by the ESFRI committee, the next generation of ISOL facility in Europe is represented by the SPIRAL2 project to be built at GANIL (Caen, France). SPIRAL 2 is based on a high power, CW, superconducting LINAC, delivering 5 mA of deuteron beams at 40 MeV (200 KW) directed on a C converter+ Uranium target and producing therefore more than 1013 fissions/s. The expected radioactive beam intensities in the mass range from A = 60 to A = 140, will surpass by two orders of magnitude any existing facilities in the world. These unstable atoms will be available at energies between few KeV/n to 15 MeV/n. The same driver will accelerate high intensity (100 μA to 1 mA), heavier ions (Ar up to Xe) at maximum energy of 14 MeV/n. Under the 7FP program of European Union called *Preparatory phase*, the SPIRAL2 project has been granted a budget of about 4M€ to build up an international consortium around this new venture. The status of the construction of SPIRAL2 accelerator and associated physics instruments in collaboration with EU and International partners will be presented.

  19. Design of spiral fin type condenser for hydrogen cryogenic distillation column

    International Nuclear Information System (INIS)

    Iwai, Yasunori; Nishi, Masataka; Yamanishi, Toshihiko

    2005-08-01

    The purpose of this paper is the proposal of new concept condenser for hydrogen cryogenic distillation column of Hydrogen Isotope Separation System (ISS) in a fusion reactor, and the establishment of numerical evaluation method of the hydrogen isotope inventory in the condenser. A large amount of hydrogen isotopes including high concentration of tritium, radioactive hydrogen isotope, has been handled in the cryogenic distillation column. Therefore, from the safety point of view, cryogenic coolant tube was commonly arranged to surround the condensed area to prevent the mixing of tritium into the coolant. This inevitable arrangement leads the difficulty in the minimization of the condenser. The scale of condenser has influence on the scale of the ISS and its earthquake-resistance. The spiral fin type condenser, which introduces fins inside it and in coolant tube to enhance heat exchange, is proposed as a new concept condenser for hydrogen cryogenic distillation column to miniaturize the condenser. The volume of spiral fin type condenser is estimated to become less than half of that of coil tube type condenser currently in use. Accordingly, it is found that the adoption of spiral fin type condenser realizes the significant miniaturization of the ISS. Moreover, the numerical evaluation method of the hydrogen isotope inventory in the condenser is proposed. The validity of this method was confirmed by the experimental data. The synthetic design of the condenser for the hydrogen cryogenic distillation column is achieved by the combination of the proposed new concept condenser with the numerical evaluation method of the hydrogen isotope inventory. (author)

  20. Tracheostomy tube - eating

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000464.htm Tracheostomy tube - eating To use the sharing features on ... when you swallow foods or liquids. Eating and Tracheostomy Tubes When you get your tracheostomy tube, or ...

  1. Eustachian tube patency

    Science.gov (United States)

    Eustachian tube patency refers to how much the eustachian tube is open. The eustachian tube runs between the middle ear and the throat. It controls the pressure behind the eardrum and middle ear space. This helps keep ...

  2. Spiral analysis-improved clinical utility with center detection.

    Science.gov (United States)

    Wang, Hongzhi; Yu, Qiping; Kurtis, Mónica M; Floyd, Alicia G; Smith, Whitney A; Pullman, Seth L

    2008-06-30

    Spiral analysis is a computerized method that measures human motor performance from handwritten Archimedean spirals. It quantifies normal motor activity, and detects early disease as well as dysfunction in patients with movement disorders. The clinical utility of spiral analysis is based on kinematic and dynamic indices derived from the original spiral trace, which must be detected and transformed into mathematical expressions with great precision. Accurately determining the center of the spiral and reducing spurious low frequency noise caused by center selection error is important to the analysis. Handwritten spirals do not all start at the same point, even when marked on paper, and drawing artifacts are not easily filtered without distortion of the spiral data and corruption of the performance indices. In this report, we describe a method for detecting the optimal spiral center and reducing the unwanted drawing artifacts. To demonstrate overall improvement to spiral analysis, we study the impact of the optimal spiral center detection in different frequency domains separately and find that it notably improves the clinical spiral measurement accuracy in low frequency domains.

  3. Heat exchanger tube mounts

    Science.gov (United States)

    Wolowodiuk, W.; Anelli, J.; Dawson, B.E.

    1974-01-01

    A heat exchanger in which tubes are secured to a tube sheet by internal bore welding is described. The tubes may be moved into place in preparation for welding with comparatively little trouble. A number of segmented tube support plates are provided which allow a considerable portion of each of the tubes to be moved laterally after the end thereof has been positioned in preparation for internal bore welding to the tube sheet. (auth)

  4. Effect of Processing on Physiochemical Properties and Fatty Acid Composition of Fluted Pumpkin (Telfairia occidentails) Seed Oil

    International Nuclear Information System (INIS)

    Alademeyin, J. O.; Arawande, J. O.

    2016-01-01

    This paper reports the physicochemical properties and fatty acid composition of the seed oil extracted from fluted pumpkin (Telfairia occidentalis). The extracted oil was degummed, neutralised and bleached. The oil yield was 42.26±0.20%. The specific gravity (at 25 degree C) of the oil was 0.923±0.003 and the refractive index (at 25 degree C) was 1.475±0.002. Processing of the crude oil resulted in progressive decrease in turbidity, colour, free fatty acid, acid value, peroxide value and saponification value. However, there was increase in smoke point (243.00±0.03 to 253.00±0.03 degree C), flash point (285.00±1.20 to 304.0 1.10 degree C) and fire point (345.001.10 to 358.0 1.55 degree C) as well as iodine value (113.00 to 121.50 g/100 g) and fatty acid composition during the processing of the oil. The fatty acids detected in the oil samples were myristic, palmitic, stearic, oleic, arachidic, behenic, linoleic and linolenic acids. The predominant fatty acid was oleic acid (47.40-47.90%) followed by linoleic acid (26.36-30.44%) while the least fatty acid was linolenic acid (0.01-0.05%). (author)

  5. Tube holding system

    International Nuclear Information System (INIS)

    Cunningham, R.C.

    1978-01-01

    A tube holding rig is described for the lateral support of tubes arranged in tight parcels in a heat exchanger. This tube holding rig includes not less than two tube supporting assemblies, with a space between them, located crosswise with respect to the tubes, each supporting assembly comprising a first set of parallel components in contact with the tubes, whilst a second set of components is also in contact with the tubes. These two sets of parts together define apertures through which the tubes pass [fr

  6. Attenuation of low frequency duct noise by a flute-like silencer

    Science.gov (United States)

    Huang, Lixi

    2009-09-01

    A broadband, duct noise reflection mechanism is introduced in this theoretical study. It consists of side-branch cavities filled with a light gas, e.g. helium, and covered by impervious, tensioned membranes as two apertures, one at the inlet and another at the exit. Incident waves are scattered by the membranes into two passages, one through the central duct and another through the cavity bypass. Due to the faster speed of sound in the bypass, a Herschel-Quincke tube resonance appears and gives a peak in the transmission loss spectrum. Another resonance occurs when the frequency of the incident sound coincides with the vibroacoustic frequency determined by the membrane tension and inertia contributions from the membrane and the fluid media. With appropriate tensile stress, the trough between the two spectral peaks can be elevated to a desirable high level, e.g. 10 dB, and the crucial factor is identified as the low density of the cavity gas filling. The broadband sound reflection performance is comparable with and even exceeds that of the drum-like silencer [L. Huang, Parametric study of a drum-like silencer, Journal of Sound and Vibration 269 (2004) 467-488] with the same cavity geometry, but the current mechanism requires a low tensile stress which is much easier to implement in practice.

  7. Fast spiral-scan atomic force microscopy

    International Nuclear Information System (INIS)

    Mahmood, I A; Reza Moheimani, S O

    2009-01-01

    In this paper, we describe a new scanning technique for fast atomic force microscopy. In this method, the sample is scanned in a spiral pattern instead of the well established raster pattern. A spiral scan can be produced by applying single frequency cosine and sine signals with slowly varying amplitudes to the x-axis and y-axis of an atomic force microscope (AFM) scanner respectively. The use of the single tone input signals allows the scanner to move at high speeds without exciting the mechanical resonance of the device and with relatively small control efforts. Experimental results obtained by implementing this technique on a commercial AFM indicate that high-quality images can be generated at scan frequencies well beyond the raster scans.

  8. Spiral optical designs for nonimaging applications

    Science.gov (United States)

    Zamora, Pablo; Benítez, Pablo; Miñano, Juan C.; Vilaplana, Juan; Buljan, Marina

    2011-10-01

    Manufacturing technologies as injection molding or embossing specify their production limits for minimum radii of the vertices or draft angle for demolding, for instance. In some demanding nonimaging applications, these restrictions may limit the system optical efficiency or affect the generation of undesired artifacts on the illumination pattern. A novel manufacturing concept is presented here, in which the optical surfaces are not obtained from the usual revolution symmetry with respect to a central axis (z axis), but they are calculated as free-form surfaces describing a spiral trajectory around z axis. The main advantage of this new concept lies in the manufacturing process: a molded piece can be easily separated from its mold just by applying a combination of rotational movement around axis z and linear movement along axis z, even for negative draft angles. Some of these spiral symmetry examples will be shown here, as well as their simulated results.

  9. Star distribution in the Orion spiral arm

    International Nuclear Information System (INIS)

    Basharina, T.S.; Pavlovskaya, E.D.; Filippova, A.A.

    1985-01-01

    The structure of the Orion spiral arm is studied by numerical experiments, assuming that in each direction considered the star distribution along the line of sight is a combination of two Gaussian laws. The corresponding parameters are evaluated for four Milky Way fields; the bimodal laws now fit the observations by the chi 2 criterion. In the Orion arm the line-of-sight star densities follow asymmetric curves, steeper at the outer edge of the arm

  10. Dark and visible matter in spiral galaxies

    International Nuclear Information System (INIS)

    Persic, M.; Salucci, P.; Durham Univ.

    1988-01-01

    Exploiting relevant information from the profiles of rotation curves, we calculate the dark-to-luminous mass ratio within the disc size for a sample of 43 spiral galaxies. The values we find, while proving the ubiquitous presence of dark matter, vary with luminosity. Faint and bright galaxies are found to be respectively halo- and disc-dominated in the disc regions. The luminosity sequence turns out to be a dark-to-luminous sequence. (author)

  11. The surface brightness of spiral galaxies

    International Nuclear Information System (INIS)

    Phillipps, S.; Disney, M.

    1983-01-01

    It is proposed that Freeman's discovery that the extrapolated central surface brightness of spiral galaxies is approximately constant can be simply explained if the galaxies contain a spheroidal component which dominates the light in their outer isophotes. Calculations of an effective central surface brightness indicate a wide spread of values. This requires either a wide spread in disc properties or significant spheroidal components or, most probably, both. (author)

  12. Spiral-arm instability: giant clump formation via fragmentation of a galactic spiral arm

    Science.gov (United States)

    Inoue, Shigeki; Yoshida, Naoki

    2018-03-01

    Fragmentation of a spiral arm is thought to drive the formation of giant clumps in galaxies. Using linear perturbation analysis for self-gravitating spiral arms, we derive an instability parameter and define the conditions for clump formation. We extend our analysis to multicomponent systems that consist of gas and stars in an external potential. We then perform numerical simulations of isolated disc galaxies with isothermal gas, and compare the results with the prediction of our analytic model. Our model describes accurately the evolution of the spiral arms in our simulations, even when spiral arms dynamically interact with one another. We show that most of the giant clumps formed in the simulated disc galaxies satisfy the instability condition. The clump masses predicted by our model are in agreement with the simulation results, but the growth time-scale of unstable perturbations is overestimated by a factor of a few. We also apply our instability analysis to derive scaling relations of clump properties. The expected scaling relation between the clump size, velocity dispersion, and circular velocity is slightly different from that given by the Toomre instability analyses, but neither is inconsistent with currently available observations. We argue that the spiral-arm instability is a viable formation mechanism of giant clumps in gas-rich disc galaxies.

  13. Incorporating hydrologic variability into nutrient spiraling

    Science.gov (United States)

    Doyle, Martin W.

    2005-09-01

    Nutrient spiraling describes the path of a nutrient molecule within a stream ecosystem, combining the biochemical cycling processes with the downstream driving force of stream discharge. To date, nutrient spiraling approaches have been hampered by their inability to deal with fluctuating flows, as most studies have characterized nutrient retention within only a small range of discharges near base flow. Here hydrologic variability is incorporated into nutrient spiraling theory by drawing on the fluvial geomorphic concept of effective discharge. The effective discharge for nutrient retention is proposed to be that discharge which, over long periods of time, is responsible for the greatest portion of nutrient retention. A developed analytical model predicts that the effective discharge for nutrient retention will equal the modal discharge for small streams or those with little discharge variability. As modal discharge increases or discharge variability increases, the effective discharge becomes increasingly less than the modal discharge. In addition to the effective discharge, a new metric is proposed, the functionally equivalent discharge, which is the single discharge that will reproduce the magnitude of nutrient retention generated by the full hydrologic frequency distribution when all discharge takes place at that rate. The functionally equivalent discharge was found to be the same as the modal discharge at low hydrologic variability, but increasingly different from the modal discharge at large hydrologic variability. The functionally equivalent discharge provides a simple quantitative means of incorporating hydrologic variability into long-term nutrient budgets.

  14. Study on influence of three kinds of stress on crack propagation in butt welds of spiral coil waterwall for ultra supercritical boiler

    Science.gov (United States)

    Yan, Zhenrong; Si, Jun

    2017-09-01

    The spiral coil waterwall is the main pressure parts and the core functional components of Ultra Supercritical Boiler. In the process of operation, the spiral coil waterwall is under the combined action of welding residual stress, installation defects stress and working fluid stress, Cracks and crack propagation are easy to occur in butt welds with defects. In view of the early cracks in the butt welds of more T23 water cooled walls, in this paper, the influence of various stresses on the crack propagation in the butt welds of spiral coil waterwall was studied by numerical simulation. Firstly, the welding process of T23 water cooled wall tube was simulated, and the welding residual stress field was obtained. Then,on the basis, put the working medium load on the spiral coil waterwall, the supercoated stress distribution of the welding residual stress and the stress of the working medium is obtained. Considering the bending moment formed by stagger joint which is the most common installation defects, the stress field distribution of butt welds in T23 water-cooled wall tubes was obtained by applying bending moment on the basis of the stress field of the welding residual stress and the working medium stress. The results show that, the welding residual stress is small, the effect of T23 heat treatment after welding to improve the weld quality is not obvious; The working medium load plays a great role in the hoop stress of the water cooled wall tube, and promotes the cracks in the butt welds; The axial stress on the water cooled wall tube produced by the installation defect stress is obvious, the stagger joint, and other installation defects are the main reason of crack propagation of spiral coil waterwall. It is recommended that the control the bending moment resulting from the stagger joint not exceed 756.5 NM.

  15. Ablation acceleration of macroparticle in spiral magnetic fields

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1981-05-01

    The rocket motion of macroparticles heated by energetic pulses in a spiral magnetic field was studied. The purpose of the present work is to study the ablation acceleration of a macroparticle in a spiral magnetic field with the help of the law of conservation of angular momentum. The basic equation of motion of ablatively accelerated projectile in a spiral magnetic field was derived. Any rocket which is ejecting fully ionized plasma in an intense magnetic field with rotational transform is able to have spin by the law of conservation of momentum. The effect of spiral magnetic field on macroparticle acceleration is discussed. The necessary mass ratio increase exponentially with respect to the field parameter. The spiral field should be employed with care to have only to stabilize the position of macroparticles. As conclusion, it can be said that the ablation acceleration of the projectile in a spiral field can give the accelerated body spin quite easily. (Kato, T.)

  16. Mechanical response of spiral interconnect arrays for highly stretchable electronics

    KAUST Repository

    Qaiser, Nadeem

    2017-11-21

    A spiral interconnect array is a commonly used architecture for stretchable electronics, which accommodates large deformations during stretching. Here, we show the effect of different geometrical morphologies on the deformation behavior of the spiral island network. We use numerical modeling to calculate the stresses and strains in the spiral interconnects under the prescribed displacement of 1000 μm. Our result shows that spiral arm elongation depends on the angular position of that particular spiral in the array. We also introduce the concept of a unit-cell, which fairly replicates the deformation mechanism for full complex hexagon, diamond, and square shaped arrays. The spiral interconnects which are axially connected between displaced and fixed islands attain higher stretchability and thus experience the maximum deformations. We perform tensile testing of 3D printed replica and find that experimental observations corroborate with theoretical study.

  17. Wave-particle dualism of spiral waves dynamics.

    Science.gov (United States)

    Biktasheva, I V; Biktashev, V N

    2003-02-01

    We demonstrate and explain a wave-particle dualism of such classical macroscopic phenomena as spiral waves in active media. That means although spiral waves appear as nonlocal processes involving the whole medium, they respond to small perturbations as effectively localized entities. The dualism appears as an emergent property of a nonlinear field and is mathematically expressed in terms of the spiral waves response functions, which are essentially nonzero only in the vicinity of the spiral wave core. Knowledge of the response functions allows quantitatively accurate prediction of the spiral wave drift due to small perturbations of any nature, which makes them as fundamental characteristics for spiral waves as mass is for the condensed matter.

  18. COMPLIANCE OF KÖHLER OP:33 NO I-II-III ETUDE BOOKS THAT ARE USED IN HIGH SCHOOLS OF FINE ARTS WITH FLUTE CONCERTOS

    Directory of Open Access Journals (Sweden)

    Yucan EKE

    2015-09-01

    Full Text Available This research is done for attesting the compliance of the etudes in German composer Ernesto Köhler’s op:33 no I-II-III books that are used in high schools of fine arts, with ability to play the flute concertos in high schools of fine arts 12 grade program, in terms of the knowledge – skills and musical functions they cover and also for contributing to learning by matching the etudes and works which are relevant. Etudes and the chosen concertos are analyzed and separated into templates in terms of melody, rhythm and tone for this research. Opinions are taken from the flute lesson instructors of various universities of Turkey to define the melody, technique and rhythm patterns. As a result of the analysis, Köhler op: 33, Book I, Etudes: 2,3,6,7,8,9,10,11,12; Köhler op: 33, Book II, Etudes:1,3,4,5,8,9,10,11; Köhler op: 33, Book III, Etudes: 1, 2, 4, 5, 6, 8; It is determined that the etudes given above in Köhler books are qualified enough to be preparative and instructive for the ability of playing the flute concertos. Some suggestions are given about which etude(s is instructive for which concerto and what kind of benefits could be gained, by this study. Based on the observed results, various suggestions are made about defining and studying the etudes which meet the technical, rhythmic and melodic features of the target concerto.

  19. Nonlinear dynamics of breathers in the spiral structures of magnets

    Energy Technology Data Exchange (ETDEWEB)

    Kiselev, V. V., E-mail: kiselev@imp.uran.ru; Raskovalov, A. A. [Russian Academy of Sciences, Mikheev Institute of Metal Physics, Ural Branch (Russian Federation)

    2016-06-15

    The structure and properties of pulsating solitons (breathers) in the spiral structures of magnets are analyzed within the sine-Gordon model. The breather core pulsations are shown to be accompanied by local shifts and oscillations of the spiral structure with the formation of “precursors” and “tails” in the moving soliton. The possibilities for the observation and excitation of breathers in the spiral structures of magnets and multiferroics are discussed.

  20. Cochlea and other spiral forms in nature and art.

    Science.gov (United States)

    Marinković, Slobodan; Stanković, Predrag; Štrbac, Mile; Tomić, Irina; Ćetković, Mila

    2012-01-01

    The original appearance of the cochlea and the specific shape of a spiral are interesting for both the scientists and artists. Yet, a correlation between the cochlea and the spiral forms in nature and art has been very rarely mentioned. The aim of this study was to investigate the possible correlation between the cochlea and the other spiral objects in nature, as well as the artistic presentation of the spiral forms. We explored data related to many natural objects and examined 13,625 artworks created by 2049 artists. We also dissected 2 human cochleas and prepared histologic slices of a rat cochlea. The cochlea is a spiral, cone-shaped osseous structure that resembles certain other spiral forms in nature. It was noticed that parts of some plants are arranged in a spiral manner, often according to Fibonacci numbers. Certain animals, their parts, or their products also represent various types of spirals. Many of them, including the cochlea, belong to the logarithmic type. Nature created spiral forms in the living world to pack a larger number of structures in a limited space and also to improve their function. Because the cochlea and other spiral forms have a certain aesthetic value, many artists presented them in their works of art. There is a mathematical and geometric correlation between the cochlea and natural spiral objects, and the same functional reason for their formation. The artists' imagery added a new aspect to those domains. Obviously, the creativity of nature and Homo sapiens has no limits--like the infinite distal part of the spiral. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. SPIRAL2 Week 2012 - Slides of the presentations

    International Nuclear Information System (INIS)

    Staley, F.; Jacquemet, M.; Lewitowicz, M.; Bertrand, P.; Tuske, O.; Caruso, A.; Leyge, J.F.; Perrot, L.; Di Giacomo, M.; Ausset, P.; Moscatello, M.H.; Savalle, A.; Rannou, B.; Lambert, M.; Petit, E.; Hulin, X.; Barre-Boscher, N.; Tusseau-Nenez, S.; Tecchio, L.B.

    2013-01-01

    The main goal of the 5. edition of the SPIRAL2 Week is to present and discuss the current status of the SPIRAL2 project in front of a large community of scientists and engineers. The program of the meeting will include presentations on scientific and technical developments related to the baseline project, experiments and theory. The main topics to be discussed at the conference are: -) physics and detectors at SPIRAL2, -) driver accelerators, -) production of radioactive ion beams (RIB), -) safety, -) buildings and infrastructure, -) RIB facilities worldwide, and -) SPIRAL2 preparatory phase. This document is made up of the slides of the presentations

  2. Algorithms for computing efficient, electric-propulsion, spiralling trajectories

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop techniques for rapidly designing many-revolution, electric-propulsion, spiralling trajectories, including the effects of shadowing, gravity harmonics, and...

  3. Self-regulated model of galactic spiral structure formation.

    Science.gov (United States)

    Cartin, Daniel; Khanna, Gaurav

    2002-01-01

    The presence of spiral structure in isolated galaxies is a problem that has only been partially explained by theoretical models. Because the rate and pattern of star formation in the disk must depend only on mechanisms internal to the disk, we may think of the spiral galaxy as a self-regulated system far from equilibrium. This paper uses this idea to look at a reaction-diffusion model for the formation of spiral structures in certain types of galaxies. In numerical runs of the model, spiral structure forms and persists over several revolutions of the disk, but eventually dies out.

  4. Spread of the spiraling white fly Aleurodicus dispersus (Homoptera ...

    African Journals Online (AJOL)

    Spread of the spiraling white fly Aleurodicus dispersus (Homoptera: Aleyrodidae) and its parasitoids Encarcia species (Hymenoptera: Aphelinidae) on horticultural plants in Northwest and Central Nigeria.

  5. Topological Signatures in the Electronic Structure of Graphene Spirals

    DEFF Research Database (Denmark)

    Avdoshenko, Stas.M.; Koskinen, Pekka; Sevincli, Haldun

    2013-01-01

    and graphene systems. Here, we introduce topologically distinct graphene forms - graphene spirals - and employ density-functional theory to investigate their geometric and electronic properties. We found that the spiral topology gives rise to an intrinsic Rashba spin-orbit splitting. Through a Hamiltonian...... constrained by space curvature, graphene spirals have topologically protected states due to time-reversal symmetry. In addition, we argue that the synthesis of such graphene spirals is feasible and can be achieved through advanced bottom-up experimental routes that we indicate in this work....

  6. Virtual bronchoscopy based on spiral CT images

    Science.gov (United States)

    Englmeier, Karl-Hans; Haubner, Michael; Krapichler, Christian; Schuhmann, Dietrich; Seemann, Mark; Fuerst, H.; Reiser, Maximilian

    1998-06-01

    Purpose: To improve the diagnosis of pathologic modified airways, a visualization system has been developed and tested based on the techniques of digital image analysis, synthesis of spiral CT and the visualization by methods of virtual reality. Materials and Methods: 20 patients with pathologic modifications of the airways (tumors, obstructions) were examined with Spiral-CT. The three-dimensional shape of the airways and the lung tissue is defined by a semiautomatic volume growing method and a following geometric surface reconstruction. This is the basis of a multidimensional display system which visualizes volumes, surfaces and computation results simultaneously. To enable the intuitive and immersive inspection of the airways a virtual reality system, consisting of two graphic engines, a head mounted display system, data gloves and specialized software was integrated. Results: In 20 cases the extension of the pathologic modification of the airways could be visualized with the virtual bronchoscopy. The user interacts with and manipulates the 3D model of the airways in an intuitive and immersive way. In contrast to previously proposed virtual bronchoscopy systems the described method permits truly interactive navigation and detailed exploration of anatomic structures. The system enables a user oriented and fast inspection of the volumetric image data. Conclusion: To support radiological diagnosis with additional information in an easy to use and fast way a virtual bronchoscopy system was developed. It enables the immersive and intuitive interaction with 3D Spiral CTs by truly 3D navigation within the airway system. The complex anatomy of the central tracheobronchial system could be clearly visualized. Peripheral bronchi are displayed up to 5th degree.

  7. Production and post acceleration scheme for spiral

    International Nuclear Information System (INIS)

    Bibet, D.

    2001-01-01

    SPIRAL, the R.I.B. facility of GANIL uses heavy ion beams to produce radioactive atoms inside a thick target. Atoms are ionised in a compact permanent magnet ECR ion source. The compact cyclotron CIME accelerates the radioactive ions in an energy range from 1.7 to 25 MeV/u. The cyclotron acts as a mass separator with resolving power of 2500. Plastic scintillator and silicon detectors are used to tune the machine at a very low intensity. An overview of the facility, stable beam tests results and the R and D program will be presented. (authors)

  8. Controls and automation in the SPIRAL project

    International Nuclear Information System (INIS)

    Bothner, U.; Boulot, A.; Maherault, J.; Martial, L.

    1999-01-01

    The control and automation team of the R and D of Accelerator-Exotic Beam Department has had in the framework of SPIRAL collaboration the following tasks: 1. automation of the resonator high frequency equipment of the CIME cyclotron; 2. automation of the vacuum equipment, i.e. the low energy line (TBE), the CIME cyclotron, the low energy line (BE); 3. automation of load safety for power supply; 4. for each of these tasks a circuitry file based on the SCHEMA software has been worked out. The programs required in the automation of load safety for power supply (STEP5, PROTOOL, DESIGNER 4.1) were developed and implemented for PC

  9. Galaxy Zoo: dust in spiral galaxies star

    OpenAIRE

    Masters, Karen L.; Nichol, Robert; Bamford, Steven; Mosleh, Moein; Lintott, Chris J.; Andreescu, Dan; Edmondson, Edward M.; Keel, William C.; Murray, Phil; Raddick, M. Jordan; Schawinski, Kevin; Slosar, Anze; Szalay, Alexander S.; Thomas, Daniel; Vandenberg, Jan

    2010-01-01

    We investigate the effect of dust on spiral galaxies by measuring the inclination dependence of optical colours for 24 276 well-resolved Sloan Digital Sky Survey (SDSS) galaxies visually classified via the Galaxy Zoo project. We find clear trends of reddening with inclination which imply a total extinction from face-on to edge-on of 0.7, 0.6, 0.5 and 0.4 mag for the ugri passbands (estimating 0.3 mag of extinction in z band). We split the sample into ‘bulgy’ (early-type) and ‘discy’ (late-typ...

  10. Inner surface modification of a tube by magnetic glow-arc plasma source ion implantation

    International Nuclear Information System (INIS)

    Zhang Guling; Chinese Academy of Sciences, Beijing; Wang Jiuli; Feng Wenran; Chen Guangliang; Gu Weichao; Niu Erwu; Fan Songhua; Liu Chizi; Yang Size; Wu Xingfang

    2006-01-01

    A new method named the magnetic glow-arc plasma source ion implantation (MGA-PSII) is proposed for inner surface modification of tubes. In MGA-PSII, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride (TiN) films are prepared on the inner surface of a stainless steel tube in diameter 90 mm and length 600 mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved. (authors)

  11. Inner Surface Modification of a Tube by Magnetic Glow-Arc Plasma Source Ion Implantation

    Science.gov (United States)

    Zhang, Gu-Ling; Wang, Jiu-Li; Wu, Xing-Fang; Feng, Wen-Ran; Chen, Guang-Liang; Gu, Wei-Chao; Niu, Er-Wu; Fan, Song-Hua; Liu, Chi-Zi; Yang, Si-Ze

    2006-05-01

    A new method named the magnetic glow-arc plasma source ion implantation (MGA-PSII) is proposed for inner surface modification of tubes. In MGA-PSII, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride (TiN) films are prepared on the inner surface of a stainless steel tube in diameter 90 mm and length 600 mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved.

  12. 2D array based on fermat spiral

    Science.gov (United States)

    Martínez, O.; Martín, C. J.; Godoy, G.; Ullate, L. G.

    2010-01-01

    The main challenge faced by 3D ultrasonic imaging with 2D array transducer is the large number of elements required to achieve an acceptable level of quality in the images. Therefore, the optimization of the array layout to reduce the number of active elements in the aperture has been a research topic in the last years. Nowadays, CMUT array technology has made viable the production of 2D arrays with larger flexibility on elements size, shape and position. This is opening new options in 2D array design, allowing to revise as viable alternatives others layouts that had been studied in the past, like circular and Archimedes spiral layout. In this work the problem of designing an imaging system array with a diameter of 60 λ and a limited number of elements using the Fermat spiral layout has been studied. This study has been done for two different numbers of electronic channels (N = 128 and N = 256). As summary, a general discussion of the results and the most interesting cases are presented.

  13. Spiral-shaped reactor for water disinfection

    KAUST Repository

    Soukane, Sofiane

    2016-04-20

    Chlorine-based processes are still widely used for water disinfection. The disinfection process for municipal water consumption is usually carried out in large tanks, specifically designed to verify several hydraulic and disinfection criteria. The hydrodynamic behavior of contact tanks of different shapes, each with an approximate total volume of 50,000 m3, was analyzed by solving turbulent momentum transport equations with a computational fluid dynamics code, namely ANSYS fluent. Numerical experiments of a tracer pulse were performed for each design to generate flow through curves and investigate species residence time distribution for different inlet flow rates, ranging from 3 to 12 m3 s−1. A new nature-inspired Conch tank design whose shape follows an Archimedean spiral was then developed. The spiral design is shown to strongly outperform the other tanks’ designs for all the selected plug flow criteria with an enhancement in efficiency, less short circuiting, and an order of magnitude improvement in mixing and dispersion. Moreover, following the intensification philosophy, after 50% reduction in its size, the new design retains its properties and still gives far better results than the classical shapes.

  14. Tracheostomy tube - speaking

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000465.htm Tracheostomy tube - speaking To use the sharing features on ... are even speaking devices that can help you. Tracheostomy Tubes and Speaking Air passing through vocal cords ( ...

  15. X-ray tubes

    International Nuclear Information System (INIS)

    Young, R.W.

    1979-01-01

    A form of x-ray tube is described which provides satisfactory focussing of the electron beam when the beam extends for several feet from gun to target. Such a tube can be used for computerised tomographic scanning. (UK)

  16. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  17. Jejunostomy feeding tube

    Science.gov (United States)

    ... may replace the tube every now and then. Cleaning the Skin Around the J-tube To clean ... this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial ...

  18. Determination and evaluation of effective criteria to location selection the optimal for establishing fluting paper mills from agricultural residues of Mazandaran province

    Directory of Open Access Journals (Sweden)

    Abdollah barimani

    2013-11-01

    Full Text Available Location selection for factory competitiveness in the market place plays an important role and should be chosen so that will leads achievement of the strategic advantages compared with other competitors. The objective of this study was determination of the effective criteria for decision making to select the most suitable location for establishing a fluting paper mills from agricultural residues. For this purpose, effective criteria were divided into five major groups: Material and Product, Facilities and limitations of regional (infrastructure, Technical and Human, Economical, Rules & Regulations as well as 33 sub-criteria, after preliminary investigation, preparatory observation, and an interview with some of the paper producers and relevant experts. A hierarchy was designed based on five major groups of criteria and then the priority rates of obtained criteria and sub-criteria were determined by Analytical Hierarchy Process (AHP after compiling expert's opinions via questionnaire. Results have shown that among 33 determined effective criteria in location selection of fluting paper mills from agricultural residues , the sub-criteria of Supply residual amount, Ensure the supply of residual, Cost purchasing of raw material, Cost of transporting raw material have the highest priorities, respectively

  19. Effect of imaging parameters of spiral CT scanning on image quality for the dental implants. Visual evaluation using a semi-anthropomorphic mandible phantom

    International Nuclear Information System (INIS)

    Morita, Yasuhiko; Indou, Hiroko; Honda Eiichi

    2002-01-01

    The purpose of this study was to evaluate the effect of parameters of spiral CT scanning on the image quality required for the planning of dental implants operations. A semi-anthropomorphic mandible phantom which has artificial mandibular canals and teeth roots was used as a standard object for imaging. Spiral CT scans for the phantom settled in water phantom with diameters of 20 and 16 cm were performed. Visibility of the artificial mandibular canal made of a Teflon tube and gaps between tooth apex and canal in the mandibular phantom was evaluated for various combinations of the slice thickness, tables speeds, angles to the canal, and x-ray tube currents. Teeth roots were made of PVC (poly vinyl chloride). The artificial mandibular canal was clearly observed on the images of 1 mm slice thickness. At the same table speed of 2 mm /rotation, the images of thin slice (1 mm) were superior to that of thick slice (2 mm). The gap between teeth apex and canal was erroneously diagnosed on the images with table speeds of 3 mm/rotation. Horizontal scanning in parallel to the canal result in poor image quality for observation of mandibular canals because of the partial volume effect. A relatively high x-ray tube current (125 mA) at thin slice (1 mm) scanning was required for scanning the mandibular phantom in 20 cm water vessel. Spiral scanning with slice thickness of 1 mm and table speeds of 1 of 2 mm/rotation seemed to be suitable for dental implants. The result of this study suggested that diagnosis from two independent spiral scans with a different angle to the object was more accurate and more efficient than single spiral scanning. (author)

  20. A phenomenological theory for polarization flop in spiral multiferroic ...

    Indian Academy of Sciences (India)

    driven polarization flop in TbMnO3. The Néel wall-like magnetic structure in spiral multiferroics induces a space-dependent internal magnetic field which exerts a torque on spins to rotate bc-spiral to abspiral. The external magnetic field is argued ...

  1. A phenomenological theory for polarization flop in spiral multiferroic ...

    Indian Academy of Sciences (India)

    a space-dependent internal magnetic field which exerts a torque on spins to rotate bc-spiral to ab- spiral. The external ... Fv; 75.85.+t. Electric control of magnetization and magnetic control of polarization have been long ... divergence of magnetization, an internal field is induced which has important physical. Figure 1. ab ...

  2. On galaxy spiral arms' nature as revealed by rotation frequencies

    NARCIS (Netherlands)

    Roca-Fabrega, Santi; Valenzuela, Octavio; Figueras, Francesca; Romero-Gomez, Merce; Velazquez, Hector; Antoja Castelltort, Teresa; Pichardo, Barbara

    2013-01-01

    High-resolution N-body simulations using different codes and initial condition techniques reveal two different behaviours for the rotation frequency of transient spiral arms like structures. Whereas unbarred discs present spiral arms nearly corotating with disc particles, strong barred models

  3. Star formation and the surface brightness of spiral galaxies

    International Nuclear Information System (INIS)

    Phillipps, S.; Disney, M.

    1985-01-01

    The (blue) surface brightness of spiral galaxies is significantly correlated with their Hα linewidth. This can be most plausibly interpreted as a correlation of surface brightness with star formation rate. There is also a significant difference in surface brightness between galaxies forming stars in a grand design spiral pattern and those with floc star formation regions. (author)

  4. Up the Down Spiral with English: Guidelines, Project Insight.

    Science.gov (United States)

    Catholic Board of Education, Diocese of Cleveland, OH.

    This curriculum guide presents the philosophy, objectives, and processes which unify a student-centered English program based on Jerome Bruner's concept of the spiral curriculum. To illustrate the spiraling of the learning process (i.e., engagement, perception, interpretation, evaluation, and personal integration), the theme of "hero" is traced…

  5. The cold interstellar medium - An HI view of spiral galaxies

    NARCIS (Netherlands)

    Sancisi, R; Bender, R; Davies, RL

    1996-01-01

    An HI view of spiral galaxies is presented. In the first part the standard picture of isolated, normal spiral galaxies is briefly reviewed. In the second part attention is drawn to all those phenomena, such as tidal interactions, accretion and mergers, that depend on the galaxy environment and seem

  6. Nasogastric and feeding tubes.

    Science.gov (United States)

    Gharib, Ahmed M; Stern, Eric J; Sherbin, Vandy L; Rohrmann, Charles A

    1996-05-01

    Preview The authors' experience in a radiology department suggested to them that there is a wide range of beliefs among practitioners regarding proper placement of nasogastric and feeding tubes. Improper positioning can cause serious problems, as they explain. Indications for different tube positions, complications of incorrect tube placement, and directions for proper positioning are discussed and illustrated.

  7. Topographic Beta Spiral and Onshore Intrusion of the Kuroshio Current

    Science.gov (United States)

    Yang, De-Zhou; Huang, Rui Xin; Yin, Bao-shu; Feng, Xing-Ru; Chen, Hai-ying; Qi, Ji-Feng; Xu, Ling-jing; Shi, Yun-long; Cui, Xuan; Gao, Guan-Dong; Benthuysen, Jessica A.

    2018-01-01

    The Kuroshio intrusion plays a vitally important role in carrying nutrients to marginal seas. However, the key mechanism leading to the Kuroshio intrusion remains unclear. In this study we postulate a mechanism: when the Kuroshio runs onto steep topography northeast of Taiwan, the strong inertia gives rise to upwelling over topography, leading to a left-hand spiral in the stratified ocean. This is called the topographic beta spiral, which is a major player regulating the Kuroshio intrusion; this spiral can be inferred from hydrographic surveys. In the world oceans, the topographic beta spirals can be induced by upwelling generated by strong currents running onto steep topography. This is a vital mechanism regulating onshore intruding flow and the cross-shelf transport of energy and nutrients from the Kuroshio Current to the East China Sea. This topographic beta spiral reveals a long-term missing link between the oceanic general circulation theory and shelf dynamic theory.

  8. Spatial and mass distributions of molecular clouds and spiral structure

    International Nuclear Information System (INIS)

    Kwan, J.; Valdes, F.; National Optical Astronomy Observatories, Tucson, AZ)

    1987-01-01

    The growth of molecular clouds resulting from cloud-cloud collisions and coalescence in the Galactic ring between 4 and 8 kpc are modeled, taking into account the presence of a spiral potential and the mutual cloud-cloud gravitational attraction. The mean lifetime of molecular clouds is determined to be about 200 million years. The clouds are present in both spiral arm and interarm regions, but a spiral pattern in their spatial distribution is clearly discernible, with the more massive clouds showing a stronger correlation with the spiral arms. As viewed from within the Galactic disk, however, it is very difficult to ascertain that the molecular cloud distribution in longitude-velocity space has a spiral pattern. 19 references

  9. Some statistical properties of spiral galaxies along the Hubble sequence

    Science.gov (United States)

    Ma, Jun; Zhao, Jun-liang; Zhang, Fei-peng; Peng, Qiu-he

    A statistical study has been made for the variations along the Hubble sequence, os such parameters as the degree of tightness of winding of spiral arm λ, the pitch angle μ, the flatness of the disk H/ D25 and the thickness H along the Hubble sequence for 365 spiral galaxies published in A&Ap Supplement Series. The mean values of these quantities for the various Hubble types have been obtained for the first time. The results of the statistics show clearly 1) that the Hubble classification of spiral galaxies is one which has only a qualitative and statistical significance, and 2) that the dispersion relation in the density wave theory is valid for most spiral galaxies, i.e., the arms of most spiral galaxies satisfy the requirements of being tightly wound.

  10. The Effects of Spiral Taping Treatment on Low Back Pain

    Directory of Open Access Journals (Sweden)

    Hwang Jae-Ok

    2006-02-01

    Full Text Available Objective : The purpose of this study is to estimate the effects of spiral taping treatment on low back pain. Methods : 420 low back pain patients were treated with spiral taping or spiral taping plus herbal medicine, and no other treatments such as acupuncture, herbal acupuncture, and chiropractic therapy were added. We evaluated the improvement by physical examination and pain. Results : 364 patients felt no pain or inconvenience of daily life and 43 patients showed improvement of pain or symptom after 1 month of treatment. 13 patients showed same pain with before treatment. Conclusions : These results suggest spiral taping treatments contribute to the improvement of low back pain. Further study is needed for the confirmation of this effect of spiral taping treatments on low back pain.

  11. High-speed spiral imaging technique for an atomic force microscope using a linear quadratic Gaussian controller

    International Nuclear Information System (INIS)

    Habibullah, H.; Pota, H. R.; Petersen, I. R.

    2014-01-01

    This paper demonstrates a high-speed spiral imaging technique for an atomic force microscope (AFM). As an alternative to traditional raster scanning, an approach of gradient pulsing using a spiral line is implemented and spirals are generated by applying single-frequency cosine and sine waves of slowly varying amplitudes to the X and Y-axes of the AFM’s piezoelectric tube scanner (PTS). Due to these single-frequency sinusoidal input signals, the scanning process can be faster than that of conventional raster scanning. A linear quadratic Gaussian controller is designed to track the reference sinusoid and a vibration compensator is combined to damp the resonant mode of the PTS. An internal model of the reference sinusoidal signal is included in the plant model and an integrator for the system error is introduced in the proposed control scheme. As a result, the phase error between the input and output sinusoids from the X and Y-PTSs is reduced. The spirals produced have particularly narrow-band frequency measures which change slowly over time, thereby making it possible for the scanner to achieve improved tracking and continuous high-speed scanning rather than being restricted to the back and forth motion of raster scanning. As part of the post-processing of the experimental data, a fifth-order Butterworth filter is used to filter noises in the signals emanating from the position sensors and a Gaussian image filter is used to filter the images. A comparison of images scanned using the proposed controller (spiral) and the AFM PI controller (raster) shows improvement in the scanning rate using the proposed method

  12. High-speed spiral imaging technique for an atomic force microscope using a linear quadratic Gaussian controller.

    Science.gov (United States)

    Habibullah, H; Pota, H R; Petersen, I R

    2014-03-01

    This paper demonstrates a high-speed spiral imaging technique for an atomic force microscope (AFM). As an alternative to traditional raster scanning, an approach of gradient pulsing using a spiral line is implemented and spirals are generated by applying single-frequency cosine and sine waves of slowly varying amplitudes to the X and Y-axes of the AFM's piezoelectric tube scanner (PTS). Due to these single-frequency sinusoidal input signals, the scanning process can be faster than that of conventional raster scanning. A linear quadratic Gaussian controller is designed to track the reference sinusoid and a vibration compensator is combined to damp the resonant mode of the PTS. An internal model of the reference sinusoidal signal is included in the plant model and an integrator for the system error is introduced in the proposed control scheme. As a result, the phase error between the input and output sinusoids from the X and Y-PTSs is reduced. The spirals produced have particularly narrow-band frequency measures which change slowly over time, thereby making it possible for the scanner to achieve improved tracking and continuous high-speed scanning rather than being restricted to the back and forth motion of raster scanning. As part of the post-processing of the experimental data, a fifth-order Butterworth filter is used to filter noises in the signals emanating from the position sensors and a Gaussian image filter is used to filter the images. A comparison of images scanned using the proposed controller (spiral) and the AFM PI controller (raster) shows improvement in the scanning rate using the proposed method.

  13. Imaging of head and neck tumors -- methods: CT, spiral-CT, multislice-spiral-CT

    Energy Technology Data Exchange (ETDEWEB)

    Baum, Ulrich E-mail: baum@idr.med.uni-erlangen.de; Greess, Holger; Lell, Michael; Noemayr, Anton; Lenz, Martin

    2000-03-01

    Spiral-CT is standard for imaging neck tumors. In correspondence with other groups we routinely use spiral-CT with thin slices (3 mm), a pitch of 1.3-1.5 and an overlapping reconstruction increment (2-3 mm). In patients with dental fillings a short additional spiral parallel to the corpus of the mandible reduces artifacts behind the dental arches and improves the diagnostic value of CT. For the assessment of the base of the skull, the orbital floor, the palate and paranasal sinuses an additional examination in the coronal plane is helpful. Secondary coronal reconstructions of axial scans are helpful in the evaluation of the crossing of the midline by small tumors of the tongue base or palate. For an optimal vascular or tissue contrast a sufficient volume of contrast medium and a start delay greater than 70-80 s are necessary. In our opinion the best results can be achieved with a volume of 150 ml, a flow of 2.5 ml/s and a start delay of 80 s. Dynamic enhanced CT is only necessary in some special cases. There is clear indication for dynamic enhanced CT where a glomus tumor is suspected. Additional functional CT imaging during i-phonation and/or Valsalva's maneuver are of great importance to prove vocal cords mobility. Therefore, imaging during i-phonation is an elemental part of every thorough examination of the hypopharynx and larynx region. Multislice-spiral-CT allows almost isotropic imaging of the head and neck region and improves the assessment of tumor spread and lymph node metastases in arbitrary oblique planes. Thin structures (the base of the skull, the orbital floor, the hard palate) as well as the floor of the mouth can be evaluated sufficiently with multiplanar reformations. Usually, additional coronal scanning is not necessary with multislice-spiral-CT. Multislice-spiral-CT is especially advantageous in defining the critical relationships of tumor and lymph node metastases and for functional imaging of the hypopharynx and larynx not only in the

  14. Imaging of head and neck tumors -- methods: CT, spiral-CT, multislice-spiral-CT

    International Nuclear Information System (INIS)

    Baum, Ulrich; Greess, Holger; Lell, Michael; Noemayr, Anton; Lenz, Martin

    2000-01-01

    Spiral-CT is standard for imaging neck tumors. In correspondence with other groups we routinely use spiral-CT with thin slices (3 mm), a pitch of 1.3-1.5 and an overlapping reconstruction increment (2-3 mm). In patients with dental fillings a short additional spiral parallel to the corpus of the mandible reduces artifacts behind the dental arches and improves the diagnostic value of CT. For the assessment of the base of the skull, the orbital floor, the palate and paranasal sinuses an additional examination in the coronal plane is helpful. Secondary coronal reconstructions of axial scans are helpful in the evaluation of the crossing of the midline by small tumors of the tongue base or palate. For an optimal vascular or tissue contrast a sufficient volume of contrast medium and a start delay greater than 70-80 s are necessary. In our opinion the best results can be achieved with a volume of 150 ml, a flow of 2.5 ml/s and a start delay of 80 s. Dynamic enhanced CT is only necessary in some special cases. There is clear indication for dynamic enhanced CT where a glomus tumor is suspected. Additional functional CT imaging during i-phonation and/or Valsalva's maneuver are of great importance to prove vocal cords mobility. Therefore, imaging during i-phonation is an elemental part of every thorough examination of the hypopharynx and larynx region. Multislice-spiral-CT allows almost isotropic imaging of the head and neck region and improves the assessment of tumor spread and lymph node metastases in arbitrary oblique planes. Thin structures (the base of the skull, the orbital floor, the hard palate) as well as the floor of the mouth can be evaluated sufficiently with multiplanar reformations. Usually, additional coronal scanning is not necessary with multislice-spiral-CT. Multislice-spiral-CT is especially advantageous in defining the critical relationships of tumor and lymph node metastases and for functional imaging of the hypopharynx and larynx not only in the

  15. A Method to Automate Identification of Spiral Arms in Galaxies

    Science.gov (United States)

    Lacey, Christina K.; Mercer, K.

    2014-01-01

    We present our preliminary results in identifying the spiral arms of NGC 6946 using a nearest-neighbors analysis. NGC 6946 is grand design spiral galaxy with well-defined arms. The spiral arms were previously identified in an Hα image and traced out by Matonick, D. et al., ApJS, 113, 333, (1997) by visual inspection. We want to develop a computer algorithm that will identify the spiral arms automatically. Once the spiral arms have been found digitally, we can use this information to compare the spiral arms with the locations of compact objects such as supernova remnants and perform statistical tests, for example, to determine if the supernova remnants are associated with the spiral arms. We are using the publicly available program PyFITS, a development project of the Science Software Branch at the Space Telescope Science Institute (STScI) that is available for software download from STScI, to perform a computer-based image analysis. We have written python macros that interact with the already written image manipulation and display features of PyFITS to perform the image analysis and implement a nearest-neighbors algorithm to identify and link the centers of the high emission regions from the spiral arm regions. Our code currently identifies the centers of the high emission regions, but more work is needed to link up these sites and draw out the spiral arms. Future work includes improving the code to better identify spiral arms and converting the code to work on the Astropy, a community-developed core Python package for Astronomy (Robitaille, T. P., et al. A&A 558, A33, 2013).

  16. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into a...

  17. Electromagnetic, flow and thermal study of a miniature planar spiral transformer with planar, spiral windings

    Directory of Open Access Journals (Sweden)

    J. B. DUMITRU

    2014-04-01

    Full Text Available This paper presents mathematical modeling and numerical simulation results for a miniature, planar, spiral transformer (MPST fabricated in micro-electromechanical MEMS technology. When the MPST is magnetic nanofluid cored, magnetization body forces occur, entraining it into a complex flow. This particular MPST design is then compared with other competing solutions concerning the lumped (circuit parameters. Finally, the heat transfer problem is solved for different electromagnetic working conditions to assess the thermal loads inside the MPST.

  18. Spiral model pilot project information model

    Science.gov (United States)

    1991-01-01

    The objective was an evaluation of the Spiral Model (SM) development approach to allow NASA Marshall to develop an experience base of that software management methodology. A discussion is presented of the Information Model (IM) that was used as part of the SM methodology. A key concept of the SM is the establishment of an IM to be used by management to track the progress of a project. The IM is the set of metrics that is to be measured and reported throughout the life of the project. These metrics measure both the product and the process to ensure the quality of the final delivery item and to ensure the project met programmatic guidelines. The beauty of the SM, along with the IM, is the ability to measure not only the correctness of the specification and implementation of the requirements but to also obtain a measure of customer satisfaction.

  19. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos >> NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: ...

  20. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia ...

  1. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: ...

  2. Processing fine stainless-steel slag using spiral concentration.

    Science.gov (United States)

    Wolfe, Eric R; Klima, Mark S

    2008-04-01

    In this study, the effectiveness of spiral concentration to process a fine (-1 mm) stainless-steel slag was evaluated. Specifically, testing was conducted to determine the feasibility of producing a high metal content stainless steel product and a low metal content aggregate product. This involved investigating a key operating variable for both five-and seven-turn spiral concentrators. The raw slag and spiral products were characterized to determine their respective size and metal distributions. Separation testing was carried out using the two full-scale spiral concentrators to evaluate the effects of feed solids concentration on spiral performance at solids feed rates ranging from 15 to 30 kg/min. The results indicated that under certain conditions, a high-quality metal fraction could be produced. For example, using the five-turn spiral, a product containing 95% metal was obtained at a low metal recovery. Both spirals were ineffective at concentrating the aggregate fraction. Overall, the feed solids concentration did not significantly affect the quality or recoveries of the products, particularly for feed solids concentrations less than 35% by weight. In order to improve the metal recoveries and to produce a low-metal aggregate material, reprocessing of the product streams and/or additional liberation of the raw slag would be required.

  3. Pancreatic adenocarcinoma : usefulness of two and three phase spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyeong Ah; Kim, Hyung Soo; Park, Cheol Min; Cha, In Ho [Korea Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-10-01

    To evaluate the efficacy of each phases in two and three phase spiral CT in the detection of pancreatic adenocarcinoma. Two phase spiral CT images of 18 patients and three phase spiral CT images of 12 patients with pathologically-proven pancreatic ductal adenocarcinoma were retrospectively compared. Using a single spiral scan, images of early and delayed phases were obtained at 43 seconds and 2{approx}3minutes respectively initiating the after administration of 100-120cc of contrast material (2{approx}3cc/sec), Images of arterial, portal and delayed phases were also obtained at 25 and 60 seconds, and 3{approx}4minutes, respectively, by the use of a double spiral scan. CT scans were performed with 10mm collimation at 1:1 pitch table speed. Contrast between the tumor and adjacent pancreatic parenchyma were compared and graded and enhancement pattern of the tumor were analysed together. In 12 patients (66.7%), images of the early phase were superior to those of the delayed phase. images of the portal phase were superior to those of the arterial phase. Enhancement of tumor was seen in four patients;all tumors were less than 3cm in size. The early phase of two phase spiral CT is superior to the delayed phase and the portal phase of three phase spiral CT is superior to the arterial phase. Both arterial and portal phases are superior to the delayed phase.

  4. Spiral Antenna-Coupled Microbridge Structures for THz Application.

    Science.gov (United States)

    Gou, Jun; Zhang, Tian; Wang, Jun; Jiang, Yadong

    2017-12-01

    Bolometer sensor is a good candidate for THz imaging due to its compact system, low cost, and wideband operation. Based on infrared microbolometer structures, two kinds of antenna-coupled microbridge structures are proposed with different spiral antennas: spiral antenna on support layer and spiral antenna with extended legs. Aiming at applications in detection and imaging, simulations are carried out mainly for optimized absorption at 2.52 THz, which is the radiation frequency of far-infrared CO 2 lasers. The effects of rotation angle, line width, and spacing of the spiral antenna on THz wave absorption of microbridge structures are discussed. Spiral antenna, with extended legs, is a good solution for high absorption rate at low absorption frequency and can be used as electrode lead simultaneously for simplified manufacturing process. A spiral antenna-coupled microbridge structure with an absorption rate of more than 75% at 2.52 THz is achieved by optimizing the structure parameters. This research demonstrates the use of different spiral antennas for enhanced and tunable THz absorption of microbridge structures and provides an effective way to fabricate THz microbolometer detectors with great potential in the application of real-time THz imaging.

  5. A Software Development Simulation Model of a Spiral Process

    Science.gov (United States)

    Mizell, Carolyn; Malone, Linda

    2007-01-01

    There is a need for simulation models of software development processes other than the waterfall because processes such as spiral development are becoming more and more popular. The use of a spiral process can make the inherently difficult job of cost and schedule estimation even more challenging due to its evolutionary nature, but this allows for a more flexible process that can better meet customers' needs. This paper will present a discrete event simulation model of spiral development that can be used to analyze cost and schedule effects of using such a process in comparison to a waterfall process.

  6. Fabrication techniques of X-ray spiral zone plates

    International Nuclear Information System (INIS)

    Gao Nan; Zhu Xiaoli; Li Hailiang; Xie Changqing

    2010-01-01

    The techniques to make X-ray spiral zone plates using electron beam and X-ray lithography were studied. A master mask was fabricated on polyimide membrane by E-beam lithography and micro-electroplating. Spiral zone plates were efficiently replicated by X-ray lithography and micro-electroplating. By combining the techniques, spiral zone plates at 1 keV were successfully fabricate. With an outermost zone width of the 200 nm, and the gold absorbers thickness of 700 nm, the high quality zone plates can be used for X-ray phase contrast microscopy.(authors)

  7. Comments on H. Arp 'The persistent problem of spiral galaxies'

    International Nuclear Information System (INIS)

    Alfven, H.

    1987-04-01

    In his paper 'The persistent problem of Spiral Galaxies' H. Arp criticises the standard theory of spiral galaxies and demonstrates that introduction of plasma theory is necessary in order to understand the structure of spiral galaxies. In the present paper arguments are given in support of Arp's theory and suggestions are made how Arp's ideas should be developed. An important result of Arp's new approach is that there is no convincing argument for the belief that there is a 'missing mass'. This is important from a cosmological point of view. (author)

  8. Harmonic oscillator in an elastic medium with a spiral dislocation

    Science.gov (United States)

    Maia, A. V. D. M.; Bakke, K.

    2018-02-01

    We investigate the behaviour of a two-dimensional harmonic oscillator in an elastic medium that possesses a spiral dislocation (an edge dislocation). We show that the Schrödinger equation for harmonic oscillator in the presence of a spiral dislocation can be solved analytically. Further, we discuss the effects of this topological defect on the confinement to a hard-wall confining potential. In both cases, we analyse if the effects of the topology of the spiral dislocation gives rise to an Aharonov-Bohm-type effect for bound states.

  9. Fluid flow in a spiral device used for irradiation of biological fluids.

    Science.gov (United States)

    Nikolof, Todd; Prakash, Mahesh; Cleary, Paul W; Bertolini, Joseph

    2013-01-01

    The manufacture of plasma-derived therapeutics includes dedicated viral inactivation steps to minimize the risk of infection. Traditional viral inactivation methods are effective for the removal and inactivation of enveloped viruses, but less effective against small nonenveloped viruses. UV-C irradiation has been demonstrated to be an effective means of inactivating such viruses. The UVivatec lab system consists of a spiral tube around an UV-C irradiation source. Flow of a solution through the chamber generates and ensures controlled mixing and uniform exposure to irradiation. A detailed assessment of the effect of flow rate, alternate cross sectional design and scale up of the irradiation chamber on Dean vortices was performed using the smoothed particle hydrodynamics method. The aim was to provide a basis for setting flow rate limits and using a laboratory scale apparatus to model viral inactivation in larger manufacturing scale equipment. The effect of flow rate related changes on the fluence rate was also investigated through chemical actinometry studies. The data were consistent with the simulations indicating that Dean vortices were present at low flow rates, but dissipated at higher flow rates through the spiral chamber. Importantly, this work also allowed a correlation between the small system and large scale system to be established. This will greatly facilitate process development and viral validation studies. Copyright © 2013 American Institute of Chemical Engineers.

  10. Lunar Lava Tube Sensing

    Science.gov (United States)

    York, Cheryl Lynn; Walden, Bryce; Billings, Thomas L.; Reeder, P. Douglas

    1992-01-01

    Large (greater than 300 m diameter) lava tube caverns appear to exist on the Moon and could provide substantial safety and cost benefits for lunar bases. Over 40 m of basalt and regolith constitute the lava tube roof and would protect both construction and operations. Constant temperatures of -20 C reduce thermal stress on structures and machines. Base designs need not incorporate heavy shielding, so lightweight materials can be used and construction can be expedited. Identification and characterization of lava tube caverns can be incorporated into current precursor lunar mission plans. Some searches can even be done from Earth. Specific recommendations for lunar lava tube search and exploration are (1) an Earth-based radar interferometer, (2) an Earth-penetrating radar (EPR) orbiter, (3) kinetic penetrators for lunar lava tube confirmation, (4) a 'Moon Bat' hovering rocket vehicle, and (5) the use of other proposed landers and orbiters to help find lunar lava tubes.

  11. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1983-08-01

    A review of the performance of steam generator tubes in 110 water-cooled nuclear power reactors showed that tubes were plugged at 46 (42 percent) of the reactors. The number of tubes removed from service increased from 1900 (0.14 percent) in 1980 to 4692 (0.30 percent) in 1981. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that used all-volatile treatment since start-up. At one reactor a large number of degraded tubes were repaired by sleeving which is expected to become an important method of tube repair in the future

  12. Manual tube welding torch

    International Nuclear Information System (INIS)

    Kiefer, J.H.; Smith, D.J.

    1981-01-01

    In a welding torch which fits over a tube intermediate the ends thereof for welding the juncture between the tube and a boss on the back side of a tube plate, a split housing encloses a tungsten electrode, a filler wire duct and a fiber optic bundle arranged to observe the welding process. A shielding gas duct is provided in the housing. A screw is provided for setting electrode/work distance. Difficult remote tube welding operations can be performed with the apparatus. (author)

  13. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1984-10-01

    A review of the performance of steam generator tubes in 116 water-cooled nuclear power reactors showed that tubes were plugged at 54 (46 percent) of the reactors. The number of tubes removed from service decreased from 4 692 (0.30 percent) in 1981 to 3 222 (0.20 percent) in 1982. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that have used only volatile treatment, with or without condensate demineralization

  14. Wound tube heat exchanger

    Science.gov (United States)

    Ecker, Amir L.

    1983-01-01

    What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

  15. Sapphire tube pressure vessel

    Science.gov (United States)

    Outwater, John O.

    2000-01-01

    A pressure vessel is provided for observing corrosive fluids at high temperatures and pressures. A transparent Teflon bag contains the corrosive fluid and provides an inert barrier. The Teflon bag is placed within a sapphire tube, which forms a pressure boundary. The tube is received within a pipe including a viewing window. The combination of the Teflon bag, sapphire tube and pipe provides a strong and inert pressure vessel. In an alternative embodiment, tie rods connect together compression fittings at opposite ends of the sapphire tube.

  16. Fuel nozzle tube retention

    Energy Technology Data Exchange (ETDEWEB)

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  17. Software trends for both the GANIL and spiral control

    International Nuclear Information System (INIS)

    David, L.; Lecorche, E.

    1999-01-01

    The Ganil facility has been running with a new control system since 1993. Many improvements have been done since that time to bring new capabilities to the system. So, in February 1996, when the Spiral control system was designed, it was mainly considered as an extension of the Ganil control system. This paper briefly recalls the basic architecture of the whole control system and the main choices upon which it relies. Then it presents the new software trends, to show how the Spiral control system has been integrated alongside the existing one. The last part describe the new developments and the most significant functionalities it brings as seen from the operator point of view, with some emphasis about the application programs for beam tuning. Indeed, these new programs have to be provided both for the spiral tuning with exotic ions beams and for the coupling of the Spiral and older Ganil facilities. (authors)

  18. Effects of abnormal excitation on the dynamics of spiral waves

    Science.gov (United States)

    Min-Yi, Deng; Xue-Liang, Zhang; Jing-Yu, Dai

    2016-01-01

    The effect of physiological and pathological abnormal excitation of a myocyte on the spiral waves is investigated based on the cellular automaton model. When the excitability of the medium is high enough, the physiological abnormal excitation causes the spiral wave to meander irregularly and slowly. When the excitability of the medium is low enough, the physiological abnormal excitation leads to a new stable spiral wave. On the other hand, the pathological abnormal excitation destroys the spiral wave and results in the spatiotemporal chaos, which agrees with the clinical conclusion that the early after depolarization is the pro-arrhythmic mechanism of some anti-arrhythmic drugs. The mechanisms underlying these phenomena are analyzed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11365003 and 11165004).

  19. Effects of semiclassical spiral fluctuations on hole dynamics

    Science.gov (United States)

    Hamad, I. J.; Manuel, L. O.; Trumper, A. E.

    2012-01-01

    We investigate the dynamics of a single hole coupled to the spiral fluctuations related to the magnetic ground states of the antiferromagnetic J1-J2-J3 Heisenberg model on a square lattice. Using exact diagonalization on finite size clusters and the self-consistent Born approximation in the thermodynamic limit, we find, as a general feature, a strong reduction of the quasiparticle weight along the spiral phases of the magnetic phase diagram. For an important region of the Brillouin zone the hole spectral functions are completely incoherent, whereas at low energies the spectral weight is redistributed on several irregular peaks. We find a characteristic value of the spiral pitch Q=(0.7,0.7)π, for which the available phase space for hole scattering is maximum. We argue that this behavior is due to the nontrivial interference of the magnon-assisted and the free-hopping mechanism for hole motion, characteristic of a hole coupled to semiclassical spiral fluctuations.

  20. Measurement and structure of spiral wave response functions

    Science.gov (United States)

    Dierckx, Hans; Verschelde, Henri; Panfilov, Alexander V.

    2017-09-01

    The rotating spiral waves that emerge in diverse natural and man-made systems typically exhibit a particle-like behaviour since their adjoint critical eigenmodes (response functions) are often seen to be localised around the spiral core. We present a simple method to numerically compute response functions for circular-core and meandering spirals by recording their drift response to many elementary perturbations. Although our method is computationally more expensive than solving the adjoint system, our technique is fully parallellisable, does not suffer from memory limitations and can be applied to experiments. For a cardiac tissue model with the linear spiral core, we find that the response functions are localised near the turning points of the trajectory.

  1. Data Fusion Tool for Spiral Bevel Gear Condition Indicator Data

    Science.gov (United States)

    Dempsey, Paula J.; Antolick, Lance J.; Branning, Jeremy S.; Thomas, Josiah

    2014-01-01

    Tests were performed on two spiral bevel gear sets in the NASA Glenn Spiral Bevel Gear Fatigue Test Rig to simulate the fielded failures of spiral bevel gears installed in a helicopter. Gear sets were tested until damage initiated and progressed on two or more gear or pinion teeth. During testing, gear health monitoring data was collected with two different health monitoring systems. Operational parameters were measured with a third data acquisition system. Tooth damage progression was documented with photographs taken at inspection intervals throughout the test. A software tool was developed for fusing the operational data and the vibration based gear condition indicator (CI) data collected from the two health monitoring systems. Results of this study illustrate the benefits of combining the data from all three systems to indicate progression of damage for spiral bevel gears. The tool also enabled evaluation of the effectiveness of each CI with respect to operational conditions and fault mode.

  2. Relative frequencies of supernovae versus properties of spiral hosts

    OpenAIRE

    Hakobyan, A. A.; Nazaryan, T. A.; Adibekyan, V. Zh.; Petrosian, A. R.; Aramyan, L. S.; Kunth, D.; Mamon, G. A.; de Lapparent, V.; Bertin, E.; Gomes, J. M.; Turatto, M.

    2013-01-01

    In this work, we present an analysis of SNe number ratios in spiral galaxies with different morphological subtypes, luminosities, sSFR, and metallicities, to provide important information about the physical properties of the progenitor populations.

  3. Simulating Fatigue Crack Growth in Spiral Bevel Pinion

    National Research Council Canada - National Science Library

    Ural, Ani

    2003-01-01

    .... To obtain a more detailed understanding of the contact between a cracked pinion tooth in mesh with an uncracked gear tooth, three-dimensional contact analyses were performed on a spiral bevel gear...

  4. Cassini discovers a kinematic spiral ring around Saturn.

    Science.gov (United States)

    Charnoz, S; Porco, C C; Déau, E; Brahic, A; Spitale, J N; Bacques, G; Baillie, K

    2005-11-25

    Since the time of the Voyager flybys of Saturn in 1980-1981, Saturn's eccentric F ring has been known to be accompanied on either side by faint strands of material. New Cassini observations show that these strands, initially interpreted as concentric ring segments, are in fact connected and form a single one-arm trailing spiral winding at least three times around Saturn. The spiral rotates around Saturn with the orbital motion of its constituent particles. This structure is likely the result of differential orbital motion stretching an initial cloud of particles scattered from the dense core of the F ring. Different scenarios of formation, implying ringlet-satellite interactions, are explored. A recently discovered moon candidate, S/2004 S6, is on an orbit that crosses the F-ring core at the intersection of the spiral with the ring, which suggests a dynamical connection between S/2004 S6 and the spiral.

  5. Dosimetry in dental radiology. Dentascan spiral CT versus panoramic radiography

    International Nuclear Information System (INIS)

    Villari, N.; Stecco, A.; Zatelli, G.

    1999-01-01

    The study compares the doses absorbed by the dentomaxillary area in spiral CT and panoramic examinations. The dose measurements demonstrate that patients receive smaller doses with panoramic radiography than with spiral CT with Dentascan. After following for some variations from instrumental differences, they are in substantial agreement with literature data. Further investigations are needed considering the radiobiological risk related to the growing spread of Dentascan examinations [it

  6. Scintigraphic diagnosis of spiral fracture in young children

    International Nuclear Information System (INIS)

    Hossein-Foucher, C.; Venel, H.; Lecouffe, P.; Ythier, H.; Legghe, R.; Marchandise, X.

    1988-01-01

    8 cases of unsuspected bone fracture in children, identified at bone scan are reported. Common features were the children's young age (1 to 3 years), the absence of clinical suspicion, the initially normal X-rays, the fracture type (spiral fracture of the tibia undisplaced), and the uniform appearance of the bone scan. These data confim the value of bone scan in limping children and suggest that spiral fracture of the tibia is a frequent and underdiagnosed condition in children [fr

  7. The accelerated ISOL technique and the SPIRAL project

    International Nuclear Information System (INIS)

    Villari, A.C.C.

    2001-01-01

    The accelerated ISOL technique is presented as an introduction to the present status of the SPIRAL facility. SPIRAL is based on the very high intensity light and heavy ion beams available at GANIL. The facility will deliver radioactive beams with energies in the range between 1.7 A and 25 A MeV. The presently target-ion source production system, as well the new developments undertaken by the target ion-source group at GANIL are presented. (authors)

  8. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  9. Steam generator tube failures

    International Nuclear Information System (INIS)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

  10. Spiralizations and tropisms in Arabidopsis roots.

    Science.gov (United States)

    Migliaccio, F; Piconese, S

    2001-12-01

    When Arabidopsis seedlings are grown on a hard-agar plate, their primary roots show characteristic spiralling movements, apparent as waves, coils and torsions, together with a slanting toward the right-hand side. All these movements are believed to be the result of three different processes acting on the roots: circumnutation, positive gravitropism and negative thigmotropism. The basic movement of the roots is described as that of a growing right-handed helix, which, because of the root tip hitting the agar plate, is continuously switched from the right-hand to the left-hand of the growth direction, and vice versa. This movement also produces a slanting root-growth direction toward the right-hand because of the incomplete waves made by the right-handed root to the left-hand. By contrast, the torsions seen in the coils and waves are interpreted as artefacts that form as an adaptation of the three-dimensional root helix to the flat two-dimensional agar surface.

  11. Noncontrast peripheral MRA with spiral echo train imaging.

    Science.gov (United States)

    Fielden, Samuel W; Mugler, John P; Hagspiel, Klaus D; Norton, Patrick T; Kramer, Christopher M; Meyer, Craig H

    2015-03-01

    To develop a spin echo train sequence with spiral readout gradients with improved artery-vein contrast for noncontrast angiography. Venous T2 becomes shorter as the echo spacing is increased in echo train sequences, improving contrast. Spiral acquisitions, due to their data collection efficiency, facilitate long echo spacings without increasing scan times. Bloch equation simulations were performed to determine optimal sequence parameters, and the sequence was applied in five volunteers. In two volunteers, the sequence was performed with a range of echo times and echo spacings to compare with the theoretical contrast behavior. A Cartesian version of the sequence was used to compare contrast appearance with the spiral sequence. Additionally, spiral parallel imaging was optionally used to improve image resolution. In vivo, artery-vein contrast properties followed the general shape predicted by simulations, and good results were obtained in all stations. Compared with a Cartesian implementation, the spiral sequence had superior artery-vein contrast, better spatial resolution (1.2 mm(2) versus 1.5 mm(2) ), and was acquired in less time (1.4 min versus 7.5 min). The spiral spin echo train sequence can be used for flow-independent angiography to generate three-dimensional angiograms of the periphery quickly and without the use of contrast agents. © 2014 Wiley Periodicals, Inc.

  12. Mechanics and spiral formation in the rat cornea.

    Science.gov (United States)

    Mohammad Nejad, T; Iannaccone, S; Rutherford, W; Iannaccone, P M; Foster, C D

    2015-01-01

    During the maturation of some mammals such as mice and rats, corneal epithelial cells tend to develop into patterns such as spirals over time. A better understanding of these patterns can help to understand how the organ develops and may give insight into some of the diseases affecting corneal development. In this paper, a framework for explaining the development of the epithelial cells forming spiral patterns due to the effect of tensile and shear strains is proposed. Using chimeric animals, made by combining embryonic cells from genetically distinguishable strains, we can observe the development of patterns in the cornea. Aggregates of cell progeny from one strain or the other called patches form as organs and tissue develop. The boundaries of these patches are fitted with logarithmic spirals on confocal images of adult rat corneas. To compare with observed patterns, we develop a three-dimensional large strain finite element model for the rat cornea under intraocular pressure to examine the strain distribution on the cornea surface. The model includes the effects of oriented and dispersed fibrils families throughout the cornea and a nearly incompressible matrix. Tracing the directions of critical strain vectors on the cornea surface leads to spiral-like curves that are compared to the observed logarithmic spirals. Good agreement between the observed and numerical curves supports the proposed assumption that shear and tensile strains facilitate sliding of epithelial cells to develop spiral patterns.

  13. Improved MRI thermometry with multiple-echo spirals.

    Science.gov (United States)

    Marx, Michael; Butts Pauly, Kim

    2016-09-01

    Low-bandwidth PRF shift thermometry is used to guide HIFU ablation treatments. Low sampling bandwidth is needed for high signal-to-noise ratio with short acquisition times, but can lead to off-resonance artifacts. In this work, improved multiple-echo thermometry is presented that allows for high bandwidth and reduced artifacts. It is also demonstrated with spiral sampling, to improve the trade-off between resolution, speed, and measurement precision. Four multiple-echo thermometry sequences were tested in vivo, one using two-dimensional Fourier transform (2DFT) sampling and three using spirals. The spiral sequences were individually optimized for resolution, for speed, and for precision. Multifrequency reconstruction was used to correct for off-resonance spiral artifacts. Additionally, two different multiecho temperature reconstructions were compared. Weighted combination of per-echo phase differences gave significantly better precision than least squares off-resonance estimation. Multiple-echo 2DFT sequence obtained precision similar to single-echo 2DFT, while greatly increasing sampling bandwidth. The multiecho spiral acquisitions achieved 2× better resolution, 2.9× better uncertainty, or 3.4× faster acquisition time, without negatively impacting the other two design parameters as compared to single-echo 2DFT. Multiecho spiral thermometry greatly improves the capabilities of temperature monitoring, and could improve transcranial treatment monitoring capabilities. Magn Reson Med 76:747-756, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  14. Spiral instabilities in media supporting complex oscillations under periodic forcing

    Science.gov (United States)

    Gao, Qingyu; Li, Jun; Zhang, Kailong; Epstein, Irving R.

    2009-09-01

    The periodically forced Brusselator model displays temporal mixed-mode and quasiperiodic oscillations, period doubling, and chaos. We explore the behavior of such media as reaction-diffusion systems for investigating spiral instabilities. Besides near-core breakup and far-field breakup resulting from unstable modes in the radial direction or Doppler-induced instability (destabilization of the core's location), the observed complex phenomena include backfiring, spiral regeneration, and amplitude modulation from line defects. Amplitude modulation of spirals can evolve to chambered spirals resembling those found in nature, such as pine cones and sunflowers. When the forcing amplitude is increased, the spiral-tip meander evolves from simple rotation to complex petals, corresponding to transformation of the local dynamics from simple oscillations to mixed-mode, period-2, and quasiperiodic oscillations. The number of petals is related to the complexity of the mixed-mode oscillations. Spiral turbulence, standing waves, and homogeneous synchronization permeate the entire system when the forcing amplitude is further increased.

  15. High-Tc Superconducting Thick-Film Spiral Magnet: Development and Characterization of a Single Spiral Module

    National Research Council Canada - National Science Library

    McGinnis, W

    1997-01-01

    The objective of this project was to make characterized and numerically model prototype modules of a new type of superconducting electromagnet based on stacked spirals of superconducting thick films...

  16. Chest Tube Thoracostomy

    Science.gov (United States)

    ... in the space around the lungs (called a pleural effusion) . A chest tube may also be needed when a patient has ... or chest CT are also done to evaluate pleural fluid. If the X-ray shows a need for a chest tube to drain fluid or air, the procedure is ...

  17. Ventricular tachycardia following tube thoracotomy.

    Science.gov (United States)

    Hibbert, Benjamin; Lim, Toon Wei; Hibbert, Rebecca; Green, Martin; Gollob, Michael H; Davis, Darryl R

    2010-10-01

    Arrhythmias provoked by tube thoracotomy are a rare complication. We report a ventricular tachycardia after chest tube insertion for a device-related pneumothorax. Sinus rhythm was restored only by removal of the chest tube and insertion of a pliable pleural drain. Identification of the chest tube as an arrhythmic trigger following tube thoracotomy is essential in definitive management of refractory arrhythmias.

  18. Molybdenum Tube Characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Beaux II, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-07

    Chemical vapor deposition (CVD) techniques have been utilized to produce free-standing molybdenum tubes with the end goal of nuclear fuel clad applications. In order to produce tubes with properties desirable for this application, deposition rates were lowered requiring long deposition durations on the order of 50 hours. Standard CVD methods as well as fluidized-bed CVD (FBCVD) methods were applied towards these objectives. Characterization of the tubes produced in this manner revealed material suitable for fuel clad applications, but lacking necessary uniformity across the length of the tubes. The production of freestanding Mo tubes that possess the desired properties across their entire length represents an engineering challenge that can be overcome in a next iteration of the deposition system.

  19. Categorising YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2011-01-01

    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s...... technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition...... and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within...

  20. Clear New View of a Classic Spiral

    Science.gov (United States)

    2010-05-01

    ESO is releasing a beautiful image of the nearby galaxy Messier 83 taken by the HAWK-I instrument on ESO's Very Large Telescope (VLT) at the Paranal Observatory in Chile. The picture shows the galaxy in infrared light and demonstrates the impressive power of the camera to create one of the sharpest and most detailed pictures of Messier 83 ever taken from the ground. The galaxy Messier 83 (eso0825) is located about 15 million light-years away in the constellation of Hydra (the Sea Serpent). It spans over 40 000 light-years, only 40 percent the size of the Milky Way, but in many ways is quite similar to our home galaxy, both in its spiral shape and the presence of a bar of stars across its centre. Messier 83 is famous among astronomers for its many supernovae: vast explosions that end the lives of some stars. Over the last century, six supernovae have been observed in Messier 83 - a record number that is matched by only one other galaxy. Even without supernovae, Messier 83 is one of the brightest nearby galaxies, visible using just binoculars. Messier 83 has been observed in the infrared part of the spectrum using HAWK-I [1], a powerful camera on ESO's Very Large Telescope (VLT). When viewed in infrared light most of the obscuring dust that hides much of Messier 83 becomes transparent. The brightly lit gas around hot young stars in the spiral arms is also less prominent in infrared pictures. As a result much more of the structure of the galaxy and the vast hordes of its constituent stars can be seen. This clear view is important for astronomers looking for clusters of young stars, especially those hidden in dusty regions of the galaxy. Studying such star clusters was one of the main scientific goals of these observations [2]. When compared to earlier images, the acute vision of HAWK-I reveals far more stars within the galaxy. The combination of the huge mirror of the VLT, the large field of view and great sensitivity of the camera, and the superb observing conditions

  1. CHARACTERIZING SPIRAL ARM AND INTERARM STAR FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Kreckel, K.; Schinnerer, E.; Meidt, S. [Max Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Blanc, G. A. [Departamento de Astronomía, Universidad de Chile, Camino del Observatorio 1515, Las Condes, Santiago (Chile); Groves, B. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Adamo, A. [Department of Astronomy, The Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Hughes, A., E-mail: kreckel@mpia.de [CNRS, IRAP, 9 Av. du Colonel Roche, BP 44346, F-31028 Toulouse cedex 4 (France)

    2016-08-20

    Interarm star formation contributes significantly to a galaxy’s star formation budget and provides an opportunity to study stellar birthplaces unperturbed by spiral arm dynamics. Using optical integral field spectroscopy of the nearby galaxy NGC 628 with VLT/MUSE, we construct H α maps including detailed corrections for dust extinction and stellar absorption to identify 391 H ii regions at 35 pc resolution over 12 kpc{sup 2}. Using tracers sensitive to the underlying gravitational potential, we associate H ii regions with either arm (271) or interarm (120) environments. Using our full spectral coverage of each region, we find that most physical properties (luminosity, size, metallicity, ionization parameter) of H ii regions are independent of environment. We calculate the fraction of H α luminosity due to the background of diffuse ionized gas (DIG) contaminating each H ii region, and find the DIG surface brightness to be higher within H ii regions than in the surroundings, and slightly higher within arm H ii regions. Use of the temperature-sensitive [S ii]/H α line ratio instead of the H α surface brightness to identify the boundaries of H ii regions does not change this result. Using the dust attenuation as a tracer of the gas, we find depletion times consistent with previous work (2 × 10{sup 9} yr) with no differences between the arm and interarm, but this is very sensitive to the DIG correction. Unlike molecular clouds, which can be dynamically affected by the galactic environment, we see fairly consistent properties of H ii regions in both arm and interarm environments. This suggests either a difference in star formation and feedback in arms or a decoupling of dense star-forming clumps from the more extended surrounding molecular gas.

  2. The Globular Cluster System of the Spiral Galaxy NGC 7814

    Science.gov (United States)

    Rhode, Katherine L.; Zepf, Stephen E.

    2003-11-01

    We present the results of a wide-field photometric study of the globular cluster (GC) system of the edge-on Sab spiral NGC 7814. This is the first spiral to be fully analyzed from our survey of the GC systems of a large sample of galaxies beyond the Local Group. NGC 7814 is of particular interest because a previous study estimated that it has 500-1000 GCs, giving it the largest specific frequency (SN) known for a spiral. Understanding this galaxy's GC system is important in terms of our understanding of the GC populations of spirals in general and has implications for the formation of massive galaxies. We observed the galaxy in BVR filters with the WIYN 3.5 m telescope and used image classification and three-color photometry to select GC candidates. We also analyzed archival Hubble Space Telescope (HST) Wide Field Planetary Camera 2 images of NGC 7814, both to help quantify the contamination level of the WIYN GC candidate list and to detect GCs in the inner part of the galaxy halo. Combining HST data with high-quality ground-based images allows us to trace the entire radial extent of this galaxy's GC system and determine the total number of GCs directly through observation. We find that rather than being an especially high-SN spiral, NGC 7814 has <~200 GCs and SN~1, making it comparable to the two most well-studied spiral galaxies, the Milky Way and M31. We explore the implications of these results for models of the formation of galaxies and their GC systems. The initial results from our survey suggest that the GC systems of typical elliptical galaxies can be accounted for by the merger of two or more spirals, but that for highly luminous elliptical galaxies, additional physical processes may be needed.

  3. Research on performance of upstream pumping mechanical seal with different deep spiral groove

    International Nuclear Information System (INIS)

    Wang, Q; Chen, H L; Liu, T; Liu, Y H; Liu, Z B; Liu, D H

    2012-01-01

    As one new type of mechanical seal, Upstream Pumping Mechanical Seal has been widely used in fluid machinery. In this paper, structure of spiral groove is innovatively optimized to improve performance of Upstream Pumping Mechanical Seal with Spiral Groove: keeping the dam zone and the weir zone not changed, changing the bottom shape of spiral groove only, substituting different deep spiral groove for equal deep spiral groove. The simulation on Upstream Pumping Mechanical Seal with different deep spiral grooves is done using FVM method. According to calculation, the performances of opening force and pressure distribution on seals face are obtained. Five types of spiral grooves are analyzed, namely equal deep spiral groove, circumferential convergent ladder-like different deep spiral groove, circumferential divergent ladder-like different deep spiral groove, radial convergent ladder-like different deep spiral groove and radial divergent ladder-like different deep spiral groove. This paper works on twenty-five working conditions. The results indicate the performances of circumferential divergent 2-ladder different deep spiral groove are better than the others, with more opening force and better stabilization, while with the same leakage. The outcome provides theoretical support for application of Upstream Pumping Mechanical Seal with circumferential convergent ladder-like different deep spiral groove.

  4. Research on performance of upstream pumping mechanical seal with different deep spiral groove

    Science.gov (United States)

    Wang, Q.; Chen, H. L.; Liu, T.; Liu, Y. H.; Liu, Z. B.; Liu, D. H.

    2012-11-01

    As one new type of mechanical seal, Upstream Pumping Mechanical Seal has been widely used in fluid machinery. In this paper, structure of spiral groove is innovatively optimized to improve performance of Upstream Pumping Mechanical Seal with Spiral Groove: keeping the dam zone and the weir zone not changed, changing the bottom shape of spiral groove only, substituting different deep spiral groove for equal deep spiral groove. The simulation on Upstream Pumping Mechanical Seal with different deep spiral grooves is done using FVM method. According to calculation, the performances of opening force and pressure distribution on seals face are obtained. Five types of spiral grooves are analyzed, namely equal deep spiral groove, circumferential convergent ladder-like different deep spiral groove, circumferential divergent ladder-like different deep spiral groove, radial convergent ladder-like different deep spiral groove and radial divergent ladder-like different deep spiral groove. This paper works on twenty-five working conditions. The results indicate the performances of circumferential divergent 2-ladder different deep spiral groove are better than the others, with more opening force and better stabilization, while with the same leakage. The outcome provides theoretical support for application of Upstream Pumping Mechanical Seal with circumferential convergent ladder-like different deep spiral groove.

  5. RESULTS OF INVESTIGATIONS ON THERMAL CHARACTERISTICS OF AIR HEATER BUNDLE MADE OF BIMETALLIC FINNED TUBES

    Directory of Open Access Journals (Sweden)

    V. B. Kuntysh

    2014-01-01

    Full Text Available The paper presents a scheme and description of a new aerodynamic stand that has a 300x300 mm cross-section operating channel. The stand is used for studying thermal and aerodynamic characteristics of bundles made of finned tubes of actual dimensions in crossflow. The paper provides results of an exploratory test pertaining to heat transfer and resistance of four row staggered bundle made of tubes with aluminium spiral fins having outside diameter of 26 mm which are used in the systems of ventilation, air-conditioning and heating of buildings and also in transport heat exchangers.

  6. On the rolling of asymmetric inorganic-surfactant membrane into uncapped mesophase tubes

    Energy Technology Data Exchange (ETDEWEB)

    Shen Pouyan [Institute of Materials Science and Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China)]. E-mail: pshen@mail.nsysu.edu.tw; Fahn, Y.-Y. [Department of Chemical Engineering, Tong-Fang Institute of Technology, Hu-Nei, Kaohsiung 829, Taiwan (China); Su, A.-C. [Institute of Materials Science and Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China)

    2005-01-01

    On the basis of analytical electron microscopic observations, we propose that the water-air interface-mediated and aluminosilicate-encased lamellar mesophase, with epitaxial hexagonal mesophase adjoined from the water-side, roll into uncapped mesophase tubes in which the lamellar mesophase serves as the inner wall. This mechanism is consistent with the air bound hydrophobic nature of surfactant tail as well as intrinsic anisotropy in the distribution of charge and polymerization density across the mesophase interface. We show also that spiral rolling of the asymmetric composite membrane typically resulted in disordering and dislocations in the lamellar phase near the hinge, with the tapered end rolling into concentric tube.

  7. Interactions between vortex tubes and magnetic-flux rings at high kinetic and magnetic Reynolds numbers

    Science.gov (United States)

    Kivotides, Demosthenes

    2018-03-01

    The interactions between vortex tubes and magnetic-flux rings in incompressible magnetohydrodynamics are investigated at high kinetic and magnetic Reynolds numbers, and over a wide range of the interaction parameter. The latter is a measure of the turnover time of the large-scale fluid motions in units of the magnetic damping time, or of the strength of the Lorentz force in units of the inertial force. The small interaction parameter results, which are related to kinematic turbulent dynamo studies, indicate the evolution of magnetic rings into flattened spirals wrapped around the vortex tubes. This process is also observed at intermediate interaction parameter values, only now the Lorentz force creates new vortical structures at the magnetic spiral edges, which have a striking solenoid vortex-line structure, and endow the flattened magnetic-spiral surfaces with a curvature. At high interaction parameter values, the decisive physical factor is Lorentz force effects. The latter create two (adjacent to the magnetic ring) vortex rings that reconnect with the vortex tube by forming an intriguing, serpentinelike, vortex-line structure, and generate, in turn, two new magnetic rings, adjacent to the initial one. In this regime, the morphologies of the vorticity and magnetic field structures are similar. The effects of these structures on kinetic and magnetic energy spectra, as well as on the direction of energy transfer between flow and magnetic fields, are also indicated.

  8. Isolated Fallopian Tube Torsion

    Directory of Open Access Journals (Sweden)

    S. Kardakis

    2013-01-01

    Full Text Available Isolated torsion of the Fallopian tube is a rare gynecological cause of acute lower abdominal pain, and diagnosis is difficult. There are no pathognomonic symptoms; clinical, imaging, or laboratory findings. A preoperative ultrasound showing tubular adnexal masses of heterogeneous echogenicity with cystic component is often present. Diagnosis can rarely be made before operation, and laparoscopy is necessary to establish the diagnosis. Unfortunately, surgery often is performed too late for tube conservation. Isolated Fallopian tube torsion should be suspected in case of acute pelvic pain, and prompt intervention is necessary.

  9. Automation in tube finishing bay

    International Nuclear Information System (INIS)

    Bhatnagar, Prateek; Satyadev, B.; Raghuraman, S.; Syama Sundara Rao, B.

    1997-01-01

    Automation concept in tube finishing bay, introduced after the final pass annealing of PHWR tubes resulted in integration of number of sub-systems in synchronisation with each other to produce final cut fuel tubes of specified length, tube finish etc. The tube finishing bay which was physically segregated into four distinct areas: 1. tube spreader and stacking area, 2. I.D. sand blasting area, 3. end conditioning, wad blowing, end capping and O.D. wet grinding area, 4. tube inspection, tube cutting and stacking area has been studied

  10. CONCENTRIC TUBE-FOULING RIG FOR INVESTIGATION OF FOULING DEPOSIT FORMATION FROM PASTEURISER OF VISCOUS FOOD LIQUID

    Directory of Open Access Journals (Sweden)

    N. I. KHALID

    2013-02-01

    Full Text Available This paper reports the work on developing concentric tube-fouling rig, a new fouling deposit monitoring device. This device can detect and quantify the level of fouling deposit formation. It can also functioning as sampler for fouling deposit study, which can be attached at any food processing equipment. The design is initiated with conceptual design. The rig is designed with inner diameter of 7 cm and with tube length of 37 cm. A spiral insert with 34.5 cm length and with 5.4 cm diameter is fitted inside the tube to ensure the fluid flows around the tube. In this work, the rig is attached to the lab-scale concentric tube-pasteurizer to test its effectiveness and to collect a fouling sample after pasteurization of pink guava puree. Temperature changes are recorded during the pasteurization and the data is used to plot the heat transfer profile. Thickness of the fouling deposit is also measured. The trends for thickness, heat resistance profile and heat transfer profile for concentric tube-fouling rig matched the trends obtained from lab-scale concentric tube-pasteurizer very well. The findings from this work have shown a good potential of this rig however there is a limitation with spiral insert, which is discussed in this paper.

  11. Dynamic study of the larynx with spiral CT

    International Nuclear Information System (INIS)

    Park, Jong Yeon; Choi, Chang Ho; Yoon, Chi Soon; Kim, Yoon Gyoo; Nam, Sang Hwa; Kim, Kun Il; Kim, Byung Soo; Wang, Soo Guen

    1994-01-01

    It is essential to know the functional and morphologic changes of the larynx in the evaluation of laryngeal lesions. Conventional CT which has relatively long examination time is not suitable for this aim. The purposes of this study are to evaluate the capability of spiral CT in the dynamic study of the larynx and to know whether this new technique can replace conventional laryngography or not. Five healthy volunteers and 20 patients with laryngeal lesions underwent spiral dynamic CT scans with 3-dimensional reconstruction of the mucosal surface. A series of spiral CT scans were done while the volunteers performed various laryngeal positions to obtain the functional and morphologic information. The maneuvers used were: quite breathing, 'E' phonation, Valsalva maneuver, modified Valsalva maneuver, and a new method of our own, 'modified breath holding' technique. The patients were scanned when in quite breathing. Additional scans were obtained by using the 'modified breath holding' technique. The dynamic study with spiral CT could provide high resolutional images which nicely depicted the mobility of vocal cords and the mucosal changes of the laryngeal cavity in both healthy volunteer and patient groups. In patient group, the new 'modified breath holding' technique was easier and more reproducible than other maneuvers. Spiral CT allows a dynamic study of the larynx and can be a new alternative of laryngography

  12. On wave dark matter in spiral and barred galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Medina, Luis A.; Matos, Tonatiuh [Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, A.P. 14-740, 07000 México D.F., México. (Mexico); Bray, Hubert L., E-mail: lmedina@fis.cinvestav.mx, E-mail: bray@math.duke.edu, E-mail: tmatos@fis.cinvestav.mx [Mathematics Department, Duke University, Box 90320, Durham, NC 27708 (United States)

    2015-12-01

    We recover spiral and barred spiral patterns in disk galaxy simulations with a Wave Dark Matter (WDM) background (also known as Scalar Field Dark Matter (SFDM), Ultra-Light Axion (ULA) dark matter, and Bose-Einstein Condensate (BEC) dark matter). Here we show how the interaction between a baryonic disk and its Dark Matter Halo triggers the formation of spiral structures when the halo is allowed to have a triaxial shape and angular momentum. This is a more realistic picture within the WDM model since a non-spherical rotating halo seems to be more natural. By performing hydrodynamic simulations, along with earlier test particles simulations, we demonstrate another important way in which wave dark matter is consistent with observations. The common existence of bars in these simulations is particularly noteworthy. This may have consequences when trying to obtain information about the dark matter distribution in a galaxy, the mere presence of spiral arms or a bar usually indicates that baryonic matter dominates the central region and therefore observations, like rotation curves, may not tell us what the DM distribution is at the halo center. But here we show that spiral arms and bars can develop in DM dominated galaxies with a central density core without supposing its origin on mechanisms intrinsic to the baryonic matter.

  13. Spiral scan long object reconstruction through PI line reconstruction

    International Nuclear Information System (INIS)

    Tam, K C; Hu, J; Sourbelle, K

    2004-01-01

    The response of a point object in a cone beam (CB) spiral scan is analysed. Based on the result, a reconstruction algorithm for long object imaging in spiral scan cone beam CT is developed. A region-of-interest (ROI) of the long object is scanned with a detector smaller than the ROI, and a portion of it can be reconstructed without contamination from overlaying materials. The top and bottom surfaces of the ROI are defined by two sets of PI lines near the two ends of the spiral path. With this novel definition of the top and bottom ROI surfaces and through the use of projective geometry, it is straightforward to partition the cone beam image into regions corresponding to projections of the ROI, the overlaying objects or both. This also simplifies computation at source positions near the spiral ends, and makes it possible to reduce radiation exposure near the spiral ends substantially through simple hardware collimation. Simulation results to validate the algorithm are presented

  14. Continuing research on the classical spiraling photon model

    Science.gov (United States)

    Li, Hongrui

    2014-11-01

    Based no the classical spiraling photon model proposed by Hongrui Li, the laws of reflection, refraction of a single photon can be derived. Moreover, the polarization, total reflection, evanescent wave and Goos-Hanchen shift of a single photon can be elucidated. However, this photon model is still unfinished. Especially, the spiraling diameter of a photon is not definite. In this paper, the continuous research works on this new theory are reported. According to the facts that the diffraction limit of light and the smallest diameter of the focal spot of lenses are all equal to the wavelength λ of the light, we can get that the spiraling diameter of a photon equals to the wavelength λ, so we gain that the angle between the linear velocity of the spiraling photon υ and the component of the linear velocity in the forward direction υb is 45°, and the energy of a classical spiraling photon E = (1/2)mυ2 = (1/2)m2c2 = mc2. This coincides with Einstein's mass-energy relation. While it is obtained that the velocity of the evanescent wave in the vacuum is slower than the velocity of light in glass in straight line. In such a way, the optical fiber can slow the light down. In addition, the force analysis of a single photon in optical tweezers system is discussed. And the reason that the laser beam can capture the particle slightly downstream from the focal point can be explained.

  15. On wave dark matter in spiral and barred galaxies

    International Nuclear Information System (INIS)

    Martinez-Medina, Luis A.; Matos, Tonatiuh; Bray, Hubert L.

    2015-01-01

    We recover spiral and barred spiral patterns in disk galaxy simulations with a Wave Dark Matter (WDM) background (also known as Scalar Field Dark Matter (SFDM), Ultra-Light Axion (ULA) dark matter, and Bose-Einstein Condensate (BEC) dark matter). Here we show how the interaction between a baryonic disk and its Dark Matter Halo triggers the formation of spiral structures when the halo is allowed to have a triaxial shape and angular momentum. This is a more realistic picture within the WDM model since a non-spherical rotating halo seems to be more natural. By performing hydrodynamic simulations, along with earlier test particles simulations, we demonstrate another important way in which wave dark matter is consistent with observations. The common existence of bars in these simulations is particularly noteworthy. This may have consequences when trying to obtain information about the dark matter distribution in a galaxy, the mere presence of spiral arms or a bar usually indicates that baryonic matter dominates the central region and therefore observations, like rotation curves, may not tell us what the DM distribution is at the halo center. But here we show that spiral arms and bars can develop in DM dominated galaxies with a central density core without supposing its origin on mechanisms intrinsic to the baryonic matter

  16. X-ray tube

    International Nuclear Information System (INIS)

    Webley, R.S.

    1975-01-01

    The object of the invention described is to provide an X-ray tube providing a scanned X-ray output which does not require a scanned electron beam. This is obtained by an X-ray tube including an anode which is rotatable about an axis, and a source of a beam of energy, for example an electron beam, arranged to impinge on a surface of the anode to generate X-radiation substantially at the region of incidence on the anode surface. The anode is rotatable about the axis to move the region of incidence over the surface. The anode is so shaped that the rotation causes the region of incidence to move in a predetermined manner relative to fixed parts of the tube so that the generated X-radiation is scanned in a predetermined manner relative to the tube. (UK)

  17. Tube Alinement for Machining

    Science.gov (United States)

    Garcia, J.

    1984-01-01

    Tool with stepped shoulders alines tubes for machining in preparation for welding. Alinement with machine tool axis accurate to within 5 mils (0.13mm) and completed much faster than visual setup by machinist.

  18. Steam generator tube performance

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1982-04-01

    The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1980. Tube defects occurred at 38% of the 97 reactors surveyed. This is a marginal improvement over 1979 when defects occurred at 41% of the reactors. The number of failed tubes was also lower, 0.14% of the tubes in service in 1980 compared with 0.20% of those in service in 1979. Analysis of the causes of these failures indicates that stress corrosion cracking was the leading failure mechanism. Reactors that used all-volatile treatment of secondary water, with or without full-flow condensate demineralization since start-up showed the lowest incidence of corrosion-related defects

  19. Ear tube insertion

    Science.gov (United States)

    ... mastoiditis) or the brain, or that damages nearby nerves Injury to the ear after sudden changes in ... does not heal after the tube falls out. Most of the time, these problems DO NOT last long. They also ...

  20. Tube Feeding Troubleshooting Guide

    Science.gov (United States)

    ... the diameter is measured in units known as French sizes, or “Fr”; a low profile tube also ... your quality of life. You are encouraged to speak with your physician, dietitian, home care company, or ...

  1. Magnesium tube hydroforming

    Energy Technology Data Exchange (ETDEWEB)

    Liewald, M.; Pop, R. [Institute for Metal Forming Technology (IFU), Stuttgart (Germany)

    2008-04-15

    Magnesium alloys reveal a good strength-to-weight ratio in the family of lightweight metals and gains potential to provide up to 30% mass savings compared to aluminium and up to 75 % compared to steel. The use of sheet magnesium alloys for auto body applications is however limited due to the relatively low formability at room temperature. Within the scope of this paper, extruded magnesium tubes, which are suitable for hydroforming applications, have been investigated. Results obtained at room temperature using magnesium AZ31 tubes show that circumferential strains are limited to a maximal value of 4%. In order to examine the influence of the forming temperature on tube formability, investigations have been carried out with a new die set for hot internal high pressure (IHP) forming at temperatures up to 400 C. Earlier investigations with magnesium AZ31 tubes have shown that fractures occur along the welding line at tubes extruded over a spider die, whereby a non-uniform expansion at bursting with an elongation value of 24% can be observed. A maximum circumferential strain of approx. 60% could be attained when seamless, mechanically pre-expanded and annealed tubes of the same alloy have been used. The effect of annealing time on materials forming properties shows a fine grained structure for sufficient annealing times as well as deterioration with a large increase at same time. Hence, seamless ZM21 tubes have been used in the current investigations. With these tubes, an increased tensile fracture strain of 116% at 350 C is observed as against 19% at 20 C, obtained by tensile testing of milled specimens from the extruded tubes. This behaviour is also seen under the condition of tool contact during the IHP forming process. To determine the maximum circumferential strain at different forming temperatures and strain rates, the tubes are initially bulged in a die with square cross-section under plane stress conditions. Thereafter, the tubes are calibrated by using an

  2. Power vacuum tubes handbook

    CERN Document Server

    Whitaker, Jerry

    2012-01-01

    Providing examples of applications, Power Vacuum Tubes Handbook, Third Edition examines the underlying technology of each type of power vacuum tube device in common use today. The author presents basic principles, reports on new development efforts, and discusses implementation and maintenance considerations. Supporting mathematical equations and extensive technical illustrations and schematic diagrams help readers understand the material. Translate Principles into Specific Applications This one-stop reference is a hands-on guide for engineering personnel involved in the design, specification,

  3. Dynamics of tubes in fluid with tube-baffle interaction

    International Nuclear Information System (INIS)

    Chen, S.S.; Jendrzejczyk, J.A.; Wambsganss, M.W.

    1983-09-01

    Three series of tests are performed to evaluate the effects of tube to tube-support-plate (TSP) clearance on tube dynamic characteristics and instability phenomena for tube arrays in crossflow. Test results show that, for relatively large clearances, tubes may possess TSP-inactive modes in which the tubes rattle inside some of the tube-support-plate holes, and that the natural frequencies of TSP-inactive modes are lower than those of TSP-active modes, in which the support plates provide knife-edge type support. Tube response characteristics associated with TSP-inactive modes are sensitive to tube-to-TSP clearance, TSP thickness, excitation amplitude, tube alignment, and the fluid inside the clearance. In addition, tube response is intrinsically nonlinear, with the dominance of TSP-inactive or TSP-active modes depending on the magnitudes of different system parameters. In general, such a system is difficult to model; only a full-scale test can provide all the necessary characteristics. A tube array supported by TSPs with relatively large clearances may be subjected to dynamic instability in some of the TSP-inactive modes; tube response characteristics and impact forces on TSPs for a tube row are studied in detail in this report. Tube displacements associated with the instability of a TSP-inactive mode are small; however, impacts of the tube against TSPs may result in significant damage in a relatively short time. 52 figures

  4. Extending the GANIL control system for the SPIRAL project

    International Nuclear Information System (INIS)

    Lecorche, E.

    1997-01-01

    The SPIRAL project under construction at GANIL aims to deliver radioactive ion beams to the physicists by the end of 1998. In 1996, it has been proposed to achieve most of the SPIRAL control system as an extension of the system currently in use at GANIL. Therefore the main features of the GANIL control system design are first recalled. Then the paper shows how the GANIL control system should have been upgraded and extended to integrate the SPIRAL project. This evolution had to cope with the specific needs brought by the new machine and to consider the size of the project which is around one third of the GANIL control system volume. Lastly current status of the system is given. (author)

  5. Spiral waves in the Belousov-Zhabotinskii reaction

    Science.gov (United States)

    Keener, James P.; Tyson, John J.

    1986-09-01

    The beautiful spiral waves of oxidation in the Belousov-Zhabotinskii reaction are the source of many interesting and important questions about periods structures in excitable media. It has long been known that these spirals are similar to involutes of circles, at least some distance from the center, but until now, no way has been known to determine the correct wavelength and frequency. In this paper, we show that the parameters of a spiral wave can be viwed s eigenvalues of a problem with unique solution. The critical ingredients of the theory are the effects of curvature on the propagation of wavefronts in two-dimensional media, and the dispersion of plane waves Our analytical results are shown to be in good agreement with experimental data for the Belousov-Zhabotinskii reagent.

  6. A Twin Spiral Planar Antenna for UWB Medical Radars

    Directory of Open Access Journals (Sweden)

    Giuseppe A. Zito

    2013-01-01

    Full Text Available A planar-spiral antenna to be used in an ultrawideband (UWB radar system for heart activity monitoring is presented. The antenna, named “twin,” is constituted by two spiral dipoles in a compact structure. The reflection coefficient at the feed point of the dipoles is lower than −8 dB over the 3–12 GHz band, while the two-dipoles coupling is about −20 dB. The radiated beam is perpendicular to the plane of the spiral, so the antenna is wearable and it may be an optimal radiator for a medical UWB radar for heart rate detection. The designed antenna has been also used to check some hypotheses about the UWB radar heart activity detection mechanism. The radiation impedance variation, caused by the thorax vibrations associated with heart activity, seems to be the most likely explanation of the UWB radar operation.

  7. The scientific objectives of the SPIRAL 2 Project

    International Nuclear Information System (INIS)

    Ackermann, D.; Adoui, L.; Angelis, G. de

    2006-06-01

    The construction of SPIRAL 2 at GANIL will open completely new possibilities for parallel beam operation of the whole facility. The whole GANIL/SPIRAL/SPIRAL2 accelerator complex will allow for the simultaneous use of up to 5 different radioactive and stable beams. Several combinations of different beams delivered in parallel for experiments at low (keV/u), medium (few MeV/u) and high (up to 100 MeV/u) energies will be possible. Presently the GANIL/SPIRAL facility delivers about 60 weeks per year of stable and radioactive beams (up to 3 simultaneous beams). Thanks to SPIRAL 2 and the construction of a new beam line connecting the CIME cyclotron and the G1 and G2 experimental rooms the available beam time for experiments may be extended up to about 120 (up to 5 simultaneous beams) weeks per year. The chapters which follow a general introduction deal with the detailed questions to be addressed by experiments with the beams from SPIRAL2. In chapter 2 the many unanswered questions related to the structure of exotic nuclei are posed and the role of SPIRAL2 in answering them outlined. Chapter 3 deals with the dynamics and thermodynamics of asymmetric nuclear systems. Chapter 4 is concerned with questions of nuclear astrophysics which are intimately related to the properties of exotic nuclei. Chapter 5 indicates how the atomic nucleus can act as a laboratory for tests of the Standard model of Particle Physics and Chapter 6 shows how the production of intense fluxes of neutrons at SPIRAL2 make it an excellent tool to address both questions related to damage in materials of importance in nuclear installations and to the s- and r-processes of nucleosynthesis. In chapter 7 we turn to the application, of the radioactive beams from SPIRAL2 and the radionuclides produced by it, to study condensed matter and radiobiology. Finally in the eight and last chapter the reader can find an account of the historical development of the SPIRAL2 facility and this is followed by an outline of

  8. The scientific objectives of the SPIRAL 2 Project

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, D.; Adoui, L.; Angelis, G. de [GANIL, Grand Accelerateur National d' Ions Lourds, BP 55027, 14076 Caen cedex 5 (France)] (and others)

    2006-06-15

    The construction of SPIRAL 2 at GANIL will open completely new possibilities for parallel beam operation of the whole facility. The whole GANIL/SPIRAL/SPIRAL2 accelerator complex will allow for the simultaneous use of up to 5 different radioactive and stable beams. Several combinations of different beams delivered in parallel for experiments at low (keV/u), medium (few MeV/u) and high (up to 100 MeV/u) energies will be possible. Presently the GANIL/SPIRAL facility delivers about 60 weeks per year of stable and radioactive beams (up to 3 simultaneous beams). Thanks to SPIRAL 2 and the construction of a new beam line connecting the CIME cyclotron and the G1 and G2 experimental rooms the available beam time for experiments may be extended up to about 120 (up to 5 simultaneous beams) weeks per year. The chapters which follow a general introduction deal with the detailed questions to be addressed by experiments with the beams from SPIRAL2. In chapter 2 the many unanswered questions related to the structure of exotic nuclei are posed and the role of SPIRAL2 in answering them outlined. Chapter 3 deals with the dynamics and thermodynamics of asymmetric nuclear systems. Chapter 4 is concerned with questions of nuclear astrophysics which are intimately related to the properties of exotic nuclei. Chapter 5 indicates how the atomic nucleus can act as a laboratory for tests of the Standard model of Particle Physics and Chapter 6 shows how the production of intense fluxes of neutrons at SPIRAL2 make it an excellent tool to address both questions related to damage in materials of importance in nuclear installations and to the s- and r-processes of nucleosynthesis. In chapter 7 we turn to the application, of the radioactive beams from SPIRAL2 and the radionuclides produced by it, to study condensed matter and radiobiology. Finally in the eight and last chapter the reader can find an account of the historical development of the SPIRAL2 facility and this is followed by an outline of

  9. Study on a new water purification equipment with spiral lamellas

    Science.gov (United States)

    Feng, X. R.

    2017-08-01

    A new water purification equipment was introduced, especially the section of spiral lamellas. Utilization of spiral lamellas made the sedimentation space reach to 100%, not only improving sedimentation efficiency and reducing the cover space, but also saving investment. Production test results showed that the new water purification equipment with spiral lamellas had characteristics of excellent treatment efficiency and high shock resistant capacity. As the treatment water volume was 240 m3/d, when the turbidity, CODMn and UV254 were 203 NTU, 1.90 mg/L and 0.030 cm-1 in raw water, they were 0.32 NTU, 0.72mg/L and 0.011 cm-1 respectively in effluent water, which could fully meet the drinking water hygiene requirement.

  10. A Spiral And Discipline-Oriented Curriculum In Medical Imaging

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Hanson, Lars G.; Henneberg, Kaj-Åge

    2011-01-01

    This contribution describes and evaluates an experimental combination of a spiral and discipline-oriented curriculum implemented in the bachelor’s and master’s program in Medicine and Technology. The implementation in the master’s program is in the form of a study line in Medical Imaging and Radi......This contribution describes and evaluates an experimental combination of a spiral and discipline-oriented curriculum implemented in the bachelor’s and master’s program in Medicine and Technology. The implementation in the master’s program is in the form of a study line in Medical Imaging...... and Radiation Physics containing three disciplines: Imaging modalities, Radiation therapy and Image processing. The two imaging courses in the bachelor’s program and the first imaging course in the master’s program follow a spiral curriculum in which most disciplines are encountered in all courses...

  11. Auditory Mechanics of the Tectorial Membrane and the Cochlear Spiral

    Science.gov (United States)

    Gavara, Núria; Manoussaki, Daphne; Chadwick, Richard S.

    2012-01-01

    Purpose of review This review is timely and relevant since new experimental and theoretical findings suggest that cochlear mechanics from the nanoscale to the macroscale are affected by mechanical properties of the tectorial membrane and the spiral shape. Recent findings Main tectorial membrane themes covered are i) composition and morphology, ii) nanoscale mechanical interactions with the outer hair cell bundle, iii) macroscale longitudinal coupling, iv) fluid interaction with inner hair cell bundles, v) macroscale dynamics and waves. Main cochlear spiral themes are macroscale low-frequency energy focusing and microscale organ of Corti shear gain. Implications Findings from new experimental and theoretical models reveal exquisite sensitivity of cochlear mechanical performance to tectorial membrane structural organization, mechanics, and its positioning with respect to hair bundles. The cochlear spiral geometry is a major determinant of low frequency hearing. Suggestions are made for future research directions. PMID:21785353

  12. Spiral CT for cervical lymph node enlargement. Early clinical results

    International Nuclear Information System (INIS)

    Steinkamp, H.J.; Keske, U.; Schedel, J.; Hosten, N.; Felix, R.

    1994-01-01

    Spiral CT was performed before treatment in 35 patients with suspected cervical lymph node enlargement. By coronary and sagittal reconstruction it is possible to utilise the M/Q quotient which has become accepted as the result of sonographic and MRI examinations. It is now possible to obtain high diagnostic accuracy (97%) for distinguishing between reactive change from metastatic infiltration of lymph nodes (>8 mm) by using CT. Using spiral CT with 5 mm table movement, three patients diagnosed as stage N1 by axial CT were shown to be N2b. This represents a highly sensitive and highly specific method of lymph node diagnosis. Further diagnostic improvement derives from the ability to relate the lymph nodes to surrounding tissues. Spiral CT is also suitable for defining other space occupying lesions, e.g., the exact extent of retropharyngeal abscesses, abnormalities of the salivary glands or laryngocoeles. (orig.)

  13. Gastrostomy feeding tube - pump - child

    Science.gov (United States)

    ... tube feeding; PEG tube care; Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Gather supplies: Feeding pump (electronic or battery powered) Feeding ... pump (includes a feeding bag, drip chamber, roller clamp, ...

  14. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... search for current job openings visit HHS USAJobs Home >> NEI YouTube Videos >> NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract ...

  15. Rediscovering the Giant Low Surface Brightness Spiral Galaxy Malin 1

    Science.gov (United States)

    Galaz, Gaspar

    2018-01-01

    I summarize the latest discoveries regarding this ramarkable diffuse and giant galaxy, the largest single spiral in the universe so far. I describe how the latest discoveries could have been done easily 20 years ago, but an incredible summation of facts and some astronomical sociology, keeped many of them undisclosed. I present the most conspicuous features of the giant spiral arms of Malin 1, including stellar density, colors, stellar populations and some modeling describing their past evolution to the current state. I conclude with pending issues regarding stellar formation in Malin 1, and the efforts to detect its elusive molecular gas.

  16. Initial clinical experience with spiral CT angiography in the abdomen

    International Nuclear Information System (INIS)

    Gaa, J.; Stehling, M.K.; Costello, P.

    1993-01-01

    The latest developments in modern CT instruments, offering scanning times of a second, opened up new possibilities in CT imaging in combination with the spiral technique. The data set normally taken with single-breath-hold technique is free of respiratory artefacts and thus is a good basis for accurate 3D image reconstruction. Spiral CTA allows a non-invasive 3D imaging of various blood vessels. Patients with abdominal aortic aneurysms of aorto-iliac bypass can be examined as outpatients within 15 minutes. (orig.) [de

  17. The color gradient in spiral galaxies: application to M 81

    International Nuclear Information System (INIS)

    Segalovitz, A.

    1975-01-01

    The calculated development of the color of a star cluster is used to predict the expected color evolution, as a function of radius, in a spiral galaxy. It is assumed that the fraction of gas which is converted into stars during a spiral arm passage is a function of radius only. Applying this model to M 81, it is shown that the observed color and mass distributions can be explained by an initial disk-like gas distribution proportional to the inverse square of the radius and a consumption fraction which is an increasing function of radius. (orig.) [de

  18. Spiral CT angiography of the abdominal aorta and its branches

    Energy Technology Data Exchange (ETDEWEB)

    Costello, P. [Dept. of Radiology, Deaconess Hospital and Harvard Medical School, Boston, MA (United States); Gaa, J. [Dept. of Radiology, Deaconess Hospital and Harvard Medical School, Boston, MA (United States)

    1993-08-01

    Spiral CT angiography (CTA) was performed on 19 patients for the pre-operative assessment of abdominal aortic aneurysms and in 3 post-operative renal artery bypass patients. Spiral CTA performed during intravenous contrast infusion provided a volume of data that was reconstructed at thin increments. Images were edited and reformatted either as surface rendered three-dimensional or maximum intensity projection (MIP) displays. Final images were viewed in a cine-loop presentation of quality comparable to conventional angiograms. The entire aorta can be examined from the coeliac axis to mid-pelvis with only 107 ml of 60% contrast. (orig.)

  19. SPIRAL2 Week 2011 - Slides of the presentations

    International Nuclear Information System (INIS)

    Gales, S.; Jacquemet, M.; Lewitowicz, M.; Petit, E.; Biarrote, J.L.; Uriot, D.; Thuillier, T.; Peaucelle, C.; Barue, C.; Van Hille, C.; Bernaudin, P.E.; Galdemard, P.; Ausset, P.; Dolegieviez, P.; Levallois, R.; Marchetto, M.; Pasini, M.; Quiclet, M.; Danna, O.; Lunney, D.; Di Giacomo, M.

    2013-01-01

    The main goal of the meeting is to present and discuss the current status of the SPIRAL2 project at GANIL in front of a large community of scientists and engineers. The program of the meeting will include presentations on scientific and technical developments related to the baseline project, experiments and theory. The main topics to be discussed at the conference have been: -) Driver Accelerators, -) Production of radioactive ion beams (RIB), -) Safety, -) RIB Facilities Worldwide (FAIR, Riken Nishina Center, SPES project, FRIB project) -) FP7 SPIRAL2 Preparatory Phase, -) Experiments with RIB and Theory. This document is made up of the slides of the presentations

  20. Necessity for High Accuracy Rotation Curves in Spiral Galaxies

    OpenAIRE

    Blais-Ouellette, Sebastien; Carignan, Claude; Amram, Philippe

    1998-01-01

    In the last 20 years, rotation curves derived from H I kinematics obtained on radio synthesis instruments were used to probe the dark matter distribution in spiral and dwarf irregular galaxies. It is shown, with the aid of the Sd galaxy NGC 5585, that high resolution 2--D H II kinematics is necessary to determine accurately the mass distribution of spirals. New CFHT Fabry--Perot Hff observations are combined with low resolution Westerbork H I data to study its mass distribution. Using the com...

  1. A Spiral And Discipline-Oriented Curriculum In Medical Imaging

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Hanson, Lars G.; Henneberg, Kaj-Åge

    2011-01-01

    This contribution describes and evaluates an experimental combination of a spiral and discipline-oriented curriculum implemented in the bachelor’s and master’s program in Medicine and Technology. The implementation in the master’s program is in the form of a study line in Medical Imaging...... and Radiation Physics containing three disciplines: Imaging modalities, Radiation therapy and Image processing. The two imaging courses in the bachelor’s program and the first imaging course in the master’s program follow a spiral curriculum in which most disciplines are encountered in all courses...

  2. Resonant fields created by spiral electric currents in Tokamaks

    International Nuclear Information System (INIS)

    Fernandes, A.S.; Caldas, I.L.

    1985-01-01

    The influence of the resonant magnetic perturbations, created by electric currents in spirals, on the plasma confinement in a tokamak with circular section and large aspect ratio is investigated. These perturbations create magnetic islands around the rational magnetic surface which has the helicity of the helicoidal currents. The intensities of these currents are calculated in order to the magnetic islands reach the limiter or others rational surfaces, what could provoke the plasma disrupture. The electric current intensities are estimated, in two spiral sets with different helicities, which create a predominantly stocastic region among the rational magnetic surfaces with these helicities. (L.C.) [pt

  3. Origin choice and petal loss in the flower garden of spiral wave tip trajectories.

    Science.gov (United States)

    Gray, Richard A; Wikswo, John P; Otani, Niels F

    2009-09-01

    Rotating spiral waves have been observed in numerous biological and physical systems. These spiral waves can be stationary, meander, or even degenerate into multiple unstable rotating waves. The spatiotemporal behavior of spiral waves has been extensively quantified by tracking spiral wave tip trajectories. However, the precise methodology of identifying the spiral wave tip and its influence on the specific patterns of behavior remains a largely unexplored topic of research. Here we use a two-state variable FitzHugh-Nagumo model to simulate stationary and meandering spiral waves and examine the spatiotemporal representation of the system's state variables in both the real (i.e., physical) and state spaces. We show that mapping between these two spaces provides a method to demarcate the spiral wave tip as the center of rotation of the solution to the underlying nonlinear partial differential equations. This approach leads to the simplest tip trajectories by eliminating portions resulting from the rotational component of the spiral wave.

  4. Classifying and modelling spiral structures in hydrodynamic simulations of astrophysical discs

    Science.gov (United States)

    Forgan, D. H.; Ramón-Fox, F. G.; Bonnell, I. A.

    2018-05-01

    We demonstrate numerical techniques for automatic identification of individual spiral arms in hydrodynamic simulations of astrophysical discs. Building on our earlier work, which used tensor classification to identify regions that were `spiral-like', we can now obtain fits to spirals for individual arm elements. We show this process can even detect spirals in relatively flocculent spiral patterns, but the resulting fits to logarithmic `grand-design' spirals are less robust. Our methods not only permit the estimation of pitch angles, but also direct measurements of the spiral arm width and pattern speed. In principle, our techniques will allow the tracking of material as it passes through an arm. Our demonstration uses smoothed particle hydrodynamics simulations, but we stress that the method is suitable for any finite-element hydrodynamics system. We anticipate our techniques will be essential to studies of star formation in disc galaxies, and attempts to find the origin of recently observed spiral structure in protostellar discs.

  5. Categorising YouTube

    Directory of Open Access Journals (Sweden)

    Thomas Mosebo Simonsen

    2011-09-01

    Full Text Available This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC of YouTube. The article investigates the construction of navigationprocesses on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC within the interacting relationship of new and old genres are discussed. It is argued that the utility of a conventional categorical system is primarily of analytical and theoretical interest rather than as a practical instrument.

  6. Orientation of spiral galaxies in the local supercluster

    International Nuclear Information System (INIS)

    Jaaniste, J.A.; Saar, E.M.

    1977-01-01

    Two alternative models for the spatial orientation of galaxies - parallelism and perpendicularity of the planes of galaxies with respect to the supergalactic plane - are compared with the observed orientations of spiral galaxies within the volume of the radius of 50 Mpc. The first model does not agree with experimental data whereas the second one-perpendicularity of the planes - describes the above data well

  7. EM-wave absorption properties of hollow spiral iron particles

    International Nuclear Information System (INIS)

    Zhang, Wenqiang; Zhang, Deyuan

    2015-01-01

    Hollow iron spiral particles were fabricated successfully by thermal decomposition method, and they were heat-treated at different temperatures in N 2 atmosphere. The electromagnetic wave absorption properties of hollow iron spiral particles were investigated ranging between 1 GHz and 18 GHz. The results indicated that the phase structures of the particles changed from amorphous to nanocrystal with the treating temperature rising, also causing the significant change in electromagnetic parameters and the reflection loss. The reflection loss could reach −33 dB at 16.2 GHz, indicating that the hollow iron spiral particles had the potential to be used in prepare the a high property EM-wave absorber. - Highlights: • Hollow iron spiral particles were fabricated by thermal decomposition method. • The particles changed from amorphous to nanocrystals with heat-treatment. • Particles’ EM-parameters have a great change after high temperature heat-treatment. • RL results show the particles have potential to be high property EM-wave absorber

  8. The thickness of the HI gas layer in spiral galaxies

    NARCIS (Netherlands)

    Sicking, Floris Jan

    1997-01-01

    In the present study, in two inclined spiral galaxies, NGC 3198 and NGC 2403, the HI random velocity dispersion and layer thickness will be measured simultaneously. This will be done from the HI velocity dispersion field (the distribution on the sky of the observed HI line of sight velocity

  9. Teaching about Energy Through a Spiral Curriculum: Guiding Principles.

    Science.gov (United States)

    Trumper, Ricardo

    1996-01-01

    Conventional science instruction often fails to address or change students' misconceptions about physical phenomena. Students stubbornly cling to anthropocentric, causal, and product conceptions about energy. This article explores scientific and pedagogical arguments favoring development of a spiral curriculum for teaching energy in (Israeli)…

  10. Ultra wideband coplanar waveguide fed spiral antenna for humanitarian demining

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne; Appel-Hansen, Jørgen

    2000-01-01

    to 1 bandwidth with a return loss better than 10 dB from 0.4 to 3.8 GHz is presented. A wideband balun covering the frequency range of the antenna was developed. The constructed spiral antenna is very useful in a stepped frequency ground penetrating radar for humanitarian demining due to the very...

  11. Multivessel myocardial bridging in a patient with spiral hypertrophic cardiomyopathy

    OpenAIRE

    Fritz, Timothy; Abdallah, Wissam; McNamara, Richard

    2016-01-01

    Myocardial bridging is commonly observed in hypertrophic cardiomyopathy, usually confined to the left anterior descending (LAD), and correlates to the hypertrophic septum. We present a patient with unique spiral hypertrophic cardiomyopathy (HCM) and compression of all three coronary arteries corresponding to this hypertrophy pattern.

  12. Spiral intensity patterns in the internally pumped optical parametric oscillator

    DEFF Research Database (Denmark)

    Lodahl, Peter; Bache, Morten; Saffman, Mark

    2001-01-01

    We describe a nonlinear optical system that supports spiral pattern solutions in the field intensity. This new spatial structure is found to bifurcate above a secondary instability in the internally pumped optical parametric oscillator. The analytical predictions of threshold and spatial scale...

  13. Abundance analysis of giant H II regions in nearby spirals

    OpenAIRE

    Díaz, Angeles I.; Terlevich, E.; Pagel, B.E.J.; Vílchez, J.M; Edmunds, M.G.

    1990-01-01

    This is an electronic version of an article published in Revista Mexicana de Astronomía y Astrofísica. Díaz, Angeles I. et al. Abundance analysis of giant H II regions in nearby spirals. Revista Mexicana de Astronomía y Astrofísica 21 (1990): 223-227

  14. A Spiral And Discipline-Oriented Curriculum In Medical Imaging

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Hanson, Lars G.; Henneberg, Kaj-Åge

    2011-01-01

    . However, in the master’s program, such a tight schedule is impractical since students are likely to seek specialization. From a pedagogical point of view, the spiral curriculum is advantageous to use in the initial semesters where the teaching can be conducted so that the students can build...

  15. A combined optical, SEM and STM study of growth spirals

    Indian Academy of Sciences (India)

    Some novel results of a combined sequential study of growth spirals on the basal surface of the richly polytypic CdI2 crystals by optical microscopy, scanning electron microscopy (SEM) and scanning tunneling microscopy (STM) are presented and discussed. In confirmation of the known structural data, the STM pictures ...

  16. Learning in 3D Virtual Environments: Collaboration and Knowledge Spirals

    Science.gov (United States)

    Burton, Brian G.; Martin, Barbara N.

    2010-01-01

    The purpose of this case study was to determine if learning occurred within a 3D virtual learning environment by determining if elements of collaboration and Nonaka and Takeuchi's (1995) knowledge spiral were present. A key portion of this research was the creation of a Virtual Learning Environment. This 3D VLE utilized the Torque Game Engine…

  17. Long term complications of the intraprostatic spiral. Case report

    DEFF Research Database (Denmark)

    Krogh, J

    1992-01-01

    A 76-year-old man had an intraprostatic spiral inserted to relieve bladder outlet obstruction that was caused by benign prostatic hypertrophy. After 30 months numerous complications had arisen including severe encrustations, urethral stricture, and sclerosis of the bladder neck. Regular replaceme...

  18. Advanced Manufacture of Spiral Bevel and Hypoid Gears

    Directory of Open Access Journals (Sweden)

    Vilmos Simon

    2016-11-01

    Full Text Available In this study, an advanced method for the manufacture of spiral bevel and hypoid gears on CNC hypoid generators is proposed. The optmal head-cutter geometry and machine tool settings are determined to introduce the optimal tooth surface modifications into the teeth of spiral bevel and hypoid gears. The aim of these tooth surface modifications is to simultaneously reduce the tooth contact pressure and the transmission errors, to maximize the EHD load carrying capacity of the oil film, and to minimize power losses in the oil film. The proposed advanced method for the manufacture of spiral bevel and hypoid gears is based on machine tool setting variation on the cradle-type generator conducted by optimal polynomial functions and on the use of a CNC hypoid generator. An algorithm is developed for the execution of motions on the CNC hypoid generator using the optimal relations on the cradle-type machine. Effectiveness of the method was demonstrated by using spiral bevel and hypoid gear examples. Significant improvements in the operating characteristics of the gear pairs are achieved.

  19. Long term complications of the intraprostatic spiral. Case report

    DEFF Research Database (Denmark)

    Krogh, J

    1992-01-01

    A 76-year-old man had an intraprostatic spiral inserted to relieve bladder outlet obstruction that was caused by benign prostatic hypertrophy. After 30 months numerous complications had arisen including severe encrustations, urethral stricture, and sclerosis of the bladder neck. Regular replacement...

  20. Multiferroic Magnetic Spirals Induced by Random Magnetic Exchanges

    Science.gov (United States)

    Scaramucci, Andrea; Shinaoka, Hiroshi; Mostovoy, Maxim V.; Müller, Markus; Mudry, Christopher; Troyer, Matthias; Spaldin, Nicola A.

    2018-01-01

    Multiferroism can originate from the breaking of inversion symmetry caused by magnetic-spiral order. The usual mechanism for stabilizing a magnetic spiral is competition between magnetic exchange interactions differing by their range and sign, such as nearest-neighbor and next-nearest-neighbor interactions. In insulating compounds, it is unusual for these interactions to be both comparable in magnitude and of a strength that can induce magnetic ordering at room temperature. Therefore, the onset temperatures for multiferroism through this mechanism are typically low. By considering a realistic model for multiferroic YBaCuFeO5 , we propose an alternative mechanism for magnetic-spiral order, and hence for multiferroism, that occurs at much higher temperatures. We show, using Monte Carlo simulations and electronic structure calculations based on density functional theory, that the Heisenberg model on a geometrically nonfrustrated lattice with only nearest-neighbor interactions can have a spiral phase up to high temperature when frustrating bonds are introduced randomly along a single crystallographic direction as caused, e.g., by a particular type of chemical disorder. This long-range correlated pattern of frustration avoids ferroelectrically inactive spin-glass order. Finally, we provide an intuitive explanation for this mechanism and discuss its generalization to other materials.

  1. Embedded spiral patterns in the massive galaxy cluster Abell 1835

    Science.gov (United States)

    Ueda, S.; Kitayama, T.; Dotani, T.

    2017-10-01

    We report on the properties of the intracluster medium (ICM) in the central region of the massive galaxy cluster, Abell 1835, obtained with the data from the Chandra X-ray Observatory. We find distinctive spiral patterns in the cool core in the residual image of the X-ray surface brightness after its nominal profile is subtracted. The spiral patterns consist of two arms. One of them appears as positive, and the other appears as negative excesses in the residual image. Their sizes are ˜ 70 kpc and their morphologies are consistent with each other. We find that the spiral patterns extend from the cool core out to the hotter surrounding ICM. We analyze the X-ray spectra extracted from both regions. We obtain that the ICM properties are similar to those expected by gas sloshing. We also find that the ICM in the two regions of spiral patterns is near or is in pressure equilibrium. Abell 1835 may now be experiencing gas sloshing induced by an off-axis minor merger. These results have been already published (Ueda, Kitayama, & Dotani 2017, ApJ, 837, 34).

  2. The Neutrons for Science Facility at SPIRAL-2

    Czech Academy of Sciences Publication Activity Database

    Ledoux, X.; Avrigeanu, M.; Avrigeanu, V.; Bém, Pavel; Fischer, U.; Majerle, Mitja; Mrázek, Jaromír; Negoita, F.; Novák, Jan; Simakov, S. P.; Šimečková, Eva

    2014-01-01

    Roč. 119, MAY (2014), s. 353-356 ISSN 0090-3752 Institutional support: RVO:61389005 Keywords : SPIRAL-2 * Neutron For Science * time-of-flight Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.571, year: 2014

  3. The dynamics of the spiral structure in galaxies

    International Nuclear Information System (INIS)

    Contopoulos, G.

    1979-01-01

    The basic ideas and current problems of the linear and non-linear theory of spiral structure are reviewed. Some recent work on the response density and possible self-consistent solutions of bars with an Inner Lindblad Resonance are described. (Auth.)

  4. Opaque spiral disks - Some empirical facts and consequences

    NARCIS (Netherlands)

    Valentijn, Edwin A.

    1990-01-01

    Results for the Sb and Sc galaxies, as obtained from the analysis of the optical ESO-LV data, are reviewed, and the implied constraints for the properties of the absorbing components in spiral disks are discussed. An alternative interpretation of flat rotation curves and a revised extinction model

  5. SPIRAL (Sandia's Program for Information Retrieval and Listing)

    Science.gov (United States)

    West, Leslie E.

    The general scope of SPIRAL is storage of free-flowing text information into a machine-readable library and recall of any portions of this stored information that are relevant to an inquiry. The major objectives in the design of the system were (1) to make it easy to use by persons unfamiliar with computer systems; and (2) to make it efficient, in…

  6. Ekman Spiral in Horizontally Inhomogeneous Ocean with Varying Eddy Viscosity

    Science.gov (United States)

    2015-01-01

    thermocline (in temperature) and pycnocline (in density) (e.g., Kraus and Turner 1967; Garwood 1977; Chu and Garwood 1991; Steger et al. 1998; Chu et...spiral as a good statistical fit to low-frequency currents in a coastal strait. Science, 233, 470-472. Steger , J., Collins, C.A., and Chu, P.C. (1998

  7. THE MASS-DISTRIBUTION OF THE DWARF SPIRAL NGC-1560

    NARCIS (Netherlands)

    BROEILS, AH

    H I synthesis observations with the WSRT and optical surface photometry of the dwarf spiral galaxy NGC 1560 are presented. This galaxy has an absolute luminosity of M(B) = -15.87. The observations show that the galaxy is gas rich, with an M(HI)/L(B) of 2.4. We obtained a very detailed rotation curve

  8. Evaluation of spiral CT in the diagnosis of ureteral diseases

    International Nuclear Information System (INIS)

    Li Jiansheng; Li Kangyin; Chen Huyi; Qiang Haixia; Shen Guoqiang; Li Jing

    2001-01-01

    Objective: To discuss the diagnostic value of spiral CT in ureteral diseases. Methods: Spiral CT urography (SCTU) was performed in 27 cases with ureteral diseases, including 9 cases of ureteral calculus, 5 carcinomas, 9 stenosis, 1 malformation, 1 inflammation and 2 fistula. Of the 27 cases,15 also underwent non-enhanced spiral CT scan and 10 received intravenous urography(IVU). Results: (1) Eight cases of radiolucent ureteral calculus were clearly showed by non-enhanced spiral CT. (2) On SCTU, the location and diameter of 9 ureteral calculus (8 radiolucent, 1 radiopaque) and enlargement of renal pelvis and ureter were displayed. Irregular ureteral wall, local rarefaction or obstruction of contrast medium in ureter were detected in 5 case of tumor. Ureteral lumen was narrowed gradually in 7 cases of simple ureteral stenosis without thickening of the wall. Two cases with ectopic vessel compression were clarified at the boundary of ureter and pelvis. 1 malformation with double renal pelvis and ureter was demonstrated. The location and direction of ureteral fistula were notified. Conclusion: SCTU is superior to IVU and conventional CT in improving diagnostic accuracy of ureteral disease

  9. Intervention of malignant biliary obstruction with Hanaro spiral stent

    International Nuclear Information System (INIS)

    Shin, Sung Wook; Choo, Sung Wook; Pyeun, Yong Seon and others

    1999-01-01

    To evaluate the long-term patency of the Hanaro spiral stent (Solco Intermed, Seoul, Korea) when used as a palliative in patients with inoperable malignant biliary obstruction. Between April 1996 and July 1998, 39 patients with malignant biliary obstruction underwent percutaneous placement of 48 Hanaro spiral stents. The causes of obstruction were bile duct carcinoma (n=18), pancreatic carcinoma (n=8), metastatic lymphadenopathy (n=5), gallbladder carcinoma (n=5), hepatocellular carcinoma (n=1) and other tumors (n=2). Using the kaplan-Meier method, patient survival and stet patency rates were estimated with regard to level of obstruction. As regards stent insertion, there was no technical failure. Overall 25- and 50-week survival rates for the entire patient group were 50 % and 11 %, respectively, while overall stent patency rates at 25 and 50 weeks were 42 % and 11 %, respectively. Twenty-five-week stent patency rates in patients with common bile duct (CBD) and hilar obstruction were 51 % and 18 %, respectively. The stent patency rates in the CBD obstruction group was significantly higher than that in the hilar obstruction group (p<0.05). In patients with CBD obstruction, the clinical efficacy of Hanaro spiral stent was superior to that in patients with hilar obstruction. However, Hanaro spiral stents showed a lower patency rate with regard to patient survival, and further investigation is required

  10. Flux flow and cleaning enhancement in a spiral membrane element ...

    African Journals Online (AJOL)

    The effect of backpulsing, into the permeate space of a 2.5 inch spiral wrap membrane, on the prevention of fouling (flux enhancement) was investigated experimentally. These experiments were performed using a 500 mg∙ℓ-1 dextrin solution and a 100 000 MCWO polypropylene membrane, with a feed pressure of 100 kPa ...

  11. Dark matter and rotation curves of spiral galaxies

    Czech Academy of Sciences Publication Activity Database

    Křížek, Michal; Křížek, Filip; Somer, L.

    2016-01-01

    Roč. 25, April (2016), s. 64-77 ISSN 1313-2709 R&D Projects: GA MŠk(CZ) LG15052 Institutional support: RVO:67985840 ; RVO:61389005 Keywords : red dwarf * dark matter * spiral galaxy Subject RIV: BA - General Mathematics http://www.astro.bas.bg/AIJ/issues/n25/MKrizek.pdf

  12. Exact cone beam CT with a spiral scan

    International Nuclear Information System (INIS)

    Tam, K.C.; Samarasekera, S.; Sauer, F.

    1998-01-01

    A method is developed which makes it possible to scan and reconstruct an object with cone beam x-rays in a spiral scan path with area detectors much shorter than the length of the object. The method is mathematically exact. If only a region of interest of the object is to be imaged, a top circle scan at the top level of the region of interest and a bottom circle scan at the bottom level of the region of interest are added. The height of the detector is required to cover only the distance between adjacent turns in the spiral projected at the detector. To reconstruct the object, the Radon transform for each plane intersecting the object is computed from the totality of the cone beam data. This is achieved by suitably combining the cone beam data taken at different source positions on the scan path; the angular range of the cone beam data required at each source position can be determined easily with a mask which is the spiral scan path projected on the detector from the current source position. The spiral scan algorithm has been successfully validated with simulated cone beam data. (author)

  13. Fill tube fitted spheres

    International Nuclear Information System (INIS)

    Ives, B.H.

    1981-01-01

    The high temperature diffusion technique for fuel filling of some future direct drive cryogenic ICF targets may be unacceptable. The following describes a technique of fitting a 1 mm diameter x 6 μm thick glass microsphere with an approx. 50 μm O.D. glass fill tube. The process of laser drilling a 50 μm diameter hole in the microsphere wall, technique for making the epoxy joint between the sphere and fill tube, as well as the assembly procedure are also discussed

  14. Steam generator tube vibration study

    International Nuclear Information System (INIS)

    Enderlin, W.I.

    1986-01-01

    Chemical cleaning has been proposed to remove magnetite buildup in some pressurized water reactor steam generators. The US Nuclear Regulatory Commission (NRC) has expressed concern that such cleaning would combine with the tube denting caused by magnetite formation to enlarge tube/tube support plate clearances, increasing the level of flow-induced vibrations that could lead to unacceptably high tube wear and failure rates. In support of NRC, the Pacific Northwest Laboratory investigated whether such increased clearances would exacerbate tube fretting wear. Using a full-length scale model of a steam generator tube bundle, flow tests were conducted at an instrumented location through clearances representing as-built and post-cleaned tube conditions. Test results indicated little potential for increased tube wear as a result of chemical cleaning, under normal operating conditions at tube support locations similar to that tested

  15. Model for Simulating a Spiral Software-Development Process

    Science.gov (United States)

    Mizell, Carolyn; Curley, Charles; Nayak, Umanath

    2010-01-01

    A discrete-event simulation model, and a computer program that implements the model, have been developed as means of analyzing a spiral software-development process. This model can be tailored to specific development environments for use by software project managers in making quantitative cases for deciding among different software-development processes, courses of action, and cost estimates. A spiral process can be contrasted with a waterfall process, which is a traditional process that consists of a sequence of activities that include analysis of requirements, design, coding, testing, and support. A spiral process is an iterative process that can be regarded as a repeating modified waterfall process. Each iteration includes assessment of risk, analysis of requirements, design, coding, testing, delivery, and evaluation. A key difference between a spiral and a waterfall process is that a spiral process can accommodate changes in requirements at each iteration, whereas in a waterfall process, requirements are considered to be fixed from the beginning and, therefore, a waterfall process is not flexible enough for some projects, especially those in which requirements are not known at the beginning or may change during development. For a given project, a spiral process may cost more and take more time than does a waterfall process, but may better satisfy a customer's expectations and needs. Models for simulating various waterfall processes have been developed previously, but until now, there have been no models for simulating spiral processes. The present spiral-process-simulating model and the software that implements it were developed by extending a discrete-event simulation process model of the IEEE 12207 Software Development Process, which was built using commercially available software known as the Process Analysis Tradeoff Tool (PATT). Typical inputs to PATT models include industry-average values of product size (expressed as number of lines of code

  16. Evolution of Gas Across Spiral Arms in the Whirlpool Galaxy

    Science.gov (United States)

    Louie, Melissa Nicole

    To investigate the dynamic evolution of gas across spiral arms, we conducted a detailed study of the gas and star formation along the spiral arms in the Whirlpool Galaxy, M51. This nearby, face-on spiral galaxy provides a unique laboratory to study the relationship between gas dynamics and star formation. The textbook picture of interstellar medium (ISM) evolution is rapidly changing. Molecular gas was once believed to form along spiral arms from the diffuse atomic gas in the inter-arm regions. Star formation occurs within giant molecular clouds during spiral arm passage. Lastly, the molecular gas is photo-dissociated back into atomic gas by massive stars on the downstream side of the spiral arm. Recent evidence, however, is revealing a new picture of the interstellar medium and the process of star formation. We seek development of a new picture by studying the development and evolution of molecular gas and the role of large scale galactic dynamics in organizing the interstellar medium. This thesis begins by presenting work measuring the geometrical offsets between interstellar gas and recent star formation. Interstellar gas is traced by atomic hydrogen and carbon monoxide (CO). Star formation is traced by ionized hydrogen recombination lines and infrared emission from dust warmed by young bright stars. Measuring these offsets can help determine the underlying large scale galactic dynamics. Along the spiral arms in M51, offsets between CO and the star formation tracers suggest that gas is flowing through the spiral arms, but the offsets do not show the expected signature of a single pattern speed and imply a more complicated pattern. This thesis also examines the intermediate stages of gas evolution, by studying a denser component of the ISM closer to which stars will form. Only a small percent of the bulk molecular gas will become dense enough to form stars. HCN and HCO+ probe densities ˜104 cm-3, where as the bulk gas is 500 cm-3. This thesis looks at HCN and

  17. Computerized spiral analysis using the iPad.

    Science.gov (United States)

    Sisti, Jonathan A; Christophe, Brandon; Seville, Audrey Rakovich; Garton, Andrew L A; Gupta, Vivek P; Bandin, Alexander J; Yu, Qiping; Pullman, Seth L

    2017-01-01

    Digital analysis of writing and drawing has become a valuable research and clinical tool for the study of upper limb motor dysfunction in patients with essential tremor, Parkinson's disease, dystonia, and related disorders. We developed a validated method of computerized spiral analysis of hand-drawn Archimedean spirals that provides insight into movement dynamics beyond subjective visual assessment using a Wacom graphics tablet. While the Wacom tablet method provides robust data, more widely available mobile technology platforms exist. We introduce a novel adaptation of the Wacom-based method for the collection of hand-drawn kinematic data using an Apple iPad. This iPad-based system is stand-alone, easy-to-use, can capture drawing data with either a finger or capacitive stylus, is precise, and potentially ubiquitous. The iPad-based system acquires position and time data that is fully compatible with our original spiral analysis program. All of the important indices including degree of severity, speed, presence of tremor, tremor amplitude, tremor frequency, variability of pressure, and tightness are calculated from the digital spiral data, which the application is able to transmit. While the iPad method is limited by current touch screen technology, it does collect data with acceptable congruence compared to the current Wacom-based method while providing the advantages of accessibility and ease of use. The iPad is capable of capturing precise digital spiral data for analysis of motor dysfunction while also providing a convenient, easy-to-use modality in clinics and potentially at home. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Misdirected minitracheostomy tube

    Directory of Open Access Journals (Sweden)

    Ajmer Singh

    2017-01-01

    Full Text Available We report a patient who after an uneventful coronary artery bypass graft surgery and left ventricular aneurysmorrhaphy developed intracerebral hemorrhage and subsequently required minitracheostomy. Chest X-ray showed misdirected minitracheostomy tube facing upward toward the laryngeal opening which was repositioned using bronchoscope.

  19. A New Resonance Tube

    Science.gov (United States)

    Bates, Alan

    2017-01-01

    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at…

  20. Thoughts of accelerator tubes

    International Nuclear Information System (INIS)

    Larson, J.D.

    1977-01-01

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators

  1. Thoughts of accelerator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Larson, J D

    1977-01-01

    A brief, subjective review is given of mechanisms that may be limiting electrostatic accelerator tubes to present levels of performance. Suggestions are made for attacking these limitations with the purpose of stimulating the thinking of designers and users of electrostatic accelerators.

  2. Eustachian Tube Dysfunction

    Science.gov (United States)

    ... When it is inflated, the balloon opens a pathway for mucus and air to flow through the tube. This can help it function properly. FDA warning The U.S. Food and Drug Administration (FDA) advises against the use of ear candles. ...

  3. Tube-dwelling invertebrates

    NARCIS (Netherlands)

    Hölker, Franz; Vanni, Michael J.; Kuiper, Jan J.; Meile, Christof; Grossart, Hans Peter; Stief, Peter; Adrian, Rita; Lorke, Andreas; Dellwig, Olaf; Brand, Andreas; Hupfer, Michael; Mooij, Wolf M.; Nützmann, Gunnar; Lewandowski, Jörg

    2015-01-01

    There is ample evidence that tube-dwelling invertebrates such as chironomids significantly alter multiple important ecosystem functions, particularly in shallow lakes. Chironomids pump large water volumes, and associated suspended and dissolved substances, through the sediment and thereby compete

  4. Chest tube insertion

    Science.gov (United States)

    ... of your chest cavity. This is called the pleural space. It is done to allow your lungs to fully expand. ... pneumothorax ) Fluid buildup in the chest (called a pleural ... in the esophagus (the tube that allows food to go from the mouth ...

  5. Planar Task Space Control of a Biarticular Manipulator Driven by Spiral Motors

    Directory of Open Access Journals (Sweden)

    Ahmad Zaki bin Hj Shukor

    2012-10-01

    Full Text Available This paper elaborates upon a musculoskeletal-inspired robot manipulator using a prototype of the spiral motor developed in our laboratory. The spiral motors represent the antagonistic muscles due to the high forward/backward drivability without any gears or mechanisms. Modelling of the biarticular structure with spiral motor dynamics was presented and simulations were carried out to compare two control methods, Inverse Kinematics (IK and direct-Cartesian control, between monoarticular only structures and biarticular structures using the spiral motor. The results show the feasibility of the control, especially in maintaining air gaps within the spiral motor.

  6. Drift tubes of Linac 2

    CERN Multimedia

    Photographic Service

    1977-01-01

    Being redied for installation, those at the right are for tank 1, those on the left for tank 2. Contrary to Linac 1, which had drift-tubes supported on stems, here the tubes are suspended, for better mechanical stability.

  7. Rubens Flame-Tube Demonstration.

    Science.gov (United States)

    Ficken, George W.; Stephenson, Francis C.

    1979-01-01

    Investigates and explains the phenomenon associated with Rubens flame-tube demonstration, specifically the persistance of flames at regular intervals along the tube for few minutes after the gas is turned off. (GA)

  8. Prospects for stronger calandria tubes

    International Nuclear Information System (INIS)

    Ells, C.E.; Coleman, C.E.; Hosbons, R.R.; Ibrahim, E.F.; Doubt, G.L.

    1990-12-01

    The CANDU calandria tubes, made of seam welded and annealed Zircaloy-2, have given exemplary service in-reactor. Although not designed as a system pressure containment, calandria tubes may remain intact even in the face of pressure tube rupture. One such incident at Pickering Unit 2 demonstrated the economic advantage of such an outcome, and a case can be made for increasing the probability that other calandria tubes would perform in a similar fashion. Various methods of obtaining stronger calandria tubes are available, and reviewed here. When the tubes are internally pressurized, the weld is the weak section of the tube. Increasing the oxygen concentration in the starting sheet, and thickening the weld, are promising routes to a stronger tube

  9. STAR FORMATION IN PARTIALLY GAS-DEPLETED SPIRAL GALAXIES

    International Nuclear Information System (INIS)

    Rose, James A.; Miner, Jesse; Levy, Lorenza; Robertson, Paul

    2010-01-01

    Broadband B and R and Hα images have been obtained with the 4.1 m SOAR telescope atop Cerro Pachon, Chile, for 29 spiral galaxies in the Pegasus I galaxy cluster and for 18 spirals in non-cluster environments. Pegasus I is a spiral-rich cluster with a low-density intracluster medium and a low galaxy velocity dispersion. When combined with neutral hydrogen (H I) data obtained with the Arecibo 305 m radio telescope, acquired by Levy et al. (2007) and by Springob et al. (2005b), we study the star formation rates in disk galaxies as a function of their H I deficiency. To quantify H I deficiency, we use the usual logarithmic deficiency parameter, DEF. The specific star formation rate (SSFR) is quantified by the logarithmic flux ratio of Hα flux to R-band flux, and thus roughly characterizes the logarithmic SFR per unit stellar mass. We find a clear correlation between the global SFR per unit stellar mass and DEF, such that the SFR is lower in more H I-deficient galaxies. This correlation appears to extend from the most gas-rich to the most gas-poor galaxies. We also find a correlation between the central SFR per unit mass relative to the global values, in the sense that the more H I-deficient galaxies have a higher central SFR per unit mass relative to their global SFR values than do gas-rich galaxies. In fact, approximately half of the H I-depleted galaxies have highly elevated SSFRs in their central regions, indicative of a transient evolutionary state. In addition, we find a correlation between gas depletion and the size of the Hα disk (relative to the R-band disk); H I-poor galaxies have truncated disks. Moreover, aside from the elevated central SSFR in many gas-poor spirals, the SSFR is otherwise lower in the Hα disks of gas-poor galaxies than in gas-rich spirals. Thus, both disk truncation and lowered SSFR levels within the star-forming part of the disks (aside from the enhanced nuclear SSFR) correlate with H I deficiency, and both phenomena are found to

  10. Shadows and spirals in the protoplanetary disk HD 100453

    Science.gov (United States)

    Benisty, M.; Stolker, T.; Pohl, A.; de Boer, J.; Lesur, G.; Dominik, C.; Dullemond, C. P.; Langlois, M.; Min, M.; Wagner, K.; Henning, T.; Juhasz, A.; Pinilla, P.; Facchini, S.; Apai, D.; van Boekel, R.; Garufi, A.; Ginski, C.; Ménard, F.; Pinte, C.; Quanz, S. P.; Zurlo, A.; Boccaletti, A.; Bonnefoy, M.; Beuzit, J. L.; Chauvin, G.; Cudel, M.; Desidera, S.; Feldt, M.; Fontanive, C.; Gratton, R.; Kasper, M.; Lagrange, A.-M.; LeCoroller, H.; Mouillet, D.; Mesa, D.; Sissa, E.; Vigan, A.; Antichi, J.; Buey, T.; Fusco, T.; Gisler, D.; Llored, M.; Magnard, Y.; Moeller-Nilsson, O.; Pragt, J.; Roelfsema, R.; Sauvage, J.-F.; Wildi, F.

    2017-01-01

    Context. Understanding the diversity of planets requires studying the morphology and physical conditions in the protoplanetary disks in which they form. Aims: We aim to study the structure of the 10 Myr old protoplanetary disk HD 100453, to detect features that can trace disk evolution and to understand the mechanisms that drive these features. Methods: We observed HD 100453 in polarized scattered light with VLT/SPHERE at optical (0.6 μm, 0.8 μm) and near-infrared (1.2 μm) wavelengths, reaching an angular resolution of 0.02'', and an inner working angle of 0.09''. Results: We spatially resolve the disk around HD 100453, and detect polarized scattered light up to 0.42'' ( 48 au). We detect a cavity, a rim with azimuthal brightness variations at an inclination of 38° with respect to our line of sight, two shadows and two symmetric spiral arms. The spiral arms originate near the location of the shadows, close to the semi major axis. We detect a faint feature in the SW that can be interpreted as the scattering surface of the bottom side of the disk, if the disk is tidally truncated by the M-dwarf companion currently seen at a projected distance of 119 au. We construct a radiative transfer model that accounts for the main characteristics of the features with an inner and outer disk misaligned by 72°. The azimuthal brightness variations along the rim are well reproduced with the scattering phase function of the model. While spirals can be triggered by the tidal interaction with the companion, the close proximity of the spirals to the shadows suggests that the shadows could also play a role. The change in stellar illumination along the rim induces an azimuthal variation of the scale height that can contribute to the brightness variations. Conclusions: Dark regions in polarized images of transition disks are now detected in a handful of disks and often interpreted as shadows due to a misaligned inner disk. However, the origin of such a misalignment in HD 100453, and

  11. Expansion lyre-shaped tube

    International Nuclear Information System (INIS)

    Andro, Jean.

    1973-01-01

    The invention relates the expansion lyre-shaped tube portions formed in dudgeoned tubular bundles between two bottom plates. An expansion lyre comprises at least two sets of tubes of unequal lengths coplanar and symmetrical with respect to the main tube axis, with connecting portions between the tubes forming said sets. The invention applies to apparatus such as heat exchangers, heaters, superheaters or breeders [fr

  12. NEI You Tube Videos: Amblyopia

    Science.gov (United States)

    ... NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence Insufficiency Diabetic Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma Healthy Vision Tips Leber Congenital Amaurosis Low ...

  13. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract Convergence Insufficiency Diabetic Eye Disease Dilated Eye Exam Dry Eye For Kids Glaucoma Healthy Vision Tips Leber Congenital Amaurosis Low ...

  14. Neutron image intensifier tubes

    International Nuclear Information System (INIS)

    Verat, M.; Rougeot, H.; Driard, B.

    1983-01-01

    The most frequently used techniques in neutron radiography employ a neutron converter consisting of either a scintillator or a thin metal sheet. The radiation created by the neutrons exposes a photographic film that is in contact with the converter: in the direct method, the film is exposed during the time that the object is irradiated with neutrons; in the transfer method, the film is exposed after the irradiation of the object with neutrons. In industrial non-destructive testing, when many identical objects have to be checked, these techniques have several disadvantages. Non-destructive testing systems without these disadvantages can be constructed around neutron-image intensifier tubes. A description and the operating characteristics of neutron-image intensifier tubes are given. (Auth.)

  15. Neural tube defects

    Directory of Open Access Journals (Sweden)

    M.E. Marshall

    1981-09-01

    Full Text Available Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have been used to describe this defect, but spina bifida remains the most useful general term, as it describes the separation of the vertebral elements in the midline.

  16. Curvature-driven bubbles or droplets on the spiral surface

    Science.gov (United States)

    Li, Shanpeng; Liu, Jianlin; Hou, Jian

    2016-11-01

    Directional motion of droplets or bubbles can often be observed in nature and our daily life, and this phenomenon holds great potential in many engineering areas. The study shows that droplets or bubbles can be driven to migrate perpetually on some special substrates, such as the Archimedean spiral, the logarithmic spiral and a cantilever sheet in large deflection. It is found that a bubble approaches or deviates from the position with highest curvature of the substrate, when it is on the concave or convex side. This fact is helpful to explain the repelling water capability of Nepenthes alata. Based on the force and energy analysis, the mechanism of the bubble migration is well addressed. These findings pave a new way to accurately manipulate droplet or bubble movement, which bring inspirations to the design of microfluidic and water harvesting devices, as well as oil displacement and ore filtration.

  17. Synchronized control of spiral CT scan for security inspection device

    International Nuclear Information System (INIS)

    Wang Jue; Jiang Zenghui; Wang Fuquan

    2008-01-01

    In security inspection system of spiral CT, the synchronization between removing and rotating, and the scan synchronization between rotating and sampling influence quality of image reconstruction, so it is difficulty and important that how to realize synchronized scan. According to the controlling demand of multi-slice Spiral CT, the method to realize synchronized scan is given. a synchronized control system is designed, in which we use a industrial PC as the control computer, use magnetic grids as position detectors, use alternating current servo motor and roller motor as drivers respectively drive moving axis and rotating axis. This method can solve the problem of synchronized scan, and has a feasibility and value of use. (authors)

  18. Status of the SPIRAL 2 LINAC cryogenic system

    Science.gov (United States)

    Ghribi, A.; Bernaudin, P.-E.; Vassal, A.; Bonne, F.

    2017-07-01

    SPIRAL 2 is a state of the art superconducting linear accelerator expected to deliver some of the highest intensity rare isotope beams on earth. The project has been in development/design, fabrication and installation for over 10 years and is now reaching its final critical stages before commissioning. One of its most critical parts is a cryoplant and a cryodistribution system that feed the heart of the accelerator with the necessary refrigeration power and allow the required pressure and thermal regulation to be achieved and maintained in a reliable way. This paper summarises the latest updates of the cryogenic system before the first cool down trials. It also plots the strategies and R&D efforts undertaken to tackle some of the challenges that SPIRAL 2 is expected to face.

  19. Distributed temperature sensing using a SPIRAL configuration ultrasonic waveguide

    Science.gov (United States)

    Periyannan, Suresh; Balasubramaniam, Krishnan

    2017-02-01

    Distributed temperature sensing has important applications in the long term monitoring of critical enclosures such as containment vessels, flue gas stacks, furnaces, underground storage tanks and buildings for fire risk. This paper presents novel techniques for such measurements, using wire in a spiral configuration and having special embodiments such a notch for obtaining wave reflections from desired locations. Transduction is performed using commercially available Piezo-electric crystal that is bonded to one end of the waveguide. Lower order axisymmetric guided ultrasonic modes were employed. Time of fight (TOF) differences between predefined reflectors located on the waveguides are used to infer temperature profile in a chamber with different temperatures. The L(0,1) wave mode (pulse echo approach) was generated/received in a spiral waveguide at different temperatures for this work. The ultrasonic measurements were compared with commercially available thermocouples.

  20. The Norma spiral arm: large-scale pitch angle

    Science.gov (United States)

    Vallée, Jacques P.

    2017-09-01

    In the inner Galaxy, we statistically find the mean pitch angle of the recently mapped Norma arm in two galactic quadrants (observed tangentially at galactic longitudes near l=328° and near l=20°), using the twin-tangent method, and obtain -13.7°± 1.4°. We compared with other measurements in the literature. Also, using the latest published data on pitch angle and the latest published data on the radial starting point of the four arms (R_{Gal} = 2.2 kpc) in each galactic quadrant, a revised velocity plot of the Norma spiral arm is made, along with other spiral arms in the Milky Way, in each Galactic quadrant.

  1. Spiral actin-polymerization waves can generate amoeboidal cell crawling

    Energy Technology Data Exchange (ETDEWEB)

    Dreher, A.; Aranson, I. S.; Kruse, K.

    2014-05-01

    Amoeboidal cell crawling on solid substrates is characterized by protrusions that seemingly appear randomly along the cell periphery and drive the cell forward. For many cell types, it is known that the protrusions result from polymerization of the actin cytoskeleton. However, little is known about how the formation of protrusions is triggered and whether the appearance of subsequent protrusions is coordinated. Recently, the spontaneous formation of actin-polymerization waves was observed. These waves have been proposed to orchestrate the cytoskeletal dynamics during cell crawling. Here, we study the impact of cytoskeletal polymerization waves on cell migration using a phase-field approach. In addition to directionally moving cells, we find states reminiscent of amoeboidal cell crawling. In this framework, new protrusions are seen to emerge from a nucleation process, generating spiral actin waves in the cell interior. Nucleation of new spirals does not require noise, but occurs in a state that is apparently displaying spatio-temporal chaos.

  2. Heating hydrocarbon containing formations in a spiral startup staged sequence

    Science.gov (United States)

    Vinegar, Harold J [Bellaire, TX; Miller, David Scott [Katy, TX

    2009-12-15

    Methods for treating a hydrocarbon containing formation are described herein. Methods may include treating a first zone of the formation. Treatment of a plurality of zones of the formation may be begun at selected times after the treatment of the first zone begins. The treatment of at least two successively treated zones may begin at a selected time after treatment of the previous zone begins. At least two of the successively treated zones may be adjacent to the zone treated previously. The successive treatment of the zones proceeds in an outward, substantially spiral sequence from the first zone so that the treatment of the zones may move substantially spirally outwards towards a boundary of the treatment area.

  3. Chiral spiral induced by a strong magnetic field

    Directory of Open Access Journals (Sweden)

    Abuki Hiroaki

    2016-01-01

    Full Text Available We study the modification of the chiral phase structure of QCD due to an external magnetic field. We first demonstrate how the effect of magnetic field can systematically be incorporated into a generalized Ginzburg-Landau framework. We then analyze the phase structure in the vicinity of the chiral critical point. In the chiral limit, the effect is found to be so drastic that it brings a “continent” of chiral spiral in the phase diagram, by which the chiral tricritical point is totally washed out. This is the case no matter how small the intensity of magnetic field is. On the other hand, the current quark mass protects the chiral critical point from a weak magnetic field. However, the critical point will eventually be covered by the chiral spiral phase as the magnetic field grows.

  4. Heat transfer studies on spiral plate heat exchanger

    Directory of Open Access Journals (Sweden)

    Rajavel Rangasamy

    2008-01-01

    Full Text Available In this paper, the heat transfer coefficients in a spiral plate heat exchanger are investigated. The test section consists of a plate of width 0.3150 m, thickness 0.001 m and mean hydraulic diameter of 0.01 m. The mass flow rate of hot water (hot fluid is varying from 0.5 to 0.8 kg/s and the mass flow rate of cold water (cold fluid varies from 0.4 to 0.7 kg/s. Experiments have been conducted by varying the mass flow rate, temperature, and pressure of cold fluid, keeping the mass flow rate of hot fluid constant. The effects of relevant parameters on spiral plate heat exchanger are investigated. The data obtained from the experimental study are compared with the theoretical data. Besides, a new correlation for the Nusselt number which can be used for practical applications is proposed.

  5. Three-dimensional reconstruction of the biliary tract using spiral computed tomography. Three-dimensional cholangiography

    International Nuclear Information System (INIS)

    Gon, Masanori; Ogura, Norihiro; Uetsuji, Shouji; Ueyama, Yasuo

    1995-01-01

    In this study, 310 patients with benign biliary diseases, 20 with gallbladder cancer, and 8 with biliary tract carcinoma underwent spiral CT (SCT) scanning at cholangiography. Depiction rate of the shape of the conjunction site of the gallbladder and biliary tract was 27.5% by conventional intravenous cholangiography (DIC), 92.5% by ERC, and 90.0% by DIC-SCT. Abnormal cystic duct course was admitted in 14.1%. Multiplanar reconstruction by DIC-SCT enabled identification of the common bile duct and intrahepatic bile duct stone. Three-dimensional reconstruction of DIC-SCT was effective in evaluating obstruction of the anastomosis or passing condition of after hepatico-jejunostomy. Two-dimensional SCT images through PTCD tube enabled degree of hepatic invasion in bile duct cancer, and three-dimensional images were useful in grasping the morphology of the bile duct branches near the obstruction site. DIC-SCT is therefore considered a useful procedure as non-invasive examination of bile duct lesions. (S.Y.)

  6. Structure and Sound Absorption Properties of Spiral Vane Electrospun PVA/PEO Nanofiber Membranes

    Directory of Open Access Journals (Sweden)

    Huan Liu

    2018-02-01

    Full Text Available Noise pollution has become one of the four major pollution issues in the world and has drawn much attention recently. Controlling the sound source and using sound-absorbing materials reasonably is considered an effective way to reduce noise. Due to the high porosity and specific surface area, nanofibers membrane is widely used in the field of the sound absorption. Polyvinyl alcohol (PVA and Polyethylene oxide (PEO are both water-soluble polymers with good film-forming properties that can be mixed in any proportion. In this paper, nanofiber membranes were prepared by spiral vane electrospinning with different contents of PVA and PEO. The nanofibers membranes were characterized by Fourier Transform-Infrared (FT-IR, X-ray diffraction (XRD, 3D-M, and scanning electron microscopy (SEM. The sound absorption property of nanofibers membranes and the compositions (nanofiber membranes and needle punched non-woven fabric were tested with an impedance tube. The results demonstrate that the addition of PEO changed the morphological characteristics and construct of PVA, sound absorption properties had undergone great changes.

  7. Spiral and Rotor Patterns Produced by Fairy Ring Fungi

    Science.gov (United States)

    Karst, N.; Dralle, D.; Thompson, S. E.

    2015-12-01

    Soil fungi fill many essential ecological and biogeochemical roles, e.g. decomposing litter, redistributing nutrients, and promoting biodiversity. Fairy ring fungi offer a rare glimpse into the otherwise opaque spatiotemporal dynamics of soil fungal growth, because subsurface mycelial patterns can be inferred from observations at the soil's surface. These observations can be made directly when the fungi send up fruiting bodies (e.g., mushrooms and toadstools), or indirectly via the effect the fungi have on neighboring organisms. Grasses in particular often temporarily thrive on the nutrients liberated by the fungus, creating bands of rich, dark green turf at the edge of the fungal mat. To date, only annular (the "ring" in fairy ring) and arc patterns have been described in the literature. We report observations of novel spiral and rotor pattern formation in fairy ring fungi, as seen in publically available high-resolution aerial imagery of 22 sites across the continental United States. To explain these new behaviors, we first demonstrate that a well-known model describing fairy ring formation is equivalent to the Gray-Scott reaction-diffusion model, which is known to support a wide range of dynamical behaviors, including annular traveling waves, rotors, spirals, and stable spatial patterns including spots and stripes. Bifurcation analysis and numerical simulation are then used to define the region of parameter space that supports spiral and rotor formation. We find that this region is adjacent to one within which typical fairy rings develop. Model results suggest simple experimental procedures that could potentially induce traditional ring structures to exhibit rotor or spiral dynamics. Intriguingly, the Gray-Scott model predicts that these same procedures could be used to solicit even richer patterns, including spots and stripes, which have not yet been identified in the field.

  8. Spiral model of procedural cycle of educational process management

    OpenAIRE

    Bezrukov Valery I.; Lukashina Elena V.

    2016-01-01

    The article analyzes the nature and characteristics of the spiral model Procedure educational systems management cycle. The authors identify patterns between the development of information and communication technologies and the transformation of the education management process, give the characteristics of the concept of “information literacy” and “Media Education”. Consider the design function, determine its potential in changing the traditional educational paradigm to the new - information....

  9. Scintigraphic diagnosis of spiral fracture in young children

    International Nuclear Information System (INIS)

    Hossein-Foucher, C.; Venel, H.; Legouffe, P.; Ythier, H.; Legghe, R.; Marchandise, X.

    1988-01-01

    The authors report 8 cases of unsuspected bone fracture in children, identified at bone scan. Common features were the children's young age (1 to 3 years), the absence of clinical suspicion, the initially normal X-rays, the fracture type (sprial fracture of the tibia undisplaced), and the uniform of appearance the bone scan. These data confirm the value of the bone scan in limping children and suggest that spiral fracture of the tibia is a frequent and underdiagnosed condition in children [fr

  10. Spontaneous spiral formation in two-dimensional oscillatory media

    Science.gov (United States)

    Kettunen, Petteri; Amemiya, Takashi; Ohmori, Takao; Yamaguchi, Tomohiko

    1999-08-01

    Computational studies of pattern formation in a modified Oregonator model of the Belousov-Zhabotinsky reaction is described. Initially inactive two-dimensional reaction media with an immobilized catalyst is connected to a reservoir of fresh reactants through a set of discrete points distributed randomly over the interphase surface. It is shown that the diffusion of reactants combined with oscillatory reaction kinetics can give rise to spontaneous spiral formation and phase waves.

  11. Superelastic NiTi memory alloy micro-tube under tension - nucleation and propagation of martensite band

    International Nuclear Information System (INIS)

    Li, Z.Q.; Sun, Q.P.

    2000-01-01

    The superelastic behavior of polycrystalline NiTi shape memory alloy micro-tube under tension is studied experimentally. The nominal stress-strain curve of the micro-tube is recorded. By using a special surface coating it is found that the deformation of the tube is via the nucleation and propagation of stress-induced martensite band. The experiments show that the martensite nucleates in the form of a spiral lens-shaped narrow band that is inclined at 61 to the axis of loading when the stress reaches the peak of stress-strain curve. The width and the length of the band grew gradually with increase of loading and finally joined and merged into a single band. The subsequent deformation of the tube is realized by the propagation of this cylindrical martensite band. (orig.)

  12. CRL X-ray tube

    International Nuclear Information System (INIS)

    Kolchevsky, N.N.; Petrov, P.V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed. (authors)

  13. CRL X-RAY TUBE

    OpenAIRE

    Kolchevsky, N. N.; Petrov, P. V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed.

  14. Infrared emission and tidal interactions of spiral galaxies

    International Nuclear Information System (INIS)

    Byrd, G.G.

    1987-01-01

    Computer simulations of tidal interactions of spiral galaxies are used to attempt to understand recent discoveries about infrared (IR) emitting galaxies. It is found that the stronger tidal perturbation by a companion the more disk gas clouds are thrown into nucleus crossing orbits and the greater the velocity jumps crossing spiral arms. Both these tidally created characteristics would create more IR emission by high speed cloud collisions and more IR via effects of recently formed stars. This expectation at greater tidal perturbation matches the observation of greater IR emission for spiral galaxies with closer and/or more massive companions. The greater collision velocities found at stronger perturbations on the models will also result in higher dust temperature in the colliding clouds. In the IR pairs examined, most have only one member, the larger, detected and when both are detected, the larger is always the more luminous. In simulations and in a simple analytic description of the strong distance dependence of the tidal force, it is found that the big galaxy of a pair is more strongly affected than the small

  15. Ultra-precision turning of complex spiral optical delay line

    Science.gov (United States)

    Zhang, Xiaodong; Li, Po; Fang, Fengzhou; Wang, Qichang

    2011-11-01

    Optical delay line (ODL) implements the vertical or depth scanning of optical coherence tomography, which is the most important factor affecting the scanning resolution and speed. The spinning spiral mirror is found as an excellent optical delay device because of the high-speed and high-repetition-rate. However, it is one difficult task to machine the mirror due to the special shape and precision requirement. In this paper, the spiral mirror with titled parabolic generatrix is proposed, and the ultra-precision turning method is studied for its machining using the spiral mathematic model. Another type of ODL with the segmental shape is also introduced and machined to make rotation balance for the mass equalization when scanning. The efficiency improvement is considered in details, including the rough cutting with the 5- axis milling machine, the machining coordinates unification, and the selection of layer direction in turning. The onmachine measuring method based on stylus gauge is designed to analyze the shape deviation. The air bearing is used as the measuring staff and the laser interferometer sensor as the position sensor, whose repeatability accuracy is proved up to 10nm and the stable feature keeps well. With this method developed, the complex mirror with nanometric finish of 10.7nm in Ra and the form error within 1um are achieved.

  16. Intracranial aneurysms: evaluation in 200 patients with spiral CT angiography

    International Nuclear Information System (INIS)

    Young, N.; Kingston, R.J.; Markson, G.; Dorsch, N.W.C.; McMahon, J.

    2001-01-01

    The goal of this study was to assess the usefulness of spiral CT angiography (CTA) with three- dimensional reconstructions in defining intracranial aneurysms, particularly around the Circle of Willis. Two hundred consecutive patients with angiographic and/or surgical correlation were studied between 1993 and 1998, with CTA performed on a GE HiSpeed unit and Windows workstation. The following clinical situations were evaluated: conventional CT suspicion of an aneurysm; follow-up of treated aneurysm remnants or of untreated aneurysms; subarachnoid haemorrhage (SAH) and negative angiography; family or past aneurysm history; and for improved definition of aneurysm anatomy. Spiral CTA detected 140 of 144 aneurysms, and an overall sensitivity of 97%, including 30 of 32 aneurysms 3 mm or less in size. In 38 patients with SAH and negative angiography, CTA found six of the seven aneurysms finally diagnosed. There was no significant artefact in 17 of 23 patients (74%) with clips. The specificity of CTA was 86% with 8 false-positive cases. Spiral CTA is very useful in demonstrating intracranial aneurysms. (orig.)

  17. TURBULENCE AND STAR FORMATION IN A SAMPLE OF SPIRAL GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Erin; Chien, Li-Hsin [Department of Physics and Astronomy, Northern Arizona University 527 S Beaver Street, Flagstaff, AZ 86011 (United States); Hunter, Deidre A., E-mail: erin-maier@uiowa.edu, E-mail: Lisa.Chien@nau.edu, E-mail: dah@lowell.edu [Lowell Observatory 1400 W Mars Hill Road, Flagstaff, AZ 86001 (United States)

    2016-11-01

    We investigate turbulent gas motions in spiral galaxies and their importance to star formation in far outer disks, where the column density is typically far below the critical value for spontaneous gravitational collapse. Following the methods of Burkhart et al. on the Small Magellanic Cloud, we use the third and fourth statistical moments, as indicators of structures caused by turbulence, to examine the neutral hydrogen (H i) column density of a sample of spiral galaxies selected from The H i Nearby Galaxy Survey. We apply the statistical moments in three different methods—the galaxy as a whole, divided into a function of radii and then into grids. We create individual grid maps of kurtosis for each galaxy. To investigate the relation between these moments and star formation, we compare these maps with their far-ultraviolet images taken by the Galaxy Evolution Explorer satellite.We find that the moments are largely uniform across the galaxies, in which the variation does not appear to trace any star-forming regions. This may, however, be due to the spatial resolution of our analysis, which could potentially limit the scale of turbulent motions that we are sensitive to greater than ∼700 pc. From comparison between the moments themselves, we find that the gas motions in our sampled galaxies are largely supersonic. This analysis also shows that the Burkhart et al. methods may be applied not just to dwarf galaxies but also to normal spiral galaxies.

  18. Magnetostrictive hypersound generation by spiral magnets in the vicinity of magnetic field induced phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Bychkov, Igor V. [Chelyabinsk State University, 129 Br. Kashirinykh Str., Chelyabinsk 454001 (Russian Federation); South Ural State University (National Research University), 76 Lenin Prospekt, Chelyabinsk 454080 (Russian Federation); Kuzmin, Dmitry A., E-mail: kuzminda@csu.ru [Chelyabinsk State University, 129 Br. Kashirinykh Str., Chelyabinsk 454001 (Russian Federation); South Ural State University (National Research University), 76 Lenin Prospekt, Chelyabinsk 454080 (Russian Federation); Kamantsev, Alexander P.; Koledov, Victor V.; Shavrov, Vladimir G. [Kotelnikov Institute of Radio-engineering and Electronics of RAS, Mokhovaya Street 11-7, Moscow 125009 (Russian Federation)

    2016-11-01

    In present work we have investigated magnetostrictive ultrasound generation by spiral magnets in the vicinity of magnetic field induced phase transition from spiral to collinear state. We found that such magnets may generate transverse sound waves with the wavelength equal to the spiral period. We have examined two types of spiral magnetic structures: with inhomogeneous exchange and Dzyaloshinskii–Moriya interactions. Frequency of the waves from exchange-caused spiral magnetic structure may reach some THz, while in case of Dzyaloshinskii–Moriya interaction-caused spiral it may reach some GHz. These waves will be emitted like a sound pulses. Amplitude of the waves is strictly depends on the phase transition speed. Some aspects of microwaves to hypersound transformation by spiral magnets in the vicinity of phase transition have been investigated as well. Results of the work may be interesting for investigation of phase transition kinetics as well, as for various hypersound applications. - Highlights: • Magnetostrictive ultrasound generation by spiral magnets at phase transition (PT) is studied. • Spiral magnets during PT may generate transverse sound with wavelength equal to spiral period. • Amplitude of the sound is strictly depends on the phase transition speed. • Microwave-to-sound transformation in the vicinity of PT is investigated as well.

  19. Diagnosis of pulmonary embolism with spiral and electron-beam CT; Diagnostik der Lungenembolie mit Spiral- und Elektronenstrahl-CT

    Energy Technology Data Exchange (ETDEWEB)

    Schoepf, U.J.; Bruening, R.D.; Becker, C.R.; Konschitzky, H.; Muehling, O.; Staebler, A.; Helmberger, T.; Holzknecht, N.; Reiser, M.F. [Muenchen Univ. (Germany). Inst. fuer Radiologische Diagnostik; Knez, A.; Haberl, R. [Muenchen Univ. (Germany). Medizinische Klinik 1

    1998-12-01

    Purpose: To compare spiral (SCT) and electron-beam CT (EBT) for the diagnosis of pulmonary embolism (PE). Materials and methods: From June 1997 to June 1998 188 patients with suspected acute or chronic thrombembolism of the pulmonary arteries were examined. A total of 108 patients were scanned using SCT and 80 patients using EBT. On each scanner two different scan protocols were evaluated. Conclusions: Advanced CT scanning techniques allow the highly accurate diagnosis of central and peripheral PE. Other potentially life-threatening underlying diseases are also readily recognized. (orig./AJ) [Deutsch] Fragestellung: Spiral-CT (SCT) und Elektronenstrahlcomputertomographie (EBT) sollten hinsichtlich ihrer Eignung fuer die Diagnostik der Lungenembolie (LE) verglichen werden. Methode: Von Juni 1997 bis Juni 1998 wurden 188 Patienten mit Verdacht auf akute oder chronische thrombembolische Veraenderungen der Lungenarterien untersucht. Die CT-Diagnostik erfolgte dabei bei 108 Patienten mit Spiral-CT und bei 80 Patienten mit EBT. Schlussfolgerungen: Moderne CT-Scan-Verfahren erlauben mit hoher Genauigkeit die Diagnose der zentralen und peripheren Lungenembolie. Die EBT bietet Vorteile in der Darstellung herznaher peripherer Lungenarterien. Andere lebendsbedrohliche Ursachen fuer die Beschwerden des Patienten werden mit der CT sicher erkannt. (orig./AJ)

  20. Naming polyhedra by general face-spirals - theory and applications to fullerenes and other polyhedral molecules

    DEFF Research Database (Denmark)

    Wirz, Lukas; Schwerdtfeger, Peter; Avery, James Emil

    2018-01-01

    We present a general face-spiral algorithm for cubic polyhedral graphs (including fullerenes and fulleroids), and extend it to the full class of all polyhedral graphs by way of the leapfrog transform. This yields compact canonical representations of polyhedra with a simple and intuitive geometrical...... be found together with the canonical general spiral at negligible cost. The algorithm is fully compatible with the classical spiral algorithm developed by Manolopoulos for fullerenes, i. e., classical spirals are accepted as input, and spiralable graphs lead to identical output. We prove that the algorithm...... is correct and complete. The worst case runtime complexity is for general N-vertex polyhedral graphs, with J the sum of all jump lengths. When the number of faces of any particular size is bounded by a constant, such as the case for fullerenes, this reduces to . We have calculated canonical general spirals...

  1. Drift and breakup of spiral waves in reaction–diffusion–mechanics systems

    OpenAIRE

    Panfilov, A. V.; Keldermann, R. H.; Nash, M. P.

    2007-01-01

    Rotating spiral waves organize excitation in various biological, physical, and chemical systems. They underpin a variety of important phenomena, such as cardiac arrhythmias, morphogenesis processes, and spatial patterns in chemical reactions. Important insights into spiral wave dynamics have been obtained from theoretical studies of the reaction–diffusion (RD) partial differential equations. However, most of these studies have ignored the fact that spiral wave rotation is often accompanied by...

  2. Osteocyte Lacunae are Lenticular/Ellipsoid Spaces or Spiral/Helical Tubules

    Directory of Open Access Journals (Sweden)

    Bijit Kanti Guha

    2017-10-01

    Full Text Available Introduction: According to the current concept of bone structure, the osteocyte lacunae are lenticular or ellipsoid spaces occupied by osteocytes. These osteocytes are thought to communicate with each other through a tubular system made up of Canaliculi. The rest of the structures i.e., Haversian canal, and Volkmann’s canal are also tubular in shape. Considering this existing concept of bone microstructure described by various authors, it is highly unlikely that the lacunae alone would be lenticular/ellipsoid structure. In the present study author wanted to know that amongst the all tubular spaces, what is the reason that only the osteocyte lacunae are lenticular or ellipsoid structure? Also to investigate whether these lenticular spaces are really lenticular/ellipsoid or they are cut sections of tubes, which are lying helically or spirally. It is well known from various previous studies that Haversian canal, Volkmann’s canal and Canaliculi are tubular shaped structures and how it is possible that lenticular/ellipsoid structure can present amongst them. So we thought that, it may be possible that these lenticular spaces are not actually lenticular but this lenticular shape is due to the cut sections of any type of tubule in various possible planes (i.e., transverse, longitudinal and various degrees of oblique plane. Aim: The present study was carried out to reinvestigate the shape of the osteocyte lacunae amongst the tubular system (i.e., Haversian canal, Volkmann’s canal and Canaliculi of compact bone. Materials and Methods: The study is carried out by preparing thin sections of adult bones (ground glass preparation and visualizing them under binocular light microscope and scanelectron microscope after following proper procedure. Results: We observed that the lacunae are actually spirally/helically placed tubules with several branching. These branching are considered as canaliculi. These branching are of various diameters and they

  3. Free compression tube. Applications

    Science.gov (United States)

    Rusu, Ioan

    2012-11-01

    During the flight of vehicles, their propulsion energy must overcome gravity, to ensure the displacement of air masses on vehicle trajectory, to cover both energy losses from the friction between a solid surface and the air and also the kinetic energy of reflected air masses due to the impact with the flying vehicle. The flight optimization by increasing speed and reducing fuel consumption has directed research in the aerodynamics field. The flying vehicles shapes obtained through studies in the wind tunnel provide the optimization of the impact with the air masses and the airflow along the vehicle. By energy balance studies for vehicles in flight, the author Ioan Rusu directed his research in reducing the energy lost at vehicle impact with air masses. In this respect as compared to classical solutions for building flight vehicles aerodynamic surfaces which reduce the impact and friction with air masses, Ioan Rusu has invented a device which he named free compression tube for rockets, registered with the State Office for Inventions and Trademarks of Romania, OSIM, deposit f 2011 0352. Mounted in front of flight vehicles it eliminates significantly the impact and friction of air masses with the vehicle solid. The air masses come into contact with the air inside the free compression tube and the air-solid friction is eliminated and replaced by air to air friction.

  4. Shock tube Multiphase Experiments

    Science.gov (United States)

    Middlebrooks, John; Allen, Roy; Paudel, Manoj; Young, Calvin; Musick, Ben; McFarland, Jacob

    2017-11-01

    Shock driven multiphase instabilities (SDMI) are unique physical phenomena that have far-reaching practical applications in engineering and science. The instability is present in high energy explosions, scramjet combustors, and supernovae events. The SDMI arises when a multiphase interface is impulsively accelerated by the passage of a shockwave. It is similar in development to the Richtmyer-Meshkov (RM) instability however, particle-to-gas coupling is the driving mechanism of the SDMI. As particle effects such as lag and phase change become more prominent, the SDMI's development begins to significantly deviate from the RM instability. We have developed an experiment for studying the SDMI in our shock tube facility. In our experiments, a multiphase interface is created using a laminar jet and flowed into the shock tube where it is accelerated by the passage of a planar shockwave. The interface development is captured using CCD cameras synchronized with planar laser illumination. This talk will give an overview of new experiments conducted to examine the development of a shocked cylindrical multiphase interface. The effects of Atwood number, particle size, and a second acceleration (reshock) of the interface will be discussed.

  5. Pulmonary embolism: spiral CT evaluation; Embolie pulmonaire: apport de la tomodensitometrie helicoidale

    Energy Technology Data Exchange (ETDEWEB)

    Senac, J.P.; Vernhet, H.; Bousquet, C.; Giron, J.; Pieuchot, P.; Durand, G.; Benezet, O.; Aubas, P. [Centre Hospitalier Universitaire, 34 - Montpellier (France)

    1995-06-01

    Purpose: Spiral computed tomography was compared retrospectively with digital substraction pulmonary angiography (PA) in 45 patients suspected of having acute or chronic pulmonary embolism. Materials and method : 45 patients in whom the presence of acute or chronic pulmonary embolism was suspected underwent examination by spiral CT and PA. Diagnosis of pulmonary embolism was based on the direct visualization of intraluminal clots. The study of the agreement between the two methods was based on the Kappa test. In 35 cases, pulmonary emboli were proved. Acute pulmonary emboli were present in 28 cases and chronic in 7 cases. Results: Spiral computed tomography represents an excellent way to detect acute pulmonary embolism. In the chronic form, spiral CT is better than PA to detect intraluminal clots. However, Spiral CT can fail to detect small emboli in the peripheral arterial bed. In the 10 patients without pulmonary embolism, the spiral CT proved diagnosis pulmonary oedema (n=3), lymphangi-carcinoma (n=4), pleural effusion (n=3). Conclusion: This study suggest that the spiral CT examination is accurate for diagnosis of pulmonary embolism specifically in case of suspected important embolism. The advantages of spiral CT are multiple (non invasive, wide diagnosis spectrum). However, may be a limitation to is use is insufficient distal thrombi detection. This eventuality (5 to 10% in the Pioped study) justify the practice of pulmonary angiography. Spiral CT improvements should reduce this insufficiency in the next future. (Authors). 16 refs., 4 figs., 3 tabs.

  6. Magnetic field sensor based on fiber Bragg grating with a spiral microgroove ablated by femtosecond laser.

    Science.gov (United States)

    Dai, Yutang; Yang, Minghong; Xu, Gang; Yuan, Yinquan

    2013-07-15

    A novel magnetic field sensor based on Terfenol-D coated fiber Bragg grating with spiral microstructure was proposed and demonstrated. Through a specially-designed holder, the spiral microstructure was ablated into the fiber Bragg grating (FBG) cladding by femtosecond laser. Due to the spiral microstructure, the sensitivity of FBG coated with magnetostrictive film was enhanced greatly. When the spiral pitch is 50 μm and microgroove depth is 13.5 μm, the sensitivity of the magnetic field sensor is roughly 5 times higher than that of non-microstructured standard FBG. The response to magnetic field is reversible, and could be applicable for magnetic field detection.

  7. Geometric Offsets Across Spiral Arms in M51: Nature of Gas and Star Formation Tracers

    OpenAIRE

    Louie, M.; Koda, J.; Egusa, F.

    2013-01-01

    We report measurements of geometric offsets between gas spiral arms and associated star forming regions in the grand-design spiral galaxy M51. These offsets are a suggested measure of the star formation timescale after the compression of gas at spiral arm entry. A surprising discrepancy, by an order of magnitude, has been reported in recent offset measurements in nearby spiral galaxies. Measurements using CO and H-alpha emission find large and ordered offsets in M51. On the contrary, small or...

  8. A novel measuring method for arbitrary optical vortex by three spiral spectra

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Bo [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Guo, Lana [School of Electronics and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China); Yue, Chengfeng [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Tang, Zhilie, E-mail: tangzhl@scnu.edu.cn [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China)

    2017-02-26

    In this letter, the topological charge of non-integer vortices determined by three arbitrary spiral spectra is theoretically demonstrated for the first time. Based on the conclusion, a novel method to measure non-integer vortices is presented. This method is applicable not only to arbitrary non-integer vortex but also to arbitrary integer vortex. - Highlights: • Different non-integer vortices cannot have three spiral spectra is demonstrated. • Relationship between the non-integer topological charge and the spiral spectra is presented. • Topological charge of non-integer vortices can be determined by three arbitrary spiral spectra.

  9. CFD simulation of flow through single and multi vane spiral pump for low pressure application using moving node unsteady computation

    International Nuclear Information System (INIS)

    Banerjee, I.; Mahendra, A.K.; Chandresh, B.G.; Srikanthan, M.R.; Bera, T.K.

    2010-01-01

    A spiral pump uses two interleaved spirals (it can be involutes of a circle, involutes of a square, hybrid wraps, Archimedean spiral, logarithmic spirals and so on). Interleaved spiral orbits eccentrically without rotation around a fixed scroll, thereby trapping and compressing pockets of fluids between the spirals. Another method of providing the compression motion is by virtue of co-rotating the spirals synchronously with an offset in centers of rotation thereby providing relative motion similar to orbiting. Recently spiral pumps for low-pressure application have become popular. Since spiral pumps contain gas volumes, whose shapes and size change continuously, the flow fields inside the pumps is time dependent. The unsteadiness controls the mechanisms responsible for the behavior of the spiral pump components. To improve the spiral pump design for better performance as per our process requirement and reliability, information is required to understand the detailed physics of the unsteady flows inside the spiral pumps. The unsteady flows in a pump are studied numerically. The system simulated includes one side gap between fixed and moving spirals as the other side lies just in the reverse symmetry of the one side. Heavy molecular weight, condensable gas is used as the moving fluid. The mesh free Least Square Kinetic Upwind Method (LSKUM) for moving node is applied for numerical analysis of wobbling spiral. Nodes and boundaries change their positions, for every real time step hence at every iteration nodes take new coordinates. Our work consists of identifying various spiral dimensions and geometry, geometric modeling of suction process, identifying the eccentric orbiting motion of the moving spiral, formation of variable velocity moving nodes. Flow analysis of the spiral pump is done with a view to design and develop new pump as per our requirement. Experimental data from an existing spiral pump is used to carryout validation of the code. (author)

  10. Bacterial Biofilms in Jones Tubes.

    Science.gov (United States)

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  11. Failure analysis of boiler tube

    International Nuclear Information System (INIS)

    Mehmood, K.; Siddiqui, A.R.

    2007-01-01

    Boiler tubes are energy conversion components where heat energy is used to convert water into high pressure superheated steam, which is then delivered to a turbine for electric power generation in thermal power plants or to run plant and machineries in a process or manufacturing industry. It was reported that one of the tubes of a fire-tube boiler used in a local industry had leakage after the formation of pits at the external surface of the tube. The inner side of the fire tube was working with hot flue gasses with a pressure of 10 Kg/cm/sup 2/ and temperature 225 degree C. The outside of the tube was surrounded by feed water. The purpose of this study was to determine the cause of pits developed at the external surface of the failed boiler tube sample. In the present work boiler tube samples of steel grade ASTM AI61/ASTM A192 were analyzed using metallographic analysis, chemical analysis, and mechanical testing. It was concluded that the appearance of defects on the boiler tube sample indicates cavitation type corrosion failure. Cavitation damage superficially resembled pitting, but surface appeared considerably rougher and had many closely spaced pits. (author)

  12. YouTube and 'psychiatry'.

    Science.gov (United States)

    Gordon, Robert; Miller, John; Collins, Noel

    2015-12-01

    YouTube is a video-sharing website that is increasingly used to share and disseminate health-related information, particularly among younger people. There are reports that social media sites, such as YouTube, are being used to communicate an anti-psychiatry message but this has never been confirmed in any published analysis of YouTube clip content. This descriptive study revealed that the representation of 'psychiatry' during summer 2012 was predominantly negative. A subsequent smaller re-analysis suggests that the negative portrayal of 'psychiatry' on YouTube is a stable phenomenon. The significance of this and how it could be addressed are discussed.

  13. Radiation-resistant camera tube

    International Nuclear Information System (INIS)

    Kuwahata, Takao; Manabe, Sohei; Makishima, Yasuhiro

    1982-01-01

    It was a long time ago that Toshiba launched on manufacturing black-and-white radiation-resistant camera tubes employing nonbrowning face-plate glass for ITV cameras used in nuclear power plants. Now in compliance with the increasing demand in nuclear power field, the Company is at grips with the development of radiation-resistant single color-camera tubes incorporating a color-stripe filter for color ITV cameras used under radiation environment. Herein represented are the results of experiments on characteristics of materials for single color-camera tubes and prospects for commercialization of the tubes. (author)

  14. Virtual gastroscopy using spiral CT in gastric lesions

    International Nuclear Information System (INIS)

    Shin, Sang Soo; Kang, Heoung Keun; Jeong, Yong Yeon; Yoon, Man Won; Song, Sang Gook; Jeong, Gwang Woo

    1998-01-01

    To compare virtual gastroscopy using spiral CT with conventional endoscopy for the detection and evaluation of gastric lesions. During a previous six-month period, 30 patients with pathologically-proven gastric lesions underwent conventional endoscopy and virtual gastroscopy using spiral CT. There were 18 cases of advanced gastric carcinoma, eight benign ulcers, and four submucosal tumors(two leiomyomas, two lymphomas). Source images of virtual gastroscopy were three-dim-ensionally reconstructed within an Advantage Windows Workstation and virtual gastroscopic images were obtained using Navigator Software. On analysis, images were graded according to their quality(excellent, good, poor). Virtual gastroscopic images were interpreted by two radiologists blinded to conventional endoscopic findings, and were subsequently compared with endoscopic findings in terms of detectability and findings. In the cases of advanced gastric carcinoma, lesions were classified according to Borrmann's system. For virtual gastroscopy, overall image quality was excellent in 21 cases(70%), good in five(17%), and poor in four(13%). Lesions were detected in 25 cases(83%). Among the 18 advanced gastric carcinomas, virtual gastroscopy image quality was excellent in 14 cases(78%), good in two(11%), and poor in two(11%). Lesions were detected in 16 cases(89%). Two Borrmann type IV cases were not detected. Among the eight benign ulcers, virtual gastroscopy image quality was excellent in three cases(38%), good in three(38%), and poor in two(25%). The detection of lesion was possible in five cases(63%). In all submucosal tumors, virtual gastroscopy image quality was excellent. Lesions were detected in all cases. Virtual gastroscopy using spiral CT is safe and noninvasive, and for the evaluation of gastric lesions may be complementary to axial CT. It successfully detects gastric lesions, and in depicting the pattern of gastric folds its image quality is excellent.=20

  15. Galactic masers: Kinematics, spiral structure and the disk dynamic state

    Science.gov (United States)

    Rastorguev, A. S.; Utkin, N. D.; Zabolotskikh, M. V.; Dambis, A. K.; Bajkova, A. T.; Bobylev, V. V.

    2017-04-01

    We applied the currently most comprehensive version of the statistical-parallax technique to derive kinematical parameters of the maser sample with 136 sources. Our kinematic model comprises the overall rotation of the Galactic disk and the spiral density-wave effects. We take into account the variation of radial velocity dispersion with Galactocentric distance. The best description of the velocity field is provided by the model with constant radial and vertical velocity dispersions, $(\\sigma U0, \\sigma W0) \\approx (9.4 \\pm 0.9~, 5.9 \\pm 0.8)~ km/s$. We compute flat Galactic rotation curve over the Galactocentric distance interval from 3 to 15 kpc and find the local circular rotation velocity to be $ V_0 \\approx (235-238)$~ km/s $\\pm 7$~ km/s. We also determine the parameters of the four-armed spiral pattern (pitch angle $i \\approx (-10.4 \\pm 0.3)^\\circ$ and the phase of the Sun $\\chi_0 \\approx (125 \\pm 10) ^\\circ$). The radial and tangential spiral perturbations are about $f_R \\approx (-6.9 \\pm 1.4)$~km/s, $f_\\Theta \\approx (+2.8 \\pm 1.0$) ~km/s. The kinematic data yield a solar Galactocentric distance of $R_0 \\approx (8.24 \\pm 0.12)~kpc$. Based on rotation curve parameters and the asymmetric drift we Infer the exponential disk scale $H_D \\approx (2.7 \\pm 0.2)$ ~kpc under assumption of marginal stability of the intermediate-age disk, and finally we estimate the minimum local surface disk density, $\\Sigma (R_0) > (26 \\pm 3) ~ M_\\odot pc^{-2}$.

  16. A spiral model of musical decision-making

    Directory of Open Access Journals (Sweden)

    Daniel eBangert

    2014-04-01

    Full Text Available This paper describes a model of how musicians make decisions about performing notated music. The model builds on psychological theories of decision-making and was developed from empirical studies of Western art music performance that aimed to identify intuitive and deliberate processes of decision-making, a distinction consistent with dual-process theories of cognition. The model proposes that the proportion of intuitive (Type 1 and deliberate (Type 2 decision-making processes changes with increasing expertise and conceptualises this change as movement along a continually narrowing upward spiral where the primary axis signifies principal decision-making type and the vertical axis marks level of expertise. The model is intended to have implications for the development of expertise as described in two main phases. The first is movement from a primarily intuitive approach in the early stages of learning towards greater deliberation as analytical techniques are applied during practice. The second phase occurs as deliberate decisions gradually become automatic (procedural, increasing the role of intuitive processes. As a performer examines more issues or reconsiders decisions, the spiral motion towards the deliberate side and back to the intuitive is repeated indefinitely. With increasing expertise, the spiral tightens to signify greater control over decision type selection. The model draws on existing theories, particularly Evans’ (2011 Intervention Model of dual-process theories, Cognitive Continuum Theory (Hammond et al., 1987; Hammond, 2007, and Baylor’s (2001 U-shaped model for the development of intuition by level of expertise. By theorising how musical decision-making operates over time and with increasing expertise, this model could be used as a framework for future research in music performance studies and performance science more generally.

  17. Spiral Structure and Global Star Formation Processes in M 51

    Science.gov (United States)

    Gruendl, Robert A.

    1994-12-01

    The nearby grand design spiral galaxy, M 51, is an obvious proving ground for studies of spiral structure and large scale star formation processes. New near--infrared observations of M 51 made with COB (Cryogenic Optical Bench) on the Kitt Peak 1.3m allow us to examine the stellar distribution and the young star formation regions as well as probe regions of high extinction such as dust lanes. We also present an analysis of the kinematics of the ionized gas observed with the Maryland--Caltech Imaging Fabry Perot. The color information we derive from the near--infrared bands provides a more accurate tracer of extinction than optical observations. We find that the dust extinction and CO emission in the arms are well correlated. Our kinematic data show unambiguously that these dense gas concentrations are associated with kinematic perturbations. In the inner disk, these perturbations are seen to be consistent with the streaming motions predicted by classical density wave theory. The dust lanes, and presumably the molecular arms, form a narrow ridge that matches these velocity perturbations wherever the viewing angle is appropriate. This interpretation requires that the corotation radius be inward of the outer tidal arms. The outer tidal arms however show streaming velocities of the sign that would be expected interior to the corotation point. This can be reconciled if the outer arms are part of a second spiral pattern, most likely due to the interaction with the companion NGC 5195. The near--infrared observations also show emission from the massive star forming regions. These observations are less affected by extinction than optical observations of H II regions and show clearly that the sites of massive star formation are correlated with but downstream from the concentrations of dense molecular material. This provides clear evidence that the ISM has been organized by the streaming motions which have in turn triggered massive star formation.

  18. Learning from YouTube [Video Book

    Science.gov (United States)

    Juhasz, Alexandra

    2011-01-01

    YouTube is a mess. YouTube is for amateurs. YouTube dissolves the real. YouTube is host to inconceivable combos. YouTube is best for corporate-made community. YouTube is badly baked. These are a few of the things Media Studies professor Alexandra Juhasz (and her class) learned about YouTube when she set out to investigate what actually happens…

  19. Kinematics of molecular clouds: evidence for agglomeration in spiral arms

    International Nuclear Information System (INIS)

    Stark, A.A.

    1983-01-01

    A new survey of CO in the first Galactic quadrant has been analysed to yield a catalog of 320 molecular clouds near the tangent velocity. These clouds have known distances, so that cloud sizes and heights above the Galactic plane can be determined. The largest clouds (Msub(C) > 10sup(5.5) solar masses) have a reduced scale height relative to smaller clouds by an amount which is consistent with equipartition of energy. This can be interpreted as evidence for small clouds combining to form giant clouds in spiral arms. (Auth.)

  20. Motivational Spiral Models (MSM): common and distinct motivations in context

    OpenAIRE

    Fisher, Laurel J

    2013-01-01

    Motivational Spiral Models (MSM) show links over time among self concepts, feelings, strategies, skills and participation in everyday activities. In theory, MSM have many common features, with distinct features in particular contexts. This project examined children?s motivation to participate in literacy (MSM-L), social (MSM-S) and physical activities (MSM-P). The participants in Study 1 (N?=?32) were 9 to 11 years old, and in Study 2 (N?=?73) were 4 to 12 year old children. Locations were cl...

  1. RFID Tag Design Using Spiral Resonators and Defected Ground Structure

    Directory of Open Access Journals (Sweden)

    M. Veysi

    2017-12-01

    Full Text Available This paper presents a simple generalized approach to design a compact chipless radio frequency identification tag. The proposed chipless tag encodes data into the spectral signature using a set of spiral resonators on both sides of substrate. Transmission amplitude component of the tag is used for data encoding. For miniaturization purpose, defected ground structure is used to reduce the circuit size by half compared to the conventional cascading technique. The proposed chipless tag operates between 4-6 GHz and produces 256 different binary strings through eight encoded bits. Measurement and simulation results verify the authenticity of this design.

  2. Vacuum sealing with a spiral grooved gas dynamic seal

    International Nuclear Information System (INIS)

    Sawada, Tadashi

    1979-01-01

    Gas dynamic seals with rectangular spiral grooves are studied theoretically taking the effects of sidewalls of the grooves and the effects of gas compressibility into account, and slip boundary conditions are employed. The results are compared with the existing experimental data and the validity of the theory is confirmed over a wide pressure range except for the extremely low pressures. Suggestions are made regarding the choice of the geometrical dimensions, i.e., aspect ratio, helix angle, clearance parameter and groove width ratio. (author)

  3. Spiral orbits and oscillations in historical evolution of empires

    Science.gov (United States)

    Cheon, Taksu; Poghosyan, Sergey S.

    2017-03-01

    We introduce the concept of metaasabiya, the second non-material resource, to the asabiya theory of historical dynamics. We find that the resulting three variable dynamical system has peculiar features such as repelling or attracting axes and spiraling orbits in the phase space. Depending on the initial state, the system can go through series of oscillatory rises and falls, mimicking the geopolitical evolution of real-world polities. These distinctive features, absent in conventional Lotka-Volterra type biological systems, reveal the hidden richness inherent in the asabiya theory.

  4. Tube to tube excursive instability - sensitivities and transients

    International Nuclear Information System (INIS)

    Brown, M.; Layland, M.W.

    1980-01-01

    A simple basic analysis of excursive instability in a boiler tube shows how it depends upon operating conditions and physical properties. A detailed mathematical model of an AGR boiler is used to conduct a steady state parameter sensitivity survey. It is possible from this basis to anticipate the effects of changes in operating conditions and changes in design parameters upon tube to tube stability. Dynamic responses of tubes operating near the stability threshold are examined using a mathematical model. Simulated excursions are triggered by imparting small abrupt pressure changes on the boiler inlet pressure. The influences of the magnitude of the pressure change, waterside friction factor and gas side coupling between tubes are examined. (author)

  5. Nasogastric tube syndrome induced by an indwelling long intestinal tube.

    Science.gov (United States)

    Sano, Naoki; Yamamoto, Masayoshi; Nagai, Kentaro; Yamada, Keiichi; Ohkohchi, Nobuhiro

    2016-04-21

    The nasogastric tube (NGT) has become a frequently used device to alleviate gastrointestinal symptoms. Nasogastric tube syndrome (NTS) is an uncommon but potentially life-threatening complication of an indwelling NGT. NTS is characterized by acute upper airway obstruction due to bilateral vocal cord paralysis. We report a case of a 76-year-old man with NTS, induced by an indwelling long intestinal tube. He was admitted to our hospital for treatment of sigmoid colon cancer. He underwent sigmoidectomy to release a bowel obstruction, and had a long intestinal tube inserted to decompress the intestinal tract. He presented acute dyspnea following prolonged intestinal intubation, and bronchoscopy showed bilateral vocal cord paralysis. The NGT was removed immediately, and tracheotomy was performed. The patient was finally discharged in a fully recovered state. NTS be considered in patients complaining of acute upper airway obstruction, not only with a NGT inserted but also with a long intestinal tube.

  6. A New Resonance Tube

    Science.gov (United States)

    Bates, Alan

    2017-12-01

    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at the point where sound is perceived to have maximum loudness, or at the point where the amplitude of the standing wave has maximum value, namely an antinode. An antinode coincides with the position of the tuning fork, beyond the end of the air column, which consequently introduces an end correction. One way to minimize this end correction is to measure the distance between consecutive antinodes.

  7. Piezoelectric Rotary Tube Motor

    Science.gov (United States)

    Fisher, Charles D.; Badescu, Mircea; Braun, David F.; Culhane, Robert

    2011-01-01

    A custom rotary SQUIGGLE(Registered TradeMark) motor has been developed that sets new benchmarks for small motor size, high position resolution, and high torque without gear reduction. Its capabilities cannot be achieved with conventional electromagnetic motors. It consists of piezoelectric plates mounted on a square flexible tube. The plates are actuated via voltage waveforms 90 out of phase at the resonant frequency of the device to create rotary motion. The motors were incorporated into a two-axis postioner that was designed for fiber-fed spectroscopy for ground-based and space-based projects. The positioner enables large-scale celestial object surveys to take place in a practical amount of time.

  8. Pressure tube reactor

    International Nuclear Information System (INIS)

    Matsumoto, Tomoyuki; Fujino, Michihira.

    1980-01-01

    Purpose: To equalize heavy water flow distribution by providing a nozzle for externally injecting heavy water from a vibration preventive plate to the upper portion to feed the heavy water in a pressure tube reactor and swallowing up heavy water in a calandria tank to supply the heavy water to the reactor core above the vibration preventive plate. Constitution: A moderator injection nozzle is mounted on the inner wall of a calandria tank. Heavy water is externally injected above the vibration preventive plate, and heavy water in the calandria tank is swallowed up to supply the heavy water to the core reactor above the vibration preventive plate. Therefore, the heavy water flow distribution can be equalized over the entire reactor core, and the distribution of neutron absorber dissolved in the heavy water is equalized. (Yoshihara, H.)

  9. Primary Fallopian Tube Carcinoma

    Directory of Open Access Journals (Sweden)

    Prasad K Shetty

    2011-01-01

    Full Text Available Primary Fallopian Tube Carcinoma (PFTC is rare and accounts for about 0.3% of all gynecologic cancers. Less than 1500 cases have been reported in the literature. It arises in postmenopausal women and typically presents with abdominal pelvic pain, vaginal bleeding and watery discharge. However, a correct diagnosis is rarely achieved preoperative, and in many cases, the diagnosis is made after incidental surgery for unrelated conditions commonly being ovarian carcinoma . Compared with ovarian carcinoma, PFTC more often presents at early stages, but it has a worse prognosis. PFTC is usually managed in the same manner as ovarian cancer. We report a case of Left PFTC that presented as Left ovarian mass, and we briefly review the literature.

  10. Fast breeder cladding tubes provided with helical fins

    International Nuclear Information System (INIS)

    Baumgaertner, E.; Hoffmann, H.; Miller, H.; Jacobi, O.; Bojarski, E.; Freund, D.; Reiser, H.

    1977-04-01

    Development of fast breeder tubes with helical fins started around 1966. The development was initiated mainly by the search for a more favorable alternative to the conventional spacers such as grids and spiral wires. First of all the possibility was investigated of fabricating them on an industrial scale. The first thermohydraulic and fluiddynamic tests were made in parallel by AEG, GfK and Interatom. Besides the possibility of industrial fabrication the problems of non-destructive testing for geometry and material defects had to be treated with priority. In this report the different stages of development are shown and, finally, two rather large projects are described. These projects are the study ready for the licensing procedure concerning the irradiation of finned tube oxide fuel elements in KNK II and the already completed 19-rod fuel element bundle irradiation experiment Mol 7D of GfK performed in the 500 kW sodium loop of the Belgian BR2 reactor. In this BR2 experiment the maximum target burnup of 85,000 MWd/t of oxide was attained without trouble. (orig.) [de

  11. Eddy current testing technology research of aluminum coating thickness on stainless steel tube inwall

    International Nuclear Information System (INIS)

    Li Xiaona; Hao Xingui

    2014-01-01

    Dynamic testing method of coating layer thickness of stainless steel tube is built up using eddy current testing technology. It is determined that others-contrast point-type probe is adopted, by comparing the detection performance of self-contrast and others-contrast type probes. To effectively solve the lift-off effect between dynamic detection, 3 nylon (4 m long per piece) is distributed by 120° in the circumferential direction of tube to be tested, which ensure the rotational alignment and avoid point-type probe lifting off the tube inner surface. And the special tighten clamping fixture is used for fixing stainless steel tube; so, the dynamic transmission device is designed and realized. Accuracy study under the condition of different frequency and gain is carried out using multi-frequency detection technology. At the same time, the detection precision under quadratic curve and exponential curve calibration modal is compared. And then, test parameters and curve generated model is determined to achieve the best accuracy. Finally, spiral scanning eddy current method is achieved for testing the aluminium cladding thickness on stainless steel tube inwall. The accuracy of detecting the thickness of coating layer by this method is ±3μm, the instability of rotating tooling is lower than 10%. This method achieved the domestic leading level. (authors)

  12. Characterization of tube support alloys

    International Nuclear Information System (INIS)

    Vaia, A.R.

    1985-01-01

    The involvement and relationship of carbon steel corrosion products in the tube denting phenomenon promoted an intensive research effort to: 1) understand, reproduce, and arrest the denting process, and 2) evaluate alternative tube support materials to provide additional corrosion resistance. The paper summarizes a corrosion testing program for the verification of type 405 stainless steel under acid or all volatile treatment conditions

  13. Flaming on YouTube

    NARCIS (Netherlands)

    Moor, Peter J.; Heuvelman, A.; Verleur, R.

    2010-01-01

    In this explorative study, flaming on YouTube was studied using surveys of YouTube users. Flaming is defined as displaying hostility by insulting, swearing or using otherwise offensive language. Three general conclusions were drawn. First, although many users said that they themselves do not flame,

  14. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... Amaurosis Low Vision Refractive Errors Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia NEI Home Contact Us A-Z Site Map NEI on Social Media Information in Spanish (Información en español) Website, ...

  15. 27 CFR 40.352 - Cigarette tubes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Cigarette tubes. 40.352... OF THE TREASURY (CONTINUED) TOBACCO MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Manufacture of Cigarette Papers and Tubes Taxes § 40.352 Cigarette tubes. Cigarette tubes...

  16. Three-dimensional dental imaging by spiral CT

    Science.gov (United States)

    Vannier, Michael W.; Hildebolt, Charles F.; Conover, Gary; Knapp, Robert H.; Yokoyama-Crothers, Naoko; Wang, Ge

    1995-05-01

    Three-dimensional image acquisition, display, and analysis of dental structures was performed and validated using spiral computed tomography (SCT) with metal artifact suppression. Isolated extracted teeth, a dry mandible, cadaver mandible, and cadaver head were scanned and reconstructed using a spiral CT scanner (Siemens Somatom PLUS-S) with 1 mm detector collimation, 1-mm table feed, and 0.1 - 1 mm reconstruction interval using specially developed software. Algorithms for metal artifact reduction including extended attenuation range and interpolation of missing projections were applied. Volumetric rendering of voxel sum images was performed to synthesize images comparable to conventional intraoral dental radiographs. Direct comparison of voxel-based synthetic and digitized film images was made. Several isolated, extracted teeth were sectioned with a diamond saw and submitted for histomorphometric analysis to aid in direct comparison with CT slice images obtained by multiplanar reconstruction. Metal artifact reduction was successful in markedly reducing the streaks and star patterns that usually accompany metallic restorations and intraoral appliances. Individual teeth were comparable to CT slice images. Voxel sum images were comparable to dental radiographs; however, for the SCT images, the spatial resolution was higher within the plane of section than it was orthogonal to the plane of section. Serial examinations were obtained by SCT, registered by surface matching, and interval change measured by 3D subtraction. Simulated lesions and restorations were introduced and quantitatively evaluated pre- and post-interventionally to assess imaging method performance.

  17. Semiclassical dynamics, Berry curvature, and spiral holonomy in optical quasicrystals

    Science.gov (United States)

    Spurrier, Stephen; Cooper, Nigel R.

    2018-04-01

    We describe the theory of the dynamics of atoms in two-dimensional quasicrystalline optical lattices. We focus on a regime of shallow lattice depths under which the applied force can cause Landau-Zener tunneling past a dense hierarchy of gaps in the quasiperiodic energy spectrum. We derive conditions on the external force that allow for a "semiadiabatic" regime in which semiclassical equations of motion can apply, leading to Bloch oscillations between the edges of a pseudo-Brillouin-zone. We verify this semiclassical theory by comparing to the results of an exact numerical solution. Interesting features appear in the semiclassical dynamics for the quasicrystal for a particle driven in a cyclic trajectory around the corner of the pseudo-Brillouin-zone: The particle fails to return to its initial state, providing a realization of a "spiral holonomy" in the dynamics. We show that there can appear anomalous velocity contributions, associated with nonzero Berry curvature. We relate these to the Berry phase associated with the spiral holonomy, and show how the Berry curvature can be accessed from the semiclassical dynamics. Finally, by identifying the pseudo-Brillouin-zone as a higher genus surface, we show that the Chern number classification for periodic systems can be extended to a quasicrystal, thereby determining a topological index for the system.

  18. Radioactive ion beam production by the ISOL method for SPIRAL

    International Nuclear Information System (INIS)

    Landre-Pellemoine, Frederique

    2001-01-01

    This work is directly related to the SPIRAL project (Systeme de Production d'Ions Radioactifs Acceleres en Lignes) of which the start up will begin in September 2001 at GANIL (Grand Accelerateur National d'Ions Lourds) in Caen. This thesis primarily concerns the development of radioactive ion production systems (target/ion source) by the thorough study of each production stage of the ISOL (Isotopic Separation On Line) method: target and/or projectile fragmentation production, diffusion out of target material, effusion into the ion source and finally the ionization of the radioactive atoms. A bibliographical research and thermal simulations allowed us to optimize materials and the shape of the production and diffusion targets. A first target was optimized and made reliable for the radioactive noble gases production (argon, neon...). A second target dedicated to the radioactive helium production was entirely designed and realised (from the specifications to the 'off line' and 'on line' tests). Finally, a third target source system was defined for singly-charged radioactive alkaline production. The intensities of secondary beams planned for SPIRAL are presented here. A detailed study of the diffusion effusion efficiency for these various targets showed that the use of a fine microstructure carbon (grain size of 1 μm) improved the diffusion and showed the importance of thickness of the lamella for the short lived isotope effusion. (author) [fr

  19. Distributed predictive control of spiral wave in cardiac excitable media

    International Nuclear Information System (INIS)

    Zheng-Ning, Gan; Xin-Ming, Cheng

    2010-01-01

    In this paper, we propose the distributed predictive control strategies of spiral wave in cardiac excitable media. The modified FitzHugh–Nagumo model was used to express the cardiac excitable media approximately. Based on the control-Lyapunov theory, we obtained the distributed control equation, which consists of a positive control-Lyapunov function and a positive cost function. Using the equation, we investigate two kinds of robust control strategies: the time-dependent distributed control strategy and the space-time dependent distributed control strategy. The feasibility of the strategies was demonstrated via an illustrative example, in which the spiral wave was prevented to occur, and the possibility for inducing ventricular fibrillation was eliminated. The strategies are helpful in designing various cardiac devices. Since the second strategy is more efficient and robust than the first one, and the response time in the second strategy is far less than that in the first one, the former is suitable for the quick-response control systems. In addition, our spatiotemporal control strategies, especially the second strategy, can be applied to other cardiac models, even to other reaction-diffusion systems. (general)

  20. MAGNETIC FIELDS IN A SAMPLE OF NEARBY SPIRAL GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Van Eck, C. L. [Department of Astrophysics, Faculty of Science, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands); Brown, J. C. [Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4 (Canada); Shukurov, A.; Fletcher, A., E-mail: c.vaneck@astro.ru.nl, E-mail: jocat@ucalgary.ca, E-mail: anvar.shukurov@ncl.ac.uk, E-mail: andrew.fletcher@ncl.ac.uk [School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2015-01-20

    Both observations and modeling of magnetic fields in the diffuse interstellar gas of spiral galaxies are well developed, but the theory has been confronted with observations for only a handful of individual galaxies. There is now sufficient data to consider the statistical properties of galactic magnetic fields. We have collected data from the literature on the magnetic fields and interstellar media of 20 spiral galaxies, and tested for various physically motivated correlations between magnetic field and interstellar medium parameters. Clear correlations emerge between the total magnetic field strength and molecular gas density as well as the star formation rate. The magnetic pitch angle exhibits correlations with the total gas density, the star formation rate, and the strength of the axisymmetric component of the mean magnetic field. The total and mean magnetic field strengths exhibit a noticeable degree of correlation, suggesting a universal behavior of the degree of order in galactic magnetic fields. We also compare the predictions of galactic dynamo theory to observed magnetic field parameters and identify directions in which theory and observations might be usefully developed.

  1. Spiral Dynamics of Consciousness. Possibilities of Use by Collective Managers

    Directory of Open Access Journals (Sweden)

    Doronin Andrii V.

    2014-03-01

    Full Text Available The goal of the article is showing a possibility of solution of the problem of reduction of human efficiency in the information society by means of growth of psychological load. Methodological grounds of the study are ideas of the American psychologist Clare William Graves, who, while developing the Abraham Maslow theory, created a system theory of evolution development of human consciousness, which determines human behaviour. Based of systemisation of conclusions of C. Graves and his followers the article formulates a hypothesis about expediency of use of spiral dynamics ideas for identifying reserves of strengthening of influence of the collective manager upon labour behaviour of subordinates. Test of hypothesis shows that, apart from diagnostics of the sources of activation of individual labour behaviour, the theory of spiral dynamics allows identification of reserves of formation of collective consciousness and solidary labour force of a creative collective. Their use creates a basis of intensification of processes of intellectualisation of the organisation capital. In order to ensure these changes it is necessary to find mechanisms of changing external environment, which sets principally new tasks and requires principally new strategies of their solution.

  2. Optical image encryption in Fresnel domain using spiral phase transform

    Science.gov (United States)

    Kumar, Ravi; Bhaduri, Basanta

    2017-09-01

    In this study, we propose a new nonlinear optical image encryption technique using spiral phase transform (SPT). First, the primary image is phase encoded and multiplied with a random amplitude mask (RAM), and using power function, the product is then powered to m. This powered output is Fresnel propagated with distance z 1 and then modulated with a random phase mask (RPM). The modulated image is further Fresnel propagated with distance z 2. Similarly, a security image is also modulated with another RAM and then Fresnel propagated with distance z 3. Next, the two modulated images after Fresnel propagations, are interfered and further Fresnel propagated with distance z 4 to get a complex image. Finally, this complex image is SPT with particular spiral phase function (SPF), to get the final encrypted image for transmission. In the proposed technique, the security keys are Fresnel propagation distances, the security image, RPM, RAMs, power order, m, and order of SPF, q. Numerical simulation results confirm the validity and effectiveness of the proposed technique. The proposed technique is robust against noise and brutal force attacks.

  3. A planar microfluidic mixer based on logarithmic spirals

    International Nuclear Information System (INIS)

    Scherr, Thomas; Nandakumar, Krishnaswamy; Quitadamo, Christian; Tesvich, Preston; Park, Daniel Sang-Won; Hayes, Daniel; Monroe, W Todd; Tiersch, Terrence; Choi, Jin-Woo

    2012-01-01

    A passive, planar micromixer design based on logarithmic spirals is presented. The device was fabricated using polydimethylsiloxane soft photolithography techniques, and mixing performance was characterized via numerical simulation and fluorescent microscopy. Mixing efficiency initially declined as the Reynolds number increased, and this trend continued until a Reynolds number of 15 where a minimum was reached at 53%. Mixing efficiency then began to increase reaching a maximum mixing efficiency of 86% at Re = 67. Three-dimensional (3D) simulations of fluid mixing in this design were compared to other planar geometries such as the Archimedes spiral and Meandering-S mixers. The implementation of logarithmic curvature offers several unique advantages that enhance mixing, namely a variable cross-sectional area and a logarithmically varying radius of curvature that creates 3D Dean vortices. These flow phenomena were observed in simulations with multilayered fluid folding and validated with confocal microscopy. This design provides improved mixing performance over a broader range of Reynolds numbers than other reported planar mixers, all while avoiding external force fields, more complicated fabrication processes and the introduction of flow obstructions or cavities that may unintentionally affect sensitive or particulate-containing samples. Due to the planar design requiring only single-step lithographic features, this compact geometry could be easily implemented into existing micro-total analysis systems requiring effective rapid mixing. (paper)

  4. A Rectangular Planar Spiral Antenna for GIS Partial Discharge Detection

    Directory of Open Access Journals (Sweden)

    Xiaoxing Zhang

    2014-01-01

    Full Text Available A rectangular planar spiral antenna sensor was designed for detecting the partial discharge in gas insulation substations (GIS. It can expediently receive electromagnetic waves leaked from basin-type insulators and can effectively suppress low frequency electromagnetic interference from the surrounding environment. Certain effective techniques such as rectangular spiral structure, bow-tie loading, and back cavity structure optimization during the antenna design process can miniaturize antenna size and optimize voltage standing wave ratio (VSWR characteristics. Model calculation and experimental data measured in the laboratory show that the antenna possesses a good radiating performance and a multiband property when working in the ultrahigh frequency (UHF band. A comparative study between characteristics of the designed antenna and the existing quasi-TEM horn antenna was made. Based on the GIS defect simulation equipment in the laboratory, partial discharge signals were detected by the designed antenna, the available quasi-TEM horn antenna, and the microstrip patch antenna, and the measurement results were compared.

  5. Acute cholecystitis: two-phase spiral CT finding

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Eung Young; Yoon, Myung Hwan; Yang, Dal Mo; Chun Seok; Bae, Jun Gi; Kim, Hak Soo; Kim, Hyung Sik [Chungang Ghil Hospital, Incheon (Korea, Republic of)

    1998-07-01

    To describe the two-phase spiral CT findings of acute cholecystitis. Materials and Methods : CT scans of nine patients with surgically-proven acute cholecystitis were retrospectively reviewed for wall thickening, enhancement pattern of the wall, attenuation of the liver adjacent to the gallbladder, gallstones,gallbladder distension, gas collection within the gallbladder, pericholecystic fluid and infiltration of pericholecystic fat. Results : In all cases, wall thickening of the gallbladder was seen, though this was more distinct on delayed images, Using high-low-high attenuation, one layer was seen in five cases, nd three layers in four. On arterial images, eight cases showed transient focal increased attenuation of the liver adjacent to the gall bladder;four of these showed curvilinear attenuation and four showed subsegmental attenuation. One case showed curvilinear decreased attenuation between increased attenuation of the liver and the gallbladder, and during surgery, severe adhesion between the liver and gallbladder was confirmed. Additional CT findings were infiltration of pericholecystic fat (n=9), gallstones (n=7), gallbladder distension (n=6), pericholecystic fluid(n=3), and gas collection within the gallbladder (n=2). Conclusion : In patients with acute cholecystitis,two-phase spiral CT revealed wall thickening in one or three layers ; on delayed images this was more distinct. In many cases, arterial images showed transient focal increased attenuation of the liver adjacent to the gallbladder.

  6. Novel nanofibrous spiral scaffolds for neural tissue engineering

    Science.gov (United States)

    Valmikinathan, Chandra M.; Tian, Jingjing; Wang, Junping; Yu, Xiaojun

    2008-12-01

    Due to several drawbacks associated with autografts and allografts, tissue-engineering approaches have been widely used to repair peripheral nerve injuries. Most of the traditional tissue-engineered scaffolds in use are either tubular (single or multi-lumen) or hydrogel-based cylindrical grafts, which provide limited surface area for cell attachment and regeneration. Here, we show a novel poly(lactide-co-glycotide) (PLGA) microsphere-based spiral scaffold design with a nanofibrous surface that has enhanced surface areas and possesses sufficient mechanical properties and porosities to support the nerve regeneration process. These scaffolds have an open architecture that goes evenly throughout the scaffolds hence leaving enough volume for media influx and deeper cell penetration into the scaffolds. The in vitro tests conducted using Schwann cells show that the nanofibrous spiral scaffolds promote higher cell attachment and proliferation when compared to contemporary tubular scaffolds or nanofiber-based tubular scaffolds. Also, the nanofiber coating on the surfaces enhances the surface area, mimics the extracellular matrix and provides unidirectional alignment of cells along its direction. Hence, we propose that these scaffolds could alleviate some drawbacks in current nerve grafts and could potentially be used in nerve regeneration.

  7. Radial and spiral stream formation in Proteus mirabilis colonies.

    Directory of Open Access Journals (Sweden)

    Chuan Xue

    2011-12-01

    Full Text Available The enteric bacterium Proteus mirabilis, which is a pathogen that forms biofilms in vivo, can swarm over hard surfaces and form a variety of spatial patterns in colonies. Colony formation involves two distinct cell types: swarmer cells that dominate near the surface and the leading edge, and swimmer cells that prefer a less viscous medium, but the mechanisms underlying pattern formation are not understood. New experimental investigations reported here show that swimmer cells in the center of the colony stream inward toward the inoculation site and in the process form many complex patterns, including radial and spiral streams, in addition to previously-reported concentric rings. These new observations suggest that swimmers are motile and that indirect interactions between them are essential in the pattern formation. To explain these observations we develop a hybrid model comprising cell-based and continuum components that incorporates a chemotactic response of swimmers to a chemical they produce. The model predicts that formation of radial streams can be explained as the modulation of the local attractant concentration by the cells, and that the chirality of the spiral streams results from a swimming bias of the cells near the surface of the substrate. The spatial patterns generated from the model are in qualitative agreement with the experimental observations.

  8. Influence of baryonic physics in simulations of spiral galaxies

    International Nuclear Information System (INIS)

    Halle, A.

    2013-01-01

    The modelling of baryonic physics in numerical simulations of disc galaxies allows us to study the evolution of the different components, the physical state of the gas and the star formation. The present work aims at investigating in particular the role of the cold and dense molecular phase, which could play a role of gas reservoir in the outer galaxy discs, with low star formation efficiency. After a presentation of galaxies with a focus on spiral galaxies, their interstellar medium and dynamical evolution, we review the current state of hydrodynamical numerical simulations and the implementation of baryonic physics. We then present the simulations we performed. These include the cooling to low temperatures, and a molecular hydrogen component. The cooling functions we use include cooling by metals, for temperatures as low as 100 K, and cooling by H 2 due to collisions with H, He and other H 2 molecules. We use a TreeSPH type code that considers the stellar and gaseous components and black matter as particles. We especially test the impact of the presence of molecular hydrogen in simulations with several feedback efficiencies, and find that the molecular hydrogen allows in all cases some slow stellar formation to occur in the outer disc, with an effect on the vertical structure of the disc that is sensitive to the feedback efficiency. Molecular hydrogen is therefore able to play the role of gas reservoir in external parts of spiral galaxies, which accrete gas from cosmic filaments all along their lives

  9. The Neutrons for Science Facility at SPIRAL-2

    Science.gov (United States)

    Ledoux, X.; Aïche, M.; Avrigeanu, M.; Avrigeanu, V.; Audouin, L.; Balanzat, E.; Ban-détat, B.; Ban, G.; Barreau, G.; Bauge, E.; Bélier, G.; Bem, P.; Blideanu, V.; Borcea, C.; Bouffard, S.; Caillaud, T.; Chatillon, A.; Czajkowski, S.; Dessagne, P.; Doré, D.; Fallot, M.; Farget, F.; Fischer, U.; Giot, L.; Granier, T.; Guillous, S.; Gunsing, F.; Gustavsson, C.; Jacquot, B.; Jansson, K.; Jurado, B.; Kerveno, M.; Klix, A.; Landoas, O.; Lecolley, F. R.; Lecouey, J. L.; Majerle, M.; Marie, N.; Materna, T.; Mrazek, J.; Negoita, F.; Novak, J.; Oberstedt, S.; Oberstedt, A.; Panebianco, S.; Perrot, L.; Plompen, A. J. M.; Pomp, S.; Ramillon, J. M.; Ridikas, D.; Rossé, B.; Rudolf, G.; Serot, O.; Simakov, S. P.; Simeckova, E.; Smith, A. G.; Sublet, J. C.; Taieb, J.; Tassan-Got, L.; Tarrio, D.; Takibayev, A.; Thfoin, I.; Tsekhanovich, I.; Varignon, C.

    2014-05-01

    The Neutrons For Science (NFS) facility is a component of SPIRAL-2 laboratory under construction at Caen (France). SPIRAL-2 is dedicated to the production of high intensity Radioactive Ions Beams (RIB). It is based on a high-power linear accelerator (LINAG) to accelerate deuterons beams in order to produce neutrons by breakup reactions on a C converter. These neutrons will induce fission in 238U for production of radioactive isotopes. Additionally to the RIB production, the proton and deuteron beams delivered by the accelerator will be used in the NFS facility. NFS is composed of a pulsed neutron beam and irradiation stations for cross-section measurements and material studies. The beams delivered by the LINAG will allow producing intense neutron beams in the 100 keV-40 MeV energy range with either a continuous or quasi-mono-energetic spectrum. At NFS available average fluxes will be up to 2 orders of magnitude higher than those of other existing time-of-flight facilities in the 1 MeV - 40 MeV range. NFS will be a very powerful tool for fundamental physics and application related research in support of the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors. The facility and its characteristics are described, and several examples of the first potential experiments are presented.

  10. A Reconfigurable Spiral Antenna for Adaptive MIMO Systems

    Directory of Open Access Journals (Sweden)

    Cetiner Bedri A.

    2005-01-01

    Full Text Available We present a reconfigurable spiral antenna for use in adaptive MIMO systems. The antenna is capable of changing the sense of polarization of the radiated field. It is fabricated by using an RF-MEMS technology compatible with microwave laminate substrates developed within the author's group. The proposed antenna structure is built on a number of rectangular-shaped bent metallic strips interconnected to each other with RF-MEMS actuators. Two senses of polarization, RHCP and LHCP, are achieved by configuring the physical structure of the antenna, that is , by changing the winding sense of the spiral, through judicious activation of MEM actuators. The fabrication process for the monolithic integration of MEM actuators with bent microstrip pixels on RO4003-FR4 microwave laminate substrate is described. The measured and calculated radiation and impedance characteristics of the antenna are given. The operating frequency of the presented antenna design can easily be adjusted to be compatible with popular IEEE networking standards such as 802.11a.

  11. A Reconfigurable Spiral Antenna for Adaptive MIMO Systems

    Directory of Open Access Journals (Sweden)

    Qian JY

    2005-01-01

    Full Text Available We present a reconfigurable spiral antenna for use in adaptive MIMO systems. The antenna is capable of changing the sense of polarization of the radiated field. It is fabricated by using an RF-MEMS technology compatible with microwave laminate substrates developed within the author's group. The proposed antenna structure is built on a number of rectangular-shaped bent metallic strips interconnected to each other with RF-MEMS actuators. Two senses of polarization, RHCP and LHCP, are achieved by configuring the physical structure of the antenna, that is, by changing the winding sense of the spiral, through judicious activation of MEM actuators. The fabrication process for the monolithic integration of MEM actuators with bent microstrip pixels on RO4003-FR4 microwave laminate substrate is described. The measured and calculated radiation and impedance characteristics of the antenna are given. The operating frequency of the presented antenna design can easily be adjusted to be compatible with popular IEEE networking standards such as 802.11a.

  12. Optical and electrical properties of a spiral LED filament

    Science.gov (United States)

    Wang, Liping; Zou, Jun; Yang, Bobo; Li, Wenbo; Li, Yang; Shi, Mingming; Zhu, Wei; Zhang, Canyun; Wang, Fengchao; Lin, Yujie

    2018-02-01

    This paper introduces a new type of spiral white light-emitting diodes (WLED) filament with high luminous efficiency and uniform optical performance. The optical and thermal properties of the flexible filament were investigated at different stretching heights, namely 0, 1, 2, and 3 cm. The results indicated that the filament showed the best optical characteristics at the stretching height of 2 cm, because of good heat dissipation. In addition, the radiation temperature of the filament was inversely proportional to the output luminous flux. The reliability of the filament at a stretching height of 2 cm was also evaluated after 1000 h of use. The result demonstrated that the luminous flux decay of the bulb was only 0.85%. The flexible spiral WLED filament exhibiting high luminous flux and good reliability could be adapted to promote industrial development in the near future. Project supported by the National Nature Science Foundation of China (No. 51302171), the Science and Technology Commission of Shanghai Municipality (CN) (No. 14500503300), the Shanghai Municipal Alliance Program (No. Lm201547), the Shanghai Cooperative Project (No. ShanghaiCXY-2013-61), and the Jiashan County Technology Program (No. 20141316).

  13. Decametre scale, spiral-shaped landforms in Elysium Planitia, Mars

    Science.gov (United States)

    Balme, M. R.; Gallagher, C.

    2012-04-01

    We present the discovery of a new type of landform that is apparently confined to one or two locations in western Elysium Planitia, Mars. In planview, these landforms consist of spirals, a few tens of metres across, defined by low furrows and ridges. They appear singly or in loose groups or chains and are generally double-armed with a visual similarity to Kelvin-Helmholtz instability forms. About 100 examples have been found, over 90% of which occur in a single image. Almost all the examples seen have "anti-clockwise" rotation (from the edge to the centre); less than a fifth spiral the other way. The spirals are found only in the polygonised elements of a terrain type known as Platy-Ridged-Polygonised (PRP) terrain. This distinctive surface displays a tripartite morphology comprising: 1) well-defined, kilometre-scale plates of rubbly material (clast-sizes up to a few meters in diameters), 2) complex patterns of sinuous to sub-linear rubbly ridges that are often many kilometres long, less than a few tens of metres across and less than a few metres in height, and 3) clast-free zones between the plates that display decametre scale polygonally patterned ground defined by networks of furrows and grooves. PRP terrain appears to represent the "frozen" remnants of a once liquid medium: it is extremely flat with margins defining an equipotential surface; infills craters and drapes low relief terrain; can be traced up through the 300 km long Athabasca Vallis outflow channel to a source region consisting of a pair of large (km-wide) fractures called the Cerberus Fossae. The origin of the PRP material is debated: some authors favour extremely fluid, voluminous and turbulently emplaced lavas (e.g. Keszthelyi et al., Geochem. Geophys. Geosys., 2003), others argue that this material represents a debris-covered relict frozen sea or ocean (e.g. Murray et al., Nature, 2005). The spirals, which are visible only in HiRISE images with sub-metre spatial resolution, have been observed in

  14. Spiraling Edge: Fast Surface Reconstruction from Partially Organized Sample Points

    Energy Technology Data Exchange (ETDEWEB)

    Angel, Edward; Crossno, Patricia

    1999-07-12

    Many applications produce three-dimensional points that must be further processed to generate a surface. Surface reconstruction algorithms that start with a set of unorganized points are extremely time-consuming. Sometimes, however, points are generated such that there is additional information available to the reconstruction algorithm. We present Spiraling Edge, a specialized algorithm for surface reconstruction that is three orders of magnitude faster than algorithms for the general case. In addition to sample point locations, our algorithm starts with normal information and knowledge of each point's neighbors. Our algorithm produces a localized approximation to the surface by creating a star-shaped triangulation between a point and a subset of its nearest neighbors. This surface patch is extended by locally triangulating each of the points along the edge of the patch. As each edge point is triangulated, it is removed from the edge and new edge points along the patch's edge are inserted in its place. The updated edge spirals out over the surface until the edge encounters a surface boundary and stops growing in that direction, or until the edge reduces to a small hole that is filled by the final triangle.

  15. Multislice spiral computed tomography imaging in congenital inner ear malformations.

    Science.gov (United States)

    Ma, Hui; Han, Ping; Liang, Bo; Tian, Zhi-liang; Lei, Zi-qiao; Kong, Wei-jia; Feng, Gan-sheng

    2008-01-01

    The purpose of this study is to evaluate the usefulness of multislice spiral computed tomography (CT) in the diagnosis of congenital inner ear malformations. Forty-four patients with sensorineural hearing loss were examined on a Somatom Sensation 16 (Siemens) CT scanner. The 3-dimensional reconstructions and multiplanar reformation (MPR) were performed using the volume-rendering technique (VRT) on the workstation. Of the 44 patients examined for this study, 25 patients were found to be normal and 19 patients (36 ears) were diagnosed with congenital inner ear malformations. Of the malformations, the axial, MPR, and VRT images can all display the site and degree in 33 of the ears. Volume-rendering technique images were superior to the axial images in displaying the malformations in 3 ears with small lateral semicircular canal malformations. The common malformations were Michel deformity (1 ear), common cavity deformity (3 ears), incomplete partition I (3 ears), incomplete partition II (Mondini deformity) (5 ears), vestibular and semicircular canal malformations (14 ears), enlarged vestibular aqueduct (16 ears, 6 of which had other malformations), and internal auditory canal malformation (8 ears, all accompanied by other malformations). Multislice spiral CT allows a comprehensively assessment of various congenital inner ear malformations through high-quality MPR and VRT reconstructions. Volume-rendering technique images can display the site and degree of the malformation 3-dimensionally and intuitionisticly. This is very useful to the cochlear implantation.

  16. HF electronic tubes. Technologies, grid tubes and klystrons

    International Nuclear Information System (INIS)

    Lemoine, Th.

    2009-01-01

    This article gives an overview of the basic technologies of electronic tubes: cathodes, electronic optics, vacuum and high voltage. Then the grid tubes, klystrons and inductive output tubes (IOT) are introduced. Content: 1 - context and classification; 2 - electronic tube technologies: cathodes, electronic optics, magnetic confinement (linear tubes), periodic permanent magnet (PPM) focussing, collectors, depressed collectors; 3 - vacuum technologies: vacuum quality, surface effects and interaction with electrostatic and RF fields, secondary emission, multipactor effect, thermo-electronic emission; 4 - grid tubes: operation of a triode, tetrodes, dynamic operation and classes of use, 'common grid' and 'common cathode' operation, ranges of utilisation and limitations, operation of a tetrode on unadjusted load, lifetime of a tetrode, uses of grid tubes; 5 - klystrons: operation, impact of space charge, multi-cavity klystrons, interaction efficiency, extended interaction klystrons, relation between interaction efficiency, perveance and efficiency, ranges of utilization and power limitations, multi-beam klystrons and sheet beam klystrons, operation on unadjusted load, klystron band pass and lifetime, uses; 6 - IOT: principle of operation, ranges of utilisation and limitations, interaction efficiency and depressed collector IOT, IOT lifetime and uses. (J.S.)

  17. Salicylate selectively kills cochlear spiral ganglion neurons by paradoxically up-regulating superoxide.

    Science.gov (United States)

    Deng, Lili; Ding, Dalian; Su, Jiping; Manohar, Senthilvelan; Salvi, Richard

    2013-10-01

    Aspirin and its active ingredient salicylate are potent antioxidants that have been reported to be neuro- and otoprotective. However, when consumed in large quantities, these drugs can cause temporary hearing loss and tinnitus. Moreover, recent studies indicate that after several days of treatment, salicylate selectively destroys the spiral ganglion neurons and auditory nerve fibers that relay sounds from the sensory hair cells to the brain. Why salicylate selectively damages spiral ganglion neurons while sparing the hair cells and supports cells is unclear. Here we show that high dose of salicylate trigger an apoptotic response in spiral ganglion neurons characterized morphologically by soma shrinkage and nuclear condensation and fragmentation plus activation of extrinsic initiator caspase-8 and intrinsic initiator caspase-9 several days after the onset of drug treatment. Salicylate treatment triggered an upsurge in the toxic superoxide radical only in spiral ganglion neurons, but not in neighboring hair cells and support cells. Mn TMPyP pentachloride, a cell permeable scavenger of superoxide blocked the expression of superoxide staining in spiral ganglion neurons and almost completely blocked the damage to the nerve fibers and spiral ganglion neurons. NMDA receptor activation is known to increase neuronal superoxide levels. Since NMDA receptors are mainly found on spiral ganglion neurons and since salicylate enhances NMDA receptor currents, the selective killing of spiral ganglion neurons is likely a consequence of enhanced and sustained activation of NMDA receptors by salicylate.

  18. The study of the structural stability of the spiral laser beams propagation through inhomogeneous phase medium

    Science.gov (United States)

    Zinchik, Alexander A.; Muzychenko, Yana B.

    2015-06-01

    This paper discusses theoretical and experimental results of the investigation of light beams that retain their intensity structure during propagation and focusing. Spiral laser beams are a family of laser beams that preserve the structural stability up to scale and rotation with the propagation. Properties of spiral beams are of practical interest for laser technology, medicine and biotechnology. Researchers use a spiral beams for movement and manipulation of microparticles. Functionality laser manipulators can be significantly enhanced by using spiral beams whose intensity remains invariable. It is well known, that these beams has non-zero orbital angular momentum. Spiral beams have a complicated phase distribution in cross section. In this paper we investigate the structural stability of the laser beams having a spiral phase structure by passing them through an inhomogeneous phase medium. Laser beam is passed through a medium is characterized by a random distribution of phase in the range 0..2π. The modeling was performed using VirtualLab 5.0 (manufacturer LightTrans GmbH). Compared the intensity distribution of the spiral and ordinary laser beam after the passage of the inhomogeneous medium. It is shown that the spiral beams exhibit a significantly better structural stability during the passage phase heterogeneous environments than conventional laser beams. The results obtained in the simulation are tested experimentally. Experimental results show good agreement with the theoretical results.

  19. Unraveling the unsustainability spiral in sub-Saharan Africa: an agent based modeling approach

    NARCIS (Netherlands)

    Hofwegen, van G.; Becx, G.A.; Broek, van den J.A.; Koning, N.B.J.

    2007-01-01

    Sub-Saharan Africa is trapped in a complex unsustainability spiral with demographic, biophysical, technical and socio-political dimensions. Unravelling the spiral is vital to perceive which policy actions are needed to reverse it and initiate sustainable pro-poor growth. The article presents an

  20. Comparison of spiral CT angiography vs digital subtraction angiography in the evaluation of living kidney donors

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    2002-01-01

    Full Text Available Recent reports suggest that spiral computed tomographic (CT angiography could replace conventional angiogra-phy and intravenous urography (IVU for the assessment of potential live kidney donors. The purpose of this study was to assess the accuracy of spiral CT in kidney donor workup. 10 consecutive renal donors had IVU, percutane-ous transfemoral selective renal angiography and spiral CT angiography between January and March 2001. The spiral CT and renal angiograms were assessed independ-ently by two radiologists. The number of renal arteries, pres-ence or absence of renal artery stenoses and associated parenchymal abnormalities were assessed. A total of 27 renal arteries were detected. Transverse scans viewed in a tine loop format with maximum intensity projection and shaded surface display detected all 27 vessels. All 27 ves-sels were detected by conventional catheter angiography. A simple renal cyst was noted in both spiral CT and con-ventional angiogram. Venous anatomy including a retroaortic renal vein was visualized in spiral CT angiogram but not visualized by conventional angiography. Spiral CT angiography performed as an outpatient procedure is less invasive, less expensive, and provides good images of the arterial and venous anatomy in addition to the visualiza-tion of the other abdominal viscera. A plain X-ray of the abdomen was taken 15 rains after injection of contrast to acquire an IVU like image. Spiral CT angiography has the potential to replace conventional catheter angiography and IVU in the assessment of renal donors.

  1. Interleaved spiral-in/out with application to functional MRI (fMRI).

    Science.gov (United States)

    Law, Christine S; Glover, Gary H

    2009-09-01

    The conventional spiral-in/out trajectory samples k-space sufficiently in the spiral-in path and sufficiently in the spiral-out path to enable creation of separate images. We propose an "interleaved spiral-in/out" trajectory comprising a spiral-in path that gathers one half of the k-space data, and a complimentary spiral-out path that gathers the other half. The readout duration is thereby reduced by approximately half, offering two distinct advantages: reduction of signal dropout due to susceptibility-induced field gradients (at the expense of signal-to-noise ratio [SNR]), and the ability to achieve higher spatial resolution when the readout duration is identical to the conventional method. Two reconstruction methods are described; both involve temporal filtering to remove aliasing artifacts. Empirically, interleaved spiral-in/out images are free from false activation resulting from signal pileup around the air/tissue interface, which is common in the conventional spiral-out method. Comparisons with conventional methods using a hyperoxia stimulus reveal greater frontal-orbital activation volumes but a slight reduction of overall activation in other brain regions.

  2. Spiraling down the river continuum: stream ecology and the U-shaped curve

    Science.gov (United States)

    Jackson R. Webster

    2007-01-01

    The spiraling concept provides an explicit approach to modeling the longitudinal linkages within a river continuum. I developed a spiraling-based model for particulate organic C dynamics in the Little Tennessee River to synthesize existing data and to illustrate our current understanding of ecosystem processes in river ecosystems. The Little Tennessee River is a medium...

  3. Geometric Aspects and Testing of the Galactic Center Distance Determination from Spiral Arm Segments

    Science.gov (United States)

    Nikiforov, I. I.; Veselova, A. V.

    2018-02-01

    We consider the problem of determining the geometric parameters of a Galactic spiral arm from its segment by including the distance to the spiral pole, i.e., the distance to the Galactic center ( R 0). The question about the number of points belonging to one turn of a logarithmic spiral and defining this spiral as a geometric figure has been investigated numerically and analytically by assuming the direction to the spiral pole (to the Galactic center) to be known. Based on the results obtained, in an effort to test the new approach, we have constructed a simplified method of solving the problem that consists in finding the median of the values for each parameter from all possible triplets of objects in the spiral arm segment satisfying the condition for the angular distance between objects. Applying the method to the data on the spatial distribution of masers in the Perseus and Scutum arms (the catalogue by Reid et al. (2014)) has led to an estimate of R 0 = 8.8 ± 0.5 kpc. The parameters of five spiral arm segments have been determined from masers of the same catalogue. We have confirmed the difference between the spiral arms in pitch angle. The pitch angles of the arms revealed by masers are shown to generally correlate with R 0 in the sense that an increase in R 0 leads to a growth in the absolute values of the pitch angles.

  4. Computation of the response functions of spiral waves in active media.

    Science.gov (United States)

    Biktasheva, I V; Barkley, D; Biktashev, V N; Bordyugov, G V; Foulkes, A J

    2009-05-01

    Rotating spiral waves are a form of self-organization observed in spatially extended systems of physical, chemical, and biological natures. A small perturbation causes gradual change in spatial location of spiral's rotation center and frequency, i.e., drift. The response functions (RFs) of a spiral wave are the eigenfunctions of the adjoint linearized operator corresponding to the critical eigenvalues lambda=0,+/-iomega. The RFs describe the spiral's sensitivity to small perturbations in the way that a spiral is insensitive to small perturbations where its RFs are close to zero. The velocity of a spiral's drift is proportional to the convolution of RFs with the perturbation. Here we develop a regular and generic method of computing the RFs of stationary rotating spirals in reaction-diffusion equations. We demonstrate the method on the FitzHugh-Nagumo system and also show convergence of the method with respect to the computational parameters, i.e., discretization steps and size of the medium. The obtained RFs are localized at the spiral's core.

  5. Integral split ring resonator loaded with drift tubes and RF quadrupoles

    International Nuclear Information System (INIS)

    Fang, J.X.; Chen, C.E.

    1985-01-01

    In order to improve the mechanical stability, the coupled split ring (also spirals) resonators, loaded either with drift tubes or RF Quadrupoles, are integrated together through conducting bars. Investigations on 1/2 and full scale models (50 cm in tank diameter) show considerable improvement on the overall rigidity of the structure while keeping the RF efficiency high. The operating frequency can be greatly reduced by the integration to 24 and 14 MHz for loading with drift tubes and RFQ respectively. The integration also flattens the accelerating voltage distribution and enhances the mode separation and thus facilitates the assembling and commissioning of the accelerating structure. An equivalent circuit of the integral split ring, which agrees well with the experiments, has been developed

  6. The different star formation histories of blue and red spiral and elliptical galaxies

    Science.gov (United States)

    Tojeiro, Rita; Masters, Karen L.; Richards, Joshua; Percival, Will J.; Bamford, Steven P.; Maraston, Claudia; Nichol, Robert C.; Skibba, Ramin; Thomas, Daniel

    2013-06-01

    We study the spectral properties of intermediate mass galaxies (M* ˜ 1010.7 M⊙) as a function of colour and morphology. We use Galaxy Zoo to define three morphological classes of galaxies, namely early types (ellipticals), late-type (disc-dominated) face-on spirals and early-type (bulge-dominated) face-on spirals. We classify these galaxies as blue or red according to their Sloan Digital Sky Survey (SDSS) g - r colour and use the spectral fitting code Versatile Spectral Analyses to calculate time-resolved star formation histories, metallicity and total starlight dust extinction from their SDSS fibre spectra. We find that red late-type spirals show less star formation in the last 500 Myr than blue late-type spirals by up to a factor of 3, but share similar star formation histories at earlier times. This decline in recent star formation explains their redder colour: their chemical and dust content are the same. We postulate that red late-type spirals are recent descendants of blue late-type spirals, with their star formation curtailed in the last 500 Myr. The red late-type spirals are however still forming stars ≃17 times faster than red ellipticals over the same period. Red early-type spirals lie between red late-type spirals and red ellipticals in terms of recent-to-intermediate star formation and dust content. Therefore, it is plausible that these galaxies represent an evolutionary link between these two populations. They are more likely to evolve directly into red ellipticals than red late-type spirals, which show star formation histories and dust content closer to blue late-type spirals. Blue ellipticals show similar star formation histories as blue spirals (regardless of type), except that they have formed less stars in the last 100 Myr. However, blue ellipticals have different dust content, which peaks at lower extinction values than all spiral galaxies. Therefore, many blue ellipticals are unlikely to be descendants of blue spirals, suggesting there may

  7. Pulsed Drift Tube Accelerator

    International Nuclear Information System (INIS)

    Faltens, A.

    2004-01-01

    The pulsed drift-tube accelerator (DTA) concept was revived by Joe Kwan and John Staples and is being considered for the HEDP/WDM application. It could be used to reach the full energy or as an intermediate accelerator between the diode and a high gradient accelerator such as multi-beam r.f. In the earliest LBNL HIF proposals and conceptual drivers it was used as an extended injector to reach energies where an induction linac with magnetic quadrupoles is the best choice. For HEDP, because of the very short pulse duration, the DTA could provide an acceleration rate of about 1MV/m. This note is divided into two parts: the first, a design based on existing experience; the second, an optimistic extrapolation. The first accelerates 16 parallel K + beams at a constant line charge density of 0.25(micro) C/m per beam to 10 MeV; the second uses a stripper and charge selector at around 4MeV followed by further acceleration to reach 40 MeV. Both benefit from more compact sources than the present 2MV injector source, although that beam is the basis of the first design and is a viable option. A pulsed drift-tube accelerator was the first major HIF experiment at LBNL. It was designed to produce a 2(micro)s rectangular 1 Ampere C s + beam at 2MeV. It ran comfortably at 1.6MeV for several years, then at lower voltages and currents for other experiments, and remnants of that experiment are in use in present experiments, still running 25 years later. The 1A current, completely equivalent to 1.8A K + , was chosen to be intermediate between the beamlets appropriate for a multi-beam accelerator, and a single beam of, say, 10A, at injection energies. The original driver scenarios using one large beam on each side of the reactor rapidly fell out of favor because of the very high transverse and longitudinal fields from the beam space charge, circa 1MV/cm and 250 kV/cm respectively, near the chamber and because of aberrations in focusing a large diameter beam down to a 1mm radius spot at a

  8. Experimental Investigation of the Spiral Structure of a Magnetic Capsule Endoscope

    Directory of Open Access Journals (Sweden)

    Wanan Yang

    2016-06-01

    Full Text Available Fitting a wireless capsule endoscope (WCE with a navigation feature can maximize its functional benefits. The rotation of a spiral-type capsule can be converted to translational motion. The study investigated how the spiral structure and rotational speed affected the capsule's translation speed. A hand-held instrument, including two permanent magnets, a stepper motor, a controller and a power supplier, were designed to generate rotational magnetic fields. The surfaces of custom-built permanent magnet rings magnetized radially were mounted in spiral lines with different lead angles and diameters, acting as mock-up capsules. The experimental results demonstrate that the rotational speed of the magnetic field and the spiral have significant effects on the translational speed of a capsule. The spiral line with a larger lead angle and the rotating magnetic field with a higher speed can change the capsule's rotation into a translational motion more efficiently in the intestine.

  9. Interacting spiral waves in the Oregonator model of the light-sensitive Belousov-Zhabotinskii reaction

    Science.gov (United States)

    Schebesch, I.; Engel, H.

    1999-12-01

    We study the interaction of meandering spiral waves within the framework of a modified Oregonator model for the light-sensitive Belousov-Zhabotinskii medium. In this medium the local excitation threshold can be controlled by varying the intensity of incident light. At low as well as sufficiently high light intensity we find stable axis-symmetric bound states consisting of two counterrotating spirals. At intensity values in between, spiral pairs undergo a symmetry-breaking instability, leading to one spiral suppressing and expelling the other. To avoid the instability, we consider a spiral wave interacting with its mirror image close to a plane boundary impermeable to diffusion. The drift velocity and the drift direction of those pseudobound states parallel to the boundary are strongly influenced by the light intensity.

  10. Dynamics of spiral waves in excitable media subjected to external periodic forcing

    Science.gov (United States)

    Schrader, A.; Braune, M.; Engel, H.

    1995-07-01

    We provide a survey of the behavior of meandering spiral waves in excitable media under periodic modulation of excitability. Model calculations were performed in a modified Oregonator model for the photosensitive Belousov-Zhabotinsky reaction. The spiral's dynamic is followed by its tip motion. We find mode locking if the path curvature period is a rational multiple of the modulation period and resonance response of the spiral's rotation period. A general ordering structure in terms of the Farey tree is observed. The complex motion of the spiral's tip is found to be composed of harmonics of the modulation period. For large forcing amplitudes we observe an overlap of entrainment bands resulting in bi- stable behavior and in the breakup of the spiral at the end of the major entrainment band.

  11. A new local thickening reverse spiral origami thin-wall construction for improving of energy absorption

    Science.gov (United States)

    Kong, C. H.; Zhao, X. L.; Hagiwara, I. R.

    2018-02-01

    As an effective and representative origami structure, reverse spiral origami structure can be capable to effectively take up energy in a crash test. The origami structure has origami creases thus this can guide the deformation of structure and avoid of Euler buckling. Even so the origami creases also weaken the support force and this may cut the absorption of crash energy. In order to increase the supporting capacity of the reverse spiral origami structure, we projected a new local thickening reverse spiral origami thin-wall construction. The reverse spiral origami thin-wall structure with thickening areas distributed along the longitudinal origami crease has a higher energy absorption capacity than the ordinary reverse spiral origami thin-wall structure.

  12. Water-storage-tube systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hemker, P.

    1981-12-24

    Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

  13. Conditioning and breakdown phenomena in accelerator tubes

    International Nuclear Information System (INIS)

    Skorka, S.J.

    1979-01-01

    Important breakdown mechanisms in accelerator tubes are reviewed, and discharge phenomena in NEC tubes are deduced from the surface appearance of the electrodes and insulators of a used tube. Microphotos of these surfaces are shown

  14. Eddy current signal comparison for tube identification

    Science.gov (United States)

    Glass, S. W.; Vojvodic, R.

    2015-03-01

    Inspection of nuclear power plant steam generator tubes is required to justify continued safe plant operation. The steam generators consist of thousands of tubes with nominal diameters of 15 to 22mm, approximately 1mm wall thickness, and 20 to 30m in length. The tubes are inspected by passing an eddy current probe through the tubes from tube end to tube end. It is critical to know exactly which tube identification (row and column) is associated with each tube's data. This is controlled by a precision manipulator that provides the tube ID to the eddy current system. Historically there have been some instances where the manipulator incorrectly reported the tube ID. This can have serious consequences including lack of inspection of a tube, or if a pluggable indication is detected, the tube is likely to be mis-plugged thereby risking a primary to secondary leak.

  15. Multislice spiral CT of the paranasal sinuses; Mehrschicht-Spiral-CT der Nasennebenhoehlen: Erste Erfahrungen unter besonderer Beruecksichtigung der Strahlenexposition

    Energy Technology Data Exchange (ETDEWEB)

    Dammann, F.; Bode, A.; Heuschmid, M.; Kopp, A.; Georg, C.; Pereira, P.L.; Claussen, C.D. [Tuebingen Univ. (Germany). Radiologische Universitaetsklinik

    2000-08-01

    Purpose: To evaluate the potential of multislice CT in the diagnosis of the paranasal sinuses. Methods: Dose measurements were performed exposing an Alderson Rando phantom in a four-slice spiral CT (MS-CT) while applying a variety of scan parameters. Additionally, 30 consecutive patients underwent a transversal examination by the MS-CT using 1/1/3.5/0.5 mm spiral parameters and an additional transversal or coronal scan on a conventional single slice spiral CT (SS-CT) with 2/3/1 mm. Coronal reformations of the MS-CT were compared with the primary coronal SS-CT, or coronal reformations of the transversal SS-CT, respectively, with regard to image quality and depiction of relevant anatomical details of the region. Results: Superficial exposure values at the level of the eye lenses as well as for the thyroid gland were superior for MS-CT (3.62 mGy, and 0.12 mGy, resp.) as compared to SS-CT (2.96 mGy, and 0.07 mGy). Image quality was equal or superior for MS-CT as compared to SS-CT in all but one case. Drawbacks of SS-CT, such as dental amalgam artifacts, stair step artifacts or partial volume artifacts did not notably affect the coronal reformations of MS-CT. Conclusions: MS-CT seems to have the potential to replace primary coronal CT of the paranasal sinuses without any loss of image quality, but may even improve the overall diagnostic value. Radiation doses may still have to be reduced. (orig.) [German] Ziel: Erprobung eines Multislice-CT (MS-CT) zur Diagnostik der Nasennebenhoehlen (NNH). Methode: An einem Alderson Rando Phantom wurden Dosismessungen bei der Spiral-CT der NNH mit einem Mehrschicht-CT (MS-CT) unter Verwendung unterschiedlicher Scanparameter durchgefuehrt. Anschliessend wurden 30 konsekutive Patienten an dem MS-CT mit den Spiralparametern 1/1/3,5/0,5 mm und einem konventionellen Einzeilen Spiral-CT (SS-CT; 2/3/1 mm) untersucht. Die koronaren Rekonstruktionen der transversalen MS-CT wurden mit den koronaren Rekonstruktionen bzw. den primaeren koronaren

  16. mouseTube

    Science.gov (United States)

    Torquet, Nicolas; de Chaumont, Fabrice; Faure, Philippe; Bourgeron, Thomas; Ey, Elodie

    2016-01-01

    Ultrasonic vocalisation is a broadly used proxy to evaluate social communication in mouse models of neuropsychiatric disorders. The efficacy and robustness of testing these models suffer from limited knowledge of the structure and functions of these vocalisations as well as of the way to analyse the data. We created mouseTube , an open database with a web interface, to facilitate sharing and comparison of ultrasonic vocalisations data and metadata attached to a recording file. Metadata describe 1) the acquisition procedure, e.g ., hardware, software, sampling frequency, bit depth; 2) the biological protocol used to elicit ultrasonic vocalisations; 3) the characteristics of the individual emitting ultrasonic vocalisations ( e.g. , strain, sex, age). To promote open science and enable reproducibility, data are made freely available. The website provides searching functions to facilitate the retrieval of recording files of interest. It is designed to enable comparisons of ultrasonic vocalisation emission between strains, protocols or laboratories, as well as to test different analysis algorithms and to search for protocols established to elicit mouse ultrasonic vocalisations. Over the long term, users will be able to download and compare different analysis results for each data file. Such application will boost the knowledge on mouse ultrasonic communication and stimulate sharing and comparison of automatic analysis methods to refine phenotyping techniques in mouse models of neuropsychiatric disorders.

  17. X-ray tube

    International Nuclear Information System (INIS)

    Mayo, B.J.

    1980-01-01

    An x-ray tube in which the x-ray origin is scanned on a circle around the patient, comprises a ring-shaped anode, an electron beam travelling along a circular path being deflected onto the anode at the desired positions. The electron beam path may be in a plane parallel to the anode and perhaps at the same radius. It may be in the same plane as a transmission target/anode and at a greater radius. The anode should extend over at least 180 0 although it may extend to 360 0 . Electrostatic means may be provided to constrain the beam to the circular path and further electrostatic means deflect it to the anode of the beam and ensure it is focused at the point of incidence. Collimators provide a planar fan-shaped beam and the anode may be shaped to attenuate side lobes of the radiation. Electrode collects electrons not deflected. The focal regions may be adjacent or otherwise. Coils may provide periodic focusing to overcome space charge dispersion and dynamic adjustment of the focusing before deflection ensures focusing at target incidence. Focusing may be absent near the deflection region, and current in the coil section near the focal region should be zero. (author)

  18. Flux tubes at finite temperature

    Energy Technology Data Exchange (ETDEWEB)

    Cea, Paolo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Dipartimento di Fisica dell’Università di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cosmai, Leonardo [INFN, Sezione di Bari,Via G. Amendola 173, I-70126 Bari (Italy); Cuteri, Francesca; Papa, Alessandro [Dipartimento di Fisica, Università della Calabria & INFN-Cosenza,Ponte Bucci, cubo 31C, I-87036 Rende (Cosenza) (Italy)

    2016-06-07

    The chromoelectric field generated by a static quark-antiquark pair, with its peculiar tube-like shape, can be nicely described, at zero temperature, within the dual superconductor scenario for the QCD confining vacuum. In this work we investigate, by lattice Monte Carlo simulations of the SU(3) pure gauge theory, the fate of chromoelectric flux tubes across the deconfinement transition. We find that, if the distance between the static sources is kept fixed at about 0.76 fm ≃1.6/√σ and the temperature is increased towards and above the deconfinement temperature T{sub c}, the amplitude of the field inside the flux tube gets smaller, while the shape of the flux tube does not vary appreciably across deconfinement. This scenario with flux-tube “evaporation” above T{sub c} has no correspondence in ordinary (type-II) superconductivity, where instead the transition to the phase with normal conductivity is characterized by a divergent fattening of flux tubes as the transition temperature is approached from below. We present also some evidence about the existence of flux-tube structures in the magnetic sector of the theory in the deconfined phase.

  19. Borrmann type IV adenocarcinoma versus gastric lymphoma : spiral CT evaluation

    International Nuclear Information System (INIS)

    Seo, Bo Kyoung; Kim, Yun Hwan; Shin, Kue Hee; Hong, Suk Joo; Kim, Hong Weon; Park, Cheol Min; Chung, Kyoo Byung; Cho, Hyun Deuk

    1999-01-01

    To distinguish the spiral CT findings of Borrmann type IV adenocarcinoma from those of gastric lymphoma with diffuse gastric wall thickening. We retrospectively reviewed the spiral CT scans of 30 patients with Borrmann type IV adenocarcinoma and nine with gastric lymphoma with diffuse gastric wall thickening. In all patients the respective condition was pathologically confirmed by gastrectomy. CT scanning was performed after peroral administration of 500-700ml of water. A total of 120-140 ml bolus of nonionic contrast material was administered intravenously at a flow rate of 3 ml/sec and two-phase images were obtained at 35-45 sec(early phase) and 180 sec(delayed phase) after the start of bolus injection. Spiral CT was performed with 10mm collimation, 10mm/sec table feed and 10mm reconstruction. We evaluated the degree and homogeneity of enhancement of thickened entire gastric wall, and the enhancement pattern of gastric inner layer, as seen on early-phase CT scans. On early and delayed views, the thickness of gastric wall and the presence of perigastric fat infiltration were determined. The enhancement patterns of gastric inner layer were classified as either continuous or discontinuous thick enhancement, thin enhancement, or nonenhancement. The thickness of gastric wall was 1.2-3.5cm(mean 2.2cm) in cases of adenocarcinoma and 1.2-7.6cm(mean 4cm) in lymphoma. Perigastric fat infiltration was seen in 24 patients with adenocarcinoma(80%) and four with lymphoma(44%). In those with adenocarcinoma, the degree of enhancement of entire gastric wall was hyperdense in fifteen patients(50%) and isointense in eleven (37%). Seven patients with lymphoma(78%)showed hypodensity. In those with adenocarcinoma, continuous thick enhancement of gastric inner layer was seen in 18 patients(60%) and discontinuous thick enhancement in nine(30%). In lymphoma cases, no thick enhancement was observed. Thin enhancement of gastric inner layer was demonstrated in three patients with

  20. PEG tubes: dealing with complications.

    Science.gov (United States)

    Malhi, Hardip; Thompson, Rosie

    A percutaneous endoscopic gastronomy tube can be used to deliver nutrition, hydration and medicines directly into the patient's stomach. Patients will require a tube if they are unable to swallow safely, putting them at risk of aspiration of food, drink and medicines into their lungs. It is vital that nurses are aware of the complications that may arise when caring for a patient with a PEG tube. It is equally important that nurses know how to deal with these complications or from where tc seek advice. This article provides a quick troubleshooting guide to help nurses deal with complications that can arise with PEG feeding.