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Sample records for annuloplasty rings experience

  1. 21 CFR 870.3800 - Annuloplasty ring.

    Science.gov (United States)

    2010-04-01

    ...) Identification. An annuloplasty ring is a rigid or flexible ring implanted around the mitral or tricuspid heart valve for reconstructive treatment of valvular insufficiency. (b) Classification. Class II (special...

  2. Functional Tricuspid Regurgitation and Ring Annuloplasty Repair

    Directory of Open Access Journals (Sweden)

    William B. Weir, MD

    2018-01-01

    Full Text Available Functional tricuspid regurgitation (TR primarily arises from asymmetric dilation of the tricuspid annulus in the setting of right ventricular dysfunction and enlargement in response to left-sided myocardial and valvular abnormalities. Even if the TR is not severe at the time of mitral valve surgery, it can worsen and even appear late after successful mitral valve surgery, which portends a poor prognosis. Despite data demonstrating inferior outcomes in the presence of residual TR, surgical repair for functional TR remains underused. Acceptance of TR, in the presence of tricuspid annular dilation, may be unacceptable. Surgical repair should consist of placement of a rigid or semirigid annular ring, which has been shown to provide superior durability as compared with suture and flexible band techniques. Finally, percutaneous annuloplasty for correction of functional TR may allow treatment of patients with recurrent TR at high risk of reoperation.

  3. Mitral stenosis due to pannus overgrowth after rigid ring annuloplasty.

    Science.gov (United States)

    Oda, Takeshi; Kato, Seiya; Tayama, Eiki; Fukunaga, Shuji; Akashi, Hidetoshi; Aoyagi, Shigeaki

    2010-03-01

    Although mitral stenosis (MS) due to pannus overgrowth after mitral valve repair for rheumatic mitral regurgitation (MR) is not uncommon, it is extremely rare in relation to non-rheumatic mitral regurgitation. Whilst it has been suggested that the rigid annuloplasty ring induces pannus overgrowth in the same manner as the flexible ring, to date only in cases using the flexible ring has pannus formation been confirmed by a pathological examination after redo surgery. The case is described of a woman who had undergone mitral valve repair using a 28 mm rigid ring three years previously because of non-rheumatic MR, and subsequently suffered from MS due to pannus formation over the annuloplasty ring. To the present authors' knowledge, this is the first report of MS due to pannus formation after mitral valve repair using a rigid annuloplasty ring to treat non-rheumatic MR documented at reoperation.

  4. Mitral valve repair with adjustable ring annuloplasty.

    Science.gov (United States)

    Andreas, Martin; Haberl, Thomas; Paul Werner, Paul Werner; Guri, Jani; Kocher, Alfred; Hamza, Ouafa; Podesser, Bruno; Laufer, Guenther

    2018-02-28

    We demonstrate the technical aspects of a novel adjustable mitral ring. This new ring was implanted in a female landrace pig, for training and educational purposes. It can be adjusted independently in the P1, P2 and P3 segments, if required, to treat  recurrent mitral regurgitation, and this is a key difference to comparable devices. The first-in-man implantation is anticipated in the near future. © The Author 2016. Published by MMCTS on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  5. Remodeling Mitral Annuloplasty Ring Concept with Preserved Dynamics of Annular Height

    DEFF Research Database (Denmark)

    Skov, Søren N; Røpcke, Diana M; Tjørnild, Marcell J

    2017-01-01

    BACKGROUND: The configuration of the native annulus changes from nearly flat in the diastolic phase to saddle-shaped in the systolic phase. The present study was conducted to test a novel remodeling annuloplasty ring with built-in septal-lateral fixation and commissural axial flexibility so...... as to maintain the change in annular saddle shape. The study aim was to evaluate the in-vivo biomechanical performance of the novel annuloplasty ring, compared with the native valve and a semi-rigid and rigid annuloplasty ring. METHODS: All measurements were performed in vivo using a porcine model. A total of 28...... pigs (bodyweight ca. 80 kg) were randomized to four groups: (i) with no ring; (ii) with a novel remodeling ring; (iii) with a semi-rigid ring (Physio I Ring, Edwards Lifesciences); and (iv) with a rigid ring (Classic Annuloplasty Ring, Edwards Lifesciences). Force measurements were performed using...

  6. Repair for mitral stenosis due to pannus formation after Duran ring annuloplasty.

    Science.gov (United States)

    Song, Seunghwan; Cho, Seong Ho; Yang, Ji-Hyuk; Park, Pyo Won

    2010-12-01

    Mitral stenosis after mitral repair with using an annuloplasty ring is not common and it is almost always due to pannus formation. Mitral valve replacement was required in most of the previous cases of pannus covering the mitral valve leaflet, which could not be stripped off without damaging the valve leaflets. In two cases, we removed the previous annuloplasty ring and pannus without leaflet injury, and we successfully repaired the mitral valve. During the follow-up of 4 months and 39 months respectively, we observed improvement of the patients' symptoms and good valvular function. Redo mitral repair may be a possible method for treating mitral stenosis due to pannus formation after ring annuloplasty. Copyright © 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  7. Mitral valve stenosis caused by abnormal pannus extension over the prosthetic ring and leaflets after Duran ring mitral annuloplasty.

    Science.gov (United States)

    Yunoki, Junji; Minato, Naoki; Katayama, Yuji; Sato, Hisashi

    2009-01-01

    We treated a 61-year-old woman with mitral stenosis caused by pannus formation after Duran ring annuloplasty. Pannus overgrowth on the ring with extension onto both leaflets narrowed the mitral orifice and severely restricted the mobility of the valve leaflets. Mitral valve replacement with a St. Jude Medical mechanical heart valve prosthesis was successfully performed, and the postoperative course was uneventful. Patients undergoing Duran ring annuloplasty should be followed up with the consideration of possible mitral stenosis caused by pannus extension, as the cause for pannus formation remains unclear.

  8. Midterm follow up after Ebstein's anomaly repair augmented with tricuspid annuloplasty ring

    Directory of Open Access Journals (Sweden)

    Sherif Eliwa

    2017-06-01

    Conclusions: Augmentation of the tricuspid valve repair with annuloplasty ring can be performed with low mortality and morbidity. Early and mid-term follow-up showed clinical improvement in the majority of patients, low incidence of reoperations, and no need for tricuspid valve replacement (TVR.

  9. Early results after implantation of a new geometric annuloplasty ring for aortic valve repair.

    Science.gov (United States)

    Mazzitelli, Domenico; Nöbauer, Christian; Rankin, J Scott; Badiu, Catalin C; Krane, Markus; Crooke, Philip S; Cohn, William E; Opitz, Anke; Schreiber, Christian; Lange, Rüdiger

    2013-01-01

    Aortic valve repair is associated with fewer long-term valve-related complications as compared with valve replacement, and repair is being performed increasingly. A current problem is the lack of a geometric annuloplasty ring to facilitate reconstruction. This paper describes the first clinical application of such a device designed to permanently restore physiologic annular size and geometry during aortic valve repair. Based on mathematical studies of human cadaver valves, as well as computed tomography angiographic analyses of awake patients with normal valves, a three-dimensional annuloplasty ring has been developed, consisting of low-profile, one-piece titanium construction and Dacron cloth covering. The ring design incorporates 2:3 elliptical base geometry and 10-degree outwardly flaring subcommissural posts. Appropriately sized rings were implanted in 5 patients with severe aortic insufficiency due to annular dilation and anatomic leaflet defects. The rings restored annular geometry and facilitated leaflet repairs in all patients. Each recovered excellent valve function with minimal residual leak. All patients convalesced uneventfully, were discharged within 7 days after surgery, and continue with stable valve function as long as 6 months after implantation. Initial clinical application of a geometric aortic annuloplasty ring was associated with excellent device performance and perhaps better repairs. Further clinical series and patient follow-up should identify potential benefits of the device, including improved applicability and stability of aortic valve repair. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  10. Tricuspid annuloplasty with the MC3 ring and septal plication technique.

    Science.gov (United States)

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

    2015-01-01

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

  11. Annular dynamics of memo3D annuloplasty ring evaluated by 3D transesophageal echocardiography.

    Science.gov (United States)

    Nishi, Hiroyuki; Toda, Koichi; Miyagawa, Shigeru; Yoshikawa, Yasushi; Fukushima, Satsuki; Yoshioka, Daisuke; Sawa, Yoshiki

    2018-04-01

    We assessed the mitral annular motion after mitral valve repair with the Sorin Memo 3D® (Sorin Group Italia S.r.L., Saluggia, Italy), which is a unique complete semirigid annuloplasty ring intended to restore the systolic profile of the mitral annulus while adapting to the physiologic dynamism of the annulus, using transesophageal real-time three-dimensional echocardiography. 17 patients (12 male; mean age 60.4 ± 14.9 years) who underwent mitral annuloplasty using the Memo 3D ring were investigated. Mitral annular motion was assessed using QLAB®version8 allowing for a full evaluation of the mitral annulus dynamics. The mitral annular dimensions were measured throughout the cardiac cycle using 4D MV assessment2® while saddle shape was assessed through sequential measurements by RealView®. Saddle shape configuration of the mitral annulus and posterior and anterior leaflet motion could be observed during systole and diastole. The mitral annular area changed during the cardiac cycle by 5.7 ± 1.8%.The circumference length and diameter also changed throughout the cardiac cycle. The annular height was significantly higher in mid-systole than in mid-diastole (p 3D ring maintained a physiological saddle-shape configuration throughout the cardiac cycle. Real-time three-dimensional echocardiography analysis confirmed the motion and flexibility of the Memo 3D ring upon implantation.

  12. Biocompatibility and Systemic Safety of a Novel Implantable Annuloplasty Ring for the Treatment of Mitral Regurgitation in a Minipig Model.

    Science.gov (United States)

    Ramot, Yuval; Rousselle, Serge D; Yellin, Nadav; Willenz, Udi; Sabag, Itai; Avner, Avi; Nyska, Abraham

    2016-07-01

    Prosthetic annuloplasty rings are a common treatment modality for mitral regurgitation, and recently, percutaneous implantation techniques have gained popularity due to their favorable safety profile. Although in common use, biocompatibility of annuloplasty rings has been reported only sparsely in the literature, and none of these reports used the percutaneous technique of implantation. We report on the biocompatibility and the systemic safety of a novel transcatheter mitral valve annuloplasty ring (AMEND™) in 6 minipigs. This device is composed of a nitinol tube surrounded by a braided polyethylene terephthalate fabric tube. The device produced no adverse inflammatory response, showing gradual integration between the metal ring and the fabric by normal host fibrocellular response, leading to complete neoendocardium coverage. There was no evidence for adverse reactions, rejection, or intolerance in the valvular structure. In 2 animals, hemopericardium resulted from the implantation procedure, leading to right-sided cardiac insufficiency with pulmonary edema and liver congestion. The findings reported herein can serve as a case study for the expected healing pathology reactions after implantation of transcatheter mitral valve annuloplasty rings. © The Author(s) 2016.

  13. [Plastic repair of tricuspid valve: Carpentier's ring annuloplasty versus De VEGA technique].

    Science.gov (United States)

    Charfeddine, Salma; Hammami, Rania; Triki, Faten; Abid, Leila; Hentati, Mourad; Frikha, Imed; Kammoun, Samir

    2017-01-01

    Tricuspid valve disease has been neglected for a long time by cardiologists and surgeons, but for some years now leakage of tricuspid valve has been demonstrated as a prognostic factor in the evolution of patients with left heart valve disease undergoing surgery. Several techniques for plastic repair of tricuspid valve have been developed and the published studies differ on the results of these techniques; we conducted this study to assess the results of plastic repair of tricuspid valve in a population of patients with a high prevalence of rheumatic disease and to compare Carpentier's ring annuloplasty techniques with DEVEGA plasty. We conducted a retrospective study of patients undergoing plastic repair of tricuspid valve in the Department of Cardiology at the Medicine University of Sfax over a period of 25 years. We compared the results from the Group 1 (Carpentier's ring annuloplasty) with Group 2 (DeVEGA plasty). 91 patients were included in our study, 45 patients in the Group 1 and 46 patients in the Group 2. Most patients had mean or severe TI (83%) before surgery, ring dilation was observed in 90% of patients with no significant difference between the two groups. Immediate results were comparable between the two techniques but during monitoring recurrent, at least mean, insufficiency was significantly more frequent in the DeVEGA plasty Group. The predictive factors for significant recurring long term TI were DeVEGA technique (OR=3.26[1.12-9.28]) in multivariate study and preoperative pulmonary artery systolic pressure (OR=1.06 (1.01-1.12)). Plastic repair of tricuspid valve using Carpentier's ring seems to guarantee better results than DeVEGA plasty. On the other hand, preoperative high PASP is predictive of recurrent leakage of tricuspid valve even after plasty; hence the importance of surgery in the treatment of patients at an early stage of the disease.

  14. Prosthesis-patient mismatch due to small ring annuloplasty in patients with degenerative mitral insufficiency.

    Science.gov (United States)

    Kawamoto, Naonori; Fujita, Tomoyuki; Hata, Hiroki; Shimahara, Yusuke; Sato, Shunsuke; Kobayashi, Junjiro

    2016-08-01

    Avoidance of prosthesis-patient mismatch (PPM) is important when selecting a mitral valve prosthesis. This study investigated the effect of PPM after small ring mitral valve annuloplasty on postoperative hemodynamics and the clinical course. This study retrospectively reviewed 227 patients with symptomatic severe mitral insufficiency (MI) who underwent mitral valve repair for degenerative MI using an Edwards ring or band (size: 26-32mm) between 2003 and 2012. Echocardiography was performed postoperatively and at follow-up to evaluate cardiac function, including residual MI, mean transmitral pressure gradient, left atrial diameter (LAD), and tricuspid regurgitant pressure gradient (TRPG). There were no operative deaths. Actuarial freedom from major adverse cardiac events was 91% at 10 years. The postoperative MI grade was not significantly different between different sizes of prosthesis (26mm, 0.67±0.8; 28mm, 0.73±0.9; 30mm, 0.85±0.9; 32mm, 0.3±0.6). LAD and TRPG were significantly lower for each size of prosthesis at follow-up (all pbody surface area received a significantly smaller prosthesis (pprosthesis than in patients with a larger size of prosthesis. Thirty-three patients had a follow-up transmitral pressure gradient ≥5mmHg. The follow-up LAD was larger in patients with a transmitral pressure gradient prosthesis. However, use of a smaller prosthesis may result in a higher mean transmitral pressure gradient, and may inhibit reverse remodeling of the left atrium. Therefore, PPM should be avoided. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  15. Comparison of outcomes of tricuspid annuloplasty with 3D-rigid versus flexible prosthetic ring for functional tricuspid regurgitation secondary to rheumatic mitral valve disease.

    Science.gov (United States)

    Wang, Haiping; Liu, Xiancheng; Wang, Xin; Lv, Zhenqian; Liu, Xiaojun; Xu, Ping

    2016-11-01

    Annuloplasty bands and rings are widely used for repairing functional tricuspid regurgitation (FTR). However, the question regarding which is the ideal annuloplasty device remains unclear. The aim of this study was to compare the efficacy and mid-term durability of tricuspid ring annuloplasty for FTR secondary to rheumatic mitral valve disease using flexible Cosgrove-Edwards band and the rigid Edwards MC3 ring (Edwards Lifesciences, LLC, Irvine, CA, USA). We retrospectively collected the clinical data of those who underwent mitral valve replacement (MVR) in concomitant with tricuspid ring annuloplasty from 2009 to 2013. The flexible band was used in 46 patients (flexible group), and the 3D rigid ring was used in 60 patients (rigid group). Echocardiographic evaluation of tricuspid function was performed preoperatively and postoperatively. The grade of TR was significantly improved compared to preoperative values in two groups. There was no significant difference regarding postoperative TR grade between the two groups at 1 week and 2-3 months but there was statistical significant difference at postoperative 6-12 months, and 2-3 years. During the follow up period, 25 of 46 patients (54.3%) in flexible group and 22 of 60 patients (30.3%) in rigid group developed recurrent TR. Freedom from recurrent TR in flexible group is significant lower than rigid group in each postoperative follow up period. These findings suggest that 3D rigid ring annuloplasty might be more effective for tricuspid ring annuloplasty in FTR in mid-term postoperative periods when compared to flexible band.

  16. Early Clinical Outcomes of Tricuspid Valve Repair with a Tri-Ad Annuloplasty Ring in Comparison with the Outcomes Using an MC³ Ring

    Directory of Open Access Journals (Sweden)

    Woohyun Jung

    2018-04-01

    Full Text Available Background: We evaluated the early clinical outcomes of tricuspid valve annuloplasty (TAP with the Tri-Ad annuloplasty ring for functional tricuspid regurgitation (TR. Methods: From January 2015 to March 2017, 36 patients underwent TAP with a Tri-Ad ring for functional TR. To evaluate the early clinical outcomes of TAP with the Tri-Ad ring, we conducted a propensity score-matched analysis comparing the Tri-Ad and MC³ tri-cuspid annuloplasty rings (n=34 in each group. The follow-up duration was 11.0±7.07 months. Results: There was 1 case of operative mortality (2.8% and no cases of late mortality. Postoperative complications occurred in 15 patients (41%, including acute kidney injury in 6 patients (16%, bleeding requiring reoperation in 4 patients (11%, and low cardiac output syndrome in 4 patients (11%. There were no ring-related complications, such as atrioventricular block or ring dehiscence. The TR grade decreased significantly (from 2.03±1.06 to 1.18±0.92, p<0.01, as did the systolic pulmonary artery pressure (from 43.53±13.84 to 38.00±9.72 mm Hg, p=0.03. There were no cases of severe residual TR, but moderate TR was observed in 3 patients, all of whom had severe TR preoperatively. Severe preoperative TR was also associated with moderate in the univariate analysis (p<0.01. In the propensity score-matched analysis comparing the Tri-Ad and MC³ rings, there was no significant difference in early clinical outcomes. Conclusion: TAP with the Tri-Ad ring corrected functional TR effectively and provided good early clinical and echocardiographic results without ring-related complications. However, severe preoperative TR was associated with moderate or severe residual TR in the immediate postoperative period. A follow-up study is necessary to confirm the stability of this procedure.

  17. Mechanisms of valve competency after mitral valve annuloplasty for ischaemic mitral regurgitation using the Geoform ring: insights from three-dimensional echocardiography.

    Science.gov (United States)

    Armen, Todd A; Vandse, Rashmi; Crestanello, Juan A; Raman, Subha V; Bickle, Katherine M; Nathan, Nadia S

    2009-01-01

    Left ventricular remodelling leads to functional mitral regurgitation resulting from annular dilatation, leaflet tethering, tenting, and decreased leaflet coaptation. Mitral valve annuloplasty restores valve competency, improving the patient's functional status and ventricular function. This study was designed to evaluate the mechanisms underlying mitral valve competency after the implantation of a Geoform annuloplasty ring using three-dimensional (3D) echocardiography. Seven patients (mean age of 65 years) with ischaemic mitral regurgitation underwent mitral valve annuloplasty with the Geoform ring and coronary artery bypass surgery. Pre- and post-operative 3D echocardiograms were performed. Following mitral annuloplasty, mitral regurgitation decreased from 3.4+/-0.2 to 0.9+/-0.3 (P-value<0.0001), mitral valve tenting volume from 13+/-1.7 to 3.2+/-0.3 mL (P-value<0.001), annulus area from 12.6+/-1.0 to 3.3+/-0.2 cm2 (P-value<0.0001), valve circumference from 13+/-0.5 to 7.3+/-0.3 cm (P-value<0.0001), septolateral distance from 2.1+/-0.1 to 1.4+/-0.06 cm (P-value<0.01) and intercommissural distance from 3.4+/-0.1 to 2.7+/-0.03 cm (P-value<0.03). There was significant decrease in the septolateral distance at the level of A2-P2 with respect to other regions. These geometric changes were associated with the improvement in the NYHA class from 3.1+/-0.3 to 1.3+/-0.3 (P-value<0.002). The mitral valve annuloplasty with the Geoform ring restores leaflet coaptation and eliminates mitral regurgitation by effectively modifying the mitral annular geometry.

  18. Fracture of Colvin-Galloway-Future band in a patient with mitral valve annuloplasty.

    Science.gov (United States)

    Bauer, S; Rosendahl, U; Pietrowski, D; Ennker, J

    2006-08-01

    Annuloplasty with various annuloplasty ring systems is a fundamental part of mitral valve repair and has been frequently performed since its introduction by Carpentier in 1969. Due to the different advantages or disadvantages of each system, some controversies exist regarding the best type of ring annuloplasty support. Here we describe, for the first time, the case of a female patient in which a fracture of a semi-rigid open annuloplasty ring occurred, leading to annular deformation and mitral regurgitation.

  19. The role of annular dimension and annuloplasty in tricuspid aortic valve repair.

    Science.gov (United States)

    de Kerchove, Laurent; Mastrobuoni, Stefano; Boodhwani, Munir; Astarci, Parla; Rubay, Jean; Poncelet, Alain; Vanoverschelde, Jean-Louis; Noirhomme, Philippe; El Khoury, Gebrine

    2016-02-01

    Valve sparing reimplantation can improve the durability of bicuspid aortic valve repair compared with subcommissural annuloplasty, especially in patients with a large basal ring. This study analyses the effect of basal ring size and annuloplasty on valve repair in the setting of a tricuspid aortic valve. From 1995 to 2013, 382 patients underwent elective tricuspid aortic valve repair. We included only those undergoing subcommissural annuloplasty, valve sparing reimplantation or no annuloplasty and in whom intraoperative transoesophageal echocardiography images were available for retrospective pre- and post-repair basal ring measurements (n = 323, subcommissural annuloplasty: 146, valve sparing reimplantation: 154, no annuloplasty: 23). In a subgroup of patients with available echocardiographic images, basal ring was retrospectively measured at the latest follow-up or prior to reoperation. subcommissural annuloplasty and valve sparing reimplantation were compared after matching for degree of aortic regurgitation and root size. All three groups differed significantly for most of preoperative characteristics. Hospital mortality was 0.9%. The median follow-up was 4.7 years. At 8 years, overall survival was 80 ± 5%. Freedom from reoperation and freedom from aortic regurgitation >1+ were 92 ± 5% and 71 ± 8%, respectively. In multivariate analysis, predictors of aortic regurgitation >1+ were left ventricular end-diastolic diameter (P = 0.003), cusp repair (P = 0.006), body surface area (P = 0.01) and subcommissural annuloplasty (P = 0.05). In subcommissural annuloplasty, freedom from aortic regurgitation >1+ was lower for patients with basal ring ≥28 mm compared with patients with basal ring 1+ was independent of basal ring size (P = 0.38). In matched comparison between subcommissural annuloplasty and valve sparing reimplantation, freedom from aortic regurgitation >1+ was not significantly different (P = 0.06), but in patients with basal ring ≥28 mm, valve sparing

  20. Preoperative Three-Dimensional Valve Analysis Predicts Recurrent Ischemic Mitral Regurgitation After Mitral Annuloplasty

    NARCIS (Netherlands)

    Bouma, Wobbe; Lai, Eric K.; Levack, Melissa M.; Shang, Eric K.; Pouch, Alison M.; Eperjesi, Thomas J.; Plappert, Theodore J.; Yushkevich, Paul A.; Mariani, Massimo A.; Khabbaz, Kamal R.; Gleason, Thomas G.; Mahmood, Feroze; Acker, Michael A.; Woo, Y. Joseph; Cheung, Albert T.; Jackson, Benjamin M.; Gorman, Joseph H.; Gorman, Robert C.

    Background. Valve repair for ischemic mitral regurgitation (IMR) with undersized annuloplasty rings is characterized by high IMR recurrence rates. Patient-specific preoperative imaging-based risk stratification for recurrent IMR would optimize results. We sought to determine if prerepair

  1. Is tricuspid annuloplasty increasing surgical mortality and morbidity during mitral valve replacement? A single-centre experience.

    Science.gov (United States)

    Verdonk, Constance; Darmon, Arthur; Cimadevilla, Claire; Lepage, Laurent; Raffoul, Richard; Nataf, Patrick; Vahanian, Alec; Messika-Zeitoun, David

    2017-12-06

    Performance of tricuspid annuloplasty (TA) in patients undergoing mitral valve surgery is recommended based on the degree of tricuspid regurgitation and tricuspid annulus size, but is often underused. To evaluate the impact of combined TA on in-hospital outcome in patients undergoing mitral valve replacement (MVR). We selected all consecutive patients who underwent MVR for native valve disease. Clinical, echocardiographic and in-hospital complications were obtained from chart review. We identified 287 patients (mean age 62±17 years; 44% men). Combined TA was performed in 165 patients (57%), who had more rheumatic disease (71% vs. 24%; P<0.0001) and mitral stenosis (55% vs. 22%; P<0.0001), but less endocarditis (4% vs. 31%; P<0.0001), were more often in atrial fibrillation (54% vs. 22%; P<0.0001), were more severely symptomatic (80% vs. 57%; P<0.0001), presented with a higher systolic pulmonary artery pressure (SPAP) (53±16 vs. 45±15mmHg; P=0.0002) and were less likely to have required emergency surgery (17% vs. 38%; P<0.0001). Despite this higher risk profile, in-hospital mortality was slightly lower (5% vs. 13%; P=0.02) and complication rates were similar (redo surgery 22% vs. 16% [P=0.18] and tamponade 20% vs. 15% [P=0.15]). After adjustment for age, sex, functional class, SPAP, emergency surgery and concomitant coronary artery bypass graft or aortic valve replacement surgery, combined TA was not associated with an increased rate of in-hospital death (P=0.08) or major complications (P=0.89). In a consecutive series of patients who underwent MVR, TA did not seem to have a negative impact on immediate outcome. Hence, additional performance of TA at the time of MVR should not be declined on the basis of an increased surgical risk. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Storage ring proton EDM experiment

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    sensitivity of 10^-29 e-cm.  The strength of the method originates from the fact that there are high intensity polarized proton beams available and the fact that the so-called geometric phase systematic error background cancels with clock-wise and counter-clock-wise storage possible in electric rings. The ultimate sensitivity of the method is 10^-30 e-cm. At this level it will either detect a non-zero EDM or it will eliminate electro-weak baryogenesis.

  3. Transcatheter Mitral Valve-in-Ring Implantation

    LENUS (Irish Health Repository)

    Tanner, RE

    2018-05-01

    Failed surgical mitral valve repair using an annuloplasty ring has traditionally been treated with surgical valve replacement or repair1. For patients at high risk for repeat open heart surgery, placement of a trans-catheter aortic valve (i.e., TAVI valve) within the mitral ring (i.e., Mitral-Valve-in-Ring, MViR) has emerged as a novel alternative treatment strategy2-5 . We describe our experience of a failed mitral valve repair that was successfully treated with a TAVI valve delivered via the trans-septal approach, and summarise the data relating to this emerging treatment strategy.

  4. Initial clinical experience with a novel biodegradable ring in patients with functional tricuspid insufficiency: Kalangos Biodegradable Tricuspid Ring.

    Science.gov (United States)

    Burma, O; Ustunsoy, H; Davutoglu, V; Celkan, M A; Kazaz, H; Pektok, E

    2007-08-01

    Tricuspid annuloplasty procedures have been widely performed in clinics for many years. The Kalangos Biodegradable Tricuspid Ring (Kalangos Biodegradable Tricuspid Ring, Bioring SA, Lonay, Switzerland) is a novel prosthesis for the treatment of tricuspid insufficiency. The aim of this study was to evaluate the clinical and echocardiographic results of this novel prosthesis for functional tricuspid insufficiency. Between October 2005 and May 2006, 15 patients with the diagnosis of moderate or severe functional tricuspid insufficiency were treated by implantation of a Kalangos Biodegradable Tricuspid Ring. All patients were evaluated clinically and by echocardiography preoperatively, and control tests were performed at the end of the 1st and 6th month following surgery. Moderate and severe insufficiency was documented in 11 and 4 patients, respectively, in the preoperative tests. 1 and 6 months after surgery, 4 patients had trace and 1 patient had mild tricuspid insufficiency, while 10 patients had none. At the 1st and 6th month follow-up, systolic pulmonary arterial pressure, right atrial dimension and right ventricular diastolic diameter were found to be significantly lower than the preoperative values ( P tricuspid valve area had decreased significantly at the end of the 1st month; however, no significant difference was found between the 1st and 6th month tests ( P > 0.05). Three-quarters of the annuloplasty ring had degraded at 6 months. No complications related to the prosthesis or the procedure occurred within this period. Kalangos Biodegradable Ring is a promising prosthesis in patients with functional tricuspid insufficiency, with encouraging initial results.

  5. An intensive tree-ring experience

    NARCIS (Netherlands)

    Sánchez-Salguero, Raúl; Hevia, Andrea; Camarero, J.J.; Treydte, Kerstin; Frank, Dave; Crivellaro, Alan; Domínguez-Delmás, Marta; Hellman, Lena; Kaczka, Ryszard J.; Kaye, Margot; Akhmetzyanov, Linar; Ashiq, Muhammad Waseem; Bhuyan, Upasana; Bondarenko, Olesia; Camisón, Álvaro; Camps, Sien; García, Vicenta Constante; Vaz, Filipe Costa; Gavrila, Ionela G.; Gulbranson, Erik; Huhtamaa, Heli; Janecka, Karolina; Jeffers, Darren; Jochner, Matthias; Koutecký, Tomáš; Lamrani-Alaoui, Mostafa; Lebreton-Anberrée, Julie; Seijo, María Martín; Matulewski, Pawel; Metslaid, Sandra; Miron, Sergiu; Morrisey, Robert; Opdebeeck, Jorgen; Ovchinnikov, Svyatoslav; Peters, Richard; Petritan, Any M.; Popkova, Margarita; Rehorkova, Stepanka; Ariza, María O.R.; Sánchez-Miranda, Ángela; Linden, Van der Marjolein; Vannoppen, Astrid; Volařík, Daniel

    2017-01-01

    The European Dendroecologial Fieldweek (EDF) provides an intensive learning experience in tree-ring research that challenges any participant to explore new multidisciplinary dendro-sciences approaches within the context of field and laboratory settings. Here we present the 25th EDF, held in

  6. The Storage Ring Proton EDM Experiment

    Science.gov (United States)

    Semertzidis, Yannis; Storage Ring Proton EDM Collaboration

    2014-09-01

    The storage ring pEDM experiment utilizes an all-electric storage ring to store ~1011 longitudinally polarized protons simultaneously in clock-wise and counter-clock-wise directions for 103 seconds. The radial E-field acts on the proton EDM for the duration of the storage time to precess its spin in the vertical plane. The ring lattice is optimized to reduce intra-beam scattering, increase the statistical sensitivity and reduce the systematic errors of the method. The main systematic error is a net radial B-field integrated around the ring causing an EDM-like vertical spin precession. The counter-rotating beams sense this integrated field and are vertically shifted by an amount, which depends on the strength of the vertical focusing in the ring, thus creating a radial B-field. Modulating the vertical focusing at 10 kHz makes possible the detection of this radial B-field by a SQUID-magnetometer (SQUID-based BPM). For a total number of n SQUID-based BPMs distributed around the ring the effectiveness of the method is limited to the N = n /2 harmonic of the background radial B-field due to the Nyquist sampling theorem limit. This limitation establishes the requirement to reduce the maximum radial B-field to 0.1-1 nT everywhere around the ring by layers of mu-metal and aluminum vacuum tube. The metho's sensitivity is 10-29 e .cm , more than three orders of magnitude better than the present neutron EDM experimental limit, making it sensitive to SUSY-like new physics mass scale up to 300 TeV.

  7. Rotating ring-ring electrode theory and experiment

    NARCIS (Netherlands)

    Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kellyb, J.J.

    2000-01-01

    A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

  8. The Rotating Ring-Ring Electrode. Theory and Experiment

    NARCIS (Netherlands)

    Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kelly, J.J.

    2000-01-01

    A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

  9. Restrictive Mitral Annuloplasty Does Not Limit Exercise Capacity.

    Science.gov (United States)

    Deja, Marek A; Żak, Aleksandra; Malinowski, Marcin; Pysz, Piotr; Gaszewska-Żurek, Ewa; Turski, Maciej; Janusiewicz, Piotr; Wita, Krystian; Chudek, Jerzy

    2015-10-01

    Restrictive mitral annuloplasty is the preferred method of treating secondary mitral regurgitation. The use of small annuloplasty rings to reduce the high recurrence rates may result in mitral stenosis. Thirty-six patients who underwent restrictive mitral annuloplasty with Carpentier-Edwards classic 26 size ring underwent exercise echocardiography and ergospirometry. Resting catecholamines and N-terminal pro brain natriuretic peptide (NT-proBNP) levels were measured. At the time of study, the median time from operation was 16.6 months (interquartile range, 8.5 to 43.3 months). Left ventricular end-systolic volume index (LVESVI) was 67 mL/m(2) (interquartile range, 25 to 92 mL/m(2)), and ejection fraction (EF) was 38.8% (interquartile range, 28.3% to 59.0%). Mitral gradients were higher at the leaflet tips than at the annular level. Continuous wave (CW) Doppler gradients at rest were 3.4 mmHg (interquartile range, 2.4 to 4.9 mmHg) mean and 9.5 mmHg (interquartile range, 7.0 to 14.7 mmHg) maximal. On exertion, they increased to 6.8 mmHg (interquartile range, 5.4 to 8.8 mmHg) (p = 0.001) and 19.7 mmHg (interquartile range, 12.8 to 23.3 mmHg) (p = 0.001), respectively. Maximal VO2 was 18.2 mL/kg/min (interquartile range, 16.3 to 21.5 mL/kg/min), VE/VCO2 slope was 31.1 (interquartile range, 26 to 34). Epinephrine level was 0.024 ng/mL (interquartile range, 0.0098 to 0.043 ng/mL), norepinephrine was 0.61 ng/mL (interquartile range, 0.41 to 0.95 ng/mL), and NT-proBNP was 303 pg/mL (interquartile range, 155 to 553 pg/mL). Maximal VO2 negatively correlated with resting norepinephrine level (r = -0.50, p = 0.003). VE/VCO2 slope positively correlated with NT-proBNP (r = 0.36, p = 0.004) and epinephrine (r = 0.36, p = 0.04) levels and with LV volumes (r = 0.51, p = 0.006) and was negatively correlated with LVEF (r = -0.52, p = 0.004). Neither maximal VO2 nor VE/VCO2 slope correlated with the highest mean (r = 0.24, p = 0.2, and r = -0.20, p = 0.3, respectively) and maximal (r

  10. Preparation for electron ring - plasma ring merging experiments in RECE-MERGE

    International Nuclear Information System (INIS)

    Taggart, D.; Sekiguchi, A.; Fleischmann, H.H.

    1986-01-01

    The formation of a mixed-CT using relativistic electron rings and gun-produced plasma rings by MERGE-ing them axially is simulated. This process is similar to the axial stacking of relativistic electron rings in RECE-Christa. The results of their first plasm production experiment are reported here. After study of the gun-produced plasma's properties is completed, the gun will be mounted at the downstream end of the vacuum tank and the source of relativistic electron rings will be at the upstream end. The two rings, formed at opposite ends of the tank, will be translated axially and merged

  11. Neutrino Signals in Electron-Capture Storage-Ring Experiments

    Directory of Open Access Journals (Sweden)

    Avraham Gal

    2016-06-01

    Full Text Available Neutrino signals in electron-capture decays of hydrogen-like parent ions P in storage-ring experiments at GSI are reconsidered, with special emphasis placed on the storage-ring quasi-circular motion of the daughter ions D in two-body decays P → D + ν e . It is argued that, to the extent that daughter ions are detected, these detection rates might exhibit modulations with periods of order seconds, similar to those reported in the GSI storage-ring experiments for two-body decay rates. New dedicated experiments in storage rings, or using traps, could explore these modulations.

  12. Comparing CTH simulations and experiments on explosively loaded rings

    Science.gov (United States)

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

    2012-03-01

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

  13. Can tricuspid annuloplasty of the donor heart reduce valve insufficiency following cardiac transplantation with bicaval anastomosis?

    Science.gov (United States)

    Fiorelli, Alfredo I; Oliveira, José L; Santos, Ronaldo H B; Coelho, Guilherme B; Oliveira, Adriana S; Lourenço-Filho, Domingos D; Lapenna, Gisele; Dias, Ricardo R; Bacal, Fernando; Bocchi, Edimar A; Stolf, Noedir A G

    2010-06-01

    The aim of this study was to evaluate the degree of tricuspid valve insufficiency after orthotopic cardiac transplantation with bicaval anastomosis and prophylactic donor heart annuloplasty. At present, our cardiac transplantation experience includes 478 cases. After January 2002, we included 30 consecutive patients in this study who had undergone orthotopic cardiac transplantation and survived >6 months. The patients were divided into 2 groups: group I, 15 patients who underwent transplantation with prophylactic tricuspid annuloplasty on the donor heart with the De Vega technique; and group II, 15 patients who underwent transplantation without this procedure. Their preoperative clinical characteristics were the same. During the late postoperative follow-up, the degree of tricuspid insufficiency was evaluated by transthoracic Doppler echocardiography and assessed according to the Simpson scale: 0, absent; 1, mild; 2, moderate; and 3, severe. Hemodynamic parameters were evaluated invasively by means of a Swan-Ganz catheter during routine endomyocardial biopsies. The mean follow-up time was 26.9 +/- 5.4 months (range, 12-36 months). In group I, 1 patient (6.6%) died from infection in the 18th month after the operation; the death was not related to the annuloplasty. In group II, 1 death (6.6%) occurred after 10 months because of rejection (P > .05). After the 24-month follow-up, the mean degree of tricuspid insufficiency was 0.4 +/- 0.5 in group I and 1.7 +/- 0.9 in group II (P tricuspid annuloplasty on the donor heart was able to reduce significantly the degree of valvular insufficiency, even in cardiac transplantation with bicaval anastomosis; however, it did not modify significantly the hemodynamic performance of the allograft during the investigation period. It is very important to extend the observation period and casuistics to verify other benefits that this technique may offer.

  14. Restrictive annuloplasty to treat functional mitral regurgitation: optimize the restriction to improve the results?

    Science.gov (United States)

    Totaro, Pasquale; Adragna, Nicola; Argano, Vincenzo

    2008-03-01

    Today, the 'gold standard' treatment of functional mitral regurgitation (MR) is the subject of much discussion. Although restrictive annuloplasty is currently considered the most reproducible technique, the means by which the degree of annular restriction is optimized remains problematic. The study was designed in order to identify whether the degree of restriction of the mitral annulus could influence early and midterm results following the treatment of functional MR using restrictive annuloplasty. A total of 32 consecutive patients with functional MR grade > or = 3+ was enrolled, among whom the mean anterior-posterior (AP) mitral annulus diameter was 39 +/- 3 mm. Restrictive mitral annuloplasty (combined with coronary artery bypass grafting) was performed in all patients using a Carpentier-Edwards Classic or Physio ring (size 26 or 28). The degree of AP annular restriction was calculated for each patient, and correlated with early and mid-term residual MR and left ventricular (LV) reverse remodeling (in terms of LV end-diastolic diameter (LVEDD) and LV end-diastolic volume (LVEDV) reduction). All surviving patients were examined at a one-year follow up. The mean AP mitral annulus restriction achieved was 48 +/- 4%. Intraoperatively, transesophageal echocardiography showed no residual MR in any patient. Before discharge from hospital, transthoracic echocardiography confirmed an absence of residual MR and showed significant LV reverse remodeling (LVEDV from 121 +/- 25 ml to 97 +/- 26 ml; LVEDD from 55 +/- 6 mm to 47 +/- 8 mm). A significant correlation (r = 0.57, p 40% of preoperative) appears to have a favorable influence on early postoperative LV reverse remodeling, and also allows for complete resolution of functional MR. In addition, 'no tolerance' of early residual MR seems to have a favorable influence on mid-term results, leading to a reduction in the one-year recurrence of significant MR.

  15. Mycobacterium goodii endocarditis following mitral valve ring annuloplasty.

    Science.gov (United States)

    Parikh, Rohan B; Grant, Matthew

    2017-03-21

    Mycobacterium goodii is an infrequent human pathogen which has been implicated in prosthesis related infections and penetrating injuries. It is often initially misidentified as a gram-positive rod by clinical microbiologic laboratories and should be considered in the differential diagnosis. We describe here the second reported case of M. goodii endocarditis. Species level identification was performed by 16S rDNA (ribosomal deoxyribonucleic acid) gene sequencing. The patient was successfully treated with mitral valve replacement and a prolonged combination of ciprofloxacin and trimethoprim/sulfamethoxazole. Confirmation of the diagnosis utilizing molecular techniques and drug susceptibility testing allowed for successful treatment of this prosthetic infection.

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

    Science.gov (United States)

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

    2017-11-01

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

  17. Does concomitant tricuspid annuloplasty increase perioperative mortality and morbidity when correcting left-sided valve disease?

    Science.gov (United States)

    Zhu, Tie-Yuan; Wang, Jian-Gang; Meng, Xu

    2015-01-01

    A best evidence topic in adult valvular surgery was written according to a structured protocol. The question addressed was 'Does concomitant tricuspid annuloplasty increase the perioperative mortality and morbidity when correcting left-sided valve disease?' A total of 561 papers were found using the reported search, of which 12 presented the best evidence to answer the clinical question. The authors, country, journal, date of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Among these 12 papers, there were nine retrospective studies, two cohort studies and one randomized controlled trial (RCT). Overall, additional tricuspid valve (TV) repair takes more time during operations, particularly with a ring annuloplasty method. The mean aortic cross-clamping times were 57-83 min without associated tricuspid repair and 62-100 min with, and cardiopulmonary bypass times without and with repair were 82-124 and 90-174 min, respectively. A study of 624 patients who had undergone isolated mitral valve (MV) surgery and MV surgery plus TV repair showed more female and atrial fibrillation patients in the tricuspid valve plasty (TVP) group, but no increase in the 30-day mortality was found. One RCT, presenting similar patient baseline characteristics, also found no difference in the hospital mortality rates between the TVP group and the non-TVP group. Another 10 studies also demonstrated no statistically significant differences in perioperative mortality. In a cohort study of 311 patients undergoing MV repair with or without tricuspid annuloplasty, postoperative complications, such as bleeding, stroke, pacemaker, haemofiltration and myocardial infarction, all showed no statistically significant differences in the two groups. One study retrospectively analysed a large number of patients undergoing either isolated left-sided valve surgery or a concomitant TV repair, and there were no statistically significant differences

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

    International Nuclear Information System (INIS)

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

    1987-06-01

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

  19. Numerical modeling of the plasma ring acceleration experiment

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  20. SPARC experiments at the high-energy storage ring

    International Nuclear Information System (INIS)

    Stöhlker, Thomas; Litvinov, Yuri A; Bagnoud, Vincent; Dimopoulou, Christina; Dolinskii, Alexei; Geppert, Christopher; Hagmann, Siegbert; Katayama, Takeshi; Kühl, Thomas; Nörtershäuser, Wilfried; Steck, Markus; Bechstedt, Ulf; Maier, Rudolf; Prasuhn, Dieter; Stockhorst, Hans; Schuch, Reinhold

    2013-01-01

    The physics program of the SPARC collaboration at the Facility for Antiproton and Ion Research (FAIR) focuses on the study of collision phenomena in strong and even extreme electromagnetic fields and on the fundamental interactions between electrons and heavy nuclei up to bare uranium. Here we give a short overview on the challenging physics opportunities of the high-energy storage ring at FAIR for future experiments with heavy-ion beams at relativistic energies with particular emphasis on the basic beam properties to be expected. (paper)

  1. Vanishing De Vega annuloplasty for functional tricuspid regurgitation.

    Science.gov (United States)

    Duran, C M; Kumar, N; Prabhakar, G; Ge, Z; Bianchi, S; Gometza, B

    1993-10-01

    Annuloplasty is performed for significant functional tricuspid regurgitation even if it is presumed that in some cases the regurgitation will regress spontaneously after correction of the left-sided lesion. In an attempt to avoid the drawbacks of a permanent annuloplasty, we used a reabsorbable De Vega annuloplasty in a selected group of patients. Of 73 patients with functional tricuspid regurgitation operated on between May 1989 and May 1991, 25 with pulmonary arteriolar resistance below 400 dyne.sec.cm-5 underwent a De Vega annuloplasty with 2-0 polydioxanone suture. The diagnosis of significant functional tricuspid regurgitation (mean 2.74 +/- 1.05) was established by transthoracic color Doppler echocardiography in all patients. The degree of functional tricuspid regurgitation and pulmonary arteriolar resistance were measured with the patients anesthetized. In 16 patients the regurgitation remained severe (3+ to 4+) and in 9 it was moderate (2+). Twenty-three patients had mitral (12 repairs, 11 replacements) and 9 had aortic (4 repairs, 5 replacements) valve operations. The immediate postbypass residual functional tricuspid regurgitation was 0 to 1+ in 23 and 0 in 2. There was 1 (4%) operative death. The maximum follow-up period was 24 months (mean 13.9 months). There were 2 (8.3%) late deaths. Six patients underwent reoperation because of mitral dysfunction. Four of them who were reoperated on between 2 and 5 weeks after the initial procedure showed no recurrence of functional tricuspid regurgitation. The other 2, reoperated on at 5 and 10 months after the first operation, had recurrence of functional tricuspid regurgitation. Visual inspection of these two tricuspid valves showed a dilated anulus with otherwise normal valves. All surviving patients are in New York Heart Association functional class I or II without significant functional tricuspid regurgitation (mean 0.78 +/- 0.56). We concluded that functional tricuspid regurgitation in patients with low

  2. Local beam position feedback experiments on the ESRF storage ring

    International Nuclear Information System (INIS)

    Chung, Y.; Kahana, E.; Kirchman, J.

    1995-01-01

    This paper describes the results of local beam position feedback experiments conducted on the ESRF storage ring using digital signal processing (DSP) under the trilateral agreement of collaboration among ESRF, APS, and SPring-8. Two rf beam position monitors (BPMS) in the, upstream and downstream of the insertion device (ID) and two x-ray BPMs in the sixth cell were used to monitor the electron beam and the x-ray beam emitted from the ID, respectively. The local bump coefficients were obtained using the technique of singular value decomposition (SVD) on the global response matrix for the bump magnets and all the available BPMs outside the local bump. The local response matrix was then obtained between the two three-magnet bumps and the position monitors. The data sampling frequency was 4 kHz and a proportional, integral, and derivative (PID) controller was used. The result indicates the closed-loop feedback bandwidth close to 100 Hz and clear attenuation (∼ -40 dB) of the 7-Hz beam motion due to girder vibration resonance. Comparison of the results using the rf BPMs and x-ray BPMs will be also discussed

  3. ''C-ring'' stress corrosion cracking scoping experiment for Zircaloy spent fuel cladding

    International Nuclear Information System (INIS)

    Smith, H.D.

    1986-03-01

    This document describes the purpose and execution of the stress corrosion cracking scoping experiment using ''C-ring'' cladding specimens. The design and operation of the ''C-ring'' stressing apparatus is described and discussed. The experimental procedures and post-experiment sample evaluation are described

  4. Experience with a high-brightness storage ring: the NSLS 750 MeV vuv ring

    International Nuclear Information System (INIS)

    Galayda, J.

    1984-01-01

    The NSLS vuv ring is the first implementation of the proposals of R. Chasman and G.K. Green for a synchrotron radiation source with enhanced brightness: its lattice is a series of achromatic bends with two zero-gradient dipoles each, giving small damped emittance; and these bends are connected by straight sections with zero dispersion to accommodate wigglers and undulators without degrading the radiation damping properties of the ring. The virtues of the Chasman-Green lattice, its small betatron and synchrotron emittances, may be understood with some generality; e.g. the electron γm 0 c 2 energy and the number of achromatic bends M sets a lower limit on the betatron emittance of e/sub x/ > 7.7 x 10 -13 γ 2 /M meter-radians. There is strong interest in extrapolation of this type of lattice to 6 GeV and to 32 achromatic bends. The subject of this report is the progress toward achieving performance in the vuv ring limited by the radiation damping parameters optimized in its design. 14 refs., 4 figs., 1 tab

  5. Impact of the Dapivirine Vaginal Ring on Sexual Experiences and Intimate Partnerships of Women in an HIV Prevention Clinical Trial: Managing Ring Detection and Hot Sex.

    Science.gov (United States)

    Laborde, Nicole D; Pleasants, Elizabeth; Reddy, Krishnaveni; Atujuna, Millicent; Nakyanzi, Teopista; Chitukuta, Miria; Naidoo, Sarita; Palanee-Phillips, Thesla; Baeten, Jared M; Montgomery, Elizabeth T

    2018-02-01

    Vaginally-inserted HIV prevention methods have been reported to impact the sexual experience for women and their partners, and hence impacts acceptability of and adherence to the method. We analyzed in-depth interviews and focus group discussions about participants' sexual experiences while wearing the ring, collected during the MTN-020/ASPIRE phase 3 safety and effectiveness trial of a dapivirine vaginal ring for HIV prevention in Malawi, South Africa, Uganda, and Zimbabwe. Most women reported that partners did not feel the ring during sex, however, women felt they had to manage their partners' interaction with or reaction to the ring. In maintaining positive relationships, women were concerned about partners' discovering ring use and about ensuring that partners had a good sexual experience with them. Finally women were concerned about how they themselves experienced sex with the ring. Some found that the ring made the vaginal environment more desirable for their partners and themselves.

  6. Impact of the Dapivirine Vaginal Ring on Sexual Experiences and Intimate Partnerships of Women in an HIV Prevention Clinical Trial: Managing Ring Detection and Hot Sex

    Science.gov (United States)

    Pleasants, Elizabeth; Reddy, Krishnaveni; Atujuna, Millicent; Nakyanzi, Teopista; Chitukuta, Miria; Naidoo, Sarita; Palanee-Phillips, Thesla; Baeten, Jared M.; Montgomery, Elizabeth T.

    2018-01-01

    Vaginally-inserted HIV prevention methods have been reported to impact the sexual experience for women and their partners, and hence impacts acceptability of and adherence to the method. We analyzed in-depth interviews and focus group discussions about participants’ sexual experiences while wearing the ring, collected during the MTN-020/ASPIRE phase 3 safety and effectiveness trial of a dapivirine vaginal ring for HIV prevention in Malawi, South Africa, Uganda, and Zimbabwe. Most women reported that partners did not feel the ring during sex, however, women felt they had to manage their partners’ interaction with or reaction to the ring. In maintaining positive relationships, women were concerned about partners’ discovering ring use and about ensuring that partners had a good sexual experience with them. Finally women were concerned about how they themselves experienced sex with the ring. Some found that the ring made the vaginal environment more desirable for their partners and themselves. PMID:29151197

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  9. Modeling of critical experiments employing Raschig rings in uranyl nitrate solution

    International Nuclear Information System (INIS)

    Tanner, J.E.

    1989-01-01

    Four critical experiments employing borated glass rings in concentrated uranyl nitrate solution yielded k eff higher by 0. 04 when modeled with a flux-weighted, homogenized cross section set than when modeled with discrete rings. k eff varied by 0.014 for a 10% boron uncertainty and by up to 0.04 for a 10% packing fraction uncertainty

  10. Experiences with permanent magnets at the Fermilab recycler ring

    International Nuclear Information System (INIS)

    Volk, James T

    2011-01-01

    In order to achieve higher luminosities in Run II a separate antiproton storage ring was built in the Main Injector tunnel. To reduce both construction and operations costs permanent magnets were used. This paper discusses the design criterion and specifications, including temperature dependence, longitudinal uniformity, and adjusting of the higher harmonics of the magnets. The design tolerances for a storage ring are more stringent than for a single pass beam line. The difference between the measured and ideal central field for each magnet was held to better than 0.1%. The temperature stability for all magnets was set to better than 0.01% per degree Celsius. Higher order harmonics relative to the central field were set to less than 0.01%. This was done for all 484 permanent magnet that were built.

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

    Science.gov (United States)

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

    2017-10-01

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

  12. Experiments at the Frankfurt low energy storage ring (FLSR)

    International Nuclear Information System (INIS)

    King, F; Stiebing, K E; Dörner, R; Müller, J; Schmidt, L Ph; Schmidt Böking, H

    2015-01-01

    FLSR has been designed for experiments on the dynamics of atomic and molecular collisions. After successful commissioning, an experiment on the dissociative recombination of 4 HeH + has been started. (paper)

  13. Performance of high-resolution position-sensitive detectors developed for storage-ring decay experiments

    International Nuclear Information System (INIS)

    Yamaguchi, T.; Suzaki, F.; Izumikawa, T.; Miyazawa, S.; Morimoto, K.; Suzuki, T.; Tokanai, F.; Furuki, H.; Ichihashi, N.; Ichikawa, C.; Kitagawa, A.; Kuboki, T.; Momota, S.; Nagae, D.; Nagashima, M.; Nakamura, Y.; Nishikiori, R.; Niwa, T.; Ohtsubo, T.; Ozawa, A.

    2013-01-01

    Highlights: • Position-sensitive detectors were developed for storage-ring decay spectroscopy. • Fiber scintillation and silicon strip detectors were tested with heavy ion beams. • A new fiber scintillation detector showed an excellent position resolution. • Position and energy detection by silicon strip detectors enable full identification. -- Abstract: As next generation spectroscopic tools, heavy-ion cooler storage rings will be a unique application of highly charged RI beam experiments. Decay spectroscopy of highly charged rare isotopes provides us important information relevant to the stellar conditions, such as for the s- and r-process nucleosynthesis. In-ring decay products of highly charged RI will be momentum-analyzed and reach a position-sensitive detector set-up located outside of the storage orbit. To realize such in-ring decay experiments, we have developed and tested two types of high-resolution position-sensitive detectors: silicon strips and scintillating fibers. The beam test experiments resulted in excellent position resolutions for both detectors, which will be available for future storage-ring experiments

  14. Preliminary results of the Adone storage ring FEL experiment, LELA

    International Nuclear Information System (INIS)

    Barbini, R.; Vignola, G.; Trillo, S.

    1983-01-01

    A short description of the LELA (Free Electron Laser on Adone) experiment is given. Results on the spontaneous radiation angle and energy spectra and preliminary results on optical gain measurements are also discussed

  15. Cosmic AntiParticle Ring Imaging Cerenkov Experiment

    CERN Multimedia

    2002-01-01

    %RE2A \\\\ \\\\ %title \\\\ \\\\The CAPRICE experiment studies antimatter and light nuclei in the cosmic rays as well as muons in the atmosphere. The experiment is performed with the spectrometer shown in the figure which is lifted by a balloon to an altitude of 35-40 km. At this altitude less than half a percent of the atmosphere is above the 2 ton spectrometer which makes it possible to study the cosmic ray flux without too much background from atmospherically produced particles. The spectrometer includes time-of-flight scintillators, a gaseous RICH counter, a drift chamber tracker and a silicon electromagnetic calorimeter. The important feature of the spectrometer is to discriminate between different particles.\\\\ \\\\ The experiment aims at measuring the flux of the antiparticles (antiprotons and positrons) above about 5 GeV and relate the fluxes to models including exotic production of antiparticles like dark matter supersymmetric particles. The flux of muons is measured during descent of the balloon through the at...

  16. A New Version of an Old Demonstration Experiment Using the Elihu Thomson Jumping Ring Apparatus

    Science.gov (United States)

    Foster, Theodore; Cary, Arthur; Mottmann, John; van Wyngaarden, Willem

    2016-01-01

    The goal of this paper is to make more widely known an eye-catching demonstration experiment in which a hanging conducting can is made to spin when placed near the iron core of an Elihu Thomson "jumping ring" apparatus. An explanation is given based on Faraday's law of induced voltages and the magnetic forces due to the core's fields…

  17. Ring recognition and electron identification in the RICH detector of the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Lebedev, S; Hoehne, C; Ososkov, G

    2010-01-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility at Darmstadt will measure dileptons emitted from the hot and dense phase in heavy-ion collisions. In case of an electron measurement, a high purity of identified electrons is required in order to suppress the background. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detectors (TRD). In this contribution we will present algorithms and software which have been developed for electron identification in CBM. Efficient and fast ring recognition in the RICH detector is based on the Hough Transform method which has been accelerated considerably compared to a standard implementation. Ring quality selection is done using an Artificial Neural Network which also has been used for electron identification. Due to optical distortions ellipse fitting and radius corre ction routines are used for improved ring radius resolution. These methods allow for a high purity and efficiency of reconstructed electron rings. For momenta above 2 GeV/c the ring reconstruction efficiency for electrons embedded in central Au+Au collisions at 25 AGeV beam energy is 95% resulting in an electron identification efficiency of 90% at a pion suppression factor of 500. Including information from the TRD a pion suppression of 10 4 is reached at 80% efficiency. The developed algorithm is very robust to a high ring density environment. Current work focusses on detector layout studies in order to optimize the detector setup while keeping a high performance. All developed algorithms were tested on large statistics of simulated events and are included into the CBM software framework for common use.

  18. A storage ring experiment to detect a proton electric dipole moment

    Energy Technology Data Exchange (ETDEWEB)

    Anastassopoulos, V. [Department of Physics, University of Patras, 26500 Rio-Patras, Greece; Andrianov, S. [Faculty of Applied Mathematics and Control Processes, Saint-Petersburg State University, Saint-Petersburg, Russia; Baartman, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T2A3, Canada; Baessler, S. [Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA; Bai, M. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Benante, J. [Brookhaven National Laboratory, Upton, New York 11973, USA; Berz, M. [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA; Blaskiewicz, M. [Brookhaven National Laboratory, Upton, New York 11973, USA; Bowcock, T. [Department of Physics, University of Liverpool, Liverpool, United Kingdom; Brown, K. [Brookhaven National Laboratory, Upton, New York 11973, USA; Casey, B. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Conte, M. [Physics Department and INFN Section of Genoa, 16146 Genoa, Italy; Crnkovic, J. D. [Brookhaven National Laboratory, Upton, New York 11973, USA; D’Imperio, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Fanourakis, G. [Institute of Nuclear and Particle Physics NCSR Demokritos, GR-15310 Aghia Paraskevi Athens, Greece; Fedotov, A. [Brookhaven National Laboratory, Upton, New York 11973, USA; Fierlinger, P. [Technical University München, Physikdepartment and Excellence-Cluster “Universe,” Garching, Germany; Fischer, W. [Brookhaven National Laboratory, Upton, New York 11973, USA; Gaisser, M. O. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Giomataris, Y. [CEA/Saclay, DAPNIA, 91191 Gif-sur-Yvette Cedex, France; Grosse-Perdekamp, M. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA; Guidoboni, G. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Hacıömeroğlu, S. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Hoffstaetter, G. [Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, New York 14853, USA; Huang, H. [Brookhaven National Laboratory, Upton, New York 11973, USA; Incagli, M. [Physics Department, University and INFN Pisa, Pisa, Italy; Ivanov, A. [Faculty of Applied Mathematics and Control Processes, Saint-Petersburg State University, Saint-Petersburg, Russia; Kawall, D. [Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA; Kim, Y. I. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; King, B. [Department of Physics, University of Liverpool, Liverpool, United Kingdom; Koop, I. A. [Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia; Lazarus, D. M. [Brookhaven National Laboratory, Upton, New York 11973, USA; Lebedev, V. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Lee, M. J. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Lee, S. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Lee, Y. H. [Korea Research Institute of Standards and Science, Daejeon 34141, South Korea; Lehrach, A. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; RWTH Aachen University and JARA-Fame, III. Physikalisches Institut B, Physikzentrum, 52056 Aachen, Germany; Lenisa, P. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Levi Sandri, P. [Laboratori Nazionali di Frascati, INFN, I-00044 Frascati, Rome, Italy; Luccio, A. U. [Brookhaven National Laboratory, Upton, New York 11973, USA; Lyapin, A. [Royal Holloway, University of London, Egham, Surrey, United Kingdom; MacKay, W. [Brookhaven National Laboratory, Upton, New York 11973, USA; Maier, R. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Makino, K. [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA; Malitsky, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Marciano, W. J. [Brookhaven National Laboratory, Upton, New York 11973, USA; Meng, W. [Brookhaven National Laboratory, Upton, New York 11973, USA; Meot, F. [Brookhaven National Laboratory, Upton, New York 11973, USA; Metodiev, E. M. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Harvard College, Harvard University, Cambridge, Massachusetts 02138, USA; Miceli, L. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Moricciani, D. [Dipartimento di Fisica dell’Univ. di Roma “Tor Vergata” and INFN Sezione di Roma Tor Vergata, Rome, Italy; Morse, W. M. [Brookhaven National Laboratory, Upton, New York 11973, USA; Nagaitsev, S. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Nayak, S. K. [Brookhaven National Laboratory, Upton, New York 11973, USA; Orlov, Y. F. [Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, New York 14853, USA; Ozben, C. S. [Istanbul Technical University, Istanbul 34469, Turkey; Park, S. T. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Pesce, A. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Petrakou, E. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Pile, P. [Brookhaven National Laboratory, Upton, New York 11973, USA; Podobedov, B. [Brookhaven National Laboratory, Upton, New York 11973, USA; Polychronakos, V. [Brookhaven National Laboratory, Upton, New York 11973, USA; Pretz, J. [RWTH Aachen University and JARA-Fame, III. Physikalisches Institut B, Physikzentrum, 52056 Aachen, Germany; Ptitsyn, V. [Brookhaven National Laboratory, Upton, New York 11973, USA; Ramberg, E. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Raparia, D. [Brookhaven National Laboratory, Upton, New York 11973, USA; Rathmann, F. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Rescia, S. [Brookhaven National Laboratory, Upton, New York 11973, USA; Roser, T. [Brookhaven National Laboratory, Upton, New York 11973, USA; Kamal Sayed, H. [Brookhaven National Laboratory, Upton, New York 11973, USA; Semertzidis, Y. K. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea; Senichev, Y. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Sidorin, A. [Joint Institute for Nuclear Research, Dubna, Moscow region, Russia; Silenko, A. [Joint Institute for Nuclear Research, Dubna, Moscow region, Russia; Research Institute for Nuclear Problems of Belarusian State University, Minsk, Belarus; Simos, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Stahl, A. [RWTH Aachen University and JARA-Fame, III. Physikalisches Institut B, Physikzentrum, 52056 Aachen, Germany; Stephenson, E. J. [Indiana University Center for Spacetime Symmetries, Bloomington, Indiana 47405, USA; Ströher, H. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Syphers, M. J. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA; Talman, J. [Brookhaven National Laboratory, Upton, New York 11973, USA; Talman, R. M. [Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, New York 14853, USA; Tishchenko, V. [Brookhaven National Laboratory, Upton, New York 11973, USA; Touramanis, C. [Department of Physics, University of Liverpool, Liverpool, United Kingdom; Tsoupas, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Venanzoni, G. [Laboratori Nazionali di Frascati, INFN, I-00044 Frascati, Rome, Italy; Vetter, K. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA; Vlassis, S. [Department of Physics, University of Patras, 26500 Rio-Patras, Greece; Won, E. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Physics Department, Korea University, Seoul 02841, South Korea; Zavattini, G. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Zelenski, A. [Brookhaven National Laboratory, Upton, New York 11973, USA; Zioutas, K. [Department of Physics, University of Patras, 26500 Rio-Patras, Greece

    2016-11-01

    A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of $10^{-29}e\\cdot$cm by using polarized "magic" momentum $0.7$~GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the Standard Model at the scale of 3000~TeV.

  19. A storage ring experiment to detect a proton electric dipole moment.

    Science.gov (United States)

    Anastassopoulos, V; Andrianov, S; Baartman, R; Baessler, S; Bai, M; Benante, J; Berz, M; Blaskiewicz, M; Bowcock, T; Brown, K; Casey, B; Conte, M; Crnkovic, J D; D'Imperio, N; Fanourakis, G; Fedotov, A; Fierlinger, P; Fischer, W; Gaisser, M O; Giomataris, Y; Grosse-Perdekamp, M; Guidoboni, G; Hacıömeroğlu, S; Hoffstaetter, G; Huang, H; Incagli, M; Ivanov, A; Kawall, D; Kim, Y I; King, B; Koop, I A; Lazarus, D M; Lebedev, V; Lee, M J; Lee, S; Lee, Y H; Lehrach, A; Lenisa, P; Levi Sandri, P; Luccio, A U; Lyapin, A; MacKay, W; Maier, R; Makino, K; Malitsky, N; Marciano, W J; Meng, W; Meot, F; Metodiev, E M; Miceli, L; Moricciani, D; Morse, W M; Nagaitsev, S; Nayak, S K; Orlov, Y F; Ozben, C S; Park, S T; Pesce, A; Petrakou, E; Pile, P; Podobedov, B; Polychronakos, V; Pretz, J; Ptitsyn, V; Ramberg, E; Raparia, D; Rathmann, F; Rescia, S; Roser, T; Kamal Sayed, H; Semertzidis, Y K; Senichev, Y; Sidorin, A; Silenko, A; Simos, N; Stahl, A; Stephenson, E J; Ströher, H; Syphers, M J; Talman, J; Talman, R M; Tishchenko, V; Touramanis, C; Tsoupas, N; Venanzoni, G; Vetter, K; Vlassis, S; Won, E; Zavattini, G; Zelenski, A; Zioutas, K

    2016-11-01

    A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of 10 -29 e ⋅ cm by using polarized "magic" momentum 0.7 GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the standard model at the scale of 3000 TeV.

  20. Mitral valve annuloplasty with a bovine pericardial strip - 18-year results Anuloplastia mitral com tira de pericárdio bovino resultados de 18 anos

    Directory of Open Access Journals (Sweden)

    Pablo Maria Alberto Pomerantzeff

    2005-08-01

    Full Text Available PURPOSE: Prosthetic annuloplasty rings are currently used in mitral reconstruction. Posterior annuloplasty with a bovine pericardial strip is a technique largely used in the Heart Institute of University of São Paulo Medical School. The purpose of the study was to analyze the late results of mitral valve repair with posterior annuloplasty using a bovine pericardial strip. METHODS: Between January 1984 and December 2002, 273 patients underwent mitral valve repair with posterior pericardial annuloplasty in the Heart Institute of University of São Paulo Medical School. One hundred and forty four (52.7% were women and ages ranged between 1 and 76 years (38.3 ± 21.1. Rheumatic fever was present in 52.0% of the patients. Associated techniques were employed in 26.0% of the patients, and the most frequent was chordal shortening (9.2%. RESULTS: Hospital mortality was 3.3% (9 patients, with the major cause being low cardiac output (6 patients. Actuarial survival was 55.1% ± 16.8% in 18 years. During the 18-year follow-up: patients were free from the following: reoperation (59.1% ±± 13.9%, (percent +/- Standard Error, thromboembolism (97.4% ± 2.3%, hemolysis (99.2% ± 0.2%, and endocarditis (99.6% ± 1.0%. In the late follow-up period, 83.9% were classified as New York Heart Association functional class I. CONCLUSIONS: Late results with mitral valve repair with posterior annuloplasty using a bovine pericardial strip were satisfactory. The technique is feasible, reproducible, and cost effective.OBJETIVO: Anéis protéticos para anuloplastia são usados nas plásticas da valva mitral de forma rotineira. A anuloplastia posterior com tira de pericárdio bovino é uma técnica largamente utilizada no Instituto do Coração - HC - FMUSP. O objetivo deste estudo foi analisar os resultados tardios da plástica da valva mitral com a utilização desta técnica na nossa instituição. MÉTODOS: Entre janeiro de 1984 e dezembro de 2002, 273 pacientes foram

  1. Detector system for e-d scattering experiments on the VEPP-3 storage ring

    International Nuclear Information System (INIS)

    Isaeva, L.G.; Lazarenko, B.A.; Nikolenko, D.M.; Popov, S.G.; Rachek, I.A.; Ukraintsev, Yu.G.; Tsentalovich, E.P.; Wojtsekhowski, B.B.; Nelubin, V.V.

    1993-01-01

    Experiments on electron scattering from polarized deuterons were carried out on the VEPP-3 storage ring at the Novosibirsk Institute for Nuclear Physics. The e-D coincidences were detected for elastic scattering experiments, and the p-n coincidences for photo disintegration studies. The tensor analyzing power of the elastic scattering was measured in the range of momentum transfer up to 3 f -1 , and of photo disintegration in the range of photon energy up to 500 MeV. The detector system created for these experiments and the data analysis procedures are described in this paper. (orig.)

  2. ANL stochastic-cooling experiments using the FNAL 200-MeV cooling ring

    International Nuclear Information System (INIS)

    Hogrefe, R.L.; Kellogg, K.D.; Konecny, R.S.; Kramer, S.L.; Simpson, J.D.; Suddeth, D.E.; Hardek, T.W.

    1981-01-01

    Studies of stochastic momentum cooling are being conducted on the FNAL 200-MeV Storage Ring. The specific goal of the activity is to establish confidence in the theory and simulation methods used to describe the cooling process, and to develop techniques and devices suitable for use in the antiproton-accumulation scheme now planned for construction at FNAL. A summary of the activity, including hardware design, results of experiments, comparison with theory, and implications for the antiproton accumulator are presented

  3. QED in highly-charged high Z ions - experiments at the storage ring ESR

    International Nuclear Information System (INIS)

    Mokler, P.H.

    1996-01-01

    A survey on the fundamental structure aspects of very heavy few -electron ions, in particular H-like systems, is presented. Special emphasis is given to contribution from quantum-electro-dynamics at strong central potentials. The technical possibilities to produce highly-charged heavy ions are reviewed and the ground-state Lamb-shift experiments performed at the heavy ion storage ring ESR are summarized. A short outlook on further developments in this field is added. (author). 23 refs, 9 figs

  4. The value of preoperative 3-dimensional over 2-dimensional valve analysis in predicting recurrent ischemic mitral regurgitation after mitral annuloplasty

    NARCIS (Netherlands)

    Wijdh-den Hamer, Inez J.; Bouma, Wobbe; Lai, Eric K.; Levack, Melissa M.; Shang, Eric K.; Pouch, Alison M.; Eperjesi, Thomas J.; Plappert, Theodore J.; Yushkevich, Paul A.; Hung, Judy; Mariani, Massimo A.; Khabbaz, Kamal R.; Gleason, Thomas G.; Mahmood, Feroze; Acker, Michael A.; Woo, Y. Joseph; Cheung, Albert T.; Gillespie, Matthew J.; Jackson, Benjamin M.; Gorman, Joseph H.; Gorman, Robert C.

    Objectives: Repair for ischemic mitral regurgitation with undersized annuloplasty is characterized by high recurrence rates. We sought to determine the value of pre-repair 3-dimensional echocardiography over 2-dimensional echocardiography in predicting recurrence at 6 months. Methods: Intraoperative

  5. Ring-fault activity at subsiding calderas studied from analogue experiments and numerical modeling

    Science.gov (United States)

    Liu, Y. K.; Ruch, J.; Vasyura-Bathke, H.; Jonsson, S.

    2017-12-01

    Several subsiding calderas, such as the ones in the Galápagos archipelago and the Axial seamount in the Pacific Ocean have shown a complex but similar ground deformation pattern, composed of a broad deflation signal affecting the entire volcanic edifice and of a localized subsidence signal focused within the caldera. However, it is still debated how deep processes at subsiding calderas, including magmatic pressure changes, source locations and ring-faulting, relate to this observed surface deformation pattern. We combine analogue sandbox experiments with numerical modeling to study processes involved from initial subsidence to later collapse of calderas. The sandbox apparatus is composed of a motor driven subsiding half-piston connected to the bottom of a glass box. During the experiments the observation is done by five digital cameras photographing from various perspectives. We use Photoscan, a photogrammetry software and PIVLab, a time-resolved digital image correlation tool, to retrieve time-series of digital elevation models and velocity fields from acquired photographs. This setup allows tracking the processes acting both at depth and at the surface, and to assess their relative importance as the subsidence evolves to a collapse. We also use the Boundary Element Method to build a numerical model of the experiment setup, which comprises contracting sill-like source in interaction with a ring-fault in elastic half-space. We then compare our results from these two approaches with the examples observed in nature. Our preliminary experimental and numerical results show that at the initial stage of magmatic withdrawal, when the ring-fault is not yet well formed, broad and smooth deflation dominates at the surface. As the withdrawal increases, narrower subsidence bowl develops accompanied by the upward propagation of the ring-faulting. This indicates that the broad deflation, affecting the entire volcano edifice, is primarily driven by the contraction of the

  6. High Ringxiety: Attachment Anxiety Predicts Experiences of Phantom Cell Phone Ringing.

    Science.gov (United States)

    Kruger, Daniel J; Djerf, Jaikob M

    2016-01-01

    Mobile cell phone users have reported experiencing ringing and/or vibrations associated with incoming calls and messages, only to find that no call or message had actually registered. We believe this phenomenon can be understood as a human signal detection issue, with potentially important influences from psychological attributes. We hypothesized that individuals higher in attachment anxiety would report more frequent phantom cell phone experiences, whereas individuals higher in attachment avoidance would report less frequent experiences. If these experiences are primarily psychologically related to attributes of interpersonal relationships, associations with attachment style should be stronger than for general sensation seeking. We also predicted that certain contexts would interact with attachment style to increase or decrease the likelihood of experiencing phantom cell phone calls and messages. Attachment anxiety directly predicted the frequency of phantom ringing and notification experiences, whereas attachment avoidance and sensation seeking did not directly predict frequency. Attachment anxiety and attachment avoidance interacted with contextual factors (expectations for a call or message and concerned about an issue that one may be contacted about) in the expected directions for predicting phantom cell phone experiences.

  7. Fast parallel ring recognition algorithm in the RICH detector of the CBM experiment at FAIR

    International Nuclear Information System (INIS)

    Lebedev, S.

    2011-01-01

    The Compressed Baryonic Matter (CBM)experiment at the future FAIR facility at Darmstadt will measure dileptons emitted from the hot and dense phase in heavy ion collisions. In case of an electron measurement, a high purity of identified electrons is required in order to suppress the background. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detector (TRD). Very fast data reconstruction is extremely important for CBM because of the huge amount of data which has to be handled. In this contribution, a parallelized ring recognition algorithm is presented. Modern CPUs have two features, which enable parallel programming. First, the SSE technology allows using the SIMD execution model. Second, multicore CPUs enable the use of multithreading. Both features have been implemented in the ring reconstruction of the RICH detector. A considerable speedup factor from 357 to 2.5 ms/event has been achieved including preceding code optimization for Intel Xeon X5550 processors at 2.67 GHz

  8. The role of visual and direct force feedback in robotics-assisted mitral valve annuloplasty.

    Science.gov (United States)

    Currie, Maria E; Talasaz, Ali; Rayman, Reiza; Chu, Michael W A; Kiaii, Bob; Peters, Terry; Trejos, Ana Luisa; Patel, Rajni

    2017-09-01

    The objective of this work was to determine the effect of both direct force feedback and visual force feedback on the amount of force applied to mitral valve tissue during ex vivo robotics-assisted mitral valve annuloplasty. A force feedback-enabled master-slave surgical system was developed to provide both visual and direct force feedback during robotics-assisted cardiac surgery. This system measured the amount of force applied by novice and expert surgeons to cardiac tissue during ex vivo mitral valve annuloplasty repair. The addition of visual (2.16 ± 1.67), direct (1.62 ± 0.86), or both visual and direct force feedback (2.15 ± 1.08) resulted in lower mean maximum force applied to mitral valve tissue while suturing compared with no force feedback (3.34 ± 1.93 N; P forces on cardiac tissue during robotics-assisted mitral valve annuloplasty suturing, force feedback may be required. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Development of RF-linac and storage ring system for high-current experiments at GSI

    International Nuclear Information System (INIS)

    Hofmann, I.

    1986-08-01

    The heavy ion facility under construction at GSI is suitable for the generation of high-current beams. It consists of a new high-current injector into the Unilac and a synchrotron and storage ring. We discuss the capability of this system to produce short pulses of heavy ions with a specific energy of the order of 0.1 MJ/g. Under these conditions the system allows to perform a first generation of heavy ion driven target experiments and to test most of the critical issues of a large scale heavy ion fusion driver facility. (orig.)

  10. Data Quality Monitoring : Automatic MOnitoRing Environment (AMORE ) Web Administration Tool in ALICE Experiment

    CERN Document Server

    Nagi, Imre

    2013-01-01

    ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). The quality of the acquired data evolves over time depending on the status of the detectors, its components and the operating environment. To get an excellent performance of detector, all detector configurations have to be set perfectly so that the data-taking can be done in an optimal way. This report describes a new implementation of the administration tools of the ALICE’s DQM framework called AMORE (Automatic MonitoRing Environment) with web technologies.

  11. Dielectronic recombination experiments with tungsten ions at the test storage ring and development of a single-particle detector at the cryogenic storage ring

    International Nuclear Information System (INIS)

    Spruck, Kaija

    2015-05-01

    This work is about electron-ion collision experiments at the ion storage rings of the Max Planck Institute for Nuclear Physics in Heidelberg. Absolute recombination rate coefficients of highly-charged tungsten ions featuring an open 4-f-shell structure have been measured at the heavy-ion storage ring TSR. The resulting plasma rate coefficients have been used to probe the significance of newly developed theoretical approaches. Plasma rate coefficients of highly-charged tungsten ions are in particular interesting for the development of plasma models for nuclear fusion reactors, since tungsten is a foreseeable impurity in the fusion plasma. In the relevant temperature range, the experimental results exceed the theoretical data used so far by up to a factor of 10, showing the need for more reliable theoretical calculations. Furthermore, based on the design of the detectors which have been used in the experiments at TSR, a movable single-particle detector for electron-ion recombination studies at the cryogenic storage ring CSR has been developed and installed within the scope of this work. The device has been designed specifically to meet the requirements of the CSR regarding low ion energies and cryogenic ambient temperature conditions. In a series of experiments, the detector was carefully characterised and successfully tested for its compatibility with these requirements. The detector was part of the infrastructure used for the room-temperature commissioning of CSR (2014) and is currently operated as a single-particle counter during the first cryogenic operation of CSR in 2015.

  12. Dielectronic recombination experiments with tungsten ions at the test storage ring and development of a single-particle detector at the cryogenic storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Spruck, Kaija

    2015-05-15

    This work is about electron-ion collision experiments at the ion storage rings of the Max Planck Institute for Nuclear Physics in Heidelberg. Absolute recombination rate coefficients of highly-charged tungsten ions featuring an open 4-f-shell structure have been measured at the heavy-ion storage ring TSR. The resulting plasma rate coefficients have been used to probe the significance of newly developed theoretical approaches. Plasma rate coefficients of highly-charged tungsten ions are in particular interesting for the development of plasma models for nuclear fusion reactors, since tungsten is a foreseeable impurity in the fusion plasma. In the relevant temperature range, the experimental results exceed the theoretical data used so far by up to a factor of 10, showing the need for more reliable theoretical calculations. Furthermore, based on the design of the detectors which have been used in the experiments at TSR, a movable single-particle detector for electron-ion recombination studies at the cryogenic storage ring CSR has been developed and installed within the scope of this work. The device has been designed specifically to meet the requirements of the CSR regarding low ion energies and cryogenic ambient temperature conditions. In a series of experiments, the detector was carefully characterised and successfully tested for its compatibility with these requirements. The detector was part of the infrastructure used for the room-temperature commissioning of CSR (2014) and is currently operated as a single-particle counter during the first cryogenic operation of CSR in 2015.

  13. Experiments with highly-charged heavy-ions performed at the storage ring ESR

    International Nuclear Information System (INIS)

    Mokler, P.H.

    1992-01-01

    The new heavy ion accelerator facility SIS/ESR was inaugurated in April 1990. During 1991 the experimental storage ring, ESR, has been commissioned. Highly-charged heavy ions from O 8+ up to Bi 82+ were successfully accumulated, cooled, and stored in the ring. Now all highly-charged, heavy ions can be provided for experiments at comfortable storage times and at energies roughly between 100 and 500 MeV/u. A report on the achievements and on the first experimental results will be given. For the experiments, special emphasis is put on capture processes in the electron cooler, i.e. on radiative and dielectronic recombination processes as well as on capture events of bound target electrons from a gas jet. In this case, the capture leads either directly (REC) or by cascading to X-ray emission, which is also exploited for a precision spectroscopy of the structure of the heaviest ions. Another exciting topic is the radioactive decay of highly charged ions: For instance the β-decay into bound atomic states, which is not possible for neutral atoms, was studied for stored naked Dy ions. (orig.)

  14. Rotating dust ring in an RF discharge coupled with a dc-magnetron sputter source. Experiment and simulation

    International Nuclear Information System (INIS)

    Matyash, K; Froehlich, M; Kersten, H; Thieme, G; Schneider, R; Hannemann, M; Hippler, R

    2004-01-01

    During an experiment involving coating of dust grains trapped in an RF discharge using a sputtering dc-magnetron source, a rotating dust ring was observed and investigated. After the magnetron was switched on, the dust cloud levitating above the RF electrode formed a ring rotating as a rigid body. Langmuir probe diagnostics were used for the measurement of plasma density and potential. It was discovered that the coupling of the dc-magnetron source to the RF discharge causes steep radial gradients in electron density and plasma potential. The rotation of the dust ring is attributed to the azimuthal component of the ion drag force, which appears due to the azimuthal drift of the ions caused by crossed radial electric and axial magnetic fields. In order to get more insight into the mechanism of dust ring rotation, a Particle-in-Cell simulation of a rotating dust cloud was performed. The results of the experiment and simulation are presented and discussed

  15. Rotating dust ring in an RF discharge coupled with a dc-magnetron sputter source. Experiment and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Matyash, K [Institut fuer Niedertemperaturplasmaphysik Greifswald, Fr.-L.-Jahn-Strasse 19, 17489 Greifswald (Germany); Froehlich, M [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, 17487 Greifswald (Germany); Kersten, H [Institut fuer Niedertemperaturplasmaphysik Greifswald, Fr.-L.-Jahn-Strasse 19, 17489 Greifswald (Germany); Thieme, G [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, 17487 Greifswald (Germany); Schneider, R [Max-Planck-Institut fuer Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstrasse 1, 17489 Greifswald (Germany); Hannemann, M [Institut fuer Niedertemperaturplasmaphysik Greifswald, Fr.-L.-Jahn-Strasse 19, 17489 Greifswald (Germany); Hippler, R [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet Greifswald, Domstrasse 10a, 17487 Greifswald (Germany)

    2004-10-07

    During an experiment involving coating of dust grains trapped in an RF discharge using a sputtering dc-magnetron source, a rotating dust ring was observed and investigated. After the magnetron was switched on, the dust cloud levitating above the RF electrode formed a ring rotating as a rigid body. Langmuir probe diagnostics were used for the measurement of plasma density and potential. It was discovered that the coupling of the dc-magnetron source to the RF discharge causes steep radial gradients in electron density and plasma potential. The rotation of the dust ring is attributed to the azimuthal component of the ion drag force, which appears due to the azimuthal drift of the ions caused by crossed radial electric and axial magnetic fields. In order to get more insight into the mechanism of dust ring rotation, a Particle-in-Cell simulation of a rotating dust cloud was performed. The results of the experiment and simulation are presented and discussed.

  16. Global DC closed orbit correction experiments on the NSLS X-ray ring and SPEAR

    International Nuclear Information System (INIS)

    Chung, Y.; Decker, G.; Evans, K. Jr.; Safranek, J.; So, I.; Tang, Y.; Corbett, W.J.; Hettel, R.

    1993-01-01

    The global closed orbit correction experiments conducted on the NSLS X-ray ring and the SPEAR using the technique of singular value decomposition (SVD) are presented. The beam response matrix, defined as beam motion at beam position monitor (BPM) locations per unit kick by corrector magnets, was measured and then analyzed using SVD. The BPMs and correctors are reconfigured into open-quotes transformedclose quotes BPMs (t-BPMs) and open-quotes transformedclose quotes correctors (t-correctors), with each T-BPM coupled to at most one t-corrector and vice versa for orbit correction. The decoupled t-BPMs are used to estimate the limit on orbit correction, while the decoupled t-correctors are used to optimize the corrector strengths. As a result the vertical r.m.s. orbit error at the BPM locations was reduced from 208 μm to 61 μm about an arbitrary reference orbit in the NSLS X-ray ring. In SPEAR, the vertical closed orbit was brought to the BPM centers at the selected BPM locations with an r.m.s. error of 215 μm reduced from the initial 780 μm

  17. Small-gap undulator experiment on the NSLS X-ray Ring

    International Nuclear Information System (INIS)

    Stefan, P.M.; Krinsky, S.; Rakowsky, G.; Solomon, L.

    1995-01-01

    We report results of an on-going experiment being carried out in the X13 straight section of the NSLS X-ray Ring which explores the limits of the operation of small-gap undulators. In particular, we discuss measurements of stored electron beam lifetime as a function of the vertical aperture presented by a 4-jaw scraper or a variable-aperture vacuum vessel. At an electron beam current of 300 mA the variable-aperture vacuum chamber was closed to an inner aperture of 3.8 mm with no effect on the electron beam lifetime. Measurements of the output radiation spectrum of a 16 mm period undulator at a magnet gap of 7.5 mm are also described

  18. Prevalence, Predictors and Clinical Outcome of Residual Pulmonary Hypertension Following Tricuspid Annuloplasty.

    Science.gov (United States)

    Chen, Yan; Liu, Ju-Hua; Chan, Daniel; Sit, Ko-Yung; Wong, Chun-Ka; Ho, Kar-Lai; Ho, Lai-Ming; Zhen, Zhe; Lam, Yui-Ming; Lau, Chu-Pak; Au, Wing-Kok; Tse, Hung-Fat; Yiu, Kai-Hang

    2016-07-22

    Tricuspid annuloplasty is increasingly performed during left heart valve surgery, but the long-term clinical outcome postoperatively is not satisfactory. The aim of this study was to determine whether residual pulmonary hypertension (PHT) contributes to the adverse outcome. One-hundred thirty-seven patients (age 61±11 years; men, 30%) who underwent tricuspid annuloplasty during left-side valve surgery were enrolled. The mean pulmonary artery systolic pressure before surgery was 49±13 mm Hg and 32±15 mm Hg following surgery. Patients were divided into 3 groups according to postoperative pulmonary artery systolic pressure: no residual PHT (n=78, 57%), mild residual PHT (n=43, 31%), or significant residual PHT (n=16, 12%). A preoperative larger right ventricular (RV) geometry and tricuspid valve tethering area were associated with mild or significant residual PHT. A total of 24 adverse events (20 heart failures and 4 cardiovascular deaths) occurred during a median follow-up of 25 months. Kaplan-Meier survival curve demonstrated that patients with significant residual PHT had the highest percentage of adverse events followed by those with mild residual PHT. Patients with no residual PHT had a very low risk of adverse events. Multivariable Cox regression analysis revealed that both mild (hazard ratio=4.94; 95% CI =1.34-18.16; P=0.02) and significant residual PHT (hazard ratio=8.67; 95% CI =2.43-30.98; P<0.01) were independent factors associated with adverse events. The present study demonstrated that 43% of patients who underwent tricuspid annuloplasty had residual PHT. The presence of mild or significant residual PHT was associated with adverse events in these patients. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  19. A small-angle camera for resonant scattering experiments at the storage ring DORIS

    International Nuclear Information System (INIS)

    Stuhrmann, H.B.; Gabriel, A.

    1983-01-01

    Resonant small-angle scattering is measured routinely in the wavelength range of 0.6 to 3.25 A with the instrument X15 at the storage ring DORIS. The monochromatic beam with a vertical offset of 1.22 m is achieved by a double monochromator system with a constant exit slit. The small-angle instrument allows for sample-detector distances between 0.37 and 7.33 m. A multiwire proportional counter with a sensitive area of 200 X 200 mm detects the scattered intensity with a spatial resolution of 2 X 2 mm. Its sensitivity can be adapted to the requirements of the experiment by activating a drift chamber of 8 cm depth at the back end of the detector. The performance of the instrument as a function of the wavelength is described. The energy resolution is about 1 eV at the L 3 absorption edge of caesium, as shown by the resonant scattering of ferritin in 30% CsCl solution. (Auth.)

  20. Initial report on stress-corrosion-cracking experiments using Zircaloy-4 spent fuel cladding C-rings

    International Nuclear Information System (INIS)

    Smith, H.D.

    1988-09-01

    The Nevada Nuclear Waste Storage Investigations (NNWSI) Project is sponsoring C-ring stress corrosion cracking scoping experiments as a first step in evaluating the potential for stress corrosion cracking of spent fuel cladding in a potential tuff repository environment. The objective is to scope the approximate behavior so that more precise pressurized tube testing can be performed over an appropriate range of stress, without expanding the long-term effort needlessly. The experiment consists of stressing, by compression with a dead weight load, C-rings fabricated from spent fuel cladding exposed to an environment of Well J-13 water held at 90/degree/C. The results indicate that stress corrosion cracking occurs at the high stress levels employed in the experiments. The cladding C-rings, tested at 90% of the stress at which elastic behavior is obtained in these specimens, broke in 25 to 64 d when tested in water. This was about one third of the time required for control tests to break in air. This is apparently the first observation of stress corrosion under the test conditions of relatively low temperature, benign environment but very high stress. The 150 ksi test stress could be applied as a result of the particular specimen geometry. By comparison, the uniaxial tensile yield stress is about 100 to 120 ksi and the ultimate stress is about 150 ksi. When a general model that fits the high stress results is extrapolated to lower stress levels, it indicates that the C-rings in experiments now running at /approximately/80% of the yield strength should take 200 to 225 d to break. 21 refs., 24 figs., 5 tabs

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  2. Ion optics and beam dynamics optimization at the HESR storage ring for the SPARC experiments with highly charged heavy ions

    International Nuclear Information System (INIS)

    Kovalenko, Oleksandr

    2015-01-01

    The High-Energy Storage Ring (HESR) is a part of an upcoming International Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt. A key part of a scientific program, along with antiproton physics, will be physics with highly-charged heavy ions. Phase-space cooled beams together with fixed internal target will provide an excellent environment for storage ring experiments at the HESR for the SPARC collaboration. Until recently, however, the existing ion optical lattice for the HESR was designed only for the experiments with antiproton beams. The thesis presents a new ion optical mode developed specifically for the operation of the HESR with highly charged heavy ions. The presence of the errors, such as beam momentum spread, magnetic field impurities or magnets misalignments, leads to disruption of beam dynamics: exciting of resonant motion and loss of beam stability. Within the paper, these effects are investigated with the help of numerical codes for particle accelerator design and simulation MAD-X and MIRKO. A number of correction techniques are applied to minimize the nonlinear impact on the beam dynamics and improve the experimental conditions. The application of the analytical and numerical tools is demonstrated in the experiment with uranium U 90+ beam at the existing storage ring ESR, GSI.

  3. Ion optics and beam dynamics optimization at the HESR storage ring for the SPARC experiments with highly charged heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Kovalenko, Oleksandr

    2015-06-24

    The High-Energy Storage Ring (HESR) is a part of an upcoming International Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt. A key part of a scientific program, along with antiproton physics, will be physics with highly-charged heavy ions. Phase-space cooled beams together with fixed internal target will provide an excellent environment for storage ring experiments at the HESR for the SPARC collaboration. Until recently, however, the existing ion optical lattice for the HESR was designed only for the experiments with antiproton beams. The thesis presents a new ion optical mode developed specifically for the operation of the HESR with highly charged heavy ions. The presence of the errors, such as beam momentum spread, magnetic field impurities or magnets misalignments, leads to disruption of beam dynamics: exciting of resonant motion and loss of beam stability. Within the paper, these effects are investigated with the help of numerical codes for particle accelerator design and simulation MAD-X and MIRKO. A number of correction techniques are applied to minimize the nonlinear impact on the beam dynamics and improve the experimental conditions. The application of the analytical and numerical tools is demonstrated in the experiment with uranium U{sup 90+} beam at the existing storage ring ESR, GSI.

  4. Bunch coalescing and bunch rotation in the Fermilab Main Ring: Operational experience and comparison with simulations

    International Nuclear Information System (INIS)

    Martin, P.S.; Wildman, D.W.

    1988-01-01

    The Fermilab Tevatron I proton-antiproton collider project requires that the Fermilab Main Ring produce intense bunches of protons and antiprotons for injection into the Tevatron. The process of coalescing a small number of harmonic number h=1113 bunches into a single bunch by bunch-rotating in a lower harmonic rf system is described.The Main Ring is also required to extract onto the antiproton production target bunches with as narrow a time spread as possible. This operation is also discussed. The operation of the bunch coalescing and bunch rotation are compared with simulations using the computer program ESME. 2 refs., 8 figs

  5. Ring Theory

    CERN Document Server

    Jara, Pascual; Torrecillas, Blas

    1988-01-01

    The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

  6. OEDGE modeling for the planned tungsten ring experiment on DIII-D

    Directory of Open Access Journals (Sweden)

    J.D. Elder

    2017-08-01

    Full Text Available The OEDGE code is used to model tungsten erosion and transport for experiments with toroidal rings of high-Z metal tiles in the DIII-D tokamak. Such modeling is needed for both experimental and diagnostic design to have estimates of the expected core and edge tungsten density and to understand the various factors contributing to the uncertainties in these calculations. OEDGE simulations are performed using the planned experimental magnetic geometries and plasma conditions typical of both L-mode and inter-ELM H-mode discharges in DIII-D. OEDGE plasma reconstruction based on specific representative discharges for similar geometries is used to determine the plasma conditions applied to tungsten plasma impurity simulations. A new model for tungsten erosion in OEDGE was developed which imports charge-state resolved carbon impurity fluxes and impact energies from a separate OEDGE run which models the carbon production, transport and deposition for the same plasma conditions as the tungsten simulations. These values are then used to calculate the gross tungsten physical sputtering due to carbon plasma impurities which is then added to any sputtering by deuterium ions; tungsten self-sputtering is also included. The code results are found to be dependent on the following factors: divertor geometry and closure, the choice of cross-field anomalous transport coefficients, divertor plasma conditions (affecting both tungsten source strength and transport, the choice of tungsten atomic physics data used in the model (in particular ionization rate for W-atoms, and the model of the carbon flux and energy used for calculating the tungsten source due to sputtering. Core tungsten density is found to be of order 1015m−3 (excluding effects of any core transport barrier and with significant variability depending on the other factors mentioned with density decaying into the scrape off layer. For the typical core density in the plasma conditions examined of 2 to 4

  7. The soil apparent infiltrability observed with ponded infiltration experiment in a permanent grid of infiltration rings

    Czech Academy of Sciences Publication Activity Database

    Votrubová, J.; Jelínková, V.; Němcová, R.; Tesař, Miroslav; Vogel, T.; Císlerová, M.

    2010-01-01

    Roč. 12, - (2010), s. 11898 ISSN 1607-7962. [European Geosciences Union General Assembly 2010. 02.05.2010-07.05.2010, Wienna] R&D Projects: GA ČR GA205/08/1174 Institutional research plan: CEZ:AV0Z20600510 Keywords : soil hydraulic conductivity * infiltration * infiltration ring Subject RIV: DA - Hydrology ; Limnology

  8. Folded Fabry-Perot quasi-optical ring resonator diplexer Theory and experiment

    Science.gov (United States)

    Pickett, H. M.; Chiou, A. E. T.

    1983-01-01

    Performance of folded Fabry-Perot quasi-optical ring resonator diplexers with different geometries of reflecting surfaces is investigated both theoretically and experimentally. Design of optimum surface geometry for minimum diffraction, together with the figure of merit indicating improvement in performance, are given.

  9. Early experience of the compression anastomosis ring (CARTM 27) in left-sided colon resection

    Science.gov (United States)

    Lee, Jung-Yeon; Woo, Jin-Hee; Choi, Hong-Jo; Park, Ki-Jae; Roh, Young-Hoon; Kim, Ki-Han; Lee, Hak-Yoon

    2011-01-01

    AIM: To evaluate clinical validity of the compression anastomosis ring (CAR™ 27) anastomosis in left-sided colonic resection. METHODS: A non-randomized prospective data collection was performed for patients undergoing an elective left-sided colon resection, followed by an anastomosis using the CAR™ 27 between November 2009 and January 2011. Eligibility criteria of the use of the CAR™ 27 were anastomoses between the colon and at or above the intraperitoneal rectum. The primary short-term clinical endpoint, rate of anastomotic leakage, and other clinical outcomes, including intra- and postoperative complications, length of operation time and hospital stay, and the ring elimination time were evaluated. RESULTS: A total of 79 patients (male, 43; median age, 64 years) underwent an elective left-sided colon resection, followed by an anastomosis using the CAR™ 27. Colectomy was performed laparoscopically in 70 patients, in whom two patients converted to open procedure (2.9%). There was no surgical mortality. As an intraoperative complication, total disruption of the anastomosis occurred by premature enforced tension on the proximal segment of the anastomosis in one patient. The ring was removed and another new CAR™ 27 anastomosis was constructed. One patient with sigmoid colon cancer showed postoperative anastomotic leakage after 6 d postoperatively and temporary diverting ileostomy was performed. Exact date of expulsion of the ring could not be recorded because most patients were not aware that the ring had been expelled. No patients manifested clinical symptoms of anastomotic stricture. CONCLUSION: Short-term evaluation of the CAR™ 27 anastomosis in elective left colectomy suggested it to be a safe and efficacious alternative to the standard hand-sewn or stapling technique. PMID:22147979

  10. Early experience of the compression anastomosis ring (CAR™ 27) in left-sided colon resection.

    Science.gov (United States)

    Lee, Jung-Yeon; Woo, Jin-Hee; Choi, Hong-Jo; Park, Ki-Jae; Roh, Young-Hoon; Kim, Ki-Han; Lee, Hak-Yoon

    2011-11-21

    To evaluate clinical validity of the compression anastomosis ring (CAR™ 27) anastomosis in left-sided colonic resection. A non-randomized prospective data collection was performed for patients undergoing an elective left-sided colon resection, followed by an anastomosis using the CAR™ 27 between November 2009 and January 2011. Eligibility criteria of the use of the CAR™ 27 were anastomoses between the colon and at or above the intraperitoneal rectum. The primary short-term clinical endpoint, rate of anastomotic leakage, and other clinical outcomes, including intra- and postoperative complications, length of operation time and hospital stay, and the ring elimination time were evaluated. A total of 79 patients (male, 43; median age, 64 years) underwent an elective left-sided colon resection, followed by an anastomosis using the CAR™ 27. Colectomy was performed laparoscopically in 70 patients, in whom two patients converted to open procedure (2.9%). There was no surgical mortality. As an intraoperative complication, total disruption of the anastomosis occurred by premature enforced tension on the proximal segment of the anastomosis in one patient. The ring was removed and another new CAR™ 27 anastomosis was constructed. One patient with sigmoid colon cancer showed postoperative anastomotic leakage after 6 d postoperatively and temporary diverting ileostomy was performed. Exact date of expulsion of the ring could not be recorded because most patients were not aware that the ring had been expelled. No patients manifested clinical symptoms of anastomotic stricture. Short-term evaluation of the CAR™ 27 anastomosis in elective left colectomy suggested it to be a safe and efficacious alternative to the standard hand-sewn or stapling technique.

  11. An experiment to study CP violation in the B system using an internal target at the HERA proton ring

    International Nuclear Information System (INIS)

    Hofmann, W.

    1993-03-01

    A group of physicists centered around the ARGUS collaboration got interested in hadron accelerators as a prolific source of B hadrons. The group is presently studying the option of a major-B-physics experiment to be performed at the HERA proton storage ring in fixed target mode using an internal target. Basic goal of the experiment is the detection of CP violation in the 'gold plated' B 0 → J/Ψ K s decay mode, using a dedicated detector triggered on lepton pairs from J/Ψ decay. (orig./HSI)

  12. De Vega Annuloplasty for Functional Tricupsid Regurgitation: Concept of Tricuspid Valve Orifice Index to Optimize Tricuspid Valve Annular Reduction

    Science.gov (United States)

    Hwang, Ho Young; Chang, Hyoung Woo; Jeong, Dong Seop

    2013-01-01

    We evaluated long-term results of De Vega annuloplasty measured by cylindrical sizers for functional tricuspid regurgitation (FTR) and analyzed the impact of measured annular size on the late recurrence of tricuspid valve regurgitation. Between 2001 and 2011, 177 patients (57.9±10.5 yr) underwent De Vega annuloplasty for FTR. Three cylindrical sizers (actual diameters of 29.5, 31.5, and 33.5 mm) were used to reproducibly reduce the tricuspid annulus. Long-term outcomes were evaluated and risk factor analyses for the recurrence of FTR ≥3+ were performed. Measured annular diameter indexed by patient's body surface area was included in the analyses as a possible risk factor. Operative mortality occurred in 8 patients (4.5%). Ten-year overall and cardiac death-free survivals were 80.5% and 90.8%, respectively. Five and 10-yr freedom rates from recurrent FTR were 96.5% and 93.1%, respectively. Cox proportional hazard model revealed that higher indexed annular size was the only risk factor for the recurrence of FTR (P=0.006). A minimal P value approach demonstrated that indexed annular diameter of 22.5 mm/m2 was a cut-off value predicting the recurrence of FTR. De Vega annuloplasty for FTR results in low rates of recurrent FTR in the long-term. Tricuspid annulus should be reduced appropriately considering patients' body size to prevent recurrent FTR. PMID:24339705

  13. Modular focusing ring imaging Cherenkov detector for electron-ion collider experiments

    Science.gov (United States)

    Wong, C. P.; Alfred, M.; Allison, L.; Awadi, M.; Azmoun, B.; Barbosa, F.; Barion, L.; Bennett, J.; Brooks, W.; Butler, C.; Cao, T.; Chiu, M.; Cisbani, E.; Contalbrigo, M.; Datta, A.; Del Dotto, A.; Demarteau, M.; Durham, J. M.; Dzhygadlo, R.; Elder, T.; Fields, D.; Furletova, Y.; Gleason, C.; Grosse-Perdekamp, M.; Harris, J.; Haseler, T. O. S.; He, X.; van Hecke, H.; Horn, T.; Hruschka, A.; Huang, J.; Hyde, C.; Ilieva, Y.; Kalicy, G.; Kimball, M.; Kistenev, E.; Kulinich, Y.; Liu, M.; Majka, R.; McKisson, J.; Mendez, R.; Nadel-Turonski, P.; Park, K.; Peters, K.; Rao, T.; Pisani, R.; Qiang, Y.; Rescia, S.; Rossi, P.; Sarajlic, O.; Sarsour, M.; Schwarz, C.; Schwiening, J.; da Silva, C. L.; Smirnov, N.; Stien, H. D.; Stevens, J.; Sukhanov, A.; Syed, S.; Tate, A. C.; Toh, J.; Towell, C. L.; Towell, R. S.; Tsang, T.; Turisini, M.; Wagner, R.; Wang, J.; Woody, C.; Xi, W.; Xie, J.; Zhao, Z. W.; Zihlmann, B.; Zorn, C.

    2017-11-01

    A powerful new electron-ioncollider (EIC) has been recommended in the 2015 Long Range Plan for Nuclear Science for probing the partonic structure inside nucleons and nuclei with unprecedented precision and versatility [1]. EIC detectors are currently under development [2], all of which require hadron identification over a broad kinematic range. A prototype ring imaging Cherenkov detector has been developed for hadron identification in the momentum range from 3 GeV/c to 10 GeV/c. The key feature of this new detector is a compact and modular design, achieved by using aerogel as radiator and a Fresnel lens for ring focusing. In this paper, the results from a beam test of a prototype device at Fermilab are reported.

  14. Present status of storage ring free electron laser experiment at ETL

    International Nuclear Information System (INIS)

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

    1988-01-01

    Outline is described of the present status of the ETL storage-ring free electron laser project. The structure and the performance of the ETL-type transverse optical klystron are given. A modification of the dispersive section has decreased the degradation of the shape of the spontaneous-emission spectrum due to energy spread of the electron beam. Relevant parameters of the stored beam are presented. Measurement of the optical-cavity loss is under way. (author)

  15. Storage Rings

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

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

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

    International Nuclear Information System (INIS)

    Schiffer, J.P.

    1994-01-01

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

  17. Angular distribution of Pionization particles from experiments on CERN-storage rings

    CERN Document Server

    Jabs, A

    1972-01-01

    The angular distribution of secondary charged particles arising from high energy interaction in the CERN storage rings has been measured. The measurements near the centre-of-mass energies (20-50) GeV have been taken in the angle range of 20-90 degrees relative to the recoil axis. A complex formula is suggested to explain the variations described experimentally. Good agreement between the theoretical and experimental data is found. Simplifications are possible in the formula which allow the two-centre emission structure to be explained. It is shown that the angular dependence cannot be explained solely from rotary impulse behaviour. (9 refs).

  18. Highly optimized tunable Er3+-doped single longitudinal mode fiber ring laser, experiment and model

    DEFF Research Database (Denmark)

    Poulsen, Christian; Sejka, Milan

    1993-01-01

    A continuous wave (CW) tunable diode-pumped Er3+-doped fiber ring laser, pumped by diode laser at wavelengths around 1480 nm, is discussed. Wavelength tuning range of 42 nm, maximum slope efficiency of 48% and output power of 14.4 mW have been achieved. Single longitudinal mode lasing...... with a linewidth of 6 kHz has been measured. A fast model of erbium-doped fiber laser was developed and used to optimize output parameters of the laser...

  19. Operating experience with high beam currents and transient beam loading in the SLC damping rings

    International Nuclear Information System (INIS)

    Minty, M.G.; Akre, R.; Krejcik, P.; Siemann, R.H.

    1995-01-01

    During the 1994 SLC run the nominal operating intensity in the damping rings was raised from 3.5 x 10 10 to greater than 4 x 10 10 particles per bunch (ppb). Stricter regulation of rf system parameters was required to maintain stability of the rf system and particle beam. Improvements were made in the feedback loops which control the cavity amplitude and loading angles. Compensation for beam loading was also required to prevent klystron saturation during repetition rate changes. To minimize the effects of transient loading on the rf system, the gain of the direct rf feedback loop and the loading angles were optimized

  20. Modeling and Experiments on Injection into University of Maryland Electron Ring

    International Nuclear Information System (INIS)

    Bai, G.; Kishek, R. A.; Beaudoin, B.; Bernal, S.; Feldman, D.; Godlove, T.; Haber, I.; Quinn, B.; Reiser, M.; Sutter, D.; Walter, M.; O'Shea, P. G.

    2006-01-01

    The University of Maryland Electron Ring (UMER) is built as a low-cost testbed for intense beam physics for benefit of larger ion accelerators. The beam intensity is designed to be variable, spanning the entire range from low current operation to highly space-charge-dominated transport. The ring has been closed and multi-turn commissioning has begun. One of the biggest challenges of multi-turn operation of UMER is correctly operating the Y-shaped injection/recirculation section, which is specially designed for UMER multi-turn operation. It is a challenge because the system requires several quadrupoles and dipoles in a very stringent space, resulting in mechanical, electrical, and beam control complexities. Also, the Earth's magnetic field and the image charge effects have to be investigated because they are strong enough to impact the beam centroid motion. This paper presents both simulation and experimental study of the beam centroid motion in the injection region to address above issues

  1. Corrections for a constant radial magnetic field in the muon g - 2 and electric-dipole-moment experiments in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Silenko, Alexander J. [Belarusian State University, Research Institute for Nuclear Problems, Minsk (Belarus); Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation)

    2017-10-15

    We calculate the corrections for constant radial magnetic field in muon g - 2 and electric-dipole-moment experiments in storage rings. While the correction is negligible for the current generation of g - 2 experiments, it affects the upcoming muon electric-dipole-moment experiment at Fermilab. (orig.)

  2. Corrections for a constant radial magnetic field in the muon \\varvec{g}-2 and electric-dipole-moment experiments in storage rings

    Science.gov (United States)

    Silenko, Alexander J.

    2017-10-01

    We calculate the corrections for constant radial magnetic field in muon {g}-2 and electric-dipole-moment experiments in storage rings. While the correction is negligible for the current generation of {g}-2 experiments, it affects the upcoming muon electric-dipole-moment experiment at Fermilab.

  3. Experience with the New Digital RF Control System at the CESR Storage Ring

    CERN Document Server

    Liepe, Matthias; Dobbins, John; Kaplan, Roger; Strohman, Charles R; Stuhl, Benjamin K

    2005-01-01

    A new digital control system has been developed, providing great flexibility, high computational power and low latency for a wide range of control and data acquisition applications. This system is now installed in the CESR storage ring and stabilizes the vector sum field of two of the superconducting CESR 500 MHz cavities and the output power from the driving klystron. The installed control system includes in-house developed digital and RF hardware, very fast feedback and feedforward control, a state machine for automatic start-up and trip recovery, cw and pulsed mode operation, fast quench detection, and cavity frequency control. Several months of continuous operation have proven high reliability of the system. The achieved field stability surpasses requirements.

  4. Phase-Space Tomography of Giant Pulses in Storage Ring FEL Theory and Experiment

    CERN Document Server

    Chalut, K

    2005-01-01

    The use of giant pulses in storage ring FEL provides for high peak power at the fundamental wavelength and for effective generating of high VUV harmonics. This process is accompanied by a complex nonlinear dynamics of electron beam, which cannot be described by simple models. In this paper we compare the results of numerical simulations, performed by self-consistent #uvfel code, with experimental observations of electron beam evolution in the longitudinal phase space. The evolution of the electron beam distribution was obtained from the images recorded by dual-sweep streak-camera. The giant pulse process occurs on a short fast time scale compared with synchrotron oscillation period, which make standard methods of tomography inapplicable. We had developed a novel method of reconstruction, an SVD-Based Phase-Space Tomography, which allows to reconstruct phase space distribution from as few as two e-bunch profiles separated by about 3 degrees of rotation in the phase space. This technique played critical role in...

  5. R6 validation exercise: through thickness residual stress measurements on an experiment test vessel ring

    International Nuclear Information System (INIS)

    Mitchell, D.H.

    1988-06-01

    A series of bursting tests on thick-walled pressure vessels has been carried out as part of a validation exercise for the CEGB R6 failure assessment procedure. The objective of these tests was the examination of the behaviour of typical PWR primary vessel material subject to residual stresses in addition to primary loading with particular reference to the R6 assessment procedure. To this end, a semi-elliptic part-through defect was sited in the vessel longitudinal seam, which was a submerged arc weld in the non stress-relieved condition; it was then pressure tested to failure. Prior to the final assembly of this vessel, a ring of material was cut from it to act as a test-piece on which a residual stress survey could be made. Surface measurements using the centre-hole technique were made by CERL personnel, and this has been followed by two through- thickness measurements at BNL using the deep-hole technique. This paper describes these deep-hole measurements and presents the results from them. (author)

  6. Experience with the biofragmentable anastomotic ring (BAR) in bowel preoperatively irradiated with 6000 rad

    Energy Technology Data Exchange (ETDEWEB)

    Croston, J.K.; Jacobs, D.M.; Kelly, P.H.; Feeney, D.A.; Johnston, G.R.; Strom, R.L.; Bubrick, M.P. (Hennepin County Medical Center, Minneapolis, MN (USA))

    1990-03-01

    Previous studies from the authors' laboratory using the biodegradable anastomotic ring (BAR) have demonstrated the safety of this device in animals irradiated preoperatively with the equivalent of 5000 rad; sutured, stapled, and BAR anastomoses all had leak rates of 10 percent or less in this setting. This study was undertaken to assess the safety of the BAR after irradiation with the equivalent of 6000 rad. Thirteen mongrel dogs underwent preoperative irradiation to the rectum and rectosigmoid, receiving 6000 rad according to the nominal standard dose equation. After a three-week rest period, each dog underwent anterior resection of the rectosigmoid and anastomosis with the BAR. The anastomoses were evaluated for early and late healing and anastomotic leaks. The results were compared with previous data from the authors' laboratory using an identical model. Radiographic leaks were found in 7 of 10 sutured anastomoses, 8 of 10 stapled anastomoses, and 3 of 13 BAR anastomoses (P less than 0.01). Comparative clinical leaks were 5 of 10 for sutured, 5 of 10 for stapled, and 3 of 13 for BAR anastomoses. These data suggest that the BAR may offer added safety to an anastomosis after preoperative irradiation. Whether this effect is due to the atraumatic technique of placing the device, improved blood flow to the anastomotic margins, or other factors, is still underdetermined.

  7. Experience with the biofragmentable anastomotic ring (BAR) in bowel preoperatively irradiated with 6000 rad

    International Nuclear Information System (INIS)

    Croston, J.K.; Jacobs, D.M.; Kelly, P.H.; Feeney, D.A.; Johnston, G.R.; Strom, R.L.; Bubrick, M.P.

    1990-01-01

    Previous studies from the authors' laboratory using the biodegradable anastomotic ring (BAR) have demonstrated the safety of this device in animals irradiated preoperatively with the equivalent of 5000 rad; sutured, stapled, and BAR anastomoses all had leak rates of 10 percent or less in this setting. This study was undertaken to assess the safety of the BAR after irradiation with the equivalent of 6000 rad. Thirteen mongrel dogs underwent preoperative irradiation to the rectum and rectosigmoid, receiving 6000 rad according to the nominal standard dose equation. After a three-week rest period, each dog underwent anterior resection of the rectosigmoid and anastomosis with the BAR. The anastomoses were evaluated for early and late healing and anastomotic leaks. The results were compared with previous data from the authors' laboratory using an identical model. Radiographic leaks were found in 7 of 10 sutured anastomoses, 8 of 10 stapled anastomoses, and 3 of 13 BAR anastomoses (P less than 0.01). Comparative clinical leaks were 5 of 10 for sutured, 5 of 10 for stapled, and 3 of 13 for BAR anastomoses. These data suggest that the BAR may offer added safety to an anastomosis after preoperative irradiation. Whether this effect is due to the atraumatic technique of placing the device, improved blood flow to the anastomotic margins, or other factors, is still underdetermined

  8. Black rings

    International Nuclear Information System (INIS)

    Emparan, Roberto; Reall, Harvey S

    2006-01-01

    A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

  9. White Ring; White ring

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)

    1998-01-05

    White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.

  10. Manifestations of geometric phases in a proton electric-dipole-moment experiment in an all-electric storage ring

    Science.gov (United States)

    Silenko, Alexander J.

    2017-12-01

    We consider a proton electric-dipole-moment experiment in an all-electric storage ring when the spin is frozen and local longitudinal and vertical electric fields alternate. In this experiment, the geometric (Berry) phases are very important. Due to the these phases, the spin rotates about the radial axis. The corresponding systematic error is rather important while it can be canceled with clockwise and counterclockwise beams. The geometric phases also lead to the spin rotation about the radial axis. This effect can be canceled with clockwise and counterclockwise beams as well. The sign of the azimuthal component of the angular velocity of the spin precession depends on the starting point where the spin orientation is perfect. The radial component of this quantity keeps its value and sign for each starting point. When the longitudinal and vertical electric fields are joined in the same sections without any alternation, the systematic error due to the geometric phases does not appear but another systematic effect of the spin rotation about the azimuthal axis takes place. It has opposite signs for clockwise and counterclockwise beams.

  11. Ring closure in actin polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Supurna, E-mail: supurna@rri.res.in [Raman Research Institute, Bangalore 560080 (India); Chattopadhyay, Sebanti [Doon University, Dehradun 248001 (India)

    2017-03-18

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers. - Highlights: • Ring closure of biopolymers. • Worm like chain model. • Predictions for experiments.

  12. Transcatheter pledget-assisted suture tricuspid annuloplasty (PASTA) to create a double-orifice valve.

    Science.gov (United States)

    Khan, Jaffar M; Rogers, Toby; Schenke, William H; Greenbaum, Adam B; Babaliaros, Vasilis C; Paone, Gaetano; Ramasawmy, Rajiv; Chen, Marcus Y; Herzka, Daniel A; Lederman, Robert J

    2018-02-06

    Pledget-assisted suture tricuspid valve annuloplasty (PASTA) is a novel technique using marketed equipment to deliver percutaneous trans-annular sutures to create a double-orifice tricuspid valve. Tricuspid regurgitation is a malignant disease with high surgical mortality and no commercially available transcatheter solution in the US. Two iterations of PASTA were tested using trans-apical or trans-jugular access in swine. Catheters directed paired coronary guidewires to septal and lateral targets on the tricuspid annulus under fluoroscopic and echocardiographic guidance. Guidewires were electrified to traverse the annular targets and exchanged for pledgeted sutures. The sutures were drawn together and knotted, apposing septal and lateral targets, creating a double orifice tricuspid valve. Twenty-two pigs underwent PASTA. Annular and chamber dimensions were reduced (annular area, 10.1 ± 0.8 cm 2 to 3.8 ± 1.5 cm 2 (naïve) and 13.1 ± 1.5 cm 2 to 6.2 ± 1.0 cm 2 (diseased); septal-lateral diameter, 3.9 ± 0.3 mm to 1.4 ± 0.6 mm (naïve) and 4.4 ± 0.4 mm to 1.7 ± 1.0 mm (diseased); and right ventricular end-diastolic volume, 94 ± 13 ml to 85 ± 14 ml (naïve) and 157 ± 25 ml to 143 ± 20 ml (diseased)). MRI derived tricuspid regurgitation fraction fell from 32 ± 12% to 4 ± 5%. Results were sustained at 30 days. Pledget pull-through force was five-fold higher (40.6 ± 11.7N vs 8.0 ± 2.6N, P PASTA reduces annular dimensions and tricuspid regurgitation in pigs. It may be cautiously applied to selected patients with severe tricuspid regurgitation and no options. This is the first transcatheter procedure, to our knowledge, to deliver standard pledgeted sutures to repair cardiac pathology. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

  13. Vortex rings

    CERN Document Server

    Akhmetov, D G

    2009-01-01

    This text on vortex rings covers their theoretical foundation, systematic investigations, and practical applications such as the extinction of fires at gushing oil wells. It pays special attention to the formation and motion of turbulent vortex rings.

  14. The Smart Ring Experience in l’Aquila (Italy: Integrating Smart Mobility Public Services with Air Quality Indexes

    Directory of Open Access Journals (Sweden)

    Maria-Gabriella Villani

    2016-12-01

    Full Text Available This work presents the “City Dynamics and Smart Environment” activities of the Smart Ring project, a model for the smart city, based on the integration of sustainable urban transport services and environmental monitoring over a 4–5-km circular path, the “Smart Ring”, around the historical center of l’Aquila (Italy. We describe our pilot experience performed during an experimental on-demand public service electric bus, “SmartBus”, which was equipped with a multi-parametric air quality low-cost gas electrochemical sensor platform, “NASUS IV”. For five days (28–29 August 2014 and 1–3 September 2014, the sensor platform was installed inside the SmartBus and measured air quality gas compounds (nitrogen dioxide, carbon oxide, sulfur dioxide, hydrogen sulfide during the service. Data were collected and analyzed on the bases of an air quality index, which provided qualitative insights on the air status potentially experienced by the users. The results obtained are in agreement with the synoptic meteorological conditions, the urban background air quality reference measurements and the potential traffic flow variations. Furthermore, they indicated that the air quality status was influenced by the gas component NO 2 , followed by H 2 S, SO 2 and CO. We discuss the features of our campaign, and we highlight the potential, limitations and key factors to consider for future project designs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-03-11

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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  17. Thin layer activation (TLA) experiment of piston ring F.J product by using nuclear facility proton beam 12.5 MeV

    International Nuclear Information System (INIS)

    Sudarmono; Silakhuddin

    2002-01-01

    The experiment of thin layer activation of piston ring F.J product, was done. The purpose of this experiment are to measure material wearing level by using concentration method. The experiment was carried out by activated piston ring proton beam with energy 12,5 MeV and beam current 1 μA for 30 minutes then was continued by wearing process. The measurement of the wear result activity was carried out by pouring the total of volume of lubricant oil for radioactivity measurement. Measurement of the activity level used the gamma spectroscopy. The minimum wearing duration that can detects a wear was 5 hours. The activity count was 1.230 pulse per 30 seconds which is in accordance with a wear in order of 8 mg of Fe material on 1 liter oil lubricant, this result is same with the result of T. Delvigne namely is less than 10 mgr

  18. Pseudo-single-bunch mode for a 100 MHz storage ring serving soft X-ray timing experiments

    Science.gov (United States)

    Olsson, T.; Leemann, S. C.; Georgiev, G.; Paraskaki, G.

    2018-06-01

    At many storage rings for synchrotron light production there is demand for serving both high-flux and timing users simultaneously. Today this is most commonly achieved by operating inhomogeneous fill patterns, but this is not preferable for rings that employ passive harmonic cavities to damp instabilities and increase Touschek lifetime. For these rings, inhomogeneous fill patterns could severely reduce the effect of the harmonic cavities. It is therefore of interest to develop methods to serve high-flux and timing users simultaneously without requiring gaps in the fill pattern. One such method is pseudo-single-bunch (PSB), where one bunch in the bunch train is kicked onto another orbit by a fast stripline kicker. The light emitted from the kicked bunch can then be separated by an aperture in the beamline. Due to recent developments in fast kicker design, PSB operation in multibunch mode is within reach for rings that operate with a 100 MHz RF system, such as the MAX IV and Solaris storage rings. This paper describes machine requirements and resulting performance for such a mode at the MAX IV 1.5 GeV storage ring. A solution for serving all beamlines is discussed as well as the consequences of beamline design and operation in the soft X-ray energy range.

  19. Resultado clínico tardio da anuloplastia mitral sem suporte em crianças e adolescentes Late outcome of unsupported annuloplasty as surgical treatment of mitral insufficiency in children and adolescents

    Directory of Open Access Journals (Sweden)

    Solange Bordignon

    1996-12-01

    sem suporte anular profético, com resultados tardios comparáveis àqueles obtidos por técnicas mais complexas. Isto tem importância no tratamento de crianças e adultos jovens, especialmente no sexo feminino, quando se deseja evitar o implante de próteses mecânicas.Late post-operative clinical results fortreatmentof mitral regurgitation (MR in patients under 18 years-old by annuloplasty without ring or posterior support are presented. From 1977 to 1995,70 patients: 36 female and 34 male, mean age 12.4 ± 4.8 y (6m to 18y, with pure MR were submitted to an Wooler type of annuloplasty. None received ring or annular support. Twelve (17.1% had chordal shortening associated. Ethiology was rheumatic 71.4%, congenital 18.6%, myxomatous 8.6% and infectious 1.4%. Preoperative functional class was II: 32 cases (45.7%, III: 18 (25.7%, IV: 20 (28.6%. Twenty-one patients (30% had associated procedures: on aortic valve 12 (15.2%, tricuspid 4 (5.7%, ASD 4 (5.7% and aortic and tricuspid 1 (1.4%. Mean perfusion time was 45.2 ± 18.3 min for the whole group and 37.2 ± 11.3 min for annuloplasty alone. Mean ischemic time was 28.4 ± 14.3 min and 21.8 ± 7.1 min respectively. Follow-up time ranged from 7 months to 18 years. Mortality was 4.3% (3 cases in the early postoperative and 8.6% (6 cases in the late follow up. Early residual regurgitation was found in 15 patients (21.4% and 50.0% in 35. Thirteen (18.6% were reoperated at a mean p.o. time of 56.2 ± 46.2 m. Causes for reoperation: primary MR 5 (38.5%, endocarditis 4 (30.7%, stenosis 2 (15.4%, aortic valve disfunction 1 (7.7%, pulmonary embolism 1 (7.7%. Late evaluation in 46 non-operated survivors: 34 were in functional class I (73.9%, 10 in II (21.7% and 2 in III (4.3%. Actuarial survival was 93 ± 3% at 5 years and 80 ± 7% at 10 years. Event-free survival was 89 ± 4% and 61 ± 10% at 5 and 10 years. For rheumatic ethiology, event-free survival was 80 ± 8% and 55 ± 16% and, for congenital MR, 90 ± 9% at 5 and 10 years

  20. Design, fabrication and characterization of multi-guard-ring furnished p+n-n+ silicon strip detectors for future HEP experiments

    Science.gov (United States)

    Lalwani, Kavita; Jain, Geetika; Dalal, Ranjeet; Ranjan, Kirti; Bhardwaj, Ashutosh

    2016-07-01

    Si detectors, in various configurations (strips and pixels), have been playing a key role in High Energy Physics (HEP) experiments due to their excellent vertexing and high precision tracking information. In future HEP experiments like upgrade of the Compact Muon Solenoid experiment (CMS) at the Large Hadron Collider (LHC), CERN and the proposed International Linear Collider (ILC), the Si tracking detectors will be operated in a very harsh radiation environment, which leads to both surface and bulk damage in Si detectors which in turn changes their electrical properties, i.e. change in the full depletion voltage, increase in the leakage current and decrease in the charge collection efficiency. In order to achieve the long term durability of Si-detectors in future HEP experiments, it is required to operate these detectors at very high reverse biases, beyond the full depletion voltage, thus requiring higher detector breakdown voltage. Delhi University (DU) is involved in the design, fabrication and characterization of multi-guard-ring furnished ac-coupled, single sided, p+n-n+ Si strip detectors for future HEP experiments. The design has been optimized using a two-dimensional numerical device simulation program (TCAD-Silvaco). The Si strip detectors are fabricated with eight-layers mask process using the planar fabrication technology by Bharat Electronic Lab (BEL), India. Further an electrical characterization set-up is established at DU to ensure the quality performance of fabricated Si strip detectors and test structures. In this work measurement results on non irradiated Si Strip detectors and test structures with multi-guard-rings using Current Voltage (IV) and Capacitance Voltage (CV) characterization set-ups are discussed. The effect of various design parameters, for example guard-ring spacing, number of guard-rings and metal overhang on breakdown voltage of test structures have been studied.

  1. GPU-based low-level trigger system for the standalone reconstruction of the ring-shaped hit patterns in the RICH Cherenkov detector of NA62 experiment

    International Nuclear Information System (INIS)

    Ammendola, R.; Biagioni, A.; Cretaro, P.; Frezza, O.; Cicero, F. Lo; Lonardo, A.; Martinelli, M.; Paolucci, P.S.; Pastorelli, E.; Chiozzi, S.; Ramusino, A. Cotta; Fiorini, M.; Gianoli, A.; Neri, I.; Lorenzo, S. Di; Fantechi, R.; Piandani, R.; Pontisso, L.; Lamanna, G.; Piccini, M.

    2017-01-01

    This project aims to exploit the parallel computing power of a commercial Graphics Processing Unit (GPU) to implement fast pattern matching in the Ring Imaging Cherenkov (RICH) detector for the level 0 (L0) trigger of the NA62 experiment. In this approach, the ring-fitting algorithm is seedless, being fed with raw RICH data, with no previous information on the ring position from other detectors. Moreover, since the L0 trigger is provided with a more elaborated information than a simple multiplicity number, it results in a higher selection power. Two methods have been studied in order to reduce the data transfer latency from the readout boards of the detector to the GPU, i.e., the use of a dedicated NIC device driver with very low latency and a direct data transfer protocol from a custom FPGA-based NIC to the GPU. The performance of the system, developed through the FPGA approach, for multi-ring Cherenkov online reconstruction obtained during the NA62 physics runs is presented.

  2. Heavy ion storage rings

    International Nuclear Information System (INIS)

    Schuch, R.

    1987-01-01

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

  3. Anuloplastia sem suporte para tratamento da insuficiência mitral reumática Non-supported mitral annuloplasty technique for treatment of rheumatic mitral insufficiency

    Directory of Open Access Journals (Sweden)

    Renato A. K Kalil

    1992-09-01

    sem suporte anular profético, com resultados tardios comparáveis àqueles obtidos por técnicas mais complexas. Isto tem importância no tratamento de crianças e adultos jovens, especialmente no sexo feminino, quando se deseja evitar implante de próteses mecânicas.Since 1974 a non-supported mitral annuloplasty technique has been employed for treatment of pure mitral regurgitation (PMR, in a population that was predominantly young and of rheumatic ethnology. An evaluation of late results forms the basis of this report. There were 154 patients operated on for PMR, 55 (36% male and 99 (64% female. Mean age was 36 ± 16 (5 to 73 years. Associated lesions were: 47 aortic, 21 tricuspid and 2 ASDs (atrial aptal defects. Cases with concomitant mitral stenosis were not included. Properative functional class was I-II in 19% and III-IV in 81%. The cardiothoracic ratio was 0.61 ± 0.10. All patients were submitted to an unsupported mitral annuloplastic procedure, similar to that described by WOOLER, that consisted in reduction of the mural portion of the annulus obtained with the application of two buttressed mattress sutures at the comissures without compromisse to the width of the septal leaflet. When necessary, additional chordal procedures were performed. No patients received ring or posterior annular support. Residual late systolic murmur was present in 48%. Late complications were: systemic thromboembolism 5.8% (1/3 with aortic prosthesis, infective endocardites 1.3% and pulmonary thromboembolism 0.7%. Postoperative functional class was I-II in 84% and III-IV in 16%. Cardiothoracic ratio was 0.58 ± 0.10. Actuarial probability of late survival was 79.5 ± 5.3% at 10 years and 71.0 ± 7.4% at 14 years. Event free survival was 67.9 ± 8.9% at 10 years and 56.1 ± 11.7% at 14 years. Rheumatic mitral regurgitation can be effectively treated by annuloplasty without prosthetic annular support with late results comparable to those obtained with more complicated procedures

  4. Anuloplastia de homoenxerto pulmonar criopreservado com anel de Delrin na atresia pulmonar com comunicação interventricular Annuloplasty of cryopreserved pulmonary homograft with Delrin stent in pulmonary atresia with ventricular septal defect

    Directory of Open Access Journals (Sweden)

    Ulisses Alexandre Croti

    2007-05-01

    Full Text Available Criança de seis anos portadora de atresia pulmonar com comunicação interventricular, submetida a correção total com um ano, empregando monoválvula de pericárdio bovino na reconstrução da via de saída do ventrículo direito. Evoluiu com importante regurgitação valvar pulmonar (RVP e disfunção do ventrículo direito. Na reoperação foi implantado homoenxerto pulmonar criopreservado (HPC com anuloplastia, utilizando anel de Delrin com o intuito de evitar distorção geométrica do conduto. Após dois anos, o ecocardiograma, semelhante ao pós-operatório imediato, demonstra RVP discreta e função ventricular direita normal, sugerindo que essa manobra pode ser utilizada como coadjuvante para otimizar o resultado do implante do HPC.A six-year-old child was suffering from pulmonary atresia with ventricular septal defect after a total correction at 1 year of age using a bovine pericardial monocusp valve in the reconstruction of the right ventricle outflow tract. The infant evolved with significant pulmonary valve regurgitation (PVR and right ventricle dysfunction. On reoperation, a cryopreserved pulmonary homograft (CPH was implanted with annuloplasty utilizing a Delrin ring with the aim of avoiding geometric distortion of the vessel. After two years, an echocardiogram proved a similar state to the immediate postoperative period with slight pulmonary valve regurgitation and normal right ventricular function suggesting that this maneuver may be used as coadjuvant treatment to optimize the result of CPH implantation.

  5. The development of highway nuisance perception. Experiences of residents along the Southern Ring Road in Groningen, the Netherlands.

    OpenAIRE

    Hamersma, M; Heinen, E; Tillema, T; Arts, J

    2017-01-01

    The perception of highway nuisance i.e. noises, air pollution and barrier-effects, is associated with negative effects on health and quality of life. This study aims to gain a deeper understanding of the development of highway nuisance perception among residents. Interviews were conducted with residents in 32 households living along the Southern Ring Road, a highway which crosses various neighbourhoods in the city of Groningen, the Netherlands. Various themes emerged from the interviews which...

  6. ring system

    African Journals Online (AJOL)

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

  7. Planetary Rings

    Science.gov (United States)

    Nicholson, P. D.

    2001-11-01

    A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the

  8. Study of Mn dissolution from LiMn{sub 2}O{sub 4} spinel electrodes using rotating ring-disk collection experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Li-Fang; Ou, Chin-Ching; Striebel, Kathryn A.; Chen, Jenn-Shing

    2003-07-01

    The goal of this research was to measure Mn dissolution from a thin porous spinel LiMn{sub 2}O{sub 4} electrode by rotating ring-disk collection experiments. The amount of Mn dissolution from the spinel LiMn{sub 2}O{sub 4} electrode under various conditions was detected by potential step chronoamperometry. The concentration of dissolved Mn was found to increase with increasing cycle numbers and elevated temperature. The dissolved Mn was not dependent on disk rotation speed, which indicated that the Mn dissolution from the disk was under reaction control. The in situ monitoring of Mn dissolution from the spinel was carried out under various conditions. The ring currents exhibited maxima corresponding to the end-of-charge (EOC) and end-of-discharge (EOD), with the largest peak at EOC. The results suggest that the dissolution of Mn from spinel LiMn{sub 2}O{sub 4} occurs during charge/discharge cycling, especially in a charged state (at >4.1 V) and in a discharged state (at <3.1 V). The largest peak at EOC demonstrated that Mn dissolution took place mainly at the top of charge. At elevated temperatures, the ring cathodic currents were larger due to the increase of Mn dissolution rate.

  9. Experience of usage of forming rings and protective caps made of PTFE on the single-component implants

    Directory of Open Access Journals (Sweden)

    S. A. Chertov

    2014-04-01

    Full Text Available Relevance. The main reason that limits the usage of single-component implants, as compared with collapsible (two-component implants is the high risk of infectious and inflammatory complications in the postoperative period and problems in prosthetics in the esthetically important areas. Therefore, the usage of elements that contribute to healing of the mucous membrane in the early stages of implantation is particularly up-to-date. Work objective is to determine the clinical effectiveness of usage of forming rings and protective caps made of PTFE on the single-component implants in the prevention of peri-implant pathology on a one-step surgical implantation. Materials and methods of the investigation. For this work we used the treatment results of 24 patients with various dentition defects. According to the single-component implant procedure 52 single-component implants were mounted. The head of monolithic implants (38 p. were isolated by rings or caps made of PTFE. For comparison, 14 implants remained bare for 2-6 weeks before the temporary prosthesis. Postoperatively, subjective feelings were noted in patients, the presence or absence of pain complaints during the examination and palpation, the nature and extent of edema, the phenomena of inflammation around the implant neck were checked. At the stage of sutures removal the degree of soft plaque deposits on the healing elements and titanium implant heads was assessed. Results of the investigation and their discussion. No effects of mucosal hyperemia around the supporting elements made of PTFE were revealed, there was no soft and hard plaque on the rings and caps in most patients of the main group. In patients of the control group, on the contrary, the appearance of the biofilm that covered the head and the implant shoulder on all abutments, which were not protected by a ring or cap, was noted. The healing period of mucous membrane in patients of the control group was longer, the quality of

  10. Topological rings

    CERN Document Server

    Warner, S

    1993-01-01

    This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

  11. Ring accelerators

    International Nuclear Information System (INIS)

    Gisler, G.; Faehl, R.

    1983-01-01

    We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package

  12. User evaluations offer promise for pod-intravaginal ring as a drug delivery platform: A mixed methods study of acceptability and use experiences.

    Science.gov (United States)

    Guthrie, Kate M; Rosen, Rochelle K; Vargas, Sara E; Getz, Melissa L; Dawson, Lauren; Guillen, Melissa; Ramirez, Jaime J; Baum, Marc M; Vincent, Kathleen L

    2018-01-01

    Effective HIV prevention requires efficient delivery of safe and efficacious drugs and optimization of user adherence. The user's experiences with the drug, delivery system, and use parameters are critical to product acceptability and adherence. Prevention product developers have the opportunity to directly control a drug delivery system and its impact on acceptability and adherence, as well as product efficacy. Involvement of potential users during preclinical design and development can facilitate this process. We embedded a mixed methods user evaluation study into a safety and pharmacokinetics (PK) trial of a pod-intravaginal ring delivering antiretroviral agents. Women enrolled in two cohorts, ultimately evaluating the safety/PK of a pod-IVRs delivering TDF-alone, TDF-FTC, and/or TDF-FTC-MVC. A 7-day use period was targeted for each pod-IVR, regardless of drug or drug combination. During the clinical study, participants provided both quantitative (i.e., survey) and qualitative (i.e., in-depth interview) data capturing acceptability, perceptibility, and adherence behaviors. Initial sexual and reproductive health history surveys, daily diaries, a final acceptability and willingness to use survey, and a qualitative in-depth interview comprised the user evaluation data for each pod-IVR experienced by the participants. Overall, the majority of participants (N = 10) reported being willing to use the pod-IVR platform for HIV prevention should it advance to market. Confidence to use the pod-IVR (e.g., insertion, removal) was high. There were no differences noted in the user experience of the pod-IVR platform; that is, whether the ring delivered TDF-alone, TDF-FTC, or TDF-FTC-MVC, users' experiences of the ring were similar and acceptable. Participants did report specific experiences, both sensory and behavioral, that impacted their use behaviors with respect to the ring, and which could ultimately impact acceptability and adherence. These experiences, and user

  13. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

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

  14. OPERATIONAL EXPERIENCE WITH FAST FIBER-OPTIC BEAM LOSS MONITORS FOR THE ADVANCED PHOTON SOURCE STORAGE RING SUPERCONDUCTING UNDULATORS

    Energy Technology Data Exchange (ETDEWEB)

    Dooling, J.; Harkay, K.; Sajaev, V.; Shang, H.

    2017-06-25

    Fast fiber-optic (FFO) beam loss monitors (BLMs) installed with the first two superconducting undulators (SCUs) in the Advanced Photon Source storage ring have proven to be a useful diagnostic for measuring deposited charge (energy) during rapid beam loss events. The first set of FFOBLMs were installed outside the cryostat of the short SCU, a 0.33-m long device, above and below the beam centerline. The second set are mounted with the first 1.1-mlong SCU within the cryostat, on the outboard and inboard sides of the vacuum chamber. The next 1.1-m-long SCU is scheduled to replace the short SCU later in 2016 and will be fitted with FFOBLMs in a manner similar to original 1.1-m device. The FFOBLMs were employed to set timing and voltage for the abort kicker (AK) system. The AK helps to prevent quenching of the SCUs during beam dumps [1] by directing the beam away from the SC magnet windings. The AK is triggered by the Machine Protection System (MPS). In cases when the AK fails to prevent quenching, the FFOBLMs show that losses often begin before detection by the MPS.

  15. Ground Movement in SSRL Ring

    International Nuclear Information System (INIS)

    Sunikumar, Nikita

    2011-01-01

    Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.

  16. Energy spectra of quantum rings.

    Science.gov (United States)

    Fuhrer, A; Lüscher, S; Ihn, T; Heinzel, T; Ensslin, K; Wegscheider, W; Bichler, M

    2001-10-25

    Quantum mechanical experiments in ring geometries have long fascinated physicists. Open rings connected to leads, for example, allow the observation of the Aharonov-Bohm effect, one of the best examples of quantum mechanical phase coherence. The phase coherence of electrons travelling through a quantum dot embedded in one arm of an open ring has also been demonstrated. The energy spectra of closed rings have only recently been studied by optical spectroscopy. The prediction that they allow persistent current has been explored in various experiments. Here we report magnetotransport experiments on closed rings in the Coulomb blockade regime. Our experiments show that a microscopic understanding of energy levels, so far limited to few-electron quantum dots, can be extended to a many-electron system. A semiclassical interpretation of our results indicates that electron motion in the rings is governed by regular rather than chaotic motion, an unexplored regime in many-electron quantum dots. This opens a way to experiments where even more complex structures can be investigated at a quantum mechanical level.

  17. Extending the applicability of an open-ring trap to perform experiments with a single laser-cooled ion

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo, J. M.; Colombano, M.; Doménech, J.; Rodríguez, D., E-mail: danielrodriguez@ugr.es [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, 18071 Granada (Spain); Block, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Helmholtz-Institut Mainz, 55099 Mainz (Germany); Institut für Kernchemie, University of Mainz, 55099 Mainz (Germany); Delahaye, P. [Grand Accélérateur National d’Ions Lourds, 14000 Caen (France)

    2015-10-15

    A special ion trap was initially built up to perform β-ν correlation experiments with radioactive ions. The trap geometry is also well suited to perform experiments with laser-cooled ions, serving for the development of a new type of Penning trap, in the framework of the project TRAPSENSOR at the University of Granada. The goal of this project is to use a single {sup 40}Ca{sup +} ion as detector for single-ion mass spectrometry. Within this project and without any modification to the initial electrode configuration, it was possible to perform Doppler cooling on {sup 40}Ca{sup +} ions, starting from large clouds and reaching single ion sensitivity. This new feature of the trap might be important also for other experiments with ions produced at radioactive ion beam facilities. In this publication, the trap and the laser system will be described, together with their performance with respect to laser cooling applied to large ion clouds down to a single ion.

  18. Planetary ring systems properties, structures, and evolution

    CERN Document Server

    Murray, Carl D

    2018-01-01

    Planetary rings are among the most intriguing structures of our solar system and have fascinated generations of astronomers. Collating emerging knowledge in the field, this volume reviews our current understanding of ring systems with reference to the rings of Saturn, Uranus, Neptune, and more. Written by leading experts, the history of ring research and the basics of ring–particle orbits is followed by a review of the known planetary ring systems. All aspects of ring system science are described in detail, including specific dynamical processes, types of structures, thermal properties and their origins, and investigations using computer simulations and laboratory experiments. The concluding chapters discuss the prospects of future missions to planetary rings, the ways in which ring science informs and is informed by the study of other astrophysical disks, and a perspective on the field's future. Researchers of all levels will benefit from this thorough and engaging presentation.

  19. Measurement of the ratio of C3+ and O4+ ions produced by ECRIS to prepare a laser cooling experiment at storage rings

    International Nuclear Information System (INIS)

    Zhu, X.L.; Wen, W.Q.; Ma, X.; Li, J.Y.; Feng, W.T.; Zhang, R.T.; Wang, Enliang; Yan, S.; Guo, D.L.; Hai, B.; Qian, D.B.; Zhang, P.; Xu, S.; Zhao, D.M.; Yang, J.; Zhang, D.C.; Li, B.; Gao, Y.; Huang, Z.K.; Wang, H.B.

    2014-01-01

    To prepare the upcoming laser cooling of relativistic C 3+ ion beams at the experimental Cooler Storage Ring (CSRe), a novel experiment was performed using a reaction microscope to determine the ratio of C 3+ ions in mixed ion beams of C 3+ and O 4+ that are produced by an Electron Cyclotron Resonance Ion Source (ECRIS). The mixed ion beams at an energy of 4 keV/u were directed to collide on a supersonic helium gas target. Using the single-electron capture channel and the coincidence technique, the fractions of C 3+ and O 4+ ions in the primary beam were obtained. Using different injection gases for ECRIS, including O 2 , CO, CO 2 , and CH 4 , at a fixed radio-frequency power of 300 W, the measured results showed that the fraction of C 3+ ions was greater than 70% for the injection gases of CO and CO 2 . These measured results are very important and helpful for the upcoming laser cooling experiments

  20. Polarized particles in storage rings

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  1. Implement of a magnetic spectrometer at the CERN intersecting stockage rings (900 spectrometer in the R608 experiment)

    International Nuclear Information System (INIS)

    Reyrolle, M.

    1985-01-01

    By adding a new spectrometer at 90 0 in the R608 experiment at CERN (ISR) we can search correlations between some systems of particles fully measured in the forward and transverse directions. The corresponding new electronic trigger, which selects events with momentum above a chosen threshold, is mixed or not to the forward trigger, in order to record correlated or inclusive data from the collisions p-p, p-anti-p, α-α. In the 90 0 spectrometer, we build drift chambers, set before the dipolar magnet. We studied the spatial resolution and the methods to associate tracks before and after this magnet. We developed the method to determine the momenta, by taking account of the variations of the deflecting power: the accuracy of this method is better than O.3%, and the global resolution is about 0.01 P 2 . We proposed also how to identify the particles from time of flight measurements and aerogel cerenkov counters [fr

  2. Vortex Ring Interaction With a Coaxially Aligned Cylinderical Rod

    Science.gov (United States)

    Arakeri, Jaywant H.; Rajmanoharan, P.; Koochesfahani, Manoochehr

    1998-11-01

    We present results of experiments of a fully developed vortex ring interacting with a cylinderical rod, having a rounded nose, placed coaxially in line with the motion of the ring. The pressure field of the translating ring causes unsteady boundary layer separation and results in the formation of one or more ( secondary ) vortex rings, that subsequently interact. The nature and strength of the interaction depends on the ratio of the cylinder diameter to the ring diameter. For the larger diameter cylinders the vortex ring travels a few ring diameters before it breaks up. For the smaller diameter cylinders the vortex ring speed decreases slowly and, simultaneously, its diameter increases.

  3. Propellers in Saturn's rings

    Science.gov (United States)

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

    2013-12-01

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

  4. Kayser-Fleischer Rings

    Science.gov (United States)

    ... Support Contacts Lab Tracker/Copper Calculator Stories Programs & Research ... About Everything you need to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring visible around the corneo- ...

  5. ASSOCIATIVE RINGS SOLVED AS LIE RINGS

    Directory of Open Access Journals (Sweden)

    M. B. Smirnov

    2011-01-01

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

  6. LINAC 3 experiment: This experiment is used to study some scenarios of the future LEIR (low-energy ion ring) vacuum design.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Photo 1 316LN stainless steel sheet 0.7 m thick sheet metal, with water-jet cut holes; before (sheet metal) and after rolling (tube). Photo 2 316LN stainless steel tube with water-jet cut holes. Photo 3 Inner tube is fitted with NEG (non-evaporable getter) strips, creating a kind of total NEG pump. Photo 4 Inner tube is fitted with NEG (non-evaporable getter) strips, creating a kind of total NEG pump. Photo 5 Same tubes but compiled on top of each other. Photo 6 The stack of tubes is put into a vacuum chamber that will be used in the LINAC 3 experiment during summer 2002 (lead-ion beam will be used for this experiment). The holes allow all-round pumping, i.e. close to the vacuum chamber walls.

  7. Annual tree rings in Piptadenia gonoacantha (Mart. J.F.Macbr. in a restoration experiment in the Atlantic Forest: potential for dendroecological research

    Directory of Open Access Journals (Sweden)

    Arno Fritz das Neves Brandes

    2016-01-01

    Full Text Available ABSTRACT The tree Piptadenia gonoachantha is widely used in forestry and in forest restoration projects, which require methods for evaluating tree growth. Long-term studies are necessary to determine patterns and detect changes in species growth rhythms. Tree ring analysis provides a precise method for determining age and documenting long-term growth trends in tropical tree species. The present study evaluated the periodicity of tree ring formation and radial growth dynamics of P. gonoachantha from a population of known age in the Poço das Antas Biological Reserve. Two radii from six trees were sampled using non-destructive methods. Tree rings were counted and measured to estimate age and to calculate diametric increment. All samples had 16 tree rings, which matched the known plantation age and confirmed the annual formation of rings. The individuals sampled had a mean annual diametric increment of 9.5 mm / year. Results showed a trend towards decreasing growth rate with increasing age. Individuals of P. gonoachantha in Ombrophilous Dense Forest produce annual tree rings, which holds potential for future dendroecological studies.

  8. Researches on the Piston Ring

    Science.gov (United States)

    Ehihara, Keikiti

    1944-01-01

    In internal combustion engines, steam engines, air compressors, and so forth, the piston ring plays an important role. Especially, the recent development of Diesel engines which require a high compression pressure for their working, makes, nowadays, the packing action of the piston ring far more important than ever. Though a number of papers have been published in regard to researches on the problem of the piston ring, none has yet dealt with an exact measurement of pressure exerted on the cylinder wall at any given point of the ring. The only paper that can be traced on this subject so far is Mr. Nakagawa's report on the determination of the relative distribution of pressure on the cylinder wall, but the measuring method adopted therein appears to need further consideration. No exact idea has yet been obtained as to how the obturation of gas between the piston and cylinder, the frictional resistance of the piston, and the wear of the cylinder wall are affected by the intensity and the distribution of the radial pressure of the piston ring. Consequently, the author has endeavored, by employing an apparatus of his own invention, to get an exact determination of the pressure distribution of the piston ring. By means of a newly devised ring tester, to which piezoelectricity of quartz was applied, the distribution of the radial pressure of many sample rings on the market was accurately determined. Since many famous piston rings show very irregular pressure distribution, the author investigated and achieved a manufacturing process of the piston ring which will exert uniform pressure on the cylinder wall. Temperature effects on the configuration and on the mean spring power have also been studied. Further, the tests were performed to ascertain how the gas tightness of the piston ring may be affected by the number or spring power. The researches as to the frictional resistance between the piston ring and the cylinder wall were carried out, too. The procedure of study, and

  9. Stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  10. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  11. Storage rings, internal targets and PEP

    International Nuclear Information System (INIS)

    Spencer, J.E.

    1986-11-01

    Storage rings with internal targets are described, using PEP as an example. The difference between electrons and heavier particles such as protons, antiprotons, and heavy ions is also discussed because it raises possibilities of bypass insertions for more exotic experiments. PEP is compared to other rings in various contexts to verify the assertion that it is an ideal ring for many fundamental and practical applications that can be carried on simultaneously

  12. Status of the SLC damping rings

    International Nuclear Information System (INIS)

    Hutton, A.M.; Davies-White, W.A.; Delahaye, J.P.

    1985-06-01

    Electron beams of full design energy 1.21 GeV and nearly full design intensity 4 x 10 10 particles/pulse (design 5 x 10 10 ) have been extracted from the Stanford Linac and successfully stored in the electron damping ring. Beams of less intensity have been extracted from the ring and reinjected into the Linac. The present intensity limits are not thought to be fundamental. The operating experience with the electron ring and the status of the construction of the positron ring will be discussed. 11 refs., 1 fig., 2 tabs

  13. SOR-ring failure

    International Nuclear Information System (INIS)

    Kitamura, Hideo

    1981-01-01

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

  14. Damping ring designs and issues

    International Nuclear Information System (INIS)

    Wolski, Andrzej; Decking, Winfried

    2003-01-01

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

  15. Minimally invasive mitral valve annuloplasty confers a long-term survival benefit compared with state-of-the-art treatment in heart failure with functional mitral regurgitation.

    Science.gov (United States)

    Penicka, Martin; Kotrc, Martin; Ondrus, Tomas; Mo, Yujing; Casselman, Filip; Vanderheyden, Marc; Van Camp, Guy; Van Praet, Frank; Bartunek, Jozef

    2017-10-01

    Clinical impact of the minimally invasive surgical mitral valve annuloplasty (MVA) of functional mitral regurgitation (FMR) in systolic heart failure on top of the state-of-the-art standards of care remains controversial. Therefore, we aimed to compare clinical outcomes of isolated MVA using the mini-invasive videothoracoscopic approach versus the state-of-the-art (CON=conservative) treatment in patients with chronic systolic heart failure and symptomatic FMR. The study population consisted of 379 patients (age 68.9±11.0years, 62.8% males) with left ventricular (LV) systolic dysfunction, symptomatic FMR and previous heart failure hospitalization. A total of 167 patients underwent undersized MVA and 212 patients were treated conservatively. A concomitant MAZE was performed in 53 (31.7%) patients. In the MVA group, the periprocedural and the 30-day mortality were 1.2% and 4.8%, respectively. During the median follow-up of 7.1years (IQR 3.5-9.8years) a total of 74 (44.3%) and 138 (65.1%) died in the MVA and the CON group, respectively (pstate-of-the-art treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Rings in drugs.

    Science.gov (United States)

    Taylor, Richard D; MacCoss, Malcolm; Lawson, Alastair D G

    2014-07-24

    We have analyzed the rings, ring systems, and frameworks in drugs listed in the FDA Orange Book to understand the frequency, timelines, molecular property space, and the application of these rings in different therapeutic areas and target classes. This analysis shows that there are only 351 ring systems and 1197 frameworks in drugs that came onto the market before 2013. Furthermore, on average six new ring systems enter drug space each year and approximately 28% of new drugs contain a new ring system. Moreover, it is very unusual for a drug to contain more than one new ring system and the majority of the most frequently used ring systems (83%) were first used in drugs developed prior to 1983. These observations give insight into the chemical novelty of drugs and potentially efficient ways to assess compound libraries and develop compounds from hit identification to lead optimization and beyond.

  17. Birth Control Ring

    Science.gov (United States)

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

  18. NRL ion ring program

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  19. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  20. Annular dynamics after mitral valve repair with different prosthetic rings: A real-time three-dimensional transesophageal echocardiography study.

    Science.gov (United States)

    Nishi, Hiroyuki; Toda, Koichi; Miyagawa, Shigeru; Yoshikawa, Yasushi; Fukushima, Satsuki; Kawamura, Masashi; Yoshioka, Daisuke; Saito, Tetsuya; Ueno, Takayoshi; Kuratani, Toru; Sawa, Yoshiki

    2016-09-01

    We assessed the effects of different types of prosthetic rings on mitral annular dynamics using real-time three-dimensional echocardiography (RT3DE). RT3DE was performed in 44 patients, including patients undergoing mitral annuloplasty using the Cosgrove-Edwards flexible band (Group A, n = 10), the semi-rigid Sorin Memo 3D ring (Group B, n = 17), the semi-rigid Edwards Physio II ring (Group C, n = 7) and ten control subjects. Various annular diameters were measured throughout the cardiac cycle. We observed flexible anterior annulus motion in all of the groups except Group C. A flexible posterior annulus was only observed in Group B and the Control group. The mitral annular area changed during the cardiac cycle by 8.4 ± 3.2, 6.3 ± 2.0, 3.2 ± 1.3, and 11.6 ± 5.0 % in Group A, Group B, Group C, and the Control group, respectively. The dynamic diastolic to systolic change in mitral annular diameters was lost in Group C, while it was maintained in Group A, and to a good degree in Group B. In comparison to the Control group, the mitral annulus shape was more ellipsoid in Group B and Group C, and more circular in Group A. Although mitral regurgitation was well controlled by all of the types of rings that were utilized in the present study, we demonstrated that the annulus motion and annulus shape differed according to the type of prosthetic ring that was used, which might provide important information for the selection of an appropriate prosthetic ring.

  1. Possibilities of climate reconstruction in the Holocene using δ13C and δ2H values from annual tree rings on the basis of climate chamber experiments and studies on present-day organisms

    International Nuclear Information System (INIS)

    Mayr, C.

    2002-01-01

    This study deals with the climatic information content of 2 H and 13 C levels in annual tree rings and plant material. The influence of variations in air temperature, relative humidity and water availability on stable isotope ratios in three different C 3 plant species (Brassica oleracea, Eucalyptus globulus, Vicia faba) was studied in climate chamber experiments. Furthermore, calibration studies using δ 13 C and δ 2 H time series from Southern German spruce (Picea abies) from two stands (Schussbach, Klosterreichenbach) were performed. Correlations with meteorological data from a nearby meteorological station prove stable isotope ratios to be dependent on weather conditions in the summer months (June through August). Using the δ 13 C ''response surfaces'' obtained from these experiments as well as correlations from long gridbox precipitation series it was shown that for the climate mode under study the δ 13 C values largely reflect water availability to trees, which is greatly influenced by summer precipitation, especially at the more arid of the two sites. The results of the climate chamber experiments also suggest that the spruce δ 2 H values largely reflect the isotope variation in soil water and hence the δ 2 H fluctuations in summer precipitation. The study closes with a discussion of methodological approaches to creating long isotope series from annual tree rings of subfossil oak trees

  2. Complete snake and rotator schemes for spin polarization in proton rings and large electron rings

    International Nuclear Information System (INIS)

    Steffen, K.

    1983-11-01

    In order to maintain spin polarization in proton rings and large electron rings, some generalized Siberian Snake scheme may be required to make the spin tune almost independent of energy and thus avoid depolarizing resonances. The practical problem of finding such schemes that, at reasonable technical effort, can be made to work over large energy ranges has been addressed before and is here revisited in a broadened view and with added new suggestions. As a result, possibly optimum schemes for electron rings (LEP) and proton rings are described. In the proposed LEP scheme, spin rotation is devised such that, at the interaction points, the spin direction is longitudinal as required for experiments. (orig.)

  3. Clinical Efficacy and Its Prognostic Factor of Percutaneous Endoscopic Lumbar Annuloplasty and Nucleoplasty for the Treatment of Patients with Discogenic Low Back Pain.

    Science.gov (United States)

    Lee, Jung Hwan; Lee, Sang-Ho

    2017-09-01

    The choice of appropriate treatment of discogenic low back pain (DLBP) frequently is difficult. This study sought to identify the clinical efficacy of percutaneous endoscopic lumbar annuloplasty and nucleoplasty (PELAN) to treat patients with DLBP and to investigate prognostic clinical or radiologic variables. Eighty-nine patients with a diagnosis of DLBP who underwent PELAN were included. Numeric Rating Scale (NRS) for back pain, Oswestry Disability Index % (ODI%), and modified Macnab criteria were measured at short-term (3-4 weeks) and long-term follow-up period (at least 12 months) to investigate clinical efficacy of PELAN. The subjects were defined as successful group in case of 50% or more reduction of NRS, 40% or more reduction of ODI%, and good or excellent response of Macnab criteria. Clinical and radiologic variables were compared between successful and unsuccessful outcomes group to determine prognostic variables. NRS and ODI% were significantly reduced at short- and long-term follow-up after PELAN. Sixty-two (69.7%) and 68 (76.4%) obtained successful NRS reduction and 59 (66.3%) and 68 (76.4%) accomplished successful ODI% reduction at short-term and long-term follow-up, respectively. Successful Mcnab response was found in 61% at short term and 65.2% at long term. Pain during waist flexion among clinical variables was significantly related to good clinical outcomes and Modic change among radiologic variables was significantly related to poor clinical outcomes. PELAN provided favorable outcomes in patients with DLBP who were refractory to conservative treatments. Flexion pain was good prognostic, and Modic change was a poor prognostic variable. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Token Ring Project

    Directory of Open Access Journals (Sweden)

    Adela Ionescu

    2007-01-01

    Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

  5. Token ring technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This report provides an overview of the IBM Token-Ring technology and products built by IBM and compatible vendors. It consists of two sections: 1. A summary of the design trade-offs for the IBM Token-Ring. 2. A summary of the products of the major token-ring compatible vendors broken down by adapters and components, wiring systems, testing, and new chip technology.

  6. Radioactive gold ring dermatitis

    International Nuclear Information System (INIS)

    Miller, R.A.; Aldrich, J.E.

    1990-01-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy

  7. Physics of quantum rings

    International Nuclear Information System (INIS)

    Fomin, Vladimir M.

    2014-01-01

    Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

  8. EGFR immunohistochemistry as biomarker for antibody-based therapy of squamous NSCLC - Experience from the first ring trial of the German Quality Assurance Initiative for Pathology (QuIP®).

    Science.gov (United States)

    Petersen, Iver; Dietel, Manfred; Geilenkeuser, Wolf J; Mireskandari, Masoud; Weichert, Wilko; Steiger, Katja; Scheel, Andreas H; Büttner, Reinhard; Schirmacher, Peter; Warth, Arne; Lasitschka, Felix; Schildhaus, Hans-Ulrich; Kirchner, Thomas; Reu, Simone; Kreipe, Hans; Länger, Florian; Tiemann, Markus; Schulte, Christoph; Jöhrens, Korinna

    2017-12-01

    EGFR and its downstream signaling pathway are important targets for cancer therapy. Recently, the monoclonal anti-EGFR antibody Necitumumab in combination with gemcitabine and cisplatin was approved (EMA/14106/2016) for first-line treatment of squamous non-small cell carcinoma (SqNSCLC). Eligibility was restricted to cases with positive EGFR expression. In this context, a ring trial of the Quality Assurance Initiative for Pathology (QuIP ® ) was launched to prepare the German pathology community for a reliable and reproducible, immunohistochemically based biomarker test. The trial was set up by a three-step approach. Two lead institutes were nominated to organize the trial process and to select appropriate cancer samples. These were first tested by the H-score (range 0-300) to identify positive and negative cases. Seven additional pathology institutes with experience in EGFR immunohistochemistry each tested the selected panel of identical cases (internal ring trial) to confirm the suitability of samples and scoring criteria. Then the open ring trial for all institutes of pathology in German speaking countries was announced. For the internal trial 8 EGFR-positive and 2 negative lung sqNSCLC samples were selected. A cut-off value of cell membranous staining in≥1% of tumor cells was introduced to define a case as EGFR negative or positive. Two points were attainable per correctly assessed sample leading to a maximum of 20 points,≥18 points were required for a successful participation. All 7 panel institute passed this barrier, 5 with the maximum of 20 points and two with one error (18 points) being related to one case with incorrect interpretation of cytoplasmic versus membranous staining and one case with an H-score of 2 as being considered EGFR positive. A second cut-off value (H-score≥3) was therefore introduced. In the open ring trial, 34 institutions participated of which 28 were successful according to the above criteria. The trial revealed a high

  9. Injection envelope matching in storage rings

    International Nuclear Information System (INIS)

    Minty, M.G.; Spence, W.L.

    1995-05-01

    The shape and size of the transverse phase space injected into a storage ring can be deduced from turn-by-turn measurements of the transient behavior of the beam envelope in the ring. Envelope oscillations at 2 x the β-tron frequency indicate the presence of a β-mismatch, while envelope oscillations at the β-tron frequency are the signature of a dispersion function mismatch. Experiments in injection optimization using synchrotron radiation imaging of the beam and a fast-gated camera at the SLC damping rings are reported

  10. EBT ring physics

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers

  11. Transplante cardíaco com anastomose bicaval e anuloplastia tricúspide profilática no enxerto Cardiac transplantation with bicaval anastomosis and prophylactic graft tricuspid annuloplasty

    Directory of Open Access Journals (Sweden)

    Alfredo Inácio Fiorelli

    2008-03-01

    Full Text Available OBJETIVO: O presente estudo tem por objetivo avaliar os efeitos da anuloplastia tricúspide profilática no coração doador em transplante cardíaco com anastomose bicaval. MÉTODOS: De 2002 a 2005, foram selecionados de forma não aleatória 20 pacientes submetidos ao transplante cardíaco pela técnica bicaval e com sobrevida superior a seis meses. Eles foram divididos em dois grupos: Grupo I - 10 pacientes que receberam coração doador com anuloplastia tricúspide profilática, pela técnica de De Vega; e Grupo II - 10 pacientes que não receberam a anuloplastia, ambos com características semelhantes. O grau de regurgitação tricúspide foi avaliado pela ecocardiografia transtorácica com Doppler e foi quantificado entre 0 e 3 (0=ausente, 1=discreto, 2=moderado, 3=grave. O desempenho miocárdico foi avaliado pela fração de ejeção ventricular e pelo estudo hemodinâmico invasivo, durante as biópsias endomiocárdicas de rotina. RESULTADOS: O período médio de observação foi de 14,6±4,3 meses (6 e 16 meses. Houve apenas um óbito no grupo II não relacionado à anuloplastia. O grau médio de regurgitação tricúspide no Grupo I foi de 0,4±0,6 e no Grupo II foi de 1,6±0,8 (p OBJECTIVE: This study aims to evaluate the effects of prophylactic heart donor tricuspid annuloplasty in patients after heart transplantation with bicaval anastomosis. METHODS: From 2002 to 2005, 20 patients undergoing heart transplantation with bicaval anastomosis and with a survival rate over 6 months were deliberately selected. Patients were divided into two groups: Group I - 10 patients who underwent prophylactic heart donor tricuspid annuloplasty by the De Vega technique; and Group II - 10 patients did not undergo annuloplasty. In both groups, presurgical clinical characteristics were the same. The tricuspid regurgitation degree was evaluated by transthoracic Doppler echocardiography and it was qualified from 0 to 3 (0=absent, 1=mild, 2=moderated, 3

  12. Requirements on internal targets for the Aladdin storage ring

    International Nuclear Information System (INIS)

    Holt, R.J.

    1984-01-01

    The feasibility of performing electron scattering experiments with polarized targets in electron storage rings is explored by considering an electron-deuteron scattering experiment at the Aladdin storage ring. It is noted that this new method is compatible with recent proposals for linac-stretcher-ring accelerator designs. A new method for producing a polarized hydrogen or deuterium target is proposed and some preliminary results are described. 21 references, 6 figures, 1 table

  13. Is the bell ringing?

    CERN Multimedia

    Francesco Poppi

    2010-01-01

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

  14. On the Laurent polynomial rings

    International Nuclear Information System (INIS)

    Stefanescu, D.

    1985-02-01

    We describe some properties of the Laurent polynomial rings in a finite number of indeterminates over a commutative unitary ring. We study some subrings of the Laurent polynomial rings. We finally obtain two cancellation properties. (author)

  15. Cavity Ring-Down Measurement of Aerosol Optical Properties During the Asian Dust Above Monterey Experiment and DOE Aerosol Intensive Operating Period

    Science.gov (United States)

    Ricci, K.; Strawa, A. W.; Provencal, R.; Castaneda, R.; Bucholtz, A.; Schmid, B.

    2004-01-01

    Large uncertainties in the effects of aerosols on climate require improved in-situ measurements of extinction coefficient and single-scattering albedo. This paper describes preliminary results from Cadenza, a new continuous wave cavity ring-down (CW-CRD) instrument designed to address these uncertainties. Cadenza measures the aerosol extinction coefficient for 675 nm and 1550 nm light, and simultaneously measures the scattering coefficient at 675 nm. In the past year Cadenza was deployed in the Asian Dust Above Monterey (ADAM) and DOE Aerosol Intensive Operating Period (IOP) field projects. During these flights Cadenza produced measurements of aerosol extinction in the range from 0.2 to 300/Mm with an estimated precision of 0.1/Mm for 1550 nm light and 0.2/Mm for 675 nm light. Cadenza data from the ADAM and Aerosol IOP missions compared favorably with data from the other instruments aboard the CIRPAS Twin Otter aircraft and participating in those projects. We present comparisons between the Cadenza measurements and those from a TSI nephelometer, Particle Soot Absorption Photometer (PSAP), and the AATS 14 sun-photometer. Measurements of the optical properties of smoke and dust plumes sampled during these campaigns are presented and estimates of heating rates due to these plumes are made.

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-03-11

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

  18. Faithfully quadratic rings

    CERN Document Server

    Dickmann, M

    2015-01-01

    In this monograph the authors extend the classical algebraic theory of quadratic forms over fields to diagonal quadratic forms with invertible entries over broad classes of commutative, unitary rings where -1 is not a sum of squares and 2 is invertible. They accomplish this by: (1) Extending the classical notion of matrix isometry of forms to a suitable notion of T-isometry, where T is a preorder of the given ring, A, or T = A^2. (2) Introducing in this context three axioms expressing simple properties of (value) representation of elements of the ring by quadratic forms, well-known to hold in

  19. The "g-2" Muon Storage Ring

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The "g-2" muon storage ring, shortly before completion in June 1974. Bursts of pions (from a target, hit by a proton beam from the 26 GeV PS) are injected and polarized muons from their decay are captured on a stable orbit. When the muons decay too, their precession in the magnetic field of the storage ring causes a modulation of the decay-electron counting rate, from which the muon's anomalous magnetic moment can be determined. In 1977, the "g-2" magnets were modified to build ICE (Initial Cooling Experiment), a proton and antiproton storage ring for testing stochastic and electron cooling. Later on, the magnets had a 3rd life, when the ion storage ring CELSIUS was built from them in Uppsala. For later use as ICE, see 7711282, 7802099, 7809081,7908242.

  20. On arbitrarily graded rings

    Indian Academy of Sciences (India)

    58

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

  1. The g-2 ring

    CERN Multimedia

    1974-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-11

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

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  4. [Liesegang's rings resembling helminthiasis].

    Science.gov (United States)

    Zámecník, M; Riedl, I

    1996-12-01

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

  5. Storage ring group summary

    International Nuclear Information System (INIS)

    King, N.M.

    1980-01-01

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

  6. The rings of Uranus

    Science.gov (United States)

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

    1977-01-01

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

  7. Saturn's Ring: Pre-Cassini Status and Mission Goals

    Science.gov (United States)

    Cuzzi, Jeff N.; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    In November 1980, and again in August 1981, identical Voyager spacecraft flew through the Saturn system, changing forever the way we think about planetary rings. Although Saturn's rings had been the only known ring system for three centuries, a ring system around Uranus had been discovered by stellar occultations from Earth in 1977, and the nearly transparent ring of Jupiter was imaged by Voyager in 1979 (the presence of material there had been inferred from charged particle experiments on Pioneer 10 and 11 several years earlier). While Saturn had thus temporarily lost its uniqueness as having the only ring system, with Voyager it handily recaptured the role of having the most fascinating one. The Voyager breakthroughs included spiral density and bending waves such as cause galactic structure; ubiquitous fine-scale radial 'irregular' structure, with the appearance of record-grooves; regional and local variations in particle color; complex, azimuthally variable ring structure; empty gaps in the rings, some containing very regular, sharp-edged, elliptical rings and one containing both a small moonlet and incomplete arcs of dusty material; and shadowy 'spokes' that flicker across the main rings. One of the paradigm shifts of this period was the realization that many aspects of planetary rings, and even the ring systems themselves, could be 'recent' on geological timescales. These early results are reviewed and summarized in the Arizona Space Science series volumes 'Saturn'. (An excellent review of ring dynamics at a formative stage is by Goldreich and Tremaine.) From the mid 1980's to the time of this writing, progress has been steady, while at a less heady pace, and some of the novel ring properties revealed by Voyager 1 and 2 are beginning to be better understood. It is clearly impossible to cite, much less review, every advance over the last decade; however, below we summarize the main advances in understanding of Saturn's rings since the mid 1980's, in the context

  8. Some Aspects of Ring Theory

    CERN Document Server

    Herstein, IN

    2011-01-01

    S. Amitsur: Associative rings with identities.- I.N. Herstein: Topics in ring theory.- N. Jacobson: Representation theory of Jordan algebras.- I. Kaplansky: The theory of homological dimension.- D. Buchsbaum: Complexes in local ring theory.- P.H. Cohn: Two topics in ring theory.- A.W. Goldie: Non-commutative localisation.

  9. Ring correlations in random networks.

    Science.gov (United States)

    Sadjadi, Mahdi; Thorpe, M F

    2016-12-01

    We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.

  10. PREFACE: Special section on vortex rings Special section on vortex rings

    Science.gov (United States)

    Fukumoto, Yasuhide

    2009-10-01

    This special section of Fluid Dynamics Research includes five articles on vortex rings in both classical and quantum fluids. The leading scientists of the field describe the trends in and the state-of-the-art development of experiments, theories and numerical simulations of vortex rings. The year 2008 was the 150th anniversary of 'vortex motion' since Hermann von Helmholtz opened up this field. In 1858, Helmholtz published a paper in Crelle's Journal which put forward the concept of 'vorticity' and made the first analysis of vortex motion. Fluid mechanics before that was limited to irrotational motion. In the absence of vorticity, the motion of an incompressible homogeneous fluid is virtually equivalent to a rigid-body motion in the sense that the fluid motion is determined once the boundary configuration is specified. Helmholtz proved, among other things, that, without viscosity, a vortex line is frozen into the fluid. This Helmholtz's law immediately implies the preservation of knots and links of vortex lines and its implication is enormous. One of the major trends of fluid mechanics since the latter half of the 20th century is to clarify the topological meaning of Helmholtz's law and to exploit it to develop theoretical and numerical methods to find the solutions of the Euler equations and to develop experimental techniques to gain an insight into fluid motion. Vortex rings are prominent coherent structures in a variety of fluid motions from the microscopic scale, through human and mesoscale to astrophysical scales, and have attracted people's interest. The late professor Philip G Saffman (1981) emphasized the significance of studies on vortex rings. One particular motion exemplifies the whole range of problems of vortex motion and is also a commonly known phenomenon, namely the vortex ring or smoke ring. Vortex rings are easily produced by dropping drops of one liquid into another, or by puffing fluid out of a hole, or by exhaling smoke if one has the skill

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

    Science.gov (United States)

    Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.

    2010-10-01

    Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  12. Commissioning of the diamond light source storage ring vacuum system

    International Nuclear Information System (INIS)

    Cox, M P; Boussier, B; Bryan, S; Macdonald, B F; Shiers, H S

    2008-01-01

    The Diamond storage ring has been operating with a 3 GeV electron beam since September 2006 and 190 A.h of beam dose have been accumulated. The pressure in the storage ring is 4.2 10 -10 mbar without beam, rising to 7.9 10 -10 mbar with 125 mA of stored beam. Data on the storage ring vacuum performance and experience from commissioning and beam conditioning are presented

  13. The Rings of Saturn

    Science.gov (United States)

    Cuzzi, J. N.; Filacchione, G.; Marouf, E. A.

    2018-03-01

    One could become an expert on Saturn's iconic rings pretty easily in the early 1970s, as very little was known about them beyond the distinction between the A, B, and C rings, and the Cassini Division or "gap" between rings A and B (Alexander, 1962; Bobrov, 1970). Water ice was discovered spectroscopically on the ring particle surfaces, and radar and microwave emission observations proved that the particles must be centimeters to meters in size, consisting primarily, not just superficially, of water ice (Pollack, 1975). While a 2:1 orbital resonance with Mimas had long been suspected of having something to do with the Cassini Division, computers of the time were unable to model the subtle dynamical effects that we now know to dominate ring structure. This innocent state of affairs was exploded by the Voyager 1 and 2 encounters in 1980 and 1981. Spectacular images revealed filigree structure and odd regional color variations, and exquisitely detailed radial profiles of fluctuating particle abundance were obtained from the first stellar and radio occultations, having resolution almost at the scale of single particles. Voyager-era understanding was reviewed by Cuzzi et al. (1984) and Esposito et al. (1984). While the Voyager data kept ring scientists busy for decades, planning which led to the monumentally successful NASA-ESA-ASI Cassini mission, which arrived in 2004, had been under way even before Voyager got to Saturn. A review of pre-Cassini knowledge of Saturn's Rings can be found in Orton et al. (2009). This chapter will build on recent topical and process-specific reviews that treat the gamut of ring phenomena and its underlying physics in considerable detail (Colwell et al., 2009; Cuzzi et al., 2009; Horányi et al., 2009; Schmidt et al., 2009; Esposito, 2010; Tiscareno, 2013b; Esposito, 2014). We will follow and extend the general organization of Cuzzi et al. (2010), the most recent general discussion of Saturn's rings. For brevity and the benefit of the

  14. Ion-ion collisions and ion storage rings

    International Nuclear Information System (INIS)

    Mowat, J.R.

    1988-01-01

    Improved understanding of fundamental ion-ion interactions is expected to emerge from research carried out with ion storage rings. In this short survey the significant advantages and unique features that make stored ions useful targets for collision experiments are reviewed and discussed. It is pointed out that improvements to existing ion-ion experiments, as well as qualitatively new experiments, should occur over the next few years as ion storage rings become available for atomic physics. Some new experiments are suggested which are difficult if not impossible with present-day technology, but which seem feasible at storage rings facilities. (orig.)

  15. BERKELEY: ALS ring

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-06-15

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  16. Compressible Vortex Ring

    Science.gov (United States)

    Elavarasan, Ramasamy; Arakeri, Jayawant; Krothapalli, Anjaneyulu

    1999-11-01

    The interaction of a high-speed vortex ring with a shock wave is one of the fundamental issues as it is a source of sound in supersonic jets. The complex flow field induced by the vortex alters the propagation of the shock wave greatly. In order to understand the process, a compressible vortex ring is studied in detail using Particle Image Velocimetry (PIV) and shadowgraphic techniques. The high-speed vortex ring is generated from a shock tube and the shock wave, which precedes the vortex, is reflected back by a plate and made to interact with the vortex. The shadowgraph images indicate that the reflected shock front is influenced by the non-uniform flow induced by the vortex and is decelerated while passing through the vortex. It appears that after the interaction the shock is "split" into two. The PIV measurements provided clear picture about the evolution of the vortex at different time interval. The centerline velocity traces show the maximum velocity to be around 350 m/s. The velocity field, unlike in incompressible rings, contains contributions from both the shock and the vortex ring. The velocity distribution across the vortex core, core diameter and circulation are also calculated from the PIV data.

  17. BERKELEY: ALS ring

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  18. Almost ring theory

    CERN Document Server

    2003-01-01

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

  19. Stable CSR in storage rings: A model

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  20. Stable CSR in Storage Rings: A Model

    International Nuclear Information System (INIS)

    Sannibale, F.

    2005-01-01

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

  1. Compact electron storage rings

    International Nuclear Information System (INIS)

    Williams, G.P.

    1987-01-01

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

  2. The covariant chiral ring

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-23

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

  3. Vortex and source rings

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre

    2017-01-01

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

  4. The Saturnian rings

    International Nuclear Information System (INIS)

    Alfven, H.

    1975-09-01

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

  5. RINGED ACCRETION DISKS: INSTABILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2016-04-01

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

  6. Experiences with the operation of a shaft-helix in connection with a special steel ring lining in the shafts Gorleben 1 and 2

    International Nuclear Information System (INIS)

    Tonscheidt, H.W.; Kahl, J.

    1991-01-01

    When sinking the Gorleben 1 shaft good reasons prevented the method of drilling and blasting to create the excavation. Considering the special conditions and after a successful test, the application of a modified helix was given preference to an impact-ripper, tested on an other freeze shaft project. A report is given on the experiences gained with respect to the following criteria: Assembly, dismantling and transport of the machine in the shaft - conveyance of electric energy - dust problems when cutting the concrete plug and the means engaged to overcome those problems - performance in the different types of rock formation - cutting the circular shape of the excavation with sufficient accuracy - matters of safety in connection with cutting, loading and lining the excavation - consumption and costs of cutters - total costs. A final assessment of the excavation system is made with respect to its possible application with for shaft-sinking projects. (orig.) [de

  7. First observation of Cherenkov ring images using hybrid photon detectors

    International Nuclear Information System (INIS)

    Albrecht, E.; Wilkinson, G.; Bibby, J.H.; Giles, R.; Harnew, N.; Smale, N.; Brook, N.H.; Halley, A.W.; O'Shea, V.; French, M.; Gibson, V.; Wotton, S.A.; Schomaker, R.

    1998-01-01

    A ring-imaging Cherenkov detector, equipped with hybrid photon detectors, has been operated in a charged-particle beam. Focussed ring images from various particle types were detected using silica aerogel, air and C 4 F 10 gas radiators. The detector, a prototype for the CERN LHC-B experiment, is described and first observations are reported. (orig.)

  8. First observation of Cherenkov ring images using hybrid photon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, E.; Wilkinson, G. [European Organization for Nuclear Research, Geneva (Switzerland). Div. Particle Physics Experiments; Barber, G.; Duane, A.; John, M.; Miller, D.G.; Websdale, D. [Imperial College of Science Technology and Medicine, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Bibby, J.H.; Giles, R.; Harnew, N.; Smale, N. [University of Oxford, Department of Nuclear Physics, Keble Road, Oxford OX1 3RH (United Kingdom); Brook, N.H.; Halley, A.W.; O`Shea, V. [University of Glasgow, Department of Physics, Glasgow G12 8QQ (United Kingdom); French, M. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Gibson, V.; Wotton, S.A. [University of Cambridge, Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE (United Kingdom); Schomaker, R. [Delft Electronic Products BV, 9300 AB Roden (Netherlands)

    1998-07-11

    A ring-imaging Cherenkov detector, equipped with hybrid photon detectors, has been operated in a charged-particle beam. Focussed ring images from various particle types were detected using silica aerogel, air and C{sub 4}F{sub 10} gas radiators. The detector, a prototype for the CERN LHC-B experiment, is described and first observations are reported. (orig.)

  9. Storage ring at HIE-ISOLDE Technical design report

    NARCIS (Netherlands)

    Grieser, M.; Litvinov, Yu. A.; Raabe, R.; Blaum, K.; Blumenfeld, Y.; Butler, P. A.; Wenander, F.; Woods, P. J.; Aliotta, M.; Andreyev, A.; Artemyev, A.; Atanasov, D.; Aumann, T.; Balabanski, D.; Barzakh, A.; Batist, L.; Bernardes, A. -P.; Bernhardt, D.; Billowes, J.; Bishop, S.; Borge, M.; Borzov, I.; Boston, A. J.; Brandau, C.; Catford, W.; Catherall, R.; Cederkall, J.; Cullen, D.; Davinson, T.; Dillmann, I.; Dimopoulou, C.; Dracoulis, G.; Duellmann, Ch. E.; Egelhof, P.; Estrade, A.; Fischer, D.; Flanagan, K.; Fraile, L.; Fraser, M. A.; Freeman, S. J.; Geissel, H.; Gerl, J.; Greenlees, P.; Grisenti, R. E.; Habs, D.; von Hahn, R.; Hagmann, S.; Hausmann, M.; He, J. J.; Heil, M.; Huyse, M.; Jenkins, D.; Jokinen, A.; Jonson, B.; Joss, D. T.; Kadi, Y.; Kalantar-Nayestanaki, N.; Kay, B. P.; Kiselev, O.; Kluge, H. -J.; Kowalska, M.; Kozhuharov, C.; Kreim, S.; Kroell, T.; Kurcewicz, J.; Labiche, M.; Lemmon, R. C.; Lestinsky, M.; Lotay, G.; Ma, X. W.; Marta, M.; Meng, J.; Muecher, D.; Mukha, I.; Mueller, A.; Murphy, A. St J.; Neyens, G.; Nilsson, T.; Nociforo, C.; Noertershaeuser, W.; Page, R. D.; Pasini, M.; Petridis, N.; Pietralla, N.; Pfuetzner, M.; Podolyak, Z.; Regan, P.; Reed, M. W.; Reifarth, R.; Reiter, P.; Repnow, R.; Riisager, K.; Rubio, B.; Sanjari, M. S.; Savin, D. W.; Scheidenberger, C.; Schippers, S.; Schneider, D.; Schuch, R.; Schwalm, D.; Schweikhard, L.; Shubina, D.; Siesling, E.; Simon, H.; Simpson, J.; Smith, J.; Sonnabend, K.; Steck, M.; Stora, T.; Stoehlker, T.; Sun, B.; Surzhykov, A.; Suzaki, F.; Tarasov, O.; Trotsenko, S.; Tu, X. L.; Van Duppen, P.; Volpe, C.; Voulot, D.; Walker, P. M.; Wildner, E.; Winckler, N.; Winters, D. F. A.; Wolf, A.; Xu, H. S.; Yakushev, A.; Yamaguchi, T.; Yuan, Y. J.; Zhang, Y. H.; Zuber, K.; Bosch, F.M.

    We propose to install a storage ring at an ISOL-type radioactive beam facility for the first time. Specifically, we intend to setup the heavy-ion, low-energy ring TSR at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored secondary beams

  10. On the evolution of vortex rings with swirl

    International Nuclear Information System (INIS)

    Naitoh, Takashi; Okura, Nobuyuki; Gotoh, Toshiyuki; Kato, Yusuke

    2014-01-01

    A laminar vortex ring with swirl, which has the meridional velocity component inside the vortex core, was experimentally generated by the brief fluid ejection from a rotating outlet. The evolution of the vortex ring was investigated with flow visualizations and particle image velocimetry measurements in order to find the influence of swirling flow in particular upon the transition to turbulence. Immediately after the formation of a vortex ring with swirl, a columnar strong vortex along the symmetric axis is observed in all cases of the present experiment. Then the characteristic fluid discharging from a vortex ring with swirl referred to as “peeling off” appears. The amount of discharging fluid due to the “peeling off” increases with the angular velocity of the rotating outlet. We conjectured that the mechanism generating the “peeling off” is related to the columnar strong vortex by close observations of the spatio-temporal development of the vorticity distribution and the cutting 3D images constructed from the successive cross sections of a vortex ring. While a laminar vortex ring without swirl may develop azimuthal waves around its circumference at some later time and the ring structure subsequently breaks, the swirling flow in a vortex ring core reduces the amplification rate of the azimuthal wavy deformation and preserved its ring structure. Then the traveling distance of a vortex ring can be extended using the swirl flow under certain conditions

  11. On the evolution of vortex rings with swirl

    Energy Technology Data Exchange (ETDEWEB)

    Naitoh, Takashi, E-mail: naitoh.takashi@nitech.ac.jp [Department of Engineering Physics, Electronics and Mechanics, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Okura, Nobuyuki, E-mail: ohkura@meijo-u.ac.jp [Department of Vehicle and Mechanical Engineering, Meijo University, 1-501 Shiogamaguchi Tempaku-ku, Nagoya 468-8502 (Japan); Gotoh, Toshiyuki, E-mail: gotoh.toshiyuki@nitech.ac.jp [Department of Scientific and Engineering Simulation, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kato, Yusuke [Controller Business Unit Engineering Division 1, Engineering Department 3, Denso Wave Incorporated, 1 Yoshiike Kusagi Agui-cho, Chita-gun Aichi 470-2297 (Japan)

    2014-06-15

    A laminar vortex ring with swirl, which has the meridional velocity component inside the vortex core, was experimentally generated by the brief fluid ejection from a rotating outlet. The evolution of the vortex ring was investigated with flow visualizations and particle image velocimetry measurements in order to find the influence of swirling flow in particular upon the transition to turbulence. Immediately after the formation of a vortex ring with swirl, a columnar strong vortex along the symmetric axis is observed in all cases of the present experiment. Then the characteristic fluid discharging from a vortex ring with swirl referred to as “peeling off” appears. The amount of discharging fluid due to the “peeling off” increases with the angular velocity of the rotating outlet. We conjectured that the mechanism generating the “peeling off” is related to the columnar strong vortex by close observations of the spatio-temporal development of the vorticity distribution and the cutting 3D images constructed from the successive cross sections of a vortex ring. While a laminar vortex ring without swirl may develop azimuthal waves around its circumference at some later time and the ring structure subsequently breaks, the swirling flow in a vortex ring core reduces the amplification rate of the azimuthal wavy deformation and preserved its ring structure. Then the traveling distance of a vortex ring can be extended using the swirl flow under certain conditions.

  12. Fusion rings and fusion ideals

    DEFF Research Database (Denmark)

    Andersen, Troels Bak

    by the so-called fusion ideals. The fusion rings of Wess-Zumino-Witten models have been widely studied and are well understood in terms of precise combinatorial descriptions and explicit generating sets of the fusion ideals. They also appear in another, more general, setting via tilting modules for quantum......This dissertation investigates fusion rings, which are Grothendieck groups of rigid, monoidal, semisimple, abelian categories. Special interest is in rational fusion rings, i.e., fusion rings which admit a finite basis, for as commutative rings they may be presented as quotients of polynomial rings...

  13. Flushing Ring for EDM

    Science.gov (United States)

    Earwood, L.

    1985-01-01

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

  14. Sector ring accelerator ''RESATRON''

    International Nuclear Information System (INIS)

    Schwabe, E.

    1980-01-01

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

  15. Ring chromosome 13

    DEFF Research Database (Denmark)

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

    1992-01-01

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

  16. SXLS storage ring design

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

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

  17. Ring magnetron ionizer

    International Nuclear Information System (INIS)

    Alessi, J.G.

    1986-01-01

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

  18. Algebras, rings and modules

    CERN Document Server

    Hazewinkel, Michiel; Kirichenko, V V

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

  19. Lattices for antiproton rings

    International Nuclear Information System (INIS)

    Autin, B.

    1984-01-01

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

  20. Estimates of CSR Instability Thresholds for Various Storage Rings

    CERN Document Server

    Zimmermann, Frank

    2010-01-01

    We review the key predictions and conditions by several authors for the onset of longitudinal instabilities due to coherent synchrotron radiation (CSR), and evaluate them numerically for various storage rings, namely the KEKB High Energy Ring (HER) & Low Energy Ring (LER), SuperKEKB HER & LER, old and new designs of the SuperKEKB Damping Ring (DR), SuperB HER & LER, CLIC DR (2009 and 2010 design parameters), SLC DR, and ATF DR. We show that the theoretical uncertainty in the instability onset is at least at the level of 20-30% in bunch intensity. More importantly, we present some doubts about the general applicability for many of these storage rings of some commonly used formulae. To cast further light on these questions, an experiment at lower beam energy on the ATF Damping Ring is proposed.

  1. Seco-B-Ring Steroidal Dienynes with Aromatic D Ring: Design, Synthesis and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Marcin Szybinski

    2017-10-01

    Full Text Available Continuing our structure-activity studies on the vitamin D analogs with the altered intercyclic seco-B-ring fragment, we designed compounds possessing dienyne system conjugated with the benzene D ring. Analysis of the literature data and the docking experiments seemed to indicate that the target compounds could mimic the ligands with a good affinity to the vitamin D receptor (VDR. Multi-step synthesis of the C/D-ring building block of the tetralone structure was achieved and its enol triflate was coupled with the known A-ring fragments, possessing conjugated enyne moiety, using Sonogashira protocol. The structures of the final products were confirmed by NMR, UV and mass spectroscopy. Their binding affinities for the full-length human VDR were determined and it was established that compound substituted at C-2 with exomethylene group showed significant binding to the receptor. This analog was also able to induce monocytic differentiation of HL-60 cells.

  2. Interaction Region Design for a Ring-Ring LHeC

    CERN Document Server

    Thompson, L N S; Bernard, N R; Fitterer, M; Holzer, B; Klein, M; Kostka, P

    2011-01-01

    tively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discusse...

  3. FUZZY RINGS AND ITS PROPERTIES

    Directory of Open Access Journals (Sweden)

    Karyati Karyati

    2017-01-01

      One of algebraic structure that involves a binary operation is a group that is defined  an un empty set (classical with an associative binary operation, it has identity elements and each element has an inverse. In the structure of the group known as the term subgroup, normal subgroup, subgroup and factor group homomorphism and its properties. Classical algebraic structure is developed to algebraic structure fuzzy by the researchers as an example semi group fuzzy and fuzzy group after fuzzy sets is introduced by L. A. Zadeh at 1965. It is inspired of writing about semi group fuzzy and group of fuzzy, a research on the algebraic structure of the ring is held with reviewing ring fuzzy, ideal ring fuzzy, homomorphism ring fuzzy and quotient ring fuzzy with its properties. The results of this study are obtained fuzzy properties of the ring, ring ideal properties fuzzy, properties of fuzzy ring homomorphism and properties of fuzzy quotient ring by utilizing a subset of a subset level  and strong level  as well as image and pre-image homomorphism fuzzy ring.   Keywords: fuzzy ring, subset level, homomorphism fuzzy ring, fuzzy quotient ring

  4. Bunch coalescing in the Fermilab Main Ring

    International Nuclear Information System (INIS)

    Wildman, D.; Martin, P.; Meisner, K.; Miller, H.W.

    1987-01-01

    A new RF system has been installed in the Fermilab Main Ring to coalesce up to 13 individual bunches of protons or antiprotons into a single high-intensity bunch. The coalescing process consists of adiabatically reducing the h=1113 Main Ring RF voltage from 1 MV to less than 1 kV, capturing the debunched beam in a linearized h=53 and h=106 bucket, rotating for a quarter of a synchrotron oscillation period, and then recapturing the beam in a single h=1113 bucket. The new system is described and the results of recent coalescing experiments are compared with computer-generated particle tracking simulations

  5. On the propagation and decay of North Brazil Current rings

    Science.gov (United States)

    Jochumsen, Kerstin; Rhein, Monika; Hüttl-Kabus, Sabine; BöNing, Claus W.

    2010-10-01

    Near the western boundary of the tropical North Atlantic, where the North Brazil Current (NBC) retroflects into the North Equatorial Countercurrent, large anticyclonic rings are shed. After separating from the retroflection region, the so-called NBC rings travel northwestward along the Brazilian coast, until they reach the island chain of the Lesser Antilles and disintegrate. These rings contribute substantially to the upper limb return flow of the Atlantic Meridional Overturning Circulation by carrying South Atlantic Water into the northern subtropical gyre. Their relevance for the northward transport of South Atlantic Water depends on the frequency of their generation as well as on their horizontal and vertical structure. The ring shedding and propagation and the complex interaction of the rings with the Lesser Antilles are investigated in the ? Family of Linked Atlantic Model Experiments (FLAME) model. The ring properties simulated in FLAME reach the upper limit of the observed rings in diameter and agree with recent observations on seasonal variability, which indicates a maximum shedding during the first half of the year. When the rings reach the shallow topography of the Lesser Antilles, they are trapped by the island triangle of St. Lucia, Barbados and Tobago and interact with the island chain. The model provides a resolution that is capable of resolving the complex topographic conditions at the islands and illuminates various possible fates for the water contained in the rings. It also reproduces laboratory experiments that indicate that both cyclones and anticyclones are formed after a ring passes through a topographic gap. Trajectories of artificial floats, which were inserted into the modeled velocity field, are used to investigate the pathways of the ring cores and their fate after they encounter the Lesser Antilles. The majority of the floats entered the Caribbean, while the northward Atlantic pathway was found to be of minor importance. No prominent

  6. Inorganic glass ceramic slip rings

    Science.gov (United States)

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

    1972-01-01

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

  7. Uniquely Strongly Clean Group Rings

    Institute of Scientific and Technical Information of China (English)

    WANG XIU-LAN

    2012-01-01

    A ring R is called clean if every element is the sum of an idempotent and a unit,and R is called uniquely strongly clean (USC for short) if every element is uniquely the sum of an idempotent and a unit that commute.In this article,some conditions on a ring R and a group G such that RG is clean are given.It is also shown that if G is a locally finite group,then the group ring RG is USC if and only if R is USC,and G is a 2-group.The left uniquely exchange group ring,as a middle ring of the uniquely clean ring and the USC ring,does not possess this property,and so does the uniquely exchange group ring.

  8. Antiproton chain of the FAIR storage rings

    International Nuclear Information System (INIS)

    Katayama, T; Kamerdzhiev, V; Lehrach, A; Maier, R; Prasuhn, D; Stassen, R; Stockhorst, H; Herfurth, F; Lestinsky, M; Litvinov, Yu A; Steck, M; Stöhlker, T

    2015-01-01

    In the Modularized Start Version of the Facility of Antiproton and Ion Research (FAIR) at Darmstadt Germany, the 3 GeV antiprotons are precooled in the collector ring and accumulated in the high energy storage ring (HESR). They are further accelerated to 14 GeV or decelerated to 1 GeV for the experiments with a high-density internal target. The powerful beam cooling devices, stochastic cooling and electron cooling will support the provision of a high-resolution antiproton beam. The other option of FAIR is to prepare the low energy, 300 keV antiproton beam connecting the existing storage rings ESR and CRYRING with HESR. Beam physics issues related with these concepts are described. (paper)

  9. The cryogenic storage ring CSR

    Science.gov (United States)

    von Hahn, R.; Becker, A.; Berg, F.; Blaum, K.; Breitenfeldt, C.; Fadil, H.; Fellenberger, F.; Froese, M.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; Heber, O.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lange, M.; Laux, F.; Lohmann, S.; Menk, S.; Meyer, C.; Mishra, P. M.; Novotný, O.; O'Connor, A. P.; Orlov, D. A.; Rappaport, M. L.; Repnow, R.; Saurabh, S.; Schippers, S.; Schröter, C. D.; Schwalm, D.; Schweikhard, L.; Sieber, T.; Shornikov, A.; Spruck, K.; Sunil Kumar, S.; Ullrich, J.; Urbain, X.; Vogel, S.; Wilhelm, P.; Wolf, A.; Zajfman, D.

    2016-06-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm-3 is derived, equivalent to a room-temperature pressure below 10-14 mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  10. The cryogenic storage ring CSR.

    Science.gov (United States)

    von Hahn, R; Becker, A; Berg, F; Blaum, K; Breitenfeldt, C; Fadil, H; Fellenberger, F; Froese, M; George, S; Göck, J; Grieser, M; Grussie, F; Guerin, E A; Heber, O; Herwig, P; Karthein, J; Krantz, C; Kreckel, H; Lange, M; Laux, F; Lohmann, S; Menk, S; Meyer, C; Mishra, P M; Novotný, O; O'Connor, A P; Orlov, D A; Rappaport, M L; Repnow, R; Saurabh, S; Schippers, S; Schröter, C D; Schwalm, D; Schweikhard, L; Sieber, T; Shornikov, A; Spruck, K; Sunil Kumar, S; Ullrich, J; Urbain, X; Vogel, S; Wilhelm, P; Wolf, A; Zajfman, D

    2016-06-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm(-3) is derived, equivalent to a room-temperature pressure below 10(-14) mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  11. The cryogenic storage ring CSR

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, R. von; Becker, A.; Berg, F.; Blaum, K.; Fadil, H.; Fellenberger, F.; Froese, M.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lange, M.; Laux, F.; Lohmann, S.; Menk, S. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); and others

    2016-06-15

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm{sup −3} is derived, equivalent to a room-temperature pressure below 10{sup −14} mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  12. A ring imaging Cherenkov counter for the AMS experiment: simulation, prototype and perspective; Un imageur d'anneaux tcherenkov pour l'experience AMS: simulation, prototypie et perspectives physiques

    Energy Technology Data Exchange (ETDEWEB)

    Thuillier, T

    2000-05-01

    The AMS spectrometer is scheduled to be installed on the International Space Station ISS in 2003. The detector will be equipped with a Ring Imaging Cherenkov Counter (RICH). The report starts with a presentation of the physics goals of AMS and continues with a description of the spectrometer. The RICH detector response and event reconstruction is then described and detailed. The presentation proceeds with a simulation study of cosmic ray nuclei expected with the AMS RICH counter in space. Next, the thesis reports on the research and development of a RICH prototype built and tested in the period 1997-1999 in the Grenoble Institute of Nuclear Science (ISN). The response of the prototype and its calibration are described. Tests have been performed with cosmic rays at ground and ion beam at GSI-Darmstadt. The data analysis of the test campaigns is then presented and compared with simulation results. Finally, a dedicated test of Albedo particle Rejection Power of the RICH detector is reported. (author)

  13. Design of low energy ring(s)

    CERN Document Server

    Lachaize, Antoine

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

  14. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2012-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...

  15. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  16. Ring Confidential Transactions

    Directory of Open Access Journals (Sweden)

    Shen Noether

    2016-12-01

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

  17. Effects of different reaction mediums on ring opening polymerization ...

    African Journals Online (AJOL)

    This work examined the effects of reaction conditions on ring opening ... of this study was to observe molecular weight distribution, conversion rates, and thermal ... M monomer and 0.56 M solvent), 10 mg lipase were used in the experiments.

  18. Heat transfer behaviors in round tube with conical ring inserts

    International Nuclear Information System (INIS)

    Promvonge, P.

    2008-01-01

    To increase convection heat transfer in a uniform heat flux tube by a passive method, several conical rings used as turbulators are mounted over the test tube. The effects of the conical ring turbulator inserts on the heat transfer rate and friction factor are experimentally investigated in the present work. Conical rings with three different diameter ratios of the ring to tube diameter (d/D = 0.5, 0.6, 0.7) are introduced in the tests, and for each ratio, the rings are placed with three different arrangements (converging conical ring, referred to as CR array, diverging conical ring, DR array and converging-diverging conical ring, CDR array). In the experiment, cold air at ambient condition for Reynolds numbers in a range of 6000-26,000 is passed through the uniform heat flux circular tube. It is found that the ring to tube diameter ratio and the ring arrays provide a significant effect on the thermal performance of the test tube. The experimental results demonstrate that the use of conical ring inserts leads to a higher heat transfer rate than that of the plain surface tube, and the DR array yields a better heat transfer than the others. The results are also correlated in the form of Nusselt number as a function of Reynolds number, Prandtl number and diameter ratio. An augmentation of up to 197%, 333%, and 237% in Nusselt number is obtained in the turbulent flow for the CR, DR and CDR arrays, respectively, although the effect of using the conical ring causes a substantial increase in friction factor

  19. Small electrostatic storage rings; also for highly charged ions?

    International Nuclear Information System (INIS)

    Moeller, S.P.; Pedersen, U.V.

    2001-01-01

    Two years ago, a small electrostatic storage ring ELISA (electrostatic ion storage ring, Aarhus) was put into operation. The design of this small 7 m circumference ring was based on electrostatic deflection plates and quadrupoles. This is in contrast to the larger ion storage rings, which are based on magnetic focusing and deflection. The result is a small, relatively inexpensive, storage ring being able to store ions of any mass and any charge at low energy ( -11 mbar resulting in storage times of several tens of seconds for singly charged ions. The maximum number of singly charged ions that can be stored is a few 10 7 . Several experiments have already been performed in ELISA. These include lifetime studies of metastable ions and studies of fullerenes and metal-cluster ions. Lasers are also used for excitation of the circulating ions. Heating/cooling of the ring is possible. Cooling of the ring leads to significantly lower pressures, and correspondingly longer lifetimes. A change of the temperature of the vacuum chambers surrounding the ion beam also leads to a change of the spectrum of the black-body radiation, which has a significant influence on weakly bound negative ions. At the time of writing, at least two other electrostatic storage rings are being built, and more are planned. In the following, the electrostatic storage ring ELISA will be described, and results from some of the initial experiments demonstrating the performance will be shown. The relative merits of such a ring, as opposed to the larger magnetic rings and the smaller ion traps will be discussed. The potential for highly charged ions will be briefly mentioned. (orig.)

  20. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2014-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

  1. Tree Rings: Timekeepers of the Past.

    Science.gov (United States)

    Phipps, R. L.; McGowan, J.

    One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…

  2. Proton storage rings

    International Nuclear Information System (INIS)

    Rau, R.R.

    1978-04-01

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

  3. Ring-constrained Join

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  4. Femtoslicing in Storage Rings

    CERN Document Server

    Khan, Shaukat

    2005-01-01

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

  5. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana

    2013-10-15

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  6. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana; Vasilakopoulos, Thodoris C.; Jeong, Youncheol; Lee, Hyojoon; Rogers, Simon A.; Sakellariou, Georgios; Allgaier, Jü rgen B.; Takano, Atsushi; Brá s, Ana Rita E; Chang, Taihyun; Gooß en, Sebastian; Pyckhout-Hintzen, Wim; Wischnewski, Andreas; Hadjichristidis, Nikolaos; Richter, Dieter R.; Rubinstein, Michael H.; Vlassopoulos, Dimitris

    2013-01-01

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  7. Alpha - Skew Pi - Armendariz Rings

    Directory of Open Access Journals (Sweden)

    Areej M Abduldaim

    2018-03-01

    Full Text Available In this article we introduce a new concept called Alpha-skew Pi-Armendariz rings (Alpha - S Pi - ARas a generalization of the notion of Alpha-skew Armendariz rings.Another important goal behind studying this class of rings is to employ it in order to design a modern algorithm of an identification scheme according to the evolution of using modern algebra in the applications of the field of cryptography.We investigate general properties of this concept and give examples for illustration. Furthermore, this paperstudy the relationship between this concept and some previous notions related to Alpha-skew Armendariz rings. It clearly presents that every weak Alpha-skew Armendariz ring is Alpha-skew Pi-Armendariz (Alpha-S Pi-AR. Also, thisarticle showsthat the concepts of Alpha-skew Armendariz rings and Alpha-skew Pi- Armendariz rings are equivalent in case R is 2-primal and semiprime ring.Moreover, this paper proves for a semicommutative Alpha-compatible ringR that if R[x;Alpha] is nil-Armendariz, thenR is an Alpha-S Pi-AR. In addition, if R is an Alpha - S Pi -AR, 2-primal and semiprime ring, then N(R[x;Alpha]=N(R[x;Alpha]. Finally, we look forwardthat Alpha-skew Pi-Armendariz rings (Alpha-S Pi-ARbe more effect (due to their properties in the field of cryptography than Pi-Armendariz rings, weak Armendariz rings and others.For these properties and characterizations of the introduced concept Alpha-S Pi-AR, we aspire to design a novel algorithm of an identification scheme.

  8. Flexible ring seal

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  9. Magnetization of two coupled rings

    International Nuclear Information System (INIS)

    Avishai, Y; Luck, J M

    2009-01-01

    We investigate the persistent currents and magnetization of a mesoscopic system consisting of two clean metallic rings sharing a single contact point in a magnetic field. Many novel features with respect to the single-ring geometry are underlined, including the explicit dependence of wavefunctions on the Aharonov-Bohm fluxes, the complex pattern of two-fold and three-fold degeneracies, the key role of length and flux commensurability, and in the case of commensurate ring lengths the occurrence of idle levels which do not carry any current. Spin-orbit interactions, induced by the electric fields of charged wires threading the rings, give rise to a peculiar version of the Aharonov-Casher effect where, unlike for a single ring, spin is not conserved. Remarkably enough, this can only be realized when the Aharonov-Bohm fluxes in both rings are neither integer nor half-integer multiples of the flux quantum

  10. FLSR - The Frankfurt low energy storage ring

    International Nuclear Information System (INIS)

    Stiebing, K.E.; Alexandrov, V.; Doerner, R.; Enz, S.; Kazarinov, N.Yu.; Kruppi, T.; Schempp, A.; Schmidt Boecking, H.; Voelp, M.; Ziel, P.; Dworak, M.; Dilfer, W.

    2010-01-01

    An electrostatic storage ring for low-energy ions with a design energy of 50 keV is presently being set up at the Institut fuer Kernphysik der Johann Wolfgang Goethe-Universitaet Frankfurt am Main, Germany (IKF). This new device will provide a basis for new experiments on the dynamics of ionic and molecular collisions, as well as for high precision and time resolved laser spectroscopy. In this article, the design parameters of this instrument are reported.

  11. Almagest, a new trackless ring finding algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Lamanna, G., E-mail: gianluca.lamanna@cern.ch

    2014-12-01

    A fast ring finding algorithm is a crucial point to allow the use of RICH in on-line trigger selection. The present algorithms are either too slow (with respect to the incoming data rate) or need the information coming from a tracking system. Digital image techniques, assuming limited computing power (as for example Hough transform), are not perfectly robust for what concerns the noise immunity. We present a novel technique based on Ptolemy's theorem for multi-ring pattern recognition. Starting from purely geometrical considerations, this algorithm (also known as “Almagest”) allows fast and trackless rings reconstruction, with spatial resolution comparable with other offline techniques. Almagest is particularly suitable for parallel implementation on multi-cores machines. Preliminary tests on GPUs (multi-cores video card processors) show that, thanks to an execution time smaller than 10 μs per event, this algorithm could be employed for on-line selection in trigger systems. The user case of the NA62 RICH trigger, based on GPU, will be discussed. - Highlights: • A new algorithm for fast multiple ring searching in RICH detectors is presented. • The Almagest algorithm exploits the computing power of Graphics processers (GPUs). • A preliminary implementation for on-line triggering in the NA62 experiment shows encouraging results.

  12. Guide to the Main Ring DO overpass

    International Nuclear Information System (INIS)

    Turkot, F.

    1985-01-01

    The DO overpass is a modification of the beam orbit in Main Ring in order to better accommodate a Tevatron collider detector at DO. The orbit is moved up approx. 51 inches over most of the long straight section at DO, thus making the Main Ring the world's first non-planar proton synchrotron. A similar overpass, but with four times the displacement, is planned for the CDF detector at the BO straight section. The nominal separation between the beam orbit in the Main Ring and the orbit in the Tevatron is 25.5 inches. Early in the design study of a detector that would utilize the Tevatron is a anti pp collider, it was apparent that a larger separation at the detector was highly desirable. In 1981, Tom Collins proposed a specific lattice geometry in the Main Ring for achieving larger separation, called ''the screw beam''. His proposal has served as the basis for the design of both the BO and DO overpasses. The main purpose of this report is to describe in some detail the implementation of the DO overpass. Topics to be covered include: (a) geometry of the overpass orbit, (b) the new hardware in the tunnel, (c) the power supply system, (d) the control facility, (e) accelerator beam dynamics ramifications, and (f) commissioning experience. A secondary purpose is to provide a fairly complete ''bibliography'' to the sources of information on the overpass. 17 refs., 17 figs

  13. Novel Fiber-Optic Ring Acoustic Emission Sensor.

    Science.gov (United States)

    Wei, Peng; Han, Xiaole; Xia, Dong; Liu, Taolin; Lang, Hao

    2018-01-13

    Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

  14. Novel Fiber-Optic Ring Acoustic Emission Sensor

    Directory of Open Access Journals (Sweden)

    Peng Wei

    2018-01-01

    Full Text Available Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

  15. Split ring containment attachment device

    International Nuclear Information System (INIS)

    Sammel, A.G.

    1996-01-01

    A containment attachment device is described for operatively connecting a glovebag to plastic sheeting covering hazardous material. The device includes an inner split ring member connected on one end to a middle ring member wherein the free end of the split ring member is inserted through a slit in the plastic sheeting to captively engage a generally circular portion of the plastic sheeting. A collar potion having an outer ring portion is provided with fastening means for securing the device together wherein the glovebag is operatively connected to the collar portion. 5 figs

  16. Radar imaging of Saturn's rings

    Science.gov (United States)

    Nicholson, Philip D.; French, Richard G.; Campbell, Donald B.; Margot, Jean-Luc; Nolan, Michael C.; Black, Gregory J.; Salo, Heikki J.

    2005-09-01

    We present delay-Doppler images of Saturn's rings based on radar observations made at Arecibo Observatory between 1999 and 2003, at a wavelength of 12.6 cm and at ring opening angles of 20.1°⩽|B|⩽26.7°. The average radar cross-section of the A ring is ˜77% relative to that of the B ring, while a stringent upper limit of 3% is placed on the cross-section of the C ring and 9% on that of the Cassini Division. These results are consistent with those obtained by Ostro et al. [1982, Icarus 49, 367-381] from radar observations at |B|=21.4°, but provide higher resolution maps of the rings' reflectivity profile. The average cross-section of the A and B rings, normalized by their projected unblocked area, is found to have decreased from 1.25±0.31 to 0.74±0.19 as the rings have opened up, while the circular polarization ratio has increased from 0.64±0.06 to 0.77±0.06. The steep decrease in cross-section is at variance with previous radar measurements [Ostro et al., 1980, Icarus 41, 381-388], and neither this nor the polarization variations are easily understood within the framework of either classical, many-particle-thick or monolayer ring models. One possible explanation involves vertical size segregation in the rings, whereby observations at larger elevation angles which see deeper into the rings preferentially see the larger particles concentrated near the rings' mid-plane. These larger particles may be less reflective and/or rougher and thus more depolarizing than the smaller ones. Images from all four years show a strong m=2 azimuthal asymmetry in the reflectivity of the A ring, with an amplitude of ±20% and minima at longitudes of 67±4° and 247±4° from the sub-Earth point. We attribute the asymmetry to the presence of gravitational wakes in the A ring as invoked by Colombo et al. [1976, Nature 264, 344-345] to explain the similar asymmetry long seen at optical wavelengths. A simple radiative transfer model suggests that the enhancement of the azimuthal

  17. Magnetic ring for stripping enhancement

    International Nuclear Information System (INIS)

    Selph, F.

    1992-10-01

    A ring designed to recycle ions through a stripping medium offers the possibility for increasing output of the desired charge state by up to 4x. This could be a very important component of a Radioactive Nuclear Beam Facility. In order for such a ring to work effectively it must satisfy certain design conditions. These include achromaticity at the stripper, a dispersed region for an extraction magnet, and a number of first and higher order optics constraints which are necessary to insure that the beam emittance is not degraded unduly by the ring. An example is given of a candidate design of a stripping ring

  18. Saturn's Rings Edge-on

    Science.gov (United States)

    1995-01-01

    In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

  19. Acceleration of magnetized plasma rings

    International Nuclear Information System (INIS)

    Hartman, D.; Eddleman, J.; Hammer, J.H.

    1982-01-01

    One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

  20. ring og refleksion

    DEFF Research Database (Denmark)

    Wahlgren, B.; Rattleff, Pernille; Høyrup, S.

    State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen.......State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen....

  1. Damping rings for CLIC

    CERN Document Server

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

    2001-01-01

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

  2. Does the sun ring

    International Nuclear Information System (INIS)

    Isaak, G.R.

    1978-01-01

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

  3. Status of the Frankfurt low energy electrostatic storage ring (FLSR)

    International Nuclear Information System (INIS)

    King, F; Kruppi, T; Müller, J; Dörner, R; Schmidt, L Ph H; Schmidt-Böcking, H; Stiebing, K E

    2015-01-01

    Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections. (paper)

  4. Present status of the ion ring compressor approach to fusion

    International Nuclear Information System (INIS)

    Fleischmann, H.H.

    1975-01-01

    A short review is given of the present research status with regard to the Ion Ring Compressor. A consideration of the reactor characteristics of this fusion scheme indicates the potential for a number of technologically and economically interesting features, in particular with respect to the high-confinement characteristics expected for such minimum-B configurations. Experimental results from the RECE-program at Cornell indicate generally good gross stability of strong electron rings, including purely collisional decay, stability against field perturbations and others. Most-recent experiments have extended the ring lifetime to more than 2 x 10 5 electron orbits. Strong electron rings have been shifted over an axial distance of up to 30 cm. Experiments with magnetic-field insulated diodes indicate ion pulses of up to 300 nsec, and field insulation of up to 800 nsec when metallic electrodes are used

  5. Status of the Frankfurt low energy electrostatic storage ring (FLSR)

    Science.gov (United States)

    King, F.; Kruppi, T.; Müller, J.; Dörner, R.; Schmidt, L. Ph H.; Schmidt-Böcking, H.; Stiebing, K. E.

    2015-11-01

    Frankfurt low-energy storage ring (FLSR) is an electrostatic storage ring for low-energy ions up to q · 80 keV (q being the ion charge state) at Institut für Kernphysik der Goethe-Universität, Frankfurt am Main, Germany. It has especially been designed to provide a basis for experiments on the dynamics of ionic and molecular collisions in complete kinematics, as well as for high precision and time resolved laser spectroscopy. The ring has ‘racetrack’ geometry with a circumference of 14.23 m. It comprises four experimental/diagnostic sections with regions of enhanced ion density (interaction regions). First beam has successfully been stored in FLSR in summer 2013. Since then the performance of the ring has continuously been improved and an electron target for experiments on dissociative recombination has been installed in one of the experimental sections.

  6. Blowing smoke rings in superfluid helium

    International Nuclear Information System (INIS)

    Allum, D.R.; McClintock, P.V.E.

    1977-01-01

    Among experiments designed to investigate the properties of superfluids, measurements are discussed which aim at determining the variation in the speed of an ion with the size of the electric field propelling it through liquid helium. The experimental set up using helium ions is described. The velocity-field characteristic shows an initial rise but at a higher electric field the ions exhibit the curious behaviour of slowing down before again increasing speed with force. The reason for this region of slowing down is here explained as being due to the fact that the charge is no longer carried by a free ion but, rather, by a charged vortex ring. As the ion speeds thorugh the liquid it suddenly creates a vortex ring and as one of the fundamental characteristics of a vortex ring is that its velocity is inversely proportional to its radius the speed reduction is explained. The subsequent rise in the characteristic indicates that the charge carriers are no longer straightforward charged vortex rings. This behaviour is attributed to ions 'falling off' their rings soon after creating them. It would appear that the force exerted by the electric field is so large that it overcomes the hydrodynamic force which binds the ion to the slowly moving vortex, enabling the ion to escape and accelerate away. In a final levelling off part of the characteristic curve it is considered that the ions are travelling faster than the critical velocity for roton creation, but are moving far below that for phonon creation. One may therefore conclude that the ion, as it travels through the liquid, transforms energy extracted from the electric field into rotons, which fan out forming a sort of wake behind it. (U.K.)

  7. How Jupiter's Ring Was Discovered.

    Science.gov (United States)

    Elliot, James; Kerr, Richard

    1985-01-01

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

  8. Pyrimidine-pyridine ring interconversion

    NARCIS (Netherlands)

    Plas, van der H.C.

    2003-01-01

    This chapter discusses the pyrimidine-to-pyridine ring transformation and pyridine-to-pyrimidine ring transformation. In nucleophile-induced pyrimidine-to-pyridine rearrangements, two types of reactions can be distinguished depending on the structure of the nucleophile: (1) reactions in which the

  9. Binomial Rings: Axiomatisation, Transfer and Classification

    OpenAIRE

    Xantcha, Qimh Richey

    2011-01-01

    Hall's binomial rings, rings with binomial coefficients, are given an axiomatisation and proved identical to the numerical rings studied by Ekedahl. The Binomial Transfer Principle is established, enabling combinatorial proofs of algebraical identities. The finitely generated binomial rings are completely classified. An application to modules over binomial rings is given.

  10. Discovery Of B Ring Propellers In Cassini UVIS, And ISS

    Science.gov (United States)

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

    2012-10-01

    We present evidence for the existence of propellers in Saturn's B ring by combining data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We identify two propeller populations: (1) tens of degrees wide propellers in the dense B ring core, and (2) smaller, more A ring like, propellers populating the inner B ring. The prototype of the first population is an object observed at 18 different epochs between 2005 and 2010. The ubiquitous propeller "S" shape is seen both in UVIS occultations as an optical depth depletion and in ISS as a 40 degrees wide bright stripe in unlit geometries and dark in lit geometries. Combining the available Cassini data we infer that the object is a partial gap embedded in the high optical depth region of the B ring. The gap moves at orbital speed consistent with its radial location. From the radial separation of the propeller wings we estimate that the embedded body, which causes the propeller structure, is about 1.5km in size located at a=112,921km. The UVIS occultations indicate an asymmetric propeller "S" shape. Since the object is located at an edge between high and relatively low optical depth, this asymmetry is most likely a consequence of the strong surface mass density gradient. We estimate that there are possibly dozen up to 100 other propeller objects in Saturn's B ring. The location of the discovered body, at an edge of a dense ringlet within the B ring, suggests a novel mechanism for the up to now illusive B ring irregular large-scale structure of alternating high and low optical depth ringlets. We propose that this B ring irregular structure may have its cause in the presence of many embedded bodies that shepherd the individual B ring ringlets.

  11. Ionization cooling ring for muons

    Directory of Open Access Journals (Sweden)

    R. Palmer

    2005-06-01

    Full Text Available Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second U.S. Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such real-world effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49.

  12. Experimentqal and analytical study on thermocracking of alumina ceramic ring in a mechanical seal

    Science.gov (United States)

    Komiya, M.; Matsuda, K.; Kaneta, M.

    1994-04-01

    A mechanism of thermocracking, which occurs in an alumina ceramic ring of a mechanical face seal, is proposed based on experimental and analytical results. Methods for its prevention are also discussed. The experiments were conducted using an external type mechanical face seal composed of a carbon ring and three kinds of alumina ceramic rings, with distilled water as the liquid to be sealed. By using a layer of gold vacuum deposited onto the surface of the ceramic ring as a part of a DC circuit, the moment of crack initiation was identified. The thermal stresses produced in the ceramic ring by frictional heating were calculated using finite element analysis.

  13. Vortices trapped in discrete Josephson rings

    International Nuclear Information System (INIS)

    Van der Zanta, H.S.J.; Orlando, T.P.; Watanabe, Shinya; Strogatz, S.H.

    1994-01-01

    We report the first measurements of current- (I-V) characteristics of discrete rings of Josephson junctions. As I is increased, resonant steps appear in the I-V curve, due to phase-locking between a propagating, trapped vortex and the linear waves excited in its wake. Unexpectedly, the phase velocity of the linear waves, not the group velocity, is the physically important quantity and mode numbers outside the Brillouin zone are relevant. Our measurements show that away from the resonant steps, a single vortex can move in an environment with very little damping, making the discrete one-dimensional ring a well-defined model system for the study of ballistic and quantum vortex experiments. ((orig.))

  14. Vortices trapped in discrete Josephson rings

    Energy Technology Data Exchange (ETDEWEB)

    Van der Zanta, H.S.J. [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Orlando, T.P. [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Watanabe, Shinya [Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Strogatz, S.H. [Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    1994-12-01

    We report the first measurements of current- (I-V) characteristics of discrete rings of Josephson junctions. As I is increased, resonant steps appear in the I-V curve, due to phase-locking between a propagating, trapped vortex and the linear waves excited in its wake. Unexpectedly, the phase velocity of the linear waves, not the group velocity, is the physically important quantity and mode numbers outside the Brillouin zone are relevant. Our measurements show that away from the resonant steps, a single vortex can move in an environment with very little damping, making the discrete one-dimensional ring a well-defined model system for the study of ballistic and quantum vortex experiments. ((orig.)).

  15. Evaluation of ring impedance of the Photon Factory storage ring

    International Nuclear Information System (INIS)

    Kiuchi, T.; Izawa, M.; Tokumoto, S.; Hori, Y.; Sakanaka, S.; Kobayashi, M.; Kobayakawa, H.

    1992-05-01

    The loss parameters of the ducts in the Photon Factory (PF) storage ring were evaluated using the wire method and the code TBCI. Both the measurement and the calculation were done for a different bunch length (σ) ranging from 23 to 80 ps. The PF ring impedance was estimated to be |Z/n|=3.2 Ω using the broadband impedance model. The major contribution to the impedance comes from the bellows and the gate valve sections. Improvements of these components will lower the ring impedance by half. (author)

  16. Tinkering at the main-ring lattice

    Energy Technology Data Exchange (ETDEWEB)

    Ohnuma, S.

    1982-08-23

    To improve production of usable antiprotons using the proton beam from the main ring and the lossless injection of cooled antiprotons into the main ring, modifications of the main ring lattice are recommended.

  17. Moving ring reactor 'Karin-1'

    International Nuclear Information System (INIS)

    1983-12-01

    The conceptual design of a moving ring reactor ''Karin-1'' has been carried out to advance fusion system design, to clarify the research and development problems, and to decide their priority. In order to attain these objectives, a D-T reactor with tritium breeding blanket is designed, a commercial reactor with net power output of 500 MWe is designed, the compatibility of plasma physics with fusion engineering is demonstrated, and some other guideline is indicated. A moving ring reactor is composed mainly of three parts. In the first formation section, a plasma ring is formed and heated up to ignition temperature. The plasma ring of compact torus is transported from the formation section through the next burning section to generate fusion power. Then the plasma ring moves into the last recovery section, and the energy and particles of the plasma ring are recovered. The outline of a moving ring reactor ''Karin-1'' is described. As a candidate material for the first wall, SiC was adopted to reduce the MHD effect and to minimize the interaction with neutrons and charged particles. The thin metal lining was applied to the SiC surface to solve the problem of the compatibility with lithium blanket. Plasma physics, the engineering aspect and the items of research and development are described. (Kako, I.)

  18. Quantum Fourier Transform Over Galois Rings

    OpenAIRE

    Zhang, Yong

    2009-01-01

    Galois rings are regarded as "building blocks" of a finite commutative ring with identity. There have been many papers on classical error correction codes over Galois rings published. As an important warm-up before exploring quantum algorithms and quantum error correction codes over Galois rings, we study the quantum Fourier transform (QFT) over Galois rings and prove it can be efficiently preformed on a quantum computer. The properties of the QFT over Galois rings lead to the quantum algorit...

  19. Soft Congruence Relations over Rings

    Science.gov (United States)

    Xin, Xiaolong; Li, Wenting

    2014-01-01

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

  20. Distributively generated matrix near rings

    International Nuclear Information System (INIS)

    Abbasi, S.J.

    1993-04-01

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

  1. SMARANDACHE NON-ASSOCIATIVE RINGS

    OpenAIRE

    Vasantha, Kandasamy

    2002-01-01

    An associative ring is just realized or built using reals or complex; finite or infinite by defining two binary operations on it. But on the contrary when we want to define or study or even introduce a non-associative ring we need two separate algebraic structures say a commutative ring with 1 (or a field) together with a loop or a groupoid or a vector space or a linear algebra. The two non-associative well-known algebras viz. Lie algebras and Jordan algebras are mainly built using a vecto...

  2. The small displacement elastic solution to the ball-on-ring testing method

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund

    2012-01-01

    The ball-on-ring experiment is used for testing of the biaxial strength of ceramics. In this work the solution for the stress distribution and displacements of the disc specimen in the ball-on-ring experiment are determined on closed form. The solution comprises the displacement field and its...

  3. Separation of electron ion ring components (computational simulation and experimental results)

    International Nuclear Information System (INIS)

    Aleksandrov, V.S.; Dolbilov, G.V.; Kazarinov, N.Yu.; Mironov, V.I.; Novikov, V.G.; Perel'shtejn, Eh.A.; Sarantsev, V.P.; Shevtsov, V.F.

    1978-01-01

    The problems of the available polarization value of electron-ion rings in the regime of acceleration and separation of its components at the final stage of acceleration are studied. The results of computational simulation by use of the macroparticle method and experiments on the ring acceleration and separation are given. The comparison of calculation results with experiment is presented

  4. Separating rings detection in fuel channels of Embalse NPP

    International Nuclear Information System (INIS)

    Obrutsky, L.S.; Otero, P.A.; Schmidt, O.A.

    1988-01-01

    The design specifications of Embalse Nuclear Power Plants (CANDU Type Reactor 600Mw) define the positions to be taken by 4 separating rings of the fuel channels. Experience has demonstrated the displacement possibility of the above mentioned rings. It means a risk of contact between pressure tube and calandria tube. In order to determine the position of separating rings, an inspection system based on Eddy Currents technique was developed by CNEA personnel. Detection is performed through two special probes operating according the ''emitter-receiver'' principle. Obtained signals and its relative position are recorded in a video tape and registered in paper. The probe is telecommanded by an automatic equipment. In this paper the construction and calibration of the detection equipment is described, as well as the propulsion. Final results are also outlined in the inspection carried out in November 1986 when an effective displacement of separating rings was verified from its design position in most of the inspected tubes

  5. Prototype moving-ring reactor

    International Nuclear Information System (INIS)

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

    1982-01-01

    We have completed a design of the Prototype Moving-Ring Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma (Compact Toroids). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three burn stations. Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for 1/3 of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power

  6. Autumn study on storage rings

    CERN Multimedia

    1974-01-01

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

  7. Minimal Gromov-Witten rings

    International Nuclear Information System (INIS)

    Przyjalkowski, V V

    2008-01-01

    We construct an abstract theory of Gromov-Witten invariants of genus 0 for quantum minimal Fano varieties (a minimal class of varieties which is natural from the quantum cohomological viewpoint). Namely, we consider the minimal Gromov-Witten ring: a commutative algebra whose generators and relations are of the form used in the Gromov-Witten theory of Fano varieties (of unspecified dimension). The Gromov-Witten theory of any quantum minimal variety is a homomorphism from this ring to C. We prove an abstract reconstruction theorem which says that this ring is isomorphic to the free commutative ring generated by 'prime two-pointed invariants'. We also find solutions of the differential equation of type DN for a Fano variety of dimension N in terms of the generating series of one-pointed Gromov-Witten invariants

  8. Cosmic rings from colliding galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Mitton, S

    1976-11-18

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

  9. Ring lasers - a brief history

    Science.gov (United States)

    Klein, Tony

    2017-10-01

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

  10. Stability of Moonlets Embedded in Rings

    Science.gov (United States)

    Lewis, Mark C.; Burdon, C.

    2011-04-01

    Previous work on moonlets assumed that they were just a single indestructible spherical particle and focused primarily on the effects such a body would have on the surrounding ring material (Lewis and Stewart 2009, Icarus 199:387-412; Sremcevic et al. 2007, Nature 449:1019-1021). Both observations and numerical simulations of Saturn's small inner moons show them as very low density rubble piles (Porco et al. 2007, Science 318:1602). Unlike the small moons, moonlets embedded in the ring material will experience regular collisions with self gravity wakes tens of meters across. Even with a single spherical core, these collisions can lead to the shedding of significant amounts of accreted material. We describe numerical simulations in which we explore the parameters required for stability of moonlets embedded in the ring material. Because of their location well inside the Roche limit, these bodies require either higher densities or some internal strength in order to stay together. We explore how much strength is required for these moonlets to be stable against the regular impacts they sustain in that environment. This work was funded by NSF AAG award number 0907972.

  11. The Jovian rings as observed from Jupiter.

    Science.gov (United States)

    Malinnikova Bang, A.; Joergensen, J. L.; Joergensen, P. S.; Denver, T.; Connerney, J. E. P.; Bolton, S. J.; Levin, S.

    2017-12-01

    Juno entered a highly eliptic orbit around Jupiter on the 4. July 2016. Since then, it has completed 8 perijove passages. The Magnetometer experiment consists of two measurement platforms mounted 10m and 12m from the spacecraft spin axis, on one of three large solar panels. Each magnetometer platform is equipped with two star trackers to provide accurate attitude information to the vector magnetometers. The star trackers are pointed 13deg from the (anti) spin vector, and clocked 180deg to avoid simultaneous blinding effects from bright Jupiter only 6000km away, during perijove. This brings Juno well inside the innermost known satellite, Metis. The star trackers pointing close to, and above the Jovian horizon for most of each rotation of Juno, has an excellent view of the Jovian ring systems with a beta-angle close to 180deg. We report on the ring imaging performed during the first 8 orbits, discuss the structure, optical depth and moon sheparding of the inner rings as measured so far.

  12. Ring insertions as light sources

    International Nuclear Information System (INIS)

    Green, G.K.

    1975-01-01

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

  13. Collector ring project at FAIR

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  14. Synlig læring

    DEFF Research Database (Denmark)

    Brandsen, Mads

    2017-01-01

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

  15. The circular RFQ storage ring

    International Nuclear Information System (INIS)

    Ruggiero, A.G.

    1998-01-01

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

  16. The Circular RFQ Storage Ring

    International Nuclear Information System (INIS)

    Ruggiero, A. G.

    1999-01-01

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

  17. Electrically charged dilatonic black rings

    International Nuclear Information System (INIS)

    Kunduri, Hari K.; Lucietti, James

    2005-01-01

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

  18. Low emittance electron storage rings

    Science.gov (United States)

    Levichev, E. B.

    2018-01-01

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

  19. Resonance capture and Saturn's rings

    International Nuclear Information System (INIS)

    Patterson, C.W.

    1986-05-01

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

  20. FLSR - The Frankfurt low energy storage ring

    Science.gov (United States)

    Stiebing, K. E.; Alexandrov, V.; Dörner, R.; Enz, S.; Kazarinov, N. Yu.; Kruppi, T.; Schempp, A.; Schmidt Böcking, H.; Völp, M.; Ziel, P.; Dworak, M.; Dilfer, W.

    2010-02-01

    An electrostatic storage ring for low-energy ions with a design energy of 50 keV is presently being set up at the Institut für Kernphysik der Johann Wolfgang Goethe-Universität Frankfurt am Main, Germany (IKF). This new device will provide a basis for new experiments on the dynamics of ionic and molecular collisions, as well as for high precision and time resolved laser spectroscopy. In this article, the design parameters of this instrument are reported.

  1. First results of cavity ring down signals from exhaled air

    Science.gov (United States)

    Revalde, G.; Grundšteins, K.; Alnis, J.; Skudra, A.

    2017-12-01

    In this paper we report first results from the developed cavity ring-down spectrometer for application in human breath analysis for the diagnostics of diabetes and later for early detection of lung cancer. Our cavity ring-down spectrometer works in UV region with pulsed Nd:YAG laser at 266 nm wavelength. First experiments allow us to determine acetone and benzene at the level bellow ppm. In our experiment, first results from breath samples from volunteers after doing different activities were collected and examined. Influence of the smoking on the breath signals also was examined.

  2. Accretion in Saturn's F Ring

    Science.gov (United States)

    Meinke, B. K.; Esposito, L. W.; Stewart, G.

    2012-12-01

    Saturn's F ring is the solar system's principal natural laboratory for direct observation of accretion and disruption processes. The ring resides in the Roche zone, where tidal disruption competes with self-gravity, which allows us to observe the lifecycle of moonlets. Just as nearby moons create structure at the B ring edge (Esposito et al. 2012) and the Keeler gap (Murray 2007), the F ring "shepherding" moons Prometheus and Pandora stir up ring material and create observably changing structures on timescales of days to decades. In fact, Beurle et al (2010) show that Prometheus makes it possible for "distended, yet gravitationally coherent clumps" to form in the F ring, and Barbara and Esposito (2002) predicted a population of ~1 km bodies in the ring. In addition to the observations over the last three decades, the Cassini Ultraviolet Imaging Spectrograph (UVIS) has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Seventeen of those 27 features are associated with clumps of ring material. Two features are opaque in occultation, which makes them candidates for solid objects, which we refer to as Moonlets. The 15 other features partially block stellar signal for 22 m to just over 3.7 km along the radial expanse of the occultation. Upon visual inspection of the occultation profile, these features resemble Icicles, thus we will refer to them as such here. The density enhancements responsible for such signal attenuations are likely due to transient clumping of material, evidence that aggregations of material are ubiquitous in the F ring. Our lengthy observing campaign reveals that Icicles are likely transient clumps, while Moonlets are possible solid objects. Optical depth is an indicator of clumping because more-densely aggregated material blocks more light; therefore, it is natural to imagine moonlets as later evolutionary stage of icicle, when looser clumps of material compact to form a feature that appears

  3. Double acting stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1986-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  4. Study for ILC Damping Ring at KEKB

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, J.W.; Fukuma, H.; Kanazawa, K.I.; Koiso, H.; Masuzawa, M.; Ohmi, Kazuhito; Ohnishi, Y.; Oide, Katsunobu; Suetsugu, Y.; Tobiyama, M.; /KEK, Tsukuba; Pivi, M.; /SLAC

    2011-11-04

    ILC damping ring consists of very low emittance electron and positron storage rings. It is necessary for ILC damping ring to study electron cloud effects in such low emittance positron ring. We propose a low emittance operation of KEKB to study the effects.

  5. Manipulation of vortex rings for flow control

    International Nuclear Information System (INIS)

    Toyoda, Kuniaki; Hiramoto, Riho

    2009-01-01

    This paper reviews the dynamics of vortex rings and the control of flow by the manipulation of vortex rings. Vortex rings play key roles in many flows; hence, the understanding of the dynamics of vortex rings is crucial for scientists and engineers dealing with flow phenomena. We describe the structures and motions of vortex rings in circular and noncircular jets, which are typical examples of flows evolving into vortex rings. For circular jets the mechanism of evolving, merging and breakdown of vortex rings is described, and for noncircular jets the dynamics of three-dimensional deformation and interaction of noncircular vortex rings under the effect of self- and mutual induction is discussed. The application of vortex-ring manipulation to the control of various flows is reviewed with successful examples, based on the relationship between the vortex ring dynamics and the flow properties. (invited paper)

  6. Structure and dynamics of ringed galaxies

    International Nuclear Information System (INIS)

    Buta, R.J.

    1984-01-01

    In many spiral and SO galaxies, single or multiple ring structures are visible in the disk. These inner rings (r), outer rings (R), and nuclear rings (nr) were investigated by means of morphology, photometry, and spectroscopy in order to provide basic data on a long neglected phenomenon. The metric properties of each ring are investigated and found to correlate with the structure of the parent galaxy. When properly calibrated, inner rings in barred (SB) systems can be used as geometric extragalactic distance indicators to distances in excess of 100 Mpc. Other statistics are presented that confirm previous indications that the rings have preferred shapes, relative sizes, and orientations with respect to bars. A survey is made of the less homogeneous non-barred (SA) ringed systems, and the causes of the inhomogeneity are isolated. It is shown that rings can be identified in multiple-ring SA systems that are exactly analogous to those in barred spirals

  7. Optimizing ring-based CSR sources

    International Nuclear Information System (INIS)

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

    2004-01-01

    produce colossal intensities even with fairly low beam currents. Until recently CSR has not typically been observed in electron storage rings because the electron bunch lengths are longer than the waveguide cutoff imposed by the dimensions of the vacuum chamber, so full-bunch coherent emission is suppressed. The first observations of CSR from storage rings were of quasi-chaotic bursts of intensity caused by density modulations in unstable electron bunches, similar to the self-amplified spontaneous emission (SASE) used in the design of several proposed free electron lasers. While studies of this ''bursting'' phenomenon have provided glimpses into the powers available with CSR, the unstable nature of the emission makes this a problematic THz source for scientific measurements. We have experimentally verified a model predicting where this unstable bursting regime will occur and have used this experience to design a new source where the bursting instability can be avoided. Stable CSR has been produced during machine experiments at the BESSY-II storage ring and the first scientific measurements using this CSR source were recently reported. This stable CSR emission is not driven by any instability, yet it extends to higher frequencies than predicted by a simple full-bunch coherence model. This model is described in these proceedings and elsewhere. The combination of the experimentally verified models for stable CSR as well as the threshold of which current levels will produce bursting instabilities allows us to fully design and optimize a new CSR source that will produce copious amounts of stable far-IR, THz and sub-THz, synchrotron radiation. CSR has also been recently observed in storage rings as a result of laser slicing of the beams. In this process, interaction of an electron beam with a femtosecond laser pulse co-propagating through a wiggler modulates the electron energies within a short slice of the electron bunch comparable with the duration of the laser pulse

  8. Successful betatron acceleration of kiloampere electron rings in RECE-Christa

    International Nuclear Information System (INIS)

    Taggart, D.P.; Parker, M.R.; Hopman, H.J.; Jayakumar, R.; Fleischmann, H.H.

    1984-01-01

    This paper reports on betatron acceleration experiments using the space-charge-neutralized electron rings in the RECE-Christa device. Magnetic probe and x-ray-absorption measurements indicate that electron ring currents of up to 2 kA were accelerated to 3.3 +- 0.3 MeV without indication of instabilities. A similar neutralization and acceleration method also appears applicable to electron rings generated in B/sub theta/-free configurations

  9. Pure subrings of the rings

    International Nuclear Information System (INIS)

    Tsarev, Andrei V

    2009-01-01

    Pure subrings of finite rank in the Z-adic completion of the ring of integers and in its homomorphic images are considered. Certain properties of these rings are studied (existence of an identity element, decomposability into a direct sum of essentially indecomposable ideals, condition for embeddability into a csp-ring, etc.). Additive groups of these rings and conditions under which these rings are subrings of algebraic number fields are described. Bibliography: 12 titles.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bromley, Benjamin C. [Department of Physics and Astronomy, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112 (United States); Kenyon, Scott J., E-mail: bromley@physics.utah.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138 (United States)

    2015-08-10

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

  11. Primitivity and weak distributivity in near rings and matrix near rings

    International Nuclear Information System (INIS)

    Abbasi, S.J.

    1993-08-01

    This paper shows the structure of matrix near ring constructed over a weakly distributive and primative near ring. It is proved that a weakly distributive primitive near ring is a ring and the matrix near rings constructed over it is also a bag. (author). 14 refs

  12. Ring wormholes via duality rotations

    Directory of Open Access Journals (Sweden)

    Gary W. Gibbons

    2016-09-01

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

  13. HYPERAUTOFLUORESCENT RING IN AUTOIMMUNE RETINOPATHY

    Science.gov (United States)

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

    2015-01-01

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

  14. TSR: A storage and cooling ring for HIE-ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-01

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

  15. TSR: A Storage Ring for HIE-ISOLDE

    CERN Document Server

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

    2016-01-01

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

  16. CMB lensing and giant rings

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-01

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

  17. Proton storage ring summer workshop

    International Nuclear Information System (INIS)

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

    1977-10-01

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

  18. New Main Ring control system

    International Nuclear Information System (INIS)

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

    1990-03-01

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

  19. SOR-RING: an electron storage ring dedicated to spectroscopy, 2

    International Nuclear Information System (INIS)

    Kitamura, H.; Miyahara, T.; Sato, S.; Watanabe, M.; Mitani, S.

    1976-01-01

    A 300 MeV electron storage ring to be used exclusively as a synchrotron radiation source for spectroscopy has been constructed in Institute for Nuclear Study (INS), University of Tokyo, Tanashi. Its useful spectral range lies between 40 and 2200 A. The 1.3 GeV electron synchrotron of INS currently being operated for high energy particle experiments serves as an injector. Electron beams are extracted from the synchrotron at 300 MeV, transported about twenty meters, and injected to the ring one pulse per second. In the test operation a current of 10 mA was stored with a lifetime of one hour, while the design goal determined by the Touschek effect is 100 mA with one hour, for operation in 300 MeV. Increase of operating energy up to 375 MeV is feasible with a minor modification of the present design. (auth.)

  20. Tree rings and radiocarbon calibration

    International Nuclear Information System (INIS)

    Barbetti, M.

    1999-01-01

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

  1. Adiabatic compression of ion rings

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  2. Superconducting proton ring for PETRA

    International Nuclear Information System (INIS)

    Baynham, E.

    1979-01-01

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

  3. The Cryogenic Storage Ring CSR

    OpenAIRE

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

    2016-01-01

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

  4. Supersymmetric rings in field theory

    International Nuclear Information System (INIS)

    Blanco-Pillado, Jose J.; Redi, Michele

    2006-01-01

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

  5. Laparoscopic appendicectomy using endo-ring applicator and fallope rings

    International Nuclear Information System (INIS)

    Ali, Iyoob V; Maliekkal, Joji I

    2009-01-01

    Wider adoption of laparoscopic appendicectomy (LA) is limited by problems in securing the appendiceal base as well as the cost and the duration compared with the open procedure. The objective of this study was to assess the feasibility and efficacy of a new method for securing the appendiceal base in LA, so as to make the entire procedure simpler and cheaper, and hence, more popular. Twenty-five patients who were candidates for appendicectomy (emergency as well as elective) and willing for the laparoscopic procedure were selected for this study. Ports used were 10 mm at the umbilicus, 5 mm at the lower right iliac fossa, and 10 mm at the left iliac fossa. Extremely friable, ruptured, or turgid organs of diameters larger than 8 mm were excluded from the study. The mesoappendix was divided close to the appendix by diathermy. Fallope rings were applied to the appendiceal base using a special ring applicator, and the appendix was divided and extracted through the lumen of the applicator. The procedure was successful in 23 (92%) cases, and the mean duration of the procedure was 20 minutes (15-32 minutes). There were no procedural complications seen during a median follow-up of two weeks. The equipment and rings were cheaper when compared with that of the standard methods of securing the base of the appendix. LA using fallope rings is a safe, simple, easy-to-learn, and economically viable method. (author)

  6. A new production technique for wear resistant ring-hammers

    Directory of Open Access Journals (Sweden)

    Li Shifeng

    2011-11-01

    Full Text Available Based on a great number of laboratory experiments, a new technique has been developed for producing wear resistant ring-hammers. In this technology, lost foam casting with iron sand was combined to make mold; a special alloy was used to inoculate the molten steel, and proper heat treatment was used to further improve mechanical properties of wear resistant ring-hammers. The influence of this new production technology on the microstructure and mechanical properties of wear resistant ring-hammers was studied. Results show that iron sand molding, having the inherent characteristic of sand molding, changes the type of metallic compounds, refines crystal grains and increases the fineness of microstructure. Practical experience verified that the properties of the ring-hammers produced with this new technique are as follows: tensile strength (Rm 720 MPa, impact toughness (ak > 210 J•cm-2 and hardness > 200 HB. After water quenching from 1,080℃ (holding for 4 h and tempering at 320℃ for 3 h, the best wear resistance is obtained, and the wear resistance is 1.6 times higher than that of common high manganese ring-hammers.

  7. Electron transport and coherence in semiconductor quantum dots and rings

    NARCIS (Netherlands)

    Van der Wiel, W.G.

    2002-01-01

    A number of experiments on electron transport and coherence in semiconductor vertical and lateral quantum dots and semiconductor rings is described. Quantum dots are often referred to as "artificial atoms", because of their similarities with real atoms. Examples of such atom-like properties that

  8. Oscillatory persistent currents in self-assembled quantum rings

    NARCIS (Netherlands)

    Kleemans, N.A.J.M.; Bominaar-Silkens, I.M.A.; Fomin, V.; Gladilin, V.N.; Granados, D.; Taboada, A.G.; Garcia, J.M.; Offermans, P.; Zeitler, U.; Christianen, P.C.M.; Maan, J.C.; Devreese, J.T.; Koenraad, P.M.

    2007-01-01

    We report the direct measurement of the persistent current carried by a single electron by means of magnetization experiments on self-assembled InAs/GaAs quantum rings. We measured the first Aharonov-Bohm oscillation at a field of 14 T, in perfect agreement with our model based on the structural

  9. The Omega Ring Imaging Cerenkov Detector readout system user's guide

    International Nuclear Information System (INIS)

    Hallewell, G.

    1984-11-01

    The manual describes the electronic readout system of the Ring Imaging Cerenkov Detector at the CERN Omega Spectrometer. The system is described in its configuration of September 1984 after the Rich readout system had been used in two Omega experiments. (U.K.)

  10. Magnetized jet creation using a ring laser and applications

    Science.gov (United States)

    Liang, Edison; Gao, Ian; Lu, Yingchao; Ji, Hantao; Follett, Russ; Froula, Dustin; Tzeferacos, Petros; Lamb, Donald; Bickel, Andrew; Sio, Hong; Li, Chi Kiang; Petrasso, Richard; Wei, Mingsheng; Fu, Wen; Han, Lily

    2017-10-01

    We have recently demonstrated a new robust platform of magnetized jet creation using 20 OMEGA beams to form a hollow ring. We will present the latest experimental results and their theoretical interpretation, and explore potential applications to laboratory astrophysics, fundamental plasma physics and other areas. We will also discuss the scaling of this platform to future NIF experiments.

  11. An iterative method for the analysis of Cherenkov rings in the HERA-B RICH

    International Nuclear Information System (INIS)

    Staric, M.; Krizan, P.

    1999-01-01

    A new method is presented for the analysis of data recorded with a Ring Imaging Cherenkov (RICH) counter. The method, an iterative sorting of hits on the photon detector, is particularly useful for events where rings overlap considerably. The algorithm was tested on simulated data for the HERA-B experiment

  12. Dynamics of a vortex ring moving perpendicularly to the axis of a rotating fluid

    NARCIS (Netherlands)

    Eisenga, A.H.M.; Verzicco, R.; Heijst, van G.J.F.

    1998-01-01

    The dynamics of a vortex ring moving orthogonally to the rotation vector of a uniformly rotating fluid is analysed by laboratory experiments and numerical simulations. In the rotating system the vortex ring describes a curved trajectory, turning in the opposite sense to the system's anti-clockwise

  13. Examination techniques for non-magnetic rings

    International Nuclear Information System (INIS)

    Metala, M.J.; Kilpatrick, N.L.; Frank, W.W.

    1990-01-01

    Until the introduction of 18Mn18Cr rings a few years ago, most non-magnetic steel rings for generator rotors were made from 18Mn5Cr alloy steel, which is highly susceptible to stress corrosion cracking in the presence of water. This, the latest in a series of papers on the subject of non-magnetic rings by the authors' company, provides a discussion of nondestructive examination of 18Mn5Cr rings for stress corrosion distress. With rings on the rotor, fluorescent penetrant, ultrasonic and special visual techniques are applied. With rings off the rotor, the fluorescent penetrant technique is used, with and without stress enhancement

  14. Ring diagrams and phase transitions

    International Nuclear Information System (INIS)

    Takahashi, K.

    1986-01-01

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

  15. WR stars with ring nebulae

    International Nuclear Information System (INIS)

    Tutukov, A.

    1982-01-01

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

  16. Alignment for new Subaru ring

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  17. Characteristic of Rings. Prime Fields

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-12-01

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

  18. Ring laser frequency biasing mechanism

    International Nuclear Information System (INIS)

    McClure, R.E.

    1975-01-01

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

  19. Counting problems for number rings

    NARCIS (Netherlands)

    Brakenhoff, Johannes Franciscus

    2009-01-01

    In this thesis we look at three counting problems connected to orders in number fields. First we study the probability that for a random polynomial f in Z[X] the ring Z[X]/f is the maximal order in Q[X]/f. Connected to this is the probability that a random polynomial has a squarefree

  20. Progressiv læring

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne

    2017-01-01

    SAMMENFATNING I denne evalueringsrapport præsenterer Nationalt Center for Kompetenceudvikling ved Aarhus Universitet (herefter NCK) og Rambøll Management Consulting (herefter Rambøll) den værktøjsspecifikke evaluering af Progressiv Læring som pædagogisk værktøj for de ni implementeringsskoler i s...

  1. Wands of the Black Ring

    Czech Academy of Sciences Publication Activity Database

    Pravda, Vojtěch; Pravdová, Alena

    2005-01-01

    Roč. 37, č. 7 (2005), s. 1277-1287 ISSN 0001-7701 R&D Projects: GA ČR GP202/03/P017; GA AV ČR KJB1019403 Institutional research plan: CEZ:AV0Z10190503 Keywords : algebraic classification * Petrov classification * black ring Subject RIV: BA - General Mathematics Impact factor: 1.550, year: 2005

  2. Substitution of matrices over rings

    NARCIS (Netherlands)

    Hautus, M.L.J.

    1995-01-01

    For a given commutative ring with an identity element, we define and study the substitution of a matrix with entries in into a matrix polynomial or rational function over . A Bezout-type remainder theorem and a "partial-substitution rule" are derived and used to obtain a number of results. The

  3. Exercises in modules and rings

    CERN Document Server

    Lam, TY

    2009-01-01

    This volume offers a compendium of exercises of varying degree of difficulty in the theory of modules and rings. All exercises are solved in full detail. Each section begins with an introduction giving the general background and the theoretical basis for the problems that follow.

  4. On commutativity theorems for rings

    Directory of Open Access Journals (Sweden)

    H. A. S. Abujabal

    1990-01-01

    Full Text Available Let R be an associative ring with unity. It is proved that if R satisfies the polynomial identity [xny−ymxn,x]=0(m>1,n≥1, then R is commutative. Two or more related results are also obtained.

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  6. From stationary annular rings to rotating Bessel beams

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2012-04-01

    Full Text Available contributions from the two ring-slits completely overlap (evident in Fig. 1), the angular rotation is non-zero and the entire field at P3 experiences the rotation. 3. EXPERIMENTAL METHODOLOGY The experimental setup used to generate superpositions of higher...) as a ?petal?-field. The field at the ring-slit hologram (i.e., the field at plane P1), we will term the ?singularity?-field and that formed at plane P2 (a distance of 2f from lens L4) will be termed as the ?spiral?-field. 4. RESULTS AND DISCUSSION...

  7. Helium and deuterium permeability in O-rings

    International Nuclear Information System (INIS)

    Lakner, J.F.

    1976-01-01

    To obtain more information on gas permeation through elastomeric O-rings, studies were performed on Parker Seal Company O-rings, Nos. 2-113, 2-006, 3-904, and 3-906, all made of a nitrile rubber. Also included in the tests was a valve packing (Autoclave Engineers) encased in AE Valve 20A-2142. Permeation experiments were run usually in duplicate to 82.7 MPa (12,000 psi) with helium and deuterium at room temperature. The data are extrapolated to give values for tritium

  8. Quantum versus thermally excited fluxoid transitions in a SQUID ring

    International Nuclear Information System (INIS)

    Kurkijaervi, J.

    1980-01-01

    The possibility of quantum tunneling as a mechanism for fluxoid transitions in a SQUID ring is carefully considered neglecting, however, dissipation arising from the quasiparticle current. The tunneling rates are compared with the thermally excited transition rates. The type of experiment Jackel et al. carried out in order to observe the thermal process is analyzed for observing the quantum tunneling. We find the expected result that the temperature at which the quantum process should begin to dominate depends essentially on ω 0 = 1/√LC of the ring. If an underdamped junction with C -13 F can be made the quantum tunneling temperature range should be easy to attain. (orig.)

  9. Electron--positron storage ring PETRA: plans and status

    International Nuclear Information System (INIS)

    Voss, G.A.

    1977-01-01

    Construction of the Electron-Positron Storage Ring PETRA was authorized October 20, 1975. At present most of the civil engineering work is completed and ring installation work is under way. All major components are on order and series production of bending magnets, quadrupoles, vacuum chambers and rf-resonators has started. Start-up of the machine is planned with a fourfold symmetry configuration with four active beam-beam interaction points. Five experimental facilities have been recommended for the first round of experiments scheduled to begin mid 79

  10. INMS measures an influx of molecules from Saturn's rings

    Science.gov (United States)

    Perry, M. E.

    2017-12-01

    In 1984, Connerney and Waite proposed water influx from Saturn's rings to explain the low electron densities measured during Pioneer and Voyager radio occultation experiments. Charge exchange with this minor species depleted the H+ ions and provided a faster path to electron recombination. With ice the primary constituent of the rings, water was the most likely in-falling molecule. During the Grand Finale orbits, Cassini's Ion and Neutral Mass Spectrometer (INMS) detected and quantified an influx from the rings. Unexpectedly, the primary influx molecules are CH4 and a heavier carbon-bearing species. Water was detected, but quantities were factors of ten lower than these other species. Distribution in both altitude and latitude are consistent with a ring influx. The concentration of the minor species in Saturn's atmosphere shows that they enter Saturn's atmosphere from the top. Both molecules have their highest concentrations at the highest altitudes, with concentrations >0.4% at 3,500 km altitude and only 0.02% at 2,700 km. Molecules from the rings deorbit to Saturn's atmosphere at altitudes near 4,000 km, consistent with the INMS measurements. The latitudinal dependence of the minor species indicates that their source is near the equatorial plane. At high altitudes, the minor species were observed primarily at zero latitude, where the 28u species was six times more concentrated than at 5° latitude. At lower altitudes, the peaking ratio was 1, indicating that the species had diffused and was fully mixed into Saturn's H2 atmosphere. The lighter molecule, CH4, diffuses more rapidly than the 28u species. INMS also detected both of these species during the earlier F-ring passes, finding that the neutrals were centered at the ring plane and extended 3,000 km (half width, half max) north and south.

  11. International Tree Ring Data Bank (ITRDB)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives. Data include raw treering measurements (most are...

  12. Vortex rings in classical and quantum systems

    International Nuclear Information System (INIS)

    Barenghi, C F; Donnelly, R J

    2009-01-01

    The study of vortex rings has been pursued for decades and is a particularly difficult subject. However, the discovery of quantized vortex rings in superfluid helium has greatly increased interest in vortex rings with very thin cores. While rapid progress has been made in the simulation of quantized vortex rings, there has not been comparable progress in laboratory studies of vortex rings in a viscous fluid such as water. This article overviews the history and current frontiers of classical and quantum vortex rings. After introducing the classical results, this review discusses thin-cored vortex rings in superfluid helium in section 2, and recent progress in understanding vortex rings of very thin cores propagating in water in section 3. (invited paper)

  13. Mathematical simulation of bearing ring grinding process

    Science.gov (United States)

    Koltunov, I. I.; Gorbunova, T. N.; Tumanova, M. B.

    2018-03-01

    The paper suggests the method of forming a solid finite element model of the bearing ring. Implementation of the model allowed one to evaluate the influence of the inner cylindrical surface grinding scheme on the ring shape error.

  14. Dynamics of long ring Raman fiber laser

    Science.gov (United States)

    Sukhanov, Sergey V.; Melnikov, Leonid A.; Mazhirina, Yulia A.

    2016-04-01

    The numerical model for dynamics of long fiber ring Raman laser is proposed. The model is based on the transport equations and Courant-Isaacson-Rees numerical method. Different regimes of a long ring fiber Raman laser are investigated.

  15. Genetics Home Reference: ring chromosome 20 syndrome

    Science.gov (United States)

    ... drugs. Prolonged seizure episodes known as non-convulsive status epilepticus also appear to be characteristic of ring chromosome ... K, Takahashi Y. Ring chromosome 20 and nonconvulsive status epilepticus. A new epileptic syndrome. Brain. 1997 Jun;120 ( ...

  16. Modeling and analysis on ring-type piezoelectric transformers.

    Science.gov (United States)

    Ho, Shine-Tzong

    2007-11-01

    This paper presents an electromechanical model for a ring-type piezoelectric transformer (PT). To establish this model, vibration characteristics of the piezoelectric ring with free boundary conditions are analyzed in advance. Based on the vibration analysis of the piezoelectric ring, the operating frequency and vibration mode of the PT are chosen. Then, electromechanical equations of motion for the PT are derived based on Hamilton's principle, which can be used to simulate the coupled electromechanical system for the transformer. Such as voltage stepup ratio, input impedance, output impedance, input power, output power, and efficiency are calculated by the equations. The optimal load resistance and the maximum efficiency for the PT will be presented in this paper. Experiments also were conducted to verify the theoretical analysis, and a good agreement was obtained.

  17. Plasma density measurement with ring-type cutoff probe

    International Nuclear Information System (INIS)

    Kim, D.W.; You, S.J.; Na, B.K.; Kim, J.H.; Shin, Y.H.; Chang, H.Y.; Oh, W.Y.

    2013-01-01

    We proposed a cutoff probe with a ring-type detection tip enclosing a bar-type radiation tip. A comparative study between a proposed ring-type cutoff (RTC) probe and a conventional bar-type cutoff (BTC) probe showed that the RTC probe solved the problem of the BTC probe, the large measurement uncertainty of the electron density in a capacitively coupled plasma source. This improved characteristics of the RTC probe might have originated from the geometrical structure of the RTC probe concerning the monopole antennae radiation. This proposed cutoff probe can be expected to expand the applicable diagnostic range and to enhance the sensitivity of the cutoff probe. - Highlights: ► A cutoff probe with a ring type detection tip is proposed. ► Comparative experiment and simulation were conducted. ► The proposed probe showed a small uncertainty of measured plasma density. ► Improved characteristics might be originated from the geometrical structure

  18. Mitral valve repair in a rheumatic population: an experience at AFIC/NIHD

    International Nuclear Information System (INIS)

    Ahmad, M.; Janjuja, A.M.; Iqbal, M.A.

    2017-01-01

    Objective: To analyze the outcome of mitral valve repair in rheumatic heart disease. Study Design: Retrospective analytical. Place and Duration of Study: Armed forces institute of cardiology/National institute of heart diseases Rawalpindi from Jan 2011 to June 2013. Material and Methods: In this retrospective study of 28 patients (15 females). The mean age was 20.2 +- 11.2 years (range, 11 to 55 years). The cause of mitral regurgitation was rheumatic in all patients, with no congenital myxomatous, infective or ischemic cases. About 68 percent patients were in New York Heart Association (NYHA) functional class III or IV. In all the cases posterior ring annuloplasty was done with flexible C- Shape rings with size ranging from 20 to 26 mm. Repairs included anterior leaflet repair with cusp shortening and resuspension (n=17), posterior leaflet repair with quardranguloplasty and transpositioning (n=6), commissuroplasty (n=2) and mixed anterior posterior leaflet repair (n=3). Results: There was no operative mortality. Follow-up was carried out for 10 months. The trivial mitral regurgitation was found in 3 cases (10.7 percent). Four (14.2 percent) patients required mitral valve replacement due to valve dysfunction. Conclusion: Mitral valve repair in rheumatic patients, with current techniques, can effectively correct functional and hemodynamic abnormalities with satisfactory results. (author)

  19. The Hi-Ring DCN Architecture

    DEFF Research Database (Denmark)

    Galili, Michael; Kamchevska, Valerija; Ding, Yunhong

    2016-01-01

    We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization......We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization...

  20. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  1. On P-coherent endomorphism rings

    Indian Academy of Sciences (India)

    A ring is called right -coherent if every principal right ideal is finitely presented. Let M R be a right -module. We study the -coherence of the endomorphism ring of M R . It is shown that is a right -coherent ring if and only if every endomorphism of M R has a pseudokernel in add M R ; S is a left -coherent ring if and ...

  2. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing; Arcak, Murat; Salama, Khaled N.

    2010-01-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  3. Periodic seasonal variation of magnets level of the STB ring

    International Nuclear Information System (INIS)

    Takahashi, Shigenobu

    2003-01-01

    The Stretcher-Booster (STB) ring, a 1.2 GeV electron synchrotron, was completed in December, 1997 at the Laboratory of Nuclear Sciences (LNS), Tohoku University. The total weight more than 400 tons were placed near the STB ring, such as concrete blocks for radiation shielding and a spectrometer magnet for nuclear physics experiments after the completion of the STB ring. Re-surveying of magnets alignment was started after 2000. Very recently a new building of an experimental hall was constructed close to the building of the STB ring for use of high energy γ-ray from the electron beam. The building will give rise the changes of magnet levels due to its seasonal distortion. The measurements of the magnet level after construction are continued as well as an expected change of the closed orbit distortion (COD) in the STB ring. The serious influence of the variation of the magnet level may be a change of the beam orbit of extracted beam in the stretcher operation. Difference of the orbit distortion reaches more than 5 mm. Correlation between the COD and the seasonal change of the magnet position is not clear at the moment. However, the machine operation and the beam diagnostics are getting better recently. Continuous surveying of the magnet level will be a useful data for a feed forward correction of the beam orbit. Future subjects and prospects are discussed on surveying. (Y. Tanaka)

  4. Status of the MIT-Bates South Hall Ring commissioning

    International Nuclear Information System (INIS)

    Flanz, J.B.; Jacobs, K.D.; McAllister, B.; Averill, R.; Bradley, S.; Carter, A.; Dow, K.; Farkondeh, M.; Ihloff, E.; Kowalski, S.

    1993-01-01

    The MIT-Bates South Hall Ring construction project is now nearly complete. At this time the Energy Compression System, the SHR Injection Line and the South Hall Ring itself are complete. The SHR Extraction Line is complete but has not been connected to the ring. Commissioning with beam of the completed beam lines has been started. The MIT-Bates South Hall Ring (SHR) is an electron storage ring used with the 1 GeV Bates electron accelerator to increase the effective duty factor and luminosity. A beam can be stored for use with an internal target, thus allowing for high duty factor, high luminosity experiments. External beams with high duty factor can be obtained using resonant extraction. The new systems associated with the SHR include the Energy Compression System (ECS), the Injection line, and the Extraction line. The authors have commissioned the ECS, the new injection line and the SHR without RF. This includes transporting beam, measuring beam phase space parameters using critical injection elements including a high voltage electrostatic septum, a fast beam kicker, and storing a beam in the SHR

  5. Beam dynamic issues in TESLA damping ring

    International Nuclear Information System (INIS)

    Shiltsev, V.

    1996-05-01

    In this paper we study general requirements on impedances of the linear collider TESLA damping ring design. Quantitative consideration is performed for 17-km long ''dog-bone'' ring. Beam dynamics in alternative options of 6.3 and 2.3-km long damping rings is briefly discussed. 5 refs., 2 tabs

  6. IAG ring test animal proteins 2014

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Pinckaers, V.G.Z.; Scholtens-Toma, I.M.J.; Prins, T.W.; Voet, van der H.; Vliege, J.J.M.

    2014-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG – International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The aim of the ring study was to provide the participants

  7. IAG ring test animal proteins 2015

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Rhee, van de N.E.; Scholtens-Toma, I.M.J.; Prins, T.W.; Vliege, J.J.M.; Pinckaers, V.G.Z.

    2015-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The organizer of the ring test was RIKILT - Wageningen UR, The

  8. IAG ring test animal proteins 2013

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Pinckaers, V.G.Z.; Scholtens-Toma, I.M.J.; Prins, T.W.; Vliege, J.J.M.

    2013-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The organizer of the the ring study was to provide the

  9. Self-gravitation in Saturn's rings

    International Nuclear Information System (INIS)

    Salo, H.; Lukkari, J.

    1982-01-01

    In a ring-shaped collisional system self-gravitation reduces the equilibrium values of the geometric and optical thickness. In Saturn's rings both effects are appreciable. The previously found discrepancy between the calculated profile and the observed profile of the rings is chiefly caused by the omission of self-gravitation. (Auth.)

  10. Real-time track-less Cherenkov ring fitting trigger system based on Graphics Processing Units

    Science.gov (United States)

    Ammendola, R.; Biagioni, A.; Chiozzi, S.; Cretaro, P.; Cotta Ramusino, A.; Di Lorenzo, S.; Fantechi, R.; Fiorini, M.; Frezza, O.; Gianoli, A.; Lamanna, G.; Lo Cicero, F.; Lonardo, A.; Martinelli, M.; Neri, I.; Paolucci, P. S.; Pastorelli, E.; Piandani, R.; Piccini, M.; Pontisso, L.; Rossetti, D.; Simula, F.; Sozzi, M.; Vicini, P.

    2017-12-01

    The parallel computing power of commercial Graphics Processing Units (GPUs) is exploited to perform real-time ring fitting at the lowest trigger level using information coming from the Ring Imaging Cherenkov (RICH) detector of the NA62 experiment at CERN. To this purpose, direct GPU communication with a custom FPGA-based board has been used to reduce the data transmission latency. The GPU-based trigger system is currently integrated in the experimental setup of the RICH detector of the NA62 experiment, in order to reconstruct ring-shaped hit patterns. The ring-fitting algorithm running on GPU is fed with raw RICH data only, with no information coming from other detectors, and is able to provide more complex trigger primitives with respect to the simple photodetector hit multiplicity, resulting in a higher selection efficiency. The performance of the system for multi-ring Cherenkov online reconstruction obtained during the NA62 physics run is presented.

  11. Bunch lengthening calculations for the SLC [Stanford Linear Collider] damping rings

    International Nuclear Information System (INIS)

    Bane, K.L.F.; Ruth, R.D.

    1989-03-01

    The problem of bunch lengthening in electron storage rings has been treated by many people, and there have been many experiments. In the typical experiment, the theory is used to determine the impedance of the ring. What has been lacking thus far, however, is a calculation of bunch lengthening that uses a carefully calculated ring impedance (or wakefield). In this paper we begin by finding the potential well distortion due to some very simple impedance models, in order to illustrate different types of bunch lengthening behavior. We then give a prescription for extending potential well calculations into the turbulent regime once the threshold is known. Then finally, using the wakefield calculated for the SLC damping rings, combined with the measured value of the threshold, we calculate bunch lengthening for the damping rings, and compare the results with the measurements. 9 refs., 6 figs

  12. Fourth-generation storage rings

    International Nuclear Information System (INIS)

    Galayda, J. N.

    1999-01-01

    It seems clear that a linac-driven free-electron laser is the accepted prototype of a fourth-generation facility. This raises two questions: can a storage ring-based light source join the fourth generation? Has the storage ring evolved to its highest level of performance as a synchrotrons light source? The answer to the second question is clearly no. The author thinks the answer to the first question is unimportant. While the concept of generations has been useful in motivating thought and effort towards new light source concepts, the variety of light sources and their performance characteristics can no longer be usefully summed up by assignment of a ''generation'' number

  13. ring mellem elever

    DEFF Research Database (Denmark)

    Davidsen, Jacob; Georgsen, Marianne

    I denne rapport tilbyder vi et indblik i det gennemførte projekt, og forfatterne har valgt nogle forhold ud, som belyses og diskuteres, mens andre ikke berøres eller diskuteres nævneværdigt i denne rapport. Det skyldes blandt andet projektets mange facetter, som dækker både læring, teknologi, pæd...

  14. ring mellem elever

    DEFF Research Database (Denmark)

    Georgsen, Marianne; Davidsen, Jacob

    2010-01-01

    I denne rapport præsenteres resultater fra følgeforskningen til projektet Læring gennem Bevægelse, som er gennemført på Søndervangskolen i Hammel i perioden august 2009 - maj 2010. Projektet er gennemført i samspil mellem lærere, it-vejleder, elever og skolens ledelse. Projektets overordnede formål...

  15. Two superconducting storage rings: ISABELLE

    International Nuclear Information System (INIS)

    Sanford, J.R.

    1978-01-01

    The general features of the design and the status of the ISABELLE storage ring project at the present time are reported. It brings up to date the results reported at the National Particle Accelerator Conference in March 1977. The most significant change since that time has been an upgrading of the energy of the overall facility, and acceptance of the project by the Department of Energy

  16. ring og it

    DEFF Research Database (Denmark)

      Antologien er et bidrag til didaktiske diskussioner om brug af f.eks. programpakker til sprogundervisning, præsentationsprogrammel og konferencesystemer på de videregående uddannelser. Antologien diskuterer ideen om, at multimediale medier og internettet kan understøtte læring, undervisning og ...... samarbejde ud fra konkrete eksempler på it-anvendelser, hvor fokus er på potentialer, barrierer og faldgruber....

  17. Carbon-14 in tree rings

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  18. Ring enhancement in recurrent gliomas

    International Nuclear Information System (INIS)

    Ogashiwa, Motohide; Takeuchi, Kazuo; Akai, Keiichiro

    1981-01-01

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

  19. Ring enhancement in recurrent gliomas

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-08-01

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

  20. [Development of a hydrogen and deuterium polarized gas target for application in storage rings]: Progress report

    International Nuclear Information System (INIS)

    Haeberli, W.

    1989-01-01

    This paper briefly discusses the following topics: the Wisconsin test facility for storage cells; results of target tests; the new UHV target test system; funding request for a new atomic beam system; and planning of storage ring experiments

  1. Evidence for Quantisation in Planetary Ring Systems

    OpenAIRE

    WAYTE, RICHARD

    2017-01-01

    Absolute radial positions of the main features in Saturn's ring system have been calculated by adapting the quantum theory of atomic spectra. Fine rings superimposed upon broad rings are found to be covered by a harmonic series of the form N α A(r)1/2, where N and A are integers. Fourier analysis of the ring system shows that the spectral amplitude fits a response profile which is characteristic of a resonant system. Rings of Jupiter, Uranus and Neptune also obey the same rules. Involvement o...

  2. Vaginal rings for delivery of HIV microbicides.

    Science.gov (United States)

    Malcolm, R Karl; Fetherston, Susan M; McCoy, Clare F; Boyd, Peter; Major, Ian

    2012-01-01

    Following the successful development of long-acting steroid-releasing vaginal ring devices for the treatment of menopausal symptoms and contraception, there is now considerable interest in applying similar devices to the controlled release of microbicides against HIV. In this review article, the vaginal ring concept is first considered within the wider context of the early advances in controlled-release technology, before describing the various types of ring device available today. The remainder of the article highlights the key developments in HIV microbicide-releasing vaginal rings, with a particular focus on the dapivirine ring that is presently in late-stage clinical testing.

  3. THE RINGS OF CHARIKLO UNDER CLOSE ENCOUNTERS WITH THE GIANT PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, R. A. N.; Sfair, R.; Winter, O. C., E-mail: ran.araujo@gmail.com, E-mail: rsfair@feg.unesp.br, E-mail: ocwinter@gmail.com [UNESP - Univ. Estadual Paulista, Grupo de Dinâmica Orbital e Planetologia, CEP 12516-410, Guaratingueta, SP (Brazil)

    2016-06-20

    The Centaur population is composed of minor bodies wandering between the giant planets that frequently perform close gravitational encounters with these planets, leading to a chaotic orbital evolution. Recently, the discovery of two well-defined narrow rings was announced around the Centaur 10199 Chariklo. The rings are assumed to be in the equatorial plane of Chariklo and to have circular orbits. The existence of a well-defined system of rings around a body in such a perturbed orbital region poses an interesting new problem. Are the rings of Chariklo stable when perturbed by close gravitational encounters with the giant planets? Our approach to address this question consisted of forward and backward numerical simulations of 729 clones of Chariklo, with similar initial orbits, for a period of 100 Myr. We found, on average, that each clone experiences during its lifetime more than 150 close encounters with the giant planets within one Hill radius of the planet in question. We identified some extreme close encounters that were able to significantly disrupt or disturb the rings of Chariklo. About 3% of the clones lose their rings and about 4% of the clones have their rings significantly disturbed. Therefore, our results show that in most cases (more than 90%), the close encounters with the giant planets do not affect the stability of the rings in Chariklo-like systems. Thus, if there is an efficient mechanism that creates the rings, then these structures may be common among these kinds of Centaurs.

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

    International Nuclear Information System (INIS)

    1989-01-01

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

  5. Leapfrogging of multiple coaxial viscous vortex rings

    International Nuclear Information System (INIS)

    Cheng, M.; Lou, J.; Lim, T. T.

    2015-01-01

    A recent theoretical study [Borisov, Kilin, and Mamaev, “The dynamics of vortex rings: Leapfrogging, choreographies and the stability problem,” Regular Chaotic Dyn. 18, 33 (2013); Borisov et al., “The dynamics of vortex rings: Leapfrogging in an ideal and viscous fluid,” Fluid Dyn. Res. 46, 031415 (2014)] shows that when three coaxial vortex rings travel in the same direction in an incompressible ideal fluid, each of the vortex rings alternately slips through (or leapfrogs) the other two ahead. Here, we use a lattice Boltzmann method to simulate viscous vortex rings with an identical initial circulation, radius, and separation distance with the aim of studying how viscous effect influences the outcomes of the leapfrogging process. For the case of two identical vortex rings, our computation shows that leapfrogging can be achieved only under certain favorable conditions, which depend on Reynolds number, vortex core size, and initial separation distance between the two rings. For the case of three coaxial vortex rings, the result differs from the inviscid model and shows that the second vortex ring always slips through the leading ring first, followed by the third ring slipping through the other two ahead. A simple physical model is proposed to explain the observed behavior

  6. Cooler Storage Ring at China Institute of Modern Physics

    CERN Document Server

    Wen-Xia, Jia; Zhan, W

    2005-01-01

    CSR, a new ion cooler-storage-ring project in China IMP, is a double ring system, and consists of a main ring (CSRm) and an experimental ring (CSRe). The two existing cyclotrons SFC (K=69) and SSC (K=450) of the Heavy Ion Research Facility in Lanzhou (HIRFL) will be used as its injector system. The heavy ion beams with the energy range of 7-30 MeV/nucleus from the HIRFL will be accumulated, cooled and accelerated to the higher energy range of 100-500 MeV/ nucleus in CSRm, and then extracted fast to produce radioactive ion beams or highly charged heavy ions. Those secondary beams will be accepted and stored or decelerated by CSRe for many internal-target experiments or high precision spectroscopy with beam cooling. On the other hand, the beams with the energy range of 100-1000MeV/ nucleus will also be extracted from CSRm by using slow extraction or fast extraction for many external-target experiments. CSR project was started in the end of 1999 and will be finished in 2006. In this paper the outline and the act...

  7. Plasma-ring, fast-opening switch

    International Nuclear Information System (INIS)

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

    1986-01-01

    The authors discuss a fast-opening switch concept based on magnetically confined plasma rings, PROS (for Plasma Ring Opening Switch). In PROS, the plasma ring, confined by Bθ /sub and B/poloidal /sub fields of a compact torus, provide a low mass, localized conduction path between coaxial electrodes. To operate the switch, driver current is passed across the electrodes through the ring, storing inductive energy in external inductance and between the electrodes on the driver side of the ring. The ring is accelerated away from the driver by the field of the driver current and passes over a load gap transferring the current to the load. The authors distinguish two configurations in PROS, straight PROS where the electrodes are coaxial cylinders, and cone PROS with conical electrodes. In straight PROS ring acceleration takes place during the inductive store period as in foil switches, but with the localized ring providing the current path. Increased performance is predicted for the cone PROS (see figure) which employs compression of the ring in the cone during the inductive store period. Here, the B/θ /sub field of the driver forces the ring towards the apex of the cone but the force is in near balance with the opposing component of the radial equilibrium force of the ring along the cone. As a result, the ring undergoes a slow, quasistatic compression limited only by resistive decay of the ring field. Slow compression allows inductive storage with low-power drivers (homopoloar, magneto cumulative generators, high C-low V capacitor banks, etc.). Near the apex of the cone, near peak compression, the ring is allowed to enter a straight coaxial section where, because of low-mass, it rapidly accelerates to high velocity and crosses the load gap

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

    Science.gov (United States)

    Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Déau, E.; Altobelli, N.

    2010-12-01

    Cassini's Composite Infrared Spectrometer has recorded over two million of spectra of Saturn's rings in the far infrared since arriving at Saturn in 2004. CIRS records far infrared radiation between 10 and 600 cm-1 ( 16.7 and 1000 μ {m} ) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn’s rings peaks in this wavelength range. Ring temperatures can be inferred from FP1 data. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and rapidly changing temperatures are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid particles can be expected to have higher thermal inertias. Ferrari et al. (2005) fit thermal inertia values of 5218 {Jm)-2 {K}-1 {s}-1/2 to their B ring data and 6412 {Jm)-2 {K}-1 {s}-1/2 to their C ring data. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The rings’ thermal budget is dominated by its absorption of solar radiation. As a result, ring particles abruptly cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  9. Einstein Ring in Distant Universe

    Science.gov (United States)

    2005-06-01

    Using ESO's Very Large Telescope, Rémi Cabanac and his European colleagues have discovered an amazing cosmic mirage, known to scientists as an Einstein Ring. This cosmic mirage, dubbed FOR J0332-3557, is seen towards the southern constellation Fornax (the Furnace), and is remarkable on at least two counts. First, it is a bright, almost complete Einstein ring. Second, it is the farthest ever found. ESO PR Photo 20a/05 ESO PR Photo 20a/05 Deep Image of a Region in Fornax (FORS/VLT) [Preview - JPEG: 400 x 434 pix - 60k] [Normal - JPEG: 800 x 867 pix - 276k] [Full Res - JPEG: 1859 x 2015 pix - 3.8M] ESO PR Photo 20b/05 ESO PR Photo 20b/05 Zoom-in on the Newly Found Einstein Ring (FORS/VLT) [Preview - JPEG: 400 x 575 pix - 168k] [Normal - JPEG: 630 x 906 pix - 880k] Caption: ESO PR Photo 20a/05 is a composite image taken in two bands (B and R) with VLT/FORS1 of a small portion of the sky (field-of-view 7x7' or 1/15th of the area of the full moon). The faintest object seen in the image has a magnitude 26, that is, it is 100 million times fainter than what can be observed with the unaided eye. The bright elliptical galaxy on the lower-left quadrant is a dwarf galaxy part of a large nearby cluster in the Fornax constellation. As for all deep images of the sky, this field shows a variety of objects, the brightest ponctual sources being stars from our Galaxy. By far the field is dominated by thousands of faint background galaxies the colours of which are related to the age of their dominant stellar population, their dust content and their distance. The newly found Einstein ring is visible in the top right part of the image. ESO PR Photo 20b/05 zooms-in on the position of the newly found cosmic mirage. ESO PR Photo 20c/05 ESO PR Photo 20c/05 Einstein Ring in Distant Universe (FORS/VLT) [Preview - JPEG: 400 x 584 pix - 104k] [Normal - JPEG: 800 x 1168 pix - 292k] [Full Res - JPEG: 1502 x 2192 pix - 684k] Caption of ESO PR Photo 20c/05: The left image is magnified and centred

  10. Prevalent hallucinations during medical internships: phantom vibration and ringing syndromes.

    Directory of Open Access Journals (Sweden)

    Yu-Hsuan Lin

    Full Text Available BACKGROUND: Phantom vibration syndrome is a type of hallucination reported among mobile phone users in the general population. Another similar perception, phantom ringing syndrome, has not been previously described in the medical literature. METHODS: A prospective longitudinal study of 74 medical interns (46 males, 28 females; mean age, 24.8±1.2 years was conducted using repeated investigations of the prevalence and associated factors of phantom vibration and ringing. The accompanying symptoms of anxiety and depression were evaluated with the Beck Anxiety and Depression Inventories before the internship began, and again at the third, sixth, and twelfth internship months, and two weeks after the internship ended. RESULTS: The baseline prevalence of phantom vibration was 78.1%, which increased to 95.9% and 93.2% in the third and sixth internship months. The prevalence returned to 80.8% at the twelfth month and decreased to 50.0% 2 weeks after the internship ended. The baseline prevalence of phantom ringing was 27.4%, which increased to 84.9%, 87.7%, and 86.3% in the third, sixth, and twelfth internship months, respectively. This returned to 54.2% two weeks after the internship ended. The anxiety and depression scores also increased during the internship, and returned to baseline two weeks after the internship. There was no significant correlation between phantom vibration/ringing and symptoms of anxiety or depression. The incidence of both phantom vibration and ringing syndromes significantly increased during the internship, and subsequent recovery. CONCLUSION: This study suggests that phantom vibration and ringing might be entities that are independent of anxiety or depression during evaluation of stress-associated experiences during medical internships.

  11. TRISTAN experiment

    International Nuclear Information System (INIS)

    Iwata, Seigi

    1994-01-01

    Any successor to PETRA and PEP colliders was expected to extend the energy range to the region where the weak interaction effect becomes sizable in annihilation process. The aim was to reach the level, at which the all round study of the standard model can be performed in a clean system of e + e - collision. Also it was aimed to explore the energy region where top quark pair production is likely. Considering the available site for accelerator construction and the expected size of the electroweak interference effect, the target energy was set at 60 GeV at the lowest. TRISTAN-1 experiment is a big initial step in the long range physics program. The laboratory established the plan to move on to TRISTAN-2 (B Factory) project. The TRISTAN accelerator including the main storage ring, the time sequence of storage ring operation, three experimental groups of AMY, TOPAZ and VENUS, and so on are explained. The experiments on basic annihilation process, the search for new particles, the electroweak interaction, QCD studies and so on are reported. The optimum TRISTAN ring was estimated as 3 km in diameter, but the largest possible size in the site was 1/3 of that. Hard decision was made to equip the ring with unusually many accelerating RF cavities and to apply superconducting technology. (K.I.)

  12. Proton accumulator ring injection studies

    International Nuclear Information System (INIS)

    Cooper, R.K.; Neil, V.K.

    1977-01-01

    Protons may be created in an accelerator or storage ring by stripping electrons from neutral hydrogen atoms that have been injected into the machine. Because Liouville's theorem is violated by this type of injection, particles may be continually injected into a region of phase space that is already populated, and the density in that region increases with time. A computational investigation was made of the evolution of the distribution of particles in longitudinal phase space during such an injection process for a storage ring operating below the transition energy. In one calculation, an rf cavity is present in the ring and particles are injected into the stable phase region once each revolution. The purpose of this calculation is to determine the rf voltage necessary to overcome the longitudinal self-forces and contain the particles within the region of stable phase. In a second calculation, the rf is turned off, so that there is spreading in azimuth of the injected particles (i.e., de-bunching). The de-bunching occurs because of the initial energy spread and the action of the self-forces. One purpose of the calculation is to determine the total energy spread after a given number of revolutions. Another purpose is to elucidate the effect of finite resistance in the vacuum tank walls. For sufficiently high current, the finite resistance can cause bunching of a beam that is initially uniform in azimuth. Therefore it might be expected that the finite resistance would inhibit or prevent de-bunching once the number of particles injected reaches some threshold, and that this threshold would depend upon the energy spread in the beam

  13. Interaction of ring dark solitons with ring impurities in Bose-Einstein condensates

    International Nuclear Information System (INIS)

    Xue Jukui

    2005-01-01

    The interaction of ring dark solitons/vortexes with the ring-shaped repulsive and attractive impurities in two-dimensional Bose-Einstein condensates is investigated numerically. Very rich interaction phenomena are obtained, i.e., not only the interaction between the ring soliton and the impurity, but also the interaction between vortexes and the impurity. The interaction characters, i.e., snaking of ring soliton, quasitrapping or reflection of ring soliton and vortexes by the impurity, strongly depend on initial ring soliton velocity, impurity strength, initial position of ring soliton and impurity. The numerical results also reveal that ring dark solitons/vortexes can be trapped and dragged by an adiabatically moving attractive ring impurity

  14. Polyurethane Foams with Pyrimidine Rings

    Directory of Open Access Journals (Sweden)

    Kania Ewelina

    2014-09-01

    Full Text Available Oligoetherols based on pyrimidine ring were obtained upon reaction of barbituric acid with glycidol and alkylene carbonates. These oligoetherols were then used to obtain polyurethane foams in the reaction of oligoetherols with isocyanates and water. The protocol of foam synthesis was optimized by the choice of proper kind of oligoetherol and synthetic composition. The thermal resistance was studied by dynamic and static methods with concomitant monitoring of compressive strength. The polyurethane foams have similar physical properties as the classic ones except their enhanced thermal resistance. They stand long-time heating even at 200°C. Moreover thermal exposition of foams results generally in increase of their compressive strength.

  15. Longitudinal dynamics in storage rings

    International Nuclear Information System (INIS)

    Colton, E.P.

    1986-01-01

    The single-particle equations of motion are derived for charged particles in a storage ring. Longitudinal space charge is included in the potential assuming an infinitely conducting circular beam pipe with a distributed inductance. The framework uses Hamilton's equations with the canonical variables phi and W. The Twiss parameters for longitudinal motion are also defined for the small amplitude synchrotron oscillations. The space-charge Hamiltonian is calculated for both parabolic bunches and ''matched'' bunches. A brief analysis including second-harmonic rf contributions is also given. The final sections supply calculations of dynamical quantities and particle simulations with the space-charge effects neglected

  16. Ring with changeable radiation dosimeter

    International Nuclear Information System (INIS)

    Collica, C.; Epifano, L.; Farella, R.

    1976-01-01

    A ring for housing a disc of radiation measuring material is described comprising a band having a circular shape and a housing integral with the band. The housing comprises a hollow cylindrical section substantially normal to the band surface and terminating in an inwardly disposed annular flange which defines a substantially circular aperture. In a preferred embodiment of the invention a retaining protrusion formed on the inside of the cylindrical section and spaced from the annular flange is provided to retain a plurality of discs mounted in the housing in layered fashion

  17. Ring magnet firing angle control

    International Nuclear Information System (INIS)

    Knott, M.J.; Lewis, L.G.; Rabe, H.H.

    1975-01-01

    A device is provided for controlling the firing angles of thyratrons (rectifiers) in a ring magnet power supply. A phase lock loop develops a smooth ac signal of frequency equal to and in phase with the frequency of the voltage wave developed by the main generator of the power supply. A counter that counts from zero to a particular number each cycle of the main generator voltage wave is synchronized with the smooth AC signal of the phase lock loop. Gates compare the number in the counter with predetermined desired firing angles for each thyratron and with coincidence the proper thyratron is fired at the predetermined firing angle

  18. Interaction of Vortex Ring with Cutting Plate

    Science.gov (United States)

    Musta, Mustafa

    2015-11-01

    The interaction of a vortex ring impinging on a thin cutting plate was made experimentally using Volumetric 3-component Velocitmetry (v3v) technique. The vortex rings were generated with piston-cylinder vortex ring generator using piston stroke-to-diameter ratios and Re at 2-3 and 1500 - 3000, respectively. The cutting of vortex rings below center line leads to the formation of secondary vortices on each side of the plate which is look like two vortex rings, and a third vortex ring propagates further downstream in the direction of the initial vortex ring, which is previously showed by flow visualization study of Weigand (1993) and called ``trifurcation''. Trifurcation is very sensitive to the initial Reynolds number and the position of the plate with respect to the vortex ring generator pipe. The present work seeks more detailed investigation on the trifurcation using V3V technique. Conditions for the formation of trifurcation is analyzed and compared with Weigand (1993). The formed secondary vortex rings and the propagation of initial vortex ring in the downstream of the plate are analyzed by calculating their circulation, energy and trajectories.

  19. Internal target effects in ion storage rings with beam cooling

    International Nuclear Information System (INIS)

    Gostishchev, Vitaly

    2008-06-01

    The accurate description of internal target effects is important for the prediction of operation conditions which are required for experiments in the planned storage rings of the FAIR facility. The BETACOOL code developed by the Dubna group has been used to evaluate beam dynamics in ion storage rings, where electron cooling in combination with an internal target is applied. Systematic benchmarking experiments of this code were carried out at the ESR storage ring at GSI. A mode with vanishing dispersion in the target position was applied to evaluate the influence of the dispersion function on the parameters when the target is heating the beam. The influence of the internal target on the beam parameters is demonstrated in the present work. A comparison of experimental results with simple models describing the energy loss of the beam particles in the target as well as with more sophisticated simulations with the BETACOOL code is given. In order to study the conditions which can be achieved in the proposed experiments the simulation results were quantitatively compared with experimental results and simulations for the ESR. The results of this comparison are discussed in the present thesis. BETACOOL simulations of target effects were performed for the NESR and the HESR of the future FAIR facility in order to predict the beam parameters for the planned experiments. (orig.)

  20. Internal target effects in ion storage rings with beam cooling

    Energy Technology Data Exchange (ETDEWEB)

    Gostishchev, Vitaly

    2008-06-15

    The accurate description of internal target effects is important for the prediction of operation conditions which are required for experiments in the planned storage rings of the FAIR facility. The BETACOOL code developed by the Dubna group has been used to evaluate beam dynamics in ion storage rings, where electron cooling in combination with an internal target is applied. Systematic benchmarking experiments of this code were carried out at the ESR storage ring at GSI. A mode with vanishing dispersion in the target position was applied to evaluate the influence of the dispersion function on the parameters when the target is heating the beam. The influence of the internal target on the beam parameters is demonstrated in the present work. A comparison of experimental results with simple models describing the energy loss of the beam particles in the target as well as with more sophisticated simulations with the BETACOOL code is given. In order to study the conditions which can be achieved in the proposed experiments the simulation results were quantitatively compared with experimental results and simulations for the ESR. The results of this comparison are discussed in the present thesis. BETACOOL simulations of target effects were performed for the NESR and the HESR of the future FAIR facility in order to predict the beam parameters for the planned experiments. (orig.)

  1. Dynamics of the evaporative dewetting of a volatile liquid film confined within a circular ring.

    Science.gov (United States)

    Sun, Wei; Yang, Fuqian

    2015-04-07

    The dewetting dynamics of a toluene film confined within a copper ring on a deformable PMMA film is studied. The toluene film experiences evaporation and dewetting, which leads to the formation of a circular contact line around the center of the copper ring. The contact line recedes smoothly toward the copper ring at a constant velocity until reaching a dynamic "stick" state to form the first circular polymer ridge. The average receding velocity is found to be dependent on the dimensions of the copper ring (the copper ring diameter and the cross-sectional diameter of the copper wire) and the thickness of the PMMA films. A model is presented to qualitatively explain the evaporative dewetting phenomenon.

  2. Simulation of the Initial 3-D Instability of an Impacting Drop Vortex Ring

    DEFF Research Database (Denmark)

    Sigurdson, Lorenz; Wiwchar, Justin; Walther, Jens Honore

    2013-01-01

    , a Rayleigh centrifugal instability, or a vortex breakdown-type instability. Simulations which simply have a perturbed solitary ring result in an instability similar to that seen experimentally. Waviness of the core which would be expected from a Widnall instability is not visible. Adding an opposite......-signed secondary vortex ring or an image vortex ring to the initial conditions, to trigger a Rayleigh or breakdown respectively, does not appear to significantly change the instability from what is seen with a solitary ring. This suggests that a Rayleigh or vortex breakdown-type instability are not likely at work......Computational vortex particle method simulations of a perturbed vortex ring are performed to recreate and understand the instability seen in impacting water drop experiments. Three fundamentally different initial vorticity distributions are used to attempt to trigger a Widnall instability...

  3. A ring image Cerenkov detector for the CERN Omega Spectrometer

    International Nuclear Information System (INIS)

    Davenport, M.; Deol, R.S.; Flower, P.S.

    1983-05-01

    A development program has been undertaken to produce a large ring image Cerenkov detector (RICH) for use at the CERN Omega Spectrometer. A prototype Cerenkov counter has been constructed and successfully operated in a high energy particle beam, Cerenkov rings having been observed in an experimental time projection chamber (TPC) using the photoionising agents Triethylamine (TEA) and Tetrakis (dimethylamine) ethylene (TMAE). Systematic measurements have been made of the optical properties of window materials and reflecting surfaces in the vacuum ultraviolet region. Results of these tests are presented, and the design of the large detector based on these experiences together with Monte Carlo simulations of the events expected in the WA69 experiment, is discussed. (author)

  4. Dynamical Evolution of Ring-Satellite Systems

    Science.gov (United States)

    Ohtsuki, Keiji

    2005-01-01

    The goal of this research was to understand dynamical processes related to the evolution of size distribution of particles in planetary rings and application of theoretical results to explain features in the present rings of giant planets. We studied velocity evolution and accretion rates of ring particles in the Roche zone. We developed a new numerical code for the evolution of ring particle size distribution, which takes into account the above results for particle velocity evolution and accretion rates. We also studied radial diffusion rate of ring particles due to inelastic collisions and gravitational encounters. Many of these results can be also applied to dynamical evolution of a planetesimal disk. Finally, we studied rotation rates of moonlets and particles in planetary rings, which would influence the accretional evolution of these bodies. We describe our key accomplishments during the past three years in more detail in the following.

  5. Foundations of commutative rings and their modules

    CERN Document Server

    Wang, Fanggui

    2016-01-01

    This book provides an introduction to the basics and recent developments of commutative algebra. A glance at the contents of the first five chapters shows that the topics covered are ones that usually are included in any commutative algebra text. However, the contents of this book differ significantly from most commutative algebra texts: namely, its treatment of the Dedekind–Mertens formula, the (small) finitistic dimension of a ring, Gorenstein rings, valuation overrings and the valuative dimension, and Nagata rings. Going further, Chapter 6 presents w-modules over commutative rings as they can be most commonly used by torsion theory and multiplicative ideal theory. Chapter 7 deals with multiplicative ideal theory over integral domains. Chapter 8 collects various results of the pullbacks, especially Milnor squares and D+M constructions, which are probably the most important example-generating machines. In Chapter 9, coherent rings with finite weak global dimensions are probed, and the local ring of weak gl...

  6. A first course in noncommutative rings

    CERN Document Server

    Lam, T Y

    2001-01-01

    A First Course in Noncommutative Rings, an outgrowth of the author's lectures at the University of California at Berkeley, is intended as a textbook for a one-semester course in basic ring theory. The material covered includes the Wedderburn-Artin theory of semisimple rings, Jacobson's theory of the radical, representation theory of groups and algebras, prime and semiprime rings, local and semilocal rings, perfect and semiperfect rings, etc. By aiming the level of writing at the novice rather than the connoisseur and by stressing th the role of examples and motivation, the author has produced a text that is suitable not only for use in a graduate course, but also for self- study in the subject by interested graduate students. More than 400 exercises testing the understanding of the general theory in the text are included in this new edition.

  7. Report of the eRHIC Ring-Ring Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer, E. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brennan, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Palmer, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Parker, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Willeke, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-10-13

    This report evaluates the ring-ring option for eRHIC as a lower risk alternative to the linac-ring option. The reduced risk goes along with a reduced initial luminosity performance. However, a luminosity upgrade path is kept open. This upgrade path consists of two branches, with the ultimate upgrade being either a ring-ring or a linac-ring scheme. The linac-ring upgrade could be almost identical to the proposed linac-ring scheme, which is based on an ERL in the RHIC tunnel. This linac-ring version has been studied in great detail over the past ten years, and its significant risks are known. On the other hand, no detailed work on an ultimate performance ring-ring scenario has been performed yet, other than the development of a consistent parameter set. Pursuing the ring-ring upgrade path introduces high risks and requires significant design work that is beyond the scope of this report.

  8. A muon storage ring for neutrino beams

    International Nuclear Information System (INIS)

    Lee, W.; Neuffer, D.

    1988-01-01

    A muon storage ring can provide electron and muon neutrino beams of precisely knowable flux. Constraints on muon collection and storage-ring design are discussed. Sample muon storage rings are presented and muon and neutrino intensities are estimated. Experimental use of the ν-beams, detector properties, and possible variations are described. Future directions for conceptual designs are outlined. 11 refs., 4 figs., 3 tabs

  9. Saturn’s ring temperatures at equinox

    Science.gov (United States)

    Spilker, Linda J.; Ferrari, C.; Morishima, R.

    2013-10-01

    Modeling the thermal emission of Saturn's rings is challenging due to the numerous heating sources as well as the structural properties of the disk and of the particles that are closely related. At equinox, however, the main rings are externally heated by Saturn alone and the problem is somewhat simplified. We test the abilities of our current models to reproduce the temperatures observed with the Cassini CIRS instrument around equinox in August 2009. A simple semi-analytic model which includes mutual shadowing effects can mostly explain the radial profile of the equinox ring temperatures, except the model predicts lower temperatures than those observed for the A ring. The temperature variation at a given saturnocentric radius is primarily caused by observational geometry variations relative to Saturn. The observed temperature increases with decreasing Saturn-ring-observer angle. In addition, we found evidence that the leading hemispheres of particles are warmer than the trailing hemispheres at least for the C ring and probably for the A and B rings as well. This is explained if some fraction of particles has spin rates lower than the synchronous rotation rate as predicted by N-body simulations. The spin model for a monolayer ring (Ferrari, C., Leyrat, C., 2006, Astron. Astrophys. 447, 745-760) can fit the temperature variations with spacecraft longitude observed in the C ring with currently known thermal properties and a mixing of slow and fast rotators. The multilayer model (Morishima, R., Salo, H., Ohtsuki, K., 2009, Icarus 201, 634-654) can reproduce the temperatures of the B and C rings but gives A ring temperatures that are significantly lower than those observed as does the simple semi-analytic model. More advanced models which take into account self-gravity wakes may explain the A ring temperature behavior.

  10. Ring recognition in the CBM RICH detector

    International Nuclear Information System (INIS)

    Lebedev, S.; Ososkov, G.; Hoehne, C.

    2007-01-01

    Two algorithms of ring recognition, a standalone ring finder (using only RICH information) and an algorithm based on the information from vertex tracks are described. The fake ring problem and its solution using a set of two-dimensional cuts or an artificial neural network are discussed. Results of a comparative study are given. All developed algorithms were tested on large statistics of simulated events and were then included into the CBM framework for common use

  11. On Semiprime Noetherian PI-Rings

    OpenAIRE

    Chiba, Katsuo

    2000-01-01

    Let R be a semiprime Noetherian PI-ring and Q(R) the semisimple Artinian ring of fractions of R. We shall prove the following conditions are equivalent: (1) the Krull dimention of R is at most one, (2) Any ring between R and Q(R) is again right Noetherian, (3) Let a, b be central regular elements of Q(R). Then the subring R + aR[b] of Q(R) is right Noetherian.

  12. The fluid systems for the SLD Cherenkov ring imaging detector

    International Nuclear Information System (INIS)

    Abe, K.; Hasegawa, K.; Hasegawa, Y.; Iwasaki, Y.; Suekane, F.; Yuta, H.; Baird, K.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Word, G.; Bean, A.; Caldwell, D.O.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Yellin, S.; Ben-David, R.; Manly, S.; Snyder, J.; Turk, J.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Schneider, M.; Williams, D.A.; Coller, J.; Shank, J.T.; Whitaker, J.S.; d'Oliveira, A.; Johnson, R.A.; Martinez, J.; Nussbaum, M.; Santha, A.K.S.; Sokoloff, M.D.; Stockdale, I.; Wilson, R.J.

    1992-10-01

    We describe the design and operation of the fluid delivery, monitor and control systems for the SLD barrel Cherenkov Ring Imaging Detector (CRID). The systems deliver drift gas (C 2 H 6 + TMAE), radiator gas (C 5 F 12 + N 2 ) and radiator liquid (C 6 F 14 ). Measured critical quantities such as electron lifetime in the drift gas and ultra-violet (UV) transparencies of the radiator fluids, together with the operational experience, are also reported

  13. Construction and testing of the SLD Cerenkov ring imaging detector

    International Nuclear Information System (INIS)

    Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Williams, D.A.; Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H.

    1990-01-01

    The authors report on the construction of the Cherenkov Ring Imaging Detector (CRID) for the SLD experiment at the SLAC Linear Collider and the testing of its components. The authors include results from testing the drift boxes, liquid radiator trays, and mirrors for the barrel CRID. The authors also discuss development of the support systems essential for the operation of the CRID: gas and liquid recirculator systems and monitoring

  14. An induction accelerator for the Heidelberg Test Storage Ring TSR

    International Nuclear Information System (INIS)

    Ellert, C.; Habs, D.; Music, M.; Schwalm, D.; Wolf, A.; Jaeschke, E.; Kambara, T.; Sigray, P.

    1992-01-01

    An induction accelerator has been installed in the heavy ion test storage ring TSR in Heidelberg. It allows for constant acceleration or deceleration of stored coasting ion beams without affecting their velocity profile and is well suited for ion beam manipulation in cooling experiments and for measurements of velocity dependent cooling forces. The design and operation of the device and first applications to laser cooling and to measurements of laser and electron cooling forces are described. (orig.)

  15. Imaging electron wave functions inside open quantum rings.

    Science.gov (United States)

    Martins, F; Hackens, B; Pala, M G; Ouisse, T; Sellier, H; Wallart, X; Bollaert, S; Cappy, A; Chevrier, J; Bayot, V; Huant, S

    2007-09-28

    Combining scanning gate microscopy (SGM) experiments and simulations, we demonstrate low temperature imaging of the electron probability density |Psi|(2)(x,y) in embedded mesoscopic quantum rings. The tip-induced conductance modulations share the same temperature dependence as the Aharonov-Bohm effect, indicating that they originate from electron wave function interferences. Simulations of both |Psi|(2)(x,y) and SGM conductance maps reproduce the main experimental observations and link fringes in SGM images to |Psi|(2)(x,y).

  16. Laser-Cooled Ions and Atoms in a Storage Ring

    International Nuclear Information System (INIS)

    Kleinert, J.; Hannemann, S.; Eike, B.; Eisenbarth, U.; Grieser, M.; Grimm, R.; Gwinner, G.; Karpuk, S.; Saathoff, G.; Schramm, U.; Schwalm, D.; Weidemueller, M.

    2003-01-01

    We review recent experiments at the Heidelberg Test Storage Ring which apply advanced laser cooling techniques to stored ion beams. Very high phase-space densities are achieved by three-dimensional laser cooling of a coasting 9 Be + beam at 7.3 MeV. Laser-cooled, trapped Cs atoms are used as an ultracold precision target for the study of ion-atom interactions with a 74 MeV beam of 12 C 6+ ions.

  17. Multiple Coulomb ordered strings of ions in a storage ring

    International Nuclear Information System (INIS)

    Hasse, Rainer W.

    2002-01-01

    We explain that the anomalous frequency shifts of very close masses measured in the high precision mass measurement experiments in the ESR storage ring result from the locking of Coulomb interacting strings of ions. Here two concentric strings which run horizontally close to each other for many revolutions are captured into a single string if their thermal clouds overlap. They give up their identity and lock into an average frequency

  18. Physics and technology of superthin internal targets in storage rings

    International Nuclear Information System (INIS)

    Popov, S.G.

    1989-01-01

    The new generation of accelerators for coincidence electronuclear investigations is discussed. The luminosity and beam parameters are calculated for an electron storage ring with an internal target operating in the superthin regime. The advantages and disadvantages in comparison with conventional operation using an external beam and target are described. The intermediate results for 2 GeV electron scattering on polarized internal deuterium target are given (joint Novosibirsk-Argonne experiment). 32 refs.; 5 figs

  19. Simulation investigation of storage ring optical klystron spontaneous emission

    International Nuclear Information System (INIS)

    Xu Hongliang; Liu Jinying; He Duohui; Diao Caozheng; Jia Qika; Sun Baogen

    1998-01-01

    The spontaneous emission of TOK in Hefei storage ring was simulated with Monte Carlo method. Section one described the structure of the permanent magnet TOK and the magnet field of TOK. Section two simulated results, and simulated results illustrated how the energy spread and emittance of electron beam impose on the spectrum of spontaneous emission. And with help of simulated results, the causes of small modulation factor which was measured by experiment was discussed

  20. A Bell inequality for a class of multilocal ring networks

    Science.gov (United States)

    Frey, Michael

    2017-11-01

    Quantum networks with independent sources of entanglement (hidden variables) and nodes that execute joint quantum measurements can create strong quantum correlations spanning the breadth of the network. Understanding of these correlations has to the present been limited to standard Bell experiments with one source of shared randomness, bilocal arrangements having two local sources of shared randomness, and multilocal networks with tree topologies. We introduce here a class of quantum networks with ring topologies comprised of subsystems each with its own internally shared source of randomness. We prove a Bell inequality for these networks, and to demonstrate violations of this inequality, we focus on ring networks with three-qubit subsystems. Three qubits are capable of two non-equivalent types of entanglement, GHZ and W-type. For rings of any number N of three-qubit subsystems, our inequality is violated when the subsystems are each internally GHZ-entangled. This violation is consistently stronger when N is even. This quantitative even-odd difference for GHZ entanglement becomes extreme in the case of W-type entanglement. When the ring size N is even, the presence of W-type entanglement is successfully detected; when N is odd, the inequality consistently fails to detect its presence.

  1. Undulator sources at a 8 GeV storage ring

    International Nuclear Information System (INIS)

    Harami, Taikan.

    1989-06-01

    The use of undulators plays an important role as a high brilliance sources of synchrotron photon at a facility having an electron (or positron) storage ring. This paper describes the characteristics, tunability from gap variation and brilliance of synchrotron photon from undulators at a 8 GeV storage ring. The numerical studies show the following results. (1) Undulators for a 8 GeV storage ring can cover the first harmonic photon energy range from about 0.3 to 30 keV and the third harmonic photon from 0.85 to 70 keV. (2) The brilliance of undulator can be expected to be the order of 10 21 photons/(sec mm 2 mrad 2 0.1% band width mA), without size and angular spread in the electron beam (diffraction limit). (3) The peak brilliance has a broad maximum as a function of β function of the lattice and is shown to be practically independent on the β function. The peak brilliance is calculated to be the order of 10 16 photons/(sec mm 2 mrad 2 0.1% band width mA) at the electron beam emittance of 5 x 10 -9 m·rad (undulator length 2 m). (4) The nuclei of 57 Fe, 119 Sn and 238 U are expected to be the candidates for the Moessbauer scattering experiment using synchrotron photon from a 8 GeV storage ring. (author)

  2. Integrated polymer micro-ring resonators for optical sensing applications

    Science.gov (United States)

    Girault, Pauline; Lorrain, Nathalie; Poffo, Luiz; Guendouz, Mohammed; Lemaitre, Jonathan; Carré, Christiane; Gadonna, Michel; Bosc, Dominique; Vignaud, Guillaume

    2015-03-01

    Micro-resonators (MR) have become a key element for integrated optical sensors due to their integration capability and their easy fabrication with low cost polymer materials. Nowadays, there is a growing need on MRs as highly sensitive and selective functions especially in the areas of food and health. The context of this work is to implement and study integrated micro-ring resonators devoted to sensing applications. They are fabricated by processing SU8 polymer as core layer and PMATRIFE polymer as lower cladding layer. The refractive index of the polymers and of the waveguide structure as a function of the wavelength is presented. Using these results, a theoretical study of the coupling between ring and straight waveguides has been undertaken in order to define the MR design. Sub-micronic gaps of 0.5 μm to 1 μm between the ring and the straight waveguides have been successfully achieved with UV (i-lines) photolithography. Different superstrates such as air, water, and aqueous solutions with glucose at different concentrations have been studied. First results show a good normalized transmission contrast of 0.98, a resonator quality factor around 1.5 × 104 corresponding to a coupling ratio of 14.7%, and ring propagation losses around 5 dB/cm. Preliminary sensing experiments have been performed for different concentrations of glucose; a sensitivity of 115 ± 8 nm/RIU at 1550 nm has been obtained with this couple of polymers.

  3. 3-D studies of the formation and stability of strong ion rings

    International Nuclear Information System (INIS)

    Omelchenko, Yu.A.; Sudan, R.N.

    1996-01-01

    Complex 3-D simulations were conducted in support of the on-going experimental program, FIREX( (Field-Reversed Ion Ring Experiment) launched at the Cornell University to produce an ion ring magnetic field-reversed configuration by injecting an intense annular proton beam across a plasma-filled magnetic cusp region into a neutral gas immersed in a ramped solenoidal magnetic field. Previous axisymmetric PIC simulations performed with the FIRE code have demonstrated that strong ion rings (with a self-magnetic field large enough to reverse the applied field on axis) can be created using this technique on the equipment designed and assembled at Cornell. A new parallel object-oriented 3-D hybrid PIC code FLAME has been created to study questions of extreme importance to the success of the FIREX program, namely, the 3-D injection of a powerful ion beam into a strongly magnetized plasma, formation of a field-reversed ring, and the stability and equilibrium of such rings to toroidal perturbations. Using FLAME, the stability was studied of the ring formation during the injection phase and at later times when the ring is virtually stopped and the applied magnetic field is nearly reversed. The simulations revealed the effect of toroidal aberrations in the axially ramped magnetic field on the ion ring formation. (author). 4 figs., 4 refs

  4. 3-D studies of the formation and stability of strong ion rings

    Energy Technology Data Exchange (ETDEWEB)

    Omelchenko, Yu A; Sudan, R N [Cornell Univ., Ithaca, NY (United States). Laboratory of Plasma Studies

    1997-12-31

    Complex 3-D simulations were conducted in support of the on-going experimental program, FIREX( (Field-Reversed Ion Ring Experiment) launched at the Cornell University to produce an ion ring magnetic field-reversed configuration by injecting an intense annular proton beam across a plasma-filled magnetic cusp region into a neutral gas immersed in a ramped solenoidal magnetic field. Previous axisymmetric PIC simulations performed with the FIRE code have demonstrated that strong ion rings (with a self-magnetic field large enough to reverse the applied field on axis) can be created using this technique on the equipment designed and assembled at Cornell. A new parallel object-oriented 3-D hybrid PIC code FLAME has been created to study questions of extreme importance to the success of the FIREX program, namely, the 3-D injection of a powerful ion beam into a strongly magnetized plasma, formation of a field-reversed ring, and the stability and equilibrium of such rings to toroidal perturbations. Using FLAME, the stability was studied of the ring formation during the injection phase and at later times when the ring is virtually stopped and the applied magnetic field is nearly reversed. The simulations revealed the effect of toroidal aberrations in the axially ramped magnetic field on the ion ring formation. (author). 4 figs., 4 refs.

  5. Design of Piston Ring Friction Tester Apparatus

    DEFF Research Database (Denmark)

    Klit, Peder

    2006-01-01

    One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing the frictio......One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing...... the frictional behavior of a piston ring correctly is knowledge about the amount of lubricant present. For piston rings the external load may be established by measuring the pressure distribution, i.e. the pressure drop in the piston ring package. Speed and temperature may also be established. The amount...... available is reflected in the friction absorbed in the bearing. The following properties will be measured: Oil fillm thickness - along liner (axial variation), oil film thickness - along piston ring (circumferential variation), piston tilt, temperature of piston rings and liner, pressure at piston lands...

  6. Multiplication modules over non-commutative rings

    International Nuclear Information System (INIS)

    Tuganbaev, A A

    2003-01-01

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

  7. Influence of topology in a quantum ring

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  8. Topological matter, integrable models and fusion rings

    International Nuclear Information System (INIS)

    Nemeschansky, D.; Warner, N.P.

    1992-01-01

    We show how topological G k /G k models can be embedded into the topological matter models that are obtained by perturbing the twisted N = 2 supersymmetric, hermitian symmetric, coset models. In particular, this leads to an embedding of the fusion ring of G as a sub-ring of the perturbed, chiral primary ring. The perturbation of the twisted N = 2 model that leads to the fusion ring is also shown to lead to an integrable N = 2 supersymmetric field theory when the untwisted N = 2 superconformal field theory is perturbed by the same operator and its hermitian conjugate. (orig.)

  9. Corneal iron ring after hyperopic photorefractive keratectomy.

    Science.gov (United States)

    Bilgihan, K; Akata, F; Gürelik, G; Adigüzel, U; Akpinar, M; Hasanreisoğlu, B

    1999-05-01

    To report the incidence and course of corneal iron deposition after hyperopic photorefractive keratectomy (PRK). Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. Between January 1995 and December 1997, 62 eyes had PRK to correct hyperopia. Nine eyes developed corneal iron ring 5 to 8 months (mean 6.25 months +/- 1.3 [SD]) after PRK for hyperopia. The rings persisted during the mean follow-up of 19 +/- 11.09 months. The ring-shaped iron deposition after PRK for hyperopia must be differentiated from the Fleischer ring. Our results suggest that the slitlamp findings of peripheral corneal iron deposition in hyperopic PRK patients correlate with achieved correction.

  10. Fifth Interim Status Report: Model 9975 PCV O-Ring Fixture Long-Term Leak Performance

    International Nuclear Information System (INIS)

    Daugherty, W.; Hoffman, E.

    2010-01-01

    A series of experiments to monitor the aging performance of Viton reg. GLT O-rings used in the Model 9975 package has been ongoing for six years at the Savannah River National Laboratory. Sixty-seven mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 F. They were leak-tested initially and have been tested at nominal six month intervals to determine if they meet the criterion of leaktightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 F. High temperature aging continues for 36 GLT O-ring fixtures at 200--350 F. Room temperature leak test failures have been experienced in 5 of the GLT O-ring fixtures aging at 300 and 350 F, and in all 3 of the GLT O-ring fixtures aging at higher temperatures. No failures have yet been observed in GLT O-ring fixtures aging at 200 F for 30--48 months, which is still bounding to O-ring temperatures during storage in KAMS. High temperature aging continues for 6 GLT-S O-ring fixtures at 200--300 F. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 F. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 or 300 F for 19 months. For O-ring fixtures that have failed the room temperature leak test and been disassembled, the O-rings displayed a compression set ranging from 51--95%. This is significantly greater than seen to date for packages inspected during KAMS field surveillance (23% average). For GLT O-rings, service life based on the room temperature leak rate criterion is comparable to that predicted by compression stress relaxation (CSR) data at higher temperatures (350--400 F). While there are no comparable failure data yet at aging temperatures below 300 F, extrapolations of the data for GLT O-rings suggests that CSR model predictions provide a conservative prediction of service

  11. Ultra-low energy storage ring at FLAIR

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  12. Control of ring lasers by means of coupled cavities

    DEFF Research Database (Denmark)

    Buchhave, Preben; Abitan, Haim; Tidemand-Lichtenberg, Peter

    2000-01-01

    Variable phase coupling to an external ring is used to control a unidirectional ring laser. The observed behavior of the coupled rings is explained theoretically. We have found experimentally that by quickly changing the phase of the feedback from the external ring it is possible to Q......-switch the ring laser. Also, at certain values of the phase of the feedback in the external ring, instabilities in the total system occur and oscillations arise in the ring laser....

  13. The Conversion of Wiswesser Line Notations to Ring Codes. I. The Conversion of Ring Systems

    Science.gov (United States)

    Granito, Charles E.; And Others

    1972-01-01

    The computerized conversion of Wiswesser Line Notations to Ring Codes, using a two-part approach, and the set of computer programs generated for the conversion of ring systems are described. (9 references) (Author)

  14. Status report on RIKEN Ring Cyclotron

    International Nuclear Information System (INIS)

    Yano, Y.

    1988-01-01

    This paper gives a status report on RIKEN Ring Cyclotron (RRC), successfully commissioned on December 16, 1986. The routine operation of RRC began in April, 1987, and was made until March 1988. April and May were devoted to the machine studies, and beams were delivered to the experiments from the end of May. Seven kinds of ion species from carbon to copper were used for the nuclear physics and atomic physics experiments during these one-year runs. High quality beams with transverse emittances less than 10 mm mrad, energy spread of approximately 0.1% and pulse width less than 300 psec were extracted. Since the middle of March, 1988, RRC has been shut down for extending the beam transfer lines and installing the various experimental setups. Next experimental program will start in July, 1988. The initial operational status of RRC is described as well as the running construction program of the new injector, a K70 AVF cyclotron with an external ECR ion source

  15. The last piece of the ring

    CERN Multimedia

    2008-01-01

    In a sequel to the recent success at CMS, the last section of the LHC beam vacuum system was installed in ATLAS on Monday 16 June. The place where experiment and accelerator meet, the completion of the last part of the continuous 27 km beampipe signals how near the LHC is to the circulation of its first beam. Watch the video! The last section of the LHC beampipe being installed in ATLAS.Although a seemingly simple piece of technology in comparison with the complexity of the detectors, the beampipe is a carefully designed and essential part of both the experiments and the LHC. The section of beam pipe that completed the LHC ring on Monday 16 June is about 20 metres from the centre of ATLAS, very close to where the first magnets of the LHC are located. Unlike the central ATLAS beampipe, which is made of beryllium, the final section is made of stainless steel. An aluminium cone surrounds the stainless steel tube with the super slim...

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

    OpenAIRE

    Schurmans, C?line; De Baetselier, Irith; Kestelyn, Evelyne; Jespers, Vicky; Delvaux, Th?r?se; Agaba, Stephen K; van Loen, Harry; Menten, Joris; van de Wijgert, Janneke; Crucitti, Tania

    2015-01-01

    Background Research is ongoing to develop multipurpose vaginal rings to be used continuously for contraception and to prevent Human Immunodeficiency Virus (HIV) infection. Contraceptive vaginal rings (CVRs) are available in a number of countries and are most of the time used intermittently i.e. three weeks out of a 4-week cycle. Efficacy trials with a dapivirine-containing vaginal ring for HIV prevention are ongoing and plans to develop multi-purpose vaginal rings for prevention of both HIV a...

  17. Low-emittance Storage Rings

    CERN Document Server

    Wolski, Andrzej

    2014-01-01

    The effects of synchrotron radiation on particle motion in storage rings are discussed. In the absence of radiation, particle motion is symplectic, and the beam emittances are conserved. The inclusion of radiation effects in a classical approximation leads to emittance damping: expressions for the damping times are derived. Then, it is shown that quantum radiation effects lead to excitation of the beam emittances. General expressions for the equilibrium longitudinal and horizontal (natural) emittances are derived. The impact of lattice design on the natural emittance is discussed, with particular attention to the special cases of FODO-, achromat- and theoretical-minimum-emittance-style lattices. Finally, the effects of betatron coupling and vertical dispersion (generated by magnet alignment and lattice tuning errors) on the vertical emittance are considered.

  18. Main ring transition crossing simulations

    International Nuclear Information System (INIS)

    Kourbanis, I.; Ng, King-Yuen.

    1990-10-01

    We used ESME to simulate transition crossing in the Main Ring (MR). For the simulations, we followed the MR 29 cycle used currently for bar p production with a flat top of 120 GeV. In Sect. II, some inputs are discussed. In Sect. III, we present simulations with space charge turned off so that the effect of nonlinearity can be studied independently. When space charge is turned on in Sect. IV, we are faced with the problem of statistical errors due to binning, an analysis of which is given in the Appendices. Finally in Sects. V and VI, the results of simulations with space charge are presented and compared with the experimental measurements. 7 refs., 6 figs

  19. VUV optical ring resonator for Duke storage ring free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.H.; Litvinenko, V.N.; Madey, J.M.J. [Duke Univ., Durham, NC (United States)] [and others

    1995-12-31

    The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.

  20. Electron beam cooling at a magnetic storage ring, TARN II, and an electrostatic storage ring

    International Nuclear Information System (INIS)

    Tanabe, Tetsumi

    2006-01-01

    At the High Energy Accelerator Research Organization (KEK), a magnetic storage ring, TARN II, with an electron cooler was operated from 1989 to 1999, while an electrostatic storage ring with a small electron cooler has been operational since 2000. In this paper, the electron cooling at TARN II and the electrostatic storage ring is described. (author)

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

    NARCIS (Netherlands)

    Wang, C.; Geijselaers, H. J.M.; Omerspahic, E.; Recina, V.; van den Boogaard, A. H.

    2015-01-01

    As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. In the production of hot rolled rings, defects such as porosity can sometimes be found in high alloyed steel, manufactured from ingots having macro-segregation. For

  2. Development Of A Hydrogen And Deuterium Polarized Gas Target For Application In Storage Rings

    International Nuclear Information System (INIS)

    Haeberli, Willy

    2009-01-01

    The exploration of spin degrees of freedom in nuclear and high-energy interactions requires the use of spin-polarized projectiles and/or spin-polarized targets. During the last two decades, the use of external beams from cyclotrons has to a large extent been supplanted by use of circulating beams stored in storage rings. In these experiments, the circulating particles pass millions of times through targets internal to the ring. Thus the targets need to be very thin to avoid beam loss by scattering out of the acceptance aperture of the ring.

  3. Experimental Observation of Fermi-Pasta-Ulam Recurrence in a Nonlinear Feedback Ring System

    Science.gov (United States)

    Wu, Mingzhong; Patton, Carl E.

    2007-01-01

    Fermi-Pasta-Ulam recurrence through soliton dynamics has been realized. The experiment used a magnetic film strip-based active feedback ring. At some ring gain level, a wide spin wave pulse is self-generated in the ring. As the pulse circulates, it separates into two envelop solitons with different speeds. When the fast soliton catches up and collides with the slow soliton, the initial wide pulse is perfectly reconstructed. The repetition of this process leads to periodic recurrences of the initial pulse.

  4. Effects of decaying image currents on electron rings during compression between side walls and motion along conducting cylinders

    International Nuclear Information System (INIS)

    Herrmann, W.

    1974-11-01

    Decaying image currents consume energy which has to be supplied by the field producing electron ring. For very high currents (I > 10 3 A, particle number Ne > approximately 10 14 ) the losses become important and have to be included in the calculation of the ring dynamics. Special attention has been given to the focussing effects of the decaying image currents during compression and to the retarding force which develops when the ring is moved along a resistive cylinder. It is emphasized that in the latter case the ring experiences a 'run-away-situation', when the ratio of its velocity to the surface resistivity exceeds a certain limit. (orig.) [de

  5. MeV proton flux predictions near Saturn's D ring.

    Science.gov (United States)

    Kollmann, P; Roussos, E; Kotova, A; Cooper, J F; Mitchell, D G; Krupp, N; Paranicas, C

    2015-10-01

    Radiation belts of MeV protons have been observed just outward of Saturn's main rings. During the final stages of the mission, the Cassini spacecraft will pass through the gap between the main rings and the planet. Based on how the known radiation belts of Saturn are formed, it is expected that MeV protons will be present in this gap and also bounce through the tenuous D ring right outside the gap. At least one model has suggested that the intensity of MeV protons near the planet could be much larger than in the known belts. We model this inner radiation belt using a technique developed earlier to understand Saturn's known radiation belts. We find that the inner belt is very different from the outer belts in the sense that its intensity is limited by the densities of the D ring and Saturn's upper atmosphere, not by radial diffusion and satellite absorption. The atmospheric density is relatively well constrained by EUV occultations. Based on that we predict an intensity in the gap region that is well below that of the known belts. It is more difficult to do the same for the region magnetically connected to the D ring since its density is poorly constrained. We find that the intensity in this region can be comparable to the known belts. Such intensities pose no hazard to the mission since Cassini would only experience these fluxes on timescales of minutes but might affect scientific measurements by decreasing the signal-to-contamination ratio of instruments.

  6. The King's Ring: A Matter of Trust

    DEFF Research Database (Denmark)

    Sterrett, Joseph William

    2018-01-01

    This essay examines the material and social effects of an exchange of trust between a king, Henry VIII, and his counsellor, Thomas Cranmer in Shakespeare and Fletcher’s All is True. The ring that the King gives Cranmer is both nothing and everything: nothing in that it could be anything, any ring...

  7. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.

    2009-06-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  8. Hawking radiation of black rings from anomalies

    International Nuclear Information System (INIS)

    Chen Bin; He Wei

    2008-01-01

    We derive Hawking radiation of five-dimensional black rings from gauge and gravitational anomalies using the method proposed by Robinson and Wilczek. We find, as in the black hole case, that the problem could reduce to a (1+1)-dimensional field theory and the anomalies result in correct Hawking temperature for neutral, dipole and charged black rings

  9. IAG ring test animal proteins 2016

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Rhee, van de N.E.; Scholtens-Toma, I.M.J.; Prins, T.W.; Vliege, J.J.M.; Pinckaers, V.G.Z.

    2016-01-01

    The annual ring test for the detection of animal proteins in animal feed of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy was organized by RIKILT - Wageningen UR, The Netherlands. The aim of the ring study was to provide the participants information

  10. Reversible decay of ring dark solitons

    International Nuclear Information System (INIS)

    Toikka, L A; Suominen, K-A

    2014-01-01

    We show how boundary effects can cause a Bose–Einstein condensate to periodically oscillate between a (circular) array of quantized vortex–antivortex pairs and a (ring) dark soliton. If the boundary is restrictive enough, the ring dark soliton becomes long-lived. (paper)

  11. The multi-bend achromat storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Mikael [MAX IV Laboratory Ole Römers v. 1 22100 Lund Sweden (Sweden)

    2016-07-27

    Not very long ago, the 3{sup rd} generation storage ring technology was judged as mature. Most of the 3{sup rd} generation storage rings used the Double-Bend Achromat (DBA) or Triple-Bend Achromat (TBA) concepts. It was however a well-known fact that increasing the number of magnet cells in the rings is a powerful way of decreasing the electron beam emittance and thus the source brilliance, but at the penalty of increasing the size and cost of the rings. Preserving the Dynamic Aperture (DA) in the rings became also an issue when increasing the number of magnet cells. The Multi-Bend Achromat (MBA) concept, including a miniaturization of the ring elements, has now drastically changed the picture. The MBA rings, now in construction or being planned, offer orders of magnitudes higher brilliance than rings of conventional designs. Several light sources around the world are now implementing or planning to implement this MBA concept. This article touches on the science drivers for higher brilliance. We will then describe the MBA concept with its advantages as well as its challenges. A short survey of the MBA activity around the world will also be presented. The author apologies for focusing on the MAX IV project regarding technical solutions. This is motivated by that MAX IV is the facility he knows best and it might be regarded as a fore-runner for the MBA concept.

  12. Collective effects in isochronous storage rings

    International Nuclear Information System (INIS)

    Chao, A.W.; Kim, K.-J.

    1996-01-01

    We studied the collective instabilities in isochronous storage rings using a linac-type analysis. Simple criteria for avoiding the longitudinal and transverse instabilities are developed by employing a two-particle model. Numerical examples show that these conditions do not impose serious performance restrictions for two of the currently proposed isochronous storage rings

  13. Local duality for 2-dimensional local ring

    Indian Academy of Sciences (India)

    dimensional complete local ring whose residue field is an n-dimensional local field in the sense of. Kato–Parshin. Our results generalize the Saito works in the case n = 0 and are applied to study the Bloch–Ogus complex for such rings in various cases.

  14. Cancer caused by radioactive gold rings

    International Nuclear Information System (INIS)

    Callary, E.M.

    1989-01-01

    Two recent cases of skin cancer caused by radioactive gold rings are described. The gold was contaminated with radon daughters from hollow goldseeds used to hold radon, back in the 1930s or possibly later. Other radioactive gold rings are probably being worn. The Canadian AECB offers free testing

  15. Rank 2 fusion rings are complete intersections

    DEFF Research Database (Denmark)

    Andersen, Troels Bak

    We give a non-constructive proof that fusion rings attached to a simple complex Lie algebra of rank 2 are complete intersections.......We give a non-constructive proof that fusion rings attached to a simple complex Lie algebra of rank 2 are complete intersections....

  16. Magnetic moment of single layer graphene rings

    Science.gov (United States)

    Margulis, V. A.; Karpunin, V. V.; Mironova, K. I.

    2018-01-01

    Magnetic moment of single layer graphene rings is investigated. An analytical expression for the magnetic moment as a function of the magnetic field flux through the one-dimensional quantum rings is obtained. This expression has the oscillation character. The oscillation period is equal to one flux quanta.

  17. The multi-bend achromat storage rings

    International Nuclear Information System (INIS)

    Eriksson, Mikael

    2016-01-01

    Not very long ago, the 3"r"d generation storage ring technology was judged as mature. Most of the 3"r"d generation storage rings used the Double-Bend Achromat (DBA) or Triple-Bend Achromat (TBA) concepts. It was however a well-known fact that increasing the number of magnet cells in the rings is a powerful way of decreasing the electron beam emittance and thus the source brilliance, but at the penalty of increasing the size and cost of the rings. Preserving the Dynamic Aperture (DA) in the rings became also an issue when increasing the number of magnet cells. The Multi-Bend Achromat (MBA) concept, including a miniaturization of the ring elements, has now drastically changed the picture. The MBA rings, now in construction or being planned, offer orders of magnitudes higher brilliance than rings of conventional designs. Several light sources around the world are now implementing or planning to implement this MBA concept. This article touches on the science drivers for higher brilliance. We will then describe the MBA concept with its advantages as well as its challenges. A short survey of the MBA activity around the world will also be presented. The author apologies for focusing on the MAX IV project regarding technical solutions. This is motivated by that MAX IV is the facility he knows best and it might be regarded as a fore-runner for the MBA concept.

  18. Fuzzy Rough Ring and Its Prop erties

    Institute of Scientific and Technical Information of China (English)

    REN Bi-jun; FU Yan-ling

    2013-01-01

    This paper is devoted to the theories of fuzzy rough ring and its properties. The fuzzy approximation space generated by fuzzy ideals and the fuzzy rough approximation operators were proposed in the frame of fuzzy rough set model. The basic properties of fuzzy rough approximation operators were analyzed and the consistency between approximation operators and the binary operation of ring was discussed.

  19. Genetics Home Reference: ring chromosome 14 syndrome

    Science.gov (United States)

    ... be something about the ring structure itself that causes epilepsy. Seizures may occur because certain genes on the ... mapping of telomeric 14q32 deletions: search for the cause of seizures. Am J Med Genet A. ... L, Elia M, Vigevano F. Epilepsy in ring 14 chromosome syndrome. Epilepsy Behav. 2012 ...

  20. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.; Salama, Khaled N.

    2009-01-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  1. The Fine Structure of Herman Rings

    DEFF Research Database (Denmark)

    Fagella, Nuria; Henriksen, Christian

    2017-01-01

    We study the geometric structure of the boundary of Herman rings in a model family of Blaschke products of degree 3 (up to quasiconformal deformation). Shishikura’s quasiconformal surgery relates the Herman ring to the Siegel disk of a quadratic polynomial. By studying the regularity properties...

  2. C and C* among intermediate rings

    NARCIS (Netherlands)

    Sack, J.; Watson, S.

    2014-01-01

    Given a completely regular Hausdorff space X, an intermediate ring A(X) is a ring of real valued continuous functions between C*(X) and C(X). We discuss two correspondences between ideals in A(X) and z-filters on X, both reviewing old results and introducing new results. One correspondence, ZA,

  3. Limits to the observation of coherent oscillations in a SQUID ring

    International Nuclear Information System (INIS)

    Diggins, J.

    1995-01-01

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

  4. Flow dynamics in distillation columns packed with Dixon rings as used in isotope separation

    International Nuclear Information System (INIS)

    Gilath, C.; Cohen, H.; Wolf, D.

    1977-01-01

    Packed distillation columns are common in isotope separation. The pressure drop serves as an indication for the hydrodynamic state of the column. Models were formulated for flow and pressure drop dynamics in packed distillation columns. These models were confirmed on columns packed with Dixon rings and operated with water for separation of oxygen isotopes. Liquid holdup displacement is very important in isotope separation practice. Experiments proved that distillation columns packed with Dixon rings exhibit a behaviour close to plug flow. (author)

  5. Cooling rings for TeV colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1985-02-01

    Consideration is given to quantum fluctuations, intra beam scattering, cooling rates, and ring acceptance in order to see if one can obtain a normalized emittance of 10 -8 in any plausible cooling ring. It is concluded that only a small gain is obtained by varying the partition functions, but a very significant gain is made by using higher bending fields. The ring is found to get bigger if the magnet apertures are increased. The ring diameter is found to increase if the momentum spread of the beam is reduced. It is shown that the power can be reduced by allowing a high beamstrahlung energy loss resulting in higher current in the cooling ring. Parameters are also given for a 10 -7 m radian emittance case

  6. Ring power balance observing plasma stability constraints

    International Nuclear Information System (INIS)

    Campbell, R.B.; Logan, B.G.

    1982-01-01

    Ring power balance is performed for an E-ring stabilized tandem mirror reactor, taking into account constraints imposed by plasma stability. The two most important criteria are the stability of the core interchange and hot electron interchange modes. The former determines the ring thickness, the latter determines the minimum hot electron temperature; both quantities are important for power balance. The combination of the hot electron interchange constraint and the fact that the barrier density is low places the operating point on the synchrotron dominated branch of power balance. The reference case considered here requires a reasonable 34 MW of heating power deposited in the rings. We also have examined the sensitivity of the required ring power on uncertainties in the numerical coefficients of the stability constraints. We have found that the heating power is strongly affected

  7. Bernstein instability driven by thermal ring distribution

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Peter H., E-mail: yoonp@umd.edu [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States); School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of); Hadi, Fazal; Qamar, Anisa [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan)

    2014-07-15

    The classic Bernstein waves may be intimately related to banded emissions detected in laboratory plasmas, terrestrial, and other planetary magnetospheres. However, the customary discussion of the Bernstein wave is based upon isotropic thermal velocity distribution function. In order to understand how such waves can be excited, one needs an emission mechanism, i.e., an instability. In non-relativistic collision-less plasmas, the only known Bernstein wave instability is that associated with a cold perpendicular velocity ring distribution function. However, cold ring distribution is highly idealized. The present Brief Communication generalizes the cold ring distribution model to include thermal spread, so that the Bernstein-ring instability is described by a more realistic electron distribution function, with which the stabilization by thermal spread associated with the ring distribution is demonstrated. The present findings imply that the excitation of Bernstein waves requires a sufficiently high perpendicular velocity gradient associated with the electron distribution function.

  8. Bernstein instability driven by thermal ring distribution

    International Nuclear Information System (INIS)

    Yoon, Peter H.; Hadi, Fazal; Qamar, Anisa

    2014-01-01

    The classic Bernstein waves may be intimately related to banded emissions detected in laboratory plasmas, terrestrial, and other planetary magnetospheres. However, the customary discussion of the Bernstein wave is based upon isotropic thermal velocity distribution function. In order to understand how such waves can be excited, one needs an emission mechanism, i.e., an instability. In non-relativistic collision-less plasmas, the only known Bernstein wave instability is that associated with a cold perpendicular velocity ring distribution function. However, cold ring distribution is highly idealized. The present Brief Communication generalizes the cold ring distribution model to include thermal spread, so that the Bernstein-ring instability is described by a more realistic electron distribution function, with which the stabilization by thermal spread associated with the ring distribution is demonstrated. The present findings imply that the excitation of Bernstein waves requires a sufficiently high perpendicular velocity gradient associated with the electron distribution function

  9. Vaginal rings for delivery of HIV microbicides

    Directory of Open Access Journals (Sweden)

    McCoy CF

    2012-11-01

    Full Text Available R Karl Malcolm, Susan M Fetherston, Clare F McCoy, Peter Boyd, Ian MajorSchool of Pharmacy, Queen's University Belfast, Belfast, UKAbstract: Following the successful development of long-acting steroid-releasing vaginal ring devices for the treatment of menopausal symptoms and contraception, there is now considerable interest in applying similar devices to the controlled release of microbicides against HIV. In this review article, the vaginal ring concept is first considered within the wider context of the early advances in controlled-release technology, before describing the various types of ring device available today. The remainder of the article highlights the key developments in HIV microbicide-releasing vaginal rings, with a particular focus on the dapivirine ring that is presently in late-stage clinical testing.Keywords: controlled release, sustained release, antiretroviral, dapivirine, SILCS diaphragm, silicone elastomer, thermoplastic

  10. Semi-algebraic function rings and reflectors of partially ordered rings

    CERN Document Server

    Schwartz, Niels

    1999-01-01

    The book lays algebraic foundations for real geometry through a systematic investigation of partially ordered rings of semi-algebraic functions. Real spectra serve as primary geometric objects, the maps between them are determined by rings of functions associated with the spectra. The many different possible choices for these rings of functions are studied via reflections of partially ordered rings. Readers should feel comfortable using basic algebraic and categorical concepts. As motivational background some familiarity with real geometry will be helpful. The book aims at researchers and graduate students with an interest in real algebra and geometry, ordered algebraic structures, topology and rings of continuous functions.

  11. Generation of stable mixed-compact-toroid rings by inducing plasma currents in strong E rings

    International Nuclear Information System (INIS)

    Jayakumar, R.; Taggart, D.P.; Parker, M.R.; Fleischmann, H.H.

    1989-01-01

    In the RECE-Christa device, hybrid-type compact toroid rings are generated by inducing large toroidal plasma currents I rho in strong electron rings using a thin induction coil positioned along the ring axis. Starting from field-reversal values δ ο = 50 - 120 percent of the original pure fast-electron ring, the induced plasma current I rho raises δ to a maximum value of up to 240 percent with I rho contributing more than 50 percent of the total ring current. Quite interestingly, the generated hybrid compact toroid configurations appear gross-stable during the full I rho pulse length (half-amplitude width about 100 μs)

  12. Heat transfer in circular ring channel under reflooding conditions

    International Nuclear Information System (INIS)

    Blaha, V.; Nikonov, S.P.

    1981-01-01

    The method and equipment are described for flooding experiments in a ring-shaped channel with an unheated external wall. The values measured during the experiment are given of tube wall temperature, the power input of the heating rod, the temperature of the flooding medium, the flow, the temperature of the envelope, pressure gradient in the measured section, pressure in the storage tank and temperature in the upper chamber. The dependence is shown of the coefficient of heat transfer on the temperature gradient between the wall and the medium which may be degasified water, CO 2 saturated water of N 2 saturated water. (J.B.)

  13. Electro-optical hybrid slip ring

    Science.gov (United States)

    Hong, En

    2005-11-01

    The slip ring is a rotary electrical interface, collector, swivel or rotary joint. It is a physical system that can perform continuous data transfer and data exchange between a stationary and a rotating structure. A slip ring is generally used to transfer data or power from an unrestrained, continuously rotating electro-mechanical system in real-time, thereby simplifying operations and eliminating damage-prone wires dangling from moving joints. Slip rings are widely used for testing, evaluating, developing and improving various technical equipment and facilities with rotating parts. They are widely used in industry, especially in manufacturing industries employing turbo machinery, as in aviation, shipbuilding, aerospace, defense, and in precise facilities having rotating parts such as medical Computerized Tomography (CT) and MRI scanners and so forth. Therefore, any improvement in slip ring technology can impact large markets. Research and development in this field will have broad prospects long into the future. The goal in developing the current slip ring technology is to improve and increase the reliability, stability, anti-interference, and high data fidelity between rotating and stationary structures. Up to now, there have been numerous approaches used for signal and data transfer utilizing a slip ring such as metal contacts, wires, radio transmission, and even liquid media. However, all suffer from drawbacks such as data transfer speed limitations, reliability, stability, electro-magnetic interference and durability. The purpose of the current research is to break through these basic limitations using an optical solution, thereby improving performance in current slip ring applications. This dissertation introduces a novel Electro-Optical Hybrid Slip Ring technology, which makes "through the air" digital-optical communication between stationary and rotating systems a reality with high data transfer speed, better reliability and low interference susceptibility

  14. Iterative image-domain ring artifact removal in cone-beam CT

    Science.gov (United States)

    Liang, Xiaokun; Zhang, Zhicheng; Niu, Tianye; Yu, Shaode; Wu, Shibin; Li, Zhicheng; Zhang, Huailing; Xie, Yaoqin

    2017-07-01

    Ring artifacts in cone beam computed tomography (CBCT) images are caused by pixel gain variations using flat-panel detectors, and may lead to structured non-uniformities and deterioration of image quality. The purpose of this study is to propose a method of general ring artifact removal in CBCT images. This method is based on the polar coordinate system, where the ring artifacts manifest as stripe artifacts. Using relative total variation, the CBCT images are first smoothed to generate template images with fewer image details and ring artifacts. By subtracting the template images from the CBCT images, residual images with image details and ring artifacts are generated. As the ring artifact manifests as a stripe artifact in a polar coordinate system, the artifact image can be extracted by mean value from the residual image; the image details are generated by subtracting the artifact image from the residual image. Finally, the image details are compensated to the template image to generate the corrected images. The proposed framework is iterated until the differences in the extracted ring artifacts are minimized. We use a 3D Shepp-Logan phantom, Catphan©504 phantom, uniform acrylic cylinder, and images from a head patient to evaluate the proposed method. In the experiments using simulated data, the spatial uniformity is increased by 1.68 times and the structural similarity index is increased from 87.12% to 95.50% using the proposed method. In the experiment using clinical data, our method shows high efficiency in ring artifact removal while preserving the image structure and detail. The iterative approach we propose for ring artifact removal in cone-beam CT is practical and attractive for CBCT guided radiation therapy.

  15. Vortex-ring-induced large bubble entrainment during drop impact

    KAUST Repository

    Thoraval, Marie-Jean

    2016-03-29

    For a limited set of impact conditions, a drop impacting onto a pool can entrap an air bubble as large as its own size. The subsequent rise and rupture of this large bubble plays an important role in aerosol formation and gas transport at the air-sea interface. The large bubble is formed when the impact crater closes up near the pool surface and is known to occur only for drops that are prolate at impact. Herein we use experiments and numerical simulations to show that a concentrated vortex ring, produced in the neck between the drop and the pool, controls the crater deformations and pinchoff. However, it is not the strongest vortex rings that are responsible for the large bubbles, as they interact too strongly with the pool surface and self-destruct. Rather, it is somewhat weaker vortices that can deform the deeper craters, which manage to pinch off the large bubbles. These observations also explain why the strongest and most penetrating vortex rings emerging from drop impacts are not produced by oblate drops but by more prolate drop shapes, as had been observed in previous experiments.

  16. Wear Analysis of Top Piston Ring to Reduce Top Ring Reversal Bore Wear

    Directory of Open Access Journals (Sweden)

    P. Ilanthirayan

    2017-12-01

    Full Text Available The piston rings are the most important part in engine which controls the lubricating oil consumption and blowby of the gases. The lubricating film of oil is provided to seal of gases towards crankcase and also to give smooth friction free translatory motion between rings and liner. Of the three rings present top ring is more crucial as it does the main work of restricting gases downwards the crankcase. Boundary lubrication is present at the Top dead centre (TDC and Bottom dead centre (BDC of the liner surface. In addition to this, top ring is exposed to high temperature gases which makes the oil present near the top ring to get evaporated and decreasing its viscosity, making metal-metal contact most of the time. Due to this at TDC, excess wear happens on the liner which is termed as Top ring reversal bore wear. The wear rate depends upon many parameters such as lubrication condition, viscosity index, contact type, normal forces acting on ring, geometry of ring face, surface roughness, material property. The present work explores the wear depth for different geometries of barrel ring using Finite Element model with the help of Archard wear law and the same is validated through experimentation. The study reveals that Asymmetric barrel rings have less contact pressure which in turn reduces the wear at Top dead centre.

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

    Science.gov (United States)

    Buta, Ronald J.

    2017-11-01

    Rings are important and characteristic features of disc-shaped galaxies. This paper is the first in a series that re-visits galactic rings with the goals of further understanding the nature of the features and for examining their role in the secular evolution of galaxy structure. The series begins with a new sample of 3962 galaxies drawn from the Galaxy Zoo 2 citizen science data base, selected because zoo volunteers recognized a ring-shaped pattern in the morphology as seen in Sloan Digital Sky Survey colour images. The galaxies are classified within the framework of the Comprehensive de Vaucouleurs revised Hubble-Sandage system. It is found that zoo volunteers cued on the same kinds of ring-like features that were recognized in the 1995 Catalogue of Southern Ringed Galaxies. This paper presents the full catalogue of morphological classifications, comparisons with other sources of classifications and some histograms designed mainly to highlight the content of the catalogue. The advantages of the sample are its large size and the generally good quality of the images; the main disadvantage is the low physical resolution that limits the detectability of linearly small rings such as nuclear rings. The catalogue includes mainly inner and outer disc rings and lenses. Cataclysmic (`encounter-driven') rings (such as ring and polar ring galaxies) are recognized in less than 1 per cent of the sample.

  18. Feasibility of beam crystallization in a cooler storage ring

    Directory of Open Access Journals (Sweden)

    Yosuke Yuri

    2005-11-01

    Full Text Available It has been known theoretically that a charged-particle beam circulating in a storage ring exhibits an “ordered” configuration at the space-charge limit. Such an ultimate state of matter is called a crystalline beam whose emittance is ideally equal to zero except for quantum noise. This paper discusses how close one can come to various ordered states by employing currently available accelerator technologies. The dynamic nature of ultracold beams and conditions required for crystallization are briefly reviewed. Molecular dynamics simulations are performed to study the feasibility of this unique phenomenon, considering practical situations in general cooling experiments. It is pointed out that several essential obstacles must be overcome to reach a three-dimensional crystalline state in a storage ring. Doppler laser cooling of ion beams is also numerically simulated to explore the possibility of beam crystallization in an existing machine.

  19. High duty factor structures for e+e- storage rings

    International Nuclear Information System (INIS)

    Allen, M.A.; Karvonen, L.G.

    1976-01-01

    The next generation e + e - storage rings will need rf systems similar to those required for a continuous-duty linac of over 50 MeV. For the PEP Storage Ring at 18 GeV, it is presently planned to provide a peak accelerating voltage of 77 MV in 18 aluminum accelerating structures, each structure consisting of five slot-coupled cells operating in the π mode. Operating experience with the SPEAR five-cell structure is discussed. Power to each structure is provided by a 125-kW high-efficiency four-cavity klystron. No isolation has been used and the resulting interaction between the accelerating structures, klystrons and the stored beams is discussed

  20. The vacuum interlock system for the CELSIUS ring

    International Nuclear Information System (INIS)

    Gajewski, K.

    1990-01-01

    A vacuum interlock system has been designed and built for the CELSIUS storage ring. The ultrahigh-vacuum system of CELSIUS has a design pressure of 10 -11 mbar. This is achieved by using vacuum-fired stainless-steel chambers, baking the whole ring to 300degC and running some 50 sputter ion and titanium sublimation pumps. The turbopumps, combined with roughing pumps, are used during the pump-down and the bake-out. The pressure is monitored by Penning vacuum gauges. There is a number of programmable pressure thresholds set to trigger various events (like closing the sector valves, disabling the bake-out, etc.). The interlock system is based on the Mitsubishi programmable logic controller (PLC). An IBM PC is used as an operator's console. The operation and performance of the system is described. On the basis of present experience an upgrading of the system is suggested. (orig.)

  1. From rotating atomic rings to quantum Hall states.

    Science.gov (United States)

    Roncaglia, M; Rizzi, M; Dalibard, J

    2011-01-01

    Considerable efforts are currently devoted to the preparation of ultracold neutral atoms in the strongly correlated quantum Hall regime. However, the necessary angular momentum is very large and in experiments with rotating traps this means spinning frequencies extremely near to the deconfinement limit; consequently, the required control on parameters turns out to be too stringent. Here we propose instead to follow a dynamic path starting from the gas initially confined in a rotating ring. The large moment of inertia of the ring-shaped fluid facilitates the access to large angular momenta, corresponding to giant vortex states. The trapping potential is then adiabatically transformed into a harmonic confinement, which brings the interacting atomic gas in the desired quantum-Hall regime. We provide numerical evidence that for a broad range of initial angular frequencies, the giant-vortex state is adiabatically connected to the bosonic ν = 1/2 Laughlin state.

  2. Dissociative recombination and excitation in ion storage rings

    International Nuclear Information System (INIS)

    Larsson, Mats

    2000-01-01

    The application of ion storage rings to the study of electron-molecular ion interaction has led to an experimental breakthrough. The development since the first experiments with molecular ions in storage rings about seven years ago, which in themselves represented a big leap forward, has been striking, and was impossible to envision at the outset. The development has been driven by advances in accelerator physics, detector technology, challenging applications in astrophysics and atmospheric physics, and by a close interplay with theory. Despite the remarkable progress, many important questions remain unanswered. For example, even for someone with a good knowledge of molecular physics it may come as a surprise that it is far from understood how the simplest polyatomic molecule H 3 + recombines with electrons, and it remains an experimental controversy at what rate it recombines

  3. Computational logic with square rings of nanomagnets

    Science.gov (United States)

    Arava, Hanu; Derlet, Peter M.; Vijayakumar, Jaianth; Cui, Jizhai; Bingham, Nicholas S.; Kleibert, Armin; Heyderman, Laura J.

    2018-06-01

    Nanomagnets are a promising low-power alternative to traditional computing. However, the successful implementation of nanomagnets in logic gates has been hindered so far by a lack of reliability. Here, we present a novel design with dipolar-coupled nanomagnets arranged on a square lattice to (i) support transfer of information and (ii) perform logic operations. We introduce a thermal protocol, using thermally active nanomagnets as a means to perform computation. Within this scheme, the nanomagnets are initialized by a global magnetic field and thermally relax on raising the temperature with a resistive heater. We demonstrate error-free transfer of information in chains of up to 19 square rings and we show a high level of reliability with successful gate operations of ∼94% across more than 2000 logic gates. Finally, we present a functionally complete prototype NAND/NOR logic gate that could be implemented for advanced logic operations. Here we support our experiments with simulations of the thermally averaged output and determine the optimal gate parameters. Our approach provides a new pathway to a long standing problem concerning reliability in the use of nanomagnets for computation.

  4. Novel miniature high power ring filter

    International Nuclear Information System (INIS)

    Huang Huifen; Mao Junfa; Luo Zhihua

    2005-01-01

    The power handling capability of high temperature superconducting (HTS) filters is limited due to current concentration at the edges of the superconducting films. This problem can be overcome by using ring resonator, which employs the edge current free and reduces the current concentration. However, this kind of filter has large size. In order to reduce the cost and size and increase the power handling capability, in this paper a HTS photonic bandgap (PBG) structure filter is developed. The proposed pass band filter with PBG structure exhibits center frequency 12.23 GHz, steepness (about 35 dB/GHz), bandwidth (-3 dB bandwidth is 0.045 GHz), and low insertion loss (about -0.5 dB), and can handle input power up to 1 W (this value was limited by the measurement instrument used in the experiment). The size is reduced by 25%, insertion loss reduced by 37.5%, and steeper roll-off of the filter is also obtained compared with that in published literature

  5. Fermilab Antiproton source, Recycler ring and Main Injector

    Energy Technology Data Exchange (ETDEWEB)

    Nagaitsev, Sergei [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-03-22

    The antiproton source for a proton-antiproton collider at Fermilab was proposed in 1976 [1]. The proposal argued that the requisite luminosity (~1029 cm-2sec-1) could be achieved with a facility that would produce and cool approximately 1011 antiprotons per day. Funding for the Tevatron I project (to construct the Antiproton source) was initiated in 1981 and the Tevatron ring itself was completed, as a fixed target accelerator, in the summer of 1983 and the Antiproton Source was completed in 1985. At the end of its operations in 2011, the Fermilab antiproton production complex consisted of a sophisticated target system, three 8-GeV storage rings (namely the Debuncher, Accumulator and Recycler), 25 independent multi-GHz stochastic cooling systems, the world’s only relativistic electron cooling system and a team of technical experts equal to none. Sustained accumulation of antiprotons was possible at the rate of greater than 2.5×1011 per hour. Record-size stacks of antiprotons in excess of 3×1012 were accumulated in the Accumulator ring and 6×1012 in the Recycler. In some special cases, the antiprotons were stored in rings for more than 50 days. Note, that over the years, some 1016 antiprotons were produced and accumulated at Fermilab, which is about 17 nanograms and more than 90% of the world’s total man-made quantity of nuclear antimatter. The accelerator complex at Fermilab supported a broad physics program including the Tevatron Collider Run II [2], neutrino experiments using 8 GeV and 120 GeV proton beams, as well as a test beam facility and other fixed target experiments using 120 GeV primary proton beams. The following sections provide a brief description of Fermilab accelerators as they operated at the end of the Collider Run II (2011).

  6. Airpower, Chaos, and Infrastructure: Lords of the Rings

    National Research Council Canada - National Science Library

    Felker, Edward

    1998-01-01

    .... It focuses on the third ring (infrastructure) of John A. Warden III's theory of five strategic rings, which the author argues is often neglected in the debate over the importance of leadership (first ring...

  7. Recycler ring conceptual design study

    International Nuclear Information System (INIS)

    Jackson, G.

    1995-01-01

    The Tevatron Collider provides the highest center of mass energy collisions in the world. To fully exploit this unique tool, Fermilab is committed to a program of accelerator upgrades for the purpose of increasing the Collider luminosity. Over the past 7 years the luminosity has been increased from a peak of 1.6x10 30 cm -2 sec -1 in 1989 to over 3x10 31 cm -2 sec -1 during 1995. The Main Injector will supply a larger flux of protons for antiproton production and more intense proton bunches for use in the Collider, and this is expected to increase the peak luminosity to close to 1x10 32 cm -2 sec -1 . Further increases in luminosity will require additional upgrades to the Fermilab accelerator complex. This report documents the design of a new fixed-energy storage ring to be placed in the Main Injector tunnel which will provide an initial factor of 2 increase to 2x10 32 cm -2 sec -1 , and ultimately provide the basis for an additional order of magnitude luminosity increase up to 1x10 33 cm -2 sec -1

  8. ring av erfaring?

    DEFF Research Database (Denmark)

    Ramvi, Ellen

    Hva skal til for å lære av erfaring? Denne avhandlingen er en empirisk baseret undersøkelse av ungdosmskolelæreres muligheter og betingelser for å "lære av erfaring" i den særlige betydning av begrepet  W. Bion gir i sin psykoanalytiske teori. Undersøgelsen baserer seg på et feltarbeid som strekker...... seg over ett skoleår. Datamaterialet ble samlet inn via observerasjoner og mer eller mindre strukturerte samtaler med lærere ved to forskellige norske ungdsomsskoler. Analysen av materialet foregår i to trinn: først en fenomenologisk analyse, tett på lærernes egne beskrivelser og refleksjoner av...... lærerarbeidet, dets udfordringer og vanskeligheter, og deretter en psykoanalytisk perspektivering av de fenomenologiske analyseresultatene. Analysen viser en almindelig lærerhverdag og en skoleorganisation, hvor lærernes "læring av erfaring" i stor utstrekning blokkeres i et vekselspill mellem lærernes flukt...

  9. Application of annual ring analyses to the detection of smoke damage. I. A methodical contribution to the treatment of annual ring analyses

    Energy Technology Data Exchange (ETDEWEB)

    Vins, B

    1961-01-01

    Losses in growth of silvicultural stands caused by smoke can be measured by annual ring analysis. The method is advantageous mainly because the annual gains can be checked far into the past and thus compared with gains before the onset of the pollution. Experience gained in the Krusne Hory area of Czechoslovakia with the methodical processing of 2000 annual ring analyses is reviewed. The principal problem was that more than half the trees exposed to pollution failed to grow annual rings. At first no rings are added from the ground up to a certain height; then the defect spreads all the way into the crowns of the affected trees. This observation is of fundamental importance in the calculation of losses in growth gains due to industrial emissions because hitherto the last annual ring next to the bark was always identified with the test year, while in reality a number of annual rings might already have failed to grow due to the effects of pollution. Errors far exceeding permissible limits might have occurred in the analysis.

  10. Nilradicals of skew Hurwitz series of rings

    Directory of Open Access Journals (Sweden)

    Morteza Ahmadi

    2015-05-01

    Full Text Available ‎For a ring endomorphism α of a ring R, ‎Krempa called α a rigid endomorphism if aα(a=0 implies a = 0 for a in R. ‎A ring R is called rigid if there exists a rigid endomorphism of R. ‎In this paper‎, ‎we extend the α-rigid property of a ring R to the upper nilradical N_r(R of R. ‎For an endomorphism α and the upper nilradical N_r(R of a ring R, ‎we introduce the condition (*: ‎N_r(R is a α-ideal of R and aα(a in N_r(R implies a in N_r(R for a in R. ‎We study characterizations of a ring R with an endomorphism α satisfying the condition (*, ‎and we investigate their related properties‎. ‎The connections between the upper nilradical of R and the upper nilradical of the skew Hurwitz series ring (HR,α of R are also investigated‎.

  11. Common pass decentered annular ring resonator

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, D. A.; Waite, T. R.

    1985-04-30

    An optical resonator having an annular cylindrical gain region for use in a chemical laser or the like in which two ring-shaped mirrors having substantially conical reflecting surfaces are spaced apart along a common axis of revolution of the respective conical surfaces. A central conical mirror reflects incident light directed along said axis radially outwardly to the reflecting surface of a first one of the ring-shaped mirrors. The radial light rays are reflected by the first ring mirror to the second ring mirror within an annular cylindrical volume concentric with said common axis and forming a gain region. Light rays impinging on the second ring mirror are reflected to diametrically opposite points on the same conical mirror surfaces and back to the first ring mirror through the same annular cylindrical volume. The return rays are then reflected by the conical mirror surface of the first ring mirror back to the central conical mirror. The mirror surfaces are angled such that the return rays are reflected back along the common axis by the central mirror in a concentric annular cylindrical volume. A scraper mirror having a central opening centered on said axis and an offset opening reflects all but the rays passing through the two openings in an output beam. The rays passing through the second opening are reflected back through the first opening to provide feedback.

  12. Vortex Ring Interaction with a Heated Screen

    Science.gov (United States)

    Smith, Jason; Krueger, Paul S.

    2008-11-01

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

  13. Tritium concentrations in tree ring cellulose

    International Nuclear Information System (INIS)

    Kaji, Toshio; Momoshima, Noriyuki; Takashima, Yoshimasa.

    1989-01-01

    Measurements of tritium (tissue bound tritium; TBT) concentration in tree rings are presented and discussed. Such measurement is expected to provide a useful means of estimating the tritium level in the environment in the past. The concentration of tritium bound in the tissue (TBT) in a tree ring considered to reflect the environmental tritium level in the area at the time of the formation of the ring, while the concentration of tritium in the free water in the tissue represents the current environmental tritium level. First, tritium concentration in tree ring cellulose sampled from a cedar tree grown in a typical environment in Fukuoka Prefecture is compared with the tritium concentration in precipitation in Tokyo. Results show that the year-to-year variations in the tritium concentration in the tree rings agree well with those in precipitation. The maximum concentration, which occurred in 1963, is attibuted to atmospheric nuclear testing which was performed frequently during the 1961 - 1963 period. Measurement is also made of the tritium concentration in tree ring cellulose sampled from a pine tree grown near the Isotope Center of Kyushu University (Fukuoka). Results indicate that the background level is higher probably due to the release of tritium from the facilities around the pine tree. Thus, measurement of tritium in tree ring cellulose clearly shows the year-to-year variation in the tritium concentration in the atmosphere. (N.K.)

  14. Vortex Ring Dynamics in Radially Confined Domains

    Science.gov (United States)

    Stewart, Kelley; Niebel, Casandra; Jung, Sunghwan; Vlachos, Pavlos

    2010-11-01

    Vortex ring dynamics have been studied extensively in semi-infinite quiescent volumes. However, very little is known about vortex-ring formation in wall-bounded domains where vortex wall interaction will affect both the vortex ring pinch-off and propagation velocity. This study addresses this limitation and studies vortex formation in radially confined domains to analyze the affect of vortex-ring wall interaction on the formation and propagation of the vortex ring. Vortex rings were produced using a pneumatically driven piston cylinder arrangement and were ejected into a long cylindrical tube which defined the confined downstream domain. A range of confinement domains were studied with varying confinement diameters Velocity field measurements were performed using planar Time Resolved Digital Particle Image Velocimetry (TRDPIV) and were processed using an in-house developed cross-correlation PIV algorithm. The experimental analysis was used to facilitate the development of a theoretical model to predict the variations in vortex ring circulation over time within confined domains.

  15. Design and jump phenomenon analysis of an eccentric ring energy harvester

    International Nuclear Information System (INIS)

    Wang, Yu-Jen; Chen, Chung-De

    2013-01-01

    This paper presents the development of a wheel-mounted eccentric ring energy harvester that is driven by centripetal and gravitational forces during wheel rotation. The natural frequency of the eccentric ring matches the wheel rotation frequency at any car speed because its character length is designed equal to the wheel radius. Consequently, the eccentric ring oscillates with a relatively large swing angle at the wheel speed to generate high levels of power. The nonlinear dynamic behavior of the eccentric ring is investigated to ensure that the proposed design produces steady swing angles, especially at high wheel speeds. Herein, the jump phenomenon of the dynamic motion of the eccentric ring is analyzed by using the Duffing equation and the linearization process. The discriminant value obtained from the analysis confirms that no jump phenomenon occurs at all wheel speeds if the eccentric ring is properly designed. In the experiment, the eccentric ring is integrated with magnets and a coil set to generate 318–442 μW at constant wheel speeds between 300 and 500 rpm. This shows that the proposed device is a potential power source for low-power wheel-mounted electronics, such as pressure sensors, accelerometers, and thermometers. (paper)

  16. Design and jump phenomenon analysis of an eccentric ring energy harvester

    Science.gov (United States)

    Wang, Yu-Jen; Chen, Chung-De

    2013-10-01

    This paper presents the development of a wheel-mounted eccentric ring energy harvester that is driven by centripetal and gravitational forces during wheel rotation. The natural frequency of the eccentric ring matches the wheel rotation frequency at any car speed because its character length is designed equal to the wheel radius. Consequently, the eccentric ring oscillates with a relatively large swing angle at the wheel speed to generate high levels of power. The nonlinear dynamic behavior of the eccentric ring is investigated to ensure that the proposed design produces steady swing angles, especially at high wheel speeds. Herein, the jump phenomenon of the dynamic motion of the eccentric ring is analyzed by using the Duffing equation and the linearization process. The discriminant value obtained from the analysis confirms that no jump phenomenon occurs at all wheel speeds if the eccentric ring is properly designed. In the experiment, the eccentric ring is integrated with magnets and a coil set to generate 318-442 μW at constant wheel speeds between 300 and 500 rpm. This shows that the proposed device is a potential power source for low-power wheel-mounted electronics, such as pressure sensors, accelerometers, and thermometers.

  17. Development of stress relaxation measurement by a small size C-ring specimen method

    International Nuclear Information System (INIS)

    Shimanuki, Shizuka; Nakata, Kiyotomo; Kasahara, Shigeki; Kuniya, Jiro

    2002-01-01

    A stress relaxation measurement method has been developed by using C-ring specimens, and a specimen size effect has been evaluated taking radiation-induced stress relaxation into consideration. C-ring specimens were stressed by forcing a wedge in the gap. Giving an appropriate eccentric configuration in the half of the ring opposite the gap, the stress gradient along the circumference was eliminated in the section and the stress level could be varied by changing the gap spacing. The validity of the C-ring test method was confirmed by thermally stress relaxation experiments at annealing temperatures from 300 to 600degC for 1 min to 200 h in carbon steel: considerable stress relaxation could be measured for all levels of applied stress even at relatively low annealing temperatures. The relaxation results obtained from the C-ring test were in good agreement with those from a uniaxial tensile stress relaxation test. The smaller C-ring specimen with about 40 mm diameter, which is required for radiation-induced stress relaxation test, also showed adequate accuracy on stress relaxation at 600 to 830degC in stainless steel, compared with the large size C-ring specimen test. (author)

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

    Science.gov (United States)

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

    2018-04-25

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

  19. Beam dynamics in Compton ring gamma sources

    Directory of Open Access Journals (Sweden)

    Eugene Bulyak

    2006-09-01

    Full Text Available Electron storage rings of GeV energy with laser pulse stacking cavities are promising intense sources of polarized hard photons which, via pair production, can be used to generate polarized positron beams. In this paper, the dynamics of electron bunches circulating in a storage ring and interacting with high-power laser pulses is studied both analytically and by simulation. Both the common features and the differences in the behavior of bunches interacting with an extremely high power laser pulse and with a moderate pulse are discussed. Also considerations on particular lattice designs for Compton gamma rings are presented.

  20. Lifetime measurement of ATF damping ring

    International Nuclear Information System (INIS)

    Okugi, T.; Hayano, H.; Kubo, K.; Naito, T.; Terunuma, N.; Urakawa, J.; Zimmermann, F.

    1998-06-01

    The purpose of the ATF damping ring is the development of technologies for producing a low emittance beam required in future linear colliders such as JLC. The lifetime of the damping ring is very short (typically a few minutes). It is limited by elastic beam-gas scattering along with a small dynamic aperture, and by single intra-beam scattering (Touschek effect). The Touschek lifetime strongly depends upon the charge density of the beam, especially, the size of the vertical emittance. In this paper, the authors report the results of beam lifetime measurements in the ATF damping ring and the estimation of the vertical emittance from these measurements